6. Sharing printers with CUPS

The Common UNIX Printing System (CUPS) is a software providing a portable printing layer for UNIX-based operating systems. It will allow us to turn the system into a printer server and share printers with Samba; though this is not a particularly difficult task, please be sure to closely follow this procedure to successfully export the printer(s) to Samba through the cupsaddsmb(8) command.

You should already have installed CUPS as a dependency when adding the Samba package. CUPS configuration goes beyond the scope of this document, so please refer to the documentation for a detailed description of its features and options. The following configuration will refer to my own printer (a Dell 1600n Laser printer), so make sure to correctly configure your own printer(s) before proceeding to Samba configuration. The printers are defined in the /etc/cups/printers.conf(5) configuration file:

<DefaultPrinter dp1600n>
    Info         Dell Laser Printer 1600n
    Location     Room 123
    DeviceURI    ipp://prn1.lan.kernel-panic.it/
    State        Idle
    StateMessage Printer is idle
    Accepting    Yes

6.1 Getting the driver files

Now we have to retrieve the correct driver files. First, we need the Universal PostScript printer drivers for Windows from the Adobe website. You can download them here: select the installer for your language and install the drivers on a Windows machine. At the end of the installation, you should find the following files in the C:\WINDOWS\system32\spool\drivers\w32x86\3 folder:

Now create the /usr/local/share/cups/drivers directory on the file server:

# mkdir /usr/local/share/cups/drivers/

and copy the above files into it (warning: on the file server, driver file names must be lowercase!).

Next, we need to download the Windows CUPS drivers and extract and copy them to the drivers directory:

# tar -zxvf cups-windows-6.0-source.tar.gz
[ ... ]
# cd cups-windows-6.0/i386
# cp cups6.ini cupsui6.dll cupsps6.dll /usr/local/share/cups/drivers/

The last file you need to retrieve is the PPD file appropriate to your printer. Fortunately, if you can't find the file on the printer driver CD, Easy Software Products provides a huge collection of PPD files which includes support for the most common printers. Download the Linux file (portable format), extract it, look for the PPD file appopriate to your printer and copy it to /etc/cups/ppd/; for example:

# tar -zxvf printpro-4.5.12-linux-intel.tar.gz
[ ... ]
# tar -zxvf printpro-dell.ss
[ ... ]
# gunzip -o /etc/cups/ppd/dp1600n.ppd usr/share/cups/model/en/dp1600n.ppd.gz

Please note that the PPD file has exactly the same name ("dp1600n") as the printer defined in /etc/cups/printers.conf(5) (plus the ".ppd" extension). If the two names differ, you may encounter problems when running the cupsaddsmb(8) command later.

6.2 Exporting printers to Samba

Now we can proceed to update Samba configuration by adding a few options to the [global] section and by defining a couple of additional sections:

    [ ... ]

    load printers = yes
    printing = cups
    printcap name = cups
    show add printer wizard = Yes
    use client driver = No

    comment = Dell Laser MFP 1600n
# Users must have write access to the spool directory
    valid users = root @DomainUsers
    path = /var/spool/samba/printing
    printer = dp1600n
    public = no
    writable = no
    printable = yes

    comment = Printer Drivers
    path = /etc/samba/drivers
    browseable = no
    guest ok = no
    read only = yes
    write list = root

The spool directory must be writeable by the users authorized to print and have the sticky-bit set; for example:

# chgrp 513 /var/spool/samba/printing
# chmod 1770 /var/spool/samba/printing

Now we can start the cupsd(8) daemon and reload Samba configuration:

# /usr/local/sbin/cupsd
# pkill -HUP smbd

Well, so we're finally ready to issue the cupsaddsmb(8) command, which will actually export printers to samba:

# mkdir /etc/samba/drivers
# cupsaddsmb -H localhost -U root -v -a
[ ... ]
Printer Driver dp1600n successfully installed.
[ ... ]
Succesfully set dp1600n to driver dp1600n.


If everything went fine, now you should find the PostScript drivers and the PPD file(s) in the fresh new /etc/samba/drivers/W32X86/3 directory:

# ls -l /etc/samba/drivers/W32X86/3/
total 2884
-rwxr--r--  1 root  wheel   25729 Feb 28 01:55 dp1600n.ppd
-rwxr--r--  1 root  wheel  129024 Feb 28 01:49 ps5ui.dll
-rwxr--r--  1 root  wheel   26038 Feb 28 01:55 pscript.hlp
-rwxr--r--  1 root  wheel  792644 Feb 28 01:55 pscript.ntf
-rwxr--r--  1 root  wheel  455168 Feb 28 01:49 pscript5.dll

The last step is configuring the system to run cupsd(8) on boot, by adding the following lines to the /etc/rc.local file, before the start of Samba:

if [ -x /usr/local/sbin/cupsd ]; then
    echo -n ' cupsd'