Initial import of modified Linux 2.6.28 tree

Original upstream URL:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git | branch linux-2.6.28.y

125 files changed, 78235 insertions, 0 deletions

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
new file mode 100644
index 0000000..691268f
--- /dev/null
+++ b/net/ipv4/Kconfig
@@ -0,0 +1,632 @@
+#
+# IP configuration
+#
+config IP_MULTICAST
+	bool "IP: multicasting"
+	help
+	  This is code for addressing several networked computers at once,
+	  enlarging your kernel by about 2 KB. You need multicasting if you
+	  intend to participate in the MBONE, a high bandwidth network on top
+	  of the Internet which carries audio and video broadcasts. More
+	  information about the MBONE is on the WWW at
+	  <http://www.savetz.com/mbone/>. Information about the multicast
+	  capabilities of the various network cards is contained in
+	  <file:Documentation/networking/multicast.txt>. For most people, it's
+	  safe to say N.
+
+config IP_ADVANCED_ROUTER
+	bool "IP: advanced router"
+	---help---
+	  If you intend to run your Linux box mostly as a router, i.e. as a
+	  computer that forwards and redistributes network packets, say Y; you
+	  will then be presented with several options that allow more precise
+	  control about the routing process.
+
+	  The answer to this question won't directly affect the kernel:
+	  answering N will just cause the configurator to skip all the
+	  questions about advanced routing.
+
+	  Note that your box can only act as a router if you enable IP
+	  forwarding in your kernel; you can do that by saying Y to "/proc
+	  file system support" and "Sysctl support" below and executing the
+	  line
+
+	  echo "1" > /proc/sys/net/ipv4/ip_forward
+
+	  at boot time after the /proc file system has been mounted.
+
+	  If you turn on IP forwarding, you will also get the rp_filter, which
+	  automatically rejects incoming packets if the routing table entry
+	  for their source address doesn't match the network interface they're
+	  arriving on. This has security advantages because it prevents the
+	  so-called IP spoofing, however it can pose problems if you use
+	  asymmetric routing (packets from you to a host take a different path
+	  than packets from that host to you) or if you operate a non-routing
+	  host which has several IP addresses on different interfaces. To turn
+	  rp_filter on use:
+
+	  echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
+	  or
+	  echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
+
+	  If unsure, say N here.
+
+choice 
+	prompt "Choose IP: FIB lookup algorithm (choose FIB_HASH if unsure)"
+	depends on IP_ADVANCED_ROUTER
+	default ASK_IP_FIB_HASH
+
+config ASK_IP_FIB_HASH
+	bool "FIB_HASH"
+	---help---
+	Current FIB is very proven and good enough for most users.
+
+config IP_FIB_TRIE
+	bool "FIB_TRIE"
+	---help---
+	Use new experimental LC-trie as FIB lookup algorithm. 
+        This improves lookup performance if you have a large
+	number of routes.
+
+	LC-trie is a longest matching prefix lookup algorithm which
+	performs better than FIB_HASH for large routing tables.
+	But, it consumes more memory and is more complex.
+	
+	LC-trie is described in:
+	
+ 	IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ 	IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+	An experimental study of compression methods for dynamic tries
+ 	Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
+ 	http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
+       
+endchoice
+
+config IP_FIB_HASH
+	def_bool ASK_IP_FIB_HASH || !IP_ADVANCED_ROUTER
+
+config IP_FIB_TRIE_STATS
+	bool "FIB TRIE statistics"
+	depends on IP_FIB_TRIE
+	---help---
+	  Keep track of statistics on structure of FIB TRIE table.
+	  Useful for testing and measuring TRIE performance.
+
+config IP_MULTIPLE_TABLES
+	bool "IP: policy routing"
+	depends on IP_ADVANCED_ROUTER
+	select FIB_RULES
+	---help---
+	  Normally, a router decides what to do with a received packet based
+	  solely on the packet's final destination address. If you say Y here,
+	  the Linux router will also be able to take the packet's source
+	  address into account. Furthermore, the TOS (Type-Of-Service) field
+	  of the packet can be used for routing decisions as well.
+
+	  If you are interested in this, please see the preliminary
+	  documentation at <http://www.compendium.com.ar/policy-routing.txt>
+	  and <ftp://post.tepkom.ru/pub/vol2/Linux/docs/advanced-routing.tex>.
+	  You will need supporting software from
+	  <ftp://ftp.tux.org/pub/net/ip-routing/>.
+
+	  If unsure, say N.
+
+config IP_ROUTE_MULTIPATH
+	bool "IP: equal cost multipath"
+	depends on IP_ADVANCED_ROUTER
+	help
+	  Normally, the routing tables specify a single action to be taken in
+	  a deterministic manner for a given packet. If you say Y here
+	  however, it becomes possible to attach several actions to a packet
+	  pattern, in effect specifying several alternative paths to travel
+	  for those packets. The router considers all these paths to be of
+	  equal "cost" and chooses one of them in a non-deterministic fashion
+	  if a matching packet arrives.
+
+config IP_ROUTE_VERBOSE
+	bool "IP: verbose route monitoring"
+	depends on IP_ADVANCED_ROUTER
+	help
+	  If you say Y here, which is recommended, then the kernel will print
+	  verbose messages regarding the routing, for example warnings about
+	  received packets which look strange and could be evidence of an
+	  attack or a misconfigured system somewhere. The information is
+	  handled by the klogd daemon which is responsible for kernel messages
+	  ("man klogd").
+
+config IP_PNP
+	bool "IP: kernel level autoconfiguration"
+	help
+	  This enables automatic configuration of IP addresses of devices and
+	  of the routing table during kernel boot, based on either information
+	  supplied on the kernel command line or by BOOTP or RARP protocols.
+	  You need to say Y only for diskless machines requiring network
+	  access to boot (in which case you want to say Y to "Root file system
+	  on NFS" as well), because all other machines configure the network
+	  in their startup scripts.
+
+config IP_PNP_DHCP
+	bool "IP: DHCP support"
+	depends on IP_PNP
+	---help---
+	  If you want your Linux box to mount its whole root file system (the
+	  one containing the directory /) from some other computer over the
+	  net via NFS and you want the IP address of your computer to be
+	  discovered automatically at boot time using the DHCP protocol (a
+	  special protocol designed for doing this job), say Y here. In case
+	  the boot ROM of your network card was designed for booting Linux and
+	  does DHCP itself, providing all necessary information on the kernel
+	  command line, you can say N here.
+
+	  If unsure, say Y. Note that if you want to use DHCP, a DHCP server
+	  must be operating on your network.  Read
+	  <file:Documentation/filesystems/nfsroot.txt> for details.
+
+config IP_PNP_BOOTP
+	bool "IP: BOOTP support"
+	depends on IP_PNP
+	---help---
+	  If you want your Linux box to mount its whole root file system (the
+	  one containing the directory /) from some other computer over the
+	  net via NFS and you want the IP address of your computer to be
+	  discovered automatically at boot time using the BOOTP protocol (a
+	  special protocol designed for doing this job), say Y here. In case
+	  the boot ROM of your network card was designed for booting Linux and
+	  does BOOTP itself, providing all necessary information on the kernel
+	  command line, you can say N here. If unsure, say Y. Note that if you
+	  want to use BOOTP, a BOOTP server must be operating on your network.
+	  Read <file:Documentation/filesystems/nfsroot.txt> for details.
+
+config IP_PNP_RARP
+	bool "IP: RARP support"
+	depends on IP_PNP
+	help
+	  If you want your Linux box to mount its whole root file system (the
+	  one containing the directory /) from some other computer over the
+	  net via NFS and you want the IP address of your computer to be
+	  discovered automatically at boot time using the RARP protocol (an
+	  older protocol which is being obsoleted by BOOTP and DHCP), say Y
+	  here. Note that if you want to use RARP, a RARP server must be
+	  operating on your network. Read
+	  <file:Documentation/filesystems/nfsroot.txt> for details.
+
+# not yet ready..
+#   bool '    IP: ARP support' CONFIG_IP_PNP_ARP		
+config NET_IPIP
+	tristate "IP: tunneling"
+	select INET_TUNNEL
+	---help---
+	  Tunneling means encapsulating data of one protocol type within
+	  another protocol and sending it over a channel that understands the
+	  encapsulating protocol. This particular tunneling driver implements
+	  encapsulation of IP within IP, which sounds kind of pointless, but
+	  can be useful if you want to make your (or some other) machine
+	  appear on a different network than it physically is, or to use
+	  mobile-IP facilities (allowing laptops to seamlessly move between
+	  networks without changing their IP addresses).
+
+	  Saying Y to this option will produce two modules ( = code which can
+	  be inserted in and removed from the running kernel whenever you
+	  want). Most people won't need this and can say N.
+
+config NET_IPGRE
+	tristate "IP: GRE tunnels over IP"
+	help
+	  Tunneling means encapsulating data of one protocol type within
+	  another protocol and sending it over a channel that understands the
+	  encapsulating protocol. This particular tunneling driver implements
+	  GRE (Generic Routing Encapsulation) and at this time allows
+	  encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
+	  This driver is useful if the other endpoint is a Cisco router: Cisco
+	  likes GRE much better than the other Linux tunneling driver ("IP
+	  tunneling" above). In addition, GRE allows multicast redistribution
+	  through the tunnel.
+
+config NET_IPGRE_BROADCAST
+	bool "IP: broadcast GRE over IP"
+	depends on IP_MULTICAST && NET_IPGRE
+	help
+	  One application of GRE/IP is to construct a broadcast WAN (Wide Area
+	  Network), which looks like a normal Ethernet LAN (Local Area
+	  Network), but can be distributed all over the Internet. If you want
+	  to do that, say Y here and to "IP multicast routing" below.
+
+config IP_MROUTE
+	bool "IP: multicast routing"
+	depends on IP_MULTICAST
+	help
+	  This is used if you want your machine to act as a router for IP
+	  packets that have several destination addresses. It is needed on the
+	  MBONE, a high bandwidth network on top of the Internet which carries
+	  audio and video broadcasts. In order to do that, you would most
+	  likely run the program mrouted. Information about the multicast
+	  capabilities of the various network cards is contained in
+	  <file:Documentation/networking/multicast.txt>. If you haven't heard
+	  about it, you don't need it.
+
+config IP_PIMSM_V1
+	bool "IP: PIM-SM version 1 support"
+	depends on IP_MROUTE
+	help
+	  Kernel side support for Sparse Mode PIM (Protocol Independent
+	  Multicast) version 1. This multicast routing protocol is used widely
+	  because Cisco supports it. You need special software to use it
+	  (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
+	  information about PIM.
+
+	  Say Y if you want to use PIM-SM v1. Note that you can say N here if
+	  you just want to use Dense Mode PIM.
+
+config IP_PIMSM_V2
+	bool "IP: PIM-SM version 2 support"
+	depends on IP_MROUTE
+	help
+	  Kernel side support for Sparse Mode PIM version 2. In order to use
+	  this, you need an experimental routing daemon supporting it (pimd or
+	  gated-5). This routing protocol is not used widely, so say N unless
+	  you want to play with it.
+
+config ARPD
+	bool "IP: ARP daemon support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	---help---
+	  Normally, the kernel maintains an internal cache which maps IP
+	  addresses to hardware addresses on the local network, so that
+	  Ethernet/Token Ring/ etc. frames are sent to the proper address on
+	  the physical networking layer. For small networks having a few
+	  hundred directly connected hosts or less, keeping this address
+	  resolution (ARP) cache inside the kernel works well. However,
+	  maintaining an internal ARP cache does not work well for very large
+	  switched networks, and will use a lot of kernel memory if TCP/IP
+	  connections are made to many machines on the network.
+
+	  If you say Y here, the kernel's internal ARP cache will never grow
+	  to more than 256 entries (the oldest entries are expired in a LIFO
+	  manner) and communication will be attempted with the user space ARP
+	  daemon arpd. Arpd then answers the address resolution request either
+	  from its own cache or by asking the net.
+
+	  This code is experimental and also obsolete. If you want to use it,
+	  you need to find a version of the daemon arpd on the net somewhere,
+	  and you should also say Y to "Kernel/User network link driver",
+	  below. If unsure, say N.
+
+config SYN_COOKIES
+	bool "IP: TCP syncookie support (disabled per default)"
+	---help---
+	  Normal TCP/IP networking is open to an attack known as "SYN
+	  flooding". This denial-of-service attack prevents legitimate remote
+	  users from being able to connect to your computer during an ongoing
+	  attack and requires very little work from the attacker, who can
+	  operate from anywhere on the Internet.
+
+	  SYN cookies provide protection against this type of attack. If you
+	  say Y here, the TCP/IP stack will use a cryptographic challenge
+	  protocol known as "SYN cookies" to enable legitimate users to
+	  continue to connect, even when your machine is under attack. There
+	  is no need for the legitimate users to change their TCP/IP software;
+	  SYN cookies work transparently to them. For technical information
+	  about SYN cookies, check out <http://cr.yp.to/syncookies.html>.
+
+	  If you are SYN flooded, the source address reported by the kernel is
+	  likely to have been forged by the attacker; it is only reported as
+	  an aid in tracing the packets to their actual source and should not
+	  be taken as absolute truth.
+
+	  SYN cookies may prevent correct error reporting on clients when the
+	  server is really overloaded. If this happens frequently better turn
+	  them off.
+
+	  If you say Y here, note that SYN cookies aren't enabled by default;
+	  you can enable them by saying Y to "/proc file system support" and
+	  "Sysctl support" below and executing the command
+
+	  echo 1 >/proc/sys/net/ipv4/tcp_syncookies
+
+	  at boot time after the /proc file system has been mounted.
+
+	  If unsure, say N.
+
+config INET_AH
+	tristate "IP: AH transformation"
+	select XFRM
+	select CRYPTO
+	select CRYPTO_HMAC
+	select CRYPTO_MD5
+	select CRYPTO_SHA1
+	---help---
+	  Support for IPsec AH.
+
+	  If unsure, say Y.
+
+config INET_ESP
+	tristate "IP: ESP transformation"
+	select XFRM
+	select CRYPTO
+	select CRYPTO_AUTHENC
+	select CRYPTO_HMAC
+	select CRYPTO_MD5
+	select CRYPTO_CBC
+	select CRYPTO_SHA1
+	select CRYPTO_DES
+	---help---
+	  Support for IPsec ESP.
+
+	  If unsure, say Y.
+
+config INET_IPCOMP
+	tristate "IP: IPComp transformation"
+	select INET_XFRM_TUNNEL
+	select XFRM_IPCOMP
+	---help---
+	  Support for IP Payload Compression Protocol (IPComp) (RFC3173),
+	  typically needed for IPsec.
+	  
+	  If unsure, say Y.
+
+config INET_XFRM_TUNNEL
+	tristate
+	select INET_TUNNEL
+	default n
+
+config INET_TUNNEL
+	tristate
+	default n
+
+config INET_XFRM_MODE_TRANSPORT
+	tristate "IP: IPsec transport mode"
+	default y
+	select XFRM
+	---help---
+	  Support for IPsec transport mode.
+
+	  If unsure, say Y.
+
+config INET_XFRM_MODE_TUNNEL
+	tristate "IP: IPsec tunnel mode"
+	default y
+	select XFRM
+	---help---
+	  Support for IPsec tunnel mode.
+
+	  If unsure, say Y.
+
+config INET_XFRM_MODE_BEET
+	tristate "IP: IPsec BEET mode"
+	default y
+	select XFRM
+	---help---
+	  Support for IPsec BEET mode.
+
+	  If unsure, say Y.
+
+config INET_LRO
+	tristate "Large Receive Offload (ipv4/tcp)"
+
+	---help---
+	  Support for Large Receive Offload (ipv4/tcp).
+
+	  If unsure, say Y.
+
+config INET_DIAG
+	tristate "INET: socket monitoring interface"
+	default y
+	---help---
+	  Support for INET (TCP, DCCP, etc) socket monitoring interface used by
+	  native Linux tools such as ss. ss is included in iproute2, currently
+	  downloadable at <http://linux-net.osdl.org/index.php/Iproute2>.
+	  
+	  If unsure, say Y.
+
+config INET_TCP_DIAG
+	depends on INET_DIAG
+	def_tristate INET_DIAG
+
+menuconfig TCP_CONG_ADVANCED
+	bool "TCP: advanced congestion control"
+	---help---
+	  Support for selection of various TCP congestion control
+	  modules.
+
+	  Nearly all users can safely say no here, and a safe default
+	  selection will be made (CUBIC with new Reno as a fallback).
+
+	  If unsure, say N.
+
+if TCP_CONG_ADVANCED
+
+config TCP_CONG_BIC
+	tristate "Binary Increase Congestion (BIC) control"
+	default m
+	---help---
+	BIC-TCP is a sender-side only change that ensures a linear RTT
+	fairness under large windows while offering both scalability and
+	bounded TCP-friendliness. The protocol combines two schemes
+	called additive increase and binary search increase. When the
+	congestion window is large, additive increase with a large
+	increment ensures linear RTT fairness as well as good
+	scalability. Under small congestion windows, binary search
+	increase provides TCP friendliness.
+	See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
+
+config TCP_CONG_CUBIC
+	tristate "CUBIC TCP"
+	default y
+	---help---
+	This is version 2.0 of BIC-TCP which uses a cubic growth function
+	among other techniques.
+	See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
+
+config TCP_CONG_WESTWOOD
+	tristate "TCP Westwood+"
+	default m
+	---help---
+	TCP Westwood+ is a sender-side only modification of the TCP Reno
+	protocol stack that optimizes the performance of TCP congestion
+	control. It is based on end-to-end bandwidth estimation to set
+	congestion window and slow start threshold after a congestion
+	episode. Using this estimation, TCP Westwood+ adaptively sets a
+	slow start threshold and a congestion window which takes into
+	account the bandwidth used  at the time congestion is experienced.
+	TCP Westwood+ significantly increases fairness wrt TCP Reno in
+	wired networks and throughput over wireless links.
+
+config TCP_CONG_HTCP
+        tristate "H-TCP"
+        default m
+	---help---
+	H-TCP is a send-side only modifications of the TCP Reno
+	protocol stack that optimizes the performance of TCP
+	congestion control for high speed network links. It uses a
+	modeswitch to change the alpha and beta parameters of TCP Reno
+	based on network conditions and in a way so as to be fair with
+	other Reno and H-TCP flows.
+
+config TCP_CONG_HSTCP
+	tristate "High Speed TCP"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	Sally Floyd's High Speed TCP (RFC 3649) congestion control.
+	A modification to TCP's congestion control mechanism for use
+	with large congestion windows. A table indicates how much to
+	increase the congestion window by when an ACK is received.
+ 	For more detail	see http://www.icir.org/floyd/hstcp.html
+
+config TCP_CONG_HYBLA
+	tristate "TCP-Hybla congestion control algorithm"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	TCP-Hybla is a sender-side only change that eliminates penalization of
+	long-RTT, large-bandwidth connections, like when satellite legs are
+	involved, especially when sharing a common bottleneck with normal
+	terrestrial connections.
+
+config TCP_CONG_VEGAS
+	tristate "TCP Vegas"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	TCP Vegas is a sender-side only change to TCP that anticipates
+	the onset of congestion by estimating the bandwidth. TCP Vegas
+	adjusts the sending rate by modifying the congestion
+	window. TCP Vegas should provide less packet loss, but it is
+	not as aggressive as TCP Reno.
+
+config TCP_CONG_SCALABLE
+	tristate "Scalable TCP"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	Scalable TCP is a sender-side only change to TCP which uses a
+	MIMD congestion control algorithm which has some nice scaling
+	properties, though is known to have fairness issues.
+	See http://www.deneholme.net/tom/scalable/
+
+config TCP_CONG_LP
+	tristate "TCP Low Priority"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
+	to utilize only the excess network bandwidth as compared to the
+	``fair share`` of bandwidth as targeted by TCP.
+	See http://www-ece.rice.edu/networks/TCP-LP/
+
+config TCP_CONG_VENO
+	tristate "TCP Veno"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	TCP Veno is a sender-side only enhancement of TCP to obtain better
+	throughput over wireless networks. TCP Veno makes use of state
+	distinguishing to circumvent the difficult judgment of the packet loss
+	type. TCP Veno cuts down less congestion window in response to random
+	loss packets.
+	See http://www.ntu.edu.sg/home5/ZHOU0022/papers/CPFu03a.pdf
+
+config TCP_CONG_YEAH
+	tristate "YeAH TCP"
+	depends on EXPERIMENTAL
+	select TCP_CONG_VEGAS
+	default n
+	---help---
+	YeAH-TCP is a sender-side high-speed enabled TCP congestion control
+	algorithm, which uses a mixed loss/delay approach to compute the
+	congestion window. It's design goals target high efficiency,
+	internal, RTT and Reno fairness, resilience to link loss while
+	keeping network elements load as low as possible.
+
+	For further details look here:
+	  http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
+
+config TCP_CONG_ILLINOIS
+	tristate "TCP Illinois"
+	depends on EXPERIMENTAL
+	default n
+	---help---
+	TCP-Illinois is a sender-side modification of TCP Reno for
+	high speed long delay links. It uses round-trip-time to
+	adjust the alpha and beta parameters to achieve a higher average
+	throughput and maintain fairness.
+
+	For further details see:
+	  http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
+
+choice
+	prompt "Default TCP congestion control"
+	default DEFAULT_CUBIC
+	help
+	  Select the TCP congestion control that will be used by default
+	  for all connections.
+
+	config DEFAULT_BIC
+		bool "Bic" if TCP_CONG_BIC=y
+
+	config DEFAULT_CUBIC
+		bool "Cubic" if TCP_CONG_CUBIC=y
+
+	config DEFAULT_HTCP
+		bool "Htcp" if TCP_CONG_HTCP=y
+
+	config DEFAULT_VEGAS
+		bool "Vegas" if TCP_CONG_VEGAS=y
+
+	config DEFAULT_WESTWOOD
+		bool "Westwood" if TCP_CONG_WESTWOOD=y
+
+	config DEFAULT_RENO
+		bool "Reno"
+
+endchoice
+
+endif
+
+config TCP_CONG_CUBIC
+	tristate
+	depends on !TCP_CONG_ADVANCED
+	default y
+
+config DEFAULT_TCP_CONG
+	string
+	default "bic" if DEFAULT_BIC
+	default "cubic" if DEFAULT_CUBIC
+	default "htcp" if DEFAULT_HTCP
+	default "vegas" if DEFAULT_VEGAS
+	default "westwood" if DEFAULT_WESTWOOD
+	default "reno" if DEFAULT_RENO
+	default "cubic"
+
+config TCP_MD5SIG
+	bool "TCP: MD5 Signature Option support (RFC2385) (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	select CRYPTO
+	select CRYPTO_MD5
+	---help---
+	  RFC2385 specifies a method of giving MD5 protection to TCP sessions.
+	  Its main (only?) use is to protect BGP sessions between core routers
+	  on the Internet.
+
+	  If unsure, say N.
+
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
new file mode 100644
index 0000000..80ff87c
--- /dev/null
+++ b/net/ipv4/Makefile
@@ -0,0 +1,54 @@
+#
+# Makefile for the Linux TCP/IP (INET) layer.
+#
+
+obj-y     := route.o inetpeer.o protocol.o \
+	     ip_input.o ip_fragment.o ip_forward.o ip_options.o \
+	     ip_output.o ip_sockglue.o inet_hashtables.o \
+	     inet_timewait_sock.o inet_connection_sock.o \
+	     tcp.o tcp_input.o tcp_output.o tcp_timer.o tcp_ipv4.o \
+	     tcp_minisocks.o tcp_cong.o \
+	     datagram.o raw.o udp.o udplite.o \
+	     arp.o icmp.o devinet.o af_inet.o  igmp.o \
+	     fib_frontend.o fib_semantics.o \
+	     inet_fragment.o
+
+obj-$(CONFIG_SYSCTL) += sysctl_net_ipv4.o
+obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o
+obj-$(CONFIG_IP_FIB_TRIE) += fib_trie.o
+obj-$(CONFIG_PROC_FS) += proc.o
+obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
+obj-$(CONFIG_IP_MROUTE) += ipmr.o
+obj-$(CONFIG_NET_IPIP) += ipip.o
+obj-$(CONFIG_NET_IPGRE) += ip_gre.o
+obj-$(CONFIG_SYN_COOKIES) += syncookies.o
+obj-$(CONFIG_INET_AH) += ah4.o
+obj-$(CONFIG_INET_ESP) += esp4.o
+obj-$(CONFIG_INET_IPCOMP) += ipcomp.o
+obj-$(CONFIG_INET_XFRM_TUNNEL) += xfrm4_tunnel.o
+obj-$(CONFIG_INET_XFRM_MODE_BEET) += xfrm4_mode_beet.o
+obj-$(CONFIG_INET_LRO) += inet_lro.o
+obj-$(CONFIG_INET_TUNNEL) += tunnel4.o
+obj-$(CONFIG_INET_XFRM_MODE_TRANSPORT) += xfrm4_mode_transport.o
+obj-$(CONFIG_INET_XFRM_MODE_TUNNEL) += xfrm4_mode_tunnel.o
+obj-$(CONFIG_IP_PNP) += ipconfig.o
+obj-$(CONFIG_NETFILTER)	+= netfilter.o netfilter/
+obj-$(CONFIG_INET_DIAG) += inet_diag.o 
+obj-$(CONFIG_INET_TCP_DIAG) += tcp_diag.o
+obj-$(CONFIG_NET_TCPPROBE) += tcp_probe.o
+obj-$(CONFIG_TCP_CONG_BIC) += tcp_bic.o
+obj-$(CONFIG_TCP_CONG_CUBIC) += tcp_cubic.o
+obj-$(CONFIG_TCP_CONG_WESTWOOD) += tcp_westwood.o
+obj-$(CONFIG_TCP_CONG_HSTCP) += tcp_highspeed.o
+obj-$(CONFIG_TCP_CONG_HYBLA) += tcp_hybla.o
+obj-$(CONFIG_TCP_CONG_HTCP) += tcp_htcp.o
+obj-$(CONFIG_TCP_CONG_VEGAS) += tcp_vegas.o
+obj-$(CONFIG_TCP_CONG_VENO) += tcp_veno.o
+obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
+obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
+obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
+obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
+obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
+
+obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
+		      xfrm4_output.o
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
new file mode 100644
index 0000000..1aa2dc9
--- /dev/null
+++ b/net/ipv4/af_inet.c
@@ -0,0 +1,1583 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		PF_INET protocol family socket handler.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Alan Cox, <A.Cox@swansea.ac.uk>
+ *
+ * Changes (see also sock.c)
+ *
+ *		piggy,
+ *		Karl Knutson	:	Socket protocol table
+ *		A.N.Kuznetsov	:	Socket death error in accept().
+ *		John Richardson :	Fix non blocking error in connect()
+ *					so sockets that fail to connect
+ *					don't return -EINPROGRESS.
+ *		Alan Cox	:	Asynchronous I/O support
+ *		Alan Cox	:	Keep correct socket pointer on sock
+ *					structures
+ *					when accept() ed
+ *		Alan Cox	:	Semantics of SO_LINGER aren't state
+ *					moved to close when you look carefully.
+ *					With this fixed and the accept bug fixed
+ *					some RPC stuff seems happier.
+ *		Niibe Yutaka	:	4.4BSD style write async I/O
+ *		Alan Cox,
+ *		Tony Gale 	:	Fixed reuse semantics.
+ *		Alan Cox	:	bind() shouldn't abort existing but dead
+ *					sockets. Stops FTP netin:.. I hope.
+ *		Alan Cox	:	bind() works correctly for RAW sockets.
+ *					Note that FreeBSD at least was broken
+ *					in this respect so be careful with
+ *					compatibility tests...
+ *		Alan Cox	:	routing cache support
+ *		Alan Cox	:	memzero the socket structure for
+ *					compactness.
+ *		Matt Day	:	nonblock connect error handler
+ *		Alan Cox	:	Allow large numbers of pending sockets
+ *					(eg for big web sites), but only if
+ *					specifically application requested.
+ *		Alan Cox	:	New buffering throughout IP. Used
+ *					dumbly.
+ *		Alan Cox	:	New buffering now used smartly.
+ *		Alan Cox	:	BSD rather than common sense
+ *					interpretation of listen.
+ *		Germano Caronni	:	Assorted small races.
+ *		Alan Cox	:	sendmsg/recvmsg basic support.
+ *		Alan Cox	:	Only sendmsg/recvmsg now supported.
+ *		Alan Cox	:	Locked down bind (see security list).
+ *		Alan Cox	:	Loosened bind a little.
+ *		Mike McLagan	:	ADD/DEL DLCI Ioctls
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		David S. Miller	:	New socket lookup architecture.
+ *					Some other random speedups.
+ *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
+ *		Andi Kleen	:	Fix inet_stream_connect TCP race.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/capability.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/random.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#include <linux/inet.h>
+#include <linux/igmp.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/arp.h>
+#include <net/route.h>
+#include <net/ip_fib.h>
+#include <net/inet_connection_sock.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/raw.h>
+#include <net/icmp.h>
+#include <net/ipip.h>
+#include <net/inet_common.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#ifdef CONFIG_IP_MROUTE
+#include <linux/mroute.h>
+#endif
+
+extern void ip_mc_drop_socket(struct sock *sk);
+
+/* The inetsw table contains everything that inet_create needs to
+ * build a new socket.
+ */
+static struct list_head inetsw[SOCK_MAX];
+static DEFINE_SPINLOCK(inetsw_lock);
+
+struct ipv4_config ipv4_config;
+
+EXPORT_SYMBOL(ipv4_config);
+
+/* New destruction routine */
+
+void inet_sock_destruct(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+
+	__skb_queue_purge(&sk->sk_receive_queue);
+	__skb_queue_purge(&sk->sk_error_queue);
+
+	sk_mem_reclaim(sk);
+
+	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
+		printk("Attempt to release TCP socket in state %d %p\n",
+		       sk->sk_state, sk);
+		return;
+	}
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		printk("Attempt to release alive inet socket %p\n", sk);
+		return;
+	}
+
+	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
+	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+	WARN_ON(sk->sk_wmem_queued);
+	WARN_ON(sk->sk_forward_alloc);
+
+	kfree(inet->opt);
+	dst_release(sk->sk_dst_cache);
+	sk_refcnt_debug_dec(sk);
+}
+
+/*
+ *	The routines beyond this point handle the behaviour of an AF_INET
+ *	socket object. Mostly it punts to the subprotocols of IP to do
+ *	the work.
+ */
+
+/*
+ *	Automatically bind an unbound socket.
+ */
+
+static int inet_autobind(struct sock *sk)
+{
+	struct inet_sock *inet;
+	/* We may need to bind the socket. */
+	lock_sock(sk);
+	inet = inet_sk(sk);
+	if (!inet->num) {
+		if (sk->sk_prot->get_port(sk, 0)) {
+			release_sock(sk);
+			return -EAGAIN;
+		}
+		inet->sport = htons(inet->num);
+	}
+	release_sock(sk);
+	return 0;
+}
+
+/*
+ *	Move a socket into listening state.
+ */
+int inet_listen(struct socket *sock, int backlog)
+{
+	struct sock *sk = sock->sk;
+	unsigned char old_state;
+	int err;
+
+	lock_sock(sk);
+
+	err = -EINVAL;
+	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
+		goto out;
+
+	old_state = sk->sk_state;
+	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
+		goto out;
+
+	/* Really, if the socket is already in listen state
+	 * we can only allow the backlog to be adjusted.
+	 */
+	if (old_state != TCP_LISTEN) {
+		err = inet_csk_listen_start(sk, backlog);
+		if (err)
+			goto out;
+	}
+	sk->sk_max_ack_backlog = backlog;
+	err = 0;
+
+out:
+	release_sock(sk);
+	return err;
+}
+
+u32 inet_ehash_secret __read_mostly;
+EXPORT_SYMBOL(inet_ehash_secret);
+
+/*
+ * inet_ehash_secret must be set exactly once
+ * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
+ */
+void build_ehash_secret(void)
+{
+	u32 rnd;
+	do {
+		get_random_bytes(&rnd, sizeof(rnd));
+	} while (rnd == 0);
+	spin_lock_bh(&inetsw_lock);
+	if (!inet_ehash_secret)
+		inet_ehash_secret = rnd;
+	spin_unlock_bh(&inetsw_lock);
+}
+EXPORT_SYMBOL(build_ehash_secret);
+
+static inline int inet_netns_ok(struct net *net, int protocol)
+{
+	int hash;
+	struct net_protocol *ipprot;
+
+	if (net == &init_net)
+		return 1;
+
+	hash = protocol & (MAX_INET_PROTOS - 1);
+	ipprot = rcu_dereference(inet_protos[hash]);
+
+	if (ipprot == NULL)
+		/* raw IP is OK */
+		return 1;
+	return ipprot->netns_ok;
+}
+
+/*
+ *	Create an inet socket.
+ */
+
+static int inet_create(struct net *net, struct socket *sock, int protocol)
+{
+	struct sock *sk;
+	struct inet_protosw *answer;
+	struct inet_sock *inet;
+	struct proto *answer_prot;
+	unsigned char answer_flags;
+	char answer_no_check;
+	int try_loading_module = 0;
+	int err;
+
+	if (sock->type != SOCK_RAW &&
+	    sock->type != SOCK_DGRAM &&
+	    !inet_ehash_secret)
+		build_ehash_secret();
+
+	sock->state = SS_UNCONNECTED;
+
+	/* Look for the requested type/protocol pair. */
+lookup_protocol:
+	err = -ESOCKTNOSUPPORT;
+	rcu_read_lock();
+	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
+
+		err = 0;
+		/* Check the non-wild match. */
+		if (protocol == answer->protocol) {
+			if (protocol != IPPROTO_IP)
+				break;
+		} else {
+			/* Check for the two wild cases. */
+			if (IPPROTO_IP == protocol) {
+				protocol = answer->protocol;
+				break;
+			}
+			if (IPPROTO_IP == answer->protocol)
+				break;
+		}
+		err = -EPROTONOSUPPORT;
+	}
+
+	if (unlikely(err)) {
+		if (try_loading_module < 2) {
+			rcu_read_unlock();
+			/*
+			 * Be more specific, e.g. net-pf-2-proto-132-type-1
+			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
+			 */
+			if (++try_loading_module == 1)
+				request_module("net-pf-%d-proto-%d-type-%d",
+					       PF_INET, protocol, sock->type);
+			/*
+			 * Fall back to generic, e.g. net-pf-2-proto-132
+			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
+			 */
+			else
+				request_module("net-pf-%d-proto-%d",
+					       PF_INET, protocol);
+			goto lookup_protocol;
+		} else
+			goto out_rcu_unlock;
+	}
+
+	err = -EPERM;
+	if (answer->capability > 0 && !capable(answer->capability))
+		goto out_rcu_unlock;
+
+	err = -EAFNOSUPPORT;
+	if (!inet_netns_ok(net, protocol))
+		goto out_rcu_unlock;
+
+	sock->ops = answer->ops;
+	answer_prot = answer->prot;
+	answer_no_check = answer->no_check;
+	answer_flags = answer->flags;
+	rcu_read_unlock();
+
+	WARN_ON(answer_prot->slab == NULL);
+
+	err = -ENOBUFS;
+	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
+	if (sk == NULL)
+		goto out;
+
+	err = 0;
+	sk->sk_no_check = answer_no_check;
+	if (INET_PROTOSW_REUSE & answer_flags)
+		sk->sk_reuse = 1;
+
+	inet = inet_sk(sk);
+	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
+
+	if (SOCK_RAW == sock->type) {
+		inet->num = protocol;
+		if (IPPROTO_RAW == protocol)
+			inet->hdrincl = 1;
+	}
+
+	if (ipv4_config.no_pmtu_disc)
+		inet->pmtudisc = IP_PMTUDISC_DONT;
+	else
+		inet->pmtudisc = IP_PMTUDISC_WANT;
+
+	inet->id = 0;
+
+	sock_init_data(sock, sk);
+
+	sk->sk_destruct	   = inet_sock_destruct;
+	sk->sk_family	   = PF_INET;
+	sk->sk_protocol	   = protocol;
+	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
+
+	inet->uc_ttl	= -1;
+	inet->mc_loop	= 1;
+	inet->mc_ttl	= 1;
+	inet->mc_index	= 0;
+	inet->mc_list	= NULL;
+
+	sk_refcnt_debug_inc(sk);
+
+	if (inet->num) {
+		/* It assumes that any protocol which allows
+		 * the user to assign a number at socket
+		 * creation time automatically
+		 * shares.
+		 */
+		inet->sport = htons(inet->num);
+		/* Add to protocol hash chains. */
+		sk->sk_prot->hash(sk);
+	}
+
+	if (sk->sk_prot->init) {
+		err = sk->sk_prot->init(sk);
+		if (err)
+			sk_common_release(sk);
+	}
+out:
+	return err;
+out_rcu_unlock:
+	rcu_read_unlock();
+	goto out;
+}
+
+
+/*
+ *	The peer socket should always be NULL (or else). When we call this
+ *	function we are destroying the object and from then on nobody
+ *	should refer to it.
+ */
+int inet_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	if (sk) {
+		long timeout;
+
+		/* Applications forget to leave groups before exiting */
+		ip_mc_drop_socket(sk);
+
+		/* If linger is set, we don't return until the close
+		 * is complete.  Otherwise we return immediately. The
+		 * actually closing is done the same either way.
+		 *
+		 * If the close is due to the process exiting, we never
+		 * linger..
+		 */
+		timeout = 0;
+		if (sock_flag(sk, SOCK_LINGER) &&
+		    !(current->flags & PF_EXITING))
+			timeout = sk->sk_lingertime;
+		sock->sk = NULL;
+		sk->sk_prot->close(sk, timeout);
+	}
+	return 0;
+}
+
+/* It is off by default, see below. */
+int sysctl_ip_nonlocal_bind __read_mostly;
+
+int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
+{
+	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
+	struct sock *sk = sock->sk;
+	struct inet_sock *inet = inet_sk(sk);
+	unsigned short snum;
+	int chk_addr_ret;
+	int err;
+
+	/* If the socket has its own bind function then use it. (RAW) */
+	if (sk->sk_prot->bind) {
+		err = sk->sk_prot->bind(sk, uaddr, addr_len);
+		goto out;
+	}
+	err = -EINVAL;
+	if (addr_len < sizeof(struct sockaddr_in))
+		goto out;
+
+	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
+
+	/* Not specified by any standard per-se, however it breaks too
+	 * many applications when removed.  It is unfortunate since
+	 * allowing applications to make a non-local bind solves
+	 * several problems with systems using dynamic addressing.
+	 * (ie. your servers still start up even if your ISDN link
+	 *  is temporarily down)
+	 */
+	err = -EADDRNOTAVAIL;
+	if (!sysctl_ip_nonlocal_bind &&
+	    !(inet->freebind || inet->transparent) &&
+	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
+	    chk_addr_ret != RTN_LOCAL &&
+	    chk_addr_ret != RTN_MULTICAST &&
+	    chk_addr_ret != RTN_BROADCAST)
+		goto out;
+
+	snum = ntohs(addr->sin_port);
+	err = -EACCES;
+	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
+		goto out;
+
+	/*      We keep a pair of addresses. rcv_saddr is the one
+	 *      used by hash lookups, and saddr is used for transmit.
+	 *
+	 *      In the BSD API these are the same except where it
+	 *      would be illegal to use them (multicast/broadcast) in
+	 *      which case the sending device address is used.
+	 */
+	lock_sock(sk);
+
+	/* Check these errors (active socket, double bind). */
+	err = -EINVAL;
+	if (sk->sk_state != TCP_CLOSE || inet->num)
+		goto out_release_sock;
+
+	inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
+	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
+		inet->saddr = 0;  /* Use device */
+
+	/* Make sure we are allowed to bind here. */
+	if (sk->sk_prot->get_port(sk, snum)) {
+		inet->saddr = inet->rcv_saddr = 0;
+		err = -EADDRINUSE;
+		goto out_release_sock;
+	}
+
+	if (inet->rcv_saddr)
+		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
+	if (snum)
+		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
+	inet->sport = htons(inet->num);
+	inet->daddr = 0;
+	inet->dport = 0;
+	sk_dst_reset(sk);
+	err = 0;
+out_release_sock:
+	release_sock(sk);
+out:
+	return err;
+}
+
+int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
+		       int addr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+
+	if (uaddr->sa_family == AF_UNSPEC)
+		return sk->sk_prot->disconnect(sk, flags);
+
+	if (!inet_sk(sk)->num && inet_autobind(sk))
+		return -EAGAIN;
+	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
+}
+
+static long inet_wait_for_connect(struct sock *sk, long timeo)
+{
+	DEFINE_WAIT(wait);
+
+	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+
+	/* Basic assumption: if someone sets sk->sk_err, he _must_
+	 * change state of the socket from TCP_SYN_*.
+	 * Connect() does not allow to get error notifications
+	 * without closing the socket.
+	 */
+	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		release_sock(sk);
+		timeo = schedule_timeout(timeo);
+		lock_sock(sk);
+		if (signal_pending(current) || !timeo)
+			break;
+		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+	}
+	finish_wait(sk->sk_sleep, &wait);
+	return timeo;
+}
+
+/*
+ *	Connect to a remote host. There is regrettably still a little
+ *	TCP 'magic' in here.
+ */
+int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
+			int addr_len, int flags)
+{
+	struct sock *sk = sock->sk;
+	int err;
+	long timeo;
+
+	lock_sock(sk);
+
+	if (uaddr->sa_family == AF_UNSPEC) {
+		err = sk->sk_prot->disconnect(sk, flags);
+		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
+		goto out;
+	}
+
+	switch (sock->state) {
+	default:
+		err = -EINVAL;
+		goto out;
+	case SS_CONNECTED:
+		err = -EISCONN;
+		goto out;
+	case SS_CONNECTING:
+		err = -EALREADY;
+		/* Fall out of switch with err, set for this state */
+		break;
+	case SS_UNCONNECTED:
+		err = -EISCONN;
+		if (sk->sk_state != TCP_CLOSE)
+			goto out;
+
+		err = sk->sk_prot->connect(sk, uaddr, addr_len);
+		if (err < 0)
+			goto out;
+
+		sock->state = SS_CONNECTING;
+
+		/* Just entered SS_CONNECTING state; the only
+		 * difference is that return value in non-blocking
+		 * case is EINPROGRESS, rather than EALREADY.
+		 */
+		err = -EINPROGRESS;
+		break;
+	}
+
+	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
+
+	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		/* Error code is set above */
+		if (!timeo || !inet_wait_for_connect(sk, timeo))
+			goto out;
+
+		err = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			goto out;
+	}
+
+	/* Connection was closed by RST, timeout, ICMP error
+	 * or another process disconnected us.
+	 */
+	if (sk->sk_state == TCP_CLOSE)
+		goto sock_error;
+
+	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
+	 * and error was received after socket entered established state.
+	 * Hence, it is handled normally after connect() return successfully.
+	 */
+
+	sock->state = SS_CONNECTED;
+	err = 0;
+out:
+	release_sock(sk);
+	return err;
+
+sock_error:
+	err = sock_error(sk) ? : -ECONNABORTED;
+	sock->state = SS_UNCONNECTED;
+	if (sk->sk_prot->disconnect(sk, flags))
+		sock->state = SS_DISCONNECTING;
+	goto out;
+}
+
+/*
+ *	Accept a pending connection. The TCP layer now gives BSD semantics.
+ */
+
+int inet_accept(struct socket *sock, struct socket *newsock, int flags)
+{
+	struct sock *sk1 = sock->sk;
+	int err = -EINVAL;
+	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
+
+	if (!sk2)
+		goto do_err;
+
+	lock_sock(sk2);
+
+	WARN_ON(!((1 << sk2->sk_state) &
+		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
+
+	sock_graft(sk2, newsock);
+
+	newsock->state = SS_CONNECTED;
+	err = 0;
+	release_sock(sk2);
+do_err:
+	return err;
+}
+
+
+/*
+ *	This does both peername and sockname.
+ */
+int inet_getname(struct socket *sock, struct sockaddr *uaddr,
+			int *uaddr_len, int peer)
+{
+	struct sock *sk		= sock->sk;
+	struct inet_sock *inet	= inet_sk(sk);
+	struct sockaddr_in *sin	= (struct sockaddr_in *)uaddr;
+
+	sin->sin_family = AF_INET;
+	if (peer) {
+		if (!inet->dport ||
+		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
+		     peer == 1))
+			return -ENOTCONN;
+		sin->sin_port = inet->dport;
+		sin->sin_addr.s_addr = inet->daddr;
+	} else {
+		__be32 addr = inet->rcv_saddr;
+		if (!addr)
+			addr = inet->saddr;
+		sin->sin_port = inet->sport;
+		sin->sin_addr.s_addr = addr;
+	}
+	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+	*uaddr_len = sizeof(*sin);
+	return 0;
+}
+
+int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
+		 size_t size)
+{
+	struct sock *sk = sock->sk;
+
+	/* We may need to bind the socket. */
+	if (!inet_sk(sk)->num && inet_autobind(sk))
+		return -EAGAIN;
+
+	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
+}
+
+
+static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
+{
+	struct sock *sk = sock->sk;
+
+	/* We may need to bind the socket. */
+	if (!inet_sk(sk)->num && inet_autobind(sk))
+		return -EAGAIN;
+
+	if (sk->sk_prot->sendpage)
+		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
+	return sock_no_sendpage(sock, page, offset, size, flags);
+}
+
+
+int inet_shutdown(struct socket *sock, int how)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+
+	/* This should really check to make sure
+	 * the socket is a TCP socket. (WHY AC...)
+	 */
+	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
+		       1->2 bit 2 snds.
+		       2->3 */
+	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
+		return -EINVAL;
+
+	lock_sock(sk);
+	if (sock->state == SS_CONNECTING) {
+		if ((1 << sk->sk_state) &
+		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
+			sock->state = SS_DISCONNECTING;
+		else
+			sock->state = SS_CONNECTED;
+	}
+
+	switch (sk->sk_state) {
+	case TCP_CLOSE:
+		err = -ENOTCONN;
+		/* Hack to wake up other listeners, who can poll for
+		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
+	default:
+		sk->sk_shutdown |= how;
+		if (sk->sk_prot->shutdown)
+			sk->sk_prot->shutdown(sk, how);
+		break;
+
+	/* Remaining two branches are temporary solution for missing
+	 * close() in multithreaded environment. It is _not_ a good idea,
+	 * but we have no choice until close() is repaired at VFS level.
+	 */
+	case TCP_LISTEN:
+		if (!(how & RCV_SHUTDOWN))
+			break;
+		/* Fall through */
+	case TCP_SYN_SENT:
+		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
+		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
+		break;
+	}
+
+	/* Wake up anyone sleeping in poll. */
+	sk->sk_state_change(sk);
+	release_sock(sk);
+	return err;
+}
+
+/*
+ *	ioctl() calls you can issue on an INET socket. Most of these are
+ *	device configuration and stuff and very rarely used. Some ioctls
+ *	pass on to the socket itself.
+ *
+ *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
+ *	loads the devconfigure module does its configuring and unloads it.
+ *	There's a good 20K of config code hanging around the kernel.
+ */
+
+int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	struct sock *sk = sock->sk;
+	int err = 0;
+	struct net *net = sock_net(sk);
+
+	switch (cmd) {
+		case SIOCGSTAMP:
+			err = sock_get_timestamp(sk, (struct timeval __user *)arg);
+			break;
+		case SIOCGSTAMPNS:
+			err = sock_get_timestampns(sk, (struct timespec __user *)arg);
+			break;
+		case SIOCADDRT:
+		case SIOCDELRT:
+		case SIOCRTMSG:
+			err = ip_rt_ioctl(net, cmd, (void __user *)arg);
+			break;
+		case SIOCDARP:
+		case SIOCGARP:
+		case SIOCSARP:
+			err = arp_ioctl(net, cmd, (void __user *)arg);
+			break;
+		case SIOCGIFADDR:
+		case SIOCSIFADDR:
+		case SIOCGIFBRDADDR:
+		case SIOCSIFBRDADDR:
+		case SIOCGIFNETMASK:
+		case SIOCSIFNETMASK:
+		case SIOCGIFDSTADDR:
+		case SIOCSIFDSTADDR:
+		case SIOCSIFPFLAGS:
+		case SIOCGIFPFLAGS:
+		case SIOCSIFFLAGS:
+			err = devinet_ioctl(net, cmd, (void __user *)arg);
+			break;
+		default:
+			if (sk->sk_prot->ioctl)
+				err = sk->sk_prot->ioctl(sk, cmd, arg);
+			else
+				err = -ENOIOCTLCMD;
+			break;
+	}
+	return err;
+}
+
+const struct proto_ops inet_stream_ops = {
+	.family		   = PF_INET,
+	.owner		   = THIS_MODULE,
+	.release	   = inet_release,
+	.bind		   = inet_bind,
+	.connect	   = inet_stream_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = inet_accept,
+	.getname	   = inet_getname,
+	.poll		   = tcp_poll,
+	.ioctl		   = inet_ioctl,
+	.listen		   = inet_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = tcp_sendmsg,
+	.recvmsg	   = sock_common_recvmsg,
+	.mmap		   = sock_no_mmap,
+	.sendpage	   = tcp_sendpage,
+	.splice_read	   = tcp_splice_read,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_sock_common_setsockopt,
+	.compat_getsockopt = compat_sock_common_getsockopt,
+#endif
+};
+
+const struct proto_ops inet_dgram_ops = {
+	.family		   = PF_INET,
+	.owner		   = THIS_MODULE,
+	.release	   = inet_release,
+	.bind		   = inet_bind,
+	.connect	   = inet_dgram_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = sock_no_accept,
+	.getname	   = inet_getname,
+	.poll		   = udp_poll,
+	.ioctl		   = inet_ioctl,
+	.listen		   = sock_no_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = inet_sendmsg,
+	.recvmsg	   = sock_common_recvmsg,
+	.mmap		   = sock_no_mmap,
+	.sendpage	   = inet_sendpage,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_sock_common_setsockopt,
+	.compat_getsockopt = compat_sock_common_getsockopt,
+#endif
+};
+
+/*
+ * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
+ * udp_poll
+ */
+static const struct proto_ops inet_sockraw_ops = {
+	.family		   = PF_INET,
+	.owner		   = THIS_MODULE,
+	.release	   = inet_release,
+	.bind		   = inet_bind,
+	.connect	   = inet_dgram_connect,
+	.socketpair	   = sock_no_socketpair,
+	.accept		   = sock_no_accept,
+	.getname	   = inet_getname,
+	.poll		   = datagram_poll,
+	.ioctl		   = inet_ioctl,
+	.listen		   = sock_no_listen,
+	.shutdown	   = inet_shutdown,
+	.setsockopt	   = sock_common_setsockopt,
+	.getsockopt	   = sock_common_getsockopt,
+	.sendmsg	   = inet_sendmsg,
+	.recvmsg	   = sock_common_recvmsg,
+	.mmap		   = sock_no_mmap,
+	.sendpage	   = inet_sendpage,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_sock_common_setsockopt,
+	.compat_getsockopt = compat_sock_common_getsockopt,
+#endif
+};
+
+static struct net_proto_family inet_family_ops = {
+	.family = PF_INET,
+	.create = inet_create,
+	.owner	= THIS_MODULE,
+};
+
+/* Upon startup we insert all the elements in inetsw_array[] into
+ * the linked list inetsw.
+ */
+static struct inet_protosw inetsw_array[] =
+{
+	{
+		.type =       SOCK_STREAM,
+		.protocol =   IPPROTO_TCP,
+		.prot =       &tcp_prot,
+		.ops =        &inet_stream_ops,
+		.capability = -1,
+		.no_check =   0,
+		.flags =      INET_PROTOSW_PERMANENT |
+			      INET_PROTOSW_ICSK,
+	},
+
+	{
+		.type =       SOCK_DGRAM,
+		.protocol =   IPPROTO_UDP,
+		.prot =       &udp_prot,
+		.ops =        &inet_dgram_ops,
+		.capability = -1,
+		.no_check =   UDP_CSUM_DEFAULT,
+		.flags =      INET_PROTOSW_PERMANENT,
+       },
+
+
+       {
+	       .type =       SOCK_RAW,
+	       .protocol =   IPPROTO_IP,	/* wild card */
+	       .prot =       &raw_prot,
+	       .ops =        &inet_sockraw_ops,
+	       .capability = CAP_NET_RAW,
+	       .no_check =   UDP_CSUM_DEFAULT,
+	       .flags =      INET_PROTOSW_REUSE,
+       }
+};
+
+#define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
+
+void inet_register_protosw(struct inet_protosw *p)
+{
+	struct list_head *lh;
+	struct inet_protosw *answer;
+	int protocol = p->protocol;
+	struct list_head *last_perm;
+
+	spin_lock_bh(&inetsw_lock);
+
+	if (p->type >= SOCK_MAX)
+		goto out_illegal;
+
+	/* If we are trying to override a permanent protocol, bail. */
+	answer = NULL;
+	last_perm = &inetsw[p->type];
+	list_for_each(lh, &inetsw[p->type]) {
+		answer = list_entry(lh, struct inet_protosw, list);
+
+		/* Check only the non-wild match. */
+		if (INET_PROTOSW_PERMANENT & answer->flags) {
+			if (protocol == answer->protocol)
+				break;
+			last_perm = lh;
+		}
+
+		answer = NULL;
+	}
+	if (answer)
+		goto out_permanent;
+
+	/* Add the new entry after the last permanent entry if any, so that
+	 * the new entry does not override a permanent entry when matched with
+	 * a wild-card protocol. But it is allowed to override any existing
+	 * non-permanent entry.  This means that when we remove this entry, the
+	 * system automatically returns to the old behavior.
+	 */
+	list_add_rcu(&p->list, last_perm);
+out:
+	spin_unlock_bh(&inetsw_lock);
+
+	synchronize_net();
+
+	return;
+
+out_permanent:
+	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
+	       protocol);
+	goto out;
+
+out_illegal:
+	printk(KERN_ERR
+	       "Ignoring attempt to register invalid socket type %d.\n",
+	       p->type);
+	goto out;
+}
+
+void inet_unregister_protosw(struct inet_protosw *p)
+{
+	if (INET_PROTOSW_PERMANENT & p->flags) {
+		printk(KERN_ERR
+		       "Attempt to unregister permanent protocol %d.\n",
+		       p->protocol);
+	} else {
+		spin_lock_bh(&inetsw_lock);
+		list_del_rcu(&p->list);
+		spin_unlock_bh(&inetsw_lock);
+
+		synchronize_net();
+	}
+}
+
+/*
+ *      Shall we try to damage output packets if routing dev changes?
+ */
+
+int sysctl_ip_dynaddr __read_mostly;
+
+static int inet_sk_reselect_saddr(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	int err;
+	struct rtable *rt;
+	__be32 old_saddr = inet->saddr;
+	__be32 new_saddr;
+	__be32 daddr = inet->daddr;
+
+	if (inet->opt && inet->opt->srr)
+		daddr = inet->opt->faddr;
+
+	/* Query new route. */
+	err = ip_route_connect(&rt, daddr, 0,
+			       RT_CONN_FLAGS(sk),
+			       sk->sk_bound_dev_if,
+			       sk->sk_protocol,
+			       inet->sport, inet->dport, sk, 0);
+	if (err)
+		return err;
+
+	sk_setup_caps(sk, &rt->u.dst);
+
+	new_saddr = rt->rt_src;
+
+	if (new_saddr == old_saddr)
+		return 0;
+
+	if (sysctl_ip_dynaddr > 1) {
+		printk(KERN_INFO "%s(): shifting inet->"
+				 "saddr from " NIPQUAD_FMT " to " NIPQUAD_FMT "\n",
+		       __func__,
+		       NIPQUAD(old_saddr),
+		       NIPQUAD(new_saddr));
+	}
+
+	inet->saddr = inet->rcv_saddr = new_saddr;
+
+	/*
+	 * XXX The only one ugly spot where we need to
+	 * XXX really change the sockets identity after
+	 * XXX it has entered the hashes. -DaveM
+	 *
+	 * Besides that, it does not check for connection
+	 * uniqueness. Wait for troubles.
+	 */
+	__sk_prot_rehash(sk);
+	return 0;
+}
+
+int inet_sk_rebuild_header(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
+	__be32 daddr;
+	int err;
+
+	/* Route is OK, nothing to do. */
+	if (rt)
+		return 0;
+
+	/* Reroute. */
+	daddr = inet->daddr;
+	if (inet->opt && inet->opt->srr)
+		daddr = inet->opt->faddr;
+{
+	struct flowi fl = {
+		.oif = sk->sk_bound_dev_if,
+		.nl_u = {
+			.ip4_u = {
+				.daddr	= daddr,
+				.saddr	= inet->saddr,
+				.tos	= RT_CONN_FLAGS(sk),
+			},
+		},
+		.proto = sk->sk_protocol,
+		.flags = inet_sk_flowi_flags(sk),
+		.uli_u = {
+			.ports = {
+				.sport = inet->sport,
+				.dport = inet->dport,
+			},
+		},
+	};
+
+	security_sk_classify_flow(sk, &fl);
+	err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
+}
+	if (!err)
+		sk_setup_caps(sk, &rt->u.dst);
+	else {
+		/* Routing failed... */
+		sk->sk_route_caps = 0;
+		/*
+		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
+		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
+		 */
+		if (!sysctl_ip_dynaddr ||
+		    sk->sk_state != TCP_SYN_SENT ||
+		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
+		    (err = inet_sk_reselect_saddr(sk)) != 0)
+			sk->sk_err_soft = -err;
+	}
+
+	return err;
+}
+
+EXPORT_SYMBOL(inet_sk_rebuild_header);
+
+static int inet_gso_send_check(struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	struct net_protocol *ops;
+	int proto;
+	int ihl;
+	int err = -EINVAL;
+
+	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
+		goto out;
+
+	iph = ip_hdr(skb);
+	ihl = iph->ihl * 4;
+	if (ihl < sizeof(*iph))
+		goto out;
+
+	if (unlikely(!pskb_may_pull(skb, ihl)))
+		goto out;
+
+	__skb_pull(skb, ihl);
+	skb_reset_transport_header(skb);
+	iph = ip_hdr(skb);
+	proto = iph->protocol & (MAX_INET_PROTOS - 1);
+	err = -EPROTONOSUPPORT;
+
+	rcu_read_lock();
+	ops = rcu_dereference(inet_protos[proto]);
+	if (likely(ops && ops->gso_send_check))
+		err = ops->gso_send_check(skb);
+	rcu_read_unlock();
+
+out:
+	return err;
+}
+
+static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
+{
+	struct sk_buff *segs = ERR_PTR(-EINVAL);
+	struct iphdr *iph;
+	struct net_protocol *ops;
+	int proto;
+	int ihl;
+	int id;
+
+	if (!(features & NETIF_F_V4_CSUM))
+		features &= ~NETIF_F_SG;
+
+	if (unlikely(skb_shinfo(skb)->gso_type &
+		     ~(SKB_GSO_TCPV4 |
+		       SKB_GSO_UDP |
+		       SKB_GSO_DODGY |
+		       SKB_GSO_TCP_ECN |
+		       0)))
+		goto out;
+
+	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
+		goto out;
+
+	iph = ip_hdr(skb);
+	ihl = iph->ihl * 4;
+	if (ihl < sizeof(*iph))
+		goto out;
+
+	if (unlikely(!pskb_may_pull(skb, ihl)))
+		goto out;
+
+	__skb_pull(skb, ihl);
+	skb_reset_transport_header(skb);
+	iph = ip_hdr(skb);
+	id = ntohs(iph->id);
+	proto = iph->protocol & (MAX_INET_PROTOS - 1);
+	segs = ERR_PTR(-EPROTONOSUPPORT);
+
+	rcu_read_lock();
+	ops = rcu_dereference(inet_protos[proto]);
+	if (likely(ops && ops->gso_segment))
+		segs = ops->gso_segment(skb, features);
+	rcu_read_unlock();
+
+	if (!segs || IS_ERR(segs))
+		goto out;
+
+	skb = segs;
+	do {
+		iph = ip_hdr(skb);
+		iph->id = htons(id++);
+		iph->tot_len = htons(skb->len - skb->mac_len);
+		iph->check = 0;
+		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
+	} while ((skb = skb->next));
+
+out:
+	return segs;
+}
+
+int inet_ctl_sock_create(struct sock **sk, unsigned short family,
+			 unsigned short type, unsigned char protocol,
+			 struct net *net)
+{
+	struct socket *sock;
+	int rc = sock_create_kern(family, type, protocol, &sock);
+
+	if (rc == 0) {
+		*sk = sock->sk;
+		(*sk)->sk_allocation = GFP_ATOMIC;
+		/*
+		 * Unhash it so that IP input processing does not even see it,
+		 * we do not wish this socket to see incoming packets.
+		 */
+		(*sk)->sk_prot->unhash(*sk);
+
+		sk_change_net(*sk, net);
+	}
+	return rc;
+}
+
+EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
+
+unsigned long snmp_fold_field(void *mib[], int offt)
+{
+	unsigned long res = 0;
+	int i;
+
+	for_each_possible_cpu(i) {
+		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
+		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
+	}
+	return res;
+}
+EXPORT_SYMBOL_GPL(snmp_fold_field);
+
+int snmp_mib_init(void *ptr[2], size_t mibsize)
+{
+	BUG_ON(ptr == NULL);
+	ptr[0] = __alloc_percpu(mibsize);
+	if (!ptr[0])
+		goto err0;
+	ptr[1] = __alloc_percpu(mibsize);
+	if (!ptr[1])
+		goto err1;
+	return 0;
+err1:
+	free_percpu(ptr[0]);
+	ptr[0] = NULL;
+err0:
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(snmp_mib_init);
+
+void snmp_mib_free(void *ptr[2])
+{
+	BUG_ON(ptr == NULL);
+	free_percpu(ptr[0]);
+	free_percpu(ptr[1]);
+	ptr[0] = ptr[1] = NULL;
+}
+EXPORT_SYMBOL_GPL(snmp_mib_free);
+
+#ifdef CONFIG_IP_MULTICAST
+static struct net_protocol igmp_protocol = {
+	.handler =	igmp_rcv,
+};
+#endif
+
+static struct net_protocol tcp_protocol = {
+	.handler =	tcp_v4_rcv,
+	.err_handler =	tcp_v4_err,
+	.gso_send_check = tcp_v4_gso_send_check,
+	.gso_segment =	tcp_tso_segment,
+	.no_policy =	1,
+	.netns_ok =	1,
+};
+
+static struct net_protocol udp_protocol = {
+	.handler =	udp_rcv,
+	.err_handler =	udp_err,
+	.no_policy =	1,
+	.netns_ok =	1,
+};
+
+static struct net_protocol icmp_protocol = {
+	.handler =	icmp_rcv,
+	.no_policy =	1,
+	.netns_ok =	1,
+};
+
+static __net_init int ipv4_mib_init_net(struct net *net)
+{
+	if (snmp_mib_init((void **)net->mib.tcp_statistics,
+			  sizeof(struct tcp_mib)) < 0)
+		goto err_tcp_mib;
+	if (snmp_mib_init((void **)net->mib.ip_statistics,
+			  sizeof(struct ipstats_mib)) < 0)
+		goto err_ip_mib;
+	if (snmp_mib_init((void **)net->mib.net_statistics,
+			  sizeof(struct linux_mib)) < 0)
+		goto err_net_mib;
+	if (snmp_mib_init((void **)net->mib.udp_statistics,
+			  sizeof(struct udp_mib)) < 0)
+		goto err_udp_mib;
+	if (snmp_mib_init((void **)net->mib.udplite_statistics,
+			  sizeof(struct udp_mib)) < 0)
+		goto err_udplite_mib;
+	if (snmp_mib_init((void **)net->mib.icmp_statistics,
+			  sizeof(struct icmp_mib)) < 0)
+		goto err_icmp_mib;
+	if (snmp_mib_init((void **)net->mib.icmpmsg_statistics,
+			  sizeof(struct icmpmsg_mib)) < 0)
+		goto err_icmpmsg_mib;
+
+	tcp_mib_init(net);
+	return 0;
+
+err_icmpmsg_mib:
+	snmp_mib_free((void **)net->mib.icmp_statistics);
+err_icmp_mib:
+	snmp_mib_free((void **)net->mib.udplite_statistics);
+err_udplite_mib:
+	snmp_mib_free((void **)net->mib.udp_statistics);
+err_udp_mib:
+	snmp_mib_free((void **)net->mib.net_statistics);
+err_net_mib:
+	snmp_mib_free((void **)net->mib.ip_statistics);
+err_ip_mib:
+	snmp_mib_free((void **)net->mib.tcp_statistics);
+err_tcp_mib:
+	return -ENOMEM;
+}
+
+static __net_exit void ipv4_mib_exit_net(struct net *net)
+{
+	snmp_mib_free((void **)net->mib.icmpmsg_statistics);
+	snmp_mib_free((void **)net->mib.icmp_statistics);
+	snmp_mib_free((void **)net->mib.udplite_statistics);
+	snmp_mib_free((void **)net->mib.udp_statistics);
+	snmp_mib_free((void **)net->mib.net_statistics);
+	snmp_mib_free((void **)net->mib.ip_statistics);
+	snmp_mib_free((void **)net->mib.tcp_statistics);
+}
+
+static __net_initdata struct pernet_operations ipv4_mib_ops = {
+	.init = ipv4_mib_init_net,
+	.exit = ipv4_mib_exit_net,
+};
+
+static int __init init_ipv4_mibs(void)
+{
+	return register_pernet_subsys(&ipv4_mib_ops);
+}
+
+static int ipv4_proc_init(void);
+
+/*
+ *	IP protocol layer initialiser
+ */
+
+static struct packet_type ip_packet_type = {
+	.type = __constant_htons(ETH_P_IP),
+	.func = ip_rcv,
+	.gso_send_check = inet_gso_send_check,
+	.gso_segment = inet_gso_segment,
+};
+
+static int __init inet_init(void)
+{
+	struct sk_buff *dummy_skb;
+	struct inet_protosw *q;
+	struct list_head *r;
+	int rc = -EINVAL;
+
+	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
+
+	rc = proto_register(&tcp_prot, 1);
+	if (rc)
+		goto out;
+
+	rc = proto_register(&udp_prot, 1);
+	if (rc)
+		goto out_unregister_tcp_proto;
+
+	rc = proto_register(&raw_prot, 1);
+	if (rc)
+		goto out_unregister_udp_proto;
+
+	/*
+	 *	Tell SOCKET that we are alive...
+	 */
+
+	(void)sock_register(&inet_family_ops);
+
+#ifdef CONFIG_SYSCTL
+	ip_static_sysctl_init();
+#endif
+
+	/*
+	 *	Add all the base protocols.
+	 */
+
+	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
+		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
+	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
+		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
+	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
+		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
+#ifdef CONFIG_IP_MULTICAST
+	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
+		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
+#endif
+
+	/* Register the socket-side information for inet_create. */
+	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
+		INIT_LIST_HEAD(r);
+
+	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
+		inet_register_protosw(q);
+
+	/*
+	 *	Set the ARP module up
+	 */
+
+	arp_init();
+
+	/*
+	 *	Set the IP module up
+	 */
+
+	ip_init();
+
+	tcp_v4_init();
+
+	/* Setup TCP slab cache for open requests. */
+	tcp_init();
+
+	/* Setup UDP memory threshold */
+	udp_init();
+
+	/* Add UDP-Lite (RFC 3828) */
+	udplite4_register();
+
+	/*
+	 *	Set the ICMP layer up
+	 */
+
+	if (icmp_init() < 0)
+		panic("Failed to create the ICMP control socket.\n");
+
+	/*
+	 *	Initialise the multicast router
+	 */
+#if defined(CONFIG_IP_MROUTE)
+	if (ip_mr_init())
+		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
+#endif
+	/*
+	 *	Initialise per-cpu ipv4 mibs
+	 */
+
+	if (init_ipv4_mibs())
+		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
+
+	ipv4_proc_init();
+
+	ipfrag_init();
+
+	dev_add_pack(&ip_packet_type);
+
+	rc = 0;
+out:
+	return rc;
+out_unregister_udp_proto:
+	proto_unregister(&udp_prot);
+out_unregister_tcp_proto:
+	proto_unregister(&tcp_prot);
+	goto out;
+}
+
+fs_initcall(inet_init);
+
+/* ------------------------------------------------------------------------ */
+
+#ifdef CONFIG_PROC_FS
+static int __init ipv4_proc_init(void)
+{
+	int rc = 0;
+
+	if (raw_proc_init())
+		goto out_raw;
+	if (tcp4_proc_init())
+		goto out_tcp;
+	if (udp4_proc_init())
+		goto out_udp;
+	if (ip_misc_proc_init())
+		goto out_misc;
+out:
+	return rc;
+out_misc:
+	udp4_proc_exit();
+out_udp:
+	tcp4_proc_exit();
+out_tcp:
+	raw_proc_exit();
+out_raw:
+	rc = -ENOMEM;
+	goto out;
+}
+
+#else /* CONFIG_PROC_FS */
+static int __init ipv4_proc_init(void)
+{
+	return 0;
+}
+#endif /* CONFIG_PROC_FS */
+
+MODULE_ALIAS_NETPROTO(PF_INET);
+
+EXPORT_SYMBOL(inet_accept);
+EXPORT_SYMBOL(inet_bind);
+EXPORT_SYMBOL(inet_dgram_connect);
+EXPORT_SYMBOL(inet_dgram_ops);
+EXPORT_SYMBOL(inet_getname);
+EXPORT_SYMBOL(inet_ioctl);
+EXPORT_SYMBOL(inet_listen);
+EXPORT_SYMBOL(inet_register_protosw);
+EXPORT_SYMBOL(inet_release);
+EXPORT_SYMBOL(inet_sendmsg);
+EXPORT_SYMBOL(inet_shutdown);
+EXPORT_SYMBOL(inet_sock_destruct);
+EXPORT_SYMBOL(inet_stream_connect);
+EXPORT_SYMBOL(inet_stream_ops);
+EXPORT_SYMBOL(inet_unregister_protosw);
+EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
new file mode 100644
index 0000000..8219b7e
--- /dev/null
+++ b/net/ipv4/ah4.c
@@ -0,0 +1,346 @@
+#include <linux/err.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/ah.h>
+#include <linux/crypto.h>
+#include <linux/pfkeyv2.h>
+#include <linux/spinlock.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+
+
+/* Clear mutable options and find final destination to substitute
+ * into IP header for icv calculation. Options are already checked
+ * for validity, so paranoia is not required. */
+
+static int ip_clear_mutable_options(struct iphdr *iph, __be32 *daddr)
+{
+	unsigned char * optptr = (unsigned char*)(iph+1);
+	int  l = iph->ihl*4 - sizeof(struct iphdr);
+	int  optlen;
+
+	while (l > 0) {
+		switch (*optptr) {
+		case IPOPT_END:
+			return 0;
+		case IPOPT_NOOP:
+			l--;
+			optptr++;
+			continue;
+		}
+		optlen = optptr[1];
+		if (optlen<2 || optlen>l)
+			return -EINVAL;
+		switch (*optptr) {
+		case IPOPT_SEC:
+		case 0x85:	/* Some "Extended Security" crap. */
+		case IPOPT_CIPSO:
+		case IPOPT_RA:
+		case 0x80|21:	/* RFC1770 */
+			break;
+		case IPOPT_LSRR:
+		case IPOPT_SSRR:
+			if (optlen < 6)
+				return -EINVAL;
+			memcpy(daddr, optptr+optlen-4, 4);
+			/* Fall through */
+		default:
+			memset(optptr, 0, optlen);
+		}
+		l -= optlen;
+		optptr += optlen;
+	}
+	return 0;
+}
+
+static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int err;
+	struct iphdr *iph, *top_iph;
+	struct ip_auth_hdr *ah;
+	struct ah_data *ahp;
+	union {
+		struct iphdr	iph;
+		char 		buf[60];
+	} tmp_iph;
+
+	skb_push(skb, -skb_network_offset(skb));
+	top_iph = ip_hdr(skb);
+	iph = &tmp_iph.iph;
+
+	iph->tos = top_iph->tos;
+	iph->ttl = top_iph->ttl;
+	iph->frag_off = top_iph->frag_off;
+
+	if (top_iph->ihl != 5) {
+		iph->daddr = top_iph->daddr;
+		memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
+		err = ip_clear_mutable_options(top_iph, &top_iph->daddr);
+		if (err)
+			goto error;
+	}
+
+	ah = ip_auth_hdr(skb);
+	ah->nexthdr = *skb_mac_header(skb);
+	*skb_mac_header(skb) = IPPROTO_AH;
+
+	top_iph->tos = 0;
+	top_iph->tot_len = htons(skb->len);
+	top_iph->frag_off = 0;
+	top_iph->ttl = 0;
+	top_iph->check = 0;
+
+	ahp = x->data;
+	ah->hdrlen  = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
+
+	ah->reserved = 0;
+	ah->spi = x->id.spi;
+	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
+
+	spin_lock_bh(&x->lock);
+	err = ah_mac_digest(ahp, skb, ah->auth_data);
+	memcpy(ah->auth_data, ahp->work_icv, ahp->icv_trunc_len);
+	spin_unlock_bh(&x->lock);
+
+	if (err)
+		goto error;
+
+	top_iph->tos = iph->tos;
+	top_iph->ttl = iph->ttl;
+	top_iph->frag_off = iph->frag_off;
+	if (top_iph->ihl != 5) {
+		top_iph->daddr = iph->daddr;
+		memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
+	}
+
+	err = 0;
+
+error:
+	return err;
+}
+
+static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int ah_hlen;
+	int ihl;
+	int nexthdr;
+	int err = -EINVAL;
+	struct iphdr *iph;
+	struct ip_auth_hdr *ah;
+	struct ah_data *ahp;
+	char work_buf[60];
+
+	if (!pskb_may_pull(skb, sizeof(*ah)))
+		goto out;
+
+	ah = (struct ip_auth_hdr *)skb->data;
+	ahp = x->data;
+	nexthdr = ah->nexthdr;
+	ah_hlen = (ah->hdrlen + 2) << 2;
+
+	if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
+	    ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
+		goto out;
+
+	if (!pskb_may_pull(skb, ah_hlen))
+		goto out;
+
+	/* We are going to _remove_ AH header to keep sockets happy,
+	 * so... Later this can change. */
+	if (skb_cloned(skb) &&
+	    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+		goto out;
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	ah = (struct ip_auth_hdr *)skb->data;
+	iph = ip_hdr(skb);
+
+	ihl = skb->data - skb_network_header(skb);
+	memcpy(work_buf, iph, ihl);
+
+	iph->ttl = 0;
+	iph->tos = 0;
+	iph->frag_off = 0;
+	iph->check = 0;
+	if (ihl > sizeof(*iph)) {
+		__be32 dummy;
+		if (ip_clear_mutable_options(iph, &dummy))
+			goto out;
+	}
+
+	spin_lock(&x->lock);
+	{
+		u8 auth_data[MAX_AH_AUTH_LEN];
+
+		memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
+		skb_push(skb, ihl);
+		err = ah_mac_digest(ahp, skb, ah->auth_data);
+		if (err)
+			goto unlock;
+		if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len))
+			err = -EBADMSG;
+	}
+unlock:
+	spin_unlock(&x->lock);
+
+	if (err)
+		goto out;
+
+	skb->network_header += ah_hlen;
+	memcpy(skb_network_header(skb), work_buf, ihl);
+	skb->transport_header = skb->network_header;
+	__skb_pull(skb, ah_hlen + ihl);
+
+	return nexthdr;
+
+out:
+	return err;
+}
+
+static void ah4_err(struct sk_buff *skb, u32 info)
+{
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+(iph->ihl<<2));
+	struct xfrm_state *x;
+
+	if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
+	    icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+		return;
+
+	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET);
+	if (!x)
+		return;
+	printk(KERN_DEBUG "pmtu discovery on SA AH/%08x/%08x\n",
+	       ntohl(ah->spi), ntohl(iph->daddr));
+	xfrm_state_put(x);
+}
+
+static int ah_init_state(struct xfrm_state *x)
+{
+	struct ah_data *ahp = NULL;
+	struct xfrm_algo_desc *aalg_desc;
+	struct crypto_hash *tfm;
+
+	if (!x->aalg)
+		goto error;
+
+	if (x->encap)
+		goto error;
+
+	ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
+	if (ahp == NULL)
+		return -ENOMEM;
+
+	tfm = crypto_alloc_hash(x->aalg->alg_name, 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(tfm))
+		goto error;
+
+	ahp->tfm = tfm;
+	if (crypto_hash_setkey(tfm, x->aalg->alg_key,
+			       (x->aalg->alg_key_len + 7) / 8))
+		goto error;
+
+	/*
+	 * Lookup the algorithm description maintained by xfrm_algo,
+	 * verify crypto transform properties, and store information
+	 * we need for AH processing.  This lookup cannot fail here
+	 * after a successful crypto_alloc_hash().
+	 */
+	aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
+	BUG_ON(!aalg_desc);
+
+	if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
+	    crypto_hash_digestsize(tfm)) {
+		printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
+		       x->aalg->alg_name, crypto_hash_digestsize(tfm),
+		       aalg_desc->uinfo.auth.icv_fullbits/8);
+		goto error;
+	}
+
+	ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
+	ahp->icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
+
+	BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
+
+	ahp->work_icv = kmalloc(ahp->icv_full_len, GFP_KERNEL);
+	if (!ahp->work_icv)
+		goto error;
+
+	x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
+					  ahp->icv_trunc_len);
+	if (x->props.mode == XFRM_MODE_TUNNEL)
+		x->props.header_len += sizeof(struct iphdr);
+	x->data = ahp;
+
+	return 0;
+
+error:
+	if (ahp) {
+		kfree(ahp->work_icv);
+		crypto_free_hash(ahp->tfm);
+		kfree(ahp);
+	}
+	return -EINVAL;
+}
+
+static void ah_destroy(struct xfrm_state *x)
+{
+	struct ah_data *ahp = x->data;
+
+	if (!ahp)
+		return;
+
+	kfree(ahp->work_icv);
+	ahp->work_icv = NULL;
+	crypto_free_hash(ahp->tfm);
+	ahp->tfm = NULL;
+	kfree(ahp);
+}
+
+
+static const struct xfrm_type ah_type =
+{
+	.description	= "AH4",
+	.owner		= THIS_MODULE,
+	.proto	     	= IPPROTO_AH,
+	.flags		= XFRM_TYPE_REPLAY_PROT,
+	.init_state	= ah_init_state,
+	.destructor	= ah_destroy,
+	.input		= ah_input,
+	.output		= ah_output
+};
+
+static struct net_protocol ah4_protocol = {
+	.handler	=	xfrm4_rcv,
+	.err_handler	=	ah4_err,
+	.no_policy	=	1,
+};
+
+static int __init ah4_init(void)
+{
+	if (xfrm_register_type(&ah_type, AF_INET) < 0) {
+		printk(KERN_INFO "ip ah init: can't add xfrm type\n");
+		return -EAGAIN;
+	}
+	if (inet_add_protocol(&ah4_protocol, IPPROTO_AH) < 0) {
+		printk(KERN_INFO "ip ah init: can't add protocol\n");
+		xfrm_unregister_type(&ah_type, AF_INET);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static void __exit ah4_fini(void)
+{
+	if (inet_del_protocol(&ah4_protocol, IPPROTO_AH) < 0)
+		printk(KERN_INFO "ip ah close: can't remove protocol\n");
+	if (xfrm_unregister_type(&ah_type, AF_INET) < 0)
+		printk(KERN_INFO "ip ah close: can't remove xfrm type\n");
+}
+
+module_init(ah4_init);
+module_exit(ah4_fini);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH);
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
new file mode 100644
index 0000000..1a9dd66
--- /dev/null
+++ b/net/ipv4/arp.c
@@ -0,0 +1,1419 @@
+/* linux/net/ipv4/arp.c
+ *
+ * Copyright (C) 1994 by Florian  La Roche
+ *
+ * This module implements the Address Resolution Protocol ARP (RFC 826),
+ * which is used to convert IP addresses (or in the future maybe other
+ * high-level addresses) into a low-level hardware address (like an Ethernet
+ * address).
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ *		Alan Cox	:	Removed the Ethernet assumptions in
+ *					Florian's code
+ *		Alan Cox	:	Fixed some small errors in the ARP
+ *					logic
+ *		Alan Cox	:	Allow >4K in /proc
+ *		Alan Cox	:	Make ARP add its own protocol entry
+ *		Ross Martin     :       Rewrote arp_rcv() and arp_get_info()
+ *		Stephen Henson	:	Add AX25 support to arp_get_info()
+ *		Alan Cox	:	Drop data when a device is downed.
+ *		Alan Cox	:	Use init_timer().
+ *		Alan Cox	:	Double lock fixes.
+ *		Martin Seine	:	Move the arphdr structure
+ *					to if_arp.h for compatibility.
+ *					with BSD based programs.
+ *		Andrew Tridgell :       Added ARP netmask code and
+ *					re-arranged proxy handling.
+ *		Alan Cox	:	Changed to use notifiers.
+ *		Niibe Yutaka	:	Reply for this device or proxies only.
+ *		Alan Cox	:	Don't proxy across hardware types!
+ *		Jonathan Naylor :	Added support for NET/ROM.
+ *		Mike Shaver     :       RFC1122 checks.
+ *		Jonathan Naylor :	Only lookup the hardware address for
+ *					the correct hardware type.
+ *		Germano Caronni	:	Assorted subtle races.
+ *		Craig Schlenter :	Don't modify permanent entry
+ *					during arp_rcv.
+ *		Russ Nelson	:	Tidied up a few bits.
+ *		Alexey Kuznetsov:	Major changes to caching and behaviour,
+ *					eg intelligent arp probing and
+ *					generation
+ *					of host down events.
+ *		Alan Cox	:	Missing unlock in device events.
+ *		Eckes		:	ARP ioctl control errors.
+ *		Alexey Kuznetsov:	Arp free fix.
+ *		Manuel Rodriguez:	Gratuitous ARP.
+ *              Jonathan Layes  :       Added arpd support through kerneld
+ *                                      message queue (960314)
+ *		Mike Shaver	:	/proc/sys/net/ipv4/arp_* support
+ *		Mike McLagan    :	Routing by source
+ *		Stuart Cheshire	:	Metricom and grat arp fixes
+ *					*** FOR 2.1 clean this up ***
+ *		Lawrence V. Stefani: (08/12/96) Added FDDI support.
+ *		Alan Cox 	:	Took the AP1000 nasty FDDI hack and
+ *					folded into the mainstream FDDI code.
+ *					Ack spit, Linus how did you allow that
+ *					one in...
+ *		Jes Sorensen	:	Make FDDI work again in 2.1.x and
+ *					clean up the APFDDI & gen. FDDI bits.
+ *		Alexey Kuznetsov:	new arp state machine;
+ *					now it is in net/core/neighbour.c.
+ *		Krzysztof Halasa:	Added Frame Relay ARP support.
+ *		Arnaldo C. Melo :	convert /proc/net/arp to seq_file
+ *		Shmulik Hen:		Split arp_send to arp_create and
+ *					arp_xmit so intermediate drivers like
+ *					bonding can change the skb before
+ *					sending (e.g. insert 8021q tag).
+ *		Harald Welte	:	convert to make use of jenkins hash
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/capability.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/mm.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/fddidevice.h>
+#include <linux/if_arp.h>
+#include <linux/trdevice.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <linux/net.h>
+#include <linux/rcupdate.h>
+#include <linux/jhash.h>
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#include <net/ax25.h>
+#include <net/netrom.h>
+#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
+#include <net/atmclip.h>
+struct neigh_table *clip_tbl_hook;
+#endif
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#include <linux/netfilter_arp.h>
+
+/*
+ *	Interface to generic neighbour cache.
+ */
+static u32 arp_hash(const void *pkey, const struct net_device *dev);
+static int arp_constructor(struct neighbour *neigh);
+static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb);
+static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb);
+static void parp_redo(struct sk_buff *skb);
+
+static struct neigh_ops arp_generic_ops = {
+	.family =		AF_INET,
+	.solicit =		arp_solicit,
+	.error_report =		arp_error_report,
+	.output =		neigh_resolve_output,
+	.connected_output =	neigh_connected_output,
+	.hh_output =		dev_queue_xmit,
+	.queue_xmit =		dev_queue_xmit,
+};
+
+static struct neigh_ops arp_hh_ops = {
+	.family =		AF_INET,
+	.solicit =		arp_solicit,
+	.error_report =		arp_error_report,
+	.output =		neigh_resolve_output,
+	.connected_output =	neigh_resolve_output,
+	.hh_output =		dev_queue_xmit,
+	.queue_xmit =		dev_queue_xmit,
+};
+
+static struct neigh_ops arp_direct_ops = {
+	.family =		AF_INET,
+	.output =		dev_queue_xmit,
+	.connected_output =	dev_queue_xmit,
+	.hh_output =		dev_queue_xmit,
+	.queue_xmit =		dev_queue_xmit,
+};
+
+struct neigh_ops arp_broken_ops = {
+	.family =		AF_INET,
+	.solicit =		arp_solicit,
+	.error_report =		arp_error_report,
+	.output =		neigh_compat_output,
+	.connected_output =	neigh_compat_output,
+	.hh_output =		dev_queue_xmit,
+	.queue_xmit =		dev_queue_xmit,
+};
+
+struct neigh_table arp_tbl = {
+	.family =	AF_INET,
+	.entry_size =	sizeof(struct neighbour) + 4,
+	.key_len =	4,
+	.hash =		arp_hash,
+	.constructor =	arp_constructor,
+	.proxy_redo =	parp_redo,
+	.id =		"arp_cache",
+	.parms = {
+		.tbl =			&arp_tbl,
+		.base_reachable_time =	30 * HZ,
+		.retrans_time =	1 * HZ,
+		.gc_staletime =	60 * HZ,
+		.reachable_time =		30 * HZ,
+		.delay_probe_time =	5 * HZ,
+		.queue_len =		3,
+		.ucast_probes =	3,
+		.mcast_probes =	3,
+		.anycast_delay =	1 * HZ,
+		.proxy_delay =		(8 * HZ) / 10,
+		.proxy_qlen =		64,
+		.locktime =		1 * HZ,
+	},
+	.gc_interval =	30 * HZ,
+	.gc_thresh1 =	128,
+	.gc_thresh2 =	512,
+	.gc_thresh3 =	1024,
+};
+
+int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
+{
+	switch (dev->type) {
+	case ARPHRD_ETHER:
+	case ARPHRD_FDDI:
+	case ARPHRD_IEEE802:
+		ip_eth_mc_map(addr, haddr);
+		return 0;
+	case ARPHRD_IEEE802_TR:
+		ip_tr_mc_map(addr, haddr);
+		return 0;
+	case ARPHRD_INFINIBAND:
+		ip_ib_mc_map(addr, dev->broadcast, haddr);
+		return 0;
+	default:
+		if (dir) {
+			memcpy(haddr, dev->broadcast, dev->addr_len);
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+
+static u32 arp_hash(const void *pkey, const struct net_device *dev)
+{
+	return jhash_2words(*(u32 *)pkey, dev->ifindex, arp_tbl.hash_rnd);
+}
+
+static int arp_constructor(struct neighbour *neigh)
+{
+	__be32 addr = *(__be32*)neigh->primary_key;
+	struct net_device *dev = neigh->dev;
+	struct in_device *in_dev;
+	struct neigh_parms *parms;
+
+	rcu_read_lock();
+	in_dev = __in_dev_get_rcu(dev);
+	if (in_dev == NULL) {
+		rcu_read_unlock();
+		return -EINVAL;
+	}
+
+	neigh->type = inet_addr_type(dev_net(dev), addr);
+
+	parms = in_dev->arp_parms;
+	__neigh_parms_put(neigh->parms);
+	neigh->parms = neigh_parms_clone(parms);
+	rcu_read_unlock();
+
+	if (!dev->header_ops) {
+		neigh->nud_state = NUD_NOARP;
+		neigh->ops = &arp_direct_ops;
+		neigh->output = neigh->ops->queue_xmit;
+	} else {
+		/* Good devices (checked by reading texts, but only Ethernet is
+		   tested)
+
+		   ARPHRD_ETHER: (ethernet, apfddi)
+		   ARPHRD_FDDI: (fddi)
+		   ARPHRD_IEEE802: (tr)
+		   ARPHRD_METRICOM: (strip)
+		   ARPHRD_ARCNET:
+		   etc. etc. etc.
+
+		   ARPHRD_IPDDP will also work, if author repairs it.
+		   I did not it, because this driver does not work even
+		   in old paradigm.
+		 */
+
+#if 1
+		/* So... these "amateur" devices are hopeless.
+		   The only thing, that I can say now:
+		   It is very sad that we need to keep ugly obsolete
+		   code to make them happy.
+
+		   They should be moved to more reasonable state, now
+		   they use rebuild_header INSTEAD OF hard_start_xmit!!!
+		   Besides that, they are sort of out of date
+		   (a lot of redundant clones/copies, useless in 2.1),
+		   I wonder why people believe that they work.
+		 */
+		switch (dev->type) {
+		default:
+			break;
+		case ARPHRD_ROSE:
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+		case ARPHRD_AX25:
+#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
+		case ARPHRD_NETROM:
+#endif
+			neigh->ops = &arp_broken_ops;
+			neigh->output = neigh->ops->output;
+			return 0;
+#endif
+		;}
+#endif
+		if (neigh->type == RTN_MULTICAST) {
+			neigh->nud_state = NUD_NOARP;
+			arp_mc_map(addr, neigh->ha, dev, 1);
+		} else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) {
+			neigh->nud_state = NUD_NOARP;
+			memcpy(neigh->ha, dev->dev_addr, dev->addr_len);
+		} else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) {
+			neigh->nud_state = NUD_NOARP;
+			memcpy(neigh->ha, dev->broadcast, dev->addr_len);
+		}
+
+		if (dev->header_ops->cache)
+			neigh->ops = &arp_hh_ops;
+		else
+			neigh->ops = &arp_generic_ops;
+
+		if (neigh->nud_state&NUD_VALID)
+			neigh->output = neigh->ops->connected_output;
+		else
+			neigh->output = neigh->ops->output;
+	}
+	return 0;
+}
+
+static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb)
+{
+	dst_link_failure(skb);
+	kfree_skb(skb);
+}
+
+static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
+{
+	__be32 saddr = 0;
+	u8  *dst_ha = NULL;
+	struct net_device *dev = neigh->dev;
+	__be32 target = *(__be32*)neigh->primary_key;
+	int probes = atomic_read(&neigh->probes);
+	struct in_device *in_dev = in_dev_get(dev);
+
+	if (!in_dev)
+		return;
+
+	switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
+	default:
+	case 0:		/* By default announce any local IP */
+		if (skb && inet_addr_type(dev_net(dev), ip_hdr(skb)->saddr) == RTN_LOCAL)
+			saddr = ip_hdr(skb)->saddr;
+		break;
+	case 1:		/* Restrict announcements of saddr in same subnet */
+		if (!skb)
+			break;
+		saddr = ip_hdr(skb)->saddr;
+		if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
+			/* saddr should be known to target */
+			if (inet_addr_onlink(in_dev, target, saddr))
+				break;
+		}
+		saddr = 0;
+		break;
+	case 2:		/* Avoid secondary IPs, get a primary/preferred one */
+		break;
+	}
+
+	if (in_dev)
+		in_dev_put(in_dev);
+	if (!saddr)
+		saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);
+
+	if ((probes -= neigh->parms->ucast_probes) < 0) {
+		if (!(neigh->nud_state&NUD_VALID))
+			printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n");
+		dst_ha = neigh->ha;
+		read_lock_bh(&neigh->lock);
+	} else if ((probes -= neigh->parms->app_probes) < 0) {
+#ifdef CONFIG_ARPD
+		neigh_app_ns(neigh);
+#endif
+		return;
+	}
+
+	arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr,
+		 dst_ha, dev->dev_addr, NULL);
+	if (dst_ha)
+		read_unlock_bh(&neigh->lock);
+}
+
+static int arp_ignore(struct in_device *in_dev, __be32 sip, __be32 tip)
+{
+	int scope;
+
+	switch (IN_DEV_ARP_IGNORE(in_dev)) {
+	case 0:	/* Reply, the tip is already validated */
+		return 0;
+	case 1:	/* Reply only if tip is configured on the incoming interface */
+		sip = 0;
+		scope = RT_SCOPE_HOST;
+		break;
+	case 2:	/*
+		 * Reply only if tip is configured on the incoming interface
+		 * and is in same subnet as sip
+		 */
+		scope = RT_SCOPE_HOST;
+		break;
+	case 3:	/* Do not reply for scope host addresses */
+		sip = 0;
+		scope = RT_SCOPE_LINK;
+		break;
+	case 4:	/* Reserved */
+	case 5:
+	case 6:
+	case 7:
+		return 0;
+	case 8:	/* Do not reply */
+		return 1;
+	default:
+		return 0;
+	}
+	return !inet_confirm_addr(in_dev, sip, tip, scope);
+}
+
+static int arp_filter(__be32 sip, __be32 tip, struct net_device *dev)
+{
+	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = sip,
+						 .saddr = tip } } };
+	struct rtable *rt;
+	int flag = 0;
+	/*unsigned long now; */
+	struct net *net = dev_net(dev);
+
+	if (ip_route_output_key(net, &rt, &fl) < 0)
+		return 1;
+	if (rt->u.dst.dev != dev) {
+		NET_INC_STATS_BH(net, LINUX_MIB_ARPFILTER);
+		flag = 1;
+	}
+	ip_rt_put(rt);
+	return flag;
+}
+
+/* OBSOLETE FUNCTIONS */
+
+/*
+ *	Find an arp mapping in the cache. If not found, post a request.
+ *
+ *	It is very UGLY routine: it DOES NOT use skb->dst->neighbour,
+ *	even if it exists. It is supposed that skb->dev was mangled
+ *	by a virtual device (eql, shaper). Nobody but broken devices
+ *	is allowed to use this function, it is scheduled to be removed. --ANK
+ */
+
+static int arp_set_predefined(int addr_hint, unsigned char * haddr, __be32 paddr, struct net_device * dev)
+{
+	switch (addr_hint) {
+	case RTN_LOCAL:
+		printk(KERN_DEBUG "ARP: arp called for own IP address\n");
+		memcpy(haddr, dev->dev_addr, dev->addr_len);
+		return 1;
+	case RTN_MULTICAST:
+		arp_mc_map(paddr, haddr, dev, 1);
+		return 1;
+	case RTN_BROADCAST:
+		memcpy(haddr, dev->broadcast, dev->addr_len);
+		return 1;
+	}
+	return 0;
+}
+
+
+int arp_find(unsigned char *haddr, struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	__be32 paddr;
+	struct neighbour *n;
+
+	if (!skb->dst) {
+		printk(KERN_DEBUG "arp_find is called with dst==NULL\n");
+		kfree_skb(skb);
+		return 1;
+	}
+
+	paddr = skb->rtable->rt_gateway;
+
+	if (arp_set_predefined(inet_addr_type(dev_net(dev), paddr), haddr, paddr, dev))
+		return 0;
+
+	n = __neigh_lookup(&arp_tbl, &paddr, dev, 1);
+
+	if (n) {
+		n->used = jiffies;
+		if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) {
+			read_lock_bh(&n->lock);
+			memcpy(haddr, n->ha, dev->addr_len);
+			read_unlock_bh(&n->lock);
+			neigh_release(n);
+			return 0;
+		}
+		neigh_release(n);
+	} else
+		kfree_skb(skb);
+	return 1;
+}
+
+/* END OF OBSOLETE FUNCTIONS */
+
+int arp_bind_neighbour(struct dst_entry *dst)
+{
+	struct net_device *dev = dst->dev;
+	struct neighbour *n = dst->neighbour;
+
+	if (dev == NULL)
+		return -EINVAL;
+	if (n == NULL) {
+		__be32 nexthop = ((struct rtable*)dst)->rt_gateway;
+		if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT))
+			nexthop = 0;
+		n = __neigh_lookup_errno(
+#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
+		    dev->type == ARPHRD_ATM ? clip_tbl_hook :
+#endif
+		    &arp_tbl, &nexthop, dev);
+		if (IS_ERR(n))
+			return PTR_ERR(n);
+		dst->neighbour = n;
+	}
+	return 0;
+}
+
+/*
+ * Check if we can use proxy ARP for this path
+ */
+
+static inline int arp_fwd_proxy(struct in_device *in_dev, struct rtable *rt)
+{
+	struct in_device *out_dev;
+	int imi, omi = -1;
+
+	if (!IN_DEV_PROXY_ARP(in_dev))
+		return 0;
+
+	if ((imi = IN_DEV_MEDIUM_ID(in_dev)) == 0)
+		return 1;
+	if (imi == -1)
+		return 0;
+
+	/* place to check for proxy_arp for routes */
+
+	if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
+		omi = IN_DEV_MEDIUM_ID(out_dev);
+		in_dev_put(out_dev);
+	}
+	return (omi != imi && omi != -1);
+}
+
+/*
+ *	Interface to link layer: send routine and receive handler.
+ */
+
+/*
+ *	Create an arp packet. If (dest_hw == NULL), we create a broadcast
+ *	message.
+ */
+struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
+			   struct net_device *dev, __be32 src_ip,
+			   const unsigned char *dest_hw,
+			   const unsigned char *src_hw,
+			   const unsigned char *target_hw)
+{
+	struct sk_buff *skb;
+	struct arphdr *arp;
+	unsigned char *arp_ptr;
+
+	/*
+	 *	Allocate a buffer
+	 */
+
+	skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
+	if (skb == NULL)
+		return NULL;
+
+	skb_reserve(skb, LL_RESERVED_SPACE(dev));
+	skb_reset_network_header(skb);
+	arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_ARP);
+	if (src_hw == NULL)
+		src_hw = dev->dev_addr;
+	if (dest_hw == NULL)
+		dest_hw = dev->broadcast;
+
+	/*
+	 *	Fill the device header for the ARP frame
+	 */
+	if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
+		goto out;
+
+	/*
+	 * Fill out the arp protocol part.
+	 *
+	 * The arp hardware type should match the device type, except for FDDI,
+	 * which (according to RFC 1390) should always equal 1 (Ethernet).
+	 */
+	/*
+	 *	Exceptions everywhere. AX.25 uses the AX.25 PID value not the
+	 *	DIX code for the protocol. Make these device structure fields.
+	 */
+	switch (dev->type) {
+	default:
+		arp->ar_hrd = htons(dev->type);
+		arp->ar_pro = htons(ETH_P_IP);
+		break;
+
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+	case ARPHRD_AX25:
+		arp->ar_hrd = htons(ARPHRD_AX25);
+		arp->ar_pro = htons(AX25_P_IP);
+		break;
+
+#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
+	case ARPHRD_NETROM:
+		arp->ar_hrd = htons(ARPHRD_NETROM);
+		arp->ar_pro = htons(AX25_P_IP);
+		break;
+#endif
+#endif
+
+#ifdef CONFIG_FDDI
+	case ARPHRD_FDDI:
+		arp->ar_hrd = htons(ARPHRD_ETHER);
+		arp->ar_pro = htons(ETH_P_IP);
+		break;
+#endif
+#ifdef CONFIG_TR
+	case ARPHRD_IEEE802_TR:
+		arp->ar_hrd = htons(ARPHRD_IEEE802);
+		arp->ar_pro = htons(ETH_P_IP);
+		break;
+#endif
+	}
+
+	arp->ar_hln = dev->addr_len;
+	arp->ar_pln = 4;
+	arp->ar_op = htons(type);
+
+	arp_ptr=(unsigned char *)(arp+1);
+
+	memcpy(arp_ptr, src_hw, dev->addr_len);
+	arp_ptr+=dev->addr_len;
+	memcpy(arp_ptr, &src_ip,4);
+	arp_ptr+=4;
+	if (target_hw != NULL)
+		memcpy(arp_ptr, target_hw, dev->addr_len);
+	else
+		memset(arp_ptr, 0, dev->addr_len);
+	arp_ptr+=dev->addr_len;
+	memcpy(arp_ptr, &dest_ip, 4);
+
+	return skb;
+
+out:
+	kfree_skb(skb);
+	return NULL;
+}
+
+/*
+ *	Send an arp packet.
+ */
+void arp_xmit(struct sk_buff *skb)
+{
+	/* Send it off, maybe filter it using firewalling first.  */
+	NF_HOOK(NFPROTO_ARP, NF_ARP_OUT, skb, NULL, skb->dev, dev_queue_xmit);
+}
+
+/*
+ *	Create and send an arp packet.
+ */
+void arp_send(int type, int ptype, __be32 dest_ip,
+	      struct net_device *dev, __be32 src_ip,
+	      const unsigned char *dest_hw, const unsigned char *src_hw,
+	      const unsigned char *target_hw)
+{
+	struct sk_buff *skb;
+
+	/*
+	 *	No arp on this interface.
+	 */
+
+	if (dev->flags&IFF_NOARP)
+		return;
+
+	skb = arp_create(type, ptype, dest_ip, dev, src_ip,
+			 dest_hw, src_hw, target_hw);
+	if (skb == NULL) {
+		return;
+	}
+
+	arp_xmit(skb);
+}
+
+/*
+ *	Process an arp request.
+ */
+
+static int arp_process(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	struct in_device *in_dev = in_dev_get(dev);
+	struct arphdr *arp;
+	unsigned char *arp_ptr;
+	struct rtable *rt;
+	unsigned char *sha;
+	__be32 sip, tip;
+	u16 dev_type = dev->type;
+	int addr_type;
+	struct neighbour *n;
+	struct net *net = dev_net(dev);
+
+	/* arp_rcv below verifies the ARP header and verifies the device
+	 * is ARP'able.
+	 */
+
+	if (in_dev == NULL)
+		goto out;
+
+	arp = arp_hdr(skb);
+
+	switch (dev_type) {
+	default:
+		if (arp->ar_pro != htons(ETH_P_IP) ||
+		    htons(dev_type) != arp->ar_hrd)
+			goto out;
+		break;
+	case ARPHRD_ETHER:
+	case ARPHRD_IEEE802_TR:
+	case ARPHRD_FDDI:
+	case ARPHRD_IEEE802:
+		/*
+		 * ETHERNET, Token Ring and Fibre Channel (which are IEEE 802
+		 * devices, according to RFC 2625) devices will accept ARP
+		 * hardware types of either 1 (Ethernet) or 6 (IEEE 802.2).
+		 * This is the case also of FDDI, where the RFC 1390 says that
+		 * FDDI devices should accept ARP hardware of (1) Ethernet,
+		 * however, to be more robust, we'll accept both 1 (Ethernet)
+		 * or 6 (IEEE 802.2)
+		 */
+		if ((arp->ar_hrd != htons(ARPHRD_ETHER) &&
+		     arp->ar_hrd != htons(ARPHRD_IEEE802)) ||
+		    arp->ar_pro != htons(ETH_P_IP))
+			goto out;
+		break;
+	case ARPHRD_AX25:
+		if (arp->ar_pro != htons(AX25_P_IP) ||
+		    arp->ar_hrd != htons(ARPHRD_AX25))
+			goto out;
+		break;
+	case ARPHRD_NETROM:
+		if (arp->ar_pro != htons(AX25_P_IP) ||
+		    arp->ar_hrd != htons(ARPHRD_NETROM))
+			goto out;
+		break;
+	}
+
+	/* Understand only these message types */
+
+	if (arp->ar_op != htons(ARPOP_REPLY) &&
+	    arp->ar_op != htons(ARPOP_REQUEST))
+		goto out;
+
+/*
+ *	Extract fields
+ */
+	arp_ptr= (unsigned char *)(arp+1);
+	sha	= arp_ptr;
+	arp_ptr += dev->addr_len;
+	memcpy(&sip, arp_ptr, 4);
+	arp_ptr += 4;
+	arp_ptr += dev->addr_len;
+	memcpy(&tip, arp_ptr, 4);
+/*
+ *	Check for bad requests for 127.x.x.x and requests for multicast
+ *	addresses.  If this is one such, delete it.
+ */
+	if (ipv4_is_loopback(tip) || ipv4_is_multicast(tip))
+		goto out;
+
+/*
+ *     Special case: We must set Frame Relay source Q.922 address
+ */
+	if (dev_type == ARPHRD_DLCI)
+		sha = dev->broadcast;
+
+/*
+ *  Process entry.  The idea here is we want to send a reply if it is a
+ *  request for us or if it is a request for someone else that we hold
+ *  a proxy for.  We want to add an entry to our cache if it is a reply
+ *  to us or if it is a request for our address.
+ *  (The assumption for this last is that if someone is requesting our
+ *  address, they are probably intending to talk to us, so it saves time
+ *  if we cache their address.  Their address is also probably not in
+ *  our cache, since ours is not in their cache.)
+ *
+ *  Putting this another way, we only care about replies if they are to
+ *  us, in which case we add them to the cache.  For requests, we care
+ *  about those for us and those for our proxies.  We reply to both,
+ *  and in the case of requests for us we add the requester to the arp
+ *  cache.
+ */
+
+	/* Special case: IPv4 duplicate address detection packet (RFC2131) */
+	if (sip == 0) {
+		if (arp->ar_op == htons(ARPOP_REQUEST) &&
+		    inet_addr_type(net, tip) == RTN_LOCAL &&
+		    !arp_ignore(in_dev, sip, tip))
+			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
+				 dev->dev_addr, sha);
+		goto out;
+	}
+
+	if (arp->ar_op == htons(ARPOP_REQUEST) &&
+	    ip_route_input(skb, tip, sip, 0, dev) == 0) {
+
+		rt = skb->rtable;
+		addr_type = rt->rt_type;
+
+		if (addr_type == RTN_LOCAL) {
+			n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
+			if (n) {
+				int dont_send = 0;
+
+				if (!dont_send)
+					dont_send |= arp_ignore(in_dev,sip,tip);
+				if (!dont_send && IN_DEV_ARPFILTER(in_dev))
+					dont_send |= arp_filter(sip,tip,dev);
+				if (!dont_send)
+					arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
+
+				neigh_release(n);
+			}
+			goto out;
+		} else if (IN_DEV_FORWARD(in_dev)) {
+			    if (addr_type == RTN_UNICAST  && rt->u.dst.dev != dev &&
+			     (arp_fwd_proxy(in_dev, rt) || pneigh_lookup(&arp_tbl, net, &tip, dev, 0))) {
+				n = neigh_event_ns(&arp_tbl, sha, &sip, dev);
+				if (n)
+					neigh_release(n);
+
+				if (NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED ||
+				    skb->pkt_type == PACKET_HOST ||
+				    in_dev->arp_parms->proxy_delay == 0) {
+					arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
+				} else {
+					pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
+					in_dev_put(in_dev);
+					return 0;
+				}
+				goto out;
+			}
+		}
+	}
+
+	/* Update our ARP tables */
+
+	n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
+
+	if (IPV4_DEVCONF_ALL(dev_net(dev), ARP_ACCEPT)) {
+		/* Unsolicited ARP is not accepted by default.
+		   It is possible, that this option should be enabled for some
+		   devices (strip is candidate)
+		 */
+		if (n == NULL &&
+		    arp->ar_op == htons(ARPOP_REPLY) &&
+		    inet_addr_type(net, sip) == RTN_UNICAST)
+			n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
+	}
+
+	if (n) {
+		int state = NUD_REACHABLE;
+		int override;
+
+		/* If several different ARP replies follows back-to-back,
+		   use the FIRST one. It is possible, if several proxy
+		   agents are active. Taking the first reply prevents
+		   arp trashing and chooses the fastest router.
+		 */
+		override = time_after(jiffies, n->updated + n->parms->locktime);
+
+		/* Broadcast replies and request packets
+		   do not assert neighbour reachability.
+		 */
+		if (arp->ar_op != htons(ARPOP_REPLY) ||
+		    skb->pkt_type != PACKET_HOST)
+			state = NUD_STALE;
+		neigh_update(n, sha, state, override ? NEIGH_UPDATE_F_OVERRIDE : 0);
+		neigh_release(n);
+	}
+
+out:
+	if (in_dev)
+		in_dev_put(in_dev);
+	kfree_skb(skb);
+	return 0;
+}
+
+static void parp_redo(struct sk_buff *skb)
+{
+	arp_process(skb);
+}
+
+
+/*
+ *	Receive an arp request from the device layer.
+ */
+
+static int arp_rcv(struct sk_buff *skb, struct net_device *dev,
+		   struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct arphdr *arp;
+
+	/* ARP header, plus 2 device addresses, plus 2 IP addresses.  */
+	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
+		goto freeskb;
+
+	arp = arp_hdr(skb);
+	if (arp->ar_hln != dev->addr_len ||
+	    dev->flags & IFF_NOARP ||
+	    skb->pkt_type == PACKET_OTHERHOST ||
+	    skb->pkt_type == PACKET_LOOPBACK ||
+	    arp->ar_pln != 4)
+		goto freeskb;
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
+		goto out_of_mem;
+
+	memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
+
+	return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process);
+
+freeskb:
+	kfree_skb(skb);
+out_of_mem:
+	return 0;
+}
+
+/*
+ *	User level interface (ioctl)
+ */
+
+/*
+ *	Set (create) an ARP cache entry.
+ */
+
+static int arp_req_set_proxy(struct net *net, struct net_device *dev, int on)
+{
+	if (dev == NULL) {
+		IPV4_DEVCONF_ALL(net, PROXY_ARP) = on;
+		return 0;
+	}
+	if (__in_dev_get_rtnl(dev)) {
+		IN_DEV_CONF_SET(__in_dev_get_rtnl(dev), PROXY_ARP, on);
+		return 0;
+	}
+	return -ENXIO;
+}
+
+static int arp_req_set_public(struct net *net, struct arpreq *r,
+		struct net_device *dev)
+{
+	__be32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
+	__be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
+
+	if (mask && mask != htonl(0xFFFFFFFF))
+		return -EINVAL;
+	if (!dev && (r->arp_flags & ATF_COM)) {
+		dev = dev_getbyhwaddr(net, r->arp_ha.sa_family,
+				r->arp_ha.sa_data);
+		if (!dev)
+			return -ENODEV;
+	}
+	if (mask) {
+		if (pneigh_lookup(&arp_tbl, net, &ip, dev, 1) == NULL)
+			return -ENOBUFS;
+		return 0;
+	}
+
+	return arp_req_set_proxy(net, dev, 1);
+}
+
+static int arp_req_set(struct net *net, struct arpreq *r,
+		struct net_device * dev)
+{
+	__be32 ip;
+	struct neighbour *neigh;
+	int err;
+
+	if (r->arp_flags & ATF_PUBL)
+		return arp_req_set_public(net, r, dev);
+
+	ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
+	if (r->arp_flags & ATF_PERM)
+		r->arp_flags |= ATF_COM;
+	if (dev == NULL) {
+		struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
+							 .tos = RTO_ONLINK } } };
+		struct rtable * rt;
+		if ((err = ip_route_output_key(net, &rt, &fl)) != 0)
+			return err;
+		dev = rt->u.dst.dev;
+		ip_rt_put(rt);
+		if (!dev)
+			return -EINVAL;
+	}
+	switch (dev->type) {
+#ifdef CONFIG_FDDI
+	case ARPHRD_FDDI:
+		/*
+		 * According to RFC 1390, FDDI devices should accept ARP
+		 * hardware types of 1 (Ethernet).  However, to be more
+		 * robust, we'll accept hardware types of either 1 (Ethernet)
+		 * or 6 (IEEE 802.2).
+		 */
+		if (r->arp_ha.sa_family != ARPHRD_FDDI &&
+		    r->arp_ha.sa_family != ARPHRD_ETHER &&
+		    r->arp_ha.sa_family != ARPHRD_IEEE802)
+			return -EINVAL;
+		break;
+#endif
+	default:
+		if (r->arp_ha.sa_family != dev->type)
+			return -EINVAL;
+		break;
+	}
+
+	neigh = __neigh_lookup_errno(&arp_tbl, &ip, dev);
+	err = PTR_ERR(neigh);
+	if (!IS_ERR(neigh)) {
+		unsigned state = NUD_STALE;
+		if (r->arp_flags & ATF_PERM)
+			state = NUD_PERMANENT;
+		err = neigh_update(neigh, (r->arp_flags&ATF_COM) ?
+				   r->arp_ha.sa_data : NULL, state,
+				   NEIGH_UPDATE_F_OVERRIDE|
+				   NEIGH_UPDATE_F_ADMIN);
+		neigh_release(neigh);
+	}
+	return err;
+}
+
+static unsigned arp_state_to_flags(struct neighbour *neigh)
+{
+	unsigned flags = 0;
+	if (neigh->nud_state&NUD_PERMANENT)
+		flags = ATF_PERM|ATF_COM;
+	else if (neigh->nud_state&NUD_VALID)
+		flags = ATF_COM;
+	return flags;
+}
+
+/*
+ *	Get an ARP cache entry.
+ */
+
+static int arp_req_get(struct arpreq *r, struct net_device *dev)
+{
+	__be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
+	struct neighbour *neigh;
+	int err = -ENXIO;
+
+	neigh = neigh_lookup(&arp_tbl, &ip, dev);
+	if (neigh) {
+		read_lock_bh(&neigh->lock);
+		memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len);
+		r->arp_flags = arp_state_to_flags(neigh);
+		read_unlock_bh(&neigh->lock);
+		r->arp_ha.sa_family = dev->type;
+		strlcpy(r->arp_dev, dev->name, sizeof(r->arp_dev));
+		neigh_release(neigh);
+		err = 0;
+	}
+	return err;
+}
+
+static int arp_req_delete_public(struct net *net, struct arpreq *r,
+		struct net_device *dev)
+{
+	__be32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr;
+	__be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
+
+	if (mask == htonl(0xFFFFFFFF))
+		return pneigh_delete(&arp_tbl, net, &ip, dev);
+
+	if (mask)
+		return -EINVAL;
+
+	return arp_req_set_proxy(net, dev, 0);
+}
+
+static int arp_req_delete(struct net *net, struct arpreq *r,
+		struct net_device * dev)
+{
+	int err;
+	__be32 ip;
+	struct neighbour *neigh;
+
+	if (r->arp_flags & ATF_PUBL)
+		return arp_req_delete_public(net, r, dev);
+
+	ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr;
+	if (dev == NULL) {
+		struct flowi fl = { .nl_u = { .ip4_u = { .daddr = ip,
+							 .tos = RTO_ONLINK } } };
+		struct rtable * rt;
+		if ((err = ip_route_output_key(net, &rt, &fl)) != 0)
+			return err;
+		dev = rt->u.dst.dev;
+		ip_rt_put(rt);
+		if (!dev)
+			return -EINVAL;
+	}
+	err = -ENXIO;
+	neigh = neigh_lookup(&arp_tbl, &ip, dev);
+	if (neigh) {
+		if (neigh->nud_state&~NUD_NOARP)
+			err = neigh_update(neigh, NULL, NUD_FAILED,
+					   NEIGH_UPDATE_F_OVERRIDE|
+					   NEIGH_UPDATE_F_ADMIN);
+		neigh_release(neigh);
+	}
+	return err;
+}
+
+/*
+ *	Handle an ARP layer I/O control request.
+ */
+
+int arp_ioctl(struct net *net, unsigned int cmd, void __user *arg)
+{
+	int err;
+	struct arpreq r;
+	struct net_device *dev = NULL;
+
+	switch (cmd) {
+		case SIOCDARP:
+		case SIOCSARP:
+			if (!capable(CAP_NET_ADMIN))
+				return -EPERM;
+		case SIOCGARP:
+			err = copy_from_user(&r, arg, sizeof(struct arpreq));
+			if (err)
+				return -EFAULT;
+			break;
+		default:
+			return -EINVAL;
+	}
+
+	if (r.arp_pa.sa_family != AF_INET)
+		return -EPFNOSUPPORT;
+
+	if (!(r.arp_flags & ATF_PUBL) &&
+	    (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB)))
+		return -EINVAL;
+	if (!(r.arp_flags & ATF_NETMASK))
+		((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr =
+							   htonl(0xFFFFFFFFUL);
+	rtnl_lock();
+	if (r.arp_dev[0]) {
+		err = -ENODEV;
+		if ((dev = __dev_get_by_name(net, r.arp_dev)) == NULL)
+			goto out;
+
+		/* Mmmm... It is wrong... ARPHRD_NETROM==0 */
+		if (!r.arp_ha.sa_family)
+			r.arp_ha.sa_family = dev->type;
+		err = -EINVAL;
+		if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type)
+			goto out;
+	} else if (cmd == SIOCGARP) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	switch (cmd) {
+	case SIOCDARP:
+		err = arp_req_delete(net, &r, dev);
+		break;
+	case SIOCSARP:
+		err = arp_req_set(net, &r, dev);
+		break;
+	case SIOCGARP:
+		err = arp_req_get(&r, dev);
+		if (!err && copy_to_user(arg, &r, sizeof(r)))
+			err = -EFAULT;
+		break;
+	}
+out:
+	rtnl_unlock();
+	return err;
+}
+
+static int arp_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+
+	switch (event) {
+	case NETDEV_CHANGEADDR:
+		neigh_changeaddr(&arp_tbl, dev);
+		rt_cache_flush(dev_net(dev), 0);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block arp_netdev_notifier = {
+	.notifier_call = arp_netdev_event,
+};
+
+/* Note, that it is not on notifier chain.
+   It is necessary, that this routine was called after route cache will be
+   flushed.
+ */
+void arp_ifdown(struct net_device *dev)
+{
+	neigh_ifdown(&arp_tbl, dev);
+}
+
+
+/*
+ *	Called once on startup.
+ */
+
+static struct packet_type arp_packet_type = {
+	.type =	__constant_htons(ETH_P_ARP),
+	.func =	arp_rcv,
+};
+
+static int arp_proc_init(void);
+
+void __init arp_init(void)
+{
+	neigh_table_init(&arp_tbl);
+
+	dev_add_pack(&arp_packet_type);
+	arp_proc_init();
+#ifdef CONFIG_SYSCTL
+	neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4,
+			      NET_IPV4_NEIGH, "ipv4", NULL, NULL);
+#endif
+	register_netdevice_notifier(&arp_netdev_notifier);
+}
+
+#ifdef CONFIG_PROC_FS
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+
+/* ------------------------------------------------------------------------ */
+/*
+ *	ax25 -> ASCII conversion
+ */
+static char *ax2asc2(ax25_address *a, char *buf)
+{
+	char c, *s;
+	int n;
+
+	for (n = 0, s = buf; n < 6; n++) {
+		c = (a->ax25_call[n] >> 1) & 0x7F;
+
+		if (c != ' ') *s++ = c;
+	}
+
+	*s++ = '-';
+
+	if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
+		*s++ = '1';
+		n -= 10;
+	}
+
+	*s++ = n + '0';
+	*s++ = '\0';
+
+	if (*buf == '\0' || *buf == '-')
+	   return "*";
+
+	return buf;
+
+}
+#endif /* CONFIG_AX25 */
+
+#define HBUFFERLEN 30
+
+static void arp_format_neigh_entry(struct seq_file *seq,
+				   struct neighbour *n)
+{
+	char hbuffer[HBUFFERLEN];
+	int k, j;
+	char tbuf[16];
+	struct net_device *dev = n->dev;
+	int hatype = dev->type;
+
+	read_lock(&n->lock);
+	/* Convert hardware address to XX:XX:XX:XX ... form. */
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+	if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM)
+		ax2asc2((ax25_address *)n->ha, hbuffer);
+	else {
+#endif
+	for (k = 0, j = 0; k < HBUFFERLEN - 3 && j < dev->addr_len; j++) {
+		hbuffer[k++] = hex_asc_hi(n->ha[j]);
+		hbuffer[k++] = hex_asc_lo(n->ha[j]);
+		hbuffer[k++] = ':';
+	}
+	hbuffer[--k] = 0;
+#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
+	}
+#endif
+	sprintf(tbuf, NIPQUAD_FMT, NIPQUAD(*(u32*)n->primary_key));
+	seq_printf(seq, "%-16s 0x%-10x0x%-10x%s     *        %s\n",
+		   tbuf, hatype, arp_state_to_flags(n), hbuffer, dev->name);
+	read_unlock(&n->lock);
+}
+
+static void arp_format_pneigh_entry(struct seq_file *seq,
+				    struct pneigh_entry *n)
+{
+	struct net_device *dev = n->dev;
+	int hatype = dev ? dev->type : 0;
+	char tbuf[16];
+
+	sprintf(tbuf, NIPQUAD_FMT, NIPQUAD(*(u32*)n->key));
+	seq_printf(seq, "%-16s 0x%-10x0x%-10x%s     *        %s\n",
+		   tbuf, hatype, ATF_PUBL | ATF_PERM, "00:00:00:00:00:00",
+		   dev ? dev->name : "*");
+}
+
+static int arp_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq, "IP address       HW type     Flags       "
+			      "HW address            Mask     Device\n");
+	} else {
+		struct neigh_seq_state *state = seq->private;
+
+		if (state->flags & NEIGH_SEQ_IS_PNEIGH)
+			arp_format_pneigh_entry(seq, v);
+		else
+			arp_format_neigh_entry(seq, v);
+	}
+
+	return 0;
+}
+
+static void *arp_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	/* Don't want to confuse "arp -a" w/ magic entries,
+	 * so we tell the generic iterator to skip NUD_NOARP.
+	 */
+	return neigh_seq_start(seq, pos, &arp_tbl, NEIGH_SEQ_SKIP_NOARP);
+}
+
+/* ------------------------------------------------------------------------ */
+
+static const struct seq_operations arp_seq_ops = {
+	.start  = arp_seq_start,
+	.next   = neigh_seq_next,
+	.stop   = neigh_seq_stop,
+	.show   = arp_seq_show,
+};
+
+static int arp_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &arp_seq_ops,
+			    sizeof(struct neigh_seq_state));
+}
+
+static const struct file_operations arp_seq_fops = {
+	.owner		= THIS_MODULE,
+	.open           = arp_seq_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release	= seq_release_net,
+};
+
+
+static int __net_init arp_net_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "arp", S_IRUGO, &arp_seq_fops))
+		return -ENOMEM;
+	return 0;
+}
+
+static void __net_exit arp_net_exit(struct net *net)
+{
+	proc_net_remove(net, "arp");
+}
+
+static struct pernet_operations arp_net_ops = {
+	.init = arp_net_init,
+	.exit = arp_net_exit,
+};
+
+static int __init arp_proc_init(void)
+{
+	return register_pernet_subsys(&arp_net_ops);
+}
+
+#else /* CONFIG_PROC_FS */
+
+static int __init arp_proc_init(void)
+{
+	return 0;
+}
+
+#endif /* CONFIG_PROC_FS */
+
+EXPORT_SYMBOL(arp_broken_ops);
+EXPORT_SYMBOL(arp_find);
+EXPORT_SYMBOL(arp_create);
+EXPORT_SYMBOL(arp_xmit);
+EXPORT_SYMBOL(arp_send);
+EXPORT_SYMBOL(arp_tbl);
+
+#if defined(CONFIG_ATM_CLIP) || defined(CONFIG_ATM_CLIP_MODULE)
+EXPORT_SYMBOL(clip_tbl_hook);
+#endif
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
new file mode 100644
index 0000000..2e78f6b
--- /dev/null
+++ b/net/ipv4/cipso_ipv4.c
@@ -0,0 +1,2202 @@
+/*
+ * CIPSO - Commercial IP Security Option
+ *
+ * This is an implementation of the CIPSO 2.2 protocol as specified in
+ * draft-ietf-cipso-ipsecurity-01.txt with additional tag types as found in
+ * FIPS-188, copies of both documents can be found in the Documentation
+ * directory.  While CIPSO never became a full IETF RFC standard many vendors
+ * have chosen to adopt the protocol and over the years it has become a
+ * de-facto standard for labeled networking.
+ *
+ * Author: Paul Moore <paul.moore@hp.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006, 2008
+ *
+ * This program is free software;  you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY;  without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program;  if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/rcupdate.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/jhash.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/netlabel.h>
+#include <net/cipso_ipv4.h>
+#include <asm/atomic.h>
+#include <asm/bug.h>
+#include <asm/unaligned.h>
+
+/* List of available DOI definitions */
+/* XXX - This currently assumes a minimal number of different DOIs in use,
+ * if in practice there are a lot of different DOIs this list should
+ * probably be turned into a hash table or something similar so we
+ * can do quick lookups. */
+static DEFINE_SPINLOCK(cipso_v4_doi_list_lock);
+static LIST_HEAD(cipso_v4_doi_list);
+
+/* Label mapping cache */
+int cipso_v4_cache_enabled = 1;
+int cipso_v4_cache_bucketsize = 10;
+#define CIPSO_V4_CACHE_BUCKETBITS     7
+#define CIPSO_V4_CACHE_BUCKETS        (1 << CIPSO_V4_CACHE_BUCKETBITS)
+#define CIPSO_V4_CACHE_REORDERLIMIT   10
+struct cipso_v4_map_cache_bkt {
+	spinlock_t lock;
+	u32 size;
+	struct list_head list;
+};
+struct cipso_v4_map_cache_entry {
+	u32 hash;
+	unsigned char *key;
+	size_t key_len;
+
+	struct netlbl_lsm_cache *lsm_data;
+
+	u32 activity;
+	struct list_head list;
+};
+static struct cipso_v4_map_cache_bkt *cipso_v4_cache = NULL;
+
+/* Restricted bitmap (tag #1) flags */
+int cipso_v4_rbm_optfmt = 0;
+int cipso_v4_rbm_strictvalid = 1;
+
+/*
+ * Protocol Constants
+ */
+
+/* Maximum size of the CIPSO IP option, derived from the fact that the maximum
+ * IPv4 header size is 60 bytes and the base IPv4 header is 20 bytes long. */
+#define CIPSO_V4_OPT_LEN_MAX          40
+
+/* Length of the base CIPSO option, this includes the option type (1 byte), the
+ * option length (1 byte), and the DOI (4 bytes). */
+#define CIPSO_V4_HDR_LEN              6
+
+/* Base length of the restrictive category bitmap tag (tag #1). */
+#define CIPSO_V4_TAG_RBM_BLEN         4
+
+/* Base length of the enumerated category tag (tag #2). */
+#define CIPSO_V4_TAG_ENUM_BLEN        4
+
+/* Base length of the ranged categories bitmap tag (tag #5). */
+#define CIPSO_V4_TAG_RNG_BLEN         4
+/* The maximum number of category ranges permitted in the ranged category tag
+ * (tag #5).  You may note that the IETF draft states that the maximum number
+ * of category ranges is 7, but if the low end of the last category range is
+ * zero then it is possibile to fit 8 category ranges because the zero should
+ * be omitted. */
+#define CIPSO_V4_TAG_RNG_CAT_MAX      8
+
+/* Base length of the local tag (non-standard tag).
+ *  Tag definition (may change between kernel versions)
+ *
+ * 0          8          16         24         32
+ * +----------+----------+----------+----------+
+ * | 10000000 | 00000110 | 32-bit secid value  |
+ * +----------+----------+----------+----------+
+ * | in (host byte order)|
+ * +----------+----------+
+ *
+ */
+#define CIPSO_V4_TAG_LOC_BLEN         6
+
+/*
+ * Helper Functions
+ */
+
+/**
+ * cipso_v4_bitmap_walk - Walk a bitmap looking for a bit
+ * @bitmap: the bitmap
+ * @bitmap_len: length in bits
+ * @offset: starting offset
+ * @state: if non-zero, look for a set (1) bit else look for a cleared (0) bit
+ *
+ * Description:
+ * Starting at @offset, walk the bitmap from left to right until either the
+ * desired bit is found or we reach the end.  Return the bit offset, -1 if
+ * not found, or -2 if error.
+ */
+static int cipso_v4_bitmap_walk(const unsigned char *bitmap,
+				u32 bitmap_len,
+				u32 offset,
+				u8 state)
+{
+	u32 bit_spot;
+	u32 byte_offset;
+	unsigned char bitmask;
+	unsigned char byte;
+
+	/* gcc always rounds to zero when doing integer division */
+	byte_offset = offset / 8;
+	byte = bitmap[byte_offset];
+	bit_spot = offset;
+	bitmask = 0x80 >> (offset % 8);
+
+	while (bit_spot < bitmap_len) {
+		if ((state && (byte & bitmask) == bitmask) ||
+		    (state == 0 && (byte & bitmask) == 0))
+			return bit_spot;
+
+		bit_spot++;
+		bitmask >>= 1;
+		if (bitmask == 0) {
+			byte = bitmap[++byte_offset];
+			bitmask = 0x80;
+		}
+	}
+
+	return -1;
+}
+
+/**
+ * cipso_v4_bitmap_setbit - Sets a single bit in a bitmap
+ * @bitmap: the bitmap
+ * @bit: the bit
+ * @state: if non-zero, set the bit (1) else clear the bit (0)
+ *
+ * Description:
+ * Set a single bit in the bitmask.  Returns zero on success, negative values
+ * on error.
+ */
+static void cipso_v4_bitmap_setbit(unsigned char *bitmap,
+				   u32 bit,
+				   u8 state)
+{
+	u32 byte_spot;
+	u8 bitmask;
+
+	/* gcc always rounds to zero when doing integer division */
+	byte_spot = bit / 8;
+	bitmask = 0x80 >> (bit % 8);
+	if (state)
+		bitmap[byte_spot] |= bitmask;
+	else
+		bitmap[byte_spot] &= ~bitmask;
+}
+
+/**
+ * cipso_v4_cache_entry_free - Frees a cache entry
+ * @entry: the entry to free
+ *
+ * Description:
+ * This function frees the memory associated with a cache entry including the
+ * LSM cache data if there are no longer any users, i.e. reference count == 0.
+ *
+ */
+static void cipso_v4_cache_entry_free(struct cipso_v4_map_cache_entry *entry)
+{
+	if (entry->lsm_data)
+		netlbl_secattr_cache_free(entry->lsm_data);
+	kfree(entry->key);
+	kfree(entry);
+}
+
+/**
+ * cipso_v4_map_cache_hash - Hashing function for the CIPSO cache
+ * @key: the hash key
+ * @key_len: the length of the key in bytes
+ *
+ * Description:
+ * The CIPSO tag hashing function.  Returns a 32-bit hash value.
+ *
+ */
+static u32 cipso_v4_map_cache_hash(const unsigned char *key, u32 key_len)
+{
+	return jhash(key, key_len, 0);
+}
+
+/*
+ * Label Mapping Cache Functions
+ */
+
+/**
+ * cipso_v4_cache_init - Initialize the CIPSO cache
+ *
+ * Description:
+ * Initializes the CIPSO label mapping cache, this function should be called
+ * before any of the other functions defined in this file.  Returns zero on
+ * success, negative values on error.
+ *
+ */
+static int cipso_v4_cache_init(void)
+{
+	u32 iter;
+
+	cipso_v4_cache = kcalloc(CIPSO_V4_CACHE_BUCKETS,
+				 sizeof(struct cipso_v4_map_cache_bkt),
+				 GFP_KERNEL);
+	if (cipso_v4_cache == NULL)
+		return -ENOMEM;
+
+	for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
+		spin_lock_init(&cipso_v4_cache[iter].lock);
+		cipso_v4_cache[iter].size = 0;
+		INIT_LIST_HEAD(&cipso_v4_cache[iter].list);
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_cache_invalidate - Invalidates the current CIPSO cache
+ *
+ * Description:
+ * Invalidates and frees any entries in the CIPSO cache.  Returns zero on
+ * success and negative values on failure.
+ *
+ */
+void cipso_v4_cache_invalidate(void)
+{
+	struct cipso_v4_map_cache_entry *entry, *tmp_entry;
+	u32 iter;
+
+	for (iter = 0; iter < CIPSO_V4_CACHE_BUCKETS; iter++) {
+		spin_lock_bh(&cipso_v4_cache[iter].lock);
+		list_for_each_entry_safe(entry,
+					 tmp_entry,
+					 &cipso_v4_cache[iter].list, list) {
+			list_del(&entry->list);
+			cipso_v4_cache_entry_free(entry);
+		}
+		cipso_v4_cache[iter].size = 0;
+		spin_unlock_bh(&cipso_v4_cache[iter].lock);
+	}
+
+	return;
+}
+
+/**
+ * cipso_v4_cache_check - Check the CIPSO cache for a label mapping
+ * @key: the buffer to check
+ * @key_len: buffer length in bytes
+ * @secattr: the security attribute struct to use
+ *
+ * Description:
+ * This function checks the cache to see if a label mapping already exists for
+ * the given key.  If there is a match then the cache is adjusted and the
+ * @secattr struct is populated with the correct LSM security attributes.  The
+ * cache is adjusted in the following manner if the entry is not already the
+ * first in the cache bucket:
+ *
+ *  1. The cache entry's activity counter is incremented
+ *  2. The previous (higher ranking) entry's activity counter is decremented
+ *  3. If the difference between the two activity counters is geater than
+ *     CIPSO_V4_CACHE_REORDERLIMIT the two entries are swapped
+ *
+ * Returns zero on success, -ENOENT for a cache miss, and other negative values
+ * on error.
+ *
+ */
+static int cipso_v4_cache_check(const unsigned char *key,
+				u32 key_len,
+				struct netlbl_lsm_secattr *secattr)
+{
+	u32 bkt;
+	struct cipso_v4_map_cache_entry *entry;
+	struct cipso_v4_map_cache_entry *prev_entry = NULL;
+	u32 hash;
+
+	if (!cipso_v4_cache_enabled)
+		return -ENOENT;
+
+	hash = cipso_v4_map_cache_hash(key, key_len);
+	bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
+	spin_lock_bh(&cipso_v4_cache[bkt].lock);
+	list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
+		if (entry->hash == hash &&
+		    entry->key_len == key_len &&
+		    memcmp(entry->key, key, key_len) == 0) {
+			entry->activity += 1;
+			atomic_inc(&entry->lsm_data->refcount);
+			secattr->cache = entry->lsm_data;
+			secattr->flags |= NETLBL_SECATTR_CACHE;
+			secattr->type = NETLBL_NLTYPE_CIPSOV4;
+			if (prev_entry == NULL) {
+				spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+				return 0;
+			}
+
+			if (prev_entry->activity > 0)
+				prev_entry->activity -= 1;
+			if (entry->activity > prev_entry->activity &&
+			    entry->activity - prev_entry->activity >
+			    CIPSO_V4_CACHE_REORDERLIMIT) {
+				__list_del(entry->list.prev, entry->list.next);
+				__list_add(&entry->list,
+					   prev_entry->list.prev,
+					   &prev_entry->list);
+			}
+
+			spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+			return 0;
+		}
+		prev_entry = entry;
+	}
+	spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+
+	return -ENOENT;
+}
+
+/**
+ * cipso_v4_cache_add - Add an entry to the CIPSO cache
+ * @skb: the packet
+ * @secattr: the packet's security attributes
+ *
+ * Description:
+ * Add a new entry into the CIPSO label mapping cache.  Add the new entry to
+ * head of the cache bucket's list, if the cache bucket is out of room remove
+ * the last entry in the list first.  It is important to note that there is
+ * currently no checking for duplicate keys.  Returns zero on success,
+ * negative values on failure.
+ *
+ */
+int cipso_v4_cache_add(const struct sk_buff *skb,
+		       const struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val = -EPERM;
+	u32 bkt;
+	struct cipso_v4_map_cache_entry *entry = NULL;
+	struct cipso_v4_map_cache_entry *old_entry = NULL;
+	unsigned char *cipso_ptr;
+	u32 cipso_ptr_len;
+
+	if (!cipso_v4_cache_enabled || cipso_v4_cache_bucketsize <= 0)
+		return 0;
+
+	cipso_ptr = CIPSO_V4_OPTPTR(skb);
+	cipso_ptr_len = cipso_ptr[1];
+
+	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+	if (entry == NULL)
+		return -ENOMEM;
+	entry->key = kmemdup(cipso_ptr, cipso_ptr_len, GFP_ATOMIC);
+	if (entry->key == NULL) {
+		ret_val = -ENOMEM;
+		goto cache_add_failure;
+	}
+	entry->key_len = cipso_ptr_len;
+	entry->hash = cipso_v4_map_cache_hash(cipso_ptr, cipso_ptr_len);
+	atomic_inc(&secattr->cache->refcount);
+	entry->lsm_data = secattr->cache;
+
+	bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
+	spin_lock_bh(&cipso_v4_cache[bkt].lock);
+	if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
+		list_add(&entry->list, &cipso_v4_cache[bkt].list);
+		cipso_v4_cache[bkt].size += 1;
+	} else {
+		old_entry = list_entry(cipso_v4_cache[bkt].list.prev,
+				       struct cipso_v4_map_cache_entry, list);
+		list_del(&old_entry->list);
+		list_add(&entry->list, &cipso_v4_cache[bkt].list);
+		cipso_v4_cache_entry_free(old_entry);
+	}
+	spin_unlock_bh(&cipso_v4_cache[bkt].lock);
+
+	return 0;
+
+cache_add_failure:
+	if (entry)
+		cipso_v4_cache_entry_free(entry);
+	return ret_val;
+}
+
+/*
+ * DOI List Functions
+ */
+
+/**
+ * cipso_v4_doi_search - Searches for a DOI definition
+ * @doi: the DOI to search for
+ *
+ * Description:
+ * Search the DOI definition list for a DOI definition with a DOI value that
+ * matches @doi.  The caller is responsibile for calling rcu_read_[un]lock().
+ * Returns a pointer to the DOI definition on success and NULL on failure.
+ */
+static struct cipso_v4_doi *cipso_v4_doi_search(u32 doi)
+{
+	struct cipso_v4_doi *iter;
+
+	list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
+		if (iter->doi == doi && atomic_read(&iter->refcount))
+			return iter;
+	return NULL;
+}
+
+/**
+ * cipso_v4_doi_add - Add a new DOI to the CIPSO protocol engine
+ * @doi_def: the DOI structure
+ *
+ * Description:
+ * The caller defines a new DOI for use by the CIPSO engine and calls this
+ * function to add it to the list of acceptable domains.  The caller must
+ * ensure that the mapping table specified in @doi_def->map meets all of the
+ * requirements of the mapping type (see cipso_ipv4.h for details).  Returns
+ * zero on success and non-zero on failure.
+ *
+ */
+int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
+{
+	u32 iter;
+
+	if (doi_def == NULL || doi_def->doi == CIPSO_V4_DOI_UNKNOWN)
+		return -EINVAL;
+	for (iter = 0; iter < CIPSO_V4_TAG_MAXCNT; iter++) {
+		switch (doi_def->tags[iter]) {
+		case CIPSO_V4_TAG_RBITMAP:
+			break;
+		case CIPSO_V4_TAG_RANGE:
+			if (doi_def->type != CIPSO_V4_MAP_PASS)
+				return -EINVAL;
+			break;
+		case CIPSO_V4_TAG_INVALID:
+			if (iter == 0)
+				return -EINVAL;
+			break;
+		case CIPSO_V4_TAG_ENUM:
+			if (doi_def->type != CIPSO_V4_MAP_PASS)
+				return -EINVAL;
+			break;
+		case CIPSO_V4_TAG_LOCAL:
+			if (doi_def->type != CIPSO_V4_MAP_LOCAL)
+				return -EINVAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	atomic_set(&doi_def->refcount, 1);
+	INIT_RCU_HEAD(&doi_def->rcu);
+
+	spin_lock(&cipso_v4_doi_list_lock);
+	if (cipso_v4_doi_search(doi_def->doi) != NULL)
+		goto doi_add_failure;
+	list_add_tail_rcu(&doi_def->list, &cipso_v4_doi_list);
+	spin_unlock(&cipso_v4_doi_list_lock);
+
+	return 0;
+
+doi_add_failure:
+	spin_unlock(&cipso_v4_doi_list_lock);
+	return -EEXIST;
+}
+
+/**
+ * cipso_v4_doi_free - Frees a DOI definition
+ * @entry: the entry's RCU field
+ *
+ * Description:
+ * This function frees all of the memory associated with a DOI definition.
+ *
+ */
+void cipso_v4_doi_free(struct cipso_v4_doi *doi_def)
+{
+	if (doi_def == NULL)
+		return;
+
+	switch (doi_def->type) {
+	case CIPSO_V4_MAP_TRANS:
+		kfree(doi_def->map.std->lvl.cipso);
+		kfree(doi_def->map.std->lvl.local);
+		kfree(doi_def->map.std->cat.cipso);
+		kfree(doi_def->map.std->cat.local);
+		break;
+	}
+	kfree(doi_def);
+}
+
+/**
+ * cipso_v4_doi_free_rcu - Frees a DOI definition via the RCU pointer
+ * @entry: the entry's RCU field
+ *
+ * Description:
+ * This function is designed to be used as a callback to the call_rcu()
+ * function so that the memory allocated to the DOI definition can be released
+ * safely.
+ *
+ */
+static void cipso_v4_doi_free_rcu(struct rcu_head *entry)
+{
+	struct cipso_v4_doi *doi_def;
+
+	doi_def = container_of(entry, struct cipso_v4_doi, rcu);
+	cipso_v4_doi_free(doi_def);
+}
+
+/**
+ * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
+ * @doi: the DOI value
+ * @audit_secid: the LSM secid to use in the audit message
+ *
+ * Description:
+ * Removes a DOI definition from the CIPSO engine.  The NetLabel routines will
+ * be called to release their own LSM domain mappings as well as our own
+ * domain list.  Returns zero on success and negative values on failure.
+ *
+ */
+int cipso_v4_doi_remove(u32 doi, struct netlbl_audit *audit_info)
+{
+	struct cipso_v4_doi *doi_def;
+
+	spin_lock(&cipso_v4_doi_list_lock);
+	doi_def = cipso_v4_doi_search(doi);
+	if (doi_def == NULL) {
+		spin_unlock(&cipso_v4_doi_list_lock);
+		return -ENOENT;
+	}
+	if (!atomic_dec_and_test(&doi_def->refcount)) {
+		spin_unlock(&cipso_v4_doi_list_lock);
+		return -EBUSY;
+	}
+	list_del_rcu(&doi_def->list);
+	spin_unlock(&cipso_v4_doi_list_lock);
+
+	cipso_v4_cache_invalidate();
+	call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
+
+	return 0;
+}
+
+/**
+ * cipso_v4_doi_getdef - Returns a reference to a valid DOI definition
+ * @doi: the DOI value
+ *
+ * Description:
+ * Searches for a valid DOI definition and if one is found it is returned to
+ * the caller.  Otherwise NULL is returned.  The caller must ensure that
+ * rcu_read_lock() is held while accessing the returned definition and the DOI
+ * definition reference count is decremented when the caller is done.
+ *
+ */
+struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
+{
+	struct cipso_v4_doi *doi_def;
+
+	rcu_read_lock();
+	doi_def = cipso_v4_doi_search(doi);
+	if (doi_def == NULL)
+		goto doi_getdef_return;
+	if (!atomic_inc_not_zero(&doi_def->refcount))
+		doi_def = NULL;
+
+doi_getdef_return:
+	rcu_read_unlock();
+	return doi_def;
+}
+
+/**
+ * cipso_v4_doi_putdef - Releases a reference for the given DOI definition
+ * @doi_def: the DOI definition
+ *
+ * Description:
+ * Releases a DOI definition reference obtained from cipso_v4_doi_getdef().
+ *
+ */
+void cipso_v4_doi_putdef(struct cipso_v4_doi *doi_def)
+{
+	if (doi_def == NULL)
+		return;
+
+	if (!atomic_dec_and_test(&doi_def->refcount))
+		return;
+	spin_lock(&cipso_v4_doi_list_lock);
+	list_del_rcu(&doi_def->list);
+	spin_unlock(&cipso_v4_doi_list_lock);
+
+	cipso_v4_cache_invalidate();
+	call_rcu(&doi_def->rcu, cipso_v4_doi_free_rcu);
+}
+
+/**
+ * cipso_v4_doi_walk - Iterate through the DOI definitions
+ * @skip_cnt: skip past this number of DOI definitions, updated
+ * @callback: callback for each DOI definition
+ * @cb_arg: argument for the callback function
+ *
+ * Description:
+ * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
+ * For each entry call @callback, if @callback returns a negative value stop
+ * 'walking' through the list and return.  Updates the value in @skip_cnt upon
+ * return.  Returns zero on success, negative values on failure.
+ *
+ */
+int cipso_v4_doi_walk(u32 *skip_cnt,
+		     int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
+		     void *cb_arg)
+{
+	int ret_val = -ENOENT;
+	u32 doi_cnt = 0;
+	struct cipso_v4_doi *iter_doi;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
+		if (atomic_read(&iter_doi->refcount) > 0) {
+			if (doi_cnt++ < *skip_cnt)
+				continue;
+			ret_val = callback(iter_doi, cb_arg);
+			if (ret_val < 0) {
+				doi_cnt--;
+				goto doi_walk_return;
+			}
+		}
+
+doi_walk_return:
+	rcu_read_unlock();
+	*skip_cnt = doi_cnt;
+	return ret_val;
+}
+
+/*
+ * Label Mapping Functions
+ */
+
+/**
+ * cipso_v4_map_lvl_valid - Checks to see if the given level is understood
+ * @doi_def: the DOI definition
+ * @level: the level to check
+ *
+ * Description:
+ * Checks the given level against the given DOI definition and returns a
+ * negative value if the level does not have a valid mapping and a zero value
+ * if the level is defined by the DOI.
+ *
+ */
+static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
+{
+	switch (doi_def->type) {
+	case CIPSO_V4_MAP_PASS:
+		return 0;
+	case CIPSO_V4_MAP_TRANS:
+		if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
+			return 0;
+		break;
+	}
+
+	return -EFAULT;
+}
+
+/**
+ * cipso_v4_map_lvl_hton - Perform a level mapping from the host to the network
+ * @doi_def: the DOI definition
+ * @host_lvl: the host MLS level
+ * @net_lvl: the network/CIPSO MLS level
+ *
+ * Description:
+ * Perform a label mapping to translate a local MLS level to the correct
+ * CIPSO level using the given DOI definition.  Returns zero on success,
+ * negative values otherwise.
+ *
+ */
+static int cipso_v4_map_lvl_hton(const struct cipso_v4_doi *doi_def,
+				 u32 host_lvl,
+				 u32 *net_lvl)
+{
+	switch (doi_def->type) {
+	case CIPSO_V4_MAP_PASS:
+		*net_lvl = host_lvl;
+		return 0;
+	case CIPSO_V4_MAP_TRANS:
+		if (host_lvl < doi_def->map.std->lvl.local_size &&
+		    doi_def->map.std->lvl.local[host_lvl] < CIPSO_V4_INV_LVL) {
+			*net_lvl = doi_def->map.std->lvl.local[host_lvl];
+			return 0;
+		}
+		return -EPERM;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * cipso_v4_map_lvl_ntoh - Perform a level mapping from the network to the host
+ * @doi_def: the DOI definition
+ * @net_lvl: the network/CIPSO MLS level
+ * @host_lvl: the host MLS level
+ *
+ * Description:
+ * Perform a label mapping to translate a CIPSO level to the correct local MLS
+ * level using the given DOI definition.  Returns zero on success, negative
+ * values otherwise.
+ *
+ */
+static int cipso_v4_map_lvl_ntoh(const struct cipso_v4_doi *doi_def,
+				 u32 net_lvl,
+				 u32 *host_lvl)
+{
+	struct cipso_v4_std_map_tbl *map_tbl;
+
+	switch (doi_def->type) {
+	case CIPSO_V4_MAP_PASS:
+		*host_lvl = net_lvl;
+		return 0;
+	case CIPSO_V4_MAP_TRANS:
+		map_tbl = doi_def->map.std;
+		if (net_lvl < map_tbl->lvl.cipso_size &&
+		    map_tbl->lvl.cipso[net_lvl] < CIPSO_V4_INV_LVL) {
+			*host_lvl = doi_def->map.std->lvl.cipso[net_lvl];
+			return 0;
+		}
+		return -EPERM;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * cipso_v4_map_cat_rbm_valid - Checks to see if the category bitmap is valid
+ * @doi_def: the DOI definition
+ * @bitmap: category bitmap
+ * @bitmap_len: bitmap length in bytes
+ *
+ * Description:
+ * Checks the given category bitmap against the given DOI definition and
+ * returns a negative value if any of the categories in the bitmap do not have
+ * a valid mapping and a zero value if all of the categories are valid.
+ *
+ */
+static int cipso_v4_map_cat_rbm_valid(const struct cipso_v4_doi *doi_def,
+				      const unsigned char *bitmap,
+				      u32 bitmap_len)
+{
+	int cat = -1;
+	u32 bitmap_len_bits = bitmap_len * 8;
+	u32 cipso_cat_size;
+	u32 *cipso_array;
+
+	switch (doi_def->type) {
+	case CIPSO_V4_MAP_PASS:
+		return 0;
+	case CIPSO_V4_MAP_TRANS:
+		cipso_cat_size = doi_def->map.std->cat.cipso_size;
+		cipso_array = doi_def->map.std->cat.cipso;
+		for (;;) {
+			cat = cipso_v4_bitmap_walk(bitmap,
+						   bitmap_len_bits,
+						   cat + 1,
+						   1);
+			if (cat < 0)
+				break;
+			if (cat >= cipso_cat_size ||
+			    cipso_array[cat] >= CIPSO_V4_INV_CAT)
+				return -EFAULT;
+		}
+
+		if (cat == -1)
+			return 0;
+		break;
+	}
+
+	return -EFAULT;
+}
+
+/**
+ * cipso_v4_map_cat_rbm_hton - Perform a category mapping from host to network
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @net_cat: the zero'd out category bitmap in network/CIPSO format
+ * @net_cat_len: the length of the CIPSO bitmap in bytes
+ *
+ * Description:
+ * Perform a label mapping to translate a local MLS category bitmap to the
+ * correct CIPSO bitmap using the given DOI definition.  Returns the minimum
+ * size in bytes of the network bitmap on success, negative values otherwise.
+ *
+ */
+static int cipso_v4_map_cat_rbm_hton(const struct cipso_v4_doi *doi_def,
+				     const struct netlbl_lsm_secattr *secattr,
+				     unsigned char *net_cat,
+				     u32 net_cat_len)
+{
+	int host_spot = -1;
+	u32 net_spot = CIPSO_V4_INV_CAT;
+	u32 net_spot_max = 0;
+	u32 net_clen_bits = net_cat_len * 8;
+	u32 host_cat_size = 0;
+	u32 *host_cat_array = NULL;
+
+	if (doi_def->type == CIPSO_V4_MAP_TRANS) {
+		host_cat_size = doi_def->map.std->cat.local_size;
+		host_cat_array = doi_def->map.std->cat.local;
+	}
+
+	for (;;) {
+		host_spot = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
+						       host_spot + 1);
+		if (host_spot < 0)
+			break;
+
+		switch (doi_def->type) {
+		case CIPSO_V4_MAP_PASS:
+			net_spot = host_spot;
+			break;
+		case CIPSO_V4_MAP_TRANS:
+			if (host_spot >= host_cat_size)
+				return -EPERM;
+			net_spot = host_cat_array[host_spot];
+			if (net_spot >= CIPSO_V4_INV_CAT)
+				return -EPERM;
+			break;
+		}
+		if (net_spot >= net_clen_bits)
+			return -ENOSPC;
+		cipso_v4_bitmap_setbit(net_cat, net_spot, 1);
+
+		if (net_spot > net_spot_max)
+			net_spot_max = net_spot;
+	}
+
+	if (++net_spot_max % 8)
+		return net_spot_max / 8 + 1;
+	return net_spot_max / 8;
+}
+
+/**
+ * cipso_v4_map_cat_rbm_ntoh - Perform a category mapping from network to host
+ * @doi_def: the DOI definition
+ * @net_cat: the category bitmap in network/CIPSO format
+ * @net_cat_len: the length of the CIPSO bitmap in bytes
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Perform a label mapping to translate a CIPSO bitmap to the correct local
+ * MLS category bitmap using the given DOI definition.  Returns zero on
+ * success, negative values on failure.
+ *
+ */
+static int cipso_v4_map_cat_rbm_ntoh(const struct cipso_v4_doi *doi_def,
+				     const unsigned char *net_cat,
+				     u32 net_cat_len,
+				     struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	int net_spot = -1;
+	u32 host_spot = CIPSO_V4_INV_CAT;
+	u32 net_clen_bits = net_cat_len * 8;
+	u32 net_cat_size = 0;
+	u32 *net_cat_array = NULL;
+
+	if (doi_def->type == CIPSO_V4_MAP_TRANS) {
+		net_cat_size = doi_def->map.std->cat.cipso_size;
+		net_cat_array = doi_def->map.std->cat.cipso;
+	}
+
+	for (;;) {
+		net_spot = cipso_v4_bitmap_walk(net_cat,
+						net_clen_bits,
+						net_spot + 1,
+						1);
+		if (net_spot < 0) {
+			if (net_spot == -2)
+				return -EFAULT;
+			return 0;
+		}
+
+		switch (doi_def->type) {
+		case CIPSO_V4_MAP_PASS:
+			host_spot = net_spot;
+			break;
+		case CIPSO_V4_MAP_TRANS:
+			if (net_spot >= net_cat_size)
+				return -EPERM;
+			host_spot = net_cat_array[net_spot];
+			if (host_spot >= CIPSO_V4_INV_CAT)
+				return -EPERM;
+			break;
+		}
+		ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
+						       host_spot,
+						       GFP_ATOMIC);
+		if (ret_val != 0)
+			return ret_val;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * cipso_v4_map_cat_enum_valid - Checks to see if the categories are valid
+ * @doi_def: the DOI definition
+ * @enumcat: category list
+ * @enumcat_len: length of the category list in bytes
+ *
+ * Description:
+ * Checks the given categories against the given DOI definition and returns a
+ * negative value if any of the categories do not have a valid mapping and a
+ * zero value if all of the categories are valid.
+ *
+ */
+static int cipso_v4_map_cat_enum_valid(const struct cipso_v4_doi *doi_def,
+				       const unsigned char *enumcat,
+				       u32 enumcat_len)
+{
+	u16 cat;
+	int cat_prev = -1;
+	u32 iter;
+
+	if (doi_def->type != CIPSO_V4_MAP_PASS || enumcat_len & 0x01)
+		return -EFAULT;
+
+	for (iter = 0; iter < enumcat_len; iter += 2) {
+		cat = get_unaligned_be16(&enumcat[iter]);
+		if (cat <= cat_prev)
+			return -EFAULT;
+		cat_prev = cat;
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_map_cat_enum_hton - Perform a category mapping from host to network
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @net_cat: the zero'd out category list in network/CIPSO format
+ * @net_cat_len: the length of the CIPSO category list in bytes
+ *
+ * Description:
+ * Perform a label mapping to translate a local MLS category bitmap to the
+ * correct CIPSO category list using the given DOI definition.   Returns the
+ * size in bytes of the network category bitmap on success, negative values
+ * otherwise.
+ *
+ */
+static int cipso_v4_map_cat_enum_hton(const struct cipso_v4_doi *doi_def,
+				      const struct netlbl_lsm_secattr *secattr,
+				      unsigned char *net_cat,
+				      u32 net_cat_len)
+{
+	int cat = -1;
+	u32 cat_iter = 0;
+
+	for (;;) {
+		cat = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
+						 cat + 1);
+		if (cat < 0)
+			break;
+		if ((cat_iter + 2) > net_cat_len)
+			return -ENOSPC;
+
+		*((__be16 *)&net_cat[cat_iter]) = htons(cat);
+		cat_iter += 2;
+	}
+
+	return cat_iter;
+}
+
+/**
+ * cipso_v4_map_cat_enum_ntoh - Perform a category mapping from network to host
+ * @doi_def: the DOI definition
+ * @net_cat: the category list in network/CIPSO format
+ * @net_cat_len: the length of the CIPSO bitmap in bytes
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Perform a label mapping to translate a CIPSO category list to the correct
+ * local MLS category bitmap using the given DOI definition.  Returns zero on
+ * success, negative values on failure.
+ *
+ */
+static int cipso_v4_map_cat_enum_ntoh(const struct cipso_v4_doi *doi_def,
+				      const unsigned char *net_cat,
+				      u32 net_cat_len,
+				      struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u32 iter;
+
+	for (iter = 0; iter < net_cat_len; iter += 2) {
+		ret_val = netlbl_secattr_catmap_setbit(secattr->attr.mls.cat,
+				get_unaligned_be16(&net_cat[iter]),
+				GFP_ATOMIC);
+		if (ret_val != 0)
+			return ret_val;
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_map_cat_rng_valid - Checks to see if the categories are valid
+ * @doi_def: the DOI definition
+ * @rngcat: category list
+ * @rngcat_len: length of the category list in bytes
+ *
+ * Description:
+ * Checks the given categories against the given DOI definition and returns a
+ * negative value if any of the categories do not have a valid mapping and a
+ * zero value if all of the categories are valid.
+ *
+ */
+static int cipso_v4_map_cat_rng_valid(const struct cipso_v4_doi *doi_def,
+				      const unsigned char *rngcat,
+				      u32 rngcat_len)
+{
+	u16 cat_high;
+	u16 cat_low;
+	u32 cat_prev = CIPSO_V4_MAX_REM_CATS + 1;
+	u32 iter;
+
+	if (doi_def->type != CIPSO_V4_MAP_PASS || rngcat_len & 0x01)
+		return -EFAULT;
+
+	for (iter = 0; iter < rngcat_len; iter += 4) {
+		cat_high = get_unaligned_be16(&rngcat[iter]);
+		if ((iter + 4) <= rngcat_len)
+			cat_low = get_unaligned_be16(&rngcat[iter + 2]);
+		else
+			cat_low = 0;
+
+		if (cat_high > cat_prev)
+			return -EFAULT;
+
+		cat_prev = cat_low;
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_map_cat_rng_hton - Perform a category mapping from host to network
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @net_cat: the zero'd out category list in network/CIPSO format
+ * @net_cat_len: the length of the CIPSO category list in bytes
+ *
+ * Description:
+ * Perform a label mapping to translate a local MLS category bitmap to the
+ * correct CIPSO category list using the given DOI definition.   Returns the
+ * size in bytes of the network category bitmap on success, negative values
+ * otherwise.
+ *
+ */
+static int cipso_v4_map_cat_rng_hton(const struct cipso_v4_doi *doi_def,
+				     const struct netlbl_lsm_secattr *secattr,
+				     unsigned char *net_cat,
+				     u32 net_cat_len)
+{
+	int iter = -1;
+	u16 array[CIPSO_V4_TAG_RNG_CAT_MAX * 2];
+	u32 array_cnt = 0;
+	u32 cat_size = 0;
+
+	/* make sure we don't overflow the 'array[]' variable */
+	if (net_cat_len >
+	    (CIPSO_V4_OPT_LEN_MAX - CIPSO_V4_HDR_LEN - CIPSO_V4_TAG_RNG_BLEN))
+		return -ENOSPC;
+
+	for (;;) {
+		iter = netlbl_secattr_catmap_walk(secattr->attr.mls.cat,
+						  iter + 1);
+		if (iter < 0)
+			break;
+		cat_size += (iter == 0 ? 0 : sizeof(u16));
+		if (cat_size > net_cat_len)
+			return -ENOSPC;
+		array[array_cnt++] = iter;
+
+		iter = netlbl_secattr_catmap_walk_rng(secattr->attr.mls.cat,
+						      iter);
+		if (iter < 0)
+			return -EFAULT;
+		cat_size += sizeof(u16);
+		if (cat_size > net_cat_len)
+			return -ENOSPC;
+		array[array_cnt++] = iter;
+	}
+
+	for (iter = 0; array_cnt > 0;) {
+		*((__be16 *)&net_cat[iter]) = htons(array[--array_cnt]);
+		iter += 2;
+		array_cnt--;
+		if (array[array_cnt] != 0) {
+			*((__be16 *)&net_cat[iter]) = htons(array[array_cnt]);
+			iter += 2;
+		}
+	}
+
+	return cat_size;
+}
+
+/**
+ * cipso_v4_map_cat_rng_ntoh - Perform a category mapping from network to host
+ * @doi_def: the DOI definition
+ * @net_cat: the category list in network/CIPSO format
+ * @net_cat_len: the length of the CIPSO bitmap in bytes
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Perform a label mapping to translate a CIPSO category list to the correct
+ * local MLS category bitmap using the given DOI definition.  Returns zero on
+ * success, negative values on failure.
+ *
+ */
+static int cipso_v4_map_cat_rng_ntoh(const struct cipso_v4_doi *doi_def,
+				     const unsigned char *net_cat,
+				     u32 net_cat_len,
+				     struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u32 net_iter;
+	u16 cat_low;
+	u16 cat_high;
+
+	for (net_iter = 0; net_iter < net_cat_len; net_iter += 4) {
+		cat_high = get_unaligned_be16(&net_cat[net_iter]);
+		if ((net_iter + 4) <= net_cat_len)
+			cat_low = get_unaligned_be16(&net_cat[net_iter + 2]);
+		else
+			cat_low = 0;
+
+		ret_val = netlbl_secattr_catmap_setrng(secattr->attr.mls.cat,
+						       cat_low,
+						       cat_high,
+						       GFP_ATOMIC);
+		if (ret_val != 0)
+			return ret_val;
+	}
+
+	return 0;
+}
+
+/*
+ * Protocol Handling Functions
+ */
+
+/**
+ * cipso_v4_gentag_hdr - Generate a CIPSO option header
+ * @doi_def: the DOI definition
+ * @len: the total tag length in bytes, not including this header
+ * @buf: the CIPSO option buffer
+ *
+ * Description:
+ * Write a CIPSO header into the beginning of @buffer.
+ *
+ */
+static void cipso_v4_gentag_hdr(const struct cipso_v4_doi *doi_def,
+				unsigned char *buf,
+				u32 len)
+{
+	buf[0] = IPOPT_CIPSO;
+	buf[1] = CIPSO_V4_HDR_LEN + len;
+	*(__be32 *)&buf[2] = htonl(doi_def->doi);
+}
+
+/**
+ * cipso_v4_gentag_rbm - Generate a CIPSO restricted bitmap tag (type #1)
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @buffer: the option buffer
+ * @buffer_len: length of buffer in bytes
+ *
+ * Description:
+ * Generate a CIPSO option using the restricted bitmap tag, tag type #1.  The
+ * actual buffer length may be larger than the indicated size due to
+ * translation between host and network category bitmaps.  Returns the size of
+ * the tag on success, negative values on failure.
+ *
+ */
+static int cipso_v4_gentag_rbm(const struct cipso_v4_doi *doi_def,
+			       const struct netlbl_lsm_secattr *secattr,
+			       unsigned char *buffer,
+			       u32 buffer_len)
+{
+	int ret_val;
+	u32 tag_len;
+	u32 level;
+
+	if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
+		return -EPERM;
+
+	ret_val = cipso_v4_map_lvl_hton(doi_def,
+					secattr->attr.mls.lvl,
+					&level);
+	if (ret_val != 0)
+		return ret_val;
+
+	if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
+		ret_val = cipso_v4_map_cat_rbm_hton(doi_def,
+						    secattr,
+						    &buffer[4],
+						    buffer_len - 4);
+		if (ret_val < 0)
+			return ret_val;
+
+		/* This will send packets using the "optimized" format when
+		 * possibile as specified in  section 3.4.2.6 of the
+		 * CIPSO draft. */
+		if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
+			tag_len = 14;
+		else
+			tag_len = 4 + ret_val;
+	} else
+		tag_len = 4;
+
+	buffer[0] = CIPSO_V4_TAG_RBITMAP;
+	buffer[1] = tag_len;
+	buffer[3] = level;
+
+	return tag_len;
+}
+
+/**
+ * cipso_v4_parsetag_rbm - Parse a CIPSO restricted bitmap tag
+ * @doi_def: the DOI definition
+ * @tag: the CIPSO tag
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Parse a CIPSO restricted bitmap tag (tag type #1) and return the security
+ * attributes in @secattr.  Return zero on success, negatives values on
+ * failure.
+ *
+ */
+static int cipso_v4_parsetag_rbm(const struct cipso_v4_doi *doi_def,
+				 const unsigned char *tag,
+				 struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u8 tag_len = tag[1];
+	u32 level;
+
+	ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
+	if (ret_val != 0)
+		return ret_val;
+	secattr->attr.mls.lvl = level;
+	secattr->flags |= NETLBL_SECATTR_MLS_LVL;
+
+	if (tag_len > 4) {
+		secattr->attr.mls.cat =
+		                       netlbl_secattr_catmap_alloc(GFP_ATOMIC);
+		if (secattr->attr.mls.cat == NULL)
+			return -ENOMEM;
+
+		ret_val = cipso_v4_map_cat_rbm_ntoh(doi_def,
+						    &tag[4],
+						    tag_len - 4,
+						    secattr);
+		if (ret_val != 0) {
+			netlbl_secattr_catmap_free(secattr->attr.mls.cat);
+			return ret_val;
+		}
+
+		secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_gentag_enum - Generate a CIPSO enumerated tag (type #2)
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @buffer: the option buffer
+ * @buffer_len: length of buffer in bytes
+ *
+ * Description:
+ * Generate a CIPSO option using the enumerated tag, tag type #2.  Returns the
+ * size of the tag on success, negative values on failure.
+ *
+ */
+static int cipso_v4_gentag_enum(const struct cipso_v4_doi *doi_def,
+				const struct netlbl_lsm_secattr *secattr,
+				unsigned char *buffer,
+				u32 buffer_len)
+{
+	int ret_val;
+	u32 tag_len;
+	u32 level;
+
+	if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
+		return -EPERM;
+
+	ret_val = cipso_v4_map_lvl_hton(doi_def,
+					secattr->attr.mls.lvl,
+					&level);
+	if (ret_val != 0)
+		return ret_val;
+
+	if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
+		ret_val = cipso_v4_map_cat_enum_hton(doi_def,
+						     secattr,
+						     &buffer[4],
+						     buffer_len - 4);
+		if (ret_val < 0)
+			return ret_val;
+
+		tag_len = 4 + ret_val;
+	} else
+		tag_len = 4;
+
+	buffer[0] = CIPSO_V4_TAG_ENUM;
+	buffer[1] = tag_len;
+	buffer[3] = level;
+
+	return tag_len;
+}
+
+/**
+ * cipso_v4_parsetag_enum - Parse a CIPSO enumerated tag
+ * @doi_def: the DOI definition
+ * @tag: the CIPSO tag
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Parse a CIPSO enumerated tag (tag type #2) and return the security
+ * attributes in @secattr.  Return zero on success, negatives values on
+ * failure.
+ *
+ */
+static int cipso_v4_parsetag_enum(const struct cipso_v4_doi *doi_def,
+				  const unsigned char *tag,
+				  struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u8 tag_len = tag[1];
+	u32 level;
+
+	ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
+	if (ret_val != 0)
+		return ret_val;
+	secattr->attr.mls.lvl = level;
+	secattr->flags |= NETLBL_SECATTR_MLS_LVL;
+
+	if (tag_len > 4) {
+		secattr->attr.mls.cat =
+			               netlbl_secattr_catmap_alloc(GFP_ATOMIC);
+		if (secattr->attr.mls.cat == NULL)
+			return -ENOMEM;
+
+		ret_val = cipso_v4_map_cat_enum_ntoh(doi_def,
+						     &tag[4],
+						     tag_len - 4,
+						     secattr);
+		if (ret_val != 0) {
+			netlbl_secattr_catmap_free(secattr->attr.mls.cat);
+			return ret_val;
+		}
+
+		secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_gentag_rng - Generate a CIPSO ranged tag (type #5)
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @buffer: the option buffer
+ * @buffer_len: length of buffer in bytes
+ *
+ * Description:
+ * Generate a CIPSO option using the ranged tag, tag type #5.  Returns the
+ * size of the tag on success, negative values on failure.
+ *
+ */
+static int cipso_v4_gentag_rng(const struct cipso_v4_doi *doi_def,
+			       const struct netlbl_lsm_secattr *secattr,
+			       unsigned char *buffer,
+			       u32 buffer_len)
+{
+	int ret_val;
+	u32 tag_len;
+	u32 level;
+
+	if (!(secattr->flags & NETLBL_SECATTR_MLS_LVL))
+		return -EPERM;
+
+	ret_val = cipso_v4_map_lvl_hton(doi_def,
+					secattr->attr.mls.lvl,
+					&level);
+	if (ret_val != 0)
+		return ret_val;
+
+	if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
+		ret_val = cipso_v4_map_cat_rng_hton(doi_def,
+						    secattr,
+						    &buffer[4],
+						    buffer_len - 4);
+		if (ret_val < 0)
+			return ret_val;
+
+		tag_len = 4 + ret_val;
+	} else
+		tag_len = 4;
+
+	buffer[0] = CIPSO_V4_TAG_RANGE;
+	buffer[1] = tag_len;
+	buffer[3] = level;
+
+	return tag_len;
+}
+
+/**
+ * cipso_v4_parsetag_rng - Parse a CIPSO ranged tag
+ * @doi_def: the DOI definition
+ * @tag: the CIPSO tag
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Parse a CIPSO ranged tag (tag type #5) and return the security attributes
+ * in @secattr.  Return zero on success, negatives values on failure.
+ *
+ */
+static int cipso_v4_parsetag_rng(const struct cipso_v4_doi *doi_def,
+				 const unsigned char *tag,
+				 struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u8 tag_len = tag[1];
+	u32 level;
+
+	ret_val = cipso_v4_map_lvl_ntoh(doi_def, tag[3], &level);
+	if (ret_val != 0)
+		return ret_val;
+	secattr->attr.mls.lvl = level;
+	secattr->flags |= NETLBL_SECATTR_MLS_LVL;
+
+	if (tag_len > 4) {
+		secattr->attr.mls.cat =
+			               netlbl_secattr_catmap_alloc(GFP_ATOMIC);
+		if (secattr->attr.mls.cat == NULL)
+			return -ENOMEM;
+
+		ret_val = cipso_v4_map_cat_rng_ntoh(doi_def,
+						    &tag[4],
+						    tag_len - 4,
+						    secattr);
+		if (ret_val != 0) {
+			netlbl_secattr_catmap_free(secattr->attr.mls.cat);
+			return ret_val;
+		}
+
+		secattr->flags |= NETLBL_SECATTR_MLS_CAT;
+	}
+
+	return 0;
+}
+
+/**
+ * cipso_v4_gentag_loc - Generate a CIPSO local tag (non-standard)
+ * @doi_def: the DOI definition
+ * @secattr: the security attributes
+ * @buffer: the option buffer
+ * @buffer_len: length of buffer in bytes
+ *
+ * Description:
+ * Generate a CIPSO option using the local tag.  Returns the size of the tag
+ * on success, negative values on failure.
+ *
+ */
+static int cipso_v4_gentag_loc(const struct cipso_v4_doi *doi_def,
+			       const struct netlbl_lsm_secattr *secattr,
+			       unsigned char *buffer,
+			       u32 buffer_len)
+{
+	if (!(secattr->flags & NETLBL_SECATTR_SECID))
+		return -EPERM;
+
+	buffer[0] = CIPSO_V4_TAG_LOCAL;
+	buffer[1] = CIPSO_V4_TAG_LOC_BLEN;
+	*(u32 *)&buffer[2] = secattr->attr.secid;
+
+	return CIPSO_V4_TAG_LOC_BLEN;
+}
+
+/**
+ * cipso_v4_parsetag_loc - Parse a CIPSO local tag
+ * @doi_def: the DOI definition
+ * @tag: the CIPSO tag
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Parse a CIPSO local tag and return the security attributes in @secattr.
+ * Return zero on success, negatives values on failure.
+ *
+ */
+static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
+				 const unsigned char *tag,
+				 struct netlbl_lsm_secattr *secattr)
+{
+	secattr->attr.secid = *(u32 *)&tag[2];
+	secattr->flags |= NETLBL_SECATTR_SECID;
+
+	return 0;
+}
+
+/**
+ * cipso_v4_validate - Validate a CIPSO option
+ * @option: the start of the option, on error it is set to point to the error
+ *
+ * Description:
+ * This routine is called to validate a CIPSO option, it checks all of the
+ * fields to ensure that they are at least valid, see the draft snippet below
+ * for details.  If the option is valid then a zero value is returned and
+ * the value of @option is unchanged.  If the option is invalid then a
+ * non-zero value is returned and @option is adjusted to point to the
+ * offending portion of the option.  From the IETF draft ...
+ *
+ *  "If any field within the CIPSO options, such as the DOI identifier, is not
+ *   recognized the IP datagram is discarded and an ICMP 'parameter problem'
+ *   (type 12) is generated and returned.  The ICMP code field is set to 'bad
+ *   parameter' (code 0) and the pointer is set to the start of the CIPSO field
+ *   that is unrecognized."
+ *
+ */
+int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option)
+{
+	unsigned char *opt = *option;
+	unsigned char *tag;
+	unsigned char opt_iter;
+	unsigned char err_offset = 0;
+	u8 opt_len;
+	u8 tag_len;
+	struct cipso_v4_doi *doi_def = NULL;
+	u32 tag_iter;
+
+	/* caller already checks for length values that are too large */
+	opt_len = opt[1];
+	if (opt_len < 8) {
+		err_offset = 1;
+		goto validate_return;
+	}
+
+	rcu_read_lock();
+	doi_def = cipso_v4_doi_search(get_unaligned_be32(&opt[2]));
+	if (doi_def == NULL) {
+		err_offset = 2;
+		goto validate_return_locked;
+	}
+
+	opt_iter = CIPSO_V4_HDR_LEN;
+	tag = opt + opt_iter;
+	while (opt_iter < opt_len) {
+		for (tag_iter = 0; doi_def->tags[tag_iter] != tag[0];)
+			if (doi_def->tags[tag_iter] == CIPSO_V4_TAG_INVALID ||
+			    ++tag_iter == CIPSO_V4_TAG_MAXCNT) {
+				err_offset = opt_iter;
+				goto validate_return_locked;
+			}
+
+		tag_len = tag[1];
+		if (tag_len > (opt_len - opt_iter)) {
+			err_offset = opt_iter + 1;
+			goto validate_return_locked;
+		}
+
+		switch (tag[0]) {
+		case CIPSO_V4_TAG_RBITMAP:
+			if (tag_len < CIPSO_V4_TAG_RBM_BLEN) {
+				err_offset = opt_iter + 1;
+				goto validate_return_locked;
+			}
+
+			/* We are already going to do all the verification
+			 * necessary at the socket layer so from our point of
+			 * view it is safe to turn these checks off (and less
+			 * work), however, the CIPSO draft says we should do
+			 * all the CIPSO validations here but it doesn't
+			 * really specify _exactly_ what we need to validate
+			 * ... so, just make it a sysctl tunable. */
+			if (cipso_v4_rbm_strictvalid) {
+				if (cipso_v4_map_lvl_valid(doi_def,
+							   tag[3]) < 0) {
+					err_offset = opt_iter + 3;
+					goto validate_return_locked;
+				}
+				if (tag_len > CIPSO_V4_TAG_RBM_BLEN &&
+				    cipso_v4_map_cat_rbm_valid(doi_def,
+							    &tag[4],
+							    tag_len - 4) < 0) {
+					err_offset = opt_iter + 4;
+					goto validate_return_locked;
+				}
+			}
+			break;
+		case CIPSO_V4_TAG_ENUM:
+			if (tag_len < CIPSO_V4_TAG_ENUM_BLEN) {
+				err_offset = opt_iter + 1;
+				goto validate_return_locked;
+			}
+
+			if (cipso_v4_map_lvl_valid(doi_def,
+						   tag[3]) < 0) {
+				err_offset = opt_iter + 3;
+				goto validate_return_locked;
+			}
+			if (tag_len > CIPSO_V4_TAG_ENUM_BLEN &&
+			    cipso_v4_map_cat_enum_valid(doi_def,
+							&tag[4],
+							tag_len - 4) < 0) {
+				err_offset = opt_iter + 4;
+				goto validate_return_locked;
+			}
+			break;
+		case CIPSO_V4_TAG_RANGE:
+			if (tag_len < CIPSO_V4_TAG_RNG_BLEN) {
+				err_offset = opt_iter + 1;
+				goto validate_return_locked;
+			}
+
+			if (cipso_v4_map_lvl_valid(doi_def,
+						   tag[3]) < 0) {
+				err_offset = opt_iter + 3;
+				goto validate_return_locked;
+			}
+			if (tag_len > CIPSO_V4_TAG_RNG_BLEN &&
+			    cipso_v4_map_cat_rng_valid(doi_def,
+						       &tag[4],
+						       tag_len - 4) < 0) {
+				err_offset = opt_iter + 4;
+				goto validate_return_locked;
+			}
+			break;
+		case CIPSO_V4_TAG_LOCAL:
+			/* This is a non-standard tag that we only allow for
+			 * local connections, so if the incoming interface is
+			 * not the loopback device drop the packet. */
+			if (!(skb->dev->flags & IFF_LOOPBACK)) {
+				err_offset = opt_iter;
+				goto validate_return_locked;
+			}
+			if (tag_len != CIPSO_V4_TAG_LOC_BLEN) {
+				err_offset = opt_iter + 1;
+				goto validate_return_locked;
+			}
+			break;
+		default:
+			err_offset = opt_iter;
+			goto validate_return_locked;
+		}
+
+		tag += tag_len;
+		opt_iter += tag_len;
+	}
+
+validate_return_locked:
+	rcu_read_unlock();
+validate_return:
+	*option = opt + err_offset;
+	return err_offset;
+}
+
+/**
+ * cipso_v4_error - Send the correct reponse for a bad packet
+ * @skb: the packet
+ * @error: the error code
+ * @gateway: CIPSO gateway flag
+ *
+ * Description:
+ * Based on the error code given in @error, send an ICMP error message back to
+ * the originating host.  From the IETF draft ...
+ *
+ *  "If the contents of the CIPSO [option] are valid but the security label is
+ *   outside of the configured host or port label range, the datagram is
+ *   discarded and an ICMP 'destination unreachable' (type 3) is generated and
+ *   returned.  The code field of the ICMP is set to 'communication with
+ *   destination network administratively prohibited' (code 9) or to
+ *   'communication with destination host administratively prohibited'
+ *   (code 10).  The value of the code is dependent on whether the originator
+ *   of the ICMP message is acting as a CIPSO host or a CIPSO gateway.  The
+ *   recipient of the ICMP message MUST be able to handle either value.  The
+ *   same procedure is performed if a CIPSO [option] can not be added to an
+ *   IP packet because it is too large to fit in the IP options area."
+ *
+ *  "If the error is triggered by receipt of an ICMP message, the message is
+ *   discarded and no response is permitted (consistent with general ICMP
+ *   processing rules)."
+ *
+ */
+void cipso_v4_error(struct sk_buff *skb, int error, u32 gateway)
+{
+	if (ip_hdr(skb)->protocol == IPPROTO_ICMP || error != -EACCES)
+		return;
+
+	if (gateway)
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_ANO, 0);
+	else
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_ANO, 0);
+}
+
+/**
+ * cipso_v4_genopt - Generate a CIPSO option
+ * @buf: the option buffer
+ * @buf_len: the size of opt_buf
+ * @doi_def: the CIPSO DOI to use
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Generate a CIPSO option using the DOI definition and security attributes
+ * passed to the function.  Returns the length of the option on success and
+ * negative values on failure.
+ *
+ */
+static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
+			   const struct cipso_v4_doi *doi_def,
+			   const struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	u32 iter;
+
+	if (buf_len <= CIPSO_V4_HDR_LEN)
+		return -ENOSPC;
+
+	/* XXX - This code assumes only one tag per CIPSO option which isn't
+	 * really a good assumption to make but since we only support the MAC
+	 * tags right now it is a safe assumption. */
+	iter = 0;
+	do {
+		memset(buf, 0, buf_len);
+		switch (doi_def->tags[iter]) {
+		case CIPSO_V4_TAG_RBITMAP:
+			ret_val = cipso_v4_gentag_rbm(doi_def,
+						   secattr,
+						   &buf[CIPSO_V4_HDR_LEN],
+						   buf_len - CIPSO_V4_HDR_LEN);
+			break;
+		case CIPSO_V4_TAG_ENUM:
+			ret_val = cipso_v4_gentag_enum(doi_def,
+						   secattr,
+						   &buf[CIPSO_V4_HDR_LEN],
+						   buf_len - CIPSO_V4_HDR_LEN);
+			break;
+		case CIPSO_V4_TAG_RANGE:
+			ret_val = cipso_v4_gentag_rng(doi_def,
+						   secattr,
+						   &buf[CIPSO_V4_HDR_LEN],
+						   buf_len - CIPSO_V4_HDR_LEN);
+			break;
+		case CIPSO_V4_TAG_LOCAL:
+			ret_val = cipso_v4_gentag_loc(doi_def,
+						   secattr,
+						   &buf[CIPSO_V4_HDR_LEN],
+						   buf_len - CIPSO_V4_HDR_LEN);
+			break;
+		default:
+			return -EPERM;
+		}
+
+		iter++;
+	} while (ret_val < 0 &&
+		 iter < CIPSO_V4_TAG_MAXCNT &&
+		 doi_def->tags[iter] != CIPSO_V4_TAG_INVALID);
+	if (ret_val < 0)
+		return ret_val;
+	cipso_v4_gentag_hdr(doi_def, buf, ret_val);
+	return CIPSO_V4_HDR_LEN + ret_val;
+}
+
+/**
+ * cipso_v4_sock_setattr - Add a CIPSO option to a socket
+ * @sk: the socket
+ * @doi_def: the CIPSO DOI to use
+ * @secattr: the specific security attributes of the socket
+ *
+ * Description:
+ * Set the CIPSO option on the given socket using the DOI definition and
+ * security attributes passed to the function.  This function requires
+ * exclusive access to @sk, which means it either needs to be in the
+ * process of being created or locked.  Returns zero on success and negative
+ * values on failure.
+ *
+ */
+int cipso_v4_sock_setattr(struct sock *sk,
+			  const struct cipso_v4_doi *doi_def,
+			  const struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val = -EPERM;
+	unsigned char *buf = NULL;
+	u32 buf_len;
+	u32 opt_len;
+	struct ip_options *opt = NULL;
+	struct inet_sock *sk_inet;
+	struct inet_connection_sock *sk_conn;
+
+	/* In the case of sock_create_lite(), the sock->sk field is not
+	 * defined yet but it is not a problem as the only users of these
+	 * "lite" PF_INET sockets are functions which do an accept() call
+	 * afterwards so we will label the socket as part of the accept(). */
+	if (sk == NULL)
+		return 0;
+
+	/* We allocate the maximum CIPSO option size here so we are probably
+	 * being a little wasteful, but it makes our life _much_ easier later
+	 * on and after all we are only talking about 40 bytes. */
+	buf_len = CIPSO_V4_OPT_LEN_MAX;
+	buf = kmalloc(buf_len, GFP_ATOMIC);
+	if (buf == NULL) {
+		ret_val = -ENOMEM;
+		goto socket_setattr_failure;
+	}
+
+	ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
+	if (ret_val < 0)
+		goto socket_setattr_failure;
+	buf_len = ret_val;
+
+	/* We can't use ip_options_get() directly because it makes a call to
+	 * ip_options_get_alloc() which allocates memory with GFP_KERNEL and
+	 * we won't always have CAP_NET_RAW even though we _always_ want to
+	 * set the IPOPT_CIPSO option. */
+	opt_len = (buf_len + 3) & ~3;
+	opt = kzalloc(sizeof(*opt) + opt_len, GFP_ATOMIC);
+	if (opt == NULL) {
+		ret_val = -ENOMEM;
+		goto socket_setattr_failure;
+	}
+	memcpy(opt->__data, buf, buf_len);
+	opt->optlen = opt_len;
+	opt->cipso = sizeof(struct iphdr);
+	kfree(buf);
+	buf = NULL;
+
+	sk_inet = inet_sk(sk);
+	if (sk_inet->is_icsk) {
+		sk_conn = inet_csk(sk);
+		if (sk_inet->opt)
+			sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen;
+		sk_conn->icsk_ext_hdr_len += opt->optlen;
+		sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
+	}
+	opt = xchg(&sk_inet->opt, opt);
+	kfree(opt);
+
+	return 0;
+
+socket_setattr_failure:
+	kfree(buf);
+	kfree(opt);
+	return ret_val;
+}
+
+/**
+ * cipso_v4_sock_delattr - Delete the CIPSO option from a socket
+ * @sk: the socket
+ *
+ * Description:
+ * Removes the CIPSO option from a socket, if present.
+ *
+ */
+void cipso_v4_sock_delattr(struct sock *sk)
+{
+	u8 hdr_delta;
+	struct ip_options *opt;
+	struct inet_sock *sk_inet;
+
+	sk_inet = inet_sk(sk);
+	opt = sk_inet->opt;
+	if (opt == NULL || opt->cipso == 0)
+		return;
+
+	if (opt->srr || opt->rr || opt->ts || opt->router_alert) {
+		u8 cipso_len;
+		u8 cipso_off;
+		unsigned char *cipso_ptr;
+		int iter;
+		int optlen_new;
+
+		cipso_off = opt->cipso - sizeof(struct iphdr);
+		cipso_ptr = &opt->__data[cipso_off];
+		cipso_len = cipso_ptr[1];
+
+		if (opt->srr > opt->cipso)
+			opt->srr -= cipso_len;
+		if (opt->rr > opt->cipso)
+			opt->rr -= cipso_len;
+		if (opt->ts > opt->cipso)
+			opt->ts -= cipso_len;
+		if (opt->router_alert > opt->cipso)
+			opt->router_alert -= cipso_len;
+		opt->cipso = 0;
+
+		memmove(cipso_ptr, cipso_ptr + cipso_len,
+			opt->optlen - cipso_off - cipso_len);
+
+		/* determining the new total option length is tricky because of
+		 * the padding necessary, the only thing i can think to do at
+		 * this point is walk the options one-by-one, skipping the
+		 * padding at the end to determine the actual option size and
+		 * from there we can determine the new total option length */
+		iter = 0;
+		optlen_new = 0;
+		while (iter < opt->optlen)
+			if (opt->__data[iter] != IPOPT_NOP) {
+				iter += opt->__data[iter + 1];
+				optlen_new = iter;
+			} else
+				iter++;
+		hdr_delta = opt->optlen;
+		opt->optlen = (optlen_new + 3) & ~3;
+		hdr_delta -= opt->optlen;
+	} else {
+		/* only the cipso option was present on the socket so we can
+		 * remove the entire option struct */
+		sk_inet->opt = NULL;
+		hdr_delta = opt->optlen;
+		kfree(opt);
+	}
+
+	if (sk_inet->is_icsk && hdr_delta > 0) {
+		struct inet_connection_sock *sk_conn = inet_csk(sk);
+		sk_conn->icsk_ext_hdr_len -= hdr_delta;
+		sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
+	}
+}
+
+/**
+ * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
+ * @cipso: the CIPSO v4 option
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Inspect @cipso and return the security attributes in @secattr.  Returns zero
+ * on success and negative values on failure.
+ *
+ */
+static int cipso_v4_getattr(const unsigned char *cipso,
+			    struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val = -ENOMSG;
+	u32 doi;
+	struct cipso_v4_doi *doi_def;
+
+	if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
+		return 0;
+
+	doi = get_unaligned_be32(&cipso[2]);
+	rcu_read_lock();
+	doi_def = cipso_v4_doi_search(doi);
+	if (doi_def == NULL)
+		goto getattr_return;
+	/* XXX - This code assumes only one tag per CIPSO option which isn't
+	 * really a good assumption to make but since we only support the MAC
+	 * tags right now it is a safe assumption. */
+	switch (cipso[6]) {
+	case CIPSO_V4_TAG_RBITMAP:
+		ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
+		break;
+	case CIPSO_V4_TAG_ENUM:
+		ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
+		break;
+	case CIPSO_V4_TAG_RANGE:
+		ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
+		break;
+	case CIPSO_V4_TAG_LOCAL:
+		ret_val = cipso_v4_parsetag_loc(doi_def, &cipso[6], secattr);
+		break;
+	}
+	if (ret_val == 0)
+		secattr->type = NETLBL_NLTYPE_CIPSOV4;
+
+getattr_return:
+	rcu_read_unlock();
+	return ret_val;
+}
+
+/**
+ * cipso_v4_sock_getattr - Get the security attributes from a sock
+ * @sk: the sock
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Query @sk to see if there is a CIPSO option attached to the sock and if
+ * there is return the CIPSO security attributes in @secattr.  This function
+ * requires that @sk be locked, or privately held, but it does not do any
+ * locking itself.  Returns zero on success and negative values on failure.
+ *
+ */
+int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
+{
+	struct ip_options *opt;
+
+	opt = inet_sk(sk)->opt;
+	if (opt == NULL || opt->cipso == 0)
+		return -ENOMSG;
+
+	return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr),
+				secattr);
+}
+
+/**
+ * cipso_v4_skbuff_setattr - Set the CIPSO option on a packet
+ * @skb: the packet
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Set the CIPSO option on the given packet based on the security attributes.
+ * Returns a pointer to the IP header on success and NULL on failure.
+ *
+ */
+int cipso_v4_skbuff_setattr(struct sk_buff *skb,
+			    const struct cipso_v4_doi *doi_def,
+			    const struct netlbl_lsm_secattr *secattr)
+{
+	int ret_val;
+	struct iphdr *iph;
+	struct ip_options *opt = &IPCB(skb)->opt;
+	unsigned char buf[CIPSO_V4_OPT_LEN_MAX];
+	u32 buf_len = CIPSO_V4_OPT_LEN_MAX;
+	u32 opt_len;
+	int len_delta;
+
+	ret_val = cipso_v4_genopt(buf, buf_len, doi_def, secattr);
+	if (ret_val < 0)
+		return ret_val;
+	buf_len = ret_val;
+	opt_len = (buf_len + 3) & ~3;
+
+	/* we overwrite any existing options to ensure that we have enough
+	 * room for the CIPSO option, the reason is that we _need_ to guarantee
+	 * that the security label is applied to the packet - we do the same
+	 * thing when using the socket options and it hasn't caused a problem,
+	 * if we need to we can always revisit this choice later */
+
+	len_delta = opt_len - opt->optlen;
+	/* if we don't ensure enough headroom we could panic on the skb_push()
+	 * call below so make sure we have enough, we are also "mangling" the
+	 * packet so we should probably do a copy-on-write call anyway */
+	ret_val = skb_cow(skb, skb_headroom(skb) + len_delta);
+	if (ret_val < 0)
+		return ret_val;
+
+	if (len_delta > 0) {
+		/* we assume that the header + opt->optlen have already been
+		 * "pushed" in ip_options_build() or similar */
+		iph = ip_hdr(skb);
+		skb_push(skb, len_delta);
+		memmove((char *)iph - len_delta, iph, iph->ihl << 2);
+		skb_reset_network_header(skb);
+		iph = ip_hdr(skb);
+	} else if (len_delta < 0) {
+		iph = ip_hdr(skb);
+		memset(iph + 1, IPOPT_NOP, opt->optlen);
+	} else
+		iph = ip_hdr(skb);
+
+	if (opt->optlen > 0)
+		memset(opt, 0, sizeof(*opt));
+	opt->optlen = opt_len;
+	opt->cipso = sizeof(struct iphdr);
+	opt->is_changed = 1;
+
+	/* we have to do the following because we are being called from a
+	 * netfilter hook which means the packet already has had the header
+	 * fields populated and the checksum calculated - yes this means we
+	 * are doing more work than needed but we do it to keep the core
+	 * stack clean and tidy */
+	memcpy(iph + 1, buf, buf_len);
+	if (opt_len > buf_len)
+		memset((char *)(iph + 1) + buf_len, 0, opt_len - buf_len);
+	if (len_delta != 0) {
+		iph->ihl = 5 + (opt_len >> 2);
+		iph->tot_len = htons(skb->len);
+	}
+	ip_send_check(iph);
+
+	return 0;
+}
+
+/**
+ * cipso_v4_skbuff_delattr - Delete any CIPSO options from a packet
+ * @skb: the packet
+ *
+ * Description:
+ * Removes any and all CIPSO options from the given packet.  Returns zero on
+ * success, negative values on failure.
+ *
+ */
+int cipso_v4_skbuff_delattr(struct sk_buff *skb)
+{
+	int ret_val;
+	struct iphdr *iph;
+	struct ip_options *opt = &IPCB(skb)->opt;
+	unsigned char *cipso_ptr;
+
+	if (opt->cipso == 0)
+		return 0;
+
+	/* since we are changing the packet we should make a copy */
+	ret_val = skb_cow(skb, skb_headroom(skb));
+	if (ret_val < 0)
+		return ret_val;
+
+	/* the easiest thing to do is just replace the cipso option with noop
+	 * options since we don't change the size of the packet, although we
+	 * still need to recalculate the checksum */
+
+	iph = ip_hdr(skb);
+	cipso_ptr = (unsigned char *)iph + opt->cipso;
+	memset(cipso_ptr, IPOPT_NOOP, cipso_ptr[1]);
+	opt->cipso = 0;
+	opt->is_changed = 1;
+
+	ip_send_check(iph);
+
+	return 0;
+}
+
+/**
+ * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
+ * @skb: the packet
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Parse the given packet's CIPSO option and return the security attributes.
+ * Returns zero on success and negative values on failure.
+ *
+ */
+int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
+			    struct netlbl_lsm_secattr *secattr)
+{
+	return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb), secattr);
+}
+
+/*
+ * Setup Functions
+ */
+
+/**
+ * cipso_v4_init - Initialize the CIPSO module
+ *
+ * Description:
+ * Initialize the CIPSO module and prepare it for use.  Returns zero on success
+ * and negative values on failure.
+ *
+ */
+static int __init cipso_v4_init(void)
+{
+	int ret_val;
+
+	ret_val = cipso_v4_cache_init();
+	if (ret_val != 0)
+		panic("Failed to initialize the CIPSO/IPv4 cache (%d)\n",
+		      ret_val);
+
+	return 0;
+}
+
+subsys_initcall(cipso_v4_init);
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
new file mode 100644
index 0000000..5e6c5a0
--- /dev/null
+++ b/net/ipv4/datagram.c
@@ -0,0 +1,77 @@
+/*
+ *	common UDP/RAW code
+ *	Linux INET implementation
+ *
+ * Authors:
+ * 	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
+ *
+ * 	This program is free software; you can redistribute it and/or
+ * 	modify it under the terms of the GNU General Public License
+ * 	as published by the Free Software Foundation; either version
+ * 	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <net/ip.h>
+#include <net/sock.h>
+#include <net/route.h>
+#include <net/tcp_states.h>
+
+int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
+	struct rtable *rt;
+	__be32 saddr;
+	int oif;
+	int err;
+
+
+	if (addr_len < sizeof(*usin))
+		return -EINVAL;
+
+	if (usin->sin_family != AF_INET)
+		return -EAFNOSUPPORT;
+
+	sk_dst_reset(sk);
+
+	oif = sk->sk_bound_dev_if;
+	saddr = inet->saddr;
+	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
+		if (!oif)
+			oif = inet->mc_index;
+		if (!saddr)
+			saddr = inet->mc_addr;
+	}
+	err = ip_route_connect(&rt, usin->sin_addr.s_addr, saddr,
+			       RT_CONN_FLAGS(sk), oif,
+			       sk->sk_protocol,
+			       inet->sport, usin->sin_port, sk, 1);
+	if (err) {
+		if (err == -ENETUNREACH)
+			IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+		return err;
+	}
+
+	if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
+		ip_rt_put(rt);
+		return -EACCES;
+	}
+	if (!inet->saddr)
+		inet->saddr = rt->rt_src;	/* Update source address */
+	if (!inet->rcv_saddr)
+		inet->rcv_saddr = rt->rt_src;
+	inet->daddr = rt->rt_dst;
+	inet->dport = usin->sin_port;
+	sk->sk_state = TCP_ESTABLISHED;
+	inet->id = jiffies;
+
+	sk_dst_set(sk, &rt->u.dst);
+	return(0);
+}
+
+EXPORT_SYMBOL(ip4_datagram_connect);
+
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
new file mode 100644
index 0000000..56fce3a
--- /dev/null
+++ b/net/ipv4/devinet.c
@@ -0,0 +1,1673 @@
+/*
+ *	NET3	IP device support routines.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ *	Derived from the IP parts of dev.c 1.0.19
+ * 		Authors:	Ross Biro
+ *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *				Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *
+ *	Additional Authors:
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *	Changes:
+ *		Alexey Kuznetsov:	pa_* fields are replaced with ifaddr
+ *					lists.
+ *		Cyrus Durgin:		updated for kmod
+ *		Matthias Andree:	in devinet_ioctl, compare label and
+ *					address (4.4BSD alias style support),
+ *					fall back to comparing just the label
+ *					if no match found.
+ */
+
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/if_addr.h>
+#include <linux/if_ether.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/notifier.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+#include <linux/kmod.h>
+
+#include <net/arp.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/ip_fib.h>
+#include <net/rtnetlink.h>
+#include <net/net_namespace.h>
+
+static struct ipv4_devconf ipv4_devconf = {
+	.data = {
+		[NET_IPV4_CONF_ACCEPT_REDIRECTS - 1] = 1,
+		[NET_IPV4_CONF_SEND_REDIRECTS - 1] = 1,
+		[NET_IPV4_CONF_SECURE_REDIRECTS - 1] = 1,
+		[NET_IPV4_CONF_SHARED_MEDIA - 1] = 1,
+	},
+};
+
+static struct ipv4_devconf ipv4_devconf_dflt = {
+	.data = {
+		[NET_IPV4_CONF_ACCEPT_REDIRECTS - 1] = 1,
+		[NET_IPV4_CONF_SEND_REDIRECTS - 1] = 1,
+		[NET_IPV4_CONF_SECURE_REDIRECTS - 1] = 1,
+		[NET_IPV4_CONF_SHARED_MEDIA - 1] = 1,
+		[NET_IPV4_CONF_ACCEPT_SOURCE_ROUTE - 1] = 1,
+	},
+};
+
+#define IPV4_DEVCONF_DFLT(net, attr) \
+	IPV4_DEVCONF((*net->ipv4.devconf_dflt), attr)
+
+static const struct nla_policy ifa_ipv4_policy[IFA_MAX+1] = {
+	[IFA_LOCAL]     	= { .type = NLA_U32 },
+	[IFA_ADDRESS]   	= { .type = NLA_U32 },
+	[IFA_BROADCAST] 	= { .type = NLA_U32 },
+	[IFA_LABEL]     	= { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
+};
+
+static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
+
+static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
+static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
+			 int destroy);
+#ifdef CONFIG_SYSCTL
+static void devinet_sysctl_register(struct in_device *idev);
+static void devinet_sysctl_unregister(struct in_device *idev);
+#else
+static inline void devinet_sysctl_register(struct in_device *idev)
+{
+}
+static inline void devinet_sysctl_unregister(struct in_device *idev)
+{
+}
+#endif
+
+/* Locks all the inet devices. */
+
+static struct in_ifaddr *inet_alloc_ifa(void)
+{
+	struct in_ifaddr *ifa = kzalloc(sizeof(*ifa), GFP_KERNEL);
+
+	if (ifa) {
+		INIT_RCU_HEAD(&ifa->rcu_head);
+	}
+
+	return ifa;
+}
+
+static void inet_rcu_free_ifa(struct rcu_head *head)
+{
+	struct in_ifaddr *ifa = container_of(head, struct in_ifaddr, rcu_head);
+	if (ifa->ifa_dev)
+		in_dev_put(ifa->ifa_dev);
+	kfree(ifa);
+}
+
+static inline void inet_free_ifa(struct in_ifaddr *ifa)
+{
+	call_rcu(&ifa->rcu_head, inet_rcu_free_ifa);
+}
+
+void in_dev_finish_destroy(struct in_device *idev)
+{
+	struct net_device *dev = idev->dev;
+
+	WARN_ON(idev->ifa_list);
+	WARN_ON(idev->mc_list);
+#ifdef NET_REFCNT_DEBUG
+	printk(KERN_DEBUG "in_dev_finish_destroy: %p=%s\n",
+	       idev, dev ? dev->name : "NIL");
+#endif
+	dev_put(dev);
+	if (!idev->dead)
+		printk("Freeing alive in_device %p\n", idev);
+	else {
+		kfree(idev);
+	}
+}
+
+static struct in_device *inetdev_init(struct net_device *dev)
+{
+	struct in_device *in_dev;
+
+	ASSERT_RTNL();
+
+	in_dev = kzalloc(sizeof(*in_dev), GFP_KERNEL);
+	if (!in_dev)
+		goto out;
+	INIT_RCU_HEAD(&in_dev->rcu_head);
+	memcpy(&in_dev->cnf, dev_net(dev)->ipv4.devconf_dflt,
+			sizeof(in_dev->cnf));
+	in_dev->cnf.sysctl = NULL;
+	in_dev->dev = dev;
+	if ((in_dev->arp_parms = neigh_parms_alloc(dev, &arp_tbl)) == NULL)
+		goto out_kfree;
+	if (IPV4_DEVCONF(in_dev->cnf, FORWARDING))
+		dev_disable_lro(dev);
+	/* Reference in_dev->dev */
+	dev_hold(dev);
+	/* Account for reference dev->ip_ptr (below) */
+	in_dev_hold(in_dev);
+
+	devinet_sysctl_register(in_dev);
+	ip_mc_init_dev(in_dev);
+	if (dev->flags & IFF_UP)
+		ip_mc_up(in_dev);
+
+	/* we can receive as soon as ip_ptr is set -- do this last */
+	rcu_assign_pointer(dev->ip_ptr, in_dev);
+out:
+	return in_dev;
+out_kfree:
+	kfree(in_dev);
+	in_dev = NULL;
+	goto out;
+}
+
+static void in_dev_rcu_put(struct rcu_head *head)
+{
+	struct in_device *idev = container_of(head, struct in_device, rcu_head);
+	in_dev_put(idev);
+}
+
+static void inetdev_destroy(struct in_device *in_dev)
+{
+	struct in_ifaddr *ifa;
+	struct net_device *dev;
+
+	ASSERT_RTNL();
+
+	dev = in_dev->dev;
+
+	in_dev->dead = 1;
+
+	ip_mc_destroy_dev(in_dev);
+
+	while ((ifa = in_dev->ifa_list) != NULL) {
+		inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
+		inet_free_ifa(ifa);
+	}
+
+	dev->ip_ptr = NULL;
+
+	devinet_sysctl_unregister(in_dev);
+	neigh_parms_release(&arp_tbl, in_dev->arp_parms);
+	arp_ifdown(dev);
+
+	call_rcu(&in_dev->rcu_head, in_dev_rcu_put);
+}
+
+int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)
+{
+	rcu_read_lock();
+	for_primary_ifa(in_dev) {
+		if (inet_ifa_match(a, ifa)) {
+			if (!b || inet_ifa_match(b, ifa)) {
+				rcu_read_unlock();
+				return 1;
+			}
+		}
+	} endfor_ifa(in_dev);
+	rcu_read_unlock();
+	return 0;
+}
+
+static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
+			 int destroy, struct nlmsghdr *nlh, u32 pid)
+{
+	struct in_ifaddr *promote = NULL;
+	struct in_ifaddr *ifa, *ifa1 = *ifap;
+	struct in_ifaddr *last_prim = in_dev->ifa_list;
+	struct in_ifaddr *prev_prom = NULL;
+	int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
+
+	ASSERT_RTNL();
+
+	/* 1. Deleting primary ifaddr forces deletion all secondaries
+	 * unless alias promotion is set
+	 **/
+
+	if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
+		struct in_ifaddr **ifap1 = &ifa1->ifa_next;
+
+		while ((ifa = *ifap1) != NULL) {
+			if (!(ifa->ifa_flags & IFA_F_SECONDARY) &&
+			    ifa1->ifa_scope <= ifa->ifa_scope)
+				last_prim = ifa;
+
+			if (!(ifa->ifa_flags & IFA_F_SECONDARY) ||
+			    ifa1->ifa_mask != ifa->ifa_mask ||
+			    !inet_ifa_match(ifa1->ifa_address, ifa)) {
+				ifap1 = &ifa->ifa_next;
+				prev_prom = ifa;
+				continue;
+			}
+
+			if (!do_promote) {
+				*ifap1 = ifa->ifa_next;
+
+				rtmsg_ifa(RTM_DELADDR, ifa, nlh, pid);
+				blocking_notifier_call_chain(&inetaddr_chain,
+						NETDEV_DOWN, ifa);
+				inet_free_ifa(ifa);
+			} else {
+				promote = ifa;
+				break;
+			}
+		}
+	}
+
+	/* 2. Unlink it */
+
+	*ifap = ifa1->ifa_next;
+
+	/* 3. Announce address deletion */
+
+	/* Send message first, then call notifier.
+	   At first sight, FIB update triggered by notifier
+	   will refer to already deleted ifaddr, that could confuse
+	   netlink listeners. It is not true: look, gated sees
+	   that route deleted and if it still thinks that ifaddr
+	   is valid, it will try to restore deleted routes... Grr.
+	   So that, this order is correct.
+	 */
+	rtmsg_ifa(RTM_DELADDR, ifa1, nlh, pid);
+	blocking_notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa1);
+
+	if (promote) {
+
+		if (prev_prom) {
+			prev_prom->ifa_next = promote->ifa_next;
+			promote->ifa_next = last_prim->ifa_next;
+			last_prim->ifa_next = promote;
+		}
+
+		promote->ifa_flags &= ~IFA_F_SECONDARY;
+		rtmsg_ifa(RTM_NEWADDR, promote, nlh, pid);
+		blocking_notifier_call_chain(&inetaddr_chain,
+				NETDEV_UP, promote);
+		for (ifa = promote->ifa_next; ifa; ifa = ifa->ifa_next) {
+			if (ifa1->ifa_mask != ifa->ifa_mask ||
+			    !inet_ifa_match(ifa1->ifa_address, ifa))
+					continue;
+			fib_add_ifaddr(ifa);
+		}
+
+	}
+	if (destroy)
+		inet_free_ifa(ifa1);
+}
+
+static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
+			 int destroy)
+{
+	__inet_del_ifa(in_dev, ifap, destroy, NULL, 0);
+}
+
+static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
+			     u32 pid)
+{
+	struct in_device *in_dev = ifa->ifa_dev;
+	struct in_ifaddr *ifa1, **ifap, **last_primary;
+
+	ASSERT_RTNL();
+
+	if (!ifa->ifa_local) {
+		inet_free_ifa(ifa);
+		return 0;
+	}
+
+	ifa->ifa_flags &= ~IFA_F_SECONDARY;
+	last_primary = &in_dev->ifa_list;
+
+	for (ifap = &in_dev->ifa_list; (ifa1 = *ifap) != NULL;
+	     ifap = &ifa1->ifa_next) {
+		if (!(ifa1->ifa_flags & IFA_F_SECONDARY) &&
+		    ifa->ifa_scope <= ifa1->ifa_scope)
+			last_primary = &ifa1->ifa_next;
+		if (ifa1->ifa_mask == ifa->ifa_mask &&
+		    inet_ifa_match(ifa1->ifa_address, ifa)) {
+			if (ifa1->ifa_local == ifa->ifa_local) {
+				inet_free_ifa(ifa);
+				return -EEXIST;
+			}
+			if (ifa1->ifa_scope != ifa->ifa_scope) {
+				inet_free_ifa(ifa);
+				return -EINVAL;
+			}
+			ifa->ifa_flags |= IFA_F_SECONDARY;
+		}
+	}
+
+	if (!(ifa->ifa_flags & IFA_F_SECONDARY)) {
+		net_srandom(ifa->ifa_local);
+		ifap = last_primary;
+	}
+
+	ifa->ifa_next = *ifap;
+	*ifap = ifa;
+
+	/* Send message first, then call notifier.
+	   Notifier will trigger FIB update, so that
+	   listeners of netlink will know about new ifaddr */
+	rtmsg_ifa(RTM_NEWADDR, ifa, nlh, pid);
+	blocking_notifier_call_chain(&inetaddr_chain, NETDEV_UP, ifa);
+
+	return 0;
+}
+
+static int inet_insert_ifa(struct in_ifaddr *ifa)
+{
+	return __inet_insert_ifa(ifa, NULL, 0);
+}
+
+static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa)
+{
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
+
+	ASSERT_RTNL();
+
+	if (!in_dev) {
+		inet_free_ifa(ifa);
+		return -ENOBUFS;
+	}
+	ipv4_devconf_setall(in_dev);
+	if (ifa->ifa_dev != in_dev) {
+		WARN_ON(ifa->ifa_dev);
+		in_dev_hold(in_dev);
+		ifa->ifa_dev = in_dev;
+	}
+	if (ipv4_is_loopback(ifa->ifa_local))
+		ifa->ifa_scope = RT_SCOPE_HOST;
+	return inet_insert_ifa(ifa);
+}
+
+struct in_device *inetdev_by_index(struct net *net, int ifindex)
+{
+	struct net_device *dev;
+	struct in_device *in_dev = NULL;
+	read_lock(&dev_base_lock);
+	dev = __dev_get_by_index(net, ifindex);
+	if (dev)
+		in_dev = in_dev_get(dev);
+	read_unlock(&dev_base_lock);
+	return in_dev;
+}
+
+/* Called only from RTNL semaphored context. No locks. */
+
+struct in_ifaddr *inet_ifa_byprefix(struct in_device *in_dev, __be32 prefix,
+				    __be32 mask)
+{
+	ASSERT_RTNL();
+
+	for_primary_ifa(in_dev) {
+		if (ifa->ifa_mask == mask && inet_ifa_match(prefix, ifa))
+			return ifa;
+	} endfor_ifa(in_dev);
+	return NULL;
+}
+
+static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct nlattr *tb[IFA_MAX+1];
+	struct in_device *in_dev;
+	struct ifaddrmsg *ifm;
+	struct in_ifaddr *ifa, **ifap;
+	int err = -EINVAL;
+
+	ASSERT_RTNL();
+
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
+	if (err < 0)
+		goto errout;
+
+	ifm = nlmsg_data(nlh);
+	in_dev = inetdev_by_index(net, ifm->ifa_index);
+	if (in_dev == NULL) {
+		err = -ENODEV;
+		goto errout;
+	}
+
+	__in_dev_put(in_dev);
+
+	for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+	     ifap = &ifa->ifa_next) {
+		if (tb[IFA_LOCAL] &&
+		    ifa->ifa_local != nla_get_be32(tb[IFA_LOCAL]))
+			continue;
+
+		if (tb[IFA_LABEL] && nla_strcmp(tb[IFA_LABEL], ifa->ifa_label))
+			continue;
+
+		if (tb[IFA_ADDRESS] &&
+		    (ifm->ifa_prefixlen != ifa->ifa_prefixlen ||
+		    !inet_ifa_match(nla_get_be32(tb[IFA_ADDRESS]), ifa)))
+			continue;
+
+		__inet_del_ifa(in_dev, ifap, 1, nlh, NETLINK_CB(skb).pid);
+		return 0;
+	}
+
+	err = -EADDRNOTAVAIL;
+errout:
+	return err;
+}
+
+static struct in_ifaddr *rtm_to_ifaddr(struct net *net, struct nlmsghdr *nlh)
+{
+	struct nlattr *tb[IFA_MAX+1];
+	struct in_ifaddr *ifa;
+	struct ifaddrmsg *ifm;
+	struct net_device *dev;
+	struct in_device *in_dev;
+	int err;
+
+	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFA_MAX, ifa_ipv4_policy);
+	if (err < 0)
+		goto errout;
+
+	ifm = nlmsg_data(nlh);
+	err = -EINVAL;
+	if (ifm->ifa_prefixlen > 32 || tb[IFA_LOCAL] == NULL)
+		goto errout;
+
+	dev = __dev_get_by_index(net, ifm->ifa_index);
+	err = -ENODEV;
+	if (dev == NULL)
+		goto errout;
+
+	in_dev = __in_dev_get_rtnl(dev);
+	err = -ENOBUFS;
+	if (in_dev == NULL)
+		goto errout;
+
+	ifa = inet_alloc_ifa();
+	if (ifa == NULL)
+		/*
+		 * A potential indev allocation can be left alive, it stays
+		 * assigned to its device and is destroy with it.
+		 */
+		goto errout;
+
+	ipv4_devconf_setall(in_dev);
+	in_dev_hold(in_dev);
+
+	if (tb[IFA_ADDRESS] == NULL)
+		tb[IFA_ADDRESS] = tb[IFA_LOCAL];
+
+	ifa->ifa_prefixlen = ifm->ifa_prefixlen;
+	ifa->ifa_mask = inet_make_mask(ifm->ifa_prefixlen);
+	ifa->ifa_flags = ifm->ifa_flags;
+	ifa->ifa_scope = ifm->ifa_scope;
+	ifa->ifa_dev = in_dev;
+
+	ifa->ifa_local = nla_get_be32(tb[IFA_LOCAL]);
+	ifa->ifa_address = nla_get_be32(tb[IFA_ADDRESS]);
+
+	if (tb[IFA_BROADCAST])
+		ifa->ifa_broadcast = nla_get_be32(tb[IFA_BROADCAST]);
+
+	if (tb[IFA_LABEL])
+		nla_strlcpy(ifa->ifa_label, tb[IFA_LABEL], IFNAMSIZ);
+	else
+		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
+
+	return ifa;
+
+errout:
+	return ERR_PTR(err);
+}
+
+static int inet_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct in_ifaddr *ifa;
+
+	ASSERT_RTNL();
+
+	ifa = rtm_to_ifaddr(net, nlh);
+	if (IS_ERR(ifa))
+		return PTR_ERR(ifa);
+
+	return __inet_insert_ifa(ifa, nlh, NETLINK_CB(skb).pid);
+}
+
+/*
+ *	Determine a default network mask, based on the IP address.
+ */
+
+static __inline__ int inet_abc_len(__be32 addr)
+{
+	int rc = -1;	/* Something else, probably a multicast. */
+
+	if (ipv4_is_zeronet(addr))
+		rc = 0;
+	else {
+		__u32 haddr = ntohl(addr);
+
+		if (IN_CLASSA(haddr))
+			rc = 8;
+		else if (IN_CLASSB(haddr))
+			rc = 16;
+		else if (IN_CLASSC(haddr))
+			rc = 24;
+	}
+
+	return rc;
+}
+
+
+int devinet_ioctl(struct net *net, unsigned int cmd, void __user *arg)
+{
+	struct ifreq ifr;
+	struct sockaddr_in sin_orig;
+	struct sockaddr_in *sin = (struct sockaddr_in *)&ifr.ifr_addr;
+	struct in_device *in_dev;
+	struct in_ifaddr **ifap = NULL;
+	struct in_ifaddr *ifa = NULL;
+	struct net_device *dev;
+	char *colon;
+	int ret = -EFAULT;
+	int tryaddrmatch = 0;
+
+	/*
+	 *	Fetch the caller's info block into kernel space
+	 */
+
+	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
+		goto out;
+	ifr.ifr_name[IFNAMSIZ - 1] = 0;
+
+	/* save original address for comparison */
+	memcpy(&sin_orig, sin, sizeof(*sin));
+
+	colon = strchr(ifr.ifr_name, ':');
+	if (colon)
+		*colon = 0;
+
+	dev_load(net, ifr.ifr_name);
+
+	switch (cmd) {
+	case SIOCGIFADDR:	/* Get interface address */
+	case SIOCGIFBRDADDR:	/* Get the broadcast address */
+	case SIOCGIFDSTADDR:	/* Get the destination address */
+	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
+		/* Note that these ioctls will not sleep,
+		   so that we do not impose a lock.
+		   One day we will be forced to put shlock here (I mean SMP)
+		 */
+		tryaddrmatch = (sin_orig.sin_family == AF_INET);
+		memset(sin, 0, sizeof(*sin));
+		sin->sin_family = AF_INET;
+		break;
+
+	case SIOCSIFFLAGS:
+		ret = -EACCES;
+		if (!capable(CAP_NET_ADMIN))
+			goto out;
+		break;
+	case SIOCSIFADDR:	/* Set interface address (and family) */
+	case SIOCSIFBRDADDR:	/* Set the broadcast address */
+	case SIOCSIFDSTADDR:	/* Set the destination address */
+	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
+		ret = -EACCES;
+		if (!capable(CAP_NET_ADMIN))
+			goto out;
+		ret = -EINVAL;
+		if (sin->sin_family != AF_INET)
+			goto out;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	rtnl_lock();
+
+	ret = -ENODEV;
+	if ((dev = __dev_get_by_name(net, ifr.ifr_name)) == NULL)
+		goto done;
+
+	if (colon)
+		*colon = ':';
+
+	if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) {
+		if (tryaddrmatch) {
+			/* Matthias Andree */
+			/* compare label and address (4.4BSD style) */
+			/* note: we only do this for a limited set of ioctls
+			   and only if the original address family was AF_INET.
+			   This is checked above. */
+			for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+			     ifap = &ifa->ifa_next) {
+				if (!strcmp(ifr.ifr_name, ifa->ifa_label) &&
+				    sin_orig.sin_addr.s_addr ==
+							ifa->ifa_address) {
+					break; /* found */
+				}
+			}
+		}
+		/* we didn't get a match, maybe the application is
+		   4.3BSD-style and passed in junk so we fall back to
+		   comparing just the label */
+		if (!ifa) {
+			for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+			     ifap = &ifa->ifa_next)
+				if (!strcmp(ifr.ifr_name, ifa->ifa_label))
+					break;
+		}
+	}
+
+	ret = -EADDRNOTAVAIL;
+	if (!ifa && cmd != SIOCSIFADDR && cmd != SIOCSIFFLAGS)
+		goto done;
+
+	switch (cmd) {
+	case SIOCGIFADDR:	/* Get interface address */
+		sin->sin_addr.s_addr = ifa->ifa_local;
+		goto rarok;
+
+	case SIOCGIFBRDADDR:	/* Get the broadcast address */
+		sin->sin_addr.s_addr = ifa->ifa_broadcast;
+		goto rarok;
+
+	case SIOCGIFDSTADDR:	/* Get the destination address */
+		sin->sin_addr.s_addr = ifa->ifa_address;
+		goto rarok;
+
+	case SIOCGIFNETMASK:	/* Get the netmask for the interface */
+		sin->sin_addr.s_addr = ifa->ifa_mask;
+		goto rarok;
+
+	case SIOCSIFFLAGS:
+		if (colon) {
+			ret = -EADDRNOTAVAIL;
+			if (!ifa)
+				break;
+			ret = 0;
+			if (!(ifr.ifr_flags & IFF_UP))
+				inet_del_ifa(in_dev, ifap, 1);
+			break;
+		}
+		ret = dev_change_flags(dev, ifr.ifr_flags);
+		break;
+
+	case SIOCSIFADDR:	/* Set interface address (and family) */
+		ret = -EINVAL;
+		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
+			break;
+
+		if (!ifa) {
+			ret = -ENOBUFS;
+			if ((ifa = inet_alloc_ifa()) == NULL)
+				break;
+			if (colon)
+				memcpy(ifa->ifa_label, ifr.ifr_name, IFNAMSIZ);
+			else
+				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
+		} else {
+			ret = 0;
+			if (ifa->ifa_local == sin->sin_addr.s_addr)
+				break;
+			inet_del_ifa(in_dev, ifap, 0);
+			ifa->ifa_broadcast = 0;
+			ifa->ifa_scope = 0;
+		}
+
+		ifa->ifa_address = ifa->ifa_local = sin->sin_addr.s_addr;
+
+		if (!(dev->flags & IFF_POINTOPOINT)) {
+			ifa->ifa_prefixlen = inet_abc_len(ifa->ifa_address);
+			ifa->ifa_mask = inet_make_mask(ifa->ifa_prefixlen);
+			if ((dev->flags & IFF_BROADCAST) &&
+			    ifa->ifa_prefixlen < 31)
+				ifa->ifa_broadcast = ifa->ifa_address |
+						     ~ifa->ifa_mask;
+		} else {
+			ifa->ifa_prefixlen = 32;
+			ifa->ifa_mask = inet_make_mask(32);
+		}
+		ret = inet_set_ifa(dev, ifa);
+		break;
+
+	case SIOCSIFBRDADDR:	/* Set the broadcast address */
+		ret = 0;
+		if (ifa->ifa_broadcast != sin->sin_addr.s_addr) {
+			inet_del_ifa(in_dev, ifap, 0);
+			ifa->ifa_broadcast = sin->sin_addr.s_addr;
+			inet_insert_ifa(ifa);
+		}
+		break;
+
+	case SIOCSIFDSTADDR:	/* Set the destination address */
+		ret = 0;
+		if (ifa->ifa_address == sin->sin_addr.s_addr)
+			break;
+		ret = -EINVAL;
+		if (inet_abc_len(sin->sin_addr.s_addr) < 0)
+			break;
+		ret = 0;
+		inet_del_ifa(in_dev, ifap, 0);
+		ifa->ifa_address = sin->sin_addr.s_addr;
+		inet_insert_ifa(ifa);
+		break;
+
+	case SIOCSIFNETMASK: 	/* Set the netmask for the interface */
+
+		/*
+		 *	The mask we set must be legal.
+		 */
+		ret = -EINVAL;
+		if (bad_mask(sin->sin_addr.s_addr, 0))
+			break;
+		ret = 0;
+		if (ifa->ifa_mask != sin->sin_addr.s_addr) {
+			__be32 old_mask = ifa->ifa_mask;
+			inet_del_ifa(in_dev, ifap, 0);
+			ifa->ifa_mask = sin->sin_addr.s_addr;
+			ifa->ifa_prefixlen = inet_mask_len(ifa->ifa_mask);
+
+			/* See if current broadcast address matches
+			 * with current netmask, then recalculate
+			 * the broadcast address. Otherwise it's a
+			 * funny address, so don't touch it since
+			 * the user seems to know what (s)he's doing...
+			 */
+			if ((dev->flags & IFF_BROADCAST) &&
+			    (ifa->ifa_prefixlen < 31) &&
+			    (ifa->ifa_broadcast ==
+			     (ifa->ifa_local|~old_mask))) {
+				ifa->ifa_broadcast = (ifa->ifa_local |
+						      ~sin->sin_addr.s_addr);
+			}
+			inet_insert_ifa(ifa);
+		}
+		break;
+	}
+done:
+	rtnl_unlock();
+out:
+	return ret;
+rarok:
+	rtnl_unlock();
+	ret = copy_to_user(arg, &ifr, sizeof(struct ifreq)) ? -EFAULT : 0;
+	goto out;
+}
+
+static int inet_gifconf(struct net_device *dev, char __user *buf, int len)
+{
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
+	struct in_ifaddr *ifa;
+	struct ifreq ifr;
+	int done = 0;
+
+	if (!in_dev || (ifa = in_dev->ifa_list) == NULL)
+		goto out;
+
+	for (; ifa; ifa = ifa->ifa_next) {
+		if (!buf) {
+			done += sizeof(ifr);
+			continue;
+		}
+		if (len < (int) sizeof(ifr))
+			break;
+		memset(&ifr, 0, sizeof(struct ifreq));
+		if (ifa->ifa_label)
+			strcpy(ifr.ifr_name, ifa->ifa_label);
+		else
+			strcpy(ifr.ifr_name, dev->name);
+
+		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_family = AF_INET;
+		(*(struct sockaddr_in *)&ifr.ifr_addr).sin_addr.s_addr =
+								ifa->ifa_local;
+
+		if (copy_to_user(buf, &ifr, sizeof(struct ifreq))) {
+			done = -EFAULT;
+			break;
+		}
+		buf  += sizeof(struct ifreq);
+		len  -= sizeof(struct ifreq);
+		done += sizeof(struct ifreq);
+	}
+out:
+	return done;
+}
+
+__be32 inet_select_addr(const struct net_device *dev, __be32 dst, int scope)
+{
+	__be32 addr = 0;
+	struct in_device *in_dev;
+	struct net *net = dev_net(dev);
+
+	rcu_read_lock();
+	in_dev = __in_dev_get_rcu(dev);
+	if (!in_dev)
+		goto no_in_dev;
+
+	for_primary_ifa(in_dev) {
+		if (ifa->ifa_scope > scope)
+			continue;
+		if (!dst || inet_ifa_match(dst, ifa)) {
+			addr = ifa->ifa_local;
+			break;
+		}
+		if (!addr)
+			addr = ifa->ifa_local;
+	} endfor_ifa(in_dev);
+no_in_dev:
+	rcu_read_unlock();
+
+	if (addr)
+		goto out;
+
+	/* Not loopback addresses on loopback should be preferred
+	   in this case. It is importnat that lo is the first interface
+	   in dev_base list.
+	 */
+	read_lock(&dev_base_lock);
+	rcu_read_lock();
+	for_each_netdev(net, dev) {
+		if ((in_dev = __in_dev_get_rcu(dev)) == NULL)
+			continue;
+
+		for_primary_ifa(in_dev) {
+			if (ifa->ifa_scope != RT_SCOPE_LINK &&
+			    ifa->ifa_scope <= scope) {
+				addr = ifa->ifa_local;
+				goto out_unlock_both;
+			}
+		} endfor_ifa(in_dev);
+	}
+out_unlock_both:
+	read_unlock(&dev_base_lock);
+	rcu_read_unlock();
+out:
+	return addr;
+}
+
+static __be32 confirm_addr_indev(struct in_device *in_dev, __be32 dst,
+			      __be32 local, int scope)
+{
+	int same = 0;
+	__be32 addr = 0;
+
+	for_ifa(in_dev) {
+		if (!addr &&
+		    (local == ifa->ifa_local || !local) &&
+		    ifa->ifa_scope <= scope) {
+			addr = ifa->ifa_local;
+			if (same)
+				break;
+		}
+		if (!same) {
+			same = (!local || inet_ifa_match(local, ifa)) &&
+				(!dst || inet_ifa_match(dst, ifa));
+			if (same && addr) {
+				if (local || !dst)
+					break;
+				/* Is the selected addr into dst subnet? */
+				if (inet_ifa_match(addr, ifa))
+					break;
+				/* No, then can we use new local src? */
+				if (ifa->ifa_scope <= scope) {
+					addr = ifa->ifa_local;
+					break;
+				}
+				/* search for large dst subnet for addr */
+				same = 0;
+			}
+		}
+	} endfor_ifa(in_dev);
+
+	return same? addr : 0;
+}
+
+/*
+ * Confirm that local IP address exists using wildcards:
+ * - in_dev: only on this interface, 0=any interface
+ * - dst: only in the same subnet as dst, 0=any dst
+ * - local: address, 0=autoselect the local address
+ * - scope: maximum allowed scope value for the local address
+ */
+__be32 inet_confirm_addr(struct in_device *in_dev,
+			 __be32 dst, __be32 local, int scope)
+{
+	__be32 addr = 0;
+	struct net_device *dev;
+	struct net *net;
+
+	if (scope != RT_SCOPE_LINK)
+		return confirm_addr_indev(in_dev, dst, local, scope);
+
+	net = dev_net(in_dev->dev);
+	read_lock(&dev_base_lock);
+	rcu_read_lock();
+	for_each_netdev(net, dev) {
+		if ((in_dev = __in_dev_get_rcu(dev))) {
+			addr = confirm_addr_indev(in_dev, dst, local, scope);
+			if (addr)
+				break;
+		}
+	}
+	rcu_read_unlock();
+	read_unlock(&dev_base_lock);
+
+	return addr;
+}
+
+/*
+ *	Device notifier
+ */
+
+int register_inetaddr_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&inetaddr_chain, nb);
+}
+
+int unregister_inetaddr_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&inetaddr_chain, nb);
+}
+
+/* Rename ifa_labels for a device name change. Make some effort to preserve existing
+ * alias numbering and to create unique labels if possible.
+*/
+static void inetdev_changename(struct net_device *dev, struct in_device *in_dev)
+{
+	struct in_ifaddr *ifa;
+	int named = 0;
+
+	for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
+		char old[IFNAMSIZ], *dot;
+
+		memcpy(old, ifa->ifa_label, IFNAMSIZ);
+		memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
+		if (named++ == 0)
+			goto skip;
+		dot = strchr(old, ':');
+		if (dot == NULL) {
+			sprintf(old, ":%d", named);
+			dot = old;
+		}
+		if (strlen(dot) + strlen(dev->name) < IFNAMSIZ) {
+			strcat(ifa->ifa_label, dot);
+		} else {
+			strcpy(ifa->ifa_label + (IFNAMSIZ - strlen(dot) - 1), dot);
+		}
+skip:
+		rtmsg_ifa(RTM_NEWADDR, ifa, NULL, 0);
+	}
+}
+
+static inline bool inetdev_valid_mtu(unsigned mtu)
+{
+	return mtu >= 68;
+}
+
+/* Called only under RTNL semaphore */
+
+static int inetdev_event(struct notifier_block *this, unsigned long event,
+			 void *ptr)
+{
+	struct net_device *dev = ptr;
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
+
+	ASSERT_RTNL();
+
+	if (!in_dev) {
+		if (event == NETDEV_REGISTER) {
+			in_dev = inetdev_init(dev);
+			if (!in_dev)
+				return notifier_from_errno(-ENOMEM);
+			if (dev->flags & IFF_LOOPBACK) {
+				IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
+				IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
+			}
+		} else if (event == NETDEV_CHANGEMTU) {
+			/* Re-enabling IP */
+			if (inetdev_valid_mtu(dev->mtu))
+				in_dev = inetdev_init(dev);
+		}
+		goto out;
+	}
+
+	switch (event) {
+	case NETDEV_REGISTER:
+		printk(KERN_DEBUG "inetdev_event: bug\n");
+		dev->ip_ptr = NULL;
+		break;
+	case NETDEV_UP:
+		if (!inetdev_valid_mtu(dev->mtu))
+			break;
+		if (dev->flags & IFF_LOOPBACK) {
+			struct in_ifaddr *ifa;
+			if ((ifa = inet_alloc_ifa()) != NULL) {
+				ifa->ifa_local =
+				  ifa->ifa_address = htonl(INADDR_LOOPBACK);
+				ifa->ifa_prefixlen = 8;
+				ifa->ifa_mask = inet_make_mask(8);
+				in_dev_hold(in_dev);
+				ifa->ifa_dev = in_dev;
+				ifa->ifa_scope = RT_SCOPE_HOST;
+				memcpy(ifa->ifa_label, dev->name, IFNAMSIZ);
+				inet_insert_ifa(ifa);
+			}
+		}
+		ip_mc_up(in_dev);
+		break;
+	case NETDEV_DOWN:
+		ip_mc_down(in_dev);
+		break;
+	case NETDEV_CHANGEMTU:
+		if (inetdev_valid_mtu(dev->mtu))
+			break;
+		/* disable IP when MTU is not enough */
+	case NETDEV_UNREGISTER:
+		inetdev_destroy(in_dev);
+		break;
+	case NETDEV_CHANGENAME:
+		/* Do not notify about label change, this event is
+		 * not interesting to applications using netlink.
+		 */
+		inetdev_changename(dev, in_dev);
+
+		devinet_sysctl_unregister(in_dev);
+		devinet_sysctl_register(in_dev);
+		break;
+	}
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block ip_netdev_notifier = {
+	.notifier_call =inetdev_event,
+};
+
+static inline size_t inet_nlmsg_size(void)
+{
+	return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+	       + nla_total_size(4) /* IFA_ADDRESS */
+	       + nla_total_size(4) /* IFA_LOCAL */
+	       + nla_total_size(4) /* IFA_BROADCAST */
+	       + nla_total_size(IFNAMSIZ); /* IFA_LABEL */
+}
+
+static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
+			    u32 pid, u32 seq, int event, unsigned int flags)
+{
+	struct ifaddrmsg *ifm;
+	struct nlmsghdr  *nlh;
+
+	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*ifm), flags);
+	if (nlh == NULL)
+		return -EMSGSIZE;
+
+	ifm = nlmsg_data(nlh);
+	ifm->ifa_family = AF_INET;
+	ifm->ifa_prefixlen = ifa->ifa_prefixlen;
+	ifm->ifa_flags = ifa->ifa_flags|IFA_F_PERMANENT;
+	ifm->ifa_scope = ifa->ifa_scope;
+	ifm->ifa_index = ifa->ifa_dev->dev->ifindex;
+
+	if (ifa->ifa_address)
+		NLA_PUT_BE32(skb, IFA_ADDRESS, ifa->ifa_address);
+
+	if (ifa->ifa_local)
+		NLA_PUT_BE32(skb, IFA_LOCAL, ifa->ifa_local);
+
+	if (ifa->ifa_broadcast)
+		NLA_PUT_BE32(skb, IFA_BROADCAST, ifa->ifa_broadcast);
+
+	if (ifa->ifa_label[0])
+		NLA_PUT_STRING(skb, IFA_LABEL, ifa->ifa_label);
+
+	return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	int idx, ip_idx;
+	struct net_device *dev;
+	struct in_device *in_dev;
+	struct in_ifaddr *ifa;
+	int s_ip_idx, s_idx = cb->args[0];
+
+	s_ip_idx = ip_idx = cb->args[1];
+	idx = 0;
+	for_each_netdev(net, dev) {
+		if (idx < s_idx)
+			goto cont;
+		if (idx > s_idx)
+			s_ip_idx = 0;
+		if ((in_dev = __in_dev_get_rtnl(dev)) == NULL)
+			goto cont;
+
+		for (ifa = in_dev->ifa_list, ip_idx = 0; ifa;
+		     ifa = ifa->ifa_next, ip_idx++) {
+			if (ip_idx < s_ip_idx)
+				continue;
+			if (inet_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
+					     cb->nlh->nlmsg_seq,
+					     RTM_NEWADDR, NLM_F_MULTI) <= 0)
+				goto done;
+		}
+cont:
+		idx++;
+	}
+
+done:
+	cb->args[0] = idx;
+	cb->args[1] = ip_idx;
+
+	return skb->len;
+}
+
+static void rtmsg_ifa(int event, struct in_ifaddr* ifa, struct nlmsghdr *nlh,
+		      u32 pid)
+{
+	struct sk_buff *skb;
+	u32 seq = nlh ? nlh->nlmsg_seq : 0;
+	int err = -ENOBUFS;
+	struct net *net;
+
+	net = dev_net(ifa->ifa_dev->dev);
+	skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
+	if (skb == NULL)
+		goto errout;
+
+	err = inet_fill_ifaddr(skb, ifa, pid, seq, event, 0);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in inet_nlmsg_size() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+	err = rtnl_notify(skb, net, pid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(net, RTNLGRP_IPV4_IFADDR, err);
+}
+
+#ifdef CONFIG_SYSCTL
+
+static void devinet_copy_dflt_conf(struct net *net, int i)
+{
+	struct net_device *dev;
+
+	read_lock(&dev_base_lock);
+	for_each_netdev(net, dev) {
+		struct in_device *in_dev;
+		rcu_read_lock();
+		in_dev = __in_dev_get_rcu(dev);
+		if (in_dev && !test_bit(i, in_dev->cnf.state))
+			in_dev->cnf.data[i] = net->ipv4.devconf_dflt->data[i];
+		rcu_read_unlock();
+	}
+	read_unlock(&dev_base_lock);
+}
+
+static void inet_forward_change(struct net *net)
+{
+	struct net_device *dev;
+	int on = IPV4_DEVCONF_ALL(net, FORWARDING);
+
+	IPV4_DEVCONF_ALL(net, ACCEPT_REDIRECTS) = !on;
+	IPV4_DEVCONF_DFLT(net, FORWARDING) = on;
+
+	read_lock(&dev_base_lock);
+	for_each_netdev(net, dev) {
+		struct in_device *in_dev;
+		if (on)
+			dev_disable_lro(dev);
+		rcu_read_lock();
+		in_dev = __in_dev_get_rcu(dev);
+		if (in_dev)
+			IN_DEV_CONF_SET(in_dev, FORWARDING, on);
+		rcu_read_unlock();
+	}
+	read_unlock(&dev_base_lock);
+}
+
+static int devinet_conf_proc(ctl_table *ctl, int write,
+			     struct file* filp, void __user *buffer,
+			     size_t *lenp, loff_t *ppos)
+{
+	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+
+	if (write) {
+		struct ipv4_devconf *cnf = ctl->extra1;
+		struct net *net = ctl->extra2;
+		int i = (int *)ctl->data - cnf->data;
+
+		set_bit(i, cnf->state);
+
+		if (cnf == net->ipv4.devconf_dflt)
+			devinet_copy_dflt_conf(net, i);
+	}
+
+	return ret;
+}
+
+static int devinet_conf_sysctl(ctl_table *table,
+			       void __user *oldval, size_t __user *oldlenp,
+			       void __user *newval, size_t newlen)
+{
+	struct ipv4_devconf *cnf;
+	struct net *net;
+	int *valp = table->data;
+	int new;
+	int i;
+
+	if (!newval || !newlen)
+		return 0;
+
+	if (newlen != sizeof(int))
+		return -EINVAL;
+
+	if (get_user(new, (int __user *)newval))
+		return -EFAULT;
+
+	if (new == *valp)
+		return 0;
+
+	if (oldval && oldlenp) {
+		size_t len;
+
+		if (get_user(len, oldlenp))
+			return -EFAULT;
+
+		if (len) {
+			if (len > table->maxlen)
+				len = table->maxlen;
+			if (copy_to_user(oldval, valp, len))
+				return -EFAULT;
+			if (put_user(len, oldlenp))
+				return -EFAULT;
+		}
+	}
+
+	*valp = new;
+
+	cnf = table->extra1;
+	net = table->extra2;
+	i = (int *)table->data - cnf->data;
+
+	set_bit(i, cnf->state);
+
+	if (cnf == net->ipv4.devconf_dflt)
+		devinet_copy_dflt_conf(net, i);
+
+	return 1;
+}
+
+static int devinet_sysctl_forward(ctl_table *ctl, int write,
+				  struct file* filp, void __user *buffer,
+				  size_t *lenp, loff_t *ppos)
+{
+	int *valp = ctl->data;
+	int val = *valp;
+	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+
+	if (write && *valp != val) {
+		struct net *net = ctl->extra2;
+
+		if (valp != &IPV4_DEVCONF_DFLT(net, FORWARDING)) {
+			rtnl_lock();
+			if (valp == &IPV4_DEVCONF_ALL(net, FORWARDING)) {
+				inet_forward_change(net);
+			} else if (*valp) {
+				struct ipv4_devconf *cnf = ctl->extra1;
+				struct in_device *idev =
+					container_of(cnf, struct in_device, cnf);
+				dev_disable_lro(idev->dev);
+			}
+			rtnl_unlock();
+			rt_cache_flush(net, 0);
+		}
+	}
+
+	return ret;
+}
+
+int ipv4_doint_and_flush(ctl_table *ctl, int write,
+			 struct file* filp, void __user *buffer,
+			 size_t *lenp, loff_t *ppos)
+{
+	int *valp = ctl->data;
+	int val = *valp;
+	int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
+	struct net *net = ctl->extra2;
+
+	if (write && *valp != val)
+		rt_cache_flush(net, 0);
+
+	return ret;
+}
+
+int ipv4_doint_and_flush_strategy(ctl_table *table,
+				  void __user *oldval, size_t __user *oldlenp,
+				  void __user *newval, size_t newlen)
+{
+	int ret = devinet_conf_sysctl(table, oldval, oldlenp, newval, newlen);
+	struct net *net = table->extra2;
+
+	if (ret == 1)
+		rt_cache_flush(net, 0);
+
+	return ret;
+}
+
+
+#define DEVINET_SYSCTL_ENTRY(attr, name, mval, proc, sysctl) \
+	{ \
+		.ctl_name	= NET_IPV4_CONF_ ## attr, \
+		.procname	= name, \
+		.data		= ipv4_devconf.data + \
+				  NET_IPV4_CONF_ ## attr - 1, \
+		.maxlen		= sizeof(int), \
+		.mode		= mval, \
+		.proc_handler	= proc, \
+		.strategy	= sysctl, \
+		.extra1		= &ipv4_devconf, \
+	}
+
+#define DEVINET_SYSCTL_RW_ENTRY(attr, name) \
+	DEVINET_SYSCTL_ENTRY(attr, name, 0644, devinet_conf_proc, \
+			     devinet_conf_sysctl)
+
+#define DEVINET_SYSCTL_RO_ENTRY(attr, name) \
+	DEVINET_SYSCTL_ENTRY(attr, name, 0444, devinet_conf_proc, \
+			     devinet_conf_sysctl)
+
+#define DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, proc, sysctl) \
+	DEVINET_SYSCTL_ENTRY(attr, name, 0644, proc, sysctl)
+
+#define DEVINET_SYSCTL_FLUSHING_ENTRY(attr, name) \
+	DEVINET_SYSCTL_COMPLEX_ENTRY(attr, name, ipv4_doint_and_flush, \
+				     ipv4_doint_and_flush_strategy)
+
+static struct devinet_sysctl_table {
+	struct ctl_table_header *sysctl_header;
+	struct ctl_table devinet_vars[__NET_IPV4_CONF_MAX];
+	char *dev_name;
+} devinet_sysctl = {
+	.devinet_vars = {
+		DEVINET_SYSCTL_COMPLEX_ENTRY(FORWARDING, "forwarding",
+					     devinet_sysctl_forward,
+					     devinet_conf_sysctl),
+		DEVINET_SYSCTL_RO_ENTRY(MC_FORWARDING, "mc_forwarding"),
+
+		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_REDIRECTS, "accept_redirects"),
+		DEVINET_SYSCTL_RW_ENTRY(SECURE_REDIRECTS, "secure_redirects"),
+		DEVINET_SYSCTL_RW_ENTRY(SHARED_MEDIA, "shared_media"),
+		DEVINET_SYSCTL_RW_ENTRY(RP_FILTER, "rp_filter"),
+		DEVINET_SYSCTL_RW_ENTRY(SEND_REDIRECTS, "send_redirects"),
+		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
+					"accept_source_route"),
+		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
+		DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
+		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
+		DEVINET_SYSCTL_RW_ENTRY(LOG_MARTIANS, "log_martians"),
+		DEVINET_SYSCTL_RW_ENTRY(TAG, "tag"),
+		DEVINET_SYSCTL_RW_ENTRY(ARPFILTER, "arp_filter"),
+		DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"),
+		DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"),
+		DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"),
+
+		DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"),
+		DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),
+		DEVINET_SYSCTL_FLUSHING_ENTRY(FORCE_IGMP_VERSION,
+					      "force_igmp_version"),
+		DEVINET_SYSCTL_FLUSHING_ENTRY(PROMOTE_SECONDARIES,
+					      "promote_secondaries"),
+	},
+};
+
+static int __devinet_sysctl_register(struct net *net, char *dev_name,
+		int ctl_name, struct ipv4_devconf *p)
+{
+	int i;
+	struct devinet_sysctl_table *t;
+
+#define DEVINET_CTL_PATH_DEV	3
+
+	struct ctl_path devinet_ctl_path[] = {
+		{ .procname = "net", .ctl_name = CTL_NET, },
+		{ .procname = "ipv4", .ctl_name = NET_IPV4, },
+		{ .procname = "conf", .ctl_name = NET_IPV4_CONF, },
+		{ /* to be set */ },
+		{ },
+	};
+
+	t = kmemdup(&devinet_sysctl, sizeof(*t), GFP_KERNEL);
+	if (!t)
+		goto out;
+
+	for (i = 0; i < ARRAY_SIZE(t->devinet_vars) - 1; i++) {
+		t->devinet_vars[i].data += (char *)p - (char *)&ipv4_devconf;
+		t->devinet_vars[i].extra1 = p;
+		t->devinet_vars[i].extra2 = net;
+	}
+
+	/*
+	 * Make a copy of dev_name, because '.procname' is regarded as const
+	 * by sysctl and we wouldn't want anyone to change it under our feet
+	 * (see SIOCSIFNAME).
+	 */
+	t->dev_name = kstrdup(dev_name, GFP_KERNEL);
+	if (!t->dev_name)
+		goto free;
+
+	devinet_ctl_path[DEVINET_CTL_PATH_DEV].procname = t->dev_name;
+	devinet_ctl_path[DEVINET_CTL_PATH_DEV].ctl_name = ctl_name;
+
+	t->sysctl_header = register_net_sysctl_table(net, devinet_ctl_path,
+			t->devinet_vars);
+	if (!t->sysctl_header)
+		goto free_procname;
+
+	p->sysctl = t;
+	return 0;
+
+free_procname:
+	kfree(t->dev_name);
+free:
+	kfree(t);
+out:
+	return -ENOBUFS;
+}
+
+static void __devinet_sysctl_unregister(struct ipv4_devconf *cnf)
+{
+	struct devinet_sysctl_table *t = cnf->sysctl;
+
+	if (t == NULL)
+		return;
+
+	cnf->sysctl = NULL;
+	unregister_sysctl_table(t->sysctl_header);
+	kfree(t->dev_name);
+	kfree(t);
+}
+
+static void devinet_sysctl_register(struct in_device *idev)
+{
+	neigh_sysctl_register(idev->dev, idev->arp_parms, NET_IPV4,
+			NET_IPV4_NEIGH, "ipv4", NULL, NULL);
+	__devinet_sysctl_register(dev_net(idev->dev), idev->dev->name,
+			idev->dev->ifindex, &idev->cnf);
+}
+
+static void devinet_sysctl_unregister(struct in_device *idev)
+{
+	__devinet_sysctl_unregister(&idev->cnf);
+	neigh_sysctl_unregister(idev->arp_parms);
+}
+
+static struct ctl_table ctl_forward_entry[] = {
+	{
+		.ctl_name	= NET_IPV4_FORWARD,
+		.procname	= "ip_forward",
+		.data		= &ipv4_devconf.data[
+					NET_IPV4_CONF_FORWARDING - 1],
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= devinet_sysctl_forward,
+		.strategy	= devinet_conf_sysctl,
+		.extra1		= &ipv4_devconf,
+		.extra2		= &init_net,
+	},
+	{ },
+};
+
+static __net_initdata struct ctl_path net_ipv4_path[] = {
+	{ .procname = "net", .ctl_name = CTL_NET, },
+	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
+	{ },
+};
+#endif
+
+static __net_init int devinet_init_net(struct net *net)
+{
+	int err;
+	struct ipv4_devconf *all, *dflt;
+#ifdef CONFIG_SYSCTL
+	struct ctl_table *tbl = ctl_forward_entry;
+	struct ctl_table_header *forw_hdr;
+#endif
+
+	err = -ENOMEM;
+	all = &ipv4_devconf;
+	dflt = &ipv4_devconf_dflt;
+
+	if (net != &init_net) {
+		all = kmemdup(all, sizeof(ipv4_devconf), GFP_KERNEL);
+		if (all == NULL)
+			goto err_alloc_all;
+
+		dflt = kmemdup(dflt, sizeof(ipv4_devconf_dflt), GFP_KERNEL);
+		if (dflt == NULL)
+			goto err_alloc_dflt;
+
+#ifdef CONFIG_SYSCTL
+		tbl = kmemdup(tbl, sizeof(ctl_forward_entry), GFP_KERNEL);
+		if (tbl == NULL)
+			goto err_alloc_ctl;
+
+		tbl[0].data = &all->data[NET_IPV4_CONF_FORWARDING - 1];
+		tbl[0].extra1 = all;
+		tbl[0].extra2 = net;
+#endif
+	}
+
+#ifdef CONFIG_SYSCTL
+	err = __devinet_sysctl_register(net, "all",
+			NET_PROTO_CONF_ALL, all);
+	if (err < 0)
+		goto err_reg_all;
+
+	err = __devinet_sysctl_register(net, "default",
+			NET_PROTO_CONF_DEFAULT, dflt);
+	if (err < 0)
+		goto err_reg_dflt;
+
+	err = -ENOMEM;
+	forw_hdr = register_net_sysctl_table(net, net_ipv4_path, tbl);
+	if (forw_hdr == NULL)
+		goto err_reg_ctl;
+	net->ipv4.forw_hdr = forw_hdr;
+#endif
+
+	net->ipv4.devconf_all = all;
+	net->ipv4.devconf_dflt = dflt;
+	return 0;
+
+#ifdef CONFIG_SYSCTL
+err_reg_ctl:
+	__devinet_sysctl_unregister(dflt);
+err_reg_dflt:
+	__devinet_sysctl_unregister(all);
+err_reg_all:
+	if (tbl != ctl_forward_entry)
+		kfree(tbl);
+err_alloc_ctl:
+#endif
+	if (dflt != &ipv4_devconf_dflt)
+		kfree(dflt);
+err_alloc_dflt:
+	if (all != &ipv4_devconf)
+		kfree(all);
+err_alloc_all:
+	return err;
+}
+
+static __net_exit void devinet_exit_net(struct net *net)
+{
+#ifdef CONFIG_SYSCTL
+	struct ctl_table *tbl;
+
+	tbl = net->ipv4.forw_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->ipv4.forw_hdr);
+	__devinet_sysctl_unregister(net->ipv4.devconf_dflt);
+	__devinet_sysctl_unregister(net->ipv4.devconf_all);
+	kfree(tbl);
+#endif
+	kfree(net->ipv4.devconf_dflt);
+	kfree(net->ipv4.devconf_all);
+}
+
+static __net_initdata struct pernet_operations devinet_ops = {
+	.init = devinet_init_net,
+	.exit = devinet_exit_net,
+};
+
+void __init devinet_init(void)
+{
+	register_pernet_subsys(&devinet_ops);
+
+	register_gifconf(PF_INET, inet_gifconf);
+	register_netdevice_notifier(&ip_netdev_notifier);
+
+	rtnl_register(PF_INET, RTM_NEWADDR, inet_rtm_newaddr, NULL);
+	rtnl_register(PF_INET, RTM_DELADDR, inet_rtm_deladdr, NULL);
+	rtnl_register(PF_INET, RTM_GETADDR, NULL, inet_dump_ifaddr);
+}
+
+EXPORT_SYMBOL(in_dev_finish_destroy);
+EXPORT_SYMBOL(inet_select_addr);
+EXPORT_SYMBOL(inetdev_by_index);
+EXPORT_SYMBOL(register_inetaddr_notifier);
+EXPORT_SYMBOL(unregister_inetaddr_notifier);
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
new file mode 100644
index 0000000..21515d4
--- /dev/null
+++ b/net/ipv4/esp4.c
@@ -0,0 +1,648 @@
+#include <crypto/aead.h>
+#include <crypto/authenc.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/esp.h>
+#include <linux/scatterlist.h>
+#include <linux/kernel.h>
+#include <linux/pfkeyv2.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/in6.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/udp.h>
+
+struct esp_skb_cb {
+	struct xfrm_skb_cb xfrm;
+	void *tmp;
+};
+
+#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
+
+/*
+ * Allocate an AEAD request structure with extra space for SG and IV.
+ *
+ * For alignment considerations the IV is placed at the front, followed
+ * by the request and finally the SG list.
+ *
+ * TODO: Use spare space in skb for this where possible.
+ */
+static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags)
+{
+	unsigned int len;
+
+	len = crypto_aead_ivsize(aead);
+	if (len) {
+		len += crypto_aead_alignmask(aead) &
+		       ~(crypto_tfm_ctx_alignment() - 1);
+		len = ALIGN(len, crypto_tfm_ctx_alignment());
+	}
+
+	len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
+	len = ALIGN(len, __alignof__(struct scatterlist));
+
+	len += sizeof(struct scatterlist) * nfrags;
+
+	return kmalloc(len, GFP_ATOMIC);
+}
+
+static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp)
+{
+	return crypto_aead_ivsize(aead) ?
+	       PTR_ALIGN((u8 *)tmp, crypto_aead_alignmask(aead) + 1) : tmp;
+}
+
+static inline struct aead_givcrypt_request *esp_tmp_givreq(
+	struct crypto_aead *aead, u8 *iv)
+{
+	struct aead_givcrypt_request *req;
+
+	req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
+				crypto_tfm_ctx_alignment());
+	aead_givcrypt_set_tfm(req, aead);
+	return req;
+}
+
+static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
+{
+	struct aead_request *req;
+
+	req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
+				crypto_tfm_ctx_alignment());
+	aead_request_set_tfm(req, aead);
+	return req;
+}
+
+static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
+					     struct aead_request *req)
+{
+	return (void *)ALIGN((unsigned long)(req + 1) +
+			     crypto_aead_reqsize(aead),
+			     __alignof__(struct scatterlist));
+}
+
+static inline struct scatterlist *esp_givreq_sg(
+	struct crypto_aead *aead, struct aead_givcrypt_request *req)
+{
+	return (void *)ALIGN((unsigned long)(req + 1) +
+			     crypto_aead_reqsize(aead),
+			     __alignof__(struct scatterlist));
+}
+
+static void esp_output_done(struct crypto_async_request *base, int err)
+{
+	struct sk_buff *skb = base->data;
+
+	kfree(ESP_SKB_CB(skb)->tmp);
+	xfrm_output_resume(skb, err);
+}
+
+static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int err;
+	struct ip_esp_hdr *esph;
+	struct crypto_aead *aead;
+	struct aead_givcrypt_request *req;
+	struct scatterlist *sg;
+	struct scatterlist *asg;
+	struct esp_data *esp;
+	struct sk_buff *trailer;
+	void *tmp;
+	u8 *iv;
+	u8 *tail;
+	int blksize;
+	int clen;
+	int alen;
+	int nfrags;
+
+	/* skb is pure payload to encrypt */
+
+	err = -ENOMEM;
+
+	/* Round to block size */
+	clen = skb->len;
+
+	esp = x->data;
+	aead = esp->aead;
+	alen = crypto_aead_authsize(aead);
+
+	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
+	clen = ALIGN(clen + 2, blksize);
+	if (esp->padlen)
+		clen = ALIGN(clen, esp->padlen);
+
+	if ((err = skb_cow_data(skb, clen - skb->len + alen, &trailer)) < 0)
+		goto error;
+	nfrags = err;
+
+	tmp = esp_alloc_tmp(aead, nfrags + 1);
+	if (!tmp)
+		goto error;
+
+	iv = esp_tmp_iv(aead, tmp);
+	req = esp_tmp_givreq(aead, iv);
+	asg = esp_givreq_sg(aead, req);
+	sg = asg + 1;
+
+	/* Fill padding... */
+	tail = skb_tail_pointer(trailer);
+	do {
+		int i;
+		for (i=0; i<clen-skb->len - 2; i++)
+			tail[i] = i + 1;
+	} while (0);
+	tail[clen - skb->len - 2] = (clen - skb->len) - 2;
+	tail[clen - skb->len - 1] = *skb_mac_header(skb);
+	pskb_put(skb, trailer, clen - skb->len + alen);
+
+	skb_push(skb, -skb_network_offset(skb));
+	esph = ip_esp_hdr(skb);
+	*skb_mac_header(skb) = IPPROTO_ESP;
+
+	/* this is non-NULL only with UDP Encapsulation */
+	if (x->encap) {
+		struct xfrm_encap_tmpl *encap = x->encap;
+		struct udphdr *uh;
+		__be32 *udpdata32;
+		__be16 sport, dport;
+		int encap_type;
+
+		spin_lock_bh(&x->lock);
+		sport = encap->encap_sport;
+		dport = encap->encap_dport;
+		encap_type = encap->encap_type;
+		spin_unlock_bh(&x->lock);
+
+		uh = (struct udphdr *)esph;
+		uh->source = sport;
+		uh->dest = dport;
+		uh->len = htons(skb->len - skb_transport_offset(skb));
+		uh->check = 0;
+
+		switch (encap_type) {
+		default:
+		case UDP_ENCAP_ESPINUDP:
+			esph = (struct ip_esp_hdr *)(uh + 1);
+			break;
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			udpdata32 = (__be32 *)(uh + 1);
+			udpdata32[0] = udpdata32[1] = 0;
+			esph = (struct ip_esp_hdr *)(udpdata32 + 2);
+			break;
+		}
+
+		*skb_mac_header(skb) = IPPROTO_UDP;
+	}
+
+	esph->spi = x->id.spi;
+	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
+
+	sg_init_table(sg, nfrags);
+	skb_to_sgvec(skb, sg,
+		     esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
+		     clen + alen);
+	sg_init_one(asg, esph, sizeof(*esph));
+
+	aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
+	aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
+	aead_givcrypt_set_assoc(req, asg, sizeof(*esph));
+	aead_givcrypt_set_giv(req, esph->enc_data,
+			      XFRM_SKB_CB(skb)->seq.output);
+
+	ESP_SKB_CB(skb)->tmp = tmp;
+	err = crypto_aead_givencrypt(req);
+	if (err == -EINPROGRESS)
+		goto error;
+
+	if (err == -EBUSY)
+		err = NET_XMIT_DROP;
+
+	kfree(tmp);
+
+error:
+	return err;
+}
+
+static int esp_input_done2(struct sk_buff *skb, int err)
+{
+	struct iphdr *iph;
+	struct xfrm_state *x = xfrm_input_state(skb);
+	struct esp_data *esp = x->data;
+	struct crypto_aead *aead = esp->aead;
+	int alen = crypto_aead_authsize(aead);
+	int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
+	int elen = skb->len - hlen;
+	int ihl;
+	u8 nexthdr[2];
+	int padlen;
+
+	kfree(ESP_SKB_CB(skb)->tmp);
+
+	if (unlikely(err))
+		goto out;
+
+	if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
+		BUG();
+
+	err = -EINVAL;
+	padlen = nexthdr[0];
+	if (padlen + 2 + alen >= elen)
+		goto out;
+
+	/* ... check padding bits here. Silly. :-) */
+
+	iph = ip_hdr(skb);
+	ihl = iph->ihl * 4;
+
+	if (x->encap) {
+		struct xfrm_encap_tmpl *encap = x->encap;
+		struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
+
+		/*
+		 * 1) if the NAT-T peer's IP or port changed then
+		 *    advertize the change to the keying daemon.
+		 *    This is an inbound SA, so just compare
+		 *    SRC ports.
+		 */
+		if (iph->saddr != x->props.saddr.a4 ||
+		    uh->source != encap->encap_sport) {
+			xfrm_address_t ipaddr;
+
+			ipaddr.a4 = iph->saddr;
+			km_new_mapping(x, &ipaddr, uh->source);
+
+			/* XXX: perhaps add an extra
+			 * policy check here, to see
+			 * if we should allow or
+			 * reject a packet from a
+			 * different source
+			 * address/port.
+			 */
+		}
+
+		/*
+		 * 2) ignore UDP/TCP checksums in case
+		 *    of NAT-T in Transport Mode, or
+		 *    perform other post-processing fixes
+		 *    as per draft-ietf-ipsec-udp-encaps-06,
+		 *    section 3.1.2
+		 */
+		if (x->props.mode == XFRM_MODE_TRANSPORT)
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+
+	pskb_trim(skb, skb->len - alen - padlen - 2);
+	__skb_pull(skb, hlen);
+	skb_set_transport_header(skb, -ihl);
+
+	err = nexthdr[1];
+
+	/* RFC4303: Drop dummy packets without any error */
+	if (err == IPPROTO_NONE)
+		err = -EINVAL;
+
+out:
+	return err;
+}
+
+static void esp_input_done(struct crypto_async_request *base, int err)
+{
+	struct sk_buff *skb = base->data;
+
+	xfrm_input_resume(skb, esp_input_done2(skb, err));
+}
+
+/*
+ * Note: detecting truncated vs. non-truncated authentication data is very
+ * expensive, so we only support truncated data, which is the recommended
+ * and common case.
+ */
+static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct ip_esp_hdr *esph;
+	struct esp_data *esp = x->data;
+	struct crypto_aead *aead = esp->aead;
+	struct aead_request *req;
+	struct sk_buff *trailer;
+	int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
+	int nfrags;
+	void *tmp;
+	u8 *iv;
+	struct scatterlist *sg;
+	struct scatterlist *asg;
+	int err = -EINVAL;
+
+	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
+		goto out;
+
+	if (elen <= 0)
+		goto out;
+
+	if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
+		goto out;
+	nfrags = err;
+
+	err = -ENOMEM;
+	tmp = esp_alloc_tmp(aead, nfrags + 1);
+	if (!tmp)
+		goto out;
+
+	ESP_SKB_CB(skb)->tmp = tmp;
+	iv = esp_tmp_iv(aead, tmp);
+	req = esp_tmp_req(aead, iv);
+	asg = esp_req_sg(aead, req);
+	sg = asg + 1;
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	esph = (struct ip_esp_hdr *)skb->data;
+
+	/* Get ivec. This can be wrong, check against another impls. */
+	iv = esph->enc_data;
+
+	sg_init_table(sg, nfrags);
+	skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
+	sg_init_one(asg, esph, sizeof(*esph));
+
+	aead_request_set_callback(req, 0, esp_input_done, skb);
+	aead_request_set_crypt(req, sg, sg, elen, iv);
+	aead_request_set_assoc(req, asg, sizeof(*esph));
+
+	err = crypto_aead_decrypt(req);
+	if (err == -EINPROGRESS)
+		goto out;
+
+	err = esp_input_done2(skb, err);
+
+out:
+	return err;
+}
+
+static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
+{
+	struct esp_data *esp = x->data;
+	u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
+	u32 align = max_t(u32, blksize, esp->padlen);
+	u32 rem;
+
+	mtu -= x->props.header_len + crypto_aead_authsize(esp->aead);
+	rem = mtu & (align - 1);
+	mtu &= ~(align - 1);
+
+	switch (x->props.mode) {
+	case XFRM_MODE_TUNNEL:
+		break;
+	default:
+	case XFRM_MODE_TRANSPORT:
+		/* The worst case */
+		mtu -= blksize - 4;
+		mtu += min_t(u32, blksize - 4, rem);
+		break;
+	case XFRM_MODE_BEET:
+		/* The worst case. */
+		mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
+		break;
+	}
+
+	return mtu - 2;
+}
+
+static void esp4_err(struct sk_buff *skb, u32 info)
+{
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	struct ip_esp_hdr *esph = (struct ip_esp_hdr*)(skb->data+(iph->ihl<<2));
+	struct xfrm_state *x;
+
+	if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
+	    icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+		return;
+
+	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET);
+	if (!x)
+		return;
+	NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
+		 ntohl(esph->spi), ntohl(iph->daddr));
+	xfrm_state_put(x);
+}
+
+static void esp_destroy(struct xfrm_state *x)
+{
+	struct esp_data *esp = x->data;
+
+	if (!esp)
+		return;
+
+	crypto_free_aead(esp->aead);
+	kfree(esp);
+}
+
+static int esp_init_aead(struct xfrm_state *x)
+{
+	struct esp_data *esp = x->data;
+	struct crypto_aead *aead;
+	int err;
+
+	aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
+	err = PTR_ERR(aead);
+	if (IS_ERR(aead))
+		goto error;
+
+	esp->aead = aead;
+
+	err = crypto_aead_setkey(aead, x->aead->alg_key,
+				 (x->aead->alg_key_len + 7) / 8);
+	if (err)
+		goto error;
+
+	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
+	if (err)
+		goto error;
+
+error:
+	return err;
+}
+
+static int esp_init_authenc(struct xfrm_state *x)
+{
+	struct esp_data *esp = x->data;
+	struct crypto_aead *aead;
+	struct crypto_authenc_key_param *param;
+	struct rtattr *rta;
+	char *key;
+	char *p;
+	char authenc_name[CRYPTO_MAX_ALG_NAME];
+	unsigned int keylen;
+	int err;
+
+	err = -EINVAL;
+	if (x->ealg == NULL)
+		goto error;
+
+	err = -ENAMETOOLONG;
+	if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "authenc(%s,%s)",
+		     x->aalg ? x->aalg->alg_name : "digest_null",
+		     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
+		goto error;
+
+	aead = crypto_alloc_aead(authenc_name, 0, 0);
+	err = PTR_ERR(aead);
+	if (IS_ERR(aead))
+		goto error;
+
+	esp->aead = aead;
+
+	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
+		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
+	err = -ENOMEM;
+	key = kmalloc(keylen, GFP_KERNEL);
+	if (!key)
+		goto error;
+
+	p = key;
+	rta = (void *)p;
+	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
+	rta->rta_len = RTA_LENGTH(sizeof(*param));
+	param = RTA_DATA(rta);
+	p += RTA_SPACE(sizeof(*param));
+
+	if (x->aalg) {
+		struct xfrm_algo_desc *aalg_desc;
+
+		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
+		p += (x->aalg->alg_key_len + 7) / 8;
+
+		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
+		BUG_ON(!aalg_desc);
+
+		err = -EINVAL;
+		if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
+		    crypto_aead_authsize(aead)) {
+			NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
+				 x->aalg->alg_name,
+				 crypto_aead_authsize(aead),
+				 aalg_desc->uinfo.auth.icv_fullbits/8);
+			goto free_key;
+		}
+
+		err = crypto_aead_setauthsize(
+			aead, aalg_desc->uinfo.auth.icv_truncbits / 8);
+		if (err)
+			goto free_key;
+	}
+
+	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
+	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
+
+	err = crypto_aead_setkey(aead, key, keylen);
+
+free_key:
+	kfree(key);
+
+error:
+	return err;
+}
+
+static int esp_init_state(struct xfrm_state *x)
+{
+	struct esp_data *esp;
+	struct crypto_aead *aead;
+	u32 align;
+	int err;
+
+	esp = kzalloc(sizeof(*esp), GFP_KERNEL);
+	if (esp == NULL)
+		return -ENOMEM;
+
+	x->data = esp;
+
+	if (x->aead)
+		err = esp_init_aead(x);
+	else
+		err = esp_init_authenc(x);
+
+	if (err)
+		goto error;
+
+	aead = esp->aead;
+
+	esp->padlen = 0;
+
+	x->props.header_len = sizeof(struct ip_esp_hdr) +
+			      crypto_aead_ivsize(aead);
+	if (x->props.mode == XFRM_MODE_TUNNEL)
+		x->props.header_len += sizeof(struct iphdr);
+	else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
+		x->props.header_len += IPV4_BEET_PHMAXLEN;
+	if (x->encap) {
+		struct xfrm_encap_tmpl *encap = x->encap;
+
+		switch (encap->encap_type) {
+		default:
+			goto error;
+		case UDP_ENCAP_ESPINUDP:
+			x->props.header_len += sizeof(struct udphdr);
+			break;
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
+			break;
+		}
+	}
+
+	align = ALIGN(crypto_aead_blocksize(aead), 4);
+	if (esp->padlen)
+		align = max_t(u32, align, esp->padlen);
+	x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
+
+error:
+	return err;
+}
+
+static const struct xfrm_type esp_type =
+{
+	.description	= "ESP4",
+	.owner		= THIS_MODULE,
+	.proto	     	= IPPROTO_ESP,
+	.flags		= XFRM_TYPE_REPLAY_PROT,
+	.init_state	= esp_init_state,
+	.destructor	= esp_destroy,
+	.get_mtu	= esp4_get_mtu,
+	.input		= esp_input,
+	.output		= esp_output
+};
+
+static struct net_protocol esp4_protocol = {
+	.handler	=	xfrm4_rcv,
+	.err_handler	=	esp4_err,
+	.no_policy	=	1,
+};
+
+static int __init esp4_init(void)
+{
+	if (xfrm_register_type(&esp_type, AF_INET) < 0) {
+		printk(KERN_INFO "ip esp init: can't add xfrm type\n");
+		return -EAGAIN;
+	}
+	if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
+		printk(KERN_INFO "ip esp init: can't add protocol\n");
+		xfrm_unregister_type(&esp_type, AF_INET);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static void __exit esp4_fini(void)
+{
+	if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
+		printk(KERN_INFO "ip esp close: can't remove protocol\n");
+	if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
+		printk(KERN_INFO "ip esp close: can't remove xfrm type\n");
+}
+
+module_init(esp4_init);
+module_exit(esp4_fini);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
new file mode 100644
index 0000000..65c1503
--- /dev/null
+++ b/net/ipv4/fib_frontend.c
@@ -0,0 +1,1070 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 Forwarding Information Base: FIB frontend.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/capability.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_addr.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/list.h>
+
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/icmp.h>
+#include <net/arp.h>
+#include <net/ip_fib.h>
+#include <net/rtnetlink.h>
+
+#ifndef CONFIG_IP_MULTIPLE_TABLES
+
+static int __net_init fib4_rules_init(struct net *net)
+{
+	struct fib_table *local_table, *main_table;
+
+	local_table = fib_hash_table(RT_TABLE_LOCAL);
+	if (local_table == NULL)
+		return -ENOMEM;
+
+	main_table  = fib_hash_table(RT_TABLE_MAIN);
+	if (main_table == NULL)
+		goto fail;
+
+	hlist_add_head_rcu(&local_table->tb_hlist,
+				&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX]);
+	hlist_add_head_rcu(&main_table->tb_hlist,
+				&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]);
+	return 0;
+
+fail:
+	kfree(local_table);
+	return -ENOMEM;
+}
+#else
+
+struct fib_table *fib_new_table(struct net *net, u32 id)
+{
+	struct fib_table *tb;
+	unsigned int h;
+
+	if (id == 0)
+		id = RT_TABLE_MAIN;
+	tb = fib_get_table(net, id);
+	if (tb)
+		return tb;
+
+	tb = fib_hash_table(id);
+	if (!tb)
+		return NULL;
+	h = id & (FIB_TABLE_HASHSZ - 1);
+	hlist_add_head_rcu(&tb->tb_hlist, &net->ipv4.fib_table_hash[h]);
+	return tb;
+}
+
+struct fib_table *fib_get_table(struct net *net, u32 id)
+{
+	struct fib_table *tb;
+	struct hlist_node *node;
+	struct hlist_head *head;
+	unsigned int h;
+
+	if (id == 0)
+		id = RT_TABLE_MAIN;
+	h = id & (FIB_TABLE_HASHSZ - 1);
+
+	rcu_read_lock();
+	head = &net->ipv4.fib_table_hash[h];
+	hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+		if (tb->tb_id == id) {
+			rcu_read_unlock();
+			return tb;
+		}
+	}
+	rcu_read_unlock();
+	return NULL;
+}
+#endif /* CONFIG_IP_MULTIPLE_TABLES */
+
+void fib_select_default(struct net *net,
+			const struct flowi *flp, struct fib_result *res)
+{
+	struct fib_table *tb;
+	int table = RT_TABLE_MAIN;
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	if (res->r == NULL || res->r->action != FR_ACT_TO_TBL)
+		return;
+	table = res->r->table;
+#endif
+	tb = fib_get_table(net, table);
+	if (FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
+		tb->tb_select_default(tb, flp, res);
+}
+
+static void fib_flush(struct net *net)
+{
+	int flushed = 0;
+	struct fib_table *tb;
+	struct hlist_node *node;
+	struct hlist_head *head;
+	unsigned int h;
+
+	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+		head = &net->ipv4.fib_table_hash[h];
+		hlist_for_each_entry(tb, node, head, tb_hlist)
+			flushed += tb->tb_flush(tb);
+	}
+
+	if (flushed)
+		rt_cache_flush(net, -1);
+}
+
+/*
+ *	Find the first device with a given source address.
+ */
+
+struct net_device * ip_dev_find(struct net *net, __be32 addr)
+{
+	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
+	struct fib_result res;
+	struct net_device *dev = NULL;
+	struct fib_table *local_table;
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	res.r = NULL;
+#endif
+
+	local_table = fib_get_table(net, RT_TABLE_LOCAL);
+	if (!local_table || local_table->tb_lookup(local_table, &fl, &res))
+		return NULL;
+	if (res.type != RTN_LOCAL)
+		goto out;
+	dev = FIB_RES_DEV(res);
+
+	if (dev)
+		dev_hold(dev);
+out:
+	fib_res_put(&res);
+	return dev;
+}
+
+/*
+ * Find address type as if only "dev" was present in the system. If
+ * on_dev is NULL then all interfaces are taken into consideration.
+ */
+static inline unsigned __inet_dev_addr_type(struct net *net,
+					    const struct net_device *dev,
+					    __be32 addr)
+{
+	struct flowi		fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
+	struct fib_result	res;
+	unsigned ret = RTN_BROADCAST;
+	struct fib_table *local_table;
+
+	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
+		return RTN_BROADCAST;
+	if (ipv4_is_multicast(addr))
+		return RTN_MULTICAST;
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	res.r = NULL;
+#endif
+
+	local_table = fib_get_table(net, RT_TABLE_LOCAL);
+	if (local_table) {
+		ret = RTN_UNICAST;
+		if (!local_table->tb_lookup(local_table, &fl, &res)) {
+			if (!dev || dev == res.fi->fib_dev)
+				ret = res.type;
+			fib_res_put(&res);
+		}
+	}
+	return ret;
+}
+
+unsigned int inet_addr_type(struct net *net, __be32 addr)
+{
+	return __inet_dev_addr_type(net, NULL, addr);
+}
+
+unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
+				__be32 addr)
+{
+       return __inet_dev_addr_type(net, dev, addr);
+}
+
+/* Given (packet source, input interface) and optional (dst, oif, tos):
+   - (main) check, that source is valid i.e. not broadcast or our local
+     address.
+   - figure out what "logical" interface this packet arrived
+     and calculate "specific destination" address.
+   - check, that packet arrived from expected physical interface.
+ */
+
+int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
+			struct net_device *dev, __be32 *spec_dst, u32 *itag)
+{
+	struct in_device *in_dev;
+	struct flowi fl = { .nl_u = { .ip4_u =
+				      { .daddr = src,
+					.saddr = dst,
+					.tos = tos } },
+			    .iif = oif };
+	struct fib_result res;
+	int no_addr, rpf;
+	int ret;
+	struct net *net;
+
+	no_addr = rpf = 0;
+	rcu_read_lock();
+	in_dev = __in_dev_get_rcu(dev);
+	if (in_dev) {
+		no_addr = in_dev->ifa_list == NULL;
+		rpf = IN_DEV_RPFILTER(in_dev);
+	}
+	rcu_read_unlock();
+
+	if (in_dev == NULL)
+		goto e_inval;
+
+	net = dev_net(dev);
+	if (fib_lookup(net, &fl, &res))
+		goto last_resort;
+	if (res.type != RTN_UNICAST)
+		goto e_inval_res;
+	*spec_dst = FIB_RES_PREFSRC(res);
+	fib_combine_itag(itag, &res);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	if (FIB_RES_DEV(res) == dev || res.fi->fib_nhs > 1)
+#else
+	if (FIB_RES_DEV(res) == dev)
+#endif
+	{
+		ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
+		fib_res_put(&res);
+		return ret;
+	}
+	fib_res_put(&res);
+	if (no_addr)
+		goto last_resort;
+	if (rpf)
+		goto e_inval;
+	fl.oif = dev->ifindex;
+
+	ret = 0;
+	if (fib_lookup(net, &fl, &res) == 0) {
+		if (res.type == RTN_UNICAST) {
+			*spec_dst = FIB_RES_PREFSRC(res);
+			ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
+		}
+		fib_res_put(&res);
+	}
+	return ret;
+
+last_resort:
+	if (rpf)
+		goto e_inval;
+	*spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
+	*itag = 0;
+	return 0;
+
+e_inval_res:
+	fib_res_put(&res);
+e_inval:
+	return -EINVAL;
+}
+
+static inline __be32 sk_extract_addr(struct sockaddr *addr)
+{
+	return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
+}
+
+static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
+{
+	struct nlattr *nla;
+
+	nla = (struct nlattr *) ((char *) mx + len);
+	nla->nla_type = type;
+	nla->nla_len = nla_attr_size(4);
+	*(u32 *) nla_data(nla) = value;
+
+	return len + nla_total_size(4);
+}
+
+static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
+				 struct fib_config *cfg)
+{
+	__be32 addr;
+	int plen;
+
+	memset(cfg, 0, sizeof(*cfg));
+	cfg->fc_nlinfo.nl_net = net;
+
+	if (rt->rt_dst.sa_family != AF_INET)
+		return -EAFNOSUPPORT;
+
+	/*
+	 * Check mask for validity:
+	 * a) it must be contiguous.
+	 * b) destination must have all host bits clear.
+	 * c) if application forgot to set correct family (AF_INET),
+	 *    reject request unless it is absolutely clear i.e.
+	 *    both family and mask are zero.
+	 */
+	plen = 32;
+	addr = sk_extract_addr(&rt->rt_dst);
+	if (!(rt->rt_flags & RTF_HOST)) {
+		__be32 mask = sk_extract_addr(&rt->rt_genmask);
+
+		if (rt->rt_genmask.sa_family != AF_INET) {
+			if (mask || rt->rt_genmask.sa_family)
+				return -EAFNOSUPPORT;
+		}
+
+		if (bad_mask(mask, addr))
+			return -EINVAL;
+
+		plen = inet_mask_len(mask);
+	}
+
+	cfg->fc_dst_len = plen;
+	cfg->fc_dst = addr;
+
+	if (cmd != SIOCDELRT) {
+		cfg->fc_nlflags = NLM_F_CREATE;
+		cfg->fc_protocol = RTPROT_BOOT;
+	}
+
+	if (rt->rt_metric)
+		cfg->fc_priority = rt->rt_metric - 1;
+
+	if (rt->rt_flags & RTF_REJECT) {
+		cfg->fc_scope = RT_SCOPE_HOST;
+		cfg->fc_type = RTN_UNREACHABLE;
+		return 0;
+	}
+
+	cfg->fc_scope = RT_SCOPE_NOWHERE;
+	cfg->fc_type = RTN_UNICAST;
+
+	if (rt->rt_dev) {
+		char *colon;
+		struct net_device *dev;
+		char devname[IFNAMSIZ];
+
+		if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
+			return -EFAULT;
+
+		devname[IFNAMSIZ-1] = 0;
+		colon = strchr(devname, ':');
+		if (colon)
+			*colon = 0;
+		dev = __dev_get_by_name(net, devname);
+		if (!dev)
+			return -ENODEV;
+		cfg->fc_oif = dev->ifindex;
+		if (colon) {
+			struct in_ifaddr *ifa;
+			struct in_device *in_dev = __in_dev_get_rtnl(dev);
+			if (!in_dev)
+				return -ENODEV;
+			*colon = ':';
+			for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
+				if (strcmp(ifa->ifa_label, devname) == 0)
+					break;
+			if (ifa == NULL)
+				return -ENODEV;
+			cfg->fc_prefsrc = ifa->ifa_local;
+		}
+	}
+
+	addr = sk_extract_addr(&rt->rt_gateway);
+	if (rt->rt_gateway.sa_family == AF_INET && addr) {
+		cfg->fc_gw = addr;
+		if (rt->rt_flags & RTF_GATEWAY &&
+		    inet_addr_type(net, addr) == RTN_UNICAST)
+			cfg->fc_scope = RT_SCOPE_UNIVERSE;
+	}
+
+	if (cmd == SIOCDELRT)
+		return 0;
+
+	if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
+		return -EINVAL;
+
+	if (cfg->fc_scope == RT_SCOPE_NOWHERE)
+		cfg->fc_scope = RT_SCOPE_LINK;
+
+	if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
+		struct nlattr *mx;
+		int len = 0;
+
+		mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
+		if (mx == NULL)
+			return -ENOMEM;
+
+		if (rt->rt_flags & RTF_MTU)
+			len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
+
+		if (rt->rt_flags & RTF_WINDOW)
+			len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
+
+		if (rt->rt_flags & RTF_IRTT)
+			len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
+
+		cfg->fc_mx = mx;
+		cfg->fc_mx_len = len;
+	}
+
+	return 0;
+}
+
+/*
+ *	Handle IP routing ioctl calls. These are used to manipulate the routing tables
+ */
+
+int ip_rt_ioctl(struct net *net, unsigned int cmd, void __user *arg)
+{
+	struct fib_config cfg;
+	struct rtentry rt;
+	int err;
+
+	switch (cmd) {
+	case SIOCADDRT:		/* Add a route */
+	case SIOCDELRT:		/* Delete a route */
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+
+		if (copy_from_user(&rt, arg, sizeof(rt)))
+			return -EFAULT;
+
+		rtnl_lock();
+		err = rtentry_to_fib_config(net, cmd, &rt, &cfg);
+		if (err == 0) {
+			struct fib_table *tb;
+
+			if (cmd == SIOCDELRT) {
+				tb = fib_get_table(net, cfg.fc_table);
+				if (tb)
+					err = tb->tb_delete(tb, &cfg);
+				else
+					err = -ESRCH;
+			} else {
+				tb = fib_new_table(net, cfg.fc_table);
+				if (tb)
+					err = tb->tb_insert(tb, &cfg);
+				else
+					err = -ENOBUFS;
+			}
+
+			/* allocated by rtentry_to_fib_config() */
+			kfree(cfg.fc_mx);
+		}
+		rtnl_unlock();
+		return err;
+	}
+	return -EINVAL;
+}
+
+const struct nla_policy rtm_ipv4_policy[RTA_MAX+1] = {
+	[RTA_DST]		= { .type = NLA_U32 },
+	[RTA_SRC]		= { .type = NLA_U32 },
+	[RTA_IIF]		= { .type = NLA_U32 },
+	[RTA_OIF]		= { .type = NLA_U32 },
+	[RTA_GATEWAY]		= { .type = NLA_U32 },
+	[RTA_PRIORITY]		= { .type = NLA_U32 },
+	[RTA_PREFSRC]		= { .type = NLA_U32 },
+	[RTA_METRICS]		= { .type = NLA_NESTED },
+	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
+	[RTA_FLOW]		= { .type = NLA_U32 },
+};
+
+static int rtm_to_fib_config(struct net *net, struct sk_buff *skb,
+			    struct nlmsghdr *nlh, struct fib_config *cfg)
+{
+	struct nlattr *attr;
+	int err, remaining;
+	struct rtmsg *rtm;
+
+	err = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipv4_policy);
+	if (err < 0)
+		goto errout;
+
+	memset(cfg, 0, sizeof(*cfg));
+
+	rtm = nlmsg_data(nlh);
+	cfg->fc_dst_len = rtm->rtm_dst_len;
+	cfg->fc_tos = rtm->rtm_tos;
+	cfg->fc_table = rtm->rtm_table;
+	cfg->fc_protocol = rtm->rtm_protocol;
+	cfg->fc_scope = rtm->rtm_scope;
+	cfg->fc_type = rtm->rtm_type;
+	cfg->fc_flags = rtm->rtm_flags;
+	cfg->fc_nlflags = nlh->nlmsg_flags;
+
+	cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
+	cfg->fc_nlinfo.nlh = nlh;
+	cfg->fc_nlinfo.nl_net = net;
+
+	if (cfg->fc_type > RTN_MAX) {
+		err = -EINVAL;
+		goto errout;
+	}
+
+	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
+		switch (nla_type(attr)) {
+		case RTA_DST:
+			cfg->fc_dst = nla_get_be32(attr);
+			break;
+		case RTA_OIF:
+			cfg->fc_oif = nla_get_u32(attr);
+			break;
+		case RTA_GATEWAY:
+			cfg->fc_gw = nla_get_be32(attr);
+			break;
+		case RTA_PRIORITY:
+			cfg->fc_priority = nla_get_u32(attr);
+			break;
+		case RTA_PREFSRC:
+			cfg->fc_prefsrc = nla_get_be32(attr);
+			break;
+		case RTA_METRICS:
+			cfg->fc_mx = nla_data(attr);
+			cfg->fc_mx_len = nla_len(attr);
+			break;
+		case RTA_MULTIPATH:
+			cfg->fc_mp = nla_data(attr);
+			cfg->fc_mp_len = nla_len(attr);
+			break;
+		case RTA_FLOW:
+			cfg->fc_flow = nla_get_u32(attr);
+			break;
+		case RTA_TABLE:
+			cfg->fc_table = nla_get_u32(attr);
+			break;
+		}
+	}
+
+	return 0;
+errout:
+	return err;
+}
+
+static int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct fib_config cfg;
+	struct fib_table *tb;
+	int err;
+
+	err = rtm_to_fib_config(net, skb, nlh, &cfg);
+	if (err < 0)
+		goto errout;
+
+	tb = fib_get_table(net, cfg.fc_table);
+	if (tb == NULL) {
+		err = -ESRCH;
+		goto errout;
+	}
+
+	err = tb->tb_delete(tb, &cfg);
+errout:
+	return err;
+}
+
+static int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
+{
+	struct net *net = sock_net(skb->sk);
+	struct fib_config cfg;
+	struct fib_table *tb;
+	int err;
+
+	err = rtm_to_fib_config(net, skb, nlh, &cfg);
+	if (err < 0)
+		goto errout;
+
+	tb = fib_new_table(net, cfg.fc_table);
+	if (tb == NULL) {
+		err = -ENOBUFS;
+		goto errout;
+	}
+
+	err = tb->tb_insert(tb, &cfg);
+errout:
+	return err;
+}
+
+static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	unsigned int h, s_h;
+	unsigned int e = 0, s_e;
+	struct fib_table *tb;
+	struct hlist_node *node;
+	struct hlist_head *head;
+	int dumped = 0;
+
+	if (nlmsg_len(cb->nlh) >= sizeof(struct rtmsg) &&
+	    ((struct rtmsg *) nlmsg_data(cb->nlh))->rtm_flags & RTM_F_CLONED)
+		return ip_rt_dump(skb, cb);
+
+	s_h = cb->args[0];
+	s_e = cb->args[1];
+
+	for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) {
+		e = 0;
+		head = &net->ipv4.fib_table_hash[h];
+		hlist_for_each_entry(tb, node, head, tb_hlist) {
+			if (e < s_e)
+				goto next;
+			if (dumped)
+				memset(&cb->args[2], 0, sizeof(cb->args) -
+						 2 * sizeof(cb->args[0]));
+			if (tb->tb_dump(tb, skb, cb) < 0)
+				goto out;
+			dumped = 1;
+next:
+			e++;
+		}
+	}
+out:
+	cb->args[1] = e;
+	cb->args[0] = h;
+
+	return skb->len;
+}
+
+/* Prepare and feed intra-kernel routing request.
+   Really, it should be netlink message, but :-( netlink
+   can be not configured, so that we feed it directly
+   to fib engine. It is legal, because all events occur
+   only when netlink is already locked.
+ */
+
+static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
+{
+	struct net *net = dev_net(ifa->ifa_dev->dev);
+	struct fib_table *tb;
+	struct fib_config cfg = {
+		.fc_protocol = RTPROT_KERNEL,
+		.fc_type = type,
+		.fc_dst = dst,
+		.fc_dst_len = dst_len,
+		.fc_prefsrc = ifa->ifa_local,
+		.fc_oif = ifa->ifa_dev->dev->ifindex,
+		.fc_nlflags = NLM_F_CREATE | NLM_F_APPEND,
+		.fc_nlinfo = {
+			.nl_net = net,
+		},
+	};
+
+	if (type == RTN_UNICAST)
+		tb = fib_new_table(net, RT_TABLE_MAIN);
+	else
+		tb = fib_new_table(net, RT_TABLE_LOCAL);
+
+	if (tb == NULL)
+		return;
+
+	cfg.fc_table = tb->tb_id;
+
+	if (type != RTN_LOCAL)
+		cfg.fc_scope = RT_SCOPE_LINK;
+	else
+		cfg.fc_scope = RT_SCOPE_HOST;
+
+	if (cmd == RTM_NEWROUTE)
+		tb->tb_insert(tb, &cfg);
+	else
+		tb->tb_delete(tb, &cfg);
+}
+
+void fib_add_ifaddr(struct in_ifaddr *ifa)
+{
+	struct in_device *in_dev = ifa->ifa_dev;
+	struct net_device *dev = in_dev->dev;
+	struct in_ifaddr *prim = ifa;
+	__be32 mask = ifa->ifa_mask;
+	__be32 addr = ifa->ifa_local;
+	__be32 prefix = ifa->ifa_address&mask;
+
+	if (ifa->ifa_flags&IFA_F_SECONDARY) {
+		prim = inet_ifa_byprefix(in_dev, prefix, mask);
+		if (prim == NULL) {
+			printk(KERN_WARNING "fib_add_ifaddr: bug: prim == NULL\n");
+			return;
+		}
+	}
+
+	fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
+
+	if (!(dev->flags&IFF_UP))
+		return;
+
+	/* Add broadcast address, if it is explicitly assigned. */
+	if (ifa->ifa_broadcast && ifa->ifa_broadcast != htonl(0xFFFFFFFF))
+		fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
+
+	if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) &&
+	    (prefix != addr || ifa->ifa_prefixlen < 32)) {
+		fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL :
+			  RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim);
+
+		/* Add network specific broadcasts, when it takes a sense */
+		if (ifa->ifa_prefixlen < 31) {
+			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
+			fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim);
+		}
+	}
+}
+
+static void fib_del_ifaddr(struct in_ifaddr *ifa)
+{
+	struct in_device *in_dev = ifa->ifa_dev;
+	struct net_device *dev = in_dev->dev;
+	struct in_ifaddr *ifa1;
+	struct in_ifaddr *prim = ifa;
+	__be32 brd = ifa->ifa_address|~ifa->ifa_mask;
+	__be32 any = ifa->ifa_address&ifa->ifa_mask;
+#define LOCAL_OK	1
+#define BRD_OK		2
+#define BRD0_OK		4
+#define BRD1_OK		8
+	unsigned ok = 0;
+
+	if (!(ifa->ifa_flags&IFA_F_SECONDARY))
+		fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL :
+			  RTN_UNICAST, any, ifa->ifa_prefixlen, prim);
+	else {
+		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
+		if (prim == NULL) {
+			printk(KERN_WARNING "fib_del_ifaddr: bug: prim == NULL\n");
+			return;
+		}
+	}
+
+	/* Deletion is more complicated than add.
+	   We should take care of not to delete too much :-)
+
+	   Scan address list to be sure that addresses are really gone.
+	 */
+
+	for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
+		if (ifa->ifa_local == ifa1->ifa_local)
+			ok |= LOCAL_OK;
+		if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
+			ok |= BRD_OK;
+		if (brd == ifa1->ifa_broadcast)
+			ok |= BRD1_OK;
+		if (any == ifa1->ifa_broadcast)
+			ok |= BRD0_OK;
+	}
+
+	if (!(ok&BRD_OK))
+		fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
+	if (!(ok&BRD1_OK))
+		fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
+	if (!(ok&BRD0_OK))
+		fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
+	if (!(ok&LOCAL_OK)) {
+		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
+
+		/* Check, that this local address finally disappeared. */
+		if (inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
+			/* And the last, but not the least thing.
+			   We must flush stray FIB entries.
+
+			   First of all, we scan fib_info list searching
+			   for stray nexthop entries, then ignite fib_flush.
+			*/
+			if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local))
+				fib_flush(dev_net(dev));
+		}
+	}
+#undef LOCAL_OK
+#undef BRD_OK
+#undef BRD0_OK
+#undef BRD1_OK
+}
+
+static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb )
+{
+
+	struct fib_result       res;
+	struct flowi            fl = { .mark = frn->fl_mark,
+				       .nl_u = { .ip4_u = { .daddr = frn->fl_addr,
+							    .tos = frn->fl_tos,
+							    .scope = frn->fl_scope } } };
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	res.r = NULL;
+#endif
+
+	frn->err = -ENOENT;
+	if (tb) {
+		local_bh_disable();
+
+		frn->tb_id = tb->tb_id;
+		frn->err = tb->tb_lookup(tb, &fl, &res);
+
+		if (!frn->err) {
+			frn->prefixlen = res.prefixlen;
+			frn->nh_sel = res.nh_sel;
+			frn->type = res.type;
+			frn->scope = res.scope;
+			fib_res_put(&res);
+		}
+		local_bh_enable();
+	}
+}
+
+static void nl_fib_input(struct sk_buff *skb)
+{
+	struct net *net;
+	struct fib_result_nl *frn;
+	struct nlmsghdr *nlh;
+	struct fib_table *tb;
+	u32 pid;
+
+	net = sock_net(skb->sk);
+	nlh = nlmsg_hdr(skb);
+	if (skb->len < NLMSG_SPACE(0) || skb->len < nlh->nlmsg_len ||
+	    nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*frn)))
+		return;
+
+	skb = skb_clone(skb, GFP_KERNEL);
+	if (skb == NULL)
+		return;
+	nlh = nlmsg_hdr(skb);
+
+	frn = (struct fib_result_nl *) NLMSG_DATA(nlh);
+	tb = fib_get_table(net, frn->tb_id_in);
+
+	nl_fib_lookup(frn, tb);
+
+	pid = NETLINK_CB(skb).pid;       /* pid of sending process */
+	NETLINK_CB(skb).pid = 0;         /* from kernel */
+	NETLINK_CB(skb).dst_group = 0;  /* unicast */
+	netlink_unicast(net->ipv4.fibnl, skb, pid, MSG_DONTWAIT);
+}
+
+static int nl_fib_lookup_init(struct net *net)
+{
+	struct sock *sk;
+	sk = netlink_kernel_create(net, NETLINK_FIB_LOOKUP, 0,
+				   nl_fib_input, NULL, THIS_MODULE);
+	if (sk == NULL)
+		return -EAFNOSUPPORT;
+	net->ipv4.fibnl = sk;
+	return 0;
+}
+
+static void nl_fib_lookup_exit(struct net *net)
+{
+	netlink_kernel_release(net->ipv4.fibnl);
+	net->ipv4.fibnl = NULL;
+}
+
+static void fib_disable_ip(struct net_device *dev, int force)
+{
+	if (fib_sync_down_dev(dev, force))
+		fib_flush(dev_net(dev));
+	rt_cache_flush(dev_net(dev), 0);
+	arp_ifdown(dev);
+}
+
+static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct in_ifaddr *ifa = (struct in_ifaddr*)ptr;
+	struct net_device *dev = ifa->ifa_dev->dev;
+
+	switch (event) {
+	case NETDEV_UP:
+		fib_add_ifaddr(ifa);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+		fib_sync_up(dev);
+#endif
+		rt_cache_flush(dev_net(dev), -1);
+		break;
+	case NETDEV_DOWN:
+		fib_del_ifaddr(ifa);
+		if (ifa->ifa_dev->ifa_list == NULL) {
+			/* Last address was deleted from this interface.
+			   Disable IP.
+			 */
+			fib_disable_ip(dev, 1);
+		} else {
+			rt_cache_flush(dev_net(dev), -1);
+		}
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+	struct in_device *in_dev = __in_dev_get_rtnl(dev);
+
+	if (event == NETDEV_UNREGISTER) {
+		fib_disable_ip(dev, 2);
+		return NOTIFY_DONE;
+	}
+
+	if (!in_dev)
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_UP:
+		for_ifa(in_dev) {
+			fib_add_ifaddr(ifa);
+		} endfor_ifa(in_dev);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+		fib_sync_up(dev);
+#endif
+		rt_cache_flush(dev_net(dev), -1);
+		break;
+	case NETDEV_DOWN:
+		fib_disable_ip(dev, 0);
+		break;
+	case NETDEV_CHANGEMTU:
+	case NETDEV_CHANGE:
+		rt_cache_flush(dev_net(dev), 0);
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block fib_inetaddr_notifier = {
+	.notifier_call =fib_inetaddr_event,
+};
+
+static struct notifier_block fib_netdev_notifier = {
+	.notifier_call =fib_netdev_event,
+};
+
+static int __net_init ip_fib_net_init(struct net *net)
+{
+	int err;
+	unsigned int i;
+
+	net->ipv4.fib_table_hash = kzalloc(
+			sizeof(struct hlist_head)*FIB_TABLE_HASHSZ, GFP_KERNEL);
+	if (net->ipv4.fib_table_hash == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < FIB_TABLE_HASHSZ; i++)
+		INIT_HLIST_HEAD(&net->ipv4.fib_table_hash[i]);
+
+	err = fib4_rules_init(net);
+	if (err < 0)
+		goto fail;
+	return 0;
+
+fail:
+	kfree(net->ipv4.fib_table_hash);
+	return err;
+}
+
+static void __net_exit ip_fib_net_exit(struct net *net)
+{
+	unsigned int i;
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	fib4_rules_exit(net);
+#endif
+
+	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+		struct fib_table *tb;
+		struct hlist_head *head;
+		struct hlist_node *node, *tmp;
+
+		head = &net->ipv4.fib_table_hash[i];
+		hlist_for_each_entry_safe(tb, node, tmp, head, tb_hlist) {
+			hlist_del(node);
+			tb->tb_flush(tb);
+			kfree(tb);
+		}
+	}
+	kfree(net->ipv4.fib_table_hash);
+}
+
+static int __net_init fib_net_init(struct net *net)
+{
+	int error;
+
+	error = ip_fib_net_init(net);
+	if (error < 0)
+		goto out;
+	error = nl_fib_lookup_init(net);
+	if (error < 0)
+		goto out_nlfl;
+	error = fib_proc_init(net);
+	if (error < 0)
+		goto out_proc;
+out:
+	return error;
+
+out_proc:
+	nl_fib_lookup_exit(net);
+out_nlfl:
+	ip_fib_net_exit(net);
+	goto out;
+}
+
+static void __net_exit fib_net_exit(struct net *net)
+{
+	fib_proc_exit(net);
+	nl_fib_lookup_exit(net);
+	ip_fib_net_exit(net);
+}
+
+static struct pernet_operations fib_net_ops = {
+	.init = fib_net_init,
+	.exit = fib_net_exit,
+};
+
+void __init ip_fib_init(void)
+{
+	rtnl_register(PF_INET, RTM_NEWROUTE, inet_rtm_newroute, NULL);
+	rtnl_register(PF_INET, RTM_DELROUTE, inet_rtm_delroute, NULL);
+	rtnl_register(PF_INET, RTM_GETROUTE, NULL, inet_dump_fib);
+
+	register_pernet_subsys(&fib_net_ops);
+	register_netdevice_notifier(&fib_netdev_notifier);
+	register_inetaddr_notifier(&fib_inetaddr_notifier);
+
+	fib_hash_init();
+}
+
+EXPORT_SYMBOL(inet_addr_type);
+EXPORT_SYMBOL(inet_dev_addr_type);
+EXPORT_SYMBOL(ip_dev_find);
diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
new file mode 100644
index 0000000..c8cac6c
--- /dev/null
+++ b/net/ipv4/fib_hash.c
@@ -0,0 +1,1075 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 FIB: lookup engine and maintenance routines.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+
+#include "fib_lookup.h"
+
+static struct kmem_cache *fn_hash_kmem __read_mostly;
+static struct kmem_cache *fn_alias_kmem __read_mostly;
+
+struct fib_node {
+	struct hlist_node	fn_hash;
+	struct list_head	fn_alias;
+	__be32			fn_key;
+	struct fib_alias        fn_embedded_alias;
+};
+
+struct fn_zone {
+	struct fn_zone		*fz_next;	/* Next not empty zone	*/
+	struct hlist_head	*fz_hash;	/* Hash table pointer	*/
+	int			fz_nent;	/* Number of entries	*/
+
+	int			fz_divisor;	/* Hash divisor		*/
+	u32			fz_hashmask;	/* (fz_divisor - 1)	*/
+#define FZ_HASHMASK(fz)		((fz)->fz_hashmask)
+
+	int			fz_order;	/* Zone order		*/
+	__be32			fz_mask;
+#define FZ_MASK(fz)		((fz)->fz_mask)
+};
+
+/* NOTE. On fast computers evaluation of fz_hashmask and fz_mask
+ * can be cheaper than memory lookup, so that FZ_* macros are used.
+ */
+
+struct fn_hash {
+	struct fn_zone	*fn_zones[33];
+	struct fn_zone	*fn_zone_list;
+};
+
+static inline u32 fn_hash(__be32 key, struct fn_zone *fz)
+{
+	u32 h = ntohl(key)>>(32 - fz->fz_order);
+	h ^= (h>>20);
+	h ^= (h>>10);
+	h ^= (h>>5);
+	h &= FZ_HASHMASK(fz);
+	return h;
+}
+
+static inline __be32 fz_key(__be32 dst, struct fn_zone *fz)
+{
+	return dst & FZ_MASK(fz);
+}
+
+static DEFINE_RWLOCK(fib_hash_lock);
+static unsigned int fib_hash_genid;
+
+#define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head))
+
+static struct hlist_head *fz_hash_alloc(int divisor)
+{
+	unsigned long size = divisor * sizeof(struct hlist_head);
+
+	if (size <= PAGE_SIZE) {
+		return kzalloc(size, GFP_KERNEL);
+	} else {
+		return (struct hlist_head *)
+			__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size));
+	}
+}
+
+/* The fib hash lock must be held when this is called. */
+static inline void fn_rebuild_zone(struct fn_zone *fz,
+				   struct hlist_head *old_ht,
+				   int old_divisor)
+{
+	int i;
+
+	for (i = 0; i < old_divisor; i++) {
+		struct hlist_node *node, *n;
+		struct fib_node *f;
+
+		hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) {
+			struct hlist_head *new_head;
+
+			hlist_del(&f->fn_hash);
+
+			new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
+			hlist_add_head(&f->fn_hash, new_head);
+		}
+	}
+}
+
+static void fz_hash_free(struct hlist_head *hash, int divisor)
+{
+	unsigned long size = divisor * sizeof(struct hlist_head);
+
+	if (size <= PAGE_SIZE)
+		kfree(hash);
+	else
+		free_pages((unsigned long)hash, get_order(size));
+}
+
+static void fn_rehash_zone(struct fn_zone *fz)
+{
+	struct hlist_head *ht, *old_ht;
+	int old_divisor, new_divisor;
+	u32 new_hashmask;
+
+	old_divisor = fz->fz_divisor;
+
+	switch (old_divisor) {
+	case 16:
+		new_divisor = 256;
+		break;
+	case 256:
+		new_divisor = 1024;
+		break;
+	default:
+		if ((old_divisor << 1) > FZ_MAX_DIVISOR) {
+			printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor);
+			return;
+		}
+		new_divisor = (old_divisor << 1);
+		break;
+	}
+
+	new_hashmask = (new_divisor - 1);
+
+#if RT_CACHE_DEBUG >= 2
+	printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n",
+	       fz->fz_order, old_divisor);
+#endif
+
+	ht = fz_hash_alloc(new_divisor);
+
+	if (ht)	{
+		write_lock_bh(&fib_hash_lock);
+		old_ht = fz->fz_hash;
+		fz->fz_hash = ht;
+		fz->fz_hashmask = new_hashmask;
+		fz->fz_divisor = new_divisor;
+		fn_rebuild_zone(fz, old_ht, old_divisor);
+		fib_hash_genid++;
+		write_unlock_bh(&fib_hash_lock);
+
+		fz_hash_free(old_ht, old_divisor);
+	}
+}
+
+static inline void fn_free_node(struct fib_node * f)
+{
+	kmem_cache_free(fn_hash_kmem, f);
+}
+
+static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f)
+{
+	fib_release_info(fa->fa_info);
+	if (fa == &f->fn_embedded_alias)
+		fa->fa_info = NULL;
+	else
+		kmem_cache_free(fn_alias_kmem, fa);
+}
+
+static struct fn_zone *
+fn_new_zone(struct fn_hash *table, int z)
+{
+	int i;
+	struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL);
+	if (!fz)
+		return NULL;
+
+	if (z) {
+		fz->fz_divisor = 16;
+	} else {
+		fz->fz_divisor = 1;
+	}
+	fz->fz_hashmask = (fz->fz_divisor - 1);
+	fz->fz_hash = fz_hash_alloc(fz->fz_divisor);
+	if (!fz->fz_hash) {
+		kfree(fz);
+		return NULL;
+	}
+	fz->fz_order = z;
+	fz->fz_mask = inet_make_mask(z);
+
+	/* Find the first not empty zone with more specific mask */
+	for (i=z+1; i<=32; i++)
+		if (table->fn_zones[i])
+			break;
+	write_lock_bh(&fib_hash_lock);
+	if (i>32) {
+		/* No more specific masks, we are the first. */
+		fz->fz_next = table->fn_zone_list;
+		table->fn_zone_list = fz;
+	} else {
+		fz->fz_next = table->fn_zones[i]->fz_next;
+		table->fn_zones[i]->fz_next = fz;
+	}
+	table->fn_zones[z] = fz;
+	fib_hash_genid++;
+	write_unlock_bh(&fib_hash_lock);
+	return fz;
+}
+
+static int
+fn_hash_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
+{
+	int err;
+	struct fn_zone *fz;
+	struct fn_hash *t = (struct fn_hash*)tb->tb_data;
+
+	read_lock(&fib_hash_lock);
+	for (fz = t->fn_zone_list; fz; fz = fz->fz_next) {
+		struct hlist_head *head;
+		struct hlist_node *node;
+		struct fib_node *f;
+		__be32 k = fz_key(flp->fl4_dst, fz);
+
+		head = &fz->fz_hash[fn_hash(k, fz)];
+		hlist_for_each_entry(f, node, head, fn_hash) {
+			if (f->fn_key != k)
+				continue;
+
+			err = fib_semantic_match(&f->fn_alias,
+						 flp, res,
+						 f->fn_key, fz->fz_mask,
+						 fz->fz_order);
+			if (err <= 0)
+				goto out;
+		}
+	}
+	err = 1;
+out:
+	read_unlock(&fib_hash_lock);
+	return err;
+}
+
+static void
+fn_hash_select_default(struct fib_table *tb, const struct flowi *flp, struct fib_result *res)
+{
+	int order, last_idx;
+	struct hlist_node *node;
+	struct fib_node *f;
+	struct fib_info *fi = NULL;
+	struct fib_info *last_resort;
+	struct fn_hash *t = (struct fn_hash*)tb->tb_data;
+	struct fn_zone *fz = t->fn_zones[0];
+
+	if (fz == NULL)
+		return;
+
+	last_idx = -1;
+	last_resort = NULL;
+	order = -1;
+
+	read_lock(&fib_hash_lock);
+	hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) {
+		struct fib_alias *fa;
+
+		list_for_each_entry(fa, &f->fn_alias, fa_list) {
+			struct fib_info *next_fi = fa->fa_info;
+
+			if (fa->fa_scope != res->scope ||
+			    fa->fa_type != RTN_UNICAST)
+				continue;
+
+			if (next_fi->fib_priority > res->fi->fib_priority)
+				break;
+			if (!next_fi->fib_nh[0].nh_gw ||
+			    next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
+				continue;
+			fa->fa_state |= FA_S_ACCESSED;
+
+			if (fi == NULL) {
+				if (next_fi != res->fi)
+					break;
+			} else if (!fib_detect_death(fi, order, &last_resort,
+						&last_idx, tb->tb_default)) {
+				fib_result_assign(res, fi);
+				tb->tb_default = order;
+				goto out;
+			}
+			fi = next_fi;
+			order++;
+		}
+	}
+
+	if (order <= 0 || fi == NULL) {
+		tb->tb_default = -1;
+		goto out;
+	}
+
+	if (!fib_detect_death(fi, order, &last_resort, &last_idx,
+				tb->tb_default)) {
+		fib_result_assign(res, fi);
+		tb->tb_default = order;
+		goto out;
+	}
+
+	if (last_idx >= 0)
+		fib_result_assign(res, last_resort);
+	tb->tb_default = last_idx;
+out:
+	read_unlock(&fib_hash_lock);
+}
+
+/* Insert node F to FZ. */
+static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f)
+{
+	struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)];
+
+	hlist_add_head(&f->fn_hash, head);
+}
+
+/* Return the node in FZ matching KEY. */
+static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key)
+{
+	struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)];
+	struct hlist_node *node;
+	struct fib_node *f;
+
+	hlist_for_each_entry(f, node, head, fn_hash) {
+		if (f->fn_key == key)
+			return f;
+	}
+
+	return NULL;
+}
+
+static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
+{
+	struct fn_hash *table = (struct fn_hash *) tb->tb_data;
+	struct fib_node *new_f = NULL;
+	struct fib_node *f;
+	struct fib_alias *fa, *new_fa;
+	struct fn_zone *fz;
+	struct fib_info *fi;
+	u8 tos = cfg->fc_tos;
+	__be32 key;
+	int err;
+
+	if (cfg->fc_dst_len > 32)
+		return -EINVAL;
+
+	fz = table->fn_zones[cfg->fc_dst_len];
+	if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
+		return -ENOBUFS;
+
+	key = 0;
+	if (cfg->fc_dst) {
+		if (cfg->fc_dst & ~FZ_MASK(fz))
+			return -EINVAL;
+		key = fz_key(cfg->fc_dst, fz);
+	}
+
+	fi = fib_create_info(cfg);
+	if (IS_ERR(fi))
+		return PTR_ERR(fi);
+
+	if (fz->fz_nent > (fz->fz_divisor<<1) &&
+	    fz->fz_divisor < FZ_MAX_DIVISOR &&
+	    (cfg->fc_dst_len == 32 ||
+	     (1 << cfg->fc_dst_len) > fz->fz_divisor))
+		fn_rehash_zone(fz);
+
+	f = fib_find_node(fz, key);
+
+	if (!f)
+		fa = NULL;
+	else
+		fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority);
+
+	/* Now fa, if non-NULL, points to the first fib alias
+	 * with the same keys [prefix,tos,priority], if such key already
+	 * exists or to the node before which we will insert new one.
+	 *
+	 * If fa is NULL, we will need to allocate a new one and
+	 * insert to the head of f.
+	 *
+	 * If f is NULL, no fib node matched the destination key
+	 * and we need to allocate a new one of those as well.
+	 */
+
+	if (fa && fa->fa_tos == tos &&
+	    fa->fa_info->fib_priority == fi->fib_priority) {
+		struct fib_alias *fa_first, *fa_match;
+
+		err = -EEXIST;
+		if (cfg->fc_nlflags & NLM_F_EXCL)
+			goto out;
+
+		/* We have 2 goals:
+		 * 1. Find exact match for type, scope, fib_info to avoid
+		 * duplicate routes
+		 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
+		 */
+		fa_match = NULL;
+		fa_first = fa;
+		fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+		list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
+			if (fa->fa_tos != tos)
+				break;
+			if (fa->fa_info->fib_priority != fi->fib_priority)
+				break;
+			if (fa->fa_type == cfg->fc_type &&
+			    fa->fa_scope == cfg->fc_scope &&
+			    fa->fa_info == fi) {
+				fa_match = fa;
+				break;
+			}
+		}
+
+		if (cfg->fc_nlflags & NLM_F_REPLACE) {
+			struct fib_info *fi_drop;
+			u8 state;
+
+			fa = fa_first;
+			if (fa_match) {
+				if (fa == fa_match)
+					err = 0;
+				goto out;
+			}
+			write_lock_bh(&fib_hash_lock);
+			fi_drop = fa->fa_info;
+			fa->fa_info = fi;
+			fa->fa_type = cfg->fc_type;
+			fa->fa_scope = cfg->fc_scope;
+			state = fa->fa_state;
+			fa->fa_state &= ~FA_S_ACCESSED;
+			fib_hash_genid++;
+			write_unlock_bh(&fib_hash_lock);
+
+			fib_release_info(fi_drop);
+			if (state & FA_S_ACCESSED)
+				rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+			rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id,
+				  &cfg->fc_nlinfo, NLM_F_REPLACE);
+			return 0;
+		}
+
+		/* Error if we find a perfect match which
+		 * uses the same scope, type, and nexthop
+		 * information.
+		 */
+		if (fa_match)
+			goto out;
+
+		if (!(cfg->fc_nlflags & NLM_F_APPEND))
+			fa = fa_first;
+	}
+
+	err = -ENOENT;
+	if (!(cfg->fc_nlflags & NLM_F_CREATE))
+		goto out;
+
+	err = -ENOBUFS;
+
+	if (!f) {
+		new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL);
+		if (new_f == NULL)
+			goto out;
+
+		INIT_HLIST_NODE(&new_f->fn_hash);
+		INIT_LIST_HEAD(&new_f->fn_alias);
+		new_f->fn_key = key;
+		f = new_f;
+	}
+
+	new_fa = &f->fn_embedded_alias;
+	if (new_fa->fa_info != NULL) {
+		new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+		if (new_fa == NULL)
+			goto out;
+	}
+	new_fa->fa_info = fi;
+	new_fa->fa_tos = tos;
+	new_fa->fa_type = cfg->fc_type;
+	new_fa->fa_scope = cfg->fc_scope;
+	new_fa->fa_state = 0;
+
+	/*
+	 * Insert new entry to the list.
+	 */
+
+	write_lock_bh(&fib_hash_lock);
+	if (new_f)
+		fib_insert_node(fz, new_f);
+	list_add_tail(&new_fa->fa_list,
+		 (fa ? &fa->fa_list : &f->fn_alias));
+	fib_hash_genid++;
+	write_unlock_bh(&fib_hash_lock);
+
+	if (new_f)
+		fz->fz_nent++;
+	rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+
+	rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
+		  &cfg->fc_nlinfo, 0);
+	return 0;
+
+out:
+	if (new_f)
+		kmem_cache_free(fn_hash_kmem, new_f);
+	fib_release_info(fi);
+	return err;
+}
+
+
+static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
+{
+	struct fn_hash *table = (struct fn_hash*)tb->tb_data;
+	struct fib_node *f;
+	struct fib_alias *fa, *fa_to_delete;
+	struct fn_zone *fz;
+	__be32 key;
+
+	if (cfg->fc_dst_len > 32)
+		return -EINVAL;
+
+	if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
+		return -ESRCH;
+
+	key = 0;
+	if (cfg->fc_dst) {
+		if (cfg->fc_dst & ~FZ_MASK(fz))
+			return -EINVAL;
+		key = fz_key(cfg->fc_dst, fz);
+	}
+
+	f = fib_find_node(fz, key);
+
+	if (!f)
+		fa = NULL;
+	else
+		fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
+	if (!fa)
+		return -ESRCH;
+
+	fa_to_delete = NULL;
+	fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+	list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
+		struct fib_info *fi = fa->fa_info;
+
+		if (fa->fa_tos != cfg->fc_tos)
+			break;
+
+		if ((!cfg->fc_type ||
+		     fa->fa_type == cfg->fc_type) &&
+		    (cfg->fc_scope == RT_SCOPE_NOWHERE ||
+		     fa->fa_scope == cfg->fc_scope) &&
+		    (!cfg->fc_protocol ||
+		     fi->fib_protocol == cfg->fc_protocol) &&
+		    fib_nh_match(cfg, fi) == 0) {
+			fa_to_delete = fa;
+			break;
+		}
+	}
+
+	if (fa_to_delete) {
+		int kill_fn;
+
+		fa = fa_to_delete;
+		rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
+			  tb->tb_id, &cfg->fc_nlinfo, 0);
+
+		kill_fn = 0;
+		write_lock_bh(&fib_hash_lock);
+		list_del(&fa->fa_list);
+		if (list_empty(&f->fn_alias)) {
+			hlist_del(&f->fn_hash);
+			kill_fn = 1;
+		}
+		fib_hash_genid++;
+		write_unlock_bh(&fib_hash_lock);
+
+		if (fa->fa_state & FA_S_ACCESSED)
+			rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+		fn_free_alias(fa, f);
+		if (kill_fn) {
+			fn_free_node(f);
+			fz->fz_nent--;
+		}
+
+		return 0;
+	}
+	return -ESRCH;
+}
+
+static int fn_flush_list(struct fn_zone *fz, int idx)
+{
+	struct hlist_head *head = &fz->fz_hash[idx];
+	struct hlist_node *node, *n;
+	struct fib_node *f;
+	int found = 0;
+
+	hlist_for_each_entry_safe(f, node, n, head, fn_hash) {
+		struct fib_alias *fa, *fa_node;
+		int kill_f;
+
+		kill_f = 0;
+		list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) {
+			struct fib_info *fi = fa->fa_info;
+
+			if (fi && (fi->fib_flags&RTNH_F_DEAD)) {
+				write_lock_bh(&fib_hash_lock);
+				list_del(&fa->fa_list);
+				if (list_empty(&f->fn_alias)) {
+					hlist_del(&f->fn_hash);
+					kill_f = 1;
+				}
+				fib_hash_genid++;
+				write_unlock_bh(&fib_hash_lock);
+
+				fn_free_alias(fa, f);
+				found++;
+			}
+		}
+		if (kill_f) {
+			fn_free_node(f);
+			fz->fz_nent--;
+		}
+	}
+	return found;
+}
+
+static int fn_hash_flush(struct fib_table *tb)
+{
+	struct fn_hash *table = (struct fn_hash *) tb->tb_data;
+	struct fn_zone *fz;
+	int found = 0;
+
+	for (fz = table->fn_zone_list; fz; fz = fz->fz_next) {
+		int i;
+
+		for (i = fz->fz_divisor - 1; i >= 0; i--)
+			found += fn_flush_list(fz, i);
+	}
+	return found;
+}
+
+
+static inline int
+fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb,
+		     struct fib_table *tb,
+		     struct fn_zone *fz,
+		     struct hlist_head *head)
+{
+	struct hlist_node *node;
+	struct fib_node *f;
+	int i, s_i;
+
+	s_i = cb->args[4];
+	i = 0;
+	hlist_for_each_entry(f, node, head, fn_hash) {
+		struct fib_alias *fa;
+
+		list_for_each_entry(fa, &f->fn_alias, fa_list) {
+			if (i < s_i)
+				goto next;
+
+			if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
+					  cb->nlh->nlmsg_seq,
+					  RTM_NEWROUTE,
+					  tb->tb_id,
+					  fa->fa_type,
+					  fa->fa_scope,
+					  f->fn_key,
+					  fz->fz_order,
+					  fa->fa_tos,
+					  fa->fa_info,
+					  NLM_F_MULTI) < 0) {
+				cb->args[4] = i;
+				return -1;
+			}
+		next:
+			i++;
+		}
+	}
+	cb->args[4] = i;
+	return skb->len;
+}
+
+static inline int
+fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb,
+		   struct fib_table *tb,
+		   struct fn_zone *fz)
+{
+	int h, s_h;
+
+	if (fz->fz_hash == NULL)
+		return skb->len;
+	s_h = cb->args[3];
+	for (h = s_h; h < fz->fz_divisor; h++) {
+		if (hlist_empty(&fz->fz_hash[h]))
+			continue;
+		if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) {
+			cb->args[3] = h;
+			return -1;
+		}
+		memset(&cb->args[4], 0,
+		       sizeof(cb->args) - 4*sizeof(cb->args[0]));
+	}
+	cb->args[3] = h;
+	return skb->len;
+}
+
+static int fn_hash_dump(struct fib_table *tb, struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int m, s_m;
+	struct fn_zone *fz;
+	struct fn_hash *table = (struct fn_hash*)tb->tb_data;
+
+	s_m = cb->args[2];
+	read_lock(&fib_hash_lock);
+	for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) {
+		if (m < s_m) continue;
+		if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) {
+			cb->args[2] = m;
+			read_unlock(&fib_hash_lock);
+			return -1;
+		}
+		memset(&cb->args[3], 0,
+		       sizeof(cb->args) - 3*sizeof(cb->args[0]));
+	}
+	read_unlock(&fib_hash_lock);
+	cb->args[2] = m;
+	return skb->len;
+}
+
+void __init fib_hash_init(void)
+{
+	fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node),
+					 0, SLAB_PANIC, NULL);
+
+	fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias),
+					  0, SLAB_PANIC, NULL);
+
+}
+
+struct fib_table *fib_hash_table(u32 id)
+{
+	struct fib_table *tb;
+
+	tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash),
+		     GFP_KERNEL);
+	if (tb == NULL)
+		return NULL;
+
+	tb->tb_id = id;
+	tb->tb_default = -1;
+	tb->tb_lookup = fn_hash_lookup;
+	tb->tb_insert = fn_hash_insert;
+	tb->tb_delete = fn_hash_delete;
+	tb->tb_flush = fn_hash_flush;
+	tb->tb_select_default = fn_hash_select_default;
+	tb->tb_dump = fn_hash_dump;
+	memset(tb->tb_data, 0, sizeof(struct fn_hash));
+	return tb;
+}
+
+/* ------------------------------------------------------------------------ */
+#ifdef CONFIG_PROC_FS
+
+struct fib_iter_state {
+	struct seq_net_private p;
+	struct fn_zone	*zone;
+	int		bucket;
+	struct hlist_head *hash_head;
+	struct fib_node *fn;
+	struct fib_alias *fa;
+	loff_t pos;
+	unsigned int genid;
+	int valid;
+};
+
+static struct fib_alias *fib_get_first(struct seq_file *seq)
+{
+	struct fib_iter_state *iter = seq->private;
+	struct fib_table *main_table;
+	struct fn_hash *table;
+
+	main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
+	table = (struct fn_hash *)main_table->tb_data;
+
+	iter->bucket    = 0;
+	iter->hash_head = NULL;
+	iter->fn        = NULL;
+	iter->fa        = NULL;
+	iter->pos	= 0;
+	iter->genid	= fib_hash_genid;
+	iter->valid	= 1;
+
+	for (iter->zone = table->fn_zone_list; iter->zone;
+	     iter->zone = iter->zone->fz_next) {
+		int maxslot;
+
+		if (!iter->zone->fz_nent)
+			continue;
+
+		iter->hash_head = iter->zone->fz_hash;
+		maxslot = iter->zone->fz_divisor;
+
+		for (iter->bucket = 0; iter->bucket < maxslot;
+		     ++iter->bucket, ++iter->hash_head) {
+			struct hlist_node *node;
+			struct fib_node *fn;
+
+			hlist_for_each_entry(fn,node,iter->hash_head,fn_hash) {
+				struct fib_alias *fa;
+
+				list_for_each_entry(fa,&fn->fn_alias,fa_list) {
+					iter->fn = fn;
+					iter->fa = fa;
+					goto out;
+				}
+			}
+		}
+	}
+out:
+	return iter->fa;
+}
+
+static struct fib_alias *fib_get_next(struct seq_file *seq)
+{
+	struct fib_iter_state *iter = seq->private;
+	struct fib_node *fn;
+	struct fib_alias *fa;
+
+	/* Advance FA, if any. */
+	fn = iter->fn;
+	fa = iter->fa;
+	if (fa) {
+		BUG_ON(!fn);
+		list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) {
+			iter->fa = fa;
+			goto out;
+		}
+	}
+
+	fa = iter->fa = NULL;
+
+	/* Advance FN. */
+	if (fn) {
+		struct hlist_node *node = &fn->fn_hash;
+		hlist_for_each_entry_continue(fn, node, fn_hash) {
+			iter->fn = fn;
+
+			list_for_each_entry(fa, &fn->fn_alias, fa_list) {
+				iter->fa = fa;
+				goto out;
+			}
+		}
+	}
+
+	fn = iter->fn = NULL;
+
+	/* Advance hash chain. */
+	if (!iter->zone)
+		goto out;
+
+	for (;;) {
+		struct hlist_node *node;
+		int maxslot;
+
+		maxslot = iter->zone->fz_divisor;
+
+		while (++iter->bucket < maxslot) {
+			iter->hash_head++;
+
+			hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
+				list_for_each_entry(fa, &fn->fn_alias, fa_list) {
+					iter->fn = fn;
+					iter->fa = fa;
+					goto out;
+				}
+			}
+		}
+
+		iter->zone = iter->zone->fz_next;
+
+		if (!iter->zone)
+			goto out;
+
+		iter->bucket = 0;
+		iter->hash_head = iter->zone->fz_hash;
+
+		hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) {
+			list_for_each_entry(fa, &fn->fn_alias, fa_list) {
+				iter->fn = fn;
+				iter->fa = fa;
+				goto out;
+			}
+		}
+	}
+out:
+	iter->pos++;
+	return fa;
+}
+
+static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct fib_iter_state *iter = seq->private;
+	struct fib_alias *fa;
+
+	if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) {
+		fa   = iter->fa;
+		pos -= iter->pos;
+	} else
+		fa = fib_get_first(seq);
+
+	if (fa)
+		while (pos && (fa = fib_get_next(seq)))
+			--pos;
+	return pos ? NULL : fa;
+}
+
+static void *fib_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(fib_hash_lock)
+{
+	void *v = NULL;
+
+	read_lock(&fib_hash_lock);
+	if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN))
+		v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+	return v;
+}
+
+static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	++*pos;
+	return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq);
+}
+
+static void fib_seq_stop(struct seq_file *seq, void *v)
+	__releases(fib_hash_lock)
+{
+	read_unlock(&fib_hash_lock);
+}
+
+static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi)
+{
+	static const unsigned type2flags[RTN_MAX + 1] = {
+		[7] = RTF_REJECT, [8] = RTF_REJECT,
+	};
+	unsigned flags = type2flags[type];
+
+	if (fi && fi->fib_nh->nh_gw)
+		flags |= RTF_GATEWAY;
+	if (mask == htonl(0xFFFFFFFF))
+		flags |= RTF_HOST;
+	flags |= RTF_UP;
+	return flags;
+}
+
+/*
+ *	This outputs /proc/net/route.
+ *
+ *	It always works in backward compatibility mode.
+ *	The format of the file is not supposed to be changed.
+ */
+static int fib_seq_show(struct seq_file *seq, void *v)
+{
+	struct fib_iter_state *iter;
+	int len;
+	__be32 prefix, mask;
+	unsigned flags;
+	struct fib_node *f;
+	struct fib_alias *fa;
+	struct fib_info *fi;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
+			   "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
+			   "\tWindow\tIRTT");
+		goto out;
+	}
+
+	iter	= seq->private;
+	f	= iter->fn;
+	fa	= iter->fa;
+	fi	= fa->fa_info;
+	prefix	= f->fn_key;
+	mask	= FZ_MASK(iter->zone);
+	flags	= fib_flag_trans(fa->fa_type, mask, fi);
+	if (fi)
+		seq_printf(seq,
+			 "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
+			 fi->fib_dev ? fi->fib_dev->name : "*", prefix,
+			 fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority,
+			 mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0),
+			 fi->fib_window,
+			 fi->fib_rtt >> 3, &len);
+	else
+		seq_printf(seq,
+			 "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n",
+			 prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len);
+
+	seq_printf(seq, "%*s\n", 127 - len, "");
+out:
+	return 0;
+}
+
+static const struct seq_operations fib_seq_ops = {
+	.start  = fib_seq_start,
+	.next   = fib_seq_next,
+	.stop   = fib_seq_stop,
+	.show   = fib_seq_show,
+};
+
+static int fib_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &fib_seq_ops,
+			    sizeof(struct fib_iter_state));
+}
+
+static const struct file_operations fib_seq_fops = {
+	.owner		= THIS_MODULE,
+	.open           = fib_seq_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release	= seq_release_net,
+};
+
+int __net_init fib_proc_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops))
+		return -ENOMEM;
+	return 0;
+}
+
+void __net_exit fib_proc_exit(struct net *net)
+{
+	proc_net_remove(net, "route");
+}
+#endif /* CONFIG_PROC_FS */
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
new file mode 100644
index 0000000..2c1623d
--- /dev/null
+++ b/net/ipv4/fib_lookup.h
@@ -0,0 +1,53 @@
+#ifndef _FIB_LOOKUP_H
+#define _FIB_LOOKUP_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <net/ip_fib.h>
+
+struct fib_alias {
+	struct list_head	fa_list;
+	struct fib_info		*fa_info;
+	u8			fa_tos;
+	u8			fa_type;
+	u8			fa_scope;
+	u8			fa_state;
+#ifdef CONFIG_IP_FIB_TRIE
+	struct rcu_head		rcu;
+#endif
+};
+
+#define FA_S_ACCESSED	0x01
+
+/* Exported by fib_semantics.c */
+extern int fib_semantic_match(struct list_head *head,
+			      const struct flowi *flp,
+			      struct fib_result *res, __be32 zone, __be32 mask,
+				int prefixlen);
+extern void fib_release_info(struct fib_info *);
+extern struct fib_info *fib_create_info(struct fib_config *cfg);
+extern int fib_nh_match(struct fib_config *cfg, struct fib_info *fi);
+extern int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
+			 u32 tb_id, u8 type, u8 scope, __be32 dst,
+			 int dst_len, u8 tos, struct fib_info *fi,
+			 unsigned int);
+extern void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
+		      int dst_len, u32 tb_id, struct nl_info *info,
+		      unsigned int nlm_flags);
+extern struct fib_alias *fib_find_alias(struct list_head *fah,
+					u8 tos, u32 prio);
+extern int fib_detect_death(struct fib_info *fi, int order,
+			    struct fib_info **last_resort,
+			    int *last_idx, int dflt);
+
+static inline void fib_result_assign(struct fib_result *res,
+				     struct fib_info *fi)
+{
+	if (res->fi != NULL)
+		fib_info_put(res->fi);
+	res->fi = fi;
+	if (fi != NULL)
+		atomic_inc(&fi->fib_clntref);
+}
+
+#endif /* _FIB_LOOKUP_H */
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
new file mode 100644
index 0000000..6080d71
--- /dev/null
+++ b/net/ipv4/fib_rules.c
@@ -0,0 +1,329 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 Forwarding Information Base: policy rules.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ * 		Thomas Graf <tgraf@suug.ch>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Fixes:
+ * 		Rani Assaf	:	local_rule cannot be deleted
+ *		Marc Boucher	:	routing by fwmark
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/netlink.h>
+#include <linux/inetdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/ip_fib.h>
+#include <net/fib_rules.h>
+
+struct fib4_rule
+{
+	struct fib_rule		common;
+	u8			dst_len;
+	u8			src_len;
+	u8			tos;
+	__be32			src;
+	__be32			srcmask;
+	__be32			dst;
+	__be32			dstmask;
+#ifdef CONFIG_NET_CLS_ROUTE
+	u32			tclassid;
+#endif
+};
+
+#ifdef CONFIG_NET_CLS_ROUTE
+u32 fib_rules_tclass(struct fib_result *res)
+{
+	return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
+}
+#endif
+
+int fib_lookup(struct net *net, struct flowi *flp, struct fib_result *res)
+{
+	struct fib_lookup_arg arg = {
+		.result = res,
+	};
+	int err;
+
+	err = fib_rules_lookup(net->ipv4.rules_ops, flp, 0, &arg);
+	res->r = arg.rule;
+
+	return err;
+}
+
+static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
+			    int flags, struct fib_lookup_arg *arg)
+{
+	int err = -EAGAIN;
+	struct fib_table *tbl;
+
+	switch (rule->action) {
+	case FR_ACT_TO_TBL:
+		break;
+
+	case FR_ACT_UNREACHABLE:
+		err = -ENETUNREACH;
+		goto errout;
+
+	case FR_ACT_PROHIBIT:
+		err = -EACCES;
+		goto errout;
+
+	case FR_ACT_BLACKHOLE:
+	default:
+		err = -EINVAL;
+		goto errout;
+	}
+
+	if ((tbl = fib_get_table(rule->fr_net, rule->table)) == NULL)
+		goto errout;
+
+	err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
+	if (err > 0)
+		err = -EAGAIN;
+errout:
+	return err;
+}
+
+
+static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
+{
+	struct fib4_rule *r = (struct fib4_rule *) rule;
+	__be32 daddr = fl->fl4_dst;
+	__be32 saddr = fl->fl4_src;
+
+	if (((saddr ^ r->src) & r->srcmask) ||
+	    ((daddr ^ r->dst) & r->dstmask))
+		return 0;
+
+	if (r->tos && (r->tos != fl->fl4_tos))
+		return 0;
+
+	return 1;
+}
+
+static struct fib_table *fib_empty_table(struct net *net)
+{
+	u32 id;
+
+	for (id = 1; id <= RT_TABLE_MAX; id++)
+		if (fib_get_table(net, id) == NULL)
+			return fib_new_table(net, id);
+	return NULL;
+}
+
+static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
+	FRA_GENERIC_POLICY,
+	[FRA_FLOW]	= { .type = NLA_U32 },
+};
+
+static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
+			       struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
+			       struct nlattr **tb)
+{
+	struct net *net = sock_net(skb->sk);
+	int err = -EINVAL;
+	struct fib4_rule *rule4 = (struct fib4_rule *) rule;
+
+	if (frh->tos & ~IPTOS_TOS_MASK)
+		goto errout;
+
+	if (rule->table == RT_TABLE_UNSPEC) {
+		if (rule->action == FR_ACT_TO_TBL) {
+			struct fib_table *table;
+
+			table = fib_empty_table(net);
+			if (table == NULL) {
+				err = -ENOBUFS;
+				goto errout;
+			}
+
+			rule->table = table->tb_id;
+		}
+	}
+
+	if (frh->src_len)
+		rule4->src = nla_get_be32(tb[FRA_SRC]);
+
+	if (frh->dst_len)
+		rule4->dst = nla_get_be32(tb[FRA_DST]);
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (tb[FRA_FLOW])
+		rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
+#endif
+
+	rule4->src_len = frh->src_len;
+	rule4->srcmask = inet_make_mask(rule4->src_len);
+	rule4->dst_len = frh->dst_len;
+	rule4->dstmask = inet_make_mask(rule4->dst_len);
+	rule4->tos = frh->tos;
+
+	err = 0;
+errout:
+	return err;
+}
+
+static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
+			     struct nlattr **tb)
+{
+	struct fib4_rule *rule4 = (struct fib4_rule *) rule;
+
+	if (frh->src_len && (rule4->src_len != frh->src_len))
+		return 0;
+
+	if (frh->dst_len && (rule4->dst_len != frh->dst_len))
+		return 0;
+
+	if (frh->tos && (rule4->tos != frh->tos))
+		return 0;
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
+		return 0;
+#endif
+
+	if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
+		return 0;
+
+	if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
+		return 0;
+
+	return 1;
+}
+
+static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
+			  struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
+{
+	struct fib4_rule *rule4 = (struct fib4_rule *) rule;
+
+	frh->family = AF_INET;
+	frh->dst_len = rule4->dst_len;
+	frh->src_len = rule4->src_len;
+	frh->tos = rule4->tos;
+
+	if (rule4->dst_len)
+		NLA_PUT_BE32(skb, FRA_DST, rule4->dst);
+
+	if (rule4->src_len)
+		NLA_PUT_BE32(skb, FRA_SRC, rule4->src);
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (rule4->tclassid)
+		NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
+#endif
+	return 0;
+
+nla_put_failure:
+	return -ENOBUFS;
+}
+
+static u32 fib4_rule_default_pref(struct fib_rules_ops *ops)
+{
+	struct list_head *pos;
+	struct fib_rule *rule;
+
+	if (!list_empty(&ops->rules_list)) {
+		pos = ops->rules_list.next;
+		if (pos->next != &ops->rules_list) {
+			rule = list_entry(pos->next, struct fib_rule, list);
+			if (rule->pref)
+				return rule->pref - 1;
+		}
+	}
+
+	return 0;
+}
+
+static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
+{
+	return nla_total_size(4) /* dst */
+	       + nla_total_size(4) /* src */
+	       + nla_total_size(4); /* flow */
+}
+
+static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
+{
+	rt_cache_flush(ops->fro_net, -1);
+}
+
+static struct fib_rules_ops fib4_rules_ops_template = {
+	.family		= AF_INET,
+	.rule_size	= sizeof(struct fib4_rule),
+	.addr_size	= sizeof(u32),
+	.action		= fib4_rule_action,
+	.match		= fib4_rule_match,
+	.configure	= fib4_rule_configure,
+	.compare	= fib4_rule_compare,
+	.fill		= fib4_rule_fill,
+	.default_pref	= fib4_rule_default_pref,
+	.nlmsg_payload	= fib4_rule_nlmsg_payload,
+	.flush_cache	= fib4_rule_flush_cache,
+	.nlgroup	= RTNLGRP_IPV4_RULE,
+	.policy		= fib4_rule_policy,
+	.owner		= THIS_MODULE,
+};
+
+static int fib_default_rules_init(struct fib_rules_ops *ops)
+{
+	int err;
+
+	err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, FIB_RULE_PERMANENT);
+	if (err < 0)
+		return err;
+	err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
+	if (err < 0)
+		return err;
+	err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
+	if (err < 0)
+		return err;
+	return 0;
+}
+
+int __net_init fib4_rules_init(struct net *net)
+{
+	int err;
+	struct fib_rules_ops *ops;
+
+	ops = kmemdup(&fib4_rules_ops_template, sizeof(*ops), GFP_KERNEL);
+	if (ops == NULL)
+		return -ENOMEM;
+	INIT_LIST_HEAD(&ops->rules_list);
+	ops->fro_net = net;
+
+	fib_rules_register(ops);
+
+	err = fib_default_rules_init(ops);
+	if (err < 0)
+		goto fail;
+	net->ipv4.rules_ops = ops;
+	return 0;
+
+fail:
+	/* also cleans all rules already added */
+	fib_rules_unregister(ops);
+	kfree(ops);
+	return err;
+}
+
+void __net_exit fib4_rules_exit(struct net *net)
+{
+	fib_rules_unregister(net->ipv4.rules_ops);
+	kfree(net->ipv4.rules_ops);
+}
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
new file mode 100644
index 0000000..ded2ae3
--- /dev/null
+++ b/net/ipv4/fib_semantics.c
@@ -0,0 +1,1222 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 Forwarding Information Base: semantics.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+
+#include <net/arp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+#include <net/netlink.h>
+#include <net/nexthop.h>
+
+#include "fib_lookup.h"
+
+static DEFINE_SPINLOCK(fib_info_lock);
+static struct hlist_head *fib_info_hash;
+static struct hlist_head *fib_info_laddrhash;
+static unsigned int fib_hash_size;
+static unsigned int fib_info_cnt;
+
+#define DEVINDEX_HASHBITS 8
+#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
+static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+
+static DEFINE_SPINLOCK(fib_multipath_lock);
+
+#define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \
+for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
+
+#define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \
+for (nhsel=0, nh = (struct fib_nh*)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
+
+#else /* CONFIG_IP_ROUTE_MULTIPATH */
+
+/* Hope, that gcc will optimize it to get rid of dummy loop */
+
+#define for_nexthops(fi) { int nhsel=0; const struct fib_nh * nh = (fi)->fib_nh; \
+for (nhsel=0; nhsel < 1; nhsel++)
+
+#define change_nexthops(fi) { int nhsel=0; struct fib_nh * nh = (struct fib_nh*)((fi)->fib_nh); \
+for (nhsel=0; nhsel < 1; nhsel++)
+
+#endif /* CONFIG_IP_ROUTE_MULTIPATH */
+
+#define endfor_nexthops(fi) }
+
+
+static const struct
+{
+	int	error;
+	u8	scope;
+} fib_props[RTN_MAX + 1] = {
+	{
+		.error	= 0,
+		.scope	= RT_SCOPE_NOWHERE,
+	},	/* RTN_UNSPEC */
+	{
+		.error	= 0,
+		.scope	= RT_SCOPE_UNIVERSE,
+	},	/* RTN_UNICAST */
+	{
+		.error	= 0,
+		.scope	= RT_SCOPE_HOST,
+	},	/* RTN_LOCAL */
+	{
+		.error	= 0,
+		.scope	= RT_SCOPE_LINK,
+	},	/* RTN_BROADCAST */
+	{
+		.error	= 0,
+		.scope	= RT_SCOPE_LINK,
+	},	/* RTN_ANYCAST */
+	{
+		.error	= 0,
+		.scope	= RT_SCOPE_UNIVERSE,
+	},	/* RTN_MULTICAST */
+	{
+		.error	= -EINVAL,
+		.scope	= RT_SCOPE_UNIVERSE,
+	},	/* RTN_BLACKHOLE */
+	{
+		.error	= -EHOSTUNREACH,
+		.scope	= RT_SCOPE_UNIVERSE,
+	},	/* RTN_UNREACHABLE */
+	{
+		.error	= -EACCES,
+		.scope	= RT_SCOPE_UNIVERSE,
+	},	/* RTN_PROHIBIT */
+	{
+		.error	= -EAGAIN,
+		.scope	= RT_SCOPE_UNIVERSE,
+	},	/* RTN_THROW */
+	{
+		.error	= -EINVAL,
+		.scope	= RT_SCOPE_NOWHERE,
+	},	/* RTN_NAT */
+	{
+		.error	= -EINVAL,
+		.scope	= RT_SCOPE_NOWHERE,
+	},	/* RTN_XRESOLVE */
+};
+
+
+/* Release a nexthop info record */
+
+void free_fib_info(struct fib_info *fi)
+{
+	if (fi->fib_dead == 0) {
+		printk(KERN_WARNING "Freeing alive fib_info %p\n", fi);
+		return;
+	}
+	change_nexthops(fi) {
+		if (nh->nh_dev)
+			dev_put(nh->nh_dev);
+		nh->nh_dev = NULL;
+	} endfor_nexthops(fi);
+	fib_info_cnt--;
+	release_net(fi->fib_net);
+	kfree(fi);
+}
+
+void fib_release_info(struct fib_info *fi)
+{
+	spin_lock_bh(&fib_info_lock);
+	if (fi && --fi->fib_treeref == 0) {
+		hlist_del(&fi->fib_hash);
+		if (fi->fib_prefsrc)
+			hlist_del(&fi->fib_lhash);
+		change_nexthops(fi) {
+			if (!nh->nh_dev)
+				continue;
+			hlist_del(&nh->nh_hash);
+		} endfor_nexthops(fi)
+		fi->fib_dead = 1;
+		fib_info_put(fi);
+	}
+	spin_unlock_bh(&fib_info_lock);
+}
+
+static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
+{
+	const struct fib_nh *onh = ofi->fib_nh;
+
+	for_nexthops(fi) {
+		if (nh->nh_oif != onh->nh_oif ||
+		    nh->nh_gw  != onh->nh_gw ||
+		    nh->nh_scope != onh->nh_scope ||
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+		    nh->nh_weight != onh->nh_weight ||
+#endif
+#ifdef CONFIG_NET_CLS_ROUTE
+		    nh->nh_tclassid != onh->nh_tclassid ||
+#endif
+		    ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
+			return -1;
+		onh++;
+	} endfor_nexthops(fi);
+	return 0;
+}
+
+static inline unsigned int fib_devindex_hashfn(unsigned int val)
+{
+	unsigned int mask = DEVINDEX_HASHSIZE - 1;
+
+	return (val ^
+		(val >> DEVINDEX_HASHBITS) ^
+		(val >> (DEVINDEX_HASHBITS * 2))) & mask;
+}
+
+static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
+{
+	unsigned int mask = (fib_hash_size - 1);
+	unsigned int val = fi->fib_nhs;
+
+	val ^= fi->fib_protocol;
+	val ^= (__force u32)fi->fib_prefsrc;
+	val ^= fi->fib_priority;
+	for_nexthops(fi) {
+		val ^= fib_devindex_hashfn(nh->nh_oif);
+	} endfor_nexthops(fi)
+
+	return (val ^ (val >> 7) ^ (val >> 12)) & mask;
+}
+
+static struct fib_info *fib_find_info(const struct fib_info *nfi)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct fib_info *fi;
+	unsigned int hash;
+
+	hash = fib_info_hashfn(nfi);
+	head = &fib_info_hash[hash];
+
+	hlist_for_each_entry(fi, node, head, fib_hash) {
+		if (fi->fib_net != nfi->fib_net)
+			continue;
+		if (fi->fib_nhs != nfi->fib_nhs)
+			continue;
+		if (nfi->fib_protocol == fi->fib_protocol &&
+		    nfi->fib_prefsrc == fi->fib_prefsrc &&
+		    nfi->fib_priority == fi->fib_priority &&
+		    memcmp(nfi->fib_metrics, fi->fib_metrics,
+			   sizeof(fi->fib_metrics)) == 0 &&
+		    ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
+		    (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
+			return fi;
+	}
+
+	return NULL;
+}
+
+/* Check, that the gateway is already configured.
+   Used only by redirect accept routine.
+ */
+
+int ip_fib_check_default(__be32 gw, struct net_device *dev)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct fib_nh *nh;
+	unsigned int hash;
+
+	spin_lock(&fib_info_lock);
+
+	hash = fib_devindex_hashfn(dev->ifindex);
+	head = &fib_info_devhash[hash];
+	hlist_for_each_entry(nh, node, head, nh_hash) {
+		if (nh->nh_dev == dev &&
+		    nh->nh_gw == gw &&
+		    !(nh->nh_flags&RTNH_F_DEAD)) {
+			spin_unlock(&fib_info_lock);
+			return 0;
+		}
+	}
+
+	spin_unlock(&fib_info_lock);
+
+	return -1;
+}
+
+static inline size_t fib_nlmsg_size(struct fib_info *fi)
+{
+	size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
+			 + nla_total_size(4) /* RTA_TABLE */
+			 + nla_total_size(4) /* RTA_DST */
+			 + nla_total_size(4) /* RTA_PRIORITY */
+			 + nla_total_size(4); /* RTA_PREFSRC */
+
+	/* space for nested metrics */
+	payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
+
+	if (fi->fib_nhs) {
+		/* Also handles the special case fib_nhs == 1 */
+
+		/* each nexthop is packed in an attribute */
+		size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
+
+		/* may contain flow and gateway attribute */
+		nhsize += 2 * nla_total_size(4);
+
+		/* all nexthops are packed in a nested attribute */
+		payload += nla_total_size(fi->fib_nhs * nhsize);
+	}
+
+	return payload;
+}
+
+void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
+	       int dst_len, u32 tb_id, struct nl_info *info,
+	       unsigned int nlm_flags)
+{
+	struct sk_buff *skb;
+	u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+	int err = -ENOBUFS;
+
+	skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
+	if (skb == NULL)
+		goto errout;
+
+	err = fib_dump_info(skb, info->pid, seq, event, tb_id,
+			    fa->fa_type, fa->fa_scope, key, dst_len,
+			    fa->fa_tos, fa->fa_info, nlm_flags);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in fib_nlmsg_size() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+	err = rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE,
+			  info->nlh, GFP_KERNEL);
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
+}
+
+/* Return the first fib alias matching TOS with
+ * priority less than or equal to PRIO.
+ */
+struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
+{
+	if (fah) {
+		struct fib_alias *fa;
+		list_for_each_entry(fa, fah, fa_list) {
+			if (fa->fa_tos > tos)
+				continue;
+			if (fa->fa_info->fib_priority >= prio ||
+			    fa->fa_tos < tos)
+				return fa;
+		}
+	}
+	return NULL;
+}
+
+int fib_detect_death(struct fib_info *fi, int order,
+		     struct fib_info **last_resort, int *last_idx, int dflt)
+{
+	struct neighbour *n;
+	int state = NUD_NONE;
+
+	n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev);
+	if (n) {
+		state = n->nud_state;
+		neigh_release(n);
+	}
+	if (state==NUD_REACHABLE)
+		return 0;
+	if ((state&NUD_VALID) && order != dflt)
+		return 0;
+	if ((state&NUD_VALID) ||
+	    (*last_idx<0 && order > dflt)) {
+		*last_resort = fi;
+		*last_idx = order;
+	}
+	return 1;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+
+static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining)
+{
+	int nhs = 0;
+
+	while (rtnh_ok(rtnh, remaining)) {
+		nhs++;
+		rtnh = rtnh_next(rtnh, &remaining);
+	}
+
+	/* leftover implies invalid nexthop configuration, discard it */
+	return remaining > 0 ? 0 : nhs;
+}
+
+static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
+		       int remaining, struct fib_config *cfg)
+{
+	change_nexthops(fi) {
+		int attrlen;
+
+		if (!rtnh_ok(rtnh, remaining))
+			return -EINVAL;
+
+		nh->nh_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
+		nh->nh_oif = rtnh->rtnh_ifindex;
+		nh->nh_weight = rtnh->rtnh_hops + 1;
+
+		attrlen = rtnh_attrlen(rtnh);
+		if (attrlen > 0) {
+			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
+
+			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
+			nh->nh_gw = nla ? nla_get_be32(nla) : 0;
+#ifdef CONFIG_NET_CLS_ROUTE
+			nla = nla_find(attrs, attrlen, RTA_FLOW);
+			nh->nh_tclassid = nla ? nla_get_u32(nla) : 0;
+#endif
+		}
+
+		rtnh = rtnh_next(rtnh, &remaining);
+	} endfor_nexthops(fi);
+
+	return 0;
+}
+
+#endif
+
+int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
+{
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	struct rtnexthop *rtnh;
+	int remaining;
+#endif
+
+	if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
+		return 1;
+
+	if (cfg->fc_oif || cfg->fc_gw) {
+		if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
+		    (!cfg->fc_gw  || cfg->fc_gw == fi->fib_nh->nh_gw))
+			return 0;
+		return 1;
+	}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	if (cfg->fc_mp == NULL)
+		return 0;
+
+	rtnh = cfg->fc_mp;
+	remaining = cfg->fc_mp_len;
+
+	for_nexthops(fi) {
+		int attrlen;
+
+		if (!rtnh_ok(rtnh, remaining))
+			return -EINVAL;
+
+		if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif)
+			return 1;
+
+		attrlen = rtnh_attrlen(rtnh);
+		if (attrlen < 0) {
+			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
+
+			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
+			if (nla && nla_get_be32(nla) != nh->nh_gw)
+				return 1;
+#ifdef CONFIG_NET_CLS_ROUTE
+			nla = nla_find(attrs, attrlen, RTA_FLOW);
+			if (nla && nla_get_u32(nla) != nh->nh_tclassid)
+				return 1;
+#endif
+		}
+
+		rtnh = rtnh_next(rtnh, &remaining);
+	} endfor_nexthops(fi);
+#endif
+	return 0;
+}
+
+
+/*
+   Picture
+   -------
+
+   Semantics of nexthop is very messy by historical reasons.
+   We have to take into account, that:
+   a) gateway can be actually local interface address,
+      so that gatewayed route is direct.
+   b) gateway must be on-link address, possibly
+      described not by an ifaddr, but also by a direct route.
+   c) If both gateway and interface are specified, they should not
+      contradict.
+   d) If we use tunnel routes, gateway could be not on-link.
+
+   Attempt to reconcile all of these (alas, self-contradictory) conditions
+   results in pretty ugly and hairy code with obscure logic.
+
+   I chose to generalized it instead, so that the size
+   of code does not increase practically, but it becomes
+   much more general.
+   Every prefix is assigned a "scope" value: "host" is local address,
+   "link" is direct route,
+   [ ... "site" ... "interior" ... ]
+   and "universe" is true gateway route with global meaning.
+
+   Every prefix refers to a set of "nexthop"s (gw, oif),
+   where gw must have narrower scope. This recursion stops
+   when gw has LOCAL scope or if "nexthop" is declared ONLINK,
+   which means that gw is forced to be on link.
+
+   Code is still hairy, but now it is apparently logically
+   consistent and very flexible. F.e. as by-product it allows
+   to co-exists in peace independent exterior and interior
+   routing processes.
+
+   Normally it looks as following.
+
+   {universe prefix}  -> (gw, oif) [scope link]
+			  |
+			  |-> {link prefix} -> (gw, oif) [scope local]
+						|
+						|-> {local prefix} (terminal node)
+ */
+
+static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
+			struct fib_nh *nh)
+{
+	int err;
+	struct net *net;
+
+	net = cfg->fc_nlinfo.nl_net;
+	if (nh->nh_gw) {
+		struct fib_result res;
+
+#ifdef CONFIG_IP_ROUTE_PERVASIVE
+		if (nh->nh_flags&RTNH_F_PERVASIVE)
+			return 0;
+#endif
+		if (nh->nh_flags&RTNH_F_ONLINK) {
+			struct net_device *dev;
+
+			if (cfg->fc_scope >= RT_SCOPE_LINK)
+				return -EINVAL;
+			if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST)
+				return -EINVAL;
+			if ((dev = __dev_get_by_index(net, nh->nh_oif)) == NULL)
+				return -ENODEV;
+			if (!(dev->flags&IFF_UP))
+				return -ENETDOWN;
+			nh->nh_dev = dev;
+			dev_hold(dev);
+			nh->nh_scope = RT_SCOPE_LINK;
+			return 0;
+		}
+		{
+			struct flowi fl = {
+				.nl_u = {
+					.ip4_u = {
+						.daddr = nh->nh_gw,
+						.scope = cfg->fc_scope + 1,
+					},
+				},
+				.oif = nh->nh_oif,
+			};
+
+			/* It is not necessary, but requires a bit of thinking */
+			if (fl.fl4_scope < RT_SCOPE_LINK)
+				fl.fl4_scope = RT_SCOPE_LINK;
+			if ((err = fib_lookup(net, &fl, &res)) != 0)
+				return err;
+		}
+		err = -EINVAL;
+		if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
+			goto out;
+		nh->nh_scope = res.scope;
+		nh->nh_oif = FIB_RES_OIF(res);
+		if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
+			goto out;
+		dev_hold(nh->nh_dev);
+		err = -ENETDOWN;
+		if (!(nh->nh_dev->flags & IFF_UP))
+			goto out;
+		err = 0;
+out:
+		fib_res_put(&res);
+		return err;
+	} else {
+		struct in_device *in_dev;
+
+		if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
+			return -EINVAL;
+
+		in_dev = inetdev_by_index(net, nh->nh_oif);
+		if (in_dev == NULL)
+			return -ENODEV;
+		if (!(in_dev->dev->flags&IFF_UP)) {
+			in_dev_put(in_dev);
+			return -ENETDOWN;
+		}
+		nh->nh_dev = in_dev->dev;
+		dev_hold(nh->nh_dev);
+		nh->nh_scope = RT_SCOPE_HOST;
+		in_dev_put(in_dev);
+	}
+	return 0;
+}
+
+static inline unsigned int fib_laddr_hashfn(__be32 val)
+{
+	unsigned int mask = (fib_hash_size - 1);
+
+	return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask;
+}
+
+static struct hlist_head *fib_hash_alloc(int bytes)
+{
+	if (bytes <= PAGE_SIZE)
+		return kzalloc(bytes, GFP_KERNEL);
+	else
+		return (struct hlist_head *)
+			__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(bytes));
+}
+
+static void fib_hash_free(struct hlist_head *hash, int bytes)
+{
+	if (!hash)
+		return;
+
+	if (bytes <= PAGE_SIZE)
+		kfree(hash);
+	else
+		free_pages((unsigned long) hash, get_order(bytes));
+}
+
+static void fib_hash_move(struct hlist_head *new_info_hash,
+			  struct hlist_head *new_laddrhash,
+			  unsigned int new_size)
+{
+	struct hlist_head *old_info_hash, *old_laddrhash;
+	unsigned int old_size = fib_hash_size;
+	unsigned int i, bytes;
+
+	spin_lock_bh(&fib_info_lock);
+	old_info_hash = fib_info_hash;
+	old_laddrhash = fib_info_laddrhash;
+	fib_hash_size = new_size;
+
+	for (i = 0; i < old_size; i++) {
+		struct hlist_head *head = &fib_info_hash[i];
+		struct hlist_node *node, *n;
+		struct fib_info *fi;
+
+		hlist_for_each_entry_safe(fi, node, n, head, fib_hash) {
+			struct hlist_head *dest;
+			unsigned int new_hash;
+
+			hlist_del(&fi->fib_hash);
+
+			new_hash = fib_info_hashfn(fi);
+			dest = &new_info_hash[new_hash];
+			hlist_add_head(&fi->fib_hash, dest);
+		}
+	}
+	fib_info_hash = new_info_hash;
+
+	for (i = 0; i < old_size; i++) {
+		struct hlist_head *lhead = &fib_info_laddrhash[i];
+		struct hlist_node *node, *n;
+		struct fib_info *fi;
+
+		hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) {
+			struct hlist_head *ldest;
+			unsigned int new_hash;
+
+			hlist_del(&fi->fib_lhash);
+
+			new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
+			ldest = &new_laddrhash[new_hash];
+			hlist_add_head(&fi->fib_lhash, ldest);
+		}
+	}
+	fib_info_laddrhash = new_laddrhash;
+
+	spin_unlock_bh(&fib_info_lock);
+
+	bytes = old_size * sizeof(struct hlist_head *);
+	fib_hash_free(old_info_hash, bytes);
+	fib_hash_free(old_laddrhash, bytes);
+}
+
+struct fib_info *fib_create_info(struct fib_config *cfg)
+{
+	int err;
+	struct fib_info *fi = NULL;
+	struct fib_info *ofi;
+	int nhs = 1;
+	struct net *net = cfg->fc_nlinfo.nl_net;
+
+	/* Fast check to catch the most weird cases */
+	if (fib_props[cfg->fc_type].scope > cfg->fc_scope)
+		goto err_inval;
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	if (cfg->fc_mp) {
+		nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len);
+		if (nhs == 0)
+			goto err_inval;
+	}
+#endif
+
+	err = -ENOBUFS;
+	if (fib_info_cnt >= fib_hash_size) {
+		unsigned int new_size = fib_hash_size << 1;
+		struct hlist_head *new_info_hash;
+		struct hlist_head *new_laddrhash;
+		unsigned int bytes;
+
+		if (!new_size)
+			new_size = 1;
+		bytes = new_size * sizeof(struct hlist_head *);
+		new_info_hash = fib_hash_alloc(bytes);
+		new_laddrhash = fib_hash_alloc(bytes);
+		if (!new_info_hash || !new_laddrhash) {
+			fib_hash_free(new_info_hash, bytes);
+			fib_hash_free(new_laddrhash, bytes);
+		} else
+			fib_hash_move(new_info_hash, new_laddrhash, new_size);
+
+		if (!fib_hash_size)
+			goto failure;
+	}
+
+	fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
+	if (fi == NULL)
+		goto failure;
+	fib_info_cnt++;
+
+	fi->fib_net = hold_net(net);
+	fi->fib_protocol = cfg->fc_protocol;
+	fi->fib_flags = cfg->fc_flags;
+	fi->fib_priority = cfg->fc_priority;
+	fi->fib_prefsrc = cfg->fc_prefsrc;
+
+	fi->fib_nhs = nhs;
+	change_nexthops(fi) {
+		nh->nh_parent = fi;
+	} endfor_nexthops(fi)
+
+	if (cfg->fc_mx) {
+		struct nlattr *nla;
+		int remaining;
+
+		nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
+			int type = nla_type(nla);
+
+			if (type) {
+				if (type > RTAX_MAX)
+					goto err_inval;
+				fi->fib_metrics[type - 1] = nla_get_u32(nla);
+			}
+		}
+	}
+
+	if (cfg->fc_mp) {
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+		err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg);
+		if (err != 0)
+			goto failure;
+		if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif)
+			goto err_inval;
+		if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw)
+			goto err_inval;
+#ifdef CONFIG_NET_CLS_ROUTE
+		if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow)
+			goto err_inval;
+#endif
+#else
+		goto err_inval;
+#endif
+	} else {
+		struct fib_nh *nh = fi->fib_nh;
+
+		nh->nh_oif = cfg->fc_oif;
+		nh->nh_gw = cfg->fc_gw;
+		nh->nh_flags = cfg->fc_flags;
+#ifdef CONFIG_NET_CLS_ROUTE
+		nh->nh_tclassid = cfg->fc_flow;
+#endif
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+		nh->nh_weight = 1;
+#endif
+	}
+
+	if (fib_props[cfg->fc_type].error) {
+		if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp)
+			goto err_inval;
+		goto link_it;
+	}
+
+	if (cfg->fc_scope > RT_SCOPE_HOST)
+		goto err_inval;
+
+	if (cfg->fc_scope == RT_SCOPE_HOST) {
+		struct fib_nh *nh = fi->fib_nh;
+
+		/* Local address is added. */
+		if (nhs != 1 || nh->nh_gw)
+			goto err_inval;
+		nh->nh_scope = RT_SCOPE_NOWHERE;
+		nh->nh_dev = dev_get_by_index(net, fi->fib_nh->nh_oif);
+		err = -ENODEV;
+		if (nh->nh_dev == NULL)
+			goto failure;
+	} else {
+		change_nexthops(fi) {
+			if ((err = fib_check_nh(cfg, fi, nh)) != 0)
+				goto failure;
+		} endfor_nexthops(fi)
+	}
+
+	if (fi->fib_prefsrc) {
+		if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
+		    fi->fib_prefsrc != cfg->fc_dst)
+			if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL)
+				goto err_inval;
+	}
+
+link_it:
+	if ((ofi = fib_find_info(fi)) != NULL) {
+		fi->fib_dead = 1;
+		free_fib_info(fi);
+		ofi->fib_treeref++;
+		return ofi;
+	}
+
+	fi->fib_treeref++;
+	atomic_inc(&fi->fib_clntref);
+	spin_lock_bh(&fib_info_lock);
+	hlist_add_head(&fi->fib_hash,
+		       &fib_info_hash[fib_info_hashfn(fi)]);
+	if (fi->fib_prefsrc) {
+		struct hlist_head *head;
+
+		head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
+		hlist_add_head(&fi->fib_lhash, head);
+	}
+	change_nexthops(fi) {
+		struct hlist_head *head;
+		unsigned int hash;
+
+		if (!nh->nh_dev)
+			continue;
+		hash = fib_devindex_hashfn(nh->nh_dev->ifindex);
+		head = &fib_info_devhash[hash];
+		hlist_add_head(&nh->nh_hash, head);
+	} endfor_nexthops(fi)
+	spin_unlock_bh(&fib_info_lock);
+	return fi;
+
+err_inval:
+	err = -EINVAL;
+
+failure:
+	if (fi) {
+		fi->fib_dead = 1;
+		free_fib_info(fi);
+	}
+
+	return ERR_PTR(err);
+}
+
+/* Note! fib_semantic_match intentionally uses  RCU list functions. */
+int fib_semantic_match(struct list_head *head, const struct flowi *flp,
+		       struct fib_result *res, __be32 zone, __be32 mask,
+			int prefixlen)
+{
+	struct fib_alias *fa;
+	int nh_sel = 0;
+
+	list_for_each_entry_rcu(fa, head, fa_list) {
+		int err;
+
+		if (fa->fa_tos &&
+		    fa->fa_tos != flp->fl4_tos)
+			continue;
+
+		if (fa->fa_scope < flp->fl4_scope)
+			continue;
+
+		fa->fa_state |= FA_S_ACCESSED;
+
+		err = fib_props[fa->fa_type].error;
+		if (err == 0) {
+			struct fib_info *fi = fa->fa_info;
+
+			if (fi->fib_flags & RTNH_F_DEAD)
+				continue;
+
+			switch (fa->fa_type) {
+			case RTN_UNICAST:
+			case RTN_LOCAL:
+			case RTN_BROADCAST:
+			case RTN_ANYCAST:
+			case RTN_MULTICAST:
+				for_nexthops(fi) {
+					if (nh->nh_flags&RTNH_F_DEAD)
+						continue;
+					if (!flp->oif || flp->oif == nh->nh_oif)
+						break;
+				}
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+				if (nhsel < fi->fib_nhs) {
+					nh_sel = nhsel;
+					goto out_fill_res;
+				}
+#else
+				if (nhsel < 1) {
+					goto out_fill_res;
+				}
+#endif
+				endfor_nexthops(fi);
+				continue;
+
+			default:
+				printk(KERN_WARNING "fib_semantic_match bad type %#x\n",
+					fa->fa_type);
+				return -EINVAL;
+			}
+		}
+		return err;
+	}
+	return 1;
+
+out_fill_res:
+	res->prefixlen = prefixlen;
+	res->nh_sel = nh_sel;
+	res->type = fa->fa_type;
+	res->scope = fa->fa_scope;
+	res->fi = fa->fa_info;
+	atomic_inc(&res->fi->fib_clntref);
+	return 0;
+}
+
+/* Find appropriate source address to this destination */
+
+__be32 __fib_res_prefsrc(struct fib_result *res)
+{
+	return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope);
+}
+
+int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
+		  u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos,
+		  struct fib_info *fi, unsigned int flags)
+{
+	struct nlmsghdr *nlh;
+	struct rtmsg *rtm;
+
+	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
+	if (nlh == NULL)
+		return -EMSGSIZE;
+
+	rtm = nlmsg_data(nlh);
+	rtm->rtm_family = AF_INET;
+	rtm->rtm_dst_len = dst_len;
+	rtm->rtm_src_len = 0;
+	rtm->rtm_tos = tos;
+	if (tb_id < 256)
+		rtm->rtm_table = tb_id;
+	else
+		rtm->rtm_table = RT_TABLE_COMPAT;
+	NLA_PUT_U32(skb, RTA_TABLE, tb_id);
+	rtm->rtm_type = type;
+	rtm->rtm_flags = fi->fib_flags;
+	rtm->rtm_scope = scope;
+	rtm->rtm_protocol = fi->fib_protocol;
+
+	if (rtm->rtm_dst_len)
+		NLA_PUT_BE32(skb, RTA_DST, dst);
+
+	if (fi->fib_priority)
+		NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority);
+
+	if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
+		goto nla_put_failure;
+
+	if (fi->fib_prefsrc)
+		NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc);
+
+	if (fi->fib_nhs == 1) {
+		if (fi->fib_nh->nh_gw)
+			NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw);
+
+		if (fi->fib_nh->nh_oif)
+			NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif);
+#ifdef CONFIG_NET_CLS_ROUTE
+		if (fi->fib_nh[0].nh_tclassid)
+			NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid);
+#endif
+	}
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	if (fi->fib_nhs > 1) {
+		struct rtnexthop *rtnh;
+		struct nlattr *mp;
+
+		mp = nla_nest_start(skb, RTA_MULTIPATH);
+		if (mp == NULL)
+			goto nla_put_failure;
+
+		for_nexthops(fi) {
+			rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
+			if (rtnh == NULL)
+				goto nla_put_failure;
+
+			rtnh->rtnh_flags = nh->nh_flags & 0xFF;
+			rtnh->rtnh_hops = nh->nh_weight - 1;
+			rtnh->rtnh_ifindex = nh->nh_oif;
+
+			if (nh->nh_gw)
+				NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw);
+#ifdef CONFIG_NET_CLS_ROUTE
+			if (nh->nh_tclassid)
+				NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid);
+#endif
+			/* length of rtnetlink header + attributes */
+			rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
+		} endfor_nexthops(fi);
+
+		nla_nest_end(skb, mp);
+	}
+#endif
+	return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+/*
+   Update FIB if:
+   - local address disappeared -> we must delete all the entries
+     referring to it.
+   - device went down -> we must shutdown all nexthops going via it.
+ */
+int fib_sync_down_addr(struct net *net, __be32 local)
+{
+	int ret = 0;
+	unsigned int hash = fib_laddr_hashfn(local);
+	struct hlist_head *head = &fib_info_laddrhash[hash];
+	struct hlist_node *node;
+	struct fib_info *fi;
+
+	if (fib_info_laddrhash == NULL || local == 0)
+		return 0;
+
+	hlist_for_each_entry(fi, node, head, fib_lhash) {
+		if (fi->fib_net != net)
+			continue;
+		if (fi->fib_prefsrc == local) {
+			fi->fib_flags |= RTNH_F_DEAD;
+			ret++;
+		}
+	}
+	return ret;
+}
+
+int fib_sync_down_dev(struct net_device *dev, int force)
+{
+	int ret = 0;
+	int scope = RT_SCOPE_NOWHERE;
+	struct fib_info *prev_fi = NULL;
+	unsigned int hash = fib_devindex_hashfn(dev->ifindex);
+	struct hlist_head *head = &fib_info_devhash[hash];
+	struct hlist_node *node;
+	struct fib_nh *nh;
+
+	if (force)
+		scope = -1;
+
+	hlist_for_each_entry(nh, node, head, nh_hash) {
+		struct fib_info *fi = nh->nh_parent;
+		int dead;
+
+		BUG_ON(!fi->fib_nhs);
+		if (nh->nh_dev != dev || fi == prev_fi)
+			continue;
+		prev_fi = fi;
+		dead = 0;
+		change_nexthops(fi) {
+			if (nh->nh_flags&RTNH_F_DEAD)
+				dead++;
+			else if (nh->nh_dev == dev &&
+					nh->nh_scope != scope) {
+				nh->nh_flags |= RTNH_F_DEAD;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+				spin_lock_bh(&fib_multipath_lock);
+				fi->fib_power -= nh->nh_power;
+				nh->nh_power = 0;
+				spin_unlock_bh(&fib_multipath_lock);
+#endif
+				dead++;
+			}
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+			if (force > 1 && nh->nh_dev == dev) {
+				dead = fi->fib_nhs;
+				break;
+			}
+#endif
+		} endfor_nexthops(fi)
+		if (dead == fi->fib_nhs) {
+			fi->fib_flags |= RTNH_F_DEAD;
+			ret++;
+		}
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+
+/*
+   Dead device goes up. We wake up dead nexthops.
+   It takes sense only on multipath routes.
+ */
+
+int fib_sync_up(struct net_device *dev)
+{
+	struct fib_info *prev_fi;
+	unsigned int hash;
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct fib_nh *nh;
+	int ret;
+
+	if (!(dev->flags&IFF_UP))
+		return 0;
+
+	prev_fi = NULL;
+	hash = fib_devindex_hashfn(dev->ifindex);
+	head = &fib_info_devhash[hash];
+	ret = 0;
+
+	hlist_for_each_entry(nh, node, head, nh_hash) {
+		struct fib_info *fi = nh->nh_parent;
+		int alive;
+
+		BUG_ON(!fi->fib_nhs);
+		if (nh->nh_dev != dev || fi == prev_fi)
+			continue;
+
+		prev_fi = fi;
+		alive = 0;
+		change_nexthops(fi) {
+			if (!(nh->nh_flags&RTNH_F_DEAD)) {
+				alive++;
+				continue;
+			}
+			if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
+				continue;
+			if (nh->nh_dev != dev || !__in_dev_get_rtnl(dev))
+				continue;
+			alive++;
+			spin_lock_bh(&fib_multipath_lock);
+			nh->nh_power = 0;
+			nh->nh_flags &= ~RTNH_F_DEAD;
+			spin_unlock_bh(&fib_multipath_lock);
+		} endfor_nexthops(fi)
+
+		if (alive > 0) {
+			fi->fib_flags &= ~RTNH_F_DEAD;
+			ret++;
+		}
+	}
+
+	return ret;
+}
+
+/*
+   The algorithm is suboptimal, but it provides really
+   fair weighted route distribution.
+ */
+
+void fib_select_multipath(const struct flowi *flp, struct fib_result *res)
+{
+	struct fib_info *fi = res->fi;
+	int w;
+
+	spin_lock_bh(&fib_multipath_lock);
+	if (fi->fib_power <= 0) {
+		int power = 0;
+		change_nexthops(fi) {
+			if (!(nh->nh_flags&RTNH_F_DEAD)) {
+				power += nh->nh_weight;
+				nh->nh_power = nh->nh_weight;
+			}
+		} endfor_nexthops(fi);
+		fi->fib_power = power;
+		if (power <= 0) {
+			spin_unlock_bh(&fib_multipath_lock);
+			/* Race condition: route has just become dead. */
+			res->nh_sel = 0;
+			return;
+		}
+	}
+
+
+	/* w should be random number [0..fi->fib_power-1],
+	   it is pretty bad approximation.
+	 */
+
+	w = jiffies % fi->fib_power;
+
+	change_nexthops(fi) {
+		if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
+			if ((w -= nh->nh_power) <= 0) {
+				nh->nh_power--;
+				fi->fib_power--;
+				res->nh_sel = nhsel;
+				spin_unlock_bh(&fib_multipath_lock);
+				return;
+			}
+		}
+	} endfor_nexthops(fi);
+
+	/* Race condition: route has just become dead. */
+	res->nh_sel = 0;
+	spin_unlock_bh(&fib_multipath_lock);
+}
+#endif
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
new file mode 100644
index 0000000..5cb7278
--- /dev/null
+++ b/net/ipv4/fib_trie.c
@@ -0,0 +1,2663 @@
+/*
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation; either version
+ *   2 of the License, or (at your option) any later version.
+ *
+ *   Robert Olsson <robert.olsson@its.uu.se> Uppsala Universitet
+ *     & Swedish University of Agricultural Sciences.
+ *
+ *   Jens Laas <jens.laas@data.slu.se> Swedish University of
+ *     Agricultural Sciences.
+ *
+ *   Hans Liss <hans.liss@its.uu.se>  Uppsala Universitet
+ *
+ * This work is based on the LPC-trie which is originally descibed in:
+ *
+ * An experimental study of compression methods for dynamic tries
+ * Stefan Nilsson and Matti Tikkanen. Algorithmica, 33(1):19-33, 2002.
+ * http://www.nada.kth.se/~snilsson/public/papers/dyntrie2/
+ *
+ *
+ * IP-address lookup using LC-tries. Stefan Nilsson and Gunnar Karlsson
+ * IEEE Journal on Selected Areas in Communications, 17(6):1083-1092, June 1999
+ *
+ *
+ * Code from fib_hash has been reused which includes the following header:
+ *
+ *
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		IPv4 FIB: lookup engine and maintenance routines.
+ *
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * Substantial contributions to this work comes from:
+ *
+ *		David S. Miller, <davem@davemloft.net>
+ *		Stephen Hemminger <shemminger@osdl.org>
+ *		Paul E. McKenney <paulmck@us.ibm.com>
+ *		Patrick McHardy <kaber@trash.net>
+ */
+
+#define VERSION "0.408"
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/rcupdate.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+#include "fib_lookup.h"
+
+#define MAX_STAT_DEPTH 32
+
+#define KEYLENGTH (8*sizeof(t_key))
+
+typedef unsigned int t_key;
+
+#define T_TNODE 0
+#define T_LEAF  1
+#define NODE_TYPE_MASK	0x1UL
+#define NODE_TYPE(node) ((node)->parent & NODE_TYPE_MASK)
+
+#define IS_TNODE(n) (!(n->parent & T_LEAF))
+#define IS_LEAF(n) (n->parent & T_LEAF)
+
+struct node {
+	unsigned long parent;
+	t_key key;
+};
+
+struct leaf {
+	unsigned long parent;
+	t_key key;
+	struct hlist_head list;
+	struct rcu_head rcu;
+};
+
+struct leaf_info {
+	struct hlist_node hlist;
+	struct rcu_head rcu;
+	int plen;
+	struct list_head falh;
+};
+
+struct tnode {
+	unsigned long parent;
+	t_key key;
+	unsigned char pos;		/* 2log(KEYLENGTH) bits needed */
+	unsigned char bits;		/* 2log(KEYLENGTH) bits needed */
+	unsigned int full_children;	/* KEYLENGTH bits needed */
+	unsigned int empty_children;	/* KEYLENGTH bits needed */
+	union {
+		struct rcu_head rcu;
+		struct work_struct work;
+	};
+	struct node *child[0];
+};
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+struct trie_use_stats {
+	unsigned int gets;
+	unsigned int backtrack;
+	unsigned int semantic_match_passed;
+	unsigned int semantic_match_miss;
+	unsigned int null_node_hit;
+	unsigned int resize_node_skipped;
+};
+#endif
+
+struct trie_stat {
+	unsigned int totdepth;
+	unsigned int maxdepth;
+	unsigned int tnodes;
+	unsigned int leaves;
+	unsigned int nullpointers;
+	unsigned int prefixes;
+	unsigned int nodesizes[MAX_STAT_DEPTH];
+};
+
+struct trie {
+	struct node *trie;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+	struct trie_use_stats stats;
+#endif
+};
+
+static void put_child(struct trie *t, struct tnode *tn, int i, struct node *n);
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n,
+				  int wasfull);
+static struct node *resize(struct trie *t, struct tnode *tn);
+static struct tnode *inflate(struct trie *t, struct tnode *tn);
+static struct tnode *halve(struct trie *t, struct tnode *tn);
+
+static struct kmem_cache *fn_alias_kmem __read_mostly;
+static struct kmem_cache *trie_leaf_kmem __read_mostly;
+
+static inline struct tnode *node_parent(struct node *node)
+{
+	return (struct tnode *)(node->parent & ~NODE_TYPE_MASK);
+}
+
+static inline struct tnode *node_parent_rcu(struct node *node)
+{
+	struct tnode *ret = node_parent(node);
+
+	return rcu_dereference(ret);
+}
+
+/* Same as rcu_assign_pointer
+ * but that macro() assumes that value is a pointer.
+ */
+static inline void node_set_parent(struct node *node, struct tnode *ptr)
+{
+	smp_wmb();
+	node->parent = (unsigned long)ptr | NODE_TYPE(node);
+}
+
+static inline struct node *tnode_get_child(struct tnode *tn, unsigned int i)
+{
+	BUG_ON(i >= 1U << tn->bits);
+
+	return tn->child[i];
+}
+
+static inline struct node *tnode_get_child_rcu(struct tnode *tn, unsigned int i)
+{
+	struct node *ret = tnode_get_child(tn, i);
+
+	return rcu_dereference(ret);
+}
+
+static inline int tnode_child_length(const struct tnode *tn)
+{
+	return 1 << tn->bits;
+}
+
+static inline t_key mask_pfx(t_key k, unsigned short l)
+{
+	return (l == 0) ? 0 : k >> (KEYLENGTH-l) << (KEYLENGTH-l);
+}
+
+static inline t_key tkey_extract_bits(t_key a, int offset, int bits)
+{
+	if (offset < KEYLENGTH)
+		return ((t_key)(a << offset)) >> (KEYLENGTH - bits);
+	else
+		return 0;
+}
+
+static inline int tkey_equals(t_key a, t_key b)
+{
+	return a == b;
+}
+
+static inline int tkey_sub_equals(t_key a, int offset, int bits, t_key b)
+{
+	if (bits == 0 || offset >= KEYLENGTH)
+		return 1;
+	bits = bits > KEYLENGTH ? KEYLENGTH : bits;
+	return ((a ^ b) << offset) >> (KEYLENGTH - bits) == 0;
+}
+
+static inline int tkey_mismatch(t_key a, int offset, t_key b)
+{
+	t_key diff = a ^ b;
+	int i = offset;
+
+	if (!diff)
+		return 0;
+	while ((diff << i) >> (KEYLENGTH-1) == 0)
+		i++;
+	return i;
+}
+
+/*
+  To understand this stuff, an understanding of keys and all their bits is
+  necessary. Every node in the trie has a key associated with it, but not
+  all of the bits in that key are significant.
+
+  Consider a node 'n' and its parent 'tp'.
+
+  If n is a leaf, every bit in its key is significant. Its presence is
+  necessitated by path compression, since during a tree traversal (when
+  searching for a leaf - unless we are doing an insertion) we will completely
+  ignore all skipped bits we encounter. Thus we need to verify, at the end of
+  a potentially successful search, that we have indeed been walking the
+  correct key path.
+
+  Note that we can never "miss" the correct key in the tree if present by
+  following the wrong path. Path compression ensures that segments of the key
+  that are the same for all keys with a given prefix are skipped, but the
+  skipped part *is* identical for each node in the subtrie below the skipped
+  bit! trie_insert() in this implementation takes care of that - note the
+  call to tkey_sub_equals() in trie_insert().
+
+  if n is an internal node - a 'tnode' here, the various parts of its key
+  have many different meanings.
+
+  Example:
+  _________________________________________________________________
+  | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
+  -----------------------------------------------------------------
+    0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
+
+  _________________________________________________________________
+  | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
+  -----------------------------------------------------------------
+   16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
+
+  tp->pos = 7
+  tp->bits = 3
+  n->pos = 15
+  n->bits = 4
+
+  First, let's just ignore the bits that come before the parent tp, that is
+  the bits from 0 to (tp->pos-1). They are *known* but at this point we do
+  not use them for anything.
+
+  The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
+  index into the parent's child array. That is, they will be used to find
+  'n' among tp's children.
+
+  The bits from (tp->pos + tp->bits) to (n->pos - 1) - "S" - are skipped bits
+  for the node n.
+
+  All the bits we have seen so far are significant to the node n. The rest
+  of the bits are really not needed or indeed known in n->key.
+
+  The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
+  n's child array, and will of course be different for each child.
+
+
+  The rest of the bits, from (n->pos + n->bits) onward, are completely unknown
+  at this point.
+
+*/
+
+static inline void check_tnode(const struct tnode *tn)
+{
+	WARN_ON(tn && tn->pos+tn->bits > 32);
+}
+
+static const int halve_threshold = 25;
+static const int inflate_threshold = 50;
+static const int halve_threshold_root = 8;
+static const int inflate_threshold_root = 15;
+
+
+static void __alias_free_mem(struct rcu_head *head)
+{
+	struct fib_alias *fa = container_of(head, struct fib_alias, rcu);
+	kmem_cache_free(fn_alias_kmem, fa);
+}
+
+static inline void alias_free_mem_rcu(struct fib_alias *fa)
+{
+	call_rcu(&fa->rcu, __alias_free_mem);
+}
+
+static void __leaf_free_rcu(struct rcu_head *head)
+{
+	struct leaf *l = container_of(head, struct leaf, rcu);
+	kmem_cache_free(trie_leaf_kmem, l);
+}
+
+static inline void free_leaf(struct leaf *l)
+{
+	call_rcu_bh(&l->rcu, __leaf_free_rcu);
+}
+
+static void __leaf_info_free_rcu(struct rcu_head *head)
+{
+	kfree(container_of(head, struct leaf_info, rcu));
+}
+
+static inline void free_leaf_info(struct leaf_info *leaf)
+{
+	call_rcu(&leaf->rcu, __leaf_info_free_rcu);
+}
+
+static struct tnode *tnode_alloc(size_t size)
+{
+	if (size <= PAGE_SIZE)
+		return kzalloc(size, GFP_KERNEL);
+	else
+		return __vmalloc(size, GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL);
+}
+
+static void __tnode_vfree(struct work_struct *arg)
+{
+	struct tnode *tn = container_of(arg, struct tnode, work);
+	vfree(tn);
+}
+
+static void __tnode_free_rcu(struct rcu_head *head)
+{
+	struct tnode *tn = container_of(head, struct tnode, rcu);
+	size_t size = sizeof(struct tnode) +
+		      (sizeof(struct node *) << tn->bits);
+
+	if (size <= PAGE_SIZE)
+		kfree(tn);
+	else {
+		INIT_WORK(&tn->work, __tnode_vfree);
+		schedule_work(&tn->work);
+	}
+}
+
+static inline void tnode_free(struct tnode *tn)
+{
+	if (IS_LEAF(tn))
+		free_leaf((struct leaf *) tn);
+	else
+		call_rcu(&tn->rcu, __tnode_free_rcu);
+}
+
+static struct leaf *leaf_new(void)
+{
+	struct leaf *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
+	if (l) {
+		l->parent = T_LEAF;
+		INIT_HLIST_HEAD(&l->list);
+	}
+	return l;
+}
+
+static struct leaf_info *leaf_info_new(int plen)
+{
+	struct leaf_info *li = kmalloc(sizeof(struct leaf_info),  GFP_KERNEL);
+	if (li) {
+		li->plen = plen;
+		INIT_LIST_HEAD(&li->falh);
+	}
+	return li;
+}
+
+static struct tnode *tnode_new(t_key key, int pos, int bits)
+{
+	size_t sz = sizeof(struct tnode) + (sizeof(struct node *) << bits);
+	struct tnode *tn = tnode_alloc(sz);
+
+	if (tn) {
+		tn->parent = T_TNODE;
+		tn->pos = pos;
+		tn->bits = bits;
+		tn->key = key;
+		tn->full_children = 0;
+		tn->empty_children = 1<<bits;
+	}
+
+	pr_debug("AT %p s=%u %lu\n", tn, (unsigned int) sizeof(struct tnode),
+		 (unsigned long) (sizeof(struct node) << bits));
+	return tn;
+}
+
+/*
+ * Check whether a tnode 'n' is "full", i.e. it is an internal node
+ * and no bits are skipped. See discussion in dyntree paper p. 6
+ */
+
+static inline int tnode_full(const struct tnode *tn, const struct node *n)
+{
+	if (n == NULL || IS_LEAF(n))
+		return 0;
+
+	return ((struct tnode *) n)->pos == tn->pos + tn->bits;
+}
+
+static inline void put_child(struct trie *t, struct tnode *tn, int i,
+			     struct node *n)
+{
+	tnode_put_child_reorg(tn, i, n, -1);
+}
+
+ /*
+  * Add a child at position i overwriting the old value.
+  * Update the value of full_children and empty_children.
+  */
+
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n,
+				  int wasfull)
+{
+	struct node *chi = tn->child[i];
+	int isfull;
+
+	BUG_ON(i >= 1<<tn->bits);
+
+	/* update emptyChildren */
+	if (n == NULL && chi != NULL)
+		tn->empty_children++;
+	else if (n != NULL && chi == NULL)
+		tn->empty_children--;
+
+	/* update fullChildren */
+	if (wasfull == -1)
+		wasfull = tnode_full(tn, chi);
+
+	isfull = tnode_full(tn, n);
+	if (wasfull && !isfull)
+		tn->full_children--;
+	else if (!wasfull && isfull)
+		tn->full_children++;
+
+	if (n)
+		node_set_parent(n, tn);
+
+	rcu_assign_pointer(tn->child[i], n);
+}
+
+static struct node *resize(struct trie *t, struct tnode *tn)
+{
+	int i;
+	int err = 0;
+	struct tnode *old_tn;
+	int inflate_threshold_use;
+	int halve_threshold_use;
+	int max_resize;
+
+	if (!tn)
+		return NULL;
+
+	pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+		 tn, inflate_threshold, halve_threshold);
+
+	/* No children */
+	if (tn->empty_children == tnode_child_length(tn)) {
+		tnode_free(tn);
+		return NULL;
+	}
+	/* One child */
+	if (tn->empty_children == tnode_child_length(tn) - 1)
+		for (i = 0; i < tnode_child_length(tn); i++) {
+			struct node *n;
+
+			n = tn->child[i];
+			if (!n)
+				continue;
+
+			/* compress one level */
+			node_set_parent(n, NULL);
+			tnode_free(tn);
+			return n;
+		}
+	/*
+	 * Double as long as the resulting node has a number of
+	 * nonempty nodes that are above the threshold.
+	 */
+
+	/*
+	 * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
+	 * the Helsinki University of Technology and Matti Tikkanen of Nokia
+	 * Telecommunications, page 6:
+	 * "A node is doubled if the ratio of non-empty children to all
+	 * children in the *doubled* node is at least 'high'."
+	 *
+	 * 'high' in this instance is the variable 'inflate_threshold'. It
+	 * is expressed as a percentage, so we multiply it with
+	 * tnode_child_length() and instead of multiplying by 2 (since the
+	 * child array will be doubled by inflate()) and multiplying
+	 * the left-hand side by 100 (to handle the percentage thing) we
+	 * multiply the left-hand side by 50.
+	 *
+	 * The left-hand side may look a bit weird: tnode_child_length(tn)
+	 * - tn->empty_children is of course the number of non-null children
+	 * in the current node. tn->full_children is the number of "full"
+	 * children, that is non-null tnodes with a skip value of 0.
+	 * All of those will be doubled in the resulting inflated tnode, so
+	 * we just count them one extra time here.
+	 *
+	 * A clearer way to write this would be:
+	 *
+	 * to_be_doubled = tn->full_children;
+	 * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
+	 *     tn->full_children;
+	 *
+	 * new_child_length = tnode_child_length(tn) * 2;
+	 *
+	 * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
+	 *      new_child_length;
+	 * if (new_fill_factor >= inflate_threshold)
+	 *
+	 * ...and so on, tho it would mess up the while () loop.
+	 *
+	 * anyway,
+	 * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
+	 *      inflate_threshold
+	 *
+	 * avoid a division:
+	 * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
+	 *      inflate_threshold * new_child_length
+	 *
+	 * expand not_to_be_doubled and to_be_doubled, and shorten:
+	 * 100 * (tnode_child_length(tn) - tn->empty_children +
+	 *    tn->full_children) >= inflate_threshold * new_child_length
+	 *
+	 * expand new_child_length:
+	 * 100 * (tnode_child_length(tn) - tn->empty_children +
+	 *    tn->full_children) >=
+	 *      inflate_threshold * tnode_child_length(tn) * 2
+	 *
+	 * shorten again:
+	 * 50 * (tn->full_children + tnode_child_length(tn) -
+	 *    tn->empty_children) >= inflate_threshold *
+	 *    tnode_child_length(tn)
+	 *
+	 */
+
+	check_tnode(tn);
+
+	/* Keep root node larger  */
+
+	if (!tn->parent)
+		inflate_threshold_use = inflate_threshold_root;
+	else
+		inflate_threshold_use = inflate_threshold;
+
+	err = 0;
+	max_resize = 10;
+	while ((tn->full_children > 0 &&  max_resize-- &&
+		50 * (tn->full_children + tnode_child_length(tn)
+		      - tn->empty_children)
+		>= inflate_threshold_use * tnode_child_length(tn))) {
+
+		old_tn = tn;
+		tn = inflate(t, tn);
+
+		if (IS_ERR(tn)) {
+			tn = old_tn;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.resize_node_skipped++;
+#endif
+			break;
+		}
+	}
+
+	if (max_resize < 0) {
+		if (!tn->parent)
+			pr_warning("Fix inflate_threshold_root."
+				   " Now=%d size=%d bits\n",
+				   inflate_threshold_root, tn->bits);
+		else
+			pr_warning("Fix inflate_threshold."
+				   " Now=%d size=%d bits\n",
+				   inflate_threshold, tn->bits);
+	}
+
+	check_tnode(tn);
+
+	/*
+	 * Halve as long as the number of empty children in this
+	 * node is above threshold.
+	 */
+
+
+	/* Keep root node larger  */
+
+	if (!tn->parent)
+		halve_threshold_use = halve_threshold_root;
+	else
+		halve_threshold_use = halve_threshold;
+
+	err = 0;
+	max_resize = 10;
+	while (tn->bits > 1 &&  max_resize-- &&
+	       100 * (tnode_child_length(tn) - tn->empty_children) <
+	       halve_threshold_use * tnode_child_length(tn)) {
+
+		old_tn = tn;
+		tn = halve(t, tn);
+		if (IS_ERR(tn)) {
+			tn = old_tn;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.resize_node_skipped++;
+#endif
+			break;
+		}
+	}
+
+	if (max_resize < 0) {
+		if (!tn->parent)
+			pr_warning("Fix halve_threshold_root."
+				   " Now=%d size=%d bits\n",
+				   halve_threshold_root, tn->bits);
+		else
+			pr_warning("Fix halve_threshold."
+				   " Now=%d size=%d bits\n",
+				   halve_threshold, tn->bits);
+	}
+
+	/* Only one child remains */
+	if (tn->empty_children == tnode_child_length(tn) - 1)
+		for (i = 0; i < tnode_child_length(tn); i++) {
+			struct node *n;
+
+			n = tn->child[i];
+			if (!n)
+				continue;
+
+			/* compress one level */
+
+			node_set_parent(n, NULL);
+			tnode_free(tn);
+			return n;
+		}
+
+	return (struct node *) tn;
+}
+
+static struct tnode *inflate(struct trie *t, struct tnode *tn)
+{
+	struct tnode *oldtnode = tn;
+	int olen = tnode_child_length(tn);
+	int i;
+
+	pr_debug("In inflate\n");
+
+	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);
+
+	if (!tn)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Preallocate and store tnodes before the actual work so we
+	 * don't get into an inconsistent state if memory allocation
+	 * fails. In case of failure we return the oldnode and  inflate
+	 * of tnode is ignored.
+	 */
+
+	for (i = 0; i < olen; i++) {
+		struct tnode *inode;
+
+		inode = (struct tnode *) tnode_get_child(oldtnode, i);
+		if (inode &&
+		    IS_TNODE(inode) &&
+		    inode->pos == oldtnode->pos + oldtnode->bits &&
+		    inode->bits > 1) {
+			struct tnode *left, *right;
+			t_key m = ~0U << (KEYLENGTH - 1) >> inode->pos;
+
+			left = tnode_new(inode->key&(~m), inode->pos + 1,
+					 inode->bits - 1);
+			if (!left)
+				goto nomem;
+
+			right = tnode_new(inode->key|m, inode->pos + 1,
+					  inode->bits - 1);
+
+			if (!right) {
+				tnode_free(left);
+				goto nomem;
+			}
+
+			put_child(t, tn, 2*i, (struct node *) left);
+			put_child(t, tn, 2*i+1, (struct node *) right);
+		}
+	}
+
+	for (i = 0; i < olen; i++) {
+		struct tnode *inode;
+		struct node *node = tnode_get_child(oldtnode, i);
+		struct tnode *left, *right;
+		int size, j;
+
+		/* An empty child */
+		if (node == NULL)
+			continue;
+
+		/* A leaf or an internal node with skipped bits */
+
+		if (IS_LEAF(node) || ((struct tnode *) node)->pos >
+		   tn->pos + tn->bits - 1) {
+			if (tkey_extract_bits(node->key,
+					      oldtnode->pos + oldtnode->bits,
+					      1) == 0)
+				put_child(t, tn, 2*i, node);
+			else
+				put_child(t, tn, 2*i+1, node);
+			continue;
+		}
+
+		/* An internal node with two children */
+		inode = (struct tnode *) node;
+
+		if (inode->bits == 1) {
+			put_child(t, tn, 2*i, inode->child[0]);
+			put_child(t, tn, 2*i+1, inode->child[1]);
+
+			tnode_free(inode);
+			continue;
+		}
+
+		/* An internal node with more than two children */
+
+		/* We will replace this node 'inode' with two new
+		 * ones, 'left' and 'right', each with half of the
+		 * original children. The two new nodes will have
+		 * a position one bit further down the key and this
+		 * means that the "significant" part of their keys
+		 * (see the discussion near the top of this file)
+		 * will differ by one bit, which will be "0" in
+		 * left's key and "1" in right's key. Since we are
+		 * moving the key position by one step, the bit that
+		 * we are moving away from - the bit at position
+		 * (inode->pos) - is the one that will differ between
+		 * left and right. So... we synthesize that bit in the
+		 * two  new keys.
+		 * The mask 'm' below will be a single "one" bit at
+		 * the position (inode->pos)
+		 */
+
+		/* Use the old key, but set the new significant
+		 *   bit to zero.
+		 */
+
+		left = (struct tnode *) tnode_get_child(tn, 2*i);
+		put_child(t, tn, 2*i, NULL);
+
+		BUG_ON(!left);
+
+		right = (struct tnode *) tnode_get_child(tn, 2*i+1);
+		put_child(t, tn, 2*i+1, NULL);
+
+		BUG_ON(!right);
+
+		size = tnode_child_length(left);
+		for (j = 0; j < size; j++) {
+			put_child(t, left, j, inode->child[j]);
+			put_child(t, right, j, inode->child[j + size]);
+		}
+		put_child(t, tn, 2*i, resize(t, left));
+		put_child(t, tn, 2*i+1, resize(t, right));
+
+		tnode_free(inode);
+	}
+	tnode_free(oldtnode);
+	return tn;
+nomem:
+	{
+		int size = tnode_child_length(tn);
+		int j;
+
+		for (j = 0; j < size; j++)
+			if (tn->child[j])
+				tnode_free((struct tnode *)tn->child[j]);
+
+		tnode_free(tn);
+
+		return ERR_PTR(-ENOMEM);
+	}
+}
+
+static struct tnode *halve(struct trie *t, struct tnode *tn)
+{
+	struct tnode *oldtnode = tn;
+	struct node *left, *right;
+	int i;
+	int olen = tnode_child_length(tn);
+
+	pr_debug("In halve\n");
+
+	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
+
+	if (!tn)
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Preallocate and store tnodes before the actual work so we
+	 * don't get into an inconsistent state if memory allocation
+	 * fails. In case of failure we return the oldnode and halve
+	 * of tnode is ignored.
+	 */
+
+	for (i = 0; i < olen; i += 2) {
+		left = tnode_get_child(oldtnode, i);
+		right = tnode_get_child(oldtnode, i+1);
+
+		/* Two nonempty children */
+		if (left && right) {
+			struct tnode *newn;
+
+			newn = tnode_new(left->key, tn->pos + tn->bits, 1);
+
+			if (!newn)
+				goto nomem;
+
+			put_child(t, tn, i/2, (struct node *)newn);
+		}
+
+	}
+
+	for (i = 0; i < olen; i += 2) {
+		struct tnode *newBinNode;
+
+		left = tnode_get_child(oldtnode, i);
+		right = tnode_get_child(oldtnode, i+1);
+
+		/* At least one of the children is empty */
+		if (left == NULL) {
+			if (right == NULL)    /* Both are empty */
+				continue;
+			put_child(t, tn, i/2, right);
+			continue;
+		}
+
+		if (right == NULL) {
+			put_child(t, tn, i/2, left);
+			continue;
+		}
+
+		/* Two nonempty children */
+		newBinNode = (struct tnode *) tnode_get_child(tn, i/2);
+		put_child(t, tn, i/2, NULL);
+		put_child(t, newBinNode, 0, left);
+		put_child(t, newBinNode, 1, right);
+		put_child(t, tn, i/2, resize(t, newBinNode));
+	}
+	tnode_free(oldtnode);
+	return tn;
+nomem:
+	{
+		int size = tnode_child_length(tn);
+		int j;
+
+		for (j = 0; j < size; j++)
+			if (tn->child[j])
+				tnode_free((struct tnode *)tn->child[j]);
+
+		tnode_free(tn);
+
+		return ERR_PTR(-ENOMEM);
+	}
+}
+
+/* readside must use rcu_read_lock currently dump routines
+ via get_fa_head and dump */
+
+static struct leaf_info *find_leaf_info(struct leaf *l, int plen)
+{
+	struct hlist_head *head = &l->list;
+	struct hlist_node *node;
+	struct leaf_info *li;
+
+	hlist_for_each_entry_rcu(li, node, head, hlist)
+		if (li->plen == plen)
+			return li;
+
+	return NULL;
+}
+
+static inline struct list_head *get_fa_head(struct leaf *l, int plen)
+{
+	struct leaf_info *li = find_leaf_info(l, plen);
+
+	if (!li)
+		return NULL;
+
+	return &li->falh;
+}
+
+static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
+{
+	struct leaf_info *li = NULL, *last = NULL;
+	struct hlist_node *node;
+
+	if (hlist_empty(head)) {
+		hlist_add_head_rcu(&new->hlist, head);
+	} else {
+		hlist_for_each_entry(li, node, head, hlist) {
+			if (new->plen > li->plen)
+				break;
+
+			last = li;
+		}
+		if (last)
+			hlist_add_after_rcu(&last->hlist, &new->hlist);
+		else
+			hlist_add_before_rcu(&new->hlist, &li->hlist);
+	}
+}
+
+/* rcu_read_lock needs to be hold by caller from readside */
+
+static struct leaf *
+fib_find_node(struct trie *t, u32 key)
+{
+	int pos;
+	struct tnode *tn;
+	struct node *n;
+
+	pos = 0;
+	n = rcu_dereference(t->trie);
+
+	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
+		tn = (struct tnode *) n;
+
+		check_tnode(tn);
+
+		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
+			pos = tn->pos + tn->bits;
+			n = tnode_get_child_rcu(tn,
+						tkey_extract_bits(key,
+								  tn->pos,
+								  tn->bits));
+		} else
+			break;
+	}
+	/* Case we have found a leaf. Compare prefixes */
+
+	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key))
+		return (struct leaf *)n;
+
+	return NULL;
+}
+
+static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
+{
+	int wasfull;
+	t_key cindex, key = tn->key;
+	struct tnode *tp;
+
+	while (tn != NULL && (tp = node_parent((struct node *)tn)) != NULL) {
+		cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+		wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
+		tn = (struct tnode *) resize(t, (struct tnode *)tn);
+
+		tnode_put_child_reorg((struct tnode *)tp, cindex,
+				      (struct node *)tn, wasfull);
+
+		tp = node_parent((struct node *) tn);
+		if (!tp)
+			break;
+		tn = tp;
+	}
+
+	/* Handle last (top) tnode */
+	if (IS_TNODE(tn))
+		tn = (struct tnode *)resize(t, (struct tnode *)tn);
+
+	return (struct node *)tn;
+}
+
+/* only used from updater-side */
+
+static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
+{
+	int pos, newpos;
+	struct tnode *tp = NULL, *tn = NULL;
+	struct node *n;
+	struct leaf *l;
+	int missbit;
+	struct list_head *fa_head = NULL;
+	struct leaf_info *li;
+	t_key cindex;
+
+	pos = 0;
+	n = t->trie;
+
+	/* If we point to NULL, stop. Either the tree is empty and we should
+	 * just put a new leaf in if, or we have reached an empty child slot,
+	 * and we should just put our new leaf in that.
+	 * If we point to a T_TNODE, check if it matches our key. Note that
+	 * a T_TNODE might be skipping any number of bits - its 'pos' need
+	 * not be the parent's 'pos'+'bits'!
+	 *
+	 * If it does match the current key, get pos/bits from it, extract
+	 * the index from our key, push the T_TNODE and walk the tree.
+	 *
+	 * If it doesn't, we have to replace it with a new T_TNODE.
+	 *
+	 * If we point to a T_LEAF, it might or might not have the same key
+	 * as we do. If it does, just change the value, update the T_LEAF's
+	 * value, and return it.
+	 * If it doesn't, we need to replace it with a T_TNODE.
+	 */
+
+	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
+		tn = (struct tnode *) n;
+
+		check_tnode(tn);
+
+		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
+			tp = tn;
+			pos = tn->pos + tn->bits;
+			n = tnode_get_child(tn,
+					    tkey_extract_bits(key,
+							      tn->pos,
+							      tn->bits));
+
+			BUG_ON(n && node_parent(n) != tn);
+		} else
+			break;
+	}
+
+	/*
+	 * n  ----> NULL, LEAF or TNODE
+	 *
+	 * tp is n's (parent) ----> NULL or TNODE
+	 */
+
+	BUG_ON(tp && IS_LEAF(tp));
+
+	/* Case 1: n is a leaf. Compare prefixes */
+
+	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
+		l = (struct leaf *) n;
+		li = leaf_info_new(plen);
+
+		if (!li)
+			return NULL;
+
+		fa_head = &li->falh;
+		insert_leaf_info(&l->list, li);
+		goto done;
+	}
+	l = leaf_new();
+
+	if (!l)
+		return NULL;
+
+	l->key = key;
+	li = leaf_info_new(plen);
+
+	if (!li) {
+		free_leaf(l);
+		return NULL;
+	}
+
+	fa_head = &li->falh;
+	insert_leaf_info(&l->list, li);
+
+	if (t->trie && n == NULL) {
+		/* Case 2: n is NULL, and will just insert a new leaf */
+
+		node_set_parent((struct node *)l, tp);
+
+		cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+		put_child(t, (struct tnode *)tp, cindex, (struct node *)l);
+	} else {
+		/* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
+		/*
+		 *  Add a new tnode here
+		 *  first tnode need some special handling
+		 */
+
+		if (tp)
+			pos = tp->pos+tp->bits;
+		else
+			pos = 0;
+
+		if (n) {
+			newpos = tkey_mismatch(key, pos, n->key);
+			tn = tnode_new(n->key, newpos, 1);
+		} else {
+			newpos = 0;
+			tn = tnode_new(key, newpos, 1); /* First tnode */
+		}
+
+		if (!tn) {
+			free_leaf_info(li);
+			free_leaf(l);
+			return NULL;
+		}
+
+		node_set_parent((struct node *)tn, tp);
+
+		missbit = tkey_extract_bits(key, newpos, 1);
+		put_child(t, tn, missbit, (struct node *)l);
+		put_child(t, tn, 1-missbit, n);
+
+		if (tp) {
+			cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+			put_child(t, (struct tnode *)tp, cindex,
+				  (struct node *)tn);
+		} else {
+			rcu_assign_pointer(t->trie, (struct node *)tn);
+			tp = tn;
+		}
+	}
+
+	if (tp && tp->pos + tp->bits > 32)
+		pr_warning("fib_trie"
+			   " tp=%p pos=%d, bits=%d, key=%0x plen=%d\n",
+			   tp, tp->pos, tp->bits, key, plen);
+
+	/* Rebalance the trie */
+
+	rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
+done:
+	return fa_head;
+}
+
+/*
+ * Caller must hold RTNL.
+ */
+static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	struct fib_alias *fa, *new_fa;
+	struct list_head *fa_head = NULL;
+	struct fib_info *fi;
+	int plen = cfg->fc_dst_len;
+	u8 tos = cfg->fc_tos;
+	u32 key, mask;
+	int err;
+	struct leaf *l;
+
+	if (plen > 32)
+		return -EINVAL;
+
+	key = ntohl(cfg->fc_dst);
+
+	pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
+
+	mask = ntohl(inet_make_mask(plen));
+
+	if (key & ~mask)
+		return -EINVAL;
+
+	key = key & mask;
+
+	fi = fib_create_info(cfg);
+	if (IS_ERR(fi)) {
+		err = PTR_ERR(fi);
+		goto err;
+	}
+
+	l = fib_find_node(t, key);
+	fa = NULL;
+
+	if (l) {
+		fa_head = get_fa_head(l, plen);
+		fa = fib_find_alias(fa_head, tos, fi->fib_priority);
+	}
+
+	/* Now fa, if non-NULL, points to the first fib alias
+	 * with the same keys [prefix,tos,priority], if such key already
+	 * exists or to the node before which we will insert new one.
+	 *
+	 * If fa is NULL, we will need to allocate a new one and
+	 * insert to the head of f.
+	 *
+	 * If f is NULL, no fib node matched the destination key
+	 * and we need to allocate a new one of those as well.
+	 */
+
+	if (fa && fa->fa_tos == tos &&
+	    fa->fa_info->fib_priority == fi->fib_priority) {
+		struct fib_alias *fa_first, *fa_match;
+
+		err = -EEXIST;
+		if (cfg->fc_nlflags & NLM_F_EXCL)
+			goto out;
+
+		/* We have 2 goals:
+		 * 1. Find exact match for type, scope, fib_info to avoid
+		 * duplicate routes
+		 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
+		 */
+		fa_match = NULL;
+		fa_first = fa;
+		fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+		list_for_each_entry_continue(fa, fa_head, fa_list) {
+			if (fa->fa_tos != tos)
+				break;
+			if (fa->fa_info->fib_priority != fi->fib_priority)
+				break;
+			if (fa->fa_type == cfg->fc_type &&
+			    fa->fa_scope == cfg->fc_scope &&
+			    fa->fa_info == fi) {
+				fa_match = fa;
+				break;
+			}
+		}
+
+		if (cfg->fc_nlflags & NLM_F_REPLACE) {
+			struct fib_info *fi_drop;
+			u8 state;
+
+			fa = fa_first;
+			if (fa_match) {
+				if (fa == fa_match)
+					err = 0;
+				goto out;
+			}
+			err = -ENOBUFS;
+			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+			if (new_fa == NULL)
+				goto out;
+
+			fi_drop = fa->fa_info;
+			new_fa->fa_tos = fa->fa_tos;
+			new_fa->fa_info = fi;
+			new_fa->fa_type = cfg->fc_type;
+			new_fa->fa_scope = cfg->fc_scope;
+			state = fa->fa_state;
+			new_fa->fa_state = state & ~FA_S_ACCESSED;
+
+			list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
+			alias_free_mem_rcu(fa);
+
+			fib_release_info(fi_drop);
+			if (state & FA_S_ACCESSED)
+				rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+			rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen,
+				tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE);
+
+			goto succeeded;
+		}
+		/* Error if we find a perfect match which
+		 * uses the same scope, type, and nexthop
+		 * information.
+		 */
+		if (fa_match)
+			goto out;
+
+		if (!(cfg->fc_nlflags & NLM_F_APPEND))
+			fa = fa_first;
+	}
+	err = -ENOENT;
+	if (!(cfg->fc_nlflags & NLM_F_CREATE))
+		goto out;
+
+	err = -ENOBUFS;
+	new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
+	if (new_fa == NULL)
+		goto out;
+
+	new_fa->fa_info = fi;
+	new_fa->fa_tos = tos;
+	new_fa->fa_type = cfg->fc_type;
+	new_fa->fa_scope = cfg->fc_scope;
+	new_fa->fa_state = 0;
+	/*
+	 * Insert new entry to the list.
+	 */
+
+	if (!fa_head) {
+		fa_head = fib_insert_node(t, key, plen);
+		if (unlikely(!fa_head)) {
+			err = -ENOMEM;
+			goto out_free_new_fa;
+		}
+	}
+
+	list_add_tail_rcu(&new_fa->fa_list,
+			  (fa ? &fa->fa_list : fa_head));
+
+	rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
+		  &cfg->fc_nlinfo, 0);
+succeeded:
+	return 0;
+
+out_free_new_fa:
+	kmem_cache_free(fn_alias_kmem, new_fa);
+out:
+	fib_release_info(fi);
+err:
+	return err;
+}
+
+/* should be called with rcu_read_lock */
+static int check_leaf(struct trie *t, struct leaf *l,
+		      t_key key,  const struct flowi *flp,
+		      struct fib_result *res)
+{
+	struct leaf_info *li;
+	struct hlist_head *hhead = &l->list;
+	struct hlist_node *node;
+
+	hlist_for_each_entry_rcu(li, node, hhead, hlist) {
+		int err;
+		int plen = li->plen;
+		__be32 mask = inet_make_mask(plen);
+
+		if (l->key != (key & ntohl(mask)))
+			continue;
+
+		err = fib_semantic_match(&li->falh, flp, res,
+					 htonl(l->key), mask, plen);
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+		if (err <= 0)
+			t->stats.semantic_match_passed++;
+		else
+			t->stats.semantic_match_miss++;
+#endif
+		if (err <= 0)
+			return err;
+	}
+
+	return 1;
+}
+
+static int fn_trie_lookup(struct fib_table *tb, const struct flowi *flp,
+			  struct fib_result *res)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	int ret;
+	struct node *n;
+	struct tnode *pn;
+	int pos, bits;
+	t_key key = ntohl(flp->fl4_dst);
+	int chopped_off;
+	t_key cindex = 0;
+	int current_prefix_length = KEYLENGTH;
+	struct tnode *cn;
+	t_key node_prefix, key_prefix, pref_mismatch;
+	int mp;
+
+	rcu_read_lock();
+
+	n = rcu_dereference(t->trie);
+	if (!n)
+		goto failed;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+	t->stats.gets++;
+#endif
+
+	/* Just a leaf? */
+	if (IS_LEAF(n)) {
+		ret = check_leaf(t, (struct leaf *)n, key, flp, res);
+		goto found;
+	}
+
+	pn = (struct tnode *) n;
+	chopped_off = 0;
+
+	while (pn) {
+		pos = pn->pos;
+		bits = pn->bits;
+
+		if (!chopped_off)
+			cindex = tkey_extract_bits(mask_pfx(key, current_prefix_length),
+						   pos, bits);
+
+		n = tnode_get_child(pn, cindex);
+
+		if (n == NULL) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.null_node_hit++;
+#endif
+			goto backtrace;
+		}
+
+		if (IS_LEAF(n)) {
+			ret = check_leaf(t, (struct leaf *)n, key, flp, res);
+			if (ret > 0)
+				goto backtrace;
+			goto found;
+		}
+
+		cn = (struct tnode *)n;
+
+		/*
+		 * It's a tnode, and we can do some extra checks here if we
+		 * like, to avoid descending into a dead-end branch.
+		 * This tnode is in the parent's child array at index
+		 * key[p_pos..p_pos+p_bits] but potentially with some bits
+		 * chopped off, so in reality the index may be just a
+		 * subprefix, padded with zero at the end.
+		 * We can also take a look at any skipped bits in this
+		 * tnode - everything up to p_pos is supposed to be ok,
+		 * and the non-chopped bits of the index (se previous
+		 * paragraph) are also guaranteed ok, but the rest is
+		 * considered unknown.
+		 *
+		 * The skipped bits are key[pos+bits..cn->pos].
+		 */
+
+		/* If current_prefix_length < pos+bits, we are already doing
+		 * actual prefix  matching, which means everything from
+		 * pos+(bits-chopped_off) onward must be zero along some
+		 * branch of this subtree - otherwise there is *no* valid
+		 * prefix present. Here we can only check the skipped
+		 * bits. Remember, since we have already indexed into the
+		 * parent's child array, we know that the bits we chopped of
+		 * *are* zero.
+		 */
+
+		/* NOTA BENE: Checking only skipped bits
+		   for the new node here */
+
+		if (current_prefix_length < pos+bits) {
+			if (tkey_extract_bits(cn->key, current_prefix_length,
+						cn->pos - current_prefix_length)
+			    || !(cn->child[0]))
+				goto backtrace;
+		}
+
+		/*
+		 * If chopped_off=0, the index is fully validated and we
+		 * only need to look at the skipped bits for this, the new,
+		 * tnode. What we actually want to do is to find out if
+		 * these skipped bits match our key perfectly, or if we will
+		 * have to count on finding a matching prefix further down,
+		 * because if we do, we would like to have some way of
+		 * verifying the existence of such a prefix at this point.
+		 */
+
+		/* The only thing we can do at this point is to verify that
+		 * any such matching prefix can indeed be a prefix to our
+		 * key, and if the bits in the node we are inspecting that
+		 * do not match our key are not ZERO, this cannot be true.
+		 * Thus, find out where there is a mismatch (before cn->pos)
+		 * and verify that all the mismatching bits are zero in the
+		 * new tnode's key.
+		 */
+
+		/*
+		 * Note: We aren't very concerned about the piece of
+		 * the key that precede pn->pos+pn->bits, since these
+		 * have already been checked. The bits after cn->pos
+		 * aren't checked since these are by definition
+		 * "unknown" at this point. Thus, what we want to see
+		 * is if we are about to enter the "prefix matching"
+		 * state, and in that case verify that the skipped
+		 * bits that will prevail throughout this subtree are
+		 * zero, as they have to be if we are to find a
+		 * matching prefix.
+		 */
+
+		node_prefix = mask_pfx(cn->key, cn->pos);
+		key_prefix = mask_pfx(key, cn->pos);
+		pref_mismatch = key_prefix^node_prefix;
+		mp = 0;
+
+		/*
+		 * In short: If skipped bits in this node do not match
+		 * the search key, enter the "prefix matching"
+		 * state.directly.
+		 */
+		if (pref_mismatch) {
+			while (!(pref_mismatch & (1<<(KEYLENGTH-1)))) {
+				mp++;
+				pref_mismatch = pref_mismatch << 1;
+			}
+			key_prefix = tkey_extract_bits(cn->key, mp, cn->pos-mp);
+
+			if (key_prefix != 0)
+				goto backtrace;
+
+			if (current_prefix_length >= cn->pos)
+				current_prefix_length = mp;
+		}
+
+		pn = (struct tnode *)n; /* Descend */
+		chopped_off = 0;
+		continue;
+
+backtrace:
+		chopped_off++;
+
+		/* As zero don't change the child key (cindex) */
+		while ((chopped_off <= pn->bits)
+		       && !(cindex & (1<<(chopped_off-1))))
+			chopped_off++;
+
+		/* Decrease current_... with bits chopped off */
+		if (current_prefix_length > pn->pos + pn->bits - chopped_off)
+			current_prefix_length = pn->pos + pn->bits
+				- chopped_off;
+
+		/*
+		 * Either we do the actual chop off according or if we have
+		 * chopped off all bits in this tnode walk up to our parent.
+		 */
+
+		if (chopped_off <= pn->bits) {
+			cindex &= ~(1 << (chopped_off-1));
+		} else {
+			struct tnode *parent = node_parent((struct node *) pn);
+			if (!parent)
+				goto failed;
+
+			/* Get Child's index */
+			cindex = tkey_extract_bits(pn->key, parent->pos, parent->bits);
+			pn = parent;
+			chopped_off = 0;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			t->stats.backtrack++;
+#endif
+			goto backtrace;
+		}
+	}
+failed:
+	ret = 1;
+found:
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * Remove the leaf and return parent.
+ */
+static void trie_leaf_remove(struct trie *t, struct leaf *l)
+{
+	struct tnode *tp = node_parent((struct node *) l);
+
+	pr_debug("entering trie_leaf_remove(%p)\n", l);
+
+	if (tp) {
+		t_key cindex = tkey_extract_bits(l->key, tp->pos, tp->bits);
+		put_child(t, (struct tnode *)tp, cindex, NULL);
+		rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
+	} else
+		rcu_assign_pointer(t->trie, NULL);
+
+	free_leaf(l);
+}
+
+/*
+ * Caller must hold RTNL.
+ */
+static int fn_trie_delete(struct fib_table *tb, struct fib_config *cfg)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	u32 key, mask;
+	int plen = cfg->fc_dst_len;
+	u8 tos = cfg->fc_tos;
+	struct fib_alias *fa, *fa_to_delete;
+	struct list_head *fa_head;
+	struct leaf *l;
+	struct leaf_info *li;
+
+	if (plen > 32)
+		return -EINVAL;
+
+	key = ntohl(cfg->fc_dst);
+	mask = ntohl(inet_make_mask(plen));
+
+	if (key & ~mask)
+		return -EINVAL;
+
+	key = key & mask;
+	l = fib_find_node(t, key);
+
+	if (!l)
+		return -ESRCH;
+
+	fa_head = get_fa_head(l, plen);
+	fa = fib_find_alias(fa_head, tos, 0);
+
+	if (!fa)
+		return -ESRCH;
+
+	pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
+
+	fa_to_delete = NULL;
+	fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+	list_for_each_entry_continue(fa, fa_head, fa_list) {
+		struct fib_info *fi = fa->fa_info;
+
+		if (fa->fa_tos != tos)
+			break;
+
+		if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
+		    (cfg->fc_scope == RT_SCOPE_NOWHERE ||
+		     fa->fa_scope == cfg->fc_scope) &&
+		    (!cfg->fc_protocol ||
+		     fi->fib_protocol == cfg->fc_protocol) &&
+		    fib_nh_match(cfg, fi) == 0) {
+			fa_to_delete = fa;
+			break;
+		}
+	}
+
+	if (!fa_to_delete)
+		return -ESRCH;
+
+	fa = fa_to_delete;
+	rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
+		  &cfg->fc_nlinfo, 0);
+
+	l = fib_find_node(t, key);
+	li = find_leaf_info(l, plen);
+
+	list_del_rcu(&fa->fa_list);
+
+	if (list_empty(fa_head)) {
+		hlist_del_rcu(&li->hlist);
+		free_leaf_info(li);
+	}
+
+	if (hlist_empty(&l->list))
+		trie_leaf_remove(t, l);
+
+	if (fa->fa_state & FA_S_ACCESSED)
+		rt_cache_flush(cfg->fc_nlinfo.nl_net, -1);
+
+	fib_release_info(fa->fa_info);
+	alias_free_mem_rcu(fa);
+	return 0;
+}
+
+static int trie_flush_list(struct list_head *head)
+{
+	struct fib_alias *fa, *fa_node;
+	int found = 0;
+
+	list_for_each_entry_safe(fa, fa_node, head, fa_list) {
+		struct fib_info *fi = fa->fa_info;
+
+		if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
+			list_del_rcu(&fa->fa_list);
+			fib_release_info(fa->fa_info);
+			alias_free_mem_rcu(fa);
+			found++;
+		}
+	}
+	return found;
+}
+
+static int trie_flush_leaf(struct leaf *l)
+{
+	int found = 0;
+	struct hlist_head *lih = &l->list;
+	struct hlist_node *node, *tmp;
+	struct leaf_info *li = NULL;
+
+	hlist_for_each_entry_safe(li, node, tmp, lih, hlist) {
+		found += trie_flush_list(&li->falh);
+
+		if (list_empty(&li->falh)) {
+			hlist_del_rcu(&li->hlist);
+			free_leaf_info(li);
+		}
+	}
+	return found;
+}
+
+/*
+ * Scan for the next right leaf starting at node p->child[idx]
+ * Since we have back pointer, no recursion necessary.
+ */
+static struct leaf *leaf_walk_rcu(struct tnode *p, struct node *c)
+{
+	do {
+		t_key idx;
+
+		if (c)
+			idx = tkey_extract_bits(c->key, p->pos, p->bits) + 1;
+		else
+			idx = 0;
+
+		while (idx < 1u << p->bits) {
+			c = tnode_get_child_rcu(p, idx++);
+			if (!c)
+				continue;
+
+			if (IS_LEAF(c)) {
+				prefetch(p->child[idx]);
+				return (struct leaf *) c;
+			}
+
+			/* Rescan start scanning in new node */
+			p = (struct tnode *) c;
+			idx = 0;
+		}
+
+		/* Node empty, walk back up to parent */
+		c = (struct node *) p;
+	} while ( (p = node_parent_rcu(c)) != NULL);
+
+	return NULL; /* Root of trie */
+}
+
+static struct leaf *trie_firstleaf(struct trie *t)
+{
+	struct tnode *n = (struct tnode *) rcu_dereference(t->trie);
+
+	if (!n)
+		return NULL;
+
+	if (IS_LEAF(n))          /* trie is just a leaf */
+		return (struct leaf *) n;
+
+	return leaf_walk_rcu(n, NULL);
+}
+
+static struct leaf *trie_nextleaf(struct leaf *l)
+{
+	struct node *c = (struct node *) l;
+	struct tnode *p = node_parent(c);
+
+	if (!p)
+		return NULL;	/* trie with just one leaf */
+
+	return leaf_walk_rcu(p, c);
+}
+
+static struct leaf *trie_leafindex(struct trie *t, int index)
+{
+	struct leaf *l = trie_firstleaf(t);
+
+	while (l && index-- > 0)
+		l = trie_nextleaf(l);
+
+	return l;
+}
+
+
+/*
+ * Caller must hold RTNL.
+ */
+static int fn_trie_flush(struct fib_table *tb)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	struct leaf *l, *ll = NULL;
+	int found = 0;
+
+	for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
+		found += trie_flush_leaf(l);
+
+		if (ll && hlist_empty(&ll->list))
+			trie_leaf_remove(t, ll);
+		ll = l;
+	}
+
+	if (ll && hlist_empty(&ll->list))
+		trie_leaf_remove(t, ll);
+
+	pr_debug("trie_flush found=%d\n", found);
+	return found;
+}
+
+static void fn_trie_select_default(struct fib_table *tb,
+				   const struct flowi *flp,
+				   struct fib_result *res)
+{
+	struct trie *t = (struct trie *) tb->tb_data;
+	int order, last_idx;
+	struct fib_info *fi = NULL;
+	struct fib_info *last_resort;
+	struct fib_alias *fa = NULL;
+	struct list_head *fa_head;
+	struct leaf *l;
+
+	last_idx = -1;
+	last_resort = NULL;
+	order = -1;
+
+	rcu_read_lock();
+
+	l = fib_find_node(t, 0);
+	if (!l)
+		goto out;
+
+	fa_head = get_fa_head(l, 0);
+	if (!fa_head)
+		goto out;
+
+	if (list_empty(fa_head))
+		goto out;
+
+	list_for_each_entry_rcu(fa, fa_head, fa_list) {
+		struct fib_info *next_fi = fa->fa_info;
+
+		if (fa->fa_scope != res->scope ||
+		    fa->fa_type != RTN_UNICAST)
+			continue;
+
+		if (next_fi->fib_priority > res->fi->fib_priority)
+			break;
+		if (!next_fi->fib_nh[0].nh_gw ||
+		    next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK)
+			continue;
+		fa->fa_state |= FA_S_ACCESSED;
+
+		if (fi == NULL) {
+			if (next_fi != res->fi)
+				break;
+		} else if (!fib_detect_death(fi, order, &last_resort,
+					     &last_idx, tb->tb_default)) {
+			fib_result_assign(res, fi);
+			tb->tb_default = order;
+			goto out;
+		}
+		fi = next_fi;
+		order++;
+	}
+	if (order <= 0 || fi == NULL) {
+		tb->tb_default = -1;
+		goto out;
+	}
+
+	if (!fib_detect_death(fi, order, &last_resort, &last_idx,
+				tb->tb_default)) {
+		fib_result_assign(res, fi);
+		tb->tb_default = order;
+		goto out;
+	}
+	if (last_idx >= 0)
+		fib_result_assign(res, last_resort);
+	tb->tb_default = last_idx;
+out:
+	rcu_read_unlock();
+}
+
+static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
+			   struct fib_table *tb,
+			   struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int i, s_i;
+	struct fib_alias *fa;
+	__be32 xkey = htonl(key);
+
+	s_i = cb->args[5];
+	i = 0;
+
+	/* rcu_read_lock is hold by caller */
+
+	list_for_each_entry_rcu(fa, fah, fa_list) {
+		if (i < s_i) {
+			i++;
+			continue;
+		}
+
+		if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid,
+				  cb->nlh->nlmsg_seq,
+				  RTM_NEWROUTE,
+				  tb->tb_id,
+				  fa->fa_type,
+				  fa->fa_scope,
+				  xkey,
+				  plen,
+				  fa->fa_tos,
+				  fa->fa_info, NLM_F_MULTI) < 0) {
+			cb->args[5] = i;
+			return -1;
+		}
+		i++;
+	}
+	cb->args[5] = i;
+	return skb->len;
+}
+
+static int fn_trie_dump_leaf(struct leaf *l, struct fib_table *tb,
+			struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct leaf_info *li;
+	struct hlist_node *node;
+	int i, s_i;
+
+	s_i = cb->args[4];
+	i = 0;
+
+	/* rcu_read_lock is hold by caller */
+	hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
+		if (i < s_i) {
+			i++;
+			continue;
+		}
+
+		if (i > s_i)
+			cb->args[5] = 0;
+
+		if (list_empty(&li->falh))
+			continue;
+
+		if (fn_trie_dump_fa(l->key, li->plen, &li->falh, tb, skb, cb) < 0) {
+			cb->args[4] = i;
+			return -1;
+		}
+		i++;
+	}
+
+	cb->args[4] = i;
+	return skb->len;
+}
+
+static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb,
+			struct netlink_callback *cb)
+{
+	struct leaf *l;
+	struct trie *t = (struct trie *) tb->tb_data;
+	t_key key = cb->args[2];
+	int count = cb->args[3];
+
+	rcu_read_lock();
+	/* Dump starting at last key.
+	 * Note: 0.0.0.0/0 (ie default) is first key.
+	 */
+	if (count == 0)
+		l = trie_firstleaf(t);
+	else {
+		/* Normally, continue from last key, but if that is missing
+		 * fallback to using slow rescan
+		 */
+		l = fib_find_node(t, key);
+		if (!l)
+			l = trie_leafindex(t, count);
+	}
+
+	while (l) {
+		cb->args[2] = l->key;
+		if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
+			cb->args[3] = count;
+			rcu_read_unlock();
+			return -1;
+		}
+
+		++count;
+		l = trie_nextleaf(l);
+		memset(&cb->args[4], 0,
+		       sizeof(cb->args) - 4*sizeof(cb->args[0]));
+	}
+	cb->args[3] = count;
+	rcu_read_unlock();
+
+	return skb->len;
+}
+
+void __init fib_hash_init(void)
+{
+	fn_alias_kmem = kmem_cache_create("ip_fib_alias",
+					  sizeof(struct fib_alias),
+					  0, SLAB_PANIC, NULL);
+
+	trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
+					   max(sizeof(struct leaf),
+					       sizeof(struct leaf_info)),
+					   0, SLAB_PANIC, NULL);
+}
+
+
+/* Fix more generic FIB names for init later */
+struct fib_table *fib_hash_table(u32 id)
+{
+	struct fib_table *tb;
+	struct trie *t;
+
+	tb = kmalloc(sizeof(struct fib_table) + sizeof(struct trie),
+		     GFP_KERNEL);
+	if (tb == NULL)
+		return NULL;
+
+	tb->tb_id = id;
+	tb->tb_default = -1;
+	tb->tb_lookup = fn_trie_lookup;
+	tb->tb_insert = fn_trie_insert;
+	tb->tb_delete = fn_trie_delete;
+	tb->tb_flush = fn_trie_flush;
+	tb->tb_select_default = fn_trie_select_default;
+	tb->tb_dump = fn_trie_dump;
+
+	t = (struct trie *) tb->tb_data;
+	memset(t, 0, sizeof(*t));
+
+	if (id == RT_TABLE_LOCAL)
+		pr_info("IPv4 FIB: Using LC-trie version %s\n", VERSION);
+
+	return tb;
+}
+
+#ifdef CONFIG_PROC_FS
+/* Depth first Trie walk iterator */
+struct fib_trie_iter {
+	struct seq_net_private p;
+	struct fib_table *tb;
+	struct tnode *tnode;
+	unsigned index;
+	unsigned depth;
+};
+
+static struct node *fib_trie_get_next(struct fib_trie_iter *iter)
+{
+	struct tnode *tn = iter->tnode;
+	unsigned cindex = iter->index;
+	struct tnode *p;
+
+	/* A single entry routing table */
+	if (!tn)
+		return NULL;
+
+	pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
+		 iter->tnode, iter->index, iter->depth);
+rescan:
+	while (cindex < (1<<tn->bits)) {
+		struct node *n = tnode_get_child_rcu(tn, cindex);
+
+		if (n) {
+			if (IS_LEAF(n)) {
+				iter->tnode = tn;
+				iter->index = cindex + 1;
+			} else {
+				/* push down one level */
+				iter->tnode = (struct tnode *) n;
+				iter->index = 0;
+				++iter->depth;
+			}
+			return n;
+		}
+
+		++cindex;
+	}
+
+	/* Current node exhausted, pop back up */
+	p = node_parent_rcu((struct node *)tn);
+	if (p) {
+		cindex = tkey_extract_bits(tn->key, p->pos, p->bits)+1;
+		tn = p;
+		--iter->depth;
+		goto rescan;
+	}
+
+	/* got root? */
+	return NULL;
+}
+
+static struct node *fib_trie_get_first(struct fib_trie_iter *iter,
+				       struct trie *t)
+{
+	struct node *n;
+
+	if (!t)
+		return NULL;
+
+	n = rcu_dereference(t->trie);
+	if (!n)
+		return NULL;
+
+	if (IS_TNODE(n)) {
+		iter->tnode = (struct tnode *) n;
+		iter->index = 0;
+		iter->depth = 1;
+	} else {
+		iter->tnode = NULL;
+		iter->index = 0;
+		iter->depth = 0;
+	}
+
+	return n;
+}
+
+static void trie_collect_stats(struct trie *t, struct trie_stat *s)
+{
+	struct node *n;
+	struct fib_trie_iter iter;
+
+	memset(s, 0, sizeof(*s));
+
+	rcu_read_lock();
+	for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {
+		if (IS_LEAF(n)) {
+			struct leaf *l = (struct leaf *)n;
+			struct leaf_info *li;
+			struct hlist_node *tmp;
+
+			s->leaves++;
+			s->totdepth += iter.depth;
+			if (iter.depth > s->maxdepth)
+				s->maxdepth = iter.depth;
+
+			hlist_for_each_entry_rcu(li, tmp, &l->list, hlist)
+				++s->prefixes;
+		} else {
+			const struct tnode *tn = (const struct tnode *) n;
+			int i;
+
+			s->tnodes++;
+			if (tn->bits < MAX_STAT_DEPTH)
+				s->nodesizes[tn->bits]++;
+
+			for (i = 0; i < (1<<tn->bits); i++)
+				if (!tn->child[i])
+					s->nullpointers++;
+		}
+	}
+	rcu_read_unlock();
+}
+
+/*
+ *	This outputs /proc/net/fib_triestats
+ */
+static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
+{
+	unsigned i, max, pointers, bytes, avdepth;
+
+	if (stat->leaves)
+		avdepth = stat->totdepth*100 / stat->leaves;
+	else
+		avdepth = 0;
+
+	seq_printf(seq, "\tAver depth:     %u.%02d\n",
+		   avdepth / 100, avdepth % 100);
+	seq_printf(seq, "\tMax depth:      %u\n", stat->maxdepth);
+
+	seq_printf(seq, "\tLeaves:         %u\n", stat->leaves);
+	bytes = sizeof(struct leaf) * stat->leaves;
+
+	seq_printf(seq, "\tPrefixes:       %u\n", stat->prefixes);
+	bytes += sizeof(struct leaf_info) * stat->prefixes;
+
+	seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);
+	bytes += sizeof(struct tnode) * stat->tnodes;
+
+	max = MAX_STAT_DEPTH;
+	while (max > 0 && stat->nodesizes[max-1] == 0)
+		max--;
+
+	pointers = 0;
+	for (i = 1; i <= max; i++)
+		if (stat->nodesizes[i] != 0) {
+			seq_printf(seq, "  %u: %u",  i, stat->nodesizes[i]);
+			pointers += (1<<i) * stat->nodesizes[i];
+		}
+	seq_putc(seq, '\n');
+	seq_printf(seq, "\tPointers: %u\n", pointers);
+
+	bytes += sizeof(struct node *) * pointers;
+	seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
+	seq_printf(seq, "Total size: %u  kB\n", (bytes + 1023) / 1024);
+}
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+static void trie_show_usage(struct seq_file *seq,
+			    const struct trie_use_stats *stats)
+{
+	seq_printf(seq, "\nCounters:\n---------\n");
+	seq_printf(seq, "gets = %u\n", stats->gets);
+	seq_printf(seq, "backtracks = %u\n", stats->backtrack);
+	seq_printf(seq, "semantic match passed = %u\n",
+		   stats->semantic_match_passed);
+	seq_printf(seq, "semantic match miss = %u\n",
+		   stats->semantic_match_miss);
+	seq_printf(seq, "null node hit= %u\n", stats->null_node_hit);
+	seq_printf(seq, "skipped node resize = %u\n\n",
+		   stats->resize_node_skipped);
+}
+#endif /*  CONFIG_IP_FIB_TRIE_STATS */
+
+static void fib_table_print(struct seq_file *seq, struct fib_table *tb)
+{
+	if (tb->tb_id == RT_TABLE_LOCAL)
+		seq_puts(seq, "Local:\n");
+	else if (tb->tb_id == RT_TABLE_MAIN)
+		seq_puts(seq, "Main:\n");
+	else
+		seq_printf(seq, "Id %d:\n", tb->tb_id);
+}
+
+
+static int fib_triestat_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = (struct net *)seq->private;
+	unsigned int h;
+
+	seq_printf(seq,
+		   "Basic info: size of leaf:"
+		   " %Zd bytes, size of tnode: %Zd bytes.\n",
+		   sizeof(struct leaf), sizeof(struct tnode));
+
+	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		struct hlist_node *node;
+		struct fib_table *tb;
+
+		hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+			struct trie *t = (struct trie *) tb->tb_data;
+			struct trie_stat stat;
+
+			if (!t)
+				continue;
+
+			fib_table_print(seq, tb);
+
+			trie_collect_stats(t, &stat);
+			trie_show_stats(seq, &stat);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+			trie_show_usage(seq, &t->stats);
+#endif
+		}
+	}
+
+	return 0;
+}
+
+static int fib_triestat_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open_net(inode, file, fib_triestat_seq_show);
+}
+
+static const struct file_operations fib_triestat_fops = {
+	.owner	= THIS_MODULE,
+	.open	= fib_triestat_seq_open,
+	.read	= seq_read,
+	.llseek	= seq_lseek,
+	.release = single_release_net,
+};
+
+static struct node *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct fib_trie_iter *iter = seq->private;
+	struct net *net = seq_file_net(seq);
+	loff_t idx = 0;
+	unsigned int h;
+
+	for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		struct hlist_node *node;
+		struct fib_table *tb;
+
+		hlist_for_each_entry_rcu(tb, node, head, tb_hlist) {
+			struct node *n;
+
+			for (n = fib_trie_get_first(iter,
+						    (struct trie *) tb->tb_data);
+			     n; n = fib_trie_get_next(iter))
+				if (pos == idx++) {
+					iter->tb = tb;
+					return n;
+				}
+		}
+	}
+
+	return NULL;
+}
+
+static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
+{
+	rcu_read_lock();
+	return fib_trie_get_idx(seq, *pos);
+}
+
+static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct fib_trie_iter *iter = seq->private;
+	struct net *net = seq_file_net(seq);
+	struct fib_table *tb = iter->tb;
+	struct hlist_node *tb_node;
+	unsigned int h;
+	struct node *n;
+
+	++*pos;
+	/* next node in same table */
+	n = fib_trie_get_next(iter);
+	if (n)
+		return n;
+
+	/* walk rest of this hash chain */
+	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
+	while ( (tb_node = rcu_dereference(tb->tb_hlist.next)) ) {
+		tb = hlist_entry(tb_node, struct fib_table, tb_hlist);
+		n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
+		if (n)
+			goto found;
+	}
+
+	/* new hash chain */
+	while (++h < FIB_TABLE_HASHSZ) {
+		struct hlist_head *head = &net->ipv4.fib_table_hash[h];
+		hlist_for_each_entry_rcu(tb, tb_node, head, tb_hlist) {
+			n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);
+			if (n)
+				goto found;
+		}
+	}
+	return NULL;
+
+found:
+	iter->tb = tb;
+	return n;
+}
+
+static void fib_trie_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static void seq_indent(struct seq_file *seq, int n)
+{
+	while (n-- > 0) seq_puts(seq, "   ");
+}
+
+static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
+{
+	switch (s) {
+	case RT_SCOPE_UNIVERSE: return "universe";
+	case RT_SCOPE_SITE:	return "site";
+	case RT_SCOPE_LINK:	return "link";
+	case RT_SCOPE_HOST:	return "host";
+	case RT_SCOPE_NOWHERE:	return "nowhere";
+	default:
+		snprintf(buf, len, "scope=%d", s);
+		return buf;
+	}
+}
+
+static const char *rtn_type_names[__RTN_MAX] = {
+	[RTN_UNSPEC] = "UNSPEC",
+	[RTN_UNICAST] = "UNICAST",
+	[RTN_LOCAL] = "LOCAL",
+	[RTN_BROADCAST] = "BROADCAST",
+	[RTN_ANYCAST] = "ANYCAST",
+	[RTN_MULTICAST] = "MULTICAST",
+	[RTN_BLACKHOLE] = "BLACKHOLE",
+	[RTN_UNREACHABLE] = "UNREACHABLE",
+	[RTN_PROHIBIT] = "PROHIBIT",
+	[RTN_THROW] = "THROW",
+	[RTN_NAT] = "NAT",
+	[RTN_XRESOLVE] = "XRESOLVE",
+};
+
+static inline const char *rtn_type(char *buf, size_t len, unsigned t)
+{
+	if (t < __RTN_MAX && rtn_type_names[t])
+		return rtn_type_names[t];
+	snprintf(buf, len, "type %u", t);
+	return buf;
+}
+
+/* Pretty print the trie */
+static int fib_trie_seq_show(struct seq_file *seq, void *v)
+{
+	const struct fib_trie_iter *iter = seq->private;
+	struct node *n = v;
+
+	if (!node_parent_rcu(n))
+		fib_table_print(seq, iter->tb);
+
+	if (IS_TNODE(n)) {
+		struct tnode *tn = (struct tnode *) n;
+		__be32 prf = htonl(mask_pfx(tn->key, tn->pos));
+
+		seq_indent(seq, iter->depth-1);
+		seq_printf(seq, "  +-- " NIPQUAD_FMT "/%d %d %d %d\n",
+			   NIPQUAD(prf), tn->pos, tn->bits, tn->full_children,
+			   tn->empty_children);
+
+	} else {
+		struct leaf *l = (struct leaf *) n;
+		struct leaf_info *li;
+		struct hlist_node *node;
+		__be32 val = htonl(l->key);
+
+		seq_indent(seq, iter->depth);
+		seq_printf(seq, "  |-- " NIPQUAD_FMT "\n", NIPQUAD(val));
+
+		hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
+			struct fib_alias *fa;
+
+			list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+				char buf1[32], buf2[32];
+
+				seq_indent(seq, iter->depth+1);
+				seq_printf(seq, "  /%d %s %s", li->plen,
+					   rtn_scope(buf1, sizeof(buf1),
+						     fa->fa_scope),
+					   rtn_type(buf2, sizeof(buf2),
+						    fa->fa_type));
+				if (fa->fa_tos)
+					seq_printf(seq, " tos=%d", fa->fa_tos);
+				seq_putc(seq, '\n');
+			}
+		}
+	}
+
+	return 0;
+}
+
+static const struct seq_operations fib_trie_seq_ops = {
+	.start  = fib_trie_seq_start,
+	.next   = fib_trie_seq_next,
+	.stop   = fib_trie_seq_stop,
+	.show   = fib_trie_seq_show,
+};
+
+static int fib_trie_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &fib_trie_seq_ops,
+			    sizeof(struct fib_trie_iter));
+}
+
+static const struct file_operations fib_trie_fops = {
+	.owner  = THIS_MODULE,
+	.open   = fib_trie_seq_open,
+	.read   = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release_net,
+};
+
+struct fib_route_iter {
+	struct seq_net_private p;
+	struct trie *main_trie;
+	loff_t	pos;
+	t_key	key;
+};
+
+static struct leaf *fib_route_get_idx(struct fib_route_iter *iter, loff_t pos)
+{
+	struct leaf *l = NULL;
+	struct trie *t = iter->main_trie;
+
+	/* use cache location of last found key */
+	if (iter->pos > 0 && pos >= iter->pos && (l = fib_find_node(t, iter->key)))
+		pos -= iter->pos;
+	else {
+		iter->pos = 0;
+		l = trie_firstleaf(t);
+	}
+
+	while (l && pos-- > 0) {
+		iter->pos++;
+		l = trie_nextleaf(l);
+	}
+
+	if (l)
+		iter->key = pos;	/* remember it */
+	else
+		iter->pos = 0;		/* forget it */
+
+	return l;
+}
+
+static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
+{
+	struct fib_route_iter *iter = seq->private;
+	struct fib_table *tb;
+
+	rcu_read_lock();
+	tb = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN);
+	if (!tb)
+		return NULL;
+
+	iter->main_trie = (struct trie *) tb->tb_data;
+	if (*pos == 0)
+		return SEQ_START_TOKEN;
+	else
+		return fib_route_get_idx(iter, *pos - 1);
+}
+
+static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct fib_route_iter *iter = seq->private;
+	struct leaf *l = v;
+
+	++*pos;
+	if (v == SEQ_START_TOKEN) {
+		iter->pos = 0;
+		l = trie_firstleaf(iter->main_trie);
+	} else {
+		iter->pos++;
+		l = trie_nextleaf(l);
+	}
+
+	if (l)
+		iter->key = l->key;
+	else
+		iter->pos = 0;
+	return l;
+}
+
+static void fib_route_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static unsigned fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
+{
+	static unsigned type2flags[RTN_MAX + 1] = {
+		[7] = RTF_REJECT, [8] = RTF_REJECT,
+	};
+	unsigned flags = type2flags[type];
+
+	if (fi && fi->fib_nh->nh_gw)
+		flags |= RTF_GATEWAY;
+	if (mask == htonl(0xFFFFFFFF))
+		flags |= RTF_HOST;
+	flags |= RTF_UP;
+	return flags;
+}
+
+/*
+ *	This outputs /proc/net/route.
+ *	The format of the file is not supposed to be changed
+ * 	and needs to be same as fib_hash output to avoid breaking
+ *	legacy utilities
+ */
+static int fib_route_seq_show(struct seq_file *seq, void *v)
+{
+	struct leaf *l = v;
+	struct leaf_info *li;
+	struct hlist_node *node;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway "
+			   "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU"
+			   "\tWindow\tIRTT");
+		return 0;
+	}
+
+	hlist_for_each_entry_rcu(li, node, &l->list, hlist) {
+		struct fib_alias *fa;
+		__be32 mask, prefix;
+
+		mask = inet_make_mask(li->plen);
+		prefix = htonl(l->key);
+
+		list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+			const struct fib_info *fi = fa->fa_info;
+			unsigned flags = fib_flag_trans(fa->fa_type, mask, fi);
+			int len;
+
+			if (fa->fa_type == RTN_BROADCAST
+			    || fa->fa_type == RTN_MULTICAST)
+				continue;
+
+			if (fi)
+				seq_printf(seq,
+					 "%s\t%08X\t%08X\t%04X\t%d\t%u\t"
+					 "%d\t%08X\t%d\t%u\t%u%n",
+					 fi->fib_dev ? fi->fib_dev->name : "*",
+					 prefix,
+					 fi->fib_nh->nh_gw, flags, 0, 0,
+					 fi->fib_priority,
+					 mask,
+					 (fi->fib_advmss ?
+					  fi->fib_advmss + 40 : 0),
+					 fi->fib_window,
+					 fi->fib_rtt >> 3, &len);
+			else
+				seq_printf(seq,
+					 "*\t%08X\t%08X\t%04X\t%d\t%u\t"
+					 "%d\t%08X\t%d\t%u\t%u%n",
+					 prefix, 0, flags, 0, 0, 0,
+					 mask, 0, 0, 0, &len);
+
+			seq_printf(seq, "%*s\n", 127 - len, "");
+		}
+	}
+
+	return 0;
+}
+
+static const struct seq_operations fib_route_seq_ops = {
+	.start  = fib_route_seq_start,
+	.next   = fib_route_seq_next,
+	.stop   = fib_route_seq_stop,
+	.show   = fib_route_seq_show,
+};
+
+static int fib_route_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &fib_route_seq_ops,
+			    sizeof(struct fib_route_iter));
+}
+
+static const struct file_operations fib_route_fops = {
+	.owner  = THIS_MODULE,
+	.open   = fib_route_seq_open,
+	.read   = seq_read,
+	.llseek = seq_lseek,
+	.release = seq_release_net,
+};
+
+int __net_init fib_proc_init(struct net *net)
+{
+	if (!proc_net_fops_create(net, "fib_trie", S_IRUGO, &fib_trie_fops))
+		goto out1;
+
+	if (!proc_net_fops_create(net, "fib_triestat", S_IRUGO,
+				  &fib_triestat_fops))
+		goto out2;
+
+	if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_route_fops))
+		goto out3;
+
+	return 0;
+
+out3:
+	proc_net_remove(net, "fib_triestat");
+out2:
+	proc_net_remove(net, "fib_trie");
+out1:
+	return -ENOMEM;
+}
+
+void __net_exit fib_proc_exit(struct net *net)
+{
+	proc_net_remove(net, "fib_trie");
+	proc_net_remove(net, "fib_triestat");
+	proc_net_remove(net, "route");
+}
+
+#endif /* CONFIG_PROC_FS */
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
new file mode 100644
index 0000000..72b2de7
--- /dev/null
+++ b/net/ipv4/icmp.c
@@ -0,0 +1,1216 @@
+/*
+ *	NET3:	Implementation of the ICMP protocol layer.
+ *
+ *		Alan Cox, <alan@lxorguk.ukuu.org.uk>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	Some of the function names and the icmp unreach table for this
+ *	module were derived from [icmp.c 1.0.11 06/02/93] by
+ *	Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting.
+ *	Other than that this module is a complete rewrite.
+ *
+ *	Fixes:
+ *	Clemens Fruhwirth	:	introduce global icmp rate limiting
+ *					with icmp type masking ability instead
+ *					of broken per type icmp timeouts.
+ *		Mike Shaver	:	RFC1122 checks.
+ *		Alan Cox	:	Multicast ping reply as self.
+ *		Alan Cox	:	Fix atomicity lockup in ip_build_xmit
+ *					call.
+ *		Alan Cox	:	Added 216,128 byte paths to the MTU
+ *					code.
+ *		Martin Mares	:	RFC1812 checks.
+ *		Martin Mares	:	Can be configured to follow redirects
+ *					if acting as a router _without_ a
+ *					routing protocol (RFC 1812).
+ *		Martin Mares	:	Echo requests may be configured to
+ *					be ignored (RFC 1812).
+ *		Martin Mares	:	Limitation of ICMP error message
+ *					transmit rate (RFC 1812).
+ *		Martin Mares	:	TOS and Precedence set correctly
+ *					(RFC 1812).
+ *		Martin Mares	:	Now copying as much data from the
+ *					original packet as we can without
+ *					exceeding 576 bytes (RFC 1812).
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		Keith Owens	:	RFC1191 correction for 4.2BSD based
+ *					path MTU bug.
+ *		Thomas Quinot	:	ICMP Dest Unreach codes up to 15 are
+ *					valid (RFC 1812).
+ *		Andi Kleen	:	Check all packet lengths properly
+ *					and moved all kfree_skb() up to
+ *					icmp_rcv.
+ *		Andi Kleen	:	Move the rate limit bookkeeping
+ *					into the dest entry and use a token
+ *					bucket filter (thanks to ANK). Make
+ *					the rates sysctl configurable.
+ *		Yu Tianli	:	Fixed two ugly bugs in icmp_send
+ *					- IP option length was accounted wrongly
+ *					- ICMP header length was not accounted
+ *					  at all.
+ *              Tristan Greaves :       Added sysctl option to ignore bogus
+ *              			broadcast responses from broken routers.
+ *
+ * To Fix:
+ *
+ *	- Should use skb_pull() instead of all the manual checking.
+ *	  This would also greatly simply some upper layer error handlers. --AK
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/fcntl.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/string.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/protocol.h>
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/raw.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/init.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+#include <net/inet_common.h>
+
+/*
+ *	Build xmit assembly blocks
+ */
+
+struct icmp_bxm {
+	struct sk_buff *skb;
+	int offset;
+	int data_len;
+
+	struct {
+		struct icmphdr icmph;
+		__be32	       times[3];
+	} data;
+	int head_len;
+	struct ip_options replyopts;
+	unsigned char  optbuf[40];
+};
+
+/* An array of errno for error messages from dest unreach. */
+/* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */
+
+struct icmp_err icmp_err_convert[] = {
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_UNREACH */
+		.fatal = 0,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_HOST_UNREACH */
+		.fatal = 0,
+	},
+	{
+		.errno = ENOPROTOOPT	/* ICMP_PROT_UNREACH */,
+		.fatal = 1,
+	},
+	{
+		.errno = ECONNREFUSED,	/* ICMP_PORT_UNREACH */
+		.fatal = 1,
+	},
+	{
+		.errno = EMSGSIZE,	/* ICMP_FRAG_NEEDED */
+		.fatal = 0,
+	},
+	{
+		.errno = EOPNOTSUPP,	/* ICMP_SR_FAILED */
+		.fatal = 0,
+	},
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_UNKNOWN */
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTDOWN,	/* ICMP_HOST_UNKNOWN */
+		.fatal = 1,
+	},
+	{
+		.errno = ENONET,	/* ICMP_HOST_ISOLATED */
+		.fatal = 1,
+	},
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_ANO	*/
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_HOST_ANO */
+		.fatal = 1,
+	},
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_UNR_TOS */
+		.fatal = 0,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_HOST_UNR_TOS */
+		.fatal = 0,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_PKT_FILTERED */
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_PREC_VIOLATION */
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_PREC_CUTOFF */
+		.fatal = 1,
+	},
+};
+
+/*
+ *	ICMP control array. This specifies what to do with each ICMP.
+ */
+
+struct icmp_control {
+	void (*handler)(struct sk_buff *skb);
+	short   error;		/* This ICMP is classed as an error message */
+};
+
+static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
+
+/*
+ *	The ICMP socket(s). This is the most convenient way to flow control
+ *	our ICMP output as well as maintain a clean interface throughout
+ *	all layers. All Socketless IP sends will soon be gone.
+ *
+ *	On SMP we have one ICMP socket per-cpu.
+ */
+static struct sock *icmp_sk(struct net *net)
+{
+	return net->ipv4.icmp_sk[smp_processor_id()];
+}
+
+static inline struct sock *icmp_xmit_lock(struct net *net)
+{
+	struct sock *sk;
+
+	local_bh_disable();
+
+	sk = icmp_sk(net);
+
+	if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
+		/* This can happen if the output path signals a
+		 * dst_link_failure() for an outgoing ICMP packet.
+		 */
+		local_bh_enable();
+		return NULL;
+	}
+	return sk;
+}
+
+static inline void icmp_xmit_unlock(struct sock *sk)
+{
+	spin_unlock_bh(&sk->sk_lock.slock);
+}
+
+/*
+ *	Send an ICMP frame.
+ */
+
+/*
+ *	Check transmit rate limitation for given message.
+ *	The rate information is held in the destination cache now.
+ *	This function is generic and could be used for other purposes
+ *	too. It uses a Token bucket filter as suggested by Alexey Kuznetsov.
+ *
+ *	Note that the same dst_entry fields are modified by functions in
+ *	route.c too, but these work for packet destinations while xrlim_allow
+ *	works for icmp destinations. This means the rate limiting information
+ *	for one "ip object" is shared - and these ICMPs are twice limited:
+ *	by source and by destination.
+ *
+ *	RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
+ *			  SHOULD allow setting of rate limits
+ *
+ * 	Shared between ICMPv4 and ICMPv6.
+ */
+#define XRLIM_BURST_FACTOR 6
+int xrlim_allow(struct dst_entry *dst, int timeout)
+{
+	unsigned long now, token = dst->rate_tokens;
+	int rc = 0;
+
+	now = jiffies;
+	token += now - dst->rate_last;
+	dst->rate_last = now;
+	if (token > XRLIM_BURST_FACTOR * timeout)
+		token = XRLIM_BURST_FACTOR * timeout;
+	if (token >= timeout) {
+		token -= timeout;
+		rc = 1;
+	}
+	dst->rate_tokens = token;
+	return rc;
+}
+
+static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
+		int type, int code)
+{
+	struct dst_entry *dst = &rt->u.dst;
+	int rc = 1;
+
+	if (type > NR_ICMP_TYPES)
+		goto out;
+
+	/* Don't limit PMTU discovery. */
+	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+		goto out;
+
+	/* No rate limit on loopback */
+	if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
+		goto out;
+
+	/* Limit if icmp type is enabled in ratemask. */
+	if ((1 << type) & net->ipv4.sysctl_icmp_ratemask)
+		rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit);
+out:
+	return rc;
+}
+
+/*
+ *	Maintain the counters used in the SNMP statistics for outgoing ICMP
+ */
+void icmp_out_count(struct net *net, unsigned char type)
+{
+	ICMPMSGOUT_INC_STATS(net, type);
+	ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS);
+}
+
+/*
+ *	Checksum each fragment, and on the first include the headers and final
+ *	checksum.
+ */
+static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
+			  struct sk_buff *skb)
+{
+	struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
+	__wsum csum;
+
+	csum = skb_copy_and_csum_bits(icmp_param->skb,
+				      icmp_param->offset + offset,
+				      to, len, 0);
+
+	skb->csum = csum_block_add(skb->csum, csum, odd);
+	if (icmp_pointers[icmp_param->data.icmph.type].error)
+		nf_ct_attach(skb, icmp_param->skb);
+	return 0;
+}
+
+static void icmp_push_reply(struct icmp_bxm *icmp_param,
+			    struct ipcm_cookie *ipc, struct rtable *rt)
+{
+	struct sock *sk;
+	struct sk_buff *skb;
+
+	sk = icmp_sk(dev_net(rt->u.dst.dev));
+	if (ip_append_data(sk, icmp_glue_bits, icmp_param,
+			   icmp_param->data_len+icmp_param->head_len,
+			   icmp_param->head_len,
+			   ipc, rt, MSG_DONTWAIT) < 0)
+		ip_flush_pending_frames(sk);
+	else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
+		struct icmphdr *icmph = icmp_hdr(skb);
+		__wsum csum = 0;
+		struct sk_buff *skb1;
+
+		skb_queue_walk(&sk->sk_write_queue, skb1) {
+			csum = csum_add(csum, skb1->csum);
+		}
+		csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
+						 (char *)icmph,
+						 icmp_param->head_len, csum);
+		icmph->checksum = csum_fold(csum);
+		skb->ip_summed = CHECKSUM_NONE;
+		ip_push_pending_frames(sk);
+	}
+}
+
+/*
+ *	Driving logic for building and sending ICMP messages.
+ */
+
+static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
+{
+	struct ipcm_cookie ipc;
+	struct rtable *rt = skb->rtable;
+	struct net *net = dev_net(rt->u.dst.dev);
+	struct sock *sk;
+	struct inet_sock *inet;
+	__be32 daddr;
+
+	if (ip_options_echo(&icmp_param->replyopts, skb))
+		return;
+
+	sk = icmp_xmit_lock(net);
+	if (sk == NULL)
+		return;
+	inet = inet_sk(sk);
+
+	icmp_param->data.icmph.checksum = 0;
+
+	inet->tos = ip_hdr(skb)->tos;
+	daddr = ipc.addr = rt->rt_src;
+	ipc.opt = NULL;
+	if (icmp_param->replyopts.optlen) {
+		ipc.opt = &icmp_param->replyopts;
+		if (ipc.opt->srr)
+			daddr = icmp_param->replyopts.faddr;
+	}
+	{
+		struct flowi fl = { .nl_u = { .ip4_u =
+					      { .daddr = daddr,
+						.saddr = rt->rt_spec_dst,
+						.tos = RT_TOS(ip_hdr(skb)->tos) } },
+				    .proto = IPPROTO_ICMP };
+		security_skb_classify_flow(skb, &fl);
+		if (ip_route_output_key(net, &rt, &fl))
+			goto out_unlock;
+	}
+	if (icmpv4_xrlim_allow(net, rt, icmp_param->data.icmph.type,
+			       icmp_param->data.icmph.code))
+		icmp_push_reply(icmp_param, &ipc, rt);
+	ip_rt_put(rt);
+out_unlock:
+	icmp_xmit_unlock(sk);
+}
+
+
+/*
+ *	Send an ICMP message in response to a situation
+ *
+ *	RFC 1122: 3.2.2	MUST send at least the IP header and 8 bytes of header.
+ *		  MAY send more (we do).
+ *			MUST NOT change this header information.
+ *			MUST NOT reply to a multicast/broadcast IP address.
+ *			MUST NOT reply to a multicast/broadcast MAC address.
+ *			MUST reply to only the first fragment.
+ */
+
+void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
+{
+	struct iphdr *iph;
+	int room;
+	struct icmp_bxm icmp_param;
+	struct rtable *rt = skb_in->rtable;
+	struct ipcm_cookie ipc;
+	__be32 saddr;
+	u8  tos;
+	struct net *net;
+	struct sock *sk;
+
+	if (!rt)
+		goto out;
+	net = dev_net(rt->u.dst.dev);
+
+	/*
+	 *	Find the original header. It is expected to be valid, of course.
+	 *	Check this, icmp_send is called from the most obscure devices
+	 *	sometimes.
+	 */
+	iph = ip_hdr(skb_in);
+
+	if ((u8 *)iph < skb_in->head ||
+	    (skb_in->network_header + sizeof(*iph)) > skb_in->tail)
+		goto out;
+
+	/*
+	 *	No replies to physical multicast/broadcast
+	 */
+	if (skb_in->pkt_type != PACKET_HOST)
+		goto out;
+
+	/*
+	 *	Now check at the protocol level
+	 */
+	if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
+		goto out;
+
+	/*
+	 *	Only reply to fragment 0. We byte re-order the constant
+	 *	mask for efficiency.
+	 */
+	if (iph->frag_off & htons(IP_OFFSET))
+		goto out;
+
+	/*
+	 *	If we send an ICMP error to an ICMP error a mess would result..
+	 */
+	if (icmp_pointers[type].error) {
+		/*
+		 *	We are an error, check if we are replying to an
+		 *	ICMP error
+		 */
+		if (iph->protocol == IPPROTO_ICMP) {
+			u8 _inner_type, *itp;
+
+			itp = skb_header_pointer(skb_in,
+						 skb_network_header(skb_in) +
+						 (iph->ihl << 2) +
+						 offsetof(struct icmphdr,
+							  type) -
+						 skb_in->data,
+						 sizeof(_inner_type),
+						 &_inner_type);
+			if (itp == NULL)
+				goto out;
+
+			/*
+			 *	Assume any unknown ICMP type is an error. This
+			 *	isn't specified by the RFC, but think about it..
+			 */
+			if (*itp > NR_ICMP_TYPES ||
+			    icmp_pointers[*itp].error)
+				goto out;
+		}
+	}
+
+	sk = icmp_xmit_lock(net);
+	if (sk == NULL)
+		return;
+
+	/*
+	 *	Construct source address and options.
+	 */
+
+	saddr = iph->daddr;
+	if (!(rt->rt_flags & RTCF_LOCAL)) {
+		struct net_device *dev = NULL;
+
+		if (rt->fl.iif &&
+			net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
+			dev = dev_get_by_index(net, rt->fl.iif);
+
+		if (dev) {
+			saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+			dev_put(dev);
+		} else
+			saddr = 0;
+	}
+
+	tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
+					   IPTOS_PREC_INTERNETCONTROL) :
+					  iph->tos;
+
+	if (ip_options_echo(&icmp_param.replyopts, skb_in))
+		goto out_unlock;
+
+
+	/*
+	 *	Prepare data for ICMP header.
+	 */
+
+	icmp_param.data.icmph.type	 = type;
+	icmp_param.data.icmph.code	 = code;
+	icmp_param.data.icmph.un.gateway = info;
+	icmp_param.data.icmph.checksum	 = 0;
+	icmp_param.skb	  = skb_in;
+	icmp_param.offset = skb_network_offset(skb_in);
+	inet_sk(sk)->tos = tos;
+	ipc.addr = iph->saddr;
+	ipc.opt = &icmp_param.replyopts;
+
+	{
+		struct flowi fl = {
+			.nl_u = {
+				.ip4_u = {
+					.daddr = icmp_param.replyopts.srr ?
+						icmp_param.replyopts.faddr :
+						iph->saddr,
+					.saddr = saddr,
+					.tos = RT_TOS(tos)
+				}
+			},
+			.proto = IPPROTO_ICMP,
+			.uli_u = {
+				.icmpt = {
+					.type = type,
+					.code = code
+				}
+			}
+		};
+		int err;
+		struct rtable *rt2;
+
+		security_skb_classify_flow(skb_in, &fl);
+		if (__ip_route_output_key(net, &rt, &fl))
+			goto out_unlock;
+
+		/* No need to clone since we're just using its address. */
+		rt2 = rt;
+
+		err = xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0);
+		switch (err) {
+		case 0:
+			if (rt != rt2)
+				goto route_done;
+			break;
+		case -EPERM:
+			rt = NULL;
+			break;
+		default:
+			goto out_unlock;
+		}
+
+		if (xfrm_decode_session_reverse(skb_in, &fl, AF_INET))
+			goto relookup_failed;
+
+		if (inet_addr_type(net, fl.fl4_src) == RTN_LOCAL)
+			err = __ip_route_output_key(net, &rt2, &fl);
+		else {
+			struct flowi fl2 = {};
+			struct dst_entry *odst;
+
+			fl2.fl4_dst = fl.fl4_src;
+			if (ip_route_output_key(net, &rt2, &fl2))
+				goto relookup_failed;
+
+			/* Ugh! */
+			odst = skb_in->dst;
+			err = ip_route_input(skb_in, fl.fl4_dst, fl.fl4_src,
+					     RT_TOS(tos), rt2->u.dst.dev);
+
+			dst_release(&rt2->u.dst);
+			rt2 = skb_in->rtable;
+			skb_in->dst = odst;
+		}
+
+		if (err)
+			goto relookup_failed;
+
+		err = xfrm_lookup((struct dst_entry **)&rt2, &fl, NULL,
+				  XFRM_LOOKUP_ICMP);
+		switch (err) {
+		case 0:
+			dst_release(&rt->u.dst);
+			rt = rt2;
+			break;
+		case -EPERM:
+			goto ende;
+		default:
+relookup_failed:
+			if (!rt)
+				goto out_unlock;
+			break;
+		}
+	}
+
+route_done:
+	if (!icmpv4_xrlim_allow(net, rt, type, code))
+		goto ende;
+
+	/* RFC says return as much as we can without exceeding 576 bytes. */
+
+	room = dst_mtu(&rt->u.dst);
+	if (room > 576)
+		room = 576;
+	room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
+	room -= sizeof(struct icmphdr);
+
+	icmp_param.data_len = skb_in->len - icmp_param.offset;
+	if (icmp_param.data_len > room)
+		icmp_param.data_len = room;
+	icmp_param.head_len = sizeof(struct icmphdr);
+
+	icmp_push_reply(&icmp_param, &ipc, rt);
+ende:
+	ip_rt_put(rt);
+out_unlock:
+	icmp_xmit_unlock(sk);
+out:;
+}
+
+
+/*
+ *	Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH.
+ */
+
+static void icmp_unreach(struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	struct icmphdr *icmph;
+	int hash, protocol;
+	struct net_protocol *ipprot;
+	u32 info = 0;
+	struct net *net;
+
+	net = dev_net(skb->dst->dev);
+
+	/*
+	 *	Incomplete header ?
+	 * 	Only checks for the IP header, there should be an
+	 *	additional check for longer headers in upper levels.
+	 */
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto out_err;
+
+	icmph = icmp_hdr(skb);
+	iph   = (struct iphdr *)skb->data;
+
+	if (iph->ihl < 5) /* Mangled header, drop. */
+		goto out_err;
+
+	if (icmph->type == ICMP_DEST_UNREACH) {
+		switch (icmph->code & 15) {
+		case ICMP_NET_UNREACH:
+		case ICMP_HOST_UNREACH:
+		case ICMP_PROT_UNREACH:
+		case ICMP_PORT_UNREACH:
+			break;
+		case ICMP_FRAG_NEEDED:
+			if (ipv4_config.no_pmtu_disc) {
+				LIMIT_NETDEBUG(KERN_INFO "ICMP: " NIPQUAD_FMT ": "
+							 "fragmentation needed "
+							 "and DF set.\n",
+					       NIPQUAD(iph->daddr));
+			} else {
+				info = ip_rt_frag_needed(net, iph,
+							 ntohs(icmph->un.frag.mtu),
+							 skb->dev);
+				if (!info)
+					goto out;
+			}
+			break;
+		case ICMP_SR_FAILED:
+			LIMIT_NETDEBUG(KERN_INFO "ICMP: " NIPQUAD_FMT ": Source "
+						 "Route Failed.\n",
+				       NIPQUAD(iph->daddr));
+			break;
+		default:
+			break;
+		}
+		if (icmph->code > NR_ICMP_UNREACH)
+			goto out;
+	} else if (icmph->type == ICMP_PARAMETERPROB)
+		info = ntohl(icmph->un.gateway) >> 24;
+
+	/*
+	 *	Throw it at our lower layers
+	 *
+	 *	RFC 1122: 3.2.2 MUST extract the protocol ID from the passed
+	 *		  header.
+	 *	RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the
+	 *		  transport layer.
+	 *	RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to
+	 *		  transport layer.
+	 */
+
+	/*
+	 *	Check the other end isnt violating RFC 1122. Some routers send
+	 *	bogus responses to broadcast frames. If you see this message
+	 *	first check your netmask matches at both ends, if it does then
+	 *	get the other vendor to fix their kit.
+	 */
+
+	if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses &&
+	    inet_addr_type(net, iph->daddr) == RTN_BROADCAST) {
+		if (net_ratelimit())
+			printk(KERN_WARNING NIPQUAD_FMT " sent an invalid ICMP "
+					    "type %u, code %u "
+					    "error to a broadcast: " NIPQUAD_FMT " on %s\n",
+			       NIPQUAD(ip_hdr(skb)->saddr),
+			       icmph->type, icmph->code,
+			       NIPQUAD(iph->daddr),
+			       skb->dev->name);
+		goto out;
+	}
+
+	/* Checkin full IP header plus 8 bytes of protocol to
+	 * avoid additional coding at protocol handlers.
+	 */
+	if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
+		goto out;
+
+	iph = (struct iphdr *)skb->data;
+	protocol = iph->protocol;
+
+	/*
+	 *	Deliver ICMP message to raw sockets. Pretty useless feature?
+	 */
+	raw_icmp_error(skb, protocol, info);
+
+	hash = protocol & (MAX_INET_PROTOS - 1);
+	rcu_read_lock();
+	ipprot = rcu_dereference(inet_protos[hash]);
+	if (ipprot && ipprot->err_handler)
+		ipprot->err_handler(skb, info);
+	rcu_read_unlock();
+
+out:
+	return;
+out_err:
+	ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
+	goto out;
+}
+
+
+/*
+ *	Handle ICMP_REDIRECT.
+ */
+
+static void icmp_redirect(struct sk_buff *skb)
+{
+	struct iphdr *iph;
+
+	if (skb->len < sizeof(struct iphdr))
+		goto out_err;
+
+	/*
+	 *	Get the copied header of the packet that caused the redirect
+	 */
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto out;
+
+	iph = (struct iphdr *)skb->data;
+
+	switch (icmp_hdr(skb)->code & 7) {
+	case ICMP_REDIR_NET:
+	case ICMP_REDIR_NETTOS:
+		/*
+		 * As per RFC recommendations now handle it as a host redirect.
+		 */
+	case ICMP_REDIR_HOST:
+	case ICMP_REDIR_HOSTTOS:
+		ip_rt_redirect(ip_hdr(skb)->saddr, iph->daddr,
+			       icmp_hdr(skb)->un.gateway,
+			       iph->saddr, skb->dev);
+		break;
+	}
+out:
+	return;
+out_err:
+	ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS);
+	goto out;
+}
+
+/*
+ *	Handle ICMP_ECHO ("ping") requests.
+ *
+ *	RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
+ *		  requests.
+ *	RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be
+ *		  included in the reply.
+ *	RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring
+ *		  echo requests, MUST have default=NOT.
+ *	See also WRT handling of options once they are done and working.
+ */
+
+static void icmp_echo(struct sk_buff *skb)
+{
+	struct net *net;
+
+	net = dev_net(skb->dst->dev);
+	if (!net->ipv4.sysctl_icmp_echo_ignore_all) {
+		struct icmp_bxm icmp_param;
+
+		icmp_param.data.icmph	   = *icmp_hdr(skb);
+		icmp_param.data.icmph.type = ICMP_ECHOREPLY;
+		icmp_param.skb		   = skb;
+		icmp_param.offset	   = 0;
+		icmp_param.data_len	   = skb->len;
+		icmp_param.head_len	   = sizeof(struct icmphdr);
+		icmp_reply(&icmp_param, skb);
+	}
+}
+
+/*
+ *	Handle ICMP Timestamp requests.
+ *	RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests.
+ *		  SHOULD be in the kernel for minimum random latency.
+ *		  MUST be accurate to a few minutes.
+ *		  MUST be updated at least at 15Hz.
+ */
+static void icmp_timestamp(struct sk_buff *skb)
+{
+	struct timespec tv;
+	struct icmp_bxm icmp_param;
+	/*
+	 *	Too short.
+	 */
+	if (skb->len < 4)
+		goto out_err;
+
+	/*
+	 *	Fill in the current time as ms since midnight UT:
+	 */
+	getnstimeofday(&tv);
+	icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC +
+					 tv.tv_nsec / NSEC_PER_MSEC);
+	icmp_param.data.times[2] = icmp_param.data.times[1];
+	if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4))
+		BUG();
+	icmp_param.data.icmph	   = *icmp_hdr(skb);
+	icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY;
+	icmp_param.data.icmph.code = 0;
+	icmp_param.skb		   = skb;
+	icmp_param.offset	   = 0;
+	icmp_param.data_len	   = 0;
+	icmp_param.head_len	   = sizeof(struct icmphdr) + 12;
+	icmp_reply(&icmp_param, skb);
+out:
+	return;
+out_err:
+	ICMP_INC_STATS_BH(dev_net(skb->dst->dev), ICMP_MIB_INERRORS);
+	goto out;
+}
+
+
+/*
+ *	Handle ICMP_ADDRESS_MASK requests.  (RFC950)
+ *
+ * RFC1122 (3.2.2.9).  A host MUST only send replies to
+ * ADDRESS_MASK requests if it's been configured as an address mask
+ * agent.  Receiving a request doesn't constitute implicit permission to
+ * act as one. Of course, implementing this correctly requires (SHOULD)
+ * a way to turn the functionality on and off.  Another one for sysctl(),
+ * I guess. -- MS
+ *
+ * RFC1812 (4.3.3.9).	A router MUST implement it.
+ *			A router SHOULD have switch turning it on/off.
+ *		      	This switch MUST be ON by default.
+ *
+ * Gratuitous replies, zero-source replies are not implemented,
+ * that complies with RFC. DO NOT implement them!!! All the idea
+ * of broadcast addrmask replies as specified in RFC950 is broken.
+ * The problem is that it is not uncommon to have several prefixes
+ * on one physical interface. Moreover, addrmask agent can even be
+ * not aware of existing another prefixes.
+ * If source is zero, addrmask agent cannot choose correct prefix.
+ * Gratuitous mask announcements suffer from the same problem.
+ * RFC1812 explains it, but still allows to use ADDRMASK,
+ * that is pretty silly. --ANK
+ *
+ * All these rules are so bizarre, that I removed kernel addrmask
+ * support at all. It is wrong, it is obsolete, nobody uses it in
+ * any case. --ANK
+ *
+ * Furthermore you can do it with a usermode address agent program
+ * anyway...
+ */
+
+static void icmp_address(struct sk_buff *skb)
+{
+#if 0
+	if (net_ratelimit())
+		printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n");
+#endif
+}
+
+/*
+ * RFC1812 (4.3.3.9).	A router SHOULD listen all replies, and complain
+ *			loudly if an inconsistency is found.
+ */
+
+static void icmp_address_reply(struct sk_buff *skb)
+{
+	struct rtable *rt = skb->rtable;
+	struct net_device *dev = skb->dev;
+	struct in_device *in_dev;
+	struct in_ifaddr *ifa;
+
+	if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC))
+		goto out;
+
+	in_dev = in_dev_get(dev);
+	if (!in_dev)
+		goto out;
+	rcu_read_lock();
+	if (in_dev->ifa_list &&
+	    IN_DEV_LOG_MARTIANS(in_dev) &&
+	    IN_DEV_FORWARD(in_dev)) {
+		__be32 _mask, *mp;
+
+		mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask);
+		BUG_ON(mp == NULL);
+		for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
+			if (*mp == ifa->ifa_mask &&
+			    inet_ifa_match(rt->rt_src, ifa))
+				break;
+		}
+		if (!ifa && net_ratelimit()) {
+			printk(KERN_INFO "Wrong address mask " NIPQUAD_FMT " from "
+					 "%s/" NIPQUAD_FMT "\n",
+			       NIPQUAD(*mp), dev->name, NIPQUAD(rt->rt_src));
+		}
+	}
+	rcu_read_unlock();
+	in_dev_put(in_dev);
+out:;
+}
+
+static void icmp_discard(struct sk_buff *skb)
+{
+}
+
+/*
+ *	Deal with incoming ICMP packets.
+ */
+int icmp_rcv(struct sk_buff *skb)
+{
+	struct icmphdr *icmph;
+	struct rtable *rt = skb->rtable;
+	struct net *net = dev_net(rt->u.dst.dev);
+
+	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+		int nh;
+
+		if (!(skb->sp && skb->sp->xvec[skb->sp->len - 1]->props.flags &
+				 XFRM_STATE_ICMP))
+			goto drop;
+
+		if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr)))
+			goto drop;
+
+		nh = skb_network_offset(skb);
+		skb_set_network_header(skb, sizeof(*icmph));
+
+		if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
+			goto drop;
+
+		skb_set_network_header(skb, nh);
+	}
+
+	ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS);
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (!csum_fold(skb->csum))
+			break;
+		/* fall through */
+	case CHECKSUM_NONE:
+		skb->csum = 0;
+		if (__skb_checksum_complete(skb))
+			goto error;
+	}
+
+	if (!pskb_pull(skb, sizeof(*icmph)))
+		goto error;
+
+	icmph = icmp_hdr(skb);
+
+	ICMPMSGIN_INC_STATS_BH(net, icmph->type);
+	/*
+	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
+	 *
+	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
+	 *		  discarded.
+	 */
+	if (icmph->type > NR_ICMP_TYPES)
+		goto error;
+
+
+	/*
+	 *	Parse the ICMP message
+	 */
+
+	if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
+		/*
+		 *	RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be
+		 *	  silently ignored (we let user decide with a sysctl).
+		 *	RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently
+		 *	  discarded if to broadcast/multicast.
+		 */
+		if ((icmph->type == ICMP_ECHO ||
+		     icmph->type == ICMP_TIMESTAMP) &&
+		    net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {
+			goto error;
+		}
+		if (icmph->type != ICMP_ECHO &&
+		    icmph->type != ICMP_TIMESTAMP &&
+		    icmph->type != ICMP_ADDRESS &&
+		    icmph->type != ICMP_ADDRESSREPLY) {
+			goto error;
+		}
+	}
+
+	icmp_pointers[icmph->type].handler(skb);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+error:
+	ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
+	goto drop;
+}
+
+/*
+ *	This table is the definition of how we handle ICMP.
+ */
+static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
+	[ICMP_ECHOREPLY] = {
+		.handler = icmp_discard,
+	},
+	[1] = {
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[2] = {
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[ICMP_DEST_UNREACH] = {
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_SOURCE_QUENCH] = {
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_REDIRECT] = {
+		.handler = icmp_redirect,
+		.error = 1,
+	},
+	[6] = {
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[7] = {
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[ICMP_ECHO] = {
+		.handler = icmp_echo,
+	},
+	[9] = {
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[10] = {
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[ICMP_TIME_EXCEEDED] = {
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_PARAMETERPROB] = {
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_TIMESTAMP] = {
+		.handler = icmp_timestamp,
+	},
+	[ICMP_TIMESTAMPREPLY] = {
+		.handler = icmp_discard,
+	},
+	[ICMP_INFO_REQUEST] = {
+		.handler = icmp_discard,
+	},
+	[ICMP_INFO_REPLY] = {
+		.handler = icmp_discard,
+	},
+	[ICMP_ADDRESS] = {
+		.handler = icmp_address,
+	},
+	[ICMP_ADDRESSREPLY] = {
+		.handler = icmp_address_reply,
+	},
+};
+
+static void __net_exit icmp_sk_exit(struct net *net)
+{
+	int i;
+
+	for_each_possible_cpu(i)
+		inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]);
+	kfree(net->ipv4.icmp_sk);
+	net->ipv4.icmp_sk = NULL;
+}
+
+static int __net_init icmp_sk_init(struct net *net)
+{
+	int i, err;
+
+	net->ipv4.icmp_sk =
+		kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
+	if (net->ipv4.icmp_sk == NULL)
+		return -ENOMEM;
+
+	for_each_possible_cpu(i) {
+		struct sock *sk;
+
+		err = inet_ctl_sock_create(&sk, PF_INET,
+					   SOCK_RAW, IPPROTO_ICMP, net);
+		if (err < 0)
+			goto fail;
+
+		net->ipv4.icmp_sk[i] = sk;
+
+		/* Enough space for 2 64K ICMP packets, including
+		 * sk_buff struct overhead.
+		 */
+		sk->sk_sndbuf =
+			(2 * ((64 * 1024) + sizeof(struct sk_buff)));
+
+		inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT;
+	}
+
+	/* Control parameters for ECHO replies. */
+	net->ipv4.sysctl_icmp_echo_ignore_all = 0;
+	net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1;
+
+	/* Control parameter - ignore bogus broadcast responses? */
+	net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1;
+
+	/*
+	 * 	Configurable global rate limit.
+	 *
+	 *	ratelimit defines tokens/packet consumed for dst->rate_token
+	 *	bucket ratemask defines which icmp types are ratelimited by
+	 *	setting	it's bit position.
+	 *
+	 *	default:
+	 *	dest unreachable (3), source quench (4),
+	 *	time exceeded (11), parameter problem (12)
+	 */
+
+	net->ipv4.sysctl_icmp_ratelimit = 1 * HZ;
+	net->ipv4.sysctl_icmp_ratemask = 0x1818;
+	net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0;
+
+	return 0;
+
+fail:
+	for_each_possible_cpu(i)
+		inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]);
+	kfree(net->ipv4.icmp_sk);
+	return err;
+}
+
+static struct pernet_operations __net_initdata icmp_sk_ops = {
+       .init = icmp_sk_init,
+       .exit = icmp_sk_exit,
+};
+
+int __init icmp_init(void)
+{
+	return register_pernet_device(&icmp_sk_ops);
+}
+
+EXPORT_SYMBOL(icmp_err_convert);
+EXPORT_SYMBOL(icmp_send);
+EXPORT_SYMBOL(xrlim_allow);
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
new file mode 100644
index 0000000..a0d8645
--- /dev/null
+++ b/net/ipv4/igmp.c
@@ -0,0 +1,2593 @@
+/*
+ *	Linux NET3:	Internet Group Management Protocol  [IGMP]
+ *
+ *	This code implements the IGMP protocol as defined in RFC1112. There has
+ *	been a further revision of this protocol since which is now supported.
+ *
+ *	If you have trouble with this module be careful what gcc you have used,
+ *	the older version didn't come out right using gcc 2.5.8, the newer one
+ *	seems to fall out with gcc 2.6.2.
+ *
+ *	Authors:
+ *		Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	Fixes:
+ *
+ *		Alan Cox	:	Added lots of __inline__ to optimise
+ *					the memory usage of all the tiny little
+ *					functions.
+ *		Alan Cox	:	Dumped the header building experiment.
+ *		Alan Cox	:	Minor tweaks ready for multicast routing
+ *					and extended IGMP protocol.
+ *		Alan Cox	:	Removed a load of inline directives. Gcc 2.5.8
+ *					writes utterly bogus code otherwise (sigh)
+ *					fixed IGMP loopback to behave in the manner
+ *					desired by mrouted, fixed the fact it has been
+ *					broken since 1.3.6 and cleaned up a few minor
+ *					points.
+ *
+ *		Chih-Jen Chang	:	Tried to revise IGMP to Version 2
+ *		Tsu-Sheng Tsao		E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
+ *					The enhancements are mainly based on Steve Deering's
+ * 					ipmulti-3.5 source code.
+ *		Chih-Jen Chang	:	Added the igmp_get_mrouter_info and
+ *		Tsu-Sheng Tsao		igmp_set_mrouter_info to keep track of
+ *					the mrouted version on that device.
+ *		Chih-Jen Chang	:	Added the max_resp_time parameter to
+ *		Tsu-Sheng Tsao		igmp_heard_query(). Using this parameter
+ *					to identify the multicast router version
+ *					and do what the IGMP version 2 specified.
+ *		Chih-Jen Chang	:	Added a timer to revert to IGMP V2 router
+ *		Tsu-Sheng Tsao		if the specified time expired.
+ *		Alan Cox	:	Stop IGMP from 0.0.0.0 being accepted.
+ *		Alan Cox	:	Use GFP_ATOMIC in the right places.
+ *		Christian Daudt :	igmp timer wasn't set for local group
+ *					memberships but was being deleted,
+ *					which caused a "del_timer() called
+ *					from %p with timer not initialized\n"
+ *					message (960131).
+ *		Christian Daudt :	removed del_timer from
+ *					igmp_timer_expire function (960205).
+ *             Christian Daudt :       igmp_heard_report now only calls
+ *                                     igmp_timer_expire if tm->running is
+ *                                     true (960216).
+ *		Malcolm Beattie :	ttl comparison wrong in igmp_rcv made
+ *					igmp_heard_query never trigger. Expiry
+ *					miscalculation fixed in igmp_heard_query
+ *					and random() made to return unsigned to
+ *					prevent negative expiry times.
+ *		Alexey Kuznetsov:	Wrong group leaving behaviour, backport
+ *					fix from pending 2.1.x patches.
+ *		Alan Cox:		Forget to enable FDDI support earlier.
+ *		Alexey Kuznetsov:	Fixed leaving groups on device down.
+ *		Alexey Kuznetsov:	Accordance to igmp-v2-06 draft.
+ *		David L Stevens:	IGMPv3 support, with help from
+ *					Vinay Kulkarni
+ */
+
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/if_arp.h>
+#include <linux/rtnetlink.h>
+#include <linux/times.h>
+
+#include <net/net_namespace.h>
+#include <net/arp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#ifdef CONFIG_IP_MROUTE
+#include <linux/mroute.h>
+#endif
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#endif
+
+#define IP_MAX_MEMBERSHIPS	20
+#define IP_MAX_MSF		10
+
+#ifdef CONFIG_IP_MULTICAST
+/* Parameter names and values are taken from igmp-v2-06 draft */
+
+#define IGMP_V1_Router_Present_Timeout		(400*HZ)
+#define IGMP_V2_Router_Present_Timeout		(400*HZ)
+#define IGMP_Unsolicited_Report_Interval	(10*HZ)
+#define IGMP_Query_Response_Interval		(10*HZ)
+#define IGMP_Unsolicited_Report_Count		2
+
+
+#define IGMP_Initial_Report_Delay		(1)
+
+/* IGMP_Initial_Report_Delay is not from IGMP specs!
+ * IGMP specs require to report membership immediately after
+ * joining a group, but we delay the first report by a
+ * small interval. It seems more natural and still does not
+ * contradict to specs provided this delay is small enough.
+ */
+
+#define IGMP_V1_SEEN(in_dev) \
+	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
+	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
+	 ((in_dev)->mr_v1_seen && \
+	  time_before(jiffies, (in_dev)->mr_v1_seen)))
+#define IGMP_V2_SEEN(in_dev) \
+	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
+	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
+	 ((in_dev)->mr_v2_seen && \
+	  time_before(jiffies, (in_dev)->mr_v2_seen)))
+
+static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
+static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
+static void igmpv3_clear_delrec(struct in_device *in_dev);
+static int sf_setstate(struct ip_mc_list *pmc);
+static void sf_markstate(struct ip_mc_list *pmc);
+#endif
+static void ip_mc_clear_src(struct ip_mc_list *pmc);
+static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
+			 int sfcount, __be32 *psfsrc, int delta);
+
+static void ip_ma_put(struct ip_mc_list *im)
+{
+	if (atomic_dec_and_test(&im->refcnt)) {
+		in_dev_put(im->interface);
+		kfree(im);
+	}
+}
+
+#ifdef CONFIG_IP_MULTICAST
+
+/*
+ *	Timer management
+ */
+
+static __inline__ void igmp_stop_timer(struct ip_mc_list *im)
+{
+	spin_lock_bh(&im->lock);
+	if (del_timer(&im->timer))
+		atomic_dec(&im->refcnt);
+	im->tm_running=0;
+	im->reporter = 0;
+	im->unsolicit_count = 0;
+	spin_unlock_bh(&im->lock);
+}
+
+/* It must be called with locked im->lock */
+static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
+{
+	int tv=net_random() % max_delay;
+
+	im->tm_running=1;
+	if (!mod_timer(&im->timer, jiffies+tv+2))
+		atomic_inc(&im->refcnt);
+}
+
+static void igmp_gq_start_timer(struct in_device *in_dev)
+{
+	int tv = net_random() % in_dev->mr_maxdelay;
+
+	in_dev->mr_gq_running = 1;
+	if (!mod_timer(&in_dev->mr_gq_timer, jiffies+tv+2))
+		in_dev_hold(in_dev);
+}
+
+static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
+{
+	int tv = net_random() % delay;
+
+	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
+		in_dev_hold(in_dev);
+}
+
+static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
+{
+	spin_lock_bh(&im->lock);
+	im->unsolicit_count = 0;
+	if (del_timer(&im->timer)) {
+		if ((long)(im->timer.expires-jiffies) < max_delay) {
+			add_timer(&im->timer);
+			im->tm_running=1;
+			spin_unlock_bh(&im->lock);
+			return;
+		}
+		atomic_dec(&im->refcnt);
+	}
+	igmp_start_timer(im, max_delay);
+	spin_unlock_bh(&im->lock);
+}
+
+
+/*
+ *	Send an IGMP report.
+ */
+
+#define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
+
+
+static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
+	int gdeleted, int sdeleted)
+{
+	switch (type) {
+	case IGMPV3_MODE_IS_INCLUDE:
+	case IGMPV3_MODE_IS_EXCLUDE:
+		if (gdeleted || sdeleted)
+			return 0;
+		if (!(pmc->gsquery && !psf->sf_gsresp)) {
+			if (pmc->sfmode == MCAST_INCLUDE)
+				return 1;
+			/* don't include if this source is excluded
+			 * in all filters
+			 */
+			if (psf->sf_count[MCAST_INCLUDE])
+				return type == IGMPV3_MODE_IS_INCLUDE;
+			return pmc->sfcount[MCAST_EXCLUDE] ==
+				psf->sf_count[MCAST_EXCLUDE];
+		}
+		return 0;
+	case IGMPV3_CHANGE_TO_INCLUDE:
+		if (gdeleted || sdeleted)
+			return 0;
+		return psf->sf_count[MCAST_INCLUDE] != 0;
+	case IGMPV3_CHANGE_TO_EXCLUDE:
+		if (gdeleted || sdeleted)
+			return 0;
+		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
+		    psf->sf_count[MCAST_INCLUDE])
+			return 0;
+		return pmc->sfcount[MCAST_EXCLUDE] ==
+			psf->sf_count[MCAST_EXCLUDE];
+	case IGMPV3_ALLOW_NEW_SOURCES:
+		if (gdeleted || !psf->sf_crcount)
+			return 0;
+		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
+	case IGMPV3_BLOCK_OLD_SOURCES:
+		if (pmc->sfmode == MCAST_INCLUDE)
+			return gdeleted || (psf->sf_crcount && sdeleted);
+		return psf->sf_crcount && !gdeleted && !sdeleted;
+	}
+	return 0;
+}
+
+static int
+igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
+{
+	struct ip_sf_list *psf;
+	int scount = 0;
+
+	for (psf=pmc->sources; psf; psf=psf->sf_next) {
+		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
+			continue;
+		scount++;
+	}
+	return scount;
+}
+
+static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
+{
+	struct sk_buff *skb;
+	struct rtable *rt;
+	struct iphdr *pip;
+	struct igmpv3_report *pig;
+	struct net *net = dev_net(dev);
+
+	skb = alloc_skb(size + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
+	if (skb == NULL)
+		return NULL;
+
+	{
+		struct flowi fl = { .oif = dev->ifindex,
+				    .nl_u = { .ip4_u = {
+				    .daddr = IGMPV3_ALL_MCR } },
+				    .proto = IPPROTO_IGMP };
+		if (ip_route_output_key(net, &rt, &fl)) {
+			kfree_skb(skb);
+			return NULL;
+		}
+	}
+	if (rt->rt_src == 0) {
+		kfree_skb(skb);
+		ip_rt_put(rt);
+		return NULL;
+	}
+
+	skb->dst = &rt->u.dst;
+	skb->dev = dev;
+
+	skb_reserve(skb, LL_RESERVED_SPACE(dev));
+
+	skb_reset_network_header(skb);
+	pip = ip_hdr(skb);
+	skb_put(skb, sizeof(struct iphdr) + 4);
+
+	pip->version  = 4;
+	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
+	pip->tos      = 0xc0;
+	pip->frag_off = htons(IP_DF);
+	pip->ttl      = 1;
+	pip->daddr    = rt->rt_dst;
+	pip->saddr    = rt->rt_src;
+	pip->protocol = IPPROTO_IGMP;
+	pip->tot_len  = 0;	/* filled in later */
+	ip_select_ident(pip, &rt->u.dst, NULL);
+	((u8*)&pip[1])[0] = IPOPT_RA;
+	((u8*)&pip[1])[1] = 4;
+	((u8*)&pip[1])[2] = 0;
+	((u8*)&pip[1])[3] = 0;
+
+	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
+	skb_put(skb, sizeof(*pig));
+	pig = igmpv3_report_hdr(skb);
+	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
+	pig->resv1 = 0;
+	pig->csum = 0;
+	pig->resv2 = 0;
+	pig->ngrec = 0;
+	return skb;
+}
+
+static int igmpv3_sendpack(struct sk_buff *skb)
+{
+	struct igmphdr *pig = igmp_hdr(skb);
+	const int igmplen = skb->tail - skb->transport_header;
+
+	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
+
+	return ip_local_out(skb);
+}
+
+static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
+{
+	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc,type,gdel,sdel);
+}
+
+static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
+	int type, struct igmpv3_grec **ppgr)
+{
+	struct net_device *dev = pmc->interface->dev;
+	struct igmpv3_report *pih;
+	struct igmpv3_grec *pgr;
+
+	if (!skb)
+		skb = igmpv3_newpack(dev, dev->mtu);
+	if (!skb)
+		return NULL;
+	pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
+	pgr->grec_type = type;
+	pgr->grec_auxwords = 0;
+	pgr->grec_nsrcs = 0;
+	pgr->grec_mca = pmc->multiaddr;
+	pih = igmpv3_report_hdr(skb);
+	pih->ngrec = htons(ntohs(pih->ngrec)+1);
+	*ppgr = pgr;
+	return skb;
+}
+
+#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? (skb)->dev->mtu - (skb)->len : \
+	skb_tailroom(skb)) : 0)
+
+static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
+	int type, int gdeleted, int sdeleted)
+{
+	struct net_device *dev = pmc->interface->dev;
+	struct igmpv3_report *pih;
+	struct igmpv3_grec *pgr = NULL;
+	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
+	int scount, stotal, first, isquery, truncate;
+
+	if (pmc->multiaddr == IGMP_ALL_HOSTS)
+		return skb;
+
+	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
+		  type == IGMPV3_MODE_IS_EXCLUDE;
+	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
+		    type == IGMPV3_CHANGE_TO_EXCLUDE;
+
+	stotal = scount = 0;
+
+	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
+
+	if (!*psf_list)
+		goto empty_source;
+
+	pih = skb ? igmpv3_report_hdr(skb) : NULL;
+
+	/* EX and TO_EX get a fresh packet, if needed */
+	if (truncate) {
+		if (pih && pih->ngrec &&
+		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
+			if (skb)
+				igmpv3_sendpack(skb);
+			skb = igmpv3_newpack(dev, dev->mtu);
+		}
+	}
+	first = 1;
+	psf_prev = NULL;
+	for (psf=*psf_list; psf; psf=psf_next) {
+		__be32 *psrc;
+
+		psf_next = psf->sf_next;
+
+		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
+			psf_prev = psf;
+			continue;
+		}
+
+		/* clear marks on query responses */
+		if (isquery)
+			psf->sf_gsresp = 0;
+
+		if (AVAILABLE(skb) < sizeof(__be32) +
+		    first*sizeof(struct igmpv3_grec)) {
+			if (truncate && !first)
+				break;	 /* truncate these */
+			if (pgr)
+				pgr->grec_nsrcs = htons(scount);
+			if (skb)
+				igmpv3_sendpack(skb);
+			skb = igmpv3_newpack(dev, dev->mtu);
+			first = 1;
+			scount = 0;
+		}
+		if (first) {
+			skb = add_grhead(skb, pmc, type, &pgr);
+			first = 0;
+		}
+		if (!skb)
+			return NULL;
+		psrc = (__be32 *)skb_put(skb, sizeof(__be32));
+		*psrc = psf->sf_inaddr;
+		scount++; stotal++;
+		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
+		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
+			psf->sf_crcount--;
+			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
+				if (psf_prev)
+					psf_prev->sf_next = psf->sf_next;
+				else
+					*psf_list = psf->sf_next;
+				kfree(psf);
+				continue;
+			}
+		}
+		psf_prev = psf;
+	}
+
+empty_source:
+	if (!stotal) {
+		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
+		    type == IGMPV3_BLOCK_OLD_SOURCES)
+			return skb;
+		if (pmc->crcount || isquery) {
+			/* make sure we have room for group header */
+			if (skb && AVAILABLE(skb)<sizeof(struct igmpv3_grec)) {
+				igmpv3_sendpack(skb);
+				skb = NULL; /* add_grhead will get a new one */
+			}
+			skb = add_grhead(skb, pmc, type, &pgr);
+		}
+	}
+	if (pgr)
+		pgr->grec_nsrcs = htons(scount);
+
+	if (isquery)
+		pmc->gsquery = 0;	/* clear query state on report */
+	return skb;
+}
+
+static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
+{
+	struct sk_buff *skb = NULL;
+	int type;
+
+	if (!pmc) {
+		read_lock(&in_dev->mc_list_lock);
+		for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
+			if (pmc->multiaddr == IGMP_ALL_HOSTS)
+				continue;
+			spin_lock_bh(&pmc->lock);
+			if (pmc->sfcount[MCAST_EXCLUDE])
+				type = IGMPV3_MODE_IS_EXCLUDE;
+			else
+				type = IGMPV3_MODE_IS_INCLUDE;
+			skb = add_grec(skb, pmc, type, 0, 0);
+			spin_unlock_bh(&pmc->lock);
+		}
+		read_unlock(&in_dev->mc_list_lock);
+	} else {
+		spin_lock_bh(&pmc->lock);
+		if (pmc->sfcount[MCAST_EXCLUDE])
+			type = IGMPV3_MODE_IS_EXCLUDE;
+		else
+			type = IGMPV3_MODE_IS_INCLUDE;
+		skb = add_grec(skb, pmc, type, 0, 0);
+		spin_unlock_bh(&pmc->lock);
+	}
+	if (!skb)
+		return 0;
+	return igmpv3_sendpack(skb);
+}
+
+/*
+ * remove zero-count source records from a source filter list
+ */
+static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
+{
+	struct ip_sf_list *psf_prev, *psf_next, *psf;
+
+	psf_prev = NULL;
+	for (psf=*ppsf; psf; psf = psf_next) {
+		psf_next = psf->sf_next;
+		if (psf->sf_crcount == 0) {
+			if (psf_prev)
+				psf_prev->sf_next = psf->sf_next;
+			else
+				*ppsf = psf->sf_next;
+			kfree(psf);
+		} else
+			psf_prev = psf;
+	}
+}
+
+static void igmpv3_send_cr(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
+	struct sk_buff *skb = NULL;
+	int type, dtype;
+
+	read_lock(&in_dev->mc_list_lock);
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+
+	/* deleted MCA's */
+	pmc_prev = NULL;
+	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc_next) {
+		pmc_next = pmc->next;
+		if (pmc->sfmode == MCAST_INCLUDE) {
+			type = IGMPV3_BLOCK_OLD_SOURCES;
+			dtype = IGMPV3_BLOCK_OLD_SOURCES;
+			skb = add_grec(skb, pmc, type, 1, 0);
+			skb = add_grec(skb, pmc, dtype, 1, 1);
+		}
+		if (pmc->crcount) {
+			if (pmc->sfmode == MCAST_EXCLUDE) {
+				type = IGMPV3_CHANGE_TO_INCLUDE;
+				skb = add_grec(skb, pmc, type, 1, 0);
+			}
+			pmc->crcount--;
+			if (pmc->crcount == 0) {
+				igmpv3_clear_zeros(&pmc->tomb);
+				igmpv3_clear_zeros(&pmc->sources);
+			}
+		}
+		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
+			if (pmc_prev)
+				pmc_prev->next = pmc_next;
+			else
+				in_dev->mc_tomb = pmc_next;
+			in_dev_put(pmc->interface);
+			kfree(pmc);
+		} else
+			pmc_prev = pmc;
+	}
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+
+	/* change recs */
+	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
+		spin_lock_bh(&pmc->lock);
+		if (pmc->sfcount[MCAST_EXCLUDE]) {
+			type = IGMPV3_BLOCK_OLD_SOURCES;
+			dtype = IGMPV3_ALLOW_NEW_SOURCES;
+		} else {
+			type = IGMPV3_ALLOW_NEW_SOURCES;
+			dtype = IGMPV3_BLOCK_OLD_SOURCES;
+		}
+		skb = add_grec(skb, pmc, type, 0, 0);
+		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
+
+		/* filter mode changes */
+		if (pmc->crcount) {
+			if (pmc->sfmode == MCAST_EXCLUDE)
+				type = IGMPV3_CHANGE_TO_EXCLUDE;
+			else
+				type = IGMPV3_CHANGE_TO_INCLUDE;
+			skb = add_grec(skb, pmc, type, 0, 0);
+			pmc->crcount--;
+		}
+		spin_unlock_bh(&pmc->lock);
+	}
+	read_unlock(&in_dev->mc_list_lock);
+
+	if (!skb)
+		return;
+	(void) igmpv3_sendpack(skb);
+}
+
+static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
+	int type)
+{
+	struct sk_buff *skb;
+	struct iphdr *iph;
+	struct igmphdr *ih;
+	struct rtable *rt;
+	struct net_device *dev = in_dev->dev;
+	struct net *net = dev_net(dev);
+	__be32	group = pmc ? pmc->multiaddr : 0;
+	__be32	dst;
+
+	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
+		return igmpv3_send_report(in_dev, pmc);
+	else if (type == IGMP_HOST_LEAVE_MESSAGE)
+		dst = IGMP_ALL_ROUTER;
+	else
+		dst = group;
+
+	{
+		struct flowi fl = { .oif = dev->ifindex,
+				    .nl_u = { .ip4_u = { .daddr = dst } },
+				    .proto = IPPROTO_IGMP };
+		if (ip_route_output_key(net, &rt, &fl))
+			return -1;
+	}
+	if (rt->rt_src == 0) {
+		ip_rt_put(rt);
+		return -1;
+	}
+
+	skb=alloc_skb(IGMP_SIZE+LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
+	if (skb == NULL) {
+		ip_rt_put(rt);
+		return -1;
+	}
+
+	skb->dst = &rt->u.dst;
+
+	skb_reserve(skb, LL_RESERVED_SPACE(dev));
+
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	skb_put(skb, sizeof(struct iphdr) + 4);
+
+	iph->version  = 4;
+	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
+	iph->tos      = 0xc0;
+	iph->frag_off = htons(IP_DF);
+	iph->ttl      = 1;
+	iph->daddr    = dst;
+	iph->saddr    = rt->rt_src;
+	iph->protocol = IPPROTO_IGMP;
+	ip_select_ident(iph, &rt->u.dst, NULL);
+	((u8*)&iph[1])[0] = IPOPT_RA;
+	((u8*)&iph[1])[1] = 4;
+	((u8*)&iph[1])[2] = 0;
+	((u8*)&iph[1])[3] = 0;
+
+	ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
+	ih->type=type;
+	ih->code=0;
+	ih->csum=0;
+	ih->group=group;
+	ih->csum=ip_compute_csum((void *)ih, sizeof(struct igmphdr));
+
+	return ip_local_out(skb);
+}
+
+static void igmp_gq_timer_expire(unsigned long data)
+{
+	struct in_device *in_dev = (struct in_device *)data;
+
+	in_dev->mr_gq_running = 0;
+	igmpv3_send_report(in_dev, NULL);
+	__in_dev_put(in_dev);
+}
+
+static void igmp_ifc_timer_expire(unsigned long data)
+{
+	struct in_device *in_dev = (struct in_device *)data;
+
+	igmpv3_send_cr(in_dev);
+	if (in_dev->mr_ifc_count) {
+		in_dev->mr_ifc_count--;
+		igmp_ifc_start_timer(in_dev, IGMP_Unsolicited_Report_Interval);
+	}
+	__in_dev_put(in_dev);
+}
+
+static void igmp_ifc_event(struct in_device *in_dev)
+{
+	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
+		return;
+	in_dev->mr_ifc_count = in_dev->mr_qrv ? in_dev->mr_qrv :
+		IGMP_Unsolicited_Report_Count;
+	igmp_ifc_start_timer(in_dev, 1);
+}
+
+
+static void igmp_timer_expire(unsigned long data)
+{
+	struct ip_mc_list *im=(struct ip_mc_list *)data;
+	struct in_device *in_dev = im->interface;
+
+	spin_lock(&im->lock);
+	im->tm_running=0;
+
+	if (im->unsolicit_count) {
+		im->unsolicit_count--;
+		igmp_start_timer(im, IGMP_Unsolicited_Report_Interval);
+	}
+	im->reporter = 1;
+	spin_unlock(&im->lock);
+
+	if (IGMP_V1_SEEN(in_dev))
+		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
+	else if (IGMP_V2_SEEN(in_dev))
+		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
+	else
+		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
+
+	ip_ma_put(im);
+}
+
+/* mark EXCLUDE-mode sources */
+static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
+{
+	struct ip_sf_list *psf;
+	int i, scount;
+
+	scount = 0;
+	for (psf=pmc->sources; psf; psf=psf->sf_next) {
+		if (scount == nsrcs)
+			break;
+		for (i=0; i<nsrcs; i++) {
+			/* skip inactive filters */
+			if (pmc->sfcount[MCAST_INCLUDE] ||
+			    pmc->sfcount[MCAST_EXCLUDE] !=
+			    psf->sf_count[MCAST_EXCLUDE])
+				continue;
+			if (srcs[i] == psf->sf_inaddr) {
+				scount++;
+				break;
+			}
+		}
+	}
+	pmc->gsquery = 0;
+	if (scount == nsrcs)	/* all sources excluded */
+		return 0;
+	return 1;
+}
+
+static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
+{
+	struct ip_sf_list *psf;
+	int i, scount;
+
+	if (pmc->sfmode == MCAST_EXCLUDE)
+		return igmp_xmarksources(pmc, nsrcs, srcs);
+
+	/* mark INCLUDE-mode sources */
+	scount = 0;
+	for (psf=pmc->sources; psf; psf=psf->sf_next) {
+		if (scount == nsrcs)
+			break;
+		for (i=0; i<nsrcs; i++)
+			if (srcs[i] == psf->sf_inaddr) {
+				psf->sf_gsresp = 1;
+				scount++;
+				break;
+			}
+	}
+	if (!scount) {
+		pmc->gsquery = 0;
+		return 0;
+	}
+	pmc->gsquery = 1;
+	return 1;
+}
+
+static void igmp_heard_report(struct in_device *in_dev, __be32 group)
+{
+	struct ip_mc_list *im;
+
+	/* Timers are only set for non-local groups */
+
+	if (group == IGMP_ALL_HOSTS)
+		return;
+
+	read_lock(&in_dev->mc_list_lock);
+	for (im=in_dev->mc_list; im!=NULL; im=im->next) {
+		if (im->multiaddr == group) {
+			igmp_stop_timer(im);
+			break;
+		}
+	}
+	read_unlock(&in_dev->mc_list_lock);
+}
+
+static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
+	int len)
+{
+	struct igmphdr 		*ih = igmp_hdr(skb);
+	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
+	struct ip_mc_list	*im;
+	__be32			group = ih->group;
+	int			max_delay;
+	int			mark = 0;
+
+
+	if (len == 8) {
+		if (ih->code == 0) {
+			/* Alas, old v1 router presents here. */
+
+			max_delay = IGMP_Query_Response_Interval;
+			in_dev->mr_v1_seen = jiffies +
+				IGMP_V1_Router_Present_Timeout;
+			group = 0;
+		} else {
+			/* v2 router present */
+			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
+			in_dev->mr_v2_seen = jiffies +
+				IGMP_V2_Router_Present_Timeout;
+		}
+		/* cancel the interface change timer */
+		in_dev->mr_ifc_count = 0;
+		if (del_timer(&in_dev->mr_ifc_timer))
+			__in_dev_put(in_dev);
+		/* clear deleted report items */
+		igmpv3_clear_delrec(in_dev);
+	} else if (len < 12) {
+		return;	/* ignore bogus packet; freed by caller */
+	} else { /* v3 */
+		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
+			return;
+
+		ih3 = igmpv3_query_hdr(skb);
+		if (ih3->nsrcs) {
+			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
+					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
+				return;
+			ih3 = igmpv3_query_hdr(skb);
+		}
+
+		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
+		if (!max_delay)
+			max_delay = 1;	/* can't mod w/ 0 */
+		in_dev->mr_maxdelay = max_delay;
+		if (ih3->qrv)
+			in_dev->mr_qrv = ih3->qrv;
+		if (!group) { /* general query */
+			if (ih3->nsrcs)
+				return;	/* no sources allowed */
+			igmp_gq_start_timer(in_dev);
+			return;
+		}
+		/* mark sources to include, if group & source-specific */
+		mark = ih3->nsrcs != 0;
+	}
+
+	/*
+	 * - Start the timers in all of our membership records
+	 *   that the query applies to for the interface on
+	 *   which the query arrived excl. those that belong
+	 *   to a "local" group (224.0.0.X)
+	 * - For timers already running check if they need to
+	 *   be reset.
+	 * - Use the igmp->igmp_code field as the maximum
+	 *   delay possible
+	 */
+	read_lock(&in_dev->mc_list_lock);
+	for (im=in_dev->mc_list; im!=NULL; im=im->next) {
+		int changed;
+
+		if (group && group != im->multiaddr)
+			continue;
+		if (im->multiaddr == IGMP_ALL_HOSTS)
+			continue;
+		spin_lock_bh(&im->lock);
+		if (im->tm_running)
+			im->gsquery = im->gsquery && mark;
+		else
+			im->gsquery = mark;
+		changed = !im->gsquery ||
+			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
+		spin_unlock_bh(&im->lock);
+		if (changed)
+			igmp_mod_timer(im, max_delay);
+	}
+	read_unlock(&in_dev->mc_list_lock);
+}
+
+int igmp_rcv(struct sk_buff *skb)
+{
+	/* This basically follows the spec line by line -- see RFC1112 */
+	struct igmphdr *ih;
+	struct in_device *in_dev = in_dev_get(skb->dev);
+	int len = skb->len;
+
+	if (in_dev == NULL)
+		goto drop;
+
+	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
+		goto drop_ref;
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (!csum_fold(skb->csum))
+			break;
+		/* fall through */
+	case CHECKSUM_NONE:
+		skb->csum = 0;
+		if (__skb_checksum_complete(skb))
+			goto drop_ref;
+	}
+
+	ih = igmp_hdr(skb);
+	switch (ih->type) {
+	case IGMP_HOST_MEMBERSHIP_QUERY:
+		igmp_heard_query(in_dev, skb, len);
+		break;
+	case IGMP_HOST_MEMBERSHIP_REPORT:
+	case IGMPV2_HOST_MEMBERSHIP_REPORT:
+	case IGMPV3_HOST_MEMBERSHIP_REPORT:
+		/* Is it our report looped back? */
+		if (skb->rtable->fl.iif == 0)
+			break;
+		/* don't rely on MC router hearing unicast reports */
+		if (skb->pkt_type == PACKET_MULTICAST ||
+		    skb->pkt_type == PACKET_BROADCAST)
+			igmp_heard_report(in_dev, ih->group);
+		break;
+	case IGMP_PIM:
+#ifdef CONFIG_IP_PIMSM_V1
+		in_dev_put(in_dev);
+		return pim_rcv_v1(skb);
+#endif
+	case IGMP_DVMRP:
+	case IGMP_TRACE:
+	case IGMP_HOST_LEAVE_MESSAGE:
+	case IGMP_MTRACE:
+	case IGMP_MTRACE_RESP:
+		break;
+	default:
+		break;
+	}
+
+drop_ref:
+	in_dev_put(in_dev);
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+#endif
+
+
+/*
+ *	Add a filter to a device
+ */
+
+static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
+{
+	char buf[MAX_ADDR_LEN];
+	struct net_device *dev = in_dev->dev;
+
+	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
+	   We will get multicast token leakage, when IFF_MULTICAST
+	   is changed. This check should be done in dev->set_multicast_list
+	   routine. Something sort of:
+	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
+	   --ANK
+	   */
+	if (arp_mc_map(addr, buf, dev, 0) == 0)
+		dev_mc_add(dev,buf,dev->addr_len,0);
+}
+
+/*
+ *	Remove a filter from a device
+ */
+
+static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
+{
+	char buf[MAX_ADDR_LEN];
+	struct net_device *dev = in_dev->dev;
+
+	if (arp_mc_map(addr, buf, dev, 0) == 0)
+		dev_mc_delete(dev,buf,dev->addr_len,0);
+}
+
+#ifdef CONFIG_IP_MULTICAST
+/*
+ * deleted ip_mc_list manipulation
+ */
+static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
+{
+	struct ip_mc_list *pmc;
+
+	/* this is an "ip_mc_list" for convenience; only the fields below
+	 * are actually used. In particular, the refcnt and users are not
+	 * used for management of the delete list. Using the same structure
+	 * for deleted items allows change reports to use common code with
+	 * non-deleted or query-response MCA's.
+	 */
+	pmc = kzalloc(sizeof(*pmc), GFP_KERNEL);
+	if (!pmc)
+		return;
+	spin_lock_bh(&im->lock);
+	pmc->interface = im->interface;
+	in_dev_hold(in_dev);
+	pmc->multiaddr = im->multiaddr;
+	pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
+		IGMP_Unsolicited_Report_Count;
+	pmc->sfmode = im->sfmode;
+	if (pmc->sfmode == MCAST_INCLUDE) {
+		struct ip_sf_list *psf;
+
+		pmc->tomb = im->tomb;
+		pmc->sources = im->sources;
+		im->tomb = im->sources = NULL;
+		for (psf=pmc->sources; psf; psf=psf->sf_next)
+			psf->sf_crcount = pmc->crcount;
+	}
+	spin_unlock_bh(&im->lock);
+
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+	pmc->next = in_dev->mc_tomb;
+	in_dev->mc_tomb = pmc;
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+}
+
+static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
+{
+	struct ip_mc_list *pmc, *pmc_prev;
+	struct ip_sf_list *psf, *psf_next;
+
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+	pmc_prev = NULL;
+	for (pmc=in_dev->mc_tomb; pmc; pmc=pmc->next) {
+		if (pmc->multiaddr == multiaddr)
+			break;
+		pmc_prev = pmc;
+	}
+	if (pmc) {
+		if (pmc_prev)
+			pmc_prev->next = pmc->next;
+		else
+			in_dev->mc_tomb = pmc->next;
+	}
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+	if (pmc) {
+		for (psf=pmc->tomb; psf; psf=psf_next) {
+			psf_next = psf->sf_next;
+			kfree(psf);
+		}
+		in_dev_put(pmc->interface);
+		kfree(pmc);
+	}
+}
+
+static void igmpv3_clear_delrec(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc, *nextpmc;
+
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+	pmc = in_dev->mc_tomb;
+	in_dev->mc_tomb = NULL;
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+
+	for (; pmc; pmc = nextpmc) {
+		nextpmc = pmc->next;
+		ip_mc_clear_src(pmc);
+		in_dev_put(pmc->interface);
+		kfree(pmc);
+	}
+	/* clear dead sources, too */
+	read_lock(&in_dev->mc_list_lock);
+	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
+		struct ip_sf_list *psf, *psf_next;
+
+		spin_lock_bh(&pmc->lock);
+		psf = pmc->tomb;
+		pmc->tomb = NULL;
+		spin_unlock_bh(&pmc->lock);
+		for (; psf; psf=psf_next) {
+			psf_next = psf->sf_next;
+			kfree(psf);
+		}
+	}
+	read_unlock(&in_dev->mc_list_lock);
+}
+#endif
+
+static void igmp_group_dropped(struct ip_mc_list *im)
+{
+	struct in_device *in_dev = im->interface;
+#ifdef CONFIG_IP_MULTICAST
+	int reporter;
+#endif
+
+	if (im->loaded) {
+		im->loaded = 0;
+		ip_mc_filter_del(in_dev, im->multiaddr);
+	}
+
+#ifdef CONFIG_IP_MULTICAST
+	if (im->multiaddr == IGMP_ALL_HOSTS)
+		return;
+
+	reporter = im->reporter;
+	igmp_stop_timer(im);
+
+	if (!in_dev->dead) {
+		if (IGMP_V1_SEEN(in_dev))
+			goto done;
+		if (IGMP_V2_SEEN(in_dev)) {
+			if (reporter)
+				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
+			goto done;
+		}
+		/* IGMPv3 */
+		igmpv3_add_delrec(in_dev, im);
+
+		igmp_ifc_event(in_dev);
+	}
+done:
+#endif
+	ip_mc_clear_src(im);
+}
+
+static void igmp_group_added(struct ip_mc_list *im)
+{
+	struct in_device *in_dev = im->interface;
+
+	if (im->loaded == 0) {
+		im->loaded = 1;
+		ip_mc_filter_add(in_dev, im->multiaddr);
+	}
+
+#ifdef CONFIG_IP_MULTICAST
+	if (im->multiaddr == IGMP_ALL_HOSTS)
+		return;
+
+	if (in_dev->dead)
+		return;
+	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
+		spin_lock_bh(&im->lock);
+		igmp_start_timer(im, IGMP_Initial_Report_Delay);
+		spin_unlock_bh(&im->lock);
+		return;
+	}
+	/* else, v3 */
+
+	im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
+		IGMP_Unsolicited_Report_Count;
+	igmp_ifc_event(in_dev);
+#endif
+}
+
+
+/*
+ *	Multicast list managers
+ */
+
+
+/*
+ *	A socket has joined a multicast group on device dev.
+ */
+
+void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
+{
+	struct ip_mc_list *im;
+
+	ASSERT_RTNL();
+
+	for (im=in_dev->mc_list; im; im=im->next) {
+		if (im->multiaddr == addr) {
+			im->users++;
+			ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
+			goto out;
+		}
+	}
+
+	im = kmalloc(sizeof(*im), GFP_KERNEL);
+	if (!im)
+		goto out;
+
+	im->users=1;
+	im->interface=in_dev;
+	in_dev_hold(in_dev);
+	im->multiaddr=addr;
+	/* initial mode is (EX, empty) */
+	im->sfmode = MCAST_EXCLUDE;
+	im->sfcount[MCAST_INCLUDE] = 0;
+	im->sfcount[MCAST_EXCLUDE] = 1;
+	im->sources = NULL;
+	im->tomb = NULL;
+	im->crcount = 0;
+	atomic_set(&im->refcnt, 1);
+	spin_lock_init(&im->lock);
+#ifdef CONFIG_IP_MULTICAST
+	im->tm_running=0;
+	setup_timer(&im->timer, &igmp_timer_expire, (unsigned long)im);
+	im->unsolicit_count = IGMP_Unsolicited_Report_Count;
+	im->reporter = 0;
+	im->gsquery = 0;
+#endif
+	im->loaded = 0;
+	write_lock_bh(&in_dev->mc_list_lock);
+	im->next=in_dev->mc_list;
+	in_dev->mc_list=im;
+	in_dev->mc_count++;
+	write_unlock_bh(&in_dev->mc_list_lock);
+#ifdef CONFIG_IP_MULTICAST
+	igmpv3_del_delrec(in_dev, im->multiaddr);
+#endif
+	igmp_group_added(im);
+	if (!in_dev->dead)
+		ip_rt_multicast_event(in_dev);
+out:
+	return;
+}
+
+/*
+ *	Resend IGMP JOIN report; used for bonding.
+ */
+void ip_mc_rejoin_group(struct ip_mc_list *im)
+{
+#ifdef CONFIG_IP_MULTICAST
+	struct in_device *in_dev = im->interface;
+
+	if (im->multiaddr == IGMP_ALL_HOSTS)
+		return;
+
+	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
+		igmp_mod_timer(im, IGMP_Initial_Report_Delay);
+		return;
+	}
+	/* else, v3 */
+	im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
+		IGMP_Unsolicited_Report_Count;
+	igmp_ifc_event(in_dev);
+#endif
+}
+
+/*
+ *	A socket has left a multicast group on device dev
+ */
+
+void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
+{
+	struct ip_mc_list *i, **ip;
+
+	ASSERT_RTNL();
+
+	for (ip=&in_dev->mc_list; (i=*ip)!=NULL; ip=&i->next) {
+		if (i->multiaddr==addr) {
+			if (--i->users == 0) {
+				write_lock_bh(&in_dev->mc_list_lock);
+				*ip = i->next;
+				in_dev->mc_count--;
+				write_unlock_bh(&in_dev->mc_list_lock);
+				igmp_group_dropped(i);
+
+				if (!in_dev->dead)
+					ip_rt_multicast_event(in_dev);
+
+				ip_ma_put(i);
+				return;
+			}
+			break;
+		}
+	}
+}
+
+/* Device going down */
+
+void ip_mc_down(struct in_device *in_dev)
+{
+	struct ip_mc_list *i;
+
+	ASSERT_RTNL();
+
+	for (i=in_dev->mc_list; i; i=i->next)
+		igmp_group_dropped(i);
+
+#ifdef CONFIG_IP_MULTICAST
+	in_dev->mr_ifc_count = 0;
+	if (del_timer(&in_dev->mr_ifc_timer))
+		__in_dev_put(in_dev);
+	in_dev->mr_gq_running = 0;
+	if (del_timer(&in_dev->mr_gq_timer))
+		__in_dev_put(in_dev);
+	igmpv3_clear_delrec(in_dev);
+#endif
+
+	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
+}
+
+void ip_mc_init_dev(struct in_device *in_dev)
+{
+	ASSERT_RTNL();
+
+	in_dev->mc_tomb = NULL;
+#ifdef CONFIG_IP_MULTICAST
+	in_dev->mr_gq_running = 0;
+	setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
+			(unsigned long)in_dev);
+	in_dev->mr_ifc_count = 0;
+	in_dev->mc_count     = 0;
+	setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
+			(unsigned long)in_dev);
+	in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;
+#endif
+
+	rwlock_init(&in_dev->mc_list_lock);
+	spin_lock_init(&in_dev->mc_tomb_lock);
+}
+
+/* Device going up */
+
+void ip_mc_up(struct in_device *in_dev)
+{
+	struct ip_mc_list *i;
+
+	ASSERT_RTNL();
+
+	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
+
+	for (i=in_dev->mc_list; i; i=i->next)
+		igmp_group_added(i);
+}
+
+/*
+ *	Device is about to be destroyed: clean up.
+ */
+
+void ip_mc_destroy_dev(struct in_device *in_dev)
+{
+	struct ip_mc_list *i;
+
+	ASSERT_RTNL();
+
+	/* Deactivate timers */
+	ip_mc_down(in_dev);
+
+	write_lock_bh(&in_dev->mc_list_lock);
+	while ((i = in_dev->mc_list) != NULL) {
+		in_dev->mc_list = i->next;
+		in_dev->mc_count--;
+		write_unlock_bh(&in_dev->mc_list_lock);
+		igmp_group_dropped(i);
+		ip_ma_put(i);
+
+		write_lock_bh(&in_dev->mc_list_lock);
+	}
+	write_unlock_bh(&in_dev->mc_list_lock);
+}
+
+static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
+{
+	struct flowi fl = { .nl_u = { .ip4_u =
+				      { .daddr = imr->imr_multiaddr.s_addr } } };
+	struct rtable *rt;
+	struct net_device *dev = NULL;
+	struct in_device *idev = NULL;
+
+	if (imr->imr_ifindex) {
+		idev = inetdev_by_index(net, imr->imr_ifindex);
+		if (idev)
+			__in_dev_put(idev);
+		return idev;
+	}
+	if (imr->imr_address.s_addr) {
+		dev = ip_dev_find(net, imr->imr_address.s_addr);
+		if (!dev)
+			return NULL;
+		dev_put(dev);
+	}
+
+	if (!dev && !ip_route_output_key(net, &rt, &fl)) {
+		dev = rt->u.dst.dev;
+		ip_rt_put(rt);
+	}
+	if (dev) {
+		imr->imr_ifindex = dev->ifindex;
+		idev = __in_dev_get_rtnl(dev);
+	}
+	return idev;
+}
+
+/*
+ *	Join a socket to a group
+ */
+int sysctl_igmp_max_memberships __read_mostly = IP_MAX_MEMBERSHIPS;
+int sysctl_igmp_max_msf __read_mostly = IP_MAX_MSF;
+
+
+static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
+	__be32 *psfsrc)
+{
+	struct ip_sf_list *psf, *psf_prev;
+	int rv = 0;
+
+	psf_prev = NULL;
+	for (psf=pmc->sources; psf; psf=psf->sf_next) {
+		if (psf->sf_inaddr == *psfsrc)
+			break;
+		psf_prev = psf;
+	}
+	if (!psf || psf->sf_count[sfmode] == 0) {
+		/* source filter not found, or count wrong =>  bug */
+		return -ESRCH;
+	}
+	psf->sf_count[sfmode]--;
+	if (psf->sf_count[sfmode] == 0) {
+		ip_rt_multicast_event(pmc->interface);
+	}
+	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
+#ifdef CONFIG_IP_MULTICAST
+		struct in_device *in_dev = pmc->interface;
+#endif
+
+		/* no more filters for this source */
+		if (psf_prev)
+			psf_prev->sf_next = psf->sf_next;
+		else
+			pmc->sources = psf->sf_next;
+#ifdef CONFIG_IP_MULTICAST
+		if (psf->sf_oldin &&
+		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
+			psf->sf_crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
+				IGMP_Unsolicited_Report_Count;
+			psf->sf_next = pmc->tomb;
+			pmc->tomb = psf;
+			rv = 1;
+		} else
+#endif
+			kfree(psf);
+	}
+	return rv;
+}
+
+#ifndef CONFIG_IP_MULTICAST
+#define igmp_ifc_event(x)	do { } while (0)
+#endif
+
+static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
+			 int sfcount, __be32 *psfsrc, int delta)
+{
+	struct ip_mc_list *pmc;
+	int	changerec = 0;
+	int	i, err;
+
+	if (!in_dev)
+		return -ENODEV;
+	read_lock(&in_dev->mc_list_lock);
+	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
+		if (*pmca == pmc->multiaddr)
+			break;
+	}
+	if (!pmc) {
+		/* MCA not found?? bug */
+		read_unlock(&in_dev->mc_list_lock);
+		return -ESRCH;
+	}
+	spin_lock_bh(&pmc->lock);
+	read_unlock(&in_dev->mc_list_lock);
+#ifdef CONFIG_IP_MULTICAST
+	sf_markstate(pmc);
+#endif
+	if (!delta) {
+		err = -EINVAL;
+		if (!pmc->sfcount[sfmode])
+			goto out_unlock;
+		pmc->sfcount[sfmode]--;
+	}
+	err = 0;
+	for (i=0; i<sfcount; i++) {
+		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
+
+		changerec |= rv > 0;
+		if (!err && rv < 0)
+			err = rv;
+	}
+	if (pmc->sfmode == MCAST_EXCLUDE &&
+	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
+	    pmc->sfcount[MCAST_INCLUDE]) {
+#ifdef CONFIG_IP_MULTICAST
+		struct ip_sf_list *psf;
+#endif
+
+		/* filter mode change */
+		pmc->sfmode = MCAST_INCLUDE;
+#ifdef CONFIG_IP_MULTICAST
+		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
+			IGMP_Unsolicited_Report_Count;
+		in_dev->mr_ifc_count = pmc->crcount;
+		for (psf=pmc->sources; psf; psf = psf->sf_next)
+			psf->sf_crcount = 0;
+		igmp_ifc_event(pmc->interface);
+	} else if (sf_setstate(pmc) || changerec) {
+		igmp_ifc_event(pmc->interface);
+#endif
+	}
+out_unlock:
+	spin_unlock_bh(&pmc->lock);
+	return err;
+}
+
+/*
+ * Add multicast single-source filter to the interface list
+ */
+static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
+	__be32 *psfsrc, int delta)
+{
+	struct ip_sf_list *psf, *psf_prev;
+
+	psf_prev = NULL;
+	for (psf=pmc->sources; psf; psf=psf->sf_next) {
+		if (psf->sf_inaddr == *psfsrc)
+			break;
+		psf_prev = psf;
+	}
+	if (!psf) {
+		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
+		if (!psf)
+			return -ENOBUFS;
+		psf->sf_inaddr = *psfsrc;
+		if (psf_prev) {
+			psf_prev->sf_next = psf;
+		} else
+			pmc->sources = psf;
+	}
+	psf->sf_count[sfmode]++;
+	if (psf->sf_count[sfmode] == 1) {
+		ip_rt_multicast_event(pmc->interface);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_IP_MULTICAST
+static void sf_markstate(struct ip_mc_list *pmc)
+{
+	struct ip_sf_list *psf;
+	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
+
+	for (psf=pmc->sources; psf; psf=psf->sf_next)
+		if (pmc->sfcount[MCAST_EXCLUDE]) {
+			psf->sf_oldin = mca_xcount ==
+				psf->sf_count[MCAST_EXCLUDE] &&
+				!psf->sf_count[MCAST_INCLUDE];
+		} else
+			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
+}
+
+static int sf_setstate(struct ip_mc_list *pmc)
+{
+	struct ip_sf_list *psf, *dpsf;
+	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
+	int qrv = pmc->interface->mr_qrv;
+	int new_in, rv;
+
+	rv = 0;
+	for (psf=pmc->sources; psf; psf=psf->sf_next) {
+		if (pmc->sfcount[MCAST_EXCLUDE]) {
+			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
+				!psf->sf_count[MCAST_INCLUDE];
+		} else
+			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
+		if (new_in) {
+			if (!psf->sf_oldin) {
+				struct ip_sf_list *prev = NULL;
+
+				for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next) {
+					if (dpsf->sf_inaddr == psf->sf_inaddr)
+						break;
+					prev = dpsf;
+				}
+				if (dpsf) {
+					if (prev)
+						prev->sf_next = dpsf->sf_next;
+					else
+						pmc->tomb = dpsf->sf_next;
+					kfree(dpsf);
+				}
+				psf->sf_crcount = qrv;
+				rv++;
+			}
+		} else if (psf->sf_oldin) {
+
+			psf->sf_crcount = 0;
+			/*
+			 * add or update "delete" records if an active filter
+			 * is now inactive
+			 */
+			for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next)
+				if (dpsf->sf_inaddr == psf->sf_inaddr)
+					break;
+			if (!dpsf) {
+				dpsf = (struct ip_sf_list *)
+					kmalloc(sizeof(*dpsf), GFP_ATOMIC);
+				if (!dpsf)
+					continue;
+				*dpsf = *psf;
+				/* pmc->lock held by callers */
+				dpsf->sf_next = pmc->tomb;
+				pmc->tomb = dpsf;
+			}
+			dpsf->sf_crcount = qrv;
+			rv++;
+		}
+	}
+	return rv;
+}
+#endif
+
+/*
+ * Add multicast source filter list to the interface list
+ */
+static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
+			 int sfcount, __be32 *psfsrc, int delta)
+{
+	struct ip_mc_list *pmc;
+	int	isexclude;
+	int	i, err;
+
+	if (!in_dev)
+		return -ENODEV;
+	read_lock(&in_dev->mc_list_lock);
+	for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
+		if (*pmca == pmc->multiaddr)
+			break;
+	}
+	if (!pmc) {
+		/* MCA not found?? bug */
+		read_unlock(&in_dev->mc_list_lock);
+		return -ESRCH;
+	}
+	spin_lock_bh(&pmc->lock);
+	read_unlock(&in_dev->mc_list_lock);
+
+#ifdef CONFIG_IP_MULTICAST
+	sf_markstate(pmc);
+#endif
+	isexclude = pmc->sfmode == MCAST_EXCLUDE;
+	if (!delta)
+		pmc->sfcount[sfmode]++;
+	err = 0;
+	for (i=0; i<sfcount; i++) {
+		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i], delta);
+		if (err)
+			break;
+	}
+	if (err) {
+		int j;
+
+		pmc->sfcount[sfmode]--;
+		for (j=0; j<i; j++)
+			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
+	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
+#ifdef CONFIG_IP_MULTICAST
+		struct ip_sf_list *psf;
+		in_dev = pmc->interface;
+#endif
+
+		/* filter mode change */
+		if (pmc->sfcount[MCAST_EXCLUDE])
+			pmc->sfmode = MCAST_EXCLUDE;
+		else if (pmc->sfcount[MCAST_INCLUDE])
+			pmc->sfmode = MCAST_INCLUDE;
+#ifdef CONFIG_IP_MULTICAST
+		/* else no filters; keep old mode for reports */
+
+		pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
+			IGMP_Unsolicited_Report_Count;
+		in_dev->mr_ifc_count = pmc->crcount;
+		for (psf=pmc->sources; psf; psf = psf->sf_next)
+			psf->sf_crcount = 0;
+		igmp_ifc_event(in_dev);
+	} else if (sf_setstate(pmc)) {
+		igmp_ifc_event(in_dev);
+#endif
+	}
+	spin_unlock_bh(&pmc->lock);
+	return err;
+}
+
+static void ip_mc_clear_src(struct ip_mc_list *pmc)
+{
+	struct ip_sf_list *psf, *nextpsf;
+
+	for (psf=pmc->tomb; psf; psf=nextpsf) {
+		nextpsf = psf->sf_next;
+		kfree(psf);
+	}
+	pmc->tomb = NULL;
+	for (psf=pmc->sources; psf; psf=nextpsf) {
+		nextpsf = psf->sf_next;
+		kfree(psf);
+	}
+	pmc->sources = NULL;
+	pmc->sfmode = MCAST_EXCLUDE;
+	pmc->sfcount[MCAST_INCLUDE] = 0;
+	pmc->sfcount[MCAST_EXCLUDE] = 1;
+}
+
+
+/*
+ * Join a multicast group
+ */
+int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
+{
+	int err;
+	__be32 addr = imr->imr_multiaddr.s_addr;
+	struct ip_mc_socklist *iml=NULL, *i;
+	struct in_device *in_dev;
+	struct inet_sock *inet = inet_sk(sk);
+	struct net *net = sock_net(sk);
+	int ifindex;
+	int count = 0;
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	rtnl_lock();
+
+	in_dev = ip_mc_find_dev(net, imr);
+
+	if (!in_dev) {
+		iml = NULL;
+		err = -ENODEV;
+		goto done;
+	}
+
+	err = -EADDRINUSE;
+	ifindex = imr->imr_ifindex;
+	for (i = inet->mc_list; i; i = i->next) {
+		if (i->multi.imr_multiaddr.s_addr == addr &&
+		    i->multi.imr_ifindex == ifindex)
+			goto done;
+		count++;
+	}
+	err = -ENOBUFS;
+	if (count >= sysctl_igmp_max_memberships)
+		goto done;
+	iml = sock_kmalloc(sk,sizeof(*iml),GFP_KERNEL);
+	if (iml == NULL)
+		goto done;
+
+	memcpy(&iml->multi, imr, sizeof(*imr));
+	iml->next = inet->mc_list;
+	iml->sflist = NULL;
+	iml->sfmode = MCAST_EXCLUDE;
+	inet->mc_list = iml;
+	ip_mc_inc_group(in_dev, addr);
+	err = 0;
+done:
+	rtnl_unlock();
+	return err;
+}
+
+static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
+			   struct in_device *in_dev)
+{
+	int err;
+
+	if (iml->sflist == NULL) {
+		/* any-source empty exclude case */
+		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
+			iml->sfmode, 0, NULL, 0);
+	}
+	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
+			iml->sfmode, iml->sflist->sl_count,
+			iml->sflist->sl_addr, 0);
+	sock_kfree_s(sk, iml->sflist, IP_SFLSIZE(iml->sflist->sl_max));
+	iml->sflist = NULL;
+	return err;
+}
+
+/*
+ *	Ask a socket to leave a group.
+ */
+
+int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_mc_socklist *iml, **imlp;
+	struct in_device *in_dev;
+	struct net *net = sock_net(sk);
+	__be32 group = imr->imr_multiaddr.s_addr;
+	u32 ifindex;
+	int ret = -EADDRNOTAVAIL;
+
+	rtnl_lock();
+	in_dev = ip_mc_find_dev(net, imr);
+	ifindex = imr->imr_ifindex;
+	for (imlp = &inet->mc_list; (iml = *imlp) != NULL; imlp = &iml->next) {
+		if (iml->multi.imr_multiaddr.s_addr != group)
+			continue;
+		if (ifindex) {
+			if (iml->multi.imr_ifindex != ifindex)
+				continue;
+		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
+				iml->multi.imr_address.s_addr)
+			continue;
+
+		(void) ip_mc_leave_src(sk, iml, in_dev);
+
+		*imlp = iml->next;
+
+		if (in_dev)
+			ip_mc_dec_group(in_dev, group);
+		rtnl_unlock();
+		sock_kfree_s(sk, iml, sizeof(*iml));
+		return 0;
+	}
+	if (!in_dev)
+		ret = -ENODEV;
+	rtnl_unlock();
+	return ret;
+}
+
+int ip_mc_source(int add, int omode, struct sock *sk, struct
+	ip_mreq_source *mreqs, int ifindex)
+{
+	int err;
+	struct ip_mreqn imr;
+	__be32 addr = mreqs->imr_multiaddr;
+	struct ip_mc_socklist *pmc;
+	struct in_device *in_dev = NULL;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *psl;
+	struct net *net = sock_net(sk);
+	int leavegroup = 0;
+	int i, j, rv;
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	rtnl_lock();
+
+	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
+	imr.imr_address.s_addr = mreqs->imr_interface;
+	imr.imr_ifindex = ifindex;
+	in_dev = ip_mc_find_dev(net, &imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+	err = -EADDRNOTAVAIL;
+
+	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
+		if (pmc->multi.imr_multiaddr.s_addr == imr.imr_multiaddr.s_addr
+		    && pmc->multi.imr_ifindex == imr.imr_ifindex)
+			break;
+	}
+	if (!pmc) {		/* must have a prior join */
+		err = -EINVAL;
+		goto done;
+	}
+	/* if a source filter was set, must be the same mode as before */
+	if (pmc->sflist) {
+		if (pmc->sfmode != omode) {
+			err = -EINVAL;
+			goto done;
+		}
+	} else if (pmc->sfmode != omode) {
+		/* allow mode switches for empty-set filters */
+		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
+		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
+			NULL, 0);
+		pmc->sfmode = omode;
+	}
+
+	psl = pmc->sflist;
+	if (!add) {
+		if (!psl)
+			goto done;	/* err = -EADDRNOTAVAIL */
+		rv = !0;
+		for (i=0; i<psl->sl_count; i++) {
+			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
+				sizeof(__be32));
+			if (rv == 0)
+				break;
+		}
+		if (rv)		/* source not found */
+			goto done;	/* err = -EADDRNOTAVAIL */
+
+		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
+		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
+			leavegroup = 1;
+			goto done;
+		}
+
+		/* update the interface filter */
+		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
+			&mreqs->imr_sourceaddr, 1);
+
+		for (j=i+1; j<psl->sl_count; j++)
+			psl->sl_addr[j-1] = psl->sl_addr[j];
+		psl->sl_count--;
+		err = 0;
+		goto done;
+	}
+	/* else, add a new source to the filter */
+
+	if (psl && psl->sl_count >= sysctl_igmp_max_msf) {
+		err = -ENOBUFS;
+		goto done;
+	}
+	if (!psl || psl->sl_count == psl->sl_max) {
+		struct ip_sf_socklist *newpsl;
+		int count = IP_SFBLOCK;
+
+		if (psl)
+			count += psl->sl_max;
+		newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
+		if (!newpsl) {
+			err = -ENOBUFS;
+			goto done;
+		}
+		newpsl->sl_max = count;
+		newpsl->sl_count = count - IP_SFBLOCK;
+		if (psl) {
+			for (i=0; i<psl->sl_count; i++)
+				newpsl->sl_addr[i] = psl->sl_addr[i];
+			sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
+		}
+		pmc->sflist = psl = newpsl;
+	}
+	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
+	for (i=0; i<psl->sl_count; i++) {
+		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
+			sizeof(__be32));
+		if (rv == 0)
+			break;
+	}
+	if (rv == 0)		/* address already there is an error */
+		goto done;
+	for (j=psl->sl_count-1; j>=i; j--)
+		psl->sl_addr[j+1] = psl->sl_addr[j];
+	psl->sl_addr[i] = mreqs->imr_sourceaddr;
+	psl->sl_count++;
+	err = 0;
+	/* update the interface list */
+	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
+		&mreqs->imr_sourceaddr, 1);
+done:
+	rtnl_unlock();
+	if (leavegroup)
+		return ip_mc_leave_group(sk, &imr);
+	return err;
+}
+
+int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
+{
+	int err = 0;
+	struct ip_mreqn	imr;
+	__be32 addr = msf->imsf_multiaddr;
+	struct ip_mc_socklist *pmc;
+	struct in_device *in_dev;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *newpsl, *psl;
+	struct net *net = sock_net(sk);
+	int leavegroup = 0;
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+	if (msf->imsf_fmode != MCAST_INCLUDE &&
+	    msf->imsf_fmode != MCAST_EXCLUDE)
+		return -EINVAL;
+
+	rtnl_lock();
+
+	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
+	imr.imr_address.s_addr = msf->imsf_interface;
+	imr.imr_ifindex = ifindex;
+	in_dev = ip_mc_find_dev(net, &imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+
+	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
+	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
+		leavegroup = 1;
+		goto done;
+	}
+
+	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
+		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
+		    pmc->multi.imr_ifindex == imr.imr_ifindex)
+			break;
+	}
+	if (!pmc) {		/* must have a prior join */
+		err = -EINVAL;
+		goto done;
+	}
+	if (msf->imsf_numsrc) {
+		newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
+							   GFP_KERNEL);
+		if (!newpsl) {
+			err = -ENOBUFS;
+			goto done;
+		}
+		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
+		memcpy(newpsl->sl_addr, msf->imsf_slist,
+			msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
+		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
+			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
+		if (err) {
+			sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
+			goto done;
+		}
+	} else {
+		newpsl = NULL;
+		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
+				     msf->imsf_fmode, 0, NULL, 0);
+	}
+	psl = pmc->sflist;
+	if (psl) {
+		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
+			psl->sl_count, psl->sl_addr, 0);
+		sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
+	} else
+		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
+			0, NULL, 0);
+	pmc->sflist = newpsl;
+	pmc->sfmode = msf->imsf_fmode;
+	err = 0;
+done:
+	rtnl_unlock();
+	if (leavegroup)
+		err = ip_mc_leave_group(sk, &imr);
+	return err;
+}
+
+int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
+	struct ip_msfilter __user *optval, int __user *optlen)
+{
+	int err, len, count, copycount;
+	struct ip_mreqn	imr;
+	__be32 addr = msf->imsf_multiaddr;
+	struct ip_mc_socklist *pmc;
+	struct in_device *in_dev;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *psl;
+	struct net *net = sock_net(sk);
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	rtnl_lock();
+
+	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
+	imr.imr_address.s_addr = msf->imsf_interface;
+	imr.imr_ifindex = 0;
+	in_dev = ip_mc_find_dev(net, &imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+	err = -EADDRNOTAVAIL;
+
+	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
+		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
+		    pmc->multi.imr_ifindex == imr.imr_ifindex)
+			break;
+	}
+	if (!pmc)		/* must have a prior join */
+		goto done;
+	msf->imsf_fmode = pmc->sfmode;
+	psl = pmc->sflist;
+	rtnl_unlock();
+	if (!psl) {
+		len = 0;
+		count = 0;
+	} else {
+		count = psl->sl_count;
+	}
+	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
+	len = copycount * sizeof(psl->sl_addr[0]);
+	msf->imsf_numsrc = count;
+	if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
+	    copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
+		return -EFAULT;
+	}
+	if (len &&
+	    copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
+		return -EFAULT;
+	return 0;
+done:
+	rtnl_unlock();
+	return err;
+}
+
+int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
+	struct group_filter __user *optval, int __user *optlen)
+{
+	int err, i, count, copycount;
+	struct sockaddr_in *psin;
+	__be32 addr;
+	struct ip_mc_socklist *pmc;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *psl;
+
+	psin = (struct sockaddr_in *)&gsf->gf_group;
+	if (psin->sin_family != AF_INET)
+		return -EINVAL;
+	addr = psin->sin_addr.s_addr;
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	rtnl_lock();
+
+	err = -EADDRNOTAVAIL;
+
+	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
+		if (pmc->multi.imr_multiaddr.s_addr == addr &&
+		    pmc->multi.imr_ifindex == gsf->gf_interface)
+			break;
+	}
+	if (!pmc)		/* must have a prior join */
+		goto done;
+	gsf->gf_fmode = pmc->sfmode;
+	psl = pmc->sflist;
+	rtnl_unlock();
+	count = psl ? psl->sl_count : 0;
+	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
+	gsf->gf_numsrc = count;
+	if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
+	    copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
+		return -EFAULT;
+	}
+	for (i=0; i<copycount; i++) {
+		struct sockaddr_storage ss;
+
+		psin = (struct sockaddr_in *)&ss;
+		memset(&ss, 0, sizeof(ss));
+		psin->sin_family = AF_INET;
+		psin->sin_addr.s_addr = psl->sl_addr[i];
+		if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
+			return -EFAULT;
+	}
+	return 0;
+done:
+	rtnl_unlock();
+	return err;
+}
+
+/*
+ * check if a multicast source filter allows delivery for a given <src,dst,intf>
+ */
+int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_mc_socklist *pmc;
+	struct ip_sf_socklist *psl;
+	int i;
+
+	if (!ipv4_is_multicast(loc_addr))
+		return 1;
+
+	for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
+		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
+		    pmc->multi.imr_ifindex == dif)
+			break;
+	}
+	if (!pmc)
+		return 1;
+	psl = pmc->sflist;
+	if (!psl)
+		return pmc->sfmode == MCAST_EXCLUDE;
+
+	for (i=0; i<psl->sl_count; i++) {
+		if (psl->sl_addr[i] == rmt_addr)
+			break;
+	}
+	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
+		return 0;
+	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
+		return 0;
+	return 1;
+}
+
+/*
+ *	A socket is closing.
+ */
+
+void ip_mc_drop_socket(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_mc_socklist *iml;
+	struct net *net = sock_net(sk);
+
+	if (inet->mc_list == NULL)
+		return;
+
+	rtnl_lock();
+	while ((iml = inet->mc_list) != NULL) {
+		struct in_device *in_dev;
+		inet->mc_list = iml->next;
+
+		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
+		(void) ip_mc_leave_src(sk, iml, in_dev);
+		if (in_dev != NULL) {
+			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
+			in_dev_put(in_dev);
+		}
+		sock_kfree_s(sk, iml, sizeof(*iml));
+	}
+	rtnl_unlock();
+}
+
+int ip_check_mc(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
+{
+	struct ip_mc_list *im;
+	struct ip_sf_list *psf;
+	int rv = 0;
+
+	read_lock(&in_dev->mc_list_lock);
+	for (im=in_dev->mc_list; im; im=im->next) {
+		if (im->multiaddr == mc_addr)
+			break;
+	}
+	if (im && proto == IPPROTO_IGMP) {
+		rv = 1;
+	} else if (im) {
+		if (src_addr) {
+			for (psf=im->sources; psf; psf=psf->sf_next) {
+				if (psf->sf_inaddr == src_addr)
+					break;
+			}
+			if (psf)
+				rv = psf->sf_count[MCAST_INCLUDE] ||
+					psf->sf_count[MCAST_EXCLUDE] !=
+					im->sfcount[MCAST_EXCLUDE];
+			else
+				rv = im->sfcount[MCAST_EXCLUDE] != 0;
+		} else
+			rv = 1; /* unspecified source; tentatively allow */
+	}
+	read_unlock(&in_dev->mc_list_lock);
+	return rv;
+}
+
+#if defined(CONFIG_PROC_FS)
+struct igmp_mc_iter_state {
+	struct net_device *dev;
+	struct in_device *in_dev;
+};
+
+#define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
+
+static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
+{
+	struct ip_mc_list *im = NULL;
+	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+
+	state->in_dev = NULL;
+	for_each_netdev(&init_net, state->dev) {
+		struct in_device *in_dev;
+		in_dev = in_dev_get(state->dev);
+		if (!in_dev)
+			continue;
+		read_lock(&in_dev->mc_list_lock);
+		im = in_dev->mc_list;
+		if (im) {
+			state->in_dev = in_dev;
+			break;
+		}
+		read_unlock(&in_dev->mc_list_lock);
+		in_dev_put(in_dev);
+	}
+	return im;
+}
+
+static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
+{
+	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+	im = im->next;
+	while (!im) {
+		if (likely(state->in_dev != NULL)) {
+			read_unlock(&state->in_dev->mc_list_lock);
+			in_dev_put(state->in_dev);
+		}
+		state->dev = next_net_device(state->dev);
+		if (!state->dev) {
+			state->in_dev = NULL;
+			break;
+		}
+		state->in_dev = in_dev_get(state->dev);
+		if (!state->in_dev)
+			continue;
+		read_lock(&state->in_dev->mc_list_lock);
+		im = state->in_dev->mc_list;
+	}
+	return im;
+}
+
+static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct ip_mc_list *im = igmp_mc_get_first(seq);
+	if (im)
+		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
+			--pos;
+	return pos ? NULL : im;
+}
+
+static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(dev_base_lock)
+{
+	read_lock(&dev_base_lock);
+	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct ip_mc_list *im;
+	if (v == SEQ_START_TOKEN)
+		im = igmp_mc_get_first(seq);
+	else
+		im = igmp_mc_get_next(seq, v);
+	++*pos;
+	return im;
+}
+
+static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
+	__releases(dev_base_lock)
+{
+	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+	if (likely(state->in_dev != NULL)) {
+		read_unlock(&state->in_dev->mc_list_lock);
+		in_dev_put(state->in_dev);
+		state->in_dev = NULL;
+	}
+	state->dev = NULL;
+	read_unlock(&dev_base_lock);
+}
+
+static int igmp_mc_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq,
+			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
+	else {
+		struct ip_mc_list *im = (struct ip_mc_list *)v;
+		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+		char   *querier;
+#ifdef CONFIG_IP_MULTICAST
+		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
+			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
+			  "V3";
+#else
+		querier = "NONE";
+#endif
+
+		if (state->in_dev->mc_list == im) {
+			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
+				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
+		}
+
+		seq_printf(seq,
+			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
+			   im->multiaddr, im->users,
+			   im->tm_running, im->tm_running ?
+			   jiffies_to_clock_t(im->timer.expires-jiffies) : 0,
+			   im->reporter);
+	}
+	return 0;
+}
+
+static const struct seq_operations igmp_mc_seq_ops = {
+	.start	=	igmp_mc_seq_start,
+	.next	=	igmp_mc_seq_next,
+	.stop	=	igmp_mc_seq_stop,
+	.show	=	igmp_mc_seq_show,
+};
+
+static int igmp_mc_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_private(file, &igmp_mc_seq_ops,
+			sizeof(struct igmp_mc_iter_state));
+}
+
+static const struct file_operations igmp_mc_seq_fops = {
+	.owner		=	THIS_MODULE,
+	.open		=	igmp_mc_seq_open,
+	.read		=	seq_read,
+	.llseek		=	seq_lseek,
+	.release	=	seq_release_private,
+};
+
+struct igmp_mcf_iter_state {
+	struct net_device *dev;
+	struct in_device *idev;
+	struct ip_mc_list *im;
+};
+
+#define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
+
+static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
+{
+	struct ip_sf_list *psf = NULL;
+	struct ip_mc_list *im = NULL;
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+
+	state->idev = NULL;
+	state->im = NULL;
+	for_each_netdev(&init_net, state->dev) {
+		struct in_device *idev;
+		idev = in_dev_get(state->dev);
+		if (unlikely(idev == NULL))
+			continue;
+		read_lock(&idev->mc_list_lock);
+		im = idev->mc_list;
+		if (likely(im != NULL)) {
+			spin_lock_bh(&im->lock);
+			psf = im->sources;
+			if (likely(psf != NULL)) {
+				state->im = im;
+				state->idev = idev;
+				break;
+			}
+			spin_unlock_bh(&im->lock);
+		}
+		read_unlock(&idev->mc_list_lock);
+		in_dev_put(idev);
+	}
+	return psf;
+}
+
+static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
+{
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+
+	psf = psf->sf_next;
+	while (!psf) {
+		spin_unlock_bh(&state->im->lock);
+		state->im = state->im->next;
+		while (!state->im) {
+			if (likely(state->idev != NULL)) {
+				read_unlock(&state->idev->mc_list_lock);
+				in_dev_put(state->idev);
+			}
+			state->dev = next_net_device(state->dev);
+			if (!state->dev) {
+				state->idev = NULL;
+				goto out;
+			}
+			state->idev = in_dev_get(state->dev);
+			if (!state->idev)
+				continue;
+			read_lock(&state->idev->mc_list_lock);
+			state->im = state->idev->mc_list;
+		}
+		if (!state->im)
+			break;
+		spin_lock_bh(&state->im->lock);
+		psf = state->im->sources;
+	}
+out:
+	return psf;
+}
+
+static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
+	if (psf)
+		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
+			--pos;
+	return pos ? NULL : psf;
+}
+
+static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	read_lock(&dev_base_lock);
+	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct ip_sf_list *psf;
+	if (v == SEQ_START_TOKEN)
+		psf = igmp_mcf_get_first(seq);
+	else
+		psf = igmp_mcf_get_next(seq, v);
+	++*pos;
+	return psf;
+}
+
+static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
+{
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+	if (likely(state->im != NULL)) {
+		spin_unlock_bh(&state->im->lock);
+		state->im = NULL;
+	}
+	if (likely(state->idev != NULL)) {
+		read_unlock(&state->idev->mc_list_lock);
+		in_dev_put(state->idev);
+		state->idev = NULL;
+	}
+	state->dev = NULL;
+	read_unlock(&dev_base_lock);
+}
+
+static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
+{
+	struct ip_sf_list *psf = (struct ip_sf_list *)v;
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq,
+			   "%3s %6s "
+			   "%10s %10s %6s %6s\n", "Idx",
+			   "Device", "MCA",
+			   "SRC", "INC", "EXC");
+	} else {
+		seq_printf(seq,
+			   "%3d %6.6s 0x%08x "
+			   "0x%08x %6lu %6lu\n",
+			   state->dev->ifindex, state->dev->name,
+			   ntohl(state->im->multiaddr),
+			   ntohl(psf->sf_inaddr),
+			   psf->sf_count[MCAST_INCLUDE],
+			   psf->sf_count[MCAST_EXCLUDE]);
+	}
+	return 0;
+}
+
+static const struct seq_operations igmp_mcf_seq_ops = {
+	.start	=	igmp_mcf_seq_start,
+	.next	=	igmp_mcf_seq_next,
+	.stop	=	igmp_mcf_seq_stop,
+	.show	=	igmp_mcf_seq_show,
+};
+
+static int igmp_mcf_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_private(file, &igmp_mcf_seq_ops,
+			sizeof(struct igmp_mcf_iter_state));
+}
+
+static const struct file_operations igmp_mcf_seq_fops = {
+	.owner		=	THIS_MODULE,
+	.open		=	igmp_mcf_seq_open,
+	.read		=	seq_read,
+	.llseek		=	seq_lseek,
+	.release	=	seq_release_private,
+};
+
+int __init igmp_mc_proc_init(void)
+{
+	proc_net_fops_create(&init_net, "igmp", S_IRUGO, &igmp_mc_seq_fops);
+	proc_net_fops_create(&init_net, "mcfilter", S_IRUGO, &igmp_mcf_seq_fops);
+	return 0;
+}
+#endif
+
+EXPORT_SYMBOL(ip_mc_dec_group);
+EXPORT_SYMBOL(ip_mc_inc_group);
+EXPORT_SYMBOL(ip_mc_join_group);
+EXPORT_SYMBOL(ip_mc_rejoin_group);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
new file mode 100644
index 0000000..bd1278a
--- /dev/null
+++ b/net/ipv4/inet_connection_sock.c
@@ -0,0 +1,700 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Support for INET connection oriented protocols.
+ *
+ * Authors:	See the TCP sources
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or(at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/jhash.h>
+
+#include <net/inet_connection_sock.h>
+#include <net/inet_hashtables.h>
+#include <net/inet_timewait_sock.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/tcp_states.h>
+#include <net/xfrm.h>
+
+#ifdef INET_CSK_DEBUG
+const char inet_csk_timer_bug_msg[] = "inet_csk BUG: unknown timer value\n";
+EXPORT_SYMBOL(inet_csk_timer_bug_msg);
+#endif
+
+/*
+ * This struct holds the first and last local port number.
+ */
+struct local_ports sysctl_local_ports __read_mostly = {
+	.lock = SEQLOCK_UNLOCKED,
+	.range = { 32768, 61000 },
+};
+
+void inet_get_local_port_range(int *low, int *high)
+{
+	unsigned seq;
+	do {
+		seq = read_seqbegin(&sysctl_local_ports.lock);
+
+		*low = sysctl_local_ports.range[0];
+		*high = sysctl_local_ports.range[1];
+	} while (read_seqretry(&sysctl_local_ports.lock, seq));
+}
+EXPORT_SYMBOL(inet_get_local_port_range);
+
+int inet_csk_bind_conflict(const struct sock *sk,
+			   const struct inet_bind_bucket *tb)
+{
+	const __be32 sk_rcv_saddr = inet_rcv_saddr(sk);
+	struct sock *sk2;
+	struct hlist_node *node;
+	int reuse = sk->sk_reuse;
+
+	/*
+	 * Unlike other sk lookup places we do not check
+	 * for sk_net here, since _all_ the socks listed
+	 * in tb->owners list belong to the same net - the
+	 * one this bucket belongs to.
+	 */
+
+	sk_for_each_bound(sk2, node, &tb->owners) {
+		if (sk != sk2 &&
+		    !inet_v6_ipv6only(sk2) &&
+		    (!sk->sk_bound_dev_if ||
+		     !sk2->sk_bound_dev_if ||
+		     sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
+			if (!reuse || !sk2->sk_reuse ||
+			    sk2->sk_state == TCP_LISTEN) {
+				const __be32 sk2_rcv_saddr = inet_rcv_saddr(sk2);
+				if (!sk2_rcv_saddr || !sk_rcv_saddr ||
+				    sk2_rcv_saddr == sk_rcv_saddr)
+					break;
+			}
+		}
+	}
+	return node != NULL;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_bind_conflict);
+
+/* Obtain a reference to a local port for the given sock,
+ * if snum is zero it means select any available local port.
+ */
+int inet_csk_get_port(struct sock *sk, unsigned short snum)
+{
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+	struct inet_bind_hashbucket *head;
+	struct hlist_node *node;
+	struct inet_bind_bucket *tb;
+	int ret;
+	struct net *net = sock_net(sk);
+
+	local_bh_disable();
+	if (!snum) {
+		int remaining, rover, low, high;
+
+		inet_get_local_port_range(&low, &high);
+		remaining = (high - low) + 1;
+		rover = net_random() % remaining + low;
+
+		do {
+			head = &hashinfo->bhash[inet_bhashfn(net, rover,
+					hashinfo->bhash_size)];
+			spin_lock(&head->lock);
+			inet_bind_bucket_for_each(tb, node, &head->chain)
+				if (tb->ib_net == net && tb->port == rover)
+					goto next;
+			break;
+		next:
+			spin_unlock(&head->lock);
+			if (++rover > high)
+				rover = low;
+		} while (--remaining > 0);
+
+		/* Exhausted local port range during search?  It is not
+		 * possible for us to be holding one of the bind hash
+		 * locks if this test triggers, because if 'remaining'
+		 * drops to zero, we broke out of the do/while loop at
+		 * the top level, not from the 'break;' statement.
+		 */
+		ret = 1;
+		if (remaining <= 0)
+			goto fail;
+
+		/* OK, here is the one we will use.  HEAD is
+		 * non-NULL and we hold it's mutex.
+		 */
+		snum = rover;
+	} else {
+		head = &hashinfo->bhash[inet_bhashfn(net, snum,
+				hashinfo->bhash_size)];
+		spin_lock(&head->lock);
+		inet_bind_bucket_for_each(tb, node, &head->chain)
+			if (tb->ib_net == net && tb->port == snum)
+				goto tb_found;
+	}
+	tb = NULL;
+	goto tb_not_found;
+tb_found:
+	if (!hlist_empty(&tb->owners)) {
+		if (tb->fastreuse > 0 &&
+		    sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
+			goto success;
+		} else {
+			ret = 1;
+			if (inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb))
+				goto fail_unlock;
+		}
+	}
+tb_not_found:
+	ret = 1;
+	if (!tb && (tb = inet_bind_bucket_create(hashinfo->bind_bucket_cachep,
+					net, head, snum)) == NULL)
+		goto fail_unlock;
+	if (hlist_empty(&tb->owners)) {
+		if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
+			tb->fastreuse = 1;
+		else
+			tb->fastreuse = 0;
+	} else if (tb->fastreuse &&
+		   (!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
+		tb->fastreuse = 0;
+success:
+	if (!inet_csk(sk)->icsk_bind_hash)
+		inet_bind_hash(sk, tb, snum);
+	WARN_ON(inet_csk(sk)->icsk_bind_hash != tb);
+	ret = 0;
+
+fail_unlock:
+	spin_unlock(&head->lock);
+fail:
+	local_bh_enable();
+	return ret;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_get_port);
+
+/*
+ * Wait for an incoming connection, avoid race conditions. This must be called
+ * with the socket locked.
+ */
+static int inet_csk_wait_for_connect(struct sock *sk, long timeo)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	DEFINE_WAIT(wait);
+	int err;
+
+	/*
+	 * True wake-one mechanism for incoming connections: only
+	 * one process gets woken up, not the 'whole herd'.
+	 * Since we do not 'race & poll' for established sockets
+	 * anymore, the common case will execute the loop only once.
+	 *
+	 * Subtle issue: "add_wait_queue_exclusive()" will be added
+	 * after any current non-exclusive waiters, and we know that
+	 * it will always _stay_ after any new non-exclusive waiters
+	 * because all non-exclusive waiters are added at the
+	 * beginning of the wait-queue. As such, it's ok to "drop"
+	 * our exclusiveness temporarily when we get woken up without
+	 * having to remove and re-insert us on the wait queue.
+	 */
+	for (;;) {
+		prepare_to_wait_exclusive(sk->sk_sleep, &wait,
+					  TASK_INTERRUPTIBLE);
+		release_sock(sk);
+		if (reqsk_queue_empty(&icsk->icsk_accept_queue))
+			timeo = schedule_timeout(timeo);
+		lock_sock(sk);
+		err = 0;
+		if (!reqsk_queue_empty(&icsk->icsk_accept_queue))
+			break;
+		err = -EINVAL;
+		if (sk->sk_state != TCP_LISTEN)
+			break;
+		err = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			break;
+		err = -EAGAIN;
+		if (!timeo)
+			break;
+	}
+	finish_wait(sk->sk_sleep, &wait);
+	return err;
+}
+
+/*
+ * This will accept the next outstanding connection.
+ */
+struct sock *inet_csk_accept(struct sock *sk, int flags, int *err)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct sock *newsk;
+	int error;
+
+	lock_sock(sk);
+
+	/* We need to make sure that this socket is listening,
+	 * and that it has something pending.
+	 */
+	error = -EINVAL;
+	if (sk->sk_state != TCP_LISTEN)
+		goto out_err;
+
+	/* Find already established connection */
+	if (reqsk_queue_empty(&icsk->icsk_accept_queue)) {
+		long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
+
+		/* If this is a non blocking socket don't sleep */
+		error = -EAGAIN;
+		if (!timeo)
+			goto out_err;
+
+		error = inet_csk_wait_for_connect(sk, timeo);
+		if (error)
+			goto out_err;
+	}
+
+	newsk = reqsk_queue_get_child(&icsk->icsk_accept_queue, sk);
+	WARN_ON(newsk->sk_state == TCP_SYN_RECV);
+out:
+	release_sock(sk);
+	return newsk;
+out_err:
+	newsk = NULL;
+	*err = error;
+	goto out;
+}
+
+EXPORT_SYMBOL(inet_csk_accept);
+
+/*
+ * Using different timers for retransmit, delayed acks and probes
+ * We may wish use just one timer maintaining a list of expire jiffies
+ * to optimize.
+ */
+void inet_csk_init_xmit_timers(struct sock *sk,
+			       void (*retransmit_handler)(unsigned long),
+			       void (*delack_handler)(unsigned long),
+			       void (*keepalive_handler)(unsigned long))
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	setup_timer(&icsk->icsk_retransmit_timer, retransmit_handler,
+			(unsigned long)sk);
+	setup_timer(&icsk->icsk_delack_timer, delack_handler,
+			(unsigned long)sk);
+	setup_timer(&sk->sk_timer, keepalive_handler, (unsigned long)sk);
+	icsk->icsk_pending = icsk->icsk_ack.pending = 0;
+}
+
+EXPORT_SYMBOL(inet_csk_init_xmit_timers);
+
+void inet_csk_clear_xmit_timers(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	icsk->icsk_pending = icsk->icsk_ack.pending = icsk->icsk_ack.blocked = 0;
+
+	sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
+	sk_stop_timer(sk, &icsk->icsk_delack_timer);
+	sk_stop_timer(sk, &sk->sk_timer);
+}
+
+EXPORT_SYMBOL(inet_csk_clear_xmit_timers);
+
+void inet_csk_delete_keepalive_timer(struct sock *sk)
+{
+	sk_stop_timer(sk, &sk->sk_timer);
+}
+
+EXPORT_SYMBOL(inet_csk_delete_keepalive_timer);
+
+void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len)
+{
+	sk_reset_timer(sk, &sk->sk_timer, jiffies + len);
+}
+
+EXPORT_SYMBOL(inet_csk_reset_keepalive_timer);
+
+struct dst_entry* inet_csk_route_req(struct sock *sk,
+				     const struct request_sock *req)
+{
+	struct rtable *rt;
+	const struct inet_request_sock *ireq = inet_rsk(req);
+	struct ip_options *opt = inet_rsk(req)->opt;
+	struct flowi fl = { .oif = sk->sk_bound_dev_if,
+			    .nl_u = { .ip4_u =
+				      { .daddr = ((opt && opt->srr) ?
+						  opt->faddr :
+						  ireq->rmt_addr),
+					.saddr = ireq->loc_addr,
+					.tos = RT_CONN_FLAGS(sk) } },
+			    .proto = sk->sk_protocol,
+			    .flags = inet_sk_flowi_flags(sk),
+			    .uli_u = { .ports =
+				       { .sport = inet_sk(sk)->sport,
+					 .dport = ireq->rmt_port } } };
+	struct net *net = sock_net(sk);
+
+	security_req_classify_flow(req, &fl);
+	if (ip_route_output_flow(net, &rt, &fl, sk, 0)) {
+		IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+		return NULL;
+	}
+	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
+		ip_rt_put(rt);
+		IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+		return NULL;
+	}
+	return &rt->u.dst;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_route_req);
+
+static inline u32 inet_synq_hash(const __be32 raddr, const __be16 rport,
+				 const u32 rnd, const u32 synq_hsize)
+{
+	return jhash_2words((__force u32)raddr, (__force u32)rport, rnd) & (synq_hsize - 1);
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+#define AF_INET_FAMILY(fam) ((fam) == AF_INET)
+#else
+#define AF_INET_FAMILY(fam) 1
+#endif
+
+struct request_sock *inet_csk_search_req(const struct sock *sk,
+					 struct request_sock ***prevp,
+					 const __be16 rport, const __be32 raddr,
+					 const __be32 laddr)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
+	struct request_sock *req, **prev;
+
+	for (prev = &lopt->syn_table[inet_synq_hash(raddr, rport, lopt->hash_rnd,
+						    lopt->nr_table_entries)];
+	     (req = *prev) != NULL;
+	     prev = &req->dl_next) {
+		const struct inet_request_sock *ireq = inet_rsk(req);
+
+		if (ireq->rmt_port == rport &&
+		    ireq->rmt_addr == raddr &&
+		    ireq->loc_addr == laddr &&
+		    AF_INET_FAMILY(req->rsk_ops->family)) {
+			WARN_ON(req->sk);
+			*prevp = prev;
+			break;
+		}
+	}
+
+	return req;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_search_req);
+
+void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
+				   unsigned long timeout)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
+	const u32 h = inet_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port,
+				     lopt->hash_rnd, lopt->nr_table_entries);
+
+	reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
+	inet_csk_reqsk_queue_added(sk, timeout);
+}
+
+/* Only thing we need from tcp.h */
+extern int sysctl_tcp_synack_retries;
+
+EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
+
+void inet_csk_reqsk_queue_prune(struct sock *parent,
+				const unsigned long interval,
+				const unsigned long timeout,
+				const unsigned long max_rto)
+{
+	struct inet_connection_sock *icsk = inet_csk(parent);
+	struct request_sock_queue *queue = &icsk->icsk_accept_queue;
+	struct listen_sock *lopt = queue->listen_opt;
+	int max_retries = icsk->icsk_syn_retries ? : sysctl_tcp_synack_retries;
+	int thresh = max_retries;
+	unsigned long now = jiffies;
+	struct request_sock **reqp, *req;
+	int i, budget;
+
+	if (lopt == NULL || lopt->qlen == 0)
+		return;
+
+	/* Normally all the openreqs are young and become mature
+	 * (i.e. converted to established socket) for first timeout.
+	 * If synack was not acknowledged for 3 seconds, it means
+	 * one of the following things: synack was lost, ack was lost,
+	 * rtt is high or nobody planned to ack (i.e. synflood).
+	 * When server is a bit loaded, queue is populated with old
+	 * open requests, reducing effective size of queue.
+	 * When server is well loaded, queue size reduces to zero
+	 * after several minutes of work. It is not synflood,
+	 * it is normal operation. The solution is pruning
+	 * too old entries overriding normal timeout, when
+	 * situation becomes dangerous.
+	 *
+	 * Essentially, we reserve half of room for young
+	 * embrions; and abort old ones without pity, if old
+	 * ones are about to clog our table.
+	 */
+	if (lopt->qlen>>(lopt->max_qlen_log-1)) {
+		int young = (lopt->qlen_young<<1);
+
+		while (thresh > 2) {
+			if (lopt->qlen < young)
+				break;
+			thresh--;
+			young <<= 1;
+		}
+	}
+
+	if (queue->rskq_defer_accept)
+		max_retries = queue->rskq_defer_accept;
+
+	budget = 2 * (lopt->nr_table_entries / (timeout / interval));
+	i = lopt->clock_hand;
+
+	do {
+		reqp=&lopt->syn_table[i];
+		while ((req = *reqp) != NULL) {
+			if (time_after_eq(now, req->expires)) {
+				if ((req->retrans < thresh ||
+				     (inet_rsk(req)->acked && req->retrans < max_retries))
+				    && !req->rsk_ops->rtx_syn_ack(parent, req)) {
+					unsigned long timeo;
+
+					if (req->retrans++ == 0)
+						lopt->qlen_young--;
+					timeo = min((timeout << req->retrans), max_rto);
+					req->expires = now + timeo;
+					reqp = &req->dl_next;
+					continue;
+				}
+
+				/* Drop this request */
+				inet_csk_reqsk_queue_unlink(parent, req, reqp);
+				reqsk_queue_removed(queue, req);
+				reqsk_free(req);
+				continue;
+			}
+			reqp = &req->dl_next;
+		}
+
+		i = (i + 1) & (lopt->nr_table_entries - 1);
+
+	} while (--budget > 0);
+
+	lopt->clock_hand = i;
+
+	if (lopt->qlen)
+		inet_csk_reset_keepalive_timer(parent, interval);
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_prune);
+
+struct sock *inet_csk_clone(struct sock *sk, const struct request_sock *req,
+			    const gfp_t priority)
+{
+	struct sock *newsk = sk_clone(sk, priority);
+
+	if (newsk != NULL) {
+		struct inet_connection_sock *newicsk = inet_csk(newsk);
+
+		newsk->sk_state = TCP_SYN_RECV;
+		newicsk->icsk_bind_hash = NULL;
+
+		inet_sk(newsk)->dport = inet_rsk(req)->rmt_port;
+		inet_sk(newsk)->num = ntohs(inet_rsk(req)->loc_port);
+		inet_sk(newsk)->sport = inet_rsk(req)->loc_port;
+		newsk->sk_write_space = sk_stream_write_space;
+
+		newicsk->icsk_retransmits = 0;
+		newicsk->icsk_backoff	  = 0;
+		newicsk->icsk_probes_out  = 0;
+
+		/* Deinitialize accept_queue to trap illegal accesses. */
+		memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
+
+		security_inet_csk_clone(newsk, req);
+	}
+	return newsk;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_clone);
+
+/*
+ * At this point, there should be no process reference to this
+ * socket, and thus no user references at all.  Therefore we
+ * can assume the socket waitqueue is inactive and nobody will
+ * try to jump onto it.
+ */
+void inet_csk_destroy_sock(struct sock *sk)
+{
+	WARN_ON(sk->sk_state != TCP_CLOSE);
+	WARN_ON(!sock_flag(sk, SOCK_DEAD));
+
+	/* It cannot be in hash table! */
+	WARN_ON(!sk_unhashed(sk));
+
+	/* If it has not 0 inet_sk(sk)->num, it must be bound */
+	WARN_ON(inet_sk(sk)->num && !inet_csk(sk)->icsk_bind_hash);
+
+	sk->sk_prot->destroy(sk);
+
+	sk_stream_kill_queues(sk);
+
+	xfrm_sk_free_policy(sk);
+
+	sk_refcnt_debug_release(sk);
+
+	atomic_dec(sk->sk_prot->orphan_count);
+	sock_put(sk);
+}
+
+EXPORT_SYMBOL(inet_csk_destroy_sock);
+
+int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
+
+	if (rc != 0)
+		return rc;
+
+	sk->sk_max_ack_backlog = 0;
+	sk->sk_ack_backlog = 0;
+	inet_csk_delack_init(sk);
+
+	/* There is race window here: we announce ourselves listening,
+	 * but this transition is still not validated by get_port().
+	 * It is OK, because this socket enters to hash table only
+	 * after validation is complete.
+	 */
+	sk->sk_state = TCP_LISTEN;
+	if (!sk->sk_prot->get_port(sk, inet->num)) {
+		inet->sport = htons(inet->num);
+
+		sk_dst_reset(sk);
+		sk->sk_prot->hash(sk);
+
+		return 0;
+	}
+
+	sk->sk_state = TCP_CLOSE;
+	__reqsk_queue_destroy(&icsk->icsk_accept_queue);
+	return -EADDRINUSE;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_listen_start);
+
+/*
+ *	This routine closes sockets which have been at least partially
+ *	opened, but not yet accepted.
+ */
+void inet_csk_listen_stop(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct request_sock *acc_req;
+	struct request_sock *req;
+
+	inet_csk_delete_keepalive_timer(sk);
+
+	/* make all the listen_opt local to us */
+	acc_req = reqsk_queue_yank_acceptq(&icsk->icsk_accept_queue);
+
+	/* Following specs, it would be better either to send FIN
+	 * (and enter FIN-WAIT-1, it is normal close)
+	 * or to send active reset (abort).
+	 * Certainly, it is pretty dangerous while synflood, but it is
+	 * bad justification for our negligence 8)
+	 * To be honest, we are not able to make either
+	 * of the variants now.			--ANK
+	 */
+	reqsk_queue_destroy(&icsk->icsk_accept_queue);
+
+	while ((req = acc_req) != NULL) {
+		struct sock *child = req->sk;
+
+		acc_req = req->dl_next;
+
+		local_bh_disable();
+		bh_lock_sock(child);
+		WARN_ON(sock_owned_by_user(child));
+		sock_hold(child);
+
+		sk->sk_prot->disconnect(child, O_NONBLOCK);
+
+		sock_orphan(child);
+
+		atomic_inc(sk->sk_prot->orphan_count);
+
+		inet_csk_destroy_sock(child);
+
+		bh_unlock_sock(child);
+		local_bh_enable();
+		sock_put(child);
+
+		sk_acceptq_removed(sk);
+		__reqsk_free(req);
+	}
+	WARN_ON(sk->sk_ack_backlog);
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
+
+void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
+	const struct inet_sock *inet = inet_sk(sk);
+
+	sin->sin_family		= AF_INET;
+	sin->sin_addr.s_addr	= inet->daddr;
+	sin->sin_port		= inet->dport;
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr);
+
+#ifdef CONFIG_COMPAT
+int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
+			       char __user *optval, int __user *optlen)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (icsk->icsk_af_ops->compat_getsockopt != NULL)
+		return icsk->icsk_af_ops->compat_getsockopt(sk, level, optname,
+							    optval, optlen);
+	return icsk->icsk_af_ops->getsockopt(sk, level, optname,
+					     optval, optlen);
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_compat_getsockopt);
+
+int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
+			       char __user *optval, int optlen)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (icsk->icsk_af_ops->compat_setsockopt != NULL)
+		return icsk->icsk_af_ops->compat_setsockopt(sk, level, optname,
+							    optval, optlen);
+	return icsk->icsk_af_ops->setsockopt(sk, level, optname,
+					     optval, optlen);
+}
+
+EXPORT_SYMBOL_GPL(inet_csk_compat_setsockopt);
+#endif
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
new file mode 100644
index 0000000..564230d
--- /dev/null
+++ b/net/ipv4/inet_diag.c
@@ -0,0 +1,946 @@
+/*
+ * inet_diag.c	Module for monitoring INET transport protocols sockets.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/random.h>
+#include <linux/cache.h>
+#include <linux/init.h>
+#include <linux/time.h>
+
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/ipv6.h>
+#include <net/inet_common.h>
+#include <net/inet_connection_sock.h>
+#include <net/inet_hashtables.h>
+#include <net/inet_timewait_sock.h>
+#include <net/inet6_hashtables.h>
+#include <net/netlink.h>
+
+#include <linux/inet.h>
+#include <linux/stddef.h>
+
+#include <linux/inet_diag.h>
+
+static const struct inet_diag_handler **inet_diag_table;
+
+struct inet_diag_entry {
+	__be32 *saddr;
+	__be32 *daddr;
+	u16 sport;
+	u16 dport;
+	u16 family;
+	u16 userlocks;
+};
+
+static struct sock *idiagnl;
+
+#define INET_DIAG_PUT(skb, attrtype, attrlen) \
+	RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
+
+static DEFINE_MUTEX(inet_diag_table_mutex);
+
+static const struct inet_diag_handler *inet_diag_lock_handler(int type)
+{
+	if (!inet_diag_table[type])
+		request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
+			       NETLINK_INET_DIAG, type);
+
+	mutex_lock(&inet_diag_table_mutex);
+	if (!inet_diag_table[type])
+		return ERR_PTR(-ENOENT);
+
+	return inet_diag_table[type];
+}
+
+static inline void inet_diag_unlock_handler(
+	const struct inet_diag_handler *handler)
+{
+	mutex_unlock(&inet_diag_table_mutex);
+}
+
+static int inet_csk_diag_fill(struct sock *sk,
+			      struct sk_buff *skb,
+			      int ext, u32 pid, u32 seq, u16 nlmsg_flags,
+			      const struct nlmsghdr *unlh)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct inet_diag_msg *r;
+	struct nlmsghdr  *nlh;
+	void *info = NULL;
+	struct inet_diag_meminfo  *minfo = NULL;
+	unsigned char	 *b = skb_tail_pointer(skb);
+	const struct inet_diag_handler *handler;
+
+	handler = inet_diag_table[unlh->nlmsg_type];
+	BUG_ON(handler == NULL);
+
+	nlh = NLMSG_PUT(skb, pid, seq, unlh->nlmsg_type, sizeof(*r));
+	nlh->nlmsg_flags = nlmsg_flags;
+
+	r = NLMSG_DATA(nlh);
+	BUG_ON(sk->sk_state == TCP_TIME_WAIT);
+
+	if (ext & (1 << (INET_DIAG_MEMINFO - 1)))
+		minfo = INET_DIAG_PUT(skb, INET_DIAG_MEMINFO, sizeof(*minfo));
+
+	if (ext & (1 << (INET_DIAG_INFO - 1)))
+		info = INET_DIAG_PUT(skb, INET_DIAG_INFO,
+				     handler->idiag_info_size);
+
+	if ((ext & (1 << (INET_DIAG_CONG - 1))) && icsk->icsk_ca_ops) {
+		const size_t len = strlen(icsk->icsk_ca_ops->name);
+
+		strcpy(INET_DIAG_PUT(skb, INET_DIAG_CONG, len + 1),
+		       icsk->icsk_ca_ops->name);
+	}
+
+	r->idiag_family = sk->sk_family;
+	r->idiag_state = sk->sk_state;
+	r->idiag_timer = 0;
+	r->idiag_retrans = 0;
+
+	r->id.idiag_if = sk->sk_bound_dev_if;
+	r->id.idiag_cookie[0] = (u32)(unsigned long)sk;
+	r->id.idiag_cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
+
+	r->id.idiag_sport = inet->sport;
+	r->id.idiag_dport = inet->dport;
+	r->id.idiag_src[0] = inet->rcv_saddr;
+	r->id.idiag_dst[0] = inet->daddr;
+
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+	if (r->idiag_family == AF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_src,
+			       &np->rcv_saddr);
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
+			       &np->daddr);
+	}
+#endif
+
+#define EXPIRES_IN_MS(tmo)  DIV_ROUND_UP((tmo - jiffies) * 1000, HZ)
+
+	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
+		r->idiag_timer = 1;
+		r->idiag_retrans = icsk->icsk_retransmits;
+		r->idiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
+	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
+		r->idiag_timer = 4;
+		r->idiag_retrans = icsk->icsk_probes_out;
+		r->idiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
+	} else if (timer_pending(&sk->sk_timer)) {
+		r->idiag_timer = 2;
+		r->idiag_retrans = icsk->icsk_probes_out;
+		r->idiag_expires = EXPIRES_IN_MS(sk->sk_timer.expires);
+	} else {
+		r->idiag_timer = 0;
+		r->idiag_expires = 0;
+	}
+#undef EXPIRES_IN_MS
+
+	r->idiag_uid = sock_i_uid(sk);
+	r->idiag_inode = sock_i_ino(sk);
+
+	if (minfo) {
+		minfo->idiag_rmem = atomic_read(&sk->sk_rmem_alloc);
+		minfo->idiag_wmem = sk->sk_wmem_queued;
+		minfo->idiag_fmem = sk->sk_forward_alloc;
+		minfo->idiag_tmem = atomic_read(&sk->sk_wmem_alloc);
+	}
+
+	handler->idiag_get_info(sk, r, info);
+
+	if (sk->sk_state < TCP_TIME_WAIT &&
+	    icsk->icsk_ca_ops && icsk->icsk_ca_ops->get_info)
+		icsk->icsk_ca_ops->get_info(sk, ext, skb);
+
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
+	return skb->len;
+
+rtattr_failure:
+nlmsg_failure:
+	nlmsg_trim(skb, b);
+	return -EMSGSIZE;
+}
+
+static int inet_twsk_diag_fill(struct inet_timewait_sock *tw,
+			       struct sk_buff *skb, int ext, u32 pid,
+			       u32 seq, u16 nlmsg_flags,
+			       const struct nlmsghdr *unlh)
+{
+	long tmo;
+	struct inet_diag_msg *r;
+	const unsigned char *previous_tail = skb_tail_pointer(skb);
+	struct nlmsghdr *nlh = NLMSG_PUT(skb, pid, seq,
+					 unlh->nlmsg_type, sizeof(*r));
+
+	r = NLMSG_DATA(nlh);
+	BUG_ON(tw->tw_state != TCP_TIME_WAIT);
+
+	nlh->nlmsg_flags = nlmsg_flags;
+
+	tmo = tw->tw_ttd - jiffies;
+	if (tmo < 0)
+		tmo = 0;
+
+	r->idiag_family	      = tw->tw_family;
+	r->idiag_state	      = tw->tw_state;
+	r->idiag_timer	      = 0;
+	r->idiag_retrans      = 0;
+	r->id.idiag_if	      = tw->tw_bound_dev_if;
+	r->id.idiag_cookie[0] = (u32)(unsigned long)tw;
+	r->id.idiag_cookie[1] = (u32)(((unsigned long)tw >> 31) >> 1);
+	r->id.idiag_sport     = tw->tw_sport;
+	r->id.idiag_dport     = tw->tw_dport;
+	r->id.idiag_src[0]    = tw->tw_rcv_saddr;
+	r->id.idiag_dst[0]    = tw->tw_daddr;
+	r->idiag_state	      = tw->tw_substate;
+	r->idiag_timer	      = 3;
+	r->idiag_expires      = DIV_ROUND_UP(tmo * 1000, HZ);
+	r->idiag_rqueue	      = 0;
+	r->idiag_wqueue	      = 0;
+	r->idiag_uid	      = 0;
+	r->idiag_inode	      = 0;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+	if (tw->tw_family == AF_INET6) {
+		const struct inet6_timewait_sock *tw6 =
+						inet6_twsk((struct sock *)tw);
+
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_src,
+			       &tw6->tw_v6_rcv_saddr);
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
+			       &tw6->tw_v6_daddr);
+	}
+#endif
+	nlh->nlmsg_len = skb_tail_pointer(skb) - previous_tail;
+	return skb->len;
+nlmsg_failure:
+	nlmsg_trim(skb, previous_tail);
+	return -EMSGSIZE;
+}
+
+static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
+			int ext, u32 pid, u32 seq, u16 nlmsg_flags,
+			const struct nlmsghdr *unlh)
+{
+	if (sk->sk_state == TCP_TIME_WAIT)
+		return inet_twsk_diag_fill((struct inet_timewait_sock *)sk,
+					   skb, ext, pid, seq, nlmsg_flags,
+					   unlh);
+	return inet_csk_diag_fill(sk, skb, ext, pid, seq, nlmsg_flags, unlh);
+}
+
+static int inet_diag_get_exact(struct sk_buff *in_skb,
+			       const struct nlmsghdr *nlh)
+{
+	int err;
+	struct sock *sk;
+	struct inet_diag_req *req = NLMSG_DATA(nlh);
+	struct sk_buff *rep;
+	struct inet_hashinfo *hashinfo;
+	const struct inet_diag_handler *handler;
+
+	handler = inet_diag_lock_handler(nlh->nlmsg_type);
+	if (IS_ERR(handler)) {
+		err = PTR_ERR(handler);
+		goto unlock;
+	}
+
+	hashinfo = handler->idiag_hashinfo;
+	err = -EINVAL;
+
+	if (req->idiag_family == AF_INET) {
+		sk = inet_lookup(&init_net, hashinfo, req->id.idiag_dst[0],
+				 req->id.idiag_dport, req->id.idiag_src[0],
+				 req->id.idiag_sport, req->id.idiag_if);
+	}
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+	else if (req->idiag_family == AF_INET6) {
+		sk = inet6_lookup(&init_net, hashinfo,
+				  (struct in6_addr *)req->id.idiag_dst,
+				  req->id.idiag_dport,
+				  (struct in6_addr *)req->id.idiag_src,
+				  req->id.idiag_sport,
+				  req->id.idiag_if);
+	}
+#endif
+	else {
+		goto unlock;
+	}
+
+	err = -ENOENT;
+	if (sk == NULL)
+		goto unlock;
+
+	err = -ESTALE;
+	if ((req->id.idiag_cookie[0] != INET_DIAG_NOCOOKIE ||
+	     req->id.idiag_cookie[1] != INET_DIAG_NOCOOKIE) &&
+	    ((u32)(unsigned long)sk != req->id.idiag_cookie[0] ||
+	     (u32)((((unsigned long)sk) >> 31) >> 1) != req->id.idiag_cookie[1]))
+		goto out;
+
+	err = -ENOMEM;
+	rep = alloc_skb(NLMSG_SPACE((sizeof(struct inet_diag_msg) +
+				     sizeof(struct inet_diag_meminfo) +
+				     handler->idiag_info_size + 64)),
+			GFP_KERNEL);
+	if (!rep)
+		goto out;
+
+	err = sk_diag_fill(sk, rep, req->idiag_ext,
+			   NETLINK_CB(in_skb).pid,
+			   nlh->nlmsg_seq, 0, nlh);
+	if (err < 0) {
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(rep);
+		goto out;
+	}
+	err = netlink_unicast(idiagnl, rep, NETLINK_CB(in_skb).pid,
+			      MSG_DONTWAIT);
+	if (err > 0)
+		err = 0;
+
+out:
+	if (sk) {
+		if (sk->sk_state == TCP_TIME_WAIT)
+			inet_twsk_put((struct inet_timewait_sock *)sk);
+		else
+			sock_put(sk);
+	}
+unlock:
+	inet_diag_unlock_handler(handler);
+	return err;
+}
+
+static int bitstring_match(const __be32 *a1, const __be32 *a2, int bits)
+{
+	int words = bits >> 5;
+
+	bits &= 0x1f;
+
+	if (words) {
+		if (memcmp(a1, a2, words << 2))
+			return 0;
+	}
+	if (bits) {
+		__be32 w1, w2;
+		__be32 mask;
+
+		w1 = a1[words];
+		w2 = a2[words];
+
+		mask = htonl((0xffffffff) << (32 - bits));
+
+		if ((w1 ^ w2) & mask)
+			return 0;
+	}
+
+	return 1;
+}
+
+
+static int inet_diag_bc_run(const void *bc, int len,
+			    const struct inet_diag_entry *entry)
+{
+	while (len > 0) {
+		int yes = 1;
+		const struct inet_diag_bc_op *op = bc;
+
+		switch (op->code) {
+		case INET_DIAG_BC_NOP:
+			break;
+		case INET_DIAG_BC_JMP:
+			yes = 0;
+			break;
+		case INET_DIAG_BC_S_GE:
+			yes = entry->sport >= op[1].no;
+			break;
+		case INET_DIAG_BC_S_LE:
+			yes = entry->dport <= op[1].no;
+			break;
+		case INET_DIAG_BC_D_GE:
+			yes = entry->dport >= op[1].no;
+			break;
+		case INET_DIAG_BC_D_LE:
+			yes = entry->dport <= op[1].no;
+			break;
+		case INET_DIAG_BC_AUTO:
+			yes = !(entry->userlocks & SOCK_BINDPORT_LOCK);
+			break;
+		case INET_DIAG_BC_S_COND:
+		case INET_DIAG_BC_D_COND: {
+			struct inet_diag_hostcond *cond;
+			__be32 *addr;
+
+			cond = (struct inet_diag_hostcond *)(op + 1);
+			if (cond->port != -1 &&
+			    cond->port != (op->code == INET_DIAG_BC_S_COND ?
+					     entry->sport : entry->dport)) {
+				yes = 0;
+				break;
+			}
+
+			if (cond->prefix_len == 0)
+				break;
+
+			if (op->code == INET_DIAG_BC_S_COND)
+				addr = entry->saddr;
+			else
+				addr = entry->daddr;
+
+			if (bitstring_match(addr, cond->addr,
+					    cond->prefix_len))
+				break;
+			if (entry->family == AF_INET6 &&
+			    cond->family == AF_INET) {
+				if (addr[0] == 0 && addr[1] == 0 &&
+				    addr[2] == htonl(0xffff) &&
+				    bitstring_match(addr + 3, cond->addr,
+						    cond->prefix_len))
+					break;
+			}
+			yes = 0;
+			break;
+		}
+		}
+
+		if (yes) {
+			len -= op->yes;
+			bc += op->yes;
+		} else {
+			len -= op->no;
+			bc += op->no;
+		}
+	}
+	return (len == 0);
+}
+
+static int valid_cc(const void *bc, int len, int cc)
+{
+	while (len >= 0) {
+		const struct inet_diag_bc_op *op = bc;
+
+		if (cc > len)
+			return 0;
+		if (cc == len)
+			return 1;
+		if (op->yes < 4)
+			return 0;
+		len -= op->yes;
+		bc  += op->yes;
+	}
+	return 0;
+}
+
+static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
+{
+	const unsigned char *bc = bytecode;
+	int  len = bytecode_len;
+
+	while (len > 0) {
+		struct inet_diag_bc_op *op = (struct inet_diag_bc_op *)bc;
+
+//printk("BC: %d %d %d {%d} / %d\n", op->code, op->yes, op->no, op[1].no, len);
+		switch (op->code) {
+		case INET_DIAG_BC_AUTO:
+		case INET_DIAG_BC_S_COND:
+		case INET_DIAG_BC_D_COND:
+		case INET_DIAG_BC_S_GE:
+		case INET_DIAG_BC_S_LE:
+		case INET_DIAG_BC_D_GE:
+		case INET_DIAG_BC_D_LE:
+			if (op->yes < 4 || op->yes > len + 4)
+				return -EINVAL;
+		case INET_DIAG_BC_JMP:
+			if (op->no < 4 || op->no > len + 4)
+				return -EINVAL;
+			if (op->no < len &&
+			    !valid_cc(bytecode, bytecode_len, len - op->no))
+				return -EINVAL;
+			break;
+		case INET_DIAG_BC_NOP:
+			if (op->yes < 4 || op->yes > len + 4)
+				return -EINVAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+		bc  += op->yes;
+		len -= op->yes;
+	}
+	return len == 0 ? 0 : -EINVAL;
+}
+
+static int inet_csk_diag_dump(struct sock *sk,
+			      struct sk_buff *skb,
+			      struct netlink_callback *cb)
+{
+	struct inet_diag_req *r = NLMSG_DATA(cb->nlh);
+
+	if (cb->nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(*r))) {
+		struct inet_diag_entry entry;
+		struct rtattr *bc = (struct rtattr *)(r + 1);
+		struct inet_sock *inet = inet_sk(sk);
+
+		entry.family = sk->sk_family;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+		if (entry.family == AF_INET6) {
+			struct ipv6_pinfo *np = inet6_sk(sk);
+
+			entry.saddr = np->rcv_saddr.s6_addr32;
+			entry.daddr = np->daddr.s6_addr32;
+		} else
+#endif
+		{
+			entry.saddr = &inet->rcv_saddr;
+			entry.daddr = &inet->daddr;
+		}
+		entry.sport = inet->num;
+		entry.dport = ntohs(inet->dport);
+		entry.userlocks = sk->sk_userlocks;
+
+		if (!inet_diag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), &entry))
+			return 0;
+	}
+
+	return inet_csk_diag_fill(sk, skb, r->idiag_ext,
+				  NETLINK_CB(cb->skb).pid,
+				  cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
+}
+
+static int inet_twsk_diag_dump(struct inet_timewait_sock *tw,
+			       struct sk_buff *skb,
+			       struct netlink_callback *cb)
+{
+	struct inet_diag_req *r = NLMSG_DATA(cb->nlh);
+
+	if (cb->nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(*r))) {
+		struct inet_diag_entry entry;
+		struct rtattr *bc = (struct rtattr *)(r + 1);
+
+		entry.family = tw->tw_family;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+		if (tw->tw_family == AF_INET6) {
+			struct inet6_timewait_sock *tw6 =
+						inet6_twsk((struct sock *)tw);
+			entry.saddr = tw6->tw_v6_rcv_saddr.s6_addr32;
+			entry.daddr = tw6->tw_v6_daddr.s6_addr32;
+		} else
+#endif
+		{
+			entry.saddr = &tw->tw_rcv_saddr;
+			entry.daddr = &tw->tw_daddr;
+		}
+		entry.sport = tw->tw_num;
+		entry.dport = ntohs(tw->tw_dport);
+		entry.userlocks = 0;
+
+		if (!inet_diag_bc_run(RTA_DATA(bc), RTA_PAYLOAD(bc), &entry))
+			return 0;
+	}
+
+	return inet_twsk_diag_fill(tw, skb, r->idiag_ext,
+				   NETLINK_CB(cb->skb).pid,
+				   cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
+}
+
+static int inet_diag_fill_req(struct sk_buff *skb, struct sock *sk,
+			      struct request_sock *req, u32 pid, u32 seq,
+			      const struct nlmsghdr *unlh)
+{
+	const struct inet_request_sock *ireq = inet_rsk(req);
+	struct inet_sock *inet = inet_sk(sk);
+	unsigned char *b = skb_tail_pointer(skb);
+	struct inet_diag_msg *r;
+	struct nlmsghdr *nlh;
+	long tmo;
+
+	nlh = NLMSG_PUT(skb, pid, seq, unlh->nlmsg_type, sizeof(*r));
+	nlh->nlmsg_flags = NLM_F_MULTI;
+	r = NLMSG_DATA(nlh);
+
+	r->idiag_family = sk->sk_family;
+	r->idiag_state = TCP_SYN_RECV;
+	r->idiag_timer = 1;
+	r->idiag_retrans = req->retrans;
+
+	r->id.idiag_if = sk->sk_bound_dev_if;
+	r->id.idiag_cookie[0] = (u32)(unsigned long)req;
+	r->id.idiag_cookie[1] = (u32)(((unsigned long)req >> 31) >> 1);
+
+	tmo = req->expires - jiffies;
+	if (tmo < 0)
+		tmo = 0;
+
+	r->id.idiag_sport = inet->sport;
+	r->id.idiag_dport = ireq->rmt_port;
+	r->id.idiag_src[0] = ireq->loc_addr;
+	r->id.idiag_dst[0] = ireq->rmt_addr;
+	r->idiag_expires = jiffies_to_msecs(tmo);
+	r->idiag_rqueue = 0;
+	r->idiag_wqueue = 0;
+	r->idiag_uid = sock_i_uid(sk);
+	r->idiag_inode = 0;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+	if (r->idiag_family == AF_INET6) {
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_src,
+			       &inet6_rsk(req)->loc_addr);
+		ipv6_addr_copy((struct in6_addr *)r->id.idiag_dst,
+			       &inet6_rsk(req)->rmt_addr);
+	}
+#endif
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
+
+	return skb->len;
+
+nlmsg_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int inet_diag_dump_reqs(struct sk_buff *skb, struct sock *sk,
+			       struct netlink_callback *cb)
+{
+	struct inet_diag_entry entry;
+	struct inet_diag_req *r = NLMSG_DATA(cb->nlh);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct listen_sock *lopt;
+	struct rtattr *bc = NULL;
+	struct inet_sock *inet = inet_sk(sk);
+	int j, s_j;
+	int reqnum, s_reqnum;
+	int err = 0;
+
+	s_j = cb->args[3];
+	s_reqnum = cb->args[4];
+
+	if (s_j > 0)
+		s_j--;
+
+	entry.family = sk->sk_family;
+
+	read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+
+	lopt = icsk->icsk_accept_queue.listen_opt;
+	if (!lopt || !lopt->qlen)
+		goto out;
+
+	if (cb->nlh->nlmsg_len > 4 + NLMSG_SPACE(sizeof(*r))) {
+		bc = (struct rtattr *)(r + 1);
+		entry.sport = inet->num;
+		entry.userlocks = sk->sk_userlocks;
+	}
+
+	for (j = s_j; j < lopt->nr_table_entries; j++) {
+		struct request_sock *req, *head = lopt->syn_table[j];
+
+		reqnum = 0;
+		for (req = head; req; reqnum++, req = req->dl_next) {
+			struct inet_request_sock *ireq = inet_rsk(req);
+
+			if (reqnum < s_reqnum)
+				continue;
+			if (r->id.idiag_dport != ireq->rmt_port &&
+			    r->id.idiag_dport)
+				continue;
+
+			if (bc) {
+				entry.saddr =
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+					(entry.family == AF_INET6) ?
+					inet6_rsk(req)->loc_addr.s6_addr32 :
+#endif
+					&ireq->loc_addr;
+				entry.daddr =
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+					(entry.family == AF_INET6) ?
+					inet6_rsk(req)->rmt_addr.s6_addr32 :
+#endif
+					&ireq->rmt_addr;
+				entry.dport = ntohs(ireq->rmt_port);
+
+				if (!inet_diag_bc_run(RTA_DATA(bc),
+						    RTA_PAYLOAD(bc), &entry))
+					continue;
+			}
+
+			err = inet_diag_fill_req(skb, sk, req,
+					       NETLINK_CB(cb->skb).pid,
+					       cb->nlh->nlmsg_seq, cb->nlh);
+			if (err < 0) {
+				cb->args[3] = j + 1;
+				cb->args[4] = reqnum;
+				goto out;
+			}
+		}
+
+		s_reqnum = 0;
+	}
+
+out:
+	read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+
+	return err;
+}
+
+static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int i, num;
+	int s_i, s_num;
+	struct inet_diag_req *r = NLMSG_DATA(cb->nlh);
+	const struct inet_diag_handler *handler;
+	struct inet_hashinfo *hashinfo;
+
+	handler = inet_diag_lock_handler(cb->nlh->nlmsg_type);
+	if (IS_ERR(handler))
+		goto unlock;
+
+	hashinfo = handler->idiag_hashinfo;
+
+	s_i = cb->args[1];
+	s_num = num = cb->args[2];
+
+	if (cb->args[0] == 0) {
+		if (!(r->idiag_states & (TCPF_LISTEN | TCPF_SYN_RECV)))
+			goto skip_listen_ht;
+
+		inet_listen_lock(hashinfo);
+		for (i = s_i; i < INET_LHTABLE_SIZE; i++) {
+			struct sock *sk;
+			struct hlist_node *node;
+
+			num = 0;
+			sk_for_each(sk, node, &hashinfo->listening_hash[i]) {
+				struct inet_sock *inet = inet_sk(sk);
+
+				if (num < s_num) {
+					num++;
+					continue;
+				}
+
+				if (r->id.idiag_sport != inet->sport &&
+				    r->id.idiag_sport)
+					goto next_listen;
+
+				if (!(r->idiag_states & TCPF_LISTEN) ||
+				    r->id.idiag_dport ||
+				    cb->args[3] > 0)
+					goto syn_recv;
+
+				if (inet_csk_diag_dump(sk, skb, cb) < 0) {
+					inet_listen_unlock(hashinfo);
+					goto done;
+				}
+
+syn_recv:
+				if (!(r->idiag_states & TCPF_SYN_RECV))
+					goto next_listen;
+
+				if (inet_diag_dump_reqs(skb, sk, cb) < 0) {
+					inet_listen_unlock(hashinfo);
+					goto done;
+				}
+
+next_listen:
+				cb->args[3] = 0;
+				cb->args[4] = 0;
+				++num;
+			}
+
+			s_num = 0;
+			cb->args[3] = 0;
+			cb->args[4] = 0;
+		}
+		inet_listen_unlock(hashinfo);
+skip_listen_ht:
+		cb->args[0] = 1;
+		s_i = num = s_num = 0;
+	}
+
+	if (!(r->idiag_states & ~(TCPF_LISTEN | TCPF_SYN_RECV)))
+		goto unlock;
+
+	for (i = s_i; i < hashinfo->ehash_size; i++) {
+		struct inet_ehash_bucket *head = &hashinfo->ehash[i];
+		rwlock_t *lock = inet_ehash_lockp(hashinfo, i);
+		struct sock *sk;
+		struct hlist_node *node;
+
+		num = 0;
+
+		if (hlist_empty(&head->chain) && hlist_empty(&head->twchain))
+			continue;
+
+		if (i > s_i)
+			s_num = 0;
+
+		read_lock_bh(lock);
+		sk_for_each(sk, node, &head->chain) {
+			struct inet_sock *inet = inet_sk(sk);
+
+			if (num < s_num)
+				goto next_normal;
+			if (!(r->idiag_states & (1 << sk->sk_state)))
+				goto next_normal;
+			if (r->id.idiag_sport != inet->sport &&
+			    r->id.idiag_sport)
+				goto next_normal;
+			if (r->id.idiag_dport != inet->dport &&
+			    r->id.idiag_dport)
+				goto next_normal;
+			if (inet_csk_diag_dump(sk, skb, cb) < 0) {
+				read_unlock_bh(lock);
+				goto done;
+			}
+next_normal:
+			++num;
+		}
+
+		if (r->idiag_states & TCPF_TIME_WAIT) {
+			struct inet_timewait_sock *tw;
+
+			inet_twsk_for_each(tw, node,
+				    &head->twchain) {
+
+				if (num < s_num)
+					goto next_dying;
+				if (r->id.idiag_sport != tw->tw_sport &&
+				    r->id.idiag_sport)
+					goto next_dying;
+				if (r->id.idiag_dport != tw->tw_dport &&
+				    r->id.idiag_dport)
+					goto next_dying;
+				if (inet_twsk_diag_dump(tw, skb, cb) < 0) {
+					read_unlock_bh(lock);
+					goto done;
+				}
+next_dying:
+				++num;
+			}
+		}
+		read_unlock_bh(lock);
+	}
+
+done:
+	cb->args[1] = i;
+	cb->args[2] = num;
+unlock:
+	inet_diag_unlock_handler(handler);
+	return skb->len;
+}
+
+static int inet_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+	int hdrlen = sizeof(struct inet_diag_req);
+
+	if (nlh->nlmsg_type >= INET_DIAG_GETSOCK_MAX ||
+	    nlmsg_len(nlh) < hdrlen)
+		return -EINVAL;
+
+	if (nlh->nlmsg_flags & NLM_F_DUMP) {
+		if (nlmsg_attrlen(nlh, hdrlen)) {
+			struct nlattr *attr;
+
+			attr = nlmsg_find_attr(nlh, hdrlen,
+					       INET_DIAG_REQ_BYTECODE);
+			if (attr == NULL ||
+			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
+			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
+				return -EINVAL;
+		}
+
+		return netlink_dump_start(idiagnl, skb, nlh,
+					  inet_diag_dump, NULL);
+	}
+
+	return inet_diag_get_exact(skb, nlh);
+}
+
+static DEFINE_MUTEX(inet_diag_mutex);
+
+static void inet_diag_rcv(struct sk_buff *skb)
+{
+	mutex_lock(&inet_diag_mutex);
+	netlink_rcv_skb(skb, &inet_diag_rcv_msg);
+	mutex_unlock(&inet_diag_mutex);
+}
+
+int inet_diag_register(const struct inet_diag_handler *h)
+{
+	const __u16 type = h->idiag_type;
+	int err = -EINVAL;
+
+	if (type >= INET_DIAG_GETSOCK_MAX)
+		goto out;
+
+	mutex_lock(&inet_diag_table_mutex);
+	err = -EEXIST;
+	if (inet_diag_table[type] == NULL) {
+		inet_diag_table[type] = h;
+		err = 0;
+	}
+	mutex_unlock(&inet_diag_table_mutex);
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(inet_diag_register);
+
+void inet_diag_unregister(const struct inet_diag_handler *h)
+{
+	const __u16 type = h->idiag_type;
+
+	if (type >= INET_DIAG_GETSOCK_MAX)
+		return;
+
+	mutex_lock(&inet_diag_table_mutex);
+	inet_diag_table[type] = NULL;
+	mutex_unlock(&inet_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(inet_diag_unregister);
+
+static int __init inet_diag_init(void)
+{
+	const int inet_diag_table_size = (INET_DIAG_GETSOCK_MAX *
+					  sizeof(struct inet_diag_handler *));
+	int err = -ENOMEM;
+
+	inet_diag_table = kzalloc(inet_diag_table_size, GFP_KERNEL);
+	if (!inet_diag_table)
+		goto out;
+
+	idiagnl = netlink_kernel_create(&init_net, NETLINK_INET_DIAG, 0,
+					inet_diag_rcv, NULL, THIS_MODULE);
+	if (idiagnl == NULL)
+		goto out_free_table;
+	err = 0;
+out:
+	return err;
+out_free_table:
+	kfree(inet_diag_table);
+	goto out;
+}
+
+static void __exit inet_diag_exit(void)
+{
+	netlink_kernel_release(idiagnl);
+	kfree(inet_diag_table);
+}
+
+module_init(inet_diag_init);
+module_exit(inet_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_INET_DIAG);
diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c
new file mode 100644
index 0000000..6c52e08
--- /dev/null
+++ b/net/ipv4/inet_fragment.c
@@ -0,0 +1,285 @@
+/*
+ * inet fragments management
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * 		Authors:	Pavel Emelyanov <xemul@openvz.org>
+ *				Started as consolidation of ipv4/ip_fragment.c,
+ *				ipv6/reassembly. and ipv6 nf conntrack reassembly
+ */
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/random.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+
+#include <net/inet_frag.h>
+
+static void inet_frag_secret_rebuild(unsigned long dummy)
+{
+	struct inet_frags *f = (struct inet_frags *)dummy;
+	unsigned long now = jiffies;
+	int i;
+
+	write_lock(&f->lock);
+	get_random_bytes(&f->rnd, sizeof(u32));
+	for (i = 0; i < INETFRAGS_HASHSZ; i++) {
+		struct inet_frag_queue *q;
+		struct hlist_node *p, *n;
+
+		hlist_for_each_entry_safe(q, p, n, &f->hash[i], list) {
+			unsigned int hval = f->hashfn(q);
+
+			if (hval != i) {
+				hlist_del(&q->list);
+
+				/* Relink to new hash chain. */
+				hlist_add_head(&q->list, &f->hash[hval]);
+			}
+		}
+	}
+	write_unlock(&f->lock);
+
+	mod_timer(&f->secret_timer, now + f->secret_interval);
+}
+
+void inet_frags_init(struct inet_frags *f)
+{
+	int i;
+
+	for (i = 0; i < INETFRAGS_HASHSZ; i++)
+		INIT_HLIST_HEAD(&f->hash[i]);
+
+	rwlock_init(&f->lock);
+
+	f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
+				   (jiffies ^ (jiffies >> 6)));
+
+	setup_timer(&f->secret_timer, inet_frag_secret_rebuild,
+			(unsigned long)f);
+	f->secret_timer.expires = jiffies + f->secret_interval;
+	add_timer(&f->secret_timer);
+}
+EXPORT_SYMBOL(inet_frags_init);
+
+void inet_frags_init_net(struct netns_frags *nf)
+{
+	nf->nqueues = 0;
+	atomic_set(&nf->mem, 0);
+	INIT_LIST_HEAD(&nf->lru_list);
+}
+EXPORT_SYMBOL(inet_frags_init_net);
+
+void inet_frags_fini(struct inet_frags *f)
+{
+	del_timer(&f->secret_timer);
+}
+EXPORT_SYMBOL(inet_frags_fini);
+
+void inet_frags_exit_net(struct netns_frags *nf, struct inet_frags *f)
+{
+	nf->low_thresh = 0;
+
+	local_bh_disable();
+	inet_frag_evictor(nf, f);
+	local_bh_enable();
+}
+EXPORT_SYMBOL(inet_frags_exit_net);
+
+static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
+{
+	write_lock(&f->lock);
+	hlist_del(&fq->list);
+	list_del(&fq->lru_list);
+	fq->net->nqueues--;
+	write_unlock(&f->lock);
+}
+
+void inet_frag_kill(struct inet_frag_queue *fq, struct inet_frags *f)
+{
+	if (del_timer(&fq->timer))
+		atomic_dec(&fq->refcnt);
+
+	if (!(fq->last_in & INET_FRAG_COMPLETE)) {
+		fq_unlink(fq, f);
+		atomic_dec(&fq->refcnt);
+		fq->last_in |= INET_FRAG_COMPLETE;
+	}
+}
+
+EXPORT_SYMBOL(inet_frag_kill);
+
+static inline void frag_kfree_skb(struct netns_frags *nf, struct inet_frags *f,
+		struct sk_buff *skb, int *work)
+{
+	if (work)
+		*work -= skb->truesize;
+
+	atomic_sub(skb->truesize, &nf->mem);
+	if (f->skb_free)
+		f->skb_free(skb);
+	kfree_skb(skb);
+}
+
+void inet_frag_destroy(struct inet_frag_queue *q, struct inet_frags *f,
+					int *work)
+{
+	struct sk_buff *fp;
+	struct netns_frags *nf;
+
+	WARN_ON(!(q->last_in & INET_FRAG_COMPLETE));
+	WARN_ON(del_timer(&q->timer) != 0);
+
+	/* Release all fragment data. */
+	fp = q->fragments;
+	nf = q->net;
+	while (fp) {
+		struct sk_buff *xp = fp->next;
+
+		frag_kfree_skb(nf, f, fp, work);
+		fp = xp;
+	}
+
+	if (work)
+		*work -= f->qsize;
+	atomic_sub(f->qsize, &nf->mem);
+
+	if (f->destructor)
+		f->destructor(q);
+	kfree(q);
+
+}
+EXPORT_SYMBOL(inet_frag_destroy);
+
+int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f)
+{
+	struct inet_frag_queue *q;
+	int work, evicted = 0;
+
+	work = atomic_read(&nf->mem) - nf->low_thresh;
+	while (work > 0) {
+		read_lock(&f->lock);
+		if (list_empty(&nf->lru_list)) {
+			read_unlock(&f->lock);
+			break;
+		}
+
+		q = list_first_entry(&nf->lru_list,
+				struct inet_frag_queue, lru_list);
+		atomic_inc(&q->refcnt);
+		read_unlock(&f->lock);
+
+		spin_lock(&q->lock);
+		if (!(q->last_in & INET_FRAG_COMPLETE))
+			inet_frag_kill(q, f);
+		spin_unlock(&q->lock);
+
+		if (atomic_dec_and_test(&q->refcnt))
+			inet_frag_destroy(q, f, &work);
+		evicted++;
+	}
+
+	return evicted;
+}
+EXPORT_SYMBOL(inet_frag_evictor);
+
+static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
+		struct inet_frag_queue *qp_in, struct inet_frags *f,
+		void *arg)
+{
+	struct inet_frag_queue *qp;
+#ifdef CONFIG_SMP
+	struct hlist_node *n;
+#endif
+	unsigned int hash;
+
+	write_lock(&f->lock);
+	/*
+	 * While we stayed w/o the lock other CPU could update
+	 * the rnd seed, so we need to re-calculate the hash
+	 * chain. Fortunatelly the qp_in can be used to get one.
+	 */
+	hash = f->hashfn(qp_in);
+#ifdef CONFIG_SMP
+	/* With SMP race we have to recheck hash table, because
+	 * such entry could be created on other cpu, while we
+	 * promoted read lock to write lock.
+	 */
+	hlist_for_each_entry(qp, n, &f->hash[hash], list) {
+		if (qp->net == nf && f->match(qp, arg)) {
+			atomic_inc(&qp->refcnt);
+			write_unlock(&f->lock);
+			qp_in->last_in |= INET_FRAG_COMPLETE;
+			inet_frag_put(qp_in, f);
+			return qp;
+		}
+	}
+#endif
+	qp = qp_in;
+	if (!mod_timer(&qp->timer, jiffies + nf->timeout))
+		atomic_inc(&qp->refcnt);
+
+	atomic_inc(&qp->refcnt);
+	hlist_add_head(&qp->list, &f->hash[hash]);
+	list_add_tail(&qp->lru_list, &nf->lru_list);
+	nf->nqueues++;
+	write_unlock(&f->lock);
+	return qp;
+}
+
+static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
+		struct inet_frags *f, void *arg)
+{
+	struct inet_frag_queue *q;
+
+	q = kzalloc(f->qsize, GFP_ATOMIC);
+	if (q == NULL)
+		return NULL;
+
+	f->constructor(q, arg);
+	atomic_add(f->qsize, &nf->mem);
+	setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
+	spin_lock_init(&q->lock);
+	atomic_set(&q->refcnt, 1);
+	q->net = nf;
+
+	return q;
+}
+
+static struct inet_frag_queue *inet_frag_create(struct netns_frags *nf,
+		struct inet_frags *f, void *arg)
+{
+	struct inet_frag_queue *q;
+
+	q = inet_frag_alloc(nf, f, arg);
+	if (q == NULL)
+		return NULL;
+
+	return inet_frag_intern(nf, q, f, arg);
+}
+
+struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
+		struct inet_frags *f, void *key, unsigned int hash)
+{
+	struct inet_frag_queue *q;
+	struct hlist_node *n;
+
+	hlist_for_each_entry(q, n, &f->hash[hash], list) {
+		if (q->net == nf && f->match(q, key)) {
+			atomic_inc(&q->refcnt);
+			read_unlock(&f->lock);
+			return q;
+		}
+	}
+	read_unlock(&f->lock);
+
+	return inet_frag_create(nf, f, key);
+}
+EXPORT_SYMBOL(inet_frag_find);
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
new file mode 100644
index 0000000..4498190
--- /dev/null
+++ b/net/ipv4/inet_hashtables.c
@@ -0,0 +1,526 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Generic INET transport hashtables
+ *
+ * Authors:	Lotsa people, from code originally in tcp
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include <net/inet_connection_sock.h>
+#include <net/inet_hashtables.h>
+#include <net/ip.h>
+
+/*
+ * Allocate and initialize a new local port bind bucket.
+ * The bindhash mutex for snum's hash chain must be held here.
+ */
+struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
+						 struct net *net,
+						 struct inet_bind_hashbucket *head,
+						 const unsigned short snum)
+{
+	struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
+
+	if (tb != NULL) {
+		tb->ib_net       = hold_net(net);
+		tb->port      = snum;
+		tb->fastreuse = 0;
+		INIT_HLIST_HEAD(&tb->owners);
+		hlist_add_head(&tb->node, &head->chain);
+	}
+	return tb;
+}
+
+/*
+ * Caller must hold hashbucket lock for this tb with local BH disabled
+ */
+void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket *tb)
+{
+	if (hlist_empty(&tb->owners)) {
+		__hlist_del(&tb->node);
+		release_net(tb->ib_net);
+		kmem_cache_free(cachep, tb);
+	}
+}
+
+void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
+		    const unsigned short snum)
+{
+	inet_sk(sk)->num = snum;
+	sk_add_bind_node(sk, &tb->owners);
+	inet_csk(sk)->icsk_bind_hash = tb;
+}
+
+/*
+ * Get rid of any references to a local port held by the given sock.
+ */
+static void __inet_put_port(struct sock *sk)
+{
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+	const int bhash = inet_bhashfn(sock_net(sk), inet_sk(sk)->num,
+			hashinfo->bhash_size);
+	struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
+	struct inet_bind_bucket *tb;
+
+	spin_lock(&head->lock);
+	tb = inet_csk(sk)->icsk_bind_hash;
+	__sk_del_bind_node(sk);
+	inet_csk(sk)->icsk_bind_hash = NULL;
+	inet_sk(sk)->num = 0;
+	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+	spin_unlock(&head->lock);
+}
+
+void inet_put_port(struct sock *sk)
+{
+	local_bh_disable();
+	__inet_put_port(sk);
+	local_bh_enable();
+}
+
+EXPORT_SYMBOL(inet_put_port);
+
+void __inet_inherit_port(struct sock *sk, struct sock *child)
+{
+	struct inet_hashinfo *table = sk->sk_prot->h.hashinfo;
+	const int bhash = inet_bhashfn(sock_net(sk), inet_sk(child)->num,
+			table->bhash_size);
+	struct inet_bind_hashbucket *head = &table->bhash[bhash];
+	struct inet_bind_bucket *tb;
+
+	spin_lock(&head->lock);
+	tb = inet_csk(sk)->icsk_bind_hash;
+	sk_add_bind_node(child, &tb->owners);
+	inet_csk(child)->icsk_bind_hash = tb;
+	spin_unlock(&head->lock);
+}
+
+EXPORT_SYMBOL_GPL(__inet_inherit_port);
+
+/*
+ * This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
+ * Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines (wake up each
+ * exclusive lock release). It should be ifdefed really.
+ */
+void inet_listen_wlock(struct inet_hashinfo *hashinfo)
+	__acquires(hashinfo->lhash_lock)
+{
+	write_lock(&hashinfo->lhash_lock);
+
+	if (atomic_read(&hashinfo->lhash_users)) {
+		DEFINE_WAIT(wait);
+
+		for (;;) {
+			prepare_to_wait_exclusive(&hashinfo->lhash_wait,
+						  &wait, TASK_UNINTERRUPTIBLE);
+			if (!atomic_read(&hashinfo->lhash_users))
+				break;
+			write_unlock_bh(&hashinfo->lhash_lock);
+			schedule();
+			write_lock_bh(&hashinfo->lhash_lock);
+		}
+
+		finish_wait(&hashinfo->lhash_wait, &wait);
+	}
+}
+
+/*
+ * Don't inline this cruft. Here are some nice properties to exploit here. The
+ * BSD API does not allow a listening sock to specify the remote port nor the
+ * remote address for the connection. So always assume those are both
+ * wildcarded during the search since they can never be otherwise.
+ */
+static struct sock *inet_lookup_listener_slow(struct net *net,
+					      const struct hlist_head *head,
+					      const __be32 daddr,
+					      const unsigned short hnum,
+					      const int dif)
+{
+	struct sock *result = NULL, *sk;
+	const struct hlist_node *node;
+	int hiscore = -1;
+
+	sk_for_each(sk, node, head) {
+		const struct inet_sock *inet = inet_sk(sk);
+
+		if (net_eq(sock_net(sk), net) && inet->num == hnum &&
+				!ipv6_only_sock(sk)) {
+			const __be32 rcv_saddr = inet->rcv_saddr;
+			int score = sk->sk_family == PF_INET ? 1 : 0;
+
+			if (rcv_saddr) {
+				if (rcv_saddr != daddr)
+					continue;
+				score += 2;
+			}
+			if (sk->sk_bound_dev_if) {
+				if (sk->sk_bound_dev_if != dif)
+					continue;
+				score += 2;
+			}
+			if (score == 5)
+				return sk;
+			if (score > hiscore) {
+				hiscore	= score;
+				result	= sk;
+			}
+		}
+	}
+	return result;
+}
+
+/* Optimize the common listener case. */
+struct sock *__inet_lookup_listener(struct net *net,
+				    struct inet_hashinfo *hashinfo,
+				    const __be32 daddr, const unsigned short hnum,
+				    const int dif)
+{
+	struct sock *sk = NULL;
+	const struct hlist_head *head;
+
+	read_lock(&hashinfo->lhash_lock);
+	head = &hashinfo->listening_hash[inet_lhashfn(net, hnum)];
+	if (!hlist_empty(head)) {
+		const struct inet_sock *inet = inet_sk((sk = __sk_head(head)));
+
+		if (inet->num == hnum && !sk->sk_node.next &&
+		    (!inet->rcv_saddr || inet->rcv_saddr == daddr) &&
+		    (sk->sk_family == PF_INET || !ipv6_only_sock(sk)) &&
+		    !sk->sk_bound_dev_if && net_eq(sock_net(sk), net))
+			goto sherry_cache;
+		sk = inet_lookup_listener_slow(net, head, daddr, hnum, dif);
+	}
+	if (sk) {
+sherry_cache:
+		sock_hold(sk);
+	}
+	read_unlock(&hashinfo->lhash_lock);
+	return sk;
+}
+EXPORT_SYMBOL_GPL(__inet_lookup_listener);
+
+struct sock * __inet_lookup_established(struct net *net,
+				  struct inet_hashinfo *hashinfo,
+				  const __be32 saddr, const __be16 sport,
+				  const __be32 daddr, const u16 hnum,
+				  const int dif)
+{
+	INET_ADDR_COOKIE(acookie, saddr, daddr)
+	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
+	struct sock *sk;
+	const struct hlist_node *node;
+	/* Optimize here for direct hit, only listening connections can
+	 * have wildcards anyways.
+	 */
+	unsigned int hash = inet_ehashfn(net, daddr, hnum, saddr, sport);
+	struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
+	rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);
+
+	prefetch(head->chain.first);
+	read_lock(lock);
+	sk_for_each(sk, node, &head->chain) {
+		if (INET_MATCH(sk, net, hash, acookie,
+					saddr, daddr, ports, dif))
+			goto hit; /* You sunk my battleship! */
+	}
+
+	/* Must check for a TIME_WAIT'er before going to listener hash. */
+	sk_for_each(sk, node, &head->twchain) {
+		if (INET_TW_MATCH(sk, net, hash, acookie,
+					saddr, daddr, ports, dif))
+			goto hit;
+	}
+	sk = NULL;
+out:
+	read_unlock(lock);
+	return sk;
+hit:
+	sock_hold(sk);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(__inet_lookup_established);
+
+/* called with local bh disabled */
+static int __inet_check_established(struct inet_timewait_death_row *death_row,
+				    struct sock *sk, __u16 lport,
+				    struct inet_timewait_sock **twp)
+{
+	struct inet_hashinfo *hinfo = death_row->hashinfo;
+	struct inet_sock *inet = inet_sk(sk);
+	__be32 daddr = inet->rcv_saddr;
+	__be32 saddr = inet->daddr;
+	int dif = sk->sk_bound_dev_if;
+	INET_ADDR_COOKIE(acookie, saddr, daddr)
+	const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
+	struct net *net = sock_net(sk);
+	unsigned int hash = inet_ehashfn(net, daddr, lport, saddr, inet->dport);
+	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
+	rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
+	struct sock *sk2;
+	const struct hlist_node *node;
+	struct inet_timewait_sock *tw;
+
+	prefetch(head->chain.first);
+	write_lock(lock);
+
+	/* Check TIME-WAIT sockets first. */
+	sk_for_each(sk2, node, &head->twchain) {
+		tw = inet_twsk(sk2);
+
+		if (INET_TW_MATCH(sk2, net, hash, acookie,
+					saddr, daddr, ports, dif)) {
+			if (twsk_unique(sk, sk2, twp))
+				goto unique;
+			else
+				goto not_unique;
+		}
+	}
+	tw = NULL;
+
+	/* And established part... */
+	sk_for_each(sk2, node, &head->chain) {
+		if (INET_MATCH(sk2, net, hash, acookie,
+					saddr, daddr, ports, dif))
+			goto not_unique;
+	}
+
+unique:
+	/* Must record num and sport now. Otherwise we will see
+	 * in hash table socket with a funny identity. */
+	inet->num = lport;
+	inet->sport = htons(lport);
+	sk->sk_hash = hash;
+	WARN_ON(!sk_unhashed(sk));
+	__sk_add_node(sk, &head->chain);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	write_unlock(lock);
+
+	if (twp) {
+		*twp = tw;
+		NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
+	} else if (tw) {
+		/* Silly. Should hash-dance instead... */
+		inet_twsk_deschedule(tw, death_row);
+		NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
+
+		inet_twsk_put(tw);
+	}
+
+	return 0;
+
+not_unique:
+	write_unlock(lock);
+	return -EADDRNOTAVAIL;
+}
+
+static inline u32 inet_sk_port_offset(const struct sock *sk)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	return secure_ipv4_port_ephemeral(inet->rcv_saddr, inet->daddr,
+					  inet->dport);
+}
+
+void __inet_hash_nolisten(struct sock *sk)
+{
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+	struct hlist_head *list;
+	rwlock_t *lock;
+	struct inet_ehash_bucket *head;
+
+	WARN_ON(!sk_unhashed(sk));
+
+	sk->sk_hash = inet_sk_ehashfn(sk);
+	head = inet_ehash_bucket(hashinfo, sk->sk_hash);
+	list = &head->chain;
+	lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
+
+	write_lock(lock);
+	__sk_add_node(sk, list);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	write_unlock(lock);
+}
+EXPORT_SYMBOL_GPL(__inet_hash_nolisten);
+
+static void __inet_hash(struct sock *sk)
+{
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+	struct hlist_head *list;
+	rwlock_t *lock;
+
+	if (sk->sk_state != TCP_LISTEN) {
+		__inet_hash_nolisten(sk);
+		return;
+	}
+
+	WARN_ON(!sk_unhashed(sk));
+	list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
+	lock = &hashinfo->lhash_lock;
+
+	inet_listen_wlock(hashinfo);
+	__sk_add_node(sk, list);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	write_unlock(lock);
+	wake_up(&hashinfo->lhash_wait);
+}
+
+void inet_hash(struct sock *sk)
+{
+	if (sk->sk_state != TCP_CLOSE) {
+		local_bh_disable();
+		__inet_hash(sk);
+		local_bh_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(inet_hash);
+
+void inet_unhash(struct sock *sk)
+{
+	rwlock_t *lock;
+	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
+
+	if (sk_unhashed(sk))
+		goto out;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		local_bh_disable();
+		inet_listen_wlock(hashinfo);
+		lock = &hashinfo->lhash_lock;
+	} else {
+		lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
+		write_lock_bh(lock);
+	}
+
+	if (__sk_del_node_init(sk))
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	write_unlock_bh(lock);
+out:
+	if (sk->sk_state == TCP_LISTEN)
+		wake_up(&hashinfo->lhash_wait);
+}
+EXPORT_SYMBOL_GPL(inet_unhash);
+
+int __inet_hash_connect(struct inet_timewait_death_row *death_row,
+		struct sock *sk, u32 port_offset,
+		int (*check_established)(struct inet_timewait_death_row *,
+			struct sock *, __u16, struct inet_timewait_sock **),
+		void (*hash)(struct sock *sk))
+{
+	struct inet_hashinfo *hinfo = death_row->hashinfo;
+	const unsigned short snum = inet_sk(sk)->num;
+	struct inet_bind_hashbucket *head;
+	struct inet_bind_bucket *tb;
+	int ret;
+	struct net *net = sock_net(sk);
+
+	if (!snum) {
+		int i, remaining, low, high, port;
+		static u32 hint;
+		u32 offset = hint + port_offset;
+		struct hlist_node *node;
+		struct inet_timewait_sock *tw = NULL;
+
+		inet_get_local_port_range(&low, &high);
+		remaining = (high - low) + 1;
+
+		local_bh_disable();
+		for (i = 1; i <= remaining; i++) {
+			port = low + (i + offset) % remaining;
+			head = &hinfo->bhash[inet_bhashfn(net, port,
+					hinfo->bhash_size)];
+			spin_lock(&head->lock);
+
+			/* Does not bother with rcv_saddr checks,
+			 * because the established check is already
+			 * unique enough.
+			 */
+			inet_bind_bucket_for_each(tb, node, &head->chain) {
+				if (tb->ib_net == net && tb->port == port) {
+					WARN_ON(hlist_empty(&tb->owners));
+					if (tb->fastreuse >= 0)
+						goto next_port;
+					if (!check_established(death_row, sk,
+								port, &tw))
+						goto ok;
+					goto next_port;
+				}
+			}
+
+			tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
+					net, head, port);
+			if (!tb) {
+				spin_unlock(&head->lock);
+				break;
+			}
+			tb->fastreuse = -1;
+			goto ok;
+
+		next_port:
+			spin_unlock(&head->lock);
+		}
+		local_bh_enable();
+
+		return -EADDRNOTAVAIL;
+
+ok:
+		hint += i;
+
+		/* Head lock still held and bh's disabled */
+		inet_bind_hash(sk, tb, port);
+		if (sk_unhashed(sk)) {
+			inet_sk(sk)->sport = htons(port);
+			hash(sk);
+		}
+		spin_unlock(&head->lock);
+
+		if (tw) {
+			inet_twsk_deschedule(tw, death_row);
+			inet_twsk_put(tw);
+		}
+
+		ret = 0;
+		goto out;
+	}
+
+	head = &hinfo->bhash[inet_bhashfn(net, snum, hinfo->bhash_size)];
+	tb  = inet_csk(sk)->icsk_bind_hash;
+	spin_lock_bh(&head->lock);
+	if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
+		hash(sk);
+		spin_unlock_bh(&head->lock);
+		return 0;
+	} else {
+		spin_unlock(&head->lock);
+		/* No definite answer... Walk to established hash table */
+		ret = check_established(death_row, sk, snum, NULL);
+out:
+		local_bh_enable();
+		return ret;
+	}
+}
+
+/*
+ * Bind a port for a connect operation and hash it.
+ */
+int inet_hash_connect(struct inet_timewait_death_row *death_row,
+		      struct sock *sk)
+{
+	return __inet_hash_connect(death_row, sk, inet_sk_port_offset(sk),
+			__inet_check_established, __inet_hash_nolisten);
+}
+
+EXPORT_SYMBOL_GPL(inet_hash_connect);
diff --git a/net/ipv4/inet_lro.c b/net/ipv4/inet_lro.c
new file mode 100644
index 0000000..cfd034a
--- /dev/null
+++ b/net/ipv4/inet_lro.c
@@ -0,0 +1,600 @@
+/*
+ *  linux/net/ipv4/inet_lro.c
+ *
+ *  Large Receive Offload (ipv4 / tcp)
+ *
+ *  (C) Copyright IBM Corp. 2007
+ *
+ *  Authors:
+ *       Jan-Bernd Themann <themann@de.ibm.com>
+ *       Christoph Raisch <raisch@de.ibm.com>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/if_vlan.h>
+#include <linux/inet_lro.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jan-Bernd Themann <themann@de.ibm.com>");
+MODULE_DESCRIPTION("Large Receive Offload (ipv4 / tcp)");
+
+#define TCP_HDR_LEN(tcph) (tcph->doff << 2)
+#define IP_HDR_LEN(iph) (iph->ihl << 2)
+#define TCP_PAYLOAD_LENGTH(iph, tcph) \
+	(ntohs(iph->tot_len) - IP_HDR_LEN(iph) - TCP_HDR_LEN(tcph))
+
+#define IPH_LEN_WO_OPTIONS 5
+#define TCPH_LEN_WO_OPTIONS 5
+#define TCPH_LEN_W_TIMESTAMP 8
+
+#define LRO_MAX_PG_HLEN 64
+
+#define LRO_INC_STATS(lro_mgr, attr) { lro_mgr->stats.attr++; }
+
+/*
+ * Basic tcp checks whether packet is suitable for LRO
+ */
+
+static int lro_tcp_ip_check(struct iphdr *iph, struct tcphdr *tcph,
+			    int len, struct net_lro_desc *lro_desc)
+{
+        /* check ip header: don't aggregate padded frames */
+	if (ntohs(iph->tot_len) != len)
+		return -1;
+
+	if (TCP_PAYLOAD_LENGTH(iph, tcph) == 0)
+		return -1;
+
+	if (iph->ihl != IPH_LEN_WO_OPTIONS)
+		return -1;
+
+	if (tcph->cwr || tcph->ece || tcph->urg || !tcph->ack
+	    || tcph->rst || tcph->syn || tcph->fin)
+		return -1;
+
+	if (INET_ECN_is_ce(ipv4_get_dsfield(iph)))
+		return -1;
+
+	if (tcph->doff != TCPH_LEN_WO_OPTIONS
+	    && tcph->doff != TCPH_LEN_W_TIMESTAMP)
+		return -1;
+
+	/* check tcp options (only timestamp allowed) */
+	if (tcph->doff == TCPH_LEN_W_TIMESTAMP) {
+		__be32 *topt = (__be32 *)(tcph + 1);
+
+		if (*topt != htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16)
+				   | (TCPOPT_TIMESTAMP << 8)
+				   | TCPOLEN_TIMESTAMP))
+			return -1;
+
+		/* timestamp should be in right order */
+		topt++;
+		if (lro_desc && after(ntohl(lro_desc->tcp_rcv_tsval),
+				      ntohl(*topt)))
+			return -1;
+
+		/* timestamp reply should not be zero */
+		topt++;
+		if (*topt == 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+static void lro_update_tcp_ip_header(struct net_lro_desc *lro_desc)
+{
+	struct iphdr *iph = lro_desc->iph;
+	struct tcphdr *tcph = lro_desc->tcph;
+	__be32 *p;
+	__wsum tcp_hdr_csum;
+
+	tcph->ack_seq = lro_desc->tcp_ack;
+	tcph->window = lro_desc->tcp_window;
+
+	if (lro_desc->tcp_saw_tstamp) {
+		p = (__be32 *)(tcph + 1);
+		*(p+2) = lro_desc->tcp_rcv_tsecr;
+	}
+
+	iph->tot_len = htons(lro_desc->ip_tot_len);
+
+	iph->check = 0;
+	iph->check = ip_fast_csum((u8 *)lro_desc->iph, iph->ihl);
+
+	tcph->check = 0;
+	tcp_hdr_csum = csum_partial((u8 *)tcph, TCP_HDR_LEN(tcph), 0);
+	lro_desc->data_csum = csum_add(lro_desc->data_csum, tcp_hdr_csum);
+	tcph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+					lro_desc->ip_tot_len -
+					IP_HDR_LEN(iph), IPPROTO_TCP,
+					lro_desc->data_csum);
+}
+
+static __wsum lro_tcp_data_csum(struct iphdr *iph, struct tcphdr *tcph, int len)
+{
+	__wsum tcp_csum;
+	__wsum tcp_hdr_csum;
+	__wsum tcp_ps_hdr_csum;
+
+	tcp_csum = ~csum_unfold(tcph->check);
+	tcp_hdr_csum = csum_partial((u8 *)tcph, TCP_HDR_LEN(tcph), tcp_csum);
+
+	tcp_ps_hdr_csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
+					     len + TCP_HDR_LEN(tcph),
+					     IPPROTO_TCP, 0);
+
+	return csum_sub(csum_sub(tcp_csum, tcp_hdr_csum),
+			tcp_ps_hdr_csum);
+}
+
+static void lro_init_desc(struct net_lro_desc *lro_desc, struct sk_buff *skb,
+			  struct iphdr *iph, struct tcphdr *tcph,
+			  u16 vlan_tag, struct vlan_group *vgrp)
+{
+	int nr_frags;
+	__be32 *ptr;
+	u32 tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph);
+
+	nr_frags = skb_shinfo(skb)->nr_frags;
+	lro_desc->parent = skb;
+	lro_desc->next_frag = &(skb_shinfo(skb)->frags[nr_frags]);
+	lro_desc->iph = iph;
+	lro_desc->tcph = tcph;
+	lro_desc->tcp_next_seq = ntohl(tcph->seq) + tcp_data_len;
+	lro_desc->tcp_ack = tcph->ack_seq;
+	lro_desc->tcp_window = tcph->window;
+
+	lro_desc->pkt_aggr_cnt = 1;
+	lro_desc->ip_tot_len = ntohs(iph->tot_len);
+
+	if (tcph->doff == 8) {
+		ptr = (__be32 *)(tcph+1);
+		lro_desc->tcp_saw_tstamp = 1;
+		lro_desc->tcp_rcv_tsval = *(ptr+1);
+		lro_desc->tcp_rcv_tsecr = *(ptr+2);
+	}
+
+	lro_desc->mss = tcp_data_len;
+	lro_desc->vgrp = vgrp;
+	lro_desc->vlan_tag = vlan_tag;
+	lro_desc->active = 1;
+
+	lro_desc->data_csum = lro_tcp_data_csum(iph, tcph,
+						tcp_data_len);
+}
+
+static inline void lro_clear_desc(struct net_lro_desc *lro_desc)
+{
+	memset(lro_desc, 0, sizeof(struct net_lro_desc));
+}
+
+static void lro_add_common(struct net_lro_desc *lro_desc, struct iphdr *iph,
+			   struct tcphdr *tcph, int tcp_data_len)
+{
+	struct sk_buff *parent = lro_desc->parent;
+	__be32 *topt;
+
+	lro_desc->pkt_aggr_cnt++;
+	lro_desc->ip_tot_len += tcp_data_len;
+	lro_desc->tcp_next_seq += tcp_data_len;
+	lro_desc->tcp_window = tcph->window;
+	lro_desc->tcp_ack = tcph->ack_seq;
+
+	/* don't update tcp_rcv_tsval, would not work with PAWS */
+	if (lro_desc->tcp_saw_tstamp) {
+		topt = (__be32 *) (tcph + 1);
+		lro_desc->tcp_rcv_tsecr = *(topt + 2);
+	}
+
+	lro_desc->data_csum = csum_block_add(lro_desc->data_csum,
+					     lro_tcp_data_csum(iph, tcph,
+							       tcp_data_len),
+					     parent->len);
+
+	parent->len += tcp_data_len;
+	parent->data_len += tcp_data_len;
+	if (tcp_data_len > lro_desc->mss)
+		lro_desc->mss = tcp_data_len;
+}
+
+static void lro_add_packet(struct net_lro_desc *lro_desc, struct sk_buff *skb,
+			   struct iphdr *iph, struct tcphdr *tcph)
+{
+	struct sk_buff *parent = lro_desc->parent;
+	int tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph);
+
+	lro_add_common(lro_desc, iph, tcph, tcp_data_len);
+
+	skb_pull(skb, (skb->len - tcp_data_len));
+	parent->truesize += skb->truesize;
+
+	if (lro_desc->last_skb)
+		lro_desc->last_skb->next = skb;
+	else
+		skb_shinfo(parent)->frag_list = skb;
+
+	lro_desc->last_skb = skb;
+}
+
+static void lro_add_frags(struct net_lro_desc *lro_desc,
+			  int len, int hlen, int truesize,
+			  struct skb_frag_struct *skb_frags,
+			  struct iphdr *iph, struct tcphdr *tcph)
+{
+	struct sk_buff *skb = lro_desc->parent;
+	int tcp_data_len = TCP_PAYLOAD_LENGTH(iph, tcph);
+
+	lro_add_common(lro_desc, iph, tcph, tcp_data_len);
+
+	skb->truesize += truesize;
+
+	skb_frags[0].page_offset += hlen;
+	skb_frags[0].size -= hlen;
+
+	while (tcp_data_len > 0) {
+		*(lro_desc->next_frag) = *skb_frags;
+		tcp_data_len -= skb_frags->size;
+		lro_desc->next_frag++;
+		skb_frags++;
+		skb_shinfo(skb)->nr_frags++;
+	}
+}
+
+static int lro_check_tcp_conn(struct net_lro_desc *lro_desc,
+			      struct iphdr *iph,
+			      struct tcphdr *tcph)
+{
+	if ((lro_desc->iph->saddr != iph->saddr)
+	    || (lro_desc->iph->daddr != iph->daddr)
+	    || (lro_desc->tcph->source != tcph->source)
+	    || (lro_desc->tcph->dest != tcph->dest))
+		return -1;
+	return 0;
+}
+
+static struct net_lro_desc *lro_get_desc(struct net_lro_mgr *lro_mgr,
+					 struct net_lro_desc *lro_arr,
+					 struct iphdr *iph,
+					 struct tcphdr *tcph)
+{
+	struct net_lro_desc *lro_desc = NULL;
+	struct net_lro_desc *tmp;
+	int max_desc = lro_mgr->max_desc;
+	int i;
+
+	for (i = 0; i < max_desc; i++) {
+		tmp = &lro_arr[i];
+		if (tmp->active)
+			if (!lro_check_tcp_conn(tmp, iph, tcph)) {
+				lro_desc = tmp;
+				goto out;
+			}
+	}
+
+	for (i = 0; i < max_desc; i++) {
+		if (!lro_arr[i].active) {
+			lro_desc = &lro_arr[i];
+			goto out;
+		}
+	}
+
+	LRO_INC_STATS(lro_mgr, no_desc);
+out:
+	return lro_desc;
+}
+
+static void lro_flush(struct net_lro_mgr *lro_mgr,
+		      struct net_lro_desc *lro_desc)
+{
+	if (lro_desc->pkt_aggr_cnt > 1)
+		lro_update_tcp_ip_header(lro_desc);
+
+	skb_shinfo(lro_desc->parent)->gso_size = lro_desc->mss;
+
+	if (lro_desc->vgrp) {
+		if (lro_mgr->features & LRO_F_NAPI)
+			vlan_hwaccel_receive_skb(lro_desc->parent,
+						 lro_desc->vgrp,
+						 lro_desc->vlan_tag);
+		else
+			vlan_hwaccel_rx(lro_desc->parent,
+					lro_desc->vgrp,
+					lro_desc->vlan_tag);
+
+	} else {
+		if (lro_mgr->features & LRO_F_NAPI)
+			netif_receive_skb(lro_desc->parent);
+		else
+			netif_rx(lro_desc->parent);
+	}
+
+	LRO_INC_STATS(lro_mgr, flushed);
+	lro_clear_desc(lro_desc);
+}
+
+static int __lro_proc_skb(struct net_lro_mgr *lro_mgr, struct sk_buff *skb,
+			  struct vlan_group *vgrp, u16 vlan_tag, void *priv)
+{
+	struct net_lro_desc *lro_desc;
+	struct iphdr *iph;
+	struct tcphdr *tcph;
+	u64 flags;
+	int vlan_hdr_len = 0;
+
+	if (!lro_mgr->get_skb_header
+	    || lro_mgr->get_skb_header(skb, (void *)&iph, (void *)&tcph,
+				       &flags, priv))
+		goto out;
+
+	if (!(flags & LRO_IPV4) || !(flags & LRO_TCP))
+		goto out;
+
+	lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
+	if (!lro_desc)
+		goto out;
+
+	if ((skb->protocol == htons(ETH_P_8021Q))
+	    && !(lro_mgr->features & LRO_F_EXTRACT_VLAN_ID))
+		vlan_hdr_len = VLAN_HLEN;
+
+	if (!lro_desc->active) { /* start new lro session */
+		if (lro_tcp_ip_check(iph, tcph, skb->len - vlan_hdr_len, NULL))
+			goto out;
+
+		skb->ip_summed = lro_mgr->ip_summed_aggr;
+		lro_init_desc(lro_desc, skb, iph, tcph, vlan_tag, vgrp);
+		LRO_INC_STATS(lro_mgr, aggregated);
+		return 0;
+	}
+
+	if (lro_desc->tcp_next_seq != ntohl(tcph->seq))
+		goto out2;
+
+	if (lro_tcp_ip_check(iph, tcph, skb->len, lro_desc))
+		goto out2;
+
+	lro_add_packet(lro_desc, skb, iph, tcph);
+	LRO_INC_STATS(lro_mgr, aggregated);
+
+	if ((lro_desc->pkt_aggr_cnt >= lro_mgr->max_aggr) ||
+	    lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu))
+		lro_flush(lro_mgr, lro_desc);
+
+	return 0;
+
+out2: /* send aggregated SKBs to stack */
+	lro_flush(lro_mgr, lro_desc);
+
+out:
+	return 1;
+}
+
+
+static struct sk_buff *lro_gen_skb(struct net_lro_mgr *lro_mgr,
+				   struct skb_frag_struct *frags,
+				   int len, int true_size,
+				   void *mac_hdr,
+				   int hlen, __wsum sum,
+				   u32 ip_summed)
+{
+	struct sk_buff *skb;
+	struct skb_frag_struct *skb_frags;
+	int data_len = len;
+	int hdr_len = min(len, hlen);
+
+	skb = netdev_alloc_skb(lro_mgr->dev, hlen + lro_mgr->frag_align_pad);
+	if (!skb)
+		return NULL;
+
+	skb_reserve(skb, lro_mgr->frag_align_pad);
+	skb->len = len;
+	skb->data_len = len - hdr_len;
+	skb->truesize += true_size;
+	skb->tail += hdr_len;
+
+	memcpy(skb->data, mac_hdr, hdr_len);
+
+	skb_frags = skb_shinfo(skb)->frags;
+	while (data_len > 0) {
+		*skb_frags = *frags;
+		data_len -= frags->size;
+		skb_frags++;
+		frags++;
+		skb_shinfo(skb)->nr_frags++;
+	}
+
+	skb_shinfo(skb)->frags[0].page_offset += hdr_len;
+	skb_shinfo(skb)->frags[0].size -= hdr_len;
+
+	skb->ip_summed = ip_summed;
+	skb->csum = sum;
+	skb->protocol = eth_type_trans(skb, lro_mgr->dev);
+	return skb;
+}
+
+static struct sk_buff *__lro_proc_segment(struct net_lro_mgr *lro_mgr,
+					  struct skb_frag_struct *frags,
+					  int len, int true_size,
+					  struct vlan_group *vgrp,
+					  u16 vlan_tag, void *priv, __wsum sum)
+{
+	struct net_lro_desc *lro_desc;
+	struct iphdr *iph;
+	struct tcphdr *tcph;
+	struct sk_buff *skb;
+	u64 flags;
+	void *mac_hdr;
+	int mac_hdr_len;
+	int hdr_len = LRO_MAX_PG_HLEN;
+	int vlan_hdr_len = 0;
+
+	if (!lro_mgr->get_frag_header
+	    || lro_mgr->get_frag_header(frags, (void *)&mac_hdr, (void *)&iph,
+					(void *)&tcph, &flags, priv)) {
+		mac_hdr = page_address(frags->page) + frags->page_offset;
+		goto out1;
+	}
+
+	if (!(flags & LRO_IPV4) || !(flags & LRO_TCP))
+		goto out1;
+
+	hdr_len = (int)((void *)(tcph) + TCP_HDR_LEN(tcph) - mac_hdr);
+	mac_hdr_len = (int)((void *)(iph) - mac_hdr);
+
+	lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
+	if (!lro_desc)
+		goto out1;
+
+	if (!lro_desc->active) { /* start new lro session */
+		if (lro_tcp_ip_check(iph, tcph, len - mac_hdr_len, NULL))
+			goto out1;
+
+		skb = lro_gen_skb(lro_mgr, frags, len, true_size, mac_hdr,
+				  hdr_len, 0, lro_mgr->ip_summed_aggr);
+		if (!skb)
+			goto out;
+
+		if ((skb->protocol == htons(ETH_P_8021Q))
+		    && !(lro_mgr->features & LRO_F_EXTRACT_VLAN_ID))
+			vlan_hdr_len = VLAN_HLEN;
+
+		iph = (void *)(skb->data + vlan_hdr_len);
+		tcph = (void *)((u8 *)skb->data + vlan_hdr_len
+				+ IP_HDR_LEN(iph));
+
+		lro_init_desc(lro_desc, skb, iph, tcph, 0, NULL);
+		LRO_INC_STATS(lro_mgr, aggregated);
+		return NULL;
+	}
+
+	if (lro_desc->tcp_next_seq != ntohl(tcph->seq))
+		goto out2;
+
+	if (lro_tcp_ip_check(iph, tcph, len - mac_hdr_len, lro_desc))
+		goto out2;
+
+	lro_add_frags(lro_desc, len, hdr_len, true_size, frags, iph, tcph);
+	LRO_INC_STATS(lro_mgr, aggregated);
+
+	if ((skb_shinfo(lro_desc->parent)->nr_frags >= lro_mgr->max_aggr) ||
+	    lro_desc->parent->len > (0xFFFF - lro_mgr->dev->mtu))
+		lro_flush(lro_mgr, lro_desc);
+
+	return NULL;
+
+out2: /* send aggregated packets to the stack */
+	lro_flush(lro_mgr, lro_desc);
+
+out1:  /* Original packet has to be posted to the stack */
+	skb = lro_gen_skb(lro_mgr, frags, len, true_size, mac_hdr,
+			  hdr_len, sum, lro_mgr->ip_summed);
+out:
+	return skb;
+}
+
+void lro_receive_skb(struct net_lro_mgr *lro_mgr,
+		     struct sk_buff *skb,
+		     void *priv)
+{
+	if (__lro_proc_skb(lro_mgr, skb, NULL, 0, priv)) {
+		if (lro_mgr->features & LRO_F_NAPI)
+			netif_receive_skb(skb);
+		else
+			netif_rx(skb);
+	}
+}
+EXPORT_SYMBOL(lro_receive_skb);
+
+void lro_vlan_hwaccel_receive_skb(struct net_lro_mgr *lro_mgr,
+				  struct sk_buff *skb,
+				  struct vlan_group *vgrp,
+				  u16 vlan_tag,
+				  void *priv)
+{
+	if (__lro_proc_skb(lro_mgr, skb, vgrp, vlan_tag, priv)) {
+		if (lro_mgr->features & LRO_F_NAPI)
+			vlan_hwaccel_receive_skb(skb, vgrp, vlan_tag);
+		else
+			vlan_hwaccel_rx(skb, vgrp, vlan_tag);
+	}
+}
+EXPORT_SYMBOL(lro_vlan_hwaccel_receive_skb);
+
+void lro_receive_frags(struct net_lro_mgr *lro_mgr,
+		       struct skb_frag_struct *frags,
+		       int len, int true_size, void *priv, __wsum sum)
+{
+	struct sk_buff *skb;
+
+	skb = __lro_proc_segment(lro_mgr, frags, len, true_size, NULL, 0,
+				 priv, sum);
+	if (!skb)
+		return;
+
+	if (lro_mgr->features & LRO_F_NAPI)
+		netif_receive_skb(skb);
+	else
+		netif_rx(skb);
+}
+EXPORT_SYMBOL(lro_receive_frags);
+
+void lro_vlan_hwaccel_receive_frags(struct net_lro_mgr *lro_mgr,
+				    struct skb_frag_struct *frags,
+				    int len, int true_size,
+				    struct vlan_group *vgrp,
+				    u16 vlan_tag, void *priv, __wsum sum)
+{
+	struct sk_buff *skb;
+
+	skb = __lro_proc_segment(lro_mgr, frags, len, true_size, vgrp,
+				 vlan_tag, priv, sum);
+	if (!skb)
+		return;
+
+	if (lro_mgr->features & LRO_F_NAPI)
+		vlan_hwaccel_receive_skb(skb, vgrp, vlan_tag);
+	else
+		vlan_hwaccel_rx(skb, vgrp, vlan_tag);
+}
+EXPORT_SYMBOL(lro_vlan_hwaccel_receive_frags);
+
+void lro_flush_all(struct net_lro_mgr *lro_mgr)
+{
+	int i;
+	struct net_lro_desc *lro_desc = lro_mgr->lro_arr;
+
+	for (i = 0; i < lro_mgr->max_desc; i++) {
+		if (lro_desc[i].active)
+			lro_flush(lro_mgr, &lro_desc[i]);
+	}
+}
+EXPORT_SYMBOL(lro_flush_all);
+
+void lro_flush_pkt(struct net_lro_mgr *lro_mgr,
+		  struct iphdr *iph, struct tcphdr *tcph)
+{
+	struct net_lro_desc *lro_desc;
+
+	lro_desc = lro_get_desc(lro_mgr, lro_mgr->lro_arr, iph, tcph);
+	if (lro_desc->active)
+		lro_flush(lro_mgr, lro_desc);
+}
+EXPORT_SYMBOL(lro_flush_pkt);
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
new file mode 100644
index 0000000..1c5fd38
--- /dev/null
+++ b/net/ipv4/inet_timewait_sock.c
@@ -0,0 +1,447 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Generic TIME_WAIT sockets functions
+ *
+ *		From code orinally in TCP
+ */
+
+#include <linux/kernel.h>
+#include <net/inet_hashtables.h>
+#include <net/inet_timewait_sock.h>
+#include <net/ip.h>
+
+/* Must be called with locally disabled BHs. */
+static void __inet_twsk_kill(struct inet_timewait_sock *tw,
+			     struct inet_hashinfo *hashinfo)
+{
+	struct inet_bind_hashbucket *bhead;
+	struct inet_bind_bucket *tb;
+	/* Unlink from established hashes. */
+	rwlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);
+
+	write_lock(lock);
+	if (hlist_unhashed(&tw->tw_node)) {
+		write_unlock(lock);
+		return;
+	}
+	__hlist_del(&tw->tw_node);
+	sk_node_init(&tw->tw_node);
+	write_unlock(lock);
+
+	/* Disassociate with bind bucket. */
+	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num,
+			hashinfo->bhash_size)];
+	spin_lock(&bhead->lock);
+	tb = tw->tw_tb;
+	__hlist_del(&tw->tw_bind_node);
+	tw->tw_tb = NULL;
+	inet_bind_bucket_destroy(hashinfo->bind_bucket_cachep, tb);
+	spin_unlock(&bhead->lock);
+#ifdef SOCK_REFCNT_DEBUG
+	if (atomic_read(&tw->tw_refcnt) != 1) {
+		printk(KERN_DEBUG "%s timewait_sock %p refcnt=%d\n",
+		       tw->tw_prot->name, tw, atomic_read(&tw->tw_refcnt));
+	}
+#endif
+	inet_twsk_put(tw);
+}
+
+void inet_twsk_put(struct inet_timewait_sock *tw)
+{
+	if (atomic_dec_and_test(&tw->tw_refcnt)) {
+		struct module *owner = tw->tw_prot->owner;
+		twsk_destructor((struct sock *)tw);
+#ifdef SOCK_REFCNT_DEBUG
+		printk(KERN_DEBUG "%s timewait_sock %p released\n",
+		       tw->tw_prot->name, tw);
+#endif
+		release_net(twsk_net(tw));
+		kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);
+		module_put(owner);
+	}
+}
+EXPORT_SYMBOL_GPL(inet_twsk_put);
+
+/*
+ * Enter the time wait state. This is called with locally disabled BH.
+ * Essentially we whip up a timewait bucket, copy the relevant info into it
+ * from the SK, and mess with hash chains and list linkage.
+ */
+void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
+			   struct inet_hashinfo *hashinfo)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash);
+	rwlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
+	struct inet_bind_hashbucket *bhead;
+	/* Step 1: Put TW into bind hash. Original socket stays there too.
+	   Note, that any socket with inet->num != 0 MUST be bound in
+	   binding cache, even if it is closed.
+	 */
+	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->num,
+			hashinfo->bhash_size)];
+	spin_lock(&bhead->lock);
+	tw->tw_tb = icsk->icsk_bind_hash;
+	WARN_ON(!icsk->icsk_bind_hash);
+	inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
+	spin_unlock(&bhead->lock);
+
+	write_lock(lock);
+
+	/* Step 2: Remove SK from established hash. */
+	if (__sk_del_node_init(sk))
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+
+	/* Step 3: Hash TW into TIMEWAIT chain. */
+	inet_twsk_add_node(tw, &ehead->twchain);
+	atomic_inc(&tw->tw_refcnt);
+
+	write_unlock(lock);
+}
+
+EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
+
+struct inet_timewait_sock *inet_twsk_alloc(const struct sock *sk, const int state)
+{
+	struct inet_timewait_sock *tw =
+		kmem_cache_alloc(sk->sk_prot_creator->twsk_prot->twsk_slab,
+				 GFP_ATOMIC);
+	if (tw != NULL) {
+		const struct inet_sock *inet = inet_sk(sk);
+
+		/* Give us an identity. */
+		tw->tw_daddr	    = inet->daddr;
+		tw->tw_rcv_saddr    = inet->rcv_saddr;
+		tw->tw_bound_dev_if = sk->sk_bound_dev_if;
+		tw->tw_num	    = inet->num;
+		tw->tw_state	    = TCP_TIME_WAIT;
+		tw->tw_substate	    = state;
+		tw->tw_sport	    = inet->sport;
+		tw->tw_dport	    = inet->dport;
+		tw->tw_family	    = sk->sk_family;
+		tw->tw_reuse	    = sk->sk_reuse;
+		tw->tw_hash	    = sk->sk_hash;
+		tw->tw_ipv6only	    = 0;
+		tw->tw_transparent  = inet->transparent;
+		tw->tw_prot	    = sk->sk_prot_creator;
+		twsk_net_set(tw, hold_net(sock_net(sk)));
+		atomic_set(&tw->tw_refcnt, 1);
+		inet_twsk_dead_node_init(tw);
+		__module_get(tw->tw_prot->owner);
+	}
+
+	return tw;
+}
+
+EXPORT_SYMBOL_GPL(inet_twsk_alloc);
+
+/* Returns non-zero if quota exceeded.  */
+static int inet_twdr_do_twkill_work(struct inet_timewait_death_row *twdr,
+				    const int slot)
+{
+	struct inet_timewait_sock *tw;
+	struct hlist_node *node;
+	unsigned int killed;
+	int ret;
+
+	/* NOTE: compare this to previous version where lock
+	 * was released after detaching chain. It was racy,
+	 * because tw buckets are scheduled in not serialized context
+	 * in 2.3 (with netfilter), and with softnet it is common, because
+	 * soft irqs are not sequenced.
+	 */
+	killed = 0;
+	ret = 0;
+rescan:
+	inet_twsk_for_each_inmate(tw, node, &twdr->cells[slot]) {
+		__inet_twsk_del_dead_node(tw);
+		spin_unlock(&twdr->death_lock);
+		__inet_twsk_kill(tw, twdr->hashinfo);
+#ifdef CONFIG_NET_NS
+		NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITED);
+#endif
+		inet_twsk_put(tw);
+		killed++;
+		spin_lock(&twdr->death_lock);
+		if (killed > INET_TWDR_TWKILL_QUOTA) {
+			ret = 1;
+			break;
+		}
+
+		/* While we dropped twdr->death_lock, another cpu may have
+		 * killed off the next TW bucket in the list, therefore
+		 * do a fresh re-read of the hlist head node with the
+		 * lock reacquired.  We still use the hlist traversal
+		 * macro in order to get the prefetches.
+		 */
+		goto rescan;
+	}
+
+	twdr->tw_count -= killed;
+#ifndef CONFIG_NET_NS
+	NET_ADD_STATS_BH(&init_net, LINUX_MIB_TIMEWAITED, killed);
+#endif
+	return ret;
+}
+
+void inet_twdr_hangman(unsigned long data)
+{
+	struct inet_timewait_death_row *twdr;
+	int unsigned need_timer;
+
+	twdr = (struct inet_timewait_death_row *)data;
+	spin_lock(&twdr->death_lock);
+
+	if (twdr->tw_count == 0)
+		goto out;
+
+	need_timer = 0;
+	if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
+		twdr->thread_slots |= (1 << twdr->slot);
+		schedule_work(&twdr->twkill_work);
+		need_timer = 1;
+	} else {
+		/* We purged the entire slot, anything left?  */
+		if (twdr->tw_count)
+			need_timer = 1;
+	}
+	twdr->slot = ((twdr->slot + 1) & (INET_TWDR_TWKILL_SLOTS - 1));
+	if (need_timer)
+		mod_timer(&twdr->tw_timer, jiffies + twdr->period);
+out:
+	spin_unlock(&twdr->death_lock);
+}
+
+EXPORT_SYMBOL_GPL(inet_twdr_hangman);
+
+void inet_twdr_twkill_work(struct work_struct *work)
+{
+	struct inet_timewait_death_row *twdr =
+		container_of(work, struct inet_timewait_death_row, twkill_work);
+	int i;
+
+	BUILD_BUG_ON((INET_TWDR_TWKILL_SLOTS - 1) >
+			(sizeof(twdr->thread_slots) * 8));
+
+	while (twdr->thread_slots) {
+		spin_lock_bh(&twdr->death_lock);
+		for (i = 0; i < INET_TWDR_TWKILL_SLOTS; i++) {
+			if (!(twdr->thread_slots & (1 << i)))
+				continue;
+
+			while (inet_twdr_do_twkill_work(twdr, i) != 0) {
+				if (need_resched()) {
+					spin_unlock_bh(&twdr->death_lock);
+					schedule();
+					spin_lock_bh(&twdr->death_lock);
+				}
+			}
+
+			twdr->thread_slots &= ~(1 << i);
+		}
+		spin_unlock_bh(&twdr->death_lock);
+	}
+}
+
+EXPORT_SYMBOL_GPL(inet_twdr_twkill_work);
+
+/* These are always called from BH context.  See callers in
+ * tcp_input.c to verify this.
+ */
+
+/* This is for handling early-kills of TIME_WAIT sockets. */
+void inet_twsk_deschedule(struct inet_timewait_sock *tw,
+			  struct inet_timewait_death_row *twdr)
+{
+	spin_lock(&twdr->death_lock);
+	if (inet_twsk_del_dead_node(tw)) {
+		inet_twsk_put(tw);
+		if (--twdr->tw_count == 0)
+			del_timer(&twdr->tw_timer);
+	}
+	spin_unlock(&twdr->death_lock);
+	__inet_twsk_kill(tw, twdr->hashinfo);
+}
+
+EXPORT_SYMBOL(inet_twsk_deschedule);
+
+void inet_twsk_schedule(struct inet_timewait_sock *tw,
+		       struct inet_timewait_death_row *twdr,
+		       const int timeo, const int timewait_len)
+{
+	struct hlist_head *list;
+	int slot;
+
+	/* timeout := RTO * 3.5
+	 *
+	 * 3.5 = 1+2+0.5 to wait for two retransmits.
+	 *
+	 * RATIONALE: if FIN arrived and we entered TIME-WAIT state,
+	 * our ACK acking that FIN can be lost. If N subsequent retransmitted
+	 * FINs (or previous seqments) are lost (probability of such event
+	 * is p^(N+1), where p is probability to lose single packet and
+	 * time to detect the loss is about RTO*(2^N - 1) with exponential
+	 * backoff). Normal timewait length is calculated so, that we
+	 * waited at least for one retransmitted FIN (maximal RTO is 120sec).
+	 * [ BTW Linux. following BSD, violates this requirement waiting
+	 *   only for 60sec, we should wait at least for 240 secs.
+	 *   Well, 240 consumes too much of resources 8)
+	 * ]
+	 * This interval is not reduced to catch old duplicate and
+	 * responces to our wandering segments living for two MSLs.
+	 * However, if we use PAWS to detect
+	 * old duplicates, we can reduce the interval to bounds required
+	 * by RTO, rather than MSL. So, if peer understands PAWS, we
+	 * kill tw bucket after 3.5*RTO (it is important that this number
+	 * is greater than TS tick!) and detect old duplicates with help
+	 * of PAWS.
+	 */
+	slot = (timeo + (1 << INET_TWDR_RECYCLE_TICK) - 1) >> INET_TWDR_RECYCLE_TICK;
+
+	spin_lock(&twdr->death_lock);
+
+	/* Unlink it, if it was scheduled */
+	if (inet_twsk_del_dead_node(tw))
+		twdr->tw_count--;
+	else
+		atomic_inc(&tw->tw_refcnt);
+
+	if (slot >= INET_TWDR_RECYCLE_SLOTS) {
+		/* Schedule to slow timer */
+		if (timeo >= timewait_len) {
+			slot = INET_TWDR_TWKILL_SLOTS - 1;
+		} else {
+			slot = DIV_ROUND_UP(timeo, twdr->period);
+			if (slot >= INET_TWDR_TWKILL_SLOTS)
+				slot = INET_TWDR_TWKILL_SLOTS - 1;
+		}
+		tw->tw_ttd = jiffies + timeo;
+		slot = (twdr->slot + slot) & (INET_TWDR_TWKILL_SLOTS - 1);
+		list = &twdr->cells[slot];
+	} else {
+		tw->tw_ttd = jiffies + (slot << INET_TWDR_RECYCLE_TICK);
+
+		if (twdr->twcal_hand < 0) {
+			twdr->twcal_hand = 0;
+			twdr->twcal_jiffie = jiffies;
+			twdr->twcal_timer.expires = twdr->twcal_jiffie +
+					      (slot << INET_TWDR_RECYCLE_TICK);
+			add_timer(&twdr->twcal_timer);
+		} else {
+			if (time_after(twdr->twcal_timer.expires,
+				       jiffies + (slot << INET_TWDR_RECYCLE_TICK)))
+				mod_timer(&twdr->twcal_timer,
+					  jiffies + (slot << INET_TWDR_RECYCLE_TICK));
+			slot = (twdr->twcal_hand + slot) & (INET_TWDR_RECYCLE_SLOTS - 1);
+		}
+		list = &twdr->twcal_row[slot];
+	}
+
+	hlist_add_head(&tw->tw_death_node, list);
+
+	if (twdr->tw_count++ == 0)
+		mod_timer(&twdr->tw_timer, jiffies + twdr->period);
+	spin_unlock(&twdr->death_lock);
+}
+
+EXPORT_SYMBOL_GPL(inet_twsk_schedule);
+
+void inet_twdr_twcal_tick(unsigned long data)
+{
+	struct inet_timewait_death_row *twdr;
+	int n, slot;
+	unsigned long j;
+	unsigned long now = jiffies;
+	int killed = 0;
+	int adv = 0;
+
+	twdr = (struct inet_timewait_death_row *)data;
+
+	spin_lock(&twdr->death_lock);
+	if (twdr->twcal_hand < 0)
+		goto out;
+
+	slot = twdr->twcal_hand;
+	j = twdr->twcal_jiffie;
+
+	for (n = 0; n < INET_TWDR_RECYCLE_SLOTS; n++) {
+		if (time_before_eq(j, now)) {
+			struct hlist_node *node, *safe;
+			struct inet_timewait_sock *tw;
+
+			inet_twsk_for_each_inmate_safe(tw, node, safe,
+						       &twdr->twcal_row[slot]) {
+				__inet_twsk_del_dead_node(tw);
+				__inet_twsk_kill(tw, twdr->hashinfo);
+#ifdef CONFIG_NET_NS
+				NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_TIMEWAITKILLED);
+#endif
+				inet_twsk_put(tw);
+				killed++;
+			}
+		} else {
+			if (!adv) {
+				adv = 1;
+				twdr->twcal_jiffie = j;
+				twdr->twcal_hand = slot;
+			}
+
+			if (!hlist_empty(&twdr->twcal_row[slot])) {
+				mod_timer(&twdr->twcal_timer, j);
+				goto out;
+			}
+		}
+		j += 1 << INET_TWDR_RECYCLE_TICK;
+		slot = (slot + 1) & (INET_TWDR_RECYCLE_SLOTS - 1);
+	}
+	twdr->twcal_hand = -1;
+
+out:
+	if ((twdr->tw_count -= killed) == 0)
+		del_timer(&twdr->tw_timer);
+#ifndef CONFIG_NET_NS
+	NET_ADD_STATS_BH(&init_net, LINUX_MIB_TIMEWAITKILLED, killed);
+#endif
+	spin_unlock(&twdr->death_lock);
+}
+
+EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick);
+
+void inet_twsk_purge(struct net *net, struct inet_hashinfo *hashinfo,
+		     struct inet_timewait_death_row *twdr, int family)
+{
+	struct inet_timewait_sock *tw;
+	struct sock *sk;
+	struct hlist_node *node;
+	int h;
+
+	local_bh_disable();
+	for (h = 0; h < (hashinfo->ehash_size); h++) {
+		struct inet_ehash_bucket *head =
+			inet_ehash_bucket(hashinfo, h);
+		rwlock_t *lock = inet_ehash_lockp(hashinfo, h);
+restart:
+		write_lock(lock);
+		sk_for_each(sk, node, &head->twchain) {
+
+			tw = inet_twsk(sk);
+			if (!net_eq(twsk_net(tw), net) ||
+			    tw->tw_family != family)
+				continue;
+
+			atomic_inc(&tw->tw_refcnt);
+			write_unlock(lock);
+			inet_twsk_deschedule(tw, twdr);
+			inet_twsk_put(tw);
+
+			goto restart;
+		}
+		write_unlock(lock);
+	}
+	local_bh_enable();
+}
+EXPORT_SYMBOL_GPL(inet_twsk_purge);
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
new file mode 100644
index 0000000..a456cee
--- /dev/null
+++ b/net/ipv4/inetpeer.c
@@ -0,0 +1,463 @@
+/*
+ *		INETPEER - A storage for permanent information about peers
+ *
+ *  This source is covered by the GNU GPL, the same as all kernel sources.
+ *
+ *  Authors:	Andrey V. Savochkin <saw@msu.ru>
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/random.h>
+#include <linux/timer.h>
+#include <linux/time.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/net.h>
+#include <net/ip.h>
+#include <net/inetpeer.h>
+
+/*
+ *  Theory of operations.
+ *  We keep one entry for each peer IP address.  The nodes contains long-living
+ *  information about the peer which doesn't depend on routes.
+ *  At this moment this information consists only of ID field for the next
+ *  outgoing IP packet.  This field is incremented with each packet as encoded
+ *  in inet_getid() function (include/net/inetpeer.h).
+ *  At the moment of writing this notes identifier of IP packets is generated
+ *  to be unpredictable using this code only for packets subjected
+ *  (actually or potentially) to defragmentation.  I.e. DF packets less than
+ *  PMTU in size uses a constant ID and do not use this code (see
+ *  ip_select_ident() in include/net/ip.h).
+ *
+ *  Route cache entries hold references to our nodes.
+ *  New cache entries get references via lookup by destination IP address in
+ *  the avl tree.  The reference is grabbed only when it's needed i.e. only
+ *  when we try to output IP packet which needs an unpredictable ID (see
+ *  __ip_select_ident() in net/ipv4/route.c).
+ *  Nodes are removed only when reference counter goes to 0.
+ *  When it's happened the node may be removed when a sufficient amount of
+ *  time has been passed since its last use.  The less-recently-used entry can
+ *  also be removed if the pool is overloaded i.e. if the total amount of
+ *  entries is greater-or-equal than the threshold.
+ *
+ *  Node pool is organised as an AVL tree.
+ *  Such an implementation has been chosen not just for fun.  It's a way to
+ *  prevent easy and efficient DoS attacks by creating hash collisions.  A huge
+ *  amount of long living nodes in a single hash slot would significantly delay
+ *  lookups performed with disabled BHs.
+ *
+ *  Serialisation issues.
+ *  1.  Nodes may appear in the tree only with the pool write lock held.
+ *  2.  Nodes may disappear from the tree only with the pool write lock held
+ *      AND reference count being 0.
+ *  3.  Nodes appears and disappears from unused node list only under
+ *      "inet_peer_unused_lock".
+ *  4.  Global variable peer_total is modified under the pool lock.
+ *  5.  struct inet_peer fields modification:
+ *		avl_left, avl_right, avl_parent, avl_height: pool lock
+ *		unused: unused node list lock
+ *		refcnt: atomically against modifications on other CPU;
+ *		   usually under some other lock to prevent node disappearing
+ *		dtime: unused node list lock
+ *		v4daddr: unchangeable
+ *		ip_id_count: idlock
+ */
+
+/* Exported for inet_getid inline function.  */
+DEFINE_SPINLOCK(inet_peer_idlock);
+
+static struct kmem_cache *peer_cachep __read_mostly;
+
+#define node_height(x) x->avl_height
+static struct inet_peer peer_fake_node = {
+	.avl_left	= &peer_fake_node,
+	.avl_right	= &peer_fake_node,
+	.avl_height	= 0
+};
+#define peer_avl_empty (&peer_fake_node)
+static struct inet_peer *peer_root = peer_avl_empty;
+static DEFINE_RWLOCK(peer_pool_lock);
+#define PEER_MAXDEPTH 40 /* sufficient for about 2^27 nodes */
+
+static int peer_total;
+/* Exported for sysctl_net_ipv4.  */
+int inet_peer_threshold __read_mostly = 65536 + 128;	/* start to throw entries more
+					 * aggressively at this stage */
+int inet_peer_minttl __read_mostly = 120 * HZ;	/* TTL under high load: 120 sec */
+int inet_peer_maxttl __read_mostly = 10 * 60 * HZ;	/* usual time to live: 10 min */
+int inet_peer_gc_mintime __read_mostly = 10 * HZ;
+int inet_peer_gc_maxtime __read_mostly = 120 * HZ;
+
+static LIST_HEAD(unused_peers);
+static DEFINE_SPINLOCK(inet_peer_unused_lock);
+
+static void peer_check_expire(unsigned long dummy);
+static DEFINE_TIMER(peer_periodic_timer, peer_check_expire, 0, 0);
+
+
+/* Called from ip_output.c:ip_init  */
+void __init inet_initpeers(void)
+{
+	struct sysinfo si;
+
+	/* Use the straight interface to information about memory. */
+	si_meminfo(&si);
+	/* The values below were suggested by Alexey Kuznetsov
+	 * <kuznet@ms2.inr.ac.ru>.  I don't have any opinion about the values
+	 * myself.  --SAW
+	 */
+	if (si.totalram <= (32768*1024)/PAGE_SIZE)
+		inet_peer_threshold >>= 1; /* max pool size about 1MB on IA32 */
+	if (si.totalram <= (16384*1024)/PAGE_SIZE)
+		inet_peer_threshold >>= 1; /* about 512KB */
+	if (si.totalram <= (8192*1024)/PAGE_SIZE)
+		inet_peer_threshold >>= 2; /* about 128KB */
+
+	peer_cachep = kmem_cache_create("inet_peer_cache",
+			sizeof(struct inet_peer),
+			0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
+			NULL);
+
+	/* All the timers, started at system startup tend
+	   to synchronize. Perturb it a bit.
+	 */
+	peer_periodic_timer.expires = jiffies
+		+ net_random() % inet_peer_gc_maxtime
+		+ inet_peer_gc_maxtime;
+	add_timer(&peer_periodic_timer);
+}
+
+/* Called with or without local BH being disabled. */
+static void unlink_from_unused(struct inet_peer *p)
+{
+	spin_lock_bh(&inet_peer_unused_lock);
+	list_del_init(&p->unused);
+	spin_unlock_bh(&inet_peer_unused_lock);
+}
+
+/*
+ * Called with local BH disabled and the pool lock held.
+ * _stack is known to be NULL or not at compile time,
+ * so compiler will optimize the if (_stack) tests.
+ */
+#define lookup(_daddr,_stack) 					\
+({								\
+	struct inet_peer *u, **v;				\
+	if (_stack != NULL) {					\
+		stackptr = _stack;				\
+		*stackptr++ = &peer_root;			\
+	}							\
+	for (u = peer_root; u != peer_avl_empty; ) {		\
+		if (_daddr == u->v4daddr)			\
+			break;					\
+		if ((__force __u32)_daddr < (__force __u32)u->v4daddr)	\
+			v = &u->avl_left;			\
+		else						\
+			v = &u->avl_right;			\
+		if (_stack != NULL)				\
+			*stackptr++ = v;			\
+		u = *v;						\
+	}							\
+	u;							\
+})
+
+/* Called with local BH disabled and the pool write lock held. */
+#define lookup_rightempty(start)				\
+({								\
+	struct inet_peer *u, **v;				\
+	*stackptr++ = &start->avl_left;				\
+	v = &start->avl_left;					\
+	for (u = *v; u->avl_right != peer_avl_empty; ) {	\
+		v = &u->avl_right;				\
+		*stackptr++ = v;				\
+		u = *v;						\
+	}							\
+	u;							\
+})
+
+/* Called with local BH disabled and the pool write lock held.
+ * Variable names are the proof of operation correctness.
+ * Look into mm/map_avl.c for more detail description of the ideas.  */
+static void peer_avl_rebalance(struct inet_peer **stack[],
+		struct inet_peer ***stackend)
+{
+	struct inet_peer **nodep, *node, *l, *r;
+	int lh, rh;
+
+	while (stackend > stack) {
+		nodep = *--stackend;
+		node = *nodep;
+		l = node->avl_left;
+		r = node->avl_right;
+		lh = node_height(l);
+		rh = node_height(r);
+		if (lh > rh + 1) { /* l: RH+2 */
+			struct inet_peer *ll, *lr, *lrl, *lrr;
+			int lrh;
+			ll = l->avl_left;
+			lr = l->avl_right;
+			lrh = node_height(lr);
+			if (lrh <= node_height(ll)) {	/* ll: RH+1 */
+				node->avl_left = lr;	/* lr: RH or RH+1 */
+				node->avl_right = r;	/* r: RH */
+				node->avl_height = lrh + 1; /* RH+1 or RH+2 */
+				l->avl_left = ll;	/* ll: RH+1 */
+				l->avl_right = node;	/* node: RH+1 or RH+2 */
+				l->avl_height = node->avl_height + 1;
+				*nodep = l;
+			} else { /* ll: RH, lr: RH+1 */
+				lrl = lr->avl_left;	/* lrl: RH or RH-1 */
+				lrr = lr->avl_right;	/* lrr: RH or RH-1 */
+				node->avl_left = lrr;	/* lrr: RH or RH-1 */
+				node->avl_right = r;	/* r: RH */
+				node->avl_height = rh + 1; /* node: RH+1 */
+				l->avl_left = ll;	/* ll: RH */
+				l->avl_right = lrl;	/* lrl: RH or RH-1 */
+				l->avl_height = rh + 1;	/* l: RH+1 */
+				lr->avl_left = l;	/* l: RH+1 */
+				lr->avl_right = node;	/* node: RH+1 */
+				lr->avl_height = rh + 2;
+				*nodep = lr;
+			}
+		} else if (rh > lh + 1) { /* r: LH+2 */
+			struct inet_peer *rr, *rl, *rlr, *rll;
+			int rlh;
+			rr = r->avl_right;
+			rl = r->avl_left;
+			rlh = node_height(rl);
+			if (rlh <= node_height(rr)) {	/* rr: LH+1 */
+				node->avl_right = rl;	/* rl: LH or LH+1 */
+				node->avl_left = l;	/* l: LH */
+				node->avl_height = rlh + 1; /* LH+1 or LH+2 */
+				r->avl_right = rr;	/* rr: LH+1 */
+				r->avl_left = node;	/* node: LH+1 or LH+2 */
+				r->avl_height = node->avl_height + 1;
+				*nodep = r;
+			} else { /* rr: RH, rl: RH+1 */
+				rlr = rl->avl_right;	/* rlr: LH or LH-1 */
+				rll = rl->avl_left;	/* rll: LH or LH-1 */
+				node->avl_right = rll;	/* rll: LH or LH-1 */
+				node->avl_left = l;	/* l: LH */
+				node->avl_height = lh + 1; /* node: LH+1 */
+				r->avl_right = rr;	/* rr: LH */
+				r->avl_left = rlr;	/* rlr: LH or LH-1 */
+				r->avl_height = lh + 1;	/* r: LH+1 */
+				rl->avl_right = r;	/* r: LH+1 */
+				rl->avl_left = node;	/* node: LH+1 */
+				rl->avl_height = lh + 2;
+				*nodep = rl;
+			}
+		} else {
+			node->avl_height = (lh > rh ? lh : rh) + 1;
+		}
+	}
+}
+
+/* Called with local BH disabled and the pool write lock held. */
+#define link_to_pool(n)						\
+do {								\
+	n->avl_height = 1;					\
+	n->avl_left = peer_avl_empty;				\
+	n->avl_right = peer_avl_empty;				\
+	**--stackptr = n;					\
+	peer_avl_rebalance(stack, stackptr);			\
+} while(0)
+
+/* May be called with local BH enabled. */
+static void unlink_from_pool(struct inet_peer *p)
+{
+	int do_free;
+
+	do_free = 0;
+
+	write_lock_bh(&peer_pool_lock);
+	/* Check the reference counter.  It was artificially incremented by 1
+	 * in cleanup() function to prevent sudden disappearing.  If the
+	 * reference count is still 1 then the node is referenced only as `p'
+	 * here and from the pool.  So under the exclusive pool lock it's safe
+	 * to remove the node and free it later. */
+	if (atomic_read(&p->refcnt) == 1) {
+		struct inet_peer **stack[PEER_MAXDEPTH];
+		struct inet_peer ***stackptr, ***delp;
+		if (lookup(p->v4daddr, stack) != p)
+			BUG();
+		delp = stackptr - 1; /* *delp[0] == p */
+		if (p->avl_left == peer_avl_empty) {
+			*delp[0] = p->avl_right;
+			--stackptr;
+		} else {
+			/* look for a node to insert instead of p */
+			struct inet_peer *t;
+			t = lookup_rightempty(p);
+			BUG_ON(*stackptr[-1] != t);
+			**--stackptr = t->avl_left;
+			/* t is removed, t->v4daddr > x->v4daddr for any
+			 * x in p->avl_left subtree.
+			 * Put t in the old place of p. */
+			*delp[0] = t;
+			t->avl_left = p->avl_left;
+			t->avl_right = p->avl_right;
+			t->avl_height = p->avl_height;
+			BUG_ON(delp[1] != &p->avl_left);
+			delp[1] = &t->avl_left; /* was &p->avl_left */
+		}
+		peer_avl_rebalance(stack, stackptr);
+		peer_total--;
+		do_free = 1;
+	}
+	write_unlock_bh(&peer_pool_lock);
+
+	if (do_free)
+		kmem_cache_free(peer_cachep, p);
+	else
+		/* The node is used again.  Decrease the reference counter
+		 * back.  The loop "cleanup -> unlink_from_unused
+		 *   -> unlink_from_pool -> putpeer -> link_to_unused
+		 *   -> cleanup (for the same node)"
+		 * doesn't really exist because the entry will have a
+		 * recent deletion time and will not be cleaned again soon. */
+		inet_putpeer(p);
+}
+
+/* May be called with local BH enabled. */
+static int cleanup_once(unsigned long ttl)
+{
+	struct inet_peer *p = NULL;
+
+	/* Remove the first entry from the list of unused nodes. */
+	spin_lock_bh(&inet_peer_unused_lock);
+	if (!list_empty(&unused_peers)) {
+		__u32 delta;
+
+		p = list_first_entry(&unused_peers, struct inet_peer, unused);
+		delta = (__u32)jiffies - p->dtime;
+
+		if (delta < ttl) {
+			/* Do not prune fresh entries. */
+			spin_unlock_bh(&inet_peer_unused_lock);
+			return -1;
+		}
+
+		list_del_init(&p->unused);
+
+		/* Grab an extra reference to prevent node disappearing
+		 * before unlink_from_pool() call. */
+		atomic_inc(&p->refcnt);
+	}
+	spin_unlock_bh(&inet_peer_unused_lock);
+
+	if (p == NULL)
+		/* It means that the total number of USED entries has
+		 * grown over inet_peer_threshold.  It shouldn't really
+		 * happen because of entry limits in route cache. */
+		return -1;
+
+	unlink_from_pool(p);
+	return 0;
+}
+
+/* Called with or without local BH being disabled. */
+struct inet_peer *inet_getpeer(__be32 daddr, int create)
+{
+	struct inet_peer *p, *n;
+	struct inet_peer **stack[PEER_MAXDEPTH], ***stackptr;
+
+	/* Look up for the address quickly. */
+	read_lock_bh(&peer_pool_lock);
+	p = lookup(daddr, NULL);
+	if (p != peer_avl_empty)
+		atomic_inc(&p->refcnt);
+	read_unlock_bh(&peer_pool_lock);
+
+	if (p != peer_avl_empty) {
+		/* The existing node has been found. */
+		/* Remove the entry from unused list if it was there. */
+		unlink_from_unused(p);
+		return p;
+	}
+
+	if (!create)
+		return NULL;
+
+	/* Allocate the space outside the locked region. */
+	n = kmem_cache_alloc(peer_cachep, GFP_ATOMIC);
+	if (n == NULL)
+		return NULL;
+	n->v4daddr = daddr;
+	atomic_set(&n->refcnt, 1);
+	atomic_set(&n->rid, 0);
+	n->ip_id_count = secure_ip_id(daddr);
+	n->tcp_ts_stamp = 0;
+
+	write_lock_bh(&peer_pool_lock);
+	/* Check if an entry has suddenly appeared. */
+	p = lookup(daddr, stack);
+	if (p != peer_avl_empty)
+		goto out_free;
+
+	/* Link the node. */
+	link_to_pool(n);
+	INIT_LIST_HEAD(&n->unused);
+	peer_total++;
+	write_unlock_bh(&peer_pool_lock);
+
+	if (peer_total >= inet_peer_threshold)
+		/* Remove one less-recently-used entry. */
+		cleanup_once(0);
+
+	return n;
+
+out_free:
+	/* The appropriate node is already in the pool. */
+	atomic_inc(&p->refcnt);
+	write_unlock_bh(&peer_pool_lock);
+	/* Remove the entry from unused list if it was there. */
+	unlink_from_unused(p);
+	/* Free preallocated the preallocated node. */
+	kmem_cache_free(peer_cachep, n);
+	return p;
+}
+
+/* Called with local BH disabled. */
+static void peer_check_expire(unsigned long dummy)
+{
+	unsigned long now = jiffies;
+	int ttl;
+
+	if (peer_total >= inet_peer_threshold)
+		ttl = inet_peer_minttl;
+	else
+		ttl = inet_peer_maxttl
+				- (inet_peer_maxttl - inet_peer_minttl) / HZ *
+					peer_total / inet_peer_threshold * HZ;
+	while (!cleanup_once(ttl)) {
+		if (jiffies != now)
+			break;
+	}
+
+	/* Trigger the timer after inet_peer_gc_mintime .. inet_peer_gc_maxtime
+	 * interval depending on the total number of entries (more entries,
+	 * less interval). */
+	if (peer_total >= inet_peer_threshold)
+		peer_periodic_timer.expires = jiffies + inet_peer_gc_mintime;
+	else
+		peer_periodic_timer.expires = jiffies
+			+ inet_peer_gc_maxtime
+			- (inet_peer_gc_maxtime - inet_peer_gc_mintime) / HZ *
+				peer_total / inet_peer_threshold * HZ;
+	add_timer(&peer_periodic_timer);
+}
+
+void inet_putpeer(struct inet_peer *p)
+{
+	spin_lock_bh(&inet_peer_unused_lock);
+	if (atomic_dec_and_test(&p->refcnt)) {
+		list_add_tail(&p->unused, &unused_peers);
+		p->dtime = (__u32)jiffies;
+	}
+	spin_unlock_bh(&inet_peer_unused_lock);
+}
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
new file mode 100644
index 0000000..450016b
--- /dev/null
+++ b/net/ipv4/ip_forward.c
@@ -0,0 +1,131 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The IP forwarding functionality.
+ *
+ * Authors:	see ip.c
+ *
+ * Fixes:
+ *		Many		:	Split from ip.c , see ip_input.c for
+ *					history.
+ *		Dave Gregorich	:	NULL ip_rt_put fix for multicast
+ *					routing.
+ *		Jos Vos		:	Add call_out_firewall before sending,
+ *					use output device for accounting.
+ *		Jos Vos		:	Call forward firewall after routing
+ *					(always use output device).
+ *		Mike McLagan	:	Routing by source
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <linux/netdevice.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/icmp.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/checksum.h>
+#include <linux/route.h>
+#include <net/route.h>
+#include <net/xfrm.h>
+
+static int ip_forward_finish(struct sk_buff *skb)
+{
+	struct ip_options * opt	= &(IPCB(skb)->opt);
+
+	IP_INC_STATS_BH(dev_net(skb->dst->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
+
+	if (unlikely(opt->optlen))
+		ip_forward_options(skb);
+
+	return dst_output(skb);
+}
+
+int ip_forward(struct sk_buff *skb)
+{
+	struct iphdr *iph;	/* Our header */
+	struct rtable *rt;	/* Route we use */
+	struct ip_options * opt	= &(IPCB(skb)->opt);
+
+	if (skb_warn_if_lro(skb))
+		goto drop;
+
+	if (!xfrm4_policy_check(NULL, XFRM_POLICY_FWD, skb))
+		goto drop;
+
+	if (IPCB(skb)->opt.router_alert && ip_call_ra_chain(skb))
+		return NET_RX_SUCCESS;
+
+	if (skb->pkt_type != PACKET_HOST)
+		goto drop;
+
+	skb_forward_csum(skb);
+
+	/*
+	 *	According to the RFC, we must first decrease the TTL field. If
+	 *	that reaches zero, we must reply an ICMP control message telling
+	 *	that the packet's lifetime expired.
+	 */
+	if (ip_hdr(skb)->ttl <= 1)
+		goto too_many_hops;
+
+	if (!xfrm4_route_forward(skb))
+		goto drop;
+
+	rt = skb->rtable;
+
+	if (opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+		goto sr_failed;
+
+	if (unlikely(skb->len > dst_mtu(&rt->u.dst) && !skb_is_gso(skb) &&
+		     (ip_hdr(skb)->frag_off & htons(IP_DF))) && !skb->local_df) {
+		IP_INC_STATS(dev_net(rt->u.dst.dev), IPSTATS_MIB_FRAGFAILS);
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+			  htonl(dst_mtu(&rt->u.dst)));
+		goto drop;
+	}
+
+	/* We are about to mangle packet. Copy it! */
+	if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+rt->u.dst.header_len))
+		goto drop;
+	iph = ip_hdr(skb);
+
+	/* Decrease ttl after skb cow done */
+	ip_decrease_ttl(iph);
+
+	/*
+	 *	We now generate an ICMP HOST REDIRECT giving the route
+	 *	we calculated.
+	 */
+	if (rt->rt_flags&RTCF_DOREDIRECT && !opt->srr && !skb->sp)
+		ip_rt_send_redirect(skb);
+
+	skb->priority = rt_tos2priority(iph->tos);
+
+	return NF_HOOK(PF_INET, NF_INET_FORWARD, skb, skb->dev, rt->u.dst.dev,
+		       ip_forward_finish);
+
+sr_failed:
+	/*
+	 *	Strict routing permits no gatewaying
+	 */
+	 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_SR_FAILED, 0);
+	 goto drop;
+
+too_many_hops:
+	/* Tell the sender its packet died... */
+	IP_INC_STATS_BH(dev_net(skb->dst->dev), IPSTATS_MIB_INHDRERRORS);
+	icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0);
+drop:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
new file mode 100644
index 0000000..e4f81f5
--- /dev/null
+++ b/net/ipv4/ip_fragment.c
@@ -0,0 +1,760 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The IP fragmentation functionality.
+ *
+ * Authors:	Fred N. van Kempen <waltje@uWalt.NL.Mugnet.ORG>
+ *		Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ * Fixes:
+ *		Alan Cox	:	Split from ip.c , see ip_input.c for history.
+ *		David S. Miller :	Begin massive cleanup...
+ *		Andi Kleen	:	Add sysctls.
+ *		xxxx		:	Overlapfrag bug.
+ *		Ultima          :       ip_expire() kernel panic.
+ *		Bill Hawes	:	Frag accounting and evictor fixes.
+ *		John McDonald	:	0 length frag bug.
+ *		Alexey Kuznetsov:	SMP races, threading, cleanup.
+ *		Patrick McHardy :	LRU queue of frag heads for evictor.
+ */
+
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/jiffies.h>
+#include <linux/skbuff.h>
+#include <linux/list.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <linux/netdevice.h>
+#include <linux/jhash.h>
+#include <linux/random.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/checksum.h>
+#include <net/inetpeer.h>
+#include <net/inet_frag.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/inet.h>
+#include <linux/netfilter_ipv4.h>
+
+/* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
+ * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
+ * as well. Or notify me, at least. --ANK
+ */
+
+static int sysctl_ipfrag_max_dist __read_mostly = 64;
+
+struct ipfrag_skb_cb
+{
+	struct inet_skb_parm	h;
+	int			offset;
+};
+
+#define FRAG_CB(skb)	((struct ipfrag_skb_cb*)((skb)->cb))
+
+/* Describe an entry in the "incomplete datagrams" queue. */
+struct ipq {
+	struct inet_frag_queue q;
+
+	u32		user;
+	__be32		saddr;
+	__be32		daddr;
+	__be16		id;
+	u8		protocol;
+	int             iif;
+	unsigned int    rid;
+	struct inet_peer *peer;
+};
+
+static struct inet_frags ip4_frags;
+
+int ip_frag_nqueues(struct net *net)
+{
+	return net->ipv4.frags.nqueues;
+}
+
+int ip_frag_mem(struct net *net)
+{
+	return atomic_read(&net->ipv4.frags.mem);
+}
+
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+			 struct net_device *dev);
+
+struct ip4_create_arg {
+	struct iphdr *iph;
+	u32 user;
+};
+
+static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
+{
+	return jhash_3words((__force u32)id << 16 | prot,
+			    (__force u32)saddr, (__force u32)daddr,
+			    ip4_frags.rnd) & (INETFRAGS_HASHSZ - 1);
+}
+
+static unsigned int ip4_hashfn(struct inet_frag_queue *q)
+{
+	struct ipq *ipq;
+
+	ipq = container_of(q, struct ipq, q);
+	return ipqhashfn(ipq->id, ipq->saddr, ipq->daddr, ipq->protocol);
+}
+
+static int ip4_frag_match(struct inet_frag_queue *q, void *a)
+{
+	struct ipq *qp;
+	struct ip4_create_arg *arg = a;
+
+	qp = container_of(q, struct ipq, q);
+	return (qp->id == arg->iph->id &&
+			qp->saddr == arg->iph->saddr &&
+			qp->daddr == arg->iph->daddr &&
+			qp->protocol == arg->iph->protocol &&
+			qp->user == arg->user);
+}
+
+/* Memory Tracking Functions. */
+static __inline__ void frag_kfree_skb(struct netns_frags *nf,
+		struct sk_buff *skb, int *work)
+{
+	if (work)
+		*work -= skb->truesize;
+	atomic_sub(skb->truesize, &nf->mem);
+	kfree_skb(skb);
+}
+
+static void ip4_frag_init(struct inet_frag_queue *q, void *a)
+{
+	struct ipq *qp = container_of(q, struct ipq, q);
+	struct ip4_create_arg *arg = a;
+
+	qp->protocol = arg->iph->protocol;
+	qp->id = arg->iph->id;
+	qp->saddr = arg->iph->saddr;
+	qp->daddr = arg->iph->daddr;
+	qp->user = arg->user;
+	qp->peer = sysctl_ipfrag_max_dist ?
+		inet_getpeer(arg->iph->saddr, 1) : NULL;
+}
+
+static __inline__ void ip4_frag_free(struct inet_frag_queue *q)
+{
+	struct ipq *qp;
+
+	qp = container_of(q, struct ipq, q);
+	if (qp->peer)
+		inet_putpeer(qp->peer);
+}
+
+
+/* Destruction primitives. */
+
+static __inline__ void ipq_put(struct ipq *ipq)
+{
+	inet_frag_put(&ipq->q, &ip4_frags);
+}
+
+/* Kill ipq entry. It is not destroyed immediately,
+ * because caller (and someone more) holds reference count.
+ */
+static void ipq_kill(struct ipq *ipq)
+{
+	inet_frag_kill(&ipq->q, &ip4_frags);
+}
+
+/* Memory limiting on fragments.  Evictor trashes the oldest
+ * fragment queue until we are back under the threshold.
+ */
+static void ip_evictor(struct net *net)
+{
+	int evicted;
+
+	evicted = inet_frag_evictor(&net->ipv4.frags, &ip4_frags);
+	if (evicted)
+		IP_ADD_STATS_BH(net, IPSTATS_MIB_REASMFAILS, evicted);
+}
+
+/*
+ * Oops, a fragment queue timed out.  Kill it and send an ICMP reply.
+ */
+static void ip_expire(unsigned long arg)
+{
+	struct ipq *qp;
+	struct net *net;
+
+	qp = container_of((struct inet_frag_queue *) arg, struct ipq, q);
+	net = container_of(qp->q.net, struct net, ipv4.frags);
+
+	spin_lock(&qp->q.lock);
+
+	if (qp->q.last_in & INET_FRAG_COMPLETE)
+		goto out;
+
+	ipq_kill(qp);
+
+	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMTIMEOUT);
+	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
+
+	if ((qp->q.last_in & INET_FRAG_FIRST_IN) && qp->q.fragments != NULL) {
+		struct sk_buff *head = qp->q.fragments;
+
+		/* Send an ICMP "Fragment Reassembly Timeout" message. */
+		if ((head->dev = dev_get_by_index(net, qp->iif)) != NULL) {
+			icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
+			dev_put(head->dev);
+		}
+	}
+out:
+	spin_unlock(&qp->q.lock);
+	ipq_put(qp);
+}
+
+/* Find the correct entry in the "incomplete datagrams" queue for
+ * this IP datagram, and create new one, if nothing is found.
+ */
+static inline struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
+{
+	struct inet_frag_queue *q;
+	struct ip4_create_arg arg;
+	unsigned int hash;
+
+	arg.iph = iph;
+	arg.user = user;
+
+	read_lock(&ip4_frags.lock);
+	hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
+
+	q = inet_frag_find(&net->ipv4.frags, &ip4_frags, &arg, hash);
+	if (q == NULL)
+		goto out_nomem;
+
+	return container_of(q, struct ipq, q);
+
+out_nomem:
+	LIMIT_NETDEBUG(KERN_ERR "ip_frag_create: no memory left !\n");
+	return NULL;
+}
+
+/* Is the fragment too far ahead to be part of ipq? */
+static inline int ip_frag_too_far(struct ipq *qp)
+{
+	struct inet_peer *peer = qp->peer;
+	unsigned int max = sysctl_ipfrag_max_dist;
+	unsigned int start, end;
+
+	int rc;
+
+	if (!peer || !max)
+		return 0;
+
+	start = qp->rid;
+	end = atomic_inc_return(&peer->rid);
+	qp->rid = end;
+
+	rc = qp->q.fragments && (end - start) > max;
+
+	if (rc) {
+		struct net *net;
+
+		net = container_of(qp->q.net, struct net, ipv4.frags);
+		IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
+	}
+
+	return rc;
+}
+
+static int ip_frag_reinit(struct ipq *qp)
+{
+	struct sk_buff *fp;
+
+	if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
+		atomic_inc(&qp->q.refcnt);
+		return -ETIMEDOUT;
+	}
+
+	fp = qp->q.fragments;
+	do {
+		struct sk_buff *xp = fp->next;
+		frag_kfree_skb(qp->q.net, fp, NULL);
+		fp = xp;
+	} while (fp);
+
+	qp->q.last_in = 0;
+	qp->q.len = 0;
+	qp->q.meat = 0;
+	qp->q.fragments = NULL;
+	qp->iif = 0;
+
+	return 0;
+}
+
+/* Add new segment to existing queue. */
+static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
+{
+	struct sk_buff *prev, *next;
+	struct net_device *dev;
+	int flags, offset;
+	int ihl, end;
+	int err = -ENOENT;
+
+	if (qp->q.last_in & INET_FRAG_COMPLETE)
+		goto err;
+
+	if (!(IPCB(skb)->flags & IPSKB_FRAG_COMPLETE) &&
+	    unlikely(ip_frag_too_far(qp)) &&
+	    unlikely(err = ip_frag_reinit(qp))) {
+		ipq_kill(qp);
+		goto err;
+	}
+
+	offset = ntohs(ip_hdr(skb)->frag_off);
+	flags = offset & ~IP_OFFSET;
+	offset &= IP_OFFSET;
+	offset <<= 3;		/* offset is in 8-byte chunks */
+	ihl = ip_hdrlen(skb);
+
+	/* Determine the position of this fragment. */
+	end = offset + skb->len - ihl;
+	err = -EINVAL;
+
+	/* Is this the final fragment? */
+	if ((flags & IP_MF) == 0) {
+		/* If we already have some bits beyond end
+		 * or have different end, the segment is corrrupted.
+		 */
+		if (end < qp->q.len ||
+		    ((qp->q.last_in & INET_FRAG_LAST_IN) && end != qp->q.len))
+			goto err;
+		qp->q.last_in |= INET_FRAG_LAST_IN;
+		qp->q.len = end;
+	} else {
+		if (end&7) {
+			end &= ~7;
+			if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+				skb->ip_summed = CHECKSUM_NONE;
+		}
+		if (end > qp->q.len) {
+			/* Some bits beyond end -> corruption. */
+			if (qp->q.last_in & INET_FRAG_LAST_IN)
+				goto err;
+			qp->q.len = end;
+		}
+	}
+	if (end == offset)
+		goto err;
+
+	err = -ENOMEM;
+	if (pskb_pull(skb, ihl) == NULL)
+		goto err;
+
+	err = pskb_trim_rcsum(skb, end - offset);
+	if (err)
+		goto err;
+
+	/* Find out which fragments are in front and at the back of us
+	 * in the chain of fragments so far.  We must know where to put
+	 * this fragment, right?
+	 */
+	prev = NULL;
+	for (next = qp->q.fragments; next != NULL; next = next->next) {
+		if (FRAG_CB(next)->offset >= offset)
+			break;	/* bingo! */
+		prev = next;
+	}
+
+	/* We found where to put this one.  Check for overlap with
+	 * preceding fragment, and, if needed, align things so that
+	 * any overlaps are eliminated.
+	 */
+	if (prev) {
+		int i = (FRAG_CB(prev)->offset + prev->len) - offset;
+
+		if (i > 0) {
+			offset += i;
+			err = -EINVAL;
+			if (end <= offset)
+				goto err;
+			err = -ENOMEM;
+			if (!pskb_pull(skb, i))
+				goto err;
+			if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+				skb->ip_summed = CHECKSUM_NONE;
+		}
+	}
+
+	err = -ENOMEM;
+
+	while (next && FRAG_CB(next)->offset < end) {
+		int i = end - FRAG_CB(next)->offset; /* overlap is 'i' bytes */
+
+		if (i < next->len) {
+			/* Eat head of the next overlapped fragment
+			 * and leave the loop. The next ones cannot overlap.
+			 */
+			if (!pskb_pull(next, i))
+				goto err;
+			FRAG_CB(next)->offset += i;
+			qp->q.meat -= i;
+			if (next->ip_summed != CHECKSUM_UNNECESSARY)
+				next->ip_summed = CHECKSUM_NONE;
+			break;
+		} else {
+			struct sk_buff *free_it = next;
+
+			/* Old fragment is completely overridden with
+			 * new one drop it.
+			 */
+			next = next->next;
+
+			if (prev)
+				prev->next = next;
+			else
+				qp->q.fragments = next;
+
+			qp->q.meat -= free_it->len;
+			frag_kfree_skb(qp->q.net, free_it, NULL);
+		}
+	}
+
+	FRAG_CB(skb)->offset = offset;
+
+	/* Insert this fragment in the chain of fragments. */
+	skb->next = next;
+	if (prev)
+		prev->next = skb;
+	else
+		qp->q.fragments = skb;
+
+	dev = skb->dev;
+	if (dev) {
+		qp->iif = dev->ifindex;
+		skb->dev = NULL;
+	}
+	qp->q.stamp = skb->tstamp;
+	qp->q.meat += skb->len;
+	atomic_add(skb->truesize, &qp->q.net->mem);
+	if (offset == 0)
+		qp->q.last_in |= INET_FRAG_FIRST_IN;
+
+	if (qp->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
+	    qp->q.meat == qp->q.len)
+		return ip_frag_reasm(qp, prev, dev);
+
+	write_lock(&ip4_frags.lock);
+	list_move_tail(&qp->q.lru_list, &qp->q.net->lru_list);
+	write_unlock(&ip4_frags.lock);
+	return -EINPROGRESS;
+
+err:
+	kfree_skb(skb);
+	return err;
+}
+
+
+/* Build a new IP datagram from all its fragments. */
+
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+			 struct net_device *dev)
+{
+	struct iphdr *iph;
+	struct sk_buff *fp, *head = qp->q.fragments;
+	int len;
+	int ihlen;
+	int err;
+
+	ipq_kill(qp);
+
+	/* Make the one we just received the head. */
+	if (prev) {
+		head = prev->next;
+		fp = skb_clone(head, GFP_ATOMIC);
+		if (!fp)
+			goto out_nomem;
+
+		fp->next = head->next;
+		prev->next = fp;
+
+		skb_morph(head, qp->q.fragments);
+		head->next = qp->q.fragments->next;
+
+		kfree_skb(qp->q.fragments);
+		qp->q.fragments = head;
+	}
+
+	WARN_ON(head == NULL);
+	WARN_ON(FRAG_CB(head)->offset != 0);
+
+	/* Allocate a new buffer for the datagram. */
+	ihlen = ip_hdrlen(head);
+	len = ihlen + qp->q.len;
+
+	err = -E2BIG;
+	if (len > 65535)
+		goto out_oversize;
+
+	/* Head of list must not be cloned. */
+	if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+		goto out_nomem;
+
+	/* If the first fragment is fragmented itself, we split
+	 * it to two chunks: the first with data and paged part
+	 * and the second, holding only fragments. */
+	if (skb_shinfo(head)->frag_list) {
+		struct sk_buff *clone;
+		int i, plen = 0;
+
+		if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
+			goto out_nomem;
+		clone->next = head->next;
+		head->next = clone;
+		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+		skb_shinfo(head)->frag_list = NULL;
+		for (i=0; i<skb_shinfo(head)->nr_frags; i++)
+			plen += skb_shinfo(head)->frags[i].size;
+		clone->len = clone->data_len = head->data_len - plen;
+		head->data_len -= clone->len;
+		head->len -= clone->len;
+		clone->csum = 0;
+		clone->ip_summed = head->ip_summed;
+		atomic_add(clone->truesize, &qp->q.net->mem);
+	}
+
+	skb_shinfo(head)->frag_list = head->next;
+	skb_push(head, head->data - skb_network_header(head));
+	atomic_sub(head->truesize, &qp->q.net->mem);
+
+	for (fp=head->next; fp; fp = fp->next) {
+		head->data_len += fp->len;
+		head->len += fp->len;
+		if (head->ip_summed != fp->ip_summed)
+			head->ip_summed = CHECKSUM_NONE;
+		else if (head->ip_summed == CHECKSUM_COMPLETE)
+			head->csum = csum_add(head->csum, fp->csum);
+		head->truesize += fp->truesize;
+		atomic_sub(fp->truesize, &qp->q.net->mem);
+	}
+
+	head->next = NULL;
+	head->dev = dev;
+	head->tstamp = qp->q.stamp;
+
+	iph = ip_hdr(head);
+	iph->frag_off = 0;
+	iph->tot_len = htons(len);
+	IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_REASMOKS);
+	qp->q.fragments = NULL;
+	return 0;
+
+out_nomem:
+	LIMIT_NETDEBUG(KERN_ERR "IP: queue_glue: no memory for gluing "
+			      "queue %p\n", qp);
+	err = -ENOMEM;
+	goto out_fail;
+out_oversize:
+	if (net_ratelimit())
+		printk(KERN_INFO
+			"Oversized IP packet from " NIPQUAD_FMT ".\n",
+			NIPQUAD(qp->saddr));
+out_fail:
+	IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_REASMFAILS);
+	return err;
+}
+
+/* Process an incoming IP datagram fragment. */
+int ip_defrag(struct sk_buff *skb, u32 user)
+{
+	struct ipq *qp;
+	struct net *net;
+
+	net = skb->dev ? dev_net(skb->dev) : dev_net(skb->dst->dev);
+	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
+
+	/* Start by cleaning up the memory. */
+	if (atomic_read(&net->ipv4.frags.mem) > net->ipv4.frags.high_thresh)
+		ip_evictor(net);
+
+	/* Lookup (or create) queue header */
+	if ((qp = ip_find(net, ip_hdr(skb), user)) != NULL) {
+		int ret;
+
+		spin_lock(&qp->q.lock);
+
+		ret = ip_frag_queue(qp, skb);
+
+		spin_unlock(&qp->q.lock);
+		ipq_put(qp);
+		return ret;
+	}
+
+	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS);
+	kfree_skb(skb);
+	return -ENOMEM;
+}
+
+#ifdef CONFIG_SYSCTL
+static int zero;
+
+static struct ctl_table ip4_frags_ns_ctl_table[] = {
+	{
+		.ctl_name	= NET_IPV4_IPFRAG_HIGH_THRESH,
+		.procname	= "ipfrag_high_thresh",
+		.data		= &init_net.ipv4.frags.high_thresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_IPFRAG_LOW_THRESH,
+		.procname	= "ipfrag_low_thresh",
+		.data		= &init_net.ipv4.frags.low_thresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_IPFRAG_TIME,
+		.procname	= "ipfrag_time",
+		.data		= &init_net.ipv4.frags.timeout,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{ }
+};
+
+static struct ctl_table ip4_frags_ctl_table[] = {
+	{
+		.ctl_name	= NET_IPV4_IPFRAG_SECRET_INTERVAL,
+		.procname	= "ipfrag_secret_interval",
+		.data		= &ip4_frags.secret_interval,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.procname	= "ipfrag_max_dist",
+		.data		= &sysctl_ipfrag_max_dist,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= &zero
+	},
+	{ }
+};
+
+static int ip4_frags_ns_ctl_register(struct net *net)
+{
+	struct ctl_table *table;
+	struct ctl_table_header *hdr;
+
+	table = ip4_frags_ns_ctl_table;
+	if (net != &init_net) {
+		table = kmemdup(table, sizeof(ip4_frags_ns_ctl_table), GFP_KERNEL);
+		if (table == NULL)
+			goto err_alloc;
+
+		table[0].data = &net->ipv4.frags.high_thresh;
+		table[1].data = &net->ipv4.frags.low_thresh;
+		table[2].data = &net->ipv4.frags.timeout;
+	}
+
+	hdr = register_net_sysctl_table(net, net_ipv4_ctl_path, table);
+	if (hdr == NULL)
+		goto err_reg;
+
+	net->ipv4.frags_hdr = hdr;
+	return 0;
+
+err_reg:
+	if (net != &init_net)
+		kfree(table);
+err_alloc:
+	return -ENOMEM;
+}
+
+static void ip4_frags_ns_ctl_unregister(struct net *net)
+{
+	struct ctl_table *table;
+
+	table = net->ipv4.frags_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->ipv4.frags_hdr);
+	kfree(table);
+}
+
+static void ip4_frags_ctl_register(void)
+{
+	register_net_sysctl_rotable(net_ipv4_ctl_path, ip4_frags_ctl_table);
+}
+#else
+static inline int ip4_frags_ns_ctl_register(struct net *net)
+{
+	return 0;
+}
+
+static inline void ip4_frags_ns_ctl_unregister(struct net *net)
+{
+}
+
+static inline void ip4_frags_ctl_register(void)
+{
+}
+#endif
+
+static int ipv4_frags_init_net(struct net *net)
+{
+	/*
+	 * Fragment cache limits. We will commit 256K at one time. Should we
+	 * cross that limit we will prune down to 192K. This should cope with
+	 * even the most extreme cases without allowing an attacker to
+	 * measurably harm machine performance.
+	 */
+	net->ipv4.frags.high_thresh = 256 * 1024;
+	net->ipv4.frags.low_thresh = 192 * 1024;
+	/*
+	 * Important NOTE! Fragment queue must be destroyed before MSL expires.
+	 * RFC791 is wrong proposing to prolongate timer each fragment arrival
+	 * by TTL.
+	 */
+	net->ipv4.frags.timeout = IP_FRAG_TIME;
+
+	inet_frags_init_net(&net->ipv4.frags);
+
+	return ip4_frags_ns_ctl_register(net);
+}
+
+static void ipv4_frags_exit_net(struct net *net)
+{
+	ip4_frags_ns_ctl_unregister(net);
+	inet_frags_exit_net(&net->ipv4.frags, &ip4_frags);
+}
+
+static struct pernet_operations ip4_frags_ops = {
+	.init = ipv4_frags_init_net,
+	.exit = ipv4_frags_exit_net,
+};
+
+void __init ipfrag_init(void)
+{
+	ip4_frags_ctl_register();
+	register_pernet_subsys(&ip4_frags_ops);
+	ip4_frags.hashfn = ip4_hashfn;
+	ip4_frags.constructor = ip4_frag_init;
+	ip4_frags.destructor = ip4_frag_free;
+	ip4_frags.skb_free = NULL;
+	ip4_frags.qsize = sizeof(struct ipq);
+	ip4_frags.match = ip4_frag_match;
+	ip4_frags.frag_expire = ip_expire;
+	ip4_frags.secret_interval = 10 * 60 * HZ;
+	inet_frags_init(&ip4_frags);
+}
+
+EXPORT_SYMBOL(ip_defrag);
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
new file mode 100644
index 0000000..85c487b
--- /dev/null
+++ b/net/ipv4/ip_gre.c
@@ -0,0 +1,1647 @@
+/*
+ *	Linux NET3:	GRE over IP protocol decoder.
+ *
+ *	Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <linux/in6.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/ipip.h>
+#include <net/arp.h>
+#include <net/checksum.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
+
+#ifdef CONFIG_IPV6
+#include <net/ipv6.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#endif
+
+/*
+   Problems & solutions
+   --------------------
+
+   1. The most important issue is detecting local dead loops.
+   They would cause complete host lockup in transmit, which
+   would be "resolved" by stack overflow or, if queueing is enabled,
+   with infinite looping in net_bh.
+
+   We cannot track such dead loops during route installation,
+   it is infeasible task. The most general solutions would be
+   to keep skb->encapsulation counter (sort of local ttl),
+   and silently drop packet when it expires. It is the best
+   solution, but it supposes maintaing new variable in ALL
+   skb, even if no tunneling is used.
+
+   Current solution: t->recursion lock breaks dead loops. It looks
+   like dev->tbusy flag, but I preferred new variable, because
+   the semantics is different. One day, when hard_start_xmit
+   will be multithreaded we will have to use skb->encapsulation.
+
+
+
+   2. Networking dead loops would not kill routers, but would really
+   kill network. IP hop limit plays role of "t->recursion" in this case,
+   if we copy it from packet being encapsulated to upper header.
+   It is very good solution, but it introduces two problems:
+
+   - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
+     do not work over tunnels.
+   - traceroute does not work. I planned to relay ICMP from tunnel,
+     so that this problem would be solved and traceroute output
+     would even more informative. This idea appeared to be wrong:
+     only Linux complies to rfc1812 now (yes, guys, Linux is the only
+     true router now :-)), all routers (at least, in neighbourhood of mine)
+     return only 8 bytes of payload. It is the end.
+
+   Hence, if we want that OSPF worked or traceroute said something reasonable,
+   we should search for another solution.
+
+   One of them is to parse packet trying to detect inner encapsulation
+   made by our node. It is difficult or even impossible, especially,
+   taking into account fragmentation. TO be short, tt is not solution at all.
+
+   Current solution: The solution was UNEXPECTEDLY SIMPLE.
+   We force DF flag on tunnels with preconfigured hop limit,
+   that is ALL. :-) Well, it does not remove the problem completely,
+   but exponential growth of network traffic is changed to linear
+   (branches, that exceed pmtu are pruned) and tunnel mtu
+   fastly degrades to value <68, where looping stops.
+   Yes, it is not good if there exists a router in the loop,
+   which does not force DF, even when encapsulating packets have DF set.
+   But it is not our problem! Nobody could accuse us, we made
+   all that we could make. Even if it is your gated who injected
+   fatal route to network, even if it were you who configured
+   fatal static route: you are innocent. :-)
+
+
+
+   3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
+   practically identical code. It would be good to glue them
+   together, but it is not very evident, how to make them modular.
+   sit is integral part of IPv6, ipip and gre are naturally modular.
+   We could extract common parts (hash table, ioctl etc)
+   to a separate module (ip_tunnel.c).
+
+   Alexey Kuznetsov.
+ */
+
+static struct rtnl_link_ops ipgre_link_ops __read_mostly;
+static int ipgre_tunnel_init(struct net_device *dev);
+static void ipgre_tunnel_setup(struct net_device *dev);
+static int ipgre_tunnel_bind_dev(struct net_device *dev);
+
+/* Fallback tunnel: no source, no destination, no key, no options */
+
+static int ipgre_fb_tunnel_init(struct net_device *dev);
+
+#define HASH_SIZE  16
+
+static int ipgre_net_id;
+struct ipgre_net {
+	struct ip_tunnel *tunnels[4][HASH_SIZE];
+
+	struct net_device *fb_tunnel_dev;
+};
+
+/* Tunnel hash table */
+
+/*
+   4 hash tables:
+
+   3: (remote,local)
+   2: (remote,*)
+   1: (*,local)
+   0: (*,*)
+
+   We require exact key match i.e. if a key is present in packet
+   it will match only tunnel with the same key; if it is not present,
+   it will match only keyless tunnel.
+
+   All keysless packets, if not matched configured keyless tunnels
+   will match fallback tunnel.
+ */
+
+#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
+
+#define tunnels_r_l	tunnels[3]
+#define tunnels_r	tunnels[2]
+#define tunnels_l	tunnels[1]
+#define tunnels_wc	tunnels[0]
+
+static DEFINE_RWLOCK(ipgre_lock);
+
+/* Given src, dst and key, find appropriate for input tunnel. */
+
+static struct ip_tunnel * ipgre_tunnel_lookup(struct net *net,
+					      __be32 remote, __be32 local,
+					      __be32 key, __be16 gre_proto)
+{
+	unsigned h0 = HASH(remote);
+	unsigned h1 = HASH(key);
+	struct ip_tunnel *t;
+	struct ip_tunnel *t2 = NULL;
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+	int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
+		       ARPHRD_ETHER : ARPHRD_IPGRE;
+
+	for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) {
+		if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) {
+			if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+				if (t->dev->type == dev_type)
+					return t;
+				if (t->dev->type == ARPHRD_IPGRE && !t2)
+					t2 = t;
+			}
+		}
+	}
+
+	for (t = ign->tunnels_r[h0^h1]; t; t = t->next) {
+		if (remote == t->parms.iph.daddr) {
+			if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+				if (t->dev->type == dev_type)
+					return t;
+				if (t->dev->type == ARPHRD_IPGRE && !t2)
+					t2 = t;
+			}
+		}
+	}
+
+	for (t = ign->tunnels_l[h1]; t; t = t->next) {
+		if (local == t->parms.iph.saddr ||
+		     (local == t->parms.iph.daddr &&
+		      ipv4_is_multicast(local))) {
+			if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+				if (t->dev->type == dev_type)
+					return t;
+				if (t->dev->type == ARPHRD_IPGRE && !t2)
+					t2 = t;
+			}
+		}
+	}
+
+	for (t = ign->tunnels_wc[h1]; t; t = t->next) {
+		if (t->parms.i_key == key && t->dev->flags & IFF_UP) {
+			if (t->dev->type == dev_type)
+				return t;
+			if (t->dev->type == ARPHRD_IPGRE && !t2)
+				t2 = t;
+		}
+	}
+
+	if (t2)
+		return t2;
+
+	if (ign->fb_tunnel_dev->flags&IFF_UP)
+		return netdev_priv(ign->fb_tunnel_dev);
+	return NULL;
+}
+
+static struct ip_tunnel **__ipgre_bucket(struct ipgre_net *ign,
+		struct ip_tunnel_parm *parms)
+{
+	__be32 remote = parms->iph.daddr;
+	__be32 local = parms->iph.saddr;
+	__be32 key = parms->i_key;
+	unsigned h = HASH(key);
+	int prio = 0;
+
+	if (local)
+		prio |= 1;
+	if (remote && !ipv4_is_multicast(remote)) {
+		prio |= 2;
+		h ^= HASH(remote);
+	}
+
+	return &ign->tunnels[prio][h];
+}
+
+static inline struct ip_tunnel **ipgre_bucket(struct ipgre_net *ign,
+		struct ip_tunnel *t)
+{
+	return __ipgre_bucket(ign, &t->parms);
+}
+
+static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
+{
+	struct ip_tunnel **tp = ipgre_bucket(ign, t);
+
+	t->next = *tp;
+	write_lock_bh(&ipgre_lock);
+	*tp = t;
+	write_unlock_bh(&ipgre_lock);
+}
+
+static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
+{
+	struct ip_tunnel **tp;
+
+	for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) {
+		if (t == *tp) {
+			write_lock_bh(&ipgre_lock);
+			*tp = t->next;
+			write_unlock_bh(&ipgre_lock);
+			break;
+		}
+	}
+}
+
+static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
+					   struct ip_tunnel_parm *parms,
+					   int type)
+{
+	__be32 remote = parms->iph.daddr;
+	__be32 local = parms->iph.saddr;
+	__be32 key = parms->i_key;
+	struct ip_tunnel *t, **tp;
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+	for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next)
+		if (local == t->parms.iph.saddr &&
+		    remote == t->parms.iph.daddr &&
+		    key == t->parms.i_key &&
+		    type == t->dev->type)
+			break;
+
+	return t;
+}
+
+static struct ip_tunnel * ipgre_tunnel_locate(struct net *net,
+		struct ip_tunnel_parm *parms, int create)
+{
+	struct ip_tunnel *t, *nt;
+	struct net_device *dev;
+	char name[IFNAMSIZ];
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+	t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
+	if (t || !create)
+		return t;
+
+	if (parms->name[0])
+		strlcpy(name, parms->name, IFNAMSIZ);
+	else
+		sprintf(name, "gre%%d");
+
+	dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
+	if (!dev)
+	  return NULL;
+
+	dev_net_set(dev, net);
+
+	if (strchr(name, '%')) {
+		if (dev_alloc_name(dev, name) < 0)
+			goto failed_free;
+	}
+
+	nt = netdev_priv(dev);
+	nt->parms = *parms;
+	dev->rtnl_link_ops = &ipgre_link_ops;
+
+	dev->mtu = ipgre_tunnel_bind_dev(dev);
+
+	if (register_netdevice(dev) < 0)
+		goto failed_free;
+
+	dev_hold(dev);
+	ipgre_tunnel_link(ign, nt);
+	return nt;
+
+failed_free:
+	free_netdev(dev);
+	return NULL;
+}
+
+static void ipgre_tunnel_uninit(struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+	ipgre_tunnel_unlink(ign, netdev_priv(dev));
+	dev_put(dev);
+}
+
+
+static void ipgre_err(struct sk_buff *skb, u32 info)
+{
+
+/* All the routers (except for Linux) return only
+   8 bytes of packet payload. It means, that precise relaying of
+   ICMP in the real Internet is absolutely infeasible.
+
+   Moreover, Cisco "wise men" put GRE key to the third word
+   in GRE header. It makes impossible maintaining even soft state for keyed
+   GRE tunnels with enabled checksum. Tell them "thank you".
+
+   Well, I wonder, rfc1812 was written by Cisco employee,
+   what the hell these idiots break standrads established
+   by themself???
+ */
+
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	__be16	     *p = (__be16*)(skb->data+(iph->ihl<<2));
+	int grehlen = (iph->ihl<<2) + 4;
+	const int type = icmp_hdr(skb)->type;
+	const int code = icmp_hdr(skb)->code;
+	struct ip_tunnel *t;
+	__be16 flags;
+
+	flags = p[0];
+	if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
+		if (flags&(GRE_VERSION|GRE_ROUTING))
+			return;
+		if (flags&GRE_KEY) {
+			grehlen += 4;
+			if (flags&GRE_CSUM)
+				grehlen += 4;
+		}
+	}
+
+	/* If only 8 bytes returned, keyed message will be dropped here */
+	if (skb_headlen(skb) < grehlen)
+		return;
+
+	switch (type) {
+	default:
+	case ICMP_PARAMETERPROB:
+		return;
+
+	case ICMP_DEST_UNREACH:
+		switch (code) {
+		case ICMP_SR_FAILED:
+		case ICMP_PORT_UNREACH:
+			/* Impossible event. */
+			return;
+		case ICMP_FRAG_NEEDED:
+			/* Soft state for pmtu is maintained by IP core. */
+			return;
+		default:
+			/* All others are translated to HOST_UNREACH.
+			   rfc2003 contains "deep thoughts" about NET_UNREACH,
+			   I believe they are just ether pollution. --ANK
+			 */
+			break;
+		}
+		break;
+	case ICMP_TIME_EXCEEDED:
+		if (code != ICMP_EXC_TTL)
+			return;
+		break;
+	}
+
+	read_lock(&ipgre_lock);
+	t = ipgre_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr,
+				flags & GRE_KEY ?
+				*(((__be32 *)p) + (grehlen / 4) - 1) : 0,
+				p[1]);
+	if (t == NULL || t->parms.iph.daddr == 0 ||
+	    ipv4_is_multicast(t->parms.iph.daddr))
+		goto out;
+
+	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+		goto out;
+
+	if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
+		t->err_count++;
+	else
+		t->err_count = 1;
+	t->err_time = jiffies;
+out:
+	read_unlock(&ipgre_lock);
+	return;
+}
+
+static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
+{
+	if (INET_ECN_is_ce(iph->tos)) {
+		if (skb->protocol == htons(ETH_P_IP)) {
+			IP_ECN_set_ce(ip_hdr(skb));
+		} else if (skb->protocol == htons(ETH_P_IPV6)) {
+			IP6_ECN_set_ce(ipv6_hdr(skb));
+		}
+	}
+}
+
+static inline u8
+ipgre_ecn_encapsulate(u8 tos, struct iphdr *old_iph, struct sk_buff *skb)
+{
+	u8 inner = 0;
+	if (skb->protocol == htons(ETH_P_IP))
+		inner = old_iph->tos;
+	else if (skb->protocol == htons(ETH_P_IPV6))
+		inner = ipv6_get_dsfield((struct ipv6hdr *)old_iph);
+	return INET_ECN_encapsulate(tos, inner);
+}
+
+static int ipgre_rcv(struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	u8     *h;
+	__be16    flags;
+	__sum16   csum = 0;
+	__be32 key = 0;
+	u32    seqno = 0;
+	struct ip_tunnel *tunnel;
+	int    offset = 4;
+	__be16 gre_proto;
+	unsigned int len;
+
+	if (!pskb_may_pull(skb, 16))
+		goto drop_nolock;
+
+	iph = ip_hdr(skb);
+	h = skb->data;
+	flags = *(__be16*)h;
+
+	if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
+		/* - Version must be 0.
+		   - We do not support routing headers.
+		 */
+		if (flags&(GRE_VERSION|GRE_ROUTING))
+			goto drop_nolock;
+
+		if (flags&GRE_CSUM) {
+			switch (skb->ip_summed) {
+			case CHECKSUM_COMPLETE:
+				csum = csum_fold(skb->csum);
+				if (!csum)
+					break;
+				/* fall through */
+			case CHECKSUM_NONE:
+				skb->csum = 0;
+				csum = __skb_checksum_complete(skb);
+				skb->ip_summed = CHECKSUM_COMPLETE;
+			}
+			offset += 4;
+		}
+		if (flags&GRE_KEY) {
+			key = *(__be32*)(h + offset);
+			offset += 4;
+		}
+		if (flags&GRE_SEQ) {
+			seqno = ntohl(*(__be32*)(h + offset));
+			offset += 4;
+		}
+	}
+
+	gre_proto = *(__be16 *)(h + 2);
+
+	read_lock(&ipgre_lock);
+	if ((tunnel = ipgre_tunnel_lookup(dev_net(skb->dev),
+					  iph->saddr, iph->daddr, key,
+					  gre_proto))) {
+		struct net_device_stats *stats = &tunnel->dev->stats;
+
+		secpath_reset(skb);
+
+		skb->protocol = gre_proto;
+		/* WCCP version 1 and 2 protocol decoding.
+		 * - Change protocol to IP
+		 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
+		 */
+		if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
+			skb->protocol = htons(ETH_P_IP);
+			if ((*(h + offset) & 0xF0) != 0x40)
+				offset += 4;
+		}
+
+		skb->mac_header = skb->network_header;
+		__pskb_pull(skb, offset);
+		skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
+		skb->pkt_type = PACKET_HOST;
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+		if (ipv4_is_multicast(iph->daddr)) {
+			/* Looped back packet, drop it! */
+			if (skb->rtable->fl.iif == 0)
+				goto drop;
+			stats->multicast++;
+			skb->pkt_type = PACKET_BROADCAST;
+		}
+#endif
+
+		if (((flags&GRE_CSUM) && csum) ||
+		    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
+			stats->rx_crc_errors++;
+			stats->rx_errors++;
+			goto drop;
+		}
+		if (tunnel->parms.i_flags&GRE_SEQ) {
+			if (!(flags&GRE_SEQ) ||
+			    (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
+				stats->rx_fifo_errors++;
+				stats->rx_errors++;
+				goto drop;
+			}
+			tunnel->i_seqno = seqno + 1;
+		}
+
+		len = skb->len;
+
+		/* Warning: All skb pointers will be invalidated! */
+		if (tunnel->dev->type == ARPHRD_ETHER) {
+			if (!pskb_may_pull(skb, ETH_HLEN)) {
+				stats->rx_length_errors++;
+				stats->rx_errors++;
+				goto drop;
+			}
+
+			iph = ip_hdr(skb);
+			skb->protocol = eth_type_trans(skb, tunnel->dev);
+			skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+		}
+
+		stats->rx_packets++;
+		stats->rx_bytes += len;
+		skb->dev = tunnel->dev;
+		dst_release(skb->dst);
+		skb->dst = NULL;
+		nf_reset(skb);
+
+		skb_reset_network_header(skb);
+		ipgre_ecn_decapsulate(iph, skb);
+
+		netif_rx(skb);
+		read_unlock(&ipgre_lock);
+		return(0);
+	}
+	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+drop:
+	read_unlock(&ipgre_lock);
+drop_nolock:
+	kfree_skb(skb);
+	return(0);
+}
+
+static int ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct net_device_stats *stats = &tunnel->dev->stats;
+	struct iphdr  *old_iph = ip_hdr(skb);
+	struct iphdr  *tiph;
+	u8     tos;
+	__be16 df;
+	struct rtable *rt;     			/* Route to the other host */
+	struct net_device *tdev;			/* Device to other host */
+	struct iphdr  *iph;			/* Our new IP header */
+	unsigned int max_headroom;		/* The extra header space needed */
+	int    gre_hlen;
+	__be32 dst;
+	int    mtu;
+
+	if (tunnel->recursion++) {
+		stats->collisions++;
+		goto tx_error;
+	}
+
+	if (dev->type == ARPHRD_ETHER)
+		IPCB(skb)->flags = 0;
+
+	if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
+		gre_hlen = 0;
+		tiph = (struct iphdr*)skb->data;
+	} else {
+		gre_hlen = tunnel->hlen;
+		tiph = &tunnel->parms.iph;
+	}
+
+	if ((dst = tiph->daddr) == 0) {
+		/* NBMA tunnel */
+
+		if (skb->dst == NULL) {
+			stats->tx_fifo_errors++;
+			goto tx_error;
+		}
+
+		if (skb->protocol == htons(ETH_P_IP)) {
+			rt = skb->rtable;
+			if ((dst = rt->rt_gateway) == 0)
+				goto tx_error_icmp;
+		}
+#ifdef CONFIG_IPV6
+		else if (skb->protocol == htons(ETH_P_IPV6)) {
+			struct in6_addr *addr6;
+			int addr_type;
+			struct neighbour *neigh = skb->dst->neighbour;
+
+			if (neigh == NULL)
+				goto tx_error;
+
+			addr6 = (struct in6_addr*)&neigh->primary_key;
+			addr_type = ipv6_addr_type(addr6);
+
+			if (addr_type == IPV6_ADDR_ANY) {
+				addr6 = &ipv6_hdr(skb)->daddr;
+				addr_type = ipv6_addr_type(addr6);
+			}
+
+			if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
+				goto tx_error_icmp;
+
+			dst = addr6->s6_addr32[3];
+		}
+#endif
+		else
+			goto tx_error;
+	}
+
+	tos = tiph->tos;
+	if (tos&1) {
+		if (skb->protocol == htons(ETH_P_IP))
+			tos = old_iph->tos;
+		tos &= ~1;
+	}
+
+	{
+		struct flowi fl = { .oif = tunnel->parms.link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = dst,
+						.saddr = tiph->saddr,
+						.tos = RT_TOS(tos) } },
+				    .proto = IPPROTO_GRE };
+		if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
+			stats->tx_carrier_errors++;
+			goto tx_error;
+		}
+	}
+	tdev = rt->u.dst.dev;
+
+	if (tdev == dev) {
+		ip_rt_put(rt);
+		stats->collisions++;
+		goto tx_error;
+	}
+
+	df = tiph->frag_off;
+	if (df)
+		mtu = dst_mtu(&rt->u.dst) - dev->hard_header_len - tunnel->hlen;
+	else
+		mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
+
+	if (skb->dst)
+		skb->dst->ops->update_pmtu(skb->dst, mtu);
+
+	if (skb->protocol == htons(ETH_P_IP)) {
+		df |= (old_iph->frag_off&htons(IP_DF));
+
+		if ((old_iph->frag_off&htons(IP_DF)) &&
+		    mtu < ntohs(old_iph->tot_len)) {
+			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+			ip_rt_put(rt);
+			goto tx_error;
+		}
+	}
+#ifdef CONFIG_IPV6
+	else if (skb->protocol == htons(ETH_P_IPV6)) {
+		struct rt6_info *rt6 = (struct rt6_info*)skb->dst;
+
+		if (rt6 && mtu < dst_mtu(skb->dst) && mtu >= IPV6_MIN_MTU) {
+			if ((tunnel->parms.iph.daddr &&
+			     !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
+			    rt6->rt6i_dst.plen == 128) {
+				rt6->rt6i_flags |= RTF_MODIFIED;
+				skb->dst->metrics[RTAX_MTU-1] = mtu;
+			}
+		}
+
+		if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
+			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
+			ip_rt_put(rt);
+			goto tx_error;
+		}
+	}
+#endif
+
+	if (tunnel->err_count > 0) {
+		if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
+			tunnel->err_count--;
+
+			dst_link_failure(skb);
+		} else
+			tunnel->err_count = 0;
+	}
+
+	max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen;
+
+	if (skb_headroom(skb) < max_headroom || skb_shared(skb)||
+	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
+		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
+		if (!new_skb) {
+			ip_rt_put(rt);
+			stats->tx_dropped++;
+			dev_kfree_skb(skb);
+			tunnel->recursion--;
+			return 0;
+		}
+		if (skb->sk)
+			skb_set_owner_w(new_skb, skb->sk);
+		dev_kfree_skb(skb);
+		skb = new_skb;
+		old_iph = ip_hdr(skb);
+	}
+
+	skb_reset_transport_header(skb);
+	skb_push(skb, gre_hlen);
+	skb_reset_network_header(skb);
+	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
+			      IPSKB_REROUTED);
+	dst_release(skb->dst);
+	skb->dst = &rt->u.dst;
+
+	/*
+	 *	Push down and install the IPIP header.
+	 */
+
+	iph 			=	ip_hdr(skb);
+	iph->version		=	4;
+	iph->ihl		=	sizeof(struct iphdr) >> 2;
+	iph->frag_off		=	df;
+	iph->protocol		=	IPPROTO_GRE;
+	iph->tos		=	ipgre_ecn_encapsulate(tos, old_iph, skb);
+	iph->daddr		=	rt->rt_dst;
+	iph->saddr		=	rt->rt_src;
+
+	if ((iph->ttl = tiph->ttl) == 0) {
+		if (skb->protocol == htons(ETH_P_IP))
+			iph->ttl = old_iph->ttl;
+#ifdef CONFIG_IPV6
+		else if (skb->protocol == htons(ETH_P_IPV6))
+			iph->ttl = ((struct ipv6hdr*)old_iph)->hop_limit;
+#endif
+		else
+			iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT);
+	}
+
+	((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
+	((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
+				   htons(ETH_P_TEB) : skb->protocol;
+
+	if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
+		__be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
+
+		if (tunnel->parms.o_flags&GRE_SEQ) {
+			++tunnel->o_seqno;
+			*ptr = htonl(tunnel->o_seqno);
+			ptr--;
+		}
+		if (tunnel->parms.o_flags&GRE_KEY) {
+			*ptr = tunnel->parms.o_key;
+			ptr--;
+		}
+		if (tunnel->parms.o_flags&GRE_CSUM) {
+			*ptr = 0;
+			*(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
+		}
+	}
+
+	nf_reset(skb);
+
+	IPTUNNEL_XMIT();
+	tunnel->recursion--;
+	return 0;
+
+tx_error_icmp:
+	dst_link_failure(skb);
+
+tx_error:
+	stats->tx_errors++;
+	dev_kfree_skb(skb);
+	tunnel->recursion--;
+	return 0;
+}
+
+static int ipgre_tunnel_bind_dev(struct net_device *dev)
+{
+	struct net_device *tdev = NULL;
+	struct ip_tunnel *tunnel;
+	struct iphdr *iph;
+	int hlen = LL_MAX_HEADER;
+	int mtu = ETH_DATA_LEN;
+	int addend = sizeof(struct iphdr) + 4;
+
+	tunnel = netdev_priv(dev);
+	iph = &tunnel->parms.iph;
+
+	/* Guess output device to choose reasonable mtu and needed_headroom */
+
+	if (iph->daddr) {
+		struct flowi fl = { .oif = tunnel->parms.link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = iph->daddr,
+						.saddr = iph->saddr,
+						.tos = RT_TOS(iph->tos) } },
+				    .proto = IPPROTO_GRE };
+		struct rtable *rt;
+		if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
+			tdev = rt->u.dst.dev;
+			ip_rt_put(rt);
+		}
+
+		if (dev->type != ARPHRD_ETHER)
+			dev->flags |= IFF_POINTOPOINT;
+	}
+
+	if (!tdev && tunnel->parms.link)
+		tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
+
+	if (tdev) {
+		hlen = tdev->hard_header_len + tdev->needed_headroom;
+		mtu = tdev->mtu;
+	}
+	dev->iflink = tunnel->parms.link;
+
+	/* Precalculate GRE options length */
+	if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
+		if (tunnel->parms.o_flags&GRE_CSUM)
+			addend += 4;
+		if (tunnel->parms.o_flags&GRE_KEY)
+			addend += 4;
+		if (tunnel->parms.o_flags&GRE_SEQ)
+			addend += 4;
+	}
+	dev->needed_headroom = addend + hlen;
+	mtu -= dev->hard_header_len - addend;
+
+	if (mtu < 68)
+		mtu = 68;
+
+	tunnel->hlen = addend;
+
+	return mtu;
+}
+
+static int
+ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	int err = 0;
+	struct ip_tunnel_parm p;
+	struct ip_tunnel *t;
+	struct net *net = dev_net(dev);
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+	switch (cmd) {
+	case SIOCGETTUNNEL:
+		t = NULL;
+		if (dev == ign->fb_tunnel_dev) {
+			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
+				err = -EFAULT;
+				break;
+			}
+			t = ipgre_tunnel_locate(net, &p, 0);
+		}
+		if (t == NULL)
+			t = netdev_priv(dev);
+		memcpy(&p, &t->parms, sizeof(p));
+		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+			err = -EFAULT;
+		break;
+
+	case SIOCADDTUNNEL:
+	case SIOCCHGTUNNEL:
+		err = -EPERM;
+		if (!capable(CAP_NET_ADMIN))
+			goto done;
+
+		err = -EFAULT;
+		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+			goto done;
+
+		err = -EINVAL;
+		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
+		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
+		    ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
+			goto done;
+		if (p.iph.ttl)
+			p.iph.frag_off |= htons(IP_DF);
+
+		if (!(p.i_flags&GRE_KEY))
+			p.i_key = 0;
+		if (!(p.o_flags&GRE_KEY))
+			p.o_key = 0;
+
+		t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
+
+		if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+			if (t != NULL) {
+				if (t->dev != dev) {
+					err = -EEXIST;
+					break;
+				}
+			} else {
+				unsigned nflags=0;
+
+				t = netdev_priv(dev);
+
+				if (ipv4_is_multicast(p.iph.daddr))
+					nflags = IFF_BROADCAST;
+				else if (p.iph.daddr)
+					nflags = IFF_POINTOPOINT;
+
+				if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
+					err = -EINVAL;
+					break;
+				}
+				ipgre_tunnel_unlink(ign, t);
+				t->parms.iph.saddr = p.iph.saddr;
+				t->parms.iph.daddr = p.iph.daddr;
+				t->parms.i_key = p.i_key;
+				t->parms.o_key = p.o_key;
+				memcpy(dev->dev_addr, &p.iph.saddr, 4);
+				memcpy(dev->broadcast, &p.iph.daddr, 4);
+				ipgre_tunnel_link(ign, t);
+				netdev_state_change(dev);
+			}
+		}
+
+		if (t) {
+			err = 0;
+			if (cmd == SIOCCHGTUNNEL) {
+				t->parms.iph.ttl = p.iph.ttl;
+				t->parms.iph.tos = p.iph.tos;
+				t->parms.iph.frag_off = p.iph.frag_off;
+				if (t->parms.link != p.link) {
+					t->parms.link = p.link;
+					dev->mtu = ipgre_tunnel_bind_dev(dev);
+					netdev_state_change(dev);
+				}
+			}
+			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+				err = -EFAULT;
+		} else
+			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+		break;
+
+	case SIOCDELTUNNEL:
+		err = -EPERM;
+		if (!capable(CAP_NET_ADMIN))
+			goto done;
+
+		if (dev == ign->fb_tunnel_dev) {
+			err = -EFAULT;
+			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+				goto done;
+			err = -ENOENT;
+			if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
+				goto done;
+			err = -EPERM;
+			if (t == netdev_priv(ign->fb_tunnel_dev))
+				goto done;
+			dev = t->dev;
+		}
+		unregister_netdevice(dev);
+		err = 0;
+		break;
+
+	default:
+		err = -EINVAL;
+	}
+
+done:
+	return err;
+}
+
+static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	if (new_mtu < 68 ||
+	    new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
+		return -EINVAL;
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+/* Nice toy. Unfortunately, useless in real life :-)
+   It allows to construct virtual multiprotocol broadcast "LAN"
+   over the Internet, provided multicast routing is tuned.
+
+
+   I have no idea was this bicycle invented before me,
+   so that I had to set ARPHRD_IPGRE to a random value.
+   I have an impression, that Cisco could make something similar,
+   but this feature is apparently missing in IOS<=11.2(8).
+
+   I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
+   with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
+
+   ping -t 255 224.66.66.66
+
+   If nobody answers, mbone does not work.
+
+   ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
+   ip addr add 10.66.66.<somewhat>/24 dev Universe
+   ifconfig Universe up
+   ifconfig Universe add fe80::<Your_real_addr>/10
+   ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
+   ftp 10.66.66.66
+   ...
+   ftp fec0:6666:6666::193.233.7.65
+   ...
+
+ */
+
+static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
+			unsigned short type,
+			const void *daddr, const void *saddr, unsigned len)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+	struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
+	__be16 *p = (__be16*)(iph+1);
+
+	memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
+	p[0]		= t->parms.o_flags;
+	p[1]		= htons(type);
+
+	/*
+	 *	Set the source hardware address.
+	 */
+
+	if (saddr)
+		memcpy(&iph->saddr, saddr, 4);
+
+	if (daddr) {
+		memcpy(&iph->daddr, daddr, 4);
+		return t->hlen;
+	}
+	if (iph->daddr && !ipv4_is_multicast(iph->daddr))
+		return t->hlen;
+
+	return -t->hlen;
+}
+
+static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+{
+	struct iphdr *iph = (struct iphdr*) skb_mac_header(skb);
+	memcpy(haddr, &iph->saddr, 4);
+	return 4;
+}
+
+static const struct header_ops ipgre_header_ops = {
+	.create	= ipgre_header,
+	.parse	= ipgre_header_parse,
+};
+
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+static int ipgre_open(struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+
+	if (ipv4_is_multicast(t->parms.iph.daddr)) {
+		struct flowi fl = { .oif = t->parms.link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = t->parms.iph.daddr,
+						.saddr = t->parms.iph.saddr,
+						.tos = RT_TOS(t->parms.iph.tos) } },
+				    .proto = IPPROTO_GRE };
+		struct rtable *rt;
+		if (ip_route_output_key(dev_net(dev), &rt, &fl))
+			return -EADDRNOTAVAIL;
+		dev = rt->u.dst.dev;
+		ip_rt_put(rt);
+		if (__in_dev_get_rtnl(dev) == NULL)
+			return -EADDRNOTAVAIL;
+		t->mlink = dev->ifindex;
+		ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
+	}
+	return 0;
+}
+
+static int ipgre_close(struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+	if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
+		struct in_device *in_dev;
+		in_dev = inetdev_by_index(dev_net(dev), t->mlink);
+		if (in_dev) {
+			ip_mc_dec_group(in_dev, t->parms.iph.daddr);
+			in_dev_put(in_dev);
+		}
+	}
+	return 0;
+}
+
+#endif
+
+static void ipgre_tunnel_setup(struct net_device *dev)
+{
+	dev->init		= ipgre_tunnel_init;
+	dev->uninit		= ipgre_tunnel_uninit;
+	dev->destructor 	= free_netdev;
+	dev->hard_start_xmit	= ipgre_tunnel_xmit;
+	dev->do_ioctl		= ipgre_tunnel_ioctl;
+	dev->change_mtu		= ipgre_tunnel_change_mtu;
+
+	dev->type		= ARPHRD_IPGRE;
+	dev->needed_headroom 	= LL_MAX_HEADER + sizeof(struct iphdr) + 4;
+	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 4;
+	dev->flags		= IFF_NOARP;
+	dev->iflink		= 0;
+	dev->addr_len		= 4;
+	dev->features		|= NETIF_F_NETNS_LOCAL;
+}
+
+static int ipgre_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel;
+	struct iphdr *iph;
+
+	tunnel = netdev_priv(dev);
+	iph = &tunnel->parms.iph;
+
+	tunnel->dev = dev;
+	strcpy(tunnel->parms.name, dev->name);
+
+	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
+	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
+
+	if (iph->daddr) {
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+		if (ipv4_is_multicast(iph->daddr)) {
+			if (!iph->saddr)
+				return -EINVAL;
+			dev->flags = IFF_BROADCAST;
+			dev->header_ops = &ipgre_header_ops;
+			dev->open = ipgre_open;
+			dev->stop = ipgre_close;
+		}
+#endif
+	} else
+		dev->header_ops = &ipgre_header_ops;
+
+	return 0;
+}
+
+static int ipgre_fb_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct iphdr *iph = &tunnel->parms.iph;
+	struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id);
+
+	tunnel->dev = dev;
+	strcpy(tunnel->parms.name, dev->name);
+
+	iph->version		= 4;
+	iph->protocol		= IPPROTO_GRE;
+	iph->ihl		= 5;
+	tunnel->hlen		= sizeof(struct iphdr) + 4;
+
+	dev_hold(dev);
+	ign->tunnels_wc[0]	= tunnel;
+	return 0;
+}
+
+
+static struct net_protocol ipgre_protocol = {
+	.handler	=	ipgre_rcv,
+	.err_handler	=	ipgre_err,
+	.netns_ok	=	1,
+};
+
+static void ipgre_destroy_tunnels(struct ipgre_net *ign)
+{
+	int prio;
+
+	for (prio = 0; prio < 4; prio++) {
+		int h;
+		for (h = 0; h < HASH_SIZE; h++) {
+			struct ip_tunnel *t;
+			while ((t = ign->tunnels[prio][h]) != NULL)
+				unregister_netdevice(t->dev);
+		}
+	}
+}
+
+static int ipgre_init_net(struct net *net)
+{
+	int err;
+	struct ipgre_net *ign;
+
+	err = -ENOMEM;
+	ign = kzalloc(sizeof(struct ipgre_net), GFP_KERNEL);
+	if (ign == NULL)
+		goto err_alloc;
+
+	err = net_assign_generic(net, ipgre_net_id, ign);
+	if (err < 0)
+		goto err_assign;
+
+	ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
+					   ipgre_tunnel_setup);
+	if (!ign->fb_tunnel_dev) {
+		err = -ENOMEM;
+		goto err_alloc_dev;
+	}
+
+	ign->fb_tunnel_dev->init = ipgre_fb_tunnel_init;
+	dev_net_set(ign->fb_tunnel_dev, net);
+	ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
+
+	if ((err = register_netdev(ign->fb_tunnel_dev)))
+		goto err_reg_dev;
+
+	return 0;
+
+err_reg_dev:
+	free_netdev(ign->fb_tunnel_dev);
+err_alloc_dev:
+	/* nothing */
+err_assign:
+	kfree(ign);
+err_alloc:
+	return err;
+}
+
+static void ipgre_exit_net(struct net *net)
+{
+	struct ipgre_net *ign;
+
+	ign = net_generic(net, ipgre_net_id);
+	rtnl_lock();
+	ipgre_destroy_tunnels(ign);
+	rtnl_unlock();
+	kfree(ign);
+}
+
+static struct pernet_operations ipgre_net_ops = {
+	.init = ipgre_init_net,
+	.exit = ipgre_exit_net,
+};
+
+static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+	__be16 flags;
+
+	if (!data)
+		return 0;
+
+	flags = 0;
+	if (data[IFLA_GRE_IFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+	if (data[IFLA_GRE_OFLAGS])
+		flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+	if (flags & (GRE_VERSION|GRE_ROUTING))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+	__be32 daddr;
+
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+			return -EINVAL;
+		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+			return -EADDRNOTAVAIL;
+	}
+
+	if (!data)
+		goto out;
+
+	if (data[IFLA_GRE_REMOTE]) {
+		memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
+		if (!daddr)
+			return -EINVAL;
+	}
+
+out:
+	return ipgre_tunnel_validate(tb, data);
+}
+
+static void ipgre_netlink_parms(struct nlattr *data[],
+				struct ip_tunnel_parm *parms)
+{
+	memset(parms, 0, sizeof(*parms));
+
+	parms->iph.protocol = IPPROTO_GRE;
+
+	if (!data)
+		return;
+
+	if (data[IFLA_GRE_LINK])
+		parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
+
+	if (data[IFLA_GRE_IFLAGS])
+		parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
+
+	if (data[IFLA_GRE_OFLAGS])
+		parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
+
+	if (data[IFLA_GRE_IKEY])
+		parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
+
+	if (data[IFLA_GRE_OKEY])
+		parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
+
+	if (data[IFLA_GRE_LOCAL])
+		parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
+
+	if (data[IFLA_GRE_REMOTE])
+		parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
+
+	if (data[IFLA_GRE_TTL])
+		parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
+
+	if (data[IFLA_GRE_TOS])
+		parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
+
+	if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
+		parms->iph.frag_off = htons(IP_DF);
+}
+
+static int ipgre_tap_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel;
+
+	tunnel = netdev_priv(dev);
+
+	tunnel->dev = dev;
+	strcpy(tunnel->parms.name, dev->name);
+
+	ipgre_tunnel_bind_dev(dev);
+
+	return 0;
+}
+
+static void ipgre_tap_setup(struct net_device *dev)
+{
+
+	ether_setup(dev);
+
+	dev->init		= ipgre_tap_init;
+	dev->uninit		= ipgre_tunnel_uninit;
+	dev->destructor 	= free_netdev;
+	dev->hard_start_xmit	= ipgre_tunnel_xmit;
+	dev->change_mtu		= ipgre_tunnel_change_mtu;
+
+	dev->iflink		= 0;
+	dev->features		|= NETIF_F_NETNS_LOCAL;
+}
+
+static int ipgre_newlink(struct net_device *dev, struct nlattr *tb[],
+			 struct nlattr *data[])
+{
+	struct ip_tunnel *nt;
+	struct net *net = dev_net(dev);
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+	int mtu;
+	int err;
+
+	nt = netdev_priv(dev);
+	ipgre_netlink_parms(data, &nt->parms);
+
+	if (ipgre_tunnel_find(net, &nt->parms, dev->type))
+		return -EEXIST;
+
+	if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
+		random_ether_addr(dev->dev_addr);
+
+	mtu = ipgre_tunnel_bind_dev(dev);
+	if (!tb[IFLA_MTU])
+		dev->mtu = mtu;
+
+	err = register_netdevice(dev);
+	if (err)
+		goto out;
+
+	dev_hold(dev);
+	ipgre_tunnel_link(ign, nt);
+
+out:
+	return err;
+}
+
+static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
+			    struct nlattr *data[])
+{
+	struct ip_tunnel *t, *nt;
+	struct net *net = dev_net(dev);
+	struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+	struct ip_tunnel_parm p;
+	int mtu;
+
+	if (dev == ign->fb_tunnel_dev)
+		return -EINVAL;
+
+	nt = netdev_priv(dev);
+	ipgre_netlink_parms(data, &p);
+
+	t = ipgre_tunnel_locate(net, &p, 0);
+
+	if (t) {
+		if (t->dev != dev)
+			return -EEXIST;
+	} else {
+		unsigned nflags = 0;
+
+		t = nt;
+
+		if (ipv4_is_multicast(p.iph.daddr))
+			nflags = IFF_BROADCAST;
+		else if (p.iph.daddr)
+			nflags = IFF_POINTOPOINT;
+
+		if ((dev->flags ^ nflags) &
+		    (IFF_POINTOPOINT | IFF_BROADCAST))
+			return -EINVAL;
+
+		ipgre_tunnel_unlink(ign, t);
+		t->parms.iph.saddr = p.iph.saddr;
+		t->parms.iph.daddr = p.iph.daddr;
+		t->parms.i_key = p.i_key;
+		memcpy(dev->dev_addr, &p.iph.saddr, 4);
+		memcpy(dev->broadcast, &p.iph.daddr, 4);
+		ipgre_tunnel_link(ign, t);
+		netdev_state_change(dev);
+	}
+
+	t->parms.o_key = p.o_key;
+	t->parms.iph.ttl = p.iph.ttl;
+	t->parms.iph.tos = p.iph.tos;
+	t->parms.iph.frag_off = p.iph.frag_off;
+
+	if (t->parms.link != p.link) {
+		t->parms.link = p.link;
+		mtu = ipgre_tunnel_bind_dev(dev);
+		if (!tb[IFLA_MTU])
+			dev->mtu = mtu;
+		netdev_state_change(dev);
+	}
+
+	return 0;
+}
+
+static size_t ipgre_get_size(const struct net_device *dev)
+{
+	return
+		/* IFLA_GRE_LINK */
+		nla_total_size(4) +
+		/* IFLA_GRE_IFLAGS */
+		nla_total_size(2) +
+		/* IFLA_GRE_OFLAGS */
+		nla_total_size(2) +
+		/* IFLA_GRE_IKEY */
+		nla_total_size(4) +
+		/* IFLA_GRE_OKEY */
+		nla_total_size(4) +
+		/* IFLA_GRE_LOCAL */
+		nla_total_size(4) +
+		/* IFLA_GRE_REMOTE */
+		nla_total_size(4) +
+		/* IFLA_GRE_TTL */
+		nla_total_size(1) +
+		/* IFLA_GRE_TOS */
+		nla_total_size(1) +
+		/* IFLA_GRE_PMTUDISC */
+		nla_total_size(1) +
+		0;
+}
+
+static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct ip_tunnel *t = netdev_priv(dev);
+	struct ip_tunnel_parm *p = &t->parms;
+
+	NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
+	NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
+	NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
+	NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
+	NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
+	NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
+	NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
+	NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
+	NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
+	NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
+	[IFLA_GRE_LINK]		= { .type = NLA_U32 },
+	[IFLA_GRE_IFLAGS]	= { .type = NLA_U16 },
+	[IFLA_GRE_OFLAGS]	= { .type = NLA_U16 },
+	[IFLA_GRE_IKEY]		= { .type = NLA_U32 },
+	[IFLA_GRE_OKEY]		= { .type = NLA_U32 },
+	[IFLA_GRE_LOCAL]	= { .len = FIELD_SIZEOF(struct iphdr, saddr) },
+	[IFLA_GRE_REMOTE]	= { .len = FIELD_SIZEOF(struct iphdr, daddr) },
+	[IFLA_GRE_TTL]		= { .type = NLA_U8 },
+	[IFLA_GRE_TOS]		= { .type = NLA_U8 },
+	[IFLA_GRE_PMTUDISC]	= { .type = NLA_U8 },
+};
+
+static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
+	.kind		= "gre",
+	.maxtype	= IFLA_GRE_MAX,
+	.policy		= ipgre_policy,
+	.priv_size	= sizeof(struct ip_tunnel),
+	.setup		= ipgre_tunnel_setup,
+	.validate	= ipgre_tunnel_validate,
+	.newlink	= ipgre_newlink,
+	.changelink	= ipgre_changelink,
+	.get_size	= ipgre_get_size,
+	.fill_info	= ipgre_fill_info,
+};
+
+static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
+	.kind		= "gretap",
+	.maxtype	= IFLA_GRE_MAX,
+	.policy		= ipgre_policy,
+	.priv_size	= sizeof(struct ip_tunnel),
+	.setup		= ipgre_tap_setup,
+	.validate	= ipgre_tap_validate,
+	.newlink	= ipgre_newlink,
+	.changelink	= ipgre_changelink,
+	.get_size	= ipgre_get_size,
+	.fill_info	= ipgre_fill_info,
+};
+
+/*
+ *	And now the modules code and kernel interface.
+ */
+
+static int __init ipgre_init(void)
+{
+	int err;
+
+	printk(KERN_INFO "GRE over IPv4 tunneling driver\n");
+
+	if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) {
+		printk(KERN_INFO "ipgre init: can't add protocol\n");
+		return -EAGAIN;
+	}
+
+	err = register_pernet_gen_device(&ipgre_net_id, &ipgre_net_ops);
+	if (err < 0)
+		goto gen_device_failed;
+
+	err = rtnl_link_register(&ipgre_link_ops);
+	if (err < 0)
+		goto rtnl_link_failed;
+
+	err = rtnl_link_register(&ipgre_tap_ops);
+	if (err < 0)
+		goto tap_ops_failed;
+
+out:
+	return err;
+
+tap_ops_failed:
+	rtnl_link_unregister(&ipgre_link_ops);
+rtnl_link_failed:
+	unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
+gen_device_failed:
+	inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
+	goto out;
+}
+
+static void __exit ipgre_fini(void)
+{
+	rtnl_link_unregister(&ipgre_tap_ops);
+	rtnl_link_unregister(&ipgre_link_ops);
+	unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops);
+	if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
+		printk(KERN_INFO "ipgre close: can't remove protocol\n");
+}
+
+module_init(ipgre_init);
+module_exit(ipgre_fini);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("gre");
+MODULE_ALIAS_RTNL_LINK("gretap");
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
new file mode 100644
index 0000000..cfb38ac
--- /dev/null
+++ b/net/ipv4/ip_input.c
@@ -0,0 +1,451 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The Internet Protocol (IP) module.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Donald Becker, <becker@super.org>
+ *		Alan Cox, <alan@lxorguk.ukuu.org.uk>
+ *		Richard Underwood
+ *		Stefan Becker, <stefanb@yello.ping.de>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *
+ *
+ * Fixes:
+ *		Alan Cox	:	Commented a couple of minor bits of surplus code
+ *		Alan Cox	:	Undefining IP_FORWARD doesn't include the code
+ *					(just stops a compiler warning).
+ *		Alan Cox	:	Frames with >=MAX_ROUTE record routes, strict routes or loose routes
+ *					are junked rather than corrupting things.
+ *		Alan Cox	:	Frames to bad broadcast subnets are dumped
+ *					We used to process them non broadcast and
+ *					boy could that cause havoc.
+ *		Alan Cox	:	ip_forward sets the free flag on the
+ *					new frame it queues. Still crap because
+ *					it copies the frame but at least it
+ *					doesn't eat memory too.
+ *		Alan Cox	:	Generic queue code and memory fixes.
+ *		Fred Van Kempen :	IP fragment support (borrowed from NET2E)
+ *		Gerhard Koerting:	Forward fragmented frames correctly.
+ *		Gerhard Koerting: 	Fixes to my fix of the above 8-).
+ *		Gerhard Koerting:	IP interface addressing fix.
+ *		Linus Torvalds	:	More robustness checks
+ *		Alan Cox	:	Even more checks: Still not as robust as it ought to be
+ *		Alan Cox	:	Save IP header pointer for later
+ *		Alan Cox	:	ip option setting
+ *		Alan Cox	:	Use ip_tos/ip_ttl settings
+ *		Alan Cox	:	Fragmentation bogosity removed
+ *					(Thanks to Mark.Bush@prg.ox.ac.uk)
+ *		Dmitry Gorodchanin :	Send of a raw packet crash fix.
+ *		Alan Cox	:	Silly ip bug when an overlength
+ *					fragment turns up. Now frees the
+ *					queue.
+ *		Linus Torvalds/ :	Memory leakage on fragmentation
+ *		Alan Cox	:	handling.
+ *		Gerhard Koerting:	Forwarding uses IP priority hints
+ *		Teemu Rantanen	:	Fragment problems.
+ *		Alan Cox	:	General cleanup, comments and reformat
+ *		Alan Cox	:	SNMP statistics
+ *		Alan Cox	:	BSD address rule semantics. Also see
+ *					UDP as there is a nasty checksum issue
+ *					if you do things the wrong way.
+ *		Alan Cox	:	Always defrag, moved IP_FORWARD to the config.in file
+ *		Alan Cox	: 	IP options adjust sk->priority.
+ *		Pedro Roque	:	Fix mtu/length error in ip_forward.
+ *		Alan Cox	:	Avoid ip_chk_addr when possible.
+ *	Richard Underwood	:	IP multicasting.
+ *		Alan Cox	:	Cleaned up multicast handlers.
+ *		Alan Cox	:	RAW sockets demultiplex in the BSD style.
+ *		Gunther Mayer	:	Fix the SNMP reporting typo
+ *		Alan Cox	:	Always in group 224.0.0.1
+ *	Pauline Middelink	:	Fast ip_checksum update when forwarding
+ *					Masquerading support.
+ *		Alan Cox	:	Multicast loopback error for 224.0.0.1
+ *		Alan Cox	:	IP_MULTICAST_LOOP option.
+ *		Alan Cox	:	Use notifiers.
+ *		Bjorn Ekwall	:	Removed ip_csum (from slhc.c too)
+ *		Bjorn Ekwall	:	Moved ip_fast_csum to ip.h (inline!)
+ *		Stefan Becker   :       Send out ICMP HOST REDIRECT
+ *	Arnt Gulbrandsen	:	ip_build_xmit
+ *		Alan Cox	:	Per socket routing cache
+ *		Alan Cox	:	Fixed routing cache, added header cache.
+ *		Alan Cox	:	Loopback didn't work right in original ip_build_xmit - fixed it.
+ *		Alan Cox	:	Only send ICMP_REDIRECT if src/dest are the same net.
+ *		Alan Cox	:	Incoming IP option handling.
+ *		Alan Cox	:	Set saddr on raw output frames as per BSD.
+ *		Alan Cox	:	Stopped broadcast source route explosions.
+ *		Alan Cox	:	Can disable source routing
+ *		Takeshi Sone    :	Masquerading didn't work.
+ *	Dave Bonn,Alan Cox	:	Faster IP forwarding whenever possible.
+ *		Alan Cox	:	Memory leaks, tramples, misc debugging.
+ *		Alan Cox	:	Fixed multicast (by popular demand 8))
+ *		Alan Cox	:	Fixed forwarding (by even more popular demand 8))
+ *		Alan Cox	:	Fixed SNMP statistics [I think]
+ *	Gerhard Koerting	:	IP fragmentation forwarding fix
+ *		Alan Cox	:	Device lock against page fault.
+ *		Alan Cox	:	IP_HDRINCL facility.
+ *	Werner Almesberger	:	Zero fragment bug
+ *		Alan Cox	:	RAW IP frame length bug
+ *		Alan Cox	:	Outgoing firewall on build_xmit
+ *		A.N.Kuznetsov	:	IP_OPTIONS support throughout the kernel
+ *		Alan Cox	:	Multicast routing hooks
+ *		Jos Vos		:	Do accounting *before* call_in_firewall
+ *	Willy Konynenberg	:	Transparent proxying support
+ *
+ *
+ *
+ * To Fix:
+ *		IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient
+ *		and could be made very efficient with the addition of some virtual memory hacks to permit
+ *		the allocation of a buffer that can then be 'grown' by twiddling page tables.
+ *		Output fragmentation wants updating along with the buffer management to use a single
+ *		interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet
+ *		output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause
+ *		fragmentation anyway.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/system.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#include <net/icmp.h>
+#include <net/raw.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/xfrm.h>
+#include <linux/mroute.h>
+#include <linux/netlink.h>
+
+/*
+ *	Process Router Attention IP option
+ */
+int ip_call_ra_chain(struct sk_buff *skb)
+{
+	struct ip_ra_chain *ra;
+	u8 protocol = ip_hdr(skb)->protocol;
+	struct sock *last = NULL;
+	struct net_device *dev = skb->dev;
+
+	read_lock(&ip_ra_lock);
+	for (ra = ip_ra_chain; ra; ra = ra->next) {
+		struct sock *sk = ra->sk;
+
+		/* If socket is bound to an interface, only report
+		 * the packet if it came  from that interface.
+		 */
+		if (sk && inet_sk(sk)->num == protocol &&
+		    (!sk->sk_bound_dev_if ||
+		     sk->sk_bound_dev_if == dev->ifindex) &&
+		    sock_net(sk) == dev_net(dev)) {
+			if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
+				if (ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN)) {
+					read_unlock(&ip_ra_lock);
+					return 1;
+				}
+			}
+			if (last) {
+				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (skb2)
+					raw_rcv(last, skb2);
+			}
+			last = sk;
+		}
+	}
+
+	if (last) {
+		raw_rcv(last, skb);
+		read_unlock(&ip_ra_lock);
+		return 1;
+	}
+	read_unlock(&ip_ra_lock);
+	return 0;
+}
+
+static int ip_local_deliver_finish(struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb->dev);
+
+	__skb_pull(skb, ip_hdrlen(skb));
+
+	/* Point into the IP datagram, just past the header. */
+	skb_reset_transport_header(skb);
+
+	rcu_read_lock();
+	{
+		int protocol = ip_hdr(skb)->protocol;
+		int hash, raw;
+		struct net_protocol *ipprot;
+
+	resubmit:
+		raw = raw_local_deliver(skb, protocol);
+
+		hash = protocol & (MAX_INET_PROTOS - 1);
+		ipprot = rcu_dereference(inet_protos[hash]);
+		if (ipprot != NULL) {
+			int ret;
+
+			if (!net_eq(net, &init_net) && !ipprot->netns_ok) {
+				if (net_ratelimit())
+					printk("%s: proto %d isn't netns-ready\n",
+						__func__, protocol);
+				kfree_skb(skb);
+				goto out;
+			}
+
+			if (!ipprot->no_policy) {
+				if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+					kfree_skb(skb);
+					goto out;
+				}
+				nf_reset(skb);
+			}
+			ret = ipprot->handler(skb);
+			if (ret < 0) {
+				protocol = -ret;
+				goto resubmit;
+			}
+			IP_INC_STATS_BH(net, IPSTATS_MIB_INDELIVERS);
+		} else {
+			if (!raw) {
+				if (xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+					IP_INC_STATS_BH(net, IPSTATS_MIB_INUNKNOWNPROTOS);
+					icmp_send(skb, ICMP_DEST_UNREACH,
+						  ICMP_PROT_UNREACH, 0);
+				}
+			} else
+				IP_INC_STATS_BH(net, IPSTATS_MIB_INDELIVERS);
+			kfree_skb(skb);
+		}
+	}
+ out:
+	rcu_read_unlock();
+
+	return 0;
+}
+
+/*
+ * 	Deliver IP Packets to the higher protocol layers.
+ */
+int ip_local_deliver(struct sk_buff *skb)
+{
+	/*
+	 *	Reassemble IP fragments.
+	 */
+
+	if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
+		if (ip_defrag(skb, IP_DEFRAG_LOCAL_DELIVER))
+			return 0;
+	}
+
+	return NF_HOOK(PF_INET, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
+		       ip_local_deliver_finish);
+}
+
+static inline int ip_rcv_options(struct sk_buff *skb)
+{
+	struct ip_options *opt;
+	struct iphdr *iph;
+	struct net_device *dev = skb->dev;
+
+	/* It looks as overkill, because not all
+	   IP options require packet mangling.
+	   But it is the easiest for now, especially taking
+	   into account that combination of IP options
+	   and running sniffer is extremely rare condition.
+					      --ANK (980813)
+	*/
+	if (skb_cow(skb, skb_headroom(skb))) {
+		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
+		goto drop;
+	}
+
+	iph = ip_hdr(skb);
+	opt = &(IPCB(skb)->opt);
+	opt->optlen = iph->ihl*4 - sizeof(struct iphdr);
+
+	if (ip_options_compile(dev_net(dev), opt, skb)) {
+		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
+		goto drop;
+	}
+
+	if (unlikely(opt->srr)) {
+		struct in_device *in_dev = in_dev_get(dev);
+		if (in_dev) {
+			if (!IN_DEV_SOURCE_ROUTE(in_dev)) {
+				if (IN_DEV_LOG_MARTIANS(in_dev) &&
+				    net_ratelimit())
+					printk(KERN_INFO "source route option "
+					       NIPQUAD_FMT " -> " NIPQUAD_FMT "\n",
+					       NIPQUAD(iph->saddr),
+					       NIPQUAD(iph->daddr));
+				in_dev_put(in_dev);
+				goto drop;
+			}
+
+			in_dev_put(in_dev);
+		}
+
+		if (ip_options_rcv_srr(skb))
+			goto drop;
+	}
+
+	return 0;
+drop:
+	return -1;
+}
+
+static int ip_rcv_finish(struct sk_buff *skb)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	struct rtable *rt;
+
+	/*
+	 *	Initialise the virtual path cache for the packet. It describes
+	 *	how the packet travels inside Linux networking.
+	 */
+	if (skb->dst == NULL) {
+		int err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
+					 skb->dev);
+		if (unlikely(err)) {
+			if (err == -EHOSTUNREACH)
+				IP_INC_STATS_BH(dev_net(skb->dev),
+						IPSTATS_MIB_INADDRERRORS);
+			else if (err == -ENETUNREACH)
+				IP_INC_STATS_BH(dev_net(skb->dev),
+						IPSTATS_MIB_INNOROUTES);
+			goto drop;
+		}
+	}
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (unlikely(skb->dst->tclassid)) {
+		struct ip_rt_acct *st = per_cpu_ptr(ip_rt_acct, smp_processor_id());
+		u32 idx = skb->dst->tclassid;
+		st[idx&0xFF].o_packets++;
+		st[idx&0xFF].o_bytes+=skb->len;
+		st[(idx>>16)&0xFF].i_packets++;
+		st[(idx>>16)&0xFF].i_bytes+=skb->len;
+	}
+#endif
+
+	if (iph->ihl > 5 && ip_rcv_options(skb))
+		goto drop;
+
+	rt = skb->rtable;
+	if (rt->rt_type == RTN_MULTICAST)
+		IP_INC_STATS_BH(dev_net(rt->u.dst.dev), IPSTATS_MIB_INMCASTPKTS);
+	else if (rt->rt_type == RTN_BROADCAST)
+		IP_INC_STATS_BH(dev_net(rt->u.dst.dev), IPSTATS_MIB_INBCASTPKTS);
+
+	return dst_input(skb);
+
+drop:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+/*
+ * 	Main IP Receive routine.
+ */
+int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct iphdr *iph;
+	u32 len;
+
+	/* When the interface is in promisc. mode, drop all the crap
+	 * that it receives, do not try to analyse it.
+	 */
+	if (skb->pkt_type == PACKET_OTHERHOST)
+		goto drop;
+
+	IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INRECEIVES);
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
+		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
+		goto out;
+	}
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto inhdr_error;
+
+	iph = ip_hdr(skb);
+
+	/*
+	 *	RFC1122: 3.2.1.2 MUST silently discard any IP frame that fails the checksum.
+	 *
+	 *	Is the datagram acceptable?
+	 *
+	 *	1.	Length at least the size of an ip header
+	 *	2.	Version of 4
+	 *	3.	Checksums correctly. [Speed optimisation for later, skip loopback checksums]
+	 *	4.	Doesn't have a bogus length
+	 */
+
+	if (iph->ihl < 5 || iph->version != 4)
+		goto inhdr_error;
+
+	if (!pskb_may_pull(skb, iph->ihl*4))
+		goto inhdr_error;
+
+	iph = ip_hdr(skb);
+
+	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
+		goto inhdr_error;
+
+	len = ntohs(iph->tot_len);
+	if (skb->len < len) {
+		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS);
+		goto drop;
+	} else if (len < (iph->ihl*4))
+		goto inhdr_error;
+
+	/* Our transport medium may have padded the buffer out. Now we know it
+	 * is IP we can trim to the true length of the frame.
+	 * Note this now means skb->len holds ntohs(iph->tot_len).
+	 */
+	if (pskb_trim_rcsum(skb, len)) {
+		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
+		goto drop;
+	}
+
+	/* Remove any debris in the socket control block */
+	memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+
+	return NF_HOOK(PF_INET, NF_INET_PRE_ROUTING, skb, dev, NULL,
+		       ip_rcv_finish);
+
+inhdr_error:
+	IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
+drop:
+	kfree_skb(skb);
+out:
+	return NET_RX_DROP;
+}
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
new file mode 100644
index 0000000..2c88da6
--- /dev/null
+++ b/net/ipv4/ip_options.c
@@ -0,0 +1,647 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The options processing module for ip.c
+ *
+ * Authors:	A.N.Kuznetsov
+ *
+ */
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/cipso_ipv4.h>
+
+/*
+ * Write options to IP header, record destination address to
+ * source route option, address of outgoing interface
+ * (we should already know it, so that this  function is allowed be
+ * called only after routing decision) and timestamp,
+ * if we originate this datagram.
+ *
+ * daddr is real destination address, next hop is recorded in IP header.
+ * saddr is address of outgoing interface.
+ */
+
+void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
+			    __be32 daddr, struct rtable *rt, int is_frag)
+{
+	unsigned char *iph = skb_network_header(skb);
+
+	memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
+	memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
+	opt = &(IPCB(skb)->opt);
+
+	if (opt->srr)
+		memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
+
+	if (!is_frag) {
+		if (opt->rr_needaddr)
+			ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);
+		if (opt->ts_needaddr)
+			ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);
+		if (opt->ts_needtime) {
+			struct timespec tv;
+			__be32 midtime;
+			getnstimeofday(&tv);
+			midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
+			memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
+		}
+		return;
+	}
+	if (opt->rr) {
+		memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
+		opt->rr = 0;
+		opt->rr_needaddr = 0;
+	}
+	if (opt->ts) {
+		memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
+		opt->ts = 0;
+		opt->ts_needaddr = opt->ts_needtime = 0;
+	}
+}
+
+/*
+ * Provided (sopt, skb) points to received options,
+ * build in dopt compiled option set appropriate for answering.
+ * i.e. invert SRR option, copy anothers,
+ * and grab room in RR/TS options.
+ *
+ * NOTE: dopt cannot point to skb.
+ */
+
+int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
+{
+	struct ip_options *sopt;
+	unsigned char *sptr, *dptr;
+	int soffset, doffset;
+	int	optlen;
+	__be32	daddr;
+
+	memset(dopt, 0, sizeof(struct ip_options));
+
+	sopt = &(IPCB(skb)->opt);
+
+	if (sopt->optlen == 0) {
+		dopt->optlen = 0;
+		return 0;
+	}
+
+	sptr = skb_network_header(skb);
+	dptr = dopt->__data;
+
+	daddr = skb->rtable->rt_spec_dst;
+
+	if (sopt->rr) {
+		optlen  = sptr[sopt->rr+1];
+		soffset = sptr[sopt->rr+2];
+		dopt->rr = dopt->optlen + sizeof(struct iphdr);
+		memcpy(dptr, sptr+sopt->rr, optlen);
+		if (sopt->rr_needaddr && soffset <= optlen) {
+			if (soffset + 3 > optlen)
+				return -EINVAL;
+			dptr[2] = soffset + 4;
+			dopt->rr_needaddr = 1;
+		}
+		dptr += optlen;
+		dopt->optlen += optlen;
+	}
+	if (sopt->ts) {
+		optlen = sptr[sopt->ts+1];
+		soffset = sptr[sopt->ts+2];
+		dopt->ts = dopt->optlen + sizeof(struct iphdr);
+		memcpy(dptr, sptr+sopt->ts, optlen);
+		if (soffset <= optlen) {
+			if (sopt->ts_needaddr) {
+				if (soffset + 3 > optlen)
+					return -EINVAL;
+				dopt->ts_needaddr = 1;
+				soffset += 4;
+			}
+			if (sopt->ts_needtime) {
+				if (soffset + 3 > optlen)
+					return -EINVAL;
+				if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
+					dopt->ts_needtime = 1;
+					soffset += 4;
+				} else {
+					dopt->ts_needtime = 0;
+
+					if (soffset + 8 <= optlen) {
+						__be32 addr;
+
+						memcpy(&addr, sptr+soffset-1, 4);
+						if (inet_addr_type(dev_net(skb->dst->dev), addr) != RTN_LOCAL) {
+							dopt->ts_needtime = 1;
+							soffset += 8;
+						}
+					}
+				}
+			}
+			dptr[2] = soffset;
+		}
+		dptr += optlen;
+		dopt->optlen += optlen;
+	}
+	if (sopt->srr) {
+		unsigned char * start = sptr+sopt->srr;
+		__be32 faddr;
+
+		optlen  = start[1];
+		soffset = start[2];
+		doffset = 0;
+		if (soffset > optlen)
+			soffset = optlen + 1;
+		soffset -= 4;
+		if (soffset > 3) {
+			memcpy(&faddr, &start[soffset-1], 4);
+			for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
+				memcpy(&dptr[doffset-1], &start[soffset-1], 4);
+			/*
+			 * RFC1812 requires to fix illegal source routes.
+			 */
+			if (memcmp(&ip_hdr(skb)->saddr,
+				   &start[soffset + 3], 4) == 0)
+				doffset -= 4;
+		}
+		if (doffset > 3) {
+			memcpy(&start[doffset-1], &daddr, 4);
+			dopt->faddr = faddr;
+			dptr[0] = start[0];
+			dptr[1] = doffset+3;
+			dptr[2] = 4;
+			dptr += doffset+3;
+			dopt->srr = dopt->optlen + sizeof(struct iphdr);
+			dopt->optlen += doffset+3;
+			dopt->is_strictroute = sopt->is_strictroute;
+		}
+	}
+	if (sopt->cipso) {
+		optlen  = sptr[sopt->cipso+1];
+		dopt->cipso = dopt->optlen+sizeof(struct iphdr);
+		memcpy(dptr, sptr+sopt->cipso, optlen);
+		dptr += optlen;
+		dopt->optlen += optlen;
+	}
+	while (dopt->optlen & 3) {
+		*dptr++ = IPOPT_END;
+		dopt->optlen++;
+	}
+	return 0;
+}
+
+/*
+ *	Options "fragmenting", just fill options not
+ *	allowed in fragments with NOOPs.
+ *	Simple and stupid 8), but the most efficient way.
+ */
+
+void ip_options_fragment(struct sk_buff * skb)
+{
+	unsigned char *optptr = skb_network_header(skb) + sizeof(struct iphdr);
+	struct ip_options * opt = &(IPCB(skb)->opt);
+	int  l = opt->optlen;
+	int  optlen;
+
+	while (l > 0) {
+		switch (*optptr) {
+		case IPOPT_END:
+			return;
+		case IPOPT_NOOP:
+			l--;
+			optptr++;
+			continue;
+		}
+		optlen = optptr[1];
+		if (optlen<2 || optlen>l)
+		  return;
+		if (!IPOPT_COPIED(*optptr))
+			memset(optptr, IPOPT_NOOP, optlen);
+		l -= optlen;
+		optptr += optlen;
+	}
+	opt->ts = 0;
+	opt->rr = 0;
+	opt->rr_needaddr = 0;
+	opt->ts_needaddr = 0;
+	opt->ts_needtime = 0;
+	return;
+}
+
+/*
+ * Verify options and fill pointers in struct options.
+ * Caller should clear *opt, and set opt->data.
+ * If opt == NULL, then skb->data should point to IP header.
+ */
+
+int ip_options_compile(struct net *net,
+		       struct ip_options * opt, struct sk_buff * skb)
+{
+	int l;
+	unsigned char * iph;
+	unsigned char * optptr;
+	int optlen;
+	unsigned char * pp_ptr = NULL;
+	struct rtable *rt = NULL;
+
+	if (skb != NULL) {
+		rt = skb->rtable;
+		optptr = (unsigned char *)&(ip_hdr(skb)[1]);
+	} else
+		optptr = opt->__data;
+	iph = optptr - sizeof(struct iphdr);
+
+	for (l = opt->optlen; l > 0; ) {
+		switch (*optptr) {
+		      case IPOPT_END:
+			for (optptr++, l--; l>0; optptr++, l--) {
+				if (*optptr != IPOPT_END) {
+					*optptr = IPOPT_END;
+					opt->is_changed = 1;
+				}
+			}
+			goto eol;
+		      case IPOPT_NOOP:
+			l--;
+			optptr++;
+			continue;
+		}
+		optlen = optptr[1];
+		if (optlen<2 || optlen>l) {
+			pp_ptr = optptr;
+			goto error;
+		}
+		switch (*optptr) {
+		      case IPOPT_SSRR:
+		      case IPOPT_LSRR:
+			if (optlen < 3) {
+				pp_ptr = optptr + 1;
+				goto error;
+			}
+			if (optptr[2] < 4) {
+				pp_ptr = optptr + 2;
+				goto error;
+			}
+			/* NB: cf RFC-1812 5.2.4.1 */
+			if (opt->srr) {
+				pp_ptr = optptr;
+				goto error;
+			}
+			if (!skb) {
+				if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
+					pp_ptr = optptr + 1;
+					goto error;
+				}
+				memcpy(&opt->faddr, &optptr[3], 4);
+				if (optlen > 7)
+					memmove(&optptr[3], &optptr[7], optlen-7);
+			}
+			opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
+			opt->srr = optptr - iph;
+			break;
+		      case IPOPT_RR:
+			if (opt->rr) {
+				pp_ptr = optptr;
+				goto error;
+			}
+			if (optlen < 3) {
+				pp_ptr = optptr + 1;
+				goto error;
+			}
+			if (optptr[2] < 4) {
+				pp_ptr = optptr + 2;
+				goto error;
+			}
+			if (optptr[2] <= optlen) {
+				if (optptr[2]+3 > optlen) {
+					pp_ptr = optptr + 2;
+					goto error;
+				}
+				if (skb) {
+					memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
+					opt->is_changed = 1;
+				}
+				optptr[2] += 4;
+				opt->rr_needaddr = 1;
+			}
+			opt->rr = optptr - iph;
+			break;
+		      case IPOPT_TIMESTAMP:
+			if (opt->ts) {
+				pp_ptr = optptr;
+				goto error;
+			}
+			if (optlen < 4) {
+				pp_ptr = optptr + 1;
+				goto error;
+			}
+			if (optptr[2] < 5) {
+				pp_ptr = optptr + 2;
+				goto error;
+			}
+			if (optptr[2] <= optlen) {
+				__be32 *timeptr = NULL;
+				if (optptr[2]+3 > optptr[1]) {
+					pp_ptr = optptr + 2;
+					goto error;
+				}
+				switch (optptr[3]&0xF) {
+				      case IPOPT_TS_TSONLY:
+					opt->ts = optptr - iph;
+					if (skb)
+						timeptr = (__be32*)&optptr[optptr[2]-1];
+					opt->ts_needtime = 1;
+					optptr[2] += 4;
+					break;
+				      case IPOPT_TS_TSANDADDR:
+					if (optptr[2]+7 > optptr[1]) {
+						pp_ptr = optptr + 2;
+						goto error;
+					}
+					opt->ts = optptr - iph;
+					if (skb) {
+						memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
+						timeptr = (__be32*)&optptr[optptr[2]+3];
+					}
+					opt->ts_needaddr = 1;
+					opt->ts_needtime = 1;
+					optptr[2] += 8;
+					break;
+				      case IPOPT_TS_PRESPEC:
+					if (optptr[2]+7 > optptr[1]) {
+						pp_ptr = optptr + 2;
+						goto error;
+					}
+					opt->ts = optptr - iph;
+					{
+						__be32 addr;
+						memcpy(&addr, &optptr[optptr[2]-1], 4);
+						if (inet_addr_type(net, addr) == RTN_UNICAST)
+							break;
+						if (skb)
+							timeptr = (__be32*)&optptr[optptr[2]+3];
+					}
+					opt->ts_needtime = 1;
+					optptr[2] += 8;
+					break;
+				      default:
+					if (!skb && !capable(CAP_NET_RAW)) {
+						pp_ptr = optptr + 3;
+						goto error;
+					}
+					break;
+				}
+				if (timeptr) {
+					struct timespec tv;
+					__be32  midtime;
+					getnstimeofday(&tv);
+					midtime = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC + tv.tv_nsec / NSEC_PER_MSEC);
+					memcpy(timeptr, &midtime, sizeof(__be32));
+					opt->is_changed = 1;
+				}
+			} else {
+				unsigned overflow = optptr[3]>>4;
+				if (overflow == 15) {
+					pp_ptr = optptr + 3;
+					goto error;
+				}
+				opt->ts = optptr - iph;
+				if (skb) {
+					optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
+					opt->is_changed = 1;
+				}
+			}
+			break;
+		      case IPOPT_RA:
+			if (optlen < 4) {
+				pp_ptr = optptr + 1;
+				goto error;
+			}
+			if (optptr[2] == 0 && optptr[3] == 0)
+				opt->router_alert = optptr - iph;
+			break;
+		      case IPOPT_CIPSO:
+			if ((!skb && !capable(CAP_NET_RAW)) || opt->cipso) {
+				pp_ptr = optptr;
+				goto error;
+			}
+			opt->cipso = optptr - iph;
+			if (cipso_v4_validate(skb, &optptr)) {
+				pp_ptr = optptr;
+				goto error;
+			}
+			break;
+		      case IPOPT_SEC:
+		      case IPOPT_SID:
+		      default:
+			if (!skb && !capable(CAP_NET_RAW)) {
+				pp_ptr = optptr;
+				goto error;
+			}
+			break;
+		}
+		l -= optlen;
+		optptr += optlen;
+	}
+
+eol:
+	if (!pp_ptr)
+		return 0;
+
+error:
+	if (skb) {
+		icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
+	}
+	return -EINVAL;
+}
+
+
+/*
+ *	Undo all the changes done by ip_options_compile().
+ */
+
+void ip_options_undo(struct ip_options * opt)
+{
+	if (opt->srr) {
+		unsigned  char * optptr = opt->__data+opt->srr-sizeof(struct  iphdr);
+		memmove(optptr+7, optptr+3, optptr[1]-7);
+		memcpy(optptr+3, &opt->faddr, 4);
+	}
+	if (opt->rr_needaddr) {
+		unsigned  char * optptr = opt->__data+opt->rr-sizeof(struct  iphdr);
+		optptr[2] -= 4;
+		memset(&optptr[optptr[2]-1], 0, 4);
+	}
+	if (opt->ts) {
+		unsigned  char * optptr = opt->__data+opt->ts-sizeof(struct  iphdr);
+		if (opt->ts_needtime) {
+			optptr[2] -= 4;
+			memset(&optptr[optptr[2]-1], 0, 4);
+			if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
+				optptr[2] -= 4;
+		}
+		if (opt->ts_needaddr) {
+			optptr[2] -= 4;
+			memset(&optptr[optptr[2]-1], 0, 4);
+		}
+	}
+}
+
+static struct ip_options *ip_options_get_alloc(const int optlen)
+{
+	return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3),
+		       GFP_KERNEL);
+}
+
+static int ip_options_get_finish(struct net *net, struct ip_options **optp,
+				 struct ip_options *opt, int optlen)
+{
+	while (optlen & 3)
+		opt->__data[optlen++] = IPOPT_END;
+	opt->optlen = optlen;
+	if (optlen && ip_options_compile(net, opt, NULL)) {
+		kfree(opt);
+		return -EINVAL;
+	}
+	kfree(*optp);
+	*optp = opt;
+	return 0;
+}
+
+int ip_options_get_from_user(struct net *net, struct ip_options **optp,
+			     unsigned char __user *data, int optlen)
+{
+	struct ip_options *opt = ip_options_get_alloc(optlen);
+
+	if (!opt)
+		return -ENOMEM;
+	if (optlen && copy_from_user(opt->__data, data, optlen)) {
+		kfree(opt);
+		return -EFAULT;
+	}
+	return ip_options_get_finish(net, optp, opt, optlen);
+}
+
+int ip_options_get(struct net *net, struct ip_options **optp,
+		   unsigned char *data, int optlen)
+{
+	struct ip_options *opt = ip_options_get_alloc(optlen);
+
+	if (!opt)
+		return -ENOMEM;
+	if (optlen)
+		memcpy(opt->__data, data, optlen);
+	return ip_options_get_finish(net, optp, opt, optlen);
+}
+
+void ip_forward_options(struct sk_buff *skb)
+{
+	struct   ip_options * opt	= &(IPCB(skb)->opt);
+	unsigned char * optptr;
+	struct rtable *rt = skb->rtable;
+	unsigned char *raw = skb_network_header(skb);
+
+	if (opt->rr_needaddr) {
+		optptr = (unsigned char *)raw + opt->rr;
+		ip_rt_get_source(&optptr[optptr[2]-5], rt);
+		opt->is_changed = 1;
+	}
+	if (opt->srr_is_hit) {
+		int srrptr, srrspace;
+
+		optptr = raw + opt->srr;
+
+		for ( srrptr=optptr[2], srrspace = optptr[1];
+		     srrptr <= srrspace;
+		     srrptr += 4
+		     ) {
+			if (srrptr + 3 > srrspace)
+				break;
+			if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
+				break;
+		}
+		if (srrptr + 3 <= srrspace) {
+			opt->is_changed = 1;
+			ip_rt_get_source(&optptr[srrptr-1], rt);
+			ip_hdr(skb)->daddr = rt->rt_dst;
+			optptr[2] = srrptr+4;
+		} else if (net_ratelimit())
+			printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
+		if (opt->ts_needaddr) {
+			optptr = raw + opt->ts;
+			ip_rt_get_source(&optptr[optptr[2]-9], rt);
+			opt->is_changed = 1;
+		}
+	}
+	if (opt->is_changed) {
+		opt->is_changed = 0;
+		ip_send_check(ip_hdr(skb));
+	}
+}
+
+int ip_options_rcv_srr(struct sk_buff *skb)
+{
+	struct ip_options *opt = &(IPCB(skb)->opt);
+	int srrspace, srrptr;
+	__be32 nexthop;
+	struct iphdr *iph = ip_hdr(skb);
+	unsigned char *optptr = skb_network_header(skb) + opt->srr;
+	struct rtable *rt = skb->rtable;
+	struct rtable *rt2;
+	int err;
+
+	if (!opt->srr)
+		return 0;
+
+	if (skb->pkt_type != PACKET_HOST)
+		return -EINVAL;
+	if (rt->rt_type == RTN_UNICAST) {
+		if (!opt->is_strictroute)
+			return 0;
+		icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
+		return -EINVAL;
+	}
+	if (rt->rt_type != RTN_LOCAL)
+		return -EINVAL;
+
+	for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
+		if (srrptr + 3 > srrspace) {
+			icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
+			return -EINVAL;
+		}
+		memcpy(&nexthop, &optptr[srrptr-1], 4);
+
+		rt = skb->rtable;
+		skb->rtable = NULL;
+		err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
+		rt2 = skb->rtable;
+		if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
+			ip_rt_put(rt2);
+			skb->rtable = rt;
+			return -EINVAL;
+		}
+		ip_rt_put(rt);
+		if (rt2->rt_type != RTN_LOCAL)
+			break;
+		/* Superfast 8) loopback forward */
+		memcpy(&iph->daddr, &optptr[srrptr-1], 4);
+		opt->is_changed = 1;
+	}
+	if (srrptr <= srrspace) {
+		opt->srr_is_hit = 1;
+		opt->is_changed = 1;
+	}
+	return 0;
+}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
new file mode 100644
index 0000000..d2a8f8b
--- /dev/null
+++ b/net/ipv4/ip_output.c
@@ -0,0 +1,1421 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The Internet Protocol (IP) output module.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Donald Becker, <becker@super.org>
+ *		Alan Cox, <Alan.Cox@linux.org>
+ *		Richard Underwood
+ *		Stefan Becker, <stefanb@yello.ping.de>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Hirokazu Takahashi, <taka@valinux.co.jp>
+ *
+ *	See ip_input.c for original log
+ *
+ *	Fixes:
+ *		Alan Cox	:	Missing nonblock feature in ip_build_xmit.
+ *		Mike Kilburn	:	htons() missing in ip_build_xmit.
+ *		Bradford Johnson:	Fix faulty handling of some frames when
+ *					no route is found.
+ *		Alexander Demenshin:	Missing sk/skb free in ip_queue_xmit
+ *					(in case if packet not accepted by
+ *					output firewall rules)
+ *		Mike McLagan	:	Routing by source
+ *		Alexey Kuznetsov:	use new route cache
+ *		Andi Kleen:		Fix broken PMTU recovery and remove
+ *					some redundant tests.
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
+ *		Andi Kleen	: 	Replace ip_reply with ip_send_reply.
+ *		Andi Kleen	:	Split fast and slow ip_build_xmit path
+ *					for decreased register pressure on x86
+ *					and more readibility.
+ *		Marc Boucher	:	When call_out_firewall returns FW_QUEUE,
+ *					silently drop skb instead of failing with -EPERM.
+ *		Detlev Wengorz	:	Copy protocol for fragments.
+ *		Hirokazu Takahashi:	HW checksumming for outgoing UDP
+ *					datagrams.
+ *		Hirokazu Takahashi:	sendfile() on UDP works now.
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/highmem.h>
+
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/xfrm.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#include <net/icmp.h>
+#include <net/checksum.h>
+#include <net/inetpeer.h>
+#include <linux/igmp.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter_bridge.h>
+#include <linux/mroute.h>
+#include <linux/netlink.h>
+#include <linux/tcp.h>
+
+int sysctl_ip_default_ttl __read_mostly = IPDEFTTL;
+
+/* Generate a checksum for an outgoing IP datagram. */
+__inline__ void ip_send_check(struct iphdr *iph)
+{
+	iph->check = 0;
+	iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+}
+
+int __ip_local_out(struct sk_buff *skb)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	iph->tot_len = htons(skb->len);
+	ip_send_check(iph);
+	return nf_hook(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, skb->dst->dev,
+		       dst_output);
+}
+
+int ip_local_out(struct sk_buff *skb)
+{
+	int err;
+
+	err = __ip_local_out(skb);
+	if (likely(err == 1))
+		err = dst_output(skb);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(ip_local_out);
+
+/* dev_loopback_xmit for use with netfilter. */
+static int ip_dev_loopback_xmit(struct sk_buff *newskb)
+{
+	skb_reset_mac_header(newskb);
+	__skb_pull(newskb, skb_network_offset(newskb));
+	newskb->pkt_type = PACKET_LOOPBACK;
+	newskb->ip_summed = CHECKSUM_UNNECESSARY;
+	WARN_ON(!newskb->dst);
+	netif_rx(newskb);
+	return 0;
+}
+
+static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
+{
+	int ttl = inet->uc_ttl;
+
+	if (ttl < 0)
+		ttl = dst_metric(dst, RTAX_HOPLIMIT);
+	return ttl;
+}
+
+/*
+ *		Add an ip header to a skbuff and send it out.
+ *
+ */
+int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
+			  __be32 saddr, __be32 daddr, struct ip_options *opt)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct rtable *rt = skb->rtable;
+	struct iphdr *iph;
+
+	/* Build the IP header. */
+	skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	iph->version  = 4;
+	iph->ihl      = 5;
+	iph->tos      = inet->tos;
+	if (ip_dont_fragment(sk, &rt->u.dst))
+		iph->frag_off = htons(IP_DF);
+	else
+		iph->frag_off = 0;
+	iph->ttl      = ip_select_ttl(inet, &rt->u.dst);
+	iph->daddr    = rt->rt_dst;
+	iph->saddr    = rt->rt_src;
+	iph->protocol = sk->sk_protocol;
+	ip_select_ident(iph, &rt->u.dst, sk);
+
+	if (opt && opt->optlen) {
+		iph->ihl += opt->optlen>>2;
+		ip_options_build(skb, opt, daddr, rt, 0);
+	}
+
+	skb->priority = sk->sk_priority;
+	skb->mark = sk->sk_mark;
+
+	/* Send it out. */
+	return ip_local_out(skb);
+}
+
+EXPORT_SYMBOL_GPL(ip_build_and_send_pkt);
+
+static inline int ip_finish_output2(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb->dst;
+	struct rtable *rt = (struct rtable *)dst;
+	struct net_device *dev = dst->dev;
+	unsigned int hh_len = LL_RESERVED_SPACE(dev);
+
+	if (rt->rt_type == RTN_MULTICAST)
+		IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTMCASTPKTS);
+	else if (rt->rt_type == RTN_BROADCAST)
+		IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTBCASTPKTS);
+
+	/* Be paranoid, rather than too clever. */
+	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
+		struct sk_buff *skb2;
+
+		skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
+		if (skb2 == NULL) {
+			kfree_skb(skb);
+			return -ENOMEM;
+		}
+		if (skb->sk)
+			skb_set_owner_w(skb2, skb->sk);
+		kfree_skb(skb);
+		skb = skb2;
+	}
+
+	if (dst->hh)
+		return neigh_hh_output(dst->hh, skb);
+	else if (dst->neighbour)
+		return dst->neighbour->output(skb);
+
+	if (net_ratelimit())
+		printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n");
+	kfree_skb(skb);
+	return -EINVAL;
+}
+
+static inline int ip_skb_dst_mtu(struct sk_buff *skb)
+{
+	struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL;
+
+	return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ?
+	       skb->dst->dev->mtu : dst_mtu(skb->dst);
+}
+
+static int ip_finish_output(struct sk_buff *skb)
+{
+#if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM)
+	/* Policy lookup after SNAT yielded a new policy */
+	if (skb->dst->xfrm != NULL) {
+		IPCB(skb)->flags |= IPSKB_REROUTED;
+		return dst_output(skb);
+	}
+#endif
+	if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb))
+		return ip_fragment(skb, ip_finish_output2);
+	else
+		return ip_finish_output2(skb);
+}
+
+int ip_mc_output(struct sk_buff *skb)
+{
+	struct sock *sk = skb->sk;
+	struct rtable *rt = skb->rtable;
+	struct net_device *dev = rt->u.dst.dev;
+
+	/*
+	 *	If the indicated interface is up and running, send the packet.
+	 */
+	IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS);
+
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_IP);
+
+	/*
+	 *	Multicasts are looped back for other local users
+	 */
+
+	if (rt->rt_flags&RTCF_MULTICAST) {
+		if ((!sk || inet_sk(sk)->mc_loop)
+#ifdef CONFIG_IP_MROUTE
+		/* Small optimization: do not loopback not local frames,
+		   which returned after forwarding; they will be  dropped
+		   by ip_mr_input in any case.
+		   Note, that local frames are looped back to be delivered
+		   to local recipients.
+
+		   This check is duplicated in ip_mr_input at the moment.
+		 */
+		    && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED))
+#endif
+		) {
+			struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
+			if (newskb)
+				NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb,
+					NULL, newskb->dev,
+					ip_dev_loopback_xmit);
+		}
+
+		/* Multicasts with ttl 0 must not go beyond the host */
+
+		if (ip_hdr(skb)->ttl == 0) {
+			kfree_skb(skb);
+			return 0;
+		}
+	}
+
+	if (rt->rt_flags&RTCF_BROADCAST) {
+		struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
+		if (newskb)
+			NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, NULL,
+				newskb->dev, ip_dev_loopback_xmit);
+	}
+
+	return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, skb->dev,
+			    ip_finish_output,
+			    !(IPCB(skb)->flags & IPSKB_REROUTED));
+}
+
+int ip_output(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dst->dev;
+
+	IP_INC_STATS(dev_net(dev), IPSTATS_MIB_OUTREQUESTS);
+
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_IP);
+
+	return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, dev,
+			    ip_finish_output,
+			    !(IPCB(skb)->flags & IPSKB_REROUTED));
+}
+
+int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
+{
+	struct sock *sk = skb->sk;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_options *opt = inet->opt;
+	struct rtable *rt;
+	struct iphdr *iph;
+
+	/* Skip all of this if the packet is already routed,
+	 * f.e. by something like SCTP.
+	 */
+	rt = skb->rtable;
+	if (rt != NULL)
+		goto packet_routed;
+
+	/* Make sure we can route this packet. */
+	rt = (struct rtable *)__sk_dst_check(sk, 0);
+	if (rt == NULL) {
+		__be32 daddr;
+
+		/* Use correct destination address if we have options. */
+		daddr = inet->daddr;
+		if(opt && opt->srr)
+			daddr = opt->faddr;
+
+		{
+			struct flowi fl = { .oif = sk->sk_bound_dev_if,
+					    .nl_u = { .ip4_u =
+						      { .daddr = daddr,
+							.saddr = inet->saddr,
+							.tos = RT_CONN_FLAGS(sk) } },
+					    .proto = sk->sk_protocol,
+					    .flags = inet_sk_flowi_flags(sk),
+					    .uli_u = { .ports =
+						       { .sport = inet->sport,
+							 .dport = inet->dport } } };
+
+			/* If this fails, retransmit mechanism of transport layer will
+			 * keep trying until route appears or the connection times
+			 * itself out.
+			 */
+			security_sk_classify_flow(sk, &fl);
+			if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0))
+				goto no_route;
+		}
+		sk_setup_caps(sk, &rt->u.dst);
+	}
+	skb->dst = dst_clone(&rt->u.dst);
+
+packet_routed:
+	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+		goto no_route;
+
+	/* OK, we know where to send it, allocate and build IP header. */
+	skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	*((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
+	if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok)
+		iph->frag_off = htons(IP_DF);
+	else
+		iph->frag_off = 0;
+	iph->ttl      = ip_select_ttl(inet, &rt->u.dst);
+	iph->protocol = sk->sk_protocol;
+	iph->saddr    = rt->rt_src;
+	iph->daddr    = rt->rt_dst;
+	/* Transport layer set skb->h.foo itself. */
+
+	if (opt && opt->optlen) {
+		iph->ihl += opt->optlen >> 2;
+		ip_options_build(skb, opt, inet->daddr, rt, 0);
+	}
+
+	ip_select_ident_more(iph, &rt->u.dst, sk,
+			     (skb_shinfo(skb)->gso_segs ?: 1) - 1);
+
+	skb->priority = sk->sk_priority;
+	skb->mark = sk->sk_mark;
+
+	return ip_local_out(skb);
+
+no_route:
+	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+	kfree_skb(skb);
+	return -EHOSTUNREACH;
+}
+
+
+static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
+{
+	to->pkt_type = from->pkt_type;
+	to->priority = from->priority;
+	to->protocol = from->protocol;
+	dst_release(to->dst);
+	to->dst = dst_clone(from->dst);
+	to->dev = from->dev;
+	to->mark = from->mark;
+
+	/* Copy the flags to each fragment. */
+	IPCB(to)->flags = IPCB(from)->flags;
+
+#ifdef CONFIG_NET_SCHED
+	to->tc_index = from->tc_index;
+#endif
+	nf_copy(to, from);
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+	to->nf_trace = from->nf_trace;
+#endif
+#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
+	to->ipvs_property = from->ipvs_property;
+#endif
+	skb_copy_secmark(to, from);
+}
+
+/*
+ *	This IP datagram is too large to be sent in one piece.  Break it up into
+ *	smaller pieces (each of size equal to IP header plus
+ *	a block of the data of the original IP data part) that will yet fit in a
+ *	single device frame, and queue such a frame for sending.
+ */
+
+int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*))
+{
+	struct iphdr *iph;
+	int raw = 0;
+	int ptr;
+	struct net_device *dev;
+	struct sk_buff *skb2;
+	unsigned int mtu, hlen, left, len, ll_rs, pad;
+	int offset;
+	__be16 not_last_frag;
+	struct rtable *rt = skb->rtable;
+	int err = 0;
+
+	dev = rt->u.dst.dev;
+
+	/*
+	 *	Point into the IP datagram header.
+	 */
+
+	iph = ip_hdr(skb);
+
+	if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) {
+		IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
+			  htonl(ip_skb_dst_mtu(skb)));
+		kfree_skb(skb);
+		return -EMSGSIZE;
+	}
+
+	/*
+	 *	Setup starting values.
+	 */
+
+	hlen = iph->ihl * 4;
+	mtu = dst_mtu(&rt->u.dst) - hlen;	/* Size of data space */
+	IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE;
+
+	/* When frag_list is given, use it. First, check its validity:
+	 * some transformers could create wrong frag_list or break existing
+	 * one, it is not prohibited. In this case fall back to copying.
+	 *
+	 * LATER: this step can be merged to real generation of fragments,
+	 * we can switch to copy when see the first bad fragment.
+	 */
+	if (skb_shinfo(skb)->frag_list) {
+		struct sk_buff *frag;
+		int first_len = skb_pagelen(skb);
+		int truesizes = 0;
+
+		if (first_len - hlen > mtu ||
+		    ((first_len - hlen) & 7) ||
+		    (iph->frag_off & htons(IP_MF|IP_OFFSET)) ||
+		    skb_cloned(skb))
+			goto slow_path;
+
+		for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next) {
+			/* Correct geometry. */
+			if (frag->len > mtu ||
+			    ((frag->len & 7) && frag->next) ||
+			    skb_headroom(frag) < hlen)
+			    goto slow_path;
+
+			/* Partially cloned skb? */
+			if (skb_shared(frag))
+				goto slow_path;
+
+			BUG_ON(frag->sk);
+			if (skb->sk) {
+				sock_hold(skb->sk);
+				frag->sk = skb->sk;
+				frag->destructor = sock_wfree;
+				truesizes += frag->truesize;
+			}
+		}
+
+		/* Everything is OK. Generate! */
+
+		err = 0;
+		offset = 0;
+		frag = skb_shinfo(skb)->frag_list;
+		skb_shinfo(skb)->frag_list = NULL;
+		skb->data_len = first_len - skb_headlen(skb);
+		skb->truesize -= truesizes;
+		skb->len = first_len;
+		iph->tot_len = htons(first_len);
+		iph->frag_off = htons(IP_MF);
+		ip_send_check(iph);
+
+		for (;;) {
+			/* Prepare header of the next frame,
+			 * before previous one went down. */
+			if (frag) {
+				frag->ip_summed = CHECKSUM_NONE;
+				skb_reset_transport_header(frag);
+				__skb_push(frag, hlen);
+				skb_reset_network_header(frag);
+				memcpy(skb_network_header(frag), iph, hlen);
+				iph = ip_hdr(frag);
+				iph->tot_len = htons(frag->len);
+				ip_copy_metadata(frag, skb);
+				if (offset == 0)
+					ip_options_fragment(frag);
+				offset += skb->len - hlen;
+				iph->frag_off = htons(offset>>3);
+				if (frag->next != NULL)
+					iph->frag_off |= htons(IP_MF);
+				/* Ready, complete checksum */
+				ip_send_check(iph);
+			}
+
+			err = output(skb);
+
+			if (!err)
+				IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES);
+			if (err || !frag)
+				break;
+
+			skb = frag;
+			frag = skb->next;
+			skb->next = NULL;
+		}
+
+		if (err == 0) {
+			IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS);
+			return 0;
+		}
+
+		while (frag) {
+			skb = frag->next;
+			kfree_skb(frag);
+			frag = skb;
+		}
+		IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
+		return err;
+	}
+
+slow_path:
+	left = skb->len - hlen;		/* Space per frame */
+	ptr = raw + hlen;		/* Where to start from */
+
+	/* for bridged IP traffic encapsulated inside f.e. a vlan header,
+	 * we need to make room for the encapsulating header
+	 */
+	pad = nf_bridge_pad(skb);
+	ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad);
+	mtu -= pad;
+
+	/*
+	 *	Fragment the datagram.
+	 */
+
+	offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3;
+	not_last_frag = iph->frag_off & htons(IP_MF);
+
+	/*
+	 *	Keep copying data until we run out.
+	 */
+
+	while (left > 0) {
+		len = left;
+		/* IF: it doesn't fit, use 'mtu' - the data space left */
+		if (len > mtu)
+			len = mtu;
+		/* IF: we are not sending upto and including the packet end
+		   then align the next start on an eight byte boundary */
+		if (len < left)	{
+			len &= ~7;
+		}
+		/*
+		 *	Allocate buffer.
+		 */
+
+		if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) {
+			NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n");
+			err = -ENOMEM;
+			goto fail;
+		}
+
+		/*
+		 *	Set up data on packet
+		 */
+
+		ip_copy_metadata(skb2, skb);
+		skb_reserve(skb2, ll_rs);
+		skb_put(skb2, len + hlen);
+		skb_reset_network_header(skb2);
+		skb2->transport_header = skb2->network_header + hlen;
+
+		/*
+		 *	Charge the memory for the fragment to any owner
+		 *	it might possess
+		 */
+
+		if (skb->sk)
+			skb_set_owner_w(skb2, skb->sk);
+
+		/*
+		 *	Copy the packet header into the new buffer.
+		 */
+
+		skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen);
+
+		/*
+		 *	Copy a block of the IP datagram.
+		 */
+		if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len))
+			BUG();
+		left -= len;
+
+		/*
+		 *	Fill in the new header fields.
+		 */
+		iph = ip_hdr(skb2);
+		iph->frag_off = htons((offset >> 3));
+
+		/* ANK: dirty, but effective trick. Upgrade options only if
+		 * the segment to be fragmented was THE FIRST (otherwise,
+		 * options are already fixed) and make it ONCE
+		 * on the initial skb, so that all the following fragments
+		 * will inherit fixed options.
+		 */
+		if (offset == 0)
+			ip_options_fragment(skb);
+
+		/*
+		 *	Added AC : If we are fragmenting a fragment that's not the
+		 *		   last fragment then keep MF on each bit
+		 */
+		if (left > 0 || not_last_frag)
+			iph->frag_off |= htons(IP_MF);
+		ptr += len;
+		offset += len;
+
+		/*
+		 *	Put this fragment into the sending queue.
+		 */
+		iph->tot_len = htons(len + hlen);
+
+		ip_send_check(iph);
+
+		err = output(skb2);
+		if (err)
+			goto fail;
+
+		IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES);
+	}
+	kfree_skb(skb);
+	IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS);
+	return err;
+
+fail:
+	kfree_skb(skb);
+	IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
+	return err;
+}
+
+EXPORT_SYMBOL(ip_fragment);
+
+int
+ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb)
+{
+	struct iovec *iov = from;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		if (memcpy_fromiovecend(to, iov, offset, len) < 0)
+			return -EFAULT;
+	} else {
+		__wsum csum = 0;
+		if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0)
+			return -EFAULT;
+		skb->csum = csum_block_add(skb->csum, csum, odd);
+	}
+	return 0;
+}
+
+static inline __wsum
+csum_page(struct page *page, int offset, int copy)
+{
+	char *kaddr;
+	__wsum csum;
+	kaddr = kmap(page);
+	csum = csum_partial(kaddr + offset, copy, 0);
+	kunmap(page);
+	return csum;
+}
+
+static inline int ip_ufo_append_data(struct sock *sk,
+			int getfrag(void *from, char *to, int offset, int len,
+			       int odd, struct sk_buff *skb),
+			void *from, int length, int hh_len, int fragheaderlen,
+			int transhdrlen, int mtu,unsigned int flags)
+{
+	struct sk_buff *skb;
+	int err;
+
+	/* There is support for UDP fragmentation offload by network
+	 * device, so create one single skb packet containing complete
+	 * udp datagram
+	 */
+	if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) {
+		skb = sock_alloc_send_skb(sk,
+			hh_len + fragheaderlen + transhdrlen + 20,
+			(flags & MSG_DONTWAIT), &err);
+
+		if (skb == NULL)
+			return err;
+
+		/* reserve space for Hardware header */
+		skb_reserve(skb, hh_len);
+
+		/* create space for UDP/IP header */
+		skb_put(skb,fragheaderlen + transhdrlen);
+
+		/* initialize network header pointer */
+		skb_reset_network_header(skb);
+
+		/* initialize protocol header pointer */
+		skb->transport_header = skb->network_header + fragheaderlen;
+
+		skb->ip_summed = CHECKSUM_PARTIAL;
+		skb->csum = 0;
+		sk->sk_sndmsg_off = 0;
+
+		/* specify the length of each IP datagram fragment */
+		skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
+		skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
+		__skb_queue_tail(&sk->sk_write_queue, skb);
+	}
+
+	return skb_append_datato_frags(sk, skb, getfrag, from,
+				       (length - transhdrlen));
+}
+
+/*
+ *	ip_append_data() and ip_append_page() can make one large IP datagram
+ *	from many pieces of data. Each pieces will be holded on the socket
+ *	until ip_push_pending_frames() is called. Each piece can be a page
+ *	or non-page data.
+ *
+ *	Not only UDP, other transport protocols - e.g. raw sockets - can use
+ *	this interface potentially.
+ *
+ *	LATER: length must be adjusted by pad at tail, when it is required.
+ */
+int ip_append_data(struct sock *sk,
+		   int getfrag(void *from, char *to, int offset, int len,
+			       int odd, struct sk_buff *skb),
+		   void *from, int length, int transhdrlen,
+		   struct ipcm_cookie *ipc, struct rtable *rt,
+		   unsigned int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sk_buff *skb;
+
+	struct ip_options *opt = NULL;
+	int hh_len;
+	int exthdrlen;
+	int mtu;
+	int copy;
+	int err;
+	int offset = 0;
+	unsigned int maxfraglen, fragheaderlen;
+	int csummode = CHECKSUM_NONE;
+
+	if (flags&MSG_PROBE)
+		return 0;
+
+	if (skb_queue_empty(&sk->sk_write_queue)) {
+		/*
+		 * setup for corking.
+		 */
+		opt = ipc->opt;
+		if (opt) {
+			if (inet->cork.opt == NULL) {
+				inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation);
+				if (unlikely(inet->cork.opt == NULL))
+					return -ENOBUFS;
+			}
+			memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen);
+			inet->cork.flags |= IPCORK_OPT;
+			inet->cork.addr = ipc->addr;
+		}
+		dst_hold(&rt->u.dst);
+		inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ?
+					    rt->u.dst.dev->mtu :
+					    dst_mtu(rt->u.dst.path);
+		inet->cork.dst = &rt->u.dst;
+		inet->cork.length = 0;
+		sk->sk_sndmsg_page = NULL;
+		sk->sk_sndmsg_off = 0;
+		if ((exthdrlen = rt->u.dst.header_len) != 0) {
+			length += exthdrlen;
+			transhdrlen += exthdrlen;
+		}
+	} else {
+		rt = (struct rtable *)inet->cork.dst;
+		if (inet->cork.flags & IPCORK_OPT)
+			opt = inet->cork.opt;
+
+		transhdrlen = 0;
+		exthdrlen = 0;
+		mtu = inet->cork.fragsize;
+	}
+	hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
+
+	fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
+	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
+
+	if (inet->cork.length + length > 0xFFFF - fragheaderlen) {
+		ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen);
+		return -EMSGSIZE;
+	}
+
+	/*
+	 * transhdrlen > 0 means that this is the first fragment and we wish
+	 * it won't be fragmented in the future.
+	 */
+	if (transhdrlen &&
+	    length + fragheaderlen <= mtu &&
+	    rt->u.dst.dev->features & NETIF_F_V4_CSUM &&
+	    !exthdrlen)
+		csummode = CHECKSUM_PARTIAL;
+
+	inet->cork.length += length;
+	if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) &&
+	    (sk->sk_protocol == IPPROTO_UDP) &&
+	    (rt->u.dst.dev->features & NETIF_F_UFO)) {
+		err = ip_ufo_append_data(sk, getfrag, from, length, hh_len,
+					 fragheaderlen, transhdrlen, mtu,
+					 flags);
+		if (err)
+			goto error;
+		return 0;
+	}
+
+	/* So, what's going on in the loop below?
+	 *
+	 * We use calculated fragment length to generate chained skb,
+	 * each of segments is IP fragment ready for sending to network after
+	 * adding appropriate IP header.
+	 */
+
+	if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+		goto alloc_new_skb;
+
+	while (length > 0) {
+		/* Check if the remaining data fits into current packet. */
+		copy = mtu - skb->len;
+		if (copy < length)
+			copy = maxfraglen - skb->len;
+		if (copy <= 0) {
+			char *data;
+			unsigned int datalen;
+			unsigned int fraglen;
+			unsigned int fraggap;
+			unsigned int alloclen;
+			struct sk_buff *skb_prev;
+alloc_new_skb:
+			skb_prev = skb;
+			if (skb_prev)
+				fraggap = skb_prev->len - maxfraglen;
+			else
+				fraggap = 0;
+
+			/*
+			 * If remaining data exceeds the mtu,
+			 * we know we need more fragment(s).
+			 */
+			datalen = length + fraggap;
+			if (datalen > mtu - fragheaderlen)
+				datalen = maxfraglen - fragheaderlen;
+			fraglen = datalen + fragheaderlen;
+
+			if ((flags & MSG_MORE) &&
+			    !(rt->u.dst.dev->features&NETIF_F_SG))
+				alloclen = mtu;
+			else
+				alloclen = datalen + fragheaderlen;
+
+			/* The last fragment gets additional space at tail.
+			 * Note, with MSG_MORE we overallocate on fragments,
+			 * because we have no idea what fragment will be
+			 * the last.
+			 */
+			if (datalen == length + fraggap)
+				alloclen += rt->u.dst.trailer_len;
+
+			if (transhdrlen) {
+				skb = sock_alloc_send_skb(sk,
+						alloclen + hh_len + 15,
+						(flags & MSG_DONTWAIT), &err);
+			} else {
+				skb = NULL;
+				if (atomic_read(&sk->sk_wmem_alloc) <=
+				    2 * sk->sk_sndbuf)
+					skb = sock_wmalloc(sk,
+							   alloclen + hh_len + 15, 1,
+							   sk->sk_allocation);
+				if (unlikely(skb == NULL))
+					err = -ENOBUFS;
+			}
+			if (skb == NULL)
+				goto error;
+
+			/*
+			 *	Fill in the control structures
+			 */
+			skb->ip_summed = csummode;
+			skb->csum = 0;
+			skb_reserve(skb, hh_len);
+
+			/*
+			 *	Find where to start putting bytes.
+			 */
+			data = skb_put(skb, fraglen);
+			skb_set_network_header(skb, exthdrlen);
+			skb->transport_header = (skb->network_header +
+						 fragheaderlen);
+			data += fragheaderlen;
+
+			if (fraggap) {
+				skb->csum = skb_copy_and_csum_bits(
+					skb_prev, maxfraglen,
+					data + transhdrlen, fraggap, 0);
+				skb_prev->csum = csum_sub(skb_prev->csum,
+							  skb->csum);
+				data += fraggap;
+				pskb_trim_unique(skb_prev, maxfraglen);
+			}
+
+			copy = datalen - transhdrlen - fraggap;
+			if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
+				err = -EFAULT;
+				kfree_skb(skb);
+				goto error;
+			}
+
+			offset += copy;
+			length -= datalen - fraggap;
+			transhdrlen = 0;
+			exthdrlen = 0;
+			csummode = CHECKSUM_NONE;
+
+			/*
+			 * Put the packet on the pending queue.
+			 */
+			__skb_queue_tail(&sk->sk_write_queue, skb);
+			continue;
+		}
+
+		if (copy > length)
+			copy = length;
+
+		if (!(rt->u.dst.dev->features&NETIF_F_SG)) {
+			unsigned int off;
+
+			off = skb->len;
+			if (getfrag(from, skb_put(skb, copy),
+					offset, copy, off, skb) < 0) {
+				__skb_trim(skb, off);
+				err = -EFAULT;
+				goto error;
+			}
+		} else {
+			int i = skb_shinfo(skb)->nr_frags;
+			skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1];
+			struct page *page = sk->sk_sndmsg_page;
+			int off = sk->sk_sndmsg_off;
+			unsigned int left;
+
+			if (page && (left = PAGE_SIZE - off) > 0) {
+				if (copy >= left)
+					copy = left;
+				if (page != frag->page) {
+					if (i == MAX_SKB_FRAGS) {
+						err = -EMSGSIZE;
+						goto error;
+					}
+					get_page(page);
+					skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0);
+					frag = &skb_shinfo(skb)->frags[i];
+				}
+			} else if (i < MAX_SKB_FRAGS) {
+				if (copy > PAGE_SIZE)
+					copy = PAGE_SIZE;
+				page = alloc_pages(sk->sk_allocation, 0);
+				if (page == NULL)  {
+					err = -ENOMEM;
+					goto error;
+				}
+				sk->sk_sndmsg_page = page;
+				sk->sk_sndmsg_off = 0;
+
+				skb_fill_page_desc(skb, i, page, 0, 0);
+				frag = &skb_shinfo(skb)->frags[i];
+			} else {
+				err = -EMSGSIZE;
+				goto error;
+			}
+			if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) {
+				err = -EFAULT;
+				goto error;
+			}
+			sk->sk_sndmsg_off += copy;
+			frag->size += copy;
+			skb->len += copy;
+			skb->data_len += copy;
+			skb->truesize += copy;
+			atomic_add(copy, &sk->sk_wmem_alloc);
+		}
+		offset += copy;
+		length -= copy;
+	}
+
+	return 0;
+
+error:
+	inet->cork.length -= length;
+	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);
+	return err;
+}
+
+ssize_t	ip_append_page(struct sock *sk, struct page *page,
+		       int offset, size_t size, int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sk_buff *skb;
+	struct rtable *rt;
+	struct ip_options *opt = NULL;
+	int hh_len;
+	int mtu;
+	int len;
+	int err;
+	unsigned int maxfraglen, fragheaderlen, fraggap;
+
+	if (inet->hdrincl)
+		return -EPERM;
+
+	if (flags&MSG_PROBE)
+		return 0;
+
+	if (skb_queue_empty(&sk->sk_write_queue))
+		return -EINVAL;
+
+	rt = (struct rtable *)inet->cork.dst;
+	if (inet->cork.flags & IPCORK_OPT)
+		opt = inet->cork.opt;
+
+	if (!(rt->u.dst.dev->features&NETIF_F_SG))
+		return -EOPNOTSUPP;
+
+	hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
+	mtu = inet->cork.fragsize;
+
+	fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0);
+	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen;
+
+	if (inet->cork.length + size > 0xFFFF - fragheaderlen) {
+		ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
+		return -EMSGSIZE;
+	}
+
+	if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL)
+		return -EINVAL;
+
+	inet->cork.length += size;
+	if ((sk->sk_protocol == IPPROTO_UDP) &&
+	    (rt->u.dst.dev->features & NETIF_F_UFO)) {
+		skb_shinfo(skb)->gso_size = mtu - fragheaderlen;
+		skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
+	}
+
+
+	while (size > 0) {
+		int i;
+
+		if (skb_is_gso(skb))
+			len = size;
+		else {
+
+			/* Check if the remaining data fits into current packet. */
+			len = mtu - skb->len;
+			if (len < size)
+				len = maxfraglen - skb->len;
+		}
+		if (len <= 0) {
+			struct sk_buff *skb_prev;
+			int alloclen;
+
+			skb_prev = skb;
+			fraggap = skb_prev->len - maxfraglen;
+
+			alloclen = fragheaderlen + hh_len + fraggap + 15;
+			skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation);
+			if (unlikely(!skb)) {
+				err = -ENOBUFS;
+				goto error;
+			}
+
+			/*
+			 *	Fill in the control structures
+			 */
+			skb->ip_summed = CHECKSUM_NONE;
+			skb->csum = 0;
+			skb_reserve(skb, hh_len);
+
+			/*
+			 *	Find where to start putting bytes.
+			 */
+			skb_put(skb, fragheaderlen + fraggap);
+			skb_reset_network_header(skb);
+			skb->transport_header = (skb->network_header +
+						 fragheaderlen);
+			if (fraggap) {
+				skb->csum = skb_copy_and_csum_bits(skb_prev,
+								   maxfraglen,
+						    skb_transport_header(skb),
+								   fraggap, 0);
+				skb_prev->csum = csum_sub(skb_prev->csum,
+							  skb->csum);
+				pskb_trim_unique(skb_prev, maxfraglen);
+			}
+
+			/*
+			 * Put the packet on the pending queue.
+			 */
+			__skb_queue_tail(&sk->sk_write_queue, skb);
+			continue;
+		}
+
+		i = skb_shinfo(skb)->nr_frags;
+		if (len > size)
+			len = size;
+		if (skb_can_coalesce(skb, i, page, offset)) {
+			skb_shinfo(skb)->frags[i-1].size += len;
+		} else if (i < MAX_SKB_FRAGS) {
+			get_page(page);
+			skb_fill_page_desc(skb, i, page, offset, len);
+		} else {
+			err = -EMSGSIZE;
+			goto error;
+		}
+
+		if (skb->ip_summed == CHECKSUM_NONE) {
+			__wsum csum;
+			csum = csum_page(page, offset, len);
+			skb->csum = csum_block_add(skb->csum, csum, skb->len);
+		}
+
+		skb->len += len;
+		skb->data_len += len;
+		skb->truesize += len;
+		atomic_add(len, &sk->sk_wmem_alloc);
+		offset += len;
+		size -= len;
+	}
+	return 0;
+
+error:
+	inet->cork.length -= size;
+	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS);
+	return err;
+}
+
+static void ip_cork_release(struct inet_sock *inet)
+{
+	inet->cork.flags &= ~IPCORK_OPT;
+	kfree(inet->cork.opt);
+	inet->cork.opt = NULL;
+	dst_release(inet->cork.dst);
+	inet->cork.dst = NULL;
+}
+
+/*
+ *	Combined all pending IP fragments on the socket as one IP datagram
+ *	and push them out.
+ */
+int ip_push_pending_frames(struct sock *sk)
+{
+	struct sk_buff *skb, *tmp_skb;
+	struct sk_buff **tail_skb;
+	struct inet_sock *inet = inet_sk(sk);
+	struct net *net = sock_net(sk);
+	struct ip_options *opt = NULL;
+	struct rtable *rt = (struct rtable *)inet->cork.dst;
+	struct iphdr *iph;
+	__be16 df = 0;
+	__u8 ttl;
+	int err = 0;
+
+	if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL)
+		goto out;
+	tail_skb = &(skb_shinfo(skb)->frag_list);
+
+	/* move skb->data to ip header from ext header */
+	if (skb->data < skb_network_header(skb))
+		__skb_pull(skb, skb_network_offset(skb));
+	while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
+		__skb_pull(tmp_skb, skb_network_header_len(skb));
+		*tail_skb = tmp_skb;
+		tail_skb = &(tmp_skb->next);
+		skb->len += tmp_skb->len;
+		skb->data_len += tmp_skb->len;
+		skb->truesize += tmp_skb->truesize;
+		__sock_put(tmp_skb->sk);
+		tmp_skb->destructor = NULL;
+		tmp_skb->sk = NULL;
+	}
+
+	/* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow
+	 * to fragment the frame generated here. No matter, what transforms
+	 * how transforms change size of the packet, it will come out.
+	 */
+	if (inet->pmtudisc < IP_PMTUDISC_DO)
+		skb->local_df = 1;
+
+	/* DF bit is set when we want to see DF on outgoing frames.
+	 * If local_df is set too, we still allow to fragment this frame
+	 * locally. */
+	if (inet->pmtudisc >= IP_PMTUDISC_DO ||
+	    (skb->len <= dst_mtu(&rt->u.dst) &&
+	     ip_dont_fragment(sk, &rt->u.dst)))
+		df = htons(IP_DF);
+
+	if (inet->cork.flags & IPCORK_OPT)
+		opt = inet->cork.opt;
+
+	if (rt->rt_type == RTN_MULTICAST)
+		ttl = inet->mc_ttl;
+	else
+		ttl = ip_select_ttl(inet, &rt->u.dst);
+
+	iph = (struct iphdr *)skb->data;
+	iph->version = 4;
+	iph->ihl = 5;
+	if (opt) {
+		iph->ihl += opt->optlen>>2;
+		ip_options_build(skb, opt, inet->cork.addr, rt, 0);
+	}
+	iph->tos = inet->tos;
+	iph->frag_off = df;
+	ip_select_ident(iph, &rt->u.dst, sk);
+	iph->ttl = ttl;
+	iph->protocol = sk->sk_protocol;
+	iph->saddr = rt->rt_src;
+	iph->daddr = rt->rt_dst;
+
+	skb->priority = sk->sk_priority;
+	skb->mark = sk->sk_mark;
+	skb->dst = dst_clone(&rt->u.dst);
+
+	if (iph->protocol == IPPROTO_ICMP)
+		icmp_out_count(net, ((struct icmphdr *)
+			skb_transport_header(skb))->type);
+
+	/* Netfilter gets whole the not fragmented skb. */
+	err = ip_local_out(skb);
+	if (err) {
+		if (err > 0)
+			err = inet->recverr ? net_xmit_errno(err) : 0;
+		if (err)
+			goto error;
+	}
+
+out:
+	ip_cork_release(inet);
+	return err;
+
+error:
+	IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);
+	goto out;
+}
+
+/*
+ *	Throw away all pending data on the socket.
+ */
+void ip_flush_pending_frames(struct sock *sk)
+{
+	struct sk_buff *skb;
+
+	while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL)
+		kfree_skb(skb);
+
+	ip_cork_release(inet_sk(sk));
+}
+
+
+/*
+ *	Fetch data from kernel space and fill in checksum if needed.
+ */
+static int ip_reply_glue_bits(void *dptr, char *to, int offset,
+			      int len, int odd, struct sk_buff *skb)
+{
+	__wsum csum;
+
+	csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0);
+	skb->csum = csum_block_add(skb->csum, csum, odd);
+	return 0;
+}
+
+/*
+ *	Generic function to send a packet as reply to another packet.
+ *	Used to send TCP resets so far. ICMP should use this function too.
+ *
+ *	Should run single threaded per socket because it uses the sock
+ *     	structure to pass arguments.
+ */
+void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg,
+		   unsigned int len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct {
+		struct ip_options	opt;
+		char			data[40];
+	} replyopts;
+	struct ipcm_cookie ipc;
+	__be32 daddr;
+	struct rtable *rt = skb->rtable;
+
+	if (ip_options_echo(&replyopts.opt, skb))
+		return;
+
+	daddr = ipc.addr = rt->rt_src;
+	ipc.opt = NULL;
+
+	if (replyopts.opt.optlen) {
+		ipc.opt = &replyopts.opt;
+
+		if (ipc.opt->srr)
+			daddr = replyopts.opt.faddr;
+	}
+
+	{
+		struct flowi fl = { .oif = arg->bound_dev_if,
+				    .nl_u = { .ip4_u =
+					      { .daddr = daddr,
+						.saddr = rt->rt_spec_dst,
+						.tos = RT_TOS(ip_hdr(skb)->tos) } },
+				    /* Not quite clean, but right. */
+				    .uli_u = { .ports =
+					       { .sport = tcp_hdr(skb)->dest,
+						 .dport = tcp_hdr(skb)->source } },
+				    .proto = sk->sk_protocol,
+				    .flags = ip_reply_arg_flowi_flags(arg) };
+		security_skb_classify_flow(skb, &fl);
+		if (ip_route_output_key(sock_net(sk), &rt, &fl))
+			return;
+	}
+
+	/* And let IP do all the hard work.
+
+	   This chunk is not reenterable, hence spinlock.
+	   Note that it uses the fact, that this function is called
+	   with locally disabled BH and that sk cannot be already spinlocked.
+	 */
+	bh_lock_sock(sk);
+	inet->tos = ip_hdr(skb)->tos;
+	sk->sk_priority = skb->priority;
+	sk->sk_protocol = ip_hdr(skb)->protocol;
+	sk->sk_bound_dev_if = arg->bound_dev_if;
+	ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0,
+		       &ipc, rt, MSG_DONTWAIT);
+	if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
+		if (arg->csumoffset >= 0)
+			*((__sum16 *)skb_transport_header(skb) +
+			  arg->csumoffset) = csum_fold(csum_add(skb->csum,
+								arg->csum));
+		skb->ip_summed = CHECKSUM_NONE;
+		ip_push_pending_frames(sk);
+	}
+
+	bh_unlock_sock(sk);
+
+	ip_rt_put(rt);
+}
+
+void __init ip_init(void)
+{
+	ip_rt_init();
+	inet_initpeers();
+
+#if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS)
+	igmp_mc_proc_init();
+#endif
+}
+
+EXPORT_SYMBOL(ip_generic_getfrag);
+EXPORT_SYMBOL(ip_queue_xmit);
+EXPORT_SYMBOL(ip_send_check);
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
new file mode 100644
index 0000000..465abf0
--- /dev/null
+++ b/net/ipv4/ip_sockglue.c
@@ -0,0 +1,1234 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The IP to API glue.
+ *
+ * Authors:	see ip.c
+ *
+ * Fixes:
+ *		Many		:	Split from ip.c , see ip.c for history.
+ *		Martin Mares	:	TOS setting fixed.
+ *		Alan Cox	:	Fixed a couple of oopses in Martin's
+ *					TOS tweaks.
+ *		Mike McLagan	:	Routing by source
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/tcp_states.h>
+#include <linux/udp.h>
+#include <linux/igmp.h>
+#include <linux/netfilter.h>
+#include <linux/route.h>
+#include <linux/mroute.h>
+#include <net/route.h>
+#include <net/xfrm.h>
+#include <net/compat.h>
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+#include <net/transp_v6.h>
+#endif
+
+#include <linux/errqueue.h>
+#include <asm/uaccess.h>
+
+#define IP_CMSG_PKTINFO		1
+#define IP_CMSG_TTL		2
+#define IP_CMSG_TOS		4
+#define IP_CMSG_RECVOPTS	8
+#define IP_CMSG_RETOPTS		16
+#define IP_CMSG_PASSSEC		32
+
+/*
+ *	SOL_IP control messages.
+ */
+
+static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct in_pktinfo info;
+	struct rtable *rt = skb->rtable;
+
+	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
+	if (rt) {
+		info.ipi_ifindex = rt->rt_iif;
+		info.ipi_spec_dst.s_addr = rt->rt_spec_dst;
+	} else {
+		info.ipi_ifindex = 0;
+		info.ipi_spec_dst.s_addr = 0;
+	}
+
+	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
+}
+
+static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
+{
+	int ttl = ip_hdr(skb)->ttl;
+	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
+}
+
+static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
+{
+	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
+}
+
+static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
+{
+	if (IPCB(skb)->opt.optlen == 0)
+		return;
+
+	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
+		 ip_hdr(skb) + 1);
+}
+
+
+static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
+{
+	unsigned char optbuf[sizeof(struct ip_options) + 40];
+	struct ip_options * opt = (struct ip_options*)optbuf;
+
+	if (IPCB(skb)->opt.optlen == 0)
+		return;
+
+	if (ip_options_echo(opt, skb)) {
+		msg->msg_flags |= MSG_CTRUNC;
+		return;
+	}
+	ip_options_undo(opt);
+
+	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
+}
+
+static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
+{
+	char *secdata;
+	u32 seclen, secid;
+	int err;
+
+	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
+	if (err)
+		return;
+
+	err = security_secid_to_secctx(secid, &secdata, &seclen);
+	if (err)
+		return;
+
+	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
+	security_release_secctx(secdata, seclen);
+}
+
+
+void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct inet_sock *inet = inet_sk(skb->sk);
+	unsigned flags = inet->cmsg_flags;
+
+	/* Ordered by supposed usage frequency */
+	if (flags & 1)
+		ip_cmsg_recv_pktinfo(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_ttl(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_tos(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_opts(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_retopts(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_security(msg, skb);
+}
+
+int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc)
+{
+	int err;
+	struct cmsghdr *cmsg;
+
+	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+		if (!CMSG_OK(msg, cmsg))
+			return -EINVAL;
+		if (cmsg->cmsg_level != SOL_IP)
+			continue;
+		switch (cmsg->cmsg_type) {
+		case IP_RETOPTS:
+			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg), err < 40 ? err : 40);
+			if (err)
+				return err;
+			break;
+		case IP_PKTINFO:
+		{
+			struct in_pktinfo *info;
+			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
+				return -EINVAL;
+			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
+			ipc->oif = info->ipi_ifindex;
+			ipc->addr = info->ipi_spec_dst.s_addr;
+			break;
+		}
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+
+/* Special input handler for packets caught by router alert option.
+   They are selected only by protocol field, and then processed likely
+   local ones; but only if someone wants them! Otherwise, router
+   not running rsvpd will kill RSVP.
+
+   It is user level problem, what it will make with them.
+   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
+   but receiver should be enough clever f.e. to forward mtrace requests,
+   sent to multicast group to reach destination designated router.
+ */
+struct ip_ra_chain *ip_ra_chain;
+DEFINE_RWLOCK(ip_ra_lock);
+
+int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *))
+{
+	struct ip_ra_chain *ra, *new_ra, **rap;
+
+	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->num == IPPROTO_RAW)
+		return -EINVAL;
+
+	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
+
+	write_lock_bh(&ip_ra_lock);
+	for (rap = &ip_ra_chain; (ra=*rap) != NULL; rap = &ra->next) {
+		if (ra->sk == sk) {
+			if (on) {
+				write_unlock_bh(&ip_ra_lock);
+				kfree(new_ra);
+				return -EADDRINUSE;
+			}
+			*rap = ra->next;
+			write_unlock_bh(&ip_ra_lock);
+
+			if (ra->destructor)
+				ra->destructor(sk);
+			sock_put(sk);
+			kfree(ra);
+			return 0;
+		}
+	}
+	if (new_ra == NULL) {
+		write_unlock_bh(&ip_ra_lock);
+		return -ENOBUFS;
+	}
+	new_ra->sk = sk;
+	new_ra->destructor = destructor;
+
+	new_ra->next = ra;
+	*rap = new_ra;
+	sock_hold(sk);
+	write_unlock_bh(&ip_ra_lock);
+
+	return 0;
+}
+
+void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
+		   __be16 port, u32 info, u8 *payload)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sock_exterr_skb *serr;
+
+	if (!inet->recverr)
+		return;
+
+	skb = skb_clone(skb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	serr = SKB_EXT_ERR(skb);
+	serr->ee.ee_errno = err;
+	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
+	serr->ee.ee_type = icmp_hdr(skb)->type;
+	serr->ee.ee_code = icmp_hdr(skb)->code;
+	serr->ee.ee_pad = 0;
+	serr->ee.ee_info = info;
+	serr->ee.ee_data = 0;
+	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
+				   skb_network_header(skb);
+	serr->port = port;
+
+	if (skb_pull(skb, payload - skb->data) != NULL) {
+		skb_reset_transport_header(skb);
+		if (sock_queue_err_skb(sk, skb) == 0)
+			return;
+	}
+	kfree_skb(skb);
+}
+
+void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sock_exterr_skb *serr;
+	struct iphdr *iph;
+	struct sk_buff *skb;
+
+	if (!inet->recverr)
+		return;
+
+	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	skb_put(skb, sizeof(struct iphdr));
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	iph->daddr = daddr;
+
+	serr = SKB_EXT_ERR(skb);
+	serr->ee.ee_errno = err;
+	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+	serr->ee.ee_type = 0;
+	serr->ee.ee_code = 0;
+	serr->ee.ee_pad = 0;
+	serr->ee.ee_info = info;
+	serr->ee.ee_data = 0;
+	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
+	serr->port = port;
+
+	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
+	skb_reset_transport_header(skb);
+
+	if (sock_queue_err_skb(sk, skb))
+		kfree_skb(skb);
+}
+
+/*
+ *	Handle MSG_ERRQUEUE
+ */
+int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
+{
+	struct sock_exterr_skb *serr;
+	struct sk_buff *skb, *skb2;
+	struct sockaddr_in *sin;
+	struct {
+		struct sock_extended_err ee;
+		struct sockaddr_in	 offender;
+	} errhdr;
+	int err;
+	int copied;
+
+	err = -EAGAIN;
+	skb = skb_dequeue(&sk->sk_error_queue);
+	if (skb == NULL)
+		goto out;
+
+	copied = skb->len;
+	if (copied > len) {
+		msg->msg_flags |= MSG_TRUNC;
+		copied = len;
+	}
+	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	if (err)
+		goto out_free_skb;
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	serr = SKB_EXT_ERR(skb);
+
+	sin = (struct sockaddr_in *)msg->msg_name;
+	if (sin) {
+		sin->sin_family = AF_INET;
+		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
+						   serr->addr_offset);
+		sin->sin_port = serr->port;
+		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
+	}
+
+	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
+	sin = &errhdr.offender;
+	sin->sin_family = AF_UNSPEC;
+	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
+		struct inet_sock *inet = inet_sk(sk);
+
+		sin->sin_family = AF_INET;
+		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
+		sin->sin_port = 0;
+		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
+		if (inet->cmsg_flags)
+			ip_cmsg_recv(msg, skb);
+	}
+
+	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
+
+	/* Now we could try to dump offended packet options */
+
+	msg->msg_flags |= MSG_ERRQUEUE;
+	err = copied;
+
+	/* Reset and regenerate socket error */
+	spin_lock_bh(&sk->sk_error_queue.lock);
+	sk->sk_err = 0;
+	if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
+		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
+		spin_unlock_bh(&sk->sk_error_queue.lock);
+		sk->sk_error_report(sk);
+	} else
+		spin_unlock_bh(&sk->sk_error_queue.lock);
+
+out_free_skb:
+	kfree_skb(skb);
+out:
+	return err;
+}
+
+
+/*
+ *	Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
+ *	an IP socket.
+ */
+
+static int do_ip_setsockopt(struct sock *sk, int level,
+			    int optname, char __user *optval, int optlen)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	int val=0,err;
+
+	if (((1<<optname) & ((1<<IP_PKTINFO) | (1<<IP_RECVTTL) |
+			     (1<<IP_RECVOPTS) | (1<<IP_RECVTOS) |
+			     (1<<IP_RETOPTS) | (1<<IP_TOS) |
+			     (1<<IP_TTL) | (1<<IP_HDRINCL) |
+			     (1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) |
+			     (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
+			     (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT))) ||
+	    optname == IP_MULTICAST_TTL ||
+	    optname == IP_MULTICAST_LOOP) {
+		if (optlen >= sizeof(int)) {
+			if (get_user(val, (int __user *) optval))
+				return -EFAULT;
+		} else if (optlen >= sizeof(char)) {
+			unsigned char ucval;
+
+			if (get_user(ucval, (unsigned char __user *) optval))
+				return -EFAULT;
+			val = (int) ucval;
+		}
+	}
+
+	/* If optlen==0, it is equivalent to val == 0 */
+
+	if (ip_mroute_opt(optname))
+		return ip_mroute_setsockopt(sk,optname,optval,optlen);
+
+	err = 0;
+	lock_sock(sk);
+
+	switch (optname) {
+	case IP_OPTIONS:
+	{
+		struct ip_options * opt = NULL;
+		if (optlen > 40 || optlen < 0)
+			goto e_inval;
+		err = ip_options_get_from_user(sock_net(sk), &opt,
+					       optval, optlen);
+		if (err)
+			break;
+		if (inet->is_icsk) {
+			struct inet_connection_sock *icsk = inet_csk(sk);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+			if (sk->sk_family == PF_INET ||
+			    (!((1 << sk->sk_state) &
+			       (TCPF_LISTEN | TCPF_CLOSE)) &&
+			     inet->daddr != LOOPBACK4_IPV6)) {
+#endif
+				if (inet->opt)
+					icsk->icsk_ext_hdr_len -= inet->opt->optlen;
+				if (opt)
+					icsk->icsk_ext_hdr_len += opt->optlen;
+				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+			}
+#endif
+		}
+		opt = xchg(&inet->opt, opt);
+		kfree(opt);
+		break;
+	}
+	case IP_PKTINFO:
+		if (val)
+			inet->cmsg_flags |= IP_CMSG_PKTINFO;
+		else
+			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
+		break;
+	case IP_RECVTTL:
+		if (val)
+			inet->cmsg_flags |=  IP_CMSG_TTL;
+		else
+			inet->cmsg_flags &= ~IP_CMSG_TTL;
+		break;
+	case IP_RECVTOS:
+		if (val)
+			inet->cmsg_flags |=  IP_CMSG_TOS;
+		else
+			inet->cmsg_flags &= ~IP_CMSG_TOS;
+		break;
+	case IP_RECVOPTS:
+		if (val)
+			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
+		else
+			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
+		break;
+	case IP_RETOPTS:
+		if (val)
+			inet->cmsg_flags |= IP_CMSG_RETOPTS;
+		else
+			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
+		break;
+	case IP_PASSSEC:
+		if (val)
+			inet->cmsg_flags |= IP_CMSG_PASSSEC;
+		else
+			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
+		break;
+	case IP_TOS:	/* This sets both TOS and Precedence */
+		if (sk->sk_type == SOCK_STREAM) {
+			val &= ~3;
+			val |= inet->tos & 3;
+		}
+		if (inet->tos != val) {
+			inet->tos = val;
+			sk->sk_priority = rt_tos2priority(val);
+			sk_dst_reset(sk);
+		}
+		break;
+	case IP_TTL:
+		if (optlen<1)
+			goto e_inval;
+		if (val != -1 && (val < 1 || val>255))
+			goto e_inval;
+		inet->uc_ttl = val;
+		break;
+	case IP_HDRINCL:
+		if (sk->sk_type != SOCK_RAW) {
+			err = -ENOPROTOOPT;
+			break;
+		}
+		inet->hdrincl = val ? 1 : 0;
+		break;
+	case IP_MTU_DISCOVER:
+		if (val<0 || val>3)
+			goto e_inval;
+		inet->pmtudisc = val;
+		break;
+	case IP_RECVERR:
+		inet->recverr = !!val;
+		if (!val)
+			skb_queue_purge(&sk->sk_error_queue);
+		break;
+	case IP_MULTICAST_TTL:
+		if (sk->sk_type == SOCK_STREAM)
+			goto e_inval;
+		if (optlen<1)
+			goto e_inval;
+		if (val==-1)
+			val = 1;
+		if (val < 0 || val > 255)
+			goto e_inval;
+		inet->mc_ttl = val;
+		break;
+	case IP_MULTICAST_LOOP:
+		if (optlen<1)
+			goto e_inval;
+		inet->mc_loop = !!val;
+		break;
+	case IP_MULTICAST_IF:
+	{
+		struct ip_mreqn mreq;
+		struct net_device *dev = NULL;
+
+		if (sk->sk_type == SOCK_STREAM)
+			goto e_inval;
+		/*
+		 *	Check the arguments are allowable
+		 */
+
+		err = -EFAULT;
+		if (optlen >= sizeof(struct ip_mreqn)) {
+			if (copy_from_user(&mreq,optval,sizeof(mreq)))
+				break;
+		} else {
+			memset(&mreq, 0, sizeof(mreq));
+			if (optlen >= sizeof(struct in_addr) &&
+			    copy_from_user(&mreq.imr_address,optval,sizeof(struct in_addr)))
+				break;
+		}
+
+		if (!mreq.imr_ifindex) {
+			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
+				inet->mc_index = 0;
+				inet->mc_addr  = 0;
+				err = 0;
+				break;
+			}
+			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
+			if (dev) {
+				mreq.imr_ifindex = dev->ifindex;
+				dev_put(dev);
+			}
+		} else
+			dev = __dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
+
+
+		err = -EADDRNOTAVAIL;
+		if (!dev)
+			break;
+
+		err = -EINVAL;
+		if (sk->sk_bound_dev_if &&
+		    mreq.imr_ifindex != sk->sk_bound_dev_if)
+			break;
+
+		inet->mc_index = mreq.imr_ifindex;
+		inet->mc_addr  = mreq.imr_address.s_addr;
+		err = 0;
+		break;
+	}
+
+	case IP_ADD_MEMBERSHIP:
+	case IP_DROP_MEMBERSHIP:
+	{
+		struct ip_mreqn mreq;
+
+		err = -EPROTO;
+		if (inet_sk(sk)->is_icsk)
+			break;
+
+		if (optlen < sizeof(struct ip_mreq))
+			goto e_inval;
+		err = -EFAULT;
+		if (optlen >= sizeof(struct ip_mreqn)) {
+			if (copy_from_user(&mreq,optval,sizeof(mreq)))
+				break;
+		} else {
+			memset(&mreq, 0, sizeof(mreq));
+			if (copy_from_user(&mreq,optval,sizeof(struct ip_mreq)))
+				break;
+		}
+
+		if (optname == IP_ADD_MEMBERSHIP)
+			err = ip_mc_join_group(sk, &mreq);
+		else
+			err = ip_mc_leave_group(sk, &mreq);
+		break;
+	}
+	case IP_MSFILTER:
+	{
+		extern int sysctl_igmp_max_msf;
+		struct ip_msfilter *msf;
+
+		if (optlen < IP_MSFILTER_SIZE(0))
+			goto e_inval;
+		if (optlen > sysctl_optmem_max) {
+			err = -ENOBUFS;
+			break;
+		}
+		msf = kmalloc(optlen, GFP_KERNEL);
+		if (!msf) {
+			err = -ENOBUFS;
+			break;
+		}
+		err = -EFAULT;
+		if (copy_from_user(msf, optval, optlen)) {
+			kfree(msf);
+			break;
+		}
+		/* numsrc >= (1G-4) overflow in 32 bits */
+		if (msf->imsf_numsrc >= 0x3ffffffcU ||
+		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
+			kfree(msf);
+			err = -ENOBUFS;
+			break;
+		}
+		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
+			kfree(msf);
+			err = -EINVAL;
+			break;
+		}
+		err = ip_mc_msfilter(sk, msf, 0);
+		kfree(msf);
+		break;
+	}
+	case IP_BLOCK_SOURCE:
+	case IP_UNBLOCK_SOURCE:
+	case IP_ADD_SOURCE_MEMBERSHIP:
+	case IP_DROP_SOURCE_MEMBERSHIP:
+	{
+		struct ip_mreq_source mreqs;
+		int omode, add;
+
+		if (optlen != sizeof(struct ip_mreq_source))
+			goto e_inval;
+		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
+			err = -EFAULT;
+			break;
+		}
+		if (optname == IP_BLOCK_SOURCE) {
+			omode = MCAST_EXCLUDE;
+			add = 1;
+		} else if (optname == IP_UNBLOCK_SOURCE) {
+			omode = MCAST_EXCLUDE;
+			add = 0;
+		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
+			struct ip_mreqn mreq;
+
+			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
+			mreq.imr_address.s_addr = mreqs.imr_interface;
+			mreq.imr_ifindex = 0;
+			err = ip_mc_join_group(sk, &mreq);
+			if (err && err != -EADDRINUSE)
+				break;
+			omode = MCAST_INCLUDE;
+			add = 1;
+		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
+			omode = MCAST_INCLUDE;
+			add = 0;
+		}
+		err = ip_mc_source(add, omode, sk, &mreqs, 0);
+		break;
+	}
+	case MCAST_JOIN_GROUP:
+	case MCAST_LEAVE_GROUP:
+	{
+		struct group_req greq;
+		struct sockaddr_in *psin;
+		struct ip_mreqn mreq;
+
+		if (optlen < sizeof(struct group_req))
+			goto e_inval;
+		err = -EFAULT;
+		if (copy_from_user(&greq, optval, sizeof(greq)))
+			break;
+		psin = (struct sockaddr_in *)&greq.gr_group;
+		if (psin->sin_family != AF_INET)
+			goto e_inval;
+		memset(&mreq, 0, sizeof(mreq));
+		mreq.imr_multiaddr = psin->sin_addr;
+		mreq.imr_ifindex = greq.gr_interface;
+
+		if (optname == MCAST_JOIN_GROUP)
+			err = ip_mc_join_group(sk, &mreq);
+		else
+			err = ip_mc_leave_group(sk, &mreq);
+		break;
+	}
+	case MCAST_JOIN_SOURCE_GROUP:
+	case MCAST_LEAVE_SOURCE_GROUP:
+	case MCAST_BLOCK_SOURCE:
+	case MCAST_UNBLOCK_SOURCE:
+	{
+		struct group_source_req greqs;
+		struct ip_mreq_source mreqs;
+		struct sockaddr_in *psin;
+		int omode, add;
+
+		if (optlen != sizeof(struct group_source_req))
+			goto e_inval;
+		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
+			err = -EFAULT;
+			break;
+		}
+		if (greqs.gsr_group.ss_family != AF_INET ||
+		    greqs.gsr_source.ss_family != AF_INET) {
+			err = -EADDRNOTAVAIL;
+			break;
+		}
+		psin = (struct sockaddr_in *)&greqs.gsr_group;
+		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
+		psin = (struct sockaddr_in *)&greqs.gsr_source;
+		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
+		mreqs.imr_interface = 0; /* use index for mc_source */
+
+		if (optname == MCAST_BLOCK_SOURCE) {
+			omode = MCAST_EXCLUDE;
+			add = 1;
+		} else if (optname == MCAST_UNBLOCK_SOURCE) {
+			omode = MCAST_EXCLUDE;
+			add = 0;
+		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
+			struct ip_mreqn mreq;
+
+			psin = (struct sockaddr_in *)&greqs.gsr_group;
+			mreq.imr_multiaddr = psin->sin_addr;
+			mreq.imr_address.s_addr = 0;
+			mreq.imr_ifindex = greqs.gsr_interface;
+			err = ip_mc_join_group(sk, &mreq);
+			if (err && err != -EADDRINUSE)
+				break;
+			greqs.gsr_interface = mreq.imr_ifindex;
+			omode = MCAST_INCLUDE;
+			add = 1;
+		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
+			omode = MCAST_INCLUDE;
+			add = 0;
+		}
+		err = ip_mc_source(add, omode, sk, &mreqs,
+				   greqs.gsr_interface);
+		break;
+	}
+	case MCAST_MSFILTER:
+	{
+		extern int sysctl_igmp_max_msf;
+		struct sockaddr_in *psin;
+		struct ip_msfilter *msf = NULL;
+		struct group_filter *gsf = NULL;
+		int msize, i, ifindex;
+
+		if (optlen < GROUP_FILTER_SIZE(0))
+			goto e_inval;
+		if (optlen > sysctl_optmem_max) {
+			err = -ENOBUFS;
+			break;
+		}
+		gsf = kmalloc(optlen,GFP_KERNEL);
+		if (!gsf) {
+			err = -ENOBUFS;
+			break;
+		}
+		err = -EFAULT;
+		if (copy_from_user(gsf, optval, optlen)) {
+			goto mc_msf_out;
+		}
+		/* numsrc >= (4G-140)/128 overflow in 32 bits */
+		if (gsf->gf_numsrc >= 0x1ffffff ||
+		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
+			err = -ENOBUFS;
+			goto mc_msf_out;
+		}
+		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
+			err = -EINVAL;
+			goto mc_msf_out;
+		}
+		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
+		msf = kmalloc(msize,GFP_KERNEL);
+		if (!msf) {
+			err = -ENOBUFS;
+			goto mc_msf_out;
+		}
+		ifindex = gsf->gf_interface;
+		psin = (struct sockaddr_in *)&gsf->gf_group;
+		if (psin->sin_family != AF_INET) {
+			err = -EADDRNOTAVAIL;
+			goto mc_msf_out;
+		}
+		msf->imsf_multiaddr = psin->sin_addr.s_addr;
+		msf->imsf_interface = 0;
+		msf->imsf_fmode = gsf->gf_fmode;
+		msf->imsf_numsrc = gsf->gf_numsrc;
+		err = -EADDRNOTAVAIL;
+		for (i=0; i<gsf->gf_numsrc; ++i) {
+			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
+
+			if (psin->sin_family != AF_INET)
+				goto mc_msf_out;
+			msf->imsf_slist[i] = psin->sin_addr.s_addr;
+		}
+		kfree(gsf);
+		gsf = NULL;
+
+		err = ip_mc_msfilter(sk, msf, ifindex);
+	mc_msf_out:
+		kfree(msf);
+		kfree(gsf);
+		break;
+	}
+	case IP_ROUTER_ALERT:
+		err = ip_ra_control(sk, val ? 1 : 0, NULL);
+		break;
+
+	case IP_FREEBIND:
+		if (optlen<1)
+			goto e_inval;
+		inet->freebind = !!val;
+		break;
+
+	case IP_IPSEC_POLICY:
+	case IP_XFRM_POLICY:
+		err = -EPERM;
+		if (!capable(CAP_NET_ADMIN))
+			break;
+		err = xfrm_user_policy(sk, optname, optval, optlen);
+		break;
+
+	case IP_TRANSPARENT:
+		if (!capable(CAP_NET_ADMIN)) {
+			err = -EPERM;
+			break;
+		}
+		if (optlen < 1)
+			goto e_inval;
+		inet->transparent = !!val;
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+	release_sock(sk);
+	return err;
+
+e_inval:
+	release_sock(sk);
+	return -EINVAL;
+}
+
+int ip_setsockopt(struct sock *sk, int level,
+		int optname, char __user *optval, int optlen)
+{
+	int err;
+
+	if (level != SOL_IP)
+		return -ENOPROTOOPT;
+
+	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
+#ifdef CONFIG_NETFILTER
+	/* we need to exclude all possible ENOPROTOOPTs except default case */
+	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
+			optname != IP_IPSEC_POLICY &&
+			optname != IP_XFRM_POLICY &&
+			!ip_mroute_opt(optname)) {
+		lock_sock(sk);
+		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
+		release_sock(sk);
+	}
+#endif
+	return err;
+}
+
+#ifdef CONFIG_COMPAT
+int compat_ip_setsockopt(struct sock *sk, int level, int optname,
+			 char __user *optval, int optlen)
+{
+	int err;
+
+	if (level != SOL_IP)
+		return -ENOPROTOOPT;
+
+	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
+		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
+			ip_setsockopt);
+
+	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
+#ifdef CONFIG_NETFILTER
+	/* we need to exclude all possible ENOPROTOOPTs except default case */
+	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
+			optname != IP_IPSEC_POLICY &&
+			optname != IP_XFRM_POLICY &&
+			!ip_mroute_opt(optname)) {
+		lock_sock(sk);
+		err = compat_nf_setsockopt(sk, PF_INET, optname,
+					   optval, optlen);
+		release_sock(sk);
+	}
+#endif
+	return err;
+}
+
+EXPORT_SYMBOL(compat_ip_setsockopt);
+#endif
+
+/*
+ *	Get the options. Note for future reference. The GET of IP options gets the
+ *	_received_ ones. The set sets the _sent_ ones.
+ */
+
+static int do_ip_getsockopt(struct sock *sk, int level, int optname,
+			    char __user *optval, int __user *optlen)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	int val;
+	int len;
+
+	if (level != SOL_IP)
+		return -EOPNOTSUPP;
+
+	if (ip_mroute_opt(optname))
+		return ip_mroute_getsockopt(sk,optname,optval,optlen);
+
+	if (get_user(len,optlen))
+		return -EFAULT;
+	if (len < 0)
+		return -EINVAL;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case IP_OPTIONS:
+	{
+		unsigned char optbuf[sizeof(struct ip_options)+40];
+		struct ip_options * opt = (struct ip_options*)optbuf;
+		opt->optlen = 0;
+		if (inet->opt)
+			memcpy(optbuf, inet->opt,
+			       sizeof(struct ip_options)+
+			       inet->opt->optlen);
+		release_sock(sk);
+
+		if (opt->optlen == 0)
+			return put_user(0, optlen);
+
+		ip_options_undo(opt);
+
+		len = min_t(unsigned int, len, opt->optlen);
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval, opt->__data, len))
+			return -EFAULT;
+		return 0;
+	}
+	case IP_PKTINFO:
+		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
+		break;
+	case IP_RECVTTL:
+		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
+		break;
+	case IP_RECVTOS:
+		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
+		break;
+	case IP_RECVOPTS:
+		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
+		break;
+	case IP_RETOPTS:
+		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
+		break;
+	case IP_PASSSEC:
+		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
+		break;
+	case IP_TOS:
+		val = inet->tos;
+		break;
+	case IP_TTL:
+		val = (inet->uc_ttl == -1 ?
+		       sysctl_ip_default_ttl :
+		       inet->uc_ttl);
+		break;
+	case IP_HDRINCL:
+		val = inet->hdrincl;
+		break;
+	case IP_MTU_DISCOVER:
+		val = inet->pmtudisc;
+		break;
+	case IP_MTU:
+	{
+		struct dst_entry *dst;
+		val = 0;
+		dst = sk_dst_get(sk);
+		if (dst) {
+			val = dst_mtu(dst);
+			dst_release(dst);
+		}
+		if (!val) {
+			release_sock(sk);
+			return -ENOTCONN;
+		}
+		break;
+	}
+	case IP_RECVERR:
+		val = inet->recverr;
+		break;
+	case IP_MULTICAST_TTL:
+		val = inet->mc_ttl;
+		break;
+	case IP_MULTICAST_LOOP:
+		val = inet->mc_loop;
+		break;
+	case IP_MULTICAST_IF:
+	{
+		struct in_addr addr;
+		len = min_t(unsigned int, len, sizeof(struct in_addr));
+		addr.s_addr = inet->mc_addr;
+		release_sock(sk);
+
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval, &addr, len))
+			return -EFAULT;
+		return 0;
+	}
+	case IP_MSFILTER:
+	{
+		struct ip_msfilter msf;
+		int err;
+
+		if (len < IP_MSFILTER_SIZE(0)) {
+			release_sock(sk);
+			return -EINVAL;
+		}
+		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
+			release_sock(sk);
+			return -EFAULT;
+		}
+		err = ip_mc_msfget(sk, &msf,
+				   (struct ip_msfilter __user *)optval, optlen);
+		release_sock(sk);
+		return err;
+	}
+	case MCAST_MSFILTER:
+	{
+		struct group_filter gsf;
+		int err;
+
+		if (len < GROUP_FILTER_SIZE(0)) {
+			release_sock(sk);
+			return -EINVAL;
+		}
+		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
+			release_sock(sk);
+			return -EFAULT;
+		}
+		err = ip_mc_gsfget(sk, &gsf,
+				   (struct group_filter __user *)optval, optlen);
+		release_sock(sk);
+		return err;
+	}
+	case IP_PKTOPTIONS:
+	{
+		struct msghdr msg;
+
+		release_sock(sk);
+
+		if (sk->sk_type != SOCK_STREAM)
+			return -ENOPROTOOPT;
+
+		msg.msg_control = optval;
+		msg.msg_controllen = len;
+		msg.msg_flags = 0;
+
+		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
+			struct in_pktinfo info;
+
+			info.ipi_addr.s_addr = inet->rcv_saddr;
+			info.ipi_spec_dst.s_addr = inet->rcv_saddr;
+			info.ipi_ifindex = inet->mc_index;
+			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
+		}
+		if (inet->cmsg_flags & IP_CMSG_TTL) {
+			int hlim = inet->mc_ttl;
+			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
+		}
+		len -= msg.msg_controllen;
+		return put_user(len, optlen);
+	}
+	case IP_FREEBIND:
+		val = inet->freebind;
+		break;
+	case IP_TRANSPARENT:
+		val = inet->transparent;
+		break;
+	default:
+		release_sock(sk);
+		return -ENOPROTOOPT;
+	}
+	release_sock(sk);
+
+	if (len < sizeof(int) && len > 0 && val>=0 && val<=255) {
+		unsigned char ucval = (unsigned char)val;
+		len = 1;
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval,&ucval,1))
+			return -EFAULT;
+	} else {
+		len = min_t(unsigned int, sizeof(int), len);
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval,&val,len))
+			return -EFAULT;
+	}
+	return 0;
+}
+
+int ip_getsockopt(struct sock *sk, int level,
+		  int optname, char __user *optval, int __user *optlen)
+{
+	int err;
+
+	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
+#ifdef CONFIG_NETFILTER
+	/* we need to exclude all possible ENOPROTOOPTs except default case */
+	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
+			!ip_mroute_opt(optname)) {
+		int len;
+
+		if (get_user(len,optlen))
+			return -EFAULT;
+
+		lock_sock(sk);
+		err = nf_getsockopt(sk, PF_INET, optname, optval,
+				&len);
+		release_sock(sk);
+		if (err >= 0)
+			err = put_user(len, optlen);
+		return err;
+	}
+#endif
+	return err;
+}
+
+#ifdef CONFIG_COMPAT
+int compat_ip_getsockopt(struct sock *sk, int level, int optname,
+			 char __user *optval, int __user *optlen)
+{
+	int err;
+
+	if (optname == MCAST_MSFILTER)
+		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
+			ip_getsockopt);
+
+	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
+
+#ifdef CONFIG_NETFILTER
+	/* we need to exclude all possible ENOPROTOOPTs except default case */
+	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
+			!ip_mroute_opt(optname)) {
+		int len;
+
+		if (get_user(len, optlen))
+			return -EFAULT;
+
+		lock_sock(sk);
+		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
+		release_sock(sk);
+		if (err >= 0)
+			err = put_user(len, optlen);
+		return err;
+	}
+#endif
+	return err;
+}
+
+EXPORT_SYMBOL(compat_ip_getsockopt);
+#endif
+
+EXPORT_SYMBOL(ip_cmsg_recv);
+
+EXPORT_SYMBOL(ip_getsockopt);
+EXPORT_SYMBOL(ip_setsockopt);
diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
new file mode 100644
index 0000000..38ccb6d
--- /dev/null
+++ b/net/ipv4/ipcomp.c
@@ -0,0 +1,184 @@
+/*
+ * IP Payload Compression Protocol (IPComp) - RFC3173.
+ *
+ * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Todo:
+ *   - Tunable compression parameters.
+ *   - Compression stats.
+ *   - Adaptive compression.
+ */
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/rtnetlink.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/icmp.h>
+#include <net/ipcomp.h>
+#include <net/protocol.h>
+#include <net/sock.h>
+
+static void ipcomp4_err(struct sk_buff *skb, u32 info)
+{
+	__be32 spi;
+	struct iphdr *iph = (struct iphdr *)skb->data;
+	struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
+	struct xfrm_state *x;
+
+	if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
+	    icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
+		return;
+
+	spi = htonl(ntohs(ipch->cpi));
+	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr,
+			      spi, IPPROTO_COMP, AF_INET);
+	if (!x)
+		return;
+	NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIPQUAD_FMT "\n",
+		 spi, NIPQUAD(iph->daddr));
+	xfrm_state_put(x);
+}
+
+/* We always hold one tunnel user reference to indicate a tunnel */
+static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
+{
+	struct xfrm_state *t;
+
+	t = xfrm_state_alloc();
+	if (t == NULL)
+		goto out;
+
+	t->id.proto = IPPROTO_IPIP;
+	t->id.spi = x->props.saddr.a4;
+	t->id.daddr.a4 = x->id.daddr.a4;
+	memcpy(&t->sel, &x->sel, sizeof(t->sel));
+	t->props.family = AF_INET;
+	t->props.mode = x->props.mode;
+	t->props.saddr.a4 = x->props.saddr.a4;
+	t->props.flags = x->props.flags;
+
+	if (xfrm_init_state(t))
+		goto error;
+
+	atomic_set(&t->tunnel_users, 1);
+out:
+	return t;
+
+error:
+	t->km.state = XFRM_STATE_DEAD;
+	xfrm_state_put(t);
+	t = NULL;
+	goto out;
+}
+
+/*
+ * Must be protected by xfrm_cfg_mutex.  State and tunnel user references are
+ * always incremented on success.
+ */
+static int ipcomp_tunnel_attach(struct xfrm_state *x)
+{
+	int err = 0;
+	struct xfrm_state *t;
+
+	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr.a4,
+			      x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
+	if (!t) {
+		t = ipcomp_tunnel_create(x);
+		if (!t) {
+			err = -EINVAL;
+			goto out;
+		}
+		xfrm_state_insert(t);
+		xfrm_state_hold(t);
+	}
+	x->tunnel = t;
+	atomic_inc(&t->tunnel_users);
+out:
+	return err;
+}
+
+static int ipcomp4_init_state(struct xfrm_state *x)
+{
+	int err = -EINVAL;
+
+	x->props.header_len = 0;
+	switch (x->props.mode) {
+	case XFRM_MODE_TRANSPORT:
+		break;
+	case XFRM_MODE_TUNNEL:
+		x->props.header_len += sizeof(struct iphdr);
+		break;
+	default:
+		goto out;
+	}
+
+	err = ipcomp_init_state(x);
+	if (err)
+		goto out;
+
+	if (x->props.mode == XFRM_MODE_TUNNEL) {
+		err = ipcomp_tunnel_attach(x);
+		if (err)
+			goto error_tunnel;
+	}
+
+	err = 0;
+out:
+	return err;
+
+error_tunnel:
+	ipcomp_destroy(x);
+	goto out;
+}
+
+static const struct xfrm_type ipcomp_type = {
+	.description	= "IPCOMP4",
+	.owner		= THIS_MODULE,
+	.proto	     	= IPPROTO_COMP,
+	.init_state	= ipcomp4_init_state,
+	.destructor	= ipcomp_destroy,
+	.input		= ipcomp_input,
+	.output		= ipcomp_output
+};
+
+static struct net_protocol ipcomp4_protocol = {
+	.handler	=	xfrm4_rcv,
+	.err_handler	=	ipcomp4_err,
+	.no_policy	=	1,
+};
+
+static int __init ipcomp4_init(void)
+{
+	if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
+		printk(KERN_INFO "ipcomp init: can't add xfrm type\n");
+		return -EAGAIN;
+	}
+	if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
+		printk(KERN_INFO "ipcomp init: can't add protocol\n");
+		xfrm_unregister_type(&ipcomp_type, AF_INET);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static void __exit ipcomp4_fini(void)
+{
+	if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0)
+		printk(KERN_INFO "ip ipcomp close: can't remove protocol\n");
+	if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
+		printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n");
+}
+
+module_init(ipcomp4_init);
+module_exit(ipcomp4_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
+MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
+
+MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
new file mode 100644
index 0000000..ff75000
--- /dev/null
+++ b/net/ipv4/ipconfig.c
@@ -0,0 +1,1538 @@
+/*
+ *  Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
+ *  user-supplied information to configure own IP address and routes.
+ *
+ *  Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
+ *
+ *  Derived from network configuration code in fs/nfs/nfsroot.c,
+ *  originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
+ *
+ *  BOOTP rewritten to construct and analyse packets itself instead
+ *  of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
+ *					     -- MJ, December 1998
+ *
+ *  Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
+ *  initialization scheme.
+ *	- Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
+ *
+ *  DHCP support added.  To users this looks like a whole separate
+ *  protocol, but we know it's just a bag on the side of BOOTP.
+ *		-- Chip Salzenberg <chip@valinux.com>, May 2000
+ *
+ *  Ported DHCP support from 2.2.16 to 2.4.0-test4
+ *              -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
+ *
+ *  Merged changes from 2.2.19 into 2.4.3
+ *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
+ *
+ *  Multiple Nameservers in /proc/net/pnp
+ *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/random.h>
+#include <linux/init.h>
+#include <linux/utsname.h>
+#include <linux/in.h>
+#include <linux/if.h>
+#include <linux/inet.h>
+#include <linux/inetdevice.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/socket.h>
+#include <linux/route.h>
+#include <linux/udp.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/major.h>
+#include <linux/root_dev.h>
+#include <linux/delay.h>
+#include <linux/nfs_fs.h>
+#include <net/net_namespace.h>
+#include <net/arp.h>
+#include <net/ip.h>
+#include <net/ipconfig.h>
+#include <net/route.h>
+
+#include <asm/uaccess.h>
+#include <net/checksum.h>
+#include <asm/processor.h>
+
+/* Define this to allow debugging output */
+#undef IPCONFIG_DEBUG
+
+#ifdef IPCONFIG_DEBUG
+#define DBG(x) printk x
+#else
+#define DBG(x) do { } while(0)
+#endif
+
+#if defined(CONFIG_IP_PNP_DHCP)
+#define IPCONFIG_DHCP
+#endif
+#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
+#define IPCONFIG_BOOTP
+#endif
+#if defined(CONFIG_IP_PNP_RARP)
+#define IPCONFIG_RARP
+#endif
+#if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
+#define IPCONFIG_DYNAMIC
+#endif
+
+/* Define the friendly delay before and after opening net devices */
+#define CONF_PRE_OPEN		500	/* Before opening: 1/2 second */
+#define CONF_POST_OPEN		1	/* After opening: 1 second */
+
+/* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
+#define CONF_OPEN_RETRIES 	2	/* (Re)open devices twice */
+#define CONF_SEND_RETRIES 	6	/* Send six requests per open */
+#define CONF_INTER_TIMEOUT	(HZ/2)	/* Inter-device timeout: 1/2 second */
+#define CONF_BASE_TIMEOUT	(HZ*2)	/* Initial timeout: 2 seconds */
+#define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
+#define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
+#define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
+#define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers
+					   - '3' from resolv.h */
+
+#define NONE __constant_htonl(INADDR_NONE)
+#define ANY __constant_htonl(INADDR_ANY)
+
+/*
+ * Public IP configuration
+ */
+
+/* This is used by platforms which might be able to set the ipconfig
+ * variables using firmware environment vars.  If this is set, it will
+ * ignore such firmware variables.
+ */
+int ic_set_manually __initdata = 0;		/* IPconfig parameters set manually */
+
+static int ic_enable __initdata = 0;		/* IP config enabled? */
+
+/* Protocol choice */
+int ic_proto_enabled __initdata = 0
+#ifdef IPCONFIG_BOOTP
+			| IC_BOOTP
+#endif
+#ifdef CONFIG_IP_PNP_DHCP
+			| IC_USE_DHCP
+#endif
+#ifdef IPCONFIG_RARP
+			| IC_RARP
+#endif
+			;
+
+static int ic_host_name_set __initdata = 0;	/* Host name set by us? */
+
+__be32 ic_myaddr = NONE;		/* My IP address */
+static __be32 ic_netmask = NONE;	/* Netmask for local subnet */
+__be32 ic_gateway = NONE;	/* Gateway IP address */
+
+__be32 ic_servaddr = NONE;	/* Boot server IP address */
+
+__be32 root_server_addr = NONE;	/* Address of NFS server */
+u8 root_server_path[256] = { 0, };	/* Path to mount as root */
+
+/* vendor class identifier */
+static char vendor_class_identifier[253] __initdata;
+
+/* Persistent data: */
+
+static int ic_proto_used;			/* Protocol used, if any */
+static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
+static u8 ic_domain[64];		/* DNS (not NIS) domain name */
+
+/*
+ * Private state.
+ */
+
+/* Name of user-selected boot device */
+static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
+
+/* Protocols supported by available interfaces */
+static int ic_proto_have_if __initdata = 0;
+
+#ifdef IPCONFIG_DYNAMIC
+static DEFINE_SPINLOCK(ic_recv_lock);
+static volatile int ic_got_reply __initdata = 0;    /* Proto(s) that replied */
+#endif
+#ifdef IPCONFIG_DHCP
+static int ic_dhcp_msgtype __initdata = 0;	/* DHCP msg type received */
+#endif
+
+
+/*
+ *	Network devices
+ */
+
+struct ic_device {
+	struct ic_device *next;
+	struct net_device *dev;
+	unsigned short flags;
+	short able;
+	__be32 xid;
+};
+
+static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
+static struct net_device *ic_dev __initdata = NULL;	/* Selected device */
+
+static int __init ic_open_devs(void)
+{
+	struct ic_device *d, **last;
+	struct net_device *dev;
+	unsigned short oflags;
+
+	last = &ic_first_dev;
+	rtnl_lock();
+
+	/* bring loopback device up first */
+	for_each_netdev(&init_net, dev) {
+		if (!(dev->flags & IFF_LOOPBACK))
+			continue;
+		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
+			printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
+	}
+
+	for_each_netdev(&init_net, dev) {
+		if (dev->flags & IFF_LOOPBACK)
+			continue;
+		if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
+		    (!(dev->flags & IFF_LOOPBACK) &&
+		     (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
+		     strncmp(dev->name, "dummy", 5))) {
+			int able = 0;
+			if (dev->mtu >= 364)
+				able |= IC_BOOTP;
+			else
+				printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
+			if (!(dev->flags & IFF_NOARP))
+				able |= IC_RARP;
+			able &= ic_proto_enabled;
+			if (ic_proto_enabled && !able)
+				continue;
+			oflags = dev->flags;
+			if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
+				printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
+				continue;
+			}
+			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
+				rtnl_unlock();
+				return -1;
+			}
+			d->dev = dev;
+			*last = d;
+			last = &d->next;
+			d->flags = oflags;
+			d->able = able;
+			if (able & IC_BOOTP)
+				get_random_bytes(&d->xid, sizeof(__be32));
+			else
+				d->xid = 0;
+			ic_proto_have_if |= able;
+			DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
+				dev->name, able, d->xid));
+		}
+	}
+	rtnl_unlock();
+
+	*last = NULL;
+
+	if (!ic_first_dev) {
+		if (user_dev_name[0])
+			printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
+		else
+			printk(KERN_ERR "IP-Config: No network devices available.\n");
+		return -1;
+	}
+	return 0;
+}
+
+static void __init ic_close_devs(void)
+{
+	struct ic_device *d, *next;
+	struct net_device *dev;
+
+	rtnl_lock();
+	next = ic_first_dev;
+	while ((d = next)) {
+		next = d->next;
+		dev = d->dev;
+		if (dev != ic_dev) {
+			DBG(("IP-Config: Downing %s\n", dev->name));
+			dev_change_flags(dev, d->flags);
+		}
+		kfree(d);
+	}
+	rtnl_unlock();
+}
+
+/*
+ *	Interface to various network functions.
+ */
+
+static inline void
+set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
+{
+	sin->sin_family = AF_INET;
+	sin->sin_addr.s_addr = addr;
+	sin->sin_port = port;
+}
+
+static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
+{
+	int res;
+
+	mm_segment_t oldfs = get_fs();
+	set_fs(get_ds());
+	res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
+	set_fs(oldfs);
+	return res;
+}
+
+static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
+{
+	int res;
+
+	mm_segment_t oldfs = get_fs();
+	set_fs(get_ds());
+	res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
+	set_fs(oldfs);
+	return res;
+}
+
+/*
+ *	Set up interface addresses and routes.
+ */
+
+static int __init ic_setup_if(void)
+{
+	struct ifreq ir;
+	struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
+	int err;
+
+	memset(&ir, 0, sizeof(ir));
+	strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
+	set_sockaddr(sin, ic_myaddr, 0);
+	if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
+		printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
+		return -1;
+	}
+	set_sockaddr(sin, ic_netmask, 0);
+	if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
+		printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
+		return -1;
+	}
+	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
+	if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
+		printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
+		return -1;
+	}
+	return 0;
+}
+
+static int __init ic_setup_routes(void)
+{
+	/* No need to setup device routes, only the default route... */
+
+	if (ic_gateway != NONE) {
+		struct rtentry rm;
+		int err;
+
+		memset(&rm, 0, sizeof(rm));
+		if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
+			printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
+			return -1;
+		}
+		set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
+		set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
+		set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
+		rm.rt_flags = RTF_UP | RTF_GATEWAY;
+		if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
+			printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ *	Fill in default values for all missing parameters.
+ */
+
+static int __init ic_defaults(void)
+{
+	/*
+	 *	At this point we have no userspace running so need not
+	 *	claim locks on system_utsname
+	 */
+
+	if (!ic_host_name_set)
+		sprintf(init_utsname()->nodename, NIPQUAD_FMT, NIPQUAD(ic_myaddr));
+
+	if (root_server_addr == NONE)
+		root_server_addr = ic_servaddr;
+
+	if (ic_netmask == NONE) {
+		if (IN_CLASSA(ntohl(ic_myaddr)))
+			ic_netmask = htonl(IN_CLASSA_NET);
+		else if (IN_CLASSB(ntohl(ic_myaddr)))
+			ic_netmask = htonl(IN_CLASSB_NET);
+		else if (IN_CLASSC(ntohl(ic_myaddr)))
+			ic_netmask = htonl(IN_CLASSC_NET);
+		else {
+			printk(KERN_ERR "IP-Config: Unable to guess netmask for address " NIPQUAD_FMT "\n",
+				NIPQUAD(ic_myaddr));
+			return -1;
+		}
+		printk("IP-Config: Guessing netmask " NIPQUAD_FMT "\n", NIPQUAD(ic_netmask));
+	}
+
+	return 0;
+}
+
+/*
+ *	RARP support.
+ */
+
+#ifdef IPCONFIG_RARP
+
+static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
+
+static struct packet_type rarp_packet_type __initdata = {
+	.type =	__constant_htons(ETH_P_RARP),
+	.func =	ic_rarp_recv,
+};
+
+static inline void __init ic_rarp_init(void)
+{
+	dev_add_pack(&rarp_packet_type);
+}
+
+static inline void __init ic_rarp_cleanup(void)
+{
+	dev_remove_pack(&rarp_packet_type);
+}
+
+/*
+ *  Process received RARP packet.
+ */
+static int __init
+ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct arphdr *rarp;
+	unsigned char *rarp_ptr;
+	__be32 sip, tip;
+	unsigned char *sha, *tha;		/* s for "source", t for "target" */
+	struct ic_device *d;
+
+	if (!net_eq(dev_net(dev), &init_net))
+		goto drop;
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
+		return NET_RX_DROP;
+
+	if (!pskb_may_pull(skb, sizeof(struct arphdr)))
+		goto drop;
+
+	/* Basic sanity checks can be done without the lock.  */
+	rarp = (struct arphdr *)skb_transport_header(skb);
+
+	/* If this test doesn't pass, it's not IP, or we should
+	 * ignore it anyway.
+	 */
+	if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
+		goto drop;
+
+	/* If it's not a RARP reply, delete it. */
+	if (rarp->ar_op != htons(ARPOP_RREPLY))
+		goto drop;
+
+	/* If it's not Ethernet, delete it. */
+	if (rarp->ar_pro != htons(ETH_P_IP))
+		goto drop;
+
+	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
+		goto drop;
+
+	/* OK, it is all there and looks valid, process... */
+	rarp = (struct arphdr *)skb_transport_header(skb);
+	rarp_ptr = (unsigned char *) (rarp + 1);
+
+	/* One reply at a time, please. */
+	spin_lock(&ic_recv_lock);
+
+	/* If we already have a reply, just drop the packet */
+	if (ic_got_reply)
+		goto drop_unlock;
+
+	/* Find the ic_device that the packet arrived on */
+	d = ic_first_dev;
+	while (d && d->dev != dev)
+		d = d->next;
+	if (!d)
+		goto drop_unlock;	/* should never happen */
+
+	/* Extract variable-width fields */
+	sha = rarp_ptr;
+	rarp_ptr += dev->addr_len;
+	memcpy(&sip, rarp_ptr, 4);
+	rarp_ptr += 4;
+	tha = rarp_ptr;
+	rarp_ptr += dev->addr_len;
+	memcpy(&tip, rarp_ptr, 4);
+
+	/* Discard packets which are not meant for us. */
+	if (memcmp(tha, dev->dev_addr, dev->addr_len))
+		goto drop_unlock;
+
+	/* Discard packets which are not from specified server. */
+	if (ic_servaddr != NONE && ic_servaddr != sip)
+		goto drop_unlock;
+
+	/* We have a winner! */
+	ic_dev = dev;
+	if (ic_myaddr == NONE)
+		ic_myaddr = tip;
+	ic_servaddr = sip;
+	ic_got_reply = IC_RARP;
+
+drop_unlock:
+	/* Show's over.  Nothing to see here.  */
+	spin_unlock(&ic_recv_lock);
+
+drop:
+	/* Throw the packet out. */
+	kfree_skb(skb);
+	return 0;
+}
+
+
+/*
+ *  Send RARP request packet over a single interface.
+ */
+static void __init ic_rarp_send_if(struct ic_device *d)
+{
+	struct net_device *dev = d->dev;
+	arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
+		 dev->dev_addr, dev->dev_addr);
+}
+#endif
+
+/*
+ *	DHCP/BOOTP support.
+ */
+
+#ifdef IPCONFIG_BOOTP
+
+struct bootp_pkt {		/* BOOTP packet format */
+	struct iphdr iph;	/* IP header */
+	struct udphdr udph;	/* UDP header */
+	u8 op;			/* 1=request, 2=reply */
+	u8 htype;		/* HW address type */
+	u8 hlen;		/* HW address length */
+	u8 hops;		/* Used only by gateways */
+	__be32 xid;		/* Transaction ID */
+	__be16 secs;		/* Seconds since we started */
+	__be16 flags;		/* Just what it says */
+	__be32 client_ip;		/* Client's IP address if known */
+	__be32 your_ip;		/* Assigned IP address */
+	__be32 server_ip;		/* (Next, e.g. NFS) Server's IP address */
+	__be32 relay_ip;		/* IP address of BOOTP relay */
+	u8 hw_addr[16];		/* Client's HW address */
+	u8 serv_name[64];	/* Server host name */
+	u8 boot_file[128];	/* Name of boot file */
+	u8 exten[312];		/* DHCP options / BOOTP vendor extensions */
+};
+
+/* packet ops */
+#define BOOTP_REQUEST	1
+#define BOOTP_REPLY	2
+
+/* DHCP message types */
+#define DHCPDISCOVER	1
+#define DHCPOFFER	2
+#define DHCPREQUEST	3
+#define DHCPDECLINE	4
+#define DHCPACK		5
+#define DHCPNAK		6
+#define DHCPRELEASE	7
+#define DHCPINFORM	8
+
+static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
+
+static struct packet_type bootp_packet_type __initdata = {
+	.type =	__constant_htons(ETH_P_IP),
+	.func =	ic_bootp_recv,
+};
+
+
+/*
+ *  Initialize DHCP/BOOTP extension fields in the request.
+ */
+
+static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
+
+#ifdef IPCONFIG_DHCP
+
+static void __init
+ic_dhcp_init_options(u8 *options)
+{
+	u8 mt = ((ic_servaddr == NONE)
+		 ? DHCPDISCOVER : DHCPREQUEST);
+	u8 *e = options;
+	int len;
+
+#ifdef IPCONFIG_DEBUG
+	printk("DHCP: Sending message type %d\n", mt);
+#endif
+
+	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
+	e += 4;
+
+	*e++ = 53;		/* DHCP message type */
+	*e++ = 1;
+	*e++ = mt;
+
+	if (mt == DHCPREQUEST) {
+		*e++ = 54;	/* Server ID (IP address) */
+		*e++ = 4;
+		memcpy(e, &ic_servaddr, 4);
+		e += 4;
+
+		*e++ = 50;	/* Requested IP address */
+		*e++ = 4;
+		memcpy(e, &ic_myaddr, 4);
+		e += 4;
+	}
+
+	/* always? */
+	{
+		static const u8 ic_req_params[] = {
+			1,	/* Subnet mask */
+			3,	/* Default gateway */
+			6,	/* DNS server */
+			12,	/* Host name */
+			15,	/* Domain name */
+			17,	/* Boot path */
+			40,	/* NIS domain name */
+		};
+
+		*e++ = 55;	/* Parameter request list */
+		*e++ = sizeof(ic_req_params);
+		memcpy(e, ic_req_params, sizeof(ic_req_params));
+		e += sizeof(ic_req_params);
+
+		if (*vendor_class_identifier) {
+			printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
+			       vendor_class_identifier);
+			*e++ = 60;	/* Class-identifier */
+			len = strlen(vendor_class_identifier);
+			*e++ = len;
+			memcpy(e, vendor_class_identifier, len);
+			e += len;
+		}
+	}
+
+	*e++ = 255;	/* End of the list */
+}
+
+#endif /* IPCONFIG_DHCP */
+
+static void __init ic_bootp_init_ext(u8 *e)
+{
+	memcpy(e, ic_bootp_cookie, 4);	/* RFC1048 Magic Cookie */
+	e += 4;
+	*e++ = 1;		/* Subnet mask request */
+	*e++ = 4;
+	e += 4;
+	*e++ = 3;		/* Default gateway request */
+	*e++ = 4;
+	e += 4;
+	*e++ = 5;		/* Name server request */
+	*e++ = 8;
+	e += 8;
+	*e++ = 12;		/* Host name request */
+	*e++ = 32;
+	e += 32;
+	*e++ = 40;		/* NIS Domain name request */
+	*e++ = 32;
+	e += 32;
+	*e++ = 17;		/* Boot path */
+	*e++ = 40;
+	e += 40;
+
+	*e++ = 57;		/* set extension buffer size for reply */
+	*e++ = 2;
+	*e++ = 1;		/* 128+236+8+20+14, see dhcpd sources */
+	*e++ = 150;
+
+	*e++ = 255;		/* End of the list */
+}
+
+
+/*
+ *  Initialize the DHCP/BOOTP mechanism.
+ */
+static inline void __init ic_bootp_init(void)
+{
+	int i;
+
+	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
+		ic_nameservers[i] = NONE;
+
+	dev_add_pack(&bootp_packet_type);
+}
+
+
+/*
+ *  DHCP/BOOTP cleanup.
+ */
+static inline void __init ic_bootp_cleanup(void)
+{
+	dev_remove_pack(&bootp_packet_type);
+}
+
+
+/*
+ *  Send DHCP/BOOTP request to single interface.
+ */
+static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
+{
+	struct net_device *dev = d->dev;
+	struct sk_buff *skb;
+	struct bootp_pkt *b;
+	struct iphdr *h;
+
+	/* Allocate packet */
+	skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
+			GFP_KERNEL);
+	if (!skb)
+		return;
+	skb_reserve(skb, LL_RESERVED_SPACE(dev));
+	b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
+	memset(b, 0, sizeof(struct bootp_pkt));
+
+	/* Construct IP header */
+	skb_reset_network_header(skb);
+	h = ip_hdr(skb);
+	h->version = 4;
+	h->ihl = 5;
+	h->tot_len = htons(sizeof(struct bootp_pkt));
+	h->frag_off = htons(IP_DF);
+	h->ttl = 64;
+	h->protocol = IPPROTO_UDP;
+	h->daddr = htonl(INADDR_BROADCAST);
+	h->check = ip_fast_csum((unsigned char *) h, h->ihl);
+
+	/* Construct UDP header */
+	b->udph.source = htons(68);
+	b->udph.dest = htons(67);
+	b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
+	/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
+
+	/* Construct DHCP/BOOTP header */
+	b->op = BOOTP_REQUEST;
+	if (dev->type < 256) /* check for false types */
+		b->htype = dev->type;
+	else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
+		b->htype = ARPHRD_IEEE802;
+	else if (dev->type == ARPHRD_FDDI)
+		b->htype = ARPHRD_ETHER;
+	else {
+		printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
+		b->htype = dev->type; /* can cause undefined behavior */
+	}
+
+	/* server_ip and your_ip address are both already zero per RFC2131 */
+	b->hlen = dev->addr_len;
+	memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
+	b->secs = htons(jiffies_diff / HZ);
+	b->xid = d->xid;
+
+	/* add DHCP options or BOOTP extensions */
+#ifdef IPCONFIG_DHCP
+	if (ic_proto_enabled & IC_USE_DHCP)
+		ic_dhcp_init_options(b->exten);
+	else
+#endif
+		ic_bootp_init_ext(b->exten);
+
+	/* Chain packet down the line... */
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_IP);
+	if (dev_hard_header(skb, dev, ntohs(skb->protocol),
+			    dev->broadcast, dev->dev_addr, skb->len) < 0 ||
+	    dev_queue_xmit(skb) < 0)
+		printk("E");
+}
+
+
+/*
+ *  Copy BOOTP-supplied string if not already set.
+ */
+static int __init ic_bootp_string(char *dest, char *src, int len, int max)
+{
+	if (!len)
+		return 0;
+	if (len > max-1)
+		len = max-1;
+	memcpy(dest, src, len);
+	dest[len] = '\0';
+	return 1;
+}
+
+
+/*
+ *  Process BOOTP extensions.
+ */
+static void __init ic_do_bootp_ext(u8 *ext)
+{
+       u8 servers;
+       int i;
+
+#ifdef IPCONFIG_DEBUG
+	u8 *c;
+
+	printk("DHCP/BOOTP: Got extension %d:",*ext);
+	for (c=ext+2; c<ext+2+ext[1]; c++)
+		printk(" %02x", *c);
+	printk("\n");
+#endif
+
+	switch (*ext++) {
+		case 1:		/* Subnet mask */
+			if (ic_netmask == NONE)
+				memcpy(&ic_netmask, ext+1, 4);
+			break;
+		case 3:		/* Default gateway */
+			if (ic_gateway == NONE)
+				memcpy(&ic_gateway, ext+1, 4);
+			break;
+		case 6:		/* DNS server */
+			servers= *ext/4;
+			if (servers > CONF_NAMESERVERS_MAX)
+				servers = CONF_NAMESERVERS_MAX;
+			for (i = 0; i < servers; i++) {
+				if (ic_nameservers[i] == NONE)
+					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
+			}
+			break;
+		case 12:	/* Host name */
+			ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
+			ic_host_name_set = 1;
+			break;
+		case 15:	/* Domain name (DNS) */
+			ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
+			break;
+		case 17:	/* Root path */
+			if (!root_server_path[0])
+				ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
+			break;
+		case 40:	/* NIS Domain name (_not_ DNS) */
+			ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
+			break;
+	}
+}
+
+
+/*
+ *  Receive BOOTP reply.
+ */
+static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
+{
+	struct bootp_pkt *b;
+	struct iphdr *h;
+	struct ic_device *d;
+	int len, ext_len;
+
+	if (!net_eq(dev_net(dev), &init_net))
+		goto drop;
+
+	/* Perform verifications before taking the lock.  */
+	if (skb->pkt_type == PACKET_OTHERHOST)
+		goto drop;
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
+		return NET_RX_DROP;
+
+	if (!pskb_may_pull(skb,
+			   sizeof(struct iphdr) +
+			   sizeof(struct udphdr)))
+		goto drop;
+
+	b = (struct bootp_pkt *)skb_network_header(skb);
+	h = &b->iph;
+
+	if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
+		goto drop;
+
+	/* Fragments are not supported */
+	if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
+		if (net_ratelimit())
+			printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
+			       "reply.\n");
+		goto drop;
+	}
+
+	if (skb->len < ntohs(h->tot_len))
+		goto drop;
+
+	if (ip_fast_csum((char *) h, h->ihl))
+		goto drop;
+
+	if (b->udph.source != htons(67) || b->udph.dest != htons(68))
+		goto drop;
+
+	if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
+		goto drop;
+
+	len = ntohs(b->udph.len) - sizeof(struct udphdr);
+	ext_len = len - (sizeof(*b) -
+			 sizeof(struct iphdr) -
+			 sizeof(struct udphdr) -
+			 sizeof(b->exten));
+	if (ext_len < 0)
+		goto drop;
+
+	/* Ok the front looks good, make sure we can get at the rest.  */
+	if (!pskb_may_pull(skb, skb->len))
+		goto drop;
+
+	b = (struct bootp_pkt *)skb_network_header(skb);
+	h = &b->iph;
+
+	/* One reply at a time, please. */
+	spin_lock(&ic_recv_lock);
+
+	/* If we already have a reply, just drop the packet */
+	if (ic_got_reply)
+		goto drop_unlock;
+
+	/* Find the ic_device that the packet arrived on */
+	d = ic_first_dev;
+	while (d && d->dev != dev)
+		d = d->next;
+	if (!d)
+		goto drop_unlock;  /* should never happen */
+
+	/* Is it a reply to our BOOTP request? */
+	if (b->op != BOOTP_REPLY ||
+	    b->xid != d->xid) {
+		if (net_ratelimit())
+			printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
+			       "op[%x] xid[%x]\n",
+			       b->op, b->xid);
+		goto drop_unlock;
+	}
+
+	/* Parse extensions */
+	if (ext_len >= 4 &&
+	    !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
+		u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
+		u8 *ext;
+
+#ifdef IPCONFIG_DHCP
+		if (ic_proto_enabled & IC_USE_DHCP) {
+			__be32 server_id = NONE;
+			int mt = 0;
+
+			ext = &b->exten[4];
+			while (ext < end && *ext != 0xff) {
+				u8 *opt = ext++;
+				if (*opt == 0)	/* Padding */
+					continue;
+				ext += *ext + 1;
+				if (ext >= end)
+					break;
+				switch (*opt) {
+				case 53:	/* Message type */
+					if (opt[1])
+						mt = opt[2];
+					break;
+				case 54:	/* Server ID (IP address) */
+					if (opt[1] >= 4)
+						memcpy(&server_id, opt + 2, 4);
+					break;
+				}
+			}
+
+#ifdef IPCONFIG_DEBUG
+			printk("DHCP: Got message type %d\n", mt);
+#endif
+
+			switch (mt) {
+			case DHCPOFFER:
+				/* While in the process of accepting one offer,
+				 * ignore all others.
+				 */
+				if (ic_myaddr != NONE)
+					goto drop_unlock;
+
+				/* Let's accept that offer. */
+				ic_myaddr = b->your_ip;
+				ic_servaddr = server_id;
+#ifdef IPCONFIG_DEBUG
+				printk("DHCP: Offered address " NIPQUAD_FMT,
+				       NIPQUAD(ic_myaddr));
+				printk(" by server " NIPQUAD_FMT "\n",
+				       NIPQUAD(ic_servaddr));
+#endif
+				/* The DHCP indicated server address takes
+				 * precedence over the bootp header one if
+				 * they are different.
+				 */
+				if ((server_id != NONE) &&
+				    (b->server_ip != server_id))
+					b->server_ip = ic_servaddr;
+				break;
+
+			case DHCPACK:
+				if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
+					goto drop_unlock;
+
+				/* Yeah! */
+				break;
+
+			default:
+				/* Urque.  Forget it*/
+				ic_myaddr = NONE;
+				ic_servaddr = NONE;
+				goto drop_unlock;
+			}
+
+			ic_dhcp_msgtype = mt;
+
+		}
+#endif /* IPCONFIG_DHCP */
+
+		ext = &b->exten[4];
+		while (ext < end && *ext != 0xff) {
+			u8 *opt = ext++;
+			if (*opt == 0)	/* Padding */
+				continue;
+			ext += *ext + 1;
+			if (ext < end)
+				ic_do_bootp_ext(opt);
+		}
+	}
+
+	/* We have a winner! */
+	ic_dev = dev;
+	ic_myaddr = b->your_ip;
+	ic_servaddr = b->server_ip;
+	if (ic_gateway == NONE && b->relay_ip)
+		ic_gateway = b->relay_ip;
+	if (ic_nameservers[0] == NONE)
+		ic_nameservers[0] = ic_servaddr;
+	ic_got_reply = IC_BOOTP;
+
+drop_unlock:
+	/* Show's over.  Nothing to see here.  */
+	spin_unlock(&ic_recv_lock);
+
+drop:
+	/* Throw the packet out. */
+	kfree_skb(skb);
+
+	return 0;
+}
+
+
+#endif
+
+
+/*
+ *	Dynamic IP configuration -- DHCP, BOOTP, RARP.
+ */
+
+#ifdef IPCONFIG_DYNAMIC
+
+static int __init ic_dynamic(void)
+{
+	int retries;
+	struct ic_device *d;
+	unsigned long start_jiffies, timeout, jiff;
+	int do_bootp = ic_proto_have_if & IC_BOOTP;
+	int do_rarp = ic_proto_have_if & IC_RARP;
+
+	/*
+	 * If none of DHCP/BOOTP/RARP was selected, return with an error.
+	 * This routine gets only called when some pieces of information
+	 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
+	 */
+	if (!ic_proto_enabled) {
+		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
+		return -1;
+	}
+
+#ifdef IPCONFIG_BOOTP
+	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
+		printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
+#endif
+#ifdef IPCONFIG_RARP
+	if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
+		printk(KERN_ERR "RARP: No suitable device found.\n");
+#endif
+
+	if (!ic_proto_have_if)
+		/* Error message already printed */
+		return -1;
+
+	/*
+	 * Setup protocols
+	 */
+#ifdef IPCONFIG_BOOTP
+	if (do_bootp)
+		ic_bootp_init();
+#endif
+#ifdef IPCONFIG_RARP
+	if (do_rarp)
+		ic_rarp_init();
+#endif
+
+	/*
+	 * Send requests and wait, until we get an answer. This loop
+	 * seems to be a terrible waste of CPU time, but actually there is
+	 * only one process running at all, so we don't need to use any
+	 * scheduler functions.
+	 * [Actually we could now, but the nothing else running note still
+	 *  applies.. - AC]
+	 */
+	printk(KERN_NOTICE "Sending %s%s%s requests .",
+	       do_bootp
+		? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
+	       (do_bootp && do_rarp) ? " and " : "",
+	       do_rarp ? "RARP" : "");
+
+	start_jiffies = jiffies;
+	d = ic_first_dev;
+	retries = CONF_SEND_RETRIES;
+	get_random_bytes(&timeout, sizeof(timeout));
+	timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
+	for (;;) {
+#ifdef IPCONFIG_BOOTP
+		if (do_bootp && (d->able & IC_BOOTP))
+			ic_bootp_send_if(d, jiffies - start_jiffies);
+#endif
+#ifdef IPCONFIG_RARP
+		if (do_rarp && (d->able & IC_RARP))
+			ic_rarp_send_if(d);
+#endif
+
+		jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
+		while (time_before(jiffies, jiff) && !ic_got_reply)
+			schedule_timeout_uninterruptible(1);
+#ifdef IPCONFIG_DHCP
+		/* DHCP isn't done until we get a DHCPACK. */
+		if ((ic_got_reply & IC_BOOTP)
+		    && (ic_proto_enabled & IC_USE_DHCP)
+		    && ic_dhcp_msgtype != DHCPACK)
+		{
+			ic_got_reply = 0;
+			printk(",");
+			continue;
+		}
+#endif /* IPCONFIG_DHCP */
+
+		if (ic_got_reply) {
+			printk(" OK\n");
+			break;
+		}
+
+		if ((d = d->next))
+			continue;
+
+		if (! --retries) {
+			printk(" timed out!\n");
+			break;
+		}
+
+		d = ic_first_dev;
+
+		timeout = timeout CONF_TIMEOUT_MULT;
+		if (timeout > CONF_TIMEOUT_MAX)
+			timeout = CONF_TIMEOUT_MAX;
+
+		printk(".");
+	}
+
+#ifdef IPCONFIG_BOOTP
+	if (do_bootp)
+		ic_bootp_cleanup();
+#endif
+#ifdef IPCONFIG_RARP
+	if (do_rarp)
+		ic_rarp_cleanup();
+#endif
+
+	if (!ic_got_reply) {
+		ic_myaddr = NONE;
+		return -1;
+	}
+
+	printk("IP-Config: Got %s answer from " NIPQUAD_FMT ", ",
+		((ic_got_reply & IC_RARP) ? "RARP"
+		 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
+		NIPQUAD(ic_servaddr));
+	printk("my address is " NIPQUAD_FMT "\n", NIPQUAD(ic_myaddr));
+
+	return 0;
+}
+
+#endif /* IPCONFIG_DYNAMIC */
+
+#ifdef CONFIG_PROC_FS
+
+static int pnp_seq_show(struct seq_file *seq, void *v)
+{
+	int i;
+
+	if (ic_proto_used & IC_PROTO)
+		seq_printf(seq, "#PROTO: %s\n",
+			   (ic_proto_used & IC_RARP) ? "RARP"
+			   : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
+	else
+		seq_puts(seq, "#MANUAL\n");
+
+	if (ic_domain[0])
+		seq_printf(seq,
+			   "domain %s\n", ic_domain);
+	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
+		if (ic_nameservers[i] != NONE)
+			seq_printf(seq,
+				   "nameserver " NIPQUAD_FMT "\n",
+				   NIPQUAD(ic_nameservers[i]));
+	}
+	if (ic_servaddr != NONE)
+		seq_printf(seq,
+			   "bootserver " NIPQUAD_FMT "\n",
+			   NIPQUAD(ic_servaddr));
+	return 0;
+}
+
+static int pnp_seq_open(struct inode *indoe, struct file *file)
+{
+	return single_open(file, pnp_seq_show, NULL);
+}
+
+static const struct file_operations pnp_seq_fops = {
+	.owner		= THIS_MODULE,
+	.open		= pnp_seq_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif /* CONFIG_PROC_FS */
+
+/*
+ *  Extract IP address from the parameter string if needed. Note that we
+ *  need to have root_server_addr set _before_ IPConfig gets called as it
+ *  can override it.
+ */
+__be32 __init root_nfs_parse_addr(char *name)
+{
+	__be32 addr;
+	int octets = 0;
+	char *cp, *cq;
+
+	cp = cq = name;
+	while (octets < 4) {
+		while (*cp >= '0' && *cp <= '9')
+			cp++;
+		if (cp == cq || cp - cq > 3)
+			break;
+		if (*cp == '.' || octets == 3)
+			octets++;
+		if (octets < 4)
+			cp++;
+		cq = cp;
+	}
+	if (octets == 4 && (*cp == ':' || *cp == '\0')) {
+		if (*cp == ':')
+			*cp++ = '\0';
+		addr = in_aton(name);
+		memmove(name, cp, strlen(cp) + 1);
+	} else
+		addr = NONE;
+
+	return addr;
+}
+
+/*
+ *	IP Autoconfig dispatcher.
+ */
+
+static int __init ip_auto_config(void)
+{
+	__be32 addr;
+#ifdef IPCONFIG_DYNAMIC
+	int retries = CONF_OPEN_RETRIES;
+#endif
+
+#ifdef CONFIG_PROC_FS
+	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
+#endif /* CONFIG_PROC_FS */
+
+	if (!ic_enable)
+		return 0;
+
+	DBG(("IP-Config: Entered.\n"));
+#ifdef IPCONFIG_DYNAMIC
+ try_try_again:
+#endif
+	/* Give hardware a chance to settle */
+	msleep(CONF_PRE_OPEN);
+
+	/* Setup all network devices */
+	if (ic_open_devs() < 0)
+		return -1;
+
+	/* Give drivers a chance to settle */
+	ssleep(CONF_POST_OPEN);
+
+	/*
+	 * If the config information is insufficient (e.g., our IP address or
+	 * IP address of the boot server is missing or we have multiple network
+	 * interfaces and no default was set), use BOOTP or RARP to get the
+	 * missing values.
+	 */
+	if (ic_myaddr == NONE ||
+#ifdef CONFIG_ROOT_NFS
+	    (root_server_addr == NONE
+	     && ic_servaddr == NONE
+	     && ROOT_DEV == Root_NFS) ||
+#endif
+	    ic_first_dev->next) {
+#ifdef IPCONFIG_DYNAMIC
+		if (ic_dynamic() < 0) {
+			ic_close_devs();
+
+			/*
+			 * I don't know why, but sometimes the
+			 * eepro100 driver (at least) gets upset and
+			 * doesn't work the first time it's opened.
+			 * But then if you close it and reopen it, it
+			 * works just fine.  So we need to try that at
+			 * least once before giving up.
+			 *
+			 * Also, if the root will be NFS-mounted, we
+			 * have nowhere to go if DHCP fails.  So we
+			 * just have to keep trying forever.
+			 *
+			 * 				-- Chip
+			 */
+#ifdef CONFIG_ROOT_NFS
+			if (ROOT_DEV ==  Root_NFS) {
+				printk(KERN_ERR
+					"IP-Config: Retrying forever (NFS root)...\n");
+				goto try_try_again;
+			}
+#endif
+
+			if (--retries) {
+				printk(KERN_ERR
+				       "IP-Config: Reopening network devices...\n");
+				goto try_try_again;
+			}
+
+			/* Oh, well.  At least we tried. */
+			printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
+			return -1;
+		}
+#else /* !DYNAMIC */
+		printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
+		ic_close_devs();
+		return -1;
+#endif /* IPCONFIG_DYNAMIC */
+	} else {
+		/* Device selected manually or only one device -> use it */
+		ic_dev = ic_first_dev->dev;
+	}
+
+	addr = root_nfs_parse_addr(root_server_path);
+	if (root_server_addr == NONE)
+		root_server_addr = addr;
+
+	/*
+	 * Use defaults whereever applicable.
+	 */
+	if (ic_defaults() < 0)
+		return -1;
+
+	/*
+	 * Close all network devices except the device we've
+	 * autoconfigured and set up routes.
+	 */
+	ic_close_devs();
+	if (ic_setup_if() < 0 || ic_setup_routes() < 0)
+		return -1;
+
+	/*
+	 * Record which protocol was actually used.
+	 */
+#ifdef IPCONFIG_DYNAMIC
+	ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
+#endif
+
+#ifndef IPCONFIG_SILENT
+	/*
+	 * Clue in the operator.
+	 */
+	printk("IP-Config: Complete:");
+	printk("\n     device=%s", ic_dev->name);
+	printk(", addr=" NIPQUAD_FMT, NIPQUAD(ic_myaddr));
+	printk(", mask=" NIPQUAD_FMT, NIPQUAD(ic_netmask));
+	printk(", gw=" NIPQUAD_FMT, NIPQUAD(ic_gateway));
+	printk(",\n     host=%s, domain=%s, nis-domain=%s",
+	       utsname()->nodename, ic_domain, utsname()->domainname);
+	printk(",\n     bootserver=" NIPQUAD_FMT, NIPQUAD(ic_servaddr));
+	printk(", rootserver=" NIPQUAD_FMT, NIPQUAD(root_server_addr));
+	printk(", rootpath=%s", root_server_path);
+	printk("\n");
+#endif /* !SILENT */
+
+	return 0;
+}
+
+late_initcall(ip_auto_config);
+
+
+/*
+ *  Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
+ *  command line parameter.  See Documentation/filesystems/nfsroot.txt.
+ */
+static int __init ic_proto_name(char *name)
+{
+	if (!strcmp(name, "on") || !strcmp(name, "any")) {
+		return 1;
+	}
+	if (!strcmp(name, "off") || !strcmp(name, "none")) {
+		return 0;
+	}
+#ifdef CONFIG_IP_PNP_DHCP
+	else if (!strcmp(name, "dhcp")) {
+		ic_proto_enabled &= ~IC_RARP;
+		return 1;
+	}
+#endif
+#ifdef CONFIG_IP_PNP_BOOTP
+	else if (!strcmp(name, "bootp")) {
+		ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
+		return 1;
+	}
+#endif
+#ifdef CONFIG_IP_PNP_RARP
+	else if (!strcmp(name, "rarp")) {
+		ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
+		return 1;
+	}
+#endif
+#ifdef IPCONFIG_DYNAMIC
+	else if (!strcmp(name, "both")) {
+		ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+static int __init ip_auto_config_setup(char *addrs)
+{
+	char *cp, *ip, *dp;
+	int num = 0;
+
+	ic_set_manually = 1;
+	ic_enable = 1;
+
+	/*
+	 * If any dhcp, bootp etc options are set, leave autoconfig on
+	 * and skip the below static IP processing.
+	 */
+	if (ic_proto_name(addrs))
+		return 1;
+
+	/* If no static IP is given, turn off autoconfig and bail.  */
+	if (*addrs == 0 ||
+	    strcmp(addrs, "off") == 0 ||
+	    strcmp(addrs, "none") == 0) {
+		ic_enable = 0;
+		return 1;
+	}
+
+	/* Parse string for static IP assignment.  */
+	ip = addrs;
+	while (ip && *ip) {
+		if ((cp = strchr(ip, ':')))
+			*cp++ = '\0';
+		if (strlen(ip) > 0) {
+			DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
+			switch (num) {
+			case 0:
+				if ((ic_myaddr = in_aton(ip)) == ANY)
+					ic_myaddr = NONE;
+				break;
+			case 1:
+				if ((ic_servaddr = in_aton(ip)) == ANY)
+					ic_servaddr = NONE;
+				break;
+			case 2:
+				if ((ic_gateway = in_aton(ip)) == ANY)
+					ic_gateway = NONE;
+				break;
+			case 3:
+				if ((ic_netmask = in_aton(ip)) == ANY)
+					ic_netmask = NONE;
+				break;
+			case 4:
+				if ((dp = strchr(ip, '.'))) {
+					*dp++ = '\0';
+					strlcpy(utsname()->domainname, dp,
+						sizeof(utsname()->domainname));
+				}
+				strlcpy(utsname()->nodename, ip,
+					sizeof(utsname()->nodename));
+				ic_host_name_set = 1;
+				break;
+			case 5:
+				strlcpy(user_dev_name, ip, sizeof(user_dev_name));
+				break;
+			case 6:
+				if (ic_proto_name(ip) == 0 &&
+				    ic_myaddr == NONE) {
+					ic_enable = 0;
+				}
+				break;
+			}
+		}
+		ip = cp;
+		num++;
+	}
+
+	return 1;
+}
+
+static int __init nfsaddrs_config_setup(char *addrs)
+{
+	return ip_auto_config_setup(addrs);
+}
+
+static int __init vendor_class_identifier_setup(char *addrs)
+{
+	if (strlcpy(vendor_class_identifier, addrs,
+		    sizeof(vendor_class_identifier))
+	    >= sizeof(vendor_class_identifier))
+		printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
+		       vendor_class_identifier);
+	return 1;
+}
+
+__setup("ip=", ip_auto_config_setup);
+__setup("nfsaddrs=", nfsaddrs_config_setup);
+__setup("dhcpclass=", vendor_class_identifier_setup);
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
new file mode 100644
index 0000000..29609d2
--- /dev/null
+++ b/net/ipv4/ipip.c
@@ -0,0 +1,859 @@
+/*
+ *	Linux NET3:	IP/IP protocol decoder.
+ *
+ *	Authors:
+ *		Sam Lantinga (slouken@cs.ucdavis.edu)  02/01/95
+ *
+ *	Fixes:
+ *		Alan Cox	:	Merged and made usable non modular (its so tiny its silly as
+ *					a module taking up 2 pages).
+ *		Alan Cox	: 	Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
+ *					to keep ip_forward happy.
+ *		Alan Cox	:	More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
+ *		Kai Schulte	:	Fixed #defines for IP_FIREWALL->FIREWALL
+ *              David Woodhouse :       Perform some basic ICMP handling.
+ *                                      IPIP Routing without decapsulation.
+ *              Carlos Picoto   :       GRE over IP support
+ *		Alexey Kuznetsov:	Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
+ *					I do not want to merge them together.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ */
+
+/* tunnel.c: an IP tunnel driver
+
+	The purpose of this driver is to provide an IP tunnel through
+	which you can tunnel network traffic transparently across subnets.
+
+	This was written by looking at Nick Holloway's dummy driver
+	Thanks for the great code!
+
+		-Sam Lantinga	(slouken@cs.ucdavis.edu)  02/01/95
+
+	Minor tweaks:
+		Cleaned up the code a little and added some pre-1.3.0 tweaks.
+		dev->hard_header/hard_header_len changed to use no headers.
+		Comments/bracketing tweaked.
+		Made the tunnels use dev->name not tunnel: when error reporting.
+		Added tx_dropped stat
+
+		-Alan Cox	(alan@lxorguk.ukuu.org.uk) 21 March 95
+
+	Reworked:
+		Changed to tunnel to destination gateway in addition to the
+			tunnel's pointopoint address
+		Almost completely rewritten
+		Note:  There is currently no firewall or ICMP handling done.
+
+		-Sam Lantinga	(slouken@cs.ucdavis.edu) 02/13/96
+
+*/
+
+/* Things I wish I had known when writing the tunnel driver:
+
+	When the tunnel_xmit() function is called, the skb contains the
+	packet to be sent (plus a great deal of extra info), and dev
+	contains the tunnel device that _we_ are.
+
+	When we are passed a packet, we are expected to fill in the
+	source address with our source IP address.
+
+	What is the proper way to allocate, copy and free a buffer?
+	After you allocate it, it is a "0 length" chunk of memory
+	starting at zero.  If you want to add headers to the buffer
+	later, you'll have to call "skb_reserve(skb, amount)" with
+	the amount of memory you want reserved.  Then, you call
+	"skb_put(skb, amount)" with the amount of space you want in
+	the buffer.  skb_put() returns a pointer to the top (#0) of
+	that buffer.  skb->len is set to the amount of space you have
+	"allocated" with skb_put().  You can then write up to skb->len
+	bytes to that buffer.  If you need more, you can call skb_put()
+	again with the additional amount of space you need.  You can
+	find out how much more space you can allocate by calling
+	"skb_tailroom(skb)".
+	Now, to add header space, call "skb_push(skb, header_len)".
+	This creates space at the beginning of the buffer and returns
+	a pointer to this new space.  If later you need to strip a
+	header from a buffer, call "skb_pull(skb, header_len)".
+	skb_headroom() will return how much space is left at the top
+	of the buffer (before the main data).  Remember, this headroom
+	space must be reserved before the skb_put() function is called.
+	*/
+
+/*
+   This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
+
+   For comments look at net/ipv4/ip_gre.c --ANK
+ */
+
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/if_ether.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/ipip.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+#define HASH_SIZE  16
+#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
+
+static int ipip_net_id;
+struct ipip_net {
+	struct ip_tunnel *tunnels_r_l[HASH_SIZE];
+	struct ip_tunnel *tunnels_r[HASH_SIZE];
+	struct ip_tunnel *tunnels_l[HASH_SIZE];
+	struct ip_tunnel *tunnels_wc[1];
+	struct ip_tunnel **tunnels[4];
+
+	struct net_device *fb_tunnel_dev;
+};
+
+static int ipip_fb_tunnel_init(struct net_device *dev);
+static int ipip_tunnel_init(struct net_device *dev);
+static void ipip_tunnel_setup(struct net_device *dev);
+
+static DEFINE_RWLOCK(ipip_lock);
+
+static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
+		__be32 remote, __be32 local)
+{
+	unsigned h0 = HASH(remote);
+	unsigned h1 = HASH(local);
+	struct ip_tunnel *t;
+	struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+	for (t = ipn->tunnels_r_l[h0^h1]; t; t = t->next) {
+		if (local == t->parms.iph.saddr &&
+		    remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
+			return t;
+	}
+	for (t = ipn->tunnels_r[h0]; t; t = t->next) {
+		if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
+			return t;
+	}
+	for (t = ipn->tunnels_l[h1]; t; t = t->next) {
+		if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
+			return t;
+	}
+	if ((t = ipn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
+		return t;
+	return NULL;
+}
+
+static struct ip_tunnel **__ipip_bucket(struct ipip_net *ipn,
+		struct ip_tunnel_parm *parms)
+{
+	__be32 remote = parms->iph.daddr;
+	__be32 local = parms->iph.saddr;
+	unsigned h = 0;
+	int prio = 0;
+
+	if (remote) {
+		prio |= 2;
+		h ^= HASH(remote);
+	}
+	if (local) {
+		prio |= 1;
+		h ^= HASH(local);
+	}
+	return &ipn->tunnels[prio][h];
+}
+
+static inline struct ip_tunnel **ipip_bucket(struct ipip_net *ipn,
+		struct ip_tunnel *t)
+{
+	return __ipip_bucket(ipn, &t->parms);
+}
+
+static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
+{
+	struct ip_tunnel **tp;
+
+	for (tp = ipip_bucket(ipn, t); *tp; tp = &(*tp)->next) {
+		if (t == *tp) {
+			write_lock_bh(&ipip_lock);
+			*tp = t->next;
+			write_unlock_bh(&ipip_lock);
+			break;
+		}
+	}
+}
+
+static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
+{
+	struct ip_tunnel **tp = ipip_bucket(ipn, t);
+
+	t->next = *tp;
+	write_lock_bh(&ipip_lock);
+	*tp = t;
+	write_unlock_bh(&ipip_lock);
+}
+
+static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
+		struct ip_tunnel_parm *parms, int create)
+{
+	__be32 remote = parms->iph.daddr;
+	__be32 local = parms->iph.saddr;
+	struct ip_tunnel *t, **tp, *nt;
+	struct net_device *dev;
+	char name[IFNAMSIZ];
+	struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+	for (tp = __ipip_bucket(ipn, parms); (t = *tp) != NULL; tp = &t->next) {
+		if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
+			return t;
+	}
+	if (!create)
+		return NULL;
+
+	if (parms->name[0])
+		strlcpy(name, parms->name, IFNAMSIZ);
+	else
+		sprintf(name, "tunl%%d");
+
+	dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
+	if (dev == NULL)
+		return NULL;
+
+	dev_net_set(dev, net);
+
+	if (strchr(name, '%')) {
+		if (dev_alloc_name(dev, name) < 0)
+			goto failed_free;
+	}
+
+	nt = netdev_priv(dev);
+	dev->init = ipip_tunnel_init;
+	nt->parms = *parms;
+
+	if (register_netdevice(dev) < 0)
+		goto failed_free;
+
+	dev_hold(dev);
+	ipip_tunnel_link(ipn, nt);
+	return nt;
+
+failed_free:
+	free_netdev(dev);
+	return NULL;
+}
+
+static void ipip_tunnel_uninit(struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+	struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+	if (dev == ipn->fb_tunnel_dev) {
+		write_lock_bh(&ipip_lock);
+		ipn->tunnels_wc[0] = NULL;
+		write_unlock_bh(&ipip_lock);
+	} else
+		ipip_tunnel_unlink(ipn, netdev_priv(dev));
+	dev_put(dev);
+}
+
+static int ipip_err(struct sk_buff *skb, u32 info)
+{
+
+/* All the routers (except for Linux) return only
+   8 bytes of packet payload. It means, that precise relaying of
+   ICMP in the real Internet is absolutely infeasible.
+ */
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	const int type = icmp_hdr(skb)->type;
+	const int code = icmp_hdr(skb)->code;
+	struct ip_tunnel *t;
+	int err;
+
+	switch (type) {
+	default:
+	case ICMP_PARAMETERPROB:
+		return 0;
+
+	case ICMP_DEST_UNREACH:
+		switch (code) {
+		case ICMP_SR_FAILED:
+		case ICMP_PORT_UNREACH:
+			/* Impossible event. */
+			return 0;
+		case ICMP_FRAG_NEEDED:
+			/* Soft state for pmtu is maintained by IP core. */
+			return 0;
+		default:
+			/* All others are translated to HOST_UNREACH.
+			   rfc2003 contains "deep thoughts" about NET_UNREACH,
+			   I believe they are just ether pollution. --ANK
+			 */
+			break;
+		}
+		break;
+	case ICMP_TIME_EXCEEDED:
+		if (code != ICMP_EXC_TTL)
+			return 0;
+		break;
+	}
+
+	err = -ENOENT;
+
+	read_lock(&ipip_lock);
+	t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
+	if (t == NULL || t->parms.iph.daddr == 0)
+		goto out;
+
+	err = 0;
+	if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+		goto out;
+
+	if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
+		t->err_count++;
+	else
+		t->err_count = 1;
+	t->err_time = jiffies;
+out:
+	read_unlock(&ipip_lock);
+	return err;
+}
+
+static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
+					struct sk_buff *skb)
+{
+	struct iphdr *inner_iph = ip_hdr(skb);
+
+	if (INET_ECN_is_ce(outer_iph->tos))
+		IP_ECN_set_ce(inner_iph);
+}
+
+static int ipip_rcv(struct sk_buff *skb)
+{
+	struct ip_tunnel *tunnel;
+	const struct iphdr *iph = ip_hdr(skb);
+
+	read_lock(&ipip_lock);
+	if ((tunnel = ipip_tunnel_lookup(dev_net(skb->dev),
+					iph->saddr, iph->daddr)) != NULL) {
+		if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+			read_unlock(&ipip_lock);
+			kfree_skb(skb);
+			return 0;
+		}
+
+		secpath_reset(skb);
+
+		skb->mac_header = skb->network_header;
+		skb_reset_network_header(skb);
+		skb->protocol = htons(ETH_P_IP);
+		skb->pkt_type = PACKET_HOST;
+
+		tunnel->dev->stats.rx_packets++;
+		tunnel->dev->stats.rx_bytes += skb->len;
+		skb->dev = tunnel->dev;
+		dst_release(skb->dst);
+		skb->dst = NULL;
+		nf_reset(skb);
+		ipip_ecn_decapsulate(iph, skb);
+		netif_rx(skb);
+		read_unlock(&ipip_lock);
+		return 0;
+	}
+	read_unlock(&ipip_lock);
+
+	return -1;
+}
+
+/*
+ *	This function assumes it is being called from dev_queue_xmit()
+ *	and that skb is filled properly by that function.
+ */
+
+static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct net_device_stats *stats = &tunnel->dev->stats;
+	struct iphdr  *tiph = &tunnel->parms.iph;
+	u8     tos = tunnel->parms.iph.tos;
+	__be16 df = tiph->frag_off;
+	struct rtable *rt;     			/* Route to the other host */
+	struct net_device *tdev;			/* Device to other host */
+	struct iphdr  *old_iph = ip_hdr(skb);
+	struct iphdr  *iph;			/* Our new IP header */
+	unsigned int max_headroom;		/* The extra header space needed */
+	__be32 dst = tiph->daddr;
+	int    mtu;
+
+	if (tunnel->recursion++) {
+		stats->collisions++;
+		goto tx_error;
+	}
+
+	if (skb->protocol != htons(ETH_P_IP))
+		goto tx_error;
+
+	if (tos&1)
+		tos = old_iph->tos;
+
+	if (!dst) {
+		/* NBMA tunnel */
+		if ((rt = skb->rtable) == NULL) {
+			stats->tx_fifo_errors++;
+			goto tx_error;
+		}
+		if ((dst = rt->rt_gateway) == 0)
+			goto tx_error_icmp;
+	}
+
+	{
+		struct flowi fl = { .oif = tunnel->parms.link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = dst,
+						.saddr = tiph->saddr,
+						.tos = RT_TOS(tos) } },
+				    .proto = IPPROTO_IPIP };
+		if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
+			stats->tx_carrier_errors++;
+			goto tx_error_icmp;
+		}
+	}
+	tdev = rt->u.dst.dev;
+
+	if (tdev == dev) {
+		ip_rt_put(rt);
+		stats->collisions++;
+		goto tx_error;
+	}
+
+	if (tiph->frag_off)
+		mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
+	else
+		mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
+
+	if (mtu < 68) {
+		stats->collisions++;
+		ip_rt_put(rt);
+		goto tx_error;
+	}
+	if (skb->dst)
+		skb->dst->ops->update_pmtu(skb->dst, mtu);
+
+	df |= (old_iph->frag_off&htons(IP_DF));
+
+	if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) {
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+		ip_rt_put(rt);
+		goto tx_error;
+	}
+
+	if (tunnel->err_count > 0) {
+		if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
+			tunnel->err_count--;
+			dst_link_failure(skb);
+		} else
+			tunnel->err_count = 0;
+	}
+
+	/*
+	 * Okay, now see if we can stuff it in the buffer as-is.
+	 */
+	max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
+
+	if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
+	    (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
+		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
+		if (!new_skb) {
+			ip_rt_put(rt);
+			stats->tx_dropped++;
+			dev_kfree_skb(skb);
+			tunnel->recursion--;
+			return 0;
+		}
+		if (skb->sk)
+			skb_set_owner_w(new_skb, skb->sk);
+		dev_kfree_skb(skb);
+		skb = new_skb;
+		old_iph = ip_hdr(skb);
+	}
+
+	skb->transport_header = skb->network_header;
+	skb_push(skb, sizeof(struct iphdr));
+	skb_reset_network_header(skb);
+	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
+			      IPSKB_REROUTED);
+	dst_release(skb->dst);
+	skb->dst = &rt->u.dst;
+
+	/*
+	 *	Push down and install the IPIP header.
+	 */
+
+	iph 			=	ip_hdr(skb);
+	iph->version		=	4;
+	iph->ihl		=	sizeof(struct iphdr)>>2;
+	iph->frag_off		=	df;
+	iph->protocol		=	IPPROTO_IPIP;
+	iph->tos		=	INET_ECN_encapsulate(tos, old_iph->tos);
+	iph->daddr		=	rt->rt_dst;
+	iph->saddr		=	rt->rt_src;
+
+	if ((iph->ttl = tiph->ttl) == 0)
+		iph->ttl	=	old_iph->ttl;
+
+	nf_reset(skb);
+
+	IPTUNNEL_XMIT();
+	tunnel->recursion--;
+	return 0;
+
+tx_error_icmp:
+	dst_link_failure(skb);
+tx_error:
+	stats->tx_errors++;
+	dev_kfree_skb(skb);
+	tunnel->recursion--;
+	return 0;
+}
+
+static void ipip_tunnel_bind_dev(struct net_device *dev)
+{
+	struct net_device *tdev = NULL;
+	struct ip_tunnel *tunnel;
+	struct iphdr *iph;
+
+	tunnel = netdev_priv(dev);
+	iph = &tunnel->parms.iph;
+
+	if (iph->daddr) {
+		struct flowi fl = { .oif = tunnel->parms.link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = iph->daddr,
+						.saddr = iph->saddr,
+						.tos = RT_TOS(iph->tos) } },
+				    .proto = IPPROTO_IPIP };
+		struct rtable *rt;
+		if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
+			tdev = rt->u.dst.dev;
+			ip_rt_put(rt);
+		}
+		dev->flags |= IFF_POINTOPOINT;
+	}
+
+	if (!tdev && tunnel->parms.link)
+		tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
+
+	if (tdev) {
+		dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
+		dev->mtu = tdev->mtu - sizeof(struct iphdr);
+	}
+	dev->iflink = tunnel->parms.link;
+}
+
+static int
+ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+	int err = 0;
+	struct ip_tunnel_parm p;
+	struct ip_tunnel *t;
+	struct net *net = dev_net(dev);
+	struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+	switch (cmd) {
+	case SIOCGETTUNNEL:
+		t = NULL;
+		if (dev == ipn->fb_tunnel_dev) {
+			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
+				err = -EFAULT;
+				break;
+			}
+			t = ipip_tunnel_locate(net, &p, 0);
+		}
+		if (t == NULL)
+			t = netdev_priv(dev);
+		memcpy(&p, &t->parms, sizeof(p));
+		if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+			err = -EFAULT;
+		break;
+
+	case SIOCADDTUNNEL:
+	case SIOCCHGTUNNEL:
+		err = -EPERM;
+		if (!capable(CAP_NET_ADMIN))
+			goto done;
+
+		err = -EFAULT;
+		if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+			goto done;
+
+		err = -EINVAL;
+		if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
+		    p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
+			goto done;
+		if (p.iph.ttl)
+			p.iph.frag_off |= htons(IP_DF);
+
+		t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
+
+		if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+			if (t != NULL) {
+				if (t->dev != dev) {
+					err = -EEXIST;
+					break;
+				}
+			} else {
+				if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
+				    (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
+					err = -EINVAL;
+					break;
+				}
+				t = netdev_priv(dev);
+				ipip_tunnel_unlink(ipn, t);
+				t->parms.iph.saddr = p.iph.saddr;
+				t->parms.iph.daddr = p.iph.daddr;
+				memcpy(dev->dev_addr, &p.iph.saddr, 4);
+				memcpy(dev->broadcast, &p.iph.daddr, 4);
+				ipip_tunnel_link(ipn, t);
+				netdev_state_change(dev);
+			}
+		}
+
+		if (t) {
+			err = 0;
+			if (cmd == SIOCCHGTUNNEL) {
+				t->parms.iph.ttl = p.iph.ttl;
+				t->parms.iph.tos = p.iph.tos;
+				t->parms.iph.frag_off = p.iph.frag_off;
+				if (t->parms.link != p.link) {
+					t->parms.link = p.link;
+					ipip_tunnel_bind_dev(dev);
+					netdev_state_change(dev);
+				}
+			}
+			if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+				err = -EFAULT;
+		} else
+			err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+		break;
+
+	case SIOCDELTUNNEL:
+		err = -EPERM;
+		if (!capable(CAP_NET_ADMIN))
+			goto done;
+
+		if (dev == ipn->fb_tunnel_dev) {
+			err = -EFAULT;
+			if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+				goto done;
+			err = -ENOENT;
+			if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
+				goto done;
+			err = -EPERM;
+			if (t->dev == ipn->fb_tunnel_dev)
+				goto done;
+			dev = t->dev;
+		}
+		unregister_netdevice(dev);
+		err = 0;
+		break;
+
+	default:
+		err = -EINVAL;
+	}
+
+done:
+	return err;
+}
+
+static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+	if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
+		return -EINVAL;
+	dev->mtu = new_mtu;
+	return 0;
+}
+
+static void ipip_tunnel_setup(struct net_device *dev)
+{
+	dev->uninit		= ipip_tunnel_uninit;
+	dev->hard_start_xmit	= ipip_tunnel_xmit;
+	dev->do_ioctl		= ipip_tunnel_ioctl;
+	dev->change_mtu		= ipip_tunnel_change_mtu;
+	dev->destructor		= free_netdev;
+
+	dev->type		= ARPHRD_TUNNEL;
+	dev->hard_header_len 	= LL_MAX_HEADER + sizeof(struct iphdr);
+	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr);
+	dev->flags		= IFF_NOARP;
+	dev->iflink		= 0;
+	dev->addr_len		= 4;
+	dev->features		|= NETIF_F_NETNS_LOCAL;
+}
+
+static int ipip_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel;
+
+	tunnel = netdev_priv(dev);
+
+	tunnel->dev = dev;
+	strcpy(tunnel->parms.name, dev->name);
+
+	memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
+	memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
+
+	ipip_tunnel_bind_dev(dev);
+
+	return 0;
+}
+
+static int ipip_fb_tunnel_init(struct net_device *dev)
+{
+	struct ip_tunnel *tunnel = netdev_priv(dev);
+	struct iphdr *iph = &tunnel->parms.iph;
+	struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
+
+	tunnel->dev = dev;
+	strcpy(tunnel->parms.name, dev->name);
+
+	iph->version		= 4;
+	iph->protocol		= IPPROTO_IPIP;
+	iph->ihl		= 5;
+
+	dev_hold(dev);
+	ipn->tunnels_wc[0]	= tunnel;
+	return 0;
+}
+
+static struct xfrm_tunnel ipip_handler = {
+	.handler	=	ipip_rcv,
+	.err_handler	=	ipip_err,
+	.priority	=	1,
+};
+
+static char banner[] __initdata =
+	KERN_INFO "IPv4 over IPv4 tunneling driver\n";
+
+static void ipip_destroy_tunnels(struct ipip_net *ipn)
+{
+	int prio;
+
+	for (prio = 1; prio < 4; prio++) {
+		int h;
+		for (h = 0; h < HASH_SIZE; h++) {
+			struct ip_tunnel *t;
+			while ((t = ipn->tunnels[prio][h]) != NULL)
+				unregister_netdevice(t->dev);
+		}
+	}
+}
+
+static int ipip_init_net(struct net *net)
+{
+	int err;
+	struct ipip_net *ipn;
+
+	err = -ENOMEM;
+	ipn = kzalloc(sizeof(struct ipip_net), GFP_KERNEL);
+	if (ipn == NULL)
+		goto err_alloc;
+
+	err = net_assign_generic(net, ipip_net_id, ipn);
+	if (err < 0)
+		goto err_assign;
+
+	ipn->tunnels[0] = ipn->tunnels_wc;
+	ipn->tunnels[1] = ipn->tunnels_l;
+	ipn->tunnels[2] = ipn->tunnels_r;
+	ipn->tunnels[3] = ipn->tunnels_r_l;
+
+	ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
+					   "tunl0",
+					   ipip_tunnel_setup);
+	if (!ipn->fb_tunnel_dev) {
+		err = -ENOMEM;
+		goto err_alloc_dev;
+	}
+
+	ipn->fb_tunnel_dev->init = ipip_fb_tunnel_init;
+	dev_net_set(ipn->fb_tunnel_dev, net);
+
+	if ((err = register_netdev(ipn->fb_tunnel_dev)))
+		goto err_reg_dev;
+
+	return 0;
+
+err_reg_dev:
+	free_netdev(ipn->fb_tunnel_dev);
+err_alloc_dev:
+	/* nothing */
+err_assign:
+	kfree(ipn);
+err_alloc:
+	return err;
+}
+
+static void ipip_exit_net(struct net *net)
+{
+	struct ipip_net *ipn;
+
+	ipn = net_generic(net, ipip_net_id);
+	rtnl_lock();
+	ipip_destroy_tunnels(ipn);
+	unregister_netdevice(ipn->fb_tunnel_dev);
+	rtnl_unlock();
+	kfree(ipn);
+}
+
+static struct pernet_operations ipip_net_ops = {
+	.init = ipip_init_net,
+	.exit = ipip_exit_net,
+};
+
+static int __init ipip_init(void)
+{
+	int err;
+
+	printk(banner);
+
+	if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) {
+		printk(KERN_INFO "ipip init: can't register tunnel\n");
+		return -EAGAIN;
+	}
+
+	err = register_pernet_gen_device(&ipip_net_id, &ipip_net_ops);
+	if (err)
+		xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
+
+	return err;
+}
+
+static void __exit ipip_fini(void)
+{
+	if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
+		printk(KERN_INFO "ipip close: can't deregister tunnel\n");
+
+	unregister_pernet_gen_device(ipip_net_id, &ipip_net_ops);
+}
+
+module_init(ipip_init);
+module_exit(ipip_fini);
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
new file mode 100644
index 0000000..25924b1
--- /dev/null
+++ b/net/ipv4/ipmr.c
@@ -0,0 +1,1958 @@
+/*
+ *	IP multicast routing support for mrouted 3.6/3.8
+ *
+ *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
+ *	  Linux Consultancy and Custom Driver Development
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	Fixes:
+ *	Michael Chastain	:	Incorrect size of copying.
+ *	Alan Cox		:	Added the cache manager code
+ *	Alan Cox		:	Fixed the clone/copy bug and device race.
+ *	Mike McLagan		:	Routing by source
+ *	Malcolm Beattie		:	Buffer handling fixes.
+ *	Alexey Kuznetsov	:	Double buffer free and other fixes.
+ *	SVR Anand		:	Fixed several multicast bugs and problems.
+ *	Alexey Kuznetsov	:	Status, optimisations and more.
+ *	Brad Parker		:	Better behaviour on mrouted upcall
+ *					overflow.
+ *      Carlos Picoto           :       PIMv1 Support
+ *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
+ *					Relax this requrement to work with older peers.
+ *
+ */
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <linux/types.h>
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/fcntl.h>
+#include <linux/stat.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <linux/if_ether.h>
+#include <net/net_namespace.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <net/sock.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/raw.h>
+#include <linux/notifier.h>
+#include <linux/if_arp.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/ipip.h>
+#include <net/checksum.h>
+#include <net/netlink.h>
+
+#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
+#define CONFIG_IP_PIMSM	1
+#endif
+
+static struct sock *mroute_socket;
+
+
+/* Big lock, protecting vif table, mrt cache and mroute socket state.
+   Note that the changes are semaphored via rtnl_lock.
+ */
+
+static DEFINE_RWLOCK(mrt_lock);
+
+/*
+ *	Multicast router control variables
+ */
+
+static struct vif_device vif_table[MAXVIFS];		/* Devices 		*/
+static int maxvif;
+
+#define VIF_EXISTS(idx) (vif_table[idx].dev != NULL)
+
+static int mroute_do_assert;				/* Set in PIM assert	*/
+static int mroute_do_pim;
+
+static struct mfc_cache *mfc_cache_array[MFC_LINES];	/* Forwarding cache	*/
+
+static struct mfc_cache *mfc_unres_queue;		/* Queue of unresolved entries */
+static atomic_t cache_resolve_queue_len;		/* Size of unresolved	*/
+
+/* Special spinlock for queue of unresolved entries */
+static DEFINE_SPINLOCK(mfc_unres_lock);
+
+/* We return to original Alan's scheme. Hash table of resolved
+   entries is changed only in process context and protected
+   with weak lock mrt_lock. Queue of unresolved entries is protected
+   with strong spinlock mfc_unres_lock.
+
+   In this case data path is free of exclusive locks at all.
+ */
+
+static struct kmem_cache *mrt_cachep __read_mostly;
+
+static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local);
+static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert);
+static int ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm);
+
+#ifdef CONFIG_IP_PIMSM_V2
+static struct net_protocol pim_protocol;
+#endif
+
+static struct timer_list ipmr_expire_timer;
+
+/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
+
+static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
+{
+	dev_close(dev);
+
+	dev = __dev_get_by_name(&init_net, "tunl0");
+	if (dev) {
+		struct ifreq ifr;
+		mm_segment_t	oldfs;
+		struct ip_tunnel_parm p;
+
+		memset(&p, 0, sizeof(p));
+		p.iph.daddr = v->vifc_rmt_addr.s_addr;
+		p.iph.saddr = v->vifc_lcl_addr.s_addr;
+		p.iph.version = 4;
+		p.iph.ihl = 5;
+		p.iph.protocol = IPPROTO_IPIP;
+		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
+		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
+
+		oldfs = get_fs(); set_fs(KERNEL_DS);
+		dev->do_ioctl(dev, &ifr, SIOCDELTUNNEL);
+		set_fs(oldfs);
+	}
+}
+
+static
+struct net_device *ipmr_new_tunnel(struct vifctl *v)
+{
+	struct net_device  *dev;
+
+	dev = __dev_get_by_name(&init_net, "tunl0");
+
+	if (dev) {
+		int err;
+		struct ifreq ifr;
+		mm_segment_t	oldfs;
+		struct ip_tunnel_parm p;
+		struct in_device  *in_dev;
+
+		memset(&p, 0, sizeof(p));
+		p.iph.daddr = v->vifc_rmt_addr.s_addr;
+		p.iph.saddr = v->vifc_lcl_addr.s_addr;
+		p.iph.version = 4;
+		p.iph.ihl = 5;
+		p.iph.protocol = IPPROTO_IPIP;
+		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
+		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
+
+		oldfs = get_fs(); set_fs(KERNEL_DS);
+		err = dev->do_ioctl(dev, &ifr, SIOCADDTUNNEL);
+		set_fs(oldfs);
+
+		dev = NULL;
+
+		if (err == 0 && (dev = __dev_get_by_name(&init_net, p.name)) != NULL) {
+			dev->flags |= IFF_MULTICAST;
+
+			in_dev = __in_dev_get_rtnl(dev);
+			if (in_dev == NULL)
+				goto failure;
+
+			ipv4_devconf_setall(in_dev);
+			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
+
+			if (dev_open(dev))
+				goto failure;
+			dev_hold(dev);
+		}
+	}
+	return dev;
+
+failure:
+	/* allow the register to be completed before unregistering. */
+	rtnl_unlock();
+	rtnl_lock();
+
+	unregister_netdevice(dev);
+	return NULL;
+}
+
+#ifdef CONFIG_IP_PIMSM
+
+static int reg_vif_num = -1;
+
+static int reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	read_lock(&mrt_lock);
+	dev->stats.tx_bytes += skb->len;
+	dev->stats.tx_packets++;
+	ipmr_cache_report(skb, reg_vif_num, IGMPMSG_WHOLEPKT);
+	read_unlock(&mrt_lock);
+	kfree_skb(skb);
+	return 0;
+}
+
+static void reg_vif_setup(struct net_device *dev)
+{
+	dev->type		= ARPHRD_PIMREG;
+	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
+	dev->flags		= IFF_NOARP;
+	dev->hard_start_xmit	= reg_vif_xmit;
+	dev->destructor		= free_netdev;
+}
+
+static struct net_device *ipmr_reg_vif(void)
+{
+	struct net_device *dev;
+	struct in_device *in_dev;
+
+	dev = alloc_netdev(0, "pimreg", reg_vif_setup);
+
+	if (dev == NULL)
+		return NULL;
+
+	if (register_netdevice(dev)) {
+		free_netdev(dev);
+		return NULL;
+	}
+	dev->iflink = 0;
+
+	rcu_read_lock();
+	if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
+		rcu_read_unlock();
+		goto failure;
+	}
+
+	ipv4_devconf_setall(in_dev);
+	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
+	rcu_read_unlock();
+
+	if (dev_open(dev))
+		goto failure;
+
+	dev_hold(dev);
+
+	return dev;
+
+failure:
+	/* allow the register to be completed before unregistering. */
+	rtnl_unlock();
+	rtnl_lock();
+
+	unregister_netdevice(dev);
+	return NULL;
+}
+#endif
+
+/*
+ *	Delete a VIF entry
+ *	@notify: Set to 1, if the caller is a notifier_call
+ */
+
+static int vif_delete(int vifi, int notify)
+{
+	struct vif_device *v;
+	struct net_device *dev;
+	struct in_device *in_dev;
+
+	if (vifi < 0 || vifi >= maxvif)
+		return -EADDRNOTAVAIL;
+
+	v = &vif_table[vifi];
+
+	write_lock_bh(&mrt_lock);
+	dev = v->dev;
+	v->dev = NULL;
+
+	if (!dev) {
+		write_unlock_bh(&mrt_lock);
+		return -EADDRNOTAVAIL;
+	}
+
+#ifdef CONFIG_IP_PIMSM
+	if (vifi == reg_vif_num)
+		reg_vif_num = -1;
+#endif
+
+	if (vifi+1 == maxvif) {
+		int tmp;
+		for (tmp=vifi-1; tmp>=0; tmp--) {
+			if (VIF_EXISTS(tmp))
+				break;
+		}
+		maxvif = tmp+1;
+	}
+
+	write_unlock_bh(&mrt_lock);
+
+	dev_set_allmulti(dev, -1);
+
+	if ((in_dev = __in_dev_get_rtnl(dev)) != NULL) {
+		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
+		ip_rt_multicast_event(in_dev);
+	}
+
+	if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER) && !notify)
+		unregister_netdevice(dev);
+
+	dev_put(dev);
+	return 0;
+}
+
+/* Destroy an unresolved cache entry, killing queued skbs
+   and reporting error to netlink readers.
+ */
+
+static void ipmr_destroy_unres(struct mfc_cache *c)
+{
+	struct sk_buff *skb;
+	struct nlmsgerr *e;
+
+	atomic_dec(&cache_resolve_queue_len);
+
+	while ((skb=skb_dequeue(&c->mfc_un.unres.unresolved))) {
+		if (ip_hdr(skb)->version == 0) {
+			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
+			nlh->nlmsg_type = NLMSG_ERROR;
+			nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
+			skb_trim(skb, nlh->nlmsg_len);
+			e = NLMSG_DATA(nlh);
+			e->error = -ETIMEDOUT;
+			memset(&e->msg, 0, sizeof(e->msg));
+
+			rtnl_unicast(skb, &init_net, NETLINK_CB(skb).pid);
+		} else
+			kfree_skb(skb);
+	}
+
+	kmem_cache_free(mrt_cachep, c);
+}
+
+
+/* Single timer process for all the unresolved queue. */
+
+static void ipmr_expire_process(unsigned long dummy)
+{
+	unsigned long now;
+	unsigned long expires;
+	struct mfc_cache *c, **cp;
+
+	if (!spin_trylock(&mfc_unres_lock)) {
+		mod_timer(&ipmr_expire_timer, jiffies+HZ/10);
+		return;
+	}
+
+	if (atomic_read(&cache_resolve_queue_len) == 0)
+		goto out;
+
+	now = jiffies;
+	expires = 10*HZ;
+	cp = &mfc_unres_queue;
+
+	while ((c=*cp) != NULL) {
+		if (time_after(c->mfc_un.unres.expires, now)) {
+			unsigned long interval = c->mfc_un.unres.expires - now;
+			if (interval < expires)
+				expires = interval;
+			cp = &c->next;
+			continue;
+		}
+
+		*cp = c->next;
+
+		ipmr_destroy_unres(c);
+	}
+
+	if (atomic_read(&cache_resolve_queue_len))
+		mod_timer(&ipmr_expire_timer, jiffies + expires);
+
+out:
+	spin_unlock(&mfc_unres_lock);
+}
+
+/* Fill oifs list. It is called under write locked mrt_lock. */
+
+static void ipmr_update_thresholds(struct mfc_cache *cache, unsigned char *ttls)
+{
+	int vifi;
+
+	cache->mfc_un.res.minvif = MAXVIFS;
+	cache->mfc_un.res.maxvif = 0;
+	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
+
+	for (vifi=0; vifi<maxvif; vifi++) {
+		if (VIF_EXISTS(vifi) && ttls[vifi] && ttls[vifi] < 255) {
+			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
+			if (cache->mfc_un.res.minvif > vifi)
+				cache->mfc_un.res.minvif = vifi;
+			if (cache->mfc_un.res.maxvif <= vifi)
+				cache->mfc_un.res.maxvif = vifi + 1;
+		}
+	}
+}
+
+static int vif_add(struct vifctl *vifc, int mrtsock)
+{
+	int vifi = vifc->vifc_vifi;
+	struct vif_device *v = &vif_table[vifi];
+	struct net_device *dev;
+	struct in_device *in_dev;
+	int err;
+
+	/* Is vif busy ? */
+	if (VIF_EXISTS(vifi))
+		return -EADDRINUSE;
+
+	switch (vifc->vifc_flags) {
+#ifdef CONFIG_IP_PIMSM
+	case VIFF_REGISTER:
+		/*
+		 * Special Purpose VIF in PIM
+		 * All the packets will be sent to the daemon
+		 */
+		if (reg_vif_num >= 0)
+			return -EADDRINUSE;
+		dev = ipmr_reg_vif();
+		if (!dev)
+			return -ENOBUFS;
+		err = dev_set_allmulti(dev, 1);
+		if (err) {
+			unregister_netdevice(dev);
+			dev_put(dev);
+			return err;
+		}
+		break;
+#endif
+	case VIFF_TUNNEL:
+		dev = ipmr_new_tunnel(vifc);
+		if (!dev)
+			return -ENOBUFS;
+		err = dev_set_allmulti(dev, 1);
+		if (err) {
+			ipmr_del_tunnel(dev, vifc);
+			dev_put(dev);
+			return err;
+		}
+		break;
+	case 0:
+		dev = ip_dev_find(&init_net, vifc->vifc_lcl_addr.s_addr);
+		if (!dev)
+			return -EADDRNOTAVAIL;
+		err = dev_set_allmulti(dev, 1);
+		if (err) {
+			dev_put(dev);
+			return err;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if ((in_dev = __in_dev_get_rtnl(dev)) == NULL)
+		return -EADDRNOTAVAIL;
+	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
+	ip_rt_multicast_event(in_dev);
+
+	/*
+	 *	Fill in the VIF structures
+	 */
+	v->rate_limit=vifc->vifc_rate_limit;
+	v->local=vifc->vifc_lcl_addr.s_addr;
+	v->remote=vifc->vifc_rmt_addr.s_addr;
+	v->flags=vifc->vifc_flags;
+	if (!mrtsock)
+		v->flags |= VIFF_STATIC;
+	v->threshold=vifc->vifc_threshold;
+	v->bytes_in = 0;
+	v->bytes_out = 0;
+	v->pkt_in = 0;
+	v->pkt_out = 0;
+	v->link = dev->ifindex;
+	if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER))
+		v->link = dev->iflink;
+
+	/* And finish update writing critical data */
+	write_lock_bh(&mrt_lock);
+	v->dev=dev;
+#ifdef CONFIG_IP_PIMSM
+	if (v->flags&VIFF_REGISTER)
+		reg_vif_num = vifi;
+#endif
+	if (vifi+1 > maxvif)
+		maxvif = vifi+1;
+	write_unlock_bh(&mrt_lock);
+	return 0;
+}
+
+static struct mfc_cache *ipmr_cache_find(__be32 origin, __be32 mcastgrp)
+{
+	int line=MFC_HASH(mcastgrp,origin);
+	struct mfc_cache *c;
+
+	for (c=mfc_cache_array[line]; c; c = c->next) {
+		if (c->mfc_origin==origin && c->mfc_mcastgrp==mcastgrp)
+			break;
+	}
+	return c;
+}
+
+/*
+ *	Allocate a multicast cache entry
+ */
+static struct mfc_cache *ipmr_cache_alloc(void)
+{
+	struct mfc_cache *c=kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
+	if (c==NULL)
+		return NULL;
+	c->mfc_un.res.minvif = MAXVIFS;
+	return c;
+}
+
+static struct mfc_cache *ipmr_cache_alloc_unres(void)
+{
+	struct mfc_cache *c=kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
+	if (c==NULL)
+		return NULL;
+	skb_queue_head_init(&c->mfc_un.unres.unresolved);
+	c->mfc_un.unres.expires = jiffies + 10*HZ;
+	return c;
+}
+
+/*
+ *	A cache entry has gone into a resolved state from queued
+ */
+
+static void ipmr_cache_resolve(struct mfc_cache *uc, struct mfc_cache *c)
+{
+	struct sk_buff *skb;
+	struct nlmsgerr *e;
+
+	/*
+	 *	Play the pending entries through our router
+	 */
+
+	while ((skb=__skb_dequeue(&uc->mfc_un.unres.unresolved))) {
+		if (ip_hdr(skb)->version == 0) {
+			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
+
+			if (ipmr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) {
+				nlh->nlmsg_len = (skb_tail_pointer(skb) -
+						  (u8 *)nlh);
+			} else {
+				nlh->nlmsg_type = NLMSG_ERROR;
+				nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
+				skb_trim(skb, nlh->nlmsg_len);
+				e = NLMSG_DATA(nlh);
+				e->error = -EMSGSIZE;
+				memset(&e->msg, 0, sizeof(e->msg));
+			}
+
+			rtnl_unicast(skb, &init_net, NETLINK_CB(skb).pid);
+		} else
+			ip_mr_forward(skb, c, 0);
+	}
+}
+
+/*
+ *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
+ *	expects the following bizarre scheme.
+ *
+ *	Called under mrt_lock.
+ */
+
+static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
+{
+	struct sk_buff *skb;
+	const int ihl = ip_hdrlen(pkt);
+	struct igmphdr *igmp;
+	struct igmpmsg *msg;
+	int ret;
+
+#ifdef CONFIG_IP_PIMSM
+	if (assert == IGMPMSG_WHOLEPKT)
+		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
+	else
+#endif
+		skb = alloc_skb(128, GFP_ATOMIC);
+
+	if (!skb)
+		return -ENOBUFS;
+
+#ifdef CONFIG_IP_PIMSM
+	if (assert == IGMPMSG_WHOLEPKT) {
+		/* Ugly, but we have no choice with this interface.
+		   Duplicate old header, fix ihl, length etc.
+		   And all this only to mangle msg->im_msgtype and
+		   to set msg->im_mbz to "mbz" :-)
+		 */
+		skb_push(skb, sizeof(struct iphdr));
+		skb_reset_network_header(skb);
+		skb_reset_transport_header(skb);
+		msg = (struct igmpmsg *)skb_network_header(skb);
+		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
+		msg->im_msgtype = IGMPMSG_WHOLEPKT;
+		msg->im_mbz = 0;
+		msg->im_vif = reg_vif_num;
+		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
+		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
+					     sizeof(struct iphdr));
+	} else
+#endif
+	{
+
+	/*
+	 *	Copy the IP header
+	 */
+
+	skb->network_header = skb->tail;
+	skb_put(skb, ihl);
+	skb_copy_to_linear_data(skb, pkt->data, ihl);
+	ip_hdr(skb)->protocol = 0;			/* Flag to the kernel this is a route add */
+	msg = (struct igmpmsg *)skb_network_header(skb);
+	msg->im_vif = vifi;
+	skb->dst = dst_clone(pkt->dst);
+
+	/*
+	 *	Add our header
+	 */
+
+	igmp=(struct igmphdr *)skb_put(skb,sizeof(struct igmphdr));
+	igmp->type	=
+	msg->im_msgtype = assert;
+	igmp->code 	=	0;
+	ip_hdr(skb)->tot_len = htons(skb->len);			/* Fix the length */
+	skb->transport_header = skb->network_header;
+	}
+
+	if (mroute_socket == NULL) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	/*
+	 *	Deliver to mrouted
+	 */
+	if ((ret=sock_queue_rcv_skb(mroute_socket,skb))<0) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
+		kfree_skb(skb);
+	}
+
+	return ret;
+}
+
+/*
+ *	Queue a packet for resolution. It gets locked cache entry!
+ */
+
+static int
+ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
+{
+	int err;
+	struct mfc_cache *c;
+	const struct iphdr *iph = ip_hdr(skb);
+
+	spin_lock_bh(&mfc_unres_lock);
+	for (c=mfc_unres_queue; c; c=c->next) {
+		if (c->mfc_mcastgrp == iph->daddr &&
+		    c->mfc_origin == iph->saddr)
+			break;
+	}
+
+	if (c == NULL) {
+		/*
+		 *	Create a new entry if allowable
+		 */
+
+		if (atomic_read(&cache_resolve_queue_len)>=10 ||
+		    (c=ipmr_cache_alloc_unres())==NULL) {
+			spin_unlock_bh(&mfc_unres_lock);
+
+			kfree_skb(skb);
+			return -ENOBUFS;
+		}
+
+		/*
+		 *	Fill in the new cache entry
+		 */
+		c->mfc_parent	= -1;
+		c->mfc_origin	= iph->saddr;
+		c->mfc_mcastgrp	= iph->daddr;
+
+		/*
+		 *	Reflect first query at mrouted.
+		 */
+		if ((err = ipmr_cache_report(skb, vifi, IGMPMSG_NOCACHE))<0) {
+			/* If the report failed throw the cache entry
+			   out - Brad Parker
+			 */
+			spin_unlock_bh(&mfc_unres_lock);
+
+			kmem_cache_free(mrt_cachep, c);
+			kfree_skb(skb);
+			return err;
+		}
+
+		atomic_inc(&cache_resolve_queue_len);
+		c->next = mfc_unres_queue;
+		mfc_unres_queue = c;
+
+		mod_timer(&ipmr_expire_timer, c->mfc_un.unres.expires);
+	}
+
+	/*
+	 *	See if we can append the packet
+	 */
+	if (c->mfc_un.unres.unresolved.qlen>3) {
+		kfree_skb(skb);
+		err = -ENOBUFS;
+	} else {
+		skb_queue_tail(&c->mfc_un.unres.unresolved,skb);
+		err = 0;
+	}
+
+	spin_unlock_bh(&mfc_unres_lock);
+	return err;
+}
+
+/*
+ *	MFC cache manipulation by user space mroute daemon
+ */
+
+static int ipmr_mfc_delete(struct mfcctl *mfc)
+{
+	int line;
+	struct mfc_cache *c, **cp;
+
+	line=MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
+
+	for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
+		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
+		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
+			write_lock_bh(&mrt_lock);
+			*cp = c->next;
+			write_unlock_bh(&mrt_lock);
+
+			kmem_cache_free(mrt_cachep, c);
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
+{
+	int line;
+	struct mfc_cache *uc, *c, **cp;
+
+	line=MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
+
+	for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
+		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
+		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr)
+			break;
+	}
+
+	if (c != NULL) {
+		write_lock_bh(&mrt_lock);
+		c->mfc_parent = mfc->mfcc_parent;
+		ipmr_update_thresholds(c, mfc->mfcc_ttls);
+		if (!mrtsock)
+			c->mfc_flags |= MFC_STATIC;
+		write_unlock_bh(&mrt_lock);
+		return 0;
+	}
+
+	if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
+		return -EINVAL;
+
+	c=ipmr_cache_alloc();
+	if (c==NULL)
+		return -ENOMEM;
+
+	c->mfc_origin=mfc->mfcc_origin.s_addr;
+	c->mfc_mcastgrp=mfc->mfcc_mcastgrp.s_addr;
+	c->mfc_parent=mfc->mfcc_parent;
+	ipmr_update_thresholds(c, mfc->mfcc_ttls);
+	if (!mrtsock)
+		c->mfc_flags |= MFC_STATIC;
+
+	write_lock_bh(&mrt_lock);
+	c->next = mfc_cache_array[line];
+	mfc_cache_array[line] = c;
+	write_unlock_bh(&mrt_lock);
+
+	/*
+	 *	Check to see if we resolved a queued list. If so we
+	 *	need to send on the frames and tidy up.
+	 */
+	spin_lock_bh(&mfc_unres_lock);
+	for (cp = &mfc_unres_queue; (uc=*cp) != NULL;
+	     cp = &uc->next) {
+		if (uc->mfc_origin == c->mfc_origin &&
+		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
+			*cp = uc->next;
+			if (atomic_dec_and_test(&cache_resolve_queue_len))
+				del_timer(&ipmr_expire_timer);
+			break;
+		}
+	}
+	spin_unlock_bh(&mfc_unres_lock);
+
+	if (uc) {
+		ipmr_cache_resolve(uc, c);
+		kmem_cache_free(mrt_cachep, uc);
+	}
+	return 0;
+}
+
+/*
+ *	Close the multicast socket, and clear the vif tables etc
+ */
+
+static void mroute_clean_tables(struct sock *sk)
+{
+	int i;
+
+	/*
+	 *	Shut down all active vif entries
+	 */
+	for (i=0; i<maxvif; i++) {
+		if (!(vif_table[i].flags&VIFF_STATIC))
+			vif_delete(i, 0);
+	}
+
+	/*
+	 *	Wipe the cache
+	 */
+	for (i=0;i<MFC_LINES;i++) {
+		struct mfc_cache *c, **cp;
+
+		cp = &mfc_cache_array[i];
+		while ((c = *cp) != NULL) {
+			if (c->mfc_flags&MFC_STATIC) {
+				cp = &c->next;
+				continue;
+			}
+			write_lock_bh(&mrt_lock);
+			*cp = c->next;
+			write_unlock_bh(&mrt_lock);
+
+			kmem_cache_free(mrt_cachep, c);
+		}
+	}
+
+	if (atomic_read(&cache_resolve_queue_len) != 0) {
+		struct mfc_cache *c;
+
+		spin_lock_bh(&mfc_unres_lock);
+		while (mfc_unres_queue != NULL) {
+			c = mfc_unres_queue;
+			mfc_unres_queue = c->next;
+			spin_unlock_bh(&mfc_unres_lock);
+
+			ipmr_destroy_unres(c);
+
+			spin_lock_bh(&mfc_unres_lock);
+		}
+		spin_unlock_bh(&mfc_unres_lock);
+	}
+}
+
+static void mrtsock_destruct(struct sock *sk)
+{
+	rtnl_lock();
+	if (sk == mroute_socket) {
+		IPV4_DEVCONF_ALL(sock_net(sk), MC_FORWARDING)--;
+
+		write_lock_bh(&mrt_lock);
+		mroute_socket=NULL;
+		write_unlock_bh(&mrt_lock);
+
+		mroute_clean_tables(sk);
+	}
+	rtnl_unlock();
+}
+
+/*
+ *	Socket options and virtual interface manipulation. The whole
+ *	virtual interface system is a complete heap, but unfortunately
+ *	that's how BSD mrouted happens to think. Maybe one day with a proper
+ *	MOSPF/PIM router set up we can clean this up.
+ */
+
+int ip_mroute_setsockopt(struct sock *sk,int optname,char __user *optval,int optlen)
+{
+	int ret;
+	struct vifctl vif;
+	struct mfcctl mfc;
+
+	if (optname != MRT_INIT) {
+		if (sk != mroute_socket && !capable(CAP_NET_ADMIN))
+			return -EACCES;
+	}
+
+	switch (optname) {
+	case MRT_INIT:
+		if (sk->sk_type != SOCK_RAW ||
+		    inet_sk(sk)->num != IPPROTO_IGMP)
+			return -EOPNOTSUPP;
+		if (optlen!=sizeof(int))
+			return -ENOPROTOOPT;
+
+		rtnl_lock();
+		if (mroute_socket) {
+			rtnl_unlock();
+			return -EADDRINUSE;
+		}
+
+		ret = ip_ra_control(sk, 1, mrtsock_destruct);
+		if (ret == 0) {
+			write_lock_bh(&mrt_lock);
+			mroute_socket=sk;
+			write_unlock_bh(&mrt_lock);
+
+			IPV4_DEVCONF_ALL(sock_net(sk), MC_FORWARDING)++;
+		}
+		rtnl_unlock();
+		return ret;
+	case MRT_DONE:
+		if (sk!=mroute_socket)
+			return -EACCES;
+		return ip_ra_control(sk, 0, NULL);
+	case MRT_ADD_VIF:
+	case MRT_DEL_VIF:
+		if (optlen!=sizeof(vif))
+			return -EINVAL;
+		if (copy_from_user(&vif,optval,sizeof(vif)))
+			return -EFAULT;
+		if (vif.vifc_vifi >= MAXVIFS)
+			return -ENFILE;
+		rtnl_lock();
+		if (optname==MRT_ADD_VIF) {
+			ret = vif_add(&vif, sk==mroute_socket);
+		} else {
+			ret = vif_delete(vif.vifc_vifi, 0);
+		}
+		rtnl_unlock();
+		return ret;
+
+		/*
+		 *	Manipulate the forwarding caches. These live
+		 *	in a sort of kernel/user symbiosis.
+		 */
+	case MRT_ADD_MFC:
+	case MRT_DEL_MFC:
+		if (optlen!=sizeof(mfc))
+			return -EINVAL;
+		if (copy_from_user(&mfc,optval, sizeof(mfc)))
+			return -EFAULT;
+		rtnl_lock();
+		if (optname==MRT_DEL_MFC)
+			ret = ipmr_mfc_delete(&mfc);
+		else
+			ret = ipmr_mfc_add(&mfc, sk==mroute_socket);
+		rtnl_unlock();
+		return ret;
+		/*
+		 *	Control PIM assert.
+		 */
+	case MRT_ASSERT:
+	{
+		int v;
+		if (get_user(v,(int __user *)optval))
+			return -EFAULT;
+		mroute_do_assert=(v)?1:0;
+		return 0;
+	}
+#ifdef CONFIG_IP_PIMSM
+	case MRT_PIM:
+	{
+		int v;
+
+		if (get_user(v,(int __user *)optval))
+			return -EFAULT;
+		v = (v) ? 1 : 0;
+
+		rtnl_lock();
+		ret = 0;
+		if (v != mroute_do_pim) {
+			mroute_do_pim = v;
+			mroute_do_assert = v;
+#ifdef CONFIG_IP_PIMSM_V2
+			if (mroute_do_pim)
+				ret = inet_add_protocol(&pim_protocol,
+							IPPROTO_PIM);
+			else
+				ret = inet_del_protocol(&pim_protocol,
+							IPPROTO_PIM);
+			if (ret < 0)
+				ret = -EAGAIN;
+#endif
+		}
+		rtnl_unlock();
+		return ret;
+	}
+#endif
+	/*
+	 *	Spurious command, or MRT_VERSION which you cannot
+	 *	set.
+	 */
+	default:
+		return -ENOPROTOOPT;
+	}
+}
+
+/*
+ *	Getsock opt support for the multicast routing system.
+ */
+
+int ip_mroute_getsockopt(struct sock *sk,int optname,char __user *optval,int __user *optlen)
+{
+	int olr;
+	int val;
+
+	if (optname!=MRT_VERSION &&
+#ifdef CONFIG_IP_PIMSM
+	   optname!=MRT_PIM &&
+#endif
+	   optname!=MRT_ASSERT)
+		return -ENOPROTOOPT;
+
+	if (get_user(olr, optlen))
+		return -EFAULT;
+
+	olr = min_t(unsigned int, olr, sizeof(int));
+	if (olr < 0)
+		return -EINVAL;
+
+	if (put_user(olr,optlen))
+		return -EFAULT;
+	if (optname==MRT_VERSION)
+		val=0x0305;
+#ifdef CONFIG_IP_PIMSM
+	else if (optname==MRT_PIM)
+		val=mroute_do_pim;
+#endif
+	else
+		val=mroute_do_assert;
+	if (copy_to_user(optval,&val,olr))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ *	The IP multicast ioctl support routines.
+ */
+
+int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
+{
+	struct sioc_sg_req sr;
+	struct sioc_vif_req vr;
+	struct vif_device *vif;
+	struct mfc_cache *c;
+
+	switch (cmd) {
+	case SIOCGETVIFCNT:
+		if (copy_from_user(&vr,arg,sizeof(vr)))
+			return -EFAULT;
+		if (vr.vifi>=maxvif)
+			return -EINVAL;
+		read_lock(&mrt_lock);
+		vif=&vif_table[vr.vifi];
+		if (VIF_EXISTS(vr.vifi))	{
+			vr.icount=vif->pkt_in;
+			vr.ocount=vif->pkt_out;
+			vr.ibytes=vif->bytes_in;
+			vr.obytes=vif->bytes_out;
+			read_unlock(&mrt_lock);
+
+			if (copy_to_user(arg,&vr,sizeof(vr)))
+				return -EFAULT;
+			return 0;
+		}
+		read_unlock(&mrt_lock);
+		return -EADDRNOTAVAIL;
+	case SIOCGETSGCNT:
+		if (copy_from_user(&sr,arg,sizeof(sr)))
+			return -EFAULT;
+
+		read_lock(&mrt_lock);
+		c = ipmr_cache_find(sr.src.s_addr, sr.grp.s_addr);
+		if (c) {
+			sr.pktcnt = c->mfc_un.res.pkt;
+			sr.bytecnt = c->mfc_un.res.bytes;
+			sr.wrong_if = c->mfc_un.res.wrong_if;
+			read_unlock(&mrt_lock);
+
+			if (copy_to_user(arg,&sr,sizeof(sr)))
+				return -EFAULT;
+			return 0;
+		}
+		read_unlock(&mrt_lock);
+		return -EADDRNOTAVAIL;
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
+
+static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+	struct vif_device *v;
+	int ct;
+
+	if (!net_eq(dev_net(dev), &init_net))
+		return NOTIFY_DONE;
+
+	if (event != NETDEV_UNREGISTER)
+		return NOTIFY_DONE;
+	v=&vif_table[0];
+	for (ct=0;ct<maxvif;ct++,v++) {
+		if (v->dev==dev)
+			vif_delete(ct, 1);
+	}
+	return NOTIFY_DONE;
+}
+
+
+static struct notifier_block ip_mr_notifier={
+	.notifier_call = ipmr_device_event,
+};
+
+/*
+ * 	Encapsulate a packet by attaching a valid IPIP header to it.
+ *	This avoids tunnel drivers and other mess and gives us the speed so
+ *	important for multicast video.
+ */
+
+static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
+{
+	struct iphdr *iph;
+	struct iphdr *old_iph = ip_hdr(skb);
+
+	skb_push(skb, sizeof(struct iphdr));
+	skb->transport_header = skb->network_header;
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+
+	iph->version	= 	4;
+	iph->tos	=	old_iph->tos;
+	iph->ttl	=	old_iph->ttl;
+	iph->frag_off	=	0;
+	iph->daddr	=	daddr;
+	iph->saddr	=	saddr;
+	iph->protocol	=	IPPROTO_IPIP;
+	iph->ihl	=	5;
+	iph->tot_len	=	htons(skb->len);
+	ip_select_ident(iph, skb->dst, NULL);
+	ip_send_check(iph);
+
+	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+	nf_reset(skb);
+}
+
+static inline int ipmr_forward_finish(struct sk_buff *skb)
+{
+	struct ip_options * opt	= &(IPCB(skb)->opt);
+
+	IP_INC_STATS_BH(dev_net(skb->dst->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
+
+	if (unlikely(opt->optlen))
+		ip_forward_options(skb);
+
+	return dst_output(skb);
+}
+
+/*
+ *	Processing handlers for ipmr_forward
+ */
+
+static void ipmr_queue_xmit(struct sk_buff *skb, struct mfc_cache *c, int vifi)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	struct vif_device *vif = &vif_table[vifi];
+	struct net_device *dev;
+	struct rtable *rt;
+	int    encap = 0;
+
+	if (vif->dev == NULL)
+		goto out_free;
+
+#ifdef CONFIG_IP_PIMSM
+	if (vif->flags & VIFF_REGISTER) {
+		vif->pkt_out++;
+		vif->bytes_out+=skb->len;
+		vif->dev->stats.tx_bytes += skb->len;
+		vif->dev->stats.tx_packets++;
+		ipmr_cache_report(skb, vifi, IGMPMSG_WHOLEPKT);
+		kfree_skb(skb);
+		return;
+	}
+#endif
+
+	if (vif->flags&VIFF_TUNNEL) {
+		struct flowi fl = { .oif = vif->link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = vif->remote,
+						.saddr = vif->local,
+						.tos = RT_TOS(iph->tos) } },
+				    .proto = IPPROTO_IPIP };
+		if (ip_route_output_key(&init_net, &rt, &fl))
+			goto out_free;
+		encap = sizeof(struct iphdr);
+	} else {
+		struct flowi fl = { .oif = vif->link,
+				    .nl_u = { .ip4_u =
+					      { .daddr = iph->daddr,
+						.tos = RT_TOS(iph->tos) } },
+				    .proto = IPPROTO_IPIP };
+		if (ip_route_output_key(&init_net, &rt, &fl))
+			goto out_free;
+	}
+
+	dev = rt->u.dst.dev;
+
+	if (skb->len+encap > dst_mtu(&rt->u.dst) && (ntohs(iph->frag_off) & IP_DF)) {
+		/* Do not fragment multicasts. Alas, IPv4 does not
+		   allow to send ICMP, so that packets will disappear
+		   to blackhole.
+		 */
+
+		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
+		ip_rt_put(rt);
+		goto out_free;
+	}
+
+	encap += LL_RESERVED_SPACE(dev) + rt->u.dst.header_len;
+
+	if (skb_cow(skb, encap)) {
+		ip_rt_put(rt);
+		goto out_free;
+	}
+
+	vif->pkt_out++;
+	vif->bytes_out+=skb->len;
+
+	dst_release(skb->dst);
+	skb->dst = &rt->u.dst;
+	ip_decrease_ttl(ip_hdr(skb));
+
+	/* FIXME: forward and output firewalls used to be called here.
+	 * What do we do with netfilter? -- RR */
+	if (vif->flags & VIFF_TUNNEL) {
+		ip_encap(skb, vif->local, vif->remote);
+		/* FIXME: extra output firewall step used to be here. --RR */
+		vif->dev->stats.tx_packets++;
+		vif->dev->stats.tx_bytes += skb->len;
+	}
+
+	IPCB(skb)->flags |= IPSKB_FORWARDED;
+
+	/*
+	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
+	 * not only before forwarding, but after forwarding on all output
+	 * interfaces. It is clear, if mrouter runs a multicasting
+	 * program, it should receive packets not depending to what interface
+	 * program is joined.
+	 * If we will not make it, the program will have to join on all
+	 * interfaces. On the other hand, multihoming host (or router, but
+	 * not mrouter) cannot join to more than one interface - it will
+	 * result in receiving multiple packets.
+	 */
+	NF_HOOK(PF_INET, NF_INET_FORWARD, skb, skb->dev, dev,
+		ipmr_forward_finish);
+	return;
+
+out_free:
+	kfree_skb(skb);
+	return;
+}
+
+static int ipmr_find_vif(struct net_device *dev)
+{
+	int ct;
+	for (ct=maxvif-1; ct>=0; ct--) {
+		if (vif_table[ct].dev == dev)
+			break;
+	}
+	return ct;
+}
+
+/* "local" means that we should preserve one skb (for local delivery) */
+
+static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local)
+{
+	int psend = -1;
+	int vif, ct;
+
+	vif = cache->mfc_parent;
+	cache->mfc_un.res.pkt++;
+	cache->mfc_un.res.bytes += skb->len;
+
+	/*
+	 * Wrong interface: drop packet and (maybe) send PIM assert.
+	 */
+	if (vif_table[vif].dev != skb->dev) {
+		int true_vifi;
+
+		if (skb->rtable->fl.iif == 0) {
+			/* It is our own packet, looped back.
+			   Very complicated situation...
+
+			   The best workaround until routing daemons will be
+			   fixed is not to redistribute packet, if it was
+			   send through wrong interface. It means, that
+			   multicast applications WILL NOT work for
+			   (S,G), which have default multicast route pointing
+			   to wrong oif. In any case, it is not a good
+			   idea to use multicasting applications on router.
+			 */
+			goto dont_forward;
+		}
+
+		cache->mfc_un.res.wrong_if++;
+		true_vifi = ipmr_find_vif(skb->dev);
+
+		if (true_vifi >= 0 && mroute_do_assert &&
+		    /* pimsm uses asserts, when switching from RPT to SPT,
+		       so that we cannot check that packet arrived on an oif.
+		       It is bad, but otherwise we would need to move pretty
+		       large chunk of pimd to kernel. Ough... --ANK
+		     */
+		    (mroute_do_pim || cache->mfc_un.res.ttls[true_vifi] < 255) &&
+		    time_after(jiffies,
+			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
+			cache->mfc_un.res.last_assert = jiffies;
+			ipmr_cache_report(skb, true_vifi, IGMPMSG_WRONGVIF);
+		}
+		goto dont_forward;
+	}
+
+	vif_table[vif].pkt_in++;
+	vif_table[vif].bytes_in+=skb->len;
+
+	/*
+	 *	Forward the frame
+	 */
+	for (ct = cache->mfc_un.res.maxvif-1; ct >= cache->mfc_un.res.minvif; ct--) {
+		if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
+			if (psend != -1) {
+				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (skb2)
+					ipmr_queue_xmit(skb2, cache, psend);
+			}
+			psend=ct;
+		}
+	}
+	if (psend != -1) {
+		if (local) {
+			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+			if (skb2)
+				ipmr_queue_xmit(skb2, cache, psend);
+		} else {
+			ipmr_queue_xmit(skb, cache, psend);
+			return 0;
+		}
+	}
+
+dont_forward:
+	if (!local)
+		kfree_skb(skb);
+	return 0;
+}
+
+
+/*
+ *	Multicast packets for forwarding arrive here
+ */
+
+int ip_mr_input(struct sk_buff *skb)
+{
+	struct mfc_cache *cache;
+	int local = skb->rtable->rt_flags&RTCF_LOCAL;
+
+	/* Packet is looped back after forward, it should not be
+	   forwarded second time, but still can be delivered locally.
+	 */
+	if (IPCB(skb)->flags&IPSKB_FORWARDED)
+		goto dont_forward;
+
+	if (!local) {
+		    if (IPCB(skb)->opt.router_alert) {
+			    if (ip_call_ra_chain(skb))
+				    return 0;
+		    } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP){
+			    /* IGMPv1 (and broken IGMPv2 implementations sort of
+			       Cisco IOS <= 11.2(8)) do not put router alert
+			       option to IGMP packets destined to routable
+			       groups. It is very bad, because it means
+			       that we can forward NO IGMP messages.
+			     */
+			    read_lock(&mrt_lock);
+			    if (mroute_socket) {
+				    nf_reset(skb);
+				    raw_rcv(mroute_socket, skb);
+				    read_unlock(&mrt_lock);
+				    return 0;
+			    }
+			    read_unlock(&mrt_lock);
+		    }
+	}
+
+	read_lock(&mrt_lock);
+	cache = ipmr_cache_find(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
+
+	/*
+	 *	No usable cache entry
+	 */
+	if (cache==NULL) {
+		int vif;
+
+		if (local) {
+			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+			ip_local_deliver(skb);
+			if (skb2 == NULL) {
+				read_unlock(&mrt_lock);
+				return -ENOBUFS;
+			}
+			skb = skb2;
+		}
+
+		vif = ipmr_find_vif(skb->dev);
+		if (vif >= 0) {
+			int err = ipmr_cache_unresolved(vif, skb);
+			read_unlock(&mrt_lock);
+
+			return err;
+		}
+		read_unlock(&mrt_lock);
+		kfree_skb(skb);
+		return -ENODEV;
+	}
+
+	ip_mr_forward(skb, cache, local);
+
+	read_unlock(&mrt_lock);
+
+	if (local)
+		return ip_local_deliver(skb);
+
+	return 0;
+
+dont_forward:
+	if (local)
+		return ip_local_deliver(skb);
+	kfree_skb(skb);
+	return 0;
+}
+
+#ifdef CONFIG_IP_PIMSM_V1
+/*
+ * Handle IGMP messages of PIMv1
+ */
+
+int pim_rcv_v1(struct sk_buff * skb)
+{
+	struct igmphdr *pim;
+	struct iphdr   *encap;
+	struct net_device  *reg_dev = NULL;
+
+	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
+		goto drop;
+
+	pim = igmp_hdr(skb);
+
+	if (!mroute_do_pim ||
+	    skb->len < sizeof(*pim) + sizeof(*encap) ||
+	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
+		goto drop;
+
+	encap = (struct iphdr *)(skb_transport_header(skb) +
+				 sizeof(struct igmphdr));
+	/*
+	   Check that:
+	   a. packet is really destinted to a multicast group
+	   b. packet is not a NULL-REGISTER
+	   c. packet is not truncated
+	 */
+	if (!ipv4_is_multicast(encap->daddr) ||
+	    encap->tot_len == 0 ||
+	    ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
+		goto drop;
+
+	read_lock(&mrt_lock);
+	if (reg_vif_num >= 0)
+		reg_dev = vif_table[reg_vif_num].dev;
+	if (reg_dev)
+		dev_hold(reg_dev);
+	read_unlock(&mrt_lock);
+
+	if (reg_dev == NULL)
+		goto drop;
+
+	skb->mac_header = skb->network_header;
+	skb_pull(skb, (u8*)encap - skb->data);
+	skb_reset_network_header(skb);
+	skb->dev = reg_dev;
+	skb->protocol = htons(ETH_P_IP);
+	skb->ip_summed = 0;
+	skb->pkt_type = PACKET_HOST;
+	dst_release(skb->dst);
+	skb->dst = NULL;
+	reg_dev->stats.rx_bytes += skb->len;
+	reg_dev->stats.rx_packets++;
+	nf_reset(skb);
+	netif_rx(skb);
+	dev_put(reg_dev);
+	return 0;
+ drop:
+	kfree_skb(skb);
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_IP_PIMSM_V2
+static int pim_rcv(struct sk_buff * skb)
+{
+	struct pimreghdr *pim;
+	struct iphdr   *encap;
+	struct net_device  *reg_dev = NULL;
+
+	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
+		goto drop;
+
+	pim = (struct pimreghdr *)skb_transport_header(skb);
+	if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) ||
+	    (pim->flags&PIM_NULL_REGISTER) ||
+	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
+	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
+		goto drop;
+
+	/* check if the inner packet is destined to mcast group */
+	encap = (struct iphdr *)(skb_transport_header(skb) +
+				 sizeof(struct pimreghdr));
+	if (!ipv4_is_multicast(encap->daddr) ||
+	    encap->tot_len == 0 ||
+	    ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
+		goto drop;
+
+	read_lock(&mrt_lock);
+	if (reg_vif_num >= 0)
+		reg_dev = vif_table[reg_vif_num].dev;
+	if (reg_dev)
+		dev_hold(reg_dev);
+	read_unlock(&mrt_lock);
+
+	if (reg_dev == NULL)
+		goto drop;
+
+	skb->mac_header = skb->network_header;
+	skb_pull(skb, (u8*)encap - skb->data);
+	skb_reset_network_header(skb);
+	skb->dev = reg_dev;
+	skb->protocol = htons(ETH_P_IP);
+	skb->ip_summed = 0;
+	skb->pkt_type = PACKET_HOST;
+	dst_release(skb->dst);
+	reg_dev->stats.rx_bytes += skb->len;
+	reg_dev->stats.rx_packets++;
+	skb->dst = NULL;
+	nf_reset(skb);
+	netif_rx(skb);
+	dev_put(reg_dev);
+	return 0;
+ drop:
+	kfree_skb(skb);
+	return 0;
+}
+#endif
+
+static int
+ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm)
+{
+	int ct;
+	struct rtnexthop *nhp;
+	struct net_device *dev = vif_table[c->mfc_parent].dev;
+	u8 *b = skb_tail_pointer(skb);
+	struct rtattr *mp_head;
+
+	if (dev)
+		RTA_PUT(skb, RTA_IIF, 4, &dev->ifindex);
+
+	mp_head = (struct rtattr*)skb_put(skb, RTA_LENGTH(0));
+
+	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
+		if (c->mfc_un.res.ttls[ct] < 255) {
+			if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
+				goto rtattr_failure;
+			nhp = (struct rtnexthop*)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
+			nhp->rtnh_flags = 0;
+			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
+			nhp->rtnh_ifindex = vif_table[ct].dev->ifindex;
+			nhp->rtnh_len = sizeof(*nhp);
+		}
+	}
+	mp_head->rta_type = RTA_MULTIPATH;
+	mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
+	rtm->rtm_type = RTN_MULTICAST;
+	return 1;
+
+rtattr_failure:
+	nlmsg_trim(skb, b);
+	return -EMSGSIZE;
+}
+
+int ipmr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait)
+{
+	int err;
+	struct mfc_cache *cache;
+	struct rtable *rt = skb->rtable;
+
+	read_lock(&mrt_lock);
+	cache = ipmr_cache_find(rt->rt_src, rt->rt_dst);
+
+	if (cache==NULL) {
+		struct sk_buff *skb2;
+		struct iphdr *iph;
+		struct net_device *dev;
+		int vif;
+
+		if (nowait) {
+			read_unlock(&mrt_lock);
+			return -EAGAIN;
+		}
+
+		dev = skb->dev;
+		if (dev == NULL || (vif = ipmr_find_vif(dev)) < 0) {
+			read_unlock(&mrt_lock);
+			return -ENODEV;
+		}
+		skb2 = skb_clone(skb, GFP_ATOMIC);
+		if (!skb2) {
+			read_unlock(&mrt_lock);
+			return -ENOMEM;
+		}
+
+		skb_push(skb2, sizeof(struct iphdr));
+		skb_reset_network_header(skb2);
+		iph = ip_hdr(skb2);
+		iph->ihl = sizeof(struct iphdr) >> 2;
+		iph->saddr = rt->rt_src;
+		iph->daddr = rt->rt_dst;
+		iph->version = 0;
+		err = ipmr_cache_unresolved(vif, skb2);
+		read_unlock(&mrt_lock);
+		return err;
+	}
+
+	if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))
+		cache->mfc_flags |= MFC_NOTIFY;
+	err = ipmr_fill_mroute(skb, cache, rtm);
+	read_unlock(&mrt_lock);
+	return err;
+}
+
+#ifdef CONFIG_PROC_FS
+/*
+ *	The /proc interfaces to multicast routing /proc/ip_mr_cache /proc/ip_mr_vif
+ */
+struct ipmr_vif_iter {
+	int ct;
+};
+
+static struct vif_device *ipmr_vif_seq_idx(struct ipmr_vif_iter *iter,
+					   loff_t pos)
+{
+	for (iter->ct = 0; iter->ct < maxvif; ++iter->ct) {
+		if (!VIF_EXISTS(iter->ct))
+			continue;
+		if (pos-- == 0)
+			return &vif_table[iter->ct];
+	}
+	return NULL;
+}
+
+static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(mrt_lock)
+{
+	read_lock(&mrt_lock);
+	return *pos ? ipmr_vif_seq_idx(seq->private, *pos - 1)
+		: SEQ_START_TOKEN;
+}
+
+static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct ipmr_vif_iter *iter = seq->private;
+
+	++*pos;
+	if (v == SEQ_START_TOKEN)
+		return ipmr_vif_seq_idx(iter, 0);
+
+	while (++iter->ct < maxvif) {
+		if (!VIF_EXISTS(iter->ct))
+			continue;
+		return &vif_table[iter->ct];
+	}
+	return NULL;
+}
+
+static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
+	__releases(mrt_lock)
+{
+	read_unlock(&mrt_lock);
+}
+
+static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq,
+			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
+	} else {
+		const struct vif_device *vif = v;
+		const char *name =  vif->dev ? vif->dev->name : "none";
+
+		seq_printf(seq,
+			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
+			   vif - vif_table,
+			   name, vif->bytes_in, vif->pkt_in,
+			   vif->bytes_out, vif->pkt_out,
+			   vif->flags, vif->local, vif->remote);
+	}
+	return 0;
+}
+
+static const struct seq_operations ipmr_vif_seq_ops = {
+	.start = ipmr_vif_seq_start,
+	.next  = ipmr_vif_seq_next,
+	.stop  = ipmr_vif_seq_stop,
+	.show  = ipmr_vif_seq_show,
+};
+
+static int ipmr_vif_open(struct inode *inode, struct file *file)
+{
+	return seq_open_private(file, &ipmr_vif_seq_ops,
+			sizeof(struct ipmr_vif_iter));
+}
+
+static const struct file_operations ipmr_vif_fops = {
+	.owner	 = THIS_MODULE,
+	.open    = ipmr_vif_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release_private,
+};
+
+struct ipmr_mfc_iter {
+	struct mfc_cache **cache;
+	int ct;
+};
+
+
+static struct mfc_cache *ipmr_mfc_seq_idx(struct ipmr_mfc_iter *it, loff_t pos)
+{
+	struct mfc_cache *mfc;
+
+	it->cache = mfc_cache_array;
+	read_lock(&mrt_lock);
+	for (it->ct = 0; it->ct < MFC_LINES; it->ct++)
+		for (mfc = mfc_cache_array[it->ct]; mfc; mfc = mfc->next)
+			if (pos-- == 0)
+				return mfc;
+	read_unlock(&mrt_lock);
+
+	it->cache = &mfc_unres_queue;
+	spin_lock_bh(&mfc_unres_lock);
+	for (mfc = mfc_unres_queue; mfc; mfc = mfc->next)
+		if (pos-- == 0)
+			return mfc;
+	spin_unlock_bh(&mfc_unres_lock);
+
+	it->cache = NULL;
+	return NULL;
+}
+
+
+static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct ipmr_mfc_iter *it = seq->private;
+	it->cache = NULL;
+	it->ct = 0;
+	return *pos ? ipmr_mfc_seq_idx(seq->private, *pos - 1)
+		: SEQ_START_TOKEN;
+}
+
+static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct mfc_cache *mfc = v;
+	struct ipmr_mfc_iter *it = seq->private;
+
+	++*pos;
+
+	if (v == SEQ_START_TOKEN)
+		return ipmr_mfc_seq_idx(seq->private, 0);
+
+	if (mfc->next)
+		return mfc->next;
+
+	if (it->cache == &mfc_unres_queue)
+		goto end_of_list;
+
+	BUG_ON(it->cache != mfc_cache_array);
+
+	while (++it->ct < MFC_LINES) {
+		mfc = mfc_cache_array[it->ct];
+		if (mfc)
+			return mfc;
+	}
+
+	/* exhausted cache_array, show unresolved */
+	read_unlock(&mrt_lock);
+	it->cache = &mfc_unres_queue;
+	it->ct = 0;
+
+	spin_lock_bh(&mfc_unres_lock);
+	mfc = mfc_unres_queue;
+	if (mfc)
+		return mfc;
+
+ end_of_list:
+	spin_unlock_bh(&mfc_unres_lock);
+	it->cache = NULL;
+
+	return NULL;
+}
+
+static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
+{
+	struct ipmr_mfc_iter *it = seq->private;
+
+	if (it->cache == &mfc_unres_queue)
+		spin_unlock_bh(&mfc_unres_lock);
+	else if (it->cache == mfc_cache_array)
+		read_unlock(&mrt_lock);
+}
+
+static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
+{
+	int n;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq,
+		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
+	} else {
+		const struct mfc_cache *mfc = v;
+		const struct ipmr_mfc_iter *it = seq->private;
+
+		seq_printf(seq, "%08lX %08lX %-3d %8ld %8ld %8ld",
+			   (unsigned long) mfc->mfc_mcastgrp,
+			   (unsigned long) mfc->mfc_origin,
+			   mfc->mfc_parent,
+			   mfc->mfc_un.res.pkt,
+			   mfc->mfc_un.res.bytes,
+			   mfc->mfc_un.res.wrong_if);
+
+		if (it->cache != &mfc_unres_queue) {
+			for (n = mfc->mfc_un.res.minvif;
+			     n < mfc->mfc_un.res.maxvif; n++ ) {
+				if (VIF_EXISTS(n)
+				   && mfc->mfc_un.res.ttls[n] < 255)
+				seq_printf(seq,
+					   " %2d:%-3d",
+					   n, mfc->mfc_un.res.ttls[n]);
+			}
+		}
+		seq_putc(seq, '\n');
+	}
+	return 0;
+}
+
+static const struct seq_operations ipmr_mfc_seq_ops = {
+	.start = ipmr_mfc_seq_start,
+	.next  = ipmr_mfc_seq_next,
+	.stop  = ipmr_mfc_seq_stop,
+	.show  = ipmr_mfc_seq_show,
+};
+
+static int ipmr_mfc_open(struct inode *inode, struct file *file)
+{
+	return seq_open_private(file, &ipmr_mfc_seq_ops,
+			sizeof(struct ipmr_mfc_iter));
+}
+
+static const struct file_operations ipmr_mfc_fops = {
+	.owner	 = THIS_MODULE,
+	.open    = ipmr_mfc_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release_private,
+};
+#endif
+
+#ifdef CONFIG_IP_PIMSM_V2
+static struct net_protocol pim_protocol = {
+	.handler	=	pim_rcv,
+};
+#endif
+
+
+/*
+ *	Setup for IP multicast routing
+ */
+
+int __init ip_mr_init(void)
+{
+	int err;
+
+	mrt_cachep = kmem_cache_create("ip_mrt_cache",
+				       sizeof(struct mfc_cache),
+				       0, SLAB_HWCACHE_ALIGN|SLAB_PANIC,
+				       NULL);
+	if (!mrt_cachep)
+		return -ENOMEM;
+
+	setup_timer(&ipmr_expire_timer, ipmr_expire_process, 0);
+	err = register_netdevice_notifier(&ip_mr_notifier);
+	if (err)
+		goto reg_notif_fail;
+#ifdef CONFIG_PROC_FS
+	err = -ENOMEM;
+	if (!proc_net_fops_create(&init_net, "ip_mr_vif", 0, &ipmr_vif_fops))
+		goto proc_vif_fail;
+	if (!proc_net_fops_create(&init_net, "ip_mr_cache", 0, &ipmr_mfc_fops))
+		goto proc_cache_fail;
+#endif
+	return 0;
+#ifdef CONFIG_PROC_FS
+proc_cache_fail:
+	proc_net_remove(&init_net, "ip_mr_vif");
+proc_vif_fail:
+	unregister_netdevice_notifier(&ip_mr_notifier);
+#endif
+reg_notif_fail:
+	del_timer(&ipmr_expire_timer);
+	kmem_cache_destroy(mrt_cachep);
+	return err;
+}
diff --git a/net/ipv4/netfilter.c b/net/ipv4/netfilter.c
new file mode 100644
index 0000000..6efdb70
--- /dev/null
+++ b/net/ipv4/netfilter.c
@@ -0,0 +1,250 @@
+/* IPv4 specific functions of netfilter core */
+#include <linux/kernel.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/ip.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+#include <net/netfilter/nf_queue.h>
+
+/* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
+int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
+{
+	struct net *net = dev_net(skb->dst->dev);
+	const struct iphdr *iph = ip_hdr(skb);
+	struct rtable *rt;
+	struct flowi fl = {};
+	struct dst_entry *odst;
+	unsigned int hh_len;
+	unsigned int type;
+
+	type = inet_addr_type(net, iph->saddr);
+	if (skb->sk && inet_sk(skb->sk)->transparent)
+		type = RTN_LOCAL;
+	if (addr_type == RTN_UNSPEC)
+		addr_type = type;
+
+	/* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
+	 * packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook.
+	 */
+	if (addr_type == RTN_LOCAL) {
+		fl.nl_u.ip4_u.daddr = iph->daddr;
+		if (type == RTN_LOCAL)
+			fl.nl_u.ip4_u.saddr = iph->saddr;
+		fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
+		fl.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0;
+		fl.mark = skb->mark;
+		fl.flags = skb->sk ? inet_sk_flowi_flags(skb->sk) : 0;
+		if (ip_route_output_key(net, &rt, &fl) != 0)
+			return -1;
+
+		/* Drop old route. */
+		dst_release(skb->dst);
+		skb->dst = &rt->u.dst;
+	} else {
+		/* non-local src, find valid iif to satisfy
+		 * rp-filter when calling ip_route_input. */
+		fl.nl_u.ip4_u.daddr = iph->saddr;
+		if (ip_route_output_key(net, &rt, &fl) != 0)
+			return -1;
+
+		odst = skb->dst;
+		if (ip_route_input(skb, iph->daddr, iph->saddr,
+				   RT_TOS(iph->tos), rt->u.dst.dev) != 0) {
+			dst_release(&rt->u.dst);
+			return -1;
+		}
+		dst_release(&rt->u.dst);
+		dst_release(odst);
+	}
+
+	if (skb->dst->error)
+		return -1;
+
+#ifdef CONFIG_XFRM
+	if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
+	    xfrm_decode_session(skb, &fl, AF_INET) == 0)
+		if (xfrm_lookup(&skb->dst, &fl, skb->sk, 0))
+			return -1;
+#endif
+
+	/* Change in oif may mean change in hh_len. */
+	hh_len = skb->dst->dev->hard_header_len;
+	if (skb_headroom(skb) < hh_len &&
+	    pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
+		return -1;
+
+	return 0;
+}
+EXPORT_SYMBOL(ip_route_me_harder);
+
+#ifdef CONFIG_XFRM
+int ip_xfrm_me_harder(struct sk_buff *skb)
+{
+	struct flowi fl;
+	unsigned int hh_len;
+	struct dst_entry *dst;
+
+	if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
+		return 0;
+	if (xfrm_decode_session(skb, &fl, AF_INET) < 0)
+		return -1;
+
+	dst = skb->dst;
+	if (dst->xfrm)
+		dst = ((struct xfrm_dst *)dst)->route;
+	dst_hold(dst);
+
+	if (xfrm_lookup(&dst, &fl, skb->sk, 0) < 0)
+		return -1;
+
+	dst_release(skb->dst);
+	skb->dst = dst;
+
+	/* Change in oif may mean change in hh_len. */
+	hh_len = skb->dst->dev->hard_header_len;
+	if (skb_headroom(skb) < hh_len &&
+	    pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
+		return -1;
+	return 0;
+}
+EXPORT_SYMBOL(ip_xfrm_me_harder);
+#endif
+
+void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
+EXPORT_SYMBOL(ip_nat_decode_session);
+
+/*
+ * Extra routing may needed on local out, as the QUEUE target never
+ * returns control to the table.
+ */
+
+struct ip_rt_info {
+	__be32 daddr;
+	__be32 saddr;
+	u_int8_t tos;
+};
+
+static void nf_ip_saveroute(const struct sk_buff *skb,
+			    struct nf_queue_entry *entry)
+{
+	struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
+
+	if (entry->hook == NF_INET_LOCAL_OUT) {
+		const struct iphdr *iph = ip_hdr(skb);
+
+		rt_info->tos = iph->tos;
+		rt_info->daddr = iph->daddr;
+		rt_info->saddr = iph->saddr;
+	}
+}
+
+static int nf_ip_reroute(struct sk_buff *skb,
+			 const struct nf_queue_entry *entry)
+{
+	const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
+
+	if (entry->hook == NF_INET_LOCAL_OUT) {
+		const struct iphdr *iph = ip_hdr(skb);
+
+		if (!(iph->tos == rt_info->tos
+		      && iph->daddr == rt_info->daddr
+		      && iph->saddr == rt_info->saddr))
+			return ip_route_me_harder(skb, RTN_UNSPEC);
+	}
+	return 0;
+}
+
+__sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
+			    unsigned int dataoff, u_int8_t protocol)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	__sum16 csum = 0;
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
+			break;
+		if ((protocol == 0 && !csum_fold(skb->csum)) ||
+		    !csum_tcpudp_magic(iph->saddr, iph->daddr,
+				       skb->len - dataoff, protocol,
+				       skb->csum)) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			break;
+		}
+		/* fall through */
+	case CHECKSUM_NONE:
+		if (protocol == 0)
+			skb->csum = 0;
+		else
+			skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
+						       skb->len - dataoff,
+						       protocol, 0);
+		csum = __skb_checksum_complete(skb);
+	}
+	return csum;
+}
+EXPORT_SYMBOL(nf_ip_checksum);
+
+static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
+				      unsigned int dataoff, unsigned int len,
+				      u_int8_t protocol)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	__sum16 csum = 0;
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (len == skb->len - dataoff)
+			return nf_ip_checksum(skb, hook, dataoff, protocol);
+		/* fall through */
+	case CHECKSUM_NONE:
+		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
+					       skb->len - dataoff, 0);
+		skb->ip_summed = CHECKSUM_NONE;
+		csum = __skb_checksum_complete_head(skb, dataoff + len);
+		if (!csum)
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+	return csum;
+}
+
+static int nf_ip_route(struct dst_entry **dst, struct flowi *fl)
+{
+	return ip_route_output_key(&init_net, (struct rtable **)dst, fl);
+}
+
+static const struct nf_afinfo nf_ip_afinfo = {
+	.family			= AF_INET,
+	.checksum		= nf_ip_checksum,
+	.checksum_partial	= nf_ip_checksum_partial,
+	.route			= nf_ip_route,
+	.saveroute		= nf_ip_saveroute,
+	.reroute		= nf_ip_reroute,
+	.route_key_size		= sizeof(struct ip_rt_info),
+};
+
+static int ipv4_netfilter_init(void)
+{
+	return nf_register_afinfo(&nf_ip_afinfo);
+}
+
+static void ipv4_netfilter_fini(void)
+{
+	nf_unregister_afinfo(&nf_ip_afinfo);
+}
+
+module_init(ipv4_netfilter_init);
+module_exit(ipv4_netfilter_fini);
+
+#ifdef CONFIG_SYSCTL
+struct ctl_path nf_net_ipv4_netfilter_sysctl_path[] = {
+	{ .procname = "net", .ctl_name = CTL_NET, },
+	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
+	{ .procname = "netfilter", .ctl_name = NET_IPV4_NETFILTER, },
+	{ }
+};
+EXPORT_SYMBOL_GPL(nf_net_ipv4_netfilter_sysctl_path);
+#endif /* CONFIG_SYSCTL */
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
new file mode 100644
index 0000000..3816e1d
--- /dev/null
+++ b/net/ipv4/netfilter/Kconfig
@@ -0,0 +1,398 @@
+#
+# IP netfilter configuration
+#
+
+menu "IP: Netfilter Configuration"
+	depends on INET && NETFILTER
+
+config NF_DEFRAG_IPV4
+	tristate
+	default n
+
+config NF_CONNTRACK_IPV4
+	tristate "IPv4 connection tracking support (required for NAT)"
+	depends on NF_CONNTRACK
+	default m if NETFILTER_ADVANCED=n
+	select NF_DEFRAG_IPV4
+	---help---
+	  Connection tracking keeps a record of what packets have passed
+	  through your machine, in order to figure out how they are related
+	  into connections.
+
+	  This is IPv4 support on Layer 3 independent connection tracking.
+	  Layer 3 independent connection tracking is experimental scheme
+	  which generalize ip_conntrack to support other layer 3 protocols.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NF_CONNTRACK_PROC_COMPAT
+	bool "proc/sysctl compatibility with old connection tracking"
+	depends on NF_CONNTRACK_IPV4
+	default y
+	help
+	  This option enables /proc and sysctl compatibility with the old
+	  layer 3 dependant connection tracking. This is needed to keep
+	  old programs that have not been adapted to the new names working.
+
+	  If unsure, say Y.
+
+config IP_NF_QUEUE
+	tristate "IP Userspace queueing via NETLINK (OBSOLETE)"
+	depends on NETFILTER_ADVANCED
+	help
+	  Netfilter has the ability to queue packets to user space: the
+	  netlink device can be used to access them using this driver.
+
+	  This option enables the old IPv4-only "ip_queue" implementation
+	  which has been obsoleted by the new "nfnetlink_queue" code (see
+	  CONFIG_NETFILTER_NETLINK_QUEUE).
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_IPTABLES
+	tristate "IP tables support (required for filtering/masq/NAT)"
+	default m if NETFILTER_ADVANCED=n
+	select NETFILTER_XTABLES
+	help
+	  iptables is a general, extensible packet identification framework.
+	  The packet filtering and full NAT (masquerading, port forwarding,
+	  etc) subsystems now use this: say `Y' or `M' here if you want to use
+	  either of those.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+if IP_NF_IPTABLES
+
+# The matches.
+config IP_NF_MATCH_ADDRTYPE
+	tristate '"addrtype" address type match support'
+	depends on NETFILTER_ADVANCED
+	help
+	  This option allows you to match what routing thinks of an address,
+	  eg. UNICAST, LOCAL, BROADCAST, ...
+
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
+
+config IP_NF_MATCH_AH
+	tristate '"ah" match support'
+	depends on NETFILTER_ADVANCED
+	help
+	  This match extension allows you to match a range of SPIs
+	  inside AH header of IPSec packets.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_MATCH_ECN
+	tristate '"ecn" match support'
+	depends on NETFILTER_ADVANCED
+	help
+	  This option adds a `ECN' match, which allows you to match against
+	  the IPv4 and TCP header ECN fields.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_MATCH_TTL
+	tristate '"ttl" match support'
+	depends on NETFILTER_ADVANCED
+	help
+	  This adds CONFIG_IP_NF_MATCH_TTL option, which enabled the user
+	  to match packets by their TTL value.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+# `filter', generic and specific targets
+config IP_NF_FILTER
+	tristate "Packet filtering"
+	default m if NETFILTER_ADVANCED=n
+	help
+	  Packet filtering defines a table `filter', which has a series of
+	  rules for simple packet filtering at local input, forwarding and
+	  local output.  See the man page for iptables(8).
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_REJECT
+	tristate "REJECT target support"
+	depends on IP_NF_FILTER
+	default m if NETFILTER_ADVANCED=n
+	help
+	  The REJECT target allows a filtering rule to specify that an ICMP
+	  error should be issued in response to an incoming packet, rather
+	  than silently being dropped.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_LOG
+	tristate "LOG target support"
+	default m if NETFILTER_ADVANCED=n
+	help
+	  This option adds a `LOG' target, which allows you to create rules in
+	  any iptables table which records the packet header to the syslog.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_ULOG
+	tristate "ULOG target support"
+	default m if NETFILTER_ADVANCED=n
+	---help---
+
+	  This option enables the old IPv4-only "ipt_ULOG" implementation
+	  which has been obsoleted by the new "nfnetlink_log" code (see
+	  CONFIG_NETFILTER_NETLINK_LOG).
+
+	  This option adds a `ULOG' target, which allows you to create rules in
+	  any iptables table. The packet is passed to a userspace logging
+	  daemon using netlink multicast sockets; unlike the LOG target
+	  which can only be viewed through syslog.
+
+	  The appropriate userspace logging daemon (ulogd) may be obtained from
+	  <http://www.gnumonks.org/projects/ulogd/>
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+# NAT + specific targets: nf_conntrack
+config NF_NAT
+	tristate "Full NAT"
+	depends on NF_CONNTRACK_IPV4
+	default m if NETFILTER_ADVANCED=n
+	help
+	  The Full NAT option allows masquerading, port forwarding and other
+	  forms of full Network Address Port Translation.  It is controlled by
+	  the `nat' table in iptables: see the man page for iptables(8).
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NF_NAT_NEEDED
+	bool
+	depends on NF_NAT
+	default y
+
+config IP_NF_TARGET_MASQUERADE
+	tristate "MASQUERADE target support"
+	depends on NF_NAT
+	default m if NETFILTER_ADVANCED=n
+	help
+	  Masquerading is a special case of NAT: all outgoing connections are
+	  changed to seem to come from a particular interface's address, and
+	  if the interface goes down, those connections are lost.  This is
+	  only useful for dialup accounts with dynamic IP address (ie. your IP
+	  address will be different on next dialup).
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_NETMAP
+	tristate "NETMAP target support"
+	depends on NF_NAT
+	depends on NETFILTER_ADVANCED
+	help
+	  NETMAP is an implementation of static 1:1 NAT mapping of network
+	  addresses. It maps the network address part, while keeping the host
+	  address part intact.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_REDIRECT
+	tristate "REDIRECT target support"
+	depends on NF_NAT
+	depends on NETFILTER_ADVANCED
+	help
+	  REDIRECT is a special case of NAT: all incoming connections are
+	  mapped onto the incoming interface's address, causing the packets to
+	  come to the local machine instead of passing through.  This is
+	  useful for transparent proxies.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config NF_NAT_SNMP_BASIC
+	tristate "Basic SNMP-ALG support"
+	depends on NF_NAT
+	depends on NETFILTER_ADVANCED
+	---help---
+
+	  This module implements an Application Layer Gateway (ALG) for
+	  SNMP payloads.  In conjunction with NAT, it allows a network
+	  management system to access multiple private networks with
+	  conflicting addresses.  It works by modifying IP addresses
+	  inside SNMP payloads to match IP-layer NAT mapping.
+
+	  This is the "basic" form of SNMP-ALG, as described in RFC 2962
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+# If they want FTP, set to $CONFIG_IP_NF_NAT (m or y),
+# or $CONFIG_IP_NF_FTP (m or y), whichever is weaker.
+# From kconfig-language.txt:
+#
+#           <expr> '&&' <expr>                   (6)
+#
+# (6) Returns the result of min(/expr/, /expr/).
+config NF_NAT_PROTO_DCCP
+	tristate
+	depends on NF_NAT && NF_CT_PROTO_DCCP
+	default NF_NAT && NF_CT_PROTO_DCCP
+
+config NF_NAT_PROTO_GRE
+	tristate
+	depends on NF_NAT && NF_CT_PROTO_GRE
+
+config NF_NAT_PROTO_UDPLITE
+	tristate
+	depends on NF_NAT && NF_CT_PROTO_UDPLITE
+	default NF_NAT && NF_CT_PROTO_UDPLITE
+
+config NF_NAT_PROTO_SCTP
+	tristate
+	default NF_NAT && NF_CT_PROTO_SCTP
+	depends on NF_NAT && NF_CT_PROTO_SCTP
+	select LIBCRC32C
+
+config NF_NAT_FTP
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_FTP
+
+config NF_NAT_IRC
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_IRC
+
+config NF_NAT_TFTP
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_TFTP
+
+config NF_NAT_AMANDA
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_AMANDA
+
+config NF_NAT_PPTP
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_PPTP
+	select NF_NAT_PROTO_GRE
+
+config NF_NAT_H323
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_H323
+
+config NF_NAT_SIP
+	tristate
+	depends on NF_CONNTRACK && NF_NAT
+	default NF_NAT && NF_CONNTRACK_SIP
+
+# mangle + specific targets
+config IP_NF_MANGLE
+	tristate "Packet mangling"
+	default m if NETFILTER_ADVANCED=n
+	help
+	  This option adds a `mangle' table to iptables: see the man page for
+	  iptables(8).  This table is used for various packet alterations
+	  which can effect how the packet is routed.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_CLUSTERIP
+	tristate "CLUSTERIP target support (EXPERIMENTAL)"
+	depends on IP_NF_MANGLE && EXPERIMENTAL
+	depends on NF_CONNTRACK_IPV4
+	depends on NETFILTER_ADVANCED
+	select NF_CONNTRACK_MARK
+	help
+	  The CLUSTERIP target allows you to build load-balancing clusters of
+	  network servers without having a dedicated load-balancing
+	  router/server/switch.
+	
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_ECN
+	tristate "ECN target support"
+	depends on IP_NF_MANGLE
+	depends on NETFILTER_ADVANCED
+	---help---
+	  This option adds a `ECN' target, which can be used in the iptables mangle
+	  table.  
+
+	  You can use this target to remove the ECN bits from the IPv4 header of
+	  an IP packet.  This is particularly useful, if you need to work around
+	  existing ECN blackholes on the internet, but don't want to disable
+	  ECN support in general.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_TARGET_TTL
+	tristate  'TTL target support'
+	depends on IP_NF_MANGLE
+	depends on NETFILTER_ADVANCED
+	help
+	  This option adds a `TTL' target, which enables the user to modify
+	  the TTL value of the IP header.
+
+	  While it is safe to decrement/lower the TTL, this target also enables
+	  functionality to increment and set the TTL value of the IP header to
+	  arbitrary values.  This is EXTREMELY DANGEROUS since you can easily
+	  create immortal packets that loop forever on the network.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+# raw + specific targets
+config IP_NF_RAW
+	tristate  'raw table support (required for NOTRACK/TRACE)'
+	depends on NETFILTER_ADVANCED
+	help
+	  This option adds a `raw' table to iptables. This table is the very
+	  first in the netfilter framework and hooks in at the PREROUTING
+	  and OUTPUT chains.
+	
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
+
+# security table for MAC policy
+config IP_NF_SECURITY
+	tristate "Security table"
+	depends on SECURITY
+	depends on NETFILTER_ADVANCED
+	help
+	  This option adds a `security' table to iptables, for use
+	  with Mandatory Access Control (MAC) policy.
+	 
+	  If unsure, say N.
+
+endif # IP_NF_IPTABLES
+
+# ARP tables
+config IP_NF_ARPTABLES
+	tristate "ARP tables support"
+	select NETFILTER_XTABLES
+	depends on NETFILTER_ADVANCED
+	help
+	  arptables is a general, extensible packet identification framework.
+	  The ARP packet filtering and mangling (manipulation)subsystems
+	  use this: say Y or M here if you want to use either of those.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+if IP_NF_ARPTABLES
+
+config IP_NF_ARPFILTER
+	tristate "ARP packet filtering"
+	help
+	  ARP packet filtering defines a table `filter', which has a series of
+	  rules for simple ARP packet filtering at local input and
+	  local output.  On a bridge, you can also specify filtering rules
+	  for forwarded ARP packets. See the man page for arptables(8).
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
+config IP_NF_ARP_MANGLE
+	tristate "ARP payload mangling"
+	help
+	  Allows altering the ARP packet payload: source and destination
+	  hardware and network addresses.
+
+endif # IP_NF_ARPTABLES
+
+endmenu
+
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
new file mode 100644
index 0000000..5f9b650
--- /dev/null
+++ b/net/ipv4/netfilter/Makefile
@@ -0,0 +1,75 @@
+#
+# Makefile for the netfilter modules on top of IPv4.
+#
+
+# objects for l3 independent conntrack
+nf_conntrack_ipv4-objs  :=  nf_conntrack_l3proto_ipv4.o nf_conntrack_proto_icmp.o
+ifeq ($(CONFIG_NF_CONNTRACK_PROC_COMPAT),y)
+ifeq ($(CONFIG_PROC_FS),y)
+nf_conntrack_ipv4-objs	+= nf_conntrack_l3proto_ipv4_compat.o
+endif
+endif
+
+nf_nat-objs		:= nf_nat_core.o nf_nat_helper.o nf_nat_proto_unknown.o nf_nat_proto_common.o nf_nat_proto_tcp.o nf_nat_proto_udp.o nf_nat_proto_icmp.o
+iptable_nat-objs	:= nf_nat_rule.o nf_nat_standalone.o
+
+# connection tracking
+obj-$(CONFIG_NF_CONNTRACK_IPV4) += nf_conntrack_ipv4.o
+
+obj-$(CONFIG_NF_NAT) += nf_nat.o
+
+# defrag
+obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o
+
+# NAT helpers (nf_conntrack)
+obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_amanda.o
+obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
+obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o
+obj-$(CONFIG_NF_NAT_IRC) += nf_nat_irc.o
+obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o
+obj-$(CONFIG_NF_NAT_SIP) += nf_nat_sip.o
+obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o
+obj-$(CONFIG_NF_NAT_TFTP) += nf_nat_tftp.o
+
+# NAT protocols (nf_nat)
+obj-$(CONFIG_NF_NAT_PROTO_DCCP) += nf_nat_proto_dccp.o
+obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o
+obj-$(CONFIG_NF_NAT_PROTO_UDPLITE) += nf_nat_proto_udplite.o
+obj-$(CONFIG_NF_NAT_PROTO_SCTP) += nf_nat_proto_sctp.o
+
+# generic IP tables 
+obj-$(CONFIG_IP_NF_IPTABLES) += ip_tables.o
+
+# the three instances of ip_tables
+obj-$(CONFIG_IP_NF_FILTER) += iptable_filter.o
+obj-$(CONFIG_IP_NF_MANGLE) += iptable_mangle.o
+obj-$(CONFIG_NF_NAT) += iptable_nat.o
+obj-$(CONFIG_IP_NF_RAW) += iptable_raw.o
+obj-$(CONFIG_IP_NF_SECURITY) += iptable_security.o
+
+# matches
+obj-$(CONFIG_IP_NF_MATCH_ADDRTYPE) += ipt_addrtype.o
+obj-$(CONFIG_IP_NF_MATCH_AH) += ipt_ah.o
+obj-$(CONFIG_IP_NF_MATCH_ECN) += ipt_ecn.o
+obj-$(CONFIG_IP_NF_MATCH_TTL) += ipt_ttl.o
+
+# targets
+obj-$(CONFIG_IP_NF_TARGET_CLUSTERIP) += ipt_CLUSTERIP.o
+obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_ECN.o
+obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
+obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
+obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
+obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
+obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
+obj-$(CONFIG_IP_NF_TARGET_TTL) += ipt_TTL.o
+obj-$(CONFIG_IP_NF_TARGET_ULOG) += ipt_ULOG.o
+
+# generic ARP tables
+obj-$(CONFIG_IP_NF_ARPTABLES) += arp_tables.o
+obj-$(CONFIG_IP_NF_ARP_MANGLE) += arpt_mangle.o
+
+# just filtering instance of ARP tables for now
+obj-$(CONFIG_IP_NF_ARPFILTER) += arptable_filter.o
+
+obj-$(CONFIG_IP_NF_QUEUE) += ip_queue.o
+
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
new file mode 100644
index 0000000..8d70d29
--- /dev/null
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -0,0 +1,1892 @@
+/*
+ * Packet matching code for ARP packets.
+ *
+ * Based heavily, if not almost entirely, upon ip_tables.c framework.
+ *
+ * Some ARP specific bits are:
+ *
+ * Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/capability.h>
+#include <linux/if_arp.h>
+#include <linux/kmod.h>
+#include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <net/compat.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_arp/arp_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
+MODULE_DESCRIPTION("arptables core");
+
+/*#define DEBUG_ARP_TABLES*/
+/*#define DEBUG_ARP_TABLES_USER*/
+
+#ifdef DEBUG_ARP_TABLES
+#define dprintf(format, args...)  printk(format , ## args)
+#else
+#define dprintf(format, args...)
+#endif
+
+#ifdef DEBUG_ARP_TABLES_USER
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+#ifdef CONFIG_NETFILTER_DEBUG
+#define ARP_NF_ASSERT(x)					\
+do {								\
+	if (!(x))						\
+		printk("ARP_NF_ASSERT: %s:%s:%u\n",		\
+		       __func__, __FILE__, __LINE__);	\
+} while(0)
+#else
+#define ARP_NF_ASSERT(x)
+#endif
+
+static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
+				      const char *hdr_addr, int len)
+{
+	int i, ret;
+
+	if (len > ARPT_DEV_ADDR_LEN_MAX)
+		len = ARPT_DEV_ADDR_LEN_MAX;
+
+	ret = 0;
+	for (i = 0; i < len; i++)
+		ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
+
+	return (ret != 0);
+}
+
+/* Returns whether packet matches rule or not. */
+static inline int arp_packet_match(const struct arphdr *arphdr,
+				   struct net_device *dev,
+				   const char *indev,
+				   const char *outdev,
+				   const struct arpt_arp *arpinfo)
+{
+	const char *arpptr = (char *)(arphdr + 1);
+	const char *src_devaddr, *tgt_devaddr;
+	__be32 src_ipaddr, tgt_ipaddr;
+	int i, ret;
+
+#define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
+
+	if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
+		  ARPT_INV_ARPOP)) {
+		dprintf("ARP operation field mismatch.\n");
+		dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
+			arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
+		return 0;
+	}
+
+	if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
+		  ARPT_INV_ARPHRD)) {
+		dprintf("ARP hardware address format mismatch.\n");
+		dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
+			arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
+		return 0;
+	}
+
+	if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
+		  ARPT_INV_ARPPRO)) {
+		dprintf("ARP protocol address format mismatch.\n");
+		dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
+			arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
+		return 0;
+	}
+
+	if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
+		  ARPT_INV_ARPHLN)) {
+		dprintf("ARP hardware address length mismatch.\n");
+		dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
+			arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
+		return 0;
+	}
+
+	src_devaddr = arpptr;
+	arpptr += dev->addr_len;
+	memcpy(&src_ipaddr, arpptr, sizeof(u32));
+	arpptr += sizeof(u32);
+	tgt_devaddr = arpptr;
+	arpptr += dev->addr_len;
+	memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
+
+	if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
+		  ARPT_INV_SRCDEVADDR) ||
+	    FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
+		  ARPT_INV_TGTDEVADDR)) {
+		dprintf("Source or target device address mismatch.\n");
+
+		return 0;
+	}
+
+	if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
+		  ARPT_INV_SRCIP) ||
+	    FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
+		  ARPT_INV_TGTIP)) {
+		dprintf("Source or target IP address mismatch.\n");
+
+		dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
+			NIPQUAD(src_ipaddr),
+			NIPQUAD(arpinfo->smsk.s_addr),
+			NIPQUAD(arpinfo->src.s_addr),
+			arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
+		dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
+			NIPQUAD(tgt_ipaddr),
+			NIPQUAD(arpinfo->tmsk.s_addr),
+			NIPQUAD(arpinfo->tgt.s_addr),
+			arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
+		return 0;
+	}
+
+	/* Look for ifname matches.  */
+	for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
+		ret |= (indev[i] ^ arpinfo->iniface[i])
+			& arpinfo->iniface_mask[i];
+	}
+
+	if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
+		dprintf("VIA in mismatch (%s vs %s).%s\n",
+			indev, arpinfo->iniface,
+			arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
+		return 0;
+	}
+
+	for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
+		ret |= (outdev[i] ^ arpinfo->outiface[i])
+			& arpinfo->outiface_mask[i];
+	}
+
+	if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
+		dprintf("VIA out mismatch (%s vs %s).%s\n",
+			outdev, arpinfo->outiface,
+			arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
+		return 0;
+	}
+
+	return 1;
+#undef FWINV
+}
+
+static inline int arp_checkentry(const struct arpt_arp *arp)
+{
+	if (arp->flags & ~ARPT_F_MASK) {
+		duprintf("Unknown flag bits set: %08X\n",
+			 arp->flags & ~ARPT_F_MASK);
+		return 0;
+	}
+	if (arp->invflags & ~ARPT_INV_MASK) {
+		duprintf("Unknown invflag bits set: %08X\n",
+			 arp->invflags & ~ARPT_INV_MASK);
+		return 0;
+	}
+
+	return 1;
+}
+
+static unsigned int
+arpt_error(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	if (net_ratelimit())
+		printk("arp_tables: error: '%s'\n",
+		       (const char *)par->targinfo);
+
+	return NF_DROP;
+}
+
+static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
+{
+	return (struct arpt_entry *)(base + offset);
+}
+
+unsigned int arpt_do_table(struct sk_buff *skb,
+			   unsigned int hook,
+			   const struct net_device *in,
+			   const struct net_device *out,
+			   struct xt_table *table)
+{
+	static const char nulldevname[IFNAMSIZ];
+	unsigned int verdict = NF_DROP;
+	const struct arphdr *arp;
+	bool hotdrop = false;
+	struct arpt_entry *e, *back;
+	const char *indev, *outdev;
+	void *table_base;
+	const struct xt_table_info *private;
+	struct xt_target_param tgpar;
+
+	if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
+		return NF_DROP;
+
+	indev = in ? in->name : nulldevname;
+	outdev = out ? out->name : nulldevname;
+
+	read_lock_bh(&table->lock);
+	private = table->private;
+	table_base = (void *)private->entries[smp_processor_id()];
+	e = get_entry(table_base, private->hook_entry[hook]);
+	back = get_entry(table_base, private->underflow[hook]);
+
+	tgpar.in      = in;
+	tgpar.out     = out;
+	tgpar.hooknum = hook;
+	tgpar.family  = NFPROTO_ARP;
+
+	arp = arp_hdr(skb);
+	do {
+		if (arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
+			struct arpt_entry_target *t;
+			int hdr_len;
+
+			hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
+				(2 * skb->dev->addr_len);
+			ADD_COUNTER(e->counters, hdr_len, 1);
+
+			t = arpt_get_target(e);
+
+			/* Standard target? */
+			if (!t->u.kernel.target->target) {
+				int v;
+
+				v = ((struct arpt_standard_target *)t)->verdict;
+				if (v < 0) {
+					/* Pop from stack? */
+					if (v != ARPT_RETURN) {
+						verdict = (unsigned)(-v) - 1;
+						break;
+					}
+					e = back;
+					back = get_entry(table_base,
+							 back->comefrom);
+					continue;
+				}
+				if (table_base + v
+				    != (void *)e + e->next_offset) {
+					/* Save old back ptr in next entry */
+					struct arpt_entry *next
+						= (void *)e + e->next_offset;
+					next->comefrom =
+						(void *)back - table_base;
+
+					/* set back pointer to next entry */
+					back = next;
+				}
+
+				e = get_entry(table_base, v);
+			} else {
+				/* Targets which reenter must return
+				 * abs. verdicts
+				 */
+				tgpar.target   = t->u.kernel.target;
+				tgpar.targinfo = t->data;
+				verdict = t->u.kernel.target->target(skb,
+								     &tgpar);
+
+				/* Target might have changed stuff. */
+				arp = arp_hdr(skb);
+
+				if (verdict == ARPT_CONTINUE)
+					e = (void *)e + e->next_offset;
+				else
+					/* Verdict */
+					break;
+			}
+		} else {
+			e = (void *)e + e->next_offset;
+		}
+	} while (!hotdrop);
+	read_unlock_bh(&table->lock);
+
+	if (hotdrop)
+		return NF_DROP;
+	else
+		return verdict;
+}
+
+/* All zeroes == unconditional rule. */
+static inline int unconditional(const struct arpt_arp *arp)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
+		if (((__u32 *)arp)[i])
+			return 0;
+
+	return 1;
+}
+
+/* Figures out from what hook each rule can be called: returns 0 if
+ * there are loops.  Puts hook bitmask in comefrom.
+ */
+static int mark_source_chains(struct xt_table_info *newinfo,
+			      unsigned int valid_hooks, void *entry0)
+{
+	unsigned int hook;
+
+	/* No recursion; use packet counter to save back ptrs (reset
+	 * to 0 as we leave), and comefrom to save source hook bitmask.
+	 */
+	for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
+		unsigned int pos = newinfo->hook_entry[hook];
+		struct arpt_entry *e
+			= (struct arpt_entry *)(entry0 + pos);
+
+		if (!(valid_hooks & (1 << hook)))
+			continue;
+
+		/* Set initial back pointer. */
+		e->counters.pcnt = pos;
+
+		for (;;) {
+			const struct arpt_standard_target *t
+				= (void *)arpt_get_target(e);
+			int visited = e->comefrom & (1 << hook);
+
+			if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
+				printk("arptables: loop hook %u pos %u %08X.\n",
+				       hook, pos, e->comefrom);
+				return 0;
+			}
+			e->comefrom
+				|= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
+
+			/* Unconditional return/END. */
+			if ((e->target_offset == sizeof(struct arpt_entry)
+			    && (strcmp(t->target.u.user.name,
+				       ARPT_STANDARD_TARGET) == 0)
+			    && t->verdict < 0
+			    && unconditional(&e->arp)) || visited) {
+				unsigned int oldpos, size;
+
+				if (t->verdict < -NF_MAX_VERDICT - 1) {
+					duprintf("mark_source_chains: bad "
+						"negative verdict (%i)\n",
+								t->verdict);
+					return 0;
+				}
+
+				/* Return: backtrack through the last
+				 * big jump.
+				 */
+				do {
+					e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
+					oldpos = pos;
+					pos = e->counters.pcnt;
+					e->counters.pcnt = 0;
+
+					/* We're at the start. */
+					if (pos == oldpos)
+						goto next;
+
+					e = (struct arpt_entry *)
+						(entry0 + pos);
+				} while (oldpos == pos + e->next_offset);
+
+				/* Move along one */
+				size = e->next_offset;
+				e = (struct arpt_entry *)
+					(entry0 + pos + size);
+				e->counters.pcnt = pos;
+				pos += size;
+			} else {
+				int newpos = t->verdict;
+
+				if (strcmp(t->target.u.user.name,
+					   ARPT_STANDARD_TARGET) == 0
+				    && newpos >= 0) {
+					if (newpos > newinfo->size -
+						sizeof(struct arpt_entry)) {
+						duprintf("mark_source_chains: "
+							"bad verdict (%i)\n",
+								newpos);
+						return 0;
+					}
+
+					/* This a jump; chase it. */
+					duprintf("Jump rule %u -> %u\n",
+						 pos, newpos);
+				} else {
+					/* ... this is a fallthru */
+					newpos = pos + e->next_offset;
+				}
+				e = (struct arpt_entry *)
+					(entry0 + newpos);
+				e->counters.pcnt = pos;
+				pos = newpos;
+			}
+		}
+		next:
+		duprintf("Finished chain %u\n", hook);
+	}
+	return 1;
+}
+
+static inline int check_entry(struct arpt_entry *e, const char *name)
+{
+	const struct arpt_entry_target *t;
+
+	if (!arp_checkentry(&e->arp)) {
+		duprintf("arp_tables: arp check failed %p %s.\n", e, name);
+		return -EINVAL;
+	}
+
+	if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset)
+		return -EINVAL;
+
+	t = arpt_get_target(e);
+	if (e->target_offset + t->u.target_size > e->next_offset)
+		return -EINVAL;
+
+	return 0;
+}
+
+static inline int check_target(struct arpt_entry *e, const char *name)
+{
+	struct arpt_entry_target *t = arpt_get_target(e);
+	int ret;
+	struct xt_tgchk_param par = {
+		.table     = name,
+		.entryinfo = e,
+		.target    = t->u.kernel.target,
+		.targinfo  = t->data,
+		.hook_mask = e->comefrom,
+		.family    = NFPROTO_ARP,
+	};
+
+	ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
+	if (ret < 0) {
+		duprintf("arp_tables: check failed for `%s'.\n",
+			 t->u.kernel.target->name);
+		return ret;
+	}
+	return 0;
+}
+
+static inline int
+find_check_entry(struct arpt_entry *e, const char *name, unsigned int size,
+		 unsigned int *i)
+{
+	struct arpt_entry_target *t;
+	struct xt_target *target;
+	int ret;
+
+	ret = check_entry(e, name);
+	if (ret)
+		return ret;
+
+	t = arpt_get_target(e);
+	target = try_then_request_module(xt_find_target(NFPROTO_ARP,
+							t->u.user.name,
+							t->u.user.revision),
+					 "arpt_%s", t->u.user.name);
+	if (IS_ERR(target) || !target) {
+		duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
+		ret = target ? PTR_ERR(target) : -ENOENT;
+		goto out;
+	}
+	t->u.kernel.target = target;
+
+	ret = check_target(e, name);
+	if (ret)
+		goto err;
+
+	(*i)++;
+	return 0;
+err:
+	module_put(t->u.kernel.target->me);
+out:
+	return ret;
+}
+
+static inline int check_entry_size_and_hooks(struct arpt_entry *e,
+					     struct xt_table_info *newinfo,
+					     unsigned char *base,
+					     unsigned char *limit,
+					     const unsigned int *hook_entries,
+					     const unsigned int *underflows,
+					     unsigned int *i)
+{
+	unsigned int h;
+
+	if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
+	    || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
+		duprintf("Bad offset %p\n", e);
+		return -EINVAL;
+	}
+
+	if (e->next_offset
+	    < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
+		duprintf("checking: element %p size %u\n",
+			 e, e->next_offset);
+		return -EINVAL;
+	}
+
+	/* Check hooks & underflows */
+	for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
+		if ((unsigned char *)e - base == hook_entries[h])
+			newinfo->hook_entry[h] = hook_entries[h];
+		if ((unsigned char *)e - base == underflows[h])
+			newinfo->underflow[h] = underflows[h];
+	}
+
+	/* FIXME: underflows must be unconditional, standard verdicts
+	   < 0 (not ARPT_RETURN). --RR */
+
+	/* Clear counters and comefrom */
+	e->counters = ((struct xt_counters) { 0, 0 });
+	e->comefrom = 0;
+
+	(*i)++;
+	return 0;
+}
+
+static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
+{
+	struct xt_tgdtor_param par;
+	struct arpt_entry_target *t;
+
+	if (i && (*i)-- == 0)
+		return 1;
+
+	t = arpt_get_target(e);
+	par.target   = t->u.kernel.target;
+	par.targinfo = t->data;
+	par.family   = NFPROTO_ARP;
+	if (par.target->destroy != NULL)
+		par.target->destroy(&par);
+	module_put(par.target->me);
+	return 0;
+}
+
+/* Checks and translates the user-supplied table segment (held in
+ * newinfo).
+ */
+static int translate_table(const char *name,
+			   unsigned int valid_hooks,
+			   struct xt_table_info *newinfo,
+			   void *entry0,
+			   unsigned int size,
+			   unsigned int number,
+			   const unsigned int *hook_entries,
+			   const unsigned int *underflows)
+{
+	unsigned int i;
+	int ret;
+
+	newinfo->size = size;
+	newinfo->number = number;
+
+	/* Init all hooks to impossible value. */
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		newinfo->hook_entry[i] = 0xFFFFFFFF;
+		newinfo->underflow[i] = 0xFFFFFFFF;
+	}
+
+	duprintf("translate_table: size %u\n", newinfo->size);
+	i = 0;
+
+	/* Walk through entries, checking offsets. */
+	ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
+				 check_entry_size_and_hooks,
+				 newinfo,
+				 entry0,
+				 entry0 + size,
+				 hook_entries, underflows, &i);
+	duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
+	if (ret != 0)
+		return ret;
+
+	if (i != number) {
+		duprintf("translate_table: %u not %u entries\n",
+			 i, number);
+		return -EINVAL;
+	}
+
+	/* Check hooks all assigned */
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		/* Only hooks which are valid */
+		if (!(valid_hooks & (1 << i)))
+			continue;
+		if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
+			duprintf("Invalid hook entry %u %u\n",
+				 i, hook_entries[i]);
+			return -EINVAL;
+		}
+		if (newinfo->underflow[i] == 0xFFFFFFFF) {
+			duprintf("Invalid underflow %u %u\n",
+				 i, underflows[i]);
+			return -EINVAL;
+		}
+	}
+
+	if (!mark_source_chains(newinfo, valid_hooks, entry0)) {
+		duprintf("Looping hook\n");
+		return -ELOOP;
+	}
+
+	/* Finally, each sanity check must pass */
+	i = 0;
+	ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
+				 find_check_entry, name, size, &i);
+
+	if (ret != 0) {
+		ARPT_ENTRY_ITERATE(entry0, newinfo->size,
+				cleanup_entry, &i);
+		return ret;
+	}
+
+	/* And one copy for every other CPU */
+	for_each_possible_cpu(i) {
+		if (newinfo->entries[i] && newinfo->entries[i] != entry0)
+			memcpy(newinfo->entries[i], entry0, newinfo->size);
+	}
+
+	return ret;
+}
+
+/* Gets counters. */
+static inline int add_entry_to_counter(const struct arpt_entry *e,
+				       struct xt_counters total[],
+				       unsigned int *i)
+{
+	ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+
+	(*i)++;
+	return 0;
+}
+
+static inline int set_entry_to_counter(const struct arpt_entry *e,
+				       struct xt_counters total[],
+				       unsigned int *i)
+{
+	SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+
+	(*i)++;
+	return 0;
+}
+
+static void get_counters(const struct xt_table_info *t,
+			 struct xt_counters counters[])
+{
+	unsigned int cpu;
+	unsigned int i;
+	unsigned int curcpu;
+
+	/* Instead of clearing (by a previous call to memset())
+	 * the counters and using adds, we set the counters
+	 * with data used by 'current' CPU
+	 * We dont care about preemption here.
+	 */
+	curcpu = raw_smp_processor_id();
+
+	i = 0;
+	ARPT_ENTRY_ITERATE(t->entries[curcpu],
+			   t->size,
+			   set_entry_to_counter,
+			   counters,
+			   &i);
+
+	for_each_possible_cpu(cpu) {
+		if (cpu == curcpu)
+			continue;
+		i = 0;
+		ARPT_ENTRY_ITERATE(t->entries[cpu],
+				   t->size,
+				   add_entry_to_counter,
+				   counters,
+				   &i);
+	}
+}
+
+static inline struct xt_counters *alloc_counters(struct xt_table *table)
+{
+	unsigned int countersize;
+	struct xt_counters *counters;
+	const struct xt_table_info *private = table->private;
+
+	/* We need atomic snapshot of counters: rest doesn't change
+	 * (other than comefrom, which userspace doesn't care
+	 * about).
+	 */
+	countersize = sizeof(struct xt_counters) * private->number;
+	counters = vmalloc_node(countersize, numa_node_id());
+
+	if (counters == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	/* First, sum counters... */
+	write_lock_bh(&table->lock);
+	get_counters(private, counters);
+	write_unlock_bh(&table->lock);
+
+	return counters;
+}
+
+static int copy_entries_to_user(unsigned int total_size,
+				struct xt_table *table,
+				void __user *userptr)
+{
+	unsigned int off, num;
+	struct arpt_entry *e;
+	struct xt_counters *counters;
+	struct xt_table_info *private = table->private;
+	int ret = 0;
+	void *loc_cpu_entry;
+
+	counters = alloc_counters(table);
+	if (IS_ERR(counters))
+		return PTR_ERR(counters);
+
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	/* ... then copy entire thing ... */
+	if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
+		ret = -EFAULT;
+		goto free_counters;
+	}
+
+	/* FIXME: use iterator macros --RR */
+	/* ... then go back and fix counters and names */
+	for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
+		struct arpt_entry_target *t;
+
+		e = (struct arpt_entry *)(loc_cpu_entry + off);
+		if (copy_to_user(userptr + off
+				 + offsetof(struct arpt_entry, counters),
+				 &counters[num],
+				 sizeof(counters[num])) != 0) {
+			ret = -EFAULT;
+			goto free_counters;
+		}
+
+		t = arpt_get_target(e);
+		if (copy_to_user(userptr + off + e->target_offset
+				 + offsetof(struct arpt_entry_target,
+					    u.user.name),
+				 t->u.kernel.target->name,
+				 strlen(t->u.kernel.target->name)+1) != 0) {
+			ret = -EFAULT;
+			goto free_counters;
+		}
+	}
+
+ free_counters:
+	vfree(counters);
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static void compat_standard_from_user(void *dst, void *src)
+{
+	int v = *(compat_int_t *)src;
+
+	if (v > 0)
+		v += xt_compat_calc_jump(NFPROTO_ARP, v);
+	memcpy(dst, &v, sizeof(v));
+}
+
+static int compat_standard_to_user(void __user *dst, void *src)
+{
+	compat_int_t cv = *(int *)src;
+
+	if (cv > 0)
+		cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
+	return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
+}
+
+static int compat_calc_entry(struct arpt_entry *e,
+			     const struct xt_table_info *info,
+			     void *base, struct xt_table_info *newinfo)
+{
+	struct arpt_entry_target *t;
+	unsigned int entry_offset;
+	int off, i, ret;
+
+	off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+	entry_offset = (void *)e - base;
+
+	t = arpt_get_target(e);
+	off += xt_compat_target_offset(t->u.kernel.target);
+	newinfo->size -= off;
+	ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		if (info->hook_entry[i] &&
+		    (e < (struct arpt_entry *)(base + info->hook_entry[i])))
+			newinfo->hook_entry[i] -= off;
+		if (info->underflow[i] &&
+		    (e < (struct arpt_entry *)(base + info->underflow[i])))
+			newinfo->underflow[i] -= off;
+	}
+	return 0;
+}
+
+static int compat_table_info(const struct xt_table_info *info,
+			     struct xt_table_info *newinfo)
+{
+	void *loc_cpu_entry;
+
+	if (!newinfo || !info)
+		return -EINVAL;
+
+	/* we dont care about newinfo->entries[] */
+	memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
+	newinfo->initial_entries = 0;
+	loc_cpu_entry = info->entries[raw_smp_processor_id()];
+	return ARPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
+				  compat_calc_entry, info, loc_cpu_entry,
+				  newinfo);
+}
+#endif
+
+static int get_info(struct net *net, void __user *user, int *len, int compat)
+{
+	char name[ARPT_TABLE_MAXNAMELEN];
+	struct xt_table *t;
+	int ret;
+
+	if (*len != sizeof(struct arpt_getinfo)) {
+		duprintf("length %u != %Zu\n", *len,
+			 sizeof(struct arpt_getinfo));
+		return -EINVAL;
+	}
+
+	if (copy_from_user(name, user, sizeof(name)) != 0)
+		return -EFAULT;
+
+	name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
+#ifdef CONFIG_COMPAT
+	if (compat)
+		xt_compat_lock(NFPROTO_ARP);
+#endif
+	t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
+				    "arptable_%s", name);
+	if (t && !IS_ERR(t)) {
+		struct arpt_getinfo info;
+		const struct xt_table_info *private = t->private;
+
+#ifdef CONFIG_COMPAT
+		if (compat) {
+			struct xt_table_info tmp;
+			ret = compat_table_info(private, &tmp);
+			xt_compat_flush_offsets(NFPROTO_ARP);
+			private = &tmp;
+		}
+#endif
+		info.valid_hooks = t->valid_hooks;
+		memcpy(info.hook_entry, private->hook_entry,
+		       sizeof(info.hook_entry));
+		memcpy(info.underflow, private->underflow,
+		       sizeof(info.underflow));
+		info.num_entries = private->number;
+		info.size = private->size;
+		strcpy(info.name, name);
+
+		if (copy_to_user(user, &info, *len) != 0)
+			ret = -EFAULT;
+		else
+			ret = 0;
+		xt_table_unlock(t);
+		module_put(t->me);
+	} else
+		ret = t ? PTR_ERR(t) : -ENOENT;
+#ifdef CONFIG_COMPAT
+	if (compat)
+		xt_compat_unlock(NFPROTO_ARP);
+#endif
+	return ret;
+}
+
+static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
+		       int *len)
+{
+	int ret;
+	struct arpt_get_entries get;
+	struct xt_table *t;
+
+	if (*len < sizeof(get)) {
+		duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
+		return -EINVAL;
+	}
+	if (copy_from_user(&get, uptr, sizeof(get)) != 0)
+		return -EFAULT;
+	if (*len != sizeof(struct arpt_get_entries) + get.size) {
+		duprintf("get_entries: %u != %Zu\n", *len,
+			 sizeof(struct arpt_get_entries) + get.size);
+		return -EINVAL;
+	}
+
+	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
+	if (t && !IS_ERR(t)) {
+		const struct xt_table_info *private = t->private;
+
+		duprintf("t->private->number = %u\n",
+			 private->number);
+		if (get.size == private->size)
+			ret = copy_entries_to_user(private->size,
+						   t, uptr->entrytable);
+		else {
+			duprintf("get_entries: I've got %u not %u!\n",
+				 private->size, get.size);
+			ret = -EAGAIN;
+		}
+		module_put(t->me);
+		xt_table_unlock(t);
+	} else
+		ret = t ? PTR_ERR(t) : -ENOENT;
+
+	return ret;
+}
+
+static int __do_replace(struct net *net, const char *name,
+			unsigned int valid_hooks,
+			struct xt_table_info *newinfo,
+			unsigned int num_counters,
+			void __user *counters_ptr)
+{
+	int ret;
+	struct xt_table *t;
+	struct xt_table_info *oldinfo;
+	struct xt_counters *counters;
+	void *loc_cpu_old_entry;
+
+	ret = 0;
+	counters = vmalloc_node(num_counters * sizeof(struct xt_counters),
+				numa_node_id());
+	if (!counters) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
+				    "arptable_%s", name);
+	if (!t || IS_ERR(t)) {
+		ret = t ? PTR_ERR(t) : -ENOENT;
+		goto free_newinfo_counters_untrans;
+	}
+
+	/* You lied! */
+	if (valid_hooks != t->valid_hooks) {
+		duprintf("Valid hook crap: %08X vs %08X\n",
+			 valid_hooks, t->valid_hooks);
+		ret = -EINVAL;
+		goto put_module;
+	}
+
+	oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
+	if (!oldinfo)
+		goto put_module;
+
+	/* Update module usage count based on number of rules */
+	duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
+		oldinfo->number, oldinfo->initial_entries, newinfo->number);
+	if ((oldinfo->number > oldinfo->initial_entries) ||
+	    (newinfo->number <= oldinfo->initial_entries))
+		module_put(t->me);
+	if ((oldinfo->number > oldinfo->initial_entries) &&
+	    (newinfo->number <= oldinfo->initial_entries))
+		module_put(t->me);
+
+	/* Get the old counters. */
+	get_counters(oldinfo, counters);
+	/* Decrease module usage counts and free resource */
+	loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
+	ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
+			   NULL);
+
+	xt_free_table_info(oldinfo);
+	if (copy_to_user(counters_ptr, counters,
+			 sizeof(struct xt_counters) * num_counters) != 0)
+		ret = -EFAULT;
+	vfree(counters);
+	xt_table_unlock(t);
+	return ret;
+
+ put_module:
+	module_put(t->me);
+	xt_table_unlock(t);
+ free_newinfo_counters_untrans:
+	vfree(counters);
+ out:
+	return ret;
+}
+
+static int do_replace(struct net *net, void __user *user, unsigned int len)
+{
+	int ret;
+	struct arpt_replace tmp;
+	struct xt_table_info *newinfo;
+	void *loc_cpu_entry;
+
+	if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
+		return -EFAULT;
+
+	/* overflow check */
+	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
+		return -ENOMEM;
+
+	newinfo = xt_alloc_table_info(tmp.size);
+	if (!newinfo)
+		return -ENOMEM;
+
+	/* choose the copy that is on our node/cpu */
+	loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+	if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
+			   tmp.size) != 0) {
+		ret = -EFAULT;
+		goto free_newinfo;
+	}
+
+	ret = translate_table(tmp.name, tmp.valid_hooks,
+			      newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
+			      tmp.hook_entry, tmp.underflow);
+	if (ret != 0)
+		goto free_newinfo;
+
+	duprintf("arp_tables: Translated table\n");
+
+	ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
+			   tmp.num_counters, tmp.counters);
+	if (ret)
+		goto free_newinfo_untrans;
+	return 0;
+
+ free_newinfo_untrans:
+	ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
+ free_newinfo:
+	xt_free_table_info(newinfo);
+	return ret;
+}
+
+/* We're lazy, and add to the first CPU; overflow works its fey magic
+ * and everything is OK.
+ */
+static inline int add_counter_to_entry(struct arpt_entry *e,
+				       const struct xt_counters addme[],
+				       unsigned int *i)
+{
+
+	ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
+
+	(*i)++;
+	return 0;
+}
+
+static int do_add_counters(struct net *net, void __user *user, unsigned int len,
+			   int compat)
+{
+	unsigned int i;
+	struct xt_counters_info tmp;
+	struct xt_counters *paddc;
+	unsigned int num_counters;
+	const char *name;
+	int size;
+	void *ptmp;
+	struct xt_table *t;
+	const struct xt_table_info *private;
+	int ret = 0;
+	void *loc_cpu_entry;
+#ifdef CONFIG_COMPAT
+	struct compat_xt_counters_info compat_tmp;
+
+	if (compat) {
+		ptmp = &compat_tmp;
+		size = sizeof(struct compat_xt_counters_info);
+	} else
+#endif
+	{
+		ptmp = &tmp;
+		size = sizeof(struct xt_counters_info);
+	}
+
+	if (copy_from_user(ptmp, user, size) != 0)
+		return -EFAULT;
+
+#ifdef CONFIG_COMPAT
+	if (compat) {
+		num_counters = compat_tmp.num_counters;
+		name = compat_tmp.name;
+	} else
+#endif
+	{
+		num_counters = tmp.num_counters;
+		name = tmp.name;
+	}
+
+	if (len != size + num_counters * sizeof(struct xt_counters))
+		return -EINVAL;
+
+	paddc = vmalloc_node(len - size, numa_node_id());
+	if (!paddc)
+		return -ENOMEM;
+
+	if (copy_from_user(paddc, user + size, len - size) != 0) {
+		ret = -EFAULT;
+		goto free;
+	}
+
+	t = xt_find_table_lock(net, NFPROTO_ARP, name);
+	if (!t || IS_ERR(t)) {
+		ret = t ? PTR_ERR(t) : -ENOENT;
+		goto free;
+	}
+
+	write_lock_bh(&t->lock);
+	private = t->private;
+	if (private->number != num_counters) {
+		ret = -EINVAL;
+		goto unlock_up_free;
+	}
+
+	i = 0;
+	/* Choose the copy that is on our node */
+	loc_cpu_entry = private->entries[smp_processor_id()];
+	ARPT_ENTRY_ITERATE(loc_cpu_entry,
+			   private->size,
+			   add_counter_to_entry,
+			   paddc,
+			   &i);
+ unlock_up_free:
+	write_unlock_bh(&t->lock);
+	xt_table_unlock(t);
+	module_put(t->me);
+ free:
+	vfree(paddc);
+
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static inline int
+compat_release_entry(struct compat_arpt_entry *e, unsigned int *i)
+{
+	struct arpt_entry_target *t;
+
+	if (i && (*i)-- == 0)
+		return 1;
+
+	t = compat_arpt_get_target(e);
+	module_put(t->u.kernel.target->me);
+	return 0;
+}
+
+static inline int
+check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
+				  struct xt_table_info *newinfo,
+				  unsigned int *size,
+				  unsigned char *base,
+				  unsigned char *limit,
+				  unsigned int *hook_entries,
+				  unsigned int *underflows,
+				  unsigned int *i,
+				  const char *name)
+{
+	struct arpt_entry_target *t;
+	struct xt_target *target;
+	unsigned int entry_offset;
+	int ret, off, h;
+
+	duprintf("check_compat_entry_size_and_hooks %p\n", e);
+	if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0
+	    || (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
+		duprintf("Bad offset %p, limit = %p\n", e, limit);
+		return -EINVAL;
+	}
+
+	if (e->next_offset < sizeof(struct compat_arpt_entry) +
+			     sizeof(struct compat_xt_entry_target)) {
+		duprintf("checking: element %p size %u\n",
+			 e, e->next_offset);
+		return -EINVAL;
+	}
+
+	/* For purposes of check_entry casting the compat entry is fine */
+	ret = check_entry((struct arpt_entry *)e, name);
+	if (ret)
+		return ret;
+
+	off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+	entry_offset = (void *)e - (void *)base;
+
+	t = compat_arpt_get_target(e);
+	target = try_then_request_module(xt_find_target(NFPROTO_ARP,
+							t->u.user.name,
+							t->u.user.revision),
+					 "arpt_%s", t->u.user.name);
+	if (IS_ERR(target) || !target) {
+		duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
+			 t->u.user.name);
+		ret = target ? PTR_ERR(target) : -ENOENT;
+		goto out;
+	}
+	t->u.kernel.target = target;
+
+	off += xt_compat_target_offset(target);
+	*size += off;
+	ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
+	if (ret)
+		goto release_target;
+
+	/* Check hooks & underflows */
+	for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
+		if ((unsigned char *)e - base == hook_entries[h])
+			newinfo->hook_entry[h] = hook_entries[h];
+		if ((unsigned char *)e - base == underflows[h])
+			newinfo->underflow[h] = underflows[h];
+	}
+
+	/* Clear counters and comefrom */
+	memset(&e->counters, 0, sizeof(e->counters));
+	e->comefrom = 0;
+
+	(*i)++;
+	return 0;
+
+release_target:
+	module_put(t->u.kernel.target->me);
+out:
+	return ret;
+}
+
+static int
+compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
+			    unsigned int *size, const char *name,
+			    struct xt_table_info *newinfo, unsigned char *base)
+{
+	struct arpt_entry_target *t;
+	struct xt_target *target;
+	struct arpt_entry *de;
+	unsigned int origsize;
+	int ret, h;
+
+	ret = 0;
+	origsize = *size;
+	de = (struct arpt_entry *)*dstptr;
+	memcpy(de, e, sizeof(struct arpt_entry));
+	memcpy(&de->counters, &e->counters, sizeof(e->counters));
+
+	*dstptr += sizeof(struct arpt_entry);
+	*size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+
+	de->target_offset = e->target_offset - (origsize - *size);
+	t = compat_arpt_get_target(e);
+	target = t->u.kernel.target;
+	xt_compat_target_from_user(t, dstptr, size);
+
+	de->next_offset = e->next_offset - (origsize - *size);
+	for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
+		if ((unsigned char *)de - base < newinfo->hook_entry[h])
+			newinfo->hook_entry[h] -= origsize - *size;
+		if ((unsigned char *)de - base < newinfo->underflow[h])
+			newinfo->underflow[h] -= origsize - *size;
+	}
+	return ret;
+}
+
+static inline int compat_check_entry(struct arpt_entry *e, const char *name,
+				     unsigned int *i)
+{
+	int ret;
+
+	ret = check_target(e, name);
+	if (ret)
+		return ret;
+
+	(*i)++;
+	return 0;
+}
+
+static int translate_compat_table(const char *name,
+				  unsigned int valid_hooks,
+				  struct xt_table_info **pinfo,
+				  void **pentry0,
+				  unsigned int total_size,
+				  unsigned int number,
+				  unsigned int *hook_entries,
+				  unsigned int *underflows)
+{
+	unsigned int i, j;
+	struct xt_table_info *newinfo, *info;
+	void *pos, *entry0, *entry1;
+	unsigned int size;
+	int ret;
+
+	info = *pinfo;
+	entry0 = *pentry0;
+	size = total_size;
+	info->number = number;
+
+	/* Init all hooks to impossible value. */
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		info->hook_entry[i] = 0xFFFFFFFF;
+		info->underflow[i] = 0xFFFFFFFF;
+	}
+
+	duprintf("translate_compat_table: size %u\n", info->size);
+	j = 0;
+	xt_compat_lock(NFPROTO_ARP);
+	/* Walk through entries, checking offsets. */
+	ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
+					check_compat_entry_size_and_hooks,
+					info, &size, entry0,
+					entry0 + total_size,
+					hook_entries, underflows, &j, name);
+	if (ret != 0)
+		goto out_unlock;
+
+	ret = -EINVAL;
+	if (j != number) {
+		duprintf("translate_compat_table: %u not %u entries\n",
+			 j, number);
+		goto out_unlock;
+	}
+
+	/* Check hooks all assigned */
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		/* Only hooks which are valid */
+		if (!(valid_hooks & (1 << i)))
+			continue;
+		if (info->hook_entry[i] == 0xFFFFFFFF) {
+			duprintf("Invalid hook entry %u %u\n",
+				 i, hook_entries[i]);
+			goto out_unlock;
+		}
+		if (info->underflow[i] == 0xFFFFFFFF) {
+			duprintf("Invalid underflow %u %u\n",
+				 i, underflows[i]);
+			goto out_unlock;
+		}
+	}
+
+	ret = -ENOMEM;
+	newinfo = xt_alloc_table_info(size);
+	if (!newinfo)
+		goto out_unlock;
+
+	newinfo->number = number;
+	for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
+		newinfo->hook_entry[i] = info->hook_entry[i];
+		newinfo->underflow[i] = info->underflow[i];
+	}
+	entry1 = newinfo->entries[raw_smp_processor_id()];
+	pos = entry1;
+	size = total_size;
+	ret = COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size,
+					compat_copy_entry_from_user,
+					&pos, &size, name, newinfo, entry1);
+	xt_compat_flush_offsets(NFPROTO_ARP);
+	xt_compat_unlock(NFPROTO_ARP);
+	if (ret)
+		goto free_newinfo;
+
+	ret = -ELOOP;
+	if (!mark_source_chains(newinfo, valid_hooks, entry1))
+		goto free_newinfo;
+
+	i = 0;
+	ret = ARPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
+				 name, &i);
+	if (ret) {
+		j -= i;
+		COMPAT_ARPT_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
+						   compat_release_entry, &j);
+		ARPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
+		xt_free_table_info(newinfo);
+		return ret;
+	}
+
+	/* And one copy for every other CPU */
+	for_each_possible_cpu(i)
+		if (newinfo->entries[i] && newinfo->entries[i] != entry1)
+			memcpy(newinfo->entries[i], entry1, newinfo->size);
+
+	*pinfo = newinfo;
+	*pentry0 = entry1;
+	xt_free_table_info(info);
+	return 0;
+
+free_newinfo:
+	xt_free_table_info(newinfo);
+out:
+	COMPAT_ARPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
+	return ret;
+out_unlock:
+	xt_compat_flush_offsets(NFPROTO_ARP);
+	xt_compat_unlock(NFPROTO_ARP);
+	goto out;
+}
+
+struct compat_arpt_replace {
+	char				name[ARPT_TABLE_MAXNAMELEN];
+	u32				valid_hooks;
+	u32				num_entries;
+	u32				size;
+	u32				hook_entry[NF_ARP_NUMHOOKS];
+	u32				underflow[NF_ARP_NUMHOOKS];
+	u32				num_counters;
+	compat_uptr_t			counters;
+	struct compat_arpt_entry	entries[0];
+};
+
+static int compat_do_replace(struct net *net, void __user *user,
+			     unsigned int len)
+{
+	int ret;
+	struct compat_arpt_replace tmp;
+	struct xt_table_info *newinfo;
+	void *loc_cpu_entry;
+
+	if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
+		return -EFAULT;
+
+	/* overflow check */
+	if (tmp.size >= INT_MAX / num_possible_cpus())
+		return -ENOMEM;
+	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
+		return -ENOMEM;
+
+	newinfo = xt_alloc_table_info(tmp.size);
+	if (!newinfo)
+		return -ENOMEM;
+
+	/* choose the copy that is on our node/cpu */
+	loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+	if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
+		ret = -EFAULT;
+		goto free_newinfo;
+	}
+
+	ret = translate_compat_table(tmp.name, tmp.valid_hooks,
+				     &newinfo, &loc_cpu_entry, tmp.size,
+				     tmp.num_entries, tmp.hook_entry,
+				     tmp.underflow);
+	if (ret != 0)
+		goto free_newinfo;
+
+	duprintf("compat_do_replace: Translated table\n");
+
+	ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
+			   tmp.num_counters, compat_ptr(tmp.counters));
+	if (ret)
+		goto free_newinfo_untrans;
+	return 0;
+
+ free_newinfo_untrans:
+	ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
+ free_newinfo:
+	xt_free_table_info(newinfo);
+	return ret;
+}
+
+static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
+				  unsigned int len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case ARPT_SO_SET_REPLACE:
+		ret = compat_do_replace(sock_net(sk), user, len);
+		break;
+
+	case ARPT_SO_SET_ADD_COUNTERS:
+		ret = do_add_counters(sock_net(sk), user, len, 1);
+		break;
+
+	default:
+		duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
+				     compat_uint_t *size,
+				     struct xt_counters *counters,
+				     unsigned int *i)
+{
+	struct arpt_entry_target *t;
+	struct compat_arpt_entry __user *ce;
+	u_int16_t target_offset, next_offset;
+	compat_uint_t origsize;
+	int ret;
+
+	ret = -EFAULT;
+	origsize = *size;
+	ce = (struct compat_arpt_entry __user *)*dstptr;
+	if (copy_to_user(ce, e, sizeof(struct arpt_entry)))
+		goto out;
+
+	if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
+		goto out;
+
+	*dstptr += sizeof(struct compat_arpt_entry);
+	*size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
+
+	target_offset = e->target_offset - (origsize - *size);
+
+	t = arpt_get_target(e);
+	ret = xt_compat_target_to_user(t, dstptr, size);
+	if (ret)
+		goto out;
+	ret = -EFAULT;
+	next_offset = e->next_offset - (origsize - *size);
+	if (put_user(target_offset, &ce->target_offset))
+		goto out;
+	if (put_user(next_offset, &ce->next_offset))
+		goto out;
+
+	(*i)++;
+	return 0;
+out:
+	return ret;
+}
+
+static int compat_copy_entries_to_user(unsigned int total_size,
+				       struct xt_table *table,
+				       void __user *userptr)
+{
+	struct xt_counters *counters;
+	const struct xt_table_info *private = table->private;
+	void __user *pos;
+	unsigned int size;
+	int ret = 0;
+	void *loc_cpu_entry;
+	unsigned int i = 0;
+
+	counters = alloc_counters(table);
+	if (IS_ERR(counters))
+		return PTR_ERR(counters);
+
+	/* choose the copy on our node/cpu */
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	pos = userptr;
+	size = total_size;
+	ret = ARPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
+				 compat_copy_entry_to_user,
+				 &pos, &size, counters, &i);
+	vfree(counters);
+	return ret;
+}
+
+struct compat_arpt_get_entries {
+	char name[ARPT_TABLE_MAXNAMELEN];
+	compat_uint_t size;
+	struct compat_arpt_entry entrytable[0];
+};
+
+static int compat_get_entries(struct net *net,
+			      struct compat_arpt_get_entries __user *uptr,
+			      int *len)
+{
+	int ret;
+	struct compat_arpt_get_entries get;
+	struct xt_table *t;
+
+	if (*len < sizeof(get)) {
+		duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
+		return -EINVAL;
+	}
+	if (copy_from_user(&get, uptr, sizeof(get)) != 0)
+		return -EFAULT;
+	if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
+		duprintf("compat_get_entries: %u != %zu\n",
+			 *len, sizeof(get) + get.size);
+		return -EINVAL;
+	}
+
+	xt_compat_lock(NFPROTO_ARP);
+	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
+	if (t && !IS_ERR(t)) {
+		const struct xt_table_info *private = t->private;
+		struct xt_table_info info;
+
+		duprintf("t->private->number = %u\n", private->number);
+		ret = compat_table_info(private, &info);
+		if (!ret && get.size == info.size) {
+			ret = compat_copy_entries_to_user(private->size,
+							  t, uptr->entrytable);
+		} else if (!ret) {
+			duprintf("compat_get_entries: I've got %u not %u!\n",
+				 private->size, get.size);
+			ret = -EAGAIN;
+		}
+		xt_compat_flush_offsets(NFPROTO_ARP);
+		module_put(t->me);
+		xt_table_unlock(t);
+	} else
+		ret = t ? PTR_ERR(t) : -ENOENT;
+
+	xt_compat_unlock(NFPROTO_ARP);
+	return ret;
+}
+
+static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
+
+static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
+				  int *len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case ARPT_SO_GET_INFO:
+		ret = get_info(sock_net(sk), user, len, 1);
+		break;
+	case ARPT_SO_GET_ENTRIES:
+		ret = compat_get_entries(sock_net(sk), user, len);
+		break;
+	default:
+		ret = do_arpt_get_ctl(sk, cmd, user, len);
+	}
+	return ret;
+}
+#endif
+
+static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case ARPT_SO_SET_REPLACE:
+		ret = do_replace(sock_net(sk), user, len);
+		break;
+
+	case ARPT_SO_SET_ADD_COUNTERS:
+		ret = do_add_counters(sock_net(sk), user, len, 0);
+		break;
+
+	default:
+		duprintf("do_arpt_set_ctl:  unknown request %i\n", cmd);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case ARPT_SO_GET_INFO:
+		ret = get_info(sock_net(sk), user, len, 0);
+		break;
+
+	case ARPT_SO_GET_ENTRIES:
+		ret = get_entries(sock_net(sk), user, len);
+		break;
+
+	case ARPT_SO_GET_REVISION_TARGET: {
+		struct xt_get_revision rev;
+
+		if (*len != sizeof(rev)) {
+			ret = -EINVAL;
+			break;
+		}
+		if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
+			ret = -EFAULT;
+			break;
+		}
+
+		try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
+							 rev.revision, 1, &ret),
+					"arpt_%s", rev.name);
+		break;
+	}
+
+	default:
+		duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+struct xt_table *arpt_register_table(struct net *net, struct xt_table *table,
+				     const struct arpt_replace *repl)
+{
+	int ret;
+	struct xt_table_info *newinfo;
+	struct xt_table_info bootstrap
+		= { 0, 0, 0, { 0 }, { 0 }, { } };
+	void *loc_cpu_entry;
+	struct xt_table *new_table;
+
+	newinfo = xt_alloc_table_info(repl->size);
+	if (!newinfo) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* choose the copy on our node/cpu */
+	loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+	memcpy(loc_cpu_entry, repl->entries, repl->size);
+
+	ret = translate_table(table->name, table->valid_hooks,
+			      newinfo, loc_cpu_entry, repl->size,
+			      repl->num_entries,
+			      repl->hook_entry,
+			      repl->underflow);
+
+	duprintf("arpt_register_table: translate table gives %d\n", ret);
+	if (ret != 0)
+		goto out_free;
+
+	new_table = xt_register_table(net, table, &bootstrap, newinfo);
+	if (IS_ERR(new_table)) {
+		ret = PTR_ERR(new_table);
+		goto out_free;
+	}
+	return new_table;
+
+out_free:
+	xt_free_table_info(newinfo);
+out:
+	return ERR_PTR(ret);
+}
+
+void arpt_unregister_table(struct xt_table *table)
+{
+	struct xt_table_info *private;
+	void *loc_cpu_entry;
+	struct module *table_owner = table->me;
+
+	private = xt_unregister_table(table);
+
+	/* Decrease module usage counts and free resources */
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
+			   cleanup_entry, NULL);
+	if (private->number > private->initial_entries)
+		module_put(table_owner);
+	xt_free_table_info(private);
+}
+
+/* The built-in targets: standard (NULL) and error. */
+static struct xt_target arpt_standard_target __read_mostly = {
+	.name		= ARPT_STANDARD_TARGET,
+	.targetsize	= sizeof(int),
+	.family		= NFPROTO_ARP,
+#ifdef CONFIG_COMPAT
+	.compatsize	= sizeof(compat_int_t),
+	.compat_from_user = compat_standard_from_user,
+	.compat_to_user	= compat_standard_to_user,
+#endif
+};
+
+static struct xt_target arpt_error_target __read_mostly = {
+	.name		= ARPT_ERROR_TARGET,
+	.target		= arpt_error,
+	.targetsize	= ARPT_FUNCTION_MAXNAMELEN,
+	.family		= NFPROTO_ARP,
+};
+
+static struct nf_sockopt_ops arpt_sockopts = {
+	.pf		= PF_INET,
+	.set_optmin	= ARPT_BASE_CTL,
+	.set_optmax	= ARPT_SO_SET_MAX+1,
+	.set		= do_arpt_set_ctl,
+#ifdef CONFIG_COMPAT
+	.compat_set	= compat_do_arpt_set_ctl,
+#endif
+	.get_optmin	= ARPT_BASE_CTL,
+	.get_optmax	= ARPT_SO_GET_MAX+1,
+	.get		= do_arpt_get_ctl,
+#ifdef CONFIG_COMPAT
+	.compat_get	= compat_do_arpt_get_ctl,
+#endif
+	.owner		= THIS_MODULE,
+};
+
+static int __net_init arp_tables_net_init(struct net *net)
+{
+	return xt_proto_init(net, NFPROTO_ARP);
+}
+
+static void __net_exit arp_tables_net_exit(struct net *net)
+{
+	xt_proto_fini(net, NFPROTO_ARP);
+}
+
+static struct pernet_operations arp_tables_net_ops = {
+	.init = arp_tables_net_init,
+	.exit = arp_tables_net_exit,
+};
+
+static int __init arp_tables_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&arp_tables_net_ops);
+	if (ret < 0)
+		goto err1;
+
+	/* Noone else will be downing sem now, so we won't sleep */
+	ret = xt_register_target(&arpt_standard_target);
+	if (ret < 0)
+		goto err2;
+	ret = xt_register_target(&arpt_error_target);
+	if (ret < 0)
+		goto err3;
+
+	/* Register setsockopt */
+	ret = nf_register_sockopt(&arpt_sockopts);
+	if (ret < 0)
+		goto err4;
+
+	printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
+	return 0;
+
+err4:
+	xt_unregister_target(&arpt_error_target);
+err3:
+	xt_unregister_target(&arpt_standard_target);
+err2:
+	unregister_pernet_subsys(&arp_tables_net_ops);
+err1:
+	return ret;
+}
+
+static void __exit arp_tables_fini(void)
+{
+	nf_unregister_sockopt(&arpt_sockopts);
+	xt_unregister_target(&arpt_error_target);
+	xt_unregister_target(&arpt_standard_target);
+	unregister_pernet_subsys(&arp_tables_net_ops);
+}
+
+EXPORT_SYMBOL(arpt_register_table);
+EXPORT_SYMBOL(arpt_unregister_table);
+EXPORT_SYMBOL(arpt_do_table);
+
+module_init(arp_tables_init);
+module_exit(arp_tables_fini);
diff --git a/net/ipv4/netfilter/arpt_mangle.c b/net/ipv4/netfilter/arpt_mangle.c
new file mode 100644
index 0000000..b0d5b1d
--- /dev/null
+++ b/net/ipv4/netfilter/arpt_mangle.c
@@ -0,0 +1,91 @@
+/* module that allows mangling of the arp payload */
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_arp/arpt_mangle.h>
+#include <net/sock.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
+MODULE_DESCRIPTION("arptables arp payload mangle target");
+
+static unsigned int
+target(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	const struct arpt_mangle *mangle = par->targinfo;
+	const struct arphdr *arp;
+	unsigned char *arpptr;
+	int pln, hln;
+
+	if (!skb_make_writable(skb, skb->len))
+		return NF_DROP;
+
+	arp = arp_hdr(skb);
+	arpptr = skb_network_header(skb) + sizeof(*arp);
+	pln = arp->ar_pln;
+	hln = arp->ar_hln;
+	/* We assume that pln and hln were checked in the match */
+	if (mangle->flags & ARPT_MANGLE_SDEV) {
+		if (ARPT_DEV_ADDR_LEN_MAX < hln ||
+		   (arpptr + hln > skb_tail_pointer(skb)))
+			return NF_DROP;
+		memcpy(arpptr, mangle->src_devaddr, hln);
+	}
+	arpptr += hln;
+	if (mangle->flags & ARPT_MANGLE_SIP) {
+		if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
+		   (arpptr + pln > skb_tail_pointer(skb)))
+			return NF_DROP;
+		memcpy(arpptr, &mangle->u_s.src_ip, pln);
+	}
+	arpptr += pln;
+	if (mangle->flags & ARPT_MANGLE_TDEV) {
+		if (ARPT_DEV_ADDR_LEN_MAX < hln ||
+		   (arpptr + hln > skb_tail_pointer(skb)))
+			return NF_DROP;
+		memcpy(arpptr, mangle->tgt_devaddr, hln);
+	}
+	arpptr += hln;
+	if (mangle->flags & ARPT_MANGLE_TIP) {
+		if (ARPT_MANGLE_ADDR_LEN_MAX < pln ||
+		   (arpptr + pln > skb_tail_pointer(skb)))
+			return NF_DROP;
+		memcpy(arpptr, &mangle->u_t.tgt_ip, pln);
+	}
+	return mangle->target;
+}
+
+static bool checkentry(const struct xt_tgchk_param *par)
+{
+	const struct arpt_mangle *mangle = par->targinfo;
+
+	if (mangle->flags & ~ARPT_MANGLE_MASK ||
+	    !(mangle->flags & ARPT_MANGLE_MASK))
+		return false;
+
+	if (mangle->target != NF_DROP && mangle->target != NF_ACCEPT &&
+	   mangle->target != ARPT_CONTINUE)
+		return false;
+	return true;
+}
+
+static struct xt_target arpt_mangle_reg __read_mostly = {
+	.name		= "mangle",
+	.family		= NFPROTO_ARP,
+	.target		= target,
+	.targetsize	= sizeof(struct arpt_mangle),
+	.checkentry	= checkentry,
+	.me		= THIS_MODULE,
+};
+
+static int __init arpt_mangle_init(void)
+{
+	return xt_register_target(&arpt_mangle_reg);
+}
+
+static void __exit arpt_mangle_fini(void)
+{
+	xt_unregister_target(&arpt_mangle_reg);
+}
+
+module_init(arpt_mangle_init);
+module_exit(arpt_mangle_fini);
diff --git a/net/ipv4/netfilter/arptable_filter.c b/net/ipv4/netfilter/arptable_filter.c
new file mode 100644
index 0000000..bee3d11
--- /dev/null
+++ b/net/ipv4/netfilter/arptable_filter.c
@@ -0,0 +1,157 @@
+/*
+ * Filtering ARP tables module.
+ *
+ * Copyright (C) 2002 David S. Miller (davem@redhat.com)
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter_arp/arp_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
+MODULE_DESCRIPTION("arptables filter table");
+
+#define FILTER_VALID_HOOKS ((1 << NF_ARP_IN) | (1 << NF_ARP_OUT) | \
+			   (1 << NF_ARP_FORWARD))
+
+static struct
+{
+	struct arpt_replace repl;
+	struct arpt_standard entries[3];
+	struct arpt_error term;
+} initial_table __net_initdata = {
+	.repl = {
+		.name = "filter",
+		.valid_hooks = FILTER_VALID_HOOKS,
+		.num_entries = 4,
+		.size = sizeof(struct arpt_standard) * 3 + sizeof(struct arpt_error),
+		.hook_entry = {
+			[NF_ARP_IN] = 0,
+			[NF_ARP_OUT] = sizeof(struct arpt_standard),
+			[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard),
+		},
+		.underflow = {
+			[NF_ARP_IN] = 0,
+			[NF_ARP_OUT] = sizeof(struct arpt_standard),
+			[NF_ARP_FORWARD] = 2 * sizeof(struct arpt_standard),
+		},
+	},
+	.entries = {
+		ARPT_STANDARD_INIT(NF_ACCEPT),	/* ARP_IN */
+		ARPT_STANDARD_INIT(NF_ACCEPT),	/* ARP_OUT */
+		ARPT_STANDARD_INIT(NF_ACCEPT),	/* ARP_FORWARD */
+	},
+	.term = ARPT_ERROR_INIT,
+};
+
+static struct xt_table packet_filter = {
+	.name		= "filter",
+	.valid_hooks	= FILTER_VALID_HOOKS,
+	.lock		= __RW_LOCK_UNLOCKED(packet_filter.lock),
+	.private	= NULL,
+	.me		= THIS_MODULE,
+	.af		= NFPROTO_ARP,
+};
+
+/* The work comes in here from netfilter.c */
+static unsigned int arpt_in_hook(unsigned int hook,
+				 struct sk_buff *skb,
+				 const struct net_device *in,
+				 const struct net_device *out,
+				 int (*okfn)(struct sk_buff *))
+{
+	return arpt_do_table(skb, hook, in, out,
+			     dev_net(in)->ipv4.arptable_filter);
+}
+
+static unsigned int arpt_out_hook(unsigned int hook,
+				  struct sk_buff *skb,
+				  const struct net_device *in,
+				  const struct net_device *out,
+				  int (*okfn)(struct sk_buff *))
+{
+	return arpt_do_table(skb, hook, in, out,
+			     dev_net(out)->ipv4.arptable_filter);
+}
+
+static unsigned int arpt_forward_hook(unsigned int hook,
+				      struct sk_buff *skb,
+				      const struct net_device *in,
+				      const struct net_device *out,
+				      int (*okfn)(struct sk_buff *))
+{
+	return arpt_do_table(skb, hook, in, out,
+			     dev_net(in)->ipv4.arptable_filter);
+}
+
+static struct nf_hook_ops arpt_ops[] __read_mostly = {
+	{
+		.hook		= arpt_in_hook,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_ARP,
+		.hooknum	= NF_ARP_IN,
+		.priority	= NF_IP_PRI_FILTER,
+	},
+	{
+		.hook		= arpt_out_hook,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_ARP,
+		.hooknum	= NF_ARP_OUT,
+		.priority	= NF_IP_PRI_FILTER,
+	},
+	{
+		.hook		= arpt_forward_hook,
+		.owner		= THIS_MODULE,
+		.pf		= NFPROTO_ARP,
+		.hooknum	= NF_ARP_FORWARD,
+		.priority	= NF_IP_PRI_FILTER,
+	},
+};
+
+static int __net_init arptable_filter_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.arptable_filter =
+		arpt_register_table(net, &packet_filter, &initial_table.repl);
+	if (IS_ERR(net->ipv4.arptable_filter))
+		return PTR_ERR(net->ipv4.arptable_filter);
+	return 0;
+}
+
+static void __net_exit arptable_filter_net_exit(struct net *net)
+{
+	arpt_unregister_table(net->ipv4.arptable_filter);
+}
+
+static struct pernet_operations arptable_filter_net_ops = {
+	.init = arptable_filter_net_init,
+	.exit = arptable_filter_net_exit,
+};
+
+static int __init arptable_filter_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&arptable_filter_net_ops);
+	if (ret < 0)
+		return ret;
+
+	ret = nf_register_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
+	if (ret < 0)
+		goto cleanup_table;
+	return ret;
+
+cleanup_table:
+	unregister_pernet_subsys(&arptable_filter_net_ops);
+	return ret;
+}
+
+static void __exit arptable_filter_fini(void)
+{
+	nf_unregister_hooks(arpt_ops, ARRAY_SIZE(arpt_ops));
+	unregister_pernet_subsys(&arptable_filter_net_ops);
+}
+
+module_init(arptable_filter_init);
+module_exit(arptable_filter_fini);
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
new file mode 100644
index 0000000..432ce9d
--- /dev/null
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -0,0 +1,645 @@
+/*
+ * This is a module which is used for queueing IPv4 packets and
+ * communicating with userspace via netlink.
+ *
+ * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
+ * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/notifier.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4/ip_queue.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netlink.h>
+#include <linux/spinlock.h>
+#include <linux/sysctl.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/security.h>
+#include <linux/mutex.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/route.h>
+#include <net/netfilter/nf_queue.h>
+#include <net/ip.h>
+
+#define IPQ_QMAX_DEFAULT 1024
+#define IPQ_PROC_FS_NAME "ip_queue"
+#define NET_IPQ_QMAX 2088
+#define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
+
+typedef int (*ipq_cmpfn)(struct nf_queue_entry *, unsigned long);
+
+static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
+static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
+static DEFINE_RWLOCK(queue_lock);
+static int peer_pid __read_mostly;
+static unsigned int copy_range __read_mostly;
+static unsigned int queue_total;
+static unsigned int queue_dropped = 0;
+static unsigned int queue_user_dropped = 0;
+static struct sock *ipqnl __read_mostly;
+static LIST_HEAD(queue_list);
+static DEFINE_MUTEX(ipqnl_mutex);
+
+static inline void
+__ipq_enqueue_entry(struct nf_queue_entry *entry)
+{
+       list_add_tail(&entry->list, &queue_list);
+       queue_total++;
+}
+
+static inline int
+__ipq_set_mode(unsigned char mode, unsigned int range)
+{
+	int status = 0;
+
+	switch(mode) {
+	case IPQ_COPY_NONE:
+	case IPQ_COPY_META:
+		copy_mode = mode;
+		copy_range = 0;
+		break;
+
+	case IPQ_COPY_PACKET:
+		copy_mode = mode;
+		copy_range = range;
+		if (copy_range > 0xFFFF)
+			copy_range = 0xFFFF;
+		break;
+
+	default:
+		status = -EINVAL;
+
+	}
+	return status;
+}
+
+static void __ipq_flush(ipq_cmpfn cmpfn, unsigned long data);
+
+static inline void
+__ipq_reset(void)
+{
+	peer_pid = 0;
+	net_disable_timestamp();
+	__ipq_set_mode(IPQ_COPY_NONE, 0);
+	__ipq_flush(NULL, 0);
+}
+
+static struct nf_queue_entry *
+ipq_find_dequeue_entry(unsigned long id)
+{
+	struct nf_queue_entry *entry = NULL, *i;
+
+	write_lock_bh(&queue_lock);
+
+	list_for_each_entry(i, &queue_list, list) {
+		if ((unsigned long)i == id) {
+			entry = i;
+			break;
+		}
+	}
+
+	if (entry) {
+		list_del(&entry->list);
+		queue_total--;
+	}
+
+	write_unlock_bh(&queue_lock);
+	return entry;
+}
+
+static void
+__ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
+{
+	struct nf_queue_entry *entry, *next;
+
+	list_for_each_entry_safe(entry, next, &queue_list, list) {
+		if (!cmpfn || cmpfn(entry, data)) {
+			list_del(&entry->list);
+			queue_total--;
+			nf_reinject(entry, NF_DROP);
+		}
+	}
+}
+
+static void
+ipq_flush(ipq_cmpfn cmpfn, unsigned long data)
+{
+	write_lock_bh(&queue_lock);
+	__ipq_flush(cmpfn, data);
+	write_unlock_bh(&queue_lock);
+}
+
+static struct sk_buff *
+ipq_build_packet_message(struct nf_queue_entry *entry, int *errp)
+{
+	sk_buff_data_t old_tail;
+	size_t size = 0;
+	size_t data_len = 0;
+	struct sk_buff *skb;
+	struct ipq_packet_msg *pmsg;
+	struct nlmsghdr *nlh;
+	struct timeval tv;
+
+	read_lock_bh(&queue_lock);
+
+	switch (copy_mode) {
+	case IPQ_COPY_META:
+	case IPQ_COPY_NONE:
+		size = NLMSG_SPACE(sizeof(*pmsg));
+		break;
+
+	case IPQ_COPY_PACKET:
+		if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
+		     entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    (*errp = skb_checksum_help(entry->skb))) {
+			read_unlock_bh(&queue_lock);
+			return NULL;
+		}
+		if (copy_range == 0 || copy_range > entry->skb->len)
+			data_len = entry->skb->len;
+		else
+			data_len = copy_range;
+
+		size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
+		break;
+
+	default:
+		*errp = -EINVAL;
+		read_unlock_bh(&queue_lock);
+		return NULL;
+	}
+
+	read_unlock_bh(&queue_lock);
+
+	skb = alloc_skb(size, GFP_ATOMIC);
+	if (!skb)
+		goto nlmsg_failure;
+
+	old_tail = skb->tail;
+	nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
+	pmsg = NLMSG_DATA(nlh);
+	memset(pmsg, 0, sizeof(*pmsg));
+
+	pmsg->packet_id       = (unsigned long )entry;
+	pmsg->data_len        = data_len;
+	tv = ktime_to_timeval(entry->skb->tstamp);
+	pmsg->timestamp_sec   = tv.tv_sec;
+	pmsg->timestamp_usec  = tv.tv_usec;
+	pmsg->mark            = entry->skb->mark;
+	pmsg->hook            = entry->hook;
+	pmsg->hw_protocol     = entry->skb->protocol;
+
+	if (entry->indev)
+		strcpy(pmsg->indev_name, entry->indev->name);
+	else
+		pmsg->indev_name[0] = '\0';
+
+	if (entry->outdev)
+		strcpy(pmsg->outdev_name, entry->outdev->name);
+	else
+		pmsg->outdev_name[0] = '\0';
+
+	if (entry->indev && entry->skb->dev) {
+		pmsg->hw_type = entry->skb->dev->type;
+		pmsg->hw_addrlen = dev_parse_header(entry->skb,
+						    pmsg->hw_addr);
+	}
+
+	if (data_len)
+		if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
+			BUG();
+
+	nlh->nlmsg_len = skb->tail - old_tail;
+	return skb;
+
+nlmsg_failure:
+	*errp = -EINVAL;
+	printk(KERN_ERR "ip_queue: error creating packet message\n");
+	return NULL;
+}
+
+static int
+ipq_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
+{
+	int status = -EINVAL;
+	struct sk_buff *nskb;
+
+	if (copy_mode == IPQ_COPY_NONE)
+		return -EAGAIN;
+
+	nskb = ipq_build_packet_message(entry, &status);
+	if (nskb == NULL)
+		return status;
+
+	write_lock_bh(&queue_lock);
+
+	if (!peer_pid)
+		goto err_out_free_nskb;
+
+	if (queue_total >= queue_maxlen) {
+		queue_dropped++;
+		status = -ENOSPC;
+		if (net_ratelimit())
+			  printk (KERN_WARNING "ip_queue: full at %d entries, "
+				  "dropping packets(s). Dropped: %d\n", queue_total,
+				  queue_dropped);
+		goto err_out_free_nskb;
+	}
+
+	/* netlink_unicast will either free the nskb or attach it to a socket */
+	status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
+	if (status < 0) {
+		queue_user_dropped++;
+		goto err_out_unlock;
+	}
+
+	__ipq_enqueue_entry(entry);
+
+	write_unlock_bh(&queue_lock);
+	return status;
+
+err_out_free_nskb:
+	kfree_skb(nskb);
+
+err_out_unlock:
+	write_unlock_bh(&queue_lock);
+	return status;
+}
+
+static int
+ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct nf_queue_entry *e)
+{
+	int diff;
+	struct iphdr *user_iph = (struct iphdr *)v->payload;
+	struct sk_buff *nskb;
+
+	if (v->data_len < sizeof(*user_iph))
+		return 0;
+	diff = v->data_len - e->skb->len;
+	if (diff < 0) {
+		if (pskb_trim(e->skb, v->data_len))
+			return -ENOMEM;
+	} else if (diff > 0) {
+		if (v->data_len > 0xFFFF)
+			return -EINVAL;
+		if (diff > skb_tailroom(e->skb)) {
+			nskb = skb_copy_expand(e->skb, skb_headroom(e->skb),
+					       diff, GFP_ATOMIC);
+			if (!nskb) {
+				printk(KERN_WARNING "ip_queue: error "
+				      "in mangle, dropping packet\n");
+				return -ENOMEM;
+			}
+			kfree_skb(e->skb);
+			e->skb = nskb;
+		}
+		skb_put(e->skb, diff);
+	}
+	if (!skb_make_writable(e->skb, v->data_len))
+		return -ENOMEM;
+	skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
+	e->skb->ip_summed = CHECKSUM_NONE;
+
+	return 0;
+}
+
+static int
+ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
+{
+	struct nf_queue_entry *entry;
+
+	if (vmsg->value > NF_MAX_VERDICT)
+		return -EINVAL;
+
+	entry = ipq_find_dequeue_entry(vmsg->id);
+	if (entry == NULL)
+		return -ENOENT;
+	else {
+		int verdict = vmsg->value;
+
+		if (vmsg->data_len && vmsg->data_len == len)
+			if (ipq_mangle_ipv4(vmsg, entry) < 0)
+				verdict = NF_DROP;
+
+		nf_reinject(entry, verdict);
+		return 0;
+	}
+}
+
+static int
+ipq_set_mode(unsigned char mode, unsigned int range)
+{
+	int status;
+
+	write_lock_bh(&queue_lock);
+	status = __ipq_set_mode(mode, range);
+	write_unlock_bh(&queue_lock);
+	return status;
+}
+
+static int
+ipq_receive_peer(struct ipq_peer_msg *pmsg,
+		 unsigned char type, unsigned int len)
+{
+	int status = 0;
+
+	if (len < sizeof(*pmsg))
+		return -EINVAL;
+
+	switch (type) {
+	case IPQM_MODE:
+		status = ipq_set_mode(pmsg->msg.mode.value,
+				      pmsg->msg.mode.range);
+		break;
+
+	case IPQM_VERDICT:
+		if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
+			status = -EINVAL;
+		else
+			status = ipq_set_verdict(&pmsg->msg.verdict,
+						 len - sizeof(*pmsg));
+			break;
+	default:
+		status = -EINVAL;
+	}
+	return status;
+}
+
+static int
+dev_cmp(struct nf_queue_entry *entry, unsigned long ifindex)
+{
+	if (entry->indev)
+		if (entry->indev->ifindex == ifindex)
+			return 1;
+	if (entry->outdev)
+		if (entry->outdev->ifindex == ifindex)
+			return 1;
+#ifdef CONFIG_BRIDGE_NETFILTER
+	if (entry->skb->nf_bridge) {
+		if (entry->skb->nf_bridge->physindev &&
+		    entry->skb->nf_bridge->physindev->ifindex == ifindex)
+			return 1;
+		if (entry->skb->nf_bridge->physoutdev &&
+		    entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
+			return 1;
+	}
+#endif
+	return 0;
+}
+
+static void
+ipq_dev_drop(int ifindex)
+{
+	ipq_flush(dev_cmp, ifindex);
+}
+
+#define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
+
+static inline void
+__ipq_rcv_skb(struct sk_buff *skb)
+{
+	int status, type, pid, flags, nlmsglen, skblen;
+	struct nlmsghdr *nlh;
+
+	skblen = skb->len;
+	if (skblen < sizeof(*nlh))
+		return;
+
+	nlh = nlmsg_hdr(skb);
+	nlmsglen = nlh->nlmsg_len;
+	if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
+		return;
+
+	pid = nlh->nlmsg_pid;
+	flags = nlh->nlmsg_flags;
+
+	if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
+		RCV_SKB_FAIL(-EINVAL);
+
+	if (flags & MSG_TRUNC)
+		RCV_SKB_FAIL(-ECOMM);
+
+	type = nlh->nlmsg_type;
+	if (type < NLMSG_NOOP || type >= IPQM_MAX)
+		RCV_SKB_FAIL(-EINVAL);
+
+	if (type <= IPQM_BASE)
+		return;
+
+	if (security_netlink_recv(skb, CAP_NET_ADMIN))
+		RCV_SKB_FAIL(-EPERM);
+
+	write_lock_bh(&queue_lock);
+
+	if (peer_pid) {
+		if (peer_pid != pid) {
+			write_unlock_bh(&queue_lock);
+			RCV_SKB_FAIL(-EBUSY);
+		}
+	} else {
+		net_enable_timestamp();
+		peer_pid = pid;
+	}
+
+	write_unlock_bh(&queue_lock);
+
+	status = ipq_receive_peer(NLMSG_DATA(nlh), type,
+				  nlmsglen - NLMSG_LENGTH(0));
+	if (status < 0)
+		RCV_SKB_FAIL(status);
+
+	if (flags & NLM_F_ACK)
+		netlink_ack(skb, nlh, 0);
+	return;
+}
+
+static void
+ipq_rcv_skb(struct sk_buff *skb)
+{
+	mutex_lock(&ipqnl_mutex);
+	__ipq_rcv_skb(skb);
+	mutex_unlock(&ipqnl_mutex);
+}
+
+static int
+ipq_rcv_dev_event(struct notifier_block *this,
+		  unsigned long event, void *ptr)
+{
+	struct net_device *dev = ptr;
+
+	if (!net_eq(dev_net(dev), &init_net))
+		return NOTIFY_DONE;
+
+	/* Drop any packets associated with the downed device */
+	if (event == NETDEV_DOWN)
+		ipq_dev_drop(dev->ifindex);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block ipq_dev_notifier = {
+	.notifier_call	= ipq_rcv_dev_event,
+};
+
+static int
+ipq_rcv_nl_event(struct notifier_block *this,
+		 unsigned long event, void *ptr)
+{
+	struct netlink_notify *n = ptr;
+
+	if (event == NETLINK_URELEASE &&
+	    n->protocol == NETLINK_FIREWALL && n->pid) {
+		write_lock_bh(&queue_lock);
+		if ((n->net == &init_net) && (n->pid == peer_pid))
+			__ipq_reset();
+		write_unlock_bh(&queue_lock);
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block ipq_nl_notifier = {
+	.notifier_call	= ipq_rcv_nl_event,
+};
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table_header *ipq_sysctl_header;
+
+static ctl_table ipq_table[] = {
+	{
+		.ctl_name	= NET_IPQ_QMAX,
+		.procname	= NET_IPQ_QMAX_NAME,
+		.data		= &queue_maxlen,
+		.maxlen		= sizeof(queue_maxlen),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
+	{ .ctl_name = 0 }
+};
+#endif
+
+#ifdef CONFIG_PROC_FS
+static int ip_queue_show(struct seq_file *m, void *v)
+{
+	read_lock_bh(&queue_lock);
+
+	seq_printf(m,
+		      "Peer PID          : %d\n"
+		      "Copy mode         : %hu\n"
+		      "Copy range        : %u\n"
+		      "Queue length      : %u\n"
+		      "Queue max. length : %u\n"
+		      "Queue dropped     : %u\n"
+		      "Netlink dropped   : %u\n",
+		      peer_pid,
+		      copy_mode,
+		      copy_range,
+		      queue_total,
+		      queue_maxlen,
+		      queue_dropped,
+		      queue_user_dropped);
+
+	read_unlock_bh(&queue_lock);
+	return 0;
+}
+
+static int ip_queue_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ip_queue_show, NULL);
+}
+
+static const struct file_operations ip_queue_proc_fops = {
+	.open		= ip_queue_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.owner		= THIS_MODULE,
+};
+#endif
+
+static const struct nf_queue_handler nfqh = {
+	.name	= "ip_queue",
+	.outfn	= &ipq_enqueue_packet,
+};
+
+static int __init ip_queue_init(void)
+{
+	int status = -ENOMEM;
+	struct proc_dir_entry *proc __maybe_unused;
+
+	netlink_register_notifier(&ipq_nl_notifier);
+	ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
+				      ipq_rcv_skb, NULL, THIS_MODULE);
+	if (ipqnl == NULL) {
+		printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
+		goto cleanup_netlink_notifier;
+	}
+
+#ifdef CONFIG_PROC_FS
+	proc = proc_create(IPQ_PROC_FS_NAME, 0, init_net.proc_net,
+			   &ip_queue_proc_fops);
+	if (!proc) {
+		printk(KERN_ERR "ip_queue: failed to create proc entry\n");
+		goto cleanup_ipqnl;
+	}
+#endif
+	register_netdevice_notifier(&ipq_dev_notifier);
+#ifdef CONFIG_SYSCTL
+	ipq_sysctl_header = register_sysctl_paths(net_ipv4_ctl_path, ipq_table);
+#endif
+	status = nf_register_queue_handler(PF_INET, &nfqh);
+	if (status < 0) {
+		printk(KERN_ERR "ip_queue: failed to register queue handler\n");
+		goto cleanup_sysctl;
+	}
+	return status;
+
+cleanup_sysctl:
+#ifdef CONFIG_SYSCTL
+	unregister_sysctl_table(ipq_sysctl_header);
+#endif
+	unregister_netdevice_notifier(&ipq_dev_notifier);
+	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
+cleanup_ipqnl: __maybe_unused
+	netlink_kernel_release(ipqnl);
+	mutex_lock(&ipqnl_mutex);
+	mutex_unlock(&ipqnl_mutex);
+
+cleanup_netlink_notifier:
+	netlink_unregister_notifier(&ipq_nl_notifier);
+	return status;
+}
+
+static void __exit ip_queue_fini(void)
+{
+	nf_unregister_queue_handlers(&nfqh);
+	synchronize_net();
+	ipq_flush(NULL, 0);
+
+#ifdef CONFIG_SYSCTL
+	unregister_sysctl_table(ipq_sysctl_header);
+#endif
+	unregister_netdevice_notifier(&ipq_dev_notifier);
+	proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
+
+	netlink_kernel_release(ipqnl);
+	mutex_lock(&ipqnl_mutex);
+	mutex_unlock(&ipqnl_mutex);
+
+	netlink_unregister_notifier(&ipq_nl_notifier);
+}
+
+MODULE_DESCRIPTION("IPv4 packet queue handler");
+MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
+MODULE_LICENSE("GPL");
+
+module_init(ip_queue_init);
+module_exit(ip_queue_fini);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
new file mode 100644
index 0000000..213fb27
--- /dev/null
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -0,0 +1,2285 @@
+/*
+ * Packet matching code.
+ *
+ * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/cache.h>
+#include <linux/capability.h>
+#include <linux/skbuff.h>
+#include <linux/kmod.h>
+#include <linux/vmalloc.h>
+#include <linux/netdevice.h>
+#include <linux/module.h>
+#include <linux/icmp.h>
+#include <net/ip.h>
+#include <net/compat.h>
+#include <asm/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/err.h>
+#include <linux/cpumask.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/netfilter/nf_log.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("IPv4 packet filter");
+
+/*#define DEBUG_IP_FIREWALL*/
+/*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
+/*#define DEBUG_IP_FIREWALL_USER*/
+
+#ifdef DEBUG_IP_FIREWALL
+#define dprintf(format, args...)  printk(format , ## args)
+#else
+#define dprintf(format, args...)
+#endif
+
+#ifdef DEBUG_IP_FIREWALL_USER
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+#ifdef CONFIG_NETFILTER_DEBUG
+#define IP_NF_ASSERT(x)						\
+do {								\
+	if (!(x))						\
+		printk("IP_NF_ASSERT: %s:%s:%u\n",		\
+		       __func__, __FILE__, __LINE__);	\
+} while(0)
+#else
+#define IP_NF_ASSERT(x)
+#endif
+
+#if 0
+/* All the better to debug you with... */
+#define static
+#define inline
+#endif
+
+/*
+   We keep a set of rules for each CPU, so we can avoid write-locking
+   them in the softirq when updating the counters and therefore
+   only need to read-lock in the softirq; doing a write_lock_bh() in user
+   context stops packets coming through and allows user context to read
+   the counters or update the rules.
+
+   Hence the start of any table is given by get_table() below.  */
+
+/* Returns whether matches rule or not. */
+/* Performance critical - called for every packet */
+static inline bool
+ip_packet_match(const struct iphdr *ip,
+		const char *indev,
+		const char *outdev,
+		const struct ipt_ip *ipinfo,
+		int isfrag)
+{
+	size_t i;
+	unsigned long ret;
+
+#define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
+
+	if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
+		  IPT_INV_SRCIP)
+	    || FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
+		     IPT_INV_DSTIP)) {
+		dprintf("Source or dest mismatch.\n");
+
+		dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
+			NIPQUAD(ip->saddr),
+			NIPQUAD(ipinfo->smsk.s_addr),
+			NIPQUAD(ipinfo->src.s_addr),
+			ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
+		dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
+			NIPQUAD(ip->daddr),
+			NIPQUAD(ipinfo->dmsk.s_addr),
+			NIPQUAD(ipinfo->dst.s_addr),
+			ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
+		return false;
+	}
+
+	/* Look for ifname matches; this should unroll nicely. */
+	for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
+		ret |= (((const unsigned long *)indev)[i]
+			^ ((const unsigned long *)ipinfo->iniface)[i])
+			& ((const unsigned long *)ipinfo->iniface_mask)[i];
+	}
+
+	if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
+		dprintf("VIA in mismatch (%s vs %s).%s\n",
+			indev, ipinfo->iniface,
+			ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
+		return false;
+	}
+
+	for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
+		ret |= (((const unsigned long *)outdev)[i]
+			^ ((const unsigned long *)ipinfo->outiface)[i])
+			& ((const unsigned long *)ipinfo->outiface_mask)[i];
+	}
+
+	if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
+		dprintf("VIA out mismatch (%s vs %s).%s\n",
+			outdev, ipinfo->outiface,
+			ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
+		return false;
+	}
+
+	/* Check specific protocol */
+	if (ipinfo->proto
+	    && FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
+		dprintf("Packet protocol %hi does not match %hi.%s\n",
+			ip->protocol, ipinfo->proto,
+			ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
+		return false;
+	}
+
+	/* If we have a fragment rule but the packet is not a fragment
+	 * then we return zero */
+	if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
+		dprintf("Fragment rule but not fragment.%s\n",
+			ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
+		return false;
+	}
+
+	return true;
+}
+
+static bool
+ip_checkentry(const struct ipt_ip *ip)
+{
+	if (ip->flags & ~IPT_F_MASK) {
+		duprintf("Unknown flag bits set: %08X\n",
+			 ip->flags & ~IPT_F_MASK);
+		return false;
+	}
+	if (ip->invflags & ~IPT_INV_MASK) {
+		duprintf("Unknown invflag bits set: %08X\n",
+			 ip->invflags & ~IPT_INV_MASK);
+		return false;
+	}
+	return true;
+}
+
+static unsigned int
+ipt_error(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	if (net_ratelimit())
+		printk("ip_tables: error: `%s'\n",
+		       (const char *)par->targinfo);
+
+	return NF_DROP;
+}
+
+/* Performance critical - called for every packet */
+static inline bool
+do_match(struct ipt_entry_match *m, const struct sk_buff *skb,
+	 struct xt_match_param *par)
+{
+	par->match     = m->u.kernel.match;
+	par->matchinfo = m->data;
+
+	/* Stop iteration if it doesn't match */
+	if (!m->u.kernel.match->match(skb, par))
+		return true;
+	else
+		return false;
+}
+
+/* Performance critical */
+static inline struct ipt_entry *
+get_entry(void *base, unsigned int offset)
+{
+	return (struct ipt_entry *)(base + offset);
+}
+
+/* All zeroes == unconditional rule. */
+/* Mildly perf critical (only if packet tracing is on) */
+static inline int
+unconditional(const struct ipt_ip *ip)
+{
+	unsigned int i;
+
+	for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
+		if (((__u32 *)ip)[i])
+			return 0;
+
+	return 1;
+#undef FWINV
+}
+
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+static const char *const hooknames[] = {
+	[NF_INET_PRE_ROUTING]		= "PREROUTING",
+	[NF_INET_LOCAL_IN]		= "INPUT",
+	[NF_INET_FORWARD]		= "FORWARD",
+	[NF_INET_LOCAL_OUT]		= "OUTPUT",
+	[NF_INET_POST_ROUTING]		= "POSTROUTING",
+};
+
+enum nf_ip_trace_comments {
+	NF_IP_TRACE_COMMENT_RULE,
+	NF_IP_TRACE_COMMENT_RETURN,
+	NF_IP_TRACE_COMMENT_POLICY,
+};
+
+static const char *const comments[] = {
+	[NF_IP_TRACE_COMMENT_RULE]	= "rule",
+	[NF_IP_TRACE_COMMENT_RETURN]	= "return",
+	[NF_IP_TRACE_COMMENT_POLICY]	= "policy",
+};
+
+static struct nf_loginfo trace_loginfo = {
+	.type = NF_LOG_TYPE_LOG,
+	.u = {
+		.log = {
+			.level = 4,
+			.logflags = NF_LOG_MASK,
+		},
+	},
+};
+
+/* Mildly perf critical (only if packet tracing is on) */
+static inline int
+get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
+		      char *hookname, char **chainname,
+		      char **comment, unsigned int *rulenum)
+{
+	struct ipt_standard_target *t = (void *)ipt_get_target(s);
+
+	if (strcmp(t->target.u.kernel.target->name, IPT_ERROR_TARGET) == 0) {
+		/* Head of user chain: ERROR target with chainname */
+		*chainname = t->target.data;
+		(*rulenum) = 0;
+	} else if (s == e) {
+		(*rulenum)++;
+
+		if (s->target_offset == sizeof(struct ipt_entry)
+		   && strcmp(t->target.u.kernel.target->name,
+			     IPT_STANDARD_TARGET) == 0
+		   && t->verdict < 0
+		   && unconditional(&s->ip)) {
+			/* Tail of chains: STANDARD target (return/policy) */
+			*comment = *chainname == hookname
+				? (char *)comments[NF_IP_TRACE_COMMENT_POLICY]
+				: (char *)comments[NF_IP_TRACE_COMMENT_RETURN];
+		}
+		return 1;
+	} else
+		(*rulenum)++;
+
+	return 0;
+}
+
+static void trace_packet(struct sk_buff *skb,
+			 unsigned int hook,
+			 const struct net_device *in,
+			 const struct net_device *out,
+			 const char *tablename,
+			 struct xt_table_info *private,
+			 struct ipt_entry *e)
+{
+	void *table_base;
+	const struct ipt_entry *root;
+	char *hookname, *chainname, *comment;
+	unsigned int rulenum = 0;
+
+	table_base = (void *)private->entries[smp_processor_id()];
+	root = get_entry(table_base, private->hook_entry[hook]);
+
+	hookname = chainname = (char *)hooknames[hook];
+	comment = (char *)comments[NF_IP_TRACE_COMMENT_RULE];
+
+	IPT_ENTRY_ITERATE(root,
+			  private->size - private->hook_entry[hook],
+			  get_chainname_rulenum,
+			  e, hookname, &chainname, &comment, &rulenum);
+
+	nf_log_packet(AF_INET, hook, skb, in, out, &trace_loginfo,
+		      "TRACE: %s:%s:%s:%u ",
+		      tablename, chainname, comment, rulenum);
+}
+#endif
+
+/* Returns one of the generic firewall policies, like NF_ACCEPT. */
+unsigned int
+ipt_do_table(struct sk_buff *skb,
+	     unsigned int hook,
+	     const struct net_device *in,
+	     const struct net_device *out,
+	     struct xt_table *table)
+{
+	static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
+	const struct iphdr *ip;
+	u_int16_t datalen;
+	bool hotdrop = false;
+	/* Initializing verdict to NF_DROP keeps gcc happy. */
+	unsigned int verdict = NF_DROP;
+	const char *indev, *outdev;
+	void *table_base;
+	struct ipt_entry *e, *back;
+	struct xt_table_info *private;
+	struct xt_match_param mtpar;
+	struct xt_target_param tgpar;
+
+	/* Initialization */
+	ip = ip_hdr(skb);
+	datalen = skb->len - ip->ihl * 4;
+	indev = in ? in->name : nulldevname;
+	outdev = out ? out->name : nulldevname;
+	/* We handle fragments by dealing with the first fragment as
+	 * if it was a normal packet.  All other fragments are treated
+	 * normally, except that they will NEVER match rules that ask
+	 * things we don't know, ie. tcp syn flag or ports).  If the
+	 * rule is also a fragment-specific rule, non-fragments won't
+	 * match it. */
+	mtpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
+	mtpar.thoff   = ip_hdrlen(skb);
+	mtpar.hotdrop = &hotdrop;
+	mtpar.in      = tgpar.in  = in;
+	mtpar.out     = tgpar.out = out;
+	mtpar.family  = tgpar.family = NFPROTO_IPV4;
+	tgpar.hooknum = hook;
+
+	read_lock_bh(&table->lock);
+	IP_NF_ASSERT(table->valid_hooks & (1 << hook));
+	private = table->private;
+	table_base = (void *)private->entries[smp_processor_id()];
+	e = get_entry(table_base, private->hook_entry[hook]);
+
+	/* For return from builtin chain */
+	back = get_entry(table_base, private->underflow[hook]);
+
+	do {
+		IP_NF_ASSERT(e);
+		IP_NF_ASSERT(back);
+		if (ip_packet_match(ip, indev, outdev,
+		    &e->ip, mtpar.fragoff)) {
+			struct ipt_entry_target *t;
+
+			if (IPT_MATCH_ITERATE(e, do_match, skb, &mtpar) != 0)
+				goto no_match;
+
+			ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
+
+			t = ipt_get_target(e);
+			IP_NF_ASSERT(t->u.kernel.target);
+
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+    defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+			/* The packet is traced: log it */
+			if (unlikely(skb->nf_trace))
+				trace_packet(skb, hook, in, out,
+					     table->name, private, e);
+#endif
+			/* Standard target? */
+			if (!t->u.kernel.target->target) {
+				int v;
+
+				v = ((struct ipt_standard_target *)t)->verdict;
+				if (v < 0) {
+					/* Pop from stack? */
+					if (v != IPT_RETURN) {
+						verdict = (unsigned)(-v) - 1;
+						break;
+					}
+					e = back;
+					back = get_entry(table_base,
+							 back->comefrom);
+					continue;
+				}
+				if (table_base + v != (void *)e + e->next_offset
+				    && !(e->ip.flags & IPT_F_GOTO)) {
+					/* Save old back ptr in next entry */
+					struct ipt_entry *next
+						= (void *)e + e->next_offset;
+					next->comefrom
+						= (void *)back - table_base;
+					/* set back pointer to next entry */
+					back = next;
+				}
+
+				e = get_entry(table_base, v);
+			} else {
+				/* Targets which reenter must return
+				   abs. verdicts */
+				tgpar.target   = t->u.kernel.target;
+				tgpar.targinfo = t->data;
+#ifdef CONFIG_NETFILTER_DEBUG
+				((struct ipt_entry *)table_base)->comefrom
+					= 0xeeeeeeec;
+#endif
+				verdict = t->u.kernel.target->target(skb,
+								     &tgpar);
+#ifdef CONFIG_NETFILTER_DEBUG
+				if (((struct ipt_entry *)table_base)->comefrom
+				    != 0xeeeeeeec
+				    && verdict == IPT_CONTINUE) {
+					printk("Target %s reentered!\n",
+					       t->u.kernel.target->name);
+					verdict = NF_DROP;
+				}
+				((struct ipt_entry *)table_base)->comefrom
+					= 0x57acc001;
+#endif
+				/* Target might have changed stuff. */
+				ip = ip_hdr(skb);
+				datalen = skb->len - ip->ihl * 4;
+
+				if (verdict == IPT_CONTINUE)
+					e = (void *)e + e->next_offset;
+				else
+					/* Verdict */
+					break;
+			}
+		} else {
+
+		no_match:
+			e = (void *)e + e->next_offset;
+		}
+	} while (!hotdrop);
+
+	read_unlock_bh(&table->lock);
+
+#ifdef DEBUG_ALLOW_ALL
+	return NF_ACCEPT;
+#else
+	if (hotdrop)
+		return NF_DROP;
+	else return verdict;
+#endif
+}
+
+/* Figures out from what hook each rule can be called: returns 0 if
+   there are loops.  Puts hook bitmask in comefrom. */
+static int
+mark_source_chains(struct xt_table_info *newinfo,
+		   unsigned int valid_hooks, void *entry0)
+{
+	unsigned int hook;
+
+	/* No recursion; use packet counter to save back ptrs (reset
+	   to 0 as we leave), and comefrom to save source hook bitmask */
+	for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) {
+		unsigned int pos = newinfo->hook_entry[hook];
+		struct ipt_entry *e = (struct ipt_entry *)(entry0 + pos);
+
+		if (!(valid_hooks & (1 << hook)))
+			continue;
+
+		/* Set initial back pointer. */
+		e->counters.pcnt = pos;
+
+		for (;;) {
+			struct ipt_standard_target *t
+				= (void *)ipt_get_target(e);
+			int visited = e->comefrom & (1 << hook);
+
+			if (e->comefrom & (1 << NF_INET_NUMHOOKS)) {
+				printk("iptables: loop hook %u pos %u %08X.\n",
+				       hook, pos, e->comefrom);
+				return 0;
+			}
+			e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS));
+
+			/* Unconditional return/END. */
+			if ((e->target_offset == sizeof(struct ipt_entry)
+			    && (strcmp(t->target.u.user.name,
+				       IPT_STANDARD_TARGET) == 0)
+			    && t->verdict < 0
+			    && unconditional(&e->ip)) || visited) {
+				unsigned int oldpos, size;
+
+				if (t->verdict < -NF_MAX_VERDICT - 1) {
+					duprintf("mark_source_chains: bad "
+						"negative verdict (%i)\n",
+								t->verdict);
+					return 0;
+				}
+
+				/* Return: backtrack through the last
+				   big jump. */
+				do {
+					e->comefrom ^= (1<<NF_INET_NUMHOOKS);
+#ifdef DEBUG_IP_FIREWALL_USER
+					if (e->comefrom
+					    & (1 << NF_INET_NUMHOOKS)) {
+						duprintf("Back unset "
+							 "on hook %u "
+							 "rule %u\n",
+							 hook, pos);
+					}
+#endif
+					oldpos = pos;
+					pos = e->counters.pcnt;
+					e->counters.pcnt = 0;
+
+					/* We're at the start. */
+					if (pos == oldpos)
+						goto next;
+
+					e = (struct ipt_entry *)
+						(entry0 + pos);
+				} while (oldpos == pos + e->next_offset);
+
+				/* Move along one */
+				size = e->next_offset;
+				e = (struct ipt_entry *)
+					(entry0 + pos + size);
+				e->counters.pcnt = pos;
+				pos += size;
+			} else {
+				int newpos = t->verdict;
+
+				if (strcmp(t->target.u.user.name,
+					   IPT_STANDARD_TARGET) == 0
+				    && newpos >= 0) {
+					if (newpos > newinfo->size -
+						sizeof(struct ipt_entry)) {
+						duprintf("mark_source_chains: "
+							"bad verdict (%i)\n",
+								newpos);
+						return 0;
+					}
+					/* This a jump; chase it. */
+					duprintf("Jump rule %u -> %u\n",
+						 pos, newpos);
+				} else {
+					/* ... this is a fallthru */
+					newpos = pos + e->next_offset;
+				}
+				e = (struct ipt_entry *)
+					(entry0 + newpos);
+				e->counters.pcnt = pos;
+				pos = newpos;
+			}
+		}
+		next:
+		duprintf("Finished chain %u\n", hook);
+	}
+	return 1;
+}
+
+static int
+cleanup_match(struct ipt_entry_match *m, unsigned int *i)
+{
+	struct xt_mtdtor_param par;
+
+	if (i && (*i)-- == 0)
+		return 1;
+
+	par.match     = m->u.kernel.match;
+	par.matchinfo = m->data;
+	par.family    = NFPROTO_IPV4;
+	if (par.match->destroy != NULL)
+		par.match->destroy(&par);
+	module_put(par.match->me);
+	return 0;
+}
+
+static int
+check_entry(struct ipt_entry *e, const char *name)
+{
+	struct ipt_entry_target *t;
+
+	if (!ip_checkentry(&e->ip)) {
+		duprintf("ip_tables: ip check failed %p %s.\n", e, name);
+		return -EINVAL;
+	}
+
+	if (e->target_offset + sizeof(struct ipt_entry_target) >
+	    e->next_offset)
+		return -EINVAL;
+
+	t = ipt_get_target(e);
+	if (e->target_offset + t->u.target_size > e->next_offset)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int
+check_match(struct ipt_entry_match *m, struct xt_mtchk_param *par,
+	    unsigned int *i)
+{
+	const struct ipt_ip *ip = par->entryinfo;
+	int ret;
+
+	par->match     = m->u.kernel.match;
+	par->matchinfo = m->data;
+
+	ret = xt_check_match(par, m->u.match_size - sizeof(*m),
+	      ip->proto, ip->invflags & IPT_INV_PROTO);
+	if (ret < 0) {
+		duprintf("ip_tables: check failed for `%s'.\n",
+			 par.match->name);
+		return ret;
+	}
+	++*i;
+	return 0;
+}
+
+static int
+find_check_match(struct ipt_entry_match *m, struct xt_mtchk_param *par,
+		 unsigned int *i)
+{
+	struct xt_match *match;
+	int ret;
+
+	match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
+						      m->u.user.revision),
+					"ipt_%s", m->u.user.name);
+	if (IS_ERR(match) || !match) {
+		duprintf("find_check_match: `%s' not found\n", m->u.user.name);
+		return match ? PTR_ERR(match) : -ENOENT;
+	}
+	m->u.kernel.match = match;
+
+	ret = check_match(m, par, i);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	module_put(m->u.kernel.match->me);
+	return ret;
+}
+
+static int check_target(struct ipt_entry *e, const char *name)
+{
+	struct ipt_entry_target *t = ipt_get_target(e);
+	struct xt_tgchk_param par = {
+		.table     = name,
+		.entryinfo = e,
+		.target    = t->u.kernel.target,
+		.targinfo  = t->data,
+		.hook_mask = e->comefrom,
+		.family    = NFPROTO_IPV4,
+	};
+	int ret;
+
+	ret = xt_check_target(&par, t->u.target_size - sizeof(*t),
+	      e->ip.proto, e->ip.invflags & IPT_INV_PROTO);
+	if (ret < 0) {
+		duprintf("ip_tables: check failed for `%s'.\n",
+			 t->u.kernel.target->name);
+		return ret;
+	}
+	return 0;
+}
+
+static int
+find_check_entry(struct ipt_entry *e, const char *name, unsigned int size,
+		 unsigned int *i)
+{
+	struct ipt_entry_target *t;
+	struct xt_target *target;
+	int ret;
+	unsigned int j;
+	struct xt_mtchk_param mtpar;
+
+	ret = check_entry(e, name);
+	if (ret)
+		return ret;
+
+	j = 0;
+	mtpar.table     = name;
+	mtpar.entryinfo = &e->ip;
+	mtpar.hook_mask = e->comefrom;
+	mtpar.family    = NFPROTO_IPV4;
+	ret = IPT_MATCH_ITERATE(e, find_check_match, &mtpar, &j);
+	if (ret != 0)
+		goto cleanup_matches;
+
+	t = ipt_get_target(e);
+	target = try_then_request_module(xt_find_target(AF_INET,
+							t->u.user.name,
+							t->u.user.revision),
+					 "ipt_%s", t->u.user.name);
+	if (IS_ERR(target) || !target) {
+		duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
+		ret = target ? PTR_ERR(target) : -ENOENT;
+		goto cleanup_matches;
+	}
+	t->u.kernel.target = target;
+
+	ret = check_target(e, name);
+	if (ret)
+		goto err;
+
+	(*i)++;
+	return 0;
+ err:
+	module_put(t->u.kernel.target->me);
+ cleanup_matches:
+	IPT_MATCH_ITERATE(e, cleanup_match, &j);
+	return ret;
+}
+
+static int
+check_entry_size_and_hooks(struct ipt_entry *e,
+			   struct xt_table_info *newinfo,
+			   unsigned char *base,
+			   unsigned char *limit,
+			   const unsigned int *hook_entries,
+			   const unsigned int *underflows,
+			   unsigned int *i)
+{
+	unsigned int h;
+
+	if ((unsigned long)e % __alignof__(struct ipt_entry) != 0
+	    || (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
+		duprintf("Bad offset %p\n", e);
+		return -EINVAL;
+	}
+
+	if (e->next_offset
+	    < sizeof(struct ipt_entry) + sizeof(struct ipt_entry_target)) {
+		duprintf("checking: element %p size %u\n",
+			 e, e->next_offset);
+		return -EINVAL;
+	}
+
+	/* Check hooks & underflows */
+	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
+		if ((unsigned char *)e - base == hook_entries[h])
+			newinfo->hook_entry[h] = hook_entries[h];
+		if ((unsigned char *)e - base == underflows[h])
+			newinfo->underflow[h] = underflows[h];
+	}
+
+	/* FIXME: underflows must be unconditional, standard verdicts
+	   < 0 (not IPT_RETURN). --RR */
+
+	/* Clear counters and comefrom */
+	e->counters = ((struct xt_counters) { 0, 0 });
+	e->comefrom = 0;
+
+	(*i)++;
+	return 0;
+}
+
+static int
+cleanup_entry(struct ipt_entry *e, unsigned int *i)
+{
+	struct xt_tgdtor_param par;
+	struct ipt_entry_target *t;
+
+	if (i && (*i)-- == 0)
+		return 1;
+
+	/* Cleanup all matches */
+	IPT_MATCH_ITERATE(e, cleanup_match, NULL);
+	t = ipt_get_target(e);
+
+	par.target   = t->u.kernel.target;
+	par.targinfo = t->data;
+	par.family   = NFPROTO_IPV4;
+	if (par.target->destroy != NULL)
+		par.target->destroy(&par);
+	module_put(par.target->me);
+	return 0;
+}
+
+/* Checks and translates the user-supplied table segment (held in
+   newinfo) */
+static int
+translate_table(const char *name,
+		unsigned int valid_hooks,
+		struct xt_table_info *newinfo,
+		void *entry0,
+		unsigned int size,
+		unsigned int number,
+		const unsigned int *hook_entries,
+		const unsigned int *underflows)
+{
+	unsigned int i;
+	int ret;
+
+	newinfo->size = size;
+	newinfo->number = number;
+
+	/* Init all hooks to impossible value. */
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		newinfo->hook_entry[i] = 0xFFFFFFFF;
+		newinfo->underflow[i] = 0xFFFFFFFF;
+	}
+
+	duprintf("translate_table: size %u\n", newinfo->size);
+	i = 0;
+	/* Walk through entries, checking offsets. */
+	ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
+				check_entry_size_and_hooks,
+				newinfo,
+				entry0,
+				entry0 + size,
+				hook_entries, underflows, &i);
+	if (ret != 0)
+		return ret;
+
+	if (i != number) {
+		duprintf("translate_table: %u not %u entries\n",
+			 i, number);
+		return -EINVAL;
+	}
+
+	/* Check hooks all assigned */
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		/* Only hooks which are valid */
+		if (!(valid_hooks & (1 << i)))
+			continue;
+		if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
+			duprintf("Invalid hook entry %u %u\n",
+				 i, hook_entries[i]);
+			return -EINVAL;
+		}
+		if (newinfo->underflow[i] == 0xFFFFFFFF) {
+			duprintf("Invalid underflow %u %u\n",
+				 i, underflows[i]);
+			return -EINVAL;
+		}
+	}
+
+	if (!mark_source_chains(newinfo, valid_hooks, entry0))
+		return -ELOOP;
+
+	/* Finally, each sanity check must pass */
+	i = 0;
+	ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
+				find_check_entry, name, size, &i);
+
+	if (ret != 0) {
+		IPT_ENTRY_ITERATE(entry0, newinfo->size,
+				cleanup_entry, &i);
+		return ret;
+	}
+
+	/* And one copy for every other CPU */
+	for_each_possible_cpu(i) {
+		if (newinfo->entries[i] && newinfo->entries[i] != entry0)
+			memcpy(newinfo->entries[i], entry0, newinfo->size);
+	}
+
+	return ret;
+}
+
+/* Gets counters. */
+static inline int
+add_entry_to_counter(const struct ipt_entry *e,
+		     struct xt_counters total[],
+		     unsigned int *i)
+{
+	ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+
+	(*i)++;
+	return 0;
+}
+
+static inline int
+set_entry_to_counter(const struct ipt_entry *e,
+		     struct ipt_counters total[],
+		     unsigned int *i)
+{
+	SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
+
+	(*i)++;
+	return 0;
+}
+
+static void
+get_counters(const struct xt_table_info *t,
+	     struct xt_counters counters[])
+{
+	unsigned int cpu;
+	unsigned int i;
+	unsigned int curcpu;
+
+	/* Instead of clearing (by a previous call to memset())
+	 * the counters and using adds, we set the counters
+	 * with data used by 'current' CPU
+	 * We dont care about preemption here.
+	 */
+	curcpu = raw_smp_processor_id();
+
+	i = 0;
+	IPT_ENTRY_ITERATE(t->entries[curcpu],
+			  t->size,
+			  set_entry_to_counter,
+			  counters,
+			  &i);
+
+	for_each_possible_cpu(cpu) {
+		if (cpu == curcpu)
+			continue;
+		i = 0;
+		IPT_ENTRY_ITERATE(t->entries[cpu],
+				  t->size,
+				  add_entry_to_counter,
+				  counters,
+				  &i);
+	}
+}
+
+static struct xt_counters * alloc_counters(struct xt_table *table)
+{
+	unsigned int countersize;
+	struct xt_counters *counters;
+	const struct xt_table_info *private = table->private;
+
+	/* We need atomic snapshot of counters: rest doesn't change
+	   (other than comefrom, which userspace doesn't care
+	   about). */
+	countersize = sizeof(struct xt_counters) * private->number;
+	counters = vmalloc_node(countersize, numa_node_id());
+
+	if (counters == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	/* First, sum counters... */
+	write_lock_bh(&table->lock);
+	get_counters(private, counters);
+	write_unlock_bh(&table->lock);
+
+	return counters;
+}
+
+static int
+copy_entries_to_user(unsigned int total_size,
+		     struct xt_table *table,
+		     void __user *userptr)
+{
+	unsigned int off, num;
+	struct ipt_entry *e;
+	struct xt_counters *counters;
+	const struct xt_table_info *private = table->private;
+	int ret = 0;
+	const void *loc_cpu_entry;
+
+	counters = alloc_counters(table);
+	if (IS_ERR(counters))
+		return PTR_ERR(counters);
+
+	/* choose the copy that is on our node/cpu, ...
+	 * This choice is lazy (because current thread is
+	 * allowed to migrate to another cpu)
+	 */
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
+		ret = -EFAULT;
+		goto free_counters;
+	}
+
+	/* FIXME: use iterator macros --RR */
+	/* ... then go back and fix counters and names */
+	for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
+		unsigned int i;
+		const struct ipt_entry_match *m;
+		const struct ipt_entry_target *t;
+
+		e = (struct ipt_entry *)(loc_cpu_entry + off);
+		if (copy_to_user(userptr + off
+				 + offsetof(struct ipt_entry, counters),
+				 &counters[num],
+				 sizeof(counters[num])) != 0) {
+			ret = -EFAULT;
+			goto free_counters;
+		}
+
+		for (i = sizeof(struct ipt_entry);
+		     i < e->target_offset;
+		     i += m->u.match_size) {
+			m = (void *)e + i;
+
+			if (copy_to_user(userptr + off + i
+					 + offsetof(struct ipt_entry_match,
+						    u.user.name),
+					 m->u.kernel.match->name,
+					 strlen(m->u.kernel.match->name)+1)
+			    != 0) {
+				ret = -EFAULT;
+				goto free_counters;
+			}
+		}
+
+		t = ipt_get_target(e);
+		if (copy_to_user(userptr + off + e->target_offset
+				 + offsetof(struct ipt_entry_target,
+					    u.user.name),
+				 t->u.kernel.target->name,
+				 strlen(t->u.kernel.target->name)+1) != 0) {
+			ret = -EFAULT;
+			goto free_counters;
+		}
+	}
+
+ free_counters:
+	vfree(counters);
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static void compat_standard_from_user(void *dst, void *src)
+{
+	int v = *(compat_int_t *)src;
+
+	if (v > 0)
+		v += xt_compat_calc_jump(AF_INET, v);
+	memcpy(dst, &v, sizeof(v));
+}
+
+static int compat_standard_to_user(void __user *dst, void *src)
+{
+	compat_int_t cv = *(int *)src;
+
+	if (cv > 0)
+		cv -= xt_compat_calc_jump(AF_INET, cv);
+	return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
+}
+
+static inline int
+compat_calc_match(struct ipt_entry_match *m, int *size)
+{
+	*size += xt_compat_match_offset(m->u.kernel.match);
+	return 0;
+}
+
+static int compat_calc_entry(struct ipt_entry *e,
+			     const struct xt_table_info *info,
+			     void *base, struct xt_table_info *newinfo)
+{
+	struct ipt_entry_target *t;
+	unsigned int entry_offset;
+	int off, i, ret;
+
+	off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
+	entry_offset = (void *)e - base;
+	IPT_MATCH_ITERATE(e, compat_calc_match, &off);
+	t = ipt_get_target(e);
+	off += xt_compat_target_offset(t->u.kernel.target);
+	newinfo->size -= off;
+	ret = xt_compat_add_offset(AF_INET, entry_offset, off);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		if (info->hook_entry[i] &&
+		    (e < (struct ipt_entry *)(base + info->hook_entry[i])))
+			newinfo->hook_entry[i] -= off;
+		if (info->underflow[i] &&
+		    (e < (struct ipt_entry *)(base + info->underflow[i])))
+			newinfo->underflow[i] -= off;
+	}
+	return 0;
+}
+
+static int compat_table_info(const struct xt_table_info *info,
+			     struct xt_table_info *newinfo)
+{
+	void *loc_cpu_entry;
+
+	if (!newinfo || !info)
+		return -EINVAL;
+
+	/* we dont care about newinfo->entries[] */
+	memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
+	newinfo->initial_entries = 0;
+	loc_cpu_entry = info->entries[raw_smp_processor_id()];
+	return IPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
+				 compat_calc_entry, info, loc_cpu_entry,
+				 newinfo);
+}
+#endif
+
+static int get_info(struct net *net, void __user *user, int *len, int compat)
+{
+	char name[IPT_TABLE_MAXNAMELEN];
+	struct xt_table *t;
+	int ret;
+
+	if (*len != sizeof(struct ipt_getinfo)) {
+		duprintf("length %u != %zu\n", *len,
+			 sizeof(struct ipt_getinfo));
+		return -EINVAL;
+	}
+
+	if (copy_from_user(name, user, sizeof(name)) != 0)
+		return -EFAULT;
+
+	name[IPT_TABLE_MAXNAMELEN-1] = '\0';
+#ifdef CONFIG_COMPAT
+	if (compat)
+		xt_compat_lock(AF_INET);
+#endif
+	t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
+				    "iptable_%s", name);
+	if (t && !IS_ERR(t)) {
+		struct ipt_getinfo info;
+		const struct xt_table_info *private = t->private;
+
+#ifdef CONFIG_COMPAT
+		if (compat) {
+			struct xt_table_info tmp;
+			ret = compat_table_info(private, &tmp);
+			xt_compat_flush_offsets(AF_INET);
+			private = &tmp;
+		}
+#endif
+		info.valid_hooks = t->valid_hooks;
+		memcpy(info.hook_entry, private->hook_entry,
+		       sizeof(info.hook_entry));
+		memcpy(info.underflow, private->underflow,
+		       sizeof(info.underflow));
+		info.num_entries = private->number;
+		info.size = private->size;
+		strcpy(info.name, name);
+
+		if (copy_to_user(user, &info, *len) != 0)
+			ret = -EFAULT;
+		else
+			ret = 0;
+
+		xt_table_unlock(t);
+		module_put(t->me);
+	} else
+		ret = t ? PTR_ERR(t) : -ENOENT;
+#ifdef CONFIG_COMPAT
+	if (compat)
+		xt_compat_unlock(AF_INET);
+#endif
+	return ret;
+}
+
+static int
+get_entries(struct net *net, struct ipt_get_entries __user *uptr, int *len)
+{
+	int ret;
+	struct ipt_get_entries get;
+	struct xt_table *t;
+
+	if (*len < sizeof(get)) {
+		duprintf("get_entries: %u < %zu\n", *len, sizeof(get));
+		return -EINVAL;
+	}
+	if (copy_from_user(&get, uptr, sizeof(get)) != 0)
+		return -EFAULT;
+	if (*len != sizeof(struct ipt_get_entries) + get.size) {
+		duprintf("get_entries: %u != %zu\n",
+			 *len, sizeof(get) + get.size);
+		return -EINVAL;
+	}
+
+	t = xt_find_table_lock(net, AF_INET, get.name);
+	if (t && !IS_ERR(t)) {
+		const struct xt_table_info *private = t->private;
+		duprintf("t->private->number = %u\n", private->number);
+		if (get.size == private->size)
+			ret = copy_entries_to_user(private->size,
+						   t, uptr->entrytable);
+		else {
+			duprintf("get_entries: I've got %u not %u!\n",
+				 private->size, get.size);
+			ret = -EAGAIN;
+		}
+		module_put(t->me);
+		xt_table_unlock(t);
+	} else
+		ret = t ? PTR_ERR(t) : -ENOENT;
+
+	return ret;
+}
+
+static int
+__do_replace(struct net *net, const char *name, unsigned int valid_hooks,
+	     struct xt_table_info *newinfo, unsigned int num_counters,
+	     void __user *counters_ptr)
+{
+	int ret;
+	struct xt_table *t;
+	struct xt_table_info *oldinfo;
+	struct xt_counters *counters;
+	void *loc_cpu_old_entry;
+
+	ret = 0;
+	counters = vmalloc(num_counters * sizeof(struct xt_counters));
+	if (!counters) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	t = try_then_request_module(xt_find_table_lock(net, AF_INET, name),
+				    "iptable_%s", name);
+	if (!t || IS_ERR(t)) {
+		ret = t ? PTR_ERR(t) : -ENOENT;
+		goto free_newinfo_counters_untrans;
+	}
+
+	/* You lied! */
+	if (valid_hooks != t->valid_hooks) {
+		duprintf("Valid hook crap: %08X vs %08X\n",
+			 valid_hooks, t->valid_hooks);
+		ret = -EINVAL;
+		goto put_module;
+	}
+
+	oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
+	if (!oldinfo)
+		goto put_module;
+
+	/* Update module usage count based on number of rules */
+	duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
+		oldinfo->number, oldinfo->initial_entries, newinfo->number);
+	if ((oldinfo->number > oldinfo->initial_entries) ||
+	    (newinfo->number <= oldinfo->initial_entries))
+		module_put(t->me);
+	if ((oldinfo->number > oldinfo->initial_entries) &&
+	    (newinfo->number <= oldinfo->initial_entries))
+		module_put(t->me);
+
+	/* Get the old counters. */
+	get_counters(oldinfo, counters);
+	/* Decrease module usage counts and free resource */
+	loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
+	IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,
+			  NULL);
+	xt_free_table_info(oldinfo);
+	if (copy_to_user(counters_ptr, counters,
+			 sizeof(struct xt_counters) * num_counters) != 0)
+		ret = -EFAULT;
+	vfree(counters);
+	xt_table_unlock(t);
+	return ret;
+
+ put_module:
+	module_put(t->me);
+	xt_table_unlock(t);
+ free_newinfo_counters_untrans:
+	vfree(counters);
+ out:
+	return ret;
+}
+
+static int
+do_replace(struct net *net, void __user *user, unsigned int len)
+{
+	int ret;
+	struct ipt_replace tmp;
+	struct xt_table_info *newinfo;
+	void *loc_cpu_entry;
+
+	if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
+		return -EFAULT;
+
+	/* overflow check */
+	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
+		return -ENOMEM;
+
+	newinfo = xt_alloc_table_info(tmp.size);
+	if (!newinfo)
+		return -ENOMEM;
+
+	/* choose the copy that is on our node/cpu */
+	loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+	if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
+			   tmp.size) != 0) {
+		ret = -EFAULT;
+		goto free_newinfo;
+	}
+
+	ret = translate_table(tmp.name, tmp.valid_hooks,
+			      newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
+			      tmp.hook_entry, tmp.underflow);
+	if (ret != 0)
+		goto free_newinfo;
+
+	duprintf("ip_tables: Translated table\n");
+
+	ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
+			   tmp.num_counters, tmp.counters);
+	if (ret)
+		goto free_newinfo_untrans;
+	return 0;
+
+ free_newinfo_untrans:
+	IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
+ free_newinfo:
+	xt_free_table_info(newinfo);
+	return ret;
+}
+
+/* We're lazy, and add to the first CPU; overflow works its fey magic
+ * and everything is OK. */
+static int
+add_counter_to_entry(struct ipt_entry *e,
+		     const struct xt_counters addme[],
+		     unsigned int *i)
+{
+#if 0
+	duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
+		 *i,
+		 (long unsigned int)e->counters.pcnt,
+		 (long unsigned int)e->counters.bcnt,
+		 (long unsigned int)addme[*i].pcnt,
+		 (long unsigned int)addme[*i].bcnt);
+#endif
+
+	ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
+
+	(*i)++;
+	return 0;
+}
+
+static int
+do_add_counters(struct net *net, void __user *user, unsigned int len, int compat)
+{
+	unsigned int i;
+	struct xt_counters_info tmp;
+	struct xt_counters *paddc;
+	unsigned int num_counters;
+	const char *name;
+	int size;
+	void *ptmp;
+	struct xt_table *t;
+	const struct xt_table_info *private;
+	int ret = 0;
+	void *loc_cpu_entry;
+#ifdef CONFIG_COMPAT
+	struct compat_xt_counters_info compat_tmp;
+
+	if (compat) {
+		ptmp = &compat_tmp;
+		size = sizeof(struct compat_xt_counters_info);
+	} else
+#endif
+	{
+		ptmp = &tmp;
+		size = sizeof(struct xt_counters_info);
+	}
+
+	if (copy_from_user(ptmp, user, size) != 0)
+		return -EFAULT;
+
+#ifdef CONFIG_COMPAT
+	if (compat) {
+		num_counters = compat_tmp.num_counters;
+		name = compat_tmp.name;
+	} else
+#endif
+	{
+		num_counters = tmp.num_counters;
+		name = tmp.name;
+	}
+
+	if (len != size + num_counters * sizeof(struct xt_counters))
+		return -EINVAL;
+
+	paddc = vmalloc_node(len - size, numa_node_id());
+	if (!paddc)
+		return -ENOMEM;
+
+	if (copy_from_user(paddc, user + size, len - size) != 0) {
+		ret = -EFAULT;
+		goto free;
+	}
+
+	t = xt_find_table_lock(net, AF_INET, name);
+	if (!t || IS_ERR(t)) {
+		ret = t ? PTR_ERR(t) : -ENOENT;
+		goto free;
+	}
+
+	write_lock_bh(&t->lock);
+	private = t->private;
+	if (private->number != num_counters) {
+		ret = -EINVAL;
+		goto unlock_up_free;
+	}
+
+	i = 0;
+	/* Choose the copy that is on our node */
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	IPT_ENTRY_ITERATE(loc_cpu_entry,
+			  private->size,
+			  add_counter_to_entry,
+			  paddc,
+			  &i);
+ unlock_up_free:
+	write_unlock_bh(&t->lock);
+	xt_table_unlock(t);
+	module_put(t->me);
+ free:
+	vfree(paddc);
+
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_ipt_replace {
+	char			name[IPT_TABLE_MAXNAMELEN];
+	u32			valid_hooks;
+	u32			num_entries;
+	u32			size;
+	u32			hook_entry[NF_INET_NUMHOOKS];
+	u32			underflow[NF_INET_NUMHOOKS];
+	u32			num_counters;
+	compat_uptr_t		counters;	/* struct ipt_counters * */
+	struct compat_ipt_entry	entries[0];
+};
+
+static int
+compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr,
+			  unsigned int *size, struct xt_counters *counters,
+			  unsigned int *i)
+{
+	struct ipt_entry_target *t;
+	struct compat_ipt_entry __user *ce;
+	u_int16_t target_offset, next_offset;
+	compat_uint_t origsize;
+	int ret;
+
+	ret = -EFAULT;
+	origsize = *size;
+	ce = (struct compat_ipt_entry __user *)*dstptr;
+	if (copy_to_user(ce, e, sizeof(struct ipt_entry)))
+		goto out;
+
+	if (copy_to_user(&ce->counters, &counters[*i], sizeof(counters[*i])))
+		goto out;
+
+	*dstptr += sizeof(struct compat_ipt_entry);
+	*size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
+
+	ret = IPT_MATCH_ITERATE(e, xt_compat_match_to_user, dstptr, size);
+	target_offset = e->target_offset - (origsize - *size);
+	if (ret)
+		goto out;
+	t = ipt_get_target(e);
+	ret = xt_compat_target_to_user(t, dstptr, size);
+	if (ret)
+		goto out;
+	ret = -EFAULT;
+	next_offset = e->next_offset - (origsize - *size);
+	if (put_user(target_offset, &ce->target_offset))
+		goto out;
+	if (put_user(next_offset, &ce->next_offset))
+		goto out;
+
+	(*i)++;
+	return 0;
+out:
+	return ret;
+}
+
+static int
+compat_find_calc_match(struct ipt_entry_match *m,
+		       const char *name,
+		       const struct ipt_ip *ip,
+		       unsigned int hookmask,
+		       int *size, unsigned int *i)
+{
+	struct xt_match *match;
+
+	match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
+						      m->u.user.revision),
+					"ipt_%s", m->u.user.name);
+	if (IS_ERR(match) || !match) {
+		duprintf("compat_check_calc_match: `%s' not found\n",
+			 m->u.user.name);
+		return match ? PTR_ERR(match) : -ENOENT;
+	}
+	m->u.kernel.match = match;
+	*size += xt_compat_match_offset(match);
+
+	(*i)++;
+	return 0;
+}
+
+static int
+compat_release_match(struct ipt_entry_match *m, unsigned int *i)
+{
+	if (i && (*i)-- == 0)
+		return 1;
+
+	module_put(m->u.kernel.match->me);
+	return 0;
+}
+
+static int
+compat_release_entry(struct compat_ipt_entry *e, unsigned int *i)
+{
+	struct ipt_entry_target *t;
+
+	if (i && (*i)-- == 0)
+		return 1;
+
+	/* Cleanup all matches */
+	COMPAT_IPT_MATCH_ITERATE(e, compat_release_match, NULL);
+	t = compat_ipt_get_target(e);
+	module_put(t->u.kernel.target->me);
+	return 0;
+}
+
+static int
+check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,
+				  struct xt_table_info *newinfo,
+				  unsigned int *size,
+				  unsigned char *base,
+				  unsigned char *limit,
+				  unsigned int *hook_entries,
+				  unsigned int *underflows,
+				  unsigned int *i,
+				  const char *name)
+{
+	struct ipt_entry_target *t;
+	struct xt_target *target;
+	unsigned int entry_offset;
+	unsigned int j;
+	int ret, off, h;
+
+	duprintf("check_compat_entry_size_and_hooks %p\n", e);
+	if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0
+	    || (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
+		duprintf("Bad offset %p, limit = %p\n", e, limit);
+		return -EINVAL;
+	}
+
+	if (e->next_offset < sizeof(struct compat_ipt_entry) +
+			     sizeof(struct compat_xt_entry_target)) {
+		duprintf("checking: element %p size %u\n",
+			 e, e->next_offset);
+		return -EINVAL;
+	}
+
+	/* For purposes of check_entry casting the compat entry is fine */
+	ret = check_entry((struct ipt_entry *)e, name);
+	if (ret)
+		return ret;
+
+	off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
+	entry_offset = (void *)e - (void *)base;
+	j = 0;
+	ret = COMPAT_IPT_MATCH_ITERATE(e, compat_find_calc_match, name,
+				       &e->ip, e->comefrom, &off, &j);
+	if (ret != 0)
+		goto release_matches;
+
+	t = compat_ipt_get_target(e);
+	target = try_then_request_module(xt_find_target(AF_INET,
+							t->u.user.name,
+							t->u.user.revision),
+					 "ipt_%s", t->u.user.name);
+	if (IS_ERR(target) || !target) {
+		duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
+			 t->u.user.name);
+		ret = target ? PTR_ERR(target) : -ENOENT;
+		goto release_matches;
+	}
+	t->u.kernel.target = target;
+
+	off += xt_compat_target_offset(target);
+	*size += off;
+	ret = xt_compat_add_offset(AF_INET, entry_offset, off);
+	if (ret)
+		goto out;
+
+	/* Check hooks & underflows */
+	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
+		if ((unsigned char *)e - base == hook_entries[h])
+			newinfo->hook_entry[h] = hook_entries[h];
+		if ((unsigned char *)e - base == underflows[h])
+			newinfo->underflow[h] = underflows[h];
+	}
+
+	/* Clear counters and comefrom */
+	memset(&e->counters, 0, sizeof(e->counters));
+	e->comefrom = 0;
+
+	(*i)++;
+	return 0;
+
+out:
+	module_put(t->u.kernel.target->me);
+release_matches:
+	IPT_MATCH_ITERATE(e, compat_release_match, &j);
+	return ret;
+}
+
+static int
+compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr,
+			    unsigned int *size, const char *name,
+			    struct xt_table_info *newinfo, unsigned char *base)
+{
+	struct ipt_entry_target *t;
+	struct xt_target *target;
+	struct ipt_entry *de;
+	unsigned int origsize;
+	int ret, h;
+
+	ret = 0;
+	origsize = *size;
+	de = (struct ipt_entry *)*dstptr;
+	memcpy(de, e, sizeof(struct ipt_entry));
+	memcpy(&de->counters, &e->counters, sizeof(e->counters));
+
+	*dstptr += sizeof(struct ipt_entry);
+	*size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry);
+
+	ret = COMPAT_IPT_MATCH_ITERATE(e, xt_compat_match_from_user,
+				       dstptr, size);
+	if (ret)
+		return ret;
+	de->target_offset = e->target_offset - (origsize - *size);
+	t = compat_ipt_get_target(e);
+	target = t->u.kernel.target;
+	xt_compat_target_from_user(t, dstptr, size);
+
+	de->next_offset = e->next_offset - (origsize - *size);
+	for (h = 0; h < NF_INET_NUMHOOKS; h++) {
+		if ((unsigned char *)de - base < newinfo->hook_entry[h])
+			newinfo->hook_entry[h] -= origsize - *size;
+		if ((unsigned char *)de - base < newinfo->underflow[h])
+			newinfo->underflow[h] -= origsize - *size;
+	}
+	return ret;
+}
+
+static int
+compat_check_entry(struct ipt_entry *e, const char *name,
+				     unsigned int *i)
+{
+	struct xt_mtchk_param mtpar;
+	unsigned int j;
+	int ret;
+
+	j = 0;
+	mtpar.table     = name;
+	mtpar.entryinfo = &e->ip;
+	mtpar.hook_mask = e->comefrom;
+	mtpar.family    = NFPROTO_IPV4;
+	ret = IPT_MATCH_ITERATE(e, check_match, &mtpar, &j);
+	if (ret)
+		goto cleanup_matches;
+
+	ret = check_target(e, name);
+	if (ret)
+		goto cleanup_matches;
+
+	(*i)++;
+	return 0;
+
+ cleanup_matches:
+	IPT_MATCH_ITERATE(e, cleanup_match, &j);
+	return ret;
+}
+
+static int
+translate_compat_table(const char *name,
+		       unsigned int valid_hooks,
+		       struct xt_table_info **pinfo,
+		       void **pentry0,
+		       unsigned int total_size,
+		       unsigned int number,
+		       unsigned int *hook_entries,
+		       unsigned int *underflows)
+{
+	unsigned int i, j;
+	struct xt_table_info *newinfo, *info;
+	void *pos, *entry0, *entry1;
+	unsigned int size;
+	int ret;
+
+	info = *pinfo;
+	entry0 = *pentry0;
+	size = total_size;
+	info->number = number;
+
+	/* Init all hooks to impossible value. */
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		info->hook_entry[i] = 0xFFFFFFFF;
+		info->underflow[i] = 0xFFFFFFFF;
+	}
+
+	duprintf("translate_compat_table: size %u\n", info->size);
+	j = 0;
+	xt_compat_lock(AF_INET);
+	/* Walk through entries, checking offsets. */
+	ret = COMPAT_IPT_ENTRY_ITERATE(entry0, total_size,
+				       check_compat_entry_size_and_hooks,
+				       info, &size, entry0,
+				       entry0 + total_size,
+				       hook_entries, underflows, &j, name);
+	if (ret != 0)
+		goto out_unlock;
+
+	ret = -EINVAL;
+	if (j != number) {
+		duprintf("translate_compat_table: %u not %u entries\n",
+			 j, number);
+		goto out_unlock;
+	}
+
+	/* Check hooks all assigned */
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		/* Only hooks which are valid */
+		if (!(valid_hooks & (1 << i)))
+			continue;
+		if (info->hook_entry[i] == 0xFFFFFFFF) {
+			duprintf("Invalid hook entry %u %u\n",
+				 i, hook_entries[i]);
+			goto out_unlock;
+		}
+		if (info->underflow[i] == 0xFFFFFFFF) {
+			duprintf("Invalid underflow %u %u\n",
+				 i, underflows[i]);
+			goto out_unlock;
+		}
+	}
+
+	ret = -ENOMEM;
+	newinfo = xt_alloc_table_info(size);
+	if (!newinfo)
+		goto out_unlock;
+
+	newinfo->number = number;
+	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
+		newinfo->hook_entry[i] = info->hook_entry[i];
+		newinfo->underflow[i] = info->underflow[i];
+	}
+	entry1 = newinfo->entries[raw_smp_processor_id()];
+	pos = entry1;
+	size = total_size;
+	ret = COMPAT_IPT_ENTRY_ITERATE(entry0, total_size,
+				       compat_copy_entry_from_user,
+				       &pos, &size, name, newinfo, entry1);
+	xt_compat_flush_offsets(AF_INET);
+	xt_compat_unlock(AF_INET);
+	if (ret)
+		goto free_newinfo;
+
+	ret = -ELOOP;
+	if (!mark_source_chains(newinfo, valid_hooks, entry1))
+		goto free_newinfo;
+
+	i = 0;
+	ret = IPT_ENTRY_ITERATE(entry1, newinfo->size, compat_check_entry,
+				name, &i);
+	if (ret) {
+		j -= i;
+		COMPAT_IPT_ENTRY_ITERATE_CONTINUE(entry0, newinfo->size, i,
+						  compat_release_entry, &j);
+		IPT_ENTRY_ITERATE(entry1, newinfo->size, cleanup_entry, &i);
+		xt_free_table_info(newinfo);
+		return ret;
+	}
+
+	/* And one copy for every other CPU */
+	for_each_possible_cpu(i)
+		if (newinfo->entries[i] && newinfo->entries[i] != entry1)
+			memcpy(newinfo->entries[i], entry1, newinfo->size);
+
+	*pinfo = newinfo;
+	*pentry0 = entry1;
+	xt_free_table_info(info);
+	return 0;
+
+free_newinfo:
+	xt_free_table_info(newinfo);
+out:
+	COMPAT_IPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
+	return ret;
+out_unlock:
+	xt_compat_flush_offsets(AF_INET);
+	xt_compat_unlock(AF_INET);
+	goto out;
+}
+
+static int
+compat_do_replace(struct net *net, void __user *user, unsigned int len)
+{
+	int ret;
+	struct compat_ipt_replace tmp;
+	struct xt_table_info *newinfo;
+	void *loc_cpu_entry;
+
+	if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
+		return -EFAULT;
+
+	/* overflow check */
+	if (tmp.size >= INT_MAX / num_possible_cpus())
+		return -ENOMEM;
+	if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
+		return -ENOMEM;
+
+	newinfo = xt_alloc_table_info(tmp.size);
+	if (!newinfo)
+		return -ENOMEM;
+
+	/* choose the copy that is on our node/cpu */
+	loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+	if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
+			   tmp.size) != 0) {
+		ret = -EFAULT;
+		goto free_newinfo;
+	}
+
+	ret = translate_compat_table(tmp.name, tmp.valid_hooks,
+				     &newinfo, &loc_cpu_entry, tmp.size,
+				     tmp.num_entries, tmp.hook_entry,
+				     tmp.underflow);
+	if (ret != 0)
+		goto free_newinfo;
+
+	duprintf("compat_do_replace: Translated table\n");
+
+	ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
+			   tmp.num_counters, compat_ptr(tmp.counters));
+	if (ret)
+		goto free_newinfo_untrans;
+	return 0;
+
+ free_newinfo_untrans:
+	IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
+ free_newinfo:
+	xt_free_table_info(newinfo);
+	return ret;
+}
+
+static int
+compat_do_ipt_set_ctl(struct sock *sk,	int cmd, void __user *user,
+		      unsigned int len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case IPT_SO_SET_REPLACE:
+		ret = compat_do_replace(sock_net(sk), user, len);
+		break;
+
+	case IPT_SO_SET_ADD_COUNTERS:
+		ret = do_add_counters(sock_net(sk), user, len, 1);
+		break;
+
+	default:
+		duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+struct compat_ipt_get_entries {
+	char name[IPT_TABLE_MAXNAMELEN];
+	compat_uint_t size;
+	struct compat_ipt_entry entrytable[0];
+};
+
+static int
+compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table,
+			    void __user *userptr)
+{
+	struct xt_counters *counters;
+	const struct xt_table_info *private = table->private;
+	void __user *pos;
+	unsigned int size;
+	int ret = 0;
+	const void *loc_cpu_entry;
+	unsigned int i = 0;
+
+	counters = alloc_counters(table);
+	if (IS_ERR(counters))
+		return PTR_ERR(counters);
+
+	/* choose the copy that is on our node/cpu, ...
+	 * This choice is lazy (because current thread is
+	 * allowed to migrate to another cpu)
+	 */
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	pos = userptr;
+	size = total_size;
+	ret = IPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
+				compat_copy_entry_to_user,
+				&pos, &size, counters, &i);
+
+	vfree(counters);
+	return ret;
+}
+
+static int
+compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
+		   int *len)
+{
+	int ret;
+	struct compat_ipt_get_entries get;
+	struct xt_table *t;
+
+	if (*len < sizeof(get)) {
+		duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&get, uptr, sizeof(get)) != 0)
+		return -EFAULT;
+
+	if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
+		duprintf("compat_get_entries: %u != %zu\n",
+			 *len, sizeof(get) + get.size);
+		return -EINVAL;
+	}
+
+	xt_compat_lock(AF_INET);
+	t = xt_find_table_lock(net, AF_INET, get.name);
+	if (t && !IS_ERR(t)) {
+		const struct xt_table_info *private = t->private;
+		struct xt_table_info info;
+		duprintf("t->private->number = %u\n", private->number);
+		ret = compat_table_info(private, &info);
+		if (!ret && get.size == info.size) {
+			ret = compat_copy_entries_to_user(private->size,
+							  t, uptr->entrytable);
+		} else if (!ret) {
+			duprintf("compat_get_entries: I've got %u not %u!\n",
+				 private->size, get.size);
+			ret = -EAGAIN;
+		}
+		xt_compat_flush_offsets(AF_INET);
+		module_put(t->me);
+		xt_table_unlock(t);
+	} else
+		ret = t ? PTR_ERR(t) : -ENOENT;
+
+	xt_compat_unlock(AF_INET);
+	return ret;
+}
+
+static int do_ipt_get_ctl(struct sock *, int, void __user *, int *);
+
+static int
+compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case IPT_SO_GET_INFO:
+		ret = get_info(sock_net(sk), user, len, 1);
+		break;
+	case IPT_SO_GET_ENTRIES:
+		ret = compat_get_entries(sock_net(sk), user, len);
+		break;
+	default:
+		ret = do_ipt_get_ctl(sk, cmd, user, len);
+	}
+	return ret;
+}
+#endif
+
+static int
+do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case IPT_SO_SET_REPLACE:
+		ret = do_replace(sock_net(sk), user, len);
+		break;
+
+	case IPT_SO_SET_ADD_COUNTERS:
+		ret = do_add_counters(sock_net(sk), user, len, 0);
+		break;
+
+	default:
+		duprintf("do_ipt_set_ctl:  unknown request %i\n", cmd);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int
+do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
+{
+	int ret;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	switch (cmd) {
+	case IPT_SO_GET_INFO:
+		ret = get_info(sock_net(sk), user, len, 0);
+		break;
+
+	case IPT_SO_GET_ENTRIES:
+		ret = get_entries(sock_net(sk), user, len);
+		break;
+
+	case IPT_SO_GET_REVISION_MATCH:
+	case IPT_SO_GET_REVISION_TARGET: {
+		struct ipt_get_revision rev;
+		int target;
+
+		if (*len != sizeof(rev)) {
+			ret = -EINVAL;
+			break;
+		}
+		if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
+			ret = -EFAULT;
+			break;
+		}
+
+		if (cmd == IPT_SO_GET_REVISION_TARGET)
+			target = 1;
+		else
+			target = 0;
+
+		try_then_request_module(xt_find_revision(AF_INET, rev.name,
+							 rev.revision,
+							 target, &ret),
+					"ipt_%s", rev.name);
+		break;
+	}
+
+	default:
+		duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+struct xt_table *ipt_register_table(struct net *net, struct xt_table *table,
+				    const struct ipt_replace *repl)
+{
+	int ret;
+	struct xt_table_info *newinfo;
+	struct xt_table_info bootstrap
+		= { 0, 0, 0, { 0 }, { 0 }, { } };
+	void *loc_cpu_entry;
+	struct xt_table *new_table;
+
+	newinfo = xt_alloc_table_info(repl->size);
+	if (!newinfo) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* choose the copy on our node/cpu, but dont care about preemption */
+	loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
+	memcpy(loc_cpu_entry, repl->entries, repl->size);
+
+	ret = translate_table(table->name, table->valid_hooks,
+			      newinfo, loc_cpu_entry, repl->size,
+			      repl->num_entries,
+			      repl->hook_entry,
+			      repl->underflow);
+	if (ret != 0)
+		goto out_free;
+
+	new_table = xt_register_table(net, table, &bootstrap, newinfo);
+	if (IS_ERR(new_table)) {
+		ret = PTR_ERR(new_table);
+		goto out_free;
+	}
+
+	return new_table;
+
+out_free:
+	xt_free_table_info(newinfo);
+out:
+	return ERR_PTR(ret);
+}
+
+void ipt_unregister_table(struct xt_table *table)
+{
+	struct xt_table_info *private;
+	void *loc_cpu_entry;
+	struct module *table_owner = table->me;
+
+	private = xt_unregister_table(table);
+
+	/* Decrease module usage counts and free resources */
+	loc_cpu_entry = private->entries[raw_smp_processor_id()];
+	IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
+	if (private->number > private->initial_entries)
+		module_put(table_owner);
+	xt_free_table_info(private);
+}
+
+/* Returns 1 if the type and code is matched by the range, 0 otherwise */
+static inline bool
+icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
+		     u_int8_t type, u_int8_t code,
+		     bool invert)
+{
+	return ((test_type == 0xFF) ||
+		(type == test_type && code >= min_code && code <= max_code))
+		^ invert;
+}
+
+static bool
+icmp_match(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+	const struct icmphdr *ic;
+	struct icmphdr _icmph;
+	const struct ipt_icmp *icmpinfo = par->matchinfo;
+
+	/* Must not be a fragment. */
+	if (par->fragoff != 0)
+		return false;
+
+	ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph);
+	if (ic == NULL) {
+		/* We've been asked to examine this packet, and we
+		 * can't.  Hence, no choice but to drop.
+		 */
+		duprintf("Dropping evil ICMP tinygram.\n");
+		*par->hotdrop = true;
+		return false;
+	}
+
+	return icmp_type_code_match(icmpinfo->type,
+				    icmpinfo->code[0],
+				    icmpinfo->code[1],
+				    ic->type, ic->code,
+				    !!(icmpinfo->invflags&IPT_ICMP_INV));
+}
+
+static bool icmp_checkentry(const struct xt_mtchk_param *par)
+{
+	const struct ipt_icmp *icmpinfo = par->matchinfo;
+
+	/* Must specify no unknown invflags */
+	return !(icmpinfo->invflags & ~IPT_ICMP_INV);
+}
+
+/* The built-in targets: standard (NULL) and error. */
+static struct xt_target ipt_standard_target __read_mostly = {
+	.name		= IPT_STANDARD_TARGET,
+	.targetsize	= sizeof(int),
+	.family		= AF_INET,
+#ifdef CONFIG_COMPAT
+	.compatsize	= sizeof(compat_int_t),
+	.compat_from_user = compat_standard_from_user,
+	.compat_to_user	= compat_standard_to_user,
+#endif
+};
+
+static struct xt_target ipt_error_target __read_mostly = {
+	.name		= IPT_ERROR_TARGET,
+	.target		= ipt_error,
+	.targetsize	= IPT_FUNCTION_MAXNAMELEN,
+	.family		= AF_INET,
+};
+
+static struct nf_sockopt_ops ipt_sockopts = {
+	.pf		= PF_INET,
+	.set_optmin	= IPT_BASE_CTL,
+	.set_optmax	= IPT_SO_SET_MAX+1,
+	.set		= do_ipt_set_ctl,
+#ifdef CONFIG_COMPAT
+	.compat_set	= compat_do_ipt_set_ctl,
+#endif
+	.get_optmin	= IPT_BASE_CTL,
+	.get_optmax	= IPT_SO_GET_MAX+1,
+	.get		= do_ipt_get_ctl,
+#ifdef CONFIG_COMPAT
+	.compat_get	= compat_do_ipt_get_ctl,
+#endif
+	.owner		= THIS_MODULE,
+};
+
+static struct xt_match icmp_matchstruct __read_mostly = {
+	.name		= "icmp",
+	.match		= icmp_match,
+	.matchsize	= sizeof(struct ipt_icmp),
+	.checkentry	= icmp_checkentry,
+	.proto		= IPPROTO_ICMP,
+	.family		= AF_INET,
+};
+
+static int __net_init ip_tables_net_init(struct net *net)
+{
+	return xt_proto_init(net, AF_INET);
+}
+
+static void __net_exit ip_tables_net_exit(struct net *net)
+{
+	xt_proto_fini(net, AF_INET);
+}
+
+static struct pernet_operations ip_tables_net_ops = {
+	.init = ip_tables_net_init,
+	.exit = ip_tables_net_exit,
+};
+
+static int __init ip_tables_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&ip_tables_net_ops);
+	if (ret < 0)
+		goto err1;
+
+	/* Noone else will be downing sem now, so we won't sleep */
+	ret = xt_register_target(&ipt_standard_target);
+	if (ret < 0)
+		goto err2;
+	ret = xt_register_target(&ipt_error_target);
+	if (ret < 0)
+		goto err3;
+	ret = xt_register_match(&icmp_matchstruct);
+	if (ret < 0)
+		goto err4;
+
+	/* Register setsockopt */
+	ret = nf_register_sockopt(&ipt_sockopts);
+	if (ret < 0)
+		goto err5;
+
+	printk(KERN_INFO "ip_tables: (C) 2000-2006 Netfilter Core Team\n");
+	return 0;
+
+err5:
+	xt_unregister_match(&icmp_matchstruct);
+err4:
+	xt_unregister_target(&ipt_error_target);
+err3:
+	xt_unregister_target(&ipt_standard_target);
+err2:
+	unregister_pernet_subsys(&ip_tables_net_ops);
+err1:
+	return ret;
+}
+
+static void __exit ip_tables_fini(void)
+{
+	nf_unregister_sockopt(&ipt_sockopts);
+
+	xt_unregister_match(&icmp_matchstruct);
+	xt_unregister_target(&ipt_error_target);
+	xt_unregister_target(&ipt_standard_target);
+
+	unregister_pernet_subsys(&ip_tables_net_ops);
+}
+
+EXPORT_SYMBOL(ipt_register_table);
+EXPORT_SYMBOL(ipt_unregister_table);
+EXPORT_SYMBOL(ipt_do_table);
+module_init(ip_tables_init);
+module_exit(ip_tables_fini);
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
new file mode 100644
index 0000000..7ac1677
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -0,0 +1,744 @@
+/* Cluster IP hashmark target
+ * (C) 2003-2004 by Harald Welte <laforge@netfilter.org>
+ * based on ideas of Fabio Olive Leite <olive@unixforge.org>
+ *
+ * Development of this code funded by SuSE Linux AG, http://www.suse.com/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/jhash.h>
+#include <linux/bitops.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/icmp.h>
+#include <linux/if_arp.h>
+#include <linux/seq_file.h>
+#include <linux/netfilter_arp.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_CLUSTERIP.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/net_namespace.h>
+#include <net/checksum.h>
+
+#define CLUSTERIP_VERSION "0.8"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: CLUSTERIP target");
+
+struct clusterip_config {
+	struct list_head list;			/* list of all configs */
+	atomic_t refcount;			/* reference count */
+	atomic_t entries;			/* number of entries/rules
+						 * referencing us */
+
+	__be32 clusterip;			/* the IP address */
+	u_int8_t clustermac[ETH_ALEN];		/* the MAC address */
+	struct net_device *dev;			/* device */
+	u_int16_t num_total_nodes;		/* total number of nodes */
+	unsigned long local_nodes;		/* node number array */
+
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *pde;		/* proc dir entry */
+#endif
+	enum clusterip_hashmode hash_mode;	/* which hashing mode */
+	u_int32_t hash_initval;			/* hash initialization */
+};
+
+static LIST_HEAD(clusterip_configs);
+
+/* clusterip_lock protects the clusterip_configs list */
+static DEFINE_RWLOCK(clusterip_lock);
+
+#ifdef CONFIG_PROC_FS
+static const struct file_operations clusterip_proc_fops;
+static struct proc_dir_entry *clusterip_procdir;
+#endif
+
+static inline void
+clusterip_config_get(struct clusterip_config *c)
+{
+	atomic_inc(&c->refcount);
+}
+
+static inline void
+clusterip_config_put(struct clusterip_config *c)
+{
+	if (atomic_dec_and_test(&c->refcount))
+		kfree(c);
+}
+
+/* decrease the count of entries using/referencing this config.  If last
+ * entry(rule) is removed, remove the config from lists, but don't free it
+ * yet, since proc-files could still be holding references */
+static inline void
+clusterip_config_entry_put(struct clusterip_config *c)
+{
+	write_lock_bh(&clusterip_lock);
+	if (atomic_dec_and_test(&c->entries)) {
+		list_del(&c->list);
+		write_unlock_bh(&clusterip_lock);
+
+		dev_mc_delete(c->dev, c->clustermac, ETH_ALEN, 0);
+		dev_put(c->dev);
+
+		/* In case anyone still accesses the file, the open/close
+		 * functions are also incrementing the refcount on their own,
+		 * so it's safe to remove the entry even if it's in use. */
+#ifdef CONFIG_PROC_FS
+		remove_proc_entry(c->pde->name, c->pde->parent);
+#endif
+		return;
+	}
+	write_unlock_bh(&clusterip_lock);
+}
+
+static struct clusterip_config *
+__clusterip_config_find(__be32 clusterip)
+{
+	struct clusterip_config *c;
+
+	list_for_each_entry(c, &clusterip_configs, list) {
+		if (c->clusterip == clusterip)
+			return c;
+	}
+
+	return NULL;
+}
+
+static inline struct clusterip_config *
+clusterip_config_find_get(__be32 clusterip, int entry)
+{
+	struct clusterip_config *c;
+
+	read_lock_bh(&clusterip_lock);
+	c = __clusterip_config_find(clusterip);
+	if (!c) {
+		read_unlock_bh(&clusterip_lock);
+		return NULL;
+	}
+	atomic_inc(&c->refcount);
+	if (entry)
+		atomic_inc(&c->entries);
+	read_unlock_bh(&clusterip_lock);
+
+	return c;
+}
+
+static void
+clusterip_config_init_nodelist(struct clusterip_config *c,
+			       const struct ipt_clusterip_tgt_info *i)
+{
+	int n;
+
+	for (n = 0; n < i->num_local_nodes; n++)
+		set_bit(i->local_nodes[n] - 1, &c->local_nodes);
+}
+
+static struct clusterip_config *
+clusterip_config_init(const struct ipt_clusterip_tgt_info *i, __be32 ip,
+			struct net_device *dev)
+{
+	struct clusterip_config *c;
+
+	c = kzalloc(sizeof(*c), GFP_ATOMIC);
+	if (!c)
+		return NULL;
+
+	c->dev = dev;
+	c->clusterip = ip;
+	memcpy(&c->clustermac, &i->clustermac, ETH_ALEN);
+	c->num_total_nodes = i->num_total_nodes;
+	clusterip_config_init_nodelist(c, i);
+	c->hash_mode = i->hash_mode;
+	c->hash_initval = i->hash_initval;
+	atomic_set(&c->refcount, 1);
+	atomic_set(&c->entries, 1);
+
+#ifdef CONFIG_PROC_FS
+	{
+		char buffer[16];
+
+		/* create proc dir entry */
+		sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip));
+		c->pde = proc_create_data(buffer, S_IWUSR|S_IRUSR,
+					  clusterip_procdir,
+					  &clusterip_proc_fops, c);
+		if (!c->pde) {
+			kfree(c);
+			return NULL;
+		}
+	}
+#endif
+
+	write_lock_bh(&clusterip_lock);
+	list_add(&c->list, &clusterip_configs);
+	write_unlock_bh(&clusterip_lock);
+
+	return c;
+}
+
+#ifdef CONFIG_PROC_FS
+static int
+clusterip_add_node(struct clusterip_config *c, u_int16_t nodenum)
+{
+
+	if (nodenum == 0 ||
+	    nodenum > c->num_total_nodes)
+		return 1;
+
+	/* check if we already have this number in our bitfield */
+	if (test_and_set_bit(nodenum - 1, &c->local_nodes))
+		return 1;
+
+	return 0;
+}
+
+static bool
+clusterip_del_node(struct clusterip_config *c, u_int16_t nodenum)
+{
+	if (nodenum == 0 ||
+	    nodenum > c->num_total_nodes)
+		return true;
+
+	if (test_and_clear_bit(nodenum - 1, &c->local_nodes))
+		return false;
+
+	return true;
+}
+#endif
+
+static inline u_int32_t
+clusterip_hashfn(const struct sk_buff *skb,
+		 const struct clusterip_config *config)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	unsigned long hashval;
+	u_int16_t sport, dport;
+	const u_int16_t *ports;
+
+	switch (iph->protocol) {
+	case IPPROTO_TCP:
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE:
+	case IPPROTO_SCTP:
+	case IPPROTO_DCCP:
+	case IPPROTO_ICMP:
+		ports = (const void *)iph+iph->ihl*4;
+		sport = ports[0];
+		dport = ports[1];
+		break;
+	default:
+		if (net_ratelimit())
+			printk(KERN_NOTICE "CLUSTERIP: unknown protocol `%u'\n",
+				iph->protocol);
+		sport = dport = 0;
+	}
+
+	switch (config->hash_mode) {
+	case CLUSTERIP_HASHMODE_SIP:
+		hashval = jhash_1word(ntohl(iph->saddr),
+				      config->hash_initval);
+		break;
+	case CLUSTERIP_HASHMODE_SIP_SPT:
+		hashval = jhash_2words(ntohl(iph->saddr), sport,
+				       config->hash_initval);
+		break;
+	case CLUSTERIP_HASHMODE_SIP_SPT_DPT:
+		hashval = jhash_3words(ntohl(iph->saddr), sport, dport,
+				       config->hash_initval);
+		break;
+	default:
+		/* to make gcc happy */
+		hashval = 0;
+		/* This cannot happen, unless the check function wasn't called
+		 * at rule load time */
+		printk("CLUSTERIP: unknown mode `%u'\n", config->hash_mode);
+		BUG();
+		break;
+	}
+
+	/* node numbers are 1..n, not 0..n */
+	return (((u64)hashval * config->num_total_nodes) >> 32) + 1;
+}
+
+static inline int
+clusterip_responsible(const struct clusterip_config *config, u_int32_t hash)
+{
+	return test_bit(hash - 1, &config->local_nodes);
+}
+
+/***********************************************************************
+ * IPTABLES TARGET
+ ***********************************************************************/
+
+static unsigned int
+clusterip_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	u_int32_t hash;
+
+	/* don't need to clusterip_config_get() here, since refcount
+	 * is only decremented by destroy() - and ip_tables guarantees
+	 * that the ->target() function isn't called after ->destroy() */
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct == NULL) {
+		printk(KERN_ERR "CLUSTERIP: no conntrack!\n");
+			/* FIXME: need to drop invalid ones, since replies
+			 * to outgoing connections of other nodes will be
+			 * marked as INVALID */
+		return NF_DROP;
+	}
+
+	/* special case: ICMP error handling. conntrack distinguishes between
+	 * error messages (RELATED) and information requests (see below) */
+	if (ip_hdr(skb)->protocol == IPPROTO_ICMP
+	    && (ctinfo == IP_CT_RELATED
+		|| ctinfo == IP_CT_RELATED+IP_CT_IS_REPLY))
+		return XT_CONTINUE;
+
+	/* ip_conntrack_icmp guarantees us that we only have ICMP_ECHO,
+	 * TIMESTAMP, INFO_REQUEST or ADDRESS type icmp packets from here
+	 * on, which all have an ID field [relevant for hashing]. */
+
+	hash = clusterip_hashfn(skb, cipinfo->config);
+
+	switch (ctinfo) {
+		case IP_CT_NEW:
+			ct->mark = hash;
+			break;
+		case IP_CT_RELATED:
+		case IP_CT_RELATED+IP_CT_IS_REPLY:
+			/* FIXME: we don't handle expectations at the
+			 * moment.  they can arrive on a different node than
+			 * the master connection (e.g. FTP passive mode) */
+		case IP_CT_ESTABLISHED:
+		case IP_CT_ESTABLISHED+IP_CT_IS_REPLY:
+			break;
+		default:
+			break;
+	}
+
+#ifdef DEBUG
+	nf_ct_dump_tuple_ip(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+#endif
+	pr_debug("hash=%u ct_hash=%u ", hash, ct->mark);
+	if (!clusterip_responsible(cipinfo->config, hash)) {
+		pr_debug("not responsible\n");
+		return NF_DROP;
+	}
+	pr_debug("responsible\n");
+
+	/* despite being received via linklayer multicast, this is
+	 * actually a unicast IP packet. TCP doesn't like PACKET_MULTICAST */
+	skb->pkt_type = PACKET_HOST;
+
+	return XT_CONTINUE;
+}
+
+static bool clusterip_tg_check(const struct xt_tgchk_param *par)
+{
+	struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
+	const struct ipt_entry *e = par->entryinfo;
+
+	struct clusterip_config *config;
+
+	if (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP &&
+	    cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT &&
+	    cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT_DPT) {
+		printk(KERN_WARNING "CLUSTERIP: unknown mode `%u'\n",
+			cipinfo->hash_mode);
+		return false;
+
+	}
+	if (e->ip.dmsk.s_addr != htonl(0xffffffff)
+	    || e->ip.dst.s_addr == 0) {
+		printk(KERN_ERR "CLUSTERIP: Please specify destination IP\n");
+		return false;
+	}
+
+	/* FIXME: further sanity checks */
+
+	config = clusterip_config_find_get(e->ip.dst.s_addr, 1);
+	if (!config) {
+		if (!(cipinfo->flags & CLUSTERIP_FLAG_NEW)) {
+			printk(KERN_WARNING "CLUSTERIP: no config found for %u.%u.%u.%u, need 'new'\n", NIPQUAD(e->ip.dst.s_addr));
+			return false;
+		} else {
+			struct net_device *dev;
+
+			if (e->ip.iniface[0] == '\0') {
+				printk(KERN_WARNING "CLUSTERIP: Please specify an interface name\n");
+				return false;
+			}
+
+			dev = dev_get_by_name(&init_net, e->ip.iniface);
+			if (!dev) {
+				printk(KERN_WARNING "CLUSTERIP: no such interface %s\n", e->ip.iniface);
+				return false;
+			}
+
+			config = clusterip_config_init(cipinfo,
+							e->ip.dst.s_addr, dev);
+			if (!config) {
+				printk(KERN_WARNING "CLUSTERIP: cannot allocate config\n");
+				dev_put(dev);
+				return false;
+			}
+			dev_mc_add(config->dev,config->clustermac, ETH_ALEN, 0);
+		}
+	}
+	cipinfo->config = config;
+
+	if (nf_ct_l3proto_try_module_get(par->target->family) < 0) {
+		printk(KERN_WARNING "can't load conntrack support for "
+				    "proto=%u\n", par->target->family);
+		return false;
+	}
+
+	return true;
+}
+
+/* drop reference count of cluster config when rule is deleted */
+static void clusterip_tg_destroy(const struct xt_tgdtor_param *par)
+{
+	const struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
+
+	/* if no more entries are referencing the config, remove it
+	 * from the list and destroy the proc entry */
+	clusterip_config_entry_put(cipinfo->config);
+
+	clusterip_config_put(cipinfo->config);
+
+	nf_ct_l3proto_module_put(par->target->family);
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_ipt_clusterip_tgt_info
+{
+	u_int32_t	flags;
+	u_int8_t	clustermac[6];
+	u_int16_t	num_total_nodes;
+	u_int16_t	num_local_nodes;
+	u_int16_t	local_nodes[CLUSTERIP_MAX_NODES];
+	u_int32_t	hash_mode;
+	u_int32_t	hash_initval;
+	compat_uptr_t	config;
+};
+#endif /* CONFIG_COMPAT */
+
+static struct xt_target clusterip_tg_reg __read_mostly = {
+	.name		= "CLUSTERIP",
+	.family		= NFPROTO_IPV4,
+	.target		= clusterip_tg,
+	.checkentry	= clusterip_tg_check,
+	.destroy	= clusterip_tg_destroy,
+	.targetsize	= sizeof(struct ipt_clusterip_tgt_info),
+#ifdef CONFIG_COMPAT
+	.compatsize	= sizeof(struct compat_ipt_clusterip_tgt_info),
+#endif /* CONFIG_COMPAT */
+	.me		= THIS_MODULE
+};
+
+
+/***********************************************************************
+ * ARP MANGLING CODE
+ ***********************************************************************/
+
+/* hardcoded for 48bit ethernet and 32bit ipv4 addresses */
+struct arp_payload {
+	u_int8_t src_hw[ETH_ALEN];
+	__be32 src_ip;
+	u_int8_t dst_hw[ETH_ALEN];
+	__be32 dst_ip;
+} __attribute__ ((packed));
+
+#ifdef DEBUG
+static void arp_print(struct arp_payload *payload)
+{
+#define HBUFFERLEN 30
+	char hbuffer[HBUFFERLEN];
+	int j,k;
+
+	for (k=0, j=0; k < HBUFFERLEN-3 && j < ETH_ALEN; j++) {
+		hbuffer[k++] = hex_asc_hi(payload->src_hw[j]);
+		hbuffer[k++] = hex_asc_lo(payload->src_hw[j]);
+		hbuffer[k++]=':';
+	}
+	hbuffer[--k]='\0';
+
+	printk("src %u.%u.%u.%u@%s, dst %u.%u.%u.%u\n",
+		NIPQUAD(payload->src_ip), hbuffer,
+		NIPQUAD(payload->dst_ip));
+}
+#endif
+
+static unsigned int
+arp_mangle(unsigned int hook,
+	   struct sk_buff *skb,
+	   const struct net_device *in,
+	   const struct net_device *out,
+	   int (*okfn)(struct sk_buff *))
+{
+	struct arphdr *arp = arp_hdr(skb);
+	struct arp_payload *payload;
+	struct clusterip_config *c;
+
+	/* we don't care about non-ethernet and non-ipv4 ARP */
+	if (arp->ar_hrd != htons(ARPHRD_ETHER)
+	    || arp->ar_pro != htons(ETH_P_IP)
+	    || arp->ar_pln != 4 || arp->ar_hln != ETH_ALEN)
+		return NF_ACCEPT;
+
+	/* we only want to mangle arp requests and replies */
+	if (arp->ar_op != htons(ARPOP_REPLY)
+	    && arp->ar_op != htons(ARPOP_REQUEST))
+		return NF_ACCEPT;
+
+	payload = (void *)(arp+1);
+
+	/* if there is no clusterip configuration for the arp reply's
+	 * source ip, we don't want to mangle it */
+	c = clusterip_config_find_get(payload->src_ip, 0);
+	if (!c)
+		return NF_ACCEPT;
+
+	/* normally the linux kernel always replies to arp queries of
+	 * addresses on different interfacs.  However, in the CLUSTERIP case
+	 * this wouldn't work, since we didn't subscribe the mcast group on
+	 * other interfaces */
+	if (c->dev != out) {
+		pr_debug("CLUSTERIP: not mangling arp reply on different "
+			 "interface: cip'%s'-skb'%s'\n",
+			 c->dev->name, out->name);
+		clusterip_config_put(c);
+		return NF_ACCEPT;
+	}
+
+	/* mangle reply hardware address */
+	memcpy(payload->src_hw, c->clustermac, arp->ar_hln);
+
+#ifdef DEBUG
+	pr_debug(KERN_DEBUG "CLUSTERIP mangled arp reply: ");
+	arp_print(payload);
+#endif
+
+	clusterip_config_put(c);
+
+	return NF_ACCEPT;
+}
+
+static struct nf_hook_ops cip_arp_ops __read_mostly = {
+	.hook = arp_mangle,
+	.pf = NFPROTO_ARP,
+	.hooknum = NF_ARP_OUT,
+	.priority = -1
+};
+
+/***********************************************************************
+ * PROC DIR HANDLING
+ ***********************************************************************/
+
+#ifdef CONFIG_PROC_FS
+
+struct clusterip_seq_position {
+	unsigned int pos;	/* position */
+	unsigned int weight;	/* number of bits set == size */
+	unsigned int bit;	/* current bit */
+	unsigned long val;	/* current value */
+};
+
+static void *clusterip_seq_start(struct seq_file *s, loff_t *pos)
+{
+	const struct proc_dir_entry *pde = s->private;
+	struct clusterip_config *c = pde->data;
+	unsigned int weight;
+	u_int32_t local_nodes;
+	struct clusterip_seq_position *idx;
+
+	/* FIXME: possible race */
+	local_nodes = c->local_nodes;
+	weight = hweight32(local_nodes);
+	if (*pos >= weight)
+		return NULL;
+
+	idx = kmalloc(sizeof(struct clusterip_seq_position), GFP_KERNEL);
+	if (!idx)
+		return ERR_PTR(-ENOMEM);
+
+	idx->pos = *pos;
+	idx->weight = weight;
+	idx->bit = ffs(local_nodes);
+	idx->val = local_nodes;
+	clear_bit(idx->bit - 1, &idx->val);
+
+	return idx;
+}
+
+static void *clusterip_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct clusterip_seq_position *idx = v;
+
+	*pos = ++idx->pos;
+	if (*pos >= idx->weight) {
+		kfree(v);
+		return NULL;
+	}
+	idx->bit = ffs(idx->val);
+	clear_bit(idx->bit - 1, &idx->val);
+	return idx;
+}
+
+static void clusterip_seq_stop(struct seq_file *s, void *v)
+{
+	kfree(v);
+}
+
+static int clusterip_seq_show(struct seq_file *s, void *v)
+{
+	struct clusterip_seq_position *idx = v;
+
+	if (idx->pos != 0)
+		seq_putc(s, ',');
+
+	seq_printf(s, "%u", idx->bit);
+
+	if (idx->pos == idx->weight - 1)
+		seq_putc(s, '\n');
+
+	return 0;
+}
+
+static const struct seq_operations clusterip_seq_ops = {
+	.start	= clusterip_seq_start,
+	.next	= clusterip_seq_next,
+	.stop	= clusterip_seq_stop,
+	.show	= clusterip_seq_show,
+};
+
+static int clusterip_proc_open(struct inode *inode, struct file *file)
+{
+	int ret = seq_open(file, &clusterip_seq_ops);
+
+	if (!ret) {
+		struct seq_file *sf = file->private_data;
+		struct proc_dir_entry *pde = PDE(inode);
+		struct clusterip_config *c = pde->data;
+
+		sf->private = pde;
+
+		clusterip_config_get(c);
+	}
+
+	return ret;
+}
+
+static int clusterip_proc_release(struct inode *inode, struct file *file)
+{
+	struct proc_dir_entry *pde = PDE(inode);
+	struct clusterip_config *c = pde->data;
+	int ret;
+
+	ret = seq_release(inode, file);
+
+	if (!ret)
+		clusterip_config_put(c);
+
+	return ret;
+}
+
+static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
+				size_t size, loff_t *ofs)
+{
+#define PROC_WRITELEN	10
+	char buffer[PROC_WRITELEN+1];
+	const struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
+	struct clusterip_config *c = pde->data;
+	unsigned long nodenum;
+
+	if (copy_from_user(buffer, input, PROC_WRITELEN))
+		return -EFAULT;
+
+	if (*buffer == '+') {
+		nodenum = simple_strtoul(buffer+1, NULL, 10);
+		if (clusterip_add_node(c, nodenum))
+			return -ENOMEM;
+	} else if (*buffer == '-') {
+		nodenum = simple_strtoul(buffer+1, NULL,10);
+		if (clusterip_del_node(c, nodenum))
+			return -ENOENT;
+	} else
+		return -EIO;
+
+	return size;
+}
+
+static const struct file_operations clusterip_proc_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = clusterip_proc_open,
+	.read	 = seq_read,
+	.write	 = clusterip_proc_write,
+	.llseek	 = seq_lseek,
+	.release = clusterip_proc_release,
+};
+
+#endif /* CONFIG_PROC_FS */
+
+static int __init clusterip_tg_init(void)
+{
+	int ret;
+
+	ret = xt_register_target(&clusterip_tg_reg);
+	if (ret < 0)
+		return ret;
+
+	ret = nf_register_hook(&cip_arp_ops);
+	if (ret < 0)
+		goto cleanup_target;
+
+#ifdef CONFIG_PROC_FS
+	clusterip_procdir = proc_mkdir("ipt_CLUSTERIP", init_net.proc_net);
+	if (!clusterip_procdir) {
+		printk(KERN_ERR "CLUSTERIP: Unable to proc dir entry\n");
+		ret = -ENOMEM;
+		goto cleanup_hook;
+	}
+#endif /* CONFIG_PROC_FS */
+
+	printk(KERN_NOTICE "ClusterIP Version %s loaded successfully\n",
+		CLUSTERIP_VERSION);
+	return 0;
+
+#ifdef CONFIG_PROC_FS
+cleanup_hook:
+	nf_unregister_hook(&cip_arp_ops);
+#endif /* CONFIG_PROC_FS */
+cleanup_target:
+	xt_unregister_target(&clusterip_tg_reg);
+	return ret;
+}
+
+static void __exit clusterip_tg_exit(void)
+{
+	printk(KERN_NOTICE "ClusterIP Version %s unloading\n",
+		CLUSTERIP_VERSION);
+#ifdef CONFIG_PROC_FS
+	remove_proc_entry(clusterip_procdir->name, clusterip_procdir->parent);
+#endif
+	nf_unregister_hook(&cip_arp_ops);
+	xt_unregister_target(&clusterip_tg_reg);
+}
+
+module_init(clusterip_tg_init);
+module_exit(clusterip_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
new file mode 100644
index 0000000..f7e2fa0
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -0,0 +1,141 @@
+/* iptables module for the IPv4 and TCP ECN bits, Version 1.5
+ *
+ * (C) 2002 by Harald Welte <laforge@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/in.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+#include <linux/tcp.h>
+#include <net/checksum.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ECN.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag modification");
+
+/* set ECT codepoint from IP header.
+ * 	return false if there was an error. */
+static inline bool
+set_ect_ip(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
+		__u8 oldtos;
+		if (!skb_make_writable(skb, sizeof(struct iphdr)))
+			return false;
+		iph = ip_hdr(skb);
+		oldtos = iph->tos;
+		iph->tos &= ~IPT_ECN_IP_MASK;
+		iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
+		csum_replace2(&iph->check, htons(oldtos), htons(iph->tos));
+	}
+	return true;
+}
+
+/* Return false if there was an error. */
+static inline bool
+set_ect_tcp(struct sk_buff *skb, const struct ipt_ECN_info *einfo)
+{
+	struct tcphdr _tcph, *tcph;
+	__be16 oldval;
+
+	/* Not enought header? */
+	tcph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
+	if (!tcph)
+		return false;
+
+	if ((!(einfo->operation & IPT_ECN_OP_SET_ECE) ||
+	     tcph->ece == einfo->proto.tcp.ece) &&
+	    (!(einfo->operation & IPT_ECN_OP_SET_CWR) ||
+	     tcph->cwr == einfo->proto.tcp.cwr))
+		return true;
+
+	if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph)))
+		return false;
+	tcph = (void *)ip_hdr(skb) + ip_hdrlen(skb);
+
+	oldval = ((__be16 *)tcph)[6];
+	if (einfo->operation & IPT_ECN_OP_SET_ECE)
+		tcph->ece = einfo->proto.tcp.ece;
+	if (einfo->operation & IPT_ECN_OP_SET_CWR)
+		tcph->cwr = einfo->proto.tcp.cwr;
+
+	inet_proto_csum_replace2(&tcph->check, skb,
+				 oldval, ((__be16 *)tcph)[6], 0);
+	return true;
+}
+
+static unsigned int
+ecn_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	const struct ipt_ECN_info *einfo = par->targinfo;
+
+	if (einfo->operation & IPT_ECN_OP_SET_IP)
+		if (!set_ect_ip(skb, einfo))
+			return NF_DROP;
+
+	if (einfo->operation & (IPT_ECN_OP_SET_ECE | IPT_ECN_OP_SET_CWR)
+	    && ip_hdr(skb)->protocol == IPPROTO_TCP)
+		if (!set_ect_tcp(skb, einfo))
+			return NF_DROP;
+
+	return XT_CONTINUE;
+}
+
+static bool ecn_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct ipt_ECN_info *einfo = par->targinfo;
+	const struct ipt_entry *e = par->entryinfo;
+
+	if (einfo->operation & IPT_ECN_OP_MASK) {
+		printk(KERN_WARNING "ECN: unsupported ECN operation %x\n",
+			einfo->operation);
+		return false;
+	}
+	if (einfo->ip_ect & ~IPT_ECN_IP_MASK) {
+		printk(KERN_WARNING "ECN: new ECT codepoint %x out of mask\n",
+			einfo->ip_ect);
+		return false;
+	}
+	if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR))
+	    && (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & XT_INV_PROTO))) {
+		printk(KERN_WARNING "ECN: cannot use TCP operations on a "
+		       "non-tcp rule\n");
+		return false;
+	}
+	return true;
+}
+
+static struct xt_target ecn_tg_reg __read_mostly = {
+	.name		= "ECN",
+	.family		= NFPROTO_IPV4,
+	.target		= ecn_tg,
+	.targetsize	= sizeof(struct ipt_ECN_info),
+	.table		= "mangle",
+	.checkentry	= ecn_tg_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init ecn_tg_init(void)
+{
+	return xt_register_target(&ecn_tg_reg);
+}
+
+static void __exit ecn_tg_exit(void)
+{
+	xt_unregister_target(&ecn_tg_reg);
+}
+
+module_init(ecn_tg_init);
+module_exit(ecn_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_LOG.c b/net/ipv4/netfilter/ipt_LOG.c
new file mode 100644
index 0000000..fc6ce04
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_LOG.c
@@ -0,0 +1,492 @@
+/*
+ * This is a module which is used for logging packets.
+ */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/tcp.h>
+#include <net/route.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ipt_LOG.h>
+#include <net/netfilter/nf_log.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: IPv4 packet logging to syslog");
+
+/* Use lock to serialize, so printks don't overlap */
+static DEFINE_SPINLOCK(log_lock);
+
+/* One level of recursion won't kill us */
+static void dump_packet(const struct nf_loginfo *info,
+			const struct sk_buff *skb,
+			unsigned int iphoff)
+{
+	struct iphdr _iph;
+	const struct iphdr *ih;
+	unsigned int logflags;
+
+	if (info->type == NF_LOG_TYPE_LOG)
+		logflags = info->u.log.logflags;
+	else
+		logflags = NF_LOG_MASK;
+
+	ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
+	if (ih == NULL) {
+		printk("TRUNCATED");
+		return;
+	}
+
+	/* Important fields:
+	 * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
+	/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
+	printk("SRC=%u.%u.%u.%u DST=%u.%u.%u.%u ",
+	       NIPQUAD(ih->saddr), NIPQUAD(ih->daddr));
+
+	/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
+	printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
+	       ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
+	       ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
+
+	/* Max length: 6 "CE DF MF " */
+	if (ntohs(ih->frag_off) & IP_CE)
+		printk("CE ");
+	if (ntohs(ih->frag_off) & IP_DF)
+		printk("DF ");
+	if (ntohs(ih->frag_off) & IP_MF)
+		printk("MF ");
+
+	/* Max length: 11 "FRAG:65535 " */
+	if (ntohs(ih->frag_off) & IP_OFFSET)
+		printk("FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
+
+	if ((logflags & IPT_LOG_IPOPT)
+	    && ih->ihl * 4 > sizeof(struct iphdr)) {
+		const unsigned char *op;
+		unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
+		unsigned int i, optsize;
+
+		optsize = ih->ihl * 4 - sizeof(struct iphdr);
+		op = skb_header_pointer(skb, iphoff+sizeof(_iph),
+					optsize, _opt);
+		if (op == NULL) {
+			printk("TRUNCATED");
+			return;
+		}
+
+		/* Max length: 127 "OPT (" 15*4*2chars ") " */
+		printk("OPT (");
+		for (i = 0; i < optsize; i++)
+			printk("%02X", op[i]);
+		printk(") ");
+	}
+
+	switch (ih->protocol) {
+	case IPPROTO_TCP: {
+		struct tcphdr _tcph;
+		const struct tcphdr *th;
+
+		/* Max length: 10 "PROTO=TCP " */
+		printk("PROTO=TCP ");
+
+		if (ntohs(ih->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		th = skb_header_pointer(skb, iphoff + ih->ihl * 4,
+					sizeof(_tcph), &_tcph);
+		if (th == NULL) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - ih->ihl*4);
+			break;
+		}
+
+		/* Max length: 20 "SPT=65535 DPT=65535 " */
+		printk("SPT=%u DPT=%u ",
+		       ntohs(th->source), ntohs(th->dest));
+		/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
+		if (logflags & IPT_LOG_TCPSEQ)
+			printk("SEQ=%u ACK=%u ",
+			       ntohl(th->seq), ntohl(th->ack_seq));
+		/* Max length: 13 "WINDOW=65535 " */
+		printk("WINDOW=%u ", ntohs(th->window));
+		/* Max length: 9 "RES=0x3F " */
+		printk("RES=0x%02x ", (u8)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
+		/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
+		if (th->cwr)
+			printk("CWR ");
+		if (th->ece)
+			printk("ECE ");
+		if (th->urg)
+			printk("URG ");
+		if (th->ack)
+			printk("ACK ");
+		if (th->psh)
+			printk("PSH ");
+		if (th->rst)
+			printk("RST ");
+		if (th->syn)
+			printk("SYN ");
+		if (th->fin)
+			printk("FIN ");
+		/* Max length: 11 "URGP=65535 " */
+		printk("URGP=%u ", ntohs(th->urg_ptr));
+
+		if ((logflags & IPT_LOG_TCPOPT)
+		    && th->doff * 4 > sizeof(struct tcphdr)) {
+			unsigned char _opt[4 * 15 - sizeof(struct tcphdr)];
+			const unsigned char *op;
+			unsigned int i, optsize;
+
+			optsize = th->doff * 4 - sizeof(struct tcphdr);
+			op = skb_header_pointer(skb,
+						iphoff+ih->ihl*4+sizeof(_tcph),
+						optsize, _opt);
+			if (op == NULL) {
+				printk("TRUNCATED");
+				return;
+			}
+
+			/* Max length: 127 "OPT (" 15*4*2chars ") " */
+			printk("OPT (");
+			for (i = 0; i < optsize; i++)
+				printk("%02X", op[i]);
+			printk(") ");
+		}
+		break;
+	}
+	case IPPROTO_UDP:
+	case IPPROTO_UDPLITE: {
+		struct udphdr _udph;
+		const struct udphdr *uh;
+
+		if (ih->protocol == IPPROTO_UDP)
+			/* Max length: 10 "PROTO=UDP "     */
+			printk("PROTO=UDP " );
+		else	/* Max length: 14 "PROTO=UDPLITE " */
+			printk("PROTO=UDPLITE ");
+
+		if (ntohs(ih->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		uh = skb_header_pointer(skb, iphoff+ih->ihl*4,
+					sizeof(_udph), &_udph);
+		if (uh == NULL) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - ih->ihl*4);
+			break;
+		}
+
+		/* Max length: 20 "SPT=65535 DPT=65535 " */
+		printk("SPT=%u DPT=%u LEN=%u ",
+		       ntohs(uh->source), ntohs(uh->dest),
+		       ntohs(uh->len));
+		break;
+	}
+	case IPPROTO_ICMP: {
+		struct icmphdr _icmph;
+		const struct icmphdr *ich;
+		static const size_t required_len[NR_ICMP_TYPES+1]
+			= { [ICMP_ECHOREPLY] = 4,
+			    [ICMP_DEST_UNREACH]
+			    = 8 + sizeof(struct iphdr),
+			    [ICMP_SOURCE_QUENCH]
+			    = 8 + sizeof(struct iphdr),
+			    [ICMP_REDIRECT]
+			    = 8 + sizeof(struct iphdr),
+			    [ICMP_ECHO] = 4,
+			    [ICMP_TIME_EXCEEDED]
+			    = 8 + sizeof(struct iphdr),
+			    [ICMP_PARAMETERPROB]
+			    = 8 + sizeof(struct iphdr),
+			    [ICMP_TIMESTAMP] = 20,
+			    [ICMP_TIMESTAMPREPLY] = 20,
+			    [ICMP_ADDRESS] = 12,
+			    [ICMP_ADDRESSREPLY] = 12 };
+
+		/* Max length: 11 "PROTO=ICMP " */
+		printk("PROTO=ICMP ");
+
+		if (ntohs(ih->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
+					 sizeof(_icmph), &_icmph);
+		if (ich == NULL) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - ih->ihl*4);
+			break;
+		}
+
+		/* Max length: 18 "TYPE=255 CODE=255 " */
+		printk("TYPE=%u CODE=%u ", ich->type, ich->code);
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		if (ich->type <= NR_ICMP_TYPES
+		    && required_len[ich->type]
+		    && skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - ih->ihl*4);
+			break;
+		}
+
+		switch (ich->type) {
+		case ICMP_ECHOREPLY:
+		case ICMP_ECHO:
+			/* Max length: 19 "ID=65535 SEQ=65535 " */
+			printk("ID=%u SEQ=%u ",
+			       ntohs(ich->un.echo.id),
+			       ntohs(ich->un.echo.sequence));
+			break;
+
+		case ICMP_PARAMETERPROB:
+			/* Max length: 14 "PARAMETER=255 " */
+			printk("PARAMETER=%u ",
+			       ntohl(ich->un.gateway) >> 24);
+			break;
+		case ICMP_REDIRECT:
+			/* Max length: 24 "GATEWAY=255.255.255.255 " */
+			printk("GATEWAY=%u.%u.%u.%u ",
+			       NIPQUAD(ich->un.gateway));
+			/* Fall through */
+		case ICMP_DEST_UNREACH:
+		case ICMP_SOURCE_QUENCH:
+		case ICMP_TIME_EXCEEDED:
+			/* Max length: 3+maxlen */
+			if (!iphoff) { /* Only recurse once. */
+				printk("[");
+				dump_packet(info, skb,
+					    iphoff + ih->ihl*4+sizeof(_icmph));
+				printk("] ");
+			}
+
+			/* Max length: 10 "MTU=65535 " */
+			if (ich->type == ICMP_DEST_UNREACH
+			    && ich->code == ICMP_FRAG_NEEDED)
+				printk("MTU=%u ", ntohs(ich->un.frag.mtu));
+		}
+		break;
+	}
+	/* Max Length */
+	case IPPROTO_AH: {
+		struct ip_auth_hdr _ahdr;
+		const struct ip_auth_hdr *ah;
+
+		if (ntohs(ih->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 9 "PROTO=AH " */
+		printk("PROTO=AH ");
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
+					sizeof(_ahdr), &_ahdr);
+		if (ah == NULL) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - ih->ihl*4);
+			break;
+		}
+
+		/* Length: 15 "SPI=0xF1234567 " */
+		printk("SPI=0x%x ", ntohl(ah->spi));
+		break;
+	}
+	case IPPROTO_ESP: {
+		struct ip_esp_hdr _esph;
+		const struct ip_esp_hdr *eh;
+
+		/* Max length: 10 "PROTO=ESP " */
+		printk("PROTO=ESP ");
+
+		if (ntohs(ih->frag_off) & IP_OFFSET)
+			break;
+
+		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
+		eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
+					sizeof(_esph), &_esph);
+		if (eh == NULL) {
+			printk("INCOMPLETE [%u bytes] ",
+			       skb->len - iphoff - ih->ihl*4);
+			break;
+		}
+
+		/* Length: 15 "SPI=0xF1234567 " */
+		printk("SPI=0x%x ", ntohl(eh->spi));
+		break;
+	}
+	/* Max length: 10 "PROTO 255 " */
+	default:
+		printk("PROTO=%u ", ih->protocol);
+	}
+
+	/* Max length: 15 "UID=4294967295 " */
+	if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
+		read_lock_bh(&skb->sk->sk_callback_lock);
+		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
+			printk("UID=%u GID=%u ",
+				skb->sk->sk_socket->file->f_uid,
+				skb->sk->sk_socket->file->f_gid);
+		read_unlock_bh(&skb->sk->sk_callback_lock);
+	}
+
+	/* Max length: 16 "MARK=0xFFFFFFFF " */
+	if (!iphoff && skb->mark)
+		printk("MARK=0x%x ", skb->mark);
+
+	/* Proto    Max log string length */
+	/* IP:      40+46+6+11+127 = 230 */
+	/* TCP:     10+max(25,20+30+13+9+32+11+127) = 252 */
+	/* UDP:     10+max(25,20) = 35 */
+	/* UDPLITE: 14+max(25,20) = 39 */
+	/* ICMP:    11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
+	/* ESP:     10+max(25)+15 = 50 */
+	/* AH:      9+max(25)+15 = 49 */
+	/* unknown: 10 */
+
+	/* (ICMP allows recursion one level deep) */
+	/* maxlen =  IP + ICMP +  IP + max(TCP,UDP,ICMP,unknown) */
+	/* maxlen = 230+   91  + 230 + 252 = 803 */
+}
+
+static struct nf_loginfo default_loginfo = {
+	.type	= NF_LOG_TYPE_LOG,
+	.u = {
+		.log = {
+			.level    = 0,
+			.logflags = NF_LOG_MASK,
+		},
+	},
+};
+
+static void
+ipt_log_packet(u_int8_t pf,
+	       unsigned int hooknum,
+	       const struct sk_buff *skb,
+	       const struct net_device *in,
+	       const struct net_device *out,
+	       const struct nf_loginfo *loginfo,
+	       const char *prefix)
+{
+	if (!loginfo)
+		loginfo = &default_loginfo;
+
+	spin_lock_bh(&log_lock);
+	printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
+	       prefix,
+	       in ? in->name : "",
+	       out ? out->name : "");
+#ifdef CONFIG_BRIDGE_NETFILTER
+	if (skb->nf_bridge) {
+		const struct net_device *physindev;
+		const struct net_device *physoutdev;
+
+		physindev = skb->nf_bridge->physindev;
+		if (physindev && in != physindev)
+			printk("PHYSIN=%s ", physindev->name);
+		physoutdev = skb->nf_bridge->physoutdev;
+		if (physoutdev && out != physoutdev)
+			printk("PHYSOUT=%s ", physoutdev->name);
+	}
+#endif
+
+	if (in && !out) {
+		/* MAC logging for input chain only. */
+		printk("MAC=");
+		if (skb->dev && skb->dev->hard_header_len
+		    && skb->mac_header != skb->network_header) {
+			int i;
+			const unsigned char *p = skb_mac_header(skb);
+			for (i = 0; i < skb->dev->hard_header_len; i++,p++)
+				printk("%02x%c", *p,
+				       i==skb->dev->hard_header_len - 1
+				       ? ' ':':');
+		} else
+			printk(" ");
+	}
+
+	dump_packet(loginfo, skb, 0);
+	printk("\n");
+	spin_unlock_bh(&log_lock);
+}
+
+static unsigned int
+log_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	const struct ipt_log_info *loginfo = par->targinfo;
+	struct nf_loginfo li;
+
+	li.type = NF_LOG_TYPE_LOG;
+	li.u.log.level = loginfo->level;
+	li.u.log.logflags = loginfo->logflags;
+
+	ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, par->out, &li,
+		       loginfo->prefix);
+	return XT_CONTINUE;
+}
+
+static bool log_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct ipt_log_info *loginfo = par->targinfo;
+
+	if (loginfo->level >= 8) {
+		pr_debug("LOG: level %u >= 8\n", loginfo->level);
+		return false;
+	}
+	if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
+		pr_debug("LOG: prefix term %i\n",
+			 loginfo->prefix[sizeof(loginfo->prefix)-1]);
+		return false;
+	}
+	return true;
+}
+
+static struct xt_target log_tg_reg __read_mostly = {
+	.name		= "LOG",
+	.family		= NFPROTO_IPV4,
+	.target		= log_tg,
+	.targetsize	= sizeof(struct ipt_log_info),
+	.checkentry	= log_tg_check,
+	.me		= THIS_MODULE,
+};
+
+static const struct nf_logger ipt_log_logger ={
+	.name		= "ipt_LOG",
+	.logfn		= &ipt_log_packet,
+	.me		= THIS_MODULE,
+};
+
+static int __init log_tg_init(void)
+{
+	int ret;
+
+	ret = xt_register_target(&log_tg_reg);
+	if (ret < 0)
+		return ret;
+	nf_log_register(NFPROTO_IPV4, &ipt_log_logger);
+	return 0;
+}
+
+static void __exit log_tg_exit(void)
+{
+	nf_log_unregister(&ipt_log_logger);
+	xt_unregister_target(&log_tg_reg);
+}
+
+module_init(log_tg_init);
+module_exit(log_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c
new file mode 100644
index 0000000..f389f60
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_MASQUERADE.c
@@ -0,0 +1,183 @@
+/* Masquerade.  Simple mapping which alters range to a local IP address
+   (depending on route). */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/inetdevice.h>
+#include <linux/ip.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <net/protocol.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include <net/route.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter/x_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: automatic-address SNAT");
+
+/* Lock protects masq region inside conntrack */
+static DEFINE_RWLOCK(masq_lock);
+
+/* FIXME: Multiple targets. --RR */
+static bool masquerade_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+		pr_debug("masquerade_check: bad MAP_IPS.\n");
+		return false;
+	}
+	if (mr->rangesize != 1) {
+		pr_debug("masquerade_check: bad rangesize %u\n", mr->rangesize);
+		return false;
+	}
+	return true;
+}
+
+static unsigned int
+masquerade_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	struct nf_conn *ct;
+	struct nf_conn_nat *nat;
+	enum ip_conntrack_info ctinfo;
+	struct nf_nat_range newrange;
+	const struct nf_nat_multi_range_compat *mr;
+	const struct rtable *rt;
+	__be32 newsrc;
+
+	NF_CT_ASSERT(par->hooknum == NF_INET_POST_ROUTING);
+
+	ct = nf_ct_get(skb, &ctinfo);
+	nat = nfct_nat(ct);
+
+	NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED
+			    || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
+
+	/* Source address is 0.0.0.0 - locally generated packet that is
+	 * probably not supposed to be masqueraded.
+	 */
+	if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip == 0)
+		return NF_ACCEPT;
+
+	mr = par->targinfo;
+	rt = skb->rtable;
+	newsrc = inet_select_addr(par->out, rt->rt_gateway, RT_SCOPE_UNIVERSE);
+	if (!newsrc) {
+		printk("MASQUERADE: %s ate my IP address\n", par->out->name);
+		return NF_DROP;
+	}
+
+	write_lock_bh(&masq_lock);
+	nat->masq_index = par->out->ifindex;
+	write_unlock_bh(&masq_lock);
+
+	/* Transfer from original range. */
+	newrange = ((struct nf_nat_range)
+		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+		  newsrc, newsrc,
+		  mr->range[0].min, mr->range[0].max });
+
+	/* Hand modified range to generic setup. */
+	return nf_nat_setup_info(ct, &newrange, IP_NAT_MANIP_SRC);
+}
+
+static int
+device_cmp(struct nf_conn *i, void *ifindex)
+{
+	const struct nf_conn_nat *nat = nfct_nat(i);
+	int ret;
+
+	if (!nat)
+		return 0;
+
+	read_lock_bh(&masq_lock);
+	ret = (nat->masq_index == (int)(long)ifindex);
+	read_unlock_bh(&masq_lock);
+
+	return ret;
+}
+
+static int masq_device_event(struct notifier_block *this,
+			     unsigned long event,
+			     void *ptr)
+{
+	const struct net_device *dev = ptr;
+	struct net *net = dev_net(dev);
+
+	if (event == NETDEV_DOWN) {
+		/* Device was downed.  Search entire table for
+		   conntracks which were associated with that device,
+		   and forget them. */
+		NF_CT_ASSERT(dev->ifindex != 0);
+
+		nf_ct_iterate_cleanup(net, device_cmp,
+				      (void *)(long)dev->ifindex);
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int masq_inet_event(struct notifier_block *this,
+			   unsigned long event,
+			   void *ptr)
+{
+	struct net_device *dev = ((struct in_ifaddr *)ptr)->ifa_dev->dev;
+	return masq_device_event(this, event, dev);
+}
+
+static struct notifier_block masq_dev_notifier = {
+	.notifier_call	= masq_device_event,
+};
+
+static struct notifier_block masq_inet_notifier = {
+	.notifier_call	= masq_inet_event,
+};
+
+static struct xt_target masquerade_tg_reg __read_mostly = {
+	.name		= "MASQUERADE",
+	.family		= NFPROTO_IPV4,
+	.target		= masquerade_tg,
+	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.table		= "nat",
+	.hooks		= 1 << NF_INET_POST_ROUTING,
+	.checkentry	= masquerade_tg_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init masquerade_tg_init(void)
+{
+	int ret;
+
+	ret = xt_register_target(&masquerade_tg_reg);
+
+	if (ret == 0) {
+		/* Register for device down reports */
+		register_netdevice_notifier(&masq_dev_notifier);
+		/* Register IP address change reports */
+		register_inetaddr_notifier(&masq_inet_notifier);
+	}
+
+	return ret;
+}
+
+static void __exit masquerade_tg_exit(void)
+{
+	xt_unregister_target(&masquerade_tg_reg);
+	unregister_netdevice_notifier(&masq_dev_notifier);
+	unregister_inetaddr_notifier(&masq_inet_notifier);
+}
+
+module_init(masquerade_tg_init);
+module_exit(masquerade_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_NETMAP.c b/net/ipv4/netfilter/ipt_NETMAP.c
new file mode 100644
index 0000000..7c29582
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_NETMAP.c
@@ -0,0 +1,96 @@
+/* NETMAP - static NAT mapping of IP network addresses (1:1).
+ * The mapping can be applied to source (POSTROUTING),
+ * destination (PREROUTING), or both (with separate rules).
+ */
+
+/* (C) 2000-2001 Svenning Soerensen <svenning@post5.tele.dk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ip.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter/x_tables.h>
+#include <net/netfilter/nf_nat_rule.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Svenning Soerensen <svenning@post5.tele.dk>");
+MODULE_DESCRIPTION("Xtables: 1:1 NAT mapping of IPv4 subnets");
+
+static bool netmap_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	if (!(mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)) {
+		pr_debug("NETMAP:check: bad MAP_IPS.\n");
+		return false;
+	}
+	if (mr->rangesize != 1) {
+		pr_debug("NETMAP:check: bad rangesize %u.\n", mr->rangesize);
+		return false;
+	}
+	return true;
+}
+
+static unsigned int
+netmap_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	__be32 new_ip, netmask;
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+	struct nf_nat_range newrange;
+
+	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
+		     par->hooknum == NF_INET_POST_ROUTING ||
+		     par->hooknum == NF_INET_LOCAL_OUT);
+	ct = nf_ct_get(skb, &ctinfo);
+
+	netmask = ~(mr->range[0].min_ip ^ mr->range[0].max_ip);
+
+	if (par->hooknum == NF_INET_PRE_ROUTING ||
+	    par->hooknum == NF_INET_LOCAL_OUT)
+		new_ip = ip_hdr(skb)->daddr & ~netmask;
+	else
+		new_ip = ip_hdr(skb)->saddr & ~netmask;
+	new_ip |= mr->range[0].min_ip & netmask;
+
+	newrange = ((struct nf_nat_range)
+		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+		  new_ip, new_ip,
+		  mr->range[0].min, mr->range[0].max });
+
+	/* Hand modified range to generic setup. */
+	return nf_nat_setup_info(ct, &newrange, HOOK2MANIP(par->hooknum));
+}
+
+static struct xt_target netmap_tg_reg __read_mostly = {
+	.name 		= "NETMAP",
+	.family		= NFPROTO_IPV4,
+	.target 	= netmap_tg,
+	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.table		= "nat",
+	.hooks		= (1 << NF_INET_PRE_ROUTING) |
+			  (1 << NF_INET_POST_ROUTING) |
+			  (1 << NF_INET_LOCAL_OUT),
+	.checkentry 	= netmap_tg_check,
+	.me 		= THIS_MODULE
+};
+
+static int __init netmap_tg_init(void)
+{
+	return xt_register_target(&netmap_tg_reg);
+}
+
+static void __exit netmap_tg_exit(void)
+{
+	xt_unregister_target(&netmap_tg_reg);
+}
+
+module_init(netmap_tg_init);
+module_exit(netmap_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_REDIRECT.c b/net/ipv4/netfilter/ipt_REDIRECT.c
new file mode 100644
index 0000000..698e5e7
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_REDIRECT.c
@@ -0,0 +1,110 @@
+/* Redirect.  Simple mapping which alters dst to a local IP address. */
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/netdevice.h>
+#include <linux/if.h>
+#include <linux/inetdevice.h>
+#include <net/protocol.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/netfilter/x_tables.h>
+#include <net/netfilter/nf_nat_rule.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: Connection redirection to localhost");
+
+/* FIXME: Take multiple ranges --RR */
+static bool redirect_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	if (mr->range[0].flags & IP_NAT_RANGE_MAP_IPS) {
+		pr_debug("redirect_check: bad MAP_IPS.\n");
+		return false;
+	}
+	if (mr->rangesize != 1) {
+		pr_debug("redirect_check: bad rangesize %u.\n", mr->rangesize);
+		return false;
+	}
+	return true;
+}
+
+static unsigned int
+redirect_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	__be32 newdst;
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+	struct nf_nat_range newrange;
+
+	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
+		     par->hooknum == NF_INET_LOCAL_OUT);
+
+	ct = nf_ct_get(skb, &ctinfo);
+	NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
+
+	/* Local packets: make them go to loopback */
+	if (par->hooknum == NF_INET_LOCAL_OUT)
+		newdst = htonl(0x7F000001);
+	else {
+		struct in_device *indev;
+		struct in_ifaddr *ifa;
+
+		newdst = 0;
+
+		rcu_read_lock();
+		indev = __in_dev_get_rcu(skb->dev);
+		if (indev && (ifa = indev->ifa_list))
+			newdst = ifa->ifa_local;
+		rcu_read_unlock();
+
+		if (!newdst)
+			return NF_DROP;
+	}
+
+	/* Transfer from original range. */
+	newrange = ((struct nf_nat_range)
+		{ mr->range[0].flags | IP_NAT_RANGE_MAP_IPS,
+		  newdst, newdst,
+		  mr->range[0].min, mr->range[0].max });
+
+	/* Hand modified range to generic setup. */
+	return nf_nat_setup_info(ct, &newrange, IP_NAT_MANIP_DST);
+}
+
+static struct xt_target redirect_tg_reg __read_mostly = {
+	.name		= "REDIRECT",
+	.family		= NFPROTO_IPV4,
+	.target		= redirect_tg,
+	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.table		= "nat",
+	.hooks		= (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT),
+	.checkentry	= redirect_tg_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init redirect_tg_init(void)
+{
+	return xt_register_target(&redirect_tg_reg);
+}
+
+static void __exit redirect_tg_exit(void)
+{
+	xt_unregister_target(&redirect_tg_reg);
+}
+
+module_init(redirect_tg_init);
+module_exit(redirect_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_REJECT.c b/net/ipv4/netfilter/ipt_REJECT.c
new file mode 100644
index 0000000..0b4b6e0
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_REJECT.c
@@ -0,0 +1,220 @@
+/*
+ * This is a module which is used for rejecting packets.
+ */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/icmp.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/tcp.h>
+#include <net/route.h>
+#include <net/dst.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_REJECT.h>
+#ifdef CONFIG_BRIDGE_NETFILTER
+#include <linux/netfilter_bridge.h>
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv4");
+
+/* Send RST reply */
+static void send_reset(struct sk_buff *oldskb, int hook)
+{
+	struct sk_buff *nskb;
+	const struct iphdr *oiph;
+	struct iphdr *niph;
+	const struct tcphdr *oth;
+	struct tcphdr _otcph, *tcph;
+	unsigned int addr_type;
+
+	/* IP header checks: fragment. */
+	if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
+		return;
+
+	oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
+				 sizeof(_otcph), &_otcph);
+	if (oth == NULL)
+		return;
+
+	/* No RST for RST. */
+	if (oth->rst)
+		return;
+
+	/* Check checksum */
+	if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
+		return;
+	oiph = ip_hdr(oldskb);
+
+	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) +
+			 LL_MAX_HEADER, GFP_ATOMIC);
+	if (!nskb)
+		return;
+
+	skb_reserve(nskb, LL_MAX_HEADER);
+
+	skb_reset_network_header(nskb);
+	niph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
+	niph->version	= 4;
+	niph->ihl	= sizeof(struct iphdr) / 4;
+	niph->tos	= 0;
+	niph->id	= 0;
+	niph->frag_off	= htons(IP_DF);
+	niph->protocol	= IPPROTO_TCP;
+	niph->check	= 0;
+	niph->saddr	= oiph->daddr;
+	niph->daddr	= oiph->saddr;
+
+	tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr));
+	memset(tcph, 0, sizeof(*tcph));
+	tcph->source	= oth->dest;
+	tcph->dest	= oth->source;
+	tcph->doff	= sizeof(struct tcphdr) / 4;
+
+	if (oth->ack)
+		tcph->seq = oth->ack_seq;
+	else {
+		tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
+				      oldskb->len - ip_hdrlen(oldskb) -
+				      (oth->doff << 2));
+		tcph->ack = 1;
+	}
+
+	tcph->rst	= 1;
+	tcph->check	= tcp_v4_check(sizeof(struct tcphdr),
+				       niph->saddr, niph->daddr,
+				       csum_partial(tcph,
+						    sizeof(struct tcphdr), 0));
+
+	addr_type = RTN_UNSPEC;
+	if (hook != NF_INET_FORWARD
+#ifdef CONFIG_BRIDGE_NETFILTER
+	    || (nskb->nf_bridge && nskb->nf_bridge->mask & BRNF_BRIDGED)
+#endif
+	   )
+		addr_type = RTN_LOCAL;
+
+	/* ip_route_me_harder expects skb->dst to be set */
+	dst_hold(oldskb->dst);
+	nskb->dst = oldskb->dst;
+
+	if (ip_route_me_harder(nskb, addr_type))
+		goto free_nskb;
+
+	niph->ttl	= dst_metric(nskb->dst, RTAX_HOPLIMIT);
+	nskb->ip_summed = CHECKSUM_NONE;
+
+	/* "Never happens" */
+	if (nskb->len > dst_mtu(nskb->dst))
+		goto free_nskb;
+
+	nf_ct_attach(nskb, oldskb);
+
+	ip_local_out(nskb);
+	return;
+
+ free_nskb:
+	kfree_skb(nskb);
+}
+
+static inline void send_unreach(struct sk_buff *skb_in, int code)
+{
+	icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0);
+}
+
+static unsigned int
+reject_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	const struct ipt_reject_info *reject = par->targinfo;
+
+	/* WARNING: This code causes reentry within iptables.
+	   This means that the iptables jump stack is now crap.  We
+	   must return an absolute verdict. --RR */
+	switch (reject->with) {
+	case IPT_ICMP_NET_UNREACHABLE:
+		send_unreach(skb, ICMP_NET_UNREACH);
+		break;
+	case IPT_ICMP_HOST_UNREACHABLE:
+		send_unreach(skb, ICMP_HOST_UNREACH);
+		break;
+	case IPT_ICMP_PROT_UNREACHABLE:
+		send_unreach(skb, ICMP_PROT_UNREACH);
+		break;
+	case IPT_ICMP_PORT_UNREACHABLE:
+		send_unreach(skb, ICMP_PORT_UNREACH);
+		break;
+	case IPT_ICMP_NET_PROHIBITED:
+		send_unreach(skb, ICMP_NET_ANO);
+		break;
+	case IPT_ICMP_HOST_PROHIBITED:
+		send_unreach(skb, ICMP_HOST_ANO);
+		break;
+	case IPT_ICMP_ADMIN_PROHIBITED:
+		send_unreach(skb, ICMP_PKT_FILTERED);
+		break;
+	case IPT_TCP_RESET:
+		send_reset(skb, par->hooknum);
+	case IPT_ICMP_ECHOREPLY:
+		/* Doesn't happen. */
+		break;
+	}
+
+	return NF_DROP;
+}
+
+static bool reject_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct ipt_reject_info *rejinfo = par->targinfo;
+	const struct ipt_entry *e = par->entryinfo;
+
+	if (rejinfo->with == IPT_ICMP_ECHOREPLY) {
+		printk("ipt_REJECT: ECHOREPLY no longer supported.\n");
+		return false;
+	} else if (rejinfo->with == IPT_TCP_RESET) {
+		/* Must specify that it's a TCP packet */
+		if (e->ip.proto != IPPROTO_TCP
+		    || (e->ip.invflags & XT_INV_PROTO)) {
+			printk("ipt_REJECT: TCP_RESET invalid for non-tcp\n");
+			return false;
+		}
+	}
+	return true;
+}
+
+static struct xt_target reject_tg_reg __read_mostly = {
+	.name		= "REJECT",
+	.family		= NFPROTO_IPV4,
+	.target		= reject_tg,
+	.targetsize	= sizeof(struct ipt_reject_info),
+	.table		= "filter",
+	.hooks		= (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
+			  (1 << NF_INET_LOCAL_OUT),
+	.checkentry	= reject_tg_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init reject_tg_init(void)
+{
+	return xt_register_target(&reject_tg_reg);
+}
+
+static void __exit reject_tg_exit(void)
+{
+	xt_unregister_target(&reject_tg_reg);
+}
+
+module_init(reject_tg_init);
+module_exit(reject_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_TTL.c b/net/ipv4/netfilter/ipt_TTL.c
new file mode 100644
index 0000000..6d76aae
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_TTL.c
@@ -0,0 +1,97 @@
+/* TTL modification target for IP tables
+ * (C) 2000,2005 by Harald Welte <laforge@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ipt_TTL.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: IPv4 TTL field modification target");
+MODULE_LICENSE("GPL");
+
+static unsigned int
+ttl_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	struct iphdr *iph;
+	const struct ipt_TTL_info *info = par->targinfo;
+	int new_ttl;
+
+	if (!skb_make_writable(skb, skb->len))
+		return NF_DROP;
+
+	iph = ip_hdr(skb);
+
+	switch (info->mode) {
+		case IPT_TTL_SET:
+			new_ttl = info->ttl;
+			break;
+		case IPT_TTL_INC:
+			new_ttl = iph->ttl + info->ttl;
+			if (new_ttl > 255)
+				new_ttl = 255;
+			break;
+		case IPT_TTL_DEC:
+			new_ttl = iph->ttl - info->ttl;
+			if (new_ttl < 0)
+				new_ttl = 0;
+			break;
+		default:
+			new_ttl = iph->ttl;
+			break;
+	}
+
+	if (new_ttl != iph->ttl) {
+		csum_replace2(&iph->check, htons(iph->ttl << 8),
+					   htons(new_ttl << 8));
+		iph->ttl = new_ttl;
+	}
+
+	return XT_CONTINUE;
+}
+
+static bool ttl_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct ipt_TTL_info *info = par->targinfo;
+
+	if (info->mode > IPT_TTL_MAXMODE) {
+		printk(KERN_WARNING "ipt_TTL: invalid or unknown Mode %u\n",
+			info->mode);
+		return false;
+	}
+	if (info->mode != IPT_TTL_SET && info->ttl == 0)
+		return false;
+	return true;
+}
+
+static struct xt_target ttl_tg_reg __read_mostly = {
+	.name 		= "TTL",
+	.family		= NFPROTO_IPV4,
+	.target 	= ttl_tg,
+	.targetsize	= sizeof(struct ipt_TTL_info),
+	.table		= "mangle",
+	.checkentry 	= ttl_tg_check,
+	.me 		= THIS_MODULE,
+};
+
+static int __init ttl_tg_init(void)
+{
+	return xt_register_target(&ttl_tg_reg);
+}
+
+static void __exit ttl_tg_exit(void)
+{
+	xt_unregister_target(&ttl_tg_reg);
+}
+
+module_init(ttl_tg_init);
+module_exit(ttl_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
new file mode 100644
index 0000000..18a2826
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -0,0 +1,448 @@
+/*
+ * netfilter module for userspace packet logging daemons
+ *
+ * (C) 2000-2004 by Harald Welte <laforge@netfilter.org>
+ * (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This module accepts two parameters:
+ *
+ * nlbufsiz:
+ *   The parameter specifies how big the buffer for each netlink multicast
+ * group is. e.g. If you say nlbufsiz=8192, up to eight kb of packets will
+ * get accumulated in the kernel until they are sent to userspace. It is
+ * NOT possible to allocate more than 128kB, and it is strongly discouraged,
+ * because atomically allocating 128kB inside the network rx softirq is not
+ * reliable. Please also keep in mind that this buffer size is allocated for
+ * each nlgroup you are using, so the total kernel memory usage increases
+ * by that factor.
+ *
+ * Actually you should use nlbufsiz a bit smaller than PAGE_SIZE, since
+ * nlbufsiz is used with alloc_skb, which adds another
+ * sizeof(struct skb_shared_info).  Use NLMSG_GOODSIZE instead.
+ *
+ * flushtimeout:
+ *   Specify, after how many hundredths of a second the queue should be
+ *   flushed even if it is not full yet.
+ */
+
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/netlink.h>
+#include <linux/netdevice.h>
+#include <linux/mm.h>
+#include <linux/moduleparam.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ipt_ULOG.h>
+#include <net/netfilter/nf_log.h>
+#include <net/sock.h>
+#include <linux/bitops.h>
+#include <asm/unaligned.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("Xtables: packet logging to netlink using ULOG");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NFLOG);
+
+#define ULOG_NL_EVENT		111		/* Harald's favorite number */
+#define ULOG_MAXNLGROUPS	32		/* numer of nlgroups */
+
+#define PRINTR(format, args...) do { if (net_ratelimit()) printk(format , ## args); } while (0)
+
+static unsigned int nlbufsiz = NLMSG_GOODSIZE;
+module_param(nlbufsiz, uint, 0400);
+MODULE_PARM_DESC(nlbufsiz, "netlink buffer size");
+
+static unsigned int flushtimeout = 10;
+module_param(flushtimeout, uint, 0600);
+MODULE_PARM_DESC(flushtimeout, "buffer flush timeout (hundredths of a second)");
+
+static int nflog = 1;
+module_param(nflog, bool, 0400);
+MODULE_PARM_DESC(nflog, "register as internal netfilter logging module");
+
+/* global data structures */
+
+typedef struct {
+	unsigned int qlen;		/* number of nlmsgs' in the skb */
+	struct nlmsghdr *lastnlh;	/* netlink header of last msg in skb */
+	struct sk_buff *skb;		/* the pre-allocated skb */
+	struct timer_list timer;	/* the timer function */
+} ulog_buff_t;
+
+static ulog_buff_t ulog_buffers[ULOG_MAXNLGROUPS];	/* array of buffers */
+
+static struct sock *nflognl;		/* our socket */
+static DEFINE_SPINLOCK(ulog_lock);	/* spinlock */
+
+/* send one ulog_buff_t to userspace */
+static void ulog_send(unsigned int nlgroupnum)
+{
+	ulog_buff_t *ub = &ulog_buffers[nlgroupnum];
+
+	if (timer_pending(&ub->timer)) {
+		pr_debug("ipt_ULOG: ulog_send: timer was pending, deleting\n");
+		del_timer(&ub->timer);
+	}
+
+	if (!ub->skb) {
+		pr_debug("ipt_ULOG: ulog_send: nothing to send\n");
+		return;
+	}
+
+	/* last nlmsg needs NLMSG_DONE */
+	if (ub->qlen > 1)
+		ub->lastnlh->nlmsg_type = NLMSG_DONE;
+
+	NETLINK_CB(ub->skb).dst_group = nlgroupnum + 1;
+	pr_debug("ipt_ULOG: throwing %d packets to netlink group %u\n",
+		 ub->qlen, nlgroupnum + 1);
+	netlink_broadcast(nflognl, ub->skb, 0, nlgroupnum + 1, GFP_ATOMIC);
+
+	ub->qlen = 0;
+	ub->skb = NULL;
+	ub->lastnlh = NULL;
+}
+
+
+/* timer function to flush queue in flushtimeout time */
+static void ulog_timer(unsigned long data)
+{
+	pr_debug("ipt_ULOG: timer function called, calling ulog_send\n");
+
+	/* lock to protect against somebody modifying our structure
+	 * from ipt_ulog_target at the same time */
+	spin_lock_bh(&ulog_lock);
+	ulog_send(data);
+	spin_unlock_bh(&ulog_lock);
+}
+
+static struct sk_buff *ulog_alloc_skb(unsigned int size)
+{
+	struct sk_buff *skb;
+	unsigned int n;
+
+	/* alloc skb which should be big enough for a whole
+	 * multipart message. WARNING: has to be <= 131000
+	 * due to slab allocator restrictions */
+
+	n = max(size, nlbufsiz);
+	skb = alloc_skb(n, GFP_ATOMIC);
+	if (!skb) {
+		PRINTR("ipt_ULOG: can't alloc whole buffer %ub!\n", n);
+
+		if (n > size) {
+			/* try to allocate only as much as we need for
+			 * current packet */
+
+			skb = alloc_skb(size, GFP_ATOMIC);
+			if (!skb)
+				PRINTR("ipt_ULOG: can't even allocate %ub\n",
+				       size);
+		}
+	}
+
+	return skb;
+}
+
+static void ipt_ulog_packet(unsigned int hooknum,
+			    const struct sk_buff *skb,
+			    const struct net_device *in,
+			    const struct net_device *out,
+			    const struct ipt_ulog_info *loginfo,
+			    const char *prefix)
+{
+	ulog_buff_t *ub;
+	ulog_packet_msg_t *pm;
+	size_t size, copy_len;
+	struct nlmsghdr *nlh;
+	struct timeval tv;
+
+	/* ffs == find first bit set, necessary because userspace
+	 * is already shifting groupnumber, but we need unshifted.
+	 * ffs() returns [1..32], we need [0..31] */
+	unsigned int groupnum = ffs(loginfo->nl_group) - 1;
+
+	/* calculate the size of the skb needed */
+	if (loginfo->copy_range == 0 || loginfo->copy_range > skb->len)
+		copy_len = skb->len;
+	else
+		copy_len = loginfo->copy_range;
+
+	size = NLMSG_SPACE(sizeof(*pm) + copy_len);
+
+	ub = &ulog_buffers[groupnum];
+
+	spin_lock_bh(&ulog_lock);
+
+	if (!ub->skb) {
+		if (!(ub->skb = ulog_alloc_skb(size)))
+			goto alloc_failure;
+	} else if (ub->qlen >= loginfo->qthreshold ||
+		   size > skb_tailroom(ub->skb)) {
+		/* either the queue len is too high or we don't have
+		 * enough room in nlskb left. send it to userspace. */
+
+		ulog_send(groupnum);
+
+		if (!(ub->skb = ulog_alloc_skb(size)))
+			goto alloc_failure;
+	}
+
+	pr_debug("ipt_ULOG: qlen %d, qthreshold %Zu\n", ub->qlen,
+		 loginfo->qthreshold);
+
+	/* NLMSG_PUT contains a hidden goto nlmsg_failure !!! */
+	nlh = NLMSG_PUT(ub->skb, 0, ub->qlen, ULOG_NL_EVENT,
+			sizeof(*pm)+copy_len);
+	ub->qlen++;
+
+	pm = NLMSG_DATA(nlh);
+
+	/* We might not have a timestamp, get one */
+	if (skb->tstamp.tv64 == 0)
+		__net_timestamp((struct sk_buff *)skb);
+
+	/* copy hook, prefix, timestamp, payload, etc. */
+	pm->data_len = copy_len;
+	tv = ktime_to_timeval(skb->tstamp);
+	put_unaligned(tv.tv_sec, &pm->timestamp_sec);
+	put_unaligned(tv.tv_usec, &pm->timestamp_usec);
+	put_unaligned(skb->mark, &pm->mark);
+	pm->hook = hooknum;
+	if (prefix != NULL)
+		strncpy(pm->prefix, prefix, sizeof(pm->prefix));
+	else if (loginfo->prefix[0] != '\0')
+		strncpy(pm->prefix, loginfo->prefix, sizeof(pm->prefix));
+	else
+		*(pm->prefix) = '\0';
+
+	if (in && in->hard_header_len > 0
+	    && skb->mac_header != skb->network_header
+	    && in->hard_header_len <= ULOG_MAC_LEN) {
+		memcpy(pm->mac, skb_mac_header(skb), in->hard_header_len);
+		pm->mac_len = in->hard_header_len;
+	} else
+		pm->mac_len = 0;
+
+	if (in)
+		strncpy(pm->indev_name, in->name, sizeof(pm->indev_name));
+	else
+		pm->indev_name[0] = '\0';
+
+	if (out)
+		strncpy(pm->outdev_name, out->name, sizeof(pm->outdev_name));
+	else
+		pm->outdev_name[0] = '\0';
+
+	/* copy_len <= skb->len, so can't fail. */
+	if (skb_copy_bits(skb, 0, pm->payload, copy_len) < 0)
+		BUG();
+
+	/* check if we are building multi-part messages */
+	if (ub->qlen > 1)
+		ub->lastnlh->nlmsg_flags |= NLM_F_MULTI;
+
+	ub->lastnlh = nlh;
+
+	/* if timer isn't already running, start it */
+	if (!timer_pending(&ub->timer)) {
+		ub->timer.expires = jiffies + flushtimeout * HZ / 100;
+		add_timer(&ub->timer);
+	}
+
+	/* if threshold is reached, send message to userspace */
+	if (ub->qlen >= loginfo->qthreshold) {
+		if (loginfo->qthreshold > 1)
+			nlh->nlmsg_type = NLMSG_DONE;
+		ulog_send(groupnum);
+	}
+
+	spin_unlock_bh(&ulog_lock);
+
+	return;
+
+nlmsg_failure:
+	PRINTR("ipt_ULOG: error during NLMSG_PUT\n");
+
+alloc_failure:
+	PRINTR("ipt_ULOG: Error building netlink message\n");
+
+	spin_unlock_bh(&ulog_lock);
+}
+
+static unsigned int
+ulog_tg(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	ipt_ulog_packet(par->hooknum, skb, par->in, par->out,
+	                par->targinfo, NULL);
+	return XT_CONTINUE;
+}
+
+static void ipt_logfn(u_int8_t pf,
+		      unsigned int hooknum,
+		      const struct sk_buff *skb,
+		      const struct net_device *in,
+		      const struct net_device *out,
+		      const struct nf_loginfo *li,
+		      const char *prefix)
+{
+	struct ipt_ulog_info loginfo;
+
+	if (!li || li->type != NF_LOG_TYPE_ULOG) {
+		loginfo.nl_group = ULOG_DEFAULT_NLGROUP;
+		loginfo.copy_range = 0;
+		loginfo.qthreshold = ULOG_DEFAULT_QTHRESHOLD;
+		loginfo.prefix[0] = '\0';
+	} else {
+		loginfo.nl_group = li->u.ulog.group;
+		loginfo.copy_range = li->u.ulog.copy_len;
+		loginfo.qthreshold = li->u.ulog.qthreshold;
+		strlcpy(loginfo.prefix, prefix, sizeof(loginfo.prefix));
+	}
+
+	ipt_ulog_packet(hooknum, skb, in, out, &loginfo, prefix);
+}
+
+static bool ulog_tg_check(const struct xt_tgchk_param *par)
+{
+	const struct ipt_ulog_info *loginfo = par->targinfo;
+
+	if (loginfo->prefix[sizeof(loginfo->prefix) - 1] != '\0') {
+		pr_debug("ipt_ULOG: prefix term %i\n",
+			 loginfo->prefix[sizeof(loginfo->prefix) - 1]);
+		return false;
+	}
+	if (loginfo->qthreshold > ULOG_MAX_QLEN) {
+		pr_debug("ipt_ULOG: queue threshold %Zu > MAX_QLEN\n",
+			 loginfo->qthreshold);
+		return false;
+	}
+	return true;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_ipt_ulog_info {
+	compat_uint_t	nl_group;
+	compat_size_t	copy_range;
+	compat_size_t	qthreshold;
+	char		prefix[ULOG_PREFIX_LEN];
+};
+
+static void ulog_tg_compat_from_user(void *dst, void *src)
+{
+	const struct compat_ipt_ulog_info *cl = src;
+	struct ipt_ulog_info l = {
+		.nl_group	= cl->nl_group,
+		.copy_range	= cl->copy_range,
+		.qthreshold	= cl->qthreshold,
+	};
+
+	memcpy(l.prefix, cl->prefix, sizeof(l.prefix));
+	memcpy(dst, &l, sizeof(l));
+}
+
+static int ulog_tg_compat_to_user(void __user *dst, void *src)
+{
+	const struct ipt_ulog_info *l = src;
+	struct compat_ipt_ulog_info cl = {
+		.nl_group	= l->nl_group,
+		.copy_range	= l->copy_range,
+		.qthreshold	= l->qthreshold,
+	};
+
+	memcpy(cl.prefix, l->prefix, sizeof(cl.prefix));
+	return copy_to_user(dst, &cl, sizeof(cl)) ? -EFAULT : 0;
+}
+#endif /* CONFIG_COMPAT */
+
+static struct xt_target ulog_tg_reg __read_mostly = {
+	.name		= "ULOG",
+	.family		= NFPROTO_IPV4,
+	.target		= ulog_tg,
+	.targetsize	= sizeof(struct ipt_ulog_info),
+	.checkentry	= ulog_tg_check,
+#ifdef CONFIG_COMPAT
+	.compatsize	= sizeof(struct compat_ipt_ulog_info),
+	.compat_from_user = ulog_tg_compat_from_user,
+	.compat_to_user	= ulog_tg_compat_to_user,
+#endif
+	.me		= THIS_MODULE,
+};
+
+static struct nf_logger ipt_ulog_logger = {
+	.name		= "ipt_ULOG",
+	.logfn		= ipt_logfn,
+	.me		= THIS_MODULE,
+};
+
+static int __init ulog_tg_init(void)
+{
+	int ret, i;
+
+	pr_debug("ipt_ULOG: init module\n");
+
+	if (nlbufsiz > 128*1024) {
+		printk("Netlink buffer has to be <= 128kB\n");
+		return -EINVAL;
+	}
+
+	/* initialize ulog_buffers */
+	for (i = 0; i < ULOG_MAXNLGROUPS; i++)
+		setup_timer(&ulog_buffers[i].timer, ulog_timer, i);
+
+	nflognl = netlink_kernel_create(&init_net,
+					NETLINK_NFLOG, ULOG_MAXNLGROUPS, NULL,
+					NULL, THIS_MODULE);
+	if (!nflognl)
+		return -ENOMEM;
+
+	ret = xt_register_target(&ulog_tg_reg);
+	if (ret < 0) {
+		netlink_kernel_release(nflognl);
+		return ret;
+	}
+	if (nflog)
+		nf_log_register(NFPROTO_IPV4, &ipt_ulog_logger);
+
+	return 0;
+}
+
+static void __exit ulog_tg_exit(void)
+{
+	ulog_buff_t *ub;
+	int i;
+
+	pr_debug("ipt_ULOG: cleanup_module\n");
+
+	if (nflog)
+		nf_log_unregister(&ipt_ulog_logger);
+	xt_unregister_target(&ulog_tg_reg);
+	netlink_kernel_release(nflognl);
+
+	/* remove pending timers and free allocated skb's */
+	for (i = 0; i < ULOG_MAXNLGROUPS; i++) {
+		ub = &ulog_buffers[i];
+		if (timer_pending(&ub->timer)) {
+			pr_debug("timer was pending, deleting\n");
+			del_timer(&ub->timer);
+		}
+
+		if (ub->skb) {
+			kfree_skb(ub->skb);
+			ub->skb = NULL;
+		}
+	}
+}
+
+module_init(ulog_tg_init);
+module_exit(ulog_tg_exit);
diff --git a/net/ipv4/netfilter/ipt_addrtype.c b/net/ipv4/netfilter/ipt_addrtype.c
new file mode 100644
index 0000000..88762f0
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_addrtype.c
@@ -0,0 +1,132 @@
+/*
+ *  iptables module to match inet_addr_type() of an ip.
+ *
+ *  Copyright (c) 2004 Patrick McHardy <kaber@trash.net>
+ *  (C) 2007 Laszlo Attila Toth <panther@balabit.hu>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/ip.h>
+#include <net/route.h>
+
+#include <linux/netfilter_ipv4/ipt_addrtype.h>
+#include <linux/netfilter/x_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("Xtables: address type match for IPv4");
+
+static inline bool match_type(const struct net_device *dev, __be32 addr,
+			      u_int16_t mask)
+{
+	return !!(mask & (1 << inet_dev_addr_type(&init_net, dev, addr)));
+}
+
+static bool
+addrtype_mt_v0(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+	const struct ipt_addrtype_info *info = par->matchinfo;
+	const struct iphdr *iph = ip_hdr(skb);
+	bool ret = true;
+
+	if (info->source)
+		ret &= match_type(NULL, iph->saddr, info->source) ^
+		       info->invert_source;
+	if (info->dest)
+		ret &= match_type(NULL, iph->daddr, info->dest) ^
+		       info->invert_dest;
+
+	return ret;
+}
+
+static bool
+addrtype_mt_v1(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+	const struct ipt_addrtype_info_v1 *info = par->matchinfo;
+	const struct iphdr *iph = ip_hdr(skb);
+	const struct net_device *dev = NULL;
+	bool ret = true;
+
+	if (info->flags & IPT_ADDRTYPE_LIMIT_IFACE_IN)
+		dev = par->in;
+	else if (info->flags & IPT_ADDRTYPE_LIMIT_IFACE_OUT)
+		dev = par->out;
+
+	if (info->source)
+		ret &= match_type(dev, iph->saddr, info->source) ^
+		       (info->flags & IPT_ADDRTYPE_INVERT_SOURCE);
+	if (ret && info->dest)
+		ret &= match_type(dev, iph->daddr, info->dest) ^
+		       !!(info->flags & IPT_ADDRTYPE_INVERT_DEST);
+	return ret;
+}
+
+static bool addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par)
+{
+	struct ipt_addrtype_info_v1 *info = par->matchinfo;
+
+	if (info->flags & IPT_ADDRTYPE_LIMIT_IFACE_IN &&
+	    info->flags & IPT_ADDRTYPE_LIMIT_IFACE_OUT) {
+		printk(KERN_ERR "ipt_addrtype: both incoming and outgoing "
+				"interface limitation cannot be selected\n");
+		return false;
+	}
+
+	if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) |
+	    (1 << NF_INET_LOCAL_IN)) &&
+	    info->flags & IPT_ADDRTYPE_LIMIT_IFACE_OUT) {
+		printk(KERN_ERR "ipt_addrtype: output interface limitation "
+				"not valid in PRE_ROUTING and INPUT\n");
+		return false;
+	}
+
+	if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) |
+	    (1 << NF_INET_LOCAL_OUT)) &&
+	    info->flags & IPT_ADDRTYPE_LIMIT_IFACE_IN) {
+		printk(KERN_ERR "ipt_addrtype: input interface limitation "
+				"not valid in POST_ROUTING and OUTPUT\n");
+		return false;
+	}
+
+	return true;
+}
+
+static struct xt_match addrtype_mt_reg[] __read_mostly = {
+	{
+		.name		= "addrtype",
+		.family		= NFPROTO_IPV4,
+		.match		= addrtype_mt_v0,
+		.matchsize	= sizeof(struct ipt_addrtype_info),
+		.me		= THIS_MODULE
+	},
+	{
+		.name		= "addrtype",
+		.family		= NFPROTO_IPV4,
+		.revision	= 1,
+		.match		= addrtype_mt_v1,
+		.checkentry	= addrtype_mt_checkentry_v1,
+		.matchsize	= sizeof(struct ipt_addrtype_info_v1),
+		.me		= THIS_MODULE
+	}
+};
+
+static int __init addrtype_mt_init(void)
+{
+	return xt_register_matches(addrtype_mt_reg,
+				   ARRAY_SIZE(addrtype_mt_reg));
+}
+
+static void __exit addrtype_mt_exit(void)
+{
+	xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg));
+}
+
+module_init(addrtype_mt_init);
+module_exit(addrtype_mt_exit);
diff --git a/net/ipv4/netfilter/ipt_ah.c b/net/ipv4/netfilter/ipt_ah.c
new file mode 100644
index 0000000..0104c0b
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_ah.c
@@ -0,0 +1,97 @@
+/* Kernel module to match AH parameters. */
+/* (C) 1999-2000 Yon Uriarte <yon@astaro.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/in.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+
+#include <linux/netfilter_ipv4/ipt_ah.h>
+#include <linux/netfilter/x_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yon Uriarte <yon@astaro.de>");
+MODULE_DESCRIPTION("Xtables: IPv4 IPsec-AH SPI match");
+
+#ifdef DEBUG_CONNTRACK
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+/* Returns 1 if the spi is matched by the range, 0 otherwise */
+static inline bool
+spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, bool invert)
+{
+	bool r;
+	duprintf("ah spi_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
+		min,spi,max);
+	r=(spi >= min && spi <= max) ^ invert;
+	duprintf(" result %s\n",r? "PASS" : "FAILED");
+	return r;
+}
+
+static bool ah_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+	struct ip_auth_hdr _ahdr;
+	const struct ip_auth_hdr *ah;
+	const struct ipt_ah *ahinfo = par->matchinfo;
+
+	/* Must not be a fragment. */
+	if (par->fragoff != 0)
+		return false;
+
+	ah = skb_header_pointer(skb, par->thoff, sizeof(_ahdr), &_ahdr);
+	if (ah == NULL) {
+		/* We've been asked to examine this packet, and we
+		 * can't.  Hence, no choice but to drop.
+		 */
+		duprintf("Dropping evil AH tinygram.\n");
+		*par->hotdrop = true;
+		return 0;
+	}
+
+	return spi_match(ahinfo->spis[0], ahinfo->spis[1],
+			 ntohl(ah->spi),
+			 !!(ahinfo->invflags & IPT_AH_INV_SPI));
+}
+
+static bool ah_mt_check(const struct xt_mtchk_param *par)
+{
+	const struct ipt_ah *ahinfo = par->matchinfo;
+
+	/* Must specify no unknown invflags */
+	if (ahinfo->invflags & ~IPT_AH_INV_MASK) {
+		duprintf("ipt_ah: unknown flags %X\n", ahinfo->invflags);
+		return false;
+	}
+	return true;
+}
+
+static struct xt_match ah_mt_reg __read_mostly = {
+	.name		= "ah",
+	.family		= NFPROTO_IPV4,
+	.match		= ah_mt,
+	.matchsize	= sizeof(struct ipt_ah),
+	.proto		= IPPROTO_AH,
+	.checkentry	= ah_mt_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init ah_mt_init(void)
+{
+	return xt_register_match(&ah_mt_reg);
+}
+
+static void __exit ah_mt_exit(void)
+{
+	xt_unregister_match(&ah_mt_reg);
+}
+
+module_init(ah_mt_init);
+module_exit(ah_mt_exit);
diff --git a/net/ipv4/netfilter/ipt_ecn.c b/net/ipv4/netfilter/ipt_ecn.c
new file mode 100644
index 0000000..6289b64
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_ecn.c
@@ -0,0 +1,129 @@
+/* IP tables module for matching the value of the IPv4 and TCP ECN bits
+ *
+ * (C) 2002 by Harald Welte <laforge@gnumonks.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ecn.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: Explicit Congestion Notification (ECN) flag match for IPv4");
+MODULE_LICENSE("GPL");
+
+static inline bool match_ip(const struct sk_buff *skb,
+			    const struct ipt_ecn_info *einfo)
+{
+	return (ip_hdr(skb)->tos & IPT_ECN_IP_MASK) == einfo->ip_ect;
+}
+
+static inline bool match_tcp(const struct sk_buff *skb,
+			     const struct ipt_ecn_info *einfo,
+			     bool *hotdrop)
+{
+	struct tcphdr _tcph;
+	const struct tcphdr *th;
+
+	/* In practice, TCP match does this, so can't fail.  But let's
+	 * be good citizens.
+	 */
+	th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
+	if (th == NULL) {
+		*hotdrop = false;
+		return false;
+	}
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_ECE) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_ECE) {
+			if (th->ece == 1)
+				return false;
+		} else {
+			if (th->ece == 0)
+				return false;
+		}
+	}
+
+	if (einfo->operation & IPT_ECN_OP_MATCH_CWR) {
+		if (einfo->invert & IPT_ECN_OP_MATCH_CWR) {
+			if (th->cwr == 1)
+				return false;
+		} else {
+			if (th->cwr == 0)
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static bool ecn_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+	const struct ipt_ecn_info *info = par->matchinfo;
+
+	if (info->operation & IPT_ECN_OP_MATCH_IP)
+		if (!match_ip(skb, info))
+			return false;
+
+	if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)) {
+		if (ip_hdr(skb)->protocol != IPPROTO_TCP)
+			return false;
+		if (!match_tcp(skb, info, par->hotdrop))
+			return false;
+	}
+
+	return true;
+}
+
+static bool ecn_mt_check(const struct xt_mtchk_param *par)
+{
+	const struct ipt_ecn_info *info = par->matchinfo;
+	const struct ipt_ip *ip = par->entryinfo;
+
+	if (info->operation & IPT_ECN_OP_MATCH_MASK)
+		return false;
+
+	if (info->invert & IPT_ECN_OP_MATCH_MASK)
+		return false;
+
+	if (info->operation & (IPT_ECN_OP_MATCH_ECE|IPT_ECN_OP_MATCH_CWR)
+	    && ip->proto != IPPROTO_TCP) {
+		printk(KERN_WARNING "ipt_ecn: can't match TCP bits in rule for"
+		       " non-tcp packets\n");
+		return false;
+	}
+
+	return true;
+}
+
+static struct xt_match ecn_mt_reg __read_mostly = {
+	.name		= "ecn",
+	.family		= NFPROTO_IPV4,
+	.match		= ecn_mt,
+	.matchsize	= sizeof(struct ipt_ecn_info),
+	.checkentry	= ecn_mt_check,
+	.me		= THIS_MODULE,
+};
+
+static int __init ecn_mt_init(void)
+{
+	return xt_register_match(&ecn_mt_reg);
+}
+
+static void __exit ecn_mt_exit(void)
+{
+	xt_unregister_match(&ecn_mt_reg);
+}
+
+module_init(ecn_mt_init);
+module_exit(ecn_mt_exit);
diff --git a/net/ipv4/netfilter/ipt_ttl.c b/net/ipv4/netfilter/ipt_ttl.c
new file mode 100644
index 0000000..297f1cb
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_ttl.c
@@ -0,0 +1,63 @@
+/* IP tables module for matching the value of the TTL
+ *
+ * (C) 2000,2001 by Harald Welte <laforge@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ip.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+
+#include <linux/netfilter_ipv4/ipt_ttl.h>
+#include <linux/netfilter/x_tables.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
+MODULE_DESCRIPTION("Xtables: IPv4 TTL field match");
+MODULE_LICENSE("GPL");
+
+static bool ttl_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+{
+	const struct ipt_ttl_info *info = par->matchinfo;
+	const u8 ttl = ip_hdr(skb)->ttl;
+
+	switch (info->mode) {
+		case IPT_TTL_EQ:
+			return ttl == info->ttl;
+		case IPT_TTL_NE:
+			return ttl != info->ttl;
+		case IPT_TTL_LT:
+			return ttl < info->ttl;
+		case IPT_TTL_GT:
+			return ttl > info->ttl;
+		default:
+			printk(KERN_WARNING "ipt_ttl: unknown mode %d\n",
+				info->mode);
+			return false;
+	}
+
+	return false;
+}
+
+static struct xt_match ttl_mt_reg __read_mostly = {
+	.name		= "ttl",
+	.family		= NFPROTO_IPV4,
+	.match		= ttl_mt,
+	.matchsize	= sizeof(struct ipt_ttl_info),
+	.me		= THIS_MODULE,
+};
+
+static int __init ttl_mt_init(void)
+{
+	return xt_register_match(&ttl_mt_reg);
+}
+
+static void __exit ttl_mt_exit(void)
+{
+	xt_unregister_match(&ttl_mt_reg);
+}
+
+module_init(ttl_mt_init);
+module_exit(ttl_mt_exit);
diff --git a/net/ipv4/netfilter/iptable_filter.c b/net/ipv4/netfilter/iptable_filter.c
new file mode 100644
index 0000000..c922431
--- /dev/null
+++ b/net/ipv4/netfilter/iptable_filter.c
@@ -0,0 +1,190 @@
+/*
+ * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
+ *
+ * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/ip.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("iptables filter table");
+
+#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \
+			    (1 << NF_INET_FORWARD) | \
+			    (1 << NF_INET_LOCAL_OUT))
+
+static struct
+{
+	struct ipt_replace repl;
+	struct ipt_standard entries[3];
+	struct ipt_error term;
+} initial_table __net_initdata = {
+	.repl = {
+		.name = "filter",
+		.valid_hooks = FILTER_VALID_HOOKS,
+		.num_entries = 4,
+		.size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
+		.hook_entry = {
+			[NF_INET_LOCAL_IN] = 0,
+			[NF_INET_FORWARD] = sizeof(struct ipt_standard),
+			[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2,
+		},
+		.underflow = {
+			[NF_INET_LOCAL_IN] = 0,
+			[NF_INET_FORWARD] = sizeof(struct ipt_standard),
+			[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2,
+		},
+	},
+	.entries = {
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_IN */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* FORWARD */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
+	},
+	.term = IPT_ERROR_INIT,			/* ERROR */
+};
+
+static struct xt_table packet_filter = {
+	.name		= "filter",
+	.valid_hooks	= FILTER_VALID_HOOKS,
+	.lock		= __RW_LOCK_UNLOCKED(packet_filter.lock),
+	.me		= THIS_MODULE,
+	.af		= AF_INET,
+};
+
+/* The work comes in here from netfilter.c. */
+static unsigned int
+ipt_local_in_hook(unsigned int hook,
+		  struct sk_buff *skb,
+		  const struct net_device *in,
+		  const struct net_device *out,
+		  int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_filter);
+}
+
+static unsigned int
+ipt_hook(unsigned int hook,
+	 struct sk_buff *skb,
+	 const struct net_device *in,
+	 const struct net_device *out,
+	 int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_filter);
+}
+
+static unsigned int
+ipt_local_out_hook(unsigned int hook,
+		   struct sk_buff *skb,
+		   const struct net_device *in,
+		   const struct net_device *out,
+		   int (*okfn)(struct sk_buff *))
+{
+	/* root is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr) ||
+	    ip_hdrlen(skb) < sizeof(struct iphdr)) {
+		if (net_ratelimit())
+			printk("iptable_filter: ignoring short SOCK_RAW "
+			       "packet.\n");
+		return NF_ACCEPT;
+	}
+
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(out)->ipv4.iptable_filter);
+}
+
+static struct nf_hook_ops ipt_ops[] __read_mostly = {
+	{
+		.hook		= ipt_local_in_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_FILTER,
+	},
+	{
+		.hook		= ipt_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_FORWARD,
+		.priority	= NF_IP_PRI_FILTER,
+	},
+	{
+		.hook		= ipt_local_out_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_OUT,
+		.priority	= NF_IP_PRI_FILTER,
+	},
+};
+
+/* Default to forward because I got too much mail already. */
+static int forward = NF_ACCEPT;
+module_param(forward, bool, 0000);
+
+static int __net_init iptable_filter_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_filter =
+		ipt_register_table(net, &packet_filter, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_filter))
+		return PTR_ERR(net->ipv4.iptable_filter);
+	return 0;
+}
+
+static void __net_exit iptable_filter_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_filter);
+}
+
+static struct pernet_operations iptable_filter_net_ops = {
+	.init = iptable_filter_net_init,
+	.exit = iptable_filter_net_exit,
+};
+
+static int __init iptable_filter_init(void)
+{
+	int ret;
+
+	if (forward < 0 || forward > NF_MAX_VERDICT) {
+		printk("iptables forward must be 0 or 1\n");
+		return -EINVAL;
+	}
+
+	/* Entry 1 is the FORWARD hook */
+	initial_table.entries[1].target.verdict = -forward - 1;
+
+	ret = register_pernet_subsys(&iptable_filter_net_ops);
+	if (ret < 0)
+		return ret;
+
+	/* Register hooks */
+	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	if (ret < 0)
+		goto cleanup_table;
+
+	return ret;
+
+ cleanup_table:
+	unregister_pernet_subsys(&iptable_filter_net_ops);
+	return ret;
+}
+
+static void __exit iptable_filter_fini(void)
+{
+	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	unregister_pernet_subsys(&iptable_filter_net_ops);
+}
+
+module_init(iptable_filter_init);
+module_exit(iptable_filter_fini);
diff --git a/net/ipv4/netfilter/iptable_mangle.c b/net/ipv4/netfilter/iptable_mangle.c
new file mode 100644
index 0000000..69f2c42
--- /dev/null
+++ b/net/ipv4/netfilter/iptable_mangle.c
@@ -0,0 +1,251 @@
+/*
+ * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x.
+ *
+ * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/route.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("iptables mangle table");
+
+#define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \
+			    (1 << NF_INET_LOCAL_IN) | \
+			    (1 << NF_INET_FORWARD) | \
+			    (1 << NF_INET_LOCAL_OUT) | \
+			    (1 << NF_INET_POST_ROUTING))
+
+/* Ouch - five different hooks? Maybe this should be a config option..... -- BC */
+static struct
+{
+	struct ipt_replace repl;
+	struct ipt_standard entries[5];
+	struct ipt_error term;
+} initial_table __net_initdata = {
+	.repl = {
+		.name = "mangle",
+		.valid_hooks = MANGLE_VALID_HOOKS,
+		.num_entries = 6,
+		.size = sizeof(struct ipt_standard) * 5 + sizeof(struct ipt_error),
+		.hook_entry = {
+			[NF_INET_PRE_ROUTING] 	= 0,
+			[NF_INET_LOCAL_IN] 	= sizeof(struct ipt_standard),
+			[NF_INET_FORWARD] 	= sizeof(struct ipt_standard) * 2,
+			[NF_INET_LOCAL_OUT] 	= sizeof(struct ipt_standard) * 3,
+			[NF_INET_POST_ROUTING] 	= sizeof(struct ipt_standard) * 4,
+		},
+		.underflow = {
+			[NF_INET_PRE_ROUTING] 	= 0,
+			[NF_INET_LOCAL_IN] 	= sizeof(struct ipt_standard),
+			[NF_INET_FORWARD] 	= sizeof(struct ipt_standard) * 2,
+			[NF_INET_LOCAL_OUT] 	= sizeof(struct ipt_standard) * 3,
+			[NF_INET_POST_ROUTING]	= sizeof(struct ipt_standard) * 4,
+		},
+	},
+	.entries = {
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* PRE_ROUTING */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_IN */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* FORWARD */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* POST_ROUTING */
+	},
+	.term = IPT_ERROR_INIT,			/* ERROR */
+};
+
+static struct xt_table packet_mangler = {
+	.name		= "mangle",
+	.valid_hooks	= MANGLE_VALID_HOOKS,
+	.lock		= __RW_LOCK_UNLOCKED(packet_mangler.lock),
+	.me		= THIS_MODULE,
+	.af		= AF_INET,
+};
+
+/* The work comes in here from netfilter.c. */
+static unsigned int
+ipt_pre_routing_hook(unsigned int hook,
+		     struct sk_buff *skb,
+		     const struct net_device *in,
+		     const struct net_device *out,
+		     int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_mangle);
+}
+
+static unsigned int
+ipt_post_routing_hook(unsigned int hook,
+		      struct sk_buff *skb,
+		      const struct net_device *in,
+		      const struct net_device *out,
+		      int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(out)->ipv4.iptable_mangle);
+}
+
+static unsigned int
+ipt_local_in_hook(unsigned int hook,
+		  struct sk_buff *skb,
+		  const struct net_device *in,
+		  const struct net_device *out,
+		  int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_mangle);
+}
+
+static unsigned int
+ipt_forward_hook(unsigned int hook,
+	 struct sk_buff *skb,
+	 const struct net_device *in,
+	 const struct net_device *out,
+	 int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_mangle);
+}
+
+static unsigned int
+ipt_local_hook(unsigned int hook,
+		   struct sk_buff *skb,
+		   const struct net_device *in,
+		   const struct net_device *out,
+		   int (*okfn)(struct sk_buff *))
+{
+	unsigned int ret;
+	const struct iphdr *iph;
+	u_int8_t tos;
+	__be32 saddr, daddr;
+	u_int32_t mark;
+
+	/* root is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr)
+	    || ip_hdrlen(skb) < sizeof(struct iphdr)) {
+		if (net_ratelimit())
+			printk("iptable_mangle: ignoring short SOCK_RAW "
+			       "packet.\n");
+		return NF_ACCEPT;
+	}
+
+	/* Save things which could affect route */
+	mark = skb->mark;
+	iph = ip_hdr(skb);
+	saddr = iph->saddr;
+	daddr = iph->daddr;
+	tos = iph->tos;
+
+	ret = ipt_do_table(skb, hook, in, out,
+			   dev_net(out)->ipv4.iptable_mangle);
+	/* Reroute for ANY change. */
+	if (ret != NF_DROP && ret != NF_STOLEN && ret != NF_QUEUE) {
+		iph = ip_hdr(skb);
+
+		if (iph->saddr != saddr ||
+		    iph->daddr != daddr ||
+		    skb->mark != mark ||
+		    iph->tos != tos)
+			if (ip_route_me_harder(skb, RTN_UNSPEC))
+				ret = NF_DROP;
+	}
+
+	return ret;
+}
+
+static struct nf_hook_ops ipt_ops[] __read_mostly = {
+	{
+		.hook		= ipt_pre_routing_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_PRE_ROUTING,
+		.priority	= NF_IP_PRI_MANGLE,
+	},
+	{
+		.hook		= ipt_local_in_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_MANGLE,
+	},
+	{
+		.hook		= ipt_forward_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_FORWARD,
+		.priority	= NF_IP_PRI_MANGLE,
+	},
+	{
+		.hook		= ipt_local_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_OUT,
+		.priority	= NF_IP_PRI_MANGLE,
+	},
+	{
+		.hook		= ipt_post_routing_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_POST_ROUTING,
+		.priority	= NF_IP_PRI_MANGLE,
+	},
+};
+
+static int __net_init iptable_mangle_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_mangle =
+		ipt_register_table(net, &packet_mangler, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_mangle))
+		return PTR_ERR(net->ipv4.iptable_mangle);
+	return 0;
+}
+
+static void __net_exit iptable_mangle_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_mangle);
+}
+
+static struct pernet_operations iptable_mangle_net_ops = {
+	.init = iptable_mangle_net_init,
+	.exit = iptable_mangle_net_exit,
+};
+
+static int __init iptable_mangle_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&iptable_mangle_net_ops);
+	if (ret < 0)
+		return ret;
+
+	/* Register hooks */
+	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	if (ret < 0)
+		goto cleanup_table;
+
+	return ret;
+
+ cleanup_table:
+	unregister_pernet_subsys(&iptable_mangle_net_ops);
+	return ret;
+}
+
+static void __exit iptable_mangle_fini(void)
+{
+	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	unregister_pernet_subsys(&iptable_mangle_net_ops);
+}
+
+module_init(iptable_mangle_init);
+module_exit(iptable_mangle_fini);
diff --git a/net/ipv4/netfilter/iptable_raw.c b/net/ipv4/netfilter/iptable_raw.c
new file mode 100644
index 0000000..8faebfe
--- /dev/null
+++ b/net/ipv4/netfilter/iptable_raw.c
@@ -0,0 +1,144 @@
+/*
+ * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT .
+ *
+ * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ */
+#include <linux/module.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/ip.h>
+
+#define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
+
+static struct
+{
+	struct ipt_replace repl;
+	struct ipt_standard entries[2];
+	struct ipt_error term;
+} initial_table __net_initdata = {
+	.repl = {
+		.name = "raw",
+		.valid_hooks = RAW_VALID_HOOKS,
+		.num_entries = 3,
+		.size = sizeof(struct ipt_standard) * 2 + sizeof(struct ipt_error),
+		.hook_entry = {
+			[NF_INET_PRE_ROUTING] = 0,
+			[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard)
+		},
+		.underflow = {
+			[NF_INET_PRE_ROUTING] = 0,
+			[NF_INET_LOCAL_OUT]  = sizeof(struct ipt_standard)
+		},
+	},
+	.entries = {
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* PRE_ROUTING */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
+	},
+	.term = IPT_ERROR_INIT,			/* ERROR */
+};
+
+static struct xt_table packet_raw = {
+	.name = "raw",
+	.valid_hooks =  RAW_VALID_HOOKS,
+	.lock = __RW_LOCK_UNLOCKED(packet_raw.lock),
+	.me = THIS_MODULE,
+	.af = AF_INET,
+};
+
+/* The work comes in here from netfilter.c. */
+static unsigned int
+ipt_hook(unsigned int hook,
+	 struct sk_buff *skb,
+	 const struct net_device *in,
+	 const struct net_device *out,
+	 int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_raw);
+}
+
+static unsigned int
+ipt_local_hook(unsigned int hook,
+	       struct sk_buff *skb,
+	       const struct net_device *in,
+	       const struct net_device *out,
+	       int (*okfn)(struct sk_buff *))
+{
+	/* root is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr) ||
+	    ip_hdrlen(skb) < sizeof(struct iphdr)) {
+		if (net_ratelimit())
+			printk("iptable_raw: ignoring short SOCK_RAW "
+			       "packet.\n");
+		return NF_ACCEPT;
+	}
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(out)->ipv4.iptable_raw);
+}
+
+/* 'raw' is the very first table. */
+static struct nf_hook_ops ipt_ops[] __read_mostly = {
+	{
+		.hook = ipt_hook,
+		.pf = PF_INET,
+		.hooknum = NF_INET_PRE_ROUTING,
+		.priority = NF_IP_PRI_RAW,
+		.owner = THIS_MODULE,
+	},
+	{
+		.hook = ipt_local_hook,
+		.pf = PF_INET,
+		.hooknum = NF_INET_LOCAL_OUT,
+		.priority = NF_IP_PRI_RAW,
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __net_init iptable_raw_net_init(struct net *net)
+{
+	/* Register table */
+	net->ipv4.iptable_raw =
+		ipt_register_table(net, &packet_raw, &initial_table.repl);
+	if (IS_ERR(net->ipv4.iptable_raw))
+		return PTR_ERR(net->ipv4.iptable_raw);
+	return 0;
+}
+
+static void __net_exit iptable_raw_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_raw);
+}
+
+static struct pernet_operations iptable_raw_net_ops = {
+	.init = iptable_raw_net_init,
+	.exit = iptable_raw_net_exit,
+};
+
+static int __init iptable_raw_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&iptable_raw_net_ops);
+	if (ret < 0)
+		return ret;
+
+	/* Register hooks */
+	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	if (ret < 0)
+		goto cleanup_table;
+
+	return ret;
+
+ cleanup_table:
+	unregister_pernet_subsys(&iptable_raw_net_ops);
+	return ret;
+}
+
+static void __exit iptable_raw_fini(void)
+{
+	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	unregister_pernet_subsys(&iptable_raw_net_ops);
+}
+
+module_init(iptable_raw_init);
+module_exit(iptable_raw_fini);
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/netfilter/iptable_security.c b/net/ipv4/netfilter/iptable_security.c
new file mode 100644
index 0000000..36f3be3
--- /dev/null
+++ b/net/ipv4/netfilter/iptable_security.c
@@ -0,0 +1,180 @@
+/*
+ * "security" table
+ *
+ * This is for use by Mandatory Access Control (MAC) security models,
+ * which need to be able to manage security policy in separate context
+ * to DAC.
+ *
+ * Based on iptable_mangle.c
+ *
+ * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
+ * Copyright (C) 2000-2004 Netfilter Core Team <coreteam <at> netfilter.org>
+ * Copyright (C) 2008 Red Hat, Inc., James Morris <jmorris <at> redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/ip.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("James Morris <jmorris <at> redhat.com>");
+MODULE_DESCRIPTION("iptables security table, for MAC rules");
+
+#define SECURITY_VALID_HOOKS	(1 << NF_INET_LOCAL_IN) | \
+				(1 << NF_INET_FORWARD) | \
+				(1 << NF_INET_LOCAL_OUT)
+
+static struct
+{
+	struct ipt_replace repl;
+	struct ipt_standard entries[3];
+	struct ipt_error term;
+} initial_table __net_initdata = {
+	.repl = {
+		.name = "security",
+		.valid_hooks = SECURITY_VALID_HOOKS,
+		.num_entries = 4,
+		.size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
+		.hook_entry = {
+			[NF_INET_LOCAL_IN] 	= 0,
+			[NF_INET_FORWARD] 	= sizeof(struct ipt_standard),
+			[NF_INET_LOCAL_OUT] 	= sizeof(struct ipt_standard) * 2,
+		},
+		.underflow = {
+			[NF_INET_LOCAL_IN] 	= 0,
+			[NF_INET_FORWARD] 	= sizeof(struct ipt_standard),
+			[NF_INET_LOCAL_OUT] 	= sizeof(struct ipt_standard) * 2,
+		},
+	},
+	.entries = {
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_IN */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* FORWARD */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
+	},
+	.term = IPT_ERROR_INIT,			/* ERROR */
+};
+
+static struct xt_table security_table = {
+	.name		= "security",
+	.valid_hooks	= SECURITY_VALID_HOOKS,
+	.lock		= __RW_LOCK_UNLOCKED(security_table.lock),
+	.me		= THIS_MODULE,
+	.af		= AF_INET,
+};
+
+static unsigned int
+ipt_local_in_hook(unsigned int hook,
+		  struct sk_buff *skb,
+		  const struct net_device *in,
+		  const struct net_device *out,
+		  int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_security);
+}
+
+static unsigned int
+ipt_forward_hook(unsigned int hook,
+		 struct sk_buff *skb,
+		 const struct net_device *in,
+		 const struct net_device *out,
+		 int (*okfn)(struct sk_buff *))
+{
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(in)->ipv4.iptable_security);
+}
+
+static unsigned int
+ipt_local_out_hook(unsigned int hook,
+		   struct sk_buff *skb,
+		   const struct net_device *in,
+		   const struct net_device *out,
+		   int (*okfn)(struct sk_buff *))
+{
+	/* Somebody is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr)
+	    || ip_hdrlen(skb) < sizeof(struct iphdr)) {
+		if (net_ratelimit())
+			printk(KERN_INFO "iptable_security: ignoring short "
+			       "SOCK_RAW packet.\n");
+		return NF_ACCEPT;
+	}
+	return ipt_do_table(skb, hook, in, out,
+			    dev_net(out)->ipv4.iptable_security);
+}
+
+static struct nf_hook_ops ipt_ops[] __read_mostly = {
+	{
+		.hook		= ipt_local_in_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_SECURITY,
+	},
+	{
+		.hook		= ipt_forward_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_FORWARD,
+		.priority	= NF_IP_PRI_SECURITY,
+	},
+	{
+		.hook		= ipt_local_out_hook,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_OUT,
+		.priority	= NF_IP_PRI_SECURITY,
+	},
+};
+
+static int __net_init iptable_security_net_init(struct net *net)
+{
+	net->ipv4.iptable_security =
+		ipt_register_table(net, &security_table, &initial_table.repl);
+
+	if (IS_ERR(net->ipv4.iptable_security))
+		return PTR_ERR(net->ipv4.iptable_security);
+
+	return 0;
+}
+
+static void __net_exit iptable_security_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.iptable_security);
+}
+
+static struct pernet_operations iptable_security_net_ops = {
+	.init = iptable_security_net_init,
+	.exit = iptable_security_net_exit,
+};
+
+static int __init iptable_security_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&iptable_security_net_ops);
+        if (ret < 0)
+		return ret;
+
+	ret = nf_register_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	if (ret < 0)
+		goto cleanup_table;
+
+	return ret;
+
+cleanup_table:
+	unregister_pernet_subsys(&iptable_security_net_ops);
+	return ret;
+}
+
+static void __exit iptable_security_fini(void)
+{
+	nf_unregister_hooks(ipt_ops, ARRAY_SIZE(ipt_ops));
+	unregister_pernet_subsys(&iptable_security_net_ops);
+}
+
+module_init(iptable_security_init);
+module_exit(iptable_security_fini);
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
new file mode 100644
index 0000000..4a7c352
--- /dev/null
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -0,0 +1,456 @@
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/icmp.h>
+#include <linux/sysctl.h>
+#include <net/route.h>
+#include <net/ip.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+
+int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb,
+			      struct nf_conn *ct,
+			      enum ip_conntrack_info ctinfo);
+EXPORT_SYMBOL_GPL(nf_nat_seq_adjust_hook);
+
+static bool ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
+			      struct nf_conntrack_tuple *tuple)
+{
+	const __be32 *ap;
+	__be32 _addrs[2];
+	ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
+				sizeof(u_int32_t) * 2, _addrs);
+	if (ap == NULL)
+		return false;
+
+	tuple->src.u3.ip = ap[0];
+	tuple->dst.u3.ip = ap[1];
+
+	return true;
+}
+
+static bool ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
+			      const struct nf_conntrack_tuple *orig)
+{
+	tuple->src.u3.ip = orig->dst.u3.ip;
+	tuple->dst.u3.ip = orig->src.u3.ip;
+
+	return true;
+}
+
+static int ipv4_print_tuple(struct seq_file *s,
+			    const struct nf_conntrack_tuple *tuple)
+{
+	return seq_printf(s, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
+			  NIPQUAD(tuple->src.u3.ip),
+			  NIPQUAD(tuple->dst.u3.ip));
+}
+
+static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
+			    unsigned int *dataoff, u_int8_t *protonum)
+{
+	const struct iphdr *iph;
+	struct iphdr _iph;
+
+	iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph);
+	if (iph == NULL)
+		return -NF_DROP;
+
+	/* Conntrack defragments packets, we might still see fragments
+	 * inside ICMP packets though. */
+	if (iph->frag_off & htons(IP_OFFSET))
+		return -NF_DROP;
+
+	*dataoff = nhoff + (iph->ihl << 2);
+	*protonum = iph->protocol;
+
+	return NF_ACCEPT;
+}
+
+static unsigned int ipv4_confirm(unsigned int hooknum,
+				 struct sk_buff *skb,
+				 const struct net_device *in,
+				 const struct net_device *out,
+				 int (*okfn)(struct sk_buff *))
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	const struct nf_conn_help *help;
+	const struct nf_conntrack_helper *helper;
+	unsigned int ret;
+
+	/* This is where we call the helper: as the packet goes out. */
+	ct = nf_ct_get(skb, &ctinfo);
+	if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
+		goto out;
+
+	help = nfct_help(ct);
+	if (!help)
+		goto out;
+
+	/* rcu_read_lock()ed by nf_hook_slow */
+	helper = rcu_dereference(help->helper);
+	if (!helper)
+		goto out;
+
+	ret = helper->help(skb, skb_network_offset(skb) + ip_hdrlen(skb),
+			   ct, ctinfo);
+	if (ret != NF_ACCEPT)
+		return ret;
+
+	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status)) {
+		typeof(nf_nat_seq_adjust_hook) seq_adjust;
+
+		seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook);
+		if (!seq_adjust || !seq_adjust(skb, ct, ctinfo))
+			return NF_DROP;
+	}
+out:
+	/* We've seen it coming out the other side: confirm it */
+	return nf_conntrack_confirm(skb);
+}
+
+static unsigned int ipv4_conntrack_in(unsigned int hooknum,
+				      struct sk_buff *skb,
+				      const struct net_device *in,
+				      const struct net_device *out,
+				      int (*okfn)(struct sk_buff *))
+{
+	return nf_conntrack_in(dev_net(in), PF_INET, hooknum, skb);
+}
+
+static unsigned int ipv4_conntrack_local(unsigned int hooknum,
+					 struct sk_buff *skb,
+					 const struct net_device *in,
+					 const struct net_device *out,
+					 int (*okfn)(struct sk_buff *))
+{
+	/* root is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr) ||
+	    ip_hdrlen(skb) < sizeof(struct iphdr)) {
+		if (net_ratelimit())
+			printk("ipt_hook: happy cracking.\n");
+		return NF_ACCEPT;
+	}
+	return nf_conntrack_in(dev_net(out), PF_INET, hooknum, skb);
+}
+
+/* Connection tracking may drop packets, but never alters them, so
+   make it the first hook. */
+static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = {
+	{
+		.hook		= ipv4_conntrack_in,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_PRE_ROUTING,
+		.priority	= NF_IP_PRI_CONNTRACK,
+	},
+	{
+		.hook		= ipv4_conntrack_local,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_OUT,
+		.priority	= NF_IP_PRI_CONNTRACK,
+	},
+	{
+		.hook		= ipv4_confirm,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_POST_ROUTING,
+		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
+	},
+	{
+		.hook		= ipv4_confirm,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_CONNTRACK_CONFIRM,
+	},
+};
+
+#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
+static int log_invalid_proto_min = 0;
+static int log_invalid_proto_max = 255;
+
+static ctl_table ip_ct_sysctl_table[] = {
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_MAX,
+		.procname	= "ip_conntrack_max",
+		.data		= &nf_conntrack_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_COUNT,
+		.procname	= "ip_conntrack_count",
+		.data		= &init_net.ct.count,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_BUCKETS,
+		.procname	= "ip_conntrack_buckets",
+		.data		= &nf_conntrack_htable_size,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0444,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_CHECKSUM,
+		.procname	= "ip_conntrack_checksum",
+		.data		= &init_net.ct.sysctl_checksum,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_LOG_INVALID,
+		.procname	= "ip_conntrack_log_invalid",
+		.data		= &init_net.ct.sysctl_log_invalid,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &log_invalid_proto_min,
+		.extra2		= &log_invalid_proto_max,
+	},
+	{
+		.ctl_name	= 0
+	}
+};
+#endif /* CONFIG_SYSCTL && CONFIG_NF_CONNTRACK_PROC_COMPAT */
+
+/* Fast function for those who don't want to parse /proc (and I don't
+   blame them). */
+/* Reversing the socket's dst/src point of view gives us the reply
+   mapping. */
+static int
+getorigdst(struct sock *sk, int optval, void __user *user, int *len)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct nf_conntrack_tuple_hash *h;
+	struct nf_conntrack_tuple tuple;
+
+	memset(&tuple, 0, sizeof(tuple));
+	tuple.src.u3.ip = inet->rcv_saddr;
+	tuple.src.u.tcp.port = inet->sport;
+	tuple.dst.u3.ip = inet->daddr;
+	tuple.dst.u.tcp.port = inet->dport;
+	tuple.src.l3num = PF_INET;
+	tuple.dst.protonum = IPPROTO_TCP;
+
+	/* We only do TCP at the moment: is there a better way? */
+	if (strcmp(sk->sk_prot->name, "TCP")) {
+		pr_debug("SO_ORIGINAL_DST: Not a TCP socket\n");
+		return -ENOPROTOOPT;
+	}
+
+	if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
+		pr_debug("SO_ORIGINAL_DST: len %d not %Zu\n",
+			 *len, sizeof(struct sockaddr_in));
+		return -EINVAL;
+	}
+
+	h = nf_conntrack_find_get(sock_net(sk), &tuple);
+	if (h) {
+		struct sockaddr_in sin;
+		struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
+
+		sin.sin_family = AF_INET;
+		sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
+			.tuple.dst.u.tcp.port;
+		sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
+			.tuple.dst.u3.ip;
+		memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
+
+		pr_debug("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
+			 NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+		nf_ct_put(ct);
+		if (copy_to_user(user, &sin, sizeof(sin)) != 0)
+			return -EFAULT;
+		else
+			return 0;
+	}
+	pr_debug("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
+		 NIPQUAD(tuple.src.u3.ip), ntohs(tuple.src.u.tcp.port),
+		 NIPQUAD(tuple.dst.u3.ip), ntohs(tuple.dst.u.tcp.port));
+	return -ENOENT;
+}
+
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
+				const struct nf_conntrack_tuple *tuple)
+{
+	NLA_PUT_BE32(skb, CTA_IP_V4_SRC, tuple->src.u3.ip);
+	NLA_PUT_BE32(skb, CTA_IP_V4_DST, tuple->dst.u3.ip);
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static const struct nla_policy ipv4_nla_policy[CTA_IP_MAX+1] = {
+	[CTA_IP_V4_SRC]	= { .type = NLA_U32 },
+	[CTA_IP_V4_DST]	= { .type = NLA_U32 },
+};
+
+static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
+				struct nf_conntrack_tuple *t)
+{
+	if (!tb[CTA_IP_V4_SRC] || !tb[CTA_IP_V4_DST])
+		return -EINVAL;
+
+	t->src.u3.ip = nla_get_be32(tb[CTA_IP_V4_SRC]);
+	t->dst.u3.ip = nla_get_be32(tb[CTA_IP_V4_DST]);
+
+	return 0;
+}
+#endif
+
+static struct nf_sockopt_ops so_getorigdst = {
+	.pf		= PF_INET,
+	.get_optmin	= SO_ORIGINAL_DST,
+	.get_optmax	= SO_ORIGINAL_DST+1,
+	.get		= &getorigdst,
+	.owner		= THIS_MODULE,
+};
+
+struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
+	.l3proto	 = PF_INET,
+	.name		 = "ipv4",
+	.pkt_to_tuple	 = ipv4_pkt_to_tuple,
+	.invert_tuple	 = ipv4_invert_tuple,
+	.print_tuple	 = ipv4_print_tuple,
+	.get_l4proto	 = ipv4_get_l4proto,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.tuple_to_nlattr = ipv4_tuple_to_nlattr,
+	.nlattr_to_tuple = ipv4_nlattr_to_tuple,
+	.nla_policy	 = ipv4_nla_policy,
+#endif
+#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
+	.ctl_table_path  = nf_net_ipv4_netfilter_sysctl_path,
+	.ctl_table	 = ip_ct_sysctl_table,
+#endif
+	.me		 = THIS_MODULE,
+};
+
+module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint,
+		  &nf_conntrack_htable_size, 0600);
+
+MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
+MODULE_ALIAS("ip_conntrack");
+MODULE_LICENSE("GPL");
+
+static int __init nf_conntrack_l3proto_ipv4_init(void)
+{
+	int ret = 0;
+
+	need_conntrack();
+	nf_defrag_ipv4_enable();
+
+	ret = nf_register_sockopt(&so_getorigdst);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to register netfilter socket option\n");
+		return ret;
+	}
+
+	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp4);
+	if (ret < 0) {
+		printk("nf_conntrack_ipv4: can't register tcp.\n");
+		goto cleanup_sockopt;
+	}
+
+	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp4);
+	if (ret < 0) {
+		printk("nf_conntrack_ipv4: can't register udp.\n");
+		goto cleanup_tcp;
+	}
+
+	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmp);
+	if (ret < 0) {
+		printk("nf_conntrack_ipv4: can't register icmp.\n");
+		goto cleanup_udp;
+	}
+
+	ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
+	if (ret < 0) {
+		printk("nf_conntrack_ipv4: can't register ipv4\n");
+		goto cleanup_icmp;
+	}
+
+	ret = nf_register_hooks(ipv4_conntrack_ops,
+				ARRAY_SIZE(ipv4_conntrack_ops));
+	if (ret < 0) {
+		printk("nf_conntrack_ipv4: can't register hooks.\n");
+		goto cleanup_ipv4;
+	}
+#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
+	ret = nf_conntrack_ipv4_compat_init();
+	if (ret < 0)
+		goto cleanup_hooks;
+#endif
+	return ret;
+#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
+ cleanup_hooks:
+	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
+#endif
+ cleanup_ipv4:
+	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
+ cleanup_icmp:
+	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
+ cleanup_udp:
+	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
+ cleanup_tcp:
+	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
+ cleanup_sockopt:
+	nf_unregister_sockopt(&so_getorigdst);
+	return ret;
+}
+
+static void __exit nf_conntrack_l3proto_ipv4_fini(void)
+{
+	synchronize_net();
+#if defined(CONFIG_PROC_FS) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
+	nf_conntrack_ipv4_compat_fini();
+#endif
+	nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
+	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
+	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmp);
+	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp4);
+	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp4);
+	nf_unregister_sockopt(&so_getorigdst);
+}
+
+module_init(nf_conntrack_l3proto_ipv4_init);
+module_exit(nf_conntrack_l3proto_ipv4_fini);
+
+void need_ipv4_conntrack(void)
+{
+	return;
+}
+EXPORT_SYMBOL_GPL(need_ipv4_conntrack);
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
new file mode 100644
index 0000000..313ebf0
--- /dev/null
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
@@ -0,0 +1,425 @@
+/* ip_conntrack proc compat - based on ip_conntrack_standalone.c
+ *
+ * (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/percpu.h>
+#include <net/net_namespace.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_acct.h>
+
+struct ct_iter_state {
+	struct seq_net_private p;
+	unsigned int bucket;
+};
+
+static struct hlist_node *ct_get_first(struct seq_file *seq)
+{
+	struct net *net = seq_file_net(seq);
+	struct ct_iter_state *st = seq->private;
+	struct hlist_node *n;
+
+	for (st->bucket = 0;
+	     st->bucket < nf_conntrack_htable_size;
+	     st->bucket++) {
+		n = rcu_dereference(net->ct.hash[st->bucket].first);
+		if (n)
+			return n;
+	}
+	return NULL;
+}
+
+static struct hlist_node *ct_get_next(struct seq_file *seq,
+				      struct hlist_node *head)
+{
+	struct net *net = seq_file_net(seq);
+	struct ct_iter_state *st = seq->private;
+
+	head = rcu_dereference(head->next);
+	while (head == NULL) {
+		if (++st->bucket >= nf_conntrack_htable_size)
+			return NULL;
+		head = rcu_dereference(net->ct.hash[st->bucket].first);
+	}
+	return head;
+}
+
+static struct hlist_node *ct_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct hlist_node *head = ct_get_first(seq);
+
+	if (head)
+		while (pos && (head = ct_get_next(seq, head)))
+			pos--;
+	return pos ? NULL : head;
+}
+
+static void *ct_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
+{
+	rcu_read_lock();
+	return ct_get_idx(seq, *pos);
+}
+
+static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return ct_get_next(s, v);
+}
+
+static void ct_seq_stop(struct seq_file *s, void *v)
+	__releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static int ct_seq_show(struct seq_file *s, void *v)
+{
+	const struct nf_conntrack_tuple_hash *hash = v;
+	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(hash);
+	const struct nf_conntrack_l3proto *l3proto;
+	const struct nf_conntrack_l4proto *l4proto;
+
+	NF_CT_ASSERT(ct);
+
+	/* we only want to print DIR_ORIGINAL */
+	if (NF_CT_DIRECTION(hash))
+		return 0;
+	if (nf_ct_l3num(ct) != AF_INET)
+		return 0;
+
+	l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));
+	NF_CT_ASSERT(l3proto);
+	l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
+	NF_CT_ASSERT(l4proto);
+
+	if (seq_printf(s, "%-8s %u %ld ",
+		      l4proto->name, nf_ct_protonum(ct),
+		      timer_pending(&ct->timeout)
+		      ? (long)(ct->timeout.expires - jiffies)/HZ : 0) != 0)
+		return -ENOSPC;
+
+	if (l4proto->print_conntrack && l4proto->print_conntrack(s, ct))
+		return -ENOSPC;
+
+	if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+			l3proto, l4proto))
+		return -ENOSPC;
+
+	if (seq_print_acct(s, ct, IP_CT_DIR_ORIGINAL))
+		return -ENOSPC;
+
+	if (!(test_bit(IPS_SEEN_REPLY_BIT, &ct->status)))
+		if (seq_printf(s, "[UNREPLIED] "))
+			return -ENOSPC;
+
+	if (print_tuple(s, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
+			l3proto, l4proto))
+		return -ENOSPC;
+
+	if (seq_print_acct(s, ct, IP_CT_DIR_REPLY))
+		return -ENOSPC;
+
+	if (test_bit(IPS_ASSURED_BIT, &ct->status))
+		if (seq_printf(s, "[ASSURED] "))
+			return -ENOSPC;
+
+#ifdef CONFIG_NF_CONNTRACK_MARK
+	if (seq_printf(s, "mark=%u ", ct->mark))
+		return -ENOSPC;
+#endif
+
+#ifdef CONFIG_NF_CONNTRACK_SECMARK
+	if (seq_printf(s, "secmark=%u ", ct->secmark))
+		return -ENOSPC;
+#endif
+
+	if (seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use)))
+		return -ENOSPC;
+
+	return 0;
+}
+
+static const struct seq_operations ct_seq_ops = {
+	.start = ct_seq_start,
+	.next  = ct_seq_next,
+	.stop  = ct_seq_stop,
+	.show  = ct_seq_show
+};
+
+static int ct_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &ct_seq_ops,
+			    sizeof(struct ct_iter_state));
+}
+
+static const struct file_operations ct_file_ops = {
+	.owner   = THIS_MODULE,
+	.open    = ct_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release_net,
+};
+
+/* expects */
+struct ct_expect_iter_state {
+	struct seq_net_private p;
+	unsigned int bucket;
+};
+
+static struct hlist_node *ct_expect_get_first(struct seq_file *seq)
+{
+	struct net *net = seq_file_net(seq);
+	struct ct_expect_iter_state *st = seq->private;
+	struct hlist_node *n;
+
+	for (st->bucket = 0; st->bucket < nf_ct_expect_hsize; st->bucket++) {
+		n = rcu_dereference(net->ct.expect_hash[st->bucket].first);
+		if (n)
+			return n;
+	}
+	return NULL;
+}
+
+static struct hlist_node *ct_expect_get_next(struct seq_file *seq,
+					     struct hlist_node *head)
+{
+	struct net *net = seq_file_net(seq);
+	struct ct_expect_iter_state *st = seq->private;
+
+	head = rcu_dereference(head->next);
+	while (head == NULL) {
+		if (++st->bucket >= nf_ct_expect_hsize)
+			return NULL;
+		head = rcu_dereference(net->ct.expect_hash[st->bucket].first);
+	}
+	return head;
+}
+
+static struct hlist_node *ct_expect_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct hlist_node *head = ct_expect_get_first(seq);
+
+	if (head)
+		while (pos && (head = ct_expect_get_next(seq, head)))
+			pos--;
+	return pos ? NULL : head;
+}
+
+static void *exp_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
+{
+	rcu_read_lock();
+	return ct_expect_get_idx(seq, *pos);
+}
+
+static void *exp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	(*pos)++;
+	return ct_expect_get_next(seq, v);
+}
+
+static void exp_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
+{
+	rcu_read_unlock();
+}
+
+static int exp_seq_show(struct seq_file *s, void *v)
+{
+	struct nf_conntrack_expect *exp;
+	const struct hlist_node *n = v;
+
+	exp = hlist_entry(n, struct nf_conntrack_expect, hnode);
+
+	if (exp->tuple.src.l3num != AF_INET)
+		return 0;
+
+	if (exp->timeout.function)
+		seq_printf(s, "%ld ", timer_pending(&exp->timeout)
+			   ? (long)(exp->timeout.expires - jiffies)/HZ : 0);
+	else
+		seq_printf(s, "- ");
+
+	seq_printf(s, "proto=%u ", exp->tuple.dst.protonum);
+
+	print_tuple(s, &exp->tuple,
+		    __nf_ct_l3proto_find(exp->tuple.src.l3num),
+		    __nf_ct_l4proto_find(exp->tuple.src.l3num,
+					 exp->tuple.dst.protonum));
+	return seq_putc(s, '\n');
+}
+
+static const struct seq_operations exp_seq_ops = {
+	.start = exp_seq_start,
+	.next = exp_seq_next,
+	.stop = exp_seq_stop,
+	.show = exp_seq_show
+};
+
+static int exp_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &exp_seq_ops,
+			    sizeof(struct ct_expect_iter_state));
+}
+
+static const struct file_operations ip_exp_file_ops = {
+	.owner   = THIS_MODULE,
+	.open    = exp_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release_net,
+};
+
+static void *ct_cpu_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct net *net = seq_file_net(seq);
+	int cpu;
+
+	if (*pos == 0)
+		return SEQ_START_TOKEN;
+
+	for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
+		if (!cpu_possible(cpu))
+			continue;
+		*pos = cpu+1;
+		return per_cpu_ptr(net->ct.stat, cpu);
+	}
+
+	return NULL;
+}
+
+static void *ct_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct net *net = seq_file_net(seq);
+	int cpu;
+
+	for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
+		if (!cpu_possible(cpu))
+			continue;
+		*pos = cpu+1;
+		return per_cpu_ptr(net->ct.stat, cpu);
+	}
+
+	return NULL;
+}
+
+static void ct_cpu_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static int ct_cpu_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = seq_file_net(seq);
+	unsigned int nr_conntracks = atomic_read(&net->ct.count);
+	const struct ip_conntrack_stat *st = v;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, "entries  searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error  expect_new expect_create expect_delete\n");
+		return 0;
+	}
+
+	seq_printf(seq, "%08x  %08x %08x %08x %08x %08x %08x %08x "
+			"%08x %08x %08x %08x %08x  %08x %08x %08x \n",
+		   nr_conntracks,
+		   st->searched,
+		   st->found,
+		   st->new,
+		   st->invalid,
+		   st->ignore,
+		   st->delete,
+		   st->delete_list,
+		   st->insert,
+		   st->insert_failed,
+		   st->drop,
+		   st->early_drop,
+		   st->error,
+
+		   st->expect_new,
+		   st->expect_create,
+		   st->expect_delete
+		);
+	return 0;
+}
+
+static const struct seq_operations ct_cpu_seq_ops = {
+	.start  = ct_cpu_seq_start,
+	.next   = ct_cpu_seq_next,
+	.stop   = ct_cpu_seq_stop,
+	.show   = ct_cpu_seq_show,
+};
+
+static int ct_cpu_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &ct_cpu_seq_ops,
+			    sizeof(struct seq_net_private));
+}
+
+static const struct file_operations ct_cpu_seq_fops = {
+	.owner   = THIS_MODULE,
+	.open    = ct_cpu_seq_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release_net,
+};
+
+static int __net_init ip_conntrack_net_init(struct net *net)
+{
+	struct proc_dir_entry *proc, *proc_exp, *proc_stat;
+
+	proc = proc_net_fops_create(net, "ip_conntrack", 0440, &ct_file_ops);
+	if (!proc)
+		goto err1;
+
+	proc_exp = proc_net_fops_create(net, "ip_conntrack_expect", 0440,
+					&ip_exp_file_ops);
+	if (!proc_exp)
+		goto err2;
+
+	proc_stat = proc_create("ip_conntrack", S_IRUGO,
+				net->proc_net_stat, &ct_cpu_seq_fops);
+	if (!proc_stat)
+		goto err3;
+	return 0;
+
+err3:
+	proc_net_remove(net, "ip_conntrack_expect");
+err2:
+	proc_net_remove(net, "ip_conntrack");
+err1:
+	return -ENOMEM;
+}
+
+static void __net_exit ip_conntrack_net_exit(struct net *net)
+{
+	remove_proc_entry("ip_conntrack", net->proc_net_stat);
+	proc_net_remove(net, "ip_conntrack_expect");
+	proc_net_remove(net, "ip_conntrack");
+}
+
+static struct pernet_operations ip_conntrack_net_ops = {
+	.init = ip_conntrack_net_init,
+	.exit = ip_conntrack_net_exit,
+};
+
+int __init nf_conntrack_ipv4_compat_init(void)
+{
+	return register_pernet_subsys(&ip_conntrack_net_ops);
+}
+
+void __exit nf_conntrack_ipv4_compat_fini(void)
+{
+	unregister_pernet_subsys(&ip_conntrack_net_ops);
+}
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
new file mode 100644
index 0000000..625707a
--- /dev/null
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -0,0 +1,322 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/netfilter.h>
+#include <linux/in.h>
+#include <linux/icmp.h>
+#include <linux/seq_file.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_conntrack_tuple.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_log.h>
+
+static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;
+
+static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
+			      struct nf_conntrack_tuple *tuple)
+{
+	const struct icmphdr *hp;
+	struct icmphdr _hdr;
+
+	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
+	if (hp == NULL)
+		return false;
+
+	tuple->dst.u.icmp.type = hp->type;
+	tuple->src.u.icmp.id = hp->un.echo.id;
+	tuple->dst.u.icmp.code = hp->code;
+
+	return true;
+}
+
+/* Add 1; spaces filled with 0. */
+static const u_int8_t invmap[] = {
+	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
+	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
+	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
+	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
+	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
+	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
+	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
+	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
+};
+
+static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
+			      const struct nf_conntrack_tuple *orig)
+{
+	if (orig->dst.u.icmp.type >= sizeof(invmap)
+	    || !invmap[orig->dst.u.icmp.type])
+		return false;
+
+	tuple->src.u.icmp.id = orig->src.u.icmp.id;
+	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
+	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
+	return true;
+}
+
+/* Print out the per-protocol part of the tuple. */
+static int icmp_print_tuple(struct seq_file *s,
+			    const struct nf_conntrack_tuple *tuple)
+{
+	return seq_printf(s, "type=%u code=%u id=%u ",
+			  tuple->dst.u.icmp.type,
+			  tuple->dst.u.icmp.code,
+			  ntohs(tuple->src.u.icmp.id));
+}
+
+/* Returns verdict for packet, or -1 for invalid. */
+static int icmp_packet(struct nf_conn *ct,
+		       const struct sk_buff *skb,
+		       unsigned int dataoff,
+		       enum ip_conntrack_info ctinfo,
+		       u_int8_t pf,
+		       unsigned int hooknum)
+{
+	/* Try to delete connection immediately after all replies:
+	   won't actually vanish as we still have skb, and del_timer
+	   means this will only run once even if count hits zero twice
+	   (theoretically possible with SMP) */
+	if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
+		if (atomic_dec_and_test(&ct->proto.icmp.count))
+			nf_ct_kill_acct(ct, ctinfo, skb);
+	} else {
+		atomic_inc(&ct->proto.icmp.count);
+		nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, ct);
+		nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmp_timeout);
+	}
+
+	return NF_ACCEPT;
+}
+
+/* Called when a new connection for this protocol found. */
+static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb,
+		     unsigned int dataoff)
+{
+	static const u_int8_t valid_new[] = {
+		[ICMP_ECHO] = 1,
+		[ICMP_TIMESTAMP] = 1,
+		[ICMP_INFO_REQUEST] = 1,
+		[ICMP_ADDRESS] = 1
+	};
+
+	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new)
+	    || !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
+		/* Can't create a new ICMP `conn' with this. */
+		pr_debug("icmp: can't create new conn with type %u\n",
+			 ct->tuplehash[0].tuple.dst.u.icmp.type);
+		nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
+		return false;
+	}
+	atomic_set(&ct->proto.icmp.count, 0);
+	return true;
+}
+
+/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
+static int
+icmp_error_message(struct net *net, struct sk_buff *skb,
+		 enum ip_conntrack_info *ctinfo,
+		 unsigned int hooknum)
+{
+	struct nf_conntrack_tuple innertuple, origtuple;
+	const struct nf_conntrack_l4proto *innerproto;
+	const struct nf_conntrack_tuple_hash *h;
+
+	NF_CT_ASSERT(skb->nfct == NULL);
+
+	/* Are they talking about one of our connections? */
+	if (!nf_ct_get_tuplepr(skb,
+			       skb_network_offset(skb) + ip_hdrlen(skb)
+						       + sizeof(struct icmphdr),
+			       PF_INET, &origtuple)) {
+		pr_debug("icmp_error_message: failed to get tuple\n");
+		return -NF_ACCEPT;
+	}
+
+	/* rcu_read_lock()ed by nf_hook_slow */
+	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);
+
+	/* Ordinarily, we'd expect the inverted tupleproto, but it's
+	   been preserved inside the ICMP. */
+	if (!nf_ct_invert_tuple(&innertuple, &origtuple,
+				&nf_conntrack_l3proto_ipv4, innerproto)) {
+		pr_debug("icmp_error_message: no match\n");
+		return -NF_ACCEPT;
+	}
+
+	*ctinfo = IP_CT_RELATED;
+
+	h = nf_conntrack_find_get(net, &innertuple);
+	if (!h) {
+		pr_debug("icmp_error_message: no match\n");
+		return -NF_ACCEPT;
+	}
+
+	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
+		*ctinfo += IP_CT_IS_REPLY;
+
+	/* Update skb to refer to this connection */
+	skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
+	skb->nfctinfo = *ctinfo;
+	return -NF_ACCEPT;
+}
+
+/* Small and modified version of icmp_rcv */
+static int
+icmp_error(struct net *net, struct sk_buff *skb, unsigned int dataoff,
+	   enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
+{
+	const struct icmphdr *icmph;
+	struct icmphdr _ih;
+
+	/* Not enough header? */
+	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
+	if (icmph == NULL) {
+		if (LOG_INVALID(net, IPPROTO_ICMP))
+			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
+				      "nf_ct_icmp: short packet ");
+		return -NF_ACCEPT;
+	}
+
+	/* See ip_conntrack_proto_tcp.c */
+	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
+	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
+		if (LOG_INVALID(net, IPPROTO_ICMP))
+			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
+				      "nf_ct_icmp: bad HW ICMP checksum ");
+		return -NF_ACCEPT;
+	}
+
+	/*
+	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
+	 *
+	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
+	 *		  discarded.
+	 */
+	if (icmph->type > NR_ICMP_TYPES) {
+		if (LOG_INVALID(net, IPPROTO_ICMP))
+			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
+				      "nf_ct_icmp: invalid ICMP type ");
+		return -NF_ACCEPT;
+	}
+
+	/* Need to track icmp error message? */
+	if (icmph->type != ICMP_DEST_UNREACH
+	    && icmph->type != ICMP_SOURCE_QUENCH
+	    && icmph->type != ICMP_TIME_EXCEEDED
+	    && icmph->type != ICMP_PARAMETERPROB
+	    && icmph->type != ICMP_REDIRECT)
+		return NF_ACCEPT;
+
+	return icmp_error_message(net, skb, ctinfo, hooknum);
+}
+
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+static int icmp_tuple_to_nlattr(struct sk_buff *skb,
+				const struct nf_conntrack_tuple *t)
+{
+	NLA_PUT_BE16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id);
+	NLA_PUT_U8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type);
+	NLA_PUT_U8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code);
+
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+
+static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
+	[CTA_PROTO_ICMP_TYPE]	= { .type = NLA_U8 },
+	[CTA_PROTO_ICMP_CODE]	= { .type = NLA_U8 },
+	[CTA_PROTO_ICMP_ID]	= { .type = NLA_U16 },
+};
+
+static int icmp_nlattr_to_tuple(struct nlattr *tb[],
+				struct nf_conntrack_tuple *tuple)
+{
+	if (!tb[CTA_PROTO_ICMP_TYPE]
+	    || !tb[CTA_PROTO_ICMP_CODE]
+	    || !tb[CTA_PROTO_ICMP_ID])
+		return -EINVAL;
+
+	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
+	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
+	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
+
+	if (tuple->dst.u.icmp.type >= sizeof(invmap)
+	    || !invmap[tuple->dst.u.icmp.type])
+		return -EINVAL;
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table_header *icmp_sysctl_header;
+static struct ctl_table icmp_sysctl_table[] = {
+	{
+		.procname	= "nf_conntrack_icmp_timeout",
+		.data		= &nf_ct_icmp_timeout,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+	},
+	{
+		.ctl_name = 0
+	}
+};
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+static struct ctl_table icmp_compat_sysctl_table[] = {
+	{
+		.procname	= "ip_conntrack_icmp_timeout",
+		.data		= &nf_ct_icmp_timeout,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+	},
+	{
+		.ctl_name = 0
+	}
+};
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
+#endif /* CONFIG_SYSCTL */
+
+struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
+{
+	.l3proto		= PF_INET,
+	.l4proto		= IPPROTO_ICMP,
+	.name			= "icmp",
+	.pkt_to_tuple		= icmp_pkt_to_tuple,
+	.invert_tuple		= icmp_invert_tuple,
+	.print_tuple		= icmp_print_tuple,
+	.packet			= icmp_packet,
+	.new			= icmp_new,
+	.error			= icmp_error,
+	.destroy		= NULL,
+	.me			= NULL,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.tuple_to_nlattr	= icmp_tuple_to_nlattr,
+	.nlattr_to_tuple	= icmp_nlattr_to_tuple,
+	.nla_policy		= icmp_nla_policy,
+#endif
+#ifdef CONFIG_SYSCTL
+	.ctl_table_header	= &icmp_sysctl_header,
+	.ctl_table		= icmp_sysctl_table,
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+	.ctl_compat_table	= icmp_compat_sysctl_table,
+#endif
+#endif
+};
diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c
new file mode 100644
index 0000000..fa2d6b6
--- /dev/null
+++ b/net/ipv4/netfilter/nf_defrag_ipv4.c
@@ -0,0 +1,97 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <net/ip.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+
+/* Returns new sk_buff, or NULL */
+static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
+{
+	int err;
+
+	skb_orphan(skb);
+
+	local_bh_disable();
+	err = ip_defrag(skb, user);
+	local_bh_enable();
+
+	if (!err)
+		ip_send_check(ip_hdr(skb));
+
+	return err;
+}
+
+static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
+					  struct sk_buff *skb,
+					  const struct net_device *in,
+					  const struct net_device *out,
+					  int (*okfn)(struct sk_buff *))
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+#if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
+	/* Previously seen (loopback)?  Ignore.  Do this before
+	   fragment check. */
+	if (skb->nfct)
+		return NF_ACCEPT;
+#endif
+#endif
+	/* Gather fragments. */
+	if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
+		if (nf_ct_ipv4_gather_frags(skb,
+					    hooknum == NF_INET_PRE_ROUTING ?
+					    IP_DEFRAG_CONNTRACK_IN :
+					    IP_DEFRAG_CONNTRACK_OUT))
+			return NF_STOLEN;
+	}
+	return NF_ACCEPT;
+}
+
+static struct nf_hook_ops ipv4_defrag_ops[] = {
+	{
+		.hook		= ipv4_conntrack_defrag,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_PRE_ROUTING,
+		.priority	= NF_IP_PRI_CONNTRACK_DEFRAG,
+	},
+	{
+		.hook           = ipv4_conntrack_defrag,
+		.owner          = THIS_MODULE,
+		.pf             = PF_INET,
+		.hooknum        = NF_INET_LOCAL_OUT,
+		.priority       = NF_IP_PRI_CONNTRACK_DEFRAG,
+	},
+};
+
+static int __init nf_defrag_init(void)
+{
+	return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
+}
+
+static void __exit nf_defrag_fini(void)
+{
+	nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
+}
+
+void nf_defrag_ipv4_enable(void)
+{
+}
+EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
+
+module_init(nf_defrag_init);
+module_exit(nf_defrag_fini);
+
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/netfilter/nf_nat_amanda.c b/net/ipv4/netfilter/nf_nat_amanda.c
new file mode 100644
index 0000000..c31b876
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_amanda.c
@@ -0,0 +1,78 @@
+/* Amanda extension for TCP NAT alteration.
+ * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
+ * based on a copy of HW's ip_nat_irc.c as well as other modules
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_amanda.h>
+
+MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
+MODULE_DESCRIPTION("Amanda NAT helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat_amanda");
+
+static unsigned int help(struct sk_buff *skb,
+			 enum ip_conntrack_info ctinfo,
+			 unsigned int matchoff,
+			 unsigned int matchlen,
+			 struct nf_conntrack_expect *exp)
+{
+	char buffer[sizeof("65535")];
+	u_int16_t port;
+	unsigned int ret;
+
+	/* Connection comes from client. */
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->dir = IP_CT_DIR_ORIGINAL;
+
+	/* When you see the packet, we need to NAT it the same as the
+	 * this one (ie. same IP: it will be TCP and master is UDP). */
+	exp->expectfn = nf_nat_follow_master;
+
+	/* Try to get same port: if not, try to change it. */
+	for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
+		exp->tuple.dst.u.tcp.port = htons(port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (port == 0)
+		return NF_DROP;
+
+	sprintf(buffer, "%u", port);
+	ret = nf_nat_mangle_udp_packet(skb, exp->master, ctinfo,
+				       matchoff, matchlen,
+				       buffer, strlen(buffer));
+	if (ret != NF_ACCEPT)
+		nf_ct_unexpect_related(exp);
+	return ret;
+}
+
+static void __exit nf_nat_amanda_fini(void)
+{
+	rcu_assign_pointer(nf_nat_amanda_hook, NULL);
+	synchronize_rcu();
+}
+
+static int __init nf_nat_amanda_init(void)
+{
+	BUG_ON(nf_nat_amanda_hook != NULL);
+	rcu_assign_pointer(nf_nat_amanda_hook, help);
+	return 0;
+}
+
+module_init(nf_nat_amanda_init);
+module_exit(nf_nat_amanda_fini);
diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
new file mode 100644
index 0000000..a65cf69
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -0,0 +1,773 @@
+/* NAT for netfilter; shared with compatibility layer. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <net/checksum.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/tcp.h>  /* For tcp_prot in getorigdst */
+#include <linux/icmp.h>
+#include <linux/udp.h>
+#include <linux/jhash.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+
+static DEFINE_SPINLOCK(nf_nat_lock);
+
+static struct nf_conntrack_l3proto *l3proto __read_mostly;
+
+/* Calculated at init based on memory size */
+static unsigned int nf_nat_htable_size __read_mostly;
+
+#define MAX_IP_NAT_PROTO 256
+static const struct nf_nat_protocol *nf_nat_protos[MAX_IP_NAT_PROTO]
+						__read_mostly;
+
+static inline const struct nf_nat_protocol *
+__nf_nat_proto_find(u_int8_t protonum)
+{
+	return rcu_dereference(nf_nat_protos[protonum]);
+}
+
+const struct nf_nat_protocol *
+nf_nat_proto_find_get(u_int8_t protonum)
+{
+	const struct nf_nat_protocol *p;
+
+	rcu_read_lock();
+	p = __nf_nat_proto_find(protonum);
+	if (!try_module_get(p->me))
+		p = &nf_nat_unknown_protocol;
+	rcu_read_unlock();
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_find_get);
+
+void
+nf_nat_proto_put(const struct nf_nat_protocol *p)
+{
+	module_put(p->me);
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_put);
+
+/* We keep an extra hash for each conntrack, for fast searching. */
+static inline unsigned int
+hash_by_src(const struct nf_conntrack_tuple *tuple)
+{
+	unsigned int hash;
+
+	/* Original src, to ensure we map it consistently if poss. */
+	hash = jhash_3words((__force u32)tuple->src.u3.ip,
+			    (__force u32)tuple->src.u.all,
+			    tuple->dst.protonum, 0);
+	return ((u64)hash * nf_nat_htable_size) >> 32;
+}
+
+/* Is this tuple already taken? (not by us) */
+int
+nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
+		  const struct nf_conn *ignored_conntrack)
+{
+	/* Conntrack tracking doesn't keep track of outgoing tuples; only
+	   incoming ones.  NAT means they don't have a fixed mapping,
+	   so we invert the tuple and look for the incoming reply.
+
+	   We could keep a separate hash if this proves too slow. */
+	struct nf_conntrack_tuple reply;
+
+	nf_ct_invert_tuplepr(&reply, tuple);
+	return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
+}
+EXPORT_SYMBOL(nf_nat_used_tuple);
+
+/* If we source map this tuple so reply looks like reply_tuple, will
+ * that meet the constraints of range. */
+static int
+in_range(const struct nf_conntrack_tuple *tuple,
+	 const struct nf_nat_range *range)
+{
+	const struct nf_nat_protocol *proto;
+	int ret = 0;
+
+	/* If we are supposed to map IPs, then we must be in the
+	   range specified, otherwise let this drag us onto a new src IP. */
+	if (range->flags & IP_NAT_RANGE_MAP_IPS) {
+		if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) ||
+		    ntohl(tuple->src.u3.ip) > ntohl(range->max_ip))
+			return 0;
+	}
+
+	rcu_read_lock();
+	proto = __nf_nat_proto_find(tuple->dst.protonum);
+	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) ||
+	    proto->in_range(tuple, IP_NAT_MANIP_SRC,
+			    &range->min, &range->max))
+		ret = 1;
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static inline int
+same_src(const struct nf_conn *ct,
+	 const struct nf_conntrack_tuple *tuple)
+{
+	const struct nf_conntrack_tuple *t;
+
+	t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+	return (t->dst.protonum == tuple->dst.protonum &&
+		t->src.u3.ip == tuple->src.u3.ip &&
+		t->src.u.all == tuple->src.u.all);
+}
+
+/* Only called for SRC manip */
+static int
+find_appropriate_src(struct net *net,
+		     const struct nf_conntrack_tuple *tuple,
+		     struct nf_conntrack_tuple *result,
+		     const struct nf_nat_range *range)
+{
+	unsigned int h = hash_by_src(tuple);
+	const struct nf_conn_nat *nat;
+	const struct nf_conn *ct;
+	const struct hlist_node *n;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(nat, n, &net->ipv4.nat_bysource[h], bysource) {
+		ct = nat->ct;
+		if (same_src(ct, tuple)) {
+			/* Copy source part from reply tuple. */
+			nf_ct_invert_tuplepr(result,
+				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+			result->dst = tuple->dst;
+
+			if (in_range(result, range)) {
+				rcu_read_unlock();
+				return 1;
+			}
+		}
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+/* For [FUTURE] fragmentation handling, we want the least-used
+   src-ip/dst-ip/proto triple.  Fairness doesn't come into it.  Thus
+   if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
+   1-65535, we don't do pro-rata allocation based on ports; we choose
+   the ip with the lowest src-ip/dst-ip/proto usage.
+*/
+static void
+find_best_ips_proto(struct nf_conntrack_tuple *tuple,
+		    const struct nf_nat_range *range,
+		    const struct nf_conn *ct,
+		    enum nf_nat_manip_type maniptype)
+{
+	__be32 *var_ipp;
+	/* Host order */
+	u_int32_t minip, maxip, j;
+
+	/* No IP mapping?  Do nothing. */
+	if (!(range->flags & IP_NAT_RANGE_MAP_IPS))
+		return;
+
+	if (maniptype == IP_NAT_MANIP_SRC)
+		var_ipp = &tuple->src.u3.ip;
+	else
+		var_ipp = &tuple->dst.u3.ip;
+
+	/* Fast path: only one choice. */
+	if (range->min_ip == range->max_ip) {
+		*var_ipp = range->min_ip;
+		return;
+	}
+
+	/* Hashing source and destination IPs gives a fairly even
+	 * spread in practice (if there are a small number of IPs
+	 * involved, there usually aren't that many connections
+	 * anyway).  The consistency means that servers see the same
+	 * client coming from the same IP (some Internet Banking sites
+	 * like this), even across reboots. */
+	minip = ntohl(range->min_ip);
+	maxip = ntohl(range->max_ip);
+	j = jhash_2words((__force u32)tuple->src.u3.ip,
+			 (__force u32)tuple->dst.u3.ip, 0);
+	j = ((u64)j * (maxip - minip + 1)) >> 32;
+	*var_ipp = htonl(minip + j);
+}
+
+/* Manipulate the tuple into the range given.  For NF_INET_POST_ROUTING,
+ * we change the source to map into the range.  For NF_INET_PRE_ROUTING
+ * and NF_INET_LOCAL_OUT, we change the destination to map into the
+ * range.  It might not be possible to get a unique tuple, but we try.
+ * At worst (or if we race), we will end up with a final duplicate in
+ * __ip_conntrack_confirm and drop the packet. */
+static void
+get_unique_tuple(struct nf_conntrack_tuple *tuple,
+		 const struct nf_conntrack_tuple *orig_tuple,
+		 const struct nf_nat_range *range,
+		 struct nf_conn *ct,
+		 enum nf_nat_manip_type maniptype)
+{
+	struct net *net = nf_ct_net(ct);
+	const struct nf_nat_protocol *proto;
+
+	/* 1) If this srcip/proto/src-proto-part is currently mapped,
+	   and that same mapping gives a unique tuple within the given
+	   range, use that.
+
+	   This is only required for source (ie. NAT/masq) mappings.
+	   So far, we don't do local source mappings, so multiple
+	   manips not an issue.  */
+	if (maniptype == IP_NAT_MANIP_SRC &&
+	    !(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) {
+		if (find_appropriate_src(net, orig_tuple, tuple, range)) {
+			pr_debug("get_unique_tuple: Found current src map\n");
+			if (!nf_nat_used_tuple(tuple, ct))
+				return;
+		}
+	}
+
+	/* 2) Select the least-used IP/proto combination in the given
+	   range. */
+	*tuple = *orig_tuple;
+	find_best_ips_proto(tuple, range, ct, maniptype);
+
+	/* 3) The per-protocol part of the manip is made to map into
+	   the range to make a unique tuple. */
+
+	rcu_read_lock();
+	proto = __nf_nat_proto_find(orig_tuple->dst.protonum);
+
+	/* Change protocol info to have some randomization */
+	if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) {
+		proto->unique_tuple(tuple, range, maniptype, ct);
+		goto out;
+	}
+
+	/* Only bother mapping if it's not already in range and unique */
+	if ((!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) ||
+	     proto->in_range(tuple, maniptype, &range->min, &range->max)) &&
+	    !nf_nat_used_tuple(tuple, ct))
+		goto out;
+
+	/* Last change: get protocol to try to obtain unique tuple. */
+	proto->unique_tuple(tuple, range, maniptype, ct);
+out:
+	rcu_read_unlock();
+}
+
+unsigned int
+nf_nat_setup_info(struct nf_conn *ct,
+		  const struct nf_nat_range *range,
+		  enum nf_nat_manip_type maniptype)
+{
+	struct net *net = nf_ct_net(ct);
+	struct nf_conntrack_tuple curr_tuple, new_tuple;
+	struct nf_conn_nat *nat;
+	int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK);
+
+	/* nat helper or nfctnetlink also setup binding */
+	nat = nfct_nat(ct);
+	if (!nat) {
+		nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+		if (nat == NULL) {
+			pr_debug("failed to add NAT extension\n");
+			return NF_ACCEPT;
+		}
+	}
+
+	NF_CT_ASSERT(maniptype == IP_NAT_MANIP_SRC ||
+		     maniptype == IP_NAT_MANIP_DST);
+	BUG_ON(nf_nat_initialized(ct, maniptype));
+
+	/* What we've got will look like inverse of reply. Normally
+	   this is what is in the conntrack, except for prior
+	   manipulations (future optimization: if num_manips == 0,
+	   orig_tp =
+	   conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */
+	nf_ct_invert_tuplepr(&curr_tuple,
+			     &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+	get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
+
+	if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
+		struct nf_conntrack_tuple reply;
+
+		/* Alter conntrack table so will recognize replies. */
+		nf_ct_invert_tuplepr(&reply, &new_tuple);
+		nf_conntrack_alter_reply(ct, &reply);
+
+		/* Non-atomic: we own this at the moment. */
+		if (maniptype == IP_NAT_MANIP_SRC)
+			ct->status |= IPS_SRC_NAT;
+		else
+			ct->status |= IPS_DST_NAT;
+	}
+
+	/* Place in source hash if this is the first time. */
+	if (have_to_hash) {
+		unsigned int srchash;
+
+		srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+		spin_lock_bh(&nf_nat_lock);
+		/* nf_conntrack_alter_reply might re-allocate exntension aera */
+		nat = nfct_nat(ct);
+		nat->ct = ct;
+		hlist_add_head_rcu(&nat->bysource,
+				   &net->ipv4.nat_bysource[srchash]);
+		spin_unlock_bh(&nf_nat_lock);
+	}
+
+	/* It's done. */
+	if (maniptype == IP_NAT_MANIP_DST)
+		set_bit(IPS_DST_NAT_DONE_BIT, &ct->status);
+	else
+		set_bit(IPS_SRC_NAT_DONE_BIT, &ct->status);
+
+	return NF_ACCEPT;
+}
+EXPORT_SYMBOL(nf_nat_setup_info);
+
+/* Returns true if succeeded. */
+static bool
+manip_pkt(u_int16_t proto,
+	  struct sk_buff *skb,
+	  unsigned int iphdroff,
+	  const struct nf_conntrack_tuple *target,
+	  enum nf_nat_manip_type maniptype)
+{
+	struct iphdr *iph;
+	const struct nf_nat_protocol *p;
+
+	if (!skb_make_writable(skb, iphdroff + sizeof(*iph)))
+		return false;
+
+	iph = (void *)skb->data + iphdroff;
+
+	/* Manipulate protcol part. */
+
+	/* rcu_read_lock()ed by nf_hook_slow */
+	p = __nf_nat_proto_find(proto);
+	if (!p->manip_pkt(skb, iphdroff, target, maniptype))
+		return false;
+
+	iph = (void *)skb->data + iphdroff;
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		csum_replace4(&iph->check, iph->saddr, target->src.u3.ip);
+		iph->saddr = target->src.u3.ip;
+	} else {
+		csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip);
+		iph->daddr = target->dst.u3.ip;
+	}
+	return true;
+}
+
+/* Do packet manipulations according to nf_nat_setup_info. */
+unsigned int nf_nat_packet(struct nf_conn *ct,
+			   enum ip_conntrack_info ctinfo,
+			   unsigned int hooknum,
+			   struct sk_buff *skb)
+{
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	unsigned long statusbit;
+	enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
+
+	if (mtype == IP_NAT_MANIP_SRC)
+		statusbit = IPS_SRC_NAT;
+	else
+		statusbit = IPS_DST_NAT;
+
+	/* Invert if this is reply dir. */
+	if (dir == IP_CT_DIR_REPLY)
+		statusbit ^= IPS_NAT_MASK;
+
+	/* Non-atomic: these bits don't change. */
+	if (ct->status & statusbit) {
+		struct nf_conntrack_tuple target;
+
+		/* We are aiming to look like inverse of other direction. */
+		nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
+
+		if (!manip_pkt(target.dst.protonum, skb, 0, &target, mtype))
+			return NF_DROP;
+	}
+	return NF_ACCEPT;
+}
+EXPORT_SYMBOL_GPL(nf_nat_packet);
+
+/* Dir is direction ICMP is coming from (opposite to packet it contains) */
+int nf_nat_icmp_reply_translation(struct nf_conn *ct,
+				  enum ip_conntrack_info ctinfo,
+				  unsigned int hooknum,
+				  struct sk_buff *skb)
+{
+	struct {
+		struct icmphdr icmp;
+		struct iphdr ip;
+	} *inside;
+	const struct nf_conntrack_l4proto *l4proto;
+	struct nf_conntrack_tuple inner, target;
+	int hdrlen = ip_hdrlen(skb);
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	unsigned long statusbit;
+	enum nf_nat_manip_type manip = HOOK2MANIP(hooknum);
+
+	if (!skb_make_writable(skb, hdrlen + sizeof(*inside)))
+		return 0;
+
+	inside = (void *)skb->data + ip_hdrlen(skb);
+
+	/* We're actually going to mangle it beyond trivial checksum
+	   adjustment, so make sure the current checksum is correct. */
+	if (nf_ip_checksum(skb, hooknum, hdrlen, 0))
+		return 0;
+
+	/* Must be RELATED */
+	NF_CT_ASSERT(skb->nfctinfo == IP_CT_RELATED ||
+		     skb->nfctinfo == IP_CT_RELATED+IP_CT_IS_REPLY);
+
+	/* Redirects on non-null nats must be dropped, else they'll
+	   start talking to each other without our translation, and be
+	   confused... --RR */
+	if (inside->icmp.type == ICMP_REDIRECT) {
+		/* If NAT isn't finished, assume it and drop. */
+		if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK)
+			return 0;
+
+		if (ct->status & IPS_NAT_MASK)
+			return 0;
+	}
+
+	pr_debug("icmp_reply_translation: translating error %p manip %u "
+		 "dir %s\n", skb, manip,
+		 dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY");
+
+	/* rcu_read_lock()ed by nf_hook_slow */
+	l4proto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol);
+
+	if (!nf_ct_get_tuple(skb,
+			     ip_hdrlen(skb) + sizeof(struct icmphdr),
+			     (ip_hdrlen(skb) +
+			      sizeof(struct icmphdr) + inside->ip.ihl * 4),
+			     (u_int16_t)AF_INET,
+			     inside->ip.protocol,
+			     &inner, l3proto, l4proto))
+		return 0;
+
+	/* Change inner back to look like incoming packet.  We do the
+	   opposite manip on this hook to normal, because it might not
+	   pass all hooks (locally-generated ICMP).  Consider incoming
+	   packet: PREROUTING (DST manip), routing produces ICMP, goes
+	   through POSTROUTING (which must correct the DST manip). */
+	if (!manip_pkt(inside->ip.protocol, skb,
+		       ip_hdrlen(skb) + sizeof(inside->icmp),
+		       &ct->tuplehash[!dir].tuple,
+		       !manip))
+		return 0;
+
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		/* Reloading "inside" here since manip_pkt inner. */
+		inside = (void *)skb->data + ip_hdrlen(skb);
+		inside->icmp.checksum = 0;
+		inside->icmp.checksum =
+			csum_fold(skb_checksum(skb, hdrlen,
+					       skb->len - hdrlen, 0));
+	}
+
+	/* Change outer to look the reply to an incoming packet
+	 * (proto 0 means don't invert per-proto part). */
+	if (manip == IP_NAT_MANIP_SRC)
+		statusbit = IPS_SRC_NAT;
+	else
+		statusbit = IPS_DST_NAT;
+
+	/* Invert if this is reply dir. */
+	if (dir == IP_CT_DIR_REPLY)
+		statusbit ^= IPS_NAT_MASK;
+
+	if (ct->status & statusbit) {
+		nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
+		if (!manip_pkt(0, skb, 0, &target, manip))
+			return 0;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation);
+
+/* Protocol registration. */
+int nf_nat_protocol_register(const struct nf_nat_protocol *proto)
+{
+	int ret = 0;
+
+	spin_lock_bh(&nf_nat_lock);
+	if (nf_nat_protos[proto->protonum] != &nf_nat_unknown_protocol) {
+		ret = -EBUSY;
+		goto out;
+	}
+	rcu_assign_pointer(nf_nat_protos[proto->protonum], proto);
+ out:
+	spin_unlock_bh(&nf_nat_lock);
+	return ret;
+}
+EXPORT_SYMBOL(nf_nat_protocol_register);
+
+/* Noone stores the protocol anywhere; simply delete it. */
+void nf_nat_protocol_unregister(const struct nf_nat_protocol *proto)
+{
+	spin_lock_bh(&nf_nat_lock);
+	rcu_assign_pointer(nf_nat_protos[proto->protonum],
+			   &nf_nat_unknown_protocol);
+	spin_unlock_bh(&nf_nat_lock);
+	synchronize_rcu();
+}
+EXPORT_SYMBOL(nf_nat_protocol_unregister);
+
+/* Noone using conntrack by the time this called. */
+static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
+{
+	struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT);
+
+	if (nat == NULL || nat->ct == NULL)
+		return;
+
+	NF_CT_ASSERT(nat->ct->status & IPS_NAT_DONE_MASK);
+
+	spin_lock_bh(&nf_nat_lock);
+	hlist_del_rcu(&nat->bysource);
+	spin_unlock_bh(&nf_nat_lock);
+}
+
+static void nf_nat_move_storage(void *new, void *old)
+{
+	struct nf_conn_nat *new_nat = new;
+	struct nf_conn_nat *old_nat = old;
+	struct nf_conn *ct = old_nat->ct;
+
+	if (!ct || !(ct->status & IPS_NAT_DONE_MASK))
+		return;
+
+	spin_lock_bh(&nf_nat_lock);
+	new_nat->ct = ct;
+	hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource);
+	spin_unlock_bh(&nf_nat_lock);
+}
+
+static struct nf_ct_ext_type nat_extend __read_mostly = {
+	.len		= sizeof(struct nf_conn_nat),
+	.align		= __alignof__(struct nf_conn_nat),
+	.destroy	= nf_nat_cleanup_conntrack,
+	.move		= nf_nat_move_storage,
+	.id		= NF_CT_EXT_NAT,
+	.flags		= NF_CT_EXT_F_PREALLOC,
+};
+
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
+	[CTA_PROTONAT_PORT_MIN]	= { .type = NLA_U16 },
+	[CTA_PROTONAT_PORT_MAX]	= { .type = NLA_U16 },
+};
+
+static int nfnetlink_parse_nat_proto(struct nlattr *attr,
+				     const struct nf_conn *ct,
+				     struct nf_nat_range *range)
+{
+	struct nlattr *tb[CTA_PROTONAT_MAX+1];
+	const struct nf_nat_protocol *npt;
+	int err;
+
+	err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy);
+	if (err < 0)
+		return err;
+
+	npt = nf_nat_proto_find_get(nf_ct_protonum(ct));
+	if (npt->nlattr_to_range)
+		err = npt->nlattr_to_range(tb, range);
+	nf_nat_proto_put(npt);
+	return err;
+}
+
+static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
+	[CTA_NAT_MINIP]		= { .type = NLA_U32 },
+	[CTA_NAT_MAXIP]		= { .type = NLA_U32 },
+};
+
+static int
+nfnetlink_parse_nat(struct nlattr *nat,
+		    const struct nf_conn *ct, struct nf_nat_range *range)
+{
+	struct nlattr *tb[CTA_NAT_MAX+1];
+	int err;
+
+	memset(range, 0, sizeof(*range));
+
+	err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy);
+	if (err < 0)
+		return err;
+
+	if (tb[CTA_NAT_MINIP])
+		range->min_ip = nla_get_be32(tb[CTA_NAT_MINIP]);
+
+	if (!tb[CTA_NAT_MAXIP])
+		range->max_ip = range->min_ip;
+	else
+		range->max_ip = nla_get_be32(tb[CTA_NAT_MAXIP]);
+
+	if (range->min_ip)
+		range->flags |= IP_NAT_RANGE_MAP_IPS;
+
+	if (!tb[CTA_NAT_PROTO])
+		return 0;
+
+	err = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int
+nfnetlink_parse_nat_setup(struct nf_conn *ct,
+			  enum nf_nat_manip_type manip,
+			  struct nlattr *attr)
+{
+	struct nf_nat_range range;
+
+	if (nfnetlink_parse_nat(attr, ct, &range) < 0)
+		return -EINVAL;
+	if (nf_nat_initialized(ct, manip))
+		return -EEXIST;
+
+	return nf_nat_setup_info(ct, &range, manip);
+}
+#else
+static int
+nfnetlink_parse_nat_setup(struct nf_conn *ct,
+			  enum nf_nat_manip_type manip,
+			  struct nlattr *attr)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+static int __net_init nf_nat_net_init(struct net *net)
+{
+	net->ipv4.nat_bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size,
+						      &net->ipv4.nat_vmalloced);
+	if (!net->ipv4.nat_bysource)
+		return -ENOMEM;
+	return 0;
+}
+
+/* Clear NAT section of all conntracks, in case we're loaded again. */
+static int clean_nat(struct nf_conn *i, void *data)
+{
+	struct nf_conn_nat *nat = nfct_nat(i);
+
+	if (!nat)
+		return 0;
+	memset(nat, 0, sizeof(*nat));
+	i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST);
+	return 0;
+}
+
+static void __net_exit nf_nat_net_exit(struct net *net)
+{
+	nf_ct_iterate_cleanup(net, &clean_nat, NULL);
+	synchronize_rcu();
+	nf_ct_free_hashtable(net->ipv4.nat_bysource, net->ipv4.nat_vmalloced,
+			     nf_nat_htable_size);
+}
+
+static struct pernet_operations nf_nat_net_ops = {
+	.init = nf_nat_net_init,
+	.exit = nf_nat_net_exit,
+};
+
+static int __init nf_nat_init(void)
+{
+	size_t i;
+	int ret;
+
+	need_ipv4_conntrack();
+
+	ret = nf_ct_extend_register(&nat_extend);
+	if (ret < 0) {
+		printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
+		return ret;
+	}
+
+	/* Leave them the same for the moment. */
+	nf_nat_htable_size = nf_conntrack_htable_size;
+
+	ret = register_pernet_subsys(&nf_nat_net_ops);
+	if (ret < 0)
+		goto cleanup_extend;
+
+	/* Sew in builtin protocols. */
+	spin_lock_bh(&nf_nat_lock);
+	for (i = 0; i < MAX_IP_NAT_PROTO; i++)
+		rcu_assign_pointer(nf_nat_protos[i], &nf_nat_unknown_protocol);
+	rcu_assign_pointer(nf_nat_protos[IPPROTO_TCP], &nf_nat_protocol_tcp);
+	rcu_assign_pointer(nf_nat_protos[IPPROTO_UDP], &nf_nat_protocol_udp);
+	rcu_assign_pointer(nf_nat_protos[IPPROTO_ICMP], &nf_nat_protocol_icmp);
+	spin_unlock_bh(&nf_nat_lock);
+
+	/* Initialize fake conntrack so that NAT will skip it */
+	nf_conntrack_untracked.status |= IPS_NAT_DONE_MASK;
+
+	l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET);
+
+	BUG_ON(nf_nat_seq_adjust_hook != NULL);
+	rcu_assign_pointer(nf_nat_seq_adjust_hook, nf_nat_seq_adjust);
+	BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
+	rcu_assign_pointer(nfnetlink_parse_nat_setup_hook,
+			   nfnetlink_parse_nat_setup);
+	return 0;
+
+ cleanup_extend:
+	nf_ct_extend_unregister(&nat_extend);
+	return ret;
+}
+
+static void __exit nf_nat_cleanup(void)
+{
+	unregister_pernet_subsys(&nf_nat_net_ops);
+	nf_ct_l3proto_put(l3proto);
+	nf_ct_extend_unregister(&nat_extend);
+	rcu_assign_pointer(nf_nat_seq_adjust_hook, NULL);
+	rcu_assign_pointer(nfnetlink_parse_nat_setup_hook, NULL);
+	synchronize_net();
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("nf-nat-ipv4");
+
+module_init(nf_nat_init);
+module_exit(nf_nat_cleanup);
diff --git a/net/ipv4/netfilter/nf_nat_ftp.c b/net/ipv4/netfilter/nf_nat_ftp.c
new file mode 100644
index 0000000..a1d5d58
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_ftp.c
@@ -0,0 +1,165 @@
+/* FTP extension for TCP NAT alteration. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_ftp.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
+MODULE_DESCRIPTION("ftp NAT helper");
+MODULE_ALIAS("ip_nat_ftp");
+
+/* FIXME: Time out? --RR */
+
+static int
+mangle_rfc959_packet(struct sk_buff *skb,
+		     __be32 newip,
+		     u_int16_t port,
+		     unsigned int matchoff,
+		     unsigned int matchlen,
+		     struct nf_conn *ct,
+		     enum ip_conntrack_info ctinfo)
+{
+	char buffer[sizeof("nnn,nnn,nnn,nnn,nnn,nnn")];
+
+	sprintf(buffer, "%u,%u,%u,%u,%u,%u",
+		NIPQUAD(newip), port>>8, port&0xFF);
+
+	pr_debug("calling nf_nat_mangle_tcp_packet\n");
+
+	return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
+					matchlen, buffer, strlen(buffer));
+}
+
+/* |1|132.235.1.2|6275| */
+static int
+mangle_eprt_packet(struct sk_buff *skb,
+		   __be32 newip,
+		   u_int16_t port,
+		   unsigned int matchoff,
+		   unsigned int matchlen,
+		   struct nf_conn *ct,
+		   enum ip_conntrack_info ctinfo)
+{
+	char buffer[sizeof("|1|255.255.255.255|65535|")];
+
+	sprintf(buffer, "|1|%u.%u.%u.%u|%u|", NIPQUAD(newip), port);
+
+	pr_debug("calling nf_nat_mangle_tcp_packet\n");
+
+	return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
+					matchlen, buffer, strlen(buffer));
+}
+
+/* |1|132.235.1.2|6275| */
+static int
+mangle_epsv_packet(struct sk_buff *skb,
+		   __be32 newip,
+		   u_int16_t port,
+		   unsigned int matchoff,
+		   unsigned int matchlen,
+		   struct nf_conn *ct,
+		   enum ip_conntrack_info ctinfo)
+{
+	char buffer[sizeof("|||65535|")];
+
+	sprintf(buffer, "|||%u|", port);
+
+	pr_debug("calling nf_nat_mangle_tcp_packet\n");
+
+	return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff,
+					matchlen, buffer, strlen(buffer));
+}
+
+static int (*mangle[])(struct sk_buff *, __be32, u_int16_t,
+		       unsigned int, unsigned int, struct nf_conn *,
+		       enum ip_conntrack_info)
+= {
+	[NF_CT_FTP_PORT] = mangle_rfc959_packet,
+	[NF_CT_FTP_PASV] = mangle_rfc959_packet,
+	[NF_CT_FTP_EPRT] = mangle_eprt_packet,
+	[NF_CT_FTP_EPSV] = mangle_epsv_packet
+};
+
+/* So, this packet has hit the connection tracking matching code.
+   Mangle it, and change the expectation to match the new version. */
+static unsigned int nf_nat_ftp(struct sk_buff *skb,
+			       enum ip_conntrack_info ctinfo,
+			       enum nf_ct_ftp_type type,
+			       unsigned int matchoff,
+			       unsigned int matchlen,
+			       struct nf_conntrack_expect *exp)
+{
+	__be32 newip;
+	u_int16_t port;
+	int dir = CTINFO2DIR(ctinfo);
+	struct nf_conn *ct = exp->master;
+
+	pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen);
+
+	/* Connection will come from wherever this packet goes, hence !dir */
+	newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->dir = !dir;
+
+	/* When you see the packet, we need to NAT it the same as the
+	 * this one. */
+	exp->expectfn = nf_nat_follow_master;
+
+	/* Try to get same port: if not, try to change it. */
+	for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
+		exp->tuple.dst.u.tcp.port = htons(port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (port == 0)
+		return NF_DROP;
+
+	if (!mangle[type](skb, newip, port, matchoff, matchlen, ct, ctinfo)) {
+		nf_ct_unexpect_related(exp);
+		return NF_DROP;
+	}
+	return NF_ACCEPT;
+}
+
+static void __exit nf_nat_ftp_fini(void)
+{
+	rcu_assign_pointer(nf_nat_ftp_hook, NULL);
+	synchronize_rcu();
+}
+
+static int __init nf_nat_ftp_init(void)
+{
+	BUG_ON(nf_nat_ftp_hook != NULL);
+	rcu_assign_pointer(nf_nat_ftp_hook, nf_nat_ftp);
+	return 0;
+}
+
+/* Prior to 2.6.11, we had a ports param.  No longer, but don't break users. */
+static int warn_set(const char *val, struct kernel_param *kp)
+{
+	printk(KERN_INFO KBUILD_MODNAME
+	       ": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n");
+	return 0;
+}
+module_param_call(ports, warn_set, NULL, NULL, 0);
+
+module_init(nf_nat_ftp_init);
+module_exit(nf_nat_ftp_fini);
diff --git a/net/ipv4/netfilter/nf_nat_h323.c b/net/ipv4/netfilter/nf_nat_h323.c
new file mode 100644
index 0000000..ee47bf2
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_h323.c
@@ -0,0 +1,584 @@
+/*
+ * H.323 extension for NAT alteration.
+ *
+ * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
+ *
+ * This source code is licensed under General Public License version 2.
+ *
+ * Based on the 'brute force' H.323 NAT module by
+ * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/tcp.h>
+#include <net/tcp.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_h323.h>
+
+/****************************************************************************/
+static int set_addr(struct sk_buff *skb,
+		    unsigned char **data, int dataoff,
+		    unsigned int addroff, __be32 ip, __be16 port)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	struct {
+		__be32 ip;
+		__be16 port;
+	} __attribute__ ((__packed__)) buf;
+	const struct tcphdr *th;
+	struct tcphdr _tcph;
+
+	buf.ip = ip;
+	buf.port = port;
+	addroff += dataoff;
+
+	if (ip_hdr(skb)->protocol == IPPROTO_TCP) {
+		if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+					      addroff, sizeof(buf),
+					      (char *) &buf, sizeof(buf))) {
+			if (net_ratelimit())
+				printk("nf_nat_h323: nf_nat_mangle_tcp_packet"
+				       " error\n");
+			return -1;
+		}
+
+		/* Relocate data pointer */
+		th = skb_header_pointer(skb, ip_hdrlen(skb),
+					sizeof(_tcph), &_tcph);
+		if (th == NULL)
+			return -1;
+		*data = skb->data + ip_hdrlen(skb) + th->doff * 4 + dataoff;
+	} else {
+		if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo,
+					      addroff, sizeof(buf),
+					      (char *) &buf, sizeof(buf))) {
+			if (net_ratelimit())
+				printk("nf_nat_h323: nf_nat_mangle_udp_packet"
+				       " error\n");
+			return -1;
+		}
+		/* nf_nat_mangle_udp_packet uses skb_make_writable() to copy
+		 * or pull everything in a linear buffer, so we can safely
+		 * use the skb pointers now */
+		*data = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+static int set_h225_addr(struct sk_buff *skb,
+			 unsigned char **data, int dataoff,
+			 TransportAddress *taddr,
+			 union nf_inet_addr *addr, __be16 port)
+{
+	return set_addr(skb, data, dataoff, taddr->ipAddress.ip,
+			addr->ip, port);
+}
+
+/****************************************************************************/
+static int set_h245_addr(struct sk_buff *skb,
+			 unsigned char **data, int dataoff,
+			 H245_TransportAddress *taddr,
+			 union nf_inet_addr *addr, __be16 port)
+{
+	return set_addr(skb, data, dataoff,
+			taddr->unicastAddress.iPAddress.network,
+			addr->ip, port);
+}
+
+/****************************************************************************/
+static int set_sig_addr(struct sk_buff *skb, struct nf_conn *ct,
+			enum ip_conntrack_info ctinfo,
+			unsigned char **data,
+			TransportAddress *taddr, int count)
+{
+	const struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+	int dir = CTINFO2DIR(ctinfo);
+	int i;
+	__be16 port;
+	union nf_inet_addr addr;
+
+	for (i = 0; i < count; i++) {
+		if (get_h225_addr(ct, *data, &taddr[i], &addr, &port)) {
+			if (addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
+			    port == info->sig_port[dir]) {
+				/* GW->GK */
+
+				/* Fix for Gnomemeeting */
+				if (i > 0 &&
+				    get_h225_addr(ct, *data, &taddr[0],
+						  &addr, &port) &&
+				    (ntohl(addr.ip) & 0xff000000) == 0x7f000000)
+					i = 0;
+
+				pr_debug("nf_nat_ras: set signal address "
+					 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+					 NIPQUAD(addr.ip), port,
+					 NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
+					 info->sig_port[!dir]);
+				return set_h225_addr(skb, data, 0, &taddr[i],
+						     &ct->tuplehash[!dir].
+						     tuple.dst.u3,
+						     info->sig_port[!dir]);
+			} else if (addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
+				   port == info->sig_port[dir]) {
+				/* GK->GW */
+				pr_debug("nf_nat_ras: set signal address "
+					 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+					 NIPQUAD(addr.ip), port,
+					 NIPQUAD(ct->tuplehash[!dir].tuple.src.u3.ip),
+					 info->sig_port[!dir]);
+				return set_h225_addr(skb, data, 0, &taddr[i],
+						     &ct->tuplehash[!dir].
+						     tuple.src.u3,
+						     info->sig_port[!dir]);
+			}
+		}
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+static int set_ras_addr(struct sk_buff *skb, struct nf_conn *ct,
+			enum ip_conntrack_info ctinfo,
+			unsigned char **data,
+			TransportAddress *taddr, int count)
+{
+	int dir = CTINFO2DIR(ctinfo);
+	int i;
+	__be16 port;
+	union nf_inet_addr addr;
+
+	for (i = 0; i < count; i++) {
+		if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
+		    addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
+		    port == ct->tuplehash[dir].tuple.src.u.udp.port) {
+			pr_debug("nf_nat_ras: set rasAddress "
+				 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+				 NIPQUAD(addr.ip), ntohs(port),
+				 NIPQUAD(ct->tuplehash[!dir].tuple.dst.u3.ip),
+				 ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port));
+			return set_h225_addr(skb, data, 0, &taddr[i],
+					     &ct->tuplehash[!dir].tuple.dst.u3,
+					     ct->tuplehash[!dir].tuple.
+								dst.u.udp.port);
+		}
+	}
+
+	return 0;
+}
+
+/****************************************************************************/
+static int nat_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
+			enum ip_conntrack_info ctinfo,
+			unsigned char **data, int dataoff,
+			H245_TransportAddress *taddr,
+			__be16 port, __be16 rtp_port,
+			struct nf_conntrack_expect *rtp_exp,
+			struct nf_conntrack_expect *rtcp_exp)
+{
+	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+	int dir = CTINFO2DIR(ctinfo);
+	int i;
+	u_int16_t nated_port;
+
+	/* Set expectations for NAT */
+	rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port;
+	rtp_exp->expectfn = nf_nat_follow_master;
+	rtp_exp->dir = !dir;
+	rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port;
+	rtcp_exp->expectfn = nf_nat_follow_master;
+	rtcp_exp->dir = !dir;
+
+	/* Lookup existing expects */
+	for (i = 0; i < H323_RTP_CHANNEL_MAX; i++) {
+		if (info->rtp_port[i][dir] == rtp_port) {
+			/* Expected */
+
+			/* Use allocated ports first. This will refresh
+			 * the expects */
+			rtp_exp->tuple.dst.u.udp.port = info->rtp_port[i][dir];
+			rtcp_exp->tuple.dst.u.udp.port =
+			    htons(ntohs(info->rtp_port[i][dir]) + 1);
+			break;
+		} else if (info->rtp_port[i][dir] == 0) {
+			/* Not expected */
+			break;
+		}
+	}
+
+	/* Run out of expectations */
+	if (i >= H323_RTP_CHANNEL_MAX) {
+		if (net_ratelimit())
+			printk("nf_nat_h323: out of expectations\n");
+		return 0;
+	}
+
+	/* Try to get a pair of ports. */
+	for (nated_port = ntohs(rtp_exp->tuple.dst.u.udp.port);
+	     nated_port != 0; nated_port += 2) {
+		rtp_exp->tuple.dst.u.udp.port = htons(nated_port);
+		if (nf_ct_expect_related(rtp_exp) == 0) {
+			rtcp_exp->tuple.dst.u.udp.port =
+			    htons(nated_port + 1);
+			if (nf_ct_expect_related(rtcp_exp) == 0)
+				break;
+			nf_ct_unexpect_related(rtp_exp);
+		}
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		if (net_ratelimit())
+			printk("nf_nat_h323: out of RTP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h245_addr(skb, data, dataoff, taddr,
+			  &ct->tuplehash[!dir].tuple.dst.u3,
+			  htons((port & htons(1)) ? nated_port + 1 :
+						    nated_port)) == 0) {
+		/* Save ports */
+		info->rtp_port[i][dir] = rtp_port;
+		info->rtp_port[i][!dir] = htons(nated_port);
+	} else {
+		nf_ct_unexpect_related(rtp_exp);
+		nf_ct_unexpect_related(rtcp_exp);
+		return -1;
+	}
+
+	/* Success */
+	pr_debug("nf_nat_h323: expect RTP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+		 NIPQUAD(rtp_exp->tuple.src.u3.ip),
+		 ntohs(rtp_exp->tuple.src.u.udp.port),
+		 NIPQUAD(rtp_exp->tuple.dst.u3.ip),
+		 ntohs(rtp_exp->tuple.dst.u.udp.port));
+	pr_debug("nf_nat_h323: expect RTCP %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+		 NIPQUAD(rtcp_exp->tuple.src.u3.ip),
+		 ntohs(rtcp_exp->tuple.src.u.udp.port),
+		 NIPQUAD(rtcp_exp->tuple.dst.u3.ip),
+		 ntohs(rtcp_exp->tuple.dst.u.udp.port));
+
+	return 0;
+}
+
+/****************************************************************************/
+static int nat_t120(struct sk_buff *skb, struct nf_conn *ct,
+		    enum ip_conntrack_info ctinfo,
+		    unsigned char **data, int dataoff,
+		    H245_TransportAddress *taddr, __be16 port,
+		    struct nf_conntrack_expect *exp)
+{
+	int dir = CTINFO2DIR(ctinfo);
+	u_int16_t nated_port = ntohs(port);
+
+	/* Set expectations for NAT */
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->expectfn = nf_nat_follow_master;
+	exp->dir = !dir;
+
+	/* Try to get same port: if not, try to change it. */
+	for (; nated_port != 0; nated_port++) {
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		if (net_ratelimit())
+			printk("nf_nat_h323: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h245_addr(skb, data, dataoff, taddr,
+			  &ct->tuplehash[!dir].tuple.dst.u3,
+			  htons(nated_port)) < 0) {
+		nf_ct_unexpect_related(exp);
+		return -1;
+	}
+
+	pr_debug("nf_nat_h323: expect T.120 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+		 NIPQUAD(exp->tuple.src.u3.ip),
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 NIPQUAD(exp->tuple.dst.u3.ip),
+		 ntohs(exp->tuple.dst.u.tcp.port));
+
+	return 0;
+}
+
+/****************************************************************************/
+static int nat_h245(struct sk_buff *skb, struct nf_conn *ct,
+		    enum ip_conntrack_info ctinfo,
+		    unsigned char **data, int dataoff,
+		    TransportAddress *taddr, __be16 port,
+		    struct nf_conntrack_expect *exp)
+{
+	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+	int dir = CTINFO2DIR(ctinfo);
+	u_int16_t nated_port = ntohs(port);
+
+	/* Set expectations for NAT */
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->expectfn = nf_nat_follow_master;
+	exp->dir = !dir;
+
+	/* Check existing expects */
+	if (info->sig_port[dir] == port)
+		nated_port = ntohs(info->sig_port[!dir]);
+
+	/* Try to get same port: if not, try to change it. */
+	for (; nated_port != 0; nated_port++) {
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		if (net_ratelimit())
+			printk("nf_nat_q931: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h225_addr(skb, data, dataoff, taddr,
+			  &ct->tuplehash[!dir].tuple.dst.u3,
+			  htons(nated_port)) == 0) {
+		/* Save ports */
+		info->sig_port[dir] = port;
+		info->sig_port[!dir] = htons(nated_port);
+	} else {
+		nf_ct_unexpect_related(exp);
+		return -1;
+	}
+
+	pr_debug("nf_nat_q931: expect H.245 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+		 NIPQUAD(exp->tuple.src.u3.ip),
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 NIPQUAD(exp->tuple.dst.u3.ip),
+		 ntohs(exp->tuple.dst.u.tcp.port));
+
+	return 0;
+}
+
+/****************************************************************************
+ * This conntrack expect function replaces nf_conntrack_q931_expect()
+ * which was set by nf_conntrack_h323.c.
+ ****************************************************************************/
+static void ip_nat_q931_expect(struct nf_conn *new,
+			       struct nf_conntrack_expect *this)
+{
+	struct nf_nat_range range;
+
+	if (this->tuple.src.u3.ip != 0) {	/* Only accept calls from GK */
+		nf_nat_follow_master(new, this);
+		return;
+	}
+
+	/* This must be a fresh one. */
+	BUG_ON(new->status & IPS_NAT_DONE_MASK);
+
+	/* Change src to where master sends to */
+	range.flags = IP_NAT_RANGE_MAP_IPS;
+	range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip;
+	nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
+	range.min = range.max = this->saved_proto;
+	range.min_ip = range.max_ip =
+	    new->master->tuplehash[!this->dir].tuple.src.u3.ip;
+	nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST);
+}
+
+/****************************************************************************/
+static int nat_q931(struct sk_buff *skb, struct nf_conn *ct,
+		    enum ip_conntrack_info ctinfo,
+		    unsigned char **data, TransportAddress *taddr, int idx,
+		    __be16 port, struct nf_conntrack_expect *exp)
+{
+	struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+	int dir = CTINFO2DIR(ctinfo);
+	u_int16_t nated_port = ntohs(port);
+	union nf_inet_addr addr;
+
+	/* Set expectations for NAT */
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->expectfn = ip_nat_q931_expect;
+	exp->dir = !dir;
+
+	/* Check existing expects */
+	if (info->sig_port[dir] == port)
+		nated_port = ntohs(info->sig_port[!dir]);
+
+	/* Try to get same port: if not, try to change it. */
+	for (; nated_port != 0; nated_port++) {
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		if (net_ratelimit())
+			printk("nf_nat_ras: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (set_h225_addr(skb, data, 0, &taddr[idx],
+			  &ct->tuplehash[!dir].tuple.dst.u3,
+			  htons(nated_port)) == 0) {
+		/* Save ports */
+		info->sig_port[dir] = port;
+		info->sig_port[!dir] = htons(nated_port);
+
+		/* Fix for Gnomemeeting */
+		if (idx > 0 &&
+		    get_h225_addr(ct, *data, &taddr[0], &addr, &port) &&
+		    (ntohl(addr.ip) & 0xff000000) == 0x7f000000) {
+			set_h225_addr(skb, data, 0, &taddr[0],
+				      &ct->tuplehash[!dir].tuple.dst.u3,
+				      info->sig_port[!dir]);
+		}
+	} else {
+		nf_ct_unexpect_related(exp);
+		return -1;
+	}
+
+	/* Success */
+	pr_debug("nf_nat_ras: expect Q.931 %u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+		 NIPQUAD(exp->tuple.src.u3.ip),
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 NIPQUAD(exp->tuple.dst.u3.ip),
+		 ntohs(exp->tuple.dst.u.tcp.port));
+
+	return 0;
+}
+
+/****************************************************************************/
+static void ip_nat_callforwarding_expect(struct nf_conn *new,
+					 struct nf_conntrack_expect *this)
+{
+	struct nf_nat_range range;
+
+	/* This must be a fresh one. */
+	BUG_ON(new->status & IPS_NAT_DONE_MASK);
+
+	/* Change src to where master sends to */
+	range.flags = IP_NAT_RANGE_MAP_IPS;
+	range.min_ip = range.max_ip = new->tuplehash[!this->dir].tuple.src.u3.ip;
+	nf_nat_setup_info(new, &range, IP_NAT_MANIP_SRC);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
+	range.min = range.max = this->saved_proto;
+	range.min_ip = range.max_ip = this->saved_ip;
+	nf_nat_setup_info(new, &range, IP_NAT_MANIP_DST);
+}
+
+/****************************************************************************/
+static int nat_callforwarding(struct sk_buff *skb, struct nf_conn *ct,
+			      enum ip_conntrack_info ctinfo,
+			      unsigned char **data, int dataoff,
+			      TransportAddress *taddr, __be16 port,
+			      struct nf_conntrack_expect *exp)
+{
+	int dir = CTINFO2DIR(ctinfo);
+	u_int16_t nated_port;
+
+	/* Set expectations for NAT */
+	exp->saved_ip = exp->tuple.dst.u3.ip;
+	exp->tuple.dst.u3.ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->expectfn = ip_nat_callforwarding_expect;
+	exp->dir = !dir;
+
+	/* Try to get same port: if not, try to change it. */
+	for (nated_port = ntohs(port); nated_port != 0; nated_port++) {
+		exp->tuple.dst.u.tcp.port = htons(nated_port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (nated_port == 0) {	/* No port available */
+		if (net_ratelimit())
+			printk("nf_nat_q931: out of TCP ports\n");
+		return 0;
+	}
+
+	/* Modify signal */
+	if (!set_h225_addr(skb, data, dataoff, taddr,
+			   &ct->tuplehash[!dir].tuple.dst.u3,
+			   htons(nated_port)) == 0) {
+		nf_ct_unexpect_related(exp);
+		return -1;
+	}
+
+	/* Success */
+	pr_debug("nf_nat_q931: expect Call Forwarding "
+		 "%u.%u.%u.%u:%hu->%u.%u.%u.%u:%hu\n",
+		 NIPQUAD(exp->tuple.src.u3.ip),
+		 ntohs(exp->tuple.src.u.tcp.port),
+		 NIPQUAD(exp->tuple.dst.u3.ip),
+		 ntohs(exp->tuple.dst.u.tcp.port));
+
+	return 0;
+}
+
+/****************************************************************************/
+static int __init init(void)
+{
+	BUG_ON(set_h245_addr_hook != NULL);
+	BUG_ON(set_h225_addr_hook != NULL);
+	BUG_ON(set_sig_addr_hook != NULL);
+	BUG_ON(set_ras_addr_hook != NULL);
+	BUG_ON(nat_rtp_rtcp_hook != NULL);
+	BUG_ON(nat_t120_hook != NULL);
+	BUG_ON(nat_h245_hook != NULL);
+	BUG_ON(nat_callforwarding_hook != NULL);
+	BUG_ON(nat_q931_hook != NULL);
+
+	rcu_assign_pointer(set_h245_addr_hook, set_h245_addr);
+	rcu_assign_pointer(set_h225_addr_hook, set_h225_addr);
+	rcu_assign_pointer(set_sig_addr_hook, set_sig_addr);
+	rcu_assign_pointer(set_ras_addr_hook, set_ras_addr);
+	rcu_assign_pointer(nat_rtp_rtcp_hook, nat_rtp_rtcp);
+	rcu_assign_pointer(nat_t120_hook, nat_t120);
+	rcu_assign_pointer(nat_h245_hook, nat_h245);
+	rcu_assign_pointer(nat_callforwarding_hook, nat_callforwarding);
+	rcu_assign_pointer(nat_q931_hook, nat_q931);
+	return 0;
+}
+
+/****************************************************************************/
+static void __exit fini(void)
+{
+	rcu_assign_pointer(set_h245_addr_hook, NULL);
+	rcu_assign_pointer(set_h225_addr_hook, NULL);
+	rcu_assign_pointer(set_sig_addr_hook, NULL);
+	rcu_assign_pointer(set_ras_addr_hook, NULL);
+	rcu_assign_pointer(nat_rtp_rtcp_hook, NULL);
+	rcu_assign_pointer(nat_t120_hook, NULL);
+	rcu_assign_pointer(nat_h245_hook, NULL);
+	rcu_assign_pointer(nat_callforwarding_hook, NULL);
+	rcu_assign_pointer(nat_q931_hook, NULL);
+	synchronize_rcu();
+}
+
+/****************************************************************************/
+module_init(init);
+module_exit(fini);
+
+MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
+MODULE_DESCRIPTION("H.323 NAT helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat_h323");
diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
new file mode 100644
index 0000000..cf7a42b
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -0,0 +1,444 @@
+/* ip_nat_helper.c - generic support functions for NAT helpers
+ *
+ * (C) 2000-2002 Harald Welte <laforge@netfilter.org>
+ * (C) 2003-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <net/checksum.h>
+#include <net/tcp.h>
+#include <net/route.h>
+
+#include <linux/netfilter_ipv4.h>
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+
+#define DUMP_OFFSET(x) \
+	pr_debug("offset_before=%d, offset_after=%d, correction_pos=%u\n", \
+		 x->offset_before, x->offset_after, x->correction_pos);
+
+static DEFINE_SPINLOCK(nf_nat_seqofs_lock);
+
+/* Setup TCP sequence correction given this change at this sequence */
+static inline void
+adjust_tcp_sequence(u32 seq,
+		    int sizediff,
+		    struct nf_conn *ct,
+		    enum ip_conntrack_info ctinfo)
+{
+	int dir;
+	struct nf_nat_seq *this_way, *other_way;
+	struct nf_conn_nat *nat = nfct_nat(ct);
+
+	pr_debug("adjust_tcp_sequence: seq = %u, sizediff = %d\n", seq, seq);
+
+	dir = CTINFO2DIR(ctinfo);
+
+	this_way = &nat->seq[dir];
+	other_way = &nat->seq[!dir];
+
+	pr_debug("nf_nat_resize_packet: Seq_offset before: ");
+	DUMP_OFFSET(this_way);
+
+	spin_lock_bh(&nf_nat_seqofs_lock);
+
+	/* SYN adjust. If it's uninitialized, or this is after last
+	 * correction, record it: we don't handle more than one
+	 * adjustment in the window, but do deal with common case of a
+	 * retransmit */
+	if (this_way->offset_before == this_way->offset_after ||
+	    before(this_way->correction_pos, seq)) {
+		   this_way->correction_pos = seq;
+		   this_way->offset_before = this_way->offset_after;
+		   this_way->offset_after += sizediff;
+	}
+	spin_unlock_bh(&nf_nat_seqofs_lock);
+
+	pr_debug("nf_nat_resize_packet: Seq_offset after: ");
+	DUMP_OFFSET(this_way);
+}
+
+/* Frobs data inside this packet, which is linear. */
+static void mangle_contents(struct sk_buff *skb,
+			    unsigned int dataoff,
+			    unsigned int match_offset,
+			    unsigned int match_len,
+			    const char *rep_buffer,
+			    unsigned int rep_len)
+{
+	unsigned char *data;
+
+	BUG_ON(skb_is_nonlinear(skb));
+	data = skb_network_header(skb) + dataoff;
+
+	/* move post-replacement */
+	memmove(data + match_offset + rep_len,
+		data + match_offset + match_len,
+		skb->tail - (skb->network_header + dataoff +
+			     match_offset + match_len));
+
+	/* insert data from buffer */
+	memcpy(data + match_offset, rep_buffer, rep_len);
+
+	/* update skb info */
+	if (rep_len > match_len) {
+		pr_debug("nf_nat_mangle_packet: Extending packet by "
+			 "%u from %u bytes\n", rep_len - match_len, skb->len);
+		skb_put(skb, rep_len - match_len);
+	} else {
+		pr_debug("nf_nat_mangle_packet: Shrinking packet from "
+			 "%u from %u bytes\n", match_len - rep_len, skb->len);
+		__skb_trim(skb, skb->len + rep_len - match_len);
+	}
+
+	/* fix IP hdr checksum information */
+	ip_hdr(skb)->tot_len = htons(skb->len);
+	ip_send_check(ip_hdr(skb));
+}
+
+/* Unusual, but possible case. */
+static int enlarge_skb(struct sk_buff *skb, unsigned int extra)
+{
+	if (skb->len + extra > 65535)
+		return 0;
+
+	if (pskb_expand_head(skb, 0, extra - skb_tailroom(skb), GFP_ATOMIC))
+		return 0;
+
+	return 1;
+}
+
+/* Generic function for mangling variable-length address changes inside
+ * NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
+ * command in FTP).
+ *
+ * Takes care about all the nasty sequence number changes, checksumming,
+ * skb enlargement, ...
+ *
+ * */
+int
+nf_nat_mangle_tcp_packet(struct sk_buff *skb,
+			 struct nf_conn *ct,
+			 enum ip_conntrack_info ctinfo,
+			 unsigned int match_offset,
+			 unsigned int match_len,
+			 const char *rep_buffer,
+			 unsigned int rep_len)
+{
+	struct rtable *rt = skb->rtable;
+	struct iphdr *iph;
+	struct tcphdr *tcph;
+	int oldlen, datalen;
+
+	if (!skb_make_writable(skb, skb->len))
+		return 0;
+
+	if (rep_len > match_len &&
+	    rep_len - match_len > skb_tailroom(skb) &&
+	    !enlarge_skb(skb, rep_len - match_len))
+		return 0;
+
+	SKB_LINEAR_ASSERT(skb);
+
+	iph = ip_hdr(skb);
+	tcph = (void *)iph + iph->ihl*4;
+
+	oldlen = skb->len - iph->ihl*4;
+	mangle_contents(skb, iph->ihl*4 + tcph->doff*4,
+			match_offset, match_len, rep_buffer, rep_len);
+
+	datalen = skb->len - iph->ihl*4;
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		if (!(rt->rt_flags & RTCF_LOCAL) &&
+		    skb->dev->features & NETIF_F_V4_CSUM) {
+			skb->ip_summed = CHECKSUM_PARTIAL;
+			skb->csum_start = skb_headroom(skb) +
+					  skb_network_offset(skb) +
+					  iph->ihl * 4;
+			skb->csum_offset = offsetof(struct tcphdr, check);
+			tcph->check = ~tcp_v4_check(datalen,
+						    iph->saddr, iph->daddr, 0);
+		} else {
+			tcph->check = 0;
+			tcph->check = tcp_v4_check(datalen,
+						   iph->saddr, iph->daddr,
+						   csum_partial(tcph,
+								datalen, 0));
+		}
+	} else
+		inet_proto_csum_replace2(&tcph->check, skb,
+					 htons(oldlen), htons(datalen), 1);
+
+	if (rep_len != match_len) {
+		set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
+		adjust_tcp_sequence(ntohl(tcph->seq),
+				    (int)rep_len - (int)match_len,
+				    ct, ctinfo);
+		/* Tell TCP window tracking about seq change */
+		nf_conntrack_tcp_update(skb, ip_hdrlen(skb),
+					ct, CTINFO2DIR(ctinfo));
+
+		nf_conntrack_event_cache(IPCT_NATSEQADJ, ct);
+	}
+	return 1;
+}
+EXPORT_SYMBOL(nf_nat_mangle_tcp_packet);
+
+/* Generic function for mangling variable-length address changes inside
+ * NATed UDP connections (like the CONNECT DATA XXXXX MESG XXXXX INDEX XXXXX
+ * command in the Amanda protocol)
+ *
+ * Takes care about all the nasty sequence number changes, checksumming,
+ * skb enlargement, ...
+ *
+ * XXX - This function could be merged with nf_nat_mangle_tcp_packet which
+ *       should be fairly easy to do.
+ */
+int
+nf_nat_mangle_udp_packet(struct sk_buff *skb,
+			 struct nf_conn *ct,
+			 enum ip_conntrack_info ctinfo,
+			 unsigned int match_offset,
+			 unsigned int match_len,
+			 const char *rep_buffer,
+			 unsigned int rep_len)
+{
+	struct rtable *rt = skb->rtable;
+	struct iphdr *iph;
+	struct udphdr *udph;
+	int datalen, oldlen;
+
+	/* UDP helpers might accidentally mangle the wrong packet */
+	iph = ip_hdr(skb);
+	if (skb->len < iph->ihl*4 + sizeof(*udph) +
+			       match_offset + match_len)
+		return 0;
+
+	if (!skb_make_writable(skb, skb->len))
+		return 0;
+
+	if (rep_len > match_len &&
+	    rep_len - match_len > skb_tailroom(skb) &&
+	    !enlarge_skb(skb, rep_len - match_len))
+		return 0;
+
+	iph = ip_hdr(skb);
+	udph = (void *)iph + iph->ihl*4;
+
+	oldlen = skb->len - iph->ihl*4;
+	mangle_contents(skb, iph->ihl*4 + sizeof(*udph),
+			match_offset, match_len, rep_buffer, rep_len);
+
+	/* update the length of the UDP packet */
+	datalen = skb->len - iph->ihl*4;
+	udph->len = htons(datalen);
+
+	/* fix udp checksum if udp checksum was previously calculated */
+	if (!udph->check && skb->ip_summed != CHECKSUM_PARTIAL)
+		return 1;
+
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		if (!(rt->rt_flags & RTCF_LOCAL) &&
+		    skb->dev->features & NETIF_F_V4_CSUM) {
+			skb->ip_summed = CHECKSUM_PARTIAL;
+			skb->csum_start = skb_headroom(skb) +
+					  skb_network_offset(skb) +
+					  iph->ihl * 4;
+			skb->csum_offset = offsetof(struct udphdr, check);
+			udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
+							 datalen, IPPROTO_UDP,
+							 0);
+		} else {
+			udph->check = 0;
+			udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+							datalen, IPPROTO_UDP,
+							csum_partial(udph,
+								     datalen, 0));
+			if (!udph->check)
+				udph->check = CSUM_MANGLED_0;
+		}
+	} else
+		inet_proto_csum_replace2(&udph->check, skb,
+					 htons(oldlen), htons(datalen), 1);
+
+	return 1;
+}
+EXPORT_SYMBOL(nf_nat_mangle_udp_packet);
+
+/* Adjust one found SACK option including checksum correction */
+static void
+sack_adjust(struct sk_buff *skb,
+	    struct tcphdr *tcph,
+	    unsigned int sackoff,
+	    unsigned int sackend,
+	    struct nf_nat_seq *natseq)
+{
+	while (sackoff < sackend) {
+		struct tcp_sack_block_wire *sack;
+		__be32 new_start_seq, new_end_seq;
+
+		sack = (void *)skb->data + sackoff;
+		if (after(ntohl(sack->start_seq) - natseq->offset_before,
+			  natseq->correction_pos))
+			new_start_seq = htonl(ntohl(sack->start_seq)
+					- natseq->offset_after);
+		else
+			new_start_seq = htonl(ntohl(sack->start_seq)
+					- natseq->offset_before);
+
+		if (after(ntohl(sack->end_seq) - natseq->offset_before,
+			  natseq->correction_pos))
+			new_end_seq = htonl(ntohl(sack->end_seq)
+				      - natseq->offset_after);
+		else
+			new_end_seq = htonl(ntohl(sack->end_seq)
+				      - natseq->offset_before);
+
+		pr_debug("sack_adjust: start_seq: %d->%d, end_seq: %d->%d\n",
+			 ntohl(sack->start_seq), new_start_seq,
+			 ntohl(sack->end_seq), new_end_seq);
+
+		inet_proto_csum_replace4(&tcph->check, skb,
+					 sack->start_seq, new_start_seq, 0);
+		inet_proto_csum_replace4(&tcph->check, skb,
+					 sack->end_seq, new_end_seq, 0);
+		sack->start_seq = new_start_seq;
+		sack->end_seq = new_end_seq;
+		sackoff += sizeof(*sack);
+	}
+}
+
+/* TCP SACK sequence number adjustment */
+static inline unsigned int
+nf_nat_sack_adjust(struct sk_buff *skb,
+		   struct tcphdr *tcph,
+		   struct nf_conn *ct,
+		   enum ip_conntrack_info ctinfo)
+{
+	unsigned int dir, optoff, optend;
+	struct nf_conn_nat *nat = nfct_nat(ct);
+
+	optoff = ip_hdrlen(skb) + sizeof(struct tcphdr);
+	optend = ip_hdrlen(skb) + tcph->doff * 4;
+
+	if (!skb_make_writable(skb, optend))
+		return 0;
+
+	dir = CTINFO2DIR(ctinfo);
+
+	while (optoff < optend) {
+		/* Usually: option, length. */
+		unsigned char *op = skb->data + optoff;
+
+		switch (op[0]) {
+		case TCPOPT_EOL:
+			return 1;
+		case TCPOPT_NOP:
+			optoff++;
+			continue;
+		default:
+			/* no partial options */
+			if (optoff + 1 == optend ||
+			    optoff + op[1] > optend ||
+			    op[1] < 2)
+				return 0;
+			if (op[0] == TCPOPT_SACK &&
+			    op[1] >= 2+TCPOLEN_SACK_PERBLOCK &&
+			    ((op[1] - 2) % TCPOLEN_SACK_PERBLOCK) == 0)
+				sack_adjust(skb, tcph, optoff+2,
+					    optoff+op[1], &nat->seq[!dir]);
+			optoff += op[1];
+		}
+	}
+	return 1;
+}
+
+/* TCP sequence number adjustment.  Returns 1 on success, 0 on failure */
+int
+nf_nat_seq_adjust(struct sk_buff *skb,
+		  struct nf_conn *ct,
+		  enum ip_conntrack_info ctinfo)
+{
+	struct tcphdr *tcph;
+	int dir;
+	__be32 newseq, newack;
+	struct nf_conn_nat *nat = nfct_nat(ct);
+	struct nf_nat_seq *this_way, *other_way;
+
+	dir = CTINFO2DIR(ctinfo);
+
+	this_way = &nat->seq[dir];
+	other_way = &nat->seq[!dir];
+
+	if (!skb_make_writable(skb, ip_hdrlen(skb) + sizeof(*tcph)))
+		return 0;
+
+	tcph = (void *)skb->data + ip_hdrlen(skb);
+	if (after(ntohl(tcph->seq), this_way->correction_pos))
+		newseq = htonl(ntohl(tcph->seq) + this_way->offset_after);
+	else
+		newseq = htonl(ntohl(tcph->seq) + this_way->offset_before);
+
+	if (after(ntohl(tcph->ack_seq) - other_way->offset_before,
+		  other_way->correction_pos))
+		newack = htonl(ntohl(tcph->ack_seq) - other_way->offset_after);
+	else
+		newack = htonl(ntohl(tcph->ack_seq) - other_way->offset_before);
+
+	inet_proto_csum_replace4(&tcph->check, skb, tcph->seq, newseq, 0);
+	inet_proto_csum_replace4(&tcph->check, skb, tcph->ack_seq, newack, 0);
+
+	pr_debug("Adjusting sequence number from %u->%u, ack from %u->%u\n",
+		 ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq),
+		 ntohl(newack));
+
+	tcph->seq = newseq;
+	tcph->ack_seq = newack;
+
+	if (!nf_nat_sack_adjust(skb, tcph, ct, ctinfo))
+		return 0;
+
+	nf_conntrack_tcp_update(skb, ip_hdrlen(skb), ct, dir);
+
+	return 1;
+}
+
+/* Setup NAT on this expected conntrack so it follows master. */
+/* If we fail to get a free NAT slot, we'll get dropped on confirm */
+void nf_nat_follow_master(struct nf_conn *ct,
+			  struct nf_conntrack_expect *exp)
+{
+	struct nf_nat_range range;
+
+	/* This must be a fresh one. */
+	BUG_ON(ct->status & IPS_NAT_DONE_MASK);
+
+	/* Change src to where master sends to */
+	range.flags = IP_NAT_RANGE_MAP_IPS;
+	range.min_ip = range.max_ip
+		= ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
+	range.min = range.max = exp->saved_proto;
+	range.min_ip = range.max_ip
+		= ct->master->tuplehash[!exp->dir].tuple.src.u3.ip;
+	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_DST);
+}
+EXPORT_SYMBOL(nf_nat_follow_master);
diff --git a/net/ipv4/netfilter/nf_nat_irc.c b/net/ipv4/netfilter/nf_nat_irc.c
new file mode 100644
index 0000000..fe6f9ce
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_irc.c
@@ -0,0 +1,92 @@
+/* IRC extension for TCP NAT alteration.
+ *
+ * (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2004 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
+ * based on a copy of RR's ip_nat_ftp.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/tcp.h>
+#include <linux/kernel.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_irc.h>
+
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("IRC (DCC) NAT helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat_irc");
+
+static unsigned int help(struct sk_buff *skb,
+			 enum ip_conntrack_info ctinfo,
+			 unsigned int matchoff,
+			 unsigned int matchlen,
+			 struct nf_conntrack_expect *exp)
+{
+	char buffer[sizeof("4294967296 65635")];
+	u_int32_t ip;
+	u_int16_t port;
+	unsigned int ret;
+
+	/* Reply comes from server. */
+	exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
+	exp->dir = IP_CT_DIR_REPLY;
+	exp->expectfn = nf_nat_follow_master;
+
+	/* Try to get same port: if not, try to change it. */
+	for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
+		exp->tuple.dst.u.tcp.port = htons(port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (port == 0)
+		return NF_DROP;
+
+	ip = ntohl(exp->master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);
+	sprintf(buffer, "%u %u", ip, port);
+	pr_debug("nf_nat_irc: inserting '%s' == %u.%u.%u.%u, port %u\n",
+		 buffer, NIPQUAD(ip), port);
+
+	ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo,
+				       matchoff, matchlen, buffer,
+				       strlen(buffer));
+	if (ret != NF_ACCEPT)
+		nf_ct_unexpect_related(exp);
+	return ret;
+}
+
+static void __exit nf_nat_irc_fini(void)
+{
+	rcu_assign_pointer(nf_nat_irc_hook, NULL);
+	synchronize_rcu();
+}
+
+static int __init nf_nat_irc_init(void)
+{
+	BUG_ON(nf_nat_irc_hook != NULL);
+	rcu_assign_pointer(nf_nat_irc_hook, help);
+	return 0;
+}
+
+/* Prior to 2.6.11, we had a ports param.  No longer, but don't break users. */
+static int warn_set(const char *val, struct kernel_param *kp)
+{
+	printk(KERN_INFO KBUILD_MODNAME
+	       ": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n");
+	return 0;
+}
+module_param_call(ports, warn_set, NULL, NULL, 0);
+
+module_init(nf_nat_irc_init);
+module_exit(nf_nat_irc_fini);
diff --git a/net/ipv4/netfilter/nf_nat_pptp.c b/net/ipv4/netfilter/nf_nat_pptp.c
new file mode 100644
index 0000000..9eb1710
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_pptp.c
@@ -0,0 +1,307 @@
+/*
+ * nf_nat_pptp.c
+ *
+ * NAT support for PPTP (Point to Point Tunneling Protocol).
+ * PPTP is a a protocol for creating virtual private networks.
+ * It is a specification defined by Microsoft and some vendors
+ * working with Microsoft.  PPTP is built on top of a modified
+ * version of the Internet Generic Routing Encapsulation Protocol.
+ * GRE is defined in RFC 1701 and RFC 1702.  Documentation of
+ * PPTP can be found in RFC 2637
+ *
+ * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ *
+ * TODO: - NAT to a unique tuple, not to TCP source port
+ * 	   (needs netfilter tuple reservation)
+ */
+
+#include <linux/module.h>
+#include <linux/tcp.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_proto_gre.h>
+#include <linux/netfilter/nf_conntrack_pptp.h>
+
+#define NF_NAT_PPTP_VERSION "3.0"
+
+#define REQ_CID(req, off)		(*(__be16 *)((char *)(req) + (off)))
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("Netfilter NAT helper module for PPTP");
+MODULE_ALIAS("ip_nat_pptp");
+
+static void pptp_nat_expected(struct nf_conn *ct,
+			      struct nf_conntrack_expect *exp)
+{
+	struct net *net = nf_ct_net(ct);
+	const struct nf_conn *master = ct->master;
+	struct nf_conntrack_expect *other_exp;
+	struct nf_conntrack_tuple t;
+	const struct nf_ct_pptp_master *ct_pptp_info;
+	const struct nf_nat_pptp *nat_pptp_info;
+	struct nf_nat_range range;
+
+	ct_pptp_info = &nfct_help(master)->help.ct_pptp_info;
+	nat_pptp_info = &nfct_nat(master)->help.nat_pptp_info;
+
+	/* And here goes the grand finale of corrosion... */
+	if (exp->dir == IP_CT_DIR_ORIGINAL) {
+		pr_debug("we are PNS->PAC\n");
+		/* therefore, build tuple for PAC->PNS */
+		t.src.l3num = AF_INET;
+		t.src.u3.ip = master->tuplehash[!exp->dir].tuple.src.u3.ip;
+		t.src.u.gre.key = ct_pptp_info->pac_call_id;
+		t.dst.u3.ip = master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+		t.dst.u.gre.key = ct_pptp_info->pns_call_id;
+		t.dst.protonum = IPPROTO_GRE;
+	} else {
+		pr_debug("we are PAC->PNS\n");
+		/* build tuple for PNS->PAC */
+		t.src.l3num = AF_INET;
+		t.src.u3.ip = master->tuplehash[!exp->dir].tuple.src.u3.ip;
+		t.src.u.gre.key = nat_pptp_info->pns_call_id;
+		t.dst.u3.ip = master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+		t.dst.u.gre.key = nat_pptp_info->pac_call_id;
+		t.dst.protonum = IPPROTO_GRE;
+	}
+
+	pr_debug("trying to unexpect other dir: ");
+	nf_ct_dump_tuple_ip(&t);
+	other_exp = nf_ct_expect_find_get(net, &t);
+	if (other_exp) {
+		nf_ct_unexpect_related(other_exp);
+		nf_ct_expect_put(other_exp);
+		pr_debug("success\n");
+	} else {
+		pr_debug("not found!\n");
+	}
+
+	/* This must be a fresh one. */
+	BUG_ON(ct->status & IPS_NAT_DONE_MASK);
+
+	/* Change src to where master sends to */
+	range.flags = IP_NAT_RANGE_MAP_IPS;
+	range.min_ip = range.max_ip
+		= ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+	if (exp->dir == IP_CT_DIR_ORIGINAL) {
+		range.flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+		range.min = range.max = exp->saved_proto;
+	}
+	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = IP_NAT_RANGE_MAP_IPS;
+	range.min_ip = range.max_ip
+		= ct->master->tuplehash[!exp->dir].tuple.src.u3.ip;
+	if (exp->dir == IP_CT_DIR_REPLY) {
+		range.flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+		range.min = range.max = exp->saved_proto;
+	}
+	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_DST);
+}
+
+/* outbound packets == from PNS to PAC */
+static int
+pptp_outbound_pkt(struct sk_buff *skb,
+		  struct nf_conn *ct,
+		  enum ip_conntrack_info ctinfo,
+		  struct PptpControlHeader *ctlh,
+		  union pptp_ctrl_union *pptpReq)
+
+{
+	struct nf_ct_pptp_master *ct_pptp_info;
+	struct nf_nat_pptp *nat_pptp_info;
+	u_int16_t msg;
+	__be16 new_callid;
+	unsigned int cid_off;
+
+	ct_pptp_info  = &nfct_help(ct)->help.ct_pptp_info;
+	nat_pptp_info = &nfct_nat(ct)->help.nat_pptp_info;
+
+	new_callid = ct_pptp_info->pns_call_id;
+
+	switch (msg = ntohs(ctlh->messageType)) {
+	case PPTP_OUT_CALL_REQUEST:
+		cid_off = offsetof(union pptp_ctrl_union, ocreq.callID);
+		/* FIXME: ideally we would want to reserve a call ID
+		 * here.  current netfilter NAT core is not able to do
+		 * this :( For now we use TCP source port. This breaks
+		 * multiple calls within one control session */
+
+		/* save original call ID in nat_info */
+		nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id;
+
+		/* don't use tcph->source since we are at a DSTmanip
+		 * hook (e.g. PREROUTING) and pkt is not mangled yet */
+		new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
+
+		/* save new call ID in ct info */
+		ct_pptp_info->pns_call_id = new_callid;
+		break;
+	case PPTP_IN_CALL_REPLY:
+		cid_off = offsetof(union pptp_ctrl_union, icack.callID);
+		break;
+	case PPTP_CALL_CLEAR_REQUEST:
+		cid_off = offsetof(union pptp_ctrl_union, clrreq.callID);
+		break;
+	default:
+		pr_debug("unknown outbound packet 0x%04x:%s\n", msg,
+			 msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] :
+					       pptp_msg_name[0]);
+		/* fall through */
+	case PPTP_SET_LINK_INFO:
+		/* only need to NAT in case PAC is behind NAT box */
+	case PPTP_START_SESSION_REQUEST:
+	case PPTP_START_SESSION_REPLY:
+	case PPTP_STOP_SESSION_REQUEST:
+	case PPTP_STOP_SESSION_REPLY:
+	case PPTP_ECHO_REQUEST:
+	case PPTP_ECHO_REPLY:
+		/* no need to alter packet */
+		return NF_ACCEPT;
+	}
+
+	/* only OUT_CALL_REQUEST, IN_CALL_REPLY, CALL_CLEAR_REQUEST pass
+	 * down to here */
+	pr_debug("altering call id from 0x%04x to 0x%04x\n",
+		 ntohs(REQ_CID(pptpReq, cid_off)), ntohs(new_callid));
+
+	/* mangle packet */
+	if (nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+				     cid_off + sizeof(struct pptp_pkt_hdr) +
+				     sizeof(struct PptpControlHeader),
+				     sizeof(new_callid), (char *)&new_callid,
+				     sizeof(new_callid)) == 0)
+		return NF_DROP;
+	return NF_ACCEPT;
+}
+
+static void
+pptp_exp_gre(struct nf_conntrack_expect *expect_orig,
+	     struct nf_conntrack_expect *expect_reply)
+{
+	const struct nf_conn *ct = expect_orig->master;
+	struct nf_ct_pptp_master *ct_pptp_info;
+	struct nf_nat_pptp *nat_pptp_info;
+
+	ct_pptp_info  = &nfct_help(ct)->help.ct_pptp_info;
+	nat_pptp_info = &nfct_nat(ct)->help.nat_pptp_info;
+
+	/* save original PAC call ID in nat_info */
+	nat_pptp_info->pac_call_id = ct_pptp_info->pac_call_id;
+
+	/* alter expectation for PNS->PAC direction */
+	expect_orig->saved_proto.gre.key = ct_pptp_info->pns_call_id;
+	expect_orig->tuple.src.u.gre.key = nat_pptp_info->pns_call_id;
+	expect_orig->tuple.dst.u.gre.key = ct_pptp_info->pac_call_id;
+	expect_orig->dir = IP_CT_DIR_ORIGINAL;
+
+	/* alter expectation for PAC->PNS direction */
+	expect_reply->saved_proto.gre.key = nat_pptp_info->pns_call_id;
+	expect_reply->tuple.src.u.gre.key = nat_pptp_info->pac_call_id;
+	expect_reply->tuple.dst.u.gre.key = ct_pptp_info->pns_call_id;
+	expect_reply->dir = IP_CT_DIR_REPLY;
+}
+
+/* inbound packets == from PAC to PNS */
+static int
+pptp_inbound_pkt(struct sk_buff *skb,
+		 struct nf_conn *ct,
+		 enum ip_conntrack_info ctinfo,
+		 struct PptpControlHeader *ctlh,
+		 union pptp_ctrl_union *pptpReq)
+{
+	const struct nf_nat_pptp *nat_pptp_info;
+	u_int16_t msg;
+	__be16 new_pcid;
+	unsigned int pcid_off;
+
+	nat_pptp_info = &nfct_nat(ct)->help.nat_pptp_info;
+	new_pcid = nat_pptp_info->pns_call_id;
+
+	switch (msg = ntohs(ctlh->messageType)) {
+	case PPTP_OUT_CALL_REPLY:
+		pcid_off = offsetof(union pptp_ctrl_union, ocack.peersCallID);
+		break;
+	case PPTP_IN_CALL_CONNECT:
+		pcid_off = offsetof(union pptp_ctrl_union, iccon.peersCallID);
+		break;
+	case PPTP_IN_CALL_REQUEST:
+		/* only need to nat in case PAC is behind NAT box */
+		return NF_ACCEPT;
+	case PPTP_WAN_ERROR_NOTIFY:
+		pcid_off = offsetof(union pptp_ctrl_union, wanerr.peersCallID);
+		break;
+	case PPTP_CALL_DISCONNECT_NOTIFY:
+		pcid_off = offsetof(union pptp_ctrl_union, disc.callID);
+		break;
+	case PPTP_SET_LINK_INFO:
+		pcid_off = offsetof(union pptp_ctrl_union, setlink.peersCallID);
+		break;
+	default:
+		pr_debug("unknown inbound packet %s\n",
+			 msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] :
+					       pptp_msg_name[0]);
+		/* fall through */
+	case PPTP_START_SESSION_REQUEST:
+	case PPTP_START_SESSION_REPLY:
+	case PPTP_STOP_SESSION_REQUEST:
+	case PPTP_STOP_SESSION_REPLY:
+	case PPTP_ECHO_REQUEST:
+	case PPTP_ECHO_REPLY:
+		/* no need to alter packet */
+		return NF_ACCEPT;
+	}
+
+	/* only OUT_CALL_REPLY, IN_CALL_CONNECT, IN_CALL_REQUEST,
+	 * WAN_ERROR_NOTIFY, CALL_DISCONNECT_NOTIFY pass down here */
+
+	/* mangle packet */
+	pr_debug("altering peer call id from 0x%04x to 0x%04x\n",
+		 ntohs(REQ_CID(pptpReq, pcid_off)), ntohs(new_pcid));
+
+	if (nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
+				     pcid_off + sizeof(struct pptp_pkt_hdr) +
+				     sizeof(struct PptpControlHeader),
+				     sizeof(new_pcid), (char *)&new_pcid,
+				     sizeof(new_pcid)) == 0)
+		return NF_DROP;
+	return NF_ACCEPT;
+}
+
+static int __init nf_nat_helper_pptp_init(void)
+{
+	nf_nat_need_gre();
+
+	BUG_ON(nf_nat_pptp_hook_outbound != NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_outbound, pptp_outbound_pkt);
+
+	BUG_ON(nf_nat_pptp_hook_inbound != NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_inbound, pptp_inbound_pkt);
+
+	BUG_ON(nf_nat_pptp_hook_exp_gre != NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_exp_gre, pptp_exp_gre);
+
+	BUG_ON(nf_nat_pptp_hook_expectfn != NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_expectfn, pptp_nat_expected);
+	return 0;
+}
+
+static void __exit nf_nat_helper_pptp_fini(void)
+{
+	rcu_assign_pointer(nf_nat_pptp_hook_expectfn, NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_exp_gre, NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_inbound, NULL);
+	rcu_assign_pointer(nf_nat_pptp_hook_outbound, NULL);
+	synchronize_rcu();
+}
+
+module_init(nf_nat_helper_pptp_init);
+module_exit(nf_nat_helper_pptp_fini);
diff --git a/net/ipv4/netfilter/nf_nat_proto_common.c b/net/ipv4/netfilter/nf_nat_proto_common.c
new file mode 100644
index 0000000..6c4f11f
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_common.c
@@ -0,0 +1,124 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/random.h>
+#include <linux/ip.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+bool nf_nat_proto_in_range(const struct nf_conntrack_tuple *tuple,
+			   enum nf_nat_manip_type maniptype,
+			   const union nf_conntrack_man_proto *min,
+			   const union nf_conntrack_man_proto *max)
+{
+	__be16 port;
+
+	if (maniptype == IP_NAT_MANIP_SRC)
+		port = tuple->src.u.all;
+	else
+		port = tuple->dst.u.all;
+
+	return ntohs(port) >= ntohs(min->all) &&
+	       ntohs(port) <= ntohs(max->all);
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_in_range);
+
+bool nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,
+			       const struct nf_nat_range *range,
+			       enum nf_nat_manip_type maniptype,
+			       const struct nf_conn *ct,
+			       u_int16_t *rover)
+{
+	unsigned int range_size, min, i;
+	__be16 *portptr;
+	u_int16_t off;
+
+	if (maniptype == IP_NAT_MANIP_SRC)
+		portptr = &tuple->src.u.all;
+	else
+		portptr = &tuple->dst.u.all;
+
+	/* If no range specified... */
+	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
+		/* If it's dst rewrite, can't change port */
+		if (maniptype == IP_NAT_MANIP_DST)
+			return false;
+
+		if (ntohs(*portptr) < 1024) {
+			/* Loose convention: >> 512 is credential passing */
+			if (ntohs(*portptr) < 512) {
+				min = 1;
+				range_size = 511 - min + 1;
+			} else {
+				min = 600;
+				range_size = 1023 - min + 1;
+			}
+		} else {
+			min = 1024;
+			range_size = 65535 - 1024 + 1;
+		}
+	} else {
+		min = ntohs(range->min.all);
+		range_size = ntohs(range->max.all) - min + 1;
+	}
+
+	if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)
+		off = secure_ipv4_port_ephemeral(tuple->src.u3.ip, tuple->dst.u3.ip,
+						 maniptype == IP_NAT_MANIP_SRC
+						 ? tuple->dst.u.all
+						 : tuple->src.u.all);
+	else
+		off = *rover;
+
+	for (i = 0; i < range_size; i++, off++) {
+		*portptr = htons(min + off % range_size);
+		if (nf_nat_used_tuple(tuple, ct))
+			continue;
+		if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM))
+			*rover = off;
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple);
+
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+int nf_nat_proto_range_to_nlattr(struct sk_buff *skb,
+				 const struct nf_nat_range *range)
+{
+	NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MIN, range->min.all);
+	NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MAX, range->max.all);
+	return 0;
+
+nla_put_failure:
+	return -1;
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_nlattr_to_range);
+
+int nf_nat_proto_nlattr_to_range(struct nlattr *tb[],
+				 struct nf_nat_range *range)
+{
+	if (tb[CTA_PROTONAT_PORT_MIN]) {
+		range->min.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]);
+		range->max.all = range->min.tcp.port;
+		range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+	}
+	if (tb[CTA_PROTONAT_PORT_MAX]) {
+		range->max.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]);
+		range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_nat_proto_range_to_nlattr);
+#endif
diff --git a/net/ipv4/netfilter/nf_nat_proto_dccp.c b/net/ipv4/netfilter/nf_nat_proto_dccp.c
new file mode 100644
index 0000000..22485ce
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_dccp.c
@@ -0,0 +1,108 @@
+/*
+ * DCCP NAT protocol helper
+ *
+ * Copyright (c) 2005, 2006. 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/dccp.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static u_int16_t dccp_port_rover;
+
+static bool
+dccp_unique_tuple(struct nf_conntrack_tuple *tuple,
+		  const struct nf_nat_range *range,
+		  enum nf_nat_manip_type maniptype,
+		  const struct nf_conn *ct)
+{
+	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+					 &dccp_port_rover);
+}
+
+static bool
+dccp_manip_pkt(struct sk_buff *skb,
+	       unsigned int iphdroff,
+	       const struct nf_conntrack_tuple *tuple,
+	       enum nf_nat_manip_type maniptype)
+{
+	const struct iphdr *iph = (const void *)(skb->data + iphdroff);
+	struct dccp_hdr *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl * 4;
+	__be32 oldip, newip;
+	__be16 *portptr, oldport, newport;
+	int hdrsize = 8; /* DCCP connection tracking guarantees this much */
+
+	if (skb->len >= hdroff + sizeof(struct dccp_hdr))
+		hdrsize = sizeof(struct dccp_hdr);
+
+	if (!skb_make_writable(skb, hdroff + hdrsize))
+		return false;
+
+	iph = (struct iphdr *)(skb->data + iphdroff);
+	hdr = (struct dccp_hdr *)(skb->data + hdroff);
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		oldip = iph->saddr;
+		newip = tuple->src.u3.ip;
+		newport = tuple->src.u.dccp.port;
+		portptr = &hdr->dccph_sport;
+	} else {
+		oldip = iph->daddr;
+		newip = tuple->dst.u3.ip;
+		newport = tuple->dst.u.dccp.port;
+		portptr = &hdr->dccph_dport;
+	}
+
+	oldport = *portptr;
+	*portptr = newport;
+
+	if (hdrsize < sizeof(*hdr))
+		return true;
+
+	inet_proto_csum_replace4(&hdr->dccph_checksum, skb, oldip, newip, 1);
+	inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport,
+				 0);
+	return true;
+}
+
+static const struct nf_nat_protocol nf_nat_protocol_dccp = {
+	.protonum		= IPPROTO_DCCP,
+	.me			= THIS_MODULE,
+	.manip_pkt		= dccp_manip_pkt,
+	.in_range		= nf_nat_proto_in_range,
+	.unique_tuple		= dccp_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
+
+static int __init nf_nat_proto_dccp_init(void)
+{
+	return nf_nat_protocol_register(&nf_nat_protocol_dccp);
+}
+
+static void __exit nf_nat_proto_dccp_fini(void)
+{
+	nf_nat_protocol_unregister(&nf_nat_protocol_dccp);
+}
+
+module_init(nf_nat_proto_dccp_init);
+module_exit(nf_nat_proto_dccp_fini);
+
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("DCCP NAT protocol helper");
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/netfilter/nf_nat_proto_gre.c b/net/ipv4/netfilter/nf_nat_proto_gre.c
new file mode 100644
index 0000000..d7e8920
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_gre.c
@@ -0,0 +1,149 @@
+/*
+ * nf_nat_proto_gre.c
+ *
+ * NAT protocol helper module for GRE.
+ *
+ * GRE is a generic encapsulation protocol, which is generally not very
+ * suited for NAT, as it has no protocol-specific part as port numbers.
+ *
+ * It has an optional key field, which may help us distinguishing two
+ * connections between the same two hosts.
+ *
+ * GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784
+ *
+ * PPTP is built on top of a modified version of GRE, and has a mandatory
+ * field called "CallID", which serves us for the same purpose as the key
+ * field in plain GRE.
+ *
+ * Documentation about PPTP can be found in RFC 2637
+ *
+ * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Development of this code funded by Astaro AG (http://www.astaro.com/)
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <linux/netfilter/nf_conntrack_proto_gre.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
+MODULE_DESCRIPTION("Netfilter NAT protocol helper module for GRE");
+
+/* generate unique tuple ... */
+static bool
+gre_unique_tuple(struct nf_conntrack_tuple *tuple,
+		 const struct nf_nat_range *range,
+		 enum nf_nat_manip_type maniptype,
+		 const struct nf_conn *ct)
+{
+	static u_int16_t key;
+	__be16 *keyptr;
+	unsigned int min, i, range_size;
+
+	/* If there is no master conntrack we are not PPTP,
+	   do not change tuples */
+	if (!ct->master)
+		return false;
+
+	if (maniptype == IP_NAT_MANIP_SRC)
+		keyptr = &tuple->src.u.gre.key;
+	else
+		keyptr = &tuple->dst.u.gre.key;
+
+	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
+		pr_debug("%p: NATing GRE PPTP\n", ct);
+		min = 1;
+		range_size = 0xffff;
+	} else {
+		min = ntohs(range->min.gre.key);
+		range_size = ntohs(range->max.gre.key) - min + 1;
+	}
+
+	pr_debug("min = %u, range_size = %u\n", min, range_size);
+
+	for (i = 0; i < range_size; i++, key++) {
+		*keyptr = htons(min + key % range_size);
+		if (!nf_nat_used_tuple(tuple, ct))
+			return true;
+	}
+
+	pr_debug("%p: no NAT mapping\n", ct);
+	return false;
+}
+
+/* manipulate a GRE packet according to maniptype */
+static bool
+gre_manip_pkt(struct sk_buff *skb, unsigned int iphdroff,
+	      const struct nf_conntrack_tuple *tuple,
+	      enum nf_nat_manip_type maniptype)
+{
+	const struct gre_hdr *greh;
+	struct gre_hdr_pptp *pgreh;
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	unsigned int hdroff = iphdroff + iph->ihl * 4;
+
+	/* pgreh includes two optional 32bit fields which are not required
+	 * to be there.  That's where the magic '8' comes from */
+	if (!skb_make_writable(skb, hdroff + sizeof(*pgreh) - 8))
+		return false;
+
+	greh = (void *)skb->data + hdroff;
+	pgreh = (struct gre_hdr_pptp *)greh;
+
+	/* we only have destination manip of a packet, since 'source key'
+	 * is not present in the packet itself */
+	if (maniptype != IP_NAT_MANIP_DST)
+		return true;
+	switch (greh->version) {
+	case GRE_VERSION_1701:
+		/* We do not currently NAT any GREv0 packets.
+		 * Try to behave like "nf_nat_proto_unknown" */
+		break;
+	case GRE_VERSION_PPTP:
+		pr_debug("call_id -> 0x%04x\n", ntohs(tuple->dst.u.gre.key));
+		pgreh->call_id = tuple->dst.u.gre.key;
+		break;
+	default:
+		pr_debug("can't nat unknown GRE version\n");
+		return false;
+	}
+	return true;
+}
+
+static const struct nf_nat_protocol gre = {
+	.protonum		= IPPROTO_GRE,
+	.me			= THIS_MODULE,
+	.manip_pkt		= gre_manip_pkt,
+	.in_range		= nf_nat_proto_in_range,
+	.unique_tuple		= gre_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
+
+static int __init nf_nat_proto_gre_init(void)
+{
+	return nf_nat_protocol_register(&gre);
+}
+
+static void __exit nf_nat_proto_gre_fini(void)
+{
+	nf_nat_protocol_unregister(&gre);
+}
+
+module_init(nf_nat_proto_gre_init);
+module_exit(nf_nat_proto_gre_fini);
+
+void nf_nat_need_gre(void)
+{
+	return;
+}
+EXPORT_SYMBOL_GPL(nf_nat_need_gre);
diff --git a/net/ipv4/netfilter/nf_nat_proto_icmp.c b/net/ipv4/netfilter/nf_nat_proto_icmp.c
new file mode 100644
index 0000000..19a8b0b
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_icmp.c
@@ -0,0 +1,84 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static bool
+icmp_in_range(const struct nf_conntrack_tuple *tuple,
+	      enum nf_nat_manip_type maniptype,
+	      const union nf_conntrack_man_proto *min,
+	      const union nf_conntrack_man_proto *max)
+{
+	return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) &&
+	       ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
+}
+
+static bool
+icmp_unique_tuple(struct nf_conntrack_tuple *tuple,
+		  const struct nf_nat_range *range,
+		  enum nf_nat_manip_type maniptype,
+		  const struct nf_conn *ct)
+{
+	static u_int16_t id;
+	unsigned int range_size;
+	unsigned int i;
+
+	range_size = ntohs(range->max.icmp.id) - ntohs(range->min.icmp.id) + 1;
+	/* If no range specified... */
+	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED))
+		range_size = 0xFFFF;
+
+	for (i = 0; i < range_size; i++, id++) {
+		tuple->src.u.icmp.id = htons(ntohs(range->min.icmp.id) +
+					     (id % range_size));
+		if (!nf_nat_used_tuple(tuple, ct))
+			return true;
+	}
+	return false;
+}
+
+static bool
+icmp_manip_pkt(struct sk_buff *skb,
+	       unsigned int iphdroff,
+	       const struct nf_conntrack_tuple *tuple,
+	       enum nf_nat_manip_type maniptype)
+{
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	struct icmphdr *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl*4;
+
+	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+		return false;
+
+	hdr = (struct icmphdr *)(skb->data + hdroff);
+	inet_proto_csum_replace2(&hdr->checksum, skb,
+				 hdr->un.echo.id, tuple->src.u.icmp.id, 0);
+	hdr->un.echo.id = tuple->src.u.icmp.id;
+	return true;
+}
+
+const struct nf_nat_protocol nf_nat_protocol_icmp = {
+	.protonum		= IPPROTO_ICMP,
+	.me			= THIS_MODULE,
+	.manip_pkt		= icmp_manip_pkt,
+	.in_range		= icmp_in_range,
+	.unique_tuple		= icmp_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
diff --git a/net/ipv4/netfilter/nf_nat_proto_sctp.c b/net/ipv4/netfilter/nf_nat_proto_sctp.c
new file mode 100644
index 0000000..65e470b
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_sctp.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/sctp.h>
+#include <net/sctp/checksum.h>
+
+#include <net/netfilter/nf_nat_protocol.h>
+
+static u_int16_t nf_sctp_port_rover;
+
+static bool
+sctp_unique_tuple(struct nf_conntrack_tuple *tuple,
+		  const struct nf_nat_range *range,
+		  enum nf_nat_manip_type maniptype,
+		  const struct nf_conn *ct)
+{
+	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+					 &nf_sctp_port_rover);
+}
+
+static bool
+sctp_manip_pkt(struct sk_buff *skb,
+	       unsigned int iphdroff,
+	       const struct nf_conntrack_tuple *tuple,
+	       enum nf_nat_manip_type maniptype)
+{
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	sctp_sctphdr_t *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl*4;
+	__be32 oldip, newip;
+	__be32 crc32;
+
+	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+		return false;
+
+	iph = (struct iphdr *)(skb->data + iphdroff);
+	hdr = (struct sctphdr *)(skb->data + hdroff);
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		/* Get rid of src ip and src pt */
+		oldip = iph->saddr;
+		newip = tuple->src.u3.ip;
+		hdr->source = tuple->src.u.sctp.port;
+	} else {
+		/* Get rid of dst ip and dst pt */
+		oldip = iph->daddr;
+		newip = tuple->dst.u3.ip;
+		hdr->dest = tuple->dst.u.sctp.port;
+	}
+
+	crc32 = sctp_start_cksum((u8 *)hdr, skb_headlen(skb) - hdroff);
+	for (skb = skb_shinfo(skb)->frag_list; skb; skb = skb->next)
+		crc32 = sctp_update_cksum((u8 *)skb->data, skb_headlen(skb),
+					  crc32);
+	crc32 = sctp_end_cksum(crc32);
+	hdr->checksum = crc32;
+
+	return true;
+}
+
+static const struct nf_nat_protocol nf_nat_protocol_sctp = {
+	.protonum		= IPPROTO_SCTP,
+	.me			= THIS_MODULE,
+	.manip_pkt		= sctp_manip_pkt,
+	.in_range		= nf_nat_proto_in_range,
+	.unique_tuple		= sctp_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
+
+static int __init nf_nat_proto_sctp_init(void)
+{
+	return nf_nat_protocol_register(&nf_nat_protocol_sctp);
+}
+
+static void __exit nf_nat_proto_sctp_exit(void)
+{
+	nf_nat_protocol_unregister(&nf_nat_protocol_sctp);
+}
+
+module_init(nf_nat_proto_sctp_init);
+module_exit(nf_nat_proto_sctp_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SCTP NAT protocol helper");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
diff --git a/net/ipv4/netfilter/nf_nat_proto_tcp.c b/net/ipv4/netfilter/nf_nat_proto_tcp.c
new file mode 100644
index 0000000..399e2cf
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_tcp.c
@@ -0,0 +1,93 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+
+static u_int16_t tcp_port_rover;
+
+static bool
+tcp_unique_tuple(struct nf_conntrack_tuple *tuple,
+		 const struct nf_nat_range *range,
+		 enum nf_nat_manip_type maniptype,
+		 const struct nf_conn *ct)
+{
+	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+					 &tcp_port_rover);
+}
+
+static bool
+tcp_manip_pkt(struct sk_buff *skb,
+	      unsigned int iphdroff,
+	      const struct nf_conntrack_tuple *tuple,
+	      enum nf_nat_manip_type maniptype)
+{
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	struct tcphdr *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl*4;
+	__be32 oldip, newip;
+	__be16 *portptr, newport, oldport;
+	int hdrsize = 8; /* TCP connection tracking guarantees this much */
+
+	/* this could be a inner header returned in icmp packet; in such
+	   cases we cannot update the checksum field since it is outside of
+	   the 8 bytes of transport layer headers we are guaranteed */
+	if (skb->len >= hdroff + sizeof(struct tcphdr))
+		hdrsize = sizeof(struct tcphdr);
+
+	if (!skb_make_writable(skb, hdroff + hdrsize))
+		return false;
+
+	iph = (struct iphdr *)(skb->data + iphdroff);
+	hdr = (struct tcphdr *)(skb->data + hdroff);
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		/* Get rid of src ip and src pt */
+		oldip = iph->saddr;
+		newip = tuple->src.u3.ip;
+		newport = tuple->src.u.tcp.port;
+		portptr = &hdr->source;
+	} else {
+		/* Get rid of dst ip and dst pt */
+		oldip = iph->daddr;
+		newip = tuple->dst.u3.ip;
+		newport = tuple->dst.u.tcp.port;
+		portptr = &hdr->dest;
+	}
+
+	oldport = *portptr;
+	*portptr = newport;
+
+	if (hdrsize < sizeof(*hdr))
+		return true;
+
+	inet_proto_csum_replace4(&hdr->check, skb, oldip, newip, 1);
+	inet_proto_csum_replace2(&hdr->check, skb, oldport, newport, 0);
+	return true;
+}
+
+const struct nf_nat_protocol nf_nat_protocol_tcp = {
+	.protonum		= IPPROTO_TCP,
+	.me			= THIS_MODULE,
+	.manip_pkt		= tcp_manip_pkt,
+	.in_range		= nf_nat_proto_in_range,
+	.unique_tuple		= tcp_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
diff --git a/net/ipv4/netfilter/nf_nat_proto_udp.c b/net/ipv4/netfilter/nf_nat_proto_udp.c
new file mode 100644
index 0000000..9e61c79
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_udp.c
@@ -0,0 +1,84 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static u_int16_t udp_port_rover;
+
+static bool
+udp_unique_tuple(struct nf_conntrack_tuple *tuple,
+		 const struct nf_nat_range *range,
+		 enum nf_nat_manip_type maniptype,
+		 const struct nf_conn *ct)
+{
+	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+					 &udp_port_rover);
+}
+
+static bool
+udp_manip_pkt(struct sk_buff *skb,
+	      unsigned int iphdroff,
+	      const struct nf_conntrack_tuple *tuple,
+	      enum nf_nat_manip_type maniptype)
+{
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	struct udphdr *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl*4;
+	__be32 oldip, newip;
+	__be16 *portptr, newport;
+
+	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+		return false;
+
+	iph = (struct iphdr *)(skb->data + iphdroff);
+	hdr = (struct udphdr *)(skb->data + hdroff);
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		/* Get rid of src ip and src pt */
+		oldip = iph->saddr;
+		newip = tuple->src.u3.ip;
+		newport = tuple->src.u.udp.port;
+		portptr = &hdr->source;
+	} else {
+		/* Get rid of dst ip and dst pt */
+		oldip = iph->daddr;
+		newip = tuple->dst.u3.ip;
+		newport = tuple->dst.u.udp.port;
+		portptr = &hdr->dest;
+	}
+	if (hdr->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+		inet_proto_csum_replace4(&hdr->check, skb, oldip, newip, 1);
+		inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport,
+					 0);
+		if (!hdr->check)
+			hdr->check = CSUM_MANGLED_0;
+	}
+	*portptr = newport;
+	return true;
+}
+
+const struct nf_nat_protocol nf_nat_protocol_udp = {
+	.protonum		= IPPROTO_UDP,
+	.me			= THIS_MODULE,
+	.manip_pkt		= udp_manip_pkt,
+	.in_range		= nf_nat_proto_in_range,
+	.unique_tuple		= udp_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
diff --git a/net/ipv4/netfilter/nf_nat_proto_udplite.c b/net/ipv4/netfilter/nf_nat_proto_udplite.c
new file mode 100644
index 0000000..440a229
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_udplite.c
@@ -0,0 +1,99 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static u_int16_t udplite_port_rover;
+
+static bool
+udplite_unique_tuple(struct nf_conntrack_tuple *tuple,
+		     const struct nf_nat_range *range,
+		     enum nf_nat_manip_type maniptype,
+		     const struct nf_conn *ct)
+{
+	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+					 &udplite_port_rover);
+}
+
+static bool
+udplite_manip_pkt(struct sk_buff *skb,
+		  unsigned int iphdroff,
+		  const struct nf_conntrack_tuple *tuple,
+		  enum nf_nat_manip_type maniptype)
+{
+	const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+	struct udphdr *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl*4;
+	__be32 oldip, newip;
+	__be16 *portptr, newport;
+
+	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+		return false;
+
+	iph = (struct iphdr *)(skb->data + iphdroff);
+	hdr = (struct udphdr *)(skb->data + hdroff);
+
+	if (maniptype == IP_NAT_MANIP_SRC) {
+		/* Get rid of src ip and src pt */
+		oldip = iph->saddr;
+		newip = tuple->src.u3.ip;
+		newport = tuple->src.u.udp.port;
+		portptr = &hdr->source;
+	} else {
+		/* Get rid of dst ip and dst pt */
+		oldip = iph->daddr;
+		newip = tuple->dst.u3.ip;
+		newport = tuple->dst.u.udp.port;
+		portptr = &hdr->dest;
+	}
+
+	inet_proto_csum_replace4(&hdr->check, skb, oldip, newip, 1);
+	inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, 0);
+	if (!hdr->check)
+		hdr->check = CSUM_MANGLED_0;
+
+	*portptr = newport;
+	return true;
+}
+
+static const struct nf_nat_protocol nf_nat_protocol_udplite = {
+	.protonum		= IPPROTO_UDPLITE,
+	.me			= THIS_MODULE,
+	.manip_pkt		= udplite_manip_pkt,
+	.in_range		= nf_nat_proto_in_range,
+	.unique_tuple		= udplite_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+	.range_to_nlattr	= nf_nat_proto_range_to_nlattr,
+	.nlattr_to_range	= nf_nat_proto_nlattr_to_range,
+#endif
+};
+
+static int __init nf_nat_proto_udplite_init(void)
+{
+	return nf_nat_protocol_register(&nf_nat_protocol_udplite);
+}
+
+static void __exit nf_nat_proto_udplite_fini(void)
+{
+	nf_nat_protocol_unregister(&nf_nat_protocol_udplite);
+}
+
+module_init(nf_nat_proto_udplite_init);
+module_exit(nf_nat_proto_udplite_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("UDP-Lite NAT protocol helper");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
diff --git a/net/ipv4/netfilter/nf_nat_proto_unknown.c b/net/ipv4/netfilter/nf_nat_proto_unknown.c
new file mode 100644
index 0000000..14381c6
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_unknown.c
@@ -0,0 +1,53 @@
+/* The "unknown" protocol.  This is what is used for protocols we
+ * don't understand.  It's returned by ip_ct_find_proto().
+ */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static bool unknown_in_range(const struct nf_conntrack_tuple *tuple,
+			     enum nf_nat_manip_type manip_type,
+			     const union nf_conntrack_man_proto *min,
+			     const union nf_conntrack_man_proto *max)
+{
+	return true;
+}
+
+static bool unknown_unique_tuple(struct nf_conntrack_tuple *tuple,
+				 const struct nf_nat_range *range,
+				 enum nf_nat_manip_type maniptype,
+				 const struct nf_conn *ct)
+{
+	/* Sorry: we can't help you; if it's not unique, we can't frob
+	   anything. */
+	return false;
+}
+
+static bool
+unknown_manip_pkt(struct sk_buff *skb,
+		  unsigned int iphdroff,
+		  const struct nf_conntrack_tuple *tuple,
+		  enum nf_nat_manip_type maniptype)
+{
+	return true;
+}
+
+const struct nf_nat_protocol nf_nat_unknown_protocol = {
+	/* .me isn't set: getting a ref to this cannot fail. */
+	.manip_pkt		= unknown_manip_pkt,
+	.in_range		= unknown_in_range,
+	.unique_tuple		= unknown_unique_tuple,
+};
diff --git a/net/ipv4/netfilter/nf_nat_rule.c b/net/ipv4/netfilter/nf_nat_rule.c
new file mode 100644
index 0000000..8d489e7
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_rule.c
@@ -0,0 +1,262 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/* Everything about the rules for NAT. */
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <net/checksum.h>
+#include <net/route.h>
+#include <linux/bitops.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_rule.h>
+
+#define NAT_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \
+			 (1 << NF_INET_POST_ROUTING) | \
+			 (1 << NF_INET_LOCAL_OUT))
+
+static struct
+{
+	struct ipt_replace repl;
+	struct ipt_standard entries[3];
+	struct ipt_error term;
+} nat_initial_table __net_initdata = {
+	.repl = {
+		.name = "nat",
+		.valid_hooks = NAT_VALID_HOOKS,
+		.num_entries = 4,
+		.size = sizeof(struct ipt_standard) * 3 + sizeof(struct ipt_error),
+		.hook_entry = {
+			[NF_INET_PRE_ROUTING] = 0,
+			[NF_INET_POST_ROUTING] = sizeof(struct ipt_standard),
+			[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2
+		},
+		.underflow = {
+			[NF_INET_PRE_ROUTING] = 0,
+			[NF_INET_POST_ROUTING] = sizeof(struct ipt_standard),
+			[NF_INET_LOCAL_OUT] = sizeof(struct ipt_standard) * 2
+		},
+	},
+	.entries = {
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* PRE_ROUTING */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* POST_ROUTING */
+		IPT_STANDARD_INIT(NF_ACCEPT),	/* LOCAL_OUT */
+	},
+	.term = IPT_ERROR_INIT,			/* ERROR */
+};
+
+static struct xt_table nat_table = {
+	.name		= "nat",
+	.valid_hooks	= NAT_VALID_HOOKS,
+	.lock		= __RW_LOCK_UNLOCKED(nat_table.lock),
+	.me		= THIS_MODULE,
+	.af		= AF_INET,
+};
+
+/* Source NAT */
+static unsigned int
+ipt_snat_target(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	NF_CT_ASSERT(par->hooknum == NF_INET_POST_ROUTING);
+
+	ct = nf_ct_get(skb, &ctinfo);
+
+	/* Connection must be valid and new. */
+	NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED ||
+			    ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY));
+	NF_CT_ASSERT(par->out != NULL);
+
+	return nf_nat_setup_info(ct, &mr->range[0], IP_NAT_MANIP_SRC);
+}
+
+/* Before 2.6.11 we did implicit source NAT if required. Warn about change. */
+static void warn_if_extra_mangle(struct net *net, __be32 dstip, __be32 srcip)
+{
+	static int warned = 0;
+	struct flowi fl = { .nl_u = { .ip4_u = { .daddr = dstip } } };
+	struct rtable *rt;
+
+	if (ip_route_output_key(net, &rt, &fl) != 0)
+		return;
+
+	if (rt->rt_src != srcip && !warned) {
+		printk("NAT: no longer support implicit source local NAT\n");
+		printk("NAT: packet src %u.%u.%u.%u -> dst %u.%u.%u.%u\n",
+		       NIPQUAD(srcip), NIPQUAD(dstip));
+		warned = 1;
+	}
+	ip_rt_put(rt);
+}
+
+static unsigned int
+ipt_dnat_target(struct sk_buff *skb, const struct xt_target_param *par)
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	NF_CT_ASSERT(par->hooknum == NF_INET_PRE_ROUTING ||
+		     par->hooknum == NF_INET_LOCAL_OUT);
+
+	ct = nf_ct_get(skb, &ctinfo);
+
+	/* Connection must be valid and new. */
+	NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED));
+
+	if (par->hooknum == NF_INET_LOCAL_OUT &&
+	    mr->range[0].flags & IP_NAT_RANGE_MAP_IPS)
+		warn_if_extra_mangle(dev_net(par->out), ip_hdr(skb)->daddr,
+				     mr->range[0].min_ip);
+
+	return nf_nat_setup_info(ct, &mr->range[0], IP_NAT_MANIP_DST);
+}
+
+static bool ipt_snat_checkentry(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	/* Must be a valid range */
+	if (mr->rangesize != 1) {
+		printk("SNAT: multiple ranges no longer supported\n");
+		return false;
+	}
+	return true;
+}
+
+static bool ipt_dnat_checkentry(const struct xt_tgchk_param *par)
+{
+	const struct nf_nat_multi_range_compat *mr = par->targinfo;
+
+	/* Must be a valid range */
+	if (mr->rangesize != 1) {
+		printk("DNAT: multiple ranges no longer supported\n");
+		return false;
+	}
+	return true;
+}
+
+unsigned int
+alloc_null_binding(struct nf_conn *ct, unsigned int hooknum)
+{
+	/* Force range to this IP; let proto decide mapping for
+	   per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED).
+	   Use reply in case it's already been mangled (eg local packet).
+	*/
+	__be32 ip
+		= (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
+		   ? ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip
+		   : ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip);
+	struct nf_nat_range range
+		= { IP_NAT_RANGE_MAP_IPS, ip, ip, { 0 }, { 0 } };
+
+	pr_debug("Allocating NULL binding for %p (%u.%u.%u.%u)\n",
+		 ct, NIPQUAD(ip));
+	return nf_nat_setup_info(ct, &range, HOOK2MANIP(hooknum));
+}
+
+int nf_nat_rule_find(struct sk_buff *skb,
+		     unsigned int hooknum,
+		     const struct net_device *in,
+		     const struct net_device *out,
+		     struct nf_conn *ct)
+{
+	struct net *net = nf_ct_net(ct);
+	int ret;
+
+	ret = ipt_do_table(skb, hooknum, in, out, net->ipv4.nat_table);
+
+	if (ret == NF_ACCEPT) {
+		if (!nf_nat_initialized(ct, HOOK2MANIP(hooknum)))
+			/* NUL mapping */
+			ret = alloc_null_binding(ct, hooknum);
+	}
+	return ret;
+}
+
+static struct xt_target ipt_snat_reg __read_mostly = {
+	.name		= "SNAT",
+	.target		= ipt_snat_target,
+	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.table		= "nat",
+	.hooks		= 1 << NF_INET_POST_ROUTING,
+	.checkentry	= ipt_snat_checkentry,
+	.family		= AF_INET,
+};
+
+static struct xt_target ipt_dnat_reg __read_mostly = {
+	.name		= "DNAT",
+	.target		= ipt_dnat_target,
+	.targetsize	= sizeof(struct nf_nat_multi_range_compat),
+	.table		= "nat",
+	.hooks		= (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT),
+	.checkentry	= ipt_dnat_checkentry,
+	.family		= AF_INET,
+};
+
+static int __net_init nf_nat_rule_net_init(struct net *net)
+{
+	net->ipv4.nat_table = ipt_register_table(net, &nat_table,
+						 &nat_initial_table.repl);
+	if (IS_ERR(net->ipv4.nat_table))
+		return PTR_ERR(net->ipv4.nat_table);
+	return 0;
+}
+
+static void __net_exit nf_nat_rule_net_exit(struct net *net)
+{
+	ipt_unregister_table(net->ipv4.nat_table);
+}
+
+static struct pernet_operations nf_nat_rule_net_ops = {
+	.init = nf_nat_rule_net_init,
+	.exit = nf_nat_rule_net_exit,
+};
+
+int __init nf_nat_rule_init(void)
+{
+	int ret;
+
+	ret = register_pernet_subsys(&nf_nat_rule_net_ops);
+	if (ret != 0)
+		goto out;
+	ret = xt_register_target(&ipt_snat_reg);
+	if (ret != 0)
+		goto unregister_table;
+
+	ret = xt_register_target(&ipt_dnat_reg);
+	if (ret != 0)
+		goto unregister_snat;
+
+	return ret;
+
+ unregister_snat:
+	xt_unregister_target(&ipt_snat_reg);
+ unregister_table:
+	unregister_pernet_subsys(&nf_nat_rule_net_ops);
+ out:
+	return ret;
+}
+
+void nf_nat_rule_cleanup(void)
+{
+	xt_unregister_target(&ipt_dnat_reg);
+	xt_unregister_target(&ipt_snat_reg);
+	unregister_pernet_subsys(&nf_nat_rule_net_ops);
+}
diff --git a/net/ipv4/netfilter/nf_nat_sip.c b/net/ipv4/netfilter/nf_nat_sip.c
new file mode 100644
index 0000000..1454432
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_sip.c
@@ -0,0 +1,502 @@
+/* SIP extension for UDP NAT alteration.
+ *
+ * (C) 2005 by Christian Hentschel <chentschel@arnet.com.ar>
+ * based on RR's ip_nat_ftp.c and other modules.
+ * (C) 2007 United Security Providers
+ * (C) 2007, 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+#include <linux/udp.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_sip.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Christian Hentschel <chentschel@arnet.com.ar>");
+MODULE_DESCRIPTION("SIP NAT helper");
+MODULE_ALIAS("ip_nat_sip");
+
+
+static unsigned int mangle_packet(struct sk_buff *skb,
+				  const char **dptr, unsigned int *datalen,
+				  unsigned int matchoff, unsigned int matchlen,
+				  const char *buffer, unsigned int buflen)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+	if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, matchoff, matchlen,
+				      buffer, buflen))
+		return 0;
+
+	/* Reload data pointer and adjust datalen value */
+	*dptr = skb->data + ip_hdrlen(skb) + sizeof(struct udphdr);
+	*datalen += buflen - matchlen;
+	return 1;
+}
+
+static int map_addr(struct sk_buff *skb,
+		    const char **dptr, unsigned int *datalen,
+		    unsigned int matchoff, unsigned int matchlen,
+		    union nf_inet_addr *addr, __be16 port)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+	unsigned int buflen;
+	__be32 newaddr;
+	__be16 newport;
+
+	if (ct->tuplehash[dir].tuple.src.u3.ip == addr->ip &&
+	    ct->tuplehash[dir].tuple.src.u.udp.port == port) {
+		newaddr = ct->tuplehash[!dir].tuple.dst.u3.ip;
+		newport = ct->tuplehash[!dir].tuple.dst.u.udp.port;
+	} else if (ct->tuplehash[dir].tuple.dst.u3.ip == addr->ip &&
+		   ct->tuplehash[dir].tuple.dst.u.udp.port == port) {
+		newaddr = ct->tuplehash[!dir].tuple.src.u3.ip;
+		newport = ct->tuplehash[!dir].tuple.src.u.udp.port;
+	} else
+		return 1;
+
+	if (newaddr == addr->ip && newport == port)
+		return 1;
+
+	buflen = sprintf(buffer, "%u.%u.%u.%u:%u",
+			 NIPQUAD(newaddr), ntohs(newport));
+
+	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+			     buffer, buflen);
+}
+
+static int map_sip_addr(struct sk_buff *skb,
+			const char **dptr, unsigned int *datalen,
+			enum sip_header_types type)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	unsigned int matchlen, matchoff;
+	union nf_inet_addr addr;
+	__be16 port;
+
+	if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen, type, NULL,
+				    &matchoff, &matchlen, &addr, &port) <= 0)
+		return 1;
+	return map_addr(skb, dptr, datalen, matchoff, matchlen, &addr, port);
+}
+
+static unsigned int ip_nat_sip(struct sk_buff *skb,
+			       const char **dptr, unsigned int *datalen)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	unsigned int dataoff, matchoff, matchlen;
+	union nf_inet_addr addr;
+	__be16 port;
+	int request, in_header;
+
+	/* Basic rules: requests and responses. */
+	if (strnicmp(*dptr, "SIP/2.0", strlen("SIP/2.0")) != 0) {
+		if (ct_sip_parse_request(ct, *dptr, *datalen,
+					 &matchoff, &matchlen,
+					 &addr, &port) > 0 &&
+		    !map_addr(skb, dptr, datalen, matchoff, matchlen,
+			      &addr, port))
+			return NF_DROP;
+		request = 1;
+	} else
+		request = 0;
+
+	/* Translate topmost Via header and parameters */
+	if (ct_sip_parse_header_uri(ct, *dptr, NULL, *datalen,
+				    SIP_HDR_VIA, NULL, &matchoff, &matchlen,
+				    &addr, &port) > 0) {
+		unsigned int matchend, poff, plen, buflen, n;
+		char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+
+		/* We're only interested in headers related to this
+		 * connection */
+		if (request) {
+			if (addr.ip != ct->tuplehash[dir].tuple.src.u3.ip ||
+			    port != ct->tuplehash[dir].tuple.src.u.udp.port)
+				goto next;
+		} else {
+			if (addr.ip != ct->tuplehash[dir].tuple.dst.u3.ip ||
+			    port != ct->tuplehash[dir].tuple.dst.u.udp.port)
+				goto next;
+		}
+
+		if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+			      &addr, port))
+			return NF_DROP;
+
+		matchend = matchoff + matchlen;
+
+		/* The maddr= parameter (RFC 2361) specifies where to send
+		 * the reply. */
+		if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
+					       "maddr=", &poff, &plen,
+					       &addr) > 0 &&
+		    addr.ip == ct->tuplehash[dir].tuple.src.u3.ip &&
+		    addr.ip != ct->tuplehash[!dir].tuple.dst.u3.ip) {
+			__be32 ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+			buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip));
+			if (!mangle_packet(skb, dptr, datalen, poff, plen,
+					   buffer, buflen))
+				return NF_DROP;
+		}
+
+		/* The received= parameter (RFC 2361) contains the address
+		 * from which the server received the request. */
+		if (ct_sip_parse_address_param(ct, *dptr, matchend, *datalen,
+					       "received=", &poff, &plen,
+					       &addr) > 0 &&
+		    addr.ip == ct->tuplehash[dir].tuple.dst.u3.ip &&
+		    addr.ip != ct->tuplehash[!dir].tuple.src.u3.ip) {
+			__be32 ip = ct->tuplehash[!dir].tuple.src.u3.ip;
+			buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(ip));
+			if (!mangle_packet(skb, dptr, datalen, poff, plen,
+					   buffer, buflen))
+				return NF_DROP;
+		}
+
+		/* The rport= parameter (RFC 3581) contains the port number
+		 * from which the server received the request. */
+		if (ct_sip_parse_numerical_param(ct, *dptr, matchend, *datalen,
+						 "rport=", &poff, &plen,
+						 &n) > 0 &&
+		    htons(n) == ct->tuplehash[dir].tuple.dst.u.udp.port &&
+		    htons(n) != ct->tuplehash[!dir].tuple.src.u.udp.port) {
+			__be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port;
+			buflen = sprintf(buffer, "%u", ntohs(p));
+			if (!mangle_packet(skb, dptr, datalen, poff, plen,
+					   buffer, buflen))
+				return NF_DROP;
+		}
+	}
+
+next:
+	/* Translate Contact headers */
+	dataoff = 0;
+	in_header = 0;
+	while (ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen,
+				       SIP_HDR_CONTACT, &in_header,
+				       &matchoff, &matchlen,
+				       &addr, &port) > 0) {
+		if (!map_addr(skb, dptr, datalen, matchoff, matchlen,
+			      &addr, port))
+			return NF_DROP;
+	}
+
+	if (!map_sip_addr(skb, dptr, datalen, SIP_HDR_FROM) ||
+	    !map_sip_addr(skb, dptr, datalen, SIP_HDR_TO))
+		return NF_DROP;
+	return NF_ACCEPT;
+}
+
+/* Handles expected signalling connections and media streams */
+static void ip_nat_sip_expected(struct nf_conn *ct,
+				struct nf_conntrack_expect *exp)
+{
+	struct nf_nat_range range;
+
+	/* This must be a fresh one. */
+	BUG_ON(ct->status & IPS_NAT_DONE_MASK);
+
+	/* For DST manip, map port here to where it's expected. */
+	range.flags = (IP_NAT_RANGE_MAP_IPS | IP_NAT_RANGE_PROTO_SPECIFIED);
+	range.min = range.max = exp->saved_proto;
+	range.min_ip = range.max_ip = exp->saved_ip;
+	nf_nat_setup_info(ct, &range, IP_NAT_MANIP_DST);
+
+	/* Change src to where master sends to, but only if the connection
+	 * actually came from the same source. */
+	if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip ==
+	    ct->master->tuplehash[exp->dir].tuple.src.u3.ip) {
+		range.flags = IP_NAT_RANGE_MAP_IPS;
+		range.min_ip = range.max_ip
+			= ct->master->tuplehash[!exp->dir].tuple.dst.u3.ip;
+		nf_nat_setup_info(ct, &range, IP_NAT_MANIP_SRC);
+	}
+}
+
+static unsigned int ip_nat_sip_expect(struct sk_buff *skb,
+				      const char **dptr, unsigned int *datalen,
+				      struct nf_conntrack_expect *exp,
+				      unsigned int matchoff,
+				      unsigned int matchlen)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	__be32 newip;
+	u_int16_t port;
+	char buffer[sizeof("nnn.nnn.nnn.nnn:nnnnn")];
+	unsigned buflen;
+
+	/* Connection will come from reply */
+	if (ct->tuplehash[dir].tuple.src.u3.ip == ct->tuplehash[!dir].tuple.dst.u3.ip)
+		newip = exp->tuple.dst.u3.ip;
+	else
+		newip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+
+	/* If the signalling port matches the connection's source port in the
+	 * original direction, try to use the destination port in the opposite
+	 * direction. */
+	if (exp->tuple.dst.u.udp.port ==
+	    ct->tuplehash[dir].tuple.src.u.udp.port)
+		port = ntohs(ct->tuplehash[!dir].tuple.dst.u.udp.port);
+	else
+		port = ntohs(exp->tuple.dst.u.udp.port);
+
+	exp->saved_ip = exp->tuple.dst.u3.ip;
+	exp->tuple.dst.u3.ip = newip;
+	exp->saved_proto.udp.port = exp->tuple.dst.u.udp.port;
+	exp->dir = !dir;
+	exp->expectfn = ip_nat_sip_expected;
+
+	for (; port != 0; port++) {
+		exp->tuple.dst.u.udp.port = htons(port);
+		if (nf_ct_expect_related(exp) == 0)
+			break;
+	}
+
+	if (port == 0)
+		return NF_DROP;
+
+	if (exp->tuple.dst.u3.ip != exp->saved_ip ||
+	    exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) {
+		buflen = sprintf(buffer, "%u.%u.%u.%u:%u",
+				 NIPQUAD(newip), port);
+		if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+				   buffer, buflen))
+			goto err;
+	}
+	return NF_ACCEPT;
+
+err:
+	nf_ct_unexpect_related(exp);
+	return NF_DROP;
+}
+
+static int mangle_content_len(struct sk_buff *skb,
+			      const char **dptr, unsigned int *datalen)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	unsigned int matchoff, matchlen;
+	char buffer[sizeof("65536")];
+	int buflen, c_len;
+
+	/* Get actual SDP length */
+	if (ct_sip_get_sdp_header(ct, *dptr, 0, *datalen,
+				  SDP_HDR_VERSION, SDP_HDR_UNSPEC,
+				  &matchoff, &matchlen) <= 0)
+		return 0;
+	c_len = *datalen - matchoff + strlen("v=");
+
+	/* Now, update SDP length */
+	if (ct_sip_get_header(ct, *dptr, 0, *datalen, SIP_HDR_CONTENT_LENGTH,
+			      &matchoff, &matchlen) <= 0)
+		return 0;
+
+	buflen = sprintf(buffer, "%u", c_len);
+	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+			     buffer, buflen);
+}
+
+static int mangle_sdp_packet(struct sk_buff *skb, const char **dptr,
+			     unsigned int dataoff, unsigned int *datalen,
+			     enum sdp_header_types type,
+			     enum sdp_header_types term,
+			     char *buffer, int buflen)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	unsigned int matchlen, matchoff;
+
+	if (ct_sip_get_sdp_header(ct, *dptr, dataoff, *datalen, type, term,
+				  &matchoff, &matchlen) <= 0)
+		return -ENOENT;
+	return mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+			     buffer, buflen) ? 0 : -EINVAL;
+}
+
+static unsigned int ip_nat_sdp_addr(struct sk_buff *skb, const char **dptr,
+				    unsigned int dataoff,
+				    unsigned int *datalen,
+				    enum sdp_header_types type,
+				    enum sdp_header_types term,
+				    const union nf_inet_addr *addr)
+{
+	char buffer[sizeof("nnn.nnn.nnn.nnn")];
+	unsigned int buflen;
+
+	buflen = sprintf(buffer, NIPQUAD_FMT, NIPQUAD(addr->ip));
+	if (mangle_sdp_packet(skb, dptr, dataoff, datalen, type, term,
+			      buffer, buflen))
+		return 0;
+
+	return mangle_content_len(skb, dptr, datalen);
+}
+
+static unsigned int ip_nat_sdp_port(struct sk_buff *skb,
+				    const char **dptr,
+				    unsigned int *datalen,
+				    unsigned int matchoff,
+				    unsigned int matchlen,
+				    u_int16_t port)
+{
+	char buffer[sizeof("nnnnn")];
+	unsigned int buflen;
+
+	buflen = sprintf(buffer, "%u", port);
+	if (!mangle_packet(skb, dptr, datalen, matchoff, matchlen,
+			   buffer, buflen))
+		return 0;
+
+	return mangle_content_len(skb, dptr, datalen);
+}
+
+static unsigned int ip_nat_sdp_session(struct sk_buff *skb, const char **dptr,
+				       unsigned int dataoff,
+				       unsigned int *datalen,
+				       const union nf_inet_addr *addr)
+{
+	char buffer[sizeof("nnn.nnn.nnn.nnn")];
+	unsigned int buflen;
+
+	/* Mangle session description owner and contact addresses */
+	buflen = sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(addr->ip));
+	if (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+			       SDP_HDR_OWNER_IP4, SDP_HDR_MEDIA,
+			       buffer, buflen))
+		return 0;
+
+	switch (mangle_sdp_packet(skb, dptr, dataoff, datalen,
+				  SDP_HDR_CONNECTION_IP4, SDP_HDR_MEDIA,
+				  buffer, buflen)) {
+	case 0:
+	/*
+	 * RFC 2327:
+	 *
+	 * Session description
+	 *
+	 * c=* (connection information - not required if included in all media)
+	 */
+	case -ENOENT:
+		break;
+	default:
+		return 0;
+	}
+
+	return mangle_content_len(skb, dptr, datalen);
+}
+
+/* So, this packet has hit the connection tracking matching code.
+   Mangle it, and change the expectation to match the new version. */
+static unsigned int ip_nat_sdp_media(struct sk_buff *skb,
+				     const char **dptr,
+				     unsigned int *datalen,
+				     struct nf_conntrack_expect *rtp_exp,
+				     struct nf_conntrack_expect *rtcp_exp,
+				     unsigned int mediaoff,
+				     unsigned int medialen,
+				     union nf_inet_addr *rtp_addr)
+{
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	u_int16_t port;
+
+	/* Connection will come from reply */
+	if (ct->tuplehash[dir].tuple.src.u3.ip ==
+	    ct->tuplehash[!dir].tuple.dst.u3.ip)
+		rtp_addr->ip = rtp_exp->tuple.dst.u3.ip;
+	else
+		rtp_addr->ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+
+	rtp_exp->saved_ip = rtp_exp->tuple.dst.u3.ip;
+	rtp_exp->tuple.dst.u3.ip = rtp_addr->ip;
+	rtp_exp->saved_proto.udp.port = rtp_exp->tuple.dst.u.udp.port;
+	rtp_exp->dir = !dir;
+	rtp_exp->expectfn = ip_nat_sip_expected;
+
+	rtcp_exp->saved_ip = rtcp_exp->tuple.dst.u3.ip;
+	rtcp_exp->tuple.dst.u3.ip = rtp_addr->ip;
+	rtcp_exp->saved_proto.udp.port = rtcp_exp->tuple.dst.u.udp.port;
+	rtcp_exp->dir = !dir;
+	rtcp_exp->expectfn = ip_nat_sip_expected;
+
+	/* Try to get same pair of ports: if not, try to change them. */
+	for (port = ntohs(rtp_exp->tuple.dst.u.udp.port);
+	     port != 0; port += 2) {
+		rtp_exp->tuple.dst.u.udp.port = htons(port);
+		if (nf_ct_expect_related(rtp_exp) != 0)
+			continue;
+		rtcp_exp->tuple.dst.u.udp.port = htons(port + 1);
+		if (nf_ct_expect_related(rtcp_exp) == 0)
+			break;
+		nf_ct_unexpect_related(rtp_exp);
+	}
+
+	if (port == 0)
+		goto err1;
+
+	/* Update media port. */
+	if (rtp_exp->tuple.dst.u.udp.port != rtp_exp->saved_proto.udp.port &&
+	    !ip_nat_sdp_port(skb, dptr, datalen, mediaoff, medialen, port))
+		goto err2;
+
+	return NF_ACCEPT;
+
+err2:
+	nf_ct_unexpect_related(rtp_exp);
+	nf_ct_unexpect_related(rtcp_exp);
+err1:
+	return NF_DROP;
+}
+
+static void __exit nf_nat_sip_fini(void)
+{
+	rcu_assign_pointer(nf_nat_sip_hook, NULL);
+	rcu_assign_pointer(nf_nat_sip_expect_hook, NULL);
+	rcu_assign_pointer(nf_nat_sdp_addr_hook, NULL);
+	rcu_assign_pointer(nf_nat_sdp_port_hook, NULL);
+	rcu_assign_pointer(nf_nat_sdp_session_hook, NULL);
+	rcu_assign_pointer(nf_nat_sdp_media_hook, NULL);
+	synchronize_rcu();
+}
+
+static int __init nf_nat_sip_init(void)
+{
+	BUG_ON(nf_nat_sip_hook != NULL);
+	BUG_ON(nf_nat_sip_expect_hook != NULL);
+	BUG_ON(nf_nat_sdp_addr_hook != NULL);
+	BUG_ON(nf_nat_sdp_port_hook != NULL);
+	BUG_ON(nf_nat_sdp_session_hook != NULL);
+	BUG_ON(nf_nat_sdp_media_hook != NULL);
+	rcu_assign_pointer(nf_nat_sip_hook, ip_nat_sip);
+	rcu_assign_pointer(nf_nat_sip_expect_hook, ip_nat_sip_expect);
+	rcu_assign_pointer(nf_nat_sdp_addr_hook, ip_nat_sdp_addr);
+	rcu_assign_pointer(nf_nat_sdp_port_hook, ip_nat_sdp_port);
+	rcu_assign_pointer(nf_nat_sdp_session_hook, ip_nat_sdp_session);
+	rcu_assign_pointer(nf_nat_sdp_media_hook, ip_nat_sdp_media);
+	return 0;
+}
+
+module_init(nf_nat_sip_init);
+module_exit(nf_nat_sip_fini);
diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.c b/net/ipv4/netfilter/nf_nat_snmp_basic.c
new file mode 100644
index 0000000..8303e4b
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_snmp_basic.c
@@ -0,0 +1,1340 @@
+/*
+ * nf_nat_snmp_basic.c
+ *
+ * Basic SNMP Application Layer Gateway
+ *
+ * This IP NAT module is intended for use with SNMP network
+ * discovery and monitoring applications where target networks use
+ * conflicting private address realms.
+ *
+ * Static NAT is used to remap the networks from the view of the network
+ * management system at the IP layer, and this module remaps some application
+ * layer addresses to match.
+ *
+ * The simplest form of ALG is performed, where only tagged IP addresses
+ * are modified.  The module does not need to be MIB aware and only scans
+ * messages at the ASN.1/BER level.
+ *
+ * Currently, only SNMPv1 and SNMPv2 are supported.
+ *
+ * More information on ALG and associated issues can be found in
+ * RFC 2962
+ *
+ * The ASB.1/BER parsing code is derived from the gxsnmp package by Gregory
+ * McLean & Jochen Friedrich, stripped down for use in the kernel.
+ *
+ * Copyright (c) 2000 RP Internet (www.rpi.net.au).
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * Author: James Morris <jmorris@intercode.com.au>
+ */
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_nat_helper.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
+MODULE_DESCRIPTION("Basic SNMP Application Layer Gateway");
+MODULE_ALIAS("ip_nat_snmp_basic");
+
+#define SNMP_PORT 161
+#define SNMP_TRAP_PORT 162
+#define NOCT1(n) (*(u8 *)(n))
+
+static int debug;
+static DEFINE_SPINLOCK(snmp_lock);
+
+/*
+ * Application layer address mapping mimics the NAT mapping, but
+ * only for the first octet in this case (a more flexible system
+ * can be implemented if needed).
+ */
+struct oct1_map
+{
+	u_int8_t from;
+	u_int8_t to;
+};
+
+
+/*****************************************************************************
+ *
+ * Basic ASN.1 decoding routines (gxsnmp author Dirk Wisse)
+ *
+ *****************************************************************************/
+
+/* Class */
+#define ASN1_UNI	0	/* Universal */
+#define ASN1_APL	1	/* Application */
+#define ASN1_CTX	2	/* Context */
+#define ASN1_PRV	3	/* Private */
+
+/* Tag */
+#define ASN1_EOC	0	/* End Of Contents */
+#define ASN1_BOL	1	/* Boolean */
+#define ASN1_INT	2	/* Integer */
+#define ASN1_BTS	3	/* Bit String */
+#define ASN1_OTS	4	/* Octet String */
+#define ASN1_NUL	5	/* Null */
+#define ASN1_OJI	6	/* Object Identifier  */
+#define ASN1_OJD	7	/* Object Description */
+#define ASN1_EXT	8	/* External */
+#define ASN1_SEQ	16	/* Sequence */
+#define ASN1_SET	17	/* Set */
+#define ASN1_NUMSTR	18	/* Numerical String */
+#define ASN1_PRNSTR	19	/* Printable String */
+#define ASN1_TEXSTR	20	/* Teletext String */
+#define ASN1_VIDSTR	21	/* Video String */
+#define ASN1_IA5STR	22	/* IA5 String */
+#define ASN1_UNITIM	23	/* Universal Time */
+#define ASN1_GENTIM	24	/* General Time */
+#define ASN1_GRASTR	25	/* Graphical String */
+#define ASN1_VISSTR	26	/* Visible String */
+#define ASN1_GENSTR	27	/* General String */
+
+/* Primitive / Constructed methods*/
+#define ASN1_PRI	0	/* Primitive */
+#define ASN1_CON	1	/* Constructed */
+
+/*
+ * Error codes.
+ */
+#define ASN1_ERR_NOERROR		0
+#define ASN1_ERR_DEC_EMPTY		2
+#define ASN1_ERR_DEC_EOC_MISMATCH	3
+#define ASN1_ERR_DEC_LENGTH_MISMATCH	4
+#define ASN1_ERR_DEC_BADVALUE		5
+
+/*
+ * ASN.1 context.
+ */
+struct asn1_ctx
+{
+	int error;			/* Error condition */
+	unsigned char *pointer;		/* Octet just to be decoded */
+	unsigned char *begin;		/* First octet */
+	unsigned char *end;		/* Octet after last octet */
+};
+
+/*
+ * Octet string (not null terminated)
+ */
+struct asn1_octstr
+{
+	unsigned char *data;
+	unsigned int len;
+};
+
+static void asn1_open(struct asn1_ctx *ctx,
+		      unsigned char *buf,
+		      unsigned int len)
+{
+	ctx->begin = buf;
+	ctx->end = buf + len;
+	ctx->pointer = buf;
+	ctx->error = ASN1_ERR_NOERROR;
+}
+
+static unsigned char asn1_octet_decode(struct asn1_ctx *ctx, unsigned char *ch)
+{
+	if (ctx->pointer >= ctx->end) {
+		ctx->error = ASN1_ERR_DEC_EMPTY;
+		return 0;
+	}
+	*ch = *(ctx->pointer)++;
+	return 1;
+}
+
+static unsigned char asn1_tag_decode(struct asn1_ctx *ctx, unsigned int *tag)
+{
+	unsigned char ch;
+
+	*tag = 0;
+
+	do
+	{
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+		*tag <<= 7;
+		*tag |= ch & 0x7F;
+	} while ((ch & 0x80) == 0x80);
+	return 1;
+}
+
+static unsigned char asn1_id_decode(struct asn1_ctx *ctx,
+				    unsigned int *cls,
+				    unsigned int *con,
+				    unsigned int *tag)
+{
+	unsigned char ch;
+
+	if (!asn1_octet_decode(ctx, &ch))
+		return 0;
+
+	*cls = (ch & 0xC0) >> 6;
+	*con = (ch & 0x20) >> 5;
+	*tag = (ch & 0x1F);
+
+	if (*tag == 0x1F) {
+		if (!asn1_tag_decode(ctx, tag))
+			return 0;
+	}
+	return 1;
+}
+
+static unsigned char asn1_length_decode(struct asn1_ctx *ctx,
+					unsigned int *def,
+					unsigned int *len)
+{
+	unsigned char ch, cnt;
+
+	if (!asn1_octet_decode(ctx, &ch))
+		return 0;
+
+	if (ch == 0x80)
+		*def = 0;
+	else {
+		*def = 1;
+
+		if (ch < 0x80)
+			*len = ch;
+		else {
+			cnt = ch & 0x7F;
+			*len = 0;
+
+			while (cnt > 0) {
+				if (!asn1_octet_decode(ctx, &ch))
+					return 0;
+				*len <<= 8;
+				*len |= ch;
+				cnt--;
+			}
+		}
+	}
+
+	/* don't trust len bigger than ctx buffer */
+	if (*len > ctx->end - ctx->pointer)
+		return 0;
+
+	return 1;
+}
+
+static unsigned char asn1_header_decode(struct asn1_ctx *ctx,
+					unsigned char **eoc,
+					unsigned int *cls,
+					unsigned int *con,
+					unsigned int *tag)
+{
+	unsigned int def, len;
+
+	if (!asn1_id_decode(ctx, cls, con, tag))
+		return 0;
+
+	def = len = 0;
+	if (!asn1_length_decode(ctx, &def, &len))
+		return 0;
+
+	/* primitive shall be definite, indefinite shall be constructed */
+	if (*con == ASN1_PRI && !def)
+		return 0;
+
+	if (def)
+		*eoc = ctx->pointer + len;
+	else
+		*eoc = NULL;
+	return 1;
+}
+
+static unsigned char asn1_eoc_decode(struct asn1_ctx *ctx, unsigned char *eoc)
+{
+	unsigned char ch;
+
+	if (eoc == NULL) {
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+
+		if (ch != 0x00) {
+			ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
+			return 0;
+		}
+
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+
+		if (ch != 0x00) {
+			ctx->error = ASN1_ERR_DEC_EOC_MISMATCH;
+			return 0;
+		}
+		return 1;
+	} else {
+		if (ctx->pointer != eoc) {
+			ctx->error = ASN1_ERR_DEC_LENGTH_MISMATCH;
+			return 0;
+		}
+		return 1;
+	}
+}
+
+static unsigned char asn1_null_decode(struct asn1_ctx *ctx, unsigned char *eoc)
+{
+	ctx->pointer = eoc;
+	return 1;
+}
+
+static unsigned char asn1_long_decode(struct asn1_ctx *ctx,
+				      unsigned char *eoc,
+				      long *integer)
+{
+	unsigned char ch;
+	unsigned int  len;
+
+	if (!asn1_octet_decode(ctx, &ch))
+		return 0;
+
+	*integer = (signed char) ch;
+	len = 1;
+
+	while (ctx->pointer < eoc) {
+		if (++len > sizeof (long)) {
+			ctx->error = ASN1_ERR_DEC_BADVALUE;
+			return 0;
+		}
+
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+
+		*integer <<= 8;
+		*integer |= ch;
+	}
+	return 1;
+}
+
+static unsigned char asn1_uint_decode(struct asn1_ctx *ctx,
+				      unsigned char *eoc,
+				      unsigned int *integer)
+{
+	unsigned char ch;
+	unsigned int  len;
+
+	if (!asn1_octet_decode(ctx, &ch))
+		return 0;
+
+	*integer = ch;
+	if (ch == 0) len = 0;
+	else len = 1;
+
+	while (ctx->pointer < eoc) {
+		if (++len > sizeof (unsigned int)) {
+			ctx->error = ASN1_ERR_DEC_BADVALUE;
+			return 0;
+		}
+
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+
+		*integer <<= 8;
+		*integer |= ch;
+	}
+	return 1;
+}
+
+static unsigned char asn1_ulong_decode(struct asn1_ctx *ctx,
+				       unsigned char *eoc,
+				       unsigned long *integer)
+{
+	unsigned char ch;
+	unsigned int  len;
+
+	if (!asn1_octet_decode(ctx, &ch))
+		return 0;
+
+	*integer = ch;
+	if (ch == 0) len = 0;
+	else len = 1;
+
+	while (ctx->pointer < eoc) {
+		if (++len > sizeof (unsigned long)) {
+			ctx->error = ASN1_ERR_DEC_BADVALUE;
+			return 0;
+		}
+
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+
+		*integer <<= 8;
+		*integer |= ch;
+	}
+	return 1;
+}
+
+static unsigned char asn1_octets_decode(struct asn1_ctx *ctx,
+					unsigned char *eoc,
+					unsigned char **octets,
+					unsigned int *len)
+{
+	unsigned char *ptr;
+
+	*len = 0;
+
+	*octets = kmalloc(eoc - ctx->pointer, GFP_ATOMIC);
+	if (*octets == NULL) {
+		if (net_ratelimit())
+			printk("OOM in bsalg (%d)\n", __LINE__);
+		return 0;
+	}
+
+	ptr = *octets;
+	while (ctx->pointer < eoc) {
+		if (!asn1_octet_decode(ctx, (unsigned char *)ptr++)) {
+			kfree(*octets);
+			*octets = NULL;
+			return 0;
+		}
+		(*len)++;
+	}
+	return 1;
+}
+
+static unsigned char asn1_subid_decode(struct asn1_ctx *ctx,
+				       unsigned long *subid)
+{
+	unsigned char ch;
+
+	*subid = 0;
+
+	do {
+		if (!asn1_octet_decode(ctx, &ch))
+			return 0;
+
+		*subid <<= 7;
+		*subid |= ch & 0x7F;
+	} while ((ch & 0x80) == 0x80);
+	return 1;
+}
+
+static unsigned char asn1_oid_decode(struct asn1_ctx *ctx,
+				     unsigned char *eoc,
+				     unsigned long **oid,
+				     unsigned int *len)
+{
+	unsigned long subid;
+	unsigned long *optr;
+	size_t size;
+
+	size = eoc - ctx->pointer + 1;
+
+	/* first subid actually encodes first two subids */
+	if (size < 2 || size > ULONG_MAX/sizeof(unsigned long))
+		return 0;
+
+	*oid = kmalloc(size * sizeof(unsigned long), GFP_ATOMIC);
+	if (*oid == NULL) {
+		if (net_ratelimit())
+			printk("OOM in bsalg (%d)\n", __LINE__);
+		return 0;
+	}
+
+	optr = *oid;
+
+	if (!asn1_subid_decode(ctx, &subid)) {
+		kfree(*oid);
+		*oid = NULL;
+		return 0;
+	}
+
+	if (subid < 40) {
+		optr [0] = 0;
+		optr [1] = subid;
+	} else if (subid < 80) {
+		optr [0] = 1;
+		optr [1] = subid - 40;
+	} else {
+		optr [0] = 2;
+		optr [1] = subid - 80;
+	}
+
+	*len = 2;
+	optr += 2;
+
+	while (ctx->pointer < eoc) {
+		if (++(*len) > size) {
+			ctx->error = ASN1_ERR_DEC_BADVALUE;
+			kfree(*oid);
+			*oid = NULL;
+			return 0;
+		}
+
+		if (!asn1_subid_decode(ctx, optr++)) {
+			kfree(*oid);
+			*oid = NULL;
+			return 0;
+		}
+	}
+	return 1;
+}
+
+/*****************************************************************************
+ *
+ * SNMP decoding routines (gxsnmp author Dirk Wisse)
+ *
+ *****************************************************************************/
+
+/* SNMP Versions */
+#define SNMP_V1				0
+#define SNMP_V2C			1
+#define SNMP_V2				2
+#define SNMP_V3				3
+
+/* Default Sizes */
+#define SNMP_SIZE_COMM			256
+#define SNMP_SIZE_OBJECTID		128
+#define SNMP_SIZE_BUFCHR		256
+#define SNMP_SIZE_BUFINT		128
+#define SNMP_SIZE_SMALLOBJECTID		16
+
+/* Requests */
+#define SNMP_PDU_GET			0
+#define SNMP_PDU_NEXT			1
+#define SNMP_PDU_RESPONSE		2
+#define SNMP_PDU_SET			3
+#define SNMP_PDU_TRAP1			4
+#define SNMP_PDU_BULK			5
+#define SNMP_PDU_INFORM			6
+#define SNMP_PDU_TRAP2			7
+
+/* Errors */
+#define SNMP_NOERROR			0
+#define SNMP_TOOBIG			1
+#define SNMP_NOSUCHNAME			2
+#define SNMP_BADVALUE			3
+#define SNMP_READONLY			4
+#define SNMP_GENERROR			5
+#define SNMP_NOACCESS			6
+#define SNMP_WRONGTYPE			7
+#define SNMP_WRONGLENGTH		8
+#define SNMP_WRONGENCODING		9
+#define SNMP_WRONGVALUE			10
+#define SNMP_NOCREATION			11
+#define SNMP_INCONSISTENTVALUE		12
+#define SNMP_RESOURCEUNAVAILABLE	13
+#define SNMP_COMMITFAILED		14
+#define SNMP_UNDOFAILED			15
+#define SNMP_AUTHORIZATIONERROR		16
+#define SNMP_NOTWRITABLE		17
+#define SNMP_INCONSISTENTNAME		18
+
+/* General SNMP V1 Traps */
+#define SNMP_TRAP_COLDSTART		0
+#define SNMP_TRAP_WARMSTART		1
+#define SNMP_TRAP_LINKDOWN		2
+#define SNMP_TRAP_LINKUP		3
+#define SNMP_TRAP_AUTFAILURE		4
+#define SNMP_TRAP_EQPNEIGHBORLOSS	5
+#define SNMP_TRAP_ENTSPECIFIC		6
+
+/* SNMPv1 Types */
+#define SNMP_NULL                0
+#define SNMP_INTEGER             1    /* l  */
+#define SNMP_OCTETSTR            2    /* c  */
+#define SNMP_DISPLAYSTR          2    /* c  */
+#define SNMP_OBJECTID            3    /* ul */
+#define SNMP_IPADDR              4    /* uc */
+#define SNMP_COUNTER             5    /* ul */
+#define SNMP_GAUGE               6    /* ul */
+#define SNMP_TIMETICKS           7    /* ul */
+#define SNMP_OPAQUE              8    /* c  */
+
+/* Additional SNMPv2 Types */
+#define SNMP_UINTEGER            5    /* ul */
+#define SNMP_BITSTR              9    /* uc */
+#define SNMP_NSAP               10    /* uc */
+#define SNMP_COUNTER64          11    /* ul */
+#define SNMP_NOSUCHOBJECT       12
+#define SNMP_NOSUCHINSTANCE     13
+#define SNMP_ENDOFMIBVIEW       14
+
+union snmp_syntax
+{
+	unsigned char uc[0];	/* 8 bit unsigned */
+	char c[0];		/* 8 bit signed */
+	unsigned long ul[0];	/* 32 bit unsigned */
+	long l[0];		/* 32 bit signed */
+};
+
+struct snmp_object
+{
+	unsigned long *id;
+	unsigned int id_len;
+	unsigned short type;
+	unsigned int syntax_len;
+	union snmp_syntax syntax;
+};
+
+struct snmp_request
+{
+	unsigned long id;
+	unsigned int error_status;
+	unsigned int error_index;
+};
+
+struct snmp_v1_trap
+{
+	unsigned long *id;
+	unsigned int id_len;
+	unsigned long ip_address;	/* pointer  */
+	unsigned int general;
+	unsigned int specific;
+	unsigned long time;
+};
+
+/* SNMP types */
+#define SNMP_IPA    0
+#define SNMP_CNT    1
+#define SNMP_GGE    2
+#define SNMP_TIT    3
+#define SNMP_OPQ    4
+#define SNMP_C64    6
+
+/* SNMP errors */
+#define SERR_NSO    0
+#define SERR_NSI    1
+#define SERR_EOM    2
+
+static inline void mangle_address(unsigned char *begin,
+				  unsigned char *addr,
+				  const struct oct1_map *map,
+				  __sum16 *check);
+struct snmp_cnv
+{
+	unsigned int class;
+	unsigned int tag;
+	int syntax;
+};
+
+static const struct snmp_cnv snmp_conv[] = {
+	{ASN1_UNI, ASN1_NUL, SNMP_NULL},
+	{ASN1_UNI, ASN1_INT, SNMP_INTEGER},
+	{ASN1_UNI, ASN1_OTS, SNMP_OCTETSTR},
+	{ASN1_UNI, ASN1_OTS, SNMP_DISPLAYSTR},
+	{ASN1_UNI, ASN1_OJI, SNMP_OBJECTID},
+	{ASN1_APL, SNMP_IPA, SNMP_IPADDR},
+	{ASN1_APL, SNMP_CNT, SNMP_COUNTER},	/* Counter32 */
+	{ASN1_APL, SNMP_GGE, SNMP_GAUGE},	/* Gauge32 == Unsigned32  */
+	{ASN1_APL, SNMP_TIT, SNMP_TIMETICKS},
+	{ASN1_APL, SNMP_OPQ, SNMP_OPAQUE},
+
+	/* SNMPv2 data types and errors */
+	{ASN1_UNI, ASN1_BTS, SNMP_BITSTR},
+	{ASN1_APL, SNMP_C64, SNMP_COUNTER64},
+	{ASN1_CTX, SERR_NSO, SNMP_NOSUCHOBJECT},
+	{ASN1_CTX, SERR_NSI, SNMP_NOSUCHINSTANCE},
+	{ASN1_CTX, SERR_EOM, SNMP_ENDOFMIBVIEW},
+	{0,       0,       -1}
+};
+
+static unsigned char snmp_tag_cls2syntax(unsigned int tag,
+					 unsigned int cls,
+					 unsigned short *syntax)
+{
+	const struct snmp_cnv *cnv;
+
+	cnv = snmp_conv;
+
+	while (cnv->syntax != -1) {
+		if (cnv->tag == tag && cnv->class == cls) {
+			*syntax = cnv->syntax;
+			return 1;
+		}
+		cnv++;
+	}
+	return 0;
+}
+
+static unsigned char snmp_object_decode(struct asn1_ctx *ctx,
+					struct snmp_object **obj)
+{
+	unsigned int cls, con, tag, len, idlen;
+	unsigned short type;
+	unsigned char *eoc, *end, *p;
+	unsigned long *lp, *id;
+	unsigned long ul;
+	long l;
+
+	*obj = NULL;
+	id = NULL;
+
+	if (!asn1_header_decode(ctx, &eoc, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_CON || tag != ASN1_SEQ)
+		return 0;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_OJI)
+		return 0;
+
+	if (!asn1_oid_decode(ctx, end, &id, &idlen))
+		return 0;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag)) {
+		kfree(id);
+		return 0;
+	}
+
+	if (con != ASN1_PRI) {
+		kfree(id);
+		return 0;
+	}
+
+	type = 0;
+	if (!snmp_tag_cls2syntax(tag, cls, &type)) {
+		kfree(id);
+		return 0;
+	}
+
+	l = 0;
+	switch (type) {
+		case SNMP_INTEGER:
+			len = sizeof(long);
+			if (!asn1_long_decode(ctx, end, &l)) {
+				kfree(id);
+				return 0;
+			}
+			*obj = kmalloc(sizeof(struct snmp_object) + len,
+				       GFP_ATOMIC);
+			if (*obj == NULL) {
+				kfree(id);
+				if (net_ratelimit())
+					printk("OOM in bsalg (%d)\n", __LINE__);
+				return 0;
+			}
+			(*obj)->syntax.l[0] = l;
+			break;
+		case SNMP_OCTETSTR:
+		case SNMP_OPAQUE:
+			if (!asn1_octets_decode(ctx, end, &p, &len)) {
+				kfree(id);
+				return 0;
+			}
+			*obj = kmalloc(sizeof(struct snmp_object) + len,
+				       GFP_ATOMIC);
+			if (*obj == NULL) {
+				kfree(p);
+				kfree(id);
+				if (net_ratelimit())
+					printk("OOM in bsalg (%d)\n", __LINE__);
+				return 0;
+			}
+			memcpy((*obj)->syntax.c, p, len);
+			kfree(p);
+			break;
+		case SNMP_NULL:
+		case SNMP_NOSUCHOBJECT:
+		case SNMP_NOSUCHINSTANCE:
+		case SNMP_ENDOFMIBVIEW:
+			len = 0;
+			*obj = kmalloc(sizeof(struct snmp_object), GFP_ATOMIC);
+			if (*obj == NULL) {
+				kfree(id);
+				if (net_ratelimit())
+					printk("OOM in bsalg (%d)\n", __LINE__);
+				return 0;
+			}
+			if (!asn1_null_decode(ctx, end)) {
+				kfree(id);
+				kfree(*obj);
+				*obj = NULL;
+				return 0;
+			}
+			break;
+		case SNMP_OBJECTID:
+			if (!asn1_oid_decode(ctx, end, (unsigned long **)&lp, &len)) {
+				kfree(id);
+				return 0;
+			}
+			len *= sizeof(unsigned long);
+			*obj = kmalloc(sizeof(struct snmp_object) + len, GFP_ATOMIC);
+			if (*obj == NULL) {
+				kfree(lp);
+				kfree(id);
+				if (net_ratelimit())
+					printk("OOM in bsalg (%d)\n", __LINE__);
+				return 0;
+			}
+			memcpy((*obj)->syntax.ul, lp, len);
+			kfree(lp);
+			break;
+		case SNMP_IPADDR:
+			if (!asn1_octets_decode(ctx, end, &p, &len)) {
+				kfree(id);
+				return 0;
+			}
+			if (len != 4) {
+				kfree(p);
+				kfree(id);
+				return 0;
+			}
+			*obj = kmalloc(sizeof(struct snmp_object) + len, GFP_ATOMIC);
+			if (*obj == NULL) {
+				kfree(p);
+				kfree(id);
+				if (net_ratelimit())
+					printk("OOM in bsalg (%d)\n", __LINE__);
+				return 0;
+			}
+			memcpy((*obj)->syntax.uc, p, len);
+			kfree(p);
+			break;
+		case SNMP_COUNTER:
+		case SNMP_GAUGE:
+		case SNMP_TIMETICKS:
+			len = sizeof(unsigned long);
+			if (!asn1_ulong_decode(ctx, end, &ul)) {
+				kfree(id);
+				return 0;
+			}
+			*obj = kmalloc(sizeof(struct snmp_object) + len, GFP_ATOMIC);
+			if (*obj == NULL) {
+				kfree(id);
+				if (net_ratelimit())
+					printk("OOM in bsalg (%d)\n", __LINE__);
+				return 0;
+			}
+			(*obj)->syntax.ul[0] = ul;
+			break;
+		default:
+			kfree(id);
+			return 0;
+	}
+
+	(*obj)->syntax_len = len;
+	(*obj)->type = type;
+	(*obj)->id = id;
+	(*obj)->id_len = idlen;
+
+	if (!asn1_eoc_decode(ctx, eoc)) {
+		kfree(id);
+		kfree(*obj);
+		*obj = NULL;
+		return 0;
+	}
+	return 1;
+}
+
+static unsigned char snmp_request_decode(struct asn1_ctx *ctx,
+					 struct snmp_request *request)
+{
+	unsigned int cls, con, tag;
+	unsigned char *end;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT)
+		return 0;
+
+	if (!asn1_ulong_decode(ctx, end, &request->id))
+		return 0;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT)
+		return 0;
+
+	if (!asn1_uint_decode(ctx, end, &request->error_status))
+		return 0;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT)
+		return 0;
+
+	if (!asn1_uint_decode(ctx, end, &request->error_index))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Fast checksum update for possibly oddly-aligned UDP byte, from the
+ * code example in the draft.
+ */
+static void fast_csum(__sum16 *csum,
+		      const unsigned char *optr,
+		      const unsigned char *nptr,
+		      int offset)
+{
+	unsigned char s[4];
+
+	if (offset & 1) {
+		s[0] = s[2] = 0;
+		s[1] = ~*optr;
+		s[3] = *nptr;
+	} else {
+		s[1] = s[3] = 0;
+		s[0] = ~*optr;
+		s[2] = *nptr;
+	}
+
+	*csum = csum_fold(csum_partial(s, 4, ~csum_unfold(*csum)));
+}
+
+/*
+ * Mangle IP address.
+ * 	- begin points to the start of the snmp messgae
+ *      - addr points to the start of the address
+ */
+static inline void mangle_address(unsigned char *begin,
+				  unsigned char *addr,
+				  const struct oct1_map *map,
+				  __sum16 *check)
+{
+	if (map->from == NOCT1(addr)) {
+		u_int32_t old;
+
+		if (debug)
+			memcpy(&old, addr, sizeof(old));
+
+		*addr = map->to;
+
+		/* Update UDP checksum if being used */
+		if (*check) {
+			fast_csum(check,
+				  &map->from, &map->to, addr - begin);
+
+		}
+
+		if (debug)
+			printk(KERN_DEBUG "bsalg: mapped %u.%u.%u.%u to "
+			       "%u.%u.%u.%u\n", NIPQUAD(old), NIPQUAD(*addr));
+	}
+}
+
+static unsigned char snmp_trap_decode(struct asn1_ctx *ctx,
+				      struct snmp_v1_trap *trap,
+				      const struct oct1_map *map,
+				      __sum16 *check)
+{
+	unsigned int cls, con, tag, len;
+	unsigned char *end;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_OJI)
+		return 0;
+
+	if (!asn1_oid_decode(ctx, end, &trap->id, &trap->id_len))
+		return 0;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		goto err_id_free;
+
+	if (!((cls == ASN1_APL && con == ASN1_PRI && tag == SNMP_IPA) ||
+	      (cls == ASN1_UNI && con == ASN1_PRI && tag == ASN1_OTS)))
+		goto err_id_free;
+
+	if (!asn1_octets_decode(ctx, end, (unsigned char **)&trap->ip_address, &len))
+		goto err_id_free;
+
+	/* IPv4 only */
+	if (len != 4)
+		goto err_addr_free;
+
+	mangle_address(ctx->begin, ctx->pointer - 4, map, check);
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		goto err_addr_free;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT)
+		goto err_addr_free;
+
+	if (!asn1_uint_decode(ctx, end, &trap->general))
+		goto err_addr_free;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		goto err_addr_free;
+
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT)
+		goto err_addr_free;
+
+	if (!asn1_uint_decode(ctx, end, &trap->specific))
+		goto err_addr_free;
+
+	if (!asn1_header_decode(ctx, &end, &cls, &con, &tag))
+		goto err_addr_free;
+
+	if (!((cls == ASN1_APL && con == ASN1_PRI && tag == SNMP_TIT) ||
+	      (cls == ASN1_UNI && con == ASN1_PRI && tag == ASN1_INT)))
+		goto err_addr_free;
+
+	if (!asn1_ulong_decode(ctx, end, &trap->time))
+		goto err_addr_free;
+
+	return 1;
+
+err_addr_free:
+	kfree((unsigned long *)trap->ip_address);
+
+err_id_free:
+	kfree(trap->id);
+
+	return 0;
+}
+
+/*****************************************************************************
+ *
+ * Misc. routines
+ *
+ *****************************************************************************/
+
+static void hex_dump(const unsigned char *buf, size_t len)
+{
+	size_t i;
+
+	for (i = 0; i < len; i++) {
+		if (i && !(i % 16))
+			printk("\n");
+		printk("%02x ", *(buf + i));
+	}
+	printk("\n");
+}
+
+/*
+ * Parse and mangle SNMP message according to mapping.
+ * (And this is the fucking 'basic' method).
+ */
+static int snmp_parse_mangle(unsigned char *msg,
+			     u_int16_t len,
+			     const struct oct1_map *map,
+			     __sum16 *check)
+{
+	unsigned char *eoc, *end;
+	unsigned int cls, con, tag, vers, pdutype;
+	struct asn1_ctx ctx;
+	struct asn1_octstr comm;
+	struct snmp_object **obj;
+
+	if (debug > 1)
+		hex_dump(msg, len);
+
+	asn1_open(&ctx, msg, len);
+
+	/*
+	 * Start of SNMP message.
+	 */
+	if (!asn1_header_decode(&ctx, &eoc, &cls, &con, &tag))
+		return 0;
+	if (cls != ASN1_UNI || con != ASN1_CON || tag != ASN1_SEQ)
+		return 0;
+
+	/*
+	 * Version 1 or 2 handled.
+	 */
+	if (!asn1_header_decode(&ctx, &end, &cls, &con, &tag))
+		return 0;
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT)
+		return 0;
+	if (!asn1_uint_decode (&ctx, end, &vers))
+		return 0;
+	if (debug > 1)
+		printk(KERN_DEBUG "bsalg: snmp version: %u\n", vers + 1);
+	if (vers > 1)
+		return 1;
+
+	/*
+	 * Community.
+	 */
+	if (!asn1_header_decode (&ctx, &end, &cls, &con, &tag))
+		return 0;
+	if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_OTS)
+		return 0;
+	if (!asn1_octets_decode(&ctx, end, &comm.data, &comm.len))
+		return 0;
+	if (debug > 1) {
+		unsigned int i;
+
+		printk(KERN_DEBUG "bsalg: community: ");
+		for (i = 0; i < comm.len; i++)
+			printk("%c", comm.data[i]);
+		printk("\n");
+	}
+	kfree(comm.data);
+
+	/*
+	 * PDU type
+	 */
+	if (!asn1_header_decode(&ctx, &eoc, &cls, &con, &pdutype))
+		return 0;
+	if (cls != ASN1_CTX || con != ASN1_CON)
+		return 0;
+	if (debug > 1) {
+		static const unsigned char *const pdus[] = {
+			[SNMP_PDU_GET] = "get",
+			[SNMP_PDU_NEXT] = "get-next",
+			[SNMP_PDU_RESPONSE] = "response",
+			[SNMP_PDU_SET] = "set",
+			[SNMP_PDU_TRAP1] = "trapv1",
+			[SNMP_PDU_BULK] = "bulk",
+			[SNMP_PDU_INFORM] = "inform",
+			[SNMP_PDU_TRAP2] = "trapv2"
+		};
+
+		if (pdutype > SNMP_PDU_TRAP2)
+			printk(KERN_DEBUG "bsalg: bad pdu type %u\n", pdutype);
+		else
+			printk(KERN_DEBUG "bsalg: pdu: %s\n", pdus[pdutype]);
+	}
+	if (pdutype != SNMP_PDU_RESPONSE &&
+	    pdutype != SNMP_PDU_TRAP1 && pdutype != SNMP_PDU_TRAP2)
+		return 1;
+
+	/*
+	 * Request header or v1 trap
+	 */
+	if (pdutype == SNMP_PDU_TRAP1) {
+		struct snmp_v1_trap trap;
+		unsigned char ret = snmp_trap_decode(&ctx, &trap, map, check);
+
+		if (ret) {
+			kfree(trap.id);
+			kfree((unsigned long *)trap.ip_address);
+		} else
+			return ret;
+
+	} else {
+		struct snmp_request req;
+
+		if (!snmp_request_decode(&ctx, &req))
+			return 0;
+
+		if (debug > 1)
+			printk(KERN_DEBUG "bsalg: request: id=0x%lx error_status=%u "
+			"error_index=%u\n", req.id, req.error_status,
+			req.error_index);
+	}
+
+	/*
+	 * Loop through objects, look for IP addresses to mangle.
+	 */
+	if (!asn1_header_decode(&ctx, &eoc, &cls, &con, &tag))
+		return 0;
+
+	if (cls != ASN1_UNI || con != ASN1_CON || tag != ASN1_SEQ)
+		return 0;
+
+	obj = kmalloc(sizeof(struct snmp_object), GFP_ATOMIC);
+	if (obj == NULL) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "OOM in bsalg(%d)\n", __LINE__);
+		return 0;
+	}
+
+	while (!asn1_eoc_decode(&ctx, eoc)) {
+		unsigned int i;
+
+		if (!snmp_object_decode(&ctx, obj)) {
+			if (*obj) {
+				kfree((*obj)->id);
+				kfree(*obj);
+			}
+			kfree(obj);
+			return 0;
+		}
+
+		if (debug > 1) {
+			printk(KERN_DEBUG "bsalg: object: ");
+			for (i = 0; i < (*obj)->id_len; i++) {
+				if (i > 0)
+					printk(".");
+				printk("%lu", (*obj)->id[i]);
+			}
+			printk(": type=%u\n", (*obj)->type);
+
+		}
+
+		if ((*obj)->type == SNMP_IPADDR)
+			mangle_address(ctx.begin, ctx.pointer - 4 , map, check);
+
+		kfree((*obj)->id);
+		kfree(*obj);
+	}
+	kfree(obj);
+
+	if (!asn1_eoc_decode(&ctx, eoc))
+		return 0;
+
+	return 1;
+}
+
+/*****************************************************************************
+ *
+ * NAT routines.
+ *
+ *****************************************************************************/
+
+/*
+ * SNMP translation routine.
+ */
+static int snmp_translate(struct nf_conn *ct,
+			  enum ip_conntrack_info ctinfo,
+			  struct sk_buff *skb)
+{
+	struct iphdr *iph = ip_hdr(skb);
+	struct udphdr *udph = (struct udphdr *)((__be32 *)iph + iph->ihl);
+	u_int16_t udplen = ntohs(udph->len);
+	u_int16_t paylen = udplen - sizeof(struct udphdr);
+	int dir = CTINFO2DIR(ctinfo);
+	struct oct1_map map;
+
+	/*
+	 * Determine mappping for application layer addresses based
+	 * on NAT manipulations for the packet.
+	 */
+	if (dir == IP_CT_DIR_ORIGINAL) {
+		/* SNAT traps */
+		map.from = NOCT1(&ct->tuplehash[dir].tuple.src.u3.ip);
+		map.to = NOCT1(&ct->tuplehash[!dir].tuple.dst.u3.ip);
+	} else {
+		/* DNAT replies */
+		map.from = NOCT1(&ct->tuplehash[dir].tuple.src.u3.ip);
+		map.to = NOCT1(&ct->tuplehash[!dir].tuple.dst.u3.ip);
+	}
+
+	if (map.from == map.to)
+		return NF_ACCEPT;
+
+	if (!snmp_parse_mangle((unsigned char *)udph + sizeof(struct udphdr),
+			       paylen, &map, &udph->check)) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "bsalg: parser failed\n");
+		return NF_DROP;
+	}
+	return NF_ACCEPT;
+}
+
+/* We don't actually set up expectations, just adjust internal IP
+ * addresses if this is being NATted */
+static int help(struct sk_buff *skb, unsigned int protoff,
+		struct nf_conn *ct,
+		enum ip_conntrack_info ctinfo)
+{
+	int dir = CTINFO2DIR(ctinfo);
+	unsigned int ret;
+	const struct iphdr *iph = ip_hdr(skb);
+	const struct udphdr *udph = (struct udphdr *)((__be32 *)iph + iph->ihl);
+
+	/* SNMP replies and originating SNMP traps get mangled */
+	if (udph->source == htons(SNMP_PORT) && dir != IP_CT_DIR_REPLY)
+		return NF_ACCEPT;
+	if (udph->dest == htons(SNMP_TRAP_PORT) && dir != IP_CT_DIR_ORIGINAL)
+		return NF_ACCEPT;
+
+	/* No NAT? */
+	if (!(ct->status & IPS_NAT_MASK))
+		return NF_ACCEPT;
+
+	/*
+	 * Make sure the packet length is ok.  So far, we were only guaranteed
+	 * to have a valid length IP header plus 8 bytes, which means we have
+	 * enough room for a UDP header.  Just verify the UDP length field so we
+	 * can mess around with the payload.
+	 */
+	if (ntohs(udph->len) != skb->len - (iph->ihl << 2)) {
+		 if (net_ratelimit())
+			 printk(KERN_WARNING "SNMP: dropping malformed packet "
+				"src=%u.%u.%u.%u dst=%u.%u.%u.%u\n",
+				NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+		 return NF_DROP;
+	}
+
+	if (!skb_make_writable(skb, skb->len))
+		return NF_DROP;
+
+	spin_lock_bh(&snmp_lock);
+	ret = snmp_translate(ct, ctinfo, skb);
+	spin_unlock_bh(&snmp_lock);
+	return ret;
+}
+
+static const struct nf_conntrack_expect_policy snmp_exp_policy = {
+	.max_expected	= 0,
+	.timeout	= 180,
+};
+
+static struct nf_conntrack_helper snmp_helper __read_mostly = {
+	.me			= THIS_MODULE,
+	.help			= help,
+	.expect_policy		= &snmp_exp_policy,
+	.name			= "snmp",
+	.tuple.src.l3num	= AF_INET,
+	.tuple.src.u.udp.port	= __constant_htons(SNMP_PORT),
+	.tuple.dst.protonum	= IPPROTO_UDP,
+};
+
+static struct nf_conntrack_helper snmp_trap_helper __read_mostly = {
+	.me			= THIS_MODULE,
+	.help			= help,
+	.expect_policy		= &snmp_exp_policy,
+	.name			= "snmp_trap",
+	.tuple.src.l3num	= AF_INET,
+	.tuple.src.u.udp.port	= __constant_htons(SNMP_TRAP_PORT),
+	.tuple.dst.protonum	= IPPROTO_UDP,
+};
+
+/*****************************************************************************
+ *
+ * Module stuff.
+ *
+ *****************************************************************************/
+
+static int __init nf_nat_snmp_basic_init(void)
+{
+	int ret = 0;
+
+	ret = nf_conntrack_helper_register(&snmp_helper);
+	if (ret < 0)
+		return ret;
+	ret = nf_conntrack_helper_register(&snmp_trap_helper);
+	if (ret < 0) {
+		nf_conntrack_helper_unregister(&snmp_helper);
+		return ret;
+	}
+	return ret;
+}
+
+static void __exit nf_nat_snmp_basic_fini(void)
+{
+	nf_conntrack_helper_unregister(&snmp_helper);
+	nf_conntrack_helper_unregister(&snmp_trap_helper);
+}
+
+module_init(nf_nat_snmp_basic_init);
+module_exit(nf_nat_snmp_basic_fini);
+
+module_param(debug, int, 0600);
diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c
new file mode 100644
index 0000000..b7dd695
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_standalone.c
@@ -0,0 +1,332 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/types.h>
+#include <linux/icmp.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include <linux/spinlock.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_extend.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_nat_protocol.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+
+#ifdef CONFIG_XFRM
+static void nat_decode_session(struct sk_buff *skb, struct flowi *fl)
+{
+	const struct nf_conn *ct;
+	const struct nf_conntrack_tuple *t;
+	enum ip_conntrack_info ctinfo;
+	enum ip_conntrack_dir dir;
+	unsigned long statusbit;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct == NULL)
+		return;
+	dir = CTINFO2DIR(ctinfo);
+	t = &ct->tuplehash[dir].tuple;
+
+	if (dir == IP_CT_DIR_ORIGINAL)
+		statusbit = IPS_DST_NAT;
+	else
+		statusbit = IPS_SRC_NAT;
+
+	if (ct->status & statusbit) {
+		fl->fl4_dst = t->dst.u3.ip;
+		if (t->dst.protonum == IPPROTO_TCP ||
+		    t->dst.protonum == IPPROTO_UDP ||
+		    t->dst.protonum == IPPROTO_UDPLITE ||
+		    t->dst.protonum == IPPROTO_DCCP ||
+		    t->dst.protonum == IPPROTO_SCTP)
+			fl->fl_ip_dport = t->dst.u.tcp.port;
+	}
+
+	statusbit ^= IPS_NAT_MASK;
+
+	if (ct->status & statusbit) {
+		fl->fl4_src = t->src.u3.ip;
+		if (t->dst.protonum == IPPROTO_TCP ||
+		    t->dst.protonum == IPPROTO_UDP ||
+		    t->dst.protonum == IPPROTO_UDPLITE ||
+		    t->dst.protonum == IPPROTO_DCCP ||
+		    t->dst.protonum == IPPROTO_SCTP)
+			fl->fl_ip_sport = t->src.u.tcp.port;
+	}
+}
+#endif
+
+static unsigned int
+nf_nat_fn(unsigned int hooknum,
+	  struct sk_buff *skb,
+	  const struct net_device *in,
+	  const struct net_device *out,
+	  int (*okfn)(struct sk_buff *))
+{
+	struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	struct nf_conn_nat *nat;
+	/* maniptype == SRC for postrouting. */
+	enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum);
+
+	/* We never see fragments: conntrack defrags on pre-routing
+	   and local-out, and nf_nat_out protects post-routing. */
+	NF_CT_ASSERT(!(ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)));
+
+	ct = nf_ct_get(skb, &ctinfo);
+	/* Can't track?  It's not due to stress, or conntrack would
+	   have dropped it.  Hence it's the user's responsibilty to
+	   packet filter it out, or implement conntrack/NAT for that
+	   protocol. 8) --RR */
+	if (!ct)
+		return NF_ACCEPT;
+
+	/* Don't try to NAT if this packet is not conntracked */
+	if (ct == &nf_conntrack_untracked)
+		return NF_ACCEPT;
+
+	nat = nfct_nat(ct);
+	if (!nat) {
+		/* NAT module was loaded late. */
+		if (nf_ct_is_confirmed(ct))
+			return NF_ACCEPT;
+		nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+		if (nat == NULL) {
+			pr_debug("failed to add NAT extension\n");
+			return NF_ACCEPT;
+		}
+	}
+
+	switch (ctinfo) {
+	case IP_CT_RELATED:
+	case IP_CT_RELATED+IP_CT_IS_REPLY:
+		if (ip_hdr(skb)->protocol == IPPROTO_ICMP) {
+			if (!nf_nat_icmp_reply_translation(ct, ctinfo,
+							   hooknum, skb))
+				return NF_DROP;
+			else
+				return NF_ACCEPT;
+		}
+		/* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */
+	case IP_CT_NEW:
+
+		/* Seen it before?  This can happen for loopback, retrans,
+		   or local packets.. */
+		if (!nf_nat_initialized(ct, maniptype)) {
+			unsigned int ret;
+
+			if (hooknum == NF_INET_LOCAL_IN)
+				/* LOCAL_IN hook doesn't have a chain!  */
+				ret = alloc_null_binding(ct, hooknum);
+			else
+				ret = nf_nat_rule_find(skb, hooknum, in, out,
+						       ct);
+
+			if (ret != NF_ACCEPT) {
+				return ret;
+			}
+		} else
+			pr_debug("Already setup manip %s for ct %p\n",
+				 maniptype == IP_NAT_MANIP_SRC ? "SRC" : "DST",
+				 ct);
+		break;
+
+	default:
+		/* ESTABLISHED */
+		NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED ||
+			     ctinfo == (IP_CT_ESTABLISHED+IP_CT_IS_REPLY));
+	}
+
+	return nf_nat_packet(ct, ctinfo, hooknum, skb);
+}
+
+static unsigned int
+nf_nat_in(unsigned int hooknum,
+	  struct sk_buff *skb,
+	  const struct net_device *in,
+	  const struct net_device *out,
+	  int (*okfn)(struct sk_buff *))
+{
+	unsigned int ret;
+	__be32 daddr = ip_hdr(skb)->daddr;
+
+	ret = nf_nat_fn(hooknum, skb, in, out, okfn);
+	if (ret != NF_DROP && ret != NF_STOLEN &&
+	    daddr != ip_hdr(skb)->daddr) {
+		dst_release(skb->dst);
+		skb->dst = NULL;
+	}
+	return ret;
+}
+
+static unsigned int
+nf_nat_out(unsigned int hooknum,
+	   struct sk_buff *skb,
+	   const struct net_device *in,
+	   const struct net_device *out,
+	   int (*okfn)(struct sk_buff *))
+{
+#ifdef CONFIG_XFRM
+	const struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+#endif
+	unsigned int ret;
+
+	/* root is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr) ||
+	    ip_hdrlen(skb) < sizeof(struct iphdr))
+		return NF_ACCEPT;
+
+	ret = nf_nat_fn(hooknum, skb, in, out, okfn);
+#ifdef CONFIG_XFRM
+	if (ret != NF_DROP && ret != NF_STOLEN &&
+	    (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
+		enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+		if (ct->tuplehash[dir].tuple.src.u3.ip !=
+		    ct->tuplehash[!dir].tuple.dst.u3.ip
+		    || ct->tuplehash[dir].tuple.src.u.all !=
+		       ct->tuplehash[!dir].tuple.dst.u.all
+		    )
+			return ip_xfrm_me_harder(skb) == 0 ? ret : NF_DROP;
+	}
+#endif
+	return ret;
+}
+
+static unsigned int
+nf_nat_local_fn(unsigned int hooknum,
+		struct sk_buff *skb,
+		const struct net_device *in,
+		const struct net_device *out,
+		int (*okfn)(struct sk_buff *))
+{
+	const struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	unsigned int ret;
+
+	/* root is playing with raw sockets. */
+	if (skb->len < sizeof(struct iphdr) ||
+	    ip_hdrlen(skb) < sizeof(struct iphdr))
+		return NF_ACCEPT;
+
+	ret = nf_nat_fn(hooknum, skb, in, out, okfn);
+	if (ret != NF_DROP && ret != NF_STOLEN &&
+	    (ct = nf_ct_get(skb, &ctinfo)) != NULL) {
+		enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+
+		if (ct->tuplehash[dir].tuple.dst.u3.ip !=
+		    ct->tuplehash[!dir].tuple.src.u3.ip) {
+			if (ip_route_me_harder(skb, RTN_UNSPEC))
+				ret = NF_DROP;
+		}
+#ifdef CONFIG_XFRM
+		else if (ct->tuplehash[dir].tuple.dst.u.all !=
+			 ct->tuplehash[!dir].tuple.src.u.all)
+			if (ip_xfrm_me_harder(skb))
+				ret = NF_DROP;
+#endif
+	}
+	return ret;
+}
+
+/* We must be after connection tracking and before packet filtering. */
+
+static struct nf_hook_ops nf_nat_ops[] __read_mostly = {
+	/* Before packet filtering, change destination */
+	{
+		.hook		= nf_nat_in,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_PRE_ROUTING,
+		.priority	= NF_IP_PRI_NAT_DST,
+	},
+	/* After packet filtering, change source */
+	{
+		.hook		= nf_nat_out,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_POST_ROUTING,
+		.priority	= NF_IP_PRI_NAT_SRC,
+	},
+	/* Before packet filtering, change destination */
+	{
+		.hook		= nf_nat_local_fn,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_OUT,
+		.priority	= NF_IP_PRI_NAT_DST,
+	},
+	/* After packet filtering, change source */
+	{
+		.hook		= nf_nat_fn,
+		.owner		= THIS_MODULE,
+		.pf		= PF_INET,
+		.hooknum	= NF_INET_LOCAL_IN,
+		.priority	= NF_IP_PRI_NAT_SRC,
+	},
+};
+
+static int __init nf_nat_standalone_init(void)
+{
+	int ret = 0;
+
+	need_ipv4_conntrack();
+
+#ifdef CONFIG_XFRM
+	BUG_ON(ip_nat_decode_session != NULL);
+	rcu_assign_pointer(ip_nat_decode_session, nat_decode_session);
+#endif
+	ret = nf_nat_rule_init();
+	if (ret < 0) {
+		printk("nf_nat_init: can't setup rules.\n");
+		goto cleanup_decode_session;
+	}
+	ret = nf_register_hooks(nf_nat_ops, ARRAY_SIZE(nf_nat_ops));
+	if (ret < 0) {
+		printk("nf_nat_init: can't register hooks.\n");
+		goto cleanup_rule_init;
+	}
+	return ret;
+
+ cleanup_rule_init:
+	nf_nat_rule_cleanup();
+ cleanup_decode_session:
+#ifdef CONFIG_XFRM
+	rcu_assign_pointer(ip_nat_decode_session, NULL);
+	synchronize_net();
+#endif
+	return ret;
+}
+
+static void __exit nf_nat_standalone_fini(void)
+{
+	nf_unregister_hooks(nf_nat_ops, ARRAY_SIZE(nf_nat_ops));
+	nf_nat_rule_cleanup();
+#ifdef CONFIG_XFRM
+	rcu_assign_pointer(ip_nat_decode_session, NULL);
+	synchronize_net();
+#endif
+	/* Conntrack caches are unregistered in nf_conntrack_cleanup */
+}
+
+module_init(nf_nat_standalone_init);
+module_exit(nf_nat_standalone_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat");
diff --git a/net/ipv4/netfilter/nf_nat_tftp.c b/net/ipv4/netfilter/nf_nat_tftp.c
new file mode 100644
index 0000000..b096e81
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_tftp.c
@@ -0,0 +1,52 @@
+/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/udp.h>
+
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_nat_rule.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <linux/netfilter/nf_conntrack_tftp.h>
+
+MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
+MODULE_DESCRIPTION("TFTP NAT helper");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_nat_tftp");
+
+static unsigned int help(struct sk_buff *skb,
+			 enum ip_conntrack_info ctinfo,
+			 struct nf_conntrack_expect *exp)
+{
+	const struct nf_conn *ct = exp->master;
+
+	exp->saved_proto.udp.port
+		= ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u.udp.port;
+	exp->dir = IP_CT_DIR_REPLY;
+	exp->expectfn = nf_nat_follow_master;
+	if (nf_ct_expect_related(exp) != 0)
+		return NF_DROP;
+	return NF_ACCEPT;
+}
+
+static void __exit nf_nat_tftp_fini(void)
+{
+	rcu_assign_pointer(nf_nat_tftp_hook, NULL);
+	synchronize_rcu();
+}
+
+static int __init nf_nat_tftp_init(void)
+{
+	BUG_ON(nf_nat_tftp_hook != NULL);
+	rcu_assign_pointer(nf_nat_tftp_hook, help);
+	return 0;
+}
+
+module_init(nf_nat_tftp_init);
+module_exit(nf_nat_tftp_fini);
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
new file mode 100644
index 0000000..a631a1f
--- /dev/null
+++ b/net/ipv4/proc.c
@@ -0,0 +1,472 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		This file implements the various access functions for the
+ *		PROC file system.  It is mainly used for debugging and
+ *		statistics.
+ *
+ * Authors:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Gerald J. Heim, <heim@peanuts.informatik.uni-tuebingen.de>
+ *		Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de>
+ *		Erik Schoenfelder, <schoenfr@ibr.cs.tu-bs.de>
+ *
+ * Fixes:
+ *		Alan Cox	:	UDP sockets show the rxqueue/txqueue
+ *					using hint flag for the netinfo.
+ *	Pauline Middelink	:	identd support
+ *		Alan Cox	:	Make /proc safer.
+ *	Erik Schoenfelder	:	/proc/net/snmp
+ *		Alan Cox	:	Handle dead sockets properly.
+ *	Gerhard Koerting	:	Show both timers
+ *		Alan Cox	:	Allow inode to be NULL (kernel socket)
+ *	Andi Kleen		:	Add support for open_requests and
+ *					split functions for more readibility.
+ *	Andi Kleen		:	Add support for /proc/net/netstat
+ *	Arnaldo C. Melo		:	Convert to seq_file
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#include <linux/types.h>
+#include <net/net_namespace.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <linux/inetdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <net/sock.h>
+#include <net/raw.h>
+
+/*
+ *	Report socket allocation statistics [mea@utu.fi]
+ */
+static int sockstat_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = seq->private;
+
+	socket_seq_show(seq);
+	seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %d\n",
+		   sock_prot_inuse_get(net, &tcp_prot),
+		   atomic_read(&tcp_orphan_count),
+		   tcp_death_row.tw_count, atomic_read(&tcp_sockets_allocated),
+		   atomic_read(&tcp_memory_allocated));
+	seq_printf(seq, "UDP: inuse %d mem %d\n",
+		   sock_prot_inuse_get(net, &udp_prot),
+		   atomic_read(&udp_memory_allocated));
+	seq_printf(seq, "UDPLITE: inuse %d\n",
+		   sock_prot_inuse_get(net, &udplite_prot));
+	seq_printf(seq, "RAW: inuse %d\n",
+		   sock_prot_inuse_get(net, &raw_prot));
+	seq_printf(seq,  "FRAG: inuse %d memory %d\n",
+			ip_frag_nqueues(net), ip_frag_mem(net));
+	return 0;
+}
+
+static int sockstat_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open_net(inode, file, sockstat_seq_show);
+}
+
+static const struct file_operations sockstat_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = sockstat_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = single_release_net,
+};
+
+/* snmp items */
+static const struct snmp_mib snmp4_ipstats_list[] = {
+	SNMP_MIB_ITEM("InReceives", IPSTATS_MIB_INRECEIVES),
+	SNMP_MIB_ITEM("InHdrErrors", IPSTATS_MIB_INHDRERRORS),
+	SNMP_MIB_ITEM("InAddrErrors", IPSTATS_MIB_INADDRERRORS),
+	SNMP_MIB_ITEM("ForwDatagrams", IPSTATS_MIB_OUTFORWDATAGRAMS),
+	SNMP_MIB_ITEM("InUnknownProtos", IPSTATS_MIB_INUNKNOWNPROTOS),
+	SNMP_MIB_ITEM("InDiscards", IPSTATS_MIB_INDISCARDS),
+	SNMP_MIB_ITEM("InDelivers", IPSTATS_MIB_INDELIVERS),
+	SNMP_MIB_ITEM("OutRequests", IPSTATS_MIB_OUTREQUESTS),
+	SNMP_MIB_ITEM("OutDiscards", IPSTATS_MIB_OUTDISCARDS),
+	SNMP_MIB_ITEM("OutNoRoutes", IPSTATS_MIB_OUTNOROUTES),
+	SNMP_MIB_ITEM("ReasmTimeout", IPSTATS_MIB_REASMTIMEOUT),
+	SNMP_MIB_ITEM("ReasmReqds", IPSTATS_MIB_REASMREQDS),
+	SNMP_MIB_ITEM("ReasmOKs", IPSTATS_MIB_REASMOKS),
+	SNMP_MIB_ITEM("ReasmFails", IPSTATS_MIB_REASMFAILS),
+	SNMP_MIB_ITEM("FragOKs", IPSTATS_MIB_FRAGOKS),
+	SNMP_MIB_ITEM("FragFails", IPSTATS_MIB_FRAGFAILS),
+	SNMP_MIB_ITEM("FragCreates", IPSTATS_MIB_FRAGCREATES),
+	SNMP_MIB_SENTINEL
+};
+
+/* Following RFC4293 items are displayed in /proc/net/netstat */
+static const struct snmp_mib snmp4_ipextstats_list[] = {
+	SNMP_MIB_ITEM("InNoRoutes", IPSTATS_MIB_INNOROUTES),
+	SNMP_MIB_ITEM("InTruncatedPkts", IPSTATS_MIB_INTRUNCATEDPKTS),
+	SNMP_MIB_ITEM("InMcastPkts", IPSTATS_MIB_INMCASTPKTS),
+	SNMP_MIB_ITEM("OutMcastPkts", IPSTATS_MIB_OUTMCASTPKTS),
+	SNMP_MIB_ITEM("InBcastPkts", IPSTATS_MIB_INBCASTPKTS),
+	SNMP_MIB_ITEM("OutBcastPkts", IPSTATS_MIB_OUTBCASTPKTS),
+	SNMP_MIB_SENTINEL
+};
+
+static struct {
+	char *name;
+	int index;
+} icmpmibmap[] = {
+	{ "DestUnreachs", ICMP_DEST_UNREACH },
+	{ "TimeExcds", ICMP_TIME_EXCEEDED },
+	{ "ParmProbs", ICMP_PARAMETERPROB },
+	{ "SrcQuenchs", ICMP_SOURCE_QUENCH },
+	{ "Redirects", ICMP_REDIRECT },
+	{ "Echos", ICMP_ECHO },
+	{ "EchoReps", ICMP_ECHOREPLY },
+	{ "Timestamps", ICMP_TIMESTAMP },
+	{ "TimestampReps", ICMP_TIMESTAMPREPLY },
+	{ "AddrMasks", ICMP_ADDRESS },
+	{ "AddrMaskReps", ICMP_ADDRESSREPLY },
+	{ NULL, 0 }
+};
+
+
+static const struct snmp_mib snmp4_tcp_list[] = {
+	SNMP_MIB_ITEM("RtoAlgorithm", TCP_MIB_RTOALGORITHM),
+	SNMP_MIB_ITEM("RtoMin", TCP_MIB_RTOMIN),
+	SNMP_MIB_ITEM("RtoMax", TCP_MIB_RTOMAX),
+	SNMP_MIB_ITEM("MaxConn", TCP_MIB_MAXCONN),
+	SNMP_MIB_ITEM("ActiveOpens", TCP_MIB_ACTIVEOPENS),
+	SNMP_MIB_ITEM("PassiveOpens", TCP_MIB_PASSIVEOPENS),
+	SNMP_MIB_ITEM("AttemptFails", TCP_MIB_ATTEMPTFAILS),
+	SNMP_MIB_ITEM("EstabResets", TCP_MIB_ESTABRESETS),
+	SNMP_MIB_ITEM("CurrEstab", TCP_MIB_CURRESTAB),
+	SNMP_MIB_ITEM("InSegs", TCP_MIB_INSEGS),
+	SNMP_MIB_ITEM("OutSegs", TCP_MIB_OUTSEGS),
+	SNMP_MIB_ITEM("RetransSegs", TCP_MIB_RETRANSSEGS),
+	SNMP_MIB_ITEM("InErrs", TCP_MIB_INERRS),
+	SNMP_MIB_ITEM("OutRsts", TCP_MIB_OUTRSTS),
+	SNMP_MIB_SENTINEL
+};
+
+static const struct snmp_mib snmp4_udp_list[] = {
+	SNMP_MIB_ITEM("InDatagrams", UDP_MIB_INDATAGRAMS),
+	SNMP_MIB_ITEM("NoPorts", UDP_MIB_NOPORTS),
+	SNMP_MIB_ITEM("InErrors", UDP_MIB_INERRORS),
+	SNMP_MIB_ITEM("OutDatagrams", UDP_MIB_OUTDATAGRAMS),
+	SNMP_MIB_ITEM("RcvbufErrors", UDP_MIB_RCVBUFERRORS),
+	SNMP_MIB_ITEM("SndbufErrors", UDP_MIB_SNDBUFERRORS),
+	SNMP_MIB_SENTINEL
+};
+
+static const struct snmp_mib snmp4_net_list[] = {
+	SNMP_MIB_ITEM("SyncookiesSent", LINUX_MIB_SYNCOOKIESSENT),
+	SNMP_MIB_ITEM("SyncookiesRecv", LINUX_MIB_SYNCOOKIESRECV),
+	SNMP_MIB_ITEM("SyncookiesFailed", LINUX_MIB_SYNCOOKIESFAILED),
+	SNMP_MIB_ITEM("EmbryonicRsts", LINUX_MIB_EMBRYONICRSTS),
+	SNMP_MIB_ITEM("PruneCalled", LINUX_MIB_PRUNECALLED),
+	SNMP_MIB_ITEM("RcvPruned", LINUX_MIB_RCVPRUNED),
+	SNMP_MIB_ITEM("OfoPruned", LINUX_MIB_OFOPRUNED),
+	SNMP_MIB_ITEM("OutOfWindowIcmps", LINUX_MIB_OUTOFWINDOWICMPS),
+	SNMP_MIB_ITEM("LockDroppedIcmps", LINUX_MIB_LOCKDROPPEDICMPS),
+	SNMP_MIB_ITEM("ArpFilter", LINUX_MIB_ARPFILTER),
+	SNMP_MIB_ITEM("TW", LINUX_MIB_TIMEWAITED),
+	SNMP_MIB_ITEM("TWRecycled", LINUX_MIB_TIMEWAITRECYCLED),
+	SNMP_MIB_ITEM("TWKilled", LINUX_MIB_TIMEWAITKILLED),
+	SNMP_MIB_ITEM("PAWSPassive", LINUX_MIB_PAWSPASSIVEREJECTED),
+	SNMP_MIB_ITEM("PAWSActive", LINUX_MIB_PAWSACTIVEREJECTED),
+	SNMP_MIB_ITEM("PAWSEstab", LINUX_MIB_PAWSESTABREJECTED),
+	SNMP_MIB_ITEM("DelayedACKs", LINUX_MIB_DELAYEDACKS),
+	SNMP_MIB_ITEM("DelayedACKLocked", LINUX_MIB_DELAYEDACKLOCKED),
+	SNMP_MIB_ITEM("DelayedACKLost", LINUX_MIB_DELAYEDACKLOST),
+	SNMP_MIB_ITEM("ListenOverflows", LINUX_MIB_LISTENOVERFLOWS),
+	SNMP_MIB_ITEM("ListenDrops", LINUX_MIB_LISTENDROPS),
+	SNMP_MIB_ITEM("TCPPrequeued", LINUX_MIB_TCPPREQUEUED),
+	SNMP_MIB_ITEM("TCPDirectCopyFromBacklog", LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG),
+	SNMP_MIB_ITEM("TCPDirectCopyFromPrequeue", LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE),
+	SNMP_MIB_ITEM("TCPPrequeueDropped", LINUX_MIB_TCPPREQUEUEDROPPED),
+	SNMP_MIB_ITEM("TCPHPHits", LINUX_MIB_TCPHPHITS),
+	SNMP_MIB_ITEM("TCPHPHitsToUser", LINUX_MIB_TCPHPHITSTOUSER),
+	SNMP_MIB_ITEM("TCPPureAcks", LINUX_MIB_TCPPUREACKS),
+	SNMP_MIB_ITEM("TCPHPAcks", LINUX_MIB_TCPHPACKS),
+	SNMP_MIB_ITEM("TCPRenoRecovery", LINUX_MIB_TCPRENORECOVERY),
+	SNMP_MIB_ITEM("TCPSackRecovery", LINUX_MIB_TCPSACKRECOVERY),
+	SNMP_MIB_ITEM("TCPSACKReneging", LINUX_MIB_TCPSACKRENEGING),
+	SNMP_MIB_ITEM("TCPFACKReorder", LINUX_MIB_TCPFACKREORDER),
+	SNMP_MIB_ITEM("TCPSACKReorder", LINUX_MIB_TCPSACKREORDER),
+	SNMP_MIB_ITEM("TCPRenoReorder", LINUX_MIB_TCPRENOREORDER),
+	SNMP_MIB_ITEM("TCPTSReorder", LINUX_MIB_TCPTSREORDER),
+	SNMP_MIB_ITEM("TCPFullUndo", LINUX_MIB_TCPFULLUNDO),
+	SNMP_MIB_ITEM("TCPPartialUndo", LINUX_MIB_TCPPARTIALUNDO),
+	SNMP_MIB_ITEM("TCPDSACKUndo", LINUX_MIB_TCPDSACKUNDO),
+	SNMP_MIB_ITEM("TCPLossUndo", LINUX_MIB_TCPLOSSUNDO),
+	SNMP_MIB_ITEM("TCPLoss", LINUX_MIB_TCPLOSS),
+	SNMP_MIB_ITEM("TCPLostRetransmit", LINUX_MIB_TCPLOSTRETRANSMIT),
+	SNMP_MIB_ITEM("TCPRenoFailures", LINUX_MIB_TCPRENOFAILURES),
+	SNMP_MIB_ITEM("TCPSackFailures", LINUX_MIB_TCPSACKFAILURES),
+	SNMP_MIB_ITEM("TCPLossFailures", LINUX_MIB_TCPLOSSFAILURES),
+	SNMP_MIB_ITEM("TCPFastRetrans", LINUX_MIB_TCPFASTRETRANS),
+	SNMP_MIB_ITEM("TCPForwardRetrans", LINUX_MIB_TCPFORWARDRETRANS),
+	SNMP_MIB_ITEM("TCPSlowStartRetrans", LINUX_MIB_TCPSLOWSTARTRETRANS),
+	SNMP_MIB_ITEM("TCPTimeouts", LINUX_MIB_TCPTIMEOUTS),
+	SNMP_MIB_ITEM("TCPRenoRecoveryFail", LINUX_MIB_TCPRENORECOVERYFAIL),
+	SNMP_MIB_ITEM("TCPSackRecoveryFail", LINUX_MIB_TCPSACKRECOVERYFAIL),
+	SNMP_MIB_ITEM("TCPSchedulerFailed", LINUX_MIB_TCPSCHEDULERFAILED),
+	SNMP_MIB_ITEM("TCPRcvCollapsed", LINUX_MIB_TCPRCVCOLLAPSED),
+	SNMP_MIB_ITEM("TCPDSACKOldSent", LINUX_MIB_TCPDSACKOLDSENT),
+	SNMP_MIB_ITEM("TCPDSACKOfoSent", LINUX_MIB_TCPDSACKOFOSENT),
+	SNMP_MIB_ITEM("TCPDSACKRecv", LINUX_MIB_TCPDSACKRECV),
+	SNMP_MIB_ITEM("TCPDSACKOfoRecv", LINUX_MIB_TCPDSACKOFORECV),
+	SNMP_MIB_ITEM("TCPAbortOnSyn", LINUX_MIB_TCPABORTONSYN),
+	SNMP_MIB_ITEM("TCPAbortOnData", LINUX_MIB_TCPABORTONDATA),
+	SNMP_MIB_ITEM("TCPAbortOnClose", LINUX_MIB_TCPABORTONCLOSE),
+	SNMP_MIB_ITEM("TCPAbortOnMemory", LINUX_MIB_TCPABORTONMEMORY),
+	SNMP_MIB_ITEM("TCPAbortOnTimeout", LINUX_MIB_TCPABORTONTIMEOUT),
+	SNMP_MIB_ITEM("TCPAbortOnLinger", LINUX_MIB_TCPABORTONLINGER),
+	SNMP_MIB_ITEM("TCPAbortFailed", LINUX_MIB_TCPABORTFAILED),
+	SNMP_MIB_ITEM("TCPMemoryPressures", LINUX_MIB_TCPMEMORYPRESSURES),
+	SNMP_MIB_ITEM("TCPSACKDiscard", LINUX_MIB_TCPSACKDISCARD),
+	SNMP_MIB_ITEM("TCPDSACKIgnoredOld", LINUX_MIB_TCPDSACKIGNOREDOLD),
+	SNMP_MIB_ITEM("TCPDSACKIgnoredNoUndo", LINUX_MIB_TCPDSACKIGNOREDNOUNDO),
+	SNMP_MIB_ITEM("TCPSpuriousRTOs", LINUX_MIB_TCPSPURIOUSRTOS),
+	SNMP_MIB_ITEM("TCPMD5NotFound", LINUX_MIB_TCPMD5NOTFOUND),
+	SNMP_MIB_ITEM("TCPMD5Unexpected", LINUX_MIB_TCPMD5UNEXPECTED),
+	SNMP_MIB_SENTINEL
+};
+
+static void icmpmsg_put_line(struct seq_file *seq, unsigned long *vals,
+			     unsigned short *type, int count)
+{
+	int j;
+
+	if (count) {
+		seq_printf(seq, "\nIcmpMsg:");
+		for (j = 0; j < count; ++j)
+			seq_printf(seq, " %sType%u",
+				type[j] & 0x100 ? "Out" : "In",
+				type[j] & 0xff);
+		seq_printf(seq, "\nIcmpMsg:");
+		for (j = 0; j < count; ++j)
+			seq_printf(seq, " %lu", vals[j]);
+	}
+}
+
+static void icmpmsg_put(struct seq_file *seq)
+{
+#define PERLINE	16
+
+	int i, count;
+	unsigned short type[PERLINE];
+	unsigned long vals[PERLINE], val;
+	struct net *net = seq->private;
+
+	count = 0;
+	for (i = 0; i < ICMPMSG_MIB_MAX; i++) {
+		val = snmp_fold_field((void **) net->mib.icmpmsg_statistics, i);
+		if (val) {
+			type[count] = i;
+			vals[count++] = val;
+		}
+		if (count == PERLINE) {
+			icmpmsg_put_line(seq, vals, type, count);
+			count = 0;
+		}
+	}
+	icmpmsg_put_line(seq, vals, type, count);
+
+#undef PERLINE
+}
+
+static void icmp_put(struct seq_file *seq)
+{
+	int i;
+	struct net *net = seq->private;
+
+	seq_puts(seq, "\nIcmp: InMsgs InErrors");
+	for (i=0; icmpmibmap[i].name != NULL; i++)
+		seq_printf(seq, " In%s", icmpmibmap[i].name);
+	seq_printf(seq, " OutMsgs OutErrors");
+	for (i=0; icmpmibmap[i].name != NULL; i++)
+		seq_printf(seq, " Out%s", icmpmibmap[i].name);
+	seq_printf(seq, "\nIcmp: %lu %lu",
+		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_INMSGS),
+		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_INERRORS));
+	for (i=0; icmpmibmap[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			snmp_fold_field((void **) net->mib.icmpmsg_statistics,
+				icmpmibmap[i].index));
+	seq_printf(seq, " %lu %lu",
+		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_OUTMSGS),
+		snmp_fold_field((void **) net->mib.icmp_statistics, ICMP_MIB_OUTERRORS));
+	for (i=0; icmpmibmap[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			snmp_fold_field((void **) net->mib.icmpmsg_statistics,
+				icmpmibmap[i].index | 0x100));
+}
+
+/*
+ *	Called from the PROCfs module. This outputs /proc/net/snmp.
+ */
+static int snmp_seq_show(struct seq_file *seq, void *v)
+{
+	int i;
+	struct net *net = seq->private;
+
+	seq_puts(seq, "Ip: Forwarding DefaultTTL");
+
+	for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_ipstats_list[i].name);
+
+	seq_printf(seq, "\nIp: %d %d",
+		   IPV4_DEVCONF_ALL(net, FORWARDING) ? 1 : 2,
+		   sysctl_ip_default_ttl);
+
+	for (i = 0; snmp4_ipstats_list[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			   snmp_fold_field((void **)net->mib.ip_statistics,
+					   snmp4_ipstats_list[i].entry));
+
+	icmp_put(seq);	/* RFC 2011 compatibility */
+	icmpmsg_put(seq);
+
+	seq_puts(seq, "\nTcp:");
+	for (i = 0; snmp4_tcp_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_tcp_list[i].name);
+
+	seq_puts(seq, "\nTcp:");
+	for (i = 0; snmp4_tcp_list[i].name != NULL; i++) {
+		/* MaxConn field is signed, RFC 2012 */
+		if (snmp4_tcp_list[i].entry == TCP_MIB_MAXCONN)
+			seq_printf(seq, " %ld",
+				   snmp_fold_field((void **)net->mib.tcp_statistics,
+						   snmp4_tcp_list[i].entry));
+		else
+			seq_printf(seq, " %lu",
+				   snmp_fold_field((void **)net->mib.tcp_statistics,
+						   snmp4_tcp_list[i].entry));
+	}
+
+	seq_puts(seq, "\nUdp:");
+	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_udp_list[i].name);
+
+	seq_puts(seq, "\nUdp:");
+	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			   snmp_fold_field((void **)net->mib.udp_statistics,
+					   snmp4_udp_list[i].entry));
+
+	/* the UDP and UDP-Lite MIBs are the same */
+	seq_puts(seq, "\nUdpLite:");
+	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_udp_list[i].name);
+
+	seq_puts(seq, "\nUdpLite:");
+	for (i = 0; snmp4_udp_list[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			   snmp_fold_field((void **)net->mib.udplite_statistics,
+					   snmp4_udp_list[i].entry));
+
+	seq_putc(seq, '\n');
+	return 0;
+}
+
+static int snmp_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open_net(inode, file, snmp_seq_show);
+}
+
+static const struct file_operations snmp_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = snmp_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = single_release_net,
+};
+
+
+
+/*
+ *	Output /proc/net/netstat
+ */
+static int netstat_seq_show(struct seq_file *seq, void *v)
+{
+	int i;
+	struct net *net = seq->private;
+
+	seq_puts(seq, "TcpExt:");
+	for (i = 0; snmp4_net_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_net_list[i].name);
+
+	seq_puts(seq, "\nTcpExt:");
+	for (i = 0; snmp4_net_list[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			   snmp_fold_field((void **)net->mib.net_statistics,
+					   snmp4_net_list[i].entry));
+
+	seq_puts(seq, "\nIpExt:");
+	for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++)
+		seq_printf(seq, " %s", snmp4_ipextstats_list[i].name);
+
+	seq_puts(seq, "\nIpExt:");
+	for (i = 0; snmp4_ipextstats_list[i].name != NULL; i++)
+		seq_printf(seq, " %lu",
+			   snmp_fold_field((void **)net->mib.ip_statistics,
+					   snmp4_ipextstats_list[i].entry));
+
+	seq_putc(seq, '\n');
+	return 0;
+}
+
+static int netstat_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open_net(inode, file, netstat_seq_show);
+}
+
+static const struct file_operations netstat_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = netstat_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = single_release_net,
+};
+
+static __net_init int ip_proc_init_net(struct net *net)
+{
+	if (!proc_net_fops_create(net, "sockstat", S_IRUGO, &sockstat_seq_fops))
+		goto out_sockstat;
+	if (!proc_net_fops_create(net, "netstat", S_IRUGO, &netstat_seq_fops))
+		goto out_netstat;
+	if (!proc_net_fops_create(net, "snmp", S_IRUGO, &snmp_seq_fops))
+		goto out_snmp;
+
+	return 0;
+
+out_snmp:
+	proc_net_remove(net, "netstat");
+out_netstat:
+	proc_net_remove(net, "sockstat");
+out_sockstat:
+	return -ENOMEM;
+}
+
+static __net_exit void ip_proc_exit_net(struct net *net)
+{
+	proc_net_remove(net, "snmp");
+	proc_net_remove(net, "netstat");
+	proc_net_remove(net, "sockstat");
+}
+
+static __net_initdata struct pernet_operations ip_proc_ops = {
+	.init = ip_proc_init_net,
+	.exit = ip_proc_exit_net,
+};
+
+int __init ip_misc_proc_init(void)
+{
+	return register_pernet_subsys(&ip_proc_ops);
+}
+
diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
new file mode 100644
index 0000000..ea50da0
--- /dev/null
+++ b/net/ipv4/protocol.c
@@ -0,0 +1,96 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		INET protocol dispatch tables.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ * Fixes:
+ *		Alan Cox	: Ahah! udp icmp errors don't work because
+ *				  udp_err is never called!
+ *		Alan Cox	: Added new fields for init and ready for
+ *				  proper fragmentation (_NO_ 4K limits!)
+ *		Richard Colella	: Hang on hash collision
+ *		Vince Laviano	: Modified inet_del_protocol() to correctly
+ *				  maintain copy bit.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/timer.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/ipip.h>
+#include <linux/igmp.h>
+
+struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp;
+static DEFINE_SPINLOCK(inet_proto_lock);
+
+/*
+ *	Add a protocol handler to the hash tables
+ */
+
+int inet_add_protocol(struct net_protocol *prot, unsigned char protocol)
+{
+	int hash, ret;
+
+	hash = protocol & (MAX_INET_PROTOS - 1);
+
+	spin_lock_bh(&inet_proto_lock);
+	if (inet_protos[hash]) {
+		ret = -1;
+	} else {
+		inet_protos[hash] = prot;
+		ret = 0;
+	}
+	spin_unlock_bh(&inet_proto_lock);
+
+	return ret;
+}
+
+/*
+ *	Remove a protocol from the hash tables.
+ */
+
+int inet_del_protocol(struct net_protocol *prot, unsigned char protocol)
+{
+	int hash, ret;
+
+	hash = protocol & (MAX_INET_PROTOS - 1);
+
+	spin_lock_bh(&inet_proto_lock);
+	if (inet_protos[hash] == prot) {
+		inet_protos[hash] = NULL;
+		ret = 0;
+	} else {
+		ret = -1;
+	}
+	spin_unlock_bh(&inet_proto_lock);
+
+	synchronize_net();
+
+	return ret;
+}
+
+EXPORT_SYMBOL(inet_add_protocol);
+EXPORT_SYMBOL(inet_del_protocol);
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
new file mode 100644
index 0000000..cd97574
--- /dev/null
+++ b/net/ipv4/raw.c
@@ -0,0 +1,1017 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		RAW - implementation of IP "raw" sockets.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ * Fixes:
+ *		Alan Cox	:	verify_area() fixed up
+ *		Alan Cox	:	ICMP error handling
+ *		Alan Cox	:	EMSGSIZE if you send too big a packet
+ *		Alan Cox	: 	Now uses generic datagrams and shared
+ *					skbuff library. No more peek crashes,
+ *					no more backlogs
+ *		Alan Cox	:	Checks sk->broadcast.
+ *		Alan Cox	:	Uses skb_free_datagram/skb_copy_datagram
+ *		Alan Cox	:	Raw passes ip options too
+ *		Alan Cox	:	Setsocketopt added
+ *		Alan Cox	:	Fixed error return for broadcasts
+ *		Alan Cox	:	Removed wake_up calls
+ *		Alan Cox	:	Use ttl/tos
+ *		Alan Cox	:	Cleaned up old debugging
+ *		Alan Cox	:	Use new kernel side addresses
+ *	Arnt Gulbrandsen	:	Fixed MSG_DONTROUTE in raw sockets.
+ *		Alan Cox	:	BSD style RAW socket demultiplexing.
+ *		Alan Cox	:	Beginnings of mrouted support.
+ *		Alan Cox	:	Added IP_HDRINCL option.
+ *		Alan Cox	:	Skip broadcast check if BSDism set.
+ *		David S. Miller	:	New socket lookup architecture.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <asm/atomic.h>
+#include <asm/byteorder.h>
+#include <asm/current.h>
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+#include <linux/stddef.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/aio.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/sockios.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/mroute.h>
+#include <linux/netdevice.h>
+#include <linux/in_route.h>
+#include <linux/route.h>
+#include <linux/skbuff.h>
+#include <net/net_namespace.h>
+#include <net/dst.h>
+#include <net/sock.h>
+#include <linux/gfp.h>
+#include <linux/ip.h>
+#include <linux/net.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/raw.h>
+#include <net/snmp.h>
+#include <net/tcp_states.h>
+#include <net/inet_common.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+#include <linux/rtnetlink.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+
+static struct raw_hashinfo raw_v4_hashinfo = {
+	.lock = __RW_LOCK_UNLOCKED(raw_v4_hashinfo.lock),
+};
+
+void raw_hash_sk(struct sock *sk)
+{
+	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;
+	struct hlist_head *head;
+
+	head = &h->ht[inet_sk(sk)->num & (RAW_HTABLE_SIZE - 1)];
+
+	write_lock_bh(&h->lock);
+	sk_add_node(sk, head);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	write_unlock_bh(&h->lock);
+}
+EXPORT_SYMBOL_GPL(raw_hash_sk);
+
+void raw_unhash_sk(struct sock *sk)
+{
+	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;
+
+	write_lock_bh(&h->lock);
+	if (sk_del_node_init(sk))
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+	write_unlock_bh(&h->lock);
+}
+EXPORT_SYMBOL_GPL(raw_unhash_sk);
+
+static struct sock *__raw_v4_lookup(struct net *net, struct sock *sk,
+		unsigned short num, __be32 raddr, __be32 laddr, int dif)
+{
+	struct hlist_node *node;
+
+	sk_for_each_from(sk, node) {
+		struct inet_sock *inet = inet_sk(sk);
+
+		if (net_eq(sock_net(sk), net) && inet->num == num	&&
+		    !(inet->daddr && inet->daddr != raddr) 		&&
+		    !(inet->rcv_saddr && inet->rcv_saddr != laddr)	&&
+		    !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
+			goto found; /* gotcha */
+	}
+	sk = NULL;
+found:
+	return sk;
+}
+
+/*
+ *	0 - deliver
+ *	1 - block
+ */
+static __inline__ int icmp_filter(struct sock *sk, struct sk_buff *skb)
+{
+	int type;
+
+	if (!pskb_may_pull(skb, sizeof(struct icmphdr)))
+		return 1;
+
+	type = icmp_hdr(skb)->type;
+	if (type < 32) {
+		__u32 data = raw_sk(sk)->filter.data;
+
+		return ((1 << type) & data) != 0;
+	}
+
+	/* Do not block unknown ICMP types */
+	return 0;
+}
+
+/* IP input processing comes here for RAW socket delivery.
+ * Caller owns SKB, so we must make clones.
+ *
+ * RFC 1122: SHOULD pass TOS value up to the transport layer.
+ * -> It does. And not only TOS, but all IP header.
+ */
+static int raw_v4_input(struct sk_buff *skb, struct iphdr *iph, int hash)
+{
+	struct sock *sk;
+	struct hlist_head *head;
+	int delivered = 0;
+	struct net *net;
+
+	read_lock(&raw_v4_hashinfo.lock);
+	head = &raw_v4_hashinfo.ht[hash];
+	if (hlist_empty(head))
+		goto out;
+
+	net = dev_net(skb->dev);
+	sk = __raw_v4_lookup(net, __sk_head(head), iph->protocol,
+			     iph->saddr, iph->daddr,
+			     skb->dev->ifindex);
+
+	while (sk) {
+		delivered = 1;
+		if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
+			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
+
+			/* Not releasing hash table! */
+			if (clone)
+				raw_rcv(sk, clone);
+		}
+		sk = __raw_v4_lookup(net, sk_next(sk), iph->protocol,
+				     iph->saddr, iph->daddr,
+				     skb->dev->ifindex);
+	}
+out:
+	read_unlock(&raw_v4_hashinfo.lock);
+	return delivered;
+}
+
+int raw_local_deliver(struct sk_buff *skb, int protocol)
+{
+	int hash;
+	struct sock *raw_sk;
+
+	hash = protocol & (RAW_HTABLE_SIZE - 1);
+	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);
+
+	/* If there maybe a raw socket we must check - if not we
+	 * don't care less
+	 */
+	if (raw_sk && !raw_v4_input(skb, ip_hdr(skb), hash))
+		raw_sk = NULL;
+
+	return raw_sk != NULL;
+
+}
+
+static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	const int type = icmp_hdr(skb)->type;
+	const int code = icmp_hdr(skb)->code;
+	int err = 0;
+	int harderr = 0;
+
+	/* Report error on raw socket, if:
+	   1. User requested ip_recverr.
+	   2. Socket is connected (otherwise the error indication
+	      is useless without ip_recverr and error is hard.
+	 */
+	if (!inet->recverr && sk->sk_state != TCP_ESTABLISHED)
+		return;
+
+	switch (type) {
+	default:
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	case ICMP_SOURCE_QUENCH:
+		return;
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		harderr = 1;
+		break;
+	case ICMP_DEST_UNREACH:
+		err = EHOSTUNREACH;
+		if (code > NR_ICMP_UNREACH)
+			break;
+		err = icmp_err_convert[code].errno;
+		harderr = icmp_err_convert[code].fatal;
+		if (code == ICMP_FRAG_NEEDED) {
+			harderr = inet->pmtudisc != IP_PMTUDISC_DONT;
+			err = EMSGSIZE;
+		}
+	}
+
+	if (inet->recverr) {
+		struct iphdr *iph = (struct iphdr*)skb->data;
+		u8 *payload = skb->data + (iph->ihl << 2);
+
+		if (inet->hdrincl)
+			payload = skb->data;
+		ip_icmp_error(sk, skb, err, 0, info, payload);
+	}
+
+	if (inet->recverr || harderr) {
+		sk->sk_err = err;
+		sk->sk_error_report(sk);
+	}
+}
+
+void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
+{
+	int hash;
+	struct sock *raw_sk;
+	struct iphdr *iph;
+	struct net *net;
+
+	hash = protocol & (RAW_HTABLE_SIZE - 1);
+
+	read_lock(&raw_v4_hashinfo.lock);
+	raw_sk = sk_head(&raw_v4_hashinfo.ht[hash]);
+	if (raw_sk != NULL) {
+		iph = (struct iphdr *)skb->data;
+		net = dev_net(skb->dev);
+
+		while ((raw_sk = __raw_v4_lookup(net, raw_sk, protocol,
+						iph->daddr, iph->saddr,
+						skb->dev->ifindex)) != NULL) {
+			raw_err(raw_sk, skb, info);
+			raw_sk = sk_next(raw_sk);
+			iph = (struct iphdr *)skb->data;
+		}
+	}
+	read_unlock(&raw_v4_hashinfo.lock);
+}
+
+static int raw_rcv_skb(struct sock * sk, struct sk_buff * skb)
+{
+	/* Charge it to the socket. */
+
+	if (sock_queue_rcv_skb(sk, skb) < 0) {
+		atomic_inc(&sk->sk_drops);
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	return NET_RX_SUCCESS;
+}
+
+int raw_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
+		atomic_inc(&sk->sk_drops);
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+	nf_reset(skb);
+
+	skb_push(skb, skb->data - skb_network_header(skb));
+
+	raw_rcv_skb(sk, skb);
+	return 0;
+}
+
+static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
+			struct rtable *rt,
+			unsigned int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct net *net = sock_net(sk);
+	struct iphdr *iph;
+	struct sk_buff *skb;
+	unsigned int iphlen;
+	int err;
+
+	if (length > rt->u.dst.dev->mtu) {
+		ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport,
+			       rt->u.dst.dev->mtu);
+		return -EMSGSIZE;
+	}
+	if (flags&MSG_PROBE)
+		goto out;
+
+	skb = sock_alloc_send_skb(sk,
+				  length + LL_ALLOCATED_SPACE(rt->u.dst.dev) + 15,
+				  flags & MSG_DONTWAIT, &err);
+	if (skb == NULL)
+		goto error;
+	skb_reserve(skb, LL_RESERVED_SPACE(rt->u.dst.dev));
+
+	skb->priority = sk->sk_priority;
+	skb->mark = sk->sk_mark;
+	skb->dst = dst_clone(&rt->u.dst);
+
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	skb_put(skb, length);
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	skb->transport_header = skb->network_header;
+	err = memcpy_fromiovecend((void *)iph, from, 0, length);
+	if (err)
+		goto error_fault;
+
+	/* We don't modify invalid header */
+	iphlen = iph->ihl * 4;
+	if (iphlen >= sizeof(*iph) && iphlen <= length) {
+		if (!iph->saddr)
+			iph->saddr = rt->rt_src;
+		iph->check   = 0;
+		iph->tot_len = htons(length);
+		if (!iph->id)
+			ip_select_ident(iph, &rt->u.dst, NULL);
+
+		iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+	}
+	if (iph->protocol == IPPROTO_ICMP)
+		icmp_out_count(net, ((struct icmphdr *)
+			skb_transport_header(skb))->type);
+
+	err = NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
+		      dst_output);
+	if (err > 0)
+		err = inet->recverr ? net_xmit_errno(err) : 0;
+	if (err)
+		goto error;
+out:
+	return 0;
+
+error_fault:
+	err = -EFAULT;
+	kfree_skb(skb);
+error:
+	IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);
+	return err;
+}
+
+static int raw_probe_proto_opt(struct flowi *fl, struct msghdr *msg)
+{
+	struct iovec *iov;
+	u8 __user *type = NULL;
+	u8 __user *code = NULL;
+	int probed = 0;
+	unsigned int i;
+
+	if (!msg->msg_iov)
+		return 0;
+
+	for (i = 0; i < msg->msg_iovlen; i++) {
+		iov = &msg->msg_iov[i];
+		if (!iov)
+			continue;
+
+		switch (fl->proto) {
+		case IPPROTO_ICMP:
+			/* check if one-byte field is readable or not. */
+			if (iov->iov_base && iov->iov_len < 1)
+				break;
+
+			if (!type) {
+				type = iov->iov_base;
+				/* check if code field is readable or not. */
+				if (iov->iov_len > 1)
+					code = type + 1;
+			} else if (!code)
+				code = iov->iov_base;
+
+			if (type && code) {
+				if (get_user(fl->fl_icmp_type, type) ||
+				    get_user(fl->fl_icmp_code, code))
+					return -EFAULT;
+				probed = 1;
+			}
+			break;
+		default:
+			probed = 1;
+			break;
+		}
+		if (probed)
+			break;
+	}
+	return 0;
+}
+
+static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		       size_t len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ipcm_cookie ipc;
+	struct rtable *rt = NULL;
+	int free = 0;
+	__be32 daddr;
+	__be32 saddr;
+	u8  tos;
+	int err;
+
+	err = -EMSGSIZE;
+	if (len > 0xFFFF)
+		goto out;
+
+	/*
+	 *	Check the flags.
+	 */
+
+	err = -EOPNOTSUPP;
+	if (msg->msg_flags & MSG_OOB)	/* Mirror BSD error message */
+		goto out;               /* compatibility */
+
+	/*
+	 *	Get and verify the address.
+	 */
+
+	if (msg->msg_namelen) {
+		struct sockaddr_in *usin = (struct sockaddr_in*)msg->msg_name;
+		err = -EINVAL;
+		if (msg->msg_namelen < sizeof(*usin))
+			goto out;
+		if (usin->sin_family != AF_INET) {
+			static int complained;
+			if (!complained++)
+				printk(KERN_INFO "%s forgot to set AF_INET in "
+						 "raw sendmsg. Fix it!\n",
+						 current->comm);
+			err = -EAFNOSUPPORT;
+			if (usin->sin_family)
+				goto out;
+		}
+		daddr = usin->sin_addr.s_addr;
+		/* ANK: I did not forget to get protocol from port field.
+		 * I just do not know, who uses this weirdness.
+		 * IP_HDRINCL is much more convenient.
+		 */
+	} else {
+		err = -EDESTADDRREQ;
+		if (sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+		daddr = inet->daddr;
+	}
+
+	ipc.addr = inet->saddr;
+	ipc.opt = NULL;
+	ipc.oif = sk->sk_bound_dev_if;
+
+	if (msg->msg_controllen) {
+		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
+		if (err)
+			goto out;
+		if (ipc.opt)
+			free = 1;
+	}
+
+	saddr = ipc.addr;
+	ipc.addr = daddr;
+
+	if (!ipc.opt)
+		ipc.opt = inet->opt;
+
+	if (ipc.opt) {
+		err = -EINVAL;
+		/* Linux does not mangle headers on raw sockets,
+		 * so that IP options + IP_HDRINCL is non-sense.
+		 */
+		if (inet->hdrincl)
+			goto done;
+		if (ipc.opt->srr) {
+			if (!daddr)
+				goto done;
+			daddr = ipc.opt->faddr;
+		}
+	}
+	tos = RT_CONN_FLAGS(sk);
+	if (msg->msg_flags & MSG_DONTROUTE)
+		tos |= RTO_ONLINK;
+
+	if (ipv4_is_multicast(daddr)) {
+		if (!ipc.oif)
+			ipc.oif = inet->mc_index;
+		if (!saddr)
+			saddr = inet->mc_addr;
+	}
+
+	{
+		struct flowi fl = { .oif = ipc.oif,
+				    .mark = sk->sk_mark,
+				    .nl_u = { .ip4_u =
+					      { .daddr = daddr,
+						.saddr = saddr,
+						.tos = tos } },
+				    .proto = inet->hdrincl ? IPPROTO_RAW :
+							     sk->sk_protocol,
+				  };
+		if (!inet->hdrincl) {
+			err = raw_probe_proto_opt(&fl, msg);
+			if (err)
+				goto done;
+		}
+
+		security_sk_classify_flow(sk, &fl);
+		err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 1);
+	}
+	if (err)
+		goto done;
+
+	err = -EACCES;
+	if (rt->rt_flags & RTCF_BROADCAST && !sock_flag(sk, SOCK_BROADCAST))
+		goto done;
+
+	if (msg->msg_flags & MSG_CONFIRM)
+		goto do_confirm;
+back_from_confirm:
+
+	if (inet->hdrincl)
+		err = raw_send_hdrinc(sk, msg->msg_iov, len,
+					rt, msg->msg_flags);
+
+	 else {
+		if (!ipc.addr)
+			ipc.addr = rt->rt_dst;
+		lock_sock(sk);
+		err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, len, 0,
+					&ipc, rt, msg->msg_flags);
+		if (err)
+			ip_flush_pending_frames(sk);
+		else if (!(msg->msg_flags & MSG_MORE))
+			err = ip_push_pending_frames(sk);
+		release_sock(sk);
+	}
+done:
+	if (free)
+		kfree(ipc.opt);
+	ip_rt_put(rt);
+
+out:
+	if (err < 0)
+		return err;
+	return len;
+
+do_confirm:
+	dst_confirm(&rt->u.dst);
+	if (!(msg->msg_flags & MSG_PROBE) || len)
+		goto back_from_confirm;
+	err = 0;
+	goto done;
+}
+
+static void raw_close(struct sock *sk, long timeout)
+{
+	/*
+	 * Raw sockets may have direct kernel refereneces. Kill them.
+	 */
+	ip_ra_control(sk, 0, NULL);
+
+	sk_common_release(sk);
+}
+
+static void raw_destroy(struct sock *sk)
+{
+	lock_sock(sk);
+	ip_flush_pending_frames(sk);
+	release_sock(sk);
+}
+
+/* This gets rid of all the nasties in af_inet. -DaveM */
+static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
+	int ret = -EINVAL;
+	int chk_addr_ret;
+
+	if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_in))
+		goto out;
+	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
+	ret = -EADDRNOTAVAIL;
+	if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&
+	    chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)
+		goto out;
+	inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
+	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
+		inet->saddr = 0;  /* Use device */
+	sk_dst_reset(sk);
+	ret = 0;
+out:	return ret;
+}
+
+/*
+ *	This should be easy, if there is something there
+ *	we return it, otherwise we block.
+ */
+
+static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		       size_t len, int noblock, int flags, int *addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	size_t copied = 0;
+	int err = -EOPNOTSUPP;
+	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
+	struct sk_buff *skb;
+
+	if (flags & MSG_OOB)
+		goto out;
+
+	if (addr_len)
+		*addr_len = sizeof(*sin);
+
+	if (flags & MSG_ERRQUEUE) {
+		err = ip_recv_error(sk, msg, len);
+		goto out;
+	}
+
+	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!skb)
+		goto out;
+
+	copied = skb->len;
+	if (len < copied) {
+		msg->msg_flags |= MSG_TRUNC;
+		copied = len;
+	}
+
+	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	if (err)
+		goto done;
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	/* Copy the address. */
+	if (sin) {
+		sin->sin_family = AF_INET;
+		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
+		sin->sin_port = 0;
+		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
+	}
+	if (inet->cmsg_flags)
+		ip_cmsg_recv(msg, skb);
+	if (flags & MSG_TRUNC)
+		copied = skb->len;
+done:
+	skb_free_datagram(sk, skb);
+out:
+	if (err)
+		return err;
+	return copied;
+}
+
+static int raw_init(struct sock *sk)
+{
+	struct raw_sock *rp = raw_sk(sk);
+
+	if (inet_sk(sk)->num == IPPROTO_ICMP)
+		memset(&rp->filter, 0, sizeof(rp->filter));
+	return 0;
+}
+
+static int raw_seticmpfilter(struct sock *sk, char __user *optval, int optlen)
+{
+	if (optlen > sizeof(struct icmp_filter))
+		optlen = sizeof(struct icmp_filter);
+	if (copy_from_user(&raw_sk(sk)->filter, optval, optlen))
+		return -EFAULT;
+	return 0;
+}
+
+static int raw_geticmpfilter(struct sock *sk, char __user *optval, int __user *optlen)
+{
+	int len, ret = -EFAULT;
+
+	if (get_user(len, optlen))
+		goto out;
+	ret = -EINVAL;
+	if (len < 0)
+		goto out;
+	if (len > sizeof(struct icmp_filter))
+		len = sizeof(struct icmp_filter);
+	ret = -EFAULT;
+	if (put_user(len, optlen) ||
+	    copy_to_user(optval, &raw_sk(sk)->filter, len))
+		goto out;
+	ret = 0;
+out:	return ret;
+}
+
+static int do_raw_setsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int optlen)
+{
+	if (optname == ICMP_FILTER) {
+		if (inet_sk(sk)->num != IPPROTO_ICMP)
+			return -EOPNOTSUPP;
+		else
+			return raw_seticmpfilter(sk, optval, optlen);
+	}
+	return -ENOPROTOOPT;
+}
+
+static int raw_setsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int optlen)
+{
+	if (level != SOL_RAW)
+		return ip_setsockopt(sk, level, optname, optval, optlen);
+	return do_raw_setsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+static int compat_raw_setsockopt(struct sock *sk, int level, int optname,
+				 char __user *optval, int optlen)
+{
+	if (level != SOL_RAW)
+		return compat_ip_setsockopt(sk, level, optname, optval, optlen);
+	return do_raw_setsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+
+static int do_raw_getsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	if (optname == ICMP_FILTER) {
+		if (inet_sk(sk)->num != IPPROTO_ICMP)
+			return -EOPNOTSUPP;
+		else
+			return raw_geticmpfilter(sk, optval, optlen);
+	}
+	return -ENOPROTOOPT;
+}
+
+static int raw_getsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	if (level != SOL_RAW)
+		return ip_getsockopt(sk, level, optname, optval, optlen);
+	return do_raw_getsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+static int compat_raw_getsockopt(struct sock *sk, int level, int optname,
+				 char __user *optval, int __user *optlen)
+{
+	if (level != SOL_RAW)
+		return compat_ip_getsockopt(sk, level, optname, optval, optlen);
+	return do_raw_getsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+
+static int raw_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+		case SIOCOUTQ: {
+			int amount = atomic_read(&sk->sk_wmem_alloc);
+			return put_user(amount, (int __user *)arg);
+		}
+		case SIOCINQ: {
+			struct sk_buff *skb;
+			int amount = 0;
+
+			spin_lock_bh(&sk->sk_receive_queue.lock);
+			skb = skb_peek(&sk->sk_receive_queue);
+			if (skb != NULL)
+				amount = skb->len;
+			spin_unlock_bh(&sk->sk_receive_queue.lock);
+			return put_user(amount, (int __user *)arg);
+		}
+
+		default:
+#ifdef CONFIG_IP_MROUTE
+			return ipmr_ioctl(sk, cmd, (void __user *)arg);
+#else
+			return -ENOIOCTLCMD;
+#endif
+	}
+}
+
+struct proto raw_prot = {
+	.name		   = "RAW",
+	.owner		   = THIS_MODULE,
+	.close		   = raw_close,
+	.destroy	   = raw_destroy,
+	.connect	   = ip4_datagram_connect,
+	.disconnect	   = udp_disconnect,
+	.ioctl		   = raw_ioctl,
+	.init		   = raw_init,
+	.setsockopt	   = raw_setsockopt,
+	.getsockopt	   = raw_getsockopt,
+	.sendmsg	   = raw_sendmsg,
+	.recvmsg	   = raw_recvmsg,
+	.bind		   = raw_bind,
+	.backlog_rcv	   = raw_rcv_skb,
+	.hash		   = raw_hash_sk,
+	.unhash		   = raw_unhash_sk,
+	.obj_size	   = sizeof(struct raw_sock),
+	.h.raw_hash	   = &raw_v4_hashinfo,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_raw_setsockopt,
+	.compat_getsockopt = compat_raw_getsockopt,
+#endif
+};
+
+#ifdef CONFIG_PROC_FS
+static struct sock *raw_get_first(struct seq_file *seq)
+{
+	struct sock *sk;
+	struct raw_iter_state* state = raw_seq_private(seq);
+
+	for (state->bucket = 0; state->bucket < RAW_HTABLE_SIZE;
+			++state->bucket) {
+		struct hlist_node *node;
+
+		sk_for_each(sk, node, &state->h->ht[state->bucket])
+			if (sock_net(sk) == seq_file_net(seq))
+				goto found;
+	}
+	sk = NULL;
+found:
+	return sk;
+}
+
+static struct sock *raw_get_next(struct seq_file *seq, struct sock *sk)
+{
+	struct raw_iter_state* state = raw_seq_private(seq);
+
+	do {
+		sk = sk_next(sk);
+try_again:
+		;
+	} while (sk && sock_net(sk) != seq_file_net(seq));
+
+	if (!sk && ++state->bucket < RAW_HTABLE_SIZE) {
+		sk = sk_head(&state->h->ht[state->bucket]);
+		goto try_again;
+	}
+	return sk;
+}
+
+static struct sock *raw_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct sock *sk = raw_get_first(seq);
+
+	if (sk)
+		while (pos && (sk = raw_get_next(seq, sk)) != NULL)
+			--pos;
+	return pos ? NULL : sk;
+}
+
+void *raw_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct raw_iter_state *state = raw_seq_private(seq);
+
+	read_lock(&state->h->lock);
+	return *pos ? raw_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+EXPORT_SYMBOL_GPL(raw_seq_start);
+
+void *raw_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct sock *sk;
+
+	if (v == SEQ_START_TOKEN)
+		sk = raw_get_first(seq);
+	else
+		sk = raw_get_next(seq, v);
+	++*pos;
+	return sk;
+}
+EXPORT_SYMBOL_GPL(raw_seq_next);
+
+void raw_seq_stop(struct seq_file *seq, void *v)
+{
+	struct raw_iter_state *state = raw_seq_private(seq);
+
+	read_unlock(&state->h->lock);
+}
+EXPORT_SYMBOL_GPL(raw_seq_stop);
+
+static void raw_sock_seq_show(struct seq_file *seq, struct sock *sp, int i)
+{
+	struct inet_sock *inet = inet_sk(sp);
+	__be32 dest = inet->daddr,
+	       src = inet->rcv_saddr;
+	__u16 destp = 0,
+	      srcp  = inet->num;
+
+	seq_printf(seq, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d\n",
+		i, src, srcp, dest, destp, sp->sk_state,
+		atomic_read(&sp->sk_wmem_alloc),
+		atomic_read(&sp->sk_rmem_alloc),
+		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
+		atomic_read(&sp->sk_refcnt), sp, atomic_read(&sp->sk_drops));
+}
+
+static int raw_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_printf(seq, "  sl  local_address rem_address   st tx_queue "
+				"rx_queue tr tm->when retrnsmt   uid  timeout "
+				"inode ref pointer drops\n");
+	else
+		raw_sock_seq_show(seq, v, raw_seq_private(seq)->bucket);
+	return 0;
+}
+
+static const struct seq_operations raw_seq_ops = {
+	.start = raw_seq_start,
+	.next  = raw_seq_next,
+	.stop  = raw_seq_stop,
+	.show  = raw_seq_show,
+};
+
+int raw_seq_open(struct inode *ino, struct file *file,
+		 struct raw_hashinfo *h, const struct seq_operations *ops)
+{
+	int err;
+	struct raw_iter_state *i;
+
+	err = seq_open_net(ino, file, ops, sizeof(struct raw_iter_state));
+	if (err < 0)
+		return err;
+
+	i = raw_seq_private((struct seq_file *)file->private_data);
+	i->h = h;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(raw_seq_open);
+
+static int raw_v4_seq_open(struct inode *inode, struct file *file)
+{
+	return raw_seq_open(inode, file, &raw_v4_hashinfo, &raw_seq_ops);
+}
+
+static const struct file_operations raw_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = raw_v4_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release_net,
+};
+
+static __net_init int raw_init_net(struct net *net)
+{
+	if (!proc_net_fops_create(net, "raw", S_IRUGO, &raw_seq_fops))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static __net_exit void raw_exit_net(struct net *net)
+{
+	proc_net_remove(net, "raw");
+}
+
+static __net_initdata struct pernet_operations raw_net_ops = {
+	.init = raw_init_net,
+	.exit = raw_exit_net,
+};
+
+int __init raw_proc_init(void)
+{
+	return register_pernet_subsys(&raw_net_ops);
+}
+
+void __init raw_proc_exit(void)
+{
+	unregister_pernet_subsys(&raw_net_ops);
+}
+#endif /* CONFIG_PROC_FS */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
new file mode 100644
index 0000000..2ea6dcc
--- /dev/null
+++ b/net/ipv4/route.c
@@ -0,0 +1,3324 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		ROUTE - implementation of the IP router.
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Linus Torvalds, <Linus.Torvalds@helsinki.fi>
+ *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ * Fixes:
+ *		Alan Cox	:	Verify area fixes.
+ *		Alan Cox	:	cli() protects routing changes
+ *		Rui Oliveira	:	ICMP routing table updates
+ *		(rco@di.uminho.pt)	Routing table insertion and update
+ *		Linus Torvalds	:	Rewrote bits to be sensible
+ *		Alan Cox	:	Added BSD route gw semantics
+ *		Alan Cox	:	Super /proc >4K
+ *		Alan Cox	:	MTU in route table
+ *		Alan Cox	: 	MSS actually. Also added the window
+ *					clamper.
+ *		Sam Lantinga	:	Fixed route matching in rt_del()
+ *		Alan Cox	:	Routing cache support.
+ *		Alan Cox	:	Removed compatibility cruft.
+ *		Alan Cox	:	RTF_REJECT support.
+ *		Alan Cox	:	TCP irtt support.
+ *		Jonathan Naylor	:	Added Metric support.
+ *	Miquel van Smoorenburg	:	BSD API fixes.
+ *	Miquel van Smoorenburg	:	Metrics.
+ *		Alan Cox	:	Use __u32 properly
+ *		Alan Cox	:	Aligned routing errors more closely with BSD
+ *					our system is still very different.
+ *		Alan Cox	:	Faster /proc handling
+ *	Alexey Kuznetsov	:	Massive rework to support tree based routing,
+ *					routing caches and better behaviour.
+ *
+ *		Olaf Erb	:	irtt wasn't being copied right.
+ *		Bjorn Ekwall	:	Kerneld route support.
+ *		Alan Cox	:	Multicast fixed (I hope)
+ * 		Pavel Krauz	:	Limited broadcast fixed
+ *		Mike McLagan	:	Routing by source
+ *	Alexey Kuznetsov	:	End of old history. Split to fib.c and
+ *					route.c and rewritten from scratch.
+ *		Andi Kleen	:	Load-limit warning messages.
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
+ *	Vitaly E. Lavrov	:	Race condition in ip_route_input_slow.
+ *	Tobias Ringstrom	:	Uninitialized res.type in ip_route_output_slow.
+ *	Vladimir V. Ivanov	:	IP rule info (flowid) is really useful.
+ *		Marc Boucher	:	routing by fwmark
+ *	Robert Olsson		:	Added rt_cache statistics
+ *	Arnaldo C. Melo		:	Convert proc stuff to seq_file
+ *	Eric Dumazet		:	hashed spinlocks and rt_check_expire() fixes.
+ * 	Ilia Sotnikov		:	Ignore TOS on PMTUD and Redirect
+ * 	Ilia Sotnikov		:	Removed TOS from hash calculations
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/workqueue.h>
+#include <linux/skbuff.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/pkt_sched.h>
+#include <linux/mroute.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/rcupdate.h>
+#include <linux/times.h>
+#include <net/dst.h>
+#include <net/net_namespace.h>
+#include <net/protocol.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/inetpeer.h>
+#include <net/sock.h>
+#include <net/ip_fib.h>
+#include <net/arp.h>
+#include <net/tcp.h>
+#include <net/icmp.h>
+#include <net/xfrm.h>
+#include <net/netevent.h>
+#include <net/rtnetlink.h>
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+
+#define RT_FL_TOS(oldflp) \
+    ((u32)(oldflp->fl4_tos & (IPTOS_RT_MASK | RTO_ONLINK)))
+
+#define IP_MAX_MTU	0xFFF0
+
+#define RT_GC_TIMEOUT (300*HZ)
+
+static int ip_rt_max_size;
+static int ip_rt_gc_timeout __read_mostly	= RT_GC_TIMEOUT;
+static int ip_rt_gc_interval __read_mostly	= 60 * HZ;
+static int ip_rt_gc_min_interval __read_mostly	= HZ / 2;
+static int ip_rt_redirect_number __read_mostly	= 9;
+static int ip_rt_redirect_load __read_mostly	= HZ / 50;
+static int ip_rt_redirect_silence __read_mostly	= ((HZ / 50) << (9 + 1));
+static int ip_rt_error_cost __read_mostly	= HZ;
+static int ip_rt_error_burst __read_mostly	= 5 * HZ;
+static int ip_rt_gc_elasticity __read_mostly	= 8;
+static int ip_rt_mtu_expires __read_mostly	= 10 * 60 * HZ;
+static int ip_rt_min_pmtu __read_mostly		= 512 + 20 + 20;
+static int ip_rt_min_advmss __read_mostly	= 256;
+static int ip_rt_secret_interval __read_mostly	= 10 * 60 * HZ;
+
+static void rt_worker_func(struct work_struct *work);
+static DECLARE_DELAYED_WORK(expires_work, rt_worker_func);
+
+/*
+ *	Interface to generic destination cache.
+ */
+
+static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
+static void		 ipv4_dst_destroy(struct dst_entry *dst);
+static void		 ipv4_dst_ifdown(struct dst_entry *dst,
+					 struct net_device *dev, int how);
+static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
+static void		 ipv4_link_failure(struct sk_buff *skb);
+static void		 ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
+static int rt_garbage_collect(struct dst_ops *ops);
+
+
+static struct dst_ops ipv4_dst_ops = {
+	.family =		AF_INET,
+	.protocol =		__constant_htons(ETH_P_IP),
+	.gc =			rt_garbage_collect,
+	.check =		ipv4_dst_check,
+	.destroy =		ipv4_dst_destroy,
+	.ifdown =		ipv4_dst_ifdown,
+	.negative_advice =	ipv4_negative_advice,
+	.link_failure =		ipv4_link_failure,
+	.update_pmtu =		ip_rt_update_pmtu,
+	.local_out =		__ip_local_out,
+	.entry_size =		sizeof(struct rtable),
+	.entries =		ATOMIC_INIT(0),
+};
+
+#define ECN_OR_COST(class)	TC_PRIO_##class
+
+const __u8 ip_tos2prio[16] = {
+	TC_PRIO_BESTEFFORT,
+	ECN_OR_COST(FILLER),
+	TC_PRIO_BESTEFFORT,
+	ECN_OR_COST(BESTEFFORT),
+	TC_PRIO_BULK,
+	ECN_OR_COST(BULK),
+	TC_PRIO_BULK,
+	ECN_OR_COST(BULK),
+	TC_PRIO_INTERACTIVE,
+	ECN_OR_COST(INTERACTIVE),
+	TC_PRIO_INTERACTIVE,
+	ECN_OR_COST(INTERACTIVE),
+	TC_PRIO_INTERACTIVE_BULK,
+	ECN_OR_COST(INTERACTIVE_BULK),
+	TC_PRIO_INTERACTIVE_BULK,
+	ECN_OR_COST(INTERACTIVE_BULK)
+};
+
+
+/*
+ * Route cache.
+ */
+
+/* The locking scheme is rather straight forward:
+ *
+ * 1) Read-Copy Update protects the buckets of the central route hash.
+ * 2) Only writers remove entries, and they hold the lock
+ *    as they look at rtable reference counts.
+ * 3) Only readers acquire references to rtable entries,
+ *    they do so with atomic increments and with the
+ *    lock held.
+ */
+
+struct rt_hash_bucket {
+	struct rtable	*chain;
+};
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
+	defined(CONFIG_PROVE_LOCKING)
+/*
+ * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
+ * The size of this table is a power of two and depends on the number of CPUS.
+ * (on lockdep we have a quite big spinlock_t, so keep the size down there)
+ */
+#ifdef CONFIG_LOCKDEP
+# define RT_HASH_LOCK_SZ	256
+#else
+# if NR_CPUS >= 32
+#  define RT_HASH_LOCK_SZ	4096
+# elif NR_CPUS >= 16
+#  define RT_HASH_LOCK_SZ	2048
+# elif NR_CPUS >= 8
+#  define RT_HASH_LOCK_SZ	1024
+# elif NR_CPUS >= 4
+#  define RT_HASH_LOCK_SZ	512
+# else
+#  define RT_HASH_LOCK_SZ	256
+# endif
+#endif
+
+static spinlock_t	*rt_hash_locks;
+# define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
+
+static __init void rt_hash_lock_init(void)
+{
+	int i;
+
+	rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
+			GFP_KERNEL);
+	if (!rt_hash_locks)
+		panic("IP: failed to allocate rt_hash_locks\n");
+
+	for (i = 0; i < RT_HASH_LOCK_SZ; i++)
+		spin_lock_init(&rt_hash_locks[i]);
+}
+#else
+# define rt_hash_lock_addr(slot) NULL
+
+static inline void rt_hash_lock_init(void)
+{
+}
+#endif
+
+static struct rt_hash_bucket 	*rt_hash_table __read_mostly;
+static unsigned			rt_hash_mask __read_mostly;
+static unsigned int		rt_hash_log  __read_mostly;
+
+static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
+#define RT_CACHE_STAT_INC(field) \
+	(__raw_get_cpu_var(rt_cache_stat).field++)
+
+static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
+		int genid)
+{
+	return jhash_3words((__force u32)(__be32)(daddr),
+			    (__force u32)(__be32)(saddr),
+			    idx, genid)
+		& rt_hash_mask;
+}
+
+static inline int rt_genid(struct net *net)
+{
+	return atomic_read(&net->ipv4.rt_genid);
+}
+
+#ifdef CONFIG_PROC_FS
+struct rt_cache_iter_state {
+	struct seq_net_private p;
+	int bucket;
+	int genid;
+};
+
+static struct rtable *rt_cache_get_first(struct seq_file *seq)
+{
+	struct rt_cache_iter_state *st = seq->private;
+	struct rtable *r = NULL;
+
+	for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
+		if (!rt_hash_table[st->bucket].chain)
+			continue;
+		rcu_read_lock_bh();
+		r = rcu_dereference(rt_hash_table[st->bucket].chain);
+		while (r) {
+			if (dev_net(r->u.dst.dev) == seq_file_net(seq) &&
+			    r->rt_genid == st->genid)
+				return r;
+			r = rcu_dereference(r->u.dst.rt_next);
+		}
+		rcu_read_unlock_bh();
+	}
+	return r;
+}
+
+static struct rtable *__rt_cache_get_next(struct seq_file *seq,
+					  struct rtable *r)
+{
+	struct rt_cache_iter_state *st = seq->private;
+
+	r = r->u.dst.rt_next;
+	while (!r) {
+		rcu_read_unlock_bh();
+		do {
+			if (--st->bucket < 0)
+				return NULL;
+		} while (!rt_hash_table[st->bucket].chain);
+		rcu_read_lock_bh();
+		r = rt_hash_table[st->bucket].chain;
+	}
+	return rcu_dereference(r);
+}
+
+static struct rtable *rt_cache_get_next(struct seq_file *seq,
+					struct rtable *r)
+{
+	struct rt_cache_iter_state *st = seq->private;
+	while ((r = __rt_cache_get_next(seq, r)) != NULL) {
+		if (dev_net(r->u.dst.dev) != seq_file_net(seq))
+			continue;
+		if (r->rt_genid == st->genid)
+			break;
+	}
+	return r;
+}
+
+static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct rtable *r = rt_cache_get_first(seq);
+
+	if (r)
+		while (pos && (r = rt_cache_get_next(seq, r)))
+			--pos;
+	return pos ? NULL : r;
+}
+
+static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct rt_cache_iter_state *st = seq->private;
+	if (*pos)
+		return rt_cache_get_idx(seq, *pos - 1);
+	st->genid = rt_genid(seq_file_net(seq));
+	return SEQ_START_TOKEN;
+}
+
+static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct rtable *r;
+
+	if (v == SEQ_START_TOKEN)
+		r = rt_cache_get_first(seq);
+	else
+		r = rt_cache_get_next(seq, v);
+	++*pos;
+	return r;
+}
+
+static void rt_cache_seq_stop(struct seq_file *seq, void *v)
+{
+	if (v && v != SEQ_START_TOKEN)
+		rcu_read_unlock_bh();
+}
+
+static int rt_cache_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_printf(seq, "%-127s\n",
+			   "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
+			   "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
+			   "HHUptod\tSpecDst");
+	else {
+		struct rtable *r = v;
+		int len;
+
+		seq_printf(seq, "%s\t%08lX\t%08lX\t%8X\t%d\t%u\t%d\t"
+			      "%08lX\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
+			r->u.dst.dev ? r->u.dst.dev->name : "*",
+			(unsigned long)r->rt_dst, (unsigned long)r->rt_gateway,
+			r->rt_flags, atomic_read(&r->u.dst.__refcnt),
+			r->u.dst.__use, 0, (unsigned long)r->rt_src,
+			(dst_metric(&r->u.dst, RTAX_ADVMSS) ?
+			     (int)dst_metric(&r->u.dst, RTAX_ADVMSS) + 40 : 0),
+			dst_metric(&r->u.dst, RTAX_WINDOW),
+			(int)((dst_metric(&r->u.dst, RTAX_RTT) >> 3) +
+			      dst_metric(&r->u.dst, RTAX_RTTVAR)),
+			r->fl.fl4_tos,
+			r->u.dst.hh ? atomic_read(&r->u.dst.hh->hh_refcnt) : -1,
+			r->u.dst.hh ? (r->u.dst.hh->hh_output ==
+				       dev_queue_xmit) : 0,
+			r->rt_spec_dst, &len);
+
+		seq_printf(seq, "%*s\n", 127 - len, "");
+	}
+	return 0;
+}
+
+static const struct seq_operations rt_cache_seq_ops = {
+	.start  = rt_cache_seq_start,
+	.next   = rt_cache_seq_next,
+	.stop   = rt_cache_seq_stop,
+	.show   = rt_cache_seq_show,
+};
+
+static int rt_cache_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open_net(inode, file, &rt_cache_seq_ops,
+			sizeof(struct rt_cache_iter_state));
+}
+
+static const struct file_operations rt_cache_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = rt_cache_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release_net,
+};
+
+
+static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	int cpu;
+
+	if (*pos == 0)
+		return SEQ_START_TOKEN;
+
+	for (cpu = *pos-1; cpu < NR_CPUS; ++cpu) {
+		if (!cpu_possible(cpu))
+			continue;
+		*pos = cpu+1;
+		return &per_cpu(rt_cache_stat, cpu);
+	}
+	return NULL;
+}
+
+static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	int cpu;
+
+	for (cpu = *pos; cpu < NR_CPUS; ++cpu) {
+		if (!cpu_possible(cpu))
+			continue;
+		*pos = cpu+1;
+		return &per_cpu(rt_cache_stat, cpu);
+	}
+	return NULL;
+
+}
+
+static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
+{
+
+}
+
+static int rt_cpu_seq_show(struct seq_file *seq, void *v)
+{
+	struct rt_cache_stat *st = v;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, "entries  in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src  out_hit out_slow_tot out_slow_mc  gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
+		return 0;
+	}
+
+	seq_printf(seq,"%08x  %08x %08x %08x %08x %08x %08x %08x "
+		   " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
+		   atomic_read(&ipv4_dst_ops.entries),
+		   st->in_hit,
+		   st->in_slow_tot,
+		   st->in_slow_mc,
+		   st->in_no_route,
+		   st->in_brd,
+		   st->in_martian_dst,
+		   st->in_martian_src,
+
+		   st->out_hit,
+		   st->out_slow_tot,
+		   st->out_slow_mc,
+
+		   st->gc_total,
+		   st->gc_ignored,
+		   st->gc_goal_miss,
+		   st->gc_dst_overflow,
+		   st->in_hlist_search,
+		   st->out_hlist_search
+		);
+	return 0;
+}
+
+static const struct seq_operations rt_cpu_seq_ops = {
+	.start  = rt_cpu_seq_start,
+	.next   = rt_cpu_seq_next,
+	.stop   = rt_cpu_seq_stop,
+	.show   = rt_cpu_seq_show,
+};
+
+
+static int rt_cpu_seq_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &rt_cpu_seq_ops);
+}
+
+static const struct file_operations rt_cpu_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = rt_cpu_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release,
+};
+
+#ifdef CONFIG_NET_CLS_ROUTE
+static int ip_rt_acct_read(char *buffer, char **start, off_t offset,
+			   int length, int *eof, void *data)
+{
+	unsigned int i;
+
+	if ((offset & 3) || (length & 3))
+		return -EIO;
+
+	if (offset >= sizeof(struct ip_rt_acct) * 256) {
+		*eof = 1;
+		return 0;
+	}
+
+	if (offset + length >= sizeof(struct ip_rt_acct) * 256) {
+		length = sizeof(struct ip_rt_acct) * 256 - offset;
+		*eof = 1;
+	}
+
+	offset /= sizeof(u32);
+
+	if (length > 0) {
+		u32 *dst = (u32 *) buffer;
+
+		*start = buffer;
+		memset(dst, 0, length);
+
+		for_each_possible_cpu(i) {
+			unsigned int j;
+			u32 *src;
+
+			src = ((u32 *) per_cpu_ptr(ip_rt_acct, i)) + offset;
+			for (j = 0; j < length/4; j++)
+				dst[j] += src[j];
+		}
+	}
+	return length;
+}
+#endif
+
+static int __net_init ip_rt_do_proc_init(struct net *net)
+{
+	struct proc_dir_entry *pde;
+
+	pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
+			&rt_cache_seq_fops);
+	if (!pde)
+		goto err1;
+
+	pde = proc_create("rt_cache", S_IRUGO,
+			  net->proc_net_stat, &rt_cpu_seq_fops);
+	if (!pde)
+		goto err2;
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	pde = create_proc_read_entry("rt_acct", 0, net->proc_net,
+			ip_rt_acct_read, NULL);
+	if (!pde)
+		goto err3;
+#endif
+	return 0;
+
+#ifdef CONFIG_NET_CLS_ROUTE
+err3:
+	remove_proc_entry("rt_cache", net->proc_net_stat);
+#endif
+err2:
+	remove_proc_entry("rt_cache", net->proc_net);
+err1:
+	return -ENOMEM;
+}
+
+static void __net_exit ip_rt_do_proc_exit(struct net *net)
+{
+	remove_proc_entry("rt_cache", net->proc_net_stat);
+	remove_proc_entry("rt_cache", net->proc_net);
+	remove_proc_entry("rt_acct", net->proc_net);
+}
+
+static struct pernet_operations ip_rt_proc_ops __net_initdata =  {
+	.init = ip_rt_do_proc_init,
+	.exit = ip_rt_do_proc_exit,
+};
+
+static int __init ip_rt_proc_init(void)
+{
+	return register_pernet_subsys(&ip_rt_proc_ops);
+}
+
+#else
+static inline int ip_rt_proc_init(void)
+{
+	return 0;
+}
+#endif /* CONFIG_PROC_FS */
+
+static inline void rt_free(struct rtable *rt)
+{
+	call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
+}
+
+static inline void rt_drop(struct rtable *rt)
+{
+	ip_rt_put(rt);
+	call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free);
+}
+
+static inline int rt_fast_clean(struct rtable *rth)
+{
+	/* Kill broadcast/multicast entries very aggresively, if they
+	   collide in hash table with more useful entries */
+	return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
+		rth->fl.iif && rth->u.dst.rt_next;
+}
+
+static inline int rt_valuable(struct rtable *rth)
+{
+	return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
+		rth->u.dst.expires;
+}
+
+static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
+{
+	unsigned long age;
+	int ret = 0;
+
+	if (atomic_read(&rth->u.dst.__refcnt))
+		goto out;
+
+	ret = 1;
+	if (rth->u.dst.expires &&
+	    time_after_eq(jiffies, rth->u.dst.expires))
+		goto out;
+
+	age = jiffies - rth->u.dst.lastuse;
+	ret = 0;
+	if ((age <= tmo1 && !rt_fast_clean(rth)) ||
+	    (age <= tmo2 && rt_valuable(rth)))
+		goto out;
+	ret = 1;
+out:	return ret;
+}
+
+/* Bits of score are:
+ * 31: very valuable
+ * 30: not quite useless
+ * 29..0: usage counter
+ */
+static inline u32 rt_score(struct rtable *rt)
+{
+	u32 score = jiffies - rt->u.dst.lastuse;
+
+	score = ~score & ~(3<<30);
+
+	if (rt_valuable(rt))
+		score |= (1<<31);
+
+	if (!rt->fl.iif ||
+	    !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
+		score |= (1<<30);
+
+	return score;
+}
+
+static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
+{
+	return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
+		(fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr)) |
+		(fl1->mark ^ fl2->mark) |
+		(*(u16 *)&fl1->nl_u.ip4_u.tos ^
+		 *(u16 *)&fl2->nl_u.ip4_u.tos) |
+		(fl1->oif ^ fl2->oif) |
+		(fl1->iif ^ fl2->iif)) == 0;
+}
+
+static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
+{
+	return dev_net(rt1->u.dst.dev) == dev_net(rt2->u.dst.dev);
+}
+
+static inline int rt_is_expired(struct rtable *rth)
+{
+	return rth->rt_genid != rt_genid(dev_net(rth->u.dst.dev));
+}
+
+/*
+ * Perform a full scan of hash table and free all entries.
+ * Can be called by a softirq or a process.
+ * In the later case, we want to be reschedule if necessary
+ */
+static void rt_do_flush(int process_context)
+{
+	unsigned int i;
+	struct rtable *rth, *next;
+	struct rtable * tail;
+
+	for (i = 0; i <= rt_hash_mask; i++) {
+		if (process_context && need_resched())
+			cond_resched();
+		rth = rt_hash_table[i].chain;
+		if (!rth)
+			continue;
+
+		spin_lock_bh(rt_hash_lock_addr(i));
+#ifdef CONFIG_NET_NS
+		{
+		struct rtable ** prev, * p;
+
+		rth = rt_hash_table[i].chain;
+
+		/* defer releasing the head of the list after spin_unlock */
+		for (tail = rth; tail; tail = tail->u.dst.rt_next)
+			if (!rt_is_expired(tail))
+				break;
+		if (rth != tail)
+			rt_hash_table[i].chain = tail;
+
+		/* call rt_free on entries after the tail requiring flush */
+		prev = &rt_hash_table[i].chain;
+		for (p = *prev; p; p = next) {
+			next = p->u.dst.rt_next;
+			if (!rt_is_expired(p)) {
+				prev = &p->u.dst.rt_next;
+			} else {
+				*prev = next;
+				rt_free(p);
+			}
+		}
+		}
+#else
+		rth = rt_hash_table[i].chain;
+		rt_hash_table[i].chain = NULL;
+		tail = NULL;
+#endif
+		spin_unlock_bh(rt_hash_lock_addr(i));
+
+		for (; rth != tail; rth = next) {
+			next = rth->u.dst.rt_next;
+			rt_free(rth);
+		}
+	}
+}
+
+static void rt_check_expire(void)
+{
+	static unsigned int rover;
+	unsigned int i = rover, goal;
+	struct rtable *rth, **rthp;
+	u64 mult;
+
+	mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
+	if (ip_rt_gc_timeout > 1)
+		do_div(mult, ip_rt_gc_timeout);
+	goal = (unsigned int)mult;
+	if (goal > rt_hash_mask)
+		goal = rt_hash_mask + 1;
+	for (; goal > 0; goal--) {
+		unsigned long tmo = ip_rt_gc_timeout;
+
+		i = (i + 1) & rt_hash_mask;
+		rthp = &rt_hash_table[i].chain;
+
+		if (need_resched())
+			cond_resched();
+
+		if (*rthp == NULL)
+			continue;
+		spin_lock_bh(rt_hash_lock_addr(i));
+		while ((rth = *rthp) != NULL) {
+			if (rt_is_expired(rth)) {
+				*rthp = rth->u.dst.rt_next;
+				rt_free(rth);
+				continue;
+			}
+			if (rth->u.dst.expires) {
+				/* Entry is expired even if it is in use */
+				if (time_before_eq(jiffies, rth->u.dst.expires)) {
+					tmo >>= 1;
+					rthp = &rth->u.dst.rt_next;
+					continue;
+				}
+			} else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
+				tmo >>= 1;
+				rthp = &rth->u.dst.rt_next;
+				continue;
+			}
+
+			/* Cleanup aged off entries. */
+			*rthp = rth->u.dst.rt_next;
+			rt_free(rth);
+		}
+		spin_unlock_bh(rt_hash_lock_addr(i));
+	}
+	rover = i;
+}
+
+/*
+ * rt_worker_func() is run in process context.
+ * we call rt_check_expire() to scan part of the hash table
+ */
+static void rt_worker_func(struct work_struct *work)
+{
+	rt_check_expire();
+	schedule_delayed_work(&expires_work, ip_rt_gc_interval);
+}
+
+/*
+ * Pertubation of rt_genid by a small quantity [1..256]
+ * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
+ * many times (2^24) without giving recent rt_genid.
+ * Jenkins hash is strong enough that litle changes of rt_genid are OK.
+ */
+static void rt_cache_invalidate(struct net *net)
+{
+	unsigned char shuffle;
+
+	get_random_bytes(&shuffle, sizeof(shuffle));
+	atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
+}
+
+/*
+ * delay < 0  : invalidate cache (fast : entries will be deleted later)
+ * delay >= 0 : invalidate & flush cache (can be long)
+ */
+void rt_cache_flush(struct net *net, int delay)
+{
+	rt_cache_invalidate(net);
+	if (delay >= 0)
+		rt_do_flush(!in_softirq());
+}
+
+/*
+ * We change rt_genid and let gc do the cleanup
+ */
+static void rt_secret_rebuild(unsigned long __net)
+{
+	struct net *net = (struct net *)__net;
+	rt_cache_invalidate(net);
+	mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
+}
+
+/*
+   Short description of GC goals.
+
+   We want to build algorithm, which will keep routing cache
+   at some equilibrium point, when number of aged off entries
+   is kept approximately equal to newly generated ones.
+
+   Current expiration strength is variable "expire".
+   We try to adjust it dynamically, so that if networking
+   is idle expires is large enough to keep enough of warm entries,
+   and when load increases it reduces to limit cache size.
+ */
+
+static int rt_garbage_collect(struct dst_ops *ops)
+{
+	static unsigned long expire = RT_GC_TIMEOUT;
+	static unsigned long last_gc;
+	static int rover;
+	static int equilibrium;
+	struct rtable *rth, **rthp;
+	unsigned long now = jiffies;
+	int goal;
+
+	/*
+	 * Garbage collection is pretty expensive,
+	 * do not make it too frequently.
+	 */
+
+	RT_CACHE_STAT_INC(gc_total);
+
+	if (now - last_gc < ip_rt_gc_min_interval &&
+	    atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size) {
+		RT_CACHE_STAT_INC(gc_ignored);
+		goto out;
+	}
+
+	/* Calculate number of entries, which we want to expire now. */
+	goal = atomic_read(&ipv4_dst_ops.entries) -
+		(ip_rt_gc_elasticity << rt_hash_log);
+	if (goal <= 0) {
+		if (equilibrium < ipv4_dst_ops.gc_thresh)
+			equilibrium = ipv4_dst_ops.gc_thresh;
+		goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
+		if (goal > 0) {
+			equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
+			goal = atomic_read(&ipv4_dst_ops.entries) - equilibrium;
+		}
+	} else {
+		/* We are in dangerous area. Try to reduce cache really
+		 * aggressively.
+		 */
+		goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
+		equilibrium = atomic_read(&ipv4_dst_ops.entries) - goal;
+	}
+
+	if (now - last_gc >= ip_rt_gc_min_interval)
+		last_gc = now;
+
+	if (goal <= 0) {
+		equilibrium += goal;
+		goto work_done;
+	}
+
+	do {
+		int i, k;
+
+		for (i = rt_hash_mask, k = rover; i >= 0; i--) {
+			unsigned long tmo = expire;
+
+			k = (k + 1) & rt_hash_mask;
+			rthp = &rt_hash_table[k].chain;
+			spin_lock_bh(rt_hash_lock_addr(k));
+			while ((rth = *rthp) != NULL) {
+				if (!rt_is_expired(rth) &&
+					!rt_may_expire(rth, tmo, expire)) {
+					tmo >>= 1;
+					rthp = &rth->u.dst.rt_next;
+					continue;
+				}
+				*rthp = rth->u.dst.rt_next;
+				rt_free(rth);
+				goal--;
+			}
+			spin_unlock_bh(rt_hash_lock_addr(k));
+			if (goal <= 0)
+				break;
+		}
+		rover = k;
+
+		if (goal <= 0)
+			goto work_done;
+
+		/* Goal is not achieved. We stop process if:
+
+		   - if expire reduced to zero. Otherwise, expire is halfed.
+		   - if table is not full.
+		   - if we are called from interrupt.
+		   - jiffies check is just fallback/debug loop breaker.
+		     We will not spin here for long time in any case.
+		 */
+
+		RT_CACHE_STAT_INC(gc_goal_miss);
+
+		if (expire == 0)
+			break;
+
+		expire >>= 1;
+#if RT_CACHE_DEBUG >= 2
+		printk(KERN_DEBUG "expire>> %u %d %d %d\n", expire,
+				atomic_read(&ipv4_dst_ops.entries), goal, i);
+#endif
+
+		if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
+			goto out;
+	} while (!in_softirq() && time_before_eq(jiffies, now));
+
+	if (atomic_read(&ipv4_dst_ops.entries) < ip_rt_max_size)
+		goto out;
+	if (net_ratelimit())
+		printk(KERN_WARNING "dst cache overflow\n");
+	RT_CACHE_STAT_INC(gc_dst_overflow);
+	return 1;
+
+work_done:
+	expire += ip_rt_gc_min_interval;
+	if (expire > ip_rt_gc_timeout ||
+	    atomic_read(&ipv4_dst_ops.entries) < ipv4_dst_ops.gc_thresh)
+		expire = ip_rt_gc_timeout;
+#if RT_CACHE_DEBUG >= 2
+	printk(KERN_DEBUG "expire++ %u %d %d %d\n", expire,
+			atomic_read(&ipv4_dst_ops.entries), goal, rover);
+#endif
+out:	return 0;
+}
+
+static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
+{
+	struct rtable	*rth, **rthp;
+	unsigned long	now;
+	struct rtable *cand, **candp;
+	u32 		min_score;
+	int		chain_length;
+	int attempts = !in_softirq();
+
+restart:
+	chain_length = 0;
+	min_score = ~(u32)0;
+	cand = NULL;
+	candp = NULL;
+	now = jiffies;
+
+	rthp = &rt_hash_table[hash].chain;
+
+	spin_lock_bh(rt_hash_lock_addr(hash));
+	while ((rth = *rthp) != NULL) {
+		if (rt_is_expired(rth)) {
+			*rthp = rth->u.dst.rt_next;
+			rt_free(rth);
+			continue;
+		}
+		if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
+			/* Put it first */
+			*rthp = rth->u.dst.rt_next;
+			/*
+			 * Since lookup is lockfree, the deletion
+			 * must be visible to another weakly ordered CPU before
+			 * the insertion at the start of the hash chain.
+			 */
+			rcu_assign_pointer(rth->u.dst.rt_next,
+					   rt_hash_table[hash].chain);
+			/*
+			 * Since lookup is lockfree, the update writes
+			 * must be ordered for consistency on SMP.
+			 */
+			rcu_assign_pointer(rt_hash_table[hash].chain, rth);
+
+			dst_use(&rth->u.dst, now);
+			spin_unlock_bh(rt_hash_lock_addr(hash));
+
+			rt_drop(rt);
+			*rp = rth;
+			return 0;
+		}
+
+		if (!atomic_read(&rth->u.dst.__refcnt)) {
+			u32 score = rt_score(rth);
+
+			if (score <= min_score) {
+				cand = rth;
+				candp = rthp;
+				min_score = score;
+			}
+		}
+
+		chain_length++;
+
+		rthp = &rth->u.dst.rt_next;
+	}
+
+	if (cand) {
+		/* ip_rt_gc_elasticity used to be average length of chain
+		 * length, when exceeded gc becomes really aggressive.
+		 *
+		 * The second limit is less certain. At the moment it allows
+		 * only 2 entries per bucket. We will see.
+		 */
+		if (chain_length > ip_rt_gc_elasticity) {
+			*candp = cand->u.dst.rt_next;
+			rt_free(cand);
+		}
+	}
+
+	/* Try to bind route to arp only if it is output
+	   route or unicast forwarding path.
+	 */
+	if (rt->rt_type == RTN_UNICAST || rt->fl.iif == 0) {
+		int err = arp_bind_neighbour(&rt->u.dst);
+		if (err) {
+			spin_unlock_bh(rt_hash_lock_addr(hash));
+
+			if (err != -ENOBUFS) {
+				rt_drop(rt);
+				return err;
+			}
+
+			/* Neighbour tables are full and nothing
+			   can be released. Try to shrink route cache,
+			   it is most likely it holds some neighbour records.
+			 */
+			if (attempts-- > 0) {
+				int saved_elasticity = ip_rt_gc_elasticity;
+				int saved_int = ip_rt_gc_min_interval;
+				ip_rt_gc_elasticity	= 1;
+				ip_rt_gc_min_interval	= 0;
+				rt_garbage_collect(&ipv4_dst_ops);
+				ip_rt_gc_min_interval	= saved_int;
+				ip_rt_gc_elasticity	= saved_elasticity;
+				goto restart;
+			}
+
+			if (net_ratelimit())
+				printk(KERN_WARNING "Neighbour table overflow.\n");
+			rt_drop(rt);
+			return -ENOBUFS;
+		}
+	}
+
+	rt->u.dst.rt_next = rt_hash_table[hash].chain;
+#if RT_CACHE_DEBUG >= 2
+	if (rt->u.dst.rt_next) {
+		struct rtable *trt;
+		printk(KERN_DEBUG "rt_cache @%02x: " NIPQUAD_FMT, hash,
+		       NIPQUAD(rt->rt_dst));
+		for (trt = rt->u.dst.rt_next; trt; trt = trt->u.dst.rt_next)
+			printk(" . " NIPQUAD_FMT, NIPQUAD(trt->rt_dst));
+		printk("\n");
+	}
+#endif
+	/*
+	 * Since lookup is lockfree, we must make sure
+	 * previous writes to rt are comitted to memory
+	 * before making rt visible to other CPUS.
+	 */
+	rcu_assign_pointer(rt_hash_table[hash].chain, rt);
+	spin_unlock_bh(rt_hash_lock_addr(hash));
+	*rp = rt;
+	return 0;
+}
+
+void rt_bind_peer(struct rtable *rt, int create)
+{
+	static DEFINE_SPINLOCK(rt_peer_lock);
+	struct inet_peer *peer;
+
+	peer = inet_getpeer(rt->rt_dst, create);
+
+	spin_lock_bh(&rt_peer_lock);
+	if (rt->peer == NULL) {
+		rt->peer = peer;
+		peer = NULL;
+	}
+	spin_unlock_bh(&rt_peer_lock);
+	if (peer)
+		inet_putpeer(peer);
+}
+
+/*
+ * Peer allocation may fail only in serious out-of-memory conditions.  However
+ * we still can generate some output.
+ * Random ID selection looks a bit dangerous because we have no chances to
+ * select ID being unique in a reasonable period of time.
+ * But broken packet identifier may be better than no packet at all.
+ */
+static void ip_select_fb_ident(struct iphdr *iph)
+{
+	static DEFINE_SPINLOCK(ip_fb_id_lock);
+	static u32 ip_fallback_id;
+	u32 salt;
+
+	spin_lock_bh(&ip_fb_id_lock);
+	salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
+	iph->id = htons(salt & 0xFFFF);
+	ip_fallback_id = salt;
+	spin_unlock_bh(&ip_fb_id_lock);
+}
+
+void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
+{
+	struct rtable *rt = (struct rtable *) dst;
+
+	if (rt) {
+		if (rt->peer == NULL)
+			rt_bind_peer(rt, 1);
+
+		/* If peer is attached to destination, it is never detached,
+		   so that we need not to grab a lock to dereference it.
+		 */
+		if (rt->peer) {
+			iph->id = htons(inet_getid(rt->peer, more));
+			return;
+		}
+	} else
+		printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
+		       __builtin_return_address(0));
+
+	ip_select_fb_ident(iph);
+}
+
+static void rt_del(unsigned hash, struct rtable *rt)
+{
+	struct rtable **rthp, *aux;
+
+	rthp = &rt_hash_table[hash].chain;
+	spin_lock_bh(rt_hash_lock_addr(hash));
+	ip_rt_put(rt);
+	while ((aux = *rthp) != NULL) {
+		if (aux == rt || rt_is_expired(aux)) {
+			*rthp = aux->u.dst.rt_next;
+			rt_free(aux);
+			continue;
+		}
+		rthp = &aux->u.dst.rt_next;
+	}
+	spin_unlock_bh(rt_hash_lock_addr(hash));
+}
+
+void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
+		    __be32 saddr, struct net_device *dev)
+{
+	int i, k;
+	struct in_device *in_dev = in_dev_get(dev);
+	struct rtable *rth, **rthp;
+	__be32  skeys[2] = { saddr, 0 };
+	int  ikeys[2] = { dev->ifindex, 0 };
+	struct netevent_redirect netevent;
+	struct net *net;
+
+	if (!in_dev)
+		return;
+
+	net = dev_net(dev);
+	if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev)
+	    || ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw)
+	    || ipv4_is_zeronet(new_gw))
+		goto reject_redirect;
+
+	if (!IN_DEV_SHARED_MEDIA(in_dev)) {
+		if (!inet_addr_onlink(in_dev, new_gw, old_gw))
+			goto reject_redirect;
+		if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
+			goto reject_redirect;
+	} else {
+		if (inet_addr_type(net, new_gw) != RTN_UNICAST)
+			goto reject_redirect;
+	}
+
+	for (i = 0; i < 2; i++) {
+		for (k = 0; k < 2; k++) {
+			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
+						rt_genid(net));
+
+			rthp=&rt_hash_table[hash].chain;
+
+			rcu_read_lock();
+			while ((rth = rcu_dereference(*rthp)) != NULL) {
+				struct rtable *rt;
+
+				if (rth->fl.fl4_dst != daddr ||
+				    rth->fl.fl4_src != skeys[i] ||
+				    rth->fl.oif != ikeys[k] ||
+				    rth->fl.iif != 0 ||
+				    rt_is_expired(rth) ||
+				    !net_eq(dev_net(rth->u.dst.dev), net)) {
+					rthp = &rth->u.dst.rt_next;
+					continue;
+				}
+
+				if (rth->rt_dst != daddr ||
+				    rth->rt_src != saddr ||
+				    rth->u.dst.error ||
+				    rth->rt_gateway != old_gw ||
+				    rth->u.dst.dev != dev)
+					break;
+
+				dst_hold(&rth->u.dst);
+				rcu_read_unlock();
+
+				rt = dst_alloc(&ipv4_dst_ops);
+				if (rt == NULL) {
+					ip_rt_put(rth);
+					in_dev_put(in_dev);
+					return;
+				}
+
+				/* Copy all the information. */
+				*rt = *rth;
+				INIT_RCU_HEAD(&rt->u.dst.rcu_head);
+				rt->u.dst.__use		= 1;
+				atomic_set(&rt->u.dst.__refcnt, 1);
+				rt->u.dst.child		= NULL;
+				if (rt->u.dst.dev)
+					dev_hold(rt->u.dst.dev);
+				if (rt->idev)
+					in_dev_hold(rt->idev);
+				rt->u.dst.obsolete	= 0;
+				rt->u.dst.lastuse	= jiffies;
+				rt->u.dst.path		= &rt->u.dst;
+				rt->u.dst.neighbour	= NULL;
+				rt->u.dst.hh		= NULL;
+				rt->u.dst.xfrm		= NULL;
+				rt->rt_genid		= rt_genid(net);
+				rt->rt_flags		|= RTCF_REDIRECTED;
+
+				/* Gateway is different ... */
+				rt->rt_gateway		= new_gw;
+
+				/* Redirect received -> path was valid */
+				dst_confirm(&rth->u.dst);
+
+				if (rt->peer)
+					atomic_inc(&rt->peer->refcnt);
+
+				if (arp_bind_neighbour(&rt->u.dst) ||
+				    !(rt->u.dst.neighbour->nud_state &
+					    NUD_VALID)) {
+					if (rt->u.dst.neighbour)
+						neigh_event_send(rt->u.dst.neighbour, NULL);
+					ip_rt_put(rth);
+					rt_drop(rt);
+					goto do_next;
+				}
+
+				netevent.old = &rth->u.dst;
+				netevent.new = &rt->u.dst;
+				call_netevent_notifiers(NETEVENT_REDIRECT,
+							&netevent);
+
+				rt_del(hash, rth);
+				if (!rt_intern_hash(hash, rt, &rt))
+					ip_rt_put(rt);
+				goto do_next;
+			}
+			rcu_read_unlock();
+		do_next:
+			;
+		}
+	}
+	in_dev_put(in_dev);
+	return;
+
+reject_redirect:
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+	if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
+		printk(KERN_INFO "Redirect from " NIPQUAD_FMT " on %s about "
+			NIPQUAD_FMT " ignored.\n"
+			"  Advised path = " NIPQUAD_FMT " -> " NIPQUAD_FMT "\n",
+		       NIPQUAD(old_gw), dev->name, NIPQUAD(new_gw),
+		       NIPQUAD(saddr), NIPQUAD(daddr));
+#endif
+	in_dev_put(in_dev);
+}
+
+static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
+{
+	struct rtable *rt = (struct rtable *)dst;
+	struct dst_entry *ret = dst;
+
+	if (rt) {
+		if (dst->obsolete) {
+			ip_rt_put(rt);
+			ret = NULL;
+		} else if ((rt->rt_flags & RTCF_REDIRECTED) ||
+			   rt->u.dst.expires) {
+			unsigned hash = rt_hash(rt->fl.fl4_dst, rt->fl.fl4_src,
+						rt->fl.oif,
+						rt_genid(dev_net(dst->dev)));
+#if RT_CACHE_DEBUG >= 1
+			printk(KERN_DEBUG "ipv4_negative_advice: redirect to "
+					  NIPQUAD_FMT "/%02x dropped\n",
+				NIPQUAD(rt->rt_dst), rt->fl.fl4_tos);
+#endif
+			rt_del(hash, rt);
+			ret = NULL;
+		}
+	}
+	return ret;
+}
+
+/*
+ * Algorithm:
+ *	1. The first ip_rt_redirect_number redirects are sent
+ *	   with exponential backoff, then we stop sending them at all,
+ *	   assuming that the host ignores our redirects.
+ *	2. If we did not see packets requiring redirects
+ *	   during ip_rt_redirect_silence, we assume that the host
+ *	   forgot redirected route and start to send redirects again.
+ *
+ * This algorithm is much cheaper and more intelligent than dumb load limiting
+ * in icmp.c.
+ *
+ * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
+ * and "frag. need" (breaks PMTU discovery) in icmp.c.
+ */
+
+void ip_rt_send_redirect(struct sk_buff *skb)
+{
+	struct rtable *rt = skb->rtable;
+	struct in_device *in_dev = in_dev_get(rt->u.dst.dev);
+
+	if (!in_dev)
+		return;
+
+	if (!IN_DEV_TX_REDIRECTS(in_dev))
+		goto out;
+
+	/* No redirected packets during ip_rt_redirect_silence;
+	 * reset the algorithm.
+	 */
+	if (time_after(jiffies, rt->u.dst.rate_last + ip_rt_redirect_silence))
+		rt->u.dst.rate_tokens = 0;
+
+	/* Too many ignored redirects; do not send anything
+	 * set u.dst.rate_last to the last seen redirected packet.
+	 */
+	if (rt->u.dst.rate_tokens >= ip_rt_redirect_number) {
+		rt->u.dst.rate_last = jiffies;
+		goto out;
+	}
+
+	/* Check for load limit; set rate_last to the latest sent
+	 * redirect.
+	 */
+	if (rt->u.dst.rate_tokens == 0 ||
+	    time_after(jiffies,
+		       (rt->u.dst.rate_last +
+			(ip_rt_redirect_load << rt->u.dst.rate_tokens)))) {
+		icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
+		rt->u.dst.rate_last = jiffies;
+		++rt->u.dst.rate_tokens;
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+		if (IN_DEV_LOG_MARTIANS(in_dev) &&
+		    rt->u.dst.rate_tokens == ip_rt_redirect_number &&
+		    net_ratelimit())
+			printk(KERN_WARNING "host " NIPQUAD_FMT "/if%d ignores "
+				"redirects for " NIPQUAD_FMT " to " NIPQUAD_FMT ".\n",
+				NIPQUAD(rt->rt_src), rt->rt_iif,
+				NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_gateway));
+#endif
+	}
+out:
+	in_dev_put(in_dev);
+}
+
+static int ip_error(struct sk_buff *skb)
+{
+	struct rtable *rt = skb->rtable;
+	unsigned long now;
+	int code;
+
+	switch (rt->u.dst.error) {
+		case EINVAL:
+		default:
+			goto out;
+		case EHOSTUNREACH:
+			code = ICMP_HOST_UNREACH;
+			break;
+		case ENETUNREACH:
+			code = ICMP_NET_UNREACH;
+			IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
+					IPSTATS_MIB_INNOROUTES);
+			break;
+		case EACCES:
+			code = ICMP_PKT_FILTERED;
+			break;
+	}
+
+	now = jiffies;
+	rt->u.dst.rate_tokens += now - rt->u.dst.rate_last;
+	if (rt->u.dst.rate_tokens > ip_rt_error_burst)
+		rt->u.dst.rate_tokens = ip_rt_error_burst;
+	rt->u.dst.rate_last = now;
+	if (rt->u.dst.rate_tokens >= ip_rt_error_cost) {
+		rt->u.dst.rate_tokens -= ip_rt_error_cost;
+		icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
+	}
+
+out:	kfree_skb(skb);
+	return 0;
+}
+
+/*
+ *	The last two values are not from the RFC but
+ *	are needed for AMPRnet AX.25 paths.
+ */
+
+static const unsigned short mtu_plateau[] =
+{32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
+
+static inline unsigned short guess_mtu(unsigned short old_mtu)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
+		if (old_mtu > mtu_plateau[i])
+			return mtu_plateau[i];
+	return 68;
+}
+
+unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
+				 unsigned short new_mtu,
+				 struct net_device *dev)
+{
+	int i, k;
+	unsigned short old_mtu = ntohs(iph->tot_len);
+	struct rtable *rth;
+	int  ikeys[2] = { dev->ifindex, 0 };
+	__be32  skeys[2] = { iph->saddr, 0, };
+	__be32  daddr = iph->daddr;
+	unsigned short est_mtu = 0;
+
+	if (ipv4_config.no_pmtu_disc)
+		return 0;
+
+	for (k = 0; k < 2; k++) {
+		for (i = 0; i < 2; i++) {
+			unsigned hash = rt_hash(daddr, skeys[i], ikeys[k],
+						rt_genid(net));
+
+			rcu_read_lock();
+			for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+			     rth = rcu_dereference(rth->u.dst.rt_next)) {
+				unsigned short mtu = new_mtu;
+
+				if (rth->fl.fl4_dst != daddr ||
+				    rth->fl.fl4_src != skeys[i] ||
+				    rth->rt_dst != daddr ||
+				    rth->rt_src != iph->saddr ||
+				    rth->fl.oif != ikeys[k] ||
+				    rth->fl.iif != 0 ||
+				    dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
+				    !net_eq(dev_net(rth->u.dst.dev), net) ||
+				    rt_is_expired(rth))
+					continue;
+
+				if (new_mtu < 68 || new_mtu >= old_mtu) {
+
+					/* BSD 4.2 compatibility hack :-( */
+					if (mtu == 0 &&
+					    old_mtu >= dst_mtu(&rth->u.dst) &&
+					    old_mtu >= 68 + (iph->ihl << 2))
+						old_mtu -= iph->ihl << 2;
+
+					mtu = guess_mtu(old_mtu);
+				}
+				if (mtu <= dst_mtu(&rth->u.dst)) {
+					if (mtu < dst_mtu(&rth->u.dst)) {
+						dst_confirm(&rth->u.dst);
+						if (mtu < ip_rt_min_pmtu) {
+							mtu = ip_rt_min_pmtu;
+							rth->u.dst.metrics[RTAX_LOCK-1] |=
+								(1 << RTAX_MTU);
+						}
+						rth->u.dst.metrics[RTAX_MTU-1] = mtu;
+						dst_set_expires(&rth->u.dst,
+							ip_rt_mtu_expires);
+					}
+					est_mtu = mtu;
+				}
+			}
+			rcu_read_unlock();
+		}
+	}
+	return est_mtu ? : new_mtu;
+}
+
+static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
+{
+	if (dst_mtu(dst) > mtu && mtu >= 68 &&
+	    !(dst_metric_locked(dst, RTAX_MTU))) {
+		if (mtu < ip_rt_min_pmtu) {
+			mtu = ip_rt_min_pmtu;
+			dst->metrics[RTAX_LOCK-1] |= (1 << RTAX_MTU);
+		}
+		dst->metrics[RTAX_MTU-1] = mtu;
+		dst_set_expires(dst, ip_rt_mtu_expires);
+		call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst);
+	}
+}
+
+static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
+{
+	return NULL;
+}
+
+static void ipv4_dst_destroy(struct dst_entry *dst)
+{
+	struct rtable *rt = (struct rtable *) dst;
+	struct inet_peer *peer = rt->peer;
+	struct in_device *idev = rt->idev;
+
+	if (peer) {
+		rt->peer = NULL;
+		inet_putpeer(peer);
+	}
+
+	if (idev) {
+		rt->idev = NULL;
+		in_dev_put(idev);
+	}
+}
+
+static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			    int how)
+{
+	struct rtable *rt = (struct rtable *) dst;
+	struct in_device *idev = rt->idev;
+	if (dev != dev_net(dev)->loopback_dev && idev && idev->dev == dev) {
+		struct in_device *loopback_idev =
+			in_dev_get(dev_net(dev)->loopback_dev);
+		if (loopback_idev) {
+			rt->idev = loopback_idev;
+			in_dev_put(idev);
+		}
+	}
+}
+
+static void ipv4_link_failure(struct sk_buff *skb)
+{
+	struct rtable *rt;
+
+	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
+
+	rt = skb->rtable;
+	if (rt)
+		dst_set_expires(&rt->u.dst, 0);
+}
+
+static int ip_rt_bug(struct sk_buff *skb)
+{
+	printk(KERN_DEBUG "ip_rt_bug: " NIPQUAD_FMT " -> " NIPQUAD_FMT ", %s\n",
+		NIPQUAD(ip_hdr(skb)->saddr), NIPQUAD(ip_hdr(skb)->daddr),
+		skb->dev ? skb->dev->name : "?");
+	kfree_skb(skb);
+	return 0;
+}
+
+/*
+   We do not cache source address of outgoing interface,
+   because it is used only by IP RR, TS and SRR options,
+   so that it out of fast path.
+
+   BTW remember: "addr" is allowed to be not aligned
+   in IP options!
+ */
+
+void ip_rt_get_source(u8 *addr, struct rtable *rt)
+{
+	__be32 src;
+	struct fib_result res;
+
+	if (rt->fl.iif == 0)
+		src = rt->rt_src;
+	else if (fib_lookup(dev_net(rt->u.dst.dev), &rt->fl, &res) == 0) {
+		src = FIB_RES_PREFSRC(res);
+		fib_res_put(&res);
+	} else
+		src = inet_select_addr(rt->u.dst.dev, rt->rt_gateway,
+					RT_SCOPE_UNIVERSE);
+	memcpy(addr, &src, 4);
+}
+
+#ifdef CONFIG_NET_CLS_ROUTE
+static void set_class_tag(struct rtable *rt, u32 tag)
+{
+	if (!(rt->u.dst.tclassid & 0xFFFF))
+		rt->u.dst.tclassid |= tag & 0xFFFF;
+	if (!(rt->u.dst.tclassid & 0xFFFF0000))
+		rt->u.dst.tclassid |= tag & 0xFFFF0000;
+}
+#endif
+
+static void rt_set_nexthop(struct rtable *rt, struct fib_result *res, u32 itag)
+{
+	struct fib_info *fi = res->fi;
+
+	if (fi) {
+		if (FIB_RES_GW(*res) &&
+		    FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
+			rt->rt_gateway = FIB_RES_GW(*res);
+		memcpy(rt->u.dst.metrics, fi->fib_metrics,
+		       sizeof(rt->u.dst.metrics));
+		if (fi->fib_mtu == 0) {
+			rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu;
+			if (dst_metric_locked(&rt->u.dst, RTAX_MTU) &&
+			    rt->rt_gateway != rt->rt_dst &&
+			    rt->u.dst.dev->mtu > 576)
+				rt->u.dst.metrics[RTAX_MTU-1] = 576;
+		}
+#ifdef CONFIG_NET_CLS_ROUTE
+		rt->u.dst.tclassid = FIB_RES_NH(*res).nh_tclassid;
+#endif
+	} else
+		rt->u.dst.metrics[RTAX_MTU-1]= rt->u.dst.dev->mtu;
+
+	if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0)
+		rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
+	if (dst_mtu(&rt->u.dst) > IP_MAX_MTU)
+		rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
+	if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0)
+		rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
+				       ip_rt_min_advmss);
+	if (dst_metric(&rt->u.dst, RTAX_ADVMSS) > 65535 - 40)
+		rt->u.dst.metrics[RTAX_ADVMSS-1] = 65535 - 40;
+
+#ifdef CONFIG_NET_CLS_ROUTE
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	set_class_tag(rt, fib_rules_tclass(res));
+#endif
+	set_class_tag(rt, itag);
+#endif
+	rt->rt_type = res->type;
+}
+
+static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+				u8 tos, struct net_device *dev, int our)
+{
+	unsigned hash;
+	struct rtable *rth;
+	__be32 spec_dst;
+	struct in_device *in_dev = in_dev_get(dev);
+	u32 itag = 0;
+
+	/* Primary sanity checks. */
+
+	if (in_dev == NULL)
+		return -EINVAL;
+
+	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
+	    ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
+		goto e_inval;
+
+	if (ipv4_is_zeronet(saddr)) {
+		if (!ipv4_is_local_multicast(daddr))
+			goto e_inval;
+		spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+	} else if (fib_validate_source(saddr, 0, tos, 0,
+					dev, &spec_dst, &itag) < 0)
+		goto e_inval;
+
+	rth = dst_alloc(&ipv4_dst_ops);
+	if (!rth)
+		goto e_nobufs;
+
+	rth->u.dst.output= ip_rt_bug;
+
+	atomic_set(&rth->u.dst.__refcnt, 1);
+	rth->u.dst.flags= DST_HOST;
+	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
+		rth->u.dst.flags |= DST_NOPOLICY;
+	rth->fl.fl4_dst	= daddr;
+	rth->rt_dst	= daddr;
+	rth->fl.fl4_tos	= tos;
+	rth->fl.mark    = skb->mark;
+	rth->fl.fl4_src	= saddr;
+	rth->rt_src	= saddr;
+#ifdef CONFIG_NET_CLS_ROUTE
+	rth->u.dst.tclassid = itag;
+#endif
+	rth->rt_iif	=
+	rth->fl.iif	= dev->ifindex;
+	rth->u.dst.dev	= init_net.loopback_dev;
+	dev_hold(rth->u.dst.dev);
+	rth->idev	= in_dev_get(rth->u.dst.dev);
+	rth->fl.oif	= 0;
+	rth->rt_gateway	= daddr;
+	rth->rt_spec_dst= spec_dst;
+	rth->rt_genid	= rt_genid(dev_net(dev));
+	rth->rt_flags	= RTCF_MULTICAST;
+	rth->rt_type	= RTN_MULTICAST;
+	if (our) {
+		rth->u.dst.input= ip_local_deliver;
+		rth->rt_flags |= RTCF_LOCAL;
+	}
+
+#ifdef CONFIG_IP_MROUTE
+	if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
+		rth->u.dst.input = ip_mr_input;
+#endif
+	RT_CACHE_STAT_INC(in_slow_mc);
+
+	in_dev_put(in_dev);
+	hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
+	return rt_intern_hash(hash, rth, &skb->rtable);
+
+e_nobufs:
+	in_dev_put(in_dev);
+	return -ENOBUFS;
+
+e_inval:
+	in_dev_put(in_dev);
+	return -EINVAL;
+}
+
+
+static void ip_handle_martian_source(struct net_device *dev,
+				     struct in_device *in_dev,
+				     struct sk_buff *skb,
+				     __be32 daddr,
+				     __be32 saddr)
+{
+	RT_CACHE_STAT_INC(in_martian_src);
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+	if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
+		/*
+		 *	RFC1812 recommendation, if source is martian,
+		 *	the only hint is MAC header.
+		 */
+		printk(KERN_WARNING "martian source " NIPQUAD_FMT " from "
+			NIPQUAD_FMT", on dev %s\n",
+			NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
+		if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
+			int i;
+			const unsigned char *p = skb_mac_header(skb);
+			printk(KERN_WARNING "ll header: ");
+			for (i = 0; i < dev->hard_header_len; i++, p++) {
+				printk("%02x", *p);
+				if (i < (dev->hard_header_len - 1))
+					printk(":");
+			}
+			printk("\n");
+		}
+	}
+#endif
+}
+
+static int __mkroute_input(struct sk_buff *skb,
+			   struct fib_result *res,
+			   struct in_device *in_dev,
+			   __be32 daddr, __be32 saddr, u32 tos,
+			   struct rtable **result)
+{
+
+	struct rtable *rth;
+	int err;
+	struct in_device *out_dev;
+	unsigned flags = 0;
+	__be32 spec_dst;
+	u32 itag;
+
+	/* get a working reference to the output device */
+	out_dev = in_dev_get(FIB_RES_DEV(*res));
+	if (out_dev == NULL) {
+		if (net_ratelimit())
+			printk(KERN_CRIT "Bug in ip_route_input" \
+			       "_slow(). Please, report\n");
+		return -EINVAL;
+	}
+
+
+	err = fib_validate_source(saddr, daddr, tos, FIB_RES_OIF(*res),
+				  in_dev->dev, &spec_dst, &itag);
+	if (err < 0) {
+		ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
+					 saddr);
+
+		err = -EINVAL;
+		goto cleanup;
+	}
+
+	if (err)
+		flags |= RTCF_DIRECTSRC;
+
+	if (out_dev == in_dev && err &&
+	    (IN_DEV_SHARED_MEDIA(out_dev) ||
+	     inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
+		flags |= RTCF_DOREDIRECT;
+
+	if (skb->protocol != htons(ETH_P_IP)) {
+		/* Not IP (i.e. ARP). Do not create route, if it is
+		 * invalid for proxy arp. DNAT routes are always valid.
+		 */
+		if (out_dev == in_dev) {
+			err = -EINVAL;
+			goto cleanup;
+		}
+	}
+
+
+	rth = dst_alloc(&ipv4_dst_ops);
+	if (!rth) {
+		err = -ENOBUFS;
+		goto cleanup;
+	}
+
+	atomic_set(&rth->u.dst.__refcnt, 1);
+	rth->u.dst.flags= DST_HOST;
+	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
+		rth->u.dst.flags |= DST_NOPOLICY;
+	if (IN_DEV_CONF_GET(out_dev, NOXFRM))
+		rth->u.dst.flags |= DST_NOXFRM;
+	rth->fl.fl4_dst	= daddr;
+	rth->rt_dst	= daddr;
+	rth->fl.fl4_tos	= tos;
+	rth->fl.mark    = skb->mark;
+	rth->fl.fl4_src	= saddr;
+	rth->rt_src	= saddr;
+	rth->rt_gateway	= daddr;
+	rth->rt_iif 	=
+		rth->fl.iif	= in_dev->dev->ifindex;
+	rth->u.dst.dev	= (out_dev)->dev;
+	dev_hold(rth->u.dst.dev);
+	rth->idev	= in_dev_get(rth->u.dst.dev);
+	rth->fl.oif 	= 0;
+	rth->rt_spec_dst= spec_dst;
+
+	rth->u.dst.input = ip_forward;
+	rth->u.dst.output = ip_output;
+	rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev));
+
+	rt_set_nexthop(rth, res, itag);
+
+	rth->rt_flags = flags;
+
+	*result = rth;
+	err = 0;
+ cleanup:
+	/* release the working reference to the output device */
+	in_dev_put(out_dev);
+	return err;
+}
+
+static int ip_mkroute_input(struct sk_buff *skb,
+			    struct fib_result *res,
+			    const struct flowi *fl,
+			    struct in_device *in_dev,
+			    __be32 daddr, __be32 saddr, u32 tos)
+{
+	struct rtable* rth = NULL;
+	int err;
+	unsigned hash;
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	if (res->fi && res->fi->fib_nhs > 1 && fl->oif == 0)
+		fib_select_multipath(fl, res);
+#endif
+
+	/* create a routing cache entry */
+	err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
+	if (err)
+		return err;
+
+	/* put it into the cache */
+	hash = rt_hash(daddr, saddr, fl->iif,
+		       rt_genid(dev_net(rth->u.dst.dev)));
+	return rt_intern_hash(hash, rth, &skb->rtable);
+}
+
+/*
+ *	NOTE. We drop all the packets that has local source
+ *	addresses, because every properly looped back packet
+ *	must have correct destination already attached by output routine.
+ *
+ *	Such approach solves two big problems:
+ *	1. Not simplex devices are handled properly.
+ *	2. IP spoofing attempts are filtered with 100% of guarantee.
+ */
+
+static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+			       u8 tos, struct net_device *dev)
+{
+	struct fib_result res;
+	struct in_device *in_dev = in_dev_get(dev);
+	struct flowi fl = { .nl_u = { .ip4_u =
+				      { .daddr = daddr,
+					.saddr = saddr,
+					.tos = tos,
+					.scope = RT_SCOPE_UNIVERSE,
+				      } },
+			    .mark = skb->mark,
+			    .iif = dev->ifindex };
+	unsigned	flags = 0;
+	u32		itag = 0;
+	struct rtable * rth;
+	unsigned	hash;
+	__be32		spec_dst;
+	int		err = -EINVAL;
+	int		free_res = 0;
+	struct net    * net = dev_net(dev);
+
+	/* IP on this device is disabled. */
+
+	if (!in_dev)
+		goto out;
+
+	/* Check for the most weird martians, which can be not detected
+	   by fib_lookup.
+	 */
+
+	if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
+	    ipv4_is_loopback(saddr))
+		goto martian_source;
+
+	if (daddr == htonl(0xFFFFFFFF) || (saddr == 0 && daddr == 0))
+		goto brd_input;
+
+	/* Accept zero addresses only to limited broadcast;
+	 * I even do not know to fix it or not. Waiting for complains :-)
+	 */
+	if (ipv4_is_zeronet(saddr))
+		goto martian_source;
+
+	if (ipv4_is_lbcast(daddr) || ipv4_is_zeronet(daddr) ||
+	    ipv4_is_loopback(daddr))
+		goto martian_destination;
+
+	/*
+	 *	Now we are ready to route packet.
+	 */
+	if ((err = fib_lookup(net, &fl, &res)) != 0) {
+		if (!IN_DEV_FORWARD(in_dev))
+			goto e_hostunreach;
+		goto no_route;
+	}
+	free_res = 1;
+
+	RT_CACHE_STAT_INC(in_slow_tot);
+
+	if (res.type == RTN_BROADCAST)
+		goto brd_input;
+
+	if (res.type == RTN_LOCAL) {
+		int result;
+		result = fib_validate_source(saddr, daddr, tos,
+					     net->loopback_dev->ifindex,
+					     dev, &spec_dst, &itag);
+		if (result < 0)
+			goto martian_source;
+		if (result)
+			flags |= RTCF_DIRECTSRC;
+		spec_dst = daddr;
+		goto local_input;
+	}
+
+	if (!IN_DEV_FORWARD(in_dev))
+		goto e_hostunreach;
+	if (res.type != RTN_UNICAST)
+		goto martian_destination;
+
+	err = ip_mkroute_input(skb, &res, &fl, in_dev, daddr, saddr, tos);
+done:
+	in_dev_put(in_dev);
+	if (free_res)
+		fib_res_put(&res);
+out:	return err;
+
+brd_input:
+	if (skb->protocol != htons(ETH_P_IP))
+		goto e_inval;
+
+	if (ipv4_is_zeronet(saddr))
+		spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
+	else {
+		err = fib_validate_source(saddr, 0, tos, 0, dev, &spec_dst,
+					  &itag);
+		if (err < 0)
+			goto martian_source;
+		if (err)
+			flags |= RTCF_DIRECTSRC;
+	}
+	flags |= RTCF_BROADCAST;
+	res.type = RTN_BROADCAST;
+	RT_CACHE_STAT_INC(in_brd);
+
+local_input:
+	rth = dst_alloc(&ipv4_dst_ops);
+	if (!rth)
+		goto e_nobufs;
+
+	rth->u.dst.output= ip_rt_bug;
+	rth->rt_genid = rt_genid(net);
+
+	atomic_set(&rth->u.dst.__refcnt, 1);
+	rth->u.dst.flags= DST_HOST;
+	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
+		rth->u.dst.flags |= DST_NOPOLICY;
+	rth->fl.fl4_dst	= daddr;
+	rth->rt_dst	= daddr;
+	rth->fl.fl4_tos	= tos;
+	rth->fl.mark    = skb->mark;
+	rth->fl.fl4_src	= saddr;
+	rth->rt_src	= saddr;
+#ifdef CONFIG_NET_CLS_ROUTE
+	rth->u.dst.tclassid = itag;
+#endif
+	rth->rt_iif	=
+	rth->fl.iif	= dev->ifindex;
+	rth->u.dst.dev	= net->loopback_dev;
+	dev_hold(rth->u.dst.dev);
+	rth->idev	= in_dev_get(rth->u.dst.dev);
+	rth->rt_gateway	= daddr;
+	rth->rt_spec_dst= spec_dst;
+	rth->u.dst.input= ip_local_deliver;
+	rth->rt_flags 	= flags|RTCF_LOCAL;
+	if (res.type == RTN_UNREACHABLE) {
+		rth->u.dst.input= ip_error;
+		rth->u.dst.error= -err;
+		rth->rt_flags 	&= ~RTCF_LOCAL;
+	}
+	rth->rt_type	= res.type;
+	hash = rt_hash(daddr, saddr, fl.iif, rt_genid(net));
+	err = rt_intern_hash(hash, rth, &skb->rtable);
+	goto done;
+
+no_route:
+	RT_CACHE_STAT_INC(in_no_route);
+	spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
+	res.type = RTN_UNREACHABLE;
+	if (err == -ESRCH)
+		err = -ENETUNREACH;
+	goto local_input;
+
+	/*
+	 *	Do not cache martian addresses: they should be logged (RFC1812)
+	 */
+martian_destination:
+	RT_CACHE_STAT_INC(in_martian_dst);
+#ifdef CONFIG_IP_ROUTE_VERBOSE
+	if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
+		printk(KERN_WARNING "martian destination " NIPQUAD_FMT " from "
+			NIPQUAD_FMT ", dev %s\n",
+			NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
+#endif
+
+e_hostunreach:
+	err = -EHOSTUNREACH;
+	goto done;
+
+e_inval:
+	err = -EINVAL;
+	goto done;
+
+e_nobufs:
+	err = -ENOBUFS;
+	goto done;
+
+martian_source:
+	ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
+	goto e_inval;
+}
+
+int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
+		   u8 tos, struct net_device *dev)
+{
+	struct rtable * rth;
+	unsigned	hash;
+	int iif = dev->ifindex;
+	struct net *net;
+
+	net = dev_net(dev);
+	tos &= IPTOS_RT_MASK;
+	hash = rt_hash(daddr, saddr, iif, rt_genid(net));
+
+	rcu_read_lock();
+	for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+	     rth = rcu_dereference(rth->u.dst.rt_next)) {
+		if (((rth->fl.fl4_dst ^ daddr) |
+		     (rth->fl.fl4_src ^ saddr) |
+		     (rth->fl.iif ^ iif) |
+		     rth->fl.oif |
+		     (rth->fl.fl4_tos ^ tos)) == 0 &&
+		    rth->fl.mark == skb->mark &&
+		    net_eq(dev_net(rth->u.dst.dev), net) &&
+		    !rt_is_expired(rth)) {
+			dst_use(&rth->u.dst, jiffies);
+			RT_CACHE_STAT_INC(in_hit);
+			rcu_read_unlock();
+			skb->rtable = rth;
+			return 0;
+		}
+		RT_CACHE_STAT_INC(in_hlist_search);
+	}
+	rcu_read_unlock();
+
+	/* Multicast recognition logic is moved from route cache to here.
+	   The problem was that too many Ethernet cards have broken/missing
+	   hardware multicast filters :-( As result the host on multicasting
+	   network acquires a lot of useless route cache entries, sort of
+	   SDR messages from all the world. Now we try to get rid of them.
+	   Really, provided software IP multicast filter is organized
+	   reasonably (at least, hashed), it does not result in a slowdown
+	   comparing with route cache reject entries.
+	   Note, that multicast routers are not affected, because
+	   route cache entry is created eventually.
+	 */
+	if (ipv4_is_multicast(daddr)) {
+		struct in_device *in_dev;
+
+		rcu_read_lock();
+		if ((in_dev = __in_dev_get_rcu(dev)) != NULL) {
+			int our = ip_check_mc(in_dev, daddr, saddr,
+				ip_hdr(skb)->protocol);
+			if (our
+#ifdef CONFIG_IP_MROUTE
+			    || (!ipv4_is_local_multicast(daddr) &&
+				IN_DEV_MFORWARD(in_dev))
+#endif
+			    ) {
+				rcu_read_unlock();
+				return ip_route_input_mc(skb, daddr, saddr,
+							 tos, dev, our);
+			}
+		}
+		rcu_read_unlock();
+		return -EINVAL;
+	}
+	return ip_route_input_slow(skb, daddr, saddr, tos, dev);
+}
+
+static int __mkroute_output(struct rtable **result,
+			    struct fib_result *res,
+			    const struct flowi *fl,
+			    const struct flowi *oldflp,
+			    struct net_device *dev_out,
+			    unsigned flags)
+{
+	struct rtable *rth;
+	struct in_device *in_dev;
+	u32 tos = RT_FL_TOS(oldflp);
+	int err = 0;
+
+	if (ipv4_is_loopback(fl->fl4_src) && !(dev_out->flags&IFF_LOOPBACK))
+		return -EINVAL;
+
+	if (fl->fl4_dst == htonl(0xFFFFFFFF))
+		res->type = RTN_BROADCAST;
+	else if (ipv4_is_multicast(fl->fl4_dst))
+		res->type = RTN_MULTICAST;
+	else if (ipv4_is_lbcast(fl->fl4_dst) || ipv4_is_zeronet(fl->fl4_dst))
+		return -EINVAL;
+
+	if (dev_out->flags & IFF_LOOPBACK)
+		flags |= RTCF_LOCAL;
+
+	/* get work reference to inet device */
+	in_dev = in_dev_get(dev_out);
+	if (!in_dev)
+		return -EINVAL;
+
+	if (res->type == RTN_BROADCAST) {
+		flags |= RTCF_BROADCAST | RTCF_LOCAL;
+		if (res->fi) {
+			fib_info_put(res->fi);
+			res->fi = NULL;
+		}
+	} else if (res->type == RTN_MULTICAST) {
+		flags |= RTCF_MULTICAST|RTCF_LOCAL;
+		if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,
+				 oldflp->proto))
+			flags &= ~RTCF_LOCAL;
+		/* If multicast route do not exist use
+		   default one, but do not gateway in this case.
+		   Yes, it is hack.
+		 */
+		if (res->fi && res->prefixlen < 4) {
+			fib_info_put(res->fi);
+			res->fi = NULL;
+		}
+	}
+
+
+	rth = dst_alloc(&ipv4_dst_ops);
+	if (!rth) {
+		err = -ENOBUFS;
+		goto cleanup;
+	}
+
+	atomic_set(&rth->u.dst.__refcnt, 1);
+	rth->u.dst.flags= DST_HOST;
+	if (IN_DEV_CONF_GET(in_dev, NOXFRM))
+		rth->u.dst.flags |= DST_NOXFRM;
+	if (IN_DEV_CONF_GET(in_dev, NOPOLICY))
+		rth->u.dst.flags |= DST_NOPOLICY;
+
+	rth->fl.fl4_dst	= oldflp->fl4_dst;
+	rth->fl.fl4_tos	= tos;
+	rth->fl.fl4_src	= oldflp->fl4_src;
+	rth->fl.oif	= oldflp->oif;
+	rth->fl.mark    = oldflp->mark;
+	rth->rt_dst	= fl->fl4_dst;
+	rth->rt_src	= fl->fl4_src;
+	rth->rt_iif	= oldflp->oif ? : dev_out->ifindex;
+	/* get references to the devices that are to be hold by the routing
+	   cache entry */
+	rth->u.dst.dev	= dev_out;
+	dev_hold(dev_out);
+	rth->idev	= in_dev_get(dev_out);
+	rth->rt_gateway = fl->fl4_dst;
+	rth->rt_spec_dst= fl->fl4_src;
+
+	rth->u.dst.output=ip_output;
+	rth->rt_genid = rt_genid(dev_net(dev_out));
+
+	RT_CACHE_STAT_INC(out_slow_tot);
+
+	if (flags & RTCF_LOCAL) {
+		rth->u.dst.input = ip_local_deliver;
+		rth->rt_spec_dst = fl->fl4_dst;
+	}
+	if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
+		rth->rt_spec_dst = fl->fl4_src;
+		if (flags & RTCF_LOCAL &&
+		    !(dev_out->flags & IFF_LOOPBACK)) {
+			rth->u.dst.output = ip_mc_output;
+			RT_CACHE_STAT_INC(out_slow_mc);
+		}
+#ifdef CONFIG_IP_MROUTE
+		if (res->type == RTN_MULTICAST) {
+			if (IN_DEV_MFORWARD(in_dev) &&
+			    !ipv4_is_local_multicast(oldflp->fl4_dst)) {
+				rth->u.dst.input = ip_mr_input;
+				rth->u.dst.output = ip_mc_output;
+			}
+		}
+#endif
+	}
+
+	rt_set_nexthop(rth, res, 0);
+
+	rth->rt_flags = flags;
+
+	*result = rth;
+ cleanup:
+	/* release work reference to inet device */
+	in_dev_put(in_dev);
+
+	return err;
+}
+
+static int ip_mkroute_output(struct rtable **rp,
+			     struct fib_result *res,
+			     const struct flowi *fl,
+			     const struct flowi *oldflp,
+			     struct net_device *dev_out,
+			     unsigned flags)
+{
+	struct rtable *rth = NULL;
+	int err = __mkroute_output(&rth, res, fl, oldflp, dev_out, flags);
+	unsigned hash;
+	if (err == 0) {
+		hash = rt_hash(oldflp->fl4_dst, oldflp->fl4_src, oldflp->oif,
+			       rt_genid(dev_net(dev_out)));
+		err = rt_intern_hash(hash, rth, rp);
+	}
+
+	return err;
+}
+
+/*
+ * Major route resolver routine.
+ */
+
+static int ip_route_output_slow(struct net *net, struct rtable **rp,
+				const struct flowi *oldflp)
+{
+	u32 tos	= RT_FL_TOS(oldflp);
+	struct flowi fl = { .nl_u = { .ip4_u =
+				      { .daddr = oldflp->fl4_dst,
+					.saddr = oldflp->fl4_src,
+					.tos = tos & IPTOS_RT_MASK,
+					.scope = ((tos & RTO_ONLINK) ?
+						  RT_SCOPE_LINK :
+						  RT_SCOPE_UNIVERSE),
+				      } },
+			    .mark = oldflp->mark,
+			    .iif = net->loopback_dev->ifindex,
+			    .oif = oldflp->oif };
+	struct fib_result res;
+	unsigned flags = 0;
+	struct net_device *dev_out = NULL;
+	int free_res = 0;
+	int err;
+
+
+	res.fi		= NULL;
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+	res.r		= NULL;
+#endif
+
+	if (oldflp->fl4_src) {
+		err = -EINVAL;
+		if (ipv4_is_multicast(oldflp->fl4_src) ||
+		    ipv4_is_lbcast(oldflp->fl4_src) ||
+		    ipv4_is_zeronet(oldflp->fl4_src))
+			goto out;
+
+		/* I removed check for oif == dev_out->oif here.
+		   It was wrong for two reasons:
+		   1. ip_dev_find(net, saddr) can return wrong iface, if saddr
+		      is assigned to multiple interfaces.
+		   2. Moreover, we are allowed to send packets with saddr
+		      of another iface. --ANK
+		 */
+
+		if (oldflp->oif == 0
+		    && (ipv4_is_multicast(oldflp->fl4_dst) ||
+			oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
+			/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+			dev_out = ip_dev_find(net, oldflp->fl4_src);
+			if (dev_out == NULL)
+				goto out;
+
+			/* Special hack: user can direct multicasts
+			   and limited broadcast via necessary interface
+			   without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
+			   This hack is not just for fun, it allows
+			   vic,vat and friends to work.
+			   They bind socket to loopback, set ttl to zero
+			   and expect that it will work.
+			   From the viewpoint of routing cache they are broken,
+			   because we are not allowed to build multicast path
+			   with loopback source addr (look, routing cache
+			   cannot know, that ttl is zero, so that packet
+			   will not leave this host and route is valid).
+			   Luckily, this hack is good workaround.
+			 */
+
+			fl.oif = dev_out->ifindex;
+			goto make_route;
+		}
+
+		if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
+			/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+			dev_out = ip_dev_find(net, oldflp->fl4_src);
+			if (dev_out == NULL)
+				goto out;
+			dev_put(dev_out);
+			dev_out = NULL;
+		}
+	}
+
+
+	if (oldflp->oif) {
+		dev_out = dev_get_by_index(net, oldflp->oif);
+		err = -ENODEV;
+		if (dev_out == NULL)
+			goto out;
+
+		/* RACE: Check return value of inet_select_addr instead. */
+		if (__in_dev_get_rtnl(dev_out) == NULL) {
+			dev_put(dev_out);
+			goto out;	/* Wrong error code */
+		}
+
+		if (ipv4_is_local_multicast(oldflp->fl4_dst) ||
+		    oldflp->fl4_dst == htonl(0xFFFFFFFF)) {
+			if (!fl.fl4_src)
+				fl.fl4_src = inet_select_addr(dev_out, 0,
+							      RT_SCOPE_LINK);
+			goto make_route;
+		}
+		if (!fl.fl4_src) {
+			if (ipv4_is_multicast(oldflp->fl4_dst))
+				fl.fl4_src = inet_select_addr(dev_out, 0,
+							      fl.fl4_scope);
+			else if (!oldflp->fl4_dst)
+				fl.fl4_src = inet_select_addr(dev_out, 0,
+							      RT_SCOPE_HOST);
+		}
+	}
+
+	if (!fl.fl4_dst) {
+		fl.fl4_dst = fl.fl4_src;
+		if (!fl.fl4_dst)
+			fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
+		if (dev_out)
+			dev_put(dev_out);
+		dev_out = net->loopback_dev;
+		dev_hold(dev_out);
+		fl.oif = net->loopback_dev->ifindex;
+		res.type = RTN_LOCAL;
+		flags |= RTCF_LOCAL;
+		goto make_route;
+	}
+
+	if (fib_lookup(net, &fl, &res)) {
+		res.fi = NULL;
+		if (oldflp->oif) {
+			/* Apparently, routing tables are wrong. Assume,
+			   that the destination is on link.
+
+			   WHY? DW.
+			   Because we are allowed to send to iface
+			   even if it has NO routes and NO assigned
+			   addresses. When oif is specified, routing
+			   tables are looked up with only one purpose:
+			   to catch if destination is gatewayed, rather than
+			   direct. Moreover, if MSG_DONTROUTE is set,
+			   we send packet, ignoring both routing tables
+			   and ifaddr state. --ANK
+
+
+			   We could make it even if oif is unknown,
+			   likely IPv6, but we do not.
+			 */
+
+			if (fl.fl4_src == 0)
+				fl.fl4_src = inet_select_addr(dev_out, 0,
+							      RT_SCOPE_LINK);
+			res.type = RTN_UNICAST;
+			goto make_route;
+		}
+		if (dev_out)
+			dev_put(dev_out);
+		err = -ENETUNREACH;
+		goto out;
+	}
+	free_res = 1;
+
+	if (res.type == RTN_LOCAL) {
+		if (!fl.fl4_src)
+			fl.fl4_src = fl.fl4_dst;
+		if (dev_out)
+			dev_put(dev_out);
+		dev_out = net->loopback_dev;
+		dev_hold(dev_out);
+		fl.oif = dev_out->ifindex;
+		if (res.fi)
+			fib_info_put(res.fi);
+		res.fi = NULL;
+		flags |= RTCF_LOCAL;
+		goto make_route;
+	}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+	if (res.fi->fib_nhs > 1 && fl.oif == 0)
+		fib_select_multipath(&fl, &res);
+	else
+#endif
+	if (!res.prefixlen && res.type == RTN_UNICAST && !fl.oif)
+		fib_select_default(net, &fl, &res);
+
+	if (!fl.fl4_src)
+		fl.fl4_src = FIB_RES_PREFSRC(res);
+
+	if (dev_out)
+		dev_put(dev_out);
+	dev_out = FIB_RES_DEV(res);
+	dev_hold(dev_out);
+	fl.oif = dev_out->ifindex;
+
+
+make_route:
+	err = ip_mkroute_output(rp, &res, &fl, oldflp, dev_out, flags);
+
+
+	if (free_res)
+		fib_res_put(&res);
+	if (dev_out)
+		dev_put(dev_out);
+out:	return err;
+}
+
+int __ip_route_output_key(struct net *net, struct rtable **rp,
+			  const struct flowi *flp)
+{
+	unsigned hash;
+	struct rtable *rth;
+
+	hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
+
+	rcu_read_lock_bh();
+	for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
+		rth = rcu_dereference(rth->u.dst.rt_next)) {
+		if (rth->fl.fl4_dst == flp->fl4_dst &&
+		    rth->fl.fl4_src == flp->fl4_src &&
+		    rth->fl.iif == 0 &&
+		    rth->fl.oif == flp->oif &&
+		    rth->fl.mark == flp->mark &&
+		    !((rth->fl.fl4_tos ^ flp->fl4_tos) &
+			    (IPTOS_RT_MASK | RTO_ONLINK)) &&
+		    net_eq(dev_net(rth->u.dst.dev), net) &&
+		    !rt_is_expired(rth)) {
+			dst_use(&rth->u.dst, jiffies);
+			RT_CACHE_STAT_INC(out_hit);
+			rcu_read_unlock_bh();
+			*rp = rth;
+			return 0;
+		}
+		RT_CACHE_STAT_INC(out_hlist_search);
+	}
+	rcu_read_unlock_bh();
+
+	return ip_route_output_slow(net, rp, flp);
+}
+
+EXPORT_SYMBOL_GPL(__ip_route_output_key);
+
+static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
+{
+}
+
+static struct dst_ops ipv4_dst_blackhole_ops = {
+	.family			=	AF_INET,
+	.protocol		=	__constant_htons(ETH_P_IP),
+	.destroy		=	ipv4_dst_destroy,
+	.check			=	ipv4_dst_check,
+	.update_pmtu		=	ipv4_rt_blackhole_update_pmtu,
+	.entry_size		=	sizeof(struct rtable),
+	.entries		=	ATOMIC_INIT(0),
+};
+
+
+static int ipv4_dst_blackhole(struct net *net, struct rtable **rp, struct flowi *flp)
+{
+	struct rtable *ort = *rp;
+	struct rtable *rt = (struct rtable *)
+		dst_alloc(&ipv4_dst_blackhole_ops);
+
+	if (rt) {
+		struct dst_entry *new = &rt->u.dst;
+
+		atomic_set(&new->__refcnt, 1);
+		new->__use = 1;
+		new->input = dst_discard;
+		new->output = dst_discard;
+		memcpy(new->metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32));
+
+		new->dev = ort->u.dst.dev;
+		if (new->dev)
+			dev_hold(new->dev);
+
+		rt->fl = ort->fl;
+
+		rt->idev = ort->idev;
+		if (rt->idev)
+			in_dev_hold(rt->idev);
+		rt->rt_genid = rt_genid(net);
+		rt->rt_flags = ort->rt_flags;
+		rt->rt_type = ort->rt_type;
+		rt->rt_dst = ort->rt_dst;
+		rt->rt_src = ort->rt_src;
+		rt->rt_iif = ort->rt_iif;
+		rt->rt_gateway = ort->rt_gateway;
+		rt->rt_spec_dst = ort->rt_spec_dst;
+		rt->peer = ort->peer;
+		if (rt->peer)
+			atomic_inc(&rt->peer->refcnt);
+
+		dst_free(new);
+	}
+
+	dst_release(&(*rp)->u.dst);
+	*rp = rt;
+	return (rt ? 0 : -ENOMEM);
+}
+
+int ip_route_output_flow(struct net *net, struct rtable **rp, struct flowi *flp,
+			 struct sock *sk, int flags)
+{
+	int err;
+
+	if ((err = __ip_route_output_key(net, rp, flp)) != 0)
+		return err;
+
+	if (flp->proto) {
+		if (!flp->fl4_src)
+			flp->fl4_src = (*rp)->rt_src;
+		if (!flp->fl4_dst)
+			flp->fl4_dst = (*rp)->rt_dst;
+		err = __xfrm_lookup((struct dst_entry **)rp, flp, sk,
+				    flags ? XFRM_LOOKUP_WAIT : 0);
+		if (err == -EREMOTE)
+			err = ipv4_dst_blackhole(net, rp, flp);
+
+		return err;
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(ip_route_output_flow);
+
+int ip_route_output_key(struct net *net, struct rtable **rp, struct flowi *flp)
+{
+	return ip_route_output_flow(net, rp, flp, NULL, 0);
+}
+
+static int rt_fill_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
+			int nowait, unsigned int flags)
+{
+	struct rtable *rt = skb->rtable;
+	struct rtmsg *r;
+	struct nlmsghdr *nlh;
+	long expires;
+	u32 id = 0, ts = 0, tsage = 0, error;
+
+	nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
+	if (nlh == NULL)
+		return -EMSGSIZE;
+
+	r = nlmsg_data(nlh);
+	r->rtm_family	 = AF_INET;
+	r->rtm_dst_len	= 32;
+	r->rtm_src_len	= 0;
+	r->rtm_tos	= rt->fl.fl4_tos;
+	r->rtm_table	= RT_TABLE_MAIN;
+	NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
+	r->rtm_type	= rt->rt_type;
+	r->rtm_scope	= RT_SCOPE_UNIVERSE;
+	r->rtm_protocol = RTPROT_UNSPEC;
+	r->rtm_flags	= (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
+	if (rt->rt_flags & RTCF_NOTIFY)
+		r->rtm_flags |= RTM_F_NOTIFY;
+
+	NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
+
+	if (rt->fl.fl4_src) {
+		r->rtm_src_len = 32;
+		NLA_PUT_BE32(skb, RTA_SRC, rt->fl.fl4_src);
+	}
+	if (rt->u.dst.dev)
+		NLA_PUT_U32(skb, RTA_OIF, rt->u.dst.dev->ifindex);
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (rt->u.dst.tclassid)
+		NLA_PUT_U32(skb, RTA_FLOW, rt->u.dst.tclassid);
+#endif
+	if (rt->fl.iif)
+		NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
+	else if (rt->rt_src != rt->fl.fl4_src)
+		NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
+
+	if (rt->rt_dst != rt->rt_gateway)
+		NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
+
+	if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0)
+		goto nla_put_failure;
+
+	error = rt->u.dst.error;
+	expires = rt->u.dst.expires ? rt->u.dst.expires - jiffies : 0;
+	if (rt->peer) {
+		id = rt->peer->ip_id_count;
+		if (rt->peer->tcp_ts_stamp) {
+			ts = rt->peer->tcp_ts;
+			tsage = get_seconds() - rt->peer->tcp_ts_stamp;
+		}
+	}
+
+	if (rt->fl.iif) {
+#ifdef CONFIG_IP_MROUTE
+		__be32 dst = rt->rt_dst;
+
+		if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
+		    IPV4_DEVCONF_ALL(&init_net, MC_FORWARDING)) {
+			int err = ipmr_get_route(skb, r, nowait);
+			if (err <= 0) {
+				if (!nowait) {
+					if (err == 0)
+						return 0;
+					goto nla_put_failure;
+				} else {
+					if (err == -EMSGSIZE)
+						goto nla_put_failure;
+					error = err;
+				}
+			}
+		} else
+#endif
+			NLA_PUT_U32(skb, RTA_IIF, rt->fl.iif);
+	}
+
+	if (rtnl_put_cacheinfo(skb, &rt->u.dst, id, ts, tsage,
+			       expires, error) < 0)
+		goto nla_put_failure;
+
+	return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct rtmsg *rtm;
+	struct nlattr *tb[RTA_MAX+1];
+	struct rtable *rt = NULL;
+	__be32 dst = 0;
+	__be32 src = 0;
+	u32 iif;
+	int err;
+	struct sk_buff *skb;
+
+	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
+	if (err < 0)
+		goto errout;
+
+	rtm = nlmsg_data(nlh);
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (skb == NULL) {
+		err = -ENOBUFS;
+		goto errout;
+	}
+
+	/* Reserve room for dummy headers, this skb can pass
+	   through good chunk of routing engine.
+	 */
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+
+	/* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
+	ip_hdr(skb)->protocol = IPPROTO_ICMP;
+	skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
+
+	src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
+	dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
+	iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
+
+	if (iif) {
+		struct net_device *dev;
+
+		dev = __dev_get_by_index(net, iif);
+		if (dev == NULL) {
+			err = -ENODEV;
+			goto errout_free;
+		}
+
+		skb->protocol	= htons(ETH_P_IP);
+		skb->dev	= dev;
+		local_bh_disable();
+		err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
+		local_bh_enable();
+
+		rt = skb->rtable;
+		if (err == 0 && rt->u.dst.error)
+			err = -rt->u.dst.error;
+	} else {
+		struct flowi fl = {
+			.nl_u = {
+				.ip4_u = {
+					.daddr = dst,
+					.saddr = src,
+					.tos = rtm->rtm_tos,
+				},
+			},
+			.oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
+		};
+		err = ip_route_output_key(net, &rt, &fl);
+	}
+
+	if (err)
+		goto errout_free;
+
+	skb->rtable = rt;
+	if (rtm->rtm_flags & RTM_F_NOTIFY)
+		rt->rt_flags |= RTCF_NOTIFY;
+
+	err = rt_fill_info(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+			   RTM_NEWROUTE, 0, 0);
+	if (err <= 0)
+		goto errout_free;
+
+	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
+errout:
+	return err;
+
+errout_free:
+	kfree_skb(skb);
+	goto errout;
+}
+
+int ip_rt_dump(struct sk_buff *skb,  struct netlink_callback *cb)
+{
+	struct rtable *rt;
+	int h, s_h;
+	int idx, s_idx;
+	struct net *net;
+
+	net = sock_net(skb->sk);
+
+	s_h = cb->args[0];
+	if (s_h < 0)
+		s_h = 0;
+	s_idx = idx = cb->args[1];
+	for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
+		if (!rt_hash_table[h].chain)
+			continue;
+		rcu_read_lock_bh();
+		for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
+		     rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
+			if (!net_eq(dev_net(rt->u.dst.dev), net) || idx < s_idx)
+				continue;
+			if (rt_is_expired(rt))
+				continue;
+			skb->dst = dst_clone(&rt->u.dst);
+			if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
+					 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
+					 1, NLM_F_MULTI) <= 0) {
+				dst_release(xchg(&skb->dst, NULL));
+				rcu_read_unlock_bh();
+				goto done;
+			}
+			dst_release(xchg(&skb->dst, NULL));
+		}
+		rcu_read_unlock_bh();
+	}
+
+done:
+	cb->args[0] = h;
+	cb->args[1] = idx;
+	return skb->len;
+}
+
+void ip_rt_multicast_event(struct in_device *in_dev)
+{
+	rt_cache_flush(dev_net(in_dev->dev), 0);
+}
+
+#ifdef CONFIG_SYSCTL
+static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
+					struct file *filp, void __user *buffer,
+					size_t *lenp, loff_t *ppos)
+{
+	if (write) {
+		int flush_delay;
+		ctl_table ctl;
+		struct net *net;
+
+		memcpy(&ctl, __ctl, sizeof(ctl));
+		ctl.data = &flush_delay;
+		proc_dointvec(&ctl, write, filp, buffer, lenp, ppos);
+
+		net = (struct net *)__ctl->extra1;
+		rt_cache_flush(net, flush_delay);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
+						void __user *oldval,
+						size_t __user *oldlenp,
+						void __user *newval,
+						size_t newlen)
+{
+	int delay;
+	struct net *net;
+	if (newlen != sizeof(int))
+		return -EINVAL;
+	if (get_user(delay, (int __user *)newval))
+		return -EFAULT;
+	net = (struct net *)table->extra1;
+	rt_cache_flush(net, delay);
+	return 0;
+}
+
+static void rt_secret_reschedule(int old)
+{
+	struct net *net;
+	int new = ip_rt_secret_interval;
+	int diff = new - old;
+
+	if (!diff)
+		return;
+
+	rtnl_lock();
+	for_each_net(net) {
+		int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
+
+		if (!new)
+			continue;
+
+		if (deleted) {
+			long time = net->ipv4.rt_secret_timer.expires - jiffies;
+
+			if (time <= 0 || (time += diff) <= 0)
+				time = 0;
+
+			net->ipv4.rt_secret_timer.expires = time;
+		} else
+			net->ipv4.rt_secret_timer.expires = new;
+
+		net->ipv4.rt_secret_timer.expires += jiffies;
+		add_timer(&net->ipv4.rt_secret_timer);
+	}
+	rtnl_unlock();
+}
+
+static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
+					  struct file *filp,
+					  void __user *buffer, size_t *lenp,
+					  loff_t *ppos)
+{
+	int old = ip_rt_secret_interval;
+	int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
+
+	rt_secret_reschedule(old);
+
+	return ret;
+}
+
+static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
+						   void __user *oldval,
+						   size_t __user *oldlenp,
+						   void __user *newval,
+						   size_t newlen)
+{
+	int old = ip_rt_secret_interval;
+	int ret = sysctl_jiffies(table, oldval, oldlenp, newval, newlen);
+
+	rt_secret_reschedule(old);
+
+	return ret;
+}
+
+static ctl_table ipv4_route_table[] = {
+	{
+		.ctl_name	= NET_IPV4_ROUTE_GC_THRESH,
+		.procname	= "gc_thresh",
+		.data		= &ipv4_dst_ops.gc_thresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_MAX_SIZE,
+		.procname	= "max_size",
+		.data		= &ip_rt_max_size,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		/*  Deprecated. Use gc_min_interval_ms */
+
+		.ctl_name	= NET_IPV4_ROUTE_GC_MIN_INTERVAL,
+		.procname	= "gc_min_interval",
+		.data		= &ip_rt_gc_min_interval,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_GC_MIN_INTERVAL_MS,
+		.procname	= "gc_min_interval_ms",
+		.data		= &ip_rt_gc_min_interval,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_ms_jiffies,
+		.strategy	= &sysctl_ms_jiffies,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_GC_TIMEOUT,
+		.procname	= "gc_timeout",
+		.data		= &ip_rt_gc_timeout,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_GC_INTERVAL,
+		.procname	= "gc_interval",
+		.data		= &ip_rt_gc_interval,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_REDIRECT_LOAD,
+		.procname	= "redirect_load",
+		.data		= &ip_rt_redirect_load,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_REDIRECT_NUMBER,
+		.procname	= "redirect_number",
+		.data		= &ip_rt_redirect_number,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_REDIRECT_SILENCE,
+		.procname	= "redirect_silence",
+		.data		= &ip_rt_redirect_silence,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_ERROR_COST,
+		.procname	= "error_cost",
+		.data		= &ip_rt_error_cost,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_ERROR_BURST,
+		.procname	= "error_burst",
+		.data		= &ip_rt_error_burst,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_GC_ELASTICITY,
+		.procname	= "gc_elasticity",
+		.data		= &ip_rt_gc_elasticity,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_MTU_EXPIRES,
+		.procname	= "mtu_expires",
+		.data		= &ip_rt_mtu_expires,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_MIN_PMTU,
+		.procname	= "min_pmtu",
+		.data		= &ip_rt_min_pmtu,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_MIN_ADVMSS,
+		.procname	= "min_adv_mss",
+		.data		= &ip_rt_min_advmss,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_ROUTE_SECRET_INTERVAL,
+		.procname	= "secret_interval",
+		.data		= &ip_rt_secret_interval,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &ipv4_sysctl_rt_secret_interval,
+		.strategy	= &ipv4_sysctl_rt_secret_interval_strategy,
+	},
+	{ .ctl_name = 0 }
+};
+
+static struct ctl_table empty[1];
+
+static struct ctl_table ipv4_skeleton[] =
+{
+	{ .procname = "route", .ctl_name = NET_IPV4_ROUTE,
+	  .mode = 0555, .child = ipv4_route_table},
+	{ .procname = "neigh", .ctl_name = NET_IPV4_NEIGH,
+	  .mode = 0555, .child = empty},
+	{ }
+};
+
+static __net_initdata struct ctl_path ipv4_path[] = {
+	{ .procname = "net", .ctl_name = CTL_NET, },
+	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
+	{ },
+};
+
+static struct ctl_table ipv4_route_flush_table[] = {
+	{
+		.ctl_name 	= NET_IPV4_ROUTE_FLUSH,
+		.procname	= "flush",
+		.maxlen		= sizeof(int),
+		.mode		= 0200,
+		.proc_handler	= &ipv4_sysctl_rtcache_flush,
+		.strategy	= &ipv4_sysctl_rtcache_flush_strategy,
+	},
+	{ .ctl_name = 0 },
+};
+
+static __net_initdata struct ctl_path ipv4_route_path[] = {
+	{ .procname = "net", .ctl_name = CTL_NET, },
+	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
+	{ .procname = "route", .ctl_name = NET_IPV4_ROUTE, },
+	{ },
+};
+
+static __net_init int sysctl_route_net_init(struct net *net)
+{
+	struct ctl_table *tbl;
+
+	tbl = ipv4_route_flush_table;
+	if (net != &init_net) {
+		tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
+		if (tbl == NULL)
+			goto err_dup;
+	}
+	tbl[0].extra1 = net;
+
+	net->ipv4.route_hdr =
+		register_net_sysctl_table(net, ipv4_route_path, tbl);
+	if (net->ipv4.route_hdr == NULL)
+		goto err_reg;
+	return 0;
+
+err_reg:
+	if (tbl != ipv4_route_flush_table)
+		kfree(tbl);
+err_dup:
+	return -ENOMEM;
+}
+
+static __net_exit void sysctl_route_net_exit(struct net *net)
+{
+	struct ctl_table *tbl;
+
+	tbl = net->ipv4.route_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->ipv4.route_hdr);
+	BUG_ON(tbl == ipv4_route_flush_table);
+	kfree(tbl);
+}
+
+static __net_initdata struct pernet_operations sysctl_route_ops = {
+	.init = sysctl_route_net_init,
+	.exit = sysctl_route_net_exit,
+};
+#endif
+
+
+static __net_init int rt_secret_timer_init(struct net *net)
+{
+	atomic_set(&net->ipv4.rt_genid,
+			(int) ((num_physpages ^ (num_physpages>>8)) ^
+			(jiffies ^ (jiffies >> 7))));
+
+	net->ipv4.rt_secret_timer.function = rt_secret_rebuild;
+	net->ipv4.rt_secret_timer.data = (unsigned long)net;
+	init_timer_deferrable(&net->ipv4.rt_secret_timer);
+
+	if (ip_rt_secret_interval) {
+		net->ipv4.rt_secret_timer.expires =
+			jiffies + net_random() % ip_rt_secret_interval +
+			ip_rt_secret_interval;
+		add_timer(&net->ipv4.rt_secret_timer);
+	}
+	return 0;
+}
+
+static __net_exit void rt_secret_timer_exit(struct net *net)
+{
+	del_timer_sync(&net->ipv4.rt_secret_timer);
+}
+
+static __net_initdata struct pernet_operations rt_secret_timer_ops = {
+	.init = rt_secret_timer_init,
+	.exit = rt_secret_timer_exit,
+};
+
+
+#ifdef CONFIG_NET_CLS_ROUTE
+struct ip_rt_acct *ip_rt_acct __read_mostly;
+#endif /* CONFIG_NET_CLS_ROUTE */
+
+static __initdata unsigned long rhash_entries;
+static int __init set_rhash_entries(char *str)
+{
+	if (!str)
+		return 0;
+	rhash_entries = simple_strtoul(str, &str, 0);
+	return 1;
+}
+__setup("rhash_entries=", set_rhash_entries);
+
+int __init ip_rt_init(void)
+{
+	int rc = 0;
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct));
+	if (!ip_rt_acct)
+		panic("IP: failed to allocate ip_rt_acct\n");
+#endif
+
+	ipv4_dst_ops.kmem_cachep =
+		kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
+				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+
+	ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
+
+	rt_hash_table = (struct rt_hash_bucket *)
+		alloc_large_system_hash("IP route cache",
+					sizeof(struct rt_hash_bucket),
+					rhash_entries,
+					(num_physpages >= 128 * 1024) ?
+					15 : 17,
+					0,
+					&rt_hash_log,
+					&rt_hash_mask,
+					0);
+	memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
+	rt_hash_lock_init();
+
+	ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
+	ip_rt_max_size = (rt_hash_mask + 1) * 16;
+
+	devinet_init();
+	ip_fib_init();
+
+	/* All the timers, started at system startup tend
+	   to synchronize. Perturb it a bit.
+	 */
+	schedule_delayed_work(&expires_work,
+		net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
+
+	if (register_pernet_subsys(&rt_secret_timer_ops))
+		printk(KERN_ERR "Unable to setup rt_secret_timer\n");
+
+	if (ip_rt_proc_init())
+		printk(KERN_ERR "Unable to create route proc files\n");
+#ifdef CONFIG_XFRM
+	xfrm_init();
+	xfrm4_init();
+#endif
+	rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
+
+#ifdef CONFIG_SYSCTL
+	register_pernet_subsys(&sysctl_route_ops);
+#endif
+	return rc;
+}
+
+#ifdef CONFIG_SYSCTL
+/*
+ * We really need to sanitize the damn ipv4 init order, then all
+ * this nonsense will go away.
+ */
+void __init ip_static_sysctl_init(void)
+{
+	register_sysctl_paths(ipv4_path, ipv4_skeleton);
+}
+#endif
+
+EXPORT_SYMBOL(__ip_select_ident);
+EXPORT_SYMBOL(ip_route_input);
+EXPORT_SYMBOL(ip_route_output_key);
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
new file mode 100644
index 0000000..d346c22
--- /dev/null
+++ b/net/ipv4/syncookies.c
@@ -0,0 +1,364 @@
+/*
+ *  Syncookies implementation for the Linux kernel
+ *
+ *  Copyright (C) 1997 Andi Kleen
+ *  Based on ideas by D.J.Bernstein and Eric Schenk.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/tcp.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include <linux/cryptohash.h>
+#include <linux/kernel.h>
+#include <net/tcp.h>
+#include <net/route.h>
+
+/* Timestamps: lowest 9 bits store TCP options */
+#define TSBITS 9
+#define TSMASK (((__u32)1 << TSBITS) - 1)
+
+extern int sysctl_tcp_syncookies;
+
+__u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
+EXPORT_SYMBOL(syncookie_secret);
+
+static __init int init_syncookies(void)
+{
+	get_random_bytes(syncookie_secret, sizeof(syncookie_secret));
+	return 0;
+}
+__initcall(init_syncookies);
+
+#define COOKIEBITS 24	/* Upper bits store count */
+#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
+
+static DEFINE_PER_CPU(__u32, cookie_scratch)[16 + 5 + SHA_WORKSPACE_WORDS];
+
+static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
+		       u32 count, int c)
+{
+	__u32 *tmp = __get_cpu_var(cookie_scratch);
+
+	memcpy(tmp + 4, syncookie_secret[c], sizeof(syncookie_secret[c]));
+	tmp[0] = (__force u32)saddr;
+	tmp[1] = (__force u32)daddr;
+	tmp[2] = ((__force u32)sport << 16) + (__force u32)dport;
+	tmp[3] = count;
+	sha_transform(tmp + 16, (__u8 *)tmp, tmp + 16 + 5);
+
+	return tmp[17];
+}
+
+
+/*
+ * when syncookies are in effect and tcp timestamps are enabled we encode
+ * tcp options in the lowest 9 bits of the timestamp value that will be
+ * sent in the syn-ack.
+ * Since subsequent timestamps use the normal tcp_time_stamp value, we
+ * must make sure that the resulting initial timestamp is <= tcp_time_stamp.
+ */
+__u32 cookie_init_timestamp(struct request_sock *req)
+{
+	struct inet_request_sock *ireq;
+	u32 ts, ts_now = tcp_time_stamp;
+	u32 options = 0;
+
+	ireq = inet_rsk(req);
+	if (ireq->wscale_ok) {
+		options = ireq->snd_wscale;
+		options |= ireq->rcv_wscale << 4;
+	}
+	options |= ireq->sack_ok << 8;
+
+	ts = ts_now & ~TSMASK;
+	ts |= options;
+	if (ts > ts_now) {
+		ts >>= TSBITS;
+		ts--;
+		ts <<= TSBITS;
+		ts |= options;
+	}
+	return ts;
+}
+
+
+static __u32 secure_tcp_syn_cookie(__be32 saddr, __be32 daddr, __be16 sport,
+				   __be16 dport, __u32 sseq, __u32 count,
+				   __u32 data)
+{
+	/*
+	 * Compute the secure sequence number.
+	 * The output should be:
+	 *   HASH(sec1,saddr,sport,daddr,dport,sec1) + sseq + (count * 2^24)
+	 *      + (HASH(sec2,saddr,sport,daddr,dport,count,sec2) % 2^24).
+	 * Where sseq is their sequence number and count increases every
+	 * minute by 1.
+	 * As an extra hack, we add a small "data" value that encodes the
+	 * MSS into the second hash value.
+	 */
+
+	return (cookie_hash(saddr, daddr, sport, dport, 0, 0) +
+		sseq + (count << COOKIEBITS) +
+		((cookie_hash(saddr, daddr, sport, dport, count, 1) + data)
+		 & COOKIEMASK));
+}
+
+/*
+ * This retrieves the small "data" value from the syncookie.
+ * If the syncookie is bad, the data returned will be out of
+ * range.  This must be checked by the caller.
+ *
+ * The count value used to generate the cookie must be within
+ * "maxdiff" if the current (passed-in) "count".  The return value
+ * is (__u32)-1 if this test fails.
+ */
+static __u32 check_tcp_syn_cookie(__u32 cookie, __be32 saddr, __be32 daddr,
+				  __be16 sport, __be16 dport, __u32 sseq,
+				  __u32 count, __u32 maxdiff)
+{
+	__u32 diff;
+
+	/* Strip away the layers from the cookie */
+	cookie -= cookie_hash(saddr, daddr, sport, dport, 0, 0) + sseq;
+
+	/* Cookie is now reduced to (count * 2^24) ^ (hash % 2^24) */
+	diff = (count - (cookie >> COOKIEBITS)) & ((__u32) - 1 >> COOKIEBITS);
+	if (diff >= maxdiff)
+		return (__u32)-1;
+
+	return (cookie -
+		cookie_hash(saddr, daddr, sport, dport, count - diff, 1))
+		& COOKIEMASK;	/* Leaving the data behind */
+}
+
+/*
+ * This table has to be sorted and terminated with (__u16)-1.
+ * XXX generate a better table.
+ * Unresolved Issues: HIPPI with a 64k MSS is not well supported.
+ */
+static __u16 const msstab[] = {
+	64 - 1,
+	256 - 1,
+	512 - 1,
+	536 - 1,
+	1024 - 1,
+	1440 - 1,
+	1460 - 1,
+	4312 - 1,
+	(__u16)-1
+};
+/* The number doesn't include the -1 terminator */
+#define NUM_MSS (ARRAY_SIZE(msstab) - 1)
+
+/*
+ * Generate a syncookie.  mssp points to the mss, which is returned
+ * rounded down to the value encoded in the cookie.
+ */
+__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct iphdr *iph = ip_hdr(skb);
+	const struct tcphdr *th = tcp_hdr(skb);
+	int mssind;
+	const __u16 mss = *mssp;
+
+	tp->last_synq_overflow = jiffies;
+
+	/* XXX sort msstab[] by probability?  Binary search? */
+	for (mssind = 0; mss > msstab[mssind + 1]; mssind++)
+		;
+	*mssp = msstab[mssind] + 1;
+
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT);
+
+	return secure_tcp_syn_cookie(iph->saddr, iph->daddr,
+				     th->source, th->dest, ntohl(th->seq),
+				     jiffies / (HZ * 60), mssind);
+}
+
+/*
+ * This (misnamed) value is the age of syncookie which is permitted.
+ * Its ideal value should be dependent on TCP_TIMEOUT_INIT and
+ * sysctl_tcp_retries1. It's a rather complicated formula (exponential
+ * backoff) to compute at runtime so it's currently hardcoded here.
+ */
+#define COUNTER_TRIES 4
+/*
+ * Check if a ack sequence number is a valid syncookie.
+ * Return the decoded mss if it is, or 0 if not.
+ */
+static inline int cookie_check(struct sk_buff *skb, __u32 cookie)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+	const struct tcphdr *th = tcp_hdr(skb);
+	__u32 seq = ntohl(th->seq) - 1;
+	__u32 mssind = check_tcp_syn_cookie(cookie, iph->saddr, iph->daddr,
+					    th->source, th->dest, seq,
+					    jiffies / (HZ * 60),
+					    COUNTER_TRIES);
+
+	return mssind < NUM_MSS ? msstab[mssind] + 1 : 0;
+}
+
+static inline struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
+					   struct request_sock *req,
+					   struct dst_entry *dst)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct sock *child;
+
+	child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst);
+	if (child)
+		inet_csk_reqsk_queue_add(sk, req, child);
+	else
+		reqsk_free(req);
+
+	return child;
+}
+
+
+/*
+ * when syncookies are in effect and tcp timestamps are enabled we stored
+ * additional tcp options in the timestamp.
+ * This extracts these options from the timestamp echo.
+ *
+ * The lowest 4 bits are for snd_wscale
+ * The next 4 lsb are for rcv_wscale
+ * The next lsb is for sack_ok
+ */
+void cookie_check_timestamp(struct tcp_options_received *tcp_opt)
+{
+	/* echoed timestamp, 9 lowest bits contain options */
+	u32 options = tcp_opt->rcv_tsecr & TSMASK;
+
+	tcp_opt->snd_wscale = options & 0xf;
+	options >>= 4;
+	tcp_opt->rcv_wscale = options & 0xf;
+
+	tcp_opt->sack_ok = (options >> 4) & 0x1;
+
+	if (tcp_opt->sack_ok)
+		tcp_sack_reset(tcp_opt);
+
+	if (tcp_opt->snd_wscale || tcp_opt->rcv_wscale)
+		tcp_opt->wscale_ok = 1;
+}
+EXPORT_SYMBOL(cookie_check_timestamp);
+
+struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
+			     struct ip_options *opt)
+{
+	struct inet_request_sock *ireq;
+	struct tcp_request_sock *treq;
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct tcphdr *th = tcp_hdr(skb);
+	__u32 cookie = ntohl(th->ack_seq) - 1;
+	struct sock *ret = sk;
+	struct request_sock *req;
+	int mss;
+	struct rtable *rt;
+	__u8 rcv_wscale;
+	struct tcp_options_received tcp_opt;
+
+	if (!sysctl_tcp_syncookies || !th->ack)
+		goto out;
+
+	if (time_after(jiffies, tp->last_synq_overflow + TCP_TIMEOUT_INIT) ||
+	    (mss = cookie_check(skb, cookie)) == 0) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
+		goto out;
+	}
+
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
+
+	/* check for timestamp cookie support */
+	memset(&tcp_opt, 0, sizeof(tcp_opt));
+	tcp_parse_options(skb, &tcp_opt, 0);
+
+	if (tcp_opt.saw_tstamp)
+		cookie_check_timestamp(&tcp_opt);
+
+	ret = NULL;
+	req = inet_reqsk_alloc(&tcp_request_sock_ops); /* for safety */
+	if (!req)
+		goto out;
+
+	if (security_inet_conn_request(sk, skb, req)) {
+		reqsk_free(req);
+		goto out;
+	}
+	ireq = inet_rsk(req);
+	treq = tcp_rsk(req);
+	treq->rcv_isn		= ntohl(th->seq) - 1;
+	treq->snt_isn		= cookie;
+	req->mss		= mss;
+	ireq->loc_port		= th->dest;
+	ireq->rmt_port		= th->source;
+	ireq->loc_addr		= ip_hdr(skb)->daddr;
+	ireq->rmt_addr		= ip_hdr(skb)->saddr;
+	ireq->ecn_ok		= 0;
+	ireq->snd_wscale	= tcp_opt.snd_wscale;
+	ireq->rcv_wscale	= tcp_opt.rcv_wscale;
+	ireq->sack_ok		= tcp_opt.sack_ok;
+	ireq->wscale_ok		= tcp_opt.wscale_ok;
+	ireq->tstamp_ok		= tcp_opt.saw_tstamp;
+	req->ts_recent		= tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
+
+	/* We throwed the options of the initial SYN away, so we hope
+	 * the ACK carries the same options again (see RFC1122 4.2.3.8)
+	 */
+	if (opt && opt->optlen) {
+		int opt_size = sizeof(struct ip_options) + opt->optlen;
+
+		ireq->opt = kmalloc(opt_size, GFP_ATOMIC);
+		if (ireq->opt != NULL && ip_options_echo(ireq->opt, skb)) {
+			kfree(ireq->opt);
+			ireq->opt = NULL;
+		}
+	}
+
+	req->expires	= 0UL;
+	req->retrans	= 0;
+
+	/*
+	 * We need to lookup the route here to get at the correct
+	 * window size. We should better make sure that the window size
+	 * hasn't changed since we received the original syn, but I see
+	 * no easy way to do this.
+	 */
+	{
+		struct flowi fl = { .nl_u = { .ip4_u =
+					      { .daddr = ((opt && opt->srr) ?
+							  opt->faddr :
+							  ireq->rmt_addr),
+						.saddr = ireq->loc_addr,
+						.tos = RT_CONN_FLAGS(sk) } },
+				    .proto = IPPROTO_TCP,
+				    .flags = inet_sk_flowi_flags(sk),
+				    .uli_u = { .ports =
+					       { .sport = th->dest,
+						 .dport = th->source } } };
+		security_req_classify_flow(req, &fl);
+		if (ip_route_output_key(&init_net, &rt, &fl)) {
+			reqsk_free(req);
+			goto out;
+		}
+	}
+
+	/* Try to redo what tcp_v4_send_synack did. */
+	req->window_clamp = tp->window_clamp ? :dst_metric(&rt->u.dst, RTAX_WINDOW);
+
+	tcp_select_initial_window(tcp_full_space(sk), req->mss,
+				  &req->rcv_wnd, &req->window_clamp,
+				  ireq->wscale_ok, &rcv_wscale);
+
+	ireq->rcv_wscale  = rcv_wscale;
+
+	ret = get_cookie_sock(sk, skb, req, &rt->u.dst);
+out:	return ret;
+}
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
new file mode 100644
index 0000000..1bb10df
--- /dev/null
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -0,0 +1,876 @@
+/*
+ * sysctl_net_ipv4.c: sysctl interface to net IPV4 subsystem.
+ *
+ * Begun April 1, 1996, Mike Shaver.
+ * Added /proc/sys/net/ipv4 directory entry (empty =) ). [MS]
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <linux/igmp.h>
+#include <linux/inetdevice.h>
+#include <linux/seqlock.h>
+#include <linux/init.h>
+#include <net/snmp.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/cipso_ipv4.h>
+#include <net/inet_frag.h>
+
+static int zero;
+static int tcp_retr1_max = 255;
+static int ip_local_port_range_min[] = { 1, 1 };
+static int ip_local_port_range_max[] = { 65535, 65535 };
+
+/* Update system visible IP port range */
+static void set_local_port_range(int range[2])
+{
+	write_seqlock(&sysctl_local_ports.lock);
+	sysctl_local_ports.range[0] = range[0];
+	sysctl_local_ports.range[1] = range[1];
+	write_sequnlock(&sysctl_local_ports.lock);
+}
+
+/* Validate changes from /proc interface. */
+static int ipv4_local_port_range(ctl_table *table, int write, struct file *filp,
+				 void __user *buffer,
+				 size_t *lenp, loff_t *ppos)
+{
+	int ret;
+	int range[2];
+	ctl_table tmp = {
+		.data = &range,
+		.maxlen = sizeof(range),
+		.mode = table->mode,
+		.extra1 = &ip_local_port_range_min,
+		.extra2 = &ip_local_port_range_max,
+	};
+
+	inet_get_local_port_range(range, range + 1);
+	ret = proc_dointvec_minmax(&tmp, write, filp, buffer, lenp, ppos);
+
+	if (write && ret == 0) {
+		if (range[1] < range[0])
+			ret = -EINVAL;
+		else
+			set_local_port_range(range);
+	}
+
+	return ret;
+}
+
+/* Validate changes from sysctl interface. */
+static int ipv4_sysctl_local_port_range(ctl_table *table,
+					 void __user *oldval,
+					 size_t __user *oldlenp,
+					void __user *newval, size_t newlen)
+{
+	int ret;
+	int range[2];
+	ctl_table tmp = {
+		.data = &range,
+		.maxlen = sizeof(range),
+		.mode = table->mode,
+		.extra1 = &ip_local_port_range_min,
+		.extra2 = &ip_local_port_range_max,
+	};
+
+	inet_get_local_port_range(range, range + 1);
+	ret = sysctl_intvec(&tmp, oldval, oldlenp, newval, newlen);
+	if (ret == 0 && newval && newlen) {
+		if (range[1] < range[0])
+			ret = -EINVAL;
+		else
+			set_local_port_range(range);
+	}
+	return ret;
+}
+
+
+static int proc_tcp_congestion_control(ctl_table *ctl, int write, struct file * filp,
+				       void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	char val[TCP_CA_NAME_MAX];
+	ctl_table tbl = {
+		.data = val,
+		.maxlen = TCP_CA_NAME_MAX,
+	};
+	int ret;
+
+	tcp_get_default_congestion_control(val);
+
+	ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
+	if (write && ret == 0)
+		ret = tcp_set_default_congestion_control(val);
+	return ret;
+}
+
+static int sysctl_tcp_congestion_control(ctl_table *table,
+					 void __user *oldval,
+					 size_t __user *oldlenp,
+					 void __user *newval, size_t newlen)
+{
+	char val[TCP_CA_NAME_MAX];
+	ctl_table tbl = {
+		.data = val,
+		.maxlen = TCP_CA_NAME_MAX,
+	};
+	int ret;
+
+	tcp_get_default_congestion_control(val);
+	ret = sysctl_string(&tbl, oldval, oldlenp, newval, newlen);
+	if (ret == 1 && newval && newlen)
+		ret = tcp_set_default_congestion_control(val);
+	return ret;
+}
+
+static int proc_tcp_available_congestion_control(ctl_table *ctl,
+						 int write, struct file * filp,
+						 void __user *buffer, size_t *lenp,
+						 loff_t *ppos)
+{
+	ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX, };
+	int ret;
+
+	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
+	if (!tbl.data)
+		return -ENOMEM;
+	tcp_get_available_congestion_control(tbl.data, TCP_CA_BUF_MAX);
+	ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
+	kfree(tbl.data);
+	return ret;
+}
+
+static int proc_allowed_congestion_control(ctl_table *ctl,
+					   int write, struct file * filp,
+					   void __user *buffer, size_t *lenp,
+					   loff_t *ppos)
+{
+	ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
+	int ret;
+
+	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
+	if (!tbl.data)
+		return -ENOMEM;
+
+	tcp_get_allowed_congestion_control(tbl.data, tbl.maxlen);
+	ret = proc_dostring(&tbl, write, filp, buffer, lenp, ppos);
+	if (write && ret == 0)
+		ret = tcp_set_allowed_congestion_control(tbl.data);
+	kfree(tbl.data);
+	return ret;
+}
+
+static int strategy_allowed_congestion_control(ctl_table *table,
+					       void __user *oldval,
+					       size_t __user *oldlenp,
+					       void __user *newval,
+					       size_t newlen)
+{
+	ctl_table tbl = { .maxlen = TCP_CA_BUF_MAX };
+	int ret;
+
+	tbl.data = kmalloc(tbl.maxlen, GFP_USER);
+	if (!tbl.data)
+		return -ENOMEM;
+
+	tcp_get_available_congestion_control(tbl.data, tbl.maxlen);
+	ret = sysctl_string(&tbl, oldval, oldlenp, newval, newlen);
+	if (ret == 1 && newval && newlen)
+		ret = tcp_set_allowed_congestion_control(tbl.data);
+	kfree(tbl.data);
+
+	return ret;
+
+}
+
+static struct ctl_table ipv4_table[] = {
+	{
+		.ctl_name	= NET_IPV4_TCP_TIMESTAMPS,
+		.procname	= "tcp_timestamps",
+		.data		= &sysctl_tcp_timestamps,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_WINDOW_SCALING,
+		.procname	= "tcp_window_scaling",
+		.data		= &sysctl_tcp_window_scaling,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_SACK,
+		.procname	= "tcp_sack",
+		.data		= &sysctl_tcp_sack,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_RETRANS_COLLAPSE,
+		.procname	= "tcp_retrans_collapse",
+		.data		= &sysctl_tcp_retrans_collapse,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_DEFAULT_TTL,
+		.procname	= "ip_default_ttl",
+		.data		= &sysctl_ip_default_ttl,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &ipv4_doint_and_flush,
+		.strategy	= &ipv4_doint_and_flush_strategy,
+		.extra2		= &init_net,
+	},
+	{
+		.ctl_name	= NET_IPV4_NO_PMTU_DISC,
+		.procname	= "ip_no_pmtu_disc",
+		.data		= &ipv4_config.no_pmtu_disc,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_NONLOCAL_BIND,
+		.procname	= "ip_nonlocal_bind",
+		.data		= &sysctl_ip_nonlocal_bind,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_SYN_RETRIES,
+		.procname	= "tcp_syn_retries",
+		.data		= &sysctl_tcp_syn_retries,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_SYNACK_RETRIES,
+		.procname	= "tcp_synack_retries",
+		.data		= &sysctl_tcp_synack_retries,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_MAX_ORPHANS,
+		.procname	= "tcp_max_orphans",
+		.data		= &sysctl_tcp_max_orphans,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_MAX_TW_BUCKETS,
+		.procname	= "tcp_max_tw_buckets",
+		.data		= &tcp_death_row.sysctl_max_tw_buckets,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_DYNADDR,
+		.procname	= "ip_dynaddr",
+		.data		= &sysctl_ip_dynaddr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_KEEPALIVE_TIME,
+		.procname	= "tcp_keepalive_time",
+		.data		= &sysctl_tcp_keepalive_time,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_KEEPALIVE_PROBES,
+		.procname	= "tcp_keepalive_probes",
+		.data		= &sysctl_tcp_keepalive_probes,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_KEEPALIVE_INTVL,
+		.procname	= "tcp_keepalive_intvl",
+		.data		= &sysctl_tcp_keepalive_intvl,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_RETRIES1,
+		.procname	= "tcp_retries1",
+		.data		= &sysctl_tcp_retries1,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra2		= &tcp_retr1_max
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_RETRIES2,
+		.procname	= "tcp_retries2",
+		.data		= &sysctl_tcp_retries2,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_FIN_TIMEOUT,
+		.procname	= "tcp_fin_timeout",
+		.data		= &sysctl_tcp_fin_timeout,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+#ifdef CONFIG_SYN_COOKIES
+	{
+		.ctl_name	= NET_TCP_SYNCOOKIES,
+		.procname	= "tcp_syncookies",
+		.data		= &sysctl_tcp_syncookies,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+#endif
+	{
+		.ctl_name	= NET_TCP_TW_RECYCLE,
+		.procname	= "tcp_tw_recycle",
+		.data		= &tcp_death_row.sysctl_tw_recycle,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_ABORT_ON_OVERFLOW,
+		.procname	= "tcp_abort_on_overflow",
+		.data		= &sysctl_tcp_abort_on_overflow,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_STDURG,
+		.procname	= "tcp_stdurg",
+		.data		= &sysctl_tcp_stdurg,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_RFC1337,
+		.procname	= "tcp_rfc1337",
+		.data		= &sysctl_tcp_rfc1337,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_MAX_SYN_BACKLOG,
+		.procname	= "tcp_max_syn_backlog",
+		.data		= &sysctl_max_syn_backlog,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_LOCAL_PORT_RANGE,
+		.procname	= "ip_local_port_range",
+		.data		= &sysctl_local_ports.range,
+		.maxlen		= sizeof(sysctl_local_ports.range),
+		.mode		= 0644,
+		.proc_handler	= &ipv4_local_port_range,
+		.strategy	= &ipv4_sysctl_local_port_range,
+	},
+#ifdef CONFIG_IP_MULTICAST
+	{
+		.ctl_name	= NET_IPV4_IGMP_MAX_MEMBERSHIPS,
+		.procname	= "igmp_max_memberships",
+		.data		= &sysctl_igmp_max_memberships,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+
+#endif
+	{
+		.ctl_name	= NET_IPV4_IGMP_MAX_MSF,
+		.procname	= "igmp_max_msf",
+		.data		= &sysctl_igmp_max_msf,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_INET_PEER_THRESHOLD,
+		.procname	= "inet_peer_threshold",
+		.data		= &inet_peer_threshold,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_INET_PEER_MINTTL,
+		.procname	= "inet_peer_minttl",
+		.data		= &inet_peer_minttl,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.ctl_name	= NET_IPV4_INET_PEER_MAXTTL,
+		.procname	= "inet_peer_maxttl",
+		.data		= &inet_peer_maxttl,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.ctl_name	= NET_IPV4_INET_PEER_GC_MINTIME,
+		.procname	= "inet_peer_gc_mintime",
+		.data		= &inet_peer_gc_mintime,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.ctl_name	= NET_IPV4_INET_PEER_GC_MAXTIME,
+		.procname	= "inet_peer_gc_maxtime",
+		.data		= &inet_peer_gc_maxtime,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_jiffies,
+		.strategy	= &sysctl_jiffies
+	},
+	{
+		.ctl_name	= NET_TCP_ORPHAN_RETRIES,
+		.procname	= "tcp_orphan_retries",
+		.data		= &sysctl_tcp_orphan_retries,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_FACK,
+		.procname	= "tcp_fack",
+		.data		= &sysctl_tcp_fack,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_REORDERING,
+		.procname	= "tcp_reordering",
+		.data		= &sysctl_tcp_reordering,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_ECN,
+		.procname	= "tcp_ecn",
+		.data		= &sysctl_tcp_ecn,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_DSACK,
+		.procname	= "tcp_dsack",
+		.data		= &sysctl_tcp_dsack,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_MEM,
+		.procname	= "tcp_mem",
+		.data		= &sysctl_tcp_mem,
+		.maxlen		= sizeof(sysctl_tcp_mem),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_WMEM,
+		.procname	= "tcp_wmem",
+		.data		= &sysctl_tcp_wmem,
+		.maxlen		= sizeof(sysctl_tcp_wmem),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_RMEM,
+		.procname	= "tcp_rmem",
+		.data		= &sysctl_tcp_rmem,
+		.maxlen		= sizeof(sysctl_tcp_rmem),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_APP_WIN,
+		.procname	= "tcp_app_win",
+		.data		= &sysctl_tcp_app_win,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_ADV_WIN_SCALE,
+		.procname	= "tcp_adv_win_scale",
+		.data		= &sysctl_tcp_adv_win_scale,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_TW_REUSE,
+		.procname	= "tcp_tw_reuse",
+		.data		= &sysctl_tcp_tw_reuse,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_FRTO,
+		.procname	= "tcp_frto",
+		.data		= &sysctl_tcp_frto,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_FRTO_RESPONSE,
+		.procname	= "tcp_frto_response",
+		.data		= &sysctl_tcp_frto_response,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_LOW_LATENCY,
+		.procname	= "tcp_low_latency",
+		.data		= &sysctl_tcp_low_latency,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_TCP_NO_METRICS_SAVE,
+		.procname	= "tcp_no_metrics_save",
+		.data		= &sysctl_tcp_nometrics_save,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_TCP_MODERATE_RCVBUF,
+		.procname	= "tcp_moderate_rcvbuf",
+		.data		= &sysctl_tcp_moderate_rcvbuf,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_TCP_TSO_WIN_DIVISOR,
+		.procname	= "tcp_tso_win_divisor",
+		.data		= &sysctl_tcp_tso_win_divisor,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_TCP_CONG_CONTROL,
+		.procname	= "tcp_congestion_control",
+		.mode		= 0644,
+		.maxlen		= TCP_CA_NAME_MAX,
+		.proc_handler	= &proc_tcp_congestion_control,
+		.strategy	= &sysctl_tcp_congestion_control,
+	},
+	{
+		.ctl_name	= NET_TCP_ABC,
+		.procname	= "tcp_abc",
+		.data		= &sysctl_tcp_abc,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_TCP_MTU_PROBING,
+		.procname	= "tcp_mtu_probing",
+		.data		= &sysctl_tcp_mtu_probing,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_TCP_BASE_MSS,
+		.procname	= "tcp_base_mss",
+		.data		= &sysctl_tcp_base_mss,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS,
+		.procname	= "tcp_workaround_signed_windows",
+		.data		= &sysctl_tcp_workaround_signed_windows,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+#ifdef CONFIG_NET_DMA
+	{
+		.ctl_name	= NET_TCP_DMA_COPYBREAK,
+		.procname	= "tcp_dma_copybreak",
+		.data		= &sysctl_tcp_dma_copybreak,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+#endif
+	{
+		.ctl_name	= NET_TCP_SLOW_START_AFTER_IDLE,
+		.procname	= "tcp_slow_start_after_idle",
+		.data		= &sysctl_tcp_slow_start_after_idle,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+#ifdef CONFIG_NETLABEL
+	{
+		.ctl_name	= NET_CIPSOV4_CACHE_ENABLE,
+		.procname	= "cipso_cache_enable",
+		.data		= &cipso_v4_cache_enabled,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_CIPSOV4_CACHE_BUCKET_SIZE,
+		.procname	= "cipso_cache_bucket_size",
+		.data		= &cipso_v4_cache_bucketsize,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_CIPSOV4_RBM_OPTFMT,
+		.procname	= "cipso_rbm_optfmt",
+		.data		= &cipso_v4_rbm_optfmt,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= NET_CIPSOV4_RBM_STRICTVALID,
+		.procname	= "cipso_rbm_strictvalid",
+		.data		= &cipso_v4_rbm_strictvalid,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+#endif /* CONFIG_NETLABEL */
+	{
+		.procname	= "tcp_available_congestion_control",
+		.maxlen		= TCP_CA_BUF_MAX,
+		.mode		= 0444,
+		.proc_handler   = &proc_tcp_available_congestion_control,
+	},
+	{
+		.ctl_name	= NET_TCP_ALLOWED_CONG_CONTROL,
+		.procname	= "tcp_allowed_congestion_control",
+		.maxlen		= TCP_CA_BUF_MAX,
+		.mode		= 0644,
+		.proc_handler   = &proc_allowed_congestion_control,
+		.strategy	= &strategy_allowed_congestion_control,
+	},
+	{
+		.ctl_name	= NET_TCP_MAX_SSTHRESH,
+		.procname	= "tcp_max_ssthresh",
+		.data		= &sysctl_tcp_max_ssthresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "udp_mem",
+		.data		= &sysctl_udp_mem,
+		.maxlen		= sizeof(sysctl_udp_mem),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "udp_rmem_min",
+		.data		= &sysctl_udp_rmem_min,
+		.maxlen		= sizeof(sysctl_udp_rmem_min),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "udp_wmem_min",
+		.data		= &sysctl_udp_wmem_min,
+		.maxlen		= sizeof(sysctl_udp_wmem_min),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.strategy	= &sysctl_intvec,
+		.extra1		= &zero
+	},
+	{ .ctl_name = 0 }
+};
+
+static struct ctl_table ipv4_net_table[] = {
+	{
+		.ctl_name	= NET_IPV4_ICMP_ECHO_IGNORE_ALL,
+		.procname	= "icmp_echo_ignore_all",
+		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_all,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_ICMP_ECHO_IGNORE_BROADCASTS,
+		.procname	= "icmp_echo_ignore_broadcasts",
+		.data		= &init_net.ipv4.sysctl_icmp_echo_ignore_broadcasts,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_ICMP_IGNORE_BOGUS_ERROR_RESPONSES,
+		.procname	= "icmp_ignore_bogus_error_responses",
+		.data		= &init_net.ipv4.sysctl_icmp_ignore_bogus_error_responses,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_ICMP_ERRORS_USE_INBOUND_IFADDR,
+		.procname	= "icmp_errors_use_inbound_ifaddr",
+		.data		= &init_net.ipv4.sysctl_icmp_errors_use_inbound_ifaddr,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= NET_IPV4_ICMP_RATELIMIT,
+		.procname	= "icmp_ratelimit",
+		.data		= &init_net.ipv4.sysctl_icmp_ratelimit,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_ms_jiffies,
+		.strategy	= &sysctl_ms_jiffies
+	},
+	{
+		.ctl_name	= NET_IPV4_ICMP_RATEMASK,
+		.procname	= "icmp_ratemask",
+		.data		= &init_net.ipv4.sysctl_icmp_ratemask,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{ }
+};
+
+struct ctl_path net_ipv4_ctl_path[] = {
+	{ .procname = "net", .ctl_name = CTL_NET, },
+	{ .procname = "ipv4", .ctl_name = NET_IPV4, },
+	{ },
+};
+EXPORT_SYMBOL_GPL(net_ipv4_ctl_path);
+
+static __net_init int ipv4_sysctl_init_net(struct net *net)
+{
+	struct ctl_table *table;
+
+	table = ipv4_net_table;
+	if (net != &init_net) {
+		table = kmemdup(table, sizeof(ipv4_net_table), GFP_KERNEL);
+		if (table == NULL)
+			goto err_alloc;
+
+		table[0].data =
+			&net->ipv4.sysctl_icmp_echo_ignore_all;
+		table[1].data =
+			&net->ipv4.sysctl_icmp_echo_ignore_broadcasts;
+		table[2].data =
+			&net->ipv4.sysctl_icmp_ignore_bogus_error_responses;
+		table[3].data =
+			&net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr;
+		table[4].data =
+			&net->ipv4.sysctl_icmp_ratelimit;
+		table[5].data =
+			&net->ipv4.sysctl_icmp_ratemask;
+	}
+
+	net->ipv4.ipv4_hdr = register_net_sysctl_table(net,
+			net_ipv4_ctl_path, table);
+	if (net->ipv4.ipv4_hdr == NULL)
+		goto err_reg;
+
+	return 0;
+
+err_reg:
+	if (net != &init_net)
+		kfree(table);
+err_alloc:
+	return -ENOMEM;
+}
+
+static __net_exit void ipv4_sysctl_exit_net(struct net *net)
+{
+	struct ctl_table *table;
+
+	table = net->ipv4.ipv4_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->ipv4.ipv4_hdr);
+	kfree(table);
+}
+
+static __net_initdata struct pernet_operations ipv4_sysctl_ops = {
+	.init = ipv4_sysctl_init_net,
+	.exit = ipv4_sysctl_exit_net,
+};
+
+static __init int sysctl_ipv4_init(void)
+{
+	struct ctl_table_header *hdr;
+
+	hdr = register_sysctl_paths(net_ipv4_ctl_path, ipv4_table);
+	if (hdr == NULL)
+		return -ENOMEM;
+
+	if (register_pernet_subsys(&ipv4_sysctl_ops)) {
+		unregister_sysctl_table(hdr);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+__initcall(sysctl_ipv4_init);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
new file mode 100644
index 0000000..473ff5b
--- /dev/null
+++ b/net/ipv4/tcp.c
@@ -0,0 +1,2798 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *		Corey Minyard <wf-rch!minyard@relay.EU.net>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ *		Linus Torvalds, <torvalds@cs.helsinki.fi>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Matthew Dillon, <dillon@apollo.west.oic.com>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ *
+ * Fixes:
+ *		Alan Cox	:	Numerous verify_area() calls
+ *		Alan Cox	:	Set the ACK bit on a reset
+ *		Alan Cox	:	Stopped it crashing if it closed while
+ *					sk->inuse=1 and was trying to connect
+ *					(tcp_err()).
+ *		Alan Cox	:	All icmp error handling was broken
+ *					pointers passed where wrong and the
+ *					socket was looked up backwards. Nobody
+ *					tested any icmp error code obviously.
+ *		Alan Cox	:	tcp_err() now handled properly. It
+ *					wakes people on errors. poll
+ *					behaves and the icmp error race
+ *					has gone by moving it into sock.c
+ *		Alan Cox	:	tcp_send_reset() fixed to work for
+ *					everything not just packets for
+ *					unknown sockets.
+ *		Alan Cox	:	tcp option processing.
+ *		Alan Cox	:	Reset tweaked (still not 100%) [Had
+ *					syn rule wrong]
+ *		Herp Rosmanith  :	More reset fixes
+ *		Alan Cox	:	No longer acks invalid rst frames.
+ *					Acking any kind of RST is right out.
+ *		Alan Cox	:	Sets an ignore me flag on an rst
+ *					receive otherwise odd bits of prattle
+ *					escape still
+ *		Alan Cox	:	Fixed another acking RST frame bug.
+ *					Should stop LAN workplace lockups.
+ *		Alan Cox	: 	Some tidyups using the new skb list
+ *					facilities
+ *		Alan Cox	:	sk->keepopen now seems to work
+ *		Alan Cox	:	Pulls options out correctly on accepts
+ *		Alan Cox	:	Fixed assorted sk->rqueue->next errors
+ *		Alan Cox	:	PSH doesn't end a TCP read. Switched a
+ *					bit to skb ops.
+ *		Alan Cox	:	Tidied tcp_data to avoid a potential
+ *					nasty.
+ *		Alan Cox	:	Added some better commenting, as the
+ *					tcp is hard to follow
+ *		Alan Cox	:	Removed incorrect check for 20 * psh
+ *	Michael O'Reilly	:	ack < copied bug fix.
+ *	Johannes Stille		:	Misc tcp fixes (not all in yet).
+ *		Alan Cox	:	FIN with no memory -> CRASH
+ *		Alan Cox	:	Added socket option proto entries.
+ *					Also added awareness of them to accept.
+ *		Alan Cox	:	Added TCP options (SOL_TCP)
+ *		Alan Cox	:	Switched wakeup calls to callbacks,
+ *					so the kernel can layer network
+ *					sockets.
+ *		Alan Cox	:	Use ip_tos/ip_ttl settings.
+ *		Alan Cox	:	Handle FIN (more) properly (we hope).
+ *		Alan Cox	:	RST frames sent on unsynchronised
+ *					state ack error.
+ *		Alan Cox	:	Put in missing check for SYN bit.
+ *		Alan Cox	:	Added tcp_select_window() aka NET2E
+ *					window non shrink trick.
+ *		Alan Cox	:	Added a couple of small NET2E timer
+ *					fixes
+ *		Charles Hedrick :	TCP fixes
+ *		Toomas Tamm	:	TCP window fixes
+ *		Alan Cox	:	Small URG fix to rlogin ^C ack fight
+ *		Charles Hedrick	:	Rewrote most of it to actually work
+ *		Linus		:	Rewrote tcp_read() and URG handling
+ *					completely
+ *		Gerhard Koerting:	Fixed some missing timer handling
+ *		Matthew Dillon  :	Reworked TCP machine states as per RFC
+ *		Gerhard Koerting:	PC/TCP workarounds
+ *		Adam Caldwell	:	Assorted timer/timing errors
+ *		Matthew Dillon	:	Fixed another RST bug
+ *		Alan Cox	:	Move to kernel side addressing changes.
+ *		Alan Cox	:	Beginning work on TCP fastpathing
+ *					(not yet usable)
+ *		Arnt Gulbrandsen:	Turbocharged tcp_check() routine.
+ *		Alan Cox	:	TCP fast path debugging
+ *		Alan Cox	:	Window clamping
+ *		Michael Riepe	:	Bug in tcp_check()
+ *		Matt Dillon	:	More TCP improvements and RST bug fixes
+ *		Matt Dillon	:	Yet more small nasties remove from the
+ *					TCP code (Be very nice to this man if
+ *					tcp finally works 100%) 8)
+ *		Alan Cox	:	BSD accept semantics.
+ *		Alan Cox	:	Reset on closedown bug.
+ *	Peter De Schrijver	:	ENOTCONN check missing in tcp_sendto().
+ *		Michael Pall	:	Handle poll() after URG properly in
+ *					all cases.
+ *		Michael Pall	:	Undo the last fix in tcp_read_urg()
+ *					(multi URG PUSH broke rlogin).
+ *		Michael Pall	:	Fix the multi URG PUSH problem in
+ *					tcp_readable(), poll() after URG
+ *					works now.
+ *		Michael Pall	:	recv(...,MSG_OOB) never blocks in the
+ *					BSD api.
+ *		Alan Cox	:	Changed the semantics of sk->socket to
+ *					fix a race and a signal problem with
+ *					accept() and async I/O.
+ *		Alan Cox	:	Relaxed the rules on tcp_sendto().
+ *		Yury Shevchuk	:	Really fixed accept() blocking problem.
+ *		Craig I. Hagan  :	Allow for BSD compatible TIME_WAIT for
+ *					clients/servers which listen in on
+ *					fixed ports.
+ *		Alan Cox	:	Cleaned the above up and shrank it to
+ *					a sensible code size.
+ *		Alan Cox	:	Self connect lockup fix.
+ *		Alan Cox	:	No connect to multicast.
+ *		Ross Biro	:	Close unaccepted children on master
+ *					socket close.
+ *		Alan Cox	:	Reset tracing code.
+ *		Alan Cox	:	Spurious resets on shutdown.
+ *		Alan Cox	:	Giant 15 minute/60 second timer error
+ *		Alan Cox	:	Small whoops in polling before an
+ *					accept.
+ *		Alan Cox	:	Kept the state trace facility since
+ *					it's handy for debugging.
+ *		Alan Cox	:	More reset handler fixes.
+ *		Alan Cox	:	Started rewriting the code based on
+ *					the RFC's for other useful protocol
+ *					references see: Comer, KA9Q NOS, and
+ *					for a reference on the difference
+ *					between specifications and how BSD
+ *					works see the 4.4lite source.
+ *		A.N.Kuznetsov	:	Don't time wait on completion of tidy
+ *					close.
+ *		Linus Torvalds	:	Fin/Shutdown & copied_seq changes.
+ *		Linus Torvalds	:	Fixed BSD port reuse to work first syn
+ *		Alan Cox	:	Reimplemented timers as per the RFC
+ *					and using multiple timers for sanity.
+ *		Alan Cox	:	Small bug fixes, and a lot of new
+ *					comments.
+ *		Alan Cox	:	Fixed dual reader crash by locking
+ *					the buffers (much like datagram.c)
+ *		Alan Cox	:	Fixed stuck sockets in probe. A probe
+ *					now gets fed up of retrying without
+ *					(even a no space) answer.
+ *		Alan Cox	:	Extracted closing code better
+ *		Alan Cox	:	Fixed the closing state machine to
+ *					resemble the RFC.
+ *		Alan Cox	:	More 'per spec' fixes.
+ *		Jorge Cwik	:	Even faster checksumming.
+ *		Alan Cox	:	tcp_data() doesn't ack illegal PSH
+ *					only frames. At least one pc tcp stack
+ *					generates them.
+ *		Alan Cox	:	Cache last socket.
+ *		Alan Cox	:	Per route irtt.
+ *		Matt Day	:	poll()->select() match BSD precisely on error
+ *		Alan Cox	:	New buffers
+ *		Marc Tamsky	:	Various sk->prot->retransmits and
+ *					sk->retransmits misupdating fixed.
+ *					Fixed tcp_write_timeout: stuck close,
+ *					and TCP syn retries gets used now.
+ *		Mark Yarvis	:	In tcp_read_wakeup(), don't send an
+ *					ack if state is TCP_CLOSED.
+ *		Alan Cox	:	Look up device on a retransmit - routes may
+ *					change. Doesn't yet cope with MSS shrink right
+ *					but it's a start!
+ *		Marc Tamsky	:	Closing in closing fixes.
+ *		Mike Shaver	:	RFC1122 verifications.
+ *		Alan Cox	:	rcv_saddr errors.
+ *		Alan Cox	:	Block double connect().
+ *		Alan Cox	:	Small hooks for enSKIP.
+ *		Alexey Kuznetsov:	Path MTU discovery.
+ *		Alan Cox	:	Support soft errors.
+ *		Alan Cox	:	Fix MTU discovery pathological case
+ *					when the remote claims no mtu!
+ *		Marc Tamsky	:	TCP_CLOSE fix.
+ *		Colin (G3TNE)	:	Send a reset on syn ack replies in
+ *					window but wrong (fixes NT lpd problems)
+ *		Pedro Roque	:	Better TCP window handling, delayed ack.
+ *		Joerg Reuter	:	No modification of locked buffers in
+ *					tcp_do_retransmit()
+ *		Eric Schenk	:	Changed receiver side silly window
+ *					avoidance algorithm to BSD style
+ *					algorithm. This doubles throughput
+ *					against machines running Solaris,
+ *					and seems to result in general
+ *					improvement.
+ *	Stefan Magdalinski	:	adjusted tcp_readable() to fix FIONREAD
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *	Mike McLagan		:	Routing by source
+ *		Keith Owens	:	Do proper merging with partial SKB's in
+ *					tcp_do_sendmsg to avoid burstiness.
+ *		Eric Schenk	:	Fix fast close down bug with
+ *					shutdown() followed by close().
+ *		Andi Kleen 	:	Make poll agree with SIGIO
+ *	Salvatore Sanfilippo	:	Support SO_LINGER with linger == 1 and
+ *					lingertime == 0 (RFC 793 ABORT Call)
+ *	Hirokazu Takahashi	:	Use copy_from_user() instead of
+ *					csum_and_copy_from_user() if possible.
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or(at your option) any later version.
+ *
+ * Description of States:
+ *
+ *	TCP_SYN_SENT		sent a connection request, waiting for ack
+ *
+ *	TCP_SYN_RECV		received a connection request, sent ack,
+ *				waiting for final ack in three-way handshake.
+ *
+ *	TCP_ESTABLISHED		connection established
+ *
+ *	TCP_FIN_WAIT1		our side has shutdown, waiting to complete
+ *				transmission of remaining buffered data
+ *
+ *	TCP_FIN_WAIT2		all buffered data sent, waiting for remote
+ *				to shutdown
+ *
+ *	TCP_CLOSING		both sides have shutdown but we still have
+ *				data we have to finish sending
+ *
+ *	TCP_TIME_WAIT		timeout to catch resent junk before entering
+ *				closed, can only be entered from FIN_WAIT2
+ *				or CLOSING.  Required because the other end
+ *				may not have gotten our last ACK causing it
+ *				to retransmit the data packet (which we ignore)
+ *
+ *	TCP_CLOSE_WAIT		remote side has shutdown and is waiting for
+ *				us to finish writing our data and to shutdown
+ *				(we have to close() to move on to LAST_ACK)
+ *
+ *	TCP_LAST_ACK		out side has shutdown after remote has
+ *				shutdown.  There may still be data in our
+ *				buffer that we have to finish sending
+ *
+ *	TCP_CLOSE		socket is finished
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/skbuff.h>
+#include <linux/scatterlist.h>
+#include <linux/splice.h>
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <linux/random.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
+#include <linux/cache.h>
+#include <linux/err.h>
+#include <linux/crypto.h>
+
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+#include <net/netdma.h>
+#include <net/sock.h>
+
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+
+int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
+
+atomic_t tcp_orphan_count = ATOMIC_INIT(0);
+
+EXPORT_SYMBOL_GPL(tcp_orphan_count);
+
+int sysctl_tcp_mem[3] __read_mostly;
+int sysctl_tcp_wmem[3] __read_mostly;
+int sysctl_tcp_rmem[3] __read_mostly;
+
+EXPORT_SYMBOL(sysctl_tcp_mem);
+EXPORT_SYMBOL(sysctl_tcp_rmem);
+EXPORT_SYMBOL(sysctl_tcp_wmem);
+
+atomic_t tcp_memory_allocated;	/* Current allocated memory. */
+atomic_t tcp_sockets_allocated;	/* Current number of TCP sockets. */
+
+EXPORT_SYMBOL(tcp_memory_allocated);
+EXPORT_SYMBOL(tcp_sockets_allocated);
+
+/*
+ * TCP splice context
+ */
+struct tcp_splice_state {
+	struct pipe_inode_info *pipe;
+	size_t len;
+	unsigned int flags;
+};
+
+/*
+ * Pressure flag: try to collapse.
+ * Technical note: it is used by multiple contexts non atomically.
+ * All the __sk_mem_schedule() is of this nature: accounting
+ * is strict, actions are advisory and have some latency.
+ */
+int tcp_memory_pressure __read_mostly;
+
+EXPORT_SYMBOL(tcp_memory_pressure);
+
+void tcp_enter_memory_pressure(struct sock *sk)
+{
+	if (!tcp_memory_pressure) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
+		tcp_memory_pressure = 1;
+	}
+}
+
+EXPORT_SYMBOL(tcp_enter_memory_pressure);
+
+/*
+ *	Wait for a TCP event.
+ *
+ *	Note that we don't need to lock the socket, as the upper poll layers
+ *	take care of normal races (between the test and the event) and we don't
+ *	go look at any of the socket buffers directly.
+ */
+unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+	unsigned int mask;
+	struct sock *sk = sock->sk;
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	poll_wait(file, sk->sk_sleep, wait);
+	if (sk->sk_state == TCP_LISTEN)
+		return inet_csk_listen_poll(sk);
+
+	/* Socket is not locked. We are protected from async events
+	 * by poll logic and correct handling of state changes
+	 * made by other threads is impossible in any case.
+	 */
+
+	mask = 0;
+	if (sk->sk_err)
+		mask = POLLERR;
+
+	/*
+	 * POLLHUP is certainly not done right. But poll() doesn't
+	 * have a notion of HUP in just one direction, and for a
+	 * socket the read side is more interesting.
+	 *
+	 * Some poll() documentation says that POLLHUP is incompatible
+	 * with the POLLOUT/POLLWR flags, so somebody should check this
+	 * all. But careful, it tends to be safer to return too many
+	 * bits than too few, and you can easily break real applications
+	 * if you don't tell them that something has hung up!
+	 *
+	 * Check-me.
+	 *
+	 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
+	 * our fs/select.c). It means that after we received EOF,
+	 * poll always returns immediately, making impossible poll() on write()
+	 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
+	 * if and only if shutdown has been made in both directions.
+	 * Actually, it is interesting to look how Solaris and DUX
+	 * solve this dilemma. I would prefer, if POLLHUP were maskable,
+	 * then we could set it on SND_SHUTDOWN. BTW examples given
+	 * in Stevens' books assume exactly this behaviour, it explains
+	 * why POLLHUP is incompatible with POLLOUT.	--ANK
+	 *
+	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
+	 * blocking on fresh not-connected or disconnected socket. --ANK
+	 */
+	if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
+		mask |= POLLHUP;
+	if (sk->sk_shutdown & RCV_SHUTDOWN)
+		mask |= POLLIN | POLLRDNORM | POLLRDHUP;
+
+	/* Connected? */
+	if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		int target = sock_rcvlowat(sk, 0, INT_MAX);
+
+		if (tp->urg_seq == tp->copied_seq &&
+		    !sock_flag(sk, SOCK_URGINLINE) &&
+		    tp->urg_data)
+			target--;
+
+		/* Potential race condition. If read of tp below will
+		 * escape above sk->sk_state, we can be illegally awaken
+		 * in SYN_* states. */
+		if (tp->rcv_nxt - tp->copied_seq >= target)
+			mask |= POLLIN | POLLRDNORM;
+
+		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
+			if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
+				mask |= POLLOUT | POLLWRNORM;
+			} else {  /* send SIGIO later */
+				set_bit(SOCK_ASYNC_NOSPACE,
+					&sk->sk_socket->flags);
+				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+
+				/* Race breaker. If space is freed after
+				 * wspace test but before the flags are set,
+				 * IO signal will be lost.
+				 */
+				if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
+					mask |= POLLOUT | POLLWRNORM;
+			}
+		}
+
+		if (tp->urg_data & TCP_URG_VALID)
+			mask |= POLLPRI;
+	}
+	return mask;
+}
+
+int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int answ;
+
+	switch (cmd) {
+	case SIOCINQ:
+		if (sk->sk_state == TCP_LISTEN)
+			return -EINVAL;
+
+		lock_sock(sk);
+		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
+			answ = 0;
+		else if (sock_flag(sk, SOCK_URGINLINE) ||
+			 !tp->urg_data ||
+			 before(tp->urg_seq, tp->copied_seq) ||
+			 !before(tp->urg_seq, tp->rcv_nxt)) {
+			answ = tp->rcv_nxt - tp->copied_seq;
+
+			/* Subtract 1, if FIN is in queue. */
+			if (answ && !skb_queue_empty(&sk->sk_receive_queue))
+				answ -=
+		       tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin;
+		} else
+			answ = tp->urg_seq - tp->copied_seq;
+		release_sock(sk);
+		break;
+	case SIOCATMARK:
+		answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
+		break;
+	case SIOCOUTQ:
+		if (sk->sk_state == TCP_LISTEN)
+			return -EINVAL;
+
+		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
+			answ = 0;
+		else
+			answ = tp->write_seq - tp->snd_una;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return put_user(answ, (int __user *)arg);
+}
+
+static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+	tp->pushed_seq = tp->write_seq;
+}
+
+static inline int forced_push(struct tcp_sock *tp)
+{
+	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
+}
+
+static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
+
+	skb->csum    = 0;
+	tcb->seq     = tcb->end_seq = tp->write_seq;
+	tcb->flags   = TCPCB_FLAG_ACK;
+	tcb->sacked  = 0;
+	skb_header_release(skb);
+	tcp_add_write_queue_tail(sk, skb);
+	sk->sk_wmem_queued += skb->truesize;
+	sk_mem_charge(sk, skb->truesize);
+	if (tp->nonagle & TCP_NAGLE_PUSH)
+		tp->nonagle &= ~TCP_NAGLE_PUSH;
+}
+
+static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
+				struct sk_buff *skb)
+{
+	if (flags & MSG_OOB)
+		tp->snd_up = tp->write_seq;
+}
+
+static inline void tcp_push(struct sock *sk, int flags, int mss_now,
+			    int nonagle)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tcp_send_head(sk)) {
+		struct sk_buff *skb = tcp_write_queue_tail(sk);
+		if (!(flags & MSG_MORE) || forced_push(tp))
+			tcp_mark_push(tp, skb);
+		tcp_mark_urg(tp, flags, skb);
+		__tcp_push_pending_frames(sk, mss_now,
+					  (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
+	}
+}
+
+static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
+				unsigned int offset, size_t len)
+{
+	struct tcp_splice_state *tss = rd_desc->arg.data;
+	int ret;
+
+	ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
+			      tss->flags);
+	if (ret > 0)
+		rd_desc->count -= ret;
+	return ret;
+}
+
+static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
+{
+	/* Store TCP splice context information in read_descriptor_t. */
+	read_descriptor_t rd_desc = {
+		.arg.data = tss,
+		.count	  = tss->len,
+	};
+
+	return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
+}
+
+/**
+ *  tcp_splice_read - splice data from TCP socket to a pipe
+ * @sock:	socket to splice from
+ * @ppos:	position (not valid)
+ * @pipe:	pipe to splice to
+ * @len:	number of bytes to splice
+ * @flags:	splice modifier flags
+ *
+ * Description:
+ *    Will read pages from given socket and fill them into a pipe.
+ *
+ **/
+ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
+			struct pipe_inode_info *pipe, size_t len,
+			unsigned int flags)
+{
+	struct sock *sk = sock->sk;
+	struct tcp_splice_state tss = {
+		.pipe = pipe,
+		.len = len,
+		.flags = flags,
+	};
+	long timeo;
+	ssize_t spliced;
+	int ret;
+
+	/*
+	 * We can't seek on a socket input
+	 */
+	if (unlikely(*ppos))
+		return -ESPIPE;
+
+	ret = spliced = 0;
+
+	lock_sock(sk);
+
+	timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
+	while (tss.len) {
+		ret = __tcp_splice_read(sk, &tss);
+		if (ret < 0)
+			break;
+		else if (!ret) {
+			if (spliced)
+				break;
+			if (sock_flag(sk, SOCK_DONE))
+				break;
+			if (sk->sk_err) {
+				ret = sock_error(sk);
+				break;
+			}
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
+				break;
+			if (sk->sk_state == TCP_CLOSE) {
+				/*
+				 * This occurs when user tries to read
+				 * from never connected socket.
+				 */
+				if (!sock_flag(sk, SOCK_DONE))
+					ret = -ENOTCONN;
+				break;
+			}
+			if (flags & SPLICE_F_NONBLOCK) {
+				ret = -EAGAIN;
+				break;
+			}
+			if (!timeo) {
+				ret = -EAGAIN;
+				break;
+			}
+			sk_wait_data(sk, &timeo);
+			if (signal_pending(current)) {
+				ret = sock_intr_errno(timeo);
+				break;
+			}
+			continue;
+		}
+		tss.len -= ret;
+		spliced += ret;
+
+		if (!timeo)
+			break;
+		release_sock(sk);
+		lock_sock(sk);
+
+		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
+		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
+		    signal_pending(current))
+			break;
+	}
+
+	release_sock(sk);
+
+	if (spliced)
+		return spliced;
+
+	return ret;
+}
+
+struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
+{
+	struct sk_buff *skb;
+
+	/* The TCP header must be at least 32-bit aligned.  */
+	size = ALIGN(size, 4);
+
+	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
+	if (skb) {
+		if (sk_wmem_schedule(sk, skb->truesize)) {
+			/*
+			 * Make sure that we have exactly size bytes
+			 * available to the caller, no more, no less.
+			 */
+			skb_reserve(skb, skb_tailroom(skb) - size);
+			return skb;
+		}
+		__kfree_skb(skb);
+	} else {
+		sk->sk_prot->enter_memory_pressure(sk);
+		sk_stream_moderate_sndbuf(sk);
+	}
+	return NULL;
+}
+
+static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
+			 size_t psize, int flags)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int mss_now, size_goal;
+	int err;
+	ssize_t copied;
+	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+
+	/* Wait for a connection to finish. */
+	if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
+		if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
+			goto out_err;
+
+	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+	mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+	size_goal = tp->xmit_size_goal;
+	copied = 0;
+
+	err = -EPIPE;
+	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+		goto do_error;
+
+	while (psize > 0) {
+		struct sk_buff *skb = tcp_write_queue_tail(sk);
+		struct page *page = pages[poffset / PAGE_SIZE];
+		int copy, i, can_coalesce;
+		int offset = poffset % PAGE_SIZE;
+		int size = min_t(size_t, psize, PAGE_SIZE - offset);
+
+		if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
+new_segment:
+			if (!sk_stream_memory_free(sk))
+				goto wait_for_sndbuf;
+
+			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
+			if (!skb)
+				goto wait_for_memory;
+
+			skb_entail(sk, skb);
+			copy = size_goal;
+		}
+
+		if (copy > size)
+			copy = size;
+
+		i = skb_shinfo(skb)->nr_frags;
+		can_coalesce = skb_can_coalesce(skb, i, page, offset);
+		if (!can_coalesce && i >= MAX_SKB_FRAGS) {
+			tcp_mark_push(tp, skb);
+			goto new_segment;
+		}
+		if (!sk_wmem_schedule(sk, copy))
+			goto wait_for_memory;
+
+		if (can_coalesce) {
+			skb_shinfo(skb)->frags[i - 1].size += copy;
+		} else {
+			get_page(page);
+			skb_fill_page_desc(skb, i, page, offset, copy);
+		}
+
+		skb->len += copy;
+		skb->data_len += copy;
+		skb->truesize += copy;
+		sk->sk_wmem_queued += copy;
+		sk_mem_charge(sk, copy);
+		skb->ip_summed = CHECKSUM_PARTIAL;
+		tp->write_seq += copy;
+		TCP_SKB_CB(skb)->end_seq += copy;
+		skb_shinfo(skb)->gso_segs = 0;
+
+		if (!copied)
+			TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
+
+		copied += copy;
+		poffset += copy;
+		if (!(psize -= copy))
+			goto out;
+
+		if (skb->len < size_goal || (flags & MSG_OOB))
+			continue;
+
+		if (forced_push(tp)) {
+			tcp_mark_push(tp, skb);
+			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
+		} else if (skb == tcp_send_head(sk))
+			tcp_push_one(sk, mss_now);
+		continue;
+
+wait_for_sndbuf:
+		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+wait_for_memory:
+		if (copied)
+			tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
+
+		if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
+			goto do_error;
+
+		mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+		size_goal = tp->xmit_size_goal;
+	}
+
+out:
+	if (copied)
+		tcp_push(sk, flags, mss_now, tp->nonagle);
+	return copied;
+
+do_error:
+	if (copied)
+		goto out;
+out_err:
+	return sk_stream_error(sk, flags, err);
+}
+
+ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
+		     size_t size, int flags)
+{
+	ssize_t res;
+	struct sock *sk = sock->sk;
+
+	if (!(sk->sk_route_caps & NETIF_F_SG) ||
+	    !(sk->sk_route_caps & NETIF_F_ALL_CSUM))
+		return sock_no_sendpage(sock, page, offset, size, flags);
+
+	lock_sock(sk);
+	TCP_CHECK_TIMER(sk);
+	res = do_tcp_sendpages(sk, &page, offset, size, flags);
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return res;
+}
+
+#define TCP_PAGE(sk)	(sk->sk_sndmsg_page)
+#define TCP_OFF(sk)	(sk->sk_sndmsg_off)
+
+static inline int select_size(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int tmp = tp->mss_cache;
+
+	if (sk->sk_route_caps & NETIF_F_SG) {
+		if (sk_can_gso(sk))
+			tmp = 0;
+		else {
+			int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
+
+			if (tmp >= pgbreak &&
+			    tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
+				tmp = pgbreak;
+		}
+	}
+
+	return tmp;
+}
+
+int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
+		size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct iovec *iov;
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	int iovlen, flags;
+	int mss_now, size_goal;
+	int err, copied;
+	long timeo;
+
+	lock_sock(sk);
+	TCP_CHECK_TIMER(sk);
+
+	flags = msg->msg_flags;
+	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+
+	/* Wait for a connection to finish. */
+	if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
+		if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
+			goto out_err;
+
+	/* This should be in poll */
+	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+	mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+	size_goal = tp->xmit_size_goal;
+
+	/* Ok commence sending. */
+	iovlen = msg->msg_iovlen;
+	iov = msg->msg_iov;
+	copied = 0;
+
+	err = -EPIPE;
+	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+		goto do_error;
+
+	while (--iovlen >= 0) {
+		int seglen = iov->iov_len;
+		unsigned char __user *from = iov->iov_base;
+
+		iov++;
+
+		while (seglen > 0) {
+			int copy;
+
+			skb = tcp_write_queue_tail(sk);
+
+			if (!tcp_send_head(sk) ||
+			    (copy = size_goal - skb->len) <= 0) {
+
+new_segment:
+				/* Allocate new segment. If the interface is SG,
+				 * allocate skb fitting to single page.
+				 */
+				if (!sk_stream_memory_free(sk))
+					goto wait_for_sndbuf;
+
+				skb = sk_stream_alloc_skb(sk, select_size(sk),
+						sk->sk_allocation);
+				if (!skb)
+					goto wait_for_memory;
+
+				/*
+				 * Check whether we can use HW checksum.
+				 */
+				if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
+					skb->ip_summed = CHECKSUM_PARTIAL;
+
+				skb_entail(sk, skb);
+				copy = size_goal;
+			}
+
+			/* Try to append data to the end of skb. */
+			if (copy > seglen)
+				copy = seglen;
+
+			/* Where to copy to? */
+			if (skb_tailroom(skb) > 0) {
+				/* We have some space in skb head. Superb! */
+				if (copy > skb_tailroom(skb))
+					copy = skb_tailroom(skb);
+				if ((err = skb_add_data(skb, from, copy)) != 0)
+					goto do_fault;
+			} else {
+				int merge = 0;
+				int i = skb_shinfo(skb)->nr_frags;
+				struct page *page = TCP_PAGE(sk);
+				int off = TCP_OFF(sk);
+
+				if (skb_can_coalesce(skb, i, page, off) &&
+				    off != PAGE_SIZE) {
+					/* We can extend the last page
+					 * fragment. */
+					merge = 1;
+				} else if (i == MAX_SKB_FRAGS ||
+					   (!i &&
+					   !(sk->sk_route_caps & NETIF_F_SG))) {
+					/* Need to add new fragment and cannot
+					 * do this because interface is non-SG,
+					 * or because all the page slots are
+					 * busy. */
+					tcp_mark_push(tp, skb);
+					goto new_segment;
+				} else if (page) {
+					if (off == PAGE_SIZE) {
+						put_page(page);
+						TCP_PAGE(sk) = page = NULL;
+						off = 0;
+					}
+				} else
+					off = 0;
+
+				if (copy > PAGE_SIZE - off)
+					copy = PAGE_SIZE - off;
+
+				if (!sk_wmem_schedule(sk, copy))
+					goto wait_for_memory;
+
+				if (!page) {
+					/* Allocate new cache page. */
+					if (!(page = sk_stream_alloc_page(sk)))
+						goto wait_for_memory;
+				}
+
+				/* Time to copy data. We are close to
+				 * the end! */
+				err = skb_copy_to_page(sk, from, skb, page,
+						       off, copy);
+				if (err) {
+					/* If this page was new, give it to the
+					 * socket so it does not get leaked.
+					 */
+					if (!TCP_PAGE(sk)) {
+						TCP_PAGE(sk) = page;
+						TCP_OFF(sk) = 0;
+					}
+					goto do_error;
+				}
+
+				/* Update the skb. */
+				if (merge) {
+					skb_shinfo(skb)->frags[i - 1].size +=
+									copy;
+				} else {
+					skb_fill_page_desc(skb, i, page, off, copy);
+					if (TCP_PAGE(sk)) {
+						get_page(page);
+					} else if (off + copy < PAGE_SIZE) {
+						get_page(page);
+						TCP_PAGE(sk) = page;
+					}
+				}
+
+				TCP_OFF(sk) = off + copy;
+			}
+
+			if (!copied)
+				TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
+
+			tp->write_seq += copy;
+			TCP_SKB_CB(skb)->end_seq += copy;
+			skb_shinfo(skb)->gso_segs = 0;
+
+			from += copy;
+			copied += copy;
+			if ((seglen -= copy) == 0 && iovlen == 0)
+				goto out;
+
+			if (skb->len < size_goal || (flags & MSG_OOB))
+				continue;
+
+			if (forced_push(tp)) {
+				tcp_mark_push(tp, skb);
+				__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
+			} else if (skb == tcp_send_head(sk))
+				tcp_push_one(sk, mss_now);
+			continue;
+
+wait_for_sndbuf:
+			set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+wait_for_memory:
+			if (copied)
+				tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
+
+			if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
+				goto do_error;
+
+			mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+			size_goal = tp->xmit_size_goal;
+		}
+	}
+
+out:
+	if (copied)
+		tcp_push(sk, flags, mss_now, tp->nonagle);
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return copied;
+
+do_fault:
+	if (!skb->len) {
+		tcp_unlink_write_queue(skb, sk);
+		/* It is the one place in all of TCP, except connection
+		 * reset, where we can be unlinking the send_head.
+		 */
+		tcp_check_send_head(sk, skb);
+		sk_wmem_free_skb(sk, skb);
+	}
+
+do_error:
+	if (copied)
+		goto out;
+out_err:
+	err = sk_stream_error(sk, flags, err);
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return err;
+}
+
+/*
+ *	Handle reading urgent data. BSD has very simple semantics for
+ *	this, no blocking and very strange errors 8)
+ */
+
+static int tcp_recv_urg(struct sock *sk, long timeo,
+			struct msghdr *msg, int len, int flags,
+			int *addr_len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* No URG data to read. */
+	if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
+	    tp->urg_data == TCP_URG_READ)
+		return -EINVAL;	/* Yes this is right ! */
+
+	if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
+		return -ENOTCONN;
+
+	if (tp->urg_data & TCP_URG_VALID) {
+		int err = 0;
+		char c = tp->urg_data;
+
+		if (!(flags & MSG_PEEK))
+			tp->urg_data = TCP_URG_READ;
+
+		/* Read urgent data. */
+		msg->msg_flags |= MSG_OOB;
+
+		if (len > 0) {
+			if (!(flags & MSG_TRUNC))
+				err = memcpy_toiovec(msg->msg_iov, &c, 1);
+			len = 1;
+		} else
+			msg->msg_flags |= MSG_TRUNC;
+
+		return err ? -EFAULT : len;
+	}
+
+	if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
+		return 0;
+
+	/* Fixed the recv(..., MSG_OOB) behaviour.  BSD docs and
+	 * the available implementations agree in this case:
+	 * this call should never block, independent of the
+	 * blocking state of the socket.
+	 * Mike <pall@rz.uni-karlsruhe.de>
+	 */
+	return -EAGAIN;
+}
+
+/* Clean up the receive buffer for full frames taken by the user,
+ * then send an ACK if necessary.  COPIED is the number of bytes
+ * tcp_recvmsg has given to the user so far, it speeds up the
+ * calculation of whether or not we must ACK for the sake of
+ * a window update.
+ */
+void tcp_cleanup_rbuf(struct sock *sk, int copied)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int time_to_ack = 0;
+
+#if TCP_DEBUG
+	struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
+
+	WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
+#endif
+
+	if (inet_csk_ack_scheduled(sk)) {
+		const struct inet_connection_sock *icsk = inet_csk(sk);
+		   /* Delayed ACKs frequently hit locked sockets during bulk
+		    * receive. */
+		if (icsk->icsk_ack.blocked ||
+		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
+		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
+		    /*
+		     * If this read emptied read buffer, we send ACK, if
+		     * connection is not bidirectional, user drained
+		     * receive buffer and there was a small segment
+		     * in queue.
+		     */
+		    (copied > 0 &&
+		     ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
+		      ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
+		       !icsk->icsk_ack.pingpong)) &&
+		      !atomic_read(&sk->sk_rmem_alloc)))
+			time_to_ack = 1;
+	}
+
+	/* We send an ACK if we can now advertise a non-zero window
+	 * which has been raised "significantly".
+	 *
+	 * Even if window raised up to infinity, do not send window open ACK
+	 * in states, where we will not receive more. It is useless.
+	 */
+	if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
+		__u32 rcv_window_now = tcp_receive_window(tp);
+
+		/* Optimize, __tcp_select_window() is not cheap. */
+		if (2*rcv_window_now <= tp->window_clamp) {
+			__u32 new_window = __tcp_select_window(sk);
+
+			/* Send ACK now, if this read freed lots of space
+			 * in our buffer. Certainly, new_window is new window.
+			 * We can advertise it now, if it is not less than current one.
+			 * "Lots" means "at least twice" here.
+			 */
+			if (new_window && new_window >= 2 * rcv_window_now)
+				time_to_ack = 1;
+		}
+	}
+	if (time_to_ack)
+		tcp_send_ack(sk);
+}
+
+static void tcp_prequeue_process(struct sock *sk)
+{
+	struct sk_buff *skb;
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
+
+	/* RX process wants to run with disabled BHs, though it is not
+	 * necessary */
+	local_bh_disable();
+	while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
+		sk_backlog_rcv(sk, skb);
+	local_bh_enable();
+
+	/* Clear memory counter. */
+	tp->ucopy.memory = 0;
+}
+
+static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
+{
+	struct sk_buff *skb;
+	u32 offset;
+
+	skb_queue_walk(&sk->sk_receive_queue, skb) {
+		offset = seq - TCP_SKB_CB(skb)->seq;
+		if (tcp_hdr(skb)->syn)
+			offset--;
+		if (offset < skb->len || tcp_hdr(skb)->fin) {
+			*off = offset;
+			return skb;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * This routine provides an alternative to tcp_recvmsg() for routines
+ * that would like to handle copying from skbuffs directly in 'sendfile'
+ * fashion.
+ * Note:
+ *	- It is assumed that the socket was locked by the caller.
+ *	- The routine does not block.
+ *	- At present, there is no support for reading OOB data
+ *	  or for 'peeking' the socket using this routine
+ *	  (although both would be easy to implement).
+ */
+int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
+		  sk_read_actor_t recv_actor)
+{
+	struct sk_buff *skb;
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 seq = tp->copied_seq;
+	u32 offset;
+	int copied = 0;
+
+	if (sk->sk_state == TCP_LISTEN)
+		return -ENOTCONN;
+	while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
+		if (offset < skb->len) {
+			int used;
+			size_t len;
+
+			len = skb->len - offset;
+			/* Stop reading if we hit a patch of urgent data */
+			if (tp->urg_data) {
+				u32 urg_offset = tp->urg_seq - seq;
+				if (urg_offset < len)
+					len = urg_offset;
+				if (!len)
+					break;
+			}
+			used = recv_actor(desc, skb, offset, len);
+			if (used < 0) {
+				if (!copied)
+					copied = used;
+				break;
+			} else if (used <= len) {
+				seq += used;
+				copied += used;
+				offset += used;
+			}
+			/*
+			 * If recv_actor drops the lock (e.g. TCP splice
+			 * receive) the skb pointer might be invalid when
+			 * getting here: tcp_collapse might have deleted it
+			 * while aggregating skbs from the socket queue.
+			 */
+			skb = tcp_recv_skb(sk, seq-1, &offset);
+			if (!skb || (offset+1 != skb->len))
+				break;
+		}
+		if (tcp_hdr(skb)->fin) {
+			sk_eat_skb(sk, skb, 0);
+			++seq;
+			break;
+		}
+		sk_eat_skb(sk, skb, 0);
+		if (!desc->count)
+			break;
+	}
+	tp->copied_seq = seq;
+
+	tcp_rcv_space_adjust(sk);
+
+	/* Clean up data we have read: This will do ACK frames. */
+	if (copied > 0)
+		tcp_cleanup_rbuf(sk, copied);
+	return copied;
+}
+
+/*
+ *	This routine copies from a sock struct into the user buffer.
+ *
+ *	Technical note: in 2.3 we work on _locked_ socket, so that
+ *	tricks with *seq access order and skb->users are not required.
+ *	Probably, code can be easily improved even more.
+ */
+
+int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		size_t len, int nonblock, int flags, int *addr_len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int copied = 0;
+	u32 peek_seq;
+	u32 *seq;
+	unsigned long used;
+	int err;
+	int target;		/* Read at least this many bytes */
+	long timeo;
+	struct task_struct *user_recv = NULL;
+	int copied_early = 0;
+	struct sk_buff *skb;
+
+	lock_sock(sk);
+
+	TCP_CHECK_TIMER(sk);
+
+	err = -ENOTCONN;
+	if (sk->sk_state == TCP_LISTEN)
+		goto out;
+
+	timeo = sock_rcvtimeo(sk, nonblock);
+
+	/* Urgent data needs to be handled specially. */
+	if (flags & MSG_OOB)
+		goto recv_urg;
+
+	seq = &tp->copied_seq;
+	if (flags & MSG_PEEK) {
+		peek_seq = tp->copied_seq;
+		seq = &peek_seq;
+	}
+
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
+
+#ifdef CONFIG_NET_DMA
+	tp->ucopy.dma_chan = NULL;
+	preempt_disable();
+	skb = skb_peek_tail(&sk->sk_receive_queue);
+	{
+		int available = 0;
+
+		if (skb)
+			available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
+		if ((available < target) &&
+		    (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
+		    !sysctl_tcp_low_latency &&
+		    __get_cpu_var(softnet_data).net_dma) {
+			preempt_enable_no_resched();
+			tp->ucopy.pinned_list =
+					dma_pin_iovec_pages(msg->msg_iov, len);
+		} else {
+			preempt_enable_no_resched();
+		}
+	}
+#endif
+
+	do {
+		u32 offset;
+
+		/* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
+		if (tp->urg_data && tp->urg_seq == *seq) {
+			if (copied)
+				break;
+			if (signal_pending(current)) {
+				copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
+				break;
+			}
+		}
+
+		/* Next get a buffer. */
+
+		skb = skb_peek(&sk->sk_receive_queue);
+		do {
+			if (!skb)
+				break;
+
+			/* Now that we have two receive queues this
+			 * shouldn't happen.
+			 */
+			if (before(*seq, TCP_SKB_CB(skb)->seq)) {
+				printk(KERN_INFO "recvmsg bug: copied %X "
+				       "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
+				break;
+			}
+			offset = *seq - TCP_SKB_CB(skb)->seq;
+			if (tcp_hdr(skb)->syn)
+				offset--;
+			if (offset < skb->len)
+				goto found_ok_skb;
+			if (tcp_hdr(skb)->fin)
+				goto found_fin_ok;
+			WARN_ON(!(flags & MSG_PEEK));
+			skb = skb->next;
+		} while (skb != (struct sk_buff *)&sk->sk_receive_queue);
+
+		/* Well, if we have backlog, try to process it now yet. */
+
+		if (copied >= target && !sk->sk_backlog.tail)
+			break;
+
+		if (copied) {
+			if (sk->sk_err ||
+			    sk->sk_state == TCP_CLOSE ||
+			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
+			    !timeo ||
+			    signal_pending(current))
+				break;
+		} else {
+			if (sock_flag(sk, SOCK_DONE))
+				break;
+
+			if (sk->sk_err) {
+				copied = sock_error(sk);
+				break;
+			}
+
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
+				break;
+
+			if (sk->sk_state == TCP_CLOSE) {
+				if (!sock_flag(sk, SOCK_DONE)) {
+					/* This occurs when user tries to read
+					 * from never connected socket.
+					 */
+					copied = -ENOTCONN;
+					break;
+				}
+				break;
+			}
+
+			if (!timeo) {
+				copied = -EAGAIN;
+				break;
+			}
+
+			if (signal_pending(current)) {
+				copied = sock_intr_errno(timeo);
+				break;
+			}
+		}
+
+		tcp_cleanup_rbuf(sk, copied);
+
+		if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
+			/* Install new reader */
+			if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
+				user_recv = current;
+				tp->ucopy.task = user_recv;
+				tp->ucopy.iov = msg->msg_iov;
+			}
+
+			tp->ucopy.len = len;
+
+			WARN_ON(tp->copied_seq != tp->rcv_nxt &&
+				!(flags & (MSG_PEEK | MSG_TRUNC)));
+
+			/* Ugly... If prequeue is not empty, we have to
+			 * process it before releasing socket, otherwise
+			 * order will be broken at second iteration.
+			 * More elegant solution is required!!!
+			 *
+			 * Look: we have the following (pseudo)queues:
+			 *
+			 * 1. packets in flight
+			 * 2. backlog
+			 * 3. prequeue
+			 * 4. receive_queue
+			 *
+			 * Each queue can be processed only if the next ones
+			 * are empty. At this point we have empty receive_queue.
+			 * But prequeue _can_ be not empty after 2nd iteration,
+			 * when we jumped to start of loop because backlog
+			 * processing added something to receive_queue.
+			 * We cannot release_sock(), because backlog contains
+			 * packets arrived _after_ prequeued ones.
+			 *
+			 * Shortly, algorithm is clear --- to process all
+			 * the queues in order. We could make it more directly,
+			 * requeueing packets from backlog to prequeue, if
+			 * is not empty. It is more elegant, but eats cycles,
+			 * unfortunately.
+			 */
+			if (!skb_queue_empty(&tp->ucopy.prequeue))
+				goto do_prequeue;
+
+			/* __ Set realtime policy in scheduler __ */
+		}
+
+		if (copied >= target) {
+			/* Do not sleep, just process backlog. */
+			release_sock(sk);
+			lock_sock(sk);
+		} else
+			sk_wait_data(sk, &timeo);
+
+#ifdef CONFIG_NET_DMA
+		tp->ucopy.wakeup = 0;
+#endif
+
+		if (user_recv) {
+			int chunk;
+
+			/* __ Restore normal policy in scheduler __ */
+
+			if ((chunk = len - tp->ucopy.len) != 0) {
+				NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
+				len -= chunk;
+				copied += chunk;
+			}
+
+			if (tp->rcv_nxt == tp->copied_seq &&
+			    !skb_queue_empty(&tp->ucopy.prequeue)) {
+do_prequeue:
+				tcp_prequeue_process(sk);
+
+				if ((chunk = len - tp->ucopy.len) != 0) {
+					NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
+					len -= chunk;
+					copied += chunk;
+				}
+			}
+		}
+		if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
+			if (net_ratelimit())
+				printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
+				       current->comm, task_pid_nr(current));
+			peek_seq = tp->copied_seq;
+		}
+		continue;
+
+	found_ok_skb:
+		/* Ok so how much can we use? */
+		used = skb->len - offset;
+		if (len < used)
+			used = len;
+
+		/* Do we have urgent data here? */
+		if (tp->urg_data) {
+			u32 urg_offset = tp->urg_seq - *seq;
+			if (urg_offset < used) {
+				if (!urg_offset) {
+					if (!sock_flag(sk, SOCK_URGINLINE)) {
+						++*seq;
+						offset++;
+						used--;
+						if (!used)
+							goto skip_copy;
+					}
+				} else
+					used = urg_offset;
+			}
+		}
+
+		if (!(flags & MSG_TRUNC)) {
+#ifdef CONFIG_NET_DMA
+			if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
+				tp->ucopy.dma_chan = get_softnet_dma();
+
+			if (tp->ucopy.dma_chan) {
+				tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
+					tp->ucopy.dma_chan, skb, offset,
+					msg->msg_iov, used,
+					tp->ucopy.pinned_list);
+
+				if (tp->ucopy.dma_cookie < 0) {
+
+					printk(KERN_ALERT "dma_cookie < 0\n");
+
+					/* Exception. Bailout! */
+					if (!copied)
+						copied = -EFAULT;
+					break;
+				}
+				if ((offset + used) == skb->len)
+					copied_early = 1;
+
+			} else
+#endif
+			{
+				err = skb_copy_datagram_iovec(skb, offset,
+						msg->msg_iov, used);
+				if (err) {
+					/* Exception. Bailout! */
+					if (!copied)
+						copied = -EFAULT;
+					break;
+				}
+			}
+		}
+
+		*seq += used;
+		copied += used;
+		len -= used;
+
+		tcp_rcv_space_adjust(sk);
+
+skip_copy:
+		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
+			tp->urg_data = 0;
+			tcp_fast_path_check(sk);
+		}
+		if (used + offset < skb->len)
+			continue;
+
+		if (tcp_hdr(skb)->fin)
+			goto found_fin_ok;
+		if (!(flags & MSG_PEEK)) {
+			sk_eat_skb(sk, skb, copied_early);
+			copied_early = 0;
+		}
+		continue;
+
+	found_fin_ok:
+		/* Process the FIN. */
+		++*seq;
+		if (!(flags & MSG_PEEK)) {
+			sk_eat_skb(sk, skb, copied_early);
+			copied_early = 0;
+		}
+		break;
+	} while (len > 0);
+
+	if (user_recv) {
+		if (!skb_queue_empty(&tp->ucopy.prequeue)) {
+			int chunk;
+
+			tp->ucopy.len = copied > 0 ? len : 0;
+
+			tcp_prequeue_process(sk);
+
+			if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
+				NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
+				len -= chunk;
+				copied += chunk;
+			}
+		}
+
+		tp->ucopy.task = NULL;
+		tp->ucopy.len = 0;
+	}
+
+#ifdef CONFIG_NET_DMA
+	if (tp->ucopy.dma_chan) {
+		dma_cookie_t done, used;
+
+		dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
+
+		while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
+						 tp->ucopy.dma_cookie, &done,
+						 &used) == DMA_IN_PROGRESS) {
+			/* do partial cleanup of sk_async_wait_queue */
+			while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
+			       (dma_async_is_complete(skb->dma_cookie, done,
+						      used) == DMA_SUCCESS)) {
+				__skb_dequeue(&sk->sk_async_wait_queue);
+				kfree_skb(skb);
+			}
+		}
+
+		/* Safe to free early-copied skbs now */
+		__skb_queue_purge(&sk->sk_async_wait_queue);
+		dma_chan_put(tp->ucopy.dma_chan);
+		tp->ucopy.dma_chan = NULL;
+	}
+	if (tp->ucopy.pinned_list) {
+		dma_unpin_iovec_pages(tp->ucopy.pinned_list);
+		tp->ucopy.pinned_list = NULL;
+	}
+#endif
+
+	/* According to UNIX98, msg_name/msg_namelen are ignored
+	 * on connected socket. I was just happy when found this 8) --ANK
+	 */
+
+	/* Clean up data we have read: This will do ACK frames. */
+	tcp_cleanup_rbuf(sk, copied);
+
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return copied;
+
+out:
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return err;
+
+recv_urg:
+	err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
+	goto out;
+}
+
+void tcp_set_state(struct sock *sk, int state)
+{
+	int oldstate = sk->sk_state;
+
+	switch (state) {
+	case TCP_ESTABLISHED:
+		if (oldstate != TCP_ESTABLISHED)
+			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
+		break;
+
+	case TCP_CLOSE:
+		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
+			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
+
+		sk->sk_prot->unhash(sk);
+		if (inet_csk(sk)->icsk_bind_hash &&
+		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
+			inet_put_port(sk);
+		/* fall through */
+	default:
+		if (oldstate==TCP_ESTABLISHED)
+			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
+	}
+
+	/* Change state AFTER socket is unhashed to avoid closed
+	 * socket sitting in hash tables.
+	 */
+	sk->sk_state = state;
+
+#ifdef STATE_TRACE
+	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
+#endif
+}
+EXPORT_SYMBOL_GPL(tcp_set_state);
+
+/*
+ *	State processing on a close. This implements the state shift for
+ *	sending our FIN frame. Note that we only send a FIN for some
+ *	states. A shutdown() may have already sent the FIN, or we may be
+ *	closed.
+ */
+
+static const unsigned char new_state[16] = {
+  /* current state:        new state:      action:	*/
+  /* (Invalid)		*/ TCP_CLOSE,
+  /* TCP_ESTABLISHED	*/ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
+  /* TCP_SYN_SENT	*/ TCP_CLOSE,
+  /* TCP_SYN_RECV	*/ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
+  /* TCP_FIN_WAIT1	*/ TCP_FIN_WAIT1,
+  /* TCP_FIN_WAIT2	*/ TCP_FIN_WAIT2,
+  /* TCP_TIME_WAIT	*/ TCP_CLOSE,
+  /* TCP_CLOSE		*/ TCP_CLOSE,
+  /* TCP_CLOSE_WAIT	*/ TCP_LAST_ACK  | TCP_ACTION_FIN,
+  /* TCP_LAST_ACK	*/ TCP_LAST_ACK,
+  /* TCP_LISTEN		*/ TCP_CLOSE,
+  /* TCP_CLOSING	*/ TCP_CLOSING,
+};
+
+static int tcp_close_state(struct sock *sk)
+{
+	int next = (int)new_state[sk->sk_state];
+	int ns = next & TCP_STATE_MASK;
+
+	tcp_set_state(sk, ns);
+
+	return next & TCP_ACTION_FIN;
+}
+
+/*
+ *	Shutdown the sending side of a connection. Much like close except
+ *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
+ */
+
+void tcp_shutdown(struct sock *sk, int how)
+{
+	/*	We need to grab some memory, and put together a FIN,
+	 *	and then put it into the queue to be sent.
+	 *		Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
+	 */
+	if (!(how & SEND_SHUTDOWN))
+		return;
+
+	/* If we've already sent a FIN, or it's a closed state, skip this. */
+	if ((1 << sk->sk_state) &
+	    (TCPF_ESTABLISHED | TCPF_SYN_SENT |
+	     TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
+		/* Clear out any half completed packets.  FIN if needed. */
+		if (tcp_close_state(sk))
+			tcp_send_fin(sk);
+	}
+}
+
+void tcp_close(struct sock *sk, long timeout)
+{
+	struct sk_buff *skb;
+	int data_was_unread = 0;
+	int state;
+
+	lock_sock(sk);
+	sk->sk_shutdown = SHUTDOWN_MASK;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		tcp_set_state(sk, TCP_CLOSE);
+
+		/* Special case. */
+		inet_csk_listen_stop(sk);
+
+		goto adjudge_to_death;
+	}
+
+	/*  We need to flush the recv. buffs.  We do this only on the
+	 *  descriptor close, not protocol-sourced closes, because the
+	 *  reader process may not have drained the data yet!
+	 */
+	while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+		u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
+			  tcp_hdr(skb)->fin;
+		data_was_unread += len;
+		__kfree_skb(skb);
+	}
+
+	sk_mem_reclaim(sk);
+
+	/* As outlined in RFC 2525, section 2.17, we send a RST here because
+	 * data was lost. To witness the awful effects of the old behavior of
+	 * always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
+	 * GET in an FTP client, suspend the process, wait for the client to
+	 * advertise a zero window, then kill -9 the FTP client, wheee...
+	 * Note: timeout is always zero in such a case.
+	 */
+	if (data_was_unread) {
+		/* Unread data was tossed, zap the connection. */
+		NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
+		tcp_set_state(sk, TCP_CLOSE);
+		tcp_send_active_reset(sk, GFP_KERNEL);
+	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
+		/* Check zero linger _after_ checking for unread data. */
+		sk->sk_prot->disconnect(sk, 0);
+		NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
+	} else if (tcp_close_state(sk)) {
+		/* We FIN if the application ate all the data before
+		 * zapping the connection.
+		 */
+
+		/* RED-PEN. Formally speaking, we have broken TCP state
+		 * machine. State transitions:
+		 *
+		 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
+		 * TCP_SYN_RECV	-> TCP_FIN_WAIT1 (forget it, it's impossible)
+		 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
+		 *
+		 * are legal only when FIN has been sent (i.e. in window),
+		 * rather than queued out of window. Purists blame.
+		 *
+		 * F.e. "RFC state" is ESTABLISHED,
+		 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
+		 *
+		 * The visible declinations are that sometimes
+		 * we enter time-wait state, when it is not required really
+		 * (harmless), do not send active resets, when they are
+		 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
+		 * they look as CLOSING or LAST_ACK for Linux)
+		 * Probably, I missed some more holelets.
+		 * 						--ANK
+		 */
+		tcp_send_fin(sk);
+	}
+
+	sk_stream_wait_close(sk, timeout);
+
+adjudge_to_death:
+	state = sk->sk_state;
+	sock_hold(sk);
+	sock_orphan(sk);
+	atomic_inc(sk->sk_prot->orphan_count);
+
+	/* It is the last release_sock in its life. It will remove backlog. */
+	release_sock(sk);
+
+
+	/* Now socket is owned by kernel and we acquire BH lock
+	   to finish close. No need to check for user refs.
+	 */
+	local_bh_disable();
+	bh_lock_sock(sk);
+	WARN_ON(sock_owned_by_user(sk));
+
+	/* Have we already been destroyed by a softirq or backlog? */
+	if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
+		goto out;
+
+	/*	This is a (useful) BSD violating of the RFC. There is a
+	 *	problem with TCP as specified in that the other end could
+	 *	keep a socket open forever with no application left this end.
+	 *	We use a 3 minute timeout (about the same as BSD) then kill
+	 *	our end. If they send after that then tough - BUT: long enough
+	 *	that we won't make the old 4*rto = almost no time - whoops
+	 *	reset mistake.
+	 *
+	 *	Nope, it was not mistake. It is really desired behaviour
+	 *	f.e. on http servers, when such sockets are useless, but
+	 *	consume significant resources. Let's do it with special
+	 *	linger2	option.					--ANK
+	 */
+
+	if (sk->sk_state == TCP_FIN_WAIT2) {
+		struct tcp_sock *tp = tcp_sk(sk);
+		if (tp->linger2 < 0) {
+			tcp_set_state(sk, TCP_CLOSE);
+			tcp_send_active_reset(sk, GFP_ATOMIC);
+			NET_INC_STATS_BH(sock_net(sk),
+					LINUX_MIB_TCPABORTONLINGER);
+		} else {
+			const int tmo = tcp_fin_time(sk);
+
+			if (tmo > TCP_TIMEWAIT_LEN) {
+				inet_csk_reset_keepalive_timer(sk,
+						tmo - TCP_TIMEWAIT_LEN);
+			} else {
+				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
+				goto out;
+			}
+		}
+	}
+	if (sk->sk_state != TCP_CLOSE) {
+		sk_mem_reclaim(sk);
+		if (tcp_too_many_orphans(sk,
+				atomic_read(sk->sk_prot->orphan_count))) {
+			if (net_ratelimit())
+				printk(KERN_INFO "TCP: too many of orphaned "
+				       "sockets\n");
+			tcp_set_state(sk, TCP_CLOSE);
+			tcp_send_active_reset(sk, GFP_ATOMIC);
+			NET_INC_STATS_BH(sock_net(sk),
+					LINUX_MIB_TCPABORTONMEMORY);
+		}
+	}
+
+	if (sk->sk_state == TCP_CLOSE)
+		inet_csk_destroy_sock(sk);
+	/* Otherwise, socket is reprieved until protocol close. */
+
+out:
+	bh_unlock_sock(sk);
+	local_bh_enable();
+	sock_put(sk);
+}
+
+/* These states need RST on ABORT according to RFC793 */
+
+static inline int tcp_need_reset(int state)
+{
+	return (1 << state) &
+	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
+		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
+}
+
+int tcp_disconnect(struct sock *sk, int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int err = 0;
+	int old_state = sk->sk_state;
+
+	if (old_state != TCP_CLOSE)
+		tcp_set_state(sk, TCP_CLOSE);
+
+	/* ABORT function of RFC793 */
+	if (old_state == TCP_LISTEN) {
+		inet_csk_listen_stop(sk);
+	} else if (tcp_need_reset(old_state) ||
+		   (tp->snd_nxt != tp->write_seq &&
+		    (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
+		/* The last check adjusts for discrepancy of Linux wrt. RFC
+		 * states
+		 */
+		tcp_send_active_reset(sk, gfp_any());
+		sk->sk_err = ECONNRESET;
+	} else if (old_state == TCP_SYN_SENT)
+		sk->sk_err = ECONNRESET;
+
+	tcp_clear_xmit_timers(sk);
+	__skb_queue_purge(&sk->sk_receive_queue);
+	tcp_write_queue_purge(sk);
+	__skb_queue_purge(&tp->out_of_order_queue);
+#ifdef CONFIG_NET_DMA
+	__skb_queue_purge(&sk->sk_async_wait_queue);
+#endif
+
+	inet->dport = 0;
+
+	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
+		inet_reset_saddr(sk);
+
+	sk->sk_shutdown = 0;
+	sock_reset_flag(sk, SOCK_DONE);
+	tp->srtt = 0;
+	if ((tp->write_seq += tp->max_window + 2) == 0)
+		tp->write_seq = 1;
+	icsk->icsk_backoff = 0;
+	tp->snd_cwnd = 2;
+	icsk->icsk_probes_out = 0;
+	tp->packets_out = 0;
+	tp->snd_ssthresh = 0x7fffffff;
+	tp->snd_cwnd_cnt = 0;
+	tp->bytes_acked = 0;
+	tcp_set_ca_state(sk, TCP_CA_Open);
+	tcp_clear_retrans(tp);
+	inet_csk_delack_init(sk);
+	tcp_init_send_head(sk);
+	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
+	__sk_dst_reset(sk);
+
+	WARN_ON(inet->num && !icsk->icsk_bind_hash);
+
+	sk->sk_error_report(sk);
+	return err;
+}
+
+/*
+ *	Socket option code for TCP.
+ */
+static int do_tcp_setsockopt(struct sock *sk, int level,
+		int optname, char __user *optval, int optlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int val;
+	int err = 0;
+
+	/* This is a string value all the others are int's */
+	if (optname == TCP_CONGESTION) {
+		char name[TCP_CA_NAME_MAX];
+
+		if (optlen < 1)
+			return -EINVAL;
+
+		val = strncpy_from_user(name, optval,
+					min(TCP_CA_NAME_MAX-1, optlen));
+		if (val < 0)
+			return -EFAULT;
+		name[val] = 0;
+
+		lock_sock(sk);
+		err = tcp_set_congestion_control(sk, name);
+		release_sock(sk);
+		return err;
+	}
+
+	if (optlen < sizeof(int))
+		return -EINVAL;
+
+	if (get_user(val, (int __user *)optval))
+		return -EFAULT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case TCP_MAXSEG:
+		/* Values greater than interface MTU won't take effect. However
+		 * at the point when this call is done we typically don't yet
+		 * know which interface is going to be used */
+		if (val < 8 || val > MAX_TCP_WINDOW) {
+			err = -EINVAL;
+			break;
+		}
+		tp->rx_opt.user_mss = val;
+		break;
+
+	case TCP_NODELAY:
+		if (val) {
+			/* TCP_NODELAY is weaker than TCP_CORK, so that
+			 * this option on corked socket is remembered, but
+			 * it is not activated until cork is cleared.
+			 *
+			 * However, when TCP_NODELAY is set we make
+			 * an explicit push, which overrides even TCP_CORK
+			 * for currently queued segments.
+			 */
+			tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
+			tcp_push_pending_frames(sk);
+		} else {
+			tp->nonagle &= ~TCP_NAGLE_OFF;
+		}
+		break;
+
+	case TCP_CORK:
+		/* When set indicates to always queue non-full frames.
+		 * Later the user clears this option and we transmit
+		 * any pending partial frames in the queue.  This is
+		 * meant to be used alongside sendfile() to get properly
+		 * filled frames when the user (for example) must write
+		 * out headers with a write() call first and then use
+		 * sendfile to send out the data parts.
+		 *
+		 * TCP_CORK can be set together with TCP_NODELAY and it is
+		 * stronger than TCP_NODELAY.
+		 */
+		if (val) {
+			tp->nonagle |= TCP_NAGLE_CORK;
+		} else {
+			tp->nonagle &= ~TCP_NAGLE_CORK;
+			if (tp->nonagle&TCP_NAGLE_OFF)
+				tp->nonagle |= TCP_NAGLE_PUSH;
+			tcp_push_pending_frames(sk);
+		}
+		break;
+
+	case TCP_KEEPIDLE:
+		if (val < 1 || val > MAX_TCP_KEEPIDLE)
+			err = -EINVAL;
+		else {
+			tp->keepalive_time = val * HZ;
+			if (sock_flag(sk, SOCK_KEEPOPEN) &&
+			    !((1 << sk->sk_state) &
+			      (TCPF_CLOSE | TCPF_LISTEN))) {
+				__u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
+				if (tp->keepalive_time > elapsed)
+					elapsed = tp->keepalive_time - elapsed;
+				else
+					elapsed = 0;
+				inet_csk_reset_keepalive_timer(sk, elapsed);
+			}
+		}
+		break;
+	case TCP_KEEPINTVL:
+		if (val < 1 || val > MAX_TCP_KEEPINTVL)
+			err = -EINVAL;
+		else
+			tp->keepalive_intvl = val * HZ;
+		break;
+	case TCP_KEEPCNT:
+		if (val < 1 || val > MAX_TCP_KEEPCNT)
+			err = -EINVAL;
+		else
+			tp->keepalive_probes = val;
+		break;
+	case TCP_SYNCNT:
+		if (val < 1 || val > MAX_TCP_SYNCNT)
+			err = -EINVAL;
+		else
+			icsk->icsk_syn_retries = val;
+		break;
+
+	case TCP_LINGER2:
+		if (val < 0)
+			tp->linger2 = -1;
+		else if (val > sysctl_tcp_fin_timeout / HZ)
+			tp->linger2 = 0;
+		else
+			tp->linger2 = val * HZ;
+		break;
+
+	case TCP_DEFER_ACCEPT:
+		icsk->icsk_accept_queue.rskq_defer_accept = 0;
+		if (val > 0) {
+			/* Translate value in seconds to number of
+			 * retransmits */
+			while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
+			       val > ((TCP_TIMEOUT_INIT / HZ) <<
+				       icsk->icsk_accept_queue.rskq_defer_accept))
+				icsk->icsk_accept_queue.rskq_defer_accept++;
+			icsk->icsk_accept_queue.rskq_defer_accept++;
+		}
+		break;
+
+	case TCP_WINDOW_CLAMP:
+		if (!val) {
+			if (sk->sk_state != TCP_CLOSE) {
+				err = -EINVAL;
+				break;
+			}
+			tp->window_clamp = 0;
+		} else
+			tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
+						SOCK_MIN_RCVBUF / 2 : val;
+		break;
+
+	case TCP_QUICKACK:
+		if (!val) {
+			icsk->icsk_ack.pingpong = 1;
+		} else {
+			icsk->icsk_ack.pingpong = 0;
+			if ((1 << sk->sk_state) &
+			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
+			    inet_csk_ack_scheduled(sk)) {
+				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
+				tcp_cleanup_rbuf(sk, 1);
+				if (!(val & 1))
+					icsk->icsk_ack.pingpong = 1;
+			}
+		}
+		break;
+
+#ifdef CONFIG_TCP_MD5SIG
+	case TCP_MD5SIG:
+		/* Read the IP->Key mappings from userspace */
+		err = tp->af_specific->md5_parse(sk, optval, optlen);
+		break;
+#endif
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	release_sock(sk);
+	return err;
+}
+
+int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
+		   int optlen)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (level != SOL_TCP)
+		return icsk->icsk_af_ops->setsockopt(sk, level, optname,
+						     optval, optlen);
+	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int optlen)
+{
+	if (level != SOL_TCP)
+		return inet_csk_compat_setsockopt(sk, level, optname,
+						  optval, optlen);
+	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
+}
+
+EXPORT_SYMBOL(compat_tcp_setsockopt);
+#endif
+
+/* Return information about state of tcp endpoint in API format. */
+void tcp_get_info(struct sock *sk, struct tcp_info *info)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	u32 now = tcp_time_stamp;
+
+	memset(info, 0, sizeof(*info));
+
+	info->tcpi_state = sk->sk_state;
+	info->tcpi_ca_state = icsk->icsk_ca_state;
+	info->tcpi_retransmits = icsk->icsk_retransmits;
+	info->tcpi_probes = icsk->icsk_probes_out;
+	info->tcpi_backoff = icsk->icsk_backoff;
+
+	if (tp->rx_opt.tstamp_ok)
+		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
+	if (tcp_is_sack(tp))
+		info->tcpi_options |= TCPI_OPT_SACK;
+	if (tp->rx_opt.wscale_ok) {
+		info->tcpi_options |= TCPI_OPT_WSCALE;
+		info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
+		info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
+	}
+
+	if (tp->ecn_flags&TCP_ECN_OK)
+		info->tcpi_options |= TCPI_OPT_ECN;
+
+	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
+	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
+	info->tcpi_snd_mss = tp->mss_cache;
+	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		info->tcpi_unacked = sk->sk_ack_backlog;
+		info->tcpi_sacked = sk->sk_max_ack_backlog;
+	} else {
+		info->tcpi_unacked = tp->packets_out;
+		info->tcpi_sacked = tp->sacked_out;
+	}
+	info->tcpi_lost = tp->lost_out;
+	info->tcpi_retrans = tp->retrans_out;
+	info->tcpi_fackets = tp->fackets_out;
+
+	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
+	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
+	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
+
+	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
+	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
+	info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
+	info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
+	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
+	info->tcpi_snd_cwnd = tp->snd_cwnd;
+	info->tcpi_advmss = tp->advmss;
+	info->tcpi_reordering = tp->reordering;
+
+	info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
+	info->tcpi_rcv_space = tp->rcvq_space.space;
+
+	info->tcpi_total_retrans = tp->total_retrans;
+}
+
+EXPORT_SYMBOL_GPL(tcp_get_info);
+
+static int do_tcp_getsockopt(struct sock *sk, int level,
+		int optname, char __user *optval, int __user *optlen)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int val, len;
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	len = min_t(unsigned int, len, sizeof(int));
+
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+	case TCP_MAXSEG:
+		val = tp->mss_cache;
+		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
+			val = tp->rx_opt.user_mss;
+		break;
+	case TCP_NODELAY:
+		val = !!(tp->nonagle&TCP_NAGLE_OFF);
+		break;
+	case TCP_CORK:
+		val = !!(tp->nonagle&TCP_NAGLE_CORK);
+		break;
+	case TCP_KEEPIDLE:
+		val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
+		break;
+	case TCP_KEEPINTVL:
+		val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
+		break;
+	case TCP_KEEPCNT:
+		val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
+		break;
+	case TCP_SYNCNT:
+		val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
+		break;
+	case TCP_LINGER2:
+		val = tp->linger2;
+		if (val >= 0)
+			val = (val ? : sysctl_tcp_fin_timeout) / HZ;
+		break;
+	case TCP_DEFER_ACCEPT:
+		val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
+			((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
+		break;
+	case TCP_WINDOW_CLAMP:
+		val = tp->window_clamp;
+		break;
+	case TCP_INFO: {
+		struct tcp_info info;
+
+		if (get_user(len, optlen))
+			return -EFAULT;
+
+		tcp_get_info(sk, &info);
+
+		len = min_t(unsigned int, len, sizeof(info));
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval, &info, len))
+			return -EFAULT;
+		return 0;
+	}
+	case TCP_QUICKACK:
+		val = !icsk->icsk_ack.pingpong;
+		break;
+
+	case TCP_CONGESTION:
+		if (get_user(len, optlen))
+			return -EFAULT;
+		len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
+			return -EFAULT;
+		return 0;
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	if (put_user(len, optlen))
+		return -EFAULT;
+	if (copy_to_user(optval, &val, len))
+		return -EFAULT;
+	return 0;
+}
+
+int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
+		   int __user *optlen)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (level != SOL_TCP)
+		return icsk->icsk_af_ops->getsockopt(sk, level, optname,
+						     optval, optlen);
+	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	if (level != SOL_TCP)
+		return inet_csk_compat_getsockopt(sk, level, optname,
+						  optval, optlen);
+	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
+}
+
+EXPORT_SYMBOL(compat_tcp_getsockopt);
+#endif
+
+struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
+{
+	struct sk_buff *segs = ERR_PTR(-EINVAL);
+	struct tcphdr *th;
+	unsigned thlen;
+	unsigned int seq;
+	__be32 delta;
+	unsigned int oldlen;
+	unsigned int len;
+
+	if (!pskb_may_pull(skb, sizeof(*th)))
+		goto out;
+
+	th = tcp_hdr(skb);
+	thlen = th->doff * 4;
+	if (thlen < sizeof(*th))
+		goto out;
+
+	if (!pskb_may_pull(skb, thlen))
+		goto out;
+
+	oldlen = (u16)~skb->len;
+	__skb_pull(skb, thlen);
+
+	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
+		/* Packet is from an untrusted source, reset gso_segs. */
+		int type = skb_shinfo(skb)->gso_type;
+		int mss;
+
+		if (unlikely(type &
+			     ~(SKB_GSO_TCPV4 |
+			       SKB_GSO_DODGY |
+			       SKB_GSO_TCP_ECN |
+			       SKB_GSO_TCPV6 |
+			       0) ||
+			     !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
+			goto out;
+
+		mss = skb_shinfo(skb)->gso_size;
+		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
+
+		segs = NULL;
+		goto out;
+	}
+
+	segs = skb_segment(skb, features);
+	if (IS_ERR(segs))
+		goto out;
+
+	len = skb_shinfo(skb)->gso_size;
+	delta = htonl(oldlen + (thlen + len));
+
+	skb = segs;
+	th = tcp_hdr(skb);
+	seq = ntohl(th->seq);
+
+	do {
+		th->fin = th->psh = 0;
+
+		th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
+				       (__force u32)delta));
+		if (skb->ip_summed != CHECKSUM_PARTIAL)
+			th->check =
+			     csum_fold(csum_partial(skb_transport_header(skb),
+						    thlen, skb->csum));
+
+		seq += len;
+		skb = skb->next;
+		th = tcp_hdr(skb);
+
+		th->seq = htonl(seq);
+		th->cwr = 0;
+	} while (skb->next);
+
+	delta = htonl(oldlen + (skb->tail - skb->transport_header) +
+		      skb->data_len);
+	th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
+				(__force u32)delta));
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		th->check = csum_fold(csum_partial(skb_transport_header(skb),
+						   thlen, skb->csum));
+
+out:
+	return segs;
+}
+EXPORT_SYMBOL(tcp_tso_segment);
+
+#ifdef CONFIG_TCP_MD5SIG
+static unsigned long tcp_md5sig_users;
+static struct tcp_md5sig_pool **tcp_md5sig_pool;
+static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
+
+static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
+{
+	int cpu;
+	for_each_possible_cpu(cpu) {
+		struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
+		if (p) {
+			if (p->md5_desc.tfm)
+				crypto_free_hash(p->md5_desc.tfm);
+			kfree(p);
+			p = NULL;
+		}
+	}
+	free_percpu(pool);
+}
+
+void tcp_free_md5sig_pool(void)
+{
+	struct tcp_md5sig_pool **pool = NULL;
+
+	spin_lock_bh(&tcp_md5sig_pool_lock);
+	if (--tcp_md5sig_users == 0) {
+		pool = tcp_md5sig_pool;
+		tcp_md5sig_pool = NULL;
+	}
+	spin_unlock_bh(&tcp_md5sig_pool_lock);
+	if (pool)
+		__tcp_free_md5sig_pool(pool);
+}
+
+EXPORT_SYMBOL(tcp_free_md5sig_pool);
+
+static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
+{
+	int cpu;
+	struct tcp_md5sig_pool **pool;
+
+	pool = alloc_percpu(struct tcp_md5sig_pool *);
+	if (!pool)
+		return NULL;
+
+	for_each_possible_cpu(cpu) {
+		struct tcp_md5sig_pool *p;
+		struct crypto_hash *hash;
+
+		p = kzalloc(sizeof(*p), GFP_KERNEL);
+		if (!p)
+			goto out_free;
+		*per_cpu_ptr(pool, cpu) = p;
+
+		hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
+		if (!hash || IS_ERR(hash))
+			goto out_free;
+
+		p->md5_desc.tfm = hash;
+	}
+	return pool;
+out_free:
+	__tcp_free_md5sig_pool(pool);
+	return NULL;
+}
+
+struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
+{
+	struct tcp_md5sig_pool **pool;
+	int alloc = 0;
+
+retry:
+	spin_lock_bh(&tcp_md5sig_pool_lock);
+	pool = tcp_md5sig_pool;
+	if (tcp_md5sig_users++ == 0) {
+		alloc = 1;
+		spin_unlock_bh(&tcp_md5sig_pool_lock);
+	} else if (!pool) {
+		tcp_md5sig_users--;
+		spin_unlock_bh(&tcp_md5sig_pool_lock);
+		cpu_relax();
+		goto retry;
+	} else
+		spin_unlock_bh(&tcp_md5sig_pool_lock);
+
+	if (alloc) {
+		/* we cannot hold spinlock here because this may sleep. */
+		struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
+		spin_lock_bh(&tcp_md5sig_pool_lock);
+		if (!p) {
+			tcp_md5sig_users--;
+			spin_unlock_bh(&tcp_md5sig_pool_lock);
+			return NULL;
+		}
+		pool = tcp_md5sig_pool;
+		if (pool) {
+			/* oops, it has already been assigned. */
+			spin_unlock_bh(&tcp_md5sig_pool_lock);
+			__tcp_free_md5sig_pool(p);
+		} else {
+			tcp_md5sig_pool = pool = p;
+			spin_unlock_bh(&tcp_md5sig_pool_lock);
+		}
+	}
+	return pool;
+}
+
+EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
+
+struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
+{
+	struct tcp_md5sig_pool **p;
+	spin_lock_bh(&tcp_md5sig_pool_lock);
+	p = tcp_md5sig_pool;
+	if (p)
+		tcp_md5sig_users++;
+	spin_unlock_bh(&tcp_md5sig_pool_lock);
+	return (p ? *per_cpu_ptr(p, cpu) : NULL);
+}
+
+EXPORT_SYMBOL(__tcp_get_md5sig_pool);
+
+void __tcp_put_md5sig_pool(void)
+{
+	tcp_free_md5sig_pool();
+}
+
+EXPORT_SYMBOL(__tcp_put_md5sig_pool);
+
+int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
+			struct tcphdr *th)
+{
+	struct scatterlist sg;
+	int err;
+
+	__sum16 old_checksum = th->check;
+	th->check = 0;
+	/* options aren't included in the hash */
+	sg_init_one(&sg, th, sizeof(struct tcphdr));
+	err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
+	th->check = old_checksum;
+	return err;
+}
+
+EXPORT_SYMBOL(tcp_md5_hash_header);
+
+int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
+			  struct sk_buff *skb, unsigned header_len)
+{
+	struct scatterlist sg;
+	const struct tcphdr *tp = tcp_hdr(skb);
+	struct hash_desc *desc = &hp->md5_desc;
+	unsigned i;
+	const unsigned head_data_len = skb_headlen(skb) > header_len ?
+				       skb_headlen(skb) - header_len : 0;
+	const struct skb_shared_info *shi = skb_shinfo(skb);
+
+	sg_init_table(&sg, 1);
+
+	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
+	if (crypto_hash_update(desc, &sg, head_data_len))
+		return 1;
+
+	for (i = 0; i < shi->nr_frags; ++i) {
+		const struct skb_frag_struct *f = &shi->frags[i];
+		sg_set_page(&sg, f->page, f->size, f->page_offset);
+		if (crypto_hash_update(desc, &sg, f->size))
+			return 1;
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL(tcp_md5_hash_skb_data);
+
+int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
+{
+	struct scatterlist sg;
+
+	sg_init_one(&sg, key->key, key->keylen);
+	return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
+}
+
+EXPORT_SYMBOL(tcp_md5_hash_key);
+
+#endif
+
+void tcp_done(struct sock *sk)
+{
+	if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
+		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
+
+	tcp_set_state(sk, TCP_CLOSE);
+	tcp_clear_xmit_timers(sk);
+
+	sk->sk_shutdown = SHUTDOWN_MASK;
+
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk->sk_state_change(sk);
+	else
+		inet_csk_destroy_sock(sk);
+}
+EXPORT_SYMBOL_GPL(tcp_done);
+
+extern struct tcp_congestion_ops tcp_reno;
+
+static __initdata unsigned long thash_entries;
+static int __init set_thash_entries(char *str)
+{
+	if (!str)
+		return 0;
+	thash_entries = simple_strtoul(str, &str, 0);
+	return 1;
+}
+__setup("thash_entries=", set_thash_entries);
+
+void __init tcp_init(void)
+{
+	struct sk_buff *skb = NULL;
+	unsigned long nr_pages, limit;
+	int order, i, max_share;
+
+	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
+
+	tcp_hashinfo.bind_bucket_cachep =
+		kmem_cache_create("tcp_bind_bucket",
+				  sizeof(struct inet_bind_bucket), 0,
+				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+
+	/* Size and allocate the main established and bind bucket
+	 * hash tables.
+	 *
+	 * The methodology is similar to that of the buffer cache.
+	 */
+	tcp_hashinfo.ehash =
+		alloc_large_system_hash("TCP established",
+					sizeof(struct inet_ehash_bucket),
+					thash_entries,
+					(num_physpages >= 128 * 1024) ?
+					13 : 15,
+					0,
+					&tcp_hashinfo.ehash_size,
+					NULL,
+					thash_entries ? 0 : 512 * 1024);
+	tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
+	for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
+		INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain);
+		INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain);
+	}
+	if (inet_ehash_locks_alloc(&tcp_hashinfo))
+		panic("TCP: failed to alloc ehash_locks");
+	tcp_hashinfo.bhash =
+		alloc_large_system_hash("TCP bind",
+					sizeof(struct inet_bind_hashbucket),
+					tcp_hashinfo.ehash_size,
+					(num_physpages >= 128 * 1024) ?
+					13 : 15,
+					0,
+					&tcp_hashinfo.bhash_size,
+					NULL,
+					64 * 1024);
+	tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
+	for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
+		spin_lock_init(&tcp_hashinfo.bhash[i].lock);
+		INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
+	}
+
+	/* Try to be a bit smarter and adjust defaults depending
+	 * on available memory.
+	 */
+	for (order = 0; ((1 << order) << PAGE_SHIFT) <
+			(tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
+			order++)
+		;
+	if (order >= 4) {
+		tcp_death_row.sysctl_max_tw_buckets = 180000;
+		sysctl_tcp_max_orphans = 4096 << (order - 4);
+		sysctl_max_syn_backlog = 1024;
+	} else if (order < 3) {
+		tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
+		sysctl_tcp_max_orphans >>= (3 - order);
+		sysctl_max_syn_backlog = 128;
+	}
+
+	/* Set the pressure threshold to be a fraction of global memory that
+	 * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
+	 * memory, with a floor of 128 pages.
+	 */
+	nr_pages = totalram_pages - totalhigh_pages;
+	limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+	limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
+	limit = max(limit, 128UL);
+	sysctl_tcp_mem[0] = limit / 4 * 3;
+	sysctl_tcp_mem[1] = limit;
+	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
+
+	/* Set per-socket limits to no more than 1/128 the pressure threshold */
+	limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
+	max_share = min(4UL*1024*1024, limit);
+
+	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
+	sysctl_tcp_wmem[1] = 16*1024;
+	sysctl_tcp_wmem[2] = max(64*1024, max_share);
+
+	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
+	sysctl_tcp_rmem[1] = 87380;
+	sysctl_tcp_rmem[2] = max(87380, max_share);
+
+	printk(KERN_INFO "TCP: Hash tables configured "
+	       "(established %d bind %d)\n",
+	       tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
+
+	tcp_register_congestion_control(&tcp_reno);
+}
+
+EXPORT_SYMBOL(tcp_close);
+EXPORT_SYMBOL(tcp_disconnect);
+EXPORT_SYMBOL(tcp_getsockopt);
+EXPORT_SYMBOL(tcp_ioctl);
+EXPORT_SYMBOL(tcp_poll);
+EXPORT_SYMBOL(tcp_read_sock);
+EXPORT_SYMBOL(tcp_recvmsg);
+EXPORT_SYMBOL(tcp_sendmsg);
+EXPORT_SYMBOL(tcp_splice_read);
+EXPORT_SYMBOL(tcp_sendpage);
+EXPORT_SYMBOL(tcp_setsockopt);
+EXPORT_SYMBOL(tcp_shutdown);
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
new file mode 100644
index 0000000..7eb7636
--- /dev/null
+++ b/net/ipv4/tcp_bic.c
@@ -0,0 +1,248 @@
+/*
+ * Binary Increase Congestion control for TCP
+ * Home page:
+ *      http://netsrv.csc.ncsu.edu/twiki/bin/view/Main/BIC
+ * This is from the implementation of BICTCP in
+ * Lison-Xu, Kahaled Harfoush, and Injong Rhee.
+ *  "Binary Increase Congestion Control for Fast, Long Distance
+ *  Networks" in InfoComm 2004
+ * Available from:
+ *  http://netsrv.csc.ncsu.edu/export/bitcp.pdf
+ *
+ * Unless BIC is enabled and congestion window is large
+ * this behaves the same as the original Reno.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <net/tcp.h>
+
+
+#define BICTCP_BETA_SCALE    1024	/* Scale factor beta calculation
+					 * max_cwnd = snd_cwnd * beta
+					 */
+#define BICTCP_B		4	 /*
+					  * In binary search,
+					  * go to point (max+min)/N
+					  */
+
+static int fast_convergence = 1;
+static int max_increment = 16;
+static int low_window = 14;
+static int beta = 819;		/* = 819/1024 (BICTCP_BETA_SCALE) */
+static int initial_ssthresh;
+static int smooth_part = 20;
+
+module_param(fast_convergence, int, 0644);
+MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence");
+module_param(max_increment, int, 0644);
+MODULE_PARM_DESC(max_increment, "Limit on increment allowed during binary search");
+module_param(low_window, int, 0644);
+MODULE_PARM_DESC(low_window, "lower bound on congestion window (for TCP friendliness)");
+module_param(beta, int, 0644);
+MODULE_PARM_DESC(beta, "beta for multiplicative increase");
+module_param(initial_ssthresh, int, 0644);
+MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold");
+module_param(smooth_part, int, 0644);
+MODULE_PARM_DESC(smooth_part, "log(B/(B*Smin))/log(B/(B-1))+B, # of RTT from Wmax-B to Wmax");
+
+
+/* BIC TCP Parameters */
+struct bictcp {
+	u32	cnt;		/* increase cwnd by 1 after ACKs */
+	u32 	last_max_cwnd;	/* last maximum snd_cwnd */
+	u32	loss_cwnd;	/* congestion window at last loss */
+	u32	last_cwnd;	/* the last snd_cwnd */
+	u32	last_time;	/* time when updated last_cwnd */
+	u32	epoch_start;	/* beginning of an epoch */
+#define ACK_RATIO_SHIFT	4
+	u32	delayed_ack;	/* estimate the ratio of Packets/ACKs << 4 */
+};
+
+static inline void bictcp_reset(struct bictcp *ca)
+{
+	ca->cnt = 0;
+	ca->last_max_cwnd = 0;
+	ca->loss_cwnd = 0;
+	ca->last_cwnd = 0;
+	ca->last_time = 0;
+	ca->epoch_start = 0;
+	ca->delayed_ack = 2 << ACK_RATIO_SHIFT;
+}
+
+static void bictcp_init(struct sock *sk)
+{
+	bictcp_reset(inet_csk_ca(sk));
+	if (initial_ssthresh)
+		tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
+}
+
+/*
+ * Compute congestion window to use.
+ */
+static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
+{
+	if (ca->last_cwnd == cwnd &&
+	    (s32)(tcp_time_stamp - ca->last_time) <= HZ / 32)
+		return;
+
+	ca->last_cwnd = cwnd;
+	ca->last_time = tcp_time_stamp;
+
+	if (ca->epoch_start == 0) /* record the beginning of an epoch */
+		ca->epoch_start = tcp_time_stamp;
+
+	/* start off normal */
+	if (cwnd <= low_window) {
+		ca->cnt = cwnd;
+		return;
+	}
+
+	/* binary increase */
+	if (cwnd < ca->last_max_cwnd) {
+		__u32 	dist = (ca->last_max_cwnd - cwnd)
+			/ BICTCP_B;
+
+		if (dist > max_increment)
+			/* linear increase */
+			ca->cnt = cwnd / max_increment;
+		else if (dist <= 1U)
+			/* binary search increase */
+			ca->cnt = (cwnd * smooth_part) / BICTCP_B;
+		else
+			/* binary search increase */
+			ca->cnt = cwnd / dist;
+	} else {
+		/* slow start AMD linear increase */
+		if (cwnd < ca->last_max_cwnd + BICTCP_B)
+			/* slow start */
+			ca->cnt = (cwnd * smooth_part) / BICTCP_B;
+		else if (cwnd < ca->last_max_cwnd + max_increment*(BICTCP_B-1))
+			/* slow start */
+			ca->cnt = (cwnd * (BICTCP_B-1))
+				/ (cwnd - ca->last_max_cwnd);
+		else
+			/* linear increase */
+			ca->cnt = cwnd / max_increment;
+	}
+
+	/* if in slow start or link utilization is very low */
+	if (ca->loss_cwnd == 0) {
+		if (ca->cnt > 20) /* increase cwnd 5% per RTT */
+			ca->cnt = 20;
+	}
+
+	ca->cnt = (ca->cnt << ACK_RATIO_SHIFT) / ca->delayed_ack;
+	if (ca->cnt == 0)			/* cannot be zero */
+		ca->cnt = 1;
+}
+
+static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+	else {
+		bictcp_update(ca, tp->snd_cwnd);
+
+		/* In dangerous area, increase slowly.
+		 * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
+		 */
+		if (tp->snd_cwnd_cnt >= ca->cnt) {
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+		} else
+			tp->snd_cwnd_cnt++;
+	}
+
+}
+
+/*
+ *	behave like Reno until low_window is reached,
+ *	then increase congestion window slowly
+ */
+static u32 bictcp_recalc_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	ca->epoch_start = 0;	/* end of epoch */
+
+	/* Wmax and fast convergence */
+	if (tp->snd_cwnd < ca->last_max_cwnd && fast_convergence)
+		ca->last_max_cwnd = (tp->snd_cwnd * (BICTCP_BETA_SCALE + beta))
+			/ (2 * BICTCP_BETA_SCALE);
+	else
+		ca->last_max_cwnd = tp->snd_cwnd;
+
+	ca->loss_cwnd = tp->snd_cwnd;
+
+
+	if (tp->snd_cwnd <= low_window)
+		return max(tp->snd_cwnd >> 1U, 2U);
+	else
+		return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U);
+}
+
+static u32 bictcp_undo_cwnd(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct bictcp *ca = inet_csk_ca(sk);
+	return max(tp->snd_cwnd, ca->last_max_cwnd);
+}
+
+static void bictcp_state(struct sock *sk, u8 new_state)
+{
+	if (new_state == TCP_CA_Loss)
+		bictcp_reset(inet_csk_ca(sk));
+}
+
+/* Track delayed acknowledgment ratio using sliding window
+ * ratio = (15*ratio + sample) / 16
+ */
+static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (icsk->icsk_ca_state == TCP_CA_Open) {
+		struct bictcp *ca = inet_csk_ca(sk);
+		cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
+		ca->delayed_ack += cnt;
+	}
+}
+
+
+static struct tcp_congestion_ops bictcp = {
+	.init		= bictcp_init,
+	.ssthresh	= bictcp_recalc_ssthresh,
+	.cong_avoid	= bictcp_cong_avoid,
+	.set_state	= bictcp_state,
+	.undo_cwnd	= bictcp_undo_cwnd,
+	.pkts_acked     = bictcp_acked,
+	.owner		= THIS_MODULE,
+	.name		= "bic",
+};
+
+static int __init bictcp_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE);
+	return tcp_register_congestion_control(&bictcp);
+}
+
+static void __exit bictcp_unregister(void)
+{
+	tcp_unregister_congestion_control(&bictcp);
+}
+
+module_init(bictcp_register);
+module_exit(bictcp_unregister);
+
+MODULE_AUTHOR("Stephen Hemminger");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("BIC TCP");
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
new file mode 100644
index 0000000..4ec5b4e
--- /dev/null
+++ b/net/ipv4/tcp_cong.c
@@ -0,0 +1,415 @@
+/*
+ * Plugable TCP congestion control support and newReno
+ * congestion control.
+ * Based on ideas from I/O scheduler suport and Web100.
+ *
+ * Copyright (C) 2005 Stephen Hemminger <shemminger@osdl.org>
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <net/tcp.h>
+
+int sysctl_tcp_max_ssthresh = 0;
+
+static DEFINE_SPINLOCK(tcp_cong_list_lock);
+static LIST_HEAD(tcp_cong_list);
+
+/* Simple linear search, don't expect many entries! */
+static struct tcp_congestion_ops *tcp_ca_find(const char *name)
+{
+	struct tcp_congestion_ops *e;
+
+	list_for_each_entry_rcu(e, &tcp_cong_list, list) {
+		if (strcmp(e->name, name) == 0)
+			return e;
+	}
+
+	return NULL;
+}
+
+/*
+ * Attach new congestion control algorithm to the list
+ * of available options.
+ */
+int tcp_register_congestion_control(struct tcp_congestion_ops *ca)
+{
+	int ret = 0;
+
+	/* all algorithms must implement ssthresh and cong_avoid ops */
+	if (!ca->ssthresh || !ca->cong_avoid) {
+		printk(KERN_ERR "TCP %s does not implement required ops\n",
+		       ca->name);
+		return -EINVAL;
+	}
+
+	spin_lock(&tcp_cong_list_lock);
+	if (tcp_ca_find(ca->name)) {
+		printk(KERN_NOTICE "TCP %s already registered\n", ca->name);
+		ret = -EEXIST;
+	} else {
+		list_add_tail_rcu(&ca->list, &tcp_cong_list);
+		printk(KERN_INFO "TCP %s registered\n", ca->name);
+	}
+	spin_unlock(&tcp_cong_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(tcp_register_congestion_control);
+
+/*
+ * Remove congestion control algorithm, called from
+ * the module's remove function.  Module ref counts are used
+ * to ensure that this can't be done till all sockets using
+ * that method are closed.
+ */
+void tcp_unregister_congestion_control(struct tcp_congestion_ops *ca)
+{
+	spin_lock(&tcp_cong_list_lock);
+	list_del_rcu(&ca->list);
+	spin_unlock(&tcp_cong_list_lock);
+}
+EXPORT_SYMBOL_GPL(tcp_unregister_congestion_control);
+
+/* Assign choice of congestion control. */
+void tcp_init_congestion_control(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_congestion_ops *ca;
+
+	/* if no choice made yet assign the current value set as default */
+	if (icsk->icsk_ca_ops == &tcp_init_congestion_ops) {
+		rcu_read_lock();
+		list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+			if (try_module_get(ca->owner)) {
+				icsk->icsk_ca_ops = ca;
+				break;
+			}
+
+			/* fallback to next available */
+		}
+		rcu_read_unlock();
+	}
+
+	if (icsk->icsk_ca_ops->init)
+		icsk->icsk_ca_ops->init(sk);
+}
+
+/* Manage refcounts on socket close. */
+void tcp_cleanup_congestion_control(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (icsk->icsk_ca_ops->release)
+		icsk->icsk_ca_ops->release(sk);
+	module_put(icsk->icsk_ca_ops->owner);
+}
+
+/* Used by sysctl to change default congestion control */
+int tcp_set_default_congestion_control(const char *name)
+{
+	struct tcp_congestion_ops *ca;
+	int ret = -ENOENT;
+
+	spin_lock(&tcp_cong_list_lock);
+	ca = tcp_ca_find(name);
+#ifdef CONFIG_MODULES
+	if (!ca && capable(CAP_SYS_MODULE)) {
+		spin_unlock(&tcp_cong_list_lock);
+
+		request_module("tcp_%s", name);
+		spin_lock(&tcp_cong_list_lock);
+		ca = tcp_ca_find(name);
+	}
+#endif
+
+	if (ca) {
+		ca->flags |= TCP_CONG_NON_RESTRICTED;	/* default is always allowed */
+		list_move(&ca->list, &tcp_cong_list);
+		ret = 0;
+	}
+	spin_unlock(&tcp_cong_list_lock);
+
+	return ret;
+}
+
+/* Set default value from kernel configuration at bootup */
+static int __init tcp_congestion_default(void)
+{
+	return tcp_set_default_congestion_control(CONFIG_DEFAULT_TCP_CONG);
+}
+late_initcall(tcp_congestion_default);
+
+
+/* Build string with list of available congestion control values */
+void tcp_get_available_congestion_control(char *buf, size_t maxlen)
+{
+	struct tcp_congestion_ops *ca;
+	size_t offs = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+		offs += snprintf(buf + offs, maxlen - offs,
+				 "%s%s",
+				 offs == 0 ? "" : " ", ca->name);
+
+	}
+	rcu_read_unlock();
+}
+
+/* Get current default congestion control */
+void tcp_get_default_congestion_control(char *name)
+{
+	struct tcp_congestion_ops *ca;
+	/* We will always have reno... */
+	BUG_ON(list_empty(&tcp_cong_list));
+
+	rcu_read_lock();
+	ca = list_entry(tcp_cong_list.next, struct tcp_congestion_ops, list);
+	strncpy(name, ca->name, TCP_CA_NAME_MAX);
+	rcu_read_unlock();
+}
+
+/* Built list of non-restricted congestion control values */
+void tcp_get_allowed_congestion_control(char *buf, size_t maxlen)
+{
+	struct tcp_congestion_ops *ca;
+	size_t offs = 0;
+
+	*buf = '\0';
+	rcu_read_lock();
+	list_for_each_entry_rcu(ca, &tcp_cong_list, list) {
+		if (!(ca->flags & TCP_CONG_NON_RESTRICTED))
+			continue;
+		offs += snprintf(buf + offs, maxlen - offs,
+				 "%s%s",
+				 offs == 0 ? "" : " ", ca->name);
+
+	}
+	rcu_read_unlock();
+}
+
+/* Change list of non-restricted congestion control */
+int tcp_set_allowed_congestion_control(char *val)
+{
+	struct tcp_congestion_ops *ca;
+	char *clone, *name;
+	int ret = 0;
+
+	clone = kstrdup(val, GFP_USER);
+	if (!clone)
+		return -ENOMEM;
+
+	spin_lock(&tcp_cong_list_lock);
+	/* pass 1 check for bad entries */
+	while ((name = strsep(&clone, " ")) && *name) {
+		ca = tcp_ca_find(name);
+		if (!ca) {
+			ret = -ENOENT;
+			goto out;
+		}
+	}
+
+	/* pass 2 clear old values */
+	list_for_each_entry_rcu(ca, &tcp_cong_list, list)
+		ca->flags &= ~TCP_CONG_NON_RESTRICTED;
+
+	/* pass 3 mark as allowed */
+	while ((name = strsep(&val, " ")) && *name) {
+		ca = tcp_ca_find(name);
+		WARN_ON(!ca);
+		if (ca)
+			ca->flags |= TCP_CONG_NON_RESTRICTED;
+	}
+out:
+	spin_unlock(&tcp_cong_list_lock);
+
+	return ret;
+}
+
+
+/* Change congestion control for socket */
+int tcp_set_congestion_control(struct sock *sk, const char *name)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_congestion_ops *ca;
+	int err = 0;
+
+	rcu_read_lock();
+	ca = tcp_ca_find(name);
+
+	/* no change asking for existing value */
+	if (ca == icsk->icsk_ca_ops)
+		goto out;
+
+#ifdef CONFIG_MODULES
+	/* not found attempt to autoload module */
+	if (!ca && capable(CAP_SYS_MODULE)) {
+		rcu_read_unlock();
+		request_module("tcp_%s", name);
+		rcu_read_lock();
+		ca = tcp_ca_find(name);
+	}
+#endif
+	if (!ca)
+		err = -ENOENT;
+
+	else if (!((ca->flags & TCP_CONG_NON_RESTRICTED) || capable(CAP_NET_ADMIN)))
+		err = -EPERM;
+
+	else if (!try_module_get(ca->owner))
+		err = -EBUSY;
+
+	else {
+		tcp_cleanup_congestion_control(sk);
+		icsk->icsk_ca_ops = ca;
+
+		if (sk->sk_state != TCP_CLOSE && icsk->icsk_ca_ops->init)
+			icsk->icsk_ca_ops->init(sk);
+	}
+ out:
+	rcu_read_unlock();
+	return err;
+}
+
+/* RFC2861 Check whether we are limited by application or congestion window
+ * This is the inverse of cwnd check in tcp_tso_should_defer
+ */
+int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	u32 left;
+
+	if (in_flight >= tp->snd_cwnd)
+		return 1;
+
+	left = tp->snd_cwnd - in_flight;
+	if (sk_can_gso(sk) &&
+	    left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd &&
+	    left * tp->mss_cache < sk->sk_gso_max_size)
+		return 1;
+	return left <= tcp_max_burst(tp);
+}
+EXPORT_SYMBOL_GPL(tcp_is_cwnd_limited);
+
+/*
+ * Slow start is used when congestion window is less than slow start
+ * threshold. This version implements the basic RFC2581 version
+ * and optionally supports:
+ * 	RFC3742 Limited Slow Start  	  - growth limited to max_ssthresh
+ *	RFC3465 Appropriate Byte Counting - growth limited by bytes acknowledged
+ */
+void tcp_slow_start(struct tcp_sock *tp)
+{
+	int cnt; /* increase in packets */
+
+	/* RFC3465: ABC Slow start
+	 * Increase only after a full MSS of bytes is acked
+	 *
+	 * TCP sender SHOULD increase cwnd by the number of
+	 * previously unacknowledged bytes ACKed by each incoming
+	 * acknowledgment, provided the increase is not more than L
+	 */
+	if (sysctl_tcp_abc && tp->bytes_acked < tp->mss_cache)
+		return;
+
+	if (sysctl_tcp_max_ssthresh > 0 && tp->snd_cwnd > sysctl_tcp_max_ssthresh)
+		cnt = sysctl_tcp_max_ssthresh >> 1;	/* limited slow start */
+	else
+		cnt = tp->snd_cwnd;			/* exponential increase */
+
+	/* RFC3465: ABC
+	 * We MAY increase by 2 if discovered delayed ack
+	 */
+	if (sysctl_tcp_abc > 1 && tp->bytes_acked >= 2*tp->mss_cache)
+		cnt <<= 1;
+	tp->bytes_acked = 0;
+
+	tp->snd_cwnd_cnt += cnt;
+	while (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+		tp->snd_cwnd_cnt -= tp->snd_cwnd;
+		if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+			tp->snd_cwnd++;
+	}
+}
+EXPORT_SYMBOL_GPL(tcp_slow_start);
+
+/*
+ * TCP Reno congestion control
+ * This is special case used for fallback as well.
+ */
+/* This is Jacobson's slow start and congestion avoidance.
+ * SIGCOMM '88, p. 328.
+ */
+void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	/* In "safe" area, increase. */
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+
+	/* In dangerous area, increase slowly. */
+	else if (sysctl_tcp_abc) {
+		/* RFC3465: Appropriate Byte Count
+		 * increase once for each full cwnd acked
+		 */
+		if (tp->bytes_acked >= tp->snd_cwnd*tp->mss_cache) {
+			tp->bytes_acked -= tp->snd_cwnd*tp->mss_cache;
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+		}
+	} else {
+		/* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd */
+		if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+		} else
+			tp->snd_cwnd_cnt++;
+	}
+}
+EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
+
+/* Slow start threshold is half the congestion window (min 2) */
+u32 tcp_reno_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	return max(tp->snd_cwnd >> 1U, 2U);
+}
+EXPORT_SYMBOL_GPL(tcp_reno_ssthresh);
+
+/* Lower bound on congestion window with halving. */
+u32 tcp_reno_min_cwnd(const struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	return tp->snd_ssthresh/2;
+}
+EXPORT_SYMBOL_GPL(tcp_reno_min_cwnd);
+
+struct tcp_congestion_ops tcp_reno = {
+	.flags		= TCP_CONG_NON_RESTRICTED,
+	.name		= "reno",
+	.owner		= THIS_MODULE,
+	.ssthresh	= tcp_reno_ssthresh,
+	.cong_avoid	= tcp_reno_cong_avoid,
+	.min_cwnd	= tcp_reno_min_cwnd,
+};
+
+/* Initial congestion control used (until SYN)
+ * really reno under another name so we can tell difference
+ * during tcp_set_default_congestion_control
+ */
+struct tcp_congestion_ops tcp_init_congestion_ops  = {
+	.name		= "",
+	.owner		= THIS_MODULE,
+	.ssthresh	= tcp_reno_ssthresh,
+	.cong_avoid	= tcp_reno_cong_avoid,
+	.min_cwnd	= tcp_reno_min_cwnd,
+};
+EXPORT_SYMBOL_GPL(tcp_init_congestion_ops);
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
new file mode 100644
index 0000000..4a1221e
--- /dev/null
+++ b/net/ipv4/tcp_cubic.c
@@ -0,0 +1,375 @@
+/*
+ * TCP CUBIC: Binary Increase Congestion control for TCP v2.2
+ * Home page:
+ *      http://netsrv.csc.ncsu.edu/twiki/bin/view/Main/BIC
+ * This is from the implementation of CUBIC TCP in
+ * Injong Rhee, Lisong Xu.
+ *  "CUBIC: A New TCP-Friendly High-Speed TCP Variant
+ *  in PFLDnet 2005
+ * Available from:
+ *  http://netsrv.csc.ncsu.edu/export/cubic-paper.pdf
+ *
+ * Unless CUBIC is enabled and congestion window is large
+ * this behaves the same as the original Reno.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/math64.h>
+#include <net/tcp.h>
+
+#define BICTCP_BETA_SCALE    1024	/* Scale factor beta calculation
+					 * max_cwnd = snd_cwnd * beta
+					 */
+#define	BICTCP_HZ		10	/* BIC HZ 2^10 = 1024 */
+
+static int fast_convergence __read_mostly = 1;
+static int beta __read_mostly = 717;	/* = 717/1024 (BICTCP_BETA_SCALE) */
+static int initial_ssthresh __read_mostly;
+static int bic_scale __read_mostly = 41;
+static int tcp_friendliness __read_mostly = 1;
+
+static u32 cube_rtt_scale __read_mostly;
+static u32 beta_scale __read_mostly;
+static u64 cube_factor __read_mostly;
+
+/* Note parameters that are used for precomputing scale factors are read-only */
+module_param(fast_convergence, int, 0644);
+MODULE_PARM_DESC(fast_convergence, "turn on/off fast convergence");
+module_param(beta, int, 0644);
+MODULE_PARM_DESC(beta, "beta for multiplicative increase");
+module_param(initial_ssthresh, int, 0644);
+MODULE_PARM_DESC(initial_ssthresh, "initial value of slow start threshold");
+module_param(bic_scale, int, 0444);
+MODULE_PARM_DESC(bic_scale, "scale (scaled by 1024) value for bic function (bic_scale/1024)");
+module_param(tcp_friendliness, int, 0644);
+MODULE_PARM_DESC(tcp_friendliness, "turn on/off tcp friendliness");
+
+/* BIC TCP Parameters */
+struct bictcp {
+	u32	cnt;		/* increase cwnd by 1 after ACKs */
+	u32 	last_max_cwnd;	/* last maximum snd_cwnd */
+	u32	loss_cwnd;	/* congestion window at last loss */
+	u32	last_cwnd;	/* the last snd_cwnd */
+	u32	last_time;	/* time when updated last_cwnd */
+	u32	bic_origin_point;/* origin point of bic function */
+	u32	bic_K;		/* time to origin point from the beginning of the current epoch */
+	u32	delay_min;	/* min delay */
+	u32	epoch_start;	/* beginning of an epoch */
+	u32	ack_cnt;	/* number of acks */
+	u32	tcp_cwnd;	/* estimated tcp cwnd */
+#define ACK_RATIO_SHIFT	4
+	u32	delayed_ack;	/* estimate the ratio of Packets/ACKs << 4 */
+};
+
+static inline void bictcp_reset(struct bictcp *ca)
+{
+	ca->cnt = 0;
+	ca->last_max_cwnd = 0;
+	ca->loss_cwnd = 0;
+	ca->last_cwnd = 0;
+	ca->last_time = 0;
+	ca->bic_origin_point = 0;
+	ca->bic_K = 0;
+	ca->delay_min = 0;
+	ca->epoch_start = 0;
+	ca->delayed_ack = 2 << ACK_RATIO_SHIFT;
+	ca->ack_cnt = 0;
+	ca->tcp_cwnd = 0;
+}
+
+static void bictcp_init(struct sock *sk)
+{
+	bictcp_reset(inet_csk_ca(sk));
+	if (initial_ssthresh)
+		tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
+}
+
+/* calculate the cubic root of x using a table lookup followed by one
+ * Newton-Raphson iteration.
+ * Avg err ~= 0.195%
+ */
+static u32 cubic_root(u64 a)
+{
+	u32 x, b, shift;
+	/*
+	 * cbrt(x) MSB values for x MSB values in [0..63].
+	 * Precomputed then refined by hand - Willy Tarreau
+	 *
+	 * For x in [0..63],
+	 *   v = cbrt(x << 18) - 1
+	 *   cbrt(x) = (v[x] + 10) >> 6
+	 */
+	static const u8 v[] = {
+		/* 0x00 */    0,   54,   54,   54,  118,  118,  118,  118,
+		/* 0x08 */  123,  129,  134,  138,  143,  147,  151,  156,
+		/* 0x10 */  157,  161,  164,  168,  170,  173,  176,  179,
+		/* 0x18 */  181,  185,  187,  190,  192,  194,  197,  199,
+		/* 0x20 */  200,  202,  204,  206,  209,  211,  213,  215,
+		/* 0x28 */  217,  219,  221,  222,  224,  225,  227,  229,
+		/* 0x30 */  231,  232,  234,  236,  237,  239,  240,  242,
+		/* 0x38 */  244,  245,  246,  248,  250,  251,  252,  254,
+	};
+
+	b = fls64(a);
+	if (b < 7) {
+		/* a in [0..63] */
+		return ((u32)v[(u32)a] + 35) >> 6;
+	}
+
+	b = ((b * 84) >> 8) - 1;
+	shift = (a >> (b * 3));
+
+	x = ((u32)(((u32)v[shift] + 10) << b)) >> 6;
+
+	/*
+	 * Newton-Raphson iteration
+	 *                         2
+	 * x    = ( 2 * x  +  a / x  ) / 3
+	 *  k+1          k         k
+	 */
+	x = (2 * x + (u32)div64_u64(a, (u64)x * (u64)(x - 1)));
+	x = ((x * 341) >> 10);
+	return x;
+}
+
+/*
+ * Compute congestion window to use.
+ */
+static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
+{
+	u64 offs;
+	u32 delta, t, bic_target, max_cnt;
+
+	ca->ack_cnt++;	/* count the number of ACKs */
+
+	if (ca->last_cwnd == cwnd &&
+	    (s32)(tcp_time_stamp - ca->last_time) <= HZ / 32)
+		return;
+
+	ca->last_cwnd = cwnd;
+	ca->last_time = tcp_time_stamp;
+
+	if (ca->epoch_start == 0) {
+		ca->epoch_start = tcp_time_stamp;	/* record the beginning of an epoch */
+		ca->ack_cnt = 1;			/* start counting */
+		ca->tcp_cwnd = cwnd;			/* syn with cubic */
+
+		if (ca->last_max_cwnd <= cwnd) {
+			ca->bic_K = 0;
+			ca->bic_origin_point = cwnd;
+		} else {
+			/* Compute new K based on
+			 * (wmax-cwnd) * (srtt>>3 / HZ) / c * 2^(3*bictcp_HZ)
+			 */
+			ca->bic_K = cubic_root(cube_factor
+					       * (ca->last_max_cwnd - cwnd));
+			ca->bic_origin_point = ca->last_max_cwnd;
+		}
+	}
+
+	/* cubic function - calc*/
+	/* calculate c * time^3 / rtt,
+	 *  while considering overflow in calculation of time^3
+	 * (so time^3 is done by using 64 bit)
+	 * and without the support of division of 64bit numbers
+	 * (so all divisions are done by using 32 bit)
+	 *  also NOTE the unit of those veriables
+	 *	  time  = (t - K) / 2^bictcp_HZ
+	 *	  c = bic_scale >> 10
+	 * rtt  = (srtt >> 3) / HZ
+	 * !!! The following code does not have overflow problems,
+	 * if the cwnd < 1 million packets !!!
+	 */
+
+	/* change the unit from HZ to bictcp_HZ */
+	t = ((tcp_time_stamp + (ca->delay_min>>3) - ca->epoch_start)
+	     << BICTCP_HZ) / HZ;
+
+	if (t < ca->bic_K)		/* t - K */
+		offs = ca->bic_K - t;
+	else
+		offs = t - ca->bic_K;
+
+	/* c/rtt * (t-K)^3 */
+	delta = (cube_rtt_scale * offs * offs * offs) >> (10+3*BICTCP_HZ);
+	if (t < ca->bic_K)                                	/* below origin*/
+		bic_target = ca->bic_origin_point - delta;
+	else                                                	/* above origin*/
+		bic_target = ca->bic_origin_point + delta;
+
+	/* cubic function - calc bictcp_cnt*/
+	if (bic_target > cwnd) {
+		ca->cnt = cwnd / (bic_target - cwnd);
+	} else {
+		ca->cnt = 100 * cwnd;              /* very small increment*/
+	}
+
+	/* TCP Friendly */
+	if (tcp_friendliness) {
+		u32 scale = beta_scale;
+		delta = (cwnd * scale) >> 3;
+		while (ca->ack_cnt > delta) {		/* update tcp cwnd */
+			ca->ack_cnt -= delta;
+			ca->tcp_cwnd++;
+		}
+
+		if (ca->tcp_cwnd > cwnd){	/* if bic is slower than tcp */
+			delta = ca->tcp_cwnd - cwnd;
+			max_cnt = cwnd / delta;
+			if (ca->cnt > max_cnt)
+				ca->cnt = max_cnt;
+		}
+	}
+
+	ca->cnt = (ca->cnt << ACK_RATIO_SHIFT) / ca->delayed_ack;
+	if (ca->cnt == 0)			/* cannot be zero */
+		ca->cnt = 1;
+}
+
+static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+	else {
+		bictcp_update(ca, tp->snd_cwnd);
+
+		/* In dangerous area, increase slowly.
+		 * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd
+		 */
+		if (tp->snd_cwnd_cnt >= ca->cnt) {
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+		} else
+			tp->snd_cwnd_cnt++;
+	}
+
+}
+
+static u32 bictcp_recalc_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	ca->epoch_start = 0;	/* end of epoch */
+
+	/* Wmax and fast convergence */
+	if (tp->snd_cwnd < ca->last_max_cwnd && fast_convergence)
+		ca->last_max_cwnd = (tp->snd_cwnd * (BICTCP_BETA_SCALE + beta))
+			/ (2 * BICTCP_BETA_SCALE);
+	else
+		ca->last_max_cwnd = tp->snd_cwnd;
+
+	ca->loss_cwnd = tp->snd_cwnd;
+
+	return max((tp->snd_cwnd * beta) / BICTCP_BETA_SCALE, 2U);
+}
+
+static u32 bictcp_undo_cwnd(struct sock *sk)
+{
+	struct bictcp *ca = inet_csk_ca(sk);
+
+	return max(tcp_sk(sk)->snd_cwnd, ca->last_max_cwnd);
+}
+
+static void bictcp_state(struct sock *sk, u8 new_state)
+{
+	if (new_state == TCP_CA_Loss)
+		bictcp_reset(inet_csk_ca(sk));
+}
+
+/* Track delayed acknowledgment ratio using sliding window
+ * ratio = (15*ratio + sample) / 16
+ */
+static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct bictcp *ca = inet_csk_ca(sk);
+	u32 delay;
+
+	if (icsk->icsk_ca_state == TCP_CA_Open) {
+		cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
+		ca->delayed_ack += cnt;
+	}
+
+	/* Some calls are for duplicates without timetamps */
+	if (rtt_us < 0)
+		return;
+
+	/* Discard delay samples right after fast recovery */
+	if ((s32)(tcp_time_stamp - ca->epoch_start) < HZ)
+		return;
+
+	delay = usecs_to_jiffies(rtt_us) << 3;
+	if (delay == 0)
+		delay = 1;
+
+	/* first time call or link delay decreases */
+	if (ca->delay_min == 0 || ca->delay_min > delay)
+		ca->delay_min = delay;
+}
+
+static struct tcp_congestion_ops cubictcp = {
+	.init		= bictcp_init,
+	.ssthresh	= bictcp_recalc_ssthresh,
+	.cong_avoid	= bictcp_cong_avoid,
+	.set_state	= bictcp_state,
+	.undo_cwnd	= bictcp_undo_cwnd,
+	.pkts_acked     = bictcp_acked,
+	.owner		= THIS_MODULE,
+	.name		= "cubic",
+};
+
+static int __init cubictcp_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct bictcp) > ICSK_CA_PRIV_SIZE);
+
+	/* Precompute a bunch of the scaling factors that are used per-packet
+	 * based on SRTT of 100ms
+	 */
+
+	beta_scale = 8*(BICTCP_BETA_SCALE+beta)/ 3 / (BICTCP_BETA_SCALE - beta);
+
+	cube_rtt_scale = (bic_scale * 10);	/* 1024*c/rtt */
+
+	/* calculate the "K" for (wmax-cwnd) = c/rtt * K^3
+	 *  so K = cubic_root( (wmax-cwnd)*rtt/c )
+	 * the unit of K is bictcp_HZ=2^10, not HZ
+	 *
+	 *  c = bic_scale >> 10
+	 *  rtt = 100ms
+	 *
+	 * the following code has been designed and tested for
+	 * cwnd < 1 million packets
+	 * RTT < 100 seconds
+	 * HZ < 1,000,00  (corresponding to 10 nano-second)
+	 */
+
+	/* 1/c * 2^2*bictcp_HZ * srtt */
+	cube_factor = 1ull << (10+3*BICTCP_HZ); /* 2^40 */
+
+	/* divide by bic_scale and by constant Srtt (100ms) */
+	do_div(cube_factor, bic_scale * 10);
+
+	return tcp_register_congestion_control(&cubictcp);
+}
+
+static void __exit cubictcp_unregister(void)
+{
+	tcp_unregister_congestion_control(&cubictcp);
+}
+
+module_init(cubictcp_register);
+module_exit(cubictcp_unregister);
+
+MODULE_AUTHOR("Sangtae Ha, Stephen Hemminger");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CUBIC TCP");
+MODULE_VERSION("2.2");
diff --git a/net/ipv4/tcp_diag.c b/net/ipv4/tcp_diag.c
new file mode 100644
index 0000000..838d491
--- /dev/null
+++ b/net/ipv4/tcp_diag.c
@@ -0,0 +1,57 @@
+/*
+ * tcp_diag.c	Module for monitoring TCP transport protocols sockets.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+
+#include <linux/module.h>
+#include <linux/inet_diag.h>
+
+#include <linux/tcp.h>
+
+#include <net/tcp.h>
+
+static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
+			      void *_info)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_info *info = _info;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		r->idiag_rqueue = sk->sk_ack_backlog;
+		r->idiag_wqueue = sk->sk_max_ack_backlog;
+	} else {
+		r->idiag_rqueue = tp->rcv_nxt - tp->copied_seq;
+		r->idiag_wqueue = tp->write_seq - tp->snd_una;
+	}
+	if (info != NULL)
+		tcp_get_info(sk, info);
+}
+
+static struct inet_diag_handler tcp_diag_handler = {
+	.idiag_hashinfo	 = &tcp_hashinfo,
+	.idiag_get_info	 = tcp_diag_get_info,
+	.idiag_type	 = TCPDIAG_GETSOCK,
+	.idiag_info_size = sizeof(struct tcp_info),
+};
+
+static int __init tcp_diag_init(void)
+{
+	return inet_diag_register(&tcp_diag_handler);
+}
+
+static void __exit tcp_diag_exit(void)
+{
+	inet_diag_unregister(&tcp_diag_handler);
+}
+
+module_init(tcp_diag_init);
+module_exit(tcp_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_INET_DIAG, TCPDIAG_GETSOCK);
diff --git a/net/ipv4/tcp_highspeed.c b/net/ipv4/tcp_highspeed.c
new file mode 100644
index 0000000..8b6caaf
--- /dev/null
+++ b/net/ipv4/tcp_highspeed.c
@@ -0,0 +1,187 @@
+/*
+ * Sally Floyd's High Speed TCP (RFC 3649) congestion control
+ *
+ * See http://www.icir.org/floyd/hstcp.html
+ *
+ * John Heffner <jheffner@psc.edu>
+ */
+
+#include <linux/module.h>
+#include <net/tcp.h>
+
+
+/* From AIMD tables from RFC 3649 appendix B,
+ * with fixed-point MD scaled <<8.
+ */
+static const struct hstcp_aimd_val {
+	unsigned int cwnd;
+	unsigned int md;
+} hstcp_aimd_vals[] = {
+ {     38,  128, /*  0.50 */ },
+ {    118,  112, /*  0.44 */ },
+ {    221,  104, /*  0.41 */ },
+ {    347,   98, /*  0.38 */ },
+ {    495,   93, /*  0.37 */ },
+ {    663,   89, /*  0.35 */ },
+ {    851,   86, /*  0.34 */ },
+ {   1058,   83, /*  0.33 */ },
+ {   1284,   81, /*  0.32 */ },
+ {   1529,   78, /*  0.31 */ },
+ {   1793,   76, /*  0.30 */ },
+ {   2076,   74, /*  0.29 */ },
+ {   2378,   72, /*  0.28 */ },
+ {   2699,   71, /*  0.28 */ },
+ {   3039,   69, /*  0.27 */ },
+ {   3399,   68, /*  0.27 */ },
+ {   3778,   66, /*  0.26 */ },
+ {   4177,   65, /*  0.26 */ },
+ {   4596,   64, /*  0.25 */ },
+ {   5036,   62, /*  0.25 */ },
+ {   5497,   61, /*  0.24 */ },
+ {   5979,   60, /*  0.24 */ },
+ {   6483,   59, /*  0.23 */ },
+ {   7009,   58, /*  0.23 */ },
+ {   7558,   57, /*  0.22 */ },
+ {   8130,   56, /*  0.22 */ },
+ {   8726,   55, /*  0.22 */ },
+ {   9346,   54, /*  0.21 */ },
+ {   9991,   53, /*  0.21 */ },
+ {  10661,   52, /*  0.21 */ },
+ {  11358,   52, /*  0.20 */ },
+ {  12082,   51, /*  0.20 */ },
+ {  12834,   50, /*  0.20 */ },
+ {  13614,   49, /*  0.19 */ },
+ {  14424,   48, /*  0.19 */ },
+ {  15265,   48, /*  0.19 */ },
+ {  16137,   47, /*  0.19 */ },
+ {  17042,   46, /*  0.18 */ },
+ {  17981,   45, /*  0.18 */ },
+ {  18955,   45, /*  0.18 */ },
+ {  19965,   44, /*  0.17 */ },
+ {  21013,   43, /*  0.17 */ },
+ {  22101,   43, /*  0.17 */ },
+ {  23230,   42, /*  0.17 */ },
+ {  24402,   41, /*  0.16 */ },
+ {  25618,   41, /*  0.16 */ },
+ {  26881,   40, /*  0.16 */ },
+ {  28193,   39, /*  0.16 */ },
+ {  29557,   39, /*  0.15 */ },
+ {  30975,   38, /*  0.15 */ },
+ {  32450,   38, /*  0.15 */ },
+ {  33986,   37, /*  0.15 */ },
+ {  35586,   36, /*  0.14 */ },
+ {  37253,   36, /*  0.14 */ },
+ {  38992,   35, /*  0.14 */ },
+ {  40808,   35, /*  0.14 */ },
+ {  42707,   34, /*  0.13 */ },
+ {  44694,   33, /*  0.13 */ },
+ {  46776,   33, /*  0.13 */ },
+ {  48961,   32, /*  0.13 */ },
+ {  51258,   32, /*  0.13 */ },
+ {  53677,   31, /*  0.12 */ },
+ {  56230,   30, /*  0.12 */ },
+ {  58932,   30, /*  0.12 */ },
+ {  61799,   29, /*  0.12 */ },
+ {  64851,   28, /*  0.11 */ },
+ {  68113,   28, /*  0.11 */ },
+ {  71617,   27, /*  0.11 */ },
+ {  75401,   26, /*  0.10 */ },
+ {  79517,   26, /*  0.10 */ },
+ {  84035,   25, /*  0.10 */ },
+ {  89053,   24, /*  0.10 */ },
+};
+
+#define HSTCP_AIMD_MAX	ARRAY_SIZE(hstcp_aimd_vals)
+
+struct hstcp {
+	u32	ai;
+};
+
+static void hstcp_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct hstcp *ca = inet_csk_ca(sk);
+
+	ca->ai = 0;
+
+	/* Ensure the MD arithmetic works.  This is somewhat pedantic,
+	 * since I don't think we will see a cwnd this large. :) */
+	tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
+}
+
+static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct hstcp *ca = inet_csk_ca(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+	else {
+		/* Update AIMD parameters.
+		 *
+		 * We want to guarantee that:
+		 *     hstcp_aimd_vals[ca->ai-1].cwnd <
+		 *     snd_cwnd <=
+		 *     hstcp_aimd_vals[ca->ai].cwnd
+		 */
+		if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
+			while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
+			       ca->ai < HSTCP_AIMD_MAX - 1)
+				ca->ai++;
+		} else if (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd) {
+			while (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd)
+				ca->ai--;
+		}
+
+		/* Do additive increase */
+		if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
+			/* cwnd = cwnd + a(w) / cwnd */
+			tp->snd_cwnd_cnt += ca->ai + 1;
+			if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+				tp->snd_cwnd_cnt -= tp->snd_cwnd;
+				tp->snd_cwnd++;
+			}
+		}
+	}
+}
+
+static u32 hstcp_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct hstcp *ca = inet_csk_ca(sk);
+
+	/* Do multiplicative decrease */
+	return max(tp->snd_cwnd - ((tp->snd_cwnd * hstcp_aimd_vals[ca->ai].md) >> 8), 2U);
+}
+
+
+static struct tcp_congestion_ops tcp_highspeed = {
+	.init		= hstcp_init,
+	.ssthresh	= hstcp_ssthresh,
+	.cong_avoid	= hstcp_cong_avoid,
+	.min_cwnd	= tcp_reno_min_cwnd,
+
+	.owner		= THIS_MODULE,
+	.name		= "highspeed"
+};
+
+static int __init hstcp_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
+	return tcp_register_congestion_control(&tcp_highspeed);
+}
+
+static void __exit hstcp_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_highspeed);
+}
+
+module_init(hstcp_register);
+module_exit(hstcp_unregister);
+
+MODULE_AUTHOR("John Heffner");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("High Speed TCP");
diff --git a/net/ipv4/tcp_htcp.c b/net/ipv4/tcp_htcp.c
new file mode 100644
index 0000000..937549b
--- /dev/null
+++ b/net/ipv4/tcp_htcp.c
@@ -0,0 +1,316 @@
+/*
+ * H-TCP congestion control. The algorithm is detailed in:
+ * R.N.Shorten, D.J.Leith:
+ *   "H-TCP: TCP for high-speed and long-distance networks"
+ *   Proc. PFLDnet, Argonne, 2004.
+ * http://www.hamilton.ie/net/htcp3.pdf
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <net/tcp.h>
+
+#define ALPHA_BASE	(1<<7)	/* 1.0 with shift << 7 */
+#define BETA_MIN	(1<<6)	/* 0.5 with shift << 7 */
+#define BETA_MAX	102	/* 0.8 with shift << 7 */
+
+static int use_rtt_scaling __read_mostly = 1;
+module_param(use_rtt_scaling, int, 0644);
+MODULE_PARM_DESC(use_rtt_scaling, "turn on/off RTT scaling");
+
+static int use_bandwidth_switch __read_mostly = 1;
+module_param(use_bandwidth_switch, int, 0644);
+MODULE_PARM_DESC(use_bandwidth_switch, "turn on/off bandwidth switcher");
+
+struct htcp {
+	u32	alpha;		/* Fixed point arith, << 7 */
+	u8	beta;           /* Fixed point arith, << 7 */
+	u8	modeswitch;	/* Delay modeswitch
+				   until we had at least one congestion event */
+	u16	pkts_acked;
+	u32	packetcount;
+	u32	minRTT;
+	u32	maxRTT;
+	u32	last_cong;	/* Time since last congestion event end */
+	u32	undo_last_cong;
+
+	u32	undo_maxRTT;
+	u32	undo_old_maxB;
+
+	/* Bandwidth estimation */
+	u32	minB;
+	u32	maxB;
+	u32	old_maxB;
+	u32	Bi;
+	u32	lasttime;
+};
+
+static inline u32 htcp_cong_time(const struct htcp *ca)
+{
+	return jiffies - ca->last_cong;
+}
+
+static inline u32 htcp_ccount(const struct htcp *ca)
+{
+	return htcp_cong_time(ca) / ca->minRTT;
+}
+
+static inline void htcp_reset(struct htcp *ca)
+{
+	ca->undo_last_cong = ca->last_cong;
+	ca->undo_maxRTT = ca->maxRTT;
+	ca->undo_old_maxB = ca->old_maxB;
+
+	ca->last_cong = jiffies;
+}
+
+static u32 htcp_cwnd_undo(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
+
+	if (ca->undo_last_cong) {
+		ca->last_cong = ca->undo_last_cong;
+		ca->maxRTT = ca->undo_maxRTT;
+		ca->old_maxB = ca->undo_old_maxB;
+		ca->undo_last_cong = 0;
+	}
+
+	return max(tp->snd_cwnd, (tp->snd_ssthresh << 7) / ca->beta);
+}
+
+static inline void measure_rtt(struct sock *sk, u32 srtt)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
+
+	/* keep track of minimum RTT seen so far, minRTT is zero at first */
+	if (ca->minRTT > srtt || !ca->minRTT)
+		ca->minRTT = srtt;
+
+	/* max RTT */
+	if (icsk->icsk_ca_state == TCP_CA_Open) {
+		if (ca->maxRTT < ca->minRTT)
+			ca->maxRTT = ca->minRTT;
+		if (ca->maxRTT < srtt
+		    && srtt <= ca->maxRTT + msecs_to_jiffies(20))
+			ca->maxRTT = srtt;
+	}
+}
+
+static void measure_achieved_throughput(struct sock *sk, u32 pkts_acked, s32 rtt)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
+	u32 now = tcp_time_stamp;
+
+	if (icsk->icsk_ca_state == TCP_CA_Open)
+		ca->pkts_acked = pkts_acked;
+
+	if (rtt > 0)
+		measure_rtt(sk, usecs_to_jiffies(rtt));
+
+	if (!use_bandwidth_switch)
+		return;
+
+	/* achieved throughput calculations */
+	if (icsk->icsk_ca_state != TCP_CA_Open &&
+	    icsk->icsk_ca_state != TCP_CA_Disorder) {
+		ca->packetcount = 0;
+		ca->lasttime = now;
+		return;
+	}
+
+	ca->packetcount += pkts_acked;
+
+	if (ca->packetcount >= tp->snd_cwnd - (ca->alpha >> 7 ? : 1)
+	    && now - ca->lasttime >= ca->minRTT
+	    && ca->minRTT > 0) {
+		__u32 cur_Bi = ca->packetcount * HZ / (now - ca->lasttime);
+
+		if (htcp_ccount(ca) <= 3) {
+			/* just after backoff */
+			ca->minB = ca->maxB = ca->Bi = cur_Bi;
+		} else {
+			ca->Bi = (3 * ca->Bi + cur_Bi) / 4;
+			if (ca->Bi > ca->maxB)
+				ca->maxB = ca->Bi;
+			if (ca->minB > ca->maxB)
+				ca->minB = ca->maxB;
+		}
+		ca->packetcount = 0;
+		ca->lasttime = now;
+	}
+}
+
+static inline void htcp_beta_update(struct htcp *ca, u32 minRTT, u32 maxRTT)
+{
+	if (use_bandwidth_switch) {
+		u32 maxB = ca->maxB;
+		u32 old_maxB = ca->old_maxB;
+		ca->old_maxB = ca->maxB;
+
+		if (!between(5 * maxB, 4 * old_maxB, 6 * old_maxB)) {
+			ca->beta = BETA_MIN;
+			ca->modeswitch = 0;
+			return;
+		}
+	}
+
+	if (ca->modeswitch && minRTT > msecs_to_jiffies(10) && maxRTT) {
+		ca->beta = (minRTT << 7) / maxRTT;
+		if (ca->beta < BETA_MIN)
+			ca->beta = BETA_MIN;
+		else if (ca->beta > BETA_MAX)
+			ca->beta = BETA_MAX;
+	} else {
+		ca->beta = BETA_MIN;
+		ca->modeswitch = 1;
+	}
+}
+
+static inline void htcp_alpha_update(struct htcp *ca)
+{
+	u32 minRTT = ca->minRTT;
+	u32 factor = 1;
+	u32 diff = htcp_cong_time(ca);
+
+	if (diff > HZ) {
+		diff -= HZ;
+		factor = 1 + (10 * diff + ((diff / 2) * (diff / 2) / HZ)) / HZ;
+	}
+
+	if (use_rtt_scaling && minRTT) {
+		u32 scale = (HZ << 3) / (10 * minRTT);
+
+		/* clamping ratio to interval [0.5,10]<<3 */
+		scale = min(max(scale, 1U << 2), 10U << 3);
+		factor = (factor << 3) / scale;
+		if (!factor)
+			factor = 1;
+	}
+
+	ca->alpha = 2 * factor * ((1 << 7) - ca->beta);
+	if (!ca->alpha)
+		ca->alpha = ALPHA_BASE;
+}
+
+/*
+ * After we have the rtt data to calculate beta, we'd still prefer to wait one
+ * rtt before we adjust our beta to ensure we are working from a consistent
+ * data.
+ *
+ * This function should be called when we hit a congestion event since only at
+ * that point do we really have a real sense of maxRTT (the queues en route
+ * were getting just too full now).
+ */
+static void htcp_param_update(struct sock *sk)
+{
+	struct htcp *ca = inet_csk_ca(sk);
+	u32 minRTT = ca->minRTT;
+	u32 maxRTT = ca->maxRTT;
+
+	htcp_beta_update(ca, minRTT, maxRTT);
+	htcp_alpha_update(ca);
+
+	/* add slowly fading memory for maxRTT to accommodate routing changes */
+	if (minRTT > 0 && maxRTT > minRTT)
+		ca->maxRTT = minRTT + ((maxRTT - minRTT) * 95) / 100;
+}
+
+static u32 htcp_recalc_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct htcp *ca = inet_csk_ca(sk);
+
+	htcp_param_update(sk);
+	return max((tp->snd_cwnd * ca->beta) >> 7, 2U);
+}
+
+static void htcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct htcp *ca = inet_csk_ca(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+	else {
+		/* In dangerous area, increase slowly.
+		 * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd
+		 */
+		if ((tp->snd_cwnd_cnt * ca->alpha)>>7 >= tp->snd_cwnd) {
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+			htcp_alpha_update(ca);
+		} else
+			tp->snd_cwnd_cnt += ca->pkts_acked;
+
+		ca->pkts_acked = 1;
+	}
+}
+
+static void htcp_init(struct sock *sk)
+{
+	struct htcp *ca = inet_csk_ca(sk);
+
+	memset(ca, 0, sizeof(struct htcp));
+	ca->alpha = ALPHA_BASE;
+	ca->beta = BETA_MIN;
+	ca->pkts_acked = 1;
+	ca->last_cong = jiffies;
+}
+
+static void htcp_state(struct sock *sk, u8 new_state)
+{
+	switch (new_state) {
+	case TCP_CA_Open:
+		{
+			struct htcp *ca = inet_csk_ca(sk);
+			if (ca->undo_last_cong) {
+				ca->last_cong = jiffies;
+				ca->undo_last_cong = 0;
+			}
+		}
+		break;
+	case TCP_CA_CWR:
+	case TCP_CA_Recovery:
+	case TCP_CA_Loss:
+		htcp_reset(inet_csk_ca(sk));
+		break;
+	}
+}
+
+static struct tcp_congestion_ops htcp = {
+	.init		= htcp_init,
+	.ssthresh	= htcp_recalc_ssthresh,
+	.cong_avoid	= htcp_cong_avoid,
+	.set_state	= htcp_state,
+	.undo_cwnd	= htcp_cwnd_undo,
+	.pkts_acked	= measure_achieved_throughput,
+	.owner		= THIS_MODULE,
+	.name		= "htcp",
+};
+
+static int __init htcp_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct htcp) > ICSK_CA_PRIV_SIZE);
+	BUILD_BUG_ON(BETA_MIN >= BETA_MAX);
+	return tcp_register_congestion_control(&htcp);
+}
+
+static void __exit htcp_unregister(void)
+{
+	tcp_unregister_congestion_control(&htcp);
+}
+
+module_init(htcp_register);
+module_exit(htcp_unregister);
+
+MODULE_AUTHOR("Baruch Even");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("H-TCP");
diff --git a/net/ipv4/tcp_hybla.c b/net/ipv4/tcp_hybla.c
new file mode 100644
index 0000000..c209e05
--- /dev/null
+++ b/net/ipv4/tcp_hybla.c
@@ -0,0 +1,192 @@
+/*
+ * TCP HYBLA
+ *
+ * TCP-HYBLA Congestion control algorithm, based on:
+ *   C.Caini, R.Firrincieli, "TCP-Hybla: A TCP Enhancement
+ *   for Heterogeneous Networks",
+ *   International Journal on satellite Communications,
+ *				       September 2004
+ *    Daniele Lacamera
+ *    root at danielinux.net
+ */
+
+#include <linux/module.h>
+#include <net/tcp.h>
+
+/* Tcp Hybla structure. */
+struct hybla {
+	u8    hybla_en;
+	u32   snd_cwnd_cents; /* Keeps increment values when it is <1, <<7 */
+	u32   rho;	      /* Rho parameter, integer part  */
+	u32   rho2;	      /* Rho * Rho, integer part */
+	u32   rho_3ls;	      /* Rho parameter, <<3 */
+	u32   rho2_7ls;	      /* Rho^2, <<7	*/
+	u32   minrtt;	      /* Minimum smoothed round trip time value seen */
+};
+
+/* Hybla reference round trip time (default= 1/40 sec = 25 ms),
+   expressed in jiffies */
+static int rtt0 = 25;
+module_param(rtt0, int, 0644);
+MODULE_PARM_DESC(rtt0, "reference rout trip time (ms)");
+
+
+/* This is called to refresh values for hybla parameters */
+static inline void hybla_recalc_param (struct sock *sk)
+{
+	struct hybla *ca = inet_csk_ca(sk);
+
+	ca->rho_3ls = max_t(u32, tcp_sk(sk)->srtt / msecs_to_jiffies(rtt0), 8);
+	ca->rho = ca->rho_3ls >> 3;
+	ca->rho2_7ls = (ca->rho_3ls * ca->rho_3ls) << 1;
+	ca->rho2 = ca->rho2_7ls >>7;
+}
+
+static void hybla_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct hybla *ca = inet_csk_ca(sk);
+
+	ca->rho = 0;
+	ca->rho2 = 0;
+	ca->rho_3ls = 0;
+	ca->rho2_7ls = 0;
+	ca->snd_cwnd_cents = 0;
+	ca->hybla_en = 1;
+	tp->snd_cwnd = 2;
+	tp->snd_cwnd_clamp = 65535;
+
+	/* 1st Rho measurement based on initial srtt */
+	hybla_recalc_param(sk);
+
+	/* set minimum rtt as this is the 1st ever seen */
+	ca->minrtt = tp->srtt;
+	tp->snd_cwnd = ca->rho;
+}
+
+static void hybla_state(struct sock *sk, u8 ca_state)
+{
+	struct hybla *ca = inet_csk_ca(sk);
+	ca->hybla_en = (ca_state == TCP_CA_Open);
+}
+
+static inline u32 hybla_fraction(u32 odds)
+{
+	static const u32 fractions[] = {
+		128, 139, 152, 165, 181, 197, 215, 234,
+	};
+
+	return (odds < ARRAY_SIZE(fractions)) ? fractions[odds] : 128;
+}
+
+/* TCP Hybla main routine.
+ * This is the algorithm behavior:
+ *     o Recalc Hybla parameters if min_rtt has changed
+ *     o Give cwnd a new value based on the model proposed
+ *     o remember increments <1
+ */
+static void hybla_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct hybla *ca = inet_csk_ca(sk);
+	u32 increment, odd, rho_fractions;
+	int is_slowstart = 0;
+
+	/*  Recalculate rho only if this srtt is the lowest */
+	if (tp->srtt < ca->minrtt){
+		hybla_recalc_param(sk);
+		ca->minrtt = tp->srtt;
+	}
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (!ca->hybla_en) {
+		tcp_reno_cong_avoid(sk, ack, in_flight);
+		return;
+	}
+
+	if (ca->rho == 0)
+		hybla_recalc_param(sk);
+
+	rho_fractions = ca->rho_3ls - (ca->rho << 3);
+
+	if (tp->snd_cwnd < tp->snd_ssthresh) {
+		/*
+		 * slow start
+		 *      INC = 2^RHO - 1
+		 * This is done by splitting the rho parameter
+		 * into 2 parts: an integer part and a fraction part.
+		 * Inrement<<7 is estimated by doing:
+		 *	       [2^(int+fract)]<<7
+		 * that is equal to:
+		 *	       (2^int)	*  [(2^fract) <<7]
+		 * 2^int is straightly computed as 1<<int,
+		 * while we will use hybla_slowstart_fraction_increment() to
+		 * calculate 2^fract in a <<7 value.
+		 */
+		is_slowstart = 1;
+		increment = ((1 << ca->rho) * hybla_fraction(rho_fractions))
+			- 128;
+	} else {
+		/*
+		 * congestion avoidance
+		 * INC = RHO^2 / W
+		 * as long as increment is estimated as (rho<<7)/window
+		 * it already is <<7 and we can easily count its fractions.
+		 */
+		increment = ca->rho2_7ls / tp->snd_cwnd;
+		if (increment < 128)
+			tp->snd_cwnd_cnt++;
+	}
+
+	odd = increment % 128;
+	tp->snd_cwnd += increment >> 7;
+	ca->snd_cwnd_cents += odd;
+
+	/* check when fractions goes >=128 and increase cwnd by 1. */
+	while (ca->snd_cwnd_cents >= 128) {
+		tp->snd_cwnd++;
+		ca->snd_cwnd_cents -= 128;
+		tp->snd_cwnd_cnt = 0;
+	}
+	/* check when cwnd has not been incremented for a while */
+	if (increment == 0 && odd == 0 && tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+		tp->snd_cwnd++;
+		tp->snd_cwnd_cnt = 0;
+	}
+	/* clamp down slowstart cwnd to ssthresh value. */
+	if (is_slowstart)
+		tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
+
+	tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
+}
+
+static struct tcp_congestion_ops tcp_hybla = {
+	.init		= hybla_init,
+	.ssthresh	= tcp_reno_ssthresh,
+	.min_cwnd	= tcp_reno_min_cwnd,
+	.cong_avoid	= hybla_cong_avoid,
+	.set_state	= hybla_state,
+
+	.owner		= THIS_MODULE,
+	.name		= "hybla"
+};
+
+static int __init hybla_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct hybla) > ICSK_CA_PRIV_SIZE);
+	return tcp_register_congestion_control(&tcp_hybla);
+}
+
+static void __exit hybla_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_hybla);
+}
+
+module_init(hybla_register);
+module_exit(hybla_unregister);
+
+MODULE_AUTHOR("Daniele Lacamera");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Hybla");
diff --git a/net/ipv4/tcp_illinois.c b/net/ipv4/tcp_illinois.c
new file mode 100644
index 0000000..1eba160
--- /dev/null
+++ b/net/ipv4/tcp_illinois.c
@@ -0,0 +1,356 @@
+/*
+ * TCP Illinois congestion control.
+ * Home page:
+ *	http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
+ *
+ * The algorithm is described in:
+ * "TCP-Illinois: A Loss and Delay-Based Congestion Control Algorithm
+ *  for High-Speed Networks"
+ * http://www.ews.uiuc.edu/~shaoliu/papersandslides/liubassri06perf.pdf
+ *
+ * Implemented from description in paper and ns-2 simulation.
+ * Copyright (C) 2007 Stephen Hemminger <shemminger@linux-foundation.org>
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+#include <asm/div64.h>
+#include <net/tcp.h>
+
+#define ALPHA_SHIFT	7
+#define ALPHA_SCALE	(1u<<ALPHA_SHIFT)
+#define ALPHA_MIN	((3*ALPHA_SCALE)/10)	/* ~0.3 */
+#define ALPHA_MAX	(10*ALPHA_SCALE)	/* 10.0 */
+#define ALPHA_BASE	ALPHA_SCALE		/* 1.0 */
+#define U32_MAX		((u32)~0U)
+#define RTT_MAX		(U32_MAX / ALPHA_MAX)	/* 3.3 secs */
+
+#define BETA_SHIFT	6
+#define BETA_SCALE	(1u<<BETA_SHIFT)
+#define BETA_MIN	(BETA_SCALE/8)		/* 0.125 */
+#define BETA_MAX	(BETA_SCALE/2)		/* 0.5 */
+#define BETA_BASE	BETA_MAX
+
+static int win_thresh __read_mostly = 15;
+module_param(win_thresh, int, 0);
+MODULE_PARM_DESC(win_thresh, "Window threshold for starting adaptive sizing");
+
+static int theta __read_mostly = 5;
+module_param(theta, int, 0);
+MODULE_PARM_DESC(theta, "# of fast RTT's before full growth");
+
+/* TCP Illinois Parameters */
+struct illinois {
+	u64	sum_rtt;	/* sum of rtt's measured within last rtt */
+	u16	cnt_rtt;	/* # of rtts measured within last rtt */
+	u32	base_rtt;	/* min of all rtt in usec */
+	u32	max_rtt;	/* max of all rtt in usec */
+	u32	end_seq;	/* right edge of current RTT */
+	u32	alpha;		/* Additive increase */
+	u32	beta;		/* Muliplicative decrease */
+	u16	acked;		/* # packets acked by current ACK */
+	u8	rtt_above;	/* average rtt has gone above threshold */
+	u8	rtt_low;	/* # of rtts measurements below threshold */
+};
+
+static void rtt_reset(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct illinois *ca = inet_csk_ca(sk);
+
+	ca->end_seq = tp->snd_nxt;
+	ca->cnt_rtt = 0;
+	ca->sum_rtt = 0;
+
+	/* TODO: age max_rtt? */
+}
+
+static void tcp_illinois_init(struct sock *sk)
+{
+	struct illinois *ca = inet_csk_ca(sk);
+
+	ca->alpha = ALPHA_MAX;
+	ca->beta = BETA_BASE;
+	ca->base_rtt = 0x7fffffff;
+	ca->max_rtt = 0;
+
+	ca->acked = 0;
+	ca->rtt_low = 0;
+	ca->rtt_above = 0;
+
+	rtt_reset(sk);
+}
+
+/* Measure RTT for each ack. */
+static void tcp_illinois_acked(struct sock *sk, u32 pkts_acked, s32 rtt)
+{
+	struct illinois *ca = inet_csk_ca(sk);
+
+	ca->acked = pkts_acked;
+
+	/* dup ack, no rtt sample */
+	if (rtt < 0)
+		return;
+
+	/* ignore bogus values, this prevents wraparound in alpha math */
+	if (rtt > RTT_MAX)
+		rtt = RTT_MAX;
+
+	/* keep track of minimum RTT seen so far */
+	if (ca->base_rtt > rtt)
+		ca->base_rtt = rtt;
+
+	/* and max */
+	if (ca->max_rtt < rtt)
+		ca->max_rtt = rtt;
+
+	++ca->cnt_rtt;
+	ca->sum_rtt += rtt;
+}
+
+/* Maximum queuing delay */
+static inline u32 max_delay(const struct illinois *ca)
+{
+	return ca->max_rtt - ca->base_rtt;
+}
+
+/* Average queuing delay */
+static inline u32 avg_delay(const struct illinois *ca)
+{
+	u64 t = ca->sum_rtt;
+
+	do_div(t, ca->cnt_rtt);
+	return t - ca->base_rtt;
+}
+
+/*
+ * Compute value of alpha used for additive increase.
+ * If small window then use 1.0, equivalent to Reno.
+ *
+ * For larger windows, adjust based on average delay.
+ * A. If average delay is at minimum (we are uncongested),
+ *    then use large alpha (10.0) to increase faster.
+ * B. If average delay is at maximum (getting congested)
+ *    then use small alpha (0.3)
+ *
+ * The result is a convex window growth curve.
+ */
+static u32 alpha(struct illinois *ca, u32 da, u32 dm)
+{
+	u32 d1 = dm / 100;	/* Low threshold */
+
+	if (da <= d1) {
+		/* If never got out of low delay zone, then use max */
+		if (!ca->rtt_above)
+			return ALPHA_MAX;
+
+		/* Wait for 5 good RTT's before allowing alpha to go alpha max.
+		 * This prevents one good RTT from causing sudden window increase.
+		 */
+		if (++ca->rtt_low < theta)
+			return ca->alpha;
+
+		ca->rtt_low = 0;
+		ca->rtt_above = 0;
+		return ALPHA_MAX;
+	}
+
+	ca->rtt_above = 1;
+
+	/*
+	 * Based on:
+	 *
+	 *      (dm - d1) amin amax
+	 * k1 = -------------------
+	 *         amax - amin
+	 *
+	 *       (dm - d1) amin
+	 * k2 = ----------------  - d1
+	 *        amax - amin
+	 *
+	 *             k1
+	 * alpha = ----------
+	 *          k2 + da
+	 */
+
+	dm -= d1;
+	da -= d1;
+	return (dm * ALPHA_MAX) /
+		(dm + (da  * (ALPHA_MAX - ALPHA_MIN)) / ALPHA_MIN);
+}
+
+/*
+ * Beta used for multiplicative decrease.
+ * For small window sizes returns same value as Reno (0.5)
+ *
+ * If delay is small (10% of max) then beta = 1/8
+ * If delay is up to 80% of max then beta = 1/2
+ * In between is a linear function
+ */
+static u32 beta(u32 da, u32 dm)
+{
+	u32 d2, d3;
+
+	d2 = dm / 10;
+	if (da <= d2)
+		return BETA_MIN;
+
+	d3 = (8 * dm) / 10;
+	if (da >= d3 || d3 <= d2)
+		return BETA_MAX;
+
+	/*
+	 * Based on:
+	 *
+	 *       bmin d3 - bmax d2
+	 * k3 = -------------------
+	 *         d3 - d2
+	 *
+	 *       bmax - bmin
+	 * k4 = -------------
+	 *         d3 - d2
+	 *
+	 * b = k3 + k4 da
+	 */
+	return (BETA_MIN * d3 - BETA_MAX * d2 + (BETA_MAX - BETA_MIN) * da)
+		/ (d3 - d2);
+}
+
+/* Update alpha and beta values once per RTT */
+static void update_params(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct illinois *ca = inet_csk_ca(sk);
+
+	if (tp->snd_cwnd < win_thresh) {
+		ca->alpha = ALPHA_BASE;
+		ca->beta = BETA_BASE;
+	} else if (ca->cnt_rtt > 0) {
+		u32 dm = max_delay(ca);
+		u32 da = avg_delay(ca);
+
+		ca->alpha = alpha(ca, da, dm);
+		ca->beta = beta(da, dm);
+	}
+
+	rtt_reset(sk);
+}
+
+/*
+ * In case of loss, reset to default values
+ */
+static void tcp_illinois_state(struct sock *sk, u8 new_state)
+{
+	struct illinois *ca = inet_csk_ca(sk);
+
+	if (new_state == TCP_CA_Loss) {
+		ca->alpha = ALPHA_BASE;
+		ca->beta = BETA_BASE;
+		ca->rtt_low = 0;
+		ca->rtt_above = 0;
+		rtt_reset(sk);
+	}
+}
+
+/*
+ * Increase window in response to successful acknowledgment.
+ */
+static void tcp_illinois_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct illinois *ca = inet_csk_ca(sk);
+
+	if (after(ack, ca->end_seq))
+		update_params(sk);
+
+	/* RFC2861 only increase cwnd if fully utilized */
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	/* In slow start */
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+
+	else {
+		u32 delta;
+
+		/* snd_cwnd_cnt is # of packets since last cwnd increment */
+		tp->snd_cwnd_cnt += ca->acked;
+		ca->acked = 1;
+
+		/* This is close approximation of:
+		 * tp->snd_cwnd += alpha/tp->snd_cwnd
+		*/
+		delta = (tp->snd_cwnd_cnt * ca->alpha) >> ALPHA_SHIFT;
+		if (delta >= tp->snd_cwnd) {
+			tp->snd_cwnd = min(tp->snd_cwnd + delta / tp->snd_cwnd,
+					   (u32) tp->snd_cwnd_clamp);
+			tp->snd_cwnd_cnt = 0;
+		}
+	}
+}
+
+static u32 tcp_illinois_ssthresh(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct illinois *ca = inet_csk_ca(sk);
+
+	/* Multiplicative decrease */
+	return max(tp->snd_cwnd - ((tp->snd_cwnd * ca->beta) >> BETA_SHIFT), 2U);
+}
+
+
+/* Extract info for Tcp socket info provided via netlink. */
+static void tcp_illinois_info(struct sock *sk, u32 ext,
+			      struct sk_buff *skb)
+{
+	const struct illinois *ca = inet_csk_ca(sk);
+
+	if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
+		struct tcpvegas_info info = {
+			.tcpv_enabled = 1,
+			.tcpv_rttcnt = ca->cnt_rtt,
+			.tcpv_minrtt = ca->base_rtt,
+		};
+		u64 t = ca->sum_rtt;
+
+		do_div(t, ca->cnt_rtt);
+		info.tcpv_rtt = t;
+
+		nla_put(skb, INET_DIAG_VEGASINFO, sizeof(info), &info);
+	}
+}
+
+static struct tcp_congestion_ops tcp_illinois = {
+	.flags		= TCP_CONG_RTT_STAMP,
+	.init		= tcp_illinois_init,
+	.ssthresh	= tcp_illinois_ssthresh,
+	.min_cwnd	= tcp_reno_min_cwnd,
+	.cong_avoid	= tcp_illinois_cong_avoid,
+	.set_state	= tcp_illinois_state,
+	.get_info	= tcp_illinois_info,
+	.pkts_acked	= tcp_illinois_acked,
+
+	.owner		= THIS_MODULE,
+	.name		= "illinois",
+};
+
+static int __init tcp_illinois_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct illinois) > ICSK_CA_PRIV_SIZE);
+	return tcp_register_congestion_control(&tcp_illinois);
+}
+
+static void __exit tcp_illinois_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_illinois);
+}
+
+module_init(tcp_illinois_register);
+module_exit(tcp_illinois_unregister);
+
+MODULE_AUTHOR("Stephen Hemminger, Shao Liu");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Illinois");
+MODULE_VERSION("1.0");
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
new file mode 100644
index 0000000..d77c0d2
--- /dev/null
+++ b/net/ipv4/tcp_input.c
@@ -0,0 +1,5496 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *		Corey Minyard <wf-rch!minyard@relay.EU.net>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ *		Linus Torvalds, <torvalds@cs.helsinki.fi>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Matthew Dillon, <dillon@apollo.west.oic.com>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ */
+
+/*
+ * Changes:
+ *		Pedro Roque	:	Fast Retransmit/Recovery.
+ *					Two receive queues.
+ *					Retransmit queue handled by TCP.
+ *					Better retransmit timer handling.
+ *					New congestion avoidance.
+ *					Header prediction.
+ *					Variable renaming.
+ *
+ *		Eric		:	Fast Retransmit.
+ *		Randy Scott	:	MSS option defines.
+ *		Eric Schenk	:	Fixes to slow start algorithm.
+ *		Eric Schenk	:	Yet another double ACK bug.
+ *		Eric Schenk	:	Delayed ACK bug fixes.
+ *		Eric Schenk	:	Floyd style fast retrans war avoidance.
+ *		David S. Miller	:	Don't allow zero congestion window.
+ *		Eric Schenk	:	Fix retransmitter so that it sends
+ *					next packet on ack of previous packet.
+ *		Andi Kleen	:	Moved open_request checking here
+ *					and process RSTs for open_requests.
+ *		Andi Kleen	:	Better prune_queue, and other fixes.
+ *		Andrey Savochkin:	Fix RTT measurements in the presence of
+ *					timestamps.
+ *		Andrey Savochkin:	Check sequence numbers correctly when
+ *					removing SACKs due to in sequence incoming
+ *					data segments.
+ *		Andi Kleen:		Make sure we never ack data there is not
+ *					enough room for. Also make this condition
+ *					a fatal error if it might still happen.
+ *		Andi Kleen:		Add tcp_measure_rcv_mss to make
+ *					connections with MSS<min(MTU,ann. MSS)
+ *					work without delayed acks.
+ *		Andi Kleen:		Process packets with PSH set in the
+ *					fast path.
+ *		J Hadi Salim:		ECN support
+ *	 	Andrei Gurtov,
+ *		Pasi Sarolahti,
+ *		Panu Kuhlberg:		Experimental audit of TCP (re)transmission
+ *					engine. Lots of bugs are found.
+ *		Pasi Sarolahti:		F-RTO for dealing with spurious RTOs
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <net/dst.h>
+#include <net/tcp.h>
+#include <net/inet_common.h>
+#include <linux/ipsec.h>
+#include <asm/unaligned.h>
+#include <net/netdma.h>
+
+int sysctl_tcp_timestamps __read_mostly = 1;
+int sysctl_tcp_window_scaling __read_mostly = 1;
+int sysctl_tcp_sack __read_mostly = 1;
+int sysctl_tcp_fack __read_mostly = 1;
+int sysctl_tcp_reordering __read_mostly = TCP_FASTRETRANS_THRESH;
+int sysctl_tcp_ecn __read_mostly;
+int sysctl_tcp_dsack __read_mostly = 1;
+int sysctl_tcp_app_win __read_mostly = 31;
+int sysctl_tcp_adv_win_scale __read_mostly = 2;
+
+int sysctl_tcp_stdurg __read_mostly;
+int sysctl_tcp_rfc1337 __read_mostly;
+int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
+int sysctl_tcp_frto __read_mostly = 2;
+int sysctl_tcp_frto_response __read_mostly;
+int sysctl_tcp_nometrics_save __read_mostly;
+
+int sysctl_tcp_moderate_rcvbuf __read_mostly = 1;
+int sysctl_tcp_abc __read_mostly;
+
+#define FLAG_DATA		0x01 /* Incoming frame contained data.		*/
+#define FLAG_WIN_UPDATE		0x02 /* Incoming ACK was a window update.	*/
+#define FLAG_DATA_ACKED		0x04 /* This ACK acknowledged new data.		*/
+#define FLAG_RETRANS_DATA_ACKED	0x08 /* "" "" some of which was retransmitted.	*/
+#define FLAG_SYN_ACKED		0x10 /* This ACK acknowledged SYN.		*/
+#define FLAG_DATA_SACKED	0x20 /* New SACK.				*/
+#define FLAG_ECE		0x40 /* ECE in this ACK				*/
+#define FLAG_DATA_LOST		0x80 /* SACK detected data lossage.		*/
+#define FLAG_SLOWPATH		0x100 /* Do not skip RFC checks for window update.*/
+#define FLAG_ONLY_ORIG_SACKED	0x200 /* SACKs only non-rexmit sent before RTO */
+#define FLAG_SND_UNA_ADVANCED	0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */
+#define FLAG_DSACKING_ACK	0x800 /* SACK blocks contained D-SACK info */
+#define FLAG_NONHEAD_RETRANS_ACKED	0x1000 /* Non-head rexmitted data was ACKed */
+#define FLAG_SACK_RENEGING	0x2000 /* snd_una advanced to a sacked seq */
+
+#define FLAG_ACKED		(FLAG_DATA_ACKED|FLAG_SYN_ACKED)
+#define FLAG_NOT_DUP		(FLAG_DATA|FLAG_WIN_UPDATE|FLAG_ACKED)
+#define FLAG_CA_ALERT		(FLAG_DATA_SACKED|FLAG_ECE)
+#define FLAG_FORWARD_PROGRESS	(FLAG_ACKED|FLAG_DATA_SACKED)
+#define FLAG_ANY_PROGRESS	(FLAG_FORWARD_PROGRESS|FLAG_SND_UNA_ADVANCED)
+
+#define TCP_REMNANT (TCP_FLAG_FIN|TCP_FLAG_URG|TCP_FLAG_SYN|TCP_FLAG_PSH)
+#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH))
+
+/* Adapt the MSS value used to make delayed ack decision to the
+ * real world.
+ */
+static void tcp_measure_rcv_mss(struct sock *sk, const struct sk_buff *skb)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	const unsigned int lss = icsk->icsk_ack.last_seg_size;
+	unsigned int len;
+
+	icsk->icsk_ack.last_seg_size = 0;
+
+	/* skb->len may jitter because of SACKs, even if peer
+	 * sends good full-sized frames.
+	 */
+	len = skb_shinfo(skb)->gso_size ? : skb->len;
+	if (len >= icsk->icsk_ack.rcv_mss) {
+		icsk->icsk_ack.rcv_mss = len;
+	} else {
+		/* Otherwise, we make more careful check taking into account,
+		 * that SACKs block is variable.
+		 *
+		 * "len" is invariant segment length, including TCP header.
+		 */
+		len += skb->data - skb_transport_header(skb);
+		if (len >= TCP_MIN_RCVMSS + sizeof(struct tcphdr) ||
+		    /* If PSH is not set, packet should be
+		     * full sized, provided peer TCP is not badly broken.
+		     * This observation (if it is correct 8)) allows
+		     * to handle super-low mtu links fairly.
+		     */
+		    (len >= TCP_MIN_MSS + sizeof(struct tcphdr) &&
+		     !(tcp_flag_word(tcp_hdr(skb)) & TCP_REMNANT))) {
+			/* Subtract also invariant (if peer is RFC compliant),
+			 * tcp header plus fixed timestamp option length.
+			 * Resulting "len" is MSS free of SACK jitter.
+			 */
+			len -= tcp_sk(sk)->tcp_header_len;
+			icsk->icsk_ack.last_seg_size = len;
+			if (len == lss) {
+				icsk->icsk_ack.rcv_mss = len;
+				return;
+			}
+		}
+		if (icsk->icsk_ack.pending & ICSK_ACK_PUSHED)
+			icsk->icsk_ack.pending |= ICSK_ACK_PUSHED2;
+		icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
+	}
+}
+
+static void tcp_incr_quickack(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	unsigned quickacks = tcp_sk(sk)->rcv_wnd / (2 * icsk->icsk_ack.rcv_mss);
+
+	if (quickacks == 0)
+		quickacks = 2;
+	if (quickacks > icsk->icsk_ack.quick)
+		icsk->icsk_ack.quick = min(quickacks, TCP_MAX_QUICKACKS);
+}
+
+void tcp_enter_quickack_mode(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	tcp_incr_quickack(sk);
+	icsk->icsk_ack.pingpong = 0;
+	icsk->icsk_ack.ato = TCP_ATO_MIN;
+}
+
+/* Send ACKs quickly, if "quick" count is not exhausted
+ * and the session is not interactive.
+ */
+
+static inline int tcp_in_quickack_mode(const struct sock *sk)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	return icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong;
+}
+
+static inline void TCP_ECN_queue_cwr(struct tcp_sock *tp)
+{
+	if (tp->ecn_flags & TCP_ECN_OK)
+		tp->ecn_flags |= TCP_ECN_QUEUE_CWR;
+}
+
+static inline void TCP_ECN_accept_cwr(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	if (tcp_hdr(skb)->cwr)
+		tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
+}
+
+static inline void TCP_ECN_withdraw_cwr(struct tcp_sock *tp)
+{
+	tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
+}
+
+static inline void TCP_ECN_check_ce(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	if (tp->ecn_flags & TCP_ECN_OK) {
+		if (INET_ECN_is_ce(TCP_SKB_CB(skb)->flags))
+			tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
+		/* Funny extension: if ECT is not set on a segment,
+		 * it is surely retransmit. It is not in ECN RFC,
+		 * but Linux follows this rule. */
+		else if (INET_ECN_is_not_ect((TCP_SKB_CB(skb)->flags)))
+			tcp_enter_quickack_mode((struct sock *)tp);
+	}
+}
+
+static inline void TCP_ECN_rcv_synack(struct tcp_sock *tp, struct tcphdr *th)
+{
+	if ((tp->ecn_flags & TCP_ECN_OK) && (!th->ece || th->cwr))
+		tp->ecn_flags &= ~TCP_ECN_OK;
+}
+
+static inline void TCP_ECN_rcv_syn(struct tcp_sock *tp, struct tcphdr *th)
+{
+	if ((tp->ecn_flags & TCP_ECN_OK) && (!th->ece || !th->cwr))
+		tp->ecn_flags &= ~TCP_ECN_OK;
+}
+
+static inline int TCP_ECN_rcv_ecn_echo(struct tcp_sock *tp, struct tcphdr *th)
+{
+	if (th->ece && !th->syn && (tp->ecn_flags & TCP_ECN_OK))
+		return 1;
+	return 0;
+}
+
+/* Buffer size and advertised window tuning.
+ *
+ * 1. Tuning sk->sk_sndbuf, when connection enters established state.
+ */
+
+static void tcp_fixup_sndbuf(struct sock *sk)
+{
+	int sndmem = tcp_sk(sk)->rx_opt.mss_clamp + MAX_TCP_HEADER + 16 +
+		     sizeof(struct sk_buff);
+
+	if (sk->sk_sndbuf < 3 * sndmem)
+		sk->sk_sndbuf = min(3 * sndmem, sysctl_tcp_wmem[2]);
+}
+
+/* 2. Tuning advertised window (window_clamp, rcv_ssthresh)
+ *
+ * All tcp_full_space() is split to two parts: "network" buffer, allocated
+ * forward and advertised in receiver window (tp->rcv_wnd) and
+ * "application buffer", required to isolate scheduling/application
+ * latencies from network.
+ * window_clamp is maximal advertised window. It can be less than
+ * tcp_full_space(), in this case tcp_full_space() - window_clamp
+ * is reserved for "application" buffer. The less window_clamp is
+ * the smoother our behaviour from viewpoint of network, but the lower
+ * throughput and the higher sensitivity of the connection to losses. 8)
+ *
+ * rcv_ssthresh is more strict window_clamp used at "slow start"
+ * phase to predict further behaviour of this connection.
+ * It is used for two goals:
+ * - to enforce header prediction at sender, even when application
+ *   requires some significant "application buffer". It is check #1.
+ * - to prevent pruning of receive queue because of misprediction
+ *   of receiver window. Check #2.
+ *
+ * The scheme does not work when sender sends good segments opening
+ * window and then starts to feed us spaghetti. But it should work
+ * in common situations. Otherwise, we have to rely on queue collapsing.
+ */
+
+/* Slow part of check#2. */
+static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	/* Optimize this! */
+	int truesize = tcp_win_from_space(skb->truesize) >> 1;
+	int window = tcp_win_from_space(sysctl_tcp_rmem[2]) >> 1;
+
+	while (tp->rcv_ssthresh <= window) {
+		if (truesize <= skb->len)
+			return 2 * inet_csk(sk)->icsk_ack.rcv_mss;
+
+		truesize >>= 1;
+		window >>= 1;
+	}
+	return 0;
+}
+
+static void tcp_grow_window(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* Check #1 */
+	if (tp->rcv_ssthresh < tp->window_clamp &&
+	    (int)tp->rcv_ssthresh < tcp_space(sk) &&
+	    !tcp_memory_pressure) {
+		int incr;
+
+		/* Check #2. Increase window, if skb with such overhead
+		 * will fit to rcvbuf in future.
+		 */
+		if (tcp_win_from_space(skb->truesize) <= skb->len)
+			incr = 2 * tp->advmss;
+		else
+			incr = __tcp_grow_window(sk, skb);
+
+		if (incr) {
+			tp->rcv_ssthresh = min(tp->rcv_ssthresh + incr,
+					       tp->window_clamp);
+			inet_csk(sk)->icsk_ack.quick |= 1;
+		}
+	}
+}
+
+/* 3. Tuning rcvbuf, when connection enters established state. */
+
+static void tcp_fixup_rcvbuf(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int rcvmem = tp->advmss + MAX_TCP_HEADER + 16 + sizeof(struct sk_buff);
+
+	/* Try to select rcvbuf so that 4 mss-sized segments
+	 * will fit to window and corresponding skbs will fit to our rcvbuf.
+	 * (was 3; 4 is minimum to allow fast retransmit to work.)
+	 */
+	while (tcp_win_from_space(rcvmem) < tp->advmss)
+		rcvmem += 128;
+	if (sk->sk_rcvbuf < 4 * rcvmem)
+		sk->sk_rcvbuf = min(4 * rcvmem, sysctl_tcp_rmem[2]);
+}
+
+/* 4. Try to fixup all. It is made immediately after connection enters
+ *    established state.
+ */
+static void tcp_init_buffer_space(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int maxwin;
+
+	if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK))
+		tcp_fixup_rcvbuf(sk);
+	if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK))
+		tcp_fixup_sndbuf(sk);
+
+	tp->rcvq_space.space = tp->rcv_wnd;
+
+	maxwin = tcp_full_space(sk);
+
+	if (tp->window_clamp >= maxwin) {
+		tp->window_clamp = maxwin;
+
+		if (sysctl_tcp_app_win && maxwin > 4 * tp->advmss)
+			tp->window_clamp = max(maxwin -
+					       (maxwin >> sysctl_tcp_app_win),
+					       4 * tp->advmss);
+	}
+
+	/* Force reservation of one segment. */
+	if (sysctl_tcp_app_win &&
+	    tp->window_clamp > 2 * tp->advmss &&
+	    tp->window_clamp + tp->advmss > maxwin)
+		tp->window_clamp = max(2 * tp->advmss, maxwin - tp->advmss);
+
+	tp->rcv_ssthresh = min(tp->rcv_ssthresh, tp->window_clamp);
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+}
+
+/* 5. Recalculate window clamp after socket hit its memory bounds. */
+static void tcp_clamp_window(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	icsk->icsk_ack.quick = 0;
+
+	if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
+	    !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
+	    !tcp_memory_pressure &&
+	    atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) {
+		sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
+				    sysctl_tcp_rmem[2]);
+	}
+	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
+		tp->rcv_ssthresh = min(tp->window_clamp, 2U * tp->advmss);
+}
+
+/* Initialize RCV_MSS value.
+ * RCV_MSS is an our guess about MSS used by the peer.
+ * We haven't any direct information about the MSS.
+ * It's better to underestimate the RCV_MSS rather than overestimate.
+ * Overestimations make us ACKing less frequently than needed.
+ * Underestimations are more easy to detect and fix by tcp_measure_rcv_mss().
+ */
+void tcp_initialize_rcv_mss(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned int hint = min_t(unsigned int, tp->advmss, tp->mss_cache);
+
+	hint = min(hint, tp->rcv_wnd / 2);
+	hint = min(hint, TCP_MIN_RCVMSS);
+	hint = max(hint, TCP_MIN_MSS);
+
+	inet_csk(sk)->icsk_ack.rcv_mss = hint;
+}
+
+/* Receiver "autotuning" code.
+ *
+ * The algorithm for RTT estimation w/o timestamps is based on
+ * Dynamic Right-Sizing (DRS) by Wu Feng and Mike Fisk of LANL.
+ * <http://www.lanl.gov/radiant/website/pubs/drs/lacsi2001.ps>
+ *
+ * More detail on this code can be found at
+ * <http://www.psc.edu/~jheffner/senior_thesis.ps>,
+ * though this reference is out of date.  A new paper
+ * is pending.
+ */
+static void tcp_rcv_rtt_update(struct tcp_sock *tp, u32 sample, int win_dep)
+{
+	u32 new_sample = tp->rcv_rtt_est.rtt;
+	long m = sample;
+
+	if (m == 0)
+		m = 1;
+
+	if (new_sample != 0) {
+		/* If we sample in larger samples in the non-timestamp
+		 * case, we could grossly overestimate the RTT especially
+		 * with chatty applications or bulk transfer apps which
+		 * are stalled on filesystem I/O.
+		 *
+		 * Also, since we are only going for a minimum in the
+		 * non-timestamp case, we do not smooth things out
+		 * else with timestamps disabled convergence takes too
+		 * long.
+		 */
+		if (!win_dep) {
+			m -= (new_sample >> 3);
+			new_sample += m;
+		} else if (m < new_sample)
+			new_sample = m << 3;
+	} else {
+		/* No previous measure. */
+		new_sample = m << 3;
+	}
+
+	if (tp->rcv_rtt_est.rtt != new_sample)
+		tp->rcv_rtt_est.rtt = new_sample;
+}
+
+static inline void tcp_rcv_rtt_measure(struct tcp_sock *tp)
+{
+	if (tp->rcv_rtt_est.time == 0)
+		goto new_measure;
+	if (before(tp->rcv_nxt, tp->rcv_rtt_est.seq))
+		return;
+	tcp_rcv_rtt_update(tp, jiffies - tp->rcv_rtt_est.time, 1);
+
+new_measure:
+	tp->rcv_rtt_est.seq = tp->rcv_nxt + tp->rcv_wnd;
+	tp->rcv_rtt_est.time = tcp_time_stamp;
+}
+
+static inline void tcp_rcv_rtt_measure_ts(struct sock *sk,
+					  const struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	if (tp->rx_opt.rcv_tsecr &&
+	    (TCP_SKB_CB(skb)->end_seq -
+	     TCP_SKB_CB(skb)->seq >= inet_csk(sk)->icsk_ack.rcv_mss))
+		tcp_rcv_rtt_update(tp, tcp_time_stamp - tp->rx_opt.rcv_tsecr, 0);
+}
+
+/*
+ * This function should be called every time data is copied to user space.
+ * It calculates the appropriate TCP receive buffer space.
+ */
+void tcp_rcv_space_adjust(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int time;
+	int space;
+
+	if (tp->rcvq_space.time == 0)
+		goto new_measure;
+
+	time = tcp_time_stamp - tp->rcvq_space.time;
+	if (time < (tp->rcv_rtt_est.rtt >> 3) || tp->rcv_rtt_est.rtt == 0)
+		return;
+
+	space = 2 * (tp->copied_seq - tp->rcvq_space.seq);
+
+	space = max(tp->rcvq_space.space, space);
+
+	if (tp->rcvq_space.space != space) {
+		int rcvmem;
+
+		tp->rcvq_space.space = space;
+
+		if (sysctl_tcp_moderate_rcvbuf &&
+		    !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
+			int new_clamp = space;
+
+			/* Receive space grows, normalize in order to
+			 * take into account packet headers and sk_buff
+			 * structure overhead.
+			 */
+			space /= tp->advmss;
+			if (!space)
+				space = 1;
+			rcvmem = (tp->advmss + MAX_TCP_HEADER +
+				  16 + sizeof(struct sk_buff));
+			while (tcp_win_from_space(rcvmem) < tp->advmss)
+				rcvmem += 128;
+			space *= rcvmem;
+			space = min(space, sysctl_tcp_rmem[2]);
+			if (space > sk->sk_rcvbuf) {
+				sk->sk_rcvbuf = space;
+
+				/* Make the window clamp follow along.  */
+				tp->window_clamp = new_clamp;
+			}
+		}
+	}
+
+new_measure:
+	tp->rcvq_space.seq = tp->copied_seq;
+	tp->rcvq_space.time = tcp_time_stamp;
+}
+
+/* There is something which you must keep in mind when you analyze the
+ * behavior of the tp->ato delayed ack timeout interval.  When a
+ * connection starts up, we want to ack as quickly as possible.  The
+ * problem is that "good" TCP's do slow start at the beginning of data
+ * transmission.  The means that until we send the first few ACK's the
+ * sender will sit on his end and only queue most of his data, because
+ * he can only send snd_cwnd unacked packets at any given time.  For
+ * each ACK we send, he increments snd_cwnd and transmits more of his
+ * queue.  -DaveM
+ */
+static void tcp_event_data_recv(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	u32 now;
+
+	inet_csk_schedule_ack(sk);
+
+	tcp_measure_rcv_mss(sk, skb);
+
+	tcp_rcv_rtt_measure(tp);
+
+	now = tcp_time_stamp;
+
+	if (!icsk->icsk_ack.ato) {
+		/* The _first_ data packet received, initialize
+		 * delayed ACK engine.
+		 */
+		tcp_incr_quickack(sk);
+		icsk->icsk_ack.ato = TCP_ATO_MIN;
+	} else {
+		int m = now - icsk->icsk_ack.lrcvtime;
+
+		if (m <= TCP_ATO_MIN / 2) {
+			/* The fastest case is the first. */
+			icsk->icsk_ack.ato = (icsk->icsk_ack.ato >> 1) + TCP_ATO_MIN / 2;
+		} else if (m < icsk->icsk_ack.ato) {
+			icsk->icsk_ack.ato = (icsk->icsk_ack.ato >> 1) + m;
+			if (icsk->icsk_ack.ato > icsk->icsk_rto)
+				icsk->icsk_ack.ato = icsk->icsk_rto;
+		} else if (m > icsk->icsk_rto) {
+			/* Too long gap. Apparently sender failed to
+			 * restart window, so that we send ACKs quickly.
+			 */
+			tcp_incr_quickack(sk);
+			sk_mem_reclaim(sk);
+		}
+	}
+	icsk->icsk_ack.lrcvtime = now;
+
+	TCP_ECN_check_ce(tp, skb);
+
+	if (skb->len >= 128)
+		tcp_grow_window(sk, skb);
+}
+
+static u32 tcp_rto_min(struct sock *sk)
+{
+	struct dst_entry *dst = __sk_dst_get(sk);
+	u32 rto_min = TCP_RTO_MIN;
+
+	if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
+		rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
+	return rto_min;
+}
+
+/* Called to compute a smoothed rtt estimate. The data fed to this
+ * routine either comes from timestamps, or from segments that were
+ * known _not_ to have been retransmitted [see Karn/Partridge
+ * Proceedings SIGCOMM 87]. The algorithm is from the SIGCOMM 88
+ * piece by Van Jacobson.
+ * NOTE: the next three routines used to be one big routine.
+ * To save cycles in the RFC 1323 implementation it was better to break
+ * it up into three procedures. -- erics
+ */
+static void tcp_rtt_estimator(struct sock *sk, const __u32 mrtt)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	long m = mrtt; /* RTT */
+
+	/*	The following amusing code comes from Jacobson's
+	 *	article in SIGCOMM '88.  Note that rtt and mdev
+	 *	are scaled versions of rtt and mean deviation.
+	 *	This is designed to be as fast as possible
+	 *	m stands for "measurement".
+	 *
+	 *	On a 1990 paper the rto value is changed to:
+	 *	RTO = rtt + 4 * mdev
+	 *
+	 * Funny. This algorithm seems to be very broken.
+	 * These formulae increase RTO, when it should be decreased, increase
+	 * too slowly, when it should be increased quickly, decrease too quickly
+	 * etc. I guess in BSD RTO takes ONE value, so that it is absolutely
+	 * does not matter how to _calculate_ it. Seems, it was trap
+	 * that VJ failed to avoid. 8)
+	 */
+	if (m == 0)
+		m = 1;
+	if (tp->srtt != 0) {
+		m -= (tp->srtt >> 3);	/* m is now error in rtt est */
+		tp->srtt += m;		/* rtt = 7/8 rtt + 1/8 new */
+		if (m < 0) {
+			m = -m;		/* m is now abs(error) */
+			m -= (tp->mdev >> 2);   /* similar update on mdev */
+			/* This is similar to one of Eifel findings.
+			 * Eifel blocks mdev updates when rtt decreases.
+			 * This solution is a bit different: we use finer gain
+			 * for mdev in this case (alpha*beta).
+			 * Like Eifel it also prevents growth of rto,
+			 * but also it limits too fast rto decreases,
+			 * happening in pure Eifel.
+			 */
+			if (m > 0)
+				m >>= 3;
+		} else {
+			m -= (tp->mdev >> 2);   /* similar update on mdev */
+		}
+		tp->mdev += m;	    	/* mdev = 3/4 mdev + 1/4 new */
+		if (tp->mdev > tp->mdev_max) {
+			tp->mdev_max = tp->mdev;
+			if (tp->mdev_max > tp->rttvar)
+				tp->rttvar = tp->mdev_max;
+		}
+		if (after(tp->snd_una, tp->rtt_seq)) {
+			if (tp->mdev_max < tp->rttvar)
+				tp->rttvar -= (tp->rttvar - tp->mdev_max) >> 2;
+			tp->rtt_seq = tp->snd_nxt;
+			tp->mdev_max = tcp_rto_min(sk);
+		}
+	} else {
+		/* no previous measure. */
+		tp->srtt = m << 3;	/* take the measured time to be rtt */
+		tp->mdev = m << 1;	/* make sure rto = 3*rtt */
+		tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
+		tp->rtt_seq = tp->snd_nxt;
+	}
+}
+
+/* Calculate rto without backoff.  This is the second half of Van Jacobson's
+ * routine referred to above.
+ */
+static inline void tcp_set_rto(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	/* Old crap is replaced with new one. 8)
+	 *
+	 * More seriously:
+	 * 1. If rtt variance happened to be less 50msec, it is hallucination.
+	 *    It cannot be less due to utterly erratic ACK generation made
+	 *    at least by solaris and freebsd. "Erratic ACKs" has _nothing_
+	 *    to do with delayed acks, because at cwnd>2 true delack timeout
+	 *    is invisible. Actually, Linux-2.4 also generates erratic
+	 *    ACKs in some circumstances.
+	 */
+	inet_csk(sk)->icsk_rto = (tp->srtt >> 3) + tp->rttvar;
+
+	/* 2. Fixups made earlier cannot be right.
+	 *    If we do not estimate RTO correctly without them,
+	 *    all the algo is pure shit and should be replaced
+	 *    with correct one. It is exactly, which we pretend to do.
+	 */
+}
+
+/* NOTE: clamping at TCP_RTO_MIN is not required, current algo
+ * guarantees that rto is higher.
+ */
+static inline void tcp_bound_rto(struct sock *sk)
+{
+	if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX)
+		inet_csk(sk)->icsk_rto = TCP_RTO_MAX;
+}
+
+/* Save metrics learned by this TCP session.
+   This function is called only, when TCP finishes successfully
+   i.e. when it enters TIME-WAIT or goes from LAST-ACK to CLOSE.
+ */
+void tcp_update_metrics(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct dst_entry *dst = __sk_dst_get(sk);
+
+	if (sysctl_tcp_nometrics_save)
+		return;
+
+	dst_confirm(dst);
+
+	if (dst && (dst->flags & DST_HOST)) {
+		const struct inet_connection_sock *icsk = inet_csk(sk);
+		int m;
+		unsigned long rtt;
+
+		if (icsk->icsk_backoff || !tp->srtt) {
+			/* This session failed to estimate rtt. Why?
+			 * Probably, no packets returned in time.
+			 * Reset our results.
+			 */
+			if (!(dst_metric_locked(dst, RTAX_RTT)))
+				dst->metrics[RTAX_RTT - 1] = 0;
+			return;
+		}
+
+		rtt = dst_metric_rtt(dst, RTAX_RTT);
+		m = rtt - tp->srtt;
+
+		/* If newly calculated rtt larger than stored one,
+		 * store new one. Otherwise, use EWMA. Remember,
+		 * rtt overestimation is always better than underestimation.
+		 */
+		if (!(dst_metric_locked(dst, RTAX_RTT))) {
+			if (m <= 0)
+				set_dst_metric_rtt(dst, RTAX_RTT, tp->srtt);
+			else
+				set_dst_metric_rtt(dst, RTAX_RTT, rtt - (m >> 3));
+		}
+
+		if (!(dst_metric_locked(dst, RTAX_RTTVAR))) {
+			unsigned long var;
+			if (m < 0)
+				m = -m;
+
+			/* Scale deviation to rttvar fixed point */
+			m >>= 1;
+			if (m < tp->mdev)
+				m = tp->mdev;
+
+			var = dst_metric_rtt(dst, RTAX_RTTVAR);
+			if (m >= var)
+				var = m;
+			else
+				var -= (var - m) >> 2;
+
+			set_dst_metric_rtt(dst, RTAX_RTTVAR, var);
+		}
+
+		if (tp->snd_ssthresh >= 0xFFFF) {
+			/* Slow start still did not finish. */
+			if (dst_metric(dst, RTAX_SSTHRESH) &&
+			    !dst_metric_locked(dst, RTAX_SSTHRESH) &&
+			    (tp->snd_cwnd >> 1) > dst_metric(dst, RTAX_SSTHRESH))
+				dst->metrics[RTAX_SSTHRESH-1] = tp->snd_cwnd >> 1;
+			if (!dst_metric_locked(dst, RTAX_CWND) &&
+			    tp->snd_cwnd > dst_metric(dst, RTAX_CWND))
+				dst->metrics[RTAX_CWND - 1] = tp->snd_cwnd;
+		} else if (tp->snd_cwnd > tp->snd_ssthresh &&
+			   icsk->icsk_ca_state == TCP_CA_Open) {
+			/* Cong. avoidance phase, cwnd is reliable. */
+			if (!dst_metric_locked(dst, RTAX_SSTHRESH))
+				dst->metrics[RTAX_SSTHRESH-1] =
+					max(tp->snd_cwnd >> 1, tp->snd_ssthresh);
+			if (!dst_metric_locked(dst, RTAX_CWND))
+				dst->metrics[RTAX_CWND-1] = (dst_metric(dst, RTAX_CWND) + tp->snd_cwnd) >> 1;
+		} else {
+			/* Else slow start did not finish, cwnd is non-sense,
+			   ssthresh may be also invalid.
+			 */
+			if (!dst_metric_locked(dst, RTAX_CWND))
+				dst->metrics[RTAX_CWND-1] = (dst_metric(dst, RTAX_CWND) + tp->snd_ssthresh) >> 1;
+			if (dst_metric(dst, RTAX_SSTHRESH) &&
+			    !dst_metric_locked(dst, RTAX_SSTHRESH) &&
+			    tp->snd_ssthresh > dst_metric(dst, RTAX_SSTHRESH))
+				dst->metrics[RTAX_SSTHRESH-1] = tp->snd_ssthresh;
+		}
+
+		if (!dst_metric_locked(dst, RTAX_REORDERING)) {
+			if (dst_metric(dst, RTAX_REORDERING) < tp->reordering &&
+			    tp->reordering != sysctl_tcp_reordering)
+				dst->metrics[RTAX_REORDERING-1] = tp->reordering;
+		}
+	}
+}
+
+/* Numbers are taken from RFC3390.
+ *
+ * John Heffner states:
+ *
+ *	The RFC specifies a window of no more than 4380 bytes
+ *	unless 2*MSS > 4380.  Reading the pseudocode in the RFC
+ *	is a bit misleading because they use a clamp at 4380 bytes
+ *	rather than use a multiplier in the relevant range.
+ */
+__u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst)
+{
+	__u32 cwnd = (dst ? dst_metric(dst, RTAX_INITCWND) : 0);
+
+	if (!cwnd) {
+		if (tp->mss_cache > 1460)
+			cwnd = 2;
+		else
+			cwnd = (tp->mss_cache > 1095) ? 3 : 4;
+	}
+	return min_t(__u32, cwnd, tp->snd_cwnd_clamp);
+}
+
+/* Set slow start threshold and cwnd not falling to slow start */
+void tcp_enter_cwr(struct sock *sk, const int set_ssthresh)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+
+	tp->prior_ssthresh = 0;
+	tp->bytes_acked = 0;
+	if (icsk->icsk_ca_state < TCP_CA_CWR) {
+		tp->undo_marker = 0;
+		if (set_ssthresh)
+			tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
+		tp->snd_cwnd = min(tp->snd_cwnd,
+				   tcp_packets_in_flight(tp) + 1U);
+		tp->snd_cwnd_cnt = 0;
+		tp->high_seq = tp->snd_nxt;
+		tp->snd_cwnd_stamp = tcp_time_stamp;
+		TCP_ECN_queue_cwr(tp);
+
+		tcp_set_ca_state(sk, TCP_CA_CWR);
+	}
+}
+
+/*
+ * Packet counting of FACK is based on in-order assumptions, therefore TCP
+ * disables it when reordering is detected
+ */
+static void tcp_disable_fack(struct tcp_sock *tp)
+{
+	/* RFC3517 uses different metric in lost marker => reset on change */
+	if (tcp_is_fack(tp))
+		tp->lost_skb_hint = NULL;
+	tp->rx_opt.sack_ok &= ~2;
+}
+
+/* Take a notice that peer is sending D-SACKs */
+static void tcp_dsack_seen(struct tcp_sock *tp)
+{
+	tp->rx_opt.sack_ok |= 4;
+}
+
+/* Initialize metrics on socket. */
+
+static void tcp_init_metrics(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct dst_entry *dst = __sk_dst_get(sk);
+
+	if (dst == NULL)
+		goto reset;
+
+	dst_confirm(dst);
+
+	if (dst_metric_locked(dst, RTAX_CWND))
+		tp->snd_cwnd_clamp = dst_metric(dst, RTAX_CWND);
+	if (dst_metric(dst, RTAX_SSTHRESH)) {
+		tp->snd_ssthresh = dst_metric(dst, RTAX_SSTHRESH);
+		if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
+			tp->snd_ssthresh = tp->snd_cwnd_clamp;
+	}
+	if (dst_metric(dst, RTAX_REORDERING) &&
+	    tp->reordering != dst_metric(dst, RTAX_REORDERING)) {
+		tcp_disable_fack(tp);
+		tp->reordering = dst_metric(dst, RTAX_REORDERING);
+	}
+
+	if (dst_metric(dst, RTAX_RTT) == 0)
+		goto reset;
+
+	if (!tp->srtt && dst_metric_rtt(dst, RTAX_RTT) < (TCP_TIMEOUT_INIT << 3))
+		goto reset;
+
+	/* Initial rtt is determined from SYN,SYN-ACK.
+	 * The segment is small and rtt may appear much
+	 * less than real one. Use per-dst memory
+	 * to make it more realistic.
+	 *
+	 * A bit of theory. RTT is time passed after "normal" sized packet
+	 * is sent until it is ACKed. In normal circumstances sending small
+	 * packets force peer to delay ACKs and calculation is correct too.
+	 * The algorithm is adaptive and, provided we follow specs, it
+	 * NEVER underestimate RTT. BUT! If peer tries to make some clever
+	 * tricks sort of "quick acks" for time long enough to decrease RTT
+	 * to low value, and then abruptly stops to do it and starts to delay
+	 * ACKs, wait for troubles.
+	 */
+	if (dst_metric_rtt(dst, RTAX_RTT) > tp->srtt) {
+		tp->srtt = dst_metric_rtt(dst, RTAX_RTT);
+		tp->rtt_seq = tp->snd_nxt;
+	}
+	if (dst_metric_rtt(dst, RTAX_RTTVAR) > tp->mdev) {
+		tp->mdev = dst_metric_rtt(dst, RTAX_RTTVAR);
+		tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
+	}
+	tcp_set_rto(sk);
+	tcp_bound_rto(sk);
+	if (inet_csk(sk)->icsk_rto < TCP_TIMEOUT_INIT && !tp->rx_opt.saw_tstamp)
+		goto reset;
+	tp->snd_cwnd = tcp_init_cwnd(tp, dst);
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+	return;
+
+reset:
+	/* Play conservative. If timestamps are not
+	 * supported, TCP will fail to recalculate correct
+	 * rtt, if initial rto is too small. FORGET ALL AND RESET!
+	 */
+	if (!tp->rx_opt.saw_tstamp && tp->srtt) {
+		tp->srtt = 0;
+		tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_INIT;
+		inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+	}
+}
+
+static void tcp_update_reordering(struct sock *sk, const int metric,
+				  const int ts)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	if (metric > tp->reordering) {
+		int mib_idx;
+
+		tp->reordering = min(TCP_MAX_REORDERING, metric);
+
+		/* This exciting event is worth to be remembered. 8) */
+		if (ts)
+			mib_idx = LINUX_MIB_TCPTSREORDER;
+		else if (tcp_is_reno(tp))
+			mib_idx = LINUX_MIB_TCPRENOREORDER;
+		else if (tcp_is_fack(tp))
+			mib_idx = LINUX_MIB_TCPFACKREORDER;
+		else
+			mib_idx = LINUX_MIB_TCPSACKREORDER;
+
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+#if FASTRETRANS_DEBUG > 1
+		printk(KERN_DEBUG "Disorder%d %d %u f%u s%u rr%d\n",
+		       tp->rx_opt.sack_ok, inet_csk(sk)->icsk_ca_state,
+		       tp->reordering,
+		       tp->fackets_out,
+		       tp->sacked_out,
+		       tp->undo_marker ? tp->undo_retrans : 0);
+#endif
+		tcp_disable_fack(tp);
+	}
+}
+
+/* This must be called before lost_out is incremented */
+static void tcp_verify_retransmit_hint(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	if ((tp->retransmit_skb_hint == NULL) ||
+	    before(TCP_SKB_CB(skb)->seq,
+		   TCP_SKB_CB(tp->retransmit_skb_hint)->seq))
+		tp->retransmit_skb_hint = skb;
+
+	if (!tp->lost_out ||
+	    after(TCP_SKB_CB(skb)->end_seq, tp->retransmit_high))
+		tp->retransmit_high = TCP_SKB_CB(skb)->end_seq;
+}
+
+static void tcp_skb_mark_lost(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) {
+		tcp_verify_retransmit_hint(tp, skb);
+
+		tp->lost_out += tcp_skb_pcount(skb);
+		TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+	}
+}
+
+void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	tcp_verify_retransmit_hint(tp, skb);
+
+	if (!(TCP_SKB_CB(skb)->sacked & (TCPCB_LOST|TCPCB_SACKED_ACKED))) {
+		tp->lost_out += tcp_skb_pcount(skb);
+		TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+	}
+}
+
+/* This procedure tags the retransmission queue when SACKs arrive.
+ *
+ * We have three tag bits: SACKED(S), RETRANS(R) and LOST(L).
+ * Packets in queue with these bits set are counted in variables
+ * sacked_out, retrans_out and lost_out, correspondingly.
+ *
+ * Valid combinations are:
+ * Tag  InFlight	Description
+ * 0	1		- orig segment is in flight.
+ * S	0		- nothing flies, orig reached receiver.
+ * L	0		- nothing flies, orig lost by net.
+ * R	2		- both orig and retransmit are in flight.
+ * L|R	1		- orig is lost, retransmit is in flight.
+ * S|R  1		- orig reached receiver, retrans is still in flight.
+ * (L|S|R is logically valid, it could occur when L|R is sacked,
+ *  but it is equivalent to plain S and code short-curcuits it to S.
+ *  L|S is logically invalid, it would mean -1 packet in flight 8))
+ *
+ * These 6 states form finite state machine, controlled by the following events:
+ * 1. New ACK (+SACK) arrives. (tcp_sacktag_write_queue())
+ * 2. Retransmission. (tcp_retransmit_skb(), tcp_xmit_retransmit_queue())
+ * 3. Loss detection event of one of three flavors:
+ *	A. Scoreboard estimator decided the packet is lost.
+ *	   A'. Reno "three dupacks" marks head of queue lost.
+ *	   A''. Its FACK modfication, head until snd.fack is lost.
+ *	B. SACK arrives sacking data transmitted after never retransmitted
+ *	   hole was sent out.
+ *	C. SACK arrives sacking SND.NXT at the moment, when the
+ *	   segment was retransmitted.
+ * 4. D-SACK added new rule: D-SACK changes any tag to S.
+ *
+ * It is pleasant to note, that state diagram turns out to be commutative,
+ * so that we are allowed not to be bothered by order of our actions,
+ * when multiple events arrive simultaneously. (see the function below).
+ *
+ * Reordering detection.
+ * --------------------
+ * Reordering metric is maximal distance, which a packet can be displaced
+ * in packet stream. With SACKs we can estimate it:
+ *
+ * 1. SACK fills old hole and the corresponding segment was not
+ *    ever retransmitted -> reordering. Alas, we cannot use it
+ *    when segment was retransmitted.
+ * 2. The last flaw is solved with D-SACK. D-SACK arrives
+ *    for retransmitted and already SACKed segment -> reordering..
+ * Both of these heuristics are not used in Loss state, when we cannot
+ * account for retransmits accurately.
+ *
+ * SACK block validation.
+ * ----------------------
+ *
+ * SACK block range validation checks that the received SACK block fits to
+ * the expected sequence limits, i.e., it is between SND.UNA and SND.NXT.
+ * Note that SND.UNA is not included to the range though being valid because
+ * it means that the receiver is rather inconsistent with itself reporting
+ * SACK reneging when it should advance SND.UNA. Such SACK block this is
+ * perfectly valid, however, in light of RFC2018 which explicitly states
+ * that "SACK block MUST reflect the newest segment.  Even if the newest
+ * segment is going to be discarded ...", not that it looks very clever
+ * in case of head skb. Due to potentional receiver driven attacks, we
+ * choose to avoid immediate execution of a walk in write queue due to
+ * reneging and defer head skb's loss recovery to standard loss recovery
+ * procedure that will eventually trigger (nothing forbids us doing this).
+ *
+ * Implements also blockage to start_seq wrap-around. Problem lies in the
+ * fact that though start_seq (s) is before end_seq (i.e., not reversed),
+ * there's no guarantee that it will be before snd_nxt (n). The problem
+ * happens when start_seq resides between end_seq wrap (e_w) and snd_nxt
+ * wrap (s_w):
+ *
+ *         <- outs wnd ->                          <- wrapzone ->
+ *         u     e      n                         u_w   e_w  s n_w
+ *         |     |      |                          |     |   |  |
+ * |<------------+------+----- TCP seqno space --------------+---------->|
+ * ...-- <2^31 ->|                                           |<--------...
+ * ...---- >2^31 ------>|                                    |<--------...
+ *
+ * Current code wouldn't be vulnerable but it's better still to discard such
+ * crazy SACK blocks. Doing this check for start_seq alone closes somewhat
+ * similar case (end_seq after snd_nxt wrap) as earlier reversed check in
+ * snd_nxt wrap -> snd_una region will then become "well defined", i.e.,
+ * equal to the ideal case (infinite seqno space without wrap caused issues).
+ *
+ * With D-SACK the lower bound is extended to cover sequence space below
+ * SND.UNA down to undo_marker, which is the last point of interest. Yet
+ * again, D-SACK block must not to go across snd_una (for the same reason as
+ * for the normal SACK blocks, explained above). But there all simplicity
+ * ends, TCP might receive valid D-SACKs below that. As long as they reside
+ * fully below undo_marker they do not affect behavior in anyway and can
+ * therefore be safely ignored. In rare cases (which are more or less
+ * theoretical ones), the D-SACK will nicely cross that boundary due to skb
+ * fragmentation and packet reordering past skb's retransmission. To consider
+ * them correctly, the acceptable range must be extended even more though
+ * the exact amount is rather hard to quantify. However, tp->max_window can
+ * be used as an exaggerated estimate.
+ */
+static int tcp_is_sackblock_valid(struct tcp_sock *tp, int is_dsack,
+				  u32 start_seq, u32 end_seq)
+{
+	/* Too far in future, or reversed (interpretation is ambiguous) */
+	if (after(end_seq, tp->snd_nxt) || !before(start_seq, end_seq))
+		return 0;
+
+	/* Nasty start_seq wrap-around check (see comments above) */
+	if (!before(start_seq, tp->snd_nxt))
+		return 0;
+
+	/* In outstanding window? ...This is valid exit for D-SACKs too.
+	 * start_seq == snd_una is non-sensical (see comments above)
+	 */
+	if (after(start_seq, tp->snd_una))
+		return 1;
+
+	if (!is_dsack || !tp->undo_marker)
+		return 0;
+
+	/* ...Then it's D-SACK, and must reside below snd_una completely */
+	if (!after(end_seq, tp->snd_una))
+		return 0;
+
+	if (!before(start_seq, tp->undo_marker))
+		return 1;
+
+	/* Too old */
+	if (!after(end_seq, tp->undo_marker))
+		return 0;
+
+	/* Undo_marker boundary crossing (overestimates a lot). Known already:
+	 *   start_seq < undo_marker and end_seq >= undo_marker.
+	 */
+	return !before(start_seq, end_seq - tp->max_window);
+}
+
+/* Check for lost retransmit. This superb idea is borrowed from "ratehalving".
+ * Event "C". Later note: FACK people cheated me again 8), we have to account
+ * for reordering! Ugly, but should help.
+ *
+ * Search retransmitted skbs from write_queue that were sent when snd_nxt was
+ * less than what is now known to be received by the other end (derived from
+ * highest SACK block). Also calculate the lowest snd_nxt among the remaining
+ * retransmitted skbs to avoid some costly processing per ACKs.
+ */
+static void tcp_mark_lost_retrans(struct sock *sk)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	int cnt = 0;
+	u32 new_low_seq = tp->snd_nxt;
+	u32 received_upto = tcp_highest_sack_seq(tp);
+
+	if (!tcp_is_fack(tp) || !tp->retrans_out ||
+	    !after(received_upto, tp->lost_retrans_low) ||
+	    icsk->icsk_ca_state != TCP_CA_Recovery)
+		return;
+
+	tcp_for_write_queue(skb, sk) {
+		u32 ack_seq = TCP_SKB_CB(skb)->ack_seq;
+
+		if (skb == tcp_send_head(sk))
+			break;
+		if (cnt == tp->retrans_out)
+			break;
+		if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
+			continue;
+
+		if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS))
+			continue;
+
+		if (after(received_upto, ack_seq) &&
+		    (tcp_is_fack(tp) ||
+		     !before(received_upto,
+			     ack_seq + tp->reordering * tp->mss_cache))) {
+			TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
+			tp->retrans_out -= tcp_skb_pcount(skb);
+
+			tcp_skb_mark_lost_uncond_verify(tp, skb);
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSTRETRANSMIT);
+		} else {
+			if (before(ack_seq, new_low_seq))
+				new_low_seq = ack_seq;
+			cnt += tcp_skb_pcount(skb);
+		}
+	}
+
+	if (tp->retrans_out)
+		tp->lost_retrans_low = new_low_seq;
+}
+
+static int tcp_check_dsack(struct sock *sk, struct sk_buff *ack_skb,
+			   struct tcp_sack_block_wire *sp, int num_sacks,
+			   u32 prior_snd_una)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 start_seq_0 = get_unaligned_be32(&sp[0].start_seq);
+	u32 end_seq_0 = get_unaligned_be32(&sp[0].end_seq);
+	int dup_sack = 0;
+
+	if (before(start_seq_0, TCP_SKB_CB(ack_skb)->ack_seq)) {
+		dup_sack = 1;
+		tcp_dsack_seen(tp);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPDSACKRECV);
+	} else if (num_sacks > 1) {
+		u32 end_seq_1 = get_unaligned_be32(&sp[1].end_seq);
+		u32 start_seq_1 = get_unaligned_be32(&sp[1].start_seq);
+
+		if (!after(end_seq_0, end_seq_1) &&
+		    !before(start_seq_0, start_seq_1)) {
+			dup_sack = 1;
+			tcp_dsack_seen(tp);
+			NET_INC_STATS_BH(sock_net(sk),
+					LINUX_MIB_TCPDSACKOFORECV);
+		}
+	}
+
+	/* D-SACK for already forgotten data... Do dumb counting. */
+	if (dup_sack &&
+	    !after(end_seq_0, prior_snd_una) &&
+	    after(end_seq_0, tp->undo_marker))
+		tp->undo_retrans--;
+
+	return dup_sack;
+}
+
+/* Check if skb is fully within the SACK block. In presence of GSO skbs,
+ * the incoming SACK may not exactly match but we can find smaller MSS
+ * aligned portion of it that matches. Therefore we might need to fragment
+ * which may fail and creates some hassle (caller must handle error case
+ * returns).
+ */
+static int tcp_match_skb_to_sack(struct sock *sk, struct sk_buff *skb,
+				 u32 start_seq, u32 end_seq)
+{
+	int in_sack, err;
+	unsigned int pkt_len;
+
+	in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq) &&
+		  !before(end_seq, TCP_SKB_CB(skb)->end_seq);
+
+	if (tcp_skb_pcount(skb) > 1 && !in_sack &&
+	    after(TCP_SKB_CB(skb)->end_seq, start_seq)) {
+
+		in_sack = !after(start_seq, TCP_SKB_CB(skb)->seq);
+
+		if (!in_sack)
+			pkt_len = start_seq - TCP_SKB_CB(skb)->seq;
+		else
+			pkt_len = end_seq - TCP_SKB_CB(skb)->seq;
+		err = tcp_fragment(sk, skb, pkt_len, skb_shinfo(skb)->gso_size);
+		if (err < 0)
+			return err;
+	}
+
+	return in_sack;
+}
+
+static int tcp_sacktag_one(struct sk_buff *skb, struct sock *sk,
+			   int *reord, int dup_sack, int fack_count)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u8 sacked = TCP_SKB_CB(skb)->sacked;
+	int flag = 0;
+
+	/* Account D-SACK for retransmitted packet. */
+	if (dup_sack && (sacked & TCPCB_RETRANS)) {
+		if (after(TCP_SKB_CB(skb)->end_seq, tp->undo_marker))
+			tp->undo_retrans--;
+		if (sacked & TCPCB_SACKED_ACKED)
+			*reord = min(fack_count, *reord);
+	}
+
+	/* Nothing to do; acked frame is about to be dropped (was ACKed). */
+	if (!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
+		return flag;
+
+	if (!(sacked & TCPCB_SACKED_ACKED)) {
+		if (sacked & TCPCB_SACKED_RETRANS) {
+			/* If the segment is not tagged as lost,
+			 * we do not clear RETRANS, believing
+			 * that retransmission is still in flight.
+			 */
+			if (sacked & TCPCB_LOST) {
+				TCP_SKB_CB(skb)->sacked &=
+					~(TCPCB_LOST|TCPCB_SACKED_RETRANS);
+				tp->lost_out -= tcp_skb_pcount(skb);
+				tp->retrans_out -= tcp_skb_pcount(skb);
+			}
+		} else {
+			if (!(sacked & TCPCB_RETRANS)) {
+				/* New sack for not retransmitted frame,
+				 * which was in hole. It is reordering.
+				 */
+				if (before(TCP_SKB_CB(skb)->seq,
+					   tcp_highest_sack_seq(tp)))
+					*reord = min(fack_count, *reord);
+
+				/* SACK enhanced F-RTO (RFC4138; Appendix B) */
+				if (!after(TCP_SKB_CB(skb)->end_seq, tp->frto_highmark))
+					flag |= FLAG_ONLY_ORIG_SACKED;
+			}
+
+			if (sacked & TCPCB_LOST) {
+				TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
+				tp->lost_out -= tcp_skb_pcount(skb);
+			}
+		}
+
+		TCP_SKB_CB(skb)->sacked |= TCPCB_SACKED_ACKED;
+		flag |= FLAG_DATA_SACKED;
+		tp->sacked_out += tcp_skb_pcount(skb);
+
+		fack_count += tcp_skb_pcount(skb);
+
+		/* Lost marker hint past SACKed? Tweak RFC3517 cnt */
+		if (!tcp_is_fack(tp) && (tp->lost_skb_hint != NULL) &&
+		    before(TCP_SKB_CB(skb)->seq,
+			   TCP_SKB_CB(tp->lost_skb_hint)->seq))
+			tp->lost_cnt_hint += tcp_skb_pcount(skb);
+
+		if (fack_count > tp->fackets_out)
+			tp->fackets_out = fack_count;
+
+		if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+			tcp_advance_highest_sack(sk, skb);
+	}
+
+	/* D-SACK. We can detect redundant retransmission in S|R and plain R
+	 * frames and clear it. undo_retrans is decreased above, L|R frames
+	 * are accounted above as well.
+	 */
+	if (dup_sack && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)) {
+		TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
+		tp->retrans_out -= tcp_skb_pcount(skb);
+	}
+
+	return flag;
+}
+
+static struct sk_buff *tcp_sacktag_walk(struct sk_buff *skb, struct sock *sk,
+					struct tcp_sack_block *next_dup,
+					u32 start_seq, u32 end_seq,
+					int dup_sack_in, int *fack_count,
+					int *reord, int *flag)
+{
+	tcp_for_write_queue_from(skb, sk) {
+		int in_sack = 0;
+		int dup_sack = dup_sack_in;
+
+		if (skb == tcp_send_head(sk))
+			break;
+
+		/* queue is in-order => we can short-circuit the walk early */
+		if (!before(TCP_SKB_CB(skb)->seq, end_seq))
+			break;
+
+		if ((next_dup != NULL) &&
+		    before(TCP_SKB_CB(skb)->seq, next_dup->end_seq)) {
+			in_sack = tcp_match_skb_to_sack(sk, skb,
+							next_dup->start_seq,
+							next_dup->end_seq);
+			if (in_sack > 0)
+				dup_sack = 1;
+		}
+
+		if (in_sack <= 0)
+			in_sack = tcp_match_skb_to_sack(sk, skb, start_seq,
+							end_seq);
+		if (unlikely(in_sack < 0))
+			break;
+
+		if (in_sack)
+			*flag |= tcp_sacktag_one(skb, sk, reord, dup_sack,
+						 *fack_count);
+
+		*fack_count += tcp_skb_pcount(skb);
+	}
+	return skb;
+}
+
+/* Avoid all extra work that is being done by sacktag while walking in
+ * a normal way
+ */
+static struct sk_buff *tcp_sacktag_skip(struct sk_buff *skb, struct sock *sk,
+					u32 skip_to_seq, int *fack_count)
+{
+	tcp_for_write_queue_from(skb, sk) {
+		if (skb == tcp_send_head(sk))
+			break;
+
+		if (!before(TCP_SKB_CB(skb)->end_seq, skip_to_seq))
+			break;
+
+		*fack_count += tcp_skb_pcount(skb);
+	}
+	return skb;
+}
+
+static struct sk_buff *tcp_maybe_skipping_dsack(struct sk_buff *skb,
+						struct sock *sk,
+						struct tcp_sack_block *next_dup,
+						u32 skip_to_seq,
+						int *fack_count, int *reord,
+						int *flag)
+{
+	if (next_dup == NULL)
+		return skb;
+
+	if (before(next_dup->start_seq, skip_to_seq)) {
+		skb = tcp_sacktag_skip(skb, sk, next_dup->start_seq, fack_count);
+		skb = tcp_sacktag_walk(skb, sk, NULL,
+				     next_dup->start_seq, next_dup->end_seq,
+				     1, fack_count, reord, flag);
+	}
+
+	return skb;
+}
+
+static int tcp_sack_cache_ok(struct tcp_sock *tp, struct tcp_sack_block *cache)
+{
+	return cache < tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache);
+}
+
+static int
+tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb,
+			u32 prior_snd_una)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned char *ptr = (skb_transport_header(ack_skb) +
+			      TCP_SKB_CB(ack_skb)->sacked);
+	struct tcp_sack_block_wire *sp_wire = (struct tcp_sack_block_wire *)(ptr+2);
+	struct tcp_sack_block sp[TCP_NUM_SACKS];
+	struct tcp_sack_block *cache;
+	struct sk_buff *skb;
+	int num_sacks = min(TCP_NUM_SACKS, (ptr[1] - TCPOLEN_SACK_BASE) >> 3);
+	int used_sacks;
+	int reord = tp->packets_out;
+	int flag = 0;
+	int found_dup_sack = 0;
+	int fack_count;
+	int i, j;
+	int first_sack_index;
+
+	if (!tp->sacked_out) {
+		if (WARN_ON(tp->fackets_out))
+			tp->fackets_out = 0;
+		tcp_highest_sack_reset(sk);
+	}
+
+	found_dup_sack = tcp_check_dsack(sk, ack_skb, sp_wire,
+					 num_sacks, prior_snd_una);
+	if (found_dup_sack)
+		flag |= FLAG_DSACKING_ACK;
+
+	/* Eliminate too old ACKs, but take into
+	 * account more or less fresh ones, they can
+	 * contain valid SACK info.
+	 */
+	if (before(TCP_SKB_CB(ack_skb)->ack_seq, prior_snd_una - tp->max_window))
+		return 0;
+
+	if (!tp->packets_out)
+		goto out;
+
+	used_sacks = 0;
+	first_sack_index = 0;
+	for (i = 0; i < num_sacks; i++) {
+		int dup_sack = !i && found_dup_sack;
+
+		sp[used_sacks].start_seq = get_unaligned_be32(&sp_wire[i].start_seq);
+		sp[used_sacks].end_seq = get_unaligned_be32(&sp_wire[i].end_seq);
+
+		if (!tcp_is_sackblock_valid(tp, dup_sack,
+					    sp[used_sacks].start_seq,
+					    sp[used_sacks].end_seq)) {
+			int mib_idx;
+
+			if (dup_sack) {
+				if (!tp->undo_marker)
+					mib_idx = LINUX_MIB_TCPDSACKIGNOREDNOUNDO;
+				else
+					mib_idx = LINUX_MIB_TCPDSACKIGNOREDOLD;
+			} else {
+				/* Don't count olds caused by ACK reordering */
+				if ((TCP_SKB_CB(ack_skb)->ack_seq != tp->snd_una) &&
+				    !after(sp[used_sacks].end_seq, tp->snd_una))
+					continue;
+				mib_idx = LINUX_MIB_TCPSACKDISCARD;
+			}
+
+			NET_INC_STATS_BH(sock_net(sk), mib_idx);
+			if (i == 0)
+				first_sack_index = -1;
+			continue;
+		}
+
+		/* Ignore very old stuff early */
+		if (!after(sp[used_sacks].end_seq, prior_snd_una))
+			continue;
+
+		used_sacks++;
+	}
+
+	/* order SACK blocks to allow in order walk of the retrans queue */
+	for (i = used_sacks - 1; i > 0; i--) {
+		for (j = 0; j < i; j++) {
+			if (after(sp[j].start_seq, sp[j + 1].start_seq)) {
+				struct tcp_sack_block tmp;
+
+				tmp = sp[j];
+				sp[j] = sp[j + 1];
+				sp[j + 1] = tmp;
+
+				/* Track where the first SACK block goes to */
+				if (j == first_sack_index)
+					first_sack_index = j + 1;
+			}
+		}
+	}
+
+	skb = tcp_write_queue_head(sk);
+	fack_count = 0;
+	i = 0;
+
+	if (!tp->sacked_out) {
+		/* It's already past, so skip checking against it */
+		cache = tp->recv_sack_cache + ARRAY_SIZE(tp->recv_sack_cache);
+	} else {
+		cache = tp->recv_sack_cache;
+		/* Skip empty blocks in at head of the cache */
+		while (tcp_sack_cache_ok(tp, cache) && !cache->start_seq &&
+		       !cache->end_seq)
+			cache++;
+	}
+
+	while (i < used_sacks) {
+		u32 start_seq = sp[i].start_seq;
+		u32 end_seq = sp[i].end_seq;
+		int dup_sack = (found_dup_sack && (i == first_sack_index));
+		struct tcp_sack_block *next_dup = NULL;
+
+		if (found_dup_sack && ((i + 1) == first_sack_index))
+			next_dup = &sp[i + 1];
+
+		/* Event "B" in the comment above. */
+		if (after(end_seq, tp->high_seq))
+			flag |= FLAG_DATA_LOST;
+
+		/* Skip too early cached blocks */
+		while (tcp_sack_cache_ok(tp, cache) &&
+		       !before(start_seq, cache->end_seq))
+			cache++;
+
+		/* Can skip some work by looking recv_sack_cache? */
+		if (tcp_sack_cache_ok(tp, cache) && !dup_sack &&
+		    after(end_seq, cache->start_seq)) {
+
+			/* Head todo? */
+			if (before(start_seq, cache->start_seq)) {
+				skb = tcp_sacktag_skip(skb, sk, start_seq,
+						       &fack_count);
+				skb = tcp_sacktag_walk(skb, sk, next_dup,
+						       start_seq,
+						       cache->start_seq,
+						       dup_sack, &fack_count,
+						       &reord, &flag);
+			}
+
+			/* Rest of the block already fully processed? */
+			if (!after(end_seq, cache->end_seq))
+				goto advance_sp;
+
+			skb = tcp_maybe_skipping_dsack(skb, sk, next_dup,
+						       cache->end_seq,
+						       &fack_count, &reord,
+						       &flag);
+
+			/* ...tail remains todo... */
+			if (tcp_highest_sack_seq(tp) == cache->end_seq) {
+				/* ...but better entrypoint exists! */
+				skb = tcp_highest_sack(sk);
+				if (skb == NULL)
+					break;
+				fack_count = tp->fackets_out;
+				cache++;
+				goto walk;
+			}
+
+			skb = tcp_sacktag_skip(skb, sk, cache->end_seq,
+					       &fack_count);
+			/* Check overlap against next cached too (past this one already) */
+			cache++;
+			continue;
+		}
+
+		if (!before(start_seq, tcp_highest_sack_seq(tp))) {
+			skb = tcp_highest_sack(sk);
+			if (skb == NULL)
+				break;
+			fack_count = tp->fackets_out;
+		}
+		skb = tcp_sacktag_skip(skb, sk, start_seq, &fack_count);
+
+walk:
+		skb = tcp_sacktag_walk(skb, sk, next_dup, start_seq, end_seq,
+				       dup_sack, &fack_count, &reord, &flag);
+
+advance_sp:
+		/* SACK enhanced FRTO (RFC4138, Appendix B): Clearing correct
+		 * due to in-order walk
+		 */
+		if (after(end_seq, tp->frto_highmark))
+			flag &= ~FLAG_ONLY_ORIG_SACKED;
+
+		i++;
+	}
+
+	/* Clear the head of the cache sack blocks so we can skip it next time */
+	for (i = 0; i < ARRAY_SIZE(tp->recv_sack_cache) - used_sacks; i++) {
+		tp->recv_sack_cache[i].start_seq = 0;
+		tp->recv_sack_cache[i].end_seq = 0;
+	}
+	for (j = 0; j < used_sacks; j++)
+		tp->recv_sack_cache[i++] = sp[j];
+
+	tcp_mark_lost_retrans(sk);
+
+	tcp_verify_left_out(tp);
+
+	if ((reord < tp->fackets_out) &&
+	    ((icsk->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker) &&
+	    (!tp->frto_highmark || after(tp->snd_una, tp->frto_highmark)))
+		tcp_update_reordering(sk, tp->fackets_out - reord, 0);
+
+out:
+
+#if FASTRETRANS_DEBUG > 0
+	WARN_ON((int)tp->sacked_out < 0);
+	WARN_ON((int)tp->lost_out < 0);
+	WARN_ON((int)tp->retrans_out < 0);
+	WARN_ON((int)tcp_packets_in_flight(tp) < 0);
+#endif
+	return flag;
+}
+
+/* Limits sacked_out so that sum with lost_out isn't ever larger than
+ * packets_out. Returns zero if sacked_out adjustement wasn't necessary.
+ */
+int tcp_limit_reno_sacked(struct tcp_sock *tp)
+{
+	u32 holes;
+
+	holes = max(tp->lost_out, 1U);
+	holes = min(holes, tp->packets_out);
+
+	if ((tp->sacked_out + holes) > tp->packets_out) {
+		tp->sacked_out = tp->packets_out - holes;
+		return 1;
+	}
+	return 0;
+}
+
+/* If we receive more dupacks than we expected counting segments
+ * in assumption of absent reordering, interpret this as reordering.
+ * The only another reason could be bug in receiver TCP.
+ */
+static void tcp_check_reno_reordering(struct sock *sk, const int addend)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	if (tcp_limit_reno_sacked(tp))
+		tcp_update_reordering(sk, tp->packets_out + addend, 0);
+}
+
+/* Emulate SACKs for SACKless connection: account for a new dupack. */
+
+static void tcp_add_reno_sack(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	tp->sacked_out++;
+	tcp_check_reno_reordering(sk, 0);
+	tcp_verify_left_out(tp);
+}
+
+/* Account for ACK, ACKing some data in Reno Recovery phase. */
+
+static void tcp_remove_reno_sacks(struct sock *sk, int acked)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (acked > 0) {
+		/* One ACK acked hole. The rest eat duplicate ACKs. */
+		if (acked - 1 >= tp->sacked_out)
+			tp->sacked_out = 0;
+		else
+			tp->sacked_out -= acked - 1;
+	}
+	tcp_check_reno_reordering(sk, acked);
+	tcp_verify_left_out(tp);
+}
+
+static inline void tcp_reset_reno_sack(struct tcp_sock *tp)
+{
+	tp->sacked_out = 0;
+}
+
+static int tcp_is_sackfrto(const struct tcp_sock *tp)
+{
+	return (sysctl_tcp_frto == 0x2) && !tcp_is_reno(tp);
+}
+
+/* F-RTO can only be used if TCP has never retransmitted anything other than
+ * head (SACK enhanced variant from Appendix B of RFC4138 is more robust here)
+ */
+int tcp_use_frto(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct sk_buff *skb;
+
+	if (!sysctl_tcp_frto)
+		return 0;
+
+	/* MTU probe and F-RTO won't really play nicely along currently */
+	if (icsk->icsk_mtup.probe_size)
+		return 0;
+
+	if (tcp_is_sackfrto(tp))
+		return 1;
+
+	/* Avoid expensive walking of rexmit queue if possible */
+	if (tp->retrans_out > 1)
+		return 0;
+
+	skb = tcp_write_queue_head(sk);
+	if (tcp_skb_is_last(sk, skb))
+		return 1;
+	skb = tcp_write_queue_next(sk, skb);	/* Skips head */
+	tcp_for_write_queue_from(skb, sk) {
+		if (skb == tcp_send_head(sk))
+			break;
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS)
+			return 0;
+		/* Short-circuit when first non-SACKed skb has been checked */
+		if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
+			break;
+	}
+	return 1;
+}
+
+/* RTO occurred, but do not yet enter Loss state. Instead, defer RTO
+ * recovery a bit and use heuristics in tcp_process_frto() to detect if
+ * the RTO was spurious. Only clear SACKED_RETRANS of the head here to
+ * keep retrans_out counting accurate (with SACK F-RTO, other than head
+ * may still have that bit set); TCPCB_LOST and remaining SACKED_RETRANS
+ * bits are handled if the Loss state is really to be entered (in
+ * tcp_enter_frto_loss).
+ *
+ * Do like tcp_enter_loss() would; when RTO expires the second time it
+ * does:
+ *  "Reduce ssthresh if it has not yet been made inside this window."
+ */
+void tcp_enter_frto(struct sock *sk)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	if ((!tp->frto_counter && icsk->icsk_ca_state <= TCP_CA_Disorder) ||
+	    tp->snd_una == tp->high_seq ||
+	    ((icsk->icsk_ca_state == TCP_CA_Loss || tp->frto_counter) &&
+	     !icsk->icsk_retransmits)) {
+		tp->prior_ssthresh = tcp_current_ssthresh(sk);
+		/* Our state is too optimistic in ssthresh() call because cwnd
+		 * is not reduced until tcp_enter_frto_loss() when previous F-RTO
+		 * recovery has not yet completed. Pattern would be this: RTO,
+		 * Cumulative ACK, RTO (2xRTO for the same segment does not end
+		 * up here twice).
+		 * RFC4138 should be more specific on what to do, even though
+		 * RTO is quite unlikely to occur after the first Cumulative ACK
+		 * due to back-off and complexity of triggering events ...
+		 */
+		if (tp->frto_counter) {
+			u32 stored_cwnd;
+			stored_cwnd = tp->snd_cwnd;
+			tp->snd_cwnd = 2;
+			tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
+			tp->snd_cwnd = stored_cwnd;
+		} else {
+			tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
+		}
+		/* ... in theory, cong.control module could do "any tricks" in
+		 * ssthresh(), which means that ca_state, lost bits and lost_out
+		 * counter would have to be faked before the call occurs. We
+		 * consider that too expensive, unlikely and hacky, so modules
+		 * using these in ssthresh() must deal these incompatibility
+		 * issues if they receives CA_EVENT_FRTO and frto_counter != 0
+		 */
+		tcp_ca_event(sk, CA_EVENT_FRTO);
+	}
+
+	tp->undo_marker = tp->snd_una;
+	tp->undo_retrans = 0;
+
+	skb = tcp_write_queue_head(sk);
+	if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS)
+		tp->undo_marker = 0;
+	if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
+		TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
+		tp->retrans_out -= tcp_skb_pcount(skb);
+	}
+	tcp_verify_left_out(tp);
+
+	/* Too bad if TCP was application limited */
+	tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp) + 1);
+
+	/* Earlier loss recovery underway (see RFC4138; Appendix B).
+	 * The last condition is necessary at least in tp->frto_counter case.
+	 */
+	if (tcp_is_sackfrto(tp) && (tp->frto_counter ||
+	    ((1 << icsk->icsk_ca_state) & (TCPF_CA_Recovery|TCPF_CA_Loss))) &&
+	    after(tp->high_seq, tp->snd_una)) {
+		tp->frto_highmark = tp->high_seq;
+	} else {
+		tp->frto_highmark = tp->snd_nxt;
+	}
+	tcp_set_ca_state(sk, TCP_CA_Disorder);
+	tp->high_seq = tp->snd_nxt;
+	tp->frto_counter = 1;
+}
+
+/* Enter Loss state after F-RTO was applied. Dupack arrived after RTO,
+ * which indicates that we should follow the traditional RTO recovery,
+ * i.e. mark everything lost and do go-back-N retransmission.
+ */
+static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	tp->lost_out = 0;
+	tp->retrans_out = 0;
+	if (tcp_is_reno(tp))
+		tcp_reset_reno_sack(tp);
+
+	tcp_for_write_queue(skb, sk) {
+		if (skb == tcp_send_head(sk))
+			break;
+
+		TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
+		/*
+		 * Count the retransmission made on RTO correctly (only when
+		 * waiting for the first ACK and did not get it)...
+		 */
+		if ((tp->frto_counter == 1) && !(flag & FLAG_DATA_ACKED)) {
+			/* For some reason this R-bit might get cleared? */
+			if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
+				tp->retrans_out += tcp_skb_pcount(skb);
+			/* ...enter this if branch just for the first segment */
+			flag |= FLAG_DATA_ACKED;
+		} else {
+			if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS)
+				tp->undo_marker = 0;
+			TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
+		}
+
+		/* Marking forward transmissions that were made after RTO lost
+		 * can cause unnecessary retransmissions in some scenarios,
+		 * SACK blocks will mitigate that in some but not in all cases.
+		 * We used to not mark them but it was causing break-ups with
+		 * receivers that do only in-order receival.
+		 *
+		 * TODO: we could detect presence of such receiver and select
+		 * different behavior per flow.
+		 */
+		if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) {
+			TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+			tp->lost_out += tcp_skb_pcount(skb);
+			tp->retransmit_high = TCP_SKB_CB(skb)->end_seq;
+		}
+	}
+	tcp_verify_left_out(tp);
+
+	tp->snd_cwnd = tcp_packets_in_flight(tp) + allowed_segments;
+	tp->snd_cwnd_cnt = 0;
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+	tp->frto_counter = 0;
+	tp->bytes_acked = 0;
+
+	tp->reordering = min_t(unsigned int, tp->reordering,
+			       sysctl_tcp_reordering);
+	tcp_set_ca_state(sk, TCP_CA_Loss);
+	tp->high_seq = tp->snd_nxt;
+	TCP_ECN_queue_cwr(tp);
+
+	tcp_clear_all_retrans_hints(tp);
+}
+
+static void tcp_clear_retrans_partial(struct tcp_sock *tp)
+{
+	tp->retrans_out = 0;
+	tp->lost_out = 0;
+
+	tp->undo_marker = 0;
+	tp->undo_retrans = 0;
+}
+
+void tcp_clear_retrans(struct tcp_sock *tp)
+{
+	tcp_clear_retrans_partial(tp);
+
+	tp->fackets_out = 0;
+	tp->sacked_out = 0;
+}
+
+/* Enter Loss state. If "how" is not zero, forget all SACK information
+ * and reset tags completely, otherwise preserve SACKs. If receiver
+ * dropped its ofo queue, we will know this due to reneging detection.
+ */
+void tcp_enter_loss(struct sock *sk, int how)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	/* Reduce ssthresh if it has not yet been made inside this window. */
+	if (icsk->icsk_ca_state <= TCP_CA_Disorder || tp->snd_una == tp->high_seq ||
+	    (icsk->icsk_ca_state == TCP_CA_Loss && !icsk->icsk_retransmits)) {
+		tp->prior_ssthresh = tcp_current_ssthresh(sk);
+		tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
+		tcp_ca_event(sk, CA_EVENT_LOSS);
+	}
+	tp->snd_cwnd	   = 1;
+	tp->snd_cwnd_cnt   = 0;
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+
+	tp->bytes_acked = 0;
+	tcp_clear_retrans_partial(tp);
+
+	if (tcp_is_reno(tp))
+		tcp_reset_reno_sack(tp);
+
+	if (!how) {
+		/* Push undo marker, if it was plain RTO and nothing
+		 * was retransmitted. */
+		tp->undo_marker = tp->snd_una;
+	} else {
+		tp->sacked_out = 0;
+		tp->fackets_out = 0;
+	}
+	tcp_clear_all_retrans_hints(tp);
+
+	tcp_for_write_queue(skb, sk) {
+		if (skb == tcp_send_head(sk))
+			break;
+
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS)
+			tp->undo_marker = 0;
+		TCP_SKB_CB(skb)->sacked &= (~TCPCB_TAGBITS)|TCPCB_SACKED_ACKED;
+		if (!(TCP_SKB_CB(skb)->sacked&TCPCB_SACKED_ACKED) || how) {
+			TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_ACKED;
+			TCP_SKB_CB(skb)->sacked |= TCPCB_LOST;
+			tp->lost_out += tcp_skb_pcount(skb);
+			tp->retransmit_high = TCP_SKB_CB(skb)->end_seq;
+		}
+	}
+	tcp_verify_left_out(tp);
+
+	tp->reordering = min_t(unsigned int, tp->reordering,
+			       sysctl_tcp_reordering);
+	tcp_set_ca_state(sk, TCP_CA_Loss);
+	tp->high_seq = tp->snd_nxt;
+	TCP_ECN_queue_cwr(tp);
+	/* Abort F-RTO algorithm if one is in progress */
+	tp->frto_counter = 0;
+}
+
+/* If ACK arrived pointing to a remembered SACK, it means that our
+ * remembered SACKs do not reflect real state of receiver i.e.
+ * receiver _host_ is heavily congested (or buggy).
+ *
+ * Do processing similar to RTO timeout.
+ */
+static int tcp_check_sack_reneging(struct sock *sk, int flag)
+{
+	if (flag & FLAG_SACK_RENEGING) {
+		struct inet_connection_sock *icsk = inet_csk(sk);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSACKRENEGING);
+
+		tcp_enter_loss(sk, 1);
+		icsk->icsk_retransmits++;
+		tcp_retransmit_skb(sk, tcp_write_queue_head(sk));
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+					  icsk->icsk_rto, TCP_RTO_MAX);
+		return 1;
+	}
+	return 0;
+}
+
+static inline int tcp_fackets_out(struct tcp_sock *tp)
+{
+	return tcp_is_reno(tp) ? tp->sacked_out + 1 : tp->fackets_out;
+}
+
+/* Heurestics to calculate number of duplicate ACKs. There's no dupACKs
+ * counter when SACK is enabled (without SACK, sacked_out is used for
+ * that purpose).
+ *
+ * Instead, with FACK TCP uses fackets_out that includes both SACKed
+ * segments up to the highest received SACK block so far and holes in
+ * between them.
+ *
+ * With reordering, holes may still be in flight, so RFC3517 recovery
+ * uses pure sacked_out (total number of SACKed segments) even though
+ * it violates the RFC that uses duplicate ACKs, often these are equal
+ * but when e.g. out-of-window ACKs or packet duplication occurs,
+ * they differ. Since neither occurs due to loss, TCP should really
+ * ignore them.
+ */
+static inline int tcp_dupack_heurestics(struct tcp_sock *tp)
+{
+	return tcp_is_fack(tp) ? tp->fackets_out : tp->sacked_out + 1;
+}
+
+static inline int tcp_skb_timedout(struct sock *sk, struct sk_buff *skb)
+{
+	return (tcp_time_stamp - TCP_SKB_CB(skb)->when > inet_csk(sk)->icsk_rto);
+}
+
+static inline int tcp_head_timedout(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	return tp->packets_out &&
+	       tcp_skb_timedout(sk, tcp_write_queue_head(sk));
+}
+
+/* Linux NewReno/SACK/FACK/ECN state machine.
+ * --------------------------------------
+ *
+ * "Open"	Normal state, no dubious events, fast path.
+ * "Disorder"   In all the respects it is "Open",
+ *		but requires a bit more attention. It is entered when
+ *		we see some SACKs or dupacks. It is split of "Open"
+ *		mainly to move some processing from fast path to slow one.
+ * "CWR"	CWND was reduced due to some Congestion Notification event.
+ *		It can be ECN, ICMP source quench, local device congestion.
+ * "Recovery"	CWND was reduced, we are fast-retransmitting.
+ * "Loss"	CWND was reduced due to RTO timeout or SACK reneging.
+ *
+ * tcp_fastretrans_alert() is entered:
+ * - each incoming ACK, if state is not "Open"
+ * - when arrived ACK is unusual, namely:
+ *	* SACK
+ *	* Duplicate ACK.
+ *	* ECN ECE.
+ *
+ * Counting packets in flight is pretty simple.
+ *
+ *	in_flight = packets_out - left_out + retrans_out
+ *
+ *	packets_out is SND.NXT-SND.UNA counted in packets.
+ *
+ *	retrans_out is number of retransmitted segments.
+ *
+ *	left_out is number of segments left network, but not ACKed yet.
+ *
+ *		left_out = sacked_out + lost_out
+ *
+ *     sacked_out: Packets, which arrived to receiver out of order
+ *		   and hence not ACKed. With SACKs this number is simply
+ *		   amount of SACKed data. Even without SACKs
+ *		   it is easy to give pretty reliable estimate of this number,
+ *		   counting duplicate ACKs.
+ *
+ *       lost_out: Packets lost by network. TCP has no explicit
+ *		   "loss notification" feedback from network (for now).
+ *		   It means that this number can be only _guessed_.
+ *		   Actually, it is the heuristics to predict lossage that
+ *		   distinguishes different algorithms.
+ *
+ *	F.e. after RTO, when all the queue is considered as lost,
+ *	lost_out = packets_out and in_flight = retrans_out.
+ *
+ *		Essentially, we have now two algorithms counting
+ *		lost packets.
+ *
+ *		FACK: It is the simplest heuristics. As soon as we decided
+ *		that something is lost, we decide that _all_ not SACKed
+ *		packets until the most forward SACK are lost. I.e.
+ *		lost_out = fackets_out - sacked_out and left_out = fackets_out.
+ *		It is absolutely correct estimate, if network does not reorder
+ *		packets. And it loses any connection to reality when reordering
+ *		takes place. We use FACK by default until reordering
+ *		is suspected on the path to this destination.
+ *
+ *		NewReno: when Recovery is entered, we assume that one segment
+ *		is lost (classic Reno). While we are in Recovery and
+ *		a partial ACK arrives, we assume that one more packet
+ *		is lost (NewReno). This heuristics are the same in NewReno
+ *		and SACK.
+ *
+ *  Imagine, that's all! Forget about all this shamanism about CWND inflation
+ *  deflation etc. CWND is real congestion window, never inflated, changes
+ *  only according to classic VJ rules.
+ *
+ * Really tricky (and requiring careful tuning) part of algorithm
+ * is hidden in functions tcp_time_to_recover() and tcp_xmit_retransmit_queue().
+ * The first determines the moment _when_ we should reduce CWND and,
+ * hence, slow down forward transmission. In fact, it determines the moment
+ * when we decide that hole is caused by loss, rather than by a reorder.
+ *
+ * tcp_xmit_retransmit_queue() decides, _what_ we should retransmit to fill
+ * holes, caused by lost packets.
+ *
+ * And the most logically complicated part of algorithm is undo
+ * heuristics. We detect false retransmits due to both too early
+ * fast retransmit (reordering) and underestimated RTO, analyzing
+ * timestamps and D-SACKs. When we detect that some segments were
+ * retransmitted by mistake and CWND reduction was wrong, we undo
+ * window reduction and abort recovery phase. This logic is hidden
+ * inside several functions named tcp_try_undo_<something>.
+ */
+
+/* This function decides, when we should leave Disordered state
+ * and enter Recovery phase, reducing congestion window.
+ *
+ * Main question: may we further continue forward transmission
+ * with the same cwnd?
+ */
+static int tcp_time_to_recover(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	__u32 packets_out;
+
+	/* Do not perform any recovery during F-RTO algorithm */
+	if (tp->frto_counter)
+		return 0;
+
+	/* Trick#1: The loss is proven. */
+	if (tp->lost_out)
+		return 1;
+
+	/* Not-A-Trick#2 : Classic rule... */
+	if (tcp_dupack_heurestics(tp) > tp->reordering)
+		return 1;
+
+	/* Trick#3 : when we use RFC2988 timer restart, fast
+	 * retransmit can be triggered by timeout of queue head.
+	 */
+	if (tcp_is_fack(tp) && tcp_head_timedout(sk))
+		return 1;
+
+	/* Trick#4: It is still not OK... But will it be useful to delay
+	 * recovery more?
+	 */
+	packets_out = tp->packets_out;
+	if (packets_out <= tp->reordering &&
+	    tp->sacked_out >= max_t(__u32, packets_out/2, sysctl_tcp_reordering) &&
+	    !tcp_may_send_now(sk)) {
+		/* We have nothing to send. This connection is limited
+		 * either by receiver window or by application.
+		 */
+		return 1;
+	}
+
+	return 0;
+}
+
+/* Mark head of queue up as lost. With RFC3517 SACK, the packets is
+ * is against sacked "cnt", otherwise it's against facked "cnt"
+ */
+static void tcp_mark_head_lost(struct sock *sk, int packets)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	int cnt, oldcnt;
+	int err;
+	unsigned int mss;
+
+	WARN_ON(packets > tp->packets_out);
+	if (tp->lost_skb_hint) {
+		skb = tp->lost_skb_hint;
+		cnt = tp->lost_cnt_hint;
+	} else {
+		skb = tcp_write_queue_head(sk);
+		cnt = 0;
+	}
+
+	tcp_for_write_queue_from(skb, sk) {
+		if (skb == tcp_send_head(sk))
+			break;
+		/* TODO: do this better */
+		/* this is not the most efficient way to do this... */
+		tp->lost_skb_hint = skb;
+		tp->lost_cnt_hint = cnt;
+
+		if (after(TCP_SKB_CB(skb)->end_seq, tp->high_seq))
+			break;
+
+		oldcnt = cnt;
+		if (tcp_is_fack(tp) || tcp_is_reno(tp) ||
+		    (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
+			cnt += tcp_skb_pcount(skb);
+
+		if (cnt > packets) {
+			if (tcp_is_sack(tp) || (oldcnt >= packets))
+				break;
+
+			mss = skb_shinfo(skb)->gso_size;
+			err = tcp_fragment(sk, skb, (packets - oldcnt) * mss, mss);
+			if (err < 0)
+				break;
+			cnt = packets;
+		}
+
+		tcp_skb_mark_lost(tp, skb);
+	}
+	tcp_verify_left_out(tp);
+}
+
+/* Account newly detected lost packet(s) */
+
+static void tcp_update_scoreboard(struct sock *sk, int fast_rexmit)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tcp_is_reno(tp)) {
+		tcp_mark_head_lost(sk, 1);
+	} else if (tcp_is_fack(tp)) {
+		int lost = tp->fackets_out - tp->reordering;
+		if (lost <= 0)
+			lost = 1;
+		tcp_mark_head_lost(sk, lost);
+	} else {
+		int sacked_upto = tp->sacked_out - tp->reordering;
+		if (sacked_upto < fast_rexmit)
+			sacked_upto = fast_rexmit;
+		tcp_mark_head_lost(sk, sacked_upto);
+	}
+
+	/* New heuristics: it is possible only after we switched
+	 * to restart timer each time when something is ACKed.
+	 * Hence, we can detect timed out packets during fast
+	 * retransmit without falling to slow start.
+	 */
+	if (tcp_is_fack(tp) && tcp_head_timedout(sk)) {
+		struct sk_buff *skb;
+
+		skb = tp->scoreboard_skb_hint ? tp->scoreboard_skb_hint
+			: tcp_write_queue_head(sk);
+
+		tcp_for_write_queue_from(skb, sk) {
+			if (skb == tcp_send_head(sk))
+				break;
+			if (!tcp_skb_timedout(sk, skb))
+				break;
+
+			tcp_skb_mark_lost(tp, skb);
+		}
+
+		tp->scoreboard_skb_hint = skb;
+
+		tcp_verify_left_out(tp);
+	}
+}
+
+/* CWND moderation, preventing bursts due to too big ACKs
+ * in dubious situations.
+ */
+static inline void tcp_moderate_cwnd(struct tcp_sock *tp)
+{
+	tp->snd_cwnd = min(tp->snd_cwnd,
+			   tcp_packets_in_flight(tp) + tcp_max_burst(tp));
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+}
+
+/* Lower bound on congestion window is slow start threshold
+ * unless congestion avoidance choice decides to overide it.
+ */
+static inline u32 tcp_cwnd_min(const struct sock *sk)
+{
+	const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops;
+
+	return ca_ops->min_cwnd ? ca_ops->min_cwnd(sk) : tcp_sk(sk)->snd_ssthresh;
+}
+
+/* Decrease cwnd each second ack. */
+static void tcp_cwnd_down(struct sock *sk, int flag)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int decr = tp->snd_cwnd_cnt + 1;
+
+	if ((flag & (FLAG_ANY_PROGRESS | FLAG_DSACKING_ACK)) ||
+	    (tcp_is_reno(tp) && !(flag & FLAG_NOT_DUP))) {
+		tp->snd_cwnd_cnt = decr & 1;
+		decr >>= 1;
+
+		if (decr && tp->snd_cwnd > tcp_cwnd_min(sk))
+			tp->snd_cwnd -= decr;
+
+		tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp) + 1);
+		tp->snd_cwnd_stamp = tcp_time_stamp;
+	}
+}
+
+/* Nothing was retransmitted or returned timestamp is less
+ * than timestamp of the first retransmission.
+ */
+static inline int tcp_packet_delayed(struct tcp_sock *tp)
+{
+	return !tp->retrans_stamp ||
+		(tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
+		 before(tp->rx_opt.rcv_tsecr, tp->retrans_stamp));
+}
+
+/* Undo procedures. */
+
+#if FASTRETRANS_DEBUG > 1
+static void DBGUNDO(struct sock *sk, const char *msg)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_sock *inet = inet_sk(sk);
+
+	if (sk->sk_family == AF_INET) {
+		printk(KERN_DEBUG "Undo %s " NIPQUAD_FMT "/%u c%u l%u ss%u/%u p%u\n",
+		       msg,
+		       NIPQUAD(inet->daddr), ntohs(inet->dport),
+		       tp->snd_cwnd, tcp_left_out(tp),
+		       tp->snd_ssthresh, tp->prior_ssthresh,
+		       tp->packets_out);
+	}
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	else if (sk->sk_family == AF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+		printk(KERN_DEBUG "Undo %s " NIP6_FMT "/%u c%u l%u ss%u/%u p%u\n",
+		       msg,
+		       NIP6(np->daddr), ntohs(inet->dport),
+		       tp->snd_cwnd, tcp_left_out(tp),
+		       tp->snd_ssthresh, tp->prior_ssthresh,
+		       tp->packets_out);
+	}
+#endif
+}
+#else
+#define DBGUNDO(x...) do { } while (0)
+#endif
+
+static void tcp_undo_cwr(struct sock *sk, const int undo)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tp->prior_ssthresh) {
+		const struct inet_connection_sock *icsk = inet_csk(sk);
+
+		if (icsk->icsk_ca_ops->undo_cwnd)
+			tp->snd_cwnd = icsk->icsk_ca_ops->undo_cwnd(sk);
+		else
+			tp->snd_cwnd = max(tp->snd_cwnd, tp->snd_ssthresh << 1);
+
+		if (undo && tp->prior_ssthresh > tp->snd_ssthresh) {
+			tp->snd_ssthresh = tp->prior_ssthresh;
+			TCP_ECN_withdraw_cwr(tp);
+		}
+	} else {
+		tp->snd_cwnd = max(tp->snd_cwnd, tp->snd_ssthresh);
+	}
+	tcp_moderate_cwnd(tp);
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+}
+
+static inline int tcp_may_undo(struct tcp_sock *tp)
+{
+	return tp->undo_marker && (!tp->undo_retrans || tcp_packet_delayed(tp));
+}
+
+/* People celebrate: "We love our President!" */
+static int tcp_try_undo_recovery(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tcp_may_undo(tp)) {
+		int mib_idx;
+
+		/* Happy end! We did not retransmit anything
+		 * or our original transmission succeeded.
+		 */
+		DBGUNDO(sk, inet_csk(sk)->icsk_ca_state == TCP_CA_Loss ? "loss" : "retrans");
+		tcp_undo_cwr(sk, 1);
+		if (inet_csk(sk)->icsk_ca_state == TCP_CA_Loss)
+			mib_idx = LINUX_MIB_TCPLOSSUNDO;
+		else
+			mib_idx = LINUX_MIB_TCPFULLUNDO;
+
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+		tp->undo_marker = 0;
+	}
+	if (tp->snd_una == tp->high_seq && tcp_is_reno(tp)) {
+		/* Hold old state until something *above* high_seq
+		 * is ACKed. For Reno it is MUST to prevent false
+		 * fast retransmits (RFC2582). SACK TCP is safe. */
+		tcp_moderate_cwnd(tp);
+		return 1;
+	}
+	tcp_set_ca_state(sk, TCP_CA_Open);
+	return 0;
+}
+
+/* Try to undo cwnd reduction, because D-SACKs acked all retransmitted data */
+static void tcp_try_undo_dsack(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tp->undo_marker && !tp->undo_retrans) {
+		DBGUNDO(sk, "D-SACK");
+		tcp_undo_cwr(sk, 1);
+		tp->undo_marker = 0;
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPDSACKUNDO);
+	}
+}
+
+/* Undo during fast recovery after partial ACK. */
+
+static int tcp_try_undo_partial(struct sock *sk, int acked)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	/* Partial ACK arrived. Force Hoe's retransmit. */
+	int failed = tcp_is_reno(tp) || (tcp_fackets_out(tp) > tp->reordering);
+
+	if (tcp_may_undo(tp)) {
+		/* Plain luck! Hole if filled with delayed
+		 * packet, rather than with a retransmit.
+		 */
+		if (tp->retrans_out == 0)
+			tp->retrans_stamp = 0;
+
+		tcp_update_reordering(sk, tcp_fackets_out(tp) + acked, 1);
+
+		DBGUNDO(sk, "Hoe");
+		tcp_undo_cwr(sk, 0);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPPARTIALUNDO);
+
+		/* So... Do not make Hoe's retransmit yet.
+		 * If the first packet was delayed, the rest
+		 * ones are most probably delayed as well.
+		 */
+		failed = 0;
+	}
+	return failed;
+}
+
+/* Undo during loss recovery after partial ACK. */
+static int tcp_try_undo_loss(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tcp_may_undo(tp)) {
+		struct sk_buff *skb;
+		tcp_for_write_queue(skb, sk) {
+			if (skb == tcp_send_head(sk))
+				break;
+			TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST;
+		}
+
+		tcp_clear_all_retrans_hints(tp);
+
+		DBGUNDO(sk, "partial loss");
+		tp->lost_out = 0;
+		tcp_undo_cwr(sk, 1);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSSUNDO);
+		inet_csk(sk)->icsk_retransmits = 0;
+		tp->undo_marker = 0;
+		if (tcp_is_sack(tp))
+			tcp_set_ca_state(sk, TCP_CA_Open);
+		return 1;
+	}
+	return 0;
+}
+
+static inline void tcp_complete_cwr(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+	tcp_ca_event(sk, CA_EVENT_COMPLETE_CWR);
+}
+
+static void tcp_try_keep_open(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int state = TCP_CA_Open;
+
+	if (tcp_left_out(tp) || tp->retrans_out || tp->undo_marker)
+		state = TCP_CA_Disorder;
+
+	if (inet_csk(sk)->icsk_ca_state != state) {
+		tcp_set_ca_state(sk, state);
+		tp->high_seq = tp->snd_nxt;
+	}
+}
+
+static void tcp_try_to_open(struct sock *sk, int flag)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	tcp_verify_left_out(tp);
+
+	if (!tp->frto_counter && tp->retrans_out == 0)
+		tp->retrans_stamp = 0;
+
+	if (flag & FLAG_ECE)
+		tcp_enter_cwr(sk, 1);
+
+	if (inet_csk(sk)->icsk_ca_state != TCP_CA_CWR) {
+		tcp_try_keep_open(sk);
+		tcp_moderate_cwnd(tp);
+	} else {
+		tcp_cwnd_down(sk, flag);
+	}
+}
+
+static void tcp_mtup_probe_failed(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	icsk->icsk_mtup.search_high = icsk->icsk_mtup.probe_size - 1;
+	icsk->icsk_mtup.probe_size = 0;
+}
+
+static void tcp_mtup_probe_success(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	/* FIXME: breaks with very large cwnd */
+	tp->prior_ssthresh = tcp_current_ssthresh(sk);
+	tp->snd_cwnd = tp->snd_cwnd *
+		       tcp_mss_to_mtu(sk, tp->mss_cache) /
+		       icsk->icsk_mtup.probe_size;
+	tp->snd_cwnd_cnt = 0;
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+	tp->rcv_ssthresh = tcp_current_ssthresh(sk);
+
+	icsk->icsk_mtup.search_low = icsk->icsk_mtup.probe_size;
+	icsk->icsk_mtup.probe_size = 0;
+	tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+}
+
+/* Process an event, which can update packets-in-flight not trivially.
+ * Main goal of this function is to calculate new estimate for left_out,
+ * taking into account both packets sitting in receiver's buffer and
+ * packets lost by network.
+ *
+ * Besides that it does CWND reduction, when packet loss is detected
+ * and changes state of machine.
+ *
+ * It does _not_ decide what to send, it is made in function
+ * tcp_xmit_retransmit_queue().
+ */
+static void tcp_fastretrans_alert(struct sock *sk, int pkts_acked, int flag)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP));
+	int do_lost = is_dupack || ((flag & FLAG_DATA_SACKED) &&
+				    (tcp_fackets_out(tp) > tp->reordering));
+	int fast_rexmit = 0, mib_idx;
+
+	if (WARN_ON(!tp->packets_out && tp->sacked_out))
+		tp->sacked_out = 0;
+	if (WARN_ON(!tp->sacked_out && tp->fackets_out))
+		tp->fackets_out = 0;
+
+	/* Now state machine starts.
+	 * A. ECE, hence prohibit cwnd undoing, the reduction is required. */
+	if (flag & FLAG_ECE)
+		tp->prior_ssthresh = 0;
+
+	/* B. In all the states check for reneging SACKs. */
+	if (tcp_check_sack_reneging(sk, flag))
+		return;
+
+	/* C. Process data loss notification, provided it is valid. */
+	if (tcp_is_fack(tp) && (flag & FLAG_DATA_LOST) &&
+	    before(tp->snd_una, tp->high_seq) &&
+	    icsk->icsk_ca_state != TCP_CA_Open &&
+	    tp->fackets_out > tp->reordering) {
+		tcp_mark_head_lost(sk, tp->fackets_out - tp->reordering);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPLOSS);
+	}
+
+	/* D. Check consistency of the current state. */
+	tcp_verify_left_out(tp);
+
+	/* E. Check state exit conditions. State can be terminated
+	 *    when high_seq is ACKed. */
+	if (icsk->icsk_ca_state == TCP_CA_Open) {
+		WARN_ON(tp->retrans_out != 0);
+		tp->retrans_stamp = 0;
+	} else if (!before(tp->snd_una, tp->high_seq)) {
+		switch (icsk->icsk_ca_state) {
+		case TCP_CA_Loss:
+			icsk->icsk_retransmits = 0;
+			if (tcp_try_undo_recovery(sk))
+				return;
+			break;
+
+		case TCP_CA_CWR:
+			/* CWR is to be held something *above* high_seq
+			 * is ACKed for CWR bit to reach receiver. */
+			if (tp->snd_una != tp->high_seq) {
+				tcp_complete_cwr(sk);
+				tcp_set_ca_state(sk, TCP_CA_Open);
+			}
+			break;
+
+		case TCP_CA_Disorder:
+			tcp_try_undo_dsack(sk);
+			if (!tp->undo_marker ||
+			    /* For SACK case do not Open to allow to undo
+			     * catching for all duplicate ACKs. */
+			    tcp_is_reno(tp) || tp->snd_una != tp->high_seq) {
+				tp->undo_marker = 0;
+				tcp_set_ca_state(sk, TCP_CA_Open);
+			}
+			break;
+
+		case TCP_CA_Recovery:
+			if (tcp_is_reno(tp))
+				tcp_reset_reno_sack(tp);
+			if (tcp_try_undo_recovery(sk))
+				return;
+			tcp_complete_cwr(sk);
+			break;
+		}
+	}
+
+	/* F. Process state. */
+	switch (icsk->icsk_ca_state) {
+	case TCP_CA_Recovery:
+		if (!(flag & FLAG_SND_UNA_ADVANCED)) {
+			if (tcp_is_reno(tp) && is_dupack)
+				tcp_add_reno_sack(sk);
+		} else
+			do_lost = tcp_try_undo_partial(sk, pkts_acked);
+		break;
+	case TCP_CA_Loss:
+		if (flag & FLAG_DATA_ACKED)
+			icsk->icsk_retransmits = 0;
+		if (tcp_is_reno(tp) && flag & FLAG_SND_UNA_ADVANCED)
+			tcp_reset_reno_sack(tp);
+		if (!tcp_try_undo_loss(sk)) {
+			tcp_moderate_cwnd(tp);
+			tcp_xmit_retransmit_queue(sk);
+			return;
+		}
+		if (icsk->icsk_ca_state != TCP_CA_Open)
+			return;
+		/* Loss is undone; fall through to processing in Open state. */
+	default:
+		if (tcp_is_reno(tp)) {
+			if (flag & FLAG_SND_UNA_ADVANCED)
+				tcp_reset_reno_sack(tp);
+			if (is_dupack)
+				tcp_add_reno_sack(sk);
+		}
+
+		if (icsk->icsk_ca_state == TCP_CA_Disorder)
+			tcp_try_undo_dsack(sk);
+
+		if (!tcp_time_to_recover(sk)) {
+			tcp_try_to_open(sk, flag);
+			return;
+		}
+
+		/* MTU probe failure: don't reduce cwnd */
+		if (icsk->icsk_ca_state < TCP_CA_CWR &&
+		    icsk->icsk_mtup.probe_size &&
+		    tp->snd_una == tp->mtu_probe.probe_seq_start) {
+			tcp_mtup_probe_failed(sk);
+			/* Restores the reduction we did in tcp_mtup_probe() */
+			tp->snd_cwnd++;
+			tcp_simple_retransmit(sk);
+			return;
+		}
+
+		/* Otherwise enter Recovery state */
+
+		if (tcp_is_reno(tp))
+			mib_idx = LINUX_MIB_TCPRENORECOVERY;
+		else
+			mib_idx = LINUX_MIB_TCPSACKRECOVERY;
+
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+
+		tp->high_seq = tp->snd_nxt;
+		tp->prior_ssthresh = 0;
+		tp->undo_marker = tp->snd_una;
+		tp->undo_retrans = tp->retrans_out;
+
+		if (icsk->icsk_ca_state < TCP_CA_CWR) {
+			if (!(flag & FLAG_ECE))
+				tp->prior_ssthresh = tcp_current_ssthresh(sk);
+			tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
+			TCP_ECN_queue_cwr(tp);
+		}
+
+		tp->bytes_acked = 0;
+		tp->snd_cwnd_cnt = 0;
+		tcp_set_ca_state(sk, TCP_CA_Recovery);
+		fast_rexmit = 1;
+	}
+
+	if (do_lost || (tcp_is_fack(tp) && tcp_head_timedout(sk)))
+		tcp_update_scoreboard(sk, fast_rexmit);
+	tcp_cwnd_down(sk, flag);
+	tcp_xmit_retransmit_queue(sk);
+}
+
+/* Read draft-ietf-tcplw-high-performance before mucking
+ * with this code. (Supersedes RFC1323)
+ */
+static void tcp_ack_saw_tstamp(struct sock *sk, int flag)
+{
+	/* RTTM Rule: A TSecr value received in a segment is used to
+	 * update the averaged RTT measurement only if the segment
+	 * acknowledges some new data, i.e., only if it advances the
+	 * left edge of the send window.
+	 *
+	 * See draft-ietf-tcplw-high-performance-00, section 3.3.
+	 * 1998/04/10 Andrey V. Savochkin <saw@msu.ru>
+	 *
+	 * Changed: reset backoff as soon as we see the first valid sample.
+	 * If we do not, we get strongly overestimated rto. With timestamps
+	 * samples are accepted even from very old segments: f.e., when rtt=1
+	 * increases to 8, we retransmit 5 times and after 8 seconds delayed
+	 * answer arrives rto becomes 120 seconds! If at least one of segments
+	 * in window is lost... Voila.	 			--ANK (010210)
+	 */
+	struct tcp_sock *tp = tcp_sk(sk);
+	const __u32 seq_rtt = tcp_time_stamp - tp->rx_opt.rcv_tsecr;
+	tcp_rtt_estimator(sk, seq_rtt);
+	tcp_set_rto(sk);
+	inet_csk(sk)->icsk_backoff = 0;
+	tcp_bound_rto(sk);
+}
+
+static void tcp_ack_no_tstamp(struct sock *sk, u32 seq_rtt, int flag)
+{
+	/* We don't have a timestamp. Can only use
+	 * packets that are not retransmitted to determine
+	 * rtt estimates. Also, we must not reset the
+	 * backoff for rto until we get a non-retransmitted
+	 * packet. This allows us to deal with a situation
+	 * where the network delay has increased suddenly.
+	 * I.e. Karn's algorithm. (SIGCOMM '87, p5.)
+	 */
+
+	if (flag & FLAG_RETRANS_DATA_ACKED)
+		return;
+
+	tcp_rtt_estimator(sk, seq_rtt);
+	tcp_set_rto(sk);
+	inet_csk(sk)->icsk_backoff = 0;
+	tcp_bound_rto(sk);
+}
+
+static inline void tcp_ack_update_rtt(struct sock *sk, const int flag,
+				      const s32 seq_rtt)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	/* Note that peer MAY send zero echo. In this case it is ignored. (rfc1323) */
+	if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
+		tcp_ack_saw_tstamp(sk, flag);
+	else if (seq_rtt >= 0)
+		tcp_ack_no_tstamp(sk, seq_rtt, flag);
+}
+
+static void tcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	icsk->icsk_ca_ops->cong_avoid(sk, ack, in_flight);
+	tcp_sk(sk)->snd_cwnd_stamp = tcp_time_stamp;
+}
+
+/* Restart timer after forward progress on connection.
+ * RFC2988 recommends to restart timer to now+rto.
+ */
+static void tcp_rearm_rto(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!tp->packets_out) {
+		inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
+	} else {
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+					  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
+	}
+}
+
+/* If we get here, the whole TSO packet has not been acked. */
+static u32 tcp_tso_acked(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 packets_acked;
+
+	BUG_ON(!after(TCP_SKB_CB(skb)->end_seq, tp->snd_una));
+
+	packets_acked = tcp_skb_pcount(skb);
+	if (tcp_trim_head(sk, skb, tp->snd_una - TCP_SKB_CB(skb)->seq))
+		return 0;
+	packets_acked -= tcp_skb_pcount(skb);
+
+	if (packets_acked) {
+		BUG_ON(tcp_skb_pcount(skb) == 0);
+		BUG_ON(!before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq));
+	}
+
+	return packets_acked;
+}
+
+/* Remove acknowledged frames from the retransmission queue. If our packet
+ * is before the ack sequence we can discard it as it's confirmed to have
+ * arrived at the other end.
+ */
+static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
+			       u32 prior_snd_una)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct sk_buff *skb;
+	u32 now = tcp_time_stamp;
+	int fully_acked = 1;
+	int flag = 0;
+	u32 pkts_acked = 0;
+	u32 reord = tp->packets_out;
+	u32 prior_sacked = tp->sacked_out;
+	s32 seq_rtt = -1;
+	s32 ca_seq_rtt = -1;
+	ktime_t last_ackt = net_invalid_timestamp();
+
+	while ((skb = tcp_write_queue_head(sk)) && skb != tcp_send_head(sk)) {
+		struct tcp_skb_cb *scb = TCP_SKB_CB(skb);
+		u32 end_seq;
+		u32 acked_pcount;
+		u8 sacked = scb->sacked;
+
+		/* Determine how many packets and what bytes were acked, tso and else */
+		if (after(scb->end_seq, tp->snd_una)) {
+			if (tcp_skb_pcount(skb) == 1 ||
+			    !after(tp->snd_una, scb->seq))
+				break;
+
+			acked_pcount = tcp_tso_acked(sk, skb);
+			if (!acked_pcount)
+				break;
+
+			fully_acked = 0;
+			end_seq = tp->snd_una;
+		} else {
+			acked_pcount = tcp_skb_pcount(skb);
+			end_seq = scb->end_seq;
+		}
+
+		/* MTU probing checks */
+		if (fully_acked && icsk->icsk_mtup.probe_size &&
+		    !after(tp->mtu_probe.probe_seq_end, scb->end_seq)) {
+			tcp_mtup_probe_success(sk, skb);
+		}
+
+		if (sacked & TCPCB_RETRANS) {
+			if (sacked & TCPCB_SACKED_RETRANS)
+				tp->retrans_out -= acked_pcount;
+			flag |= FLAG_RETRANS_DATA_ACKED;
+			ca_seq_rtt = -1;
+			seq_rtt = -1;
+			if ((flag & FLAG_DATA_ACKED) || (acked_pcount > 1))
+				flag |= FLAG_NONHEAD_RETRANS_ACKED;
+		} else {
+			ca_seq_rtt = now - scb->when;
+			last_ackt = skb->tstamp;
+			if (seq_rtt < 0) {
+				seq_rtt = ca_seq_rtt;
+			}
+			if (!(sacked & TCPCB_SACKED_ACKED))
+				reord = min(pkts_acked, reord);
+		}
+
+		if (sacked & TCPCB_SACKED_ACKED)
+			tp->sacked_out -= acked_pcount;
+		if (sacked & TCPCB_LOST)
+			tp->lost_out -= acked_pcount;
+
+		tp->packets_out -= acked_pcount;
+		pkts_acked += acked_pcount;
+
+		/* Initial outgoing SYN's get put onto the write_queue
+		 * just like anything else we transmit.  It is not
+		 * true data, and if we misinform our callers that
+		 * this ACK acks real data, we will erroneously exit
+		 * connection startup slow start one packet too
+		 * quickly.  This is severely frowned upon behavior.
+		 */
+		if (!(scb->flags & TCPCB_FLAG_SYN)) {
+			flag |= FLAG_DATA_ACKED;
+		} else {
+			flag |= FLAG_SYN_ACKED;
+			tp->retrans_stamp = 0;
+		}
+
+		if (!fully_acked)
+			break;
+
+		tcp_unlink_write_queue(skb, sk);
+		sk_wmem_free_skb(sk, skb);
+		tp->scoreboard_skb_hint = NULL;
+		if (skb == tp->retransmit_skb_hint)
+			tp->retransmit_skb_hint = NULL;
+		if (skb == tp->lost_skb_hint)
+			tp->lost_skb_hint = NULL;
+	}
+
+	if (likely(between(tp->snd_up, prior_snd_una, tp->snd_una)))
+		tp->snd_up = tp->snd_una;
+
+	if (skb && (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED))
+		flag |= FLAG_SACK_RENEGING;
+
+	if (flag & FLAG_ACKED) {
+		const struct tcp_congestion_ops *ca_ops
+			= inet_csk(sk)->icsk_ca_ops;
+
+		tcp_ack_update_rtt(sk, flag, seq_rtt);
+		tcp_rearm_rto(sk);
+
+		if (tcp_is_reno(tp)) {
+			tcp_remove_reno_sacks(sk, pkts_acked);
+		} else {
+			/* Non-retransmitted hole got filled? That's reordering */
+			if (reord < prior_fackets)
+				tcp_update_reordering(sk, tp->fackets_out - reord, 0);
+
+			/* No need to care for underflows here because
+			 * the lost_skb_hint gets NULLed if we're past it
+			 * (or something non-trivial happened)
+			 */
+			if (tcp_is_fack(tp))
+				tp->lost_cnt_hint -= pkts_acked;
+			else
+				tp->lost_cnt_hint -= prior_sacked - tp->sacked_out;
+		}
+
+		tp->fackets_out -= min(pkts_acked, tp->fackets_out);
+
+		if (ca_ops->pkts_acked) {
+			s32 rtt_us = -1;
+
+			/* Is the ACK triggering packet unambiguous? */
+			if (!(flag & FLAG_RETRANS_DATA_ACKED)) {
+				/* High resolution needed and available? */
+				if (ca_ops->flags & TCP_CONG_RTT_STAMP &&
+				    !ktime_equal(last_ackt,
+						 net_invalid_timestamp()))
+					rtt_us = ktime_us_delta(ktime_get_real(),
+								last_ackt);
+				else if (ca_seq_rtt > 0)
+					rtt_us = jiffies_to_usecs(ca_seq_rtt);
+			}
+
+			ca_ops->pkts_acked(sk, pkts_acked, rtt_us);
+		}
+	}
+
+#if FASTRETRANS_DEBUG > 0
+	WARN_ON((int)tp->sacked_out < 0);
+	WARN_ON((int)tp->lost_out < 0);
+	WARN_ON((int)tp->retrans_out < 0);
+	if (!tp->packets_out && tcp_is_sack(tp)) {
+		icsk = inet_csk(sk);
+		if (tp->lost_out) {
+			printk(KERN_DEBUG "Leak l=%u %d\n",
+			       tp->lost_out, icsk->icsk_ca_state);
+			tp->lost_out = 0;
+		}
+		if (tp->sacked_out) {
+			printk(KERN_DEBUG "Leak s=%u %d\n",
+			       tp->sacked_out, icsk->icsk_ca_state);
+			tp->sacked_out = 0;
+		}
+		if (tp->retrans_out) {
+			printk(KERN_DEBUG "Leak r=%u %d\n",
+			       tp->retrans_out, icsk->icsk_ca_state);
+			tp->retrans_out = 0;
+		}
+	}
+#endif
+	return flag;
+}
+
+static void tcp_ack_probe(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	/* Was it a usable window open? */
+
+	if (!after(TCP_SKB_CB(tcp_send_head(sk))->end_seq, tcp_wnd_end(tp))) {
+		icsk->icsk_backoff = 0;
+		inet_csk_clear_xmit_timer(sk, ICSK_TIME_PROBE0);
+		/* Socket must be waked up by subsequent tcp_data_snd_check().
+		 * This function is not for random using!
+		 */
+	} else {
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+					  min(icsk->icsk_rto << icsk->icsk_backoff, TCP_RTO_MAX),
+					  TCP_RTO_MAX);
+	}
+}
+
+static inline int tcp_ack_is_dubious(const struct sock *sk, const int flag)
+{
+	return (!(flag & FLAG_NOT_DUP) || (flag & FLAG_CA_ALERT) ||
+		inet_csk(sk)->icsk_ca_state != TCP_CA_Open);
+}
+
+static inline int tcp_may_raise_cwnd(const struct sock *sk, const int flag)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	return (!(flag & FLAG_ECE) || tp->snd_cwnd < tp->snd_ssthresh) &&
+		!((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_Recovery | TCPF_CA_CWR));
+}
+
+/* Check that window update is acceptable.
+ * The function assumes that snd_una<=ack<=snd_next.
+ */
+static inline int tcp_may_update_window(const struct tcp_sock *tp,
+					const u32 ack, const u32 ack_seq,
+					const u32 nwin)
+{
+	return (after(ack, tp->snd_una) ||
+		after(ack_seq, tp->snd_wl1) ||
+		(ack_seq == tp->snd_wl1 && nwin > tp->snd_wnd));
+}
+
+/* Update our send window.
+ *
+ * Window update algorithm, described in RFC793/RFC1122 (used in linux-2.2
+ * and in FreeBSD. NetBSD's one is even worse.) is wrong.
+ */
+static int tcp_ack_update_window(struct sock *sk, struct sk_buff *skb, u32 ack,
+				 u32 ack_seq)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int flag = 0;
+	u32 nwin = ntohs(tcp_hdr(skb)->window);
+
+	if (likely(!tcp_hdr(skb)->syn))
+		nwin <<= tp->rx_opt.snd_wscale;
+
+	if (tcp_may_update_window(tp, ack, ack_seq, nwin)) {
+		flag |= FLAG_WIN_UPDATE;
+		tcp_update_wl(tp, ack, ack_seq);
+
+		if (tp->snd_wnd != nwin) {
+			tp->snd_wnd = nwin;
+
+			/* Note, it is the only place, where
+			 * fast path is recovered for sending TCP.
+			 */
+			tp->pred_flags = 0;
+			tcp_fast_path_check(sk);
+
+			if (nwin > tp->max_window) {
+				tp->max_window = nwin;
+				tcp_sync_mss(sk, inet_csk(sk)->icsk_pmtu_cookie);
+			}
+		}
+	}
+
+	tp->snd_una = ack;
+
+	return flag;
+}
+
+/* A very conservative spurious RTO response algorithm: reduce cwnd and
+ * continue in congestion avoidance.
+ */
+static void tcp_conservative_spur_to_response(struct tcp_sock *tp)
+{
+	tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh);
+	tp->snd_cwnd_cnt = 0;
+	tp->bytes_acked = 0;
+	TCP_ECN_queue_cwr(tp);
+	tcp_moderate_cwnd(tp);
+}
+
+/* A conservative spurious RTO response algorithm: reduce cwnd using
+ * rate halving and continue in congestion avoidance.
+ */
+static void tcp_ratehalving_spur_to_response(struct sock *sk)
+{
+	tcp_enter_cwr(sk, 0);
+}
+
+static void tcp_undo_spur_to_response(struct sock *sk, int flag)
+{
+	if (flag & FLAG_ECE)
+		tcp_ratehalving_spur_to_response(sk);
+	else
+		tcp_undo_cwr(sk, 1);
+}
+
+/* F-RTO spurious RTO detection algorithm (RFC4138)
+ *
+ * F-RTO affects during two new ACKs following RTO (well, almost, see inline
+ * comments). State (ACK number) is kept in frto_counter. When ACK advances
+ * window (but not to or beyond highest sequence sent before RTO):
+ *   On First ACK,  send two new segments out.
+ *   On Second ACK, RTO was likely spurious. Do spurious response (response
+ *                  algorithm is not part of the F-RTO detection algorithm
+ *                  given in RFC4138 but can be selected separately).
+ * Otherwise (basically on duplicate ACK), RTO was (likely) caused by a loss
+ * and TCP falls back to conventional RTO recovery. F-RTO allows overriding
+ * of Nagle, this is done using frto_counter states 2 and 3, when a new data
+ * segment of any size sent during F-RTO, state 2 is upgraded to 3.
+ *
+ * Rationale: if the RTO was spurious, new ACKs should arrive from the
+ * original window even after we transmit two new data segments.
+ *
+ * SACK version:
+ *   on first step, wait until first cumulative ACK arrives, then move to
+ *   the second step. In second step, the next ACK decides.
+ *
+ * F-RTO is implemented (mainly) in four functions:
+ *   - tcp_use_frto() is used to determine if TCP is can use F-RTO
+ *   - tcp_enter_frto() prepares TCP state on RTO if F-RTO is used, it is
+ *     called when tcp_use_frto() showed green light
+ *   - tcp_process_frto() handles incoming ACKs during F-RTO algorithm
+ *   - tcp_enter_frto_loss() is called if there is not enough evidence
+ *     to prove that the RTO is indeed spurious. It transfers the control
+ *     from F-RTO to the conventional RTO recovery
+ */
+static int tcp_process_frto(struct sock *sk, int flag)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	tcp_verify_left_out(tp);
+
+	/* Duplicate the behavior from Loss state (fastretrans_alert) */
+	if (flag & FLAG_DATA_ACKED)
+		inet_csk(sk)->icsk_retransmits = 0;
+
+	if ((flag & FLAG_NONHEAD_RETRANS_ACKED) ||
+	    ((tp->frto_counter >= 2) && (flag & FLAG_RETRANS_DATA_ACKED)))
+		tp->undo_marker = 0;
+
+	if (!before(tp->snd_una, tp->frto_highmark)) {
+		tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 2 : 3), flag);
+		return 1;
+	}
+
+	if (!tcp_is_sackfrto(tp)) {
+		/* RFC4138 shortcoming in step 2; should also have case c):
+		 * ACK isn't duplicate nor advances window, e.g., opposite dir
+		 * data, winupdate
+		 */
+		if (!(flag & FLAG_ANY_PROGRESS) && (flag & FLAG_NOT_DUP))
+			return 1;
+
+		if (!(flag & FLAG_DATA_ACKED)) {
+			tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 0 : 3),
+					    flag);
+			return 1;
+		}
+	} else {
+		if (!(flag & FLAG_DATA_ACKED) && (tp->frto_counter == 1)) {
+			/* Prevent sending of new data. */
+			tp->snd_cwnd = min(tp->snd_cwnd,
+					   tcp_packets_in_flight(tp));
+			return 1;
+		}
+
+		if ((tp->frto_counter >= 2) &&
+		    (!(flag & FLAG_FORWARD_PROGRESS) ||
+		     ((flag & FLAG_DATA_SACKED) &&
+		      !(flag & FLAG_ONLY_ORIG_SACKED)))) {
+			/* RFC4138 shortcoming (see comment above) */
+			if (!(flag & FLAG_FORWARD_PROGRESS) &&
+			    (flag & FLAG_NOT_DUP))
+				return 1;
+
+			tcp_enter_frto_loss(sk, 3, flag);
+			return 1;
+		}
+	}
+
+	if (tp->frto_counter == 1) {
+		/* tcp_may_send_now needs to see updated state */
+		tp->snd_cwnd = tcp_packets_in_flight(tp) + 2;
+		tp->frto_counter = 2;
+
+		if (!tcp_may_send_now(sk))
+			tcp_enter_frto_loss(sk, 2, flag);
+
+		return 1;
+	} else {
+		switch (sysctl_tcp_frto_response) {
+		case 2:
+			tcp_undo_spur_to_response(sk, flag);
+			break;
+		case 1:
+			tcp_conservative_spur_to_response(tp);
+			break;
+		default:
+			tcp_ratehalving_spur_to_response(sk);
+			break;
+		}
+		tp->frto_counter = 0;
+		tp->undo_marker = 0;
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSPURIOUSRTOS);
+	}
+	return 0;
+}
+
+/* This routine deals with incoming acks, but not outgoing ones. */
+static int tcp_ack(struct sock *sk, struct sk_buff *skb, int flag)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 prior_snd_una = tp->snd_una;
+	u32 ack_seq = TCP_SKB_CB(skb)->seq;
+	u32 ack = TCP_SKB_CB(skb)->ack_seq;
+	u32 prior_in_flight;
+	u32 prior_fackets;
+	int prior_packets;
+	int frto_cwnd = 0;
+
+	/* If the ack is newer than sent or older than previous acks
+	 * then we can probably ignore it.
+	 */
+	if (after(ack, tp->snd_nxt))
+		goto uninteresting_ack;
+
+	if (before(ack, prior_snd_una))
+		goto old_ack;
+
+	if (after(ack, prior_snd_una))
+		flag |= FLAG_SND_UNA_ADVANCED;
+
+	if (sysctl_tcp_abc) {
+		if (icsk->icsk_ca_state < TCP_CA_CWR)
+			tp->bytes_acked += ack - prior_snd_una;
+		else if (icsk->icsk_ca_state == TCP_CA_Loss)
+			/* we assume just one segment left network */
+			tp->bytes_acked += min(ack - prior_snd_una,
+					       tp->mss_cache);
+	}
+
+	prior_fackets = tp->fackets_out;
+	prior_in_flight = tcp_packets_in_flight(tp);
+
+	if (!(flag & FLAG_SLOWPATH) && after(ack, prior_snd_una)) {
+		/* Window is constant, pure forward advance.
+		 * No more checks are required.
+		 * Note, we use the fact that SND.UNA>=SND.WL2.
+		 */
+		tcp_update_wl(tp, ack, ack_seq);
+		tp->snd_una = ack;
+		flag |= FLAG_WIN_UPDATE;
+
+		tcp_ca_event(sk, CA_EVENT_FAST_ACK);
+
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPACKS);
+	} else {
+		if (ack_seq != TCP_SKB_CB(skb)->end_seq)
+			flag |= FLAG_DATA;
+		else
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPPUREACKS);
+
+		flag |= tcp_ack_update_window(sk, skb, ack, ack_seq);
+
+		if (TCP_SKB_CB(skb)->sacked)
+			flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una);
+
+		if (TCP_ECN_rcv_ecn_echo(tp, tcp_hdr(skb)))
+			flag |= FLAG_ECE;
+
+		tcp_ca_event(sk, CA_EVENT_SLOW_ACK);
+	}
+
+	/* We passed data and got it acked, remove any soft error
+	 * log. Something worked...
+	 */
+	sk->sk_err_soft = 0;
+	icsk->icsk_probes_out = 0;
+	tp->rcv_tstamp = tcp_time_stamp;
+	prior_packets = tp->packets_out;
+	if (!prior_packets)
+		goto no_queue;
+
+	/* See if we can take anything off of the retransmit queue. */
+	flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una);
+
+	if (tp->frto_counter)
+		frto_cwnd = tcp_process_frto(sk, flag);
+	/* Guarantee sacktag reordering detection against wrap-arounds */
+	if (before(tp->frto_highmark, tp->snd_una))
+		tp->frto_highmark = 0;
+
+	if (tcp_ack_is_dubious(sk, flag)) {
+		/* Advance CWND, if state allows this. */
+		if ((flag & FLAG_DATA_ACKED) && !frto_cwnd &&
+		    tcp_may_raise_cwnd(sk, flag))
+			tcp_cong_avoid(sk, ack, prior_in_flight);
+		tcp_fastretrans_alert(sk, prior_packets - tp->packets_out,
+				      flag);
+	} else {
+		if ((flag & FLAG_DATA_ACKED) && !frto_cwnd)
+			tcp_cong_avoid(sk, ack, prior_in_flight);
+	}
+
+	if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP))
+		dst_confirm(sk->sk_dst_cache);
+
+	return 1;
+
+no_queue:
+	/* If this ack opens up a zero window, clear backoff.  It was
+	 * being used to time the probes, and is probably far higher than
+	 * it needs to be for normal retransmission.
+	 */
+	if (tcp_send_head(sk))
+		tcp_ack_probe(sk);
+	return 1;
+
+old_ack:
+	if (TCP_SKB_CB(skb)->sacked) {
+		tcp_sacktag_write_queue(sk, skb, prior_snd_una);
+		if (icsk->icsk_ca_state == TCP_CA_Open)
+			tcp_try_keep_open(sk);
+	}
+
+uninteresting_ack:
+	SOCK_DEBUG(sk, "Ack %u out of %u:%u\n", ack, tp->snd_una, tp->snd_nxt);
+	return 0;
+}
+
+/* Look for tcp options. Normally only called on SYN and SYNACK packets.
+ * But, this can also be called on packets in the established flow when
+ * the fast version below fails.
+ */
+void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx,
+		       int estab)
+{
+	unsigned char *ptr;
+	struct tcphdr *th = tcp_hdr(skb);
+	int length = (th->doff * 4) - sizeof(struct tcphdr);
+
+	ptr = (unsigned char *)(th + 1);
+	opt_rx->saw_tstamp = 0;
+
+	while (length > 0) {
+		int opcode = *ptr++;
+		int opsize;
+
+		switch (opcode) {
+		case TCPOPT_EOL:
+			return;
+		case TCPOPT_NOP:	/* Ref: RFC 793 section 3.1 */
+			length--;
+			continue;
+		default:
+			opsize = *ptr++;
+			if (opsize < 2) /* "silly options" */
+				return;
+			if (opsize > length)
+				return;	/* don't parse partial options */
+			switch (opcode) {
+			case TCPOPT_MSS:
+				if (opsize == TCPOLEN_MSS && th->syn && !estab) {
+					u16 in_mss = get_unaligned_be16(ptr);
+					if (in_mss) {
+						if (opt_rx->user_mss &&
+						    opt_rx->user_mss < in_mss)
+							in_mss = opt_rx->user_mss;
+						opt_rx->mss_clamp = in_mss;
+					}
+				}
+				break;
+			case TCPOPT_WINDOW:
+				if (opsize == TCPOLEN_WINDOW && th->syn &&
+				    !estab && sysctl_tcp_window_scaling) {
+					__u8 snd_wscale = *(__u8 *)ptr;
+					opt_rx->wscale_ok = 1;
+					if (snd_wscale > 14) {
+						if (net_ratelimit())
+							printk(KERN_INFO "tcp_parse_options: Illegal window "
+							       "scaling value %d >14 received.\n",
+							       snd_wscale);
+						snd_wscale = 14;
+					}
+					opt_rx->snd_wscale = snd_wscale;
+				}
+				break;
+			case TCPOPT_TIMESTAMP:
+				if ((opsize == TCPOLEN_TIMESTAMP) &&
+				    ((estab && opt_rx->tstamp_ok) ||
+				     (!estab && sysctl_tcp_timestamps))) {
+					opt_rx->saw_tstamp = 1;
+					opt_rx->rcv_tsval = get_unaligned_be32(ptr);
+					opt_rx->rcv_tsecr = get_unaligned_be32(ptr + 4);
+				}
+				break;
+			case TCPOPT_SACK_PERM:
+				if (opsize == TCPOLEN_SACK_PERM && th->syn &&
+				    !estab && sysctl_tcp_sack) {
+					opt_rx->sack_ok = 1;
+					tcp_sack_reset(opt_rx);
+				}
+				break;
+
+			case TCPOPT_SACK:
+				if ((opsize >= (TCPOLEN_SACK_BASE + TCPOLEN_SACK_PERBLOCK)) &&
+				   !((opsize - TCPOLEN_SACK_BASE) % TCPOLEN_SACK_PERBLOCK) &&
+				   opt_rx->sack_ok) {
+					TCP_SKB_CB(skb)->sacked = (ptr - 2) - (unsigned char *)th;
+				}
+				break;
+#ifdef CONFIG_TCP_MD5SIG
+			case TCPOPT_MD5SIG:
+				/*
+				 * The MD5 Hash has already been
+				 * checked (see tcp_v{4,6}_do_rcv()).
+				 */
+				break;
+#endif
+			}
+
+			ptr += opsize-2;
+			length -= opsize;
+		}
+	}
+}
+
+static int tcp_parse_aligned_timestamp(struct tcp_sock *tp, struct tcphdr *th)
+{
+	__be32 *ptr = (__be32 *)(th + 1);
+
+	if (*ptr == htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16)
+			  | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)) {
+		tp->rx_opt.saw_tstamp = 1;
+		++ptr;
+		tp->rx_opt.rcv_tsval = ntohl(*ptr);
+		++ptr;
+		tp->rx_opt.rcv_tsecr = ntohl(*ptr);
+		return 1;
+	}
+	return 0;
+}
+
+/* Fast parse options. This hopes to only see timestamps.
+ * If it is wrong it falls back on tcp_parse_options().
+ */
+static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
+				  struct tcp_sock *tp)
+{
+	if (th->doff == sizeof(struct tcphdr) >> 2) {
+		tp->rx_opt.saw_tstamp = 0;
+		return 0;
+	} else if (tp->rx_opt.tstamp_ok &&
+		   th->doff == (sizeof(struct tcphdr)>>2)+(TCPOLEN_TSTAMP_ALIGNED>>2)) {
+		if (tcp_parse_aligned_timestamp(tp, th))
+			return 1;
+	}
+	tcp_parse_options(skb, &tp->rx_opt, 1);
+	return 1;
+}
+
+#ifdef CONFIG_TCP_MD5SIG
+/*
+ * Parse MD5 Signature option
+ */
+u8 *tcp_parse_md5sig_option(struct tcphdr *th)
+{
+	int length = (th->doff << 2) - sizeof (*th);
+	u8 *ptr = (u8*)(th + 1);
+
+	/* If the TCP option is too short, we can short cut */
+	if (length < TCPOLEN_MD5SIG)
+		return NULL;
+
+	while (length > 0) {
+		int opcode = *ptr++;
+		int opsize;
+
+		switch(opcode) {
+		case TCPOPT_EOL:
+			return NULL;
+		case TCPOPT_NOP:
+			length--;
+			continue;
+		default:
+			opsize = *ptr++;
+			if (opsize < 2 || opsize > length)
+				return NULL;
+			if (opcode == TCPOPT_MD5SIG)
+				return ptr;
+		}
+		ptr += opsize - 2;
+		length -= opsize;
+	}
+	return NULL;
+}
+#endif
+
+static inline void tcp_store_ts_recent(struct tcp_sock *tp)
+{
+	tp->rx_opt.ts_recent = tp->rx_opt.rcv_tsval;
+	tp->rx_opt.ts_recent_stamp = get_seconds();
+}
+
+static inline void tcp_replace_ts_recent(struct tcp_sock *tp, u32 seq)
+{
+	if (tp->rx_opt.saw_tstamp && !after(seq, tp->rcv_wup)) {
+		/* PAWS bug workaround wrt. ACK frames, the PAWS discard
+		 * extra check below makes sure this can only happen
+		 * for pure ACK frames.  -DaveM
+		 *
+		 * Not only, also it occurs for expired timestamps.
+		 */
+
+		if ((s32)(tp->rx_opt.rcv_tsval - tp->rx_opt.ts_recent) >= 0 ||
+		   get_seconds() >= tp->rx_opt.ts_recent_stamp + TCP_PAWS_24DAYS)
+			tcp_store_ts_recent(tp);
+	}
+}
+
+/* Sorry, PAWS as specified is broken wrt. pure-ACKs -DaveM
+ *
+ * It is not fatal. If this ACK does _not_ change critical state (seqs, window)
+ * it can pass through stack. So, the following predicate verifies that
+ * this segment is not used for anything but congestion avoidance or
+ * fast retransmit. Moreover, we even are able to eliminate most of such
+ * second order effects, if we apply some small "replay" window (~RTO)
+ * to timestamp space.
+ *
+ * All these measures still do not guarantee that we reject wrapped ACKs
+ * on networks with high bandwidth, when sequence space is recycled fastly,
+ * but it guarantees that such events will be very rare and do not affect
+ * connection seriously. This doesn't look nice, but alas, PAWS is really
+ * buggy extension.
+ *
+ * [ Later note. Even worse! It is buggy for segments _with_ data. RFC
+ * states that events when retransmit arrives after original data are rare.
+ * It is a blatant lie. VJ forgot about fast retransmit! 8)8) It is
+ * the biggest problem on large power networks even with minor reordering.
+ * OK, let's give it small replay window. If peer clock is even 1hz, it is safe
+ * up to bandwidth of 18Gigabit/sec. 8) ]
+ */
+
+static int tcp_disordered_ack(const struct sock *sk, const struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcphdr *th = tcp_hdr(skb);
+	u32 seq = TCP_SKB_CB(skb)->seq;
+	u32 ack = TCP_SKB_CB(skb)->ack_seq;
+
+	return (/* 1. Pure ACK with correct sequence number. */
+		(th->ack && seq == TCP_SKB_CB(skb)->end_seq && seq == tp->rcv_nxt) &&
+
+		/* 2. ... and duplicate ACK. */
+		ack == tp->snd_una &&
+
+		/* 3. ... and does not update window. */
+		!tcp_may_update_window(tp, ack, seq, ntohs(th->window) << tp->rx_opt.snd_wscale) &&
+
+		/* 4. ... and sits in replay window. */
+		(s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) <= (inet_csk(sk)->icsk_rto * 1024) / HZ);
+}
+
+static inline int tcp_paws_discard(const struct sock *sk,
+				   const struct sk_buff *skb)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	return ((s32)(tp->rx_opt.ts_recent - tp->rx_opt.rcv_tsval) > TCP_PAWS_WINDOW &&
+		get_seconds() < tp->rx_opt.ts_recent_stamp + TCP_PAWS_24DAYS &&
+		!tcp_disordered_ack(sk, skb));
+}
+
+/* Check segment sequence number for validity.
+ *
+ * Segment controls are considered valid, if the segment
+ * fits to the window after truncation to the window. Acceptability
+ * of data (and SYN, FIN, of course) is checked separately.
+ * See tcp_data_queue(), for example.
+ *
+ * Also, controls (RST is main one) are accepted using RCV.WUP instead
+ * of RCV.NXT. Peer still did not advance his SND.UNA when we
+ * delayed ACK, so that hisSND.UNA<=ourRCV.WUP.
+ * (borrowed from freebsd)
+ */
+
+static inline int tcp_sequence(struct tcp_sock *tp, u32 seq, u32 end_seq)
+{
+	return	!before(end_seq, tp->rcv_wup) &&
+		!after(seq, tp->rcv_nxt + tcp_receive_window(tp));
+}
+
+/* When we get a reset we do this. */
+static void tcp_reset(struct sock *sk)
+{
+	/* We want the right error as BSD sees it (and indeed as we do). */
+	switch (sk->sk_state) {
+	case TCP_SYN_SENT:
+		sk->sk_err = ECONNREFUSED;
+		break;
+	case TCP_CLOSE_WAIT:
+		sk->sk_err = EPIPE;
+		break;
+	case TCP_CLOSE:
+		return;
+	default:
+		sk->sk_err = ECONNRESET;
+	}
+
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk->sk_error_report(sk);
+
+	tcp_done(sk);
+}
+
+/*
+ * 	Process the FIN bit. This now behaves as it is supposed to work
+ *	and the FIN takes effect when it is validly part of sequence
+ *	space. Not before when we get holes.
+ *
+ *	If we are ESTABLISHED, a received fin moves us to CLOSE-WAIT
+ *	(and thence onto LAST-ACK and finally, CLOSE, we never enter
+ *	TIME-WAIT)
+ *
+ *	If we are in FINWAIT-1, a received FIN indicates simultaneous
+ *	close and we go into CLOSING (and later onto TIME-WAIT)
+ *
+ *	If we are in FINWAIT-2, a received FIN moves us to TIME-WAIT.
+ */
+static void tcp_fin(struct sk_buff *skb, struct sock *sk, struct tcphdr *th)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	inet_csk_schedule_ack(sk);
+
+	sk->sk_shutdown |= RCV_SHUTDOWN;
+	sock_set_flag(sk, SOCK_DONE);
+
+	switch (sk->sk_state) {
+	case TCP_SYN_RECV:
+	case TCP_ESTABLISHED:
+		/* Move to CLOSE_WAIT */
+		tcp_set_state(sk, TCP_CLOSE_WAIT);
+		inet_csk(sk)->icsk_ack.pingpong = 1;
+		break;
+
+	case TCP_CLOSE_WAIT:
+	case TCP_CLOSING:
+		/* Received a retransmission of the FIN, do
+		 * nothing.
+		 */
+		break;
+	case TCP_LAST_ACK:
+		/* RFC793: Remain in the LAST-ACK state. */
+		break;
+
+	case TCP_FIN_WAIT1:
+		/* This case occurs when a simultaneous close
+		 * happens, we must ack the received FIN and
+		 * enter the CLOSING state.
+		 */
+		tcp_send_ack(sk);
+		tcp_set_state(sk, TCP_CLOSING);
+		break;
+	case TCP_FIN_WAIT2:
+		/* Received a FIN -- send ACK and enter TIME_WAIT. */
+		tcp_send_ack(sk);
+		tcp_time_wait(sk, TCP_TIME_WAIT, 0);
+		break;
+	default:
+		/* Only TCP_LISTEN and TCP_CLOSE are left, in these
+		 * cases we should never reach this piece of code.
+		 */
+		printk(KERN_ERR "%s: Impossible, sk->sk_state=%d\n",
+		       __func__, sk->sk_state);
+		break;
+	}
+
+	/* It _is_ possible, that we have something out-of-order _after_ FIN.
+	 * Probably, we should reset in this case. For now drop them.
+	 */
+	__skb_queue_purge(&tp->out_of_order_queue);
+	if (tcp_is_sack(tp))
+		tcp_sack_reset(&tp->rx_opt);
+	sk_mem_reclaim(sk);
+
+	if (!sock_flag(sk, SOCK_DEAD)) {
+		sk->sk_state_change(sk);
+
+		/* Do not send POLL_HUP for half duplex close. */
+		if (sk->sk_shutdown == SHUTDOWN_MASK ||
+		    sk->sk_state == TCP_CLOSE)
+			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
+		else
+			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
+	}
+}
+
+static inline int tcp_sack_extend(struct tcp_sack_block *sp, u32 seq,
+				  u32 end_seq)
+{
+	if (!after(seq, sp->end_seq) && !after(sp->start_seq, end_seq)) {
+		if (before(seq, sp->start_seq))
+			sp->start_seq = seq;
+		if (after(end_seq, sp->end_seq))
+			sp->end_seq = end_seq;
+		return 1;
+	}
+	return 0;
+}
+
+static void tcp_dsack_set(struct sock *sk, u32 seq, u32 end_seq)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tcp_is_sack(tp) && sysctl_tcp_dsack) {
+		int mib_idx;
+
+		if (before(seq, tp->rcv_nxt))
+			mib_idx = LINUX_MIB_TCPDSACKOLDSENT;
+		else
+			mib_idx = LINUX_MIB_TCPDSACKOFOSENT;
+
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+
+		tp->rx_opt.dsack = 1;
+		tp->duplicate_sack[0].start_seq = seq;
+		tp->duplicate_sack[0].end_seq = end_seq;
+		tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks + 1;
+	}
+}
+
+static void tcp_dsack_extend(struct sock *sk, u32 seq, u32 end_seq)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!tp->rx_opt.dsack)
+		tcp_dsack_set(sk, seq, end_seq);
+	else
+		tcp_sack_extend(tp->duplicate_sack, seq, end_seq);
+}
+
+static void tcp_send_dupack(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
+	    before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
+		tcp_enter_quickack_mode(sk);
+
+		if (tcp_is_sack(tp) && sysctl_tcp_dsack) {
+			u32 end_seq = TCP_SKB_CB(skb)->end_seq;
+
+			if (after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt))
+				end_seq = tp->rcv_nxt;
+			tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, end_seq);
+		}
+	}
+
+	tcp_send_ack(sk);
+}
+
+/* These routines update the SACK block as out-of-order packets arrive or
+ * in-order packets close up the sequence space.
+ */
+static void tcp_sack_maybe_coalesce(struct tcp_sock *tp)
+{
+	int this_sack;
+	struct tcp_sack_block *sp = &tp->selective_acks[0];
+	struct tcp_sack_block *swalk = sp + 1;
+
+	/* See if the recent change to the first SACK eats into
+	 * or hits the sequence space of other SACK blocks, if so coalesce.
+	 */
+	for (this_sack = 1; this_sack < tp->rx_opt.num_sacks;) {
+		if (tcp_sack_extend(sp, swalk->start_seq, swalk->end_seq)) {
+			int i;
+
+			/* Zap SWALK, by moving every further SACK up by one slot.
+			 * Decrease num_sacks.
+			 */
+			tp->rx_opt.num_sacks--;
+			tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks +
+					       tp->rx_opt.dsack;
+			for (i = this_sack; i < tp->rx_opt.num_sacks; i++)
+				sp[i] = sp[i + 1];
+			continue;
+		}
+		this_sack++, swalk++;
+	}
+}
+
+static inline void tcp_sack_swap(struct tcp_sack_block *sack1,
+				 struct tcp_sack_block *sack2)
+{
+	__u32 tmp;
+
+	tmp = sack1->start_seq;
+	sack1->start_seq = sack2->start_seq;
+	sack2->start_seq = tmp;
+
+	tmp = sack1->end_seq;
+	sack1->end_seq = sack2->end_seq;
+	sack2->end_seq = tmp;
+}
+
+static void tcp_sack_new_ofo_skb(struct sock *sk, u32 seq, u32 end_seq)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_sack_block *sp = &tp->selective_acks[0];
+	int cur_sacks = tp->rx_opt.num_sacks;
+	int this_sack;
+
+	if (!cur_sacks)
+		goto new_sack;
+
+	for (this_sack = 0; this_sack < cur_sacks; this_sack++, sp++) {
+		if (tcp_sack_extend(sp, seq, end_seq)) {
+			/* Rotate this_sack to the first one. */
+			for (; this_sack > 0; this_sack--, sp--)
+				tcp_sack_swap(sp, sp - 1);
+			if (cur_sacks > 1)
+				tcp_sack_maybe_coalesce(tp);
+			return;
+		}
+	}
+
+	/* Could not find an adjacent existing SACK, build a new one,
+	 * put it at the front, and shift everyone else down.  We
+	 * always know there is at least one SACK present already here.
+	 *
+	 * If the sack array is full, forget about the last one.
+	 */
+	if (this_sack >= TCP_NUM_SACKS) {
+		this_sack--;
+		tp->rx_opt.num_sacks--;
+		sp--;
+	}
+	for (; this_sack > 0; this_sack--, sp--)
+		*sp = *(sp - 1);
+
+new_sack:
+	/* Build the new head SACK, and we're done. */
+	sp->start_seq = seq;
+	sp->end_seq = end_seq;
+	tp->rx_opt.num_sacks++;
+	tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack;
+}
+
+/* RCV.NXT advances, some SACKs should be eaten. */
+
+static void tcp_sack_remove(struct tcp_sock *tp)
+{
+	struct tcp_sack_block *sp = &tp->selective_acks[0];
+	int num_sacks = tp->rx_opt.num_sacks;
+	int this_sack;
+
+	/* Empty ofo queue, hence, all the SACKs are eaten. Clear. */
+	if (skb_queue_empty(&tp->out_of_order_queue)) {
+		tp->rx_opt.num_sacks = 0;
+		tp->rx_opt.eff_sacks = tp->rx_opt.dsack;
+		return;
+	}
+
+	for (this_sack = 0; this_sack < num_sacks;) {
+		/* Check if the start of the sack is covered by RCV.NXT. */
+		if (!before(tp->rcv_nxt, sp->start_seq)) {
+			int i;
+
+			/* RCV.NXT must cover all the block! */
+			WARN_ON(before(tp->rcv_nxt, sp->end_seq));
+
+			/* Zap this SACK, by moving forward any other SACKS. */
+			for (i=this_sack+1; i < num_sacks; i++)
+				tp->selective_acks[i-1] = tp->selective_acks[i];
+			num_sacks--;
+			continue;
+		}
+		this_sack++;
+		sp++;
+	}
+	if (num_sacks != tp->rx_opt.num_sacks) {
+		tp->rx_opt.num_sacks = num_sacks;
+		tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks +
+				       tp->rx_opt.dsack;
+	}
+}
+
+/* This one checks to see if we can put data from the
+ * out_of_order queue into the receive_queue.
+ */
+static void tcp_ofo_queue(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	__u32 dsack_high = tp->rcv_nxt;
+	struct sk_buff *skb;
+
+	while ((skb = skb_peek(&tp->out_of_order_queue)) != NULL) {
+		if (after(TCP_SKB_CB(skb)->seq, tp->rcv_nxt))
+			break;
+
+		if (before(TCP_SKB_CB(skb)->seq, dsack_high)) {
+			__u32 dsack = dsack_high;
+			if (before(TCP_SKB_CB(skb)->end_seq, dsack_high))
+				dsack_high = TCP_SKB_CB(skb)->end_seq;
+			tcp_dsack_extend(sk, TCP_SKB_CB(skb)->seq, dsack);
+		}
+
+		if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
+			SOCK_DEBUG(sk, "ofo packet was already received \n");
+			__skb_unlink(skb, &tp->out_of_order_queue);
+			__kfree_skb(skb);
+			continue;
+		}
+		SOCK_DEBUG(sk, "ofo requeuing : rcv_next %X seq %X - %X\n",
+			   tp->rcv_nxt, TCP_SKB_CB(skb)->seq,
+			   TCP_SKB_CB(skb)->end_seq);
+
+		__skb_unlink(skb, &tp->out_of_order_queue);
+		__skb_queue_tail(&sk->sk_receive_queue, skb);
+		tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+		if (tcp_hdr(skb)->fin)
+			tcp_fin(skb, sk, tcp_hdr(skb));
+	}
+}
+
+static int tcp_prune_ofo_queue(struct sock *sk);
+static int tcp_prune_queue(struct sock *sk);
+
+static inline int tcp_try_rmem_schedule(struct sock *sk, unsigned int size)
+{
+	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
+	    !sk_rmem_schedule(sk, size)) {
+
+		if (tcp_prune_queue(sk) < 0)
+			return -1;
+
+		if (!sk_rmem_schedule(sk, size)) {
+			if (!tcp_prune_ofo_queue(sk))
+				return -1;
+
+			if (!sk_rmem_schedule(sk, size))
+				return -1;
+		}
+	}
+	return 0;
+}
+
+static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int eaten = -1;
+
+	if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq)
+		goto drop;
+
+	__skb_pull(skb, th->doff * 4);
+
+	TCP_ECN_accept_cwr(tp, skb);
+
+	if (tp->rx_opt.dsack) {
+		tp->rx_opt.dsack = 0;
+		tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks;
+	}
+
+	/*  Queue data for delivery to the user.
+	 *  Packets in sequence go to the receive queue.
+	 *  Out of sequence packets to the out_of_order_queue.
+	 */
+	if (TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
+		if (tcp_receive_window(tp) == 0)
+			goto out_of_window;
+
+		/* Ok. In sequence. In window. */
+		if (tp->ucopy.task == current &&
+		    tp->copied_seq == tp->rcv_nxt && tp->ucopy.len &&
+		    sock_owned_by_user(sk) && !tp->urg_data) {
+			int chunk = min_t(unsigned int, skb->len,
+					  tp->ucopy.len);
+
+			__set_current_state(TASK_RUNNING);
+
+			local_bh_enable();
+			if (!skb_copy_datagram_iovec(skb, 0, tp->ucopy.iov, chunk)) {
+				tp->ucopy.len -= chunk;
+				tp->copied_seq += chunk;
+				eaten = (chunk == skb->len && !th->fin);
+				tcp_rcv_space_adjust(sk);
+			}
+			local_bh_disable();
+		}
+
+		if (eaten <= 0) {
+queue_and_out:
+			if (eaten < 0 &&
+			    tcp_try_rmem_schedule(sk, skb->truesize))
+				goto drop;
+
+			skb_set_owner_r(skb, sk);
+			__skb_queue_tail(&sk->sk_receive_queue, skb);
+		}
+		tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+		if (skb->len)
+			tcp_event_data_recv(sk, skb);
+		if (th->fin)
+			tcp_fin(skb, sk, th);
+
+		if (!skb_queue_empty(&tp->out_of_order_queue)) {
+			tcp_ofo_queue(sk);
+
+			/* RFC2581. 4.2. SHOULD send immediate ACK, when
+			 * gap in queue is filled.
+			 */
+			if (skb_queue_empty(&tp->out_of_order_queue))
+				inet_csk(sk)->icsk_ack.pingpong = 0;
+		}
+
+		if (tp->rx_opt.num_sacks)
+			tcp_sack_remove(tp);
+
+		tcp_fast_path_check(sk);
+
+		if (eaten > 0)
+			__kfree_skb(skb);
+		else if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_data_ready(sk, 0);
+		return;
+	}
+
+	if (!after(TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt)) {
+		/* A retransmit, 2nd most common case.  Force an immediate ack. */
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOST);
+		tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
+
+out_of_window:
+		tcp_enter_quickack_mode(sk);
+		inet_csk_schedule_ack(sk);
+drop:
+		__kfree_skb(skb);
+		return;
+	}
+
+	/* Out of window. F.e. zero window probe. */
+	if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt + tcp_receive_window(tp)))
+		goto out_of_window;
+
+	tcp_enter_quickack_mode(sk);
+
+	if (before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
+		/* Partial packet, seq < rcv_next < end_seq */
+		SOCK_DEBUG(sk, "partial packet: rcv_next %X seq %X - %X\n",
+			   tp->rcv_nxt, TCP_SKB_CB(skb)->seq,
+			   TCP_SKB_CB(skb)->end_seq);
+
+		tcp_dsack_set(sk, TCP_SKB_CB(skb)->seq, tp->rcv_nxt);
+
+		/* If window is closed, drop tail of packet. But after
+		 * remembering D-SACK for its head made in previous line.
+		 */
+		if (!tcp_receive_window(tp))
+			goto out_of_window;
+		goto queue_and_out;
+	}
+
+	TCP_ECN_check_ce(tp, skb);
+
+	if (tcp_try_rmem_schedule(sk, skb->truesize))
+		goto drop;
+
+	/* Disable header prediction. */
+	tp->pred_flags = 0;
+	inet_csk_schedule_ack(sk);
+
+	SOCK_DEBUG(sk, "out of order segment: rcv_next %X seq %X - %X\n",
+		   tp->rcv_nxt, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq);
+
+	skb_set_owner_r(skb, sk);
+
+	if (!skb_peek(&tp->out_of_order_queue)) {
+		/* Initial out of order segment, build 1 SACK. */
+		if (tcp_is_sack(tp)) {
+			tp->rx_opt.num_sacks = 1;
+			tp->rx_opt.dsack     = 0;
+			tp->rx_opt.eff_sacks = 1;
+			tp->selective_acks[0].start_seq = TCP_SKB_CB(skb)->seq;
+			tp->selective_acks[0].end_seq =
+						TCP_SKB_CB(skb)->end_seq;
+		}
+		__skb_queue_head(&tp->out_of_order_queue, skb);
+	} else {
+		struct sk_buff *skb1 = tp->out_of_order_queue.prev;
+		u32 seq = TCP_SKB_CB(skb)->seq;
+		u32 end_seq = TCP_SKB_CB(skb)->end_seq;
+
+		if (seq == TCP_SKB_CB(skb1)->end_seq) {
+			__skb_queue_after(&tp->out_of_order_queue, skb1, skb);
+
+			if (!tp->rx_opt.num_sacks ||
+			    tp->selective_acks[0].end_seq != seq)
+				goto add_sack;
+
+			/* Common case: data arrive in order after hole. */
+			tp->selective_acks[0].end_seq = end_seq;
+			return;
+		}
+
+		/* Find place to insert this segment. */
+		do {
+			if (!after(TCP_SKB_CB(skb1)->seq, seq))
+				break;
+		} while ((skb1 = skb1->prev) !=
+			 (struct sk_buff *)&tp->out_of_order_queue);
+
+		/* Do skb overlap to previous one? */
+		if (skb1 != (struct sk_buff *)&tp->out_of_order_queue &&
+		    before(seq, TCP_SKB_CB(skb1)->end_seq)) {
+			if (!after(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
+				/* All the bits are present. Drop. */
+				__kfree_skb(skb);
+				tcp_dsack_set(sk, seq, end_seq);
+				goto add_sack;
+			}
+			if (after(seq, TCP_SKB_CB(skb1)->seq)) {
+				/* Partial overlap. */
+				tcp_dsack_set(sk, seq,
+					      TCP_SKB_CB(skb1)->end_seq);
+			} else {
+				skb1 = skb1->prev;
+			}
+		}
+		__skb_queue_after(&tp->out_of_order_queue, skb1, skb);
+
+		/* And clean segments covered by new one as whole. */
+		while ((skb1 = skb->next) !=
+		       (struct sk_buff *)&tp->out_of_order_queue &&
+		       after(end_seq, TCP_SKB_CB(skb1)->seq)) {
+			if (before(end_seq, TCP_SKB_CB(skb1)->end_seq)) {
+				tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
+						 end_seq);
+				break;
+			}
+			__skb_unlink(skb1, &tp->out_of_order_queue);
+			tcp_dsack_extend(sk, TCP_SKB_CB(skb1)->seq,
+					 TCP_SKB_CB(skb1)->end_seq);
+			__kfree_skb(skb1);
+		}
+
+add_sack:
+		if (tcp_is_sack(tp))
+			tcp_sack_new_ofo_skb(sk, seq, end_seq);
+	}
+}
+
+static struct sk_buff *tcp_collapse_one(struct sock *sk, struct sk_buff *skb,
+					struct sk_buff_head *list)
+{
+	struct sk_buff *next = skb->next;
+
+	__skb_unlink(skb, list);
+	__kfree_skb(skb);
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRCVCOLLAPSED);
+
+	return next;
+}
+
+/* Collapse contiguous sequence of skbs head..tail with
+ * sequence numbers start..end.
+ * Segments with FIN/SYN are not collapsed (only because this
+ * simplifies code)
+ */
+static void
+tcp_collapse(struct sock *sk, struct sk_buff_head *list,
+	     struct sk_buff *head, struct sk_buff *tail,
+	     u32 start, u32 end)
+{
+	struct sk_buff *skb;
+
+	/* First, check that queue is collapsible and find
+	 * the point where collapsing can be useful. */
+	for (skb = head; skb != tail;) {
+		/* No new bits? It is possible on ofo queue. */
+		if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
+			skb = tcp_collapse_one(sk, skb, list);
+			continue;
+		}
+
+		/* The first skb to collapse is:
+		 * - not SYN/FIN and
+		 * - bloated or contains data before "start" or
+		 *   overlaps to the next one.
+		 */
+		if (!tcp_hdr(skb)->syn && !tcp_hdr(skb)->fin &&
+		    (tcp_win_from_space(skb->truesize) > skb->len ||
+		     before(TCP_SKB_CB(skb)->seq, start) ||
+		     (skb->next != tail &&
+		      TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb->next)->seq)))
+			break;
+
+		/* Decided to skip this, advance start seq. */
+		start = TCP_SKB_CB(skb)->end_seq;
+		skb = skb->next;
+	}
+	if (skb == tail || tcp_hdr(skb)->syn || tcp_hdr(skb)->fin)
+		return;
+
+	while (before(start, end)) {
+		struct sk_buff *nskb;
+		unsigned int header = skb_headroom(skb);
+		int copy = SKB_MAX_ORDER(header, 0);
+
+		/* Too big header? This can happen with IPv6. */
+		if (copy < 0)
+			return;
+		if (end - start < copy)
+			copy = end - start;
+		nskb = alloc_skb(copy + header, GFP_ATOMIC);
+		if (!nskb)
+			return;
+
+		skb_set_mac_header(nskb, skb_mac_header(skb) - skb->head);
+		skb_set_network_header(nskb, (skb_network_header(skb) -
+					      skb->head));
+		skb_set_transport_header(nskb, (skb_transport_header(skb) -
+						skb->head));
+		skb_reserve(nskb, header);
+		memcpy(nskb->head, skb->head, header);
+		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
+		TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
+		__skb_queue_before(list, skb, nskb);
+		skb_set_owner_r(nskb, sk);
+
+		/* Copy data, releasing collapsed skbs. */
+		while (copy > 0) {
+			int offset = start - TCP_SKB_CB(skb)->seq;
+			int size = TCP_SKB_CB(skb)->end_seq - start;
+
+			BUG_ON(offset < 0);
+			if (size > 0) {
+				size = min(copy, size);
+				if (skb_copy_bits(skb, offset, skb_put(nskb, size), size))
+					BUG();
+				TCP_SKB_CB(nskb)->end_seq += size;
+				copy -= size;
+				start += size;
+			}
+			if (!before(start, TCP_SKB_CB(skb)->end_seq)) {
+				skb = tcp_collapse_one(sk, skb, list);
+				if (skb == tail ||
+				    tcp_hdr(skb)->syn ||
+				    tcp_hdr(skb)->fin)
+					return;
+			}
+		}
+	}
+}
+
+/* Collapse ofo queue. Algorithm: select contiguous sequence of skbs
+ * and tcp_collapse() them until all the queue is collapsed.
+ */
+static void tcp_collapse_ofo_queue(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb = skb_peek(&tp->out_of_order_queue);
+	struct sk_buff *head;
+	u32 start, end;
+
+	if (skb == NULL)
+		return;
+
+	start = TCP_SKB_CB(skb)->seq;
+	end = TCP_SKB_CB(skb)->end_seq;
+	head = skb;
+
+	for (;;) {
+		skb = skb->next;
+
+		/* Segment is terminated when we see gap or when
+		 * we are at the end of all the queue. */
+		if (skb == (struct sk_buff *)&tp->out_of_order_queue ||
+		    after(TCP_SKB_CB(skb)->seq, end) ||
+		    before(TCP_SKB_CB(skb)->end_seq, start)) {
+			tcp_collapse(sk, &tp->out_of_order_queue,
+				     head, skb, start, end);
+			head = skb;
+			if (skb == (struct sk_buff *)&tp->out_of_order_queue)
+				break;
+			/* Start new segment */
+			start = TCP_SKB_CB(skb)->seq;
+			end = TCP_SKB_CB(skb)->end_seq;
+		} else {
+			if (before(TCP_SKB_CB(skb)->seq, start))
+				start = TCP_SKB_CB(skb)->seq;
+			if (after(TCP_SKB_CB(skb)->end_seq, end))
+				end = TCP_SKB_CB(skb)->end_seq;
+		}
+	}
+}
+
+/*
+ * Purge the out-of-order queue.
+ * Return true if queue was pruned.
+ */
+static int tcp_prune_ofo_queue(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int res = 0;
+
+	if (!skb_queue_empty(&tp->out_of_order_queue)) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_OFOPRUNED);
+		__skb_queue_purge(&tp->out_of_order_queue);
+
+		/* Reset SACK state.  A conforming SACK implementation will
+		 * do the same at a timeout based retransmit.  When a connection
+		 * is in a sad state like this, we care only about integrity
+		 * of the connection not performance.
+		 */
+		if (tp->rx_opt.sack_ok)
+			tcp_sack_reset(&tp->rx_opt);
+		sk_mem_reclaim(sk);
+		res = 1;
+	}
+	return res;
+}
+
+/* Reduce allocated memory if we can, trying to get
+ * the socket within its memory limits again.
+ *
+ * Return less than zero if we should start dropping frames
+ * until the socket owning process reads some of the data
+ * to stabilize the situation.
+ */
+static int tcp_prune_queue(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	SOCK_DEBUG(sk, "prune_queue: c=%x\n", tp->copied_seq);
+
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PRUNECALLED);
+
+	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
+		tcp_clamp_window(sk);
+	else if (tcp_memory_pressure)
+		tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
+
+	tcp_collapse_ofo_queue(sk);
+	tcp_collapse(sk, &sk->sk_receive_queue,
+		     sk->sk_receive_queue.next,
+		     (struct sk_buff *)&sk->sk_receive_queue,
+		     tp->copied_seq, tp->rcv_nxt);
+	sk_mem_reclaim(sk);
+
+	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
+		return 0;
+
+	/* Collapsing did not help, destructive actions follow.
+	 * This must not ever occur. */
+
+	tcp_prune_ofo_queue(sk);
+
+	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
+		return 0;
+
+	/* If we are really being abused, tell the caller to silently
+	 * drop receive data on the floor.  It will get retransmitted
+	 * and hopefully then we'll have sufficient space.
+	 */
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_RCVPRUNED);
+
+	/* Massive buffer overcommit. */
+	tp->pred_flags = 0;
+	return -1;
+}
+
+/* RFC2861, slow part. Adjust cwnd, after it was not full during one rto.
+ * As additional protections, we do not touch cwnd in retransmission phases,
+ * and if application hit its sndbuf limit recently.
+ */
+void tcp_cwnd_application_limited(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (inet_csk(sk)->icsk_ca_state == TCP_CA_Open &&
+	    sk->sk_socket && !test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
+		/* Limited by application or receiver window. */
+		u32 init_win = tcp_init_cwnd(tp, __sk_dst_get(sk));
+		u32 win_used = max(tp->snd_cwnd_used, init_win);
+		if (win_used < tp->snd_cwnd) {
+			tp->snd_ssthresh = tcp_current_ssthresh(sk);
+			tp->snd_cwnd = (tp->snd_cwnd + win_used) >> 1;
+		}
+		tp->snd_cwnd_used = 0;
+	}
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+}
+
+static int tcp_should_expand_sndbuf(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* If the user specified a specific send buffer setting, do
+	 * not modify it.
+	 */
+	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
+		return 0;
+
+	/* If we are under global TCP memory pressure, do not expand.  */
+	if (tcp_memory_pressure)
+		return 0;
+
+	/* If we are under soft global TCP memory pressure, do not expand.  */
+	if (atomic_read(&tcp_memory_allocated) >= sysctl_tcp_mem[0])
+		return 0;
+
+	/* If we filled the congestion window, do not expand.  */
+	if (tp->packets_out >= tp->snd_cwnd)
+		return 0;
+
+	return 1;
+}
+
+/* When incoming ACK allowed to free some skb from write_queue,
+ * we remember this event in flag SOCK_QUEUE_SHRUNK and wake up socket
+ * on the exit from tcp input handler.
+ *
+ * PROBLEM: sndbuf expansion does not work well with largesend.
+ */
+static void tcp_new_space(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tcp_should_expand_sndbuf(sk)) {
+		int sndmem = max_t(u32, tp->rx_opt.mss_clamp, tp->mss_cache) +
+			MAX_TCP_HEADER + 16 + sizeof(struct sk_buff);
+		int demanded = max_t(unsigned int, tp->snd_cwnd,
+				     tp->reordering + 1);
+		sndmem *= 2 * demanded;
+		if (sndmem > sk->sk_sndbuf)
+			sk->sk_sndbuf = min(sndmem, sysctl_tcp_wmem[2]);
+		tp->snd_cwnd_stamp = tcp_time_stamp;
+	}
+
+	sk->sk_write_space(sk);
+}
+
+static void tcp_check_space(struct sock *sk)
+{
+	if (sock_flag(sk, SOCK_QUEUE_SHRUNK)) {
+		sock_reset_flag(sk, SOCK_QUEUE_SHRUNK);
+		if (sk->sk_socket &&
+		    test_bit(SOCK_NOSPACE, &sk->sk_socket->flags))
+			tcp_new_space(sk);
+	}
+}
+
+static inline void tcp_data_snd_check(struct sock *sk)
+{
+	tcp_push_pending_frames(sk);
+	tcp_check_space(sk);
+}
+
+/*
+ * Check if sending an ack is needed.
+ */
+static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	    /* More than one full frame received... */
+	if (((tp->rcv_nxt - tp->rcv_wup) > inet_csk(sk)->icsk_ack.rcv_mss
+	     /* ... and right edge of window advances far enough.
+	      * (tcp_recvmsg() will send ACK otherwise). Or...
+	      */
+	     && __tcp_select_window(sk) >= tp->rcv_wnd) ||
+	    /* We ACK each frame or... */
+	    tcp_in_quickack_mode(sk) ||
+	    /* We have out of order data. */
+	    (ofo_possible && skb_peek(&tp->out_of_order_queue))) {
+		/* Then ack it now */
+		tcp_send_ack(sk);
+	} else {
+		/* Else, send delayed ack. */
+		tcp_send_delayed_ack(sk);
+	}
+}
+
+static inline void tcp_ack_snd_check(struct sock *sk)
+{
+	if (!inet_csk_ack_scheduled(sk)) {
+		/* We sent a data segment already. */
+		return;
+	}
+	__tcp_ack_snd_check(sk, 1);
+}
+
+/*
+ *	This routine is only called when we have urgent data
+ *	signaled. Its the 'slow' part of tcp_urg. It could be
+ *	moved inline now as tcp_urg is only called from one
+ *	place. We handle URGent data wrong. We have to - as
+ *	BSD still doesn't use the correction from RFC961.
+ *	For 1003.1g we should support a new option TCP_STDURG to permit
+ *	either form (or just set the sysctl tcp_stdurg).
+ */
+
+static void tcp_check_urg(struct sock *sk, struct tcphdr *th)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 ptr = ntohs(th->urg_ptr);
+
+	if (ptr && !sysctl_tcp_stdurg)
+		ptr--;
+	ptr += ntohl(th->seq);
+
+	/* Ignore urgent data that we've already seen and read. */
+	if (after(tp->copied_seq, ptr))
+		return;
+
+	/* Do not replay urg ptr.
+	 *
+	 * NOTE: interesting situation not covered by specs.
+	 * Misbehaving sender may send urg ptr, pointing to segment,
+	 * which we already have in ofo queue. We are not able to fetch
+	 * such data and will stay in TCP_URG_NOTYET until will be eaten
+	 * by recvmsg(). Seems, we are not obliged to handle such wicked
+	 * situations. But it is worth to think about possibility of some
+	 * DoSes using some hypothetical application level deadlock.
+	 */
+	if (before(ptr, tp->rcv_nxt))
+		return;
+
+	/* Do we already have a newer (or duplicate) urgent pointer? */
+	if (tp->urg_data && !after(ptr, tp->urg_seq))
+		return;
+
+	/* Tell the world about our new urgent pointer. */
+	sk_send_sigurg(sk);
+
+	/* We may be adding urgent data when the last byte read was
+	 * urgent. To do this requires some care. We cannot just ignore
+	 * tp->copied_seq since we would read the last urgent byte again
+	 * as data, nor can we alter copied_seq until this data arrives
+	 * or we break the semantics of SIOCATMARK (and thus sockatmark())
+	 *
+	 * NOTE. Double Dutch. Rendering to plain English: author of comment
+	 * above did something sort of 	send("A", MSG_OOB); send("B", MSG_OOB);
+	 * and expect that both A and B disappear from stream. This is _wrong_.
+	 * Though this happens in BSD with high probability, this is occasional.
+	 * Any application relying on this is buggy. Note also, that fix "works"
+	 * only in this artificial test. Insert some normal data between A and B and we will
+	 * decline of BSD again. Verdict: it is better to remove to trap
+	 * buggy users.
+	 */
+	if (tp->urg_seq == tp->copied_seq && tp->urg_data &&
+	    !sock_flag(sk, SOCK_URGINLINE) && tp->copied_seq != tp->rcv_nxt) {
+		struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
+		tp->copied_seq++;
+		if (skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq)) {
+			__skb_unlink(skb, &sk->sk_receive_queue);
+			__kfree_skb(skb);
+		}
+	}
+
+	tp->urg_data = TCP_URG_NOTYET;
+	tp->urg_seq = ptr;
+
+	/* Disable header prediction. */
+	tp->pred_flags = 0;
+}
+
+/* This is the 'fast' part of urgent handling. */
+static void tcp_urg(struct sock *sk, struct sk_buff *skb, struct tcphdr *th)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* Check if we get a new urgent pointer - normally not. */
+	if (th->urg)
+		tcp_check_urg(sk, th);
+
+	/* Do we wait for any urgent data? - normally not... */
+	if (tp->urg_data == TCP_URG_NOTYET) {
+		u32 ptr = tp->urg_seq - ntohl(th->seq) + (th->doff * 4) -
+			  th->syn;
+
+		/* Is the urgent pointer pointing into this packet? */
+		if (ptr < skb->len) {
+			u8 tmp;
+			if (skb_copy_bits(skb, ptr, &tmp, 1))
+				BUG();
+			tp->urg_data = TCP_URG_VALID | tmp;
+			if (!sock_flag(sk, SOCK_DEAD))
+				sk->sk_data_ready(sk, 0);
+		}
+	}
+}
+
+static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int chunk = skb->len - hlen;
+	int err;
+
+	local_bh_enable();
+	if (skb_csum_unnecessary(skb))
+		err = skb_copy_datagram_iovec(skb, hlen, tp->ucopy.iov, chunk);
+	else
+		err = skb_copy_and_csum_datagram_iovec(skb, hlen,
+						       tp->ucopy.iov);
+
+	if (!err) {
+		tp->ucopy.len -= chunk;
+		tp->copied_seq += chunk;
+		tcp_rcv_space_adjust(sk);
+	}
+
+	local_bh_disable();
+	return err;
+}
+
+static __sum16 __tcp_checksum_complete_user(struct sock *sk,
+					    struct sk_buff *skb)
+{
+	__sum16 result;
+
+	if (sock_owned_by_user(sk)) {
+		local_bh_enable();
+		result = __tcp_checksum_complete(skb);
+		local_bh_disable();
+	} else {
+		result = __tcp_checksum_complete(skb);
+	}
+	return result;
+}
+
+static inline int tcp_checksum_complete_user(struct sock *sk,
+					     struct sk_buff *skb)
+{
+	return !skb_csum_unnecessary(skb) &&
+	       __tcp_checksum_complete_user(sk, skb);
+}
+
+#ifdef CONFIG_NET_DMA
+static int tcp_dma_try_early_copy(struct sock *sk, struct sk_buff *skb,
+				  int hlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int chunk = skb->len - hlen;
+	int dma_cookie;
+	int copied_early = 0;
+
+	if (tp->ucopy.wakeup)
+		return 0;
+
+	if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
+		tp->ucopy.dma_chan = get_softnet_dma();
+
+	if (tp->ucopy.dma_chan && skb_csum_unnecessary(skb)) {
+
+		dma_cookie = dma_skb_copy_datagram_iovec(tp->ucopy.dma_chan,
+							 skb, hlen,
+							 tp->ucopy.iov, chunk,
+							 tp->ucopy.pinned_list);
+
+		if (dma_cookie < 0)
+			goto out;
+
+		tp->ucopy.dma_cookie = dma_cookie;
+		copied_early = 1;
+
+		tp->ucopy.len -= chunk;
+		tp->copied_seq += chunk;
+		tcp_rcv_space_adjust(sk);
+
+		if ((tp->ucopy.len == 0) ||
+		    (tcp_flag_word(tcp_hdr(skb)) & TCP_FLAG_PSH) ||
+		    (atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1))) {
+			tp->ucopy.wakeup = 1;
+			sk->sk_data_ready(sk, 0);
+		}
+	} else if (chunk > 0) {
+		tp->ucopy.wakeup = 1;
+		sk->sk_data_ready(sk, 0);
+	}
+out:
+	return copied_early;
+}
+#endif /* CONFIG_NET_DMA */
+
+/* Does PAWS and seqno based validation of an incoming segment, flags will
+ * play significant role here.
+ */
+static int tcp_validate_incoming(struct sock *sk, struct sk_buff *skb,
+			      struct tcphdr *th, int syn_inerr)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* RFC1323: H1. Apply PAWS check first. */
+	if (tcp_fast_parse_options(skb, th, tp) && tp->rx_opt.saw_tstamp &&
+	    tcp_paws_discard(sk, skb)) {
+		if (!th->rst) {
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED);
+			tcp_send_dupack(sk, skb);
+			goto discard;
+		}
+		/* Reset is accepted even if it did not pass PAWS. */
+	}
+
+	/* Step 1: check sequence number */
+	if (!tcp_sequence(tp, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq)) {
+		/* RFC793, page 37: "In all states except SYN-SENT, all reset
+		 * (RST) segments are validated by checking their SEQ-fields."
+		 * And page 69: "If an incoming segment is not acceptable,
+		 * an acknowledgment should be sent in reply (unless the RST
+		 * bit is set, if so drop the segment and return)".
+		 */
+		if (!th->rst)
+			tcp_send_dupack(sk, skb);
+		goto discard;
+	}
+
+	/* Step 2: check RST bit */
+	if (th->rst) {
+		tcp_reset(sk);
+		goto discard;
+	}
+
+	/* ts_recent update must be made after we are sure that the packet
+	 * is in window.
+	 */
+	tcp_replace_ts_recent(tp, TCP_SKB_CB(skb)->seq);
+
+	/* step 3: check security and precedence [ignored] */
+
+	/* step 4: Check for a SYN in window. */
+	if (th->syn && !before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) {
+		if (syn_inerr)
+			TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONSYN);
+		tcp_reset(sk);
+		return -1;
+	}
+
+	return 1;
+
+discard:
+	__kfree_skb(skb);
+	return 0;
+}
+
+/*
+ *	TCP receive function for the ESTABLISHED state.
+ *
+ *	It is split into a fast path and a slow path. The fast path is
+ * 	disabled when:
+ *	- A zero window was announced from us - zero window probing
+ *        is only handled properly in the slow path.
+ *	- Out of order segments arrived.
+ *	- Urgent data is expected.
+ *	- There is no buffer space left
+ *	- Unexpected TCP flags/window values/header lengths are received
+ *	  (detected by checking the TCP header against pred_flags)
+ *	- Data is sent in both directions. Fast path only supports pure senders
+ *	  or pure receivers (this means either the sequence number or the ack
+ *	  value must stay constant)
+ *	- Unexpected TCP option.
+ *
+ *	When these conditions are not satisfied it drops into a standard
+ *	receive procedure patterned after RFC793 to handle all cases.
+ *	The first three cases are guaranteed by proper pred_flags setting,
+ *	the rest is checked inline. Fast processing is turned on in
+ *	tcp_data_queue when everything is OK.
+ */
+int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
+			struct tcphdr *th, unsigned len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int res;
+
+	/*
+	 *	Header prediction.
+	 *	The code loosely follows the one in the famous
+	 *	"30 instruction TCP receive" Van Jacobson mail.
+	 *
+	 *	Van's trick is to deposit buffers into socket queue
+	 *	on a device interrupt, to call tcp_recv function
+	 *	on the receive process context and checksum and copy
+	 *	the buffer to user space. smart...
+	 *
+	 *	Our current scheme is not silly either but we take the
+	 *	extra cost of the net_bh soft interrupt processing...
+	 *	We do checksum and copy also but from device to kernel.
+	 */
+
+	tp->rx_opt.saw_tstamp = 0;
+
+	/*	pred_flags is 0xS?10 << 16 + snd_wnd
+	 *	if header_prediction is to be made
+	 *	'S' will always be tp->tcp_header_len >> 2
+	 *	'?' will be 0 for the fast path, otherwise pred_flags is 0 to
+	 *  turn it off	(when there are holes in the receive
+	 *	 space for instance)
+	 *	PSH flag is ignored.
+	 */
+
+	if ((tcp_flag_word(th) & TCP_HP_BITS) == tp->pred_flags &&
+	    TCP_SKB_CB(skb)->seq == tp->rcv_nxt) {
+		int tcp_header_len = tp->tcp_header_len;
+
+		/* Timestamp header prediction: tcp_header_len
+		 * is automatically equal to th->doff*4 due to pred_flags
+		 * match.
+		 */
+
+		/* Check timestamp */
+		if (tcp_header_len == sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) {
+			/* No? Slow path! */
+			if (!tcp_parse_aligned_timestamp(tp, th))
+				goto slow_path;
+
+			/* If PAWS failed, check it more carefully in slow path */
+			if ((s32)(tp->rx_opt.rcv_tsval - tp->rx_opt.ts_recent) < 0)
+				goto slow_path;
+
+			/* DO NOT update ts_recent here, if checksum fails
+			 * and timestamp was corrupted part, it will result
+			 * in a hung connection since we will drop all
+			 * future packets due to the PAWS test.
+			 */
+		}
+
+		if (len <= tcp_header_len) {
+			/* Bulk data transfer: sender */
+			if (len == tcp_header_len) {
+				/* Predicted packet is in window by definition.
+				 * seq == rcv_nxt and rcv_wup <= rcv_nxt.
+				 * Hence, check seq<=rcv_wup reduces to:
+				 */
+				if (tcp_header_len ==
+				    (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) &&
+				    tp->rcv_nxt == tp->rcv_wup)
+					tcp_store_ts_recent(tp);
+
+				/* We know that such packets are checksummed
+				 * on entry.
+				 */
+				tcp_ack(sk, skb, 0);
+				__kfree_skb(skb);
+				tcp_data_snd_check(sk);
+				return 0;
+			} else { /* Header too small */
+				TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
+				goto discard;
+			}
+		} else {
+			int eaten = 0;
+			int copied_early = 0;
+
+			if (tp->copied_seq == tp->rcv_nxt &&
+			    len - tcp_header_len <= tp->ucopy.len) {
+#ifdef CONFIG_NET_DMA
+				if (tcp_dma_try_early_copy(sk, skb, tcp_header_len)) {
+					copied_early = 1;
+					eaten = 1;
+				}
+#endif
+				if (tp->ucopy.task == current &&
+				    sock_owned_by_user(sk) && !copied_early) {
+					__set_current_state(TASK_RUNNING);
+
+					if (!tcp_copy_to_iovec(sk, skb, tcp_header_len))
+						eaten = 1;
+				}
+				if (eaten) {
+					/* Predicted packet is in window by definition.
+					 * seq == rcv_nxt and rcv_wup <= rcv_nxt.
+					 * Hence, check seq<=rcv_wup reduces to:
+					 */
+					if (tcp_header_len ==
+					    (sizeof(struct tcphdr) +
+					     TCPOLEN_TSTAMP_ALIGNED) &&
+					    tp->rcv_nxt == tp->rcv_wup)
+						tcp_store_ts_recent(tp);
+
+					tcp_rcv_rtt_measure_ts(sk, skb);
+
+					__skb_pull(skb, tcp_header_len);
+					tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+					NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPHITSTOUSER);
+				}
+				if (copied_early)
+					tcp_cleanup_rbuf(sk, skb->len);
+			}
+			if (!eaten) {
+				if (tcp_checksum_complete_user(sk, skb))
+					goto csum_error;
+
+				/* Predicted packet is in window by definition.
+				 * seq == rcv_nxt and rcv_wup <= rcv_nxt.
+				 * Hence, check seq<=rcv_wup reduces to:
+				 */
+				if (tcp_header_len ==
+				    (sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED) &&
+				    tp->rcv_nxt == tp->rcv_wup)
+					tcp_store_ts_recent(tp);
+
+				tcp_rcv_rtt_measure_ts(sk, skb);
+
+				if ((int)skb->truesize > sk->sk_forward_alloc)
+					goto step5;
+
+				NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPHITS);
+
+				/* Bulk data transfer: receiver */
+				__skb_pull(skb, tcp_header_len);
+				__skb_queue_tail(&sk->sk_receive_queue, skb);
+				skb_set_owner_r(skb, sk);
+				tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+			}
+
+			tcp_event_data_recv(sk, skb);
+
+			if (TCP_SKB_CB(skb)->ack_seq != tp->snd_una) {
+				/* Well, only one small jumplet in fast path... */
+				tcp_ack(sk, skb, FLAG_DATA);
+				tcp_data_snd_check(sk);
+				if (!inet_csk_ack_scheduled(sk))
+					goto no_ack;
+			}
+
+			if (!copied_early || tp->rcv_nxt != tp->rcv_wup)
+				__tcp_ack_snd_check(sk, 0);
+no_ack:
+#ifdef CONFIG_NET_DMA
+			if (copied_early)
+				__skb_queue_tail(&sk->sk_async_wait_queue, skb);
+			else
+#endif
+			if (eaten)
+				__kfree_skb(skb);
+			else
+				sk->sk_data_ready(sk, 0);
+			return 0;
+		}
+	}
+
+slow_path:
+	if (len < (th->doff << 2) || tcp_checksum_complete_user(sk, skb))
+		goto csum_error;
+
+	/*
+	 *	Standard slow path.
+	 */
+
+	res = tcp_validate_incoming(sk, skb, th, 1);
+	if (res <= 0)
+		return -res;
+
+step5:
+	if (th->ack)
+		tcp_ack(sk, skb, FLAG_SLOWPATH);
+
+	tcp_rcv_rtt_measure_ts(sk, skb);
+
+	/* Process urgent data. */
+	tcp_urg(sk, skb, th);
+
+	/* step 7: process the segment text */
+	tcp_data_queue(sk, skb);
+
+	tcp_data_snd_check(sk);
+	tcp_ack_snd_check(sk);
+	return 0;
+
+csum_error:
+	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
+
+discard:
+	__kfree_skb(skb);
+	return 0;
+}
+
+static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
+					 struct tcphdr *th, unsigned len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int saved_clamp = tp->rx_opt.mss_clamp;
+
+	tcp_parse_options(skb, &tp->rx_opt, 0);
+
+	if (th->ack) {
+		/* rfc793:
+		 * "If the state is SYN-SENT then
+		 *    first check the ACK bit
+		 *      If the ACK bit is set
+		 *	  If SEG.ACK =< ISS, or SEG.ACK > SND.NXT, send
+		 *        a reset (unless the RST bit is set, if so drop
+		 *        the segment and return)"
+		 *
+		 *  We do not send data with SYN, so that RFC-correct
+		 *  test reduces to:
+		 */
+		if (TCP_SKB_CB(skb)->ack_seq != tp->snd_nxt)
+			goto reset_and_undo;
+
+		if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr &&
+		    !between(tp->rx_opt.rcv_tsecr, tp->retrans_stamp,
+			     tcp_time_stamp)) {
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSACTIVEREJECTED);
+			goto reset_and_undo;
+		}
+
+		/* Now ACK is acceptable.
+		 *
+		 * "If the RST bit is set
+		 *    If the ACK was acceptable then signal the user "error:
+		 *    connection reset", drop the segment, enter CLOSED state,
+		 *    delete TCB, and return."
+		 */
+
+		if (th->rst) {
+			tcp_reset(sk);
+			goto discard;
+		}
+
+		/* rfc793:
+		 *   "fifth, if neither of the SYN or RST bits is set then
+		 *    drop the segment and return."
+		 *
+		 *    See note below!
+		 *                                        --ANK(990513)
+		 */
+		if (!th->syn)
+			goto discard_and_undo;
+
+		/* rfc793:
+		 *   "If the SYN bit is on ...
+		 *    are acceptable then ...
+		 *    (our SYN has been ACKed), change the connection
+		 *    state to ESTABLISHED..."
+		 */
+
+		TCP_ECN_rcv_synack(tp, th);
+
+		tp->snd_wl1 = TCP_SKB_CB(skb)->seq;
+		tcp_ack(sk, skb, FLAG_SLOWPATH);
+
+		/* Ok.. it's good. Set up sequence numbers and
+		 * move to established.
+		 */
+		tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
+		tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1;
+
+		/* RFC1323: The window in SYN & SYN/ACK segments is
+		 * never scaled.
+		 */
+		tp->snd_wnd = ntohs(th->window);
+		tcp_init_wl(tp, TCP_SKB_CB(skb)->ack_seq, TCP_SKB_CB(skb)->seq);
+
+		if (!tp->rx_opt.wscale_ok) {
+			tp->rx_opt.snd_wscale = tp->rx_opt.rcv_wscale = 0;
+			tp->window_clamp = min(tp->window_clamp, 65535U);
+		}
+
+		if (tp->rx_opt.saw_tstamp) {
+			tp->rx_opt.tstamp_ok	   = 1;
+			tp->tcp_header_len =
+				sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;
+			tp->advmss	    -= TCPOLEN_TSTAMP_ALIGNED;
+			tcp_store_ts_recent(tp);
+		} else {
+			tp->tcp_header_len = sizeof(struct tcphdr);
+		}
+
+		if (tcp_is_sack(tp) && sysctl_tcp_fack)
+			tcp_enable_fack(tp);
+
+		tcp_mtup_init(sk);
+		tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+		tcp_initialize_rcv_mss(sk);
+
+		/* Remember, tcp_poll() does not lock socket!
+		 * Change state from SYN-SENT only after copied_seq
+		 * is initialized. */
+		tp->copied_seq = tp->rcv_nxt;
+		smp_mb();
+		tcp_set_state(sk, TCP_ESTABLISHED);
+
+		security_inet_conn_established(sk, skb);
+
+		/* Make sure socket is routed, for correct metrics.  */
+		icsk->icsk_af_ops->rebuild_header(sk);
+
+		tcp_init_metrics(sk);
+
+		tcp_init_congestion_control(sk);
+
+		/* Prevent spurious tcp_cwnd_restart() on first data
+		 * packet.
+		 */
+		tp->lsndtime = tcp_time_stamp;
+
+		tcp_init_buffer_space(sk);
+
+		if (sock_flag(sk, SOCK_KEEPOPEN))
+			inet_csk_reset_keepalive_timer(sk, keepalive_time_when(tp));
+
+		if (!tp->rx_opt.snd_wscale)
+			__tcp_fast_path_on(tp, tp->snd_wnd);
+		else
+			tp->pred_flags = 0;
+
+		if (!sock_flag(sk, SOCK_DEAD)) {
+			sk->sk_state_change(sk);
+			sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
+		}
+
+		if (sk->sk_write_pending ||
+		    icsk->icsk_accept_queue.rskq_defer_accept ||
+		    icsk->icsk_ack.pingpong) {
+			/* Save one ACK. Data will be ready after
+			 * several ticks, if write_pending is set.
+			 *
+			 * It may be deleted, but with this feature tcpdumps
+			 * look so _wonderfully_ clever, that I was not able
+			 * to stand against the temptation 8)     --ANK
+			 */
+			inet_csk_schedule_ack(sk);
+			icsk->icsk_ack.lrcvtime = tcp_time_stamp;
+			icsk->icsk_ack.ato	 = TCP_ATO_MIN;
+			tcp_incr_quickack(sk);
+			tcp_enter_quickack_mode(sk);
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+						  TCP_DELACK_MAX, TCP_RTO_MAX);
+
+discard:
+			__kfree_skb(skb);
+			return 0;
+		} else {
+			tcp_send_ack(sk);
+		}
+		return -1;
+	}
+
+	/* No ACK in the segment */
+
+	if (th->rst) {
+		/* rfc793:
+		 * "If the RST bit is set
+		 *
+		 *      Otherwise (no ACK) drop the segment and return."
+		 */
+
+		goto discard_and_undo;
+	}
+
+	/* PAWS check. */
+	if (tp->rx_opt.ts_recent_stamp && tp->rx_opt.saw_tstamp &&
+	    tcp_paws_check(&tp->rx_opt, 0))
+		goto discard_and_undo;
+
+	if (th->syn) {
+		/* We see SYN without ACK. It is attempt of
+		 * simultaneous connect with crossed SYNs.
+		 * Particularly, it can be connect to self.
+		 */
+		tcp_set_state(sk, TCP_SYN_RECV);
+
+		if (tp->rx_opt.saw_tstamp) {
+			tp->rx_opt.tstamp_ok = 1;
+			tcp_store_ts_recent(tp);
+			tp->tcp_header_len =
+				sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;
+		} else {
+			tp->tcp_header_len = sizeof(struct tcphdr);
+		}
+
+		tp->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
+		tp->rcv_wup = TCP_SKB_CB(skb)->seq + 1;
+
+		/* RFC1323: The window in SYN & SYN/ACK segments is
+		 * never scaled.
+		 */
+		tp->snd_wnd    = ntohs(th->window);
+		tp->snd_wl1    = TCP_SKB_CB(skb)->seq;
+		tp->max_window = tp->snd_wnd;
+
+		TCP_ECN_rcv_syn(tp, th);
+
+		tcp_mtup_init(sk);
+		tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+		tcp_initialize_rcv_mss(sk);
+
+		tcp_send_synack(sk);
+#if 0
+		/* Note, we could accept data and URG from this segment.
+		 * There are no obstacles to make this.
+		 *
+		 * However, if we ignore data in ACKless segments sometimes,
+		 * we have no reasons to accept it sometimes.
+		 * Also, seems the code doing it in step6 of tcp_rcv_state_process
+		 * is not flawless. So, discard packet for sanity.
+		 * Uncomment this return to process the data.
+		 */
+		return -1;
+#else
+		goto discard;
+#endif
+	}
+	/* "fifth, if neither of the SYN or RST bits is set then
+	 * drop the segment and return."
+	 */
+
+discard_and_undo:
+	tcp_clear_options(&tp->rx_opt);
+	tp->rx_opt.mss_clamp = saved_clamp;
+	goto discard;
+
+reset_and_undo:
+	tcp_clear_options(&tp->rx_opt);
+	tp->rx_opt.mss_clamp = saved_clamp;
+	return 1;
+}
+
+/*
+ *	This function implements the receiving procedure of RFC 793 for
+ *	all states except ESTABLISHED and TIME_WAIT.
+ *	It's called from both tcp_v4_rcv and tcp_v6_rcv and should be
+ *	address independent.
+ */
+
+int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
+			  struct tcphdr *th, unsigned len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int queued = 0;
+	int res;
+
+	tp->rx_opt.saw_tstamp = 0;
+
+	switch (sk->sk_state) {
+	case TCP_CLOSE:
+		goto discard;
+
+	case TCP_LISTEN:
+		if (th->ack)
+			return 1;
+
+		if (th->rst)
+			goto discard;
+
+		if (th->syn) {
+			if (icsk->icsk_af_ops->conn_request(sk, skb) < 0)
+				return 1;
+
+			/* Now we have several options: In theory there is
+			 * nothing else in the frame. KA9Q has an option to
+			 * send data with the syn, BSD accepts data with the
+			 * syn up to the [to be] advertised window and
+			 * Solaris 2.1 gives you a protocol error. For now
+			 * we just ignore it, that fits the spec precisely
+			 * and avoids incompatibilities. It would be nice in
+			 * future to drop through and process the data.
+			 *
+			 * Now that TTCP is starting to be used we ought to
+			 * queue this data.
+			 * But, this leaves one open to an easy denial of
+			 * service attack, and SYN cookies can't defend
+			 * against this problem. So, we drop the data
+			 * in the interest of security over speed unless
+			 * it's still in use.
+			 */
+			kfree_skb(skb);
+			return 0;
+		}
+		goto discard;
+
+	case TCP_SYN_SENT:
+		queued = tcp_rcv_synsent_state_process(sk, skb, th, len);
+		if (queued >= 0)
+			return queued;
+
+		/* Do step6 onward by hand. */
+		tcp_urg(sk, skb, th);
+		__kfree_skb(skb);
+		tcp_data_snd_check(sk);
+		return 0;
+	}
+
+	res = tcp_validate_incoming(sk, skb, th, 0);
+	if (res <= 0)
+		return -res;
+
+	/* step 5: check the ACK field */
+	if (th->ack) {
+		int acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH);
+
+		switch (sk->sk_state) {
+		case TCP_SYN_RECV:
+			if (acceptable) {
+				tp->copied_seq = tp->rcv_nxt;
+				smp_mb();
+				tcp_set_state(sk, TCP_ESTABLISHED);
+				sk->sk_state_change(sk);
+
+				/* Note, that this wakeup is only for marginal
+				 * crossed SYN case. Passively open sockets
+				 * are not waked up, because sk->sk_sleep ==
+				 * NULL and sk->sk_socket == NULL.
+				 */
+				if (sk->sk_socket)
+					sk_wake_async(sk,
+						      SOCK_WAKE_IO, POLL_OUT);
+
+				tp->snd_una = TCP_SKB_CB(skb)->ack_seq;
+				tp->snd_wnd = ntohs(th->window) <<
+					      tp->rx_opt.snd_wscale;
+				tcp_init_wl(tp, TCP_SKB_CB(skb)->ack_seq,
+					    TCP_SKB_CB(skb)->seq);
+
+				/* tcp_ack considers this ACK as duplicate
+				 * and does not calculate rtt.
+				 * Fix it at least with timestamps.
+				 */
+				if (tp->rx_opt.saw_tstamp &&
+				    tp->rx_opt.rcv_tsecr && !tp->srtt)
+					tcp_ack_saw_tstamp(sk, 0);
+
+				if (tp->rx_opt.tstamp_ok)
+					tp->advmss -= TCPOLEN_TSTAMP_ALIGNED;
+
+				/* Make sure socket is routed, for
+				 * correct metrics.
+				 */
+				icsk->icsk_af_ops->rebuild_header(sk);
+
+				tcp_init_metrics(sk);
+
+				tcp_init_congestion_control(sk);
+
+				/* Prevent spurious tcp_cwnd_restart() on
+				 * first data packet.
+				 */
+				tp->lsndtime = tcp_time_stamp;
+
+				tcp_mtup_init(sk);
+				tcp_initialize_rcv_mss(sk);
+				tcp_init_buffer_space(sk);
+				tcp_fast_path_on(tp);
+			} else {
+				return 1;
+			}
+			break;
+
+		case TCP_FIN_WAIT1:
+			if (tp->snd_una == tp->write_seq) {
+				tcp_set_state(sk, TCP_FIN_WAIT2);
+				sk->sk_shutdown |= SEND_SHUTDOWN;
+				dst_confirm(sk->sk_dst_cache);
+
+				if (!sock_flag(sk, SOCK_DEAD))
+					/* Wake up lingering close() */
+					sk->sk_state_change(sk);
+				else {
+					int tmo;
+
+					if (tp->linger2 < 0 ||
+					    (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
+					     after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt))) {
+						tcp_done(sk);
+						NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
+						return 1;
+					}
+
+					tmo = tcp_fin_time(sk);
+					if (tmo > TCP_TIMEWAIT_LEN) {
+						inet_csk_reset_keepalive_timer(sk, tmo - TCP_TIMEWAIT_LEN);
+					} else if (th->fin || sock_owned_by_user(sk)) {
+						/* Bad case. We could lose such FIN otherwise.
+						 * It is not a big problem, but it looks confusing
+						 * and not so rare event. We still can lose it now,
+						 * if it spins in bh_lock_sock(), but it is really
+						 * marginal case.
+						 */
+						inet_csk_reset_keepalive_timer(sk, tmo);
+					} else {
+						tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
+						goto discard;
+					}
+				}
+			}
+			break;
+
+		case TCP_CLOSING:
+			if (tp->snd_una == tp->write_seq) {
+				tcp_time_wait(sk, TCP_TIME_WAIT, 0);
+				goto discard;
+			}
+			break;
+
+		case TCP_LAST_ACK:
+			if (tp->snd_una == tp->write_seq) {
+				tcp_update_metrics(sk);
+				tcp_done(sk);
+				goto discard;
+			}
+			break;
+		}
+	} else
+		goto discard;
+
+	/* step 6: check the URG bit */
+	tcp_urg(sk, skb, th);
+
+	/* step 7: process the segment text */
+	switch (sk->sk_state) {
+	case TCP_CLOSE_WAIT:
+	case TCP_CLOSING:
+	case TCP_LAST_ACK:
+		if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt))
+			break;
+	case TCP_FIN_WAIT1:
+	case TCP_FIN_WAIT2:
+		/* RFC 793 says to queue data in these states,
+		 * RFC 1122 says we MUST send a reset.
+		 * BSD 4.4 also does reset.
+		 */
+		if (sk->sk_shutdown & RCV_SHUTDOWN) {
+			if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
+			    after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) {
+				NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
+				tcp_reset(sk);
+				return 1;
+			}
+		}
+		/* Fall through */
+	case TCP_ESTABLISHED:
+		tcp_data_queue(sk, skb);
+		queued = 1;
+		break;
+	}
+
+	/* tcp_data could move socket to TIME-WAIT */
+	if (sk->sk_state != TCP_CLOSE) {
+		tcp_data_snd_check(sk);
+		tcp_ack_snd_check(sk);
+	}
+
+	if (!queued) {
+discard:
+		__kfree_skb(skb);
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(sysctl_tcp_ecn);
+EXPORT_SYMBOL(sysctl_tcp_reordering);
+EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
+EXPORT_SYMBOL(tcp_parse_options);
+#ifdef CONFIG_TCP_MD5SIG
+EXPORT_SYMBOL(tcp_parse_md5sig_option);
+#endif
+EXPORT_SYMBOL(tcp_rcv_established);
+EXPORT_SYMBOL(tcp_rcv_state_process);
+EXPORT_SYMBOL(tcp_initialize_rcv_mss);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
new file mode 100644
index 0000000..5c8fa7f
--- /dev/null
+++ b/net/ipv4/tcp_ipv4.c
@@ -0,0 +1,2429 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ *		IPv4 specific functions
+ *
+ *
+ *		code split from:
+ *		linux/ipv4/tcp.c
+ *		linux/ipv4/tcp_input.c
+ *		linux/ipv4/tcp_output.c
+ *
+ *		See tcp.c for author information
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+/*
+ * Changes:
+ *		David S. Miller	:	New socket lookup architecture.
+ *					This code is dedicated to John Dyson.
+ *		David S. Miller :	Change semantics of established hash,
+ *					half is devoted to TIME_WAIT sockets
+ *					and the rest go in the other half.
+ *		Andi Kleen :		Add support for syncookies and fixed
+ *					some bugs: ip options weren't passed to
+ *					the TCP layer, missed a check for an
+ *					ACK bit.
+ *		Andi Kleen :		Implemented fast path mtu discovery.
+ *	     				Fixed many serious bugs in the
+ *					request_sock handling and moved
+ *					most of it into the af independent code.
+ *					Added tail drop and some other bugfixes.
+ *					Added new listen semantics.
+ *		Mike McLagan	:	Routing by source
+ *	Juan Jose Ciarlante:		ip_dynaddr bits
+ *		Andi Kleen:		various fixes.
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year
+ *					coma.
+ *	Andi Kleen		:	Fix new listen.
+ *	Andi Kleen		:	Fix accept error reporting.
+ *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
+ *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
+ *					a single port at the same time.
+ */
+
+
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/cache.h>
+#include <linux/jhash.h>
+#include <linux/init.h>
+#include <linux/times.h>
+
+#include <net/net_namespace.h>
+#include <net/icmp.h>
+#include <net/inet_hashtables.h>
+#include <net/tcp.h>
+#include <net/transp_v6.h>
+#include <net/ipv6.h>
+#include <net/inet_common.h>
+#include <net/timewait_sock.h>
+#include <net/xfrm.h>
+#include <net/netdma.h>
+
+#include <linux/inet.h>
+#include <linux/ipv6.h>
+#include <linux/stddef.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+
+int sysctl_tcp_tw_reuse __read_mostly;
+int sysctl_tcp_low_latency __read_mostly;
+
+
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
+						   __be32 addr);
+static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
+			       __be32 daddr, __be32 saddr, struct tcphdr *th);
+#else
+static inline
+struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
+{
+	return NULL;
+}
+#endif
+
+struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
+	.lhash_lock  = __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock),
+	.lhash_users = ATOMIC_INIT(0),
+	.lhash_wait  = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait),
+};
+
+static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
+{
+	return secure_tcp_sequence_number(ip_hdr(skb)->daddr,
+					  ip_hdr(skb)->saddr,
+					  tcp_hdr(skb)->dest,
+					  tcp_hdr(skb)->source);
+}
+
+int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
+{
+	const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* With PAWS, it is safe from the viewpoint
+	   of data integrity. Even without PAWS it is safe provided sequence
+	   spaces do not overlap i.e. at data rates <= 80Mbit/sec.
+
+	   Actually, the idea is close to VJ's one, only timestamp cache is
+	   held not per host, but per port pair and TW bucket is used as state
+	   holder.
+
+	   If TW bucket has been already destroyed we fall back to VJ's scheme
+	   and use initial timestamp retrieved from peer table.
+	 */
+	if (tcptw->tw_ts_recent_stamp &&
+	    (twp == NULL || (sysctl_tcp_tw_reuse &&
+			     get_seconds() - tcptw->tw_ts_recent_stamp > 1))) {
+		tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
+		if (tp->write_seq == 0)
+			tp->write_seq = 1;
+		tp->rx_opt.ts_recent	   = tcptw->tw_ts_recent;
+		tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
+		sock_hold(sktw);
+		return 1;
+	}
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(tcp_twsk_unique);
+
+/* This will initiate an outgoing connection. */
+int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
+	struct rtable *rt;
+	__be32 daddr, nexthop;
+	int tmp;
+	int err;
+
+	if (addr_len < sizeof(struct sockaddr_in))
+		return -EINVAL;
+
+	if (usin->sin_family != AF_INET)
+		return -EAFNOSUPPORT;
+
+	nexthop = daddr = usin->sin_addr.s_addr;
+	if (inet->opt && inet->opt->srr) {
+		if (!daddr)
+			return -EINVAL;
+		nexthop = inet->opt->faddr;
+	}
+
+	tmp = ip_route_connect(&rt, nexthop, inet->saddr,
+			       RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
+			       IPPROTO_TCP,
+			       inet->sport, usin->sin_port, sk, 1);
+	if (tmp < 0) {
+		if (tmp == -ENETUNREACH)
+			IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+		return tmp;
+	}
+
+	if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
+		ip_rt_put(rt);
+		return -ENETUNREACH;
+	}
+
+	if (!inet->opt || !inet->opt->srr)
+		daddr = rt->rt_dst;
+
+	if (!inet->saddr)
+		inet->saddr = rt->rt_src;
+	inet->rcv_saddr = inet->saddr;
+
+	if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) {
+		/* Reset inherited state */
+		tp->rx_opt.ts_recent	   = 0;
+		tp->rx_opt.ts_recent_stamp = 0;
+		tp->write_seq		   = 0;
+	}
+
+	if (tcp_death_row.sysctl_tw_recycle &&
+	    !tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
+		struct inet_peer *peer = rt_get_peer(rt);
+		/*
+		 * VJ's idea. We save last timestamp seen from
+		 * the destination in peer table, when entering state
+		 * TIME-WAIT * and initialize rx_opt.ts_recent from it,
+		 * when trying new connection.
+		 */
+		if (peer != NULL &&
+		    peer->tcp_ts_stamp + TCP_PAWS_MSL >= get_seconds()) {
+			tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
+			tp->rx_opt.ts_recent = peer->tcp_ts;
+		}
+	}
+
+	inet->dport = usin->sin_port;
+	inet->daddr = daddr;
+
+	inet_csk(sk)->icsk_ext_hdr_len = 0;
+	if (inet->opt)
+		inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
+
+	tp->rx_opt.mss_clamp = 536;
+
+	/* Socket identity is still unknown (sport may be zero).
+	 * However we set state to SYN-SENT and not releasing socket
+	 * lock select source port, enter ourselves into the hash tables and
+	 * complete initialization after this.
+	 */
+	tcp_set_state(sk, TCP_SYN_SENT);
+	err = inet_hash_connect(&tcp_death_row, sk);
+	if (err)
+		goto failure;
+
+	err = ip_route_newports(&rt, IPPROTO_TCP,
+				inet->sport, inet->dport, sk);
+	if (err)
+		goto failure;
+
+	/* OK, now commit destination to socket.  */
+	sk->sk_gso_type = SKB_GSO_TCPV4;
+	sk_setup_caps(sk, &rt->u.dst);
+
+	if (!tp->write_seq)
+		tp->write_seq = secure_tcp_sequence_number(inet->saddr,
+							   inet->daddr,
+							   inet->sport,
+							   usin->sin_port);
+
+	inet->id = tp->write_seq ^ jiffies;
+
+	err = tcp_connect(sk);
+	rt = NULL;
+	if (err)
+		goto failure;
+
+	return 0;
+
+failure:
+	/*
+	 * This unhashes the socket and releases the local port,
+	 * if necessary.
+	 */
+	tcp_set_state(sk, TCP_CLOSE);
+	ip_rt_put(rt);
+	sk->sk_route_caps = 0;
+	inet->dport = 0;
+	return err;
+}
+
+/*
+ * This routine does path mtu discovery as defined in RFC1191.
+ */
+static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu)
+{
+	struct dst_entry *dst;
+	struct inet_sock *inet = inet_sk(sk);
+
+	/* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
+	 * send out by Linux are always <576bytes so they should go through
+	 * unfragmented).
+	 */
+	if (sk->sk_state == TCP_LISTEN)
+		return;
+
+	/* We don't check in the destentry if pmtu discovery is forbidden
+	 * on this route. We just assume that no packet_to_big packets
+	 * are send back when pmtu discovery is not active.
+	 * There is a small race when the user changes this flag in the
+	 * route, but I think that's acceptable.
+	 */
+	if ((dst = __sk_dst_check(sk, 0)) == NULL)
+		return;
+
+	dst->ops->update_pmtu(dst, mtu);
+
+	/* Something is about to be wrong... Remember soft error
+	 * for the case, if this connection will not able to recover.
+	 */
+	if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
+		sk->sk_err_soft = EMSGSIZE;
+
+	mtu = dst_mtu(dst);
+
+	if (inet->pmtudisc != IP_PMTUDISC_DONT &&
+	    inet_csk(sk)->icsk_pmtu_cookie > mtu) {
+		tcp_sync_mss(sk, mtu);
+
+		/* Resend the TCP packet because it's
+		 * clear that the old packet has been
+		 * dropped. This is the new "fast" path mtu
+		 * discovery.
+		 */
+		tcp_simple_retransmit(sk);
+	} /* else let the usual retransmit timer handle it */
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.  If err < 0 then the socket should
+ * be closed and the error returned to the user.  If err > 0
+ * it's just the icmp type << 8 | icmp code.  After adjustment
+ * header points to the first 8 bytes of the tcp header.  We need
+ * to find the appropriate port.
+ *
+ * The locking strategy used here is very "optimistic". When
+ * someone else accesses the socket the ICMP is just dropped
+ * and for some paths there is no check at all.
+ * A more general error queue to queue errors for later handling
+ * is probably better.
+ *
+ */
+
+void tcp_v4_err(struct sk_buff *skb, u32 info)
+{
+	struct iphdr *iph = (struct iphdr *)skb->data;
+	struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2));
+	struct tcp_sock *tp;
+	struct inet_sock *inet;
+	const int type = icmp_hdr(skb)->type;
+	const int code = icmp_hdr(skb)->code;
+	struct sock *sk;
+	__u32 seq;
+	int err;
+	struct net *net = dev_net(skb->dev);
+
+	if (skb->len < (iph->ihl << 2) + 8) {
+		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
+		return;
+	}
+
+	sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
+			iph->saddr, th->source, inet_iif(skb));
+	if (!sk) {
+		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
+		return;
+	}
+	if (sk->sk_state == TCP_TIME_WAIT) {
+		inet_twsk_put(inet_twsk(sk));
+		return;
+	}
+
+	bh_lock_sock(sk);
+	/* If too many ICMPs get dropped on busy
+	 * servers this needs to be solved differently.
+	 */
+	if (sock_owned_by_user(sk))
+		NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS);
+
+	if (sk->sk_state == TCP_CLOSE)
+		goto out;
+
+	tp = tcp_sk(sk);
+	seq = ntohl(th->seq);
+	if (sk->sk_state != TCP_LISTEN &&
+	    !between(seq, tp->snd_una, tp->snd_nxt)) {
+		NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
+		goto out;
+	}
+
+	switch (type) {
+	case ICMP_SOURCE_QUENCH:
+		/* Just silently ignore these. */
+		goto out;
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		break;
+	case ICMP_DEST_UNREACH:
+		if (code > NR_ICMP_UNREACH)
+			goto out;
+
+		if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
+			if (!sock_owned_by_user(sk))
+				do_pmtu_discovery(sk, iph, info);
+			goto out;
+		}
+
+		err = icmp_err_convert[code].errno;
+		break;
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	default:
+		goto out;
+	}
+
+	switch (sk->sk_state) {
+		struct request_sock *req, **prev;
+	case TCP_LISTEN:
+		if (sock_owned_by_user(sk))
+			goto out;
+
+		req = inet_csk_search_req(sk, &prev, th->dest,
+					  iph->daddr, iph->saddr);
+		if (!req)
+			goto out;
+
+		/* ICMPs are not backlogged, hence we cannot get
+		   an established socket here.
+		 */
+		WARN_ON(req->sk);
+
+		if (seq != tcp_rsk(req)->snt_isn) {
+			NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
+			goto out;
+		}
+
+		/*
+		 * Still in SYN_RECV, just remove it silently.
+		 * There is no good way to pass the error to the newly
+		 * created socket, and POSIX does not want network
+		 * errors returned from accept().
+		 */
+		inet_csk_reqsk_queue_drop(sk, req, prev);
+		goto out;
+
+	case TCP_SYN_SENT:
+	case TCP_SYN_RECV:  /* Cannot happen.
+			       It can f.e. if SYNs crossed.
+			     */
+		if (!sock_owned_by_user(sk)) {
+			sk->sk_err = err;
+
+			sk->sk_error_report(sk);
+
+			tcp_done(sk);
+		} else {
+			sk->sk_err_soft = err;
+		}
+		goto out;
+	}
+
+	/* If we've already connected we will keep trying
+	 * until we time out, or the user gives up.
+	 *
+	 * rfc1122 4.2.3.9 allows to consider as hard errors
+	 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
+	 * but it is obsoleted by pmtu discovery).
+	 *
+	 * Note, that in modern internet, where routing is unreliable
+	 * and in each dark corner broken firewalls sit, sending random
+	 * errors ordered by their masters even this two messages finally lose
+	 * their original sense (even Linux sends invalid PORT_UNREACHs)
+	 *
+	 * Now we are in compliance with RFCs.
+	 *							--ANK (980905)
+	 */
+
+	inet = inet_sk(sk);
+	if (!sock_owned_by_user(sk) && inet->recverr) {
+		sk->sk_err = err;
+		sk->sk_error_report(sk);
+	} else	{ /* Only an error on timeout */
+		sk->sk_err_soft = err;
+	}
+
+out:
+	bh_unlock_sock(sk);
+	sock_put(sk);
+}
+
+/* This routine computes an IPv4 TCP checksum. */
+void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct tcphdr *th = tcp_hdr(skb);
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		th->check = ~tcp_v4_check(len, inet->saddr,
+					  inet->daddr, 0);
+		skb->csum_start = skb_transport_header(skb) - skb->head;
+		skb->csum_offset = offsetof(struct tcphdr, check);
+	} else {
+		th->check = tcp_v4_check(len, inet->saddr, inet->daddr,
+					 csum_partial((char *)th,
+						      th->doff << 2,
+						      skb->csum));
+	}
+}
+
+int tcp_v4_gso_send_check(struct sk_buff *skb)
+{
+	const struct iphdr *iph;
+	struct tcphdr *th;
+
+	if (!pskb_may_pull(skb, sizeof(*th)))
+		return -EINVAL;
+
+	iph = ip_hdr(skb);
+	th = tcp_hdr(skb);
+
+	th->check = 0;
+	th->check = ~tcp_v4_check(skb->len, iph->saddr, iph->daddr, 0);
+	skb->csum_start = skb_transport_header(skb) - skb->head;
+	skb->csum_offset = offsetof(struct tcphdr, check);
+	skb->ip_summed = CHECKSUM_PARTIAL;
+	return 0;
+}
+
+/*
+ *	This routine will send an RST to the other tcp.
+ *
+ *	Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
+ *		      for reset.
+ *	Answer: if a packet caused RST, it is not for a socket
+ *		existing in our system, if it is matched to a socket,
+ *		it is just duplicate segment or bug in other side's TCP.
+ *		So that we build reply only basing on parameters
+ *		arrived with segment.
+ *	Exception: precedence violation. We do not implement it in any case.
+ */
+
+static void tcp_v4_send_reset(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+	struct {
+		struct tcphdr th;
+#ifdef CONFIG_TCP_MD5SIG
+		__be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
+#endif
+	} rep;
+	struct ip_reply_arg arg;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key *key;
+#endif
+	struct net *net;
+
+	/* Never send a reset in response to a reset. */
+	if (th->rst)
+		return;
+
+	if (skb->rtable->rt_type != RTN_LOCAL)
+		return;
+
+	/* Swap the send and the receive. */
+	memset(&rep, 0, sizeof(rep));
+	rep.th.dest   = th->source;
+	rep.th.source = th->dest;
+	rep.th.doff   = sizeof(struct tcphdr) / 4;
+	rep.th.rst    = 1;
+
+	if (th->ack) {
+		rep.th.seq = th->ack_seq;
+	} else {
+		rep.th.ack = 1;
+		rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
+				       skb->len - (th->doff << 2));
+	}
+
+	memset(&arg, 0, sizeof(arg));
+	arg.iov[0].iov_base = (unsigned char *)&rep;
+	arg.iov[0].iov_len  = sizeof(rep.th);
+
+#ifdef CONFIG_TCP_MD5SIG
+	key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr) : NULL;
+	if (key) {
+		rep.opt[0] = htonl((TCPOPT_NOP << 24) |
+				   (TCPOPT_NOP << 16) |
+				   (TCPOPT_MD5SIG << 8) |
+				   TCPOLEN_MD5SIG);
+		/* Update length and the length the header thinks exists */
+		arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
+		rep.th.doff = arg.iov[0].iov_len / 4;
+
+		tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1],
+				     key, ip_hdr(skb)->saddr,
+				     ip_hdr(skb)->daddr, &rep.th);
+	}
+#endif
+	arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
+				      ip_hdr(skb)->saddr, /* XXX */
+				      arg.iov[0].iov_len, IPPROTO_TCP, 0);
+	arg.csumoffset = offsetof(struct tcphdr, check) / 2;
+	arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
+
+	net = dev_net(skb->dst->dev);
+	ip_send_reply(net->ipv4.tcp_sock, skb,
+		      &arg, arg.iov[0].iov_len);
+
+	TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
+	TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS);
+}
+
+/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
+   outside socket context is ugly, certainly. What can I do?
+ */
+
+static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack,
+			    u32 win, u32 ts, int oif,
+			    struct tcp_md5sig_key *key,
+			    int reply_flags)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+	struct {
+		struct tcphdr th;
+		__be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
+#ifdef CONFIG_TCP_MD5SIG
+			   + (TCPOLEN_MD5SIG_ALIGNED >> 2)
+#endif
+			];
+	} rep;
+	struct ip_reply_arg arg;
+	struct net *net = dev_net(skb->dst->dev);
+
+	memset(&rep.th, 0, sizeof(struct tcphdr));
+	memset(&arg, 0, sizeof(arg));
+
+	arg.iov[0].iov_base = (unsigned char *)&rep;
+	arg.iov[0].iov_len  = sizeof(rep.th);
+	if (ts) {
+		rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+				   (TCPOPT_TIMESTAMP << 8) |
+				   TCPOLEN_TIMESTAMP);
+		rep.opt[1] = htonl(tcp_time_stamp);
+		rep.opt[2] = htonl(ts);
+		arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED;
+	}
+
+	/* Swap the send and the receive. */
+	rep.th.dest    = th->source;
+	rep.th.source  = th->dest;
+	rep.th.doff    = arg.iov[0].iov_len / 4;
+	rep.th.seq     = htonl(seq);
+	rep.th.ack_seq = htonl(ack);
+	rep.th.ack     = 1;
+	rep.th.window  = htons(win);
+
+#ifdef CONFIG_TCP_MD5SIG
+	if (key) {
+		int offset = (ts) ? 3 : 0;
+
+		rep.opt[offset++] = htonl((TCPOPT_NOP << 24) |
+					  (TCPOPT_NOP << 16) |
+					  (TCPOPT_MD5SIG << 8) |
+					  TCPOLEN_MD5SIG);
+		arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED;
+		rep.th.doff = arg.iov[0].iov_len/4;
+
+		tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset],
+				    key, ip_hdr(skb)->saddr,
+				    ip_hdr(skb)->daddr, &rep.th);
+	}
+#endif
+	arg.flags = reply_flags;
+	arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
+				      ip_hdr(skb)->saddr, /* XXX */
+				      arg.iov[0].iov_len, IPPROTO_TCP, 0);
+	arg.csumoffset = offsetof(struct tcphdr, check) / 2;
+	if (oif)
+		arg.bound_dev_if = oif;
+
+	ip_send_reply(net->ipv4.tcp_sock, skb,
+		      &arg, arg.iov[0].iov_len);
+
+	TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
+}
+
+static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
+{
+	struct inet_timewait_sock *tw = inet_twsk(sk);
+	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+
+	tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
+			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
+			tcptw->tw_ts_recent,
+			tw->tw_bound_dev_if,
+			tcp_twsk_md5_key(tcptw),
+			tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0
+			);
+
+	inet_twsk_put(tw);
+}
+
+static void tcp_v4_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
+				  struct request_sock *req)
+{
+	tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1,
+			tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
+			req->ts_recent,
+			0,
+			tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr),
+			inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0);
+}
+
+/*
+ *	Send a SYN-ACK after having received a SYN.
+ *	This still operates on a request_sock only, not on a big
+ *	socket.
+ */
+static int __tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
+				struct dst_entry *dst)
+{
+	const struct inet_request_sock *ireq = inet_rsk(req);
+	int err = -1;
+	struct sk_buff * skb;
+
+	/* First, grab a route. */
+	if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
+		return -1;
+
+	skb = tcp_make_synack(sk, dst, req);
+
+	if (skb) {
+		struct tcphdr *th = tcp_hdr(skb);
+
+		th->check = tcp_v4_check(skb->len,
+					 ireq->loc_addr,
+					 ireq->rmt_addr,
+					 csum_partial((char *)th, skb->len,
+						      skb->csum));
+
+		err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
+					    ireq->rmt_addr,
+					    ireq->opt);
+		err = net_xmit_eval(err);
+	}
+
+	dst_release(dst);
+	return err;
+}
+
+static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req)
+{
+	return __tcp_v4_send_synack(sk, req, NULL);
+}
+
+/*
+ *	IPv4 request_sock destructor.
+ */
+static void tcp_v4_reqsk_destructor(struct request_sock *req)
+{
+	kfree(inet_rsk(req)->opt);
+}
+
+#ifdef CONFIG_SYN_COOKIES
+static void syn_flood_warning(struct sk_buff *skb)
+{
+	static unsigned long warntime;
+
+	if (time_after(jiffies, (warntime + HZ * 60))) {
+		warntime = jiffies;
+		printk(KERN_INFO
+		       "possible SYN flooding on port %d. Sending cookies.\n",
+		       ntohs(tcp_hdr(skb)->dest));
+	}
+}
+#endif
+
+/*
+ * Save and compile IPv4 options into the request_sock if needed.
+ */
+static struct ip_options *tcp_v4_save_options(struct sock *sk,
+					      struct sk_buff *skb)
+{
+	struct ip_options *opt = &(IPCB(skb)->opt);
+	struct ip_options *dopt = NULL;
+
+	if (opt && opt->optlen) {
+		int opt_size = optlength(opt);
+		dopt = kmalloc(opt_size, GFP_ATOMIC);
+		if (dopt) {
+			if (ip_options_echo(dopt, skb)) {
+				kfree(dopt);
+				dopt = NULL;
+			}
+		}
+	}
+	return dopt;
+}
+
+#ifdef CONFIG_TCP_MD5SIG
+/*
+ * RFC2385 MD5 checksumming requires a mapping of
+ * IP address->MD5 Key.
+ * We need to maintain these in the sk structure.
+ */
+
+/* Find the Key structure for an address.  */
+static struct tcp_md5sig_key *
+			tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int i;
+
+	if (!tp->md5sig_info || !tp->md5sig_info->entries4)
+		return NULL;
+	for (i = 0; i < tp->md5sig_info->entries4; i++) {
+		if (tp->md5sig_info->keys4[i].addr == addr)
+			return &tp->md5sig_info->keys4[i].base;
+	}
+	return NULL;
+}
+
+struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
+					 struct sock *addr_sk)
+{
+	return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->daddr);
+}
+
+EXPORT_SYMBOL(tcp_v4_md5_lookup);
+
+static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
+						      struct request_sock *req)
+{
+	return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
+}
+
+/* This can be called on a newly created socket, from other files */
+int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
+		      u8 *newkey, u8 newkeylen)
+{
+	/* Add Key to the list */
+	struct tcp_md5sig_key *key;
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp4_md5sig_key *keys;
+
+	key = tcp_v4_md5_do_lookup(sk, addr);
+	if (key) {
+		/* Pre-existing entry - just update that one. */
+		kfree(key->key);
+		key->key = newkey;
+		key->keylen = newkeylen;
+	} else {
+		struct tcp_md5sig_info *md5sig;
+
+		if (!tp->md5sig_info) {
+			tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
+						  GFP_ATOMIC);
+			if (!tp->md5sig_info) {
+				kfree(newkey);
+				return -ENOMEM;
+			}
+			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+		}
+		if (tcp_alloc_md5sig_pool() == NULL) {
+			kfree(newkey);
+			return -ENOMEM;
+		}
+		md5sig = tp->md5sig_info;
+
+		if (md5sig->alloced4 == md5sig->entries4) {
+			keys = kmalloc((sizeof(*keys) *
+					(md5sig->entries4 + 1)), GFP_ATOMIC);
+			if (!keys) {
+				kfree(newkey);
+				tcp_free_md5sig_pool();
+				return -ENOMEM;
+			}
+
+			if (md5sig->entries4)
+				memcpy(keys, md5sig->keys4,
+				       sizeof(*keys) * md5sig->entries4);
+
+			/* Free old key list, and reference new one */
+			kfree(md5sig->keys4);
+			md5sig->keys4 = keys;
+			md5sig->alloced4++;
+		}
+		md5sig->entries4++;
+		md5sig->keys4[md5sig->entries4 - 1].addr        = addr;
+		md5sig->keys4[md5sig->entries4 - 1].base.key    = newkey;
+		md5sig->keys4[md5sig->entries4 - 1].base.keylen = newkeylen;
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(tcp_v4_md5_do_add);
+
+static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
+			       u8 *newkey, u8 newkeylen)
+{
+	return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->daddr,
+				 newkey, newkeylen);
+}
+
+int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int i;
+
+	for (i = 0; i < tp->md5sig_info->entries4; i++) {
+		if (tp->md5sig_info->keys4[i].addr == addr) {
+			/* Free the key */
+			kfree(tp->md5sig_info->keys4[i].base.key);
+			tp->md5sig_info->entries4--;
+
+			if (tp->md5sig_info->entries4 == 0) {
+				kfree(tp->md5sig_info->keys4);
+				tp->md5sig_info->keys4 = NULL;
+				tp->md5sig_info->alloced4 = 0;
+			} else if (tp->md5sig_info->entries4 != i) {
+				/* Need to do some manipulation */
+				memmove(&tp->md5sig_info->keys4[i],
+					&tp->md5sig_info->keys4[i+1],
+					(tp->md5sig_info->entries4 - i) *
+					 sizeof(struct tcp4_md5sig_key));
+			}
+			tcp_free_md5sig_pool();
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+EXPORT_SYMBOL(tcp_v4_md5_do_del);
+
+static void tcp_v4_clear_md5_list(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* Free each key, then the set of key keys,
+	 * the crypto element, and then decrement our
+	 * hold on the last resort crypto.
+	 */
+	if (tp->md5sig_info->entries4) {
+		int i;
+		for (i = 0; i < tp->md5sig_info->entries4; i++)
+			kfree(tp->md5sig_info->keys4[i].base.key);
+		tp->md5sig_info->entries4 = 0;
+		tcp_free_md5sig_pool();
+	}
+	if (tp->md5sig_info->keys4) {
+		kfree(tp->md5sig_info->keys4);
+		tp->md5sig_info->keys4 = NULL;
+		tp->md5sig_info->alloced4  = 0;
+	}
+}
+
+static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval,
+				 int optlen)
+{
+	struct tcp_md5sig cmd;
+	struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr;
+	u8 *newkey;
+
+	if (optlen < sizeof(cmd))
+		return -EINVAL;
+
+	if (copy_from_user(&cmd, optval, sizeof(cmd)))
+		return -EFAULT;
+
+	if (sin->sin_family != AF_INET)
+		return -EINVAL;
+
+	if (!cmd.tcpm_key || !cmd.tcpm_keylen) {
+		if (!tcp_sk(sk)->md5sig_info)
+			return -ENOENT;
+		return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
+	}
+
+	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
+		return -EINVAL;
+
+	if (!tcp_sk(sk)->md5sig_info) {
+		struct tcp_sock *tp = tcp_sk(sk);
+		struct tcp_md5sig_info *p = kzalloc(sizeof(*p), GFP_KERNEL);
+
+		if (!p)
+			return -EINVAL;
+
+		tp->md5sig_info = p;
+		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+	}
+
+	newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
+	if (!newkey)
+		return -ENOMEM;
+	return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
+				 newkey, cmd.tcpm_keylen);
+}
+
+static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
+					__be32 daddr, __be32 saddr, int nbytes)
+{
+	struct tcp4_pseudohdr *bp;
+	struct scatterlist sg;
+
+	bp = &hp->md5_blk.ip4;
+
+	/*
+	 * 1. the TCP pseudo-header (in the order: source IP address,
+	 * destination IP address, zero-padded protocol number, and
+	 * segment length)
+	 */
+	bp->saddr = saddr;
+	bp->daddr = daddr;
+	bp->pad = 0;
+	bp->protocol = IPPROTO_TCP;
+	bp->len = cpu_to_be16(nbytes);
+
+	sg_init_one(&sg, bp, sizeof(*bp));
+	return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
+}
+
+static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
+			       __be32 daddr, __be32 saddr, struct tcphdr *th)
+{
+	struct tcp_md5sig_pool *hp;
+	struct hash_desc *desc;
+
+	hp = tcp_get_md5sig_pool();
+	if (!hp)
+		goto clear_hash_noput;
+	desc = &hp->md5_desc;
+
+	if (crypto_hash_init(desc))
+		goto clear_hash;
+	if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
+		goto clear_hash;
+	if (tcp_md5_hash_header(hp, th))
+		goto clear_hash;
+	if (tcp_md5_hash_key(hp, key))
+		goto clear_hash;
+	if (crypto_hash_final(desc, md5_hash))
+		goto clear_hash;
+
+	tcp_put_md5sig_pool();
+	return 0;
+
+clear_hash:
+	tcp_put_md5sig_pool();
+clear_hash_noput:
+	memset(md5_hash, 0, 16);
+	return 1;
+}
+
+int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
+			struct sock *sk, struct request_sock *req,
+			struct sk_buff *skb)
+{
+	struct tcp_md5sig_pool *hp;
+	struct hash_desc *desc;
+	struct tcphdr *th = tcp_hdr(skb);
+	__be32 saddr, daddr;
+
+	if (sk) {
+		saddr = inet_sk(sk)->saddr;
+		daddr = inet_sk(sk)->daddr;
+	} else if (req) {
+		saddr = inet_rsk(req)->loc_addr;
+		daddr = inet_rsk(req)->rmt_addr;
+	} else {
+		const struct iphdr *iph = ip_hdr(skb);
+		saddr = iph->saddr;
+		daddr = iph->daddr;
+	}
+
+	hp = tcp_get_md5sig_pool();
+	if (!hp)
+		goto clear_hash_noput;
+	desc = &hp->md5_desc;
+
+	if (crypto_hash_init(desc))
+		goto clear_hash;
+
+	if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
+		goto clear_hash;
+	if (tcp_md5_hash_header(hp, th))
+		goto clear_hash;
+	if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+		goto clear_hash;
+	if (tcp_md5_hash_key(hp, key))
+		goto clear_hash;
+	if (crypto_hash_final(desc, md5_hash))
+		goto clear_hash;
+
+	tcp_put_md5sig_pool();
+	return 0;
+
+clear_hash:
+	tcp_put_md5sig_pool();
+clear_hash_noput:
+	memset(md5_hash, 0, 16);
+	return 1;
+}
+
+EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
+
+static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
+{
+	/*
+	 * This gets called for each TCP segment that arrives
+	 * so we want to be efficient.
+	 * We have 3 drop cases:
+	 * o No MD5 hash and one expected.
+	 * o MD5 hash and we're not expecting one.
+	 * o MD5 hash and its wrong.
+	 */
+	__u8 *hash_location = NULL;
+	struct tcp_md5sig_key *hash_expected;
+	const struct iphdr *iph = ip_hdr(skb);
+	struct tcphdr *th = tcp_hdr(skb);
+	int genhash;
+	unsigned char newhash[16];
+
+	hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
+	hash_location = tcp_parse_md5sig_option(th);
+
+	/* We've parsed the options - do we have a hash? */
+	if (!hash_expected && !hash_location)
+		return 0;
+
+	if (hash_expected && !hash_location) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
+		return 1;
+	}
+
+	if (!hash_expected && hash_location) {
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
+		return 1;
+	}
+
+	/* Okay, so this is hash_expected and hash_location -
+	 * so we need to calculate the checksum.
+	 */
+	genhash = tcp_v4_md5_hash_skb(newhash,
+				      hash_expected,
+				      NULL, NULL, skb);
+
+	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
+		if (net_ratelimit()) {
+			printk(KERN_INFO "MD5 Hash failed for "
+			       "(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)%s\n",
+			       NIPQUAD(iph->saddr), ntohs(th->source),
+			       NIPQUAD(iph->daddr), ntohs(th->dest),
+			       genhash ? " tcp_v4_calc_md5_hash failed" : "");
+		}
+		return 1;
+	}
+	return 0;
+}
+
+#endif
+
+struct request_sock_ops tcp_request_sock_ops __read_mostly = {
+	.family		=	PF_INET,
+	.obj_size	=	sizeof(struct tcp_request_sock),
+	.rtx_syn_ack	=	tcp_v4_send_synack,
+	.send_ack	=	tcp_v4_reqsk_send_ack,
+	.destructor	=	tcp_v4_reqsk_destructor,
+	.send_reset	=	tcp_v4_send_reset,
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
+	.md5_lookup	=	tcp_v4_reqsk_md5_lookup,
+};
+#endif
+
+static struct timewait_sock_ops tcp_timewait_sock_ops = {
+	.twsk_obj_size	= sizeof(struct tcp_timewait_sock),
+	.twsk_unique	= tcp_twsk_unique,
+	.twsk_destructor= tcp_twsk_destructor,
+};
+
+int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
+{
+	struct inet_request_sock *ireq;
+	struct tcp_options_received tmp_opt;
+	struct request_sock *req;
+	__be32 saddr = ip_hdr(skb)->saddr;
+	__be32 daddr = ip_hdr(skb)->daddr;
+	__u32 isn = TCP_SKB_CB(skb)->when;
+	struct dst_entry *dst = NULL;
+#ifdef CONFIG_SYN_COOKIES
+	int want_cookie = 0;
+#else
+#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
+#endif
+
+	/* Never answer to SYNs send to broadcast or multicast */
+	if (skb->rtable->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
+		goto drop;
+
+	/* TW buckets are converted to open requests without
+	 * limitations, they conserve resources and peer is
+	 * evidently real one.
+	 */
+	if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
+#ifdef CONFIG_SYN_COOKIES
+		if (sysctl_tcp_syncookies) {
+			want_cookie = 1;
+		} else
+#endif
+		goto drop;
+	}
+
+	/* Accept backlog is full. If we have already queued enough
+	 * of warm entries in syn queue, drop request. It is better than
+	 * clogging syn queue with openreqs with exponentially increasing
+	 * timeout.
+	 */
+	if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
+		goto drop;
+
+	req = inet_reqsk_alloc(&tcp_request_sock_ops);
+	if (!req)
+		goto drop;
+
+#ifdef CONFIG_TCP_MD5SIG
+	tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
+#endif
+
+	tcp_clear_options(&tmp_opt);
+	tmp_opt.mss_clamp = 536;
+	tmp_opt.user_mss  = tcp_sk(sk)->rx_opt.user_mss;
+
+	tcp_parse_options(skb, &tmp_opt, 0);
+
+	if (want_cookie && !tmp_opt.saw_tstamp)
+		tcp_clear_options(&tmp_opt);
+
+	if (tmp_opt.saw_tstamp && !tmp_opt.rcv_tsval) {
+		/* Some OSes (unknown ones, but I see them on web server, which
+		 * contains information interesting only for windows'
+		 * users) do not send their stamp in SYN. It is easy case.
+		 * We simply do not advertise TS support.
+		 */
+		tmp_opt.saw_tstamp = 0;
+		tmp_opt.tstamp_ok  = 0;
+	}
+	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
+
+	tcp_openreq_init(req, &tmp_opt, skb);
+
+	if (security_inet_conn_request(sk, skb, req))
+		goto drop_and_free;
+
+	ireq = inet_rsk(req);
+	ireq->loc_addr = daddr;
+	ireq->rmt_addr = saddr;
+	ireq->no_srccheck = inet_sk(sk)->transparent;
+	ireq->opt = tcp_v4_save_options(sk, skb);
+	if (!want_cookie)
+		TCP_ECN_create_request(req, tcp_hdr(skb));
+
+	if (want_cookie) {
+#ifdef CONFIG_SYN_COOKIES
+		syn_flood_warning(skb);
+		req->cookie_ts = tmp_opt.tstamp_ok;
+#endif
+		isn = cookie_v4_init_sequence(sk, skb, &req->mss);
+	} else if (!isn) {
+		struct inet_peer *peer = NULL;
+
+		/* VJ's idea. We save last timestamp seen
+		 * from the destination in peer table, when entering
+		 * state TIME-WAIT, and check against it before
+		 * accepting new connection request.
+		 *
+		 * If "isn" is not zero, this request hit alive
+		 * timewait bucket, so that all the necessary checks
+		 * are made in the function processing timewait state.
+		 */
+		if (tmp_opt.saw_tstamp &&
+		    tcp_death_row.sysctl_tw_recycle &&
+		    (dst = inet_csk_route_req(sk, req)) != NULL &&
+		    (peer = rt_get_peer((struct rtable *)dst)) != NULL &&
+		    peer->v4daddr == saddr) {
+			if (get_seconds() < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
+			    (s32)(peer->tcp_ts - req->ts_recent) >
+							TCP_PAWS_WINDOW) {
+				NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
+				goto drop_and_release;
+			}
+		}
+		/* Kill the following clause, if you dislike this way. */
+		else if (!sysctl_tcp_syncookies &&
+			 (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
+			  (sysctl_max_syn_backlog >> 2)) &&
+			 (!peer || !peer->tcp_ts_stamp) &&
+			 (!dst || !dst_metric(dst, RTAX_RTT))) {
+			/* Without syncookies last quarter of
+			 * backlog is filled with destinations,
+			 * proven to be alive.
+			 * It means that we continue to communicate
+			 * to destinations, already remembered
+			 * to the moment of synflood.
+			 */
+			LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open "
+				       "request from " NIPQUAD_FMT "/%u\n",
+				       NIPQUAD(saddr),
+				       ntohs(tcp_hdr(skb)->source));
+			goto drop_and_release;
+		}
+
+		isn = tcp_v4_init_sequence(skb);
+	}
+	tcp_rsk(req)->snt_isn = isn;
+
+	if (__tcp_v4_send_synack(sk, req, dst) || want_cookie)
+		goto drop_and_free;
+
+	inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
+	return 0;
+
+drop_and_release:
+	dst_release(dst);
+drop_and_free:
+	reqsk_free(req);
+drop:
+	return 0;
+}
+
+
+/*
+ * The three way handshake has completed - we got a valid synack -
+ * now create the new socket.
+ */
+struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
+				  struct request_sock *req,
+				  struct dst_entry *dst)
+{
+	struct inet_request_sock *ireq;
+	struct inet_sock *newinet;
+	struct tcp_sock *newtp;
+	struct sock *newsk;
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_md5sig_key *key;
+#endif
+
+	if (sk_acceptq_is_full(sk))
+		goto exit_overflow;
+
+	if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
+		goto exit;
+
+	newsk = tcp_create_openreq_child(sk, req, skb);
+	if (!newsk)
+		goto exit;
+
+	newsk->sk_gso_type = SKB_GSO_TCPV4;
+	sk_setup_caps(newsk, dst);
+
+	newtp		      = tcp_sk(newsk);
+	newinet		      = inet_sk(newsk);
+	ireq		      = inet_rsk(req);
+	newinet->daddr	      = ireq->rmt_addr;
+	newinet->rcv_saddr    = ireq->loc_addr;
+	newinet->saddr	      = ireq->loc_addr;
+	newinet->opt	      = ireq->opt;
+	ireq->opt	      = NULL;
+	newinet->mc_index     = inet_iif(skb);
+	newinet->mc_ttl	      = ip_hdr(skb)->ttl;
+	inet_csk(newsk)->icsk_ext_hdr_len = 0;
+	if (newinet->opt)
+		inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
+	newinet->id = newtp->write_seq ^ jiffies;
+
+	tcp_mtup_init(newsk);
+	tcp_sync_mss(newsk, dst_mtu(dst));
+	newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
+	if (tcp_sk(sk)->rx_opt.user_mss &&
+	    tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
+		newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
+
+	tcp_initialize_rcv_mss(newsk);
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Copy over the MD5 key from the original socket */
+	if ((key = tcp_v4_md5_do_lookup(sk, newinet->daddr)) != NULL) {
+		/*
+		 * We're using one, so create a matching key
+		 * on the newsk structure. If we fail to get
+		 * memory, then we end up not copying the key
+		 * across. Shucks.
+		 */
+		char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
+		if (newkey != NULL)
+			tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
+					  newkey, key->keylen);
+		newsk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+	}
+#endif
+
+	__inet_hash_nolisten(newsk);
+	__inet_inherit_port(sk, newsk);
+
+	return newsk;
+
+exit_overflow:
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+exit:
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
+	dst_release(dst);
+	return NULL;
+}
+
+static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcphdr *th = tcp_hdr(skb);
+	const struct iphdr *iph = ip_hdr(skb);
+	struct sock *nsk;
+	struct request_sock **prev;
+	/* Find possible connection requests. */
+	struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
+						       iph->saddr, iph->daddr);
+	if (req)
+		return tcp_check_req(sk, skb, req, prev);
+
+	nsk = inet_lookup_established(sock_net(sk), &tcp_hashinfo, iph->saddr,
+			th->source, iph->daddr, th->dest, inet_iif(skb));
+
+	if (nsk) {
+		if (nsk->sk_state != TCP_TIME_WAIT) {
+			bh_lock_sock(nsk);
+			return nsk;
+		}
+		inet_twsk_put(inet_twsk(nsk));
+		return NULL;
+	}
+
+#ifdef CONFIG_SYN_COOKIES
+	if (!th->rst && !th->syn && th->ack)
+		sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
+#endif
+	return sk;
+}
+
+static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
+{
+	const struct iphdr *iph = ip_hdr(skb);
+
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
+		if (!tcp_v4_check(skb->len, iph->saddr,
+				  iph->daddr, skb->csum)) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			return 0;
+		}
+	}
+
+	skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
+				       skb->len, IPPROTO_TCP, 0);
+
+	if (skb->len <= 76) {
+		return __skb_checksum_complete(skb);
+	}
+	return 0;
+}
+
+
+/* The socket must have it's spinlock held when we get
+ * here.
+ *
+ * We have a potential double-lock case here, so even when
+ * doing backlog processing we use the BH locking scheme.
+ * This is because we cannot sleep with the original spinlock
+ * held.
+ */
+int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct sock *rsk;
+#ifdef CONFIG_TCP_MD5SIG
+	/*
+	 * We really want to reject the packet as early as possible
+	 * if:
+	 *  o We're expecting an MD5'd packet and this is no MD5 tcp option
+	 *  o There is an MD5 option and we're not expecting one
+	 */
+	if (tcp_v4_inbound_md5_hash(sk, skb))
+		goto discard;
+#endif
+
+	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
+		TCP_CHECK_TIMER(sk);
+		if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
+			rsk = sk;
+			goto reset;
+		}
+		TCP_CHECK_TIMER(sk);
+		return 0;
+	}
+
+	if (skb->len < tcp_hdrlen(skb) || tcp_checksum_complete(skb))
+		goto csum_err;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		struct sock *nsk = tcp_v4_hnd_req(sk, skb);
+		if (!nsk)
+			goto discard;
+
+		if (nsk != sk) {
+			if (tcp_child_process(sk, nsk, skb)) {
+				rsk = nsk;
+				goto reset;
+			}
+			return 0;
+		}
+	}
+
+	TCP_CHECK_TIMER(sk);
+	if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
+		rsk = sk;
+		goto reset;
+	}
+	TCP_CHECK_TIMER(sk);
+	return 0;
+
+reset:
+	tcp_v4_send_reset(rsk, skb);
+discard:
+	kfree_skb(skb);
+	/* Be careful here. If this function gets more complicated and
+	 * gcc suffers from register pressure on the x86, sk (in %ebx)
+	 * might be destroyed here. This current version compiles correctly,
+	 * but you have been warned.
+	 */
+	return 0;
+
+csum_err:
+	TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
+	goto discard;
+}
+
+/*
+ *	From tcp_input.c
+ */
+
+int tcp_v4_rcv(struct sk_buff *skb)
+{
+	const struct iphdr *iph;
+	struct tcphdr *th;
+	struct sock *sk;
+	int ret;
+	struct net *net = dev_net(skb->dev);
+
+	if (skb->pkt_type != PACKET_HOST)
+		goto discard_it;
+
+	/* Count it even if it's bad */
+	TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
+
+	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
+		goto discard_it;
+
+	th = tcp_hdr(skb);
+
+	if (th->doff < sizeof(struct tcphdr) / 4)
+		goto bad_packet;
+	if (!pskb_may_pull(skb, th->doff * 4))
+		goto discard_it;
+
+	/* An explanation is required here, I think.
+	 * Packet length and doff are validated by header prediction,
+	 * provided case of th->doff==0 is eliminated.
+	 * So, we defer the checks. */
+	if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
+		goto bad_packet;
+
+	th = tcp_hdr(skb);
+	iph = ip_hdr(skb);
+	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
+	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
+				    skb->len - th->doff * 4);
+	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+	TCP_SKB_CB(skb)->when	 = 0;
+	TCP_SKB_CB(skb)->flags	 = iph->tos;
+	TCP_SKB_CB(skb)->sacked	 = 0;
+
+	sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
+	if (!sk)
+		goto no_tcp_socket;
+
+process:
+	if (sk->sk_state == TCP_TIME_WAIT)
+		goto do_time_wait;
+
+	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+		goto discard_and_relse;
+	nf_reset(skb);
+
+	if (sk_filter(sk, skb))
+		goto discard_and_relse;
+
+	skb->dev = NULL;
+
+	bh_lock_sock_nested(sk);
+	ret = 0;
+	if (!sock_owned_by_user(sk)) {
+#ifdef CONFIG_NET_DMA
+		struct tcp_sock *tp = tcp_sk(sk);
+		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
+			tp->ucopy.dma_chan = get_softnet_dma();
+		if (tp->ucopy.dma_chan)
+			ret = tcp_v4_do_rcv(sk, skb);
+		else
+#endif
+		{
+			if (!tcp_prequeue(sk, skb))
+			ret = tcp_v4_do_rcv(sk, skb);
+		}
+	} else
+		sk_add_backlog(sk, skb);
+	bh_unlock_sock(sk);
+
+	sock_put(sk);
+
+	return ret;
+
+no_tcp_socket:
+	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+		goto discard_it;
+
+	if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
+bad_packet:
+		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
+	} else {
+		tcp_v4_send_reset(NULL, skb);
+	}
+
+discard_it:
+	/* Discard frame. */
+	kfree_skb(skb);
+	return 0;
+
+discard_and_relse:
+	sock_put(sk);
+	goto discard_it;
+
+do_time_wait:
+	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+		inet_twsk_put(inet_twsk(sk));
+		goto discard_it;
+	}
+
+	if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
+		TCP_INC_STATS_BH(net, TCP_MIB_INERRS);
+		inet_twsk_put(inet_twsk(sk));
+		goto discard_it;
+	}
+	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
+	case TCP_TW_SYN: {
+		struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev),
+							&tcp_hashinfo,
+							iph->daddr, th->dest,
+							inet_iif(skb));
+		if (sk2) {
+			inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
+			inet_twsk_put(inet_twsk(sk));
+			sk = sk2;
+			goto process;
+		}
+		/* Fall through to ACK */
+	}
+	case TCP_TW_ACK:
+		tcp_v4_timewait_ack(sk, skb);
+		break;
+	case TCP_TW_RST:
+		goto no_tcp_socket;
+	case TCP_TW_SUCCESS:;
+	}
+	goto discard_it;
+}
+
+/* VJ's idea. Save last timestamp seen from this destination
+ * and hold it at least for normal timewait interval to use for duplicate
+ * segment detection in subsequent connections, before they enter synchronized
+ * state.
+ */
+
+int tcp_v4_remember_stamp(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct rtable *rt = (struct rtable *)__sk_dst_get(sk);
+	struct inet_peer *peer = NULL;
+	int release_it = 0;
+
+	if (!rt || rt->rt_dst != inet->daddr) {
+		peer = inet_getpeer(inet->daddr, 1);
+		release_it = 1;
+	} else {
+		if (!rt->peer)
+			rt_bind_peer(rt, 1);
+		peer = rt->peer;
+	}
+
+	if (peer) {
+		if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 ||
+		    (peer->tcp_ts_stamp + TCP_PAWS_MSL < get_seconds() &&
+		     peer->tcp_ts_stamp <= tp->rx_opt.ts_recent_stamp)) {
+			peer->tcp_ts_stamp = tp->rx_opt.ts_recent_stamp;
+			peer->tcp_ts = tp->rx_opt.ts_recent;
+		}
+		if (release_it)
+			inet_putpeer(peer);
+		return 1;
+	}
+
+	return 0;
+}
+
+int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw)
+{
+	struct inet_peer *peer = inet_getpeer(tw->tw_daddr, 1);
+
+	if (peer) {
+		const struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
+
+		if ((s32)(peer->tcp_ts - tcptw->tw_ts_recent) <= 0 ||
+		    (peer->tcp_ts_stamp + TCP_PAWS_MSL < get_seconds() &&
+		     peer->tcp_ts_stamp <= tcptw->tw_ts_recent_stamp)) {
+			peer->tcp_ts_stamp = tcptw->tw_ts_recent_stamp;
+			peer->tcp_ts	   = tcptw->tw_ts_recent;
+		}
+		inet_putpeer(peer);
+		return 1;
+	}
+
+	return 0;
+}
+
+struct inet_connection_sock_af_ops ipv4_specific = {
+	.queue_xmit	   = ip_queue_xmit,
+	.send_check	   = tcp_v4_send_check,
+	.rebuild_header	   = inet_sk_rebuild_header,
+	.conn_request	   = tcp_v4_conn_request,
+	.syn_recv_sock	   = tcp_v4_syn_recv_sock,
+	.remember_stamp	   = tcp_v4_remember_stamp,
+	.net_header_len	   = sizeof(struct iphdr),
+	.setsockopt	   = ip_setsockopt,
+	.getsockopt	   = ip_getsockopt,
+	.addr2sockaddr	   = inet_csk_addr2sockaddr,
+	.sockaddr_len	   = sizeof(struct sockaddr_in),
+	.bind_conflict	   = inet_csk_bind_conflict,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_ip_setsockopt,
+	.compat_getsockopt = compat_ip_getsockopt,
+#endif
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
+	.md5_lookup		= tcp_v4_md5_lookup,
+	.calc_md5_hash		= tcp_v4_md5_hash_skb,
+	.md5_add		= tcp_v4_md5_add_func,
+	.md5_parse		= tcp_v4_parse_md5_keys,
+};
+#endif
+
+/* NOTE: A lot of things set to zero explicitly by call to
+ *       sk_alloc() so need not be done here.
+ */
+static int tcp_v4_init_sock(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	skb_queue_head_init(&tp->out_of_order_queue);
+	tcp_init_xmit_timers(sk);
+	tcp_prequeue_init(tp);
+
+	icsk->icsk_rto = TCP_TIMEOUT_INIT;
+	tp->mdev = TCP_TIMEOUT_INIT;
+
+	/* So many TCP implementations out there (incorrectly) count the
+	 * initial SYN frame in their delayed-ACK and congestion control
+	 * algorithms that we must have the following bandaid to talk
+	 * efficiently to them.  -DaveM
+	 */
+	tp->snd_cwnd = 2;
+
+	/* See draft-stevens-tcpca-spec-01 for discussion of the
+	 * initialization of these values.
+	 */
+	tp->snd_ssthresh = 0x7fffffff;	/* Infinity */
+	tp->snd_cwnd_clamp = ~0;
+	tp->mss_cache = 536;
+
+	tp->reordering = sysctl_tcp_reordering;
+	icsk->icsk_ca_ops = &tcp_init_congestion_ops;
+
+	sk->sk_state = TCP_CLOSE;
+
+	sk->sk_write_space = sk_stream_write_space;
+	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
+
+	icsk->icsk_af_ops = &ipv4_specific;
+	icsk->icsk_sync_mss = tcp_sync_mss;
+#ifdef CONFIG_TCP_MD5SIG
+	tp->af_specific = &tcp_sock_ipv4_specific;
+#endif
+
+	sk->sk_sndbuf = sysctl_tcp_wmem[1];
+	sk->sk_rcvbuf = sysctl_tcp_rmem[1];
+
+	atomic_inc(&tcp_sockets_allocated);
+
+	return 0;
+}
+
+void tcp_v4_destroy_sock(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	tcp_clear_xmit_timers(sk);
+
+	tcp_cleanup_congestion_control(sk);
+
+	/* Cleanup up the write buffer. */
+	tcp_write_queue_purge(sk);
+
+	/* Cleans up our, hopefully empty, out_of_order_queue. */
+	__skb_queue_purge(&tp->out_of_order_queue);
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Clean up the MD5 key list, if any */
+	if (tp->md5sig_info) {
+		tcp_v4_clear_md5_list(sk);
+		kfree(tp->md5sig_info);
+		tp->md5sig_info = NULL;
+	}
+#endif
+
+#ifdef CONFIG_NET_DMA
+	/* Cleans up our sk_async_wait_queue */
+	__skb_queue_purge(&sk->sk_async_wait_queue);
+#endif
+
+	/* Clean prequeue, it must be empty really */
+	__skb_queue_purge(&tp->ucopy.prequeue);
+
+	/* Clean up a referenced TCP bind bucket. */
+	if (inet_csk(sk)->icsk_bind_hash)
+		inet_put_port(sk);
+
+	/*
+	 * If sendmsg cached page exists, toss it.
+	 */
+	if (sk->sk_sndmsg_page) {
+		__free_page(sk->sk_sndmsg_page);
+		sk->sk_sndmsg_page = NULL;
+	}
+
+	atomic_dec(&tcp_sockets_allocated);
+}
+
+EXPORT_SYMBOL(tcp_v4_destroy_sock);
+
+#ifdef CONFIG_PROC_FS
+/* Proc filesystem TCP sock list dumping. */
+
+static inline struct inet_timewait_sock *tw_head(struct hlist_head *head)
+{
+	return hlist_empty(head) ? NULL :
+		list_entry(head->first, struct inet_timewait_sock, tw_node);
+}
+
+static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
+{
+	return tw->tw_node.next ?
+		hlist_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
+}
+
+static void *listening_get_next(struct seq_file *seq, void *cur)
+{
+	struct inet_connection_sock *icsk;
+	struct hlist_node *node;
+	struct sock *sk = cur;
+	struct tcp_iter_state* st = seq->private;
+	struct net *net = seq_file_net(seq);
+
+	if (!sk) {
+		st->bucket = 0;
+		sk = sk_head(&tcp_hashinfo.listening_hash[0]);
+		goto get_sk;
+	}
+
+	++st->num;
+
+	if (st->state == TCP_SEQ_STATE_OPENREQ) {
+		struct request_sock *req = cur;
+
+		icsk = inet_csk(st->syn_wait_sk);
+		req = req->dl_next;
+		while (1) {
+			while (req) {
+				if (req->rsk_ops->family == st->family) {
+					cur = req;
+					goto out;
+				}
+				req = req->dl_next;
+			}
+			if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
+				break;
+get_req:
+			req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
+		}
+		sk	  = sk_next(st->syn_wait_sk);
+		st->state = TCP_SEQ_STATE_LISTENING;
+		read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+	} else {
+		icsk = inet_csk(sk);
+		read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+		if (reqsk_queue_len(&icsk->icsk_accept_queue))
+			goto start_req;
+		read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+		sk = sk_next(sk);
+	}
+get_sk:
+	sk_for_each_from(sk, node) {
+		if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) {
+			cur = sk;
+			goto out;
+		}
+		icsk = inet_csk(sk);
+		read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+		if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
+start_req:
+			st->uid		= sock_i_uid(sk);
+			st->syn_wait_sk = sk;
+			st->state	= TCP_SEQ_STATE_OPENREQ;
+			st->sbucket	= 0;
+			goto get_req;
+		}
+		read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+	}
+	if (++st->bucket < INET_LHTABLE_SIZE) {
+		sk = sk_head(&tcp_hashinfo.listening_hash[st->bucket]);
+		goto get_sk;
+	}
+	cur = NULL;
+out:
+	return cur;
+}
+
+static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
+{
+	void *rc = listening_get_next(seq, NULL);
+
+	while (rc && *pos) {
+		rc = listening_get_next(seq, rc);
+		--*pos;
+	}
+	return rc;
+}
+
+static inline int empty_bucket(struct tcp_iter_state *st)
+{
+	return hlist_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
+		hlist_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
+}
+
+static void *established_get_first(struct seq_file *seq)
+{
+	struct tcp_iter_state* st = seq->private;
+	struct net *net = seq_file_net(seq);
+	void *rc = NULL;
+
+	for (st->bucket = 0; st->bucket < tcp_hashinfo.ehash_size; ++st->bucket) {
+		struct sock *sk;
+		struct hlist_node *node;
+		struct inet_timewait_sock *tw;
+		rwlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
+
+		/* Lockless fast path for the common case of empty buckets */
+		if (empty_bucket(st))
+			continue;
+
+		read_lock_bh(lock);
+		sk_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
+			if (sk->sk_family != st->family ||
+			    !net_eq(sock_net(sk), net)) {
+				continue;
+			}
+			rc = sk;
+			goto out;
+		}
+		st->state = TCP_SEQ_STATE_TIME_WAIT;
+		inet_twsk_for_each(tw, node,
+				   &tcp_hashinfo.ehash[st->bucket].twchain) {
+			if (tw->tw_family != st->family ||
+			    !net_eq(twsk_net(tw), net)) {
+				continue;
+			}
+			rc = tw;
+			goto out;
+		}
+		read_unlock_bh(lock);
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
+	}
+out:
+	return rc;
+}
+
+static void *established_get_next(struct seq_file *seq, void *cur)
+{
+	struct sock *sk = cur;
+	struct inet_timewait_sock *tw;
+	struct hlist_node *node;
+	struct tcp_iter_state* st = seq->private;
+	struct net *net = seq_file_net(seq);
+
+	++st->num;
+
+	if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
+		tw = cur;
+		tw = tw_next(tw);
+get_tw:
+		while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
+			tw = tw_next(tw);
+		}
+		if (tw) {
+			cur = tw;
+			goto out;
+		}
+		read_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
+
+		/* Look for next non empty bucket */
+		while (++st->bucket < tcp_hashinfo.ehash_size &&
+				empty_bucket(st))
+			;
+		if (st->bucket >= tcp_hashinfo.ehash_size)
+			return NULL;
+
+		read_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
+		sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain);
+	} else
+		sk = sk_next(sk);
+
+	sk_for_each_from(sk, node) {
+		if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
+			goto found;
+	}
+
+	st->state = TCP_SEQ_STATE_TIME_WAIT;
+	tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
+	goto get_tw;
+found:
+	cur = sk;
+out:
+	return cur;
+}
+
+static void *established_get_idx(struct seq_file *seq, loff_t pos)
+{
+	void *rc = established_get_first(seq);
+
+	while (rc && pos) {
+		rc = established_get_next(seq, rc);
+		--pos;
+	}
+	return rc;
+}
+
+static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
+{
+	void *rc;
+	struct tcp_iter_state* st = seq->private;
+
+	inet_listen_lock(&tcp_hashinfo);
+	st->state = TCP_SEQ_STATE_LISTENING;
+	rc	  = listening_get_idx(seq, &pos);
+
+	if (!rc) {
+		inet_listen_unlock(&tcp_hashinfo);
+		st->state = TCP_SEQ_STATE_ESTABLISHED;
+		rc	  = established_get_idx(seq, pos);
+	}
+
+	return rc;
+}
+
+static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	struct tcp_iter_state* st = seq->private;
+	st->state = TCP_SEQ_STATE_LISTENING;
+	st->num = 0;
+	return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	void *rc = NULL;
+	struct tcp_iter_state* st;
+
+	if (v == SEQ_START_TOKEN) {
+		rc = tcp_get_idx(seq, 0);
+		goto out;
+	}
+	st = seq->private;
+
+	switch (st->state) {
+	case TCP_SEQ_STATE_OPENREQ:
+	case TCP_SEQ_STATE_LISTENING:
+		rc = listening_get_next(seq, v);
+		if (!rc) {
+			inet_listen_unlock(&tcp_hashinfo);
+			st->state = TCP_SEQ_STATE_ESTABLISHED;
+			rc	  = established_get_first(seq);
+		}
+		break;
+	case TCP_SEQ_STATE_ESTABLISHED:
+	case TCP_SEQ_STATE_TIME_WAIT:
+		rc = established_get_next(seq, v);
+		break;
+	}
+out:
+	++*pos;
+	return rc;
+}
+
+static void tcp_seq_stop(struct seq_file *seq, void *v)
+{
+	struct tcp_iter_state* st = seq->private;
+
+	switch (st->state) {
+	case TCP_SEQ_STATE_OPENREQ:
+		if (v) {
+			struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
+			read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
+		}
+	case TCP_SEQ_STATE_LISTENING:
+		if (v != SEQ_START_TOKEN)
+			inet_listen_unlock(&tcp_hashinfo);
+		break;
+	case TCP_SEQ_STATE_TIME_WAIT:
+	case TCP_SEQ_STATE_ESTABLISHED:
+		if (v)
+			read_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
+		break;
+	}
+}
+
+static int tcp_seq_open(struct inode *inode, struct file *file)
+{
+	struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
+	struct tcp_iter_state *s;
+	int err;
+
+	err = seq_open_net(inode, file, &afinfo->seq_ops,
+			  sizeof(struct tcp_iter_state));
+	if (err < 0)
+		return err;
+
+	s = ((struct seq_file *)file->private_data)->private;
+	s->family		= afinfo->family;
+	return 0;
+}
+
+int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
+{
+	int rc = 0;
+	struct proc_dir_entry *p;
+
+	afinfo->seq_fops.open		= tcp_seq_open;
+	afinfo->seq_fops.read		= seq_read;
+	afinfo->seq_fops.llseek		= seq_lseek;
+	afinfo->seq_fops.release	= seq_release_net;
+
+	afinfo->seq_ops.start		= tcp_seq_start;
+	afinfo->seq_ops.next		= tcp_seq_next;
+	afinfo->seq_ops.stop		= tcp_seq_stop;
+
+	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
+			     &afinfo->seq_fops, afinfo);
+	if (!p)
+		rc = -ENOMEM;
+	return rc;
+}
+
+void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
+{
+	proc_net_remove(net, afinfo->name);
+}
+
+static void get_openreq4(struct sock *sk, struct request_sock *req,
+			 struct seq_file *f, int i, int uid, int *len)
+{
+	const struct inet_request_sock *ireq = inet_rsk(req);
+	int ttd = req->expires - jiffies;
+
+	seq_printf(f, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",
+		i,
+		ireq->loc_addr,
+		ntohs(inet_sk(sk)->sport),
+		ireq->rmt_addr,
+		ntohs(ireq->rmt_port),
+		TCP_SYN_RECV,
+		0, 0, /* could print option size, but that is af dependent. */
+		1,    /* timers active (only the expire timer) */
+		jiffies_to_clock_t(ttd),
+		req->retrans,
+		uid,
+		0,  /* non standard timer */
+		0, /* open_requests have no inode */
+		atomic_read(&sk->sk_refcnt),
+		req,
+		len);
+}
+
+static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
+{
+	int timer_active;
+	unsigned long timer_expires;
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct inet_sock *inet = inet_sk(sk);
+	__be32 dest = inet->daddr;
+	__be32 src = inet->rcv_saddr;
+	__u16 destp = ntohs(inet->dport);
+	__u16 srcp = ntohs(inet->sport);
+
+	if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
+		timer_active	= 1;
+		timer_expires	= icsk->icsk_timeout;
+	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
+		timer_active	= 4;
+		timer_expires	= icsk->icsk_timeout;
+	} else if (timer_pending(&sk->sk_timer)) {
+		timer_active	= 2;
+		timer_expires	= sk->sk_timer.expires;
+	} else {
+		timer_active	= 0;
+		timer_expires = jiffies;
+	}
+
+	seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
+			"%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n",
+		i, src, srcp, dest, destp, sk->sk_state,
+		tp->write_seq - tp->snd_una,
+		sk->sk_state == TCP_LISTEN ? sk->sk_ack_backlog :
+					     (tp->rcv_nxt - tp->copied_seq),
+		timer_active,
+		jiffies_to_clock_t(timer_expires - jiffies),
+		icsk->icsk_retransmits,
+		sock_i_uid(sk),
+		icsk->icsk_probes_out,
+		sock_i_ino(sk),
+		atomic_read(&sk->sk_refcnt), sk,
+		jiffies_to_clock_t(icsk->icsk_rto),
+		jiffies_to_clock_t(icsk->icsk_ack.ato),
+		(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
+		tp->snd_cwnd,
+		tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh,
+		len);
+}
+
+static void get_timewait4_sock(struct inet_timewait_sock *tw,
+			       struct seq_file *f, int i, int *len)
+{
+	__be32 dest, src;
+	__u16 destp, srcp;
+	int ttd = tw->tw_ttd - jiffies;
+
+	if (ttd < 0)
+		ttd = 0;
+
+	dest  = tw->tw_daddr;
+	src   = tw->tw_rcv_saddr;
+	destp = ntohs(tw->tw_dport);
+	srcp  = ntohs(tw->tw_sport);
+
+	seq_printf(f, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",
+		i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
+		3, jiffies_to_clock_t(ttd), 0, 0, 0, 0,
+		atomic_read(&tw->tw_refcnt), tw, len);
+}
+
+#define TMPSZ 150
+
+static int tcp4_seq_show(struct seq_file *seq, void *v)
+{
+	struct tcp_iter_state* st;
+	int len;
+
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, "%-*s\n", TMPSZ - 1,
+			   "  sl  local_address rem_address   st tx_queue "
+			   "rx_queue tr tm->when retrnsmt   uid  timeout "
+			   "inode");
+		goto out;
+	}
+	st = seq->private;
+
+	switch (st->state) {
+	case TCP_SEQ_STATE_LISTENING:
+	case TCP_SEQ_STATE_ESTABLISHED:
+		get_tcp4_sock(v, seq, st->num, &len);
+		break;
+	case TCP_SEQ_STATE_OPENREQ:
+		get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
+		break;
+	case TCP_SEQ_STATE_TIME_WAIT:
+		get_timewait4_sock(v, seq, st->num, &len);
+		break;
+	}
+	seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
+out:
+	return 0;
+}
+
+static struct tcp_seq_afinfo tcp4_seq_afinfo = {
+	.name		= "tcp",
+	.family		= AF_INET,
+	.seq_fops	= {
+		.owner		= THIS_MODULE,
+	},
+	.seq_ops	= {
+		.show		= tcp4_seq_show,
+	},
+};
+
+static int tcp4_proc_init_net(struct net *net)
+{
+	return tcp_proc_register(net, &tcp4_seq_afinfo);
+}
+
+static void tcp4_proc_exit_net(struct net *net)
+{
+	tcp_proc_unregister(net, &tcp4_seq_afinfo);
+}
+
+static struct pernet_operations tcp4_net_ops = {
+	.init = tcp4_proc_init_net,
+	.exit = tcp4_proc_exit_net,
+};
+
+int __init tcp4_proc_init(void)
+{
+	return register_pernet_subsys(&tcp4_net_ops);
+}
+
+void tcp4_proc_exit(void)
+{
+	unregister_pernet_subsys(&tcp4_net_ops);
+}
+#endif /* CONFIG_PROC_FS */
+
+struct proto tcp_prot = {
+	.name			= "TCP",
+	.owner			= THIS_MODULE,
+	.close			= tcp_close,
+	.connect		= tcp_v4_connect,
+	.disconnect		= tcp_disconnect,
+	.accept			= inet_csk_accept,
+	.ioctl			= tcp_ioctl,
+	.init			= tcp_v4_init_sock,
+	.destroy		= tcp_v4_destroy_sock,
+	.shutdown		= tcp_shutdown,
+	.setsockopt		= tcp_setsockopt,
+	.getsockopt		= tcp_getsockopt,
+	.recvmsg		= tcp_recvmsg,
+	.backlog_rcv		= tcp_v4_do_rcv,
+	.hash			= inet_hash,
+	.unhash			= inet_unhash,
+	.get_port		= inet_csk_get_port,
+	.enter_memory_pressure	= tcp_enter_memory_pressure,
+	.sockets_allocated	= &tcp_sockets_allocated,
+	.orphan_count		= &tcp_orphan_count,
+	.memory_allocated	= &tcp_memory_allocated,
+	.memory_pressure	= &tcp_memory_pressure,
+	.sysctl_mem		= sysctl_tcp_mem,
+	.sysctl_wmem		= sysctl_tcp_wmem,
+	.sysctl_rmem		= sysctl_tcp_rmem,
+	.max_header		= MAX_TCP_HEADER,
+	.obj_size		= sizeof(struct tcp_sock),
+	.twsk_prot		= &tcp_timewait_sock_ops,
+	.rsk_prot		= &tcp_request_sock_ops,
+	.h.hashinfo		= &tcp_hashinfo,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt	= compat_tcp_setsockopt,
+	.compat_getsockopt	= compat_tcp_getsockopt,
+#endif
+};
+
+
+static int __net_init tcp_sk_init(struct net *net)
+{
+	return inet_ctl_sock_create(&net->ipv4.tcp_sock,
+				    PF_INET, SOCK_RAW, IPPROTO_TCP, net);
+}
+
+static void __net_exit tcp_sk_exit(struct net *net)
+{
+	inet_ctl_sock_destroy(net->ipv4.tcp_sock);
+	inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET);
+}
+
+static struct pernet_operations __net_initdata tcp_sk_ops = {
+       .init = tcp_sk_init,
+       .exit = tcp_sk_exit,
+};
+
+void __init tcp_v4_init(void)
+{
+	if (register_pernet_device(&tcp_sk_ops))
+		panic("Failed to create the TCP control socket.\n");
+}
+
+EXPORT_SYMBOL(ipv4_specific);
+EXPORT_SYMBOL(tcp_hashinfo);
+EXPORT_SYMBOL(tcp_prot);
+EXPORT_SYMBOL(tcp_v4_conn_request);
+EXPORT_SYMBOL(tcp_v4_connect);
+EXPORT_SYMBOL(tcp_v4_do_rcv);
+EXPORT_SYMBOL(tcp_v4_remember_stamp);
+EXPORT_SYMBOL(tcp_v4_send_check);
+EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
+
+#ifdef CONFIG_PROC_FS
+EXPORT_SYMBOL(tcp_proc_register);
+EXPORT_SYMBOL(tcp_proc_unregister);
+#endif
+EXPORT_SYMBOL(sysctl_tcp_low_latency);
+
diff --git a/net/ipv4/tcp_lp.c b/net/ipv4/tcp_lp.c
new file mode 100644
index 0000000..ce3c41f
--- /dev/null
+++ b/net/ipv4/tcp_lp.c
@@ -0,0 +1,344 @@
+/*
+ * TCP Low Priority (TCP-LP)
+ *
+ * TCP Low Priority is a distributed algorithm whose goal is to utilize only
+ *   the excess network bandwidth as compared to the ``fair share`` of
+ *   bandwidth as targeted by TCP.
+ *
+ * As of 2.6.13, Linux supports pluggable congestion control algorithms.
+ * Due to the limitation of the API, we take the following changes from
+ * the original TCP-LP implementation:
+ *   o We use newReno in most core CA handling. Only add some checking
+ *     within cong_avoid.
+ *   o Error correcting in remote HZ, therefore remote HZ will be keeped
+ *     on checking and updating.
+ *   o Handling calculation of One-Way-Delay (OWD) within rtt_sample, sicne
+ *     OWD have a similar meaning as RTT. Also correct the buggy formular.
+ *   o Handle reaction for Early Congestion Indication (ECI) within
+ *     pkts_acked, as mentioned within pseudo code.
+ *   o OWD is handled in relative format, where local time stamp will in
+ *     tcp_time_stamp format.
+ *
+ * Original Author:
+ *   Aleksandar Kuzmanovic <akuzma@northwestern.edu>
+ * Available from:
+ *   http://www.ece.rice.edu/~akuzma/Doc/akuzma/TCP-LP.pdf
+ * Original implementation for 2.4.19:
+ *   http://www-ece.rice.edu/networks/TCP-LP/
+ *
+ * 2.6.x module Authors:
+ *   Wong Hoi Sing, Edison <hswong3i@gmail.com>
+ *   Hung Hing Lun, Mike <hlhung3i@gmail.com>
+ * SourceForge project page:
+ *   http://tcp-lp-mod.sourceforge.net/
+ */
+
+#include <linux/module.h>
+#include <net/tcp.h>
+
+/* resolution of owd */
+#define LP_RESOL       1000
+
+/**
+ * enum tcp_lp_state
+ * @LP_VALID_RHZ: is remote HZ valid?
+ * @LP_VALID_OWD: is OWD valid?
+ * @LP_WITHIN_THR: are we within threshold?
+ * @LP_WITHIN_INF: are we within inference?
+ *
+ * TCP-LP's state flags.
+ * We create this set of state flag mainly for debugging.
+ */
+enum tcp_lp_state {
+	LP_VALID_RHZ = (1 << 0),
+	LP_VALID_OWD = (1 << 1),
+	LP_WITHIN_THR = (1 << 3),
+	LP_WITHIN_INF = (1 << 4),
+};
+
+/**
+ * struct lp
+ * @flag: TCP-LP state flag
+ * @sowd: smoothed OWD << 3
+ * @owd_min: min OWD
+ * @owd_max: max OWD
+ * @owd_max_rsv: resrved max owd
+ * @remote_hz: estimated remote HZ
+ * @remote_ref_time: remote reference time
+ * @local_ref_time: local reference time
+ * @last_drop: time for last active drop
+ * @inference: current inference
+ *
+ * TCP-LP's private struct.
+ * We get the idea from original TCP-LP implementation where only left those we
+ * found are really useful.
+ */
+struct lp {
+	u32 flag;
+	u32 sowd;
+	u32 owd_min;
+	u32 owd_max;
+	u32 owd_max_rsv;
+	u32 remote_hz;
+	u32 remote_ref_time;
+	u32 local_ref_time;
+	u32 last_drop;
+	u32 inference;
+};
+
+/**
+ * tcp_lp_init
+ *
+ * Init all required variables.
+ * Clone the handling from Vegas module implementation.
+ */
+static void tcp_lp_init(struct sock *sk)
+{
+	struct lp *lp = inet_csk_ca(sk);
+
+	lp->flag = 0;
+	lp->sowd = 0;
+	lp->owd_min = 0xffffffff;
+	lp->owd_max = 0;
+	lp->owd_max_rsv = 0;
+	lp->remote_hz = 0;
+	lp->remote_ref_time = 0;
+	lp->local_ref_time = 0;
+	lp->last_drop = 0;
+	lp->inference = 0;
+}
+
+/**
+ * tcp_lp_cong_avoid
+ *
+ * Implementation of cong_avoid.
+ * Will only call newReno CA when away from inference.
+ * From TCP-LP's paper, this will be handled in additive increasement.
+ */
+static void tcp_lp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct lp *lp = inet_csk_ca(sk);
+
+	if (!(lp->flag & LP_WITHIN_INF))
+		tcp_reno_cong_avoid(sk, ack, in_flight);
+}
+
+/**
+ * tcp_lp_remote_hz_estimator
+ *
+ * Estimate remote HZ.
+ * We keep on updating the estimated value, where original TCP-LP
+ * implementation only guest it for once and use forever.
+ */
+static u32 tcp_lp_remote_hz_estimator(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct lp *lp = inet_csk_ca(sk);
+	s64 rhz = lp->remote_hz << 6;	/* remote HZ << 6 */
+	s64 m = 0;
+
+	/* not yet record reference time
+	 * go away!! record it before come back!! */
+	if (lp->remote_ref_time == 0 || lp->local_ref_time == 0)
+		goto out;
+
+	/* we can't calc remote HZ with no different!! */
+	if (tp->rx_opt.rcv_tsval == lp->remote_ref_time
+	    || tp->rx_opt.rcv_tsecr == lp->local_ref_time)
+		goto out;
+
+	m = HZ * (tp->rx_opt.rcv_tsval -
+		  lp->remote_ref_time) / (tp->rx_opt.rcv_tsecr -
+					  lp->local_ref_time);
+	if (m < 0)
+		m = -m;
+
+	if (rhz > 0) {
+		m -= rhz >> 6;	/* m is now error in remote HZ est */
+		rhz += m;	/* 63/64 old + 1/64 new */
+	} else
+		rhz = m << 6;
+
+ out:
+	/* record time for successful remote HZ calc */
+	if ((rhz >> 6) > 0)
+		lp->flag |= LP_VALID_RHZ;
+	else
+		lp->flag &= ~LP_VALID_RHZ;
+
+	/* record reference time stamp */
+	lp->remote_ref_time = tp->rx_opt.rcv_tsval;
+	lp->local_ref_time = tp->rx_opt.rcv_tsecr;
+
+	return rhz >> 6;
+}
+
+/**
+ * tcp_lp_owd_calculator
+ *
+ * Calculate one way delay (in relative format).
+ * Original implement OWD as minus of remote time difference to local time
+ * difference directly. As this time difference just simply equal to RTT, when
+ * the network status is stable, remote RTT will equal to local RTT, and result
+ * OWD into zero.
+ * It seems to be a bug and so we fixed it.
+ */
+static u32 tcp_lp_owd_calculator(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct lp *lp = inet_csk_ca(sk);
+	s64 owd = 0;
+
+	lp->remote_hz = tcp_lp_remote_hz_estimator(sk);
+
+	if (lp->flag & LP_VALID_RHZ) {
+		owd =
+		    tp->rx_opt.rcv_tsval * (LP_RESOL / lp->remote_hz) -
+		    tp->rx_opt.rcv_tsecr * (LP_RESOL / HZ);
+		if (owd < 0)
+			owd = -owd;
+	}
+
+	if (owd > 0)
+		lp->flag |= LP_VALID_OWD;
+	else
+		lp->flag &= ~LP_VALID_OWD;
+
+	return owd;
+}
+
+/**
+ * tcp_lp_rtt_sample
+ *
+ * Implementation or rtt_sample.
+ * Will take the following action,
+ *   1. calc OWD,
+ *   2. record the min/max OWD,
+ *   3. calc smoothed OWD (SOWD).
+ * Most ideas come from the original TCP-LP implementation.
+ */
+static void tcp_lp_rtt_sample(struct sock *sk, u32 rtt)
+{
+	struct lp *lp = inet_csk_ca(sk);
+	s64 mowd = tcp_lp_owd_calculator(sk);
+
+	/* sorry that we don't have valid data */
+	if (!(lp->flag & LP_VALID_RHZ) || !(lp->flag & LP_VALID_OWD))
+		return;
+
+	/* record the next min owd */
+	if (mowd < lp->owd_min)
+		lp->owd_min = mowd;
+
+	/* always forget the max of the max
+	 * we just set owd_max as one below it */
+	if (mowd > lp->owd_max) {
+		if (mowd > lp->owd_max_rsv) {
+			if (lp->owd_max_rsv == 0)
+				lp->owd_max = mowd;
+			else
+				lp->owd_max = lp->owd_max_rsv;
+			lp->owd_max_rsv = mowd;
+		} else
+			lp->owd_max = mowd;
+	}
+
+	/* calc for smoothed owd */
+	if (lp->sowd != 0) {
+		mowd -= lp->sowd >> 3;	/* m is now error in owd est */
+		lp->sowd += mowd;	/* owd = 7/8 owd + 1/8 new */
+	} else
+		lp->sowd = mowd << 3;	/* take the measured time be owd */
+}
+
+/**
+ * tcp_lp_pkts_acked
+ *
+ * Implementation of pkts_acked.
+ * Deal with active drop under Early Congestion Indication.
+ * Only drop to half and 1 will be handle, because we hope to use back
+ * newReno in increase case.
+ * We work it out by following the idea from TCP-LP's paper directly
+ */
+static void tcp_lp_pkts_acked(struct sock *sk, u32 num_acked, s32 rtt_us)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct lp *lp = inet_csk_ca(sk);
+
+	if (rtt_us > 0)
+		tcp_lp_rtt_sample(sk, rtt_us);
+
+	/* calc inference */
+	if (tcp_time_stamp > tp->rx_opt.rcv_tsecr)
+		lp->inference = 3 * (tcp_time_stamp - tp->rx_opt.rcv_tsecr);
+
+	/* test if within inference */
+	if (lp->last_drop && (tcp_time_stamp - lp->last_drop < lp->inference))
+		lp->flag |= LP_WITHIN_INF;
+	else
+		lp->flag &= ~LP_WITHIN_INF;
+
+	/* test if within threshold */
+	if (lp->sowd >> 3 <
+	    lp->owd_min + 15 * (lp->owd_max - lp->owd_min) / 100)
+		lp->flag |= LP_WITHIN_THR;
+	else
+		lp->flag &= ~LP_WITHIN_THR;
+
+	pr_debug("TCP-LP: %05o|%5u|%5u|%15u|%15u|%15u\n", lp->flag,
+		 tp->snd_cwnd, lp->remote_hz, lp->owd_min, lp->owd_max,
+		 lp->sowd >> 3);
+
+	if (lp->flag & LP_WITHIN_THR)
+		return;
+
+	/* FIXME: try to reset owd_min and owd_max here
+	 * so decrease the chance the min/max is no longer suitable
+	 * and will usually within threshold when whithin inference */
+	lp->owd_min = lp->sowd >> 3;
+	lp->owd_max = lp->sowd >> 2;
+	lp->owd_max_rsv = lp->sowd >> 2;
+
+	/* happened within inference
+	 * drop snd_cwnd into 1 */
+	if (lp->flag & LP_WITHIN_INF)
+		tp->snd_cwnd = 1U;
+
+	/* happened after inference
+	 * cut snd_cwnd into half */
+	else
+		tp->snd_cwnd = max(tp->snd_cwnd >> 1U, 1U);
+
+	/* record this drop time */
+	lp->last_drop = tcp_time_stamp;
+}
+
+static struct tcp_congestion_ops tcp_lp = {
+	.flags = TCP_CONG_RTT_STAMP,
+	.init = tcp_lp_init,
+	.ssthresh = tcp_reno_ssthresh,
+	.cong_avoid = tcp_lp_cong_avoid,
+	.min_cwnd = tcp_reno_min_cwnd,
+	.pkts_acked = tcp_lp_pkts_acked,
+
+	.owner = THIS_MODULE,
+	.name = "lp"
+};
+
+static int __init tcp_lp_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct lp) > ICSK_CA_PRIV_SIZE);
+	return tcp_register_congestion_control(&tcp_lp);
+}
+
+static void __exit tcp_lp_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_lp);
+}
+
+module_init(tcp_lp_register);
+module_exit(tcp_lp_unregister);
+
+MODULE_AUTHOR("Wong Hoi Sing Edison, Hung Hing Lun Mike");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Low Priority");
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
new file mode 100644
index 0000000..779f2e9
--- /dev/null
+++ b/net/ipv4/tcp_minisocks.c
@@ -0,0 +1,739 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *		Corey Minyard <wf-rch!minyard@relay.EU.net>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ *		Linus Torvalds, <torvalds@cs.helsinki.fi>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Matthew Dillon, <dillon@apollo.west.oic.com>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <linux/workqueue.h>
+#include <net/tcp.h>
+#include <net/inet_common.h>
+#include <net/xfrm.h>
+
+#ifdef CONFIG_SYSCTL
+#define SYNC_INIT 0 /* let the user enable it */
+#else
+#define SYNC_INIT 1
+#endif
+
+int sysctl_tcp_syncookies __read_mostly = SYNC_INIT;
+EXPORT_SYMBOL(sysctl_tcp_syncookies);
+
+int sysctl_tcp_abort_on_overflow __read_mostly;
+
+struct inet_timewait_death_row tcp_death_row = {
+	.sysctl_max_tw_buckets = NR_FILE * 2,
+	.period		= TCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,
+	.death_lock	= __SPIN_LOCK_UNLOCKED(tcp_death_row.death_lock),
+	.hashinfo	= &tcp_hashinfo,
+	.tw_timer	= TIMER_INITIALIZER(inet_twdr_hangman, 0,
+					    (unsigned long)&tcp_death_row),
+	.twkill_work	= __WORK_INITIALIZER(tcp_death_row.twkill_work,
+					     inet_twdr_twkill_work),
+/* Short-time timewait calendar */
+
+	.twcal_hand	= -1,
+	.twcal_timer	= TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
+					    (unsigned long)&tcp_death_row),
+};
+
+EXPORT_SYMBOL_GPL(tcp_death_row);
+
+static __inline__ int tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win)
+{
+	if (seq == s_win)
+		return 1;
+	if (after(end_seq, s_win) && before(seq, e_win))
+		return 1;
+	return (seq == e_win && seq == end_seq);
+}
+
+/*
+ * * Main purpose of TIME-WAIT state is to close connection gracefully,
+ *   when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
+ *   (and, probably, tail of data) and one or more our ACKs are lost.
+ * * What is TIME-WAIT timeout? It is associated with maximal packet
+ *   lifetime in the internet, which results in wrong conclusion, that
+ *   it is set to catch "old duplicate segments" wandering out of their path.
+ *   It is not quite correct. This timeout is calculated so that it exceeds
+ *   maximal retransmission timeout enough to allow to lose one (or more)
+ *   segments sent by peer and our ACKs. This time may be calculated from RTO.
+ * * When TIME-WAIT socket receives RST, it means that another end
+ *   finally closed and we are allowed to kill TIME-WAIT too.
+ * * Second purpose of TIME-WAIT is catching old duplicate segments.
+ *   Well, certainly it is pure paranoia, but if we load TIME-WAIT
+ *   with this semantics, we MUST NOT kill TIME-WAIT state with RSTs.
+ * * If we invented some more clever way to catch duplicates
+ *   (f.e. based on PAWS), we could truncate TIME-WAIT to several RTOs.
+ *
+ * The algorithm below is based on FORMAL INTERPRETATION of RFCs.
+ * When you compare it to RFCs, please, read section SEGMENT ARRIVES
+ * from the very beginning.
+ *
+ * NOTE. With recycling (and later with fin-wait-2) TW bucket
+ * is _not_ stateless. It means, that strictly speaking we must
+ * spinlock it. I do not want! Well, probability of misbehaviour
+ * is ridiculously low and, seems, we could use some mb() tricks
+ * to avoid misread sequence numbers, states etc.  --ANK
+ */
+enum tcp_tw_status
+tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
+			   const struct tcphdr *th)
+{
+	struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
+	struct tcp_options_received tmp_opt;
+	int paws_reject = 0;
+
+	tmp_opt.saw_tstamp = 0;
+	if (th->doff > (sizeof(*th) >> 2) && tcptw->tw_ts_recent_stamp) {
+		tcp_parse_options(skb, &tmp_opt, 0);
+
+		if (tmp_opt.saw_tstamp) {
+			tmp_opt.ts_recent	= tcptw->tw_ts_recent;
+			tmp_opt.ts_recent_stamp	= tcptw->tw_ts_recent_stamp;
+			paws_reject = tcp_paws_check(&tmp_opt, th->rst);
+		}
+	}
+
+	if (tw->tw_substate == TCP_FIN_WAIT2) {
+		/* Just repeat all the checks of tcp_rcv_state_process() */
+
+		/* Out of window, send ACK */
+		if (paws_reject ||
+		    !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
+				   tcptw->tw_rcv_nxt,
+				   tcptw->tw_rcv_nxt + tcptw->tw_rcv_wnd))
+			return TCP_TW_ACK;
+
+		if (th->rst)
+			goto kill;
+
+		if (th->syn && !before(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt))
+			goto kill_with_rst;
+
+		/* Dup ACK? */
+		if (!after(TCP_SKB_CB(skb)->end_seq, tcptw->tw_rcv_nxt) ||
+		    TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) {
+			inet_twsk_put(tw);
+			return TCP_TW_SUCCESS;
+		}
+
+		/* New data or FIN. If new data arrive after half-duplex close,
+		 * reset.
+		 */
+		if (!th->fin ||
+		    TCP_SKB_CB(skb)->end_seq != tcptw->tw_rcv_nxt + 1) {
+kill_with_rst:
+			inet_twsk_deschedule(tw, &tcp_death_row);
+			inet_twsk_put(tw);
+			return TCP_TW_RST;
+		}
+
+		/* FIN arrived, enter true time-wait state. */
+		tw->tw_substate	  = TCP_TIME_WAIT;
+		tcptw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
+		if (tmp_opt.saw_tstamp) {
+			tcptw->tw_ts_recent_stamp = get_seconds();
+			tcptw->tw_ts_recent	  = tmp_opt.rcv_tsval;
+		}
+
+		/* I am shamed, but failed to make it more elegant.
+		 * Yes, it is direct reference to IP, which is impossible
+		 * to generalize to IPv6. Taking into account that IPv6
+		 * do not understand recycling in any case, it not
+		 * a big problem in practice. --ANK */
+		if (tw->tw_family == AF_INET &&
+		    tcp_death_row.sysctl_tw_recycle && tcptw->tw_ts_recent_stamp &&
+		    tcp_v4_tw_remember_stamp(tw))
+			inet_twsk_schedule(tw, &tcp_death_row, tw->tw_timeout,
+					   TCP_TIMEWAIT_LEN);
+		else
+			inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
+					   TCP_TIMEWAIT_LEN);
+		return TCP_TW_ACK;
+	}
+
+	/*
+	 *	Now real TIME-WAIT state.
+	 *
+	 *	RFC 1122:
+	 *	"When a connection is [...] on TIME-WAIT state [...]
+	 *	[a TCP] MAY accept a new SYN from the remote TCP to
+	 *	reopen the connection directly, if it:
+	 *
+	 *	(1)  assigns its initial sequence number for the new
+	 *	connection to be larger than the largest sequence
+	 *	number it used on the previous connection incarnation,
+	 *	and
+	 *
+	 *	(2)  returns to TIME-WAIT state if the SYN turns out
+	 *	to be an old duplicate".
+	 */
+
+	if (!paws_reject &&
+	    (TCP_SKB_CB(skb)->seq == tcptw->tw_rcv_nxt &&
+	     (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq || th->rst))) {
+		/* In window segment, it may be only reset or bare ack. */
+
+		if (th->rst) {
+			/* This is TIME_WAIT assassination, in two flavors.
+			 * Oh well... nobody has a sufficient solution to this
+			 * protocol bug yet.
+			 */
+			if (sysctl_tcp_rfc1337 == 0) {
+kill:
+				inet_twsk_deschedule(tw, &tcp_death_row);
+				inet_twsk_put(tw);
+				return TCP_TW_SUCCESS;
+			}
+		}
+		inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
+				   TCP_TIMEWAIT_LEN);
+
+		if (tmp_opt.saw_tstamp) {
+			tcptw->tw_ts_recent	  = tmp_opt.rcv_tsval;
+			tcptw->tw_ts_recent_stamp = get_seconds();
+		}
+
+		inet_twsk_put(tw);
+		return TCP_TW_SUCCESS;
+	}
+
+	/* Out of window segment.
+
+	   All the segments are ACKed immediately.
+
+	   The only exception is new SYN. We accept it, if it is
+	   not old duplicate and we are not in danger to be killed
+	   by delayed old duplicates. RFC check is that it has
+	   newer sequence number works at rates <40Mbit/sec.
+	   However, if paws works, it is reliable AND even more,
+	   we even may relax silly seq space cutoff.
+
+	   RED-PEN: we violate main RFC requirement, if this SYN will appear
+	   old duplicate (i.e. we receive RST in reply to SYN-ACK),
+	   we must return socket to time-wait state. It is not good,
+	   but not fatal yet.
+	 */
+
+	if (th->syn && !th->rst && !th->ack && !paws_reject &&
+	    (after(TCP_SKB_CB(skb)->seq, tcptw->tw_rcv_nxt) ||
+	     (tmp_opt.saw_tstamp &&
+	      (s32)(tcptw->tw_ts_recent - tmp_opt.rcv_tsval) < 0))) {
+		u32 isn = tcptw->tw_snd_nxt + 65535 + 2;
+		if (isn == 0)
+			isn++;
+		TCP_SKB_CB(skb)->when = isn;
+		return TCP_TW_SYN;
+	}
+
+	if (paws_reject)
+		NET_INC_STATS_BH(twsk_net(tw), LINUX_MIB_PAWSESTABREJECTED);
+
+	if (!th->rst) {
+		/* In this case we must reset the TIMEWAIT timer.
+		 *
+		 * If it is ACKless SYN it may be both old duplicate
+		 * and new good SYN with random sequence number <rcv_nxt.
+		 * Do not reschedule in the last case.
+		 */
+		if (paws_reject || th->ack)
+			inet_twsk_schedule(tw, &tcp_death_row, TCP_TIMEWAIT_LEN,
+					   TCP_TIMEWAIT_LEN);
+
+		/* Send ACK. Note, we do not put the bucket,
+		 * it will be released by caller.
+		 */
+		return TCP_TW_ACK;
+	}
+	inet_twsk_put(tw);
+	return TCP_TW_SUCCESS;
+}
+
+/*
+ * Move a socket to time-wait or dead fin-wait-2 state.
+ */
+void tcp_time_wait(struct sock *sk, int state, int timeo)
+{
+	struct inet_timewait_sock *tw = NULL;
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	const struct tcp_sock *tp = tcp_sk(sk);
+	int recycle_ok = 0;
+
+	if (tcp_death_row.sysctl_tw_recycle && tp->rx_opt.ts_recent_stamp)
+		recycle_ok = icsk->icsk_af_ops->remember_stamp(sk);
+
+	if (tcp_death_row.tw_count < tcp_death_row.sysctl_max_tw_buckets)
+		tw = inet_twsk_alloc(sk, state);
+
+	if (tw != NULL) {
+		struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
+		const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
+
+		tw->tw_rcv_wscale	= tp->rx_opt.rcv_wscale;
+		tcptw->tw_rcv_nxt	= tp->rcv_nxt;
+		tcptw->tw_snd_nxt	= tp->snd_nxt;
+		tcptw->tw_rcv_wnd	= tcp_receive_window(tp);
+		tcptw->tw_ts_recent	= tp->rx_opt.ts_recent;
+		tcptw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+		if (tw->tw_family == PF_INET6) {
+			struct ipv6_pinfo *np = inet6_sk(sk);
+			struct inet6_timewait_sock *tw6;
+
+			tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);
+			tw6 = inet6_twsk((struct sock *)tw);
+			ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);
+			ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);
+			tw->tw_ipv6only = np->ipv6only;
+		}
+#endif
+
+#ifdef CONFIG_TCP_MD5SIG
+		/*
+		 * The timewait bucket does not have the key DB from the
+		 * sock structure. We just make a quick copy of the
+		 * md5 key being used (if indeed we are using one)
+		 * so the timewait ack generating code has the key.
+		 */
+		do {
+			struct tcp_md5sig_key *key;
+			memset(tcptw->tw_md5_key, 0, sizeof(tcptw->tw_md5_key));
+			tcptw->tw_md5_keylen = 0;
+			key = tp->af_specific->md5_lookup(sk, sk);
+			if (key != NULL) {
+				memcpy(&tcptw->tw_md5_key, key->key, key->keylen);
+				tcptw->tw_md5_keylen = key->keylen;
+				if (tcp_alloc_md5sig_pool() == NULL)
+					BUG();
+			}
+		} while (0);
+#endif
+
+		/* Linkage updates. */
+		__inet_twsk_hashdance(tw, sk, &tcp_hashinfo);
+
+		/* Get the TIME_WAIT timeout firing. */
+		if (timeo < rto)
+			timeo = rto;
+
+		if (recycle_ok) {
+			tw->tw_timeout = rto;
+		} else {
+			tw->tw_timeout = TCP_TIMEWAIT_LEN;
+			if (state == TCP_TIME_WAIT)
+				timeo = TCP_TIMEWAIT_LEN;
+		}
+
+		inet_twsk_schedule(tw, &tcp_death_row, timeo,
+				   TCP_TIMEWAIT_LEN);
+		inet_twsk_put(tw);
+	} else {
+		/* Sorry, if we're out of memory, just CLOSE this
+		 * socket up.  We've got bigger problems than
+		 * non-graceful socket closings.
+		 */
+		LIMIT_NETDEBUG(KERN_INFO "TCP: time wait bucket table overflow\n");
+	}
+
+	tcp_update_metrics(sk);
+	tcp_done(sk);
+}
+
+void tcp_twsk_destructor(struct sock *sk)
+{
+#ifdef CONFIG_TCP_MD5SIG
+	struct tcp_timewait_sock *twsk = tcp_twsk(sk);
+	if (twsk->tw_md5_keylen)
+		tcp_put_md5sig_pool();
+#endif
+}
+
+EXPORT_SYMBOL_GPL(tcp_twsk_destructor);
+
+static inline void TCP_ECN_openreq_child(struct tcp_sock *tp,
+					 struct request_sock *req)
+{
+	tp->ecn_flags = inet_rsk(req)->ecn_ok ? TCP_ECN_OK : 0;
+}
+
+/* This is not only more efficient than what we used to do, it eliminates
+ * a lot of code duplication between IPv4/IPv6 SYN recv processing. -DaveM
+ *
+ * Actually, we could lots of memory writes here. tp of listening
+ * socket contains all necessary default parameters.
+ */
+struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, struct sk_buff *skb)
+{
+	struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);
+
+	if (newsk != NULL) {
+		const struct inet_request_sock *ireq = inet_rsk(req);
+		struct tcp_request_sock *treq = tcp_rsk(req);
+		struct inet_connection_sock *newicsk = inet_csk(newsk);
+		struct tcp_sock *newtp;
+
+		/* Now setup tcp_sock */
+		newtp = tcp_sk(newsk);
+		newtp->pred_flags = 0;
+		newtp->rcv_wup = newtp->copied_seq = newtp->rcv_nxt = treq->rcv_isn + 1;
+		newtp->snd_sml = newtp->snd_una = newtp->snd_nxt = treq->snt_isn + 1;
+		newtp->snd_up = treq->snt_isn + 1;
+
+		tcp_prequeue_init(newtp);
+
+		tcp_init_wl(newtp, treq->snt_isn, treq->rcv_isn);
+
+		newtp->srtt = 0;
+		newtp->mdev = TCP_TIMEOUT_INIT;
+		newicsk->icsk_rto = TCP_TIMEOUT_INIT;
+
+		newtp->packets_out = 0;
+		newtp->retrans_out = 0;
+		newtp->sacked_out = 0;
+		newtp->fackets_out = 0;
+		newtp->snd_ssthresh = 0x7fffffff;
+
+		/* So many TCP implementations out there (incorrectly) count the
+		 * initial SYN frame in their delayed-ACK and congestion control
+		 * algorithms that we must have the following bandaid to talk
+		 * efficiently to them.  -DaveM
+		 */
+		newtp->snd_cwnd = 2;
+		newtp->snd_cwnd_cnt = 0;
+		newtp->bytes_acked = 0;
+
+		newtp->frto_counter = 0;
+		newtp->frto_highmark = 0;
+
+		newicsk->icsk_ca_ops = &tcp_init_congestion_ops;
+
+		tcp_set_ca_state(newsk, TCP_CA_Open);
+		tcp_init_xmit_timers(newsk);
+		skb_queue_head_init(&newtp->out_of_order_queue);
+		newtp->write_seq = treq->snt_isn + 1;
+		newtp->pushed_seq = newtp->write_seq;
+
+		newtp->rx_opt.saw_tstamp = 0;
+
+		newtp->rx_opt.dsack = 0;
+		newtp->rx_opt.eff_sacks = 0;
+
+		newtp->rx_opt.num_sacks = 0;
+		newtp->urg_data = 0;
+
+		if (sock_flag(newsk, SOCK_KEEPOPEN))
+			inet_csk_reset_keepalive_timer(newsk,
+						       keepalive_time_when(newtp));
+
+		newtp->rx_opt.tstamp_ok = ireq->tstamp_ok;
+		if ((newtp->rx_opt.sack_ok = ireq->sack_ok) != 0) {
+			if (sysctl_tcp_fack)
+				tcp_enable_fack(newtp);
+		}
+		newtp->window_clamp = req->window_clamp;
+		newtp->rcv_ssthresh = req->rcv_wnd;
+		newtp->rcv_wnd = req->rcv_wnd;
+		newtp->rx_opt.wscale_ok = ireq->wscale_ok;
+		if (newtp->rx_opt.wscale_ok) {
+			newtp->rx_opt.snd_wscale = ireq->snd_wscale;
+			newtp->rx_opt.rcv_wscale = ireq->rcv_wscale;
+		} else {
+			newtp->rx_opt.snd_wscale = newtp->rx_opt.rcv_wscale = 0;
+			newtp->window_clamp = min(newtp->window_clamp, 65535U);
+		}
+		newtp->snd_wnd = (ntohs(tcp_hdr(skb)->window) <<
+				  newtp->rx_opt.snd_wscale);
+		newtp->max_window = newtp->snd_wnd;
+
+		if (newtp->rx_opt.tstamp_ok) {
+			newtp->rx_opt.ts_recent = req->ts_recent;
+			newtp->rx_opt.ts_recent_stamp = get_seconds();
+			newtp->tcp_header_len = sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;
+		} else {
+			newtp->rx_opt.ts_recent_stamp = 0;
+			newtp->tcp_header_len = sizeof(struct tcphdr);
+		}
+#ifdef CONFIG_TCP_MD5SIG
+		newtp->md5sig_info = NULL;	/*XXX*/
+		if (newtp->af_specific->md5_lookup(sk, newsk))
+			newtp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+		if (skb->len >= TCP_MIN_RCVMSS+newtp->tcp_header_len)
+			newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len;
+		newtp->rx_opt.mss_clamp = req->mss;
+		TCP_ECN_openreq_child(newtp, req);
+
+		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_PASSIVEOPENS);
+	}
+	return newsk;
+}
+
+/*
+ *	Process an incoming packet for SYN_RECV sockets represented
+ *	as a request_sock.
+ */
+
+struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
+			   struct request_sock *req,
+			   struct request_sock **prev)
+{
+	const struct tcphdr *th = tcp_hdr(skb);
+	__be32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK);
+	int paws_reject = 0;
+	struct tcp_options_received tmp_opt;
+	struct sock *child;
+
+	tmp_opt.saw_tstamp = 0;
+	if (th->doff > (sizeof(struct tcphdr)>>2)) {
+		tcp_parse_options(skb, &tmp_opt, 0);
+
+		if (tmp_opt.saw_tstamp) {
+			tmp_opt.ts_recent = req->ts_recent;
+			/* We do not store true stamp, but it is not required,
+			 * it can be estimated (approximately)
+			 * from another data.
+			 */
+			tmp_opt.ts_recent_stamp = get_seconds() - ((TCP_TIMEOUT_INIT/HZ)<<req->retrans);
+			paws_reject = tcp_paws_check(&tmp_opt, th->rst);
+		}
+	}
+
+	/* Check for pure retransmitted SYN. */
+	if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn &&
+	    flg == TCP_FLAG_SYN &&
+	    !paws_reject) {
+		/*
+		 * RFC793 draws (Incorrectly! It was fixed in RFC1122)
+		 * this case on figure 6 and figure 8, but formal
+		 * protocol description says NOTHING.
+		 * To be more exact, it says that we should send ACK,
+		 * because this segment (at least, if it has no data)
+		 * is out of window.
+		 *
+		 *  CONCLUSION: RFC793 (even with RFC1122) DOES NOT
+		 *  describe SYN-RECV state. All the description
+		 *  is wrong, we cannot believe to it and should
+		 *  rely only on common sense and implementation
+		 *  experience.
+		 *
+		 * Enforce "SYN-ACK" according to figure 8, figure 6
+		 * of RFC793, fixed by RFC1122.
+		 */
+		req->rsk_ops->rtx_syn_ack(sk, req);
+		return NULL;
+	}
+
+	/* Further reproduces section "SEGMENT ARRIVES"
+	   for state SYN-RECEIVED of RFC793.
+	   It is broken, however, it does not work only
+	   when SYNs are crossed.
+
+	   You would think that SYN crossing is impossible here, since
+	   we should have a SYN_SENT socket (from connect()) on our end,
+	   but this is not true if the crossed SYNs were sent to both
+	   ends by a malicious third party.  We must defend against this,
+	   and to do that we first verify the ACK (as per RFC793, page
+	   36) and reset if it is invalid.  Is this a true full defense?
+	   To convince ourselves, let us consider a way in which the ACK
+	   test can still pass in this 'malicious crossed SYNs' case.
+	   Malicious sender sends identical SYNs (and thus identical sequence
+	   numbers) to both A and B:
+
+		A: gets SYN, seq=7
+		B: gets SYN, seq=7
+
+	   By our good fortune, both A and B select the same initial
+	   send sequence number of seven :-)
+
+		A: sends SYN|ACK, seq=7, ack_seq=8
+		B: sends SYN|ACK, seq=7, ack_seq=8
+
+	   So we are now A eating this SYN|ACK, ACK test passes.  So
+	   does sequence test, SYN is truncated, and thus we consider
+	   it a bare ACK.
+
+	   If icsk->icsk_accept_queue.rskq_defer_accept, we silently drop this
+	   bare ACK.  Otherwise, we create an established connection.  Both
+	   ends (listening sockets) accept the new incoming connection and try
+	   to talk to each other. 8-)
+
+	   Note: This case is both harmless, and rare.  Possibility is about the
+	   same as us discovering intelligent life on another plant tomorrow.
+
+	   But generally, we should (RFC lies!) to accept ACK
+	   from SYNACK both here and in tcp_rcv_state_process().
+	   tcp_rcv_state_process() does not, hence, we do not too.
+
+	   Note that the case is absolutely generic:
+	   we cannot optimize anything here without
+	   violating protocol. All the checks must be made
+	   before attempt to create socket.
+	 */
+
+	/* RFC793 page 36: "If the connection is in any non-synchronized state ...
+	 *                  and the incoming segment acknowledges something not yet
+	 *                  sent (the segment carries an unacceptable ACK) ...
+	 *                  a reset is sent."
+	 *
+	 * Invalid ACK: reset will be sent by listening socket
+	 */
+	if ((flg & TCP_FLAG_ACK) &&
+	    (TCP_SKB_CB(skb)->ack_seq != tcp_rsk(req)->snt_isn + 1))
+		return sk;
+
+	/* Also, it would be not so bad idea to check rcv_tsecr, which
+	 * is essentially ACK extension and too early or too late values
+	 * should cause reset in unsynchronized states.
+	 */
+
+	/* RFC793: "first check sequence number". */
+
+	if (paws_reject || !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
+					  tcp_rsk(req)->rcv_isn + 1, tcp_rsk(req)->rcv_isn + 1 + req->rcv_wnd)) {
+		/* Out of window: send ACK and drop. */
+		if (!(flg & TCP_FLAG_RST))
+			req->rsk_ops->send_ack(sk, skb, req);
+		if (paws_reject)
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED);
+		return NULL;
+	}
+
+	/* In sequence, PAWS is OK. */
+
+	if (tmp_opt.saw_tstamp && !after(TCP_SKB_CB(skb)->seq, tcp_rsk(req)->rcv_isn + 1))
+		req->ts_recent = tmp_opt.rcv_tsval;
+
+	if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn) {
+		/* Truncate SYN, it is out of window starting
+		   at tcp_rsk(req)->rcv_isn + 1. */
+		flg &= ~TCP_FLAG_SYN;
+	}
+
+	/* RFC793: "second check the RST bit" and
+	 *	   "fourth, check the SYN bit"
+	 */
+	if (flg & (TCP_FLAG_RST|TCP_FLAG_SYN)) {
+		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
+		goto embryonic_reset;
+	}
+
+	/* ACK sequence verified above, just make sure ACK is
+	 * set.  If ACK not set, just silently drop the packet.
+	 */
+	if (!(flg & TCP_FLAG_ACK))
+		return NULL;
+
+	/* If TCP_DEFER_ACCEPT is set, drop bare ACK. */
+	if (inet_csk(sk)->icsk_accept_queue.rskq_defer_accept &&
+	    TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
+		inet_rsk(req)->acked = 1;
+		return NULL;
+	}
+
+	/* OK, ACK is valid, create big socket and
+	 * feed this segment to it. It will repeat all
+	 * the tests. THIS SEGMENT MUST MOVE SOCKET TO
+	 * ESTABLISHED STATE. If it will be dropped after
+	 * socket is created, wait for troubles.
+	 */
+	child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
+	if (child == NULL)
+		goto listen_overflow;
+#ifdef CONFIG_TCP_MD5SIG
+	else {
+		/* Copy over the MD5 key from the original socket */
+		struct tcp_md5sig_key *key;
+		struct tcp_sock *tp = tcp_sk(sk);
+		key = tp->af_specific->md5_lookup(sk, child);
+		if (key != NULL) {
+			/*
+			 * We're using one, so create a matching key on the
+			 * newsk structure. If we fail to get memory then we
+			 * end up not copying the key across. Shucks.
+			 */
+			char *newkey = kmemdup(key->key, key->keylen,
+					       GFP_ATOMIC);
+			if (newkey) {
+				if (!tcp_alloc_md5sig_pool())
+					BUG();
+				tp->af_specific->md5_add(child, child, newkey,
+							 key->keylen);
+			}
+		}
+	}
+#endif
+
+	inet_csk_reqsk_queue_unlink(sk, req, prev);
+	inet_csk_reqsk_queue_removed(sk, req);
+
+	inet_csk_reqsk_queue_add(sk, req, child);
+	return child;
+
+listen_overflow:
+	if (!sysctl_tcp_abort_on_overflow) {
+		inet_rsk(req)->acked = 1;
+		return NULL;
+	}
+
+embryonic_reset:
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_EMBRYONICRSTS);
+	if (!(flg & TCP_FLAG_RST))
+		req->rsk_ops->send_reset(sk, skb);
+
+	inet_csk_reqsk_queue_drop(sk, req, prev);
+	return NULL;
+}
+
+/*
+ * Queue segment on the new socket if the new socket is active,
+ * otherwise we just shortcircuit this and continue with
+ * the new socket.
+ */
+
+int tcp_child_process(struct sock *parent, struct sock *child,
+		      struct sk_buff *skb)
+{
+	int ret = 0;
+	int state = child->sk_state;
+
+	if (!sock_owned_by_user(child)) {
+		ret = tcp_rcv_state_process(child, skb, tcp_hdr(skb),
+					    skb->len);
+		/* Wakeup parent, send SIGIO */
+		if (state == TCP_SYN_RECV && child->sk_state != state)
+			parent->sk_data_ready(parent, 0);
+	} else {
+		/* Alas, it is possible again, because we do lookup
+		 * in main socket hash table and lock on listening
+		 * socket does not protect us more.
+		 */
+		sk_add_backlog(child, skb);
+	}
+
+	bh_unlock_sock(child);
+	sock_put(child);
+	return ret;
+}
+
+EXPORT_SYMBOL(tcp_check_req);
+EXPORT_SYMBOL(tcp_child_process);
+EXPORT_SYMBOL(tcp_create_openreq_child);
+EXPORT_SYMBOL(tcp_timewait_state_process);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
new file mode 100644
index 0000000..fe3b4bd
--- /dev/null
+++ b/net/ipv4/tcp_output.c
@@ -0,0 +1,2641 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *		Corey Minyard <wf-rch!minyard@relay.EU.net>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ *		Linus Torvalds, <torvalds@cs.helsinki.fi>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Matthew Dillon, <dillon@apollo.west.oic.com>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ */
+
+/*
+ * Changes:	Pedro Roque	:	Retransmit queue handled by TCP.
+ *				:	Fragmentation on mtu decrease
+ *				:	Segment collapse on retransmit
+ *				:	AF independence
+ *
+ *		Linus Torvalds	:	send_delayed_ack
+ *		David S. Miller	:	Charge memory using the right skb
+ *					during syn/ack processing.
+ *		David S. Miller :	Output engine completely rewritten.
+ *		Andrea Arcangeli:	SYNACK carry ts_recent in tsecr.
+ *		Cacophonix Gaul :	draft-minshall-nagle-01
+ *		J Hadi Salim	:	ECN support
+ *
+ */
+
+#include <net/tcp.h>
+
+#include <linux/compiler.h>
+#include <linux/module.h>
+
+/* People can turn this off for buggy TCP's found in printers etc. */
+int sysctl_tcp_retrans_collapse __read_mostly = 1;
+
+/* People can turn this on to  work with those rare, broken TCPs that
+ * interpret the window field as a signed quantity.
+ */
+int sysctl_tcp_workaround_signed_windows __read_mostly = 0;
+
+/* This limits the percentage of the congestion window which we
+ * will allow a single TSO frame to consume.  Building TSO frames
+ * which are too large can cause TCP streams to be bursty.
+ */
+int sysctl_tcp_tso_win_divisor __read_mostly = 3;
+
+int sysctl_tcp_mtu_probing __read_mostly = 0;
+int sysctl_tcp_base_mss __read_mostly = 512;
+
+/* By default, RFC2861 behavior.  */
+int sysctl_tcp_slow_start_after_idle __read_mostly = 1;
+
+static void tcp_event_new_data_sent(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned int prior_packets = tp->packets_out;
+
+	tcp_advance_send_head(sk, skb);
+	tp->snd_nxt = TCP_SKB_CB(skb)->end_seq;
+
+	/* Don't override Nagle indefinately with F-RTO */
+	if (tp->frto_counter == 2)
+		tp->frto_counter = 3;
+
+	tp->packets_out += tcp_skb_pcount(skb);
+	if (!prior_packets)
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+					  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
+}
+
+/* SND.NXT, if window was not shrunk.
+ * If window has been shrunk, what should we make? It is not clear at all.
+ * Using SND.UNA we will fail to open window, SND.NXT is out of window. :-(
+ * Anything in between SND.UNA...SND.UNA+SND.WND also can be already
+ * invalid. OK, let's make this for now:
+ */
+static inline __u32 tcp_acceptable_seq(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!before(tcp_wnd_end(tp), tp->snd_nxt))
+		return tp->snd_nxt;
+	else
+		return tcp_wnd_end(tp);
+}
+
+/* Calculate mss to advertise in SYN segment.
+ * RFC1122, RFC1063, draft-ietf-tcpimpl-pmtud-01 state that:
+ *
+ * 1. It is independent of path mtu.
+ * 2. Ideally, it is maximal possible segment size i.e. 65535-40.
+ * 3. For IPv4 it is reasonable to calculate it from maximal MTU of
+ *    attached devices, because some buggy hosts are confused by
+ *    large MSS.
+ * 4. We do not make 3, we advertise MSS, calculated from first
+ *    hop device mtu, but allow to raise it to ip_rt_min_advmss.
+ *    This may be overridden via information stored in routing table.
+ * 5. Value 65535 for MSS is valid in IPv6 and means "as large as possible,
+ *    probably even Jumbo".
+ */
+static __u16 tcp_advertise_mss(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct dst_entry *dst = __sk_dst_get(sk);
+	int mss = tp->advmss;
+
+	if (dst && dst_metric(dst, RTAX_ADVMSS) < mss) {
+		mss = dst_metric(dst, RTAX_ADVMSS);
+		tp->advmss = mss;
+	}
+
+	return (__u16)mss;
+}
+
+/* RFC2861. Reset CWND after idle period longer RTO to "restart window".
+ * This is the first part of cwnd validation mechanism. */
+static void tcp_cwnd_restart(struct sock *sk, struct dst_entry *dst)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	s32 delta = tcp_time_stamp - tp->lsndtime;
+	u32 restart_cwnd = tcp_init_cwnd(tp, dst);
+	u32 cwnd = tp->snd_cwnd;
+
+	tcp_ca_event(sk, CA_EVENT_CWND_RESTART);
+
+	tp->snd_ssthresh = tcp_current_ssthresh(sk);
+	restart_cwnd = min(restart_cwnd, cwnd);
+
+	while ((delta -= inet_csk(sk)->icsk_rto) > 0 && cwnd > restart_cwnd)
+		cwnd >>= 1;
+	tp->snd_cwnd = max(cwnd, restart_cwnd);
+	tp->snd_cwnd_stamp = tcp_time_stamp;
+	tp->snd_cwnd_used = 0;
+}
+
+static void tcp_event_data_sent(struct tcp_sock *tp,
+				struct sk_buff *skb, struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	const u32 now = tcp_time_stamp;
+
+	if (sysctl_tcp_slow_start_after_idle &&
+	    (!tp->packets_out && (s32)(now - tp->lsndtime) > icsk->icsk_rto))
+		tcp_cwnd_restart(sk, __sk_dst_get(sk));
+
+	tp->lsndtime = now;
+
+	/* If it is a reply for ato after last received
+	 * packet, enter pingpong mode.
+	 */
+	if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
+		icsk->icsk_ack.pingpong = 1;
+}
+
+static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
+{
+	tcp_dec_quickack_mode(sk, pkts);
+	inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
+}
+
+/* Determine a window scaling and initial window to offer.
+ * Based on the assumption that the given amount of space
+ * will be offered. Store the results in the tp structure.
+ * NOTE: for smooth operation initial space offering should
+ * be a multiple of mss if possible. We assume here that mss >= 1.
+ * This MUST be enforced by all callers.
+ */
+void tcp_select_initial_window(int __space, __u32 mss,
+			       __u32 *rcv_wnd, __u32 *window_clamp,
+			       int wscale_ok, __u8 *rcv_wscale)
+{
+	unsigned int space = (__space < 0 ? 0 : __space);
+
+	/* If no clamp set the clamp to the max possible scaled window */
+	if (*window_clamp == 0)
+		(*window_clamp) = (65535 << 14);
+	space = min(*window_clamp, space);
+
+	/* Quantize space offering to a multiple of mss if possible. */
+	if (space > mss)
+		space = (space / mss) * mss;
+
+	/* NOTE: offering an initial window larger than 32767
+	 * will break some buggy TCP stacks. If the admin tells us
+	 * it is likely we could be speaking with such a buggy stack
+	 * we will truncate our initial window offering to 32K-1
+	 * unless the remote has sent us a window scaling option,
+	 * which we interpret as a sign the remote TCP is not
+	 * misinterpreting the window field as a signed quantity.
+	 */
+	if (sysctl_tcp_workaround_signed_windows)
+		(*rcv_wnd) = min(space, MAX_TCP_WINDOW);
+	else
+		(*rcv_wnd) = space;
+
+	(*rcv_wscale) = 0;
+	if (wscale_ok) {
+		/* Set window scaling on max possible window
+		 * See RFC1323 for an explanation of the limit to 14
+		 */
+		space = max_t(u32, sysctl_tcp_rmem[2], sysctl_rmem_max);
+		space = min_t(u32, space, *window_clamp);
+		while (space > 65535 && (*rcv_wscale) < 14) {
+			space >>= 1;
+			(*rcv_wscale)++;
+		}
+	}
+
+	/* Set initial window to value enough for senders,
+	 * following RFC2414. Senders, not following this RFC,
+	 * will be satisfied with 2.
+	 */
+	if (mss > (1 << *rcv_wscale)) {
+		int init_cwnd = 4;
+		if (mss > 1460 * 3)
+			init_cwnd = 2;
+		else if (mss > 1460)
+			init_cwnd = 3;
+		if (*rcv_wnd > init_cwnd * mss)
+			*rcv_wnd = init_cwnd * mss;
+	}
+
+	/* Set the clamp no higher than max representable value */
+	(*window_clamp) = min(65535U << (*rcv_wscale), *window_clamp);
+}
+
+/* Chose a new window to advertise, update state in tcp_sock for the
+ * socket, and return result with RFC1323 scaling applied.  The return
+ * value can be stuffed directly into th->window for an outgoing
+ * frame.
+ */
+static u16 tcp_select_window(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 cur_win = tcp_receive_window(tp);
+	u32 new_win = __tcp_select_window(sk);
+
+	/* Never shrink the offered window */
+	if (new_win < cur_win) {
+		/* Danger Will Robinson!
+		 * Don't update rcv_wup/rcv_wnd here or else
+		 * we will not be able to advertise a zero
+		 * window in time.  --DaveM
+		 *
+		 * Relax Will Robinson.
+		 */
+		new_win = ALIGN(cur_win, 1 << tp->rx_opt.rcv_wscale);
+	}
+	tp->rcv_wnd = new_win;
+	tp->rcv_wup = tp->rcv_nxt;
+
+	/* Make sure we do not exceed the maximum possible
+	 * scaled window.
+	 */
+	if (!tp->rx_opt.rcv_wscale && sysctl_tcp_workaround_signed_windows)
+		new_win = min(new_win, MAX_TCP_WINDOW);
+	else
+		new_win = min(new_win, (65535U << tp->rx_opt.rcv_wscale));
+
+	/* RFC1323 scaling applied */
+	new_win >>= tp->rx_opt.rcv_wscale;
+
+	/* If we advertise zero window, disable fast path. */
+	if (new_win == 0)
+		tp->pred_flags = 0;
+
+	return new_win;
+}
+
+static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
+	if (!(tp->ecn_flags & TCP_ECN_OK))
+		TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
+}
+
+static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	tp->ecn_flags = 0;
+	if (sysctl_tcp_ecn) {
+		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE | TCPCB_FLAG_CWR;
+		tp->ecn_flags = TCP_ECN_OK;
+	}
+}
+
+static __inline__ void
+TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th)
+{
+	if (inet_rsk(req)->ecn_ok)
+		th->ece = 1;
+}
+
+static inline void TCP_ECN_send(struct sock *sk, struct sk_buff *skb,
+				int tcp_header_len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tp->ecn_flags & TCP_ECN_OK) {
+		/* Not-retransmitted data segment: set ECT and inject CWR. */
+		if (skb->len != tcp_header_len &&
+		    !before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) {
+			INET_ECN_xmit(sk);
+			if (tp->ecn_flags & TCP_ECN_QUEUE_CWR) {
+				tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR;
+				tcp_hdr(skb)->cwr = 1;
+				skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
+			}
+		} else {
+			/* ACK or retransmitted segment: clear ECT|CE */
+			INET_ECN_dontxmit(sk);
+		}
+		if (tp->ecn_flags & TCP_ECN_DEMAND_CWR)
+			tcp_hdr(skb)->ece = 1;
+	}
+}
+
+/* Constructs common control bits of non-data skb. If SYN/FIN is present,
+ * auto increment end seqno.
+ */
+static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
+{
+	skb->csum = 0;
+
+	TCP_SKB_CB(skb)->flags = flags;
+	TCP_SKB_CB(skb)->sacked = 0;
+
+	skb_shinfo(skb)->gso_segs = 1;
+	skb_shinfo(skb)->gso_size = 0;
+	skb_shinfo(skb)->gso_type = 0;
+
+	TCP_SKB_CB(skb)->seq = seq;
+	if (flags & (TCPCB_FLAG_SYN | TCPCB_FLAG_FIN))
+		seq++;
+	TCP_SKB_CB(skb)->end_seq = seq;
+}
+
+static inline int tcp_urg_mode(const struct tcp_sock *tp)
+{
+	return tp->snd_una != tp->snd_up;
+}
+
+#define OPTION_SACK_ADVERTISE	(1 << 0)
+#define OPTION_TS		(1 << 1)
+#define OPTION_MD5		(1 << 2)
+
+struct tcp_out_options {
+	u8 options;		/* bit field of OPTION_* */
+	u8 ws;			/* window scale, 0 to disable */
+	u8 num_sack_blocks;	/* number of SACK blocks to include */
+	u16 mss;		/* 0 to disable */
+	__u32 tsval, tsecr;	/* need to include OPTION_TS */
+};
+
+/* Beware: Something in the Internet is very sensitive to the ordering of
+ * TCP options, we learned this through the hard way, so be careful here.
+ * Luckily we can at least blame others for their non-compliance but from
+ * inter-operatibility perspective it seems that we're somewhat stuck with
+ * the ordering which we have been using if we want to keep working with
+ * those broken things (not that it currently hurts anybody as there isn't
+ * particular reason why the ordering would need to be changed).
+ *
+ * At least SACK_PERM as the first option is known to lead to a disaster
+ * (but it may well be that other scenarios fail similarly).
+ */
+static void tcp_options_write(__be32 *ptr, struct tcp_sock *tp,
+			      const struct tcp_out_options *opts,
+			      __u8 **md5_hash) {
+	if (unlikely(OPTION_MD5 & opts->options)) {
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_NOP << 16) |
+			       (TCPOPT_MD5SIG << 8) |
+			       TCPOLEN_MD5SIG);
+		*md5_hash = (__u8 *)ptr;
+		ptr += 4;
+	} else {
+		*md5_hash = NULL;
+	}
+
+	if (unlikely(opts->mss)) {
+		*ptr++ = htonl((TCPOPT_MSS << 24) |
+			       (TCPOLEN_MSS << 16) |
+			       opts->mss);
+	}
+
+	if (likely(OPTION_TS & opts->options)) {
+		if (unlikely(OPTION_SACK_ADVERTISE & opts->options)) {
+			*ptr++ = htonl((TCPOPT_SACK_PERM << 24) |
+				       (TCPOLEN_SACK_PERM << 16) |
+				       (TCPOPT_TIMESTAMP << 8) |
+				       TCPOLEN_TIMESTAMP);
+		} else {
+			*ptr++ = htonl((TCPOPT_NOP << 24) |
+				       (TCPOPT_NOP << 16) |
+				       (TCPOPT_TIMESTAMP << 8) |
+				       TCPOLEN_TIMESTAMP);
+		}
+		*ptr++ = htonl(opts->tsval);
+		*ptr++ = htonl(opts->tsecr);
+	}
+
+	if (unlikely(OPTION_SACK_ADVERTISE & opts->options &&
+		     !(OPTION_TS & opts->options))) {
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_NOP << 16) |
+			       (TCPOPT_SACK_PERM << 8) |
+			       TCPOLEN_SACK_PERM);
+	}
+
+	if (unlikely(opts->ws)) {
+		*ptr++ = htonl((TCPOPT_NOP << 24) |
+			       (TCPOPT_WINDOW << 16) |
+			       (TCPOLEN_WINDOW << 8) |
+			       opts->ws);
+	}
+
+	if (unlikely(opts->num_sack_blocks)) {
+		struct tcp_sack_block *sp = tp->rx_opt.dsack ?
+			tp->duplicate_sack : tp->selective_acks;
+		int this_sack;
+
+		*ptr++ = htonl((TCPOPT_NOP  << 24) |
+			       (TCPOPT_NOP  << 16) |
+			       (TCPOPT_SACK <<  8) |
+			       (TCPOLEN_SACK_BASE + (opts->num_sack_blocks *
+						     TCPOLEN_SACK_PERBLOCK)));
+
+		for (this_sack = 0; this_sack < opts->num_sack_blocks;
+		     ++this_sack) {
+			*ptr++ = htonl(sp[this_sack].start_seq);
+			*ptr++ = htonl(sp[this_sack].end_seq);
+		}
+
+		if (tp->rx_opt.dsack) {
+			tp->rx_opt.dsack = 0;
+			tp->rx_opt.eff_sacks = tp->rx_opt.num_sacks;
+		}
+	}
+}
+
+static unsigned tcp_syn_options(struct sock *sk, struct sk_buff *skb,
+				struct tcp_out_options *opts,
+				struct tcp_md5sig_key **md5) {
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned size = 0;
+
+#ifdef CONFIG_TCP_MD5SIG
+	*md5 = tp->af_specific->md5_lookup(sk, sk);
+	if (*md5) {
+		opts->options |= OPTION_MD5;
+		size += TCPOLEN_MD5SIG_ALIGNED;
+	}
+#else
+	*md5 = NULL;
+#endif
+
+	/* We always get an MSS option.  The option bytes which will be seen in
+	 * normal data packets should timestamps be used, must be in the MSS
+	 * advertised.  But we subtract them from tp->mss_cache so that
+	 * calculations in tcp_sendmsg are simpler etc.  So account for this
+	 * fact here if necessary.  If we don't do this correctly, as a
+	 * receiver we won't recognize data packets as being full sized when we
+	 * should, and thus we won't abide by the delayed ACK rules correctly.
+	 * SACKs don't matter, we never delay an ACK when we have any of those
+	 * going out.  */
+	opts->mss = tcp_advertise_mss(sk);
+	size += TCPOLEN_MSS_ALIGNED;
+
+	if (likely(sysctl_tcp_timestamps && *md5 == NULL)) {
+		opts->options |= OPTION_TS;
+		opts->tsval = TCP_SKB_CB(skb)->when;
+		opts->tsecr = tp->rx_opt.ts_recent;
+		size += TCPOLEN_TSTAMP_ALIGNED;
+	}
+	if (likely(sysctl_tcp_window_scaling)) {
+		opts->ws = tp->rx_opt.rcv_wscale;
+		if(likely(opts->ws))
+			size += TCPOLEN_WSCALE_ALIGNED;
+	}
+	if (likely(sysctl_tcp_sack)) {
+		opts->options |= OPTION_SACK_ADVERTISE;
+		if (unlikely(!(OPTION_TS & opts->options)))
+			size += TCPOLEN_SACKPERM_ALIGNED;
+	}
+
+	return size;
+}
+
+static unsigned tcp_synack_options(struct sock *sk,
+				   struct request_sock *req,
+				   unsigned mss, struct sk_buff *skb,
+				   struct tcp_out_options *opts,
+				   struct tcp_md5sig_key **md5) {
+	unsigned size = 0;
+	struct inet_request_sock *ireq = inet_rsk(req);
+	char doing_ts;
+
+#ifdef CONFIG_TCP_MD5SIG
+	*md5 = tcp_rsk(req)->af_specific->md5_lookup(sk, req);
+	if (*md5) {
+		opts->options |= OPTION_MD5;
+		size += TCPOLEN_MD5SIG_ALIGNED;
+	}
+#else
+	*md5 = NULL;
+#endif
+
+	/* we can't fit any SACK blocks in a packet with MD5 + TS
+	   options. There was discussion about disabling SACK rather than TS in
+	   order to fit in better with old, buggy kernels, but that was deemed
+	   to be unnecessary. */
+	doing_ts = ireq->tstamp_ok && !(*md5 && ireq->sack_ok);
+
+	opts->mss = mss;
+	size += TCPOLEN_MSS_ALIGNED;
+
+	if (likely(ireq->wscale_ok)) {
+		opts->ws = ireq->rcv_wscale;
+		if(likely(opts->ws))
+			size += TCPOLEN_WSCALE_ALIGNED;
+	}
+	if (likely(doing_ts)) {
+		opts->options |= OPTION_TS;
+		opts->tsval = TCP_SKB_CB(skb)->when;
+		opts->tsecr = req->ts_recent;
+		size += TCPOLEN_TSTAMP_ALIGNED;
+	}
+	if (likely(ireq->sack_ok)) {
+		opts->options |= OPTION_SACK_ADVERTISE;
+		if (unlikely(!doing_ts))
+			size += TCPOLEN_SACKPERM_ALIGNED;
+	}
+
+	return size;
+}
+
+static unsigned tcp_established_options(struct sock *sk, struct sk_buff *skb,
+					struct tcp_out_options *opts,
+					struct tcp_md5sig_key **md5) {
+	struct tcp_skb_cb *tcb = skb ? TCP_SKB_CB(skb) : NULL;
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned size = 0;
+
+#ifdef CONFIG_TCP_MD5SIG
+	*md5 = tp->af_specific->md5_lookup(sk, sk);
+	if (unlikely(*md5)) {
+		opts->options |= OPTION_MD5;
+		size += TCPOLEN_MD5SIG_ALIGNED;
+	}
+#else
+	*md5 = NULL;
+#endif
+
+	if (likely(tp->rx_opt.tstamp_ok)) {
+		opts->options |= OPTION_TS;
+		opts->tsval = tcb ? tcb->when : 0;
+		opts->tsecr = tp->rx_opt.ts_recent;
+		size += TCPOLEN_TSTAMP_ALIGNED;
+	}
+
+	if (unlikely(tp->rx_opt.eff_sacks)) {
+		const unsigned remaining = MAX_TCP_OPTION_SPACE - size;
+		opts->num_sack_blocks =
+			min_t(unsigned, tp->rx_opt.eff_sacks,
+			      (remaining - TCPOLEN_SACK_BASE_ALIGNED) /
+			      TCPOLEN_SACK_PERBLOCK);
+		size += TCPOLEN_SACK_BASE_ALIGNED +
+			opts->num_sack_blocks * TCPOLEN_SACK_PERBLOCK;
+	}
+
+	return size;
+}
+
+/* This routine actually transmits TCP packets queued in by
+ * tcp_do_sendmsg().  This is used by both the initial
+ * transmission and possible later retransmissions.
+ * All SKB's seen here are completely headerless.  It is our
+ * job to build the TCP header, and pass the packet down to
+ * IP so it can do the same plus pass the packet off to the
+ * device.
+ *
+ * We are working here with either a clone of the original
+ * SKB, or a fresh unique copy made by the retransmit engine.
+ */
+static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
+			    gfp_t gfp_mask)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct inet_sock *inet;
+	struct tcp_sock *tp;
+	struct tcp_skb_cb *tcb;
+	struct tcp_out_options opts;
+	unsigned tcp_options_size, tcp_header_size;
+	struct tcp_md5sig_key *md5;
+	__u8 *md5_hash_location;
+	struct tcphdr *th;
+	int err;
+
+	BUG_ON(!skb || !tcp_skb_pcount(skb));
+
+	/* If congestion control is doing timestamping, we must
+	 * take such a timestamp before we potentially clone/copy.
+	 */
+	if (icsk->icsk_ca_ops->flags & TCP_CONG_RTT_STAMP)
+		__net_timestamp(skb);
+
+	if (likely(clone_it)) {
+		if (unlikely(skb_cloned(skb)))
+			skb = pskb_copy(skb, gfp_mask);
+		else
+			skb = skb_clone(skb, gfp_mask);
+		if (unlikely(!skb))
+			return -ENOBUFS;
+	}
+
+	inet = inet_sk(sk);
+	tp = tcp_sk(sk);
+	tcb = TCP_SKB_CB(skb);
+	memset(&opts, 0, sizeof(opts));
+
+	if (unlikely(tcb->flags & TCPCB_FLAG_SYN))
+		tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
+	else
+		tcp_options_size = tcp_established_options(sk, skb, &opts,
+							   &md5);
+	tcp_header_size = tcp_options_size + sizeof(struct tcphdr);
+
+	if (tcp_packets_in_flight(tp) == 0)
+		tcp_ca_event(sk, CA_EVENT_TX_START);
+
+	skb_push(skb, tcp_header_size);
+	skb_reset_transport_header(skb);
+	skb_set_owner_w(skb, sk);
+
+	/* Build TCP header and checksum it. */
+	th = tcp_hdr(skb);
+	th->source		= inet->sport;
+	th->dest		= inet->dport;
+	th->seq			= htonl(tcb->seq);
+	th->ack_seq		= htonl(tp->rcv_nxt);
+	*(((__be16 *)th) + 6)	= htons(((tcp_header_size >> 2) << 12) |
+					tcb->flags);
+
+	if (unlikely(tcb->flags & TCPCB_FLAG_SYN)) {
+		/* RFC1323: The window in SYN & SYN/ACK segments
+		 * is never scaled.
+		 */
+		th->window	= htons(min(tp->rcv_wnd, 65535U));
+	} else {
+		th->window	= htons(tcp_select_window(sk));
+	}
+	th->check		= 0;
+	th->urg_ptr		= 0;
+
+	/* The urg_mode check is necessary during a below snd_una win probe */
+	if (unlikely(tcp_urg_mode(tp) &&
+		     between(tp->snd_up, tcb->seq + 1, tcb->seq + 0xFFFF))) {
+		th->urg_ptr		= htons(tp->snd_up - tcb->seq);
+		th->urg			= 1;
+	}
+
+	tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
+	if (likely((tcb->flags & TCPCB_FLAG_SYN) == 0))
+		TCP_ECN_send(sk, skb, tcp_header_size);
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Calculate the MD5 hash, as we have all we need now */
+	if (md5) {
+		sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+		tp->af_specific->calc_md5_hash(md5_hash_location,
+					       md5, sk, NULL, skb);
+	}
+#endif
+
+	icsk->icsk_af_ops->send_check(sk, skb->len, skb);
+
+	if (likely(tcb->flags & TCPCB_FLAG_ACK))
+		tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
+
+	if (skb->len != tcp_header_size)
+		tcp_event_data_sent(tp, skb, sk);
+
+	if (after(tcb->end_seq, tp->snd_nxt) || tcb->seq == tcb->end_seq)
+		TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
+
+	err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+	if (likely(err <= 0))
+		return err;
+
+	tcp_enter_cwr(sk, 1);
+
+	return net_xmit_eval(err);
+}
+
+/* This routine just queue's the buffer
+ *
+ * NOTE: probe0 timer is not checked, do not forget tcp_push_pending_frames,
+ * otherwise socket can stall.
+ */
+static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* Advance write_seq and place onto the write_queue. */
+	tp->write_seq = TCP_SKB_CB(skb)->end_seq;
+	skb_header_release(skb);
+	tcp_add_write_queue_tail(sk, skb);
+	sk->sk_wmem_queued += skb->truesize;
+	sk_mem_charge(sk, skb->truesize);
+}
+
+static void tcp_set_skb_tso_segs(struct sock *sk, struct sk_buff *skb,
+				 unsigned int mss_now)
+{
+	if (skb->len <= mss_now || !sk_can_gso(sk)) {
+		/* Avoid the costly divide in the normal
+		 * non-TSO case.
+		 */
+		skb_shinfo(skb)->gso_segs = 1;
+		skb_shinfo(skb)->gso_size = 0;
+		skb_shinfo(skb)->gso_type = 0;
+	} else {
+		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss_now);
+		skb_shinfo(skb)->gso_size = mss_now;
+		skb_shinfo(skb)->gso_type = sk->sk_gso_type;
+	}
+}
+
+/* When a modification to fackets out becomes necessary, we need to check
+ * skb is counted to fackets_out or not.
+ */
+static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb,
+				   int decr)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!tp->sacked_out || tcp_is_reno(tp))
+		return;
+
+	if (after(tcp_highest_sack_seq(tp), TCP_SKB_CB(skb)->seq))
+		tp->fackets_out -= decr;
+}
+
+/* Function to create two new TCP segments.  Shrinks the given segment
+ * to the specified size and appends a new segment with the rest of the
+ * packet to the list.  This won't be called frequently, I hope.
+ * Remember, these are still headerless SKBs at this point.
+ */
+int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
+		 unsigned int mss_now)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *buff;
+	int nsize, old_factor;
+	int nlen;
+	u16 flags;
+
+	BUG_ON(len > skb->len);
+
+	tcp_clear_retrans_hints_partial(tp);
+	nsize = skb_headlen(skb) - len;
+	if (nsize < 0)
+		nsize = 0;
+
+	if (skb_cloned(skb) &&
+	    skb_is_nonlinear(skb) &&
+	    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+		return -ENOMEM;
+
+	/* Get a new skb... force flag on. */
+	buff = sk_stream_alloc_skb(sk, nsize, GFP_ATOMIC);
+	if (buff == NULL)
+		return -ENOMEM; /* We'll just try again later. */
+
+	sk->sk_wmem_queued += buff->truesize;
+	sk_mem_charge(sk, buff->truesize);
+	nlen = skb->len - len - nsize;
+	buff->truesize += nlen;
+	skb->truesize -= nlen;
+
+	/* Correct the sequence numbers. */
+	TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len;
+	TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq;
+	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
+
+	/* PSH and FIN should only be set in the second packet. */
+	flags = TCP_SKB_CB(skb)->flags;
+	TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
+	TCP_SKB_CB(buff)->flags = flags;
+	TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
+
+	if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
+		/* Copy and checksum data tail into the new buffer. */
+		buff->csum = csum_partial_copy_nocheck(skb->data + len,
+						       skb_put(buff, nsize),
+						       nsize, 0);
+
+		skb_trim(skb, len);
+
+		skb->csum = csum_block_sub(skb->csum, buff->csum, len);
+	} else {
+		skb->ip_summed = CHECKSUM_PARTIAL;
+		skb_split(skb, buff, len);
+	}
+
+	buff->ip_summed = skb->ip_summed;
+
+	/* Looks stupid, but our code really uses when of
+	 * skbs, which it never sent before. --ANK
+	 */
+	TCP_SKB_CB(buff)->when = TCP_SKB_CB(skb)->when;
+	buff->tstamp = skb->tstamp;
+
+	old_factor = tcp_skb_pcount(skb);
+
+	/* Fix up tso_factor for both original and new SKB.  */
+	tcp_set_skb_tso_segs(sk, skb, mss_now);
+	tcp_set_skb_tso_segs(sk, buff, mss_now);
+
+	/* If this packet has been sent out already, we must
+	 * adjust the various packet counters.
+	 */
+	if (!before(tp->snd_nxt, TCP_SKB_CB(buff)->end_seq)) {
+		int diff = old_factor - tcp_skb_pcount(skb) -
+			tcp_skb_pcount(buff);
+
+		tp->packets_out -= diff;
+
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)
+			tp->sacked_out -= diff;
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)
+			tp->retrans_out -= diff;
+
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)
+			tp->lost_out -= diff;
+
+		/* Adjust Reno SACK estimate. */
+		if (tcp_is_reno(tp) && diff > 0) {
+			tcp_dec_pcount_approx_int(&tp->sacked_out, diff);
+			tcp_verify_left_out(tp);
+		}
+		tcp_adjust_fackets_out(sk, skb, diff);
+	}
+
+	/* Link BUFF into the send queue. */
+	skb_header_release(buff);
+	tcp_insert_write_queue_after(skb, buff, sk);
+
+	return 0;
+}
+
+/* This is similar to __pskb_pull_head() (it will go to core/skbuff.c
+ * eventually). The difference is that pulled data not copied, but
+ * immediately discarded.
+ */
+static void __pskb_trim_head(struct sk_buff *skb, int len)
+{
+	int i, k, eat;
+
+	eat = len;
+	k = 0;
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+		if (skb_shinfo(skb)->frags[i].size <= eat) {
+			put_page(skb_shinfo(skb)->frags[i].page);
+			eat -= skb_shinfo(skb)->frags[i].size;
+		} else {
+			skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i];
+			if (eat) {
+				skb_shinfo(skb)->frags[k].page_offset += eat;
+				skb_shinfo(skb)->frags[k].size -= eat;
+				eat = 0;
+			}
+			k++;
+		}
+	}
+	skb_shinfo(skb)->nr_frags = k;
+
+	skb_reset_tail_pointer(skb);
+	skb->data_len -= len;
+	skb->len = skb->data_len;
+}
+
+int tcp_trim_head(struct sock *sk, struct sk_buff *skb, u32 len)
+{
+	if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+		return -ENOMEM;
+
+	/* If len == headlen, we avoid __skb_pull to preserve alignment. */
+	if (unlikely(len < skb_headlen(skb)))
+		__skb_pull(skb, len);
+	else
+		__pskb_trim_head(skb, len - skb_headlen(skb));
+
+	TCP_SKB_CB(skb)->seq += len;
+	skb->ip_summed = CHECKSUM_PARTIAL;
+
+	skb->truesize	     -= len;
+	sk->sk_wmem_queued   -= len;
+	sk_mem_uncharge(sk, len);
+	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
+
+	/* Any change of skb->len requires recalculation of tso
+	 * factor and mss.
+	 */
+	if (tcp_skb_pcount(skb) > 1)
+		tcp_set_skb_tso_segs(sk, skb, tcp_current_mss(sk, 1));
+
+	return 0;
+}
+
+/* Not accounting for SACKs here. */
+int tcp_mtu_to_mss(struct sock *sk, int pmtu)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int mss_now;
+
+	/* Calculate base mss without TCP options:
+	   It is MMS_S - sizeof(tcphdr) of rfc1122
+	 */
+	mss_now = pmtu - icsk->icsk_af_ops->net_header_len - sizeof(struct tcphdr);
+
+	/* Clamp it (mss_clamp does not include tcp options) */
+	if (mss_now > tp->rx_opt.mss_clamp)
+		mss_now = tp->rx_opt.mss_clamp;
+
+	/* Now subtract optional transport overhead */
+	mss_now -= icsk->icsk_ext_hdr_len;
+
+	/* Then reserve room for full set of TCP options and 8 bytes of data */
+	if (mss_now < 48)
+		mss_now = 48;
+
+	/* Now subtract TCP options size, not including SACKs */
+	mss_now -= tp->tcp_header_len - sizeof(struct tcphdr);
+
+	return mss_now;
+}
+
+/* Inverse of above */
+int tcp_mss_to_mtu(struct sock *sk, int mss)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int mtu;
+
+	mtu = mss +
+	      tp->tcp_header_len +
+	      icsk->icsk_ext_hdr_len +
+	      icsk->icsk_af_ops->net_header_len;
+
+	return mtu;
+}
+
+void tcp_mtup_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	icsk->icsk_mtup.enabled = sysctl_tcp_mtu_probing > 1;
+	icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) +
+			       icsk->icsk_af_ops->net_header_len;
+	icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, sysctl_tcp_base_mss);
+	icsk->icsk_mtup.probe_size = 0;
+}
+
+/* Bound MSS / TSO packet size with the half of the window */
+static int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
+{
+	if (tp->max_window && pktsize > (tp->max_window >> 1))
+		return max(tp->max_window >> 1, 68U - tp->tcp_header_len);
+	else
+		return pktsize;
+}
+
+/* This function synchronize snd mss to current pmtu/exthdr set.
+
+   tp->rx_opt.user_mss is mss set by user by TCP_MAXSEG. It does NOT counts
+   for TCP options, but includes only bare TCP header.
+
+   tp->rx_opt.mss_clamp is mss negotiated at connection setup.
+   It is minimum of user_mss and mss received with SYN.
+   It also does not include TCP options.
+
+   inet_csk(sk)->icsk_pmtu_cookie is last pmtu, seen by this function.
+
+   tp->mss_cache is current effective sending mss, including
+   all tcp options except for SACKs. It is evaluated,
+   taking into account current pmtu, but never exceeds
+   tp->rx_opt.mss_clamp.
+
+   NOTE1. rfc1122 clearly states that advertised MSS
+   DOES NOT include either tcp or ip options.
+
+   NOTE2. inet_csk(sk)->icsk_pmtu_cookie and tp->mss_cache
+   are READ ONLY outside this function.		--ANK (980731)
+ */
+unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int mss_now;
+
+	if (icsk->icsk_mtup.search_high > pmtu)
+		icsk->icsk_mtup.search_high = pmtu;
+
+	mss_now = tcp_mtu_to_mss(sk, pmtu);
+	mss_now = tcp_bound_to_half_wnd(tp, mss_now);
+
+	/* And store cached results */
+	icsk->icsk_pmtu_cookie = pmtu;
+	if (icsk->icsk_mtup.enabled)
+		mss_now = min(mss_now, tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low));
+	tp->mss_cache = mss_now;
+
+	return mss_now;
+}
+
+/* Compute the current effective MSS, taking SACKs and IP options,
+ * and even PMTU discovery events into account.
+ */
+unsigned int tcp_current_mss(struct sock *sk, int large_allowed)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct dst_entry *dst = __sk_dst_get(sk);
+	u32 mss_now;
+	u16 xmit_size_goal;
+	int doing_tso = 0;
+	unsigned header_len;
+	struct tcp_out_options opts;
+	struct tcp_md5sig_key *md5;
+
+	mss_now = tp->mss_cache;
+
+	if (large_allowed && sk_can_gso(sk))
+		doing_tso = 1;
+
+	if (dst) {
+		u32 mtu = dst_mtu(dst);
+		if (mtu != inet_csk(sk)->icsk_pmtu_cookie)
+			mss_now = tcp_sync_mss(sk, mtu);
+	}
+
+	header_len = tcp_established_options(sk, NULL, &opts, &md5) +
+		     sizeof(struct tcphdr);
+	/* The mss_cache is sized based on tp->tcp_header_len, which assumes
+	 * some common options. If this is an odd packet (because we have SACK
+	 * blocks etc) then our calculated header_len will be different, and
+	 * we have to adjust mss_now correspondingly */
+	if (header_len != tp->tcp_header_len) {
+		int delta = (int) header_len - tp->tcp_header_len;
+		mss_now -= delta;
+	}
+
+	xmit_size_goal = mss_now;
+
+	if (doing_tso) {
+		xmit_size_goal = ((sk->sk_gso_max_size - 1) -
+				  inet_csk(sk)->icsk_af_ops->net_header_len -
+				  inet_csk(sk)->icsk_ext_hdr_len -
+				  tp->tcp_header_len);
+
+		xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
+		xmit_size_goal -= (xmit_size_goal % mss_now);
+	}
+	tp->xmit_size_goal = xmit_size_goal;
+
+	return mss_now;
+}
+
+/* Congestion window validation. (RFC2861) */
+static void tcp_cwnd_validate(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (tp->packets_out >= tp->snd_cwnd) {
+		/* Network is feed fully. */
+		tp->snd_cwnd_used = 0;
+		tp->snd_cwnd_stamp = tcp_time_stamp;
+	} else {
+		/* Network starves. */
+		if (tp->packets_out > tp->snd_cwnd_used)
+			tp->snd_cwnd_used = tp->packets_out;
+
+		if (sysctl_tcp_slow_start_after_idle &&
+		    (s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= inet_csk(sk)->icsk_rto)
+			tcp_cwnd_application_limited(sk);
+	}
+}
+
+/* Returns the portion of skb which can be sent right away without
+ * introducing MSS oddities to segment boundaries. In rare cases where
+ * mss_now != mss_cache, we will request caller to create a small skb
+ * per input skb which could be mostly avoided here (if desired).
+ *
+ * We explicitly want to create a request for splitting write queue tail
+ * to a small skb for Nagle purposes while avoiding unnecessary modulos,
+ * thus all the complexity (cwnd_len is always MSS multiple which we
+ * return whenever allowed by the other factors). Basically we need the
+ * modulo only when the receiver window alone is the limiting factor or
+ * when we would be allowed to send the split-due-to-Nagle skb fully.
+ */
+static unsigned int tcp_mss_split_point(struct sock *sk, struct sk_buff *skb,
+					unsigned int mss_now, unsigned int cwnd)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 needed, window, cwnd_len;
+
+	window = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
+	cwnd_len = mss_now * cwnd;
+
+	if (likely(cwnd_len <= window && skb != tcp_write_queue_tail(sk)))
+		return cwnd_len;
+
+	needed = min(skb->len, window);
+
+	if (cwnd_len <= needed)
+		return cwnd_len;
+
+	return needed - needed % mss_now;
+}
+
+/* Can at least one segment of SKB be sent right now, according to the
+ * congestion window rules?  If so, return how many segments are allowed.
+ */
+static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
+					 struct sk_buff *skb)
+{
+	u32 in_flight, cwnd;
+
+	/* Don't be strict about the congestion window for the final FIN.  */
+	if ((TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+	    tcp_skb_pcount(skb) == 1)
+		return 1;
+
+	in_flight = tcp_packets_in_flight(tp);
+	cwnd = tp->snd_cwnd;
+	if (in_flight < cwnd)
+		return (cwnd - in_flight);
+
+	return 0;
+}
+
+/* This must be invoked the first time we consider transmitting
+ * SKB onto the wire.
+ */
+static int tcp_init_tso_segs(struct sock *sk, struct sk_buff *skb,
+			     unsigned int mss_now)
+{
+	int tso_segs = tcp_skb_pcount(skb);
+
+	if (!tso_segs || (tso_segs > 1 && tcp_skb_mss(skb) != mss_now)) {
+		tcp_set_skb_tso_segs(sk, skb, mss_now);
+		tso_segs = tcp_skb_pcount(skb);
+	}
+	return tso_segs;
+}
+
+static inline int tcp_minshall_check(const struct tcp_sock *tp)
+{
+	return after(tp->snd_sml,tp->snd_una) &&
+		!after(tp->snd_sml, tp->snd_nxt);
+}
+
+/* Return 0, if packet can be sent now without violation Nagle's rules:
+ * 1. It is full sized.
+ * 2. Or it contains FIN. (already checked by caller)
+ * 3. Or TCP_NODELAY was set.
+ * 4. Or TCP_CORK is not set, and all sent packets are ACKed.
+ *    With Minshall's modification: all sent small packets are ACKed.
+ */
+static inline int tcp_nagle_check(const struct tcp_sock *tp,
+				  const struct sk_buff *skb,
+				  unsigned mss_now, int nonagle)
+{
+	return (skb->len < mss_now &&
+		((nonagle & TCP_NAGLE_CORK) ||
+		 (!nonagle && tp->packets_out && tcp_minshall_check(tp))));
+}
+
+/* Return non-zero if the Nagle test allows this packet to be
+ * sent now.
+ */
+static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb,
+				 unsigned int cur_mss, int nonagle)
+{
+	/* Nagle rule does not apply to frames, which sit in the middle of the
+	 * write_queue (they have no chances to get new data).
+	 *
+	 * This is implemented in the callers, where they modify the 'nonagle'
+	 * argument based upon the location of SKB in the send queue.
+	 */
+	if (nonagle & TCP_NAGLE_PUSH)
+		return 1;
+
+	/* Don't use the nagle rule for urgent data (or for the final FIN).
+	 * Nagle can be ignored during F-RTO too (see RFC4138).
+	 */
+	if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
+	    (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN))
+		return 1;
+
+	if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
+		return 1;
+
+	return 0;
+}
+
+/* Does at least the first segment of SKB fit into the send window? */
+static inline int tcp_snd_wnd_test(struct tcp_sock *tp, struct sk_buff *skb,
+				   unsigned int cur_mss)
+{
+	u32 end_seq = TCP_SKB_CB(skb)->end_seq;
+
+	if (skb->len > cur_mss)
+		end_seq = TCP_SKB_CB(skb)->seq + cur_mss;
+
+	return !after(end_seq, tcp_wnd_end(tp));
+}
+
+/* This checks if the data bearing packet SKB (usually tcp_send_head(sk))
+ * should be put on the wire right now.  If so, it returns the number of
+ * packets allowed by the congestion window.
+ */
+static unsigned int tcp_snd_test(struct sock *sk, struct sk_buff *skb,
+				 unsigned int cur_mss, int nonagle)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	unsigned int cwnd_quota;
+
+	tcp_init_tso_segs(sk, skb, cur_mss);
+
+	if (!tcp_nagle_test(tp, skb, cur_mss, nonagle))
+		return 0;
+
+	cwnd_quota = tcp_cwnd_test(tp, skb);
+	if (cwnd_quota && !tcp_snd_wnd_test(tp, skb, cur_mss))
+		cwnd_quota = 0;
+
+	return cwnd_quota;
+}
+
+int tcp_may_send_now(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb = tcp_send_head(sk);
+
+	return (skb &&
+		tcp_snd_test(sk, skb, tcp_current_mss(sk, 1),
+			     (tcp_skb_is_last(sk, skb) ?
+			      tp->nonagle : TCP_NAGLE_PUSH)));
+}
+
+/* Trim TSO SKB to LEN bytes, put the remaining data into a new packet
+ * which is put after SKB on the list.  It is very much like
+ * tcp_fragment() except that it may make several kinds of assumptions
+ * in order to speed up the splitting operation.  In particular, we
+ * know that all the data is in scatter-gather pages, and that the
+ * packet has never been sent out before (and thus is not cloned).
+ */
+static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
+			unsigned int mss_now)
+{
+	struct sk_buff *buff;
+	int nlen = skb->len - len;
+	u16 flags;
+
+	/* All of a TSO frame must be composed of paged data.  */
+	if (skb->len != skb->data_len)
+		return tcp_fragment(sk, skb, len, mss_now);
+
+	buff = sk_stream_alloc_skb(sk, 0, GFP_ATOMIC);
+	if (unlikely(buff == NULL))
+		return -ENOMEM;
+
+	sk->sk_wmem_queued += buff->truesize;
+	sk_mem_charge(sk, buff->truesize);
+	buff->truesize += nlen;
+	skb->truesize -= nlen;
+
+	/* Correct the sequence numbers. */
+	TCP_SKB_CB(buff)->seq = TCP_SKB_CB(skb)->seq + len;
+	TCP_SKB_CB(buff)->end_seq = TCP_SKB_CB(skb)->end_seq;
+	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
+
+	/* PSH and FIN should only be set in the second packet. */
+	flags = TCP_SKB_CB(skb)->flags;
+	TCP_SKB_CB(skb)->flags = flags & ~(TCPCB_FLAG_FIN | TCPCB_FLAG_PSH);
+	TCP_SKB_CB(buff)->flags = flags;
+
+	/* This packet was never sent out yet, so no SACK bits. */
+	TCP_SKB_CB(buff)->sacked = 0;
+
+	buff->ip_summed = skb->ip_summed = CHECKSUM_PARTIAL;
+	skb_split(skb, buff, len);
+
+	/* Fix up tso_factor for both original and new SKB.  */
+	tcp_set_skb_tso_segs(sk, skb, mss_now);
+	tcp_set_skb_tso_segs(sk, buff, mss_now);
+
+	/* Link BUFF into the send queue. */
+	skb_header_release(buff);
+	tcp_insert_write_queue_after(skb, buff, sk);
+
+	return 0;
+}
+
+/* Try to defer sending, if possible, in order to minimize the amount
+ * of TSO splitting we do.  View it as a kind of TSO Nagle test.
+ *
+ * This algorithm is from John Heffner.
+ */
+static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	u32 send_win, cong_win, limit, in_flight;
+
+	if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
+		goto send_now;
+
+	if (icsk->icsk_ca_state != TCP_CA_Open)
+		goto send_now;
+
+	/* Defer for less than two clock ticks. */
+	if (tp->tso_deferred &&
+	    ((jiffies << 1) >> 1) - (tp->tso_deferred >> 1) > 1)
+		goto send_now;
+
+	in_flight = tcp_packets_in_flight(tp);
+
+	BUG_ON(tcp_skb_pcount(skb) <= 1 || (tp->snd_cwnd <= in_flight));
+
+	send_win = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
+
+	/* From in_flight test above, we know that cwnd > in_flight.  */
+	cong_win = (tp->snd_cwnd - in_flight) * tp->mss_cache;
+
+	limit = min(send_win, cong_win);
+
+	/* If a full-sized TSO skb can be sent, do it. */
+	if (limit >= sk->sk_gso_max_size)
+		goto send_now;
+
+	if (sysctl_tcp_tso_win_divisor) {
+		u32 chunk = min(tp->snd_wnd, tp->snd_cwnd * tp->mss_cache);
+
+		/* If at least some fraction of a window is available,
+		 * just use it.
+		 */
+		chunk /= sysctl_tcp_tso_win_divisor;
+		if (limit >= chunk)
+			goto send_now;
+	} else {
+		/* Different approach, try not to defer past a single
+		 * ACK.  Receiver should ACK every other full sized
+		 * frame, so if we have space for more than 3 frames
+		 * then send now.
+		 */
+		if (limit > tcp_max_burst(tp) * tp->mss_cache)
+			goto send_now;
+	}
+
+	/* Ok, it looks like it is advisable to defer.  */
+	tp->tso_deferred = 1 | (jiffies << 1);
+
+	return 1;
+
+send_now:
+	tp->tso_deferred = 0;
+	return 0;
+}
+
+/* Create a new MTU probe if we are ready.
+ * Returns 0 if we should wait to probe (no cwnd available),
+ *         1 if a probe was sent,
+ *         -1 otherwise
+ */
+static int tcp_mtu_probe(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct sk_buff *skb, *nskb, *next;
+	int len;
+	int probe_size;
+	int size_needed;
+	int copy;
+	int mss_now;
+
+	/* Not currently probing/verifying,
+	 * not in recovery,
+	 * have enough cwnd, and
+	 * not SACKing (the variable headers throw things off) */
+	if (!icsk->icsk_mtup.enabled ||
+	    icsk->icsk_mtup.probe_size ||
+	    inet_csk(sk)->icsk_ca_state != TCP_CA_Open ||
+	    tp->snd_cwnd < 11 ||
+	    tp->rx_opt.eff_sacks)
+		return -1;
+
+	/* Very simple search strategy: just double the MSS. */
+	mss_now = tcp_current_mss(sk, 0);
+	probe_size = 2 * tp->mss_cache;
+	size_needed = probe_size + (tp->reordering + 1) * tp->mss_cache;
+	if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high)) {
+		/* TODO: set timer for probe_converge_event */
+		return -1;
+	}
+
+	/* Have enough data in the send queue to probe? */
+	if (tp->write_seq - tp->snd_nxt < size_needed)
+		return -1;
+
+	if (tp->snd_wnd < size_needed)
+		return -1;
+	if (after(tp->snd_nxt + size_needed, tcp_wnd_end(tp)))
+		return 0;
+
+	/* Do we need to wait to drain cwnd? With none in flight, don't stall */
+	if (tcp_packets_in_flight(tp) + 2 > tp->snd_cwnd) {
+		if (!tcp_packets_in_flight(tp))
+			return -1;
+		else
+			return 0;
+	}
+
+	/* We're allowed to probe.  Build it now. */
+	if ((nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC)) == NULL)
+		return -1;
+	sk->sk_wmem_queued += nskb->truesize;
+	sk_mem_charge(sk, nskb->truesize);
+
+	skb = tcp_send_head(sk);
+
+	TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
+	TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
+	TCP_SKB_CB(nskb)->flags = TCPCB_FLAG_ACK;
+	TCP_SKB_CB(nskb)->sacked = 0;
+	nskb->csum = 0;
+	nskb->ip_summed = skb->ip_summed;
+
+	tcp_insert_write_queue_before(nskb, skb, sk);
+
+	len = 0;
+	tcp_for_write_queue_from_safe(skb, next, sk) {
+		copy = min_t(int, skb->len, probe_size - len);
+		if (nskb->ip_summed)
+			skb_copy_bits(skb, 0, skb_put(nskb, copy), copy);
+		else
+			nskb->csum = skb_copy_and_csum_bits(skb, 0,
+							    skb_put(nskb, copy),
+							    copy, nskb->csum);
+
+		if (skb->len <= copy) {
+			/* We've eaten all the data from this skb.
+			 * Throw it away. */
+			TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags;
+			tcp_unlink_write_queue(skb, sk);
+			sk_wmem_free_skb(sk, skb);
+		} else {
+			TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags &
+						   ~(TCPCB_FLAG_FIN|TCPCB_FLAG_PSH);
+			if (!skb_shinfo(skb)->nr_frags) {
+				skb_pull(skb, copy);
+				if (skb->ip_summed != CHECKSUM_PARTIAL)
+					skb->csum = csum_partial(skb->data,
+								 skb->len, 0);
+			} else {
+				__pskb_trim_head(skb, copy);
+				tcp_set_skb_tso_segs(sk, skb, mss_now);
+			}
+			TCP_SKB_CB(skb)->seq += copy;
+		}
+
+		len += copy;
+
+		if (len >= probe_size)
+			break;
+	}
+	tcp_init_tso_segs(sk, nskb, nskb->len);
+
+	/* We're ready to send.  If this fails, the probe will
+	 * be resegmented into mss-sized pieces by tcp_write_xmit(). */
+	TCP_SKB_CB(nskb)->when = tcp_time_stamp;
+	if (!tcp_transmit_skb(sk, nskb, 1, GFP_ATOMIC)) {
+		/* Decrement cwnd here because we are sending
+		 * effectively two packets. */
+		tp->snd_cwnd--;
+		tcp_event_new_data_sent(sk, nskb);
+
+		icsk->icsk_mtup.probe_size = tcp_mss_to_mtu(sk, nskb->len);
+		tp->mtu_probe.probe_seq_start = TCP_SKB_CB(nskb)->seq;
+		tp->mtu_probe.probe_seq_end = TCP_SKB_CB(nskb)->end_seq;
+
+		return 1;
+	}
+
+	return -1;
+}
+
+/* This routine writes packets to the network.  It advances the
+ * send_head.  This happens as incoming acks open up the remote
+ * window for us.
+ *
+ * LARGESEND note: !tcp_urg_mode is overkill, only frames between
+ * snd_up-64k-mss .. snd_up cannot be large. However, taking into
+ * account rare use of URG, this is not a big flaw.
+ *
+ * Returns 1, if no segments are in flight and we have queued segments, but
+ * cannot send anything now because of SWS or another problem.
+ */
+static int tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	unsigned int tso_segs, sent_pkts;
+	int cwnd_quota;
+	int result;
+
+	/* If we are closed, the bytes will have to remain here.
+	 * In time closedown will finish, we empty the write queue and all
+	 * will be happy.
+	 */
+	if (unlikely(sk->sk_state == TCP_CLOSE))
+		return 0;
+
+	sent_pkts = 0;
+
+	/* Do MTU probing. */
+	if ((result = tcp_mtu_probe(sk)) == 0) {
+		return 0;
+	} else if (result > 0) {
+		sent_pkts = 1;
+	}
+
+	while ((skb = tcp_send_head(sk))) {
+		unsigned int limit;
+
+		tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
+		BUG_ON(!tso_segs);
+
+		cwnd_quota = tcp_cwnd_test(tp, skb);
+		if (!cwnd_quota)
+			break;
+
+		if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now)))
+			break;
+
+		if (tso_segs == 1) {
+			if (unlikely(!tcp_nagle_test(tp, skb, mss_now,
+						     (tcp_skb_is_last(sk, skb) ?
+						      nonagle : TCP_NAGLE_PUSH))))
+				break;
+		} else {
+			if (tcp_tso_should_defer(sk, skb))
+				break;
+		}
+
+		limit = mss_now;
+		if (tso_segs > 1 && !tcp_urg_mode(tp))
+			limit = tcp_mss_split_point(sk, skb, mss_now,
+						    cwnd_quota);
+
+		if (skb->len > limit &&
+		    unlikely(tso_fragment(sk, skb, limit, mss_now)))
+			break;
+
+		TCP_SKB_CB(skb)->when = tcp_time_stamp;
+
+		if (unlikely(tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC)))
+			break;
+
+		/* Advance the send_head.  This one is sent out.
+		 * This call will increment packets_out.
+		 */
+		tcp_event_new_data_sent(sk, skb);
+
+		tcp_minshall_update(tp, mss_now, skb);
+		sent_pkts++;
+	}
+
+	if (likely(sent_pkts)) {
+		tcp_cwnd_validate(sk);
+		return 0;
+	}
+	return !tp->packets_out && tcp_send_head(sk);
+}
+
+/* Push out any pending frames which were held back due to
+ * TCP_CORK or attempt at coalescing tiny packets.
+ * The socket must be locked by the caller.
+ */
+void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
+			       int nonagle)
+{
+	struct sk_buff *skb = tcp_send_head(sk);
+
+	if (skb) {
+		if (tcp_write_xmit(sk, cur_mss, nonagle))
+			tcp_check_probe_timer(sk);
+	}
+}
+
+/* Send _single_ skb sitting at the send head. This function requires
+ * true push pending frames to setup probe timer etc.
+ */
+void tcp_push_one(struct sock *sk, unsigned int mss_now)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb = tcp_send_head(sk);
+	unsigned int tso_segs, cwnd_quota;
+
+	BUG_ON(!skb || skb->len < mss_now);
+
+	tso_segs = tcp_init_tso_segs(sk, skb, mss_now);
+	cwnd_quota = tcp_snd_test(sk, skb, mss_now, TCP_NAGLE_PUSH);
+
+	if (likely(cwnd_quota)) {
+		unsigned int limit;
+
+		BUG_ON(!tso_segs);
+
+		limit = mss_now;
+		if (tso_segs > 1 && !tcp_urg_mode(tp))
+			limit = tcp_mss_split_point(sk, skb, mss_now,
+						    cwnd_quota);
+
+		if (skb->len > limit &&
+		    unlikely(tso_fragment(sk, skb, limit, mss_now)))
+			return;
+
+		/* Send it out now. */
+		TCP_SKB_CB(skb)->when = tcp_time_stamp;
+
+		if (likely(!tcp_transmit_skb(sk, skb, 1, sk->sk_allocation))) {
+			tcp_event_new_data_sent(sk, skb);
+			tcp_cwnd_validate(sk);
+			return;
+		}
+	}
+}
+
+/* This function returns the amount that we can raise the
+ * usable window based on the following constraints
+ *
+ * 1. The window can never be shrunk once it is offered (RFC 793)
+ * 2. We limit memory per socket
+ *
+ * RFC 1122:
+ * "the suggested [SWS] avoidance algorithm for the receiver is to keep
+ *  RECV.NEXT + RCV.WIN fixed until:
+ *  RCV.BUFF - RCV.USER - RCV.WINDOW >= min(1/2 RCV.BUFF, MSS)"
+ *
+ * i.e. don't raise the right edge of the window until you can raise
+ * it at least MSS bytes.
+ *
+ * Unfortunately, the recommended algorithm breaks header prediction,
+ * since header prediction assumes th->window stays fixed.
+ *
+ * Strictly speaking, keeping th->window fixed violates the receiver
+ * side SWS prevention criteria. The problem is that under this rule
+ * a stream of single byte packets will cause the right side of the
+ * window to always advance by a single byte.
+ *
+ * Of course, if the sender implements sender side SWS prevention
+ * then this will not be a problem.
+ *
+ * BSD seems to make the following compromise:
+ *
+ *	If the free space is less than the 1/4 of the maximum
+ *	space available and the free space is less than 1/2 mss,
+ *	then set the window to 0.
+ *	[ Actually, bsd uses MSS and 1/4 of maximal _window_ ]
+ *	Otherwise, just prevent the window from shrinking
+ *	and from being larger than the largest representable value.
+ *
+ * This prevents incremental opening of the window in the regime
+ * where TCP is limited by the speed of the reader side taking
+ * data out of the TCP receive queue. It does nothing about
+ * those cases where the window is constrained on the sender side
+ * because the pipeline is full.
+ *
+ * BSD also seems to "accidentally" limit itself to windows that are a
+ * multiple of MSS, at least until the free space gets quite small.
+ * This would appear to be a side effect of the mbuf implementation.
+ * Combining these two algorithms results in the observed behavior
+ * of having a fixed window size at almost all times.
+ *
+ * Below we obtain similar behavior by forcing the offered window to
+ * a multiple of the mss when it is feasible to do so.
+ *
+ * Note, we don't "adjust" for TIMESTAMP or SACK option bytes.
+ * Regular options like TIMESTAMP are taken into account.
+ */
+u32 __tcp_select_window(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	/* MSS for the peer's data.  Previous versions used mss_clamp
+	 * here.  I don't know if the value based on our guesses
+	 * of peer's MSS is better for the performance.  It's more correct
+	 * but may be worse for the performance because of rcv_mss
+	 * fluctuations.  --SAW  1998/11/1
+	 */
+	int mss = icsk->icsk_ack.rcv_mss;
+	int free_space = tcp_space(sk);
+	int full_space = min_t(int, tp->window_clamp, tcp_full_space(sk));
+	int window;
+
+	if (mss > full_space)
+		mss = full_space;
+
+	if (free_space < (full_space >> 1)) {
+		icsk->icsk_ack.quick = 0;
+
+		if (tcp_memory_pressure)
+			tp->rcv_ssthresh = min(tp->rcv_ssthresh,
+					       4U * tp->advmss);
+
+		if (free_space < mss)
+			return 0;
+	}
+
+	if (free_space > tp->rcv_ssthresh)
+		free_space = tp->rcv_ssthresh;
+
+	/* Don't do rounding if we are using window scaling, since the
+	 * scaled window will not line up with the MSS boundary anyway.
+	 */
+	window = tp->rcv_wnd;
+	if (tp->rx_opt.rcv_wscale) {
+		window = free_space;
+
+		/* Advertise enough space so that it won't get scaled away.
+		 * Import case: prevent zero window announcement if
+		 * 1<<rcv_wscale > mss.
+		 */
+		if (((window >> tp->rx_opt.rcv_wscale) << tp->rx_opt.rcv_wscale) != window)
+			window = (((window >> tp->rx_opt.rcv_wscale) + 1)
+				  << tp->rx_opt.rcv_wscale);
+	} else {
+		/* Get the largest window that is a nice multiple of mss.
+		 * Window clamp already applied above.
+		 * If our current window offering is within 1 mss of the
+		 * free space we just keep it. This prevents the divide
+		 * and multiply from happening most of the time.
+		 * We also don't do any window rounding when the free space
+		 * is too small.
+		 */
+		if (window <= free_space - mss || window > free_space)
+			window = (free_space / mss) * mss;
+		else if (mss == full_space &&
+			 free_space > window + (full_space >> 1))
+			window = free_space;
+	}
+
+	return window;
+}
+
+/* Attempt to collapse two adjacent SKB's during retransmission. */
+static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *skb,
+				     int mss_now)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *next_skb = tcp_write_queue_next(sk, skb);
+	int skb_size, next_skb_size;
+	u16 flags;
+
+	/* The first test we must make is that neither of these two
+	 * SKB's are still referenced by someone else.
+	 */
+	if (skb_cloned(skb) || skb_cloned(next_skb))
+		return;
+
+	skb_size = skb->len;
+	next_skb_size = next_skb->len;
+	flags = TCP_SKB_CB(skb)->flags;
+
+	/* Also punt if next skb has been SACK'd. */
+	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_ACKED)
+		return;
+
+	/* Next skb is out of window. */
+	if (after(TCP_SKB_CB(next_skb)->end_seq, tcp_wnd_end(tp)))
+		return;
+
+	/* Punt if not enough space exists in the first SKB for
+	 * the data in the second, or the total combined payload
+	 * would exceed the MSS.
+	 */
+	if ((next_skb_size > skb_tailroom(skb)) ||
+	    ((skb_size + next_skb_size) > mss_now))
+		return;
+
+	BUG_ON(tcp_skb_pcount(skb) != 1 || tcp_skb_pcount(next_skb) != 1);
+
+	tcp_highest_sack_combine(sk, next_skb, skb);
+
+	/* Ok.	We will be able to collapse the packet. */
+	tcp_unlink_write_queue(next_skb, sk);
+
+	skb_copy_from_linear_data(next_skb, skb_put(skb, next_skb_size),
+				  next_skb_size);
+
+	if (next_skb->ip_summed == CHECKSUM_PARTIAL)
+		skb->ip_summed = CHECKSUM_PARTIAL;
+
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);
+
+	/* Update sequence range on original skb. */
+	TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
+
+	/* Merge over control information. */
+	flags |= TCP_SKB_CB(next_skb)->flags; /* This moves PSH/FIN etc. over */
+	TCP_SKB_CB(skb)->flags = flags;
+
+	/* All done, get rid of second SKB and account for it so
+	 * packet counting does not break.
+	 */
+	TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS;
+	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_RETRANS)
+		tp->retrans_out -= tcp_skb_pcount(next_skb);
+	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_LOST)
+		tp->lost_out -= tcp_skb_pcount(next_skb);
+	/* Reno case is special. Sigh... */
+	if (tcp_is_reno(tp) && tp->sacked_out)
+		tcp_dec_pcount_approx(&tp->sacked_out, next_skb);
+
+	tcp_adjust_fackets_out(sk, next_skb, tcp_skb_pcount(next_skb));
+	tp->packets_out -= tcp_skb_pcount(next_skb);
+
+	/* changed transmit queue under us so clear hints */
+	tcp_clear_retrans_hints_partial(tp);
+	if (next_skb == tp->retransmit_skb_hint)
+		tp->retransmit_skb_hint = skb;
+
+	sk_wmem_free_skb(sk, next_skb);
+}
+
+/* Do a simple retransmit without using the backoff mechanisms in
+ * tcp_timer. This is used for path mtu discovery.
+ * The socket is already locked here.
+ */
+void tcp_simple_retransmit(struct sock *sk)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	unsigned int mss = tcp_current_mss(sk, 0);
+	u32 prior_lost = tp->lost_out;
+
+	tcp_for_write_queue(skb, sk) {
+		if (skb == tcp_send_head(sk))
+			break;
+		if (skb->len > mss &&
+		    !(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) {
+			if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
+				TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS;
+				tp->retrans_out -= tcp_skb_pcount(skb);
+			}
+			tcp_skb_mark_lost_uncond_verify(tp, skb);
+		}
+	}
+
+	tcp_clear_retrans_hints_partial(tp);
+
+	if (prior_lost == tp->lost_out)
+		return;
+
+	if (tcp_is_reno(tp))
+		tcp_limit_reno_sacked(tp);
+
+	tcp_verify_left_out(tp);
+
+	/* Don't muck with the congestion window here.
+	 * Reason is that we do not increase amount of _data_
+	 * in network, but units changed and effective
+	 * cwnd/ssthresh really reduced now.
+	 */
+	if (icsk->icsk_ca_state != TCP_CA_Loss) {
+		tp->high_seq = tp->snd_nxt;
+		tp->snd_ssthresh = tcp_current_ssthresh(sk);
+		tp->prior_ssthresh = 0;
+		tp->undo_marker = 0;
+		tcp_set_ca_state(sk, TCP_CA_Loss);
+	}
+	tcp_xmit_retransmit_queue(sk);
+}
+
+/* This retransmits one SKB.  Policy decisions and retransmit queue
+ * state updates are done by the caller.  Returns non-zero if an
+ * error occurred which prevented the send.
+ */
+int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	unsigned int cur_mss;
+	int err;
+
+	/* Inconslusive MTU probe */
+	if (icsk->icsk_mtup.probe_size) {
+		icsk->icsk_mtup.probe_size = 0;
+	}
+
+	/* Do not sent more than we queued. 1/4 is reserved for possible
+	 * copying overhead: fragmentation, tunneling, mangling etc.
+	 */
+	if (atomic_read(&sk->sk_wmem_alloc) >
+	    min(sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), sk->sk_sndbuf))
+		return -EAGAIN;
+
+	if (before(TCP_SKB_CB(skb)->seq, tp->snd_una)) {
+		if (before(TCP_SKB_CB(skb)->end_seq, tp->snd_una))
+			BUG();
+		if (tcp_trim_head(sk, skb, tp->snd_una - TCP_SKB_CB(skb)->seq))
+			return -ENOMEM;
+	}
+
+	if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
+		return -EHOSTUNREACH; /* Routing failure or similar. */
+
+	cur_mss = tcp_current_mss(sk, 0);
+
+	/* If receiver has shrunk his window, and skb is out of
+	 * new window, do not retransmit it. The exception is the
+	 * case, when window is shrunk to zero. In this case
+	 * our retransmit serves as a zero window probe.
+	 */
+	if (!before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))
+	    && TCP_SKB_CB(skb)->seq != tp->snd_una)
+		return -EAGAIN;
+
+	if (skb->len > cur_mss) {
+		if (tcp_fragment(sk, skb, cur_mss, cur_mss))
+			return -ENOMEM; /* We'll try again later. */
+	}
+
+	/* Collapse two adjacent packets if worthwhile and we can. */
+	if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN) &&
+	    (skb->len < (cur_mss >> 1)) &&
+	    (!tcp_skb_is_last(sk, skb)) &&
+	    (tcp_write_queue_next(sk, skb) != tcp_send_head(sk)) &&
+	    (skb_shinfo(skb)->nr_frags == 0 &&
+	     skb_shinfo(tcp_write_queue_next(sk, skb))->nr_frags == 0) &&
+	    (tcp_skb_pcount(skb) == 1 &&
+	     tcp_skb_pcount(tcp_write_queue_next(sk, skb)) == 1) &&
+	    (sysctl_tcp_retrans_collapse != 0))
+		tcp_retrans_try_collapse(sk, skb, cur_mss);
+
+	/* Some Solaris stacks overoptimize and ignore the FIN on a
+	 * retransmit when old data is attached.  So strip it off
+	 * since it is cheap to do so and saves bytes on the network.
+	 */
+	if (skb->len > 0 &&
+	    (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
+	    tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
+		if (!pskb_trim(skb, 0)) {
+			/* Reuse, even though it does some unnecessary work */
+			tcp_init_nondata_skb(skb, TCP_SKB_CB(skb)->end_seq - 1,
+					     TCP_SKB_CB(skb)->flags);
+			skb->ip_summed = CHECKSUM_NONE;
+		}
+	}
+
+	/* Make a copy, if the first transmission SKB clone we made
+	 * is still in somebody's hands, else make a clone.
+	 */
+	TCP_SKB_CB(skb)->when = tcp_time_stamp;
+
+	err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
+
+	if (err == 0) {
+		/* Update global TCP statistics. */
+		TCP_INC_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS);
+
+		tp->total_retrans++;
+
+#if FASTRETRANS_DEBUG > 0
+		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) {
+			if (net_ratelimit())
+				printk(KERN_DEBUG "retrans_out leaked.\n");
+		}
+#endif
+		if (!tp->retrans_out)
+			tp->lost_retrans_low = tp->snd_nxt;
+		TCP_SKB_CB(skb)->sacked |= TCPCB_RETRANS;
+		tp->retrans_out += tcp_skb_pcount(skb);
+
+		/* Save stamp of the first retransmit. */
+		if (!tp->retrans_stamp)
+			tp->retrans_stamp = TCP_SKB_CB(skb)->when;
+
+		tp->undo_retrans++;
+
+		/* snd_nxt is stored to detect loss of retransmitted segment,
+		 * see tcp_input.c tcp_sacktag_write_queue().
+		 */
+		TCP_SKB_CB(skb)->ack_seq = tp->snd_nxt;
+	}
+	return err;
+}
+
+static int tcp_can_forward_retransmit(struct sock *sk)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* Forward retransmissions are possible only during Recovery. */
+	if (icsk->icsk_ca_state != TCP_CA_Recovery)
+		return 0;
+
+	/* No forward retransmissions in Reno are possible. */
+	if (tcp_is_reno(tp))
+		return 0;
+
+	/* Yeah, we have to make difficult choice between forward transmission
+	 * and retransmission... Both ways have their merits...
+	 *
+	 * For now we do not retransmit anything, while we have some new
+	 * segments to send. In the other cases, follow rule 3 for
+	 * NextSeg() specified in RFC3517.
+	 */
+
+	if (tcp_may_send_now(sk))
+		return 0;
+
+	return 1;
+}
+
+/* This gets called after a retransmit timeout, and the initially
+ * retransmitted data is acknowledged.  It tries to continue
+ * resending the rest of the retransmit queue, until either
+ * we've sent it all or the congestion window limit is reached.
+ * If doing SACK, the first ACK which comes back for a timeout
+ * based retransmit packet might feed us FACK information again.
+ * If so, we use it to avoid unnecessarily retransmissions.
+ */
+void tcp_xmit_retransmit_queue(struct sock *sk)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	struct sk_buff *hole = NULL;
+	u32 last_lost;
+	int mib_idx;
+	int fwd_rexmitting = 0;
+
+	if (!tp->lost_out)
+		tp->retransmit_high = tp->snd_una;
+
+	if (tp->retransmit_skb_hint) {
+		skb = tp->retransmit_skb_hint;
+		last_lost = TCP_SKB_CB(skb)->end_seq;
+		if (after(last_lost, tp->retransmit_high))
+			last_lost = tp->retransmit_high;
+	} else {
+		skb = tcp_write_queue_head(sk);
+		last_lost = tp->snd_una;
+	}
+
+	/* First pass: retransmit lost packets. */
+	tcp_for_write_queue_from(skb, sk) {
+		__u8 sacked = TCP_SKB_CB(skb)->sacked;
+
+		if (skb == tcp_send_head(sk))
+			break;
+		/* we could do better than to assign each time */
+		if (hole == NULL)
+			tp->retransmit_skb_hint = skb;
+
+		/* Assume this retransmit will generate
+		 * only one packet for congestion window
+		 * calculation purposes.  This works because
+		 * tcp_retransmit_skb() will chop up the
+		 * packet to be MSS sized and all the
+		 * packet counting works out.
+		 */
+		if (tcp_packets_in_flight(tp) >= tp->snd_cwnd)
+			return;
+
+		if (fwd_rexmitting) {
+begin_fwd:
+			if (!before(TCP_SKB_CB(skb)->seq, tcp_highest_sack_seq(tp)))
+				break;
+			mib_idx = LINUX_MIB_TCPFORWARDRETRANS;
+
+		} else if (!before(TCP_SKB_CB(skb)->seq, tp->retransmit_high)) {
+			tp->retransmit_high = last_lost;
+			if (!tcp_can_forward_retransmit(sk))
+				break;
+			/* Backtrack if necessary to non-L'ed skb */
+			if (hole != NULL) {
+				skb = hole;
+				hole = NULL;
+			}
+			fwd_rexmitting = 1;
+			goto begin_fwd;
+
+		} else if (!(sacked & TCPCB_LOST)) {
+			if (hole == NULL && !(sacked & TCPCB_SACKED_RETRANS))
+				hole = skb;
+			continue;
+
+		} else {
+			last_lost = TCP_SKB_CB(skb)->end_seq;
+			if (icsk->icsk_ca_state != TCP_CA_Loss)
+				mib_idx = LINUX_MIB_TCPFASTRETRANS;
+			else
+				mib_idx = LINUX_MIB_TCPSLOWSTARTRETRANS;
+		}
+
+		if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
+			continue;
+
+		if (tcp_retransmit_skb(sk, skb))
+			return;
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+
+		if (skb == tcp_write_queue_head(sk))
+			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+						  inet_csk(sk)->icsk_rto,
+						  TCP_RTO_MAX);
+	}
+}
+
+/* Send a fin.  The caller locks the socket for us.  This cannot be
+ * allowed to fail queueing a FIN frame under any circumstances.
+ */
+void tcp_send_fin(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb = tcp_write_queue_tail(sk);
+	int mss_now;
+
+	/* Optimization, tack on the FIN if we have a queue of
+	 * unsent frames.  But be careful about outgoing SACKS
+	 * and IP options.
+	 */
+	mss_now = tcp_current_mss(sk, 1);
+
+	if (tcp_send_head(sk) != NULL) {
+		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_FIN;
+		TCP_SKB_CB(skb)->end_seq++;
+		tp->write_seq++;
+	} else {
+		/* Socket is locked, keep trying until memory is available. */
+		for (;;) {
+			skb = alloc_skb_fclone(MAX_TCP_HEADER, GFP_KERNEL);
+			if (skb)
+				break;
+			yield();
+		}
+
+		/* Reserve space for headers and prepare control bits. */
+		skb_reserve(skb, MAX_TCP_HEADER);
+		/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
+		tcp_init_nondata_skb(skb, tp->write_seq,
+				     TCPCB_FLAG_ACK | TCPCB_FLAG_FIN);
+		tcp_queue_skb(sk, skb);
+	}
+	__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_OFF);
+}
+
+/* We get here when a process closes a file descriptor (either due to
+ * an explicit close() or as a byproduct of exit()'ing) and there
+ * was unread data in the receive queue.  This behavior is recommended
+ * by RFC 2525, section 2.17.  -DaveM
+ */
+void tcp_send_active_reset(struct sock *sk, gfp_t priority)
+{
+	struct sk_buff *skb;
+
+	/* NOTE: No TCP options attached and we never retransmit this. */
+	skb = alloc_skb(MAX_TCP_HEADER, priority);
+	if (!skb) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
+		return;
+	}
+
+	/* Reserve space for headers and prepare control bits. */
+	skb_reserve(skb, MAX_TCP_HEADER);
+	tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
+			     TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
+	/* Send it off. */
+	TCP_SKB_CB(skb)->when = tcp_time_stamp;
+	if (tcp_transmit_skb(sk, skb, 0, priority))
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
+
+	TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTRSTS);
+}
+
+/* WARNING: This routine must only be called when we have already sent
+ * a SYN packet that crossed the incoming SYN that caused this routine
+ * to get called. If this assumption fails then the initial rcv_wnd
+ * and rcv_wscale values will not be correct.
+ */
+int tcp_send_synack(struct sock *sk)
+{
+	struct sk_buff *skb;
+
+	skb = tcp_write_queue_head(sk);
+	if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_SYN)) {
+		printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
+		return -EFAULT;
+	}
+	if (!(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_ACK)) {
+		if (skb_cloned(skb)) {
+			struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
+			if (nskb == NULL)
+				return -ENOMEM;
+			tcp_unlink_write_queue(skb, sk);
+			skb_header_release(nskb);
+			__tcp_add_write_queue_head(sk, nskb);
+			sk_wmem_free_skb(sk, skb);
+			sk->sk_wmem_queued += nskb->truesize;
+			sk_mem_charge(sk, nskb->truesize);
+			skb = nskb;
+		}
+
+		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ACK;
+		TCP_ECN_send_synack(tcp_sk(sk), skb);
+	}
+	TCP_SKB_CB(skb)->when = tcp_time_stamp;
+	return tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
+}
+
+/*
+ * Prepare a SYN-ACK.
+ */
+struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
+				struct request_sock *req)
+{
+	struct inet_request_sock *ireq = inet_rsk(req);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcphdr *th;
+	int tcp_header_size;
+	struct tcp_out_options opts;
+	struct sk_buff *skb;
+	struct tcp_md5sig_key *md5;
+	__u8 *md5_hash_location;
+	int mss;
+
+	skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC);
+	if (skb == NULL)
+		return NULL;
+
+	/* Reserve space for headers. */
+	skb_reserve(skb, MAX_TCP_HEADER);
+
+	skb->dst = dst_clone(dst);
+
+	mss = dst_metric(dst, RTAX_ADVMSS);
+	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
+		mss = tp->rx_opt.user_mss;
+
+	if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */
+		__u8 rcv_wscale;
+		/* Set this up on the first call only */
+		req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
+		/* tcp_full_space because it is guaranteed to be the first packet */
+		tcp_select_initial_window(tcp_full_space(sk),
+			mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
+			&req->rcv_wnd,
+			&req->window_clamp,
+			ireq->wscale_ok,
+			&rcv_wscale);
+		ireq->rcv_wscale = rcv_wscale;
+	}
+
+	memset(&opts, 0, sizeof(opts));
+#ifdef CONFIG_SYN_COOKIES
+	if (unlikely(req->cookie_ts))
+		TCP_SKB_CB(skb)->when = cookie_init_timestamp(req);
+	else
+#endif
+	TCP_SKB_CB(skb)->when = tcp_time_stamp;
+	tcp_header_size = tcp_synack_options(sk, req, mss,
+					     skb, &opts, &md5) +
+			  sizeof(struct tcphdr);
+
+	skb_push(skb, tcp_header_size);
+	skb_reset_transport_header(skb);
+
+	th = tcp_hdr(skb);
+	memset(th, 0, sizeof(struct tcphdr));
+	th->syn = 1;
+	th->ack = 1;
+	TCP_ECN_make_synack(req, th);
+	th->source = ireq->loc_port;
+	th->dest = ireq->rmt_port;
+	/* Setting of flags are superfluous here for callers (and ECE is
+	 * not even correctly set)
+	 */
+	tcp_init_nondata_skb(skb, tcp_rsk(req)->snt_isn,
+			     TCPCB_FLAG_SYN | TCPCB_FLAG_ACK);
+	th->seq = htonl(TCP_SKB_CB(skb)->seq);
+	th->ack_seq = htonl(tcp_rsk(req)->rcv_isn + 1);
+
+	/* RFC1323: The window in SYN & SYN/ACK segments is never scaled. */
+	th->window = htons(min(req->rcv_wnd, 65535U));
+	tcp_options_write((__be32 *)(th + 1), tp, &opts, &md5_hash_location);
+	th->doff = (tcp_header_size >> 2);
+	TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTSEGS);
+
+#ifdef CONFIG_TCP_MD5SIG
+	/* Okay, we have all we need - do the md5 hash if needed */
+	if (md5) {
+		tp->af_specific->calc_md5_hash(md5_hash_location,
+					       md5, NULL, req, skb);
+	}
+#endif
+
+	return skb;
+}
+
+/*
+ * Do all connect socket setups that can be done AF independent.
+ */
+static void tcp_connect_init(struct sock *sk)
+{
+	struct dst_entry *dst = __sk_dst_get(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	__u8 rcv_wscale;
+
+	/* We'll fix this up when we get a response from the other end.
+	 * See tcp_input.c:tcp_rcv_state_process case TCP_SYN_SENT.
+	 */
+	tp->tcp_header_len = sizeof(struct tcphdr) +
+		(sysctl_tcp_timestamps ? TCPOLEN_TSTAMP_ALIGNED : 0);
+
+#ifdef CONFIG_TCP_MD5SIG
+	if (tp->af_specific->md5_lookup(sk, sk) != NULL)
+		tp->tcp_header_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
+	/* If user gave his TCP_MAXSEG, record it to clamp */
+	if (tp->rx_opt.user_mss)
+		tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;
+	tp->max_window = 0;
+	tcp_mtup_init(sk);
+	tcp_sync_mss(sk, dst_mtu(dst));
+
+	if (!tp->window_clamp)
+		tp->window_clamp = dst_metric(dst, RTAX_WINDOW);
+	tp->advmss = dst_metric(dst, RTAX_ADVMSS);
+	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < tp->advmss)
+		tp->advmss = tp->rx_opt.user_mss;
+
+	tcp_initialize_rcv_mss(sk);
+
+	tcp_select_initial_window(tcp_full_space(sk),
+				  tp->advmss - (tp->rx_opt.ts_recent_stamp ? tp->tcp_header_len - sizeof(struct tcphdr) : 0),
+				  &tp->rcv_wnd,
+				  &tp->window_clamp,
+				  sysctl_tcp_window_scaling,
+				  &rcv_wscale);
+
+	tp->rx_opt.rcv_wscale = rcv_wscale;
+	tp->rcv_ssthresh = tp->rcv_wnd;
+
+	sk->sk_err = 0;
+	sock_reset_flag(sk, SOCK_DONE);
+	tp->snd_wnd = 0;
+	tcp_init_wl(tp, tp->write_seq, 0);
+	tp->snd_una = tp->write_seq;
+	tp->snd_sml = tp->write_seq;
+	tp->snd_up = tp->write_seq;
+	tp->rcv_nxt = 0;
+	tp->rcv_wup = 0;
+	tp->copied_seq = 0;
+
+	inet_csk(sk)->icsk_rto = TCP_TIMEOUT_INIT;
+	inet_csk(sk)->icsk_retransmits = 0;
+	tcp_clear_retrans(tp);
+}
+
+/*
+ * Build a SYN and send it off.
+ */
+int tcp_connect(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *buff;
+
+	tcp_connect_init(sk);
+
+	buff = alloc_skb_fclone(MAX_TCP_HEADER + 15, sk->sk_allocation);
+	if (unlikely(buff == NULL))
+		return -ENOBUFS;
+
+	/* Reserve space for headers. */
+	skb_reserve(buff, MAX_TCP_HEADER);
+
+	tp->snd_nxt = tp->write_seq;
+	tcp_init_nondata_skb(buff, tp->write_seq++, TCPCB_FLAG_SYN);
+	TCP_ECN_send_syn(sk, buff);
+
+	/* Send it off. */
+	TCP_SKB_CB(buff)->when = tcp_time_stamp;
+	tp->retrans_stamp = TCP_SKB_CB(buff)->when;
+	skb_header_release(buff);
+	__tcp_add_write_queue_tail(sk, buff);
+	sk->sk_wmem_queued += buff->truesize;
+	sk_mem_charge(sk, buff->truesize);
+	tp->packets_out += tcp_skb_pcount(buff);
+	tcp_transmit_skb(sk, buff, 1, GFP_KERNEL);
+
+	/* We change tp->snd_nxt after the tcp_transmit_skb() call
+	 * in order to make this packet get counted in tcpOutSegs.
+	 */
+	tp->snd_nxt = tp->write_seq;
+	tp->pushed_seq = tp->write_seq;
+	TCP_INC_STATS(sock_net(sk), TCP_MIB_ACTIVEOPENS);
+
+	/* Timer for repeating the SYN until an answer. */
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+				  inet_csk(sk)->icsk_rto, TCP_RTO_MAX);
+	return 0;
+}
+
+/* Send out a delayed ack, the caller does the policy checking
+ * to see if we should even be here.  See tcp_input.c:tcp_ack_snd_check()
+ * for details.
+ */
+void tcp_send_delayed_ack(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int ato = icsk->icsk_ack.ato;
+	unsigned long timeout;
+
+	if (ato > TCP_DELACK_MIN) {
+		const struct tcp_sock *tp = tcp_sk(sk);
+		int max_ato = HZ / 2;
+
+		if (icsk->icsk_ack.pingpong ||
+		    (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
+			max_ato = TCP_DELACK_MAX;
+
+		/* Slow path, intersegment interval is "high". */
+
+		/* If some rtt estimate is known, use it to bound delayed ack.
+		 * Do not use inet_csk(sk)->icsk_rto here, use results of rtt measurements
+		 * directly.
+		 */
+		if (tp->srtt) {
+			int rtt = max(tp->srtt >> 3, TCP_DELACK_MIN);
+
+			if (rtt < max_ato)
+				max_ato = rtt;
+		}
+
+		ato = min(ato, max_ato);
+	}
+
+	/* Stay within the limit we were given */
+	timeout = jiffies + ato;
+
+	/* Use new timeout only if there wasn't a older one earlier. */
+	if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
+		/* If delack timer was blocked or is about to expire,
+		 * send ACK now.
+		 */
+		if (icsk->icsk_ack.blocked ||
+		    time_before_eq(icsk->icsk_ack.timeout, jiffies + (ato >> 2))) {
+			tcp_send_ack(sk);
+			return;
+		}
+
+		if (!time_before(timeout, icsk->icsk_ack.timeout))
+			timeout = icsk->icsk_ack.timeout;
+	}
+	icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
+	icsk->icsk_ack.timeout = timeout;
+	sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
+}
+
+/* This routine sends an ack and also updates the window. */
+void tcp_send_ack(struct sock *sk)
+{
+	struct sk_buff *buff;
+
+	/* If we have been reset, we may not send again. */
+	if (sk->sk_state == TCP_CLOSE)
+		return;
+
+	/* We are not putting this on the write queue, so
+	 * tcp_transmit_skb() will set the ownership to this
+	 * sock.
+	 */
+	buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+	if (buff == NULL) {
+		inet_csk_schedule_ack(sk);
+		inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
+					  TCP_DELACK_MAX, TCP_RTO_MAX);
+		return;
+	}
+
+	/* Reserve space for headers and prepare control bits. */
+	skb_reserve(buff, MAX_TCP_HEADER);
+	tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPCB_FLAG_ACK);
+
+	/* Send it off, this clears delayed acks for us. */
+	TCP_SKB_CB(buff)->when = tcp_time_stamp;
+	tcp_transmit_skb(sk, buff, 0, GFP_ATOMIC);
+}
+
+/* This routine sends a packet with an out of date sequence
+ * number. It assumes the other end will try to ack it.
+ *
+ * Question: what should we make while urgent mode?
+ * 4.4BSD forces sending single byte of data. We cannot send
+ * out of window data, because we have SND.NXT==SND.MAX...
+ *
+ * Current solution: to send TWO zero-length segments in urgent mode:
+ * one is with SEG.SEQ=SND.UNA to deliver urgent pointer, another is
+ * out-of-date with SND.UNA-1 to probe window.
+ */
+static int tcp_xmit_probe_skb(struct sock *sk, int urgent)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	/* We don't queue it, tcp_transmit_skb() sets ownership. */
+	skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+	if (skb == NULL)
+		return -1;
+
+	/* Reserve space for headers and set control bits. */
+	skb_reserve(skb, MAX_TCP_HEADER);
+	/* Use a previous sequence.  This should cause the other
+	 * end to send an ack.  Don't queue or clone SKB, just
+	 * send it.
+	 */
+	tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPCB_FLAG_ACK);
+	TCP_SKB_CB(skb)->when = tcp_time_stamp;
+	return tcp_transmit_skb(sk, skb, 0, GFP_ATOMIC);
+}
+
+int tcp_write_wakeup(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+
+	if (sk->sk_state == TCP_CLOSE)
+		return -1;
+
+	if ((skb = tcp_send_head(sk)) != NULL &&
+	    before(TCP_SKB_CB(skb)->seq, tcp_wnd_end(tp))) {
+		int err;
+		unsigned int mss = tcp_current_mss(sk, 0);
+		unsigned int seg_size = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
+
+		if (before(tp->pushed_seq, TCP_SKB_CB(skb)->end_seq))
+			tp->pushed_seq = TCP_SKB_CB(skb)->end_seq;
+
+		/* We are probing the opening of a window
+		 * but the window size is != 0
+		 * must have been a result SWS avoidance ( sender )
+		 */
+		if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq ||
+		    skb->len > mss) {
+			seg_size = min(seg_size, mss);
+			TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+			if (tcp_fragment(sk, skb, seg_size, mss))
+				return -1;
+		} else if (!tcp_skb_pcount(skb))
+			tcp_set_skb_tso_segs(sk, skb, mss);
+
+		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+		TCP_SKB_CB(skb)->when = tcp_time_stamp;
+		err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
+		if (!err)
+			tcp_event_new_data_sent(sk, skb);
+		return err;
+	} else {
+		if (between(tp->snd_up, tp->snd_una + 1, tp->snd_una + 0xFFFF))
+			tcp_xmit_probe_skb(sk, 1);
+		return tcp_xmit_probe_skb(sk, 0);
+	}
+}
+
+/* A window probe timeout has occurred.  If window is not closed send
+ * a partial packet else a zero probe.
+ */
+void tcp_send_probe0(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int err;
+
+	err = tcp_write_wakeup(sk);
+
+	if (tp->packets_out || !tcp_send_head(sk)) {
+		/* Cancel probe timer, if it is not required. */
+		icsk->icsk_probes_out = 0;
+		icsk->icsk_backoff = 0;
+		return;
+	}
+
+	if (err <= 0) {
+		if (icsk->icsk_backoff < sysctl_tcp_retries2)
+			icsk->icsk_backoff++;
+		icsk->icsk_probes_out++;
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+					  min(icsk->icsk_rto << icsk->icsk_backoff, TCP_RTO_MAX),
+					  TCP_RTO_MAX);
+	} else {
+		/* If packet was not sent due to local congestion,
+		 * do not backoff and do not remember icsk_probes_out.
+		 * Let local senders to fight for local resources.
+		 *
+		 * Use accumulated backoff yet.
+		 */
+		if (!icsk->icsk_probes_out)
+			icsk->icsk_probes_out = 1;
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
+					  min(icsk->icsk_rto << icsk->icsk_backoff,
+					      TCP_RESOURCE_PROBE_INTERVAL),
+					  TCP_RTO_MAX);
+	}
+}
+
+EXPORT_SYMBOL(tcp_select_initial_window);
+EXPORT_SYMBOL(tcp_connect);
+EXPORT_SYMBOL(tcp_make_synack);
+EXPORT_SYMBOL(tcp_simple_retransmit);
+EXPORT_SYMBOL(tcp_sync_mss);
+EXPORT_SYMBOL(tcp_mtup_init);
diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c
new file mode 100644
index 0000000..7ddc30f
--- /dev/null
+++ b/net/ipv4/tcp_probe.c
@@ -0,0 +1,254 @@
+/*
+ * tcpprobe - Observe the TCP flow with kprobes.
+ *
+ * The idea for this came from Werner Almesberger's umlsim
+ * Copyright (C) 2004, Stephen Hemminger <shemminger@osdl.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/socket.h>
+#include <linux/tcp.h>
+#include <linux/proc_fs.h>
+#include <linux/module.h>
+#include <linux/ktime.h>
+#include <linux/time.h>
+#include <net/net_namespace.h>
+
+#include <net/tcp.h>
+
+MODULE_AUTHOR("Stephen Hemminger <shemminger@linux-foundation.org>");
+MODULE_DESCRIPTION("TCP cwnd snooper");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.1");
+
+static int port __read_mostly = 0;
+MODULE_PARM_DESC(port, "Port to match (0=all)");
+module_param(port, int, 0);
+
+static int bufsize __read_mostly = 4096;
+MODULE_PARM_DESC(bufsize, "Log buffer size in packets (4096)");
+module_param(bufsize, int, 0);
+
+static int full __read_mostly;
+MODULE_PARM_DESC(full, "Full log (1=every ack packet received,  0=only cwnd changes)");
+module_param(full, int, 0);
+
+static const char procname[] = "tcpprobe";
+
+struct tcp_log {
+	ktime_t tstamp;
+	__be32	saddr, daddr;
+	__be16	sport, dport;
+	u16	length;
+	u32	snd_nxt;
+	u32	snd_una;
+	u32	snd_wnd;
+	u32	snd_cwnd;
+	u32	ssthresh;
+	u32	srtt;
+};
+
+static struct {
+	spinlock_t	lock;
+	wait_queue_head_t wait;
+	ktime_t		start;
+	u32		lastcwnd;
+
+	unsigned long	head, tail;
+	struct tcp_log	*log;
+} tcp_probe;
+
+
+static inline int tcp_probe_used(void)
+{
+	return (tcp_probe.head - tcp_probe.tail) % bufsize;
+}
+
+static inline int tcp_probe_avail(void)
+{
+	return bufsize - tcp_probe_used();
+}
+
+/*
+ * Hook inserted to be called before each receive packet.
+ * Note: arguments must match tcp_rcv_established()!
+ */
+static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
+			       struct tcphdr *th, unsigned len)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct inet_sock *inet = inet_sk(sk);
+
+	/* Only update if port matches */
+	if ((port == 0 || ntohs(inet->dport) == port || ntohs(inet->sport) == port)
+	    && (full || tp->snd_cwnd != tcp_probe.lastcwnd)) {
+
+		spin_lock(&tcp_probe.lock);
+		/* If log fills, just silently drop */
+		if (tcp_probe_avail() > 1) {
+			struct tcp_log *p = tcp_probe.log + tcp_probe.head;
+
+			p->tstamp = ktime_get();
+			p->saddr = inet->saddr;
+			p->sport = inet->sport;
+			p->daddr = inet->daddr;
+			p->dport = inet->dport;
+			p->length = skb->len;
+			p->snd_nxt = tp->snd_nxt;
+			p->snd_una = tp->snd_una;
+			p->snd_cwnd = tp->snd_cwnd;
+			p->snd_wnd = tp->snd_wnd;
+			p->ssthresh = tcp_current_ssthresh(sk);
+			p->srtt = tp->srtt >> 3;
+
+			tcp_probe.head = (tcp_probe.head + 1) % bufsize;
+		}
+		tcp_probe.lastcwnd = tp->snd_cwnd;
+		spin_unlock(&tcp_probe.lock);
+
+		wake_up(&tcp_probe.wait);
+	}
+
+	jprobe_return();
+	return 0;
+}
+
+static struct jprobe tcp_jprobe = {
+	.kp = {
+		.symbol_name	= "tcp_rcv_established",
+	},
+	.entry	= jtcp_rcv_established,
+};
+
+static int tcpprobe_open(struct inode * inode, struct file * file)
+{
+	/* Reset (empty) log */
+	spin_lock_bh(&tcp_probe.lock);
+	tcp_probe.head = tcp_probe.tail = 0;
+	tcp_probe.start = ktime_get();
+	spin_unlock_bh(&tcp_probe.lock);
+
+	return 0;
+}
+
+static int tcpprobe_sprint(char *tbuf, int n)
+{
+	const struct tcp_log *p
+		= tcp_probe.log + tcp_probe.tail % bufsize;
+	struct timespec tv
+		= ktime_to_timespec(ktime_sub(p->tstamp, tcp_probe.start));
+
+	return snprintf(tbuf, n,
+			"%lu.%09lu " NIPQUAD_FMT ":%u " NIPQUAD_FMT ":%u"
+			" %d %#x %#x %u %u %u %u\n",
+			(unsigned long) tv.tv_sec,
+			(unsigned long) tv.tv_nsec,
+			NIPQUAD(p->saddr), ntohs(p->sport),
+			NIPQUAD(p->daddr), ntohs(p->dport),
+			p->length, p->snd_nxt, p->snd_una,
+			p->snd_cwnd, p->ssthresh, p->snd_wnd, p->srtt);
+}
+
+static ssize_t tcpprobe_read(struct file *file, char __user *buf,
+			     size_t len, loff_t *ppos)
+{
+	int error = 0, cnt = 0;
+
+	if (!buf || len < 0)
+		return -EINVAL;
+
+	while (cnt < len) {
+		char tbuf[128];
+		int width;
+
+		/* Wait for data in buffer */
+		error = wait_event_interruptible(tcp_probe.wait,
+						 tcp_probe_used() > 0);
+		if (error)
+			break;
+
+		spin_lock_bh(&tcp_probe.lock);
+		if (tcp_probe.head == tcp_probe.tail) {
+			/* multiple readers race? */
+			spin_unlock_bh(&tcp_probe.lock);
+			continue;
+		}
+
+		width = tcpprobe_sprint(tbuf, sizeof(tbuf));
+
+		if (cnt + width < len)
+			tcp_probe.tail = (tcp_probe.tail + 1) % bufsize;
+
+		spin_unlock_bh(&tcp_probe.lock);
+
+		/* if record greater than space available
+		   return partial buffer (so far) */
+		if (cnt + width >= len)
+			break;
+
+		if (copy_to_user(buf + cnt, tbuf, width))
+			return -EFAULT;
+		cnt += width;
+	}
+
+	return cnt == 0 ? error : cnt;
+}
+
+static const struct file_operations tcpprobe_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = tcpprobe_open,
+	.read    = tcpprobe_read,
+};
+
+static __init int tcpprobe_init(void)
+{
+	int ret = -ENOMEM;
+
+	init_waitqueue_head(&tcp_probe.wait);
+	spin_lock_init(&tcp_probe.lock);
+
+	if (bufsize < 0)
+		return -EINVAL;
+
+	tcp_probe.log = kcalloc(bufsize, sizeof(struct tcp_log), GFP_KERNEL);
+	if (!tcp_probe.log)
+		goto err0;
+
+	if (!proc_net_fops_create(&init_net, procname, S_IRUSR, &tcpprobe_fops))
+		goto err0;
+
+	ret = register_jprobe(&tcp_jprobe);
+	if (ret)
+		goto err1;
+
+	pr_info("TCP probe registered (port=%d)\n", port);
+	return 0;
+ err1:
+	proc_net_remove(&init_net, procname);
+ err0:
+	kfree(tcp_probe.log);
+	return ret;
+}
+module_init(tcpprobe_init);
+
+static __exit void tcpprobe_exit(void)
+{
+	proc_net_remove(&init_net, procname);
+	unregister_jprobe(&tcp_jprobe);
+	kfree(tcp_probe.log);
+}
+module_exit(tcpprobe_exit);
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
new file mode 100644
index 0000000..2747ec7
--- /dev/null
+++ b/net/ipv4/tcp_scalable.c
@@ -0,0 +1,68 @@
+/* Tom Kelly's Scalable TCP
+ *
+ * See htt://www-lce.eng.cam.ac.uk/~ctk21/scalable/
+ *
+ * John Heffner <jheffner@sc.edu>
+ */
+
+#include <linux/module.h>
+#include <net/tcp.h>
+
+/* These factors derived from the recommended values in the aer:
+ * .01 and and 7/8. We use 50 instead of 100 to account for
+ * delayed ack.
+ */
+#define TCP_SCALABLE_AI_CNT	50U
+#define TCP_SCALABLE_MD_SCALE	3
+
+static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+	else {
+		tp->snd_cwnd_cnt++;
+		if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+		}
+	}
+}
+
+static u32 tcp_scalable_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	return max(tp->snd_cwnd - (tp->snd_cwnd>>TCP_SCALABLE_MD_SCALE), 2U);
+}
+
+
+static struct tcp_congestion_ops tcp_scalable = {
+	.ssthresh	= tcp_scalable_ssthresh,
+	.cong_avoid	= tcp_scalable_cong_avoid,
+	.min_cwnd	= tcp_reno_min_cwnd,
+
+	.owner		= THIS_MODULE,
+	.name		= "scalable",
+};
+
+static int __init tcp_scalable_register(void)
+{
+	return tcp_register_congestion_control(&tcp_scalable);
+}
+
+static void __exit tcp_scalable_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_scalable);
+}
+
+module_init(tcp_scalable_register);
+module_exit(tcp_scalable_unregister);
+
+MODULE_AUTHOR("John Heffner");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Scalable TCP");
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
new file mode 100644
index 0000000..6b6dff1
--- /dev/null
+++ b/net/ipv4/tcp_timer.c
@@ -0,0 +1,538 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *		Corey Minyard <wf-rch!minyard@relay.EU.net>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ *		Linus Torvalds, <torvalds@cs.helsinki.fi>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Matthew Dillon, <dillon@apollo.west.oic.com>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ */
+
+#include <linux/module.h>
+#include <net/tcp.h>
+
+int sysctl_tcp_syn_retries __read_mostly = TCP_SYN_RETRIES;
+int sysctl_tcp_synack_retries __read_mostly = TCP_SYNACK_RETRIES;
+int sysctl_tcp_keepalive_time __read_mostly = TCP_KEEPALIVE_TIME;
+int sysctl_tcp_keepalive_probes __read_mostly = TCP_KEEPALIVE_PROBES;
+int sysctl_tcp_keepalive_intvl __read_mostly = TCP_KEEPALIVE_INTVL;
+int sysctl_tcp_retries1 __read_mostly = TCP_RETR1;
+int sysctl_tcp_retries2 __read_mostly = TCP_RETR2;
+int sysctl_tcp_orphan_retries __read_mostly;
+
+static void tcp_write_timer(unsigned long);
+static void tcp_delack_timer(unsigned long);
+static void tcp_keepalive_timer (unsigned long data);
+
+void tcp_init_xmit_timers(struct sock *sk)
+{
+	inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer,
+				  &tcp_keepalive_timer);
+}
+
+EXPORT_SYMBOL(tcp_init_xmit_timers);
+
+static void tcp_write_err(struct sock *sk)
+{
+	sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT;
+	sk->sk_error_report(sk);
+
+	tcp_done(sk);
+	NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONTIMEOUT);
+}
+
+/* Do not allow orphaned sockets to eat all our resources.
+ * This is direct violation of TCP specs, but it is required
+ * to prevent DoS attacks. It is called when a retransmission timeout
+ * or zero probe timeout occurs on orphaned socket.
+ *
+ * Criteria is still not confirmed experimentally and may change.
+ * We kill the socket, if:
+ * 1. If number of orphaned sockets exceeds an administratively configured
+ *    limit.
+ * 2. If we have strong memory pressure.
+ */
+static int tcp_out_of_resources(struct sock *sk, int do_reset)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int orphans = atomic_read(&tcp_orphan_count);
+
+	/* If peer does not open window for long time, or did not transmit
+	 * anything for long time, penalize it. */
+	if ((s32)(tcp_time_stamp - tp->lsndtime) > 2*TCP_RTO_MAX || !do_reset)
+		orphans <<= 1;
+
+	/* If some dubious ICMP arrived, penalize even more. */
+	if (sk->sk_err_soft)
+		orphans <<= 1;
+
+	if (tcp_too_many_orphans(sk, orphans)) {
+		if (net_ratelimit())
+			printk(KERN_INFO "Out of socket memory\n");
+
+		/* Catch exceptional cases, when connection requires reset.
+		 *      1. Last segment was sent recently. */
+		if ((s32)(tcp_time_stamp - tp->lsndtime) <= TCP_TIMEWAIT_LEN ||
+		    /*  2. Window is closed. */
+		    (!tp->snd_wnd && !tp->packets_out))
+			do_reset = 1;
+		if (do_reset)
+			tcp_send_active_reset(sk, GFP_ATOMIC);
+		tcp_done(sk);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY);
+		return 1;
+	}
+	return 0;
+}
+
+/* Calculate maximal number or retries on an orphaned socket. */
+static int tcp_orphan_retries(struct sock *sk, int alive)
+{
+	int retries = sysctl_tcp_orphan_retries; /* May be zero. */
+
+	/* We know from an ICMP that something is wrong. */
+	if (sk->sk_err_soft && !alive)
+		retries = 0;
+
+	/* However, if socket sent something recently, select some safe
+	 * number of retries. 8 corresponds to >100 seconds with minimal
+	 * RTO of 200msec. */
+	if (retries == 0 && alive)
+		retries = 8;
+	return retries;
+}
+
+static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
+{
+	/* Black hole detection */
+	if (sysctl_tcp_mtu_probing) {
+		if (!icsk->icsk_mtup.enabled) {
+			icsk->icsk_mtup.enabled = 1;
+			tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+		} else {
+			struct tcp_sock *tp = tcp_sk(sk);
+			int mss;
+
+			mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1;
+			mss = min(sysctl_tcp_base_mss, mss);
+			mss = max(mss, 68 - tp->tcp_header_len);
+			icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);
+			tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
+		}
+	}
+}
+
+/* A write timeout has occurred. Process the after effects. */
+static int tcp_write_timeout(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int retry_until;
+
+	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		if (icsk->icsk_retransmits)
+			dst_negative_advice(&sk->sk_dst_cache);
+		retry_until = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
+	} else {
+		if (icsk->icsk_retransmits >= sysctl_tcp_retries1) {
+			/* Black hole detection */
+			tcp_mtu_probing(icsk, sk);
+
+			dst_negative_advice(&sk->sk_dst_cache);
+		}
+
+		retry_until = sysctl_tcp_retries2;
+		if (sock_flag(sk, SOCK_DEAD)) {
+			const int alive = (icsk->icsk_rto < TCP_RTO_MAX);
+
+			retry_until = tcp_orphan_retries(sk, alive);
+
+			if (tcp_out_of_resources(sk, alive || icsk->icsk_retransmits < retry_until))
+				return 1;
+		}
+	}
+
+	if (icsk->icsk_retransmits >= retry_until) {
+		/* Has it gone just too far? */
+		tcp_write_err(sk);
+		return 1;
+	}
+	return 0;
+}
+
+static void tcp_delack_timer(unsigned long data)
+{
+	struct sock *sk = (struct sock*)data;
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk)) {
+		/* Try again later. */
+		icsk->icsk_ack.blocked = 1;
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);
+		sk_reset_timer(sk, &icsk->icsk_delack_timer, jiffies + TCP_DELACK_MIN);
+		goto out_unlock;
+	}
+
+	sk_mem_reclaim_partial(sk);
+
+	if (sk->sk_state == TCP_CLOSE || !(icsk->icsk_ack.pending & ICSK_ACK_TIMER))
+		goto out;
+
+	if (time_after(icsk->icsk_ack.timeout, jiffies)) {
+		sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
+		goto out;
+	}
+	icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER;
+
+	if (!skb_queue_empty(&tp->ucopy.prequeue)) {
+		struct sk_buff *skb;
+
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSCHEDULERFAILED);
+
+		while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
+			sk_backlog_rcv(sk, skb);
+
+		tp->ucopy.memory = 0;
+	}
+
+	if (inet_csk_ack_scheduled(sk)) {
+		if (!icsk->icsk_ack.pingpong) {
+			/* Delayed ACK missed: inflate ATO. */
+			icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1, icsk->icsk_rto);
+		} else {
+			/* Delayed ACK missed: leave pingpong mode and
+			 * deflate ATO.
+			 */
+			icsk->icsk_ack.pingpong = 0;
+			icsk->icsk_ack.ato      = TCP_ATO_MIN;
+		}
+		tcp_send_ack(sk);
+		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_DELAYEDACKS);
+	}
+	TCP_CHECK_TIMER(sk);
+
+out:
+	if (tcp_memory_pressure)
+		sk_mem_reclaim(sk);
+out_unlock:
+	bh_unlock_sock(sk);
+	sock_put(sk);
+}
+
+static void tcp_probe_timer(struct sock *sk)
+{
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int max_probes;
+
+	if (tp->packets_out || !tcp_send_head(sk)) {
+		icsk->icsk_probes_out = 0;
+		return;
+	}
+
+	/* *WARNING* RFC 1122 forbids this
+	 *
+	 * It doesn't AFAIK, because we kill the retransmit timer -AK
+	 *
+	 * FIXME: We ought not to do it, Solaris 2.5 actually has fixing
+	 * this behaviour in Solaris down as a bug fix. [AC]
+	 *
+	 * Let me to explain. icsk_probes_out is zeroed by incoming ACKs
+	 * even if they advertise zero window. Hence, connection is killed only
+	 * if we received no ACKs for normal connection timeout. It is not killed
+	 * only because window stays zero for some time, window may be zero
+	 * until armageddon and even later. We are in full accordance
+	 * with RFCs, only probe timer combines both retransmission timeout
+	 * and probe timeout in one bottle.				--ANK
+	 */
+	max_probes = sysctl_tcp_retries2;
+
+	if (sock_flag(sk, SOCK_DEAD)) {
+		const int alive = ((icsk->icsk_rto << icsk->icsk_backoff) < TCP_RTO_MAX);
+
+		max_probes = tcp_orphan_retries(sk, alive);
+
+		if (tcp_out_of_resources(sk, alive || icsk->icsk_probes_out <= max_probes))
+			return;
+	}
+
+	if (icsk->icsk_probes_out > max_probes) {
+		tcp_write_err(sk);
+	} else {
+		/* Only send another probe if we didn't close things up. */
+		tcp_send_probe0(sk);
+	}
+}
+
+/*
+ *	The TCP retransmit timer.
+ */
+
+static void tcp_retransmit_timer(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
+
+	if (!tp->packets_out)
+		goto out;
+
+	WARN_ON(tcp_write_queue_empty(sk));
+
+	if (!tp->snd_wnd && !sock_flag(sk, SOCK_DEAD) &&
+	    !((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))) {
+		/* Receiver dastardly shrinks window. Our retransmits
+		 * become zero probes, but we should not timeout this
+		 * connection. If the socket is an orphan, time it out,
+		 * we cannot allow such beasts to hang infinitely.
+		 */
+#ifdef TCP_DEBUG
+		struct inet_sock *inet = inet_sk(sk);
+		if (sk->sk_family == AF_INET) {
+			LIMIT_NETDEBUG(KERN_DEBUG "TCP: Treason uncloaked! Peer " NIPQUAD_FMT ":%u/%u shrinks window %u:%u. Repaired.\n",
+			       NIPQUAD(inet->daddr), ntohs(inet->dport),
+			       inet->num, tp->snd_una, tp->snd_nxt);
+		}
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+		else if (sk->sk_family == AF_INET6) {
+			struct ipv6_pinfo *np = inet6_sk(sk);
+			LIMIT_NETDEBUG(KERN_DEBUG "TCP: Treason uncloaked! Peer " NIP6_FMT ":%u/%u shrinks window %u:%u. Repaired.\n",
+			       NIP6(np->daddr), ntohs(inet->dport),
+			       inet->num, tp->snd_una, tp->snd_nxt);
+		}
+#endif
+#endif
+		if (tcp_time_stamp - tp->rcv_tstamp > TCP_RTO_MAX) {
+			tcp_write_err(sk);
+			goto out;
+		}
+		tcp_enter_loss(sk, 0);
+		tcp_retransmit_skb(sk, tcp_write_queue_head(sk));
+		__sk_dst_reset(sk);
+		goto out_reset_timer;
+	}
+
+	if (tcp_write_timeout(sk))
+		goto out;
+
+	if (icsk->icsk_retransmits == 0) {
+		int mib_idx;
+
+		if (icsk->icsk_ca_state == TCP_CA_Disorder ||
+		    icsk->icsk_ca_state == TCP_CA_Recovery) {
+			if (tcp_is_sack(tp)) {
+				if (icsk->icsk_ca_state == TCP_CA_Recovery)
+					mib_idx = LINUX_MIB_TCPSACKRECOVERYFAIL;
+				else
+					mib_idx = LINUX_MIB_TCPSACKFAILURES;
+			} else {
+				if (icsk->icsk_ca_state == TCP_CA_Recovery)
+					mib_idx = LINUX_MIB_TCPRENORECOVERYFAIL;
+				else
+					mib_idx = LINUX_MIB_TCPRENOFAILURES;
+			}
+		} else if (icsk->icsk_ca_state == TCP_CA_Loss) {
+			mib_idx = LINUX_MIB_TCPLOSSFAILURES;
+		} else {
+			mib_idx = LINUX_MIB_TCPTIMEOUTS;
+		}
+		NET_INC_STATS_BH(sock_net(sk), mib_idx);
+	}
+
+	if (tcp_use_frto(sk)) {
+		tcp_enter_frto(sk);
+	} else {
+		tcp_enter_loss(sk, 0);
+	}
+
+	if (tcp_retransmit_skb(sk, tcp_write_queue_head(sk)) > 0) {
+		/* Retransmission failed because of local congestion,
+		 * do not backoff.
+		 */
+		if (!icsk->icsk_retransmits)
+			icsk->icsk_retransmits = 1;
+		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+					  min(icsk->icsk_rto, TCP_RESOURCE_PROBE_INTERVAL),
+					  TCP_RTO_MAX);
+		goto out;
+	}
+
+	/* Increase the timeout each time we retransmit.  Note that
+	 * we do not increase the rtt estimate.  rto is initialized
+	 * from rtt, but increases here.  Jacobson (SIGCOMM 88) suggests
+	 * that doubling rto each time is the least we can get away with.
+	 * In KA9Q, Karn uses this for the first few times, and then
+	 * goes to quadratic.  netBSD doubles, but only goes up to *64,
+	 * and clamps at 1 to 64 sec afterwards.  Note that 120 sec is
+	 * defined in the protocol as the maximum possible RTT.  I guess
+	 * we'll have to use something other than TCP to talk to the
+	 * University of Mars.
+	 *
+	 * PAWS allows us longer timeouts and large windows, so once
+	 * implemented ftp to mars will work nicely. We will have to fix
+	 * the 120 second clamps though!
+	 */
+	icsk->icsk_backoff++;
+	icsk->icsk_retransmits++;
+
+out_reset_timer:
+	icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);
+	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX);
+	if (icsk->icsk_retransmits > sysctl_tcp_retries1)
+		__sk_dst_reset(sk);
+
+out:;
+}
+
+static void tcp_write_timer(unsigned long data)
+{
+	struct sock *sk = (struct sock*)data;
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	int event;
+
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk)) {
+		/* Try again later */
+		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + (HZ / 20));
+		goto out_unlock;
+	}
+
+	if (sk->sk_state == TCP_CLOSE || !icsk->icsk_pending)
+		goto out;
+
+	if (time_after(icsk->icsk_timeout, jiffies)) {
+		sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
+		goto out;
+	}
+
+	event = icsk->icsk_pending;
+	icsk->icsk_pending = 0;
+
+	switch (event) {
+	case ICSK_TIME_RETRANS:
+		tcp_retransmit_timer(sk);
+		break;
+	case ICSK_TIME_PROBE0:
+		tcp_probe_timer(sk);
+		break;
+	}
+	TCP_CHECK_TIMER(sk);
+
+out:
+	sk_mem_reclaim(sk);
+out_unlock:
+	bh_unlock_sock(sk);
+	sock_put(sk);
+}
+
+/*
+ *	Timer for listening sockets
+ */
+
+static void tcp_synack_timer(struct sock *sk)
+{
+	inet_csk_reqsk_queue_prune(sk, TCP_SYNQ_INTERVAL,
+				   TCP_TIMEOUT_INIT, TCP_RTO_MAX);
+}
+
+void tcp_set_keepalive(struct sock *sk, int val)
+{
+	if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))
+		return;
+
+	if (val && !sock_flag(sk, SOCK_KEEPOPEN))
+		inet_csk_reset_keepalive_timer(sk, keepalive_time_when(tcp_sk(sk)));
+	else if (!val)
+		inet_csk_delete_keepalive_timer(sk);
+}
+
+
+static void tcp_keepalive_timer (unsigned long data)
+{
+	struct sock *sk = (struct sock *) data;
+	struct inet_connection_sock *icsk = inet_csk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	__u32 elapsed;
+
+	/* Only process if socket is not in use. */
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk)) {
+		/* Try again later. */
+		inet_csk_reset_keepalive_timer (sk, HZ/20);
+		goto out;
+	}
+
+	if (sk->sk_state == TCP_LISTEN) {
+		tcp_synack_timer(sk);
+		goto out;
+	}
+
+	if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) {
+		if (tp->linger2 >= 0) {
+			const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN;
+
+			if (tmo > 0) {
+				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
+				goto out;
+			}
+		}
+		tcp_send_active_reset(sk, GFP_ATOMIC);
+		goto death;
+	}
+
+	if (!sock_flag(sk, SOCK_KEEPOPEN) || sk->sk_state == TCP_CLOSE)
+		goto out;
+
+	elapsed = keepalive_time_when(tp);
+
+	/* It is alive without keepalive 8) */
+	if (tp->packets_out || tcp_send_head(sk))
+		goto resched;
+
+	elapsed = tcp_time_stamp - tp->rcv_tstamp;
+
+	if (elapsed >= keepalive_time_when(tp)) {
+		if ((!tp->keepalive_probes && icsk->icsk_probes_out >= sysctl_tcp_keepalive_probes) ||
+		     (tp->keepalive_probes && icsk->icsk_probes_out >= tp->keepalive_probes)) {
+			tcp_send_active_reset(sk, GFP_ATOMIC);
+			tcp_write_err(sk);
+			goto out;
+		}
+		if (tcp_write_wakeup(sk) <= 0) {
+			icsk->icsk_probes_out++;
+			elapsed = keepalive_intvl_when(tp);
+		} else {
+			/* If keepalive was lost due to local congestion,
+			 * try harder.
+			 */
+			elapsed = TCP_RESOURCE_PROBE_INTERVAL;
+		}
+	} else {
+		/* It is tp->rcv_tstamp + keepalive_time_when(tp) */
+		elapsed = keepalive_time_when(tp) - elapsed;
+	}
+
+	TCP_CHECK_TIMER(sk);
+	sk_mem_reclaim(sk);
+
+resched:
+	inet_csk_reset_keepalive_timer (sk, elapsed);
+	goto out;
+
+death:
+	tcp_done(sk);
+
+out:
+	bh_unlock_sock(sk);
+	sock_put(sk);
+}
diff --git a/net/ipv4/tcp_vegas.c b/net/ipv4/tcp_vegas.c
new file mode 100644
index 0000000..a453aac
--- /dev/null
+++ b/net/ipv4/tcp_vegas.c
@@ -0,0 +1,332 @@
+/*
+ * TCP Vegas congestion control
+ *
+ * This is based on the congestion detection/avoidance scheme described in
+ *    Lawrence S. Brakmo and Larry L. Peterson.
+ *    "TCP Vegas: End to end congestion avoidance on a global internet."
+ *    IEEE Journal on Selected Areas in Communication, 13(8):1465--1480,
+ *    October 1995. Available from:
+ *	ftp://ftp.cs.arizona.edu/xkernel/Papers/jsac.ps
+ *
+ * See http://www.cs.arizona.edu/xkernel/ for their implementation.
+ * The main aspects that distinguish this implementation from the
+ * Arizona Vegas implementation are:
+ *   o We do not change the loss detection or recovery mechanisms of
+ *     Linux in any way. Linux already recovers from losses quite well,
+ *     using fine-grained timers, NewReno, and FACK.
+ *   o To avoid the performance penalty imposed by increasing cwnd
+ *     only every-other RTT during slow start, we increase during
+ *     every RTT during slow start, just like Reno.
+ *   o Largely to allow continuous cwnd growth during slow start,
+ *     we use the rate at which ACKs come back as the "actual"
+ *     rate, rather than the rate at which data is sent.
+ *   o To speed convergence to the right rate, we set the cwnd
+ *     to achieve the right ("actual") rate when we exit slow start.
+ *   o To filter out the noise caused by delayed ACKs, we use the
+ *     minimum RTT sample observed during the last RTT to calculate
+ *     the actual rate.
+ *   o When the sender re-starts from idle, it waits until it has
+ *     received ACKs for an entire flight of new data before making
+ *     a cwnd adjustment decision. The original Vegas implementation
+ *     assumed senders never went idle.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+
+#include <net/tcp.h>
+
+#include "tcp_vegas.h"
+
+static int alpha = 2;
+static int beta  = 4;
+static int gamma = 1;
+
+module_param(alpha, int, 0644);
+MODULE_PARM_DESC(alpha, "lower bound of packets in network");
+module_param(beta, int, 0644);
+MODULE_PARM_DESC(beta, "upper bound of packets in network");
+module_param(gamma, int, 0644);
+MODULE_PARM_DESC(gamma, "limit on increase (scale by 2)");
+
+
+/* There are several situations when we must "re-start" Vegas:
+ *
+ *  o when a connection is established
+ *  o after an RTO
+ *  o after fast recovery
+ *  o when we send a packet and there is no outstanding
+ *    unacknowledged data (restarting an idle connection)
+ *
+ * In these circumstances we cannot do a Vegas calculation at the
+ * end of the first RTT, because any calculation we do is using
+ * stale info -- both the saved cwnd and congestion feedback are
+ * stale.
+ *
+ * Instead we must wait until the completion of an RTT during
+ * which we actually receive ACKs.
+ */
+static void vegas_enable(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct vegas *vegas = inet_csk_ca(sk);
+
+	/* Begin taking Vegas samples next time we send something. */
+	vegas->doing_vegas_now = 1;
+
+	/* Set the beginning of the next send window. */
+	vegas->beg_snd_nxt = tp->snd_nxt;
+
+	vegas->cntRTT = 0;
+	vegas->minRTT = 0x7fffffff;
+}
+
+/* Stop taking Vegas samples for now. */
+static inline void vegas_disable(struct sock *sk)
+{
+	struct vegas *vegas = inet_csk_ca(sk);
+
+	vegas->doing_vegas_now = 0;
+}
+
+void tcp_vegas_init(struct sock *sk)
+{
+	struct vegas *vegas = inet_csk_ca(sk);
+
+	vegas->baseRTT = 0x7fffffff;
+	vegas_enable(sk);
+}
+EXPORT_SYMBOL_GPL(tcp_vegas_init);
+
+/* Do RTT sampling needed for Vegas.
+ * Basically we:
+ *   o min-filter RTT samples from within an RTT to get the current
+ *     propagation delay + queuing delay (we are min-filtering to try to
+ *     avoid the effects of delayed ACKs)
+ *   o min-filter RTT samples from a much longer window (forever for now)
+ *     to find the propagation delay (baseRTT)
+ */
+void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us)
+{
+	struct vegas *vegas = inet_csk_ca(sk);
+	u32 vrtt;
+
+	if (rtt_us < 0)
+		return;
+
+	/* Never allow zero rtt or baseRTT */
+	vrtt = rtt_us + 1;
+
+	/* Filter to find propagation delay: */
+	if (vrtt < vegas->baseRTT)
+		vegas->baseRTT = vrtt;
+
+	/* Find the min RTT during the last RTT to find
+	 * the current prop. delay + queuing delay:
+	 */
+	vegas->minRTT = min(vegas->minRTT, vrtt);
+	vegas->cntRTT++;
+}
+EXPORT_SYMBOL_GPL(tcp_vegas_pkts_acked);
+
+void tcp_vegas_state(struct sock *sk, u8 ca_state)
+{
+
+	if (ca_state == TCP_CA_Open)
+		vegas_enable(sk);
+	else
+		vegas_disable(sk);
+}
+EXPORT_SYMBOL_GPL(tcp_vegas_state);
+
+/*
+ * If the connection is idle and we are restarting,
+ * then we don't want to do any Vegas calculations
+ * until we get fresh RTT samples.  So when we
+ * restart, we reset our Vegas state to a clean
+ * slate. After we get acks for this flight of
+ * packets, _then_ we can make Vegas calculations
+ * again.
+ */
+void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event)
+{
+	if (event == CA_EVENT_CWND_RESTART ||
+	    event == CA_EVENT_TX_START)
+		tcp_vegas_init(sk);
+}
+EXPORT_SYMBOL_GPL(tcp_vegas_cwnd_event);
+
+static void tcp_vegas_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct vegas *vegas = inet_csk_ca(sk);
+
+	if (!vegas->doing_vegas_now) {
+		tcp_reno_cong_avoid(sk, ack, in_flight);
+		return;
+	}
+
+	if (after(ack, vegas->beg_snd_nxt)) {
+		/* Do the Vegas once-per-RTT cwnd adjustment. */
+
+		/* Save the extent of the current window so we can use this
+		 * at the end of the next RTT.
+		 */
+		vegas->beg_snd_nxt  = tp->snd_nxt;
+
+		/* We do the Vegas calculations only if we got enough RTT
+		 * samples that we can be reasonably sure that we got
+		 * at least one RTT sample that wasn't from a delayed ACK.
+		 * If we only had 2 samples total,
+		 * then that means we're getting only 1 ACK per RTT, which
+		 * means they're almost certainly delayed ACKs.
+		 * If  we have 3 samples, we should be OK.
+		 */
+
+		if (vegas->cntRTT <= 2) {
+			/* We don't have enough RTT samples to do the Vegas
+			 * calculation, so we'll behave like Reno.
+			 */
+			tcp_reno_cong_avoid(sk, ack, in_flight);
+		} else {
+			u32 rtt, diff;
+			u64 target_cwnd;
+
+			/* We have enough RTT samples, so, using the Vegas
+			 * algorithm, we determine if we should increase or
+			 * decrease cwnd, and by how much.
+			 */
+
+			/* Pluck out the RTT we are using for the Vegas
+			 * calculations. This is the min RTT seen during the
+			 * last RTT. Taking the min filters out the effects
+			 * of delayed ACKs, at the cost of noticing congestion
+			 * a bit later.
+			 */
+			rtt = vegas->minRTT;
+
+			/* Calculate the cwnd we should have, if we weren't
+			 * going too fast.
+			 *
+			 * This is:
+			 *     (actual rate in segments) * baseRTT
+			 */
+			target_cwnd = tp->snd_cwnd * vegas->baseRTT / rtt;
+
+			/* Calculate the difference between the window we had,
+			 * and the window we would like to have. This quantity
+			 * is the "Diff" from the Arizona Vegas papers.
+			 */
+			diff = tp->snd_cwnd * (rtt-vegas->baseRTT) / vegas->baseRTT;
+
+			if (diff > gamma && tp->snd_ssthresh > 2 ) {
+				/* Going too fast. Time to slow down
+				 * and switch to congestion avoidance.
+				 */
+				tp->snd_ssthresh = 2;
+
+				/* Set cwnd to match the actual rate
+				 * exactly:
+				 *   cwnd = (actual rate) * baseRTT
+				 * Then we add 1 because the integer
+				 * truncation robs us of full link
+				 * utilization.
+				 */
+				tp->snd_cwnd = min(tp->snd_cwnd, (u32)target_cwnd+1);
+
+			} else if (tp->snd_cwnd <= tp->snd_ssthresh) {
+				/* Slow start.  */
+				tcp_slow_start(tp);
+			} else {
+				/* Congestion avoidance. */
+
+				/* Figure out where we would like cwnd
+				 * to be.
+				 */
+				if (diff > beta) {
+					/* The old window was too fast, so
+					 * we slow down.
+					 */
+					tp->snd_cwnd--;
+				} else if (diff < alpha) {
+					/* We don't have enough extra packets
+					 * in the network, so speed up.
+					 */
+					tp->snd_cwnd++;
+				} else {
+					/* Sending just as fast as we
+					 * should be.
+					 */
+				}
+			}
+
+			if (tp->snd_cwnd < 2)
+				tp->snd_cwnd = 2;
+			else if (tp->snd_cwnd > tp->snd_cwnd_clamp)
+				tp->snd_cwnd = tp->snd_cwnd_clamp;
+
+			tp->snd_ssthresh = tcp_current_ssthresh(sk);
+		}
+
+		/* Wipe the slate clean for the next RTT. */
+		vegas->cntRTT = 0;
+		vegas->minRTT = 0x7fffffff;
+	}
+	/* Use normal slow start */
+	else if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+
+}
+
+/* Extract info for Tcp socket info provided via netlink. */
+void tcp_vegas_get_info(struct sock *sk, u32 ext, struct sk_buff *skb)
+{
+	const struct vegas *ca = inet_csk_ca(sk);
+	if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
+		struct tcpvegas_info info = {
+			.tcpv_enabled = ca->doing_vegas_now,
+			.tcpv_rttcnt = ca->cntRTT,
+			.tcpv_rtt = ca->baseRTT,
+			.tcpv_minrtt = ca->minRTT,
+		};
+
+		nla_put(skb, INET_DIAG_VEGASINFO, sizeof(info), &info);
+	}
+}
+EXPORT_SYMBOL_GPL(tcp_vegas_get_info);
+
+static struct tcp_congestion_ops tcp_vegas = {
+	.flags		= TCP_CONG_RTT_STAMP,
+	.init		= tcp_vegas_init,
+	.ssthresh	= tcp_reno_ssthresh,
+	.cong_avoid	= tcp_vegas_cong_avoid,
+	.min_cwnd	= tcp_reno_min_cwnd,
+	.pkts_acked	= tcp_vegas_pkts_acked,
+	.set_state	= tcp_vegas_state,
+	.cwnd_event	= tcp_vegas_cwnd_event,
+	.get_info	= tcp_vegas_get_info,
+
+	.owner		= THIS_MODULE,
+	.name		= "vegas",
+};
+
+static int __init tcp_vegas_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct vegas) > ICSK_CA_PRIV_SIZE);
+	tcp_register_congestion_control(&tcp_vegas);
+	return 0;
+}
+
+static void __exit tcp_vegas_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_vegas);
+}
+
+module_init(tcp_vegas_register);
+module_exit(tcp_vegas_unregister);
+
+MODULE_AUTHOR("Stephen Hemminger");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Vegas");
diff --git a/net/ipv4/tcp_vegas.h b/net/ipv4/tcp_vegas.h
new file mode 100644
index 0000000..6c0eea2
--- /dev/null
+++ b/net/ipv4/tcp_vegas.h
@@ -0,0 +1,24 @@
+/*
+ * TCP Vegas congestion control interface
+ */
+#ifndef __TCP_VEGAS_H
+#define __TCP_VEGAS_H 1
+
+/* Vegas variables */
+struct vegas {
+	u32	beg_snd_nxt;	/* right edge during last RTT */
+	u32	beg_snd_una;	/* left edge  during last RTT */
+	u32	beg_snd_cwnd;	/* saves the size of the cwnd */
+	u8	doing_vegas_now;/* if true, do vegas for this RTT */
+	u16	cntRTT;		/* # of RTTs measured within last RTT */
+	u32	minRTT;		/* min of RTTs measured within last RTT (in usec) */
+	u32	baseRTT;	/* the min of all Vegas RTT measurements seen (in usec) */
+};
+
+extern void tcp_vegas_init(struct sock *sk);
+extern void tcp_vegas_state(struct sock *sk, u8 ca_state);
+extern void tcp_vegas_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us);
+extern void tcp_vegas_cwnd_event(struct sock *sk, enum tcp_ca_event event);
+extern void tcp_vegas_get_info(struct sock *sk, u32 ext, struct sk_buff *skb);
+
+#endif	/* __TCP_VEGAS_H */
diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
new file mode 100644
index 0000000..d08b2e8
--- /dev/null
+++ b/net/ipv4/tcp_veno.c
@@ -0,0 +1,240 @@
+/*
+ * TCP Veno congestion control
+ *
+ * This is based on the congestion detection/avoidance scheme described in
+ *    C. P. Fu, S. C. Liew.
+ *    "TCP Veno: TCP Enhancement for Transmission over Wireless Access Networks."
+ *    IEEE Journal on Selected Areas in Communication,
+ *    Feb. 2003.
+ * 	See http://www.ntu.edu.sg/home5/ZHOU0022/papers/CPFu03a.pdf
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+
+#include <net/tcp.h>
+
+/* Default values of the Veno variables, in fixed-point representation
+ * with V_PARAM_SHIFT bits to the right of the binary point.
+ */
+#define V_PARAM_SHIFT 1
+static const int beta = 3 << V_PARAM_SHIFT;
+
+/* Veno variables */
+struct veno {
+	u8 doing_veno_now;	/* if true, do veno for this rtt */
+	u16 cntrtt;		/* # of rtts measured within last rtt */
+	u32 minrtt;		/* min of rtts measured within last rtt (in usec) */
+	u32 basertt;		/* the min of all Veno rtt measurements seen (in usec) */
+	u32 inc;		/* decide whether to increase cwnd */
+	u32 diff;		/* calculate the diff rate */
+};
+
+/* There are several situations when we must "re-start" Veno:
+ *
+ *  o when a connection is established
+ *  o after an RTO
+ *  o after fast recovery
+ *  o when we send a packet and there is no outstanding
+ *    unacknowledged data (restarting an idle connection)
+ *
+ */
+static inline void veno_enable(struct sock *sk)
+{
+	struct veno *veno = inet_csk_ca(sk);
+
+	/* turn on Veno */
+	veno->doing_veno_now = 1;
+
+	veno->minrtt = 0x7fffffff;
+}
+
+static inline void veno_disable(struct sock *sk)
+{
+	struct veno *veno = inet_csk_ca(sk);
+
+	/* turn off Veno */
+	veno->doing_veno_now = 0;
+}
+
+static void tcp_veno_init(struct sock *sk)
+{
+	struct veno *veno = inet_csk_ca(sk);
+
+	veno->basertt = 0x7fffffff;
+	veno->inc = 1;
+	veno_enable(sk);
+}
+
+/* Do rtt sampling needed for Veno. */
+static void tcp_veno_pkts_acked(struct sock *sk, u32 cnt, s32 rtt_us)
+{
+	struct veno *veno = inet_csk_ca(sk);
+	u32 vrtt;
+
+	if (rtt_us < 0)
+		return;
+
+	/* Never allow zero rtt or baseRTT */
+	vrtt = rtt_us + 1;
+
+	/* Filter to find propagation delay: */
+	if (vrtt < veno->basertt)
+		veno->basertt = vrtt;
+
+	/* Find the min rtt during the last rtt to find
+	 * the current prop. delay + queuing delay:
+	 */
+	veno->minrtt = min(veno->minrtt, vrtt);
+	veno->cntrtt++;
+}
+
+static void tcp_veno_state(struct sock *sk, u8 ca_state)
+{
+	if (ca_state == TCP_CA_Open)
+		veno_enable(sk);
+	else
+		veno_disable(sk);
+}
+
+/*
+ * If the connection is idle and we are restarting,
+ * then we don't want to do any Veno calculations
+ * until we get fresh rtt samples.  So when we
+ * restart, we reset our Veno state to a clean
+ * state. After we get acks for this flight of
+ * packets, _then_ we can make Veno calculations
+ * again.
+ */
+static void tcp_veno_cwnd_event(struct sock *sk, enum tcp_ca_event event)
+{
+	if (event == CA_EVENT_CWND_RESTART || event == CA_EVENT_TX_START)
+		tcp_veno_init(sk);
+}
+
+static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct veno *veno = inet_csk_ca(sk);
+
+	if (!veno->doing_veno_now) {
+		tcp_reno_cong_avoid(sk, ack, in_flight);
+		return;
+	}
+
+	/* limited by applications */
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	/* We do the Veno calculations only if we got enough rtt samples */
+	if (veno->cntrtt <= 2) {
+		/* We don't have enough rtt samples to do the Veno
+		 * calculation, so we'll behave like Reno.
+		 */
+		tcp_reno_cong_avoid(sk, ack, in_flight);
+	} else {
+		u64 target_cwnd;
+		u32 rtt;
+
+		/* We have enough rtt samples, so, using the Veno
+		 * algorithm, we determine the state of the network.
+		 */
+
+		rtt = veno->minrtt;
+
+		target_cwnd = (tp->snd_cwnd * veno->basertt);
+		target_cwnd <<= V_PARAM_SHIFT;
+		do_div(target_cwnd, rtt);
+
+		veno->diff = (tp->snd_cwnd << V_PARAM_SHIFT) - target_cwnd;
+
+		if (tp->snd_cwnd <= tp->snd_ssthresh) {
+			/* Slow start.  */
+			tcp_slow_start(tp);
+		} else {
+			/* Congestion avoidance. */
+			if (veno->diff < beta) {
+				/* In the "non-congestive state", increase cwnd
+				 *  every rtt.
+				 */
+				if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+					if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+						tp->snd_cwnd++;
+					tp->snd_cwnd_cnt = 0;
+				} else
+					tp->snd_cwnd_cnt++;
+			} else {
+				/* In the "congestive state", increase cwnd
+				 * every other rtt.
+				 */
+				if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+					if (veno->inc
+					    && tp->snd_cwnd <
+					    tp->snd_cwnd_clamp) {
+						tp->snd_cwnd++;
+						veno->inc = 0;
+					} else
+						veno->inc = 1;
+					tp->snd_cwnd_cnt = 0;
+				} else
+					tp->snd_cwnd_cnt++;
+			}
+
+		}
+		if (tp->snd_cwnd < 2)
+			tp->snd_cwnd = 2;
+		else if (tp->snd_cwnd > tp->snd_cwnd_clamp)
+			tp->snd_cwnd = tp->snd_cwnd_clamp;
+	}
+	/* Wipe the slate clean for the next rtt. */
+	/* veno->cntrtt = 0; */
+	veno->minrtt = 0x7fffffff;
+}
+
+/* Veno MD phase */
+static u32 tcp_veno_ssthresh(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct veno *veno = inet_csk_ca(sk);
+
+	if (veno->diff < beta)
+		/* in "non-congestive state", cut cwnd by 1/5 */
+		return max(tp->snd_cwnd * 4 / 5, 2U);
+	else
+		/* in "congestive state", cut cwnd by 1/2 */
+		return max(tp->snd_cwnd >> 1U, 2U);
+}
+
+static struct tcp_congestion_ops tcp_veno = {
+	.flags		= TCP_CONG_RTT_STAMP,
+	.init		= tcp_veno_init,
+	.ssthresh	= tcp_veno_ssthresh,
+	.cong_avoid	= tcp_veno_cong_avoid,
+	.pkts_acked	= tcp_veno_pkts_acked,
+	.set_state	= tcp_veno_state,
+	.cwnd_event	= tcp_veno_cwnd_event,
+
+	.owner		= THIS_MODULE,
+	.name		= "veno",
+};
+
+static int __init tcp_veno_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct veno) > ICSK_CA_PRIV_SIZE);
+	tcp_register_congestion_control(&tcp_veno);
+	return 0;
+}
+
+static void __exit tcp_veno_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_veno);
+}
+
+module_init(tcp_veno_register);
+module_exit(tcp_veno_unregister);
+
+MODULE_AUTHOR("Bin Zhou, Cheng Peng Fu");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Veno");
diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c
new file mode 100644
index 0000000..20151d6
--- /dev/null
+++ b/net/ipv4/tcp_westwood.c
@@ -0,0 +1,304 @@
+/*
+ * TCP Westwood+: end-to-end bandwidth estimation for TCP
+ *
+ *      Angelo Dell'Aera: author of the first version of TCP Westwood+ in Linux 2.4
+ *
+ * Support at http://c3lab.poliba.it/index.php/Westwood
+ * Main references in literature:
+ *
+ * - Mascolo S, Casetti, M. Gerla et al.
+ *   "TCP Westwood: bandwidth estimation for TCP" Proc. ACM Mobicom 2001
+ *
+ * - A. Grieco, s. Mascolo
+ *   "Performance evaluation of New Reno, Vegas, Westwood+ TCP" ACM Computer
+ *     Comm. Review, 2004
+ *
+ * - A. Dell'Aera, L. Grieco, S. Mascolo.
+ *   "Linux 2.4 Implementation of Westwood+ TCP with Rate-Halving :
+ *    A Performance Evaluation Over the Internet" (ICC 2004), Paris, June 2004
+ *
+ * Westwood+ employs end-to-end bandwidth measurement to set cwnd and
+ * ssthresh after packet loss. The probing phase is as the original Reno.
+ */
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+#include <net/tcp.h>
+
+/* TCP Westwood structure */
+struct westwood {
+	u32    bw_ns_est;        /* first bandwidth estimation..not too smoothed 8) */
+	u32    bw_est;           /* bandwidth estimate */
+	u32    rtt_win_sx;       /* here starts a new evaluation... */
+	u32    bk;
+	u32    snd_una;          /* used for evaluating the number of acked bytes */
+	u32    cumul_ack;
+	u32    accounted;
+	u32    rtt;
+	u32    rtt_min;          /* minimum observed RTT */
+	u8     first_ack;        /* flag which infers that this is the first ack */
+	u8     reset_rtt_min;    /* Reset RTT min to next RTT sample*/
+};
+
+
+/* TCP Westwood functions and constants */
+#define TCP_WESTWOOD_RTT_MIN   (HZ/20)	/* 50ms */
+#define TCP_WESTWOOD_INIT_RTT  (20*HZ)	/* maybe too conservative?! */
+
+/*
+ * @tcp_westwood_create
+ * This function initializes fields used in TCP Westwood+,
+ * it is called after the initial SYN, so the sequence numbers
+ * are correct but new passive connections we have no
+ * information about RTTmin at this time so we simply set it to
+ * TCP_WESTWOOD_INIT_RTT. This value was chosen to be too conservative
+ * since in this way we're sure it will be updated in a consistent
+ * way as soon as possible. It will reasonably happen within the first
+ * RTT period of the connection lifetime.
+ */
+static void tcp_westwood_init(struct sock *sk)
+{
+	struct westwood *w = inet_csk_ca(sk);
+
+	w->bk = 0;
+	w->bw_ns_est = 0;
+	w->bw_est = 0;
+	w->accounted = 0;
+	w->cumul_ack = 0;
+	w->reset_rtt_min = 1;
+	w->rtt_min = w->rtt = TCP_WESTWOOD_INIT_RTT;
+	w->rtt_win_sx = tcp_time_stamp;
+	w->snd_una = tcp_sk(sk)->snd_una;
+	w->first_ack = 1;
+}
+
+/*
+ * @westwood_do_filter
+ * Low-pass filter. Implemented using constant coefficients.
+ */
+static inline u32 westwood_do_filter(u32 a, u32 b)
+{
+	return (((7 * a) + b) >> 3);
+}
+
+static void westwood_filter(struct westwood *w, u32 delta)
+{
+	/* If the filter is empty fill it with the first sample of bandwidth  */
+	if (w->bw_ns_est == 0 && w->bw_est == 0) {
+		w->bw_ns_est = w->bk / delta;
+		w->bw_est = w->bw_ns_est;
+	} else {
+		w->bw_ns_est = westwood_do_filter(w->bw_ns_est, w->bk / delta);
+		w->bw_est = westwood_do_filter(w->bw_est, w->bw_ns_est);
+	}
+}
+
+/*
+ * @westwood_pkts_acked
+ * Called after processing group of packets.
+ * but all westwood needs is the last sample of srtt.
+ */
+static void tcp_westwood_pkts_acked(struct sock *sk, u32 cnt, s32 rtt)
+{
+	struct westwood *w = inet_csk_ca(sk);
+
+	if (rtt > 0)
+		w->rtt = usecs_to_jiffies(rtt);
+}
+
+/*
+ * @westwood_update_window
+ * It updates RTT evaluation window if it is the right moment to do
+ * it. If so it calls filter for evaluating bandwidth.
+ */
+static void westwood_update_window(struct sock *sk)
+{
+	struct westwood *w = inet_csk_ca(sk);
+	s32 delta = tcp_time_stamp - w->rtt_win_sx;
+
+	/* Initialize w->snd_una with the first acked sequence number in order
+	 * to fix mismatch between tp->snd_una and w->snd_una for the first
+	 * bandwidth sample
+	 */
+	if (w->first_ack) {
+		w->snd_una = tcp_sk(sk)->snd_una;
+		w->first_ack = 0;
+	}
+
+	/*
+	 * See if a RTT-window has passed.
+	 * Be careful since if RTT is less than
+	 * 50ms we don't filter but we continue 'building the sample'.
+	 * This minimum limit was chosen since an estimation on small
+	 * time intervals is better to avoid...
+	 * Obviously on a LAN we reasonably will always have
+	 * right_bound = left_bound + WESTWOOD_RTT_MIN
+	 */
+	if (w->rtt && delta > max_t(u32, w->rtt, TCP_WESTWOOD_RTT_MIN)) {
+		westwood_filter(w, delta);
+
+		w->bk = 0;
+		w->rtt_win_sx = tcp_time_stamp;
+	}
+}
+
+static inline void update_rtt_min(struct westwood *w)
+{
+	if (w->reset_rtt_min) {
+		w->rtt_min = w->rtt;
+		w->reset_rtt_min = 0;
+	} else
+		w->rtt_min = min(w->rtt, w->rtt_min);
+}
+
+
+/*
+ * @westwood_fast_bw
+ * It is called when we are in fast path. In particular it is called when
+ * header prediction is successful. In such case in fact update is
+ * straight forward and doesn't need any particular care.
+ */
+static inline void westwood_fast_bw(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct westwood *w = inet_csk_ca(sk);
+
+	westwood_update_window(sk);
+
+	w->bk += tp->snd_una - w->snd_una;
+	w->snd_una = tp->snd_una;
+	update_rtt_min(w);
+}
+
+/*
+ * @westwood_acked_count
+ * This function evaluates cumul_ack for evaluating bk in case of
+ * delayed or partial acks.
+ */
+static inline u32 westwood_acked_count(struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct westwood *w = inet_csk_ca(sk);
+
+	w->cumul_ack = tp->snd_una - w->snd_una;
+
+	/* If cumul_ack is 0 this is a dupack since it's not moving
+	 * tp->snd_una.
+	 */
+	if (!w->cumul_ack) {
+		w->accounted += tp->mss_cache;
+		w->cumul_ack = tp->mss_cache;
+	}
+
+	if (w->cumul_ack > tp->mss_cache) {
+		/* Partial or delayed ack */
+		if (w->accounted >= w->cumul_ack) {
+			w->accounted -= w->cumul_ack;
+			w->cumul_ack = tp->mss_cache;
+		} else {
+			w->cumul_ack -= w->accounted;
+			w->accounted = 0;
+		}
+	}
+
+	w->snd_una = tp->snd_una;
+
+	return w->cumul_ack;
+}
+
+
+/*
+ * TCP Westwood
+ * Here limit is evaluated as Bw estimation*RTTmin (for obtaining it
+ * in packets we use mss_cache). Rttmin is guaranteed to be >= 2
+ * so avoids ever returning 0.
+ */
+static u32 tcp_westwood_bw_rttmin(const struct sock *sk)
+{
+	const struct tcp_sock *tp = tcp_sk(sk);
+	const struct westwood *w = inet_csk_ca(sk);
+	return max_t(u32, (w->bw_est * w->rtt_min) / tp->mss_cache, 2);
+}
+
+static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct westwood *w = inet_csk_ca(sk);
+
+	switch (event) {
+	case CA_EVENT_FAST_ACK:
+		westwood_fast_bw(sk);
+		break;
+
+	case CA_EVENT_COMPLETE_CWR:
+		tp->snd_cwnd = tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk);
+		break;
+
+	case CA_EVENT_FRTO:
+		tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk);
+		/* Update RTT_min when next ack arrives */
+		w->reset_rtt_min = 1;
+		break;
+
+	case CA_EVENT_SLOW_ACK:
+		westwood_update_window(sk);
+		w->bk += westwood_acked_count(sk);
+		update_rtt_min(w);
+		break;
+
+	default:
+		/* don't care */
+		break;
+	}
+}
+
+
+/* Extract info for Tcp socket info provided via netlink. */
+static void tcp_westwood_info(struct sock *sk, u32 ext,
+			      struct sk_buff *skb)
+{
+	const struct westwood *ca = inet_csk_ca(sk);
+	if (ext & (1 << (INET_DIAG_VEGASINFO - 1))) {
+		struct tcpvegas_info info = {
+			.tcpv_enabled = 1,
+			.tcpv_rtt = jiffies_to_usecs(ca->rtt),
+			.tcpv_minrtt = jiffies_to_usecs(ca->rtt_min),
+		};
+
+		nla_put(skb, INET_DIAG_VEGASINFO, sizeof(info), &info);
+	}
+}
+
+
+static struct tcp_congestion_ops tcp_westwood = {
+	.init		= tcp_westwood_init,
+	.ssthresh	= tcp_reno_ssthresh,
+	.cong_avoid	= tcp_reno_cong_avoid,
+	.min_cwnd	= tcp_westwood_bw_rttmin,
+	.cwnd_event	= tcp_westwood_event,
+	.get_info	= tcp_westwood_info,
+	.pkts_acked	= tcp_westwood_pkts_acked,
+
+	.owner		= THIS_MODULE,
+	.name		= "westwood"
+};
+
+static int __init tcp_westwood_register(void)
+{
+	BUILD_BUG_ON(sizeof(struct westwood) > ICSK_CA_PRIV_SIZE);
+	return tcp_register_congestion_control(&tcp_westwood);
+}
+
+static void __exit tcp_westwood_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_westwood);
+}
+
+module_init(tcp_westwood_register);
+module_exit(tcp_westwood_unregister);
+
+MODULE_AUTHOR("Stephen Hemminger, Angelo Dell'Aera");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TCP Westwood+");
diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c
new file mode 100644
index 0000000..e03b101
--- /dev/null
+++ b/net/ipv4/tcp_yeah.c
@@ -0,0 +1,267 @@
+/*
+ *
+ *   YeAH TCP
+ *
+ * For further details look at:
+ *    http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
+ *
+ */
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/inet_diag.h>
+
+#include <net/tcp.h>
+
+#include "tcp_vegas.h"
+
+#define TCP_YEAH_ALPHA       80 //lin number of packets queued at the bottleneck
+#define TCP_YEAH_GAMMA        1 //lin fraction of queue to be removed per rtt
+#define TCP_YEAH_DELTA        3 //log minimum fraction of cwnd to be removed on loss
+#define TCP_YEAH_EPSILON      1 //log maximum fraction to be removed on early decongestion
+#define TCP_YEAH_PHY          8 //lin maximum delta from base
+#define TCP_YEAH_RHO         16 //lin minumum number of consecutive rtt to consider competition on loss
+#define TCP_YEAH_ZETA        50 //lin minimum number of state switchs to reset reno_count
+
+#define TCP_SCALABLE_AI_CNT	 100U
+
+/* YeAH variables */
+struct yeah {
+	struct vegas vegas;	/* must be first */
+
+	/* YeAH */
+	u32 lastQ;
+	u32 doing_reno_now;
+
+	u32 reno_count;
+	u32 fast_count;
+
+	u32 pkts_acked;
+};
+
+static void tcp_yeah_init(struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+
+	tcp_vegas_init(sk);
+
+	yeah->doing_reno_now = 0;
+	yeah->lastQ = 0;
+
+	yeah->reno_count = 2;
+
+	/* Ensure the MD arithmetic works.  This is somewhat pedantic,
+	 * since I don't think we will see a cwnd this large. :) */
+	tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
+
+}
+
+
+static void tcp_yeah_pkts_acked(struct sock *sk, u32 pkts_acked, s32 rtt_us)
+{
+	const struct inet_connection_sock *icsk = inet_csk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+
+	if (icsk->icsk_ca_state == TCP_CA_Open)
+		yeah->pkts_acked = pkts_acked;
+
+	tcp_vegas_pkts_acked(sk, pkts_acked, rtt_us);
+}
+
+static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+
+	if (!tcp_is_cwnd_limited(sk, in_flight))
+		return;
+
+	if (tp->snd_cwnd <= tp->snd_ssthresh)
+		tcp_slow_start(tp);
+
+	else if (!yeah->doing_reno_now) {
+		/* Scalable */
+
+		tp->snd_cwnd_cnt+=yeah->pkts_acked;
+		if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
+			if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+				tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+		}
+
+		yeah->pkts_acked = 1;
+
+	} else {
+		/* Reno */
+
+		if (tp->snd_cwnd_cnt < tp->snd_cwnd)
+			tp->snd_cwnd_cnt++;
+
+		if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+			tp->snd_cwnd++;
+			tp->snd_cwnd_cnt = 0;
+		}
+	}
+
+	/* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.
+	 *
+	 * These are so named because they represent the approximate values
+	 * of snd_una and snd_nxt at the beginning of the current RTT. More
+	 * precisely, they represent the amount of data sent during the RTT.
+	 * At the end of the RTT, when we receive an ACK for v_beg_snd_nxt,
+	 * we will calculate that (v_beg_snd_nxt - v_vegas.beg_snd_una) outstanding
+	 * bytes of data have been ACKed during the course of the RTT, giving
+	 * an "actual" rate of:
+	 *
+	 *     (v_beg_snd_nxt - v_vegas.beg_snd_una) / (rtt duration)
+	 *
+	 * Unfortunately, v_vegas.beg_snd_una is not exactly equal to snd_una,
+	 * because delayed ACKs can cover more than one segment, so they
+	 * don't line up yeahly with the boundaries of RTTs.
+	 *
+	 * Another unfortunate fact of life is that delayed ACKs delay the
+	 * advance of the left edge of our send window, so that the number
+	 * of bytes we send in an RTT is often less than our cwnd will allow.
+	 * So we keep track of our cwnd separately, in v_beg_snd_cwnd.
+	 */
+
+	if (after(ack, yeah->vegas.beg_snd_nxt)) {
+
+		/* We do the Vegas calculations only if we got enough RTT
+		 * samples that we can be reasonably sure that we got
+		 * at least one RTT sample that wasn't from a delayed ACK.
+		 * If we only had 2 samples total,
+		 * then that means we're getting only 1 ACK per RTT, which
+		 * means they're almost certainly delayed ACKs.
+		 * If  we have 3 samples, we should be OK.
+		 */
+
+		if (yeah->vegas.cntRTT > 2) {
+			u32 rtt, queue;
+			u64 bw;
+
+			/* We have enough RTT samples, so, using the Vegas
+			 * algorithm, we determine if we should increase or
+			 * decrease cwnd, and by how much.
+			 */
+
+			/* Pluck out the RTT we are using for the Vegas
+			 * calculations. This is the min RTT seen during the
+			 * last RTT. Taking the min filters out the effects
+			 * of delayed ACKs, at the cost of noticing congestion
+			 * a bit later.
+			 */
+			rtt = yeah->vegas.minRTT;
+
+			/* Compute excess number of packets above bandwidth
+			 * Avoid doing full 64 bit divide.
+			 */
+			bw = tp->snd_cwnd;
+			bw *= rtt - yeah->vegas.baseRTT;
+			do_div(bw, rtt);
+			queue = bw;
+
+			if (queue > TCP_YEAH_ALPHA ||
+			    rtt - yeah->vegas.baseRTT > (yeah->vegas.baseRTT / TCP_YEAH_PHY)) {
+				if (queue > TCP_YEAH_ALPHA
+				    && tp->snd_cwnd > yeah->reno_count) {
+					u32 reduction = min(queue / TCP_YEAH_GAMMA ,
+							    tp->snd_cwnd >> TCP_YEAH_EPSILON);
+
+					tp->snd_cwnd -= reduction;
+
+					tp->snd_cwnd = max(tp->snd_cwnd,
+							   yeah->reno_count);
+
+					tp->snd_ssthresh = tp->snd_cwnd;
+				}
+
+				if (yeah->reno_count <= 2)
+					yeah->reno_count = max(tp->snd_cwnd>>1, 2U);
+				else
+					yeah->reno_count++;
+
+				yeah->doing_reno_now = min(yeah->doing_reno_now + 1,
+							   0xffffffU);
+			} else {
+				yeah->fast_count++;
+
+				if (yeah->fast_count > TCP_YEAH_ZETA) {
+					yeah->reno_count = 2;
+					yeah->fast_count = 0;
+				}
+
+				yeah->doing_reno_now = 0;
+			}
+
+			yeah->lastQ = queue;
+
+		}
+
+		/* Save the extent of the current window so we can use this
+		 * at the end of the next RTT.
+		 */
+		yeah->vegas.beg_snd_una  = yeah->vegas.beg_snd_nxt;
+		yeah->vegas.beg_snd_nxt  = tp->snd_nxt;
+		yeah->vegas.beg_snd_cwnd = tp->snd_cwnd;
+
+		/* Wipe the slate clean for the next RTT. */
+		yeah->vegas.cntRTT = 0;
+		yeah->vegas.minRTT = 0x7fffffff;
+	}
+}
+
+static u32 tcp_yeah_ssthresh(struct sock *sk) {
+	const struct tcp_sock *tp = tcp_sk(sk);
+	struct yeah *yeah = inet_csk_ca(sk);
+	u32 reduction;
+
+	if (yeah->doing_reno_now < TCP_YEAH_RHO) {
+		reduction = yeah->lastQ;
+
+		reduction = min( reduction, max(tp->snd_cwnd>>1, 2U) );
+
+		reduction = max( reduction, tp->snd_cwnd >> TCP_YEAH_DELTA);
+	} else
+		reduction = max(tp->snd_cwnd>>1,2U);
+
+	yeah->fast_count = 0;
+	yeah->reno_count = max(yeah->reno_count>>1, 2U);
+
+	return tp->snd_cwnd - reduction;
+}
+
+static struct tcp_congestion_ops tcp_yeah = {
+	.flags		= TCP_CONG_RTT_STAMP,
+	.init		= tcp_yeah_init,
+	.ssthresh	= tcp_yeah_ssthresh,
+	.cong_avoid	= tcp_yeah_cong_avoid,
+	.min_cwnd	= tcp_reno_min_cwnd,
+	.set_state	= tcp_vegas_state,
+	.cwnd_event	= tcp_vegas_cwnd_event,
+	.get_info	= tcp_vegas_get_info,
+	.pkts_acked	= tcp_yeah_pkts_acked,
+
+	.owner		= THIS_MODULE,
+	.name		= "yeah",
+};
+
+static int __init tcp_yeah_register(void)
+{
+	BUG_ON(sizeof(struct yeah) > ICSK_CA_PRIV_SIZE);
+	tcp_register_congestion_control(&tcp_yeah);
+	return 0;
+}
+
+static void __exit tcp_yeah_unregister(void)
+{
+	tcp_unregister_congestion_control(&tcp_yeah);
+}
+
+module_init(tcp_yeah_register);
+module_exit(tcp_yeah_unregister);
+
+MODULE_AUTHOR("Angelo P. Castellani");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("YeAH TCP");
diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c
new file mode 100644
index 0000000..cb1f0e8
--- /dev/null
+++ b/net/ipv4/tunnel4.c
@@ -0,0 +1,179 @@
+/* tunnel4.c: Generic IP tunnel transformer.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/icmp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/xfrm.h>
+
+static struct xfrm_tunnel *tunnel4_handlers;
+static struct xfrm_tunnel *tunnel64_handlers;
+static DEFINE_MUTEX(tunnel4_mutex);
+
+static inline struct xfrm_tunnel **fam_handlers(unsigned short family)
+{
+	return (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers;
+}
+
+int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family)
+{
+	struct xfrm_tunnel **pprev;
+	int ret = -EEXIST;
+	int priority = handler->priority;
+
+	mutex_lock(&tunnel4_mutex);
+
+	for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
+		if ((*pprev)->priority > priority)
+			break;
+		if ((*pprev)->priority == priority)
+			goto err;
+	}
+
+	handler->next = *pprev;
+	*pprev = handler;
+
+	ret = 0;
+
+err:
+	mutex_unlock(&tunnel4_mutex);
+
+	return ret;
+}
+
+EXPORT_SYMBOL(xfrm4_tunnel_register);
+
+int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family)
+{
+	struct xfrm_tunnel **pprev;
+	int ret = -ENOENT;
+
+	mutex_lock(&tunnel4_mutex);
+
+	for (pprev = fam_handlers(family); *pprev; pprev = &(*pprev)->next) {
+		if (*pprev == handler) {
+			*pprev = handler->next;
+			ret = 0;
+			break;
+		}
+	}
+
+	mutex_unlock(&tunnel4_mutex);
+
+	synchronize_net();
+
+	return ret;
+}
+
+EXPORT_SYMBOL(xfrm4_tunnel_deregister);
+
+static int tunnel4_rcv(struct sk_buff *skb)
+{
+	struct xfrm_tunnel *handler;
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto drop;
+
+	for (handler = tunnel4_handlers; handler; handler = handler->next)
+		if (!handler->handler(skb))
+			return 0;
+
+	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static int tunnel64_rcv(struct sk_buff *skb)
+{
+	struct xfrm_tunnel *handler;
+
+	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+		goto drop;
+
+	for (handler = tunnel64_handlers; handler; handler = handler->next)
+		if (!handler->handler(skb))
+			return 0;
+
+	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+#endif
+
+static void tunnel4_err(struct sk_buff *skb, u32 info)
+{
+	struct xfrm_tunnel *handler;
+
+	for (handler = tunnel4_handlers; handler; handler = handler->next)
+		if (!handler->err_handler(skb, info))
+			break;
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static void tunnel64_err(struct sk_buff *skb, u32 info)
+{
+	struct xfrm_tunnel *handler;
+
+	for (handler = tunnel64_handlers; handler; handler = handler->next)
+		if (!handler->err_handler(skb, info))
+			break;
+}
+#endif
+
+static struct net_protocol tunnel4_protocol = {
+	.handler	=	tunnel4_rcv,
+	.err_handler	=	tunnel4_err,
+	.no_policy	=	1,
+	.netns_ok	=	1,
+};
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static struct net_protocol tunnel64_protocol = {
+	.handler	=	tunnel64_rcv,
+	.err_handler	=	tunnel64_err,
+	.no_policy	=	1,
+	.netns_ok	=	1,
+};
+#endif
+
+static int __init tunnel4_init(void)
+{
+	if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
+		printk(KERN_ERR "tunnel4 init: can't add protocol\n");
+		return -EAGAIN;
+	}
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
+		printk(KERN_ERR "tunnel64 init: can't add protocol\n");
+		inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
+		return -EAGAIN;
+	}
+#endif
+	return 0;
+}
+
+static void __exit tunnel4_fini(void)
+{
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
+		printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
+#endif
+	if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
+		printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
+}
+
+module_init(tunnel4_init);
+module_exit(tunnel4_fini);
+MODULE_LICENSE("GPL");
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
new file mode 100644
index 0000000..77b344b
--- /dev/null
+++ b/net/ipv4/udp.c
@@ -0,0 +1,1734 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The User Datagram Protocol (UDP).
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Alan Cox, <alan@lxorguk.ukuu.org.uk>
+ *		Hirokazu Takahashi, <taka@valinux.co.jp>
+ *
+ * Fixes:
+ *		Alan Cox	:	verify_area() calls
+ *		Alan Cox	: 	stopped close while in use off icmp
+ *					messages. Not a fix but a botch that
+ *					for udp at least is 'valid'.
+ *		Alan Cox	:	Fixed icmp handling properly
+ *		Alan Cox	: 	Correct error for oversized datagrams
+ *		Alan Cox	:	Tidied select() semantics.
+ *		Alan Cox	:	udp_err() fixed properly, also now
+ *					select and read wake correctly on errors
+ *		Alan Cox	:	udp_send verify_area moved to avoid mem leak
+ *		Alan Cox	:	UDP can count its memory
+ *		Alan Cox	:	send to an unknown connection causes
+ *					an ECONNREFUSED off the icmp, but
+ *					does NOT close.
+ *		Alan Cox	:	Switched to new sk_buff handlers. No more backlog!
+ *		Alan Cox	:	Using generic datagram code. Even smaller and the PEEK
+ *					bug no longer crashes it.
+ *		Fred Van Kempen	: 	Net2e support for sk->broadcast.
+ *		Alan Cox	:	Uses skb_free_datagram
+ *		Alan Cox	:	Added get/set sockopt support.
+ *		Alan Cox	:	Broadcasting without option set returns EACCES.
+ *		Alan Cox	:	No wakeup calls. Instead we now use the callbacks.
+ *		Alan Cox	:	Use ip_tos and ip_ttl
+ *		Alan Cox	:	SNMP Mibs
+ *		Alan Cox	:	MSG_DONTROUTE, and 0.0.0.0 support.
+ *		Matt Dillon	:	UDP length checks.
+ *		Alan Cox	:	Smarter af_inet used properly.
+ *		Alan Cox	:	Use new kernel side addressing.
+ *		Alan Cox	:	Incorrect return on truncated datagram receive.
+ *	Arnt Gulbrandsen 	:	New udp_send and stuff
+ *		Alan Cox	:	Cache last socket
+ *		Alan Cox	:	Route cache
+ *		Jon Peatfield	:	Minor efficiency fix to sendto().
+ *		Mike Shaver	:	RFC1122 checks.
+ *		Alan Cox	:	Nonblocking error fix.
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		Mike McLagan	:	Routing by source
+ *		David S. Miller	:	New socket lookup architecture.
+ *					Last socket cache retained as it
+ *					does have a high hit rate.
+ *		Olaf Kirch	:	Don't linearise iovec on sendmsg.
+ *		Andi Kleen	:	Some cleanups, cache destination entry
+ *					for connect.
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
+ *		Melvin Smith	:	Check msg_name not msg_namelen in sendto(),
+ *					return ENOTCONN for unconnected sockets (POSIX)
+ *		Janos Farkas	:	don't deliver multi/broadcasts to a different
+ *					bound-to-device socket
+ *	Hirokazu Takahashi	:	HW checksumming for outgoing UDP
+ *					datagrams.
+ *	Hirokazu Takahashi	:	sendfile() on UDP works now.
+ *		Arnaldo C. Melo :	convert /proc/net/udp to seq_file
+ *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
+ *	Alexey Kuznetsov:		allow both IPv4 and IPv6 sockets to bind
+ *					a single port at the same time.
+ *	Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
+ *	James Chapman		:	Add L2TP encapsulation type.
+ *
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+#include <linux/bootmem.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/module.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/igmp.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <net/tcp_states.h>
+#include <linux/skbuff.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <net/net_namespace.h>
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+#include "udp_impl.h"
+
+/*
+ *	Snmp MIB for the UDP layer
+ */
+
+struct hlist_head udp_hash[UDP_HTABLE_SIZE];
+DEFINE_RWLOCK(udp_hash_lock);
+
+int sysctl_udp_mem[3] __read_mostly;
+int sysctl_udp_rmem_min __read_mostly;
+int sysctl_udp_wmem_min __read_mostly;
+
+EXPORT_SYMBOL(sysctl_udp_mem);
+EXPORT_SYMBOL(sysctl_udp_rmem_min);
+EXPORT_SYMBOL(sysctl_udp_wmem_min);
+
+atomic_t udp_memory_allocated;
+EXPORT_SYMBOL(udp_memory_allocated);
+
+static int udp_lib_lport_inuse(struct net *net, __u16 num,
+			       const struct hlist_head udptable[],
+			       struct sock *sk,
+			       int (*saddr_comp)(const struct sock *sk1,
+						 const struct sock *sk2))
+{
+	struct sock *sk2;
+	struct hlist_node *node;
+
+	sk_for_each(sk2, node, &udptable[udp_hashfn(net, num)])
+		if (net_eq(sock_net(sk2), net)			&&
+		    sk2 != sk					&&
+		    sk2->sk_hash == num				&&
+		    (!sk2->sk_reuse || !sk->sk_reuse)		&&
+		    (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
+			|| sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+		    (*saddr_comp)(sk, sk2))
+			return 1;
+	return 0;
+}
+
+/**
+ *  udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
+ *
+ *  @sk:          socket struct in question
+ *  @snum:        port number to look up
+ *  @saddr_comp:  AF-dependent comparison of bound local IP addresses
+ */
+int udp_lib_get_port(struct sock *sk, unsigned short snum,
+		       int (*saddr_comp)(const struct sock *sk1,
+					 const struct sock *sk2 )    )
+{
+	struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
+	int    error = 1;
+	struct net *net = sock_net(sk);
+
+	write_lock_bh(&udp_hash_lock);
+
+	if (!snum) {
+		int low, high, remaining;
+		unsigned rand;
+		unsigned short first;
+
+		inet_get_local_port_range(&low, &high);
+		remaining = (high - low) + 1;
+
+		rand = net_random();
+		snum = first = rand % remaining + low;
+		rand |= 1;
+		while (udp_lib_lport_inuse(net, snum, udptable, sk,
+					   saddr_comp)) {
+			do {
+				snum = snum + rand;
+			} while (snum < low || snum > high);
+			if (snum == first)
+				goto fail;
+		}
+	} else if (udp_lib_lport_inuse(net, snum, udptable, sk, saddr_comp))
+		goto fail;
+
+	inet_sk(sk)->num = snum;
+	sk->sk_hash = snum;
+	if (sk_unhashed(sk)) {
+		sk_add_node(sk, &udptable[udp_hashfn(net, snum)]);
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+	}
+	error = 0;
+fail:
+	write_unlock_bh(&udp_hash_lock);
+	return error;
+}
+
+static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
+{
+	struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);
+
+	return 	( !ipv6_only_sock(sk2)  &&
+		  (!inet1->rcv_saddr || !inet2->rcv_saddr ||
+		   inet1->rcv_saddr == inet2->rcv_saddr      ));
+}
+
+int udp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+	return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
+}
+
+/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
+ * harder than this. -DaveM
+ */
+static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
+		__be16 sport, __be32 daddr, __be16 dport,
+		int dif, struct hlist_head udptable[])
+{
+	struct sock *sk, *result = NULL;
+	struct hlist_node *node;
+	unsigned short hnum = ntohs(dport);
+	int badness = -1;
+
+	read_lock(&udp_hash_lock);
+	sk_for_each(sk, node, &udptable[udp_hashfn(net, hnum)]) {
+		struct inet_sock *inet = inet_sk(sk);
+
+		if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
+				!ipv6_only_sock(sk)) {
+			int score = (sk->sk_family == PF_INET ? 1 : 0);
+			if (inet->rcv_saddr) {
+				if (inet->rcv_saddr != daddr)
+					continue;
+				score+=2;
+			}
+			if (inet->daddr) {
+				if (inet->daddr != saddr)
+					continue;
+				score+=2;
+			}
+			if (inet->dport) {
+				if (inet->dport != sport)
+					continue;
+				score+=2;
+			}
+			if (sk->sk_bound_dev_if) {
+				if (sk->sk_bound_dev_if != dif)
+					continue;
+				score+=2;
+			}
+			if (score == 9) {
+				result = sk;
+				break;
+			} else if (score > badness) {
+				result = sk;
+				badness = score;
+			}
+		}
+	}
+	if (result)
+		sock_hold(result);
+	read_unlock(&udp_hash_lock);
+	return result;
+}
+
+static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+						 __be16 sport, __be16 dport,
+						 struct hlist_head udptable[])
+{
+	struct sock *sk;
+	const struct iphdr *iph = ip_hdr(skb);
+
+	if (unlikely(sk = skb_steal_sock(skb)))
+		return sk;
+	else
+		return __udp4_lib_lookup(dev_net(skb->dst->dev), iph->saddr, sport,
+					 iph->daddr, dport, inet_iif(skb),
+					 udptable);
+}
+
+struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+			     __be32 daddr, __be16 dport, int dif)
+{
+	return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, udp_hash);
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+
+static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
+					     __be16 loc_port, __be32 loc_addr,
+					     __be16 rmt_port, __be32 rmt_addr,
+					     int dif)
+{
+	struct hlist_node *node;
+	struct sock *s = sk;
+	unsigned short hnum = ntohs(loc_port);
+
+	sk_for_each_from(s, node) {
+		struct inet_sock *inet = inet_sk(s);
+
+		if (!net_eq(sock_net(s), net)				||
+		    s->sk_hash != hnum					||
+		    (inet->daddr && inet->daddr != rmt_addr)		||
+		    (inet->dport != rmt_port && inet->dport)		||
+		    (inet->rcv_saddr && inet->rcv_saddr != loc_addr)	||
+		    ipv6_only_sock(s)					||
+		    (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
+			continue;
+		if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
+			continue;
+		goto found;
+	}
+	s = NULL;
+found:
+	return s;
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.  If err < 0 then the socket should
+ * be closed and the error returned to the user.  If err > 0
+ * it's just the icmp type << 8 | icmp code.
+ * Header points to the ip header of the error packet. We move
+ * on past this. Then (as it used to claim before adjustment)
+ * header points to the first 8 bytes of the udp header.  We need
+ * to find the appropriate port.
+ */
+
+void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
+{
+	struct inet_sock *inet;
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
+	const int type = icmp_hdr(skb)->type;
+	const int code = icmp_hdr(skb)->code;
+	struct sock *sk;
+	int harderr;
+	int err;
+	struct net *net = dev_net(skb->dev);
+
+	sk = __udp4_lib_lookup(net, iph->daddr, uh->dest,
+			iph->saddr, uh->source, skb->dev->ifindex, udptable);
+	if (sk == NULL) {
+		ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
+		return;	/* No socket for error */
+	}
+
+	err = 0;
+	harderr = 0;
+	inet = inet_sk(sk);
+
+	switch (type) {
+	default:
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	case ICMP_SOURCE_QUENCH:
+		goto out;
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		harderr = 1;
+		break;
+	case ICMP_DEST_UNREACH:
+		if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
+			if (inet->pmtudisc != IP_PMTUDISC_DONT) {
+				err = EMSGSIZE;
+				harderr = 1;
+				break;
+			}
+			goto out;
+		}
+		err = EHOSTUNREACH;
+		if (code <= NR_ICMP_UNREACH) {
+			harderr = icmp_err_convert[code].fatal;
+			err = icmp_err_convert[code].errno;
+		}
+		break;
+	}
+
+	/*
+	 *      RFC1122: OK.  Passes ICMP errors back to application, as per
+	 *	4.1.3.3.
+	 */
+	if (!inet->recverr) {
+		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
+			goto out;
+	} else {
+		ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
+	}
+	sk->sk_err = err;
+	sk->sk_error_report(sk);
+out:
+	sock_put(sk);
+}
+
+void udp_err(struct sk_buff *skb, u32 info)
+{
+	__udp4_lib_err(skb, info, udp_hash);
+}
+
+/*
+ * Throw away all pending data and cancel the corking. Socket is locked.
+ */
+void udp_flush_pending_frames(struct sock *sk)
+{
+	struct udp_sock *up = udp_sk(sk);
+
+	if (up->pending) {
+		up->len = 0;
+		up->pending = 0;
+		ip_flush_pending_frames(sk);
+	}
+}
+EXPORT_SYMBOL(udp_flush_pending_frames);
+
+/**
+ * 	udp4_hwcsum_outgoing  -  handle outgoing HW checksumming
+ * 	@sk: 	socket we are sending on
+ * 	@skb: 	sk_buff containing the filled-in UDP header
+ * 	        (checksum field must be zeroed out)
+ */
+static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
+				 __be32 src, __be32 dst, int len      )
+{
+	unsigned int offset;
+	struct udphdr *uh = udp_hdr(skb);
+	__wsum csum = 0;
+
+	if (skb_queue_len(&sk->sk_write_queue) == 1) {
+		/*
+		 * Only one fragment on the socket.
+		 */
+		skb->csum_start = skb_transport_header(skb) - skb->head;
+		skb->csum_offset = offsetof(struct udphdr, check);
+		uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
+	} else {
+		/*
+		 * HW-checksum won't work as there are two or more
+		 * fragments on the socket so that all csums of sk_buffs
+		 * should be together
+		 */
+		offset = skb_transport_offset(skb);
+		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+		skb->ip_summed = CHECKSUM_NONE;
+
+		skb_queue_walk(&sk->sk_write_queue, skb) {
+			csum = csum_add(csum, skb->csum);
+		}
+
+		uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+	}
+}
+
+/*
+ * Push out all pending data as one UDP datagram. Socket is locked.
+ */
+static int udp_push_pending_frames(struct sock *sk)
+{
+	struct udp_sock  *up = udp_sk(sk);
+	struct inet_sock *inet = inet_sk(sk);
+	struct flowi *fl = &inet->cork.fl;
+	struct sk_buff *skb;
+	struct udphdr *uh;
+	int err = 0;
+	int is_udplite = IS_UDPLITE(sk);
+	__wsum csum = 0;
+
+	/* Grab the skbuff where UDP header space exists. */
+	if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
+		goto out;
+
+	/*
+	 * Create a UDP header
+	 */
+	uh = udp_hdr(skb);
+	uh->source = fl->fl_ip_sport;
+	uh->dest = fl->fl_ip_dport;
+	uh->len = htons(up->len);
+	uh->check = 0;
+
+	if (is_udplite)  				 /*     UDP-Lite      */
+		csum  = udplite_csum_outgoing(sk, skb);
+
+	else if (sk->sk_no_check == UDP_CSUM_NOXMIT) {   /* UDP csum disabled */
+
+		skb->ip_summed = CHECKSUM_NONE;
+		goto send;
+
+	} else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */
+
+		udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
+		goto send;
+
+	} else						 /*   `normal' UDP    */
+		csum = udp_csum_outgoing(sk, skb);
+
+	/* add protocol-dependent pseudo-header */
+	uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
+				      sk->sk_protocol, csum             );
+	if (uh->check == 0)
+		uh->check = CSUM_MANGLED_0;
+
+send:
+	err = ip_push_pending_frames(sk);
+out:
+	up->len = 0;
+	up->pending = 0;
+	if (!err)
+		UDP_INC_STATS_USER(sock_net(sk),
+				UDP_MIB_OUTDATAGRAMS, is_udplite);
+	return err;
+}
+
+int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		size_t len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct udp_sock *up = udp_sk(sk);
+	int ulen = len;
+	struct ipcm_cookie ipc;
+	struct rtable *rt = NULL;
+	int free = 0;
+	int connected = 0;
+	__be32 daddr, faddr, saddr;
+	__be16 dport;
+	u8  tos;
+	int err, is_udplite = IS_UDPLITE(sk);
+	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
+	int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
+
+	if (len > 0xFFFF)
+		return -EMSGSIZE;
+
+	/*
+	 *	Check the flags.
+	 */
+
+	if (msg->msg_flags&MSG_OOB)	/* Mirror BSD error message compatibility */
+		return -EOPNOTSUPP;
+
+	ipc.opt = NULL;
+
+	if (up->pending) {
+		/*
+		 * There are pending frames.
+		 * The socket lock must be held while it's corked.
+		 */
+		lock_sock(sk);
+		if (likely(up->pending)) {
+			if (unlikely(up->pending != AF_INET)) {
+				release_sock(sk);
+				return -EINVAL;
+			}
+			goto do_append_data;
+		}
+		release_sock(sk);
+	}
+	ulen += sizeof(struct udphdr);
+
+	/*
+	 *	Get and verify the address.
+	 */
+	if (msg->msg_name) {
+		struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
+		if (msg->msg_namelen < sizeof(*usin))
+			return -EINVAL;
+		if (usin->sin_family != AF_INET) {
+			if (usin->sin_family != AF_UNSPEC)
+				return -EAFNOSUPPORT;
+		}
+
+		daddr = usin->sin_addr.s_addr;
+		dport = usin->sin_port;
+		if (dport == 0)
+			return -EINVAL;
+	} else {
+		if (sk->sk_state != TCP_ESTABLISHED)
+			return -EDESTADDRREQ;
+		daddr = inet->daddr;
+		dport = inet->dport;
+		/* Open fast path for connected socket.
+		   Route will not be used, if at least one option is set.
+		 */
+		connected = 1;
+	}
+	ipc.addr = inet->saddr;
+
+	ipc.oif = sk->sk_bound_dev_if;
+	if (msg->msg_controllen) {
+		err = ip_cmsg_send(sock_net(sk), msg, &ipc);
+		if (err)
+			return err;
+		if (ipc.opt)
+			free = 1;
+		connected = 0;
+	}
+	if (!ipc.opt)
+		ipc.opt = inet->opt;
+
+	saddr = ipc.addr;
+	ipc.addr = faddr = daddr;
+
+	if (ipc.opt && ipc.opt->srr) {
+		if (!daddr)
+			return -EINVAL;
+		faddr = ipc.opt->faddr;
+		connected = 0;
+	}
+	tos = RT_TOS(inet->tos);
+	if (sock_flag(sk, SOCK_LOCALROUTE) ||
+	    (msg->msg_flags & MSG_DONTROUTE) ||
+	    (ipc.opt && ipc.opt->is_strictroute)) {
+		tos |= RTO_ONLINK;
+		connected = 0;
+	}
+
+	if (ipv4_is_multicast(daddr)) {
+		if (!ipc.oif)
+			ipc.oif = inet->mc_index;
+		if (!saddr)
+			saddr = inet->mc_addr;
+		connected = 0;
+	}
+
+	if (connected)
+		rt = (struct rtable*)sk_dst_check(sk, 0);
+
+	if (rt == NULL) {
+		struct flowi fl = { .oif = ipc.oif,
+				    .nl_u = { .ip4_u =
+					      { .daddr = faddr,
+						.saddr = saddr,
+						.tos = tos } },
+				    .proto = sk->sk_protocol,
+				    .flags = inet_sk_flowi_flags(sk),
+				    .uli_u = { .ports =
+					       { .sport = inet->sport,
+						 .dport = dport } } };
+		struct net *net = sock_net(sk);
+
+		security_sk_classify_flow(sk, &fl);
+		err = ip_route_output_flow(net, &rt, &fl, sk, 1);
+		if (err) {
+			if (err == -ENETUNREACH)
+				IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+			goto out;
+		}
+
+		err = -EACCES;
+		if ((rt->rt_flags & RTCF_BROADCAST) &&
+		    !sock_flag(sk, SOCK_BROADCAST))
+			goto out;
+		if (connected)
+			sk_dst_set(sk, dst_clone(&rt->u.dst));
+	}
+
+	if (msg->msg_flags&MSG_CONFIRM)
+		goto do_confirm;
+back_from_confirm:
+
+	saddr = rt->rt_src;
+	if (!ipc.addr)
+		daddr = ipc.addr = rt->rt_dst;
+
+	lock_sock(sk);
+	if (unlikely(up->pending)) {
+		/* The socket is already corked while preparing it. */
+		/* ... which is an evident application bug. --ANK */
+		release_sock(sk);
+
+		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
+		err = -EINVAL;
+		goto out;
+	}
+	/*
+	 *	Now cork the socket to pend data.
+	 */
+	inet->cork.fl.fl4_dst = daddr;
+	inet->cork.fl.fl_ip_dport = dport;
+	inet->cork.fl.fl4_src = saddr;
+	inet->cork.fl.fl_ip_sport = inet->sport;
+	up->pending = AF_INET;
+
+do_append_data:
+	up->len += ulen;
+	getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
+	err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
+			sizeof(struct udphdr), &ipc, rt,
+			corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
+	if (err)
+		udp_flush_pending_frames(sk);
+	else if (!corkreq)
+		err = udp_push_pending_frames(sk);
+	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
+		up->pending = 0;
+	release_sock(sk);
+
+out:
+	ip_rt_put(rt);
+	if (free)
+		kfree(ipc.opt);
+	if (!err)
+		return len;
+	/*
+	 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
+	 * ENOBUFS might not be good (it's not tunable per se), but otherwise
+	 * we don't have a good statistic (IpOutDiscards but it can be too many
+	 * things).  We could add another new stat but at least for now that
+	 * seems like overkill.
+	 */
+	if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
+		UDP_INC_STATS_USER(sock_net(sk),
+				UDP_MIB_SNDBUFERRORS, is_udplite);
+	}
+	return err;
+
+do_confirm:
+	dst_confirm(&rt->u.dst);
+	if (!(msg->msg_flags&MSG_PROBE) || len)
+		goto back_from_confirm;
+	err = 0;
+	goto out;
+}
+
+int udp_sendpage(struct sock *sk, struct page *page, int offset,
+		 size_t size, int flags)
+{
+	struct udp_sock *up = udp_sk(sk);
+	int ret;
+
+	if (!up->pending) {
+		struct msghdr msg = {	.msg_flags = flags|MSG_MORE };
+
+		/* Call udp_sendmsg to specify destination address which
+		 * sendpage interface can't pass.
+		 * This will succeed only when the socket is connected.
+		 */
+		ret = udp_sendmsg(NULL, sk, &msg, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	lock_sock(sk);
+
+	if (unlikely(!up->pending)) {
+		release_sock(sk);
+
+		LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
+		return -EINVAL;
+	}
+
+	ret = ip_append_page(sk, page, offset, size, flags);
+	if (ret == -EOPNOTSUPP) {
+		release_sock(sk);
+		return sock_no_sendpage(sk->sk_socket, page, offset,
+					size, flags);
+	}
+	if (ret < 0) {
+		udp_flush_pending_frames(sk);
+		goto out;
+	}
+
+	up->len += size;
+	if (!(up->corkflag || (flags&MSG_MORE)))
+		ret = udp_push_pending_frames(sk);
+	if (!ret)
+		ret = size;
+out:
+	release_sock(sk);
+	return ret;
+}
+
+/*
+ *	IOCTL requests applicable to the UDP protocol
+ */
+
+int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SIOCOUTQ:
+	{
+		int amount = atomic_read(&sk->sk_wmem_alloc);
+		return put_user(amount, (int __user *)arg);
+	}
+
+	case SIOCINQ:
+	{
+		struct sk_buff *skb;
+		unsigned long amount;
+
+		amount = 0;
+		spin_lock_bh(&sk->sk_receive_queue.lock);
+		skb = skb_peek(&sk->sk_receive_queue);
+		if (skb != NULL) {
+			/*
+			 * We will only return the amount
+			 * of this packet since that is all
+			 * that will be read.
+			 */
+			amount = skb->len - sizeof(struct udphdr);
+		}
+		spin_unlock_bh(&sk->sk_receive_queue.lock);
+		return put_user(amount, (int __user *)arg);
+	}
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+/*
+ * 	This should be easy, if there is something there we
+ * 	return it, otherwise we block.
+ */
+
+int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		size_t len, int noblock, int flags, int *addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
+	struct sk_buff *skb;
+	unsigned int ulen, copied;
+	int peeked;
+	int err;
+	int is_udplite = IS_UDPLITE(sk);
+
+	/*
+	 *	Check any passed addresses
+	 */
+	if (addr_len)
+		*addr_len=sizeof(*sin);
+
+	if (flags & MSG_ERRQUEUE)
+		return ip_recv_error(sk, msg, len);
+
+try_again:
+	skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
+				  &peeked, &err);
+	if (!skb)
+		goto out;
+
+	ulen = skb->len - sizeof(struct udphdr);
+	copied = len;
+	if (copied > ulen)
+		copied = ulen;
+	else if (copied < ulen)
+		msg->msg_flags |= MSG_TRUNC;
+
+	/*
+	 * If checksum is needed at all, try to do it while copying the
+	 * data.  If the data is truncated, or if we only want a partial
+	 * coverage checksum (UDP-Lite), do it before the copy.
+	 */
+
+	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
+		if (udp_lib_checksum_complete(skb))
+			goto csum_copy_err;
+	}
+
+	if (skb_csum_unnecessary(skb))
+		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
+					      msg->msg_iov, copied       );
+	else {
+		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
+
+		if (err == -EINVAL)
+			goto csum_copy_err;
+	}
+
+	if (err)
+		goto out_free;
+
+	if (!peeked)
+		UDP_INC_STATS_USER(sock_net(sk),
+				UDP_MIB_INDATAGRAMS, is_udplite);
+
+	sock_recv_timestamp(msg, sk, skb);
+
+	/* Copy the address. */
+	if (sin)
+	{
+		sin->sin_family = AF_INET;
+		sin->sin_port = udp_hdr(skb)->source;
+		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
+		memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
+	}
+	if (inet->cmsg_flags)
+		ip_cmsg_recv(msg, skb);
+
+	err = copied;
+	if (flags & MSG_TRUNC)
+		err = ulen;
+
+out_free:
+	lock_sock(sk);
+	skb_free_datagram(sk, skb);
+	release_sock(sk);
+out:
+	return err;
+
+csum_copy_err:
+	lock_sock(sk);
+	if (!skb_kill_datagram(sk, skb, flags))
+		UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+	release_sock(sk);
+
+	if (noblock)
+		return -EAGAIN;
+	goto try_again;
+}
+
+
+int udp_disconnect(struct sock *sk, int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	/*
+	 *	1003.1g - break association.
+	 */
+
+	sk->sk_state = TCP_CLOSE;
+	inet->daddr = 0;
+	inet->dport = 0;
+	sk->sk_bound_dev_if = 0;
+	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
+		inet_reset_saddr(sk);
+
+	if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
+		sk->sk_prot->unhash(sk);
+		inet->sport = 0;
+	}
+	sk_dst_reset(sk);
+	return 0;
+}
+
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	int is_udplite = IS_UDPLITE(sk);
+	int rc;
+
+	if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
+		/* Note that an ENOMEM error is charged twice */
+		if (rc == -ENOMEM) {
+			UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
+					 is_udplite);
+			atomic_inc(&sk->sk_drops);
+		}
+		goto drop;
+	}
+
+	return 0;
+
+drop:
+	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+	kfree_skb(skb);
+	return -1;
+}
+
+/* returns:
+ *  -1: error
+ *   0: success
+ *  >0: "udp encap" protocol resubmission
+ *
+ * Note that in the success and error cases, the skb is assumed to
+ * have either been requeued or freed.
+ */
+int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+{
+	struct udp_sock *up = udp_sk(sk);
+	int rc;
+	int is_udplite = IS_UDPLITE(sk);
+
+	/*
+	 *	Charge it to the socket, dropping if the queue is full.
+	 */
+	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
+		goto drop;
+	nf_reset(skb);
+
+	if (up->encap_type) {
+		/*
+		 * This is an encapsulation socket so pass the skb to
+		 * the socket's udp_encap_rcv() hook. Otherwise, just
+		 * fall through and pass this up the UDP socket.
+		 * up->encap_rcv() returns the following value:
+		 * =0 if skb was successfully passed to the encap
+		 *    handler or was discarded by it.
+		 * >0 if skb should be passed on to UDP.
+		 * <0 if skb should be resubmitted as proto -N
+		 */
+
+		/* if we're overly short, let UDP handle it */
+		if (skb->len > sizeof(struct udphdr) &&
+		    up->encap_rcv != NULL) {
+			int ret;
+
+			ret = (*up->encap_rcv)(sk, skb);
+			if (ret <= 0) {
+				UDP_INC_STATS_BH(sock_net(sk),
+						 UDP_MIB_INDATAGRAMS,
+						 is_udplite);
+				return -ret;
+			}
+		}
+
+		/* FALLTHROUGH -- it's a UDP Packet */
+	}
+
+	/*
+	 * 	UDP-Lite specific tests, ignored on UDP sockets
+	 */
+	if ((is_udplite & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {
+
+		/*
+		 * MIB statistics other than incrementing the error count are
+		 * disabled for the following two types of errors: these depend
+		 * on the application settings, not on the functioning of the
+		 * protocol stack as such.
+		 *
+		 * RFC 3828 here recommends (sec 3.3): "There should also be a
+		 * way ... to ... at least let the receiving application block
+		 * delivery of packets with coverage values less than a value
+		 * provided by the application."
+		 */
+		if (up->pcrlen == 0) {          /* full coverage was set  */
+			LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
+				"%d while full coverage %d requested\n",
+				UDP_SKB_CB(skb)->cscov, skb->len);
+			goto drop;
+		}
+		/* The next case involves violating the min. coverage requested
+		 * by the receiver. This is subtle: if receiver wants x and x is
+		 * greater than the buffersize/MTU then receiver will complain
+		 * that it wants x while sender emits packets of smaller size y.
+		 * Therefore the above ...()->partial_cov statement is essential.
+		 */
+		if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
+			LIMIT_NETDEBUG(KERN_WARNING
+				"UDPLITE: coverage %d too small, need min %d\n",
+				UDP_SKB_CB(skb)->cscov, up->pcrlen);
+			goto drop;
+		}
+	}
+
+	if (sk->sk_filter) {
+		if (udp_lib_checksum_complete(skb))
+			goto drop;
+	}
+
+	rc = 0;
+
+	bh_lock_sock(sk);
+	if (!sock_owned_by_user(sk))
+		rc = __udp_queue_rcv_skb(sk, skb);
+	else
+		sk_add_backlog(sk, skb);
+	bh_unlock_sock(sk);
+
+	return rc;
+
+drop:
+	UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+	kfree_skb(skb);
+	return -1;
+}
+
+/*
+ *	Multicasts and broadcasts go to each listener.
+ *
+ *	Note: called only from the BH handler context,
+ *	so we don't need to lock the hashes.
+ */
+static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
+				    struct udphdr  *uh,
+				    __be32 saddr, __be32 daddr,
+				    struct hlist_head udptable[])
+{
+	struct sock *sk;
+	int dif;
+
+	read_lock(&udp_hash_lock);
+	sk = sk_head(&udptable[udp_hashfn(net, ntohs(uh->dest))]);
+	dif = skb->dev->ifindex;
+	sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
+	if (sk) {
+		struct sock *sknext = NULL;
+
+		do {
+			struct sk_buff *skb1 = skb;
+
+			sknext = udp_v4_mcast_next(net, sk_next(sk), uh->dest,
+						   daddr, uh->source, saddr,
+						   dif);
+			if (sknext)
+				skb1 = skb_clone(skb, GFP_ATOMIC);
+
+			if (skb1) {
+				int ret = udp_queue_rcv_skb(sk, skb1);
+				if (ret > 0)
+					/* we should probably re-process instead
+					 * of dropping packets here. */
+					kfree_skb(skb1);
+			}
+			sk = sknext;
+		} while (sknext);
+	} else
+		kfree_skb(skb);
+	read_unlock(&udp_hash_lock);
+	return 0;
+}
+
+/* Initialize UDP checksum. If exited with zero value (success),
+ * CHECKSUM_UNNECESSARY means, that no more checks are required.
+ * Otherwise, csum completion requires chacksumming packet body,
+ * including udp header and folding it to skb->csum.
+ */
+static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
+				 int proto)
+{
+	const struct iphdr *iph;
+	int err;
+
+	UDP_SKB_CB(skb)->partial_cov = 0;
+	UDP_SKB_CB(skb)->cscov = skb->len;
+
+	if (proto == IPPROTO_UDPLITE) {
+		err = udplite_checksum_init(skb, uh);
+		if (err)
+			return err;
+	}
+
+	iph = ip_hdr(skb);
+	if (uh->check == 0) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	} else if (skb->ip_summed == CHECKSUM_COMPLETE) {
+	       if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
+				      proto, skb->csum))
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+	if (!skb_csum_unnecessary(skb))
+		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
+					       skb->len, proto, 0);
+	/* Probably, we should checksum udp header (it should be in cache
+	 * in any case) and data in tiny packets (< rx copybreak).
+	 */
+
+	return 0;
+}
+
+/*
+ *	All we need to do is get the socket, and then do a checksum.
+ */
+
+int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
+		   int proto)
+{
+	struct sock *sk;
+	struct udphdr *uh;
+	unsigned short ulen;
+	struct rtable *rt = (struct rtable*)skb->dst;
+	__be32 saddr = ip_hdr(skb)->saddr;
+	__be32 daddr = ip_hdr(skb)->daddr;
+	struct net *net = dev_net(skb->dev);
+
+	/*
+	 *  Validate the packet.
+	 */
+	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+		goto drop;		/* No space for header. */
+
+	uh   = udp_hdr(skb);
+	ulen = ntohs(uh->len);
+	if (ulen > skb->len)
+		goto short_packet;
+
+	if (proto == IPPROTO_UDP) {
+		/* UDP validates ulen. */
+		if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
+			goto short_packet;
+		uh = udp_hdr(skb);
+	}
+
+	if (udp4_csum_init(skb, uh, proto))
+		goto csum_error;
+
+	if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
+		return __udp4_lib_mcast_deliver(net, skb, uh,
+				saddr, daddr, udptable);
+
+	sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
+
+	if (sk != NULL) {
+		int ret = udp_queue_rcv_skb(sk, skb);
+		sock_put(sk);
+
+		/* a return value > 0 means to resubmit the input, but
+		 * it wants the return to be -protocol, or 0
+		 */
+		if (ret > 0)
+			return -ret;
+		return 0;
+	}
+
+	if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
+		goto drop;
+	nf_reset(skb);
+
+	/* No socket. Drop packet silently, if checksum is wrong */
+	if (udp_lib_checksum_complete(skb))
+		goto csum_error;
+
+	UDP_INC_STATS_BH(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
+	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+	/*
+	 * Hmm.  We got an UDP packet to a port to which we
+	 * don't wanna listen.  Ignore it.
+	 */
+	kfree_skb(skb);
+	return 0;
+
+short_packet:
+	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From " NIPQUAD_FMT ":%u %d/%d to " NIPQUAD_FMT ":%u\n",
+		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
+		       NIPQUAD(saddr),
+		       ntohs(uh->source),
+		       ulen,
+		       skb->len,
+		       NIPQUAD(daddr),
+		       ntohs(uh->dest));
+	goto drop;
+
+csum_error:
+	/*
+	 * RFC1122: OK.  Discards the bad packet silently (as far as
+	 * the network is concerned, anyway) as per 4.1.3.4 (MUST).
+	 */
+	LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From " NIPQUAD_FMT ":%u to " NIPQUAD_FMT ":%u ulen %d\n",
+		       proto == IPPROTO_UDPLITE ? "-Lite" : "",
+		       NIPQUAD(saddr),
+		       ntohs(uh->source),
+		       NIPQUAD(daddr),
+		       ntohs(uh->dest),
+		       ulen);
+drop:
+	UDP_INC_STATS_BH(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
+	kfree_skb(skb);
+	return 0;
+}
+
+int udp_rcv(struct sk_buff *skb)
+{
+	return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
+}
+
+void udp_destroy_sock(struct sock *sk)
+{
+	lock_sock(sk);
+	udp_flush_pending_frames(sk);
+	release_sock(sk);
+}
+
+/*
+ *	Socket option code for UDP
+ */
+int udp_lib_setsockopt(struct sock *sk, int level, int optname,
+		       char __user *optval, int optlen,
+		       int (*push_pending_frames)(struct sock *))
+{
+	struct udp_sock *up = udp_sk(sk);
+	int val;
+	int err = 0;
+	int is_udplite = IS_UDPLITE(sk);
+
+	if (optlen<sizeof(int))
+		return -EINVAL;
+
+	if (get_user(val, (int __user *)optval))
+		return -EFAULT;
+
+	switch (optname) {
+	case UDP_CORK:
+		if (val != 0) {
+			up->corkflag = 1;
+		} else {
+			up->corkflag = 0;
+			lock_sock(sk);
+			(*push_pending_frames)(sk);
+			release_sock(sk);
+		}
+		break;
+
+	case UDP_ENCAP:
+		switch (val) {
+		case 0:
+		case UDP_ENCAP_ESPINUDP:
+		case UDP_ENCAP_ESPINUDP_NON_IKE:
+			up->encap_rcv = xfrm4_udp_encap_rcv;
+			/* FALLTHROUGH */
+		case UDP_ENCAP_L2TPINUDP:
+			up->encap_type = val;
+			break;
+		default:
+			err = -ENOPROTOOPT;
+			break;
+		}
+		break;
+
+	/*
+	 * 	UDP-Lite's partial checksum coverage (RFC 3828).
+	 */
+	/* The sender sets actual checksum coverage length via this option.
+	 * The case coverage > packet length is handled by send module. */
+	case UDPLITE_SEND_CSCOV:
+		if (!is_udplite)         /* Disable the option on UDP sockets */
+			return -ENOPROTOOPT;
+		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
+			val = 8;
+		else if (val > USHORT_MAX)
+			val = USHORT_MAX;
+		up->pcslen = val;
+		up->pcflag |= UDPLITE_SEND_CC;
+		break;
+
+	/* The receiver specifies a minimum checksum coverage value. To make
+	 * sense, this should be set to at least 8 (as done below). If zero is
+	 * used, this again means full checksum coverage.                     */
+	case UDPLITE_RECV_CSCOV:
+		if (!is_udplite)         /* Disable the option on UDP sockets */
+			return -ENOPROTOOPT;
+		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
+			val = 8;
+		else if (val > USHORT_MAX)
+			val = USHORT_MAX;
+		up->pcrlen = val;
+		up->pcflag |= UDPLITE_RECV_CC;
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	}
+
+	return err;
+}
+
+int udp_setsockopt(struct sock *sk, int level, int optname,
+		   char __user *optval, int optlen)
+{
+	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+					  udp_push_pending_frames);
+	return ip_setsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_udp_setsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int optlen)
+{
+	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+					  udp_push_pending_frames);
+	return compat_ip_setsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+
+int udp_lib_getsockopt(struct sock *sk, int level, int optname,
+		       char __user *optval, int __user *optlen)
+{
+	struct udp_sock *up = udp_sk(sk);
+	int val, len;
+
+	if (get_user(len,optlen))
+		return -EFAULT;
+
+	len = min_t(unsigned int, len, sizeof(int));
+
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+	case UDP_CORK:
+		val = up->corkflag;
+		break;
+
+	case UDP_ENCAP:
+		val = up->encap_type;
+		break;
+
+	/* The following two cannot be changed on UDP sockets, the return is
+	 * always 0 (which corresponds to the full checksum coverage of UDP). */
+	case UDPLITE_SEND_CSCOV:
+		val = up->pcslen;
+		break;
+
+	case UDPLITE_RECV_CSCOV:
+		val = up->pcrlen;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	if (put_user(len, optlen))
+		return -EFAULT;
+	if (copy_to_user(optval, &val,len))
+		return -EFAULT;
+	return 0;
+}
+
+int udp_getsockopt(struct sock *sk, int level, int optname,
+		   char __user *optval, int __user *optlen)
+{
+	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
+	return ip_getsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_udp_getsockopt(struct sock *sk, int level, int optname,
+				 char __user *optval, int __user *optlen)
+{
+	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
+		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
+	return compat_ip_getsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+/**
+ * 	udp_poll - wait for a UDP event.
+ *	@file - file struct
+ *	@sock - socket
+ *	@wait - poll table
+ *
+ *	This is same as datagram poll, except for the special case of
+ *	blocking sockets. If application is using a blocking fd
+ *	and a packet with checksum error is in the queue;
+ *	then it could get return from select indicating data available
+ *	but then block when reading it. Add special case code
+ *	to work around these arguably broken applications.
+ */
+unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+	unsigned int mask = datagram_poll(file, sock, wait);
+	struct sock *sk = sock->sk;
+	int 	is_lite = IS_UDPLITE(sk);
+
+	/* Check for false positives due to checksum errors */
+	if ( (mask & POLLRDNORM) &&
+	     !(file->f_flags & O_NONBLOCK) &&
+	     !(sk->sk_shutdown & RCV_SHUTDOWN)){
+		struct sk_buff_head *rcvq = &sk->sk_receive_queue;
+		struct sk_buff *skb;
+
+		spin_lock_bh(&rcvq->lock);
+		while ((skb = skb_peek(rcvq)) != NULL &&
+		       udp_lib_checksum_complete(skb)) {
+			UDP_INC_STATS_BH(sock_net(sk),
+					UDP_MIB_INERRORS, is_lite);
+			__skb_unlink(skb, rcvq);
+			kfree_skb(skb);
+		}
+		spin_unlock_bh(&rcvq->lock);
+
+		/* nothing to see, move along */
+		if (skb == NULL)
+			mask &= ~(POLLIN | POLLRDNORM);
+	}
+
+	return mask;
+
+}
+
+struct proto udp_prot = {
+	.name		   = "UDP",
+	.owner		   = THIS_MODULE,
+	.close		   = udp_lib_close,
+	.connect	   = ip4_datagram_connect,
+	.disconnect	   = udp_disconnect,
+	.ioctl		   = udp_ioctl,
+	.destroy	   = udp_destroy_sock,
+	.setsockopt	   = udp_setsockopt,
+	.getsockopt	   = udp_getsockopt,
+	.sendmsg	   = udp_sendmsg,
+	.recvmsg	   = udp_recvmsg,
+	.sendpage	   = udp_sendpage,
+	.backlog_rcv	   = __udp_queue_rcv_skb,
+	.hash		   = udp_lib_hash,
+	.unhash		   = udp_lib_unhash,
+	.get_port	   = udp_v4_get_port,
+	.memory_allocated  = &udp_memory_allocated,
+	.sysctl_mem	   = sysctl_udp_mem,
+	.sysctl_wmem	   = &sysctl_udp_wmem_min,
+	.sysctl_rmem	   = &sysctl_udp_rmem_min,
+	.obj_size	   = sizeof(struct udp_sock),
+	.h.udp_hash	   = udp_hash,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_udp_setsockopt,
+	.compat_getsockopt = compat_udp_getsockopt,
+#endif
+};
+
+/* ------------------------------------------------------------------------ */
+#ifdef CONFIG_PROC_FS
+
+static struct sock *udp_get_first(struct seq_file *seq)
+{
+	struct sock *sk;
+	struct udp_iter_state *state = seq->private;
+	struct net *net = seq_file_net(seq);
+
+	for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
+		struct hlist_node *node;
+		sk_for_each(sk, node, state->hashtable + state->bucket) {
+			if (!net_eq(sock_net(sk), net))
+				continue;
+			if (sk->sk_family == state->family)
+				goto found;
+		}
+	}
+	sk = NULL;
+found:
+	return sk;
+}
+
+static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
+{
+	struct udp_iter_state *state = seq->private;
+	struct net *net = seq_file_net(seq);
+
+	do {
+		sk = sk_next(sk);
+try_again:
+		;
+	} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
+
+	if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
+		sk = sk_head(state->hashtable + state->bucket);
+		goto try_again;
+	}
+	return sk;
+}
+
+static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct sock *sk = udp_get_first(seq);
+
+	if (sk)
+		while (pos && (sk = udp_get_next(seq, sk)) != NULL)
+			--pos;
+	return pos ? NULL : sk;
+}
+
+static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(udp_hash_lock)
+{
+	read_lock(&udp_hash_lock);
+	return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
+}
+
+static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct sock *sk;
+
+	if (v == SEQ_START_TOKEN)
+		sk = udp_get_idx(seq, 0);
+	else
+		sk = udp_get_next(seq, v);
+
+	++*pos;
+	return sk;
+}
+
+static void udp_seq_stop(struct seq_file *seq, void *v)
+	__releases(udp_hash_lock)
+{
+	read_unlock(&udp_hash_lock);
+}
+
+static int udp_seq_open(struct inode *inode, struct file *file)
+{
+	struct udp_seq_afinfo *afinfo = PDE(inode)->data;
+	struct udp_iter_state *s;
+	int err;
+
+	err = seq_open_net(inode, file, &afinfo->seq_ops,
+			   sizeof(struct udp_iter_state));
+	if (err < 0)
+		return err;
+
+	s = ((struct seq_file *)file->private_data)->private;
+	s->family		= afinfo->family;
+	s->hashtable		= afinfo->hashtable;
+	return err;
+}
+
+/* ------------------------------------------------------------------------ */
+int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo)
+{
+	struct proc_dir_entry *p;
+	int rc = 0;
+
+	afinfo->seq_fops.open		= udp_seq_open;
+	afinfo->seq_fops.read		= seq_read;
+	afinfo->seq_fops.llseek		= seq_lseek;
+	afinfo->seq_fops.release	= seq_release_net;
+
+	afinfo->seq_ops.start		= udp_seq_start;
+	afinfo->seq_ops.next		= udp_seq_next;
+	afinfo->seq_ops.stop		= udp_seq_stop;
+
+	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
+			     &afinfo->seq_fops, afinfo);
+	if (!p)
+		rc = -ENOMEM;
+	return rc;
+}
+
+void udp_proc_unregister(struct net *net, struct udp_seq_afinfo *afinfo)
+{
+	proc_net_remove(net, afinfo->name);
+}
+
+/* ------------------------------------------------------------------------ */
+static void udp4_format_sock(struct sock *sp, struct seq_file *f,
+		int bucket, int *len)
+{
+	struct inet_sock *inet = inet_sk(sp);
+	__be32 dest = inet->daddr;
+	__be32 src  = inet->rcv_saddr;
+	__u16 destp	  = ntohs(inet->dport);
+	__u16 srcp	  = ntohs(inet->sport);
+
+	seq_printf(f, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %d%n",
+		bucket, src, srcp, dest, destp, sp->sk_state,
+		atomic_read(&sp->sk_wmem_alloc),
+		atomic_read(&sp->sk_rmem_alloc),
+		0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
+		atomic_read(&sp->sk_refcnt), sp,
+		atomic_read(&sp->sk_drops), len);
+}
+
+int udp4_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_printf(seq, "%-127s\n",
+			   "  sl  local_address rem_address   st tx_queue "
+			   "rx_queue tr tm->when retrnsmt   uid  timeout "
+			   "inode ref pointer drops");
+	else {
+		struct udp_iter_state *state = seq->private;
+		int len;
+
+		udp4_format_sock(v, seq, state->bucket, &len);
+		seq_printf(seq, "%*s\n", 127 - len ,"");
+	}
+	return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+static struct udp_seq_afinfo udp4_seq_afinfo = {
+	.name		= "udp",
+	.family		= AF_INET,
+	.hashtable	= udp_hash,
+	.seq_fops	= {
+		.owner	=	THIS_MODULE,
+	},
+	.seq_ops	= {
+		.show		= udp4_seq_show,
+	},
+};
+
+static int udp4_proc_init_net(struct net *net)
+{
+	return udp_proc_register(net, &udp4_seq_afinfo);
+}
+
+static void udp4_proc_exit_net(struct net *net)
+{
+	udp_proc_unregister(net, &udp4_seq_afinfo);
+}
+
+static struct pernet_operations udp4_net_ops = {
+	.init = udp4_proc_init_net,
+	.exit = udp4_proc_exit_net,
+};
+
+int __init udp4_proc_init(void)
+{
+	return register_pernet_subsys(&udp4_net_ops);
+}
+
+void udp4_proc_exit(void)
+{
+	unregister_pernet_subsys(&udp4_net_ops);
+}
+#endif /* CONFIG_PROC_FS */
+
+void __init udp_init(void)
+{
+	unsigned long limit;
+
+	/* Set the pressure threshold up by the same strategy of TCP. It is a
+	 * fraction of global memory that is up to 1/2 at 256 MB, decreasing
+	 * toward zero with the amount of memory, with a floor of 128 pages.
+	 */
+	limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+	limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
+	limit = max(limit, 128UL);
+	sysctl_udp_mem[0] = limit / 4 * 3;
+	sysctl_udp_mem[1] = limit;
+	sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
+
+	sysctl_udp_rmem_min = SK_MEM_QUANTUM;
+	sysctl_udp_wmem_min = SK_MEM_QUANTUM;
+}
+
+EXPORT_SYMBOL(udp_disconnect);
+EXPORT_SYMBOL(udp_hash);
+EXPORT_SYMBOL(udp_hash_lock);
+EXPORT_SYMBOL(udp_ioctl);
+EXPORT_SYMBOL(udp_prot);
+EXPORT_SYMBOL(udp_sendmsg);
+EXPORT_SYMBOL(udp_lib_getsockopt);
+EXPORT_SYMBOL(udp_lib_setsockopt);
+EXPORT_SYMBOL(udp_poll);
+EXPORT_SYMBOL(udp_lib_get_port);
+
+#ifdef CONFIG_PROC_FS
+EXPORT_SYMBOL(udp_proc_register);
+EXPORT_SYMBOL(udp_proc_unregister);
+#endif
diff --git a/net/ipv4/udp_impl.h b/net/ipv4/udp_impl.h
new file mode 100644
index 0000000..2e9bad2
--- /dev/null
+++ b/net/ipv4/udp_impl.h
@@ -0,0 +1,34 @@
+#ifndef _UDP4_IMPL_H
+#define _UDP4_IMPL_H
+#include <net/udp.h>
+#include <net/udplite.h>
+#include <net/protocol.h>
+#include <net/inet_common.h>
+
+extern int  	__udp4_lib_rcv(struct sk_buff *, struct hlist_head [], int );
+extern void 	__udp4_lib_err(struct sk_buff *, u32, struct hlist_head []);
+
+extern int	udp_v4_get_port(struct sock *sk, unsigned short snum);
+
+extern int	udp_setsockopt(struct sock *sk, int level, int optname,
+			       char __user *optval, int optlen);
+extern int	udp_getsockopt(struct sock *sk, int level, int optname,
+			       char __user *optval, int __user *optlen);
+
+#ifdef CONFIG_COMPAT
+extern int	compat_udp_setsockopt(struct sock *sk, int level, int optname,
+				      char __user *optval, int optlen);
+extern int	compat_udp_getsockopt(struct sock *sk, int level, int optname,
+				      char __user *optval, int __user *optlen);
+#endif
+extern int	udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+			    size_t len, int noblock, int flags, int *addr_len);
+extern int	udp_sendpage(struct sock *sk, struct page *page, int offset,
+			     size_t size, int flags);
+extern int	udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb);
+extern void	udp_destroy_sock(struct sock *sk);
+
+#ifdef CONFIG_PROC_FS
+extern int	udp4_seq_show(struct seq_file *seq, void *v);
+#endif
+#endif	/* _UDP4_IMPL_H */
diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c
new file mode 100644
index 0000000..3c80796
--- /dev/null
+++ b/net/ipv4/udplite.c
@@ -0,0 +1,130 @@
+/*
+ *  UDPLITE     An implementation of the UDP-Lite protocol (RFC 3828).
+ *
+ *  Authors:    Gerrit Renker       <gerrit@erg.abdn.ac.uk>
+ *
+ *  Changes:
+ *  Fixes:
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#include "udp_impl.h"
+
+struct hlist_head 	udplite_hash[UDP_HTABLE_SIZE];
+
+static int udplite_rcv(struct sk_buff *skb)
+{
+	return __udp4_lib_rcv(skb, udplite_hash, IPPROTO_UDPLITE);
+}
+
+static void udplite_err(struct sk_buff *skb, u32 info)
+{
+	__udp4_lib_err(skb, info, udplite_hash);
+}
+
+static	struct net_protocol udplite_protocol = {
+	.handler	= udplite_rcv,
+	.err_handler	= udplite_err,
+	.no_policy	= 1,
+	.netns_ok	= 1,
+};
+
+struct proto 	udplite_prot = {
+	.name		   = "UDP-Lite",
+	.owner		   = THIS_MODULE,
+	.close		   = udp_lib_close,
+	.connect	   = ip4_datagram_connect,
+	.disconnect	   = udp_disconnect,
+	.ioctl		   = udp_ioctl,
+	.init		   = udplite_sk_init,
+	.destroy	   = udp_destroy_sock,
+	.setsockopt	   = udp_setsockopt,
+	.getsockopt	   = udp_getsockopt,
+	.sendmsg	   = udp_sendmsg,
+	.recvmsg	   = udp_recvmsg,
+	.sendpage	   = udp_sendpage,
+	.backlog_rcv	   = udp_queue_rcv_skb,
+	.hash		   = udp_lib_hash,
+	.unhash		   = udp_lib_unhash,
+	.get_port	   = udp_v4_get_port,
+	.obj_size	   = sizeof(struct udp_sock),
+	.h.udp_hash	   = udplite_hash,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt = compat_udp_setsockopt,
+	.compat_getsockopt = compat_udp_getsockopt,
+#endif
+};
+
+static struct inet_protosw udplite4_protosw = {
+	.type		=  SOCK_DGRAM,
+	.protocol	=  IPPROTO_UDPLITE,
+	.prot		=  &udplite_prot,
+	.ops		=  &inet_dgram_ops,
+	.capability	= -1,
+	.no_check	=  0,		/* must checksum (RFC 3828) */
+	.flags		=  INET_PROTOSW_PERMANENT,
+};
+
+#ifdef CONFIG_PROC_FS
+static struct udp_seq_afinfo udplite4_seq_afinfo = {
+	.name		= "udplite",
+	.family		= AF_INET,
+	.hashtable	= udplite_hash,
+	.seq_fops	= {
+		.owner	=	THIS_MODULE,
+	},
+	.seq_ops	= {
+		.show		= udp4_seq_show,
+	},
+};
+
+static int udplite4_proc_init_net(struct net *net)
+{
+	return udp_proc_register(net, &udplite4_seq_afinfo);
+}
+
+static void udplite4_proc_exit_net(struct net *net)
+{
+	udp_proc_unregister(net, &udplite4_seq_afinfo);
+}
+
+static struct pernet_operations udplite4_net_ops = {
+	.init = udplite4_proc_init_net,
+	.exit = udplite4_proc_exit_net,
+};
+
+static __init int udplite4_proc_init(void)
+{
+	return register_pernet_subsys(&udplite4_net_ops);
+}
+#else
+static inline int udplite4_proc_init(void)
+{
+	return 0;
+}
+#endif
+
+void __init udplite4_register(void)
+{
+	if (proto_register(&udplite_prot, 1))
+		goto out_register_err;
+
+	if (inet_add_protocol(&udplite_protocol, IPPROTO_UDPLITE) < 0)
+		goto out_unregister_proto;
+
+	inet_register_protosw(&udplite4_protosw);
+
+	if (udplite4_proc_init())
+		printk(KERN_ERR "%s: Cannot register /proc!\n", __func__);
+	return;
+
+out_unregister_proto:
+	proto_unregister(&udplite_prot);
+out_register_err:
+	printk(KERN_CRIT "%s: Cannot add UDP-Lite protocol.\n", __func__);
+}
+
+EXPORT_SYMBOL(udplite_hash);
+EXPORT_SYMBOL(udplite_prot);
diff --git a/net/ipv4/xfrm4_input.c b/net/ipv4/xfrm4_input.c
new file mode 100644
index 0000000..390dcb1
--- /dev/null
+++ b/net/ipv4/xfrm4_input.c
@@ -0,0 +1,168 @@
+/*
+ * xfrm4_input.c
+ *
+ * Changes:
+ *	YOSHIFUJI Hideaki @USAGI
+ *		Split up af-specific portion
+ *	Derek Atkins <derek@ihtfp.com>
+ *		Add Encapsulation support
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+
+int xfrm4_extract_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	return xfrm4_extract_header(skb);
+}
+
+static inline int xfrm4_rcv_encap_finish(struct sk_buff *skb)
+{
+	if (skb->dst == NULL) {
+		const struct iphdr *iph = ip_hdr(skb);
+
+		if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos,
+				   skb->dev))
+			goto drop;
+	}
+	return dst_input(skb);
+drop:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
+		    int encap_type)
+{
+	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
+	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
+	return xfrm_input(skb, nexthdr, spi, encap_type);
+}
+EXPORT_SYMBOL(xfrm4_rcv_encap);
+
+int xfrm4_transport_finish(struct sk_buff *skb, int async)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
+
+#ifndef CONFIG_NETFILTER
+	if (!async)
+		return -iph->protocol;
+#endif
+
+	__skb_push(skb, skb->data - skb_network_header(skb));
+	iph->tot_len = htons(skb->len);
+	ip_send_check(iph);
+
+	NF_HOOK(PF_INET, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
+		xfrm4_rcv_encap_finish);
+	return 0;
+}
+
+/* If it's a keepalive packet, then just eat it.
+ * If it's an encapsulated packet, then pass it to the
+ * IPsec xfrm input.
+ * Returns 0 if skb passed to xfrm or was dropped.
+ * Returns >0 if skb should be passed to UDP.
+ * Returns <0 if skb should be resubmitted (-ret is protocol)
+ */
+int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct udp_sock *up = udp_sk(sk);
+	struct udphdr *uh;
+	struct iphdr *iph;
+	int iphlen, len;
+	int ret;
+
+	__u8 *udpdata;
+	__be32 *udpdata32;
+	__u16 encap_type = up->encap_type;
+
+	/* if this is not encapsulated socket, then just return now */
+	if (!encap_type)
+		return 1;
+
+	/* If this is a paged skb, make sure we pull up
+	 * whatever data we need to look at. */
+	len = skb->len - sizeof(struct udphdr);
+	if (!pskb_may_pull(skb, sizeof(struct udphdr) + min(len, 8)))
+		return 1;
+
+	/* Now we can get the pointers */
+	uh = udp_hdr(skb);
+	udpdata = (__u8 *)uh + sizeof(struct udphdr);
+	udpdata32 = (__be32 *)udpdata;
+
+	switch (encap_type) {
+	default:
+	case UDP_ENCAP_ESPINUDP:
+		/* Check if this is a keepalive packet.  If so, eat it. */
+		if (len == 1 && udpdata[0] == 0xff) {
+			goto drop;
+		} else if (len > sizeof(struct ip_esp_hdr) && udpdata32[0] != 0) {
+			/* ESP Packet without Non-ESP header */
+			len = sizeof(struct udphdr);
+		} else
+			/* Must be an IKE packet.. pass it through */
+			return 1;
+		break;
+	case UDP_ENCAP_ESPINUDP_NON_IKE:
+		/* Check if this is a keepalive packet.  If so, eat it. */
+		if (len == 1 && udpdata[0] == 0xff) {
+			goto drop;
+		} else if (len > 2 * sizeof(u32) + sizeof(struct ip_esp_hdr) &&
+			   udpdata32[0] == 0 && udpdata32[1] == 0) {
+
+			/* ESP Packet with Non-IKE marker */
+			len = sizeof(struct udphdr) + 2 * sizeof(u32);
+		} else
+			/* Must be an IKE packet.. pass it through */
+			return 1;
+		break;
+	}
+
+	/* At this point we are sure that this is an ESPinUDP packet,
+	 * so we need to remove 'len' bytes from the packet (the UDP
+	 * header and optional ESP marker bytes) and then modify the
+	 * protocol to ESP, and then call into the transform receiver.
+	 */
+	if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+		goto drop;
+
+	/* Now we can update and verify the packet length... */
+	iph = ip_hdr(skb);
+	iphlen = iph->ihl << 2;
+	iph->tot_len = htons(ntohs(iph->tot_len) - len);
+	if (skb->len < iphlen + len) {
+		/* packet is too small!?! */
+		goto drop;
+	}
+
+	/* pull the data buffer up to the ESP header and set the
+	 * transport header to point to ESP.  Keep UDP on the stack
+	 * for later.
+	 */
+	__skb_pull(skb, len);
+	skb_reset_transport_header(skb);
+
+	/* process ESP */
+	ret = xfrm4_rcv_encap(skb, IPPROTO_ESP, 0, encap_type);
+	return ret;
+
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+int xfrm4_rcv(struct sk_buff *skb)
+{
+	return xfrm4_rcv_spi(skb, ip_hdr(skb)->protocol, 0);
+}
+
+EXPORT_SYMBOL(xfrm4_rcv);
diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c
new file mode 100644
index 0000000..6341818
--- /dev/null
+++ b/net/ipv4/xfrm4_mode_beet.c
@@ -0,0 +1,159 @@
+/*
+ * xfrm4_mode_beet.c - BEET mode encapsulation for IPv4.
+ *
+ * Copyright (c) 2006 Diego Beltrami <diego.beltrami@gmail.com>
+ *                    Miika Komu     <miika@iki.fi>
+ *                    Herbert Xu     <herbert@gondor.apana.org.au>
+ *                    Abhinav Pathak <abhinav.pathak@hiit.fi>
+ *                    Jeff Ahrenholz <ahrenholz@gmail.com>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dst.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+
+static void xfrm4_beet_make_header(struct sk_buff *skb)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	iph->ihl = 5;
+	iph->version = 4;
+
+	iph->protocol = XFRM_MODE_SKB_CB(skb)->protocol;
+	iph->tos = XFRM_MODE_SKB_CB(skb)->tos;
+
+	iph->id = XFRM_MODE_SKB_CB(skb)->id;
+	iph->frag_off = XFRM_MODE_SKB_CB(skb)->frag_off;
+	iph->ttl = XFRM_MODE_SKB_CB(skb)->ttl;
+}
+
+/* Add encapsulation header.
+ *
+ * The top IP header will be constructed per draft-nikander-esp-beet-mode-06.txt.
+ */
+static int xfrm4_beet_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct ip_beet_phdr *ph;
+	struct iphdr *top_iph;
+	int hdrlen, optlen;
+
+	hdrlen = 0;
+	optlen = XFRM_MODE_SKB_CB(skb)->optlen;
+	if (unlikely(optlen))
+		hdrlen += IPV4_BEET_PHMAXLEN - (optlen & 4);
+
+	skb_set_network_header(skb, -x->props.header_len -
+			            hdrlen + (XFRM_MODE_SKB_CB(skb)->ihl - sizeof(*top_iph)));
+	if (x->sel.family != AF_INET6)
+		skb->network_header += IPV4_BEET_PHMAXLEN;
+	skb->mac_header = skb->network_header +
+			  offsetof(struct iphdr, protocol);
+	skb->transport_header = skb->network_header + sizeof(*top_iph);
+
+	xfrm4_beet_make_header(skb);
+
+	ph = (struct ip_beet_phdr *)
+		__skb_pull(skb, XFRM_MODE_SKB_CB(skb)->ihl - hdrlen);
+
+	top_iph = ip_hdr(skb);
+
+	if (unlikely(optlen)) {
+		BUG_ON(optlen < 0);
+
+		ph->padlen = 4 - (optlen & 4);
+		ph->hdrlen = optlen / 8;
+		ph->nexthdr = top_iph->protocol;
+		if (ph->padlen)
+			memset(ph + 1, IPOPT_NOP, ph->padlen);
+
+		top_iph->protocol = IPPROTO_BEETPH;
+		top_iph->ihl = sizeof(struct iphdr) / 4;
+	}
+
+	top_iph->saddr = x->props.saddr.a4;
+	top_iph->daddr = x->id.daddr.a4;
+
+	return 0;
+}
+
+static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	int optlen = 0;
+	int err = -EINVAL;
+
+	if (unlikely(XFRM_MODE_SKB_CB(skb)->protocol == IPPROTO_BEETPH)) {
+		struct ip_beet_phdr *ph;
+		int phlen;
+
+		if (!pskb_may_pull(skb, sizeof(*ph)))
+			goto out;
+
+		ph = (struct ip_beet_phdr *)skb->data;
+
+		phlen = sizeof(*ph) + ph->padlen;
+		optlen = ph->hdrlen * 8 + (IPV4_BEET_PHMAXLEN - phlen);
+		if (optlen < 0 || optlen & 3 || optlen > 250)
+			goto out;
+
+		XFRM_MODE_SKB_CB(skb)->protocol = ph->nexthdr;
+
+		if (!pskb_may_pull(skb, phlen))
+			goto out;
+		__skb_pull(skb, phlen);
+	}
+
+	skb_push(skb, sizeof(*iph));
+	skb_reset_network_header(skb);
+
+	memmove(skb->data - skb->mac_len, skb_mac_header(skb),
+		skb->mac_len);
+	skb_set_mac_header(skb, -skb->mac_len);
+
+	xfrm4_beet_make_header(skb);
+
+	iph = ip_hdr(skb);
+
+	iph->ihl += optlen / 4;
+	iph->tot_len = htons(skb->len);
+	iph->daddr = x->sel.daddr.a4;
+	iph->saddr = x->sel.saddr.a4;
+	iph->check = 0;
+	iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
+	err = 0;
+out:
+	return err;
+}
+
+static struct xfrm_mode xfrm4_beet_mode = {
+	.input2 = xfrm4_beet_input,
+	.input = xfrm_prepare_input,
+	.output2 = xfrm4_beet_output,
+	.output = xfrm4_prepare_output,
+	.owner = THIS_MODULE,
+	.encap = XFRM_MODE_BEET,
+	.flags = XFRM_MODE_FLAG_TUNNEL,
+};
+
+static int __init xfrm4_beet_init(void)
+{
+	return xfrm_register_mode(&xfrm4_beet_mode, AF_INET);
+}
+
+static void __exit xfrm4_beet_exit(void)
+{
+	int err;
+
+	err = xfrm_unregister_mode(&xfrm4_beet_mode, AF_INET);
+	BUG_ON(err);
+}
+
+module_init(xfrm4_beet_init);
+module_exit(xfrm4_beet_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_BEET);
diff --git a/net/ipv4/xfrm4_mode_transport.c b/net/ipv4/xfrm4_mode_transport.c
new file mode 100644
index 0000000..fd840c7
--- /dev/null
+++ b/net/ipv4/xfrm4_mode_transport.c
@@ -0,0 +1,80 @@
+/*
+ * xfrm4_mode_transport.c - Transport mode encapsulation for IPv4.
+ *
+ * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dst.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+
+/* Add encapsulation header.
+ *
+ * The IP header will be moved forward to make space for the encapsulation
+ * header.
+ */
+static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct iphdr *iph = ip_hdr(skb);
+	int ihl = iph->ihl * 4;
+
+	skb_set_network_header(skb, -x->props.header_len);
+	skb->mac_header = skb->network_header +
+			  offsetof(struct iphdr, protocol);
+	skb->transport_header = skb->network_header + ihl;
+	__skb_pull(skb, ihl);
+	memmove(skb_network_header(skb), iph, ihl);
+	return 0;
+}
+
+/* Remove encapsulation header.
+ *
+ * The IP header will be moved over the top of the encapsulation header.
+ *
+ * On entry, skb->h shall point to where the IP header should be and skb->nh
+ * shall be set to where the IP header currently is.  skb->data shall point
+ * to the start of the payload.
+ */
+static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int ihl = skb->data - skb_transport_header(skb);
+
+	if (skb->transport_header != skb->network_header) {
+		memmove(skb_transport_header(skb),
+			skb_network_header(skb), ihl);
+		skb->network_header = skb->transport_header;
+	}
+	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
+	skb_reset_transport_header(skb);
+	return 0;
+}
+
+static struct xfrm_mode xfrm4_transport_mode = {
+	.input = xfrm4_transport_input,
+	.output = xfrm4_transport_output,
+	.owner = THIS_MODULE,
+	.encap = XFRM_MODE_TRANSPORT,
+};
+
+static int __init xfrm4_transport_init(void)
+{
+	return xfrm_register_mode(&xfrm4_transport_mode, AF_INET);
+}
+
+static void __exit xfrm4_transport_exit(void)
+{
+	int err;
+
+	err = xfrm_unregister_mode(&xfrm4_transport_mode, AF_INET);
+	BUG_ON(err);
+}
+
+module_init(xfrm4_transport_init);
+module_exit(xfrm4_transport_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TRANSPORT);
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
new file mode 100644
index 0000000..7135279
--- /dev/null
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -0,0 +1,122 @@
+/*
+ * xfrm4_mode_tunnel.c - Tunnel mode encapsulation for IPv4.
+ *
+ * Copyright (c) 2004-2006 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/stringify.h>
+#include <net/dst.h>
+#include <net/inet_ecn.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+
+static inline void ipip_ecn_decapsulate(struct sk_buff *skb)
+{
+	struct iphdr *inner_iph = ipip_hdr(skb);
+
+	if (INET_ECN_is_ce(XFRM_MODE_SKB_CB(skb)->tos))
+		IP_ECN_set_ce(inner_iph);
+}
+
+/* Add encapsulation header.
+ *
+ * The top IP header will be constructed per RFC 2401.
+ */
+static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb->dst;
+	struct iphdr *top_iph;
+	int flags;
+
+	skb_set_network_header(skb, -x->props.header_len);
+	skb->mac_header = skb->network_header +
+			  offsetof(struct iphdr, protocol);
+	skb->transport_header = skb->network_header + sizeof(*top_iph);
+	top_iph = ip_hdr(skb);
+
+	top_iph->ihl = 5;
+	top_iph->version = 4;
+
+	top_iph->protocol = xfrm_af2proto(skb->dst->ops->family);
+
+	/* DS disclosed */
+	top_iph->tos = INET_ECN_encapsulate(XFRM_MODE_SKB_CB(skb)->tos,
+					    XFRM_MODE_SKB_CB(skb)->tos);
+
+	flags = x->props.flags;
+	if (flags & XFRM_STATE_NOECN)
+		IP_ECN_clear(top_iph);
+
+	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
+		0 : (XFRM_MODE_SKB_CB(skb)->frag_off & htons(IP_DF));
+	ip_select_ident(top_iph, dst->child, NULL);
+
+	top_iph->ttl = dst_metric(dst->child, RTAX_HOPLIMIT);
+
+	top_iph->saddr = x->props.saddr.a4;
+	top_iph->daddr = x->id.daddr.a4;
+
+	return 0;
+}
+
+static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+	const unsigned char *old_mac;
+	int err = -EINVAL;
+
+	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
+		goto out;
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto out;
+
+	if (skb_cloned(skb) &&
+	    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+		goto out;
+
+	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+		ipv4_copy_dscp(XFRM_MODE_SKB_CB(skb)->tos, ipip_hdr(skb));
+	if (!(x->props.flags & XFRM_STATE_NOECN))
+		ipip_ecn_decapsulate(skb);
+
+	old_mac = skb_mac_header(skb);
+	skb_set_mac_header(skb, -skb->mac_len);
+	memmove(skb_mac_header(skb), old_mac, skb->mac_len);
+	skb_reset_network_header(skb);
+	err = 0;
+
+out:
+	return err;
+}
+
+static struct xfrm_mode xfrm4_tunnel_mode = {
+	.input2 = xfrm4_mode_tunnel_input,
+	.input = xfrm_prepare_input,
+	.output2 = xfrm4_mode_tunnel_output,
+	.output = xfrm4_prepare_output,
+	.owner = THIS_MODULE,
+	.encap = XFRM_MODE_TUNNEL,
+	.flags = XFRM_MODE_FLAG_TUNNEL,
+};
+
+static int __init xfrm4_mode_tunnel_init(void)
+{
+	return xfrm_register_mode(&xfrm4_tunnel_mode, AF_INET);
+}
+
+static void __exit xfrm4_mode_tunnel_exit(void)
+{
+	int err;
+
+	err = xfrm_unregister_mode(&xfrm4_tunnel_mode, AF_INET);
+	BUG_ON(err);
+}
+
+module_init(xfrm4_mode_tunnel_init);
+module_exit(xfrm4_mode_tunnel_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_MODE(AF_INET, XFRM_MODE_TUNNEL);
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
new file mode 100644
index 0000000..8c3180a
--- /dev/null
+++ b/net/ipv4/xfrm4_output.c
@@ -0,0 +1,92 @@
+/*
+ * xfrm4_output.c - Common IPsec encapsulation code for IPv4.
+ * Copyright (c) 2004 Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/if_ether.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/dst.h>
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <net/icmp.h>
+
+static int xfrm4_tunnel_check_size(struct sk_buff *skb)
+{
+	int mtu, ret = 0;
+	struct dst_entry *dst;
+
+	if (IPCB(skb)->flags & IPSKB_XFRM_TUNNEL_SIZE)
+		goto out;
+
+	if (!(ip_hdr(skb)->frag_off & htons(IP_DF)) || skb->local_df)
+		goto out;
+
+	dst = skb->dst;
+	mtu = dst_mtu(dst);
+	if (skb->len > mtu) {
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+		ret = -EMSGSIZE;
+	}
+out:
+	return ret;
+}
+
+int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int err;
+
+	err = xfrm4_tunnel_check_size(skb);
+	if (err)
+		return err;
+
+	XFRM_MODE_SKB_CB(skb)->protocol = ip_hdr(skb)->protocol;
+
+	return xfrm4_extract_header(skb);
+}
+
+int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	int err;
+
+	err = xfrm_inner_extract_output(x, skb);
+	if (err)
+		return err;
+
+	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED;
+
+	skb->protocol = htons(ETH_P_IP);
+
+	return x->outer_mode->output2(x, skb);
+}
+EXPORT_SYMBOL(xfrm4_prepare_output);
+
+static int xfrm4_output_finish(struct sk_buff *skb)
+{
+#ifdef CONFIG_NETFILTER
+	if (!skb->dst->xfrm) {
+		IPCB(skb)->flags |= IPSKB_REROUTED;
+		return dst_output(skb);
+	}
+
+	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
+#endif
+
+	skb->protocol = htons(ETH_P_IP);
+	return xfrm_output(skb);
+}
+
+int xfrm4_output(struct sk_buff *skb)
+{
+	return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb,
+			    NULL, skb->dst->dev, xfrm4_output_finish,
+			    !(IPCB(skb)->flags & IPSKB_REROUTED));
+}
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
new file mode 100644
index 0000000..c63de0a
--- /dev/null
+++ b/net/ipv4/xfrm4_policy.c
@@ -0,0 +1,280 @@
+/*
+ * xfrm4_policy.c
+ *
+ * Changes:
+ *	Kazunori MIYAZAWA @USAGI
+ * 	YOSHIFUJI Hideaki @USAGI
+ *		Split up af-specific portion
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/inetdevice.h>
+#include <net/dst.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+
+static struct dst_ops xfrm4_dst_ops;
+static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
+
+static struct dst_entry *xfrm4_dst_lookup(int tos, xfrm_address_t *saddr,
+					  xfrm_address_t *daddr)
+{
+	struct flowi fl = {
+		.nl_u = {
+			.ip4_u = {
+				.tos = tos,
+				.daddr = daddr->a4,
+			},
+		},
+	};
+	struct dst_entry *dst;
+	struct rtable *rt;
+	int err;
+
+	if (saddr)
+		fl.fl4_src = saddr->a4;
+
+	err = __ip_route_output_key(&init_net, &rt, &fl);
+	dst = &rt->u.dst;
+	if (err)
+		dst = ERR_PTR(err);
+	return dst;
+}
+
+static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
+{
+	struct dst_entry *dst;
+	struct rtable *rt;
+
+	dst = xfrm4_dst_lookup(0, NULL, daddr);
+	if (IS_ERR(dst))
+		return -EHOSTUNREACH;
+
+	rt = (struct rtable *)dst;
+	saddr->a4 = rt->rt_src;
+	dst_release(dst);
+	return 0;
+}
+
+static struct dst_entry *
+__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
+{
+	struct dst_entry *dst;
+
+	read_lock_bh(&policy->lock);
+	for (dst = policy->bundles; dst; dst = dst->next) {
+		struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
+		if (xdst->u.rt.fl.oif == fl->oif &&	/*XXX*/
+		    xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
+		    xdst->u.rt.fl.fl4_src == fl->fl4_src &&
+		    xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
+		    xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
+			dst_clone(dst);
+			break;
+		}
+	}
+	read_unlock_bh(&policy->lock);
+	return dst;
+}
+
+static int xfrm4_get_tos(struct flowi *fl)
+{
+	return fl->fl4_tos;
+}
+
+static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
+			   int nfheader_len)
+{
+	return 0;
+}
+
+static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
+{
+	struct rtable *rt = (struct rtable *)xdst->route;
+
+	xdst->u.rt.fl = rt->fl;
+
+	xdst->u.dst.dev = dev;
+	dev_hold(dev);
+
+	xdst->u.rt.idev = in_dev_get(dev);
+	if (!xdst->u.rt.idev)
+		return -ENODEV;
+
+	xdst->u.rt.peer = rt->peer;
+	if (rt->peer)
+		atomic_inc(&rt->peer->refcnt);
+
+	/* Sheit... I remember I did this right. Apparently,
+	 * it was magically lost, so this code needs audit */
+	xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
+					      RTCF_LOCAL);
+	xdst->u.rt.rt_type = rt->rt_type;
+	xdst->u.rt.rt_src = rt->rt_src;
+	xdst->u.rt.rt_dst = rt->rt_dst;
+	xdst->u.rt.rt_gateway = rt->rt_gateway;
+	xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
+
+	return 0;
+}
+
+static void
+_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
+{
+	struct iphdr *iph = ip_hdr(skb);
+	u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
+
+	memset(fl, 0, sizeof(struct flowi));
+	if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
+		switch (iph->protocol) {
+		case IPPROTO_UDP:
+		case IPPROTO_UDPLITE:
+		case IPPROTO_TCP:
+		case IPPROTO_SCTP:
+		case IPPROTO_DCCP:
+			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
+				__be16 *ports = (__be16 *)xprth;
+
+				fl->fl_ip_sport = ports[!!reverse];
+				fl->fl_ip_dport = ports[!reverse];
+			}
+			break;
+
+		case IPPROTO_ICMP:
+			if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
+				u8 *icmp = xprth;
+
+				fl->fl_icmp_type = icmp[0];
+				fl->fl_icmp_code = icmp[1];
+			}
+			break;
+
+		case IPPROTO_ESP:
+			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
+				__be32 *ehdr = (__be32 *)xprth;
+
+				fl->fl_ipsec_spi = ehdr[0];
+			}
+			break;
+
+		case IPPROTO_AH:
+			if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
+				__be32 *ah_hdr = (__be32*)xprth;
+
+				fl->fl_ipsec_spi = ah_hdr[1];
+			}
+			break;
+
+		case IPPROTO_COMP:
+			if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
+				__be16 *ipcomp_hdr = (__be16 *)xprth;
+
+				fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
+			}
+			break;
+		default:
+			fl->fl_ipsec_spi = 0;
+			break;
+		}
+	}
+	fl->proto = iph->protocol;
+	fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
+	fl->fl4_src = reverse ? iph->daddr : iph->saddr;
+	fl->fl4_tos = iph->tos;
+}
+
+static inline int xfrm4_garbage_collect(struct dst_ops *ops)
+{
+	xfrm4_policy_afinfo.garbage_collect();
+	return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
+}
+
+static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
+{
+	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+	struct dst_entry *path = xdst->route;
+
+	path->ops->update_pmtu(path, mtu);
+}
+
+static void xfrm4_dst_destroy(struct dst_entry *dst)
+{
+	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+
+	if (likely(xdst->u.rt.idev))
+		in_dev_put(xdst->u.rt.idev);
+	if (likely(xdst->u.rt.peer))
+		inet_putpeer(xdst->u.rt.peer);
+	xfrm_dst_destroy(xdst);
+}
+
+static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			     int unregister)
+{
+	struct xfrm_dst *xdst;
+
+	if (!unregister)
+		return;
+
+	xdst = (struct xfrm_dst *)dst;
+	if (xdst->u.rt.idev->dev == dev) {
+		struct in_device *loopback_idev =
+			in_dev_get(dev_net(dev)->loopback_dev);
+		BUG_ON(!loopback_idev);
+
+		do {
+			in_dev_put(xdst->u.rt.idev);
+			xdst->u.rt.idev = loopback_idev;
+			in_dev_hold(loopback_idev);
+			xdst = (struct xfrm_dst *)xdst->u.dst.child;
+		} while (xdst->u.dst.xfrm);
+
+		__in_dev_put(loopback_idev);
+	}
+
+	xfrm_dst_ifdown(dst, dev);
+}
+
+static struct dst_ops xfrm4_dst_ops = {
+	.family =		AF_INET,
+	.protocol =		__constant_htons(ETH_P_IP),
+	.gc =			xfrm4_garbage_collect,
+	.update_pmtu =		xfrm4_update_pmtu,
+	.destroy =		xfrm4_dst_destroy,
+	.ifdown =		xfrm4_dst_ifdown,
+	.local_out =		__ip_local_out,
+	.gc_thresh =		1024,
+	.entry_size =		sizeof(struct xfrm_dst),
+	.entries =		ATOMIC_INIT(0),
+};
+
+static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
+	.family = 		AF_INET,
+	.dst_ops =		&xfrm4_dst_ops,
+	.dst_lookup =		xfrm4_dst_lookup,
+	.get_saddr =		xfrm4_get_saddr,
+	.find_bundle = 		__xfrm4_find_bundle,
+	.decode_session =	_decode_session4,
+	.get_tos =		xfrm4_get_tos,
+	.init_path =		xfrm4_init_path,
+	.fill_dst =		xfrm4_fill_dst,
+};
+
+static void __init xfrm4_policy_init(void)
+{
+	xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
+}
+
+static void __exit xfrm4_policy_fini(void)
+{
+	xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
+}
+
+void __init xfrm4_init(void)
+{
+	xfrm4_state_init();
+	xfrm4_policy_init();
+}
+
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
new file mode 100644
index 0000000..55dc6be
--- /dev/null
+++ b/net/ipv4/xfrm4_state.c
@@ -0,0 +1,92 @@
+/*
+ * xfrm4_state.c
+ *
+ * Changes:
+ * 	YOSHIFUJI Hideaki @USAGI
+ * 		Split up af-specific portion
+ *
+ */
+
+#include <net/ip.h>
+#include <net/xfrm.h>
+#include <linux/pfkeyv2.h>
+#include <linux/ipsec.h>
+#include <linux/netfilter_ipv4.h>
+
+static struct xfrm_state_afinfo xfrm4_state_afinfo;
+
+static int xfrm4_init_flags(struct xfrm_state *x)
+{
+	if (ipv4_config.no_pmtu_disc)
+		x->props.flags |= XFRM_STATE_NOPMTUDISC;
+	return 0;
+}
+
+static void
+__xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
+		     struct xfrm_tmpl *tmpl,
+		     xfrm_address_t *daddr, xfrm_address_t *saddr)
+{
+	x->sel.daddr.a4 = fl->fl4_dst;
+	x->sel.saddr.a4 = fl->fl4_src;
+	x->sel.dport = xfrm_flowi_dport(fl);
+	x->sel.dport_mask = htons(0xffff);
+	x->sel.sport = xfrm_flowi_sport(fl);
+	x->sel.sport_mask = htons(0xffff);
+	x->sel.family = AF_INET;
+	x->sel.prefixlen_d = 32;
+	x->sel.prefixlen_s = 32;
+	x->sel.proto = fl->proto;
+	x->sel.ifindex = fl->oif;
+	x->id = tmpl->id;
+	if (x->id.daddr.a4 == 0)
+		x->id.daddr.a4 = daddr->a4;
+	x->props.saddr = tmpl->saddr;
+	if (x->props.saddr.a4 == 0)
+		x->props.saddr.a4 = saddr->a4;
+	x->props.mode = tmpl->mode;
+	x->props.reqid = tmpl->reqid;
+	x->props.family = AF_INET;
+}
+
+int xfrm4_extract_header(struct sk_buff *skb)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	XFRM_MODE_SKB_CB(skb)->ihl = sizeof(*iph);
+	XFRM_MODE_SKB_CB(skb)->id = iph->id;
+	XFRM_MODE_SKB_CB(skb)->frag_off = iph->frag_off;
+	XFRM_MODE_SKB_CB(skb)->tos = iph->tos;
+	XFRM_MODE_SKB_CB(skb)->ttl = iph->ttl;
+	XFRM_MODE_SKB_CB(skb)->optlen = iph->ihl * 4 - sizeof(*iph);
+	memset(XFRM_MODE_SKB_CB(skb)->flow_lbl, 0,
+	       sizeof(XFRM_MODE_SKB_CB(skb)->flow_lbl));
+
+	return 0;
+}
+
+static struct xfrm_state_afinfo xfrm4_state_afinfo = {
+	.family			= AF_INET,
+	.proto			= IPPROTO_IPIP,
+	.eth_proto		= htons(ETH_P_IP),
+	.owner			= THIS_MODULE,
+	.init_flags		= xfrm4_init_flags,
+	.init_tempsel		= __xfrm4_init_tempsel,
+	.output			= xfrm4_output,
+	.extract_input		= xfrm4_extract_input,
+	.extract_output		= xfrm4_extract_output,
+	.transport_finish	= xfrm4_transport_finish,
+};
+
+void __init xfrm4_state_init(void)
+{
+	xfrm_state_register_afinfo(&xfrm4_state_afinfo);
+}
+
+#if 0
+void __exit xfrm4_state_fini(void)
+{
+	xfrm_state_unregister_afinfo(&xfrm4_state_afinfo);
+}
+#endif  /*  0  */
+
diff --git a/net/ipv4/xfrm4_tunnel.c b/net/ipv4/xfrm4_tunnel.c
new file mode 100644
index 0000000..41f5982
--- /dev/null
+++ b/net/ipv4/xfrm4_tunnel.c
@@ -0,0 +1,113 @@
+/* xfrm4_tunnel.c: Generic IP tunnel transformer.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+
+static int ipip_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+	skb_push(skb, -skb_network_offset(skb));
+	return 0;
+}
+
+static int ipip_xfrm_rcv(struct xfrm_state *x, struct sk_buff *skb)
+{
+	return ip_hdr(skb)->protocol;
+}
+
+static int ipip_init_state(struct xfrm_state *x)
+{
+	if (x->props.mode != XFRM_MODE_TUNNEL)
+		return -EINVAL;
+
+	if (x->encap)
+		return -EINVAL;
+
+	x->props.header_len = sizeof(struct iphdr);
+
+	return 0;
+}
+
+static void ipip_destroy(struct xfrm_state *x)
+{
+}
+
+static const struct xfrm_type ipip_type = {
+	.description	= "IPIP",
+	.owner		= THIS_MODULE,
+	.proto	     	= IPPROTO_IPIP,
+	.init_state	= ipip_init_state,
+	.destructor	= ipip_destroy,
+	.input		= ipip_xfrm_rcv,
+	.output		= ipip_output
+};
+
+static int xfrm_tunnel_rcv(struct sk_buff *skb)
+{
+	return xfrm4_rcv_spi(skb, IPPROTO_IPIP, ip_hdr(skb)->saddr);
+}
+
+static int xfrm_tunnel_err(struct sk_buff *skb, u32 info)
+{
+	return -ENOENT;
+}
+
+static struct xfrm_tunnel xfrm_tunnel_handler = {
+	.handler	=	xfrm_tunnel_rcv,
+	.err_handler	=	xfrm_tunnel_err,
+	.priority	=	2,
+};
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static struct xfrm_tunnel xfrm64_tunnel_handler = {
+	.handler	=	xfrm_tunnel_rcv,
+	.err_handler	=	xfrm_tunnel_err,
+	.priority	=	2,
+};
+#endif
+
+static int __init ipip_init(void)
+{
+	if (xfrm_register_type(&ipip_type, AF_INET) < 0) {
+		printk(KERN_INFO "ipip init: can't add xfrm type\n");
+		return -EAGAIN;
+	}
+
+	if (xfrm4_tunnel_register(&xfrm_tunnel_handler, AF_INET)) {
+		printk(KERN_INFO "ipip init: can't add xfrm handler for AF_INET\n");
+		xfrm_unregister_type(&ipip_type, AF_INET);
+		return -EAGAIN;
+	}
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	if (xfrm4_tunnel_register(&xfrm64_tunnel_handler, AF_INET6)) {
+		printk(KERN_INFO "ipip init: can't add xfrm handler for AF_INET6\n");
+		xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET);
+		xfrm_unregister_type(&ipip_type, AF_INET);
+		return -EAGAIN;
+	}
+#endif
+	return 0;
+}
+
+static void __exit ipip_fini(void)
+{
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+	if (xfrm4_tunnel_deregister(&xfrm64_tunnel_handler, AF_INET6))
+		printk(KERN_INFO "ipip close: can't remove xfrm handler for AF_INET6\n");
+#endif
+	if (xfrm4_tunnel_deregister(&xfrm_tunnel_handler, AF_INET))
+		printk(KERN_INFO "ipip close: can't remove xfrm handler for AF_INET\n");
+	if (xfrm_unregister_type(&ipip_type, AF_INET) < 0)
+		printk(KERN_INFO "ipip close: can't remove xfrm type\n");
+}
+
+module_init(ipip_init);
+module_exit(ipip_fini);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_IPIP);