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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
482a8524 TG |
2 | #ifndef __NET_GENERIC_NETLINK_H |
3 | #define __NET_GENERIC_NETLINK_H | |
4 | ||
5 | #include <linux/genetlink.h> | |
6 | #include <net/netlink.h> | |
134e6375 | 7 | #include <net/net_namespace.h> |
482a8524 | 8 | |
58050fce TG |
9 | #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) |
10 | ||
2dbba6f7 JB |
11 | /** |
12 | * struct genl_multicast_group - generic netlink multicast group | |
13 | * @name: name of the multicast group, names are per-family | |
2dbba6f7 | 14 | */ |
fd2c3ef7 | 15 | struct genl_multicast_group { |
2dbba6f7 | 16 | char name[GENL_NAMSIZ]; |
4d54cc32 | 17 | u8 flags; |
2dbba6f7 JB |
18 | }; |
19 | ||
ff4c92d8 JB |
20 | struct genl_ops; |
21 | struct genl_info; | |
22 | ||
482a8524 TG |
23 | /** |
24 | * struct genl_family - generic netlink family | |
a07ea4d9 | 25 | * @id: protocol family identifier (private) |
482a8524 TG |
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 | |
3b0f31f2 | 30 | * @policy: netlink policy |
134e6375 JB |
31 | * @netnsok: set to true if the family can handle network |
32 | * namespaces and should be presented in all of them | |
f555f3d7 JB |
33 | * @parallel_ops: operations can be called in parallel and aren't |
34 | * synchronized by the core genetlink code | |
ff4c92d8 JB |
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 | |
489111e5 JB |
39 | * @mcgrps: multicast groups used by this family |
40 | * @n_mcgrps: number of multicast groups | |
2a94fe48 | 41 | * @mcgrp_offset: starting number of multicast group IDs in this family |
489111e5 JB |
42 | * (private) |
43 | * @ops: the operations supported by this family | |
44 | * @n_ops: number of operations supported by this family | |
0b588afd JK |
45 | * @small_ops: the small-struct operations supported by this family |
46 | * @n_small_ops: number of small-struct operations supported by this family | |
482a8524 | 47 | */ |
fd2c3ef7 | 48 | struct genl_family { |
98e4321b | 49 | int id; /* private */ |
482a8524 TG |
50 | unsigned int hdrsize; |
51 | char name[GENL_NAMSIZ]; | |
52 | unsigned int version; | |
53 | unsigned int maxattr; | |
e5086736 JK |
54 | unsigned int mcgrp_offset; /* private */ |
55 | u8 netnsok:1; | |
56 | u8 parallel_ops:1; | |
57 | u8 n_ops; | |
0b588afd | 58 | u8 n_small_ops; |
e5086736 | 59 | u8 n_mcgrps; |
3b0f31f2 | 60 | const struct nla_policy *policy; |
f84f771d | 61 | int (*pre_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
62 | struct sk_buff *skb, |
63 | struct genl_info *info); | |
f84f771d | 64 | void (*post_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
65 | struct sk_buff *skb, |
66 | struct genl_info *info); | |
489111e5 | 67 | const struct genl_ops * ops; |
0b588afd | 68 | const struct genl_small_ops *small_ops; |
489111e5 | 69 | const struct genl_multicast_group *mcgrps; |
33c6b1f6 | 70 | struct module *module; |
482a8524 TG |
71 | }; |
72 | ||
482a8524 TG |
73 | /** |
74 | * struct genl_info - receiving information | |
75 | * @snd_seq: sending sequence number | |
15e47304 | 76 | * @snd_portid: netlink portid of sender |
482a8524 TG |
77 | * @nlhdr: netlink message header |
78 | * @genlhdr: generic netlink message header | |
79 | * @userhdr: user specific header | |
80 | * @attrs: netlink attributes | |
ff4c92d8 JB |
81 | * @_net: network namespace |
82 | * @user_ptr: user pointers | |
7ab606d1 | 83 | * @extack: extended ACK report struct |
482a8524 | 84 | */ |
fd2c3ef7 | 85 | struct genl_info { |
482a8524 | 86 | u32 snd_seq; |
15e47304 | 87 | u32 snd_portid; |
482a8524 TG |
88 | struct nlmsghdr * nlhdr; |
89 | struct genlmsghdr * genlhdr; | |
90 | void * userhdr; | |
91 | struct nlattr ** attrs; | |
0c5c9fb5 | 92 | possible_net_t _net; |
ff4c92d8 | 93 | void * user_ptr[2]; |
7ab606d1 | 94 | struct netlink_ext_ack *extack; |
482a8524 TG |
95 | }; |
96 | ||
134e6375 JB |
97 | static inline struct net *genl_info_net(struct genl_info *info) |
98 | { | |
c2d9ba9b | 99 | return read_pnet(&info->_net); |
134e6375 JB |
100 | } |
101 | ||
102 | static inline void genl_info_net_set(struct genl_info *info, struct net *net) | |
103 | { | |
c2d9ba9b | 104 | write_pnet(&info->_net, net); |
134e6375 | 105 | } |
134e6375 | 106 | |
7ab606d1 JB |
107 | #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) |
108 | ||
ef6243ac JB |
109 | enum 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 | ||
1927f41a | 115 | /** |
0b588afd JK |
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. | |
1927f41a | 126 | */ |
0b588afd JK |
127 | struct 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; | |
1927f41a JP |
134 | }; |
135 | ||
482a8524 TG |
136 | /** |
137 | * struct genl_ops - generic netlink operations | |
138 | * @cmd: command identifier | |
ff4c92d8 | 139 | * @internal_flags: flags used by the family |
482a8524 | 140 | * @flags: flags |
48526a0f JK |
141 | * @maxattr: maximum number of attributes supported |
142 | * @policy: netlink policy (takes precedence over family policy) | |
3ddf9b43 | 143 | * @validate: validation flags from enum genl_validate_flags |
482a8524 | 144 | * @doit: standard command callback |
fc9e50f5 | 145 | * @start: start callback for dumps |
482a8524 | 146 | * @dumpit: callback for dumpers |
a4d1366d | 147 | * @done: completion callback for dumps |
482a8524 | 148 | */ |
fd2c3ef7 | 149 | struct genl_ops { |
482a8524 TG |
150 | int (*doit)(struct sk_buff *skb, |
151 | struct genl_info *info); | |
fc9e50f5 | 152 | int (*start)(struct netlink_callback *cb); |
482a8524 TG |
153 | int (*dumpit)(struct sk_buff *skb, |
154 | struct netlink_callback *cb); | |
a4d1366d | 155 | int (*done)(struct netlink_callback *cb); |
48526a0f JK |
156 | const struct nla_policy *policy; |
157 | unsigned int maxattr; | |
3f5ccd06 JB |
158 | u8 cmd; |
159 | u8 internal_flags; | |
160 | u8 flags; | |
ef6243ac | 161 | u8 validate; |
482a8524 TG |
162 | }; |
163 | ||
0b588afd JK |
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 | */ | |
170 | struct genl_dumpit_info { | |
171 | const struct genl_family *family; | |
172 | struct genl_ops op; | |
173 | struct nlattr **attrs; | |
174 | }; | |
175 | ||
176 | static inline const struct genl_dumpit_info * | |
177 | genl_dumpit_info(struct netlink_callback *cb) | |
178 | { | |
179 | return cb->data; | |
180 | } | |
181 | ||
489111e5 | 182 | int genl_register_family(struct genl_family *family); |
2ae0f17d JB |
183 | int genl_unregister_family(const struct genl_family *family); |
184 | void genl_notify(const struct genl_family *family, struct sk_buff *skb, | |
92c14d9b | 185 | struct genl_info *info, u32 group, gfp_t flags); |
482a8524 | 186 | |
15e47304 | 187 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
2ae0f17d | 188 | const struct genl_family *family, int flags, u8 cmd); |
482a8524 | 189 | |
670dc283 JB |
190 | /** |
191 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
192 | * @user_hdr: user header as returned from genlmsg_put() | |
670dc283 JB |
193 | * |
194 | * Returns pointer to netlink header. | |
195 | */ | |
0a833c29 | 196 | static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr) |
670dc283 JB |
197 | { |
198 | return (struct nlmsghdr *)((char *)user_hdr - | |
670dc283 JB |
199 | GENL_HDRLEN - |
200 | NLMSG_HDRLEN); | |
201 | } | |
202 | ||
7b1883ce | 203 | /** |
8cb08174 | 204 | * genlmsg_parse_deprecated - parse attributes of a genetlink message |
7b1883ce JS |
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 | |
fceb6435 JB |
210 | * @extack: extended ACK report struct |
211 | */ | |
8cb08174 JB |
212 | static 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) | |
7b1883ce | 217 | { |
8cb08174 JB |
218 | return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, |
219 | policy, NL_VALIDATE_LIBERAL, extack); | |
7b1883ce JS |
220 | } |
221 | ||
3de64403 JB |
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 | */ | |
231 | static 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 | ||
670dc283 JB |
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() | |
670dc283 JB |
245 | * |
246 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
247 | * simpler to use with generic netlink. | |
248 | */ | |
249 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
0a833c29 | 250 | void *user_hdr) |
670dc283 | 251 | { |
0a833c29 | 252 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr)); |
670dc283 JB |
253 | } |
254 | ||
17c157c8 TG |
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 | */ | |
265 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
266 | struct genl_info *info, | |
2ae0f17d | 267 | const struct genl_family *family, |
17c157c8 TG |
268 | int flags, u8 cmd) |
269 | { | |
15e47304 | 270 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
271 | flags, cmd); |
272 | } | |
273 | ||
482a8524 TG |
274 | /** |
275 | * genlmsg_end - Finalize a generic netlink message | |
276 | * @skb: socket buffer the message is stored in | |
277 | * @hdr: user specific header | |
278 | */ | |
053c095a | 279 | static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
482a8524 | 280 | { |
053c095a | 281 | nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
482a8524 TG |
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 | */ | |
bc3ed28c | 289 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 290 | { |
38db9e1d JL |
291 | if (hdr) |
292 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
293 | } |
294 | ||
295 | /** | |
134e6375 | 296 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 297 | * @family: the generic netlink family |
134e6375 JB |
298 | * @net: the net namespace |
299 | * @skb: netlink message as socket buffer | |
15e47304 | 300 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 301 | * @group: offset of multicast group in groups array |
134e6375 JB |
302 | * @flags: allocation flags |
303 | */ | |
2ae0f17d | 304 | static inline int genlmsg_multicast_netns(const struct genl_family *family, |
68eb5503 | 305 | struct net *net, struct sk_buff *skb, |
15e47304 | 306 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 307 | { |
220815a9 | 308 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
309 | return -EINVAL; |
310 | group = family->mcgrp_offset + group; | |
15e47304 | 311 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
312 | } |
313 | ||
314 | /** | |
315 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 316 | * @family: the generic netlink family |
482a8524 | 317 | * @skb: netlink message as socket buffer |
15e47304 | 318 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 319 | * @group: offset of multicast group in groups array |
d387f6ad | 320 | * @flags: allocation flags |
482a8524 | 321 | */ |
2ae0f17d | 322 | static inline int genlmsg_multicast(const struct genl_family *family, |
68eb5503 | 323 | struct sk_buff *skb, u32 portid, |
d387f6ad | 324 | unsigned int group, gfp_t flags) |
482a8524 | 325 | { |
68eb5503 JB |
326 | return genlmsg_multicast_netns(family, &init_net, skb, |
327 | portid, group, flags); | |
482a8524 TG |
328 | } |
329 | ||
134e6375 JB |
330 | /** |
331 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 332 | * @family: the generic netlink family |
134e6375 | 333 | * @skb: netlink message as socket buffer |
15e47304 | 334 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 335 | * @group: offset of multicast group in groups array |
134e6375 JB |
336 | * @flags: allocation flags |
337 | * | |
338 | * This function must hold the RTNL or rcu_read_lock(). | |
339 | */ | |
2ae0f17d | 340 | int genlmsg_multicast_allns(const struct genl_family *family, |
68eb5503 | 341 | struct sk_buff *skb, u32 portid, |
134e6375 JB |
342 | unsigned int group, gfp_t flags); |
343 | ||
482a8524 TG |
344 | /** |
345 | * genlmsg_unicast - unicast a netlink message | |
346 | * @skb: netlink message as socket buffer | |
15e47304 | 347 | * @portid: netlink portid of the destination socket |
482a8524 | 348 | */ |
15e47304 | 349 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 350 | { |
15e47304 | 351 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
352 | } |
353 | ||
81878d27 TG |
354 | /** |
355 | * genlmsg_reply - reply to a request | |
356 | * @skb: netlink message to be sent back | |
357 | * @info: receiver information | |
358 | */ | |
359 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
360 | { | |
15e47304 | 361 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
362 | } |
363 | ||
fb0ba6bd BS |
364 | /** |
365 | * gennlmsg_data - head of message payload | |
70f23fd6 | 366 | * @gnlh: genetlink message header |
fb0ba6bd BS |
367 | */ |
368 | static 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 | */ | |
377 | static 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 | ||
17db952c BS |
384 | /** |
385 | * genlmsg_msg_size - length of genetlink message not including padding | |
386 | * @payload: length of message payload | |
387 | */ | |
388 | static 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 | */ | |
397 | static inline int genlmsg_total_size(int payload) | |
398 | { | |
399 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
400 | } | |
401 | ||
3dabc715 TG |
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 | */ | |
407 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
408 | { | |
409 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
410 | } | |
411 | ||
62b68e99 JB |
412 | /** |
413 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 414 | * @family: the generic netlink family |
62b68e99 JB |
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 | |
2a94fe48 | 418 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
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 | */ | |
2ae0f17d JB |
424 | static inline int genl_set_err(const struct genl_family *family, |
425 | struct net *net, u32 portid, | |
426 | u32 group, int code) | |
62b68e99 | 427 | { |
91398a09 JB |
428 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
429 | return -EINVAL; | |
430 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
431 | return netlink_set_err(net->genl_sock, portid, group, code); |
432 | } | |
3dabc715 | 433 | |
2ae0f17d | 434 | static inline int genl_has_listeners(const struct genl_family *family, |
f8403a2e | 435 | struct net *net, unsigned int group) |
0d566379 ND |
436 | { |
437 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) | |
438 | return -EINVAL; | |
439 | group = family->mcgrp_offset + group; | |
f8403a2e | 440 | return netlink_has_listeners(net->genl_sock, group); |
0d566379 | 441 | } |
482a8524 | 442 | #endif /* __NET_GENERIC_NETLINK_H */ |