Re: per-FIB socket binding

Paul Vixie <paul@redbarn.org> wrote:

> i've been thinking along these lines for a few years now, since my vm server is multi-fib. 
> each interface has a fib, mostly zero. for incoming TCP SYNs, i'd like to carry that fib# into 
> the resulting PCB so that that fib's routing table and especially its default route will be 
> used for that connection. yes, i can do that with ipfw, and am in fact doing so now. 
> however, that's crocky. i think defaulting to the interface FIB for connections created and 
> maintained by the kernel should always happen -- not opt-in, not opt-out, just always. is 
> it worth me sending a patch that does this or would it be considered controversial?

I like that. I isolate 5 seperate networks by assigning a fib to each interface, and was
initially surprised that I had to jump through ipfw hoops to get it to work properly, in
fact at the end of my ipfw rules for these interfaces, just to guarantee no leaking,
I have this, out of kludgy desperation! :

05111 deny log ip from any to any fib 1 not via em1
05112 deny log ip from any to any fib 2 not via em2
05113 deny log ip from any to any fib 3 not via em3
05114 deny log ip from any to any fib 4 not via em4
05115 deny log ip from any to any fib 5 not via em5

So, yes, I agree that it's crocky, and your proposal is how I originally expected it to
work, and indeed, I can so no reason for it not to work that way, but am prepared to
be enlightened if anyone else has an opinion on this.

Jamie