blob: ff4982ab84b60ecfbcc764d460a15f7bbb87a4da (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
/*
* generic net pointers
*/
#ifndef __NET_GENERIC_H__
#define __NET_GENERIC_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. Either set pernet_operations->size (to have the code allocate and
* free a private structure pointed to from struct net ) or
* call net_assign_generic() to put the private data on the struct
* net (most preferably this should be done in the ->init callback
* of the ops registered);
* 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 {
unsigned int len;
struct rcu_head rcu;
void *ptr[0];
};
static inline void *net_generic(struct net *net, int id)
{
struct net_generic *ng;
void *ptr;
rcu_read_lock();
ng = rcu_dereference(net->gen);
BUG_ON(id == 0 || id > ng->len);
ptr = ng->ptr[id - 1];
rcu_read_unlock();
return ptr;
}
extern int net_assign_generic(struct net *net, int id, void *data);
#endif
|
