#!/usr/bin/perl
#
# $Copyright_v6PC$
#
# $Copyright$
#
# $TAHI: ct/spec/FH_Needless.seq,v 1.11 2004/04/02 03:47:50 kenta Exp $
#
######################################################################
BEGIN {
	$V6evalTool::TestVersion = '$Name:  $';
}

use V6evalTool;

%pktdesc = (
	echo_request		=> 'Send Echo Request (Preparation)',
	echo_reply		=> 'Recv Echo Reply',
	ns			=> 'Recv Neighbor Solicitation',
	na			=> 'Send Neighbor Advertisement',
	echo_request_all	=> 'Send Echo Request (Offset 0, MFlag 0)',
	unicast_ns		=> 'Recv Unicast Neighbor Solicitation',
	unicast_ns_wsll		=> 'Recv Unicast Neighbor Solicitation (without SLL)',
);

%nd = (
	'ns'		=> 'Recv Neighbor Solicitation',
	'unicast_ns'	=> 'Recv Unicast Neighbor Solicitation',
	'unicast_ns_wsll'=> 'Recv Unicast Neighbor Solicitation (without SLL)',
);

$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;
}

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

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

%ret = vRecv($IF, 5, 0, 0, sort(keys(%nd)), echo_reply);
if ($ret{status} == 0 && $ret{recvFrame} ne 'echo_reply') {
	while(($recv, $send) = each(%nd)){
		if ($ret{recvFrame} eq $recv) {
			vSend($IF, na);
			%ret = vRecv($IF, 5, 0, 0, echo_reply);
			last;
		}
	}
}
if ($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_Needless - check Fragment Reassembly (Offset = 0, MFlag = 0)

=head1 TARGET

  Host and Router

=head1 SYNOPSIS

=begin html
<PRE>
  <A HREF="./FH_Needless.seq">FH_Needless.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            |
    |                           |
    |                           |
    |<--------------------------|
    |   Echo Reply              |
    |                           |
    |                           |
    v                           v


  1. Send Echo Request (fragment offset = 0, MFlag = 0)
  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 (Offset 0, MFlag 0) is:

        IPv6 Header
            Version            = 6
            Traffic Class      = 0
            FlowLabel          = 0
            PayloadLength      = 1040
            NextHeader         = 44 (Fragment Header)
            SourceAddress      = Tester Link Local Address
            DestinationAddress = Target Link Local Address

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

        Payload
            data               = 1032 octets from the head 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

                   :

   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.

=begin html
<PRE>
      <B>(2) A Fragment header containing:
<BR>
               The Next Header value that identifies the first header of
               the Fragmentable Part of the original packet.
<BR>
               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.
<BR>
               An M flag value of 0 if the fragment is the last 
               ("rightmost") one, else an M flag value of 1.
<BR>
               The Identification value generated for the original   
               packet.</B>
</PRE>

=end html

      (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  | 2-bit reserved fFragmentablealized to zero for |
   |       Part       | transmission; ignorePart                       |
   +------------------+----------------------//------------------------+
  
   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.

=head1 SEE ALSO

  perldoc V6evalTool

=cut