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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#id415432">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="winbind.html#id415759">Introduction</a></span></dt><dt><span class="sect1"><a href="winbind.html#id415837">What Winbind Provides</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id415975">Target Uses</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416015">Handling of Foreign SIDs</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id416127">How Winbind Works</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id416174">Microsoft Remote Procedure Calls</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416252">Microsoft Active Directory Services</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416296">Name Service Switch</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416508">Pluggable Authentication Modules</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416649">User and Group ID Allocation</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416717">Result Caching</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id416767">Installation and Configuration</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id416773">Introduction</a></span></dt><dt><span class="sect2"><a href="winbind.html#id416880">Requirements</a></span></dt><dt><span class="sect2"><a href="winbind.html#id417022">Testing Things Out</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id419254">Conclusion</a></span></dt><dt><span class="sect1"><a href="winbind.html#id419300">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id419333">NSCD Problem Warning</a></span></dt><dt><span class="sect2"><a href="winbind.html#id419367">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="id415432"></a>Features and Benefits</h2></div></div></div><p>
2<a class="indexterm" name="id415440"></a>
3<a class="indexterm" name="id415447"></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="id415462"></a>
9<a class="indexterm" name="id415469"></a>
10<a class="indexterm" name="id415475"></a>
11<a class="indexterm" name="id415482"></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="id415495"></a>
18<a class="indexterm" name="id415504"></a>
19<a class="indexterm" name="id415510"></a>
20<a class="indexterm" name="id415517"></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="id415541"></a>
31<a class="indexterm" name="id415547"></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="id415560"></a>
37<a class="indexterm" name="id415567"></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="id415579"></a>
41<a class="indexterm" name="id415585"></a>
42<a class="indexterm" name="id415592"></a>
43<a class="indexterm" name="id415598"></a>
44<a class="indexterm" name="id415605"></a>
45<a class="indexterm" name="id415612"></a>
46<a class="indexterm" name="id415619"></a>
47 Winbind maintains a database called winbind_idmap.tdb in which it stores
48 mappings between UNIX UIDs, GIDs, and NT SIDs. This mapping is used only
49 for users and groups that do not have a local UID/GID. It stores the UID/GID
50 allocated from the idmap uid/gid range that it has mapped to the NT SID.
51 If <em class="parameter"><code>idmap backend</code></em> has been specified as <code class="constant">ldap:ldap://hostname[:389]</code>,
52 then instead of using a local mapping, Winbind will obtain this information
53 from the LDAP database.
54 </p></li></ul></div><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
55 <a class="indexterm" name="id415647"></a>
56 <a class="indexterm" name="id415654"></a>
57<a class="indexterm" name="id415663"></a>
58<a class="indexterm" name="id415670"></a>
59<a class="indexterm" name="id415677"></a>
60<a class="indexterm" name="id415683"></a>
61 If <code class="literal">winbindd</code> is not running, smbd (which calls <code class="literal">winbindd</code>) will fall back to
62 using purely local information from <code class="filename">/etc/passwd</code> and <code class="filename">/etc/group</code> and no dynamic
63 mapping will be used. On an operating system that has been enabled with the NSS,
64 the resolution of user and group information will be accomplished via NSS.
65 </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="id415759"></a>Introduction</h2></div></div></div><p>It is well known that UNIX and Microsoft Windows NT have
66 different models for representing user and group information and
67 use different technologies for implementing them. This fact has
68 made it difficult to integrate the two systems in a satisfactory
69 manner.</p><p>
70<a class="indexterm" name="id415772"></a>
71<a class="indexterm" name="id415779"></a>
72 One common solution in use today has been to create
73 identically named user accounts on both the UNIX and Windows systems
74 and use the Samba suite of programs to provide file and print services
75 between the two. This solution is far from perfect, however, because
76 adding and deleting users on both sets of machines becomes a chore,
77 and two sets of passwords are required both of which
78 can lead to synchronization problems between the UNIX and Windows
79 systems and confusion for users.</p><p>We divide the unified logon problem for UNIX machines into
80 three smaller problems:</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>Obtaining Windows NT user and group information.
81 </p></li><li class="listitem"><p>Authenticating Windows NT users.
82 </p></li><li class="listitem"><p>Password changing for Windows NT users.
83 </p></li></ul></div><p>
84<a class="indexterm" name="id415818"></a>
85<a class="indexterm" name="id415824"></a>
86 Ideally, a prospective solution to the unified logon problem
87 would satisfy all the above components without duplication of
88 information on the UNIX machines and without creating additional
89 tasks for the system administrator when maintaining users and
90 groups on either system. The Winbind system provides a simple
91 and elegant solution to all three components of the unified logon
92 problem.</p></div><div class="sect1" title="What Winbind Provides"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id415837"></a>What Winbind Provides</h2></div></div></div><p>
93<a class="indexterm" name="id415845"></a>
94<a class="indexterm" name="id415852"></a>
95<a class="indexterm" name="id415858"></a>
96<a class="indexterm" name="id415865"></a>
97 Winbind unifies UNIX and Windows NT account management by
98 allowing a UNIX box to become a full member of an NT domain. Once
99 this is done, the UNIX box will see NT users and groups as if
100 they were <span class="quote">&#8220;<span class="quote">native</span>&#8221;</span> UNIX users and groups, allowing the NT domain
101 to be used in much the same manner that NIS+ is used within
102 UNIX-only environments.</p><p>
103<a class="indexterm" name="id415882"></a>
104<a class="indexterm" name="id415888"></a>
105<a class="indexterm" name="id415895"></a>
106<a class="indexterm" name="id415902"></a>
107 The end result is that whenever a
108 program on the UNIX machine asks the operating system to look up
109 a user or group name, the query will be resolved by asking the
110 NT domain controller for the specified domain to do the lookup.
111 Because Winbind hooks into the operating system at a low level
112 (via the NSS name resolution modules in the C library), this
113 redirection to the NT domain controller is completely
114 transparent.</p><p>
115<a class="indexterm" name="id415916"></a>
116<a class="indexterm" name="id415922"></a>
117 Users on the UNIX machine can then use NT user and group
118 names as they would <span class="quote">&#8220;<span class="quote">native</span>&#8221;</span> UNIX names. They can chown files
119 so they are owned by NT domain users or even login to the
120 UNIX machine and run a UNIX X-Window session as a domain user.</p><p>
121<a class="indexterm" name="id415938"></a>
122 The only obvious indication that Winbind is being used is
123 that user and group names take the form <code class="constant">DOMAIN\user</code> and
124 <code class="constant">DOMAIN\group</code>. This is necessary because it allows Winbind to determine
125 that redirection to a domain controller is wanted for a particular
126 lookup and which trusted domain is being referenced.</p><p>
127<a class="indexterm" name="id415958"></a>
128<a class="indexterm" name="id415965"></a>
129 Additionally, Winbind provides an authentication service that hooks into the PAM system
130 to provide authentication via an NT domain to any PAM-enabled
131 applications. This capability solves the problem of synchronizing
132 passwords between systems, since all passwords are stored in a single
133 location (on the domain controller).</p><div class="sect2" title="Target Uses"><div class="titlepage"><div><div><h3 class="title"><a name="id415975"></a>Target Uses</h3></div></div></div><p>
134<a class="indexterm" name="id415983"></a>
135 Winbind is targeted at organizations that have an
136 existing NT-based domain infrastructure into which they wish
137 to put UNIX workstations or servers. Winbind will allow these
138 organizations to deploy UNIX workstations without having to
139 maintain a separate account infrastructure. This greatly
140 simplifies the administrative overhead of deploying UNIX
141 workstations into an NT-based organization.</p><p>
142<a class="indexterm" name="id415997"></a>
143<a class="indexterm" name="id416003"></a>
144 Another interesting way in which we expect Winbind to
145 be used is as a central part of UNIX-based appliances. Appliances
146 that provide file and print services to Microsoft-based networks
147 will be able to use Winbind to provide seamless integration of
148 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="id416015"></a>Handling of Foreign SIDs</h3></div></div></div><p>
149<a class="indexterm" name="id416023"></a>
150 The term <span class="emphasis"><em>foreign SID</em></span> is often met with the reaction that it
151 is not relevant to a particular environment. The following documents an interchange
152 that took place on the Samba mailing list. It is a good example of the confusion
153 often expressed regarding the use of winbind.
154 </p><p>
155<a class="indexterm" name="id416039"></a>
156 Fact: Winbind is needed to handle users who use workstations that are NOT part
157 of the local domain.
158 </p><p>
159<a class="indexterm" name="id416050"></a>
160 Response: <span class="quote">&#8220;<span class="quote">Why? I've used Samba with workstations that are not part of my domains
161 lots of times without using winbind. I thought winbind was for using Samba as a member server
162 in a domain controlled by another Samba/Windows PDC.</span>&#8221;</span>
163 </p><p>
164<a class="indexterm" name="id416065"></a>
165<a class="indexterm" name="id416072"></a>
166<a class="indexterm" name="id416078"></a>
167 If the Samba server will be accessed from a domain other than the local Samba domain, or
168 if there will be access from machines that are not local domain members, winbind will
169 permit the allocation of UIDs and GIDs from the assigned pool that will keep the identity
170 of the foreign user separate from users that are members of the Samba domain.
171 </p><p>
172<a class="indexterm" name="id416091"></a>
173<a class="indexterm" name="id416098"></a>
174<a class="indexterm" name="id416104"></a>
175<a class="indexterm" name="id416111"></a>
176 This means that winbind is eminently useful in cases where a single
177 Samba PDC on a local network is combined with both domain member and domain non-member workstations.
178 If winbind is not used, the user george on a Windows workstation that is not a domain
179 member will be able to access the files of a user called george in the account database
180 of the Samba server that is acting as a PDC. When winbind is used, the default condition
181 is that the local user george will be treated as the account DOMAIN\george and the
182 foreign (non-member of the domain) account will be treated as MACHINE\george because
183 each has a different SID.
184 </p></div></div><div class="sect1" title="How Winbind Works"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id416127"></a>How Winbind Works</h2></div></div></div><p>
185<a class="indexterm" name="id416135"></a>
186<a class="indexterm" name="id416141"></a>
187<a class="indexterm" name="id416148"></a>
188<a class="indexterm" name="id416155"></a>
189 The Winbind system is designed around a client/server
190 architecture. A long-running <code class="literal">winbindd</code> daemon
191 listens on a UNIX domain socket waiting for requests
192 to arrive. These requests are generated by the NSS and PAM
193 clients and are processed sequentially.</p><p>The technologies used to implement Winbind are described
194 in detail below.</p><div class="sect2" title="Microsoft Remote Procedure Calls"><div class="titlepage"><div><div><h3 class="title"><a name="id416174"></a>Microsoft Remote Procedure Calls</h3></div></div></div><p>
195<a class="indexterm" name="id416182"></a>
196<a class="indexterm" name="id416192"></a>
197<a class="indexterm" name="id416198"></a>
198<a class="indexterm" name="id416205"></a>
199<a class="indexterm" name="id416212"></a>
200 Over the last few years, efforts have been underway by various Samba Team members to implement various aspects of
201 the Microsoft Remote Procedure Call (MSRPC) system. This system is used for most network-related operations
202 between Windows NT machines, including remote management, user authentication, and print spooling. Although
203 initially this work was done to aid the implementation of Primary Domain Controller (PDC) functionality in
204 Samba, it has also yielded a body of code that can be used for other purposes.
205 </p><p>
206<a class="indexterm" name="id416226"></a>
207<a class="indexterm" name="id416233"></a>
208<a class="indexterm" name="id416240"></a>
209 Winbind uses various MSRPC calls to enumerate domain users and groups and to obtain detailed information about
210 individual users or groups. Other MSRPC calls can be used to authenticate NT domain users and to change user
211 passwords. By directly querying a Windows PDC for user and group information, Winbind maps the NT account
212 information onto UNIX user and group names.
213 </p></div><div class="sect2" title="Microsoft Active Directory Services"><div class="titlepage"><div><div><h3 class="title"><a name="id416252"></a>Microsoft Active Directory Services</h3></div></div></div><p>
214<a class="indexterm" name="id416260"></a>
215<a class="indexterm" name="id416267"></a>
216<a class="indexterm" name="id416274"></a>
217<a class="indexterm" name="id416280"></a>
218 Since late 2001, Samba has gained the ability to interact with Microsoft Windows 2000 using its <span class="quote">&#8220;<span class="quote">native
219 mode</span>&#8221;</span> protocols rather than the NT4 RPC services. Using LDAP and Kerberos, a domain member running
220 Winbind can enumerate users and groups in exactly the same way as a Windows 200x client would, and in so doing
221 provide a much more efficient and effective Winbind implementation.
222 </p></div><div class="sect2" title="Name Service Switch"><div class="titlepage"><div><div><h3 class="title"><a name="id416296"></a>Name Service Switch</h3></div></div></div><p>
223<a class="indexterm" name="id416304"></a>
224<a class="indexterm" name="id416310"></a>
225<a class="indexterm" name="id416317"></a>
226<a class="indexterm" name="id416324"></a>
227 The NSS is a feature that is present in many UNIX operating systems. It allows system
228 information such as hostnames, mail aliases, and user information
229 to be resolved from different sources. For example, a standalone
230 UNIX workstation may resolve system information from a series of
231 flat files stored on the local file system. A networked workstation
232 may first attempt to resolve system information from local files,
233 and then consult an NIS database for user information or a DNS server
234 for hostname information.</p><p>
235<a class="indexterm" name="id416338"></a>
236<a class="indexterm" name="id416345"></a>
237<a class="indexterm" name="id416351"></a>
238<a class="indexterm" name="id416358"></a>
239<a class="indexterm" name="id416365"></a>
240 The NSS application programming interface allows Winbind to present itself as a source of system
241 information when resolving UNIX usernames and groups. Winbind uses this interface and information obtained
242 from a Windows NT server using MSRPC calls to provide a new source of account enumeration. Using standard UNIX
243 library calls, you can enumerate the users and groups on a UNIX machine running Winbind and see all users and
244 groups in an NT domain plus any trusted domain as though they were local users and groups.
245 </p><p>
246<a class="indexterm" name="id416380"></a>
247<a class="indexterm" name="id416386"></a>
248<a class="indexterm" name="id416393"></a>
249 The primary control file for NSS is <code class="filename">/etc/nsswitch.conf</code>. When a UNIX application
250 makes a request to do a lookup, the C library looks in <code class="filename">/etc/nsswitch.conf</code> for a line that
251 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
252 user or group names are looked up. This config line specifies which implementations of that service should be
253 tried and in what order. If the passwd config line is:
254</p><pre class="screen">
255passwd: files example
256</pre><p>
257<a class="indexterm" name="id416424"></a>
258<a class="indexterm" name="id416431"></a>
259<a class="indexterm" name="id416438"></a>
260 then the C library will first load a module called <code class="filename">/lib/libnss_files.so</code> followed
261 by the module <code class="filename">/lib/libnss_example.so</code>. The C library will dynamically load each of these
262 modules in turn and call resolver functions within the modules to try to resolve the request. Once the request
263 is resolved, the C library returns the result to the application.
264 </p><p>
265<a class="indexterm" name="id416462"></a>
266<a class="indexterm" name="id416469"></a>
267<a class="indexterm" name="id416476"></a>
268 This NSS interface provides an easy way for Winbind to hook into the operating system. All that needs
269 to be done is to put <code class="filename">libnss_winbind.so</code> in <code class="filename">/lib/</code> then add
270 <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
271 will then call Winbind to resolve user and group names.
272 </p></div><div class="sect2" title="Pluggable Authentication Modules"><div class="titlepage"><div><div><h3 class="title"><a name="id416508"></a>Pluggable Authentication Modules</h3></div></div></div><p>
273<a class="indexterm" name="id416516"></a>
274<a class="indexterm" name="id416522"></a>
275<a class="indexterm" name="id416529"></a>
276<a class="indexterm" name="id416536"></a>
277 PAMs provide a system for abstracting authentication and authorization technologies. With a PAM
278 module, it is possible to specify different authentication methods for different system applications without
279 having to recompile these applications. PAM is also useful for implementing a particular policy for
280 authorization. For example, a system administrator may only allow console logins from users stored in the
281 local password file but only allow users resolved from an NIS database to log in over the network.
282 </p><p>
283<a class="indexterm" name="id416551"></a>
284<a class="indexterm" name="id416557"></a>
285<a class="indexterm" name="id416564"></a>
286<a class="indexterm" name="id416571"></a>
287<a class="indexterm" name="id416578"></a>
288 Winbind uses the authentication management and password management PAM interface to integrate Windows
289 NT users into a UNIX system. This allows Windows NT users to log in to a UNIX machine and be authenticated
290 against a suitable PDC. These users can also change their passwords and have this change take effect directly
291 on the PDC.
292 </p><p>
293<a class="indexterm" name="id416590"></a>
294<a class="indexterm" name="id416597"></a>
295<a class="indexterm" name="id416604"></a>
296<a class="indexterm" name="id416610"></a>
297 PAM is configured by providing control files in the directory <code class="filename">/etc/pam.d/</code> for
298 each of the services that require authentication. When an authentication request is made by an application,
299 the PAM code in the C library looks up this control file to determine what modules to load to do the
300 authentication check and in what order. This interface makes adding a new authentication service for Winbind
301 very easy: simply copy the <code class="filename">pam_winbind.so</code> module to <code class="filename">/lib/security/</code>,
302 and the PAM control files for relevant services are updated to allow authentication via Winbind. See the PAM
303 documentation in <a class="link" href="pam.html" title="Chapter 28. PAM-Based Distributed Authentication">PAM-Based Distributed Authentication</a>, for more information.
304 </p></div><div class="sect2" title="User and Group ID Allocation"><div class="titlepage"><div><div><h3 class="title"><a name="id416649"></a>User and Group ID Allocation</h3></div></div></div><p>
305<a class="indexterm" name="id416657"></a>
306<a class="indexterm" name="id416663"></a>
307<a class="indexterm" name="id416670"></a>
308 When a user or group is created under Windows NT/200x, it is allocated a numerical relative identifier
309 (RID). This is slightly different from UNIX, which has a range of numbers that are used to identify users and
310 the same range used to identify groups. It is Winbind's job to convert RIDs to UNIX ID numbers and vice versa.
311 When Winbind is configured, it is given part of the UNIX user ID space and a part of the UNIX group ID space
312 in which to store Windows NT users and groups. If a Windows NT user is resolved for the first time, it is
313 allocated the next UNIX ID from the range. The same process applies for Windows NT groups. Over time, Winbind
314 will have mapped all Windows NT users and groups to UNIX user IDs and group IDs.
315 </p><p>
316<a class="indexterm" name="id416686"></a>
317<a class="indexterm" name="id416693"></a>
318<a class="indexterm" name="id416700"></a>
319<a class="indexterm" name="id416706"></a>
320 The results of this mapping are stored persistently in an ID mapping database held in a tdb database.
321 This ensures that RIDs are mapped to UNIX IDs in a consistent way.
322 </p></div><div class="sect2" title="Result Caching"><div class="titlepage"><div><div><h3 class="title"><a name="id416717"></a>Result Caching</h3></div></div></div><p>
323<a class="indexterm" name="id416724"></a>
324<a class="indexterm" name="id416731"></a>
325<a class="indexterm" name="id416738"></a>
326<a class="indexterm" name="id416745"></a>
327<a class="indexterm" name="id416751"></a>
328 An active directory system can generate a lot of user and group name lookups. To reduce the network
329 cost of these lookups, Winbind uses a caching scheme based on the SAM sequence number supplied by NT domain
330 controllers. User or group information returned by a PDC is cached by Winbind along with a sequence number
331 also returned by the PDC. This sequence number is incremented by Windows NT whenever any user or group
332 information is modified. If a cached entry has expired, the sequence number is requested from the PDC and
333 compared against the sequence number of the cached entry. If the sequence numbers do not match, then the
334 cached information is discarded and up-to-date information is requested directly from the PDC.
335 </p></div></div><div class="sect1" title="Installation and Configuration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id416767"></a>Installation and Configuration</h2></div></div></div><div class="sect2" title="Introduction"><div class="titlepage"><div><div><h3 class="title"><a name="id416773"></a>Introduction</h3></div></div></div><p>
336<a class="indexterm" name="id416781"></a>
337<a class="indexterm" name="id416787"></a>
338<a class="indexterm" name="id416794"></a>
339This section describes the procedures used to get Winbind up and running. Winbind is capable of providing
340access and authentication control for Windows Domain users through an NT or Windows 200x PDC for regular
341services, such as telnet and ftp, as well for Samba services.
342</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
343 <span class="emphasis"><em>Why should I do this?</em></span>
344 </p><p>
345<a class="indexterm" name="id416817"></a>
346<a class="indexterm" name="id416824"></a>
347<a class="indexterm" name="id416831"></a>
348<a class="indexterm" name="id416838"></a>
349This allows the Samba administrator to rely on the authentication mechanisms on the Windows NT/200x PDC
350for the authentication of domain members. Windows NT/200x users no longer need to have separate accounts on
351the Samba server.
352 </p></li><li class="listitem"><p>
353 <span class="emphasis"><em>Who should be reading this document?</em></span>
354 </p><p>
355<a class="indexterm" name="id416860"></a>
356<a class="indexterm" name="id416866"></a>
357This document is designed for system administrators. If you are implementing Samba on a file server and wish
358to (fairly easily) integrate existing Windows NT/200x users from your PDC onto the Samba server, this document
359is for you.
360 </p></li></ul></div></div><div class="sect2" title="Requirements"><div class="titlepage"><div><div><h3 class="title"><a name="id416880"></a>Requirements</h3></div></div></div><p>
361<a class="indexterm" name="id416887"></a>
362<a class="indexterm" name="id416894"></a>
363<a class="indexterm" name="id416901"></a>
364If you have a Samba configuration file that you are currently using, <span class="emphasis"><em>BACK IT UP!</em></span>
365If your system already uses PAM, <span class="emphasis"><em>back up the <code class="filename">/etc/pam.d</code> directory
366contents!</em></span> If you haven't already made a boot disk, <span class="emphasis"><em>MAKE ONE NOW!</em></span>
367</p><p>
368<a class="indexterm" name="id416929"></a>
369<a class="indexterm" name="id416936"></a>
370<a class="indexterm" name="id416942"></a>
371Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's
372why you want to be able to boot back into your machine in single-user mode and restore your
373<code class="filename">/etc/pam.d</code> to the original state it was in if you get frustrated with the
374way things are going.
375</p><p>
376<a class="indexterm" name="id416961"></a>
377<a class="indexterm" name="id416967"></a>
378The 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
379instructions on downloading the source code.
380</p><p>
381<a class="indexterm" name="id416985"></a>
382<a class="indexterm" name="id416992"></a>
383<a class="indexterm" name="id416999"></a>
384<a class="indexterm" name="id417005"></a>
385To allow domain users the ability to access Samba shares and files, as well as potentially other services
386provided by your Samba machine, PAM must be set up properly on your
387machine. In order to compile the Winbind modules, you should have at least the PAM development libraries installed
388on your system. Please refer to the PAM Web site <a class="ulink" href="http://www.kernel.org/pub/linux/libs/pam/" target="_top">http://www.kernel.org/pub/linux/libs/pam/</a>.
389</p></div><div class="sect2" title="Testing Things Out"><div class="titlepage"><div><div><h3 class="title"><a name="id417022"></a>Testing Things Out</h3></div></div></div><p>
390<a class="indexterm" name="id417029"></a>
391<a class="indexterm" name="id417036"></a>
392<a class="indexterm" name="id417043"></a>
393<a class="indexterm" name="id417050"></a>
394<a class="indexterm" name="id417057"></a>
395Before starting, it is probably best to kill off all the Samba-related daemons running on your server.
396Kill 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,
397make sure that you have the standard PAM package that supplies the <code class="filename">/etc/pam.d</code>
398directory structure, including the PAM modules that are used by PAM-aware services, several PAM libraries,
399and the <code class="filename">/usr/doc</code> and <code class="filename">/usr/man</code> entries for PAM. Winbind is built
400better in Samba if the pam-devel package is also installed. This package includes the header files
401needed to compile PAM-aware applications.
402</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="id417104"></a>Configure <code class="filename">nsswitch.conf</code> and the Winbind Libraries on Linux and Solaris</h4></div></div></div><p>
403<a class="indexterm" name="id417118"></a>
404<a class="indexterm" name="id417124"></a>
405<a class="indexterm" name="id417131"></a>
406<a class="indexterm" name="id417138"></a>
407PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install
408the <code class="filename">pam-devel</code> libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3
409may auto-install the Winbind files into their correct locations on your system, so before you get too far down
410the track, be sure to check if the following configuration is really
411necessary. You may only need to configure
412<code class="filename">/etc/nsswitch.conf</code>.
413</p><p>
414The libraries needed to run the <span class="application">winbindd</span> daemon through nsswitch need to be copied to their proper locations:
415</p><p>
416<a class="indexterm" name="id417173"></a>
417</p><pre class="screen">
418<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/libnss_winbind.so /lib</code></strong>
419</pre><p>
420</p><p>
421I also found it necessary to make the following symbolic link:
422</p><p>
423<code class="prompt">root# </code> <strong class="userinput"><code>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</code></strong>
424</p><p>And, in the case of Sun Solaris:
425<a class="indexterm" name="id417219"></a>
426</p><pre class="screen">
427<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_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.1</code></strong>
429<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</code></strong>
430</pre><p>
431</p><p>
432<a class="indexterm" name="id417266"></a>
433As root, edit <code class="filename">/etc/nsswitch.conf</code> to allow user and group entries to be visible from the
434<span class="application">winbindd</span> daemon. My <code class="filename">/etc/nsswitch.conf</code> file looked like this after editing:
435</p><pre class="programlisting">
436passwd: files winbind
437shadow: files
438group: files winbind
439</pre><p>
440<a class="indexterm" name="id417300"></a>
441<a class="indexterm" name="id417307"></a>
442<a class="indexterm" name="id417314"></a>
443<a class="indexterm" name="id417321"></a>
444<a class="indexterm" name="id417328"></a>
445The libraries needed by the <code class="literal">winbindd</code> daemon will be automatically
446entered into the <code class="literal">ldconfig</code> cache the next time
447your system reboots, but it is faster (and you do not need to reboot) if you do it manually:
448</p><pre class="screen">
449<code class="prompt">root# </code><strong class="userinput"><code>/sbin/ldconfig -v | grep winbind</code></strong>
450</pre><p>
451This makes <code class="filename">libnss_winbind</code> available to winbindd and reports the current
452search path that is used by the dynamic link loader. The use of the <code class="literal">grep</code>
453filters the output of the <code class="literal">ldconfig</code> command so that we may see proof that
454this library is indeed recognized by the dynamic link loader.
455</p><p>
456<a class="indexterm" name="id417387"></a>
457<a class="indexterm" name="id417394"></a>
458<a class="indexterm" name="id417400"></a>
459<a class="indexterm" name="id417407"></a>
460<a class="indexterm" name="id417414"></a>
461The Sun Solaris dynamic link loader management tool is called <code class="literal">crle</code>. The
462use of this tool is necessary to instruct the dynamic link loader to search directories that
463contain library files that were not supplied as part of the original operating system platform.
464The following example shows how to use this tool to add the directory <code class="filename">/usr/local/lib</code>
465to the dynamic link loader's search path:
466</p><pre class="screen">
467<code class="prompt">root# </code> crle -u -l /usr/lib:/usr/local/lib
468</pre><p>
469When executed without arguments, <code class="literal">crle</code> reports the current dynamic
470link loader configuration. This is demonstrated here:
471</p><pre class="screen">
472<code class="prompt">root# </code> crle
473
474Configuration file [version 4]: /var/ld/ld.config
475 Default Library Path (ELF): /lib:/usr/lib:/usr/local/lib
476 Trusted Directories (ELF): /lib/secure:/usr/lib/secure (system default)
477
478Command line:
479 crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/local/lib
480</pre><p>
481From this it is apparent that the <code class="filename">/usr/local/lib</code> directory is included
482in the search dynamic link libraries in order to satisfy object module dependencies.
483</p></div><div class="sect3" title="NSS Winbind on AIX"><div class="titlepage"><div><div><h4 class="title"><a name="id417478"></a>NSS Winbind on AIX</h4></div></div></div><p>(This section is only for those running AIX.)</p><p>
484<a class="indexterm" name="id417489"></a>
485<a class="indexterm" name="id417496"></a>
486<a class="indexterm" name="id417502"></a>
487<a class="indexterm" name="id417509"></a>
488<a class="indexterm" name="id417516"></a>
489<a class="indexterm" name="id417523"></a>
490The Winbind AIX identification module gets built as <code class="filename">libnss_winbind.so</code> in the
491nsswitch directory of the Samba source. This file can be copied to <code class="filename">/usr/lib/security</code>,
492and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following:
493</p><pre class="programlisting">
494WINBIND:
495 program = /usr/lib/security/WINBIND
496 options = authonly
497</pre><p>
498can then be added to <code class="filename">/usr/lib/security/methods.cfg</code>. This module only supports
499identification, but there have been reports of success using the standard Winbind PAM module for
500authentication. Use caution configuring loadable authentication modules, since misconfiguration can make
501it impossible to log on to the system. Information regarding the AIX authentication module API can
502be found in the <span class="quote">&#8220;<span class="quote">Kernel Extensions and Device Support Programming Concepts for AIX</span>&#8221;</span> document that
503describes 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">
504Loadable Authentication Module Programming Interface</a> for AIX. Further information on administering the modules
505can 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
506Management Guide: Operating System and Devices.</a>
507</p></div><div class="sect3" title="Configure smb.conf"><div class="titlepage"><div><div><h4 class="title"><a name="id417580"></a>Configure smb.conf</h4></div></div></div><p>
508<a class="indexterm" name="id417587"></a>
509<a class="indexterm" name="id417594"></a>
510<a class="indexterm" name="id417601"></a>
511Several parameters are needed in the <code class="filename">smb.conf</code> file to control the behavior of <span class="application">winbindd</span>. These
512are 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.
513</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="id417672"></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="id417687"></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="id417703"></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="id417718"></a><em class="parameter"><code>winbind enum users = yes</code></em></td></tr><tr><td><a class="indexterm" name="id417729"></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="id417745"></a><em class="parameter"><code>template homedir = /home/winnt/%D/%U</code></em></td></tr><tr><td><a class="indexterm" name="id417757"></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="id417770"></a>Join the Samba Server to the PDC Domain</h4></div></div></div><p>
514<a class="indexterm" name="id417778"></a>
515<a class="indexterm" name="id417785"></a>
516<a class="indexterm" name="id417792"></a>
517All machines that will participate in domain security should be members of
518the domain. This applies also to the PDC and all BDCs.
519</p><p>
520<a class="indexterm" name="id417802"></a>
521<a class="indexterm" name="id417809"></a>
522<a class="indexterm" name="id417816"></a>
523<a class="indexterm" name="id417827"></a>
524<a class="indexterm" name="id417834"></a>
525<a class="indexterm" name="id417840"></a>
526<a class="indexterm" name="id417847"></a>
527<a class="indexterm" name="id417854"></a>
528<a class="indexterm" name="id417861"></a>
529The process of joining a domain requires the use of the <code class="literal">net rpc join</code>
530command. This process communicates with the domain controller it will register with
531(usually the PDC) via MS DCE RPC. This means, of course, that the <code class="literal">smbd</code>
532process must be running on the target domain controller. It is therefore necessary to temporarily
533start Samba on a PDC so that it can join its own domain.
534</p><p>
535<a class="indexterm" name="id417886"></a>
536<a class="indexterm" name="id417892"></a>
537<a class="indexterm" name="id417899"></a>
538Enter the following command to make the Samba server join the domain, where <em class="replaceable"><code>PDC</code></em> is
539the name of your PDC and <em class="replaceable"><code>Administrator</code></em> is a domain user who has administrative
540privileges in the domain.
541</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
542<a class="indexterm" name="id417919"></a>
543<a class="indexterm" name="id417925"></a>
544<a class="indexterm" name="id417932"></a>
545<a class="indexterm" name="id417939"></a>
546Before attempting to join a machine to the domain, verify that Samba is running
547on the target domain controller (usually PDC) and that it is capable of being reached via ports
548137/udp, 135/tcp, 139/tcp, and 445/tcp (if Samba or Windows Server 2Kx).
549</p></div><p>
550<a class="indexterm" name="id417951"></a>
551The use of the <code class="literal">net rpc join</code> facility is shown here:
552</p><pre class="screen">
553<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/net rpc join -S PDC -U Administrator</code></strong>
554</pre><p>
555The proper response to the command should be <span class="quote">&#8220;<span class="quote">Joined the domain
556<em class="replaceable"><code>DOMAIN</code></em></span>&#8221;</span> where <em class="replaceable"><code>DOMAIN</code></em>
557is your domain name.
558</p></div><div class="sect3" title="Starting and Testing the winbindd Daemon"><div class="titlepage"><div><div><h4 class="title"><a name="id417997"></a>Starting and Testing the <code class="literal">winbindd</code> Daemon</h4></div></div></div><p>
559<a class="indexterm" name="id418011"></a>
560<a class="indexterm" name="id418018"></a>
561<a class="indexterm" name="id418025"></a>
562Eventually, you will want to modify your Samba startup script to automatically invoke the winbindd daemon when
563the other parts of Samba start, but it is possible to test out just the Winbind portion first. To start up
564Winbind services, enter the following command as root:
565</p><pre class="screen">
566<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/sbin/winbindd</code></strong>
567</pre><p>
568Use the appropriate path to the location of the <code class="literal">winbindd</code> executable file.
569</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
570<a class="indexterm" name="id418061"></a>
571<a class="indexterm" name="id418068"></a>
572The command to start up Winbind services assumes that Samba has been installed in the
573<code class="filename">/usr/local/samba</code> directory tree. You may need to search for the location of Samba files
574if this is not the location of <code class="literal">winbindd</code> on your system.
575</p></div><p>
576<a class="indexterm" name="id418091"></a>
577<a class="indexterm" name="id418098"></a>
578I'm always paranoid and like to make sure the daemon is really running.
579</p><pre class="screen">
580<code class="prompt">root# </code><strong class="userinput"><code>ps -ae | grep winbindd</code></strong>
581</pre><p>
582</p><p>
583<a class="indexterm" name="id418124"></a>
584This command should produce output like the following if the daemon is running.
585</p><pre class="screen">
5863025 ? 00:00:00 winbindd
587</pre><p>
588</p><p>
589<a class="indexterm" name="id418141"></a>
590<a class="indexterm" name="id418148"></a>
591Now, for the real test, try to get some information about the users on your PDC:
592</p><pre class="screen">
593<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -u</code></strong>
594</pre><p>
595This should echo back a list of users on your Windows users on your PDC. For example, I get the following
596response:
597</p><pre class="screen">
598CEO\Administrator
599CEO\burdell
600CEO\Guest
601CEO\jt-ad
602CEO\krbtgt
603CEO\TsInternetUser
604</pre><p>
605Obviously, 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
606<span class="quote">&#8220;<span class="quote">\</span>&#8221;</span>.
607</p><p>
608<a class="indexterm" name="id418202"></a>
609<a class="indexterm" name="id418209"></a>
610You can do the same sort of thing to get group information from the PDC:
611</p><pre class="screen">
612<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -g</code></strong>
613CEO\Domain Admins
614CEO\Domain Users
615CEO\Domain Guests
616CEO\Domain Computers
617CEO\Domain Controllers
618CEO\Cert Publishers
619CEO\Schema Admins
620CEO\Enterprise Admins
621CEO\Group Policy Creator Owners
622</pre><p>
623<a class="indexterm" name="id418235"></a>
624<a class="indexterm" name="id418242"></a>
625<a class="indexterm" name="id418249"></a>
626<a class="indexterm" name="id418255"></a>
627<a class="indexterm" name="id418262"></a>
628<a class="indexterm" name="id418268"></a>
629<a class="indexterm" name="id418275"></a>
630The function <code class="literal">getent</code> can now be used to get unified lists of both local and PDC users and
631groups. Try the following command:
632</p><pre class="screen">
633<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong>
634</pre><p>
635You should get a list that looks like your <code class="filename">/etc/passwd</code>
636list followed by the domain users with their new UIDs, GIDs, home
637directories, and default shells.
638</p><p>
639The same thing can be done for groups with the command:
640</p><pre class="screen">
641<code class="prompt">root# </code><strong class="userinput"><code>getent group</code></strong>
642</pre><p>
643</p></div><div class="sect3" title="Fix the init.d Startup Scripts"><div class="titlepage"><div><div><h4 class="title"><a name="id418334"></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="id418340"></a>Linux</h5></div></div></div><p>
644<a class="indexterm" name="id418348"></a>
645<a class="indexterm" name="id418354"></a>
646<a class="indexterm" name="id418361"></a>
647<a class="indexterm" name="id418368"></a>
648<a class="indexterm" name="id418375"></a>
649<a class="indexterm" name="id418382"></a>
650<a class="indexterm" name="id418388"></a>
651<a class="indexterm" name="id418394"></a>
652<a class="indexterm" name="id418399"></a>
653The <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
654task, you need to modify the startup scripts of your system. They are located at
655<code class="filename">/etc/init.d/smb</code> in Red Hat Linux and in <code class="filename">/etc/init.d/samba</code> in Debian
656Linux. Edit your script to add commands to invoke this daemon in the proper sequence. My startup script starts
657up <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
658<code class="literal">start</code> function in the script looks like this:
659</p><pre class="programlisting">
660start() {
661 KIND="SMB"
662 echo -n $"Starting $KIND services: "
663 daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
664 RETVAL=$?
665 echo
666 KIND="NMB"
667 echo -n $"Starting $KIND services: "
668 daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
669 RETVAL2=$?
670 echo
671 KIND="Winbind"
672 echo -n $"Starting $KIND services: "
673 daemon /usr/local/samba/sbin/winbindd
674 RETVAL3=$?
675 echo
676 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
677 touch /var/lock/subsys/smb || RETVAL=1
678 return $RETVAL
679}
680</pre><p>If you would like to run winbindd in dual daemon mode, replace the line:
681</p><pre class="programlisting">
682 daemon /usr/local/samba/sbin/winbindd
683</pre><p>
684
685in the example above with:
686
687</p><pre class="programlisting">
688 daemon /usr/local/samba/sbin/winbindd -D
689</pre><p>.
690</p><p>
691The <code class="literal">stop</code> function has a corresponding entry to shut down the services and looks like this:
692</p><pre class="programlisting">
693stop() {
694 KIND="SMB"
695 echo -n $"Shutting down $KIND services: "
696 killproc smbd
697 RETVAL=$?
698 echo
699 KIND="NMB"
700 echo -n $"Shutting down $KIND services: "
701 killproc nmbd
702 RETVAL2=$?
703 echo
704 KIND="Winbind"
705 echo -n $"Shutting down $KIND services: "
706 killproc winbindd
707 RETVAL3=$?
708 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
709 rm -f /var/lock/subsys/smb
710 echo ""
711 return $RETVAL
712}
713</pre></div><div class="sect4" title="Solaris"><div class="titlepage"><div><div><h5 class="title"><a name="id418523"></a>Solaris</h5></div></div></div><p>
714Winbind 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>
715for details.
716</p><p>
717<a class="indexterm" name="id418543"></a>
718<a class="indexterm" name="id418549"></a>
719<a class="indexterm" name="id418556"></a>
720<a class="indexterm" name="id418563"></a>
721<a class="indexterm" name="id418570"></a>
722<a class="indexterm" name="id418577"></a>
723On Solaris, you need to modify the <code class="filename">/etc/init.d/samba.server</code> startup script. It
724usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in
725<code class="filename">/usr/local/samba/bin</code>, the file could contains something like this:
726</p><p>
727 </p><pre class="programlisting">
728 ##
729 ## samba.server
730 ##
731
732 if [ ! -d /usr/bin ]
733 then # /usr not mounted
734 exit
735 fi
736
737 killproc() { # kill the named process(es)
738 pid=`/usr/bin/ps -e |
739 /usr/bin/grep -w $1 |
740 /usr/bin/sed -e 's/^ *//' -e 's/ .*//'`
741 [ "$pid" != "" ] &amp;&amp; kill $pid
742 }
743
744 # Start/stop processes required for Samba server
745
746 case "$1" in
747
748 'start')
749 #
750 # Edit these lines to suit your installation (paths, workgroup, host)
751 #
752 echo Starting SMBD
753 /usr/local/samba/bin/smbd -D -s \
754 /usr/local/samba/smb.conf
755
756 echo Starting NMBD
757 /usr/local/samba/bin/nmbd -D -l \
758 /usr/local/samba/var/log -s /usr/local/samba/smb.conf
759
760 echo Starting Winbind Daemon
761 /usr/local/samba/sbin/winbindd
762 ;;
763
764 'stop')
765 killproc nmbd
766 killproc smbd
767 killproc winbindd
768 ;;
769
770 *)
771 echo "Usage: /etc/init.d/samba.server { start | stop }"
772 ;;
773 esac
774</pre><p>
775Again, if you would like to run Samba in dual daemon mode, replace:
776</p><pre class="programlisting">
777/usr/local/samba/sbin/winbindd
778</pre><p>
779in the script above with:
780</p><pre class="programlisting">
781/usr/local/samba/sbin/winbindd -D
782</pre><p>
783</p></div><div class="sect4" title="Restarting"><div class="titlepage"><div><div><h5 class="title"><a name="id418642"></a>Restarting</h5></div></div></div><p>
784<a class="indexterm" name="id418650"></a>
785<a class="indexterm" name="id418657"></a>
786If you restart the <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> daemons at this point, you
787should be able to connect to the Samba server as a domain member just as
788if you were a local user.
789</p></div></div><div class="sect3" title="Configure Winbind and PAM"><div class="titlepage"><div><div><h4 class="title"><a name="id418686"></a>Configure Winbind and PAM</h4></div></div></div><p>
790<a class="indexterm" name="id418694"></a>
791<a class="indexterm" name="id418701"></a>
792<a class="indexterm" name="id418707"></a>
793<a class="indexterm" name="id418714"></a>
794If you have made it this far, you know that <code class="literal">winbindd</code> and Samba are working together. If you
795want to use Winbind to provide authentication for other services, keep reading. The PAM configuration files
796need to be altered in this step. (Did you remember to make backups of your original
797<code class="filename">/etc/pam.d</code> files? If not, do it now.)
798</p><p>
799<a class="indexterm" name="id418738"></a>
800<a class="indexterm" name="id418745"></a>
801<a class="indexterm" name="id418752"></a>
802<a class="indexterm" name="id418759"></a>
803<a class="indexterm" name="id418765"></a>
804<a class="indexterm" name="id418772"></a>
805You will need a PAM module to use winbindd with these other services. This module will be compiled in the
806<code class="filename">../source/nsswitch</code> directory by invoking the command:
807</p><pre class="screen">
808<code class="prompt">root# </code><strong class="userinput"><code>make nsswitch/pam_winbind.so</code></strong>
809</pre><p>
810from the <code class="filename">../source</code> directory. The <code class="filename">pam_winbind.so</code> file should be
811copied to the location of your other PAM security modules. On my Red Hat system, this was the
812<code class="filename">/lib/security</code> directory. On Solaris, the PAM security modules reside in
813<code class="filename">/usr/lib/security</code>.
814</p><pre class="screen">
815<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</code></strong>
816</pre><p>
817</p><div class="sect4" title="Linux/FreeBSD-Specific PAM Configuration"><div class="titlepage"><div><div><h5 class="title"><a name="id418845"></a>Linux/FreeBSD-Specific PAM Configuration</h5></div></div></div><p>
818<a class="indexterm" name="id418853"></a>
819The <code class="filename">/etc/pam.d/samba</code> file does not need to be changed. I just left this file as it was:
820</p><pre class="programlisting">
821auth required /lib/security/pam_stack.so service=system-auth
822account required /lib/security/pam_stack.so service=system-auth
823</pre><p>
824<a class="indexterm" name="id418875"></a>
825<a class="indexterm" name="id418882"></a>
826<a class="indexterm" name="id418889"></a>
827<a class="indexterm" name="id418895"></a>
828<a class="indexterm" name="id418902"></a>
829<a class="indexterm" name="id418909"></a>
830<a class="indexterm" name="id418916"></a>
831<a class="indexterm" name="id418923"></a>
832<a class="indexterm" name="id418929"></a>
833The other services that I modified to allow the use of Winbind as an authentication service were the normal
834login on the console (or a terminal session), telnet logins, and ftp service. In order to enable these
835services, you may first need to change the entries in <code class="filename">/etc/xinetd.d</code> (or
836<code class="filename">/etc/inetd.conf</code>). Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this
837case you need to change the lines in <code class="filename">/etc/xinetd.d/telnet</code> and
838<code class="filename">/etc/xinetd.d/wu-ftp</code> from:
839</p><pre class="programlisting">
840 enable = no
841</pre><p>
842to
843</p><pre class="programlisting">
844 enable = yes
845</pre><p>
846<a class="indexterm" name="id418977"></a>
847<a class="indexterm" name="id418984"></a>
848<a class="indexterm" name="id418991"></a>
849For ftp services to work properly, you will also need to either have individual directories for the domain
850users already present on the server or change the home directory template to a general directory for all
851domain 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>.
852</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
853<a class="indexterm" name="id419023"></a>
854The directory in <a class="link" href="smb.conf.5.html#TEMPLATEHOMEDIR" target="_top">template homedir</a> is not created automatically! Use pam_mkhomedir or
855pre-create the directories of users to make sure users can log in on UNIX with their own home directory.
856</p></div><p>
857<a class="indexterm" name="id419045"></a>
858<a class="indexterm" name="id419052"></a>
859<a class="indexterm" name="id419058"></a>
860The <code class="filename">/etc/pam.d/ftp</code> file can be changed to allow Winbind ftp access in a manner similar to
861the samba file. My <code class="filename">/etc/pam.d/ftp</code> file was changed to look like this:
862</p><pre class="programlisting">
863auth required /lib/security/pam_listfile.so item=user sense=deny \
864 file=/etc/ftpusers onerr=succeed
865auth sufficient /lib/security/pam_winbind.so
866auth required /lib/security/pam_stack.so service=system-auth
867auth required /lib/security/pam_shells.so
868account sufficient /lib/security/pam_winbind.so
869account required /lib/security/pam_stack.so service=system-auth
870session required /lib/security/pam_stack.so service=system-auth
871</pre><p>
872<a class="indexterm" name="id419090"></a>
873The <code class="filename">/etc/pam.d/login</code> file can be changed in nearly the same way. It now looks like this:
874</p><pre class="programlisting">
875auth required /lib/security/pam_securetty.so
876auth sufficient /lib/security/pam_winbind.so
877auth sufficient /lib/security/pam_unix.so use_first_pass
878auth required /lib/security/pam_stack.so service=system-auth
879auth required /lib/security/pam_nologin.so
880account sufficient /lib/security/pam_winbind.so
881account required /lib/security/pam_stack.so service=system-auth
882password required /lib/security/pam_stack.so service=system-auth
883session required /lib/security/pam_stack.so service=system-auth
884session optional /lib/security/pam_console.so
885</pre><p>
886<a class="indexterm" name="id419114"></a>
887<a class="indexterm" name="id419121"></a>
888<a class="indexterm" name="id419128"></a>
889In this case, I added the </p><pre class="programlisting">auth sufficient /lib/security/pam_winbind.so</pre><p> lines
890as before, but also added the </p><pre class="programlisting">required pam_securetty.so</pre><p> above it to disallow
891root logins over the network. I also added a </p><pre class="programlisting">sufficient /lib/security/pam_unix.so
892use_first_pass</pre><p> line after the <code class="literal">winbind.so</code> line to get rid of annoying
893double prompts for passwords.
894</p></div><div class="sect4" title="Solaris-Specific Configuration"><div class="titlepage"><div><div><h5 class="title"><a name="id419163"></a>Solaris-Specific Configuration</h5></div></div></div><p>
895<a class="indexterm" name="id419171"></a>
896<a class="indexterm" name="id419177"></a>
897The <code class="filename">/etc/pam.conf</code> needs to be changed. I changed this file so my Domain
898users can log on both locally as well as with telnet. The following are the changes
899that I made. You can customize the <code class="filename">pam.conf</code> file as per your requirements, but
900be sure of those changes because in the worst case it will leave your system
901nearly impossible to boot.
902</p><pre class="programlisting">
903#
904#ident "@(#)pam.conf 1.14 99/09/16 SMI"
905#
906# Copyright (c) 1996-1999, Sun Microsystems, Inc.
907# All Rights Reserved.
908#
909# PAM configuration
910#
911# Authentication management
912#
913login auth required /usr/lib/security/pam_winbind.so
914login auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
915login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass
916#
917rlogin auth sufficient /usr/lib/security/pam_winbind.so
918rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1
919rlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
920#
921dtlogin auth sufficient /usr/lib/security/pam_winbind.so
922dtlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
923#
924rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1
925other auth sufficient /usr/lib/security/pam_winbind.so
926other auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
927#
928# Account management
929#
930login account sufficient /usr/lib/security/pam_winbind.so
931login account requisite /usr/lib/security/$ISA/pam_roles.so.1
932login account required /usr/lib/security/$ISA/pam_unix.so.1
933#
934dtlogin account sufficient /usr/lib/security/pam_winbind.so
935dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1
936dtlogin account required /usr/lib/security/$ISA/pam_unix.so.1
937#
938other account sufficient /usr/lib/security/pam_winbind.so
939other account requisite /usr/lib/security/$ISA/pam_roles.so.1
940other account required /usr/lib/security/$ISA/pam_unix.so.1
941#
942# Session management
943#
944other session required /usr/lib/security/$ISA/pam_unix.so.1
945#
946# Password management
947#
948#other password sufficient /usr/lib/security/pam_winbind.so
949other password required /usr/lib/security/$ISA/pam_unix.so.1
950dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1
951#
952# Support for Kerberos V5 authentication (uncomment to use Kerberos)
953#
954#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
955#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
956#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
957#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
958#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1
959#other account optional /usr/lib/security/$ISA/pam_krb5.so.1
960#other session optional /usr/lib/security/$ISA/pam_krb5.so.1
961#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
962</pre><p>
963<a class="indexterm" name="id419226"></a>
964I also added a <em class="parameter"><code>try_first_pass</code></em> line after the <code class="filename">winbind.so</code>
965line to get rid of annoying double prompts for passwords.
966</p><p>
967Now restart your Samba and try connecting through your application that you
968configured in the pam.conf.
969</p></div></div></div></div><div class="sect1" title="Conclusion"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id419254"></a>Conclusion</h2></div></div></div><p>
970<a class="indexterm" name="id419262"></a>
971<a class="indexterm" name="id419268"></a>
972<a class="indexterm" name="id419275"></a>
973<a class="indexterm" name="id419281"></a>
974<a class="indexterm" name="id419288"></a>
975The Winbind system, through the use of the NSS, PAMs, and appropriate Microsoft RPC calls, have allowed us to
976provide seamless integration of Microsoft Windows NT domain users on a UNIX system. The result is a great
977reduction in the administrative cost of running a mixed UNIX and NT network.
978</p></div><div class="sect1" title="Common Errors"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id419300"></a>Common Errors</h2></div></div></div><p>
979 Winbind has a number of limitations in its current released version that we hope to overcome in future releases:
980 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
981 Winbind is currently only available for the Linux, Solaris, AIX, and IRIX operating systems, although
982 ports to other operating systems are certainly possible. For such ports to be feasible, we require the C
983 library of the target operating system to support the NSS and PAM systems. This is becoming more common as NSS
984 and PAM gain support among UNIX vendors.
985 </p></li><li class="listitem"><p>
986 The mappings of Windows NT RIDs to UNIX IDs is not made algorithmically and depends on the order in
987 which unmapped users or groups are seen by Winbind. It may be difficult to recover the mappings of RID to UNIX
988 ID if the file containing this information is corrupted or destroyed.
989 </p></li><li class="listitem"><p>
990 Currently the Winbind PAM module does not take into account possible workstation and logon time
991 restrictions that may be set for Windows NT users; this is instead up to the PDC to enforce.
992 </p></li></ul></div><div class="sect2" title="NSCD Problem Warning"><div class="titlepage"><div><div><h3 class="title"><a name="id419333"></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>
993 Do not under any circumstances run <code class="literal">nscd</code> on any system
994 on which <code class="literal">winbindd</code> is running.
995 </p></div><p>
996 If <code class="literal">nscd</code> is running on the UNIX/Linux system, then
997 even though NSSWITCH is correctly configured, it will not be possible to resolve
998 domain users and groups for file and directory controls.
999 </p></div><div class="sect2" title="Winbind Is Not Resolving Users and Groups"><div class="titlepage"><div><div><h3 class="title"><a name="id419367"></a>Winbind Is Not Resolving Users and Groups</h3></div></div></div><p><span class="quote">&#8220;<span class="quote">
1000 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>,
1001 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.
1002 When I do the following, it all works fine.
1003 </span>&#8221;</span></p><pre class="screen">
1004<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -u</code></strong>
1005MIDEARTH\maryo
1006MIDEARTH\jackb
1007MIDEARTH\ameds
1008...
1009MIDEARTH\root
1010
1011<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -g</code></strong>
1012MIDEARTH\Domain Users
1013MIDEARTH\Domain Admins
1014MIDEARTH\Domain Guests
1015...
1016MIDEARTH\Accounts
1017
1018<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong>
1019root:x:0:0:root:/root:/bin/bash
1020bin:x:1:1:bin:/bin:/bin/bash
1021...
1022maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false
1023</pre><p><span class="quote">&#8220;<span class="quote">
1024But the following command just fails:
1025</span>&#8221;</span>
1026</p><pre class="screen">
1027<code class="prompt">root# </code><strong class="userinput"><code>chown maryo a_file</code></strong>
1028chown: `maryo': invalid user
1029</pre><p>
1030<span class="quote">&#8220;<span class="quote">
1031This is driving me nuts! What can be wrong?
1032</span>&#8221;</span></p><p>
1033Same problem as the one above.
1034Your system is likely running <code class="literal">nscd</code>, the name service
1035caching daemon. Shut it down, do not restart it! You will find your problem resolved.
1036Alternately, fix the operation of nscd to resolve the problem.
1037</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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