Re: [Pdns-users] Re: Domains with binary (e.g. UTF-8) labels
bert.hubert at netherlabs.nl
Sun Dec 17 13:32:03 CET 2006
On Sun, Dec 17, 2006 at 12:48:08AM +0000, Julian Mehnle wrote:
> > It also requires some work on the database side of things, as for
> > example PostgreSQL is fond of interpreting 'VARCHARs' as UTF-8, which a
> > random label very often is not.
> I'm not sure I understand what you're saying here.
You want UTF-8. But it is stated nowhere that DNS should be UTF-8, there is
only an RFC that says DNS is '8 bit clear', although in practice it
isn't, which explains my relative lack of interest.
If the database thinks in UTF-8, but something comes along that isn't (hint,
many random 8-bit octet-strings are not valid UTF-8!), it refuses the data.
So the database needs to stop thinking and accept, and match, binary labels,
while remaining case insensitive!
Stephane hinted at that already. I don't see how this should work. If we
accept binary labels, we might match these when you don't expect them to.
For example, a binary label containing the letter 'b' will also be matched
by that same label containing the letter 'B', which might mean something
differently to you.
For UTF-8 content, it doesn't matter, but for other binary uses it might.
DNS does not accept 'abcde' and 'abcDe' as "brothers" in a zone, but from a
binary standpoint they are different.
I'm not going to work out these complications, this will be up to the people
that want 8-bit labels in PowerDNS. If I see a solution, I'll implement it,
but right now things look rather useless.
http://www.PowerDNS.com Open source, database driven DNS Software
http://netherlabs.nl Open and Closed source services
More information about the Pdns-dev