Get Client IP

Getting the Client IP Address from behind Cloudflare

<?php

function get_client_ip() {
		switch ( true ) {
			case ( isset( $_SERVER['HTTP_CF_CONNECTING_IP'] ) ):
				$ip = $_SERVER['HTTP_CF_CONNECTING_IP'];
				break;

			case ( isset( $_SERVER['HTTP_INCAP_CLIENT_IP'] ) ):
				$ip = $_SERVER['HTTP_INCAP_CLIENT_IP'];
				break;

			case ( isset( $_SERVER['True-Client-IP'] ) ):
				$ip = $_SERVER['True-Client-IP'];
				break;

			case ( isset( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ):
				$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
				break;

			case ( isset( $_SERVER['HTTP_X_REAL_IP'] ) ):
				$ip = $_SERVER['HTTP_X_REAL_IP'];
				break;

			case ( isset( $_SERVER['X-Forwarded-For'] ) ):
				$ip = $_SERVER['X-Forwarded-For'];
				break;

			default:
				$cur = $_SERVER['REMOTE_ADDR'];
				$list = explode( ',', $cur );
				$real = filter_var( $list[0], FILTER_VALIDATE_IP );
				$parts = explode( '.', $real );
				if ( '10' == $parts[0] || '192' == $parts[0] || '127' == $parts[0] ) {
					$ip = '81.157.49.99';
				} else {
					$ip = $real;
				}
				break;
		}
		return $ip;
	}