[systemd-devel] systemd-resolved as dnsmasq replacement

[Lennart Poettering]

On Thu, 18.06.15 07:57, Daurnimator (quae at daurnimator.com) wrote:

> On 18 Jun 2015 3:51 am, "Lennart Poettering" <lennart at poettering.net> wrote:
> >
> > On Wed, 17.06.15 19:48, Igor Bukanov (igor at mir2.org) wrote:
> >
> > > On 17 June 2015 at 15:27, Lennart Poettering <lennart at poettering.net>
> wrote:
> > > > To hook up local name service
> > > > clients people should use the "nss-resolve" NSS module, which ensures
> > > > that gethostbyname() and friends use resolved as backend.
> > >
> > > I suppose then non-glibc clients should deal with that on its own. I
> > > thought converting LLMNR into DNS would be a reasonable hack, but then
> > > if the translation requires too much insanity, then indeed it is
> > > better not to do that.
> >
> > If people use libraries to do DNS manually, then they'll do *DNS*
> > manually, and we shouldn't interfere with that really.
> >
> > Usually people pick non-libc DNS libraries because they need async
> > behaviour. I am pretty sure that's a pretty bad reason though and if
> > you want async behaviour you should use sd-resolve or so.
> 
> I've also used them because I
>   - need other record types (e.g. SRV)

res_query() can do that too, as part of libc.

The bus API of resolved allows queriying that. But of course, we don't
advertise that yet, and haven't even declared it stable.

>   - want to use DNSSEC

It is our intention to add this to resolved soon.

>   - Want to choose between recursive and stub resolvers

I am pretty sure recursive resolvers should be left to DNS servers. If
all clients would start doing that, the whole caching scheme of DNS
would be pointless...

> FWIW, I use http://25thandclement.com/~william/projects/dns.c.html in many
> projects.
> It parses nsswitch.conf, but only cares about a few predetermined values.
> Maybe it should gain some features in this area?

I am not a fan of people doing things like that. In the long run I am
pretty sure people should ask resolved. In the short run people should
use libc's res_query() interface...

Lennart

-- 
Lennart Poettering, Red Hat