dhcp server - some patches

[Alan DeKok]

Haralds Ulmanis wrote:
> Second one ... patches for updating reply->code correctly depending on modules 
> answer(last DHCP-Message-Type update will be in action). Actualy client 
> must!!! supply in some update section DHCP-Message-Type. 
> Otherwise i think no reply at all(not tested) :) .

  The idea is that in *normal* circumstances, the server just Does the
Right Thing.  If it receives a discover, and the policy returns "ok",
then the response should be an offer.

> And i think there no need to respond with NAK in reject, fail and other cases 
> (and DECLINE response is client side only). There is no need for that garbage 
> traffic. If module fails then fails. NAK message to client will not help in 
> this case :) Or maybe i don't want to respond at all (ignore) :)

  In some cases, the server needs to send an explicit NAK, in order to
force the client to re-broadcast a discover.

  I've committed a change that lets the policy set the message type.

  Alan DeKok.