LPRng-HOWTO: 15 Oct 2001 (For LPRng-3.7.9)
Prev | Chapter 2. Installation | Next

# 2.12. SAMBA and LPRng

The SMB network protocol is used by many Microsoft Operating Systems to implement file and printer sharing. SAMBA is a UNIX package that implements the SMB protocol and provides a simple and easy way to import and export file systems and printer facilities. The web site for SAMBA is http://www.samba.org. The SAMBA code is extremely easy to install and the SWAT (Samba Web Administration Tool) makes configuration almost trivial.

The See the SAMBA `doc/text/Printing.txt` and related documentation for details on printing. In the `samba.conf` file `[global]` section or in the SWAT page for printing configuration you need to specify the that you want to have Samba handle printing, the `print`, lpq, and lprm commands to be used when a user prints a job, asks for status, or removes a job, and a temporary directory to hold print jobs when they are submitted. The following is a simple example of to set up printing for authenticated users.

        [printers]
            path = /var/spool/lpd/samba
            #  ---  do not use the Samba default path = /tmp
            print ok = yes
            printing = lprng
            load printers = yes
            guest ok = no
            printcap name = /etc/printcap
            print command =      /usr/bin/lpr  -P%p -r %s
            lpq command   =      /usr/bin/lpq  -P%p
            lprm command  =      /usr/bin/lprm -P%p %j
            lppause command =    /usr/sbin/lpc hold %p %j
            lpresume command =   /usr/sbin/lpc release %p %j
            queuepause command = /usr/sbin/lpc  -P%p stop
            queueresume command = /usr/sbin/lpc -P%p start

1. Samba will make a copy of the files to be printed in the directory specified by `path`. If the print operation fails then sometimes the print file is left in the directory.

2. The directory should have the same ownership and permissions as `/tmp`, i.e.- owner and group `root` and `bin`, with `01777` permissions, where `01000` is the sticky bit.

   A directory whose `sticky bit' is set becomes an append-only directory, or, more accurately, a directory in which the deletion of files is re- stricted. A file in a sticky directory may only be removed or renamed by a user if the user has write permission for the directory and the user is the owner of the file, the owner of the directory, or the super-user. This feature is usefully applied to directories such as /tmp which must be publicly writable but should deny users the license to arbitrarily delete or rename each others' files.

3. The directory should be examined periodically and files older then a day should be removed. The following command can be used to do this, and should be put in a file that is periodically (one a day) executed by the cron facility:

           find /var/spool/lpd/samba -type f -mtime 2d -exec rm -f {} \;

4. You must specify the print method as `printing = lprng`. This will allow Samba to parse the LPRng lpq status format correctly.

5. You must put all of the printers which Samba has access to in the `printcap` file. Your Samba server may support reading the printcap file by using a program. In this case the printcap file entry can be one of the following:

           [printers]
             #
               printcap name = |/usr/local/libexec/filters/getpc
             # or
               printcap name = |/usr/bin/lpc client all

           #!/bin/sh
           # getpc program
           /usr/bin/lpq -as | /bin/sed -e 's/[@:].*//p'

   The `lpc client all` command will generate the printcap entries for all of the printers. This was done to support Samba and other printer gateway systems. You can also use a simple script to modify the output of the printer status command as shown in the example.

6. Samba can be configured to allow guests or non-authenticated users to spool print jobs. Unfortunately, by default lpr will mark the jobs as submitted by the Samba server, not the remote users. To solve this problem, the `lpr -U%U@%M` option causes lpr to mark the jobs as submitted by user `%U` on host `%M`, instead of the Samba server process. The use of this option is restricted to root and a set of userids listed in the allow_user_setting configuration option. If the userid of the submitter is not in this list, then the option is quietly ignored. The `-U%U@M` can also be used with the other LPRng commands as well. For example:

           [printers]
               guest ok = yes
               print command =       /usr/bin/lpr  -U%U@%M -P%p -r %s
               lpq command   =       /usr/bin/lpq  -U%U@%M -P%p
               lprm command  =       /usr/bin/lprm -U%U@%M -P%p %j
               lppause command =     /usr/sbin/lpc -U%U@%M hold %p %j
               lpresume command =    /usr/sbin/lpc -U%U@%M release %p %j
               queuepause command =  /usr/sbin/lpc -U%U@%M -P%p stop
               queueresume command = /usr/sbin/lpc -U%U@%M -P%p start

Prev | Home | Next
Emulation for UNIX SystemV lp and lpstat | Up | Security Concerns