1// SPDX-License-Identifier: GPL-2.0 2// Verify that established connections drop a segment without the ACK flag set. 3 4`./defaults.sh` 5 6// Create a socket. 7 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 8 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 9 +0 bind(3, ..., ...) = 0 10 +0 listen(3, 1) = 0 11 12// Establish a connection. 13 +0 < S 0:0(0) win 20000 <mss 1000,sackOK,nop,nop> 14 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK> 15 +.01 < . 1:1(0) ack 1 win 20000 16 +0 accept(3, ..., ...) = 4 17 18// Receive a segment with no flags set, verify that it's not enqueued. 19 +.01 < - 1:1001(1000) win 20000 20 +0 ioctl(4, SIOCINQ, [0]) = 0 21 22// Receive a segment with ACK flag set, verify that it is enqueued. 23 +.01 < . 1:1001(1000) ack 1 win 20000 24 +0 ioctl(4, SIOCINQ, [1000]) = 0 25