#!/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);

sctpStartClient($IF0);

vListen($IF0);

vAccept($IF0);

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

sctpUpdateRecvACK();

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

sctpUpdateRecvACK(-1);
vSend($IF0, sctp_chunk_sack_snd);

vRecvMsg($IF0);

vShutdown($IF0);

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

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

=head1 NAME

  TSNLessThanAckPoint.seq - SACK containing Cumulative TSN less than the Cumulative TSN Ack point

=head1 PURPOSE

  To check that if SACK containing Cumulative TSN Ack is less than
  the Cumulative TSN Ack Point, the endpoint should drop the SACK.

=head1 SYNOPSIS

=begin html
<PRE>
  <A HREF="./TSNLessThanAckPoint.seq">./TSNLessThanAckPoint.seq</A> [-tooloption ...] -pkt <A HREF="./TSNLessThanAckPoint.def">./TSNLessThanAckPoint.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 A such that SACK containing Cumulative TSN less than
  the Cumulative TSN Ack point is sent to endpoint A.

=head1 TEST PROCEDURE

  Endpoint A                           Endpoint B                ULP
  (ESTABLISHED)                        (ESTABLISHED)

                                                   <-----    Send
                <-----------------      DATA

  SACK          ----------------->
  (containing Cumulative TSN less than the Cumulative TSN Ack point)
                <-----------------      DATA

  SACK          ----------------->

  TEST DESCRIPTION:

  1. From endpoint B, send valid DATA message to endpoint A,
     when there is association between them.
  2. From endpoint A, send SACK which containing Cumulative
     TSN less than the Cumulative TSN Ack point.
  3. Check A: SACK message is dropped and DATA message is send
     again.

=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:

=begin html
<PRE>
        i)  <B>If Cumulative TSN Ack is less than the Cumulative TSN Ack
            Point, then drop the SACK.</B>  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.
</PRE>

=end html

        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.

       iii) 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.

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