From: Bruce Momjian <bruce@momjian.us>
Message-Id: <201106140058.p5E0w3F07048@momjian.us>
Subject: Re: CIDR address in pg_hba.conf
In-Reply-To: <BANLkTimx-SYy-6GbQcxM5ZAemyj2pA8mzg@mail.gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Date: Mon, 13 Jun 2011 20:58:03 -0400 (EDT)
CC: Tom Lane <tgl@sss.pgh.pa.us>, Fujii Masao <masao.fujii@gmail.com>,
	pgsql-docs <pgsql-docs@postgresql.org>
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Robert Haas wrote:
> On Thu, Jun 9, 2011 at 8:42 PM, Bruce Momjian <bruce@momjian.us> wrote:
> > Tom Lane wrote:
> >> Fujii Masao <masao.fujii@gmail.com> writes:
> >> > http://developer.postgresql.org/pgdocs/postgres/auth-pg-hba-conf.html
> >> >> An IP address is specified in standard dotted decimal notation with
> >> >> a CIDR mask length. The mask length indicates the number of
> >> >> high-order bits of the client IP address that must match. Bits to the
> >> >> right of this must be zero in the given IP address.
> >>
> >> > Is the last statement correct? When I specified the following setting
> >> > in pg_hba.conf, I could not find any problem in PostgreSQL.
> >>
> >> > ? ? host ?all ?all ?192.168.1.99/24 ?trust
> >>
> >> > As far as I read the code, those bits seem not to need to be zero.
> >> > Attached patch just removes that statement.
> >>
> >> Even if it happens to work that way at the moment, do we want to
> >> encourage people to depend on such an implementation artifact?
> >>
> >> IOW, if you read "must" as "if you want to trust it to work in future
> >> versions, you must", the advice is perfectly sound.
> >
> > Should we use "should"?
> 
> +1.

Thanks for the feedback.  Patched in head and 9.1.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +