NAME

NetPacket::Ethernet - Assemble and disassemble ethernet packets.

SYNOPSIS

  use NetPacket::Ethernet;

  $eth_obj = NetPacket::Ethernet->decode($raw_pkt);
  $eth_pkt = NetPacket::Ethernet->encode(params...);   # Not implemented
  $eth_data = NetPacket::Ethernet::strip($raw_pkt);

DESCRIPTION

NetPacket::Ethernet provides a set of routines for assembling and disassembling packets using the Ethernet protocol.

Methods

NetPacket::Ethernet->decode([RAW PACKET])

Decode the raw packet data given and return an object containing instance data. This method will quite happily decode garbage input. It is the responsibility of the programmer to ensure valid packet data is passed to this method.

NetPacket::Ethernet->encode(param => value)

Return an ethernet packet encoded with the instance data specified. Not implemented.

Functions

NetPacket::Ethernet::strip([RAW PACKET])

Return the encapsulated data (or payload) contained in the ethernet packet. This data is suitable to be used as input for other NetPacket::* modules.

This function is equivalent to creating an object using the decode() constructor and returning the data field of that object.

Instance data

The instance data for the NetPacket::Ethernet object consists of the following fields.

src_mac

The source MAC address for the ethernet packet as a hex string.

dest_mac

The destination MAC address for the ethernet packet as a hex string.

type

The protocol type for the ethernet packet.

data

The payload for the ethernet packet.

Exports

default

none

exportable

ETH_TYPE_IP ETH_TYPE_ARP ETH_TYPE_APPLETALK ETH_TYPE_SNMP ETH_TYPE_IPv6 ETH_TYPE_PPP

tags

The following tags group together related exportable items.

:types

ETH_TYPE_IP ETH_TYPE_ARP ETH_TYPE_APPLETALK ETH_TYPE_SNMP ETH_TYPE_IPv6 ETH_TYPE_PPP

:strip

Import the strip function eth_strip which is an alias for NetPacket::Ethernet::strip

:ALL

All the above exportable items.

EXAMPLE

The following script dumps ethernet frames by mac address and protocol to standard output.

  #!/usr/bin/perl -w

  use strict;
  use Net::PcapUtils;
  use NetPacket::Ethernet;

  sub process_pkt {
      my($arg, $hdr, $pkt) = @_;

      my $eth_obj = NetPacket::Ethernet->decode($pkt);
      print("$eth_obj->{src_mac}:$eth_obj->{dest_mac} $eth_obj->{type}\n");
  }

  Net::PcapUtils::loop(\&process_pkt);

TODO

Implement encode() function

COPYRIGHT

  Copyright (c) 2001 Tim Potter.

  This package is free software and is provided "as is" without express 
  or implied warranty.  It may be used, redistributed and/or modified 
  under the terms of the Perl Artistic License (see
  http://www.perl.com/perl/misc/Artistic.html)

  Copyright (c) 1995,1996,1997,1998,1999 ANU and CSIRO on behalf of 
  the participants in the CRC for Advanced Computational Systems
  ('ACSys').

  ACSys makes this software and all associated data and documentation
  ('Software') available free of charge.  You may make copies of the 
  Software but you must include all of this notice on any copy.

  The Software was developed for research purposes and ACSys does not
  warrant that it is error free or fit for any purpose.  ACSys
  disclaims any liability for all claims, expenses, losses, damages
  and costs any user may incur as a result of using, copying or
  modifying the Software.

AUTHOR

Tim Potter <tpot@samba.org>