我有一个问题,我建立了这个小脚本,以检查某个IP是否充斥我的网站.
当它,我否认.htaccess文件中的IP.我的问题是,有人可以告诉我这个脚本是完全没用还是值得尝试…脚本在配置文件中调用,因此它在每个页面加载上运行.
<?php
#get the visitor ip
$ip = $_SERVER["REMOTE_ADDR"];
#start the session
@session_start();
#check if the ip is banned
if( $_SESSION['~b'] ){
#check if we can open htaccess
$fp = @fopen('./.htaccess','a');
if($fp){
#add the ip to htaccess
@fwrite($fp,"\r\ndeny from $ip");
#close
@fclose($fp);
#destroy the session
@session_destroy();
@mail("my-email","IP Banned","Ip: $ip");
}
#let the user know why we deny him or her access
die('To many requests.');
}
#get the filename and location
$f = './log/'.@ip2long($ip);
#check if the file exists
if ( @is_file($f) ) {
#get the last filetime
$a = @filemtime($f);
#touch the file, give a new filetime
@touch($f,time());
#the ip is not banned
$_SESSION['~b'] = false;
#add the time diff
$_SESSION['~r'] += @time()-$a;
#add the latest hit
$_SESSION['~h'] += 1;
}else{
#create the file if it doesn't exist
@file_put_contents($f,''); #size: 0kb
#if touch() doesn't work
#chmod($ipfile,0755);
}
#calculate the diff after 10 hits, and ban when the avg is smaller than 0.25 seconds
if( $_SESSION['~h'] > 10 && ($_SESSION['~r']/$_SESSION['~h']) < 0.25 ) $_SESSION['~b'] = true;
?>
只是按照建议来避免SESSIONS,所以我把它建立在文件的基础上,而不必依赖于cookie和会话:
<?php
# get the visitor ip
$i = $_SERVER["REMOTE_ADDR"];
# get the filename and location
$f = './log/'.ip2long($i).'.dat';
# check if the file exists and we can write
if ( is_file($f) ) {
# get the last filetime
$a = filemtime($f);
# get the file content
$b = file_get_contents($f);
# create array from hits & seconds
$d = explode(':',$b);
# calculate the new result
$h = (int)$d[0] + 1;
$s = (int)$d[1] + (time()-$a);
# add the new data tot text file
file_put_contents($f,"$h:$s",LOCK_EX);
unset($d);
}else{
# create the file if it doesn't exist hits:seconds
file_put_contents($f,"1:1",LOCK_EX); #size: 3kb
# to make sure we can write
# chmod($f,0755);
# set the hits to zero
$h = 0;
}
# create a result var
$r = $h > 10 ? (float)$s/$h : (float)1;
# calculate the diff after 10 hits, and ban when the avg is smaller than 0.20 seconds (5 hits per second)
if( $r < 0.20 ) {
# check if we can open htaccess
$fp = @fopen('./.htaccess','a');
if($fp){
# add the ip to htaccess
@fwrite($fp,"\r\ndeny from $i");
# close
@fclose($fp);
# mail the admin
@mail("email","IP Banned","Ip: $i with $r sbh (Seconds Between Hits)");
}
# let the user know why we deny him or her access
die('To many requests.');
# remove the file
unlink($f);
}
# if the user leaves, reset
if( $r > 30 ) {
unlink($f);
}
echo 'Result: '.$r.'sbh (Seconds Between Hits)';
?>
最佳答案 如果你想阻止临时用户在一定时间内发送太多请求,那么是的,脚本可以工作.打开一个catpcha屏幕,你正在做生意.
但
真正的答案是否定的.
此代码的主要错误取决于会话以确定用户活动的频率.一个“好”的攻击者可以通过禁用cookie的请求来淹没您的服务器,以及欺骗他/她的IP.
阻止攻击的一种方法是转到服务器级别,然后安装iptables.事实上,iptables附带了大多数Linux发行版.它需要很少的配置,并且开箱即用.
另一种方法是,如果您具有对服务器的root访问权限,则将会话处理移动到Memcached.它有一个叫做洪水控制的功能,非常漂亮.
另一种防止DDOS的途径来自第三方服务,例如
blockdos
http://www.blockdos.net/
有点贵,但它可能适合你.
但PHP本身无法配置为处理DDOS攻击.在转到PHP脚本之前,您需要在所有要审查的请求之前放置某种设备或防火墙.