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

Net::Frame::Layer::TCP - Transmission Control Protocol layer object

   use Net::Frame::Layer::TCP qw(:consts);
   # Build a layer
   my $layer = Net::Frame::Layer::TCP->new(
      src      => getRandomHighPort(),
      dst      => 0,
      seq      => getRandom32bitsInt(),
      ack      => 0,
      x2       => 0,
      off      => 0,
      flags    => NF_TCP_FLAGS_SYN,
      win      => 0xffff,
      checksum => 0,
      urp      => 0,
      options  => '',
   );
   $layer->pack;
   print 'RAW: '.$layer->dump."\n";
   # Read a raw layer
   my $layer = Net::Frame::Layer::TCP->new(raw => $raw);
   print $layer->print."\n";
   print 'PAYLOAD: '.unpack('H*', $layer->payload)."\n"
      if $layer->payload;

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

RFC: ftp://ftp.rfc-editor.org/in-notes/rfc793.txt

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

Source and destination ports.
TCP flags, see CONSTANTS.
The window size.
Sequence and acknowledgment numbers.
The size in number of words of the TCP header.
Reserved field.
The TCP header checksum.
Urgent pointer.
TCP options, as a hexadecimal string.

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

Object constructor. You can pass attributes that will overwrite default ones. See SYNOPSIS for default values.
Returns the header length in bytes, not including TCP options.
Returns options length in bytes.
Computes various lengths contained within this layer.
In order to compute checksums of TCP, you need to pass the protocol type (IPv4, IPv6), the source and destination IP addresses (IPv4 for IPv4, IPv6 for IPv6).
These two methods are basically used to increase the speed when using recv method from Net::Frame::Simple. Usually, you write them when you need to write match method.
This method is mostly used internally. You pass a Net::Frame::Layer::TCP layer as a parameter, and it returns true if this is a response corresponding for the request, or returns false if not.

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.

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

TCP flags constants.

Net::Frame::Layer

Patrice <GomoR> Auffret

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