On Tue, Jul 25, 2017 at 02:58:29PM -0400, Roland C. Dowdeswell wrote:
> On Tue, Jul 25, 2017 at 08:45:44AM -0700, Russ Allbery wrote:
> > Eh? I *absolutely* would expect that and would consider it a bug if it
> > did not. It is incredibly useful for testing to be able to temporarily
> > override the IP address of a host in /etc/hosts, and I expect all software
> > to honor that.
> SRV RRs are essentially a generalisation of CNAMEs or perhaps MX records.
We can also say SRV are a more elegant expression of the main DNS
purpose: to map service names to endpoints.
(This was historically inconsistently done by static allocation of service
port numbers combined with collective naming of _sets_ of services aka
hostnames, the result complemented by the regrettably incomplete solutions
like MX and AFSDB. Thus, SRV RRs are a great step forward.)
> It is counter-intuitive to expect that /etc/hosts will interpose in the
> middle of a lookup.
I second Russ and do not agree with you on this point.
Given that SRV records as a matter of fact are defined via A[AAA] records,
(and given that A lookups historically _are_ interposed by /etc/hosts)
what says that /etc/hosts are to be ignored if an A lookup happens as
a consequence of an SRV one?
> As you can see, getaddrinfo(3) will only use DNS to chase the CNAME
> defined in DNS and does not consult /etc/hosts in the middle of a
You refer to a certain implementation which is not a specification
by itself. What do the applicable standards say?