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* Permit buiding kernels with options VIMAGE, restricted to only a singlezec2009-04-301-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | active network stack instance. Turning on options VIMAGE at compile time yields the following changes relative to default kernel build: 1) V_ accessor macros for virtualized variables resolve to structure fields via base pointers, instead of being resolved as fields in global structs or plain global variables. As an example, V_ifnet becomes: options VIMAGE: ((struct vnet_net *) vnet_net)->_ifnet default build: vnet_net_0._ifnet options VIMAGE_GLOBALS: ifnet 2) INIT_VNET_* macros will declare and set up base pointers to be used by V_ accessor macros, instead of resolving to whitespace: INIT_VNET_NET(ifp->if_vnet); becomes struct vnet_net *vnet_net = (ifp->if_vnet)->mod_data[VNET_MOD_NET]; 3) Memory for vnet modules registered via vnet_mod_register() is now allocated at run time in sys/kern/kern_vimage.c, instead of per vnet module structs being declared as globals. If required, vnet modules can now request the framework to provide them with allocated bzeroed memory by filling in the vmi_size field in their vmi_modinfo structures. 4) structs socket, ifnet, inpcbinfo, tcpcb and syncache_head are extended to hold a pointer to the parent vnet. options VIMAGE builds will fill in those fields as required. 5) curvnet is introduced as a new global variable in options VIMAGE builds, always pointing to the default and only struct vnet. 6) struct sysctl_oid has been extended with additional two fields to store major and minor virtualization module identifiers, oid_v_subs and oid_v_mod. SYSCTL_V_* family of macros will fill in those fields accordingly, and store the offset in the appropriate vnet container struct in oid_arg1. In sysctl handlers dealing with virtualized sysctls, the SYSCTL_RESOLVE_V_ARG1() macro will compute the address of the target variable and make it available in arg1 variable for further processing. Unused fields in structs vnet_inet, vnet_inet6 and vnet_ipfw have been deleted. Reviewed by: bz, rwatson Approved by: julian (mentor)
* Put TCPSTAT_ADD() and TCPSTAT_INC() behind _KERNEL.rwatson2009-04-121-0/+2
| | | | MFC after: 3 days
* Update stats in struct tcpstat using two new macros, TCPSTAT_ADD() andrwatson2009-04-111-0/+3
| | | | | | | | TCPSTAT_INC(), rather than directly manipulating the fields across the kernel. This will make it easier to change the implementation of these statistics, such as using per-CPU versions of the data structures. MFC after: 3 days
* Add externs to fix build with VIMAGE_GLOBALS after r187289.bz2009-01-221-0/+2
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* Add TCP Appropriate Byte Counting (RFC 3465) support to kernel.lstewart2009-01-151-0/+1
| | | | | | | | | | | | | The new behaviour is on by default, and can be disabled by setting the net.inet.tcp.rfc3465 sysctl to 0 to obtain previous behaviour. The patch changes struct tcpcb in sys/netinet/tcp_var.h which breaks the ABI. Bump __FreeBSD_version to 800061 accordingly. User space tools that rely on the size of struct tcpcb (e.g. sockstat) need to be recompiled. Reviewed by: rpaulo, gnn Approved by: gnn, kmacy (mentors) Sponsored by: FreeBSD Foundation
* Second round of putting global variables, which were virtualizedbz2008-12-131-0/+4
| | | | | | | | | | | but formerly missed under VIMAGE_GLOBAL. Put the extern declarations of the virtualized globals under VIMAGE_GLOBAL as the globals themsevles are already. This will help by the time when we are going to remove the globals entirely. Sponsored by: The FreeBSD Foundation
* Put a global variables, which were virtualized but formerlybz2008-12-111-1/+4
| | | | | | | | | | | | | missed under VIMAGE_GLOBAL. Start putting the extern declarations of the virtualized globals under VIMAGE_GLOBAL as the globals themsevles are already. This will help by the time when we are going to remove the globals entirely. While there garbage collect a few dead externs from ip6_var.h. Sponsored by: The FreeBSD Foundation
* Move flag definitions for t_flags and t_oobflags below the definition ofrwatson2008-12-101-28/+36
| | | | | | | struct tcpcb so that the structure definition is a bit more vertically compact. Can't yet fit it on one printed page, though. MFC after: pretty soon
* Change the initialization methodology for global variables scheduledzec2008-11-191-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | for virtualization. Instead of initializing the affected global variables at instatiation, assign initial values to them in initializer functions. As a rule, initialization at instatiation for such variables should never be introduced again from now on. Furthermore, enclose all instantiations of such global variables in #ifdef VIMAGE_GLOBALS blocks. Essentialy, this change should have zero functional impact. In the next phase of merging network stack virtualization infrastructure from p4/vimage branch, the new initialization methology will allow us to switch between using global variables and their counterparts residing in virtualization containers with minimum code churn, and in the long run allow us to intialize multiple instances of such container structures. Discussed at: devsummit Strassburg Reviewed by: bz, julian Approved by: julian (mentor) Obtained from: //depot/projects/vimage-commit2/... X-MFC after: never Sponsored by: NLnet Foundation, The FreeBSD Foundation
* Fix a bug introduced with r182851 splitting tcp_mss() intobz2008-11-061-1/+1
| | | | | | | | | | | | | | | | | | tcp_mss() and tcp_mss_update() so that tcp_mtudisc() could re-use the same code. Move the TSO logic back to tcp_mss() and out of tcp_mss_update(). We tried to avoid that initially but if were are called from tcp_output() with EMSGSIZE, we cleared the TSO flag on the tcpcb there, called into tcp_mtudisc() and tcp_mss_update() which then would reenable TSO on the tcpcb based on TSO capabilities of the interface as learnt in tcp_maxmtu/6(). So if TSO was enabled on the (possibly new) outgoing interface it was turned back on, which lead to an endless loop between tcp_output() and tcp_mtudisc() until we overflew the stack. Reported by: kmacy MFC after: 2 months (along with r182851)
* Split tcp_mss() in tcp_mss() and tcp_mss_update() where the formerbz2008-09-071-0/+1
| | | | | | | | | | | | | | | calls the latter. Merge tcp_mss_update() with code from tcp_mtudisc() basically doing the same thing. This gives us one central place where we calcuate and check mss values to update t_maxopd (maximum mss + options length) instead of two slightly different but almost equal implementations to maintain. PR: kern/118455 Reviewed by: silby (back in March) MFC after: 2 months
* MFp4 (//depot/projects/tcpecn/):rpaulo2008-07-311-0/+12
| | | | | | | | TCP ECN support. Merge of my GSoC 2006 work for NetBSD. TCP ECN is defined in RFC 3168. Partly reviewed by: dwmalone, silby Obtained from: NetBSD
* Revert to rev. 1.161 - switch back to optimized TCP options ordering.bz2008-04-201-5/+2
| | | | | | | | | | | | A lot of testing has shown that the problem people were seeing was due to invalid padding after the end of option list option, which was corrected in tcp_output.c rev. 1.146. Thanks to: anders@, s3raphi, Matt Reimer Thanks to: Doug Hardie and Randy Rose, John Mayer, Susan Guzzardi Special thanks to: dwhite@ and BitGravity Discussed with: silby MFC after: 1 day
* Change FreeBSD 7 so that it returns TCP options insilby2008-02-241-2/+5
| | | | | | | | | | | | | | | | | | | | | | the same order that FreeBSD 6 and before did. Doug White and the other bloodhounds at ISC discovered that while FreeBSD 7's ordering of options was more efficient, it caused some cable modem routers to ignore the SYN-ACKs ordered in this fashion. The placement of sackOK after the timestamp option seems to be the critical difference: FreeBSD 6: <mss 1460,nop,wscale 1,nop,nop,timestamp 3512155768 0,sackOK,eol> FreeBSD 7.0: <mss 1460,nop,wscale 3,sackOK,timestamp 1370692577 0> FreeBSD 7.0 + this change: <mss 1460,nop,wscale 3,nop,nop,timestamp 7371813 0,sackOK,eol> MFC after: 1 week
* Fix style issues with initial TCP offload commitkmacy2007-12-121-1/+1
| | | | | Requested by: rwatson Submitted by: rwatson
* Add driver independent interface to offload active established TCP connectionskmacy2007-12-121-1/+4
| | | | Reviewed by: silby
* Add padding for anticipated functionalitykmacy2007-12-071-0/+1
| | | | | | | | | | | | - vimage - TOE - multiq - host rtentry caching Rename spare used by 80211 to if_llsoftc Reviewed by: rwatson, gnn MFC after: 1 day
* Two changes:silby2007-09-241-5/+1
| | | | | | | | | | | | | | | | | | - Reintegrate the ANSI C function declaration change from tcp_timer.c rev 1.92 - Reorganize the tcpcb structure so that it has a single pointer to the "tcp_timer" structure which contains all of the tcp timer callouts. This change means that when the single tcp timer change is reintegrated, tcpcb will not change in size, and therefore the ABI between netstat and the kernel will not change. Neither of these changes should have any functional impact. Reviewed by: bmah, rrs Approved by: re (bmah)
* Back out tcp_timer.c:1.93 and associated changes that reimplemented the manyrwatson2007-09-071-1/+5
| | | | | | | | | | | | | | | | | | | | | | | TCP timers as a single timer, but retain the API changes necessary to reintroduce this change. This will back out the source of at least two reported problems: lock leaks in certain timer edge cases, and TCP timers continuing to fire after a connection has closed (a bug previously fixed and then reintroduced with the timer rewrite). In a follow-up commit, some minor restylings and comment changes performed after the TCP timer rewrite will be reapplied, and a further change to allow the TCP timer rewrite to be added back without disturbing the ABI. The new design is believed to be a good thing, but the outstanding issues are leading to significant stability/correctness problems that are holding up 7.0. This patch was generated by silby, but is being committed by proxy due to poor network connectivity for silby this week. Approved by: re (kensmith) Submitted by: silby Tested by: rwatson, kris Problems reported by: peter, kris, others
* Provide a sysctl to toggle reporting of TCP debug logging:andre2007-07-281-0/+1
| | | | | | | | | | | | | | | | | | | | | sys.net.inet.tcp.log_debug = 1 It defaults to enabled for the moment and is to be turned off for the next release like other diagnostics from development branches. It is important to note that sysctl sys.net.inet.tcp.log_in_vain uses the same logging function as log_debug. Enabling of the former also causes the latter to engage, but not vice versa. Use consistent terminology in tcp log messages: "ignored" means a segment contains invalid flags/information and is dropped without changing state or issuing a reply. "rejected" means a segments contains invalid flags/information but is causing a reply (usually RST) and may cause a state change. Approved by: re (rwatson)
* Export the contents of the syncache to netstat.silby2007-07-271-8/+0
| | | | | Approved by: re (kensmith) MFC after: 2 weeks
* Fix cast-qualifiers warning when INET6 is not presentpeter2007-07-051-1/+1
| | | | Approved by: re (rwatson)
* Refactor and rewrite in parts the SYN handling code on listen socketsandre2007-05-281-1/+2
| | | | | | | | | | | | | | | | | | | | | in tcp_input(): o tighten the checks on allowed TCP flags to be RFC793 and tcp-secure conform o log check failures to syslog at LOG_DEBUG level o rearrange the code flow to be easier to follow o add KASSERTs to validate assumptions of the code flow Add sysctl net.inet.tcp.syncache.rst_on_sock_fail defaulting to enable that controls the behavior on socket creation failure for a otherwise successful 3-way handshake. The socket creation can fail due to global memory shortage, listen queue limits and file descriptor limits. The sysctl allows to chose between two options to deal with this. One is to send a reset to the other endpoint to notify it about the failure (default). The other one is to ignore and treat the failure as a transient error and have the other endpoint retransmit for another try. Reviewed by: rwatson (in general)
* Add tcp_log_addrs() function to generate and standardized TCP log lineandre2007-05-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | for use thoughout the tcp subsystem. It is IPv4 and IPv6 aware creates a line in the following format: "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags <RST>" A "\n" is not included at the end. The caller is supposed to add further information after the standard tcp log header. The function returns a NUL terminated string which the caller has to free(s, M_TCPLOG) after use. All memory allocation is done with M_NOWAIT and the return value may be NULL in memory shortage situations. Either struct in_conninfo || (struct tcphdr && (struct ip || struct ip6_hdr) have to be supplied. Due to ip[6].h header inclusion limitations and ordering issues the struct ip and struct ip6_hdr parameters have to be casted and passed as void * pointers. tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, void *ip6hdr) Usage example: struct ip *ip; char *tcplog; if (tcplog = tcp_log_addrs(NULL, th, (void *)ip, NULL)) { log(LOG_DEBUG, "%s; %s: Connection attempt to closed port\n", tcplog, __func__); free(s, M_TCPLOG); }
* Move TIME_WAIT related functions and timer handling from filesandre2007-05-161-0/+2
| | | | | | | | | | | | | | | | other than repo copied tcp_subr.c into tcp_timewait.c#1.284: tcp_input.c#1.350 tcp_timewait() -> tcp_twcheck() tcp_timer.c#1.92 tcp_timer_2msl_reset() -> tcp_tw_2msl_reset() tcp_timer.c#1.92 tcp_timer_2msl_stop() -> tcp_tw_2msl_stop() tcp_timer.c#1.92 tcp_timer_2msl_tw() -> tcp_tw_2msl_scan() This is a mechanical move with appropriate renames and making them static if used only locally. The tcp_tw_2msl_scan() cleanup function is still run from the tcp_slowtimo() in tcp_timer.c.
* Complete the (mechanical) move of the TCP reassembly and timewaitandre2007-05-131-0/+15
| | | | | | | functions from their origininal place to their own files. TCP Reassembly from tcp_input.c -> tcp_reass.c TCP Timewait from tcp_subr.c -> tcp_timewait.c
* Add the timestamp offset to struct tcptw so we can generate properandre2007-05-111-0/+1
| | | | | ACKs in TIME_WAIT state that don't get dropped by the PAWS check on the receiver.
* Remove unused requested_s_scale from struct tcpcb.andre2007-05-061-1/+0
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* Use existing TF_SACK_PERMIT flag in struct tcpcb t_flags field instead ofandre2007-05-061-1/+0
| | | | a decdicated sack_enable int for this bool. Change all users accordingly.
* Add global mutex tcp_debug_mtx, which will protect global TCP debuggingrwatson2007-05-041-1/+1
| | | | | | | | | | | state tcp_debug, tcp_debx. Acquire and drop as required in tcp_trace(). Move to ANSI C function header, correct prototype types so that short TCP state is no longer promoted to int unnecessarily. Add comments. MFC after: 3 weeks
* o Remove unncessary TOF_SIGLEN flag from struct tcpoptandre2007-04-201-6/+5
| | | | | o Correctly set to->to_signature in tcp_dooptions() o Update comments
* Remove bogus check for accept queue length and associated failure handlingandre2007-04-201-1/+1
| | | | | | | | | | | | | | from the incoming SYN handling section of tcp_input(). Enforcement of the accept queue limits is done by sonewconn() after the 3WHS is completed. It is not necessary to have an earlier check before a connection request enters the SYN cache awaiting the full handshake. It rather limits the effectiveness of the syncache by preventing legit and illegit connections from entering it and having them shaken out before we hit the real limit which may have vanished by then. Change return value of syncache_add() to void. No status communication is required.
* Change the TCP timer system from using the callout system five timesandre2007-04-111-7/+3
| | | | | | | | | | | | | | | | directly to a merged model where only one callout, the next to fire, is registered. Instead of callout_reset(9) and callout_stop(9) the new function tcp_timer_activate() is used which then internally manages the callout. The single new callout is a mutex callout on inpcb simplifying the locking a bit. tcp_timer() is the called function which handles all race conditions in one place and then dispatches the individual timer functions. Reviewed by: rwatson (earlier version)
* Remove tcp_minmssoverload DoS detection logic. The problem it tried toandre2007-03-211-5/+0
| | | | | | protect us from wasn't really there and it only bloats the code. Should the problem surface in the future we can simply resurrect it from cvs history.
* Consolidate insertion of TCP options into a segment from within tcp_output()andre2007-03-151-8/+14
| | | | | | | | | | | | | | and syncache_respond() into its own generic function tcp_addoptions(). tcp_addoptions() is alignment agnostic and does optimal packing in all cases. In struct tcpopt rename to_requested_s_scale to just to_wscale. Add a comment with quote from RFC1323: "The Window field in a SYN (i.e., a <SYN> or <SYN,ACK>) segment itself is never scaled." Reviewed by: silby, mohans, julian Sponsored by: TCP/IP Optimization Fundraise 2005
* Reap FIN_WAIT_2 connections marked SOCANTRCVMORE faster. This mitigatemohans2007-02-261-0/+3
| | | | | | | | potential issues where the peer does not close, potentially leaving thousands of connections in FIN_WAIT_2. This is controlled by a new sysctl fast_finwait2_recycle, which is disabled by default. Reviewed by: gnn, silby.
* Auto sizing TCP socket buffers.andre2007-02-011-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally the socket buffers are static (either derived from global defaults or set with setsockopt) and do not adapt to real network conditions. Two things happen: a) your socket buffers are too small and you can't reach the full potential of the network between both hosts; b) your socket buffers are too big and you waste a lot of kernel memory for data just sitting around. With automatic TCP send and receive socket buffers we can start with a small buffer and quickly grow it in parallel with the TCP congestion window to match real network conditions. FreeBSD has a default 32K send socket buffer. This supports a maximal transfer rate of only slightly more than 2Mbit/s on a 100ms RTT trans-continental link. Or at 200ms just above 1Mbit/s. With TCP send buffer auto scaling and the default values below it supports 20Mbit/s at 100ms and 10Mbit/s at 200ms. That's an improvement of factor 10, or 1000%. For the receive side it looks slightly better with a default of 64K buffer size. New sysctls are: net.inet.tcp.sendbuf_auto=1 (enabled) net.inet.tcp.sendbuf_inc=8192 (8K, step size) net.inet.tcp.sendbuf_max=262144 (256K, growth limit) net.inet.tcp.recvbuf_auto=1 (enabled) net.inet.tcp.recvbuf_inc=16384 (16K, step size) net.inet.tcp.recvbuf_max=262144 (256K, growth limit) Tested by: many (on HEAD and RELENG_6) Approved by: re MFC after: 1 month
* Rewrite of TCP syncookies to remove locking requirements and to enhanceandre2006-09-131-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | functionality: - Remove a rwlock aquisition/release per generated syncookie. Locking is now integrated with the bucket row locking of syncache itself and syncookies no longer add any additional lock overhead. - Syncookie secrets are different for and stored per syncache buck row. Secrets expire after 16 seconds and are reseeded on-demand. - The computational overhead for syncookie generation and verification is one MD5 hash computation as before. - Syncache can be turned off and run with syncookies only by setting the sysctl net.inet.tcp.syncookies_only=1. This implementation extends the orginal idea and first implementation of FreeBSD by using not only the initial sequence number field to store information but also the timestamp field if present. This way we can keep track of the entire state we need to know to recreate the session in its original form. Almost all TCP speakers implement RFC1323 timestamps these days. For those that do not we still have to live with the known shortcomings of the ISN only SYN cookies. The use of the timestamp field causes the timestamps to be randomized if syncookies are enabled. The idea of SYN cookies is to encode and include all necessary information about the connection setup state within the SYN-ACK we send back and thus to get along without keeping any local state until the ACK to the SYN-ACK arrives (if ever). Everything we need to know should be available from the information we encoded in the SYN-ACK. A detailed description of the inner working of the syncookies mechanism is included in the comments in tcp_syncache.c. Reviewed by: silby (slightly earlier version) Sponsored by: TCP/IP Optimization Fundraise 2005
* Back when we had T/TCP support, we used to apply differentru2006-09-071-1/+1
| | | | | | | | | | | timeouts for TCP and T/TCP connections in the TIME_WAIT state, and we had two separate timed wait queues for them. Now that is has gone, the timeout is always 2*MSL again, and there is no reason to keep two queues (the first was unused anyway!). Also, reimplement the remaining queue using a TAILQ (it was technically impossible before, with two queues).
* First step of TSO (TCP segmentation offload) support in our network stack.andre2006-09-061-2/+3
| | | | | | | | | | | | o add IFCAP_TSO[46] for drivers to announce this capability for IPv4 and IPv6 o add CSUM_TSO flag to mbuf pkthdr csum_flags field o add tso_segsz field to mbuf pkthdr o enhance ip_output() packet length check to allow for large TSO packets o extend tcp_maxmtu[46]() with a flag pointer to pass interface capabilities o adjust all callers of tcp_maxmtu[46]() accordingly Discussed on: -current, -net Sponsored by: TCP/IP Optimization Fundraise 2005
* o Backout rev. 1.125 of in_pcb.c. It appeared to behave extremelyglebius2006-09-061-0/+2
| | | | | | | | | | | | | | | | | | | | bad under high load. For example with 40k sockets and 25k tcptw entries, connect() syscall can run for seconds. Debugging showed that it iterates the cycle millions times and purges thousands of tcptw entries at a time. Besides practical unusability this change is architecturally wrong. First, in_pcblookup_local() is used in connect() and bind() syscalls. No stale entries purging shouldn't be done here. Second, it is a layering violation. o Return back the tcptw purging cycle to tcp_timer_2msl_tw(), that was removed in rev. 1.78 by rwatson. The commit log of this revision tells nothing about the reason cycle was removed. Now we need this cycle, since major cleaner of stale tcptw structures is removed. o Disable probably necessary, but now unused tcp_twrecycleable() function. Reviewed by: ru
* Some cleanups and janitorial work to tcp_dooptions():andre2006-06-261-3/+8
| | | | | | | | | | | | | | | | o redefine the parameter 'is_syn' to 'flags', add TO_SYN flag and adjust its usage accordingly o update the comments to the tcp_dooptions() invocation in tcp_input():after_listen to reflect reality o move the logic checking the echoed timestamp out of tcp_dooptions() to the only place that uses it next to the invocation described in the previous item o adjust parsing of TCPOPT_SACK_PERMITTED to use the same style as the others o add comments in to struct tcpopt.to_flags #defines No functional changes. Sponsored by: TCP/IP Optimization Fundraise 2005
* Move all syncache related structures to tcp_syncache.c. They are only usedandre2006-06-181-39/+4
| | | | | | | | there. This unbreaks userland programs that include tcp_var.h. Discussed with: rwatson
* Rearrange fields in struct syncache and syncache_head to make them moreandre2006-06-171-5/+6
| | | | | | cache line friendly. Sponsored by: TCP/IP Optimization Fundraise 2005
* Add locking to TCP syncache and drop the global tcpinfo lock as earlyandre2006-06-171-6/+9
| | | | | | | | | | | | | | | | | | as possible for the syncache_add() case. The syncache timer no longer aquires the tcpinfo lock and timeout/retransmit runs can happen in parallel with bucket granularity. On a P4 the additional locks cause a slight degression of 0.7% in tcp connections per second. When IP and TCP input are deserialized and can run in parallel this little overhead can be neglected. The syncookie handling still leaves room for improvement and its random salts may be moved to the syncache bucket head structures to remove the second lock operation currently required for it. However this would be a more involved change from the way syncookies work at the moment. Reviewed by: rwatson Tested by: rwatson, ps (earlier version) Sponsored by: TCP/IP Optimization Fundraise 2005
* Update TCP for infrastructural changes to the socket/pcb refcount model,rwatson2006-04-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pru_abort(), pru_detach(), and in_pcbdetach(): - Universally support and enforce the invariant that so_pcb is never NULL, converting dozens of unnecessary NULL checks into assertions, and eliminating dozens of unnecessary error handling cases in protocol code. - In some cases, eliminate unnecessary pcbinfo locking, as it is no longer required to ensure so_pcb != NULL. For example, the receive code no longer requires the pcbinfo lock, and the send code only requires it if building a new connection on an otherwise unconnected socket triggered via sendto() with an address. This should significnatly reduce tcbinfo lock contention in the receive and send cases. - In order to support the invariant that so_pcb != NULL, it is now necessary for the TCP code to not discard the tcpcb any time a connection is dropped, but instead leave the tcpcb until the socket is shutdown. This case is handled by setting INP_DROPPED, to substitute for using a NULL so_pcb to indicate that the connection has been dropped. This requires the inpcb lock, but not the pcbinfo lock. - Unlike all other protocols in the tree, TCP may need to retain access to the socket after the file descriptor has been closed. Set SS_PROTOREF in tcp_detach() in order to prevent the socket from being freed, and add a flag, INP_SOCKREF, so that the TCP code knows whether or not it needs to free the socket when the connection finally does close. The typical case where this occurs is if close() is called on a TCP socket before all sent data in the send socket buffer has been transmitted or acknowledged. If INP_SOCKREF is found when the connection is dropped, we release the inpcb, tcpcb, and socket instead of flagging INP_DROPPED. - Abort and detach protocol switch methods no longer return failures, nor attempt to free sockets, as the socket layer does this. - Annotate the existence of a long-standing race in the TCP timer code, in which timers are stopped but not drained when the socket is freed, as waiting for drain may lead to deadlocks, or have to occur in a context where waiting is not permitted. This race has been handled by testing to see if the tcpcb pointer in the inpcb is NULL (and vice versa), which is not normally permitted, but may be true of a inpcb and tcpcb have been freed. Add a counter to test how often this race has actually occurred, and a large comment for each instance where we compare potentially freed memory with NULL. This will have to be fixed in the near future, but requires is to further address how to handle the timer shutdown shutdown issue. - Several TCP calls no longer potentially free the passed inpcb/tcpcb, so no longer need to return a pointer to indicate whether the argument passed in is still valid. - Un-macroize debugging and locking setup for various protocol switch methods for TCP, as it lead to more obscurity, and as locking becomes more customized to the methods, offers less benefit. - Assert copyright on tcp_usrreq.c due to significant modifications that have been made as part of this work. These changes significantly modify the memory management and connection logic of our TCP implementation, and are (as such) High Risk Changes, and likely to contain serious bugs. Please report problems to the current@ mailing list ASAP, ideally with simple test cases, and optionally, packet traces. MFC after: 3 months
* Rework TCP window scaling (RFC1323) to properly scale the send windowandre2006-02-281-1/+1
| | | | | | | | | | | | | right from the beginning and partly clean up the differences in handling between SYN_SENT and SYN_RCVD (syncache). Further changes to this code to come. This is a first incremental step to a general overhaul and streamlining of the TCP code. PR: kern/15095 PR: kern/92690 (partly) Reviewed by: qingli (and tested with ANVL) Sponsored by: TCP/IP Optimization Fundraise 2005
* Have TCP Inflight disable itself if the RTT is below a certainandre2006-02-161-0/+1
| | | | | | | | | | | | | | threshold. Inflight doesn't make sense on a LAN as it has trouble figuring out the maximal bandwidth because of the coarse tick granularity. The sysctl net.inet.tcp.inflight.rttthresh specifies the threshold in milliseconds below which inflight will disengage. It defaults to 10ms. Tested by: Joao Barros <joao.barros-at-gmail.com>, Rich Murphey <rich-at-whiteoaklabs.com> Sponsored by: TCP/IP Optimization Fundraise 2005
* - Postpone SACK option processing until after PAWS checks. SACK optionps2005-06-271-3/+3
| | | | | | | | | | | processing is now done in the ACK processing case. - Merge tcp_sack_option() and tcp_del_sackholes() into a new function called tcp_sack_doack(). - Test (SEG.ACK < SND.MAX) before processing the ACK. Submitted by: Noritoshi Demizu Reveiewed by: Mohan Srinivasan, Raja Mukerji Approved by: re
* Changes to tcp_sack_option() thatps2005-06-041-1/+2
| | | | | | | | | | - Walks the scoreboard backwards from the tail to reduce the number of comparisons for each sack option received. - Introduce functions to add/remove sack scoreboard elements, making the code more readable. Submitted by: Noritoshi Demizu Reviewed by: Raja Mukerji, Mohan Srinivasan
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