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 */
18struct 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/**
31 * struct genl_info - receiving information
32 * @snd_seq: sending sequence number
33 * @snd_pid: netlink pid of sender
34 * @nlhdr: netlink message header
35 * @genlhdr: generic netlink message header
36 * @userhdr: user specific header
37 * @attrs: netlink attributes
38 */
39struct genl_info
40{
41	u32			snd_seq;
42	u32			snd_pid;
43	struct nlmsghdr *	nlhdr;
44	struct genlmsghdr *	genlhdr;
45	void *			userhdr;
46	struct nlattr **	attrs;
47};
48
49/**
50 * struct genl_ops - generic netlink operations
51 * @cmd: command identifier
52 * @flags: flags
53 * @policy: attribute validation policy
54 * @doit: standard command callback
55 * @dumpit: callback for dumpers
56 * @done: completion callback for dumps
57 * @ops_list: operations list
58 */
59struct genl_ops
60{
61	u8			cmd;
62	unsigned int		flags;
63	const struct nla_policy	*policy;
64	int		       (*doit)(struct sk_buff *skb,
65				       struct genl_info *info);
66	int		       (*dumpit)(struct sk_buff *skb,
67					 struct netlink_callback *cb);
68	int		       (*done)(struct netlink_callback *cb);
69	struct list_head	ops_list;
70};
71
72extern int genl_register_family(struct genl_family *family);
73extern int genl_unregister_family(struct genl_family *family);
74extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
75extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
76
77extern 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 * @family: generic netlink family
85 * @flags netlink message flags
86 * @cmd: generic netlink command
87 *
88 * Returns pointer to user specific header
89 */
90static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
91				struct genl_family *family, int flags, u8 cmd)
92{
93	struct nlmsghdr *nlh;
94	struct genlmsghdr *hdr;
95
96	nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
97			family->hdrsize, flags);
98	if (nlh == NULL)
99		return NULL;
100
101	hdr = nlmsg_data(nlh);
102	hdr->cmd = cmd;
103	hdr->version = family->version;
104	hdr->reserved = 0;
105
106	return (char *) hdr + GENL_HDRLEN;
107}
108
109/**
110 * genlmsg_put_reply - Add generic netlink header to a reply message
111 * @skb: socket buffer holding the message
112 * @info: receiver info
113 * @family: generic netlink family
114 * @flags: netlink message flags
115 * @cmd: generic netlink command
116 *
117 * Returns pointer to user specific header
118 */
119static inline void *genlmsg_put_reply(struct sk_buff *skb,
120				      struct genl_info *info,
121				      struct genl_family *family,
122				      int flags, u8 cmd)
123{
124	return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
125			   flags, cmd);
126}
127
128/**
129 * genlmsg_end - Finalize a generic netlink message
130 * @skb: socket buffer the message is stored in
131 * @hdr: user specific header
132 */
133static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
134{
135	return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
136}
137
138/**
139 * genlmsg_cancel - Cancel construction of a generic netlink message
140 * @skb: socket buffer the message is stored in
141 * @hdr: generic netlink message header
142 */
143static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr)
144{
145	return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
146}
147
148/**
149 * genlmsg_multicast - multicast a netlink message
150 * @skb: netlink message as socket buffer
151 * @pid: own netlink pid to avoid sending to yourself
152 * @group: multicast group id
153 * @flags: allocation flags
154 */
155static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
156				    unsigned int group, gfp_t flags)
157{
158	return nlmsg_multicast(genl_sock, skb, pid, group, flags);
159}
160
161/**
162 * genlmsg_unicast - unicast a netlink message
163 * @skb: netlink message as socket buffer
164 * @pid: netlink pid of the destination socket
165 */
166static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid)
167{
168	return nlmsg_unicast(genl_sock, skb, pid);
169}
170
171/**
172 * genlmsg_reply - reply to a request
173 * @skb: netlink message to be sent back
174 * @info: receiver information
175 */
176static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
177{
178	return genlmsg_unicast(skb, info->snd_pid);
179}
180
181/**
182 * gennlmsg_data - head of message payload
183 * @gnlh: genetlink messsage header
184 */
185static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
186{
187	return ((unsigned char *) gnlh + GENL_HDRLEN);
188}
189
190/**
191 * genlmsg_len - length of message payload
192 * @gnlh: genetlink message header
193 */
194static inline int genlmsg_len(const struct genlmsghdr *gnlh)
195{
196	struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
197							NLMSG_HDRLEN);
198	return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
199}
200
201/**
202 * genlmsg_msg_size - length of genetlink message not including padding
203 * @payload: length of message payload
204 */
205static inline int genlmsg_msg_size(int payload)
206{
207	return GENL_HDRLEN + payload;
208}
209
210/**
211 * genlmsg_total_size - length of genetlink message including padding
212 * @payload: length of message payload
213 */
214static inline int genlmsg_total_size(int payload)
215{
216	return NLMSG_ALIGN(genlmsg_msg_size(payload));
217}
218
219/**
220 * genlmsg_new - Allocate a new generic netlink message
221 * @payload: size of the message payload
222 * @flags: the type of memory to allocate.
223 */
224static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
225{
226	return nlmsg_new(genlmsg_total_size(payload), flags);
227}
228
229
230#endif	/* __NET_GENERIC_NETLINK_H */
231