Commit 1fd03622 authored Sep 15, 2025 by Kuniyuki Iwashima Committed by Jakub Kicinski Sep 17, 2025

selftest: packetdrill: Add tcp_fastopen_server_reset-after-disconnect.pkt.



The test reproduces the scenario explained in the previous patch.

Without the patch, the test triggers the warning and cannot see the last
retransmitted packet.

  # ./ksft_runner.sh tcp_fastopen_server_reset-after-disconnect.pkt
  TAP version 13
  1..2
  [   29.229250] ------------[ cut here ]------------
  [   29.231414] WARNING: CPU: 26 PID: 0 at net/ipv4/tcp_timer.c:542 tcp_retransmit_timer+0x32/0x9f0
  ...
  tcp_fastopen_server_reset-after-disconnect.pkt:26: error handling packet: Timed out waiting for packet
  not ok 1 ipv4
  tcp_fastopen_server_reset-after-disconnect.pkt:26: error handling packet: Timed out waiting for packet
  not ok 2 ipv6
  # Totals: pass:0 fail:2 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250915175800.118793-3-kuniyu@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 45c8a6cc

tools/testing/selftests/net/packetdrill/tcp_fastopen_server_reset-after-disconnect.pkt

0 → 100644

+26 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		`./defaults.sh
		./set_sysctls.py /proc/sys/net/ipv4/tcp_fastopen=0x602 /proc/sys/net/ipv4/tcp_timestamps=0`

		0 socket(..., SOCK_STREAM\|SOCK_NONBLOCK, IPPROTO_TCP) = 3
		+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
		+0 bind(3, ..., ...) = 0
		+0 listen(3, 1) = 0

		+0 < S 0:10(10) win 32792 <mss 1460,nop,nop,sackOK>
		+0 > S. 0:0(0) ack 11 win 65535 <mss 1460,nop,nop,sackOK>

		// sk->sk_state is TCP_SYN_RECV
		+.1 accept(3, ..., ...) = 4

		// tcp_disconnect() sets sk->sk_state to TCP_CLOSE
		+0 connect(4, AF_UNSPEC, ...) = 0
		+0 > R. 1:1(0) ack 11 win 65535

		// connect() sets sk->sk_state to TCP_SYN_SENT
		+0 fcntl(4, F_SETFL, O_RDWR\|O_NONBLOCK) = 0
		+0 connect(4, ..., ...) = -1 EINPROGRESS (Operation is now in progress)
		+0 > S 0:0(0) win 65535 <mss 1460,nop,nop,sackOK,nop,wscale 8>

		// tp->fastopen_rsk must be NULL
		+1 > S 0:0(0) win 65535 <mss 1460,nop,nop,sackOK,nop,wscale 8>