mirror of https://github.com/torvalds/linux.git
41 lines
1.3 KiB
Plaintext
41 lines
1.3 KiB
Plaintext
// SPDX-License-Identifier: GPL-2.0
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// This is a test inspired by an Android client app using SSL. This
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// test verifies using TCP_NODELAY would save application latency
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// (Perhaps even better with TCP_NAGLE).
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//
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`./defaults.sh
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ethtool -K tun0 tso off gso off
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./set_sysctls.py /proc/sys/net/ipv4/tcp_timestamps=0`
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0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4
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+0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
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+0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0
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+0 connect(4, ..., ...) = -1 EINPROGRESS (Operation now in progress)
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+0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8>
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+.1 < S. 0:0(0) ack 1 win 5792 <mss 974,nop,nop,sackOK,nop,wscale 7>
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+0 > . 1:1(0) ack 1
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// SSL handshake (resumed session)
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+0 write(4, ..., 517) = 517
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+0 > P. 1:518(517) ack 1
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+.1 < . 1:1(0) ack 518 win 229
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+0 < P. 1:144(143) ack 1 win 229
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+0 > . 518:518(0) ack 144
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+0 read(4, ..., 1000) = 143
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// Application POST header (51B) and body (2002B)
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+0 write(4, ..., 51) = 51
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+0 > P. 518:569(51) ack 144
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+.03 write(4, ..., 2002) = 2002
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+0 > . 569:1543(974) ack 144
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+0 > P. 1543:2517(974) ack 144
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// Without disabling Nagle, this packet will not happen until the remote ACK.
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+0 > P. 2517:2571(54) ack 144
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+.1 < . 1:1(0) ack 2571 win 229
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// Reset sysctls
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`/tmp/sysctl_restore_${PPID}.sh`
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