On Mon, 2009-11-30 at 13:45 +0100, KOVACS Krisztian wrote:

Hi,

No, because by narrowing the rule to specific ingress interfaces the
lookup done in fib_validate_source() won't match the rule(s) (because
the flow used will have iif set to the loopback device), and thus it
will look up the main table and select a unicast route.

ok, nice;->

I don't think it would be unreasonable to add a sysctl but disable the
feature by default. It's up to you, of course.

The problem is it is hard to decide where the proper exception is to be
made. I can make it only worry about the scenario you are faced with
something like attached (incomplete, uncompiled, untested) patch. Will
that do it or can you think of other scenarios where source validation
is done and this is needed (example forwarding path)? Patrick?
[I could move the check into fib_validate, but that would punish other
users with a few extra cycles]. 

cheers,
jamal