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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; | |
0c5c9fb5 | 95 | possible_net_t _net; |
ff4c92d8 | 96 | void * user_ptr[2]; |
bb9b18fb | 97 | struct sock * dst_sk; |
482a8524 TG |
98 | }; |
99 | ||
134e6375 JB |
100 | static inline struct net *genl_info_net(struct genl_info *info) |
101 | { | |
c2d9ba9b | 102 | return read_pnet(&info->_net); |
134e6375 JB |
103 | } |
104 | ||
105 | static inline void genl_info_net_set(struct genl_info *info, struct net *net) | |
106 | { | |
c2d9ba9b | 107 | write_pnet(&info->_net, net); |
134e6375 | 108 | } |
134e6375 | 109 | |
482a8524 TG |
110 | /** |
111 | * struct genl_ops - generic netlink operations | |
112 | * @cmd: command identifier | |
ff4c92d8 | 113 | * @internal_flags: flags used by the family |
482a8524 TG |
114 | * @flags: flags |
115 | * @policy: attribute validation policy | |
116 | * @doit: standard command callback | |
117 | * @dumpit: callback for dumpers | |
a4d1366d | 118 | * @done: completion callback for dumps |
482a8524 TG |
119 | * @ops_list: operations list |
120 | */ | |
fd2c3ef7 | 121 | struct genl_ops { |
ef7c79ed | 122 | const struct nla_policy *policy; |
482a8524 TG |
123 | int (*doit)(struct sk_buff *skb, |
124 | struct genl_info *info); | |
125 | int (*dumpit)(struct sk_buff *skb, | |
126 | struct netlink_callback *cb); | |
a4d1366d | 127 | int (*done)(struct netlink_callback *cb); |
3f5ccd06 JB |
128 | u8 cmd; |
129 | u8 internal_flags; | |
130 | u8 flags; | |
482a8524 TG |
131 | }; |
132 | ||
ff2b94d2 | 133 | int __genl_register_family(struct genl_family *family); |
33c6b1f6 PS |
134 | |
135 | static inline int genl_register_family(struct genl_family *family) | |
136 | { | |
137 | family->module = THIS_MODULE; | |
138 | return __genl_register_family(family); | |
139 | } | |
140 | ||
568508aa JB |
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 | */ | |
2a94fe48 JB |
162 | static 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) | |
33c6b1f6 PS |
167 | { |
168 | family->module = THIS_MODULE; | |
568508aa JB |
169 | family->ops = ops; |
170 | family->n_ops = n_ops; | |
2a94fe48 JB |
171 | family->mcgrps = mcgrps; |
172 | family->n_mcgrps = n_mcgrps; | |
568508aa | 173 | return __genl_register_family(family); |
33c6b1f6 PS |
174 | } |
175 | ||
2a94fe48 JB |
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)) | |
c53ed742 | 184 | |
ff2b94d2 | 185 | int genl_unregister_family(struct genl_family *family); |
68eb5503 JB |
186 | void genl_notify(struct genl_family *family, |
187 | struct sk_buff *skb, struct net *net, u32 portid, | |
ff2b94d2 | 188 | u32 group, struct nlmsghdr *nlh, gfp_t flags); |
482a8524 | 189 | |
bb9b18fb TG |
190 | struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info, |
191 | gfp_t flags); | |
15e47304 | 192 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
ff2b94d2 | 193 | struct genl_family *family, int flags, u8 cmd); |
482a8524 | 194 | |
670dc283 JB |
195 | /** |
196 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
197 | * @user_hdr: user header as returned from genlmsg_put() | |
198 | * @family: generic netlink family | |
199 | * | |
200 | * Returns pointer to netlink header. | |
201 | */ | |
202 | static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr, | |
203 | struct genl_family *family) | |
204 | { | |
205 | return (struct nlmsghdr *)((char *)user_hdr - | |
206 | family->hdrsize - | |
207 | GENL_HDRLEN - | |
208 | NLMSG_HDRLEN); | |
209 | } | |
210 | ||
7b1883ce JS |
211 | /** |
212 | * genlmsg_parse - parse attributes of a genetlink message | |
213 | * @nlh: netlink message header | |
214 | * @family: genetlink message family | |
215 | * @tb: destination array with maxtype+1 elements | |
216 | * @maxtype: maximum attribute type to be expected | |
217 | * @policy: validation policy | |
218 | * */ | |
219 | static inline int genlmsg_parse(const struct nlmsghdr *nlh, | |
220 | const struct genl_family *family, | |
221 | struct nlattr *tb[], int maxtype, | |
222 | const struct nla_policy *policy) | |
223 | { | |
224 | return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, | |
225 | policy); | |
226 | } | |
227 | ||
670dc283 JB |
228 | /** |
229 | * genl_dump_check_consistent - check if sequence is consistent and advertise if not | |
230 | * @cb: netlink callback structure that stores the sequence number | |
231 | * @user_hdr: user header as returned from genlmsg_put() | |
232 | * @family: generic netlink family | |
233 | * | |
234 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
235 | * simpler to use with generic netlink. | |
236 | */ | |
237 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
238 | void *user_hdr, | |
239 | struct genl_family *family) | |
240 | { | |
241 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family)); | |
242 | } | |
243 | ||
17c157c8 TG |
244 | /** |
245 | * genlmsg_put_reply - Add generic netlink header to a reply message | |
246 | * @skb: socket buffer holding the message | |
247 | * @info: receiver info | |
248 | * @family: generic netlink family | |
249 | * @flags: netlink message flags | |
250 | * @cmd: generic netlink command | |
251 | * | |
252 | * Returns pointer to user specific header | |
253 | */ | |
254 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
255 | struct genl_info *info, | |
256 | struct genl_family *family, | |
257 | int flags, u8 cmd) | |
258 | { | |
15e47304 | 259 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
260 | flags, cmd); |
261 | } | |
262 | ||
482a8524 TG |
263 | /** |
264 | * genlmsg_end - Finalize a generic netlink message | |
265 | * @skb: socket buffer the message is stored in | |
266 | * @hdr: user specific header | |
267 | */ | |
053c095a | 268 | static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
482a8524 | 269 | { |
053c095a | 270 | nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
482a8524 TG |
271 | } |
272 | ||
273 | /** | |
274 | * genlmsg_cancel - Cancel construction of a generic netlink message | |
275 | * @skb: socket buffer the message is stored in | |
276 | * @hdr: generic netlink message header | |
277 | */ | |
bc3ed28c | 278 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 279 | { |
38db9e1d JL |
280 | if (hdr) |
281 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
282 | } |
283 | ||
284 | /** | |
134e6375 | 285 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 286 | * @family: the generic netlink family |
134e6375 JB |
287 | * @net: the net namespace |
288 | * @skb: netlink message as socket buffer | |
15e47304 | 289 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 290 | * @group: offset of multicast group in groups array |
134e6375 JB |
291 | * @flags: allocation flags |
292 | */ | |
68eb5503 JB |
293 | static inline int genlmsg_multicast_netns(struct genl_family *family, |
294 | struct net *net, struct sk_buff *skb, | |
15e47304 | 295 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 296 | { |
220815a9 | 297 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
298 | return -EINVAL; |
299 | group = family->mcgrp_offset + group; | |
15e47304 | 300 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
301 | } |
302 | ||
303 | /** | |
304 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 305 | * @family: the generic netlink family |
482a8524 | 306 | * @skb: netlink message as socket buffer |
15e47304 | 307 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 308 | * @group: offset of multicast group in groups array |
d387f6ad | 309 | * @flags: allocation flags |
482a8524 | 310 | */ |
68eb5503 JB |
311 | static inline int genlmsg_multicast(struct genl_family *family, |
312 | struct sk_buff *skb, u32 portid, | |
d387f6ad | 313 | unsigned int group, gfp_t flags) |
482a8524 | 314 | { |
68eb5503 JB |
315 | return genlmsg_multicast_netns(family, &init_net, skb, |
316 | portid, group, flags); | |
482a8524 TG |
317 | } |
318 | ||
134e6375 JB |
319 | /** |
320 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 321 | * @family: the generic netlink family |
134e6375 | 322 | * @skb: netlink message as socket buffer |
15e47304 | 323 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 324 | * @group: offset of multicast group in groups array |
134e6375 JB |
325 | * @flags: allocation flags |
326 | * | |
327 | * This function must hold the RTNL or rcu_read_lock(). | |
328 | */ | |
68eb5503 JB |
329 | int genlmsg_multicast_allns(struct genl_family *family, |
330 | struct sk_buff *skb, u32 portid, | |
134e6375 JB |
331 | unsigned int group, gfp_t flags); |
332 | ||
482a8524 TG |
333 | /** |
334 | * genlmsg_unicast - unicast a netlink message | |
335 | * @skb: netlink message as socket buffer | |
15e47304 | 336 | * @portid: netlink portid of the destination socket |
482a8524 | 337 | */ |
15e47304 | 338 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 339 | { |
15e47304 | 340 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
341 | } |
342 | ||
81878d27 TG |
343 | /** |
344 | * genlmsg_reply - reply to a request | |
345 | * @skb: netlink message to be sent back | |
346 | * @info: receiver information | |
347 | */ | |
348 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
349 | { | |
15e47304 | 350 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
351 | } |
352 | ||
fb0ba6bd BS |
353 | /** |
354 | * gennlmsg_data - head of message payload | |
70f23fd6 | 355 | * @gnlh: genetlink message header |
fb0ba6bd BS |
356 | */ |
357 | static inline void *genlmsg_data(const struct genlmsghdr *gnlh) | |
358 | { | |
359 | return ((unsigned char *) gnlh + GENL_HDRLEN); | |
360 | } | |
361 | ||
362 | /** | |
363 | * genlmsg_len - length of message payload | |
364 | * @gnlh: genetlink message header | |
365 | */ | |
366 | static inline int genlmsg_len(const struct genlmsghdr *gnlh) | |
367 | { | |
368 | struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - | |
369 | NLMSG_HDRLEN); | |
370 | return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); | |
371 | } | |
372 | ||
17db952c BS |
373 | /** |
374 | * genlmsg_msg_size - length of genetlink message not including padding | |
375 | * @payload: length of message payload | |
376 | */ | |
377 | static inline int genlmsg_msg_size(int payload) | |
378 | { | |
379 | return GENL_HDRLEN + payload; | |
380 | } | |
381 | ||
382 | /** | |
383 | * genlmsg_total_size - length of genetlink message including padding | |
384 | * @payload: length of message payload | |
385 | */ | |
386 | static inline int genlmsg_total_size(int payload) | |
387 | { | |
388 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
389 | } | |
390 | ||
3dabc715 TG |
391 | /** |
392 | * genlmsg_new - Allocate a new generic netlink message | |
393 | * @payload: size of the message payload | |
394 | * @flags: the type of memory to allocate. | |
395 | */ | |
396 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
397 | { | |
398 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
399 | } | |
400 | ||
62b68e99 JB |
401 | /** |
402 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 403 | * @family: the generic netlink family |
62b68e99 JB |
404 | * @net: the network namespace to report the error to |
405 | * @portid: the PORTID of a process that we want to skip (if any) | |
406 | * @group: the broadcast group that will notice the error | |
2a94fe48 | 407 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
408 | * @code: error code, must be negative (as usual in kernelspace) |
409 | * | |
410 | * This function returns the number of broadcast listeners that have set the | |
411 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
412 | */ | |
68eb5503 JB |
413 | static inline int genl_set_err(struct genl_family *family, struct net *net, |
414 | u32 portid, u32 group, int code) | |
62b68e99 | 415 | { |
91398a09 JB |
416 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
417 | return -EINVAL; | |
418 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
419 | return netlink_set_err(net->genl_sock, portid, group, code); |
420 | } | |
3dabc715 | 421 | |
0d566379 | 422 | static inline int genl_has_listeners(struct genl_family *family, |
f8403a2e | 423 | struct net *net, unsigned int group) |
0d566379 ND |
424 | { |
425 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) | |
426 | return -EINVAL; | |
427 | group = family->mcgrp_offset + group; | |
f8403a2e | 428 | return netlink_has_listeners(net->genl_sock, group); |
0d566379 | 429 | } |
482a8524 | 430 | #endif /* __NET_GENERIC_NETLINK_H */ |