Vista: Adding a printer connection fails

[Martin Zielinski]

Hello again!

If I'm not too confused by all this testing, the reason for the 
misbehaviour is:
Windows does not accept any unknown binary registry values under the 
DsSpooler key via the SetPrinterDataEx call.

Easy to test: Just try a SetPrinterDataEx call with binary data on a XP 
server under the DsSpooler key: error 0x57!

It looks like Vista tries to store the data to a tempory printer.
For each key it leaves the copy loop on an error condition.
If the DsSpooler key is the last key on the Samba server (which is the 
default), GetLastError() after the procedure is the above mentioned error.

If there are more keys, Vista continues to copy these keys and 
GetLastError() after the whole procedure is ERROR_SUCCESS.
This can be the reason, why adding another key to the printer registry
leeds to a successfull installation of the printer.

On XP machines the PrinterDriverData key seems to be created 
automaticly. So adding a binary data via regedit to the DsSpooler key 
does not leed to this error.

Possible fixes for Samba could be
a) Store the objectGUID value in string-representation
b) Do not store the value under the DsSpooler key
c) Allways Auto-create an empty PrinterDriverData key

BTW. the ObjectGUID key can be found in the XP registry as toplevel string.

Regards,

Martin

Martin Zielinski schrieb:
> Hello list!
> 
> The error case has been originally described in the samba list with the 
> subject "Vista can't use samba hosted printer drivers"
> 
> Using samba 3.0.23d and a printer with a "HP 4000 PCL6" driver from XP.
> 
> Problem:
> When one tries to install a network printer from samba the execution 
> aborts with the error 0x00000057 ( = invalid parameter).
> 
> How to reproduce:
> 1st. Make a fresh install: remove ntprinters.tdb and assign the driver 
> via an rpcclient call.
>  => If you try now to connect with vista, everything is ok
> 
> 2nd. Enter the printers folder from Vista or XP and rightclick on the 
> printer -> properties -> publish printer in the ADS.
>  => Try now to connect with vista and this time Vista produces the 
> error. (And the properties dialog shows no "printing preferences" button).
> 
> What fails:
> The failed System call is an "GetPrinterDriver" call from the Vista 
> client. Not to mistake with the RPC call itself. It's the library call 
> the produces lots of traffic afterwards (GetPrinter calls, enum the 
> registry etc.)
> 
> When does it fail:
> When publishing the printer to the ADS, Samba adds a binary registry 
> value "objectGUID" to the DsSpooler key. (BTW - my XP client publishes 
> the printer automaticly when I open the properties dialog in the 
> "Printers and Faxes" folder on the Samba server with admin rights).
> 
> I renamed the key - no change
> I changed the size of the data - no change
> Added a random key after that key (buffer size???) - no change
> 
> I changed the key type from REG_BINARY to REG_SZ - no error anymore!
> Also, if I add another key to the printers registry (FOO) - no error!
> 
> Why does it fail:
> I have no idea at the moment. Anyone?
> Tried to find alignment issues or sizes - found nothing.
> Also the enumeration of the printers registry is successfull - in every 
> case.
> 
> If I could see this error somewhere on XP, I'd assume it is a Vista bug.
> But until then - It stays at Samba.
> 
> I hope someone gets an idea due to this observations.
> 
> Regards,
> 
> Martin
> 

-- 
Martin Zielinski             mz at seh.de
Software Development
SEH Computertechnik GmbH     www.seh.de