The LMF User Primer

This document serves as a primer for the DIGITAL Vendor-Specific Module (DVSM) Interface to the VMS License Management Facility (LMF), specifically for use with layered products. It is divided into two main parts.

Part one provides an overview of the LMF and its product numbering scheme, which follows a "2-5-2" format (two-character prefix, five-character part number, two-character suffix). It details various license types such as Traditional, ClusterWide, User/Activity, and Loan-of-Products licenses, explaining how these types influence the Product Authorization Key (PAK) fields. Key PAK components like product name, units, availability, and activity codes are described, along with their roles in license activation and unit deduction. The document also mentions that tabular information is derived from the U.S. Price Book (Jan 10, 1989).

Part two describes the subroutine calls necessary to support LMF in layered products. It focuses on:

• SYS$LOOKUP_LICENSE: The primary interface for DIGITAL layered products, which calls SYS$GRANT_LICENSE. It grants a caller permission to execute a specified product if a valid license exists, checking against product name, release date, and version. It uses arguments for product name, an item list (including product version and release date), producer, flags, context, and the licensed product name.
• SYS$RELEASE_LICENSE: Revokes a process's authorization to execute a licensed product, particularly useful for user/activity licenses to release units prior to image run-down.
• SYS$GETLUI: Intended to return information about the in-memory license database, though noted as "not yet implemented" at the time of publication.

The document emphasizes that these routines are specifically for DIGITAL layered products and incorporate DIGITAL-specific business rules, not intended for general customer or non-DIGITAL software use. An example C program demonstrating the use of SYS$LOOKUP_LICENSE and SYS$RELEASE_LICENSE is included.