slapo-dynlist(5) — Linux manual page


SLAPO-DYNLIST(5)           File Formats Manual          SLAPO-DYNLIST(5)

NAME         top

       slapo-dynlist - Dynamic List overlay to slapd

SYNOPSIS         top


DESCRIPTION         top

       The dynlist overlay to slapd(8) allows expansion of dynamic lists
       and groups.  Any time an entry with a specific objectClass
       (defined in the overlay configuration) is being returned, the
       LDAP URI-valued occurrences of a specific attribute (also defined
       in the overlay configuration) are expanded into the corresponding

       For a dynamic list, the values of the attributes listed in the
       URI are added from the matching entries to the original entry.
       No recursion is allowed, to avoid potential infinite loops.  The
       resulting entry must comply with the LDAP data model, so
       constraints are enforced.  For example, if a SINGLE-VALUE
       attribute is listed, only the first value found during the list
       expansion appears in the final entry.

       For a dynamic group, the DNs of the matching entries are added to
       a member attribute in the original entry.

       All dynamic behavior is disabled when the manageDSAit control
       (RFC 3296) is used.  In that case, the contents of the original
       entry is returned; namely, the URLs are returned instead of being


       The config directives that are specific to the dynlist overlay
       must be prefixed by dynlist-, to avoid potential conflicts with
       directives specific to the underlying database or to other
       stacked overlays.

       overlay dynlist
              This directive adds the dynlist overlay to the current
              database, or to the frontend, if used before any database
              instantiation; see slapd.conf(5) for details.

       This slapd.conf configuration option is defined for the dynlist
       overlay. It may have multiple occurrences, and it must appear
       after the overlay directive.

       dynlist-attrset <group-oc> [<URI>] <URL-ad> [options]

              The value group-oc is the name of the objectClass that
              triggers the dynamic expansion of the data.

              The optional URI restricts expansion only to entries
              matching the DN, the scope and the filter portions of the

              The value URL-ad is the name of the attributeDescription
              that contains the URI that is expanded by the overlay; if
              none is present, no expansion occurs.  If the intersection
              of the attributes requested by the search operation (or
              the asserted attribute for compares) and the attributes
              listed in the URI is empty, no expansion occurs for that
              specific URI.  It must be a subtype of labeledURI.

              The remaining options depend on whether a dynamic list or
              a dynamic group is being configured.

              For a dynamic list, the allowed options have the form

              [<mapped-ad>:<list-ad> ...]

              The mapped-ad can be used to remap attributes obtained
              through expansion.  The list-ad must be one of the
              attributes returned in the expansion of the URIs in the
              URL-ad attribute of the dynamic entry. Multiple mapping
              statements can be used.  Note that in order for dynamic
              lists to be usable in a search filter, the dynamic
              attributes to be filtered must be explicitly mapped. They
              can be mapped to themselves if no transformation is

              For a dynamic group, the allowed options are


              The member-ad is required; this attribute will list the DN
              of the entries resulting from the internal search.  In
              this case, the attrs portion of the URIs in the URL-ad
              attribute must be absent, and the DNs of all the entries
              resulting from the expansion of the URIs are listed as
              values of this attribute.  Compares that assert the value
              of the member-ad attribute of entries with group-oc
              objectClass apply as if the DN of the entries resulting
              from the expansion of the URI were present in the group-oc
              entry as values of the member-ad attribute.  If the
              optional memberOf-ad attribute is also specified, then it
              will be populated with the DNs of the dynamic groups that
              an entry is a member of.  If the optional static-oc
              objectClass is also specified, then the memberOf attribute
              will also be populated with the DNs of the static groups
              that an entry is a member of.  If the optional * character
              is also specified, then the member and memberOf values
              will be populated recursively, for nested groups. Note
              that currently nesting is only supported for Search
              operations, not Compares.

       dynlist-simple TRUE | FALSE
              This option downgrades to the behavior of the OpenLDAP 2.4
              dynlist overlay.  It disables memberOf processing, nested
              group support, and filter evaluation of dynamically
              generated values.  The default is FALSE.

       The dynlist overlay may be used with any backend, but it is
       mainly intended for use with local storage backends.  In case the
       URI expansion is very resource-intensive and occurs frequently
       with well-defined patterns, one should consider adding a
       proxycache later on in the overlay stack.


       By default the expansions are performed using the identity of the
       current LDAP user.  This identity may be overridden by setting
       the dgIdentity attribute in the group's entry to the DN of
       another LDAP user.  In that case the dgIdentity will be used when
       expanding the URIs in the object.  Setting the dgIdentity to a
       zero-length string will cause the expansions to be performed
       anonymously.  Note that the dgIdentity attribute is defined in
       the dyngroup schema, and this schema must be loaded before the
       dgIdentity authorization feature may be used.  If the dgAuthz
       attribute is also present in the group's entry, its values are
       used to determine what identities are authorized to use the
       dgIdentity to expand the group.  Values of the dgAuthz attribute
       must conform to the (experimental) OpenLDAP authz syntax.  When
       using dynamic memberOf in search filters, search access to the
       entryDN pseudo-attribute is required.

EXAMPLE         top

       This example collects all the email addresses of a database into
       a single entry; first of all, make sure that slapd.conf contains
       the directives:

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL

       and that slapd loads, if compiled as a run-time
       module; then add to the database an entry like

           dn: cn=Dynamic List,ou=Groups,dc=example,dc=com
           objectClass: groupOfURLs
           cn: Dynamic List
           memberURL: ldap:///ou=People,dc=example,dc=com?mail?sub?(objectClass=person)

       If no <attrs> are provided in the URI, all (non-operational)
       attributes are collected.

       The values of the above list can not be evaluated in a search
       filter. To enable filter evaluation on the dynamic list, the
       configuration must be changed to explicitly map the dynamic
       attributes to be filtered. In this case mail is just mapped to

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL mail:mail

       This example implements the dynamic group feature on the member

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL member

       A dynamic group with dgIdentity authorization could be created
       with an entry like

           dn: cn=Dynamic Group,ou=Groups,dc=example,dc=com
           objectClass: groupOfURLs
           objectClass: dgIdentityAux
           cn: Dynamic Group
           memberURL: ldap:///ou=People,dc=example,dc=com??sub?(objectClass=person)
           dgIdentity: cn=Group Proxy,ou=Services,dc=example,dc=com

       This example extends the dynamic group feature to add a dynamic
       dgMemberOf attribute to all the members of a dynamic group:

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL member+dgMemberOf

       This example extends the dynamic memberOf feature to add the
       memberOf attribute to all the members of both static and dynamic

           include /path/to/dyngroup.schema
           # ...

           database <database>
           # ...

           overlay dynlist
           dynlist-attrset groupOfURLs memberURL member+memberOf@groupOfNames

       This dynamic memberOf feature can fully replace the functionality
       of the slapo-memberof(5) overlay.

FILES         top

              default slapd configuration file


       The dynlist overlay has been reworked with the 2.5 release to use
       a consistent namespace as with other overlays. As a side-effect
       the following cn=config parameters are deprecated and will be
       removed in a future release: olcDlAttrSet is replaced with
       olcDynListAttrSet olcDynamicList is replaced with

SEE ALSO         top

       slapd.conf(5), slapd-config(5), slapd(8).  The slapo-dynlist(5)
       overlay supports dynamic configuration via back-config.

BUGS         top

       Filtering on dynamic groups may return incomplete results if the
       search operation uses the pagedResults control.


       This module was written in 2004 by Pierangelo Masarati for SysNet

       Attribute remapping was contributed in 2008 by Emmanuel Dreyfus.

COLOPHON         top

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Pages that refer to this page: slapd.overlays(5)slapo-dynlist(5)slapo-memberof(5)