In some mail from Noriyuki Soda, sie said:
> 
> >>>>> On Wed, 14 May 2003 14:01:54 +0900 (JST),
> 	Curt Sampson <cjs@cynic.net> said:
> 
> >> i don't think that ipfilter and tcpdump should use the same mechanism
> >> to solve this "problem".
> 
> > Why not?
> 
> Well, adding a protocol specific member to a protocol independent
> structure (== struct ifnet) definitely sounds wrong.
> So, it's desirable to avoid it, if there is a way...

While it's good and well to say this, lets look at the reality of the
situation.  If you go through "struct ifnet" you will find a number of
fields or bits defined for things that are explicitly related to IP.
So to bring up that sort of argument at this point in the history of
IP in the BSD kernel is really a bit late.  Technically, you are correct
but practically, I do not think this is a major concern.

Darren