netpacket(3pm) [debian man page]
NetPacket(3pm) User Contributed Perl Documentation NetPacket(3pm) NAME
NetPacket - assemble/disassemble network packets at the protocol level VERSION
version 1.3.0 SYNOPSIS
# NetPacket is a base class only DESCRIPTION
"NetPacket" provides a base class for a cluster of modules related to decoding and encoding of network protocols. Each "NetPacket" descendent module knows how to encode and decode packets for the network protocol it implements. Consult the documentation for the module in question for protocol-specific implementation. Note that there is no inheritance in the "NetPacket::" cluster of modules other than each protocol module being a "NetPacket". This was seen to be too restrictive as imposing inheritance relationships (for example between the IP, UDP and TCP protocols) would make things like tunneling or other unusual situations difficult. WRITING YOUR OWN ";NetPacket::" MODULE You are encouraged to write additional "NetPacket::" modules as well as improve existing ones. Contact the maintainer of the module in question with your suggestions or changes. The following sections are a list of suggestions and conventions for writing a "NetPacket::" module. Naming Conventions When creating a module in the "NetPacket::" namespace, it is suggested that you stick to a couple of conventions when naming packet contents. This will hopefully lead to a consistent namespace making the "NetPacket::" easier to use. Content names are all lowercase, with underscores separating multiple words. The following abbreviations are recommended: Word Abbreviation -------------------------------- source src destination dest checksum cksum identifier id version ver protocol proto Required Methods encode(), decode(), strip() Required Fields Every NetPacket:: object should have the following fields. _parent A link to the parent "NetPacket::" object in which this "NetPacket::" object is encaulated. This field is undefined if there is no parent object. _frame A copy of the raw data of the packet. data This field should contain the data encapsulated in the packet (i.e any headers or trailers stripped off) or undef if the packet contains no data. Note that in this sense, "data" is taken to mean information not relevant to the particular protocol being decoded. For example, an ARP packet contains many header fields but no data. A UDP datagram, however contains header fields and a payload. SEE ALSO
Joel Knight has a patch for NetPacket for IPv6 support available at http://www.packetmischief.ca/code/netpacket/. COPYRIGHT AND LICENSE
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. AUTHORS
Tim Potter <tpot@samba.org> Stephanie Wehner <atrak@itsx.com> Yanick Champoux <yanick@cpan.org> perl v5.14.2 2011-11-20 NetPacket(3pm)
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NetPacket::IGMP(3pm) User Contributed Perl Documentation NetPacket::IGMP(3pm) NAME
NetPacket::IGMP - Assemble and disassemble IGMP (Internet Group Mangement Protocol) packets. VERSION
version 1.3.0 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} "); } Net::PcapUtils::loop(&process_pkt, FILTER => 'igmp'); TODO
Implement encode() function 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 2011-11-20 NetPacket::IGMP(3pm)