#!/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 = ();

$IF0 = Link0;

vCapture($IF0);

sctpCheckEnv($IF0);

$RTO = $SCTP::CONF{"RTO_INITIAL"};
$RTO_MAX = $SCTP::CONF{"RTO_MAX"};
$ASSOC_MAX_RETRANS = $SCTP::CONF{"ASSOCIATION_MAX_RETRANS"};

sctpStartClient($IF0);

vListen($IF0);

vAccept($IF0);

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

sctpUpdateRecvACK();

# Start Receive First Data
%ret = vWarpRecv($IF0, 10, 0, 0, sctp_chunk_data_rcv);
if($ret{status} != 0 || $ret{recvFrame} ne sctp_chunk_data_rcv) {
	vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
	vLogHTML('<FONT COLOR="#00FF00">NG</FONT>'); 
	exit $V6evalTool::exitFail;
}

$stime = $ret{"recvTime".$ret{"recvCount"}};
$count = 0;

while ($count < $ASSOC_MAX_RETRANS) {
	# Don't send SACK, Data will be retransmitted after RTO
	%ret = vWarpRecv($IF0, $RTO + 5, 0, 0, sctp_chunk_data_rcv);
	if($ret{status} != 0 || $ret{recvFrame} ne sctp_chunk_data_rcv) {
		vSend($IF0, sctp_chunk_abort_snd);
		vLogHTML("ERROR: The retransmit T3-rxt time received:$gap, but expected: $RTO<BR>");
		vLogHTML('<FONT COLOR="#00FF00">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}

	$etime = $ret{"recvTime".$ret{"recvCount"}};
	$gap = $etime - $stime;

	if (!sctpTimeFuzzyEqual($gap, $RTO, $SCTP::CONF{"TIME_PREC"})) {
		# We got a bad time
		vSend($IF0, sctp_chunk_abort_snd);
		vLogHTML("ERROR: The retransmit T3-rxt time received:$gap, but expected: $RTO<BR>");
		vLogHTML('<FONT COLOR="#00FF00">NG</FONT>'); 
		exit $V6evalTool::exitFail;
	}

	vLogHTML("OK: The retransmit T3-rxt timer received:$gap, expected: $RTO<BR>");

	last if ($RTO == $RTO_MAX);

	$stime = $etime;
	$RTO = $RTO * 2; # back off the timer
	$RTO = $RTO_MAX if ($RTO > $RTO_MAX);
	$count++;
}

vSend($IF0, sctp_chunk_sack_snd);

vShutdown($IF0);

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

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

=head1 NAME

  T3ExpiresRTOInc.seq - RTO is updated correctly if T3-rxt timer expires for a DATA message

=head1 PURPOSE

  To check that if T3-rxt expires on a destination address then the
  value of RTO is updated correctly for that address.

=head1 SYNOPSIS

=begin html
<PRE>
  <A HREF="./T3ExpiresRTOInc.seq">./T3ExpiresRTOInc.seq</A> [-tooloption ...] -pkt <A HREF="./T3ExpiresRTOInc.def">./T3ExpiresRTOInc.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 the data
  in endpoint A such that SACK is not sent for the data received from
  endpoint B.

=head1 TEST PROCEDURE

  Endpoint A                           Endpoint B                ULP
  (ESTABLISHED)                        (ESTABLISHED)

                                                   <-----    Send
                <----------------       DATA
                                        (Start T3-rtx timer)
                                          |
                                          | T3-rtx timer expired
                                          |
                <----------------       DATA
                                          |
                                          | T3-rtx timer expired
                                          |
                <----------------       DATA
                                          .
                                          . Retransmit x
                                          . times
  TEST DESCRIPTION:

  1. Attempt to send DATA from endpoint B to A. Don't send SACK from A.
     Let the timer T3-rxt expire. DATA will be retransmitted. Note the
     timer. Don't send SACK for the retransmitted DATA. T3-rxt will be 
     expired again and again DATA will be retransmitted. 
     Record the messages using a signal emulator.
  2. Check A: Value of the T3-rxt is updated correctly. 

=head1 NOTE

  1. If configure of ASSOC_MAX_RETRANS is not lager enough, test will exit
     even if RTO is not up to RTO_MAX.
  2. If the retransmit time is 0.5s less or greater than RTO, do accept it
     because we can not exactly calculate it.

=head1 REFERENCE

  RFC 4960

  6.3.3.  Handle T3-rtx Expiration

    Whenever the retransmission timer T3-rtx expires for a destination
    address, do the following:

    E1)  For the destination address for which the timer expires, adjust
         its ssthresh with rules defined in Section 7.2.3 and set the
         cwnd <- MTU.

=begin html
<PRE>
    <B>E2)  For the destination address for which the timer expires, set RTO
         <- RTO * 2 ("back off the timer").  The maximum value discussed
         in rule C7 above (RTO.max) may be used to provide an upper bound
         to this doubling operation.</B>
</PRE>

=end html

    E3)  Determine how many of the earliest (i.e., lowest TSN)
         outstanding DATA chunks for the address for which the T3-rtx has
         expired will fit into a single packet, subject to the MTU
         constraint for the path corresponding to the destination
         transport address to which the retransmission is being sent
         (this may be different from the address for which the timer
         expires; see Section 6.4).  Call this value K.  Bundle and
         retransmit those K DATA chunks in a single packet to the
         destination endpoint.

    E4)  Start the retransmission timer T3-rtx on the destination address
         to which the retransmission is sent, if rule R1 above indicates
         to do so.  The RTO to be used for starting T3-rtx should be the
         one for the destination address to which the retransmission is
         sent, which, when the receiver is multi-homed, may be different
         from the destination address for which the timer expired (see
         Section 6.4 below).