Communication driver framework ?

[Sifalakis, Manolis]

Hello all,

I am new to the list as well as "under the FreeBSD-hood" and this is my 
first posting so pls forgive me if this has been asked 1000 times before 
(I did not manage to find it in the archive).

We re planning to implement a programmable router framework for FreeBSD, 
and basically we need to have a piece of code between the NIC driver(s) 
and the protocol stack to pull out and push (back) in the forwarding 
path network packets (and possibly do some low level routing among the 
NIC interfaces there).

As a result I would like to ask if there is a communications driver 
framework similar to NDIS -bleah- (in M$ Win) or STREAMS (in the -early- 
ATT unix flavors), in FreeBSD. It would be significantly more efficient 
and portable if we did not have to hard code in the kernel our 
"intermediate" driver.

Thanks in advance for reading ... even more for replying ;)

-- Manolis.