summaryrefslogtreecommitdiffstats
path: root/include/net/genetlink.h
blob: b4c7c1cbcf400298d001da37162b2ca7c3b78d0a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
#ifndef __NET_GENERIC_NETLINK_H
#define __NET_GENERIC_NETLINK_H

#include <linux/genetlink.h>
#include <net/netlink.h>
#include <net/net_namespace.h>

/**
 * struct genl_multicast_group - generic netlink multicast group
 * @name: name of the multicast group, names are per-family
 * @id: multicast group ID, assigned by the core, to use with
 *      genlmsg_multicast().
 * @list: list entry for linking
 * @family: pointer to family, need not be set before registering
 */
struct genl_multicast_group {
	struct genl_family	*family;	/* private */
	struct list_head	list;		/* private */
	char			name[GENL_NAMSIZ];
	u32			id;
};

struct genl_ops;
struct genl_info;

/**
 * struct genl_family - generic netlink family
 * @id: protocol family idenfitier
 * @hdrsize: length of user specific header in bytes
 * @name: name of family
 * @version: protocol version
 * @maxattr: maximum number of attributes supported
 * @netnsok: set to true if the family can handle network
 *	namespaces and should be presented in all of them
 * @pre_doit: called before an operation's doit callback, it may
 *	do additional, common, filtering and return an error
 * @post_doit: called after an operation's doit callback, it may
 *	undo operations done by pre_doit, for example release locks
 * @attrbuf: buffer to store parsed attributes
 * @ops_list: list of all assigned operations
 * @family_list: family list
 * @mcast_groups: multicast groups list
 */
struct genl_family {
	unsigned int		id;
	unsigned int		hdrsize;
	char			name[GENL_NAMSIZ];
	unsigned int		version;
	unsigned int		maxattr;
	bool			netnsok;
	int			(*pre_doit)(struct genl_ops *ops,
					    struct sk_buff *skb,
					    struct genl_info *info);
	void			(*post_doit)(struct genl_ops *ops,
					     struct sk_buff *skb,
					     struct genl_info *info);
	struct nlattr **	attrbuf;	/* private */
	struct list_head	ops_list;	/* private */
	struct list_head	family_list;	/* private */
	struct list_head	mcast_groups;	/* private */
};

/**
 * struct genl_info - receiving information
 * @snd_seq: sending sequence number
 * @snd_pid: netlink pid of sender
 * @nlhdr: netlink message header
 * @genlhdr: generic netlink message header
 * @userhdr: user specific header
 * @attrs: netlink attributes
 * @_net: network namespace
 * @user_ptr: user pointers
 */
struct genl_info {
	u32			snd_seq;
	u32			snd_pid;
	struct nlmsghdr *	nlhdr;
	struct genlmsghdr *	genlhdr;
	void *			userhdr;
	struct nlattr **	attrs;
#ifdef CONFIG_NET_NS
	struct net *		_net;
#endif
	void *			user_ptr[2];
};

static inline struct net *genl_info_net(struct genl_info *info)
{
	return read_pnet(&info->_net);
}

static inline void genl_info_net_set(struct genl_info *info, struct net *net)
{
	write_pnet(&info->_net, net);
}

/**
 * struct genl_ops - generic netlink operations
 * @cmd: command identifier
 * @internal_flags: flags used by the family
 * @flags: flags
 * @policy: attribute validation policy
 * @doit: standard command callback
 * @dumpit: callback for dumpers
 * @done: completion callback for dumps
 * @ops_list: operations list
 */
struct genl_ops {
	u8			cmd;
	u8			internal_flags;
	unsigned int		flags;
	const struct nla_policy	*policy;
	int		       (*doit)(struct sk_buff *skb,
				       struct genl_info *info);
	int		       (*dumpit)(struct sk_buff *skb,
					 struct netlink_callback *cb);
	int		       (*done)(struct netlink_callback *cb);
	struct list_head	ops_list;
};

extern int genl_register_family(struct genl_family *family);
extern int genl_register_family_with_ops(struct genl_family *family,
	struct genl_ops *ops, size_t n_ops);
extern int genl_unregister_family(struct genl_family *family);
extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
extern int genl_register_mc_group(struct genl_family *family,
				  struct genl_multicast_group *grp);
extern void genl_unregister_mc_group(struct genl_family *family,
				     struct genl_multicast_group *grp);

/**
 * genlmsg_put - Add generic netlink header to netlink message
 * @skb: socket buffer holding the message
 * @pid: netlink pid the message is addressed to
 * @seq: sequence number (usually the one of the sender)
 * @family: generic netlink family
 * @flags netlink message flags
 * @cmd: generic netlink command
 *
 * Returns pointer to user specific header
 */
static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
				struct genl_family *family, int flags, u8 cmd)
{
	struct nlmsghdr *nlh;
	struct genlmsghdr *hdr;

	nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
			family->hdrsize, flags);
	if (nlh == NULL)
		return NULL;

	hdr = nlmsg_data(nlh);
	hdr->cmd = cmd;
	hdr->version = family->version;
	hdr->reserved = 0;

	return (char *) hdr + GENL_HDRLEN;
}

/**
 * genlmsg_put_reply - Add generic netlink header to a reply message
 * @skb: socket buffer holding the message
 * @info: receiver info
 * @family: generic netlink family
 * @flags: netlink message flags
 * @cmd: generic netlink command
 *
 * Returns pointer to user specific header
 */
static inline void *genlmsg_put_reply(struct sk_buff *skb,
				      struct genl_info *info,
				      struct genl_family *family,
				      int flags, u8 cmd)
{
	return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
			   flags, cmd);
}

/**
 * genlmsg_end - Finalize a generic netlink message
 * @skb: socket buffer the message is stored in
 * @hdr: user specific header
 */
static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
{
	return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
}

/**
 * genlmsg_cancel - Cancel construction of a generic netlink message
 * @skb: socket buffer the message is stored in
 * @hdr: generic netlink message header
 */
static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
{
	if (hdr)
		nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
}

/**
 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
 * @net: the net namespace
 * @skb: netlink message as socket buffer
 * @pid: own netlink pid to avoid sending to yourself
 * @group: multicast group id
 * @flags: allocation flags
 */
static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
					  u32 pid, unsigned int group, gfp_t flags)
{
	return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
}

/**
 * genlmsg_multicast - multicast a netlink message to the default netns
 * @skb: netlink message as socket buffer
 * @pid: own netlink pid to avoid sending to yourself
 * @group: multicast group id
 * @flags: allocation flags
 */
static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
				    unsigned int group, gfp_t flags)
{
	return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
}

/**
 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
 * @skb: netlink message as socket buffer
 * @pid: own netlink pid to avoid sending to yourself
 * @group: multicast group id
 * @flags: allocation flags
 *
 * This function must hold the RTNL or rcu_read_lock().
 */
int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
			    unsigned int group, gfp_t flags);

/**
 * genlmsg_unicast - unicast a netlink message
 * @skb: netlink message as socket buffer
 * @pid: netlink pid of the destination socket
 */
static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
{
	return nlmsg_unicast(net->genl_sock, skb, pid);
}

/**
 * genlmsg_reply - reply to a request
 * @skb: netlink message to be sent back
 * @info: receiver information
 */
static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
{
	return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
}

/**
 * gennlmsg_data - head of message payload
 * @gnlh: genetlink messsage header
 */
static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
{
	return ((unsigned char *) gnlh + GENL_HDRLEN);
}

/**
 * genlmsg_len - length of message payload
 * @gnlh: genetlink message header
 */
static inline int genlmsg_len(const struct genlmsghdr *gnlh)
{
	struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
							NLMSG_HDRLEN);
	return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
}

/**
 * genlmsg_msg_size - length of genetlink message not including padding
 * @payload: length of message payload
 */
static inline int genlmsg_msg_size(int payload)
{
	return GENL_HDRLEN + payload;
}

/**
 * genlmsg_total_size - length of genetlink message including padding
 * @payload: length of message payload
 */
static inline int genlmsg_total_size(int payload)
{
	return NLMSG_ALIGN(genlmsg_msg_size(payload));
}

/**
 * genlmsg_new - Allocate a new generic netlink message
 * @payload: size of the message payload
 * @flags: the type of memory to allocate.
 */
static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
{
	return nlmsg_new(genlmsg_total_size(payload), flags);
}


#endif	/* __NET_GENERIC_NETLINK_H */
OpenPOWER on IntegriCloud