xref: /linux/net/netlink/af_netlink.h (revision cdd30ebb1b9f36159d66f088b61aee264e649d7a)
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 <net/sock.h>
8 
9 /* flags */
10 enum {
11 	NETLINK_F_KERNEL_SOCKET,
12 	NETLINK_F_RECV_PKTINFO,
13 	NETLINK_F_BROADCAST_SEND_ERROR,
14 	NETLINK_F_RECV_NO_ENOBUFS,
15 	NETLINK_F_LISTEN_ALL_NSID,
16 	NETLINK_F_CAP_ACK,
17 	NETLINK_F_EXT_ACK,
18 	NETLINK_F_STRICT_CHK,
19 };
20 
21 #define NLGRPSZ(x)	(ALIGN(x, sizeof(unsigned long) * 8) / 8)
22 #define NLGRPLONGS(x)	(NLGRPSZ(x)/sizeof(unsigned long))
23 
24 struct netlink_sock {
25 	/* struct sock has to be the first member of netlink_sock */
26 	struct sock		sk;
27 	unsigned long		flags;
28 	u32			portid;
29 	u32			dst_portid;
30 	u32			dst_group;
31 	u32			subscriptions;
32 	u32			ngroups;
33 	unsigned long		*groups;
34 	unsigned long		state;
35 	size_t			max_recvmsg_len;
36 	wait_queue_head_t	wait;
37 	bool			bound;
38 	bool			cb_running;
39 	int			dump_done_errno;
40 	struct netlink_callback	cb;
41 	struct mutex		nl_cb_mutex;
42 
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 	void			(*netlink_release)(struct sock *sk,
47 						   unsigned long *groups);
48 	struct module		*module;
49 
50 	struct rhash_head	node;
51 	struct rcu_head		rcu;
52 };
53 
54 static inline struct netlink_sock *nlk_sk(struct sock *sk)
55 {
56 	return container_of(sk, struct netlink_sock, sk);
57 }
58 
59 #define nlk_test_bit(nr, sk) test_bit(NETLINK_F_##nr, &nlk_sk(sk)->flags)
60 
61 struct netlink_table {
62 	struct rhashtable	hash;
63 	struct hlist_head	mc_list;
64 	struct listeners __rcu	*listeners;
65 	unsigned int		flags;
66 	unsigned int		groups;
67 	struct mutex		*cb_mutex;
68 	struct module		*module;
69 	int			(*bind)(struct net *net, int group);
70 	void			(*unbind)(struct net *net, int group);
71 	void                    (*release)(struct sock *sk,
72 					   unsigned long *groups);
73 	int			registered;
74 };
75 
76 extern struct netlink_table *nl_table;
77 extern rwlock_t nl_table_lock;
78 
79 #endif
80