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 V1.74.0"><link rel="home" href="index.html" title="The Official Samba 3.5.x HOWTO and Reference Guide"><link rel="up" href="optional.html" title="Part�III.�Advanced Configuration"><link rel="prev" href="VFS.html" title="Chapter�23.�Stackable VFS modules"><link rel="next" href="AdvancedNetworkManagement.html" title="Chapter�25.�Advanced Network Management"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter�24.�Winbind: Use of Domain Accounts</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="VFS.html">Prev</a>�</td><th width="60%" align="center">Part�III.�Advanced Configuration</th><td width="20%" align="right">�<a accesskey="n" href="AdvancedNetworkManagement.html">Next</a></td></tr></table><hr></div><div class="chapter" 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="orgname">Samba Team</span> <span class="surname">Potter</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:tpot@linuxcare.com.au">tpot@linuxcare.com.au</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Andrew</span> <span class="orgname">Samba Team</span> <span class="surname">Tridgell</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:tridge@samba.org">tridge@samba.org</a>></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"><<a class="email" href="mailto:getnag@rediffmail.com">getnag@rediffmail.com</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="orgname">SNAP</span> <span class="surname">Trostel</span></h3><div class="affiliation"><span class="orgname">SNAP<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:jtrostel@snapserver.com">jtrostel@snapserver.com</a>></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="orgname">The Samba Team</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"><<a class="email" href="mailto:jelmer@samba.org">jelmer@samba.org</a>></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="orgname">Samba Team</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:jht@samba.org">jht@samba.org</a>></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#id2652992">Features and Benefits</a></span></dt><dt><span class="sect1"><a href="winbind.html#id2653341">Introduction</a></span></dt><dt><span class="sect1"><a href="winbind.html#id2653431">What Winbind Provides</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id2653584">Target Uses</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2653629">Handling of Foreign SIDs</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id2653755">How Winbind Works</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id2653805">Microsoft Remote Procedure Calls</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2653892">Microsoft Active Directory Services</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2653940">Name Service Switch</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2654172">Pluggable Authentication Modules</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2654327">User and Group ID Allocation</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2654403">Result Caching</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id2654460">Installation and Configuration</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id2654466">Introduction</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2654580">Requirements</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2654732">Testing Things Out</a></span></dt></dl></dd><dt><span class="sect1"><a href="winbind.html#id2657151">Conclusion</a></span></dt><dt><span class="sect1"><a href="winbind.html#id2657199">Common Errors</a></span></dt><dd><dl><dt><span class="sect2"><a href="winbind.html#id2657241">NSCD Problem Warning</a></span></dt><dt><span class="sect2"><a href="winbind.html#id2657278">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="id2652992"></a>Features and Benefits</h2></div></div></div><p> 2<a class="indexterm" name="id2653000"></a> 3<a class="indexterm" name="id2653007"></a> 4 Integration of UNIX and Microsoft Windows NT through a unified logon has 5 been considered a “<span class="quote">holy grail</span>” in heterogeneous computing environments for 6 a long time. 7 </p><p> 8<a class="indexterm" name="id2653024"></a> 9<a class="indexterm" name="id2653031"></a> 10<a class="indexterm" name="id2653038"></a> 11<a class="indexterm" name="id2653044"></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="id2653059"></a> 18<a class="indexterm" name="id2653069"></a> 19<a class="indexterm" name="id2653076"></a> 20<a class="indexterm" name="id2653082"></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="id2653110"></a> 31<a class="indexterm" name="id2653117"></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="id2653131"></a> 37<a class="indexterm" name="id2653138"></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="id2653151"></a> 41<a class="indexterm" name="id2653157"></a> 42<a class="indexterm" name="id2653164"></a> 43<a class="indexterm" name="id2653170"></a> 44<a class="indexterm" name="id2653177"></a> 45<a class="indexterm" name="id2653184"></a> 46<a class="indexterm" name="id2653191"></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="id2653226"></a> 56 <a class="indexterm" name="id2653232"></a> 57<a class="indexterm" name="id2653242"></a> 58<a class="indexterm" name="id2653248"></a> 59<a class="indexterm" name="id2653255"></a> 60<a class="indexterm" name="id2653262"></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="id2653341"></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="id2653357"></a> 71<a class="indexterm" name="id2653364"></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="id2653408"></a> 85<a class="indexterm" name="id2653415"></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="id2653431"></a>What Winbind Provides</h2></div></div></div><p> 93<a class="indexterm" name="id2653439"></a> 94<a class="indexterm" name="id2653446"></a> 95<a class="indexterm" name="id2653452"></a> 96<a class="indexterm" name="id2653459"></a> 97 Winbind unifies UNIX and Windows NT account management by 98 allowing a UNIX box to become a full member of an NT domain. Once 99 this is done, the UNIX box will see NT users and groups as if 100 they were “<span class="quote">native</span>” UNIX users and groups, allowing the NT domain 101 to be used in much the same manner that NIS+ is used within 102 UNIX-only environments.</p><p> 103<a class="indexterm" name="id2653479"></a> 104<a class="indexterm" name="id2653486"></a> 105<a class="indexterm" name="id2653492"></a> 106<a class="indexterm" name="id2653499"></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="id2653516"></a> 116<a class="indexterm" name="id2653523"></a> 117 Users on the UNIX machine can then use NT user and group 118 names as they would “<span class="quote">native</span>” UNIX names. They can chown files 119 so they are owned by NT domain users or even login to the 120 UNIX machine and run a UNIX X-Window session as a domain user.</p><p> 121<a class="indexterm" name="id2653541"></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="id2653563"></a> 128<a class="indexterm" name="id2653570"></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="id2653584"></a>Target Uses</h3></div></div></div><p> 134<a class="indexterm" name="id2653592"></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="id2653609"></a> 143<a class="indexterm" name="id2653615"></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="id2653629"></a>Handling of Foreign SIDs</h3></div></div></div><p> 149<a class="indexterm" name="id2653637"></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="id2653655"></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="id2653667"></a> 160 Response: “<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>” 163 </p><p> 164<a class="indexterm" name="id2653684"></a> 165<a class="indexterm" name="id2653691"></a> 166<a class="indexterm" name="id2653698"></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="id2653714"></a> 173<a class="indexterm" name="id2653720"></a> 174<a class="indexterm" name="id2653727"></a> 175<a class="indexterm" name="id2653734"></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="id2653755"></a>How Winbind Works</h2></div></div></div><p> 185<a class="indexterm" name="id2653763"></a> 186<a class="indexterm" name="id2653770"></a> 187<a class="indexterm" name="id2653777"></a> 188<a class="indexterm" name="id2653783"></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="id2653805"></a>Microsoft Remote Procedure Calls</h3></div></div></div><p> 195<a class="indexterm" name="id2653814"></a> 196<a class="indexterm" name="id2653823"></a> 197<a class="indexterm" name="id2653830"></a> 198<a class="indexterm" name="id2653837"></a> 199<a class="indexterm" name="id2653844"></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="id2653863"></a> 207<a class="indexterm" name="id2653869"></a> 208<a class="indexterm" name="id2653876"></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="id2653892"></a>Microsoft Active Directory Services</h3></div></div></div><p> 214<a class="indexterm" name="id2653900"></a> 215<a class="indexterm" name="id2653907"></a> 216<a class="indexterm" name="id2653914"></a> 217<a class="indexterm" name="id2653921"></a> 218 Since late 2001, Samba has gained the ability to interact with Microsoft Windows 2000 using its “<span class="quote">native 219 mode</span>” protocols rather than the NT4 RPC services. Using LDAP and Kerberos, a domain member running 220 Winbind can enumerate users and groups in exactly the same way as a Windows 200x client would, and in so doing 221 provide a much more efficient and effective Winbind implementation. 222 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2653940"></a>Name Service Switch</h3></div></div></div><p> 223<a class="indexterm" name="id2653948"></a> 224<a class="indexterm" name="id2653954"></a> 225<a class="indexterm" name="id2653961"></a> 226<a class="indexterm" name="id2653968"></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="id2653986"></a> 236<a class="indexterm" name="id2653993"></a> 237<a class="indexterm" name="id2654000"></a> 238<a class="indexterm" name="id2654007"></a> 239<a class="indexterm" name="id2654014"></a> 240 The NSS application programming interface allows Winbind to present itself as a source of system 241 information when resolving UNIX usernames and groups. Winbind uses this interface and information obtained 242 from a Windows NT server using MSRPC calls to provide a new source of account enumeration. Using standard UNIX 243 library calls, you can enumerate the users and groups on a UNIX machine running Winbind and see all users and 244 groups in an NT domain plus any trusted domain as though they were local users and groups. 245 </p><p> 246<a class="indexterm" name="id2654033"></a> 247<a class="indexterm" name="id2654039"></a> 248<a class="indexterm" name="id2654046"></a> 249 The primary control file for NSS is <code class="filename">/etc/nsswitch.conf</code>. When a UNIX application 250 makes a request to do a lookup, the C library looks in <code class="filename">/etc/nsswitch.conf</code> for a line that 251 matches the service type being requested; for example, the “<span class="quote">passwd</span>” service type is used when 252 user or group names are looked up. This config line specifies which implementations of that service should be 253 tried and in what order. If the passwd config line is: 254</p><pre class="screen"> 255passwd: files example 256</pre><p> 257<a class="indexterm" name="id2654082"></a> 258<a class="indexterm" name="id2654089"></a> 259<a class="indexterm" name="id2654096"></a> 260 then the C library will first load a module called <code class="filename">/lib/libnss_files.so</code> followed 261 by the module <code class="filename">/lib/libnss_example.so</code>. The C library will dynamically load each of these 262 modules in turn and call resolver functions within the modules to try to resolve the request. Once the request 263 is resolved, the C library returns the result to the application. 264 </p><p> 265<a class="indexterm" name="id2654123"></a> 266<a class="indexterm" name="id2654130"></a> 267<a class="indexterm" name="id2654137"></a> 268 This NSS interface provides an easy way for Winbind to hook into the operating system. All that needs 269 to be done is to put <code class="filename">libnss_winbind.so</code> in <code class="filename">/lib/</code> then add 270 “<span class="quote">winbind</span>” into <code class="filename">/etc/nsswitch.conf</code> at the appropriate place. The C library 271 will then call Winbind to resolve user and group names. 272 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2654172"></a>Pluggable Authentication Modules</h3></div></div></div><p> 273<a class="indexterm" name="id2654180"></a> 274<a class="indexterm" name="id2654187"></a> 275<a class="indexterm" name="id2654194"></a> 276<a class="indexterm" name="id2654201"></a> 277 PAMs provide a system for abstracting authentication and authorization technologies. With a PAM 278 module, it is possible to specify different authentication methods for different system applications without 279 having to recompile these applications. PAM is also useful for implementing a particular policy for 280 authorization. For example, a system administrator may only allow console logins from users stored in the 281 local password file but only allow users resolved from an NIS database to log in over the network. 282 </p><p> 283<a class="indexterm" name="id2654220"></a> 284<a class="indexterm" name="id2654226"></a> 285<a class="indexterm" name="id2654233"></a> 286<a class="indexterm" name="id2654240"></a> 287<a class="indexterm" name="id2654247"></a> 288 Winbind uses the authentication management and password management PAM interface to integrate Windows 289 NT users into a UNIX system. This allows Windows NT users to log in to a UNIX machine and be authenticated 290 against a suitable PDC. These users can also change their passwords and have this change take effect directly 291 on the PDC. 292 </p><p> 293<a class="indexterm" name="id2654262"></a> 294<a class="indexterm" name="id2654269"></a> 295<a class="indexterm" name="id2654276"></a> 296<a class="indexterm" name="id2654283"></a> 297 PAM is configured by providing control files in the directory <code class="filename">/etc/pam.d/</code> for 298 each of the services that require authentication. When an authentication request is made by an application, 299 the PAM code in the C library looks up this control file to determine what modules to load to do the 300 authentication check and in what order. This interface makes adding a new authentication service for Winbind 301 very easy: simply copy the <code class="filename">pam_winbind.so</code> module to <code class="filename">/lib/security/</code>, 302 and the PAM control files for relevant services are updated to allow authentication via Winbind. See the PAM 303 documentation in <a class="link" href="pam.html" title="Chapter�28.�PAM-Based Distributed Authentication">PAM-Based Distributed Authentication</a>, for more information. 304 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2654327"></a>User and Group ID Allocation</h3></div></div></div><p> 305<a class="indexterm" name="id2654335"></a> 306<a class="indexterm" name="id2654341"></a> 307<a class="indexterm" name="id2654348"></a> 308 When a user or group is created under Windows NT/200x, it is allocated a numerical relative identifier 309 (RID). This is slightly different from UNIX, which has a range of numbers that are used to identify users and 310 the same range used to identify groups. It is Winbind's job to convert RIDs to UNIX ID numbers and vice versa. 311 When Winbind is configured, it is given part of the UNIX user ID space and a part of the UNIX group ID space 312 in which to store Windows NT users and groups. If a Windows NT user is resolved for the first time, it is 313 allocated the next UNIX ID from the range. The same process applies for Windows NT groups. Over time, Winbind 314 will have mapped all Windows NT users and groups to UNIX user IDs and group IDs. 315 </p><p> 316<a class="indexterm" name="id2654371"></a> 317<a class="indexterm" name="id2654378"></a> 318<a class="indexterm" name="id2654384"></a> 319<a class="indexterm" name="id2654391"></a> 320 The results of this mapping are stored persistently in an ID mapping database held in a tdb database. 321 This ensures that RIDs are mapped to UNIX IDs in a consistent way. 322 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2654403"></a>Result Caching</h3></div></div></div><p> 323<a class="indexterm" name="id2654411"></a> 324<a class="indexterm" name="id2654417"></a> 325<a class="indexterm" name="id2654424"></a> 326<a class="indexterm" name="id2654431"></a> 327<a class="indexterm" name="id2654437"></a> 328 An active directory system can generate a lot of user and group name lookups. To reduce the network 329 cost of these lookups, Winbind uses a caching scheme based on the SAM sequence number supplied by NT domain 330 controllers. User or group information returned by a PDC is cached by Winbind along with a sequence number 331 also returned by the PDC. This sequence number is incremented by Windows NT whenever any user or group 332 information is modified. If a cached entry has expired, the sequence number is requested from the PDC and 333 compared against the sequence number of the cached entry. If the sequence numbers do not match, then the 334 cached information is discarded and up-to-date information is requested directly from the PDC. 335 </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2654460"></a>Installation and Configuration</h2></div></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2654466"></a>Introduction</h3></div></div></div><p> 336<a class="indexterm" name="id2654474"></a> 337<a class="indexterm" name="id2654480"></a> 338<a class="indexterm" name="id2654487"></a> 339This section describes the procedures used to get Winbind up and running. Winbind is capable of providing 340access and authentication control for Windows Domain users through an NT or Windows 200x PDC for regular 341services, such as telnet and ftp, as well for Samba services. 342</p><div class="itemizedlist"><ul type="disc"><li><p> 343 <span class="emphasis"><em>Why should I do this?</em></span> 344 </p><p> 345<a class="indexterm" name="id2654513"></a> 346<a class="indexterm" name="id2654520"></a> 347<a class="indexterm" name="id2654527"></a> 348<a class="indexterm" name="id2654534"></a> 349This allows the Samba administrator to rely on the authentication mechanisms on the Windows NT/200x PDC 350for the authentication of domain members. Windows NT/200x users no longer need to have separate accounts on 351the Samba server. 352 </p></li><li><p> 353 <span class="emphasis"><em>Who should be reading this document?</em></span> 354 </p><p> 355<a class="indexterm" name="id2654558"></a> 356<a class="indexterm" name="id2654565"></a> 357This document is designed for system administrators. If you are implementing Samba on a file server and wish 358to (fairly easily) integrate existing Windows NT/200x users from your PDC onto the Samba server, this document 359is for you. 360 </p></li></ul></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2654580"></a>Requirements</h3></div></div></div><p> 361<a class="indexterm" name="id2654588"></a> 362<a class="indexterm" name="id2654594"></a> 363<a class="indexterm" name="id2654601"></a> 364If you have a Samba configuration file that you are currently using, <span class="emphasis"><em>BACK IT UP!</em></span> 365If your system already uses PAM, <span class="emphasis"><em>back up the <code class="filename">/etc/pam.d</code> directory 366contents!</em></span> If you haven't already made a boot disk, <span class="emphasis"><em>MAKE ONE NOW!</em></span> 367</p><p> 368<a class="indexterm" name="id2654631"></a> 369<a class="indexterm" name="id2654638"></a> 370<a class="indexterm" name="id2654645"></a> 371Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's 372why you want to be able to boot back into your machine in single-user mode and restore your 373<code class="filename">/etc/pam.d</code> to the original state it was in if you get frustrated with the 374way things are going. 375</p><p> 376<a class="indexterm" name="id2654666"></a> 377<a class="indexterm" name="id2654672"></a> 378The latest version of Samba-3 includes a functioning winbindd daemon. Please refer to the <a class="ulink" href="http://samba.org/" target="_top">main Samba Web page</a>, or better yet, your closest Samba mirror site for 379instructions on downloading the source code. 380</p><p> 381<a class="indexterm" name="id2654692"></a> 382<a class="indexterm" name="id2654699"></a> 383<a class="indexterm" name="id2654706"></a> 384<a class="indexterm" name="id2654712"></a> 385To allow domain users the ability to access Samba shares and files, as well as potentially other services 386provided by your Samba machine, PAM must be set up properly on your 387machine. In order to compile the Winbind modules, you should have at least the PAM development libraries installed 388on your system. Please refer to the PAM Web site <a class="ulink" href="http://www.kernel.org/pub/linux/libs/pam/" target="_top">http://www.kernel.org/pub/linux/libs/pam/</a>. 389</p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2654732"></a>Testing Things Out</h3></div></div></div><p> 390<a class="indexterm" name="id2654740"></a> 391<a class="indexterm" name="id2654747"></a> 392<a class="indexterm" name="id2654754"></a> 393<a class="indexterm" name="id2654760"></a> 394<a class="indexterm" name="id2654767"></a> 395Before starting, it is probably best to kill off all the Samba-related daemons running on your server. 396Kill off all <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> processes that may be running. To use PAM, 397make sure that you have the standard PAM package that supplies the <code class="filename">/etc/pam.d</code> 398directory structure, including the PAM modules that are used by PAM-aware services, several PAM libraries, 399and the <code class="filename">/usr/doc</code> and <code class="filename">/usr/man</code> entries for PAM. Winbind is built 400better in Samba if the pam-devel package is also installed. This package includes the header files 401needed to compile PAM-aware applications. 402</p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2654819"></a>Configure <code class="filename">nsswitch.conf</code> and the Winbind Libraries on Linux and Solaris</h4></div></div></div><p> 403<a class="indexterm" name="id2654834"></a> 404<a class="indexterm" name="id2654840"></a> 405<a class="indexterm" name="id2654847"></a> 406<a class="indexterm" name="id2654854"></a> 407PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install 408the <code class="filename">pam-devel</code> libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3 409may auto-install the Winbind files into their correct locations on your system, so before you get too far down 410the track, be sure to check if the following configuration is really 411necessary. You may only need to configure 412<code class="filename">/etc/nsswitch.conf</code>. 413</p><p> 414The libraries needed to run the <span class="application">winbindd</span> daemon through nsswitch need to be copied to their proper locations: 415</p><p> 416<a class="indexterm" name="id2654893"></a> 417</p><pre class="screen"> 418<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/libnss_winbind.so /lib</code></strong> 419</pre><p> 420</p><p> 421I also found it necessary to make the following symbolic link: 422</p><p> 423<code class="prompt">root# </code> <strong class="userinput"><code>ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2</code></strong> 424</p><p>And, in the case of Sun Solaris: 425<a class="indexterm" name="id2654941"></a> 426</p><pre class="screen"> 427<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1</code></strong> 428<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1</code></strong> 429<code class="prompt">root# </code><strong class="userinput"><code>ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2</code></strong> 430</pre><p> 431</p><p> 432<a class="indexterm" name="id2654990"></a> 433As root, edit <code class="filename">/etc/nsswitch.conf</code> to allow user and group entries to be visible from the 434<span class="application">winbindd</span> daemon. My <code class="filename">/etc/nsswitch.conf</code> file looked like this after editing: 435</p><pre class="programlisting"> 436passwd: files winbind 437shadow: files 438group: files winbind 439</pre><p> 440<a class="indexterm" name="id2655026"></a> 441<a class="indexterm" name="id2655033"></a> 442<a class="indexterm" name="id2655040"></a> 443<a class="indexterm" name="id2655047"></a> 444<a class="indexterm" name="id2655054"></a> 445The libraries needed by the <code class="literal">winbindd</code> daemon will be automatically 446entered into the <code class="literal">ldconfig</code> cache the next time 447your system reboots, but it is faster (and you do not need to reboot) if you do it manually: 448</p><pre class="screen"> 449<code class="prompt">root# </code><strong class="userinput"><code>/sbin/ldconfig -v | grep winbind</code></strong> 450</pre><p> 451This makes <code class="filename">libnss_winbind</code> available to winbindd and reports the current 452search path that is used by the dynamic link loader. The use of the <code class="literal">grep</code> 453filters the output of the <code class="literal">ldconfig</code> command so that we may see proof that 454this library is indeed recognized by the dynamic link loader. 455</p><p> 456<a class="indexterm" name="id2655117"></a> 457<a class="indexterm" name="id2655124"></a> 458<a class="indexterm" name="id2655131"></a> 459<a class="indexterm" name="id2655138"></a> 460<a class="indexterm" name="id2655145"></a> 461The Sun Solaris dynamic link loader management tool is called <code class="literal">crle</code>. The 462use of this tool is necessary to instruct the dynamic link loader to search directories that 463contain library files that were not supplied as part of the original operating system platform. 464The following example shows how to use this tool to add the directory <code class="filename">/usr/local/lib</code> 465to the dynamic link loader's search path: 466</p><pre class="screen"> 467<code class="prompt">root# </code> crle -u -l /usr/lib:/usr/local/lib 468</pre><p> 469When executed without arguments, <code class="literal">crle</code> reports the current dynamic 470link loader configuration. This is demonstrated here: 471</p><pre class="screen"> 472<code class="prompt">root# </code> crle 473 474Configuration file [version 4]: /var/ld/ld.config 475 Default Library Path (ELF): /lib:/usr/lib:/usr/local/lib 476 Trusted Directories (ELF): /lib/secure:/usr/lib/secure (system default) 477 478Command line: 479 crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/local/lib 480</pre><p> 481From this it is apparent that the <code class="filename">/usr/local/lib</code> directory is included 482in the search dynamic link libraries in order to satisfy object module dependencies. 483</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2655217"></a>NSS Winbind on AIX</h4></div></div></div><p>(This section is only for those running AIX.)</p><p> 484<a class="indexterm" name="id2655229"></a> 485<a class="indexterm" name="id2655236"></a> 486<a class="indexterm" name="id2655242"></a> 487<a class="indexterm" name="id2655249"></a> 488<a class="indexterm" name="id2655256"></a> 489<a class="indexterm" name="id2655264"></a> 490The Winbind AIX identification module gets built as <code class="filename">libnss_winbind.so</code> in the 491nsswitch directory of the Samba source. This file can be copied to <code class="filename">/usr/lib/security</code>, 492and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following: 493</p><pre class="programlisting"> 494WINBIND: 495 program = /usr/lib/security/WINBIND 496 options = authonly 497</pre><p> 498can then be added to <code class="filename">/usr/lib/security/methods.cfg</code>. This module only supports 499identification, but there have been reports of success using the standard Winbind PAM module for 500authentication. Use caution configuring loadable authentication modules, since misconfiguration can make 501it impossible to log on to the system. Information regarding the AIX authentication module API can 502be found in the “<span class="quote">Kernel Extensions and Device Support Programming Concepts for AIX</span>” document that 503describes the <a class="ulink" href="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixprggd/kernextc/sec_load_mod.htm" target="_top"> 504Loadable Authentication Module Programming Interface</a> for AIX. Further information on administering the modules 505can be found in the <a class="ulink" href="http://publibn.boulder.ibm.com/doc_link/en_US/a_doc_lib/aixbman/baseadmn/iandaadmin.htm" target="_top">System 506Management Guide: Operating System and Devices.</a> 507</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2655330"></a>Configure smb.conf</h4></div></div></div><p> 508<a class="indexterm" name="id2655338"></a> 509<a class="indexterm" name="id2655345"></a> 510<a class="indexterm" name="id2655352"></a> 511Several parameters are needed in the <code class="filename">smb.conf</code> file to control the behavior of <span class="application">winbindd</span>. These 512are described in more detail in the <a class="citerefentry" href="winbindd.8.html"><span class="citerefentry"><span class="refentrytitle">winbindd</span>(8)</span></a> man page. My <code class="filename">smb.conf</code> file, as shown in <a class="link" href="winbind.html#winbindcfg" title="Example�24.1.�smb.conf for Winbind Setup">the smb.conf for Winbind Setup</a>, was modified to include the necessary entries in the [global] section. 513</p><div class="example"><a name="winbindcfg"></a><p class="title"><b>Example�24.1.�smb.conf for Winbind Setup</b></p><div class="example-contents"><table 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="id2655425"></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="id2655441"></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="id2655457"></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="id2655473"></a><em class="parameter"><code>winbind enum users = yes</code></em></td></tr><tr><td><a class="indexterm" name="id2655485"></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="id2655501"></a><em class="parameter"><code>template homedir = /home/winnt/%D/%U</code></em></td></tr><tr><td><a class="indexterm" name="id2655514"></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="id2655528"></a>Join the Samba Server to the PDC Domain</h4></div></div></div><p> 514<a class="indexterm" name="id2655536"></a> 515<a class="indexterm" name="id2655543"></a> 516<a class="indexterm" name="id2655549"></a> 517All machines that will participate in domain security should be members of 518the domain. This applies also to the PDC and all BDCs. 519</p><p> 520<a class="indexterm" name="id2655561"></a> 521<a class="indexterm" name="id2655568"></a> 522<a class="indexterm" name="id2655575"></a> 523<a class="indexterm" name="id2655586"></a> 524<a class="indexterm" name="id2655593"></a> 525<a class="indexterm" name="id2655599"></a> 526<a class="indexterm" name="id2655606"></a> 527<a class="indexterm" name="id2655613"></a> 528<a class="indexterm" name="id2655620"></a> 529The process of joining a domain requires the use of the <code class="literal">net rpc join</code> 530command. This process communicates with the domain controller it will register with 531(usually the PDC) via MS DCE RPC. This means, of course, that the <code class="literal">smbd</code> 532process must be running on the target domain controller. It is therefore necessary to temporarily 533start Samba on a PDC so that it can join its own domain. 534</p><p> 535<a class="indexterm" name="id2655648"></a> 536<a class="indexterm" name="id2655654"></a> 537<a class="indexterm" name="id2655661"></a> 538Enter the following command to make the Samba server join the domain, where <em class="replaceable"><code>PDC</code></em> is 539the name of your PDC and <em class="replaceable"><code>Administrator</code></em> is a domain user who has administrative 540privileges in the domain. 541</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> 542<a class="indexterm" name="id2655683"></a> 543<a class="indexterm" name="id2655690"></a> 544<a class="indexterm" name="id2655696"></a> 545<a class="indexterm" name="id2655703"></a> 546Before attempting to join a machine to the domain, verify that Samba is running 547on the target domain controller (usually PDC) and that it is capable of being reached via ports 548137/udp, 135/tcp, 139/tcp, and 445/tcp (if Samba or Windows Server 2Kx). 549</p></div><p> 550<a class="indexterm" name="id2655717"></a> 551The use of the <code class="literal">net rpc join</code> facility is shown here: 552</p><pre class="screen"> 553<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/net rpc join -S PDC -U Administrator</code></strong> 554</pre><p> 555The proper response to the command should be “<span class="quote">Joined the domain 556<em class="replaceable"><code>DOMAIN</code></em></span>” where <em class="replaceable"><code>DOMAIN</code></em> 557is your domain name. 558</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2655765"></a>Starting and Testing the <code class="literal">winbindd</code> Daemon</h4></div></div></div><p> 559<a class="indexterm" name="id2655779"></a> 560<a class="indexterm" name="id2655786"></a> 561<a class="indexterm" name="id2655793"></a> 562Eventually, you will want to modify your Samba startup script to automatically invoke the winbindd daemon when 563the other parts of Samba start, but it is possible to test out just the Winbind portion first. To start up 564Winbind services, enter the following command as root: 565</p><pre class="screen"> 566<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/sbin/winbindd</code></strong> 567</pre><p> 568Use the appropriate path to the location of the <code class="literal">winbindd</code> executable file. 569</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> 570<a class="indexterm" name="id2655832"></a> 571<a class="indexterm" name="id2655839"></a> 572The command to start up Winbind services assumes that Samba has been installed in the 573<code class="filename">/usr/local/samba</code> directory tree. You may need to search for the location of Samba files 574if this is not the location of <code class="literal">winbindd</code> on your system. 575</p></div><p> 576<a class="indexterm" name="id2655865"></a> 577<a class="indexterm" name="id2655872"></a> 578I'm always paranoid and like to make sure the daemon is really running. 579</p><pre class="screen"> 580<code class="prompt">root# </code><strong class="userinput"><code>ps -ae | grep winbindd</code></strong> 581</pre><p> 582</p><p> 583<a class="indexterm" name="id2655899"></a> 584This command should produce output like the following if the daemon is running. 585</p><pre class="screen"> 5863025 ? 00:00:00 winbindd 587</pre><p> 588</p><p> 589<a class="indexterm" name="id2655917"></a> 590<a class="indexterm" name="id2655924"></a> 591Now, for the real test, try to get some information about the users on your PDC: 592</p><pre class="screen"> 593<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -u</code></strong> 594</pre><p> 595This should echo back a list of users on your Windows users on your PDC. For example, I get the following 596response: 597</p><pre class="screen"> 598CEO\Administrator 599CEO\burdell 600CEO\Guest 601CEO\jt-ad 602CEO\krbtgt 603CEO\TsInternetUser 604</pre><p> 605Obviously, I have named my domain “<span class="quote">CEO</span>” and my <a class="link" href="smb.conf.5.html#WINBINDSEPARATOR" target="_top">winbind separator</a> is 606“<span class="quote">\</span>”. 607</p><p> 608<a class="indexterm" name="id2655982"></a> 609<a class="indexterm" name="id2655988"></a> 610You can do the same sort of thing to get group information from the PDC: 611</p><pre class="screen"> 612<code class="prompt">root# </code><strong class="userinput"><code>/usr/local/samba/bin/wbinfo -g</code></strong> 613CEO\Domain Admins 614CEO\Domain Users 615CEO\Domain Guests 616CEO\Domain Computers 617CEO\Domain Controllers 618CEO\Cert Publishers 619CEO\Schema Admins 620CEO\Enterprise Admins 621CEO\Group Policy Creator Owners 622</pre><p> 623<a class="indexterm" name="id2656018"></a> 624<a class="indexterm" name="id2656025"></a> 625<a class="indexterm" name="id2656032"></a> 626<a class="indexterm" name="id2656038"></a> 627<a class="indexterm" name="id2656045"></a> 628<a class="indexterm" name="id2656051"></a> 629<a class="indexterm" name="id2656058"></a> 630The function <code class="literal">getent</code> can now be used to get unified lists of both local and PDC users and 631groups. Try the following command: 632</p><pre class="screen"> 633<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong> 634</pre><p> 635You should get a list that looks like your <code class="filename">/etc/passwd</code> 636list followed by the domain users with their new UIDs, GIDs, home 637directories, and default shells. 638</p><p> 639The same thing can be done for groups with the command: 640</p><pre class="screen"> 641<code class="prompt">root# </code><strong class="userinput"><code>getent group</code></strong> 642</pre><p> 643</p></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2656120"></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="id2656126"></a>Linux</h5></div></div></div><p> 644<a class="indexterm" name="id2656134"></a> 645<a class="indexterm" name="id2656141"></a> 646<a class="indexterm" name="id2656148"></a> 647<a class="indexterm" name="id2656155"></a> 648<a class="indexterm" name="id2656162"></a> 649<a class="indexterm" name="id2656169"></a> 650<a class="indexterm" name="id2656176"></a> 651<a class="indexterm" name="id2656181"></a> 652<a class="indexterm" name="id2656187"></a> 653The <span class="application">winbindd</span> daemon needs to start up after the <span class="application">smbd</span> and <span class="application">nmbd</span> daemons are running. To accomplish this 654task, you need to modify the startup scripts of your system. They are located at 655<code class="filename">/etc/init.d/smb</code> in Red Hat Linux and in <code class="filename">/etc/init.d/samba</code> in Debian 656Linux. Edit your script to add commands to invoke this daemon in the proper sequence. My startup script starts 657up <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> from the <code class="filename">/usr/local/samba/bin</code> directory directly. The 658<code class="literal">start</code> function in the script looks like this: 659</p><pre class="programlisting"> 660start() { 661 KIND="SMB" 662 echo -n $"Starting $KIND services: " 663 daemon /usr/local/samba/bin/smbd $SMBDOPTIONS 664 RETVAL=$? 665 echo 666 KIND="NMB" 667 echo -n $"Starting $KIND services: " 668 daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS 669 RETVAL2=$? 670 echo 671 KIND="Winbind" 672 echo -n $"Starting $KIND services: " 673 daemon /usr/local/samba/sbin/winbindd 674 RETVAL3=$? 675 echo 676 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \ 677 touch /var/lock/subsys/smb || RETVAL=1 678 return $RETVAL 679} 680</pre><p>If you would like to run winbindd in dual daemon mode, replace the line: 681</p><pre class="programlisting"> 682 daemon /usr/local/samba/sbin/winbindd 683</pre><p> 684 685in the example above with: 686 687</p><pre class="programlisting"> 688 daemon /usr/local/samba/sbin/winbindd -D 689</pre><p>. 690</p><p> 691The <code class="literal">stop</code> function has a corresponding entry to shut down the services and looks like this: 692</p><pre class="programlisting"> 693stop() { 694 KIND="SMB" 695 echo -n $"Shutting down $KIND services: " 696 killproc smbd 697 RETVAL=$? 698 echo 699 KIND="NMB" 700 echo -n $"Shutting down $KIND services: " 701 killproc nmbd 702 RETVAL2=$? 703 echo 704 KIND="Winbind" 705 echo -n $"Shutting down $KIND services: " 706 killproc winbindd 707 RETVAL3=$? 708 [ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \ 709 rm -f /var/lock/subsys/smb 710 echo "" 711 return $RETVAL 712} 713</pre></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2656332"></a>Solaris</h5></div></div></div><p> 714Winbind does not work on Solaris 9; see <a class="link" href="Portability.html#winbind-solaris9" title="Winbind on Solaris 9">Winbind on Solaris 9 section</a> 715for details. 716</p><p> 717<a class="indexterm" name="id2656353"></a> 718<a class="indexterm" name="id2656360"></a> 719<a class="indexterm" name="id2656367"></a> 720<a class="indexterm" name="id2656374"></a> 721<a class="indexterm" name="id2656380"></a> 722<a class="indexterm" name="id2656387"></a> 723On Solaris, you need to modify the <code class="filename">/etc/init.d/samba.server</code> startup script. It 724usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in 725<code class="filename">/usr/local/samba/bin</code>, the file could contains something like this: 726</p><p> 727 </p><pre class="programlisting"> 728 ## 729 ## samba.server 730 ## 731 732 if [ ! -d /usr/bin ] 733 then # /usr not mounted 734 exit 735 fi 736 737 killproc() { # kill the named process(es) 738 pid=`/usr/bin/ps -e | 739 /usr/bin/grep -w $1 | 740 /usr/bin/sed -e 's/^ *//' -e 's/ .*//'` 741 [ "$pid" != "" ] && kill $pid 742 } 743 744 # Start/stop processes required for Samba server 745 746 case "$1" in 747 748 'start') 749 # 750 # Edit these lines to suit your installation (paths, workgroup, host) 751 # 752 echo Starting SMBD 753 /usr/local/samba/bin/smbd -D -s \ 754 /usr/local/samba/smb.conf 755 756 echo Starting NMBD 757 /usr/local/samba/bin/nmbd -D -l \ 758 /usr/local/samba/var/log -s /usr/local/samba/smb.conf 759 760 echo Starting Winbind Daemon 761 /usr/local/samba/sbin/winbindd 762 ;; 763 764 'stop') 765 killproc nmbd 766 killproc smbd 767 killproc winbindd 768 ;; 769 770 *) 771 echo "Usage: /etc/init.d/samba.server { start | stop }" 772 ;; 773 esac 774</pre><p> 775Again, if you would like to run Samba in dual daemon mode, replace: 776</p><pre class="programlisting"> 777/usr/local/samba/sbin/winbindd 778</pre><p> 779in the script above with: 780</p><pre class="programlisting"> 781/usr/local/samba/sbin/winbindd -D 782</pre><p> 783</p></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2656476"></a>Restarting</h5></div></div></div><p> 784<a class="indexterm" name="id2656484"></a> 785<a class="indexterm" name="id2656491"></a> 786If you restart the <span class="application">smbd</span>, <span class="application">nmbd</span>, and <span class="application">winbindd</span> daemons at this point, you 787should be able to connect to the Samba server as a domain member just as 788if you were a local user. 789</p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2656521"></a>Configure Winbind and PAM</h4></div></div></div><p> 790<a class="indexterm" name="id2656529"></a> 791<a class="indexterm" name="id2656536"></a> 792<a class="indexterm" name="id2656543"></a> 793<a class="indexterm" name="id2656549"></a> 794If you have made it this far, you know that <code class="literal">winbindd</code> and Samba are working together. If you 795want to use Winbind to provide authentication for other services, keep reading. The PAM configuration files 796need to be altered in this step. (Did you remember to make backups of your original 797<code class="filename">/etc/pam.d</code> files? If not, do it now.) 798</p><p> 799<a class="indexterm" name="id2656576"></a> 800<a class="indexterm" name="id2656583"></a> 801<a class="indexterm" name="id2656590"></a> 802<a class="indexterm" name="id2656597"></a> 803<a class="indexterm" name="id2656604"></a> 804<a class="indexterm" name="id2656610"></a> 805You will need a PAM module to use winbindd with these other services. This module will be compiled in the 806<code class="filename">../source/nsswitch</code> directory by invoking the command: 807</p><pre class="screen"> 808<code class="prompt">root# </code><strong class="userinput"><code>make nsswitch/pam_winbind.so</code></strong> 809</pre><p> 810from the <code class="filename">../source</code> directory. The <code class="filename">pam_winbind.so</code> file should be 811copied to the location of your other PAM security modules. On my Red Hat system, this was the 812<code class="filename">/lib/security</code> directory. On Solaris, the PAM security modules reside in 813<code class="filename">/usr/lib/security</code>. 814</p><pre class="screen"> 815<code class="prompt">root# </code><strong class="userinput"><code>cp ../samba/source/nsswitch/pam_winbind.so /lib/security</code></strong> 816</pre><p> 817</p><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2656687"></a>Linux/FreeBSD-Specific PAM Configuration</h5></div></div></div><p> 818<a class="indexterm" name="id2656695"></a> 819The <code class="filename">/etc/pam.d/samba</code> file does not need to be changed. I just left this file as it was: 820</p><pre class="programlisting"> 821auth required /lib/security/pam_stack.so service=system-auth 822account required /lib/security/pam_stack.so service=system-auth 823</pre><p> 824<a class="indexterm" name="id2656720"></a> 825<a class="indexterm" name="id2656727"></a> 826<a class="indexterm" name="id2656734"></a> 827<a class="indexterm" name="id2656740"></a> 828<a class="indexterm" name="id2656747"></a> 829<a class="indexterm" name="id2656754"></a> 830<a class="indexterm" name="id2656761"></a> 831<a class="indexterm" name="id2656768"></a> 832<a class="indexterm" name="id2656775"></a> 833The other services that I modified to allow the use of Winbind as an authentication service were the normal 834login on the console (or a terminal session), telnet logins, and ftp service. In order to enable these 835services, you may first need to change the entries in <code class="filename">/etc/xinetd.d</code> (or 836<code class="filename">/etc/inetd.conf</code>). Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this 837case you need to change the lines in <code class="filename">/etc/xinetd.d/telnet</code> and 838<code class="filename">/etc/xinetd.d/wu-ftp</code> from: 839</p><pre class="programlisting"> 840 enable = no 841</pre><p> 842to 843</p><pre class="programlisting"> 844 enable = yes 845</pre><p> 846<a class="indexterm" name="id2656827"></a> 847<a class="indexterm" name="id2656834"></a> 848<a class="indexterm" name="id2656841"></a> 849For ftp services to work properly, you will also need to either have individual directories for the domain 850users already present on the server or change the home directory template to a general directory for all 851domain users. These can be easily set using the <code class="filename">smb.conf</code> global entry <a class="link" href="smb.conf.5.html#TEMPLATEHOMEDIR" target="_top">template homedir</a>. 852</p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p> 853<a class="indexterm" name="id2656877"></a> 854The directory in <a class="link" href="smb.conf.5.html#TEMPLATEHOMEDIR" target="_top">template homedir</a> is not created automatically! Use pam_mkhomedir or 855pre-create the directories of users to make sure users can log in on UNIX with their own home directory. 856</p></div><p> 857<a class="indexterm" name="id2656902"></a> 858<a class="indexterm" name="id2656908"></a> 859<a class="indexterm" name="id2656915"></a> 860The <code class="filename">/etc/pam.d/ftp</code> file can be changed to allow Winbind ftp access in a manner similar to 861the samba file. My <code class="filename">/etc/pam.d/ftp</code> file was changed to look like this: 862</p><pre class="programlisting"> 863auth required /lib/security/pam_listfile.so item=user sense=deny \ 864 file=/etc/ftpusers onerr=succeed 865auth sufficient /lib/security/pam_winbind.so 866auth required /lib/security/pam_stack.so service=system-auth 867auth required /lib/security/pam_shells.so 868account sufficient /lib/security/pam_winbind.so 869account required /lib/security/pam_stack.so service=system-auth 870session required /lib/security/pam_stack.so service=system-auth 871</pre><p> 872<a class="indexterm" name="id2656951"></a> 873The <code class="filename">/etc/pam.d/login</code> file can be changed in nearly the same way. It now looks like this: 874</p><pre class="programlisting"> 875auth required /lib/security/pam_securetty.so 876auth sufficient /lib/security/pam_winbind.so 877auth sufficient /lib/security/pam_unix.so use_first_pass 878auth required /lib/security/pam_stack.so service=system-auth 879auth required /lib/security/pam_nologin.so 880account sufficient /lib/security/pam_winbind.so 881account required /lib/security/pam_stack.so service=system-auth 882password required /lib/security/pam_stack.so service=system-auth 883session required /lib/security/pam_stack.so service=system-auth 884session optional /lib/security/pam_console.so 885</pre><p> 886<a class="indexterm" name="id2656982"></a> 887<a class="indexterm" name="id2656989"></a> 888<a class="indexterm" name="id2656996"></a> 889In this case, I added the </p><pre class="programlisting">auth sufficient /lib/security/pam_winbind.so</pre><p> lines 890as before, but also added the </p><pre class="programlisting">required pam_securetty.so</pre><p> above it to disallow 891root logins over the network. I also added a </p><pre class="programlisting">sufficient /lib/security/pam_unix.so 892use_first_pass</pre><p> line after the <code class="literal">winbind.so</code> line to get rid of annoying 893double prompts for passwords. 894</p></div><div class="sect4" lang="en"><div class="titlepage"><div><div><h5 class="title"><a name="id2657034"></a>Solaris-Specific Configuration</h5></div></div></div><p> 895<a class="indexterm" name="id2657042"></a> 896<a class="indexterm" name="id2657049"></a> 897The <code class="filename">/etc/pam.conf</code> needs to be changed. I changed this file so my Domain 898users can log on both locally as well as with telnet. The following are the changes 899that I made. You can customize the <code class="filename">pam.conf</code> file as per your requirements, but 900be sure of those changes because in the worst case it will leave your system 901nearly impossible to boot. 902</p><pre class="programlisting"> 903# 904#ident "@(#)pam.conf 1.14 99/09/16 SMI" 905# 906# Copyright (c) 1996-1999, Sun Microsystems, Inc. 907# All Rights Reserved. 908# 909# PAM configuration 910# 911# Authentication management 912# 913login auth required /usr/lib/security/pam_winbind.so 914login auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass 915login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass 916# 917rlogin auth sufficient /usr/lib/security/pam_winbind.so 918rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1 919rlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass 920# 921dtlogin auth sufficient /usr/lib/security/pam_winbind.so 922dtlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass 923# 924rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1 925other auth sufficient /usr/lib/security/pam_winbind.so 926other auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass 927# 928# Account management 929# 930login account sufficient /usr/lib/security/pam_winbind.so 931login account requisite /usr/lib/security/$ISA/pam_roles.so.1 932login account required /usr/lib/security/$ISA/pam_unix.so.1 933# 934dtlogin account sufficient /usr/lib/security/pam_winbind.so 935dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1 936dtlogin account required /usr/lib/security/$ISA/pam_unix.so.1 937# 938other account sufficient /usr/lib/security/pam_winbind.so 939other account requisite /usr/lib/security/$ISA/pam_roles.so.1 940other account required /usr/lib/security/$ISA/pam_unix.so.1 941# 942# Session management 943# 944other session required /usr/lib/security/$ISA/pam_unix.so.1 945# 946# Password management 947# 948#other password sufficient /usr/lib/security/pam_winbind.so 949other password required /usr/lib/security/$ISA/pam_unix.so.1 950dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1 951# 952# Support for Kerberos V5 authentication (uncomment to use Kerberos) 953# 954#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass 955#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass 956#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass 957#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass 958#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1 959#other account optional /usr/lib/security/$ISA/pam_krb5.so.1 960#other session optional /usr/lib/security/$ISA/pam_krb5.so.1 961#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass 962</pre><p> 963<a class="indexterm" name="id2657120"></a> 964I also added a <em class="parameter"><code>try_first_pass</code></em> line after the <code class="filename">winbind.so</code> 965line to get rid of annoying double prompts for passwords. 966</p><p> 967Now restart your Samba and try connecting through your application that you 968configured in the pam.conf. 969</p></div></div></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2657151"></a>Conclusion</h2></div></div></div><p> 970<a class="indexterm" name="id2657158"></a> 971<a class="indexterm" name="id2657165"></a> 972<a class="indexterm" name="id2657172"></a> 973<a class="indexterm" name="id2657178"></a> 974<a class="indexterm" name="id2657185"></a> 975The Winbind system, through the use of the NSS, PAMs, and appropriate Microsoft RPC calls, have allowed us to 976provide seamless integration of Microsoft Windows NT domain users on a UNIX system. The result is a great 977reduction in the administrative cost of running a mixed UNIX and NT network. 978</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2657199"></a>Common Errors</h2></div></div></div><p> 979 Winbind has a number of limitations in its current released version that we hope to overcome in future releases: 980 </p><div class="itemizedlist"><ul type="disc"><li><p> 981 Winbind is currently only available for the Linux, Solaris, AIX, and IRIX operating systems, although 982 ports to other operating systems are certainly possible. For such ports to be feasible, we require the C 983 library of the target operating system to support the NSS and PAM systems. This is becoming more common as NSS 984 and PAM gain support among UNIX vendors. 985 </p></li><li><p> 986 The mappings of Windows NT RIDs to UNIX IDs is not made algorithmically and depends on the order in 987 which unmapped users or groups are seen by Winbind. It may be difficult to recover the mappings of RID to UNIX 988 ID if the file containing this information is corrupted or destroyed. 989 </p></li><li><p> 990 Currently the Winbind PAM module does not take into account possible workstation and logon time 991 restrictions that may be set for Windows NT users; this is instead up to the PDC to enforce. 992 </p></li></ul></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2657241"></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> 993 Do not under any circumstances run <code class="literal">nscd</code> on any system 994 on which <code class="literal">winbindd</code> is running. 995 </p></div><p> 996 If <code class="literal">nscd</code> is running on the UNIX/Linux system, then 997 even though NSSWITCH is correctly configured, it will not be possible to resolve 998 domain users and groups for file and directory controls. 999 </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2657278"></a>Winbind Is Not Resolving Users and Groups</h3></div></div></div><p>“<span class="quote"> 1000 My <code class="filename">smb.conf</code> file is correctly configured. I have specified <a class="link" href="smb.conf.5.html#IDMAPUID" target="_top">idmap uid = 12000</a>, 1001 and <a class="link" href="smb.conf.5.html#IDMAPGID" target="_top">idmap gid = 3000-3500</a> and <code class="literal">winbind</code> is running. 1002 When I do the following, it all works fine. 1003 </span>”</p><pre class="screen"> 1004<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -u</code></strong> 1005MIDEARTH\maryo 1006MIDEARTH\jackb 1007MIDEARTH\ameds 1008... 1009MIDEARTH\root 1010 1011<code class="prompt">root# </code><strong class="userinput"><code>wbinfo -g</code></strong> 1012MIDEARTH\Domain Users 1013MIDEARTH\Domain Admins 1014MIDEARTH\Domain Guests 1015... 1016MIDEARTH\Accounts 1017 1018<code class="prompt">root# </code><strong class="userinput"><code>getent passwd</code></strong> 1019root:x:0:0:root:/root:/bin/bash 1020bin:x:1:1:bin:/bin:/bin/bash 1021... 1022maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false 1023</pre><p>“<span class="quote"> 1024But the following command just fails: 1025</span>” 1026</p><pre class="screen"> 1027<code class="prompt">root# </code><strong class="userinput"><code>chown maryo a_file</code></strong> 1028chown: `maryo': invalid user 1029</pre><p> 1030“<span class="quote"> 1031This is driving me nuts! What can be wrong? 1032</span>”</p><p> 1033Same problem as the one above. 1034Your system is likely running <code class="literal">nscd</code>, the name service 1035caching daemon. Shut it down, do not restart it! You will find your problem resolved. 1036Alternately, fix the operation of nscd to resolve the problem. 1037</p></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="VFS.html">Prev</a>�</td><td width="20%" align="center"><a accesskey="u" href="optional.html">Up</a></td><td width="40%" align="right">�<a accesskey="n" href="AdvancedNetworkManagement.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter�23.�Stackable VFS modules�</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">�Chapter�25.�Advanced Network Management</td></tr></table></div></body></html> 1038
