Re: Yet another failure mode in pg_upgrade

On Sat, Sep  1, 2012 at 02:35:06PM -0400, Bruce Momjian wrote:
> On Sat, Sep  1, 2012 at 02:23:22PM -0400, Tom Lane wrote:
> > Bruce Momjian <bruce@momjian.us> writes:
> > > +     /*
> > > +      *    Report the Unix domain socket directory location to the postmaster.
> > > +      */
> >
> > "Report" seems entirely the wrong verb there.

Fixed.

> > > + #define LISTEN_STR    " -c listen_addresses=''"
> > > +
> > > +     /* Have a sockdir to use? */
> > > +     if (strlen(os_info.sockdir) != 0)
> > > +         snprintf(socket_string, sizeof(socket_string) - strlen(LISTEN_STR),
> > > +             " -c %s='%s'",
> > > +             (GET_MAJOR_VERSION(cluster->major_version) < 903) ?
> > > +                 "unix_socket_directory" : "unix_socket_directories",
> > > +             os_info.sockdir);
> > > +
> > > +     /* prevent TCP/IP connections */
> > > +     strcat(socket_string, LISTEN_STR);
> >
> > IMO this would be simpler and more readable if you got rid of the LISTEN_STR
> > #define and just included -c listen_addresses='' in the snprintf format
> > string.  The comment for the whole thing should be something like
> > "If we have a socket directory to use, command the postmaster to use it,
> > and disable TCP/IP connections altogether".
>
> Well, you only want the unix_socket* if sockdir is defined, but you want
> LISTEN_STR unconditionally, even if there is no sockdir.  Not sure how
> that could cleanly be in a single snprintf.

I restructured the code to add the listen_addresses string first,
allowing the removal of the #define, as Tom suggested.  I also added
unix_socket_permissions=0700 to further restrict socket access.

Updated patch attached.

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

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