To: krb5-bugs@MIT.EDU
Subject: SRV record support
From: Ken Raeburn <raeburn@MIT.EDU>
Date: Fri, 14 Mar 2003 19:07:10 -0500

The RFC says a SRV record can have a target name of ".", meaning
"service not available".  We don't handle that case.

I think (but can't quite confirm, yet) that the target name is
supposed to be a complete name.  So if a hostname is returned without
a trailing ".", we might want to add one before looking it up.

Ken

To: rt@krbdev.mit.edu
Subject: Re: [krbdev.mit.edu #1383] SRV record support
From: Tom Yu <tlyu@mit.edu>
Date: Fri, 14 Mar 2003 19:45:43 -0500
RT-Send-Cc: 

>>>>> "Ken" == Ken Raeburn via RT <rt-comment@krbdev.mit.edu> writes:

Ken> I think (but can't quite confirm, yet) that the target name is
Ken> supposed to be a complete name.  So if a hostname is returned without
Ken> a trailing ".", we might want to add one before looking it up.

RFC 1035 says that a <domain-name> is terminated with a zero-length
label, which seems to indicate that the target name is absolute.

RFC 1034 also indicates that relative names are mostly a user
interface thing.

---Tom

To: rt@krbdev.mit.edu
Subject: Re: [krbdev.mit.edu #1383] SRV record support
From: Tom Yu <tlyu@mit.edu>
Date: Thu, 07 Oct 2004 18:48:26 -0400
RT-Send-Cc: 

>>>>> "Ken" == Ken Raeburn via RT <rt-comment@krbdev.mit.edu> writes:

Ken> I think (but can't quite confirm, yet) that the target name is
Ken> supposed to be a complete name.  So if a hostname is returned without
Ken> a trailing ".", we might want to add one before looking it up.

I checked a little bit of the source code of dn_expand() and
ns_name_uncompress(), and neither returns a trailing dot unless the
root domain is what's being expanded.  Even though a SRV record is
supposed to have a complete domain name as the target, and would
logically be represented with a trailing dot, the resolver API doesn't
show us the trailing dot.  This means that we'll have to explicitly
append a trailing dot so that further lookups will bypass the local
domain search.

---Tom

Trailing "." appended already in lib/krb5/os/dnssrv.c:5.7.  Closing.