1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
// SPDX-License-Identifier: GPL-2.0
// Test PRR-slowstart implementation.
// In this variant we test a simple case where in-flight == ssthresh
// all the way through recovery, so during fast recovery we send one segment
// for each segment SACKed/ACKed.
// Set up config.
`./defaults.sh`
// Establish a connection.
0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0
+.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
+0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
// RTT 100ms
+.1 < . 1:1(0) ack 1 win 320
+0 accept(3, ..., ...) = 4
// Send 10 data segments.
+0 write(4, ..., 10000) = 10000
+0 > P. 1:10001(10000) ack 1
// Lost packet 1:1001.
+.11 < . 1:1(0) ack 1 win 320 <sack 1001:2001,nop,nop>
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:3001,nop,nop>
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:4001,nop,nop>
// Enter fast recovery.
+0 > . 1:1001(1000) ack 1
+.01 %{
assert tcpi_ca_state == TCP_CA_Recovery, tcpi_ca_state
assert tcpi_snd_cwnd == 7, tcpi_snd_cwnd
assert tcpi_snd_ssthresh == 7, tcpi_snd_ssthresh
}%
// Write some more, which we will send 1 MSS at a time,
// as in-flight segments are SACKed or ACKed.
+.01 write(4, ..., 7000) = 7000
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:5001,nop,nop>
+0 > . 10001:11001(1000) ack 1
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:6001,nop,nop>
+0 > . 11001:12001(1000) ack 1
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:7001,nop,nop>
+0 > . 12001:13001(1000) ack 1
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:8001,nop,nop>
+0 > . 13001:14001(1000) ack 1
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:9001,nop,nop>
+0 > . 14001:15001(1000) ack 1
+.01 < . 1:1(0) ack 1 win 320 <sack 1001:10001,nop,nop>
+0 > . 15001:16001(1000) ack 1
+.02 < . 1:1(0) ack 10001 win 320
+0 > P. 16001:17001(1000) ack 1
// Leave fast recovery.
+.01 %{
assert tcpi_ca_state == TCP_CA_Open, tcpi_ca_state
assert tcpi_snd_cwnd == 7, tcpi_snd_cwnd
assert tcpi_snd_ssthresh == 7, tcpi_snd_ssthresh
}%
+.03 < . 1:1(0) ack 12001 win 320
+.02 < . 1:1(0) ack 14001 win 320
+.02 < . 1:1(0) ack 16001 win 320
+.02 < . 1:1(0) ack 17001 win 320
|
