diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2025-06-27 15:35:08 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-06-27 15:35:09 -0700 |
| commit | 2f5a4117599caa29ea594585a82cef21d7812302 (patch) | |
| tree | 966d82b8403bcfab4ed758ef454cb60fac48f63e | |
| parent | 680367bc9be929235cb9d972c8614c1fe16fa67a (diff) | |
| parent | 8cc8d749dc7eac9ee8355aa91042aac6c7afa639 (diff) | |
Merge branch 'tcp-fix-dsack-bug-with-non-contiguous-ranges'
Eric Dumazet says:
====================
tcp: fix DSACK bug with non contiguous ranges
This series combines a fix from xin.guo and a new packetdrill test.
====================
Link: https://patch.msgid.link/20250626123420.1933835-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/tcp_input.c | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/net/packetdrill/tcp_dsack_mult.pkt | 45 |
2 files changed, 47 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 19a1542883df..79e3bfb0108f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4845,8 +4845,9 @@ static void tcp_ofo_queue(struct sock *sk) if (before(TCP_SKB_CB(skb)->seq, dsack_high)) { __u32 dsack = dsack_high; + if (before(TCP_SKB_CB(skb)->end_seq, dsack_high)) - dsack_high = TCP_SKB_CB(skb)->end_seq; + dsack = TCP_SKB_CB(skb)->end_seq; tcp_dsack_extend(sk, TCP_SKB_CB(skb)->seq, dsack); } p = rb_next(p); diff --git a/tools/testing/selftests/net/packetdrill/tcp_dsack_mult.pkt b/tools/testing/selftests/net/packetdrill/tcp_dsack_mult.pkt new file mode 100644 index 000000000000..c790d0af635e --- /dev/null +++ b/tools/testing/selftests/net/packetdrill/tcp_dsack_mult.pkt @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +// Test various DSACK (RFC 2883) behaviors. + +--mss=1000 + +`./defaults.sh` + + + 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 + + +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 8> + +.1 < . 1:1(0) ack 1 win 1024 + +0 accept(3, ..., ...) = 4 + +// First SACK range. + +0 < P. 1001:2001(1000) ack 1 win 1024 + +0 > . 1:1(0) ack 1 <nop, nop, sack 1001:2001> + +// Check SACK coalescing (contiguous sequence). + +0 < P. 2001:3001(1000) ack 1 win 1024 + +0 > . 1:1(0) ack 1 <nop,nop,sack 1001:3001> + +// Check we have two SACK ranges for non contiguous sequences. + +0 < P. 4001:5001(1000) ack 1 win 1024 + +0 > . 1:1(0) ack 1 <nop,nop,sack 4001:5001 1001:3001> + +// Three ranges. + +0 < P. 7001:8001(1000) ack 1 win 1024 + +0 > . 1:1(0) ack 1 <nop,nop,sack 7001:8001 4001:5001 1001:3001> + +// DSACK (1001:3001) + SACK (6001:7001) + +0 < P. 1:6001(6000) ack 1 win 1024 + +0 > . 1:1(0) ack 6001 <nop,nop,sack 1001:3001 7001:8001> + +// DSACK (7001:8001) + +0 < P. 6001:8001(2000) ack 1 win 1024 + +0 > . 1:1(0) ack 8001 <nop,nop,sack 7001:8001> + +// DSACK for an older segment. + +0 < P. 1:1001(1000) ack 1 win 1024 + +0 > . 1:1(0) ack 8001 <nop,nop,sack 1:1001> |