<?php
/*
Posted @ http://www.w3tools.info/2011/12/anti-ddos-php-script.html
*/

 $ Ad_ddos_query = 10, / / ​​number of requests per second to detect DDOS attacks 
 $ Ad_check_file = 'check.txt'; / / file to write the current state during the monitoring 
 $ Ad_temp_file = 'all_ip.txt'; / / temporary file 
 $ Ad_black_file = 'black_ip.txt'; / / will be entered into a zombie machine ip 
 $ Ad_white_file = 'white_ip.txt'; / / ip logged visitors 
 $ Ad_dir = 'anti_ddos'; / / directory with scripts 
 $ Ad_num_query = 0, / / ​​current number of requests per second from a file $ check_file 
 $ Ad_sec_query = 0, / / ​​second from a file $ check_file 
 $ Ad_end_defense = 0, / / ​​end while protecting the file $ check_file 
 $ Ad_sec = date ("s"); / / current second 
 $ Ad_date = date ("mdHis"); / / current time 
 $ Ad_defense_time = 10000 / / ddos ​​attack detection time in seconds at which stops monitoring 



 if (! file_exists ("{$ ad_dir} / {$ ad_check_file}") or! file_exists ("{$ ad_dir} / {$ ad_temp_file}") or! file_exists ("{$ ad_dir} / {$ ad_black_file}") or ! file_exists ("{$ ad_dir} / {$ ad_white_file}") or! file_exists ("{$ ad_dir} / anti_ddos.php")) { 
 die ("Not enough files."); 
 } 

 require ("{$ ad_dir} / {$ ad_check_file}"); 

 if ($ ad_end_defense and $ ad_end_defense> $ ad_date) { 
 require ("{$ ad_dir} / anti_ddos.php"); 
 } Else { 
 if ($ ad_sec == $ ad_sec_query) { 
 $ Ad_num_query + +; 
 } Else { 
 $ Ad_num_query = '1 '; 
 } 

 if ($ ad_num_query> = $ ad_ddos_query) { 
 $ Ad_file = fopen ("{$ ad_dir} / {$ ad_check_file}", "w"); 
 $ Ad_end_defense = $ ad_date + $ ad_defense_time; 
 $ Ad_string = '<? Php $ ad_end_defense ='. $ Ad_end_defense. ';?>'; 
 fputs ($ ad_file, $ ad_string); 
 fclose ($ ad_fp); 
 } Else { 
 $ Ad_file = fopen ("{$ ad_dir} / {$ ad_check_file}", "w"); 
 $ Ad_string = '<? Php $ ad_num_query ='. $ Ad_num_query. '; $ Ad_sec_query ='. $ Ad_sec. ';?>'; 
 fputs ($ ad_file, $ ad_string); 
 fclose ($ ad_fp); 
 } 
 } 
 ?>