1// SPDX-License-Identifier: GPL-2.0
2// Test various DSACK (RFC 2883) behaviors.
3
4--mss=1000
5
6`./defaults.sh`
7
8
9    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
10   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
11   +0 bind(3, ..., ...) = 0
12   +0 listen(3, 1) = 0
13
14   +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
15   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
16  +.1 < . 1:1(0) ack 1 win 1024
17   +0 accept(3, ..., ...) = 4
18
19// First SACK range.
20   +0 < P. 1001:2001(1000) ack 1 win 1024
21   +0 > . 1:1(0) ack 1 <nop, nop, sack 1001:2001>
22
23// Check SACK coalescing (contiguous sequence).
24   +0 < P. 2001:3001(1000) ack 1 win 1024
25   +0 > . 1:1(0) ack 1 <nop,nop,sack 1001:3001>
26
27// Check we have two SACK ranges for non contiguous sequences.
28   +0 < P. 4001:5001(1000) ack 1 win 1024
29   +0 > . 1:1(0) ack 1 <nop,nop,sack 4001:5001 1001:3001>
30
31// Three ranges.
32   +0 < P. 7001:8001(1000) ack 1 win 1024
33   +0 > . 1:1(0) ack 1 <nop,nop,sack 7001:8001 4001:5001 1001:3001>
34
35// DSACK (1001:3001) + SACK (6001:7001)
36   +0 < P. 1:6001(6000) ack 1 win 1024
37   +0 > . 1:1(0) ack 6001 <nop,nop,sack 1001:3001 7001:8001>
38
39// DSACK (7001:8001)
40   +0 < P. 6001:8001(2000) ack 1 win 1024
41   +0 > . 1:1(0) ack 8001 <nop,nop,sack 7001:8001>
42
43// DSACK for an older segment.
44   +0 < P. 1:1001(1000) ack 1 win 1024
45   +0 > . 1:1(0) ack 8001 <nop,nop,sack 1:1001>
46