#!/usr/bin/perl

use Net::RawIP qw(:pcap);

# create PCAP object
#
$in  = new Net::RawIP({ udp => {} });
$out = new Net::RawIP({ udp => {} });

# set capture parameters
#
$device = 'ne3';

$filt = 'ip proto UDP and src port not 2200 and  dst port 123';
$size = 65535;
$tout = 1;

$pcap = $in->pcapinit($device,$filt,$size,$tout);

loop $pcap,-1,\&callback,\@out;

# callback for every capture
#
sub callback{
	print "Captured ntp and re-transmit to port 2200...\n";
	$out->set({ip =>  {saddr => 'nimbus4.localnet',
		   	   daddr => '192.168.2.255'},
	   	   udp => {source => 2200,
		  	   dest => 123,
			   data => substr($_[2], 42, length($_[2]))}
		  });
	$out->send(10,1);
}