xref: /linux/net/netlink/af_netlink.h (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 #ifndef _AF_NETLINK_H
2 #define _AF_NETLINK_H
3 
4 #include <linux/rhashtable.h>
5 #include <linux/atomic.h>
6 #include <net/sock.h>
7 
8 #define NLGRPSZ(x)	(ALIGN(x, sizeof(unsigned long) * 8) / 8)
9 #define NLGRPLONGS(x)	(NLGRPSZ(x)/sizeof(unsigned long))
10 
11 struct netlink_ring {
12 	void			**pg_vec;
13 	unsigned int		head;
14 	unsigned int		frames_per_block;
15 	unsigned int		frame_size;
16 	unsigned int		frame_max;
17 
18 	unsigned int		pg_vec_order;
19 	unsigned int		pg_vec_pages;
20 	unsigned int		pg_vec_len;
21 
22 	atomic_t		pending;
23 };
24 
25 struct netlink_sock {
26 	/* struct sock has to be the first member of netlink_sock */
27 	struct sock		sk;
28 	u32			portid;
29 	u32			dst_portid;
30 	u32			dst_group;
31 	u32			flags;
32 	u32			subscriptions;
33 	u32			ngroups;
34 	unsigned long		*groups;
35 	unsigned long		state;
36 	size_t			max_recvmsg_len;
37 	wait_queue_head_t	wait;
38 	bool			cb_running;
39 	struct netlink_callback	cb;
40 	struct mutex		*cb_mutex;
41 	struct mutex		cb_def_mutex;
42 	void			(*netlink_rcv)(struct sk_buff *skb);
43 	int			(*netlink_bind)(struct net *net, int group);
44 	void			(*netlink_unbind)(struct net *net, int group);
45 	struct module		*module;
46 #ifdef CONFIG_NETLINK_MMAP
47 	struct mutex		pg_vec_lock;
48 	struct netlink_ring	rx_ring;
49 	struct netlink_ring	tx_ring;
50 	atomic_t		mapped;
51 #endif /* CONFIG_NETLINK_MMAP */
52 
53 	struct rhash_head	node;
54 	struct rcu_head		rcu;
55 };
56 
57 static inline struct netlink_sock *nlk_sk(struct sock *sk)
58 {
59 	return container_of(sk, struct netlink_sock, sk);
60 }
61 
62 struct netlink_table {
63 	struct rhashtable	hash;
64 	struct hlist_head	mc_list;
65 	struct listeners __rcu	*listeners;
66 	unsigned int		flags;
67 	unsigned int		groups;
68 	struct mutex		*cb_mutex;
69 	struct module		*module;
70 	int			(*bind)(struct net *net, int group);
71 	void			(*unbind)(struct net *net, int group);
72 	bool			(*compare)(struct net *net, struct sock *sock);
73 	int			registered;
74 };
75 
76 extern struct netlink_table *nl_table;
77 extern rwlock_t nl_table_lock;
78 
79 #endif
80