PHP-IP Block - Printable Version

Code:
<?php

    /*
       Parameters of function:
       1: $aip      = Beginning of the ip area is '123.0.0.0'
       2: $bip      = End of the ip area is '123.255.255.255' or empty
                      (if the case of individual ip, empty)
       3: $xip      = compared ip is form of '123.1.2.3 or empty
                      (if nothing else if given, clarify the ip of visitor)
       4: $required = is ip address compulsory, true or false 
                      (in the case it's not clarified)

	   Function returns value TRUE if ip address is compulsory and it is cleared
	   and it doesn't match with given comparison address or it isn't in the given address range
    */

    function blockIps($aip=false,$bip=false,$xip=false,$required=true) {
		
		// Determine the compared ip address, if it's not given

        if (!$xip) {

            if (getenv("HTTP_CLIENT_IP")) {
                $xip = getenv("HTTP_CLIENT_IP");
            }

            elseif (getenv("HTTP_X_FORWARDED_FOR")) {
                $xip = getenv("HTTP_X_FORWARDED_FOR");
            }

            elseif (getenv("REMOTE_ADDR")) {
                $xip = getenv("REMOTE_ADDR");
            }

            else {
                $xip = false;
            }
            

        }
		
		// Address was not discovered, but it's not required = no

        if ($required && !$xip) {
            return false;
        }
		
		// Addres was not discovered, but it is not required = ok

        elseif (!$required && !$xip) {
            return true;
        }
		
		// IP address determined and the point of reference is an individual address

        if ($xip && $aip && !$bip) {
            $xip = sprintf('%u', ip2long($xip));
            $aip = sprintf('%u', ip2long($aip));
			
			// Given addresses don't match = ok
            if ($xip!=$aip) {
                return true;
            }
        }
		
		// Ip address determined and the point of reference is a certain ip address area

        elseif ($xip && $aip && $bip) {
            $xip = sprintf('%u', ip2long($xip));
            $aip = sprintf('%u', ip2long($aip));
            $bip = sprintf('%u', ip2long($bip));
			
			// Address is not in the field = ok

            if ($xip<$aip || $xip>$bip) {
                return true;
            }

        }
		
		// Default = no

        return false;

    }

?>