samba - Mar 2005 - [BUG] Samba 3.0.11: nmbd forgets to close stderr

To start all the daemons in my Linuxes I use the code like:

        errtext=`daemon 2>&1`
        if [ $? -ne 0 ]; do smth. with errtext too...

And this used to work for Samba as well.  But for 3.0.11 (and very
probably not only for this release) this code doesn't work for nmbd:
`nmbd 2>&1` freezes forever.  But the daemon is started and works at
the same time.  And the shell gives the control back only after the
daemon is stopped.  This looks like nmbd holds stderr opened after
fork or so.  Then, this dummy patch cures all the things back:


--- nmbd/nmbd.c
+++ nmbd/nmbd.c
@@ -766,6 +766,7 @@ static BOOL open_sockets(BOOL isdaemon, 
 	/* We can only take signals in the select. */
 	BlockSignals( True, SIGTERM );
 
+	close(2);
 	process();
 
 	if (dbf)


So, this confirms that stderr is left opened by the daemon.

I can't say when this bug has arisen exactly.  All I know is that it
does not present in 3.0.4 and presents in 3.0.11.

On Monday 28 March 2005 11:43, Denis Zaitsev wrote:
> To start all the daemons in my Linuxes I use the code like:
>
>         errtext=`daemon 2>&1`
>         if [ $? -ne 0 ]; do smth. with errtext too...
>
> And this used to work for Samba as well.  But for 3.0.11 (and very
> probably not only for this release) this code doesn't work for nmbd:
> `nmbd 2>&1` freezes forever.  But the daemon is started and works at
> the same time.  And the shell gives the control back only after the
> daemon is stopped.  This looks like nmbd holds stderr opened after
> fork or so.  Then, this dummy patch cures all the things back:
>
>
> --- nmbd/nmbd.c
> +++ nmbd/nmbd.c
> @@ -766,6 +766,7 @@ static BOOL open_sockets(BOOL isdaemon,
>  	/* We can only take signals in the select. */
>  	BlockSignals( True, SIGTERM );
>
> +	close(2);
>  	process();
>
>  	if (dbf)
>
>
> So, this confirms that stderr is left opened by the daemon.
>
> I can't say when this bug has arisen exactly.  All I know is that it
> does not present in 3.0.4 and presents in 3.0.11.
Please post this as a bug report on https://bugzilla.samba.org - that way it 
will get fixed.

- John T.
-- 
John H Terpstra
Samba-Team Member
Phone: +1 (650) 580-8668

Author:
The Official Samba-3 HOWTO & Reference Guide, ISBN: 0131453556
Samba-3 by Example, ISBN: 0131472216
Hardening Linux, ISBN: 0072254971
Other books in production.