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