Block specific IP block from my website in PHP

Question

I'd like, for example, block every IP from base 89.95 (89.95..). I don't have .htaccess files on my server, so I'll have to do it with PHP.

if ($_SERVER['REMOTE_ADDR'] == "89.95.25.37") die();

Would block specific IP. How can I block entire IP blocks?

Answer 1

Try strpos()

if(strpos($_SERVER['REMOTE_ADDR'], "89.95") === 0)
{
    die();
}

If you notice, the === operator makes sure that the 89.95 is at the beginning of the IP address. This means that you can specify as much of the IP address as you want, and it will block no matter what numbers come after it.

For instance, all of these will be blocked:

89.95 -> 89.95.12.34, 89.95.1234.1, 89.95.1.1
89.95.6 -> 89.95.65.34, 89.95.61.1, 89.95.6987

(some of those aren't valid IP addresses though)

Answer 2

Use ip2long() to convert dotted decimal to a real IP address. Then you can do ranges easily.

Just do ip2long() on the high and low range to get the value, then use those as constants in your code.

If you're familiar with subnet masking, you can do it like this:

// Deny 10.12.*.*
$network = ip2long("10.12.0.0");
$mask = ip2long("255.255.0.0");
$ip = ip2long($_SERVER['REMOTE_ADDR']);
if (($network & $mask) == ($ip & $mask)) {
  die("Unauthorized");
}

Or if you're familiar with this format 10.12.0.0/16:

// Deny 10.12.*.*
$network = ip2long("10.12.0.0");
$prefix = 16;
$ip = ip2long($_SERVER['REMOTE_ADDR']);
if ($network >> (32 - $prefix)) == ($ip >> (32 - $prefix)) {
  die("Unauthorized");
}

You can turn these into functions and have very manageable code, making it easy to add IP addresses and customize the ranges.

Answer 3

Convert the dotted quad to an integer:

$ip = sprintf('%u', ip2long($_SERVER['REMOTE_ADDR']));

// only allow 10.0.0.0 – 10.255.255.255
if (!($ip >= 167772160 && $ip <=  184549375)) {
    die('Forbidden.');
}

Answer 4

$user_ip = $_SERVER['REMOTE_ADDR']; // get user ip

$denyIPs = array("111.111.111", "222.222.222", "333.333.333");
if (in_array ($user_ip, $denyIPs)) {
   // blocked ip
}
else {
   // not blocked
}

Answer 5

This has always worked very well for me: This checks for the proper server variables and compares it against a list of known IPs.. and yes, PHP does understand wildcards, so using * within the IP with assist in blocking ranges of IPs.

// The blacklisted ips.
$denied_ips = array(
'1.2.3.4',
'2.3.*',
);

// The function to get the visitor's IP.
function getUserIP(){
    //check ip from share internet
    if (!empty($_SERVER['HTTP_CLIENT_IP'])){
      $ip=$_SERVER['HTTP_CLIENT_IP'];
    }
    //to check ip is pass from proxy
    elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])){
      $ip=$_SERVER['HTTP_X_FORWARDED_FOR'];
    } else {
      $ip=$_SERVER['REMOTE_ADDR'];
    }
    return $ip;
}
//The user
$visitorIp = getUserIP();

// Now let's search if this IP is blackliated
$status = array_search($visitorIp, $denied_ips);

// Let's check if $status has a true OR false value.
if($status !== false){
    echo '<div class="error">Your IP has been banned! Stop spamming us!</div>';
    // header("Location: http://zombo.com");
    // exit; 
}

There's also a great article at Perishable Press: http://perishablepress.com/how-to-block-ip-addresses-with-php/

Answer 6

Make a substring :) For example for blocking 89.95.25.* you make a substring of the IP, cutting off the last two numbers and compare it to "89.95.25."

Answer 7

using revive's code, use this to get wildcard search working

// Now let's search if this IP is blackliated
$status = false;
foreach($denied_ips as $val)
{
    if (strpos($val,'*') !== false)
    {
        if(strpos($visitorIp, array_shift(explode("*", $val))) === 0)
        {
            $status = true;
            break;
        }
    }
    else
    {
        if(strcmp($visitorIp, $val) === 0)
        {
            $status = true;
            break;
        }
    }
}

Answer 8

$deny = array("111.111.111", "222.222.222", "333.333.333");

if (in_array($_SERVER['REMOTE_ADDR'], $deny)) {
    header("location:http://www.google.com/");
    exit();
}