winbindd — Name Service Switch daemon for resolving names from NT servers
winbindd [-D] [-F] [-S] [-i] [-Y] [-d <debug level>] [-s <smb config file>] [-n]
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 arbitrary 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 configuration 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
	through 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:
If specified, this parameter causes
		the server to operate as a daemon. That is, it detaches
		itself and runs in the background on the appropriate port. 
		This switch is assumed if winbindd is 
		executed on the command line of a shell.
		
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.
		
User information traditionally stored in
		the passwd(5) file and used by
		getpwent(3) functions. 
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: use winbind to resolve hosts: # hosts: files dns winbind ## All other NSS enabled systems should use libnss_wins.so like this: hosts: files dns wins
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
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.
		
If specified, this parameter causes
		winbindd to log to standard output rather
		than a file.
level is an integer 
from 0 to 10. The default value if this parameter is 
not specified is 0.
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 log level parameter
in the smb.conf file.
Prints the program version number.
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.
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.
Print a summary of command line options.
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.
		
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.
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.
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 idmap domains or the old idmap backend parameters in
        smb.conf for options for sharing this
        database, such as via LDAP.
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: rpc only Setting this parameter forces winbindd to use RPC instead of LDAP to retrieve information from Domain Controllers.
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
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.
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 idmap backend 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.
The following signals can be used to manipulate the
	winbindd daemon. 
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.
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.
/etc/nsswitch.conf(5)Name service switch configuration file.
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. 
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. 
Implementation of name service switch library.
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
		. 
Storage for cached user and group information.
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.