idmap_ad — Samba's idmap_ad Backend for Winbind
The idmap_ad plugin provides a way for Winbind to read id mappings from an AD server that uses RFC2307/SFU schema extensions. This module implements only the "idmap" API, and is READONLY. Mappings must be provided in advance by the administrator by adding the posixAccount/posixGroup classes and relative attribute/value pairs to the user and group objects in the AD.
Note that the idmap_ad module has changed considerably since
Samba versions 3.0 and 3.2.
Currently, the ad backend
does not work as the the default idmap backend, but one has
to configure it separately for each domain for which one wants
to use it, using disjoint ranges. One usually needs to configure
a writeable default idmap range, using for example the
tdb or ldap
backend, in order to be able to map the BUILTIN sids and
possibly other trusted domains. The writeable default config
is also needed in order to be able to create group mappings.
This catch-all default idmap configuration should have a range
that is disjoint from any explicitly configured domain with
idmap backend ad. See the example below.
Defines the available matching UID and GID range for which the backend is authoritative. Note that the range acts as a filter. If specified any UID or GID stored in AD that fall outside the range is ignored and the corresponding map is discarded. It is intended as a way to avoid accidental UID/GID overlaps between local and remotely defined IDs.
Defines the schema that idmap_ad should use when querying Active Directory regarding user and group information. This can be either the RFC2307 schema support included in Windows 2003 R2 or the Service for Unix (SFU) schema.
The following example shows how to retrieve idmappings from our principal and trusted AD domains. If trusted domains are present id conflicts must be resolved beforehand, there is no guarantee on the order conflicting mappings would be resolved at this point. This example also shows how to leave a small non conflicting range for local id allocation that may be used in internal backends like BUILTIN.
[global] idmap config * : backend = tdb idmap config * : range = 1000000-1999999 idmap config CORP : backend = ad idmap config CORP : range = 1000-999999