path: root/docs/docbook/projdoc/printer_driver2.sgml

<chapter>


<chapterinfo>
	<author>
		<firstname>Gerald (Jerry)</firstname><surname>Carter</surname>
		<affiliation>
			<orgname>Samba Team</orgname>
			<address>
				<email>jerry@samba.org</email>
			</address>
		</affiliation>
	</author>
	
		
	<pubdate> (3 May 2001) </pubdate>
</chapterinfo>

<title>Printing Support in Samba 2.2.x</title>

<sect1>
<title>Introduction</title>
	
<para>Beginning with the 2.2.0 release, Samba supports 
the native Windows NT printing mechanisms implemented via 
MS-RPC (i.e. the SPOOLSS named pipe).  Previous versions of 
Samba only supported LanMan printing calls.</para>

<para>The additional functionality provided by the new 
SPOOLSS support includes:</para>
	
<itemizedlist>
	<listitem><para>Support for downloading printer driver 
	files to Windows 95/98/NT/2000 clients upon demand.
	</para></listitem>
	
	<listitem><para>Uploading of printer drivers via the 
	Windows NT Add Printer Wizard (APW) or the 
	Imprints tool set (refer to <ulink 
	url="http://imprints.sourceforge.net">http://imprints.sourceforge.net</ulink>). 
	</para></listitem>
		
	<listitem><para>Support for the native MS-RPC printing 
	calls such as StartDocPrinter, EnumJobs(), etc...  (See 
	the MSDN documentation at <ulink 
	url="http://msdn.microsoft.com/">http://msdn.microsoft.com/</ulink> 
	for more information on the Win32 printing API)
	</para></listitem>
		
	<listitem><para>Support for NT Access Control Lists (ACL) 
	on printer objects</para></listitem>
	
	<listitem><para>Improved support for printer queue manipulation 
	through the use of an internal databases for spooled job 
	information</para></listitem>
</itemizedlist>

<para>
There has been some initial confusion about what all this means
and whether or not it is a requirement for printer drivers to be 
installed on a Samba host in order to support printing from Windows 
clients.  A bug existed in Samba 2.2.0 which made Windows NT/2000 clients 
require that the Samba server possess a valid driver for the printer.  
This is fixed in Samba 2.2.1 and once again, Windows NT/2000 clients
can use the local APW for installing drivers to be used with a Samba 
served printer.  This is the same behavior exhibited by Windows 9x clients.
As a side note, Samba does not use these drivers in any way to process 
spooled files.  They are utilized entirely by the clients.
</para>

<para>
The following MS KB article, may be of some help if you are dealing with
Windows 2000 clients:  <emphasis>How to Add Printers with No User 
Interaction in Windows 2000</emphasis>
</para>

<para>
<ulink url="http://support.microsoft.com/support/kb/articles/Q189/1/05.ASP">http://support.microsoft.com/support/kb/articles/Q189/1/05.ASP</ulink>
</para>

</sect1>


<sect1>
<title>Configuration</title>

<warning>
<title>[print$] vs. [printer$]</title>

<para>
Previous versions of Samba recommended using a share named [printer$].  
This name was taken from the printer$ service created by Windows 9x 
clients when a printer was shared.  Windows 9x printer servers always have 
a printer$ service which provides read-only access via no 
password in order to support printer driver downloads.
</para>
	
<para>
However, the initial implementation allowed for a 
parameter named <parameter>printer driver location</parameter> 
to be used on a per share basis to specify the location of 
the driver files associated with that printer.  Another 
parameter named <parameter>printer driver</parameter> provided 
a means of defining the printer driver name to be sent to 
the client.
</para>
 
<para>
These parameters, including <parameter>printer driver
file</parameter> parameter, are being depreciated and should not 
be used in new installations.  For more information on this change, 
you should refer to the <link linkend="MIGRATION">Migration section</link>
of this document.
</para>
</warning>

<sect2>
<title>Creating [print$]</title>	

<para>
In order to support the uploading of printer driver 
files, you must first configure a file share named [print$].  
The name of this share is hard coded in Samba's internals so 
the name is very important (print$ is the service used by 
Windows NT print servers to provide support for printer driver 
download).
</para>

<para>You should modify the server's smb.conf file to create the 
following file share (of course, some of the parameter values,
such as 'path' are arbitrary and should be replaced with
appropriate values for your site):</para>

<para><programlisting>
[print$]
    path = /usr/local/samba/printers
    guest ok = yes
    browseable = yes
    read only = yes
    ; since this share is configured as read only, then we need
    ; a 'write list'.  Check the file system permissions to make
    ; sure this account can copy files to the share.  If this
    ; is setup to a non-root account, then it should also exist
    ; as a 'printer admin'
    write list = ntadmin
</programlisting></para>
	
<para>The <ulink url="smb.conf.5.html#WRITELIST"><parameter>
write list</parameter></ulink> is used to allow administrative 
level user accounts to have write access in order to update files 
on the share.  See the <ulink url="smb./conf.5.html">smb.conf(5) 
man page</ulink> for more information on configuring file shares.</para>
	
<para>The requirement for <ulink url="smb.conf.5.html#GUESTOK"><command>guest 
ok = yes</command></ulink> depends upon how your
site is configured.  If users will be guaranteed to have 
an account on the Samba host, then this is a non-issue.</para>

<note>	
<title>Author's Note</title>

<para>
The non-issue is that if all your Windows NT users are guaranteed to be 
authenticated by the Samba server (such as a domain member server and the NT 
user has already been validated by the Domain Controller in 
order to logon to the Windows NT console), then guest access 
is not necessary.  Of course, in a workgroup environment where 
you just want to be able to print without worrying about 
silly accounts and security, then configure the share for 
guest access.  You'll probably want to add <ulink 
url="smb.conf.5.html#MAPTOGUEST"><command>map to guest = Bad User
</command></ulink> in the [global] section as well.  Make sure 
you understand what this parameter does before using it 
though. --jerry
</para>
</note>

<para>In order for a Windows NT print server to support 
the downloading of driver files by multiple client architectures,
it must create subdirectories within the [print$] service
which correspond to each of the supported client architectures.
Samba follows this model as well.</para>

<para>Next create the directory tree below the [print$] share 
for each architecture you wish to support.</para>

<para><programlisting>
[print$]-----
        |-W32X86           ; "Windows NT x86"
        |-WIN40            ; "Windows 95/98"
        |-W32ALPHA         ; "Windows NT Alpha_AXP"
        |-W32MIPS          ; "Windows NT R4000"
        |-W32PPC           ; "Windows NT PowerPC"
</programlisting></para>

<warning>
<title>ATTENTION!  REQUIRED PERMISSIONS</title>
	
<para>
In order to currently add a new driver to you Samba host, 
one of two conditions must hold true:
</para>
		
<itemizedlist>
	<listitem><para>The account used to connect to the Samba host 
	must have a uid of 0 (i.e. a root account)</para></listitem>
		
	<listitem><para>The account used to connect to the Samba host
	must be a member of the <ulink 
	url="smb.conf.5.html#PRINTERADMIN"><parameter>printer 
	admin</parameter></ulink> list.</para></listitem>
</itemizedlist>

<para>
Of course, the connected account must still possess access
to add files to the subdirectories beneath [print$]. Remember
that all file shares are set to 'read only' by default.
</para>
</warning>


<para>
Once you have created the required [print$] service and 
associated subdirectories, simply log onto the Samba server using 
a root (or <parameter>printer admin</parameter>) account
from a Windows NT 4.0 client.  Navigate to the "Printers" folder
on the Samba server.  You should see an initial listing of printers
that matches the printer shares defined on your Samba host.
</para>
</sect2>

<sect2>
<title>Setting Drivers for Existing Printers</title>

<para>The initial listing of printers in the Samba host's 
Printers folder will have no real printer driver assigned 
to them.  By default, in Samba 2.2.0 this driver name was set to 
<emphasis>NO PRINTER DRIVER AVAILABLE FOR THIS PRINTER</emphasis>.
Later versions changed this to a NULL string to allow the use
tof the local Add Printer Wizard on NT/2000 clients.
Attempting to view the printer properties for a printer
which has this default driver assigned will result in 
the error message:</para>

<para>
<emphasis>Device settings cannot be displayed.  The driver 
for the specified printer is not installed, only spooler 
properties will be displayed.  Do you want to install the 
driver now?</emphasis>
</para>

<para>
Click "No" in the error dialog and you will be presented with
the printer properties window.  The way assign a driver to a 
printer is to either
</para>
	
<itemizedlist>
	<listitem><para>Use the "New Driver..." button to install 
	a new printer driver, or</para></listitem>
	
	<listitem><para>Select a driver from the popup list of 
	installed drivers.  Initially this list will be empty.</para>
	</listitem>
</itemizedlist>
	
<para>If you wish to install printer drivers for client 
operating systems other than "Windows NT x86", you will need 
to use the "Sharing" tab of the printer properties dialog.</para>

<para>Assuming you have connected with a root account, you 
will also be able modify other printer properties such as 
ACLs and device settings using this dialog box.</para>

<para>A few closing comments for this section, it is possible 
on a Windows NT print server to have printers
listed in the Printers folder which are not shared.  Samba does
not make this distinction.  By definition, the only printers of
which Samba is aware are those which are specified as shares in
<filename>smb.conf</filename>.</para>
  
<para>Another interesting side note is that Windows NT clients do
not use the SMB printer share, but rather can print directly 
to any printer on another Windows NT host using MS-RPC.  This
of course assumes that the printing client has the necessary
privileges on the remote host serving the printer.  The default
permissions assigned by Windows NT to a printer gives the "Print"
permissions to the "Everyone" well-known group.
</para>

</sect2>	


<sect2>
<title>Support a large number of printers</title>
		
<para>One issue that has arisen during the development
phase of Samba 2.2 is the need to support driver downloads for
100's of printers.  Using the Windows NT APW is somewhat 
awkward to say the list.  If more than one printer are using the 
same driver, the <ulink url="rpcclient.1.html"><command>rpcclient's
setdriver command</command></ulink> can be used to set the driver
associated with an installed driver.  The following is example
of how this could be accomplished:</para>
		
<para><programlisting> 
<prompt>$ </prompt>rpcclient pogo -U root%secret -c "enumdrivers"
Domain=[NARNIA] OS=[Unix] Server=[Samba 2.2.0-alpha3]
 
[Windows NT x86]
Printer Driver Info 1:
     Driver Name: [HP LaserJet 4000 Series PS]
 
Printer Driver Info 1:
     Driver Name: [HP LaserJet 2100 Series PS]
 
Printer Driver Info 1:
     Driver Name: [HP LaserJet 4Si/4SiMX PS]
				  
<prompt>$ </prompt>rpcclient pogo -U root%secret -c "enumprinters"
Domain=[NARNIA] OS=[Unix] Server=[Samba 2.2.0-alpha3]
     flags:[0x800000]
     name:[\\POGO\hp-print]
     description:[POGO\\POGO\hp-print,NO DRIVER AVAILABLE FOR THIS PRINTER,]
     comment:[]
				  
<prompt>$ </prompt>rpcclient pogo -U root%secret \
<prompt>&gt; </prompt> -c "setdriver hp-print \"HP LaserJet 4000 Series PS\""
Domain=[NARNIA] OS=[Unix] Server=[Samba 2.2.0-alpha3]
Successfully set hp-print to driver HP LaserJet 4000 Series PS.
</programlisting></para>
</sect2>



<sect2>
<title>Adding New Printers via the Windows NT APW</title>
	
<para>
By default, Samba offers all printer shares defined in <filename>smb.conf</filename>
in the "Printers..." folder.  Also existing in this folder is the Windows NT 
Add Printer Wizard icon.  The APW will be show only if
</para>

<itemizedlist>
	<listitem><para>The connected user is able to successfully
	execute an OpenPrinterEx(\\server) with administrative
	priviledges (i.e. root or <parameter>printer admin</parameter>).
	</para></listitem>
	
	<listitem><para><ulink url="smb.conf.5.html#SHOWADDPRINTERWIZARD"><parameter>show 
	add printer wizard = yes</parameter></ulink> (the default).
	</para></listitem>
</itemizedlist>

<para>
In order to be able to use the APW to successfully add a printer to a Samba 
server, the <ulink url="smb.conf.5.html#ADDPRINTERCOMMAND"><parameter>add 
printer command</parameter></ulink> must have a defined value.  The program
hook must successfully add the printer to the system (i.e. 
<filename>/etc/printcap</filename> or appropriate files) and 
<filename>smb.conf</filename> if necessary.
</para>

<para>
When using the APW from a client, if the named printer share does 
not exist, <command>smbd</command> will execute the <parameter>add printer 
command</parameter> and reparse to the <filename>smb.conf</filename>
to attempt to locate the new printer share.  If the share is still not defined,
an error of "Access Denied" is returned to the client.  Note that the 
<parameter>add printer program</parameter> is executed under the context
of the connected user, not necessarily a root account.
</para>

<para>
There is a complementing <ulink url="smb.conf.5.html#DELETEPRINTERCOMMAND"><parameter>delete
printer command</parameter></ulink> for removing entries from the "Printers..."
folder.
</para>

</sect2>


<sect2>
<title>Samba and Printer Ports</title>

<para>
Windows NT/2000 print servers associate a port with each printer.  These normally
take the form of LPT1:, COM1:, FILE:, etc...  Samba must also support the
concept of ports associated with a printer.  By default, only one printer port,
named "Samba Printer Port", exists on a system.  Samba does not really a port in
order to print, rather it is a requirement of Windows clients.  
</para>

<para>
Note that Samba does not support the concept of "Printer Pooling" internally 
either.  This is when a logical printer is assigned to multiple ports as 
a form of load balancing or fail over.
</para>

<para>
If you require that multiple ports be defined for some reason,
<filename>smb.conf</filename> possesses a <ulink 
url="smb.conf.5.html#ENUMPORTSCOMMAND"><parameter>enumports 
command</parameter></ulink> which can be used to define an external program 
that generates a listing of ports on a system.
</para>

</sect2>

</sect1>


<sect1>
	<title>The Imprints Toolset</title>
	
	<para>The Imprints tool set provides a UNIX equivalent of the 
	Windows NT Add Printer Wizard.  For complete information, please 
	refer to the Imprints web site at <ulink url="http://imprints.sourceforge.net/">
	http://imprints.sourceforge.net/</ulink> as well as the documentation 
	included with the imprints source distribution.  This section will 
	only provide a brief introduction to the features of Imprints.</para>
	
	
	<sect2>
		<title>What is Imprints?</title>

		<para>Imprints is a collection of tools for supporting the goals 
		of</para>
		
		<itemizedlist>
			<listitem><para>Providing a central repository information 
			regarding Windows NT and 95/98 printer driver packages</para>
			</listitem>
			
			<listitem><para>Providing the tools necessary for creating 
			the Imprints printer driver packages.</para></listitem>
			
			<listitem><para>Providing an installation client which 
			will obtain and install printer drivers on remote Samba 
			and Windows NT 4 print servers.</para></listitem>
		</itemizedlist>
		
	</sect2>
	
	
	<sect2>
		<title>Creating Printer Driver Packages</title>
		
		<para>The process of creating printer driver packages is beyond
		the scope of this document (refer to Imprints.txt also included
		with the Samba distribution for more information).  In short,
		an Imprints driver package is a gzipped tarball containing the
		driver files, related INF files, and a control file needed by the
		installation client.</para>
	</sect2>
	
	
	<sect2>
		<title>The Imprints server</title>
		
		<para>The Imprints server is really a database server that 
		may be queried via standard HTTP mechanisms.  Each printer 
		entry in the database has an associated URL for the actual
		downloading of the package.  Each package is digitally signed
		via GnuPG which can be used to verify that package downloaded
		is actually the one referred in the Imprints database.  It is 
		<emphasis>not</emphasis> recommended that this security check 
		be disabled.</para>
	</sect2>
	
	<sect2>
		<title>The Installation Client</title>

		<para>More information regarding the Imprints installation client 
		is available in the <filename>Imprints-Client-HOWTO.ps</filename> 
		file included with the imprints source package.</para>

		<para>The Imprints installation client comes in two forms.</para>

		<itemizedlist>
			<listitem><para>a set of command line Perl scripts</para>
			</listitem>
			
			<listitem><para>a GTK+ based graphical interface to 
			the command line perl scripts</para></listitem>
		</itemizedlist>
		
		<para>The installation client (in both forms) provides a means
		of querying the Imprints database server for a matching
		list of known printer model names as well as a means to 
		download and install the drivers on remote Samba and Windows
		NT print servers.</para>

		<para>The basic installation process is in four steps and 
		perl code is wrapped around <command>smbclient</command> 
		and <command>rpcclient</command>.</para>

<para><programlisting>	
foreach (supported architecture for a given driver)
{
     1.  rpcclient: Get the appropriate upload directory 
         on the remote server
     2.  smbclient: Upload the driver files
     3.  rpcclient: Issues an AddPrinterDriver() MS-RPC
}
	
4.  rpcclient: Issue an AddPrinterEx() MS-RPC to actually
    create the printer
</programlisting></para>
		
		<para>One of the problems encountered when implementing 
		the Imprints tool set was the name space issues between 
		various supported client architectures.  For example, Windows 
		NT includes a driver named "Apple LaserWriter II NTX v51.8" 
		and Windows 95 callsits version of this driver "Apple 
		LaserWriter II NTX"</para>
		
		<para>The problem is how to know what client drivers have 
		been uploaded for a printer.  As astute reader will remember 
		that the Windows NT Printer Properties dialog only includes 
		space for one printer driver name.  A quick look in the 
		Windows NT 4.0 system registry at</para>
	
		<para><filename>HKLM\System\CurrentControlSet\Control\Print\Environment
		</filename></para>
		
		<para>will reveal that Windows NT always uses the NT driver 
		name.  This is ok as Windows NT always requires that at least 
		the Windows NT version of the printer driver is present.  
		However, Samba does not have the requirement internally.  
		Therefore, how can you use the NT driver name if is has not 
		already been installed?</para>
		
		<para>The way of sidestepping this limitation is to require 
		that all Imprints printer driver packages include both the Intel 
		Windows NT and 95/98 printer drivers and that NT driver is 
		installed first.</para>
	</sect2>
	
</sect1>


<sect1>
<title><anchor id="MIGRATION">Migration to from Samba 2.0.x to 2.2.x</title>

<para>
Given that printer driver management has changed (we hope improved) in 
2.2 over prior releases, migration from an existing setup to 2.2 can 
follow several paths.
</para>

<para>
Windows clients have a tendency to remember things for quite a while.
For example, if a Windows NT client has attached to a Samba 2.0 server,
it will remember the server as a LanMan printer server.  Upgrading 
the Samba host to 2.2 makes support for MSRPC printing possible, but 
the NT client will still remember the previous setting.
</para>

<para>
In order to give an NT client printing "amesia" (only necessary if you 
want to use the newer MSRPC printing functionality in Samba), delete 
the registry keys associated with the print server contained in 
<constant>[HKLM\SYSTEM\CurrentControlSet\Control\Print]</constant>.  The 
spooler service on the client should be stopped prior to doing this:
</para>

<para>
<prompt>C:\WINNT\ ></prompt> <userinput>net stop spooler</userinput>
</para>

<para>
<emphasis>All the normal disclaimers about editing the registry go 
here.</emphasis>  Be careful, and know what you are doing.
</para>

<para>
The spooler service should be restarted after you have finished 
removing the appropriate registry entries by replacing the 
<command>stop</command> command above with <command>start</command>.
</para>

<para>
Windows 9x clients will continue to use LanMan printing calls
with a 2.2 Samba server so there is no need to perform any of these
modifications on non-NT clients.
</para>
	
<warning>
<title>Achtung!</title>

<para>
The following smb.conf parameters are considered to be depreciated and will 
be removed soon.  Do not use them in new installations
</para>
		
<itemizedlist>
	<listitem><para><parameter>printer driver file (G)</parameter>
	</para></listitem>
			
	<listitem><para><parameter>printer driver (S)</parameter>
	</para></listitem>
			
	<listitem><para><parameter>printer driver location (S)</parameter>
	</para></listitem>
</itemizedlist>
</warning>


<para>
Here are the possible scenarios for supporting migration:
</para>
	
<itemizedlist>
	<listitem><para>If you do not desire the new Windows NT 
	print driver support, nothing needs to be done.  
	All existing parameters work the same.</para></listitem>

	<listitem><para>If you want to take advantage of NT printer 
	driver support but do not want to migrate the 
	9x drivers to the new setup, the leave the existing 
	printers.def file.  When smbd attempts to locate a 
	9x driver for the printer in the TDB and fails it 
	will drop down to using the printers.def (and all 
	associated parameters).  The <command>make_printerdef</command> 
	tool will also remain for backwards compatibility but will 
	be moved to the "this tool is the old way of doing it" 
	pile.</para></listitem>

	<listitem><para>If you install a Windows 9x driver for a printer 
	on your Samba host (in the printing TDB), this information will 
	take precedence and the three old printing parameters
	will be ignored (including print driver location).</para></listitem>

	<listitem><para>If you want to migrate an existing <filename>printers.def</filename> 
	file into the new setup, the current only solution is to use the Windows 
	NT APW to install the NT drivers and the 9x  drivers.  This can be scripted 
	using <command>smbclient</command> and <command>rpcclient</command>.  See the 
	Imprints installation client at <ulink 
	url="http://imprints.sourceforge.net/">http://imprints.sourceforge.net/</ulink> 
	for an example.
	</para></listitem>
</itemizedlist>

</sect1>


<!--

  This comment from rpc_server/srv_spoolss_nt.c:_spoolss_open_printer_ex()
  needs to be added into a section probably.  This is to remind me it needs 
  to be done.  -jerry

                /*
                 * If the openprinterex rpc call contains a devmode,
                 * it's a per-user one. This per-user devmode is derivated
                 * from the global devmode. Openprinterex() contains a per-user
                 * devmode for when you do EMF printing and spooling.
                 * In the EMF case, the NT workstation is only doing half the job
                 * of rendering the page. The other half is done by running the printer
                 * driver on the server.
                 * The EMF file doesn't contain the page description (paper size, orientation, ...).
                 * The EMF file only contains what is to be printed on the page.
                 * So in order for the server to know how to print, the NT client sends
                 * a devicemode attached to the openprinterex call.
                 * But this devicemode is short lived, it's only valid for the current print job.
                 *
                 * If Samba would have supported EMF spooling, this devicemode would
                 * have been attached to the handle, to sent it to the driver to correctly
                 * rasterize the EMF file.
                 *
                 * As Samba only supports RAW spooling, we only receive a ready-to-print file,
                 * we just act as a pass-thru between windows and the printer.
                 *
                 * In order to know that Samba supports only RAW spooling, NT has to call
                 * getprinter() at level 2 (attribute field) or NT has to call startdoc()
                 * and until NT sends a RAW job, we refuse it.
                 *
                 * But to call getprinter() or startdoc(), you first need a valid handle,
                 * and to get an handle you have to call openprintex(). Hence why you have
                 * a devicemode in the openprinterex() call.
                 *
                 *
                 * Differences between NT4 and NT 2000.
                 * NT4:
                 * 
                 * On NT4, you only have a global devicemode. This global devicemode can be changed
                 * by the administrator (or by a user with enough privs). Everytime a user
                 * wants to print, the devicemode is resetted to the default. In Word, everytime
                 * you print, the printer's characteristics are always reset to the global devicemode.
                 *
                 * NT 2000:
                 * 
                 * In W2K, there is the notion of per-user devicemode. The first time you use
                 * a printer, a per-user devicemode is build from the global devicemode.
                 * If you change your per-user devicemode, it is saved in the registry, under the
                 * H_KEY_CURRENT_KEY sub_tree. So that everytime you print, you have your default
                 * printer preferences available.
                 *
                 * To change the per-user devicemode: it's the "Printing Preferences ..." button
                 * on the General Tab of the printer properties windows.
                 *
                 * To change the global devicemode: it's the "Printing Defaults..." button
                 * on the Advanced Tab of the printer properties window.
-->

</chapter>