Introduction
Introduction – Introduction to Net_DNSBL
Description
PEAR::Net_DNSBL provides an easy way to check if a given Host or URL is listed on an DNS-based Blackhole List (DNSBL, Real-time Blackhole List or RBL) or Spam URI Realtime Blocklist (SURBL).
Please not that this currently only works with IPv4 IPs.
Usage
Let's start with a simple example to check if the remote host is listed in two blacklists:
<?php
require_once 'Net/DNSBL.php';
$dnsbl = new Net_DNSBL();
$remoteIP = $_SERVER['REMOTE_ADDR'];
$remoteIP = '81.70.69.193';
$dnsbl->setBlacklists(array('sbl-xbl.spamhaus.org', 'bl.spamcop.net'));
if ($dnsbl->isListed($remoteIP)) {
// do something
}
?>
This example shows how to check if an URL is listed in a SURBL:
<?php
require_once 'Net/DNSBL/SURBL.php';
$surbl = new Net_DNSBL_SURBL();
if ($surbl->isListed('http://test.multi.surbl.org/')) {
// do something
}
?>
An example how to extract URLS from a text can be found on http://www.phpfreaks.com/quickcode/Extract_All_URLs_on_a_Page/15.php and be used this way:
<?php
foreach ($extracted_urls as $surbl_check_url) {
if ($surbl->isListed($surbl_check_url)) {
// do something
break;
}
}
?>
Let's get some details, if our host is listed:
<?php
require_once 'Net/DNSBL.php';
$dnsbl = new Net_DNSBL();
$dnsbl->setBlacklists(array('sbl-xbl.spamhaus.org', 'bl.spamcop.net'));
if ($dnsbl->isListed($_SERVER['REMOTE_ADDR'])) {
var_dump($dnsbl->getDetails($_SERVER['REMOTE_ADDR']));
var_dump($dnsbl->getTxt($_SERVER['REMOTE_ADDR']));
var_dump($dnsbl->getListingBl($_SERVER['REMOTE_ADDR']));
var_dump($dnsbl->getListingRecord($_SERVER['REMOTE_ADDR']));
}
?>