NAME¶
NetPacket::ICMP - Assemble and disassemble ICMP (Internet Control Message
Protocol) packets.
VERSION¶
version 1.3.0
SYNOPSIS¶
use NetPacket::ICMP;
$icmp_obj = NetPacket::ICMP->decode($raw_pkt);
$icmp_pkt = NetPacket::ICMP->encode();
$icmp_data = NetPacket::ICMP::strip($raw_pkt);
DESCRIPTION¶
"NetPacket::ICMP" provides a set of routines for assembling and
disassembling packets using ICMP (Internet Control Message Protocol).
Methods¶
- "NetPacket::ICMP->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::ICMP->encode()"
- Return an ICMP packet encoded with the instance data
specified.
Functions¶
- "NetPacket::ICMP::strip([RAW PACKET])"
- Return the encapsulated data (or payload) contained in the
ICMP packet.
Instance data¶
The instance data for the "NetPacket::ICMP" object consists of the
following fields.
- type
- The ICMP message type of this packet.
- code
- The ICMP message code of this packet.
- cksum
- The checksum for this packet.
- data
- The encapsulated data (payload) for this packet.
Exports¶
- default
- none
- exportable
- ICMP message types:
ICMP_ECHOREPLY ICMP_UNREACH ICMP_SOURCEQUENCH
ICMP_REDIRECT ICMP_ECHO ICMP_ROUTERADVERT
ICMP_ROUTERSOLICIT ICMP_TIMXCEED ICMP_PARAMPROB
ICMP_TSTAMP ICMP_TSTAMPREPLY ICMP_IREQ ICMP_IREQREPLY
ICMP_MASKREQ ICMP_MASKREPLY
- tags
- The following tags group together related exportable
items.
- ":types"
-
ICMP_ECHOREPLY ICMP_UNREACH ICMP_SOURCEQUENCH
ICMP_REDIRECT ICMP_ECHO ICMP_ROUTERADVERT
ICMP_ROUTERSOLICIT ICMP_TIMXCEED ICMP_PARAMPROB
ICMP_TSTAMP ICMP_TSTAMPREPLY ICMP_IREQ
ICMP_IREQREPLY ICMP_MASKREQ ICMP_MASKREPLY
- ":strip"
- Import the strip function "icmp_strip".
- ":ALL"
- All the above exportable items.
EXAMPLE¶
The following example prints the ICMP type, code, and checksum fields.
#!/usr/bin/perl -w
use strict;
use Net::PcapUtils;
use NetPacket::Ethernet qw(:strip);
use NetPacket::IP qw(:strip);
use NetPacket::ICMP;
sub process_pkt {
my ($user, $hdr, $pkt) = @_;
my $ip_obj = NetPacket::IP->decode(eth_strip($pkt));
my $icmp_obj = NetPacket::ICMP->decode(ip_strip($ip_obj));
print("Type: $icmp_obj->{type}\n");
print("Code: $icmp_obj->{code}\n");
print("Checksum: $icmp_obj->{cksum}\n\n");
}
Net::PcapUtils::loop(\&process_pkt, FILTER => 'icmp');
TODO¶
- Create constants
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>
Stephanie Wehner <atrak@itsx.com>