'whitelist' For Fsockopen Proxy Check

[Zixtyy]

Hey

 

I'm running a website where I get quite a few proxy users evading bans. As an attempt to block them, I added this code:

 

if(@fsockopen($_SERVER['REMOTE_ADDR'], 80, $errstr, $errno, 1))
die("Your magical proxy adventure ends here.");
if(@fsockopen($_SERVER['REMOTE_ADDR'], 3128, $errstr, $errno, 1))
die("Your magical proxy adventure ends here.");
if(@fsockopen($_SERVER['REMOTE_ADDR'], 8080, $errstr, $errno, 1))
die("Your magical proxy adventure ends here.");

 

I know it probably could be a little shorter, but it worked which was the main thing. However, a few of my users run legitimate websites off their home networks, so they ended up being blocked by this. I've attempted something, but I am receiving the error:

 

syntax error, unexpected '{', expecting '('

on the first ELSE IF clause.

 

The full code is:

 

if (in_array($_SERVER['REMOTE_ADDR'], $whitelist)) {
// User is whitelisted, so we continue without going to the check.
} else if {
if (@fsockopen($_SERVER['REMOTE_ADDR'], 80, $errstr, $errno, 1) || (@fsockopen($_SERVER['REMOTE_ADDR'], 8080, $errstr, $errno, 1) || (@fsockopen($_SERVER['REMOTE_ADDR'], 3128, $errstr, $errno, 1)
} else {
// User isn't whitelisted, but is not a proxy, continue!
}

 

Can anyone point me in the right direction?

Edited October 24, 2012 by Zixtyy

[kicken]

You're missing your condition for your else if() branch.  The if below it has extra ( and no ){ at the end.

 

If you just re-structure it a little bit the code becomes easier to read and follow too.

if (!in_array($_SERVER['REMOTE_ADDR'], $whitelist)) {
   if (@fsockopen($_SERVER['REMOTE_ADDR'], 80, $errstr, $errno, 1) || @fsockopen($_SERVER['REMOTE_ADDR'], 8080, $errstr, $errno, 1) || @fsockopen($_SERVER['REMOTE_ADDR'], 3128, $errstr, $errno, 1)){
       echo "Banned";
   }
}

[Zixtyy]

Nice one! That's a lot neater than my code too. Thanks!

[Christian F.]

Another way it could be solved, is by having the ports in an array and looping through it. Will make it a bit more extensible, in case you want to add more ports to it later on.

 

Example:

$proxyPorts = array (80, 3128, 8080);
if (!in_array ($_SERVER['REMOTE_ADDR'], $whitelist)) {
   foreach ($proxyPorts as $port) {
       if (@fsockopen ($_SERVER['REMOTE_ADDR'], $port, $errstr, $errno, 1)) {
           echo 'Banned';
           break;
       }
   }
}