winbindd (8)


winbindd (8)
Samba
13 Jun 2000
NAME
winbindd - Name Service Switch daemon for resolving names from NT servers 
SYNOPSIS
winbindd [-d debuglevel] [-i] 
DESCRIPTION
This program is part of the Samba suite version 3.0 and describes functionality 
not yet implemented in the main version of Samba. 
winbindd is a daemon that provides a service for the Name Service Switch 
capability that is present in most modern C libraries. 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 following nsswitch databases are implemented by the winbindd service: 
  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


OPTIONS
The following options are available to the winbindd daemon: 
  -d debuglevel
  Sets the debuglevel to an integer between 0 and 100. 0 is for no debugging and 
  100 is for reams and reams. To submit a bug report to the Samba Team, use 
  debug level 100 (see BUGS.txt). 
  -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. 
NAME AND ID RESOLUTION
Users and groups on a Windows NT server are assigned a relative id (rid) which 
is unique for the domain when the user or group is created. To convert the 
Windows NT user or group into a unix user or group, a mapping between rids 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 file under the Samba lock directory and will be remembered. 
WARNING: The rid to unix id database is the only location where the user 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. 
CONFIGURATION
Configuration of the winbindd daemon is done through configuration parameters in 
the smb.conf file. All parameters should be specified in the [global] section of 
smb.conf. 
  winbind separator
  The winbind separator option allows you to specify how NT domain names and 
  user names are combined into unix user names when presented to users. By 
  default winbind will use the traditional \ separator so that the unix user 
  names look like DOMAIN\username. In some cases this separator character may 
  cause problems as the \ character has special meaning in unix shells. In that 
  case you can use the winbind separator option to specify an alternative 
  sepataror character. Good alternatives may be / (although that conflicts with 
  the unix directory separator) or a + character. The + character appears to be 
  the best choice for 100% compatibility with existing unix utilities, but may 
  be an aesthetically bad choice depending on your taste. 
  Default: winbind separator = \ 
  Example: winbind separator = + 
  winbind uid
  The winbind uid parameter specifies the range of user ids that are allocated 
  by the winbindd daemon. This range of ids should have no existing local or nis 
  users within it as strange conflicts can occur otherwise. 
  Default: winbind uid = <empty string> 
  Example: winbind uid = 10000-20000 
  winbind gid
  The winbind gid parameter specifies the range of group ids that are allocated 
  by the winbindd daemon. This range of group ids should have no existing local 
  or nis groups within it as strange conflicts can occur otherwise. 
  Default: winbind gid = <empty string> 
  Example: winbind gid = 10000-20000 
  winbind cache time
  This parameter specifies the number of seconds the winbindd daemon will cache 
  user and group information before querying a Windows NT server again. When a 
  item in the cache is older than this time winbindd will ask the domain 
  controller for the sequence number of the servers account database. If the 
  sequence number has not changed then the cached item is marked as valid for a 
  further "winbind cache time" seconds. Otherwise the item is fetched from the 
  server. This means that as long as the account database is not actively 
  changing winbindd will only have to send one sequence number query packet 
  every "winbind cache time" seconds. 
  Default: winbind cache time = 15 
  template homedir
  When filling out the user information for a Windows NT user, the winbindd 
  daemon uses this parameter to fill in the home directory for that user. If the 
  string %D is present it is substituted with the user's Windows NT domain name. 
  If the string %U is present it is substituted with the user's Windows NT user 
  name. 
  Default: template homedir = /home/%D/%U 
  template shell
  When filling out the user information for a Windows NT user, the winbindd 
  daemon uses this parameter to fill in the shell for that user. 
  Default: template shell = /bin/false 
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 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/pam_securetty.so
	auth       required	/lib/security/pam_nologin.so
	auth       sufficient	/lib/security/pam_winbind.so
	auth       required     /lib/security/pam_pwdb.so use_first_pass shadow nullok


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 samedit program like 
this: 

	samedit -S '*' -W DOMAIN -UAdministrator


Then within samedit run the command: 

	createuser MACHINE$ -j DOMAIN -L


This assumes your domain is called DOMAIN and your Samba workstation is called 
MACHINE. 
Next copy libnss_winbind.so.2 to /lib and pam_winbind.so to /lib/security. 
Finally, setup a smb.conf containing directives like the following: 

  [global]
        winbind separator = +
        winbind cache time = 10
        template shell = /bin/bash
        template homedir = /home/%D/%U
        winbind uid = 10000-20000
        winbind 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 must be running on the local machine for winbindd to work. 
  winbindd queries the list of trusted domains for the Windows NT server on 
  startup and when a SIGHUP is received. Thus, for a running winbindd to become 
  aware of new trust relationships between servers, it must be sent a SIGHUP 
  signal. 
  Client processes resolving names through the winbindd nsswitch module read an 
  environment variable named WINBINDD_DOMAIN. If this variable contains a comma 
  separated list of Windows NT domain names, then winbindd will only resolve 
  users and groups within those Windows NT domains. 
  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. 
  If the the Windows NT RID 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 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. 
  SIGUSR1
  The SIGUSR1 signal will cause winbindd to write status information to the 
  winbind log file including information about the number of user and group ids 
  allocated by winbindd. 
  Log files are stored in the filename specified by the log file parameter. 
FILES
The following files are relevant to the operation of the winbindd daemon. 
  /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. 
  /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. 
SEE ALSO
samba(7), smb.conf(5), nsswitch.conf(5), wbinfo(1) 
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. 
winbindd was written by Tim Potter. 

[İά] meaculpa email:meaculpa@21cn.com
[İ¸] 2001/02/22
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