Manual Pages for UNIX Darwin command on man winbindd

WINBINDD(8) WINBINDD(8)

NAME

winbindd - Name Service Switch daemon for resolving names from NT

servers

SYNOPSIS

wwiinnbbiinndddd [-F] [-S] [-i] [-Y] [-d ] [-s ]

[-n]

DESCRIPTION

This program is part of the ssaammbbaa(7) suite. wwiinnbbiinndddd 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 nnttllmmaauutthh and to Samba itself. Even if winbind is not used for nsswitch, it still provides a service

to ssmmbbdd, nnttllmmaauutthh and the ppaammwwiinnbbiinndd..ssoo PAM module, by managing con-

nections 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 ob-

tained 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 wwiinnbbiinndddd is called `winbind' and can be used to

resolve user and group information from a Windows NT server. The ser-

vice can also provide authentication services via an associated PAM module.

The pamwinbind module supports the auth, account and password mod-

ule-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 lib-

nsswinbind 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 ser-

vice:

hosts This feature is only available on IRIX. User information tradi-

tionally stored in the hosts(5) file and used byggeetthhoossttbbyynnaammee((33)) functions. Names are resolved through the WINS server or by broadcast. passwd User information traditionally stored in the passwd(5) file and used byggeettppwweenntt((33)) functions. group Group information traditionally stored in the group(5) file and used byggeettggrreenntt((33)) functions.

For example, the following simple configuration in the/etc/nss-

witch.conf file can be used to initially resolve user and group infor-

mation 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 libnsswins.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 OOPPTTIIOONNSS

-F If specified, this parameter causes the main wwiinnbbiinndddd process to

not daemonize, i.e. double-fork and disassociate with the termi-

nal. Child processes are still created as normal to service each

connection request, but the main process does not exit. This op-

eration mode is suitable for runningwwiinnbbiinndddd under process su-

pervisors such as ssuuppeerrvviissee and ssvvssccaann from Daniel J. Bern-

stein's ddaaeemmoonnttoooollss package, or the AIX process monitor.

-S If specified, this parameter causeswwiinnbbiinndddd to log to standard

output rather than a file.

-V Prints the program version number.

-s

The file specified contains the configuration details required

by the server. The information in this file includes server-spe-

cific 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|-debug=debuglevel

debuglevel 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 crit-

ical 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.

-l|-logfile=logdirectory

Base directory name for log/debug files. The extension ""..pprroogg-

nnaammee"" 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 wwiinnbbiinndddd to not become a daemon and detach from the cur-

rent terminal. This option is used by developers when interac-

tive debugging of wwiinnbbiinndddd is required.wwiinnbbiinndddd also logs to

standard output, as if the -SS 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 map-

ping between SIDs and unix user and group ids is required. This is one of the jobs that wwiinnbbiinndddd 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 com-

mand. The allocated unix ids are stored in a database file under the Samba lock directory and will be remembered.

WARNING: The SID to unix id database is the only location where the us-

er and group mappings are stored by winbindd. If this file 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 backend parameter in smb.conf for options for sharing this database, such as via LDAP. CCOONNFFIIGGUURRAATTIIOONN

Configuration of the wwiinnbbiinndddd daemon is done through configuration pa-

rameters in the ssmmbb..ccoonnff(5) file. All parameters should be specified in the [global] section of smb.conf. +o winbind separator +o idmap uid +o idmap gid +o idmap backend +o winbind cache time +o winbind enum users +o winbind enum groups +o template homedir +o template shell +o winbind use default domain EEXXAAMMPPLLEE SSEETTUUPP

To setup winbindd for user and group lookups plus authentication from a

domain controller use something like the following setup. This was tested on a RedHat 6.2 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/pamsecuretty.so auth required /lib/security/pamnologin.so auth sufficient /lib/security/pamwinbind.so auth required /lib/security/pampwdb.so usefirstpass shadow nullok Note in particular the use of the sufficient keyword and the usefirstpass keyword. Now replace the account lines with this: aaccccoouunntt rreeqquuiirreedd //lliibb//sseeccuurriittyy//ppaammwwiinnbbiinndd..ssoo The next step is to join the domain. To do that use thenneett program like this:

nneett jjooiinn -SS PPDDCC -UU AAddmmiinniissttrraattoorr

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 libnsswinbind.so to/lib and pamwinbind.so to /lib/securi-

ty. A symbolic link needs to be made from /lib/libnsswinbind.so to/lib/libnsswinbind.so.2. If you are using an older version of glibc then the target of the link should be/lib/libnsswinbind.so.1. Finally, setup a ssmmbb..ccoonnff(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 data-

base 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 ggeetteenntt ppaasssswwdd and

ggeetteenntt ggrroouupp to confirm the correct operation of winbindd.

NNOOTTEESS The following notes are useful when configuring and running wwiinnbbiinndddd: nnmmbbdd(8) must be running on the local machine for wwiinnbbiinndddd to work.

PAM is really easy to misconfigure. Make sure you know what you are do-

ing 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 wwiinnbbiinndddd, then in general the

user and groups ids allocated by winbindd will not be the same. The us-

er 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. SSIIGGNNAALLSS The following signals can be used to manipulate thewwiinnbbiinndddd daemon. SIGHUP Reload the ssmmbb..ccoonnff(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 wwiinnbbiinndddd to write status informa-

tion 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 wwiinnbbiinndddd

program. For security reasons, the winbind client will only at-

tempt to connect to the winbindd daemon if both the /tmp/.win-

bindd directory and /tmp/.winbindd/pipe file are owned by root.

$LOCKDIR/winbinddprivilaged/pipe

The UNIX pipe over which 'privilaged' clients communicate with

the wwiinnbbiinndddd program. For security reasons, access to some win-

bindd functions - like those needed by the nnttllmmaauutthh 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/winbinddprivilaged to allow programs

like 'squid' to use ntlmauth. Note that the winbind client will

only attempt to connect to the winbindd daemon if both the

$LOCKDIR/winbinddprivilaged directory and $LOCKDIR/win-

binddprivilaged/pipe file are owned by root. /lib/libnsswinbind.so.X Implementation of name service switch library.

$LOCKDIR/winbinddidmap.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/winbinddcache.tdb

Storage for cached user and group information. VVEERRSSIIOONN This man page is correct for version 3.0 of the Samba suite.