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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 u8 flags;
18};
19
20struct genl_ops;
21struct genl_info;
22
23/**
24 * struct genl_family - generic netlink family
25 * @id: protocol family identifier (private)
26 * @hdrsize: length of user specific header in bytes
27 * @name: name of family
28 * @version: protocol version
29 * @maxattr: maximum number of attributes supported
30 * @policy: netlink policy
31 * @netnsok: set to true if the family can handle network
32 * namespaces and should be presented in all of them
33 * @parallel_ops: operations can be called in parallel and aren't
34 * synchronized by the core genetlink code
35 * @pre_doit: called before an operation's doit callback, it may
36 * do additional, common, filtering and return an error
37 * @post_doit: called after an operation's doit callback, it may
38 * undo operations done by pre_doit, for example release locks
39 * @mcgrps: multicast groups used by this family
40 * @n_mcgrps: number of multicast groups
41 * @mcgrp_offset: starting number of multicast group IDs in this family
42 * (private)
43 * @ops: the operations supported by this family
44 * @n_ops: number of operations supported by this family
45 * @small_ops: the small-struct operations supported by this family
46 * @n_small_ops: number of small-struct operations supported by this family
47 */
48struct genl_family {
49 int id; /* private */
50 unsigned int hdrsize;
51 char name[GENL_NAMSIZ];
52 unsigned int version;
53 unsigned int maxattr;
54 unsigned int mcgrp_offset; /* private */
55 u8 netnsok:1;
56 u8 parallel_ops:1;
57 u8 n_ops;
58 u8 n_small_ops;
59 u8 n_mcgrps;
60 const struct nla_policy *policy;
61 int (*pre_doit)(const struct genl_ops *ops,
62 struct sk_buff *skb,
63 struct genl_info *info);
64 void (*post_doit)(const struct genl_ops *ops,
65 struct sk_buff *skb,
66 struct genl_info *info);
67 const struct genl_ops * ops;
68 const struct genl_small_ops *small_ops;
69 const struct genl_multicast_group *mcgrps;
70 struct module *module;
71};
72
73/**
74 * struct genl_info - receiving information
75 * @snd_seq: sending sequence number
76 * @snd_portid: netlink portid of sender
77 * @nlhdr: netlink message header
78 * @genlhdr: generic netlink message header
79 * @userhdr: user specific header
80 * @attrs: netlink attributes
81 * @_net: network namespace
82 * @user_ptr: user pointers
83 * @extack: extended ACK report struct
84 */
85struct genl_info {
86 u32 snd_seq;
87 u32 snd_portid;
88 struct nlmsghdr * nlhdr;
89 struct genlmsghdr * genlhdr;
90 void * userhdr;
91 struct nlattr ** attrs;
92 possible_net_t _net;
93 void * user_ptr[2];
94 struct netlink_ext_ack *extack;
95};
96
97static inline struct net *genl_info_net(struct genl_info *info)
98{
99 return read_pnet(&info->_net);
100}
101
102static inline void genl_info_net_set(struct genl_info *info, struct net *net)
103{
104 write_pnet(&info->_net, net);
105}
106
107#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
108
109enum genl_validate_flags {
110 GENL_DONT_VALIDATE_STRICT = BIT(0),
111 GENL_DONT_VALIDATE_DUMP = BIT(1),
112 GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
113};
114
115/**
116 * struct genl_small_ops - generic netlink operations (small version)
117 * @cmd: command identifier
118 * @internal_flags: flags used by the family
119 * @flags: flags
120 * @validate: validation flags from enum genl_validate_flags
121 * @doit: standard command callback
122 * @dumpit: callback for dumpers
123 *
124 * This is a cut-down version of struct genl_ops for users who don't need
125 * most of the ancillary infra and want to save space.
126 */
127struct genl_small_ops {
128 int (*doit)(struct sk_buff *skb, struct genl_info *info);
129 int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb);
130 u8 cmd;
131 u8 internal_flags;
132 u8 flags;
133 u8 validate;
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 * @maxattr: maximum number of attributes supported
142 * @policy: netlink policy (takes precedence over family policy)
143 * @validate: validation flags from enum genl_validate_flags
144 * @doit: standard command callback
145 * @start: start callback for dumps
146 * @dumpit: callback for dumpers
147 * @done: completion callback for dumps
148 */
149struct genl_ops {
150 int (*doit)(struct sk_buff *skb,
151 struct genl_info *info);
152 int (*start)(struct netlink_callback *cb);
153 int (*dumpit)(struct sk_buff *skb,
154 struct netlink_callback *cb);
155 int (*done)(struct netlink_callback *cb);
156 const struct nla_policy *policy;
157 unsigned int maxattr;
158 u8 cmd;
159 u8 internal_flags;
160 u8 flags;
161 u8 validate;
162};
163
164/**
165 * struct genl_info - info that is available during dumpit op call
166 * @family: generic netlink family - for internal genl code usage
167 * @ops: generic netlink ops - for internal genl code usage
168 * @attrs: netlink attributes
169 */
170struct genl_dumpit_info {
171 const struct genl_family *family;
172 struct genl_ops op;
173 struct nlattr **attrs;
174};
175
176static inline const struct genl_dumpit_info *
177genl_dumpit_info(struct netlink_callback *cb)
178{
179 return cb->data;
180}
181
182int genl_register_family(struct genl_family *family);
183int genl_unregister_family(const struct genl_family *family);
184void genl_notify(const struct genl_family *family, struct sk_buff *skb,
185 struct genl_info *info, u32 group, gfp_t flags);
186
187void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
188 const struct genl_family *family, int flags, u8 cmd);
189
190/**
191 * genlmsg_nlhdr - Obtain netlink header from user specified header
192 * @user_hdr: user header as returned from genlmsg_put()
193 *
194 * Returns pointer to netlink header.
195 */
196static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
197{
198 return (struct nlmsghdr *)((char *)user_hdr -
199 GENL_HDRLEN -
200 NLMSG_HDRLEN);
201}
202
203/**
204 * genlmsg_parse_deprecated - parse attributes of a genetlink message
205 * @nlh: netlink message header
206 * @family: genetlink message family
207 * @tb: destination array with maxtype+1 elements
208 * @maxtype: maximum attribute type to be expected
209 * @policy: validation policy
210 * @extack: extended ACK report struct
211 */
212static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
213 const struct genl_family *family,
214 struct nlattr *tb[], int maxtype,
215 const struct nla_policy *policy,
216 struct netlink_ext_ack *extack)
217{
218 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
219 policy, NL_VALIDATE_LIBERAL, extack);
220}
221
222/**
223 * genlmsg_parse - parse attributes of a genetlink message
224 * @nlh: netlink message header
225 * @family: genetlink message family
226 * @tb: destination array with maxtype+1 elements
227 * @maxtype: maximum attribute type to be expected
228 * @policy: validation policy
229 * @extack: extended ACK report struct
230 */
231static inline int genlmsg_parse(const struct nlmsghdr *nlh,
232 const struct genl_family *family,
233 struct nlattr *tb[], int maxtype,
234 const struct nla_policy *policy,
235 struct netlink_ext_ack *extack)
236{
237 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
238 policy, NL_VALIDATE_STRICT, extack);
239}
240
241/**
242 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
243 * @cb: netlink callback structure that stores the sequence number
244 * @user_hdr: user header as returned from genlmsg_put()
245 *
246 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
247 * simpler to use with generic netlink.
248 */
249static inline void genl_dump_check_consistent(struct netlink_callback *cb,
250 void *user_hdr)
251{
252 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
253}
254
255/**
256 * genlmsg_put_reply - Add generic netlink header to a reply message
257 * @skb: socket buffer holding the message
258 * @info: receiver info
259 * @family: generic netlink family
260 * @flags: netlink message flags
261 * @cmd: generic netlink command
262 *
263 * Returns pointer to user specific header
264 */
265static inline void *genlmsg_put_reply(struct sk_buff *skb,
266 struct genl_info *info,
267 const struct genl_family *family,
268 int flags, u8 cmd)
269{
270 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
271 flags, cmd);
272}
273
274/**
275 * genlmsg_end - Finalize a generic netlink message
276 * @skb: socket buffer the message is stored in
277 * @hdr: user specific header
278 */
279static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
280{
281 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
282}
283
284/**
285 * genlmsg_cancel - Cancel construction of a generic netlink message
286 * @skb: socket buffer the message is stored in
287 * @hdr: generic netlink message header
288 */
289static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
290{
291 if (hdr)
292 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
293}
294
295/**
296 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
297 * @family: the generic netlink family
298 * @net: the net namespace
299 * @skb: netlink message as socket buffer
300 * @portid: own netlink portid to avoid sending to yourself
301 * @group: offset of multicast group in groups array
302 * @flags: allocation flags
303 */
304static inline int genlmsg_multicast_netns(const struct genl_family *family,
305 struct net *net, struct sk_buff *skb,
306 u32 portid, unsigned int group, gfp_t flags)
307{
308 if (WARN_ON_ONCE(group >= family->n_mcgrps))
309 return -EINVAL;
310 group = family->mcgrp_offset + group;
311 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
312}
313
314/**
315 * genlmsg_multicast - multicast a netlink message to the default netns
316 * @family: the generic netlink family
317 * @skb: netlink message as socket buffer
318 * @portid: own netlink portid to avoid sending to yourself
319 * @group: offset of multicast group in groups array
320 * @flags: allocation flags
321 */
322static inline int genlmsg_multicast(const struct genl_family *family,
323 struct sk_buff *skb, u32 portid,
324 unsigned int group, gfp_t flags)
325{
326 return genlmsg_multicast_netns(family, &init_net, skb,
327 portid, group, flags);
328}
329
330/**
331 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
332 * @family: the generic netlink family
333 * @skb: netlink message as socket buffer
334 * @portid: own netlink portid to avoid sending to yourself
335 * @group: offset of multicast group in groups array
336 * @flags: allocation flags
337 *
338 * This function must hold the RTNL or rcu_read_lock().
339 */
340int genlmsg_multicast_allns(const struct genl_family *family,
341 struct sk_buff *skb, u32 portid,
342 unsigned int group, gfp_t flags);
343
344/**
345 * genlmsg_unicast - unicast a netlink message
346 * @skb: netlink message as socket buffer
347 * @portid: netlink portid of the destination socket
348 */
349static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
350{
351 return nlmsg_unicast(net->genl_sock, skb, portid);
352}
353
354/**
355 * genlmsg_reply - reply to a request
356 * @skb: netlink message to be sent back
357 * @info: receiver information
358 */
359static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
360{
361 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
362}
363
364/**
365 * gennlmsg_data - head of message payload
366 * @gnlh: genetlink message header
367 */
368static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
369{
370 return ((unsigned char *) gnlh + GENL_HDRLEN);
371}
372
373/**
374 * genlmsg_len - length of message payload
375 * @gnlh: genetlink message header
376 */
377static inline int genlmsg_len(const struct genlmsghdr *gnlh)
378{
379 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
380 NLMSG_HDRLEN);
381 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
382}
383
384/**
385 * genlmsg_msg_size - length of genetlink message not including padding
386 * @payload: length of message payload
387 */
388static inline int genlmsg_msg_size(int payload)
389{
390 return GENL_HDRLEN + payload;
391}
392
393/**
394 * genlmsg_total_size - length of genetlink message including padding
395 * @payload: length of message payload
396 */
397static inline int genlmsg_total_size(int payload)
398{
399 return NLMSG_ALIGN(genlmsg_msg_size(payload));
400}
401
402/**
403 * genlmsg_new - Allocate a new generic netlink message
404 * @payload: size of the message payload
405 * @flags: the type of memory to allocate.
406 */
407static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
408{
409 return nlmsg_new(genlmsg_total_size(payload), flags);
410}
411
412/**
413 * genl_set_err - report error to genetlink broadcast listeners
414 * @family: the generic netlink family
415 * @net: the network namespace to report the error to
416 * @portid: the PORTID of a process that we want to skip (if any)
417 * @group: the broadcast group that will notice the error
418 * (this is the offset of the multicast group in the groups array)
419 * @code: error code, must be negative (as usual in kernelspace)
420 *
421 * This function returns the number of broadcast listeners that have set the
422 * NETLINK_RECV_NO_ENOBUFS socket option.
423 */
424static inline int genl_set_err(const struct genl_family *family,
425 struct net *net, u32 portid,
426 u32 group, int code)
427{
428 if (WARN_ON_ONCE(group >= family->n_mcgrps))
429 return -EINVAL;
430 group = family->mcgrp_offset + group;
431 return netlink_set_err(net->genl_sock, portid, group, code);
432}
433
434static inline int genl_has_listeners(const struct genl_family *family,
435 struct net *net, unsigned int group)
436{
437 if (WARN_ON_ONCE(group >= family->n_mcgrps))
438 return -EINVAL;
439 group = family->mcgrp_offset + group;
440 return netlink_has_listeners(net->genl_sock, group);
441}
442#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 */