xref: /openbmc/linux/include/net/genetlink.h (revision 87c2ce3b)
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 module *		owner;
26 	struct nlattr **	attrbuf;	/* private */
27 	struct list_head	ops_list;	/* private */
28 	struct list_head	family_list;	/* private */
29 };
30 
31 #define GENL_ADMIN_PERM		0x01
32 
33 /**
34  * struct genl_info - receiving information
35  * @snd_seq: sending sequence number
36  * @snd_pid: netlink pid of sender
37  * @nlhdr: netlink message header
38  * @genlhdr: generic netlink message header
39  * @userhdr: user specific header
40  * @attrs: netlink attributes
41  */
42 struct genl_info
43 {
44 	u32			snd_seq;
45 	u32			snd_pid;
46 	struct nlmsghdr *	nlhdr;
47 	struct genlmsghdr *	genlhdr;
48 	void *			userhdr;
49 	struct nlattr **	attrs;
50 };
51 
52 /**
53  * struct genl_ops - generic netlink operations
54  * @cmd: command identifier
55  * @flags: flags
56  * @policy: attribute validation policy
57  * @doit: standard command callback
58  * @dumpit: callback for dumpers
59  * @ops_list: operations list
60  */
61 struct genl_ops
62 {
63 	u8			cmd;
64 	unsigned int		flags;
65 	struct nla_policy	*policy;
66 	int		       (*doit)(struct sk_buff *skb,
67 				       struct genl_info *info);
68 	int		       (*dumpit)(struct sk_buff *skb,
69 					 struct netlink_callback *cb);
70 	struct list_head	ops_list;
71 };
72 
73 extern int genl_register_family(struct genl_family *family);
74 extern int genl_unregister_family(struct genl_family *family);
75 extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
76 extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
77 
78 extern struct sock *genl_sock;
79 
80 /**
81  * genlmsg_put - Add generic netlink header to netlink message
82  * @skb: socket buffer holding the message
83  * @pid: netlink pid the message is addressed to
84  * @seq: sequence number (usually the one of the sender)
85  * @type: netlink message type
86  * @hdrlen: length of the user specific header
87  * @flags netlink message flags
88  * @cmd: generic netlink command
89  * @version: version
90  *
91  * Returns pointer to user specific header
92  */
93 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
94 				int type, int hdrlen, int flags,
95 				u8 cmd, u8 version)
96 {
97 	struct nlmsghdr *nlh;
98 	struct genlmsghdr *hdr;
99 
100 	nlh = nlmsg_put(skb, pid, seq, type, GENL_HDRLEN + hdrlen, flags);
101 	if (nlh == NULL)
102 		return NULL;
103 
104 	hdr = nlmsg_data(nlh);
105 	hdr->cmd = cmd;
106 	hdr->version = version;
107 	hdr->reserved = 0;
108 
109 	return (char *) hdr + GENL_HDRLEN;
110 }
111 
112 /**
113  * genlmsg_end - Finalize a generic netlink message
114  * @skb: socket buffer the message is stored in
115  * @hdr: user specific header
116  */
117 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
118 {
119 	return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
120 }
121 
122 /**
123  * genlmsg_cancel - Cancel construction of a generic netlink message
124  * @skb: socket buffer the message is stored in
125  * @hdr: generic netlink message header
126  */
127 static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr)
128 {
129 	return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
130 }
131 
132 /**
133  * genlmsg_multicast - multicast a netlink message
134  * @skb: netlink message as socket buffer
135  * @pid: own netlink pid to avoid sending to yourself
136  * @group: multicast group id
137  */
138 static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
139 				    unsigned int group)
140 {
141 	return nlmsg_multicast(genl_sock, skb, pid, group);
142 }
143 
144 /**
145  * genlmsg_unicast - unicast a netlink message
146  * @skb: netlink message as socket buffer
147  * @pid: netlink pid of the destination socket
148  */
149 static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
150 {
151 	return nlmsg_unicast(genl_sock, skb, pid);
152 }
153 
154 #endif	/* __NET_GENERIC_NETLINK_H */
155