1*5d4cadefSSoham Chakradeo// SPDX-License-Identifier: GPL-2.0 2*5d4cadefSSoham Chakradeo 3*5d4cadefSSoham Chakradeo`./defaults.sh` 4*5d4cadefSSoham Chakradeo 5*5d4cadefSSoham Chakradeo 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 6*5d4cadefSSoham Chakradeo +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 7*5d4cadefSSoham Chakradeo +0 bind(3, ..., ...) = 0 8*5d4cadefSSoham Chakradeo +0 listen(3, 1) = 0 9*5d4cadefSSoham Chakradeo 10*5d4cadefSSoham Chakradeo 11*5d4cadefSSoham Chakradeo +0 < S 0:0(0) win 0 <mss 1460> 12*5d4cadefSSoham Chakradeo +0 > S. 0:0(0) ack 1 <mss 1460> 13*5d4cadefSSoham Chakradeo 14*5d4cadefSSoham Chakradeo +.1 < . 1:1(0) ack 1 win 65530 15*5d4cadefSSoham Chakradeo +0 accept(3, ..., ...) = 4 16*5d4cadefSSoham Chakradeo 17*5d4cadefSSoham Chakradeo +0 setsockopt(4, SOL_TCP, TCP_USER_TIMEOUT, [3000], 4) = 0 18*5d4cadefSSoham Chakradeo +0 write(4, ..., 24) = 24 19*5d4cadefSSoham Chakradeo +0 > P. 1:25(24) ack 1 20*5d4cadefSSoham Chakradeo +.1 < . 1:1(0) ack 25 win 65530 21*5d4cadefSSoham Chakradeo +0 %{ assert tcpi_probes == 0, tcpi_probes; \ 22*5d4cadefSSoham Chakradeo assert tcpi_backoff == 0, tcpi_backoff }% 23*5d4cadefSSoham Chakradeo 24*5d4cadefSSoham Chakradeo// install a qdisc dropping all packets 25*5d4cadefSSoham Chakradeo +0 `tc qdisc delete dev tun0 root 2>/dev/null ; tc qdisc add dev tun0 root pfifo limit 0` 26*5d4cadefSSoham Chakradeo +0 write(4, ..., 24) = 24 27*5d4cadefSSoham Chakradeo // When qdisc is congested we retry every 500ms 28*5d4cadefSSoham Chakradeo // (TCP_RESOURCE_PROBE_INTERVAL) and therefore 29*5d4cadefSSoham Chakradeo // we retry 6 times before hitting 3s timeout. 30*5d4cadefSSoham Chakradeo // First verify that the connection is alive: 31*5d4cadefSSoham Chakradeo+3.250 write(4, ..., 24) = 24 32*5d4cadefSSoham Chakradeo // Now verify that shortly after that the socket is dead: 33*5d4cadefSSoham Chakradeo +.100 write(4, ..., 24) = -1 ETIMEDOUT (Connection timed out) 34*5d4cadefSSoham Chakradeo 35*5d4cadefSSoham Chakradeo +0 %{ assert tcpi_probes == 6, tcpi_probes; \ 36*5d4cadefSSoham Chakradeo assert tcpi_backoff == 0, tcpi_backoff }% 37*5d4cadefSSoham Chakradeo +0 close(4) = 0 38