Return-icmp doesn't work [Was: Re: Recent panics caused by pf]

[Daniel Hartmeier]

On Fri, Mar 11, 2005 at 01:50:47PM +0100, Emanuel Strobl wrote:

> > Then I have another problem which may be a design problem.
> > I am multihomed and have several pass reply-to rules. So far things are
> > working fine but block return doesn't! Of course, the return gets over the
> > default route, so what I needed is a block return route-to or something
> > like that.
> > Do you know any detour how this could be achieved?
> 
> This problem is still unsolved :(

The idea is that you can use reply-to on block rules for this purpose:

  block return-rst in on wi0 reply-to (wi0 10.1.1.1) inet proto tcp all

This is valid syntax and pfctl loads the rule, but the functionality is
not implemented in kernel yet, i.e. the reply-to option is simply
ignored.

The problem is that return-icmp uses the stack's icmp_error(), which
doesn't take an argument to override a route lookup. And duplicating the
function would be ugly due to its size. It's on the to-do list, but it's
been sitting there for a while already.

Daniel