[Click] DSDV implementation

[Michael Voorhaen]

Hi,

Thanks again for helping me getting everything compiled, I've booked
serious progress on the implementation of my protocol. There's still a lot
of work to be done and I'm sure that, since this the first time I'm
implementing a routing protocol, there will be plenty of mistakes still
left to correct.

Anyways like I said before I very much want DSDV to run beneath my
hierarchical routing protocol. I however misjudged the impact of my
hierarchical protocol on DSDV and I had to make some alterations, mainly
to make sure that nodes choose the correct gateway etc and to make sure
that routing information is only spread among nodes that belong to the
same 'subnet'. I'm looking into getting this functionality into another
Element, but for now this should do.

One of the things that I did is make sure that when a host changes gateway
it starts routing packets to other subnets using the gateway. So when the
destination is in the previous subnet,  the packets are delivered through
the backbone (this is pretty strict, i'm planning on allowing
communications between subnets not using the gateway if it only consists
of a small nr of hops).

And now for the actual question. If a node moves to another subnet, and it
is receiving packets these will still come through the old subnet. I
don't really mind that, but after a wile I do want the routes to expire
and the nodes on the previous subnet should also start communicating
through the backbone. This should cause less overhead and packetloss than
having to notify the other nodes of the subnet.
I put some debug statements in expire_hook and  monitored when the route
expires. When I don't send any packets the route expires like it should,
but if the node originates packets the entry doesn't expire. I don't see
any references in lookup_route that update the expire timer or am I
missing something? The nodes on the previous subnet should ignore the
route information from the other subnet, so in their eyes they don't get
any info on the destination anymore.

Thanks in advance.

Regards,
Michael