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// SPDX-License-Identifier: GPL-2.0
//
// RFC 9293 Section 3.10.7.4: in SYN-RECEIVED, an exact RST resets
// the connection. A non-exact in-window RST elicits a challenge ACK,
// while an out-of-window RST is silently discarded.
`./defaults.sh`
// An exact RST removes the request socket.
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 0:0(0) win 1000 <mss 1000,sackOK,nop,nop,nop,wscale 0>
+0 > S. 0:0(0) ack 1 <...>
+0 < R 1:1(0) win 1000
+.1 < . 1:1(0) ack 1 win 1000
+0 > R 1:1(0)
+0 close(3) = 0
// A non-exact in-window RST gets a challenge ACK and the request survives.
+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 0:0(0) win 1000 <mss 1000,sackOK,nop,nop,nop,wscale 0>
+0 > S. 0:0(0) ack 1 <...>
+0 < R 2:2(0) win 1000
+0 > . 1:1(0) ack 1
+0 < . 1:1(0) ack 1 win 1000
+0 accept(3, ..., ...) = 4
+0 close(4) = 0
+0 close(3) = 0
// RST sequence validation precedes ACK validation. Even an RST|ACK
// with an unacceptable ACK value gets a challenge ACK.
+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 0:0(0) win 1000 <mss 1000,sackOK,nop,nop,nop,wscale 0>
+0 > S. 0:0(0) ack 1 <...>
+0 < R. 2:2(0) ack 100 win 1000
+0 > . 1:1(0) ack 1
+0 < . 1:1(0) ack 1 win 1000
+0 accept(3, ..., ...) = 4
+0 close(4) = 0
+0 close(3) = 0
// An out-of-window RST is silent and does not remove the request.
+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 0:0(0) win 1000 <mss 1000,sackOK,nop,nop,nop,wscale 0>
+0 > S. 0:0(0) ack 1 <...>
+0 < R 100001:100001(0) win 1000
+.1 < . 1:1(0) ack 1 win 1000
+0 accept(3, ..., ...) = 4
+0 close(4) = 0
+0 close(3) = 0
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