1// SPDX-License-Identifier: GPL-2.0 2// 3// Send a RST to a fully established socket with pending data before 4// it is accepted. 5// 6// The socket with pending data won't go away and can still be accepted 7// with data read. But it will be in TCP_CLOSE state. 8 9`./defaults.sh` 10 11 0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 3 12 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 13 +0 bind(3, ..., ...) = 0 14 +0 listen(3, 1) = 0 15 +0 setsockopt(3, SOL_TCP, TCP_FASTOPEN, [1], 4) = 0 16 17// Invalid cookie, so accept() fails. 18 +0 < S 0:10(10) win 32792 <mss 1460,sackOK,nop,nop,FO aaaaaaaaaaaaaaaa,nop,nop> 19 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK, FO TFO_COOKIE,nop,nop> 20 21 +0 accept(3, ..., ...) = -1 EAGAIN (Resource temporarily unavailable) 22 23// Complete 3WHS and send data and RST 24 +0 < . 1:1(0) ack 1 win 32792 25 +0 < . 1:11(10) ack 1 win 32792 26 +0 < R. 11:11(0) win 32792 27 28// A valid reset won't make the fully-established socket go away. 29// It's just that the acceptor will get a dead, unusable socket 30// in TCP_CLOSE state. 31 +0 accept(3, ..., ...) = 4 32 +0 %{ assert (tcpi_options & TCPI_OPT_SYN_DATA) == 0, tcpi_options }% 33 +0 %{ assert tcpi_state == TCP_CLOSE, tcpi_state }% 34 35 +0 write(4, ..., 100) = -1 ECONNRESET(Connection reset by peer) 36 +0 read(4, ..., 512) = 10 37 +0 read(4, ..., 512) = 0 38