[mirror_ubuntu-jammy-kernel.git] / include / net / netns / generic.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * generic net pointers
 */

#ifndef __NET_GENERIC_H__
#define __NET_GENERIC_H__

#include <linux/bug.h>
#include <linux/rcupdate.h>

/*
 * Generic net pointers are to be used by modules to put some private
 * stuff on the struct net without explicit struct net modification
 *
 * The rules are simple:
 * 1. set pernet_operations->id.  After register_pernet_device you
 *    will have the id of your private pointer.
 * 2. set pernet_operations->size to have the code allocate and free
 *    a private structure pointed to from struct net.
 * 3. do not change this pointer while the net is alive;
 * 4. do not try to have any private reference on the net_generic object.
 *
 * After accomplishing all of the above, the private pointer can be
 * accessed with the net_generic() call.
 */

struct net_generic {
	union {
		struct {
			unsigned int len;
			struct rcu_head rcu;
		} s;

		void *ptr[0];
	};
};

static inline void *net_generic(const struct net *net, unsigned int id)
{
	struct net_generic *ng;
	void *ptr;

	rcu_read_lock();
	ng = rcu_dereference(net->gen);
	ptr = ng->ptr[id];
	rcu_read_unlock();

	return ptr;
}
#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
dec827d1 PE	2	/*
	3	* generic net pointers
	4	*/
	5
	6	#ifndef __NET_GENERIC_H__
	7	#define __NET_GENERIC_H__
	8
187f1882	9	#include <linux/bug.h>
dec827d1 PE	10	#include <linux/rcupdate.h>
	11
	12	/*
	13	* Generic net pointers are to be used by modules to put some private
	14	* stuff on the struct net without explicit struct net modification
	15	*
	16	* The rules are simple:
65c0cfaf EB	17	* 1. set pernet_operations->id. After register_pernet_device you
65c0cfaf EB	18	* will have the id of your private pointer.
05fceb4a JP	19	* 2. set pernet_operations->size to have the code allocate and free
05fceb4a JP	20	* a private structure pointed to from struct net.
dec827d1 PE	21	* 3. do not change this pointer while the net is alive;
	22	* 4. do not try to have any private reference on the net_generic object.
	23	*
	24	* After accomplishing all of the above, the private pointer can be
	25	* accessed with the net_generic() call.
	26	*/
	27
	28	struct net_generic {
6af2d5ff AD	29	union {
	30	struct {
	31	unsigned int len;
	32	struct rcu_head rcu;
	33	} s;
	34
	35	void *ptr[0];
	36	};
dec827d1 PE	37	};
dec827d1 PE	38
c7d03a00	39	static inline void net_generic(const struct net net, unsigned int id)
dec827d1 PE	40	{
	41	struct net_generic *ng;
	42	void *ptr;
	43
	44	rcu_read_lock();
	45	ng = rcu_dereference(net->gen);
6af2d5ff	46	ptr = ng->ptr[id];
dec827d1 PE	47	rcu_read_unlock();
	48
	49	return ptr;
	50	}
dec827d1	51	#endif