Function to use project honeypots black list. https://www.projecthoneypot.org/ from here: http://planetozh.com/blog/my-projects/honey-pot-httpbl-simple-php-script/

projecthoneypot check ip

<?php

/**
REFERENCE: 
  http://planetozh.com/blog/my-projects/honey-pot-httpbl-simple-php-script/
  https://www.projecthoneypot.org/
**/

function checkIfCleanIp($ipToCheck, $apikey){
  // Project Honeypot
	// your http:BL key
	// sample: $apikey = 'jlonedutoxea';
	
	// build the lookup DNS query
	// Example : for '127.9.1.2′ you should query 'abcdefghijkl.2.1.9.127.dnsbl.httpbl.org'
	$lookup = $apikey . '.' . implode('.', array_reverse(explode ('.', $ipToCheck ))) . '.dnsbl.httpbl.org';
	
	// check query response
	$result = explode( '.', gethostbyname($lookup));
	$test = gethostbyname($lookup);
	
	if ($result[0] == 127) {
		// query successful !
		$activity = $result[1];
		$threat = $result[2];
		$type = $result[3];
		
		if ($type & 0) $typemeaning .= 'Search Engine, ';
		if ($type & 1) $typemeaning .= 'Suspicious, ';
		if ($type & 2) $typemeaning .= 'Harvester, ';
		if ($type & 4) $typemeaning .= 'Comment Spammer, ';
		$typemeaning = trim($typemeaning,', ');

		return false;
		
	} else {
		return true;
	}
	
}
?>