66cd81a610
"NetPacket" provides a base class for a cluster of modules related to decoding and encoding of network protocols. Each "NetPacket" descendent module knows how to encode and decode packets for the network protocol it implements. Consult the documentation for the module in question for protocol-specific implementation.
382 lines
8.7 KiB
Plaintext
382 lines
8.7 KiB
Plaintext
$OpenBSD: patch-NetPacket_IPv6_pm,v 1.1.1.1 2005/05/24 06:16:53 msf Exp $
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--- NetPacket/IPv6.pm.orig Thu Apr 14 10:10:49 2005
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+++ NetPacket/IPv6.pm Thu Apr 14 10:10:49 2005
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@@ -0,0 +1,377 @@
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+#
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+# IPv6.pm
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+# NetPacket::IPv6
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+#
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+# Decode Internet Protocol v6 packet header.
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+#
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+# References:
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+# RFC2460 - IPv6 Specification
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+#
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+# Copyright (c) 2003, 2004 Joel Knight <enabled@myrealbox.com>
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+#
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+# Permission to use, copy, modify, and distribute this software for any
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+# purpose with or without fee is hereby granted, provided that the above
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+# copyright notice and this permission notice appear in all copies.
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+#
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+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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+#
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+#
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+# $jwk: IPv6.pm,v 1.13 2004/08/06 05:12:00 jwk Exp $
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+
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+package NetPacket::IPv6;
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+
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+use strict;
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+use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
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+use NetPacket;
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+
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+my $myclass;
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+BEGIN {
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+ $myclass = __PACKAGE__;
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+ $VERSION = "0.01";
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+}
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+sub Version () { "$myclass v$VERSION" }
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+
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+BEGIN {
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+ @ISA = qw(Exporter NetPacket);
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+
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+ @EXPORT = qw( );
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+
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+ @EXPORT_OK = qw(
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+ ipv6_strip
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+ IP_PROTO_IPV6 IP_PROTO_ICMPV6
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+ IP_VERSION_IPv6 IPV6_VERSION
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+ IPV6_MAXPACKET
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+ );
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+
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+ %EXPORT_TAGS = (
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+ ALL => [@EXPORT, @EXPORT_OK],
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+ protos => [qw(IP_PROTO_IPV6 IP_PROTO_ICMPV6)],
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+ versions => [qw(IP_VERSION_IPv6 IPV6_VERSION)],
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+ strip => [qw(ipv6_strip)],
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+);
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+
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+}
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+
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+# possible 'next-header' values
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+use constant IP_PROTO_IPV6 => 41; # IPv6
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+use constant IP_PROTO_ICMPV6 => 58; # ICMPv6
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+
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+use constant IP_VERSION_IPv6 => 6;
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+use constant IPV6_VERSION => IP_VERSION_IPv6;
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+
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+# size of the ipv6 header in bytes
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+use constant IPV6_HDRLEN => 40;
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+
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+# maximum ipv6 packet size in bytes
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+use constant IPV6_MAXPACKET => 65535 + IPV6_HDRLEN;
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+
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+# convert 4, 32-bit integers to a hex string with every two bytes
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+# separated by a colon
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+sub int_to_hexstr {
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+ my @int = @_;
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+
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+ my @n;
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+ foreach my $i (0..3) {
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+ push @n, (($int[$i] & 0xffff0000) >> 16);
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+ push @n, ($int[$i] & 0x0000ffff);
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+ }
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+
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+ return sprintf("%x:%x:%x:%x:%x:%x:%x:%x", @n[0..7]);
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+}
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+
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+# convert a string of 8, 16-bit hex numbers to 4, 32-bit integers
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+sub hexstr_to_int {
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+ my @n = split m/:/, $_[0];
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+
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+ my @int;
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+ foreach my $i (0,2,4,6) {
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+ my $h = hex $n[$i];
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+ my $l = hex $n[$i+1];
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+ my $int;
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+ $int = $l & 0x0000ffff;
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+ $int = $int | (($h << 16 ) & 0xffff0000);
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+ push @int, $int;
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+ }
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+
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+ return @int;
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+}
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+
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+# decode ipv6 header, return a NetPacket::IPv6 object
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+sub decode {
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+ my $class = shift;
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+ my ($pkt, $parent, @rest) = @_;
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+ my $self = {};
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+
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+ # Class fields
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+
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+ $self->{_parent} = $parent;
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+ $self->{_frame} = $pkt;
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+
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+ # Decode packet
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+
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+ if (defined $pkt) {
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+ my ($tmp, @src, @dst);
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+
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+ ($tmp, $self->{plen}, $self->{nxt}, $self->{hlim}, @src[0..3],
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+ @dst[0..3], $self->{data}) = unpack('NncCNNNNNNNNa*', $pkt);
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+
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+ $self->{ver} = ($tmp & 0xf0000000) >> 28;
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+ $self->{class} = ($tmp & 0x0ff00000) >> 20;
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+ $self->{flow} = ($tmp & 0x000fffff);
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+
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+ $self->{src_ip} = int_to_hexstr(@src);
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+ $self->{dest_ip} = int_to_hexstr(@dst);
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+ }
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+
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+ bless ($self, $class);
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+ return $self;
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+}
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+
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+undef &ipv6_strip; # Create alias
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+*ipv6_strip = \&strip;
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+
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+# return the data portion of an ipv6 packet
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+sub strip {
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+ my ($pkt, @rest) = @_;
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+
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+ my $ipv6_obj = NetPacket::IPv6->decode($pkt);
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+ return $ipv6_obj->{data};
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+}
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+
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+# reverse the decoding process and return the raw, encoded packet.
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+# take into account any member data that may have changed.
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+sub encode {
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+ my $self = shift;
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+
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+ $self->{plen} = length $self->{data};
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+
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+ my $tmp;
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+ $tmp = $self->{flow} & 0x000fffff;
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+ $tmp = $tmp | (($self->{class} << 20) & 0x0ff00000);
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+ $tmp = $tmp | (($self->{ver} << 28) & 0xf0000000);
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+
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+ my @src = hexstr_to_int($self->{src_ip});
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+ my @dst = hexstr_to_int($self->{dest_ip});
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+
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+ my $packet = pack('NncCNNNNNNNNa*', $tmp, $self->{plen},
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+ $self->{nxt}, $self->{hlim}, @src[0..3], @dst[0..3],
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+ $self->{data});
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+
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+ return($packet);
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+}
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+
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+1;
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+
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+__END__
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+
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+
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+=head1 NAME
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+
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+C<NetPacket::IPv6> - Assembling and disassembling IPv6 (Internet
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+Protocol Version 6) packets.
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+
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+=head1 SYNOPSIS
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+
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+ use NetPacket::IPv6;
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+
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+ $ip6_obj = NetPacket::IPv6->decode($raw_pkt);
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+ $ip6_pkt = NetPacket::IPv6->encode();
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+ $ip6_data = NetPacket::IPv6::strip($raw_pkt);
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+
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+=head1 DESCRIPTION
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+
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+C<NetPacket::IPv6> provides a set of routines for assembling and
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+disassembling IPv6 (Internet Protocol Version 6) packets.
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+
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+=head2 Methods
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+
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+=over
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+
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+=item C<NetPacket::IPv6-E<gt>decode([RAW PACKET])>
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+
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+Decode the raw packet data given and return an object containing
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+instance data. This method will quite happily decode garbage input. It
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+is the responsibility of the programmer to ensure valid packet data is
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+passed to this method.
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+
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+=item C<NetPacket::IPv6-E<gt>encode()>
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+
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+Return an IPv6 packet encoded with the instance data specified. This
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+will infer the packet length automatically from the payload length.
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+
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+=back
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+
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+=head2 Functions
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+
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+=over
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+
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+=item C<NetPacket::IPv6::strip([RAW PACKET])>
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+
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+Return the encapsulated data (or payload) contained in the IPv6
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+packet. This data is suitable to be used as input for other
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+C<NetPacket::*> modules.
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+
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+This function is equivalent to creating an object using the
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+C<decode()> constructor and returning the C<data> field of that
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+object.
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+
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+=back
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+
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+=head2 Instance data
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+
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+The instance data for the C<NetPacket::IPv6> object consists of
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+the following fields.
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+
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+=over
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+
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+=item ver
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+
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+The IPv6 version number of this packet. This must always be 6.
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+
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+=item class
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+
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+The IPv6 traffic class.
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+
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+=item flow
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+
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+The IPv6 flow label.
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+
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+=item plen
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+
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+The payload length. This is the length of the payload (data); it does
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+not include the length of the packet header.
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+
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+=item nxt
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+
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+The next header. This field identifies the type of header that follows
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+the IPv6 header. It uses the same values as the IPv4 C<protocol> header.
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+
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+=item hlim
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+
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+The hop limit. Each router that handles the packet will decrement this
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+field by 1. Once the field reaches 0, the packet is discarded. Similar
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+to the C<TTL> field in the IPv4 header.
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+
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+=item src_ip
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+
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+The source IPv6 address. The address is expressed as a colon-separated
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+hex string. Leading zeros within the hex numbers are removed.
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+
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+=item dest_ip
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+
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+The destination IPv6 address. The address is expressed as a
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+colon-separated hex string. Leading zeros within the hex numbers are
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+removed.
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+
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+=item data
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+
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+The encapsulated data (payload).
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+
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+=back
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+
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+=head2 Exports
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+
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+=over
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+
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+=item default
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+
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+none
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+
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+=item exportable
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+
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+Protocols:
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+
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+ IP_PROTO_IPV6 IP_PROTO_ICMPV6
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+
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+IPv6 version number:
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+
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+ IP_VERSION_IPv6 IPV6_VERSION
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+
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+Maximum IPv6 packet size:
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+
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+ IPV6_MAXPACKET
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+
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+Strip function:
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+
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+ ipv6_strip
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+
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+=item tags
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+
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+The following tags can be used to export certain items:
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+
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+=over
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+
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+=item C<:protos>
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+
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+IP_PROTO_IPV6 IP_PROTO_ICMPV6
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+
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+=item C<:versions>
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+
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+IP_VERSION_IPv6 IPV6_VERSION
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+
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+=item C<:strip>
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+
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+The function C<ipv6_strip>
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+
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+=item C<:ALL>
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+
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+All the above exportable items
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+
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+=back
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+
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+=back
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+
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+=head1 EXAMPLE
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+
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+The following prints the source and destination IPv6 address along
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+with the value of the C<next header> field.
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+
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+ #!/usr/bin/perl -w
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+
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+ use strict;
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+ use Net::PcapUtils;
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+ use NetPacket::Ethernet qw(:strip);
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+ use NetPacket::IPv6;
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+
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+ sub process_pkt {
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+ my ($user, $hdr, $pkt) = @_;
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+
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+ my $ip6_obj = NetPacket::IPv6->decode(eth_strip($pkt));
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+ print("$ip6_obj->{src_ip} -> $ip6_obj->{dest_ip} ");
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+ print("$ip6_obj->{nxt}\n");
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+ }
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+
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+ Net::PcapUtils::loop(\&process_pkt, FILTER => 'ip6');
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+
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+=head1 TODO
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+
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+Nothing at this time.
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+
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+=head1 COPYRIGHT
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+
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+Copyright (c) 2003, 2004 Joel Knight <enabled@myrealbox.com>
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+
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+Permission to use, copy, modify, and distribute this software for any
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+purpose with or without fee is hereby granted, provided that the above
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+copyright notice and this permission notice appear in all copies.
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+
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+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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+
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+=head1 AUTHOR
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+
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+Joel Knight E<lt>enabled@myrealbox.comE<gt>
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+
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+=cut
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+
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