vrf support in FreeBSD

[Julian Elischer]

Ray Mihm wrote:

> Using ipfw tables is essentially a non-starter, IMHO. How would
> routing protocols use ipfw based tables, for example? Marko's work
> touches a lot of files, but I don't think it's heavy weight.
>
> I also think using Marko's idea and Jails would allow create the
> notion of a logical system and multiple such logical systems may be
> configured on a single FreeBSD system.
>
> Regards,
>
> Ray. 

Don't get me wrong.. I very much like vimage, and it is a great pitty 
that it
(in the form it is in now)
is basically incompatible in concept with freeBSD 5+  (where most things 
are modules)(*).

I've even done some small work on prototyping how one MIGHT be able to
make it happen, but for what I want (just be able to have some packets use
an alternative routing table), having ipfw fwd them according to a table 
does just fine.

(*) The problem is that moving all globals to a structure only works if 
you know what globals
are linked in.  If you load a module, you need to expand the structure. 
This is problematic
to say the least. The same problem has been solved with 
Thread-local-storage using hooks
in the compiler and linker but I don't think we can do that in the 
kernel. (at least not easily).