#!/usr/bin/perl
#
# SCTP Conformance Test Suite Implementation
# (C) Copyright Fujitsu Ltd. 2008, 2009
#
# This file is part of the SCTP Conformance Test Suite implementation.
#
# The SCTP Conformance Test Suite implementation is free software;
# you can redistribute it and/or modify it under the terms of
# the GNU General Public License version 2 as published by
# the Free Software Foundation.
#
# The SCTP Conformance Test Suite implementation is distributed in the
# hope that it will be useful, but WITHOUT ANY WARRANTY; without even
# the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
# PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU CC; see the file COPYING.  If not, write to
# the Free Software Foundation, 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
#
# Please send any bug reports or fixes you make to the
# email address(es):
#    networktest sctp <networktest-sctp@lists.sourceforge.net>
#
# Or submit a bug report through the following website:
#    http://networktest.sourceforge.net/
#
# Written or modified by:
#    Hiroaki Kago <linuxsctp-kg@ml.css.fujitsu.com>
#    Wei Yongjun <yjwei@cn.fujitsu.com>
#
# Any bugs reported given to us we will try to fix... any fixes shared will
# be incorporated into the next SCTP release.
#
##############################################################################
BEGIN {	$V6evalTool::TestVersion = '$Name: REL_1_0_0 $'; }

use lib "../common";
use V6evalTool;
use SCTP;

%pktdesc = (
	sctp_chunk_data_1	=> "Recv SCTP CHUNK_DATA (1)",
	sctp_chunk_data_2	=> "Recv SCTP CHUNK_DATA (2)",
	sctp_chunk_data_3	=> "Recv SCTP CHUNK_DATA (3)",
	sctp_chunk_data_4	=> "Recv SCTP CHUNK_DATA (4)",
	sctp_chunk_data_5	=> "Recv SCTP CHUNK_DATA (5)",
	sctp_chunk_data_6	=> "Recv SCTP CHUNK_DATA (6)",
	sctp_chunk_data_7	=> "Recv SCTP CHUNK_DATA (7)",
	sctp_chunk_sack_2	=> "Send SCTP CHUNK_SACK (1 and 2)",
	sctp_chunk_sack_3	=> "Send SCTP CHUNK_SACK (1 and 3)",
	sctp_chunk_sack_4	=> "Send SCTP CHUNK_SACK (1, 3 and 4)",
	sctp_chunk_sack_5	=> "Send SCTP CHUNK_SACK (1, 3 to 4)",
);

$IF0 = Link0;

vCapture($IF0);

sctpCheckEnv($IF0);

################## This code may be delete future ###################
vLogHTML('<B>== Modify MAX.BURST configure to let test easy ==</B>');
$MAX_BURST = sctpGetRemoteSys("MAX.BURST");
sctpSetRemoteSys("MAX.BURST", 10);

$SIZE = ($SCTP::CONF{ENABLE_IPV6} == 0) ? 1452 : 1432;
$COUNT = 4;
@cwnds = ();
sctpStatusClient($IF0, $COUNT, "-X 7 -x $COUNT -c $SIZE -I 7 -D");

vListen($IF0);

vAccept($IF0);

$cwnds[@cwnds] = 4380;
vLogHTML('<B>Now the cwnd is 4380</B><BR>');

vLogHTML('<B>================ Main Test =================</B>');

sctpUpdateRecvACK();

# This time, wen can receive four DATA messages at one time
for($i = 1; $i < 5; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

# SACK for the 1st message shoule increase the cwnd by size
vSend($IF0, sctp_chunk_sack_snd);
$cwnds[@cwnds] = $cwnds[@cwnds - 1] + $SIZE;
vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1]</B>");

# Increased cwnd let us can receive two DATA messages
for($i = 5; $i < 6; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

# SACK with Gap Report for the 2nd message shoule not increase the cwnd
vSend($IF0, sctp_chunk_sack_2);
# SACK report the 2nd message is missing
vSend($IF0, sctp_chunk_sack_3);
# SACK report the 2nd message is missing
vSend($IF0, sctp_chunk_sack_4);
# SACK report the 2nd message is missing
vSend($IF0, sctp_chunk_sack_5);

# We can receive last two DATA messages now
for($i = 6; $i < 8; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

# Do Fast Retransmit on Gap Reports 
%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_2");
if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_2") {
	vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
	vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
	exit $V6evalTool::exitFail;
}

# Upon detection of packet losses from SACK, update cwnd to max(cwnd/2, 4*MTU)
# ssthresh = 6000, partial_bytes_acked = 0
$cwnds[@cwnds] = 6000;
$pba = 0;
vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1], partial_bytes_acked = $pba</B>");
sctpUpdateRecvACK(6);
vSend($IF0, sctp_chunk_sack_snd);

#Send DATA to remote to let following DATAs can be send
sctpUpdateSendTSN();
vSend($IF0, sctp_chunk_data_snd);

sctpUpdateRecvACK();
# Five DATA messages can be send now
for($i = 1; $i < 6; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

# SACK the first 2 messages shoule increase the cwnd by 1*PMTU
sctpUpdateRecvACK(2);
vSend($IF0, sctp_chunk_sack_snd);
sctpUpdateRecvACK(-2);
$cwnds[@cwnds] = $cwnds[@cwnds - 1] + 1500;
vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1]</B>");

# Enter Congestion Avoidance
# Send DATA to remote to let DATA can be transmitted,  
# acknowledge all of the data transmitted by the sender, 
# and partial_bytes_acked is initialized to 0.
sctpUpdateSendTSN();
vSend($IF0, sctp_chunk_data_snd);

# We can receive the following two DATA messages now
for($i = 6; $i < 8; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}
# SACK the first 5 messages shoule not increase the cwnd
# partial_bytes_acked is increased by the total size of the messages
sctpUpdateRecvACK(6);
vSend($IF0, sctp_chunk_sack_snd);
$pba += $SIZE * 5;
vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1], partial_bytes_acked = $pba</B>");

sctpUpdateRecvACK();
# This time, wen can receive five DATA messages at one time
for($i = 1; $i < 7; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

# SACK for the first messages will not increase the cwnd
# partial_bytes_acked is increased by the size of messages
sctpUpdateRecvACK();
vSend($IF0, sctp_chunk_sack_snd);
sctpUpdateRecvACK(-1);
$pba += $SIZE;
if ($pba > $cwnds[@cwnds - 1]) {
	$cwnds[@cwnds] = $cwnds[@cwnds - 1] + 1500;
	$pba = ($pba > $cwnds[@cwnds - 1]) ? $pba - $cwnds[@cwnds - 1] : 0;
}

vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1], partial_bytes_acked = $pba</B>");

for($i = 7; $i < 8; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

# Send DATA to remote to let DATA can be transmitted,  
# acknowledge all of the data transmitted by the sender, 
# and partial_bytes_acked is initialized to 0.
sctpUpdateSendTSN();
vSend($IF0, sctp_chunk_data_snd);

# SACK those 6 messages shoule not increase the cwnd
# partial_bytes_acked is increased by the total size of the messages
sctpUpdateRecvACK(6);
vSend($IF0, sctp_chunk_sack_snd);
# partial_bytes_acked by the total number of bytes
$pba += $SIZE * 6;
if ($pba > $cwnds[@cwnds - 1]) {
	$cwnds[@cwnds] = $cwnds[@cwnds - 1] + 1500;
	$pba = ($pba > $cwnds[@cwnds - 1]) ? $pba - $cwnds[@cwnds - 1] : 0;
}
vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1], partial_bytes_acked = $pba</B>");

sctpUpdateRecvACK();
# Seven DATA messages can be send now
for($i = 1; $i < 8; $i++) {
	%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_$i");
	if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_$i") {
		vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}
sctpUpdateRecvACK(6);
vSend($IF0, sctp_chunk_sack_snd);
# partial_bytes_acked by the total number of bytes
$pba += $SIZE * 7;
if ($pba > $cwnds[@cwnds - 1]) {
	$cwnds[@cwnds] = $cwnds[@cwnds - 1] + 1500;
	$pba = ($pba > $cwnds[@cwnds - 1]) ? $pba - $cwnds[@cwnds - 1] : 0;
}

vLogHTML("<B>Now the cwnd is $cwnds[@cwnds - 1], partial_bytes_acked = $pba</B>");

vClose($IF0);

$cwnds[@cwnds] = '-';
@ret = sctpGetRemoteStatus(@cwnds);
for($i = 0; $i < @cwnds; $i++) {
	if((!defined($ret[$i]) && $cwnds[$i] != '-') || $cwnds[$i] != $ret[$i]) {
		vLogHTML(sprintf("The initial cwnd is not update correctly, except %s, but get %s<BR>",
					$cwnds[$i] == '-' ? "NO CHANGE" : $cwnds[$i],
					defined($ret[$i]) ? $ret[$i]: "NO CHANGE"));
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}
}

vLogHTML(OK);
exit $V6evalTool::exitPass;

END {
	# remember exit status, this maybe change after following process
	my $ret = $?;

	sctpSetRemoteSys("MAX.BURST", $MAX_BURST);

	# exit with the last exit status
	exit($ret);
}

######################################################################
__END__

=head1 NAME

  UsedCongestAvoid.seq - Increase cwnd by MTU when partial_bytes_acked is equal to or greater than cwnd

=head1 PURPOSE

  To verify that When partial_bytes_acked is equal to or greater than
  cwnd and before the arrival of the SACK the sender had cwnd or more
  bytes of data outstanding (i.e., before arrival of the SACK, flightsize
  was greater than or equal to cwnd), increase cwnd by MTU, and reset
  partial_bytes_acked to (partial_bytes_acked - cwnd).

=head1 SYNOPSIS

=begin html
<PRE>
  <A HREF="./UsedCongestAvoid.seq">./UsedCongestAvoid.seq</A> [-tooloption ...] -pkt <A HREF="./UsedCongestAvoid.def">./UsedCongestAvoid.def</A>
    -tooloption : v6eval tool option
  See Also: <A HREF="../common/STD_PKT_COMMON.def">../common/STD_PKT_COMMON.def</A>
            <A HREF="../common/SCTP_COMMON.def">../common/SCTP_COMMON.def</A>
</PRE>

=end html

=head1 PRE-TEST CONDITION

  Association is established between endpoint A and B. Arrange data 
  in endpoint B such that messages is sent to endpoint A.

=head1 TEST PROCEDURE

  Endpoint A                           Endpoint B                ULP
  (ESTABLISHED)                        (ESTABLISHED)
                                                  <-----    Send
                  <----------------       DATA 1
  Don't Send SACK  
                  <----------------       DATA 2
  Don't Send SACK  
                  <----------------       DATA 3
  Don't Send SACK  
                  <----------------       DATA 4

  SACK            ----------------->
  (For DATA 1)
                  <----------------       DATA 5
  Don't Send SACK  
                  <----------------       DATA 6
  Don't Send SACK  
  SACK            ----------------->
  (For DATA 1 and DATA 2)
  SACK            ----------------->
  (For DATA 1 and DATA 3, report DATA 2 is missing)
  SACK            ----------------->
  (For DATA 1, DATA 3 and DATA 4, report DATA 2 is missing)
  SACK            ----------------->
  (For DATA 1, DATA 3 to DATA 5, report DATA 2 is missing)
                  <----------------       DATA 2
 
                  <----------------       DATA 7
 
  SACK            ----------------->
  (For all DATAs)
  DATA            ----------------->

                  <----------------       SACK

                  <----------------       DATA 1
  Don't Send SACK  
                  <----------------       DATA 2
  Don't Send SACK  
                  <----------------       DATA 3
  Don't Send SACK  
                  <----------------       DATA 4
  Don't Send SACK  
                  <----------------       DATA 5

  SACK            ----------------->
  (For DATA 1 and DATA2)
  DATA            ----------------->

                  <----------------       SACK

                  <----------------       DATA 6

                  <----------------       DATA 7

  SACK            ----------------->
  (For all DATAs)
                  <----------------       DATA 1
  Don't Send SACK  
                  <----------------       DATA 2
  Don't Send SACK  
                  <----------------       DATA 3
  Don't Send SACK  
                  <----------------       DATA 4
  Don't Send SACK  
                  <----------------       DATA 5
  Don't Send SACK  
                  <----------------       DATA 6

  SACK            ----------------->
  (For DATA 1)
  DATA            ----------------->

                  <----------------       SACK

                  <----------------       DATA 7

  SACK            ----------------->
  (For all DATAs)
                  <----------------       DATA 1
  Don't Send SACK  
                  <----------------       DATA 2
  Don't Send SACK  
                  <----------------       DATA 3
  Don't Send SACK  
                  <----------------       DATA 4
  Don't Send SACK  
                  <----------------       DATA 5
  Don't Send SACK  
                  <----------------       DATA 6
  Don't Send SACK  
                  <----------------       DATA 7

  SACK            ----------------->
  (For all DATAs)


  TEST DESCRIPTION:

  1. Check A: the initial cwnd before DATA transmission is set to 4380.
  2. From endpoint B, send valid DATA message 4 times to endpoint A,
     when there is association between them.
  3. From endpoint A, send SACK of the first DATA message to 
     endpoint B.
  4. Check B: Congestion control window is increased by DATA size.
  5. From endpoint A, receive DATA message 2 times.
  6. From endpoint A, send SACK of the 1st, 3rd DATA messages to 
     endpoint B, report the 2nd message is missing.
  7. From endpoint A, send SACK of the 1st, 3rd and 4th DATA messages
     to endpoint B, report the 2nd message is missing.
  8. From endpoint A, send SACK of the 1st, 3rd to 5th DATA messages
     to endpoint B, report the 2nd message is missing.
  9. Check C: The 2nd DATA messages is send again immediately.
  10.Check D: Congestion control window is 6000 now.
  11.Send SACK of all DATA to endpoint B.
  12.From endpoint A, Send DATA message to endpoint and receive SACK.
  13.From endpoint A, receive DATA message 5 times.
  14.Send SACK of first two messages.
  15.Check E: Congestion control window is 7500 now.
  16.From endpoint A, Send DATA message to endpoint and receive SACK.
  17.Receive DATA message 2 times and send SACK of above DATA messages.
  18.From endpoint A, receive DATA message 6 times.
  19.Send SACK of first DATA messages, Send DATA message to endpoint
     and receive SACK.
  20.From endpoint A, receive DATA message 1 times and send SACK of 
     above DATA messages.
  21.Check E: Congestion control window is 9000 now.
  22.From endpoint A, receive DATA message 7 times.
  23.Send SACK of all the above DATA messages.
  21.Check F: Congestion control window is 10500 now.

=head1 NOTE

  None

=head1 REFERENCE

  RFC 4960

  7.2.2.  Congestion Avoidance

    When cwnd is greater than ssthresh, cwnd should be incremented by
    1*MTU per RTT if the sender has cwnd or more bytes of data
    outstanding for the corresponding transport address.

    In practice, an implementation can achieve this goal in the following
    way:

    o  partial_bytes_acked is initialized to 0.

    o  Whenever cwnd is greater than ssthresh, upon each SACK arrival
       that advances the Cumulative TSN Ack Point, increase
       partial_bytes_acked by the total number of bytes of all new chunks
       acknowledged in that SACK including chunks acknowledged by the new
       Cumulative TSN Ack and by Gap Ack Blocks.

=begin html
<PRE>
    <B>o  When partial_bytes_acked is equal to or greater than cwnd and
       before the arrival of the SACK the sender had cwnd or more bytes
       of data outstanding (i.e., before arrival of the SACK, flightsize
       was greater than or equal to cwnd), increase cwnd by MTU, and
       reset partial_bytes_acked to (partial_bytes_acked - cwnd).</B>
</PRE>

=end html

    o  Same as in the slow start, when the sender does not transmit DATA
       on a given transport address, the cwnd of the transport address
       should be adjusted to max(cwnd / 2, 4*MTU) per RTO.

    o  When all of the data transmitted by the sender has been
       acknowledged by the receiver, partial_bytes_acked is initialized
       to 0.