cvs commit: src/sys/netgraph ng_pppoe.c

[Bjoern A. Zeeb]

On Thu, 26 Jan 2006, Gleb Smirnoff wrote:

Hi,

some brain-dump...

> The other change I'm planning to do is the following - if the
> original PADI had empty Service-Name, and we are servicing a
> specific Service-Name, then return remove empty one from PADO,
> returning only our specific Service-Name.

Why would you want that? I haven't re-read the RFC but I think it said
that PADOs have to include the Service-Name the client requested first,
optionally followed by other Services-Names the AC may want to
announce.

Only in PADS you will then reply with only the one Name you accepted.

I can see the problem with your change and the above coming:
What would happen if you
 	a) accepted the 'any service' request
 	b) replied with 'any service' and 'service-name1, ...'
 	c) the client now requests 'any service'
 	d) you don't want to serve 'any service'

Well you should have been silent from a) to b) *ups*

Ok, so the only solution to this problem is what should also be in
that RFC - it's a ploicy decicion of the AC -- of what to accept
as Service-Name in a PADI. We had a clear policy up to now name it
closed system. With your change we will have an open system (everyone
will see the Service-Names we may serve if requested).

The first thing might be a sysctl to toggle old and new behavior but
actually one may also want to decide on a peer by peer base depending
on a lookup perhaps based on mac address and/or Service-Name requested
or even simpler on a per ("Ethernet") port base and fall back to
a default poilcy if there is nothing (no hook) to do such a lookup.
[ I am () ethernet because it's not always a physical ethernet port
   at the other end at the AC ]


The other question is what to do with clients requesting Service-Names
we don't know of but we know that we should serve the client?
I think this is a common scenario here in DE that some clients set a
Service-Name to "foo" and the ACs silently ignore and just serves it
(server all Service-Names policy)[1].  It's also a policy decision that
people might need ...

[1] There are people speculating what will happen if they need to make
use of service-names ... ;) Fun with nnK users ...

-- 
Bjoern A. Zeeb				bzeeb at Zabbadoz dot NeT