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| author | Jakub Kicinski <kuba@kernel.org> | 2026-02-26 06:07:07 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-02-26 06:07:07 +0300 |
| commit | 7c9db1a1cd3be140f7807aa9f405cc17be59dc2a (patch) | |
| tree | cd8a998015198a0a4172a6ba8a7b1f7ca3062ff3 /tools | |
| parent | 5cc619583c7e735c4fb801bede671fb6f9c79425 (diff) | |
| parent | 74511332309844c3de64970841b3c250d85f34ce (diff) | |
| download | linux-7c9db1a1cd3be140f7807aa9f405cc17be59dc2a.tar.xz | |
Merge branch 'tcp-re-enable-acceptance-of-fin-packets-when-rwin-is-0'
Simon Baatz says:
====================
tcp: re-enable acceptance of FIN packets when RWIN is 0
this series restores the ability to accept in‑sequence FIN packets
even when the advertised receive window is zero, and adds a
packetdrill test to guard the behavior.
====================
Link: https://patch.msgid.link/20260224-fix_zero_wnd_fin-v2-0-a16677ea7cea@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/net/packetdrill/tcp_rcv_zero_wnd_fin.pkt | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/packetdrill/tcp_rcv_zero_wnd_fin.pkt b/tools/testing/selftests/net/packetdrill/tcp_rcv_zero_wnd_fin.pkt new file mode 100644 index 000000000000..e245359a1a91 --- /dev/null +++ b/tools/testing/selftests/net/packetdrill/tcp_rcv_zero_wnd_fin.pkt @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 + +// Some TCP stacks send FINs even though the window is closed. We break +// a possible FIN/ACK loop by accepting the FIN. + +--mss=1000 + +`./defaults.sh` + +// Establish a connection. + +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 + +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 + +0 setsockopt(3, SOL_SOCKET, SO_RCVBUF, [20000], 4) = 0 + +0 bind(3, ..., ...) = 0 + +0 listen(3, 1) = 0 + + +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7> + +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 0> + +0 < . 1:1(0) ack 1 win 257 + + +0 accept(3, ..., ...) = 4 + + +0 < P. 1:60001(60000) ack 1 win 257 + * > . 1:1(0) ack 60001 win 0 + + +0 < F. 60001:60001(0) ack 1 win 257 + +0 > . 1:1(0) ack 60002 win 0 |