#!/usr/bin/perl
#
# Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005 Yokogawa Electric Corporation,
# IPA (Information-technology Promotion Agency, Japan).
# All rights reserved.
# 
# Redistribution and use of this software in source and binary forms, with 
# or without modification, are permitted provided that the following 
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# 
# 1. Redistributions of source code must retain the above copyright 
# notice, this list of conditions and the following disclaimer.
# 
# 2. Redistributions in binary form must reproduce the above copyright 
# notice, this list of conditions and the following disclaimer in the 
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# 
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# is related to this software (hereinafter referred to as "project") nor 
# the names of the contributors may be used to endorse or promote products 
# derived from this software without specific prior written permission.
# 
# 4. No merchantable use may be permitted without prior written 
# notification to the copyrighters. However, using this software for the 
# purpose of testing or evaluating any products including merchantable 
# products may be permitted without any notification to the copyrighters.
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# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHTERS, THE PROJECT AND 
# CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING 
# BUT NOT LIMITED THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
# FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.  IN NO EVENT SHALL THE 
# COPYRIGHTERS, THE PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
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# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
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# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
# CONTRACT,STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 
# THE POSSIBILITY OF SUCH DAMAGE.
#
# $TAHI: ct/spec/FH_Normal.seq,v 1.20 2003/06/09 07:39:43 ozoe Exp $
#
######################################################################
BEGIN {
	$V6evalTool::TestVersion = '$Name: REL_2_1_2 $';
}

use V6evalTool;

%pktdesc = (
	echo_request		=> 'Send Echo Request (Preparation)',
	echo_reply		=> 'Recv Echo Reply',
	ns			=> 'Recv Neighbor Solicitation',
	na			=> 'Send Neighbor Advertisement',
	echo_request_1st	=> 'Send Echo Request (1st fragment)',
	echo_request_2nd	=> 'Send Echo Request (2nd fragment)',
);

$IF = Link0;

vCapture($IF);

#----- preparation

vLogHTML('<B>Begin Preparation</B>');

vSend($IF, echo_request);

%ret = vRecv($IF, 5, 0, 0, ns, echo_reply);
if ($ret{status} != 0) {
	vLogHTML('<FONT COLOR="#FF0000">NG</FONT>');
	exit $V6evalTool::exitFail;
}
if ($ret{recvFrame} eq 'ns') {
	vSend($IF, na);
	%ret = vRecv($IF, 5, 0, 0, echo_reply);
	if ($ret{status} != 0) {
		vLogHTML('<FONT COLOR="#FF0000">NG</FONT>');
		exit $V6evalTool::exitFail;
	}
}
if ($ret{recvFrame} ne 'echo_reply') {
	vLogHTML('<FONT COLOR="#FF0000">NG</FONT>');
	exit $V6evalTool::exitFail;
}

vSend($IF, na);

vLogHTML('<B>End Preparation</B>');

#----- main test
vSend($IF, echo_request_1st);

vSend($IF, echo_request_2nd);

%ret = vRecv($IF, 5, 0, 0, echo_reply);
if ($ret{status} == 0 && $ret{recvFrame} eq 'echo_reply') {
	vLogHTML('OK');
	exit $V6evalTool::exitPass;
}

vLogHTML('<FONT COLOR="#FF0000">NG</FONT>');
vSleep(65, "Discard Unexpected 'ICMP Time Exceeded' message (60+5 sec)");
exit $V6evalTool::exitFail;



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

=head1 NAME

  FH_Normal - check Fragment Reassembly (normal order)

=head1 TARGET

  Host and Router

=head1 SYNOPSIS

=begin html
<PRE>
  <A HREF="./FH_Normal.seq">FH_Normal.seq</A> [-tooloption ...] -pkt <A HREF="./Fragment.def">Fragment.def</A>
    -tooloption : v6eval tool option
</PRE>

=end html

=head1 INITIALIZATION

  1. Ping to Target (create Neighbor Cache Entries, if not exist)
  2. Override Neighbor Cache Entries

=head1 TEST PROCEDURE

  Tester                      Target
    |                           |
    |-------------------------->|
    |   Echo Request (1st)      |
    |                           |
    |                           |
    |-------------------------->|
    |   Echo Request (2nd)      |
    |                           |
    |                           |
    |<--------------------------|
    |   Echo Reply              |
    |                           |
    |                           |
    v                           v


  1. Send Echo Request (1st fragment)
  2. Send Echo Request (2nd fragment)
  3. Receive Echo Reply

  Echo Request Data (original) is:

        IPv6 Header
            Version            = 6
            Traffic Class      = 0
            FlowLabel          = 0
            PayloadLength      = 1032
            NextHeader         = 58 (ICMP)
            SourceAddress      = Tester Link Local Address
            DestinationAddress = Target Link Local Address

        ICMP Echo Request
            Type           = 128 (Echo Request)
            Code           = 0
            Checksum       = (auto)
            Identifier     = (auto)
            SequenceNumber = 0
            PayloadData    = data repeat{0x1, 512}
                             data repeat{0x2, 512}

  Echo Request Data (1st fragment) is:

        IPv6 Header
            Version            = 6
            Traffic Class      = 0
            FlowLabel          = 0
            PayloadLength      = 528
            NextHeader         = 44 (Fragment Header)
            SourceAddress      = Tester Link Local Address
            DestinationAddress = Target Link Local Address

        Fragment Header
            NextHeader         = 58 (ICMP)
            FragmentOffset     = 0
            MFlag              = 1
            Identification     = 32bit (Automatic generation)

        Payload
            data               = 520 octets from the head of ICMP Echo request

  Echo Request Data (2nd fragment) is:

        IPv6 Header
            Version            = 6
            Traffic Class      = 0
            FlowLabel          = 0
            PayloadLength      = 520
            NextHeader         = 44 (Fragment Header)
            SourceAddress      = Tester Link Local Address
            DestinationAddress = Target Link Local Address

        Fragment Header
            NextHeader         = 58 (ICMP)
            FragmentOffset     = 65
            MFlag              = 0
            Identification     = 32bit (Automatic generation)

        Payload
            data               = 512 octets from the back of ICMP Echo request

=head1 JUDGMENT

  PASS: Echo Reply Received

        IPv6 Header
            Version             = 6
            Traffic Class       = 0
            FlowLabel           = 0
            PayloadLength       = 1032
            NextHeader          = 58 (ICMP)
            SourceAddress       = Target Link Local Address
            Destination Address = Tester Link Local Address

        ICMP Echo Reply
            Type           = 129 (Echo Reply)
            Code           = 0
            Checksum       = (auto)
            Identifier     = (same as Echo Request)
            SequenceNumber = (same as Echo Request)
            PayloadData    = (same as Echo Request)

=head1 REFERENCE

RFC2460

4.5  Fragment Header

   The Fragment header is used by an IPv6 source to send a packet larger
   than would fit in the path MTU to its destination.  (Note: unlike
   IPv4, fragmentation in IPv6 is performed only by source nodes, not by
   routers along a packet's delivery path -- see section 5.)  The
   Fragment header is identified by a Next Header value of 44 in the
   immediately preceding header, and has the following format:

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Next Header  |   Reserved    |      Fragment Offset    |Res|M|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Identification                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Next Header          8-bit selector.  Identifies the initial header
                        type of the Fragmentable Part of the original
                        packet (defined below).  Uses the same values as
                        the IPv4 Protocol field [RFC-1700 et seq.].

   Reserved             8-bit reserved field.  Initialized to zero for
                        transmission; ignored on reception.

   Fragment Offset      13-bit unsigned integer.  The offset, in 8-octet
                        units, of the data following this header,
                        relative to the start of the Fragmentable Part
                        of the original packet.

   Res                  2-bit reserved field.  Initialized to zero for
                        transmission; ignored on reception.

   M flag               1 = more fragments; 0 = last fragment.

   Identification       32 bits.  See description below.

   In order to send a packet that is too large to fit in the MTU of the
   path to its destination, a source node may divide the packet into
   fragments and send each fragment as a separate packet, to be
   reassembled at the receiver.

   For every packet that is to be fragmented, the source node generates
   an Identification value. The Identification must be different than
   that of any other fragmented packet sent recently* with the same
   Source Address and Destination Address.  If a Routing header is
   present, the Destination Address of concern is that of the final
   destination.

      * "recently" means within the maximum likely lifetime of a packet,
        including transit time from source to destination and time spent
        awaiting reassembly with other fragments of the same packet.
        However, it is not required that a source node know the maximum
        packet lifetime.  Rather, it is assumed that the requirement can
        be met by maintaining the Identification value as a simple, 32-
        bit, "wrap-around" counter, incremented each time a packet must
        be fragmented.  It is an implementation choice whether to
        maintain a single counter for the node or multiple counters,
        e.g., one for each of the node's possible source addresses, or
        one for each active (source address, destination address)
        combination.

   The initial, large, unfragmented packet is referred to as the
   "original packet", and it is considered to consist of two parts, as
   illustrated:

   original packet:

   +------------------+----------------------//-----------------------+
   |  Unfragmentable  |                 Fragmentable                  |
   |       Part       |                     Part                      |
   +------------------+----------------------//-----------------------+

      The Unfragmentable Part consists of the IPv6 header plus any
      extension headers that must be processed by nodes en route to the
      destination, that is, all headers up to and including the Routing
      header if present, else the Hop-by-Hop Options header if present,
      else no extension headers.

      The Fragmentable Part consists of the rest of the packet, that is,
      any extension headers that need be processed only by the final
      destination node(s), plus the upper-layer header and data.

   The Fragmentable Part of the original packet is divided into
   fragments, each, except possibly the last ("rightmost") one, being an
   integer multiple of 8 octets long.  The fragments are transmitted in
   separate "fragment packets" as illustrated:

   original packet:

   +------------------+--------------+--------------+--//--+----------+
   |  Unfragmentable  |    first     |    second    |      |   last   |
   |       Part       |   fragment   |   fragment   | .... | fragment |
   +------------------+--------------+--------------+--//--+----------+
   fragment packets:

   +------------------+--------+--------------+
   |  Unfragmentable  |Fragment|    first     |
   |       Part       | Header |   fragment   |
   +------------------+--------+--------------+

   +------------------+--------+--------------+
   |  Unfragmentable  |Fragment|    second    |
   |       Part       | Header |   fragment   |
   +------------------+--------+--------------+
                         o
                         o
                         o
   +------------------+--------+----------+
   |  Unfragmentable  |Fragment|   last   |
   |       Part       | Header | fragment |
   +------------------+--------+----------+

   Each fragment packet is composed of:

      (1) The Unfragmentable Part of the original packet, with the
          Payload Length of the original IPv6 header changed to contain
          the length of this fragment packet only (excluding the length
          of the IPv6 header itself), and the Next Header field of the
          last header of the Unfragmentable Part changed to 44.

      (2) A Fragment header containing:

               The Next Header value that identifies the first header of
               the Fragmentable Part of the original packet.

               A Fragment Offset containing the offset of the fragment,
               in 8-octet units, relative to the start of the
               Fragmentable Part of the original packet.  The Fragment
               Offset of the first ("leftmost") fragment is 0.

               An M flag value of 0 if the fragment is the last
               ("rightmost") one, else an M flag value of 1.

               The Identification value generated for the original
               packet.

      (3) The fragment itself.

   The lengths of the fragments must be chosen such that the resulting
   fragment packets fit within the MTU of the path to the packets'
   destination(s).

   At the destination, fragment packets are reassembled into their
   original, unfragmented form, as illustrated:

   reassembled original packet:

   +------------------+----------------------//------------------------+
   |  Unfragmentable  |                 Fragmentable                   |
   |       Part       |                     Part                       |
   +------------------+----------------------//------------------------+

   The following rules govern reassembly:

      An original packet is reassembled only from fragment packets that
      have the same Source Address, Destination Address, and Fragment
      Identification.

      The Unfragmentable Part of the reassembled packet consists of all
      headers up to, but not including, the Fragment header of the first
      fragment packet (that is, the packet whose Fragment Offset is
      zero), with the following two changes:

         The Next Header field of the last header of the Unfragmentable
         Part is obtained from the Next Header field of the first
         fragment's Fragment header.

         The Payload Length of the reassembled packet is computed from
         the length of the Unfragmentable Part and the length and offset
         of the last fragment.  For example, a formula for computing the
         Payload Length of the reassembled original packet is:

           PL.orig = PL.first - FL.first - 8 + (8 * FO.last) + FL.last

           where
           PL.orig  = Payload Length field of reassembled packet.
           PL.first = Payload Length field of first fragment packet.
           FL.first = length of fragment following Fragment header of
                      first fragment packet.
           FO.last  = Fragment Offset field of Fragment header of
                      last fragment packet.
           FL.last  = length of fragment following Fragment header of
                      last fragment packet.

      The Fragmentable Part of the reassembled packet is constructed
      from the fragments following the Fragment headers in each of the
      fragment packets.  The length of each fragment is computed by
      subtracting from the packet's Payload Length the length of the
      headers between the IPv6 header and fragment itself; its relative
      position in Fragmentable Part is computed from its Fragment Offset
      value.

      The Fragment header is not present in the final, reassembled
      packet.

   The following error conditions may arise when reassembling fragmented
   packets:

      If insufficient fragments are received to complete reassembly of a
      packet within 60 seconds of the reception of the first-arriving
      fragment of that packet, reassembly of that packet must be
      abandoned and all the fragments that have been received for that
      packet must be discarded.  If the first fragment (i.e., the one
      with a Fragment Offset of zero) has been received, an ICMP Time
      Exceeded -- Fragment Reassembly Time Exceeded message should be
      sent to the source of that fragment.

      If the length of a fragment, as derived from the fragment packet's
      Payload Length field, is not a multiple of 8 octets and the M flag
      of that fragment is 1, then that fragment must be discarded and an
      ICMP Parameter Problem, Code 0, message should be sent to the
      source of the fragment, pointing to the Payload Length field of
      the fragment packet.

      If the length and offset of a fragment are such that the Payload
      Length of the packet reassembled from that fragment would exceed
      65,535 octets, then that fragment must be discarded and an ICMP
      Parameter Problem, Code 0, message should be sent to the source of
      the fragment, pointing to the Fragment Offset field of the
      fragment packet.

   The following conditions are not expected to occur, but are not
   considered errors if they do:

      The number and content of the headers preceding the Fragment
      header of different fragments of the same original packet may
      differ.  Whatever headers are present, preceding the Fragment
      header in each fragment packet, are processed when the packets
      arrive, prior to queueing the fragments for reassembly.  Only
      those headers in the Offset zero fragment packet are retained in
      the reassembled packet.

      The Next Header values in the Fragment headers of different
      fragments of the same original packet may differ.  Only the value
      from the Offset zero fragment packet is used for reassembly.

=head1 SEE ALSO

  perldoc V6evalTool

=cut