Composite Names
A composite name is represented by an object of type FN_composite_name_t. A composite name is a sequence of components, where each component is a string (of type FN_string_t) intended to contain a name from a single naming system. (See "Syntax"for a description of composite name syntax and structure.) Operations are provided to iterate over this sequence, modify it, and compare two composite names.
References and Addresses
A reference is represented by the type FN_ref_t. An object of this type contains a reference type and a list of addresses. The ordering in this list at the time of binding might not be preserved when the reference is returned upon lookup.
The reference type is represented by an object of type FN_identifier_t. The reference type is intended to identify the class of object referenced, but XFN does not dictate its precise use.
Each address in a reference is represented by an object of type FN_ref_addr_t. An address consists of an opaque data buffer and a type field, again of type FN_identifier_t. The address type is intended to identify the mechanism that should be used to reach the object using that address.
Multiple addresses in a single reference are intended to identify multiple communication endpoints for the same conceptual object. Multiple addresses can arise for various reasons; for example, because the object offers interfaces over more than one communication mechanism.
The client process must interpret the contents of the opaque buffers based on the type of the address and on the type of the reference. However, this interpretation is intended to occur below the application layer.
Most application developers should not be required to manipulate the contents of either address or reference objects themselves. These interfaces are generally used within service libraries.
Identifiers
Identifiers are used to identify reference types and address types in the reference and to identify attributes and their syntax in the attribute operations.
The FN_identifier_t type is used to represent an identifier. It consists of an unsigned integer, which determines the format of identifier, and the actual identifier, which is expressed as a sequence of octets.
XFN defines a small number of standard forms for identifiers, as shown in Table 2-4.
Table 2-4 XFN Identifier Formats
Identifier Format | Description |
|---|---|
The identifier is an ASCII string (ISO 646). | |
The identifier is an OSF DCE UUID in string representation. See the X/Open DCE RPC (ISBN 1-872630-95-2). | |
The identifier is an ISO OID in ASN.1 dot-separated integer list string format. See the ISO ASN.1 (ISO 8824). |
Strings
The FN_string_t type represents character strings in the XFN interface. It provides a layer of insulation from specific string representations. The FN_string_t operations contain operations for string comparison, substring searches, and manipulation. The FN_string_t type supports multiple code sets. In Solaris 2.5, FNS supports ISO 646.
Attributes and Attribute Values
An attribute is represented by the FN_attribute_t type, and contains:
An attribute identifier (of type FN_identifier_t)
A syntax (of type FN_identifier_t)
A set of distinct values (each value is a sequence of octets of type FN_attrvalue_t)
Various operations allow the construction, destruction, and manipulation of an attribute.
Attribute Sets
An attribute set is a set of attribute objects with distinct attribute identifiers. Attribute sets are represented by the FN_attrset_t type.
There are operations to allow the construction, destruction, and manipulation of an attribute set.
Attribute-Modification Lists
Use an attribute-modification list to specify multiple modification operations to be performed on the attributes associated with a single named object.
An attribute-modification list is represented by the FN_attrmodlist_t type. It consists of an ordered list of attribute-modification specifiers. Each specifier contains an operation and an attribute object. The attribute's identifier indicates the attribute that is to be operated upon. How the attribute's values are used depends on the operation.
The operation specifier is one of the values described in Table 2-1. The operations should be done in the order in which they appear in the list.
Parameters Used in Extended Search (Preliminary Specification)
The types of objects used to specify the scope and details of an extended search operation:
the search control operations (FN_search_control_t)
the search filter expression (FN_search_filter_t)
Search Control
The FN_search_control_t object encapsulates the different options that the application can specify in controlling the scope and the return values of the extended search operation, fn_attr_ext_search() .
These options are:
Scope of search. This determines which contexts and objects will be searched. The default is FN_SEARCH_ONE_CONTEXT.
Table 2-5 Different Scopes for Searching
Scope | Meaning |
|---|---|
FN_SEARCH_NAMED_OBJECT | Search just the given named object. |
FN_SEARCH_ONE_CONTEXT | Search just the given context. |
FN_SEARCH_SUBTREE | Search given context and all its subcontexts. |
FN_SEARCH_CONSTRAINED_SUBTREE | Search given context and its subcontexts as constrained by the context-specific policy in place at the named context. |
Follow links during search. This determines whether links encountered during the search will be followed. The initial resolution phase of the operation (the resolution up to the target context) always follow links. This option controls the following of links after reaching the target context.
The default is to not follow links.
Maximum names returned. This specifies the maximum number of names to be returned before terminating the search. A value of 0 indicates that the search is terminated only when all the context and objects specified by the scope have been searched.
The default is to return all named objects found.
Return reference. This determines whether the reference of the object is returned.
The default is to not return the reference.
Return attributes. This determines which attributes associated with the named object, if any, are returned.
The default is to not return any attributes.