cron – Paranoids Blog

Need a simple dyndns service.
Here my crappy 10 minutes approach to get this done:

curl -> webserver -> mysql -> cronjob -> namedZoneFile

Here my curl client cronjob every minute:

/usr/bin/curl --silent --user username:password http://dyn.xxx.xx

Webserver PHP implementation:

.htaccess

<IfModule mod_rewrite.c>
RewriteEngine on
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization},L]
</IfModule>

index.php

<?php

$ipAddress = $_SERVER['REMOTE_ADDR'];

if (!isset($_SERVER['PHP_AUTH_USER'])) {
  header('WWW-Authenticate: Basic realm="paranoids.at DynDns"');
  header('HTTP/1.0 401 Unauthorized');
  echo 'No Auth, Try again';
} 
else {
  $isAuth = getUserPass($_SERVER['PHP_AUTH_USER'],$_SERVER['PHP_AUTH_PW']);
  if (!empty($isAuth)) {
    if (empty(ifHostExists($isAuth['id']))) {
      insertHost($isAuth['id'], $ipAddress);
    }
    else {
      $host = ifHostExists($isAuth['id']);
      if (strcmp($host['ip'], $ipAddress) !== 0) {
        updateHost($host['userid'], $ipAddress);
      } 
    }
  }
  else {
    echo 'Wrong Auth, Try again';
  }
}

connect_db_dyn()->close();

function ifHostExists($userid) {
  $result = connect_db_dyn()->query("SELECT * FROM host WHERE userid='$userid';");
  return $result->fetch_assoc();
}

function getUserPass($user,$pass) {
  $result = connect_db_dyn()->query("SELECT * FROM user WHERE username='$user' AND password='$pass' LIMIT 1;");
  return $result->fetch_assoc();
}

function insertHost($userid,$newip) {
  connect_db_dyn()->query("INSERT INTO host (userid, ip, changed) VALUES ('$userid', '$newip', '1');");
}

function updateHost($userid,$ip) {
  connect_db_dyn()->query("UPDATE host SET ip='$ip', changed=1, timestamp=CURRENT_TIMESTAMP WHERE userid='$userid';");
}

function connect_db_dyn() {
  $dbh = new mysqli('localhost', 'username', 'password', 'database');
  return $dbh;
}

?>

Database dump:

-- phpMyAdmin SQL Dump
-- version 4.6.4
-- https://www.phpmyadmin.net/
--
-- Host: localhost

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";

--
-- Database: `database`
--

-- --------------------------------------------------------

--
-- Table structure for table `host`
--

CREATE TABLE `host` (
 `id` int(11) NOT NULL,
 `userid` int(11) NOT NULL,
 `ip` varchar(255) NOT NULL,
 `timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
 `changed` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

--
-- Dumping data for table `host`
--

INSERT INTO `host` (`id`, `userid`, `ip`, `timestamp`, `changed`) VALUES
(14, 1, '1.1.1.1', '2016-11-30 04:38:03', 0);

-- --------------------------------------------------------

--
-- Table structure for table `user`
--

CREATE TABLE `user` (
 `id` int(11) NOT NULL,
 `username` varchar(255) NOT NULL,
 `password` varchar(255) NOT NULL,
 `comment` varchar(255) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

--
-- Dumping data for table `user`
--

INSERT INTO `user` (`id`, `username`, `password`, `comment`) VALUES
(1, 'username1', 'password1', 'comment1');

--
-- Indexes for dumped tables
--

--
-- Indexes for table `host`
--
ALTER TABLE `host`
 ADD PRIMARY KEY (`id`);

--
-- Indexes for table `user`
--
ALTER TABLE `user`
 ADD PRIMARY KEY (`id`);

--
-- AUTO_INCREMENT for dumped tables
--

--
-- AUTO_INCREMENT for table `host`
--
ALTER TABLE `host`
 MODIFY `id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=15;
--
-- AUTO_INCREMENT for table `user`
--
ALTER TABLE `user`
 MODIFY `id` int(11) NOT NULL AUTO_INCREMENT, AUTO_INCREMENT=3;

dnsserverside cronjob every minute:

<?php

if (!empty(getChange())) {
 deleteHosts();
 updateHosts();
 writeBind();
}

connect_Db_Dyn()->close();

function getChange() {
 $result = connect_Db_Dyn()->query("SELECT * FROM host WHERE changed = 1");
 return $result->fetch_assoc();
}

function getHosts() {
 $result = connect_Db_Dyn()->query("SELECT * FROM host");
 return $result->fetch_all($resulttype = MYSQLI_ASSOC);
}

function deleteHosts() {
 connect_Db_Dyn()->query("DELETE FROM host WHERE timestamp < date_add(current_date, interval -14 day) LIMIT 1000;");
}

function updateHosts() {
 connect_Db_Dyn()->query("UPDATE host SET changed=0;");
}

function getUsernameById($userid) {
 $result = connect_Db_Dyn()->query("SELECT username FROM user WHERE id='$userid'");
 $row = $result->fetch_assoc();
 return $row['username'];
}

function connect_Db_Dyn() {
 $dbh = new mysqli('localhost', 'username', 'password', 'database');
 return $dbh;
}

function writeBind() {
$date = new DateTime();
$texthead = '$TTL 60
@ IN SOA ns1.xxxx.xx. hostmaster.xxxx.xxx. (
 sedSerial ; serial, unix timestamp  #
 7200 ; refresh, seconds
 540 ; retry, seconds
 604800 ; expire, seconds
 3600 ) ; minimum, seconds
;'."\n\n";

$texthead = preg_replace("/sedSerial/",$date->getTimestamp(),$texthead);

$textbody = "@"."\t"."A"."\t"."1.1.1.1"."\n";

foreach (getHosts() as $host) {
 $textbody .= getUsernameById($host['userid'])."\t"."A"."\t".$host['ip']."\n";
}

$textfooter = '
@ NS ns2.xxx.xx.
@ NS ns1.xxx.xx.
';
$file = $texthead.$textbody.$textfooter;

file_put_contents("/etc/bind/dns.xxx.xx", $file);

system('/usr/sbin/rndc -q reload');

}

?>

Bind named.conf:

zone "dns.xxx.xx" {
 type master;
 allow-transfer {1.1.1.1;2:1:1::2;};
 file "/etc/bind/dns.xxx.xx";
};

Have fun!

Tag: cron

Simple PHP Mysql Bind dynamic DNS Service