1// SPDX-License-Identifier: GPL-2.0
2// Test PRR-slowstart implementation.
3// In this variant we verify that the sender uses SACK info on an ACK
4// below snd_una.
5
6// Set up config.
7`./defaults.sh`
8
9// Establish a connection.
10    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
11   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
12   +0 bind(3, ..., ...) = 0
13   +0 listen(3, 1) = 0
14
15   +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 8>
16   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
17// RTT 10ms
18 +.01 < . 1:1(0) ack 1 win 320
19   +0 accept(3, ..., ...) = 4
20
21// Send 10 data segments.
22   +0 write(4, ..., 10000) = 10000
23   +0 > P. 1:10001(10000) ack 1
24
25// Lost packet 1:1001,4001:5001,7001:8001.
26 +.01 < . 1:1(0) ack 1 win 320 <sack 1001:2001,nop,nop>
27   +0 < . 1:1(0) ack 1 win 320 <sack 1001:3001,nop,nop>
28   +0 < . 1:1(0) ack 1 win 320 <sack 1001:3001 8001:9001,nop,nop>
29   +0 > . 1:1001(1000) ack 1
30
31+.012 < . 1:1(0) ack 4001 win 320 <sack 8001:9001,nop,nop>
32   +0 > . 4001:7001(3000) ack 1
33
34   +0 write(4, ..., 10000) = 10000
35
36// The following ACK was reordered - delayed so that it arrives with
37// an ACK field below snd_una. Here we check that the newly-SACKed
38// 2MSS at 5001:7001 cause us to send out 2 more MSS.
39+.002 < . 1:1(0) ack 3001 win 320 <sack 5001:7001,nop,nop>
40   +0 > . 7001:8001(1000) ack 1
41   +0 > . 10001:11001(1000) ack 1
42