Proxy check

gistfile1.php

<?php
/**
 * Controlla che non si tratti di un proxy
 */
function ipProxyPortCheck( $ip ){
        
	//timeout you want to use to test
	$timeout = 5;
	
	// ports we're going to check
	$ports = array(80,3128,8080);
	
	// flag to be returned 0 means safe, 1 means open and unsafe
	$flag = false;
	
	// loop through each of the ports we're checking
	foreach( $ports as $port ){
	
		// this is the code that does the actual checking for the port
		@$fp = fsockopen($ip,$port,$errno,$errstr,$timeout);
		
		// test if something was returned, ie the port is open
		if( !empty( $fp ) ){
		
			// we know the set the flag
			$flag = true;
			
			// close our connection to the IP
			fclose($fp);
			
		}
	}
	
	// send our flag back to the calling code
	return $flag;
}