Re: Checking pg_hba.conf in the child process

On Fri, Feb 24, 2012 at 07:27:06PM -0300, Alvaro Herrera wrote:
> 
> Excerpts from Bruce Momjian's message of vie feb 24 19:19:10 -0300 2012:
> > In looking over our authentication code, I noticed that we create the
> > child process before we check any of the pg_hba.conf file.  Now, I
> > realize we can't do authentication in the postmaster because of possible
> > delay, and checking the user name and database name filters is just work
> > that is better done in the child, but checking the IP address might
> > prevent unauthorized clients from causing excessive process creation on
> > the server.  I know we have listen_addresses, but that defaults to "*"
> > on the click-through installers, and not everybody knows how to set up a
> > firewall.
> 
> Hm, one thing to keep in mind is that we allow hostnames there.  It'd be
> a pain to have postmaster hang while resolving names.

Yes, we would still need to recheck the filter in the child because of
username/dbname limits, but your point is very valid --- any use of
hostnames in pg_hba.conf would prevent us from doing IP checks.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +