#!/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_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 5)",
);

$IF0 = Link0;

vCapture($IF0);

sctpCheckEnv($IF0);

$SIZE = ($SCTP::CONF{ENABLE_IPV6} == 0) ? 1452 : 1432;
$COUNT = 5;

sctpStartClient($IF0, $COUNT, $SIZE);

vListen($IF0);

vAccept($IF0);

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;
	}
}

vSend($IF0, sctp_chunk_sack_snd);

%ret = vWarpRecv($IF0, 30, 0, 0, "sctp_chunk_data_5");
if($ret{status} != 0 || $ret{recvFrame} ne "sctp_chunk_data_5") {
	vLogHTML('Cannot receive SCTP CHUNK_DATA<BR>');
	vLogHTML('<FONT COLOR="#FF0000">NG</FONT>'); 
	exit $V6evalTool::exitFail;
}

# SACK report the 2nd message is missing
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);

# Do Fast Retransmit on Gap Reports 
%ret = vWarpRecv($IF0, 5, 0, 0, "sctp_chunk_data_2");
if($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;
}

sctpUpdateRecvACK(4);
vSend($IF0, sctp_chunk_sack_snd);

vShutdown($IF0);

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

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

=head1 NAME

  FastRetranToGap.seq - TSN missing in SACK which was previously acknowledged by SACK in Gap Ack block

=head1 PURPOSE

  To check that if the SACK is missing a TSN that was previously
  acknowledged via a Gap Ack Block (e.g., the data receiver reneged
  on the data), then mark the corresponding DATA chunk as available
  for retransmit.

=head1 SYNOPSIS

=begin html
<PRE>
  <A HREF="./FastRetranToGap.seq">./FastRetranToGap.seq</A> [-tooloption ...] -pkt <A HREF="./FastRetranToGap.def">./FastRetranToGap.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  
  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
 
  SACK            ----------------->
  (For all DATAs)

  TEST DESCRIPTION:

  1. From endpoint B, send valid DATA message 5 times to endpoint A,
     when there is association between them.
  2. From endpoint A, receive DATA message 4 times.
  3. From endpoint A, send SACK of the first DATA message to 
     endpoint B.
  4. From endpoint A, send SACK of the 1st, 3rd DATA messages to 
     endpoint B, report the 2nd message is missing.
  5. From endpoint A, send SACK of the 1st, 3rd and 4th DATA messages
     to endpoint B, report the 2nd message is missing.
  6. From endpoint A, send SACK of the 1st, 3rd to 5th DATA messages
     to endpoint B, report the 2nd message is missing.
  7. Check A: The 2nd DATA messages is send again immediately.
  8. Send SACK of all the above DATA messages.

=head1 NOTE

  None

=head1 REFERENCE

  RFC 4960

  6.2.1.  Processing a Received SACK

    An endpoint SHOULD use the following rules to calculate the rwnd,
    using the a_rwnd value, the Cumulative TSN Ack, and Gap Ack Blocks in
    a received SACK.

    A) At the establishment of the association, the endpoint initializes
       the rwnd to the Advertised Receiver Window Credit (a_rwnd) the
       peer specified in the INIT or INIT ACK.

    B) Any time a DATA chunk is transmitted (or retransmitted) to a peer,
       the endpoint subtracts the data size of the chunk from the rwnd of
       that peer.

    C) Any time a DATA chunk is marked for retransmission, either via
       T3-rtx timer expiration (Section 6.3.3) or via Fast Retransmit
       (Section 7.2.4), add the data size of those chunks to the rwnd.

       Note: If the implementation is maintaining a timer on each DATA
       chunk, then only DATA chunks whose timer expired would be marked
       for retransmission.

    D) Any time a SACK arrives, the endpoint performs the following:

        i)  If Cumulative TSN Ack is less than the Cumulative TSN Ack
            Point, then drop the SACK.  Since Cumulative TSN Ack is
            monotonically increasing, a SACK whose Cumulative TSN Ack is
            less than the Cumulative TSN Ack Point indicates an out-of-
            order SACK.

        ii) Set rwnd equal to the newly received a_rwnd minus the number
            of bytes still outstanding after processing the Cumulative
            TSN Ack and the Gap Ack Blocks.

=begin html
<PRE>
       iii) <B>If the SACK is missing a TSN that was previously acknowledged
            via a Gap Ack Block (e.g., the data receiver reneged on the
            data), then consider the corresponding DATA that might be
            possibly missing: Count one miss indication towards Fast
            Retransmit as described in Section 7.2.4, and if no
            retransmit timer is running for the destination address to
            which the DATA chunk was originally transmitted, then T3-rtx
            is started for that destination address.</B>
</PRE>

=end html

        iv) If the Cumulative TSN Ack matches or exceeds the Fast
            Recovery exitpoint (Section 7.2.4), Fast Recovery is exited.