xref: /linux/net/netlink/af_netlink.h (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _AF_NETLINK_H
3 #define _AF_NETLINK_H
4 
5 #include <linux/rhashtable.h>
6 #include <linux/atomic.h>
7 #include <linux/workqueue.h>
8 #include <net/sock.h>
9 
10 /* flags */
11 #define NETLINK_F_KERNEL_SOCKET		0x1
12 #define NETLINK_F_RECV_PKTINFO		0x2
13 #define NETLINK_F_BROADCAST_SEND_ERROR	0x4
14 #define NETLINK_F_RECV_NO_ENOBUFS	0x8
15 #define NETLINK_F_LISTEN_ALL_NSID	0x10
16 #define NETLINK_F_CAP_ACK		0x20
17 #define NETLINK_F_EXT_ACK		0x40
18 
19 #define NLGRPSZ(x)	(ALIGN(x, sizeof(unsigned long) * 8) / 8)
20 #define NLGRPLONGS(x)	(NLGRPSZ(x)/sizeof(unsigned long))
21 
22 struct netlink_sock {
23 	/* struct sock has to be the first member of netlink_sock */
24 	struct sock		sk;
25 	u32			portid;
26 	u32			dst_portid;
27 	u32			dst_group;
28 	u32			flags;
29 	u32			subscriptions;
30 	u32			ngroups;
31 	unsigned long		*groups;
32 	unsigned long		state;
33 	size_t			max_recvmsg_len;
34 	wait_queue_head_t	wait;
35 	bool			bound;
36 	bool			cb_running;
37 	int			dump_done_errno;
38 	struct netlink_callback	cb;
39 	struct mutex		*cb_mutex;
40 	struct mutex		cb_def_mutex;
41 	void			(*netlink_rcv)(struct sk_buff *skb);
42 	int			(*netlink_bind)(struct net *net, int group);
43 	void			(*netlink_unbind)(struct net *net, int group);
44 	struct module		*module;
45 
46 	struct rhash_head	node;
47 	struct rcu_head		rcu;
48 	struct work_struct	work;
49 };
50 
51 static inline struct netlink_sock *nlk_sk(struct sock *sk)
52 {
53 	return container_of(sk, struct netlink_sock, sk);
54 }
55 
56 struct netlink_table {
57 	struct rhashtable	hash;
58 	struct hlist_head	mc_list;
59 	struct listeners __rcu	*listeners;
60 	unsigned int		flags;
61 	unsigned int		groups;
62 	struct mutex		*cb_mutex;
63 	struct module		*module;
64 	int			(*bind)(struct net *net, int group);
65 	void			(*unbind)(struct net *net, int group);
66 	bool			(*compare)(struct net *net, struct sock *sock);
67 	int			registered;
68 };
69 
70 extern struct netlink_table *nl_table;
71 extern rwlock_t nl_table_lock;
72 
73 #endif
74