Eric Lee / smarc-fsl-linux-kernel

Commit 792d1932e319ff8ba01361e7d151b1794c55c31f

Authored by Tom Tucker 19 years ago

Committed by David S. Miller 19 years ago

Exists in master and in 39 other branches

[NET]: Network Event Notifier Mechanism.

This patch uses notifier blocks to implement a network event
notifier mechanism.

Clients register their callback function by calling
register_netevent_notifier() like this:

static struct notifier_block nb = {
        .notifier_call = my_callback_func
};

...

register_netevent_notifier(&nb);

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 2 changed files with 102 additions and 0 deletions Side-by-side Diff

include/net/netevent.h
net/core/netevent.c

include/net/netevent.h

Diff comments View file @ 792d193

	1	+#ifndef _NET_EVENT_H
	2	+#define _NET_EVENT_H
	3	+
	4	+/*
	5	+ * Generic netevent notifiers
	6	+ *
	7	+ * Authors:
	8	+ * Tom Tucker <tom@opengridcomputing.com>
	9	+ * Steve Wise <swise@opengridcomputing.com>
	10	+ *
	11	+ * Changes:
	12	+ */
	13	+#ifdef __KERNEL__
	14	+
	15	+#include <net/dst.h>
	16	+
	17	+struct netevent_redirect {
	18	+ struct dst_entry *old;
	19	+ struct dst_entry *new;
	20	+};
	21	+
	22	+enum netevent_notif_type {
	23	+ NETEVENT_NEIGH_UPDATE = 1, /* arg is struct neighbour ptr */
	24	+ NETEVENT_PMTU_UPDATE, /* arg is struct dst_entry ptr */
	25	+ NETEVENT_REDIRECT, /* arg is struct netevent_redirect ptr */
	26	+};
	27	+
	28	+extern int register_netevent_notifier(struct notifier_block *nb);
	29	+extern int unregister_netevent_notifier(struct notifier_block *nb);
	30	+extern int call_netevent_notifiers(unsigned long val, void *v);
	31	+
	32	+#endif
	33	+#endif

net/core/netevent.c

Diff comments View file @ 792d193

	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	+
	19	+static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain);
	20	+
	21	+/**
	22	+ * register_netevent_notifier - register a netevent notifier block
	23	+ * @nb: notifier
	24	+ *
	25	+ * Register a notifier to be called when a netevent occurs.
	26	+ * The notifier passed is linked into the kernel structures and must
	27	+ * not be reused until it has been unregistered. A negative errno code
	28	+ * is returned on a failure.
	29	+ */
	30	+int register_netevent_notifier(struct notifier_block *nb)
	31	+{
	32	+ int err;
	33	+
	34	+ err = atomic_notifier_chain_register(&netevent_notif_chain, nb);
	35	+ return err;
	36	+}
	37	+
	38	+/**
	39	+ * netevent_unregister_notifier - unregister a netevent notifier block
	40	+ * @nb: notifier
	41	+ *
	42	+ * Unregister a notifier previously registered by
	43	+ * register_neigh_notifier(). The notifier is unlinked into the
	44	+ * kernel structures and may then be reused. A negative errno code
	45	+ * is returned on a failure.
	46	+ */
	47	+
	48	+int unregister_netevent_notifier(struct notifier_block *nb)
	49	+{
	50	+ return atomic_notifier_chain_unregister(&netevent_notif_chain, nb);
	51	+}
	52	+
	53	+/**
	54	+ * call_netevent_notifiers - call all netevent notifier blocks
	55	+ * @val: value passed unmodified to notifier function
	56	+ * @v: pointer passed unmodified to notifier function
	57	+ *
	58	+ * Call all neighbour notifier blocks. Parameters and return value
	59	+ * are as for notifier_call_chain().
	60	+ */
	61	+
	62	+int call_netevent_notifiers(unsigned long val, void *v)
	63	+{
	64	+ return atomic_notifier_call_chain(&netevent_notif_chain, val, v);
	65	+}
	66	+
	67	+EXPORT_SYMBOL_GPL(register_netevent_notifier);
	68	+EXPORT_SYMBOL_GPL(unregister_netevent_notifier);
	69	+EXPORT_SYMBOL_GPL(call_netevent_notifiers);