1 #ifndef __LINUX_GENERIC_NETLINK_H
2 #define __LINUX_GENERIC_NETLINK_H
3 
4 #include <linux/types.h>
5 #include <linux/netlink.h>
6 
7 #define GENL_NAMSIZ	16	/* length of family name */
8 
9 #define GENL_MIN_ID	NLMSG_MIN_TYPE
10 #define GENL_MAX_ID	1023
11 
12 struct genlmsghdr {
13 	__u8	cmd;
14 	__u8	version;
15 	__u16	reserved;
16 };
17 
18 #define GENL_HDRLEN	NLMSG_ALIGN(sizeof(struct genlmsghdr))
19 
20 #define GENL_ADMIN_PERM		0x01
21 #define GENL_CMD_CAP_DO		0x02
22 #define GENL_CMD_CAP_DUMP	0x04
23 #define GENL_CMD_CAP_HASPOL	0x08
24 
25 /*
26  * List of reserved static generic netlink identifiers:
27  */
28 #define GENL_ID_GENERATE	0
29 #define GENL_ID_CTRL		NLMSG_MIN_TYPE
30 
31 /**************************************************************************
32  * Controller
33  **************************************************************************/
34 
35 enum {
36 	CTRL_CMD_UNSPEC,
37 	CTRL_CMD_NEWFAMILY,
38 	CTRL_CMD_DELFAMILY,
39 	CTRL_CMD_GETFAMILY,
40 	CTRL_CMD_NEWOPS,
41 	CTRL_CMD_DELOPS,
42 	CTRL_CMD_GETOPS,
43 	CTRL_CMD_NEWMCAST_GRP,
44 	CTRL_CMD_DELMCAST_GRP,
45 	CTRL_CMD_GETMCAST_GRP, /* unused */
46 	__CTRL_CMD_MAX,
47 };
48 
49 #define CTRL_CMD_MAX (__CTRL_CMD_MAX - 1)
50 
51 enum {
52 	CTRL_ATTR_UNSPEC,
53 	CTRL_ATTR_FAMILY_ID,
54 	CTRL_ATTR_FAMILY_NAME,
55 	CTRL_ATTR_VERSION,
56 	CTRL_ATTR_HDRSIZE,
57 	CTRL_ATTR_MAXATTR,
58 	CTRL_ATTR_OPS,
59 	CTRL_ATTR_MCAST_GROUPS,
60 	__CTRL_ATTR_MAX,
61 };
62 
63 #define CTRL_ATTR_MAX (__CTRL_ATTR_MAX - 1)
64 
65 enum {
66 	CTRL_ATTR_OP_UNSPEC,
67 	CTRL_ATTR_OP_ID,
68 	CTRL_ATTR_OP_FLAGS,
69 	__CTRL_ATTR_OP_MAX,
70 };
71 
72 #define CTRL_ATTR_OP_MAX (__CTRL_ATTR_OP_MAX - 1)
73 
74 enum {
75 	CTRL_ATTR_MCAST_GRP_UNSPEC,
76 	CTRL_ATTR_MCAST_GRP_NAME,
77 	CTRL_ATTR_MCAST_GRP_ID,
78 	__CTRL_ATTR_MCAST_GRP_MAX,
79 };
80 
81 #define CTRL_ATTR_MCAST_GRP_MAX (__CTRL_ATTR_MCAST_GRP_MAX - 1)
82 
83 #ifdef __KERNEL__
84 
85 /* All generic netlink requests are serialized by a global lock.  */
86 extern void genl_lock(void);
87 extern void genl_unlock(void);
88 #ifdef CONFIG_PROVE_LOCKING
89 extern int lockdep_genl_is_held(void);
90 #endif
91 
92 /**
93  * rcu_dereference_genl - rcu_dereference with debug checking
94  * @p: The pointer to read, prior to dereferencing
95  *
96  * Do an rcu_dereference(p), but check caller either holds rcu_read_lock()
97  * or genl mutex. Note : Please prefer genl_dereference() or rcu_dereference()
98  */
99 #define rcu_dereference_genl(p)					\
100 	rcu_dereference_check(p, lockdep_genl_is_held())
101 
102 /**
103  * genl_dereference - fetch RCU pointer when updates are prevented by genl mutex
104  * @p: The pointer to read, prior to dereferencing
105  *
106  * Return the value of the specified RCU-protected pointer, but omit
107  * both the smp_read_barrier_depends() and the ACCESS_ONCE(), because
108  * caller holds genl mutex.
109  */
110 #define genl_dereference(p)					\
111 	rcu_dereference_protected(p, lockdep_genl_is_held())
112 
113 #endif /* __KERNEL__ */
114 
115 #endif	/* __LINUX_GENERIC_NETLINK_H */
116