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* tcp: fix ssthresh and undo for consecutive short FRTO episodesNeal Cardwell2014-08-141-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix TCP FRTO logic so that it always notices when snd_una advances, indicating that any RTO after that point will be a new and distinct loss episode. Previously there was a very specific sequence that could cause FRTO to fail to notice a new loss episode had started: (1) RTO timer fires, enter FRTO and retransmit packet 1 in write queue (2) receiver ACKs packet 1 (3) FRTO sends 2 more packets (4) RTO timer fires again (should start a new loss episode) The problem was in step (3) above, where tcp_process_loss() returned early (in the spot marked "Step 2.b"), so that it never got to the logic to clear icsk_retransmits. Thus icsk_retransmits stayed non-zero. Thus in step (4) tcp_enter_loss() would see the non-zero icsk_retransmits, decide that this RTO is not a new episode, and decide not to cut ssthresh and remember the current cwnd and ssthresh for undo. There were two main consequences to the bug that we have observed. First, ssthresh was not decreased in step (4). Second, when there was a series of such FRTO (1-4) sequences that happened to be followed by an FRTO undo, we would restore the cwnd and ssthresh from before the entire series started (instead of the cwnd and ssthresh from before the most recent RTO). This could result in cwnd and ssthresh being restored to values much bigger than the proper values. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Fixes: e33099f96d99c ("tcp: implement RFC5682 F-RTO") Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: don't allow syn packets without timestamps to pass tcp_tw_recycle logicHannes Frederic Sowa2014-08-142-5/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tcp_tw_recycle heavily relies on tcp timestamps to build a per-host ordering of incoming connections and teardowns without the need to hold state on a specific quadruple for TCP_TIMEWAIT_LEN, but only for the last measured RTO. To do so, we keep the last seen timestamp in a per-host indexed data structure and verify if the incoming timestamp in a connection request is strictly greater than the saved one during last connection teardown. Thus we can verify later on that no old data packets will be accepted by the new connection. During moving a socket to time-wait state we already verify if timestamps where seen on a connection. Only if that was the case we let the time-wait socket expire after the RTO, otherwise normal TCP_TIMEWAIT_LEN will be used. But we don't verify this on incoming SYN packets. If a connection teardown was less than TCP_PAWS_MSL seconds in the past we cannot guarantee to not accept data packets from an old connection if no timestamps are present. We should drop this SYN packet. This patch closes this loophole. Please note, this patch does not make tcp_tw_recycle in any way more usable but only adds another safety check: Sporadic drops of SYN packets because of reordering in the network or in the socket backlog queues can happen. Users behing NAT trying to connect to a tcp_tw_recycle enabled server can get caught in blackholes and their connection requests may regullary get dropped because hosts behind an address translator don't have synchronized tcp timestamp clocks. tcp_tw_recycle cannot work if peers don't have tcp timestamps enabled. In general, use of tcp_tw_recycle is disadvised. Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()Neal Cardwell2014-08-142-3/+4
| | | | | | | | | | | | | | | | Make sure we use the correct address-family-specific function for handling MTU reductions from within tcp_release_cb(). Previously AF_INET6 sockets were incorrectly always using the IPv6 code path when sometimes they were handling IPv4 traffic and thus had an IPv4 dst. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Diagnosed-by: Willem de Bruijn <willemb@google.com> Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications") Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: don't use timestamp from repaired skb-s to calculate RTT (v2)Andrey Vagin2014-08-142-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We don't know right timestamp for repaired skb-s. Wrong RTT estimations isn't good, because some congestion modules heavily depends on it. This patch adds the TCPCB_REPAIRED flag, which is included in TCPCB_RETRANS. Thanks to Eric for the advice how to fix this issue. This patch fixes the warning: [ 879.562947] WARNING: CPU: 0 PID: 2825 at net/ipv4/tcp_input.c:3078 tcp_ack+0x11f5/0x1380() [ 879.567253] CPU: 0 PID: 2825 Comm: socket-tcpbuf-l Not tainted 3.16.0-next-20140811 #1 [ 879.567829] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 879.568177] 0000000000000000 00000000c532680c ffff880039643d00 ffffffff817aa2d2 [ 879.568776] 0000000000000000 ffff880039643d38 ffffffff8109afbd ffff880039d6ba80 [ 879.569386] ffff88003a449800 000000002983d6bd 0000000000000000 000000002983d6bc [ 879.569982] Call Trace: [ 879.570264] [<ffffffff817aa2d2>] dump_stack+0x4d/0x66 [ 879.570599] [<ffffffff8109afbd>] warn_slowpath_common+0x7d/0xa0 [ 879.570935] [<ffffffff8109b0ea>] warn_slowpath_null+0x1a/0x20 [ 879.571292] [<ffffffff816d0a05>] tcp_ack+0x11f5/0x1380 [ 879.571614] [<ffffffff816d10bd>] tcp_rcv_established+0x1ed/0x710 [ 879.571958] [<ffffffff816dc9da>] tcp_v4_do_rcv+0x10a/0x370 [ 879.572315] [<ffffffff81657459>] release_sock+0x89/0x1d0 [ 879.572642] [<ffffffff816c81a0>] do_tcp_setsockopt.isra.36+0x120/0x860 [ 879.573000] [<ffffffff8110a52e>] ? rcu_read_lock_held+0x6e/0x80 [ 879.573352] [<ffffffff816c8912>] tcp_setsockopt+0x32/0x40 [ 879.573678] [<ffffffff81654ac4>] sock_common_setsockopt+0x14/0x20 [ 879.574031] [<ffffffff816537b0>] SyS_setsockopt+0x80/0xf0 [ 879.574393] [<ffffffff817b40a9>] system_call_fastpath+0x16/0x1b [ 879.574730] ---[ end trace a17cbc38eb8c5c00 ]--- v2: moving setting of skb->when for repaired skb-s in tcp_write_xmit, where it's set for other skb-s. Fixes: 431a91242d8d ("tcp: timestamp SYN+DATA messages") Fixes: 740b0f1841f6 ("tcp: switch rtt estimations to usec resolution") Cc: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net-timestamp: fix missing tcp fragmentation casesWillem de Bruijn2014-08-131-0/+17
| | | | | | | | | | | | | | | Bytestream timestamps are correlated with a single byte in the skbuff, recorded in skb_shinfo(skb)->tskey. When fragmenting skbuffs, ensure that the tskey is set for the fragment in which the tskey falls (seqno <= tskey < end_seqno). The original implementation did not address fragmentation in tcp_fragment or tso_fragment. Add code to inspect the sequence numbers and move both tskey and the relevant tx_flags if necessary. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net-timestamp: fix missing ACK timestampWillem de Bruijn2014-08-131-5/+5
| | | | | | | | | | | | | | | ACK timestamps are generated in tcp_clean_rtx_queue. The TSO datapath can break out early, causing the timestamp code to be skipped. Move the code up before the break. Reported-by: David S. Miller <davem@davemloft.net> Also fix a boundary condition: tp->snd_una is the next unacknowledged byte and between tests inclusive (a <= b <= c), so generate a an ACK timestamp if (prior_snd_una <= tskey <= tp->snd_una - 1). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: removed redundant conditionalNiv Yehezkel2014-08-081-2/+0
| | | | | | | | Since fib_lookup cannot return ESRCH no longer, checking for this error code is no longer neccesary. Signed-off-by: Niv Yehezkel <executerx@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'akpm' (patchbomb from Andrew Morton)Linus Torvalds2014-08-061-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge incoming from Andrew Morton: - Various misc things. - arch/sh updates. - Part of ocfs2. Review is slow. - Slab updates. - Most of -mm. - printk updates. - lib/ updates. - checkpatch updates. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (226 commits) checkpatch: update $declaration_macros, add uninitialized_var checkpatch: warn on missing spaces in broken up quoted checkpatch: fix false positives for --strict "space after cast" test checkpatch: fix false positive MISSING_BREAK warnings with --file checkpatch: add test for native c90 types in unusual order checkpatch: add signed generic types checkpatch: add short int to c variable types checkpatch: add for_each tests to indentation and brace tests checkpatch: fix brace style misuses of else and while checkpatch: add --fix option for a couple OPEN_BRACE misuses checkpatch: use the correct indentation for which() checkpatch: add fix_insert_line and fix_delete_line helpers checkpatch: add ability to insert and delete lines to patch/file checkpatch: add an index variable for fixed lines checkpatch: warn on break after goto or return with same tab indentation checkpatch: emit a warning on file add/move/delete checkpatch: add test for commit id formatting style in commit log checkpatch: emit fewer kmalloc_array/kcalloc conversion warnings checkpatch: improve "no space after cast" test checkpatch: allow multiple const * types ...
| * list: fix order of arguments for hlist_add_after(_rcu)Ken Helias2014-08-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All other add functions for lists have the new item as first argument and the position where it is added as second argument. This was changed for no good reason in this function and makes using it unnecessary confusing. The name was changed to hlist_add_behind() to cause unconverted code to generate a compile error instead of using the wrong parameter order. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Ken Helias <kenhelias@firemail.de> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> [intel driver bits] Cc: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | tcp: md5: check md5 signature without socket lockDmitry Popov2014-08-061-11/+25
| | | | | | | | | | | | | | | | | | | | | | Since a8afca032 (tcp: md5: protects md5sig_info with RCU) tcp_md5_do_lookup doesn't require socket lock, rcu_read_lock is enough. Therefore socket lock is no longer required for tcp_v{4,6}_inbound_md5_hash too, so we can move these calls (wrapped with rcu_read_{,un}lock) before bh_lock_sock: from tcp_v{4,6}_do_rcv to tcp_v{4,6}_rcv. Signed-off-by: Dmitry Popov <ixaphire@qrator.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net-timestamp: cumulative tcp timestamping fixesWillem de Bruijn2014-08-062-9/+11
|/ | | | | | | | | | | | | | | A set of small fixes pointed out just after the merge: - make tcp_tx_timestamp static - make tcp_gso_tstamp static - use before() to compare TCP seqno, instead of cast to u64 - add tstamp to tx_flags in GSO, instead of overwrite tx_flags - record skb_shinfo(skb)->tskey for all timestamps, also HW. - optimization in tcp_tx_timestamp: call sock_tx_timestamp only if a tstamp option is set. Signed-off-by: Willem de Bruijn <willemb@google.com> Fixes: 4ed2d765dfac ("net-timestamp: TCP timestamping") Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2014-08-0644-1064/+1416
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Highlights: 1) Steady transitioning of the BPF instructure to a generic spot so all kernel subsystems can make use of it, from Alexei Starovoitov. 2) SFC driver supports busy polling, from Alexandre Rames. 3) Take advantage of hash table in UDP multicast delivery, from David Held. 4) Lighten locking, in particular by getting rid of the LRU lists, in inet frag handling. From Florian Westphal. 5) Add support for various RFC6458 control messages in SCTP, from Geir Ola Vaagland. 6) Allow to filter bridge forwarding database dumps by device, from Jamal Hadi Salim. 7) virtio-net also now supports busy polling, from Jason Wang. 8) Some low level optimization tweaks in pktgen from Jesper Dangaard Brouer. 9) Add support for ipv6 address generation modes, so that userland can have some input into the process. From Jiri Pirko. 10) Consolidate common TCP connection request code in ipv4 and ipv6, from Octavian Purdila. 11) New ARP packet logger in netfilter, from Pablo Neira Ayuso. 12) Generic resizable RCU hash table, with intial users in netlink and nftables. From Thomas Graf. 13) Maintain a name assignment type so that userspace can see where a network device name came from (enumerated by kernel, assigned explicitly by userspace, etc.) From Tom Gundersen. 14) Automatic flow label generation on transmit in ipv6, from Tom Herbert. 15) New packet timestamping facilities from Willem de Bruijn, meant to assist in measuring latencies going into/out-of the packet scheduler, latency from TCP data transmission to ACK, etc" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1536 commits) cxgb4 : Disable recursive mailbox commands when enabling vi net: reduce USB network driver config options. tg3: Modify tg3_tso_bug() to handle multiple TX rings amd-xgbe: Perform phy connect/disconnect at dev open/stop amd-xgbe: Use dma_set_mask_and_coherent to set DMA mask net: sun4i-emac: fix memory leak on bad packet sctp: fix possible seqlock seadlock in sctp_packet_transmit() Revert "net: phy: Set the driver when registering an MDIO bus device" cxgb4vf: Turn off SGE RX/TX Callback Timers and interrupts in PCI shutdown routine team: Simplify return path of team_newlink bridge: Update outdated comment on promiscuous mode net-timestamp: ACK timestamp for bytestreams net-timestamp: TCP timestamping net-timestamp: SCHED timestamp on entering packet scheduler net-timestamp: add key to disambiguate concurrent datagrams net-timestamp: move timestamp flags out of sk_flags net-timestamp: extend SCM_TIMESTAMPING ancillary data struct cxgb4i : Move stray CPL definitions to cxgb4 driver tcp: reduce spurious retransmits due to transient SACK reneging qlcnic: Initialize dcbnl_ops before register_netdev ...
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-08-053-13/+21
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/Makefile net/ipv6/sysctl_net_ipv6.c Two ipv6_table_template[] additions overlap, so the index of the ipv6_table[x] assignments needed to be adjusted. In the drivers/net/Makefile case, we've gotten rid of the garbage whereby we had to list every single USB networking driver in the top-level Makefile, there is just one "USB_NETWORKING" that guards everything. Signed-off-by: David S. Miller <davem@davemloft.net>
| | * tcp: Fix integer-overflow in TCP vegasChristoph Paasch2014-07-301-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In vegas we do a multiplication of the cwnd and the rtt. This may overflow and thus their result is stored in a u64. However, we first need to cast the cwnd so that actually 64-bit arithmetic is done. Then, we need to do do_div to allow this to be used on 32-bit arches. Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Doug Leith <doug.leith@nuim.ie> Fixes: 8d3a564da34e (tcp: tcp_vegas cong avoid fix) Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
| | * tcp: Fix integer-overflows in TCP venoChristoph Paasch2014-07-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In veno we do a multiplication of the cwnd and the rtt. This may overflow and thus their result is stored in a u64. However, we first need to cast the cwnd so that actually 64-bit arithmetic is done. A first attempt at fixing 76f1017757aa0 ([TCP]: TCP Veno congestion control) was made by 159131149c2 (tcp: Overflow bug in Vegas), but it failed to add the required cast in tcp_veno_cong_avoid(). Fixes: 76f1017757aa0 ([TCP]: TCP Veno congestion control) Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: David S. Miller <davem@davemloft.net>
| | * ip_tunnel(ipv4): fix tunnels with "local any remote $remote_ip"Dmitry Popov2014-07-301-11/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ipv4 tunnels created with "local any remote $ip" didn't work properly since 7d442fab0 (ipv4: Cache dst in tunnels). 99% of packets sent via those tunnels had src addr = 0.0.0.0. That was because only dst_entry was cached, although fl4.saddr has to be cached too. Every time ip_tunnel_xmit used cached dst_entry (tunnel_rtable_get returned non-NULL), fl4.saddr was initialized with tnl_params->saddr (= 0 in our case), and wasn't changed until iptunnel_xmit(). This patch adds saddr to ip_tunnel->dst_cache, fixing this issue. Reported-by: Sergey Popov <pinkbyte@gentoo.org> Signed-off-by: Dmitry Popov <ixaphire@qrator.net> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net-timestamp: ACK timestamp for bytestreamsWillem de Bruijn2014-08-051-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add SOF_TIMESTAMPING_TX_ACK, a request for a tstamp when the last byte in the send() call is acknowledged. It implements the feature for TCP. The timestamp is generated when the TCP socket cumulative ACK is moved beyond the tracked seqno for the first time. The feature ignores SACK and FACK, because those acknowledge the specific byte, but not necessarily the entire contents of the buffer up to that byte. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net-timestamp: TCP timestampingWillem de Bruijn2014-08-052-3/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TCP timestamping extends SO_TIMESTAMPING to bytestreams. Bytestreams do not have a 1:1 relationship between send() buffers and network packets. The feature interprets a send call on a bytestream as a request for a timestamp for the last byte in that send() buffer. The choice corresponds to a request for a timestamp when all bytes in the buffer have been sent. That assumption depends on in-order kernel transmission. This is the common case. That said, it is possible to construct a traffic shaping tree that would result in reordering. The guarantee is strong, then, but not ironclad. This implementation supports send and sendpages (splice). GSO replaces one large packet with multiple smaller packets. This patch also copies the option into the correct smaller packet. This patch does not yet support timestamping on data in an initial TCP Fast Open SYN, because that takes a very different data path. If ID generation in ee_data is enabled, bytestream timestamps return a byte offset, instead of the packet counter for datagrams. The implementation supports a single timestamp per packet. It silenty replaces requests for previous timestamps. To avoid missing tstamps, flush the tcp queue by disabling Nagle, cork and autocork. Missing tstamps can be detected by offset when the ee_data ID is enabled. Implementation details: - On GSO, the timestamping code can be included in the main loop. I moved it into its own loop to reduce the impact on the common case to a single branch. - To avoid leaking the absolute seqno to userspace, the offset returned in ee_data must always be relative. It is an offset between an skb and sk field. The first is always set (also for GSO & ACK). The second must also never be uninitialized. Only allow the ID option on sockets in the ESTABLISHED state, for which the seqno is available. Never reset it to zero (instead, move it to the current seqno when reenabling the option). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net-timestamp: add key to disambiguate concurrent datagramsWillem de Bruijn2014-08-051-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Datagrams timestamped on transmission can coexist in the kernel stack and be reordered in packet scheduling. When reading looped datagrams from the socket error queue it is not always possible to unique correlate looped data with original send() call (for application level retransmits). Even if possible, it may be expensive and complex, requiring packet inspection. Introduce a data-independent ID mechanism to associate timestamps with send calls. Pass an ID alongside the timestamp in field ee_data of sock_extended_err. The ID is a simple 32 bit unsigned int that is associated with the socket and incremented on each send() call for which software tx timestamp generation is enabled. The feature is enabled only if SOF_TIMESTAMPING_OPT_ID is set, to avoid changing ee_data for existing applications that expect it 0. The counter is reset each time the flag is reenabled. Reenabling does not change the ID of already submitted data. It is possible to receive out of order IDs if the timestamp stream is not quiesced first. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | tcp: reduce spurious retransmits due to transient SACK renegingNeal Cardwell2014-08-052-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit reduces spurious retransmits due to apparent SACK reneging by only reacting to SACK reneging that persists for a short delay. When a sequence space hole at snd_una is filled, some TCP receivers send a series of ACKs as they apparently scan their out-of-order queue and cumulatively ACK all the packets that have now been consecutiveyly received. This is essentially misbehavior B in "Misbehaviors in TCP SACK generation" ACM SIGCOMM Computer Communication Review, April 2011, so we suspect that this is from several common OSes (Windows 2000, Windows Server 2003, Windows XP). However, this issue has also been seen in other cases, e.g. the netdev thread "TCP being hoodwinked into spurious retransmissions by lack of timestamps?" from March 2014, where the receiver was thought to be a BSD box. Since snd_una would temporarily be adjacent to a previously SACKed range in these scenarios, this receiver behavior triggered the Linux SACK reneging code path in the sender. This led the sender to clear the SACK scoreboard, enter CA_Loss, and spuriously retransmit (potentially) every packet from the entire write queue at line rate just a few milliseconds before the ACK for each packet arrives at the sender. To avoid such situations, now when a sender sees apparent reneging it does not yet retransmit, but rather adjusts the RTO timer to give the receiver a little time (max(RTT/2, 10ms)) to send us some more ACKs that will restore sanity to the SACK scoreboard. If the reneging persists until this RTO then, as before, we clear the SACK scoreboard and enter CA_Loss. A 10ms delay tolerates a receiver sending such a stream of ACKs at 56Kbit/sec. And to allow for receivers with slower or more congested paths, we wait for at least RTT/2. We validated the resulting max(RTT/2, 10ms) delay formula with a mix of North American and South American Google web server traffic, and found that for ACKs displaying transient reneging: (1) 90% of inter-ACK delays were less than 10ms (2) 99% of inter-ACK delays were less than RTT/2 In tests on Google web servers this commit reduced reneging events by 75%-90% (as measured by the TcpExtTCPSACKReneging counter), without any measurable impact on latency for user HTTP and SPDY requests. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | tcp: md5: remove unneeded check in tcp_v4_parse_md5_keysDmitry Popov2014-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | tcpm_key is an array inside struct tcp_md5sig, there is no need to check it against NULL. Signed-off-by: Dmitry Popov <ixaphire@qrator.net> Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | inet: frags: use kmem_cache for inet_frag_queueNikolay Aleksandrov2014-08-022-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use kmem_cache to allocate/free inet_frag_queue objects since they're all the same size per inet_frags user and are alloced/freed in high volumes thus making it a perfect case for kmem_cache. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | inet: frags: use INET_FRAG_EVICTED to prevent icmp messagesNikolay Aleksandrov2014-08-022-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have INET_FRAG_EVICTED we might as well use it to stop sending icmp messages in the "frag_expire" functions instead of stripping INET_FRAG_FIRST_IN from their flags when evicting. Also fix the comment style in ip6_expire_frag_queue(). Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | inet: frags: fix function declaration alignments in inet_fragmentNikolay Aleksandrov2014-08-021-5/+9
| | | | | | | | | | | | | | | | | | | | | Fix a couple of functions' declaration alignments. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | inet: frags: rename last_in to flagsNikolay Aleksandrov2014-08-022-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | The last_in field has been used to store various flags different from first/last frag in so give it a more descriptive name: flags. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | ipv4: remove nested rcu_read_lock/unlockDuan Jiong2014-08-021-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ip_local_deliver_finish() already have a rcu_read_lock/unlock, so the rcu_read_lock/unlock is unnecessary. See the stack below: ip_local_deliver_finish | | ->icmp_rcv | | ->icmp_socket_deliver Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net: use inet6_iif instead of IP6CB()->iifDuan Jiong2014-07-311-1/+1
| | | | | | | | | | | | | | | Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net: fix the counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORSDuan Jiong2014-07-312-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When dealing with ICMPv[46] Error Message, function icmp_socket_deliver() and icmpv6_notify() do some valid checks on packet's length, but then some protocols check packet's length redaudantly. So remove those duplicated statements, and increase counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS in function icmp_socket_deliver() and icmpv6_notify() respectively. In addition, add missed counter in udp6/udplite6 when socket is NULL. Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller2014-07-312-2/+1
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains netfilter updates for net-next, they are: 1) Add the reject expression for the nf_tables bridge family, this allows us to send explicit reject (TCP RST / ICMP dest unrech) to the packets matching a rule. 2) Simplify and consolidate the nf_tables set dumping logic. This uses netlink control->data to filter out depending on the request. 3) Perform garbage collection in xt_hashlimit using a workqueue instead of a timer, which is problematic when many entries are in place in the tables, from Eric Dumazet. 4) Remove leftover code from the removed ulog target support, from Paul Bolle. 5) Dump unmodified flags in the netfilter packet accounting when resetting counters, so userspace knows that a counter was in overquota situation, from Alexey Perevalov. 6) Fix wrong usage of the bitwise functions in nfnetlink_acct, also from Alexey. 7) Fix a crash when adding new set element with an empty NFTA_SET_ELEM_LIST attribute. This patchset also includes a couple of cleanups for xt_LED from Duan Jiong and for nf_conntrack_ipv4 (using coccinelle) from Himangi Saraogi. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | netfilter: kill remnants of ulog targetsPaul Bolle2014-07-251-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ulog targets were recently killed. A few references to the Kconfig macros CONFIG_IP_NF_TARGET_ULOG and CONFIG_BRIDGE_EBT_ULOG were left untouched. Kill these too. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| | * | netfilter: nf_conntrack: remove exceptional & on function nameHimangi Saraogi2014-07-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this file, function names are otherwise used as pointers without &. A simplified version of the Coccinelle semantic patch that makes this change is as follows: // <smpl> @r@ identifier f; @@ f(...) { ... } @@ identifier r.f; @@ - &f + f // </smpl> Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| * | | tcp: don't require root to read tcp_metricsBanerjee, Debabrata2014-07-311-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d23ff7016 (tcp: add generic netlink support for tcp_metrics) introduced netlink support for the new tcp_metrics, however it restricted getting of tcp_metrics to root user only. This is a change from how these values could have been fetched when in the old route cache. Unless there's a legitimate reason to restrict the reading of these values it would be better if normal users could fetch them. Cc: Julian Anastasov <ja@ssi.bg> Cc: linux-kernel@vger.kernel.org Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | Merge branch 'master' of ↵David S. Miller2014-07-302-34/+22
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2014-07-30 This is the last pull request for ipsec-next before I'll be off for two weeks starting on friday. David, can you please take urgent ipsec patches directly into net/net-next during this time? 1) Error handling simplifications for vti and vti6. From Mathias Krause. 2) Remove a duplicate semicolon after a return statement. From Christoph Paasch. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * | | xfrm4: Remove duplicate semicolonChristoph Paasch2014-06-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 3328715e6c1fc (xfrm4: Add IPsec protocol multiplexer) adds a duplicate semicolon after the return-statement. Although it has no negative impact, the second semicolon should be removed. Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Christoph Paasch <christoph.paasch@uclouvain.be> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
| | * | | vti: Simplify error handling in module init and exitMathias Krause2014-06-261-33/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The error handling in the module init and exit functions can be shortened to safe us some code. 1/ Remove the code duplications in the init function, jump straight to the existing cleanup code by adding some labels. Also give the error message some more value by telling the reason why loading the module has failed. Furthermore fix the "IPSec" typo -- it should be "IPsec" instead. 2/ Remove the error handling in the exit function as the only legitimate reason xfrm4_protocol_deregister() might fail is inet_del_protocol() returning -1. That, in turn, means some other protocol handler had been registered for this very protocol in the meantime. But that essentially means we haven't been handling that protocol any more, anyway. What it definitely means not is that we "can't deregister tunnel". Therefore just get rid of that bogus warning. It's plain wrong. Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
| * | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-07-301-3/+29
| |\ \ \ \ | | | |_|/ | | |/| | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | ipv4: clean up cast warning in do_ip_getsockoptKaroly Kemeny2014-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sparse warns because of implicit pointer cast. v2: subject line correction, space between "void" and "*" Signed-off-by: Karoly Kemeny <karoly.kemeny@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | net/udp_offload: Use IS_ERR_OR_NULLHimangi Saraogi2014-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces the use of the macro IS_ERR_OR_NULL in place of tests for NULL and IS_ERR. The following Coccinelle semantic patch was used for making the change: @@ expression e; @@ - e == NULL || IS_ERR(e) + IS_ERR_OR_NULL(e) || ... Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | net/ipv4: Use IS_ERR_OR_NULLHimangi Saraogi2014-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces the use of the macro IS_ERR_OR_NULL in place of tests for NULL and IS_ERR. The following Coccinelle semantic patch was used for making the change: @@ expression e; @@ - e == NULL || IS_ERR(e) + IS_ERR_OR_NULL(e) || ... Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | ipv4: fail early when creating netdev named all or defaultWANG Cong2014-07-291-9/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We create a proc dir for each network device, this will cause conflicts when the devices have name "all" or "default". Rather than emitting an ugly kernel warning, we could just fail earlier by checking the device name. Reported-by: Stephane Chazelas <stephane.chazelas@gmail.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: set limits and make init_net's high_thresh limit globalNikolay Aleksandrov2014-07-271-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes init_net's high_thresh limit to be the maximum for all namespaces, thus introducing a global memory limit threshold equal to the sum of the individual high_thresh limits which are capped. It also introduces some sane minimums for low_thresh as it shouldn't be able to drop below 0 (or > high_thresh in the unsigned case), and overall low_thresh should not ever be above high_thresh, so we make the following relations for a namespace: init_net: high_thresh - max(not capped), min(init_net low_thresh) low_thresh - max(init_net high_thresh), min (0) all other namespaces: high_thresh = max(init_net high_thresh), min(namespace's low_thresh) low_thresh = max(namespace's high_thresh), min(0) The major issue with having low_thresh > high_thresh is that we'll schedule eviction but never evict anything and thus rely only on the timers. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: use seqlock for hash rebuildFlorian Westphal2014-07-272-34/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rehash is rare operation, don't force readers to take the read-side rwlock. Instead, we only have to detect the (rare) case where the secret was altered while we are trying to insert a new inetfrag queue into the table. If it was changed, drop the bucket lock and recompute the hash to get the 'new' chain bucket that we have to insert into. Joint work with Nikolay Aleksandrov. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: remove periodic secret rebuild timerFlorian Westphal2014-07-272-16/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | merge functionality into the eviction workqueue. Instead of rebuilding every n seconds, take advantage of the upper hash chain length limit. If we hit it, mark table for rebuild and schedule workqueue. To prevent frequent rebuilds when we're completely overloaded, don't rebuild more than once every 5 seconds. ipfrag_secret_interval sysctl is now obsolete and has been marked as deprecated, it still can be changed so scripts won't be broken but it won't have any effect. A comment is left above each unused secret_timer variable to avoid confusion. Joint work with Nikolay Aleksandrov. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: remove lru listFlorian Westphal2014-07-272-11/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | no longer used. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: don't account number of fragment queuesFlorian Westphal2014-07-273-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'nqueues' counter is protected by the lru list lock, once thats removed this needs to be converted to atomic counter. Given this isn't used for anything except for reporting it to userspace via /proc, just remove it. We still report the memory currently used by fragment reassembly queues. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: move eviction of queues to work queueFlorian Westphal2014-07-272-44/+101
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the high_thresh limit is reached we try to toss the 'oldest' incomplete fragment queues until memory limits are below the low_thresh value. This happens in softirq/packet processing context. This has two drawbacks: 1) processors might evict a queue that was about to be completed by another cpu, because they will compete wrt. resource usage and resource reclaim. 2) LRU list maintenance is expensive. But when constantly overloaded, even the 'least recently used' element is recent, so removing 'lru' queue first is not 'fairer' than removing any other fragment queue. This moves eviction out of the fast path: When the low threshold is reached, a work queue is scheduled which then iterates over the table and removes the queues that exceed the memory limits of the namespace. It sets a new flag called INET_FRAG_EVICTED on the evicted queues so the proper counters will get incremented when the queue is forcefully expired. When the high threshold is reached, no more fragment queues are created until we're below the limit again. The LRU list is now unused and will be removed in a followup patch. Joint work with Nikolay Aleksandrov. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: move evictor calls into frag_find functionFlorian Westphal2014-07-272-22/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | First step to move eviction handling into a work queue. We lose two spots that accounted evicted fragments in MIB counters. Accounting will be restored since the upcoming work-queue evictor invokes the frag queue timer callbacks instead. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: remove hash size assumptions from callersFlorian Westphal2014-07-272-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hide actual hash size from individual users: The _find function will now fold the given hash value into the required range. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | inet: frag: constify match, hashfn and constructor argumentsFlorian Westphal2014-07-271-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | igmp: remove exceptional & on function nameHimangi Saraogi2014-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this file, function names are otherwise used as pointers without &. A simplified version of the Coccinelle semantic patch that makes this change is as follows: // <smpl> @r@ identifier f; @@ f(...) { ... } @@ identifier r.f; @@ - &f + f // </smpl> Signed-off-by: Himangi Saraogi <himangi774@gmail.com> Acked-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
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