NetPacket::ARP(3) User Contributed Perl Documentation NetPacket::ARP(3)NAMENetPacket::ARP - Assemble and disassemble ARP (Address Resolution
Protocol) packets.
VERSION
version 1.3.0
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>
perl v5.14.2 2011-11-14 NetPacket::ARP(3)