| // SPDX-License-Identifier: GPL-2.0 |
| // Test RFC 3042 "Limited Transmit": "sending a new data segment in |
| // response to each of the first two duplicate acknowledgments that |
| // arrive at the sender". |
| // This variation tests a receiver that supports SACK. |
| |
| `./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> |
| +.1 < . 1:1(0) ack 1 win 320 |
| +0 accept(3, ..., ...) = 4 |
| |
| // Write some data, and send the initial congestion window. |
| +0 write(4, ..., 15000) = 15000 |
| +0 > P. 1:10001(10000) ack 1 |
| |
| // Limited transmit: on first dupack, send a new data segment. |
| +.11 < . 1:1(0) ack 1 win 320 <sack 1001:2001,nop,nop> |
| +0 > . 10001:11001(1000) ack 1 |
| |
| // Limited transmit: on second dupack, send a new data segment. |
| +.01 < . 1:1(0) ack 1 win 320 <sack 1001:3001,nop,nop> |
| +0 > . 11001:12001(1000) ack 1 |
| |
| // It turned out to be reordering, not loss. |
| +.01 < . 1:1(0) ack 3001 win 320 |
| +0 > P. 12001:14001(2000) ack 1 |
| |
| +.02 < . 1:1(0) ack 5001 win 320 |
| +0 > P. 14001:15001(1000) ack 1 |
| |
| // Client gradually ACKs all data. |
| +.02 < . 1:1(0) ack 7001 win 320 |
| +.02 < . 1:1(0) ack 9001 win 320 |
| +.02 < . 1:1(0) ack 11001 win 320 |
| +.02 < . 1:1(0) ack 13001 win 320 |
| +.02 < . 1:1(0) ack 15001 win 320 |
| |
| // Clean up. |
| +.17 close(4) = 0 |
| +0 > F. 15001:15001(0) ack 1 |
| +.1 < F. 1:1(0) ack 15002 win 257 |
| +0 > . 15002:15002(0) ack 2 |
