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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 | |
a07ea4d9 | 23 | * @id: protocol family identifier (private) |
482a8524 TG |
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. | |
489111e5 | 42 | * @attrbuf: buffer to store parsed attributes (private) |
489111e5 JB |
43 | * @mcgrps: multicast groups used by this family |
44 | * @n_mcgrps: number of multicast groups | |
2a94fe48 | 45 | * @mcgrp_offset: starting number of multicast group IDs in this family |
489111e5 JB |
46 | * (private) |
47 | * @ops: the operations supported by this family | |
48 | * @n_ops: number of operations supported by this family | |
482a8524 | 49 | */ |
fd2c3ef7 | 50 | struct genl_family { |
98e4321b | 51 | int id; /* private */ |
482a8524 TG |
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 */ |
489111e5 JB |
67 | const struct genl_ops * ops; |
68 | const struct genl_multicast_group *mcgrps; | |
69 | unsigned int n_ops; | |
70 | unsigned int n_mcgrps; | |
2a94fe48 | 71 | unsigned int mcgrp_offset; /* private */ |
33c6b1f6 | 72 | struct module *module; |
482a8524 TG |
73 | }; |
74 | ||
2ae0f17d | 75 | struct nlattr **genl_family_attrbuf(const struct genl_family *family); |
c90c39da | 76 | |
482a8524 TG |
77 | /** |
78 | * struct genl_info - receiving information | |
79 | * @snd_seq: sending sequence number | |
15e47304 | 80 | * @snd_portid: netlink portid of sender |
482a8524 TG |
81 | * @nlhdr: netlink message header |
82 | * @genlhdr: generic netlink message header | |
83 | * @userhdr: user specific header | |
84 | * @attrs: netlink attributes | |
ff4c92d8 JB |
85 | * @_net: network namespace |
86 | * @user_ptr: user pointers | |
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]; |
482a8524 TG |
97 | }; |
98 | ||
134e6375 JB |
99 | static inline struct net *genl_info_net(struct genl_info *info) |
100 | { | |
c2d9ba9b | 101 | return read_pnet(&info->_net); |
134e6375 JB |
102 | } |
103 | ||
104 | static inline void genl_info_net_set(struct genl_info *info, struct net *net) | |
105 | { | |
c2d9ba9b | 106 | write_pnet(&info->_net, net); |
134e6375 | 107 | } |
134e6375 | 108 | |
482a8524 TG |
109 | /** |
110 | * struct genl_ops - generic netlink operations | |
111 | * @cmd: command identifier | |
ff4c92d8 | 112 | * @internal_flags: flags used by the family |
482a8524 TG |
113 | * @flags: flags |
114 | * @policy: attribute validation policy | |
115 | * @doit: standard command callback | |
fc9e50f5 | 116 | * @start: start callback for dumps |
482a8524 | 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); | |
fc9e50f5 | 125 | int (*start)(struct netlink_callback *cb); |
482a8524 TG |
126 | int (*dumpit)(struct sk_buff *skb, |
127 | struct netlink_callback *cb); | |
a4d1366d | 128 | int (*done)(struct netlink_callback *cb); |
3f5ccd06 JB |
129 | u8 cmd; |
130 | u8 internal_flags; | |
131 | u8 flags; | |
482a8524 TG |
132 | }; |
133 | ||
489111e5 | 134 | int genl_register_family(struct genl_family *family); |
2ae0f17d JB |
135 | int genl_unregister_family(const struct genl_family *family); |
136 | void genl_notify(const struct genl_family *family, struct sk_buff *skb, | |
92c14d9b | 137 | struct genl_info *info, u32 group, gfp_t flags); |
482a8524 | 138 | |
15e47304 | 139 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
2ae0f17d | 140 | const struct genl_family *family, int flags, u8 cmd); |
482a8524 | 141 | |
670dc283 JB |
142 | /** |
143 | * genlmsg_nlhdr - Obtain netlink header from user specified header | |
144 | * @user_hdr: user header as returned from genlmsg_put() | |
145 | * @family: generic netlink family | |
146 | * | |
147 | * Returns pointer to netlink header. | |
148 | */ | |
2ae0f17d JB |
149 | static inline struct nlmsghdr * |
150 | genlmsg_nlhdr(void *user_hdr, const struct genl_family *family) | |
670dc283 JB |
151 | { |
152 | return (struct nlmsghdr *)((char *)user_hdr - | |
153 | family->hdrsize - | |
154 | GENL_HDRLEN - | |
155 | NLMSG_HDRLEN); | |
156 | } | |
157 | ||
7b1883ce JS |
158 | /** |
159 | * genlmsg_parse - parse attributes of a genetlink message | |
160 | * @nlh: netlink message header | |
161 | * @family: genetlink message family | |
162 | * @tb: destination array with maxtype+1 elements | |
163 | * @maxtype: maximum attribute type to be expected | |
164 | * @policy: validation policy | |
165 | * */ | |
166 | static inline int genlmsg_parse(const struct nlmsghdr *nlh, | |
167 | const struct genl_family *family, | |
168 | struct nlattr *tb[], int maxtype, | |
169 | const struct nla_policy *policy) | |
170 | { | |
171 | return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype, | |
172 | policy); | |
173 | } | |
174 | ||
670dc283 JB |
175 | /** |
176 | * genl_dump_check_consistent - check if sequence is consistent and advertise if not | |
177 | * @cb: netlink callback structure that stores the sequence number | |
178 | * @user_hdr: user header as returned from genlmsg_put() | |
179 | * @family: generic netlink family | |
180 | * | |
181 | * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it | |
182 | * simpler to use with generic netlink. | |
183 | */ | |
184 | static inline void genl_dump_check_consistent(struct netlink_callback *cb, | |
185 | void *user_hdr, | |
2ae0f17d | 186 | const struct genl_family *family) |
670dc283 JB |
187 | { |
188 | nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family)); | |
189 | } | |
190 | ||
17c157c8 TG |
191 | /** |
192 | * genlmsg_put_reply - Add generic netlink header to a reply message | |
193 | * @skb: socket buffer holding the message | |
194 | * @info: receiver info | |
195 | * @family: generic netlink family | |
196 | * @flags: netlink message flags | |
197 | * @cmd: generic netlink command | |
198 | * | |
199 | * Returns pointer to user specific header | |
200 | */ | |
201 | static inline void *genlmsg_put_reply(struct sk_buff *skb, | |
202 | struct genl_info *info, | |
2ae0f17d | 203 | const struct genl_family *family, |
17c157c8 TG |
204 | int flags, u8 cmd) |
205 | { | |
15e47304 | 206 | return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, |
17c157c8 TG |
207 | flags, cmd); |
208 | } | |
209 | ||
482a8524 TG |
210 | /** |
211 | * genlmsg_end - Finalize a generic netlink message | |
212 | * @skb: socket buffer the message is stored in | |
213 | * @hdr: user specific header | |
214 | */ | |
053c095a | 215 | static inline void genlmsg_end(struct sk_buff *skb, void *hdr) |
482a8524 | 216 | { |
053c095a | 217 | nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); |
482a8524 TG |
218 | } |
219 | ||
220 | /** | |
221 | * genlmsg_cancel - Cancel construction of a generic netlink message | |
222 | * @skb: socket buffer the message is stored in | |
223 | * @hdr: generic netlink message header | |
224 | */ | |
bc3ed28c | 225 | static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) |
482a8524 | 226 | { |
38db9e1d JL |
227 | if (hdr) |
228 | nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | |
482a8524 TG |
229 | } |
230 | ||
231 | /** | |
134e6375 | 232 | * genlmsg_multicast_netns - multicast a netlink message to a specific netns |
68eb5503 | 233 | * @family: the generic netlink family |
134e6375 JB |
234 | * @net: the net namespace |
235 | * @skb: netlink message as socket buffer | |
15e47304 | 236 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 237 | * @group: offset of multicast group in groups array |
134e6375 JB |
238 | * @flags: allocation flags |
239 | */ | |
2ae0f17d | 240 | static inline int genlmsg_multicast_netns(const struct genl_family *family, |
68eb5503 | 241 | struct net *net, struct sk_buff *skb, |
15e47304 | 242 | u32 portid, unsigned int group, gfp_t flags) |
134e6375 | 243 | { |
220815a9 | 244 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
2a94fe48 JB |
245 | return -EINVAL; |
246 | group = family->mcgrp_offset + group; | |
15e47304 | 247 | return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); |
134e6375 JB |
248 | } |
249 | ||
250 | /** | |
251 | * genlmsg_multicast - multicast a netlink message to the default netns | |
68eb5503 | 252 | * @family: the generic netlink family |
482a8524 | 253 | * @skb: netlink message as socket buffer |
15e47304 | 254 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 255 | * @group: offset of multicast group in groups array |
d387f6ad | 256 | * @flags: allocation flags |
482a8524 | 257 | */ |
2ae0f17d | 258 | static inline int genlmsg_multicast(const struct genl_family *family, |
68eb5503 | 259 | struct sk_buff *skb, u32 portid, |
d387f6ad | 260 | unsigned int group, gfp_t flags) |
482a8524 | 261 | { |
68eb5503 JB |
262 | return genlmsg_multicast_netns(family, &init_net, skb, |
263 | portid, group, flags); | |
482a8524 TG |
264 | } |
265 | ||
134e6375 JB |
266 | /** |
267 | * genlmsg_multicast_allns - multicast a netlink message to all net namespaces | |
68eb5503 | 268 | * @family: the generic netlink family |
134e6375 | 269 | * @skb: netlink message as socket buffer |
15e47304 | 270 | * @portid: own netlink portid to avoid sending to yourself |
2a94fe48 | 271 | * @group: offset of multicast group in groups array |
134e6375 JB |
272 | * @flags: allocation flags |
273 | * | |
274 | * This function must hold the RTNL or rcu_read_lock(). | |
275 | */ | |
2ae0f17d | 276 | int genlmsg_multicast_allns(const struct genl_family *family, |
68eb5503 | 277 | struct sk_buff *skb, u32 portid, |
134e6375 JB |
278 | unsigned int group, gfp_t flags); |
279 | ||
482a8524 TG |
280 | /** |
281 | * genlmsg_unicast - unicast a netlink message | |
282 | * @skb: netlink message as socket buffer | |
15e47304 | 283 | * @portid: netlink portid of the destination socket |
482a8524 | 284 | */ |
15e47304 | 285 | static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) |
482a8524 | 286 | { |
15e47304 | 287 | return nlmsg_unicast(net->genl_sock, skb, portid); |
482a8524 TG |
288 | } |
289 | ||
81878d27 TG |
290 | /** |
291 | * genlmsg_reply - reply to a request | |
292 | * @skb: netlink message to be sent back | |
293 | * @info: receiver information | |
294 | */ | |
295 | static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) | |
296 | { | |
15e47304 | 297 | return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); |
81878d27 TG |
298 | } |
299 | ||
fb0ba6bd BS |
300 | /** |
301 | * gennlmsg_data - head of message payload | |
70f23fd6 | 302 | * @gnlh: genetlink message header |
fb0ba6bd BS |
303 | */ |
304 | static inline void *genlmsg_data(const struct genlmsghdr *gnlh) | |
305 | { | |
306 | return ((unsigned char *) gnlh + GENL_HDRLEN); | |
307 | } | |
308 | ||
309 | /** | |
310 | * genlmsg_len - length of message payload | |
311 | * @gnlh: genetlink message header | |
312 | */ | |
313 | static inline int genlmsg_len(const struct genlmsghdr *gnlh) | |
314 | { | |
315 | struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - | |
316 | NLMSG_HDRLEN); | |
317 | return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); | |
318 | } | |
319 | ||
17db952c BS |
320 | /** |
321 | * genlmsg_msg_size - length of genetlink message not including padding | |
322 | * @payload: length of message payload | |
323 | */ | |
324 | static inline int genlmsg_msg_size(int payload) | |
325 | { | |
326 | return GENL_HDRLEN + payload; | |
327 | } | |
328 | ||
329 | /** | |
330 | * genlmsg_total_size - length of genetlink message including padding | |
331 | * @payload: length of message payload | |
332 | */ | |
333 | static inline int genlmsg_total_size(int payload) | |
334 | { | |
335 | return NLMSG_ALIGN(genlmsg_msg_size(payload)); | |
336 | } | |
337 | ||
3dabc715 TG |
338 | /** |
339 | * genlmsg_new - Allocate a new generic netlink message | |
340 | * @payload: size of the message payload | |
341 | * @flags: the type of memory to allocate. | |
342 | */ | |
343 | static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) | |
344 | { | |
345 | return nlmsg_new(genlmsg_total_size(payload), flags); | |
346 | } | |
347 | ||
62b68e99 JB |
348 | /** |
349 | * genl_set_err - report error to genetlink broadcast listeners | |
68eb5503 | 350 | * @family: the generic netlink family |
62b68e99 JB |
351 | * @net: the network namespace to report the error to |
352 | * @portid: the PORTID of a process that we want to skip (if any) | |
353 | * @group: the broadcast group that will notice the error | |
2a94fe48 | 354 | * (this is the offset of the multicast group in the groups array) |
62b68e99 JB |
355 | * @code: error code, must be negative (as usual in kernelspace) |
356 | * | |
357 | * This function returns the number of broadcast listeners that have set the | |
358 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
359 | */ | |
2ae0f17d JB |
360 | static inline int genl_set_err(const struct genl_family *family, |
361 | struct net *net, u32 portid, | |
362 | u32 group, int code) | |
62b68e99 | 363 | { |
91398a09 JB |
364 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) |
365 | return -EINVAL; | |
366 | group = family->mcgrp_offset + group; | |
62b68e99 JB |
367 | return netlink_set_err(net->genl_sock, portid, group, code); |
368 | } | |
3dabc715 | 369 | |
2ae0f17d | 370 | static inline int genl_has_listeners(const struct genl_family *family, |
f8403a2e | 371 | struct net *net, unsigned int group) |
0d566379 ND |
372 | { |
373 | if (WARN_ON_ONCE(group >= family->n_mcgrps)) | |
374 | return -EINVAL; | |
375 | group = family->mcgrp_offset + group; | |
f8403a2e | 376 | return netlink_has_listeners(net->genl_sock, group); |
0d566379 | 377 | } |
482a8524 | 378 | #endif /* __NET_GENERIC_NETLINK_H */ |