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- Committer: Bazaar Package Importer
- Author(s): Cajus Pollmeier
- Date: 2009-06-24 10:11:00 UTC
- Revision ID: james.westby@ubuntu.com-20090624101100-mysadcke1taprhap
Tags: upstream-0.04
Import upstream version 0.04
added
removed
NetPacket/Ethernet.pm
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#
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# NetPacket::Ethernet - Decode and encode ethernet packets.
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#
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# Comments/suggestions to tpot@samba.org
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#
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# $Id: Ethernet.pm,v 1.12 2001/07/29 23:45:00 tpot Exp $
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#
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package NetPacket::Ethernet;
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#
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# Copyright (c) 2001 Tim Potter.
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#
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# This package is free software and is provided "as is" without express
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# or implied warranty. It may be used, redistributed and/or modified
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# under the terms of the Perl Artistic License (see
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# http://www.perl.com/perl/misc/Artistic.html)
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#
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# Copyright (c) 1995,1996,1997,1998,1999 ANU and CSIRO on behalf of
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# the participants in the CRC for Advanced Computational Systems
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# ('ACSys').
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#
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# ACSys makes this software and all associated data and documentation
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# ('Software') available free of charge. You may make copies of the
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# Software but you must include all of this notice on any copy.
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#
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# The Software was developed for research purposes and ACSys does not
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# warrant that it is error free or fit for any purpose. ACSys
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# disclaims any liability for all claims, expenses, losses, damages
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# and costs any user may incur as a result of using, copying or
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# modifying the Software.
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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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my $myclass;
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BEGIN {
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$myclass = __PACKAGE__;
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$VERSION = "0.04";
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}
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sub Version () { "$myclass v$VERSION" }
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BEGIN {
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@ISA = qw(Exporter NetPacket);
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# Items to export into callers namespace by default
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# (move infrequently used names to @EXPORT_OK below)
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@EXPORT = qw(
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);
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# Other items we are prepared to export if requested
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@EXPORT_OK = qw(eth_strip
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ETH_TYPE_IP ETH_TYPE_ARP ETH_TYPE_APPLETALK
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ETH_TYPE_SNMP ETH_TYPE_IPv6 ETH_TYPE_PPP
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);
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# Tags:
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%EXPORT_TAGS = (
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ALL => [@EXPORT, @EXPORT_OK],
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strip => [qw(eth_strip)],
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types => [qw(ETH_TYPE_IP ETH_TYPE_ARP ETH_TYPE_APPLETALK
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ETH_TYPE_SNMP ETH_TYPE_IPv6 ETH_TYPE_PPP)],
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);
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}
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#
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# Partial list of ethernet protocol types from
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# http://www.isi.edu/in-notes/iana/assignments/ethernet-numbers
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#
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use constant ETH_TYPE_IP => 0x0800;
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use constant ETH_TYPE_ARP => 0x0806;
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use constant ETH_TYPE_APPLETALK => 0x809b;
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use constant ETH_TYPE_RARP => 0x8035;
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use constant ETH_TYPE_SNMP => 0x814c;
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use constant ETH_TYPE_IPv6 => 0x86dd;
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use constant ETH_TYPE_PPP => 0x880b;
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#
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# Decode the packet
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#
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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 $self = {};
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# Class fields
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$self->{_parent} = $parent;
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$self->{_frame} = $pkt;
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# Decode ethernet packet
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if (defined($pkt)) {
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my($sm_lo, $sm_hi, $dm_lo, $dm_hi);
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($dm_hi, $dm_lo, $sm_hi, $sm_lo, $self->{type}, $self->{data}) =
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unpack('NnNnna*' , $pkt);
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# Convert MAC addresses to hex string to avoid representation
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# problems
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$self->{src_mac} = sprintf("%08x%04x", $sm_hi, $sm_lo);
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$self->{dest_mac} = sprintf("%08x%04x", $dm_hi, $dm_lo);
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}
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# Return a blessed object
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bless($self, $class);
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return $self;
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}
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#
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# Strip header from packet and return the data contained in it
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#
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undef ð_strip; # Create eth_strip alias
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*eth_strip = \&strip;
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sub strip {
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my ($pkt, @rest) = @_;
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my $eth_obj = NetPacket::Ethernet->decode($pkt);
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return $eth_obj->{data};
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}
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#
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# Encode a packet - not implemented!
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#
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sub encode {
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die("Not implemented");
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}
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#
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# Module initialisation
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#
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1;
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# autoloaded methods go after the END token (&& pod) below
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__END__
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=head1 NAME
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C<NetPacket::Ethernet> - Assemble and disassemble ethernet packets.
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=head1 SYNOPSIS
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use NetPacket::Ethernet;
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$eth_obj = NetPacket::Ethernet->decode($raw_pkt);
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$eth_pkt = NetPacket::Ethernet->encode(params...); # Not implemented
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$eth_data = NetPacket::Ethernet::strip($raw_pkt);
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=head1 DESCRIPTION
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C<NetPacket::Ethernet> provides a set of routines for assembling and
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disassembling packets using the Ethernet protocol.
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=head2 Methods
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=over
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=item C<NetPacket::Ethernet-E<gt>decode([RAW PACKET])>
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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.
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It is the responsibility of the programmer to ensure valid packet data
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is passed to this method.
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=item C<NetPacket::Ethernet-E<gt>encode(param =E<gt> value)>
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Return an ethernet packet encoded with the instance data specified.
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Not implemented.
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=back
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=head2 Functions
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=over
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=item C<NetPacket::Ethernet::strip([RAW PACKET])>
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Return the encapsulated data (or payload) contained in the ethernet
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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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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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=back
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=head2 Instance data
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The instance data for the C<NetPacket::Ethernet> object consists of
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the following fields.
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=over
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=item src_mac
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The source MAC address for the ethernet packet as a hex string.
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=item dest_mac
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The destination MAC address for the ethernet packet as a hex string.
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=item type
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The protocol type for the ethernet packet.
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=item data
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The payload for the ethernet packet.
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=back
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=head2 Exports
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=over
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=item default
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none
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=item exportable
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ETH_TYPE_IP ETH_TYPE_ARP ETH_TYPE_APPLETALK ETH_TYPE_SNMP
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ETH_TYPE_IPv6 ETH_TYPE_PPP
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=item tags
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The following tags group together related exportable items.
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=over
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=item C<:types>
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ETH_TYPE_IP ETH_TYPE_ARP ETH_TYPE_APPLETALK ETH_TYPE_SNMP
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ETH_TYPE_IPv6 ETH_TYPE_PPP
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=item C<:strip>
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Import the strip function C<eth_strip> which is an alias for
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C<NetPacket::Ethernet::strip>
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=item C<:ALL>
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All the above exportable items.
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=back
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=back
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=head1 EXAMPLE
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The following script dumps ethernet frames by mac address and protocol
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to standard output.
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#!/usr/bin/perl -w
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use strict;
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use Net::PcapUtils;
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use NetPacket::Ethernet;
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sub process_pkt {
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my($arg, $hdr, $pkt) = @_;
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my $eth_obj = NetPacket::Ethernet->decode($pkt);
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print("$eth_obj->{src_mac}:$eth_obj->{dest_mac} $eth_obj->{type}\n");
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}
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Net::PcapUtils::loop(\&process_pkt);
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=head1 TODO
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=over
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=item Implement C<encode()> function
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=back
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=head1 COPYRIGHT
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Copyright (c) 2001 Tim Potter.
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This package is free software and is provided "as is" without express
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or implied warranty. It may be used, redistributed and/or modified
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under the terms of the Perl Artistic License (see
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http://www.perl.com/perl/misc/Artistic.html)
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Copyright (c) 1995,1996,1997,1998,1999 ANU and CSIRO on behalf of
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the participants in the CRC for Advanced Computational Systems
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('ACSys').
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ACSys makes this software and all associated data and documentation
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('Software') available free of charge. You may make copies of the
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Software but you must include all of this notice on any copy.
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The Software was developed for research purposes and ACSys does not
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warrant that it is error free or fit for any purpose. ACSys
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disclaims any liability for all claims, expenses, losses, damages
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and costs any user may incur as a result of using, copying or
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modifying the Software.
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=head1 AUTHOR
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Tim Potter E<lt>tpot@samba.orgE<gt>
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=cut
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# any real autoloaded methods go after this line
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