获取真实ip

 public function ip()
    {
        if (getenv('HTTP_CLIENT_IP')) {
            $ip = getenv('HTTP_CLIENT_IP');
        }
        elseif (getenv('HTTP_X_FORWARDED_FOR')) {
            $ip = getenv('HTTP_X_FORWARDED_FOR');
        }
        elseif (getenv('HTTP_X_FORWARDED')) {
            $ip = getenv('HTTP_X_FORWARDED');
        }
        elseif (getenv('HTTP_FORWARDED_FOR')) {
            $ip = getenv('HTTP_FORWARDED_FOR');

        }
        elseif (getenv('HTTP_FORWARDED')) {
            $ip = getenv('HTTP_FORWARDED');
        }
        else {
            $ip = $_SERVER['REMOTE_ADDR'];
        }
        return explode(',',$ip);
    }

 $arr = array('43.241.10.171','113.87.131.156','122.228.238.72');
        if(in_array($ip,$arr)){
            exit('服务器维护..');
        }