xref: /linux/tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-app-limited.pkt (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1// SPDX-License-Identifier: GPL-2.0
2// Test of slow start when application-limited: in this case,
3// with IW10, if we send exactly 10 packets then cwnd should grow to 20.
4
5// Set up config.
6`./defaults.sh`
7
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  +.1 < 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  +.1 < . 1:1(0) ack 1 win 257
16   +0 accept(3, ..., ...) = 4
17   +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0
18
19   +0 write(4, ..., 10000) = 10000
20   +0 > P. 1:10001(10000) ack 1
21   +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }%
22
23+.105 < . 1:1(0) ack 2001 win 257
24   +0 %{ assert tcpi_snd_cwnd == 12, tcpi_snd_cwnd }%
25
26+.005 < . 1:1(0) ack 4001 win 257
27   +0 %{ assert tcpi_snd_cwnd == 14, tcpi_snd_cwnd }%
28
29+.005 < . 1:1(0) ack 6001 win 257
30   +0 %{ assert tcpi_snd_cwnd == 16, tcpi_snd_cwnd }%
31
32+.005 < . 1:1(0) ack 8001 win 257
33   +0 %{ assert tcpi_snd_cwnd == 18, tcpi_snd_cwnd }%
34
35+.005 < . 1:1(0) ack 10001 win 257
36   +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%
37