xref: /linux/include/net/genetlink.h (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 #ifndef __NET_GENERIC_NETLINK_H
2 #define __NET_GENERIC_NETLINK_H
3 
4 #include <linux/genetlink.h>
5 #include <net/netlink.h>
6 
7 /**
8  * struct genl_family - generic netlink family
9  * @id: protocol family idenfitier
10  * @hdrsize: length of user specific header in bytes
11  * @name: name of family
12  * @version: protocol version
13  * @maxattr: maximum number of attributes supported
14  * @attrbuf: buffer to store parsed attributes
15  * @ops_list: list of all assigned operations
16  * @family_list: family list
17  */
18 struct genl_family
19 {
20 	unsigned int		id;
21 	unsigned int		hdrsize;
22 	char			name[GENL_NAMSIZ];
23 	unsigned int		version;
24 	unsigned int		maxattr;
25 	struct nlattr **	attrbuf;	/* private */
26 	struct list_head	ops_list;	/* private */
27 	struct list_head	family_list;	/* private */
28 };
29 
30 #define GENL_ADMIN_PERM		0x01
31 
32 /**
33  * struct genl_info - receiving information
34  * @snd_seq: sending sequence number
35  * @snd_pid: netlink pid of sender
36  * @nlhdr: netlink message header
37  * @genlhdr: generic netlink message header
38  * @userhdr: user specific header
39  * @attrs: netlink attributes
40  */
41 struct genl_info
42 {
43 	u32			snd_seq;
44 	u32			snd_pid;
45 	struct nlmsghdr *	nlhdr;
46 	struct genlmsghdr *	genlhdr;
47 	void *			userhdr;
48 	struct nlattr **	attrs;
49 };
50 
51 /**
52  * struct genl_ops - generic netlink operations
53  * @cmd: command identifier
54  * @flags: flags
55  * @policy: attribute validation policy
56  * @doit: standard command callback
57  * @dumpit: callback for dumpers
58  * @ops_list: operations list
59  */
60 struct genl_ops
61 {
62 	u8			cmd;
63 	unsigned int		flags;
64 	struct nla_policy	*policy;
65 	int		       (*doit)(struct sk_buff *skb,
66 				       struct genl_info *info);
67 	int		       (*dumpit)(struct sk_buff *skb,
68 					 struct netlink_callback *cb);
69 	struct list_head	ops_list;
70 };
71 
72 extern int genl_register_family(struct genl_family *family);
73 extern int genl_unregister_family(struct genl_family *family);
74 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
75 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
76 
77 extern struct sock *genl_sock;
78 
79 /**
80  * genlmsg_put - Add generic netlink header to netlink message
81  * @skb: socket buffer holding the message
82  * @pid: netlink pid the message is addressed to
83  * @seq: sequence number (usually the one of the sender)
84  * @type: netlink message type
85  * @hdrlen: length of the user specific header
86  * @flags netlink message flags
87  * @cmd: generic netlink command
88  * @version: version
89  *
90  * Returns pointer to user specific header
91  */
92 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
93 				int type, int hdrlen, int flags,
94 				u8 cmd, u8 version)
95 {
96 	struct nlmsghdr *nlh;
97 	struct genlmsghdr *hdr;
98 
99 	nlh = nlmsg_put(skb, pid, seq, type, GENL_HDRLEN + hdrlen, flags);
100 	if (nlh == NULL)
101 		return NULL;
102 
103 	hdr = nlmsg_data(nlh);
104 	hdr->cmd = cmd;
105 	hdr->version = version;
106 	hdr->reserved = 0;
107 
108 	return (char *) hdr + GENL_HDRLEN;
109 }
110 
111 /**
112  * genlmsg_end - Finalize a generic netlink message
113  * @skb: socket buffer the message is stored in
114  * @hdr: user specific header
115  */
116 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
117 {
118 	return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
119 }
120 
121 /**
122  * genlmsg_cancel - Cancel construction of a generic netlink message
123  * @skb: socket buffer the message is stored in
124  * @hdr: generic netlink message header
125  */
126 static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr)
127 {
128 	return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
129 }
130 
131 /**
132  * genlmsg_multicast - multicast a netlink message
133  * @skb: netlink message as socket buffer
134  * @pid: own netlink pid to avoid sending to yourself
135  * @group: multicast group id
136  */
137 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
138 				    unsigned int group)
139 {
140 	return nlmsg_multicast(genl_sock, skb, pid, group);
141 }
142 
143 /**
144  * genlmsg_unicast - unicast a netlink message
145  * @skb: netlink message as socket buffer
146  * @pid: netlink pid of the destination socket
147  */
148 static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
149 {
150 	return nlmsg_unicast(genl_sock, skb, pid);
151 }
152 
153 #endif	/* __NET_GENERIC_NETLINK_H */
154