diff options
Diffstat (limited to 'tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-4pkt.pkt')
| -rw-r--r-- | tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-4pkt.pkt | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-4pkt.pkt b/tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-4pkt.pkt new file mode 100644 index 000000000000..065fae9e9abd --- /dev/null +++ b/tools/testing/selftests/net/packetdrill/tcp_slow_start_slow-start-ack-per-4pkt.pkt @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 +// Test of slow start when not application-limited, so that +// the cwnd continues to grow. +// In this variant, the receiver sends one ACK per 4 packets. + +// Set up config. To keep things simple, disable the +// mechanism that defers sending in order to send bigger TSO packets. +`./defaults.sh +sysctl -q net.ipv4.tcp_tso_win_divisor=100` + + 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 257 + +0 accept(3, ..., ...) = 4 + +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 + + +0 write(4, ..., 30000) = 30000 + +0 > P. 1:10001(10000) ack 1 + +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% + + +.11 < . 1:1(0) ack 4001 win 257 + +0 > P. 10001:18001(8000) ack 1 + + +.01 < . 1:1(0) ack 8001 win 257 + +0 > P. 18001:26001(8000) ack 1 + ++.005 < . 1:1(0) ack 10001 win 257 + +0 > P. 26001:30001(4000) ack 1 + + +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }% |