Example of php implementing cc attack defense and preventing quick page refreshes

<?php
// The agent IP Directly out of 
empty($_SERVER['HTTP_VIA']) or exit('Access Denied');
// Prevent rapid refresh 
session_start();
$seconds = '3'; // Period of time [ seconds ]
$refresh = '5'; // The refresh frequency 
// Set monitoring variables 
$cur_time = time();
if(isset($_SESSION['last_time'])){
 $_SESSION['refresh_times'] += 1;
}else{
 $_SESSION['refresh_times'] = 1;
 $_SESSION['last_time'] = $cur_time;
}
// Processing monitoring results 
if($cur_time - $_SESSION['last_time'] < $seconds){
 if($_SESSION['refresh_times'] >= $refresh){
  // Jump to the attacker's server address 
  header(sprintf('Location:%s', 'http://127.0.0.1'));
  exit('Access Denied');
 }
}else{
 $_SESSION['refresh_times'] = 0;
 $_SESSION['last_time'] = $cur_time;
}
?>