Subject: Re: your recent ARP changes...
To: None <>
From: Ignatios Souvatzis <>
List: tech-net
Date: 04/21/1997 21:18:51

the problem is not that we couldn't create a struct arpcom in a backwards
compat include file just to have one...

the problem is that drivers could think, as about 100 or so (which I
transformed) did, that it contains an Ethernet address copy, and
operate on it. (e.g., assume that all system components will look at
it, etc.)

They should use LLINFO(ifp->if_ladr) instead, of course, if ported to

That is: either we add that field to the compat_arpcom structure,
making the software fail at runtime, or we don't add it, making the
software fail at compile time. We have the latter already... 

If anybody has a suggestion how to handle this, please speak up.

We could make an netinet/if_ether.h, which

- #includes <net/if_ether.h>
- #defines ac_if ec_if, or does this through a fake arpcom definition.

- contains a struct arpcom which encapsulates struct ifnet

what did I forget?

This won't work with real ethernet devices, however; they need to be
ported (and should be).

Btw: maybe its easier to write a compat module the other way round?