Net::Frame::Layer::IPv43pm

Usage

   use Net::Frame::Layer::IPv4 qw(:consts);
   # Build a layer
   my $layer = Net::Frame::Layer::IPv4->new(
      version  => 4,
      tos      => 0,
      id       => getRandom16bitsInt(),
      length   => NF_IPv4_HDR_LEN,
      hlen     => 5,
      flags    => 0,
      offset   => 0,
      ttl      => 128,
      protocol => NF_IPv4_PROTOCOL_TCP,
      checksum => 0,
      src      => '127.0.0.1',
      dst      => '127.0.0.1',
      options  => '',
      noFixLen => 0,
   );
   $layer->pack;
   print 'RAW: '.$layer->dump."\n";
   # Read a raw layer
   my $layer = Net::Frame::Layer::IPv4->new(raw => $raw);
   print $layer->print."\n";
   print 'PAYLOAD: '.unpack('H*', $layer->payload)."\n"
      if $layer->payload;

Overview

This modules implements the encoding and decoding of the IPv4 layer.

RFC: ftp://ftp.rfc-editor.org/in-notes/rfc791.txt

See also Net::Frame::Layer for other attributes and methods.

Attributes

id

IP ID of the datagram.

ttl

Time to live.

src

dst

Source and destination IP addresses.

protocol

Of which type the layer 4 is.

checksum

IP checksum.

flags

IP Flags.

offset

IP fragment offset.

version

IP version, here it is 4.

tos

Type of service flag.

length

Total length in bytes of the packet, including IP headers (that is, layer 3 + layer 4 + layer 7).

hlen

Header length in number of words, including IP options.

options

IP options, as a hexadecimal string.

noFixLen

Since the byte ordering of length attribute varies from system to system, a subroutine inside this module detects which byte order to use. Sometimes, like when you build Net::Frame::Layer::8021Q layers, you may have the need to avoid this. So set it to 1 in order to avoid fixing. Default is 0 (that is to fix).

The following are inherited attributes. See Net::Frame::Layer for more information.

raw

payload

nextLayer

Methods

new

new (hash)

Object constructor. You can pass attributes that will overwrite default ones. See SYNOPSIS for default values.

getHeaderLength

Returns the header length in bytes, not including IP options.

getOptionsLength

Returns the length in bytes of IP options. 0 if none.

computeLengths ({ payloadLength => VALUE })

In order to compute lengths attributes within IPv4 header, you need to pass via a hashref the number of bytes contained in IPv4 payload (that is, the sum of all layers after the IPv4 one).

computeChecksums

Computes the IPv4 checksum.

The following are inherited methods. Some of them may be overridden in this layer, and some others may not be meaningful in this layer. See Net::Frame::Layer for more information.

layer

computeLengths

computeChecksums

pack

unpack

encapsulate

getLength

getPayloadLength

print

dump

Constants

Load them: use Net::Frame::Layer::IPv4 qw(:consts);

NF_IPv4_PROTOCOL_ICMPv4

NF_IPv4_PROTOCOL_IGMP

NF_IPv4_PROTOCOL_IPIP

NF_IPv4_PROTOCOL_TCP

NF_IPv4_PROTOCOL_EGP

NF_IPv4_PROTOCOL_IGRP

NF_IPv4_PROTOCOL_CHAOS

NF_IPv4_PROTOCOL_UDP

NF_IPv4_PROTOCOL_IDP

NF_IPv4_PROTOCOL_DCCP

NF_IPv4_PROTOCOL_IPv6

NF_IPv4_PROTOCOL_IPv6ROUTING

NF_IPv4_PROTOCOL_IPv6FRAGMENT

NF_IPv4_PROTOCOL_IDRP

NF_IPv4_PROTOCOL_RSVP

NF_IPv4_PROTOCOL_GRE

NF_IPv4_PROTOCOL_ESP

NF_IPv4_PROTOCOL_AH

NF_IPv4_PROTOCOL_ICMPv6

NF_IPv4_PROTOCOL_EIGRP

NF_IPv4_PROTOCOL_OSPF

NF_IPv4_PROTOCOL_ETHERIP

NF_IPv4_PROTOCOL_PIM

NF_IPv4_PROTOCOL_VRRP

NF_IPv4_PROTOCOL_STP

NF_IPv4_PROTOCOL_SCTP

NF_IPv4_PROTOCOL_UDPLITE

Various protocol type constants.

NF_IPv4_MORE_FRAGMENT

NF_IPv4_DONT_FRAGMENT

NF_IPv4_RESERVED_FRAGMENT

Various possible flags.

Copyright and license

Copyright (c) 2006-2019, Patrice <GomoR> Auffret

You may distribute this module under the terms of the Artistic license. See LICENSE.Artistic file in the source distribution archive.