codeigniter / cloudflare

gistfile1.txt

class MY_Input extends CI_Input 
{
	function ip_address()
	{
		$ip = parent::ip_address();
		$proxy = $this->get_request_header('X-Forwarded-For');

		if($proxy) // check if there is a proxy being used
		{
			$iplong = ip2long($ip);

			// list of IP => mask
			/// http://www.cloudflare.com/wiki/What_are_the_CloudFlare_IP_address_ranges
			$whitelist = array(
				'204.93.240.0' => 24, 
				'204.93.177.0' => 24, 
				'199.27.128.0' => 21, 
				'173.245.48.0' => 20, 
				'103.22.200.0' => 22, 
				'141.101.64.0' => 18
			);

			foreach($whitelist as $whiteip => $mask)
			{
				$bitmask = bindec(str_repeat('1', $mask) . str_repeat('0', 32 - $mask));
				$trusted = ip2long($whiteip);

				if(($iplong & $bitmask) == $trusted)
				{
					$ip = $proxy;
					break; 
				}
			}
		}
		return $ip;
	}
}