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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 | |
134e6375 JB |
29 | * @netnsok: set to true if the family can handle network |
30 | * namespaces and should be presented in all of them | |
f555f3d7 JB |
31 | * @parallel_ops: operations can be called in parallel and aren't |
32 | * synchronized by the core genetlink code | |
ff4c92d8 JB |
33 | * @pre_doit: called before an operation's doit callback, it may |
34 | * do additional, common, filtering and return an error | |
35 | * @post_doit: called after an operation's doit callback, it may | |
36 | * undo operations done by pre_doit, for example release locks | |
c380d9a7 JB |
37 | * @mcast_bind: a socket bound to the given multicast group (which |
38 | * is given as the offset into the groups array) | |
ee1c2442 JB |
39 | * @mcast_unbind: a socket was unbound from the given multicast group. |
40 | * Note that unbind() will not be called symmetrically if the | |
41 | * generic netlink family is removed while there are still open | |
42 | * sockets. | |
489111e5 | 43 | * @attrbuf: buffer to store parsed attributes (private) |
489111e5 JB |
44 | * @mcgrps: multicast groups used by this family |
45 | * @n_mcgrps: number of multicast groups | |
2a94fe48 | 46 | * @mcgrp_offset: starting number of multicast group IDs in this family |
489111e5 JB |
47 | * (private) |
48 | * @ops: the operations supported by this family | |
49 | * @n_ops: number of operations supported by this family | |
482a8524 | 50 | */ |
fd2c3ef7 | 51 | struct genl_family { |
98e4321b | 52 | int id; /* private */ |
482a8524 TG |
53 | unsigned int hdrsize; |
54 | char name[GENL_NAMSIZ]; | |
55 | unsigned int version; | |
56 | unsigned int maxattr; | |
134e6375 | 57 | bool netnsok; |
def31174 | 58 | bool parallel_ops; |
f84f771d | 59 | int (*pre_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
60 | struct sk_buff *skb, |
61 | struct genl_info *info); | |
f84f771d | 62 | void (*post_doit)(const struct genl_ops *ops, |
ff4c92d8 JB |
63 | struct sk_buff *skb, |
64 | struct genl_info *info); | |
023e2cfa JB |
65 | int (*mcast_bind)(struct net *net, int group); |
66 | void (*mcast_unbind)(struct net *net, int group); | |
482a8524 | 67 | struct nlattr ** attrbuf; /* private */ |
489111e5 JB |
68 | const struct genl_ops * ops; |
69 | const struct genl_multicast_group *mcgrps; | |
70 | unsigned int n_ops; | |
71 | unsigned int n_mcgrps; | |
2a94fe48 | 72 | unsigned int mcgrp_offset; /* private */ |
33c6b1f6 | 73 | struct module *module; |
482a8524 TG |
74 | }; |
75 | ||
2ae0f17d | 76 | struct nlattr **genl_family_attrbuf(const struct genl_family *family); |
c90c39da | 77 | |
482a8524 TG |
78 | /** |
79 | * struct genl_info - receiving information | |
80 | * @snd_seq: sending sequence number | |
15e47304 | 81 | * @snd_portid: netlink portid of sender |
482a8524 TG |
82 | * @nlhdr: netlink message header |
83 | * @genlhdr: generic netlink message header | |
84 | * @userhdr: user specific header | |
85 | * @attrs: netlink attributes | |
ff4c92d8 JB |
86 | * @_net: network namespace |
87 | * @user_ptr: user pointers | |
7ab606d1 | 88 | * @extack: extended ACK report struct |
482a8524 | 89 | */ |
fd2c3ef7 | 90 | struct genl_info { |
482a8524 | 91 | u32 snd_seq; |
15e47304 | 92 | u32 snd_portid; |
482a8524 TG |
93 | struct nlmsghdr * nlhdr; |
94 | struct genlmsghdr * genlhdr; | |
95 | void * userhdr; | |
96 | struct nlattr ** attrs; | |
0c5c9fb5 | 97 | possible_net_t _net; |
ff4c92d8 | 98 | void * user_ptr[2]; |
7ab606d1 | 99 | struct netlink_ext_ack *extack; |
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 | |
7ab606d1 JB |
112 | #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) |
113 | ||
114 | static inline int genl_err_attr(struct genl_info *info, int err, | |
6fce10f7 | 115 | const struct nlattr *attr) |
7ab606d1 JB |
116 | { |
117 | info->extack->bad_attr = attr; | |
118 | ||
119 | return err; | |
120 | } | |
121 | ||
482a8524 TG |
122 | /** |
123 | * struct genl_ops - generic netlink operations | |
124 | * @cmd: command identifier | |
ff4c92d8 | 125 | * @internal_flags: flags used by the family |
482a8524 TG |
126 | * @flags: flags |
127 | * @policy: attribute validation policy | |
128 | * @doit: standard command callback | |
fc9e50f5 | 129 | * @start: start callback for dumps |
482a8524 | 130 | * @dumpit: callback for dumpers |
a4d1366d | 131 | * @done: completion callback for dumps |
482a8524 | 132 | */ |
fd2c3ef7 | 133 | struct genl_ops { |
ef7c79ed | 134 | const struct nla_policy *policy; |
482a8524 TG |
135 | int (*doit)(struct sk_buff *skb, |
136 | struct genl_info *info); | |
fc9e50f5 | 137 | int (*start)(struct netlink_callback *cb); |
482a8524 TG |
138 | int (*dumpit)(struct sk_buff *skb, |
139 | struct netlink_callback *cb); | |
a4d1366d | 140 | int (*done)(struct netlink_callback *cb); |
3f5ccd06 JB |
141 | u8 cmd; |
142 | u8 internal_flags; | |
143 | u8 flags; | |
482a8524 TG |
144 | }; |
145 | ||
489111e5 | 146 | int genl_register_family(struct genl_family *family); |
2ae0f17d JB |
147 | int genl_unregister_family(const struct genl_family *family); |
148 | void genl_notify(const struct genl_family *family, struct sk_buff *skb, | |
92c14d9b | 149 | struct genl_info *info, u32 group, gfp_t flags); |
482a8524 | 150 | |
15e47304 | 151 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
2ae0f17d | 152 | const struct genl_family *family, int flags, u8 cmd); |
482a8524 | 153 | |
670dc283 JB |
154 | /** |
155 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
156 | * @user_hdr: user header as returned from genlmsg_put() | |
670dc283 JB |
157 | * |
158 | * Returns pointer to netlink header. | |
159 | */ | |
0a833c29 | 160 | static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr) |
670dc283 JB |
161 | { |
162 | return (struct nlmsghdr *)((char *)user_hdr - | |
670dc283 JB |
163 | GENL_HDRLEN - |
164 | NLMSG_HDRLEN); | |
165 | } | |
166 | ||
7b1883ce JS |
167 | /** |
168 | * genlmsg_parse - parse attributes of a genetlink message | |
169 | * @nlh: netlink message header | |
170 | * @family: genetlink message family | |
171 | * @tb: destination array with maxtype+1 elements | |
172 | * @maxtype: maximum attribute type to be expected | |
173 | * @policy: validation policy | |
fceb6435 JB |
174 | * @extack: extended ACK report struct |
175 | */ | |
7b1883ce JS |
176 | static inline int genlmsg_parse(const struct nlmsghdr *nlh, |
177 | const struct genl_family *family, | |
178 | struct nlattr *tb[], int maxtype, | |
fceb6435 JB |
179 | const struct nla_policy *policy, |
180 | struct netlink_ext_ack *extack) | |
7b1883ce JS |
181 | { |
182 | return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, | |
fceb6435 | 183 | policy, extack); |
7b1883ce JS |
184 | } |
185 | ||
670dc283 JB |
186 | /** |
187 | * genl_dump_check_consistent - check if sequence is consistent and advertise if not | |
188 | * @cb: netlink callback structure that stores the sequence number | |
189 | * @user_hdr: user header as returned from genlmsg_put() | |
670dc283 JB |
190 | * |
191 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
192 | * simpler to use with generic netlink. | |
193 | */ | |
194 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
0a833c29 | 195 | void *user_hdr) |
670dc283 | 196 | { |
0a833c29 | 197 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr)); |
670dc283 JB |
198 | } |
199 | ||
17c157c8 TG |
200 | /** |
201 | * genlmsg_put_reply - Add generic netlink header to a reply message | |
202 | * @skb: socket buffer holding the message | |
203 | * @info: receiver info | |
204 | * @family: generic netlink family | |
205 | * @flags: netlink message flags | |
206 | * @cmd: generic netlink command | |
207 | * | |
208 | * Returns pointer to user specific header | |
209 | */ | |
210 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
211 | struct genl_info *info, | |
2ae0f17d | 212 | const struct genl_family *family, |
17c157c8 TG |
213 | int flags, u8 cmd) |
214 | { | |
15e47304 | 215 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
216 | flags, cmd); |
217 | } | |
218 | ||
482a8524 TG |
219 | /** |
220 | * genlmsg_end - Finalize a generic netlink message | |
221 | * @skb: socket buffer the message is stored in | |
222 | * @hdr: user specific header | |
223 | */ | |
053c095a | 224 | static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
482a8524 | 225 | { |
053c095a | 226 | nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
482a8524 TG |
227 | } |
228 | ||
229 | /** | |
230 | * genlmsg_cancel - Cancel construction of a generic netlink message | |
231 | * @skb: socket buffer the message is stored in | |
232 | * @hdr: generic netlink message header | |
233 | */ | |
bc3ed28c | 234 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 235 | { |
38db9e1d JL |
236 | if (hdr) |
237 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
238 | } |
239 | ||
240 | /** | |
134e6375 | 241 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 242 | * @family: the generic netlink family |
134e6375 JB |
243 | * @net: the net namespace |
244 | * @skb: netlink message as socket buffer | |
15e47304 | 245 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 246 | * @group: offset of multicast group in groups array |
134e6375 JB |
247 | * @flags: allocation flags |
248 | */ | |
2ae0f17d | 249 | static inline int genlmsg_multicast_netns(const struct genl_family *family, |
68eb5503 | 250 | struct net *net, struct sk_buff *skb, |
15e47304 | 251 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 252 | { |
220815a9 | 253 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
254 | return -EINVAL; |
255 | group = family->mcgrp_offset + group; | |
15e47304 | 256 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
257 | } |
258 | ||
259 | /** | |
260 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 261 | * @family: the generic netlink family |
482a8524 | 262 | * @skb: netlink message as socket buffer |
15e47304 | 263 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 264 | * @group: offset of multicast group in groups array |
d387f6ad | 265 | * @flags: allocation flags |
482a8524 | 266 | */ |
2ae0f17d | 267 | static inline int genlmsg_multicast(const struct genl_family *family, |
68eb5503 | 268 | struct sk_buff *skb, u32 portid, |
d387f6ad | 269 | unsigned int group, gfp_t flags) |
482a8524 | 270 | { |
68eb5503 JB |
271 | return genlmsg_multicast_netns(family, &init_net, skb, |
272 | portid, group, flags); | |
482a8524 TG |
273 | } |
274 | ||
134e6375 JB |
275 | /** |
276 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 277 | * @family: the generic netlink family |
134e6375 | 278 | * @skb: netlink message as socket buffer |
15e47304 | 279 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 280 | * @group: offset of multicast group in groups array |
134e6375 JB |
281 | * @flags: allocation flags |
282 | * | |
283 | * This function must hold the RTNL or rcu_read_lock(). | |
284 | */ | |
2ae0f17d | 285 | int genlmsg_multicast_allns(const struct genl_family *family, |
68eb5503 | 286 | struct sk_buff *skb, u32 portid, |
134e6375 JB |
287 | unsigned int group, gfp_t flags); |
288 | ||
482a8524 TG |
289 | /** |
290 | * genlmsg_unicast - unicast a netlink message | |
291 | * @skb: netlink message as socket buffer | |
15e47304 | 292 | * @portid: netlink portid of the destination socket |
482a8524 | 293 | */ |
15e47304 | 294 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 295 | { |
15e47304 | 296 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
297 | } |
298 | ||
81878d27 TG |
299 | /** |
300 | * genlmsg_reply - reply to a request | |
301 | * @skb: netlink message to be sent back | |
302 | * @info: receiver information | |
303 | */ | |
304 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
305 | { | |
15e47304 | 306 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
307 | } |
308 | ||
fb0ba6bd BS |
309 | /** |
310 | * gennlmsg_data - head of message payload | |
70f23fd6 | 311 | * @gnlh: genetlink message header |
fb0ba6bd BS |
312 | */ |
313 | static inline void *genlmsg_data(const struct genlmsghdr *gnlh) | |
314 | { | |
315 | return ((unsigned char *) gnlh + GENL_HDRLEN); | |
316 | } | |
317 | ||
318 | /** | |
319 | * genlmsg_len - length of message payload | |
320 | * @gnlh: genetlink message header | |
321 | */ | |
322 | static inline int genlmsg_len(const struct genlmsghdr *gnlh) | |
323 | { | |
324 | struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - | |
325 | NLMSG_HDRLEN); | |
326 | return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); | |
327 | } | |
328 | ||
17db952c BS |
329 | /** |
330 | * genlmsg_msg_size - length of genetlink message not including padding | |
331 | * @payload: length of message payload | |
332 | */ | |
333 | static inline int genlmsg_msg_size(int payload) | |
334 | { | |
335 | return GENL_HDRLEN + payload; | |
336 | } | |
337 | ||
338 | /** | |
339 | * genlmsg_total_size - length of genetlink message including padding | |
340 | * @payload: length of message payload | |
341 | */ | |
342 | static inline int genlmsg_total_size(int payload) | |
343 | { | |
344 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
345 | } | |
346 | ||
3dabc715 TG |
347 | /** |
348 | * genlmsg_new - Allocate a new generic netlink message | |
349 | * @payload: size of the message payload | |
350 | * @flags: the type of memory to allocate. | |
351 | */ | |
352 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
353 | { | |
354 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
355 | } | |
356 | ||
62b68e99 JB |
357 | /** |
358 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 359 | * @family: the generic netlink family |
62b68e99 JB |
360 | * @net: the network namespace to report the error to |
361 | * @portid: the PORTID of a process that we want to skip (if any) | |
362 | * @group: the broadcast group that will notice the error | |
2a94fe48 | 363 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
364 | * @code: error code, must be negative (as usual in kernelspace) |
365 | * | |
366 | * This function returns the number of broadcast listeners that have set the | |
367 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
368 | */ | |
2ae0f17d JB |
369 | static inline int genl_set_err(const struct genl_family *family, |
370 | struct net *net, u32 portid, | |
371 | u32 group, int code) | |
62b68e99 | 372 | { |
91398a09 JB |
373 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
374 | return -EINVAL; | |
375 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
376 | return netlink_set_err(net->genl_sock, portid, group, code); |
377 | } | |
3dabc715 | 378 | |
2ae0f17d | 379 | static inline int genl_has_listeners(const struct genl_family *family, |
f8403a2e | 380 | struct net *net, unsigned int group) |
0d566379 ND |
381 | { |
382 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) | |
383 | return -EINVAL; | |
384 | group = family->mcgrp_offset + group; | |
f8403a2e | 385 | return netlink_has_listeners(net->genl_sock, group); |
0d566379 | 386 | } |
482a8524 | 387 | #endif /* __NET_GENERIC_NETLINK_H */ |