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

--tolerance_usecs=500000

// Flush Hostcache
//0.0 `kldload cc_cubic`
0.0 `sysctl net.inet.tcp.cc.algorithm=cubic`
0.1 `sysctl net.inet.tcp.initcwnd_segments=10`
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 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
+0.005 bind(3, ..., ...) = 0
+0.005 listen(3, 1) = 0

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

+0.035 < SEW  0:0(0) win 65535 <mss 1000, sackOK, wscale 10, eol, nop, nop>
+0.000 > SE. 0:0(0) ack 1 win 65535 <...>
+0.000 <  . 1:1(0) ack 1 win 65535
+0.000 accept(3, ..., ...) = 4

// First, send IW plus 1 segment, drop 2nd packet to pull ssthresh low
0.700 write(4, ..., 11000) = 11000
+0 > .       1:1001(1000) ack 1
+0 %{ print "initial window:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) 
if (tcpi_snd_cwnd < 10000):
  print "Error - Initial Window smaller than 10 MSS!"
assert tcpi_snd_cwnd >= 10000
}%
+0 < . 1:1(0) ack 1001 win 64 
+0 > .    1001:2001(1000) ack 1
+0 < . 1:1(0) ack 2001 win 64
+0 > .    2001:3001(1000) ack 1
+0 < . 1:1(0) ack 3001 win 64
+0 > .    3001:4001(1000) ack 1
+0 < . 1:1(0) ack 4001 win 64
+0 > .    4001:5001(1000) ack 1
+0 < . 1:1(0) ack 5001 win 64
+0 > .    5001:6001(1000) ack 1  // we drop this packet, as cwnd > 15000.
                                 // this is needed for cubic to return a cwnd > 10000
                                 // in the initial rtt
+0 %{ print "at loss:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) 
if (tcpi_snd_cwnd < 15000):
  print "Error - CWnd not opened to 15000 at loss"
assert tcpi_snd_cwnd >= 15000
}%

+0 > .    6001:7001(1000) ack 1  
+0 < . 1:1(0) ack 5001 win 64 <sack 6001:7001, nop, nop>
+0 > .    7001:8001(1000) ack 1
+0 < . 1:1(0) ack 5001 win 64 <sack 6001:8001, nop, nop>
+0 > .    8001:9001(1000) ack 1
+0 < . 1:1(0) ack 5001 win 64 <sack 6001:9001, nop, nop>
+0 > .   9001:10001(1000) ack 1
+0 < . 1:1(0) ack 5001 win 64 <sack 6001:10001, nop, nop>
+0 > P. 10001:11001(1000) ack 1
+0 < . 1:1(0) ack 5001 win 64 <sack 6001:11001, nop, nop>

+0 > W.   5001:6001(1000) ack 1
+0 < . 1:1(0) ack 11001 win 64 
+0 %{ print "after iw with drop:\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%


// Next, we need to prime cubic; 
// Cubic needs 8 RTT samples before working
// without Timestamps, one rtt sample per window
//
// after pipe run empty above, cwnd should be 2 (rfc6582)
// or 1; one rtt sample should have been collected already during IW
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 11000) = 11000
+0.001 write(4, ..., 12000) = 12000

+0 > .    11001:12001(1000) ack 1
+0 < .    1:1(0) ack 12001 win 64
+0 > .    12001:13001(1000) ack 1
+0 < .    1:1(0) ack 13001 win 64
+0 > .    13001:14001(1000) ack 1
+0 > .    14001:15001(1000) ack 1
+0 < .    1:1(0) ack 15001 win 64
+0 > .    15001:16001(1000) ack 1
+0 > .    16001:17001(1000) ack 1
+0 > .    17001:18001(1000) ack 1
+0 < .    1:1(0) ack 18001 win 64
+0 > .    18001:19001(1000) ack 1
+0 > .    19001:20001(1000) ack 1
+0 > .    20001:21001(1000) ack 1
+0 < .    1:1(0) ack 21001 win 64
+0 > .    21001:22001(1000) ack 1
+0 > .    22001:23001(1000) ack 1
+0 > .    23001:24001(1000) ack 1
+0 > .    24001:25001(1000) ack 1
+0 < .    1:1(0) ack 25001 win 64
+0 > .    25001:26001(1000) ack 1
+0 > .    26001:27001(1000) ack 1
+0 > .    27001:28001(1000) ack 1
+0 > .    28001:29001(1000) ack 1
+0 < .    1:1(0) ack 29001 win 64
+0 > .    29001:30001(1000) ack 1
+0 > .    30001:31001(1000) ack 1
+0 > .    31001:32001(1000) ack 1
+0 > .    32001:33001(1000) ack 1
+0 > .    33001:34001(1000) ack 1
+0 < .    1:1(0) ack 34001 win 64
+0 > .    34001:35001(1000) ack 1
+0 > .    35001:36001(1000) ack 1
+0 > .    36001:37001(1000) ack 1
+0 > .    37001:38001(1000) ack 1
+0 > .    38001:39001(1000) ack 1
+0 < .    1:1(0) ack 39001 win 64
+0 > .    39001:40001(1000) ack 1
+0 > .    40001:41001(1000) ack 1
+0 > .    41001:42001(1000) ack 1
+0 > .    42001:43001(1000) ack 1
+0 > .    43001:44001(1000) ack 1
+0 < .    1:1(0) ack 44001 win 64
+0 > .    44001:45001(1000) ack 1
+0 > .    45001:46001(1000) ack 1
+0 > .    46001:47001(1000) ack 1
+0 > .    47001:48001(1000) ack 1
+0 > .    48001:49001(1000) ack 1
+0 < .    1:1(0) ack 49001 win 64
+0 > .    49001:50001(1000) ack 1
+0 > .    50001:51001(1000) ack 1
+0 > .    51001:52001(1000) ack 1
+0 > .    52001:53001(1000) ack 1
+0 > .    53001:54001(1000) ack 1
+0 < .    1:1(0) ack 54001 win 64
+0 > .    54001:55001(1000) ack 1
+0 > .    55001:56001(1000) ack 1
+0 > .    56001:57001(1000) ack 1
+0 > .    57001:58001(1000) ack 1
+0 > .    58001:59001(1000) ack 1
+0 < .    1:1(0) ack 59001 win 64
+0 > .    59001:60001(1000) ack 1
+0 > .    60001:61001(1000) ack 1
+0 > .    61001:62001(1000) ack 1
+0 > .    62001:63001(1000) ack 1
+0 > .    63001:64001(1000) ack 1
+0 < .    1:1(0) ack 64001 win 64
+0 > .    64001:65001(1000) ack 1
+0 > .    65001:66001(1000) ack 1
+0 > .    66001:67001(1000) ack 1
+0 > .    67001:68001(1000) ack 1
+0 > .    68001:69001(1000) ack 1
+0 < .    1:1(0) ack 69001 win 64
+0 > .    69001:70001(1000) ack 1
+0 > .    70001:71001(1000) ack 1
+0 > .    71001:72001(1000) ack 1
+0 > .    72001:73001(1000) ack 1
+0 > .    73001:74001(1000) ack 1
+0 < .    1:1(0) ack 74001 win 64
+0 > .    74001:75001(1000) ack 1
+0 > .    75001:76001(1000) ack 1
+0 > .    76001:77001(1000) ack 1
+0 > .    77001:78001(1000) ack 1
+0 > .    78001:79001(1000) ack 1
+0 < .    1:1(0) ack 79001 win 64
+0 > .    79001:80001(1000) ack 1
+0 > .    80001:81001(1000) ack 1
+0 > .    81001:82001(1000) ack 1
+0 > .    82001:83001(1000) ack 1
+0 > .    83001:84001(1000) ack 1
+0 < .    1:1(0) ack 84001 win 64
+0 > .    84001:85001(1000) ack 1
+0 > .    85001:86001(1000) ack 1
+0 > .    86001:87001(1000) ack 1
+0 > .    87001:88001(1000) ack 1
+0 > .    88001:89001(1000) ack 1
+0 < .    1:1(0) ack 89001 win 64
+0 > .    89001:90001(1000) ack 1
+0 > .    90001:91001(1000) ack 1
+0 > .    91001:92001(1000) ack 1
+0 > .    92001:93001(1000) ack 1
+0 > .    93001:94001(1000) ack 1
+0 < .    1:1(0) ack 94001 win 64
+0 > .    94001:95001(1000) ack 1
+0 > .    95001:96001(1000) ack 1
+0 > .    96001:97001(1000) ack 1
+0 > .    97001:98001(1000) ack 1
+0 > .    98001:99001(1000) ack 1
+0 < .    1:1(0) ack 99001 win 64
+0 > P.    99001:100001(1000) ack 1
+0 < .    1:1(0) ack 100001 win 64


+0 %{ print "after rtt samples:\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh)
if (tcpi_snd_cwnd < 10000):
  print "Error - congestion window not large enough for further testing"
assert tcpi_snd_cwnd >= 10000
}%



// Now, check if cwnd jumps to very high value after idle
+10 write(4, ..., 10000) = 10000

+0 > .    100001:101001(1000) ack 1
+0 %{ print "after-idle:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) 
if (tcpi_snd_cwnd != 10000):
  print "Error - Restart Window not equal to Initial Window (IW10)"
assert tcpi_snd_cwnd == 10000
}%
+0 < .    1:1(0) ack 101001 win 64
+0 > .    101001:102001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 102001 win 64
+0 > .    102001:103001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 103001 win 64
+0 > .    103001:104001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 104001 win 64
+0 > .    104001:105001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 105001 win 64
+0 > .    105001:106001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 106001 win 64
+0 > .    106001:107001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 107001 win 64
+0 > .    107001:108001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 108001 win 64
+0 > .    108001:109001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 109001 win 64
+0 > P.    109001:110001(1000) ack 1
+0 %{ print "cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh) }%
+0 < .    1:1(0) ack 110001 win 64


+0 %{ print "second window:\t\t cwnd: {}  ssthresh: {}".format(tcpi_snd_cwnd, tcpi_snd_ssthresh)
if ((tcpi_snd_cwnd < 10000) or (tcpi_snd_cwnd >11020)):
  print "Error - expected cwnd is\n\t10000 (IW10),\n\t10626 (cubic, 0 ticks diff) or\n\t11020 (cubic, 1 ticks diff)."
  print "\t\tcwnd: {}".format(tcpi_snd_cwnd)
assert ((tcpi_snd_cwnd >= 10000) and (tcpi_snd_cwnd <=11020))
}%


+0.2 close(4) = 0
+0.01 < F. 1:1(0) ack 110002 win 65535