<?php
$timestampcc = time();
$cc_nowtime = $timestampcc;
if(session_is_registered('cc_lasttime')){
 $cc_lasttime = $_SESSION['cc_lasttime'];
 $cc_times = $_SESSION['cc_times']+1;
 $_SESSION['cc_times'] = $cc_times;
}else{
 $cc_lasttime = $cc_nowtime;
 $cc_times = 1;
 $_SESSION['cc_times'] = $cc_times;
 $_SESSION['cc_lasttime'] = $cc_lasttime;
} 
if(($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 '刷新太快!';
 exit;
 }
}else{
 $cc_times = 0;
 $_SESSION['cc_lasttime'] = $cc_nowtime;
 $_SESSION['cc_times'] = $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['k'];  
$t=$_GET['t'];  
$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;  
}  
?> 

<? 
session_start(); 
if(!emptyempty($_POST[name])){ 
 $data = $_POST[name]; 
 $tag = $_POST[tag]; 
 if($_SESSION[status]==$tag){ 
 echo $data; 
 }else{ 
 echo "不允许刷新！"; 
 } 
} 
$v = mt_rand(1,10000); 
?> 
<form method="post" name="magic" action="f5.php"><input type="hidden" 
name="tag" value="<?=$v?>"><input type=text name="name"><input type="submit" value="submit"> 
</form> 
<? 
echo $v; 
$_SESSION[status] = $v; 
?> 

<? 
session_start(); 
if(!emptyempty($_POST[name])){ 
 $data = $_POST[name]; 
 $tag = $_POST[tag]; 
 if($_SESSION[status]==$tag){ 
 echo $data; 
 }else{ 
 echo "不允许刷新！"; 
 } 
} 
$v = mt_rand(1,10000); 
?> 
<form method="post" name="magic" action="f5.php"><input type="hidden" 
name="tag" value="<?=$v?>"><input type=text name="name"><input type="submit" value="submit"> 
</form> 
<? 
echo $v; 
$_SESSION[status] = $v; 
?>