File: groupmapping.html

package info (click to toggle)
samba 2:3.6.6-6+deb7u7
  • links: PTS, VCS
  • area: main
  • in suites: wheezy
  • size: 160,976 kB
  • sloc: ansic: 1,764,536; xml: 114,867; python: 78,119; perl: 27,633; sh: 13,802; makefile: 4,704; asm: 3,281; cpp: 2,281; yacc: 1,949; exp: 1,784; ada: 1,681; pascal: 1,089; cs: 879; awk: 756; lex: 566; csh: 58; sed: 45; php: 6
file content (505 lines) | stat: -rw-r--r-- 44,444 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter�12.�Group Mapping: MS Windows and UNIX</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="passdb.html" title="Chapter�11.�Account Information Databases"><link rel="next" href="NetCommand.html" title="Chapter�13.�Remote and Local Management: The Net Command"></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�12.�Group Mapping: MS Windows and UNIX</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="passdb.html">Prev</a>�</td><th width="60%" align="center">Part�III.�Advanced Configuration</th><td width="20%" align="right">�<a accesskey="n" href="NetCommand.html">Next</a></td></tr></table><hr></div><div class="chapter" title="Chapter�12.�Group Mapping: MS Windows and UNIX"><div class="titlepage"><div><div><h2 class="title"><a name="groupmapping"></a>Chapter�12.�Group Mapping: MS Windows and UNIX</h2></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><div class="author"><h3 class="author"><span class="firstname">Jean Fran�ois</span> <span class="surname">Micouleau</span></h3></div></div><div><div class="author"><h3 class="author"><span class="firstname">Gerald</span> <span class="othername">(Jerry)</span> <span class="surname">Carter</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:jerry@samba.org">jerry@samba.org</a>&gt;</code></p></div></div></div></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="groupmapping.html#id364981">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="groupmapping.html#id365375">Discussion</a></span></dt><dd><dl><dt><span class="sect2"><a href="groupmapping.html#id365690">Warning: User Private Group Problems</a></span></dt><dt><span class="sect2"><a href="groupmapping.html#id365742">Nested Groups: Adding Windows Domain Groups to Windows Local Groups</a></span></dt><dt><span class="sect2"><a href="groupmapping.html#id366270">Important Administrative Information</a></span></dt><dt><span class="sect2"><a href="groupmapping.html#id366491">Default Users, Groups, and Relative Identifiers</a></span></dt><dt><span class="sect2"><a href="groupmapping.html#id367100">Example Configuration</a></span></dt></dl></dd><dt><span class="sect1"><a href="groupmapping.html#id367172">Configuration Scripts</a></span></dt><dd><dl><dt><span class="sect2"><a href="groupmapping.html#id367182">Sample <code class="filename">smb.conf</code> Add Group Script</a></span></dt><dt><span class="sect2"><a href="groupmapping.html#id367342">Script to Configure Group Mapping</a></span></dt></dl></dd><dt><span class="sect1"><a href="groupmapping.html#id367456">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="groupmapping.html#id367467">Adding Groups Fails</a></span></dt><dt><span class="sect2"><a href="groupmapping.html#id367547">Adding Domain Users to the Workstation Power Users Group</a></span></dt></dl></dd></dl></div><p>
<a class="indexterm" name="id364863"></a>
<a class="indexterm" name="id364872"></a>
<a class="indexterm" name="id364879"></a>
<a class="indexterm" name="id364885"></a>
<a class="indexterm" name="id364892"></a>
<a class="indexterm" name="id364899"></a>
	Starting with Samba-3, new group mapping functionality is available to create associations
	between Windows group SIDs and UNIX group GIDs. The <code class="literal">groupmap</code> subcommand
	included with the <span class="application">net</span> tool can be used to manage these associations.
	</p><p>
<a class="indexterm" name="id364922"></a>
<a class="indexterm" name="id364929"></a>
	The new facility for mapping NT groups to UNIX system groups allows the administrator to decide
	which NT domain groups are to be exposed to MS Windows clients. Only those NT groups that map
	to a UNIX group that has a value other than the default (<code class="constant">-1</code>) will be exposed
	in group selection lists in tools that access domain users and groups.
	</p><div class="warning" title="Warning" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Warning</h3><p>
	<a class="indexterm" name="id364948"></a>
<a class="indexterm" name="id364955"></a>
	The <em class="parameter"><code>domain admin group</code></em> parameter has been removed in Samba-3 and should no longer
	be specified in <code class="filename">smb.conf</code>. In Samba-2.2.x, this parameter was used to give the listed users membership in the
	<code class="constant">Domain Admins</code> Windows group, which gave local admin rights on their workstations
	(in default configurations).
	</p></div><div class="sect1" title="Features and Benefits"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id364981"></a>Features and Benefits</h2></div></div></div><p>
	Samba allows the administrator to create MS Windows NT4/200x group accounts and to
	arbitrarily associate them with UNIX/Linux group accounts.
	</p><p>
	<a class="indexterm" name="id364993"></a>
	<a class="indexterm" name="id364999"></a>
	<a class="indexterm" name="id365006"></a>
<a class="indexterm" name="id365013"></a>
<a class="indexterm" name="id365019"></a>
<a class="indexterm" name="id365026"></a>
<a class="indexterm" name="id365033"></a>
	Group accounts can be managed using the MS Windows NT4 or MS Windows 200x/XP Professional MMC tools.
	Appropriate interface scripts should be provided in <code class="filename">smb.conf</code> if it is desired that UNIX/Linux system
	accounts should be automatically created when these tools are used. In the absence of these scripts, and
	so long as <code class="literal">winbindd</code> is running, Samba group accounts that are created using these
	tools will be allocated UNIX UIDs and GIDs from the ID range specified by the
	<a class="link" href="smb.conf.5.html#IDMAPUID" target="_top">idmap uid</a>/<a class="link" href="smb.conf.5.html#IDMAPGID" target="_top">idmap gid</a>
	parameters in the <code class="filename">smb.conf</code> file.
	</p><div class="figure"><a name="idmap-sid2gid"></a><p class="title"><b>Figure�12.1.�IDMAP: Group SID-to-GID Resolution.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/idmap-sid2gid.png" width="270" alt="IDMAP: Group SID-to-GID Resolution."></div></div></div><br class="figure-break"><div class="figure"><a name="idmap-gid2sid"></a><p class="title"><b>Figure�12.2.�IDMAP: GID Resolution to Matching SID.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/idmap-gid2sid.png" width="270" alt="IDMAP: GID Resolution to Matching SID."></div></div></div><br class="figure-break"><p>
	<a class="indexterm" name="id365170"></a>
<a class="indexterm" name="id365177"></a>
<a class="indexterm" name="id365184"></a>
<a class="indexterm" name="id365193"></a>
	In both cases, when winbindd is not running, only locally resolvable groups can be recognized. Please refer to
	<a class="link" href="groupmapping.html#idmap-sid2gid" title="Figure�12.1.�IDMAP: Group SID-to-GID Resolution.">IDMAP: Group SID-to-GID Resolution</a> and <a class="link" href="groupmapping.html#idmap-gid2sid" title="Figure�12.2.�IDMAP: GID Resolution to Matching SID.">IDMAP: GID Resolution to Matching SID</a>.  The <code class="literal">net groupmap</code> is
	used to establish UNIX group to NT SID mappings as shown in <a class="link" href="groupmapping.html#idmap-store-gid2sid" title="Figure�12.3.�IDMAP Storing Group Mappings.">IDMAP: storing
	group mappings</a>.
	</p><div class="figure"><a name="idmap-store-gid2sid"></a><p class="title"><b>Figure�12.3.�IDMAP Storing Group Mappings.</b></p><div class="figure-contents"><div class="mediaobject"><img src="images/idmap-store-gid2sid.png" width="270" alt="IDMAP Storing Group Mappings."></div></div></div><br class="figure-break"><p>
	<a class="indexterm" name="id365273"></a>
	<a class="indexterm" name="id365280"></a>
<a class="indexterm" name="id365286"></a>
<a class="indexterm" name="id365293"></a>
	Administrators should be aware that where <code class="filename">smb.conf</code> group interface scripts make
	direct calls to the UNIX/Linux system tools (the shadow utilities, <code class="literal">groupadd</code>,
	<code class="literal">groupdel</code>, and <code class="literal">groupmod</code>), the resulting UNIX/Linux group names will be subject
	to any limits imposed by these tools. If the tool does not allow uppercase characters
	or space characters, then the creation of an MS Windows NT4/200x-style group of
	<code class="literal">Engineering Managers</code> will attempt to create an identically named
	UNIX/Linux group, an attempt that will of course fail.
	</p><p>
	<a class="indexterm" name="id365337"></a>
	<a class="indexterm" name="id365343"></a>
	There are several possible workarounds for the operating system tools limitation. One
	method is to use a script that generates a name for the UNIX/Linux system group that
	fits the operating system limits and that then just passes the UNIX/Linux group ID (GID)
	back to the calling Samba interface. This will provide a dynamic workaround solution.
	</p><p>
<a class="indexterm" name="id365356"></a>
	Another workaround is to manually create a UNIX/Linux group, then manually create the
	MS Windows NT4/200x group on the Samba server, and then use the <code class="literal">net groupmap</code>
	tool to connect the two to each other.
	</p></div><div class="sect1" title="Discussion"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id365375"></a>Discussion</h2></div></div></div><p>
<a class="indexterm" name="id365383"></a>
<a class="indexterm" name="id365390"></a>
	When you install <span class="application">MS Windows NT4/200x</span> on a computer, the installation
	program creates default users and groups, notably the <code class="constant">Administrators</code> group,
	and gives that group privileges necessary to perform essential system tasks,
	such as the ability to change the date and time or to kill (or close) any process running on the
	local machine.
	</p><p>
	<a class="indexterm" name="id365412"></a>
	The <code class="constant">Administrator</code> user is a member of the <code class="constant">Administrators</code> group, and thus inherits
	<code class="constant">Administrators</code> group privileges. If a <code class="constant">joe</code> user is created to be a member of the
	<code class="constant">Administrators</code> group, <code class="constant">joe</code> has exactly the same rights as the user
	<code class="constant">Administrator</code>.
	</p><p>
<a class="indexterm" name="id365449"></a>
<a class="indexterm" name="id365456"></a>
<a class="indexterm" name="id365462"></a>
<a class="indexterm" name="id365469"></a>
	When an MS Windows NT4/200x/XP machine is made a domain member, the <span class="quote">&#8220;<span class="quote">Domain Admins</span>&#8221;</span> group of the
	PDC is added to the local <code class="constant">Administrators</code> group of the workstation. Every member of the
	<code class="constant">Domain Admins</code> group inherits the rights of the local <code class="constant">Administrators</code> group when
	logging on the workstation.
	</p><p>
<a class="indexterm" name="id365496"></a>
<a class="indexterm" name="id365502"></a>
	The following steps describe how to make Samba PDC users members of the <code class="constant">Domain Admins</code> group.
	</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>
		Create a UNIX group (usually in <code class="filename">/etc/group</code>); let's call it <code class="constant">domadm</code>.
		</p></li><li class="listitem"><p>
<a class="indexterm" name="id365539"></a>
		Add to this group the users that must be <span class="quote">&#8220;<span class="quote">Administrators</span>&#8221;</span>. For example,
		if you want <code class="constant">joe, john</code>, and <code class="constant">mary</code> to be administrators,
		your entry in <code class="filename">/etc/group</code> will look like this:
		</p><pre class="programlisting">
		domadm:x:502:joe,john,mary
		</pre><p>
		</p></li><li class="listitem"><p>
		Map this domadm group to the <span class="quote">&#8220;<span class="quote">Domain Admins</span>&#8221;</span> group by executing the command:
		</p><p>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>net groupmap add ntgroup="Domain Admins" unixgroup=domadm rid=512 type=d</code></strong>
</pre><p>
		</p><p>
		<a class="indexterm" name="id365603"></a>
		The quotes around <span class="quote">&#8220;<span class="quote">Domain Admins</span>&#8221;</span> are necessary due to the space in the group name.
		Also make sure to leave no white space surrounding the equal character (=).
		</p></li></ol></div><p>
	Now <code class="constant">joe, john</code>, and <code class="constant">mary</code> are domain administrators.
	</p><p>
	<a class="indexterm" name="id365630"></a>
	It is possible to map any arbitrary UNIX group to any Windows NT4/200x group as well as
	to make any UNIX group a Windows domain group. For example, if you wanted to include a
	UNIX group (e.g., acct) in an ACL on a local file or printer on a Domain Member machine,
	you would flag that group as a domain group by running the following on the Samba PDC:
	</p><p>
</p><pre class="screen">
<code class="prompt">root# </code><strong class="userinput"><code>net groupmap add rid=1000 ntgroup="Accounting" unixgroup=acct type=d</code></strong>
</pre><p>
	The <code class="literal">ntgroup</code> value must be in quotes if it contains space characters to prevent
	the space from being interpreted as a command delimiter.
	</p><p>
<a class="indexterm" name="id365672"></a>
<a class="indexterm" name="id365679"></a>
	Be aware that the RID parameter is an unsigned 32-bit integer that should
	normally start at 1000. However, this RID must not overlap with any RID assigned
	to a user. Verification for this is done differently depending on the passdb backend
	you are using. Future versions of the tools may perform the verification automatically,
	but for now the burden is on you.
	</p><div class="sect2" title="Warning: User Private Group Problems"><div class="titlepage"><div><div><h3 class="title"><a name="id365690"></a>Warning: User Private Group Problems</h3></div></div></div><p>
<a class="indexterm" name="id365698"></a>
<a class="indexterm" name="id365704"></a>
<a class="indexterm" name="id365711"></a>
	Windows does not permit user and group accounts to have the same name.
	This has serious implications for all sites that use private group accounts.
	A private group account is an administrative practice whereby users are each
	given their own group account. Red Hat Linux, as well as several free distributions
	of Linux, by default create private groups.
	</p><p>
<a class="indexterm" name="id365724"></a>
<a class="indexterm" name="id365731"></a>
	When mapping a UNIX/Linux group to a Windows group account, all conflict can
	be avoided by assuring that the Windows domain group name does not overlap
	with any user account name.
	</p></div><div class="sect2" title="Nested Groups: Adding Windows Domain Groups to Windows Local Groups"><div class="titlepage"><div><div><h3 class="title"><a name="id365742"></a>Nested Groups: Adding Windows Domain Groups to Windows Local Groups</h3></div></div></div><a class="indexterm" name="id365748"></a><p>
<a class="indexterm" name="id365759"></a>
	This functionality is known as <code class="constant">nested groups</code> and was first added to
	Samba-3.0.3.
	</p><p>
<a class="indexterm" name="id365774"></a>
	All MS Windows products since the release of Windows NT 3.10 support the use of nested groups.
	Many Windows network administrators depend on this capability because it greatly simplifies security
	administration.
	</p><p>
<a class="indexterm" name="id365786"></a>
<a class="indexterm" name="id365792"></a>
<a class="indexterm" name="id365799"></a>
<a class="indexterm" name="id365806"></a>
<a class="indexterm" name="id365813"></a>
<a class="indexterm" name="id365820"></a>
<a class="indexterm" name="id365826"></a>
	The nested group architecture was designed with the premise that day-to-day user and group membership
	management should be performed on the domain security database. The application of group security
	should be implemented on domain member servers using only local groups. On the domain member server,
	all file system security controls are then limited to use of the local groups, which will contain
	domain global groups and domain global users.
	</p><p>
<a class="indexterm" name="id365840"></a>
<a class="indexterm" name="id365847"></a>
<a class="indexterm" name="id365854"></a>
	You may ask, What are the benefits of this arrangement? The answer is obvious to those who have plumbed
	the dark depths of Windows networking architecture. Consider for a moment a server on which are stored
	200,000 files, each with individual domain user and domain group settings. The company that owns the
	file server is bought by another company, resulting in the server being moved to another location, and then
	it is made a member of a different domain. Who would you think now owns all the files and directories?
	Answer: Account Unknown.
	</p><p>
<a class="indexterm" name="id365869"></a>
<a class="indexterm" name="id365876"></a>
<a class="indexterm" name="id365882"></a>
<a class="indexterm" name="id365889"></a>
	Unraveling the file ownership mess is an unenviable administrative task that can be avoided simply
	by using local groups to control all file and directory access control. In this case, only the members
	of the local groups will have been lost. The files and directories in the storage subsystem will still
	be owned by the local groups. The same goes for all ACLs on them. It is administratively much simpler
	to delete the <code class="constant">Account Unknown</code> membership entries inside local groups with appropriate
	entries for domain global groups in the new domain that the server has been made a member of.
	</p><p>
<a class="indexterm" name="id365908"></a>
<a class="indexterm" name="id365914"></a>
<a class="indexterm" name="id365921"></a>
<a class="indexterm" name="id365928"></a>
<a class="indexterm" name="id365935"></a>
<a class="indexterm" name="id365942"></a>
<a class="indexterm" name="id365949"></a>
<a class="indexterm" name="id365955"></a>
	Another prominent example of the use of nested groups involves implementation of administrative privileges
	on domain member workstations and servers. Administrative privileges are given to all members of the
	built-in local group <code class="constant">Administrators</code> on each domain member machine. To ensure that all domain
	administrators have full rights on the member server or workstation, on joining the domain, the
	<code class="constant">Domain Admins</code> group is added to the local Administrators group. Thus everyone who is
	logged into the domain as a member of the Domain Admins group is also granted local administrative
	privileges on each domain member.
	</p><p>
<a class="indexterm" name="id365978"></a>
<a class="indexterm" name="id365985"></a>
<a class="indexterm" name="id365992"></a>
<a class="indexterm" name="id365998"></a>
	UNIX/Linux has no concept of support for nested groups, and thus Samba has for a long time not supported
	them either. The problem is that you would have to enter UNIX groups as auxiliary members of a group in
	<code class="filename">/etc/group</code>. This does not work because it was not a design requirement at the time
	the UNIX file system security model was implemented. Since Samba-2.2, the winbind daemon can provide
	<code class="filename">/etc/group</code> entries on demand by obtaining user and group information from the domain
	controller that the Samba server is a member of.
	</p><p>
<a class="indexterm" name="id366024"></a>
<a class="indexterm" name="id366031"></a>
<a class="indexterm" name="id366038"></a>
<a class="indexterm" name="id366045"></a>
<a class="indexterm" name="id366052"></a>
	In effect, Samba supplements the <code class="filename">/etc/group</code> data via the dynamic
	<code class="literal">libnss_winbind</code> mechanism. Beginning with Samba-3.0.3, this facility is used to provide
	local groups in the same manner as Windows. It works by expanding the local groups on the
	fly as they are accessed. For example, the <code class="constant">Domain Users</code> group of the domain is made
	a member of the local group <code class="constant">demo</code>. Whenever Samba needs to resolve membership of the
	<code class="constant">demo</code> local (alias) group, winbind asks the domain controller for demo members of the Domain Users
	group. By definition, it can only contain user objects, which can then be faked to be member of the
	UNIX/Linux group <code class="constant">demo</code>.
	</p><p>
<a class="indexterm" name="id366093"></a>
<a class="indexterm" name="id366099"></a>
<a class="indexterm" name="id366106"></a>
<a class="indexterm" name="id366113"></a>
<a class="indexterm" name="id366120"></a>
<a class="indexterm" name="id366126"></a>
<a class="indexterm" name="id366133"></a>
	To enable the use of nested groups, <code class="literal">winbindd</code> must be used with NSS winbind.
	Creation and administration of the local groups is done best via the Windows Domain User Manager or its
	Samba equivalent, the utility <code class="literal">net rpc group</code>. Creating the local group
	<code class="constant">demo</code> is achieved by executing:
	</p><pre class="screen">
	<code class="prompt">root# </code> net rpc group add demo -L -Uroot%not24get
	</pre><p>
<a class="indexterm" name="id366174"></a>
<a class="indexterm" name="id366180"></a>
	Here the -L switch means that you want to create a local group. It may be necessary to add -S and -U
	switches for accessing the correct host with appropriate user or root privileges. Adding and removing
	group members can be done via the <code class="constant">addmem</code> and <code class="constant">delmem</code> subcommands of
	<code class="literal">net rpc group</code> command. For example, addition of <span class="quote">&#8220;<span class="quote">DOM\Domain Users</span>&#8221;</span> to the
	local group <code class="constant">demo</code> is done by executing:
	</p><pre class="screen">
	net rpc group addmem demo "DOM\Domain Users"
	</pre><p>
<a class="indexterm" name="id366217"></a>
<a class="indexterm" name="id366223"></a>
<a class="indexterm" name="id366230"></a>
<a class="indexterm" name="id366237"></a>
	Having completed these two steps, the execution of <code class="literal">getent group demo</code> will show demo
	members of the global <code class="constant">Domain Users</code> group as members of  the group
	<code class="constant">demo</code>.  This also works with any local or domain user. In case the domain DOM trusts
	another domain, it is also possible to add global users and groups of the trusted domain as members of
	<code class="constant">demo</code>. The users from the foreign domain who are members of the group that has been
	added to the <code class="constant">demo</code> group now have the same local access permissions as local domain
	users have. 
	</p></div><div class="sect2" title="Important Administrative Information"><div class="titlepage"><div><div><h3 class="title"><a name="id366270"></a>Important Administrative Information</h3></div></div></div><p>
	Administrative rights are necessary in two specific forms:
	</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"><p>For Samba-3 domain controllers and domain member servers/clients.</p></li><li class="listitem"><p>To manage domain member Windows workstations.</p></li></ol></div><p>
<a class="indexterm" name="id366300"></a>
<a class="indexterm" name="id366306"></a>
<a class="indexterm" name="id366313"></a>
	Versions of Samba up to and including 3.0.10 do not provide a means for assigning rights and privileges
	that are necessary for system administration tasks from a Windows domain member client machine, so
	domain administration tasks such as adding, deleting, and changing user and group account information, and
	managing workstation domain membership accounts, can be handled by any account other than root.
	</p><p>
<a class="indexterm" name="id366327"></a>
<a class="indexterm" name="id366334"></a>
<a class="indexterm" name="id366340"></a>
	Samba-3.0.11 introduced a new privilege management interface (see <a class="link" href="rights.html" title="Chapter�15.�User Rights and Privileges">User Rights and Privileges</a>)
	that permits these tasks to be delegated to non-root (i.e., accounts other than the equivalent of the
	MS Windows Administrator) accounts.
	</p><p>
<a class="indexterm" name="id366360"></a>
<a class="indexterm" name="id366366"></a>
	Administrative tasks on a Windows domain member workstation can be done by anyone who is a member of the
	<code class="constant">Domain Admins</code> group. This group can be mapped to any convenient UNIX group.
	</p><div class="sect3" title="Applicable Only to Versions Earlier than 3.0.11"><div class="titlepage"><div><div><h4 class="title"><a name="id366379"></a>Applicable Only to Versions Earlier than 3.0.11</h4></div></div></div><p>
<a class="indexterm" name="id366387"></a>
	Administrative tasks on UNIX/Linux systems, such as adding users or groups, requires
	<code class="constant">root</code>-level privilege. The addition of a Windows client to a Samba domain involves the
	addition of a user account for the Windows client.
	</p><p>
<a class="indexterm" name="id366403"></a>
<a class="indexterm" name="id366410"></a>
	Many UNIX administrators continue to request that the Samba Team make it possible to add Windows workstations, or 
	the ability to add, delete, or modify user accounts, without requiring <code class="constant">root</code> privileges. 
	Such a request violates every understanding of basic UNIX system security.
	</p><p>
<a class="indexterm" name="id366426"></a>
<a class="indexterm" name="id366432"></a>
<a class="indexterm" name="id366439"></a>
<a class="indexterm" name="id366446"></a>
<a class="indexterm" name="id366453"></a>
<a class="indexterm" name="id366460"></a>
	There is no safe way to provide access on a UNIX/Linux system without providing
	<code class="constant">root</code>-level privileges. Provision of <code class="constant">root</code> privileges can be done
	either by logging on to the Domain as the user <code class="constant">root</code> or by permitting particular users to
	use a UNIX account that has a UID=0 in the <code class="filename">/etc/passwd</code> database. Users of such accounts
	can use tools like the NT4 Domain User Manager and the NT4 Domain Server Manager to manage user and group
	accounts as well as domain member server and client accounts. This level of privilege is also needed to manage
	share-level ACLs.
	</p></div></div><div class="sect2" title="Default Users, Groups, and Relative Identifiers"><div class="titlepage"><div><div><h3 class="title"><a name="id366491"></a>Default Users, Groups, and Relative Identifiers</h3></div></div></div><p>
	<a class="indexterm" name="id366499"></a>
	<a class="indexterm" name="id366508"></a>
<a class="indexterm" name="id366514"></a>
<a class="indexterm" name="id366521"></a>
<a class="indexterm" name="id366528"></a>
<a class="indexterm" name="id366535"></a>
<a class="indexterm" name="id366542"></a>
<a class="indexterm" name="id366548"></a>
	When first installed, Windows NT4/200x/XP are preconfigured with certain user, group, and
	alias entities. Each has a well-known RID. These must be preserved for continued
	integrity of operation. Samba must be provisioned with certain essential domain groups that require
	the appropriate RID value. When Samba-3 is configured to use <code class="constant">tdbsam</code>, the essential
	domain groups are automatically created. It is the LDAP administrator's responsibility to create
	(provision) the default NT groups.
	</p><p>
<a class="indexterm" name="id366566"></a>
<a class="indexterm" name="id366573"></a>
<a class="indexterm" name="id366580"></a>
<a class="indexterm" name="id366587"></a>
	Each essential domain group must be assigned its respective well-known RID. The default users, groups,
	aliases, and RIDs are shown in <a class="link" href="groupmapping.html#WKURIDS" title="Table�12.1.�Well-Known User Default RIDs">Well-Known User Default RIDs</a>.
	</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
<a class="indexterm" name="id366607"></a>
<a class="indexterm" name="id366613"></a>
<a class="indexterm" name="id366620"></a>
<a class="indexterm" name="id366627"></a>
<a class="indexterm" name="id366634"></a>
	It is the administrator's responsibility to create the essential domain groups and to assign each
	its default RID.
	</p></div><p>
<a class="indexterm" name="id366644"></a>
<a class="indexterm" name="id366651"></a>
	It is permissible to create any domain group that may be necessary; just make certain that the essential
	domain groups (well known) have been created and assigned their default RIDs. Other groups you create may
	be assigned any arbitrary RID you care to use.
	</p><p>
	Be sure to map each domain group to a UNIX system group. That is the only way to ensure that the group
	will be available for use as an NT domain group.
	</p><p>
	</p><div class="table"><a name="WKURIDS"></a><p class="title"><b>Table�12.1.�Well-Known User Default RIDs</b></p><div class="table-contents"><table summary="Well-Known User Default RIDs" border="1"><colgroup><col align="left"><col align="left"><col align="left"><col align="center"></colgroup><thead><tr><th align="left">Well-Known Entity</th><th align="left">RID</th><th align="left">Type</th><th align="center">Essential</th></tr></thead><tbody><tr><td align="left">Domain Administrator</td><td align="left">500</td><td align="left">User</td><td align="center">No</td></tr><tr><td align="left">Domain Guest</td><td align="left">501</td><td align="left">User</td><td align="center">No</td></tr><tr><td align="left">Domain KRBTGT</td><td align="left">502</td><td align="left">User</td><td align="center">No</td></tr><tr><td align="left">Domain Admins</td><td align="left">512</td><td align="left">Group</td><td align="center">Yes</td></tr><tr><td align="left">Domain Users</td><td align="left">513</td><td align="left">Group</td><td align="center">Yes</td></tr><tr><td align="left">Domain Guests</td><td align="left">514</td><td align="left">Group</td><td align="center">Yes</td></tr><tr><td align="left">Domain Computers</td><td align="left">515</td><td align="left">Group</td><td align="center">No</td></tr><tr><td align="left">Domain Controllers</td><td align="left">516</td><td align="left">Group</td><td align="center">No</td></tr><tr><td align="left">Domain Certificate Admins</td><td align="left">517</td><td align="left">Group</td><td align="center">No</td></tr><tr><td align="left">Domain Schema Admins</td><td align="left">518</td><td align="left">Group</td><td align="center">No</td></tr><tr><td align="left">Domain Enterprise Admins</td><td align="left">519</td><td align="left">Group</td><td align="center">No</td></tr><tr><td align="left">Domain Policy Admins</td><td align="left">520</td><td align="left">Group</td><td align="center">No</td></tr><tr><td align="left">Builtin Admins</td><td align="left">544</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin users</td><td align="left">545</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin Guests</td><td align="left">546</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin Power Users</td><td align="left">547</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin Account Operators</td><td align="left">548</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin System Operators</td><td align="left">549</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin Print Operators</td><td align="left">550</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin Backup Operators</td><td align="left">551</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin Replicator</td><td align="left">552</td><td align="left">Alias</td><td align="center">No</td></tr><tr><td align="left">Builtin RAS Servers</td><td align="left">553</td><td align="left">Alias</td><td align="center">No</td></tr></tbody></table></div></div><p><br class="table-break">
	</p></div><div class="sect2" title="Example Configuration"><div class="titlepage"><div><div><h3 class="title"><a name="id367100"></a>Example Configuration</h3></div></div></div><p>
<a class="indexterm" name="id367108"></a>
		You can list the various groups in the mapping database by executing
		<code class="literal">net groupmap list</code>. Here is an example:
		</p><p>
<a class="indexterm" name="id367129"></a>
</p><pre class="screen">
<code class="prompt">root# </code> <strong class="userinput"><code>net groupmap list</code></strong>
Domain Admins (S-1-5-21-2547222302-1596225915-2414751004-512) -&gt; domadmin
Domain Users (S-1-5-21-2547222302-1596225915-2414751004-513) -&gt; domuser
Domain Guests (S-1-5-21-2547222302-1596225915-2414751004-514) -&gt; domguest
</pre><p>
		</p><p>
		For complete details on <code class="literal">net groupmap</code>, refer to the net(8) man page.
		</p></div></div><div class="sect1" title="Configuration Scripts"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id367172"></a>Configuration Scripts</h2></div></div></div><p>
	Everyone needs tools. Some of us like to create our own, others prefer to use canned tools
	(i.e., prepared by someone else for general use). 
	</p><div class="sect2" title="Sample smb.conf Add Group Script"><div class="titlepage"><div><div><h3 class="title"><a name="id367182"></a>Sample <code class="filename">smb.conf</code> Add Group Script</h3></div></div></div><p>
		<a class="indexterm" name="id367196"></a>
		<a class="indexterm" name="id367202"></a>
		<a class="indexterm" name="id367209"></a>
<a class="indexterm" name="id367216"></a>
<a class="indexterm" name="id367223"></a>
		A script to create complying group names for use by the Samba group interfaces
		is provided in <a class="link" href="groupmapping.html#smbgrpadd.sh" title="Example�12.1.�smbgrpadd.sh">smbgrpadd.sh</a>. This script
		adds a temporary entry in the <code class="filename">/etc/group</code> file and then renames
		it to the desired name. This is an example of a method to get around operating
		system maintenance tool limitations such as those present in some version of the
		<code class="literal">groupadd</code> tool.
</p><div class="example"><a name="smbgrpadd.sh"></a><p class="title"><b>Example�12.1.�smbgrpadd.sh</b></p><div class="example-contents"><pre class="programlisting">
#!/bin/bash

# Add the group using normal system groupadd tool.
groupadd smbtmpgrp00

thegid=`cat /etc/group | grep ^smbtmpgrp00 | cut -d ":" -f3`

# Now change the name to what we want for the MS Windows networking end
cp /etc/group /etc/group.bak
cat /etc/group.bak | sed "s/^smbtmpgrp00/$1/g" &gt; /etc/group
rm /etc/group.bak

# Now return the GID as would normally happen.
echo $thegid
exit 0
</pre></div></div><p><br class="example-break">
</p><p>
		The <code class="filename">smb.conf</code> entry for the above script shown in <a class="link" href="groupmapping.html#smbgrpadd" title="Example�12.2.�Configuration of smb.conf for the add group Script">the configuration of
		<code class="filename">smb.conf</code> for the add group Script</a> demonstrates how it may be used.

</p><div class="example"><a name="smbgrpadd"></a><p class="title"><b>Example�12.2.�Configuration of <code class="filename">smb.conf</code> for the add group Script</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><a class="indexterm" name="id367327"></a><em class="parameter"><code>add group script = /path_to_tool/smbgrpadd.sh "%g"</code></em></td></tr></table></div></div><p><br class="example-break">
		</p></div><div class="sect2" title="Script to Configure Group Mapping"><div class="titlepage"><div><div><h3 class="title"><a name="id367342"></a>Script to Configure Group Mapping</h3></div></div></div><p>
<a class="indexterm" name="id367350"></a>
	In our example we have created a UNIX/Linux group called <code class="literal">ntadmin</code>.
	Our script will create the additional groups <code class="literal">Orks</code>, <code class="literal">Elves</code>, and <code class="literal">Gnomes</code>.
	It is a good idea to save this shell script for later use just in case you ever need to rebuild your mapping database.
	For the sake of convenience we elect to save this script as a file called <code class="filename">initGroups.sh</code>.
	This script is given in <a class="link" href="groupmapping.html#set-group-map" title="Example�12.3.�Script to Set Group Mapping">intGroups.sh</a>.
<a class="indexterm" name="id367397"></a>
</p><div class="example"><a name="set-group-map"></a><p class="title"><b>Example�12.3.�Script to Set Group Mapping</b></p><div class="example-contents"><pre class="programlisting">
#!/bin/bash

net groupmap add ntgroup="Domain Admins" unixgroup=ntadmin rid=512 type=d
net groupmap add ntgroup="Domain Users" unixgroup=users rid=513 type=d
net groupmap add ntgroup="Domain Guests" unixgroup=nobody rid=514 type=d

groupadd Orks
groupadd Elves
groupadd Gnomes

net groupmap add ntgroup="Orks"   unixgroup=Orks   type=d
net groupmap add ntgroup="Elves"  unixgroup=Elves  type=d
net groupmap add ntgroup="Gnomes" unixgroup=Gnomes type=d
</pre></div></div><p><br class="example-break">
	</p><p>
	Of course it is expected that the administrator will modify this to suit local needs.
	For information regarding the use of the <code class="literal">net groupmap</code> tool please
	refer to the man page.
	</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
	Versions of Samba-3 prior to 3.0.23 automatically create default group mapping for the
	<code class="literal">Domain Admins, Domain Users</code> and <code class="literal">Domain Guests</code> Windows
	groups, but do not map them to UNIX GIDs. This was a cause of administrative confusion and 
	trouble. Commencing with Samba-3.0.23 this anomaly has been fixed - thus all Windows groups
	must now be manually and explicitly created and mapped to a valid UNIX GID by the Samba 
	administrator.
	</p></div></div></div><div class="sect1" title="Common Errors"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id367456"></a>Common Errors</h2></div></div></div><p>
At this time there are many little surprises for the unwary administrator. In a real sense
it is imperative that every step of automated control scripts be carefully tested
manually before putting it into active service.
</p><div class="sect2" title="Adding Groups Fails"><div class="titlepage"><div><div><h3 class="title"><a name="id367467"></a>Adding Groups Fails</h3></div></div></div><p>
<a class="indexterm" name="id367475"></a>
		This is a common problem when the <code class="literal">groupadd</code> is called directly
		by the Samba interface script for the <a class="link" href="smb.conf.5.html#ADDGROUPSCRIPT" target="_top">add group script</a> in
		the <code class="filename">smb.conf</code> file.
		</p><p>
<a class="indexterm" name="id367510"></a>
<a class="indexterm" name="id367517"></a>
		The most common cause of failure is an attempt to add an MS Windows group account
		that has an uppercase character and/or a space character in it.
		</p><p>
<a class="indexterm" name="id367528"></a>
		There are three possible workarounds. First, use only group names that comply
		with the limitations of the UNIX/Linux <code class="literal">groupadd</code> system tool.
		Second, it involves the use of the script mentioned earlier in this chapter, and
		third is the option is to manually create a UNIX/Linux group account that can substitute
		for the MS Windows group name, then use the procedure listed above to map that group
		to the MS Windows group.
		</p></div><div class="sect2" title="Adding Domain Users to the Workstation Power Users Group"><div class="titlepage"><div><div><h3 class="title"><a name="id367547"></a>Adding Domain Users to the Workstation Power Users Group</h3></div></div></div><p><span class="quote">&#8220;<span class="quote">
		What must I do to add domain users to the Power Users group?
		</span>&#8221;</span></p><p>
<a class="indexterm" name="id367560"></a>
		The Power Users group is a group that is local to each Windows 200x/XP Professional workstation.
		You cannot add the Domain Users group to the Power Users group automatically, it must be done on
		each workstation by logging in as the local workstation <span class="emphasis"><em>administrator</em></span> and
		then using the following procedure:
		</p><div class="procedure"><ol class="procedure" type="1"><li class="step" title="Step 1"><p>
			Click <span class="guimenu">Start -&gt; Control Panel -&gt; Users and Passwords</span>.
			</p></li><li class="step" title="Step 2"><p>
			Click the <span class="guimenuitem">Advanced</span> tab.
			</p></li><li class="step" title="Step 3"><p>
			Click the <span class="guibutton">Advanced</span> button.
			</p></li><li class="step" title="Step 4"><p>
			Click <code class="constant">Groups</code>.
			</p></li><li class="step" title="Step 5"><p>
			Double-click <code class="constant">Power Users</code>. This will launch the panel to add users or groups
			to the local machine <code class="constant">Power Users</code> group.
			</p></li><li class="step" title="Step 6"><p>
			Click the <span class="guibutton">Add</span> button.
			</p></li><li class="step" title="Step 7"><p>
			Select the domain from which the <code class="constant">Domain Users</code> group is to be added.
			</p></li><li class="step" title="Step 8"><p>
			Double-click the <code class="constant">Domain Users</code> group.
			</p></li><li class="step" title="Step 9"><p>
			Click the <span class="guibutton">OK</span> button. If a logon box is presented during this process, 
			please remember to enter the connect as <code class="constant">DOMAIN\UserName</code>, that is, for the
			domain <code class="constant">MIDEARTH</code> and the user <code class="constant">root</code> enter
			<code class="constant">MIDEARTH\root</code>.
			</p></li></ol></div></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="passdb.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="NetCommand.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter�11.�Account Information Databases�</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">�Chapter�13.�Remote and Local Management: The Net Command</td></tr></table></div></body></html>