1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_GENERIC_NETLINK_H
3 #define __NET_GENERIC_NETLINK_H
4
5 #include <linux/net.h>
6 #include <linux/android_kabi.h>
7 #include <net/netlink.h>
8 #include <net/net_namespace.h>
9 #include <uapi/linux/genetlink.h>
10
11 #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
12
13 /* Non-parallel generic netlink requests are serialized by a global lock. */
14 void genl_lock(void);
15 void genl_unlock(void);
16
17 #define MODULE_ALIAS_GENL_FAMILY(family) \
18 MODULE_ALIAS_NET_PF_PROTO_NAME(PF_NETLINK, NETLINK_GENERIC, "-family-" family)
19
20 /* Binding to multicast group requires %CAP_NET_ADMIN */
21 #define GENL_MCAST_CAP_NET_ADMIN BIT(0)
22 /* Binding to multicast group requires %CAP_SYS_ADMIN */
23 #define GENL_MCAST_CAP_SYS_ADMIN BIT(1)
24
25 /**
26 * struct genl_multicast_group - generic netlink multicast group
27 * @name: name of the multicast group, names are per-family
28 * @flags: GENL_MCAST_* flags
29 */
30 struct genl_multicast_group {
31 char name[GENL_NAMSIZ];
32 u8 flags;
33 };
34
35 struct genl_split_ops;
36 struct genl_info;
37
38 /**
39 * struct genl_family - generic netlink family
40 * @hdrsize: length of user specific header in bytes
41 * @name: name of family
42 * @version: protocol version
43 * @maxattr: maximum number of attributes supported
44 * @policy: netlink policy
45 * @netnsok: set to true if the family can handle network
46 * namespaces and should be presented in all of them
47 * @parallel_ops: operations can be called in parallel and aren't
48 * synchronized by the core genetlink code
49 * @pre_doit: called before an operation's doit callback, it may
50 * do additional, common, filtering and return an error
51 * @post_doit: called after an operation's doit callback, it may
52 * undo operations done by pre_doit, for example release locks
53 * @bind: called when family multicast group is added to a netlink socket
54 * @unbind: called when family multicast group is removed from a netlink socket
55 * @module: pointer to the owning module (set to THIS_MODULE)
56 * @mcgrps: multicast groups used by this family
57 * @n_mcgrps: number of multicast groups
58 * @resv_start_op: first operation for which reserved fields of the header
59 * can be validated and policies are required (see below);
60 * new families should leave this field at zero
61 * @ops: the operations supported by this family
62 * @n_ops: number of operations supported by this family
63 * @small_ops: the small-struct operations supported by this family
64 * @n_small_ops: number of small-struct operations supported by this family
65 * @split_ops: the split do/dump form of operation definition
66 * @n_split_ops: number of entries in @split_ops, not that with split do/dump
67 * ops the number of entries is not the same as number of commands
68 * @sock_priv_size: the size of per-socket private memory
69 * @sock_priv_init: the per-socket private memory initializer
70 * @sock_priv_destroy: the per-socket private memory destructor
71 *
72 * Attribute policies (the combination of @policy and @maxattr fields)
73 * can be attached at the family level or at the operation level.
74 * If both are present the per-operation policy takes precedence.
75 * For operations before @resv_start_op lack of policy means that the core
76 * will perform no attribute parsing or validation. For newer operations
77 * if policy is not provided core will reject all TLV attributes.
78 */
79 struct genl_family {
80 unsigned int hdrsize;
81 char name[GENL_NAMSIZ];
82 unsigned int version;
83 unsigned int maxattr;
84 u8 netnsok:1;
85 u8 parallel_ops:1;
86 u8 n_ops;
87 u8 n_small_ops;
88 u8 n_split_ops;
89 u8 n_mcgrps;
90 u8 resv_start_op;
91 const struct nla_policy *policy;
92 int (*pre_doit)(const struct genl_split_ops *ops,
93 struct sk_buff *skb,
94 struct genl_info *info);
95 void (*post_doit)(const struct genl_split_ops *ops,
96 struct sk_buff *skb,
97 struct genl_info *info);
98 int (*bind)(int mcgrp);
99 void (*unbind)(int mcgrp);
100 const struct genl_ops * ops;
101 const struct genl_small_ops *small_ops;
102 const struct genl_split_ops *split_ops;
103 const struct genl_multicast_group *mcgrps;
104 struct module *module;
105
106 size_t sock_priv_size;
107 void (*sock_priv_init)(void *priv);
108 void (*sock_priv_destroy)(void *priv);
109
110 /* private: internal use only */
111 /* protocol family identifier */
112 int id;
113 /* starting number of multicast group IDs in this family */
114 unsigned int mcgrp_offset;
115 /* list of per-socket privs */
116 struct xarray *sock_privs;
117
118 ANDROID_KABI_RESERVE(1);
119 };
120
121 /**
122 * struct genl_info - receiving information
123 * @snd_seq: sending sequence number
124 * @snd_portid: netlink portid of sender
125 * @family: generic netlink family
126 * @nlhdr: netlink message header
127 * @genlhdr: generic netlink message header
128 * @attrs: netlink attributes
129 * @_net: network namespace
130 * @user_ptr: user pointers
131 * @extack: extended ACK report struct
132 */
133 struct genl_info {
134 u32 snd_seq;
135 u32 snd_portid;
136 const struct genl_family *family;
137 const struct nlmsghdr * nlhdr;
138 struct genlmsghdr * genlhdr;
139 struct nlattr ** attrs;
140 possible_net_t _net;
141 void * user_ptr[2];
142 struct netlink_ext_ack *extack;
143 };
144
genl_info_net(const struct genl_info * info)145 static inline struct net *genl_info_net(const struct genl_info *info)
146 {
147 return read_pnet(&info->_net);
148 }
149
genl_info_net_set(struct genl_info * info,struct net * net)150 static inline void genl_info_net_set(struct genl_info *info, struct net *net)
151 {
152 write_pnet(&info->_net, net);
153 }
154
genl_info_userhdr(const struct genl_info * info)155 static inline void *genl_info_userhdr(const struct genl_info *info)
156 {
157 return (u8 *)info->genlhdr + GENL_HDRLEN;
158 }
159
160 #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
161
162 #define GENL_SET_ERR_MSG_FMT(info, msg, args...) \
163 NL_SET_ERR_MSG_FMT((info)->extack, msg, ##args)
164
165 /* Report that a root attribute is missing */
166 #define GENL_REQ_ATTR_CHECK(info, attr) ({ \
167 const struct genl_info *__info = (info); \
168 \
169 NL_REQ_ATTR_CHECK(__info->extack, NULL, __info->attrs, (attr)); \
170 })
171
172 enum genl_validate_flags {
173 GENL_DONT_VALIDATE_STRICT = BIT(0),
174 GENL_DONT_VALIDATE_DUMP = BIT(1),
175 GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
176 };
177
178 /**
179 * struct genl_small_ops - generic netlink operations (small version)
180 * @cmd: command identifier
181 * @internal_flags: flags used by the family
182 * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM)
183 * @validate: validation flags from enum genl_validate_flags
184 * @doit: standard command callback
185 * @dumpit: callback for dumpers
186 *
187 * This is a cut-down version of struct genl_ops for users who don't need
188 * most of the ancillary infra and want to save space.
189 */
190 struct genl_small_ops {
191 int (*doit)(struct sk_buff *skb, struct genl_info *info);
192 int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb);
193 u8 cmd;
194 u8 internal_flags;
195 u8 flags;
196 u8 validate;
197 };
198
199 /**
200 * struct genl_ops - generic netlink operations
201 * @cmd: command identifier
202 * @internal_flags: flags used by the family
203 * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM)
204 * @maxattr: maximum number of attributes supported
205 * @policy: netlink policy (takes precedence over family policy)
206 * @validate: validation flags from enum genl_validate_flags
207 * @doit: standard command callback
208 * @start: start callback for dumps
209 * @dumpit: callback for dumpers
210 * @done: completion callback for dumps
211 */
212 struct genl_ops {
213 int (*doit)(struct sk_buff *skb,
214 struct genl_info *info);
215 int (*start)(struct netlink_callback *cb);
216 int (*dumpit)(struct sk_buff *skb,
217 struct netlink_callback *cb);
218 int (*done)(struct netlink_callback *cb);
219 const struct nla_policy *policy;
220 unsigned int maxattr;
221 u8 cmd;
222 u8 internal_flags;
223 u8 flags;
224 u8 validate;
225
226 ANDROID_KABI_RESERVE(1);
227 };
228
229 /**
230 * struct genl_split_ops - generic netlink operations (do/dump split version)
231 * @cmd: command identifier
232 * @internal_flags: flags used by the family
233 * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM)
234 * @validate: validation flags from enum genl_validate_flags
235 * @policy: netlink policy (takes precedence over family policy)
236 * @maxattr: maximum number of attributes supported
237 *
238 * Do callbacks:
239 * @pre_doit: called before an operation's @doit callback, it may
240 * do additional, common, filtering and return an error
241 * @doit: standard command callback
242 * @post_doit: called after an operation's @doit callback, it may
243 * undo operations done by pre_doit, for example release locks
244 *
245 * Dump callbacks:
246 * @start: start callback for dumps
247 * @dumpit: callback for dumpers
248 * @done: completion callback for dumps
249 *
250 * Do callbacks can be used if %GENL_CMD_CAP_DO is set in @flags.
251 * Dump callbacks can be used if %GENL_CMD_CAP_DUMP is set in @flags.
252 * Exactly one of those flags must be set.
253 */
254 struct genl_split_ops {
255 union {
256 struct {
257 int (*pre_doit)(const struct genl_split_ops *ops,
258 struct sk_buff *skb,
259 struct genl_info *info);
260 int (*doit)(struct sk_buff *skb,
261 struct genl_info *info);
262 void (*post_doit)(const struct genl_split_ops *ops,
263 struct sk_buff *skb,
264 struct genl_info *info);
265 };
266 struct {
267 int (*start)(struct netlink_callback *cb);
268 int (*dumpit)(struct sk_buff *skb,
269 struct netlink_callback *cb);
270 int (*done)(struct netlink_callback *cb);
271 };
272 };
273 const struct nla_policy *policy;
274 unsigned int maxattr;
275 u8 cmd;
276 u8 internal_flags;
277 u8 flags;
278 u8 validate;
279 };
280
281 /**
282 * struct genl_dumpit_info - info that is available during dumpit op call
283 * @op: generic netlink ops - for internal genl code usage
284 * @attrs: netlink attributes
285 * @info: struct genl_info describing the request
286 */
287 struct genl_dumpit_info {
288 struct genl_split_ops op;
289 struct genl_info info;
290 };
291
292 static inline const struct genl_dumpit_info *
genl_dumpit_info(struct netlink_callback * cb)293 genl_dumpit_info(struct netlink_callback *cb)
294 {
295 return cb->data;
296 }
297
298 static inline const struct genl_info *
genl_info_dump(struct netlink_callback * cb)299 genl_info_dump(struct netlink_callback *cb)
300 {
301 return &genl_dumpit_info(cb)->info;
302 }
303
304 /**
305 * genl_info_init_ntf() - initialize genl_info for notifications
306 * @info: genl_info struct to set up
307 * @family: pointer to the genetlink family
308 * @cmd: command to be used in the notification
309 *
310 * Initialize a locally declared struct genl_info to pass to various APIs.
311 * Intended to be used when creating notifications.
312 */
313 static inline void
genl_info_init_ntf(struct genl_info * info,const struct genl_family * family,u8 cmd)314 genl_info_init_ntf(struct genl_info *info, const struct genl_family *family,
315 u8 cmd)
316 {
317 struct genlmsghdr *hdr = (void *) &info->user_ptr[0];
318
319 memset(info, 0, sizeof(*info));
320 info->family = family;
321 info->genlhdr = hdr;
322 hdr->cmd = cmd;
323 }
324
genl_info_is_ntf(const struct genl_info * info)325 static inline bool genl_info_is_ntf(const struct genl_info *info)
326 {
327 return !info->nlhdr;
328 }
329
330 void *__genl_sk_priv_get(struct genl_family *family, struct sock *sk);
331 void *genl_sk_priv_get(struct genl_family *family, struct sock *sk);
332 int genl_register_family(struct genl_family *family);
333 int genl_unregister_family(const struct genl_family *family);
334 void genl_notify(const struct genl_family *family, struct sk_buff *skb,
335 struct genl_info *info, u32 group, gfp_t flags);
336
337 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
338 const struct genl_family *family, int flags, u8 cmd);
339
340 static inline void *
__genlmsg_iput(struct sk_buff * skb,const struct genl_info * info,int flags)341 __genlmsg_iput(struct sk_buff *skb, const struct genl_info *info, int flags)
342 {
343 return genlmsg_put(skb, info->snd_portid, info->snd_seq, info->family,
344 flags, info->genlhdr->cmd);
345 }
346
347 /**
348 * genlmsg_iput - start genetlink message based on genl_info
349 * @skb: skb in which message header will be placed
350 * @info: genl_info as provided to do/dump handlers
351 *
352 * Convenience wrapper which starts a genetlink message based on
353 * information in user request. @info should be either the struct passed
354 * by genetlink core to do/dump handlers (when constructing replies to
355 * such requests) or a struct initialized by genl_info_init_ntf()
356 * when constructing notifications.
357 *
358 * Returns pointer to new genetlink header.
359 */
360 static inline void *
genlmsg_iput(struct sk_buff * skb,const struct genl_info * info)361 genlmsg_iput(struct sk_buff *skb, const struct genl_info *info)
362 {
363 return __genlmsg_iput(skb, info, 0);
364 }
365
366 /**
367 * genlmsg_nlhdr - Obtain netlink header from user specified header
368 * @user_hdr: user header as returned from genlmsg_put()
369 *
370 * Returns pointer to netlink header.
371 */
genlmsg_nlhdr(void * user_hdr)372 static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
373 {
374 return (struct nlmsghdr *)((char *)user_hdr -
375 GENL_HDRLEN -
376 NLMSG_HDRLEN);
377 }
378
379 /**
380 * genlmsg_parse_deprecated - parse attributes of a genetlink message
381 * @nlh: netlink message header
382 * @family: genetlink message family
383 * @tb: destination array with maxtype+1 elements
384 * @maxtype: maximum attribute type to be expected
385 * @policy: validation policy
386 * @extack: extended ACK report struct
387 */
genlmsg_parse_deprecated(const struct nlmsghdr * nlh,const struct genl_family * family,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)388 static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
389 const struct genl_family *family,
390 struct nlattr *tb[], int maxtype,
391 const struct nla_policy *policy,
392 struct netlink_ext_ack *extack)
393 {
394 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
395 policy, NL_VALIDATE_LIBERAL, extack);
396 }
397
398 /**
399 * genlmsg_parse - parse attributes of a genetlink message
400 * @nlh: netlink message header
401 * @family: genetlink message family
402 * @tb: destination array with maxtype+1 elements
403 * @maxtype: maximum attribute type to be expected
404 * @policy: validation policy
405 * @extack: extended ACK report struct
406 */
genlmsg_parse(const struct nlmsghdr * nlh,const struct genl_family * family,struct nlattr * tb[],int maxtype,const struct nla_policy * policy,struct netlink_ext_ack * extack)407 static inline int genlmsg_parse(const struct nlmsghdr *nlh,
408 const struct genl_family *family,
409 struct nlattr *tb[], int maxtype,
410 const struct nla_policy *policy,
411 struct netlink_ext_ack *extack)
412 {
413 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
414 policy, NL_VALIDATE_STRICT, extack);
415 }
416
417 /**
418 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
419 * @cb: netlink callback structure that stores the sequence number
420 * @user_hdr: user header as returned from genlmsg_put()
421 *
422 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
423 * simpler to use with generic netlink.
424 */
genl_dump_check_consistent(struct netlink_callback * cb,void * user_hdr)425 static inline void genl_dump_check_consistent(struct netlink_callback *cb,
426 void *user_hdr)
427 {
428 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
429 }
430
431 /**
432 * genlmsg_put_reply - Add generic netlink header to a reply message
433 * @skb: socket buffer holding the message
434 * @info: receiver info
435 * @family: generic netlink family
436 * @flags: netlink message flags
437 * @cmd: generic netlink command
438 *
439 * Returns pointer to user specific header
440 */
genlmsg_put_reply(struct sk_buff * skb,struct genl_info * info,const struct genl_family * family,int flags,u8 cmd)441 static inline void *genlmsg_put_reply(struct sk_buff *skb,
442 struct genl_info *info,
443 const struct genl_family *family,
444 int flags, u8 cmd)
445 {
446 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
447 flags, cmd);
448 }
449
450 /**
451 * genlmsg_end - Finalize a generic netlink message
452 * @skb: socket buffer the message is stored in
453 * @hdr: user specific header
454 */
genlmsg_end(struct sk_buff * skb,void * hdr)455 static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
456 {
457 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
458 }
459
460 /**
461 * genlmsg_cancel - Cancel construction of a generic netlink message
462 * @skb: socket buffer the message is stored in
463 * @hdr: generic netlink message header
464 */
genlmsg_cancel(struct sk_buff * skb,void * hdr)465 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
466 {
467 if (hdr)
468 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
469 }
470
471 /**
472 * genlmsg_multicast_netns_filtered - multicast a netlink message
473 * to a specific netns with filter
474 * function
475 * @family: the generic netlink family
476 * @net: the net namespace
477 * @skb: netlink message as socket buffer
478 * @portid: own netlink portid to avoid sending to yourself
479 * @group: offset of multicast group in groups array
480 * @flags: allocation flags
481 * @filter: filter function
482 * @filter_data: filter function private data
483 *
484 * Return: 0 on success, negative error code for failure.
485 */
486 static inline int
genlmsg_multicast_netns_filtered(const struct genl_family * family,struct net * net,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags,netlink_filter_fn filter,void * filter_data)487 genlmsg_multicast_netns_filtered(const struct genl_family *family,
488 struct net *net, struct sk_buff *skb,
489 u32 portid, unsigned int group, gfp_t flags,
490 netlink_filter_fn filter,
491 void *filter_data)
492 {
493 if (WARN_ON_ONCE(group >= family->n_mcgrps))
494 return -EINVAL;
495 group = family->mcgrp_offset + group;
496 return nlmsg_multicast_filtered(net->genl_sock, skb, portid, group,
497 flags, filter, filter_data);
498 }
499
500 /**
501 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
502 * @family: the generic netlink family
503 * @net: the net namespace
504 * @skb: netlink message as socket buffer
505 * @portid: own netlink portid to avoid sending to yourself
506 * @group: offset of multicast group in groups array
507 * @flags: allocation flags
508 */
genlmsg_multicast_netns(const struct genl_family * family,struct net * net,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags)509 static inline int genlmsg_multicast_netns(const struct genl_family *family,
510 struct net *net, struct sk_buff *skb,
511 u32 portid, unsigned int group, gfp_t flags)
512 {
513 return genlmsg_multicast_netns_filtered(family, net, skb, portid,
514 group, flags, NULL, NULL);
515 }
516
517 /**
518 * genlmsg_multicast - multicast a netlink message to the default netns
519 * @family: the generic netlink family
520 * @skb: netlink message as socket buffer
521 * @portid: own netlink portid to avoid sending to yourself
522 * @group: offset of multicast group in groups array
523 * @flags: allocation flags
524 */
genlmsg_multicast(const struct genl_family * family,struct sk_buff * skb,u32 portid,unsigned int group,gfp_t flags)525 static inline int genlmsg_multicast(const struct genl_family *family,
526 struct sk_buff *skb, u32 portid,
527 unsigned int group, gfp_t flags)
528 {
529 return genlmsg_multicast_netns(family, &init_net, skb,
530 portid, group, flags);
531 }
532
533 /**
534 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
535 * @family: the generic netlink family
536 * @skb: netlink message as socket buffer
537 * @portid: own netlink portid to avoid sending to yourself
538 * @group: offset of multicast group in groups array
539 *
540 * This function must hold the RTNL or rcu_read_lock().
541 */
542 int genlmsg_multicast_allns(const struct genl_family *family,
543 struct sk_buff *skb, u32 portid,
544 unsigned int group);
545
546 /**
547 * genlmsg_unicast - unicast a netlink message
548 * @net: network namespace to look up @portid in
549 * @skb: netlink message as socket buffer
550 * @portid: netlink portid of the destination socket
551 */
genlmsg_unicast(struct net * net,struct sk_buff * skb,u32 portid)552 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
553 {
554 return nlmsg_unicast(net->genl_sock, skb, portid);
555 }
556
557 /**
558 * genlmsg_reply - reply to a request
559 * @skb: netlink message to be sent back
560 * @info: receiver information
561 */
genlmsg_reply(struct sk_buff * skb,struct genl_info * info)562 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
563 {
564 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
565 }
566
567 /**
568 * genlmsg_data - head of message payload
569 * @gnlh: genetlink message header
570 */
genlmsg_data(const struct genlmsghdr * gnlh)571 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
572 {
573 return ((unsigned char *) gnlh + GENL_HDRLEN);
574 }
575
576 /**
577 * genlmsg_len - length of message payload
578 * @gnlh: genetlink message header
579 */
genlmsg_len(const struct genlmsghdr * gnlh)580 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
581 {
582 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
583 NLMSG_HDRLEN);
584 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
585 }
586
587 /**
588 * genlmsg_msg_size - length of genetlink message not including padding
589 * @payload: length of message payload
590 */
genlmsg_msg_size(int payload)591 static inline int genlmsg_msg_size(int payload)
592 {
593 return GENL_HDRLEN + payload;
594 }
595
596 /**
597 * genlmsg_total_size - length of genetlink message including padding
598 * @payload: length of message payload
599 */
genlmsg_total_size(int payload)600 static inline int genlmsg_total_size(int payload)
601 {
602 return NLMSG_ALIGN(genlmsg_msg_size(payload));
603 }
604
605 /**
606 * genlmsg_new - Allocate a new generic netlink message
607 * @payload: size of the message payload
608 * @flags: the type of memory to allocate.
609 */
genlmsg_new(size_t payload,gfp_t flags)610 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
611 {
612 return nlmsg_new(genlmsg_total_size(payload), flags);
613 }
614
615 /**
616 * genl_set_err - report error to genetlink broadcast listeners
617 * @family: the generic netlink family
618 * @net: the network namespace to report the error to
619 * @portid: the PORTID of a process that we want to skip (if any)
620 * @group: the broadcast group that will notice the error
621 * (this is the offset of the multicast group in the groups array)
622 * @code: error code, must be negative (as usual in kernelspace)
623 *
624 * This function returns the number of broadcast listeners that have set the
625 * NETLINK_RECV_NO_ENOBUFS socket option.
626 */
genl_set_err(const struct genl_family * family,struct net * net,u32 portid,u32 group,int code)627 static inline int genl_set_err(const struct genl_family *family,
628 struct net *net, u32 portid,
629 u32 group, int code)
630 {
631 if (WARN_ON_ONCE(group >= family->n_mcgrps))
632 return -EINVAL;
633 group = family->mcgrp_offset + group;
634 return netlink_set_err(net->genl_sock, portid, group, code);
635 }
636
genl_has_listeners(const struct genl_family * family,struct net * net,unsigned int group)637 static inline int genl_has_listeners(const struct genl_family *family,
638 struct net *net, unsigned int group)
639 {
640 if (WARN_ON_ONCE(group >= family->n_mcgrps))
641 return -EINVAL;
642 group = family->mcgrp_offset + group;
643 return netlink_has_listeners(net->genl_sock, group);
644 }
645 #endif /* __NET_GENERIC_NETLINK_H */
646