NetPacket::Ethernet(3p)

NAME
NetPacket::Ethernet - Assemble and disassemble ethernet packets.

VERSION
version 1.7.2

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 and Stephanie Wehner.

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

This module is free software. You can redistribute it and/or modify it under the terms of the Artistic License 2.0.

This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.

AUTHOR
Tim Potter <tpot@samba.org>