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