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482a8524 TG |
1 | #ifndef __NET_GENERIC_NETLINK_H |
2 | #define __NET_GENERIC_NETLINK_H | |
3 | ||
4 | #include <linux/genetlink.h> | |
5 | #include <net/netlink.h> | |
134e6375 | 6 | #include <net/net_namespace.h> |
482a8524 | 7 | |
58050fce TG |
8 | #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) |
9 | ||
2dbba6f7 JB |
10 | /** |
11 | * struct genl_multicast_group - generic netlink multicast group | |
12 | * @name: name of the multicast group, names are per-family | |
2dbba6f7 | 13 | */ |
fd2c3ef7 | 14 | struct genl_multicast_group { |
2dbba6f7 | 15 | char name[GENL_NAMSIZ]; |
2dbba6f7 JB |
16 | }; |
17 | ||
ff4c92d8 JB |
18 | struct genl_ops; |
19 | struct genl_info; | |
20 | ||
482a8524 TG |
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 | |
134e6375 JB |
28 | * @netnsok: set to true if the family can handle network |
29 | * namespaces and should be presented in all of them | |
f555f3d7 JB |
30 | * @parallel_ops: operations can be called in parallel and aren't |
31 | * synchronized by the core genetlink code | |
ff4c92d8 JB |
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 | |
c380d9a7 JB |
36 | * @mcast_bind: a socket bound to the given multicast group (which |
37 | * is given as the offset into the groups array) | |
ee1c2442 JB |
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. | |
482a8524 | 42 | * @attrbuf: buffer to store parsed attributes |
482a8524 | 43 | * @family_list: family list |
2a94fe48 JB |
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 | |
d91824c0 JB |
47 | * @ops: the operations supported by this family (private) |
48 | * @n_ops: number of operations supported by this family (private) | |
482a8524 | 49 | */ |
fd2c3ef7 | 50 | struct genl_family { |
482a8524 TG |
51 | unsigned int id; |
52 | unsigned int hdrsize; | |
53 | char name[GENL_NAMSIZ]; | |
54 | unsigned int version; | |
55 | unsigned int maxattr; | |
134e6375 | 56 | bool netnsok; |
def31174 | 57 | bool parallel_ops; |
f84f771d | 58 | int (*pre_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
59 | struct sk_buff *skb, |
60 | struct genl_info *info); | |
f84f771d | 61 | void (*post_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
62 | struct sk_buff *skb, |
63 | struct genl_info *info); | |
023e2cfa JB |
64 | int (*mcast_bind)(struct net *net, int group); |
65 | void (*mcast_unbind)(struct net *net, int group); | |
482a8524 | 66 | struct nlattr ** attrbuf; /* private */ |
f84f771d | 67 | const struct genl_ops * ops; /* private */ |
2a94fe48 | 68 | const struct genl_multicast_group *mcgrps; /* private */ |
d91824c0 | 69 | unsigned int n_ops; /* private */ |
2a94fe48 JB |
70 | unsigned int n_mcgrps; /* private */ |
71 | unsigned int mcgrp_offset; /* private */ | |
482a8524 | 72 | struct list_head family_list; /* private */ |
33c6b1f6 | 73 | struct module *module; |
482a8524 TG |
74 | }; |
75 | ||
482a8524 TG |
76 | /** |
77 | * struct genl_info - receiving information | |
78 | * @snd_seq: sending sequence number | |
15e47304 | 79 | * @snd_portid: netlink portid of sender |
482a8524 TG |
80 | * @nlhdr: netlink message header |
81 | * @genlhdr: generic netlink message header | |
82 | * @userhdr: user specific header | |
83 | * @attrs: netlink attributes | |
ff4c92d8 JB |
84 | * @_net: network namespace |
85 | * @user_ptr: user pointers | |
bb9b18fb | 86 | * @dst_sk: destination socket |
482a8524 | 87 | */ |
fd2c3ef7 | 88 | struct genl_info { |
482a8524 | 89 | u32 snd_seq; |
15e47304 | 90 | u32 snd_portid; |
482a8524 TG |
91 | struct nlmsghdr * nlhdr; |
92 | struct genlmsghdr * genlhdr; | |
93 | void * userhdr; | |
94 | struct nlattr ** attrs; | |
134e6375 JB |
95 | #ifdef CONFIG_NET_NS |
96 | struct net * _net; | |
97 | #endif | |
ff4c92d8 | 98 | void * user_ptr[2]; |
bb9b18fb | 99 | struct sock * dst_sk; |
482a8524 TG |
100 | }; |
101 | ||
134e6375 JB |
102 | static inline struct net *genl_info_net(struct genl_info *info) |
103 | { | |
c2d9ba9b | 104 | return read_pnet(&info->_net); |
134e6375 JB |
105 | } |
106 | ||
107 | static inline void genl_info_net_set(struct genl_info *info, struct net *net) | |
108 | { | |
c2d9ba9b | 109 | write_pnet(&info->_net, net); |
134e6375 | 110 | } |
134e6375 | 111 | |
482a8524 TG |
112 | /** |
113 | * struct genl_ops - generic netlink operations | |
114 | * @cmd: command identifier | |
ff4c92d8 | 115 | * @internal_flags: flags used by the family |
482a8524 TG |
116 | * @flags: flags |
117 | * @policy: attribute validation policy | |
118 | * @doit: standard command callback | |
119 | * @dumpit: callback for dumpers | |
a4d1366d | 120 | * @done: completion callback for dumps |
482a8524 TG |
121 | * @ops_list: operations list |
122 | */ | |
fd2c3ef7 | 123 | struct genl_ops { |
ef7c79ed | 124 | const struct nla_policy *policy; |
482a8524 TG |
125 | int (*doit)(struct sk_buff *skb, |
126 | struct genl_info *info); | |
127 | int (*dumpit)(struct sk_buff *skb, | |
128 | struct netlink_callback *cb); | |
a4d1366d | 129 | int (*done)(struct netlink_callback *cb); |
3f5ccd06 JB |
130 | u8 cmd; |
131 | u8 internal_flags; | |
132 | u8 flags; | |
482a8524 TG |
133 | }; |
134 | ||
ff2b94d2 | 135 | int __genl_register_family(struct genl_family *family); |
33c6b1f6 PS |
136 | |
137 | static inline int genl_register_family(struct genl_family *family) | |
138 | { | |
139 | family->module = THIS_MODULE; | |
140 | return __genl_register_family(family); | |
141 | } | |
142 | ||
568508aa JB |
143 | /** |
144 | * genl_register_family_with_ops - register a generic netlink family with ops | |
145 | * @family: generic netlink family | |
146 | * @ops: operations to be registered | |
147 | * @n_ops: number of elements to register | |
148 | * | |
149 | * Registers the specified family and operations from the specified table. | |
150 | * Only one family may be registered with the same family name or identifier. | |
151 | * | |
152 | * The family id may equal GENL_ID_GENERATE causing an unique id to | |
153 | * be automatically generated and assigned. | |
154 | * | |
155 | * Either a doit or dumpit callback must be specified for every registered | |
156 | * operation or the function will fail. Only one operation structure per | |
157 | * command identifier may be registered. | |
158 | * | |
159 | * See include/net/genetlink.h for more documenation on the operations | |
160 | * structure. | |
161 | * | |
162 | * Return 0 on success or a negative error code. | |
163 | */ | |
2a94fe48 JB |
164 | static inline int |
165 | _genl_register_family_with_ops_grps(struct genl_family *family, | |
166 | const struct genl_ops *ops, size_t n_ops, | |
167 | const struct genl_multicast_group *mcgrps, | |
168 | size_t n_mcgrps) | |
33c6b1f6 PS |
169 | { |
170 | family->module = THIS_MODULE; | |
568508aa JB |
171 | family->ops = ops; |
172 | family->n_ops = n_ops; | |
2a94fe48 JB |
173 | family->mcgrps = mcgrps; |
174 | family->n_mcgrps = n_mcgrps; | |
568508aa | 175 | return __genl_register_family(family); |
33c6b1f6 PS |
176 | } |
177 | ||
2a94fe48 JB |
178 | #define genl_register_family_with_ops(family, ops) \ |
179 | _genl_register_family_with_ops_grps((family), \ | |
180 | (ops), ARRAY_SIZE(ops), \ | |
181 | NULL, 0) | |
182 | #define genl_register_family_with_ops_groups(family, ops, grps) \ | |
183 | _genl_register_family_with_ops_grps((family), \ | |
184 | (ops), ARRAY_SIZE(ops), \ | |
185 | (grps), ARRAY_SIZE(grps)) | |
c53ed742 | 186 | |
ff2b94d2 | 187 | int genl_unregister_family(struct genl_family *family); |
68eb5503 JB |
188 | void genl_notify(struct genl_family *family, |
189 | struct sk_buff *skb, struct net *net, u32 portid, | |
ff2b94d2 | 190 | u32 group, struct nlmsghdr *nlh, gfp_t flags); |
482a8524 | 191 | |
bb9b18fb TG |
192 | struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info, |
193 | gfp_t flags); | |
15e47304 | 194 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
ff2b94d2 | 195 | struct genl_family *family, int flags, u8 cmd); |
482a8524 | 196 | |
670dc283 JB |
197 | /** |
198 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
199 | * @user_hdr: user header as returned from genlmsg_put() | |
200 | * @family: generic netlink family | |
201 | * | |
202 | * Returns pointer to netlink header. | |
203 | */ | |
204 | static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr, | |
205 | struct genl_family *family) | |
206 | { | |
207 | return (struct nlmsghdr *)((char *)user_hdr - | |
208 | family->hdrsize - | |
209 | GENL_HDRLEN - | |
210 | NLMSG_HDRLEN); | |
211 | } | |
212 | ||
7b1883ce JS |
213 | /** |
214 | * genlmsg_parse - parse attributes of a genetlink message | |
215 | * @nlh: netlink message header | |
216 | * @family: genetlink message family | |
217 | * @tb: destination array with maxtype+1 elements | |
218 | * @maxtype: maximum attribute type to be expected | |
219 | * @policy: validation policy | |
220 | * */ | |
221 | static inline int genlmsg_parse(const struct nlmsghdr *nlh, | |
222 | const struct genl_family *family, | |
223 | struct nlattr *tb[], int maxtype, | |
224 | const struct nla_policy *policy) | |
225 | { | |
226 | return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, | |
227 | policy); | |
228 | } | |
229 | ||
670dc283 JB |
230 | /** |
231 | * genl_dump_check_consistent - check if sequence is consistent and advertise if not | |
232 | * @cb: netlink callback structure that stores the sequence number | |
233 | * @user_hdr: user header as returned from genlmsg_put() | |
234 | * @family: generic netlink family | |
235 | * | |
236 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
237 | * simpler to use with generic netlink. | |
238 | */ | |
239 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
240 | void *user_hdr, | |
241 | struct genl_family *family) | |
242 | { | |
243 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family)); | |
244 | } | |
245 | ||
17c157c8 TG |
246 | /** |
247 | * genlmsg_put_reply - Add generic netlink header to a reply message | |
248 | * @skb: socket buffer holding the message | |
249 | * @info: receiver info | |
250 | * @family: generic netlink family | |
251 | * @flags: netlink message flags | |
252 | * @cmd: generic netlink command | |
253 | * | |
254 | * Returns pointer to user specific header | |
255 | */ | |
256 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
257 | struct genl_info *info, | |
258 | struct genl_family *family, | |
259 | int flags, u8 cmd) | |
260 | { | |
15e47304 | 261 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
262 | flags, cmd); |
263 | } | |
264 | ||
482a8524 TG |
265 | /** |
266 | * genlmsg_end - Finalize a generic netlink message | |
267 | * @skb: socket buffer the message is stored in | |
268 | * @hdr: user specific header | |
269 | */ | |
053c095a | 270 | static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
482a8524 | 271 | { |
053c095a | 272 | nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
482a8524 TG |
273 | } |
274 | ||
275 | /** | |
276 | * genlmsg_cancel - Cancel construction of a generic netlink message | |
277 | * @skb: socket buffer the message is stored in | |
278 | * @hdr: generic netlink message header | |
279 | */ | |
bc3ed28c | 280 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 281 | { |
38db9e1d JL |
282 | if (hdr) |
283 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
284 | } |
285 | ||
286 | /** | |
134e6375 | 287 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 288 | * @family: the generic netlink family |
134e6375 JB |
289 | * @net: the net namespace |
290 | * @skb: netlink message as socket buffer | |
15e47304 | 291 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 292 | * @group: offset of multicast group in groups array |
134e6375 JB |
293 | * @flags: allocation flags |
294 | */ | |
68eb5503 JB |
295 | static inline int genlmsg_multicast_netns(struct genl_family *family, |
296 | struct net *net, struct sk_buff *skb, | |
15e47304 | 297 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 298 | { |
220815a9 | 299 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
300 | return -EINVAL; |
301 | group = family->mcgrp_offset + group; | |
15e47304 | 302 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
303 | } |
304 | ||
305 | /** | |
306 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 307 | * @family: the generic netlink family |
482a8524 | 308 | * @skb: netlink message as socket buffer |
15e47304 | 309 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 310 | * @group: offset of multicast group in groups array |
d387f6ad | 311 | * @flags: allocation flags |
482a8524 | 312 | */ |
68eb5503 JB |
313 | static inline int genlmsg_multicast(struct genl_family *family, |
314 | struct sk_buff *skb, u32 portid, | |
d387f6ad | 315 | unsigned int group, gfp_t flags) |
482a8524 | 316 | { |
68eb5503 JB |
317 | return genlmsg_multicast_netns(family, &init_net, skb, |
318 | portid, group, flags); | |
482a8524 TG |
319 | } |
320 | ||
134e6375 JB |
321 | /** |
322 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 323 | * @family: the generic netlink family |
134e6375 | 324 | * @skb: netlink message as socket buffer |
15e47304 | 325 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 326 | * @group: offset of multicast group in groups array |
134e6375 JB |
327 | * @flags: allocation flags |
328 | * | |
329 | * This function must hold the RTNL or rcu_read_lock(). | |
330 | */ | |
68eb5503 JB |
331 | int genlmsg_multicast_allns(struct genl_family *family, |
332 | struct sk_buff *skb, u32 portid, | |
134e6375 JB |
333 | unsigned int group, gfp_t flags); |
334 | ||
482a8524 TG |
335 | /** |
336 | * genlmsg_unicast - unicast a netlink message | |
337 | * @skb: netlink message as socket buffer | |
15e47304 | 338 | * @portid: netlink portid of the destination socket |
482a8524 | 339 | */ |
15e47304 | 340 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 341 | { |
15e47304 | 342 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
343 | } |
344 | ||
81878d27 TG |
345 | /** |
346 | * genlmsg_reply - reply to a request | |
347 | * @skb: netlink message to be sent back | |
348 | * @info: receiver information | |
349 | */ | |
350 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
351 | { | |
15e47304 | 352 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
353 | } |
354 | ||
fb0ba6bd BS |
355 | /** |
356 | * gennlmsg_data - head of message payload | |
70f23fd6 | 357 | * @gnlh: genetlink message header |
fb0ba6bd BS |
358 | */ |
359 | static inline void *genlmsg_data(const struct genlmsghdr *gnlh) | |
360 | { | |
361 | return ((unsigned char *) gnlh + GENL_HDRLEN); | |
362 | } | |
363 | ||
364 | /** | |
365 | * genlmsg_len - length of message payload | |
366 | * @gnlh: genetlink message header | |
367 | */ | |
368 | static inline int genlmsg_len(const struct genlmsghdr *gnlh) | |
369 | { | |
370 | struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - | |
371 | NLMSG_HDRLEN); | |
372 | return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); | |
373 | } | |
374 | ||
17db952c BS |
375 | /** |
376 | * genlmsg_msg_size - length of genetlink message not including padding | |
377 | * @payload: length of message payload | |
378 | */ | |
379 | static inline int genlmsg_msg_size(int payload) | |
380 | { | |
381 | return GENL_HDRLEN + payload; | |
382 | } | |
383 | ||
384 | /** | |
385 | * genlmsg_total_size - length of genetlink message including padding | |
386 | * @payload: length of message payload | |
387 | */ | |
388 | static inline int genlmsg_total_size(int payload) | |
389 | { | |
390 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
391 | } | |
392 | ||
3dabc715 TG |
393 | /** |
394 | * genlmsg_new - Allocate a new generic netlink message | |
395 | * @payload: size of the message payload | |
396 | * @flags: the type of memory to allocate. | |
397 | */ | |
398 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
399 | { | |
400 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
401 | } | |
402 | ||
62b68e99 JB |
403 | /** |
404 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 405 | * @family: the generic netlink family |
62b68e99 JB |
406 | * @net: the network namespace to report the error to |
407 | * @portid: the PORTID of a process that we want to skip (if any) | |
408 | * @group: the broadcast group that will notice the error | |
2a94fe48 | 409 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
410 | * @code: error code, must be negative (as usual in kernelspace) |
411 | * | |
412 | * This function returns the number of broadcast listeners that have set the | |
413 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
414 | */ | |
68eb5503 JB |
415 | static inline int genl_set_err(struct genl_family *family, struct net *net, |
416 | u32 portid, u32 group, int code) | |
62b68e99 | 417 | { |
91398a09 JB |
418 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
419 | return -EINVAL; | |
420 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
421 | return netlink_set_err(net->genl_sock, portid, group, code); |
422 | } | |
3dabc715 | 423 | |
0d566379 | 424 | static inline int genl_has_listeners(struct genl_family *family, |
f8403a2e | 425 | struct net *net, unsigned int group) |
0d566379 ND |
426 | { |
427 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) | |
428 | return -EINVAL; | |
429 | group = family->mcgrp_offset + group; | |
f8403a2e | 430 | return netlink_has_listeners(net->genl_sock, group); |
0d566379 | 431 | } |
482a8524 | 432 | #endif /* __NET_GENERIC_NETLINK_H */ |