| // 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 |
