1 <?xml version="1.0" encoding="iso-8859-1"?>
2 <!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
3 <refentry id="idmap_rid.8">
6 <refentrytitle>idmap_rid</refentrytitle>
7 <manvolnum>8</manvolnum>
8 <refmiscinfo class="source">Samba</refmiscinfo>
9 <refmiscinfo class="manual">System Administration tools</refmiscinfo>
10 <refmiscinfo class="version">4.0</refmiscinfo>
15 <refname>idmap_rid</refname>
16 <refpurpose>Samba's idmap_rid Backend for Winbind</refpurpose>
20 <title>DESCRIPTION</title>
21 <para>The idmap_rid backend provides a way to use an algorithmic
22 mapping scheme to map UIDs/GIDs and SIDs. No database is required
23 in this case as the mapping is deterministic.</para>
26 Note that the idmap_rid module has changed considerably since Samba
27 versions 3.0. and 3.2.
28 Currently, there should to be an explicit idmap configuration for each
29 domain that should use the idmap_rid backend, using disjoint ranges.
30 One usually needs to define a writeable default idmap range, using
31 a backend like <parameter>tdb</parameter> or <parameter>ldap</parameter>
32 that can create unix ids, in order to be able to map the BUILTIN sids
33 and other domains, and also in order to be able to create group mappings.
34 See the example below.
38 Note that the old syntax
39 <parameter>idmap backend = rid:"DOM1=range DOM2=range2 ..."</parameter>
40 is not supported any more since Samba version 3.0.25.
45 <title>IDMAP OPTIONS</title>
49 <term>range = low - high</term>
51 Defines the available matching uid and gid range for which the
52 backend is authoritative. Note that the range acts as a filter.
53 If algorithmically determined UID or GID fall outside the
54 range, they are ignored and the corresponding map is discarded.
55 It is intended as a way to avoid accidental UID/GID overlaps
56 between local and remotely defined IDs.
61 <term>base_rid = INTEGER</term>
63 Defines the base integer used to build SIDs out of a UID or a GID,
64 and to rebase the UID or GID to be obtained from a SID.
65 This means SIDs with a RID less than the base rid are filtered.
66 The default is not to restrict the allowed rids at all,
67 i.e. a base_rid value of 0.
68 A good value for the base_rid can be 1000, since user
69 RIDs by default start at 1000 (512 hexadecimal).
72 Use of this parameter is deprecated.
79 <title>THE MAPPING FORMULAS</title>
81 The Unix ID for a RID is calculated this way:
83 ID = RID - BASE_RID + LOW_RANGE_ID.
87 Correspondingly, the formula for calculating the RID for a
88 given Unix ID is this:
90 RID = ID + BASE_RID - LOW_RANGE_ID.
96 <title>EXAMPLES</title>
98 This example shows how to configure two domains with idmap_rid,
99 the principal domain and a trusted domain, leaving the default
100 id mapping scheme at tdb. The example also demonstrates the use
101 of the base_rid parameter for the trusted domain.
109 idmap config * : backend = tdb
110 idmap config * : range = 1000000-1999999
112 idmap config MAIN : backend = rid
113 idmap config MAIN : range = 10000 - 49999
115 idmap config TRUSTED : backend = rid
116 idmap config TRUSTED : range = 50000 - 99999
117 idmap config TRUSTED : base_rid = 1000
122 <title>AUTHOR</title>
125 The original Samba software and related utilities
126 were created by Andrew Tridgell. Samba is now developed
127 by the Samba Team as an Open Source project similar
128 to the way the Linux kernel is developed.