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HP-UX 11i Version 3: February 2007
acps_spi: acpm_getenvattrs(), acpm_getobj(), acpm_getobjattrs(), acpm_getop(), acpm_getopattrs(), acpm_getsubattrs(), acpm_getsubcreds(), acpm_getsubid() — ACPS Service Provider Interface
#include <acps.h> #include <acps_spi.h>
cc [flag]... file... -lacps [library]...
int acpm_getenvattrs( acp_handle_t h, acp_attr_node *head);
int acpm_getobj( acp_handle_t h, char **type, char ** object );
int acpm_getobjattrs( acp_handle_t h, acp_attr_node **head);
int acpm_getop( acp_handle_t h, char **type, char **operation);
int acpm_getopattrs( acp_handle_t h, acp_attr_node **head);
int acpm_getsubattrs( acp_handle_t h, acp_attr_node **head);
int acpm_getsubcreds( acp_handle_t h, acp_attr_node **head);
int acpm_getsubid( acp_handle_t h, char **type, char **id);
The ACPS Service Provider Interface makes it possible to define a custom module that responds to access control requests. This module is typically written either to enforce a custom policy, or to interface to another system that defines such a policy. By creating this module and inserting an appropriate entry into the acps.conf file, all access control requests made by applications that support the Access Control Policy Switch will automatically be routed to the module, without modifying the applications.
The service provider (module) interface is primarily composed of a well-defined acpm_checkauth() routine that each module must provide and a set of helper routines provided by the switch to encode and decode information into the opaque handle.
The single interface provided by each module is defined as follows:
int acpm_checkauth(acp_handle_t h, int argc, const char **argv);
The handle contains all of the request information. The argv argument contains an array of char * elements, each representing an argument specified in the ACPS configuration file entry for the module (see below). The module return values match exactly the API return values with the option of an additional value indicating that no access information is available for the given request (ACPS_NOINFO).
In order for the module to retrieve information from the handle about the access control request, the switch provides the following set of acpm* helper routines to extract the desired information, described in SYNOPSIS: acpm_getenvattrs(), acpm_getobj(), acpm_getobjattrs(), acpm_getop(), acpm_getopattrs(), acpm_getsubattrs(), acpm_getsubcreds(), acpm_getsubid().
Note that these routines are very similar to the API routines except that the multi-value attributes are returned as a linked list rather than requiring individual acpm_getX() routines. The practical reason for this is that it allows greater flexibility in manipulating the attribute data based on the needs of the module.
In the same way that an application can retrieve the credential requested by a module, (see acps_api(3)), the module has the following interface to encode this information into the handle:
int acpm_setreqcred(acp_handle_t h, char *cred);
A module would typically use this in the event that the application did not present the required credential. It is expected that the application will add the necessary information and repeat the call to acps_checkauth().
The values returned by the ACPS SPI (as well as the ACPS API) are defined in acps(3).
The following example illustrates a sample policy module that enforces the policy: