Loading...
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/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_GENERIC_NETLINK_H
3#define __NET_GENERIC_NETLINK_H
4
5#include <linux/genetlink.h>
6#include <net/netlink.h>
7#include <net/net_namespace.h>
8
9#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
10
11/**
12 * struct genl_multicast_group - generic netlink multicast group
13 * @name: name of the multicast group, names are per-family
14 */
15struct genl_multicast_group {
16 char name[GENL_NAMSIZ];
17};
18
19struct genl_ops;
20struct genl_info;
21
22/**
23 * struct genl_family - generic netlink family
24 * @id: protocol family identifier (private)
25 * @hdrsize: length of user specific header in bytes
26 * @name: name of family
27 * @version: protocol version
28 * @maxattr: maximum number of attributes supported
29 * @policy: netlink policy
30 * @netnsok: set to true if the family can handle network
31 * namespaces and should be presented in all of them
32 * @parallel_ops: operations can be called in parallel and aren't
33 * synchronized by the core genetlink code
34 * @pre_doit: called before an operation's doit callback, it may
35 * do additional, common, filtering and return an error
36 * @post_doit: called after an operation's doit callback, it may
37 * undo operations done by pre_doit, for example release locks
38 * @mcgrps: multicast groups used by this family
39 * @n_mcgrps: number of multicast groups
40 * @mcgrp_offset: starting number of multicast group IDs in this family
41 * (private)
42 * @ops: the operations supported by this family
43 * @n_ops: number of operations supported by this family
44 */
45struct genl_family {
46 int id; /* private */
47 unsigned int hdrsize;
48 char name[GENL_NAMSIZ];
49 unsigned int version;
50 unsigned int maxattr;
51 bool netnsok;
52 bool parallel_ops;
53 const struct nla_policy *policy;
54 int (*pre_doit)(const struct genl_ops *ops,
55 struct sk_buff *skb,
56 struct genl_info *info);
57 void (*post_doit)(const struct genl_ops *ops,
58 struct sk_buff *skb,
59 struct genl_info *info);
60 const struct genl_ops * ops;
61 const struct genl_multicast_group *mcgrps;
62 unsigned int n_ops;
63 unsigned int n_mcgrps;
64 unsigned int mcgrp_offset; /* private */
65 struct module *module;
66};
67
68/**
69 * struct genl_info - receiving information
70 * @snd_seq: sending sequence number
71 * @snd_portid: netlink portid of sender
72 * @nlhdr: netlink message header
73 * @genlhdr: generic netlink message header
74 * @userhdr: user specific header
75 * @attrs: netlink attributes
76 * @_net: network namespace
77 * @user_ptr: user pointers
78 * @extack: extended ACK report struct
79 */
80struct genl_info {
81 u32 snd_seq;
82 u32 snd_portid;
83 struct nlmsghdr * nlhdr;
84 struct genlmsghdr * genlhdr;
85 void * userhdr;
86 struct nlattr ** attrs;
87 possible_net_t _net;
88 void * user_ptr[2];
89 struct netlink_ext_ack *extack;
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#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
103
104static inline int genl_err_attr(struct genl_info *info, int err,
105 const struct nlattr *attr)
106{
107 info->extack->bad_attr = attr;
108
109 return err;
110}
111
112enum genl_validate_flags {
113 GENL_DONT_VALIDATE_STRICT = BIT(0),
114 GENL_DONT_VALIDATE_DUMP = BIT(1),
115 GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
116};
117
118/**
119 * struct genl_info - info that is available during dumpit op call
120 * @family: generic netlink family - for internal genl code usage
121 * @ops: generic netlink ops - for internal genl code usage
122 * @attrs: netlink attributes
123 */
124struct genl_dumpit_info {
125 const struct genl_family *family;
126 const struct genl_ops *ops;
127 struct nlattr **attrs;
128};
129
130static inline const struct genl_dumpit_info *
131genl_dumpit_info(struct netlink_callback *cb)
132{
133 return cb->data;
134}
135
136/**
137 * struct genl_ops - generic netlink operations
138 * @cmd: command identifier
139 * @internal_flags: flags used by the family
140 * @flags: flags
141 * @validate: validation flags from enum genl_validate_flags
142 * @doit: standard command callback
143 * @start: start callback for dumps
144 * @dumpit: callback for dumpers
145 * @done: completion callback for dumps
146 */
147struct genl_ops {
148 int (*doit)(struct sk_buff *skb,
149 struct genl_info *info);
150 int (*start)(struct netlink_callback *cb);
151 int (*dumpit)(struct sk_buff *skb,
152 struct netlink_callback *cb);
153 int (*done)(struct netlink_callback *cb);
154 u8 cmd;
155 u8 internal_flags;
156 u8 flags;
157 u8 validate;
158};
159
160int genl_register_family(struct genl_family *family);
161int genl_unregister_family(const struct genl_family *family);
162void genl_notify(const struct genl_family *family, struct sk_buff *skb,
163 struct genl_info *info, u32 group, gfp_t flags);
164
165void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
166 const struct genl_family *family, int flags, u8 cmd);
167
168/**
169 * genlmsg_nlhdr - Obtain netlink header from user specified header
170 * @user_hdr: user header as returned from genlmsg_put()
171 *
172 * Returns pointer to netlink header.
173 */
174static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
175{
176 return (struct nlmsghdr *)((char *)user_hdr -
177 GENL_HDRLEN -
178 NLMSG_HDRLEN);
179}
180
181/**
182 * genlmsg_parse_deprecated - parse attributes of a genetlink message
183 * @nlh: netlink message header
184 * @family: genetlink message family
185 * @tb: destination array with maxtype+1 elements
186 * @maxtype: maximum attribute type to be expected
187 * @policy: validation policy
188 * @extack: extended ACK report struct
189 */
190static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
191 const struct genl_family *family,
192 struct nlattr *tb[], int maxtype,
193 const struct nla_policy *policy,
194 struct netlink_ext_ack *extack)
195{
196 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
197 policy, NL_VALIDATE_LIBERAL, extack);
198}
199
200/**
201 * genlmsg_parse - parse attributes of a genetlink message
202 * @nlh: netlink message header
203 * @family: genetlink message family
204 * @tb: destination array with maxtype+1 elements
205 * @maxtype: maximum attribute type to be expected
206 * @policy: validation policy
207 * @extack: extended ACK report struct
208 */
209static inline int genlmsg_parse(const struct nlmsghdr *nlh,
210 const struct genl_family *family,
211 struct nlattr *tb[], int maxtype,
212 const struct nla_policy *policy,
213 struct netlink_ext_ack *extack)
214{
215 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
216 policy, NL_VALIDATE_STRICT, extack);
217}
218
219/**
220 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
221 * @cb: netlink callback structure that stores the sequence number
222 * @user_hdr: user header as returned from genlmsg_put()
223 *
224 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
225 * simpler to use with generic netlink.
226 */
227static inline void genl_dump_check_consistent(struct netlink_callback *cb,
228 void *user_hdr)
229{
230 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
231}
232
233/**
234 * genlmsg_put_reply - Add generic netlink header to a reply message
235 * @skb: socket buffer holding the message
236 * @info: receiver info
237 * @family: generic netlink family
238 * @flags: netlink message flags
239 * @cmd: generic netlink command
240 *
241 * Returns pointer to user specific header
242 */
243static inline void *genlmsg_put_reply(struct sk_buff *skb,
244 struct genl_info *info,
245 const struct genl_family *family,
246 int flags, u8 cmd)
247{
248 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
249 flags, cmd);
250}
251
252/**
253 * genlmsg_end - Finalize a generic netlink message
254 * @skb: socket buffer the message is stored in
255 * @hdr: user specific header
256 */
257static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
258{
259 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
260}
261
262/**
263 * genlmsg_cancel - Cancel construction of a generic netlink message
264 * @skb: socket buffer the message is stored in
265 * @hdr: generic netlink message header
266 */
267static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
268{
269 if (hdr)
270 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
271}
272
273/**
274 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
275 * @family: the generic netlink family
276 * @net: the net namespace
277 * @skb: netlink message as socket buffer
278 * @portid: own netlink portid to avoid sending to yourself
279 * @group: offset of multicast group in groups array
280 * @flags: allocation flags
281 */
282static inline int genlmsg_multicast_netns(const struct genl_family *family,
283 struct net *net, struct sk_buff *skb,
284 u32 portid, unsigned int group, gfp_t flags)
285{
286 if (WARN_ON_ONCE(group >= family->n_mcgrps))
287 return -EINVAL;
288 group = family->mcgrp_offset + group;
289 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
290}
291
292/**
293 * genlmsg_multicast - multicast a netlink message to the default netns
294 * @family: the generic netlink family
295 * @skb: netlink message as socket buffer
296 * @portid: own netlink portid to avoid sending to yourself
297 * @group: offset of multicast group in groups array
298 * @flags: allocation flags
299 */
300static inline int genlmsg_multicast(const struct genl_family *family,
301 struct sk_buff *skb, u32 portid,
302 unsigned int group, gfp_t flags)
303{
304 return genlmsg_multicast_netns(family, &init_net, skb,
305 portid, group, flags);
306}
307
308/**
309 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
310 * @family: the generic netlink family
311 * @skb: netlink message as socket buffer
312 * @portid: own netlink portid to avoid sending to yourself
313 * @group: offset of multicast group in groups array
314 * @flags: allocation flags
315 *
316 * This function must hold the RTNL or rcu_read_lock().
317 */
318int genlmsg_multicast_allns(const struct genl_family *family,
319 struct sk_buff *skb, u32 portid,
320 unsigned int group, gfp_t flags);
321
322/**
323 * genlmsg_unicast - unicast a netlink message
324 * @skb: netlink message as socket buffer
325 * @portid: netlink portid of the destination socket
326 */
327static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
328{
329 return nlmsg_unicast(net->genl_sock, skb, portid);
330}
331
332/**
333 * genlmsg_reply - reply to a request
334 * @skb: netlink message to be sent back
335 * @info: receiver information
336 */
337static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
338{
339 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
340}
341
342/**
343 * gennlmsg_data - head of message payload
344 * @gnlh: genetlink message header
345 */
346static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
347{
348 return ((unsigned char *) gnlh + GENL_HDRLEN);
349}
350
351/**
352 * genlmsg_len - length of message payload
353 * @gnlh: genetlink message header
354 */
355static inline int genlmsg_len(const struct genlmsghdr *gnlh)
356{
357 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
358 NLMSG_HDRLEN);
359 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
360}
361
362/**
363 * genlmsg_msg_size - length of genetlink message not including padding
364 * @payload: length of message payload
365 */
366static inline int genlmsg_msg_size(int payload)
367{
368 return GENL_HDRLEN + payload;
369}
370
371/**
372 * genlmsg_total_size - length of genetlink message including padding
373 * @payload: length of message payload
374 */
375static inline int genlmsg_total_size(int payload)
376{
377 return NLMSG_ALIGN(genlmsg_msg_size(payload));
378}
379
380/**
381 * genlmsg_new - Allocate a new generic netlink message
382 * @payload: size of the message payload
383 * @flags: the type of memory to allocate.
384 */
385static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
386{
387 return nlmsg_new(genlmsg_total_size(payload), flags);
388}
389
390/**
391 * genl_set_err - report error to genetlink broadcast listeners
392 * @family: the generic netlink family
393 * @net: the network namespace to report the error to
394 * @portid: the PORTID of a process that we want to skip (if any)
395 * @group: the broadcast group that will notice the error
396 * (this is the offset of the multicast group in the groups array)
397 * @code: error code, must be negative (as usual in kernelspace)
398 *
399 * This function returns the number of broadcast listeners that have set the
400 * NETLINK_RECV_NO_ENOBUFS socket option.
401 */
402static inline int genl_set_err(const struct genl_family *family,
403 struct net *net, u32 portid,
404 u32 group, int code)
405{
406 if (WARN_ON_ONCE(group >= family->n_mcgrps))
407 return -EINVAL;
408 group = family->mcgrp_offset + group;
409 return netlink_set_err(net->genl_sock, portid, group, code);
410}
411
412static inline int genl_has_listeners(const struct genl_family *family,
413 struct net *net, unsigned int group)
414{
415 if (WARN_ON_ONCE(group >= family->n_mcgrps))
416 return -EINVAL;
417 group = family->mcgrp_offset + group;
418 return netlink_has_listeners(net->genl_sock, group);
419}
420#endif /* __NET_GENERIC_NETLINK_H */