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* tcp: Add listening address to SYN flood messageJamie Bainbridge2022-11-141-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | The SYN flood message prints the listening port number, but with many processes bound to the same port on different IPs, it's impossible to tell which socket is the problem. Add the listen IP address to the SYN flood message. For IPv6 use "[IP]:port" as per RFC-5952 and to provide ease of copy-paste to "ss" filters. For IPv4 use "IP:port" to match. Each protcol's "any" address and a host address now look like: Possible SYN flooding on port 0.0.0.0:9001. Possible SYN flooding on port 127.0.0.1:9001. Possible SYN flooding on port [::]:9001. Possible SYN flooding on port [fc00::1]:9001. Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Stephen Hemminger <stephen@networkplumber.org> Link: https://lore.kernel.org/r/4fedab7ce54a389aeadbdc639f6b4f4988e9d2d7.1668386107.git.jamie.bainbridge@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: refine tcp_prune_ofo_queue() logicEric Dumazet2022-11-011-20/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After commits 36a6503fedda ("tcp: refine tcp_prune_ofo_queue() to not drop all packets") and 72cd43ba64fc1 ("tcp: free batches of packets in tcp_prune_ofo_queue()") tcp_prune_ofo_queue() drops a fraction of ooo queue, to make room for incoming packet. However it makes no sense to drop packets that are before the incoming packet, in sequence space. In order to recover from packet losses faster, it makes more sense to only drop ooo packets which are after the incoming packet. Tested: packetdrill test: 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [3800], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 0> +.1 < . 1:1(0) ack 1 win 1024 +0 accept(3, ..., ...) = 4 +.01 < . 200:300(100) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 200:300> +.01 < . 400:500(100) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 400:500 200:300> +.01 < . 600:700(100) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 600:700 400:500 200:300> +.01 < . 800:900(100) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 800:900 600:700 400:500 200:300> +.01 < . 1000:1100(100) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 1000:1100 800:900 600:700 400:500> +.01 < . 1200:1300(100) ack 1 win 1024 +0 > . 1:1(0) ack 1 <nop,nop, sack 1200:1300 1000:1100 800:900 600:700> // this packet is dropped because we have no room left. +.01 < . 1400:1500(100) ack 1 win 1024 +.01 < . 1:200(199) ack 1 win 1024 // Make sure kernel did not drop 200:300 sequence +0 > . 1:1(0) ack 300 <nop,nop, sack 1200:1300 1000:1100 800:900 600:700> // Make room, since our RCVBUF is very small +0 read(4, ..., 299) = 299 +.01 < . 300:400(100) ack 1 win 1024 +0 > . 1:1(0) ack 500 <nop,nop, sack 1200:1300 1000:1100 800:900 600:700> +.01 < . 500:600(100) ack 1 win 1024 +0 > . 1:1(0) ack 700 <nop,nop, sack 1200:1300 1000:1100 800:900> +0 read(4, ..., 400) = 400 +.01 < . 700:800(100) ack 1 win 1024 +0 > . 1:1(0) ack 900 <nop,nop, sack 1200:1300 1000:1100> +.01 < . 900:1000(100) ack 1 win 1024 +0 > . 1:1(0) ack 1100 <nop,nop, sack 1200:1300> +.01 < . 1100:1200(100) ack 1 win 1024 // This checks that 1200:1300 has not been removed from ooo queue +0 > . 1:1(0) ack 1300 Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20221101035234.3910189-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: fix indefinite deferral of RTO with SACK renegingNeal Cardwell2022-10-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fixes a bug that can cause a TCP data sender to repeatedly defer RTOs when encountering SACK reneging. The bug is that when we're in fast recovery in a scenario with SACK reneging, every time we get an ACK we call tcp_check_sack_reneging() and it can note the apparent SACK reneging and rearm the RTO timer for srtt/2 into the future. In some SACK reneging scenarios that can happen repeatedly until the receive window fills up, at which point the sender can't send any more, the ACKs stop arriving, and the RTO fires at srtt/2 after the last ACK. But that can take far too long (O(10 secs)), since the connection is stuck in fast recovery with a low cwnd that cannot grow beyond ssthresh, even if more bandwidth is available. This fix changes the logic in tcp_check_sack_reneging() to only rearm the RTO timer if data is cumulatively ACKed, indicating forward progress. This avoids this kind of nearly infinite loop of RTO timer re-arming. In addition, this meets the goals of tcp_check_sack_reneging() in handling Windows TCP behavior that looks temporarily like SACK reneging but is not really. Many thanks to Jakub Kicinski and Neil Spring, who reported this issue and provided critical packet traces that enabled root-causing this issue. Also, many thanks to Jakub Kicinski for testing this fix. Fixes: 5ae344c949e7 ("tcp: reduce spurious retransmits due to transient SACK reneging") Reported-by: Jakub Kicinski <kuba@kernel.org> Reported-by: Neil Spring <ntspring@fb.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Tested-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20221021170821.1093930-1-ncardwell.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: fix early ETIMEDOUT after spurious non-SACK RTONeal Cardwell2022-09-061-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a bug reported and analyzed by Nagaraj Arankal, where the handling of a spurious non-SACK RTO could cause a connection to fail to clear retrans_stamp, causing a later RTO to very prematurely time out the connection with ETIMEDOUT. Here is the buggy scenario, expanding upon Nagaraj Arankal's excellent report: (*1) Send one data packet on a non-SACK connection (*2) Because no ACK packet is received, the packet is retransmitted and we enter CA_Loss; but this retransmission is spurious. (*3) The ACK for the original data is received. The transmitted packet is acknowledged. The TCP timestamp is before the retrans_stamp, so tcp_may_undo() returns true, and tcp_try_undo_loss() returns true without changing state to Open (because tcp_is_sack() is false), and tcp_process_loss() returns without calling tcp_try_undo_recovery(). Normally after undoing a CA_Loss episode, tcp_fastretrans_alert() would see that the connection has returned to CA_Open and fall through and call tcp_try_to_open(), which would set retrans_stamp to 0. However, for non-SACK connections we hold the connection in CA_Loss, so do not fall through to call tcp_try_to_open() and do not set retrans_stamp to 0. So retrans_stamp is (erroneously) still non-zero. At this point the first "retransmission event" has passed and been recovered from. Any future retransmission is a completely new "event". However, retrans_stamp is erroneously still set. (And we are still in CA_Loss, which is correct.) (*4) After 16 minutes (to correspond with tcp_retries2=15), a new data packet is sent. Note: No data is transmitted between (*3) and (*4) and we disabled keep alives. The socket's timeout SHOULD be calculated from this point in time, but instead it's calculated from the prior "event" 16 minutes ago (step (*2)). (*5) Because no ACK packet is received, the packet is retransmitted. (*6) At the time of the 2nd retransmission, the socket returns ETIMEDOUT, prematurely, because retrans_stamp is (erroneously) too far in the past (set at the time of (*2)). This commit fixes this bug by ensuring that we reuse in tcp_try_undo_loss() the same careful logic for non-SACK connections that we have in tcp_try_undo_recovery(). To avoid duplicating logic, we factor out that logic into a new tcp_is_non_sack_preventing_reopen() helper and call that helper from both undo functions. Fixes: da34ac7626b5 ("tcp: only undo on partial ACKs in CA_Loss") Reported-by: Nagaraj Arankal <nagaraj.p.arankal@hpe.com> Link: https://lore.kernel.org/all/SJ0PR84MB1847BE6C24D274C46A1B9B0EB27A9@SJ0PR84MB1847.NAMPRD84.PROD.OUTLOOK.COM/ Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220903121023.866900-1-ncardwell.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* tcp: make global challenge ack rate limitation per net-ns and default disabledEric Dumazet2022-08-311-10/+11
| | | | | | | | | | | | | | | | | Because per host rate limiting has been proven problematic (side channel attacks can be based on it), per host rate limiting of challenge acks ideally should be per netns and turned off by default. This is a long due followup of following commits: 083ae308280d ("tcp: enable per-socket rate limiting of all 'challenge acks'") f2b2c582e824 ("tcp: mitigate ACK loops for connections as tcp_sock") 75ff39ccc1bd ("tcp: make challenge acks less predictable") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jason Baron <jbaron@akamai.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: annotate data-race around challenge_timestampEric Dumazet2022-08-311-2/+2
| | | | | | | | | | | | | | | challenge_timestamp can be read an written by concurrent threads. This was expected, but we need to annotate the race to avoid potential issues. Following patch moves challenge_timestamp and challenge_count to per-netns storage to provide better isolation. Fixes: 354e4aa391ed ("tcp: RFC 5961 5.2 Blind Data Injection Attack Mitigation") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-07-281-19/+22
|\ | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * tcp: Fix a data-race around sysctl_tcp_comp_sack_nr.Kuniyuki Iwashima2022-07-251-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_comp_sack_nr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 9c21d2fc41c0 ("tcp: add tcp_comp_sack_nr sysctl") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_comp_sack_slack_ns.Kuniyuki Iwashima2022-07-251-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_comp_sack_slack_ns, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: a70437cc09a1 ("tcp: add hrtimer slack to sack compression") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_comp_sack_delay_ns.Kuniyuki Iwashima2022-07-251-1/+2
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_comp_sack_delay_ns, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 6d82aa242092 ("tcp: add tcp_comp_sack_delay_ns sysctl") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Fix data-races around sysctl_[rw]mem(_offset)?.Kuniyuki Iwashima2022-07-251-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While reading these sysctl variables, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. - .sysctl_rmem - .sysctl_rwmem - .sysctl_rmem_offset - .sysctl_wmem_offset - sysctl_tcp_rmem[1, 2] - sysctl_tcp_wmem[1, 2] - sysctl_decnet_rmem[1] - sysctl_decnet_wmem[1] - sysctl_tipc_rmem[1] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sk_pacing_rate.Kuniyuki Iwashima2022-07-251-2/+2
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_pacing_(ss|ca)_ratio, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. Fixes: 43e122b014c9 ("tcp: refine pacing rate determination") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_invalid_ratelimit.Kuniyuki Iwashima2022-07-221-1/+2
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_invalid_ratelimit, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 032ee4236954 ("tcp: helpers to mitigate ACK loops by rate-limiting out-of-window dupacks") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_min_rtt_wlen.Kuniyuki Iwashima2022-07-221-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_min_rtt_wlen, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: f672258391b4 ("tcp: track min RTT using windowed min-filter") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_challenge_ack_limit.Kuniyuki Iwashima2022-07-221-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_challenge_ack_limit, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 282f23c6ee34 ("tcp: implement RFC 5961 3.2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl_tcp_moderate_rcvbuf.Kuniyuki Iwashima2022-07-221-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_moderate_rcvbuf, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_frto.Kuniyuki Iwashima2022-07-221-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_frto, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_app_win.Kuniyuki Iwashima2022-07-221-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_app_win, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl_tcp_dsack.Kuniyuki Iwashima2022-07-221-2/+2
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_dsack, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-07-211-20/+31
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * tcp: Fix data-races around sysctl_tcp_max_reordering.Kuniyuki Iwashima2022-07-201-2/+2
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_max_reordering, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: dca145ffaa8d ("tcp: allow for bigger reordering level") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix a data-race around sysctl_tcp_stdurg.Kuniyuki Iwashima2022-07-201-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_stdurg, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl_tcp_recovery.Kuniyuki Iwashima2022-07-201-1/+2
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_recovery, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 4f41b1c58a32 ("tcp: use RACK to detect losses") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl knobs related to SYN option.Kuniyuki Iwashima2022-07-201-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | While reading these knobs, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. - tcp_sack - tcp_window_scaling - tcp_timestamps Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl_max_syn_backlog.Kuniyuki Iwashima2022-07-181-2/+4
| | | | | | | | | | | | | | | | | | While reading sysctl_max_syn_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl_tcp_reordering.Kuniyuki Iwashima2022-07-181-3/+7
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_reordering, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: Fix data-races around sysctl_tcp_syncookies.Kuniyuki Iwashima2022-07-181-8/+12
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_syncookies, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-07-141-1/+1
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | include/net/sock.h 310731e2f161 ("net: Fix data-races around sysctl_mem.") e70f3c701276 ("Revert "net: set SK_MEM_QUANTUM to 4096"") https://lore.kernel.org/all/20220711120211.7c8b7cba@canb.auug.org.au/ net/ipv4/fib_semantics.c 747c14307214 ("ip: fix dflt addr selection for connected nexthop") d62607c3fe45 ("net: rename reference+tracking helpers") net/tls/tls.h include/net/tls.h 3d8c51b25a23 ("net/tls: Check for errors in tls_device_init") 587903142308 ("tls: create an internal header") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * tcp: Fix data-races around sysctl_tcp_ecn.Kuniyuki Iwashima2022-07-131-1/+1
| | | | | | | | | | | | | | | | | | While reading sysctl_tcp_ecn, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2022-06-171-1/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2022-06-17 We've added 72 non-merge commits during the last 15 day(s) which contain a total of 92 files changed, 4582 insertions(+), 834 deletions(-). The main changes are: 1) Add 64 bit enum value support to BTF, from Yonghong Song. 2) Implement support for sleepable BPF uprobe programs, from Delyan Kratunov. 3) Add new BPF helpers to issue and check TCP SYN cookies without binding to a socket especially useful in synproxy scenarios, from Maxim Mikityanskiy. 4) Fix libbpf's internal USDT address translation logic for shared libraries as well as uprobe's symbol file offset calculation, from Andrii Nakryiko. 5) Extend libbpf to provide an API for textual representation of the various map/prog/attach/link types and use it in bpftool, from Daniel Müller. 6) Provide BTF line info for RV64 and RV32 JITs, and fix a put_user bug in the core seen in 32 bit when storing BPF function addresses, from Pu Lehui. 7) Fix libbpf's BTF pointer size guessing by adding a list of various aliases for 'long' types, from Douglas Raillard. 8) Fix bpftool to readd setting rlimit since probing for memcg-based accounting has been unreliable and caused a regression on COS, from Quentin Monnet. 9) Fix UAF in BPF cgroup's effective program computation triggered upon BPF link detachment, from Tadeusz Struk. 10) Fix bpftool build bootstrapping during cross compilation which was pointing to the wrong AR process, from Shahab Vahedi. 11) Fix logic bug in libbpf's is_pow_of_2 implementation, from Yuze Chi. 12) BPF hash map optimization to avoid grabbing spinlocks of all CPUs when there is no free element. Also add a benchmark as reproducer, from Feng Zhou. 13) Fix bpftool's codegen to bail out when there's no BTF, from Michael Mullin. 14) Various minor cleanup and improvements all over the place. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (72 commits) bpf: Fix bpf_skc_lookup comment wrt. return type bpf: Fix non-static bpf_func_proto struct definitions selftests/bpf: Don't force lld on non-x86 architectures selftests/bpf: Add selftests for raw syncookie helpers in TC mode bpf: Allow the new syncookie helpers to work with SKBs selftests/bpf: Add selftests for raw syncookie helpers bpf: Add helpers to issue and check SYN cookies in XDP bpf: Allow helpers to accept pointers with a fixed size bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie selftests/bpf: add tests for sleepable (uk)probes libbpf: add support for sleepable uprobe programs bpf: allow sleepable uprobe programs to attach bpf: implement sleepable uprobes by chaining gps bpf: move bpf_prog to bpf.h libbpf: Fix internal USDT address translation logic for shared libraries samples/bpf: Check detach prog exist or not in xdp_fwd selftests/bpf: Avoid skipping certain subtests selftests/bpf: Fix test_varlen verification failure with latest llvm bpftool: Do not check return value from libbpf_set_strict_mode() Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK" ... ==================== Link: https://lore.kernel.org/r/20220617220836.7373-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * | bpf: Add helpers to issue and check SYN cookies in XDPMaxim Mikityanskiy2022-06-161-1/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The new helpers bpf_tcp_raw_{gen,check}_syncookie_ipv{4,6} allow an XDP program to generate SYN cookies in response to TCP SYN packets and to check those cookies upon receiving the first ACK packet (the final packet of the TCP handshake). Unlike bpf_tcp_{gen,check}_syncookie these new helpers don't need a listening socket on the local machine, which allows to use them together with synproxy to accelerate SYN cookie generation. Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com> Link: https://lore.kernel.org/r/20220615134847.3753567-4-maximmi@nvidia.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | net: keep sk->sk_forward_alloc as small as possibleEric Dumazet2022-06-101-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, tcp_memory_allocated can hit tcp_mem[] limits quite fast. Each TCP socket can forward allocate up to 2 MB of memory, even after flow became less active. 10,000 sockets can have reserved 20 GB of memory, and we have no shrinker in place to reclaim that. Instead of trying to reclaim the extra allocations in some places, just keep sk->sk_forward_alloc values as small as possible. This should not impact performance too much now we have per-cpu reserves: Changes to tcp_memory_allocated should not be too frequent. For sockets not using SO_RESERVE_MEM: - idle sockets (no packets in tx/rx queues) have zero forward alloc. - non idle sockets have a forward alloc smaller than one page. Note: - Removal of SK_RECLAIM_CHUNK and SK_RECLAIM_THRESHOLD is left to MPTCP maintainers as a follow up. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: remove SK_MEM_QUANTUM and SK_MEM_QUANTUM_SHIFTEric Dumazet2022-06-101-1/+1
|/ | | | | | | | | | | | Due to memcg interface, SK_MEM_QUANTUM is effectively PAGE_SIZE. This might change in the future, but it seems better to avoid the confusion. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: fix tcp_mtup_probe_success vs wrong snd_cwndEric Dumazet2022-05-281-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot got a new report [1] finally pointing to a very old bug, added in initial support for MTU probing. tcp_mtu_probe() has checks about starting an MTU probe if tcp_snd_cwnd(tp) >= 11. But nothing prevents tcp_snd_cwnd(tp) to be reduced later and before the MTU probe succeeds. This bug would lead to potential zero-divides. Debugging added in commit 40570375356c ("tcp: add accessors to read/set tp->snd_cwnd") has paid off :) While we are at it, address potential overflows in this code. [1] WARNING: CPU: 1 PID: 14132 at include/net/tcp.h:1219 tcp_mtup_probe_success+0x366/0x570 net/ipv4/tcp_input.c:2712 Modules linked in: CPU: 1 PID: 14132 Comm: syz-executor.2 Not tainted 5.18.0-syzkaller-07857-gbabf0bb978e3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tcp_snd_cwnd_set include/net/tcp.h:1219 [inline] RIP: 0010:tcp_mtup_probe_success+0x366/0x570 net/ipv4/tcp_input.c:2712 Code: 74 08 48 89 ef e8 da 80 17 f9 48 8b 45 00 65 48 ff 80 80 03 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 aa b0 c5 f8 <0f> 0b e9 16 fe ff ff 48 8b 4c 24 08 80 e1 07 38 c1 0f 8c c7 fc ff RSP: 0018:ffffc900079e70f8 EFLAGS: 00010287 RAX: ffffffff88c0f7f6 RBX: ffff8880756e7a80 RCX: 0000000000040000 RDX: ffffc9000c6c4000 RSI: 0000000000031f9e RDI: 0000000000031f9f RBP: 0000000000000000 R08: ffffffff88c0f606 R09: ffffc900079e7520 R10: ffffed101011226d R11: 1ffff1101011226c R12: 1ffff1100eadcf50 R13: ffff8880756e72c0 R14: 1ffff1100eadcf89 R15: dffffc0000000000 FS: 00007f643236e700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1ab3f1e2a0 CR3: 0000000064fe7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> tcp_clean_rtx_queue+0x223a/0x2da0 net/ipv4/tcp_input.c:3356 tcp_ack+0x1962/0x3c90 net/ipv4/tcp_input.c:3861 tcp_rcv_established+0x7c8/0x1ac0 net/ipv4/tcp_input.c:5973 tcp_v6_do_rcv+0x57b/0x1210 net/ipv6/tcp_ipv6.c:1476 sk_backlog_rcv include/net/sock.h:1061 [inline] __release_sock+0x1d8/0x4c0 net/core/sock.c:2849 release_sock+0x5d/0x1c0 net/core/sock.c:3404 sk_stream_wait_memory+0x700/0xdc0 net/core/stream.c:145 tcp_sendmsg_locked+0x111d/0x3fc0 net/ipv4/tcp.c:1410 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1448 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] __sys_sendto+0x439/0x5c0 net/socket.c:2119 __do_sys_sendto net/socket.c:2131 [inline] __se_sys_sendto net/socket.c:2127 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2127 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f6431289109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f643236e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f643139c100 RCX: 00007f6431289109 RDX: 00000000d0d0c2ac RSI: 0000000020000080 RDI: 000000000000000a RBP: 00007f64312e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff372533af R14: 00007f643236e300 R15: 0000000000022000 Fixes: 5d424d5a674f ("[TCP]: MTU probing") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: improve PRR loss recoveryYuchung Cheng2022-05-191-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | This patch improves TCP PRR loss recovery behavior for a corner case. Previously during PRR conservation-bound mode, it strictly sends the amount equals to the amount newly acked or s/acked. The patch changes s.t. PRR may send additional amount that was banked previously (e.g. application-limited) in the conservation-bound mode, similar to the slow-start mode. This unifies and simplifies the algorithm further and may improve the recovery latency. This change still follow the general packet conservation design principle and always keep inflight/cwnd below the slow start threshold set by the congestion control module. PRR is described in RFC 6937. We'll include this change in the latest revision rfc6937-bis as well. Reported-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220519003410.2531936-1-ycheng@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* tcp: drop skb dst in tcp_rcv_established()Eric Dumazet2022-04-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit f84af32cbca7 ("net: ip_queue_rcv_skb() helper") I dropped the skb dst in tcp_data_queue(). This only dealt with so-called TCP input slow path. When fast path is taken, tcp_rcv_established() calls tcp_queue_rcv() while skb still has a dst. This was mostly fine, because most dsts at this point are not refcounted (thanks to early demux) However, TCP packets sent over loopback have refcounted dst. Then commit 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") came and had the effect of delaying skb freeing for an arbitrary time. If during this time the involved netns is dismantled, cleanup_net() frees the struct net with embedded net->ipv6.ip6_dst_ops. Then when eventually dst_destroy_rcu() is called, if (dst->ops->destroy) ... triggers an use-after-free. It is not clear if ip6_route_net_exit() lacks a rcu_barrier() as syzbot reported similar issues before the blamed commit. ( https://groups.google.com/g/syzkaller-bugs/c/CofzW4eeA9A/m/009WjumTAAAJ ) Fixes: 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-04-281-2/+13
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | include/linux/netdevice.h net/core/dev.c 6510ea973d8d ("net: Use this_cpu_inc() to increment net->core_stats") 794c24e9921f ("net-core: rx_otherhost_dropped to core_stats") https://lore.kernel.org/all/20220428111903.5f4304e0@canb.auug.org.au/ drivers/net/wan/cosa.c d48fea8401cf ("net: cosa: fix error check return value of register_chrdev()") 89fbca3307d4 ("net: wan: remove support for COSA and SRP synchronous serial boards") https://lore.kernel.org/all/20220428112130.1f689e5e@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * tcp: fix F-RTO may not work correctly when receiving DSACKPengcheng Yang2022-04-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently DSACK is regarded as a dupack, which may cause F-RTO to incorrectly enter "loss was real" when receiving DSACK. Packetdrill to demonstrate: // Enable F-RTO and TLP 0 `sysctl -q net.ipv4.tcp_frto=2` 0 `sysctl -q net.ipv4.tcp_early_retrans=3` 0 `sysctl -q net.ipv4.tcp_congestion_control=cubic` // Establish a connection +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 // RTT 10ms, RTO 210ms +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> +0 > S. 0:0(0) ack 1 <...> +.01 < . 1:1(0) ack 1 win 257 +0 accept(3, ..., ...) = 4 // Send 2 data segments +0 write(4, ..., 2000) = 2000 +0 > P. 1:2001(2000) ack 1 // TLP +.022 > P. 1001:2001(1000) ack 1 // Continue to send 8 data segments +0 write(4, ..., 10000) = 10000 +0 > P. 2001:10001(8000) ack 1 // RTO +.188 > . 1:1001(1000) ack 1 // The original data is acked and new data is sent(F-RTO step 2.b) +0 < . 1:1(0) ack 2001 win 257 +0 > P. 10001:12001(2000) ack 1 // D-SACK caused by TLP is regarded as a dupack, this results in // the incorrect judgment of "loss was real"(F-RTO step 3.a) +.022 < . 1:1(0) ack 2001 win 257 <sack 1001:2001,nop,nop> // Never-retransmitted data(3001:4001) are acked and // expect to switch to open state(F-RTO step 3.b) +0 < . 1:1(0) ack 4001 win 257 +0 %{ assert tcpi_ca_state == 0, tcpi_ca_state }% Fixes: e33099f96d99 ("tcp: implement RFC5682 F-RTO") Signed-off-by: Pengcheng Yang <yangpc@wangsu.com> Acked-by: Neal Cardwell <ncardwell@google.com> Tested-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/1650967419-2150-1-git-send-email-yangpc@wangsu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * tcp: fix potential xmit stalls caused by TCP_NOTSENT_LOWATEric Dumazet2022-04-251-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I had this bug sitting for too long in my pile, it is time to fix it. Thanks to Doug Porter for reminding me of it! We had various attempts in the past, including commit 0cbe6a8f089e ("tcp: remove SOCK_QUEUE_SHRUNK"), but the issue is that TCP stack currently only generates EPOLLOUT from input path, when tp->snd_una has advanced and skb(s) cleaned from rtx queue. If a flow has a big RTT, and/or receives SACKs, it is possible that the notsent part (tp->write_seq - tp->snd_nxt) reaches 0 and no more data can be sent until tp->snd_una finally advances. What is needed is to also check if POLLOUT needs to be generated whenever tp->snd_nxt is advanced, from output path. This bug triggers more often after an idle period, as we do not receive ACK for at least one RTT. tcp_notsent_lowat could be a fraction of what CWND and pacing rate would allow to send during this RTT. In a followup patch, I will remove the bogus call to tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED) from tcp_check_space(). Fact that we have decided to generate an EPOLLOUT does not mean the application has immediately refilled the transmit queue. This optimistic call might have been the reason the bug seemed not too serious. Tested: 200 ms rtt, 1% packet loss, 32 MB tcp_rmem[2] and tcp_wmem[2] $ echo 500000 >/proc/sys/net/ipv4/tcp_notsent_lowat $ cat bench_rr.sh SUM=0 for i in {1..10} do V=`netperf -H remote_host -l30 -t TCP_RR -- -r 10000000,10000 -o LOCAL_BYTES_SENT | egrep -v "MIGRATED|Bytes"` echo $V SUM=$(($SUM + $V)) done echo SUM=$SUM Before patch: $ bench_rr.sh 130000000 80000000 140000000 140000000 140000000 140000000 130000000 40000000 90000000 110000000 SUM=1140000000 After patch: $ bench_rr.sh 430000000 590000000 530000000 450000000 450000000 350000000 450000000 490000000 480000000 460000000 SUM=4680000000 # This is 410 % of the value before patch. Fixes: c9bee3b7fdec ("tcp: TCP_NOTSENT_LOWAT socket option") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Doug Porter <dsp@fb.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: fix signed/unsigned comparisonEric Dumazet2022-04-181-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernel test robot reported: smatch warnings: net/ipv4/tcp_input.c:5966 tcp_rcv_established() warn: unsigned 'reason' is never less than zero. I actually had one packetdrill failing because of this bug, and was about to send the fix :) v2: Andreas Schwab also pointed out that @reason needs to be negated before we reach tcp_drop_reason() Fixes: 4b506af9c5b8 ("tcp: add two drop reasons for tcp_ack()") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: add drop reason support to tcp_ofo_queue()Eric Dumazet2022-04-171-7/+2
| | | | | | | | | | | | | | | | | | packets in OFO queue might be redundant, and dropped. tcp_drop() is no longer needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: add drop reasons to tcp_rcv_synsent_state_process()Eric Dumazet2022-04-171-6/+9
| | | | | | | | | | | | | | Re-use existing reasons. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: make tcp_rcv_synsent_state_process() drop monitor friendEric Dumazet2022-04-171-9/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | 1) A valid RST packet should be consumed, to not confuse drop monitor. 2) Same remark for packet validating cross syn setup, even if we might ignore part of it. 3) When third packet of 3WHS is delayed, do not pretend the SYNACK was dropped. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: add drop reason support to tcp_prune_ofo_queue()Eric Dumazet2022-04-171-1/+2
| | | | | | | | | | | | | | | | Add one reason for packets dropped from OFO queue because of memory pressure. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: add two drop reasons for tcp_ack()Eric Dumazet2022-04-171-3/+4
| | | | | | | | | | | | | | | | | | Add TCP_TOO_OLD_ACK and TCP_ACK_UNSENT_DATA drop reasons so that tcp_rcv_established() can report them. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: add drop reasons to tcp_rcv_state_process()Eric Dumazet2022-04-171-7/+17
| | | | | | | | | | | | | | Add basic support for drop reasons in tcp_rcv_state_process() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: make tcp_rcv_state_process() drop monitor friendlyEric Dumazet2022-04-171-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | tcp_rcv_state_process() incorrectly drops packets instead of consuming it, making drop monitor very noisy, if not unusable. Calling tcp_time_wait() or tcp_done() is part of standard behavior, packets triggering these actions were not dropped. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: add drop reason support to tcp_validate_incoming()Eric Dumazet2022-04-171-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | Creates four new drop reasons for the following cases: 1) packet being rejected by RFC 7323 PAWS check 2) packet being rejected by SEQUENCE check 3) Invalid RST packet 4) Invalid SYN packet Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: get rid of rst_seq_matchEric Dumazet2022-04-171-8/+5
| | | | | | | | | | | | | | | | Small cleanup in tcp_validate_incoming(), no need for rst_seq_match setting and testing. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: consume incoming skb leading to a resetEric Dumazet2022-04-171-12/+16
| | | | | | | | | | | | | | | | | | | | | | Whenever tcp_validate_incoming() handles a valid RST packet, we should not pretend the packet was dropped. Create a special section at the end of tcp_validate_incoming() to handle this case. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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