illumos: manual page: mac

MAC_ALLOC(9F) Kernel Functions for Drivers MAC_ALLOC(9F)

NAME

mac_alloc, mac_free - allocate and free mac registration structures

SYNOPSIS

#include <sys/mac_provider.h>

mac_register_t *
mac_alloc(uint_t mac_version);

void
mac_free(mac_register_t *mregp);

INTERFACE LEVEL

illumos DDI specific

PARAMETERS

mac_version An integer corresponding to the version of the MAC interface
that the device driver was built against.

mregp A pointer to an allocated mac_register_t structure that was
obtained from calling the mac_alloc() function.

DESCRIPTION

The mac_alloc() and mac_free() routines are used to allocate and free the
structures used to register a device driver with mac(9E). The device
driver should call mac_alloc() with the value of MAC_VERSION to indicate
the current version of the MAC framework that it supports. The device
driver will be returned an instance of a mac_register(9S) structure which
it can then use to call mac_register(9F). For more information on the
order of events, see the Initializing MAC Support section of mac(9E).

When the driver is done with the mac_register(9S) structure, it must call
the mac_free() function to release any memory associated with the handle.

After the driver has called mac_register(9F) during its attach(9E) entry
point, the mac_register(9S) structure is no longer needed and can be freed.

CONTEXT

The mac_alloc() and mac_free() routines are generally called from the
context of a device driver's attach(9E) entry point; however, they may be
called from both user and kernel context.

RETURN VALUES

Upon successful completion, the mac_alloc() function will return a pointer
to an allocated mac_register_t structure that can be filled in by the
driver. Otherwise, NULL is returned to indicate that the structure could
not be allocated. The most common cause for this is that the value of
mac_version is not supported by the kernel.