792d1932e3
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>
69 lines
2 KiB
C
69 lines
2 KiB
C
/*
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* Network event notifiers
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*
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* Authors:
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* Tom Tucker <tom@opengridcomputing.com>
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* Steve Wise <swise@opengridcomputing.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Fixes:
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*/
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#include <linux/rtnetlink.h>
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#include <linux/notifier.h>
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static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain);
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/**
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* register_netevent_notifier - register a netevent notifier block
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* @nb: notifier
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*
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* Register a notifier to be called when a netevent occurs.
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* The notifier passed is linked into the kernel structures and must
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* not be reused until it has been unregistered. A negative errno code
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* is returned on a failure.
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*/
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int register_netevent_notifier(struct notifier_block *nb)
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{
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int err;
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err = atomic_notifier_chain_register(&netevent_notif_chain, nb);
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return err;
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}
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/**
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* netevent_unregister_notifier - unregister a netevent notifier block
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* @nb: notifier
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*
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* Unregister a notifier previously registered by
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* register_neigh_notifier(). The notifier is unlinked into the
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* kernel structures and may then be reused. A negative errno code
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* is returned on a failure.
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*/
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int unregister_netevent_notifier(struct notifier_block *nb)
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{
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return atomic_notifier_chain_unregister(&netevent_notif_chain, nb);
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}
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/**
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* call_netevent_notifiers - call all netevent notifier blocks
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* @val: value passed unmodified to notifier function
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* @v: pointer passed unmodified to notifier function
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*
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* Call all neighbour notifier blocks. Parameters and return value
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* are as for notifier_call_chain().
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*/
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int call_netevent_notifiers(unsigned long val, void *v)
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{
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return atomic_notifier_call_chain(&netevent_notif_chain, val, v);
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}
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EXPORT_SYMBOL_GPL(register_netevent_notifier);
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EXPORT_SYMBOL_GPL(unregister_netevent_notifier);
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EXPORT_SYMBOL_GPL(call_netevent_notifiers);
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