// SPDX-License-Identifier: GPL-2.0 // Test send-buffer-limited time in tcp_info for client side. `./defaults.sh` // Create a socket and set it to non-blocking. 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) +0 > S 0:0(0) +.01 < S. 0:0(0) ack 1 win 10000 +0 > . 1:1(0) ack 1 +0 getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0 +0 fcntl(3, F_SETFL, O_RDWR) = 0 // set back to blocking +0 setsockopt(3, SOL_SOCKET, SO_SNDBUF, [10000], 4) = 0 +0 getsockopt(3, SOL_SOCKET, SO_SNDBUF, [20000], [4]) = 0 +.09...0.14 write(3, ..., 150000) = 150000 +.01 < . 1:1(0) ack 10001 win 10000 +.01 < . 1:1(0) ack 30001 win 10000 // cwnd goes from 40(60KB) to 80(120KB), and that we hit the tiny sndbuf limit 10KB +.01 < . 1:1(0) ack 70001 win 10000 +.02 < . 1:1(0) ack 95001 win 10000 +0 %{ assert 19000 <= tcpi_sndbuf_limited <= 21000, tcpi_sndbuf_limited; \ assert 49000 <= tcpi_busy_time <= 52000, tcpi_busy_time; \ assert 0 == tcpi_rwnd_limited, tcpi_rwnd_limited }% // This ack frees up enough buffer so we are no longer // buffer limited (socket flag SOCK_NOSPACE is cleared) +.02 < . 1:1(0) ack 150001 win 10000 +0 %{ assert 19000 <= tcpi_sndbuf_limited <= 21000, tcpi_sndbuf_limited;\ assert 69000 <= tcpi_busy_time <= 73000, tcpi_busy_time;\ assert 0 == tcpi_rwnd_limited, tcpi_rwnd_limited }%