This overlay is intended to be used to force syntactic regularity upon certain string represented data which have well known canonical forms, like telephone numbers, post codes, FQDNs, etc.

It constrains only LDAP adds and modify commands and only seeks to control the add and modify value of a modify request.

constraint_attribute <attribute_name> <type> <value> Specifies the constraint which should apply to the attribute named as the first parameter. Two types of constraint are currently supported - regex , size , count , and uri . The parameter following the regex type is a Unix style regular expression (See regex (7) ). The parameter following the uri type is an LDAP URI. The URI will be evaluated using an internal search. It must not include a hostname, and it must include a list of attributes to evaluate. The size type can be used to enfore a limit on an attribute length, and the count type limits the count of an attribute. Any attempt to add or modify an attribute named as part of the constraint overlay specification which does not fit the constraint listed will fail with a LDAP_CONSTRAINT_VIOLATION error.

overlay constraint
constraint_attribute jpegPhoto size 131072
constraint_attribute userPassword count 3
constraint_attribute mail regex ^[:alnum:]+@mydomain.com$
constraint_attribute title uri
 ldap:///dc=catalog,dc=example,dc=com?title?sub?(objectClass=titleCatalog)

ETCDIR/slapd.conf default slapd configuration file