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| author | Gerald W. Carter <jerry@samba.org> | 2008-04-22 10:09:40 -0500 |
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| committer | Gerald W. Carter <jerry@samba.org> | 2008-04-23 08:47:48 -0500 |
| commit | 8f8a9f01909ba29e2b781310baeeaaddc3f15f0d (patch) | |
| tree | 90c6b720ad3a7bc815245c0ef28820424f89d658 /docs-xml/Samba3-ByExample/SBE-AddingUNIXClients.xml | |
| parent | 197238246389c40edc60c6630d18d6913086e630 (diff) | |
| download | samba-8f8a9f01909ba29e2b781310baeeaaddc3f15f0d.tar.gz samba-8f8a9f01909ba29e2b781310baeeaaddc3f15f0d.tar.bz2 samba-8f8a9f01909ba29e2b781310baeeaaddc3f15f0d.zip | |
Moving docs tree to docs-xml to make room for generated docs in the release tarball.
(This used to be commit 9f672c26d63955f613088489c6efbdc08b5b2d14)
Diffstat (limited to 'docs-xml/Samba3-ByExample/SBE-AddingUNIXClients.xml')
| -rw-r--r-- | docs-xml/Samba3-ByExample/SBE-AddingUNIXClients.xml | 2870 |
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diff --git a/docs-xml/Samba3-ByExample/SBE-AddingUNIXClients.xml b/docs-xml/Samba3-ByExample/SBE-AddingUNIXClients.xml new file mode 100644 index 0000000000..a20703af39 --- /dev/null +++ b/docs-xml/Samba3-ByExample/SBE-AddingUNIXClients.xml @@ -0,0 +1,2870 @@ +<?xml version="1.0" encoding="iso-8859-1"?> +<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc"> +<chapter id="unixclients"> + <title>Adding Domain Member Servers and Clients</title> + + <para><indexterm> + <primary>Open Magazine</primary> + </indexterm><indexterm> + <primary>survey</primary> + </indexterm> + The most frequently discussed Samba subjects over the past 2 years have focused around domain control and printing. + It is well known that Samba is a file and print server. A recent survey conducted by <emphasis>Open Magazine</emphasis> found + that of all respondents, 97 percent use Samba for file and print services, and 68 percent use Samba for Domain Control. See the + <ulink url="http://www.open-mag.com/cgi-bin/opencgi/surveys/survey.cgi?survey_name=samba">Open-Mag</ulink> + Web site for current information. The survey results as found on January 14, 2004, are shown in + <link linkend="ch09openmag"/>. + </para> + + <figure id="ch09openmag"> + <title>Open Magazine Samba Survey</title> + <imagefile scale="60">openmag</imagefile> + </figure> + + <para> + While domain control is an exciting subject, basic file and print sharing remains the staple bread-and-butter + function that Samba provides. Yet this book may give the appearance of having focused too much on more + exciting aspects of Samba deployment. This chapter directs your attention to provide important information on + the addition of Samba servers into your present Windows network &smbmdash; whatever the controlling technology + may be. So let's get back to our good friends at Abmas. + </para> + +<sect1> + <title>Introduction</title> + + <para><indexterm> + <primary>Linux desktop</primary> + </indexterm><indexterm> + <primary>Domain Member</primary> + <secondary>server</secondary> + </indexterm> + Looking back over the achievements of the past year or two, daily events at Abmas are rather straightforward + with not too many distractions or problems. Your team is doing well, but a number of employees + are asking for Linux desktop systems. Your network has grown and demands additional domain member servers. Let's + get on with this; Christine and Stan are ready to go. + </para> + + <para><indexterm> + <primary>Domain Member</primary> + <secondary>desktop</secondary> + </indexterm> + Stan is firmly in control of the department of the future, while Christine is enjoying a stable and + predictable network environment. It is time to add more servers and to add Linux desktops. It is + time to meet the demands of future growth and endure trial by fire. + </para> + + <sect2> + <title>Assignment Tasks</title> + + <para><indexterm> + <primary>Active Directory</primary> + </indexterm> + You must now add UNIX/Linux domain member servers to your network. You have a friend who has a Windows 2003 + Active Directory domain network who wants to add a Samba/Linux server and has asked Christine to help him + out. Your real objective is to help Christine to see more of the way the Microsoft world lives and use + her help to get validation that Samba really does live up to expectations. + </para> + + <para> + Over the past 6 months, you have hired several new staff who want Linux on their desktops. You must integrate + these systems to make sure that Abmas is not building islands of technology. You ask Christine to + do likewise at Swodniw Biz NL (your friend's company) to help them to evaluate a Linux desktop. You want to make + the right decision, don't you? + </para> + + </sect2> +</sect1> + +<sect1> + <title>Dissection and Discussion</title> + + <para> + <indexterm><primary>winbind</primary></indexterm> + Recent Samba mailing-list activity is witness to how many sites are using winbind. Some have no trouble + at all with it, yet to others the problems seem insurmountable. Periodically there are complaints concerning + an inability to achieve identical user and group IDs between Windows and UNIX environments. + </para> + + <para> + You provide step-by-step implementations of the various tools that can be used for identity + resolution. You also provide working examples of solutions for integrated authentication for + both UNIX/Linux and Windows environments. + </para> + + <sect2> + <title>Technical Issues</title> + + <para> + One of the great challenges we face when people ask us, <quote>What is the best way to solve + this problem?</quote> is to get beyond the facts so we not only can clearly comprehend + the immediate technical problem, but also can understand how needs may change. + </para> + + <para> + <indexterm><primary>integrate</primary></indexterm> + There are a few facts we should note when dealing with the question of how best to + integrate UNIX/Linux clients and servers into a Windows networking environment: + </para> + + <itemizedlist> + <listitem><para> + <indexterm><primary>Domain Controller</primary></indexterm> + <indexterm><primary>authoritative</primary></indexterm> + <indexterm><primary>accounts</primary><secondary>authoritative</secondary></indexterm> + <indexterm><primary>PDC</primary></indexterm> + <indexterm><primary>BDC</primary></indexterm> + A domain controller (PDC or BDC) is always authoritative for all accounts in its domain. + This means that a BDC must (of necessity) be able to resolve all account UIDs and GIDs + to the same values that the PDC resolved them to. + </para></listitem> + + <listitem><para> + <indexterm><primary>local accounts</primary></indexterm> + <indexterm><primary>Domain Member</primary><secondary>authoritative</secondary><tertiary>local accounts</tertiary></indexterm> + <indexterm><primary>Domain accounts</primary></indexterm> + <indexterm><primary>winbindd</primary></indexterm> + A domain member can be authoritative for local accounts, but is never authoritative for + domain accounts. If a user is accessing a domain member server and that user's account + is not known locally, the domain member server must resolve the identity of that user + from the domain in which that user's account resides. It must then map that ID to a + UID/GID pair that it can use locally. This is handled by <command>winbindd</command>. + </para></listitem> + + <listitem><para> + Samba, when running on a domain member server, can resolve user identities from a + number of sources: + </para> + + <itemizedlist> + <listitem><para> + <indexterm><primary>getpwnam</primary></indexterm> + <indexterm><primary>getgrnam</primary></indexterm> + <indexterm><primary>NSS</primary></indexterm> + <indexterm><primary>LDAP</primary></indexterm> + <indexterm><primary>NIS</primary></indexterm> + By executing a system <command>getpwnam()</command> or <command>getgrnam()</command> call. + On systems that support it, this utilizes the name service switch (NSS) facility to + resolve names according to the configuration of the <filename>/etc/nsswitch.conf</filename> + file. NSS can be configured to use LDAP, winbind, NIS, or local files. + </para></listitem> + + <listitem><para> + <indexterm><primary>passdb backend</primary></indexterm> + <indexterm><primary>PADL</primary></indexterm> + <indexterm><primary>nss_ldap</primary></indexterm> + Performing, via NSS, a direct LDAP search (where an LDAP passdb backend has been configured). + This requires the use of the PADL nss_ldap tool (or equivalent). + </para></listitem> + + <listitem><para> + <indexterm><primary>winbindd</primary></indexterm> + <indexterm><primary>SID</primary></indexterm> + <indexterm><primary>winbindd_idmap.tdb</primary></indexterm> + <indexterm><primary>winbindd_cache.tdb</primary></indexterm> + Directly by querying <command>winbindd</command>. The <command>winbindd</command> + contacts a domain controller to attempt to resolve the identity of the user or group. It + receives the Windows networking security identifier (SID) for that appropriate + account and then allocates a local UID or GID from the range of available IDs and + creates an entry in its <filename>winbindd_idmap.tdb</filename> and + <filename>winbindd_cache.tdb</filename> files. + </para> + + <para> + <indexterm><primary>idmap backend</primary></indexterm> + <indexterm><primary>mapping</primary></indexterm> + If the parameter <smbconfoption name="idmap backend">ldap:ldap://myserver.domain</smbconfoption> + was specified and the LDAP server has been configured with a container in which it may + store the IDMAP entries, all domain members may share a common mapping. + </para></listitem> + </itemizedlist> + + <para> + Irrespective of how &smb.conf; is configured, winbind creates and caches a local copy of + the ID mapping database. It uses the <filename>winbindd_idmap.tdb</filename> and + <filename>winbindd_cache.tdb</filename> files to do this. + </para> + + <para> + Which of the resolver methods is chosen is determined by the way that Samba is configured + in the &smb.conf; file. Some of the configuration options are rather less than obvious to the + casual user. + </para></listitem> + + <listitem><para> + <indexterm><primary>winbind trusted domains only</primary></indexterm> + <indexterm><primary>domain member</primary><secondary>servers</secondary></indexterm> + <indexterm><primary>domain controllers</primary></indexterm> + If you wish to make use of accounts (users and/or groups) that are local to (i.e., capable + of being resolved using) the NSS facility, it is possible to use the + <smbconfoption name="winbind trusted domains only">Yes</smbconfoption> + in the &smb.conf; file. This parameter specifically applies to domain controllers, + and to domain member servers. + </para></listitem> + + </itemizedlist> + + <para> + <indexterm><primary>Posix accounts</primary></indexterm> + <indexterm><primary>Samba accounts</primary></indexterm> + <indexterm><primary>LDAP</primary></indexterm> + For many administrators, it should be plain that the use of an LDAP-based repository for all network + accounts (both for POSIX accounts and for Samba accounts) provides the most elegant and + controllable facility. You eventually appreciate the decision to use LDAP. + </para> + + <para> + <indexterm><primary>nss_ldap</primary></indexterm> + <indexterm><primary>identifiers</primary></indexterm> + <indexterm><primary>resolve</primary></indexterm> + If your network account information resides in an LDAP repository, you should use it ahead of any + alternative method. This means that if it is humanly possible to use the <command>nss_ldap</command> + tools to resolve UNIX account UIDs/GIDs via LDAP, this is the preferred solution, because it provides + a more readily controllable method for asserting the exact same user and group identifiers + throughout the network. + </para> + + <para> + <indexterm><primary>Domain Member</primary><secondary>server</secondary></indexterm> + <indexterm><primary>winbind trusted domains only</primary></indexterm> + <indexterm><primary>getpwnam</primary></indexterm> + <indexterm><primary>smbd</primary></indexterm> + <indexterm><primary>Trusted Domains</primary></indexterm> + <indexterm><primary>External Domains</primary></indexterm> + In the situation where UNIX accounts are held on the domain member server itself, the only effective + way to use them involves the &smb.conf; entry + <smbconfoption name="winbind trusted domains only">Yes</smbconfoption>. This forces + Samba (<command>smbd</command>) to perform a <command>getpwnam()</command> system call that can + then be controlled via <filename>/etc/nsswitch.conf</filename> file settings. The use of this parameter + disables the use of Samba with trusted domains (i.e., external domains). + </para> + + <para> + <indexterm><primary>appliance mode</primary></indexterm> + <indexterm><primary>Domain Member</primary><secondary>server</secondary></indexterm> + <indexterm><primary>winbindd</primary></indexterm> + <indexterm><primary>automatically allocate</primary></indexterm> + Winbind can be used to create an appliance mode domain member server. In this capacity, <command>winbindd</command> + is configured to automatically allocate UIDs/GIDs from numeric ranges set in the &smb.conf; file. The allocation + is made for all accounts that connect to that domain member server, whether within its own domain or from + trusted domains. If not stored in an LDAP backend, each domain member maintains its own unique mapping database. + This means that it is almost certain that a given user who accesses two domain member servers does not have the + same UID/GID on both servers &smbmdash; however, this is transparent to the Windows network user. This data + is stored in the <filename>winbindd_idmap.tdb</filename> and <filename>winbindd_cache.tdb</filename> files. + </para> + + <para> + <indexterm><primary>mapping</primary></indexterm> + The use of an LDAP backend for the Winbind IDMAP facility permits Windows domain SIDs + mappings to UIDs/GIDs to be stored centrally. The result is a consistent mapping across all domain member + servers so configured. This solves one of the major headaches for network administrators who need to copy + files between or across network file servers. + </para> + + </sect2> + + <sect2> + <title>Political Issues</title> + + <para> + <indexterm><primary>OpenLDAP</primary></indexterm> + <indexterm><primary>NIS</primary></indexterm> + <indexterm><primary>yellow pages</primary><see>NIS</see></indexterm> + <indexterm><primary>identity management</primary></indexterm> + One of the most fierce conflicts recently being waged is resistance to the adoption of LDAP, in + particular OpenLDAP, as a replacement for UNIX NIS (previously called Yellow Pages). Let's face it, LDAP + is different and requires a new approach to the need for a better identity management solution. The more + you work with LDAP, the more its power and flexibility emerges from its dark, cavernous chasm. + </para> + + <para> + LDAP is a most suitable solution for heterogenous environments. If you need crypto, add Kerberos. + The reason these are preferable is because they are heterogenous. Windows solutions of this sort are <emphasis>not</emphasis> + heterogenous by design. This is fundamental &smbmdash; it isn't religious or political. This also doesn't say that + you can't use Windows Active Directory in a heterogenous environment &smbmdash; it can be done, it just requires + commercial integration products. But it's not what Active Directory was designed for. + </para> + + <para> + <indexterm><primary>directory</primary></indexterm> + <indexterm><primary>management</primary></indexterm> + A number of long-term UNIX devotees have recently commented in various communications that the Samba Team + is the first application group to almost force network administrators to use LDAP. It should be pointed + out that we resisted this for as long as we could. It is not out of laziness or malice that LDAP has + finally emerged as the preferred identity management backend for Samba. We recommend LDAP for your total + organizational directory needs. + </para> + + </sect2> + +</sect1> + +<sect1> + <title>Implementation</title> + + <para> + <indexterm><primary>Domain Member</primary><secondary>server</secondary></indexterm> + <indexterm><primary>Domain Member</primary><secondary>client</secondary></indexterm> + <indexterm><primary>Domain Controller</primary></indexterm> + The domain member server and the domain member client are at the center of focus in this chapter. + Configuration of Samba-3 domain controller is covered in earlier chapters, so if your + interest is in domain controller configuration, you will not find that here. You will find good + oil that helps you to add domain member servers and clients. + </para> + + <para> + <indexterm><primary>Domain Member</primary><secondary>workstations</secondary></indexterm> + In practice, domain member servers and domain member workstations are very different entities, but in + terms of technology they share similar core infrastructure. A technologist would argue that servers + and workstations are identical. Many users would argue otherwise, given that in a well-disciplined + environment a workstation (client) is a device from which a user creates documents and files that + are located on servers. A workstation is frequently viewed as a disposable (easy to replace) item, + but a server is viewed as a core component of the business. + </para> + + <para> + <indexterm><primary>workstation</primary></indexterm> + We can look at this another way. If a workstation breaks down, one user is affected, but if a + server breaks down, hundreds of users may not be able to work. The services that a workstation + must provide are document- and file-production oriented; a server provides information storage + and is distribution oriented. + </para> + + <para> + <indexterm><primary>authentication process</primary></indexterm> + <indexterm><primary>logon process</primary></indexterm> + <indexterm><primary>user identities</primary></indexterm> + <emphasis>Why is this important?</emphasis> For starters, we must identify what + components of the operating system and its environment must be configured. Also, it is necessary + to recognize where the interdependencies between the various services to be used are. + In particular, it is important to understand the operation of each critical part of the + authentication process, the logon process, and how user identities get resolved and applied + within the operating system and applications (like Samba) that depend on this and may + actually contribute to it. + </para> + + <para> + So, in this chapter we demonstrate how to implement the technology. It is done within a context of + what type of service need must be fulfilled. + </para> + + <sect2 id="sdcsdmldap"> + <title>Samba Domain with Samba Domain Member Server &smbmdash; Using NSS LDAP</title> + + <para> + <indexterm><primary>ldapsam</primary></indexterm> + <indexterm><primary>ldapsam backend</primary></indexterm> + <indexterm><primary>IDMAP</primary></indexterm> + <indexterm><primary>mapping</primary><secondary>consistent</secondary></indexterm> + <indexterm><primary>winbindd</primary></indexterm> + <indexterm><primary>foreign SID</primary></indexterm> + In this example, it is assumed that you have Samba PDC/BDC servers. This means you are using + an LDAP ldapsam backend. We are adding to the LDAP backend database (directory) + containers for use by the IDMAP facility. This makes it possible to have globally consistent + mapping of SIDs to and from UIDs and GIDs. This means that it is necessary to run + <command>winbindd</command> as part of your configuration. The primary purpose of running + <command>winbindd</command> (within this operational context) is to permit mapping of foreign + SIDs (those not originating from the the local Samba server). Foreign SIDs can come from any + domain member client or server, or from Windows clients that do not belong to a domain. Another + way to explain the necessity to run <command>winbindd</command> is that Samba can locally + resolve only accounts that belong to the security context of its own machine SID. Winbind + handles all non-local SIDs and maps them to a local UID/GID value. The UID and GID are allocated + from the parameter values set in the &smb.conf; file for the <parameter>idmap uid</parameter> and + <parameter>idmap gid</parameter> ranges. Where LDAP is used, the mappings can be stored in LDAP + so that all domain member servers can use a consistent mapping. + </para> + + <para> + <indexterm><primary>winbindd</primary></indexterm> + <indexterm><primary>getpwnam</primary></indexterm> + <indexterm><primary>NSS</primary></indexterm> + If your installation is accessed only from clients that are members of your own domain, and all + user accounts are present in a local passdb backend then it is not necessary to run + <command>winbindd</command>. The local passdb backend can be in smbpasswd, tdbsam, or in ldapsam. + </para> + + <para> + It is possible to use a local passdb backend with any convenient means of resolving the POSIX + user and group account information. The POSIX information is usually obtained using the + <command>getpwnam()</command> system call. On NSS-enabled systems, the actual POSIX account + source can be provided from + </para> + + <itemizedlist> + <listitem><para> + <indexterm><primary>/etc/passwd</primary></indexterm> + <indexterm><primary>/etc/group</primary></indexterm> + Accounts in <filename>/etc/passwd</filename> or in <filename>/etc/group</filename>. + </para></listitem> + + <listitem><para> + <indexterm><primary>NSS</primary></indexterm> + <indexterm><primary>compat</primary></indexterm> + <indexterm><primary>ldap</primary></indexterm> + <indexterm><primary>nis</primary></indexterm> + <indexterm><primary>nisplus</primary></indexterm> + <indexterm><primary>hesiod</primary></indexterm> + <indexterm><primary>ldap</primary></indexterm> + <indexterm><primary>nss_ldap</primary></indexterm> + <indexterm><primary>PADL Software</primary></indexterm> + Resolution via NSS. On NSS-enabled systems, there is usually a facility to resolve IDs + via multiple methods. The methods typically include <command>files</command>, + <command>compat</command>, <command>db</command>, <command>ldap</command>, + <command>nis</command>, <command>nisplus</command>, <command>hesiod.</command> When + correctly installed, Samba adds to this list the <command>winbindd</command> facility. + The ldap facility is frequently the nss_ldap tool provided by PADL Software. + </para></listitem> + </itemizedlist> + + <note><para> + To advoid confusion the use of the term <literal>local passdb backend</literal> means that + the user account backend is not shared by any other Samba server &smbmdash; instead, it is + used only locally on the Samba domain member server under discussion. + </para></note> + + <para> + <indexterm><primary>Identity resolution</primary></indexterm> + The diagram in <link linkend="ch9-sambadc"/> demonstrates the relationship of Samba and system + components that are involved in the identity resolution process where Samba is used as a domain + member server within a Samba domain control network. + </para> + +<figure id="ch9-sambadc"> + <title>Samba Domain: Samba Member Server</title> + <imagefile scale="60">chap9-SambaDC</imagefile> +</figure> + + <para> + <indexterm><primary>IDMAP</primary></indexterm> + <indexterm><primary>foreign</primary></indexterm> + In this example configuration, Samba will directly search the LDAP-based passwd backend ldapsam + to obtain authentication and user identity information. The IDMAP information is stored in the LDAP + backend so that it can be shared by all domain member servers so that every user will have a + consistent UID and GID across all of them. The IDMAP facility will be used for all foreign + (i.e., not having the same SID as the domain it is a member of) domains. The configuration of + NSS will ensure that all UNIX processes will obtain a consistent UID/GID. + </para> + + <para> + The instructions given here apply to the Samba environment shown in <link linkend="happy"/> and <link linkend="2000users"/>. + If the network does not have an LDAP slave server (i.e., <link linkend="happy"/> configuration), + change the target LDAP server from <constant>lapdc</constant> to <constant>massive.</constant> + </para> + + <procedure> + <title>Configuration of NSS_LDAP-Based Identity Resolution</title> + + <step><para> + Create the &smb.conf; file as shown in <link linkend="ch9-sdmsdc"/>. Locate + this file in the directory <filename>/etc/samba</filename>. + </para></step> + + <step><para> + <indexterm><primary>ldap.conf</primary></indexterm> + Configure the file that will be used by <constant>nss_ldap</constant> to + locate and communicate with the LDAP server. This file is called <filename>ldap.conf</filename>. + If your implementation of <constant>nss_ldap</constant> is consistent with + the defaults suggested by PADL (the authors), it will be located in the + <filename>/etc</filename> directory. On some systems, the default location is + the <filename>/etc/openldap</filename> directory, however this file is intended + for use by the OpenLDAP utilities and should not really be used by the nss_ldap + utility since its content and structure serves the specific purpose of enabling + the resolution of user and group IDs via NSS. + </para> + + <para> + Change the parameters inside the file that is located on your OS so it matches + <link linkend="ch9-sdmlcnf"/>. To find the correct location of this file, you + can obtain this from the library that will be used by executing the following: +<screen> +&rootprompt; strings /lib/libnss_ldap* | grep ldap.conf +/etc/ldap.conf +</screen> + </para></step> + + <step><para> + Configure the NSS control file so it matches the one shown in + <link linkend="ch9-sdmnss"/>. + </para></step> + + <step><para> + <indexterm><primary>Identity resolution</primary></indexterm> + <indexterm><primary>getent</primary></indexterm> + Before proceeding to configure Samba, validate the operation of the NSS identity + resolution via LDAP by executing: +<screen> +&rootprompt; getent passwd +... +root:x:0:512:Netbios Domain Administrator:/root:/bin/false +nobody:x:999:514:nobody:/dev/null:/bin/false +bobj:x:1000:513:Robert Jordan:/home/bobj:/bin/bash +stans:x:1001:513:Stanley Soroka:/home/stans:/bin/bash +chrisr:x:1002:513:Christine Roberson:/home/chrisr:/bin/bash +maryv:x:1003:513:Mary Vortexis:/home/maryv:/bin/bash +jht:x:1004:513:John H Terpstra:/home/jht:/bin/bash +bldg1$:x:1006:553:bldg1$:/dev/null:/bin/false +temptation$:x:1009:553:temptation$:/dev/null:/bin/false +vaioboss$:x:1005:553:vaioboss$:/dev/null:/bin/false +fran$:x:1008:553:fran$:/dev/null:/bin/false +josephj:x:1007:513:Joseph James:/home/josephj:/bin/bash +</screen> + You should notice the location of the users' home directories. First, make certain that + the home directories exist on the domain member server; otherwise, the home directory + share is not available. The home directories could be mounted off a domain controller + using NFS or by any other suitable means. Second, the absence of the domain name in the + home directory path is indicative that identity resolution is not being done via winbind. +<screen> +&rootprompt; getent group +... +Domain Admins:x:512:root,jht +Domain Users:x:513:bobj,stans,chrisr,maryv,jht,josephj +Domain Guests:x:514: +Accounts:x:1000: +Finances:x:1001: +PIOps:x:1002: +sammy:x:4321: +</screen> + <indexterm><primary>secondary group</primary></indexterm> + <indexterm><primary>primary group</primary></indexterm> + <indexterm><primary>group membership</primary></indexterm> + This shows that all is working as it should be. Notice that in the LDAP database + the users' primary and secondary group memberships are identical. It is not + necessary to add secondary group memberships (in the group database) if the + user is already a member via primary group membership in the password database. + When using winbind, it is in fact undesirable to do this because it results in + doubling up of group memberships and may cause problems with winbind under certain + conditions. It is intended that these limitations with winbind will be resolved soon + after Samba-3.0.20 has been released. + </para></step> + + <step><para> + <indexterm><primary>slapcat</primary></indexterm> + The LDAP directory must have a container object for IDMAP data. There are several ways you can + check that your LDAP database is able to receive IDMAP information. One of the simplest is to + execute: +<screen> +&rootprompt; slapcat | grep -i idmap +dn: ou=Idmap,dc=abmas,dc=biz +ou: idmap +</screen> + <indexterm><primary>ldapadd</primary></indexterm> + If the execution of this command does not return IDMAP entries, you need to create an LDIF + template file (see <link linkend="ch9-ldifadd"/>). You can add the required entries using + the following command: +<screen> +&rootprompt; ldapadd -x -D "cn=Manager,dc=abmas,dc=biz" \ + -w not24get < /etc/openldap/idmap.LDIF +</screen> + </para></step> + + <step><para> + Samba automatically populates the LDAP directory container when it needs to. To permit Samba + write access to the LDAP directory it is necessary to set the LDAP administrative password + in the <filename>secrets.tdb</filename> file as shown here: +<screen> +&rootprompt; smbpasswd -w not24get +</screen> + </para></step> + + <step><para> + <indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>join</tertiary></indexterm> + <indexterm><primary>Domain join</primary></indexterm> + The system is ready to join the domain. Execute the following: +<screen> +&rootprompt; net rpc join -U root%not24get +Joined domain MEGANET2. +</screen> + This indicates that the domain join succeeded. + </para> + + <para> + Failure to join the domain could be caused by any number of variables. The most common + causes of failure to join are: + </para> + + <para> + <itemizedlist> + <listitem><para>Broken resolution of NetBIOS names to the respective IP address.</para></listitem> + <listitem><para>Incorrect username and password credentials.</para></listitem> + <listitem><para>The NT4 <parameter>restrict anonymous</parameter> is set to exclude anonymous + connections.</para></listitem> + </itemizedlist> + </para> + + <para> + The connection setup can be diagnosed by executing: +<screen> +&rootprompt; net rpc join -S 'pdc-name' -U administrator%password -d 5 +</screen> + <indexterm><primary>failed</primary></indexterm> + <indexterm><primary>failed join</primary></indexterm> + <indexterm><primary>rejected</primary></indexterm> + <indexterm><primary>restrict anonymous</primary></indexterm> + Note: Use "root" for UNIX/Linux and Samba, use "Administrator" for Windows NT4/200X. If the cause of + the failure appears to be related to a rejected or failed NT_SESSION_SETUP* or an error message that + says NT_STATUS_ACCESS_DENIED immediately check the Windows registry setting that controls the + <constant>restrict anonymous</constant> setting. Set this to the value 0 so that an anonymous connection + can be sustained, then try again. + </para> + + <para> + It is possible (perhaps even recommended) to use the following to validate the ability to connect + to an NT4 PDC/BDC: +<screen> +&rootprompt; net rpc info -S 'pdc-name' -U Administrator%not24get +Domain Name: MEGANET2 +Domain SID: S-1-5-21-422319763-4138913805-7168186429 +Sequence number: 1519909596 +Num users: 7003 +Num domain groups: 821 +Num local groups: 8 + +&rootprompt; net rpc testjoin -S 'pdc-name' -U Administrator%not24get +Join to 'MEGANET2' is OK +</screen> + If for any reason the following response is obtained to the last command above,it is time to + call in the Networking Super-Snooper task force (i.e., start debugging): +<screen> +NT_STATUS_ACCESS_DENIED +Join to 'MEGANET2' failed. +</screen> + </para></step> + + <step><para> + <indexterm><primary>wbinfo</primary></indexterm> + Just joining the domain is not quite enough; you must now provide a privileged set + of credentials through which <command>winbindd</command> can interact with the + domain servers. Execute the following to implant the necessary credentials: +<screen> +&rootprompt; wbinfo --set-auth-user=Administrator%not24get +</screen> + The configuration is now ready to obtain the Samba domain user and group information. + </para></step> + + <step><para> + You may now start Samba in the usual manner, and your Samba domain member server + is ready for use. Just add shares as required. + </para></step> + + </procedure> + +<example id="ch9-sdmsdc"> +<title>Samba Domain Member in Samba Domain Using LDAP &smbmdash; &smb.conf; File</title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="unix charset">LOCALE</smbconfoption> +<smbconfoption name="workgroup">MEGANET2</smbconfoption> +<smbconfoption name="security">DOMAIN</smbconfoption> +<smbconfoption name="username map">/etc/samba/smbusers</smbconfoption> +<smbconfoption name="log level">10</smbconfoption> +<smbconfoption name="syslog">0</smbconfoption> +<smbconfoption name="log file">/var/log/samba/%m</smbconfoption> +<smbconfoption name="max log size">50</smbconfoption> +<smbconfoption name="smb ports">139</smbconfoption> +<smbconfoption name="name resolve order">wins bcast hosts</smbconfoption> +<smbconfoption name="printcap name">CUPS</smbconfoption> +<smbconfoption name="wins server">192.168.2.1</smbconfoption> +<smbconfoption name="ldap suffix">dc=abmas,dc=biz</smbconfoption> +<smbconfoption name="ldap machine suffix">ou=People</smbconfoption> +<smbconfoption name="ldap user suffix">ou=People</smbconfoption> +<smbconfoption name="ldap group suffix">ou=Groups</smbconfoption> +<smbconfoption name="ldap idmap suffix">ou=Idmap</smbconfoption> +<smbconfoption name="ldap admin dn">cn=Manager,dc=abmas,dc=biz</smbconfoption> +<smbconfoption name="idmap backend">ldap:ldap://lapdc.abmas.biz</smbconfoption> +<smbconfoption name="idmap uid">10000-20000</smbconfoption> +<smbconfoption name="idmap gid">10000-20000</smbconfoption> +<smbconfoption name="winbind trusted domains only">Yes</smbconfoption> +<smbconfoption name="printer admin">root</smbconfoption> +<smbconfoption name="printing">cups</smbconfoption> + +<smbconfsection name="[homes]"/> +<smbconfoption name="comment">Home Directories</smbconfoption> +<smbconfoption name="valid users">%S</smbconfoption> +<smbconfoption name="read only">No</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[printers]"/> +<smbconfoption name="comment">SMB Print Spool</smbconfoption> +<smbconfoption name="path">/var/spool/samba</smbconfoption> +<smbconfoption name="guest ok">Yes</smbconfoption> +<smbconfoption name="printable">Yes</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[print$]"/> +<smbconfoption name="comment">Printer Drivers</smbconfoption> +<smbconfoption name="path">/var/lib/samba/drivers</smbconfoption> +<smbconfoption name="admin users">root, Administrator</smbconfoption> +<smbconfoption name="write list">root</smbconfoption> +</smbconfblock> +</example> + +<example id="ch9-ldifadd"> +<title>LDIF IDMAP Add-On Load File &smbmdash; File: /etc/openldap/idmap.LDIF</title> +<screen> +dn: ou=Idmap,dc=abmas,dc=biz +objectClass: organizationalUnit +ou: idmap +structuralObjectClass: organizationalUnit +</screen> +</example> + +<example id="ch9-sdmlcnf"> +<title>Configuration File for NSS LDAP Support &smbmdash; <filename>/etc/ldap.conf</filename></title> +<screen> +URI ldap://massive.abmas.biz ldap://massive.abmas.biz:636 +host 192.168.2.1 +base dc=abmas,dc=biz +binddn cn=Manager,dc=abmas,dc=biz +bindpw not24get + +pam_password exop + +nss_base_passwd ou=People,dc=abmas,dc=biz?one +nss_base_shadow ou=People,dc=abmas,dc=biz?one +nss_base_group ou=Groups,dc=abmas,dc=biz?one +ssl no +</screen> +</example> + +<example id="ch9-sdmnss"> +<title>NSS using LDAP for Identity Resolution &smbmdash; File: <filename>/etc/nsswitch.conf</filename></title> +<screen> +passwd: files ldap +shadow: files ldap +group: files ldap + +hosts: files dns wins +networks: files dns + +services: files +protocols: files +rpc: files +ethers: files +netmasks: files +netgroup: files +publickey: files + +bootparams: files +automount: files +aliases: files +</screen> +</example> + + </sect2> + + <sect2 id="wdcsdm"> + <title>NT4/Samba Domain with Samba Domain Member Server: Using NSS and Winbind</title> + + <para> + You need to use this method for creating a Samba domain member server if any of the following conditions + prevail: + </para> + + <itemizedlist> + <listitem><para> + LDAP support (client) is not installed on the system. + </para></listitem> + + <listitem><para> + There are mitigating circumstances forcing a decision not to use LDAP. + </para></listitem> + + <listitem><para> + The Samba domain member server must be part of a Windows NT4 Domain, or a Samba Domain. + </para></listitem> + </itemizedlist> + + <para> + <indexterm><primary>Windows ADS Domain</primary></indexterm> + <indexterm><primary>Samba Domain</primary></indexterm> + <indexterm><primary>LDAP</primary></indexterm> + Later in the chapter, you can see how to configure a Samba domain member server for a Windows ADS domain. + Right now your objective is to configure a Samba server that can be a member of a Windows NT4-style + domain and/or does not use LDAP. + </para> + + <note><para> + <indexterm><primary>duplicate accounts</primary></indexterm> + If you use <command>winbind</command> for identity resolution, make sure that there are no + duplicate accounts. + </para> + + <para> + <indexterm><primary>/etc/passwd</primary></indexterm> + For example, do not have more than one account that has UID=0 in the password database. If there + is an account called <constant>root</constant> in the <filename>/etc/passwd</filename> database, + it is okay to have an account called <constant>root</constant> in the LDAP ldapsam or in the + tdbsam. But if there are two accounts in the passdb backend that have the same UID, winbind will + break. This means that the <constant>Administrator</constant> account must be called + <constant>root</constant>. + </para> + + <para> + <indexterm><primary>/etc/passwd</primary></indexterm> + <indexterm><primary>ldapsam</primary></indexterm> + <indexterm><primary>tdbsam</primary></indexterm> + Winbind will break if there is an account in <filename>/etc/passwd</filename> that has + the same UID as an account that is in LDAP ldapsam (or in tdbsam) but that differs in name only. + </para></note> + + <para> + <indexterm><primary>credentials</primary></indexterm> + <indexterm><primary>traverse</primary></indexterm> + <indexterm><primary>wide-area</primary></indexterm> + <indexterm><primary>network</primary><secondary>wide-area</secondary></indexterm> + <indexterm><primary>tdbdump</primary></indexterm> + The following configuration uses CIFS/SMB protocols alone to obtain user and group credentials. + The winbind information is locally cached in the <filename>winbindd_cache.tdb winbindd_idmap.tdb</filename> + files. This provides considerable performance benefits compared with the LDAP solution, particularly + where the LDAP lookups must traverse WAN links. You may examine the contents of these + files using the tool <command>tdbdump</command>, though you may have to build this from the Samba + source code if it has not been supplied as part of a binary package distribution that you may be using. + </para> + + <procedure> + <title>Configuration of Winbind-Based Identity Resolution</title> + + <step><para> + Using your favorite text editor, create the &smb.conf; file so it has the contents + shown in <link linkend="ch0-NT4DSDM"/>. + </para></step> + + <step><para> + <indexterm><primary>/etc/nsswitch.conf</primary></indexterm> + Edit the <filename>/etc/nsswitch.conf</filename> so it has the entries shown in + <link linkend="ch9-sdmnss"/>. + </para></step> + + <step><para> + <indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>join</tertiary></indexterm> + The system is ready to join the domain. Execute the following: +<screen> +net rpc join -U root%not2g4et +Joined domain MEGANET2. +</screen> + This indicates that the domain join succeed. + + </para></step> + + <step><para> + <indexterm><primary>winbind</primary></indexterm> + <indexterm><primary>wbinfo</primary></indexterm> + Validate operation of <command>winbind</command> using the <command>wbinfo</command> + tool as follows: +<screen> +&rootprompt; wbinfo -u +MEGANET2+root +MEGANET2+nobody +MEGANET2+jht +MEGANET2+maryv +MEGANET2+billr +MEGANET2+jelliott +MEGANET2+dbrady +MEGANET2+joeg +MEGANET2+balap +</screen> + This shows that domain users have been listed correctly. +<screen> +&rootprompt; wbinfo -g +MEGANET2+Domain Admins +MEGANET2+Domain Users +MEGANET2+Domain Guests +MEGANET2+Accounts +MEGANET2+Finances +MEGANET2+PIOps +</screen> + This shows that domain groups have been correctly obtained also. + </para></step> + + <step><para> + <indexterm><primary>NSS</primary></indexterm> + <indexterm><primary>getent</primary></indexterm> + <indexterm><primary>winbind</primary></indexterm> + The next step verifies that NSS is able to obtain this information + correctly from <command>winbind</command> also. +<screen> +&rootprompt; getent passwd +... +MEGANET2+root:x:10000:10001:NetBIOS Domain Admin: + /home/MEGANET2/root:/bin/bash +MEGANET2+nobody:x:10001:10001:nobody: + /home/MEGANET2/nobody:/bin/bash +MEGANET2+jht:x:10002:10001:John H Terpstra: + /home/MEGANET2/jht:/bin/bash +MEGANET2+maryv:x:10003:10001:Mary Vortexis: + /home/MEGANET2/maryv:/bin/bash +MEGANET2+billr:x:10004:10001:William Randalph: + /home/MEGANET2/billr:/bin/bash +MEGANET2+jelliott:x:10005:10001:John G Elliott: + /home/MEGANET2/jelliott:/bin/bash +MEGANET2+dbrady:x:10006:10001:Darren Brady: + /home/MEGANET2/dbrady:/bin/bash +MEGANET2+joeg:x:10007:10001:Joe Green: + /home/MEGANET2/joeg:/bin/bash +MEGANET2+balap:x:10008:10001:Bala Pillay: + /home/MEGANET2/balap:/bin/bash +</screen> + The user account information has been correctly obtained. This information has + been merged with the winbind template information configured in the &smb.conf; file. +<screen> +&rootprompt;# getent group +... +MEGANET2+Domain Admins:x:10000:MEGANET2+root,MEGANET2+jht +MEGANET2+Domain Users:x:10001:MEGANET2+jht,MEGANET2+maryv,\ + MEGANET2+billr,MEGANET2+jelliott,MEGANET2+dbrady,\ + MEGANET2+joeg,MEGANET2+balap +MEGANET2+Domain Guests:x:10002:MEGANET2+nobody +MEGANET2+Accounts:x:10003: +MEGANET2+Finances:x:10004: +MEGANET2+PIOps:x:10005: +</screen> + </para></step> + + <step><para> + The Samba member server of a Windows NT4 domain is ready for use. + </para></step> + + </procedure> + +<example id="ch0-NT4DSDM"> +<title>Samba Domain Member Server Using Winbind &smb.conf; File for NT4 Domain</title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="unix charset">LOCALE</smbconfoption> +<smbconfoption name="workgroup">MEGANET2</smbconfoption> +<smbconfoption name="security">DOMAIN</smbconfoption> +<smbconfoption name="username map">/etc/samba/smbusers</smbconfoption> +<smbconfoption name="log level">1</smbconfoption> +<smbconfoption name="syslog">0</smbconfoption> +<smbconfoption name="log file">/var/log/samba/%m</smbconfoption> +<smbconfoption name="max log size">0</smbconfoption> +<smbconfoption name="smb ports">139</smbconfoption> +<smbconfoption name="name resolve order">wins bcast hosts</smbconfoption> +<smbconfoption name="printcap name">CUPS</smbconfoption> +<smbconfoption name="wins server">192.168.2.1</smbconfoption> +<smbconfoption name="idmap uid">10000-20000</smbconfoption> +<smbconfoption name="idmap gid">10000-20000</smbconfoption> +<smbconfoption name="template primary group">"Domain Users"</smbconfoption> +<smbconfoption name="template shell">/bin/bash</smbconfoption> +<smbconfoption name="winbind separator">+</smbconfoption> +<smbconfoption name="printer admin">root</smbconfoption> +<smbconfoption name="hosts allow">192.168.2., 192.168.3., 127.</smbconfoption> +<smbconfoption name="printing">cups</smbconfoption> + +<smbconfsection name="[homes]"/> +<smbconfoption name="comment">Home Directories</smbconfoption> +<smbconfoption name="valid users">%S</smbconfoption> +<smbconfoption name="read only">No</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[printers]"/> +<smbconfoption name="comment">SMB Print Spool</smbconfoption> +<smbconfoption name="path">/var/spool/samba</smbconfoption> +<smbconfoption name="guest ok">Yes</smbconfoption> +<smbconfoption name="printable">Yes</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[print$]"/> +<smbconfoption name="comment">Printer Drivers</smbconfoption> +<smbconfoption name="path">/var/lib/samba/drivers</smbconfoption> +<smbconfoption name="admin users">root, Administrator</smbconfoption> +<smbconfoption name="write list">root</smbconfoption> +</smbconfblock> +</example> + + </sect2> + + <sect2 id="dcwonss"> + <title>NT4/Samba Domain with Samba Domain Member Server without NSS Support</title> + + <para> + No matter how many UNIX/Linux administrators there may be who believe that a UNIX operating + system that does not have NSS and PAM support to be outdated, the fact is there + are still many such systems in use today. Samba can be used without NSS support, but this + does limit it to the use of local user and group accounts only. + </para> + + <para> + The following steps may be followed to implement Samba with support for local accounts. + In this configuration Samba is made a domain member server. All incoming connections + to the Samba server will cause the look-up of the incoming username. If the account + is found, it is used. If the account is not found, one will be automatically created + on the local machine so that it can then be used for all access controls. + </para> + + <procedure> + <title>Configuration Using Local Accounts Only</title> + + <step><para> + Using your favorite text editor, create the &smb.conf; file so it has the contents + shown in <link linkend="ch0-NT4DSCM"/>. + </para></step> + + <step> + <para><indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>join</tertiary></indexterm> + The system is ready to join the domain. Execute the following: +<screen> +net rpc join -U root%not24get +Joined domain MEGANET2. +</screen> + This indicates that the domain join succeed. + </para></step> + + <step><para> + Be sure to run all three Samba daemons: <command>smbd</command>, <command>nmbd</command>, <command>winbindd</command>. + </para></step> + + <step><para> + The Samba member server of a Windows NT4 domain is ready for use. + </para></step> + </procedure> + +<example id="ch0-NT4DSCM"> +<title>Samba Domain Member Server Using Local Accounts &smb.conf; File for NT4 Domain</title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="unix charset">LOCALE</smbconfoption> +<smbconfoption name="workgroup">MEGANET3</smbconfoption> +<smbconfoption name="netbios name">BSDBOX</smbconfoption> +<smbconfoption name="security">DOMAIN</smbconfoption> +<smbconfoption name="username map">/etc/samba/smbusers</smbconfoption> +<smbconfoption name="log level">1</smbconfoption> +<smbconfoption name="syslog">0</smbconfoption> +<smbconfoption name="add user script">/usr/sbin/useradd -m '%u'</smbconfoption> +<smbconfoption name="add machine script">/usr/sbin/useradd -M '%u'</smbconfoption> +<smbconfoption name="add group script">/usr/sbin/groupadd '%g'</smbconfoption> +<smbconfoption name="log file">/var/log/samba/%m</smbconfoption> +<smbconfoption name="max log size">0</smbconfoption> +<smbconfoption name="smb ports">139</smbconfoption> +<smbconfoption name="name resolve order">wins bcast hosts</smbconfoption> +<smbconfoption name="printcap name">CUPS</smbconfoption> +<smbconfoption name="wins server">192.168.2.1</smbconfoption> +<smbconfoption name="printer admin">root</smbconfoption> +<smbconfoption name="hosts allow">192.168.2., 192.168.3., 127.</smbconfoption> +<smbconfoption name="printing">cups</smbconfoption> + +<smbconfsection name="[homes]"/> +<smbconfoption name="comment">Home Directories</smbconfoption> +<smbconfoption name="valid users">%S</smbconfoption> +<smbconfoption name="read only">No</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[printers]"/> +<smbconfoption name="comment">SMB Print Spool</smbconfoption> +<smbconfoption name="path">/var/spool/samba</smbconfoption> +<smbconfoption name="guest ok">Yes</smbconfoption> +<smbconfoption name="printable">Yes</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[print$]"/> +<smbconfoption name="comment">Printer Drivers</smbconfoption> +<smbconfoption name="path">/var/lib/samba/drivers</smbconfoption> +<smbconfoption name="admin users">root, Administrator</smbconfoption> +<smbconfoption name="write list">root</smbconfoption> +</smbconfblock> +</example> + </sect2> + + <sect2 id="adssdm"> + <title>Active Directory Domain with Samba Domain Member Server</title> + + <para> + <indexterm><primary>Active Directory</primary><secondary>join</secondary></indexterm> + <indexterm><primary>Kerberos</primary></indexterm> + <indexterm><primary>Domain Member</primary><secondary>server</secondary></indexterm> + One of the much-sought-after features new to Samba-3 is the ability to join an Active Directory + domain using Kerberos protocols. This makes it possible to operate an entire Windows network + without the need to run NetBIOS over TCP/IP and permits more secure networking in general. An + exhaustively complete discussion of the protocols is not possible in this book; perhaps a + later book may explore the intricacies of the NetBIOS-less operation that Samba-3 can participate + in. For now, we simply focus on how a Samba-3 server can be made a domain member server. + </para> + + <para> + <indexterm><primary>Active Directory</primary></indexterm> + <indexterm><primary>LDAP</primary></indexterm> + <indexterm><primary>Identity resolution</primary></indexterm> + <indexterm><primary>Kerberos</primary></indexterm> + The diagram in <link linkend="ch9-adsdc"/> demonstrates how Samba-3 interfaces with + Microsoft Active Directory components. It should be noted that if Microsoft Windows Services + for UNIX (SFU) has been installed and correctly configured, it is possible to use client LDAP + for identity resolution just as can be done with Samba-3 when using an LDAP passdb backend. + The UNIX tool that you need for this, as in the case of LDAP on UNIX/Linux, is the PADL + Software nss_ldap tool-set. Compared with use of winbind and Kerberos, the use of + LDAP-based identity resolution is a little less secure. In view of the fact that this solution + requires additional software to be installed on the Windows 200x ADS domain controllers, + and that means more management overhead, it is likely that most Samba-3 ADS client sites + may elect to use winbind. + </para> + + <para> + Do not attempt to use this procedure if you are not 100 percent certain that the build of Samba-3 + you are using has been compiled and linked with all the tools necessary for this to work. + Given the importance of this step, you must first validate that the Samba-3 message block + daemon (<command>smbd</command>) has the necessary features. + </para> + + <para> + The hypothetical domain you are using in this example assumes that the Abmas London office + decided to take its own lead (some would say this is a typical behavior in a global + corporate world; besides, a little divergence and conflict makes for an interesting life). + The Windows Server 2003 ADS domain is called <constant>london.abmas.biz</constant> and the + name of the server is <constant>W2K3S</constant>. In ADS realm terms, the domain controller + is known as <constant>w2k3s.london.abmas.biz</constant>. In NetBIOS nomenclature, the + domain name is <constant>LONDON</constant> and the server name is <constant>W2K3S</constant>. + </para> + + <figure id="ch9-adsdc"> + <title>Active Directory Domain: Samba Member Server</title> + <imagefile scale="60">chap9-ADSDC</imagefile> + </figure> + + <procedure> + <title>Joining a Samba Server as an ADS Domain Member</title> + + <step><para> + <indexterm><primary>smbd</primary></indexterm> + Before you try to use Samba-3, you want to know for certain that your executables have + support for Kerberos and for LDAP. Execute the following to identify whether or + not this build is perhaps suitable for use: +<screen> +&rootprompt; cd /usr/sbin +&rootprompt; smbd -b | grep KRB + HAVE_KRB5_H + HAVE_ADDR_TYPE_IN_KRB5_ADDRESS + HAVE_KRB5 + HAVE_KRB5_AUTH_CON_SETKEY + HAVE_KRB5_GET_DEFAULT_IN_TKT_ETYPES + HAVE_KRB5_GET_PW_SALT + HAVE_KRB5_KEYBLOCK_KEYVALUE + HAVE_KRB5_KEYTAB_ENTRY_KEYBLOCK + HAVE_KRB5_MK_REQ_EXTENDED + HAVE_KRB5_PRINCIPAL_GET_COMP_STRING + HAVE_KRB5_SET_DEFAULT_IN_TKT_ETYPES + HAVE_KRB5_STRING_TO_KEY + HAVE_KRB5_STRING_TO_KEY_SALT + HAVE_LIBKRB5 +</screen> + This output was obtained on a SUSE Linux system and shows the output for + Samba that has been compiled and linked with the Heimdal Kerberos libraries. + The following is a typical output that will be found on a Red Hat Linux system that + has been linked with the MIT Kerberos libraries: +<screen> +&rootprompt; cd /usr/sbin +&rootprompt; smbd -b | grep KRB + HAVE_KRB5_H + HAVE_ADDRTYPE_IN_KRB5_ADDRESS + HAVE_KRB5 + HAVE_KRB5_AUTH_CON_SETUSERUSERKEY + HAVE_KRB5_ENCRYPT_DATA + HAVE_KRB5_FREE_DATA_CONTENTS + HAVE_KRB5_FREE_KTYPES + HAVE_KRB5_GET_PERMITTED_ENCTYPES + HAVE_KRB5_KEYTAB_ENTRY_KEY + HAVE_KRB5_LOCATE_KDC + HAVE_KRB5_MK_REQ_EXTENDED + HAVE_KRB5_PRINCIPAL2SALT + HAVE_KRB5_PRINC_COMPONENT + HAVE_KRB5_SET_DEFAULT_TGS_KTYPES + HAVE_KRB5_SET_REAL_TIME + HAVE_KRB5_STRING_TO_KEY + HAVE_KRB5_TKT_ENC_PART2 + HAVE_KRB5_USE_ENCTYPE + HAVE_LIBGSSAPI_KRB5 + HAVE_LIBKRB5 +</screen> + You can validate that Samba has been compiled and linked with LDAP support + by executing: +<screen> +&rootprompt; smbd -b | grep LDAP +massive:/usr/sbin # smbd -b | grep LDAP + HAVE_LDAP_H + HAVE_LDAP + HAVE_LDAP_DOMAIN2HOSTLIST + HAVE_LDAP_INIT + HAVE_LDAP_INITIALIZE + HAVE_LDAP_SET_REBIND_PROC + HAVE_LIBLDAP + LDAP_SET_REBIND_PROC_ARGS +</screen> + This does look promising; <command>smbd</command> has been built with Kerberos and LDAP + support. You are relieved to know that it is safe to progress. + </para></step> + + <step><para> + <indexterm><primary>Kerberos</primary><secondary>libraries</secondary></indexterm> + <indexterm><primary>MIT Kerberos</primary></indexterm> + <indexterm><primary>Heimdal Kerberos</primary></indexterm> + <indexterm><primary>Kerberos</primary><secondary>MIT</secondary></indexterm> + <indexterm><primary>Kerberos</primary><secondary>Heimdal</secondary></indexterm> + <indexterm><primary>Red Hat Linux</primary></indexterm> + <indexterm><primary>SUSE Linux</primary></indexterm> + <indexterm><primary>SerNet</primary></indexterm> + <indexterm><primary>validated</primary></indexterm> + The next step is to identify which version of the Kerberos libraries have been used. + In order to permit Samba-3 to interoperate with Windows 2003 Active Directory, it is + essential that it has been linked with either MIT Kerberos version 1.3.1 or later, + or that it has been linked with Heimdal Kerberos 0.6 plus specific patches. You may + identify what version of the MIT Kerberos libraries are installed on your system by + executing (on Red Hat Linux): +<screen> +&rootprompt; rpm -q krb5 +</screen> + Or on SUSE Linux, execute: +<screen> +&rootprompt; rpm -q heimdal +</screen> + Please note that the RPMs provided by the Samba-Team are known to be working and have + been validated. Red Hat Linux RPMs may be obtained from the Samba FTP sites. SUSE + Linux RPMs may be obtained from <ulink url="ftp://ftp.sernet.de">Sernet</ulink> in + Germany. + </para> + + <para> + From this point on, you are certain that the Samba-3 build you are using has the + necessary capabilities. You can now configure Samba-3 and the NSS. + </para></step> + + <step><para> + Using you favorite editor, configure the &smb.conf; file that is located in the + <filename>/etc/samba</filename> directory so that it has the contents shown + in <link linkend="ch9-adssdm"/>. + </para></step> + + <step><para> + Edit or create the NSS control file so it has the contents shown in <link linkend="ch9-sdmnss"/>. + </para></step> + + <step><para> + <indexterm><primary>/etc/samba/secrets.tdb</primary></indexterm> + Delete the file <filename>/etc/samba/secrets.tdb</filename> if it exists. Of course, you + do keep a backup, don't you? + </para></step> + + <step><para> + Delete the tdb files that cache Samba information. You keep a backup of the old + files, of course. You also remove all files to ensure that nothing can pollute your + nice, new configuration. Execute the following (example is for SUSE Linux): +<screen> +&rootprompt; rm /var/lib/samba/*tdb +</screen> + </para></step> + + <step><para> + <indexterm><primary>testparm</primary></indexterm> + Validate your &smb.conf; file using <command>testparm</command> (as you have + done previously). Correct all errors reported before proceeding. The command you + execute is: +<screen> +&rootprompt; testparm -s | less +</screen> + Now that you are satisfied that your Samba server is ready to join the Windows + ADS domain, let's move on. + </para></step> + + <step><para> + <indexterm><primary>net</primary><secondary>ads</secondary><tertiary>join</tertiary></indexterm> + <indexterm><primary>Kerberos</primary></indexterm> + This is a good time to double-check everything and then execute the following + command when everything you have done has checked out okay: +<screen> +&rootprompt; net ads join -UAdministrator%not24get +Using short domain name -- LONDON +Joined 'FRAN' to realm 'LONDON.ABMAS.BIZ' +</screen> + You have successfully made your Samba-3 server a member of the ADS domain + using Kerberos protocols. + </para> + + <para> + <indexterm><primary>silent return</primary></indexterm> + <indexterm><primary>failed join</primary></indexterm> + In the event that you receive no output messages, a silent return means that the + domain join failed. You should use <command>ethereal</command> to identify what + may be failing. Common causes of a failed join include: + + <itemizedlist> + <listitem><para> + <indexterm><primary>name resolution</primary><secondary>Defective</secondary></indexterm> + Defective or misconfigured DNS name resolution. + </para></listitem> + + <listitem><para> + <indexterm><primary>Restrictive security</primary></indexterm> + Restrictive security settings on the Windows 200x ADS domain controller + preventing needed communications protocols. You can check this by searching + the Windows Server 200x Event Viewer. + </para></listitem> + + <listitem><para> + Incorrectly configured &smb.conf; file settings. + </para></listitem> + + <listitem><para> + Lack of support of necessary Kerberos protocols because the version of MIT + Kerberos (or Heimdal) in use is not up to date enough to support the necessary + functionality. + </para></listitem> + </itemizedlist> + + <indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>join</tertiary></indexterm> + <indexterm><primary>RPC</primary></indexterm> + <indexterm><primary>mixed mode</primary></indexterm> + In any case, never execute the <command>net rpc join</command> command in an attempt + to join the Samba server to the domain, unless you wish not to use the Kerberos + security protocols. Use of the older RPC-based domain join facility requires that + Windows Server 200x ADS has been configured appropriately for mixed mode operation. + </para></step> + + <step><para> + <indexterm><primary>tdbdump</primary></indexterm> + <indexterm><primary>/etc/samba/secrets.tdb</primary></indexterm> + If the <command>tdbdump</command> is installed on your system (not essential), + you can look inside the <filename>/etc/samba/secrets.tdb</filename> file. If + you wish to do this, execute: +<screen> +&rootprompt; tdbdump secrets.tdb +{ +key = "SECRETS/SID/LONDON" +data = "\01\04\00\00\00\00\00\05\15\00\00\00\EBw\86\F1\ED\BD\ + F6{\5C6\E5W\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\ + 00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\00\ + 00\00\00\00\00\00\00\00" +} +{ +key = "SECRETS/MACHINE_PASSWORD/LONDON" +data = "le3Q5FPnN5.ueC\00" +} +{ +key = "SECRETS/MACHINE_SEC_CHANNEL_TYPE/LONDON" +data = "\02\00\00\00" +} +{ +key = "SECRETS/MACHINE_LAST_CHANGE_TIME/LONDON" +data = "E\89\F6?" +} +</screen> + This is given to demonstrate to the skeptics that this process truly does work. + </para></step> + + <step><para> + It is now time to start Samba in the usual way (as has been done many time before + in this book). + </para></step> + + <step><para> + <indexterm><primary>wbinfo</primary></indexterm> + This is a good time to verify that everything is working. First, check that + winbind is able to obtain the list of users and groups from the ADS domain controller. + Execute the following: +<screen> +&rootprompt; wbinfo -u +LONDON+Administrator +LONDON+Guest +LONDON+SUPPORT_388945a0 +LONDON+krbtgt +LONDON+jht +</screen> + Good, the list of users was obtained. Now do likewise for group accounts: +<screen> +&rootprompt; wbinfo -g +LONDON+Domain Computers +LONDON+Domain Controllers +LONDON+Schema Admins +LONDON+Enterprise Admins +LONDON+Domain Admins +LONDON+Domain Users +LONDON+Domain Guests +LONDON+Group Policy Creator Owners +LONDON+DnsUpdateProxy +</screen> + Excellent. That worked also, as expected. + </para></step> + + <step><para><indexterm> + <primary>getent</primary> + </indexterm> + Now repeat this via NSS to validate that full identity resolution is + functional as required. Execute: +<screen> +&rootprompt; getent passwd +... +LONDON+Administrator:x:10000:10000:Administrator: + /home/LONDON/administrator:/bin/bash +LONDON+Guest:x:10001:10001:Guest: + /home/LONDON/guest:/bin/bash +LONDON+SUPPORT_388945a0:x:10002:10000:SUPPORT_388945a0: + /home/LONDON/support_388945a0:/bin/bash +LONDON+krbtgt:x:10003:10000:krbtgt: + /home/LONDON/krbtgt:/bin/bash +LONDON+jht:x:10004:10000:John H. Terpstra: + /home/LONDON/jht:/bin/bash +</screen> + Okay, ADS user accounts are being resolved. Now you try group resolution: +<screen> +&rootprompt; getent group +... +LONDON+Domain Computers:x:10002: +LONDON+Domain Controllers:x:10003: +LONDON+Schema Admins:x:10004:LONDON+Administrator +LONDON+Enterprise Admins:x:10005:LONDON+Administrator +LONDON+Domain Admins:x:10006:LONDON+jht,LONDON+Administrator +LONDON+Domain Users:x:10000: +LONDON+Domain Guests:x:10001: +LONDON+Group Policy Creator Owners:x:10007:LONDON+Administrator +LONDON+DnsUpdateProxy:x:10008: +</screen> + This is very pleasing. Everything works as expected. + </para></step> + + <step><para> + <indexterm><primary>net</primary><secondary>ads</secondary><tertiary>info</tertiary></indexterm> + <indexterm><primary>Active Directory</primary><secondary>server</secondary></indexterm> + <indexterm><primary>Kerberos</primary></indexterm> + You may now perform final verification that communications between Samba-3 winbind and + the Active Directory server is using Kerberos protocols. Execute the following: +<screen> +&rootprompt; net ads info +LDAP server: 192.168.2.123 +LDAP server name: w2k3s +Realm: LONDON.ABMAS.BIZ +Bind Path: dc=LONDON,dc=ABMAS,dc=BIZ +LDAP port: 389 +Server time: Sat, 03 Jan 2004 02:44:44 GMT +KDC server: 192.168.2.123 +Server time offset: 2 +</screen> + It should be noted that Kerberos protocols are time-clock critical. You should + keep all server time clocks synchronized using the network time protocol (NTP). + In any case, the output we obtained confirms that all systems are operational. + </para></step> + + <step><para> + <indexterm><primary>net</primary><secondary>ads</secondary><tertiary>status</tertiary></indexterm> + There is one more action you elect to take, just because you are paranoid and disbelieving, + so you execute the following command: +<programlisting> +&rootprompt; net ads status -UAdministrator%not24get +objectClass: top +objectClass: person +objectClass: organizationalPerson +objectClass: user +objectClass: computer +cn: fran +distinguishedName: CN=fran,CN=Computers,DC=london,DC=abmas,DC=biz +instanceType: 4 +whenCreated: 20040103092006.0Z +whenChanged: 20040103092006.0Z +uSNCreated: 28713 +uSNChanged: 28717 +name: fran +objectGUID: 58f89519-c467-49b9-acb0-f099d73696e +userAccountControl: 69632 +badPwdCount: 0 +codePage: 0 +countryCode: 0 +badPasswordTime: 0 +lastLogoff: 0 +lastLogon: 127175965783327936 +localPolicyFlags: 0 +pwdLastSet: 127175952062598496 +primaryGroupID: 515 +objectSid: S-1-5-21-4052121579-2079768045-1474639452-1109 +accountExpires: 9223372036854775807 +logonCount: 13 +sAMAccountName: fran$ +sAMAccountType: 805306369 +operatingSystem: Samba +operatingSystemVersion: 3.0.20-SUSE +dNSHostName: fran +userPrincipalName: HOST/fran@LONDON.ABMAS.BIZ +servicePrincipalName: CIFS/fran.london.abmas.biz +servicePrincipalName: CIFS/fran +servicePrincipalName: HOST/fran.london.abmas.biz +servicePrincipalName: HOST/fran +objectCategory: CN=Computer,CN=Schema,CN=Configuration, + DC=london,DC=abmas,DC=biz +isCriticalSystemObject: FALSE +-------------- Security Descriptor (revision: 1, type: 0x8c14) +owner SID: S-1-5-21-4052121579-2079768045-1474639452-512 +group SID: S-1-5-21-4052121579-2079768045-1474639452-513 +------- (system) ACL (revision: 4, size: 120, number of ACEs: 2) +------- ACE (type: 0x07, flags: 0x5a, size: 0x38, + mask: 0x20, object flags: 0x3) +access SID: S-1-1-0 +access type: AUDIT OBJECT +Permissions: + [Write All Properties] +------- ACE (type: 0x07, flags: 0x5a, size: 0x38, + mask: 0x20, object flags: 0x3) +access SID: S-1-1-0 +access type: AUDIT OBJECT +Permissions: + [Write All Properties] +------- (user) ACL (revision: 4, size: 1944, number of ACEs: 40) +------- ACE (type: 0x00, flags: 0x00, size: 0x24, mask: 0xf01ff) +access SID: S-1-5-21-4052121579-2079768045-1474639452-512 +access type: ALLOWED +Permissions: [Full Control] +------- ACE (type: 0x00, flags: 0x00, size: 0x18, mask: 0xf01ff) +access SID: S-1-5-32-548 +... +------- ACE (type: 0x05, flags: 0x12, size: 0x38, + mask: 0x10, object flags: 0x3) +access SID: S-1-5-9 +access type: ALLOWED OBJECT +Permissions: + [Read All Properties] +-------------- End Of Security Descriptor +</programlisting> + And now you have conclusive proof that your Samba-3 ADS domain member server + called <constant>FRAN</constant> is able to communicate fully with the ADS + domain controllers. + </para></step> + + </procedure> + + + <para> + Your Samba-3 ADS domain member server is ready for use. During training sessions, + you may be asked what is inside the <filename>winbindd_cache.tdb and winbindd_idmap.tdb</filename> + files. Since curiosity just took hold of you, execute the following: +<programlisting> +&rootprompt; tdbdump /var/lib/samba/winbindd_idmap.tdb +{ +key = "S-1-5-21-4052121579-2079768045-1474639452-501\00" +data = "UID 10001\00" +} +{ +key = "UID 10005\00" +data = "S-1-5-21-4052121579-2079768045-1474639452-1111\00" +} +{ +key = "GID 10004\00" +data = "S-1-5-21-4052121579-2079768045-1474639452-518\00" +} +{ +key = "S-1-5-21-4052121579-2079768045-1474639452-502\00" +data = "UID 10003\00" +} +... + +&rootprompt; tdbdump /var/lib/samba/winbindd_cache.tdb +{ +key = "UL/LONDON" +data = "\00\00\00\00bp\00\00\06\00\00\00\0DAdministrator\0D + Administrator-S-1-5-21-4052121579-2079768045-1474639452-500- + S-1-5-21-4052121579-2079768045-1474639452-513\05Guest\05 + Guest-S-1-5-21-4052121579-2079768045-1474639452-501- + S-1-5-21-4052121579-2079768045-1474639452-514\10 + SUPPORT_388945a0\10SUPPORT_388945a0. + S-1-5-21-4052121579-2079768045-1474639452-1001- + S-1-5-21-4052121579-2079768045-1474639452-513\06krbtgt\06 + krbtgt-S-1-5-21-4052121579-2079768045-1474639452-502- + S-1-5-21-4052121579-2079768045-1474639452-513\03jht\10 + John H. Terpstra.S-1-5-21-4052121579-2079768045-1474639452-1110- + S-1-5-21-4052121579-2079768045-1474639452-513" +} +{ +key = "GM/S-1-5-21-4052121579-2079768045-1474639452-512" +data = "\00\00\00\00bp\00\00\02\00\00\00. + S-1-5-21-4052121579-2079768045-1474639452-1110\03 + jht\01\00\00\00-S-1-5-21-4052121579-2079768045-1474639452-500\0D + Administrator\01\00\00\00" +} +{ +key = "SN/S-1-5-21-4052121579-2079768045-1474639452-513" +data = "\00\00\00\00xp\00\00\02\00\00\00\0CDomain Users" +} +{ +key = "GM/S-1-5-21-4052121579-2079768045-1474639452-518" +data = "\00\00\00\00bp\00\00\01\00\00\00- + S-1-5-21-4052121579-2079768045-1474639452-500\0D + Administrator\01\00\00\00" +} +{ +key = "SEQNUM/LONDON\00" +data = "xp\00\00C\92\F6?" +} +{ +key = "U/S-1-5-21-4052121579-2079768045-1474639452-1110" +data = "\00\00\00\00xp\00\00\03jht\10John H. Terpstra. + S-1-5-21-4052121579-2079768045-1474639452-1110- + S-1-5-21-4052121579-2079768045-1474639452-513" +} +{ +key = "NS/S-1-5-21-4052121579-2079768045-1474639452-502" +data = "\00\00\00\00bp\00\00- + S-1-5-21-4052121579-2079768045-1474639452-502" +} +{ +key = "SN/S-1-5-21-4052121579-2079768045-1474639452-1001" +data = "\00\00\00\00bp\00\00\01\00\00\00\10SUPPORT_388945a0" +} +{ +key = "SN/S-1-5-21-4052121579-2079768045-1474639452-500" +data = "\00\00\00\00bp\00\00\01\00\00\00\0DAdministrator" +} +{ +key = "U/S-1-5-21-4052121579-2079768045-1474639452-502" +data = "\00\00\00\00bp\00\00\06krbtgt\06krbtgt- + S-1-5-21-4052121579-2079768045-1474639452-502- + S-1-5-21-4052121579-2079768045-1474639452-513" +} +.... +</programlisting> + Now all is revealed. Your curiosity, as well as that of your team, has been put at ease. + May this server serve well all who happen upon it. + </para> + +<example id="ch9-adssdm"> +<title>Samba Domain Member &smb.conf; File for Active Directory Membership</title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="unix charset">LOCALE</smbconfoption> +<smbconfoption name="workgroup">LONDON</smbconfoption> +<smbconfoption name="realm">LONDON.ABMAS.BIZ</smbconfoption> +<smbconfoption name="server string">Samba 3.0.20</smbconfoption> +<smbconfoption name="security">ADS</smbconfoption> +<smbconfoption name="username map">/etc/samba/smbusers</smbconfoption> +<smbconfoption name="log level">1</smbconfoption> +<smbconfoption name="syslog">0</smbconfoption> +<smbconfoption name="log file">/var/log/samba/%m</smbconfoption> +<smbconfoption name="max log size">50</smbconfoption> +<smbconfoption name="printcap name">CUPS</smbconfoption> +<smbconfoption name="ldap ssl">no</smbconfoption> +<smbconfoption name="idmap uid">10000-20000</smbconfoption> +<smbconfoption name="idmap gid">10000-20000</smbconfoption> +<smbconfoption name="template primary group">"Domain Users"</smbconfoption> +<smbconfoption name="template shell">/bin/bash</smbconfoption> +<smbconfoption name="winbind separator">+</smbconfoption> +<smbconfoption name="printing">cups</smbconfoption> + +<smbconfsection name="[homes]"/> +<smbconfoption name="comment">Home Directories</smbconfoption> +<smbconfoption name="valid users">%S</smbconfoption> +<smbconfoption name="read only">No</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[printers]"/> +<smbconfoption name="comment">SMB Print Spool</smbconfoption> +<smbconfoption name="path">/var/spool/samba</smbconfoption> +<smbconfoption name="guest ok">Yes</smbconfoption> +<smbconfoption name="printable">Yes</smbconfoption> +<smbconfoption name="browseable">No</smbconfoption> + +<smbconfsection name="[print$]"/> +<smbconfoption name="comment">Printer Drivers</smbconfoption> +<smbconfoption name="path">/var/lib/samba/drivers</smbconfoption> +<smbconfoption name="admin users">root, Administrator</smbconfoption> +<smbconfoption name="write list">root</smbconfoption> +</smbconfblock> +</example> + + <sect3> + <title>IDMAP_RID with Winbind</title> + + <para> + <indexterm><primary>idmap_rid</primary></indexterm> + <indexterm><primary>SID</primary></indexterm> + <indexterm><primary>RID</primary></indexterm> + <indexterm><primary>IDMAP</primary></indexterm> + The <command>idmap_rid</command> facility is a new tool that, unlike native winbind, creates a + predictable mapping of MS Windows SIDs to UNIX UIDs and GIDs. The key benefit of this method + of implementing the Samba IDMAP facility is that it eliminates the need to store the IDMAP data + in a central place. The downside is that it can be used only within a single ADS domain and + is not compatible with trusted domain implementations. + </para> + + <para> + <indexterm><primary>SID</primary></indexterm> + <indexterm><primary>allow trusted domains</primary></indexterm> + <indexterm><primary>idmap uid</primary></indexterm> + <indexterm><primary>idmap gid</primary></indexterm> + This alternate method of SID to UID/GID mapping can be achieved with the idmap_rid + plug-in. This plug-in uses the RID of the user SID to derive the UID and GID by adding the + RID to a base value specified. This utility requires that the parameter + <quote>allow trusted domains = No</quote> must be specified, as it is not compatible + with multiple domain environments. The <parameter>idmap uid</parameter> and + <parameter>idmap gid</parameter> ranges must be specified. + </para> + + <para> + <indexterm><primary>idmap_rid</primary></indexterm> + <indexterm><primary>realm</primary></indexterm> + The idmap_rid facility can be used both for NT4/Samba-style domains as well as with Active Directory. + To use this with an NT4 domain, the <parameter>realm</parameter> is not used. Additionally the + method used to join the domain uses the <constant>net rpc join</constant> process. + </para> + + <para> + An example &smb.conf; file for an ADS domain environment is shown in <link linkend="sbe-idmapridex"/>. + </para> + +<example id="sbe-idmapridex"> +<title>Example &smb.conf; File Using <constant>idmap_rid</constant></title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="workgroup">KPAK</smbconfoption> +<smbconfoption name="netbios name">BIGJOE</smbconfoption> +<smbconfoption name="realm">CORP.KPAK.COM</smbconfoption> +<smbconfoption name="server string">Office Server</smbconfoption> +<smbconfoption name="security">ADS</smbconfoption> +<smbconfoption name="allow trusted domains">No</smbconfoption> +<smbconfoption name="idmap backend">idmap_rid:KPAK=500-100000000</smbconfoption> +<smbconfoption name="idmap uid">500-100000000</smbconfoption> +<smbconfoption name="idmap gid">500-100000000</smbconfoption> +<smbconfoption name="template shell">/bin/bash</smbconfoption> +<smbconfoption name="winbind use default domain">Yes</smbconfoption> +<smbconfoption name="winbind enum users">No</smbconfoption> +<smbconfoption name="winbind enum groups">No</smbconfoption> +<smbconfoption name="winbind nested groups">Yes</smbconfoption> +<smbconfoption name="printer admin">"KPAK\Domain Admins"</smbconfoption> +</smbconfblock> +</example> + + <para> + <indexterm><primary>large domain</primary></indexterm> + <indexterm><primary>Active Directory</primary></indexterm> + <indexterm><primary>response</primary></indexterm> + <indexterm><primary>getent</primary></indexterm> + In a large domain with many users, it is imperative to disable enumeration of users and groups. + For example, at a site that has 22,000 users in Active Directory the winbind-based user and + group resolution is unavailable for nearly 12 minutes following first start-up of + <command>winbind</command>. Disabling of such enumeration results in instantaneous response. + The disabling of user and group enumeration means that it will not be possible to list users + or groups using the <command>getent passwd</command> and <command>getent group</command> + commands. It will be possible to perform the lookup for individual users, as shown in the procedure + below. + </para> + + <para> + <indexterm><primary>NSS</primary></indexterm> + <indexterm><primary>/etc/nsswitch.conf</primary></indexterm> + The use of this tool requires configuration of NSS as per the native use of winbind. Edit the + <filename>/etc/nsswitch.conf</filename> so it has the following parameters: +<screen> +... +passwd: files winbind +shadow: files winbind +group: files winbind +... +hosts: files wins +... +</screen> + </para> + + <para> + The following procedure can be used to utilize the idmap_rid facility: + </para> + + <procedure> + <step><para> + Create or install and &smb.conf; file with the above configuration. + </para></step> + + <step><para> + Edit the <filename>/etc/nsswitch.conf</filename> file as shown above. + </para></step> + + <step><para> + Execute: +<screen> +&rootprompt; net ads join -UAdministrator%password +Using short domain name -- KPAK +Joined 'BIGJOE' to realm 'CORP.KPAK.COM' +</screen> + </para> + + <para> + <indexterm><primary>failed join</primary></indexterm> + An invalid or failed join can be detected by executing: +<screen> +&rootprompt; net ads testjoin +BIGJOE$@'s password: +[2004/11/05 16:53:03, 0] utils/net_ads.c:ads_startup(186) + ads_connect: No results returned +Join to domain is not valid +</screen> + The specific error message may differ from the above because it depends on the type of failure that + may have occurred. Increase the <parameter>log level</parameter> to 10, repeat the above test, + and then examine the log files produced to identify the nature of the failure. + </para></step> + + <step><para> + Start the <command>nmbd</command>, <command>winbind,</command> and <command>smbd</command> daemons in the order shown. + </para></step> + + <step><para> + Validate the operation of this configuration by executing: + <indexterm><primary></primary></indexterm> +<screen> +&rootprompt; getent passwd administrator +administrator:x:1000:1013:Administrator:/home/BE/administrator:/bin/bash +</screen> + </para></step> + </procedure> + + </sect3> + + <sect3> + <title>IDMAP Storage in LDAP using Winbind</title> + + <para> + <indexterm><primary>ADAM</primary></indexterm> + <indexterm><primary>ADS</primary></indexterm> + The storage of IDMAP information in LDAP can be used with both NT4/Samba-3-style domains as well as + with ADS domains. OpenLDAP is a commonly used LDAP server for this purpose, although any standards-compliant + LDAP server can be used. It is therefore possible to deploy this IDMAP configuration using + the Sun iPlanet LDAP server, Novell eDirectory, Microsoft ADS plus ADAM, and so on. + </para> + + <para> + The example in <link linkend="sbeunxa"/> is for an ADS-style domain. + </para> + +<example id="sbeunxa"> +<title>Typical ADS Style Domain &smb.conf; File</title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="workgroup">SNOWSHOW</smbconfoption> +<smbconfoption name="netbios name">GOODELF</smbconfoption> +<smbconfoption name="realm">SNOWSHOW.COM</smbconfoption> +<smbconfoption name="server string">Samba Server</smbconfoption> +<smbconfoption name="security">ADS</smbconfoption> +<smbconfoption name="log level">1 ads:10 auth:10 sam:10 rpc:10</smbconfoption> +<smbconfoption name="ldap admin dn">cn=Manager,dc=SNOWSHOW,dc=COM</smbconfoption> +<smbconfoption name="ldap idmap suffix">ou=Idmap</smbconfoption> +<smbconfoption name="ldap suffix">dc=SNOWSHOW,dc=COM</smbconfoption> +<smbconfoption name="idmap backend">ldap:ldap://ldap.snowshow.com</smbconfoption> +<smbconfoption name="idmap uid">150000-550000</smbconfoption> +<smbconfoption name="idmap gid">150000-550000</smbconfoption> +<smbconfoption name="template shell">/bin/bash</smbconfoption> +<smbconfoption name="winbind use default domain">Yes</smbconfoption> +</smbconfblock> +</example> + + <para> + <indexterm><primary>realm</primary></indexterm> + In the case of an NT4 or Samba-3-style domain the <parameter>realm</parameter> is not used, and the + command used to join the domain is <command>net rpc join</command>. The above example also demonstrates + advanced error reporting techniques that are documented in the chapter called "Reporting Bugs" in + <quote>The Official Samba-3 HOWTO and Reference Guide, Second Edition</quote> (TOSHARG2). + </para> + + <para> + <indexterm><primary>MIT kerberos</primary></indexterm> + <indexterm><primary>Heimdal kerberos</primary></indexterm> + <indexterm><primary>/etc/krb5.conf</primary></indexterm> + Where MIT kerberos is installed (version 1.3.4 or later), edit the <filename>/etc/krb5.conf</filename> + file so it has the following contents: +<screen> +[logging] + default = FILE:/var/log/krb5libs.log + kdc = FILE:/var/log/krb5kdc.log + admin_server = FILE:/var/log/kadmind.log + +[libdefaults] + default_realm = SNOWSHOW.COM + dns_lookup_realm = false + dns_lookup_kdc = true + +[appdefaults] + pam = { + debug = false + ticket_lifetime = 36000 + renew_lifetime = 36000 + forwardable = true + krb4_convert = false + } +</screen> + </para> + + <para> + Where Heimdal kerberos is installed, edit the <filename>/etc/krb5.conf</filename> + file so it is either empty (i.e., no contents) or it has the following contents: +<screen> +[libdefaults] + default_realm = SNOWSHOW.COM + clockskew = 300 + +[realms] + SNOWSHOW.COM = { + kdc = ADSDC.SHOWSHOW.COM + } + +[domain_realm] + .snowshow.com = SNOWSHOW.COM +</screen> + </para> + + <note><para> + Samba cannot use the Heimdal libraries if there is no <filename>/etc/krb5.conf</filename> file. + So long as there is an empty file, the Heimdal kerberos libraries will be usable. There is no + need to specify any settings because Samba, using the Heimdal libraries, can figure this out automatically. + </para></note> + <para> + Edit the NSS control file <filename>/etc/nsswitch.conf</filename> so it has the following entries: +<screen> +... +passwd: files ldap +shadow: files ldap +group: files ldap +... +hosts: files wins +... +</screen> + </para> + + <para> + <indexterm><primary>PADL</primary></indexterm> + <indexterm><primary>/etc/ldap.conf</primary></indexterm> + You will need the <ulink url="http://www.padl.com">PADL</ulink> <command>nss_ldap</command> + tool set for this solution. Configure the <filename>/etc/ldap.conf</filename> file so it has + the information needed. The following is an example of a working file: +<screen> +host 192.168.2.1 +base dc=snowshow,dc=com +binddn cn=Manager,dc=snowshow,dc=com +bindpw not24get + +pam_password exop + +nss_base_passwd ou=People,dc=snowshow,dc=com?one +nss_base_shadow ou=People,dc=snowshow,dc=com?one +nss_base_group ou=Groups,dc=snowshow,dc=com?one +ssl no +</screen> + </para> + + <para> + The following procedure may be followed to affect a working configuration: + </para> + <procedure> + <step><para> + Configure the &smb.conf; file as shown above. + </para></step> + + <step><para> + Create the <filename>/etc/krb5.conf</filename> file following the indications above. + </para></step> + + <step><para> + Configure the <filename>/etc/nsswitch.conf</filename> file as shown above. + </para></step> + + <step><para> + Download, build, and install the PADL nss_ldap tool set. Configure the + <filename>/etc/ldap.conf</filename> file as shown above. + </para></step> + + <step><para> + Configure an LDAP server and initialize the directory with the top-level entries needed by IDMAP + as shown in the following LDIF file: +<screen> +dn: dc=snowshow,dc=com +objectClass: dcObject +objectClass: organization +dc: snowshow +o: The Greatest Snow Show in Singapore. +description: Posix and Samba LDAP Identity Database + +dn: cn=Manager,dc=snowshow,dc=com +objectClass: organizationalRole +cn: Manager +description: Directory Manager + +dn: ou=Idmap,dc=snowshow,dc=com +objectClass: organizationalUnit +ou: idmap +</screen> + </para></step> + + <step><para> + Execute the command to join the Samba domain member server to the ADS domain as shown here: +<screen> +&rootprompt; net ads testjoin +Using short domain name -- SNOWSHOW +Joined 'GOODELF' to realm 'SNOWSHOW.COM' +</screen> + </para></step> + + <step><para> + Store the LDAP server access password in the Samba <filename>secrets.tdb</filename> file as follows: +<screen> +&rootprompt; smbpasswd -w not24get +</screen> + </para></step> + + <step><para> + Start the <command>nmbd</command>, <command>winbind</command>, and <command>smbd</command> daemons in the order shown. + </para></step> + </procedure> + + + <para> + <indexterm><primary>diagnostic</primary></indexterm> + Follow the diagnostic procedures shown earlier in this chapter to identify success or failure of the join. + In many cases a failure is indicated by a silent return to the command prompt with no indication of the + reason for failure. + </para> + + </sect3> + + <sect3> + <title>IDMAP and NSS Using LDAP from ADS with RFC2307bis Schema Extension</title> + + <para> + <indexterm><primary>rfc2307bis</primary></indexterm> + <indexterm><primary>schema</primary></indexterm> + The use of this method is messy. The information provided in this section is for guidance only + and is very definitely not complete. This method does work; it is used in a number of large sites + and has an acceptable level of performance. + </para> + + <para> + An example &smb.conf; file is shown in <link linkend="sbewinbindex"/>. + </para> + +<example id="sbewinbindex"> +<title>ADS Membership Using RFC2307bis Identity Resolution &smb.conf; File</title> +<smbconfblock> +<smbconfcomment>Global parameters</smbconfcomment> +<smbconfsection name="[global]"/> +<smbconfoption name="workgroup">BUBBAH</smbconfoption> +<smbconfoption name="netbios name">MADMAX</smbconfoption> +<smbconfoption name="realm">BUBBAH.COM</smbconfoption> +<smbconfoption name="server string">Samba Server</smbconfoption> +<smbconfoption name="security">ADS</smbconfoption> +<smbconfoption name="idmap uid">150000-550000</smbconfoption> +<smbconfoption name="idmap gid">150000-550000</smbconfoption> +<smbconfoption name="template shell">/bin/bash</smbconfoption> +<smbconfoption name="winbind use default domain">Yes</smbconfoption> +<smbconfoption name="winbind trusted domains only">Yes</smbconfoption> +<smbconfoption name="winbind nested groups">Yes</smbconfoption> +</smbconfblock> +</example> + + <para> + <indexterm><primary>nss_ldap</primary></indexterm> + The DMS must be joined to the domain using the usual procedure. Additionally, it is necessary + to build and install the PADL nss_ldap tool set. Be sure to build this tool set with the + following: +<screen> +./configure --enable-rfc2307bis --enable-schema-mapping +make install +</screen> + </para> + + <para> + <indexterm><primary>/etc/nsswitch.conf</primary></indexterm> + The following <filename>/etc/nsswitch.conf</filename> file contents are required: +<screen> +... +passwd: files ldap +shadow: files ldap +group: files ldap +... +hosts: files wins +... +</screen> + </para> + + <para> + <indexterm><primary>/etc/ldap.conf</primary></indexterm> + <indexterm><primary>nss_ldap</primary></indexterm> + The <filename>/etc/ldap.conf</filename> file must be configured also. Refer to the PADL documentation + and source code for nss_ldap instructions. + </para> + + <para> + The next step involves preparation on the ADS schema. This is briefly discussed in the remaining + part of this chapter. + </para> + + <sect4> + <title>IDMAP, Active Directory, and MS Services for UNIX 3.5</title> + + <para> + <indexterm><primary>SFU</primary></indexterm> + The Microsoft Windows Service for UNIX version 3.5 is available for free + <ulink url="http://www.microsoft.com/windows/sfu/">download</ulink> + from the Microsoft Web site. You will need to download this tool and install it following + Microsoft instructions. + </para> + + </sect4> + + <sect4> + <title>IDMAP, Active Directory, and AD4UNIX</title> + + <para> + Instructions for obtaining and installing the AD4UNIX tool set can be found from the + <ulink url="http://www.geekcomix.com/cgi-bin/classnotes/wiki.pl?LDAP01/An_Alternative_Approach"> + Geekcomix</ulink> Web site. + </para> + + </sect4> + + </sect3> + + </sect2> + + + <sect2> + <title>UNIX/Linux Client Domain Member</title> + + <para><indexterm> + <primary>user credentials</primary> + </indexterm> + So far this chapter has been mainly concerned with the provision of file and print + services for domain member servers. However, an increasing number of UNIX/Linux + workstations are being installed that do not act as file or print servers to anyone + other than a single desktop user. The key demand for desktop systems is to be able + to log onto any UNIX/Linux or Windows desktop using the same network user credentials. + </para> + + <para><indexterm> + <primary>Single Sign-On</primary> + <see>SSO</see> + </indexterm> + The ability to use a common set of user credential across a variety of network systems + is generally regarded as a single sign-on (SSO) solution. SSO systems are sold by a + large number of vendors and include a range of technologies such as: + </para> + + <itemizedlist> + <listitem><para> + Proxy sign-on + </para></listitem> + + <listitem><para> + Federated directory provisioning + </para></listitem> + + <listitem><para> + Metadirectory server solutions + </para></listitem> + + <listitem><para> + Replacement authentication systems + </para></listitem> + </itemizedlist> + + <para><indexterm> + <primary>Identity management</primary> + </indexterm> + There are really four solutions that provide integrated authentication and + user identity management facilities: + </para> + + <itemizedlist> + <listitem><para> + Samba winbind (free). Samba-3.0.20 introduced a complete replacement for Winbind that now + provides a greater level of scalability in large ADS environments. + </para></listitem> + + <listitem><para> + <ulink url="http://www.padl.com">PADL</ulink> PAM and LDAP tools (free). + </para></listitem> + + <listitem><para> + <ulink url="http://www.vintela.com">Vintela</ulink> Authentication Services (commercial). + </para></listitem> + + <listitem><para> + <ulink url="http://www.centrify.com">Centrify</ulink> DirectControl (commercial). + Centrify's commercial product allows UNIX and Linux systems to use Active Directory + security, directory and policy services. Enhancements include a centralized ID mapping that + allows Samba, DirectControl and Active Directory to seamlessly work together. + </para></listitem> + </itemizedlist> + + <para> + The following guidelines are pertinent to the deployment of winbind-based authentication + and identity resolution with the express purpose of allowing users to log on to UNIX/Linux desktops + using Windows network domain user credentials (username and password). + </para> + + <para> + You should note that it is possible to use LDAP-based PAM and NSS tools to permit distributed + systems logons (SSO), providing user and group accounts are stored in an LDAP directory. This + provides logon services for UNIX/Linux users, while Windows users obtain their sign-on + support via Samba-3. + </para> + + <para> + <indexterm><primary>Windows Services for UNIX</primary><see>SUS</see></indexterm> + On the other hand, if the authentication and identity resolution backend must be provided by + a Windows NT4-style domain or from an Active Directory Domain that does not have the Microsoft + Windows Services for UNIX installed, winbind is your best friend. Specific guidance for these + situations now follows. + </para> + + <para> + <indexterm><primary>PAM</primary></indexterm> + <indexterm><primary>Identity resolution</primary></indexterm> + <indexterm><primary>NSS</primary></indexterm> + To permit users to log on to a Linux system using Windows network credentials, you need to + configure identity resolution (NSS) and PAM. This means that the basic steps include those + outlined above with the addition of PAM configuration. Given that most workstations (desktop/client) + usually do not need to provide file and print services to a group of users, the configuration + of shares and printers is generally less important. Often this allows the share specifications + to be entirely removed from the &smb.conf; file. That is obviously an administrator decision. + </para> + + <sect3> + <title>NT4 Domain Member</title> + + <para> + The following steps provide a Linux system that users can log onto using + Windows NT4 (or Samba-3) domain network credentials: + </para> + + <procedure> + <step><para> + Follow the steps outlined in <link linkend="wdcsdm"/> and ensure that + all validation tests function as shown. + </para></step> + + <step><para> + Identify what services users must log on to. On Red Hat Linux, if it is + intended that the user shall be given access to all services, it may be + most expeditious to simply configure the file + <filename>/etc/pam.d/system-auth</filename>. + </para></step> + + <step><para> + Carefully make a backup copy of all PAM configuration files before you + begin making changes. If you break the PAM configuration, please note + that you may need to use an emergency boot process to recover your Linux + system. It is possible to break the ability to log into the system if + PAM files are incorrectly configured. The entire directory + <filename>/etc/pam.d</filename> should be backed up to a safe location. + </para></step> + + <step><para> + If you require only console login support, edit the <filename>/etc/pam.d/login</filename> + so it matches <link linkend="ch9-pamwnbdlogin"/>. + </para></step> + + <step><para> + To provide the ability to log onto the graphical desktop interface, you must edit + the files <filename>gdm</filename> and <filename>xdm</filename> in the + <filename>/etc/pam.d</filename> directory. + </para></step> + + <step><para> + Edit only one file at a time. Carefully validate its operation before attempting + to reboot the machine. + </para></step> + </procedure> + + </sect3> + + <sect3> + <title>ADS Domain Member</title> + + <para> + This procedure should be followed to permit a Linux network client (workstation/desktop) + to permit users to log on using Microsoft Active Directory-based user credentials. + </para> + + <procedure> + <step><para> + Follow the steps outlined in <link linkend="adssdm"/> and ensure that + all validation tests function as shown. + </para></step> + + <step><para> + Identify what services users must log on to. On Red Hat Linux, if it is + intended that the user shall be given access to all services, it may be + most expeditious to simply configure the file + <filename>/etc/pam.d/system-auth</filename> as shown in <link linkend="ch9-rhsysauth"/>. + </para></step> + + <step><para> + Carefully make a backup copy of all PAM configuration files before you + begin making changes. If you break the PAM configuration, please note + that you may need to use an emergency boot process to recover your Linux + system. It is possible to break the ability to log into the system if + PAM files are incorrectly configured. The entire directory + <filename>/etc/pam.d</filename> should be backed up to a safe location. + </para></step> + + <step><para> + If you require only console login support, edit the <filename>/etc/pam.d/login</filename> + so it matches <link linkend="ch9-pamwnbdlogin"/>. + </para></step> + + <step><para> + To provide the ability to log onto the graphical desktop interface, you must edit + the files <filename>gdm</filename> and <filename>xdm</filename> in the + <filename>/etc/pam.d</filename> directory. + </para></step> + + <step><para> + Edit only one file at a time. Carefully validate its operation before attempting + to reboot the machine. + </para></step> + </procedure> + + </sect3> + +<example id="ch9-pamwnbdlogin"> +<title>SUSE: PAM <filename>login</filename> Module Using Winbind</title> +<screen> +# /etc/pam.d/login + +#%PAM-1.0 +auth sufficient pam_unix2.so nullok +auth sufficient pam_winbind.so use_first_pass use_authtok +auth required pam_securetty.so +auth required pam_nologin.so +auth required pam_env.so +auth required pam_mail.so +account sufficient pam_unix2.so +account sufficient pam_winbind.so user_first_pass use_authtok +password required pam_pwcheck.so nullok +password sufficient pam_unix2.so nullok use_first_pass use_authtok +password sufficient pam_winbind.so use_first_pass use_authtok +session sufficient pam_unix2.so none +session sufficient pam_winbind.so use_first_pass use_authtok +session required pam_limits.so +</screen> +</example> + +<example id="ch9-pamwbndxdm"> +<title>SUSE: PAM <filename>xdm</filename> Module Using Winbind</title> +<screen> +# /etc/pam.d/gdm (/etc/pam.d/xdm) + +#%PAM-1.0 +auth sufficient pam_unix2.so nullok +auth sufficient pam_winbind.so use_first_pass use_authtok +account sufficient pam_unix2.so +account sufficient pam_winbind.so use_first_pass use_authtok +password sufficient pam_unix2.so +password sufficient pam_winbind.so use_first_pass use_authtok +session sufficient pam_unix2.so +session sufficient pam_winbind.so use_first_pass use_authtok +session required pam_dev perm.so +session required pam_resmgr.so +</screen> +</example> + +<example id="ch9-rhsysauth"> +<title>Red Hat 9: PAM System Authentication File: <filename>/etc/pam.d/system-auth</filename> Module Using Winbind</title> +<screen> +#%PAM-1.0 +auth required /lib/security/$ISA/pam_env.so +auth sufficient /lib/security/$ISA/pam_unix.so likeauth nullok +auth sufficient /lib/security/$ISA/pam_winbind.so use_first_pass +auth required /lib/security/$ISA/pam_deny.so + +account required /lib/security/$ISA/pam_unix.so +account sufficient /lib/security/$ISA/pam_winbind.so use_first_pass + +password required /lib/security/$ISA/pam_cracklib.so retry=3 type= +# Note: The above line is complete. There is nothing following the '=' +password sufficient /lib/security/$ISA/pam_unix.so \ + nullok use_authtok md5 shadow +password sufficient /lib/security/$ISA/pam_winbind.so use_first_pass +password required /lib/security/$ISA/pam_deny.so + +session required /lib/security/$ISA/pam_limits.so +session sufficient /lib/security/$ISA/pam_unix.so +session sufficient /lib/security/$ISA/pam_winbind.so use_first_pass +</screen> +</example> + + </sect2> + + <sect2> + <title>Key Points Learned</title> + + <para> + The addition of UNIX/Linux Samba servers and clients is a common requirement. In this chapter, you + learned how to integrate such servers so that the UID/GID mappings they use can be consistent + across all domain member servers. You also discovered how to implement the ability to use Samba + or Windows domain account credentials to log on to a UNIX/Linux client. + </para> + + <para> + The following are key points made in this chapter: + </para> + + <itemizedlist> + <listitem><para> + Domain controllers are always authoritative for the domain. + </para></listitem> + + <listitem><para> + Domain members may have local accounts and must be able to resolve the identity of + domain user accounts. Domain user account identity must map to a local UID/GID. That + local UID/GID can be stored in LDAP. This way, it is possible to share the IDMAP data + across all domain member machines. + </para></listitem> + + <listitem><para> + Resolution of user and group identities on domain member machines may be implemented + using direct LDAP services or using winbind. + </para></listitem> + + <listitem><para> + On NSS/PAM enabled UNIX/Linux systems, NSS is responsible for identity management + and PAM is responsible for authentication of logon credentials (username and password). + </para></listitem> + </itemizedlist> + + </sect2> + +</sect1> + +<sect1> + <title>Questions and Answers</title> + + <para> + The following questions were obtained from the mailing list and also from private discussions + with Windows network administrators. + </para> + + <qandaset defaultlabel="chap09qa" type="number"> + <qandaentry> + <question> + + <para> + We use NIS for all UNIX accounts. Why do we need winbind? + </para> + + </question> + <answer> + + <para> + <indexterm><primary>NIS</primary></indexterm> + <indexterm><primary>encrypted passwords</primary></indexterm> + <indexterm><primary>smbpasswd</primary></indexterm> + <indexterm><primary>tdbsam</primary></indexterm> + <indexterm><primary>passdb backend</primary></indexterm> + <indexterm><primary>Winbind</primary></indexterm> + You can use NIS for your UNIX accounts. NIS does not store the Windows encrypted + passwords that need to be stored in one of the acceptable passdb backends. + Your choice of backend is limited to <parameter>smbpasswd</parameter> or + <parameter>tdbsam</parameter>. Winbind is needed to handle the resolution of + SIDs from trusted domains to local UID/GID values. + </para> + + <para> + <indexterm><primary>winbind trusted domains only</primary></indexterm> + <indexterm><primary>getpwnam()</primary></indexterm> + On a domain member server, you effectively map Windows domain users to local users + that are in your NIS database by specifying the <parameter>winbind trusted domains + only</parameter>. This causes user and group account lookups to be routed via + the <command>getpwnam()</command> family of systems calls. On an NIS-enabled client, + this pushes the resolution of users and groups out through NIS. + </para> + + <para> + As a general rule, it is always a good idea to run winbind on all Samba servers. + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para> + Our IT management people do not like LDAP but are looking at Microsoft Active Directory. + Which is better?<indexterm> + <primary>Active Directory</primary> + </indexterm> + </para> + + </question> + <answer> + + <para><indexterm> + <primary>LDAP</primary> + <secondary>server</secondary> + </indexterm><indexterm> + <primary>Kerberos</primary> + </indexterm><indexterm> + <primary>schema</primary> + </indexterm> + Microsoft Active Directory is an LDAP server that is intricately tied to a Kerberos + infrastructure. Most IT managers who object to LDAP do so because + an LDAP server is most often supplied as a raw tool that needs to be configured and + for which the administrator must create the schema, create the administration tools, and + devise the backup and recovery facilities in a site-dependent manner. LDAP servers + in general are seen as a high-energy, high-risk facility. + </para> + + <para><indexterm> + <primary>management</primary> + </indexterm> + Microsoft Active Directory by comparison is easy to install and configure and + is supplied with all tools necessary to implement and manage the directory. For sites + that lack a lot of technical competence, Active Directory is a good choice. For sites + that have the technical competence to handle Active Directory well, LDAP is a good + alternative. The real issue is, What type of solution does + the site want? If management wants a choice to use an alternative, they may want to + consider the options. On the other hand, if management just wants a solution that works, + Microsoft Active Directory is a good solution. + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para> + We want to implement a Samba PDC, four Samba BDCs, and 10 Samba servers. Is it possible + to use NIS in place of LDAP? + </para> + + </question> + <answer> + + <para><indexterm> + <primary>NIS</primary> + </indexterm><indexterm> + <primary>LDAP</primary> + </indexterm><indexterm> + <primary>encrypted passwords</primary> + </indexterm><indexterm> + <primary>synchronized</primary> + </indexterm><indexterm> + <primary>secure account password</primary> + </indexterm><indexterm> + <primary>PDC</primary> + </indexterm><indexterm> + <primary>BDC</primary> + </indexterm> + Yes, it is possible to use NIS in place of LDAP, but there may be problems with keeping + the Windows (SMB) encrypted passwords database correctly synchronized across the entire + network. Workstations (Windows client machines) periodically change their domain + membership secure account password. How can you keep changes that are on remote BDCs + synchronized on the PDC? + </para> + + <para><indexterm> + <primary>centralized storage</primary> + </indexterm><indexterm> + <primary>management</primary> + </indexterm><indexterm> + <primary>network Identities</primary> + </indexterm> + LDAP is a more elegant solution because it permits centralized storage and management + of all network identities (user, group, and machine accounts) together with all information + Samba needs to provide to network clients and their users. + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para> + Are you suggesting that users should not log on to a domain member server? If so, why? + </para> + + </question> + <answer> + + <para><indexterm> + <primary>security</primary> + </indexterm><indexterm> + <primary>data</primary> + <secondary>integrity</secondary> + </indexterm><indexterm> + <primary>mapped drives</primary> + </indexterm> + Many UNIX administrators mock the model that the personal computer industry has adopted + as normative since the early days of Novell NetWare. The old + perception of the necessity to keep users off file and print servers was a result of + fears concerning the security and integrity of data. It was a simple and generally + effective measure to keep users away from servers, except through mapped drives. + </para> + + <para><indexterm> + <primary>user logins</primary> + </indexterm><indexterm> + <primary>risk</primary> + </indexterm><indexterm> + <primary>user errors</primary> + </indexterm><indexterm> + <primary>strategy</primary> + </indexterm><indexterm> + <primary>policy</primary> + </indexterm> + UNIX administrators are fully correct in asserting that UNIX servers and workstations + are identical in terms of the software that is installed. They correctly assert that + in a well-secured environment it is safe to store files on a system that has hundreds + of users. But all network administrators must factor into the decision to allow or + reject general user logins to a UNIX system that is principally a file and print + server the risk to operations through simple user errors. + Only then can one begin to appraise the best strategy and adopt a site-specific + policy that best protects the needs of users and of the organization alike. + </para> + + <para><indexterm> + <primary>system level logins</primary> + </indexterm> + From experience, it is my recommendation to keep general system-level logins to a + practical minimum and to eliminate them if possible. This should not be taken as a + hard rule, though. The better question is, what works best for the site? + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para><indexterm> + <primary>trusted domains</primary> + </indexterm><indexterm> + <primary>domain</primary> + <secondary>trusted</secondary> + </indexterm><indexterm> + <primary>winbind trusted domains only</primary> + </indexterm><indexterm> + <primary>domain members</primary> + </indexterm> + We want to ensure that only users from our own domain plus from trusted domains can use our + Samba servers. In the &smb.conf; file on all servers, we have enabled the <parameter>winbind + trusted domains only</parameter> parameter. We now find that users from trusted domains + cannot access our servers, and users from Windows clients that are not domain members + can also access our servers. Is this a Samba bug? + </para> + + </question> + <answer> + + <para><indexterm> + <primary>distributed</primary> + </indexterm><indexterm> + <primary>NIS</primary> + </indexterm><indexterm> + <primary>rsync</primary> + </indexterm><indexterm> + <primary>LDAP</primary> + </indexterm><indexterm> + <primary>winbindd</primary> + </indexterm><indexterm> + <primary>/etc/passwd</primary> + </indexterm> + The manual page for this <parameter>winbind trusted domains only</parameter> parameter says, + <quote>This parameter is designed to allow Samba servers that are members of a Samba-controlled + domain to use UNIX accounts distributed vi NIS, rsync, or LDAP as the UIDs for winbindd users + in the hosts primary domain. Therefore, the user <constant>SAMBA\user1</constant> would be + mapped to the account <constant>user1</constant> in <filename>/etc/passwd</filename> instead + of allocating a new UID for him or her.</quote> This clearly suggests that you are trying + to use this parameter inappropriately. + </para> + + <para><indexterm> + <primary>valid users</primary> + </indexterm> + A far better solution is to use the <parameter>valid users</parameter> by specifying + precisely the domain users and groups that should be permitted access to the shares. You could, + for example, set the following parameters: +<screen> +[demoshare] + path = /export/demodata + valid users = @"Domain Users", @"OTHERDOMAIN\Domain Users" +</screen> + </para> + + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para> + What are the benefits of using LDAP for my domain member servers? + </para> + + </question> + <answer> + + <para><indexterm> + <primary>LDAP</primary> + </indexterm><indexterm> + <primary>benefit</primary> + </indexterm><indexterm> + <primary>UID</primary> + </indexterm><indexterm> + <primary>GID</primary> + </indexterm><indexterm> + <primary>Domain Controllers</primary> + </indexterm><indexterm> + <primary>Domain Member servers</primary> + </indexterm><indexterm> + <primary>copy</primary> + </indexterm><indexterm> + <primary>replicate</primary> + </indexterm><indexterm> + <primary>identity</primary> + </indexterm> + The key benefit of using LDAP is that the UID of all users and the GID of all groups + are globally consistent on domain controllers as well as on domain member servers. + This means that it is possible to copy/replicate files across servers without + loss of identity. + </para> + + <para><indexterm> + <primary>Identity resolution</primary> + </indexterm><indexterm> + <primary>winbind</primary> + </indexterm><indexterm> + <primary>IDMAP backend</primary> + </indexterm><indexterm> + <primary>LDAP</primary> + </indexterm><indexterm> + <primary>Domain Controllers</primary> + </indexterm><indexterm> + <primary>Domain Member</primary> + <secondary>servers</secondary> + </indexterm><indexterm> + <primary>Posix</primary> + </indexterm><indexterm> + <primary>account information</primary> + </indexterm> + When use is made of account identity resolution via winbind, even when an IDMAP backend + is stored in LDAP, the UID/GID on domain member servers is consistent, but differs + from the ID that the user/group has on domain controllers. The winbind allocated UID/GID + that is stored in LDAP (or locally) will be in the numeric range specified in the <parameter> + idmap uid/gid</parameter> in the &smb.conf; file. On domain controllers, the UID/GID is + that of the POSIX value assigned in the LDAP directory as part of the POSIX account information. + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para> + Is proper DNS operation necessary for Samba-3 plus LDAP? If so, what must I put into + my DNS configuration? + </para> + + </question> + <answer> + + <para><indexterm> + <primary>DNS</primary> + <secondary>configuration</secondary> + </indexterm><indexterm> + <primary>DNS</primary> + <secondary>lookup</secondary> + </indexterm><indexterm> + <primary>hosts</primary> + </indexterm><indexterm> + <primary>/etc/nsswitch.conf</primary> + </indexterm><indexterm> + <primary>NSS</primary> + </indexterm><indexterm> + <primary>/etc/hosts</primary> + </indexterm><indexterm> + <primary>WINS</primary> + <secondary>lookup</secondary> + </indexterm> + Samba depends on correctly functioning resolution of hostnames to their IP address. Samba + makes no direct DNS lookup calls, but rather redirects all name-to-address calls via the + <command>getXXXbyXXX()</command> function calls. The configuration of the <constant>hosts</constant> + entry in the NSS <filename>/etc/nsswitch.conf</filename> file determines how the underlying + resolution process is implemented. If the <constant>hosts</constant> entry in your NSS + control file says: +<screen> +hosts: files dns wins +</screen> + this means that a hostname lookup first tries the <filename>/etc/hosts</filename>. + If this fails to resolve, it attempts a DNS lookup, and if that fails, it tries a + WINS lookup. + </para> + + <para><indexterm> + <primary>NetBIOS</primary> + </indexterm><indexterm> + <primary>TCP/IP</primary> + </indexterm><indexterm> + <primary>name resolution</primary> + </indexterm> + The addition of the WINS-based name lookup makes sense only if NetBIOS over TCP/IP has + been enabled on all Windows clients. Where NetBIOS over TCP/IP has been disabled, DNS + is the preferred name resolution technology. This usually makes most sense when Samba + is a client of an Active Directory domain, where NetBIOS use has been disabled. In this + case, the Windows 200x autoregisters all locator records it needs with its own DNS + server or servers. + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para> + Our Windows 2003 Server Active Directory domain runs with NetBIOS disabled. Can we + use Samba-3 with that configuration? + </para> + + </question> + <answer> + + <para> + Yes. + </para> + + </answer> + </qandaentry> + + <qandaentry> + <question> + + <para><indexterm> + <primary>net</primary> + <secondary>ads</secondary> + <tertiary>join</tertiary> + </indexterm><indexterm> + <primary>net</primary> + <secondary>rpc</secondary> + <tertiary>join</tertiary> + </indexterm> + When I tried to execute net ads join, I got no output. It did not work, so + I think that it failed. I then executed net rpc join and that worked fine. + That is okay, isn't it? + </para> + + </question> + <answer> + + <para><indexterm> + <primary>Kerberos</primary> + </indexterm><indexterm> + <primary>authentication</primary> + </indexterm> + No. This is not okay. It means that your Samba-3 client has joined the ADS domain as + a Windows NT4 client, and Samba-3 will not be using Kerberos-based authentication. + </para> + + </answer> + </qandaentry> + + </qandaset> + +</sect1> + +</chapter> |