summaryrefslogtreecommitdiff
path: root/net/ipv4/tcp_input.c
AgeCommit message (Collapse)AuthorFilesLines
2014-07-28tcp: fix false undo corner casesYuchung Cheng1-4/+4
[ Upstream commit 6e08d5e3c8236e7484229e46fdf92006e1dd4c49 ] The undo code assumes that, upon entering loss recovery, TCP 1) always retransmit something 2) the retransmission never fails locally (e.g., qdisc drop) so undo_marker is set in tcp_enter_recovery() and undo_retrans is incremented only when tcp_retransmit_skb() is successful. When the assumption is broken because TCP's cwnd is too small to retransmit or the retransmit fails locally. The next (DUP)ACK would incorrectly revert the cwnd and the congestion state in tcp_try_undo_dsack() or tcp_may_undo(). Subsequent (DUP)ACKs may enter the recovery state. The sender repeatedly enter and (incorrectly) exit recovery states if the retransmits continue to fail locally while receiving (DUP)ACKs. The fix is to initialize undo_retrans to -1 and start counting on the first retransmission. Always increment undo_retrans even if the retransmissions fail locally because they couldn't cause DSACKs to undo the cwnd reduction. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-28tcp: fix tcp_match_skb_to_sack() for unaligned SACK at end of an skbNeal Cardwell1-1/+1
[ Upstream commit 2cd0d743b05e87445c54ca124a9916f22f16742e ] If there is an MSS change (or misbehaving receiver) that causes a SACK to arrive that covers the end of an skb but is less than one MSS, then tcp_match_skb_to_sack() was rounding up pkt_len to the full length of the skb ("Round if necessary..."), then chopping all bytes off the skb and creating a zero-byte skb in the write queue. This was visible now because the recently simplified TLP logic in bef1909ee3ed1c ("tcp: fixing TLP's FIN recovery") could find that 0-byte skb at the end of the write queue, and now that we do not check that skb's length we could send it as a TLP probe. Consider the following example scenario: mss: 1000 skb: seq: 0 end_seq: 4000 len: 4000 SACK: start_seq: 3999 end_seq: 4000 The tcp_match_skb_to_sack() code will compute: in_sack = false pkt_len = start_seq - TCP_SKB_CB(skb)->seq = 3999 - 0 = 3999 new_len = (pkt_len / mss) * mss = (3999/1000)*1000 = 3000 new_len += mss = 4000 Previously we would find the new_len > skb->len check failing, so we would fall through and set pkt_len = new_len = 4000 and chop off pkt_len of 4000 from the 4000-byte skb, leaving a 0-byte segment afterward in the write queue. With this new commit, we notice that the new new_len >= skb->len check succeeds, so that we return without trying to fragment. Fixes: adb92db857ee ("tcp: Make SACK code to split only at mss boundaries") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Ilpo Jarvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04tcp: do not forget FIN in tcp_shifted_skb()Eric Dumazet1-1/+4
[ Upstream commit 5e8a402f831dbe7ee831340a91439e46f0d38acd ] Yuchung found following problem : There are bugs in the SACK processing code, merging part in tcp_shift_skb_data(), that incorrectly resets or ignores the sacked skbs FIN flag. When a receiver first SACK the FIN sequence, and later throw away ofo queue (e.g., sack-reneging), the sender will stop retransmitting the FIN flag, and hangs forever. Following packetdrill test can be used to reproduce the bug. $ cat sack-merge-bug.pkt `sysctl -q net.ipv4.tcp_fack=0` // Establish a connection and send 10 MSS. 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +.000 bind(3, ..., ...) = 0 +.000 listen(3, 1) = 0 +.050 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> +.000 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 6> +.001 < . 1:1(0) ack 1 win 1024 +.000 accept(3, ..., ...) = 4 +.100 write(4, ..., 12000) = 12000 +.000 shutdown(4, SHUT_WR) = 0 +.000 > . 1:10001(10000) ack 1 +.050 < . 1:1(0) ack 2001 win 257 +.000 > FP. 10001:12001(2000) ack 1 +.050 < . 1:1(0) ack 2001 win 257 <sack 10001:11001,nop,nop> +.050 < . 1:1(0) ack 2001 win 257 <sack 10001:12002,nop,nop> // SACK reneg +.050 < . 1:1(0) ack 12001 win 257 +0 %{ print "unacked: ",tcpi_unacked }% +5 %{ print "" }% First, a typo inverted left/right of one OR operation, then code forgot to advance end_seq if the merged skb carried FIN. Bug was added in 2.6.29 by commit 832d11c5cd076ab ("tcp: Try to restore large SKBs while SACK processing") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-27tcp: bug fix in proportional rate reduction.Nandita Dukkipati1-10/+13
[ Upstream commit 35f079ebbc860dcd1cca70890c9c8d59c1145525 ] This patch is a fix for a bug triggering newly_acked_sacked < 0 in tcp_ack(.). The bug is triggered by sacked_out decreasing relative to prior_sacked, but packets_out remaining the same as pior_packets. This is because the snapshot of prior_packets is taken after tcp_sacktag_write_queue() while prior_sacked is captured before tcp_sacktag_write_queue(). The problem is: tcp_sacktag_write_queue (tcp_match_skb_to_sack() -> tcp_fragment) adjusts the pcount for packets_out and sacked_out (MSS change or other reason). As a result, this delta in pcount is reflected in (prior_sacked - sacked_out) but not in (prior_packets - packets_out). This patch does the following: 1) initializes prior_packets at the start of tcp_ack() so as to capture the delta in packets_out created by tcp_fragment. 2) introduces a new "previous_packets_out" variable that snapshots packets_out right before tcp_clean_rtx_queue, so pkts_acked can be correctly computed as before. 3) Computes pkts_acked using previous_packets_out, and computes newly_acked_sacked using prior_packets. Signed-off-by: Nandita Dukkipati <nanditad@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01tcp: call tcp_replace_ts_recent() from tcp_ack()Eric Dumazet1-33/+32
[ Upstream commit 12fb3dd9dc3c64ba7d64cec977cca9b5fb7b1d4e ] commit bd090dfc634d (tcp: tcp_replace_ts_recent() should not be called from tcp_validate_incoming()) introduced a TS ecr bug in slow path processing. 1 A > B P. 1:10001(10000) ack 1 <nop,nop,TS val 1001 ecr 200> 2 B < A . 1:1(0) ack 1 win 257 <sack 9001:10001,TS val 300 ecr 1001> 3 A > B . 1:1001(1000) ack 1 win 227 <nop,nop,TS val 1002 ecr 200> 4 A > B . 1001:2001(1000) ack 1 win 227 <nop,nop,TS val 1002 ecr 200> (ecr 200 should be ecr 300 in packets 3 & 4) Problem is tcp_ack() can trigger send of new packets (retransmits), reflecting the prior TSval, instead of the TSval contained in the currently processed incoming packet. Fix this by calling tcp_replace_ts_recent() from tcp_ack() after the checks, but before the actions. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05tcp: undo spurious timeout after SACK renegingYuchung Cheng1-5/+2
[ Upstream commit 7ebe183c6d444ef5587d803b64a1f4734b18c564 ] On SACK reneging the sender immediately retransmits and forces a timeout but disables Eifel (undo). If the (buggy) receiver does not drop any packet this can trigger a false slow-start retransmit storm driven by the ACKs of the original packets. This can be detected with undo and TCP timestamps. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-21tcp: fix double-counted receiver RTT when leaving receiver fast pathNeal Cardwell1-3/+3
[ Upstream commit aab2b4bf224ef8358d262f95b568b8ad0cecf0a0 ] We should not update ts_recent and call tcp_rcv_rtt_measure_ts() both before and after going to step5. That wastes CPU and double-counts the receiver-side RTT sample. Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14tcp: fix for zero packets_in_flight was too broadIlpo Järvinen1-2/+6
[ Upstream commit 6731d2095bd4aef18027c72ef845ab1087c3ba63 ] There are transients during normal FRTO procedure during which the packets_in_flight can go to zero between write_queue state updates and firing the resulting segments out. As FRTO processing occurs during that window the check must be more precise to not match "spuriously" :-). More specificly, e.g., when packets_in_flight is zero but FLAG_DATA_ACKED is true the problematic branch that set cwnd into zero would not be taken and new segments might be sent out later. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Tested-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-14tcp: frto should not set snd_cwnd to 0Eric Dumazet1-1/+2
[ Upstream commit 2e5f421211ff76c17130b4597bc06df4eeead24f ] Commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start()) uncovered a bug in FRTO code : tcp_process_frto() is setting snd_cwnd to 0 if the number of in flight packets is 0. As Neal pointed out, if no packet is in flight we lost our chance to disambiguate whether a loss timeout was spurious. We should assume it was a proper loss. Reported-by: Pasi Kärkkäinen <pasik@iki.fi> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11tcp: RFC 5961 5.2 Blind Data Injection Attack MitigationEric Dumazet1-18/+25
[ Upstream commit 354e4aa391ed50a4d827ff6fc11e0667d0859b25 ] RFC 5961 5.2 [Blind Data Injection Attack].[Mitigation] All TCP stacks MAY implement the following mitigation. TCP stacks that implement this mitigation MUST add an additional input check to any incoming segment. The ACK value is considered acceptable only if it is in the range of ((SND.UNA - MAX.SND.WND) <= SEG.ACK <= SND.NXT). All incoming segments whose ACK value doesn't satisfy the above condition MUST be discarded and an ACK sent back. Move tcp_send_challenge_ack() before tcp_ack() to avoid a forward declaration. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Jerry Chu <hkchu@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11tcp: tcp_replace_ts_recent() should not be called from tcp_validate_incoming()Eric Dumazet1-5/+10
[ Upstream commit bd090dfc634ddd711a5fbd0cadc6e0ab4977bcaf ] We added support for RFC 5961 in latest kernels but TCP fails to perform exhaustive check of ACK sequence. We can update our view of peer tsval from a frame that is later discarded by tcp_ack() This makes timestamps enabled sessions vulnerable to injection of a high tsval : peers start an ACK storm, since the victim sends a dupack each time it receives an ACK from the other peer. As tcp_validate_incoming() is called before tcp_ack(), we should not peform tcp_replace_ts_recent() from it, and let callers do it at the right time. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: Romain Francoise <romain@orebokech.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11tcp: refine SYN handling in tcp_validate_incomingEric Dumazet1-1/+5
[ Upstream commit e371589917011efe6ff8c7dfb4e9e81934ac5855 ] Followup of commit 0c24604b68fc (tcp: implement RFC 5961 4.2) As reported by Vijay Subramanian, we should send a challenge ACK instead of a dup ack if a SYN flag is set on a packet received out of window. This permits the ratelimiting to work as intended, and to increase correct SNMP counters. Suggested-by: Vijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11tcp: implement RFC 5961 4.2Eric Dumazet1-17/+15
[ Upstream commit 0c24604b68fc7810d429d6c3657b6f148270e528 ] Implement the RFC 5691 mitigation against Blind Reset attack using SYN bit. Section 4.2 of RFC 5961 advises to send a Challenge ACK and drop incoming packet, instead of resetting the session. Add a new SNMP counter to count number of challenge acks sent in response to SYN packets. (netstat -s | grep TCPSYNChallenge) Remove obsolete TCPAbortOnSyn, since we no longer abort a TCP session because of a SYN flag. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-11tcp: implement RFC 5961 3.2Eric Dumazet1-1/+30
[ Upstream commit 282f23c6ee343126156dd41218b22ece96d747e3 ] Implement the RFC 5691 mitigation against Blind Reset attack using RST bit. Idea is to validate incoming RST sequence, to match RCV.NXT value, instead of previouly accepted window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND) If sequence is in window but not an exact match, send a "challenge ACK", so that the other part can resend an RST with the appropriate sequence. Add a new sysctl, tcp_challenge_ack_limit, to limit number of challenge ACK sent per second. Add a new SNMP counter to count number of challenge acks sent. (netstat -s | grep TCPChallengeACK) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02tcp: fix cwnd reduction for non-sack recoveryYuchung Cheng1-8/+7
[ Upstream commit 7c4a56fec379ac0d7754e0d4da6a7361f1a4fe64 ] The cwnd reduction in fast recovery is based on the number of packets newly delivered per ACK. For non-sack connections every DUPACK signifies a packet has been delivered, but the sender mistakenly skips counting them for cwnd reduction. The fix is to compute newly_acked_sacked after DUPACKs are accounted in sacked_out for non-sack connections. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Nandita Dukkipati <nanditad@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-09tcp: perform DMA to userspace only if there is a task waiting for itJiri Kosina1-1/+3
[ Upstream commit 59ea33a68a9083ac98515e4861c00e71efdc49a1 ] Back in 2006, commit 1a2449a87b ("[I/OAT]: TCP recv offload to I/OAT") added support for receive offloading to IOAT dma engine if available. The code in tcp_rcv_established() tries to perform early DMA copy if applicable. It however does so without checking whether the userspace task is actually expecting the data in the buffer. This is not a problem under normal circumstances, but there is a corner case where this doesn't work -- and that's when MSG_TRUNC flag to recvmsg() is used. If the IOAT dma engine is not used, the code properly checks whether there is a valid ucopy.task and the socket is owned by userspace, but misses the check in the dmaengine case. This problem can be observed in real trivially -- for example 'tbench' is a good reproducer, as it makes a heavy use of MSG_TRUNC. On systems utilizing IOAT, you will soon find tbench waiting indefinitely in sk_wait_data(), as they have been already early-copied in tcp_rcv_established() using dma engine. This patch introduces the same check we are performing in the simple iovec copy case to the IOAT case as well. It fixes the indefinite recvmsg(MSG_TRUNC) hangs. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-03tcp: change tcp_adv_win_scale and tcp_rmem[2]Eric Dumazet1-1/+1
tcp_adv_win_scale default value is 2, meaning we expect a good citizen skb to have skb->len / skb->truesize ratio of 75% (3/4) In 2.6 kernels we (mis)accounted for typical MSS=1460 frame : 1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392. So these skbs were considered as not bloated. With recent truesize fixes, a typical MSS=1460 frame truesize is now the more precise : 2048 + 256 = 2304. But 2304 * 3/4 = 1728. So these skb are not good citizen anymore, because 1460 < 1728 (GRO can escape this problem because it build skbs with a too low truesize.) This also means tcp advertises a too optimistic window for a given allocated rcvspace : When receiving frames, sk_rmem_alloc can hit sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often, especially when application is slow to drain its receive queue or in case of losses (netperf is fast, scp is slow). This is a major latency source. We should adjust the len/truesize ratio to 50% instead of 75% This patch : 1) changes tcp_adv_win_scale default to 1 instead of 2 2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account better truesize tracking and to allow autotuning tcp receive window to reach same value than before. Note that same amount of kernel memory is consumed compared to 2.6 kernels. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-30tcp: fix infinite cwnd in tcp_complete_cwr()Yuchung Cheng1-3/+6
When the cwnd reduction is done, ssthresh may be infinite if TCP enters CWR via ECN or F-RTO. If cwnd is not undone, i.e., undo_marker is set, tcp_complete_cwr() falsely set cwnd to the infinite ssthresh value. The correct operation is to keep cwnd intact because it has been updated in ECN or F-RTO. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-27tcp: clean up use of jiffies in tcp_rcv_rtt_measure()Neal Cardwell1-1/+1
Clean up a reference to jiffies in tcp_rcv_rtt_measure() that should instead reference tcp_time_stamp. Since the result of the subtraction is passed into a function taking u32, this should not change any behavior (and indeed the generated assembly does not change on x86_64). However, it seems worth cleaning this up for consistency and clarity (and perhaps to avoid bugs if this is copied and pasted somewhere else). Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-18tcp: fix tcp_grow_window() for large incoming framesEric Dumazet1-0/+1
tcp_grow_window() has to grow rcv_ssthresh up to window_clamp, allowing sender to increase its window. tcp_grow_window() still assumes a tcp frame is under MSS, but its no longer true with LRO/GRO. This patch fixes one of the performance issue we noticed with GRO on. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-2/+5
Pull networking fixes from David Miller: 1) Fix bluetooth userland regression reported by Keith Packard, from Gustavo Padovan. 2) Revert ath9k PS idle change, from Sujith Manoharan. 3) Correct default TCP memory limits (again), from Eric Dumazet. 4) Fix tcp_rcv_rtt_update() accidental use of unscaled RTT, from Neal Cardwell. 5) We made a facility for layers like wireless to say how much tailroom they need in the SKB for link layer stuff such as wireless encryption etc., but TCP works hard to fill every SKB out to the end defeating this specification. This leads to every TCP packet getting reallocated by the wireless code in order to have the right amount of tailroom available. Fix TCP to only fill SKBs out to the real amount of data area it asked for during the allocation, this way it won't eat into the slack added for the device's tailroom needs. Reported by Marc Merlin and fixed by Eric Dumazet. 6) Leaks, endian bugs, and new device IDs in bluetooth from Santosh Nayak, João Paulo Rechi Vita, Cho, Yu-Chen, Andrei Emeltchenko, AceLan Kao, and Andrei Emeltchenko. 7) OOPS on tty_close fix in bluetooth's hci_ldisc from Johan Hovold. 8) netfilter erroneously scales TCP window twice, fix from Changli Gao. 9) Memleak fix in wext-core from Julia Lawall. 10) Consistently handle invalid TCP packets in ipv4 vs. ipv6 conntrack, from Jozsef Kadlecsik. 11) Validate IP header length properly in netfilter conntrack's ipv4_get_l4proto(). * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (39 commits) NFC: Fix the LLCP Tx fragmentation loop rtlwifi: Add missing DMA buffer unmapping for PCI drivers rtlwifi: Preallocate USB read buffers and eliminate kalloc in read routine tcp: avoid order-1 allocations on wifi and tx path net: allow pskb_expand_head() to get maximum tailroom bridge: Do not send queries on multicast group leaves MAINTAINERS: Mark NATSEMI driver as orphan'd. tcp: fix tcp_rcv_rtt_update() use of an unscaled RTT sample tcp: restore correct limit Revert "ath9k: fix going to full-sleep on PS idle" rt2x00: Fix rfkill_polling register function. bcma: fix build error on MIPS; implicit pcibios_enable_device netfilter: nf_conntrack: fix incorrect logic in nf_conntrack_init_net netfilter: nf_ct_ipv4: packets with wrong ihl are invalid netfilter: nf_ct_ipv4: handle invalid IPv4 and IPv6 packets consistently net/wireless/wext-core.c: add missing kfree rtlwifi: Fix oops on rate-control failure mac80211: Convert WARN_ON to WARN_ON_ONCE rtlwifi: rtl8192de: Fix firmware initialization nl80211: ensure interface is up in various APIs ...
2012-04-11Merge tag 'dmaengine-fixes' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine Pull dmaengine fixes from Dan Williams: 1/ regression fix for Xen as it now trips over a broken assumption about the dma address size on 32-bit builds 2/ new quirk for netdma to ignore dma channels that cannot meet netdma alignment requirements 3/ fixes for two long standing issues in ioatdma (ring size overflow) and iop-adma (potential stack corruption) * tag 'dmaengine-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine: netdma: adding alignment check for NETDMA ops ioatdma: DMA copy alignment needed to address IOAT DMA silicon errata ioat: ring size variables need to be 32bit to avoid overflow iop-adma: Corrected array overflow in RAID6 Xscale(R) test. ioat: fix size of 'completion' for Xen
2012-04-10tcp: fix tcp_rcv_rtt_update() use of an unscaled RTT sampleNeal Cardwell1-2/+5
Fix a code path in tcp_rcv_rtt_update() that was comparing scaled and unscaled RTT samples. The intent in the code was to only use the 'm' measurement if it was a new minimum. However, since 'm' had not yet been shifted left 3 bits but 'new_sample' had, this comparison would nearly always succeed, leading us to erroneously set our receive-side RTT estimate to the 'm' sample when that sample could be nearly 8x too high to use. The overall effect is to often cause the receive-side RTT estimate to be significantly too large (up to 40% too large for brief periods in my tests). Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-06netdma: adding alignment check for NETDMA opsDave Jiang1-1/+1
This is the fallout from adding memcpy alignment workaround for certain IOATDMA hardware. NetDMA will only use DMA engine that can handle byte align ops. Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-03-20tcp: reduce out_of_order memory useEric Dumazet1-1/+18
With increasing receive window sizes, but speed of light not improved that much, out of order queue can contain a huge number of skbs, waiting to be moved to receive_queue when missing packets can fill the holes. Some devices happen to use fat skbs (truesize of 4096 + sizeof(struct sk_buff)) to store regular (MTU <= 1500) frames. This makes highly probable sk_rmem_alloc hits sk_rcvbuf limit, which can be 4Mbytes in many cases. When limit is hit, tcp stack calls tcp_collapse_ofo_queue(), a true latency killer and cpu cache blower. Doing the coalescing attempt each time we add a frame in ofo queue permits to keep memory use tight and in many cases avoid the tcp_collapse() thing later. Tested on various wireless setups (b43, ath9k, ...) known to use big skb truesize, this patch removed the "packets collapsed in receive queue due to low socket buffer" I had before. This also reduced average memory used by tcp sockets. With help from Neal Cardwell. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20tcp: introduce tcp_data_queue_ofoEric Dumazet1-99/+115
Split tcp_data_queue() in two parts for better readability. tcp_data_queue_ofo() is responsible for queueing incoming skb into out of order queue. Change code layout so that the skb_set_owner_r() is performed only if skb is not dropped. This is a preliminary patch before "reduce out_of_order memory use" following patch. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-13net: ipv4: Standardize prefixes for message loggingJoe Perches1-0/+2
Add #define pr_fmt(fmt) as appropriate. Add "IPv4: ", "TCP: ", and "IPsec: " to appropriate files. Standardize on "UDPLite: " for appropriate uses. Some prefixes were previously "UDPLITE: " and "UDP-Lite: ". Add KBUILD_MODNAME ": " to icmp and gre. Remove embedded prefixes as appropriate. Add missing "\n" to pr_info in gre.c. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-12net: Convert printks to pr_<level>Joe Perches1-4/+4
Use a more current kernel messaging style. Convert a printk block to print_hex_dump. Coalesce formats, align arguments. Use %s, __func__ instead of embedding function names. Some messages that were prefixed with <foo>_close are now prefixed with <foo>_fini. Some ah4 and esp messages are now not prefixed with "ip ". The intent of this patch is to later add something like #define pr_fmt(fmt) "IPv4: " fmt. to standardize the output messages. Text size is trivially reduced. (x86-32 allyesconfig) $ size net/ipv4/built-in.o* text data bss dec hex filename 887888 31558 249696 1169142 11d6f6 net/ipv4/built-in.o.new 887934 31558 249800 1169292 11d78c net/ipv4/built-in.o.old Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-06tcp: fix tcp_shift_skb_data() to not shift SACKed data below snd_unaNeal Cardwell1-0/+4
This commit fixes tcp_shift_skb_data() so that it does not shift SACKed data below snd_una. This fixes an issue whose symptoms exactly match reports showing tp->sacked_out going negative since 3.3.0-rc4 (see "WARNING: at net/ipv4/tcp_input.c:3418" thread on netdev). Since 2008 (832d11c5cd076abc0aa1eaf7be96c81d1a59ce41) tcp_shift_skb_data() had been shifting SACKed ranges that were below snd_una. It checked that the *end* of the skb it was about to shift from was above snd_una, but did not check that the end of the actual shifted range was above snd_una; this commit adds that check. Shifting SACKed ranges below snd_una is problematic because for such ranges tcp_sacktag_one() short-circuits: it does not declare anything as SACKed and does not increase sacked_out. Before the fixes in commits cc9a672ee522d4805495b98680f4a3db5d0a0af9 and daef52bab1fd26e24e8e9578f8fb33ba1d0cb412, shifting SACKed ranges below snd_una happened to work because tcp_shifted_skb() was always (incorrectly) passing in to tcp_sacktag_one() an skb whose end_seq tcp_shift_skb_data() had already guaranteed was beyond snd_una. Hence tcp_sacktag_one() never short-circuited and always increased tp->sacked_out in this case. After those two fixes, my testing has verified that shifting SACKed ranges below snd_una could cause tp->sacked_out to go negative with the following sequence of events: (1) tcp_shift_skb_data() sees an skb whose end_seq is beyond snd_una, then shifts a prefix of that skb that is below snd_una (2) tcp_shifted_skb() increments the packet count of the already-SACKed prev sk_buff (3) tcp_sacktag_one() sees the end of the new SACKed range is below snd_una, so it short-circuits and doesn't increase tp->sacked_out (5) tcp_clean_rtx_queue() sees the SACKed skb has been ACKed, decrements tp->sacked_out by this "inflated" pcount that was missing a matching increase in tp->sacked_out, and hence tp->sacked_out underflows to a u32 like 0xFFFFFFFF, which casted to s32 is negative. (6) this leads to the warnings seen in the recent "WARNING: at net/ipv4/tcp_input.c:3418" thread on the netdev list; e.g.: tcp_input.c:3418 WARN_ON((int)tp->sacked_out < 0); More generally, I think this bug can be tickled in some cases where two or more ACKs from the receiver are lost and then a DSACK arrives that is immediately above an existing SACKed skb in the write queue. This fix changes tcp_shift_skb_data() to abort this sequence at step (1) in the scenario above by noticing that the bytes are below snd_una and not shifting them. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-03tcp: don't fragment SACKed skbs in tcp_mark_head_lost()Neal Cardwell1-0/+1
In tcp_mark_head_lost() we should not attempt to fragment a SACKed skb to mark the first portion as lost. This is for two primary reasons: (1) tcp_shifted_skb() coalesces adjacent regions of SACKed skbs. When doing this, it preserves the sum of their packet counts in order to reflect the real-world dynamics on the wire. But given that skbs can have remainders that do not align to MSS boundaries, this packet count preservation means that for SACKed skbs there is not necessarily a direct linear relationship between tcp_skb_pcount(skb) and skb->len. Thus tcp_mark_head_lost()'s previous attempts to fragment off and mark as lost a prefix of length (packets - oldcnt)*mss from SACKed skbs were leading to occasional failures of the WARN_ON(len > skb->len) in tcp_fragment() (which used to be a BUG_ON(); see the recent "crash in tcp_fragment" thread on netdev). (2) there is no real point in fragmenting off part of a SACKed skb and calling tcp_skb_mark_lost() on it, since tcp_skb_mark_lost() is a NOP for SACKed skbs. Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-29tcp: fix false reordering signal in tcp_shifted_skbNeal Cardwell1-8/+10
When tcp_shifted_skb() shifts bytes from the skb that is currently pointed to by 'highest_sack' then the increment of TCP_SKB_CB(skb)->seq implicitly advances tcp_highest_sack_seq(). This implicit advancement, combined with the recent fix to pass the correct SACKed range into tcp_sacktag_one(), caused tcp_sacktag_one() to think that the newly SACKed range was before the tcp_highest_sack_seq(), leading to a call to tcp_update_reordering() with a degree of reordering matching the size of the newly SACKed range (typically just 1 packet, which is a NOP, but potentially larger). This commit fixes this by simply calling tcp_sacktag_one() before the TCP_SKB_CB(skb)->seq advancement that can advance our notion of the highest SACKed sequence. Correspondingly, we can simplify the code a little now that tcp_shifted_skb() should update the lost_cnt_hint in all cases where skb == tp->lost_skb_hint. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-14tcp: fix tcp_shifted_skb() adjustment of lost_cnt_hint for FACKNeal Cardwell1-0/+4
This commit ensures that lost_cnt_hint is correctly updated in tcp_shifted_skb() for FACK TCP senders. The lost_cnt_hint adjustment in tcp_sacktag_one() only applies to non-FACK senders, so FACK senders need their own adjustment. This applies the spirit of 1e5289e121372a3494402b1b131b41bfe1cf9b7f - except now that the sequence range passed into tcp_sacktag_one() is correct we need only have a special case adjustment for FACK. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-13tcp: fix range tcp_shifted_skb() passes to tcp_sacktag_one()Neal Cardwell1-9/+10
Fix the newly-SACKed range to be the range of newly-shifted bytes. Previously - since 832d11c5cd076abc0aa1eaf7be96c81d1a59ce41 - tcp_shifted_skb() incorrectly called tcp_sacktag_one() with the start and end sequence numbers of the skb it passes in set to the range just beyond the range that is newly-SACKed. This commit also removes a special-case adjustment to lost_cnt_hint in tcp_shifted_skb() since the pre-existing adjustment of lost_cnt_hint in tcp_sacktag_one() now properly handles this things now that the correct start sequence number is passed in. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-13tcp: allow tcp_sacktag_one() to tag ranges not aligned with skbsNeal Cardwell1-14/+22
This commit allows callers of tcp_sacktag_one() to pass in sequence ranges that do not align with skb boundaries, as tcp_shifted_skb() needs to do in an upcoming fix in this patch series. In fact, now tcp_sacktag_one() does not need to depend on an input skb at all, which makes its semantics and dependencies more clear. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-23tcp: detect loss above high_seq in recoveryYuchung Cheng1-26/+15
Correctly implement a loss detection heuristic: New sequences (above high_seq) sent during the fast recovery are deemed lost when higher sequences are SACKed. Current code does not catch these losses, because tcp_mark_head_lost() does not check packets beyond high_seq. The fix is straight-forward by checking packets until the highest sacked packet. In addition, all the FLAG_DATA_LOST logic are in-effective and redundant and can be removed. Update the loss heuristic comments. The algorithm above is documented as heuristic B, but it is redundant too because heuristic A already covers B. Note that this change only marks some forward-retransmitted packets LOST. It does NOT forbid TCP performing further CWR on new losses. A potential follow-up patch under preparation is to perform another CWR on "new" losses such as 1) sequence above high_seq is lost (by resetting high_seq to snd_nxt) 2) retransmission is lost. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-21tcp: Replace constants with #define macrosVijay Subramanian1-3/+3
to record the state of SACK/FACK and DSACK for better readability and maintenance. Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-13foundations of per-cgroup memory pressure controlling.Glauber Costa1-6/+6
This patch replaces all uses of struct sock fields' memory_pressure, memory_allocated, sockets_allocated, and sysctl_mem to acessor macros. Those macros can either receive a socket argument, or a mem_cgroup argument, depending on the context they live in. Since we're only doing a macro wrapping here, no performance impact at all is expected in the case where we don't have cgroups disabled. Signed-off-by: Glauber Costa <glommer@parallels.com> Reviewed-by: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com> CC: David S. Miller <davem@davemloft.net> CC: Eric W. Biederman <ebiederm@xmission.com> CC: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-12net: use IS_ENABLED(CONFIG_IPV6)Eric Dumazet1-1/+1
Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-04tcp: drop SYN+FIN messagesEric Dumazet1-0/+2
Denys Fedoryshchenko reported that SYN+FIN attacks were bringing his linux machines to their limits. Dont call conn_request() if the TCP flags includes SYN flag Reported-by: Denys Fedoryshchenko <denys@visp.net.lb> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-28tcp: skip cwnd moderation in TCP_CA_Open in tcp_try_to_openNeal Cardwell1-1/+2
The problem: Senders were overriding cwnd values picked during an undo by calling tcp_moderate_cwnd() in tcp_try_to_open(). The fix: Don't moderate cwnd in tcp_try_to_open() if we're in TCP_CA_Open, since doing so is generally unnecessary and specifically would override a DSACK-based undo of a cwnd reduction made in fast recovery. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-28tcp: allow undo from reordered DSACKsNeal Cardwell1-13/+2
Previously, SACK-enabled connections hung around in TCP_CA_Disorder state while snd_una==high_seq, just waiting to accumulate DSACKs and hopefully undo a cwnd reduction. This could and did lead to the following unfortunate scenario: if some incoming ACKs advance snd_una beyond high_seq then we were setting undo_marker to 0 and moving to TCP_CA_Open, so if (due to reordering in the ACK return path) we shortly thereafter received a DSACK then we were no longer able to undo the cwnd reduction. The change: Simplify the congestion avoidance state machine by removing the behavior where SACK-enabled connections hung around in the TCP_CA_Disorder state just waiting for DSACKs. Instead, when snd_una advances to high_seq or beyond we typically move to TCP_CA_Open immediately and allow an undo in either TCP_CA_Open or TCP_CA_Disorder if we later receive enough DSACKs. Other patches in this series will provide other changes that are necessary to fully fix this problem. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-28tcp: use SACKs and DSACKs that arrive on ACKs below snd_unaNeal Cardwell1-3/+7
The bug: When the ACK field is below snd_una (which can happen when ACKs are reordered), senders ignored DSACKs (preventing undo) and did not call tcp_fastretrans_alert, so they did not increment prr_delivered to reflect newly-SACKed sequence ranges, and did not call tcp_xmit_retransmit_queue, thus passing up chances to send out more retransmitted and new packets based on any newly-SACKed packets. The change: When the ACK field is below snd_una (the "old_ack" goto label), call tcp_fastretrans_alert to allow undo based on any newly-arrived DSACKs and try to send out more packets based on newly-SACKed packets. Other patches in this series will provide other changes that are necessary to fully fix this problem. Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-28tcp: use DSACKs that arrive when packets_out is 0Neal Cardwell1-0/+4
The bug: Senders ignored DSACKs after recovery when there were no outstanding packets (a common scenario for HTTP servers). The change: when there are no outstanding packets (the "no_queue" goto label), call tcp_fastretrans_alert() in order to use DSACKs to undo congestion window reductions. Other patches in this series will provide other changes that are necessary to fully fix this problem. Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-28tcp: make is_dupack a parameter to tcp_fastretrans_alert()Neal Cardwell1-4/+8
Allow callers to decide whether an ACK is a duplicate ACK. This is a prerequisite to allowing fastretrans_alert to be called from new contexts, such as the no_queue and old_ack code paths, from which we have extra info that tells us whether an ACK is a dupack. Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-21tcp: add const qualifiers where possibleEric Dumazet1-54/+56
Adding const qualifiers to pointers can ease code review, and spot some bugs. It might allow compiler to optimize code further. For example, is it legal to temporary write a null cksum into tcphdr in tcp_md5_hash_header() ? I am afraid a sniffer could catch the temporary null value... Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-21tcp: remove unused tcp_fin() parametersEric Dumazet1-3/+3
tcp_fin() only needs socket pointer, we can remove skb and th params. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-21tcp: use TCP_DEFAULT_INIT_RCVWND in tcp_fixup_rcvbuf()Eric Dumazet1-8/+15
Since commit 356f039822b (TCP: increase default initial receive window.), we allow sender to send 10 (TCP_DEFAULT_INIT_RCVWND) segments. Change tcp_fixup_rcvbuf() to reflect this change, even if no real change is expected, since sysctl_tcp_rmem[1] = 87380 and this value is bigger than tcp_fixup_rcvbuf() computed rcvmem (~23720) Note: Since commit 356f039822b limited default window to maximum of 10*1460 and 2*MSS, we use same heuristic in this patch. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-20tcp: use TCP_INIT_CWND in tcp_fixup_sndbuf()Eric Dumazet1-5/+3
Initial cwnd being 10 (TCP_INIT_CWND) instead of 3, change tcp_fixup_sndbuf() to get more than 16384 bytes (sysctl_tcp_wmem[1]) in initial sk_sndbuf Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-14net: more accurate skb truesizeEric Dumazet1-7/+7
skb truesize currently accounts for sk_buff struct and part of skb head. kmalloc() roundings are also ignored. Considering that skb_shared_info is larger than sk_buff, its time to take it into account for better memory accounting. This patch introduces SKB_TRUESIZE(X) macro to centralize various assumptions into a single place. At skb alloc phase, we put skb_shared_info struct at the exact end of skb head, to allow a better use of memory (lowering number of reallocations), since kmalloc() gives us power-of-two memory blocks. Unless SLUB/SLUB debug is active, both skb->head and skb_shared_info are aligned to cache lines, as before. Note: This patch might trigger performance regressions because of misconfigured protocol stacks, hitting per socket or global memory limits that were previously not reached. But its a necessary step for a more accurate memory accounting. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Andi Kleen <ak@linux.intel.com> CC: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-07Merge branch 'master' of github.com:davem330/netDavid S. Miller1-3/+1
Conflicts: net/batman-adv/soft-interface.c
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-24 09:23:05 +0300