The server calls this filter matching function when processing an extensible match filter using a matching rule plug-in. An extensible match filter specifies either the OID of a matching rule, or an attribute type, or both, that indicates how matching entries are found. For example, a sound-alike matching rule could be implemented to find all entries that sound like a given value.
To handle the extensible match filter for a matching rule, implement both this callback and a filter factor that creates the filter structure, filter. The callback retrieves information about the filter from this structure, such as the attribute type and value, then compares this information with attribute types and values in the candidate entry.