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WINBINDD(8)
NAME
winbindd - Name Service Switch daemon for resolving names from NT servers
SYNOPSIS
winbindd [-F] [-S] [-i] [-Y] [-d<debuglevel>] [-s<smbconfigfile>] [-n]
DESCRIPTION
This program is part of the samba(7) suite.
winbindd is a daemon that provides a number of services to the Name Service
Switch capability found in most modern C libraries, to arbitary
applications via PAM and ntlm_auth and to Samba itself.
Even if winbind is not used for nsswitch, it still provides a service to
smbd, ntlm_auth and the pam_winbind.so PAM module, by managing connections
to domain controllers. In this configuraiton the idmap uid and idmap gid
parameters are not required. (This is known as `netlogon proxy only mode'.)
The Name Service Switch allows user and system information to be obtained
from different databases services such as NIS or DNS. The exact behaviour
can be configured throught the /etc/nsswitch.conf file. Users and groups
are allocated as they are resolved to a range of user and group ids
specified by the administrator of the Samba system.
The service provided by winbindd is called `winbind' and can be used to
resolve user and group information from a Windows NT server. The service
can also provide authentication services via an associated PAM module.
The pam_winbind module supports the auth, account and password module-
types. It should be noted that the account module simply performs a
getpwnam() to verify that the system can obtain a uid for the user, as the
domain controller has already performed access control. If the
libnss_winbind library has been correctly installed, or an alternate source
of names configured, this should always succeed.
The following nsswitch databases are implemented by the winbindd service:
hosts
This feature is only available on IRIX. User information traditionally
stored in the hosts(5) file and used by gethostbyname(3) functions.
Names are resolved through the WINS server or by broadcast.
passwd
User information traditionally stored in the passwd(5) file and used by
getpwent(3) functions.
group
Group information traditionally stored in the group(5) file and used by
getgrent(3) functions.
For example, the following simple configuration in the /etc/nsswitch.conf
file can be used to initially resolve user and group information from
/etc/passwd and /etc/group and then from the Windows NT server.
passwd: files winbind
group: files winbind
## only available on IRIX; Linux users should us libnss_wins.so
hosts: files dns winbind
The following simple configuration in the /etc/nsswitch.conf file can be
used to initially resolve hostnames from /etc/hosts and then from the WINS
server.
hosts: files wins
OPTIONS
-F
If specified, this parameter causes the main winbindd process to not
daemonize, i.e. double-fork and disassociate with the terminal. Child
processes are still created as normal to service each connection
request, but the main process does not exit. This operation mode is
suitable for running winbindd under process supervisors such as
supervise and svscan from Daniel J. Bernstein's daemontools package, or
the AIX process monitor.
-S
If specified, this parameter causes winbindd to log to standard output
rather than a file.
-V
Prints the program version number.
-s <configuration file>
The file specified contains the configuration details required by the
server. The information in this file includes server-specific
information such as what printcap file to use, as well as descriptions
of all the services that the server is to provide. See smb.conf for more
information. The default configuration file name is determined at
compile time.
-d|--debuglevel=level
level is an integer from 0 to 10. The default value if this parameter is
not specified is zero.
The higher this value, the more detail will be logged to the log files
about the activities of the server. At level 0, only critical errors and
serious warnings will be logged. Level 1 is a reasonable level for day-
to-day running - it generates a small amount of information about
operations carried out.
Levels above 1 will generate considerable amounts of log data, and
should only be used when investigating a problem. Levels above 3 are
designed for use only by developers and generate HUGE amounts of log
data, most of which is extremely cryptic.
Note that specifying this parameter here will override the
parameter in the smb.conf file.
-l|--logfile=logdirectory
Base directory name for log/debug files. The extension ".progname" will
be appended (e.g. log.smbclient, log.smbd, etc...). The log file is
never removed by the client.
-h|--help
Print a summary of command line options.
-i
Tells winbindd to not become a daemon and detach from the current
terminal. This option is used by developers when interactive debugging
of winbindd is required. winbindd also logs to standard output, as if
the -S parameter had been given.
-n
Disable caching. This means winbindd will always have to wait for a
response from the domain controller before it can respond to a client
and this thus makes things slower. The results will however be more
accurate, since results from the cache might not be up-to-date. This
might also temporarily hang winbindd if the DC doesn't respond.
-Y
Single daemon mode. This means winbindd will run as a single process
(the mode of operation in Samba 2.2). Winbindd's default behavior is to
launch a child process that is responsible for updating expired cache
entries.
NAME AND ID RESOLUTION
Users and groups on a Windows NT server are assigned a security id (SID)
which is globally unique when the user or group is created. To convert the
Windows NT user or group into a unix user or group, a mapping between SIDs
and unix user and group ids is required. This is one of the jobs that
winbindd performs.
As winbindd users and groups are resolved from a server, user and group ids
are allocated from a specified range. This is done on a first come, first
served basis, although all existing users and groups will be mapped as soon
as a client performs a user or group enumeration command. The allocated
unix ids are stored in a database and will be remembered.
WARNING: The SID to unix id database is the only location where the user
and group mappings are stored by winbindd. If this store is deleted or
corrupted, there is no way for winbindd to determine which user and group
ids correspond to Windows NT user and group rids.
See the
or the old
parameters in smb.conf for options for sharing this database, such as via
LDAP.
CONFIGURATION
Configuration of the winbindd daemon is done through configuration
parameters in the smb.conf(5) file. All parameters should be specified in
the [global] section of smb.conf.
•
winbind separator
•
idmap uid
•
idmap gid
•
idmap backend
•
winbind cache time
•
winbind enum users
•
winbind enum groups
•
template homedir
•
template shell
•
winbind use default domain
EXAMPLE SETUP
To setup winbindd for user and group lookups plus authentication from a
domain controller use something like the following setup. This was tested
on an early Red Hat Linux box.
In /etc/nsswitch.conf put the following:
passwd: files winbind
group: files winbind
In /etc/pam.d/* replace the auth lines with something like this:
auth required /lib/security/pam_securetty.so
auth required /lib/security/pam_nologin.so
auth sufficient /lib/security/pam_winbind.so
auth required /lib/security/pam_unix.so use_first_pass shadow nullok
Note
The PAM module pam_unix has recently replaced the module pam_pwdb. Some
Linux systems use the module pam_unix2 in place of pam_unix.
Note in particular the use of the sufficient keyword and the
use_first_pass keyword.
Now replace the account lines with this:
account required /lib/security/pam_winbind.so
The next step is to join the domain. To do that use the net program like
this:
net join -S PDC -U Administrator
The username after the -U can be any Domain user that has administrator
privileges on the machine. Substitute the name or IP of your PDC for "PDC".
Next copy libnss_winbind.so to /lib and pam_winbind.so to /lib/security. A
symbolic link needs to be made from /lib/libnss_winbind.so to
/lib/libnss_winbind.so.2. If you are using an older version of glibc then
the target of the link should be /lib/libnss_winbind.so.1.
Finally, setup a smb.conf(5) containing directives like the following:
[global]
winbind separator = +
winbind cache time = 10
template shell = /bin/bash
template homedir = /home/%D/%U
idmap uid = 10000-20000
idmap gid = 10000-20000
workgroup = DOMAIN
security = domain
password server = *
Now start winbindd and you should find that your user and group database is
expanded to include your NT users and groups, and that you can login to
your unix box as a domain user, using the DOMAIN+user syntax for the
username. You may wish to use the commands getent passwd and getent group
to confirm the correct operation of winbindd.
NOTES
The following notes are useful when configuring and running winbindd:
nmbd(8) must be running on the local machine for winbindd to work.
PAM is really easy to misconfigure. Make sure you know what you are doing
when modifying PAM configuration files. It is possible to set up PAM such
that you can no longer log into your system.
If more than one UNIX machine is running winbindd, then in general the user
and groups ids allocated by winbindd will not be the same. The user and
group ids will only be valid for the local machine, unless a shared
is configured.
If the the Windows NT SID to UNIX user and group id mapping file is damaged
or destroyed then the mappings will be lost.
SIGNALS
The following signals can be used to manipulate the winbindd daemon.
SIGHUP
Reload the smb.conf(5) file and apply any parameter changes to the
running version of winbindd. This signal also clears any cached user and
group information. The list of other domains trusted by winbindd is also
reloaded.
SIGUSR2
The SIGUSR2 signal will cause winbindd to write status information to
the winbind log file.
Log files are stored in the filename specified by the log file
parameter.
FILES
/etc/nsswitch.conf(5)
Name service switch configuration file.
/tmp/.winbindd/pipe
The UNIX pipe over which clients communicate with the winbindd program.
For security reasons, the winbind client will only attempt to connect to
the winbindd daemon if both the /tmp/.winbindd directory and
/tmp/.winbindd/pipe file are owned by root.
$LOCKDIR/winbindd_privileged/pipe
The UNIX pipe over which 'privileged' clients communicate with the
winbindd program. For security reasons, access to some winbindd
functions - like those needed by the ntlm_auth utility - is restricted.
By default, only users in the 'root' group will get this access, however
the administrator may change the group permissions on
$LOCKDIR/winbindd_privileged to allow programs like 'squid' to use
ntlm_auth. Note that the winbind client will only attempt to connect to
the winbindd daemon if both the $LOCKDIR/winbindd_privileged directory
and $LOCKDIR/winbindd_privileged/pipe file are owned by root.
/lib/libnss_winbind.so.X
Implementation of name service switch library.
$LOCKDIR/winbindd_idmap.tdb
Storage for the Windows NT rid to UNIX user/group id mapping. The lock
directory is specified when Samba is initially compiled using the --
with-lockdir option. This directory is by default
/usr/local/samba/var/locks .
$LOCKDIR/winbindd_cache.tdb
Storage for cached user and group information.
VERSION
This man page is correct for version 3.0 of the Samba suite.
SEE ALSO
nsswitch.conf(5), samba(7), wbinfo(1), ntlm_auth(8), smb.conf(5),
pam_winbind(8)
AUTHOR
The original Samba software and related utilities were created by Andrew
Tridgell. Samba is now developed by the Samba Team as an Open Source
project similar to the way the Linux kernel is developed.
wbinfo and winbindd were written by Tim Potter.
The conversion to DocBook for Samba 2.2 was done by Gerald Carter. The
conversion to DocBook XML 4.2 for Samba 3.0 was done by Alexander Bokovoy.
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Index for
Section 8 |
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Alphabetical
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