// Limited transmit KASSERT "sent too much" from tcp_maxseg() overestimating
// SACK option space: no timestamps, five SACK blocks pending, one full
// segment sent after an RTO. Panics an INVARIANTS kernel without the fix.

--ip_version=ipv4

 0.000 `sysctl -w net.inet.tcp.hostcache.purgenow=1`
+0.000 `sysctl -w net.inet.tcp.syncookies_only=0`
+0.000 `sysctl -w net.inet.tcp.syncookies=1`
+0.000 `sysctl -w net.inet.tcp.sack.enable=1`
+0.000 `sysctl -w net.inet.tcp.functions_default=freebsd`
+0.000 `sysctl -w net.inet.tcp.cc.algorithm=cubic`
+0.000 `sysctl -w kern.timecounter.alloweddeviation=0`
+0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0.000 bind(3, ..., ...) = 0
+0.000 listen(3, 1) = 0
// No timestamps, no window scaling; t_maxseg = 1000.
+0.000 < S     0:0(0)                win 65535 <mss 1000,sackOK,eol,eol>
+0.000 > S.    0:0(0)       ack    1 win 65535 <...>
+0.050 <  .    1:1(0)       ack    1 win 65535
+0.000 accept(3, ..., ...) = 4
+0.000 close(3) = 0
// Five out-of-order blocks: rcv_numsacks = 5, only 4 fit on the wire.
+0.000 <  .  101:201(100)   ack    1 win 65535
+0.000 >  .    1:1(0)       ack    1 <...>
+0.000 <  .  301:401(100)   ack    1 win 65535
+0.000 >  .    1:1(0)       ack    1 <...>
+0.000 <  .  501:601(100)   ack    1 win 65535
+0.000 >  .    1:1(0)       ack    1 <...>
+0.000 <  .  701:801(100)   ack    1 win 65535
+0.000 >  .    1:1(0)       ack    1 <...>
+0.000 <  .  901:1001(100)  ack    1 win 65535
+0.000 >  .    1:1(0)       ack    1 <...>
// One small segment, lost; the RTO leaves cwnd = 1000, t_rxtshift = 1.
+0.000 send(4, ..., 300, 0) = 300
+0.000 > P.    1:301(300)   ack    1 <...>
+1.000~+1.200 > P.    1:301(300)   ack    1 <...>
// 700 bytes of cwnd left, below a full segment, so Nagle holds the rest.
+0.010 send(4, ..., 5000, 0) = 5000
// First dup ACK: limited transmit sends one full 964-byte segment
// (1000 - 36 bytes of options), while tcp_maxseg() said 960.
+0.010 <  .    1:1(0)       ack    1 win 65535 <nop,nop,sack 101:301>
+0.000 >  .  301:1265(964)  ack    1 <...>