udns returns DNS_E_NXDOMAIN when domain exists but SRV records does not exist

[mjt at corpit.ru]

20.06.2011 19:25, Iñaki Baz Castillo wrote:
> Hi, the domain kamailio.org does exist and has a DNS A record
> associated (193.22.119.66). But it has no SRV records.
> 
> Then using udns I query SRV for _sip._udp.kamailio.org, which means
> service=sip, protocol=udp and domain=kamailio.org.
> 
> udns replies DNS_E_NXDOMAIN. This is incorrect, as the domain is not
> the whole "_sip._udp.kamailio.org" but just "kamailio.org". The prefix
> "_sip._udp" is just a way to tell the DNS which kind of SRV record we
> want. In fact, "_" is not allowed in a real domain.
> 
> So udns should reply DNS_E_NODATA rather than DNS_E_NXDOMAIN.

This is exactly backwards.  From DNS viewpoint, whole
_sip._udp.kamailio.org is a regular domain name, it is not
the same as kamailio.org.  Returning something other than NXDOMAIN
in this case is wrong.

/mjt