Reverse Path Filtering check in ip_input.c

[Yann Berthier]

On Tue, 03 Jan 2006, at 14:58, ?ukasz Bromirski wrote:

> Yann Berthier wrote:
> 
> >    If this yet to be found wiser guy would not forget the loose check
> >    too (verrevpath in ipfw speaking), where packets matching the default
> >    route are ok ... :)
> 
> Actually it does that and will until we'll have option to have two
> or more default routes.
> 
> Presently, if packets comes via interface and reply for it should be
> sent on the same interface (because default route points to it and
> there are no other routes pointing for the same destination to
> another interface) it will work.
> 
> Check fails if there's either interface mismatch, or source is present
> in routing table but marked as RTF_REJECT/BLACKHOLE one.

   My bad, i didn't looked at your patch, I was misleaded by the
   verrevpath / versrcreach description.

> OpenBSD imported KAME mroute extension that enables them to have
> more than one route for given destination simultaneously in routing
> table. I'm looking into it now, as it's very attractive thing,
> however as Andre is doing rework of network code I'm sure we'll have
> it sooner or later and then maybe someone will revise old checks
> already marked as 'XXX' in the code ;)

   Amen

      - yann