php - deny access ip

function checkIp() {

    /**
     * Deny if not from the following IPs
     * 
     */
    if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
        $ip = $_SERVER['HTTP_CLIENT_IP'];
    } elseif (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
        $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
    } else {
        $ip = $_SERVER['REMOTE_ADDR'];
    }

    $validIps = array(
        '89.249.211.162',
        '89.249.211.163',
        '77.42.245.162',
        '89.249.211.164'
    );
//$validIps = array();

    if (!in_array($ip, $validIps)) {
//    http_response_code(401);
        header('HTTP/1.1 401 Unauthorized', true, 401);
        die('Unauthorized');
    }
}