resolv_wrapper URI RR support - name compression

[Andreas Schneider]

On Tuesday, 23 August 2016 11:41:45 CEST Matt Rogers wrote:
> On Tue, 2016-08-23 at 15:54 +0200, Andreas Schneider wrote:
> > On Monday, 22 August 2016 17:52:25 CEST Matt Rogers wrote:
> > > Hi,
> > > 
> > > I'm using resolv_wrapper from master at 02535da4 to test krb5 URI
> > > RR
> > > lookups. Similar to the SRV records, rwrap_fake_uri() runs
> > > ns_name_compress() on the result, however URI records contain a
> > > formatted entry and not a DNS name, so I don't think that the call
> > > to
> > > ns_name_compress() is valid here.  The result of running
> > > ns_name_compress() on the URI record (which appears as
> > > "krb5srv:m:kkdcp:https://kdc/path") is that it adds a " " to the
> > > beginning that does not get removed with a subsequent uncompress.
> > > Any
> > > objections to removing the ns_name_compress/uncompress on URI RR
> > > results?
> > 
> > This means the provided test is incorrect. We need a test which works
> > in a 
> > real world scenario and also with resolv_wrapper to verify that
> > resolv_wrapper 
> > is doing everything correctly.
> > 
> > Could you use the current test, modify it and make sure it works in
> > the real 
> > world?
> > 
> > Then we can fix resolve_wrapper ...
> 
> I've attached patches for removing the name compression from the URI
> result as well as the tests. This gives a correct result for the real
> world test.

Hey Matt,

thanks for the patches!

Please add:

size_t uri_len;

uri_len = strlen(rr->rrdata.uri_rec.uri) + 1;

and then use uri_len as we are using it twice.

Also you need to sign your work. See

https://www.samba.org/samba/devel/copyright-policy.html

> Another issue is that it can only return a single answer for a URI
> query, since it reaches the first matching URI key in the host file and
> stops. The krb5 URI lookup collects all answers from a query and parses
> the URIs, sorting the results accordingly, so it would be great to be
> able to have a fake hosts file with all of the test URIs listed and not
> have to test them one by one.

We are happy to accept patches to allow to return more than one URI :)


Best regards,


	-- andreas

-- 
Andreas Schneider                   GPG-ID: CC014E3D
Samba Team                             asn at samba.org
www.samba.org