54 lines
1.7 KiB
Plaintext
54 lines
1.7 KiB
Plaintext
// 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 doesn't support 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,nop,wscale 7>
|
|
+0 > S. 0:0(0) ack 1 <mss 1460,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
|
|
+0 > . 10001:11001(1000) ack 1
|
|
|
|
// Limited transmit: on second dupack, send a new data segment.
|
|
+.01 < . 1:1(0) ack 1 win 320
|
|
+0 > . 11001:12001(1000) ack 1
|
|
|
|
// It turned out to be reordering, not loss.
|
|
// We have one packet newly acked (1001:3001 were DUP-ACK'd)
|
|
// So we revert state back to Open. Slow start cwnd from 10 to 11
|
|
// and send 11 - 9 = 2 packets
|
|
+.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
|