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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]; |
2dbba6f7 JB |
17 | }; |
18 | ||
ff4c92d8 JB |
19 | struct genl_ops; |
20 | struct genl_info; | |
21 | ||
482a8524 TG |
22 | /** |
23 | * struct genl_family - generic netlink family | |
a07ea4d9 | 24 | * @id: protocol family identifier (private) |
482a8524 TG |
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 | |
3b0f31f2 | 29 | * @policy: netlink policy |
134e6375 JB |
30 | * @netnsok: set to true if the family can handle network |
31 | * namespaces and should be presented in all of them | |
f555f3d7 JB |
32 | * @parallel_ops: operations can be called in parallel and aren't |
33 | * synchronized by the core genetlink code | |
ff4c92d8 JB |
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 | |
c380d9a7 JB |
38 | * @mcast_bind: a socket bound to the given multicast group (which |
39 | * is given as the offset into the groups array) | |
ee1c2442 JB |
40 | * @mcast_unbind: a socket was unbound from the given multicast group. |
41 | * Note that unbind() will not be called symmetrically if the | |
42 | * generic netlink family is removed while there are still open | |
43 | * sockets. | |
489111e5 | 44 | * @attrbuf: buffer to store parsed attributes (private) |
489111e5 JB |
45 | * @mcgrps: multicast groups used by this family |
46 | * @n_mcgrps: number of multicast groups | |
2a94fe48 | 47 | * @mcgrp_offset: starting number of multicast group IDs in this family |
489111e5 JB |
48 | * (private) |
49 | * @ops: the operations supported by this family | |
50 | * @n_ops: number of operations supported by this family | |
482a8524 | 51 | */ |
fd2c3ef7 | 52 | struct genl_family { |
98e4321b | 53 | int id; /* private */ |
482a8524 TG |
54 | unsigned int hdrsize; |
55 | char name[GENL_NAMSIZ]; | |
56 | unsigned int version; | |
57 | unsigned int maxattr; | |
134e6375 | 58 | bool netnsok; |
def31174 | 59 | bool parallel_ops; |
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); | |
023e2cfa JB |
67 | int (*mcast_bind)(struct net *net, int group); |
68 | void (*mcast_unbind)(struct net *net, int group); | |
482a8524 | 69 | struct nlattr ** attrbuf; /* private */ |
489111e5 JB |
70 | const struct genl_ops * ops; |
71 | const struct genl_multicast_group *mcgrps; | |
72 | unsigned int n_ops; | |
73 | unsigned int n_mcgrps; | |
2a94fe48 | 74 | unsigned int mcgrp_offset; /* private */ |
33c6b1f6 | 75 | struct module *module; |
482a8524 TG |
76 | }; |
77 | ||
2ae0f17d | 78 | struct nlattr **genl_family_attrbuf(const struct genl_family *family); |
c90c39da | 79 | |
482a8524 TG |
80 | /** |
81 | * struct genl_info - receiving information | |
82 | * @snd_seq: sending sequence number | |
15e47304 | 83 | * @snd_portid: netlink portid of sender |
482a8524 TG |
84 | * @nlhdr: netlink message header |
85 | * @genlhdr: generic netlink message header | |
86 | * @userhdr: user specific header | |
87 | * @attrs: netlink attributes | |
ff4c92d8 JB |
88 | * @_net: network namespace |
89 | * @user_ptr: user pointers | |
7ab606d1 | 90 | * @extack: extended ACK report struct |
482a8524 | 91 | */ |
fd2c3ef7 | 92 | struct genl_info { |
482a8524 | 93 | u32 snd_seq; |
15e47304 | 94 | u32 snd_portid; |
482a8524 TG |
95 | struct nlmsghdr * nlhdr; |
96 | struct genlmsghdr * genlhdr; | |
97 | void * userhdr; | |
98 | struct nlattr ** attrs; | |
0c5c9fb5 | 99 | possible_net_t _net; |
ff4c92d8 | 100 | void * user_ptr[2]; |
7ab606d1 | 101 | struct netlink_ext_ack *extack; |
482a8524 TG |
102 | }; |
103 | ||
134e6375 JB |
104 | static inline struct net *genl_info_net(struct genl_info *info) |
105 | { | |
c2d9ba9b | 106 | return read_pnet(&info->_net); |
134e6375 JB |
107 | } |
108 | ||
109 | static inline void genl_info_net_set(struct genl_info *info, struct net *net) | |
110 | { | |
c2d9ba9b | 111 | write_pnet(&info->_net, net); |
134e6375 | 112 | } |
134e6375 | 113 | |
7ab606d1 JB |
114 | #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) |
115 | ||
116 | static inline int genl_err_attr(struct genl_info *info, int err, | |
6fce10f7 | 117 | const struct nlattr *attr) |
7ab606d1 JB |
118 | { |
119 | info->extack->bad_attr = attr; | |
120 | ||
121 | return err; | |
122 | } | |
123 | ||
ef6243ac JB |
124 | enum genl_validate_flags { |
125 | GENL_DONT_VALIDATE_STRICT = BIT(0), | |
126 | GENL_DONT_VALIDATE_DUMP = BIT(1), | |
127 | GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2), | |
128 | }; | |
129 | ||
482a8524 TG |
130 | /** |
131 | * struct genl_ops - generic netlink operations | |
132 | * @cmd: command identifier | |
ff4c92d8 | 133 | * @internal_flags: flags used by the family |
482a8524 | 134 | * @flags: flags |
482a8524 | 135 | * @doit: standard command callback |
fc9e50f5 | 136 | * @start: start callback for dumps |
482a8524 | 137 | * @dumpit: callback for dumpers |
a4d1366d | 138 | * @done: completion callback for dumps |
482a8524 | 139 | */ |
fd2c3ef7 | 140 | struct genl_ops { |
482a8524 TG |
141 | int (*doit)(struct sk_buff *skb, |
142 | struct genl_info *info); | |
fc9e50f5 | 143 | int (*start)(struct netlink_callback *cb); |
482a8524 TG |
144 | int (*dumpit)(struct sk_buff *skb, |
145 | struct netlink_callback *cb); | |
a4d1366d | 146 | int (*done)(struct netlink_callback *cb); |
3f5ccd06 JB |
147 | u8 cmd; |
148 | u8 internal_flags; | |
149 | u8 flags; | |
ef6243ac | 150 | u8 validate; |
482a8524 TG |
151 | }; |
152 | ||
489111e5 | 153 | int genl_register_family(struct genl_family *family); |
2ae0f17d JB |
154 | int genl_unregister_family(const struct genl_family *family); |
155 | void genl_notify(const struct genl_family *family, struct sk_buff *skb, | |
92c14d9b | 156 | struct genl_info *info, u32 group, gfp_t flags); |
482a8524 | 157 | |
15e47304 | 158 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
2ae0f17d | 159 | const struct genl_family *family, int flags, u8 cmd); |
482a8524 | 160 | |
670dc283 JB |
161 | /** |
162 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
163 | * @user_hdr: user header as returned from genlmsg_put() | |
670dc283 JB |
164 | * |
165 | * Returns pointer to netlink header. | |
166 | */ | |
0a833c29 | 167 | static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr) |
670dc283 JB |
168 | { |
169 | return (struct nlmsghdr *)((char *)user_hdr - | |
670dc283 JB |
170 | GENL_HDRLEN - |
171 | NLMSG_HDRLEN); | |
172 | } | |
173 | ||
7b1883ce | 174 | /** |
8cb08174 | 175 | * genlmsg_parse_deprecated - parse attributes of a genetlink message |
7b1883ce JS |
176 | * @nlh: netlink message header |
177 | * @family: genetlink message family | |
178 | * @tb: destination array with maxtype+1 elements | |
179 | * @maxtype: maximum attribute type to be expected | |
180 | * @policy: validation policy | |
fceb6435 JB |
181 | * @extack: extended ACK report struct |
182 | */ | |
8cb08174 JB |
183 | static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh, |
184 | const struct genl_family *family, | |
185 | struct nlattr *tb[], int maxtype, | |
186 | const struct nla_policy *policy, | |
187 | struct netlink_ext_ack *extack) | |
7b1883ce | 188 | { |
8cb08174 JB |
189 | return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, |
190 | policy, NL_VALIDATE_LIBERAL, extack); | |
7b1883ce JS |
191 | } |
192 | ||
3de64403 JB |
193 | /** |
194 | * genlmsg_parse - parse attributes of a genetlink message | |
195 | * @nlh: netlink message header | |
196 | * @family: genetlink message family | |
197 | * @tb: destination array with maxtype+1 elements | |
198 | * @maxtype: maximum attribute type to be expected | |
199 | * @policy: validation policy | |
200 | * @extack: extended ACK report struct | |
201 | */ | |
202 | static inline int genlmsg_parse(const struct nlmsghdr *nlh, | |
203 | const struct genl_family *family, | |
204 | struct nlattr *tb[], int maxtype, | |
205 | const struct nla_policy *policy, | |
206 | struct netlink_ext_ack *extack) | |
207 | { | |
208 | return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, | |
209 | policy, NL_VALIDATE_STRICT, extack); | |
210 | } | |
211 | ||
670dc283 JB |
212 | /** |
213 | * genl_dump_check_consistent - check if sequence is consistent and advertise if not | |
214 | * @cb: netlink callback structure that stores the sequence number | |
215 | * @user_hdr: user header as returned from genlmsg_put() | |
670dc283 JB |
216 | * |
217 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
218 | * simpler to use with generic netlink. | |
219 | */ | |
220 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
0a833c29 | 221 | void *user_hdr) |
670dc283 | 222 | { |
0a833c29 | 223 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr)); |
670dc283 JB |
224 | } |
225 | ||
17c157c8 TG |
226 | /** |
227 | * genlmsg_put_reply - Add generic netlink header to a reply message | |
228 | * @skb: socket buffer holding the message | |
229 | * @info: receiver info | |
230 | * @family: generic netlink family | |
231 | * @flags: netlink message flags | |
232 | * @cmd: generic netlink command | |
233 | * | |
234 | * Returns pointer to user specific header | |
235 | */ | |
236 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
237 | struct genl_info *info, | |
2ae0f17d | 238 | const struct genl_family *family, |
17c157c8 TG |
239 | int flags, u8 cmd) |
240 | { | |
15e47304 | 241 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
242 | flags, cmd); |
243 | } | |
244 | ||
482a8524 TG |
245 | /** |
246 | * genlmsg_end - Finalize a generic netlink message | |
247 | * @skb: socket buffer the message is stored in | |
248 | * @hdr: user specific header | |
249 | */ | |
053c095a | 250 | static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
482a8524 | 251 | { |
053c095a | 252 | nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
482a8524 TG |
253 | } |
254 | ||
255 | /** | |
256 | * genlmsg_cancel - Cancel construction of a generic netlink message | |
257 | * @skb: socket buffer the message is stored in | |
258 | * @hdr: generic netlink message header | |
259 | */ | |
bc3ed28c | 260 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 261 | { |
38db9e1d JL |
262 | if (hdr) |
263 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
264 | } |
265 | ||
266 | /** | |
134e6375 | 267 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 268 | * @family: the generic netlink family |
134e6375 JB |
269 | * @net: the net namespace |
270 | * @skb: netlink message as socket buffer | |
15e47304 | 271 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 272 | * @group: offset of multicast group in groups array |
134e6375 JB |
273 | * @flags: allocation flags |
274 | */ | |
2ae0f17d | 275 | static inline int genlmsg_multicast_netns(const struct genl_family *family, |
68eb5503 | 276 | struct net *net, struct sk_buff *skb, |
15e47304 | 277 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 278 | { |
220815a9 | 279 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
280 | return -EINVAL; |
281 | group = family->mcgrp_offset + group; | |
15e47304 | 282 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
283 | } |
284 | ||
285 | /** | |
286 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 287 | * @family: the generic netlink family |
482a8524 | 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 |
d387f6ad | 291 | * @flags: allocation flags |
482a8524 | 292 | */ |
2ae0f17d | 293 | static inline int genlmsg_multicast(const struct genl_family *family, |
68eb5503 | 294 | struct sk_buff *skb, u32 portid, |
d387f6ad | 295 | unsigned int group, gfp_t flags) |
482a8524 | 296 | { |
68eb5503 JB |
297 | return genlmsg_multicast_netns(family, &init_net, skb, |
298 | portid, group, flags); | |
482a8524 TG |
299 | } |
300 | ||
134e6375 JB |
301 | /** |
302 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 303 | * @family: the generic netlink family |
134e6375 | 304 | * @skb: netlink message as socket buffer |
15e47304 | 305 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 306 | * @group: offset of multicast group in groups array |
134e6375 JB |
307 | * @flags: allocation flags |
308 | * | |
309 | * This function must hold the RTNL or rcu_read_lock(). | |
310 | */ | |
2ae0f17d | 311 | int genlmsg_multicast_allns(const struct genl_family *family, |
68eb5503 | 312 | struct sk_buff *skb, u32 portid, |
134e6375 JB |
313 | unsigned int group, gfp_t flags); |
314 | ||
482a8524 TG |
315 | /** |
316 | * genlmsg_unicast - unicast a netlink message | |
317 | * @skb: netlink message as socket buffer | |
15e47304 | 318 | * @portid: netlink portid of the destination socket |
482a8524 | 319 | */ |
15e47304 | 320 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 321 | { |
15e47304 | 322 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
323 | } |
324 | ||
81878d27 TG |
325 | /** |
326 | * genlmsg_reply - reply to a request | |
327 | * @skb: netlink message to be sent back | |
328 | * @info: receiver information | |
329 | */ | |
330 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
331 | { | |
15e47304 | 332 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
333 | } |
334 | ||
fb0ba6bd BS |
335 | /** |
336 | * gennlmsg_data - head of message payload | |
70f23fd6 | 337 | * @gnlh: genetlink message header |
fb0ba6bd BS |
338 | */ |
339 | static inline void *genlmsg_data(const struct genlmsghdr *gnlh) | |
340 | { | |
341 | return ((unsigned char *) gnlh + GENL_HDRLEN); | |
342 | } | |
343 | ||
344 | /** | |
345 | * genlmsg_len - length of message payload | |
346 | * @gnlh: genetlink message header | |
347 | */ | |
348 | static inline int genlmsg_len(const struct genlmsghdr *gnlh) | |
349 | { | |
350 | struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - | |
351 | NLMSG_HDRLEN); | |
352 | return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); | |
353 | } | |
354 | ||
17db952c BS |
355 | /** |
356 | * genlmsg_msg_size - length of genetlink message not including padding | |
357 | * @payload: length of message payload | |
358 | */ | |
359 | static inline int genlmsg_msg_size(int payload) | |
360 | { | |
361 | return GENL_HDRLEN + payload; | |
362 | } | |
363 | ||
364 | /** | |
365 | * genlmsg_total_size - length of genetlink message including padding | |
366 | * @payload: length of message payload | |
367 | */ | |
368 | static inline int genlmsg_total_size(int payload) | |
369 | { | |
370 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
371 | } | |
372 | ||
3dabc715 TG |
373 | /** |
374 | * genlmsg_new - Allocate a new generic netlink message | |
375 | * @payload: size of the message payload | |
376 | * @flags: the type of memory to allocate. | |
377 | */ | |
378 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
379 | { | |
380 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
381 | } | |
382 | ||
62b68e99 JB |
383 | /** |
384 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 385 | * @family: the generic netlink family |
62b68e99 JB |
386 | * @net: the network namespace to report the error to |
387 | * @portid: the PORTID of a process that we want to skip (if any) | |
388 | * @group: the broadcast group that will notice the error | |
2a94fe48 | 389 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
390 | * @code: error code, must be negative (as usual in kernelspace) |
391 | * | |
392 | * This function returns the number of broadcast listeners that have set the | |
393 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
394 | */ | |
2ae0f17d JB |
395 | static inline int genl_set_err(const struct genl_family *family, |
396 | struct net *net, u32 portid, | |
397 | u32 group, int code) | |
62b68e99 | 398 | { |
91398a09 JB |
399 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
400 | return -EINVAL; | |
401 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
402 | return netlink_set_err(net->genl_sock, portid, group, code); |
403 | } | |
3dabc715 | 404 | |
2ae0f17d | 405 | static inline int genl_has_listeners(const struct genl_family *family, |
f8403a2e | 406 | struct net *net, unsigned int group) |
0d566379 ND |
407 | { |
408 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) | |
409 | return -EINVAL; | |
410 | group = family->mcgrp_offset + group; | |
f8403a2e | 411 | return netlink_has_listeners(net->genl_sock, group); |
0d566379 | 412 | } |
482a8524 | 413 | #endif /* __NET_GENERIC_NETLINK_H */ |