[Pdns-dev] [Pdns-users] Re: Domains with binary (e.g. UTF-8) labels

bert hubert bert.hubert at netherlabs.nl
Wed Dec 20 02:30:42 CET 2006

> Certainly (IDN was invented for a reason). The Web page
> http://cr.yp.to/djbdns/idn.html shows an awful ignorance of both
> Unicode and DNS.

I haven't visited that site yet, but will do so now :-)

> Dec 8 13:09:47 mastermind pdns[23171]: Received a malformed qdomain from X.Y.Z.T, 'SUIVI MATERIEL.local.fr': dropping
> Dec 8 13:09:50 mastermind pdns[23171]: Received a malformed qdomain from X.Y.Z.T, 'www;pajemploi.ursaff.fr': dropping
> Dec 8 13:10:09 mastermind pdns[15986]: Received a malformed qdomain from X.Y.Z.T, 'c??dric.local.fr': dropping
> So it seems that PowerDNS has trouble, not only with 8-bits characters
> but with legal DNS ASCII characters like the semicolon, as well.

PowerDNS only has *real* trouble right now with the | character in DNS, as
we use that internally. This could easily be fixed.

The rest is the result of some scary PostgreSQL messages at one point and
that we believed DNS was only supposed to contain [a-zA-Z0-9-_], a very
widely held belief. In fact, up to two weeks ago, I still thought this was
the case. Most people think so. 

So, to solve those PostgreSQL messages, we decided to disallow any and all
queries with characters outside the range [a-zA-Z0-9-_], which we thought
was ok.

The PostgreSQL messages in turn were caused by it interpreting random
queries as UTF-8, but we decided not to really tackle that issue because we
thought those queries were illegal anyhow, and could safely be dropped.

So now you know ;-) 

We'll work on both issues - the '|' thing needs to go anyhow. I'm unsure
however if we'll find a way to get databases to be both case-insensitive and
not care about what looks like UTF-8, but isn't.


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