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Net::Frame::Layer::IPv4(3pm) User Contributed Perl Documentation Net::Frame::Layer::IPv4(3pm)

NAME

Net::Frame::Layer::IPv4 - Internet Protocol v4 layer object

SYNOPSIS

   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;

DESCRIPTION

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

IP ID of the datagram.
Time to live.
Source and destination IP addresses.
Of which type the layer 4 is.
IP checksum.
IP Flags.
IP fragment offset.
IP version, here it is 4.
Type of service flag.
Total length in bytes of the packet, including IP headers (that is, layer 3 + layer 4 + layer 7).
Header length in number of words, including IP options.
IP options, as a hexadecimal string.
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.

METHODS

Object constructor. You can pass attributes that will overwrite default ones. See SYNOPSIS for default values.
Returns the header length in bytes, not including IP options.
Returns the length in bytes of IP options. 0 if none.
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).
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.

CONSTANTS

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

Various protocol type constants.
Various possible flags.

SEE ALSO

Net::Frame::Layer

AUTHOR

Patrice <GomoR> Auffret

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.

2022-12-04 perl v5.36.0