1// SPDX-License-Identifier: GPL-2.0 2// Verify that setsockopt calls that force a route refresh do not 3// cause problems matching SACKs with packets in the write queue. 4// This variant tests IP_TOS. 5 6`./defaults.sh` 7 8// Establish a connection. 9 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 10 +0 setsockopt(3, SOL_IP, IP_MTU_DISCOVER, [IP_PMTUDISC_DONT], 1) = 0 11 +0...0.010 connect(3, ..., ...) = 0 12 13 +0 > S 0:0(0) <mss 1460,sackOK,TS val 100 ecr 0,nop,wscale 8> 14 +.01 < S. 0:0(0) ack 1 win 65535 <mss 1460,nop,wscale 2,nop,nop,sackOK> 15 +0 > . 1:1(0) ack 1 16 17 +.01 write(3, ..., 5840) = 5840 18 +0 > P. 1:5841(5840) ack 1 19 +.01 < . 1:1(0) ack 5841 win 65535 20 21 +.01 write(3, ..., 5840) = 5840 22 +0 > P. 5841:11681(5840) ack 1 23 +.01 < . 1:1(0) ack 11681 win 65535 24 25 +.01 write(3, ..., 14600) = 14600 26 +0 > P. 11681:26281(14600) ack 1 27 28// Try the socket option that we know can force a route refresh. 29 +0 setsockopt(3, SOL_IP, IP_TOS, [4], 1) = 0 30// Then revert to avoid routing/mangling/etc implications of that setting. 31 +0 setsockopt(3, SOL_IP, IP_TOS, [0], 1) = 0 32 33// Verify that we do not retransmit the SACKed segments. 34 +.01 < . 1:1(0) ack 13141 win 65535 <sack 16061:17521 20441:26281,nop,nop> 35 +0 > . 13141:16061(2920) ack 1 36 +0 > P. 17521:20441(2920) ack 1 37 +.01 < . 1:1(0) ack 26281 win 65535 38