1// SPDX-License-Identifier: GPL-2.0 2// Verify behavior for the sequence: remote side sends FIN, then we close(). 3// Since the remote side (client) closes first, we test our LAST_ACK code path. 4 5`./defaults.sh` 6 7// Initialize a server socket. 8 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 9 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 10 +0 bind(3, ..., ...) = 0 11 +0 listen(3, 1) = 0 12 13 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> 14 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> 15 +0 < . 1:1(0) ack 1 win 257 16 17 +0 accept(3, ..., ...) = 4 18 19// Client closes first. 20 +.01 < F. 1:1(0) ack 1 win 257 21 +0 > . 1:1(0) ack 2 22 23// App notices that client closed. 24 +0 read(4, ..., 1000) = 0 25 26// Then we close. 27 +.01 close(4) = 0 28 +0 > F. 1:1(0) ack 2 29 30// Client ACKs our FIN. 31 +.01 < . 2:2(0) ack 2 win 257 32 33// Verify that we send RST in response to any incoming segments 34// (because the kernel no longer has any record of this socket). 35 +.01 < . 2:2(0) ack 2 win 257 36 +0 > R 2:2(0) 37