Fake a 404 to Block an Entire ISP
Posted by Nessa | Posted in code,php | Posted on May 6, 2007
0
I’ve been getting a sudden influx of traffic so I decided to take a look at my referrer stats, and even though there wasn’t anything blatently obvious out there, I did notice some strange injection-like URL strings coming from a certain ISP. I figured the best way to block them without having to figure out and set an IP range to block is to just fake the existence of my whole website. Here’s how you can force users from an entire [unwanted] ISP to a 404 page…you’d want to put this in a page that is consistently loaded with your site. If you’re a WordPress user, the best spot would be your header.php.
$host = gethostbyaddr($REMOTE_ADDR);
if (stristr($host, "anyisp.com")) {
Header("HTTP/1.1 404 Not Found");
print "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">
<HTML><HEAD>
<TITLE>404 Not Found</TITLE>
</HEAD><BODY>
<H1>Not Found</H1>
The requested URL / was not found on this server.<P>
<P>Additionally, a 404 Not Found
error was encountered while trying to use an ErrorDocument to handle the request.
<HR>
<ADDRESS>Apache/1.3.37 Server at www.v-nessa.net Port 80</ADDRESS>
</BODY></HTML>";
exit;
}
?>
No related posts.
