NetPacket - modules to assemble/disassemble network packets at the protocol level.
# NetPacket is a base class only
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.
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
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
encode(), decode(), strip()
Every NetPacket:: object should have the following fields.
A link to the parent
NetPacket:: object in which this
NetPacket:: object is encaulated. This field is undefined if there is no parent object.
A copy of the raw data of the packet.
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.
Copyright (c) 2001 Tim Potter. This package is free software and is provided "as is" without express or implied warranty. It may be used, redistributed and/or modified under the terms of the Perl Artistic License (see http://www.perl.com/perl/misc/Artistic.html) Copyright (c) 1995,1996,1997,1998,1999 ANU and CSIRO on behalf of the participants in the CRC for Advanced Computational Systems ('ACSys'). ACSys makes this software and all associated data and documentation ('Software') available free of charge. You may make copies of the Software but you must include all of this notice on any copy. The Software was developed for research purposes and ACSys does not warrant that it is error free or fit for any purpose. ACSys disclaims any liability for all claims, expenses, losses, damages and costs any user may incur as a result of using, copying or modifying the Software.
Tim Potter <firstname.lastname@example.org>
Stephanie Wehner <email@example.com>