#!/usr/bin/perl
#
# $Copyright$
#
# $TAHI: ct/natpt/rfc2765_3.1_hoplimit.seq,v 1.4 2001/10/11 01:41:46 akisada Exp $
#

BEGIN { $V6evalTool::TestVersion = '$Name:  $'; }
use V6evalTool;
use natpt;

checkNUT(router);

# Interface 
$IF="Link0";
$IF1="Link1";
vCapture($IF);
vCapture($IF1);

%pktdesc = (
  icmp4_ttl_255      => 'Send IPv4 ICMP packet with TTL = 255',
  icmp6_hoplimit_254 => 'Recv IPv6 ICMP packet Hop Limit = 254',
  icmp4_ttl_64       => 'Send IPv4 ICMP packet with TTL = 64',
  icmp6_hoplimit_63  => 'Recv IPv6 ICMP packet Hop Limit = 63',
  icmp4_ttl_2        => 'Send IPv4 ICMP packet with TTL = 2',
  icmp6_hoplimit_1   => 'Recv IPv6 ICMP packet Hop Limit = 1',
  icmp4_ttl_1        => 'Send IPv4 ICMP packet with TTL = 1',
  icmp4_ttl_1_exceed => 'Recv IPv4 ICMP Time Exceeded (TTL = 1)',
  icmp4_ttl_0_exceed => 'Recv IPv4 ICMP Time Exceeded (TTL = 0)',

  arp_nut2tn_request => 'Recv ARP request on Link1 (TN IPv4addr)',
  arp_tn2nut_reply   => 'Send ARP reply on Link1 (TN IPv4addr)',
  ns_nut2tn_siit0    => 'Recv Neighbor Solicitation on Link0 (SIIT V6addr)',
  na_tn2nut_siit0    => 'Send Neighbor Advertisement on Link0 (SIIT V6addr)',
);

$result = $V6evalTool::exitPass;
$result += send_recv($IF1, 'icmp4_ttl_255', $IF, 'icmp6_hoplimit_254');
$result += send_recv($IF1, 'icmp4_ttl_64', $IF, 'icmp6_hoplimit_63');
$result += send_recv($IF1, 'icmp4_ttl_2', $IF, 'icmp6_hoplimit_1');
$result += send_recv($IF1, 'icmp4_ttl_1', $IF1, 'icmp4_ttl_1_exceed', 
		                                'icmp4_ttl_0_exceed');

if($result == $V6evalTool::exitPass) {
    vLogHTML("<H3>OK</H3>");
    exit $V6evalTool::exitPass;
}
if($result == $V6evalTool::exitWarn) {
    vLogHTML("<FONT COLOR=#00FF00><H3>WARN</H3></FONT>");
    exit $V6evalTool::exitWarn;
}

error:
vLogHTML("<FONT COLOR=#FF0000><H3>NG</H3></FONT>");
exit $V6evalTool::exitFail;

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

=head1 NAME

	rfc2765_3.1_hoplimit.seq - Verify IPv6 <-> IPv4 header 
        translation in accordance with RFC2765 [SIIT]

=head1 TARGET

	Router

=head1 SYNOPSIS

    rfc2765_3.1_hoplimit.seq [-tooloption ...] 
        -p rfc2765_3.1_hoplimit.def

=head1 INITIALIZATION

=begin html
<PRE>
	Before this test starts, run <A HREF="./initialize.html">initialize.seq</A>.
</PRE>

=end html

=head1 TEST PROCEDURE

	This test verifies that NUT properly translates TTL - 1 to 
        Hop Limit, or sends an ICMPv4 Time Exceeded.
	
	Network Topology

	Link0
	--------------------------
	    |               |
	   TN              NUT
	    |               |
	--------------------------
	Link1

	TN -- (Link0) -- NUT        NUT -- (Link1) -- TN
	
	---------------------      ------------------------

=begin html <HR WIDTH=80%>

	1.1.
                                   <===================
	ICMPv4 Echo request
                IPv4 Header
			src address : TN LINK1 IPv4 address
			dst address : TN LINK0 IPv4 address
                        Don't Fragment = 1
                        More fragments = 0
                        Offset = 0
                        TTL = 255
                ICMPv4 echo request

	1.2.
	<<JUDGMENT>>
	<===================
	ICMPv6 Echo Request
		IPv6 Header
			src address : TN LINK1 IPv4 embedded IPv6 address
			dst address : TN LINK0 IPv4 embedded IPv6 address
                        Hop Limit = 254
                ICMPv6 echo request

=begin html <HR WIDTH=80%>

	2.1.
                                   <===================
	ICMPv4 Echo request
                IPv4 Header
			src address : TN LINK1 IPv4 address
			dst address : TN LINK0 IPv4 address
                        Don't Fragment = 1
                        More fragments = 0
                        Offset = 0
                        TTL = 64
                ICMPv4 echo request

	2.2.
	<<JUDGMENT>>
	<===================
	ICMPv6 Echo Request
		IPv6 Header
			src address : TN LINK1 IPv4 embedded IPv6 address
			dst address : TN LINK0 IPv4 embedded IPv6 address
                        Hop Limit = 63
                ICMPv6 echo request

=begin html <HR WIDTH=80%>

	3.1.
                                   <===================
	ICMPv4 Echo request
                IPv4 Header
			src address : TN LINK1 IPv4 address
			dst address : TN LINK0 IPv4 address
                        Don't Fragment = 1
                        More fragments = 0
                        Offset = 0
                        TTL = 2
                ICMPv4 echo request

	3.2.
	<<JUDGMENT>>
	<===================
	ICMPv6 Echo Request
		IPv6 Header
			src address : TN LINK1 IPv4 embedded IPv6 address
			dst address : TN LINK0 IPv4 embedded IPv6 address
                        Hop Limit = 1
                ICMPv6 echo request

=begin html <HR WIDTH=80%>

	4.1.
                                   <===================
	ICMPv4 Echo request
                IPv4 Header
			src address : TN LINK1 IPv4 address
			dst address : TN LINK0 IPv4 address
                        Don't Fragment = 1
                        More fragments = 0
                        Offset = 0
                        TTL = 1
                ICMPv4 echo request

	4.2.
	<<JUDGMENT>>
                                    ===================>
	ICMPv4 Time Exceeded
                IPv4 Header
			src address : NUT LINK1 IPv4 address
			dst address : TN LINK1 IPv4 address
                ICMPv4 Time Exceeded
                        Code = 0
                        Data = ICMPv4 Echo Request, TTL = 1

=head1 JUDGMENT

	<< PASS >>
		NUT translates ICMPv4 with TTL = 255, 64, 2 to ICMPv6
                with Hop Limit = 254, 63, 1.
                NUT responds to ICMPv4 Echo Request with TTL = 1
                with an ICMPv4 Time Exceeded message.
		
	<< FAIL >>	
		NUT doesn't translate TTL properly, or doesn't respond
                with ICMPv4 Time Exceeded messages when TTL = 1 on 
                incoming packages.

=head1 NOTE

=head1 REFERENCE

B<RFC2765>

3.1.  Translating IPv4 Headers into IPv6 Headers

         Hop Limit:
                 TTL value copied from IPv4 header.  Since the
                 translator is a router, as part of forwarding the
                 packet it needs to decrement either the IPv4 TTL
                 (before the translation) or the IPv6 Hop Limit (after
                 the translation).  As part of decrementing the TTL or
                 Hop Limit the translator (as any router) needs to
                 check for zero and send the ICMPv4 or ICMPv6 "ttl
                 exceeded" error.


=head1 SEE ALSO

	perldoc V6evalTool

=cut