This function checks for a valid IP address or CIDR notation address range.
<?php
/**
* @author phptuts
* @copyright 2012
* @link http://tutorialspots.com/
*/
function valid_ip_cidr($cidr, $must_cidr = false)
{
if (!preg_match("/^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}(\/[0-9]{1,2})?$/", $cidr))
{
$return = false;
} else
{
$return = true;
}
if ($return == true)
{
$parts = explode("/", $cidr);
$ip = $parts[0];
$netmask = $parts[1];
$octets = explode(".", $ip);
foreach ($octets as $octet)
{
if ($octet > 255)
{
$return = false;
}
}
if ((($netmask != "") && ($netmask > 32) && !$must_cidr) || (($netmask == ""||$netmask > 32) && $must_cidr))
{
$return = false;
}
}
return $return;
}
?>
Example of usage:
<?
var_dump(valid_ip_cidr('145.3.233.45')); //true
var_dump(valid_ip_cidr('345.3.233.45')); //false
var_dump(valid_ip_cidr('145.3.233.45/11')); //true
var_dump(valid_ip_cidr('345.3.233.45/11')); //false
var_dump(valid_ip_cidr('145.3.233.45',true)); //false
var_dump(valid_ip_cidr('145.3.233.45/41',true)); //false
?>
