<?php
/*
        ******************************************************************************
        CPG-HttpBL Plugin
        ******************************************************************************
        Author: Mario Oyorzabal Salgado
        Blog:   http://blog.tuxsoul.com/
        E-mail: <tuxsoul@tuxsoul.com>
        Web:    http://code.google.com/p/cpg-dnsbl/
        Donate: http://tinyurl.com/36mzoa
        ******************************************************************************
        This program is free software; you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation; either version 2 of the License, or
        (at your option) any later version.
        ******************************************************************************
*/
 
// can't execute directly this file
// you are lost ?
if (!defined('HTTPBL_CWD')) {
	die ('You are lost ?');
}
 
// main class object
class coreHttpBL 
{
	var $coreHttpBLIp;
	var $coreHttpBLError;
 
	var $coreHttpBLConfVersion;
	var $coreHttpBLConfDnsbl;
	var $coreHttpBLConfDays;
 
	function coreHttpBL () {
		// set flag error to cero
		$this->coreHttpBLError = 0;
 
		// config
		// version of this core
		$this->coreHttpBLConfVersion = '0.1';
 
		// spammer days since last activity
		$this->coreHttpBLConfDays = '15';
 
		// define query to dnsbl
		$this->coreHttpBLConfDnsbl = '{key}.{ip}.dnsbl.httpbl.org';
	}
 
	// return version of this core
	function coreHttpBLVersion () {
		return $this->coreHttpBLConfVersion;
	}
 
	// start the search to spammer's
	function coreHttpBLStart () {
		// detect ip
		$this->coreHttpBLDetectIp();
 
		// reverse-octet ip address
		// change data of query
		$host = $this->coreHttpBLDnsblPrepareQuery();
 
		// make query and get response
		$response = $this->coreHttpBLDnsblQuery($host);
 
		// Is spammer ?
		if($this->coreHttpBLIsSpammer($response) == 1) {
			// Get the trap
			$this->coreHttpBLShowTrap();
		}
	}
 
	// try to detect the remote ip
	function coreHttpBLDetectIP () {
		$ip = $_SERVER['REMOTE_ADDR'];
 
		// only for test
		// $ip = '127.1.1.1';
 
		$this->coreHttpBLIp = $ip;
	}
 
	// change data of query to dnsbl
	function coreHttpBLDnsblPrepareQuery () {
		// reverse-octet ip format
		$reverseIp = implode('.', array_reverse(explode('.', $this->coreHttpBLIp)));
 
		// prepare query to dnsbl
		$string = $this->coreHttpBLConfDnsbl;
		$string = ereg_replace('{key}', HTTPBL_KEY, $string);
		$string = ereg_replace('{ip}', $reverseIp, $string);
 
		return $string;
	}
 
	// make the query to dnsbl server
	function coreHttpBLDnsblQuery ($host) {
		$response = gethostbyname($host);
 
		if($response == $host)
			$this->coreHttpBLError = 1;
 
		return $response;
	}
 
	// is spammer ?
	function coreHttpBLIsSpammer ($response) {
		if($this->coreHttpBLError == 0) {
			$data = explode('.', $response);
			$spammer = 0;
 
			// the first octect always is 127
			if((int)$data[0] == 127) {
				// spammer days since last activity
				if((int)$data[1] <= $this->coreHttpBLConfDays) {
					// only check the type of spammer
					if((int)$data[3] > 0) {
						$spammer = 1;
					}
				}		
			}
			else
				$this->coreHttpBLError = 1;
 
			return $spammer;
		}
 
		return 0;
	}
 
	// redirect to the trap
	function coreHttpBLShowTrap () {
		if($this->coreHttpBLError == 0) {
			// FIXME: HTTPBL_TRAP is set correctly ?
			if(strlen(HTTPBL_TRAP) > 0) {
				header('Location: ' . HTTPBL_TRAP);
				die();
			}
		}
	}
 
	// return url to trap in html
	// FIXME: Need more work here :)
	function coreHttpBLGetUrlTrap () {
		$text = '<!-- begin links ' . HTTPBL_TRAP_WORD . ' -->';
 
		// FIXME: HTTPBL_TRAP is set correctly ?
		if(strlen(HTTPBL_TRAP) > 0) {
			$url = array (
					'<a href="{url}"><!-- {word} --></a>',
					'<a href="{url}" style="display: none;">{word}</a>',
					'<div style="display: none;"><a href="{url}">{word}</a></div>',
					'<a href="{url}"></a>',
					'<!-- <a href="{url}">{word}</a> -->',
					'<div style="position: absolute; top: -250px; left: -250px;"><a href="{url}">{word}</a></div>',
					'<a href="{url}"><span style="display: none;">{word}</span></a>',
				);
 
			for($x = 0; $x <= 2; $x++) {
				$temp = $url[rand(0, 6)];
				$temp = ereg_replace('{url}', HTTPBL_TRAP, $temp);
				$temp = ereg_replace('{word}', HTTPBL_TRAP_WORD, $temp);
 
				$text .= $temp;
			}
 
			$text .= '<!-- end links '. HTTPBL_TRAP_WORD . ' -->';
		}
 
		return $text;
	}
}
?>