Gazelle/classes/proxies.class.php

<?php
//Useful: http://www.robtex.com/cnet/
$AllowedProxies = array(
  //Opera Turbo (may include Opera-owned IP addresses that aren't used for Turbo, but shouldn't run much risk of exploitation)
  '64.255.180.*', //Norway
  '64.255.164.*', //Norway
  '80.239.242.*', //Poland
  '80.239.243.*', //Poland
  '91.203.96.*', //Norway
  '94.246.126.*', //Norway
  '94.246.127.*', //Norway
  '195.189.142.*', //Norway
  '195.189.143.*', //Norway
);

function proxyCheck($IP)
{
    global $AllowedProxies;
    for ($i = 0, $il = count($AllowedProxies); $i < $il; ++$i) {
        //based on the wildcard principle it should never be shorter
        if (strlen($IP) < strlen($AllowedProxies[$i])) {
            continue;
        }

        //since we're matching bit for bit iterating from the start
        for ($j = 0, $jl = strlen($IP); $j < $jl; ++$j) {
            //completed iteration and no inequality
            if ($j == $jl - 1 && $IP[$j] === $AllowedProxies[$i][$j]) {
                return true;
            }

            //wildcard
            if ($AllowedProxies[$i][$j] === '*') {
                return true;
            }

            //inequality found
            if ($IP[$j] !== $AllowedProxies[$i][$j]) {
                break;
            }
        }
    }
    return false;
}