TimPotterSamba Teamtpot@linuxcare.com.au
&author.tridge;
NaagMummanenigetnag@rediffmail.comNotes for SolarisJohnTrostelSNAPjtrostel@snapserver.com
&author.jelmer;
&author.jht;
June 15, 2005Winbind: Use of Domain AccountsFeatures and Benefitsholy grailheterogeneous computing
Integration of UNIX and Microsoft Windows NT through a unified logon has
been considered a holy grail in heterogeneous computing environments for
a long time.
interoperabilitydomain userdomain groupgroup ownership
There is one other facility without which UNIX and Microsoft Windows network
interoperability would suffer greatly. It is imperative that there be a
mechanism for sharing files across UNIX systems and to be able to assign
domain user and group ownerships with integrity.
Pluggable Authentication ModulesPAMwinbindNSSRPCwinbind is a component of the Samba suite of programs that
solves the unified logon problem. Winbind uses a UNIX implementation of Microsoft
RPC calls, Pluggable Authentication Modules (PAMs), and the name service switch (NSS) to
allow Windows NT domain users to appear and operate as UNIX users on a UNIX
machine. This chapter describes the Winbind system, the functionality
it provides, how it is configured, and how it works internally.
Winbind provides three separate functions:
ADSNT4 domain
Authentication of user credentials (via PAM). This makes it possible to
log onto a UNIX/Linux system using user and group accounts from a Windows
NT4 (including a Samba domain) or an Active Directory domain.
identity resolutionNSS
Identity resolution (via NSS). This is the default when winbind is not used.
UIDGIDSIDidmap uididmap gididmap backend
Winbind maintains a database called winbind_idmap.tdb in which it stores
mappings between UNIX UIDs, GIDs, and NT SIDs. This mapping is used only
for users and groups that do not have a local UID/GID. It stores the UID/GID
allocated from the idmap uid/gid range that it has mapped to the NT SID.
If idmap backend has been specified as ldap:ldap://hostname[:389],
then instead of using a local mapping, Winbind will obtain this information
from the LDAP database.
winbinddstarting sambawinbindd/etc/passwd/etc/groupsmbdNSS
If winbindd is not running, smbd (which calls winbindd) will fall back to
using purely local information from /etc/passwd and /etc/group and no dynamic
mapping will be used. On an operating system that has been enabled with the NSS,
the resolution of user and group information will be accomplished via NSS.
IntroductionIt is well known that UNIX and Microsoft Windows NT have
different models for representing user and group information and
use different technologies for implementing them. This fact has
made it difficult to integrate the two systems in a satisfactory
manner.synchronization problemspasswords
One common solution in use today has been to create
identically named user accounts on both the UNIX and Windows systems
and use the Samba suite of programs to provide file and print services
between the two. This solution is far from perfect, however, because
adding and deleting users on both sets of machines becomes a chore,
and two sets of passwords are required &smbmdash; both of which
can lead to synchronization problems between the UNIX and Windows
systems and confusion for users.We divide the unified logon problem for UNIX machines into
three smaller problems:Obtaining Windows NT user and group information.
Authenticating Windows NT users.
Password changing for Windows NT users.
unified logonduplication of information
Ideally, a prospective solution to the unified logon problem
would satisfy all the above components without duplication of
information on the UNIX machines and without creating additional
tasks for the system administrator when maintaining users and
groups on either system. The Winbind system provides a simple
and elegant solution to all three components of the unified logon
problem.What Winbind ProvidesWindows account managementUNIX usersUNIX groupsNT domain
Winbind unifies UNIX and Windows NT account management by
allowing a UNIX box to become a full member of an NT domain. Once
this is done, the UNIX box will see NT users and groups as if
they were native UNIX users and groups, allowing the NT domain
to be used in much the same manner that NIS+ is used within
UNIX-only environments.Winbind hooksdomain controllerNSSredirection
The end result is that whenever a
program on the UNIX machine asks the operating system to look up
a user or group name, the query will be resolved by asking the
NT domain controller for the specified domain to do the lookup.
Because Winbind hooks into the operating system at a low level
(via the NSS name resolution modules in the C library), this
redirection to the NT domain controller is completely
transparent.user and groupdomain user
Users on the UNIX machine can then use NT user and group
names as they would native UNIX names. They can chown files
so they are owned by NT domain users or even login to the
UNIX machine and run a UNIX X Window session as a domain user.domain controller
The only obvious indication that Winbind is being used is
that user and group names take the form DOMAIN\user and
DOMAIN\group. This is necessary because it allows Winbind to determine
that redirection to a domain controller is wanted for a particular
lookup and which trusted domain is being referenced.PAM-enableddomain controller
Additionally, Winbind provides an authentication service that hooks into the PAM system
to provide authentication via an NT domain to any PAM-enabled
applications. This capability solves the problem of synchronizing
passwords between systems, since all passwords are stored in a single
location (on the domain controller).Target Usesinfrastructure
Winbind is targeted at organizations that have an
existing NT-based domain infrastructure into which they wish
to put UNIX workstations or servers. Winbind will allow these
organizations to deploy UNIX workstations without having to
maintain a separate account infrastructure. This greatly
simplifies the administrative overhead of deploying UNIX
workstations into an NT-based organization.AppliancesWinbind
Another interesting way in which we expect Winbind to
be used is as a central part of UNIX-based appliances. Appliances
that provide file and print services to Microsoft-based networks
will be able to use Winbind to provide seamless integration of
the appliance into the domain.Handling of Foreign SIDsforeign SID
The term foreign SID is often met with the reaction that it
is not relevant to a particular environment. The following documents an interchange
that took place on the Samba mailing list. It is a good example of the confusion
often expressed regarding the use of winbind.
local domain
Fact: Winbind is needed to handle users who use workstations that are NOT part
of the local domain.
PDC
Response: Why? I've used Samba with workstations that are not part of my domains
lots of times without using winbind. I thought winbind was for using Samba as a member server
in a domain controlled by another Samba/Windows PDC.UIDGIDforeign user
If the Samba server will be accessed from a domain other than the local Samba domain, or
if there will be access from machines that are not local domain members, winbind will
permit the allocation of UIDs and GIDs from the assigned pool that will keep the identity
of the foreign user separate from users that are members of the Samba domain.
PDCdomain memberdomain non-memberSID
This means that winbind is eminently useful in cases where a single
Samba PDC on a local network is combined with both domain member and domain non-member workstations.
If winbind is not used, the user george on a Windows workstation that is not a domain
member will be able to access the files of a user called george in the account database
of the Samba server that is acting as a PDC. When winbind is used, the default condition
is that the local user george will be treated as the account DOMAIN\george and the
foreign (non-member of the domain) account will be treated as MACHINE\george because
each has a different SID.
How Winbind WorkswinbinddUNIX domain socketNSSPAM
The Winbind system is designed around a client/server
architecture. A long-running winbindd daemon
listens on a UNIX domain socket waiting for requests
to arrive. These requests are generated by the NSS and PAM
clients and are processed sequentially.The technologies used to implement Winbind are described
in detail below.Microsoft Remote Procedure CallsMicrosoft Remote Procedure CallMSRPCPDCremote managementuser authenticationprint spooling
Over the last few years, efforts have been underway by various Samba Team members to implement various aspects of
the Microsoft Remote Procedure Call (MSRPC) system. This system is used for most network-related operations
between Windows NT machines, including remote management, user authentication, and print spooling. Although
initially this work was done to aid the implementation of Primary Domain Controller (PDC) functionality in
Samba, it has also yielded a body of code that can be used for other purposes.
MSRPCenumerate domain usersenumerate domain groups
Winbind uses various MSRPC calls to enumerate domain users and groups and to obtain detailed information about
individual users or groups. Other MSRPC calls can be used to authenticate NT domain users and to change user
passwords. By directly querying a Windows PDC for user and group information, Winbind maps the NT account
information onto UNIX user and group names.
Microsoft Active Directory ServicesLDAPKerberosWinbindnative mode
Since late 2001, Samba has gained the ability to interact with Microsoft Windows 2000 using its native
mode protocols rather than the NT4 RPC services. Using LDAP and Kerberos, a domain member running
Winbind can enumerate users and groups in exactly the same way as a Windows 200x client would, and in so doing
provide a much more efficient and effective Winbind implementation.
Name Service SwitchNSSnetworked workstationNISDNS
The NSS is a feature that is present in many UNIX operating systems. It allows system
information such as hostnames, mail aliases, and user information
to be resolved from different sources. For example, a standalone
UNIX workstation may resolve system information from a series of
flat files stored on the local file system. A networked workstation
may first attempt to resolve system information from local files,
and then consult an NIS database for user information or a DNS server
for hostname information.NSSMSRPCtrusted domainlocal userslocal groups
The NSS application programming interface allows Winbind to present itself as a source of system
information when resolving UNIX usernames and groups. Winbind uses this interface and information obtained
from a Windows NT server using MSRPC calls to provide a new source of account enumeration. Using standard UNIX
library calls, you can enumerate the users and groups on a UNIX machine running Winbind and see all users and
groups in an NT domain plus any trusted domain as though they were local users and groups.
NSS/etc/nsswitch.confpasswd
The primary control file for NSS is /etc/nsswitch.conf. When a UNIX application
makes a request to do a lookup, the C library looks in /etc/nsswitch.conf for a line that
matches the service type being requested; for example, the passwd service type is used when
user or group names are looked up. This config line specifies which implementations of that service should be
tried and in what order. If the passwd config line is:
passwd: files example
/lib/libnss_files.so/lib/libnss_example.soresolver functions
then the C library will first load a module called /lib/libnss_files.so followed
by the module /lib/libnss_example.so. The C library will dynamically load each of these
modules in turn and call resolver functions within the modules to try to resolve the request. Once the request
is resolved, the C library returns the result to the application.
NSSlibnss_winbind.so/etc/nsswitch.conf
This NSS interface provides an easy way for Winbind to hook into the operating system. All that needs
to be done is to put libnss_winbind.so in /lib/ then add
winbind into /etc/nsswitch.conf at the appropriate place. The C library
will then call Winbind to resolve user and group names.
Pluggable Authentication ModulesPAMauthentication methodsauthorizationNIS database
PAMs provide a system for abstracting authentication and authorization technologies. With a PAM
module, it is possible to specify different authentication methods for different system applications without
having to recompile these applications. PAM is also useful for implementing a particular policy for
authorization. For example, a system administrator may only allow console logins from users stored in the
local password file but only allow users resolved from an NIS database to log in over the network.
PAMWinbindauthentication managementpassword managementPDC
Winbind uses the authentication management and password management PAM interface to integrate Windows
NT users into a UNIX system. This allows Windows NT users to log in to a UNIX machine and be authenticated
against a suitable PDC. These users can also change their passwords and have this change take effect directly
on the PDC.
PAM/etc/pam.d/pam_winbind.so/lib/security/
PAM is configured by providing control files in the directory /etc/pam.d/ for
each of the services that require authentication. When an authentication request is made by an application,
the PAM code in the C library looks up this control file to determine what modules to load to do the
authentication check and in what order. This interface makes adding a new authentication service for Winbind
very easy: simply copy the pam_winbind.so module to /lib/security/,
and the PAM control files for relevant services are updated to allow authentication via Winbind. See the PAM
documentation in PAM-Based Distributed Authentication, for more information.
User and Group ID AllocationRIDWinbindUNIX ID
When a user or group is created under Windows NT/200x, it is allocated a numerical relative identifier
(RID). This is slightly different from UNIX, which has a range of numbers that are used to identify users and
the same range used to identify groups. It is Winbind's job to convert RIDs to UNIX ID numbers and vice versa.
When Winbind is configured, it is given part of the UNIX user ID space and a part of the UNIX group ID space
in which to store Windows NT users and groups. If a Windows NT user is resolved for the first time, it is
allocated the next UNIX ID from the range. The same process applies for Windows NT groups. Over time, Winbind
will have mapped all Windows NT users and groups to UNIX user IDs and group IDs.
ID mapping databasetdbUNIX IDRID
The results of this mapping are stored persistently in an ID mapping database held in a tdb database.
This ensures that RIDs are mapped to UNIX IDs in a consistent way.
Result CachingSAMcaching schemeWinbindADSPDC
An active directory system can generate a lot of user and group name lookups. To reduce the network
cost of these lookups, Winbind uses a caching scheme based on the SAM sequence number supplied by NT domain
controllers. User or group information returned by a PDC is cached by Winbind along with a sequence number
also returned by the PDC. This sequence number is incremented by Windows NT whenever any user or group
information is modified. If a cached entry has expired, the sequence number is requested from the PDC and
compared against the sequence number of the cached entry. If the sequence numbers do not match, then the
cached information is discarded and up-to-date information is requested directly from the PDC.
Installation and ConfigurationIntroductionWinbindPDCauthentication control
This section describes the procedures used to get Winbind up and running. Winbind is capable of providing
access and authentication control for Windows Domain users through an NT or Windows 200x PDC for regular
services, such as telnet and ftp, as well for Samba services.
Why should I do this?Samba administratorauthentication mechanismsdomain membersaccounts
This allows the Samba administrator to rely on the authentication mechanisms on the Windows NT/200x PDC
for the authentication of domain members. Windows NT/200x users no longer need to have separate accounts on
the Samba server.
Who should be reading this document?PDCWindows NT/200x
This document is designed for system administrators. If you are implementing Samba on a file server and wish
to (fairly easily) integrate existing Windows NT/200x users from your PDC onto the Samba server, this document
is for you.
RequirementsPAMback upboot disk
If you have a Samba configuration file that you are currently using, BACK IT UP!
If your system already uses PAM, back up the /etc/pam.d directory
contents! If you haven't already made a boot disk, MAKE ONE NOW!PAM configuration/etc/pam.dsingle-user mode
Messing with the PAM configuration files can make it nearly impossible to log in to your machine. That's
why you want to be able to boot back into your machine in single-user mode and restore your
/etc/pam.d to the original state it was in if you get frustrated with the
way things are going.
winbindddaemon
The latest version of Samba-3 includes a functioning winbindd daemon. Please refer to the main Samba Web page, or better yet, your closest Samba mirror site for
instructions on downloading the source code.
domain usersshares and filesPAMdevelopment libraries
To allow domain users the ability to access Samba shares and files, as well as potentially other services
provided by your Samba machine, PAM must be set up properly on your
machine. In order to compile the Winbind modules, the PAM development libraries should be installed
on your system. Please refer to the PAM Web site .
Testing Things Outsmbdnmbdwinbindd/etc/pam.dPAM
Before starting, it is probably best to kill off all the Samba-related daemons running on your server.
Kill off all &smbd;, &nmbd;, and &winbindd; processes that may be running. To use PAM,
make sure that you have the standard PAM package that supplies the /etc/pam.d
directory structure, including the PAM modules that are used by PAM-aware services, several PAM libraries,
and the /usr/doc and /usr/man entries for PAM. Winbind is built
better in Samba if the pam-devel package is also installed. This package includes the header files
needed to compile PAM-aware applications.
Configure nsswitch.conf and the Winbind Libraries on Linux and SolarisPAMpam-develWinbind/etc/nsswitch.conf
PAM is a standard component of most current generation UNIX/Linux systems. Unfortunately, few systems install
the pam-devel libraries that are needed to build PAM-enabled Samba. Additionally, Samba-3
may auto-install the Winbind files into their correct locations on your system, so before you get too far down
the track, be sure to check if the following configuration is really
necessary. You may only need to configure
/etc/nsswitch.conf.
The libraries needed to run the &winbindd; daemon through nsswitch need to be copied to their proper locations:
libnss_winbind.so
&rootprompt;cp ../samba/source/nsswitch/libnss_winbind.so /lib
I also found it necessary to make the following symbolic link:
&rootprompt; ln -s /lib/libnss_winbind.so /lib/libnss_winbind.so.2And, in the case of Sun Solaris:
nss_winbind.so.1
&rootprompt;ln -s /usr/lib/libnss_winbind.so /usr/lib/libnss_winbind.so.1
&rootprompt;ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.1
&rootprompt;ln -s /usr/lib/libnss_winbind.so /usr/lib/nss_winbind.so.2/etc/nsswitch.conf
As root, edit /etc/nsswitch.conf to allow user and group entries to be visible from the
&winbindd; daemon. My /etc/nsswitch.conf file looked like this after editing:
passwd: files winbind
shadow: files
group: files winbind
winbinddldconfiglibnss_winbindgrepdynamic link loader
The libraries needed by the winbindd daemon will be automatically
entered into the ldconfig cache the next time
your system reboots, but it is faster (and you do not need to reboot) if you do it manually:
&rootprompt;/sbin/ldconfig -v | grep winbind
This makes libnss_winbind available to winbindd and reports the current
search path that is used by the dynamic link loader. The use of the grep
filters the output of the ldconfig command so that we may see proof that
this library is indeed recognized by the dynamic link loader.
dynamic link loadercrle/usr/local/liblink loader configurationobject module dependencies
The Sun Solaris dynamic link loader management tool is called crle. The
use of this tool is necessary to instruct the dynamic link loader to search directories that
contain library files that were not supplied as part of the original operating system platform.
The following example shows how to use this tool to add the directory /usr/local/lib
to the dynamic link loader's search path:
&rootprompt; crle -u -l /usr/lib:/usr/local/lib
When executed without arguments, crle reports the current dynamic
link loader configuration. This is demonstrated here:
&rootprompt; crle
Configuration file [version 4]: /var/ld/ld.config
Default Library Path (ELF): /lib:/usr/lib:/usr/local/lib
Trusted Directories (ELF): /lib/secure:/usr/lib/secure (system default)
Command line:
crle -c /var/ld/ld.config -l /lib:/usr/lib:/usr/local/lib
From this it is apparent that the /usr/local/lib directory is included
in the search dynamic link libraries in order to satisfy object module dependencies.
NSS Winbind on AIX(This section is only for those running AIX.)AIXWinbind/usr/lib/securityauthentication module API/usr/lib/security/methods.cfgPAM module
The Winbind AIX identification module gets built as libnss_winbind.so in the
nsswitch directory of the Samba source. This file can be copied to /usr/lib/security,
and the AIX naming convention would indicate that it should be named WINBIND. A stanza like the following:
WINBIND:
program = /usr/lib/security/WINBIND
options = authonly
can then be added to /usr/lib/security/methods.cfg. This module only supports
identification, but there have been reports of success using the standard Winbind PAM module for
authentication. Use caution configuring loadable authentication modules, since misconfiguration can make
it impossible to log on to the system. Information regarding the AIX authentication module API can
be found in the Kernel Extensions and Device Support Programming Concepts for AIX document that
describes the
Loadable Authentication Module Programming Interface for AIX. Further information on administering the modules
can be found in the System
Management Guide: Operating System and Devices.Configure smb.confwinbindman pagewinbindd
Several parameters are needed in the &smb.conf; file to control the behavior of &winbindd;. These
are described in more detail in the winbindd8 man page. My &smb.conf; file, as shown in the smb.conf for Winbind Setup, was modified to include the necessary entries in the [global] section.
smb.conf for Winbind Setup separate domain and username with '\', like DOMAIN\username\ use uids from 10000 to 20000 for domain users10000-20000 use gids from 10000 to 20000 for domain groups10000-20000 allow enumeration of winbind users and groupsyesyes give winbind users a real shell (only needed if they have telnet access)/home/winnt/%D/%U/bin/bashJoin the Samba Server to the PDC Domaindomain securityPDCBDC
All machines that will participate in domain security should be members of
the domain. This applies also to the PDC and all BDCs.
joining domaindomain joinnetrpcjoinsmbdPDCdomain controllerMS DCE RPCDCE RPCRPC
The process of joining a domain requires the use of the net rpc join
command. This process communicates with the domain controller it will register with
(usually the PDC) via MS DCE RPC. This means, of course, that the smbd
process must be running on the target domain controller. It is therefore necessary to temporarily
start Samba on a PDC so that it can join its own domain.
PDCadministrative privilegesAdministrator
Enter the following command to make the Samba server join the domain, where PDC is
the name of your PDC and Administrator is a domain user who has administrative
privileges in the domain.
domain controllerPDCtcp portsudp ports
Before attempting to join a machine to the domain, verify that Samba is running
on the target domain controller (usually PDC) and that it is capable of being reached via ports
137/udp, 135/tcp, 139/tcp, and 445/tcp (if Samba or Windows Server 2Kx).
netrpcjoin
The use of the net rpc join facility is shown here:
&rootprompt;/usr/local/samba/bin/net rpc join -S PDC -U Administrator
The proper response to the command should be Joined the domain
DOMAIN where DOMAIN
is your domain name.
Starting and Testing the winbindd Daemonstartup scriptwinbinddWinbind services
Eventually, you will want to modify your Samba startup script to automatically invoke the winbindd daemon when
the other parts of Samba start, but it is possible to test out just the Winbind portion first. To start up
Winbind services, enter the following command as root:
&rootprompt;/usr/local/samba/sbin/winbindd
Use the appropriate path to the location of the winbindd executable file.
Winbind/usr/local/samba
The command to start up Winbind services assumes that Samba has been installed in the
/usr/local/samba directory tree. You may need to search for the location of Samba files
if this is not the location of winbindd on your system.
paranoiddaemon running
I'm always paranoid and like to make sure the daemon is really running.
&rootprompt;ps -ae | grep winbinddwinbindd
This command should produce output like the following if the daemon is running.
3025 ? 00:00:00 winbindd
PDCwbinfo
Now, for the real test, try to get some information about the users on your PDC:
&rootprompt;/usr/local/samba/bin/wbinfo -u
This should echo back a list of users on your Windows users on your PDC. For example, I get the following
response:
CEO\Administrator
CEO\burdell
CEO\Guest
CEO\jt-ad
CEO\krbtgt
CEO\TsInternetUser
Obviously, I have named my domain CEO and my is
\.
wbinfoPDC
You can do the same sort of thing to get group information from the PDC:
&rootprompt;/usr/local/samba/bin/wbinfo -g
CEO\Domain Admins
CEO\Domain Users
CEO\Domain Guests
CEO\Domain Computers
CEO\Domain Controllers
CEO\Cert Publishers
CEO\Schema Admins
CEO\Enterprise Admins
CEO\Group Policy Creator Owners
getentPDC/etc/passwdUIDGIDhome directoriesdefault shells
The function getent can now be used to get unified lists of both local and PDC users and
groups. Try the following command:
&rootprompt;getent passwd
You should get a list that looks like your /etc/passwd
list followed by the domain users with their new UIDs, GIDs, home
directories, and default shells.
The same thing can be done for groups with the command:
&rootprompt;getent groupFix the init.d Startup ScriptsLinuxwinbindd daemonsmbdnmbd/etc/init.d/smb/etc/init.d/samba/usr/local/samba/bin
The &winbindd; daemon needs to start up after the &smbd; and &nmbd; daemons are running. To accomplish this
task, you need to modify the startup scripts of your system. They are located at
/etc/init.d/smb in Red Hat Linux and in /etc/init.d/samba in Debian
Linux. Edit your script to add commands to invoke this daemon in the proper sequence. My startup script starts
up &smbd;, &nmbd;, and &winbindd; from the /usr/local/samba/bin directory directly. The
start function in the script looks like this:
start() {
KIND="SMB"
echo -n $"Starting $KIND services: "
daemon /usr/local/samba/bin/smbd $SMBDOPTIONS
RETVAL=$?
echo
KIND="NMB"
echo -n $"Starting $KIND services: "
daemon /usr/local/samba/bin/nmbd $NMBDOPTIONS
RETVAL2=$?
echo
KIND="Winbind"
echo -n $"Starting $KIND services: "
daemon /usr/local/samba/sbin/winbindd
RETVAL3=$?
echo
[ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \
touch /var/lock/subsys/smb || RETVAL=1
return $RETVAL
}
If you would like to run winbindd in dual daemon mode, replace the line:
daemon /usr/local/samba/sbin/winbindd
in the example above with:
daemon /usr/local/samba/sbin/winbindd -D
.
The stop function has a corresponding entry to shut down the services and looks like this:
stop() {
KIND="SMB"
echo -n $"Shutting down $KIND services: "
killproc smbd
RETVAL=$?
echo
KIND="NMB"
echo -n $"Shutting down $KIND services: "
killproc nmbd
RETVAL2=$?
echo
KIND="Winbind"
echo -n $"Shutting down $KIND services: "
killproc winbindd
RETVAL3=$?
[ $RETVAL -eq 0 -a $RETVAL2 -eq 0 -a $RETVAL3 -eq 0 ] && \
rm -f /var/lock/subsys/smb
echo ""
return $RETVAL
}
Solaris
Winbind does not work on Solaris 9; see Winbind on Solaris 9 section
for details.
Solaris 9/etc/init.d/samba.server/usr/local/samba/binsmbdnmbdwinbindd
On Solaris, you need to modify the /etc/init.d/samba.server startup script. It
usually only starts smbd and nmbd but should now start winbindd, too. If you have Samba installed in
/usr/local/samba/bin, the file could contains something like this:
##
## samba.server
##
if [ ! -d /usr/bin ]
then # /usr not mounted
exit
fi
killproc() { # kill the named process(es)
pid=`/usr/bin/ps -e |
/usr/bin/grep -w $1 |
/usr/bin/sed -e 's/^ *//' -e 's/ .*//'`
[ "$pid" != "" ] && kill $pid
}
# Start/stop processes required for Samba server
case "$1" in
'start')
#
# Edit these lines to suit your installation (paths, workgroup, host)
#
echo Starting SMBD
/usr/local/samba/bin/smbd -D -s \
/usr/local/samba/smb.conf
echo Starting NMBD
/usr/local/samba/bin/nmbd -D -l \
/usr/local/samba/var/log -s /usr/local/samba/smb.conf
echo Starting Winbind Daemon
/usr/local/samba/sbin/winbindd
;;
'stop')
killproc nmbd
killproc smbd
killproc winbindd
;;
*)
echo "Usage: /etc/init.d/samba.server { start | stop }"
;;
esac
Again, if you would like to run winbindd in dual daemon mode, replace:
/usr/local/samba/sbin/winbindd
in the script above with:
/usr/local/samba/sbin/winbindd -D
Restartingdaemonslocal user
If you restart the &smbd;, &nmbd;, and &winbindd; daemons at this point, you
should be able to connect to the Samba server as a domain member just as
if you were a local user.
Configure Winbind and PAMwinbinddauthenticationPAM/etc/pam.d
If you have made it this far, you know that winbindd and Samba are working together. If you
want to use Winbind to provide authentication for other services, keep reading. The PAM configuration files
need to be altered in this step. (Did you remember to make backups of your original
/etc/pam.d files? If not, do it now.)
NSS../source/nsswitchpam_winbind.so/lib/securitySolaris/usr/lib/security
You will need a PAM module to use winbindd with these other services. This module will be compiled in the
../source/nsswitch directory by invoking the command:
&rootprompt;make nsswitch/pam_winbind.so
from the ../source directory. The pam_winbind.so file should be
copied to the location of your other PAM security modules. On my Red Hat system, this was the
/lib/security directory. On Solaris, the PAM security modules reside in
/usr/lib/security.
&rootprompt;cp ../samba/source/nsswitch/pam_winbind.so /lib/securityLinux/FreeBSD-Specific PAM Configuration/etc/pam.d/samba
The /etc/pam.d/samba file does not need to be changed. I just left this file as it was:
auth required /lib/security/pam_stack.so service=system-auth
account required /lib/security/pam_stack.so service=system-auth
Winbindauthentication serviceloginconsoletelnet loginsftp service/etc/xinetd.d/etc/inetd.conf/etc/xinetd.d/telnet
The other services that I modified to allow the use of Winbind as an authentication service were the normal
login on the console (or a terminal session), telnet logins, and ftp service. In order to enable these
services, you may first need to change the entries in /etc/xinetd.d (or
/etc/inetd.conf). Red Hat Linux 7.1 and later uses the new xinetd.d structure, in this
case you need to change the lines in /etc/xinetd.d/telnet and
/etc/xinetd.d/wu-ftp from:
enable = no
to
enable = yes
ftp serviceshome directory templatedomain users
For ftp services to work properly, you will also need to either have individual directories for the domain
users already present on the server or change the home directory template to a general directory for all
domain users. These can be easily set using the &smb.conf; global entry .
pam_mkhomedir
The directory in is not created automatically! Use pam_mkhomedir or
pre-create the directories of users to make sure users can log in on UNIX with their own home directory.
/etc/pam.d/ftpWinbindftp access
The /etc/pam.d/ftp file can be changed to allow Winbind ftp access in a manner similar to
the /etc/pam.d/samba file. My /etc/pam.d/ftp file was changed to look like this:
auth required /lib/security/pam_listfile.so item=user sense=deny \
file=/etc/ftpusers onerr=succeed
auth sufficient /lib/security/pam_winbind.so
auth required /lib/security/pam_stack.so service=system-auth
auth required /lib/security/pam_shells.so
account sufficient /lib/security/pam_winbind.so
account required /lib/security/pam_stack.so service=system-auth
session required /lib/security/pam_stack.so service=system-auth
/etc/pam.d/login
The /etc/pam.d/login file can be changed in nearly the same way. It now looks like this:
auth required /lib/security/pam_securetty.so
auth sufficient /lib/security/pam_winbind.so
auth sufficient /lib/security/pam_unix.so use_first_pass
auth required /lib/security/pam_stack.so service=system-auth
auth required /lib/security/pam_nologin.so
account sufficient /lib/security/pam_winbind.so
account required /lib/security/pam_stack.so service=system-auth
password required /lib/security/pam_stack.so service=system-auth
session required /lib/security/pam_stack.so service=system-auth
session optional /lib/security/pam_console.so
pam_winbind.sopam_securetty.sopam_unix.so
In this case, I added the auth sufficient /lib/security/pam_winbind.so lines
as before, but also added the required pam_securetty.so above it to disallow
root logins over the network. I also added a sufficient /lib/security/pam_unix.so
use_first_pass line after the winbind.so line to get rid of annoying
double prompts for passwords.
Solaris-Specific Configuration/etc/pam.conf
The /etc/pam.conf needs to be changed. I changed this file so my Domain
users can log on both locally as well as with telnet. The following are the changes
that I made. You can customize the pam.conf file as per your requirements, but
be sure of those changes because in the worst case it will leave your system
nearly impossible to boot.
#
#ident "@(#)pam.conf 1.14 99/09/16 SMI"
#
# Copyright (c) 1996-1999, Sun Microsystems, Inc.
# All Rights Reserved.
#
# PAM configuration
#
# Authentication management
#
login auth required /usr/lib/security/pam_winbind.so
login auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
login auth required /usr/lib/security/$ISA/pam_dial_auth.so.1 try_first_pass
#
rlogin auth sufficient /usr/lib/security/pam_winbind.so
rlogin auth sufficient /usr/lib/security/$ISA/pam_rhosts_auth.so.1
rlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
#
dtlogin auth sufficient /usr/lib/security/pam_winbind.so
dtlogin auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
#
rsh auth required /usr/lib/security/$ISA/pam_rhosts_auth.so.1
other auth sufficient /usr/lib/security/pam_winbind.so
other auth required /usr/lib/security/$ISA/pam_unix.so.1 try_first_pass
#
# Account management
#
login account sufficient /usr/lib/security/pam_winbind.so
login account requisite /usr/lib/security/$ISA/pam_roles.so.1
login account required /usr/lib/security/$ISA/pam_unix.so.1
#
dtlogin account sufficient /usr/lib/security/pam_winbind.so
dtlogin account requisite /usr/lib/security/$ISA/pam_roles.so.1
dtlogin account required /usr/lib/security/$ISA/pam_unix.so.1
#
other account sufficient /usr/lib/security/pam_winbind.so
other account requisite /usr/lib/security/$ISA/pam_roles.so.1
other account required /usr/lib/security/$ISA/pam_unix.so.1
#
# Session management
#
other session required /usr/lib/security/$ISA/pam_unix.so.1
#
# Password management
#
#other password sufficient /usr/lib/security/pam_winbind.so
other password required /usr/lib/security/$ISA/pam_unix.so.1
dtsession auth required /usr/lib/security/$ISA/pam_unix.so.1
#
# Support for Kerberos V5 authentication (uncomment to use Kerberos)
#
#rlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
#login auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
#dtlogin auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
#other auth optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
#dtlogin account optional /usr/lib/security/$ISA/pam_krb5.so.1
#other account optional /usr/lib/security/$ISA/pam_krb5.so.1
#other session optional /usr/lib/security/$ISA/pam_krb5.so.1
#other password optional /usr/lib/security/$ISA/pam_krb5.so.1 try_first_pass
winbind.so
I also added a try_first_pass line after the winbind.so
line to get rid of annoying double prompts for passwords.
Now restart your Samba and try connecting through your application that you
configured in the pam.conf.
ConclusionWinbindNSSPAMRPC callsdomain users
The Winbind system, through the use of the NSS, PAMs, and appropriate Microsoft RPC calls, have allowed us to
provide seamless integration of Microsoft Windows NT domain users on a UNIX system. The result is a great
reduction in the administrative cost of running a mixed UNIX and NT network.
Common Errors
Winbind has a number of limitations in its current released version that we hope to overcome in future releases:
Winbind is currently only available for the Linux, Solaris, AIX, and IRIX operating systems, although
ports to other operating systems are certainly possible. For such ports to be feasible, we require the C
library of the target operating system to support the NSS and PAM systems. This is becoming more common as NSS
and PAM gain support among UNIX vendors.
The mappings of Windows NT RIDs to UNIX IDs is not made algorithmically and depends on the order in
which unmapped users or groups are seen by Winbind. It may be difficult to recover the mappings of RID to UNIX
ID if the file containing this information is corrupted or destroyed.
Currently the Winbind PAM module does not take into account possible workstation and logon time
restrictions that may be set for Windows NT users; this is instead up to the PDC to enforce.
NSCD Problem Warning
Do not under any circumstances run nscd on any system
on which winbindd is running.
If nscd is running on the UNIX/Linux system, then
even though NSSWITCH is correctly configured, it will not be possible to resolve
domain users and groups for file and directory controls.
Winbind Is Not Resolving Users and Groups
My &smb.conf; file is correctly configured. I have specified 12000,
and 3000-3500 and winbind is running.
When I do the following, it all works fine.
&rootprompt;wbinfo -u
MIDEARTH\maryo
MIDEARTH\jackb
MIDEARTH\ameds
...
MIDEARTH\root
&rootprompt;wbinfo -g
MIDEARTH\Domain Users
MIDEARTH\Domain Admins
MIDEARTH\Domain Guests
...
MIDEARTH\Accounts
&rootprompt;getent passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/bin/bash
...
maryo:x:15000:15003:Mary Orville:/home/MIDEARTH/maryo:/bin/false
But the following command just fails:
&rootprompt;chown maryo a_file
chown: `maryo': invalid user
This is driving me nuts! What can be wrong?
Same problem as the one above.
Your system is likely running nscd, the name service
caching daemon. Shut it down, do not restart it! You will find your problem resolved.
Alternately, fix the operation of nscd to resolve the problem.