Bug#373758: [Pkg-cups-devel] Bug#373758: Debian testing instalation & Debian reference problem in /etc/hosts

[Henrique de Moraes Holschuh]

On Thu, 15 Jun 2006, Roger Leigh wrote:
> > The answer to the problem has been to rewrite my /etc/hosts
> > so that it reads:
> >
> > 127.0.0.1 paag localhost

This is dangerous, will "break" (arguably already broken software) like
CUPS, and it is not a fix to the real bug anyway.  You can safely use
'127.0.0.1 localhost paag' though, but I don't know if it would work as a
workaround for CUPS.

> It's failing because the reverse hostname lookup failed.  This might
> indicate a DNS issue on your network.  Does your DNS do PTR lookups?

What it does indicate is a bug in Debian's config (unless the user modified
the config files, that is).  First of all, CUPS should not be doing any
reverse lookups by default.

Also, we should bind CUPS to the right interface and use the right ACLs by
default, i.e.  always match on 127.0.0.0/8 for IPv4 localhost, and also ::1
and fe00::0 for IPv6 (AFAIK, someone who really knows IPv6 please correct me
if I got it wrong) anywhere we mean 'localhost'.

> These affect the CUPS name lookup behaviour.  It does special case
> localhost in some circumstances, which caused the above bug.

Special-casing localhost is almost always a bug by itself, and of a
particular nasty, insiduous, and usually extremely stupid class at that.

Time to fix CUPS if it has any sort of special casing based on the
'localhost' string or 127.0.0.1 dotted-quad (or ::1 for that matter), I'd
say.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh