Re: elog() patch

Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > Is this what you were looking for? I set client_min_messages to the max
> > of debug5 and the output is attached.
>
> If the DBA wants to do that, I don't have a problem with it. I'm
> wondering what happens if an unprivileged user tries to do it,
> via either PGOPTIONS or Peter's new user/database-local options.
>
> Please note also that I'm wondering about the messages emitted during
> an authorization *failure*, not a successful connection.

You ask a very good question here. I never tested authentication with
debug sent to the client. The answer is that it doesn't work without
the attached patch. Now, I am not about to apply this because it does
change getNotice() to an extern and moves its prototype to libpq-int.h.
This is necessary because I now use getNotice() in fe-connect.c.

The second issue is that this isn't going to work for pre-7.2 clients
because the protocol doesn't expect 'N' messages during the
authentication phase. I think we can live with a client_min_messages
level of debug* not working on old clients, though we should make a
mention of it in the release notes.

And finally, here is the output from a failed password login with the
patch applied:

$ psql test
Password:
DEBUG: received password packet with len=12, pw=lkjasdf

DEBUG: received password packet with len=12, pw=lkjasdf

psql: FATAL: Password authentication failed for user "postgres"

Basically it echoes the failed password back to the user. Again, this
is only with client_min_messages set to debug1-5. I don't know how to
fix this because we specifically set things up so the client could see
everything the server logs see. I wonder if echoing the failed password
into the logs is a good idea either. I don't think so.

Someone please advise on patch application. Are there other places that
don't expect a NOTICE in the middle of a protocol handshake?

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