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Dns plaintext - return all A/AAAA records (#85)
* better dns resolving - return all A/AAAA records * update * csfixer
1 parent de732f6 commit a25393b

6 files changed

Lines changed: 154 additions & 167 deletions

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‎CHANGELOG.md‎

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@@ -12,6 +12,7 @@
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* feature: Add configurable test timeout
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* feature: Add Servcheck graph template
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* issue: Better themes support
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* issue: Better plaintext DNS - return all A and AAAA records
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--- 0.3 ---
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‎README.md‎

Lines changed: 1 addition & 1 deletion
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@@ -35,7 +35,7 @@ HTTP and HTTPS - returns webpage
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SMTP, SMTPS - connect to SMTP server and displays banner and EHLO/HELO or authentication result
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POP3, POP3S - try to server connection and eventually login and display first unread message
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IMAP, IMAPS - try to server connection and eventually login and display unread messages in inbox
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DNS, DOH - try to resolve A record and return answer
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DNS, DOH - try to resolve A (and AAAA for plaintext dns) record and return answer
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LDAP and LDAPS - do searching in LDAP
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FTP, FTPS, SFTP - try to login and return directory listing
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TFTP - try to download specific file

‎includes/arrays.php‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -467,7 +467,7 @@
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'dns_query' => [
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'method' => 'textbox',
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'friendly_name' => __('DNS Name for Query', 'servcheck'),
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'description' => __('DNS name for querying. For DOH (DNS over HTTPS) use /resolve?name=example.com or /dns-query?name=example.com&type=A', 'servcheck'),
470+
'description' => __('DNS name for querying. For DOH (DNS over HTTPS) use /resolve?name=example.com or /dns-query?name=example.com&type=A. For plaintext DNS A and AAAA records will be returned', 'servcheck'),
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'value' => '|arg1:dns_query|',
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'max_length' => '40',
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'size' => '30'

‎includes/dnslookup.php‎

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<?php
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/*
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+-------------------------------------------------------------------------+
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| Copyright (C) 2004-2026 The Cacti Group |
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| |
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| This program is free software; you can redistribute it and/or |
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| modify it under the terms of the GNU General Public License |
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| as published by the Free Software Foundation; either version 2 |
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| of the License, or (at your option) any later version. |
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| |
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| This program is distributed in the hope that it will be useful, |
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| but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| GNU General Public License for more details. |
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+-------------------------------------------------------------------------+
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| Cacti: The Complete RRDtool-based Graphing Solution |
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+-------------------------------------------------------------------------+
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| This code is designed, written, and maintained by the Cacti Group. See |
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| about.php and/or the AUTHORS file for specific developer information. |
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+-------------------------------------------------------------------------+
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| http://www.cacti.net/ |
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+-------------------------------------------------------------------------+
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*/
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class dnslookup {
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private $dns_reply = '';
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private $cIx = 0;
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private $results = [];
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function __construct($domain, $dns = '8.8.8.8', $timeout = 5) {
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$this->dns_query($domain, 1, $dns, $timeout, 'A');
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$this->dns_query($domain, 28, $dns, $timeout, 'AAAA');
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}
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public function get_results($format = 'text') {
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$output = '';
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if (empty($this->results)) {
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return false;
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}
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foreach ($this->results as $type => $ips) {
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foreach ($ips as $ip) {
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$output .= " $ip\n";
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}
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$output .= "\n";
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}
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return $output;
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}
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private function dns_query($domain, $qtype, $dns, $timeout, $type) {
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$header = chr(0x12) . chr(0x34) . chr(0x01) . chr(0x00) . chr(0x00) . chr(0x01) .
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chr(0x00) . chr(0x00) . chr(0x00) . chr(0x00) . chr(0x00) . chr(0x00);
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$packet = $header . $this->dns_name($domain) .
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chr(0x00) . chr($qtype) . chr(0x00) . chr(0x01);
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$socket = @fsockopen("udp://$dns", 53, $errno, $errstr, $timeout);
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if (!$socket) {
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return false;
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}
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fwrite($socket, $packet);
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stream_set_timeout($socket, $timeout);
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$this->dns_reply = fread($socket, 512);
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fclose($socket);
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$len = strlen($this->dns_reply);
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if ($len > 12) {
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$this->cIx = 12;
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$this->parse_response($type, $len);
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}
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}
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private function dns_name($domain) {
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$parts = explode('.', $domain);
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$name = '';
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foreach ($parts as $part) {
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$len = strlen($part);
84+
$name .= chr($len);
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$name .= $part;
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}
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return $name . chr(0);
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}
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private function parse_response($type_name, $reply_len) {
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// Skip question
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$max_skip = min(255, $reply_len - $this->cIx);
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for ($i = 0; $i < $max_skip; $i++) {
96+
if (ord($this->dns_reply[$this->cIx]) == 0) {
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$this->cIx++;
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break;
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}
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$this->cIx++;
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}
103+
$this->cIx += 4;
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105+
$ancount = ord($this->dns_reply[7]) * 256 + ord($this->dns_reply[8]);
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for ($i = 0; $i < min($ancount, 10); $i++) {
108+
if ($this->cIx + 12 > $reply_len) {
109+
break;
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}
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$this->cIx += 2; // name pointer
113+
$type = ord($this->dns_reply[$this->cIx]) * 256 + ord($this->dns_reply[$this->cIx + 1]);
114+
$this->cIx += 8; // CLASS + TTL
115+
$rdlen = ord($this->dns_reply[$this->cIx]) * 256 + ord($this->dns_reply[$this->cIx + 1]);
116+
$this->cIx += 2;
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118+
if ($this->cIx + $rdlen > $reply_len) {
119+
break;
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}
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122+
if ($type == 1 && $rdlen == 4) {
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// IPv4
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$ip = ord($this->dns_reply[$this->cIx]) . '.' .
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ord($this->dns_reply[$this->cIx + 1]) . '.' .
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ord($this->dns_reply[$this->cIx + 2]) . '.' .
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ord($this->dns_reply[$this->cIx + 3]);
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$this->results['A'][] = $ip;
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} elseif ($type == 28 && $rdlen == 16) {
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// IPv6
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$ipv6 = '';
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for ($j = 0; $j < 16; $j += 2) {
134+
$byte1 = ord($this->dns_reply[$this->cIx + $j]);
135+
$byte2 = ord($this->dns_reply[$this->cIx + $j + 1]);
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$ipv6 .= sprintf('%02x%02x', $byte1, $byte2);
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138+
if ($j < 14) {
139+
$ipv6 .= ':';
140+
}
141+
}
142+
$this->results['AAAA'][] = $ipv6;
143+
}
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$this->cIx += $rdlen;
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}
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}
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}

‎includes/mxlookup.php‎

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This file was deleted.

‎includes/test_dns.php‎

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Original file line numberDiff line numberDiff line change
@@ -23,7 +23,7 @@
2323
*/
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2525
function dns_try($test) {
26-
include_once(__DIR__ . '/../includes/mxlookup.php');
26+
include_once(__DIR__ . '/../includes/dnslookup.php');
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2828
// default result
2929
$results['result'] = 'error';
@@ -38,18 +38,16 @@ function dns_try($test) {
3838

3939
servcheck_debug('Querying ' . $test['hostname'] . ' for record ' . $test['dns_query']);
4040

41-
$a = new mxlookup($test['dns_query'], $test['hostname'], $test['duration_trigger'] > 0 ? ($test['duration_trigger'] + 2) : read_config_option('servcheck_test_max_duration'));
41+
$a = new dnslookup($test['dns_query'], $test['hostname'], $test['duration_trigger'] > 0 ? ($test['duration_trigger'] + 2) : read_config_option('servcheck_test_max_duration'));
4242

43-
if (!cacti_sizeof($a->arrMX)) {
43+
if ($a === false) {
4444
$results['result'] = 'error';
4545
$results['error'] = 'Server did not respond';
4646
$results['result_search'] = 'not tested';
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4848
servcheck_debug('Test failed: ' . $results['error']);
4949
} else {
50-
foreach ($a->arrMX as $m) {
51-
$results['data'] .= "$m\n";
52-
}
50+
$results['data'] .= $a->get_results();
5351

5452
$results['result'] = 'ok';
5553
$results['error'] = 'Some data returned';

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