small tun(4) improvement

[Andre Oppermann]

Julian Elischer wrote:
> 
> Andre Oppermann wrote:
> >
> >P.S. I'm working on making protocols within protocols domains loadable at
> >least for IPv4.
> >
> I did some work on this once.. things have got a lot more complicated
> however with locking..

Actually there are not that many locking problems with the register and
unregister functions themselfes.  It get a little bit more trickier with
the stuff using these hooks though.

> >I'm using this to make DIVERT a loadable module.
> >
> cool.. the trick is to work out how to make it (un)attach to ipfw..

DIVERT sockets in themselfes do not depend on ipfw.  You can send out
packets just fine through a diver socket even when ipfw is missing.
But you can't get any packets from the kernel unless ipfw puts them
up to divert.  Nothing that prevents other uses or users of divert
in the end (ng_divert perhaps...).

-- 
Andre