Re: Patch to make postmaster bind to only to localhost.

I'm kinda in agreement with John on this, it does add a level of security
from DOS attacks ... I would have prefer'd the patch being something that
attaches it to a specific IP though, vs just 127.0.0.1 ... I think that
would be slightly more useful ... John, any chance of resubmitting it with
that feature added to it?

On Tue, 12 Sep 2000, Bruce Momjian wrote:

> Well, we do reject quite early. For example, we do not start a backend
> to check if the connection should be received, so it seems like we a
> really are not open to any more DOS attack than telnetd or other
> servers. Is that a fair statement? I would need to hear someone else
> who feels strongly about this before adding additional options to the
> postmaster.
>
>
>
>
> > Bruce,
> >
> > I might agree accept for the following. By the time the pg_hba.conf
> > file is checked the connection is already accepted, then rejected
> > by the rule. A outsider could easlily over-load the postmaster by
> > making repeated connections.
> >
> > Also with a port scan a outside cracker can get a small peice of
> > information about what is running on your system. The less information
> > a cracker has the beter.
> >
> > With this patch both of these situitations would not be possible.
> >
> > Would you be more open to a more general, but more complex, patch that
> > would allow you to select the IP's that you bind to. This would allow
> > one to configure a system where the localhost, and an internal interface
> > are bound, but the external interface to the internet is not.
> >
> > Thanks,
> >
> > John C. Quillan
> > >
> > > I am inclinded to skip this patch. We already have too many postmaster
> > > options, and I don't think adding something that already is done in
> > > pg_hba.conf is a big help. Sorry.
> > >
> > > > All,
> > > >
> > > > The company I work, DataSoft, for is doing a web based project
> > > > that uses Java and the JDBC driver for postgres. Aperently the
> > > > developers have told me that the JDBC requires the -i option on
> > > > postmaster. The only problem is this leves a visibility to the
> > > > outside world that we are using postmaster, or some other service.
> > > > Now we do have the pg_hba.conf configured to allow connections
> > > > from only that box it self, but you can never be two parinoid.
> > > >
> > > > The patch that is attached adds a "-L" option to postmaster, which
> > > > tells postmaster to bind only to 127.0.0.1 or localhost. Now this
> > > > port is not exposed to the outside world, ie port scanners can't
> > > > detect it, and we can run our Java code with a little more comfort.
> > > >
> > > > The patch is against the postgresql-7.0.2 source tree.
> > > >
> > > > The patch was minimally test under Linux kernel 2.2.5 using
> > > > a RedHat 6.0 distribution.
> > > >
> > > > The files effected are
> > > > postgresql-7.0.2/src/backend/libpq/pqcomm.c
> > > > postgresql-7.0.2/src/include/libpq/libpq.h
> > > > postgresql-7.0.2/src/backend/postmaster/postmaster.c
> > > >
> > > > The patch just addes the -L option with a bool flag variable
> > > > BindLocalOnly to postmaster.c
> > > >
> > > > Also the StreamServerPort function was modified to tha an extra
> > > > bool arguement which then if true causes the socket to be bound
> > > > to INADDR_LOOPBACK instead of INADDR_ANY.
> > > >
> > > > The patch is just a tar.gz file that extracts over the postgresql-7.0.2
> > > > source tree.
> > > >
> > > > If there are any issues pleas let me know.
> > > >
> > > > Thanks,
> > > >
> > > > John C. Quillan
> > > > john_quillan(at)datasoft(dot)com
> > >
> > > [ application/x-gzip is not supported, skipping... ]
> > >
> > > --
> > > Bruce Momjian | http://candle.pha.pa.us
> > > pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
> > > + If your life is a hard drive, | 830 Blythe Avenue
> > > + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
> >
>
>
> --
> Bruce Momjian | http://candle.pha.pa.us
> pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
> + If your life is a hard drive, | 830 Blythe Avenue
> + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
>

Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy
Systems Administrator @ hub.org
primary: scrappy(at)hub(dot)org secondary: scrappy(at){freebsd|postgresql}.org