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| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-09-28 00:29:46 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-09-30 04:41:39 +0300 |
| commit | a8b1750e68f5fd6fe4bdff6f5d59d157c87a9b99 (patch) | |
| tree | 76b738a37dc72fbcb1addbddaf687a0ab7c44095 | |
| parent | 5ed080f85a33ad76288711c64ec2d8699de65ff9 (diff) | |
| download | linux-a8b1750e68f5fd6fe4bdff6f5d59d157c87a9b99.tar.xz | |
selftest: packetdrill: Import opt34/icmp-before-accept.pkt.
This imports the non-experimental version of icmp-before-accept.pkt.
This file tests the scenario where an ICMP unreachable packet for a
not-yet-accept()ed socket changes its state to TCP_CLOSE, but the
SYN data must be read without error, and the following read() returns
EHOSTUNREACH.
Note that this test support only IPv4 as icmp is used.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250927213022.1850048-9-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | tools/testing/selftests/net/packetdrill/tcp_fastopen_server_icmp-before-accept.pkt | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/packetdrill/tcp_fastopen_server_icmp-before-accept.pkt b/tools/testing/selftests/net/packetdrill/tcp_fastopen_server_icmp-before-accept.pkt new file mode 100644 index 000000000000..d5543672e2bd --- /dev/null +++ b/tools/testing/selftests/net/packetdrill/tcp_fastopen_server_icmp-before-accept.pkt @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Send an ICMP host_unreachable pkt to a pending SYN_RECV req. +// +// If it's a TFO req, the ICMP error will cause it to switch +// to TCP_CLOSE state but remains in the acceptor queue. + +--ip_version=ipv4 + +`./defaults.sh` + + 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 setsockopt(3, SOL_TCP, TCP_FASTOPEN, [1], 4) = 0 + + +0 < S 0:10(10) win 32792 <mss 1460,sackOK,nop,nop,FO TFO_COOKIE,nop,nop> + +0 > S. 0:0(0) ack 11 <mss 1460,nop,nop,sackOK> + +// Out-of-window icmp is ignored but accounted. + +0 `nstat > /dev/null` + +0 < icmp unreachable [5000:6000(1000)] + +0 `nstat | grep TcpExtOutOfWindowIcmps > /dev/null` + +// Valid ICMP unreach. + +0 < icmp unreachable host_unreachable [0:10(10)] + +// Unlike the non-TFO case, the req is still there to be accepted. + +0 accept(3, ..., ...) = 4 + +0 %{ assert (tcpi_options & TCPI_OPT_SYN_DATA) != 0, tcpi_options }% + +// tcp_done_with_error() in tcp_v4_err() sets sk->sk_state +// to TCP_CLOSE + +0 %{ assert tcpi_state == TCP_CLOSE, tcpi_state }% + +// The 1st read will succeed and return the data in SYN + +0 read(4, ..., 512) = 10 + +// The 2nd read will fail. + +0 read(4, ..., 512) = -1 EHOSTUNREACH (No route to host) + +// But is no longer writable because it's in TCP_CLOSE state. + +0 write(4, ..., 100) = -1 EPIPE (Broken Pipe) + +// inbound pkt will trigger RST because the socket has been moved +// off the TCP hash tables. + +0 < . 1:1(0) ack 1 win 32792 + +0 > R 1:1(0) |