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NET_EVENT_NOTIFY_REGISTER 9F "Oct 30, 2008"
NAME
net_event_notify_register, net_event_notify_unregister - add/delete a function to be called for changes to a event
SYNOPSIS
#include <sys/hook.h>
#include <sys/neti.h>

int net_event_notify_register(net_handle_t family, char
 *event, hook_notify_fn_t *callback, void *arg);

int net_event_notify_unregister(net_handle_t family, char
 *event, hook_notify_fn_t *callback);

typedef int (* hook_notify_fn_t)(hook_notify_cmd_t command,
 void *arg, const char *name1, const char *name2, const char
 *name3);
INTERFACE LEVEL
illumos DDI specific (illumos DDI).
PARAMETERS
family

value returned from a successful call to net_protocol_lookup().

callback

function to call when a change occurs.

event

name of the event for which notification of change is desired.

arg

pointer to pass into the callback() function when a change occurs.

DESCRIPTION
The net_event_notify_register() function registers a function represented by the pointer callback to be called when there is a change to the event represented by family. The types of changes for which notifications are available for is currently limited to the addition and removal of hooks.

The net_event_notify_unregister() function indicates that there is no longer any desire to receive notification of changes to the event through function calls to the specified callback.

The name of a hook should be considered a private interface unless otherwise specified. The hook names used by IPFilter in illumos are a public, but uncommitted, interface.

Multiple callback functions may be registered through this interface. The same set of parameters is passed to each callback function. The memory referenced through the pointers passed to the callback should be treated as pointing to read-only memory. Changing this data is strictly prohibited.

The function that is called when the event occurs must not block any other events.

The arguments passed through to the callback are as follows (the command is either HN_REGISTER or HN_UNREGISTER): name1

is the name of the protocol.

name2

is the name of the event

name3

is the name of the hook being added/removed

RETURN VALUES
If these functions succeed, 0 is returned. Otherwise, the following error is returned: EEXIST

the given callback function is already registered.

CONTEXT
These functions may be called from user or kernel context.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Committed
SEE ALSO
attributes (7), net_hook_register (9F), net_hook_unregister (9F), net_protocol_lookup (9F)