NAME

       NetPacket::ARP - Assemble and disassemble ARP (Address Resolution Protocol) packets.

VERSION

       version 1.6.0

SYNOPSIS

         use NetPacket::ARP;

         $tcp_obj = NetPacket::ARP->decode($raw_pkt);
         $tcp_pkt = NetPacket::ARP->encode(params...);   # Not implemented

DESCRIPTION

       "NetPacket::ARP" provides a set of routines for assembling and disassembling packets using
       ARP (Address Resolution Protocol).

   Methods
       "NetPacket::ARP->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::ARP->encode(param => value)"
           Return a ARP packet encoded with the instance data specified.  Not implemented.

   Functions
       "NetPacket::ARP::strip([RAW PACKET])"
           Return the encapsulated data (or payload) contained in the TCP packet.  Since no
           payload data is encapulated in an ARP packet (only instance data), this function
           returns undef.

   Instance data
       The instance data for the "NetPacket::ARP" object consists of the following fields.

       htype
           Hardware type.

       proto
           Protocol type.

       hlen
           Header length.

       plen
           Protocol length.

       opcode
           One of the following constants:

           •   ARP_OPCODE_REQUEST

           •   ARP_OPCODE_REPLY

           •   RARP_OPCODE_REQUEST

           •   RARP_OPCODE_REPLY

       sha Source hardware address.

       spa Source protocol address.

       tha Target hardware address.

       tpa Target protocol address.

   Exports
       default
           none

       exportable
           none

       tags
           The following tags group together related exportable items.

           ":ALL"
               All the above exportable items.

EXAMPLE

       Print out arp requests on the local network.

         #!/usr/bin/perl -w

         use Net::PcapUtils;
         use NetPacket::Ethernet qw(:types);
         use NetPacket::ARP;

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

           my $eth_obj = NetPacket::Ethernet->decode($pkt);

           if ($eth_obj->{type} == ETH_TYPE_ARP) {
               my $arp_obj = NetPacket::ARP->decode($eth_obj->{data}, $eth_obj);
               print("source hw addr=$arp_obj->{sha}, " .
                     "dest hw addr=$arp_obj->{tha}\n");
           }
         }

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

TODO

       Implement encode() function
       Does this work for protocols other than IP?  Need to read RFC.
       Example is a bit silly

COPYRIGHT

       Copyright (c) 2001 Tim Potter.

       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>