From 21d26afb2af6ae34219a4286eb7a8896d7e04a3a Mon Sep 17 00:00:00 2001 From: Jelmer Vernooij Date: Sat, 17 Aug 2002 14:15:33 +0000 Subject: sync 3_0 branch with HEAD (This used to be commit 19ab776bf9c91cf4e56887fd7a63d3253b7e36ef) --- docs/htmldocs/Samba-HOWTO-Collection.html | 13851 +++++++++++++++++----------- 1 file changed, 8598 insertions(+), 5253 deletions(-) (limited to 'docs/htmldocs/Samba-HOWTO-Collection.html') diff --git a/docs/htmldocs/Samba-HOWTO-Collection.html b/docs/htmldocs/Samba-HOWTO-Collection.html index 5175bd4c8d..ffb6939e17 100644 --- a/docs/htmldocs/Samba-HOWTO-Collection.html +++ b/docs/htmldocs/Samba-HOWTO-Collection.html @@ -40,7 +40,7 @@ NAME="AEN8" >

Last Update : Mon Apr 1 08:47:26 CST 2002

: Thu Aug 15 12:48:45 CDT 2002

This book is a collection of HOWTOs added to Samba documentation over the years. I try to ensure that all are current, but sometimes the is a larger job @@ -178,64 +178,147 @@ HREF="#AEN199" >

1.10.6. Mapping Usernames
2. Diagnosing your samba server
2.1. Introduction
2.2. Assumptions
2.3. Tests
2.3.1. Test 1
2.3.2. Test 2
2.3.3. Test 3
2.3.4. Test 4
2.3.5. Test 5
2.3.6. Test 6
2.3.7. Test 7
2.3.8. Test 8
2.3.9. Test 9
2.3.10. Test 10
1.10.7. Other Character Sets2.3.11. Test 11
2.4. Still having troubles?
2. 3. Integrating MS Windows networks with Samba
2.1. 3.1. Agenda
2.2. 3.2. Name Resolution in a pure Unix/Linux world
2.2.1. 3.2.1. /etc/hosts
2.2.2. 3.2.2. /etc/resolv.conf
2.2.3. 3.2.3. /etc/host.conf
2.2.4. 3.2.4. /etc/nsswitch.conf
2.3. 3.3. Name resolution as used within MS Windows networking
2.3.1. 3.3.1. The NetBIOS Name Cache
2.3.2. 3.3.2. The LMHOSTS file
2.3.3. 3.3.3. HOSTS file
2.3.4. 3.3.4. DNS Lookup
2.3.5. 3.3.5. WINS Lookup
2.4. 3.4. How browsing functions and how to deploy stable and dependable browsing using Samba
2.5. 3.5. MS Windows security options and how to configure Samba for seemless integration
2.5.1. 3.5.1. Use MS Windows NT as an authentication server
2.5.2. 3.5.2. Make Samba a member of an MS Windows NT security domain
2.5.3. 3.5.3. Configure Samba as an authentication server
2.5.3.1. 3.5.3.1. Users
2.5.3.2. 3.5.3.2. MS Windows NT Machine Accounts
2.6. 3.6. Conclusions
3. 4. Configuring PAM for distributed but centrally managed authentication
3.1. 4.1. Samba and PAM
3.2. 4.2. Distributed Authentication
3.3. 4.3. PAM Configuration in smb.conf
4. 5. Hosting a Microsoft Distributed File System tree on Samba
4.1. 5.1. Instructions
4.1.1. 5.1.1. Notes
5. 6. UNIX Permission Bits and Windows NT Access Control Lists
5.1. 6.1. Viewing and changing UNIX permissions using the NT security dialogs
5.2. 6.2. How to view file security on a Samba share
5.3. 6.3. Viewing file ownership
5.4. 6.4. Viewing file or directory permissions
5.4.1. 6.4.1. File Permissions
5.4.2. 6.4.2. Directory Permissions
5.5. 6.5. Modifying file or directory permissions
5.6. 6.6. Interaction with the standard Samba create mask parameters
5.7. 6.7. Interaction with the standard Samba file attribute mapping
6. 7. Printing Support in Samba 2.2.x
6.1. 7.1. Introduction
6.2. 7.2. Configuration
6.2.1. 7.2.1. Creating [print$]
6.2.2. 7.2.2. Setting Drivers for Existing Printers
6.2.3. 7.2.3. Support a large number of printers
6.2.4. 7.2.4. Adding New Printers via the Windows NT APW
6.2.5. 7.2.5. Samba and Printer Ports
6.3. 7.3. The Imprints Toolset
6.3.1. 7.3.1. What is Imprints?
6.3.2. 7.3.2. Creating Printer Driver Packages
6.3.3. 7.3.3. The Imprints server
6.3.4. 7.3.4. The Installation Client
6.4. 7.4.
7. security = domain in Samba 2.x
7.1. Joining an NT Domain with Samba 2.2
7.2. Samba and Windows 2000 Domains
7.3. Why is this better than security = server?
8. How to Configure Samba 2.2 as a Primary Domain ControllerDebugging Printing Problems
8.1. Prerequisite ReadingIntroduction
8.2. BackgroundDebugging printer problems
8.3. Configuring the Samba Domain ControllerWhat printers do I have?
8.4. Creating Machine Trust Accounts and Joining Clients to the -Domain
8.4.1. Manual Creation of Machine Trust Accounts
8.4.2. "On-the-Fly" Creation of Machine Trust Accounts
8.4.3. Joining the Client to the DomainSetting up printcap and print servers
8.5. Common Problems and ErrorsJob sent, no output
8.6. System Policies and ProfilesJob sent, strange output
8.7. What other help can I get?Raw PostScript printed
8.8. Domain Control for Windows 9x/ME
8.8.1. Configuration Instructions: Network Logons
8.8.2. Configuration Instructions: Setting up Roaming User Profiles
8.8.2.1. Windows NT ConfigurationAdvanced Printing
8.8.2.2. Windows 9X Configuration
8.8.2.3. Win9X and WinNT Configuration
8.8.2.4. Windows 9X Profile Setup
8.8.2.5. Windows NT Workstation 4.0
8.8.2.6. Windows NT Server
8.8.2.7. Sharing Profiles between W95 and NT Workstation 4.0
8.9. DOMAIN_CONTROL.txt : Windows NT Domain Control & SambaReal debugging
9. How to Act as a Backup Domain Controller in a Purely Samba Controlled DomainSecurity levels
9.1. Prerequisite ReadingIntroduction
9.2. Background
9.3. What qualifies a Domain Controller on the network?
9.3.1. How does a Workstation find its domain controller?
9.3.2. When is the PDC needed?
9.4. Can Samba be a Backup Domain Controller?
9.5. How do I set up a Samba BDC?
9.5.1. How do I replicate the smbpasswd file?More complete description of security levels
10. Storing Samba's User/Machine Account information in an LDAP Directorysecurity = domain in Samba 2.x
10.1. PurposeJoining an NT Domain with Samba 2.2
10.2. IntroductionSamba and Windows 2000 Domains
10.3. Supported LDAP Servers
10.4. Schema and Relationship to the RFC 2307 posixAccount
10.5. Configuring Samba with LDAP
10.5.1. OpenLDAP configuration
10.5.2. Configuring Samba
10.6. Accounts and Groups management
10.7. Security and sambaAccount
10.8. LDAP specials attributes for sambaAccounts
10.9. Example LDIF Entries for a sambaAccount
10.10. CommentsWhy is this better than security = server?
11.1. Abstract
11.2. Introduction
11.3. What Winbind Provides
11.3.1. Target Uses
11.4. How Winbind Works
11.4.1. Microsoft Remote Procedure Calls
11.4.2. Name Service Switch
11.4.3. Pluggable Authentication Modules
11.4.4. User and Group ID Allocation
11.4.5. Result Caching
11.5. Installation and Configuration
11.5.1. Introduction
11.5.2. Requirements
11.5.3. Testing Things Out
11.5.3.1. Configure and compile SAMBA
11.5.3.2. Configure nsswitch.conf
11.5.3.3. Configure smb.conf
11.5.3.4. Join the SAMBA server to the PDC domain
11.5.3.5. Start up the winbindd daemon and test it!
11.5.3.6. Fix the /etc/rc.d/init.d/smb startup filesFix the init.d startup scripts
11.5.3.7. Configure Winbind and PAM
11.6. Limitations
11.7. Conclusion
12. OS2 Client HOWTOHow to Configure Samba 2.2 as a Primary Domain Controller
12.1. FAQsPrerequisite Reading
12.2. Background
12.3. Configuring the Samba Domain Controller
12.4. Creating Machine Trust Accounts and Joining Clients to the +Domain
12.1.1. How can I configure OS/2 Warp Connect or - OS/2 Warp 4 as a client for Samba?12.4.1. Manual Creation of Machine Trust Accounts
12.1.2. How can I configure OS/2 Warp 3 (not Connect), - OS/2 1.2, 1.3 or 2.x for Samba?12.4.2. "On-the-Fly" Creation of Machine Trust Accounts
12.1.3. Are there any other issues when OS/2 (any version) - is used as a client?12.4.3. Joining the Client to the Domain
12.1.4. How do I get printer driver download working - for OS/2 clients?12.5. Common Problems and Errors
12.6. System Policies and Profiles
12.7. What other help can I get?
12.8. Domain Control for Windows 9x/ME
12.8.1. Configuration Instructions: Network Logons
12.8.2. Configuration Instructions: Setting up Roaming User Profiles
12.8.2.1. Windows NT Configuration
12.8.2.2. Windows 9X Configuration
12.8.2.3. Win9X and WinNT Configuration
12.8.2.4. Windows 9X Profile Setup
12.8.2.5. Windows NT Workstation 4.0
12.8.2.6. Windows NT Server
12.8.2.7. Sharing Profiles between W95 and NT Workstation 4.0
12.9. DOMAIN_CONTROL.txt : Windows NT Domain Control & Samba
13. HOWTO Access Samba source code via CVSHow to Act as a Backup Domain Controller in a Purely Samba Controlled Domain
13.1. Prerequisite Reading
13.2. Background
13.3. What qualifies a Domain Controller on the network?
13.3.1. How does a Workstation find its domain controller?
13.3.2. When is the PDC needed?
13.4. Can Samba be a Backup Domain Controller?
13.5. How do I set up a Samba BDC?
13.5.1. How do I replicate the smbpasswd file?
14. Storing Samba's User/Machine Account information in an LDAP Directory
14.1. Purpose
14.2. Introduction
13.2. CVS Access to samba.org14.3. Supported LDAP Servers
14.4. Schema and Relationship to the RFC 2307 posixAccount
14.5. Configuring Samba with LDAP
13.2.1. Access via CVSweb14.5.1. OpenLDAP configuration
13.2.2. Access via cvs14.5.2. Configuring Samba
14.6. Accounts and Groups management
14.7. Security and sambaAccount
14.8. LDAP specials attributes for sambaAccounts
14.9. Example LDIF Entries for a sambaAccount
14.10. Comments
Index15. Improved browsing in samba
15.1. Overview of browsing
15.2. Browsing support in samba
15.3. Problem resolution
15.4. Browsing across subnets
15.4.1. How does cross subnet browsing work ?

Chapter 1. How to Install and Test SAMBA

1.1. Step 0: Read the man pages

The man pages distributed with SAMBA contain - lots of useful info that will help to get you started. - If you don't know how to read man pages then try - something like:

$ nroff -man smbd.8 | more -

Other sources of information are pointed to - by the Samba web site, http://www.samba.org

1.2. Step 1: Building the Binaries

To do this, first run the program ./configure - in the source directory. This should automatically - configure Samba for your operating system. If you have unusual - needs then you may wish to run

root# ./configure --help -

first to see what special options you can enable. - Then executing

root# make

will create the binaries. Once it's successfully - compiled you can use

root#

15.5. Setting up a WINS server
15.6. Setting up Browsing in a WORKGROUP
15.7. Setting up Browsing in a DOMAIN
15.8. Forcing samba to be the master
15.9. Making samba the domain master
15.10. Note about broadcast addresses
15.11. Multiple interfaces
16. Samba performance issues
16.1. Comparisons
16.2. Oplocks
16.2.1. Overview
16.2.2. Level2 Oplocks
16.2.3. Old 'fake oplocks' option - deprecated
16.3. Socket options
16.4. Read size
16.5. Max xmit
16.6. Locking
16.7. Share modes
16.8. Log level
16.9. Wide lines
16.10. Read raw
16.11. Write raw
16.12. Read prediction
16.13. Memory mapping
16.14. Slow Clients
16.15. Slow Logins
16.16. Client tuning
16.17. My Results
17. OS2 Client HOWTO
17.1. FAQs
17.1.1. How can I configure OS/2 Warp Connect or + OS/2 Warp 4 as a client for Samba?
17.1.2. How can I configure OS/2 Warp 3 (not Connect), + OS/2 1.2, 1.3 or 2.x for Samba?
17.1.3. Are there any other issues when OS/2 (any version) + is used as a client?
17.1.4. How do I get printer driver download working + for OS/2 clients?
18. HOWTO Access Samba source code via CVS
18.1. Introduction
18.2. CVS Access to samba.org
18.2.1. Access via CVSweb
18.2.2. Access via cvs
19. Reporting Bugs
19.1. Introduction
19.2. General info
19.3. Debug levels
19.4. Internal errors
19.5. Attaching to a running process
19.6. Patches
Index

Chapter 1. How to Install and Test SAMBA

1.1. Step 0: Read the man pages

The man pages distributed with SAMBA contain + lots of useful info that will help to get you started. + If you don't know how to read man pages then try + something like:

$ nroff -man smbd.8 | more +

Other sources of information are pointed to + by the Samba web site, http://www.samba.org

1.2. Step 1: Building the Binaries

To do this, first run the program ./configure + in the source directory. This should automatically + configure Samba for your operating system. If you have unusual + needs then you may wish to run

root# ./configure --help +

first to see what special options you can enable. + Then executing

root# make

will create the binaries. Once it's successfully + compiled you can use

root# make install

Your should get back a list of shares available on +>You should get back a list of shares available on your server. If you don't then something is incorrectly setup. Note that this method can also be used to see what shares are available on other LanManager clients (such as WfWg).

By default Samba uses a blank scope ID. This means all your windows boxes must also have a blank scope ID. If you really want to use a non-blank scope ID then you will - need to use the -i <scope> option to nmbd, smbd, and - smbclient. All your PCs will need to have the same setting for + need to use the 'netbios scope' smb.conf option. + All your PCs will need to have the same setting for this to work. I do not recommend scope IDs.

You can disable share modes using "share modes = no". - This may be useful on a heavily loaded server as the share - modes code is very slow. See also the FAST_SHARE_MODES - option in the Makefile for a way to do full share modes - very fast using shared memory (if your OS supports it).

1.10.6. Mapping Usernames

1.10.7. Other Character Sets

If you have problems using filenames with accented - characters in them (like the German, French or Scandinavian - character sets) then I recommend you look at the "valid chars" - option in smb.conf and also take a look at the validchars - package in the examples directory.

Chapter 2. Integrating MS Windows networks with SambaChapter 2. Diagnosing your samba server

2.1. Agenda2.1. Introduction

To identify the key functional mechanisms of MS Windows networking -to enable the deployment of Samba as a means of extending and/or -replacing MS Windows NT/2000 technology.

We will examine:

This file contains a list of tests you can perform to validate your +Samba server. It also tells you what the likely cause of the problem +is if it fails any one of these steps. If it passes all these tests +then it is probably working fine.

  1. You should do ALL the tests, in the order shown. I have tried to +carefully choose them so later tests only use capabilities verified in +the earlier tests.

    Name resolution in a pure Unix/Linux TCP/IP - environment -

  2. Name resolution as used within MS Windows - networking -

  3. How browsing functions and how to deploy stable - and dependable browsing using Samba -

  4. MS Windows security options and how to - configure Samba for seemless integration -

  5. Configuration of Samba as:

    1. A stand-alone server

    2. An MS Windows NT 3.x/4.0 security domain member -

    3. An alternative to an MS Windows NT 3.x/4.0 Domain Controller -

If you send me an email saying "it doesn't work" and you have not +followed this test procedure then you should not be surprised if I +ignore your email.

2.2. Name Resolution in a pure Unix/Linux world2.2. Assumptions

The key configuration files covered in this section are:

  • /etc/hosts

  • /etc/resolv.conf

  • /etc/host.conf

  • In all of the tests I assume you have a Samba server called BIGSERVER +and a PC called ACLIENT both in workgroup TESTGROUP. I also assume the +PC is running windows for workgroups with a recent copy of the +microsoft tcp/ip stack. Alternatively, your PC may be running Windows +95 or Windows NT (Workstation or Server).

    /etc/nsswitch.conf

2.2.1. /etc/hosts

The procedure is similar for other types of clients.

Contains a static list of IP Addresses and names. -eg:

I also assume you know the name of an available share in your +smb.conf. I will assume this share is called "tmp". You can add a +"tmp" share like by adding the following to smb.conf:

	127.0.0.1	localhost localhost.localdomain
-	192.168.1.1	bigbox.caldera.com	bigbox	alias4box
[tmp] + comment = temporary files + path = /tmp + read only = yes

The purpose of /etc/hosts is to provide a -name resolution mechanism so that uses do not need to remember -IP addresses.

THESE TESTS ASSUME VERSION 2.0.6 OR LATER OF THE SAMBA SUITE. SOME +COMMANDS SHOWN DID NOT EXIST IN EARLIER VERSIONS

Network packets that are sent over the physical network transport -layer communicate not via IP addresses but rather using the Media -Access Control address, or MAC address. IP Addresses are currently -32 bits in length and are typically presented as four (4) decimal -numbers that are separated by a dot (or period). eg: 168.192.1.1

Please pay attention to the error messages you receive. If any error message +reports that your server is being unfriendly you should first check that you +IP name resolution is correctly set up. eg: Make sure your /etc/resolv.conf +file points to name servers that really do exist.

MAC Addresses use 48 bits (or 6 bytes) and are typically represented -as two digit hexadecimal numbers separated by colons. eg: -40:8e:0a:12:34:56

Also, if you do not have DNS server access for name resolution please check +that the settings for your smb.conf file results in "dns proxy = no". The +best way to check this is with "testparm smb.conf"

2.3. Tests

2.3.1. Test 1

Every network interfrace must have an MAC address. Associated with -a MAC address there may be one or more IP addresses. There is NO -relationship between an IP address and a MAC address, all such assignments -are arbitary or discretionary in nature. At the most basic level all -network communications takes place using MAC addressing. Since MAC -addresses must be globally unique, and generally remains fixed for -any particular interface, the assignment of an IP address makes sense -from a network management perspective. More than one IP address can -be assigned per MAC address. One address must be the primary IP address, -this is the address that will be returned in the ARP reply.

In the directory in which you store your smb.conf file, run the command +"testparm smb.conf". If it reports any errors then your smb.conf +configuration file is faulty.

When a user or a process wants to communicate with another machine -the protocol implementation ensures that the "machine name" or "host -name" is resolved to an IP address in a manner that is controlled -by the TCP/IP configuration control files. The file -Note: Your smb.conf file may be located in: /etc/hosts is one such file.

When the IP address of the destination interface has been -determined a protocol called ARP/RARP isused to identify -the MAC address of the target interface. ARP stands for Address -Resolution Protocol, and is a broadcast oriented method that -uses UDP (User Datagram Protocol) to send a request to all -interfaces on the local network segment using the all 1's MAC -address. Network interfaces are programmed to respond to two -MAC addresses only; their own unique address and the address -ff:ff:ff:ff:ff:ff. The reply packet from an ARP request will -contain the MAC address and the primary IP address for each -interface.

The /etc + Or in: /etc/hosts file is foundational to all -Unix/Linux TCP/IP installations and as a minumum will contain -the localhost and local network interface IP addresses and the -primary names by which they are known within the local machine. -This file helps to prime the pump so that a basic level of name -resolution can exist before any other method of name resolution -becomes available.

/usr/local/samba/lib

2.2.2. /etc/resolv.conf2.3.2. Test 2

This file tells the name resolution libraries:

  • Run the command "ping BIGSERVER" from the PC and "ping ACLIENT" from +the unix box. If you don't get a valid response then your TCP/IP +software is not correctly installed.

    The name of the domain to which the machine - belongs -

  • Note that you will need to start a "dos prompt" window on the PC to +run ping.

    The name(s) of any domains that should be - automatically searched when trying to resolve unqualified - host names to their IP address -

  • If you get a message saying "host not found" or similar then your DNS +software or /etc/hosts file is not correctly setup. It is possible to +run samba without DNS entries for the server and client, but I assume +you do have correct entries for the remainder of these tests.

    The name or IP address of available Domain - Name Servers that may be asked to perform name to address - translation lookups -

Another reason why ping might fail is if your host is running firewall +software. You will need to relax the rules to let in the workstation +in question, perhaps by allowing access from another subnet (on Linux +this is done via the ipfwadm program.)

2.2.3. /etc/host.conf2.3.3. Test 3

/etc/host.conf is the primary means by -which the setting in /etc/resolv.conf may be affected. It is a -critical configuration file. This file controls the order by -which name resolution may procede. The typical structure is:

Run the command "smbclient -L BIGSERVER" on the unix box. You +should get a list of available shares back.

If you get a error message containing the string "Bad password" then +you probably have either an incorrect "hosts allow", "hosts deny" or +"valid users" line in your smb.conf, or your guest account is not +valid. Check what your guest account is using "testparm" and +temporarily remove any "hosts allow", "hosts deny", "valid users" or +"invalid users" lines.

If you get a "connection refused" response then the smbd server may +not be running. If you installed it in inetd.conf then you probably edited +that file incorrectly. If you installed it as a daemon then check that +it is running, and check that the netbios-ssn port is in a LISTEN +state using "netstat -a".

If you get a "session request failed" then the server refused the +connection. If it says "Your server software is being unfriendly" then +its probably because you have invalid command line parameters to smbd, +or a similar fatal problem with the initial startup of smbd. Also +check your config file (smb.conf) for syntax errors with "testparm" +and that the various directories where samba keeps its log and lock +files exist.

There are a number of reasons for which smbd may refuse or decline +a session request. The most common of these involve one or more of +the following smb.conf file entries:

	order hosts,bind
-	multi on
hosts deny = ALL + hosts allow = xxx.xxx.xxx.xxx/yy + bind interfaces only = Yes

then both addresses should be returned. Please refer to the -man page for host.conf for further details.

2.2.4. /etc/nsswitch.conf

This file controls the actual name resolution targets. The -file typically has resolver object specifications as follows:

In the above, no allowance has been made for any session requests that +will automatically translate to the loopback adaptor address 127.0.0.1. +To solve this problem change these lines to:

	# /etc/nsswitch.conf
-	#
-	# Name Service Switch configuration file.
-	#
-
-	passwd:		compat
-	# Alternative entries for password authentication are:
-	# passwd:	compat files nis ldap winbind
-	shadow:		compat
-	group:		compat
-
-	hosts:		files nis dns
-	# Alternative entries for host name resolution are:
-	# hosts:	files dns nis nis+ hesoid db compat ldap wins
-	networks:	nis files dns
-
-	ethers:		nis files
-	protocols:	nis files
-	rpc:		nis files
-	services:	nis files
hosts deny = ALL + hosts allow = xxx.xxx.xxx.xxx/yy 127.

Of course, each of these mechanisms requires that the appropriate -facilities and/or services are correctly configured.

Do NOT use the "bind interfaces only" parameter where you may wish to +use the samba password change facility, or where smbclient may need to +access local service for name resolution or for local resource +connections. (Note: the "bind interfaces only" parameter deficiency +where it will not allow connections to the loopback address will be +fixed soon).

It should be noted that unless a network request/message must be -sent, TCP/IP networks are silent. All TCP/IP communications assumes a -principal of speaking only when necessary.

Another common cause of these two errors is having something already running +on port 139, such as Samba (ie: smbd is running from inetd already) or +something like Digital's Pathworks. Check your inetd.conf file before trying +to start smbd as a daemon, it can avoid a lot of frustration!

Samba version 2.2.0 will add Linux support for extensions to -the name service switch infrastructure so that linux clients will -be able to obtain resolution of MS Windows NetBIOS names to IP -Addresses. To gain this functionality Samba needs to be compiled -with appropriate arguments to the make command (ie: make -nsswitch/libnss_wins.so). The resulting library should -then be installed in the /lib directory and -the "wins" parameter needs to be added to the "hosts:" line in -the /etc/nsswitch.conf file. At this point it -will be possible to ping any MS Windows machine by it's NetBIOS -machine name, so long as that machine is within the workgroup to -which both the samba machine and the MS Windows machine belong.

And yet another possible cause for failure of TEST 3 is when the subnet mask +and / or broadcast address settings are incorrect. Please check that the +network interface IP Address / Broadcast Address / Subnet Mask settings are +correct and that Samba has correctly noted these in the log.nmb file.

2.3. Name resolution as used within MS Windows networking

MS Windows networking is predicated about the name each machine -is given. This name is known variously (and inconsistently) as -the "computer name", "machine name", "networking name", "netbios name", -"SMB name". All terms mean the same thing with the exception of -"netbios name" which can apply also to the name of the workgroup or the -domain name. The terms "workgroup" and "domain" are really just a -simply name with which the machine is associated. All NetBIOS names -are exactly 16 characters in length. The 16th character is reserved. -It is used to store a one byte value that indicates service level -information for the NetBIOS name that is registered. A NetBIOS machine -name is therefore registered for each service type that is provided by -the client/server.

The following are typical NetBIOS name/service type registrations:

	Unique NetBIOS Names:
-		MACHINENAME<00>	= Server Service is running on MACHINENAME
-		MACHINENAME<03> = Generic Machine Name (NetBIOS name)
-		MACHINENAME<20> = LanMan Server service is running on MACHINENAME
-		WORKGROUP<1b> = Domain Master Browser
-
-	Group Names:
-		WORKGROUP<03> = Generic Name registered by all members of WORKGROUP
-		WORKGROUP<1c> = Domain Controllers / Netlogon Servers
-		WORKGROUP<1d> = Local Master Browsers
-		WORKGROUP<1e> = Internet Name Resolvers

It should be noted that all NetBIOS machines register their own -names as per the above. This is in vast contrast to TCP/IP -installations where traditionally the system administrator will -determine in the /etc/hosts or in the DNS database what names -are associated with each IP address.

One further point of clarification should be noted, the /etc/hosts -file and the DNS records do not provide the NetBIOS name type information -that MS Windows clients depend on to locate the type of service that may -be needed. An example of this is what happens when an MS Windows client -wants to locate a domain logon server. It find this service and the IP -address of a server that provides it by performing a lookup (via a -NetBIOS broadcast) for enumeration of all machines that have -registered the name type *<1c>. A logon request is then sent to each -IP address that is returned in the enumerated list of IP addresses. Which -ever machine first replies then ends up providing the logon services.

The name "workgroup" or "domain" really can be confusing since these -have the added significance of indicating what is the security -architecture of the MS Windows network. The term "workgroup" indicates -that the primary nature of the network environment is that of a -peer-to-peer design. In a WORKGROUP all machines are responsible for -their own security, and generally such security is limited to use of -just a password (known as SHARE MORE security). In most situations -with peer-to-peer networking the users who control their own machines -will simply opt to have no security at all. It is possible to have -USER MODE security in a WORKGROUP environment, thus requiring use -of a user name and a matching password.

MS Windows networking is thus predetermined to use machine names -for all local and remote machine message passing. The protocol used is -called Server Message Block (SMB) and this is implemented using -the NetBIOS protocol (Network Basic Input Output System). NetBIOS can -be encapsulated using LLC (Logical Link Control) protocol - in which case -the resulting protocol is called NetBEUI (Network Basic Extended User -Interface). NetBIOS can also be run over IPX (Internetworking Packet -Exchange) protocol as used by Novell NetWare, and it can be run -over TCP/IP protocols - in which case the resulting protocol is called -NBT or NetBT, the NetBIOS over TCP/IP.

MS Windows machines use a complex array of name resolution mechanisms. -Since we are primarily concerned with TCP/IP this demonstration is -limited to this area.

2.3.1. The NetBIOS Name Cache2.3.4. Test 4

All MS Windows machines employ an in memory buffer in which is -stored the NetBIOS names and their IP addresses for all external -machines that that the local machine has communicated with over the -past 10-15 minutes. It is more efficient to obtain an IP address -for a machine from the local cache than it is to go through all the -configured name resolution mechanisms.

Run the command "nmblookup -B BIGSERVER __SAMBA__". You should get the +IP address of your Samba server back.

If a machine whose name is in the local name cache has been shut -down before the name had been expired and flushed from the cache, then -an attempt to exchange a message with that machine will be subject -to time-out delays. ie: It's name is in the cache, so a name resolution -lookup will succeed, but the machine can not respond. This can be -frustrating for users - but it is a characteristic of the protocol.

If you don't then nmbd is incorrectly installed. Check your inetd.conf +if you run it from there, or that the daemon is running and listening +to udp port 137.

The MS Windows utility that allows examination of the NetBIOS -name cache is called "nbtstat". The Samba equivalent of this -is called "nmblookup".

One common problem is that many inetd implementations can't take many +parameters on the command line. If this is the case then create a +one-line script that contains the right parameters and run that from +inetd.

2.3.2. The LMHOSTS file2.3.5. Test 5

This file is usually located in MS Windows NT 4.0 or -2000 in C:\WINNT\SYSTEM32\DRIVERS\ETC and contains -the IP Address and the machine name in matched pairs. The -LMHOSTS file performs NetBIOS name -to IP address mapping oriented.

run the command nmblookup -B ACLIENT '*'

It typically looks like:

You should get the PCs IP address back. If you don't then the client +software on the PC isn't installed correctly, or isn't started, or you +got the name of the PC wrong. 

	# Copyright (c) 1998 Microsoft Corp.
-	#
-	# This is a sample LMHOSTS file used by the Microsoft Wins Client (NetBIOS
-	# over TCP/IP) stack for Windows98
-	#
-	# This file contains the mappings of IP addresses to NT computernames
-	# (NetBIOS) names.  Each entry should be kept on an individual line.
-	# The IP address should be placed in the first column followed by the
-	# corresponding computername. The address and the comptername
-	# should be separated by at least one space or tab. The "#" character
-	# is generally used to denote the start of a comment (see the exceptions
-	# below).
-	#
-	# This file is compatible with Microsoft LAN Manager 2.x TCP/IP lmhosts
-	# files and offers the following extensions:
-	#
-	#      #PRE
-	#      #DOM:<domain>
-	#      #INCLUDE <filename>
-	#      #BEGIN_ALTERNATE
-	#      #END_ALTERNATE
-	#      \0xnn (non-printing character support)
-	#
-	# Following any entry in the file with the characters "#PRE" will cause
-	# the entry to be preloaded into the name cache. By default, entries are
-	# not preloaded, but are parsed only after dynamic name resolution fails.
-	#
-	# Following an entry with the "#DOM:<domain>" tag will associate the
-	# entry with the domain specified by <domain>. This affects how the
-	# browser and logon services behave in TCP/IP environments. To preload
-	# the host name associated with #DOM entry, it is necessary to also add a
-	# #PRE to the line. The <domain> is always preloaded although it will not
-	# be shown when the name cache is viewed.
-	#
-	# Specifying "#INCLUDE <filename>" will force the RFC NetBIOS (NBT)
-	# software to seek the specified <filename> and parse it as if it were
-	# local. <filename> is generally a UNC-based name, allowing a
-	# centralized lmhosts file to be maintained on a server.
-	# It is ALWAYS necessary to provide a mapping for the IP address of the
-	# server prior to the #INCLUDE. This mapping must use the #PRE directive.
-	# In addtion the share "public" in the example below must be in the
-	# LanManServer list of "NullSessionShares" in order for client machines to
-	# be able to read the lmhosts file successfully. This key is under
-	# \machine\system\currentcontrolset\services\lanmanserver\parameters\nullsessionshares
-	# in the registry. Simply add "public" to the list found there.
-	#
-	# The #BEGIN_ and #END_ALTERNATE keywords allow multiple #INCLUDE
-	# statements to be grouped together. Any single successful include
-	# will cause the group to succeed.
-	#
-	# Finally, non-printing characters can be embedded in mappings by
-	# first surrounding the NetBIOS name in quotations, then using the
-	# \0xnn notation to specify a hex value for a non-printing character.
-	#
-	# The following example illustrates all of these extensions:
-	#
-	# 102.54.94.97     rhino         #PRE #DOM:networking  #net group's DC
-	# 102.54.94.102    "appname  \0x14"                    #special app server
-	# 102.54.94.123    popular            #PRE             #source server
-	# 102.54.94.117    localsrv           #PRE             #needed for the include
-	#
-	# #BEGIN_ALTERNATE
-	# #INCLUDE \\localsrv\public\lmhosts
-	# #INCLUDE \\rhino\public\lmhosts
-	# #END_ALTERNATE
-	#
-	# In the above example, the "appname" server contains a special
-	# character in its name, the "popular" and "localsrv" server names are
-	# preloaded, and the "rhino" server name is specified so it can be used
-	# to later #INCLUDE a centrally maintained lmhosts file if the "localsrv"
-	# system is unavailable.
-	#
-	# Note that the whole file is parsed including comments on each lookup,
-	# so keeping the number of comments to a minimum will improve performance.
-	# Therefore it is not advisable to simply add lmhosts file entries onto the
-	# end of this file.

If ACLIENT doesn't resolve via DNS then use the IP address of the +client in the above test.

2.3.3. HOSTS file2.3.6. Test 6

This file is usually located in MS Windows NT 4.0 or 2000 in -C:\WINNT\SYSTEM32\DRIVERS\ETC and contains -the IP Address and the IP hostname in matched pairs. It can be -used by the name resolution infrastructure in MS Windows, depending -on how the TCP/IP environment is configured. This file is in -every way the equivalent of the Unix/Linux /etc/hosts file.

2.3.4. DNS Lookup

Run the command nmblookup -d 2 '*'

This capability is configured in the TCP/IP setup area in the network -configuration facility. If enabled an elaborate name resolution sequence -is followed the precise nature of which isdependant on what the NetBIOS -Node Type parameter is configured to. A Node Type of 0 means use -NetBIOS broadcast (over UDP broadcast) is first used if the name -that is the subject of a name lookup is not found in the NetBIOS name -cache. If that fails then DNS, HOSTS and LMHOSTS are checked. If set to -Node Type 8, then a NetBIOS Unicast (over UDP Unicast) is sent to the -WINS Server to obtain a lookup before DNS, HOSTS, LMHOSTS, or broadcast -lookup is used.

This time we are trying the same as the previous test but are trying +it via a broadcast to the default broadcast address. A number of +Netbios/TCPIP hosts on the network should respond, although Samba may +not catch all of the responses in the short time it listens. You +should see "got a positive name query response" messages from several +hosts.

If this doesn't give a similar result to the previous test then +nmblookup isn't correctly getting your broadcast address through its +automatic mechanism. In this case you should experiment use the +"interfaces" option in smb.conf to manually configure your IP +address, broadcast and netmask.

If your PC and server aren't on the same subnet then you will need to +use the -B option to set the broadcast address to the that of the PCs +subnet.

This test will probably fail if your subnet mask and broadcast address are +not correct. (Refer to TEST 3 notes above).

2.3.5. WINS Lookup2.3.7. Test 7

A WINS (Windows Internet Name Server) service is the equivaent of the -rfc1001/1002 specified NBNS (NetBIOS Name Server). A WINS server stores -the names and IP addresses that are registered by a Windows client -if the TCP/IP setup has been given at least one WINS Server IP Address.

To configure Samba to be a WINS server the following parameter needs -to be added to the smb.conf file:

Run the command smbclient //BIGSERVER/TMP. You should +then be prompted for a password. You should use the password of the account +you are logged into the unix box with. If you want to test with +another account then add the -U >accountname< option to the end of +the command line. eg: +smbclient //bigserver/tmp -Ujohndoe

	wins support = Yes
Note: It is possible to specify the password along with the username +as follows: +smbclient //bigserver/tmp -Ujohndoe%secret

To configure Samba to use a WINS server the following parameters are -needed in the smb.conf file:

Once you enter the password you should get the "smb>" prompt. If you +don't then look at the error message. If it says "invalid network +name" then the service "tmp" is not correctly setup in your smb.conf.

If it says "bad password" then the likely causes are:

	wins support = No
-	wins server = xxx.xxx.xxx.xxx

  1. where xxx.xxx.xxx.xxx is the IP address -of the WINS server.

you have shadow passords (or some other password system) but didn't + compile in support for them in smbd +

  • your "valid users" configuration is incorrect +

  • you have a mixed case password and you haven't enabled the "password + level" option at a high enough level +

  • the "path =" line in smb.conf is incorrect. Check it with testparm +

  • you enabled password encryption but didn't create the SMB encrypted + password file +

    • Once connected you should be able to use the commands +dir get put etc. +Type help >command< for instructions. You should +especially check that the amount of free disk space shown is correct +when you type dir.

    2.4. How browsing functions and how to deploy stable and -dependable browsing using Samba

    2.3.8. Test 8

    As stated above, MS Windows machines register their NetBIOS names -(ie: the machine name for each service type in operation) on start -up. Also, as stated above, the exact method by which this name registration -takes place is determined by whether or not the MS Windows client/server -has been given a WINS server address, whether or not LMHOSTS lookup -is enabled, or if DNS for NetBIOS name resolution is enabled, etc.

    On the PC type the command net view \\BIGSERVER. You will +need to do this from within a "dos prompt" window. You should get back a +list of available shares on the server.

    In the case where there is no WINS server all name registrations as -well as name lookups are done by UDP broadcast. This isolates name -resolution to the local subnet, unless LMHOSTS is used to list all -names and IP addresses. In such situations Samba provides a means by -which the samba server name may be forcibly injected into the browse -list of a remote MS Windows network (using the "remote announce" parameter).

    If you get a "network name not found" or similar error then netbios +name resolution is not working. This is usually caused by a problem in +nmbd. To overcome it you could do one of the following (you only need +to choose one of them):

    Where a WINS server is used, the MS Windows client will use UDP -unicast to register with the WINS server. Such packets can be routed -and thus WINS allows name resolution to function across routed networks.

    1. During the startup process an election will take place to create a -local master browser if one does not already exist. On each NetBIOS network -one machine will be elected to function as the domain master browser. This -domain browsing has nothing to do with MS security domain control. -Instead, the domain master browser serves the role of contacting each local -master browser (found by asking WINS or from LMHOSTS) and exchanging browse -list contents. This way every master browser will eventually obtain a complete -list of all machines that are on the network. Every 11-15 minutes an election -is held to determine which machine will be the master browser. By nature of -the election criteria used, the machine with the highest uptime, or the -most senior protocol version, or other criteria, will win the election -as domain master browser.

      fixup the nmbd installation

    2. Clients wishing to browse the network make use of this list, but also depend -on the availability of correct name resolution to the respective IP -address/addresses.

      add the IP address of BIGSERVER to the "wins server" box in the + advanced tcp/ip setup on the PC.

    3. Any configuration that breaks name resolution and/or browsing intrinsics -will annoy users because they will have to put up with protracted -inability to use the network services.

      enable windows name resolution via DNS in the advanced section of + the tcp/ip setup

    4. Samba supports a feature that allows forced synchonisation -of browse lists across routed networks using the "remote -browse sync" parameter in the smb.conf file. This causes Samba -to contact the local master browser on a remote network and -to request browse list synchronisation. This effectively bridges -two networks that are separated by routers. The two remote -networks may use either broadcast based name resolution or WINS -based name resolution, but it should be noted that the "remote -browse sync" parameter provides browse list synchronisation - and -that is distinct from name to address resolution, in other -words, for cross subnet browsing to function correctly it is -essential that a name to address resolution mechanism be provided. -This mechanism could be via DNS, /etc/hosts, -and so on.

      add BIGSERVER to your lmhosts file on the PC.

    If you get a "invalid network name" or "bad password error" then the +same fixes apply as they did for the "smbclient -L" test above. In +particular, make sure your "hosts allow" line is correct (see the man +pages)

    Also, do not overlook that fact that when the workstation requests the +connection to the samba server it will attempt to connect using the +name with which you logged onto your Windows machine. You need to make +sure that an account exists on your Samba server with that exact same +name and password.

    If you get "specified computer is not receiving requests" or similar +it probably means that the host is not contactable via tcp services. +Check to see if the host is running tcp wrappers, and if so add an entry in +the hosts.allow file for your client (or subnet, etc.)

    2.3.9. Test 9

    Run the command net use x: \\BIGSERVER\TMP. You should +be prompted for a password then you should get a "command completed +successfully" message. If not then your PC software is incorrectly +installed or your smb.conf is incorrect. make sure your "hosts allow" +and other config lines in smb.conf are correct.

    It's also possible that the server can't work out what user name to +connect you as. To see if this is the problem add the line "user = +USERNAME" to the [tmp] section of smb.conf where "USERNAME" is the +username corresponding to the password you typed. If you find this +fixes things you may need the username mapping option.

    2.3.10. Test 10

    Run the command nmblookup -M TESTGROUP where +TESTGROUP is the name of the workgroup that your Samba server and +Windows PCs belong to. You should get back the IP address of the +master browser for that workgroup.

    If you don't then the election process has failed. Wait a minute to +see if it is just being slow then try again. If it still fails after +that then look at the browsing options you have set in smb.conf. Make +sure you have preferred master = yes to ensure that +an election is held at startup.

    2.3.11. Test 11

    From file manager try to browse the server. Your samba server should +appear in the browse list of your local workgroup (or the one you +specified in smb.conf). You should be able to double click on the name +of the server and get a list of shares. If you get a "invalid +password" error when you do then you are probably running WinNT and it +is refusing to browse a server that has no encrypted password +capability and is in user level security mode. In this case either set +security = server AND +password server = Windows_NT_Machine in your +smb.conf file, or enable encrypted passwords AFTER compiling in support +for encrypted passwords (refer to the Makefile).

    2.5. MS Windows security options and how to configure -Samba for seemless integration2.4. Still having troubles?

    MS Windows clients may use encrypted passwords as part of a -challenege/response authentication model (a.k.a. NTLMv1) or -alone, or clear text strings for simple password based -authentication. It should be realized that with the SMB -protocol the password is passed over the network either -in plain text or encrypted, but not both in the same -authentication requets.

    Try the mailing list or newsgroup, or use the ethereal utility to +sniff the problem. The official samba mailing list can be reached at +samba@samba.org. To find +out more about samba and how to subscribe to the mailing list check +out the samba web page at +http://samba.org/samba

    When encrypted passwords are used a password that has been -entered by the user is encrypted in two ways:

    Also look at the other docs in the Samba package!

    Chapter 3. Integrating MS Windows networks with Samba

    3.1. Agenda

    To identify the key functional mechanisms of MS Windows networking +to enable the deployment of Samba as a means of extending and/or +replacing MS Windows NT/2000 technology.

    We will examine:

      1. An MD4 hash of the UNICODE of the password - string. This is known as the NT hash. +>Name resolution in a pure Unix/Linux TCP/IP + environment

      2. The password is converted to upper case, - and then padded or trucated to 14 bytes. This string is - then appended with 5 bytes of NULL characters and split to - form two 56 bit DES keys to encrypt a "magic" 8 byte value. - The resulting 16 bytes for the LanMan hash. +>Name resolution as used within MS Windows + networking

  • You should refer to the Password Encryption chapter in this HOWTO collection -for more details on the inner workings

    How browsing functions and how to deploy stable + and dependable browsing using Samba +

  • MS Windows 95 pre-service pack 1, MS Windows NT versions 3.x -and version 4.0 pre-service pack 3 will use either mode of -password authentication. All versions of MS Windows that follow -these versions no longer support plain text passwords by default.

    MS Windows security options and how to + configure Samba for seemless integration +

  • MS Windows clients have a habit of dropping network mappings that -have been idle for 10 minutes or longer. When the user attempts to -use the mapped drive connection that has been dropped the SMB protocol -has a mechanism by which the connection can be re-established using -a cached copy of the password.

    Configuration of Samba as:

    When Microsoft changed the default password mode, they dropped support for -caching of the plain text password. This means that when the registry -parameter is changed to re-enable use of plain text passwords it appears to -work, but when a dropped mapping attempts to revalidate it will fail if -the remote authentication server does not support encrypted passwords. -This means that it is definitely not a good idea to re-enable plain text -password support in such clients.

    1. The following parameters can be used to work around the -issue of Windows 9x client upper casing usernames and -password before transmitting them to the SMB server -when using clear text authentication.

      A stand-alone server

    2. An MS Windows NT 3.x/4.0 security domain member +

    3. An alternative to an MS Windows NT 3.x/4.0 Domain Controller +

    • 3.2. Name Resolution in a pure Unix/Linux world

    The key configuration files covered in this section are:

    	passsword level = integer
-	username level = integer

    • By default Samba will lower case the username before attempting -to lookup the user in the database of local system accounts. -Because UNIX usernames conventionally only contain lower case -character, the username level parameter -is rarely even needed.

      /etc/hosts

    • However, password on UNIX systems often make use of mixed case -characters. This means that in order for a user on a Windows 9x -client to connect to a Samba server using clear text authentication, -the password level must be set to the maximum -number of upper case letter which could appear -is a password. Note that is the server OS uses the traditional -DES version of crypt(), then a password level -of 8 will result in case insensitive passwords as seen from Windows -users. This will also result in longer login times as Samba -hash to compute the permutations of the password string and -try them one by one until a match is located (or all combinations fail).

      /etc/resolv.conf

    • The best option to adopt is to enable support for encrypted passwords -where ever Samba is used. There are three configuration possibilities -for support of encrypted passwords:

      /etc/host.conf

    • /etc/nsswitch.conf

    2.5.1. Use MS Windows NT as an authentication server3.2.1. /etc/hosts

    This method involves the additions of the following parameters -in the smb.conf file:

    Contains a static list of IP Addresses and names. +eg:

    	encrypt passwords = Yes
-	security = server
-	password server = "NetBIOS_name_of_PDC"
    127.0.0.1 localhost localhost.localdomain + 192.168.1.1 bigbox.caldera.com bigbox alias4box

    There are two ways of identifying whether or not a username and -password pair was valid or not. One uses the reply information provided -as part of the authentication messaging process, the other uses -just and error code.

    The purpose of /etc/hosts is to provide a +name resolution mechanism so that uses do not need to remember +IP addresses.

    The down-side of this mode of configuration is the fact that -for security reasons Samba will send the password server a bogus -username and a bogus password and if the remote server fails to -reject the username and password pair then an alternative mode -of identification of validation is used. Where a site uses password -lock out after a certain number of failed authentication attempts -this will result in user lockouts.

    Network packets that are sent over the physical network transport +layer communicate not via IP addresses but rather using the Media +Access Control address, or MAC address. IP Addresses are currently +32 bits in length and are typically presented as four (4) decimal +numbers that are separated by a dot (or period). eg: 168.192.1.1

    Use of this mode of authentication does require there to be -a standard Unix account for the user, this account can be blocked -to prevent logons by other than MS Windows clients.

    MAC Addresses use 48 bits (or 6 bytes) and are typically represented +as two digit hexadecimal numbers separated by colons. eg: +40:8e:0a:12:34:56

    Every network interfrace must have an MAC address. Associated with +a MAC address there may be one or more IP addresses. There is NO +relationship between an IP address and a MAC address, all such assignments +are arbitary or discretionary in nature. At the most basic level all +network communications takes place using MAC addressing. Since MAC +addresses must be globally unique, and generally remains fixed for +any particular interface, the assignment of an IP address makes sense +from a network management perspective. More than one IP address can +be assigned per MAC address. One address must be the primary IP address, +this is the address that will be returned in the ARP reply.

    When a user or a process wants to communicate with another machine +the protocol implementation ensures that the "machine name" or "host +name" is resolved to an IP address in a manner that is controlled +by the TCP/IP configuration control files. The file +/etc/hosts is one such file.

    When the IP address of the destination interface has been +determined a protocol called ARP/RARP is used to identify +the MAC address of the target interface. ARP stands for Address +Resolution Protocol, and is a broadcast oriented method that +uses UDP (User Datagram Protocol) to send a request to all +interfaces on the local network segment using the all 1's MAC +address. Network interfaces are programmed to respond to two +MAC addresses only; their own unique address and the address +ff:ff:ff:ff:ff:ff. The reply packet from an ARP request will +contain the MAC address and the primary IP address for each +interface.

    The /etc/hosts file is foundational to all +Unix/Linux TCP/IP installations and as a minumum will contain +the localhost and local network interface IP addresses and the +primary names by which they are known within the local machine. +This file helps to prime the pump so that a basic level of name +resolution can exist before any other method of name resolution +becomes available.

    2.5.2. Make Samba a member of an MS Windows NT security domain3.2.2. /etc/resolv.conf

    This method involves additon of the following paramters in the smb.conf file:

    	encrypt passwords = Yes
-	security = domain
-	workgroup = "name of NT domain"
-	password server = *

    The use of the "*" argument to "password server" will cause samba -to locate the domain controller in a way analogous to the way -this is done within MS Windows NT.

    In order for this method to work the Samba server needs to join the -MS Windows NT security domain. This is done as follows:

    This file tells the name resolution libraries:

    • On the MS Windows NT domain controller using - the Server Manager add a machine account for the Samba server. +>The name of the domain to which the machine + belongs

    • Next, on the Linux system execute: - smbpasswd -r PDC_NAME -j DOMAIN_NAME +>The name(s) of any domains that should be + automatically searched when trying to resolve unqualified + host names to their IP address

    Use of this mode of authentication does require there to be -a standard Unix account for the user in order to assign -a uid once the account has been authenticated by the remote -Windows DC. This account can be blocked to prevent logons by -other than MS Windows clients by things such as setting an invalid -shell in the /etc/passwd entry.

  • An alternative to assigning UIDs to Windows users on a -Samba member server is presented in the Winbind Overview chapter in -this HOWTO collection.

    The name or IP address of available Domain + Name Servers that may be asked to perform name to address + translation lookups +

    • 2.5.3. Configure Samba as an authentication server3.2.3. /etc/host.conf

    This mode of authentication demands that there be on the -Unix/Linux system both a Unix style account as well as and -smbpasswd entry for the user. The Unix system account can be -locked if required as only the encrypted password will be -used for SMB client authentication.

    This method involves addition of the following parameters to -the smb.conf file:

    /etc/host.conf is the primary means by +which the setting in /etc/resolv.conf may be affected. It is a +critical configuration file. This file controls the order by +which name resolution may procede. The typical structure is:

    ## please refer to the Samba PDC HOWTO chapter later in 
-## this collection for more details
-[global]
-	encrypt passwords = Yes
-	security = user
-	domain logons = Yes
-	; an OS level of 33 or more is recommended
-	os level = 33
-
-[NETLOGON]
-	path = /somewhare/in/file/system
-	read only = yes
    order hosts,bind + multi on

    in order for this method to work a Unix system account needs -to be created for each user, as well as for each MS Windows NT/2000 -machine. The following structure is required.

    then both addresses should be returned. Please refer to the +man page for host.conf for further details.

    2.5.3.1. Users

    3.2.4. /etc/nsswitch.conf

    A user account that may provide a home directory should be -created. The following Linux system commands are typical of -the procedure for creating an account.

    This file controls the actual name resolution targets. The +file typically has resolver object specifications as follows:

    	# useradd -s /bin/bash -d /home/"userid" -m "userid"
-	# passwd "userid"
-	  Enter Password: <pw>
-	  
-	# smbpasswd -a "userid"
-	  Enter Password: <pw>
    # /etc/nsswitch.conf + # + # Name Service Switch configuration file. + # + + passwd: compat + # Alternative entries for password authentication are: + # passwd: compat files nis ldap winbind + shadow: compat + group: compat + + hosts: files nis dns + # Alternative entries for host name resolution are: + # hosts: files dns nis nis+ hesoid db compat ldap wins + networks: nis files dns + + ethers: nis files + protocols: nis files + rpc: nis files + services: nis files

    Of course, each of these mechanisms requires that the appropriate +facilities and/or services are correctly configured.

    It should be noted that unless a network request/message must be +sent, TCP/IP networks are silent. All TCP/IP communications assumes a +principal of speaking only when necessary.

    Samba version 2.2.0 will add Linux support for extensions to +the name service switch infrastructure so that linux clients will +be able to obtain resolution of MS Windows NetBIOS names to IP +Addresses. To gain this functionality Samba needs to be compiled +with appropriate arguments to the make command (ie: make +nsswitch/libnss_wins.so). The resulting library should +then be installed in the /lib directory and +the "wins" parameter needs to be added to the "hosts:" line in +the /etc/nsswitch.conf file. At this point it +will be possible to ping any MS Windows machine by it's NetBIOS +machine name, so long as that machine is within the workgroup to +which both the samba machine and the MS Windows machine belong.

    2.5.3.2. MS Windows NT Machine Accounts

    3.3. Name resolution as used within MS Windows networking

    These are required only when Samba is used as a domain -controller. Refer to the Samba-PDC-HOWTO for more details.

    MS Windows networking is predicated about the name each machine +is given. This name is known variously (and inconsistently) as +the "computer name", "machine name", "networking name", "netbios name", +"SMB name". All terms mean the same thing with the exception of +"netbios name" which can apply also to the name of the workgroup or the +domain name. The terms "workgroup" and "domain" are really just a +simply name with which the machine is associated. All NetBIOS names +are exactly 16 characters in length. The 16th character is reserved. +It is used to store a one byte value that indicates service level +information for the NetBIOS name that is registered. A NetBIOS machine +name is therefore registered for each service type that is provided by +the client/server.

    The following are typical NetBIOS name/service type registrations:

    	# useradd -s /bin/false -d /dev/null "machine_name"\$
-	# passwd -l "machine_name"\$
-	# smbpasswd -a -m "machine_name"
    Unique NetBIOS Names: + MACHINENAME<00> = Server Service is running on MACHINENAME + MACHINENAME<03> = Generic Machine Name (NetBIOS name) + MACHINENAME<20> = LanMan Server service is running on MACHINENAME + WORKGROUP<1b> = Domain Master Browser + + Group Names: + WORKGROUP<03> = Generic Name registered by all members of WORKGROUP + WORKGROUP<1c> = Domain Controllers / Netlogon Servers + WORKGROUP<1d> = Local Master Browsers + WORKGROUP<1e> = Internet Name Resolvers

    2.6. Conclusions

    Samba provides a flexible means to operate as...

    It should be noted that all NetBIOS machines register their own +names as per the above. This is in vast contrast to TCP/IP +installations where traditionally the system administrator will +determine in the /etc/hosts or in the DNS database what names +are associated with each IP address.

    MS Windows machines use a complex array of name resolution mechanisms. +Since we are primarily concerned with TCP/IP this demonstration is +limited to this area.

    Chapter 3. Configuring PAM for distributed but centrally -managed authentication

    3.3.1. The NetBIOS Name Cache

    All MS Windows machines employ an in memory buffer in which is +stored the NetBIOS names and IP addresses for all external +machines that that machine has communicated with over the +past 10-15 minutes. It is more efficient to obtain an IP address +for a machine from the local cache than it is to go through all the +configured name resolution mechanisms.

    If a machine whose name is in the local name cache has been shut +down before the name had been expired and flushed from the cache, then +an attempt to exchange a message with that machine will be subject +to time-out delays. i.e.: Its name is in the cache, so a name resolution +lookup will succeed, but the machine can not respond. This can be +frustrating for users - but it is a characteristic of the protocol.

    The MS Windows utility that allows examination of the NetBIOS +name cache is called "nbtstat". The Samba equivalent of this +is called "nmblookup".

    3.1. Samba and PAM

    3.3.2. The LMHOSTS file

    A number of Unix systems (eg: Sun Solaris), as well as the -xxxxBSD family and Linux, now utilize the Pluggable Authentication -Modules (PAM) facility to provide all authentication, -authorization and resource control services. Prior to the -introduction of PAM, a decision to use an alternative to -the system password database (This file is usually located in MS Windows NT 4.0 or +2000 in /etc/passwd) -would require the provision of alternatives for all programs that provide -security services. Such a choice would involve provision of -alternatives to such programs as: login, -passwd, chown, etc.

    C:\WINNT\SYSTEM32\DRIVERS\ETC and contains +the IP Address and the machine name in matched pairs. The +LMHOSTS file performs NetBIOS name +to IP address mapping oriented.

    PAM provides a mechanism that disconnects these security programs -from the underlying authentication/authorization infrastructure. -PAM is configured either through one file It typically looks like:

    	# Copyright (c) 1998 Microsoft Corp.
+	#
+	# This is a sample LMHOSTS file used by the Microsoft Wins Client (NetBIOS
+	# over TCP/IP) stack for Windows98
+	#
+	# This file contains the mappings of IP addresses to NT computernames
+	# (NetBIOS) names.  Each entry should be kept on an individual line.
+	# The IP address should be placed in the first column followed by the
+	# corresponding computername. The address and the comptername
+	# should be separated by at least one space or tab. The "#" character
+	# is generally used to denote the start of a comment (see the exceptions
+	# below).
+	#
+	# This file is compatible with Microsoft LAN Manager 2.x TCP/IP lmhosts
+	# files and offers the following extensions:
+	#
+	#      #PRE
+	#      #DOM:<domain>
+	#      #INCLUDE <filename>
+	#      #BEGIN_ALTERNATE
+	#      #END_ALTERNATE
+	#      \0xnn (non-printing character support)
+	#
+	# Following any entry in the file with the characters "#PRE" will cause
+	# the entry to be preloaded into the name cache. By default, entries are
+	# not preloaded, but are parsed only after dynamic name resolution fails.
+	#
+	# Following an entry with the "#DOM:<domain>" tag will associate the
+	# entry with the domain specified by <domain>. This affects how the
+	# browser and logon services behave in TCP/IP environments. To preload
+	# the host name associated with #DOM entry, it is necessary to also add a
+	# #PRE to the line. The <domain> is always preloaded although it will not
+	# be shown when the name cache is viewed.
+	#
+	# Specifying "#INCLUDE <filename>" will force the RFC NetBIOS (NBT)
+	# software to seek the specified <filename> and parse it as if it were
+	# local. <filename> is generally a UNC-based name, allowing a
+	# centralized lmhosts file to be maintained on a server.
+	# It is ALWAYS necessary to provide a mapping for the IP address of the
+	# server prior to the #INCLUDE. This mapping must use the #PRE directive.
+	# In addtion the share "public" in the example below must be in the
+	# LanManServer list of "NullSessionShares" in order for client machines to
+	# be able to read the lmhosts file successfully. This key is under
+	# \machine\system\currentcontrolset\services\lanmanserver\parameters\nullsessionshares
+	# in the registry. Simply add "public" to the list found there.
+	#
+	# The #BEGIN_ and #END_ALTERNATE keywords allow multiple #INCLUDE
+	# statements to be grouped together. Any single successful include
+	# will cause the group to succeed.
+	#
+	# Finally, non-printing characters can be embedded in mappings by
+	# first surrounding the NetBIOS name in quotations, then using the
+	# \0xnn notation to specify a hex value for a non-printing character.
+	#
+	# The following example illustrates all of these extensions:
+	#
+	# 102.54.94.97     rhino         #PRE #DOM:networking  #net group's DC
+	# 102.54.94.102    "appname  \0x14"                    #special app server
+	# 102.54.94.123    popular            #PRE             #source server
+	# 102.54.94.117    localsrv           #PRE             #needed for the include
+	#
+	# #BEGIN_ALTERNATE
+	# #INCLUDE \\localsrv\public\lmhosts
+	# #INCLUDE \\rhino\public\lmhosts
+	# #END_ALTERNATE
+	#
+	# In the above example, the "appname" server contains a special
+	# character in its name, the "popular" and "localsrv" server names are
+	# preloaded, and the "rhino" server name is specified so it can be used
+	# to later #INCLUDE a centrally maintained lmhosts file if the "localsrv"
+	# system is unavailable.
+	#
+	# Note that the whole file is parsed including comments on each lookup,
+	# so keeping the number of comments to a minimum will improve performance.
+	# Therefore it is not advisable to simply add lmhosts file entries onto the
+	# end of this file.

    3.3.3. HOSTS file

    This file is usually located in MS Windows NT 4.0 or 2000 in +/etc/pam.conf (Solaris), -or by editing individual files that are located in C:\WINNT\SYSTEM32\DRIVERS\ETC and contains +the IP Address and the IP hostname in matched pairs. It can be +used by the name resolution infrastructure in MS Windows, depending +on how the TCP/IP environment is configured. This file is in +every way the equivalent of the Unix/Linux /etc/pam.d.

    /etc/hosts file.

    3.3.4. DNS Lookup

    The following is an example /etc/pam.d/login configuration file. -This example had all options been uncommented is probably not usable -as it stacks many conditions before allowing successful completion -of the login process. Essentially all conditions can be disabled -by commenting them out except the calls to This capability is configured in the TCP/IP setup area in the network +configuration facility. If enabled an elaborate name resolution sequence +is followed the precise nature of which isdependant on what the NetBIOS +Node Type parameter is configured to. A Node Type of 0 means use +NetBIOS broadcast (over UDP broadcast) is first used if the name +that is the subject of a name lookup is not found in the NetBIOS name +cache. If that fails then DNS, HOSTS and LMHOSTS are checked. If set to +Node Type 8, then a NetBIOS Unicast (over UDP Unicast) is sent to the +WINS Server to obtain a lookup before DNS, HOSTS, LMHOSTS, or broadcast +lookup is used.

    3.3.5. WINS Lookup

    A WINS (Windows Internet Name Server) service is the equivaent of the +rfc1001/1002 specified NBNS (NetBIOS Name Server). A WINS server stores +the names and IP addresses that are registered by a Windows client +if the TCP/IP setup has been given at least one WINS Server IP Address.

    To configure Samba to be a WINS server the following parameter needs +to be added to the pam_pwdb.so.

    smb.conf file:

    #%PAM-1.0
-# The PAM configuration file for the `login' service
-#
-auth 		required	pam_securetty.so
-auth 		required	pam_nologin.so
-# auth 		required	pam_dialup.so
-# auth 		optional	pam_mail.so
-auth		required	pam_pwdb.so shadow md5
-# account    	requisite  	pam_time.so
-account		required	pam_pwdb.so
-session		required	pam_pwdb.so
-# session 	optional	pam_lastlog.so
-# password   	required   	pam_cracklib.so retry=3
-password	required	pam_pwdb.so shadow md5
    wins support = Yes

    PAM allows use of replacable modules. Those available on a -sample system include:

    To configure Samba to use a WINS server the following parameters are +needed in the smb.conf file:

    $ /bin/ls /lib/security
-pam_access.so    pam_ftp.so          pam_limits.so     
-pam_ncp_auth.so  pam_rhosts_auth.so  pam_stress.so     
-pam_cracklib.so  pam_group.so        pam_listfile.so   
-pam_nologin.so   pam_rootok.so       pam_tally.so      
-pam_deny.so      pam_issue.so        pam_mail.so       
-pam_permit.so    pam_securetty.so    pam_time.so       
-pam_dialup.so    pam_lastlog.so      pam_mkhomedir.so  
-pam_pwdb.so      pam_shells.so       pam_unix.so       
-pam_env.so       pam_ldap.so         pam_motd.so       
-pam_radius.so    pam_smbpass.so      pam_unix_acct.so  
-pam_wheel.so     pam_unix_auth.so    pam_unix_passwd.so
-pam_userdb.so    pam_warn.so         pam_unix_session.so
    wins support = No + wins server = xxx.xxx.xxx.xxx

    The following example for the login program replaces the use of -the pam_pwdb.so module which uses the system -password database (/etc/passwd, -/etc/shadow, /etc/group) with -the module pam_smbpass.so which uses the Samba -database which contains the Microsoft MD4 encrypted password -hashes. This database is stored in either -where xxx.xxx.xxx.xxx is the IP address +of the WINS server.

    3.4. How browsing functions and how to deploy stable and +dependable browsing using Samba

    As stated above, MS Windows machines register their NetBIOS names +(i.e.: the machine name for each service type in operation) on start +up. Also, as stated above, the exact method by which this name registration +takes place is determined by whether or not the MS Windows client/server +has been given a WINS server address, whether or not LMHOSTS lookup +is enabled, or if DNS for NetBIOS name resolution is enabled, etc.

    In the case where there is no WINS server all name registrations as +well as name lookups are done by UDP broadcast. This isolates name +resolution to the local subnet, unless LMHOSTS is used to list all +names and IP addresses. In such situations Samba provides a means by +which the samba server name may be forcibly injected into the browse +list of a remote MS Windows network (using the "remote announce" parameter).

    Where a WINS server is used, the MS Windows client will use UDP +unicast to register with the WINS server. Such packets can be routed +and thus WINS allows name resolution to function across routed networks.

    During the startup process an election will take place to create a +local master browser if one does not already exist. On each NetBIOS network +one machine will be elected to function as the domain master browser. This +domain browsing has nothing to do with MS security domain control. +Instead, the domain master browser serves the role of contacting each local +master browser (found by asking WINS or from LMHOSTS) and exchanging browse +list contents. This way every master browser will eventually obtain a complete +list of all machines that are on the network. Every 11-15 minutes an election +is held to determine which machine will be the master browser. By the nature of +the election criteria used, the machine with the highest uptime, or the +most senior protocol version, or other criteria, will win the election +as domain master browser.

    Clients wishing to browse the network make use of this list, but also depend +on the availability of correct name resolution to the respective IP +address/addresses.

    Any configuration that breaks name resolution and/or browsing intrinsics +will annoy users because they will have to put up with protracted +inability to use the network services.

    Samba supports a feature that allows forced synchonisation +of browse lists across routed networks using the "remote +browse sync" parameter in the smb.conf file. This causes Samba +to contact the local master browser on a remote network and +to request browse list synchronisation. This effectively bridges +two networks that are separated by routers. The two remote +networks may use either broadcast based name resolution or WINS +based name resolution, but it should be noted that the "remote +browse sync" parameter provides browse list synchronisation - and +that is distinct from name to address resolution, in other +words, for cross subnet browsing to function correctly it is +essential that a name to address resolution mechanism be provided. +This mechanism could be via DNS, /usr/local/samba/private/smbpasswd/etc/hosts, -/etc/samba/smbpasswd, or in -/etc/samba.d/smbpasswd, depending on the -Samba implementation for your Unix/Linux system. The -pam_smbpass.so module is provided by -Samba version 2.2.1 or later. It can be compiled by specifying the ---with-pam_smbpass options when running Samba's -configure script. For more information -on the pam_smbpass module, see the documentation -in the source/pam_smbpass directory of the Samba -source distribution.

    3.5. MS Windows security options and how to configure +Samba for seemless integration

    #%PAM-1.0
-# The PAM configuration file for the `login' service
-#
-auth		required	pam_smbpass.so nodelay
-account		required	pam_smbpass.so nodelay
-session		required	pam_smbpass.so nodelay
-password	required	pam_smbpass.so nodelay

    MS Windows clients may use encrypted passwords as part of a +challenege/response authentication model (a.k.a. NTLMv1) or +alone, or clear text strings for simple password based +authentication. It should be realized that with the SMB +protocol the password is passed over the network either +in plain text or encrypted, but not both in the same +authentication requets.

    The following is the PAM configuration file for a particular -Linux system. The default condition uses pam_pwdb.so.

    When encrypted passwords are used a password that has been +entered by the user is encrypted in two ways:

    #%PAM-1.0
-# The PAM configuration file for the `samba' service
-#
-auth       required     /lib/security/pam_pwdb.so nullok nodelay shadow audit
-account    required     /lib/security/pam_pwdb.so audit nodelay
-session    required     /lib/security/pam_pwdb.so nodelay
-password   required     /lib/security/pam_pwdb.so shadow md5

    You should refer to the Password Encryption chapter in this HOWTO collection +for more details on the inner workings

    MS Windows 95 pre-service pack 1, MS Windows NT versions 3.x +and version 4.0 pre-service pack 3 will use either mode of +password authentication. All versions of MS Windows that follow +these versions no longer support plain text passwords by default.

    MS Windows clients have a habit of dropping network mappings that +have been idle for 10 minutes or longer. When the user attempts to +use the mapped drive connection that has been dropped, the client +re-establishes the connection using +a cached copy of the password.

    When Microsoft changed the default password mode, they dropped support for +caching of the plain text password. This means that when the registry +parameter is changed to re-enable use of plain text passwords it appears to +work, but when a dropped mapping attempts to revalidate it will fail if +the remote authentication server does not support encrypted passwords. +This means that it is definitely not a good idea to re-enable plain text +password support in such clients.

    The following parameters can be used to work around the +issue of Windows 9x client upper casing usernames and +password before transmitting them to the SMB server +when using clear text authentication.

    #%PAM-1.0
-# The PAM configuration file for the `samba' service
-#
-auth       required     /lib/security/pam_smbpass.so nodelay
-account    required     /lib/security/pam_pwdb.so audit nodelay
-session    required     /lib/security/pam_pwdb.so nodelay
-password   required     /lib/security/pam_smbpass.so nodelay smbconf=/etc/samba.d/smb.conf
    passsword level = integer + username level = integer

    Note: PAM allows stacking of authentication mechanisms. It is -also possible to pass information obtained within on PAM module through -to the next module in the PAM stack. Please refer to the documentation for -your particular system implementation for details regarding the specific -capabilities of PAM in this environment. Some Linux implmentations also -provide the pam_stack.so module that allows all -authentication to be configured in a single central file. The -pam_stack.so method has some very devoted followers -on the basis that it allows for easier administration. As with all issues in -life though, every decision makes trade-offs, so you may want examine the -PAM documentation for further helpful information.

    3.2. Distributed Authentication

    The astute administrator will realize from this that the -combination of pam_smbpass.so, -winbindd, and rsync (see -http://rsync.samba.org/) -will allow the establishment of a centrally managed, distributed -user/password database that can also be used by all -PAM (eg: Linux) aware programs and applications. This arrangement -can have particularly potent advantages compared with the -use of Microsoft Active Directory Service (ADS) in so far as -reduction of wide area network authentication traffic.

    3.3. PAM Configuration in smb.conf

    There is an option in smb.conf called obey pam restrictions. -The following is from the on-line help for this option in SWAT;

    When Samba 2.2 is configure to enable PAM support (i.e. ---with-pam), this parameter will -control whether or not Samba should obey PAM's account -and session management directives. The default behavior -is to use PAM for clear text authentication only and to -ignore any account or session management. Note that Samba always -ignores PAM for authentication in the case of -encrypt passwords = yes. -The reason is that PAM modules cannot support the challenge/response -authentication mechanism needed in the presence of SMB -password encryption.

    Default: obey pam restrictions = no

    Chapter 4. Hosting a Microsoft Distributed File System tree on Samba

    4.1. Instructions

    The Distributed File System (or Dfs) provides a means of - separating the logical view of files and directories that users - see from the actual physical locations of these resources on the - network. It allows for higher availability, smoother storage expansion, - load balancing etc. For more information about Dfs, refer to Microsoft documentation.

    This document explains how to host a Dfs tree on a Unix - machine (for Dfs-aware clients to browse) using Samba.

    To enable SMB-based DFS for Samba, configure it with the - By default Samba will lower case the username before attempting +to lookup the user in the database of local system accounts. +Because UNIX usernames conventionally only contain lower case +character, the --with-msdfsusername level option. Once built, a - Samba server can be made a Dfs server by setting the global - boolean parameter +is rarely even needed.

    However, password on UNIX systems often make use of mixed case +characters. This means that in order for a user on a Windows 9x +client to connect to a Samba server using clear text authentication, +the host msdfspassword level parameter in the smb.conf - file. You designate a share as a Dfs root using the share - level boolean must be set to the maximum +number of upper case letter which could appear +is a password. Note that is the server OS uses the traditional +DES version of crypt(), then a msdfs rootpassword level parameter. A Dfs root directory on - Samba hosts Dfs links in the form of symbolic links that point - to other servers. For example, a symbolic link - junction->msdfs:storage1\share1 in - the share directory acts as the Dfs junction. When Dfs-aware - clients attempt to access the junction link, they are redirected - to the storage location (in this case, \\storage1\share1).

    +of 8 will result in case insensitive passwords as seen from Windows +users. This will also result in longer login times as Samba +hash to compute the permutations of the password string and +try them one by one until a match is located (or all combinations fail).

    Dfs trees on Samba work with all Dfs-aware clients ranging - from Windows 95 to 2000.

    The best option to adopt is to enable support for encrypted passwords +where ever Samba is used. There are three configuration possibilities +for support of encrypted passwords:

    3.5.1. Use MS Windows NT as an authentication server

    Here's an example of setting up a Dfs tree on a Samba - server.

    This method involves the additions of the following parameters +in the smb.conf file:

    # The smb.conf file:
-[global]
-	netbios name = SAMBA
-	host msdfs   = yes
-
-[dfs]
-	path = /export/dfsroot
-	msdfs root = yes
-
    encrypt passwords = Yes + security = server + password server = "NetBIOS_name_of_PDC"

    In the /export/dfsroot directory we set up our dfs links to - other servers on the network.

    There are two ways of identifying whether or not a username and +password pair was valid or not. One uses the reply information provided +as part of the authentication messaging process, the other uses +just and error code.

    root# cd /export/dfsroot

    The down-side of this mode of configuration is the fact that +for security reasons Samba will send the password server a bogus +username and a bogus password and if the remote server fails to +reject the username and password pair then an alternative mode +of identification of validation is used. Where a site uses password +lock out after a certain number of failed authentication attempts +this will result in user lockouts.

    root# chown root /export/dfsroot

    Use of this mode of authentication does require there to be +a standard Unix account for the user, this account can be blocked +to prevent logons by other than MS Windows clients.

    3.5.2. Make Samba a member of an MS Windows NT security domain

    root# chmod 755 /export/dfsroot

    This method involves additon of the following paramters in the smb.conf file:

    root# ln -s msdfs:storageA\\shareA linka
    	encrypt passwords = Yes
+	security = domain
+	workgroup = "name of NT domain"
+	password server = *

    root# ln -s msdfs:serverB\\share,serverC\\share linkbThe use of the "*" argument to "password server" will cause samba +to locate the domain controller in a way analogous to the way +this is done within MS Windows NT.

    In order for this method to work the Samba server needs to join the +MS Windows NT security domain. This is done as follows:

    • You should set up the permissions and ownership of - the directory acting as the Dfs root such that only designated - users can create, delete or modify the msdfs links. Also note - that symlink names should be all lowercase. This limitation exists - to have Samba avoid trying all the case combinations to get at - the link name. Finally set up the symbolic links to point to the - network shares you want, and start Samba.

      On the MS Windows NT domain controller using + the Server Manager add a machine account for the Samba server. +

    • Users on Dfs-aware clients can now browse the Dfs tree - on the Samba server at \\samba\dfs. Accessing - links linka or linkb (which appear as directories to the client) - takes users directly to the appropriate shares on the network.

      Next, on the Linux system execute: + smbpasswd -r PDC_NAME -j DOMAIN_NAME +

    Use of this mode of authentication does require there to be +a standard Unix account for the user in order to assign +a uid once the account has been authenticated by the remote +Windows DC. This account can be blocked to prevent logons by +other than MS Windows clients by things such as setting an invalid +shell in the /etc/passwd entry.

    An alternative to assigning UIDs to Windows users on a +Samba member server is presented in the Winbind Overview chapter in +this HOWTO collection.

    4.1.1. Notes3.5.3. Configure Samba as an authentication server

    This mode of authentication demands that there be on the +Unix/Linux system both a Unix style account as well as an +smbpasswd entry for the user. The Unix system account can be +locked if required as only the encrypted password will be +used for SMB client authentication.

    This method involves addition of the following parameters to +the smb.conf file:

    ## please refer to the Samba PDC HOWTO chapter later in 
+## this collection for more details
+[global]
+	encrypt passwords = Yes
+	security = user
+	domain logons = Yes
+	; an OS level of 33 or more is recommended
+	os level = 33
+
+[NETLOGON]
+	path = /somewhare/in/file/system
+	read only = yes

    in order for this method to work a Unix system account needs +to be created for each user, as well as for each MS Windows NT/2000 +machine. The following structure is required.

    3.5.3.1. Users

    A user account that may provide a home directory should be +created. The following Linux system commands are typical of +the procedure for creating an account.

    	# useradd -s /bin/bash -d /home/"userid" -m "userid"
+	# passwd "userid"
+	  Enter Password: <pw>
+	  
+	# smbpasswd -a "userid"
+	  Enter Password: <pw>

    3.5.3.2. MS Windows NT Machine Accounts

    These are required only when Samba is used as a domain +controller. Refer to the Samba-PDC-HOWTO for more details.

    	# useradd -s /bin/false -d /dev/null "machine_name"\$
+	# passwd -l "machine_name"\$
+	# smbpasswd -a -m "machine_name"

    3.6. Conclusions

    Samba provides a flexible means to operate as...

    • Windows clients need to be rebooted - if a previously mounted non-dfs share is made a dfs - root or vice versa. A better way is to introduce a - new share and make it the dfs root.

      A Stand-alone server - No special action is needed + other than to create user accounts. Stand-alone servers do NOT + provide network logon services, meaning that machines that use this + server do NOT perform a domain logon but instead make use only of + the MS Windows logon which is local to the MS Windows + workstation/server. +

    • Currently there's a restriction that msdfs - symlink names should all be lowercase.

      An MS Windows NT 3.x/4.0 security domain member. +

    • For security purposes, the directory - acting as the root of the Dfs tree should have ownership - and permissions set so that only designated users can - modify the symbolic links in the directory.

      An alternative to an MS Windows NT 3.x/4.0 + Domain Controller. +

    Chapter 5. UNIX Permission Bits and Windows NT Access Control ListsChapter 4. Configuring PAM for distributed but centrally +managed authentication

    5.1. Viewing and changing UNIX permissions using the NT - security dialogs4.1. Samba and PAM

    New in the Samba 2.0.4 release is the ability for Windows - NT clients to use their native security settings dialog box to - view and modify the underlying UNIX permissions.

    A number of Unix systems (eg: Sun Solaris), as well as the +xxxxBSD family and Linux, now utilize the Pluggable Authentication +Modules (PAM) facility to provide all authentication, +authorization and resource control services. Prior to the +introduction of PAM, a decision to use an alternative to +the system password database (/etc/passwd) +would require the provision of alternatives for all programs that provide +security services. Such a choice would involve provision of +alternatives to such programs as: login, +passwd, chown, etc.

    Note that this ability is careful not to compromise - the security of the UNIX host Samba is running on, and - still obeys all the file permission rules that a Samba - administrator can set.

    PAM provides a mechanism that disconnects these security programs +from the underlying authentication/authorization infrastructure. +PAM is configured either through one file /etc/pam.conf (Solaris), +or by editing individual files that are located in /etc/pam.d.

    In Samba 2.0.4 and above the default value of the - parameter nt acl supportThe following is an example /etc/pam.d/login configuration file. +This example had all options been uncommented is probably not usable +as it stacks many conditions before allowing successful completion +of the login process. Essentially all conditions can be disabled +by commenting them out except the calls to pam_pwdb.so.

    #%PAM-1.0
+# The PAM configuration file for the `login' service
+#
+auth 		required	pam_securetty.so
+auth 		required	pam_nologin.so
+# auth 		required	pam_dialup.so
+# auth 		optional	pam_mail.so
+auth		required	pam_pwdb.so shadow md5
+# account    	requisite  	pam_time.so
+account		required	pam_pwdb.so
+session		required	pam_pwdb.so
+# session 	optional	pam_lastlog.so
+# password   	required   	pam_cracklib.so retry=3
+password	required	pam_pwdb.so shadow md5

    PAM allows use of replacable modules. Those available on a +sample system include:

    $ /bin/ls /lib/security
+pam_access.so    pam_ftp.so          pam_limits.so     
+pam_ncp_auth.so  pam_rhosts_auth.so  pam_stress.so     
+pam_cracklib.so  pam_group.so        pam_listfile.so   
+pam_nologin.so   pam_rootok.so       pam_tally.so      
+pam_deny.so      pam_issue.so        pam_mail.so       
+pam_permit.so    pam_securetty.so    pam_time.so       
+pam_dialup.so    pam_lastlog.so      pam_mkhomedir.so  
+pam_pwdb.so      pam_shells.so       pam_unix.so       
+pam_env.so       pam_ldap.so         pam_motd.so       
+pam_radius.so    pam_smbpass.so      pam_unix_acct.so  
+pam_wheel.so     pam_unix_auth.so    pam_unix_passwd.so
+pam_userdb.so    pam_warn.so         pam_unix_session.so

    The following example for the login program replaces the use of +the pam_pwdb.so module which uses the system +password database (/etc/passwd, +/etc/shadow, /etc/group) with +the module pam_smbpass.so which uses the Samba +database which contains the Microsoft MD4 encrypted password +hashes. This database is stored in either +/usr/local/samba/private/smbpasswd, +/etc/samba/smbpasswd, or in +/etc/samba.d/smbpasswd, depending on the +Samba implementation for your Unix/Linux system. The +pam_smbpass.so module is provided by +Samba version 2.2.1 or later. It can be compiled by specifying the +--with-pam_smbpass options when running Samba's +configure script. For more information +on the pam_smbpass module, see the documentation +in the source/pam_smbpass directory of the Samba +source distribution.

    #%PAM-1.0
+# The PAM configuration file for the `login' service
+#
+auth		required	pam_smbpass.so nodelay
+account		required	pam_smbpass.so nodelay
+session		required	pam_smbpass.so nodelay
+password	required	pam_smbpass.so nodelay

    The following is the PAM configuration file for a particular +Linux system. The default condition uses pam_pwdb.so.

    #%PAM-1.0
+# The PAM configuration file for the `samba' service
+#
+auth       required     /lib/security/pam_pwdb.so nullok nodelay shadow audit
+account    required     /lib/security/pam_pwdb.so audit nodelay
+session    required     /lib/security/pam_pwdb.so nodelay
+password   required     /lib/security/pam_pwdb.so shadow md5

    In the following example the decision has been made to use the +smbpasswd database even for basic samba authentication. Such a +decision could also be made for the passwd program and would +thus allow the smbpasswd passwords to be changed using the passwd +program.

    #%PAM-1.0
+# The PAM configuration file for the `samba' service
+#
+auth       required     /lib/security/pam_smbpass.so nodelay
+account    required     /lib/security/pam_pwdb.so audit nodelay
+session    required     /lib/security/pam_pwdb.so nodelay
+password   required     /lib/security/pam_smbpass.so nodelay smbconf=/etc/samba.d/smb.conf

    Note: PAM allows stacking of authentication mechanisms. It is +also possible to pass information obtained within on PAM module through +to the next module in the PAM stack. Please refer to the documentation for +your particular system implementation for details regarding the specific +capabilities of PAM in this environment. Some Linux implmentations also +provide the pam_stack.so module that allows all +authentication to be configured in a single central file. The +pam_stack.so method has some very devoted followers +on the basis that it allows for easier administration. As with all issues in +life though, every decision makes trade-offs, so you may want examine the +PAM documentation for further helpful information.

    4.2. Distributed Authentication

    The astute administrator will realize from this that the +combination of pam_smbpass.so, +winbindd, and rsync (see +http://rsync.samba.org/) +will allow the establishment of a centrally managed, distributed +user/password database that can also be used by all +PAM (eg: Linux) aware programs and applications. This arrangement +can have particularly potent advantages compared with the +use of Microsoft Active Directory Service (ADS) in so far as +reduction of wide area network authentication traffic.

    4.3. PAM Configuration in smb.conf

    There is an option in smb.conf called obey pam restrictions. +The following is from the on-line help for this option in SWAT;

    When Samba 2.2 is configure to enable PAM support (i.e. +--with-pam), this parameter will +control whether or not Samba should obey PAM's account +and session management directives. The default behavior +is to use PAM for clear text authentication only and to +ignore any account or session management. Note that Samba always +ignores PAM for authentication in the case of +encrypt passwords = yes. +The reason is that PAM modules cannot support the challenge/response +authentication mechanism needed in the presence of SMB +password encryption.

    Default: obey pam restrictions = no

    Chapter 5. Hosting a Microsoft Distributed File System tree on Samba

    5.1. Instructions

    The Distributed File System (or Dfs) provides a means of + separating the logical view of files and directories that users + see from the actual physical locations of these resources on the + network. It allows for higher availability, smoother storage expansion, + load balancing etc. For more information about Dfs, refer to Microsoft documentation.

    This document explains how to host a Dfs tree on a Unix + machine (for Dfs-aware clients to browse) using Samba.

    To enable SMB-based DFS for Samba, configure it with the + --with-msdfs option. Once built, a + Samba server can be made a Dfs server by setting the global + boolean host msdfs parameter in the smb.conf + file. You designate a share as a Dfs root using the share + level boolean msdfs root parameter. A Dfs root directory on + Samba hosts Dfs links in the form of symbolic links that point + to other servers. For example, a symbolic link + junction->msdfs:storage1\share1 in + the share directory acts as the Dfs junction. When Dfs-aware + clients attempt to access the junction link, they are redirected + to the storage location (in this case, \\storage1\share1).

    Dfs trees on Samba work with all Dfs-aware clients ranging + from Windows 95 to 2000.

    Here's an example of setting up a Dfs tree on a Samba + server.

    # The smb.conf file:
+[global]
+	netbios name = SAMBA
+	host msdfs   = yes
+
+[dfs]
+	path = /export/dfsroot
+	msdfs root = yes
+

    In the /export/dfsroot directory we set up our dfs links to + other servers on the network.

    root# cd /export/dfsroot

    root# chown root /export/dfsroot

    root# chmod 755 /export/dfsroot

    root# ln -s msdfs:storageA\\shareA linka

    root# ln -s msdfs:serverB\\share,serverC\\share linkb

    You should set up the permissions and ownership of + the directory acting as the Dfs root such that only designated + users can create, delete or modify the msdfs links. Also note + that symlink names should be all lowercase. This limitation exists + to have Samba avoid trying all the case combinations to get at + the link name. Finally set up the symbolic links to point to the + network shares you want, and start Samba.

    Users on Dfs-aware clients can now browse the Dfs tree + on the Samba server at \\samba\dfs. Accessing + links linka or linkb (which appear as directories to the client) + takes users directly to the appropriate shares on the network.

    5.1.1. Notes

    • Windows clients need to be rebooted + if a previously mounted non-dfs share is made a dfs + root or vice versa. A better way is to introduce a + new share and make it the dfs root.

    • Currently there's a restriction that msdfs + symlink names should all be lowercase.

    • For security purposes, the directory + acting as the root of the Dfs tree should have ownership + and permissions set so that only designated users can + modify the symbolic links in the directory.

    Chapter 6. UNIX Permission Bits and Windows NT Access Control Lists

    6.1. Viewing and changing UNIX permissions using the NT + security dialogs

    New in the Samba 2.0.4 release is the ability for Windows + NT clients to use their native security settings dialog box to + view and modify the underlying UNIX permissions.

    Note that this ability is careful not to compromise + the security of the UNIX host Samba is running on, and + still obeys all the file permission rules that a Samba + administrator can set.

    In Samba 2.0.4 and above the default value of the + parameter nt acl support has been changed from false to true, so - manipulation of permissions is turned on by default.

    false to true, so + manipulation of permissions is turned on by default.

    6.2. How to view file security on a Samba share

    From an NT 4.0 client, single-click with the right + mouse button on any file or directory in a Samba mounted + drive letter or UNC path. When the menu pops-up, click + on the Properties entry at the bottom of + the menu. This brings up the normal file properties dialog + box, but with Samba 2.0.4 this will have a new tab along the top + marked Security. Click on this tab and you + will see three buttons, Permissions, + Auditing, and Ownership. + The Auditing button will cause either + an error message A requested privilege is not held + by the client to appear if the user is not the + NT Administrator, or a dialog which is intended to allow an + Administrator to add auditing requirements to a file if the + user is logged on as the NT Administrator. This dialog is + non-functional with a Samba share at this time, as the only + useful button, the Add button will not currently + allow a list of users to be seen.

    6.3. Viewing file ownership

    Clicking on the "Ownership" button + brings up a dialog box telling you who owns the given file. The + owner name will be of the form :

    "SERVER\user (Long name)"

    Where SERVER is the NetBIOS name of + the Samba server, user is the user name of + the UNIX user who owns the file, and (Long name) + is the descriptive string identifying the user (normally found in the + GECOS field of the UNIX password database). Click on the Close + button to remove this dialog.

    If the parameter nt acl support + is set to false then the file owner will + be shown as the NT user "Everyone".

    The Take Ownership button will not allow + you to change the ownership of this file to yourself (clicking on + it will display a dialog box complaining that the user you are + currently logged onto the NT client cannot be found). The reason + for this is that changing the ownership of a file is a privileged + operation in UNIX, available only to the root + user. As clicking on this button causes NT to attempt to change + the ownership of a file to the current user logged into the NT + client this will not work with Samba at this time.

    There is an NT chown command that will work with Samba + and allow a user with Administrator privilege connected + to a Samba 2.0.4 server as root to change the ownership of + files on both a local NTFS filesystem or remote mounted NTFS + or Samba drive. This is available as part of the Seclib + NT security library written by Jeremy Allison of + the Samba Team, available from the main Samba ftp site.

    6.4. Viewing file or directory permissions

    The third button is the "Permissions" + button. Clicking on this brings up a dialog box that shows both + the permissions and the UNIX owner of the file or directory. + The owner is displayed in the form :

    "SERVER\user (Long name)"

    Where SERVER is the NetBIOS name of + the Samba server, user is the user name of + the UNIX user who owns the file, and (Long name) + is the descriptive string identifying the user (normally found in the + GECOS field of the UNIX password database).

    If the parameter nt acl support + is set to false then the file owner will + be shown as the NT user "Everyone" and the + permissions will be shown as NT "Full Control".

    The permissions field is displayed differently for files + and directories, so I'll describe the way file permissions + are displayed first.

    6.4.1. File Permissions

    The standard UNIX user/group/world triple and + the corresponding "read", "write", "execute" permissions + triples are mapped by Samba into a three element NT ACL + with the 'r', 'w', and 'x' bits mapped into the corresponding + NT permissions. The UNIX world permissions are mapped into + the global NT group Everyone, followed + by the list of permissions allowed for UNIX world. The UNIX + owner and group permissions are displayed as an NT + user icon and an NT local + group icon respectively followed by the list + of permissions allowed for the UNIX user and group.

    As many UNIX permission sets don't map into common + NT names such as "read", "change" or "full control" then + usually the permissions will be prefixed by the words "Special Access" in the NT display list.

    But what happens if the file has no permissions allowed + for a particular UNIX user group or world component ? In order + to allow "no permissions" to be seen and modified then Samba + overloads the NT "Take Ownership" ACL attribute + (which has no meaning in UNIX) and reports a component with + no permissions as having the NT "O" bit set. + This was chosen of course to make it look like a zero, meaning + zero permissions. More details on the decision behind this will + be given below.

    6.4.2. Directory Permissions

    Directories on an NT NTFS file system have two + different sets of permissions. The first set of permissions + is the ACL set on the directory itself, this is usually displayed + in the first set of parentheses in the normal "RW" + NT style. This first set of permissions is created by Samba in + exactly the same way as normal file permissions are, described + above, and is displayed in the same way.

    The second set of directory permissions has no real meaning + in the UNIX permissions world and represents the "inherited" permissions that any file created within + this directory would inherit.

    Samba synthesises these inherited permissions for NT by + returning as an NT ACL the UNIX permission mode that a new file + created by Samba on this share would receive.

    6.5. Modifying file or directory permissions

    Modifying file and directory permissions is as simple + as changing the displayed permissions in the dialog box, and + clicking the OK button. However, there are + limitations that a user needs to be aware of, and also interactions + with the standard Samba permission masks and mapping of DOS + attributes that need to also be taken into account.

    If the parameter nt acl support + is set to false then any attempt to set + security permissions will fail with an "Access Denied" + message.

    The first thing to note is that the "Add" + button will not return a list of users in Samba 2.0.4 (it will give + an error message of "The remote procedure call failed + and did not execute"). This means that you can only + manipulate the current user/group/world permissions listed in + the dialog box. This actually works quite well as these are the + only permissions that UNIX actually has.

    If a permission triple (either user, group, or world) + is removed from the list of permissions in the NT dialog box, + then when the "OK" button is pressed it will + be applied as "no permissions" on the UNIX side. If you then + view the permissions again the "no permissions" entry will appear + as the NT "O" flag, as described above. This + allows you to add permissions back to a file or directory once + you have removed them from a triple component.

    As UNIX supports only the "r", "w" and "x" bits of + an NT ACL then if other NT security attributes such as "Delete + access" are selected then they will be ignored when applied on + the Samba server.

    When setting permissions on a directory the second + set of permissions (in the second set of parentheses) is + by default applied to all files within that directory. If this + is not what you want you must uncheck the "Replace + permissions on existing files" checkbox in the NT + dialog before clicking "OK".

    If you wish to remove all permissions from a + user/group/world component then you may either highlight the + component and click the "Remove" button, + or set the component to only have the special "Take + Ownership" permission (displayed as "O" + ) highlighted.

    6.6. Interaction with the standard Samba create mask + parameters

    Note that with Samba 2.0.5 there are four new parameters + to control this interaction. These are :

    security mask

    force security mode

    directory security mask

    force directory security mode

    Once a user clicks "OK" to apply the + permissions Samba maps the given permissions into a user/group/world + r/w/x triple set, and then will check the changed permissions for a + file against the bits set in the + security mask parameter. Any bits that + were changed that are not set to '1' in this parameter are left alone + in the file permissions.

    Essentially, zero bits in the security mask + mask may be treated as a set of bits the user is not + allowed to change, and one bits are those the user is allowed to change. +

    If not set explicitly this parameter is set to the same value as + the create mask + parameter to provide compatibility with Samba 2.0.4 + where this permission change facility was introduced. To allow a user to + modify all the user/group/world permissions on a file, set this parameter + to 0777.

    Next Samba checks the changed permissions for a file against + the bits set in the force security mode parameter. Any bits + that were changed that correspond to bits set to '1' in this parameter + are forced to be set.

    Essentially, bits set in the force security mode + parameter may be treated as a set of bits that, when + modifying security on a file, the user has always set to be 'on'.

    If not set explicitly this parameter is set to the same value + as the force + create mode parameter to provide compatibility + with Samba 2.0.4 where the permission change facility was introduced. + To allow a user to modify all the user/group/world permissions on a file + with no restrictions set this parameter to 000.

    The security mask and force + security mode parameters are applied to the change + request in that order.

    For a directory Samba will perform the same operations as + described above for a file except using the parameter directory security mask instead of security + mask, and force directory security mode + parameter instead of force security mode + .

    The directory security mask parameter + by default is set to the same value as the directory mask + parameter and the force directory security + mode parameter by default is set to the same value as + the force directory mode parameter to provide + compatibility with Samba 2.0.4 where the permission change facility + was introduced.

    In this way Samba enforces the permission restrictions that + an administrator can set on a Samba share, whilst still allowing users + to modify the permission bits within that restriction.

    If you want to set up a share that allows users full control + in modifying the permission bits on their files and directories and + doesn't force any particular bits to be set 'on', then set the following + parameters in the smb.conf(5) + file in that share specific section :

    security mask = 0777

    force security mode = 0

    directory security mask = 0777

    force directory security mode = 0

    As described, in Samba 2.0.4 the parameters :

    create mask

    force create mode

    directory mask

    force directory mode

    were used instead of the parameters discussed here.

    6.7. Interaction with the standard Samba file attribute + mapping

    Samba maps some of the DOS attribute bits (such as "read + only") into the UNIX permissions of a file. This means there can + be a conflict between the permission bits set via the security + dialog and the permission bits set by the file attribute mapping. +

    One way this can show up is if a file has no UNIX read access + for the owner it will show up as "read only" in the standard + file attributes tabbed dialog. Unfortunately this dialog is + the same one that contains the security info in another tab.

    What this can mean is that if the owner changes the permissions + to allow themselves read access using the security dialog, clicks + "OK" to get back to the standard attributes tab + dialog, and then clicks "OK" on that dialog, then + NT will set the file permissions back to read-only (as that is what + the attributes still say in the dialog). This means that after setting + permissions and clicking "OK" to get back to the + attributes dialog you should always hit "Cancel" + rather than "OK" to ensure that your changes + are not overridden.

    Chapter 7. Printing Support in Samba 2.2.x

    7.1. Introduction

    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.

    The additional functionality provided by the new +SPOOLSS support includes:

    • Support for downloading printer driver + files to Windows 95/98/NT/2000 clients upon demand. +

    • Uploading of printer drivers via the + Windows NT Add Printer Wizard (APW) or the + Imprints tool set (refer to http://imprints.sourceforge.net). +

    • Support for the native MS-RPC printing + calls such as StartDocPrinter, EnumJobs(), etc... (See + the MSDN documentation at http://msdn.microsoft.com/ + for more information on the Win32 printing API) +

    • Support for NT Access Control Lists (ACL) + on printer objects

    • Improved support for printer queue manipulation + through the use of an internal databases for spooled job + information

    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.

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

    http://support.microsoft.com/support/kb/articles/Q189/1/05.ASP

    7.2. Configuration

    [print$] vs. [printer$]

    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.

    However, the initial implementation allowed for a +parameter named printer driver location +to be used on a per share basis to specify the location of +the driver files associated with that printer. Another +parameter named printer driver provided +a means of defining the printer driver name to be sent to +the client.

    These parameters, including printer driver +file parameter, are being depreciated and should not +be used in new installations. For more information on this change, +you should refer to the Migration section +of this document.

    7.2.1. Creating [print$]

    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).

    You should modify the server's smb.conf file to add the global +parameters and 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):

    [global]
+    ; members of the ntadmin group should be able
+    ; to add drivers and set printer properties
+    ; root is implicitly a 'printer admin'
+    printer admin = @ntadmin
+
+[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,root

    The write list is used to allow administrative +level user accounts to have write access in order to update files +on the share. See the smb.conf(5) +man page for more information on configuring file shares.

    The requirement for guest +ok = yes 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.

    Author's Note: 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 map to guest = Bad User in the [global] section as well. Make sure +you understand what this parameter does before using it +though. --jerry

    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.

    Next create the directory tree below the [print$] share +for each architecture you wish to support.

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

    ATTENTION! REQUIRED PERMISSIONS

    In order to currently add a new driver to you Samba host, +one of two conditions must hold true:

    • The account used to connect to the Samba host + must have a uid of 0 (i.e. a root account)

    • The account used to connect to the Samba host + must be a member of the printer + admin list.

    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.

    Once you have created the required [print$] service and +associated subdirectories, simply log onto the Samba server using +a root (or printer admin) account +from a Windows NT 4.0/2k client. Open "Network Neighbourhood" or +"My Network Places" and browse for the Samba host. Once you have located +the server, navigate to the "Printers..." folder. +You should see an initial listing of printers +that matches the printer shares defined on your Samba host.

    7.2.2. Setting Drivers for Existing Printers

    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 +NO PRINTER DRIVER AVAILABLE FOR THIS PRINTER. +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:

    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?

    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

    • Use the "New Driver..." button to install + a new printer driver, or

    • Select a driver from the popup list of + installed drivers. Initially this list will be empty.

    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.

    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.

    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 +smb.conf.

    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.

    7.2.3. Support a large number of printers

    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 rpcclient's +setdriver command can be used to set the driver +associated with an installed driver. The following is example +of how this could be accomplished:

     
+$ 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]
+				  
+$ 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:[]
+				  
+$ rpcclient pogo -U root%secret \
+>  -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.

    7.2.4. Adding New Printers via the Windows NT APW

    By default, Samba offers all printer shares defined in smb.conf +in the "Printers..." folder. Also existing in this folder is the Windows NT +Add Printer Wizard icon. The APW will be show only if

    • The connected user is able to successfully + execute an OpenPrinterEx(\\server) with administrative + privileges (i.e. root or printer admin). +

    • show + add printer wizard = yes (the default). +

    In order to be able to use the APW to successfully add a printer to a Samba +server, the add +printer command must have a defined value. The program +hook must successfully add the printer to the system (i.e. +/etc/printcap or appropriate files) and +smb.conf if necessary.

    When using the APW from a client, if the named printer share does +not exist, smbd will execute the add printer +command and reparse to the smb.conf +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 +add printer program is executed under the context +of the connected user, not necessarily a root account.

    There is a complementing delete +printer command for removing entries from the "Printers..." +folder.

    7.2.5. Samba and Printer Ports

    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.

    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.

    If you require that multiple ports be defined for some reason, +smb.conf possesses a enumports +command which can be used to define an external program +that generates a listing of ports on a system.

    7.3. The Imprints Toolset

    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 http://imprints.sourceforge.net/ as well as the documentation + included with the imprints source distribution. This section will + only provide a brief introduction to the features of Imprints.

    7.3.1. What is Imprints?

    Imprints is a collection of tools for supporting the goals + of

    • Providing a central repository information + regarding Windows NT and 95/98 printer driver packages

    • Providing the tools necessary for creating + the Imprints printer driver packages.

    • Providing an installation client which + will obtain and install printer drivers on remote Samba + and Windows NT 4 print servers.

    7.3.2. Creating Printer Driver Packages

    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.

    7.3.3. The Imprints server

    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 + not recommended that this security check + be disabled.

    7.3.4. The Installation Client

    More information regarding the Imprints installation client + is available in the Imprints-Client-HOWTO.ps + file included with the imprints source package.

    The Imprints installation client comes in two forms.

    • a set of command line Perl scripts

    • a GTK+ based graphical interface to + the command line perl scripts

    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.

    The basic installation process is in four steps and + perl code is wrapped around smbclient + and rpcclient.

    	
+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

    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 calls its version of this driver "Apple + LaserWriter II NTX"

    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

    HKLM\System\CurrentControlSet\Control\Print\Environment +

    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?

    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.

    7.4. Migration to from Samba 2.0.x to 2.2.x

    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. Here are the possible scenarios for +migration:

    • If you do not desire the new Windows NT + print driver support, nothing needs to be done. + All existing parameters work the same.

    • 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 make_printerdef + tool will also remain for backwards compatibility but will + be removed in the next major release.

    • 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).

    • If you want to migrate an existing printers.def + 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 smbclient and rpcclient. See the + Imprints installation client at http://imprints.sourceforge.net/ + for an example. +

    Achtung!

    The following smb.conf parameters are considered to +be deprecated and will be removed soon. Do not use them in new +installations

    • printer driver file (G) +

    • printer driver (S) +

    • printer driver location (S) +

    The have been two new parameters add in Samba 2.2.2 to for +better support of Samba 2.0.x backwards capability (disable +spoolss) and for using local printers drivers on Windows +NT/2000 clients (use client driver). Both of +these options are described in the smb.coinf(5) man page and are +disabled by default.

    Chapter 8. Debugging Printing Problems

    8.1. Introduction

    This is a short description of how to debug printing problems with +Samba. This describes how to debug problems with printing from a SMB +client to a Samba server, not the other way around. For the reverse +see the examples/printing directory.

    Ok, so you want to print to a Samba server from your PC. The first +thing you need to understand is that Samba does not actually do any +printing itself, it just acts as a middleman between your PC client +and your Unix printing subsystem. Samba receives the file from the PC +then passes the file to a external "print command". What print command +you use is up to you.

    The whole things is controlled using options in smb.conf. The most +relevant options (which you should look up in the smb.conf man page) +are:

          [global]
+        print command     - send a file to a spooler
+        lpq command       - get spool queue status
+        lprm command      - remove a job
+      [printers]
+        path = /var/spool/lpd/samba

    The following are nice to know about:

            queuepause command   - stop a printer or print queue
+        queueresume command  - start a printer or print queue

    Example:

            print command = /usr/bin/lpr -r -P%p %s
+        lpq command   = /usr/bin/lpq    -P%p %s
+        lprm command  = /usr/bin/lprm   -P%p %j
+        queuepause command = /usr/sbin/lpc -P%p stop
+        queuepause command = /usr/sbin/lpc -P%p start

    Samba should set reasonable defaults for these depending on your +system type, but it isn't clairvoyant. It is not uncommon that you +have to tweak these for local conditions. The commands should +always have fully specified pathnames, as the smdb may not have +the correct PATH values.

    When you send a job to Samba to be printed, it will make a temporary +copy of it in the directory specified in the [printers] section. +and it should be periodically cleaned out. The lpr -r option +requests that the temporary copy be removed after printing; If +printing fails then you might find leftover files in this directory, +and it should be periodically cleaned out. Samba used the lpq +command to determine the "job number" assigned to your print job +by the spooler.

    The %>letter< are "macros" that get dynamically replaced with appropriate +values when they are used. The %s gets replaced with the name of the spool +file that Samba creates and the %p gets replaced with the name of the +printer. The %j gets replaced with the "job number" which comes from +the lpq output.

    5.2. How to view file security on a Samba share8.2. Debugging printer problems

    From an NT 4.0 client, single-click with the right - mouse button on any file or directory in a Samba mounted - drive letter or UNC path. When the menu pops-up, click - on the Properties entry at the bottom of - the menu. This brings up the normal file properties dialog - box, but with Samba 2.0.4 this will have a new tab along the top - marked Security. Click on this tab and you - will see three buttons, Permissions, - Auditing, and Ownership. - The Auditing button will cause either - an error message A requested privilege is not held - by the client to appear if the user is not the - NT Administrator, or a dialog which is intended to allow an - Administrator to add auditing requirements to a file if the - user is logged on as the NT Administrator. This dialog is - non-functional with a Samba share at this time, as the only - useful button, the Add button will not currently - allow a list of users to be seen.

    One way to debug printing problems is to start by replacing these +command with shell scripts that record the arguments and the contents +of the print file. A simple example of this kind of things might +be:

    	print command = /tmp/saveprint %p %s
+
+    #!/bin/saveprint
+    # we make sure that we are the right user
+    /usr/bin/id -p >/tmp/tmp.print
+    # we run the command and save the error messages
+    # replace the command with the one appropriate for your system
+    /usr/bin/lpr -r -P$1 $2 2>>&/tmp/tmp.print

    Then you print a file and try removing it. You may find that the +print queue needs to be stopped in order to see the queue status +and remove the job:

    
h4: {42} % echo hi >/tmp/hi
+h4: {43} % smbclient //localhost/lw4
+added interface ip=10.0.0.4 bcast=10.0.0.255 nmask=255.255.255.0
+Password: 
+Domain=[ASTART] OS=[Unix] Server=[Samba 2.0.7]
+smb: \> print /tmp/hi
+putting file /tmp/hi as hi-17534 (0.0 kb/s) (average 0.0 kb/s)
+smb: \> queue
+1049     3            hi-17534
+smb: \> cancel 1049
+Error cancelling job 1049 : code 0
+smb: \> cancel 1049
+Job 1049 cancelled
+smb: \> queue
+smb: \> exit

    The 'code 0' indicates that the job was removed. The comment +by the smbclient is a bit misleading on this. +You can observe the command output and then and look at the +/tmp/tmp.print file to see what the results are. You can quickly +find out if the problem is with your printing system. Often people +have problems with their /etc/printcap file or permissions on +various print queues.

    5.3. Viewing file ownership8.3. What printers do I have?

    Clicking on the "Ownership" button - brings up a dialog box telling you who owns the given file. The - owner name will be of the form :

    You can use the 'testprns' program to check to see if the printer +name you are using is recognized by Samba. For example, you can +use:

    "SERVER\user (Long name)"
        testprns printer /etc/printcap

    Where SERVER is the NetBIOS name of - the Samba server, user is the user name of - the UNIX user who owns the file, and (Long name) - is the descriptive string identifying the user (normally found in the - GECOS field of the UNIX password database). Click on the Close - button to remove this dialog.

    Samba can get its printcap information from a file or from a program. +You can try the following to see the format of the extracted +information:

    If the parameter nt acl support - is set to false then the file owner will - be shown as the NT user "Everyone".

        testprns -a printer /etc/printcap
+
+    testprns -a printer '|/bin/cat printcap'

    8.4. Setting up printcap and print servers

    The Take Ownership button will not allow - you to change the ownership of this file to yourself (clicking on - it will display a dialog box complaining that the user you are - currently logged onto the NT client cannot be found). The reason - for this is that changing the ownership of a file is a privileged - operation in UNIX, available only to the root - user. As clicking on this button causes NT to attempt to change - the ownership of a file to the current user logged into the NT - client this will not work with Samba at this time.

    You may need to set up some printcaps for your Samba system to use. +It is strongly recommended that you use the facilities provided by +the print spooler to set up queues and printcap information.

    There is an NT chown command that will work with Samba - and allow a user with Administrator privilege connected - to a Samba 2.0.4 server as root to change the ownership of - files on both a local NTFS filesystem or remote mounted NTFS - or Samba drive. This is available as part of the Seclib - NT security library written by Jeremy Allison of - the Samba Team, available from the main Samba ftp site.

    Samba requires either a printcap or program to deliver printcap +information. This printcap information has the format:

      name|alias1|alias2...:option=value:...

    For almost all printing systems, the printer 'name' must be composed +only of alphanumeric or underscore '_' characters. Some systems also +allow hyphens ('-') as well. An alias is an alternative name for the +printer, and an alias with a space in it is used as a 'comment' +about the printer. The printcap format optionally uses a \ at the end of lines +to extend the printcap to multiple lines.

    Here are some examples of printcap files:

    1. pr just printer name

    2. pr|alias printer name and alias

    3. pr|My Printer printer name, alias used as comment

    4. pr:sh:\ Same as pr:sh:cm= testing + :cm= \ + testing

    5. pr:sh Same as pr:sh:cm= testing + :cm= testing

    Samba reads the printcap information when first started. If you make +changes in the printcap information, then you must do the following:

    1. make sure that the print spooler is aware of these changes. +The LPRng system uses the 'lpc reread' command to do this.

    2. make sure that the spool queues, etc., exist and have the +correct permissions. The LPRng system uses the 'checkpc -f' +command to do this.

    3. You now should send a SIGHUP signal to the smbd server to have +it reread the printcap information.

    8.5. Job sent, no output

    This is the most frustrating part of printing. You may have sent the +job, verified that the job was forwarded, set up a wrapper around +the command to send the file, but there was no output from the printer.

    First, check to make sure that the job REALLY is getting to the +right print queue. If you are using a BSD or LPRng print spooler, +you can temporarily stop the printing of jobs. Jobs can still be +submitted, but they will not be printed. Use:

      lpc -Pprinter stop

    Now submit a print job and then use 'lpq -Pprinter' to see if the +job is in the print queue. If it is not in the print queue then +you will have to find out why it is not being accepted for printing.

    Next, you may want to check to see what the format of the job really +was. With the assistance of the system administrator you can view +the submitted jobs files. You may be surprised to find that these +are not in what you would expect to call a printable format. +You can use the UNIX 'file' utitily to determine what the job +format actually is:

        cd /var/spool/lpd/printer   # spool directory of print jobs
+    ls                          # find job files
+    file dfA001myhost

    You should make sure that your printer supports this format OR that +your system administrator has installed a 'print filter' that will +convert the file to a format appropriate for your printer.

    5.4. Viewing file or directory permissions8.6. Job sent, strange output

    The third button is the "Permissions" - button. Clicking on this brings up a dialog box that shows both - the permissions and the UNIX owner of the file or directory. - The owner is displayed in the form :

    Once you have the job printing, you can then start worrying about +making it print nicely.

    "SERVER\user (Long name)"

    The most common problem is extra pages of output: banner pages +OR blank pages at the end.

    Where SERVER is the NetBIOS name of - the Samba server, user is the user name of - the UNIX user who owns the file, and (Long name) - is the descriptive string identifying the user (normally found in the - GECOS field of the UNIX password database).

    If you are getting banner pages, check and make sure that the +printcap option or printer option is configured for no banners. +If you have a printcap, this is the :sh (suppress header or banner +page) option. You should have the following in your printer.

    If the parameter nt acl support - is set to false then the file owner will - be shown as the NT user "Everyone" and the - permissions will be shown as NT "Full Control".

       printer: ... :sh

    The permissions field is displayed differently for files - and directories, so I'll describe the way file permissions - are displayed first.

    5.4.1. File Permissions

    If you have this option and are still getting banner pages, there +is a strong chance that your printer is generating them for you +automatically. You should make sure that banner printing is disabled +for the printer. This usually requires using the printer setup software +or procedures supplied by the printer manufacturer.

    The standard UNIX user/group/world triple and - the corresponding "read", "write", "execute" permissions - triples are mapped by Samba into a three element NT ACL - with the 'r', 'w', and 'x' bits mapped into the corresponding - NT permissions. The UNIX world permissions are mapped into - the global NT group Everyone, followed - by the list of permissions allowed for UNIX world. The UNIX - owner and group permissions are displayed as an NT - user icon and an NT local - group icon respectively followed by the list - of permissions allowed for the UNIX user and group.

    If you get an extra page of output, this could be due to problems +with your job format, or if you are generating PostScript jobs, +incorrect setting on your printer driver on the MicroSoft client. +For example, under Win95 there is a option:

    As many UNIX permission sets don't map into common - NT names such as "read", "change" or "full control" then - usually the permissions will be prefixed by the words "Special Access" in the NT display list.

      Printers|Printer Name|(Right Click)Properties|Postscript|Advanced|

    But what happens if the file has no permissions allowed - for a particular UNIX user group or world component ? In order - to allow "no permissions" to be seen and modified then Samba - overloads the NT "Take Ownership" ACL attribute - (which has no meaning in UNIX) and reports a component with - no permissions as having the NT "O" bit set. - This was chosen of course to make it look like a zero, meaning - zero permissions. More details on the decision behind this will - be given below.

    that allows you to choose if a Ctrl-D is appended to all jobs. +This is a very bad thing to do, as most spooling systems will +automatically add a ^D to the end of the job if it is detected as +PostScript. The multiple ^D may cause an additional page of output.

    5.4.2. Directory Permissions

    Directories on an NT NTFS file system have two - different sets of permissions. The first set of permissions - is the ACL set on the directory itself, this is usually displayed - in the first set of parentheses in the normal "RW" - NT style. This first set of permissions is created by Samba in - exactly the same way as normal file permissions are, described - above, and is displayed in the same way.

    The second set of directory permissions has no real meaning - in the UNIX permissions world and represents the "inherited" permissions that any file created within - this directory would inherit.

    8.7. Raw PostScript printed

    Samba synthesises these inherited permissions for NT by - returning as an NT ACL the UNIX permission mode that a new file - created by Samba on this share would receive.

    This is a problem that is usually caused by either the print spooling +system putting information at the start of the print job that makes +the printer think the job is a text file, or your printer simply +does not support PostScript. You may need to enable 'Automatic +Format Detection' on your printer.

    5.5. Modifying file or directory permissions8.8. Advanced Printing

    Modifying file and directory permissions is as simple - as changing the displayed permissions in the dialog box, and - clicking the OK button. However, there are - limitations that a user needs to be aware of, and also interactions - with the standard Samba permission masks and mapping of DOS - attributes that need to also be taken into account.

    If the parameter nt acl support - is set to false then any attempt to set - security permissions will fail with an "Access Denied" - message.

    The first thing to note is that the "Add" - button will not return a list of users in Samba 2.0.4 (it will give - an error message of "The remote procedure call failed - and did not execute"). This means that you can only - manipulate the current user/group/world permissions listed in - the dialog box. This actually works quite well as these are the - only permissions that UNIX actually has.

    If a permission triple (either user, group, or world) - is removed from the list of permissions in the NT dialog box, - then when the "OK" button is pressed it will - be applied as "no permissions" on the UNIX side. If you then - view the permissions again the "no permissions" entry will appear - as the NT "O" flag, as described above. This - allows you to add permissions back to a file or directory once - you have removed them from a triple component.

    As UNIX supports only the "r", "w" and "x" bits of - an NT ACL then if other NT security attributes such as "Delete - access" are selected then they will be ignored when applied on - the Samba server.

    When setting permissions on a directory the second - set of permissions (in the second set of parentheses) is - by default applied to all files within that directory. If this - is not what you want you must uncheck the "Replace - permissions on existing files" checkbox in the NT - dialog before clicking "OK".

    Note that you can do some pretty magic things by using your +imagination with the "print command" option and some shell scripts. +Doing print accounting is easy by passing the %U option to a print +command shell script. You could even make the print command detect +the type of output and its size and send it to an appropriate +printer.

    8.9. Real debugging

    If you wish to remove all permissions from a - user/group/world component then you may either highlight the - component and click the "Remove" button, - or set the component to only have the special "Take - Ownership" permission (displayed as "O" - ) highlighted.

    If the above debug tips don't help, then maybe you need to bring in +the bug guns, system tracing. See Tracing.txt in this directory.

    Chapter 9. Security levels

    5.6. Interaction with the standard Samba create mask - parameters9.1. Introduction

    Note that with Samba 2.0.5 there are four new parameters - to control this interaction. These are :

    Samba supports the following options to the global smb.conf parameter

    [global]
+security masksecurity = [share|user(default)|domain|ads]

    force security mode

    Please refer to the smb.conf man page for usage information and to the document +DOMAIN_MEMBER.html for further background details +on domain mode security. The Windows 2000 Kerberos domain security model +(security = ads) is described in the ADS-HOWTO.html.

    directory security mask

    Of the above, "security = server" means that Samba reports to clients that +it is running in "user mode" but actually passes off all authentication +requests to another "user mode" server. This requires an additional +parameter "password server =" that points to the real authentication server. +That real authentication server can be another Samba server or can be a +Windows NT server, the later natively capable of encrypted password support.

    9.2. More complete description of security levels

    A SMB server tells the client at startup what "security level" it is +running. There are two options "share level" and "user level". Which +of these two the client receives affects the way the client then tries +to authenticate itself. It does not directly affect (to any great +extent) the way the Samba server does security. I know this is +strange, but it fits in with the client/server approach of SMB. In SMB +everything is initiated and controlled by the client, and the server +can only tell the client what is available and whether an action is +allowed.

    I'll describe user level security first, as its simpler. In user level +security the client will send a "session setup" command directly after +the protocol negotiation. This contains a username and password. The +server can either accept or reject that username/password +combination. Note that at this stage the server has no idea what +share the client will eventually try to connect to, so it can't base +the "accept/reject" on anything other than:

    force directory security mode

    1. Once a user clicks "OK" to apply the - permissions Samba maps the given permissions into a user/group/world - r/w/x triple set, and then will check the changed permissions for a - file against the bits set in the - security mask parameter. Any bits that - were changed that are not set to '1' in this parameter are left alone - in the file permissions.

      the username/password

    2. Essentially, zero bits in the security mask - mask may be treated as a set of bits the user is not - allowed to change, and one bits are those the user is allowed to change. -

      the machine that the client is coming from

    If not set explicitly this parameter is set to the same value as - the create mask - parameter to provide compatibility with Samba 2.0.4 - where this permission change facility was introduced. To allow a user to - modify all the user/group/world permissions on a file, set this parameter - to 0777.

    If the server accepts the username/password then the client expects to +be able to mount any share (using a "tree connection") without +specifying a password. It expects that all access rights will be as +the username/password specified in the "session setup".

    It is also possible for a client to send multiple "session setup" +requests. When the server responds it gives the client a "uid" to use +as an authentication tag for that username/password. The client can +maintain multiple authentication contexts in this way (WinDD is an +example of an application that does this)

    Ok, now for share level security. In share level security the client +authenticates itself separately for each share. It will send a +password along with each "tree connection" (share mount). It does not +explicitly send a username with this operation. The client is +expecting a password to be associated with each share, independent of +the user. This means that samba has to work out what username the +client probably wants to use. It is never explicitly sent the +username. Some commercial SMB servers such as NT actually associate +passwords directly with shares in share level security, but samba +always uses the unix authentication scheme where it is a +username/password that is authenticated, not a "share/password".

    Many clients send a "session setup" even if the server is in share +level security. They normally send a valid username but no +password. Samba records this username in a list of "possible +usernames". When the client then does a "tree connection" it also adds +to this list the name of the share they try to connect to (useful for +home directories) and any users listed in the "user =" smb.conf +line. The password is then checked in turn against these "possible +usernames". If a match is found then the client is authenticated as +that user.

    Finally "server level" security. In server level security the samba +server reports to the client that it is in user level security. The +client then does a "session setup" as described earlier. The samba +server takes the username/password that the client sends and attempts +to login to the "password server" by sending exactly the same +username/password that it got from the client. If that server is in +user level security and accepts the password then samba accepts the +clients connection. This allows the samba server to use another SMB +server as the "password server".

    You should also note that at the very start of all this, where the +server tells the client what security level it is in, it also tells +the client if it supports encryption. If it does then it supplies the +client with a random "cryptkey". The client will then send all +passwords in encrypted form. You have to compile samba with encryption +enabled to support this feature, and you have to maintain a separate +smbpasswd file with SMB style encrypted passwords. It is +cryptographically impossible to translate from unix style encryption +to SMB style encryption, although there are some fairly simple management +schemes by which the two could be kept in sync.

    Chapter 10. security = domain in Samba 2.x

    10.1. Joining an NT Domain with Samba 2.2

    Next Samba checks the changed permissions for a file against - the bits set in the force security mode parameter. Any bits - that were changed that correspond to bits set to '1' in this parameter - are forced to be set.

    Assume you have a Samba 2.x server with a NetBIOS name of + SERV1 and are joining an NT domain called + DOM, which has a PDC with a NetBIOS name + of DOMPDC and two backup domain controllers + with NetBIOS names DOMBDC1 and DOMBDC2 + .

    Essentially, bits set in the force security mode - parameter may be treated as a set of bits that, when - modifying security on a file, the user has always set to be 'on'.

    In order to join the domain, first stop all Samba daemons + and run the command:

    If not set explicitly this parameter is set to the same value - as the force - create mode parameter to provide compatibility - with Samba 2.0.4 where the permission change facility was introduced. - To allow a user to modify all the user/group/world permissions on a file - with no restrictions set this parameter to 000.

    The security mask and force - security mode parameters are applied to the change - request in that order.

    For a directory Samba will perform the same operations as - described above for a file except using the parameter directory security mask instead of security - mask, and root# smbpasswd -j DOM -r DOMPDC + -Uforce directory security mode - Administrator%password parameter instead of force security mode - .

    The directory security mask parameter - by default is set to the same value as the directory mask - parameter and the force directory security - mode parameter by default is set to the same value as - the as we are joining the domain DOM and the PDC for that domain + (the only machine that has write access to the domain SAM database) + is DOMPDC. The force directory modeAdministrator%password parameter to provide - compatibility with Samba 2.0.4 where the permission change facility - was introduced.

    is + the login name and password for an account which has the necessary + privilege to add machines to the domain. If this is successful + you will see the message:

    In this way Samba enforces the permission restrictions that - an administrator can set on a Samba share, whilst still allowing users - to modify the permission bits within that restriction.

    smbpasswd: Joined domain DOM. +

    If you want to set up a share that allows users full control - in modifying the permission bits on their files and directories and - doesn't force any particular bits to be set 'on', then set the following - parameters in the in your terminal window. See the smb.conf(5) - file in that share specific section :

    smbpasswd(8) man page for more details.

    There is existing development code to join a domain + without having to create the machine trust account on the PDC + beforehand. This code will hopefully be available soon + in release branches as well.

    This command goes through the machine account password + change protocol, then writes the new (random) machine account + password for this Samba server into a file in the same directory + in which an smbpasswd file would be stored - normally :

    security mask = 0777/usr/local/samba/private

    In Samba 2.0.x, the filename looks like this:

    force security mode = 0<NT DOMAIN NAME>

    .directory security mask = 0777<Samba + Server Name>.mac

    The .mac suffix stands for machine account + password file. So in our example above, the file would be called:

    force directory security mode = 0DOM.SERV1.mac

    As described, in Samba 2.0.4 the parameters :

    In Samba 2.2, this file has been replaced with a TDB + (Trivial Database) file named secrets.tdb. +

    This file is created and owned by root and is not + readable by any other user. It is the key to the domain-level + security for your system, and should be treated as carefully + as a shadow password file.

    Now, before restarting the Samba daemons you must + edit your smb.conf(5) + file to tell Samba it should now use domain security.

    Change (or add) your create masksecurity = line in the [global] section + of your smb.conf to read:

    security = domain

    Next change the force create mode workgroup = line in the [global] section to read:

    workgroup = DOM

    as this is the name of the domain we are joining.

    You must also have the parameter directory maskencrypt passwords

    set to yes + in order for your users to authenticate to the NT PDC.

    Finally, add (or modify) a force directory modepassword server = line in the [global] + section to read:

    password server = DOMPDC DOMBDC1 DOMBDC2

    were used instead of the parameters discussed here.

    These are the primary and backup domain controllers Samba + will attempt to contact in order to authenticate users. Samba will + try to contact each of these servers in order, so you may want to + rearrange this list in order to spread out the authentication load + among domain controllers.

    Alternatively, if you want smbd to automatically determine + the list of Domain controllers to use for authentication, you may + set this line to be :

    password server = *

    This method, which was introduced in Samba 2.0.6, + allows Samba to use exactly the same mechanism that NT does. This + method either broadcasts or uses a WINS database in order to + find domain controllers to authenticate against.

    Finally, restart your Samba daemons and get ready for + clients to begin using domain security!

    5.7. Interaction with the standard Samba file attribute - mapping10.2. Samba and Windows 2000 Domains

    Samba maps some of the DOS attribute bits (such as "read - only") into the UNIX permissions of a file. This means there can - be a conflict between the permission bits set via the security - dialog and the permission bits set by the file attribute mapping. +>Many people have asked regarding the state of Samba's ability to participate in +a Windows 2000 Domain. Samba 2.2 is able to act as a member server of a Windows +2000 domain operating in mixed or native mode.

    There is much confusion between the circumstances that require a "mixed" mode +Win2k DC and a when this host can be switched to "native" mode. A "mixed" mode +Win2k domain controller is only needed if Windows NT BDCs must exist in the same +domain. By default, a Win2k DC in "native" mode will still support +NetBIOS and NTLMv1 for authentication of legacy clients such as Windows 9x and +NT 4.0. Samba has the same requirements as a Windows NT 4.0 member server.

    The steps for adding a Samba 2.2 host to a Win2k domain are the same as those +for adding a Samba server to a Windows NT 4.0 domain. The only exception is that +the "Server Manager" from NT 4 has been replaced by the "Active Directory Users and +Computers" MMC (Microsoft Management Console) plugin.

    10.3. Why is this better than security = server?

    Currently, domain security in Samba doesn't free you from + having to create local Unix users to represent the users attaching + to your server. This means that if domain user DOM\fred + attaches to your domain security Samba server, there needs + to be a local Unix user fred to represent that user in the Unix + filesystem. This is very similar to the older Samba security mode + security = server, + where Samba would pass through the authentication request to a Windows + NT server in the same way as a Windows 95 or Windows 98 server would.

    One way this can show up is if a file has no UNIX read access - for the owner it will show up as "read only" in the standard - file attributes tabbed dialog. Unfortunately this dialog is - the same one that contains the security info in another tab.

    Please refer to the Winbind + paper for information on a system to automatically + assign UNIX uids and gids to Windows NT Domain users and groups. + This code is available in development branches only at the moment, + but will be moved to release branches soon.

    What this can mean is that if the owner changes the permissions - to allow themselves read access using the security dialog, clicks - "OK" to get back to the standard attributes tab - dialog, and then clicks "OK" on that dialog, then - NT will set the file permissions back to read-only (as that is what - the attributes still say in the dialog). This means that after setting - permissions and clicking "OK" to get back to the - attributes dialog you should always hit The advantage to domain-level security is that the + authentication in domain-level security is passed down the authenticated + RPC channel in exactly the same way that an NT server would do it. This + means Samba servers now participate in domain trust relationships in + exactly the same way NT servers do (i.e., you can add Samba servers into + a resource domain and have the authentication passed on from a resource + domain PDC to an account domain PDC.

    In addition, with "Cancel" - rather than security = server every Samba + daemon on a server has to keep a connection open to the + authenticating server for as long as that daemon lasts. This can drain + the connection resources on a Microsoft NT server and cause it to run + out of available connections. With "OK" to ensure that your changes - are not overridden.

    security = domain, + however, the Samba daemons connect to the PDC/BDC only for as long + as is necessary to authenticate the user, and then drop the connection, + thus conserving PDC connection resources.

    And finally, acting in the same manner as an NT server + authenticating to a PDC means that as part of the authentication + reply, the Samba server gets the user identification information such + as the user SID, the list of NT groups the user belongs to, etc. All + this information will allow Samba to be extended in the future into + a mode the developers currently call appliance mode. In this mode, + no local Unix users will be necessary, and Samba will generate Unix + uids and gids from the information passed back from the PDC when a + user is authenticated, making a Samba server truly plug and play + in an NT domain environment. Watch for this code soon.

    NOTE: Much of the text of this document + was first published in the Web magazine + LinuxWorld as the article Doing + the NIS/NT Samba.

    Chapter 6. Printing Support in Samba 2.2.xChapter 11. Unified Logons between Windows NT and UNIX using Winbind

    6.1. Introduction11.1. Abstract

    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.

    Integration of UNIX and Microsoft Windows NT through + a unified logon has been considered a "holy grail" in heterogeneous + computing environments for a long time. We present + winbind, a component of the Samba suite + of programs as a solution to the unified logon problem. Winbind + uses a UNIX implementation + of Microsoft RPC calls, Pluggable Authentication Modules, and the Name + Service Switch to allow Windows NT domain users to appear and operate + as UNIX users on a UNIX machine. This paper describes the winbind + system, explaining the functionality it provides, how it is configured, + and how it works internally.

    11.2. Introduction

    The additional functionality provided by the new -SPOOLSS support includes:

    It is well known that UNIX and Microsoft Windows NT have + different models for representing user and group information and + use different technologies for implementing them. This fact has + made it difficult to integrate the two systems in a satisfactory + manner.

    One common solution in use today has been to create + identically named user accounts on both the UNIX and Windows systems + and use the Samba suite of programs to provide file and print services + between the two. This solution is far from perfect however, as + adding and deleting users on both sets of machines becomes a chore + and two sets of passwords are required both of which + can lead to synchronization problems between the UNIX and Windows + systems and confusion for users.

    We divide the unified logon problem for UNIX machines into + three smaller problems:

    • Support for downloading printer driver - files to Windows 95/98/NT/2000 clients upon demand. -

      Obtaining Windows NT user and group information +

    • Uploading of printer drivers via the - Windows NT Add Printer Wizard (APW) or the - Imprints tool set (refer to http://imprints.sourceforge.net). -

      Authenticating Windows NT users +

    • Support for the native MS-RPC printing - calls such as StartDocPrinter, EnumJobs(), etc... (See - the MSDN documentation at http://msdn.microsoft.com/ - for more information on the Win32 printing API) -

      Password changing for Windows NT users +

    Support for NT Access Control Lists (ACL) - on printer objects

  • Ideally, a prospective solution to the unified logon problem + would satisfy all the above components without duplication of + information on the UNIX machines and without creating additional + tasks for the system administrator when maintaining users and + groups on either system. The winbind system provides a simple + and elegant solution to all three components of the unified logon + problem.

    • 11.3. What Winbind Provides

    Improved support for printer queue manipulation - through the use of an internal databases for spooled job - information

    Winbind unifies UNIX and Windows NT account management by + allowing a UNIX box to become a full member of a NT domain. Once + this is done the UNIX box will see NT users and groups as if + they were native UNIX users and groups, allowing the NT domain + to be used in much the same manner that NIS+ is used within + UNIX-only environments.

    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.

    The end result is that whenever any + program on the UNIX machine asks the operating system to lookup + a user or group name, the query will be resolved by asking the + NT domain controller for the specified domain to do the lookup. + Because Winbind hooks into the operating system at a low level + (via the NSS name resolution modules in the C library) this + redirection to the NT domain controller is completely + transparent.

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

    Users on the UNIX machine can then use NT user and group + names as they would use "native" UNIX names. They can chown files + so that they are owned by NT domain users or even login to the + UNIX machine and run a UNIX X-Window session as a domain user.

    The only obvious indication that Winbind is being used is + that user and group names take the form DOMAIN\user and + DOMAIN\group. This is necessary as it allows Winbind to determine + that redirection to a domain controller is wanted for a particular + lookup and which trusted domain is being referenced.

    Additionally, Winbind provides an authentication service + that hooks into the Pluggable Authentication Modules (PAM) system + to provide authentication via a NT domain to any PAM enabled + applications. This capability solves the problem of synchronizing + passwords between systems since all passwords are stored in a single + location (on the domain controller).

    11.3.1. Target Uses

    Winbind is targeted at organizations that have an + existing NT based domain infrastructure into which they wish + to put UNIX workstations or servers. Winbind will allow these + organizations to deploy UNIX workstations without having to + maintain a separate account infrastructure. This greatly + simplifies the administrative overhead of deploying UNIX + workstations into a NT based organization.

    Another interesting way in which we expect Winbind to + be used is as a central part of UNIX based appliances. Appliances + that provide file and print services to Microsoft based networks + will be able to use Winbind to provide seamless integration of + the appliance into the domain.

    http://support.microsoft.com/support/kb/articles/Q189/1/05.ASP

    11.4. How Winbind Works

    The winbind system is designed around a client/server + architecture. A long running winbindd daemon + listens on a UNIX domain socket waiting for requests + to arrive. These requests are generated by the NSS and PAM + clients and processed sequentially.

    The technologies used to implement winbind are described + in detail below.

    11.4.1. Microsoft Remote Procedure Calls

    Over the last two years, efforts have been underway + by various Samba Team members to decode various aspects of + the Microsoft Remote Procedure Call (MSRPC) system. This + system is used for most network related operations between + Windows NT machines including remote management, user authentication + and print spooling. Although initially this work was done + to aid the implementation of Primary Domain Controller (PDC) + functionality in Samba, it has also yielded a body of code which + can be used for other purposes.

    Winbind uses various MSRPC calls to enumerate domain users + and groups and to obtain detailed information about individual + users or groups. Other MSRPC calls can be used to authenticate + NT domain users and to change user passwords. By directly querying + a Windows PDC for user and group information, winbind maps the + NT account information onto UNIX user and group names.

    6.2. Configuration

    11.4.2. Name Service Switch

    [print$] vs. [printer$]
    The Name Service Switch, or NSS, is a feature that is + present in many UNIX operating systems. It allows system + information such as hostnames, mail aliases and user information + to be resolved from different sources. For example, a standalone + UNIX workstation may resolve system information from a series of + flat files stored on the local filesystem. A networked workstation + may first attempt to resolve system information from local files, + and then consult a NIS database for user information or a DNS server + for hostname information.

    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.

    The NSS application programming interface allows winbind + to present itself as a source of system information when + resolving UNIX usernames and groups. Winbind uses this interface, + and information obtained from a Windows NT server using MSRPC + calls to provide a new source of account enumeration. Using standard + UNIX library calls, one can enumerate the users and groups on + a UNIX machine running winbind and see all users and groups in + a NT domain plus any trusted domain as though they were local + users and groups.

    However, the initial implementation allowed for a -parameter named printer driver locationThe primary control file for NSS is + /etc/nsswitch.conf. + When a UNIX application makes a request to do a lookup + the C library looks in /etc/nsswitch.conf -to be used on a per share basis to specify the location of -the driver files associated with that printer. Another -parameter named printer driver provided -a means of defining the printer driver name to be sent to -the client.

    These parameters, including printer driver -file parameter, are being depreciated and should not -be used in new installations. For more information on this change, -you should refer to the Migration section -of this document.

    passwd: files example

    then the C library will first load a module called + /lib/libnss_files.so followed by + the module /lib/libnss_example.so. The + C library will dynamically load each of these modules in turn + and call resolver functions within the modules to try to resolve + the request. Once the request is resolved the C library returns the + result to the application.

    This NSS interface provides a very easy way for Winbind + to hook into the operating system. All that needs to be done + is to put libnss_winbind.so in /lib/ + then add "winbind" into /etc/nsswitch.conf at + the appropriate place. The C library will then call Winbind to + resolve user and group names.

    6.2.1. Creating [print$]11.4.3. Pluggable Authentication Modules

    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).

    You should modify the server's smb.conf file to add the global -parameters and 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):

    Pluggable Authentication Modules, also known as PAM, + is a system for abstracting authentication and authorization + technologies. With a PAM module it is possible to specify different + authentication methods for different system applications without + having to recompile these applications. PAM is also useful + for implementing a particular policy for authorization. For example, + a system administrator may only allow console logins from users + stored in the local password file but only allow users resolved from + a NIS database to log in over the network.

    [global]
-    ; members of the ntadmin group should be able
-    ; to add drivers and set printer properties
-    ; root is implicitly a 'printer admin'
-    printer admin = @ntadmin
-
-[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,root

    Winbind uses the authentication management and password + management PAM interface to integrate Windows NT users into a + UNIX system. This allows Windows NT users to log in to a UNIX + machine and be authenticated against a suitable Primary Domain + Controller. These users can also change their passwords and have + this change take effect directly on the Primary Domain Controller. +

    The write list is used to allow administrative -level user accounts to have write access in order to update files -on the share. See the smb.conf(5) -man page for more information on configuring file shares.

    PAM is configured by providing control files in the directory + /etc/pam.d/ for each of the services that + require authentication. When an authentication request is made + by an application the PAM code in the C library looks up this + control file to determine what modules to load to do the + authentication check and in what order. This interface makes adding + a new authentication service for Winbind very easy, all that needs + to be done is that the pam_winbind.so module + is copied to /lib/security/ and the PAM + control files for relevant services are updated to allow + authentication via winbind. See the PAM documentation + for more details.

    11.4.4. User and Group ID Allocation

    The requirement for guest -ok = yes 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.

    When a user or group is created under Windows NT + is it allocated a numerical relative identifier (RID). This is + slightly different to UNIX which has a range of numbers that are + used to identify users, and the same range in which to identify + groups. It is winbind's job to convert RIDs to UNIX id numbers and + vice versa. When winbind is configured it is given part of the UNIX + user id space and a part of the UNIX group id space in which to + store Windows NT users and groups. If a Windows NT user is + resolved for the first time, it is allocated the next UNIX id from + the range. The same process applies for Windows NT groups. Over + time, winbind will have mapped all Windows NT users and groups + to UNIX user ids and group ids.

    The results of this mapping are stored persistently in + an ID mapping database held in a tdb database). This ensures that + RIDs are mapped to UNIX IDs in a consistent way.

    11.4.5. Result Caching

    Author's Note: 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 map to guest = Bad User in the [global] section as well. Make sure -you understand what this parameter does before using it -though. --jerry

    An active system can generate a lot of user and group + name lookups. To reduce the network cost of these lookups winbind + uses a caching scheme based on the SAM sequence number supplied + by NT domain controllers. User or group information returned + by a PDC is cached by winbind along with a sequence number also + returned by the PDC. This sequence number is incremented by + Windows NT whenever any user or group information is modified. If + a cached entry has expired, the sequence number is requested from + the PDC and compared against the sequence number of the cached entry. + If the sequence numbers do not match, then the cached information + is discarded and up to date information is requested directly + from the PDC.

    11.5. Installation and Configuration

    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.

    Many thanks to John Trostel jtrostel@snapserver.com +for providing the HOWTO for this section.

    Next create the directory tree below the [print$] share -for each architecture you wish to support.

    This HOWTO describes how to get winbind services up and running +to control access and authenticate users on your Linux box using +the winbind services which come with SAMBA 2.2.2.

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

    There is also some Solaris specific information in +docs/textdocs/Solaris-Winbind-HOWTO.txt. +Future revisions of this document will incorporate that +information.

    11.5.1. Introduction

    ATTENTION! REQUIRED PERMISSIONS
    This HOWTO describes the procedures used to get winbind up and +running on my RedHat 7.1 system. Winbind is capable of providing access +and authentication control for Windows Domain users through an NT +or Win2K PDC for 'regular' services, such as telnet a nd ftp, as +well for SAMBA services.

    In order to currently add a new driver to you Samba host, -one of two conditions must hold true:

    This HOWTO has been written from a 'RedHat-centric' perspective, so if +you are using another distribution, you may have to modify the instructions +somewhat to fit the way your distribution works.

    • The account used to connect to the Samba host - must have a uid of 0 (i.e. a root account)

      Why should I to this? +

      This allows the SAMBA administrator to rely on the + authentication mechanisms on the NT/Win2K PDC for the authentication + of domain members. NT/Win2K users no longer need to have separate + accounts on the SAMBA server. +

    • The account used to connect to the Samba host - must be a member of the printer - admin list.

      Who should be reading this document? +

      This HOWTO is designed for system administrators. If you are + implementing SAMBA on a file server and wish to (fairly easily) + integrate existing NT/Win2K users from your PDC onto the + SAMBA server, this HOWTO is for you. That said, I am no NT or PAM + expert, so you may find a better or easier way to accomplish + these tasks. +

    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.

    Once you have created the required [print$] service and -associated subdirectories, simply log onto the Samba server using -a root (or printer admin) account -from a Windows NT 4.0/2k client. Open "Network Neighbourhood" or -"My Network Places" and browse for the Samba host. Once you have located -the server, navigate to the "Printers..." folder. -You should see an initial listing of printers -that matches the printer shares defined on your Samba host.

    6.2.2. Setting Drivers for Existing Printers11.5.2. Requirements

    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 +>If you have a samba configuration file that you are currently +using... BACK IT UP! If your system already uses PAM, NO PRINTER DRIVER AVAILABLE FOR THIS PRINTER. -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:

    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?

    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

    back up the /etc/pam.d directory +contents! If you haven't already made a boot disk, +MAKE ONE NOW!

    • Use the "New Driver..." button to install - a new printer driver, or

    • Select a driver from the popup list of - installed drivers. Initially this list will be empty.

    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.

    Messing with the pam configuration files can make it nearly impossible +to log in to yourmachine. That's why you want to be able to boot back +into your machine in single user mode and restore your +/etc/pam.d back to the original state they were in if +you get frustrated with the way things are going. ;-)

    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.

    The latest version of SAMBA (version 2.2.2 as of this writing), now +includes a functioning winbindd daemon. Please refer to the +main SAMBA web page or, +better yet, your closest SAMBA mirror site for instructions on +downloading the source code.

    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 -To allow Domain users the ability to access SAMBA shares and +files, as well as potentially other services provided by your +SAMBA machine, PAM (pluggable authentication modules) must +be setup properly on your machine. In order to compile the +winbind modules, you should have at least the pam libraries resident +on your system. For recent RedHat systems (7.1, for instance), that +means smb.confpam-0.74-22. For best results, it is helpful to also +install the development packages in pam-devel-0.74-22.

    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.

    6.2.3. Support a large number of printers11.5.3. Testing Things Out

    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 Before starting, it is probably best to kill off all the SAMBA +related daemons running on your server. Kill off all rpcclient's -setdriver command can be used to set the driver -associated with an installed driver. The following is example -of how this could be accomplished:

    smbd, +nmbd, and winbindd processes that may +be running. To use PAM, you will want to make sure that you have the +standard PAM package (for RedHat) which supplies the /etc/pam.d +directory structure, including the pam modules are used by pam-aware +services, several pam libraries, and the /usr/doc +and /usr/man entries for pam. Winbind built better +in SAMBA if the pam-devel package was also installed. This package includes +the header files needed to compile pam-aware applications. For instance, +my RedHat system has both pam-0.74-22 and +pam-devel-0.74-22 RPMs installed.

    11.5.3.1. Configure and compile SAMBA

    The configuration and compilation of SAMBA is pretty straightforward. +The first three steps may not be necessary depending upon +whether or not you have previously built the Samba binaries.

     
+>root# autoconf
 $ 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]
-				  
+>root# make clean
 $ 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:[]
-				  
+>root# rm config.cache
 $ rpcclient pogo -U root%secret \
+>root# ./configure --with-winbind
 >  -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.
    root# make +root# make install

    This will, by default, install SAMBA in /usr/local/samba. +See the main SAMBA documentation if you want to install SAMBA somewhere else. +It will also build the winbindd executable and libraries.

    6.2.4. Adding New Printers via the Windows NT APW

    By default, Samba offers all printer shares defined in 11.5.3.2. Configure smb.conf -in the "Printers..." folder. Also existing in this folder is the Windows NT -Add Printer Wizard icon. The APW will be show only if

    nsswitch.conf and the +winbind libraries

    The libraries needed to run the winbindd daemon +through nsswitch need to be copied to their proper locations, so

    root# cp ../samba/source/nsswitch/libnss_winbind.so /lib

    • The connected user is able to successfully - execute an OpenPrinterEx(\\server) with administrative - privileges (i.e. root or printer admin). -

    • I also found it necessary to make the following symbolic link:

      show - add printer wizard = yes (the default). -

    root#     ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2

    And, in the case of Sun solaris:

    In order to be able to use the APW to successfully add a printer to a Samba -server, the add -printer command must have a defined value. The program -hook must successfully add the printer to the system (i.e. +CLASS="PROMPT" +>root# ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1 /etc/printcap or appropriate files) and +CLASS="PROMPT" +>root# ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1 smb.conf if necessary.

    root# ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2

    When using the APW from a client, if the named printer share does -not exist, Now, as root you need to edit /etc/nsswitch.conf to +allow user and group entries to be visible from the smbd will execute the add printer -command and reparse to the winbindd +daemon. My smb.conf -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 -add printer program is executed under the context -of the connected user, not necessarily a root account.

    /etc/nsswitch.conf file look like +this after editing:

    	passwd:     files winbind
+	shadow:     files 
+	group:      files winbind

    +The libraries needed by the winbind daemon will be automatically +entered into the ldconfig cache the next time +your system reboots, but it +is faster (and you don't need to reboot) if you do it manually:

    There is a complementing delete -printer command for removing entries from the "Printers..." -folder.

    root# /sbin/ldconfig -v | grep winbind

    This makes libnss_winbind available to winbindd +and echos back a check to you.

    6.2.5. Samba and Printer Ports

    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.

    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.

    11.5.3.3. Configure smb.conf

    If you require that multiple ports be defined for some reason, +>Several parameters are needed in the smb.conf file to control +the behavior of winbindd. Configure smb.conf possesses a These are described in more detail in +the enumports -command which can be used to define an external program -that generates a listing of ports on a system.

    6.3. The Imprints Toolset

    winbindd(8) man page. My +smb.conf file was modified to +include the following entries in the [global] section:

    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 
    [global]
+     <...>
+     # separate domain and username with '+', like DOMAIN+username
+     	http://imprints.sourceforge.net/ as well as the documentation 
-	included with the imprints source distribution.  This section will 
-	only provide a brief introduction to the features of Imprints.
    6.3.1. What is Imprints?
    Imprints is a collection of tools for supporting the goals 
-		of
    winbind separator = +
+     # use uids from 10000 to 20000 for domain users
+     winbind uid = 10000-20000
+     # use gids from 10000 to 20000 for domain groups
+     winbind gid = 10000-20000
+     # allow enumeration of winbind users and groups
+     winbind enum users = yes
+     winbind enum groups = yes
+     # give winbind users a real shell (only needed if they have telnet access)
+     template homedir = /home/winnt/%D/%U
+     template shell = /bin/bash

    6.3.2. Creating Printer Driver Packages

    11.5.3.4. Join the SAMBA server to the PDC domain

    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.

    6.3.3. The Imprints server

    Enter the following command to make the SAMBA server join the +PDC domain, where DOMAIN is the name of +your Windows domain and Administrator is +a domain user who has administrative privileges in the domain.

    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 - not recommended that this security check - be disabled.

    root# /usr/local/samba/bin/net rpc join -s PDC -U Administrator

    The proper response to the command should be: "Joined the domain +DOMAIN" where DOMAIN +is your DOMAIN name.

    6.3.4. The Installation Client

    11.5.3.5. Start up the winbindd daemon and test it!

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

    Eventually, you will want to modify your smb startup script to +automatically invoke the winbindd daemon when the other parts of +SAMBA start, but it is possible to test out just the winbind +portion first. To start up winbind services, enter the following +command as root:

    The Imprints installation client comes in two forms.

    root# /usr/local/samba/bin/winbindd

    I'm always paranoid and like to make sure the daemon +is really running...

    root# ps -ae | grep winbindd

    • a set of command line Perl scripts

    • This command should produce output like this, if the daemon is running

      a GTK+ based graphical interface to - the command line perl scripts

    3025 ? 00:00:00 winbindd

    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.

    Now... for the real test, try to get some information about the +users on your PDC

    The basic installation process is in four steps and - perl code is wrapped around smbclient - and root# rpcclient.

    /usr/local/samba/bin/wbinfo -u

    +This should echo back a list of users on your Windows users on +your PDC. For example, I get the following response:

    	
-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
    CEO+Administrator +CEO+burdell +CEO+Guest +CEO+jt-ad +CEO+krbtgt +CEO+TsInternetUser

    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 calls its version of this driver "Apple - LaserWriter II NTX"

    Obviously, I have named my domain 'CEO' and my winbind +separator is '+'.

    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

    You can do the same sort of thing to get group information from +the PDC:

    HKLM\System\CurrentControlSet\Control\Print\Environment
-		root# /usr/local/samba/bin/wbinfo -g
+CEO+Domain Admins
+CEO+Domain Users
+CEO+Domain Guests
+CEO+Domain Computers
+CEO+Domain Controllers
+CEO+Cert Publishers
+CEO+Schema Admins
+CEO+Enterprise Admins
+CEO+Group Policy Creator Owners

    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?

    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.

    6.4. Migration to from Samba 2.0.x to 2.2.x

    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. Here are the possible scenarios for -migration:

    The function 'getent' can now be used to get unified +lists of both local and PDC users and groups. +Try the following command:

    root# getent passwd

    • If you do not desire the new Windows NT - print driver support, nothing needs to be done. - All existing parameters work the same.

    • 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 - You should get a list that looks like your 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 make_printerdef/etc/passwd - tool will also remain for backwards compatibility but will - be removed in the next major release.

    • 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).

    • The same thing can be done for groups with the command

      root# getent group

    11.5.3.6. Fix the init.d startup scripts

    11.5.3.6.1. Linux

    If you want to migrate an existing printers.def - 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 The smbclientwinbindd daemon needs to start up after the +smbd and rpcclient. See the - Imprints installation client at http://imprints.sourceforge.net/ - for an example. -

    nmbd daemons are running. +To accomplish this task, you need to modify the startup scripts of your system. They are located at /etc/init.d/smb in RedHat and +/etc/init.d/samba in Debian. +script to add commands to invoke this daemon in the proper sequence. My +startup script starts up smbd, +nmbd, and winbindd from the +/usr/local/samba/bin directory directly. The 'start' +function in the script looks like this:

    Achtung!
    start() {
+        KIND="SMB"
+        echo -n $"Starting $KIND services: "
+        daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
+        RETVAL=$?
+        echo
+        KIND="NMB"
+        echo -n $"Starting $KIND services: "
+        daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
+        RETVAL2=$?
+        echo
+        KIND="Winbind"
+        echo -n $"Starting $KIND services: "
+        daemon /usr/local/samba/bin/winbindd
+        RETVAL3=$?
+        echo
+        [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && touch /var/lock/subsys/smb || \
+           RETVAL=1
+        return $RETVAL
+}

    The following smb.conf parameters are considered to -be deprecated and will be removed soon. Do not use them in new -installations

    • printer driver file (G) -

    • printer driver (S) -

    • The 'stop' function has a corresponding entry to shut down the +services and look s like this:

      printer driver location (S) - 

    stop() {
+        KIND="SMB"
+        echo -n $"Shutting down $KIND services: "
+        killproc smbd
+        RETVAL=$?
+        echo
+        KIND="NMB"
+        echo -n $"Shutting down $KIND services: "
+        killproc nmbd
+        RETVAL2=$?
+        echo
+        KIND="Winbind"
+        echo -n $"Shutting down $KIND services: "
+        killproc winbindd
+        RETVAL3=$?
+        [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && rm -f /var/lock/subsys/smb
+        echo ""
+        return $RETVAL
+}

    The have been two new parameters add in Samba 2.2.2 to for -better support of Samba 2.0.x backwards capability (disable -spoolss) and for using local printers drivers on Windows -NT/2000 clients (use client driver). Both of -these options are described in the smb.coinf(5) man page and are -disabled by default.

    Chapter 7. security = domain in Samba 2.x

    7.1. Joining an NT Domain with Samba 2.2

    Assume you have a Samba 2.x server with a NetBIOS name of - SERV1 and are joining an NT domain called - DOM, which has a PDC with a NetBIOS name - of DOMPDC and two backup domain controllers - with NetBIOS names DOMBDC1 and DOMBDC2 - .

    In order to join the domain, first stop all Samba daemons - and run the command:

    root# smbpasswd -j DOM -r DOMPDC - -UAdministrator%password

    11.5.3.6.2. Solaris

    as we are joining the domain DOM and the PDC for that domain - (the only machine that has write access to the domain SAM database) - is DOMPDC. The Administrator%password is - the login name and password for an account which has the necessary - privilege to add machines to the domain. If this is successful - you will see the message:

    On solaris, you need to modify the +/etc/init.d/samba.server startup script. It usually +only starts smbd and nmbd but should now start winbindd too. If you +have samba installed in /usr/local/samba/bin, +the file could contains something like this:

    smbpasswd: Joined domain DOM. - 

    ##
+## samba.server
+##
+
+if [ ! -d /usr/bin ]
+then                    # /usr not mounted
+        exit
+fi
+
+killproc() {            # kill the named process(es)
+        pid=`/usr/bin/ps -e |
+             /usr/bin/grep -w $1 |
+             /usr/bin/sed -e 's/^  *//' -e 's/ .*//'`
+        [ "$pid" != "" ] && kill $pid
+}
+ 
+# Start/stop processes required for samba server
+
+case "$1" in
+
+'start')
+#
+# Edit these lines to suit your installation (paths, workgroup, host)
+#
+echo Starting SMBD
+   /usr/local/samba/bin/smbd -D -s \
+	/usr/local/samba/smb.conf
+
+echo Starting NMBD
+   /usr/local/samba/bin/nmbd -D -l \
+	/usr/local/samba/var/log -s /usr/local/samba/smb.conf
+
+echo Starting Winbind Daemon
+   /usr/local/samba/bin/winbindd
+   ;;
+
+'stop')
+   killproc nmbd
+   killproc smbd
+   killproc winbindd
+   ;;
+
+*)
+   echo "Usage: /etc/init.d/samba.server { start | stop }"
+   ;;
+esac

    11.5.3.6.3. Restarting

    in your terminal window. See the smbpasswd(8) man page for more details.

    If you restart the smbd, nmbd, +and winbindd daemons at this point, you +should be able to connect to the samba server as a domain member just as +if you were a local user.

    11.5.3.7. Configure Winbind and PAM

    There is existing development code to join a domain - without having to create the machine trust account on the PDC - beforehand. This code will hopefully be available soon - in release branches as well.

    If you have made it this far, you know that winbindd and samba are working +together. If you want to use winbind to provide authentication for other +services, keep reading. The pam configuration files need to be altered in +this step. (Did you remember to make backups of your original +/etc/pam.d files? If not, do it now.)

    This command goes through the machine account password - change protocol, then writes the new (random) machine account - password for this Samba server into a file in the same directory - in which an smbpasswd file would be stored - normally :

    You will need a pam module to use winbindd with these other services. This +module will be compiled in the ../source/nsswitch directory +by invoking the command

    /usr/local/samba/privateroot# make nsswitch/pam_winbind.so

    In Samba 2.0.x, the filename looks like this:

    from the ../source directory. The +pam_winbind.so file should be copied to the location of +your other pam security modules. On my RedHat system, this was the +/lib/security directory. On Solaris, the pam security +modules reside in /usr/lib/security.

    <NT DOMAIN NAME>.<Samba - Server Name>.macroot# cp ../samba/source/nsswitch/pam_winbind.so /lib/security

    11.5.3.7.1. Linux/FreeBSD-specific PAM configuration

    The .mac suffix stands for machine account - password file. So in our example above, the file would be called:

    /etc/pam.d/samba file does not need to be changed. I +just left this fileas it was:

    DOM.SERV1.mac
    auth    required        /lib/security/pam_stack.so service=system-auth
+account required        /lib/security/pam_stack.so service=system-auth

    In Samba 2.2, this file has been replaced with a TDB - (Trivial Database) file named The other services that I modified to allow the use of winbind +as an authentication service were the normal login on the console (or a terminal +session), telnet logins, and ftp service. In order to enable these +services, you may first need to change the entries in +secrets.tdb. -

    /etc/xinetd.d (or /etc/inetd.conf). +RedHat 7.1 uses the new xinetd.d structure, in this case you need +to change the lines in /etc/xinetd.d/telnet +and /etc/xinetd.d/wu-ftp from

    This file is created and owned by root and is not - readable by any other user. It is the key to the domain-level - security for your system, and should be treated as carefully - as a shadow password file.

    enable = no

    Now, before restarting the Samba daemons you must - edit your smb.conf(5) - file to tell Samba it should now use domain security.

    to

    Change (or add) your security = line in the [global] section - of your smb.conf to read:

    enable = yes

    +For ftp services to work properly, you will also need to either +have individual directories for the domain users already present on +the server, or change the home directory template to a general +directory for all domain users. These can be easily set using +the smb.conf global entry +security = domain

    template homedir.

    Next change the workgroup = line in the [global] section to read:

    The /etc/pam.d/ftp file can be changed +to allow winbind ftp access in a manner similar to the +samba file. My /etc/pam.d/ftp file was +changed to look like this:

    workgroup = DOM
    auth       required     /lib/security/pam_listfile.so item=user sense=deny file=/etc/ftpusers onerr=succeed
+auth       sufficient   /lib/security/pam_winbind.so
+auth       required     /lib/security/pam_stack.so service=system-auth
+auth       required     /lib/security/pam_shells.so
+account    sufficient   /lib/security/pam_winbind.so
+account    required     /lib/security/pam_stack.so service=system-auth
+session    required     /lib/security/pam_stack.so service=system-auth

    as this is the name of the domain we are joining.

    You must also have the parameter encrypt passwords set to yes - in order for your users to authenticate to the NT PDC.

    Finally, add (or modify) a password server = line in the [global] - section to read:

    The /etc/pam.d/login file can be changed nearly the +same way. It now looks like this:

    password server = DOMPDC DOMBDC1 DOMBDC2
    auth       required     /lib/security/pam_securetty.so
+auth       sufficient   /lib/security/pam_winbind.so
+auth       sufficient   /lib/security/pam_unix.so use_first_pass
+auth       required     /lib/security/pam_stack.so service=system-auth
+auth       required     /lib/security/pam_nologin.so
+account    sufficient   /lib/security/pam_winbind.so
+account    required     /lib/security/pam_stack.so service=system-auth
+password   required     /lib/security/pam_stack.so service=system-auth
+session    required     /lib/security/pam_stack.so service=system-auth
+session    optional     /lib/security/pam_console.so

    These are the primary and backup domain controllers Samba - will attempt to contact in order to authenticate users. Samba will - try to contact each of these servers in order, so you may want to - rearrange this list in order to spread out the authentication load - among domain controllers.

    In this case, I added the auth sufficient /lib/security/pam_winbind.so +lines as before, but also added the required pam_securetty.so +above it, to disallow root logins over the network. I also added a +sufficient /lib/security/pam_unix.so use_first_pass +line after the winbind.so line to get rid of annoying +double prompts for passwords.

    11.5.3.7.2. Solaris-specific configuration

    Alternatively, if you want smbd to automatically determine - the list of Domain controllers to use for authentication, you may - set this line to be :

    The /etc/pam.conf needs to be changed. I changed this file so that my Domain +users can logon both locally as well as telnet.The following are the changes +that I made.You can customize the pam.conf file as per your requirements,but +be sure of those changes because in the worst case it will leave your system +nearly impossible to boot.

    password server = *
    #
+#ident	"@(#)pam.conf	1.14	99/09/16 SMI"
+#
+# Copyright (c) 1996-1999, Sun Microsystems, Inc.
+# All Rights Reserved.
+#
+# PAM configuration
+#
+# Authentication management
+#
+login   auth required   /usr/lib/security/pam_winbind.so
+login	auth required 	/usr/lib/security/$ISA/pam_unix.so.1 try_first_pass 
+login	auth required 	/usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass 
+#
+rlogin  auth sufficient /usr/lib/security/pam_winbind.so
+rlogin  auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1
+rlogin	auth required 	/usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
+#
+dtlogin auth sufficient /usr/lib/security/pam_winbind.so
+dtlogin	auth required 	/usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
+#
+rsh	auth required	/usr/lib/security/$ISA/pam_rhosts_auth.so.1
+other   auth sufficient /usr/lib/security/pam_winbind.so
+other	auth required	/usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
+#
+# Account management
+#
+login   account sufficient      /usr/lib/security/pam_winbind.so
+login	account requisite	/usr/lib/security/$ISA/pam_roles.so.1 
+login	account required	/usr/lib/security/$ISA/pam_unix.so.1 
+#
+dtlogin account sufficient      /usr/lib/security/pam_winbind.so
+dtlogin	account requisite	/usr/lib/security/$ISA/pam_roles.so.1 
+dtlogin	account required	/usr/lib/security/$ISA/pam_unix.so.1 
+#
+other   account sufficient      /usr/lib/security/pam_winbind.so
+other	account requisite	/usr/lib/security/$ISA/pam_roles.so.1 
+other	account required	/usr/lib/security/$ISA/pam_unix.so.1 
+#
+# Session management
+#
+other	session required	/usr/lib/security/$ISA/pam_unix.so.1 
+#
+# Password management
+#
+#other   password sufficient     /usr/lib/security/pam_winbind.so
+other	password required	/usr/lib/security/$ISA/pam_unix.so.1 
+dtsession auth required	/usr/lib/security/$ISA/pam_unix.so.1
+#
+# Support for Kerberos V5 authentication (uncomment to use Kerberos)
+#
+#rlogin	auth optional	/usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
+#login	auth optional	/usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
+#dtlogin	auth optional	/usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
+#other	auth optional	/usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
+#dtlogin	account optional /usr/lib/security/$ISA/pam_krb5.so.1
+#other	account optional /usr/lib/security/$ISA/pam_krb5.so.1
+#other	session optional /usr/lib/security/$ISA/pam_krb5.so.1
+#other	password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass

    This method, which was introduced in Samba 2.0.6, - allows Samba to use exactly the same mechanism that NT does. This - method either broadcasts or uses a WINS database in order to - find domain controllers to authenticate against.

    I also added a try_first_pass line after the winbind.so line to get rid of +annoying double prompts for passwords.

    Finally, restart your Samba daemons and get ready for - clients to begin using domain security!

    Now restart your Samba & try connecting through your application that you +configured in the pam.conf.

    7.2. Samba and Windows 2000 Domains11.6. Limitations

    Many people have asked regarding the state of Samba's ability to participate in -a Windows 2000 Domain. Samba 2.2 is able to act as a member server of a Windows -2000 domain operating in mixed or native mode.

    Winbind has a number of limitations in its current + released version that we hope to overcome in future + releases:

    There is much confusion between the circumstances that require a "mixed" mode -Win2k DC and a when this host can be switched to "native" mode. A "mixed" mode -Win2k domain controller is only needed if Windows NT BDCs must exist in the same -domain. By default, a Win2k DC in "native" mode will still support -NetBIOS and NTLMv1 for authentication of legacy clients such as Windows 9x and -NT 4.0. Samba has the same requirements as a Windows NT 4.0 member server.

    7.3. Why is this better than security = server?11.7. Conclusion

    Currently, domain security in Samba doesn't free you from - having to create local Unix users to represent the users attaching - to your server. This means that if domain user DOM\fred - attaches to your domain security Samba server, there needs - to be a local Unix user fred to represent that user in the Unix - filesystem. This is very similar to the older Samba security mode - security = server, - where Samba would pass through the authentication request to a Windows - NT server in the same way as a Windows 95 or Windows 98 server would. -

    Please refer to the Winbind - paper for information on a system to automatically - assign UNIX uids and gids to Windows NT Domain users and groups. - This code is available in development branches only at the moment, - but will be moved to release branches soon.

    The advantage to domain-level security is that the - authentication in domain-level security is passed down the authenticated - RPC channel in exactly the same way that an NT server would do it. This - means Samba servers now participate in domain trust relationships in - exactly the same way NT servers do (i.e., you can add Samba servers into - a resource domain and have the authentication passed on from a resource - domain PDC to an account domain PDC.

    In addition, with security = server every Samba - daemon on a server has to keep a connection open to the - authenticating server for as long as that daemon lasts. This can drain - the connection resources on a Microsoft NT server and cause it to run - out of available connections. With security = domain, - however, the Samba daemons connect to the PDC/BDC only for as long - as is necessary to authenticate the user, and then drop the connection, - thus conserving PDC connection resources.

    And finally, acting in the same manner as an NT server - authenticating to a PDC means that as part of the authentication - reply, the Samba server gets the user identification information such - as the user SID, the list of NT groups the user belongs to, etc. All - this information will allow Samba to be extended in the future into - a mode the developers currently call appliance mode. In this mode, - no local Unix users will be necessary, and Samba will generate Unix - uids and gids from the information passed back from the PDC when a - user is authenticated, making a Samba server truly plug and play - in an NT domain environment. Watch for this code soon.

    NOTE: Much of the text of this document - was first published in the Web magazine - LinuxWorld as the article Doing - the NIS/NT Samba.

    The winbind system, through the use of the Name Service + Switch, Pluggable Authentication Modules, and appropriate + Microsoft RPC calls have allowed us to provide seamless + integration of Microsoft Windows NT domain users on a + UNIX system. The result is a great reduction in the administrative + cost of running a mixed UNIX and NT network.

    Chapter 8. How to Configure Samba 2.2 as a Primary Domain ControllerChapter 12. How to Configure Samba 2.2 as a Primary Domain Controller

    8.1. Prerequisite Reading12.1. Prerequisite Reading

    Before you continue reading in this chapter, please make sure @@ -5706,8 +8896,8 @@ CLASS="SECT1" >

    8.2. Background12.2. Background

    8.3. Configuring the Samba Domain Controller12.3. Configuring the Samba Domain Controller

    The first step in creating a working Samba PDC is to @@ -6059,8 +9249,8 @@ CLASS="SECT1" >

    8.4. Creating Machine Trust Accounts and Joining Clients to the +NAME="AEN1823" +>12.4. Creating Machine Trust Accounts and Joining Clients to the Domain

    8.4.1. Manual Creation of Machine Trust Accounts12.4.1. Manual Creation of Machine Trust Accounts

    The first step in manually creating a machine trust account is to @@ -6300,8 +9490,8 @@ CLASS="SECT2" >

    8.4.2. "On-the-Fly" Creation of Machine Trust Accounts12.4.2. "On-the-Fly" Creation of Machine Trust Accounts

    The second (and recommended) way of creating machine trust accounts is @@ -6346,8 +9536,8 @@ CLASS="SECT2" >

    8.4.3. Joining the Client to the Domain12.4.3. Joining the Client to the Domain

    The procedure for joining a client to the domain varies with the @@ -6406,8 +9596,8 @@ CLASS="SECT1" >

    8.5. Common Problems and Errors12.5. Common Problems and Errors

    8.6. System Policies and Profiles12.6. System Policies and Profiles

    Much of the information necessary to implement System Policies and @@ -6762,8 +9952,8 @@ CLASS="SECT1" >

    8.7. What other help can I get?12.7. What other help can I get?

    There are many sources of information available in the form @@ -7158,8 +10348,8 @@ CLASS="SECT1" >

    8.8. Domain Control for Windows 9x/ME12.8. Domain Control for Windows 9x/ME

    8.8.1. Configuration Instructions: Network Logons12.8.1. Configuration Instructions: Network Logons

    The main difference between a PDC and a Windows 9x logon @@ -7366,8 +10556,8 @@ CLASS="SECT2" >

    8.8.2. Configuration Instructions: Setting up Roaming User Profiles12.8.2. Configuration Instructions: Setting up Roaming User Profiles

    8.8.2.1. Windows NT Configuration12.8.2.1. Windows NT Configuration

    To support WinNT clients, in the [global] section of smb.conf set the @@ -7457,8 +10647,8 @@ CLASS="SECT3" >

    8.8.2.2. Windows 9X Configuration12.8.2.2. Windows 9X Configuration

    To support Win9X clients, you must use the "logon home" parameter. Samba has @@ -7497,8 +10687,8 @@ CLASS="SECT3" >

    8.8.2.3. Win9X and WinNT Configuration12.8.2.3. Win9X and WinNT Configuration

    You can support profiles for both Win9X and WinNT clients by setting both the @@ -7535,8 +10725,8 @@ CLASS="SECT3" >

    8.8.2.4. Windows 9X Profile Setup12.8.2.4. Windows 9X Profile Setup

    When a user first logs in on Windows 9X, the file user.DAT is created, @@ -7691,8 +10881,8 @@ CLASS="SECT3" >

    8.8.2.5. Windows NT Workstation 4.012.8.2.5. Windows NT Workstation 4.0

    When a user first logs in to a Windows NT Workstation, the profile @@ -7773,8 +10963,8 @@ CLASS="SECT3" >

    8.8.2.6. Windows NT Server12.8.2.6. Windows NT Server

    There is nothing to stop you specifying any path that you like for the @@ -7787,8 +10977,8 @@ CLASS="SECT3" >

    8.8.2.7. Sharing Profiles between W95 and NT Workstation 4.012.8.2.7. Sharing Profiles between W95 and NT Workstation 4.0

    The default logon path is \\%N\U%. NT Workstation will attempt to create +>The default logon path is \\%N\%U. NT Workstation will attempt to create a directory "\\samba-server\username.PDS" if you specify the logon path as "\\samba-server\username" with the NT User Manager. Therefore, you will need to specify (for example) "\\samba-server\username\profile". @@ -7852,8 +11042,8 @@ CLASS="SECT1" >

    8.9. DOMAIN_CONTROL.txt : Windows NT Domain Control & Samba12.9. DOMAIN_CONTROL.txt : Windows NT Domain Control & Samba

    Chapter 9. How to Act as a Backup Domain Controller in a Purely Samba Controlled DomainChapter 13. How to Act as a Backup Domain Controller in a Purely Samba Controlled Domain

    9.1. Prerequisite Reading13.1. Prerequisite Reading

    Before you continue reading in this chapter, please make sure @@ -7998,8 +11188,8 @@ CLASS="SECT1" >

    9.2. Background13.2. Background

    What is a Domain Controller? It is a machine that is able to answer @@ -8052,8 +11242,8 @@ CLASS="SECT1" >

    9.3. What qualifies a Domain Controller on the network?13.3. What qualifies a Domain Controller on the network?

    Every machine that is a Domain Controller for the domain SAMBA has to @@ -8069,8 +11259,8 @@ CLASS="SECT2" >

    9.3.1. How does a Workstation find its domain controller?13.3.1. How does a Workstation find its domain controller?

    A NT workstation in the domain SAMBA that wants a local user to be @@ -8088,8 +11278,8 @@ CLASS="SECT2" >

    9.3.2. When is the PDC needed?13.3.2. When is the PDC needed?

    Whenever a user wants to change his password, this has to be done on @@ -8104,8 +11294,8 @@ CLASS="SECT1" >

    9.4. Can Samba be a Backup Domain Controller?13.4. Can Samba be a Backup Domain Controller?

    With version 2.2, no. The native NT SAM replication protocols have @@ -8123,8 +11313,8 @@ CLASS="SECT1" >

    9.5. How do I set up a Samba BDC?13.5. How do I set up a Samba BDC?

    Several things have to be done:

    9.5.1. How do I replicate the smbpasswd file?13.5.1. How do I replicate the smbpasswd file?

    Replication of the smbpasswd file is sensitive. It has to be done @@ -8216,15 +11406,15 @@ CLASS="CHAPTER" >

    Chapter 10. Storing Samba's User/Machine Account information in an LDAP DirectoryChapter 14. Storing Samba's User/Machine Account information in an LDAP Directory

    10.1. Purpose14.1. Purpose

    This document describes how to use an LDAP directory for storing Samba user @@ -8291,8 +11481,8 @@ CLASS="SECT1" >

    10.2. Introduction14.2. Introduction

    Traditionally, when configuring

    10.3. Supported LDAP Servers14.3. Supported LDAP Servers

    The LDAP samdb code in 2.2.3 has been developed and tested using the OpenLDAP @@ -8433,8 +11623,8 @@ CLASS="SECT1" >

    10.4. Schema and Relationship to the RFC 2307 posixAccount14.4. Schema and Relationship to the RFC 2307 posixAccount

    Samba 2.2.3 includes the necessary schema file for OpenLDAP 2.0 in @@ -8501,16 +11691,16 @@ CLASS="SECT1" >

    10.5. Configuring Samba with LDAP14.5. Configuring Samba with LDAP

    10.5.1. OpenLDAP configuration14.5.1. OpenLDAP configuration

    To include support for the sambaAccount object in an OpenLDAP directory @@ -8560,266 +11750,21 @@ include /etc/openldap/schema/core.schema ## needed for sambaAccount include /etc/openldap/schema/cosine.schema -include /etc/openldap/schema/inetorgperson.schema -include /etc/openldap/schema/samba.schema - -## uncomment this line if you want to support the RFC2307 (NIS) schema -## include /etc/openldap/schema/nis.schema - -....

    It is recommended that you maintain some indices on some of the most usefull attributes, -like in the following example, to speed up searches made on sambaAccount objectclasses -(and possibly posixAccount and posixGroup as well).

    # Indices to maintain
-## required by OpenLDAP 2.0
-index objectclass   eq
-
-## support pb_getsampwnam()
-index uid           pres,eq
-## support pdb_getsambapwrid()
-index rid           eq
-
-## uncomment these if you are storing posixAccount and
-## posixGroup entries in the directory as well
-##index uidNumber     eq
-##index gidNumber     eq
-##index cn            eq
-##index memberUid     eq

    10.5.2. Configuring Samba

    The following parameters are available in smb.conf only with --with-ldapsam -was included with compiling Samba.

    These are described in the smb.conf(5) man -page and so will not be repeated here. However, a sample smb.conf file for -use with an LDAP directory could appear as

    ## /usr/local/samba/lib/smb.conf
-[global]
-     security = user
-     encrypt passwords = yes
-
-     netbios name = TASHTEGO
-     workgroup = NARNIA
-
-     # ldap related parameters
-
-     # define the DN to use when binding to the directory servers
-     # The password for this DN is not stored in smb.conf.  Rather it
-     # must be set by using 'smbpasswd -w secretpw' to store the
-     # passphrase in the secrets.tdb file.  If the "ldap admin dn" values
-     # changes, this password will need to be reset.
-     ldap admin dn = "cn=Samba Manager,ou=people,dc=samba,dc=org"
-
-     #  specify the LDAP server's hostname (defaults to locahost)
-     ldap server = ahab.samba.org
-
-     # Define the SSL option when connecting to the directory
-     # ('off', 'start tls', or 'on' (default))
-     ldap ssl = start tls
-
-     # define the port to use in the LDAP session (defaults to 636 when
-     # "ldap ssl = on")
-     ldap port = 389
-
-     # specify the base DN to use when searching the directory
-     ldap suffix = "ou=people,dc=samba,dc=org"
-
-     # generally the default ldap search filter is ok
-     # ldap filter = "(&(uid=%u)(objectclass=sambaAccount))"

    10.6. Accounts and Groups management

    As users accounts are managed thru the sambaAccount objectclass, you should -modify you existing administration tools to deal with sambaAccount attributes.

    Machines accounts are managed with the sambaAccount objectclass, just -like users accounts. However, it's up to you to stored thoses accounts -in a different tree of you LDAP namespace: you should use -"ou=Groups,dc=plainjoe,dc=org" to store groups and -"ou=People,dc=plainjoe,dc=org" to store users. Just configure your -NSS and PAM accordingly (usually, in the /etc/ldap.conf configuration -file).

    In Samba release 2.2.3, the group management system is based on posix -groups. This meand that Samba make usage of the posixGroup objectclass. -For now, there is no NT-like group system management (global and local -groups).

    10.7. Security and sambaAccount

    There are two important points to remember when discussing the security -of sambaAccount entries in the directory.

    • Never retrieve the lmPassword or - ntPassword attribute values over an unencrypted LDAP session.

    • Never allow non-admin users to - view the lmPassword or ntPassword attribute values.

    These password hashes are clear text equivalents and can be used to impersonate -the user without deriving the original clear text strings. For more information -on the details of LM/NT password hashes, refer to the ENCRYPTION chapter of the Samba-HOWTO-Collection.

    To remedy the first security issue, the "ldap ssl" smb.conf parameter defaults -to require an encrypted session (ldap ssl = on) using -the default port of 636 -when contacting the directory server. When using an OpenLDAP 2.0 server, it -is possible to use the use the StartTLS LDAP extended operation in the place of -LDAPS. In either case, you are strongly discouraged to disable this security -(ldap ssl = off).

    Note that the LDAPS protocol is deprecated in favor of the LDAPv3 StartTLS -extended operation. However, the OpenLDAP library still provides support for -the older method of securing communication between clients and servers.

    The second security precaution is to prevent non-administrative users from -harvesting password hashes from the directory. This can be done using the -following ACL in slapd.conf:

    It is recommended that you maintain some indices on some of the most usefull attributes, +like in the following example, to speed up searches made on sambaAccount objectclasses +(and possibly posixAccount and posixGroup as well).

    ## allow the "ldap admin dn" access, but deny everyone else
-access to attrs=lmPassword,ntPassword
-     by dn="cn=Samba Admin,ou=people,dc=plainjoe,dc=org" write
-     by * none
    # Indices to maintain +## required by OpenLDAP 2.0 +index objectclass eq + +## support pb_getsampwnam() +index uid pres,eq +## support pdb_getsambapwrid() +index rid eq + +## uncomment these if you are storing posixAccount and +## posixGroup entries in the directory as well +##index uidNumber eq +##index gidNumber eq +##index cn eq +##index memberUid eq

    10.8. LDAP specials attributes for sambaAccounts

    14.5.2. Configuring Samba

    The sambaAccount objectclass is composed of the following attributes:

    The following parameters are available in smb.conf only with --with-ldapsam +was included with compiling Samba.

    • lmPassword: the LANMAN password 16-byte hash stored as a character - representation of a hexidecimal string.

    • ntPassword: the NT password hash 16-byte stored as a character - representation of a hexidecimal string.

    • pwdLastSet: The integer time in seconds since 1970 when the - lmPassword and ntPassword attributes were last set. -

    • acctFlags: string of 11 characters surrounded by square brackets [] - representing account flags such as U (user), W(workstation), X(no password expiration), and - D(disabled).

    • logonTime: Integer value currently unused

    • logoffTime: Integer value currently unused

    • kickoffTime: Integer value currently unused

    • pwdCanChange: Integer value currently unused

    • pwdMustChange: Integer value currently unused

    • homeDrive: specifies the drive letter to which to map the - UNC path specified by homeDirectory. The drive letter must be specified in the form "X:" - where X is the letter of the drive to map. Refer to the "logon drive" parameter in the - smb.conf(5) man page for more information.

    • scriptPath: The scriptPath property specifies the path of - the user's logon script, .CMD, .EXE, or .BAT file. The string can be null. The path - is relative to the netlogon share. Refer to the "logon script" parameter in the - smb.conf(5) man page for more information.

    • profilePath: specifies a path to the user's profile. - This value can be a null string, a local absolute path, or a UNC path. Refer to the - "logon path" parameter in the smb.conf(5) man page for more information.

    • smbHome: The homeDirectory property specifies the path of - the home directory for the user. The string can be null. If homeDrive is set and specifies - a drive letter, homeDirectory should be a UNC path. The path must be a network - UNC path of the form \\server\share\directory. This value can be a null string. - Refer to the "logon home" parameter in the smb.conf(5) man page for more information. -

    • userWorkstation: character string value currently unused. -

    • rid: the integer representation of the user's relative identifier - (RID).

    • primaryGroupID: the relative identifier (RID) of the primary group - of the user.

    The majority of these parameters are only used when Samba is acting as a PDC of -a domain (refer to the Samba-PDC-HOWTO for details on -how to configure Samba as a Primary Domain Controller). The following four attributes -are only stored with the sambaAccount entry if the values are non-default values:

    ldap ssl

  • ldap server

    • smbHome

    • scriptPath

    • logonPath

    • homeDrive

    These attributes are only stored with the sambaAccount entry if -the values are non-default values. For example, assume TASHTEGO has now been -configured as a PDC and that logon home = \\%L\%u was defined in -its smb.conf file. When a user named "becky" logons to the domain, -the logon home string is expanded to \\TASHTEGO\becky. -If the smbHome attribute exists in the entry "uid=becky,ou=people,dc=samba,dc=org", -this value is used. However, if this attribute does not exist, then the value -of the logon home parameter is used in its place. Samba -will only write the attribute value to the directory entry is the value is -something other than the default (e.g. \\MOBY\becky).

    • 10.9. Example LDIF Entries for a sambaAccount

    ldap admin dn

  • The following is a working LDIF with the inclusion of the posixAccount objectclass:

    ldap suffix

  • dn: uid=guest2, ou=people,dc=plainjoe,dc=org
-ntPassword: 878D8014606CDA29677A44EFA1353FC7
-pwdMustChange: 2147483647
-primaryGroupID: 1201
-lmPassword: 552902031BEDE9EFAAD3B435B51404EE
-pwdLastSet: 1010179124
-logonTime: 0
-objectClass: sambaAccount
-uid: guest2
-kickoffTime: 2147483647
-acctFlags: [UX         ]
-logoffTime: 2147483647
-rid: 19006
-pwdCanChange: 0
    ldap filter

  • The following is an LDIF entry for using both the sambaAccount and -posixAccount objectclasses:

    ldap port

    • These are described in the smb.conf(5) man +page and so will not be repeated here. However, a sample smb.conf file for +use with an LDAP directory could appear as

    dn: uid=gcarter, ou=people,dc=plainjoe,dc=org
-logonTime: 0
-displayName: Gerald Carter
-lmPassword: 552902031BEDE9EFAAD3B435B51404EE
-primaryGroupID: 1201
-objectClass: posixAccount
-objectClass: sambaAccount
-acctFlags: [UX         ]
-userPassword: {crypt}BpM2ej8Rkzogo
-uid: gcarter
-uidNumber: 9000
-cn: Gerald Carter
-loginShell: /bin/bash
-logoffTime: 2147483647
-gidNumber: 100
-kickoffTime: 2147483647
-pwdLastSet: 1010179230
-rid: 19000
-homeDirectory: /home/tashtego/gcarter
-pwdCanChange: 0
-pwdMustChange: 2147483647
-ntPassword: 878D8014606CDA29677A44EFA1353FC7
    ## /usr/local/samba/lib/smb.conf +[global] + security = user + encrypt passwords = yes + + netbios name = TASHTEGO + workgroup = NARNIA + + # ldap related parameters + + # define the DN to use when binding to the directory servers + # The password for this DN is not stored in smb.conf. Rather it + # must be set by using 'smbpasswd -w secretpw' to store the + # passphrase in the secrets.tdb file. If the "ldap admin dn" values + # changes, this password will need to be reset. + ldap admin dn = "cn=Samba Manager,ou=people,dc=samba,dc=org" + + # specify the LDAP server's hostname (defaults to locahost) + ldap server = ahab.samba.org + + # Define the SSL option when connecting to the directory + # ('off', 'start tls', or 'on' (default)) + ldap ssl = start tls + + # define the port to use in the LDAP session (defaults to 636 when + # "ldap ssl = on") + ldap port = 389 + + # specify the base DN to use when searching the directory + ldap suffix = "ou=people,dc=samba,dc=org" + + # generally the default ldap search filter is ok + # ldap filter = "(&(uid=%u)(objectclass=sambaAccount))"

    10.10. Comments14.6. Accounts and Groups management

    Please mail all comments regarding this HOWTO to jerry@samba.org. This documents was -last updated to reflect the Samba 2.2.3 release.

    Chapter 11. Unified Logons between Windows NT and UNIX using Winbind

    11.1. Abstract

    As users accounts are managed thru the sambaAccount objectclass, you should +modify you existing administration tools to deal with sambaAccount attributes.

    Integration of UNIX and Microsoft Windows NT through - a unified logon has been considered a "holy grail" in heterogeneous - computing environments for a long time. We present - winbind, a component of the Samba suite - of programs as a solution to the unified logon problem. Winbind - uses a UNIX implementation - of Microsoft RPC calls, Pluggable Authentication Modules, and the Name - Service Switch to allow Windows NT domain users to appear and operate - as UNIX users on a UNIX machine. This paper describes the winbind - system, explaining the functionality it provides, how it is configured, - and how it works internally.

    Machines accounts are managed with the sambaAccount objectclass, just +like users accounts. However, it's up to you to stored thoses accounts +in a different tree of you LDAP namespace: you should use +"ou=Groups,dc=plainjoe,dc=org" to store groups and +"ou=People,dc=plainjoe,dc=org" to store users. Just configure your +NSS and PAM accordingly (usually, in the /etc/ldap.conf configuration +file).

    In Samba release 2.2.3, the group management system is based on posix +groups. This meand that Samba make usage of the posixGroup objectclass. +For now, there is no NT-like group system management (global and local +groups).

    11.2. Introduction14.7. Security and sambaAccount

    It is well known that UNIX and Microsoft Windows NT have - different models for representing user and group information and - use different technologies for implementing them. This fact has - made it difficult to integrate the two systems in a satisfactory - manner.

    There are two important points to remember when discussing the security +of sambaAccount entries in the directory.

    One common solution in use today has been to create - identically named user accounts on both the UNIX and Windows systems - and use the Samba suite of programs to provide file and print services - between the two. This solution is far from perfect however, as - adding and deleting users on both sets of machines becomes a chore - and two sets of passwords are required both of which - can lead to synchronization problems between the UNIX and Windows - systems and confusion for users.

    • Never retrieve the lmPassword or + ntPassword attribute values over an unencrypted LDAP session.

    • Never allow non-admin users to + view the lmPassword or ntPassword attribute values.

    These password hashes are clear text equivalents and can be used to impersonate +the user without deriving the original clear text strings. For more information +on the details of LM/NT password hashes, refer to the ENCRYPTION chapter of the Samba-HOWTO-Collection.

    To remedy the first security issue, the "ldap ssl" smb.conf parameter defaults +to require an encrypted session (ldap ssl = on) using +the default port of 636 +when contacting the directory server. When using an OpenLDAP 2.0 server, it +is possible to use the use the StartTLS LDAP extended operation in the place of +LDAPS. In either case, you are strongly discouraged to disable this security +(ldap ssl = off).

    Note that the LDAPS protocol is deprecated in favor of the LDAPv3 StartTLS +extended operation. However, the OpenLDAP library still provides support for +the older method of securing communication between clients and servers.

    The second security precaution is to prevent non-administrative users from +harvesting password hashes from the directory. This can be done using the +following ACL in slapd.conf:

    ## allow the "ldap admin dn" access, but deny everyone else
+access to attrs=lmPassword,ntPassword
+     by dn="cn=Samba Admin,ou=people,dc=plainjoe,dc=org" write
+     by * none

    14.8. LDAP specials attributes for sambaAccounts

    We divide the unified logon problem for UNIX machines into - three smaller problems:

    The sambaAccount objectclass is composed of the following attributes:

    • Obtaining Windows NT user and group information -

      lmPassword: the LANMAN password 16-byte hash stored as a character + representation of a hexidecimal string.

    • Authenticating Windows NT users -

      ntPassword: the NT password hash 16-byte stored as a character + representation of a hexidecimal string.

    • Password changing for Windows NT users -

      pwdLastSet: The integer time in seconds since 1970 when the + lmPassword and ntPassword attributes were last set. +

    Ideally, a prospective solution to the unified logon problem - would satisfy all the above components without duplication of - information on the UNIX machines and without creating additional - tasks for the system administrator when maintaining users and - groups on either system. The winbind system provides a simple - and elegant solution to all three components of the unified logon - problem.

    11.3. What Winbind Provides

  • Winbind unifies UNIX and Windows NT account management by - allowing a UNIX box to become a full member of a NT domain. Once - this is done the UNIX box will see NT users and groups as if - they were native UNIX users and groups, allowing the NT domain - to be used in much the same manner that NIS+ is used within - UNIX-only environments.

    acctFlags: string of 11 characters surrounded by square brackets [] + representing account flags such as U (user), W(workstation), X(no password expiration), and + D(disabled).

  • The end result is that whenever any - program on the UNIX machine asks the operating system to lookup - a user or group name, the query will be resolved by asking the - NT domain controller for the specified domain to do the lookup. - Because Winbind hooks into the operating system at a low level - (via the NSS name resolution modules in the C library) this - redirection to the NT domain controller is completely - transparent.

    logonTime: Integer value currently unused

  • Users on the UNIX machine can then use NT user and group - names as they would use "native" UNIX names. They can chown files - so that they are owned by NT domain users or even login to the - UNIX machine and run a UNIX X-Window session as a domain user.

    logoffTime: Integer value currently unused

  • The only obvious indication that Winbind is being used is - that user and group names take the form DOMAIN\user and - DOMAIN\group. This is necessary as it allows Winbind to determine - that redirection to a domain controller is wanted for a particular - lookup and which trusted domain is being referenced.

    kickoffTime: Integer value currently unused

  • Additionally, Winbind provides an authentication service - that hooks into the Pluggable Authentication Modules (PAM) system - to provide authentication via a NT domain to any PAM enabled - applications. This capability solves the problem of synchronizing - passwords between systems since all passwords are stored in a single - location (on the domain controller).

    11.3.1. Target Uses

    pwdCanChange: Integer value currently unused

  • Winbind is targeted at organizations that have an - existing NT based domain infrastructure into which they wish - to put UNIX workstations or servers. Winbind will allow these - organizations to deploy UNIX workstations without having to - maintain a separate account infrastructure. This greatly - simplifies the administrative overhead of deploying UNIX - workstations into a NT based organization.

    pwdMustChange: Integer value currently unused

  • Another interesting way in which we expect Winbind to - be used is as a central part of UNIX based appliances. Appliances - that provide file and print services to Microsoft based networks - will be able to use Winbind to provide seamless integration of - the appliance into the domain.

    • 11.4. How Winbind Works

    homeDrive: specifies the drive letter to which to map the + UNC path specified by homeDirectory. The drive letter must be specified in the form "X:" + where X is the letter of the drive to map. Refer to the "logon drive" parameter in the + smb.conf(5) man page for more information.

  • The winbind system is designed around a client/server - architecture. A long running winbindd daemon - listens on a UNIX domain socket waiting for requests - to arrive. These requests are generated by the NSS and PAM - clients and processed sequentially.

    scriptPath: The scriptPath property specifies the path of + the user's logon script, .CMD, .EXE, or .BAT file. The string can be null. The path + is relative to the netlogon share. Refer to the "logon script" parameter in the + smb.conf(5) man page for more information.

  • The technologies used to implement winbind are described - in detail below.

    11.4.1. Microsoft Remote Procedure Calls

    profilePath: specifies a path to the user's profile. + This value can be a null string, a local absolute path, or a UNC path. Refer to the + "logon path" parameter in the smb.conf(5) man page for more information.

  • Over the last two years, efforts have been underway - by various Samba Team members to decode various aspects of - the Microsoft Remote Procedure Call (MSRPC) system. This - system is used for most network related operations between - Windows NT machines including remote management, user authentication - and print spooling. Although initially this work was done - to aid the implementation of Primary Domain Controller (PDC) - functionality in Samba, it has also yielded a body of code which - can be used for other purposes.

    smbHome: The homeDirectory property specifies the path of + the home directory for the user. The string can be null. If homeDrive is set and specifies + a drive letter, homeDirectory should be a UNC path. The path must be a network + UNC path of the form \\server\share\directory. This value can be a null string. + Refer to the "logon home" parameter in the smb.conf(5) man page for more information. +

  • Winbind uses various MSRPC calls to enumerate domain users - and groups and to obtain detailed information about individual - users or groups. Other MSRPC calls can be used to authenticate - NT domain users and to change user passwords. By directly querying - a Windows PDC for user and group information, winbind maps the - NT account information onto UNIX user and group names.

    • 11.4.2. Name Service Switch

    userWorkstation: character string value currently unused. +

  • The Name Service Switch, or NSS, is a feature that is - present in many UNIX operating systems. It allows system - information such as hostnames, mail aliases and user information - to be resolved from different sources. For example, a standalone - UNIX workstation may resolve system information from a series of - flat files stored on the local filesystem. A networked workstation - may first attempt to resolve system information from local files, - and then consult a NIS database for user information or a DNS server - for hostname information.

    rid: the integer representation of the user's relative identifier + (RID).

  • The NSS application programming interface allows winbind - to present itself as a source of system information when - resolving UNIX usernames and groups. Winbind uses this interface, - and information obtained from a Windows NT server using MSRPC - calls to provide a new source of account enumeration. Using standard - UNIX library calls, one can enumerate the users and groups on - a UNIX machine running winbind and see all users and groups in - a NT domain plus any trusted domain as though they were local - users and groups.

    primaryGroupID: the relative identifier (RID) of the primary group + of the user.

    • The primary control file for NSS is - /etc/nsswitch.conf. - When a UNIX application makes a request to do a lookup - the C library looks in /etc/nsswitch.conf - for a line which matches the service type being requested, for - example the "passwd" service type is used when user or group names - are looked up. This config line species which implementations - of that service should be tried and in what order. If the passwd - config line is:

    The majority of these parameters are only used when Samba is acting as a PDC of +a domain (refer to the Samba-PDC-HOWTO for details on +how to configure Samba as a Primary Domain Controller). The following four attributes +are only stored with the sambaAccount entry if the values are non-default values:

    passwd: files example

    • then the C library will first load a module called - /lib/libnss_files.so followed by - the module /lib/libnss_example.so. The - C library will dynamically load each of these modules in turn - and call resolver functions within the modules to try to resolve - the request. Once the request is resolved the C library returns the - result to the application.

      smbHome

    • This NSS interface provides a very easy way for Winbind - to hook into the operating system. All that needs to be done - is to put libnss_winbind.so in /lib/ - then add "winbind" into /etc/nsswitch.conf at - the appropriate place. The C library will then call Winbind to - resolve user and group names.

    11.4.3. Pluggable Authentication Modules

    scriptPath

  • Pluggable Authentication Modules, also known as PAM, - is a system for abstracting authentication and authorization - technologies. With a PAM module it is possible to specify different - authentication methods for different system applications without - having to recompile these applications. PAM is also useful - for implementing a particular policy for authorization. For example, - a system administrator may only allow console logins from users - stored in the local password file but only allow users resolved from - a NIS database to log in over the network.

    logonPath

  • Winbind uses the authentication management and password - management PAM interface to integrate Windows NT users into a - UNIX system. This allows Windows NT users to log in to a UNIX - machine and be authenticated against a suitable Primary Domain - Controller. These users can also change their passwords and have - this change take effect directly on the Primary Domain Controller. -

    homeDrive

    • PAM is configured by providing control files in the directory - /etc/pam.d/ for each of the services that - require authentication. When an authentication request is made - by an application the PAM code in the C library looks up this - control file to determine what modules to load to do the - authentication check and in what order. This interface makes adding - a new authentication service for Winbind very easy, all that needs - to be done is that the pam_winbind.so module - is copied to These attributes are only stored with the sambaAccount entry if +the values are non-default values. For example, assume TASHTEGO has now been +configured as a PDC and that logon home = \\%L\%u was defined in +its /lib/security/ and the PAM - control files for relevant services are updated to allow - authentication via winbind. See the PAM documentation - for more details.

    smb.conf file. When a user named "becky" logons to the domain, +the logon home string is expanded to \\TASHTEGO\becky. +If the smbHome attribute exists in the entry "uid=becky,ou=people,dc=samba,dc=org", +this value is used. However, if this attribute does not exist, then the value +of the logon home parameter is used in its place. Samba +will only write the attribute value to the directory entry is the value is +something other than the default (e.g. \\MOBY\becky).

    11.4.4. User and Group ID Allocation

    14.9. Example LDIF Entries for a sambaAccount

    When a user or group is created under Windows NT - is it allocated a numerical relative identifier (RID). This is - slightly different to UNIX which has a range of numbers that are - used to identify users, and the same range in which to identify - groups. It is winbind's job to convert RIDs to UNIX id numbers and - vice versa. When winbind is configured it is given part of the UNIX - user id space and a part of the UNIX group id space in which to - store Windows NT users and groups. If a Windows NT user is - resolved for the first time, it is allocated the next UNIX id from - the range. The same process applies for Windows NT groups. Over - time, winbind will have mapped all Windows NT users and groups - to UNIX user ids and group ids.

    The following is a working LDIF with the inclusion of the posixAccount objectclass:

    The results of this mapping are stored persistently in - an ID mapping database held in a tdb database). This ensures that - RIDs are mapped to UNIX IDs in a consistent way.

    11.4.5. Result Caching

    dn: uid=guest2, ou=people,dc=plainjoe,dc=org
+ntPassword: 878D8014606CDA29677A44EFA1353FC7
+pwdMustChange: 2147483647
+primaryGroupID: 1201
+lmPassword: 552902031BEDE9EFAAD3B435B51404EE
+pwdLastSet: 1010179124
+logonTime: 0
+objectClass: sambaAccount
+uid: guest2
+kickoffTime: 2147483647
+acctFlags: [UX         ]
+logoffTime: 2147483647
+rid: 19006
+pwdCanChange: 0

    An active system can generate a lot of user and group - name lookups. To reduce the network cost of these lookups winbind - uses a caching scheme based on the SAM sequence number supplied - by NT domain controllers. User or group information returned - by a PDC is cached by winbind along with a sequence number also - returned by the PDC. This sequence number is incremented by - Windows NT whenever any user or group information is modified. If - a cached entry has expired, the sequence number is requested from - the PDC and compared against the sequence number of the cached entry. - If the sequence numbers do not match, then the cached information - is discarded and up to date information is requested directly - from the PDC.

    The following is an LDIF entry for using both the sambaAccount and +posixAccount objectclasses:

    dn: uid=gcarter, ou=people,dc=plainjoe,dc=org
+logonTime: 0
+displayName: Gerald Carter
+lmPassword: 552902031BEDE9EFAAD3B435B51404EE
+primaryGroupID: 1201
+objectClass: posixAccount
+objectClass: sambaAccount
+acctFlags: [UX         ]
+userPassword: {crypt}BpM2ej8Rkzogo
+uid: gcarter
+uidNumber: 9000
+cn: Gerald Carter
+loginShell: /bin/bash
+logoffTime: 2147483647
+gidNumber: 100
+kickoffTime: 2147483647
+pwdLastSet: 1010179230
+rid: 19000
+homeDirectory: /home/tashtego/gcarter
+pwdCanChange: 0
+pwdMustChange: 2147483647
+ntPassword: 878D8014606CDA29677A44EFA1353FC7

    11.5. Installation and Configuration14.10. Comments

    Many thanks to John Trostel Please mail all comments regarding this HOWTO to jtrostel@snapserver.com -for providing the HOWTO for this section.

    jerry@samba.org. This documents was +last updated to reflect the Samba 2.2.3 release.

    Chapter 15. Improved browsing in samba

    15.1. Overview of browsing

    This HOWTO describes how to get winbind services up and running -to control access and authenticate users on your Linux box using -the winbind services which come with SAMBA 2.2.2.

    SMB networking provides a mechanism by which clients can access a list +of machines in a network, a so-called "browse list". This list +contains machines that are ready to offer file and/or print services +to other machines within the network. Thus it does not include +machines which aren't currently able to do server tasks. The browse +list is heavily used by all SMB clients. Configuration of SMB +browsing has been problematic for some Samba users, hence this +document.

    There is also some Solaris specific information in -docs/textdocs/Solaris-Winbind-HOWTO.txt. -Future revisions of this document will incorporate that -information.

    Browsing will NOT work if name resolution from NetBIOS names to IP +addresses does not function correctly. Use of a WINS server is highly +recommended to aid the resolution of NetBIOS (SMB) names to IP addresses. +WINS allows remote segment clients to obtain NetBIOS name_type information +that can NOT be provided by any other means of name resolution.

    11.5.1. Introduction

    15.2. Browsing support in samba

    This HOWTO describes the procedures used to get winbind up and -running on my RedHat 7.1 system. Winbind is capable of providing access -and authentication control for Windows Domain users through an NT -or Win2K PDC for 'regular' services, such as telnet a nd ftp, as -well for SAMBA services.

    Samba now fully supports browsing. The browsing is supported by nmbd +and is also controlled by options in the smb.conf file (see smb.conf(5)).

    This HOWTO has been written from a 'RedHat-centric' perspective, so if -you are using another distribution, you may have to modify the instructions -somewhat to fit the way your distribution works.

    Samba can act as a local browse master for a workgroup and the ability +for samba to support domain logons and scripts is now available. See +DOMAIN.txt for more information on domain logons.

    • Samba can also act as a domain master browser for a workgroup. This +means that it will collate lists from local browse masters into a +wide area network server list. In order for browse clients to +resolve the names they may find in this list, it is recommended that +both samba and your clients use a WINS server.

      Why should I to this? -

      Note that you should NOT set Samba to be the domain master for a +workgroup that has the same name as an NT Domain: on each wide area +network, you must only ever have one domain master browser per workgroup, +regardless of whether it is NT, Samba or any other type of domain master +that is providing this service.

      This allows the SAMBA administrator to rely on the - authentication mechanisms on the NT/Win2K PDC for the authentication - of domain members. NT/Win2K users no longer need to have separate - accounts on the SAMBA server. -

    • [Note that nmbd can be configured as a WINS server, but it is not +necessary to specifically use samba as your WINS server. NTAS can +be configured as your WINS server. In a mixed NT server and +samba environment on a Wide Area Network, it is recommended that +you use the NT server's WINS server capabilities. In a samba-only +environment, it is recommended that you use one and only one nmbd +as your WINS server].

      Who should be reading this document? -

      To get browsing to work you need to run nmbd as usual, but will need +to use the "workgroup" option in smb.conf to control what workgroup +Samba becomes a part of.

      This HOWTO is designed for system administrators. If you are - implementing SAMBA on a file server and wish to (fairly easily) - integrate existing NT/Win2K users from your PDC onto the - SAMBA server, this HOWTO is for you. That said, I am no NT or PAM - expert, so you may find a better or easier way to accomplish - these tasks. -

    Samba also has a useful option for a Samba server to offer itself for +browsing on another subnet. It is recommended that this option is only +used for 'unusual' purposes: announcements over the internet, for +example. See "remote announce" in the smb.conf man page.

    11.5.2. Requirements

    15.3. Problem resolution

    If you have a samba configuration file that you are currently -using... BACK IT UP! If your system already uses PAM, -back up the /etc/pam.d directory -contents! If you haven't already made a boot disk, -MAKE ONE NOW!

    If something doesn't work then hopefully the log.nmb file will help +you track down the problem. Try a debug level of 2 or 3 for finding +problems. Also note that the current browse list usually gets stored +in text form in a file called browse.dat.

    Messing with the pam configuration files can make it nearly impossible -to log in to yourmachine. That's why you want to be able to boot back -into your machine in single user mode and restore your -/etc/pam.d back to the original state they were in if -you get frustrated with the way things are going. ;-)

    Note that if it doesn't work for you, then you should still be able to +type the server name as \\SERVER in filemanager then hit enter and +filemanager should display the list of available shares.

    The latest version of SAMBA (version 2.2.2 as of this writing), now -includes a functioning winbindd daemon. Please refer to the -main SAMBA web page or, -better yet, your closest SAMBA mirror site for instructions on -downloading the source code.

    Some people find browsing fails because they don't have the global +"guest account" set to a valid account. Remember that the IPC$ +connection that lists the shares is done as guest, and thus you must +have a valid guest account.

    To allow Domain users the ability to access SAMBA shares and -files, as well as potentially other services provided by your -SAMBA machine, PAM (pluggable authentication modules) must -be setup properly on your machine. In order to compile the -winbind modules, you should have at least the pam libraries resident -on your system. For recent RedHat systems (7.1, for instance), that -means pam-0.74-22. For best results, it is helpful to also -install the development packages in pam-devel-0.74-22.

    Also, a lot of people are getting bitten by the problem of too many +parameters on the command line of nmbd in inetd.conf. This trick is to +not use spaces between the option and the parameter (eg: -d2 instead +of -d 2), and to not use the -B and -N options. New versions of nmbd +are now far more likely to correctly find your broadcast and network +address, so in most cases these aren't needed.

    The other big problem people have is that their broadcast address, +netmask or IP address is wrong (specified with the "interfaces" option +in smb.conf)

    15.4. Browsing across subnets

    With the release of Samba 1.9.17(alpha1 and above) Samba has been +updated to enable it to support the replication of browse lists +across subnet boundaries. New code and options have been added to +achieve this. This section describes how to set this feature up +in different settings.

    To see browse lists that span TCP/IP subnets (ie. networks separated +by routers that don't pass broadcast traffic) you must set up at least +one WINS server. The WINS server acts as a DNS for NetBIOS names, allowing +NetBIOS name to IP address translation to be done by doing a direct +query of the WINS server. This is done via a directed UDP packet on +port 137 to the WINS server machine. The reason for a WINS server is +that by default, all NetBIOS name to IP address translation is done +by broadcasts from the querying machine. This means that machines +on one subnet will not be able to resolve the names of machines on +another subnet without using a WINS server.

    Remember, for browsing across subnets to work correctly, all machines, +be they Windows 95, Windows NT, or Samba servers must have the IP address +of a WINS server given to them by a DHCP server, or by manual configuration +(for Win95 and WinNT, this is in the TCP/IP Properties, under Network +settings) for Samba this is in the smb.conf file.

    11.5.3. Testing Things Out15.4.1. How does cross subnet browsing work ?

    Before starting, it is probably best to kill off all the SAMBA -related daemons running on your server. Kill off all smbd, -nmbd, and winbindd processes that may -be running. To use PAM, you will want to make sure that you have the -standard PAM package (for RedHat) which supplies the /etc/pam.d -directory structure, including the pam modules are used by pam-aware -services, several pam libraries, and the /usr/doc -and /usr/man entries for pam. Winbind built better -in SAMBA if the pam-devel package was also installed. This package includes -the header files needed to compile pam-aware applications. For instance, -my RedHat system has both pam-0.74-22 and -pam-devel-0.74-22 RPMs installed.

    11.5.3.1. Configure and compile SAMBA

    Cross subnet browsing is a complicated dance, containing multiple +moving parts. It has taken Microsoft several years to get the code +that achieves this correct, and Samba lags behind in some areas. +However, with the 1.9.17 release, Samba is capable of cross subnet +browsing when configured correctly.

    The configuration and compilation of SAMBA is pretty straightforward. -The first three steps may not be necessary depending upon -whether or not you have previously built the Samba binaries.

    Consider a network set up as follows :

    root# autoconf
-root# make clean
-root# rm config.cache
-root# ./configure --with-winbind
-root# make
-root# make install
    (DMB) + N1_A N1_B N1_C N1_D N1_E + | | | | | + ------------------------------------------------------- + | subnet 1 | + +---+ +---+ + |R1 | Router 1 Router 2 |R2 | + +---+ +---+ + | | + | subnet 2 subnet 3 | + -------------------------- ------------------------------------ + | | | | | | | | + N2_A N2_B N2_C N2_D N3_A N3_B N3_C N3_D + (WINS)

    This will, by default, install SAMBA in /usr/local/samba. -See the main SAMBA documentation if you want to install SAMBA somewhere else. -It will also build the winbindd executable and libraries.

    11.5.3.2. Configure nsswitch.conf and the -winbind libraries

    The libraries needed to run the winbindd daemon -through nsswitch need to be copied to their proper locations, so

    Consisting of 3 subnets (1, 2, 3) connected by two routers +(R1, R2) - these do not pass broadcasts. Subnet 1 has 5 machines +on it, subnet 2 has 4 machines, subnet 3 has 4 machines. Assume +for the moment that all these machines are configured to be in the +same workgroup (for simplicities sake). Machine N1_C on subnet 1 +is configured as Domain Master Browser (ie. it will collate the +browse lists for the workgroup). Machine N2_D is configured as +WINS server and all the other machines are configured to register +their NetBIOS names with it.

    As all these machines are booted up, elections for master browsers +will take place on each of the three subnets. Assume that machine +N1_C wins on subnet 1, N2_B wins on subnet 2, and N3_D wins on +subnet 3 - these machines are known as local master browsers for +their particular subnet. N1_C has an advantage in winning as the +local master browser on subnet 1 as it is set up as Domain Master +Browser.

    On each of the three networks, machines that are configured to +offer sharing services will broadcast that they are offering +these services. The local master browser on each subnet will +receive these broadcasts and keep a record of the fact that +the machine is offering a service. This list of records is +the basis of the browse list. For this case, assume that +all the machines are configured to offer services so all machines +will be on the browse list.

    For each network, the local master browser on that network is +considered 'authoritative' for all the names it receives via +local broadcast. This is because a machine seen by the local +master browser via a local broadcast must be on the same +network as the local master browser and thus is a 'trusted' +and 'verifiable' resource. Machines on other networks that +the local master browsers learn about when collating their +browse lists have not been directly seen - these records are +called 'non-authoritative'.

    At this point the browse lists look as follows (these are +the machines you would see in your network neighborhood if +you looked in it on a particular network right now).

    root# cp ../samba/source/nsswitch/libnss_winbind.so /lib
    Subnet           Browse Master   List
+------           -------------   ----
+Subnet1          N1_C            N1_A, N1_B, N1_C, N1_D, N1_E
+
+Subnet2          N2_B            N2_A, N2_B, N2_C, N2_D
+
+Subnet3          N3_D            N3_A, N3_B, N3_C, N3_D

    I also found it necessary to make the following symbolic link:

    Note that at this point all the subnets are separate, no +machine is seen across any of the subnets.

    root# ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2

    Now examine subnet 2. As soon as N2_B has become the local +master browser it looks for a Domain master browser to synchronize +its browse list with. It does this by querying the WINS server +(N2_D) for the IP address associated with the NetBIOS name +WORKGROUP>1B<. This name was registerd by the Domain master +browser (N1_C) with the WINS server as soon as it was booted.

    Now, as root you need to edit /etc/nsswitch.conf to -allow user and group entries to be visible from the winbindd -daemon. My /etc/nsswitch.conf file look like -this after editing:

    Once N2_B knows the address of the Domain master browser it +tells it that is the local master browser for subnet 2 by +sending a MasterAnnouncement packet as a UDP port 138 packet. +It then synchronizes with it by doing a NetServerEnum2 call. This +tells the Domain Master Browser to send it all the server +names it knows about. Once the domain master browser receives +the MasterAnnouncement packet it schedules a synchronization +request to the sender of that packet. After both synchronizations +are done the browse lists look like :

    	passwd:     files winbind
-	shadow:     files 
-	group:      files winbind
    Subnet Browse Master List +------ ------------- ---- +Subnet1 N1_C N1_A, N1_B, N1_C, N1_D, N1_E, + N2_A(*), N2_B(*), N2_C(*), N2_D(*) + +Subnet2 N2_B N2_A, N2_B, N2_C, N2_D + N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*) + +Subnet3 N3_D N3_A, N3_B, N3_C, N3_D + +Servers with a (*) after them are non-authoritative names.

    -The libraries needed by the winbind daemon will be automatically -entered into the ldconfig cache the next time -your system reboots, but it -is faster (and you don't need to reboot) if you do it manually:

    At this point users looking in their network neighborhood on +subnets 1 or 2 will see all the servers on both, users on +subnet 3 will still only see the servers on their own subnet.

    root# /sbin/ldconfig -v | grep winbindThe same sequence of events that occured for N2_B now occurs +for the local master browser on subnet 3 (N3_D). When it +synchronizes browse lists with the domain master browser (N1_A) +it gets both the server entries on subnet 1, and those on +subnet 2. After N3_D has synchronized with N1_C and vica-versa +the browse lists look like.

    Subnet           Browse Master   List
+------           -------------   ----
+Subnet1          N1_C            N1_A, N1_B, N1_C, N1_D, N1_E, 
+                                 N2_A(*), N2_B(*), N2_C(*), N2_D(*),
+                                 N3_A(*), N3_B(*), N3_C(*), N3_D(*)
+
+Subnet2          N2_B            N2_A, N2_B, N2_C, N2_D
+                                 N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*)
+
+Subnet3          N3_D            N3_A, N3_B, N3_C, N3_D
+                                 N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*),
+                                 N2_A(*), N2_B(*), N2_C(*), N2_D(*)
+
+Servers with a (*) after them are non-authoritative names.

    This makes libnss_winbind available to winbindd -and echos back a check to you.

    11.5.3.3. Configure smb.conf

    At this point users looking in their network neighborhood on +subnets 1 or 3 will see all the servers on all sunbets, users on +subnet 2 will still only see the servers on subnets 1 and 2, but not 3.

    Several parameters are needed in the smb.conf file to control -the behavior of winbindd. Configure -smb.conf These are described in more detail in -the winbindd(8) man page. My -smb.conf file was modified to -include the following entries in the [global] section:

    Finally, the local master browser for subnet 2 (N2_B) will sync again +with the domain master browser (N1_C) and will recieve the missing +server entries. Finally - and as a steady state (if no machines +are removed or shut off) the browse lists will look like :

    [global]
-     <...>
-     # separate domain and username with '+', like DOMAIN+username
-     winbind separator = +
-     # use uids from 10000 to 20000 for domain users
-     winbind uid = 10000-20000
-     # use gids from 10000 to 20000 for domain groups
-     winbind gid = 10000-20000
-     # allow enumeration of winbind users and groups
-     winbind enum users = yes
-     winbind enum groups = yes
-     # give winbind users a real shell (only needed if they have telnet access)
-     template homedir = /home/winnt/%D/%U
-     template shell = /bin/bash
    Subnet Browse Master List +------ ------------- ---- +Subnet1 N1_C N1_A, N1_B, N1_C, N1_D, N1_E, + N2_A(*), N2_B(*), N2_C(*), N2_D(*), + N3_A(*), N3_B(*), N3_C(*), N3_D(*) + +Subnet2 N2_B N2_A, N2_B, N2_C, N2_D + N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*) + N3_A(*), N3_B(*), N3_C(*), N3_D(*) + +Subnet3 N3_D N3_A, N3_B, N3_C, N3_D + N1_A(*), N1_B(*), N1_C(*), N1_D(*), N1_E(*), + N2_A(*), N2_B(*), N2_C(*), N2_D(*) + +Servers with a (*) after them are non-authoritative names.

    11.5.3.4. Join the SAMBA server to the PDC domain

    Enter the following command to make the SAMBA server join the -PDC domain, where DOMAIN is the name of -your Windows domain and Administrator is -a domain user who has administrative privileges in the domain.

    Synchronizations between the domain master browser and local +master browsers will continue to occur, but this should be a +steady state situation.

    If either router R1 or R2 fails the following will occur:

    root# /usr/local/samba/bin/net rpc join -s PDC -U Administrator

    1. The proper response to the command should be: "Joined the domain -DOMAIN" where DOMAIN -is your DOMAIN name.

      Names of computers on each side of the inaccessible network fragments + will be maintained for as long as 36 minutes, in the network neighbourhood + lists. +

    2. Attempts to connect to these inaccessible computers will fail, but the + names will not be removed from the network neighbourhood lists. +

    3. If one of the fragments is cut off from the WINS server, it will only + be able to access servers on its local subnet, by using subnet-isolated + broadcast NetBIOS name resolution. The effects are similar to that of + losing access to a DNS server. +

    11.5.3.5. Start up the winbindd daemon and test it!

    15.5. Setting up a WINS server

    Eventually, you will want to modify your smb startup script to -automatically invoke the winbindd daemon when the other parts of -SAMBA start, but it is possible to test out just the winbind -portion first. To start up winbind services, enter the following -command as root:

    Either a Samba machine or a Windows NT Server machine may be set up +as a WINS server. To set a Samba machine to be a WINS server you must +add the following option to the smb.conf file on the selected machine : +in the [globals] section add the line

    root# /usr/local/samba/bin/winbindd wins support = yes

    I'm always paranoid and like to make sure the daemon -is really running...

    Versions of Samba previous to 1.9.17 had this parameter default to +yes. If you have any older versions of Samba on your network it is +strongly suggested you upgrade to 1.9.17 or above, or at the very +least set the parameter to 'no' on all these machines.

    root# Machines with "ps -ae | grep winbinddwins support = yes" will keep a list of +all NetBIOS names registered with them, acting as a DNS for NetBIOS names.

    You should set up only ONE wins server. Do NOT set the +"wins support = yes" option on more than one Samba +server.

    To set up a Windows NT Server as a WINS server you need to set up +the WINS service - see your NT documentation for details. Note that +Windows NT WINS Servers can replicate to each other, allowing more +than one to be set up in a complex subnet environment. As Microsoft +refuse to document these replication protocols Samba cannot currently +participate in these replications. It is possible in the future that +a Samba->Samba WINS replication protocol may be defined, in which +case more than one Samba machine could be set up as a WINS server +but currently only one Samba server should have the "wins support = yes" +parameter set.

    After the WINS server has been configured you must ensure that all +machines participating on the network are configured with the address +of this WINS server. If your WINS server is a Samba machine, fill in +the Samba machine IP address in the "Primary WINS Server" field of +the "Control Panel->Network->Protocols->TCP->WINS Server" dialogs +in Windows 95 or Windows NT. To tell a Samba server the IP address +of the WINS server add the following line to the [global] section of +all smb.conf files :

    wins server = >name or IP address<

    This command should produce output like this, if the daemon is running

    where >name or IP address< is either the DNS name of the WINS server +machine or its IP address.

    3025 ? 00:00:00 winbindd

    Note that this line MUST NOT BE SET in the smb.conf file of the Samba +server acting as the WINS server itself. If you set both the +"wins support = yes" option and the +"wins server = >name<" option then +nmbd will fail to start.

    There are two possible scenarios for setting up cross subnet browsing. +The first details setting up cross subnet browsing on a network containing +Windows 95, Samba and Windows NT machines that are not configured as +part of a Windows NT Domain. The second details setting up cross subnet +browsing on networks that contain NT Domains.

    15.6. Setting up Browsing in a WORKGROUP

    Now... for the real test, try to get some information about the -users on your PDC

    To set up cross subnet browsing on a network containing machines +in up to be in a WORKGROUP, not an NT Domain you need to set up one +Samba server to be the Domain Master Browser (note that this is *NOT* +the same as a Primary Domain Controller, although in an NT Domain the +same machine plays both roles). The role of a Domain master browser is +to collate the browse lists from local master browsers on all the +subnets that have a machine participating in the workgroup. Without +one machine configured as a domain master browser each subnet would +be an isolated workgroup, unable to see any machines on any other +subnet. It is the presense of a domain master browser that makes +cross subnet browsing possible for a workgroup.

    In an WORKGROUP environment the domain master browser must be a +Samba server, and there must only be one domain master browser per +workgroup name. To set up a Samba server as a domain master browser, +set the following option in the [global] section of the smb.conf file :

    root# /usr/local/samba/bin/wbinfo -u domain master = yes

    -This should echo back a list of users on your Windows users on -your PDC. For example, I get the following response:

    The domain master browser should also preferrably be the local master +browser for its own subnet. In order to achieve this set the following +options in the [global] section of the smb.conf file :

    CEO+Administrator
-CEO+burdell
-CEO+Guest
-CEO+jt-ad
-CEO+krbtgt
-CEO+TsInternetUser
    domain master = yes + local master = yes + preferred master = yes + os level = 65

    Obviously, I have named my domain 'CEO' and my winbind -separator is '+'.

    The domain master browser may be the same machine as the WINS +server, if you require.

    You can do the same sort of thing to get group information from -the PDC:

    Next, you should ensure that each of the subnets contains a +machine that can act as a local master browser for the +workgroup. Any NT machine should be able to do this, as will +Windows 95 machines (although these tend to get rebooted more +often, so it's not such a good idea to use these). To make a +Samba server a local master browser set the following +options in the [global] section of the smb.conf file :

    root# /usr/local/samba/bin/wbinfo -g
-CEO+Domain Admins
-CEO+Domain Users
-CEO+Domain Guests
-CEO+Domain Computers
-CEO+Domain Controllers
-CEO+Cert Publishers
-CEO+Schema Admins
-CEO+Enterprise Admins
-CEO+Group Policy Creator Owners
    domain master = no + local master = yes + preferred master = yes + os level = 65

    The function 'getent' can now be used to get unified -lists of both local and PDC users and groups. -Try the following command:

    root# getent passwd

    You should get a list that looks like your /etc/passwd -list followed by the domain users with their new uids, gids, home -directories and default shells.

    The same thing can be done for groups with the command

    Do not do this for more than one Samba server on each subnet, +or they will war with each other over which is to be the local +master browser.

    root# getent group

    11.5.3.6. Fix the /etc/rc.d/init.d/smb startup files

    The "local master" parameter allows Samba to act as a local master +browser. The "preferred master" causes nmbd to force a browser +election on startup and the "os level" parameter sets Samba high +enough so that it should win any browser elections.

    The winbindd daemon needs to start up after the -smbd and nmbd daemons are running. -To accomplish this task, you need to modify the /etc/init.d/smb -script to add commands to invoke this daemon in the proper sequence. My -/etc/init.d/smb file starts up smbd, -nmbd, and winbindd from the -/usr/local/samba/bin directory directly. The 'start' -function in the script looks like this:

    If you have an NT machine on the subnet that you wish to +be the local master browser then you can disable Samba from +becoming a local master browser by setting the following +options in the [global] section of the smb.conf file :

    start() {
-        KIND="SMB"
-        echo -n $"Starting $KIND services: "
-        daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
-        RETVAL=$?
-        echo
-        KIND="NMB"
-        echo -n $"Starting $KIND services: "
-        daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
-        RETVAL2=$?
-        echo
-        KIND="Winbind"
-        echo -n $"Starting $KIND services: "
-        daemon /usr/local/samba/bin/winbindd
-        RETVAL3=$?
-        echo
-        [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && touch /var/lock/subsys/smb || \
-           RETVAL=1
-        return $RETVAL
-}
    domain master = no + local master = no + preferred master = no + os level = 0

    15.7. Setting up Browsing in a DOMAIN

    The 'stop' function has a corresponding entry to shut down the -services and look s like this:

    If you are adding Samba servers to a Windows NT Domain then +you must not set up a Samba server as a domain master browser. +By default, a Windows NT Primary Domain Controller for a Domain +name is also the Domain master browser for that name, and many +things will break if a Samba server registers the Domain master +browser NetBIOS name (DOMAIN>1B<) with WINS instead of the PDC.

    For subnets other than the one containing the Windows NT PDC +you may set up Samba servers as local master browsers as +described. To make a Samba server a local master browser set +the following options in the [global] section of the smb.conf +file :

    stop() {
-        KIND="SMB"
-        echo -n $"Shutting down $KIND services: "
-        killproc smbd
-        RETVAL=$?
-        echo
-        KIND="NMB"
-        echo -n $"Shutting down $KIND services: "
-        killproc nmbd
-        RETVAL2=$?
-        echo
-        KIND="Winbind"
-        echo -n $"Shutting down $KIND services: "
-        killproc winbindd
-        RETVAL3=$?
-        [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && rm -f /var/lock/subsys/smb
-        echo ""
-        return $RETVAL
-}
    domain master = no + local master = yes + preferred master = yes + os level = 65

    If you restart the smbd, nmbd, -and If you wish to have a Samba server fight the election with machines +on the same subnet you may set the "os level" parameter to lower +levels. By doing this you can tune the order of machines that +will become local master browsers if they are running. For +more details on this see the section "FORCING SAMBA TO BE THE MASTER" +below.

    If you have Windows NT machines that are members of the domain +on all subnets, and you are sure they will always be running then +you can disable Samba from taking part in browser elections and +ever becoming a local master browser by setting following options +in the [global] section of the smb.conf file :

    winbindd daemons at this point, you -should be able to connect to the samba server as a domain member just as -if you were a local user.

    domain master = no + local master = no + preferred master = no + os level = 0

    15.8. Forcing samba to be the master

    Who becomes the "master browser" is determined by an election process +using broadcasts. Each election packet contains a number of parameters +which determine what precedence (bias) a host should have in the +election. By default Samba uses a very low precedence and thus loses +elections to just about anyone else.

    If you want Samba to win elections then just set the "os level" global +option in smb.conf to a higher number. It defaults to 0. Using 34 +would make it win all elections over every other system (except other +samba systems!)

    A "os level" of 2 would make it beat WfWg and Win95, but not NTAS. A +NTAS domain controller uses level 32.

    The maximum os level is 255

    If you want samba to force an election on startup, then set the +"preferred master" global option in smb.conf to "yes". Samba will +then have a slight advantage over other potential master browsers +that are not preferred master browsers. Use this parameter with +care, as if you have two hosts (whether they are windows 95 or NT or +samba) on the same local subnet both set with "preferred master" to +"yes", then periodically and continually they will force an election +in order to become the local master browser.

    If you want samba to be a "domain master browser", then it is +recommended that you also set "preferred master" to "yes", because +samba will not become a domain master browser for the whole of your +LAN or WAN if it is not also a local master browser on its own +broadcast isolated subnet.

    It is possible to configure two samba servers to attempt to become +the domain master browser for a domain. The first server that comes +up will be the domain master browser. All other samba servers will +attempt to become the domain master browser every 5 minutes. They +will find that another samba server is already the domain master +browser and will fail. This provides automatic redundancy, should +the current domain master browser fail.

    15.9. Making samba the domain master

    The domain master is responsible for collating the browse lists of +multiple subnets so that browsing can occur between subnets. You can +make samba act as the domain master by setting "domain master = yes" +in smb.conf. By default it will not be a domain master.

    Note that you should NOT set Samba to be the domain master for a +workgroup that has the same name as an NT Domain.

    When samba is the domain master and the master browser it will listen +for master announcements (made roughly every twelve minutes) from local +master browsers on other subnets and then contact them to synchronise +browse lists.

    If you want samba to be the domain master then I suggest you also set +the "os level" high enough to make sure it wins elections, and set +"preferred master" to "yes", to get samba to force an election on +startup.

    Note that all your servers (including samba) and clients should be +using a WINS server to resolve NetBIOS names. If your clients are only +using broadcasting to resolve NetBIOS names, then two things will occur:

    1. your local master browsers will be unable to find a domain master + browser, as it will only be looking on the local subnet. +

    2. if a client happens to get hold of a domain-wide browse list, and + a user attempts to access a host in that list, it will be unable to + resolve the NetBIOS name of that host. +

    If, however, both samba and your clients are using a WINS server, then:

    1. your local master browsers will contact the WINS server and, as long as + samba has registered that it is a domain master browser with the WINS + server, your local master browser will receive samba's ip address + as its domain master browser. +

    2. when a client receives a domain-wide browse list, and a user attempts + to access a host in that list, it will contact the WINS server to + resolve the NetBIOS name of that host. as long as that host has + registered its NetBIOS name with the same WINS server, the user will + be able to see that host. +

    15.10. Note about broadcast addresses

    If your network uses a "0" based broadcast address (for example if it +ends in a 0) then you will strike problems. Windows for Workgroups +does not seem to support a 0's broadcast and you will probably find +that browsing and name lookups won't work.

    15.11. Multiple interfaces

    Samba now supports machines with multiple network interfaces. If you +have multiple interfaces then you will need to use the "interfaces" +option in smb.conf to configure them. See smb.conf(5) for details.

    Chapter 16. Samba performance issues

    16.1. Comparisons

    The Samba server uses TCP to talk to the client. Thus if you are +trying to see if it performs well you should really compare it to +programs that use the same protocol. The most readily available +programs for file transfer that use TCP are ftp or another TCP based +SMB server.

    If you want to test against something like a NT or WfWg server then +you will have to disable all but TCP on either the client or +server. Otherwise you may well be using a totally different protocol +(such as Netbeui) and comparisons may not be valid.

    Generally you should find that Samba performs similarly to ftp at raw +transfer speed. It should perform quite a bit faster than NFS, +although this very much depends on your system.

    Several people have done comparisons between Samba and Novell, NFS or +WinNT. In some cases Samba performed the best, in others the worst. I +suspect the biggest factor is not Samba vs some other system but the +hardware and drivers used on the various systems. Given similar +hardware Samba should certainly be competitive in speed with other +systems.

    11.5.3.7. Configure Winbind and PAM

    16.2. Oplocks

    16.2.1. Overview

    If you have made it this far, you know that winbindd and samba are working -together. If you want to use winbind to provide authentication for other -services, keep reading. The pam configuration files need to be altered in -this step. (Did you remember to make backups of your original -/etc/pam.d files? If not, do it now.)

    Oplocks are the way that SMB clients get permission from a server to +locally cache file operations. If a server grants an oplock +(opportunistic lock) then the client is free to assume that it is the +only one accessing the file and it will agressively cache file +data. With some oplock types the client may even cache file open/close +operations. This can give enormous performance benefits.

    You will need a pam module to use winbindd with these other services. This -module will be compiled in the ../source/nsswitch directory -by invoking the command

    With the release of Samba 1.9.18 we now correctly support opportunistic +locks. This is turned on by default, and can be turned off on a share- +by-share basis by setting the parameter :

    root# make nsswitch/pam_winbind.sooplocks = False

    from the ../source directory. The -pam_winbind.so file should be copied to the location of -your other pam security modules. On my RedHat system, this was the -/lib/security directory.

    We recommend that you leave oplocks on however, as current benchmark +tests with NetBench seem to give approximately a 30% improvement in +speed with them on. This is on average however, and the actual +improvement seen can be orders of magnitude greater, depending on +what the client redirector is doing.

    root# Previous to Samba 1.9.18 there was a 'fake oplocks' option. This +option has been left in the code for backwards compatibility reasons +but it's use is now deprecated. A short summary of what the old +code did follows.

    16.2.2. Level2 Oplocks

    With Samba 2.0.5 a new capability - level2 (read only) oplocks is +supported (although the option is off by default - see the smb.conf +man page for details). Turning on level2 oplocks (on a share-by-share basis) +by setting the parameter :

    cp ../samba/source/nsswitch/pam_winbind.so /lib/securitylevel2 oplocks = true

    The /etc/pam.d/samba file does not need to be changed. I -just left this fileas it was:

    should speed concurrent access to files that are not commonly written +to, such as application serving shares (ie. shares that contain common +.EXE files - such as a Microsoft Office share) as it allows clients to +read-ahread cache copies of these files.

    16.2.3. Old 'fake oplocks' option - deprecated

    auth    required        /lib/security/pam_stack.so service=system-auth
-account required        /lib/security/pam_stack.so service=system-auth

    Samba can also fake oplocks, by granting a oplock whenever a client +asks for one. This is controlled using the smb.conf option "fake +oplocks". If you set "fake oplocks = yes" then you are telling the +client that it may agressively cache the file data for all opens.

    The other services that I modified to allow the use of winbind -as an authentication service were the normal login on the console (or a terminal -session), telnet logins, and ftp service. In order to enable these -services, you may first need to change the entries in -/etc/xinetd.d (or /etc/inetd.conf). -RedHat 7.1 uses the new xinetd.d structure, in this case you need -to change the lines in /etc/xinetd.d/telnet -and /etc/xinetd.d/wu-ftp from

    Enabling 'fake oplocks' on all read-only shares or shares that you know +will only be accessed from one client at a time you will see a big +performance improvement on many operations. If you enable this option +on shares where multiple clients may be accessing the files read-write +at the same time you can get data corruption.

    16.3. Socket options

    enable = no

    There are a number of socket options that can greatly affect the +performance of a TCP based server like Samba.

    to

    The socket options that Samba uses are settable both on the command +line with the -O option, or in the smb.conf file.

    enable = yes

    The "socket options" section of the smb.conf manual page describes how +to set these and gives recommendations.

    -For ftp services to work properly, you will also need to either -have individual directories for the domain users already present on -the server, or change the home directory template to a general -directory for all domain users. These can be easily set using -the smb.conf global entry -template homedir.

    Getting the socket options right can make a big difference to your +performance, but getting them wrong can degrade it by just as +much. The correct settings are very dependent on your local network.

    The /etc/pam.d/ftp file can be changed -to allow winbind ftp access in a manner similar to the -samba file. My /etc/pam.d/ftp file was -changed to look like this:

    The socket option TCP_NODELAY is the one that seems to make the +biggest single difference for most networks. Many people report that +adding "socket options = TCP_NODELAY" doubles the read performance of +a Samba drive. The best explanation I have seen for this is that the +Microsoft TCP/IP stack is slow in sending tcp ACKs.

    16.4. Read size

    The option "read size" affects the overlap of disk reads/writes with +network reads/writes. If the amount of data being transferred in +several of the SMB commands (currently SMBwrite, SMBwriteX and +SMBreadbraw) is larger than this value then the server begins writing +the data before it has received the whole packet from the network, or +in the case of SMBreadbraw, it begins writing to the network before +all the data has been read from disk.

    This overlapping works best when the speeds of disk and network access +are similar, having very little effect when the speed of one is much +greater than the other.

    The default value is 16384, but very little experimentation has been +done yet to determine the optimal value, and it is likely that the best +value will vary greatly between systems anyway. A value over 65536 is +pointless and will cause you to allocate memory unnecessarily.

    16.5. Max xmit

    At startup the client and server negotiate a "maximum transmit" size, +which limits the size of nearly all SMB commands. You can set the +maximum size that Samba will negotiate using the "max xmit = " option +in smb.conf. Note that this is the maximum size of SMB request that +Samba will accept, but not the maximum size that the *client* will accept. +The client maximum receive size is sent to Samba by the client and Samba +honours this limit.

    It defaults to 65536 bytes (the maximum), but it is possible that some +clients may perform better with a smaller transmit unit. Trying values +of less than 2048 is likely to cause severe problems.

    In most cases the default is the best option.

    16.6. Locking

    By default Samba does not implement strict locking on each read/write +call (although it did in previous versions). If you enable strict +locking (using "strict locking = yes") then you may find that you +suffer a severe performance hit on some systems.

    The performance hit will probably be greater on NFS mounted +filesystems, but could be quite high even on local disks.

    16.7. Share modes

    Some people find that opening files is very slow. This is often +because of the "share modes" code needed to fully implement the dos +share modes stuff. You can disable this code using "share modes = +no". This will gain you a lot in opening and closing files but will +mean that (in some cases) the system won't force a second user of a +file to open the file read-only if the first has it open +read-write. For many applications that do their own locking this +doesn't matter, but for some it may. Most Windows applications +depend heavily on "share modes" working correctly and it is +recommended that the Samba share mode support be left at the +default of "on".

    The share mode code in Samba has been re-written in the 1.9.17 +release following tests with the Ziff-Davis NetBench PC Benchmarking +tool. It is now believed that Samba 1.9.17 implements share modes +similarly to Windows NT.

    NOTE: In the most recent versions of Samba there is an option to use +shared memory via mmap() to implement the share modes. This makes +things much faster. See the Makefile for how to enable this.

    16.8. Log level

    If you set the log level (also known as "debug level") higher than 2 +then you may suffer a large drop in performance. This is because the +server flushes the log file after each operation, which can be very +expensive.

    16.9. Wide lines

    The "wide links" option is now enabled by default, but if you disable +it (for better security) then you may suffer a performance hit in +resolving filenames. The performance loss is lessened if you have +"getwd cache = yes", which is now the default.

    16.10. Read raw

    The "read raw" operation is designed to be an optimised, low-latency +file read operation. A server may choose to not support it, +however. and Samba makes support for "read raw" optional, with it +being enabled by default.

    In some cases clients don't handle "read raw" very well and actually +get lower performance using it than they get using the conventional +read operations.

    So you might like to try "read raw = no" and see what happens on your +network. It might lower, raise or not affect your performance. Only +testing can really tell.

    16.11. Write raw

    The "write raw" operation is designed to be an optimised, low-latency +file write operation. A server may choose to not support it, +however. and Samba makes support for "write raw" optional, with it +being enabled by default.

    Some machines may find "write raw" slower than normal write, in which +case you may wish to change this option.

    16.12. Read prediction

    auth       required     /lib/security/pam_listfile.so item=user sense=deny file=/etc/ftpusers onerr=succeed
-auth       sufficient   /lib/security/pam_winbind.so
-auth       required     /lib/security/pam_stack.so service=system-auth
-auth       required     /lib/security/pam_shells.so
-account    sufficient   /lib/security/pam_winbind.so
-account    required     /lib/security/pam_stack.so service=system-auth
-session    required     /lib/security/pam_stack.so service=system-auth

    Samba can do read prediction on some of the SMB commands. Read +prediction means that Samba reads some extra data on the last file it +read while waiting for the next SMB command to arrive. It can then +respond more quickly when the next read request arrives.

    The /etc/pam.d/login file can be changed nearly the -same way. It now looks like this:

    This is disabled by default. You can enable it by using "read +prediction = yes".

    auth       required     /lib/security/pam_securetty.so
-auth       sufficient   /lib/security/pam_winbind.so
-auth       sufficient   /lib/security/pam_unix.so use_first_pass
-auth       required     /lib/security/pam_stack.so service=system-auth
-auth       required     /lib/security/pam_nologin.so
-account    sufficient   /lib/security/pam_winbind.so
-account    required     /lib/security/pam_stack.so service=system-auth
-password   required     /lib/security/pam_stack.so service=system-auth
-session    required     /lib/security/pam_stack.so service=system-auth
-session    optional     /lib/security/pam_console.so

    Note that read prediction is only used on files that were opened read +only.

    In this case, I added the auth sufficient /lib/security/pam_winbind.so -lines as before, but also added the required pam_securetty.so -above it, to disallow root logins over the network. I also added a -sufficient /lib/security/pam_unix.so use_first_pass -line after the winbind.so line to get rid of annoying -double prompts for passwords.

    Read prediction should particularly help for those silly clients (such +as "Write" under NT) which do lots of very small reads on a file.

    Samba will not read ahead more data than the amount specified in the +"read size" option. It always reads ahead on 1k block boundaries.

    16.13. Memory mapping

    Samba supports reading files via memory mapping them. One some +machines this can give a large boost to performance, on others it +makes not difference at all, and on some it may reduce performance.

    To enable you you have to recompile Samba with the -DUSE_MMAP option +on the FLAGS line of the Makefile.

    Note that memory mapping is only used on files opened read only, and +is not used by the "read raw" operation. Thus you may find memory +mapping is more effective if you disable "read raw" using "read raw = +no".

    16.14. Slow Clients

    One person has reported that setting the protocol to COREPLUS rather +than LANMAN2 gave a dramatic speed improvement (from 10k/s to 150k/s).

    I suspect that his PC's (386sx16 based) were asking for more data than +they could chew. I suspect a similar speed could be had by setting +"read raw = no" and "max xmit = 2048", instead of changing the +protocol. Lowering the "read size" might also help.

    16.15. Slow Logins

    Slow logins are almost always due to the password checking time. Using +the lowest practical "password level" will improve things a lot. You +could also enable the "UFC crypt" option in the Makefile.

    11.6. Limitations16.16. Client tuning

    Winbind has a number of limitations in its current - released version that we hope to overcome in future - releases:

    Often a speed problem can be traced to the client. The client (for +example Windows for Workgroups) can often be tuned for better TCP +performance.

    See your client docs for details. In particular, I have heard rumours +that the WfWg options TCPWINDOWSIZE and TCPSEGMENTSIZE can have a +large impact on performance.

    Also note that some people have found that setting DefaultRcvWindow in +the [MSTCP] section of the SYSTEM.INI file under WfWg to 3072 gives a +big improvement. I don't know why.

    My own experience wth DefaultRcvWindow is that I get much better +performance with a large value (16384 or larger). Other people have +reported that anything over 3072 slows things down enourmously. One +person even reported a speed drop of a factor of 30 when he went from +3072 to 8192. I don't know why.

    It probably depends a lot on your hardware, and the type of unix box +you have at the other end of the link.

    Paul Cochrane has done some testing on client side tuning and come +to the following conclusions:

    Install the W2setup.exe file from www.microsoft.com. This is an +update for the winsock stack and utilities which improve performance.

    Configure the win95 TCPIP registry settings to give better +perfomance. I use a program called MTUSPEED.exe which I got off the +net. There are various other utilities of this type freely available. +The setting which give the best performance for me are:

      1. Winbind is currently only available for - the Linux operating system, although ports to other operating - systems are certainly possible. For such ports to be feasible, - we require the C library of the target operating system to - support the Name Service Switch and Pluggable Authentication - Modules systems. This is becoming more common as NSS and - PAM gain support among UNIX vendors.

        MaxMTU Remove

      2. The mappings of Windows NT RIDs to UNIX ids - is not made algorithmically and depends on the order in which - unmapped users or groups are seen by winbind. It may be difficult - to recover the mappings of rid to UNIX id mapping if the file - containing this information is corrupted or destroyed.

        RWIN Remove

      3. Currently the winbind PAM module does not take - into account possible workstation and logon time restrictions - that may be been set for Windows NT users.

        MTUAutoDiscover Disable

  • MTUBlackHoleDetect Disable

  • Time To Live Enabled

  • Time To Live - HOPS 32

  • NDI Cache Size 0

    • I tried virtually all of the items mentioned in the document and +the only one which made a difference to me was the socket options. It +turned out I was better off without any!!!!!

    In terms of overall speed of transfer, between various win95 clients +and a DX2-66 20MB server with a crappy NE2000 compatible and old IDE +drive (Kernel 2.0.30). The transfer rate was reasonable for 10 baseT.

    FIXME +The figures are: Put Get +P166 client 3Com card: 420-440kB/s 500-520kB/s +P100 client 3Com card: 390-410kB/s 490-510kB/s +DX4-75 client NE2000: 370-380kB/s 330-350kB/s

    I based these test on transfer two files a 4.5MB text file and a 15MB +textfile. The results arn't bad considering the hardware Samba is +running on. It's a crap machine!!!!

    The updates mentioned in 1 and 2 brought up the transfer rates from +just over 100kB/s in some clients.

    A new client is a P333 connected via a 100MB/s card and hub. The +transfer rates from this were good: 450-500kB/s on put and 600+kB/s +on get.

    Looking at standard FTP throughput, Samba is a bit slower (100kB/s +upwards). I suppose there is more going on in the samba protocol, but +if it could get up to the rate of FTP the perfomance would be quite +staggering.

    11.7. Conclusion16.17. My Results

    The winbind system, through the use of the Name Service - Switch, Pluggable Authentication Modules, and appropriate - Microsoft RPC calls have allowed us to provide seamless - integration of Microsoft Windows NT domain users on a - UNIX system. The result is a great reduction in the administrative - cost of running a mixed UNIX and NT network.

    Some people want to see real numbers in a document like this, so here +they are. I have a 486sx33 client running WfWg 3.11 with the 3.11b +tcp/ip stack. It has a slow IDE drive and 20Mb of ram. It has a SMC +Elite-16 ISA bus ethernet card. The only WfWg tuning I've done is to +set DefaultRcvWindow in the [MSTCP] section of system.ini to 16384. My +server is a 486dx3-66 running Linux. It also has 20Mb of ram and a SMC +Elite-16 card. You can see my server config in the examples/tridge/ +subdirectory of the distribution.

    I get 490k/s on reading a 8Mb file with copy. +I get 441k/s writing the same file to the samba server.

    Of course, there's a lot more to benchmarks than 2 raw throughput +figures, but it gives you a ballpark figure.

    I've also tested Win95 and WinNT, and found WinNT gave me the best +speed as a samba client. The fastest client of all (for me) is +smbclient running on another linux box. Maybe I'll add those results +here someday ...

    Chapter 12. OS2 Client HOWTOChapter 17. OS2 Client HOWTO

    12.1. FAQs17.1. FAQs

    12.1.1. How can I configure OS/2 Warp Connect or +NAME="AEN2862" +>17.1.1. How can I configure OS/2 Warp Connect or OS/2 Warp 4 as a client for Samba?

    12.1.2. How can I configure OS/2 Warp 3 (not Connect), +NAME="AEN2877" +>17.1.2. How can I configure OS/2 Warp 3 (not Connect), OS/2 1.2, 1.3 or 2.x for Samba?

    12.1.3. Are there any other issues when OS/2 (any version) +NAME="AEN2886" +>17.1.3. Are there any other issues when OS/2 (any version) is used as a client?

    12.1.4. How do I get printer driver download working +NAME="AEN2890" +>17.1.4. How do I get printer driver download working for OS/2 clients?

    Chapter 13. HOWTO Access Samba source code via CVSChapter 18. HOWTO Access Samba source code via CVS

    13.1. Introduction18.1. Introduction

    Samba is developed in an open environment. Developers use CVS @@ -10775,8 +13894,8 @@ CLASS="SECT1" >

    13.2. CVS Access to samba.org18.2. CVS Access to samba.org

    The machine samba.org runs a publicly accessible CVS @@ -10788,8 +13907,8 @@ CLASS="SECT2" >

    13.2.1. Access via CVSweb18.2.1. Access via CVSweb

    You can access the source code via your @@ -10809,8 +13928,8 @@ CLASS="SECT2" >

    13.2.2. Access via cvs18.2.2. Access via cvs

    You can also access the source code via a @@ -10913,16 +14032,242 @@ CLASS="COMMAND" >

    Chapter 19. Reporting Bugs

    19.1. Introduction

    The email address for bug reports is samba@samba.org

    Please take the time to read this file before you submit a bug +report. Also, please see if it has changed between releases, as we +may be changing the bug reporting mechanism at some time.

    Please also do as much as you can yourself to help track down the +bug. Samba is maintained by a dedicated group of people who volunteer +their time, skills and efforts. We receive far more mail about it than +we can possibly answer, so you have a much higher chance of an answer +and a fix if you send us a "developer friendly" bug report that lets +us fix it fast.

    Do not assume that if you post the bug to the comp.protocols.smb +newsgroup or the mailing list that we will read it. If you suspect that your +problem is not a bug but a configuration problem then it is better to send +it to the Samba mailing list, as there are (at last count) 5000 other users on +that list that may be able to help you.

    You may also like to look though the recent mailing list archives, +which are conveniently accessible on the Samba web pages +at http://samba.org/samba/

    19.2. General info

    Before submitting a bug report check your config for silly +errors. Look in your log files for obvious messages that tell you that +you've misconfigured something and run testparm to test your config +file for correct syntax.

    Have you run through the diagnosis? +This is very important.

    If you include part of a log file with your bug report then be sure to +annotate it with exactly what you were doing on the client at the +time, and exactly what the results were.

    19.3. Debug levels

    If the bug has anything to do with Samba behaving incorrectly as a +server (like refusing to open a file) then the log files will probably +be very useful. Depending on the problem a log level of between 3 and +10 showing the problem may be appropriate. A higher level givesmore +detail, but may use too much disk space.

    To set the debug level use log level = in your +smb.conf. You may also find it useful to set the log +level higher for just one machine and keep separate logs for each machine. +To do this use:

    log level = 10
+log file = /usr/local/samba/lib/log.%m
+include = /usr/local/samba/lib/smb.conf.%m

    then create a file +/usr/local/samba/lib/smb.conf.machine where +"machine" is the name of the client you wish to debug. In that file +put any smb.conf commands you want, for example +log level= may be useful. This also allows you to +experiment with different security systems, protocol levels etc on just +one machine.

    The smb.conf entry log level = +is synonymous with the entry debuglevel = that has been +used in older versions of Samba and is being retained for backwards +compatibility of smb.conf files.

    As the log level = value is increased you will record +a significantly increasing level of debugging information. For most +debugging operations you may not need a setting higher than 3. Nearly +all bugs can be tracked at a setting of 10, but be prepared for a VERY +large volume of log data.

    19.4. Internal errors

    If you get a "INTERNAL ERROR" message in your log files it means that +Samba got an unexpected signal while running. It is probably a +segmentation fault and almost certainly means a bug in Samba (unless +you have faulty hardware or system software)

    If the message came from smbd then it will probably be accompanied by +a message which details the last SMB message received by smbd. This +info is often very useful in tracking down the problem so please +include it in your bug report.

    You should also detail how to reproduce the problem, if +possible. Please make this reasonably detailed.

    You may also find that a core file appeared in a "corefiles" +subdirectory of the directory where you keep your samba log +files. This file is the most useful tool for tracking down the bug. To +use it you do this:

    gdb smbd core

    adding appropriate paths to smbd and core so gdb can find them. If you +don't have gdb then try "dbx". Then within the debugger use the +command "where" to give a stack trace of where the problem +occurred. Include this in your mail.

    If you known any assembly language then do a "disass" of the routine +where the problem occurred (if its in a library routine then +disassemble the routine that called it) and try to work out exactly +where the problem is by looking at the surrounding code. Even if you +don't know assembly then incuding this info in the bug report can be +useful.

    19.5. Attaching to a running process

    Unfortunately some unixes (in particular some recent linux kernels) +refuse to dump a core file if the task has changed uid (which smbd +does often). To debug with this sort of system you could try to attach +to the running process using "gdb smbd PID" where you get PID from +smbstatus. Then use "c" to continue and try to cause the core dump +using the client. The debugger should catch the fault and tell you +where it occurred.

    19.6. Patches

    The best sort of bug report is one that includes a fix! If you send us +patches please use diff -u format if your version of +diff supports it, otherwise use diff -c4. Make sure +your do the diff against a clean version of the source and let me know +exactly what version you used.

    Index

    Primary Domain Controller, Background