lzma with TCP/IP and libertas driver... and still some room

[Andres Salomon]

On Wed, 2006-10-04 at 11:48 -0400, Dan Williams wrote:
> On Wed, 2006-10-04 at 10:26 -0400, Jim Gettys wrote:
> > Yeah, and the other headache in IPv4 is lack of autoconfiguration: you
> > need a dhcp server for two machines to talk to each other.  If we want
> > to clone systems from nearby kids, this then means a dhcp server, and
> > all that rot.
> 
> What about self-assigned IP4 addresses?  That's pretty standard in all 3
> major OSes, and there's a well-defined process to come up with one.  You
> essentially pick an address at random from the 169.xxx.xxx.xxx range,
> and send out some packets to see if anyone else has it.  If somebody
> does, you pick a new address and repeat.
> 
> We're already going to ship Avahi for userspace, and it can do this just
> fine.  For the BIOS side of things, this should be trivial to implement
> as the state machine is quite simple.

I took a peek at avahi's source, and I have a few questions/issues:

ARP is used to determine whether an IP is in use.  That means any IP
addresses that aren't on the local link but are routable may conflict w/
the chosen IP.  Will that be a problem?

It looks like it uses rand() to get an IP address, seeded
from /dev/urandom and time().  rfc3927 describes (in section 2.1) using
the MAC address to seed its PRNG.  Does LB make /dev/urandom available?
Do we even want to consider using that?  Why not use the MAC address?

How long would we be waiting for an ARP probe to timeout?