From 792d1932e319ff8ba01361e7d151b1794c55c31f Mon Sep 17 00:00:00 2001 From: Tom Tucker Date: Sun, 30 Jul 2006 20:43:26 -0700 Subject: [PATCH] [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 Signed-off-by: Steve Wise Signed-off-by: David S. Miller --- include/net/netevent.h | 33 ++++++++++++++++++++ net/core/netevent.c | 69 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 102 insertions(+) create mode 100644 include/net/netevent.h create mode 100644 net/core/netevent.c diff --git a/include/net/netevent.h b/include/net/netevent.h new file mode 100644 index 000000000000..e5d216241423 --- /dev/null +++ b/include/net/netevent.h @@ -0,0 +1,33 @@ +#ifndef _NET_EVENT_H +#define _NET_EVENT_H + +/* + * Generic netevent notifiers + * + * Authors: + * Tom Tucker + * Steve Wise + * + * Changes: + */ +#ifdef __KERNEL__ + +#include + +struct netevent_redirect { + struct dst_entry *old; + struct dst_entry *new; +}; + +enum netevent_notif_type { + NETEVENT_NEIGH_UPDATE = 1, /* arg is struct neighbour ptr */ + NETEVENT_PMTU_UPDATE, /* arg is struct dst_entry ptr */ + NETEVENT_REDIRECT, /* arg is struct netevent_redirect ptr */ +}; + +extern int register_netevent_notifier(struct notifier_block *nb); +extern int unregister_netevent_notifier(struct notifier_block *nb); +extern int call_netevent_notifiers(unsigned long val, void *v); + +#endif +#endif diff --git a/net/core/netevent.c b/net/core/netevent.c new file mode 100644 index 000000000000..35d02c38554e --- /dev/null +++ b/net/core/netevent.c @@ -0,0 +1,69 @@ +/* + * Network event notifiers + * + * Authors: + * Tom Tucker + * Steve Wise + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Fixes: + */ + +#include +#include + +static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain); + +/** + * register_netevent_notifier - register a netevent notifier block + * @nb: notifier + * + * Register a notifier to be called when a netevent occurs. + * The notifier passed is linked into the kernel structures and must + * not be reused until it has been unregistered. A negative errno code + * is returned on a failure. + */ +int register_netevent_notifier(struct notifier_block *nb) +{ + int err; + + err = atomic_notifier_chain_register(&netevent_notif_chain, nb); + return err; +} + +/** + * netevent_unregister_notifier - unregister a netevent notifier block + * @nb: notifier + * + * Unregister a notifier previously registered by + * register_neigh_notifier(). The notifier is unlinked into the + * kernel structures and may then be reused. A negative errno code + * is returned on a failure. + */ + +int unregister_netevent_notifier(struct notifier_block *nb) +{ + return atomic_notifier_chain_unregister(&netevent_notif_chain, nb); +} + +/** + * call_netevent_notifiers - call all netevent notifier blocks + * @val: value passed unmodified to notifier function + * @v: pointer passed unmodified to notifier function + * + * Call all neighbour notifier blocks. Parameters and return value + * are as for notifier_call_chain(). + */ + +int call_netevent_notifiers(unsigned long val, void *v) +{ + return atomic_notifier_call_chain(&netevent_notif_chain, val, v); +} + +EXPORT_SYMBOL_GPL(register_netevent_notifier); +EXPORT_SYMBOL_GPL(unregister_netevent_notifier); +EXPORT_SYMBOL_GPL(call_netevent_notifiers); -- 2.20.1