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		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>
		
	
			
		
			
				
	
	
		
			70 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			70 lines
		
	
	
		
			2.0 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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| 
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| #include <linux/rtnetlink.h>
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| #include <linux/notifier.h>
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| 
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| static ATOMIC_NOTIFIER_HEAD(netevent_notif_chain);
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| 
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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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| 
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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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| /**
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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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| 
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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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| /**
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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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| 
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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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| 
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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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