Subject: nul interface?
To: None <>
From: Andrew Brown <>
List: tech-net
Date: 10/24/2001 21:41:42
i was thinking that having a nul network interface might be useful for
some purposes.  at the very least, all the reject routes that get
installed could be changed to dump traffic out a nul interface
instead, which might make visual inspection of the routing table easier.

i made one a while back, and while i don't have the code any more, i
seem to recall it being not much more than a pseudo-device (just like
lo), and a copy of net/if_loop.c with the names all changed to
nulfoo()) instead of lofoo().  the one difference was the nuloutput()
routine which turned into something like this:

	nuloutput(ifp, m, dst, rt)
		struct ifnet *ifp;
		struct mbuf *m;
		struct sockaddr *dst;
		struct rtentry *rt;


		return (0);

so that all traffic that went that way would just disappear.

how many people think this is a silly idea?

|-----< "CODE WARRIOR" >-----|             * "ah!  i see you have the internet (Andrew Brown)                that goes *ping*!"       * "information is power -- share the wealth."