php防止CC攻击代码 php防止网页频繁刷新

<?php
$timestampcc = time();
$cc_nowtime = $timestampcc;
if(session_is_registered(&#39;cc_lasttime&#39;)){
 $cc_lasttime = $_SESSION[&#39;cc_lasttime&#39;];
 $cc_times = $_SESSION[&#39;cc_times&#39;]+1;
 $_SESSION[&#39;cc_times&#39;] = $cc_times;
}else{
 $cc_lasttime = $cc_nowtime;
 $cc_times = 1;
 $_SESSION[&#39;cc_times&#39;] = $cc_times;
 $_SESSION[&#39;cc_lasttime&#39;] = $cc_lasttime;
} 
if(($cc_nowtime-$cc_lasttime)<3){//3秒内刷新5次以上可能为cc攻击
 if($cc_times>=5){
 echo &#39;刷新太快!&#39;;
 exit;
 }
}else{
 $cc_times = 0;
 $_SESSION[&#39;cc_lasttime&#39;] = $cc_nowtime;
 $_SESSION[&#39;cc_times&#39;] = $cc_times;
} 
?>

<?php 
error_reporting(0); 
//if($_COOKIE["ck"])die("刷新过快！"); 
if($_COOKIE["ck"])header("Location:http://www.baidu.com");//这里如果用户刷新过快，给予终止php脚本或者直接302跳转 
setcookie("ck","1",time()+3);//设定cookie存活时间3s 
echo "hello!"; 
?>

<?php  
session_start();  
$k=$_GET[&#39;k&#39;];  
$t=$_GET[&#39;t&#39;];  
$allowTime = 1800;//防刷新时间  
$ip = get_client_ip();  
$allowT = md5($ip.$k.$t);  
if(!isset($_SESSION[$allowT]))  
{  
 $refresh = true;  
 $_SESSION[$allowT] = time();  
}elseif(time() - $_SESSION[$allowT]>$allowTime){  
 $refresh = true;  
 $_SESSION[$allowT] = time();  
}else{  
 $refresh = false;  
}  
?>