Net::RawSock - Perl module to send network raw IP datagrams

Stephane Aubert aka Kotao <Stephane.Aubert@hsc-labs.com>
HSC security research labs
Hervé Schauer Consultants

Copyright (c) 2001 Stephane Aubert. All rights reserved. This program is 
free software; you can redistribute it and/or modify it under the same 
terms as Perl itself.

Description
===========

Net::RawSock provides a base function to send raw IP datagrams 
from Perl. The raw IP datagam is packed into a buffer and written 
on the network layer with the write_ip() function.

Download
========

Main site: <URL: http://www.hsc.fr/tools/>


Howto install
-------------

% perl Makefile.PL
% make
# make install

Howto test
----------

# ./demo.pl

You should see :

xor [root] ~# tcpdump -lnx -s 1500 -i lo 
tcpdump: listening on lo
21:22:39.800446 127.0.0.1.33842 > 127.0.0.1.80: S 2877615549:2877615549(0)
win 32767 <mss 16396,sackOK,timestamp 10035571 0,nop,wscale 0> (DF) [tos 0x10] 
                         4510 003c ccce 4000 4006 6fdb 7f00 0001
                         7f00 0001 8432 0050 ab84 edbd 0000 0000
                         a002 7fff 4fdc 0000 0204 400c 0402 080a
                         0099 2173 0000 0000 0103 0300


Howto use
---------

#! /usr/bin/perl

use Net::RawSock;

## $pkt comes from: tcpdump -lnx -s 1500 -i lo
my $pkt =    
  "\x45\x10\x00\x3c\xcc\xce\x40\x00\x40\x06\x6f\xdb\x7f\x00\x00\x01".
  "\x7f\x00\x00\x01\x84\x32\x00\x50\xab\x84\xed\xbd\x00\x00\x00\x00".
  "\xa0\x02\x7f\xff\x4f\xdc\x00\x00\x02\x04\x40\x0c\x04\x02\x08\x0a".
  "\x00\x99\x21\x73\x00\x00\x00\x00\x01\x03\x03\x00";

Net::RawSock::write_ip($pkt);


Extended use:
-------------

You will need a very nice package, called NetPacket, by Tim Potter
<URL: http://www.cpan.org/modules/by-module/NetPacket/>

Sample code to create and send a TCP/IP raw datagram from scratch :

#! /usr/bin/perl
use Net::RawSock;
use NetPacket::IP;
use NetPacket::TCP;

## Create IP
my $ip = NetPacket::IP->decode(''); 

## Init IP
$ip->{ver}        = 4; 
$ip->{hlen}       = 5;
$ip->{tos}        = 0;
$ip->{id}         = 0x1d1d;
$ip->{ttl}        = 0x5a;
$ip->{src_ip}     = '127.0.0.1';
$ip->{dest_ip}    = '127.0.0.1';
$ip->{flags}      = 2;

## Create TCP
my $tcp = NetPacket::TCP->decode('');

## Init TCP
$tcp->{hlen}      = 5;
$tcp->{winsize}   = 0x8e30;
$tcp->{src_port}  = 13579;
$tcp->{dest_port} = 80;
$tcp->{seqnum}    = 0xFEED;
$tcp->{acknum}    = 0xC0DE;
$tcp->{flags}     = SYN | FIN;

## Assemble
$ip->{proto}      = 6; 
$ip->{data}       = $tcp->encode($ip);

## Create RAW
my $pkt = $ip->encode;

## Write to network layer
Net::RawSock::write_ip($pkt);