获取真实的ip

    /**
     * 获取真实IP
     * @return mixed
     */
    public static function getRealIp()
    {
        $ip = $_SERVER['REMOTE_ADDR'];
        if (isset($_SERVER['HTTP_X_FORWARDED_FOR']) && preg_match_all('#\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}#s', $_SERVER['HTTP_X_FORWARDED_FOR'], $matches)) {
            foreach ($matches[0] AS $xip) {
                if (!preg_match('#^(10|172\.16|192\.168)\.#', $xip)) {
                    $ip = $xip;
                    break;
                }
            }
        } elseif (isset($_SERVER['HTTP_CLIENT_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CLIENT_IP'])) {
            $ip = $_SERVER['HTTP_CLIENT_IP'];
        } elseif (isset($_SERVER['HTTP_CF_CONNECTING_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_CF_CONNECTING_IP'])) {
            $ip = $_SERVER['HTTP_CF_CONNECTING_IP'];
        } elseif (isset($_SERVER['HTTP_X_REAL_IP']) && preg_match('/^([0-9]{1,3}\.){3}[0-9]{1,3}$/', $_SERVER['HTTP_X_REAL_IP'])) {
            $ip = $_SERVER['HTTP_X_REAL_IP'];
        }
        return $ip;
    }