[Dibbler] Dynamic DNS (FQDN) support

[Tomasz Mrugalski]

Hi,

Just wanted to post some informations about Dynamic DNS support in 
dibbler. As pointed out by Karl Auer, it is rather essential to support 
DNS Updates on the server side. So this was the main area of development.
(Krzysiek Wnuk actively participating in the DDNS development. Thanks!)

Note that this is not a stable release, just a mere development snapshot. 
It can be downloaded from: http://klub.com.pl/dhcpv6/snapshots/

This version is able to:
- server can maintain list of available names. None, some or all names can
   be reserved. Reservations can be both address based as well as duid
   based.
- server can be configured to execute:
   *  both updates (forward resolving - AAAA record, reverse resolving -
      PTR record)
   * only reverse resolving (PTR)
   * don't perform updates at all
- client is able to execute only forward resolving if it is allowed to do
   so by the server
- client can just ask for its fully qualified domain name
- client can ask for its name by providing a hint

It was tested with BIND 9.3 running on Linux box.

Note that there are several limitations:
  - reverse updates does not work properly, so they are disabled (if you
    want to enable and test them, take a look at IfaceMgr/DNSUpdate.cpp)
  - after releasing addresses/client shutdown, cleaning up DNS Update is
    not performed
  - due to bug in the server, currently client must provide hint (it will
    be ignore anyway, but asking for FQDN using OptionRequest is not yet
    supported) so use "option fqdn foo.bar" instead of just "option fqdn"
    in the client.conf

I have also started process of the documentation update/rewrite. It is 
messy right now, but there are several Dynamic DNS-related informations 
available.

Of course, all those goods are present in the CVS, too. This version also 
supports temporary addresses, but this feature seems to be low importance.
Several small annoyances were fixed. See CHANGELOG for details. 
Currently Linux binaries and source archive is available. Windows 
snapshot might be built in few days, if there is a need for this.

Ok, time to sleep. It's 2:50am in Poland. It will be short night...

Cheers,
-- 
Tomasz Mrugalski,              | " Talk is cheap. Show me the code."  |
thomson(at)klub(dot)com(dot)pl |                     Linus Torvalds   |