xref: /openbmc/linux/net/netlink/af_netlink.h (revision 0f4630f3)
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			bound;
39 	bool			cb_running;
40 	struct netlink_callback	cb;
41 	struct mutex		*cb_mutex;
42 	struct mutex		cb_def_mutex;
43 	void			(*netlink_rcv)(struct sk_buff *skb);
44 	int			(*netlink_bind)(struct net *net, int group);
45 	void			(*netlink_unbind)(struct net *net, int group);
46 	struct module		*module;
47 #ifdef CONFIG_NETLINK_MMAP
48 	struct mutex		pg_vec_lock;
49 	struct netlink_ring	rx_ring;
50 	struct netlink_ring	tx_ring;
51 	atomic_t		mapped;
52 #endif /* CONFIG_NETLINK_MMAP */
53 
54 	struct rhash_head	node;
55 	struct rcu_head		rcu;
56 };
57 
58 static inline struct netlink_sock *nlk_sk(struct sock *sk)
59 {
60 	return container_of(sk, struct netlink_sock, sk);
61 }
62 
63 static inline bool netlink_skb_is_mmaped(const struct sk_buff *skb)
64 {
65 #ifdef CONFIG_NETLINK_MMAP
66 	return NETLINK_CB(skb).flags & NETLINK_SKB_MMAPED;
67 #else
68 	return false;
69 #endif /* CONFIG_NETLINK_MMAP */
70 }
71 
72 struct netlink_table {
73 	struct rhashtable	hash;
74 	struct hlist_head	mc_list;
75 	struct listeners __rcu	*listeners;
76 	unsigned int		flags;
77 	unsigned int		groups;
78 	struct mutex		*cb_mutex;
79 	struct module		*module;
80 	int			(*bind)(struct net *net, int group);
81 	void			(*unbind)(struct net *net, int group);
82 	bool			(*compare)(struct net *net, struct sock *sock);
83 	int			registered;
84 };
85 
86 extern struct netlink_table *nl_table;
87 extern rwlock_t nl_table_lock;
88 
89 #endif
90