xref: /linux/net/netlink/af_netlink.h (revision 55f1b540d893da740a81200450014c45a8103f54)
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 enum {
12 	NETLINK_F_KERNEL_SOCKET,
13 	NETLINK_F_RECV_PKTINFO,
14 	NETLINK_F_BROADCAST_SEND_ERROR,
15 	NETLINK_F_RECV_NO_ENOBUFS,
16 	NETLINK_F_LISTEN_ALL_NSID,
17 	NETLINK_F_CAP_ACK,
18 	NETLINK_F_EXT_ACK,
19 	NETLINK_F_STRICT_CHK,
20 };
21 
22 #define NLGRPSZ(x)	(ALIGN(x, sizeof(unsigned long) * 8) / 8)
23 #define NLGRPLONGS(x)	(NLGRPSZ(x)/sizeof(unsigned long))
24 
25 struct netlink_sock {
26 	/* struct sock has to be the first member of netlink_sock */
27 	struct sock		sk;
28 	unsigned long		flags;
29 	u32			portid;
30 	u32			dst_portid;
31 	u32			dst_group;
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 	int			dump_done_errno;
41 	struct netlink_callback	cb;
42 	struct mutex		nl_cb_mutex;
43 
44 	void			(*netlink_rcv)(struct sk_buff *skb);
45 	int			(*netlink_bind)(struct net *net, int group);
46 	void			(*netlink_unbind)(struct net *net, int group);
47 	void			(*netlink_release)(struct sock *sk,
48 						   unsigned long *groups);
49 	struct module		*module;
50 
51 	struct rhash_head	node;
52 	struct rcu_head		rcu;
53 	struct work_struct	work;
54 };
55 
56 static inline struct netlink_sock *nlk_sk(struct sock *sk)
57 {
58 	return container_of(sk, struct netlink_sock, sk);
59 }
60 
61 #define nlk_test_bit(nr, sk) test_bit(NETLINK_F_##nr, &nlk_sk(sk)->flags)
62 
63 struct netlink_table {
64 	struct rhashtable	hash;
65 	struct hlist_head	mc_list;
66 	struct listeners __rcu	*listeners;
67 	unsigned int		flags;
68 	unsigned int		groups;
69 	struct mutex		*cb_mutex;
70 	struct module		*module;
71 	int			(*bind)(struct net *net, int group);
72 	void			(*unbind)(struct net *net, int group);
73 	void                    (*release)(struct sock *sk,
74 					   unsigned long *groups);
75 	int			registered;
76 };
77 
78 extern struct netlink_table *nl_table;
79 extern rwlock_t nl_table_lock;
80 
81 #endif
82