snd-syn-rtx-drop-options-ipv4.pkt

//
// Copyright (c) 2016 Michael Tuexen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.
//

// Ensure that net.inet.tcp.rexmit_drop_options is honored.
// This means that TCP SYN segments get retransmitted and the third and further
// retransmissions of the SYN segment have no options.
// FIXME: There is still the MSS option.

--ip_version=ipv4
--tolerance_usecs=150000

// Ensure that all relevant sysctl variables have their default variables.
 0.00 `sysctl -w net.inet.tcp.rfc1323=1`
+0.00 `sysctl -w net.inet.tcp.sack.enable=1`
+0.00 `sysctl -w net.inet.tcp.ecn.enable=2`
+0.00 `sysctl -w net.inet.tcp.rexmit_initial=1000`
+0.00 `sysctl -w net.inet.tcp.rexmit_slop=200`
+0.00 `sysctl -w net.inet.tcp.rexmit_drop_options=0`
+0.00 `sysctl -w net.inet.tcp.keepinit=75000`
+0.00 `sysctl -w kern.ipc.maxsockbuf=2097152`
+0.00 `sysctl -w net.inet.tcp.recvspace=65536`
+0.00 `sysctl -w net.inet.tcp.sendspace=32768`
// Flush host cache.
+0.00 `sysctl -w net.inet.tcp.hostcache.purgenow=1`
// Ensure that the relevant sysctl variables have their value.
+0.00 `sysctl -w net.inet.tcp.rexmit_drop_options=1`
// Create a non-blocking TCP/IPv4 socket
+0.00 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0.00 fcntl(3, F_GETFL) = 0x02 (flags O_RDWR)
+0.00 fcntl(3, F_SETFL, O_RDWR | O_NONBLOCK) = 0
// Try to establish a TCP connection.
+0.00 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress)
+0.00 > S  0:0(0) win 65535 <mss 1460,nop,wscale 6,sackOK,TS val  100 ecr 0>
+1.00 > S  0:0(0) win 65535 <mss 1460,nop,wscale 6,sackOK,TS val 1100 ecr 0>
+2.20 > S  0:0(0) win 65535 <mss 1460,nop,wscale 6,sackOK,TS val 3300 ecr 0>
*     > S  0:0(0) win 65535 <mss 1460>
*     > S  0:0(0) win 65535 <mss 1460>
// Finally cleanup
+0.00 close(3) = 0
+0.00 `sysctl -w net.inet.tcp.rexmit_drop_options=0`