[Samba] Almost all print driver uploads fail

[Egerváry Gergely]

Hi,

I'm working on a minimal print server setup for Windows 10/11 x64 clients.
No domain, no Kerberos, no LDAP, only a few local users on a standalone 
server with some shared CUPS printers.
Printing works well.

After setting 'spoolss: os_major = 6' and 'spoolss: os_minor = 1' The 
*Kyocera KX Universal Driver* has uploaded well. But, that's all.

No success uploading other print drivers, like *HP Universal Printing 
PCL6* and *Canon Generic Plus PCL6
*All of them are failing with messages like:

    "Unable to install HP Universal Printing PCL 6, Type 3 - User Mode,
    x64 driver."
    This operation is not supported

and

    "Unable to install Canon Generic Plus PCL6, Type 3 - User Mode, x64
    driver."
    This operation is not supported

The print$ share is writable, the files are copying to the temporary 
upload folder. And note that the Kyocera driver uploads well. It's 100% 
reproducible.

Increased logging produces tons of logs, but no decodable error messages 
in them, at least for me.

Server side: Debian 12 (bookworm) with stock 4.17.x and 
bookworm-backports (4.19.4), but tried with old SLES 12 server with 4.6.x
Client side: Windows 10 22H2 x64 and Windows 11 23H2 x64, "Print 
Management" with app.
See my smb.conf below.

Do you have any ideas? Is print driver uploading known to be broken? Is 
these Canon and HP drivers are known to be broken?
Do you have working print servers with print drivers uploaded? What 
drivers are you using?

Thanks!

[global]
     netbios name = SANDBOX
     workgroup = POLI
     server role = standalone
     server string = SANDBOX Samba

     printing = cups
     printcap name = cups
     printcap cache time = 750
     cups options = raw

     spoolss: architecture = Windows x64
     spoolss: os_major = 6
     spoolss: os_minor = 1
     rpcd_spoolss: num_workers = 10
     rpcd_spoolss: idle_seconds = 300

     log level = 2 auth:3
     username map = /etc/samba/smbusers

[print$]
     comment = Printer Driver Store
     path = /var/lib/samba/drivers
     read only = No

[printers]
     comment = All Printers
     path = /var/lib/samba/printers
     browsable = Yes
     printable = Yes