Re: lib/50367: libc resolver library does not resolve host names with underscores ("_")

[Robert Elz <kre%munnari.OZ.AU@localhost>]

The following reply was made to PR lib/50367; it has been noted by GNATS.

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: Brett Lymn <blymn%internode.on.net@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, lib-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Subject: Re: lib/50367: libc resolver library does not resolve host names with underscores ("_")
Date: Sun, 25 Oct 2015 11:36:52 +0700

     Date:        Sun, 25 Oct 2015 14:13:11 +1030
     From:        Brett Lymn <blymn%internode.on.net@localhost>
     Message-ID:  <20151025034311.GA1222%internode.on.net@localhost>
 
   | That is actually the correct behaviour, underscores are not legal in
   | hostnames.
 
 That's correct, for hostnames being entered into hostnames.txt (a file
 that hasn't existed in any meaningful form for 30 years.)
 
 There are no constraints on names that can appear in the DNS (only a
 recommendation on what was good to use, in the mid 80's, for compat
 with old software), and hence there should be no constraints on what
 can be resolved (just adding '_' to a magic list of acceptable chars
 is wrong.)
 
 e-mail domain names are a whole other issue of course, similarly names
 used with other protocols that might have various limitations, and as are
 the set of chars that NetBSD (or any other OS) permits for the
 sethostname(2) syscall.
 
 kre