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diff --git a/docs/Samba3-HOWTO/TOSHARG-Winbind.xml b/docs/Samba3-HOWTO/TOSHARG-Winbind.xml new file mode 100644 index 0000000000..eabdcf9a72 --- /dev/null +++ b/docs/Samba3-HOWTO/TOSHARG-Winbind.xml @@ -0,0 +1,1302 @@ +<?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="winbind"> + +<chapterinfo> + <author> + <firstname>Tim</firstname><surname>Potter</surname> + <affiliation> + <orgname>Samba Team</orgname> + <address><email>tpot@linuxcare.com.au</email></address> + </affiliation> + </author> + &author.tridge; + <author> + <firstname>Naag</firstname><surname>Mummaneni</surname> + <affiliation> + <address><email>getnag@rediffmail.com</email></address> + </affiliation> + <contrib>Notes for Solaris</contrib> + </author> + <author> + <firstname>John</firstname><surname>Trostel</surname> + <affiliation> + <orgname>SNAP</orgname> + <address><email>jtrostel@snapserver.com</email></address> + </affiliation> + </author> + + &author.jelmer; + &author.jht; + <pubdate>27 June 2002</pubdate> +</chapterinfo> + +<title>Winbind: Use of Domain Accounts</title> + +<sect1> + <title>Features and Benefits</title> + + <para> + Integration of UNIX and Microsoft Windows NT through a unified logon has + been considered a <quote>holy grail</quote> in heterogeneous computing environments for + a long time. + </para> + + <para> + There is one other facility without which UNIX and Microsoft Windows network + interoperability would suffer greatly. It is imperative that there be a + mechanism for sharing files across UNIX systems and to be able to assign + domain user and group ownerships with integrity. + </para> + + <para> + <emphasis>winbind</emphasis> is a component of the Samba suite of programs that + solves the unified logon problem. Winbind uses a UNIX implementation of Microsoft + RPC calls, Pluggable Authentication Modules, and the Name Service Switch to + allow Windows NT domain users to appear and operate as UNIX users on a UNIX + machine. This chapter describes the Winbind system, explaining the functionality + it provides, how it is configured, and how it works internally. + </para> + + <para> + Winbind provides three separate functions: + </para> + + <itemizedlist> + <listitem><para> + Authentication of user credentials (via PAM). This makes it possible to + log onto a UNIX/Linux system using user and group accounts from a Windows + NT4 (including a Samba domain) or an Active Directory domain. + </para></listitem> + + <listitem><para> + Identity resolution (via NSS). This is the default when winbind is not used. + </para></listitem> + + <listitem><para> + Winbind maintains a database called winbind_idmap.tdb in which it stores + mappings between UNIX UIDs / GIDs and NT SIDs. This mapping is used only + for users and groups that do not have a local UID/GID. It stored the UID/GID + allocated from the idmap uid/gid range that it has mapped to the NT SID. + If <parameter>idmap backend</parameter> has been specified as <constant>ldap:ldap://hostname[:389]</constant> + then instead of using a local mapping Winbind will obtain this information + from the LDAP database. + </para></listitem> + </itemizedlist> + + <note><para> + <indexterm><primary>winbindd</primary></indexterm> + <indexterm><primary>starting samba</primary><secondary>winbindd</secondary></indexterm> + If <command>winbindd</command> is not running, smbd (which calls <command>winbindd</command>) will fall back to + using purely local information from <filename>/etc/passwd</filename> and <filename>/etc/group</filename> and no dynamic + mapping will be used. On an operating system that has beeb enabled with the name service switcher (NSS) + the resoltion of user and group information will be accomplished via NSS. + </para></note> + + + <image id="winbind_idmap"> + <imagedescription>Winbind Idmap</imagedescription> + <imagefile scale="50">idmap_winbind_no_loop</imagefile> + </image> + +</sect1> + + +<sect1> + <title>Introduction</title> + + <para>It is well known that UNIX and Microsoft Windows NT have + different models for representing user and group information and + use different technologies for implementing them. This fact has + made it difficult to integrate the two systems in a satisfactory + manner.</para> + + <para>One common solution in use today has been to create + identically named user accounts on both the UNIX and Windows systems + and use the Samba suite of programs to provide file and print services + between the two. This solution is far from perfect, however, as + adding and deleting users on both sets of machines becomes a chore + and two sets of passwords are required &smbmdash; both of which + can lead to synchronization problems between the UNIX and Windows + systems and confusion for users.</para> + + <para>We divide the unified logon problem for UNIX machines into + three smaller problems:</para> + + <itemizedlist> + <listitem><para>Obtaining Windows NT user and group information. + </para></listitem> + + <listitem><para>Authenticating Windows NT users. + </para></listitem> + + <listitem><para>Password changing for Windows NT users. + </para></listitem> + </itemizedlist> + + + <para>Ideally, a prospective solution to the unified logon problem + would satisfy all the above components without duplication of + information on the UNIX machines and without creating additional + tasks for the system administrator when maintaining users and + groups on either system. The Winbind system provides a simple + and elegant solution to all three components of the unified logon + problem.</para> +</sect1> + + +<sect1> + <title>What Winbind Provides</title> + + <para>Winbind unifies UNIX and Windows NT account management by + allowing a UNIX box to become a full member of an NT domain. Once + this is done the UNIX box will see NT users and groups as if + they were <quote>native</quote> UNIX users and groups, allowing the NT domain + to be used in much the same manner that NIS+ is used within + UNIX-only environments.</para> + + <para>The end result is that whenever a + program on the UNIX machine asks the operating system to lookup + a user or group name, the query will be resolved by asking the + NT Domain Controller for the specified domain to do the lookup. + Because Winbind hooks into the operating system at a low level + (via the NSS name resolution modules in the C library), this + redirection to the NT Domain Controller is completely + transparent.</para> + + <para>Users on the UNIX machine can then use NT user and group + names as they would <quote>native</quote> UNIX names. They can chown files + so they are owned by NT domain users or even login to the + UNIX machine and run a UNIX X-Window session as a domain user.</para> + + <para>The only obvious indication that Winbind is being used is + that user and group names take the form <constant>DOMAIN\user</constant> and + <constant>DOMAIN\group</constant>. This is necessary as it allows Winbind to determine + that redirection to a Domain Controller is wanted for a particular + lookup and which trusted domain is being referenced.</para> + + <para>Additionally, Winbind provides an authentication service + that hooks into the Pluggable Authentication Modules (PAM) system + to provide authentication via an NT domain to any PAM-enabled + applications. This capability solves the problem of synchronizing + passwords between systems since all passwords are stored in a single + location (on the Domain Controller).</para> + + <sect2> + <title>Target Uses</title> + + <para>Winbind is targeted at organizations that have an + existing NT-based domain infrastructure into which they wish + to put UNIX workstations or servers. Winbind will allow these + organizations to deploy UNIX workstations without having to + maintain a separate account infrastructure. This greatly + simplifies the administrative overhead of deploying UNIX + workstations into an NT-based organization.</para> + + <para>Another interesting way in which we expect Winbind to + be used is as a central part of UNIX-based appliances. Appliances + that provide file and print services to Microsoft-based networks + will be able to use Winbind to provide seamless integration of + the appliance into the domain.</para> + </sect2> + + <sect2> + <title>Handling of Foreign SIDs</title> + + <para> + The term <emphasis>foreign SID</emphasis> is often met with the reaction that it + is not relevant to a particular environment. The following documents an interchange + that took place on the Samba mailing list. It is a good example of the confusion + often expressed regarding the use of winbind. + </para> + + <para> + Fact: Winbind is needed to handle users who use workstations that are NOT part + of the local domain. + </para> + + <para> + Response: <quote>Why? I've used samba with workstations that are not part of my domains + lots of times without using winbind. I though winbind was for using samba as a memberserver + in a domain controlled by another samba/windows PDC.</quote> + </para> + + <para> + If the Samba server will be accessed from a domain other than the local Samba domain, or + if there will be access from machines that are not local domain members, winbind will + permit the allocation of UIDs and GIDs from the assigned pool that will keep the identity + of the foreign user separate from users that are members of the Samba domain. + </para> + + <para> + Which means that that winbind is eminently useful in cases where one just has a single + Samba PDC on a local network combined of both domain member and non-domain member workstations. + If winbind is not used, the user george on an windows workstation that is not a domain + member will be able to access the files of a user called george in the account database + of the Samba server that is acting as a PDC. When winbind is used, the default condition + is that the local user george will be treated as the account DOMAIN\george and the + foreign (non-member of the domain) account will be treated as MACHINE\george because + each has a different SID. + </para> + + </sect2> +</sect1> + + + +<sect1> + <title>How Winbind Works</title> + + <para>The Winbind system is designed around a client/server + architecture. A long running <command>winbindd</command> daemon + listens on a UNIX domain socket waiting for requests + to arrive. These requests are generated by the NSS and PAM + clients and is processed sequentially.</para> + + <para>The technologies used to implement Winbind are described + in detail below.</para> + + <sect2> + <title>Microsoft Remote Procedure Calls</title> + + <para>Over the last few years, efforts have been underway + by various Samba Team members to decode various aspects of + the Microsoft Remote Procedure Call (MSRPC) system. This + system is used for most network-related operations between + Windows NT machines including remote management, user authentication + and print spooling. Although initially this work was done + to aid the implementation of Primary Domain Controller (PDC) + functionality in Samba, it has also yielded a body of code that + can be used for other purposes.</para> + + <para>Winbind uses various MSRPC calls to enumerate domain users + and groups and to obtain detailed information about individual + users or groups. Other MSRPC calls can be used to authenticate + NT domain users and to change user passwords. By directly querying + a Windows PDC for user and group information, Winbind maps the + NT account information onto UNIX user and group names.</para> + </sect2> + + <sect2> + <title>Microsoft Active Directory Services</title> + + <para> + Since late 2001, Samba has gained the ability to + interact with Microsoft Windows 2000 using its <quote>Native + Mode</quote> protocols, rather than the NT4 RPC services. + Using LDAP and Kerberos, a Domain Member running + Winbind can enumerate users and groups in exactly the + same way as a Windows 200x client would, and in so doing + provide a much more efficient and effective Winbind implementation. + </para> + </sect2> + + <sect2> + <title>Name Service Switch</title> + + <para>The Name Service Switch, or NSS, is a feature that is + present in many UNIX operating systems. It allows system + information such as hostnames, mail aliases and user information + to be resolved from different sources. For example, a standalone + UNIX workstation may resolve system information from a series of + flat files stored on the local filesystem. A networked workstation + may first attempt to resolve system information from local files, + and then consult an NIS database for user information or a DNS server + for hostname information.</para> + + <para>The NSS application programming interface allows Winbind + to present itself as a source of system information when + resolving UNIX usernames and groups. Winbind uses this interface, + and information obtained from a Windows NT server using MSRPC + calls to provide a new source of account enumeration. Using standard + UNIX library calls, one can enumerate the users and groups on + a UNIX machine running Winbind and see all users and groups in + a NT domain plus any trusted domain as though they were local + users and groups.</para> + + <para>The primary control file for NSS is + <filename>/etc/nsswitch.conf</filename>. + When a UNIX application makes a request to do a lookup, + the C library looks in <filename>/etc/nsswitch.conf</filename> + for a line that matches the service type being requested, for + example the <quote>passwd</quote> service type is used when user or group names + are looked up. This config line specifies which implementations + of that service should be tried and in what order. If the passwd + config line is:</para> + + <para><screen> + passwd: files example + </screen></para> + + <para>then the C library will first load a module called + <filename>/lib/libnss_files.so</filename> followed by + the module <filename>/lib/libnss_example.so</filename>. The + C library will dynamically load each of these modules in turn + and call resolver functions within the modules to try to resolve + the request. Once the request is resolved, the C library returns the + result to the application.</para> + + <para>This NSS interface provides an easy way for Winbind + to hook into the operating system. All that needs to be done + is to put <filename>libnss_winbind.so</filename> in <filename>/lib/</filename> + then add <quote>winbind</quote> into <filename>/etc/nsswitch.conf</filename> at + the appropriate place. The C library will then call Winbind to + resolve user and group names.</para> + </sect2> + + <sect2> + <title>Pluggable Authentication Modules</title> + + <para>Pluggable Authentication Modules, also known as PAM, + is a system for abstracting authentication and authorization + technologies. With a PAM module it is possible to specify different + authentication methods for different system applications without + having to recompile these applications. PAM is also useful + for implementing a particular policy for authorization. For example, + a system administrator may only allow console logins from users + stored in the local password file but only allow users resolved from + a NIS database to log in over the network.</para> + + <para>Winbind uses the authentication management and password + management PAM interface to integrate Windows NT users into a + UNIX system. This allows Windows NT users to log in to a UNIX + machine and be authenticated against a suitable Primary Domain + Controller. These users can also change their passwords and have + this change take effect directly on the Primary Domain Controller. + </para> + + <para>PAM is configured by providing control files in the directory + <filename>/etc/pam.d/</filename> for each of the services that + require authentication. When an authentication request is made + by an application, the PAM code in the C library looks up this + control file to determine what modules to load to do the + authentication check and in what order. This interface makes adding + a new authentication service for Winbind very easy. All that needs + to be done is that the <filename>pam_winbind.so</filename> module + is copied to <filename>/lib/security/</filename> and the PAM + control files for relevant services are updated to allow + authentication via Winbind. See the PAM documentation + in <link linkend="pam">PAM-Based Distributed Authentication</link> for more information.</para> + </sect2> + + + <sect2> + <title>User and Group ID Allocation</title> + + <para>When a user or group is created under Windows NT/200x + it is allocated a numerical relative identifier (RID). This is + slightly different from UNIX which has a range of numbers that are + used to identify users, and the same range in which to identify + groups. It is Winbind's job to convert RIDs to UNIX ID numbers and + vice versa. When Winbind is configured, it is given part of the UNIX + user ID space and a part of the UNIX group ID space in which to + store Windows NT users and groups. If a Windows NT user is + resolved for the first time, it is allocated the next UNIX ID from + the range. The same process applies for Windows NT groups. Over + time, Winbind will have mapped all Windows NT users and groups + to UNIX user IDs and group IDs.</para> + + <para>The results of this mapping are stored persistently in + an ID mapping database held in a tdb database). This ensures that + RIDs are mapped to UNIX IDs in a consistent way.</para> + </sect2> + + + <sect2> + <title>Result Caching</title> + + <para> +<indexterm><primary>SAM</primary></indexterm> + An active system can generate a lot of user and group + name lookups. To reduce the network cost of these lookups, Winbind + uses a caching scheme based on the SAM sequence number supplied + by NT Domain Controllers. User or group information returned + by a PDC is cached by Winbind along with a sequence number also + returned by the PDC. This sequence number is incremented by + Windows NT whenever any user or group information is modified. If + a cached entry has expired, the sequence number is requested from + the PDC and compared against the sequence number of the cached entry. + If the sequence numbers do not match, then the cached information + is discarded and up-to-date information is requested directly + from the PDC.</para> + </sect2> +</sect1> + + +<sect1> + <title>Installation and Configuration</title> + +<sect2> +<title>Introduction</title> + +<para> +This section describes the procedures used to get Winbind up and +running. Winbind is capable of providing access +and authentication control for Windows Domain users through an NT +or Windows 200x PDC for regular services, such as telnet and ftp, as +well for Samba services. +</para> + +<itemizedlist> +<listitem> + <para> + <emphasis>Why should I do this?</emphasis> + </para> + + <para>This allows the Samba administrator to rely on the + authentication mechanisms on the Windows NT/200x PDC for the authentication + of Domain Members. Windows NT/200x users no longer need to have separate + accounts on the Samba server. + </para> +</listitem> + +<listitem> + <para> + <emphasis>Who should be reading this document?</emphasis> + </para> + + <para> + This document is designed for system administrators. If you are + implementing Samba on a file server and wish to (fairly easily) + integrate existing Windows NT/200x users from your PDC onto the + Samba server, this document is for you. + </para> +</listitem> +</itemizedlist> +</sect2> + + +<sect2> +<title>Requirements</title> + +<para> +If you have a Samba configuration file that you are currently using, <emphasis>BACK IT UP!</emphasis> +If your system already uses PAM, <emphasis>back up the <filename>/etc/pam.d</filename> directory +contents!</emphasis> If you haven't already made a boot disk, <emphasis>MAKE ONE NOW!</emphasis> +</para> + +<para> +Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's +why you want to be able to boot back into your machine in single user mode and restore your +<filename>/etc/pam.d</filename> back to the original state they were in if you get frustrated with the +way things are going. +</para> + +<para> +The latest version of Samba-3 includes a functioning winbindd daemon. Please refer to the <ulink +url="http://samba.org/">main Samba Web page</ulink> or, better yet, your closest Samba mirror site for +instructions on downloading the source code. +</para> + +<para> +To allow domain users the ability to access Samba shares and files, as well as potentially other services +provided by your Samba machine, PAM must be set up properly on your +machine. In order to compile the Winbind modules, you should have at least the PAM development libraries installed +on your system. Please refer the PAM web site <ulink url="http://www.kernel.org/pub/linux/libs/pam/"/>. +</para> +</sect2> + +<sect2> +<title>Testing Things Out</title> + +<para> +Before starting, it is probably best to kill off all the Samba-related daemons running on your server. +Kill off all &smbd;, &nmbd;, and &winbindd; processes that may be running. To use PAM, +make sure that you have the standard PAM package that supplies the <filename>/etc/pam.d</filename> +directory structure, including the PAM modules that are used by PAM-aware services, several pam libraries, +and the <filename>/usr/doc</filename> and <filename>/usr/man</filename> entries for pam. Winbind built +better in Samba if the pam-devel package is also installed. This package includes the header files +needed to compile PAM-aware applications. +</para> + +<sect3> +<title>Configure <filename>nsswitch.conf</filename> and the Winbind Libraries on Linux and Solaris</title> + +<para> +PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install +the <filename>pam-devel</filename> libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3 +may auto-install the Winbind files into their correct locations on your system, so before you get too far down +the track be sure to check if the following configuration is really +necessary. You may only need to configure +<filename>/etc/nsswitch.conf</filename>. +</para> + +<para> +The libraries needed to run the &winbindd; daemon through nsswitch need to be copied to their proper locations: +</para> + +<para> +<screen> +&rootprompt;<userinput>cp ../samba/source/nsswitch/libnss_winbind.so /lib</userinput> +</screen> +</para> + +<para> +I also found it necessary to make the following symbolic link: +ZZ</para> + +<para> +&rootprompt; <userinput>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</userinput> +</para> + +<para>And, in the case of Sun Solaris:</para> +<screen> +&rootprompt;<userinput>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1</userinput> +&rootprompt;<userinput>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1</userinput> +&rootprompt;<userinput>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</userinput> +</screen> + +<para> +Now, as root you need to edit <filename>/etc/nsswitch.conf</filename> to +allow user and group entries to be visible from the &winbindd; +daemon. My <filename>/etc/nsswitch.conf</filename> file look like +this after editing: +</para> + +<para><programlisting> + passwd: files winbind + shadow: files + group: files winbind +</programlisting></para> + +<para> +The libraries needed by the <command>winbindd</command> daemon will be automatically +entered into the <command>ldconfig</command> cache the next time +your system reboots, but it is faster (and you do not need to reboot) if you do it manually: +</para> + +<para> +&rootprompt;<userinput>/sbin/ldconfig -v | grep winbind</userinput> +</para> + +<para> +This makes <filename>libnss_winbind</filename> available to winbindd +and echos back a check to you. +</para> + +</sect3> + +<sect3> +<title>NSS Winbind on AIX</title> + +<para>(This section is only for those running AIX.)</para> + +<para> +The Winbind AIX identification module gets built as <filename>libnss_winbind.so</filename> in the +nsswitch directory of the Samba source. This file can be copied to <filename>/usr/lib/security</filename>, +and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following: +</para> + +<para><programlisting> +WINBIND: + program = /usr/lib/security/WINBIND + options = authonly +</programlisting></para> + +<para> +can then be added to <filename>/usr/lib/security/methods.cfg</filename>. This module only supports +identification, but there have been success reports using the standard Winbind PAM module for +authentication. Use caution configuring loadable authentication +modules since you can make +it impossible to logon to the system. More information about the AIX authentication module API can +be found at <quote>Kernel Extensions and Device Support Programming Concepts for AIX</quote><ulink +url="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixprggd/kernextc/sec_load_mod.htm"> +in Chapter 18(John, there is no section like this in 18). Loadable Authentication Module Programming +Interface</ulink> and more information on administering the modules +can be found at <ulink +url="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixbman/baseadmn/iandaadmin.htm"> <quote>System +Management Guide: Operating System and Devices.</quote></ulink> +</para> +</sect3> + +<sect3> +<title>Configure smb.conf</title> + +<para> +Several parameters are needed in the &smb.conf; file to control the behavior of &winbindd;. These +are described in more detail in the <citerefentry><refentrytitle>winbindd</refentrytitle> +<manvolnum>8</manvolnum></citerefentry> man page. My &smb.conf; file, as shown in <link +linkend="winbindcfg">the next example</link>, was modified to include the necessary entries in the [global] section. +</para> + +<para> +<smbconfexample id="winbindcfg" fragment="1"> + <title>smb.conf for Winbind set-up</title> +<smbconfsection name="[global]"/> +<smbconfcomment> separate domain and username with '\', like DOMAIN\username</smbconfcomment> +<smbconfoption name="winbind separator">\</smbconfoption> +<smbconfcomment> use uids from 10000 to 20000 for domain users</smbconfcomment> +<smbconfoption name="idmap uid">10000-20000</smbconfoption> +<smbconfcomment> use gids from 10000 to 20000 for domain groups</smbconfcomment> +<smbconfoption name="idmap gid">10000-20000</smbconfoption> +<smbconfcomment> allow enumeration of winbind users and groups</smbconfcomment> +<smbconfoption name="winbind enum users">yes</smbconfoption> +<smbconfoption name="winbind enum groups">yes</smbconfoption> +<smbconfcomment> give winbind users a real shell (only needed if they have telnet access)</smbconfcomment> +<smbconfoption name="template homedir">/home/winnt/%D/%U</smbconfoption> +<smbconfoption name="template shell">/bin/bash</smbconfoption> +</smbconfexample></para> + +</sect3> + + +<sect3> +<title>Join the Samba Server to the PDC Domain</title> + +<para> +All machines that will participate in domain security should be members of +the domain. This applies also to the PDC and all BDCs. +</para> + +<para> +The process of joining a domain requires the use of the <command>net rpc join</command> +command. This process communicates with the domain controller it will register with +(usually the PDC) via MS DCE RPC. This means, of course, that the <command>smbd</command> +process must be running on the target DC. This means that it is necessary to temporarily +start Samba on a PDC so that it can join its own domain. +</para> + +<para> +Enter the following command to make the Samba server join the +domain, where <replaceable>PDC</replaceable> is the name of +your PDC and <replaceable>Administrator</replaceable> is +a domain user who has administrative privileges in the domain. +</para> + +<note><para> +Before attempting to join a machine to the domain verify that Samba is running +on the target DC (usually PDC) and that it is capable of being reached via ports +137/udp, 135/tcp, 139/tcp, and 445/tcp (if Samba or Windows Server 2Kx. +</para></note> + +<para> +&rootprompt;<userinput>/usr/local/samba/bin/net rpc join -S PDC -U Administrator</userinput> +</para> + +<para> +The proper response to the command should be: <quote>Joined the domain +<replaceable>DOMAIN</replaceable></quote> where <replaceable>DOMAIN</replaceable> +is your DOMAIN name. +</para> + +</sect3> + +<sect3> +<title>Starting and Testing the <command>winbindd</command> Daemon</title> + +<para> +Eventually, you will want to modify your Samba startup script to +automatically invoke the winbindd daemon when the other parts of +Samba start, but it is possible to test out just the Winbind +portion first. To start up Winbind services, enter the following +command as root: +</para> + +<para> +&rootprompt;<userinput>/usr/local/samba/sbin/winbindd</userinput> +</para> + +<note><para> +The above assumes that Samba has been installed in the <filename>/usr/local/samba</filename> +directory tree. You may need to search for the location of Samba files if this is not the +location of <command>winbindd</command> on your system. +</para></note> + +<para> +Winbindd can now also run in <quote>dual daemon mode</quote>. This will make it +run as two processes. The first will answer all requests from the cache, +thus making responses to clients faster. The other will +update the cache for the query that the first has just responded. +The advantage of this is that responses stay accurate and are faster. +You can enable dual daemon mode by adding <option>-B</option> to the command-line: +</para> + +<para> +&rootprompt;<userinput>/usr/local/samba/sbin/winbindd -B</userinput> +</para> + +<para> +I'm always paranoid and like to make sure the daemon is really running. +</para> + +<para> +&rootprompt;<userinput>ps -ae | grep winbindd</userinput> +</para> +<para> +This command should produce output like this, if the daemon is running you would expect +to see a report something like this: +</para> +<screen> +3025 ? 00:00:00 winbindd +</screen> + +<para> +Now, for the real test, try to get some information about the users on your PDC: +</para> + +<para> +&rootprompt;<userinput>/usr/local/samba/bin/wbinfo -u</userinput> +</para> + +<para> +This should echo back a list of users on your Windows users on +your PDC. For example, I get the following response: +</para> + +<para><screen> + CEO\Administrator + CEO\burdell + CEO\Guest + CEO\jt-ad + CEO\krbtgt + CEO\TsInternetUser +</screen></para> + +<para> +Obviously, I have named my domain <quote>CEO</quote> and my <smbconfoption name="winbind separator"/> is <quote>\</quote>. +</para> + +<para> +You can do the same sort of thing to get group information from the PDC: +</para> + +<para><screen> +&rootprompt;<userinput>/usr/local/samba/bin/wbinfo -g</userinput> + CEO\Domain Admins + CEO\Domain Users + CEO\Domain Guests + CEO\Domain Computers + CEO\Domain Controllers + CEO\Cert Publishers + CEO\Schema Admins + CEO\Enterprise Admins + CEO\Group Policy Creator Owners +</screen></para> + +<para> +The function <command>getent</command> can now be used to get unified +lists of both local and PDC users and groups. Try the following command: +</para> + +<para> +&rootprompt;<userinput>getent passwd</userinput> +</para> + +<para> +You should get a list that looks like your <filename>/etc/passwd</filename> +list followed by the domain users with their new UIDs, GIDs, home +directories and default shells. +</para> + +<para> +The same thing can be done for groups with the command: +</para> + +<para> +&rootprompt;<userinput>getent group</userinput> +</para> + +</sect3> + + +<sect3> +<title>Fix the init.d Startup Scripts</title> + +<sect4> +<title>Linux</title> + +<para> +The &winbindd; daemon needs to start up after the &smbd; and &nmbd; daemons are running. +To accomplish this task, you need to modify the startup scripts of your system. +They are located at <filename>/etc/init.d/smb</filename> in Red Hat Linux and they are located in +<filename>/etc/init.d/samba</filename> in Debian Linux. Edit your +script to add commands to invoke this daemon in the proper sequence. My +startup script starts up &smbd;, &nmbd;, and &winbindd; from the +<filename>/usr/local/samba/bin</filename> directory directly. The <command>start</command> +function in the script looks like this: +</para> + +<para><programlisting> +start() { + KIND="SMB" + echo -n $"Starting $KIND services: " + daemon /usr/local/samba/bin/smbd $SMBDOPTIONS + RETVAL=$? + echo + KIND="NMB" + echo -n $"Starting $KIND services: " + daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS + RETVAL2=$? + echo + KIND="Winbind" + echo -n $"Starting $KIND services: " + daemon /usr/local/samba/sbin/winbindd + RETVAL3=$? + echo + [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \ + touch /var/lock/subsys/smb || RETVAL=1 + return $RETVAL +} +</programlisting></para> + +<para>If you would like to run winbindd in dual daemon mode, replace +the line : +<programlisting> + daemon /usr/local/samba/sbin/winbindd +</programlisting> + +in the example above with: + +<programlisting> + daemon /usr/local/samba/sbin/winbindd -B +</programlisting>. +</para> + +<para> +The <command>stop</command> function has a corresponding entry to shut down the +services and looks like this: +</para> + +<para><programlisting> +stop() { + KIND="SMB" + echo -n $"Shutting down $KIND services: " + killproc smbd + RETVAL=$? + echo + KIND="NMB" + echo -n $"Shutting down $KIND services: " + killproc nmbd + RETVAL2=$? + echo + KIND="Winbind" + echo -n $"Shutting down $KIND services: " + killproc winbindd + RETVAL3=$? + [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \ + rm -f /var/lock/subsys/smb + echo "" + return $RETVAL +} +</programlisting></para> +</sect4> + +<sect4> +<title>Solaris</title> + +<para> +Winbind does not work on Solaris 9, see <link linkend="winbind-solaris9">Winbind on Solaris 9</link> section for details. +</para> + +<para> +On Solaris, you need to modify the <filename>/etc/init.d/samba.server</filename> startup script. It +usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in +<filename>/usr/local/samba/bin</filename>, the file could contains something like this: +</para> + +<para> + <smbfile name="samba.server.sh"> + <programlisting> + ## + ## samba.server + ## + + if [ ! -d /usr/bin ] + then # /usr not mounted + exit + fi + + killproc() { # kill the named process(es) + pid=`/usr/bin/ps -e | + /usr/bin/grep -w $1 | + /usr/bin/sed -e 's/^ *//' -e 's/ .*//'` + [ "$pid" != "" ] && kill $pid + } + + # Start/stop processes required for Samba server + + case "$1" in + + 'start') + # + # Edit these lines to suit your installation (paths, workgroup, host) + # + echo Starting SMBD + /usr/local/samba/bin/smbd -D -s \ + /usr/local/samba/smb.conf + + echo Starting NMBD + /usr/local/samba/bin/nmbd -D -l \ + /usr/local/samba/var/log -s /usr/local/samba/smb.conf + + echo Starting Winbind Daemon + /usr/local/samba/sbin/winbindd + ;; + + 'stop') + killproc nmbd + killproc smbd + killproc winbindd + ;; + + *) + echo "Usage: /etc/init.d/samba.server { start | stop }" + ;; + esac +</programlisting></smbfile></para> + +<para> +Again, if you would like to run Samba in dual daemon mode, replace: +<programlisting> + /usr/local/samba/sbin/winbindd +</programlisting> +in the script above with: +<programlisting> + /usr/local/samba/sbin/winbindd -B +</programlisting> +</para> + +</sect4> + +<sect4> +<title>Restarting</title> +<para> +If you restart the &smbd;, &nmbd;, and &winbindd; daemons at this point, you +should be able to connect to the Samba server as a Domain Member just as +if you were a local user. +</para> +</sect4> +</sect3> + +<sect3> +<title>Configure Winbind and PAM</title> + +<para> +If you have made it this far, you know that <command>winbindd</command> and Samba are working +together. If you want to use Winbind to provide authentication for other +services, keep reading. The PAM configuration files need to be altered in +this step. (Did you remember to make backups of your original +<filename>/etc/pam.d</filename> files? If not, do it now.) +</para> + +<para> +You will need a PAM module to use winbindd with these other services. This +module will be compiled in the <filename>../source/nsswitch</filename> directory +by invoking the command: +</para> + +<para> +&rootprompt;<userinput>make nsswitch/pam_winbind.so</userinput> +</para> + +<para> +from the <filename>../source</filename> directory. The +<filename>pam_winbind.so</filename> file should be copied to the location of +your other PAM security modules. On my Red Hat system, this was the +<filename>/lib/security</filename> directory. On Solaris, the PAM security +modules reside in <filename>/usr/lib/security</filename>. +</para> + +<para> +&rootprompt;<userinput>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</userinput> +</para> + +<sect4> +<title>Linux/FreeBSD-specific PAM configuration</title> + +<para> +The <filename>/etc/pam.d/samba</filename> file does not need to be changed. I +just left this file as it was: +</para> + + +<para><programlisting> + auth required /lib/security/pam_stack.so service=system-auth + account required /lib/security/pam_stack.so service=system-auth +</programlisting></para> + +<para> +The other services that I modified to allow the use of Winbind +as an authentication service were the normal login on the console (or a terminal +session), telnet logins, and ftp service. In order to enable these +services, you may first need to change the entries in +<filename>/etc/xinetd.d</filename> (or <filename>/etc/inetd.conf</filename>). +Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this case you need +to change the lines in <filename>/etc/xinetd.d/telnet</filename> +and <filename>/etc/xinetd.d/wu-ftp</filename> from +</para> + +<para><programlisting> + enable = no +</programlisting> +to: +<programlisting> + enable = yes +</programlisting></para> + +<para> +For ftp services to work properly, you will also need to either +have individual directories for the domain users already present on +the server, or change the home directory template to a general +directory for all domain users. These can be easily set using +the &smb.conf; global entry +<smbconfoption name="template homedir"/>. +</para> + +<note> + <para>The directory in <smbconfoption name="template homedir"/> is not created automatically! Use pam_mkhomedir or pre-create + the directories of users to make sure users can log in on UNIX with + their own home directory. + </para> +</note> + +<para> +The <filename>/etc/pam.d/ftp</filename> file can be changed +to allow Winbind ftp access in a manner similar to the +samba file. My <filename>/etc/pam.d/ftp</filename> file was +changed to look like this: +</para> + +<para><smbfile name="pam.ftp.winbind"><programlisting> +auth required /lib/security/pam_listfile.so item=user sense=deny \ + file=/etc/ftpusers onerr=succeed +auth sufficient /lib/security/pam_winbind.so +auth required /lib/security/pam_stack.so service=system-auth +auth required /lib/security/pam_shells.so +account sufficient /lib/security/pam_winbind.so +account required /lib/security/pam_stack.so service=system-auth +session required /lib/security/pam_stack.so service=system-auth +</programlisting></smbfile></para> + +<para> +The <filename>/etc/pam.d/login</filename> file can be changed nearly the +same way. It now looks like this: +</para> + +<para><smbfile name="pam.login.winbind"><programlisting> +auth required /lib/security/pam_securetty.so +auth sufficient /lib/security/pam_winbind.so +auth sufficient /lib/security/pam_unix.so use_first_pass +auth required /lib/security/pam_stack.so service=system-auth +auth required /lib/security/pam_nologin.so +account sufficient /lib/security/pam_winbind.so +account required /lib/security/pam_stack.so service=system-auth +password required /lib/security/pam_stack.so service=system-auth +session required /lib/security/pam_stack.so service=system-auth +session optional /lib/security/pam_console.so +</programlisting></smbfile></para> + +<para> +In this case, I added the <programlisting>auth sufficient /lib/security/pam_winbind.so</programlisting> +lines as before, but also added the <programlisting>required pam_securetty.so</programlisting> +above it, to disallow root logins over the network. I also added a +<programlisting>sufficient /lib/security/pam_unix.so use_first_pass</programlisting> +line after the <command>winbind.so</command> line to get rid of annoying +double prompts for passwords. +</para> + +</sect4> + +<sect4> +<title>Solaris-specific configuration</title> + +<para> +The <filename>/etc/pam.conf</filename> needs to be changed. I changed this file so my Domain +users can logon both locally as well as telnet. The following are the changes +that I made. You can customize the <filename>pam.conf</filename> file as per your requirements, but +be sure of those changes because in the worst case it will leave your system +nearly impossible to boot. +</para> + +<para><programlisting> +# +#ident "@(#)pam.conf 1.14 99/09/16 SMI" +# +# Copyright (c) 1996-1999, Sun Microsystems, Inc. +# All Rights Reserved. +# +# PAM configuration +# +# Authentication management +# +login auth required /usr/lib/security/pam_winbind.so +login auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass +login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass +# +rlogin auth sufficient /usr/lib/security/pam_winbind.so +rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1 +rlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass +# +dtlogin auth sufficient /usr/lib/security/pam_winbind.so +dtlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass +# +rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1 +other auth sufficient /usr/lib/security/pam_winbind.so +other auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass +# +# Account management +# +login account sufficient /usr/lib/security/pam_winbind.so +login account requisite /usr/lib/security/$ISA/pam_roles.so.1 +login account required /usr/lib/security/$ISA/pam_unix.so.1 +# +dtlogin account sufficient /usr/lib/security/pam_winbind.so +dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1 +dtlogin account required /usr/lib/security/$ISA/pam_unix.so.1 +# +other account sufficient /usr/lib/security/pam_winbind.so +other account requisite /usr/lib/security/$ISA/pam_roles.so.1 +other account required /usr/lib/security/$ISA/pam_unix.so.1 +# +# Session management +# +other session required /usr/lib/security/$ISA/pam_unix.so.1 +# +# Password management +# +#other password sufficient /usr/lib/security/pam_winbind.so +other password required /usr/lib/security/$ISA/pam_unix.so.1 +dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1 +# +# Support for Kerberos V5 authentication (uncomment to use Kerberos) +# +#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1 +#other account optional /usr/lib/security/$ISA/pam_krb5.so.1 +#other session optional /usr/lib/security/$ISA/pam_krb5.so.1 +#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass +</programlisting></para> + +<para> +I also added a <parameter>try_first_pass</parameter> line after the <filename>winbind.so</filename> +line to get rid of annoying double prompts for passwords. +</para> + +<para> +Now restart your Samba and try connecting through your application that you +configured in the pam.conf. +</para> + +</sect4> + +</sect3> + +</sect2> + +</sect1> + +<sect1> +<title>Conclusion</title> + +<para>The Winbind system, through the use of the Name Service +Switch, Pluggable Authentication Modules, and appropriate +Microsoft RPC calls have allowed us to provide seamless +integration of Microsoft Windows NT domain users on a +UNIX system. The result is a great reduction in the administrative +cost of running a mixed UNIX and NT network.</para> + +</sect1> + +<sect1> +<title>Common Errors</title> + + <para>Winbind has a number of limitations in its current + released version that we hope to overcome in future + releases:</para> + + <itemizedlist> + <listitem><para>Winbind is currently only available for + the Linux, Solaris, AIX, and IRIX operating systems, although ports to other operating + systems are certainly possible. For such ports to be feasible, + we require the C library of the target operating system to + support the Name Service Switch and Pluggable Authentication + Modules systems. This is becoming more common as NSS and + PAM gain support among UNIX vendors.</para></listitem> + + <listitem><para>The mappings of Windows NT RIDs to UNIX IDs + is not made algorithmically and depends on the order in which + unmapped users or groups are seen by Winbind. It may be difficult + to recover the mappings of RID to UNIX ID mapping if the file + containing this information is corrupted or destroyed.</para> + </listitem> + + <listitem><para>Currently the Winbind PAM module does not take + into account possible workstation and logon time restrictions + that may be set for Windows NT users, this is + instead up to the PDC to enforce.</para></listitem> + </itemizedlist> + + <sect2> + <title>NSCD Problem Warning</title> + + <?latex \nopagebreak ?> + + <warning><para> + Do not under any circumstances run <command>nscd</command> on any system + on which <command>winbindd</command> is running. + </para></warning> + + <para> + If <command>nscd</command> is running on the UNIX/Linux system, then + even though NSSWITCH is correctly configured it will not be possible to resolve + domain users and groups for file and directory controls. + </para> + + </sect2> + + <sect2> + <title>Winbind Is Not Resolving Users and Groups</title> + + <para><quote> + My &smb.conf; file is correctly configured. I have specified + <smbconfoption name="idmap uid">12000</smbconfoption>, + and <smbconfoption name="idmap gid">3000-3500</smbconfoption> + and <command>winbind</command> is running. When I do the following it all works fine. + </quote></para> + +<para><screen> +&rootprompt;<userinput>wbinfo -u</userinput> +MIDEARTH\maryo +MIDEARTH\jackb +MIDEARTH\ameds +... +MIDEARTH\root + +&rootprompt;<userinput>wbinfo -g</userinput> +MIDEARTH\Domain Users +MIDEARTH\Domain Admins +MIDEARTH\Domain Guests +... +MIDEARTH\Accounts + +&rootprompt;<userinput>getent passwd</userinput> +root:x:0:0:root:/root:/bin/bash +bin:x:1:1:bin:/bin:/bin/bash +... +maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false +</screen></para> + +<para><quote> +But the following command just fails: +</quote> +<screen> +&rootprompt;<userinput>chown maryo a_file</userinput> +chown: `maryo': invalid user +</screen> +<quote> +This is driving me nuts! What can be wrong? +</quote></para> + +<para> +Same problem as the one above. +Your system is likely running <command>nscd</command>, the name service +caching daemon. Shut it down, do not restart it! You will find your problem resolved. +</para> + +</sect2> +</sect1> + +</chapter> |