NAME

       slapo-dynlist - Dynamic List overlay to slapd

SYNOPSIS

       /etc/ldap/slapd.conf

DESCRIPTION

       The  dynlist overlay to slapd(8) allows expansion of dynamic groups and more.  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 entries, and the values of  the
       attributes listed in the URI are added to the original entry.  No recursion is allowed, to
       avoid potential infinite loops.

       Since the resulting entry is dynamically constructed,  it  does  not  exist  until  it  is
       constructed  while  being returned.  As a consequence, dynamically added attributes do not
       participate in the filter matching phase of the search request handling.  In other  words,
       filtering for dynamically added attributes always fails.

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

CONFIGURATION

       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> [[<mapped-ad>:]<member-ad> ...]
              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 URI.

              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  value  member-ad  is  optional;  if  present, the overlay behaves as a dynamic
              group: 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.

              Alternatively,  mapped-ad  can  be  used  to  remap  attributes  obtained   through
              expansion.  member-ad attributes are not filled by expanded DN, but are remapped as
              mapped-ad attributes.  Multiple mapping statements can be used.

       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.

AUTHORIZATION

       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.

EXAMPLE

       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  dynlist.la,  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.

       This example implements the dynamic group feature on the member attribute:

           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

FILES

       /etc/ldap/slapd.conf
              default slapd configuration file

SEE ALSO

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

ACKNOWLEDGEMENTS

       This module was written in 2004 by Pierangelo Masarati for SysNet s.n.c.

       Attribute remapping was contributed in 2008 by Emmanuel Dreyfus.