source: trunk-3.0/docs/htmldocs/Samba3-HOWTO/winbind.html@ 103

Last change on this file since 103 was 44, checked in by Paul Smedley, 18 years ago

Update source to 3.0.25b
File size: 70.3 KB
Line 
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 V1.71.0"><link rel="start" href="index.html" title="The Official Samba-3 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" lang="en"><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 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 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 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 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 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 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#id411256">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="winbind.html#id411579">Introduction</a></span></dt><dt><span class="sect1"><a href="winbind.html#id411657">What Winbind Provides</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id411796">Target Uses</a></span></dt><dt><span class="sect2"><a href="winbind.html#id411839">Handling of Foreign SIDs</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id411950">How Winbind Works</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id411998">Microsoft Remote Procedure Calls</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412076">Microsoft Active Directory Services</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412120">Name Service Switch</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412336">Pluggable Authentication Modules</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412481">User and Group ID Allocation</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412549">Result Caching</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id412600">Installation and Configuration</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id412605">Introduction</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412712">Requirements</a></span></dt><dt><span class="sect2"><a href="winbind.html#id412857">Testing Things Out</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id415146">Conclusion</a></span></dt><dt><span class="sect1"><a href="winbind.html#id415192">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id415226">NSCD Problem Warning</a></span></dt><dt><span class="sect2"><a href="winbind.html#id415261">Winbind Is Not Resolving Users and Groups</a></span></dt></dl></dd></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id411256"></a>Features and Benefits</h2></div></div></div><p>
2<a class="indexterm" name="id411264"></a>
3<a class="indexterm" name="id411270"></a>
4 Integration of UNIX and Microsoft Windows NT through a unified logon has
5 been considered a &#8220;<span class="quote">holy grail</span>&#8221; in heterogeneous computing environments for
6 a long time.
7 </p><p>
8<a class="indexterm" name="id411285"></a>
9<a class="indexterm" name="id411292"></a>
10<a class="indexterm" name="id411299"></a>
11<a class="indexterm" name="id411306"></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="id411318"></a>
18<a class="indexterm" name="id411327"></a>
19<a class="indexterm" name="id411334"></a>
20<a class="indexterm" name="id411341"></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 type="disc"><li><p>
30<a class="indexterm" name="id411364"></a>
31<a class="indexterm" name="id411371"></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><p>
36<a class="indexterm" name="id411384"></a>
37<a class="indexterm" name="id411391"></a>
38 Identity resolution (via NSS). This is the default when winbind is not used.
39 </p></li><li><p>
40<a class="indexterm" name="id411402"></a>
41<a class="indexterm" name="id411409"></a>
42<a class="indexterm" name="id411416"></a>
43<a class="indexterm" name="id411422"></a>
44<a class="indexterm" name="id411429"></a>
45<a class="indexterm" name="id411436"></a>
46<a class="indexterm" name="id411442"></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" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
55 <a class="indexterm" name="id411468"></a>
56 <a class="indexterm" name="id411475"></a>
57<a class="indexterm" name="id411484"></a>
58<a class="indexterm" name="id411491"></a>
59<a class="indexterm" name="id411498"></a>
60<a class="indexterm" name="id411504"></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" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id411579"></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="id411593"></a>
71<a class="indexterm" name="id411600"></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 type="disc"><li><p>Obtaining Windows NT user and group information.
81 </p></li><li><p>Authenticating Windows NT users.
82 </p></li><li><p>Password changing for Windows NT users.
83 </p></li></ul></div><p>
84<a class="indexterm" name="id411638"></a>
85<a class="indexterm" name="id411645"></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" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id411657"></a>What Winbind Provides</h2></div></div></div><p>
93<a class="indexterm" name="id411665"></a>
94<a class="indexterm" name="id411672"></a>
95<a class="indexterm" name="id411679"></a>
96<a class="indexterm" name="id411686"></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 &#8220;<span class="quote">native</span>&#8221; 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="id411702"></a>
104<a class="indexterm" name="id411709"></a>
105<a class="indexterm" name="id411716"></a>
106<a class="indexterm" name="id411722"></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="id411736"></a>
116<a class="indexterm" name="id411743"></a>
117 Users on the UNIX machine can then use NT user and group
118 names as they would &#8220;<span class="quote">native</span>&#8221; 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="id411758"></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="id411778"></a>
128<a class="indexterm" name="id411785"></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" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id411796"></a>Target Uses</h3></div></div></div><p>
134<a class="indexterm" name="id411804"></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="id411820"></a>
143<a class="indexterm" name="id411827"></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" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id411839"></a>Handling of Foreign SIDs</h3></div></div></div><p>
149<a class="indexterm" name="id411847"></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="id411863"></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="id411874"></a>
160 Response: &#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;
163 </p><p>
164<a class="indexterm" name="id411889"></a>
165<a class="indexterm" name="id411895"></a>
166<a class="indexterm" name="id411902"></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="id411915"></a>
173<a class="indexterm" name="id411922"></a>
174<a class="indexterm" name="id411928"></a>
175<a class="indexterm" name="id411935"></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" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id411950"></a>How Winbind Works</h2></div></div></div><p>
185<a class="indexterm" name="id411958"></a>
186<a class="indexterm" name="id411965"></a>
187<a class="indexterm" name="id411972"></a>
188<a class="indexterm" name="id411978"></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" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id411998"></a>Microsoft Remote Procedure Calls</h3></div></div></div><p>
195<a class="indexterm" name="id412006"></a>
196<a class="indexterm" name="id412015"></a>
197<a class="indexterm" name="id412022"></a>
198<a class="indexterm" name="id412028"></a>
199<a class="indexterm" name="id412035"></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="id412050"></a>
207<a class="indexterm" name="id412056"></a>
208<a class="indexterm" name="id412063"></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" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412076"></a>Microsoft Active Directory Services</h3></div></div></div><p>
214<a class="indexterm" name="id412083"></a>
215<a class="indexterm" name="id412090"></a>
216<a class="indexterm" name="id412097"></a>
217<a class="indexterm" name="id412104"></a>
218 Since late 2001, Samba has gained the ability to interact with Microsoft Windows 2000 using its &#8220;<span class="quote">native
219 mode</span>&#8221; 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" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412120"></a>Name Service Switch</h3></div></div></div><p>
223<a class="indexterm" name="id412127"></a>
224<a class="indexterm" name="id412134"></a>
225<a class="indexterm" name="id412141"></a>
226<a class="indexterm" name="id412147"></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="id412162"></a>
236<a class="indexterm" name="id412168"></a>
237<a class="indexterm" name="id412175"></a>
238<a class="indexterm" name="id412182"></a>
239<a class="indexterm" name="id412188"></a>
240 The NSS application programming interface allows Winbind
241 to present itself as a source of system information when
242 resolving UNIX usernames and groups. Winbind uses this interface
243 and information obtained from a Windows NT server using MSRPC
244 calls to provide a new source of account enumeration. Using standard
245 UNIX library calls, you can enumerate the users and groups on
246 a UNIX machine running Winbind and see all users and groups in
247 an NT domain plus any trusted domain as though they were local
248 users and groups.</p><p>
249<a class="indexterm" name="id412208"></a>
250<a class="indexterm" name="id412214"></a>
251<a class="indexterm" name="id412221"></a>
252 The primary control file for NSS is <code class="filename">/etc/nsswitch.conf</code>.
253 When a UNIX application makes a request to do a lookup,
254 the C library looks in <code class="filename">/etc/nsswitch.conf</code>
255 for a line that matches the service type being requested; for
256 example, the &#8220;<span class="quote">passwd</span>&#8221; service type is used when user or group names
257 are looked up. This config line specifies which implementations
258 of that service should be tried and in what order. If the passwd
259 config line is:
260</p><pre class="screen">
261passwd: files example
262</pre><p>
263<a class="indexterm" name="id412252"></a>
264<a class="indexterm" name="id412259"></a>
265<a class="indexterm" name="id412266"></a>
266 then the C library will first load a module called
267 <code class="filename">/lib/libnss_files.so</code> followed by
268 the module <code class="filename">/lib/libnss_example.so</code>. The
269 C library will dynamically load each of these modules in turn
270 and call resolver functions within the modules to try to resolve
271 the request. Once the request is resolved, the C library returns the
272 result to the application.</p><p>
273<a class="indexterm" name="id412291"></a>
274<a class="indexterm" name="id412297"></a>
275<a class="indexterm" name="id412304"></a>
276 This NSS interface provides an easy way for Winbind
277 to hook into the operating system. All that needs to be done
278 is to put <code class="filename">libnss_winbind.so</code> in <code class="filename">/lib/</code>
279 then add &#8220;<span class="quote">winbind</span>&#8221; into <code class="filename">/etc/nsswitch.conf</code> at
280 the appropriate place. The C library will then call Winbind to
281 resolve user and group names.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412336"></a>Pluggable Authentication Modules</h3></div></div></div><p>
282<a class="indexterm" name="id412344"></a>
283<a class="indexterm" name="id412351"></a>
284<a class="indexterm" name="id412358"></a>
285<a class="indexterm" name="id412364"></a>
286 PAMs provide a system for abstracting authentication and authorization
287 technologies. With a PAM module, it is possible to specify different
288 authentication methods for different system applications without
289 having to recompile these applications. PAM is also useful
290 for implementing a particular policy for authorization. For example,
291 a system administrator may only allow console logins from users
292 stored in the local password file but only allow users resolved from
293 an NIS database to log in over the network.</p><p>
294<a class="indexterm" name="id412379"></a>
295<a class="indexterm" name="id412386"></a>
296<a class="indexterm" name="id412392"></a>
297<a class="indexterm" name="id412399"></a>
298<a class="indexterm" name="id412406"></a>
299 Winbind uses the authentication management and password
300 management PAM interface to integrate Windows NT users into a
301 UNIX system. This allows Windows NT users to log in to a UNIX
302 machine and be authenticated against a suitable PDC.
303 These users can also change their passwords and have
304 this change take effect directly on the PDC.
305 </p><p>
306<a class="indexterm" name="id412422"></a>
307<a class="indexterm" name="id412428"></a>
308<a class="indexterm" name="id412435"></a>
309<a class="indexterm" name="id412442"></a>
310 PAM is configured by providing control files in the directory
311 <code class="filename">/etc/pam.d/</code> for each of the services that
312 require authentication. When an authentication request is made
313 by an application, the PAM code in the C library looks up this
314 control file to determine what modules to load to do the
315 authentication check and in what order. This interface makes adding
316 a new authentication service for Winbind very easy: simply copy
317 the <code class="filename">pam_winbind.so</code> module
318 to <code class="filename">/lib/security/</code>, and the PAM
319 control files for relevant services are updated to allow
320 authentication via Winbind. See the PAM documentation
321 in <a href="pam.html" title="Chapter 28. PAM-Based Distributed Authentication">PAM-Based Distributed Authentication</a>, for more information.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412481"></a>User and Group ID Allocation</h3></div></div></div><p>
322<a class="indexterm" name="id412488"></a>
323<a class="indexterm" name="id412495"></a>
324<a class="indexterm" name="id412502"></a>
325 When a user or group is created under Windows NT/200x,
326 it is allocated a numerical relative identifier (RID). This is
327 slightly different from UNIX, which has a range of numbers that are
328 used to identify users and the same range used to identify
329 groups. It is Winbind's job to convert RIDs to UNIX ID numbers and
330 vice versa. When Winbind is configured, it is given part of the UNIX
331 user ID space and a part of the UNIX group ID space in which to
332 store Windows NT users and groups. If a Windows NT user is
333 resolved for the first time, it is allocated the next UNIX ID from
334 the range. The same process applies for Windows NT groups. Over
335 time, Winbind will have mapped all Windows NT users and groups
336 to UNIX user IDs and group IDs.</p><p>
337<a class="indexterm" name="id412518"></a>
338<a class="indexterm" name="id412525"></a>
339<a class="indexterm" name="id412532"></a>
340<a class="indexterm" name="id412539"></a>
341 The results of this mapping are stored persistently in
342 an ID mapping database held in a tdb database. This ensures that
343 RIDs are mapped to UNIX IDs in a consistent way.</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412549"></a>Result Caching</h3></div></div></div><p>
344<a class="indexterm" name="id412557"></a>
345<a class="indexterm" name="id412563"></a>
346<a class="indexterm" name="id412570"></a>
347<a class="indexterm" name="id412577"></a>
348<a class="indexterm" name="id412583"></a>
349 An active directory system can generate a lot of user and group
350 name lookups. To reduce the network cost of these lookups, Winbind
351 uses a caching scheme based on the SAM sequence number supplied
352 by NT domain controllers. User or group information returned
353 by a PDC is cached by Winbind along with a sequence number also
354 returned by the PDC. This sequence number is incremented by
355 Windows NT whenever any user or group information is modified. If
356 a cached entry has expired, the sequence number is requested from
357 the PDC and compared against the sequence number of the cached entry.
358 If the sequence numbers do not match, then the cached information
359 is discarded and up-to-date information is requested directly
360 from the PDC.</p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id412600"></a>Installation and Configuration</h2></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412605"></a>Introduction</h3></div></div></div><p>
361<a class="indexterm" name="id412613"></a>
362<a class="indexterm" name="id412620"></a>
363<a class="indexterm" name="id412626"></a>
364This section describes the procedures used to get Winbind up and
365running. Winbind is capable of providing access
366and authentication control for Windows Domain users through an NT
367or Windows 200x PDC for regular services, such as telnet and ftp, as
368well for Samba services.
369</p><div class="itemizedlist"><ul type="disc"><li><p>
370 <span class="emphasis"><em>Why should I do this?</em></span>
371 </p><p>
372<a class="indexterm" name="id412650"></a>
373<a class="indexterm" name="id412657"></a>
374<a class="indexterm" name="id412664"></a>
375<a class="indexterm" name="id412670"></a>
376 This allows the Samba administrator to rely on the
377 authentication mechanisms on the Windows NT/200x PDC for the authentication
378 of domain members. Windows NT/200x users no longer need to have separate
379 accounts on the Samba server.
380 </p></li><li><p>
381 <span class="emphasis"><em>Who should be reading this document?</em></span>
382 </p><p>
383<a class="indexterm" name="id412692"></a>
384<a class="indexterm" name="id412699"></a>
385 This document is designed for system administrators. If you are
386 implementing Samba on a file server and wish to (fairly easily)
387 integrate existing Windows NT/200x users from your PDC onto the
388 Samba server, this document is for you.
389 </p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412712"></a>Requirements</h3></div></div></div><p>
390<a class="indexterm" name="id412720"></a>
391<a class="indexterm" name="id412726"></a>
392<a class="indexterm" name="id412733"></a>
393If you have a Samba configuration file that you are currently using, <span class="emphasis"><em>BACK IT UP!</em></span>
394If your system already uses PAM, <span class="emphasis"><em>back up the <code class="filename">/etc/pam.d</code> directory
395contents!</em></span> If you haven't already made a boot disk, <span class="emphasis"><em>MAKE ONE NOW!</em></span>
396</p><p>
397<a class="indexterm" name="id412761"></a>
398<a class="indexterm" name="id412768"></a>
399<a class="indexterm" name="id412775"></a>
400Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's
401why you want to be able to boot back into your machine in single-user mode and restore your
402<code class="filename">/etc/pam.d</code> to the original state it was in if you get frustrated with the
403way things are going.
404</p><p>
405<a class="indexterm" name="id412793"></a>
406<a class="indexterm" name="id412800"></a>
407The latest version of Samba-3 includes a functioning winbindd daemon. Please refer to the <a href="http://samba.org/" target="_top">main Samba Web page</a>, or better yet, your closest Samba mirror site for
408instructions on downloading the source code.
409</p><p>
410<a class="indexterm" name="id412818"></a>
411<a class="indexterm" name="id412824"></a>
412<a class="indexterm" name="id412831"></a>
413<a class="indexterm" name="id412838"></a>
414To allow domain users the ability to access Samba shares and files, as well as potentially other services
415provided by your Samba machine, PAM must be set up properly on your
416machine. In order to compile the Winbind modules, you should have at least the PAM development libraries installed
417on your system. Please refer to the PAM Web site <a href="http://www.kernel.org/pub/linux/libs/pam/" target="_top">http://www.kernel.org/pub/linux/libs/pam/</a>.
418</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id412857"></a>Testing Things Out</h3></div></div></div><p>
419<a class="indexterm" name="id412865"></a>
420<a class="indexterm" name="id412872"></a>
421<a class="indexterm" name="id412878"></a>
422<a class="indexterm" name="id412885"></a>
423<a class="indexterm" name="id412892"></a>
424Before starting, it is probably best to kill off all the Samba-related daemons running on your server.
425Kill 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,
426make sure that you have the standard PAM package that supplies the <code class="filename">/etc/pam.d</code>
427directory structure, including the PAM modules that are used by PAM-aware services, several PAM libraries,
428and the <code class="filename">/usr/doc</code> and <code class="filename">/usr/man</code> entries for PAM. Winbind is built
429better in Samba if the pam-devel package is also installed. This package includes the header files
430needed to compile PAM-aware applications.
431</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id412939"></a>Configure <code class="filename">nsswitch.conf</code> and the Winbind Libraries on Linux and Solaris</h4></div></div></div><p>
432<a class="indexterm" name="id412953"></a>
433<a class="indexterm" name="id412960"></a>
434<a class="indexterm" name="id412967"></a>
435<a class="indexterm" name="id412973"></a>
436PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install
437the <code class="filename">pam-devel</code> libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3
438may auto-install the Winbind files into their correct locations on your system, so before you get too far down
439the track, be sure to check if the following configuration is really
440necessary. You may only need to configure
441<code class="filename">/etc/nsswitch.conf</code>.
442</p><p>
443The libraries needed to run the <span class="application">winbindd</span> daemon through nsswitch need to be copied to their proper locations:
444</p><p>
445<a class="indexterm" name="id413009"></a>
446</p><pre class="screen">
447<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/libnss_winbind.so /lib</code></strong>
448</pre><p>
449</p><p>
450I also found it necessary to make the following symbolic link:
451</p><p>
452<code class="prompt">root# </code> <strong class="userinput"><code>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</code></strong>
453</p><p>And, in the case of Sun Solaris:
454<a class="indexterm" name="id413054"></a>
455</p><pre class="screen">
456<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1</code></strong>
457<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1</code></strong>
458<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</code></strong>
459</pre><p>
460</p><p>
461<a class="indexterm" name="id413102"></a>
462As root, edit <code class="filename">/etc/nsswitch.conf</code> to
463allow user and group entries to be visible from the <span class="application">winbindd</span>
464daemon. My <code class="filename">/etc/nsswitch.conf</code> file looked like
465this after editing:
466</p><pre class="programlisting">
467passwd: files winbind
468shadow: files
469group: files winbind
470</pre><p>
471<a class="indexterm" name="id413136"></a>
472<a class="indexterm" name="id413143"></a>
473<a class="indexterm" name="id413149"></a>
474<a class="indexterm" name="id413156"></a>
475<a class="indexterm" name="id413163"></a>
476The libraries needed by the <code class="literal">winbindd</code> daemon will be automatically
477entered into the <code class="literal">ldconfig</code> cache the next time
478your system reboots, but it is faster (and you do not need to reboot) if you do it manually:
479</p><pre class="screen">
480<code class="prompt">root# </code><strong class="userinput"><code>/sbin/ldconfig -v | grep winbind</code></strong>
481</pre><p>
482This makes <code class="filename">libnss_winbind</code> available to winbindd and reports the current
483search path that is used by the dynamic link loader. The use of the <code class="literal">grep</code>
484filters the output of the <code class="literal">ldconfig</code> command so that we may see proof that
485this library is indeed recognized by the dynamic link loader.
486</p><p>
487<a class="indexterm" name="id413222"></a>
488<a class="indexterm" name="id413229"></a>
489<a class="indexterm" name="id413236"></a>
490<a class="indexterm" name="id413243"></a>
491<a class="indexterm" name="id413250"></a>
492The Sun Solaris dynamic link loader management tool is called <code class="literal">crle</code>. The
493use of this tool is necessary to instruct the dynamic link loader to search directories that
494contain library files that were not supplied as part of the original operating system platform.
495The following example shows how to use this tool to add the directory <code class="filename">/usr/local/lib</code>
496to the dynamic link loader's search path:
497</p><pre class="screen">
498<code class="prompt">root# </code> crle -u -l /usr/lib:/usr/local/lib
499</pre><p>
500When executed without arguments, <code class="literal">crle</code> reports the current dynamic
501link loader configuration. This is demonstrated here:
502</p><pre class="screen">
503<code class="prompt">root# </code> crle
504
505Configuration file [version 4]: /var/ld/ld.config
506 Default Library Path (ELF): /lib:/usr/lib:/usr/local/lib
507 Trusted Directories (ELF): /lib/secure:/usr/lib/secure (system default)
508
509Command line:
510 crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/local/lib
511</pre><p>
512From this it is apparent that the <code class="filename">/usr/local/lib</code> directory is included
513in the search dynamic link libraries in order to satisfy object module dependencies.
514</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id413313"></a>NSS Winbind on AIX</h4></div></div></div><p>(This section is only for those running AIX.)</p><p>
515<a class="indexterm" name="id413325"></a>
516<a class="indexterm" name="id413331"></a>
517<a class="indexterm" name="id413338"></a>
518<a class="indexterm" name="id413345"></a>
519<a class="indexterm" name="id413352"></a>
520<a class="indexterm" name="id413359"></a>
521The Winbind AIX identification module gets built as <code class="filename">libnss_winbind.so</code> in the
522nsswitch directory of the Samba source. This file can be copied to <code class="filename">/usr/lib/security</code>,
523and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following:
524</p><pre class="programlisting">
525WINBIND:
526 program = /usr/lib/security/WINBIND
527 options = authonly
528</pre><p>
529can then be added to <code class="filename">/usr/lib/security/methods.cfg</code>. This module only supports
530identification, but there have been reports of success using the standard Winbind PAM module for
531authentication. Use caution configuring loadable authentication modules, since misconfiguration can make
532it impossible to log on to the system. Information regarding the AIX authentication module API can
533be found in the &#8220;<span class="quote">Kernel Extensions and Device Support Programming Concepts for AIX</span>&#8221; document that
534describes the <a href="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixprggd/kernextc/sec_load_mod.htm" target="_top">
535Loadable Authentication Module Programming Interface</a> for AIX. Further information on administering the modules
536can be found in the <a href="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixbman/baseadmn/iandaadmin.htm" target="_top">System
537Management Guide: Operating System and Devices.</a>
538</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id413415"></a>Configure smb.conf</h4></div></div></div><p>
539<a class="indexterm" name="id413423"></a>
540<a class="indexterm" name="id413430"></a>
541<a class="indexterm" name="id413436"></a>
542Several parameters are needed in the <code class="filename">smb.conf</code> file to control the behavior of <span class="application">winbindd</span>. These
543are described in more detail in the <a 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 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.
544</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 class="simplelist" border="0" summary="Simple list"><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="id413507"></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="id413523"></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="id413539"></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="id413556"></a><em class="parameter"><code>winbind enum users = yes</code></em></td></tr><tr><td><a class="indexterm" name="id413568"></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="id413585"></a><em class="parameter"><code>template homedir = /home/winnt/%D/%U</code></em></td></tr><tr><td><a class="indexterm" name="id413598"></a><em class="parameter"><code>template shell = /bin/bash</code></em></td></tr></table></div></div><br class="example-break"></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id413612"></a>Join the Samba Server to the PDC Domain</h4></div></div></div><p>
545<a class="indexterm" name="id413620"></a>
546<a class="indexterm" name="id413627"></a>
547<a class="indexterm" name="id413634"></a>
548All machines that will participate in domain security should be members of
549the domain. This applies also to the PDC and all BDCs.
550</p><p>
551<a class="indexterm" name="id413645"></a>
552<a class="indexterm" name="id413651"></a>
553<a class="indexterm" name="id413658"></a>
554<a class="indexterm" name="id413669"></a>
555<a class="indexterm" name="id413676"></a>
556<a class="indexterm" name="id413683"></a>
557<a class="indexterm" name="id413689"></a>
558<a class="indexterm" name="id413696"></a>
559<a class="indexterm" name="id413703"></a>
560The process of joining a domain requires the use of the <code class="literal">net rpc join</code>
561command. This process communicates with the domain controller it will register with
562(usually the PDC) via MS DCE RPC. This means, of course, that the <code class="literal">smbd</code>
563process must be running on the target domain controller. It is therefore necessary to temporarily
564start Samba on a PDC so that it can join its own domain.
565</p><p>
566<a class="indexterm" name="id413728"></a>
567<a class="indexterm" name="id413734"></a>
568<a class="indexterm" name="id413741"></a>
569Enter the following command to make the Samba server join the
570domain, where <em class="replaceable"><code>PDC</code></em> is the name of
571your PDC and <em class="replaceable"><code>Administrator</code></em> is
572a domain user who has administrative privileges in the domain.
573</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
574<a class="indexterm" name="id413761"></a>
575<a class="indexterm" name="id413768"></a>
576<a class="indexterm" name="id413774"></a>
577<a class="indexterm" name="id413781"></a>
578Before attempting to join a machine to the domain, verify that Samba is running
579on the target domain controller (usually PDC) and that it is capable of being reached via ports
580137/udp, 135/tcp, 139/tcp, and 445/tcp (if Samba or Windows Server 2Kx).
581</p></div><p>
582<a class="indexterm" name="id413793"></a>
583The use of the <code class="literal">net rpc join</code> facility is shown here:
584</p><pre class="screen">
585<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/net rpc join -S PDC -U Administrator</code></strong>
586</pre><p>
587The proper response to the command should be &#8220;<span class="quote">Joined the domain
588<em class="replaceable"><code>DOMAIN</code></em></span>&#8221; where <em class="replaceable"><code>DOMAIN</code></em>
589is your domain name.
590</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id413839"></a>Starting and Testing the <code class="literal">winbindd</code> Daemon</h4></div></div></div><p>
591<a class="indexterm" name="id413853"></a>
592<a class="indexterm" name="id413860"></a>
593<a class="indexterm" name="id413867"></a>
594Eventually, you will want to modify your Samba startup script to
595automatically invoke the winbindd daemon when the other parts of
596Samba start, but it is possible to test out just the Winbind
597portion first. To start up Winbind services, enter the following
598command as root:
599</p><pre class="screen">
600<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/sbin/winbindd</code></strong>
601</pre><p>
602Use the appropriate path to the location of the <code class="literal">winbindd</code> executable file.
603</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
604<a class="indexterm" name="id413903"></a>
605<a class="indexterm" name="id413910"></a>
606The command to start up Winbind services assumes that Samba has been installed in the <code class="filename">/usr/local/samba</code>
607directory tree. You may need to search for the location of Samba files if this is not the
608location of <code class="literal">winbindd</code> on your system.
609</p></div><p>
610<a class="indexterm" name="id413933"></a>
611<a class="indexterm" name="id413940"></a>
612Winbindd can now also run in &#8220;<span class="quote">dual daemon mode</span>&#8221;. This will make it
613run as two processes. The first will answer all requests from the cache,
614thus making responses to clients faster. The other will
615update the cache for the query to which the first has just responded.
616The advantage of this is that responses stay accurate and are faster.
617You can enable dual daemon mode by adding <code class="option">-B</code> to the command line:
618</p><pre class="screen">
619<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/sbin/winbindd -B</code></strong>
620</pre><p>
621</p><p>
622<a class="indexterm" name="id413976"></a>
623<a class="indexterm" name="id413983"></a>
624I'm always paranoid and like to make sure the daemon is really running.
625</p><pre class="screen">
626<code class="prompt">root# </code><strong class="userinput"><code>ps -ae | grep winbindd</code></strong>
627</pre><p>
628</p><p>
629<a class="indexterm" name="id414010"></a>
630This command should produce output like the following if the daemon is running.
631</p><pre class="screen">
6323025 ? 00:00:00 winbindd
633</pre><p>
634</p><p>
635<a class="indexterm" name="id414026"></a>
636<a class="indexterm" name="id414033"></a>
637Now, for the real test, try to get some information about the users on your PDC:
638</p><pre class="screen">
639<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -u</code></strong>
640</pre><p>
641This should echo back a list of users on your Windows users on
642your PDC. For example, I get the following response:
643</p><pre class="screen">
644CEO\Administrator
645CEO\burdell
646CEO\Guest
647CEO\jt-ad
648CEO\krbtgt
649CEO\TsInternetUser
650</pre><p>
651Obviously, I have named my domain &#8220;<span class="quote">CEO</span>&#8221; and my <a class="indexterm" name="id414068"></a>winbind separator is &#8220;<span class="quote">\</span>&#8221;.
652</p><p>
653<a class="indexterm" name="id414081"></a>
654<a class="indexterm" name="id414088"></a>
655You can do the same sort of thing to get group information from the PDC:
656</p><pre class="screen">
657<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -g</code></strong>
658CEO\Domain Admins
659CEO\Domain Users
660CEO\Domain Guests
661CEO\Domain Computers
662CEO\Domain Controllers
663CEO\Cert Publishers
664CEO\Schema Admins
665CEO\Enterprise Admins
666CEO\Group Policy Creator Owners
667</pre><p>
668<a class="indexterm" name="id414115"></a>
669<a class="indexterm" name="id414122"></a>
670<a class="indexterm" name="id414128"></a>
671<a class="indexterm" name="id414135"></a>
672<a class="indexterm" name="id414142"></a>
673<a class="indexterm" name="id414148"></a>
674<a class="indexterm" name="id414155"></a>
675The function <code class="literal">getent</code> can now be used to get unified
676lists of both local and PDC users and groups. Try the following command:
677</p><pre class="screen">
678<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong>
679</pre><p>
680You should get a list that looks like your <code class="filename">/etc/passwd</code>
681list followed by the domain users with their new UIDs, GIDs, home
682directories, and default shells.
683</p><p>
684The same thing can be done for groups with the command:
685</p><pre class="screen">
686<code class="prompt">root# </code><strong class="userinput"><code>getent group</code></strong>
687</pre><p>
688</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id414214"></a>Fix the init.d Startup Scripts</h4></div></div></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id414220"></a>Linux</h5></div></div></div><p>
689<a class="indexterm" name="id414227"></a>
690<a class="indexterm" name="id414234"></a>
691<a class="indexterm" name="id414241"></a>
692<a class="indexterm" name="id414248"></a>
693<a class="indexterm" name="id414255"></a>
694<a class="indexterm" name="id414261"></a>
695<a class="indexterm" name="id414268"></a>
696<a class="indexterm" name="id414274"></a>
697<a class="indexterm" name="id414279"></a>
698The <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.
699To accomplish this task, you need to modify the startup scripts of your system.
700They are located at <code class="filename">/etc/init.d/smb</code> in Red Hat Linux and in
701<code class="filename">/etc/init.d/samba</code> in Debian Linux. Edit your
702script to add commands to invoke this daemon in the proper sequence. My
703startup script starts up <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> from the
704<code class="filename">/usr/local/samba/bin</code> directory directly. The <code class="literal">start</code>
705function in the script looks like this:
706</p><pre class="programlisting">
707start() {
708 KIND="SMB"
709 echo -n $"Starting $KIND services: "
710 daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
711 RETVAL=$?
712 echo
713 KIND="NMB"
714 echo -n $"Starting $KIND services: "
715 daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
716 RETVAL2=$?
717 echo
718 KIND="Winbind"
719 echo -n $"Starting $KIND services: "
720 daemon /usr/local/samba/sbin/winbindd
721 RETVAL3=$?
722 echo
723 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
724 touch /var/lock/subsys/smb || RETVAL=1
725 return $RETVAL
726}
727</pre><p>If you would like to run winbindd in dual daemon mode, replace
728the line:
729</p><pre class="programlisting">
730 daemon /usr/local/samba/sbin/winbindd
731</pre><p>
732
733in the example above with:
734
735</p><pre class="programlisting">
736 daemon /usr/local/samba/sbin/winbindd -B
737</pre><p>.
738</p><p>
739The <code class="literal">stop</code> function has a corresponding entry to shut down the
740services and looks like this:
741</p><pre class="programlisting">
742stop() {
743 KIND="SMB"
744 echo -n $"Shutting down $KIND services: "
745 killproc smbd
746 RETVAL=$?
747 echo
748 KIND="NMB"
749 echo -n $"Shutting down $KIND services: "
750 killproc nmbd
751 RETVAL2=$?
752 echo
753 KIND="Winbind"
754 echo -n $"Shutting down $KIND services: "
755 killproc winbindd
756 RETVAL3=$?
757 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] &amp;&amp; \
758 rm -f /var/lock/subsys/smb
759 echo ""
760 return $RETVAL
761}
762</pre></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id414403"></a>Solaris</h5></div></div></div><p>
763Winbind does not work on Solaris 9; see <a href="Portability.html#winbind-solaris9" title="Winbind on Solaris 9">Winbind on Solaris 9 section</a>
764for details.
765</p><p>
766<a class="indexterm" name="id414422"></a>
767<a class="indexterm" name="id414429"></a>
768<a class="indexterm" name="id414436"></a>
769<a class="indexterm" name="id414443"></a>
770<a class="indexterm" name="id414450"></a>
771<a class="indexterm" name="id414456"></a>
772On Solaris, you need to modify the <code class="filename">/etc/init.d/samba.server</code> startup script. It
773usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in
774<code class="filename">/usr/local/samba/bin</code>, the file could contains something like this:
775</p><p>
776 </p><pre class="programlisting">
777 ##
778 ## samba.server
779 ##
780
781 if [ ! -d /usr/bin ]
782 then # /usr not mounted
783 exit
784 fi
785
786 killproc() { # kill the named process(es)
787 pid=`/usr/bin/ps -e |
788 /usr/bin/grep -w $1 |
789 /usr/bin/sed -e 's/^ *//' -e 's/ .*//'`
790 [ "$pid" != "" ] &amp;&amp; kill $pid
791 }
792
793 # Start/stop processes required for Samba server
794
795 case "$1" in
796
797 'start')
798 #
799 # Edit these lines to suit your installation (paths, workgroup, host)
800 #
801 echo Starting SMBD
802 /usr/local/samba/bin/smbd -D -s \
803 /usr/local/samba/smb.conf
804
805 echo Starting NMBD
806 /usr/local/samba/bin/nmbd -D -l \
807 /usr/local/samba/var/log -s /usr/local/samba/smb.conf
808
809 echo Starting Winbind Daemon
810 /usr/local/samba/sbin/winbindd
811 ;;
812
813 'stop')
814 killproc nmbd
815 killproc smbd
816 killproc winbindd
817 ;;
818
819 *)
820 echo "Usage: /etc/init.d/samba.server { start | stop }"
821 ;;
822 esac
823</pre><p>
824Again, if you would like to run Samba in dual daemon mode, replace:
825</p><pre class="programlisting">
826/usr/local/samba/sbin/winbindd
827</pre><p>
828in the script above with:
829</p><pre class="programlisting">
830/usr/local/samba/sbin/winbindd -B
831</pre><p>
832</p></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id414522"></a>Restarting</h5></div></div></div><p>
833<a class="indexterm" name="id414530"></a>
834<a class="indexterm" name="id414537"></a>
835If you restart the <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> daemons at this point, you
836should be able to connect to the Samba server as a domain member just as
837if you were a local user.
838</p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id414566"></a>Configure Winbind and PAM</h4></div></div></div><p>
839<a class="indexterm" name="id414573"></a>
840<a class="indexterm" name="id414580"></a>
841<a class="indexterm" name="id414587"></a>
842<a class="indexterm" name="id414594"></a>
843If you have made it this far, you know that <code class="literal">winbindd</code> and Samba are working
844together. If you want to use Winbind to provide authentication for other
845services, keep reading. The PAM configuration files need to be altered in
846this step. (Did you remember to make backups of your original
847<code class="filename">/etc/pam.d</code> files? If not, do it now.)
848</p><p>
849<a class="indexterm" name="id414618"></a>
850<a class="indexterm" name="id414625"></a>
851<a class="indexterm" name="id414631"></a>
852<a class="indexterm" name="id414638"></a>
853<a class="indexterm" name="id414645"></a>
854<a class="indexterm" name="id414652"></a>
855You will need a PAM module to use winbindd with these other services. This
856module will be compiled in the <code class="filename">../source/nsswitch</code> directory
857by invoking the command:
858</p><pre class="screen">
859<code class="prompt">root# </code><strong class="userinput"><code>make nsswitch/pam_winbind.so</code></strong>
860</pre><p>
861from the <code class="filename">../source</code> directory. The
862<code class="filename">pam_winbind.so</code> file should be copied to the location of
863your other PAM security modules. On my Red Hat system, this was the
864<code class="filename">/lib/security</code> directory. On Solaris, the PAM security
865modules reside in <code class="filename">/usr/lib/security</code>.
866</p><pre class="screen">
867<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</code></strong>
868</pre><p>
869</p><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id414724"></a>Linux/FreeBSD-Specific PAM Configuration</h5></div></div></div><p>
870<a class="indexterm" name="id414732"></a>
871The <code class="filename">/etc/pam.d/samba</code> file does not need to be changed. I
872just left this file as it was:
873</p><pre class="programlisting">
874auth required /lib/security/pam_stack.so service=system-auth
875account required /lib/security/pam_stack.so service=system-auth
876</pre><p>
877<a class="indexterm" name="id414755"></a>
878<a class="indexterm" name="id414761"></a>
879<a class="indexterm" name="id414768"></a>
880<a class="indexterm" name="id414775"></a>
881<a class="indexterm" name="id414782"></a>
882<a class="indexterm" name="id414789"></a>
883<a class="indexterm" name="id414795"></a>
884<a class="indexterm" name="id414802"></a>
885<a class="indexterm" name="id414809"></a>
886The other services that I modified to allow the use of Winbind
887as an authentication service were the normal login on the console (or a terminal
888session), telnet logins, and ftp service. In order to enable these
889services, you may first need to change the entries in
890<code class="filename">/etc/xinetd.d</code> (or <code class="filename">/etc/inetd.conf</code>).
891Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this case you need
892to change the lines in <code class="filename">/etc/xinetd.d/telnet</code>
893and <code class="filename">/etc/xinetd.d/wu-ftp</code> from
894</p><pre class="programlisting">
895 enable = no
896</pre><p>
897to
898</p><pre class="programlisting">
899 enable = yes
900</pre><p>
901<a class="indexterm" name="id414857"></a>
902<a class="indexterm" name="id414864"></a>
903<a class="indexterm" name="id414870"></a>
904For ftp services to work properly, you will also need to either
905have individual directories for the domain users already present on
906the server or change the home directory template to a general
907directory for all domain users. These can be easily set using
908the <code class="filename">smb.conf</code> global entry
909<a class="indexterm" name="id414886"></a>template homedir.
910</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
911<a class="indexterm" name="id414897"></a>
912The directory in <a class="indexterm" name="id414904"></a>template homedir is not created automatically! Use pam_mkhomedir or
913pre-create the directories of users to make sure users can log in on UNIX with their own home directory.
914</p></div><p>
915<a class="indexterm" name="id414916"></a>
916<a class="indexterm" name="id414922"></a>
917<a class="indexterm" name="id414929"></a>
918The <code class="filename">/etc/pam.d/ftp</code> file can be changed
919to allow Winbind ftp access in a manner similar to the
920samba file. My <code class="filename">/etc/pam.d/ftp</code> file was
921changed to look like this:
922</p><pre class="programlisting">
923auth required /lib/security/pam_listfile.so item=user sense=deny \
924 file=/etc/ftpusers onerr=succeed
925auth sufficient /lib/security/pam_winbind.so
926auth required /lib/security/pam_stack.so service=system-auth
927auth required /lib/security/pam_shells.so
928account sufficient /lib/security/pam_winbind.so
929account required /lib/security/pam_stack.so service=system-auth
930session required /lib/security/pam_stack.so service=system-auth
931</pre><p>
932<a class="indexterm" name="id414961"></a>
933The <code class="filename">/etc/pam.d/login</code> file can be changed in nearly the
934same way. It now looks like this:
935</p><pre class="programlisting">
936auth required /lib/security/pam_securetty.so
937auth sufficient /lib/security/pam_winbind.so
938auth sufficient /lib/security/pam_unix.so use_first_pass
939auth required /lib/security/pam_stack.so service=system-auth
940auth required /lib/security/pam_nologin.so
941account sufficient /lib/security/pam_winbind.so
942account required /lib/security/pam_stack.so service=system-auth
943password required /lib/security/pam_stack.so service=system-auth
944session required /lib/security/pam_stack.so service=system-auth
945session optional /lib/security/pam_console.so
946</pre><p>
947<a class="indexterm" name="id414985"></a>
948<a class="indexterm" name="id414992"></a>
949<a class="indexterm" name="id414999"></a>
950In this case, I added the </p><pre class="programlisting">auth sufficient /lib/security/pam_winbind.so</pre><p>
951lines as before, but also added the </p><pre class="programlisting">required pam_securetty.so</pre><p>
952above it to disallow root logins over the network. I also added a
953</p><pre class="programlisting">sufficient /lib/security/pam_unix.so use_first_pass</pre><p>
954line after the <code class="literal">winbind.so</code> line to get rid of annoying
955double prompts for passwords.
956</p></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id415034"></a>Solaris-Specific Configuration</h5></div></div></div><p>
957<a class="indexterm" name="id415042"></a>
958<a class="indexterm" name="id415048"></a>
959The <code class="filename">/etc/pam.conf</code> needs to be changed. I changed this file so my Domain
960users can log on both locally as well as with telnet. The following are the changes
961that I made. You can customize the <code class="filename">pam.conf</code> file as per your requirements, but
962be sure of those changes because in the worst case it will leave your system
963nearly impossible to boot.
964</p><pre class="programlisting">
965#
966#ident "@(#)pam.conf 1.14 99/09/16 SMI"
967#
968# Copyright (c) 1996-1999, Sun Microsystems, Inc.
969# All Rights Reserved.
970#
971# PAM configuration
972#
973# Authentication management
974#
975login auth required /usr/lib/security/pam_winbind.so
976login auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
977login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass
978#
979rlogin auth sufficient /usr/lib/security/pam_winbind.so
980rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1
981rlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
982#
983dtlogin auth sufficient /usr/lib/security/pam_winbind.so
984dtlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
985#
986rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1
987other auth sufficient /usr/lib/security/pam_winbind.so
988other auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
989#
990# Account management
991#
992login account sufficient /usr/lib/security/pam_winbind.so
993login account requisite /usr/lib/security/$ISA/pam_roles.so.1
994login account required /usr/lib/security/$ISA/pam_unix.so.1
995#
996dtlogin account sufficient /usr/lib/security/pam_winbind.so
997dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1
998dtlogin account required /usr/lib/security/$ISA/pam_unix.so.1
999#
1000other account sufficient /usr/lib/security/pam_winbind.so
1001other account requisite /usr/lib/security/$ISA/pam_roles.so.1
1002other account required /usr/lib/security/$ISA/pam_unix.so.1
1003#
1004# Session management
1005#
1006other session required /usr/lib/security/$ISA/pam_unix.so.1
1007#
1008# Password management
1009#
1010#other password sufficient /usr/lib/security/pam_winbind.so
1011other password required /usr/lib/security/$ISA/pam_unix.so.1
1012dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1
1013#
1014# Support for Kerberos V5 authentication (uncomment to use Kerberos)
1015#
1016#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
1017#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
1018#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
1019#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
1020#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1
1021#other account optional /usr/lib/security/$ISA/pam_krb5.so.1
1022#other session optional /usr/lib/security/$ISA/pam_krb5.so.1
1023#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
1024</pre><p>
1025<a class="indexterm" name="id415117"></a>
1026I also added a <em class="parameter"><code>try_first_pass</code></em> line after the <code class="filename">winbind.so</code>
1027line to get rid of annoying double prompts for passwords.
1028</p><p>
1029Now restart your Samba and try connecting through your application that you
1030configured in the pam.conf.
1031</p></div></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id415146"></a>Conclusion</h2></div></div></div><p>
1032<a class="indexterm" name="id415154"></a>
1033<a class="indexterm" name="id415160"></a>
1034<a class="indexterm" name="id415167"></a>
1035<a class="indexterm" name="id415174"></a>
1036<a class="indexterm" name="id415180"></a>
1037The Winbind system, through the use of the NSS, PAMs, and appropriate
1038Microsoft RPC calls, have allowed us to provide seamless
1039integration of Microsoft Windows NT domain users on a
1040UNIX system. The result is a great reduction in the administrative
1041cost of running a mixed UNIX and NT network.</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id415192"></a>Common Errors</h2></div></div></div><p>Winbind has a number of limitations in its current
1042 released version that we hope to overcome in future
1043 releases:</p><div class="itemizedlist"><ul type="disc"><li><p>Winbind is currently only available for
1044 the Linux, Solaris, AIX, and IRIX operating systems, although ports to other operating
1045 systems are certainly possible. For such ports to be feasible,
1046 we require the C library of the target operating system to
1047 support the NSS and PAM
1048 systems. This is becoming more common as NSS and
1049 PAM gain support among UNIX vendors.</p></li><li><p>The mappings of Windows NT RIDs to UNIX IDs
1050 is not made algorithmically and depends on the order in which
1051 unmapped users or groups are seen by Winbind. It may be difficult
1052 to recover the mappings of RID to UNIX ID if the file
1053 containing this information is corrupted or destroyed.</p></li><li><p>Currently the Winbind PAM module does not take
1054 into account possible workstation and logon time restrictions
1055 that may be set for Windows NT users; this is
1056 instead up to the PDC to enforce.</p></li></ul></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id415226"></a>NSCD Problem Warning</h3></div></div></div><div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
1057 Do not under any circumstances run <code class="literal">nscd</code> on any system
1058 on which <code class="literal">winbindd</code> is running.
1059 </p></div><p>
1060 If <code class="literal">nscd</code> is running on the UNIX/Linux system, then
1061 even though NSSWITCH is correctly configured, it will not be possible to resolve
1062 domain users and groups for file and directory controls.
1063 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id415261"></a>Winbind Is Not Resolving Users and Groups</h3></div></div></div><p>&#8220;<span class="quote">
1064 My <code class="filename">smb.conf</code> file is correctly configured. I have specified
1065 <a class="indexterm" name="id415276"></a>idmap uid = 12000,
1066 and <a class="indexterm" name="id415284"></a>idmap gid = 3000-3500
1067 and <code class="literal">winbind</code> is running. When I do the following, it all works fine.
1068 </span>&#8221;</p><pre class="screen">
1069<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -u</code></strong>
1070MIDEARTH\maryo
1071MIDEARTH\jackb
1072MIDEARTH\ameds
1073...
1074MIDEARTH\root
1075
1076<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -g</code></strong>
1077MIDEARTH\Domain Users
1078MIDEARTH\Domain Admins
1079MIDEARTH\Domain Guests
1080...
1081MIDEARTH\Accounts
1082
1083<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong>
1084root:x:0:0:root:/root:/bin/bash
1085bin:x:1:1:bin:/bin:/bin/bash
1086...
1087maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false
1088</pre><p>&#8220;<span class="quote">
1089But the following command just fails:
1090</span>&#8221;
1091</p><pre class="screen">
1092<code class="prompt">root# </code><strong class="userinput"><code>chown maryo a_file</code></strong>
1093chown: `maryo': invalid user
1094</pre><p>
1095&#8220;<span class="quote">
1096This is driving me nuts! What can be wrong?
1097</span>&#8221;</p><p>
1098Same problem as the one above.
1099Your system is likely running <code class="literal">nscd</code>, the name service
1100caching daemon. Shut it down, do not restart it! You will find your problem resolved.
1101</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>
Note: See TracBrowser for help on using the repository browser.