TinyDNSDyn

This is a basic dynamic server for the djbdns DNS server 'tinydns' by Dan Bernstein. It enables a client to update its IP address via a simple HTTP based API.

It should run on any Linux or BSD with Python installed.

Requirements

• Administrative access to a server running tinydns and hence daemontools or similar (such as runit in Void linux).
• Administrative access to a *nix box on you local network.
• Python (>2.7.9) installed on both client and server.
• An open port on the server's firewall.

Installation

Server

1. Copy script and all files onto your server to the daemontools service directory (i.e. /etc/tinydnsdyn/)

2. The supplied 'run' script is tailored for debian/ubuntu and may need to be changed.

3. You can added dynamic DNS entries to your main data file or alternatively use a seperate file for dynamic entries. An existing entry in the tinydns data file should already exist. This script will NOT add one. Only those hosts listed with prefixes '+' and '=' are able to update their entries.

   For example:

    +groucho.example.com:192.168.0.2:3360
    +groucho.example.com:192.168.0.2
    =groucho.example.com:192.168.0.2:60
    +*.groucho.example.com:192.168.0.2:60
    +*.groucho.example.com:192.168.0.2
   

   will all get updated if the host groucho.example.com does a request.

4. Create a password file. This is of the format created by Apache's htpasswd and consists of one user per line in the following format:

    <username>:<crypted hash>:<optional list of domains>
   

5. The script will run 'make' in the data directory. This enables you to concatenate your data files and whatever else before they are compiled. For instance, you may need to combine all your primary and seconary zones and then add the dynamic hosts before compiling.

   An example Makefile is included with some ideas.

6. Start the service by symlinking this directory into your svscan directory (i.e. "ln $(pwd) /etc/service/" ).

Client

The service operates over HTTP and should be reasonably close to the service operated by DynDns.com having the following request format:

http://username:password@yourdnsserver.com/?hostname=yourhostname&myip=optionaladdress

The only required parameter is the hostname you wish to change. This can be a comma separated list of hostnames to update. The IP address will be determined automatically if the 'myip' parameter is missing.

The response codes are taken from here (not all of them):

http://www.dyndns.com/developers/specs/return.html

The Python code is basic and inefficient but it should work. I take no responsibility for anything that may happen to any of your machines. That said, please let me know if there are any issues.

TODO

• Better sanity checking.
• Multithread the server. Find a way to gracefully handle the data file.