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1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 24. Winbind: Use of Domain Accounts</title><link rel="stylesheet" href="../samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"><link rel="home" href="index.html" title="The Official Samba 3.5.x HOWTO and Reference Guide"><link rel="up" href="optional.html" title="Part III. Advanced Configuration"><link rel="prev" href="VFS.html" title="Chapter 23. Stackable VFS modules"><link rel="next" href="AdvancedNetworkManagement.html" title="Chapter 25. Advanced Network Management"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 24. Winbind: Use of Domain Accounts</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="VFS.html">Prev</a> </td><th width="60%" align="center">Part III. Advanced Configuration</th><td width="20%" align="right"> <a accesskey="n" href="AdvancedNetworkManagement.html">Next</a></td></tr></table><hr></div><div class="chapter" title="Chapter 24. Winbind: Use of Domain Accounts"><div class="titlepage"><div><div><h2 class="title"><a name="winbind"></a>Chapter 24. Winbind: Use of Domain Accounts</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Tim</span> <span class="surname">Potter</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email">&lt;<a class="email" href="mailto:tpot@linuxcare.com.au">tpot@linuxcare.com.au</a>&gt;</code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Andrew</span> <span class="surname">Tridgell</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email">&lt;<a class="email" href="mailto:tridge@samba.org">tridge@samba.org</a>&gt;</code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Naag</span> <span class="surname">Mummaneni</span></h3><span class="contrib">Notes for Solaris</span> <div class="affiliation"><div class="address"><p><code class="email">&lt;<a class="email" href="mailto:getnag@rediffmail.com">getnag@rediffmail.com</a>&gt;</code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="surname">Trostel</span></h3><div class="affiliation"><span class="orgname">SNAP<br></span><div class="address"><p><code class="email">&lt;<a class="email" href="mailto:jtrostel@snapserver.com">jtrostel@snapserver.com</a>&gt;</code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="othername">R.</span> <span class="surname">Vernooij</span></h3><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><code class="email">&lt;<a class="email" href="mailto:jelmer@samba.org">jelmer@samba.org</a>&gt;</code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="othername">H.</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email">&lt;<a class="email" href="mailto:jht@samba.org">jht@samba.org</a>&gt;</code></p></div></div></div></div><div><p class="pubdate">June 15, 2005</p></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="winbind.html#id417272">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="winbind.html#id417589">Introduction</a></span></dt><dt><span class="sect1"><a href="winbind.html#id417666">What Winbind Provides</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id417805">Target Uses</a></span></dt><dt><span class="sect2"><a href="winbind.html#id417844">Handling of Foreign SIDs</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id417956">How Winbind Works</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id418004">Microsoft Remote Procedure Calls</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418082">Microsoft Active Directory Services</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418126">Name Service Switch</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418338">Pluggable Authentication Modules</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418479">User and Group ID Allocation</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418546">Result Caching</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id418597">Installation and Configuration</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id418602">Introduction</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418709">Requirements</a></span></dt><dt><span class="sect2"><a href="winbind.html#id418852">Testing Things Out</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id421094">Conclusion</a></span></dt><dt><span class="sect1"><a href="winbind.html#id421140">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id421173">NSCD Problem Warning</a></span></dt><dt><span class="sect2"><a href="winbind.html#id421207">Winbind Is Not Resolving Users and Groups</a></span></dt></dl></dd></dl></div><div class="sect1" title="Features and Benefits"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id417272"></a>Features and Benefits</h2></div></div></div><p>
2<a class="indexterm" name="id417280"></a>
3<a class="indexterm" name="id417286"></a>
4 Integration of UNIX and Microsoft Windows NT through a unified logon has
5 been considered a <span class="quote">&#8220;<span class="quote">holy grail</span>&#8221;</span> in heterogeneous computing environments for
6 a long time.
7 </p><p>
8<a class="indexterm" name="id417301"></a>
9<a class="indexterm" name="id417308"></a>
10<a class="indexterm" name="id417315"></a>
11<a class="indexterm" name="id417322"></a>
12 There is one other facility without which UNIX and Microsoft Windows network
13 interoperability would suffer greatly. It is imperative that there be a
14 mechanism for sharing files across UNIX systems and to be able to assign
15 domain user and group ownerships with integrity.
16 </p><p>
17<a class="indexterm" name="id417334"></a>
18<a class="indexterm" name="id417343"></a>
19<a class="indexterm" name="id417350"></a>
20<a class="indexterm" name="id417357"></a>
21 <span class="emphasis"><em>winbind</em></span> is a component of the Samba suite of programs that
22 solves the unified logon problem. Winbind uses a UNIX implementation of Microsoft
23 RPC calls, Pluggable Authentication Modules (PAMs), and the name service switch (NSS) to
24 allow Windows NT domain users to appear and operate as UNIX users on a UNIX
25 machine. This chapter describes the Winbind system, the functionality
26 it provides, how it is configured, and how it works internally.
27 </p><p>
28 Winbind provides three separate functions:
29 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
30<a class="indexterm" name="id417380"></a>
31<a class="indexterm" name="id417387"></a>
32 Authentication of user credentials (via PAM). This makes it possible to
33 log onto a UNIX/Linux system using user and group accounts from a Windows
34 NT4 (including a Samba domain) or an Active Directory domain.
35 </p></li><li class="listitem"><p>
36<a class="indexterm" name="id417400"></a>
37<a class="indexterm" name="id417407"></a>
38 Identity resolution (via NSS). This is the default when winbind is not used.
39 </p></li><li class="listitem"><p>
40<a class="indexterm" name="id417418"></a>
41<a class="indexterm" name="id417425"></a>
42<a class="indexterm" name="id417432"></a>
43<a class="indexterm" name="id417438"></a>
44<a class="indexterm" name="id417445"></a>
45<a class="indexterm" name="id417452"></a>
46 Winbind maintains a database called winbind_idmap.tdb in which it stores
47 mappings between UNIX UIDs, GIDs, and NT SIDs. This mapping is used only
48 for users and groups that do not have a local UID/GID. It stores the UID/GID
49 allocated from the idmap uid/gid range that it has mapped to the NT SID.
50 If <em class="parameter"><code>idmap backend</code></em> has been specified as <code class="constant">ldap:ldap://hostname[:389]</code>,
51 then instead of using a local mapping, Winbind will obtain this information
52 from the LDAP database.
53 </p></li></ul></div><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
54 <a class="indexterm" name="id417477"></a>
55 <a class="indexterm" name="id417484"></a>
56<a class="indexterm" name="id417493"></a>
57<a class="indexterm" name="id417500"></a>
58<a class="indexterm" name="id417507"></a>
59<a class="indexterm" name="id417514"></a>
60 If <code class="literal">winbindd</code> is not running, smbd (which calls <code class="literal">winbindd</code>) will fall back to
61 using purely local information from <code class="filename">/etc/passwd</code> and <code class="filename">/etc/group</code> and no dynamic
62 mapping will be used. On an operating system that has been enabled with the NSS,
63 the resolution of user and group information will be accomplished via NSS.
64 </p></div><div class="figure"><a name="winbind_idmap"></a><p class="title"><b>Figure 24.1. Winbind Idmap</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/idmap_winbind_no_loop.png" width="243" alt="Winbind Idmap"></div></div></div><br class="figure-break"></div><div class="sect1" title="Introduction"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id417589"></a>Introduction</h2></div></div></div><p>It is well known that UNIX and Microsoft Windows NT have
65 different models for representing user and group information and
66 use different technologies for implementing them. This fact has
67 made it difficult to integrate the two systems in a satisfactory
68 manner.</p><p>
69<a class="indexterm" name="id417602"></a>
70<a class="indexterm" name="id417609"></a>
71 One common solution in use today has been to create
72 identically named user accounts on both the UNIX and Windows systems
73 and use the Samba suite of programs to provide file and print services
74 between the two. This solution is far from perfect, however, because
75 adding and deleting users on both sets of machines becomes a chore,
76 and two sets of passwords are required both of which
77 can lead to synchronization problems between the UNIX and Windows
78 systems and confusion for users.</p><p>We divide the unified logon problem for UNIX machines into
79 three smaller problems:</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>Obtaining Windows NT user and group information.
80 </p></li><li class="listitem"><p>Authenticating Windows NT users.
81 </p></li><li class="listitem"><p>Password changing for Windows NT users.
82 </p></li></ul></div><p>
83<a class="indexterm" name="id417648"></a>
84<a class="indexterm" name="id417654"></a>
85 Ideally, a prospective solution to the unified logon problem
86 would satisfy all the above components without duplication of
87 information on the UNIX machines and without creating additional
88 tasks for the system administrator when maintaining users and
89 groups on either system. The Winbind system provides a simple
90 and elegant solution to all three components of the unified logon
91 problem.</p></div><div class="sect1" title="What Winbind Provides"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id417666"></a>What Winbind Provides</h2></div></div></div><p>
92<a class="indexterm" name="id417674"></a>
93<a class="indexterm" name="id417681"></a>
94<a class="indexterm" name="id417688"></a>
95<a class="indexterm" name="id417695"></a>
96 Winbind unifies UNIX and Windows NT account management by
97 allowing a UNIX box to become a full member of an NT domain. Once
98 this is done, the UNIX box will see NT users and groups as if
99 they were <span class="quote">&#8220;<span class="quote">native</span>&#8221;</span> UNIX users and groups, allowing the NT domain
100 to be used in much the same manner that NIS+ is used within
101 UNIX-only environments.</p><p>
102<a class="indexterm" name="id417711"></a>
103<a class="indexterm" name="id417718"></a>
104<a class="indexterm" name="id417725"></a>
105<a class="indexterm" name="id417731"></a>
106 The end result is that whenever a
107 program on the UNIX machine asks the operating system to look up
108 a user or group name, the query will be resolved by asking the
109 NT domain controller for the specified domain to do the lookup.
110 Because Winbind hooks into the operating system at a low level
111 (via the NSS name resolution modules in the C library), this
112 redirection to the NT domain controller is completely
113 transparent.</p><p>
114<a class="indexterm" name="id417745"></a>
115<a class="indexterm" name="id417752"></a>
116 Users on the UNIX machine can then use NT user and group
117 names as they would <span class="quote">&#8220;<span class="quote">native</span>&#8221;</span> UNIX names. They can chown files
118 so they are owned by NT domain users or even login to the
119 UNIX machine and run a UNIX X Window session as a domain user.</p><p>
120<a class="indexterm" name="id417768"></a>
121 The only obvious indication that Winbind is being used is
122 that user and group names take the form <code class="constant">DOMAIN\user</code> and
123 <code class="constant">DOMAIN\group</code>. This is necessary because it allows Winbind to determine
124 that redirection to a domain controller is wanted for a particular
125 lookup and which trusted domain is being referenced.</p><p>
126<a class="indexterm" name="id417787"></a>
127<a class="indexterm" name="id417794"></a>
128 Additionally, Winbind provides an authentication service that hooks into the PAM system
129 to provide authentication via an NT domain to any PAM-enabled
130 applications. This capability solves the problem of synchronizing
131 passwords between systems, since all passwords are stored in a single
132 location (on the domain controller).</p><div class="sect2" title="Target Uses"><div class="titlepage"><div><div><h3 class="title"><a name="id417805"></a>Target Uses</h3></div></div></div><p>
133<a class="indexterm" name="id417813"></a>
134 Winbind is targeted at organizations that have an
135 existing NT-based domain infrastructure into which they wish
136 to put UNIX workstations or servers. Winbind will allow these
137 organizations to deploy UNIX workstations without having to
138 maintain a separate account infrastructure. This greatly
139 simplifies the administrative overhead of deploying UNIX
140 workstations into an NT-based organization.</p><p>
141<a class="indexterm" name="id417826"></a>
142<a class="indexterm" name="id417833"></a>
143 Another interesting way in which we expect Winbind to
144 be used is as a central part of UNIX-based appliances. Appliances
145 that provide file and print services to Microsoft-based networks
146 will be able to use Winbind to provide seamless integration of
147 the appliance into the domain.</p></div><div class="sect2" title="Handling of Foreign SIDs"><div class="titlepage"><div><div><h3 class="title"><a name="id417844"></a>Handling of Foreign SIDs</h3></div></div></div><p>
148<a class="indexterm" name="id417852"></a>
149 The term <span class="emphasis"><em>foreign SID</em></span> is often met with the reaction that it
150 is not relevant to a particular environment. The following documents an interchange
151 that took place on the Samba mailing list. It is a good example of the confusion
152 often expressed regarding the use of winbind.
153 </p><p>
154<a class="indexterm" name="id417868"></a>
155 Fact: Winbind is needed to handle users who use workstations that are NOT part
156 of the local domain.
157 </p><p>
158<a class="indexterm" name="id417879"></a>
159 Response: <span class="quote">&#8220;<span class="quote">Why? I've used Samba with workstations that are not part of my domains
160 lots of times without using winbind. I thought winbind was for using Samba as a member server
161 in a domain controlled by another Samba/Windows PDC.</span>&#8221;</span>
162 </p><p>
163<a class="indexterm" name="id417895"></a>
164<a class="indexterm" name="id417901"></a>
165<a class="indexterm" name="id417908"></a>
166 If the Samba server will be accessed from a domain other than the local Samba domain, or
167 if there will be access from machines that are not local domain members, winbind will
168 permit the allocation of UIDs and GIDs from the assigned pool that will keep the identity
169 of the foreign user separate from users that are members of the Samba domain.
170 </p><p>
171<a class="indexterm" name="id417921"></a>
172<a class="indexterm" name="id417927"></a>
173<a class="indexterm" name="id417934"></a>
174<a class="indexterm" name="id417941"></a>
175 This means that winbind is eminently useful in cases where a single
176 Samba PDC on a local network is combined with both domain member and domain non-member workstations.
177 If winbind is not used, the user george on a Windows workstation that is not a domain
178 member will be able to access the files of a user called george in the account database
179 of the Samba server that is acting as a PDC. When winbind is used, the default condition
180 is that the local user george will be treated as the account DOMAIN\george and the
181 foreign (non-member of the domain) account will be treated as MACHINE\george because
182 each has a different SID.
183 </p></div></div><div class="sect1" title="How Winbind Works"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id417956"></a>How Winbind Works</h2></div></div></div><p>
184<a class="indexterm" name="id417964"></a>
185<a class="indexterm" name="id417971"></a>
186<a class="indexterm" name="id417978"></a>
187<a class="indexterm" name="id417984"></a>
188 The Winbind system is designed around a client/server
189 architecture. A long-running <code class="literal">winbindd</code> daemon
190 listens on a UNIX domain socket waiting for requests
191 to arrive. These requests are generated by the NSS and PAM
192 clients and are processed sequentially.</p><p>The technologies used to implement Winbind are described
193 in detail below.</p><div class="sect2" title="Microsoft Remote Procedure Calls"><div class="titlepage"><div><div><h3 class="title"><a name="id418004"></a>Microsoft Remote Procedure Calls</h3></div></div></div><p>
194<a class="indexterm" name="id418012"></a>
195<a class="indexterm" name="id418021"></a>
196<a class="indexterm" name="id418028"></a>
197<a class="indexterm" name="id418034"></a>
198<a class="indexterm" name="id418041"></a>
199 Over the last few years, efforts have been underway by various Samba Team members to implement various aspects of
200 the Microsoft Remote Procedure Call (MSRPC) system. This system is used for most network-related operations
201 between Windows NT machines, including remote management, user authentication, and print spooling. Although
202 initially this work was done to aid the implementation of Primary Domain Controller (PDC) functionality in
203 Samba, it has also yielded a body of code that can be used for other purposes.
204 </p><p>
205<a class="indexterm" name="id418056"></a>
206<a class="indexterm" name="id418063"></a>
207<a class="indexterm" name="id418069"></a>
208 Winbind uses various MSRPC calls to enumerate domain users and groups and to obtain detailed information about
209 individual users or groups. Other MSRPC calls can be used to authenticate NT domain users and to change user
210 passwords. By directly querying a Windows PDC for user and group information, Winbind maps the NT account
211 information onto UNIX user and group names.
212 </p></div><div class="sect2" title="Microsoft Active Directory Services"><div class="titlepage"><div><div><h3 class="title"><a name="id418082"></a>Microsoft Active Directory Services</h3></div></div></div><p>
213<a class="indexterm" name="id418090"></a>
214<a class="indexterm" name="id418096"></a>
215<a class="indexterm" name="id418103"></a>
216<a class="indexterm" name="id418110"></a>
217 Since late 2001, Samba has gained the ability to interact with Microsoft Windows 2000 using its <span class="quote">&#8220;<span class="quote">native
218 mode</span>&#8221;</span> protocols rather than the NT4 RPC services. Using LDAP and Kerberos, a domain member running
219 Winbind can enumerate users and groups in exactly the same way as a Windows 200x client would, and in so doing
220 provide a much more efficient and effective Winbind implementation.
221 </p></div><div class="sect2" title="Name Service Switch"><div class="titlepage"><div><div><h3 class="title"><a name="id418126"></a>Name Service Switch</h3></div></div></div><p>
222<a class="indexterm" name="id418134"></a>
223<a class="indexterm" name="id418140"></a>
224<a class="indexterm" name="id418147"></a>
225<a class="indexterm" name="id418153"></a>
226 The NSS is a feature that is present in many UNIX operating systems. It allows system
227 information such as hostnames, mail aliases, and user information
228 to be resolved from different sources. For example, a standalone
229 UNIX workstation may resolve system information from a series of
230 flat files stored on the local file system. A networked workstation
231 may first attempt to resolve system information from local files,
232 and then consult an NIS database for user information or a DNS server
233 for hostname information.</p><p>
234<a class="indexterm" name="id418168"></a>
235<a class="indexterm" name="id418174"></a>
236<a class="indexterm" name="id418181"></a>
237<a class="indexterm" name="id418188"></a>
238<a class="indexterm" name="id418195"></a>
239 The NSS application programming interface allows Winbind to present itself as a source of system
240 information when resolving UNIX usernames and groups. Winbind uses this interface and information obtained
241 from a Windows NT server using MSRPC calls to provide a new source of account enumeration. Using standard UNIX
242 library calls, you can enumerate the users and groups on a UNIX machine running Winbind and see all users and
243 groups in an NT domain plus any trusted domain as though they were local users and groups.
244 </p><p>
245<a class="indexterm" name="id418209"></a>
246<a class="indexterm" name="id418216"></a>
247<a class="indexterm" name="id418222"></a>
248 The primary control file for NSS is <code class="filename">/etc/nsswitch.conf</code>. When a UNIX application
249 makes a request to do a lookup, the C library looks in <code class="filename">/etc/nsswitch.conf</code> for a line that
250 matches the service type being requested; for example, the <span class="quote">&#8220;<span class="quote">passwd</span>&#8221;</span> service type is used when
251 user or group names are looked up. This config line specifies which implementations of that service should be
252 tried and in what order. If the passwd config line is:
253</p><pre class="screen">
254passwd: files example
255</pre><p>
256<a class="indexterm" name="id418254"></a>
257<a class="indexterm" name="id418260"></a>
258<a class="indexterm" name="id418267"></a>
259 then the C library will first load a module called <code class="filename">/lib/libnss_files.so</code> followed
260 by the module <code class="filename">/lib/libnss_example.so</code>. The C library will dynamically load each of these
261 modules in turn and call resolver functions within the modules to try to resolve the request. Once the request
262 is resolved, the C library returns the result to the application.
263 </p><p>
264<a class="indexterm" name="id418292"></a>
265<a class="indexterm" name="id418298"></a>
266<a class="indexterm" name="id418305"></a>
267 This NSS interface provides an easy way for Winbind to hook into the operating system. All that needs
268 to be done is to put <code class="filename">libnss_winbind.so</code> in <code class="filename">/lib/</code> then add
269 <span class="quote">&#8220;<span class="quote">winbind</span>&#8221;</span> into <code class="filename">/etc/nsswitch.conf</code> at the appropriate place. The C library
270 will then call Winbind to resolve user and group names.
271 </p></div><div class="sect2" title="Pluggable Authentication Modules"><div class="titlepage"><div><div><h3 class="title"><a name="id418338"></a>Pluggable Authentication Modules</h3></div></div></div><p>
272<a class="indexterm" name="id418346"></a>
273<a class="indexterm" name="id418352"></a>
274<a class="indexterm" name="id418359"></a>
275<a class="indexterm" name="id418366"></a>
276 PAMs provide a system for abstracting authentication and authorization technologies. With a PAM
277 module, it is possible to specify different authentication methods for different system applications without
278 having to recompile these applications. PAM is also useful for implementing a particular policy for
279 authorization. For example, a system administrator may only allow console logins from users stored in the
280 local password file but only allow users resolved from an NIS database to log in over the network.
281 </p><p>
282<a class="indexterm" name="id418380"></a>
283<a class="indexterm" name="id418387"></a>
284<a class="indexterm" name="id418394"></a>
285<a class="indexterm" name="id418400"></a>
286<a class="indexterm" name="id418407"></a>
287 Winbind uses the authentication management and password management PAM interface to integrate Windows
288 NT users into a UNIX system. This allows Windows NT users to log in to a UNIX machine and be authenticated
289 against a suitable PDC. These users can also change their passwords and have this change take effect directly
290 on the PDC.
291 </p><p>
292<a class="indexterm" name="id418420"></a>
293<a class="indexterm" name="id418426"></a>
294<a class="indexterm" name="id418433"></a>
295<a class="indexterm" name="id418440"></a>
296 PAM is configured by providing control files in the directory <code class="filename">/etc/pam.d/</code> for
297 each of the services that require authentication. When an authentication request is made by an application,
298 the PAM code in the C library looks up this control file to determine what modules to load to do the
299 authentication check and in what order. This interface makes adding a new authentication service for Winbind
300 very easy: simply copy the <code class="filename">pam_winbind.so</code> module to <code class="filename">/lib/security/</code>,
301 and the PAM control files for relevant services are updated to allow authentication via Winbind. See the PAM
302 documentation in <a class="link" href="pam.html" title="Chapter 28. PAM-Based Distributed Authentication">PAM-Based Distributed Authentication</a>, for more information.
303 </p></div><div class="sect2" title="User and Group ID Allocation"><div class="titlepage"><div><div><h3 class="title"><a name="id418479"></a>User and Group ID Allocation</h3></div></div></div><p>
304<a class="indexterm" name="id418486"></a>
305<a class="indexterm" name="id418493"></a>
306<a class="indexterm" name="id418500"></a>
307 When a user or group is created under Windows NT/200x, it is allocated a numerical relative identifier
308 (RID). This is slightly different from UNIX, which has a range of numbers that are used to identify users and
309 the same range used to identify groups. It is Winbind's job to convert RIDs to UNIX ID numbers and vice versa.
310 When Winbind is configured, it is given part of the UNIX user ID space and a part of the UNIX group ID space
311 in which to store Windows NT users and groups. If a Windows NT user is resolved for the first time, it is
312 allocated the next UNIX ID from the range. The same process applies for Windows NT groups. Over time, Winbind
313 will have mapped all Windows NT users and groups to UNIX user IDs and group IDs.
314 </p><p>
315<a class="indexterm" name="id418516"></a>
316<a class="indexterm" name="id418523"></a>
317<a class="indexterm" name="id418529"></a>
318<a class="indexterm" name="id418536"></a>
319 The results of this mapping are stored persistently in an ID mapping database held in a tdb database.
320 This ensures that RIDs are mapped to UNIX IDs in a consistent way.
321 </p></div><div class="sect2" title="Result Caching"><div class="titlepage"><div><div><h3 class="title"><a name="id418546"></a>Result Caching</h3></div></div></div><p>
322<a class="indexterm" name="id418554"></a>
323<a class="indexterm" name="id418561"></a>
324<a class="indexterm" name="id418567"></a>
325<a class="indexterm" name="id418574"></a>
326<a class="indexterm" name="id418581"></a>
327 An active directory system can generate a lot of user and group name lookups. To reduce the network
328 cost of these lookups, Winbind uses a caching scheme based on the SAM sequence number supplied by NT domain
329 controllers. User or group information returned by a PDC is cached by Winbind along with a sequence number
330 also returned by the PDC. This sequence number is incremented by Windows NT whenever any user or group
331 information is modified. If a cached entry has expired, the sequence number is requested from the PDC and
332 compared against the sequence number of the cached entry. If the sequence numbers do not match, then the
333 cached information is discarded and up-to-date information is requested directly from the PDC.
334 </p></div></div><div class="sect1" title="Installation and Configuration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id418597"></a>Installation and Configuration</h2></div></div></div><div class="sect2" title="Introduction"><div class="titlepage"><div><div><h3 class="title"><a name="id418602"></a>Introduction</h3></div></div></div><p>
335<a class="indexterm" name="id418610"></a>
336<a class="indexterm" name="id418617"></a>
337<a class="indexterm" name="id418624"></a>
338This section describes the procedures used to get Winbind up and running. Winbind is capable of providing
339access and authentication control for Windows Domain users through an NT or Windows 200x PDC for regular
340services, such as telnet and ftp, as well for Samba services.
341</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
342 <span class="emphasis"><em>Why should I do this?</em></span>
343 </p><p>
344<a class="indexterm" name="id418647"></a>
345<a class="indexterm" name="id418654"></a>
346<a class="indexterm" name="id418661"></a>
347<a class="indexterm" name="id418667"></a>
348This allows the Samba administrator to rely on the authentication mechanisms on the Windows NT/200x PDC
349for the authentication of domain members. Windows NT/200x users no longer need to have separate accounts on
350the Samba server.
351 </p></li><li class="listitem"><p>
352 <span class="emphasis"><em>Who should be reading this document?</em></span>
353 </p><p>
354<a class="indexterm" name="id418690"></a>
355<a class="indexterm" name="id418696"></a>
356This document is designed for system administrators. If you are implementing Samba on a file server and wish
357to (fairly easily) integrate existing Windows NT/200x users from your PDC onto the Samba server, this document
358is for you.
359 </p></li></ul></div></div><div class="sect2" title="Requirements"><div class="titlepage"><div><div><h3 class="title"><a name="id418709"></a>Requirements</h3></div></div></div><p>
360<a class="indexterm" name="id418717"></a>
361<a class="indexterm" name="id418724"></a>
362<a class="indexterm" name="id418730"></a>
363If you have a Samba configuration file that you are currently using, <span class="emphasis"><em>BACK IT UP!</em></span>
364If your system already uses PAM, <span class="emphasis"><em>back up the <code class="filename">/etc/pam.d</code> directory
365contents!</em></span> If you haven't already made a boot disk, <span class="emphasis"><em>MAKE ONE NOW!</em></span>
366</p><p>
367<a class="indexterm" name="id418758"></a>
368<a class="indexterm" name="id418765"></a>
369<a class="indexterm" name="id418772"></a>
370Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's
371why you want to be able to boot back into your machine in single-user mode and restore your
372<code class="filename">/etc/pam.d</code> to the original state it was in if you get frustrated with the
373way things are going.
374</p><p>
375<a class="indexterm" name="id418790"></a>
376<a class="indexterm" name="id418797"></a>
377The latest version of Samba-3 includes a functioning winbindd daemon. Please refer to the <a class="ulink" href="http://samba.org/" target="_top">main Samba Web page</a>, or better yet, your closest Samba mirror site for
378instructions on downloading the source code.
379</p><p>
380<a class="indexterm" name="id418815"></a>
381<a class="indexterm" name="id418821"></a>
382<a class="indexterm" name="id418828"></a>
383<a class="indexterm" name="id418835"></a>
384To allow domain users the ability to access Samba shares and files, as well as potentially other services
385provided by your Samba machine, PAM must be set up properly on your
386machine. In order to compile the Winbind modules, the PAM development libraries should be installed
387on your system. Please refer to the <a class="ulink" href="http://www.kernel.org/pub/linux/libs/pam/" target="_top">PAM Web Site</a>.
388</p></div><div class="sect2" title="Testing Things Out"><div class="titlepage"><div><div><h3 class="title"><a name="id418852"></a>Testing Things Out</h3></div></div></div><p>
389<a class="indexterm" name="id418860"></a>
390<a class="indexterm" name="id418867"></a>
391<a class="indexterm" name="id418874"></a>
392<a class="indexterm" name="id418880"></a>
393<a class="indexterm" name="id418887"></a>
394Before starting, it is probably best to kill off all the Samba-related daemons running on your server.
395Kill off all <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> processes that may be running. To use PAM,
396make sure that you have the standard PAM package that supplies the <code class="filename">/etc/pam.d</code>
397directory structure, including the PAM modules that are used by PAM-aware services, several PAM libraries,
398and the <code class="filename">/usr/doc</code> and <code class="filename">/usr/man</code> entries for PAM. Winbind is built
399better in Samba if the pam-devel package is also installed. This package includes the header files
400needed to compile PAM-aware applications.
401</p><div class="sect3" title="Configure nsswitch.conf and the Winbind Libraries on Linux and Solaris"><div class="titlepage"><div><div><h4 class="title"><a name="id418935"></a>Configure <code class="filename">nsswitch.conf</code> and the Winbind Libraries on Linux and Solaris</h4></div></div></div><p>
402<a class="indexterm" name="id418949"></a>
403<a class="indexterm" name="id418955"></a>
404<a class="indexterm" name="id418962"></a>
405<a class="indexterm" name="id418969"></a>
406PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install
407the <code class="filename">pam-devel</code> libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3
408may auto-install the Winbind files into their correct locations on your system, so before you get too far down
409the track, be sure to check if the following configuration is really
410necessary. You may only need to configure
411<code class="filename">/etc/nsswitch.conf</code>.
412</p><p>
413The libraries needed to run the <span class="application">winbindd</span> daemon through nsswitch need to be copied to their proper locations:
414</p><p>
415<a class="indexterm" name="id419004"></a>
416</p><pre class="screen">
417<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/libnss_winbind.so /lib</code></strong>
418</pre><p>
419</p><p>
420I also found it necessary to make the following symbolic link:
421</p><p>
422<code class="prompt">root# </code> <strong class="userinput"><code>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</code></strong>
423</p><p>And, in the case of Sun Solaris:
424<a class="indexterm" name="id419049"></a>
425</p><pre class="screen">
426<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1</code></strong>
427<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1</code></strong>
428<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</code></strong>
429</pre><p>
430</p><p>
431<a class="indexterm" name="id419097"></a>
432As root, edit <code class="filename">/etc/nsswitch.conf</code> to allow user and group entries to be visible from the
433<span class="application">winbindd</span> daemon. My <code class="filename">/etc/nsswitch.conf</code> file looked like this after editing:
434</p><pre class="programlisting">
435passwd: files winbind
436shadow: files
437group: files winbind
438</pre><p>
439<a class="indexterm" name="id419131"></a>
440<a class="indexterm" name="id419138"></a>
441<a class="indexterm" name="id419145"></a>
442<a class="indexterm" name="id419151"></a>
443<a class="indexterm" name="id419158"></a>
444The libraries needed by the <code class="literal">winbindd</code> daemon will be automatically
445entered into the <code class="literal">ldconfig</code> cache the next time
446your system reboots, but it is faster (and you do not need to reboot) if you do it manually:
447</p><pre class="screen">
448<code class="prompt">root# </code><strong class="userinput"><code>/sbin/ldconfig -v | grep winbind</code></strong>
449</pre><p>
450This makes <code class="filename">libnss_winbind</code> available to winbindd and reports the current
451search path that is used by the dynamic link loader. The use of the <code class="literal">grep</code>
452filters the output of the <code class="literal">ldconfig</code> command so that we may see proof that
453this library is indeed recognized by the dynamic link loader.
454</p><p>
455<a class="indexterm" name="id419218"></a>
456<a class="indexterm" name="id419224"></a>
457<a class="indexterm" name="id419231"></a>
458<a class="indexterm" name="id419238"></a>
459<a class="indexterm" name="id419245"></a>
460The Sun Solaris dynamic link loader management tool is called <code class="literal">crle</code>. The
461use of this tool is necessary to instruct the dynamic link loader to search directories that
462contain library files that were not supplied as part of the original operating system platform.
463The following example shows how to use this tool to add the directory <code class="filename">/usr/local/lib</code>
464to the dynamic link loader's search path:
465</p><pre class="screen">
466<code class="prompt">root# </code> crle -u -l /usr/lib:/usr/local/lib
467</pre><p>
468When executed without arguments, <code class="literal">crle</code> reports the current dynamic
469link loader configuration. This is demonstrated here:
470</p><pre class="screen">
471<code class="prompt">root# </code> crle
472
473Configuration file [version 4]: /var/ld/ld.config
474 Default Library Path (ELF): /lib:/usr/lib:/usr/local/lib
475 Trusted Directories (ELF): /lib/secure:/usr/lib/secure (system default)
476
477Command line:
478 crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/local/lib
479</pre><p>
480From this it is apparent that the <code class="filename">/usr/local/lib</code> directory is included
481in the search dynamic link libraries in order to satisfy object module dependencies.
482</p></div><div class="sect3" title="NSS Winbind on AIX"><div class="titlepage"><div><div><h4 class="title"><a name="id419308"></a>NSS Winbind on AIX</h4></div></div></div><p>(This section is only for those running AIX.)</p><p>
483<a class="indexterm" name="id419320"></a>
484<a class="indexterm" name="id419326"></a>
485<a class="indexterm" name="id419333"></a>
486<a class="indexterm" name="id419340"></a>
487<a class="indexterm" name="id419347"></a>
488<a class="indexterm" name="id419354"></a>
489The Winbind AIX identification module gets built as <code class="filename">libnss_winbind.so</code> in the
490nsswitch directory of the Samba source. This file can be copied to <code class="filename">/usr/lib/security</code>,
491and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following:
492</p><pre class="programlisting">
493WINBIND:
494 program = /usr/lib/security/WINBIND
495 options = authonly
496</pre><p>
497can then be added to <code class="filename">/usr/lib/security/methods.cfg</code>. This module only supports
498identification, but there have been reports of success using the standard Winbind PAM module for
499authentication. Use caution configuring loadable authentication modules, since misconfiguration can make
500it impossible to log on to the system. Information regarding the AIX authentication module API can
501be found in the <span class="quote">&#8220;<span class="quote">Kernel Extensions and Device Support Programming Concepts for AIX</span>&#8221;</span> document that
502describes the <a class="ulink" href="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixprggd/kernextc/sec_load_mod.htm" target="_top">
503Loadable Authentication Module Programming Interface</a> for AIX. Further information on administering the modules
504can be found in the <a class="ulink" href="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixbman/baseadmn/iandaadmin.htm" target="_top">System
505Management Guide: Operating System and Devices.</a>
506</p></div><div class="sect3" title="Configure smb.conf"><div class="titlepage"><div><div><h4 class="title"><a name="id419410"></a>Configure smb.conf</h4></div></div></div><p>
507<a class="indexterm" name="id419418"></a>
508<a class="indexterm" name="id419425"></a>
509<a class="indexterm" name="id419432"></a>
510Several parameters are needed in the <code class="filename">smb.conf</code> file to control the behavior of <span class="application">winbindd</span>. These
511are described in more detail in the <a class="citerefentry" href="winbindd.8.html"><span class="citerefentry"><span class="refentrytitle">winbindd</span>(8)</span></a> man page. My <code class="filename">smb.conf</code> file, as shown in <a class="link" href="winbind.html#winbindcfg" title="Example 24.1. smb.conf for Winbind Setup">the smb.conf for Winbind Setup</a>, was modified to include the necessary entries in the [global] section.
512</p><div class="example"><a name="winbindcfg"></a><p class="title"><b>Example 24.1. smb.conf for Winbind Setup</b></p><div class="example-contents"><table border="0" summary="Simple list" class="simplelist"><tr><td> </td></tr><tr><td><em class="parameter"><code>[global]</code></em></td></tr><tr><td># separate domain and username with '\', like DOMAIN\username</td></tr><tr><td><a class="indexterm" name="id419503"></a><em class="parameter"><code>winbind separator = \</code></em></td></tr><tr><td># use uids from 10000 to 20000 for domain users</td></tr><tr><td><a class="indexterm" name="id419518"></a><em class="parameter"><code>idmap uid = 10000-20000</code></em></td></tr><tr><td># use gids from 10000 to 20000 for domain groups</td></tr><tr><td><a class="indexterm" name="id419533"></a><em class="parameter"><code>idmap gid = 10000-20000</code></em></td></tr><tr><td># allow enumeration of winbind users and groups</td></tr><tr><td><a class="indexterm" name="id419548"></a><em class="parameter"><code>winbind enum users = yes</code></em></td></tr><tr><td><a class="indexterm" name="id419560"></a><em class="parameter"><code>winbind enum groups = yes</code></em></td></tr><tr><td># give winbind users a real shell (only needed if they have telnet access)</td></tr><tr><td><a class="indexterm" name="id419576"></a><em class="parameter"><code>template homedir = /home/winnt/%D/%U</code></em></td></tr><tr><td><a class="indexterm" name="id419587"></a><em class="parameter"><code>template shell = /bin/bash</code></em></td></tr></table></div></div><br class="example-break"></div><div class="sect3" title="Join the Samba Server to the PDC Domain"><div class="titlepage"><div><div><h4 class="title"><a name="id419601"></a>Join the Samba Server to the PDC Domain</h4></div></div></div><p>
513<a class="indexterm" name="id419609"></a>
514<a class="indexterm" name="id419616"></a>
515<a class="indexterm" name="id419622"></a>
516All machines that will participate in domain security should be members of
517the domain. This applies also to the PDC and all BDCs.
518</p><p>
519<a class="indexterm" name="id419633"></a>
520<a class="indexterm" name="id419640"></a>
521<a class="indexterm" name="id419647"></a>
522<a class="indexterm" name="id419658"></a>
523<a class="indexterm" name="id419665"></a>
524<a class="indexterm" name="id419671"></a>
525<a class="indexterm" name="id419678"></a>
526<a class="indexterm" name="id419685"></a>
527<a class="indexterm" name="id419692"></a>
528The process of joining a domain requires the use of the <code class="literal">net rpc join</code>
529command. This process communicates with the domain controller it will register with
530(usually the PDC) via MS DCE RPC. This means, of course, that the <code class="literal">smbd</code>
531process must be running on the target domain controller. It is therefore necessary to temporarily
532start Samba on a PDC so that it can join its own domain.
533</p><p>
534<a class="indexterm" name="id419716"></a>
535<a class="indexterm" name="id419723"></a>
536<a class="indexterm" name="id419730"></a>
537Enter the following command to make the Samba server join the domain, where <em class="replaceable"><code>PDC</code></em> is
538the name of your PDC and <em class="replaceable"><code>Administrator</code></em> is a domain user who has administrative
539privileges in the domain.
540</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
541<a class="indexterm" name="id419749"></a>
542<a class="indexterm" name="id419756"></a>
543<a class="indexterm" name="id419763"></a>
544<a class="indexterm" name="id419769"></a>
545Before attempting to join a machine to the domain, verify that Samba is running
546on the target domain controller (usually PDC) and that it is capable of being reached via ports
547137/udp, 135/tcp, 139/tcp, and 445/tcp (if Samba or Windows Server 2Kx).
548</p></div><p>
549<a class="indexterm" name="id419782"></a>
550The use of the <code class="literal">net rpc join</code> facility is shown here:
551</p><pre class="screen">
552<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/net rpc join -S PDC -U Administrator</code></strong>
553</pre><p>
554The proper response to the command should be <span class="quote">&#8220;<span class="quote">Joined the domain
555<em class="replaceable"><code>DOMAIN</code></em></span>&#8221;</span> where <em class="replaceable"><code>DOMAIN</code></em>
556is your domain name.
557</p></div><div class="sect3" title="Starting and Testing the winbindd Daemon"><div class="titlepage"><div><div><h4 class="title"><a name="id419828"></a>Starting and Testing the <code class="literal">winbindd</code> Daemon</h4></div></div></div><p>
558<a class="indexterm" name="id419842"></a>
559<a class="indexterm" name="id419849"></a>
560<a class="indexterm" name="id419855"></a>
561Eventually, you will want to modify your Samba startup script to automatically invoke the winbindd daemon when
562the other parts of Samba start, but it is possible to test out just the Winbind portion first. To start up
563Winbind services, enter the following command as root:
564</p><pre class="screen">
565<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/sbin/winbindd</code></strong>
566</pre><p>
567Use the appropriate path to the location of the <code class="literal">winbindd</code> executable file.
568</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
569<a class="indexterm" name="id419891"></a>
570<a class="indexterm" name="id419898"></a>
571The command to start up Winbind services assumes that Samba has been installed in the
572<code class="filename">/usr/local/samba</code> directory tree. You may need to search for the location of Samba files
573if this is not the location of <code class="literal">winbindd</code> on your system.
574</p></div><p>
575<a class="indexterm" name="id419922"></a>
576<a class="indexterm" name="id419928"></a>
577I'm always paranoid and like to make sure the daemon is really running.
578</p><pre class="screen">
579<code class="prompt">root# </code><strong class="userinput"><code>ps -ae | grep winbindd</code></strong>
580</pre><p>
581</p><p>
582<a class="indexterm" name="id419955"></a>
583This command should produce output like the following if the daemon is running.
584</p><pre class="screen">
5853025 ? 00:00:00 winbindd
586</pre><p>
587</p><p>
588<a class="indexterm" name="id419972"></a>
589<a class="indexterm" name="id419978"></a>
590Now, for the real test, try to get some information about the users on your PDC:
591</p><pre class="screen">
592<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -u</code></strong>
593</pre><p>
594This should echo back a list of users on your Windows users on your PDC. For example, I get the following
595response:
596</p><pre class="screen">
597CEO\Administrator
598CEO\burdell
599CEO\Guest
600CEO\jt-ad
601CEO\krbtgt
602CEO\TsInternetUser
603</pre><p>
604Obviously, I have named my domain <span class="quote">&#8220;<span class="quote">CEO</span>&#8221;</span> and my <a class="link" href="smb.conf.5.html#WINBINDSEPARATOR" target="_top">winbind separator</a> is
605<span class="quote">&#8220;<span class="quote">\</span>&#8221;</span>.
606</p><p>
607<a class="indexterm" name="id420032"></a>
608<a class="indexterm" name="id420039"></a>
609You can do the same sort of thing to get group information from the PDC:
610</p><pre class="screen">
611<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -g</code></strong>
612CEO\Domain Admins
613CEO\Domain Users
614CEO\Domain Guests
615CEO\Domain Computers
616CEO\Domain Controllers
617CEO\Cert Publishers
618CEO\Schema Admins
619CEO\Enterprise Admins
620CEO\Group Policy Creator Owners
621</pre><p>
622<a class="indexterm" name="id420066"></a>
623<a class="indexterm" name="id420072"></a>
624<a class="indexterm" name="id420079"></a>
625<a class="indexterm" name="id420086"></a>
626<a class="indexterm" name="id420092"></a>
627<a class="indexterm" name="id420099"></a>
628<a class="indexterm" name="id420106"></a>
629The function <code class="literal">getent</code> can now be used to get unified lists of both local and PDC users and
630groups. Try the following command:
631</p><pre class="screen">
632<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong>
633</pre><p>
634You should get a list that looks like your <code class="filename">/etc/passwd</code>
635list followed by the domain users with their new UIDs, GIDs, home
636directories, and default shells.
637</p><p>
638The same thing can be done for groups with the command:
639</p><pre class="screen">
640<code class="prompt">root# </code><strong class="userinput"><code>getent group</code></strong>
641</pre><p>
642</p></div><div class="sect3" title="Fix the init.d Startup Scripts"><div class="titlepage"><div><div><h4 class="title"><a name="id420164"></a>Fix the init.d Startup Scripts</h4></div></div></div><div class="sect4" title="Linux"><div class="titlepage"><div><div><h5 class="title"><a name="id420170"></a>Linux</h5></div></div></div><p>
643<a class="indexterm" name="id420178"></a>
644<a class="indexterm" name="id420185"></a>
645<a class="indexterm" name="id420191"></a>
646<a class="indexterm" name="id420198"></a>
647<a class="indexterm" name="id420205"></a>
648<a class="indexterm" name="id420212"></a>
649The <span class="application">winbindd</span> daemon needs to start up after the <span class="application">smbd</span> and <span class="application">nmbd</span> daemons are running. To accomplish this
650task, you need to modify the startup scripts of your system. They are located at
651<code class="filename">/etc/init.d/smb</code> in Red Hat Linux and in <code class="filename">/etc/init.d/samba</code> in Debian
652Linux. Edit your script to add commands to invoke this daemon in the proper sequence. My startup script starts
653up <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> from the <code class="filename">/usr/local/samba/bin</code> directory directly. The
654<code class="literal">start</code> function in the script looks like this:
655</p><pre class="programlisting">
656start() {
657 KIND="SMB"
658 echo -n $"Starting $KIND services: "
659 daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
660 RETVAL=$?
661 echo
662 KIND="NMB"
663 echo -n $"Starting $KIND services: "
664 daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
665 RETVAL2=$?
666 echo
667 KIND="Winbind"
668 echo -n $"Starting $KIND services: "
669 daemon /usr/local/samba/sbin/winbindd
670 RETVAL3=$?
671 echo
672 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
673 touch /var/lock/subsys/smb || RETVAL=1
674 return $RETVAL
675}
676</pre><p>If you would like to run winbindd in dual daemon mode, replace the line:
677</p><pre class="programlisting">
678 daemon /usr/local/samba/sbin/winbindd
679</pre><p>
680
681in the example above with:
682
683</p><pre class="programlisting">
684 daemon /usr/local/samba/sbin/winbindd -D
685</pre><p>.
686</p><p>
687The <code class="literal">stop</code> function has a corresponding entry to shut down the services and looks like this:
688</p><pre class="programlisting">
689stop() {
690 KIND="SMB"
691 echo -n $"Shutting down $KIND services: "
692 killproc smbd
693 RETVAL=$?
694 echo
695 KIND="NMB"
696 echo -n $"Shutting down $KIND services: "
697 killproc nmbd
698 RETVAL2=$?
699 echo
700 KIND="Winbind"
701 echo -n $"Shutting down $KIND services: "
702 killproc winbindd
703 RETVAL3=$?
704 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
705 rm -f /var/lock/subsys/smb
706 echo ""
707 return $RETVAL
708}
709</pre></div><div class="sect4" title="Solaris"><div class="titlepage"><div><div><h5 class="title"><a name="id420337"></a>Solaris</h5></div></div></div><p>
710Winbind does not work on Solaris 9; see <a class="link" href="Portability.html#winbind-solaris9" title="Winbind on Solaris 9">Winbind on Solaris 9 section</a>
711for details.
712</p><p>
713<a class="indexterm" name="id420356"></a>
714<a class="indexterm" name="id420363"></a>
715<a class="indexterm" name="id420370"></a>
716<a class="indexterm" name="id420377"></a>
717<a class="indexterm" name="id420384"></a>
718<a class="indexterm" name="id420390"></a>
719On Solaris, you need to modify the <code class="filename">/etc/init.d/samba.server</code> startup script. It
720usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in
721<code class="filename">/usr/local/samba/bin</code>, the file could contains something like this:
722</p><p>
723 </p><pre class="programlisting">
724 ##
725 ## samba.server
726 ##
727
728 if [ ! -d /usr/bin ]
729 then # /usr not mounted
730 exit
731 fi
732
733 killproc() { # kill the named process(es)
734 pid=`/usr/bin/ps -e |
735 /usr/bin/grep -w $1 |
736 /usr/bin/sed -e 's/^ *//' -e 's/ .*//'`
737 [ "$pid" != "" ] &amp;&amp; kill $pid
738 }
739
740 # Start/stop processes required for Samba server
741
742 case "$1" in
743
744 'start')
745 #
746 # Edit these lines to suit your installation (paths, workgroup, host)
747 #
748 echo Starting SMBD
749 /usr/local/samba/bin/smbd -D -s \
750 /usr/local/samba/smb.conf
751
752 echo Starting NMBD
753 /usr/local/samba/bin/nmbd -D -l \
754 /usr/local/samba/var/log -s /usr/local/samba/smb.conf
755
756 echo Starting Winbind Daemon
757 /usr/local/samba/sbin/winbindd
758 ;;
759
760 'stop')
761 killproc nmbd
762 killproc smbd
763 killproc winbindd
764 ;;
765
766 *)
767 echo "Usage: /etc/init.d/samba.server { start | stop }"
768 ;;
769 esac
770</pre><p>
771Again, if you would like to run winbindd in dual daemon mode, replace:
772</p><pre class="programlisting">
773/usr/local/samba/sbin/winbindd
774</pre><p>
775in the script above with:
776</p><pre class="programlisting">
777/usr/local/samba/sbin/winbindd -D
778</pre><p>
779</p></div><div class="sect4" title="Restarting"><div class="titlepage"><div><div><h5 class="title"><a name="id420456"></a>Restarting</h5></div></div></div><p>
780<a class="indexterm" name="id420464"></a>
781<a class="indexterm" name="id420471"></a>
782If you restart the <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> daemons at this point, you
783should be able to connect to the Samba server as a domain member just as
784if you were a local user.
785</p></div></div><div class="sect3" title="Configure Winbind and PAM"><div class="titlepage"><div><div><h4 class="title"><a name="id420500"></a>Configure Winbind and PAM</h4></div></div></div><p>
786<a class="indexterm" name="id420508"></a>
787<a class="indexterm" name="id420514"></a>
788<a class="indexterm" name="id420521"></a>
789<a class="indexterm" name="id420528"></a>
790If you have made it this far, you know that <code class="literal">winbindd</code> and Samba are working together. If you
791want to use Winbind to provide authentication for other services, keep reading. The PAM configuration files
792need to be altered in this step. (Did you remember to make backups of your original
793<code class="filename">/etc/pam.d</code> files? If not, do it now.)
794</p><p>
795<a class="indexterm" name="id420552"></a>
796<a class="indexterm" name="id420559"></a>
797<a class="indexterm" name="id420566"></a>
798<a class="indexterm" name="id420572"></a>
799<a class="indexterm" name="id420579"></a>
800<a class="indexterm" name="id420586"></a>
801You will need a PAM module to use winbindd with these other services. This module will be compiled in the
802<code class="filename">../source/nsswitch</code> directory by invoking the command:
803</p><pre class="screen">
804<code class="prompt">root# </code><strong class="userinput"><code>make nsswitch/pam_winbind.so</code></strong>
805</pre><p>
806from the <code class="filename">../source</code> directory. The <code class="filename">pam_winbind.so</code> file should be
807copied to the location of your other PAM security modules. On my Red Hat system, this was the
808<code class="filename">/lib/security</code> directory. On Solaris, the PAM security modules reside in
809<code class="filename">/usr/lib/security</code>.
810</p><pre class="screen">
811<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</code></strong>
812</pre><p>
813</p><div class="sect4" title="Linux/FreeBSD-Specific PAM Configuration"><div class="titlepage"><div><div><h5 class="title"><a name="id420659"></a>Linux/FreeBSD-Specific PAM Configuration</h5></div></div></div><p>
814<a class="indexterm" name="id420667"></a>
815The <code class="filename">/etc/pam.d/samba</code> file does not need to be changed. I just left this file as it was:
816</p><pre class="programlisting">
817auth required /lib/security/pam_stack.so service=system-auth
818account required /lib/security/pam_stack.so service=system-auth
819</pre><p>
820<a class="indexterm" name="id420689"></a>
821<a class="indexterm" name="id420696"></a>
822<a class="indexterm" name="id420702"></a>
823<a class="indexterm" name="id420709"></a>
824<a class="indexterm" name="id420716"></a>
825<a class="indexterm" name="id420723"></a>
826<a class="indexterm" name="id420730"></a>
827<a class="indexterm" name="id420736"></a>
828<a class="indexterm" name="id420743"></a>
829The other services that I modified to allow the use of Winbind as an authentication service were the normal
830login on the console (or a terminal session), telnet logins, and ftp service. In order to enable these
831services, you may first need to change the entries in <code class="filename">/etc/xinetd.d</code> (or
832<code class="filename">/etc/inetd.conf</code>). Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this
833case you need to change the lines in <code class="filename">/etc/xinetd.d/telnet</code> and
834<code class="filename">/etc/xinetd.d/wu-ftp</code> from:
835</p><pre class="programlisting">
836 enable = no
837</pre><p>
838to
839</p><pre class="programlisting">
840 enable = yes
841</pre><p>
842<a class="indexterm" name="id420791"></a>
843<a class="indexterm" name="id420798"></a>
844<a class="indexterm" name="id420805"></a>
845For ftp services to work properly, you will also need to either have individual directories for the domain
846users already present on the server or change the home directory template to a general directory for all
847domain users. These can be easily set using the <code class="filename">smb.conf</code> global entry <a class="link" href="smb.conf.5.html#TEMPLATEHOMEDIR" target="_top">template homedir</a>.
848</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
849<a class="indexterm" name="id420837"></a>
850The directory in <a class="link" href="smb.conf.5.html#TEMPLATEHOMEDIR" target="_top">template homedir</a> is not created automatically! Use pam_mkhomedir or
851pre-create the directories of users to make sure users can log in on UNIX with their own home directory.
852</p></div><p>
853<a class="indexterm" name="id420859"></a>
854<a class="indexterm" name="id420865"></a>
855<a class="indexterm" name="id420872"></a>
856The <code class="filename">/etc/pam.d/ftp</code> file can be changed to allow Winbind ftp access in a manner similar to
857the <code class="filename">/etc/pam.d/samba</code>Samba file. My <code class="filename">/etc/pam.d/ftp</code> file was changed to look like this:
858</p><pre class="programlisting">
859auth required /lib/security/pam_listfile.so item=user sense=deny \
860 file=/etc/ftpusers onerr=succeed
861auth sufficient /lib/security/pam_winbind.so
862auth required /lib/security/pam_stack.so service=system-auth
863auth required /lib/security/pam_shells.so
864account sufficient /lib/security/pam_winbind.so
865account required /lib/security/pam_stack.so service=system-auth
866session required /lib/security/pam_stack.so service=system-auth
867</pre><p>
868<a class="indexterm" name="id420909"></a>
869The <code class="filename">/etc/pam.d/login</code> file can be changed in nearly the same way. It now looks like this:
870</p><pre class="programlisting">
871auth required /lib/security/pam_securetty.so
872auth sufficient /lib/security/pam_winbind.so
873auth sufficient /lib/security/pam_unix.so use_first_pass
874auth required /lib/security/pam_stack.so service=system-auth
875auth required /lib/security/pam_nologin.so
876account sufficient /lib/security/pam_winbind.so
877account required /lib/security/pam_stack.so service=system-auth
878password required /lib/security/pam_stack.so service=system-auth
879session required /lib/security/pam_stack.so service=system-auth
880session optional /lib/security/pam_console.so
881</pre><p>
882<a class="indexterm" name="id420933"></a>
883<a class="indexterm" name="id420940"></a>
884<a class="indexterm" name="id420947"></a>
885In this case, I added the </p><pre class="programlisting">auth sufficient /lib/security/pam_winbind.so</pre><p> lines
886as before, but also added the </p><pre class="programlisting">required pam_securetty.so</pre><p> above it to disallow
887root logins over the network. I also added a </p><pre class="programlisting">sufficient /lib/security/pam_unix.so
888use_first_pass</pre><p> line after the <code class="literal">winbind.so</code> line to get rid of annoying
889double prompts for passwords.
890</p></div><div class="sect4" title="Solaris-Specific Configuration"><div class="titlepage"><div><div><h5 class="title"><a name="id420982"></a>Solaris-Specific Configuration</h5></div></div></div><p>
891<a class="indexterm" name="id420990"></a>
892<a class="indexterm" name="id420996"></a>
893The <code class="filename">/etc/pam.conf</code> needs to be changed. I changed this file so my Domain
894users can log on both locally as well as with telnet. The following are the changes
895that I made. You can customize the <code class="filename">pam.conf</code> file as per your requirements, but
896be sure of those changes because in the worst case it will leave your system
897nearly impossible to boot.
898</p><pre class="programlisting">
899#
900#ident "@(#)pam.conf 1.14 99/09/16 SMI"
901#
902# Copyright (c) 1996-1999, Sun Microsystems, Inc.
903# All Rights Reserved.
904#
905# PAM configuration
906#
907# Authentication management
908#
909login auth required /usr/lib/security/pam_winbind.so
910login auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
911login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass
912#
913rlogin auth sufficient /usr/lib/security/pam_winbind.so
914rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1
915rlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
916#
917dtlogin auth sufficient /usr/lib/security/pam_winbind.so
918dtlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
919#
920rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1
921other auth sufficient /usr/lib/security/pam_winbind.so
922other auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
923#
924# Account management
925#
926login account sufficient /usr/lib/security/pam_winbind.so
927login account requisite /usr/lib/security/$ISA/pam_roles.so.1
928login account required /usr/lib/security/$ISA/pam_unix.so.1
929#
930dtlogin account sufficient /usr/lib/security/pam_winbind.so
931dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1
932dtlogin account required /usr/lib/security/$ISA/pam_unix.so.1
933#
934other account sufficient /usr/lib/security/pam_winbind.so
935other account requisite /usr/lib/security/$ISA/pam_roles.so.1
936other account required /usr/lib/security/$ISA/pam_unix.so.1
937#
938# Session management
939#
940other session required /usr/lib/security/$ISA/pam_unix.so.1
941#
942# Password management
943#
944#other password sufficient /usr/lib/security/pam_winbind.so
945other password required /usr/lib/security/$ISA/pam_unix.so.1
946dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1
947#
948# Support for Kerberos V5 authentication (uncomment to use Kerberos)
949#
950#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
951#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
952#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
953#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
954#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1
955#other account optional /usr/lib/security/$ISA/pam_krb5.so.1
956#other session optional /usr/lib/security/$ISA/pam_krb5.so.1
957#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
958</pre><p>
959<a class="indexterm" name="id421065"></a>
960I also added a <em class="parameter"><code>try_first_pass</code></em> line after the <code class="filename">winbind.so</code>
961line to get rid of annoying double prompts for passwords.
962</p><p>
963Now restart your Samba and try connecting through your application that you
964configured in the pam.conf.
965</p></div></div></div></div><div class="sect1" title="Conclusion"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id421094"></a>Conclusion</h2></div></div></div><p>
966<a class="indexterm" name="id421102"></a>
967<a class="indexterm" name="id421108"></a>
968<a class="indexterm" name="id421115"></a>
969<a class="indexterm" name="id421121"></a>
970<a class="indexterm" name="id421128"></a>
971The Winbind system, through the use of the NSS, PAMs, and appropriate Microsoft RPC calls, have allowed us to
972provide seamless integration of Microsoft Windows NT domain users on a UNIX system. The result is a great
973reduction in the administrative cost of running a mixed UNIX and NT network.
974</p></div><div class="sect1" title="Common Errors"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id421140"></a>Common Errors</h2></div></div></div><p>
975 Winbind has a number of limitations in its current released version that we hope to overcome in future releases:
976 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
977 Winbind is currently only available for the Linux, Solaris, AIX, and IRIX operating systems, although
978 ports to other operating systems are certainly possible. For such ports to be feasible, we require the C
979 library of the target operating system to support the NSS and PAM systems. This is becoming more common as NSS
980 and PAM gain support among UNIX vendors.
981 </p></li><li class="listitem"><p>
982 The mappings of Windows NT RIDs to UNIX IDs is not made algorithmically and depends on the order in
983 which unmapped users or groups are seen by Winbind. It may be difficult to recover the mappings of RID to UNIX
984 ID if the file containing this information is corrupted or destroyed.
985 </p></li><li class="listitem"><p>
986 Currently the Winbind PAM module does not take into account possible workstation and logon time
987 restrictions that may be set for Windows NT users; this is instead up to the PDC to enforce.
988 </p></li></ul></div><div class="sect2" title="NSCD Problem Warning"><div class="titlepage"><div><div><h3 class="title"><a name="id421173"></a>NSCD Problem Warning</h3></div></div></div><div class="warning" title="Warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
989 Do not under any circumstances run <code class="literal">nscd</code> on any system
990 on which <code class="literal">winbindd</code> is running.
991 </p></div><p>
992 If <code class="literal">nscd</code> is running on the UNIX/Linux system, then
993 even though NSSWITCH is correctly configured, it will not be possible to resolve
994 domain users and groups for file and directory controls.
995 </p></div><div class="sect2" title="Winbind Is Not Resolving Users and Groups"><div class="titlepage"><div><div><h3 class="title"><a name="id421207"></a>Winbind Is Not Resolving Users and Groups</h3></div></div></div><p><span class="quote">&#8220;<span class="quote">
996 My <code class="filename">smb.conf</code> file is correctly configured. I have specified <a class="link" href="smb.conf.5.html#IDMAPUID" target="_top">idmap uid = 12000</a>,
997 and <a class="link" href="smb.conf.5.html#IDMAPGID" target="_top">idmap gid = 3000-3500</a> and <code class="literal">winbind</code> is running.
998 When I do the following, it all works fine.
999 </span>&#8221;</span></p><pre class="screen">
1000<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -u</code></strong>
1001MIDEARTH\maryo
1002MIDEARTH\jackb
1003MIDEARTH\ameds
1004...
1005MIDEARTH\root
1006
1007<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -g</code></strong>
1008MIDEARTH\Domain Users
1009MIDEARTH\Domain Admins
1010MIDEARTH\Domain Guests
1011...
1012MIDEARTH\Accounts
1013
1014<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong>
1015root:x:0:0:root:/root:/bin/bash
1016bin:x:1:1:bin:/bin:/bin/bash
1017...
1018maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false
1019</pre><p><span class="quote">&#8220;<span class="quote">
1020But the following command just fails:
1021</span>&#8221;</span>
1022</p><pre class="screen">
1023<code class="prompt">root# </code><strong class="userinput"><code>chown maryo a_file</code></strong>
1024chown: `maryo': invalid user
1025</pre><p>
1026<span class="quote">&#8220;<span class="quote">
1027This is driving me nuts! What can be wrong?
1028</span>&#8221;</span></p><p>
1029Same problem as the one above.
1030Your system is likely running <code class="literal">nscd</code>, the name service
1031caching daemon. Shut it down, do not restart it! You will find your problem resolved.
1032Alternately, fix the operation of nscd to resolve the problem.
1033</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="VFS.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="optional.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="AdvancedNetworkManagement.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 23. Stackable VFS modules </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 25. Advanced Network Management</td></tr></table></div></body></html>
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