#! /usr/bin/perl -s

use Net::RawSock;
use NetPacket::IP;
use NetPacket::TCP;
use Time::HiRes qw(usleep gettimeofday tv_interval);
use feature qw/say/;
use Benchmark;

if(!defined $n or !defined $secs )
        {
        print "Usage: ./packgen.pl  -n=<number of packets/sec> -secs=<number of seconds> \n";
        exit;
        } 

print "\nCreating Packets ....";
open (FILE, '/home/tahir/Downloads/packet_generator.txt');
chomp (@lines = (<FILE>));
close(FILE);

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

## Init IP
$ip_obj->{ver}        = 4; 
$ip_obj->{hlen}       = 5;
$ip_obj->{tos}        = 0;
$ip_obj->{id}         = 0x1d1d;
$ip_obj->{ttl}        = 0x5a;
$ip_obj->{flags}      = 2;
$ip_obj->{len}        = 84;

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

## Init TCP
$tcp_obj->{hlen}      = 5;
$tcp_obj->{winsize}   = 0x8e30;
$tcp_obj->{seqnum}    = 0xFFFF;
$tcp_obj->{acknum}    = 0xCCCC;
$tcp_obj->{flags}     = SYN;
$tcp_obj->{data}      =ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn;

## Assemble
$ip_obj->{proto}      = 6; 
$ip_obj->{data}       = $tcp_obj->encode($ip_obj);
						
			$num =0;
			for ($num = 0; $num<=@lines; $num++)
			{
			$line=$lines[$num];
			#for every line in the lines
			#build packet
			my($sip, $sport, $dip, $dport) = split(/\s+/, $line);			
			$ip_obj->{src_ip}     = $sip;
			$tcp_obj->{src_port}  = $sport;
			$ip_obj->{dest_ip}    = $dip;			
			$tcp_obj->{dest_port} = $dport;
			#print ": $sip\t";
			#print ": $sport\t";
			#print " : $dip\t";
			#print ": $dport\n";
					
			## Create RAW
			
			@packets[$num] = $ip_obj->encode;
			#say $lines[$j];
			#add packet to a vector of packets
			#end for
			#Now we have an array of packets
			}

#you want n pkt/sec for 10 seconds, so
#you want n/1000 pkt per 1/1000 sec 
  	$num=0;
	$count = 0;
	$pkts_per_ms = $n / 1000;
	$start = time(); #[Time::HiRes::gettimeofday];
	$dim= scalar(@lines); 
#	$TEST=$packets[0];
	while ( ((time()-$start)<($secs)) || ($count < ($n*$secs)))
	{
		$before = [Time::HiRes::gettimeofday];
		for ($i=$pkts_per_ms;$i>0;$i--)
		{
		 	$num=($num+1)% $dim ;
			#if now packets is the array of packets,you will send 
		 	Net::RawSock::write_ip($packets[$num]);
		#	Net::RawSock::write_ip($TEST);	
		}
		while (tv_interval($before)<0.001)
		{
			#print tv_interval($before), " ";
		}
		$count = $count + $pkts_per_ms;
	} 
	print "TIME: ", time()-$start, "\n";

	#print "You took ", tv_interval($start), " seconds for sending $count packets.\n";
	print "You took ", time() - $start, " seconds for sending $count packets.\n";