NAME

NetPacket::IGMP - Assemble and disassemble IGMP (Internet Group Mangement Protocol) packets.

VERSION

version 1.6.0

SYNOPSIS

  use NetPacket::IGMP;

  $igmp_obj = NetPacket::IGMP->decode($raw_pkt);
  $igmp_pkt = NetPacket::IGMP->encode(params...);   # Not implemented
  $igmp_data = NetPacket::IGMP::strip($raw_pkt);

DESCRIPTION

"NetPacket::IGMP" provides a set of routines for assembling and disassembling packets using IGMP (Internet Group Mangement Protocol).

Methods

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

Functions

"NetPacket::IGMP::strip([RAW PACKET])": Return the encapsulated data (or payload) contained in the IGMP packet. This function returns undef as there is no encapsulated data in an IGMP packet.

Instance data

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

version: The IGMP version of this packet.
type: The message type for this packet.
len: The length (including length of header) in bytes for this packet.
subtype: The message subtype for this packet.
cksum: The checksum for this packet.
group_addr: The group address specified in this packet.
data: The encapsulated data (payload) for this packet.

Exports

default: none
exportable: IGMP_VERSION_RFC998 IGMP_VERSION_RFC1112 IGMP_HOST_MQUERY IGMP_HOST_MREPORT IGMP_IP_NO_HOSTS IGMP_IP_ALL_HOSTS IGMP_IP_ALL_ROUTERS
tags: The following tags group together related exportable items.

":strip": Import the strip function "igmp_strip".
":versions": IGMP_VERSION_RFC998 IGMP_VERSION_RFC1112
":msgtypes": IGMP_HOST_MQUERY IGMP_HOST_MREPORT
":group_addrs": IGMP_IP_NO_HOSTS IGMP_IP_ALL_HOSTS IGMP_IP_ALL_ROUTERS
":ALL": All the above exportable items.

EXAMPLE

The following script dumps UDP frames by IP address and UDP port to standard output.

  #!/usr/bin/perl -w

  use strict;
  use Net::PcapUtils;
  use NetPacket::Ethernet qw(:strip);
  use NetPacket::IP;
  use NetPacket::IGMP;

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

      my $ip_obj = NetPacket::IP->decode(eth_strip($pkt));
      my $igmp_obj = NetPacket::IGMP->decode($ip_obj->{data});

      print("$ip_obj->{src_ip} -> $ip_obj->{dest_ip} ",
            "$igmp_obj->{type}/$igmp_obj->{subtype} ",
            "$igmp_obj->{group_addr}\n");
  }

  Net::PcapUtils::loop(\&process_pkt, FILTER => 'igmp');

TODO

Implement encode() function

COPYRIGHT

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>