On Fri, Nov 01, 2019 at 09:45:37PM +0100, Florian Obser wrote:
> On Fri, Nov 01, 2019 at 09:35:07PM +0100, Remi Locherer wrote:
> > On Thu, Oct 31, 2019 at 08:14:04PM +0100, Otto Moerbeek wrote:
> > > Hi,
> > >
> > > So here's a new diff that incorporates the bug fix mentioned plus
> > > debug printf line changes suggested by Stuart.
> > >
> > > Please note that this is a diff on top of very recent current, i.e.
> > > florian's work he committed today. That means that you need to be
> > > up-to-date (including a recent libc update that was committed a few
> > > days ago) to be able to test this version.
> >
> > I upgraded to a snapshot from today, updated the source and applied
> > your diff. Then I did the same test as last time using pf to block port 53
> > (block return out log inet proto {tcp udp} to !9.9.9.9 port 53).
> >
> > Result: the non functional type asr is selected instead of the forwarder.
> >
> > $ doas unwindctl status
> > captive portal is unknown
> >
> > selected type status
> > recursor dead
> > forwarder validating (OppDoT)
> > dhcp unknown (OppDoT)
> > * asr dead
> > $
> > $ getent hosts undeadly.org
> > $ echo $?
> > 2
> > $ dig +short undeadly.org @9.9.9.9
> > 94.142.241.173
> > $
> >
> > Without your patch unwind behaves similar regarding the type selection:
> >
> > $ doas unwindctl status
> > captive portal is unknown
>
> ^ you are creating a not supported configuration.
>
> When we are behind a captive portal or don't know yet if we are behind
> a captive portal resolving is forced to asr.
>
> That might not be very wise if asr is dead but I currently don't see
> how this can happen in practice except with a well aimed foot-gun.
Actually, I have an idea how this can happen in practice, please try this:
diff --git resolver.c resolver.c
index f59860a5e98..5bbc63f60fa 100644
--- resolver.c
+++ resolver.c
@@ -1282,7 +1282,8 @@ best_resolver(void)
if (captive_portal_state == PORTAL_UNKNOWN || captive_portal_state ==
BEHIND) {
- if (resolvers[UW_RES_ASR] != NULL) {
+ if (resolvers[UW_RES_ASR] != NULL && resolvers[UW_RES_ASR]->
+ state != DEAD) {
res = resolvers[UW_RES_ASR];
goto out;
}
>
> >
> > selected type status
> > recursor dead
> > forwarder validating
> > dhcp dead
> > * asr dead
> > $
> >
>
> --
> I'm not entirely sure you are real.
>
--
I'm not entirely sure you are real.
