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

NAME

net_hook_register - add a hook to be called in event processing

SYNOPSIS

#include <sys/neti.h>

int net_hook_register(net_handle_t info, char *event, hook_t *hook);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

info
value returned from a successful call to
net_protocol_register().


name
unique name for this hook.


hook
pointer to a hook_t structure.

DESCRIPTION

The net_hook_register() function uses hooks that allow callbacks to
be registered with events that belong to a network protocol. A
successful call to net_hook_register() requires that a valid handle
for a network protocol be provided (the info parameter), along with a
unique name and a hook description that includes a reference to an
available event. No two hooks on the same netstack may share a name.


While it is possible to use the same hook_t structure with multiple
calls to net_hook_register(), it is not encouraged.


The hook_t structure passed in with this function is described by
hook_t(9S). The following describes how this structure is used.

h_func
Must be non-NULL and represent a function that
fits the specified interface.


h_name
Gives the hook a name that represents its
owner. No duplication of h_name among the
hooks present for an event is allowed.


h_flags
Currently unused and must be set to 0.


h_hint, h_hintvalue
Specify a hint to net_hook_register() on how
to insert this hook. If the hint cannot be
specified, then an error is returned.


h_arg;
May take any value that the consumer wishes to
have passed back when the hook is activated.

RETURN VALUES

If the net_hook_register() function succeeds, 0 is returned.
Otherwise, one of the following errors is returned:

ENOMEM
The system cannot allocate any more memory to support
registering this hook.


ENXIO
A hook cannot be found among the given family of events.


EEXIST
A hook with the given h_name already exists on that event.


ESRCH
A before or after dependency cannot be satisfied due to the
hook with


EBUSY
The h_hint field specifies a hint that cannot currently be
satisfied because it conflicts with another hook. An
example of this might be specifying HH_FIRST or HH_LAST
when another hook has already been registered with this
value.


ESHUTDOWN
The netstack corresponding to info is condemned or no
longer exists.

CONTEXT

The net_hook_register() function 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

net_hook_unregister(9F), hook_t(9S)

March 5, 2012 NET_HOOK_REGISTER(9F)