xref: /linux/net/core/netevent.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  *	Network event notifiers
3  *
4  *	Authors:
5  *      Tom Tucker             <tom@opengridcomputing.com>
6  *      Steve Wise             <swise@opengridcomputing.com>
7  *
8  *	This program is free software; you can redistribute it and/or
9  *      modify it under the terms of the GNU General Public License
10  *      as published by the Free Software Foundation; either version
11  *      2 of the License, or (at your option) any later version.
12  *
13  *	Fixes:
14  */
15 
16 #include <linux/rtnetlink.h>
17 #include <linux/notifier.h>
18 #include <net/netevent.h>
19 
20 static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain);
21 
22 /**
23  *	register_netevent_notifier - register a netevent notifier block
24  *	@nb: notifier
25  *
26  *	Register a notifier to be called when a netevent occurs.
27  *	The notifier passed is linked into the kernel structures and must
28  *	not be reused until it has been unregistered. A negative errno code
29  *	is returned on a failure.
30  */
31 int register_netevent_notifier(struct notifier_block *nb)
32 {
33 	int err;
34 
35 	err = atomic_notifier_chain_register(&netevent_notif_chain, nb);
36 	return err;
37 }
38 EXPORT_SYMBOL_GPL(register_netevent_notifier);
39 
40 /**
41  *	netevent_unregister_notifier - unregister a netevent notifier block
42  *	@nb: notifier
43  *
44  *	Unregister a notifier previously registered by
45  *	register_neigh_notifier(). The notifier is unlinked into the
46  *	kernel structures and may then be reused. A negative errno code
47  *	is returned on a failure.
48  */
49 
50 int unregister_netevent_notifier(struct notifier_block *nb)
51 {
52 	return atomic_notifier_chain_unregister(&netevent_notif_chain, nb);
53 }
54 EXPORT_SYMBOL_GPL(unregister_netevent_notifier);
55 
56 /**
57  *	call_netevent_notifiers - call all netevent notifier blocks
58  *      @val: value passed unmodified to notifier function
59  *      @v:   pointer passed unmodified to notifier function
60  *
61  *	Call all neighbour notifier blocks.  Parameters and return value
62  *	are as for notifier_call_chain().
63  */
64 
65 int call_netevent_notifiers(unsigned long val, void *v)
66 {
67 	return atomic_notifier_call_chain(&netevent_notif_chain, val, v);
68 }
69 EXPORT_SYMBOL_GPL(call_netevent_notifiers);
70