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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 */
15struct genl_multicast_group {
16 char name[GENL_NAMSIZ];
17 u8 flags;
18};
19
20struct genl_ops;
21struct genl_info;
22
23/**
24 * struct genl_family - generic netlink family
25 * @id: protocol family identifier (private)
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 * @mcgrps: multicast groups used by this family
40 * @n_mcgrps: number of multicast groups
41 * @mcgrp_offset: starting number of multicast group IDs in this family
42 * (private)
43 * @ops: the operations supported by this family
44 * @n_ops: number of operations supported by this family
45 * @small_ops: the small-struct operations supported by this family
46 * @n_small_ops: number of small-struct operations supported by this family
47 */
48struct genl_family {
49 int id; /* private */
50 unsigned int hdrsize;
51 char name[GENL_NAMSIZ];
52 unsigned int version;
53 unsigned int maxattr;
54 unsigned int mcgrp_offset; /* private */
55 u8 netnsok:1;
56 u8 parallel_ops:1;
57 u8 n_ops;
58 u8 n_small_ops;
59 u8 n_mcgrps;
60 const struct nla_policy *policy;
61 int (*pre_doit)(const struct genl_ops *ops,
62 struct sk_buff *skb,
63 struct genl_info *info);
64 void (*post_doit)(const struct genl_ops *ops,
65 struct sk_buff *skb,
66 struct genl_info *info);
67 const struct genl_ops * ops;
68 const struct genl_small_ops *small_ops;
69 const struct genl_multicast_group *mcgrps;
70 struct module *module;
71};
72
73/**
74 * struct genl_info - receiving information
75 * @snd_seq: sending sequence number
76 * @snd_portid: netlink portid of sender
77 * @nlhdr: netlink message header
78 * @genlhdr: generic netlink message header
79 * @userhdr: user specific header
80 * @attrs: netlink attributes
81 * @_net: network namespace
82 * @user_ptr: user pointers
83 * @extack: extended ACK report struct
84 */
85struct genl_info {
86 u32 snd_seq;
87 u32 snd_portid;
88 struct nlmsghdr * nlhdr;
89 struct genlmsghdr * genlhdr;
90 void * userhdr;
91 struct nlattr ** attrs;
92 possible_net_t _net;
93 void * user_ptr[2];
94 struct netlink_ext_ack *extack;
95};
96
97static inline struct net *genl_info_net(struct genl_info *info)
98{
99 return read_pnet(&info->_net);
100}
101
102static inline void genl_info_net_set(struct genl_info *info, struct net *net)
103{
104 write_pnet(&info->_net, net);
105}
106
107#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
108
109enum genl_validate_flags {
110 GENL_DONT_VALIDATE_STRICT = BIT(0),
111 GENL_DONT_VALIDATE_DUMP = BIT(1),
112 GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
113};
114
115/**
116 * struct genl_small_ops - generic netlink operations (small version)
117 * @cmd: command identifier
118 * @internal_flags: flags used by the family
119 * @flags: flags
120 * @validate: validation flags from enum genl_validate_flags
121 * @doit: standard command callback
122 * @dumpit: callback for dumpers
123 *
124 * This is a cut-down version of struct genl_ops for users who don't need
125 * most of the ancillary infra and want to save space.
126 */
127struct genl_small_ops {
128 int (*doit)(struct sk_buff *skb, struct genl_info *info);
129 int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb);
130 u8 cmd;
131 u8 internal_flags;
132 u8 flags;
133 u8 validate;
134};
135
136/**
137 * struct genl_ops - generic netlink operations
138 * @cmd: command identifier
139 * @internal_flags: flags used by the family
140 * @flags: flags
141 * @maxattr: maximum number of attributes supported
142 * @policy: netlink policy (takes precedence over family policy)
143 * @validate: validation flags from enum genl_validate_flags
144 * @doit: standard command callback
145 * @start: start callback for dumps
146 * @dumpit: callback for dumpers
147 * @done: completion callback for dumps
148 */
149struct genl_ops {
150 int (*doit)(struct sk_buff *skb,
151 struct genl_info *info);
152 int (*start)(struct netlink_callback *cb);
153 int (*dumpit)(struct sk_buff *skb,
154 struct netlink_callback *cb);
155 int (*done)(struct netlink_callback *cb);
156 const struct nla_policy *policy;
157 unsigned int maxattr;
158 u8 cmd;
159 u8 internal_flags;
160 u8 flags;
161 u8 validate;
162};
163
164/**
165 * struct genl_info - info that is available during dumpit op call
166 * @family: generic netlink family - for internal genl code usage
167 * @ops: generic netlink ops - for internal genl code usage
168 * @attrs: netlink attributes
169 */
170struct genl_dumpit_info {
171 const struct genl_family *family;
172 struct genl_ops op;
173 struct nlattr **attrs;
174};
175
176static inline const struct genl_dumpit_info *
177genl_dumpit_info(struct netlink_callback *cb)
178{
179 return cb->data;
180}
181
182int genl_register_family(struct genl_family *family);
183int genl_unregister_family(const struct genl_family *family);
184void genl_notify(const struct genl_family *family, struct sk_buff *skb,
185 struct genl_info *info, u32 group, gfp_t flags);
186
187void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
188 const struct genl_family *family, int flags, u8 cmd);
189
190/**
191 * genlmsg_nlhdr - Obtain netlink header from user specified header
192 * @user_hdr: user header as returned from genlmsg_put()
193 *
194 * Returns pointer to netlink header.
195 */
196static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
197{
198 return (struct nlmsghdr *)((char *)user_hdr -
199 GENL_HDRLEN -
200 NLMSG_HDRLEN);
201}
202
203/**
204 * genlmsg_parse_deprecated - parse attributes of a genetlink message
205 * @nlh: netlink message header
206 * @family: genetlink message family
207 * @tb: destination array with maxtype+1 elements
208 * @maxtype: maximum attribute type to be expected
209 * @policy: validation policy
210 * @extack: extended ACK report struct
211 */
212static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
213 const struct genl_family *family,
214 struct nlattr *tb[], int maxtype,
215 const struct nla_policy *policy,
216 struct netlink_ext_ack *extack)
217{
218 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
219 policy, NL_VALIDATE_LIBERAL, extack);
220}
221
222/**
223 * genlmsg_parse - parse attributes of a genetlink message
224 * @nlh: netlink message header
225 * @family: genetlink message family
226 * @tb: destination array with maxtype+1 elements
227 * @maxtype: maximum attribute type to be expected
228 * @policy: validation policy
229 * @extack: extended ACK report struct
230 */
231static inline int genlmsg_parse(const struct nlmsghdr *nlh,
232 const struct genl_family *family,
233 struct nlattr *tb[], int maxtype,
234 const struct nla_policy *policy,
235 struct netlink_ext_ack *extack)
236{
237 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
238 policy, NL_VALIDATE_STRICT, extack);
239}
240
241/**
242 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
243 * @cb: netlink callback structure that stores the sequence number
244 * @user_hdr: user header as returned from genlmsg_put()
245 *
246 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
247 * simpler to use with generic netlink.
248 */
249static inline void genl_dump_check_consistent(struct netlink_callback *cb,
250 void *user_hdr)
251{
252 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
253}
254
255/**
256 * genlmsg_put_reply - Add generic netlink header to a reply message
257 * @skb: socket buffer holding the message
258 * @info: receiver info
259 * @family: generic netlink family
260 * @flags: netlink message flags
261 * @cmd: generic netlink command
262 *
263 * Returns pointer to user specific header
264 */
265static inline void *genlmsg_put_reply(struct sk_buff *skb,
266 struct genl_info *info,
267 const struct genl_family *family,
268 int flags, u8 cmd)
269{
270 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
271 flags, cmd);
272}
273
274/**
275 * genlmsg_end - Finalize a generic netlink message
276 * @skb: socket buffer the message is stored in
277 * @hdr: user specific header
278 */
279static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
280{
281 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
282}
283
284/**
285 * genlmsg_cancel - Cancel construction of a generic netlink message
286 * @skb: socket buffer the message is stored in
287 * @hdr: generic netlink message header
288 */
289static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
290{
291 if (hdr)
292 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
293}
294
295/**
296 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
297 * @family: the generic netlink family
298 * @net: the net namespace
299 * @skb: netlink message as socket buffer
300 * @portid: own netlink portid to avoid sending to yourself
301 * @group: offset of multicast group in groups array
302 * @flags: allocation flags
303 */
304static inline int genlmsg_multicast_netns(const struct genl_family *family,
305 struct net *net, struct sk_buff *skb,
306 u32 portid, unsigned int group, gfp_t flags)
307{
308 if (WARN_ON_ONCE(group >= family->n_mcgrps))
309 return -EINVAL;
310 group = family->mcgrp_offset + group;
311 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
312}
313
314/**
315 * genlmsg_multicast - multicast a netlink message to the default netns
316 * @family: the generic netlink family
317 * @skb: netlink message as socket buffer
318 * @portid: own netlink portid to avoid sending to yourself
319 * @group: offset of multicast group in groups array
320 * @flags: allocation flags
321 */
322static inline int genlmsg_multicast(const struct genl_family *family,
323 struct sk_buff *skb, u32 portid,
324 unsigned int group, gfp_t flags)
325{
326 return genlmsg_multicast_netns(family, &init_net, skb,
327 portid, group, flags);
328}
329
330/**
331 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
332 * @family: the generic netlink family
333 * @skb: netlink message as socket buffer
334 * @portid: own netlink portid to avoid sending to yourself
335 * @group: offset of multicast group in groups array
336 * @flags: allocation flags
337 *
338 * This function must hold the RTNL or rcu_read_lock().
339 */
340int genlmsg_multicast_allns(const struct genl_family *family,
341 struct sk_buff *skb, u32 portid,
342 unsigned int group, gfp_t flags);
343
344/**
345 * genlmsg_unicast - unicast a netlink message
346 * @skb: netlink message as socket buffer
347 * @portid: netlink portid of the destination socket
348 */
349static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
350{
351 return nlmsg_unicast(net->genl_sock, skb, portid);
352}
353
354/**
355 * genlmsg_reply - reply to a request
356 * @skb: netlink message to be sent back
357 * @info: receiver information
358 */
359static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
360{
361 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
362}
363
364/**
365 * gennlmsg_data - head of message payload
366 * @gnlh: genetlink message header
367 */
368static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
369{
370 return ((unsigned char *) gnlh + GENL_HDRLEN);
371}
372
373/**
374 * genlmsg_len - length of message payload
375 * @gnlh: genetlink message header
376 */
377static inline int genlmsg_len(const struct genlmsghdr *gnlh)
378{
379 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
380 NLMSG_HDRLEN);
381 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
382}
383
384/**
385 * genlmsg_msg_size - length of genetlink message not including padding
386 * @payload: length of message payload
387 */
388static inline int genlmsg_msg_size(int payload)
389{
390 return GENL_HDRLEN + payload;
391}
392
393/**
394 * genlmsg_total_size - length of genetlink message including padding
395 * @payload: length of message payload
396 */
397static inline int genlmsg_total_size(int payload)
398{
399 return NLMSG_ALIGN(genlmsg_msg_size(payload));
400}
401
402/**
403 * genlmsg_new - Allocate a new generic netlink message
404 * @payload: size of the message payload
405 * @flags: the type of memory to allocate.
406 */
407static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
408{
409 return nlmsg_new(genlmsg_total_size(payload), flags);
410}
411
412/**
413 * genl_set_err - report error to genetlink broadcast listeners
414 * @family: the generic netlink family
415 * @net: the network namespace to report the error to
416 * @portid: the PORTID of a process that we want to skip (if any)
417 * @group: the broadcast group that will notice the error
418 * (this is the offset of the multicast group in the groups array)
419 * @code: error code, must be negative (as usual in kernelspace)
420 *
421 * This function returns the number of broadcast listeners that have set the
422 * NETLINK_RECV_NO_ENOBUFS socket option.
423 */
424static inline int genl_set_err(const struct genl_family *family,
425 struct net *net, u32 portid,
426 u32 group, int code)
427{
428 if (WARN_ON_ONCE(group >= family->n_mcgrps))
429 return -EINVAL;
430 group = family->mcgrp_offset + group;
431 return netlink_set_err(net->genl_sock, portid, group, code);
432}
433
434static inline int genl_has_listeners(const struct genl_family *family,
435 struct net *net, unsigned int group)
436{
437 if (WARN_ON_ONCE(group >= family->n_mcgrps))
438 return -EINVAL;
439 group = family->mcgrp_offset + group;
440 return netlink_has_listeners(net->genl_sock, group);
441}
442#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 */