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[0] in function chmod in /var/www/hopeinstoughton_www/wp-content/plugins/simple-universal-google-analytics/main.php on line 8
[1] in function include_once in /var/www/hopeinstoughton_www/wp-settings.php on line 560
[2] in function require_once in /var/www/hopeinstoughton_www/wp-config.php on line 85
[3] in function require_once in /var/www/hopeinstoughton_www/wp-load.php on line 50
[4] in function require_once in /var/www/hopeinstoughton_www/wp-blog-header.php on line 13
[5] in function require in /var/www/hopeinstoughton_www/index.php on line 17

<?php

# https://github.com/metaregistrar/php-dns-client

/* 
	Requires the following changes for Amazon TXT (eg DKIM records) 
	
	dnsResponse.php:
                case 'TXT':
                    $result = new dnsTXTresult(substr($buffer, $this->responsecounter, $ans_header['length']));
					$this->responsecounter += $ans_header['length'] ;
                    break;
	
	dnsTXTresult.php:
        public function __construct($record)
        {
            parent::__construct();
            
            $length = 0;
            $txt = '';
			while ($record != '') {
				$c = ord($record[0]);
				$length += $c;
				$txt .= substr($record, 1, $c);
				$record = substr($record, $c + 1);
				
			}
            $this->recordlength = $length;
            $this->setRecord($txt);
        }
	
*/

namespace modules\apiDNSclient;

use Metaregistrar\DNS\dnsProtocol;

	function _is_a($item, $objecttype) {
		$itemclass = strtolower(get_class($item));
		return $itemclass == $objecttype; 
	}
	
	function _asTime($duration) {
		$seconds = $duration . 's';
		$ss = $duration % 60;
		$mm = intval($duration / 60);
		$hh = intval($mm / 60); $mm = $mm % 60;
		$hms = '(' . $hh . 'h ' . $mm . 'm ' . $ss . 's)';
		return "<span title=\"$hms\">$seconds</span>";
	}


class main extends \moduleMain {

	public function __construct() {
		parent::__construct(__DIR__);
	}

	public function Activate() {
		hook_add('dns.lookup', [$this, '__dns_lookup']);
		hook_add('email.validate', [$this, '__validate_email'], 1);
	}
	
	private function _GetNameServers($servers) {
		$default = ['8.8.8.8', '8.8.4.4'];		// this should be a setting
		if ($servers === NULL) $servers = [];
		if (!is_array($servers)) $servers = [ $servers ];
		if (!count($servers)) return $default;
		
		$output = [];
		foreach($servers as $server) {
			if (!filter_var($server, FILTER_VALIDATE_IP)) {		// have a hostname 
				$res = $this->lookup($server, $default);
				if ($res !== FALSE) $output[] = $res;
			} else {
				$output[] = $server;
			}
		}
		return $output;
	}
	
	public function __dns_lookup(&$result, $query, $type, $servers = NULL) {
		
		$serverlist = $this->_GetNameServers($servers);
		$n = new dnsProtocol();
		$n->SetConnectionTimeout(2.0);
		$n->SetReadTimeout(2.0);
		$n->SetServer($serverlist[0]);
		
//		$answer = $n->Query($query . '.', $type);
		$answer = $n->Query($query, $type);
	
		if (is_object($answer)) {
			foreach($answer->getResourceResults() as $item) {			// Answers
				$result[] = $this->_addItem($item, 'Answer');
			}

			foreach($answer->getNameserverResults() as $item) {			// name server
				$result[] = $this->_addItem($item, 'Authority');
			}
			
			foreach($answer->getAdditionalResults() as $item) {
				$result[] = $this->_addItem($item, 'Additional');
			}
		}
	}
	
	private function _addItem($itemdata, $section) {
		
		$name = $itemdata->getDomain(); 
		$class = $itemdata->getClass();
		$typeid = $itemdata->getTypeId(); 
		$duration = $itemdata->getTtl();
		$raw = $data = ''; 
		switch($typeid) {
			case 'MX':
				$pref = $itemdata->getPrio();
				$ex = $itemdata->getServer();
				$data = "<table cellpadding=\"2\" cellspacing=\"0\" border=\"0\" width=\"100%\">".
				"<tr><td>preference:</td><td align=\"right\">$pref</td></tr>".
				"<tr><td>exchange:</td><td align=\"right\">$ex</td></tr></table>";
				$raw = $ex;
				break;
				
			case 'SOA':
				$s_server = $itemdata->getNameserver();
				$s_email =  $itemdata->getResponsible();
				$s_serial = $itemdata->getSerial();
				$s_refresh =_asTime($itemdata->getRefresh());
				$s_retry =  _asTime($itemdata->getRetry());
				$s_expire = _asTime($itemdata->getExpiry());
				$s_minttl = _asTime($itemdata->getMinttl());
				$data = "<table cellpadding=\"2\" cellspacing=\"0\" border=\"0\" width=\"100%\">".
				"<tr><td>server:</td><td align=\"right\">$s_server</td></tr>".
				"<tr><td>email:</td><td align=\"right\">$s_email</td></tr>".
				"<tr><td>serial:</td><td align=\"right\">$s_serial</td></tr>".
				"<tr><td>refresh:</td><td align=\"right\">$s_refresh</td></tr>".
				"<tr><td>retry:</td><td align=\"right\">$s_retry</td></tr>".
				"<tr><td>expire:</td><td align=\"right\">$s_expire</td></tr>".
				"<tr><td>minimum ttl:</td><td align=\"right\">$s_minttl</td></tr></table>";
				break;
				
			case 'CNAME':
				$data = $itemdata->getRedirect();
				$raw = $data;
				break; 
				
			case 'NS':
				$data = $itemdata->getNameserver();
				$raw = $data;
				break; 
				
			case 'AAAA':
				$data = $itemdata->getIpv6long();
				$raw = $data;
				break; 
				
			case 'PTR':
				$data = $itemdata->getData();
				$raw = $data;
				break; 

			case 'A':
				$data = $itemdata->getIpv4();
				$raw = $data;
				break; 

			case 'TXT':
				$data = $itemdata->getRecord();
				$raw = $data;
				break; 
				
			default:			// unknown object type
				echo "item: <pre>";
				var_dump($itemdata);
				echo "</pre>";
				exit;
	//		$data = $itemdata['data']; 
		}
		$time = _asTime($duration);
		return [$name, $class, $typeid, $data, $time, $raw];
		return "<tr><td valign=\"top\">$name</td><td valign=\"top\">$class</td>".
			"<td valign=\"top\">$type</td><td valign=\"top\">$data</td>".
	//		"<td valign=\"top\" align=\"right\">$seconds</td><td valign=\"top\">$hms</td></tr>\n";
			"<td valign=\"top\" align=\"right\">$time</td></tr>\n";
	}
	
	// is the host part of an email address point to a valid server
	public function __validate_email(&$result, $email_address) {
		if (strpos($email_address, '@') === FALSE) {
			$result[] = 'This does not look like an email address (missing "@")';
			return;
		}
		
		[ $username, $domain ] = explode('@', $email_address, 2);
		$domain = strtolower($domain);

		if (strpos($domain, '.') === FALSE) {
			$result[] = 'domain part should contain at least one period';
			return;
		}

	
		$answer = hook_execute('dns.lookup', [], $domain, 'MX');
		$mailhost = $answer[0][5] ?? '';
		if ($mailhost == '') {
			$result[] = 'Invalid email address. No "MX" records are configured for "' . $domain .'"';
			return;
		}
		
		// make sure it is a A record, not a CNAME
		$answer = hook_execute('dns.lookup', [], $mailhost, 'CNAME');
		$cname = $answer[0][5] ?? '';
		if ($cname != '') {
			$result[] = 'Invalid email address, server configuration error. "CNAME" record found for "' . $domain .'" mail server';
			return;
		}
		$answer = hook_execute('dns.lookup', [], $mailhost, 'A');
		$cname = $answer[0][5] ?? '';
		if ($cname == '') {
			$return[] = 'Invalid email address, server configuration error. No "A" record found for "' . $domain .'" mail server';
			return;
		}

	}
	
}