Thread: Re: [INTERFACES] getting "fe_setauthsvc: invalid name" error

Re: [INTERFACES] getting "fe_setauthsvc: invalid name" error

From
Midwest Online
Date:
Tom Lane wrote:
>
> My guess is that the execution environment is different for your CGI
> program, with respect to either username or lack of one of the
> environment variables that libpq pays attention to (PGPORT, etc).

I think you're right, Tom.  If I run the program on my Linux box as a
different user, I get the same error.  Now, how do I set the username
from C/C++??  I can't figure it out from the docs ...

> BTW, hackers: when I looked into pgconnection.cc, I was astonished
> and dismayed by the number of instantly visible bugs.  This code is in
> *horrible* shape --- it's amazing it works at all.  Someone is going to
> have to adopt libpq++ and give it a close going-over.

I wish I knew enough about C++.  :)

Thanks for your help, Tom!

Clint
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Re: [INTERFACES] getting "fe_setauthsvc: invalid name" error

From
Torsten Neuer
Date:
Clint wrote:
>
>I think you're right, Tom.  If I run the program on my Linux box as a
>different user, I get the same error.  Now, how do I set the username
>from C/C++??  I can't figure it out from the docs ...
>
At the first glance I would suggest you either do a chown(1) on
the program binary so that is executes as the correct user or you
have a set*id(2) call somewhere in the program source.
However, you should take care with that as this can result in a
security leak in your system.

Torsten

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Re: [INTERFACES] getting "fe_setauthsvc: invalid name" error

From
Sebastian Meyer
Date:
On Wed, 16 Sep 1998, Torsten Neuer wrote:

> Clint wrote:
> >
> >I think you're right, Tom.  If I run the program on my Linux box as a
> >different user, I get the same error.  Now, how do I set the username
> >from C/C++??  I can't figure it out from the docs ...
>
> At the first glance I would suggest you either do a chown(1) on
> the program binary so that is executes as the correct user or you
> have a set*id(2) call somewhere in the program source.
> However, you should take care with that as this can result in a
> security leak in your system.

Its in http://www.PostgreSQL.ORG/docs/postgres/libpq9374.htm
Read the section on "PQsetdbLogin - Makes a new connection to a backend"

PGconn *PQsetdbLogin(const char *pghost,
                const char *pgport,
                const char *pgoptions,
                const char *pgtty,
                const char *dbName,
                const char *login,
                const char *pwd);
       If any argument is NULL, then the corresponding environment
       variable is checked. If the environment variable is also not set,
       then hardwired defaults are used. PQsetdbLogin always returns a
       valid PGconn pointer. The PQstatus (see below) command should be
       called to ensure that a connection was properly made before
       queries are sent via the connection.

It's so easy... If you should want to set environment variables anyway:
environ(5), getenv(3) and putenv(3) tell you how.

Finally: Don't deal with set*id() calls unless absolutely neccessary AND
you really know what you do.The first condition returns FALSE here.

sebastian
--
    __o     Sebastian Meyer  Tel: (0421)218-7702 | "Everything should be
  _ \<,_    meyer@mevis.de   http://www.mevis.de | made as simple as possible,
 (_)/ (_)   MeVis an der Universität Bremen      | but not simpler."
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Re: [INTERFACES] getting "fe_setauthsvc: invalid name" error

From
Tom Lane
Date:
Sebastian Meyer <meyer@mevis.de> writes:
> On Wed, 16 Sep 1998, Torsten Neuer wrote:
>> Clint wrote:
>>>> I think you're right, Tom.  If I run the program on my Linux box as a
>>>> different user, I get the same error.  Now, how do I set the username
>>>> from C/C++??  I can't figure it out from the docs ...

> Its in http://www.PostgreSQL.ORG/docs/postgres/libpq9374.htm
> Read the section on "PQsetdbLogin - Makes a new connection to a backend"

Ah, but Clint's real problem is that he's not calling libpq directly,
but via libpq++.  And as far as I can see, libpq++ doesn't have any way
to open a connection except by calling plain old PQsetdb.  This needs to
be fixed.  (We should add an entry point to libpq++ that corresponds to
PQconnectdb, so that the connection parameters are passed through as a
single string and libpq++ doesn't have to know about each and every one
of 'em.)

The short-term workaround is what you mention next:

> It's so easy... If you should want to set environment variables anyway:
> environ(5), getenv(3) and putenv(3) tell you how.

Setting PGUSER (and PGPASSWORD if needed) env. variables will provide a
way to pass these items to libpq despite the lack of any cooperation
from libpq++.

            regards, tom lane

Re: [INTERFACES] getting "fe_setauthsvc: invalid name" error

From
Midwest Online
Date:
Tom Lane wrote:
>
> Ah, but Clint's real problem is that he's not calling libpq directly,
> but via libpq++.  And as far as I can see, libpq++ doesn't have any way
> to open a connection except by calling plain old PQsetdb.  This needs to
> be fixed.  (We should add an entry point to libpq++ that corresponds to
> PQconnectdb, so that the connection parameters are passed through as a
> single string and libpq++ doesn't have to know about each and every one
> of 'em.)
>
> The short-term workaround is what you mention next:
>
> > It's so easy... If you should want to set environment variables anyway:
> > environ(5), getenv(3) and putenv(3) tell you how.
>
> Setting PGUSER (and PGPASSWORD if needed) env. variables will provide a
> way to pass these items to libpq despite the lack of any cooperation
> from libpq++.

Bingo!  Tom, what you said about PGUSER triggered something I was
wondering about: if running as a virtual web server was different (and
how) from running at the command line.  Here's the fix I used:

I used some C code from the examples directory to make the same
connection through the web server.  I still wasn't getting connected,
but at least the error message in the server's log was informative: it
said it failed during a call to getprotobyname().  I had no clue what it
was, but looked it up.  It says that it reads /etc/protocols.  I somehow
"knew" that /etc/protocols didn't exist while running through the web
server; our hosting company had mentioned before that the file
permissions, etc. are different - more protected - from httpd.  So, the
easy fix was to copy /etc/protocols to ~/etc/protocols (a directory
"readable" from our virtual server's httpd process.  It worked like a
charm. :)
I have no clue if it's a "legitimate" fix, or if any harm can be done,
but for now it's staying.  :)

Thanks go out to Tom Lane and everybody that offered help!

Clint
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            Belinda & Clint Forgy
Midwest Online                    PeculiarWeb Internet Designs
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