PHP防CC攻击代码

PHP防CC攻击代码：

empty($_SERVER['HTTP_VIA']) or exit('Access Denied');  //代理IP直接退出

session_start();
$seconds = '2'; //时间间隔
$refresh = '3'; //防止快速刷新  刷新次数 设置监控变量
$cur_time = time();

if( isset($_SESSION['last_time']) ){
    $_SESSION['refresh_times'] += 1;
}
else{
    $_SESSION['refresh_times'] = 1;
    $_SESSION['last_time'] = $cur_time;
}

//处理监控结果
if( $cur_time - $_SESSION['last_time'] < $seconds ){
    if( $_SESSION['refresh_times'] >= $refresh ){
        //跳转至攻击者服务器地址
        header(sprintf('Location:%s', 'http://127.0.0.1'));
        exit('Access Denied');
    }
}
else{
    $_SESSION['refresh_times'] = 0;
    $_SESSION['last_time'] = $cur_time;
}