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