// A simple server-side test that sends exactly an initial window (IW10)
// worth of packets.

--tolerance_usecs=500000

// Flush Hostcache
0.0 `sysctl net.inet.tcp.cc.algorithm=newreno`
0.05 `sysctl net.inet.tcp.ecn.enable=1`
0.1 `sysctl net.inet.tcp.initcwnd_segments=10`
0.15 `sysctl net.inet.tcp.rfc3465=1`
0.2 `sysctl net.inet.tcp.hostcache.purgenow=1`
0.3 `sync` // in case of crash

// Create a listening TCP socket.
 0.50 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0.005 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+0.005 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0.005 setsockopt(3, SOL_SOCKET, SO_DEBUG, [1], 4) = 0
+0.005 setsockopt(3, SOL_SOCKET, SO_SNDBUF, [1048576], 4) = 0

// Establish a TCP connection with ECN to explicitly track CWR

+0.035 connect(3, ..., ...) = -1 // EINPROGRESS

+0 > SEW 0:0(0) win 65535 <mss 1460, nop,wscale 6,sackOK,TS val ... ecr 0>

// Respond with invalid TCP ECN header flags, session should be Not-ECN

+0 < SEW. 0:0(0) ack 1 win 65535 <mss 1000, sackOK, wscale 10, eol, nop, nop>

+0 %{ print "window at syn:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh)
if (tcpi_state != TCPI_ESTABLISHED):
  print "Error - not in ESTABLISHED state"
assert tcpi_state == TCPI_ESTABLISHED
}%

+0 > .   1:1(0) ack 1 win 1031

+0.01 getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
+0.01 fcntl(3, F_SETFL, O_RDWR) = 0   // set back to blocking


// First, send IW plus 1 segment, drop 2nd packet to pull ssthresh low
0.700 write(3, ..., 15000) = 15000

+0 > .       1:1001(1000) ack 1
+0 > .    1001:2001(1000) ack 1
+0 > .    2001:3001(1000) ack 1
+0 > .    3001:4001(1000) ack 1
+0 > .    4001:5001(1000) ack 1
+0 > .    5001:6001(1000) ack 1
+0 > .    6001:7001(1000) ack 1
+0 > .    7001:8001(1000) ack 1
+0 > .    8001:9001(1000) ack 1
+0 > .   9001:10001(1000) ack 1
+0 %{ print "window at syn:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%

+0.1 < E. 1:1(0) ack 1001 win 64
+0 %{ print "window at syn:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 > .   10001:11001(1000) ack 1
+0.1 < .  1:1(0) ack 2001 win 64
+0.1 < .  1:1(0) ack 3001 win 64
+0.1 < .  1:1(0) ack 4001 win 64
+0.1 < .  1:1(0) ack 5001 win 64
+0.1 < .  1:1(0) ack 6001 win 64
+0.1 < .  1:1(0) ack 7001 win 64
+0.1 < .  1:1(0) ack 8001 win 64
+0.1 < .  1:1(0) ack 9001 win 64
+0.1 < .  1:1(0) ack 10001 win 64
+0.1 < .  1:1(0) ack 11001 win 64
+0.1 < .  1:1(0) ack 12001 win 64
+0.1 < .  1:1(0) ack 13001 win 64
+0.1 < .  1:1(0) ack 14001 win 64
+0.1 < .  1:1(0) ack 15001 win 64


+0 %{ print "window at syn:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%


+0.1 close(3) = 0
+0.1 < F. 1:1(0) ack 15002 win 65535