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