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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 | |
ff4c92d8 JB |
30 | * @pre_doit: called before an operation's doit callback, it may |
31 | * do additional, common, filtering and return an error | |
32 | * @post_doit: called after an operation's doit callback, it may | |
33 | * undo operations done by pre_doit, for example release locks | |
482a8524 | 34 | * @attrbuf: buffer to store parsed attributes |
482a8524 | 35 | * @family_list: family list |
2a94fe48 JB |
36 | * @mcgrps: multicast groups used by this family (private) |
37 | * @n_mcgrps: number of multicast groups (private) | |
38 | * @mcgrp_offset: starting number of multicast group IDs in this family | |
d91824c0 JB |
39 | * @ops: the operations supported by this family (private) |
40 | * @n_ops: number of operations supported by this family (private) | |
482a8524 | 41 | */ |
fd2c3ef7 | 42 | struct genl_family { |
482a8524 TG |
43 | unsigned int id; |
44 | unsigned int hdrsize; | |
45 | char name[GENL_NAMSIZ]; | |
46 | unsigned int version; | |
47 | unsigned int maxattr; | |
134e6375 | 48 | bool netnsok; |
def31174 | 49 | bool parallel_ops; |
f84f771d | 50 | int (*pre_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
51 | struct sk_buff *skb, |
52 | struct genl_info *info); | |
f84f771d | 53 | void (*post_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
54 | struct sk_buff *skb, |
55 | struct genl_info *info); | |
482a8524 | 56 | struct nlattr ** attrbuf; /* private */ |
f84f771d | 57 | const struct genl_ops * ops; /* private */ |
2a94fe48 | 58 | const struct genl_multicast_group *mcgrps; /* private */ |
d91824c0 | 59 | unsigned int n_ops; /* private */ |
2a94fe48 JB |
60 | unsigned int n_mcgrps; /* private */ |
61 | unsigned int mcgrp_offset; /* private */ | |
482a8524 | 62 | struct list_head family_list; /* private */ |
33c6b1f6 | 63 | struct module *module; |
482a8524 TG |
64 | }; |
65 | ||
482a8524 TG |
66 | /** |
67 | * struct genl_info - receiving information | |
68 | * @snd_seq: sending sequence number | |
15e47304 | 69 | * @snd_portid: netlink portid of sender |
482a8524 TG |
70 | * @nlhdr: netlink message header |
71 | * @genlhdr: generic netlink message header | |
72 | * @userhdr: user specific header | |
73 | * @attrs: netlink attributes | |
ff4c92d8 JB |
74 | * @_net: network namespace |
75 | * @user_ptr: user pointers | |
482a8524 | 76 | */ |
fd2c3ef7 | 77 | struct genl_info { |
482a8524 | 78 | u32 snd_seq; |
15e47304 | 79 | u32 snd_portid; |
482a8524 TG |
80 | struct nlmsghdr * nlhdr; |
81 | struct genlmsghdr * genlhdr; | |
82 | void * userhdr; | |
83 | struct nlattr ** attrs; | |
134e6375 JB |
84 | #ifdef CONFIG_NET_NS |
85 | struct net * _net; | |
86 | #endif | |
ff4c92d8 | 87 | void * user_ptr[2]; |
482a8524 TG |
88 | }; |
89 | ||
134e6375 JB |
90 | static inline struct net *genl_info_net(struct genl_info *info) |
91 | { | |
c2d9ba9b | 92 | return read_pnet(&info->_net); |
134e6375 JB |
93 | } |
94 | ||
95 | static inline void genl_info_net_set(struct genl_info *info, struct net *net) | |
96 | { | |
c2d9ba9b | 97 | write_pnet(&info->_net, net); |
134e6375 | 98 | } |
134e6375 | 99 | |
482a8524 TG |
100 | /** |
101 | * struct genl_ops - generic netlink operations | |
102 | * @cmd: command identifier | |
ff4c92d8 | 103 | * @internal_flags: flags used by the family |
482a8524 TG |
104 | * @flags: flags |
105 | * @policy: attribute validation policy | |
106 | * @doit: standard command callback | |
107 | * @dumpit: callback for dumpers | |
a4d1366d | 108 | * @done: completion callback for dumps |
482a8524 TG |
109 | * @ops_list: operations list |
110 | */ | |
fd2c3ef7 | 111 | struct genl_ops { |
ef7c79ed | 112 | const struct nla_policy *policy; |
482a8524 TG |
113 | int (*doit)(struct sk_buff *skb, |
114 | struct genl_info *info); | |
115 | int (*dumpit)(struct sk_buff *skb, | |
116 | struct netlink_callback *cb); | |
a4d1366d | 117 | int (*done)(struct netlink_callback *cb); |
3f5ccd06 JB |
118 | u8 cmd; |
119 | u8 internal_flags; | |
120 | u8 flags; | |
482a8524 TG |
121 | }; |
122 | ||
ff2b94d2 | 123 | int __genl_register_family(struct genl_family *family); |
33c6b1f6 PS |
124 | |
125 | static inline int genl_register_family(struct genl_family *family) | |
126 | { | |
127 | family->module = THIS_MODULE; | |
128 | return __genl_register_family(family); | |
129 | } | |
130 | ||
568508aa JB |
131 | /** |
132 | * genl_register_family_with_ops - register a generic netlink family with ops | |
133 | * @family: generic netlink family | |
134 | * @ops: operations to be registered | |
135 | * @n_ops: number of elements to register | |
136 | * | |
137 | * Registers the specified family and operations from the specified table. | |
138 | * Only one family may be registered with the same family name or identifier. | |
139 | * | |
140 | * The family id may equal GENL_ID_GENERATE causing an unique id to | |
141 | * be automatically generated and assigned. | |
142 | * | |
143 | * Either a doit or dumpit callback must be specified for every registered | |
144 | * operation or the function will fail. Only one operation structure per | |
145 | * command identifier may be registered. | |
146 | * | |
147 | * See include/net/genetlink.h for more documenation on the operations | |
148 | * structure. | |
149 | * | |
150 | * Return 0 on success or a negative error code. | |
151 | */ | |
2a94fe48 JB |
152 | static inline int |
153 | _genl_register_family_with_ops_grps(struct genl_family *family, | |
154 | const struct genl_ops *ops, size_t n_ops, | |
155 | const struct genl_multicast_group *mcgrps, | |
156 | size_t n_mcgrps) | |
33c6b1f6 PS |
157 | { |
158 | family->module = THIS_MODULE; | |
568508aa JB |
159 | family->ops = ops; |
160 | family->n_ops = n_ops; | |
2a94fe48 JB |
161 | family->mcgrps = mcgrps; |
162 | family->n_mcgrps = n_mcgrps; | |
568508aa | 163 | return __genl_register_family(family); |
33c6b1f6 PS |
164 | } |
165 | ||
2a94fe48 JB |
166 | #define genl_register_family_with_ops(family, ops) \ |
167 | _genl_register_family_with_ops_grps((family), \ | |
168 | (ops), ARRAY_SIZE(ops), \ | |
169 | NULL, 0) | |
170 | #define genl_register_family_with_ops_groups(family, ops, grps) \ | |
171 | _genl_register_family_with_ops_grps((family), \ | |
172 | (ops), ARRAY_SIZE(ops), \ | |
173 | (grps), ARRAY_SIZE(grps)) | |
c53ed742 | 174 | |
ff2b94d2 | 175 | int genl_unregister_family(struct genl_family *family); |
68eb5503 JB |
176 | void genl_notify(struct genl_family *family, |
177 | struct sk_buff *skb, struct net *net, u32 portid, | |
ff2b94d2 | 178 | u32 group, struct nlmsghdr *nlh, gfp_t flags); |
482a8524 | 179 | |
15e47304 | 180 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
ff2b94d2 | 181 | struct genl_family *family, int flags, u8 cmd); |
482a8524 | 182 | |
670dc283 JB |
183 | /** |
184 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
185 | * @user_hdr: user header as returned from genlmsg_put() | |
186 | * @family: generic netlink family | |
187 | * | |
188 | * Returns pointer to netlink header. | |
189 | */ | |
190 | static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr, | |
191 | struct genl_family *family) | |
192 | { | |
193 | return (struct nlmsghdr *)((char *)user_hdr - | |
194 | family->hdrsize - | |
195 | GENL_HDRLEN - | |
196 | NLMSG_HDRLEN); | |
197 | } | |
198 | ||
199 | /** | |
200 | * genl_dump_check_consistent - check if sequence is consistent and advertise if not | |
201 | * @cb: netlink callback structure that stores the sequence number | |
202 | * @user_hdr: user header as returned from genlmsg_put() | |
203 | * @family: generic netlink family | |
204 | * | |
205 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
206 | * simpler to use with generic netlink. | |
207 | */ | |
208 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
209 | void *user_hdr, | |
210 | struct genl_family *family) | |
211 | { | |
212 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family)); | |
213 | } | |
214 | ||
17c157c8 TG |
215 | /** |
216 | * genlmsg_put_reply - Add generic netlink header to a reply message | |
217 | * @skb: socket buffer holding the message | |
218 | * @info: receiver info | |
219 | * @family: generic netlink family | |
220 | * @flags: netlink message flags | |
221 | * @cmd: generic netlink command | |
222 | * | |
223 | * Returns pointer to user specific header | |
224 | */ | |
225 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
226 | struct genl_info *info, | |
227 | struct genl_family *family, | |
228 | int flags, u8 cmd) | |
229 | { | |
15e47304 | 230 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
231 | flags, cmd); |
232 | } | |
233 | ||
482a8524 TG |
234 | /** |
235 | * genlmsg_end - Finalize a generic netlink message | |
236 | * @skb: socket buffer the message is stored in | |
237 | * @hdr: user specific header | |
238 | */ | |
239 | static inline int genlmsg_end(struct sk_buff *skb, void *hdr) | |
240 | { | |
241 | return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
242 | } | |
243 | ||
244 | /** | |
245 | * genlmsg_cancel - Cancel construction of a generic netlink message | |
246 | * @skb: socket buffer the message is stored in | |
247 | * @hdr: generic netlink message header | |
248 | */ | |
bc3ed28c | 249 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 250 | { |
38db9e1d JL |
251 | if (hdr) |
252 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
253 | } |
254 | ||
255 | /** | |
134e6375 | 256 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 257 | * @family: the generic netlink family |
134e6375 JB |
258 | * @net: the net namespace |
259 | * @skb: netlink message as socket buffer | |
15e47304 | 260 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 261 | * @group: offset of multicast group in groups array |
134e6375 JB |
262 | * @flags: allocation flags |
263 | */ | |
68eb5503 JB |
264 | static inline int genlmsg_multicast_netns(struct genl_family *family, |
265 | struct net *net, struct sk_buff *skb, | |
15e47304 | 266 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 267 | { |
220815a9 | 268 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
269 | return -EINVAL; |
270 | group = family->mcgrp_offset + group; | |
15e47304 | 271 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
272 | } |
273 | ||
274 | /** | |
275 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 276 | * @family: the generic netlink family |
482a8524 | 277 | * @skb: netlink message as socket buffer |
15e47304 | 278 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 279 | * @group: offset of multicast group in groups array |
d387f6ad | 280 | * @flags: allocation flags |
482a8524 | 281 | */ |
68eb5503 JB |
282 | static inline int genlmsg_multicast(struct genl_family *family, |
283 | struct sk_buff *skb, u32 portid, | |
d387f6ad | 284 | unsigned int group, gfp_t flags) |
482a8524 | 285 | { |
68eb5503 JB |
286 | return genlmsg_multicast_netns(family, &init_net, skb, |
287 | portid, group, flags); | |
482a8524 TG |
288 | } |
289 | ||
134e6375 JB |
290 | /** |
291 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 292 | * @family: the generic netlink family |
134e6375 | 293 | * @skb: netlink message as socket buffer |
15e47304 | 294 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 295 | * @group: offset of multicast group in groups array |
134e6375 JB |
296 | * @flags: allocation flags |
297 | * | |
298 | * This function must hold the RTNL or rcu_read_lock(). | |
299 | */ | |
68eb5503 JB |
300 | int genlmsg_multicast_allns(struct genl_family *family, |
301 | struct sk_buff *skb, u32 portid, | |
134e6375 JB |
302 | unsigned int group, gfp_t flags); |
303 | ||
482a8524 TG |
304 | /** |
305 | * genlmsg_unicast - unicast a netlink message | |
306 | * @skb: netlink message as socket buffer | |
15e47304 | 307 | * @portid: netlink portid of the destination socket |
482a8524 | 308 | */ |
15e47304 | 309 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 310 | { |
15e47304 | 311 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
312 | } |
313 | ||
81878d27 TG |
314 | /** |
315 | * genlmsg_reply - reply to a request | |
316 | * @skb: netlink message to be sent back | |
317 | * @info: receiver information | |
318 | */ | |
319 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
320 | { | |
15e47304 | 321 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
322 | } |
323 | ||
fb0ba6bd BS |
324 | /** |
325 | * gennlmsg_data - head of message payload | |
70f23fd6 | 326 | * @gnlh: genetlink message header |
fb0ba6bd BS |
327 | */ |
328 | static inline void *genlmsg_data(const struct genlmsghdr *gnlh) | |
329 | { | |
330 | return ((unsigned char *) gnlh + GENL_HDRLEN); | |
331 | } | |
332 | ||
333 | /** | |
334 | * genlmsg_len - length of message payload | |
335 | * @gnlh: genetlink message header | |
336 | */ | |
337 | static inline int genlmsg_len(const struct genlmsghdr *gnlh) | |
338 | { | |
339 | struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - | |
340 | NLMSG_HDRLEN); | |
341 | return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); | |
342 | } | |
343 | ||
17db952c BS |
344 | /** |
345 | * genlmsg_msg_size - length of genetlink message not including padding | |
346 | * @payload: length of message payload | |
347 | */ | |
348 | static inline int genlmsg_msg_size(int payload) | |
349 | { | |
350 | return GENL_HDRLEN + payload; | |
351 | } | |
352 | ||
353 | /** | |
354 | * genlmsg_total_size - length of genetlink message including padding | |
355 | * @payload: length of message payload | |
356 | */ | |
357 | static inline int genlmsg_total_size(int payload) | |
358 | { | |
359 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
360 | } | |
361 | ||
3dabc715 TG |
362 | /** |
363 | * genlmsg_new - Allocate a new generic netlink message | |
364 | * @payload: size of the message payload | |
365 | * @flags: the type of memory to allocate. | |
366 | */ | |
367 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
368 | { | |
369 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
370 | } | |
371 | ||
62b68e99 JB |
372 | /** |
373 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 374 | * @family: the generic netlink family |
62b68e99 JB |
375 | * @net: the network namespace to report the error to |
376 | * @portid: the PORTID of a process that we want to skip (if any) | |
377 | * @group: the broadcast group that will notice the error | |
2a94fe48 | 378 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
379 | * @code: error code, must be negative (as usual in kernelspace) |
380 | * | |
381 | * This function returns the number of broadcast listeners that have set the | |
382 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
383 | */ | |
68eb5503 JB |
384 | static inline int genl_set_err(struct genl_family *family, struct net *net, |
385 | u32 portid, u32 group, int code) | |
62b68e99 | 386 | { |
91398a09 JB |
387 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
388 | return -EINVAL; | |
389 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
390 | return netlink_set_err(net->genl_sock, portid, group, code); |
391 | } | |
3dabc715 | 392 | |
482a8524 | 393 | #endif /* __NET_GENERIC_NETLINK_H */ |