iodine - IP over DNS is now easy

   http://code.kryo.se/iodine

********************************

This is a piece of software that lets you tunnel IPv4 data through a DNS
server. This can be usable in different situations where internet access is
firewalled, but DNS queries are allowed.


HOW TO USE:

Server side:
To use this tunnel, you need control over a real domain (like mytunnel.com),
and another computer with a static public IP number that does not yet run a DNS
server. Then, delegate a subdomain (say, tunnel1.mytunnel.com) to the computer.
If you use BIND for the domain, add these lines to the zone file:

tunnel1host	IN	A	10.15.213.99

$ORIGIN tunnel1.mytunnnel.com.
@		IN	NS	tunnel1host.mytunnel.com.

Now any DNS querys for domains ending with tunnel1.mytunnnel.com will be sent
to your server. Start iodined on the server. The first argument is the tunnel
IP address (like 192.168.99.1) and the second is the assigned domain (in this
case tunnel1.mytunnel.com). The -f argument will keep iodined running in the
foreground, which helps when testing. iodined will start a virtual interface,
and also start listening for DNS queries on UDP port 53. Now everything is
ready for the client.

Client side:
All the setup is done, just start iodine. It also takes two arguments, the
first is the server (10.15.213.99 or tunnel1host.mytunnel.com) and the second
is the domain used (tunnel1.mytunnnel.com). The tunnel interface will get an IP
close to the servers (in this case 192.168.99.2) and a suitable MTU. Now you
should be able to ping the other end of the tunnel from each side.


INFO:

iodine has been tested on Linux (x86 and SPARC64) and OpenBSD (x86). It should
work on other unix-like systems as well that has TUN/TAP tunneling support. Let
us know if you get it to run on other platforms. 


THE NAME:

The name iodine was chosen since it starts with IOD (IP Over DNS) and since
iodine has atomic number 53, just like the DNS port.


AUTHORS & LICENSE:

Copyright (c) 2006 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.