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1#ifndef __NET_GENERIC_NETLINK_H
2#define __NET_GENERIC_NETLINK_H
3
4#include <linux/genetlink.h>
5#include <net/netlink.h>
6#include <net/net_namespace.h>
7
8#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
9
10/**
11 * struct genl_multicast_group - generic netlink multicast group
12 * @name: name of the multicast group, names are per-family
13 */
14struct genl_multicast_group {
15 char name[GENL_NAMSIZ];
16};
17
18struct genl_ops;
19struct genl_info;
20
21/**
22 * struct genl_family - generic netlink family
23 * @id: protocol family idenfitier
24 * @hdrsize: length of user specific header in bytes
25 * @name: name of family
26 * @version: protocol version
27 * @maxattr: maximum number of attributes supported
28 * @netnsok: set to true if the family can handle network
29 * namespaces and should be presented in all of them
30 * @parallel_ops: operations can be called in parallel and aren't
31 * synchronized by the core genetlink code
32 * @pre_doit: called before an operation's doit callback, it may
33 * do additional, common, filtering and return an error
34 * @post_doit: called after an operation's doit callback, it may
35 * undo operations done by pre_doit, for example release locks
36 * @mcast_bind: a socket bound to the given multicast group (which
37 * is given as the offset into the groups array)
38 * @mcast_unbind: a socket was unbound from the given multicast group.
39 * Note that unbind() will not be called symmetrically if the
40 * generic netlink family is removed while there are still open
41 * sockets.
42 * @attrbuf: buffer to store parsed attributes
43 * @family_list: family list
44 * @mcgrps: multicast groups used by this family (private)
45 * @n_mcgrps: number of multicast groups (private)
46 * @mcgrp_offset: starting number of multicast group IDs in this family
47 * @ops: the operations supported by this family (private)
48 * @n_ops: number of operations supported by this family (private)
49 */
50struct genl_family {
51 unsigned int id;
52 unsigned int hdrsize;
53 char name[GENL_NAMSIZ];
54 unsigned int version;
55 unsigned int maxattr;
56 bool netnsok;
57 bool parallel_ops;
58 int (*pre_doit)(const struct genl_ops *ops,
59 struct sk_buff *skb,
60 struct genl_info *info);
61 void (*post_doit)(const struct genl_ops *ops,
62 struct sk_buff *skb,
63 struct genl_info *info);
64 int (*mcast_bind)(struct net *net, int group);
65 void (*mcast_unbind)(struct net *net, int group);
66 struct nlattr ** attrbuf; /* private */
67 const struct genl_ops * ops; /* private */
68 const struct genl_multicast_group *mcgrps; /* private */
69 unsigned int n_ops; /* private */
70 unsigned int n_mcgrps; /* private */
71 unsigned int mcgrp_offset; /* private */
72 struct list_head family_list; /* private */
73 struct module *module;
74};
75
76/**
77 * struct genl_info - receiving information
78 * @snd_seq: sending sequence number
79 * @snd_portid: netlink portid of sender
80 * @nlhdr: netlink message header
81 * @genlhdr: generic netlink message header
82 * @userhdr: user specific header
83 * @attrs: netlink attributes
84 * @_net: network namespace
85 * @user_ptr: user pointers
86 */
87struct genl_info {
88 u32 snd_seq;
89 u32 snd_portid;
90 struct nlmsghdr * nlhdr;
91 struct genlmsghdr * genlhdr;
92 void * userhdr;
93 struct nlattr ** attrs;
94 possible_net_t _net;
95 void * user_ptr[2];
96};
97
98static inline struct net *genl_info_net(struct genl_info *info)
99{
100 return read_pnet(&info->_net);
101}
102
103static inline void genl_info_net_set(struct genl_info *info, struct net *net)
104{
105 write_pnet(&info->_net, net);
106}
107
108/**
109 * struct genl_ops - generic netlink operations
110 * @cmd: command identifier
111 * @internal_flags: flags used by the family
112 * @flags: flags
113 * @policy: attribute validation policy
114 * @doit: standard command callback
115 * @start: start callback for dumps
116 * @dumpit: callback for dumpers
117 * @done: completion callback for dumps
118 * @ops_list: operations list
119 */
120struct genl_ops {
121 const struct nla_policy *policy;
122 int (*doit)(struct sk_buff *skb,
123 struct genl_info *info);
124 int (*start)(struct netlink_callback *cb);
125 int (*dumpit)(struct sk_buff *skb,
126 struct netlink_callback *cb);
127 int (*done)(struct netlink_callback *cb);
128 u8 cmd;
129 u8 internal_flags;
130 u8 flags;
131};
132
133int __genl_register_family(struct genl_family *family);
134
135static inline int genl_register_family(struct genl_family *family)
136{
137 family->module = THIS_MODULE;
138 return __genl_register_family(family);
139}
140
141/**
142 * genl_register_family_with_ops - register a generic netlink family with ops
143 * @family: generic netlink family
144 * @ops: operations to be registered
145 * @n_ops: number of elements to register
146 *
147 * Registers the specified family and operations from the specified table.
148 * Only one family may be registered with the same family name or identifier.
149 *
150 * The family id may equal GENL_ID_GENERATE causing an unique id to
151 * be automatically generated and assigned.
152 *
153 * Either a doit or dumpit callback must be specified for every registered
154 * operation or the function will fail. Only one operation structure per
155 * command identifier may be registered.
156 *
157 * See include/net/genetlink.h for more documenation on the operations
158 * structure.
159 *
160 * Return 0 on success or a negative error code.
161 */
162static inline int
163_genl_register_family_with_ops_grps(struct genl_family *family,
164 const struct genl_ops *ops, size_t n_ops,
165 const struct genl_multicast_group *mcgrps,
166 size_t n_mcgrps)
167{
168 family->module = THIS_MODULE;
169 family->ops = ops;
170 family->n_ops = n_ops;
171 family->mcgrps = mcgrps;
172 family->n_mcgrps = n_mcgrps;
173 return __genl_register_family(family);
174}
175
176#define genl_register_family_with_ops(family, ops) \
177 _genl_register_family_with_ops_grps((family), \
178 (ops), ARRAY_SIZE(ops), \
179 NULL, 0)
180#define genl_register_family_with_ops_groups(family, ops, grps) \
181 _genl_register_family_with_ops_grps((family), \
182 (ops), ARRAY_SIZE(ops), \
183 (grps), ARRAY_SIZE(grps))
184
185int genl_unregister_family(struct genl_family *family);
186void genl_notify(struct genl_family *family, struct sk_buff *skb,
187 struct genl_info *info, u32 group, gfp_t flags);
188
189void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
190 struct genl_family *family, int flags, u8 cmd);
191
192/**
193 * genlmsg_nlhdr - Obtain netlink header from user specified header
194 * @user_hdr: user header as returned from genlmsg_put()
195 * @family: generic netlink family
196 *
197 * Returns pointer to netlink header.
198 */
199static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
200 struct genl_family *family)
201{
202 return (struct nlmsghdr *)((char *)user_hdr -
203 family->hdrsize -
204 GENL_HDRLEN -
205 NLMSG_HDRLEN);
206}
207
208/**
209 * genlmsg_parse - parse attributes of a genetlink message
210 * @nlh: netlink message header
211 * @family: genetlink message family
212 * @tb: destination array with maxtype+1 elements
213 * @maxtype: maximum attribute type to be expected
214 * @policy: validation policy
215 * */
216static inline int genlmsg_parse(const struct nlmsghdr *nlh,
217 const struct genl_family *family,
218 struct nlattr *tb[], int maxtype,
219 const struct nla_policy *policy)
220{
221 return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
222 policy);
223}
224
225/**
226 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
227 * @cb: netlink callback structure that stores the sequence number
228 * @user_hdr: user header as returned from genlmsg_put()
229 * @family: generic netlink family
230 *
231 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
232 * simpler to use with generic netlink.
233 */
234static inline void genl_dump_check_consistent(struct netlink_callback *cb,
235 void *user_hdr,
236 struct genl_family *family)
237{
238 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
239}
240
241/**
242 * genlmsg_put_reply - Add generic netlink header to a reply message
243 * @skb: socket buffer holding the message
244 * @info: receiver info
245 * @family: generic netlink family
246 * @flags: netlink message flags
247 * @cmd: generic netlink command
248 *
249 * Returns pointer to user specific header
250 */
251static inline void *genlmsg_put_reply(struct sk_buff *skb,
252 struct genl_info *info,
253 struct genl_family *family,
254 int flags, u8 cmd)
255{
256 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
257 flags, cmd);
258}
259
260/**
261 * genlmsg_end - Finalize a generic netlink message
262 * @skb: socket buffer the message is stored in
263 * @hdr: user specific header
264 */
265static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
266{
267 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
268}
269
270/**
271 * genlmsg_cancel - Cancel construction of a generic netlink message
272 * @skb: socket buffer the message is stored in
273 * @hdr: generic netlink message header
274 */
275static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
276{
277 if (hdr)
278 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
279}
280
281/**
282 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
283 * @family: the generic netlink family
284 * @net: the net namespace
285 * @skb: netlink message as socket buffer
286 * @portid: own netlink portid to avoid sending to yourself
287 * @group: offset of multicast group in groups array
288 * @flags: allocation flags
289 */
290static inline int genlmsg_multicast_netns(struct genl_family *family,
291 struct net *net, struct sk_buff *skb,
292 u32 portid, unsigned int group, gfp_t flags)
293{
294 if (WARN_ON_ONCE(group >= family->n_mcgrps))
295 return -EINVAL;
296 group = family->mcgrp_offset + group;
297 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
298}
299
300/**
301 * genlmsg_multicast - multicast a netlink message to the default netns
302 * @family: the generic netlink family
303 * @skb: netlink message as socket buffer
304 * @portid: own netlink portid to avoid sending to yourself
305 * @group: offset of multicast group in groups array
306 * @flags: allocation flags
307 */
308static inline int genlmsg_multicast(struct genl_family *family,
309 struct sk_buff *skb, u32 portid,
310 unsigned int group, gfp_t flags)
311{
312 return genlmsg_multicast_netns(family, &init_net, skb,
313 portid, group, flags);
314}
315
316/**
317 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
318 * @family: the generic netlink family
319 * @skb: netlink message as socket buffer
320 * @portid: own netlink portid to avoid sending to yourself
321 * @group: offset of multicast group in groups array
322 * @flags: allocation flags
323 *
324 * This function must hold the RTNL or rcu_read_lock().
325 */
326int genlmsg_multicast_allns(struct genl_family *family,
327 struct sk_buff *skb, u32 portid,
328 unsigned int group, gfp_t flags);
329
330/**
331 * genlmsg_unicast - unicast a netlink message
332 * @skb: netlink message as socket buffer
333 * @portid: netlink portid of the destination socket
334 */
335static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
336{
337 return nlmsg_unicast(net->genl_sock, skb, portid);
338}
339
340/**
341 * genlmsg_reply - reply to a request
342 * @skb: netlink message to be sent back
343 * @info: receiver information
344 */
345static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
346{
347 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
348}
349
350/**
351 * gennlmsg_data - head of message payload
352 * @gnlh: genetlink message header
353 */
354static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
355{
356 return ((unsigned char *) gnlh + GENL_HDRLEN);
357}
358
359/**
360 * genlmsg_len - length of message payload
361 * @gnlh: genetlink message header
362 */
363static inline int genlmsg_len(const struct genlmsghdr *gnlh)
364{
365 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
366 NLMSG_HDRLEN);
367 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
368}
369
370/**
371 * genlmsg_msg_size - length of genetlink message not including padding
372 * @payload: length of message payload
373 */
374static inline int genlmsg_msg_size(int payload)
375{
376 return GENL_HDRLEN + payload;
377}
378
379/**
380 * genlmsg_total_size - length of genetlink message including padding
381 * @payload: length of message payload
382 */
383static inline int genlmsg_total_size(int payload)
384{
385 return NLMSG_ALIGN(genlmsg_msg_size(payload));
386}
387
388/**
389 * genlmsg_new - Allocate a new generic netlink message
390 * @payload: size of the message payload
391 * @flags: the type of memory to allocate.
392 */
393static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
394{
395 return nlmsg_new(genlmsg_total_size(payload), flags);
396}
397
398/**
399 * genl_set_err - report error to genetlink broadcast listeners
400 * @family: the generic netlink family
401 * @net: the network namespace to report the error to
402 * @portid: the PORTID of a process that we want to skip (if any)
403 * @group: the broadcast group that will notice the error
404 * (this is the offset of the multicast group in the groups array)
405 * @code: error code, must be negative (as usual in kernelspace)
406 *
407 * This function returns the number of broadcast listeners that have set the
408 * NETLINK_RECV_NO_ENOBUFS socket option.
409 */
410static inline int genl_set_err(struct genl_family *family, struct net *net,
411 u32 portid, u32 group, int code)
412{
413 if (WARN_ON_ONCE(group >= family->n_mcgrps))
414 return -EINVAL;
415 group = family->mcgrp_offset + group;
416 return netlink_set_err(net->genl_sock, portid, group, code);
417}
418
419static inline int genl_has_listeners(struct genl_family *family,
420 struct net *net, unsigned int group)
421{
422 if (WARN_ON_ONCE(group >= family->n_mcgrps))
423 return -EINVAL;
424 group = family->mcgrp_offset + group;
425 return netlink_has_listeners(net->genl_sock, group);
426}
427#endif /* __NET_GENERIC_NETLINK_H */
1#ifndef __NET_GENERIC_NETLINK_H
2#define __NET_GENERIC_NETLINK_H
3
4#include <linux/genetlink.h>
5#include <net/netlink.h>
6#include <net/net_namespace.h>
7
8#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
9
10/**
11 * struct genl_multicast_group - generic netlink multicast group
12 * @name: name of the multicast group, names are per-family
13 */
14struct genl_multicast_group {
15 char name[GENL_NAMSIZ];
16};
17
18struct genl_ops;
19struct genl_info;
20
21/**
22 * struct genl_family - generic netlink family
23 * @id: protocol family idenfitier
24 * @hdrsize: length of user specific header in bytes
25 * @name: name of family
26 * @version: protocol version
27 * @maxattr: maximum number of attributes supported
28 * @netnsok: set to true if the family can handle network
29 * namespaces and should be presented in all of them
30 * @pre_doit: called before an operation's doit callback, it may
31 * do additional, common, filtering and return an error
32 * @post_doit: called after an operation's doit callback, it may
33 * undo operations done by pre_doit, for example release locks
34 * @attrbuf: buffer to store parsed attributes
35 * @family_list: family list
36 * @mcgrps: multicast groups used by this family (private)
37 * @n_mcgrps: number of multicast groups (private)
38 * @mcgrp_offset: starting number of multicast group IDs in this family
39 * @ops: the operations supported by this family (private)
40 * @n_ops: number of operations supported by this family (private)
41 */
42struct genl_family {
43 unsigned int id;
44 unsigned int hdrsize;
45 char name[GENL_NAMSIZ];
46 unsigned int version;
47 unsigned int maxattr;
48 bool netnsok;
49 bool parallel_ops;
50 int (*pre_doit)(const struct genl_ops *ops,
51 struct sk_buff *skb,
52 struct genl_info *info);
53 void (*post_doit)(const struct genl_ops *ops,
54 struct sk_buff *skb,
55 struct genl_info *info);
56 struct nlattr ** attrbuf; /* private */
57 const struct genl_ops * ops; /* private */
58 const struct genl_multicast_group *mcgrps; /* private */
59 unsigned int n_ops; /* private */
60 unsigned int n_mcgrps; /* private */
61 unsigned int mcgrp_offset; /* private */
62 struct list_head family_list; /* private */
63 struct module *module;
64};
65
66/**
67 * struct genl_info - receiving information
68 * @snd_seq: sending sequence number
69 * @snd_portid: netlink portid of sender
70 * @nlhdr: netlink message header
71 * @genlhdr: generic netlink message header
72 * @userhdr: user specific header
73 * @attrs: netlink attributes
74 * @_net: network namespace
75 * @user_ptr: user pointers
76 * @dst_sk: destination socket
77 */
78struct genl_info {
79 u32 snd_seq;
80 u32 snd_portid;
81 struct nlmsghdr * nlhdr;
82 struct genlmsghdr * genlhdr;
83 void * userhdr;
84 struct nlattr ** attrs;
85#ifdef CONFIG_NET_NS
86 struct net * _net;
87#endif
88 void * user_ptr[2];
89 struct sock * dst_sk;
90};
91
92static inline struct net *genl_info_net(struct genl_info *info)
93{
94 return read_pnet(&info->_net);
95}
96
97static inline void genl_info_net_set(struct genl_info *info, struct net *net)
98{
99 write_pnet(&info->_net, net);
100}
101
102/**
103 * struct genl_ops - generic netlink operations
104 * @cmd: command identifier
105 * @internal_flags: flags used by the family
106 * @flags: flags
107 * @policy: attribute validation policy
108 * @doit: standard command callback
109 * @dumpit: callback for dumpers
110 * @done: completion callback for dumps
111 * @ops_list: operations list
112 */
113struct genl_ops {
114 const struct nla_policy *policy;
115 int (*doit)(struct sk_buff *skb,
116 struct genl_info *info);
117 int (*dumpit)(struct sk_buff *skb,
118 struct netlink_callback *cb);
119 int (*done)(struct netlink_callback *cb);
120 u8 cmd;
121 u8 internal_flags;
122 u8 flags;
123};
124
125int __genl_register_family(struct genl_family *family);
126
127static inline int genl_register_family(struct genl_family *family)
128{
129 family->module = THIS_MODULE;
130 return __genl_register_family(family);
131}
132
133/**
134 * genl_register_family_with_ops - register a generic netlink family with ops
135 * @family: generic netlink family
136 * @ops: operations to be registered
137 * @n_ops: number of elements to register
138 *
139 * Registers the specified family and operations from the specified table.
140 * Only one family may be registered with the same family name or identifier.
141 *
142 * The family id may equal GENL_ID_GENERATE causing an unique id to
143 * be automatically generated and assigned.
144 *
145 * Either a doit or dumpit callback must be specified for every registered
146 * operation or the function will fail. Only one operation structure per
147 * command identifier may be registered.
148 *
149 * See include/net/genetlink.h for more documenation on the operations
150 * structure.
151 *
152 * Return 0 on success or a negative error code.
153 */
154static inline int
155_genl_register_family_with_ops_grps(struct genl_family *family,
156 const struct genl_ops *ops, size_t n_ops,
157 const struct genl_multicast_group *mcgrps,
158 size_t n_mcgrps)
159{
160 family->module = THIS_MODULE;
161 family->ops = ops;
162 family->n_ops = n_ops;
163 family->mcgrps = mcgrps;
164 family->n_mcgrps = n_mcgrps;
165 return __genl_register_family(family);
166}
167
168#define genl_register_family_with_ops(family, ops) \
169 _genl_register_family_with_ops_grps((family), \
170 (ops), ARRAY_SIZE(ops), \
171 NULL, 0)
172#define genl_register_family_with_ops_groups(family, ops, grps) \
173 _genl_register_family_with_ops_grps((family), \
174 (ops), ARRAY_SIZE(ops), \
175 (grps), ARRAY_SIZE(grps))
176
177int genl_unregister_family(struct genl_family *family);
178void genl_notify(struct genl_family *family,
179 struct sk_buff *skb, struct net *net, u32 portid,
180 u32 group, struct nlmsghdr *nlh, gfp_t flags);
181
182struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
183 gfp_t flags);
184void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
185 struct genl_family *family, int flags, u8 cmd);
186
187/**
188 * genlmsg_nlhdr - Obtain netlink header from user specified header
189 * @user_hdr: user header as returned from genlmsg_put()
190 * @family: generic netlink family
191 *
192 * Returns pointer to netlink header.
193 */
194static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
195 struct genl_family *family)
196{
197 return (struct nlmsghdr *)((char *)user_hdr -
198 family->hdrsize -
199 GENL_HDRLEN -
200 NLMSG_HDRLEN);
201}
202
203/**
204 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
205 * @cb: netlink callback structure that stores the sequence number
206 * @user_hdr: user header as returned from genlmsg_put()
207 * @family: generic netlink family
208 *
209 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
210 * simpler to use with generic netlink.
211 */
212static inline void genl_dump_check_consistent(struct netlink_callback *cb,
213 void *user_hdr,
214 struct genl_family *family)
215{
216 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
217}
218
219/**
220 * genlmsg_put_reply - Add generic netlink header to a reply message
221 * @skb: socket buffer holding the message
222 * @info: receiver info
223 * @family: generic netlink family
224 * @flags: netlink message flags
225 * @cmd: generic netlink command
226 *
227 * Returns pointer to user specific header
228 */
229static inline void *genlmsg_put_reply(struct sk_buff *skb,
230 struct genl_info *info,
231 struct genl_family *family,
232 int flags, u8 cmd)
233{
234 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
235 flags, cmd);
236}
237
238/**
239 * genlmsg_end - Finalize a generic netlink message
240 * @skb: socket buffer the message is stored in
241 * @hdr: user specific header
242 */
243static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
244{
245 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
246}
247
248/**
249 * genlmsg_cancel - Cancel construction of a generic netlink message
250 * @skb: socket buffer the message is stored in
251 * @hdr: generic netlink message header
252 */
253static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
254{
255 if (hdr)
256 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
257}
258
259/**
260 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
261 * @family: the generic netlink family
262 * @net: the net namespace
263 * @skb: netlink message as socket buffer
264 * @portid: own netlink portid to avoid sending to yourself
265 * @group: offset of multicast group in groups array
266 * @flags: allocation flags
267 */
268static inline int genlmsg_multicast_netns(struct genl_family *family,
269 struct net *net, struct sk_buff *skb,
270 u32 portid, unsigned int group, gfp_t flags)
271{
272 if (WARN_ON_ONCE(group >= family->n_mcgrps))
273 return -EINVAL;
274 group = family->mcgrp_offset + group;
275 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
276}
277
278/**
279 * genlmsg_multicast - multicast a netlink message to the default netns
280 * @family: the generic netlink family
281 * @skb: netlink message as socket buffer
282 * @portid: own netlink portid to avoid sending to yourself
283 * @group: offset of multicast group in groups array
284 * @flags: allocation flags
285 */
286static inline int genlmsg_multicast(struct genl_family *family,
287 struct sk_buff *skb, u32 portid,
288 unsigned int group, gfp_t flags)
289{
290 return genlmsg_multicast_netns(family, &init_net, skb,
291 portid, group, flags);
292}
293
294/**
295 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
296 * @family: the generic netlink family
297 * @skb: netlink message as socket buffer
298 * @portid: own netlink portid to avoid sending to yourself
299 * @group: offset of multicast group in groups array
300 * @flags: allocation flags
301 *
302 * This function must hold the RTNL or rcu_read_lock().
303 */
304int genlmsg_multicast_allns(struct genl_family *family,
305 struct sk_buff *skb, u32 portid,
306 unsigned int group, gfp_t flags);
307
308/**
309 * genlmsg_unicast - unicast a netlink message
310 * @skb: netlink message as socket buffer
311 * @portid: netlink portid of the destination socket
312 */
313static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
314{
315 return nlmsg_unicast(net->genl_sock, skb, portid);
316}
317
318/**
319 * genlmsg_reply - reply to a request
320 * @skb: netlink message to be sent back
321 * @info: receiver information
322 */
323static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
324{
325 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
326}
327
328/**
329 * gennlmsg_data - head of message payload
330 * @gnlh: genetlink message header
331 */
332static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
333{
334 return ((unsigned char *) gnlh + GENL_HDRLEN);
335}
336
337/**
338 * genlmsg_len - length of message payload
339 * @gnlh: genetlink message header
340 */
341static inline int genlmsg_len(const struct genlmsghdr *gnlh)
342{
343 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
344 NLMSG_HDRLEN);
345 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
346}
347
348/**
349 * genlmsg_msg_size - length of genetlink message not including padding
350 * @payload: length of message payload
351 */
352static inline int genlmsg_msg_size(int payload)
353{
354 return GENL_HDRLEN + payload;
355}
356
357/**
358 * genlmsg_total_size - length of genetlink message including padding
359 * @payload: length of message payload
360 */
361static inline int genlmsg_total_size(int payload)
362{
363 return NLMSG_ALIGN(genlmsg_msg_size(payload));
364}
365
366/**
367 * genlmsg_new - Allocate a new generic netlink message
368 * @payload: size of the message payload
369 * @flags: the type of memory to allocate.
370 */
371static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
372{
373 return nlmsg_new(genlmsg_total_size(payload), flags);
374}
375
376/**
377 * genl_set_err - report error to genetlink broadcast listeners
378 * @family: the generic netlink family
379 * @net: the network namespace to report the error to
380 * @portid: the PORTID of a process that we want to skip (if any)
381 * @group: the broadcast group that will notice the error
382 * (this is the offset of the multicast group in the groups array)
383 * @code: error code, must be negative (as usual in kernelspace)
384 *
385 * This function returns the number of broadcast listeners that have set the
386 * NETLINK_RECV_NO_ENOBUFS socket option.
387 */
388static inline int genl_set_err(struct genl_family *family, struct net *net,
389 u32 portid, u32 group, int code)
390{
391 if (WARN_ON_ONCE(group >= family->n_mcgrps))
392 return -EINVAL;
393 group = family->mcgrp_offset + group;
394 return netlink_set_err(net->genl_sock, portid, group, code);
395}
396
397#endif /* __NET_GENERIC_NETLINK_H */