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v3.1
 
  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/**
  9 * struct genl_multicast_group - generic netlink multicast group
 10 * @name: name of the multicast group, names are per-family
 11 * @id: multicast group ID, assigned by the core, to use with
 12 *      genlmsg_multicast().
 13 * @list: list entry for linking
 14 * @family: pointer to family, need not be set before registering
 15 */
 16struct genl_multicast_group {
 17	struct genl_family	*family;	/* private */
 18	struct list_head	list;		/* private */
 19	char			name[GENL_NAMSIZ];
 20	u32			id;
 21};
 22
 23struct genl_ops;
 24struct genl_info;
 25
 26/**
 27 * struct genl_family - generic netlink family
 28 * @id: protocol family idenfitier
 29 * @hdrsize: length of user specific header in bytes
 30 * @name: name of family
 31 * @version: protocol version
 32 * @maxattr: maximum number of attributes supported
 
 33 * @netnsok: set to true if the family can handle network
 34 *	namespaces and should be presented in all of them
 
 
 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 * @attrbuf: buffer to store parsed attributes
 40 * @ops_list: list of all assigned operations
 41 * @family_list: family list
 42 * @mcast_groups: multicast groups list
 
 
 43 */
 44struct genl_family {
 45	unsigned int		id;
 46	unsigned int		hdrsize;
 47	char			name[GENL_NAMSIZ];
 48	unsigned int		version;
 49	unsigned int		maxattr;
 50	bool			netnsok;
 51	int			(*pre_doit)(struct genl_ops *ops,
 
 
 52					    struct sk_buff *skb,
 53					    struct genl_info *info);
 54	void			(*post_doit)(struct genl_ops *ops,
 55					     struct sk_buff *skb,
 56					     struct genl_info *info);
 57	struct nlattr **	attrbuf;	/* private */
 58	struct list_head	ops_list;	/* private */
 59	struct list_head	family_list;	/* private */
 60	struct list_head	mcast_groups;	/* private */
 
 
 61};
 62
 63/**
 64 * struct genl_info - receiving information
 65 * @snd_seq: sending sequence number
 66 * @snd_pid: netlink pid of sender
 67 * @nlhdr: netlink message header
 68 * @genlhdr: generic netlink message header
 69 * @userhdr: user specific header
 70 * @attrs: netlink attributes
 71 * @_net: network namespace
 72 * @user_ptr: user pointers
 
 73 */
 74struct genl_info {
 75	u32			snd_seq;
 76	u32			snd_pid;
 77	struct nlmsghdr *	nlhdr;
 78	struct genlmsghdr *	genlhdr;
 79	void *			userhdr;
 80	struct nlattr **	attrs;
 81#ifdef CONFIG_NET_NS
 82	struct net *		_net;
 83#endif
 84	void *			user_ptr[2];
 
 85};
 86
 87static inline struct net *genl_info_net(struct genl_info *info)
 88{
 89	return read_pnet(&info->_net);
 90}
 91
 92static inline void genl_info_net_set(struct genl_info *info, struct net *net)
 93{
 94	write_pnet(&info->_net, net);
 95}
 96
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 97/**
 98 * struct genl_ops - generic netlink operations
 99 * @cmd: command identifier
100 * @internal_flags: flags used by the family
101 * @flags: flags
102 * @policy: attribute validation policy
103 * @doit: standard command callback
 
104 * @dumpit: callback for dumpers
105 * @done: completion callback for dumps
106 * @ops_list: operations list
107 */
108struct genl_ops {
109	u8			cmd;
110	u8			internal_flags;
111	unsigned int		flags;
112	const struct nla_policy	*policy;
113	int		       (*doit)(struct sk_buff *skb,
114				       struct genl_info *info);
 
115	int		       (*dumpit)(struct sk_buff *skb,
116					 struct netlink_callback *cb);
117	int		       (*done)(struct netlink_callback *cb);
118	struct list_head	ops_list;
 
 
 
119};
120
121extern int genl_register_family(struct genl_family *family);
122extern int genl_register_family_with_ops(struct genl_family *family,
123	struct genl_ops *ops, size_t n_ops);
124extern int genl_unregister_family(struct genl_family *family);
125extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
126extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
127extern int genl_register_mc_group(struct genl_family *family,
128				  struct genl_multicast_group *grp);
129extern void genl_unregister_mc_group(struct genl_family *family,
130				     struct genl_multicast_group *grp);
131
132/**
133 * genlmsg_put - Add generic netlink header to netlink message
134 * @skb: socket buffer holding the message
135 * @pid: netlink pid the message is addressed to
136 * @seq: sequence number (usually the one of the sender)
137 * @family: generic netlink family
138 * @flags netlink message flags
139 * @cmd: generic netlink command
140 *
141 * Returns pointer to user specific header
142 */
143static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
144				struct genl_family *family, int flags, u8 cmd)
145{
146	struct nlmsghdr *nlh;
147	struct genlmsghdr *hdr;
148
149	nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
150			family->hdrsize, flags);
151	if (nlh == NULL)
152		return NULL;
153
154	hdr = nlmsg_data(nlh);
155	hdr->cmd = cmd;
156	hdr->version = family->version;
157	hdr->reserved = 0;
158
159	return (char *) hdr + GENL_HDRLEN;
160}
161
162/**
163 * genlmsg_nlhdr - Obtain netlink header from user specified header
164 * @user_hdr: user header as returned from genlmsg_put()
165 * @family: generic netlink family
166 *
167 * Returns pointer to netlink header.
168 */
169static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
170					     struct genl_family *family)
171{
172	return (struct nlmsghdr *)((char *)user_hdr -
173				   family->hdrsize -
174				   GENL_HDRLEN -
175				   NLMSG_HDRLEN);
176}
177
178/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
179 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
180 * @cb: netlink callback structure that stores the sequence number
181 * @user_hdr: user header as returned from genlmsg_put()
182 * @family: generic netlink family
183 *
184 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
185 * simpler to use with generic netlink.
186 */
187static inline void genl_dump_check_consistent(struct netlink_callback *cb,
188					      void *user_hdr,
189					      struct genl_family *family)
190{
191	nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
192}
193
194/**
195 * genlmsg_put_reply - Add generic netlink header to a reply message
196 * @skb: socket buffer holding the message
197 * @info: receiver info
198 * @family: generic netlink family
199 * @flags: netlink message flags
200 * @cmd: generic netlink command
201 *
202 * Returns pointer to user specific header
203 */
204static inline void *genlmsg_put_reply(struct sk_buff *skb,
205				      struct genl_info *info,
206				      struct genl_family *family,
207				      int flags, u8 cmd)
208{
209	return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
210			   flags, cmd);
211}
212
213/**
214 * genlmsg_end - Finalize a generic netlink message
215 * @skb: socket buffer the message is stored in
216 * @hdr: user specific header
217 */
218static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
219{
220	return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
221}
222
223/**
224 * genlmsg_cancel - Cancel construction of a generic netlink message
225 * @skb: socket buffer the message is stored in
226 * @hdr: generic netlink message header
227 */
228static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
229{
230	if (hdr)
231		nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
232}
233
234/**
235 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
 
236 * @net: the net namespace
237 * @skb: netlink message as socket buffer
238 * @pid: own netlink pid to avoid sending to yourself
239 * @group: multicast group id
240 * @flags: allocation flags
241 */
242static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
243					  u32 pid, unsigned int group, gfp_t flags)
244{
245	return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
 
 
 
 
246}
247
248/**
249 * genlmsg_multicast - multicast a netlink message to the default netns
 
250 * @skb: netlink message as socket buffer
251 * @pid: own netlink pid to avoid sending to yourself
252 * @group: multicast group id
253 * @flags: allocation flags
254 */
255static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
 
256				    unsigned int group, gfp_t flags)
257{
258	return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
 
259}
260
261/**
262 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
 
263 * @skb: netlink message as socket buffer
264 * @pid: own netlink pid to avoid sending to yourself
265 * @group: multicast group id
266 * @flags: allocation flags
267 *
268 * This function must hold the RTNL or rcu_read_lock().
269 */
270int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
 
271			    unsigned int group, gfp_t flags);
272
273/**
274 * genlmsg_unicast - unicast a netlink message
275 * @skb: netlink message as socket buffer
276 * @pid: netlink pid of the destination socket
277 */
278static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
279{
280	return nlmsg_unicast(net->genl_sock, skb, pid);
281}
282
283/**
284 * genlmsg_reply - reply to a request
285 * @skb: netlink message to be sent back
286 * @info: receiver information
287 */
288static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
289{
290	return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
291}
292
293/**
294 * gennlmsg_data - head of message payload
295 * @gnlh: genetlink message header
296 */
297static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
298{
299	return ((unsigned char *) gnlh + GENL_HDRLEN);
300}
301
302/**
303 * genlmsg_len - length of message payload
304 * @gnlh: genetlink message header
305 */
306static inline int genlmsg_len(const struct genlmsghdr *gnlh)
307{
308	struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
309							NLMSG_HDRLEN);
310	return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
311}
312
313/**
314 * genlmsg_msg_size - length of genetlink message not including padding
315 * @payload: length of message payload
316 */
317static inline int genlmsg_msg_size(int payload)
318{
319	return GENL_HDRLEN + payload;
320}
321
322/**
323 * genlmsg_total_size - length of genetlink message including padding
324 * @payload: length of message payload
325 */
326static inline int genlmsg_total_size(int payload)
327{
328	return NLMSG_ALIGN(genlmsg_msg_size(payload));
329}
330
331/**
332 * genlmsg_new - Allocate a new generic netlink message
333 * @payload: size of the message payload
334 * @flags: the type of memory to allocate.
335 */
336static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
337{
338	return nlmsg_new(genlmsg_total_size(payload), flags);
339}
340
341
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
342#endif	/* __NET_GENERIC_NETLINK_H */
v5.9
  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 * @mcgrps: multicast groups used by this family
 39 * @n_mcgrps: number of multicast groups
 40 * @mcgrp_offset: starting number of multicast group IDs in this family
 41 *	(private)
 42 * @ops: the operations supported by this family
 43 * @n_ops: number of operations supported by this family
 44 */
 45struct genl_family {
 46	int			id;		/* private */
 47	unsigned int		hdrsize;
 48	char			name[GENL_NAMSIZ];
 49	unsigned int		version;
 50	unsigned int		maxattr;
 51	bool			netnsok;
 52	bool			parallel_ops;
 53	const struct nla_policy *policy;
 54	int			(*pre_doit)(const struct genl_ops *ops,
 55					    struct sk_buff *skb,
 56					    struct genl_info *info);
 57	void			(*post_doit)(const struct genl_ops *ops,
 58					     struct sk_buff *skb,
 59					     struct genl_info *info);
 60	const struct genl_ops *	ops;
 61	const struct genl_multicast_group *mcgrps;
 62	unsigned int		n_ops;
 63	unsigned int		n_mcgrps;
 64	unsigned int		mcgrp_offset;	/* private */
 65	struct module		*module;
 66};
 67
 68/**
 69 * struct genl_info - receiving information
 70 * @snd_seq: sending sequence number
 71 * @snd_portid: netlink portid of sender
 72 * @nlhdr: netlink message header
 73 * @genlhdr: generic netlink message header
 74 * @userhdr: user specific header
 75 * @attrs: netlink attributes
 76 * @_net: network namespace
 77 * @user_ptr: user pointers
 78 * @extack: extended ACK report struct
 79 */
 80struct genl_info {
 81	u32			snd_seq;
 82	u32			snd_portid;
 83	struct nlmsghdr *	nlhdr;
 84	struct genlmsghdr *	genlhdr;
 85	void *			userhdr;
 86	struct nlattr **	attrs;
 87	possible_net_t		_net;
 
 
 88	void *			user_ptr[2];
 89	struct netlink_ext_ack *extack;
 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#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
103
104static inline int genl_err_attr(struct genl_info *info, int err,
105				const struct nlattr *attr)
106{
107	info->extack->bad_attr = attr;
108
109	return err;
110}
111
112enum genl_validate_flags {
113	GENL_DONT_VALIDATE_STRICT		= BIT(0),
114	GENL_DONT_VALIDATE_DUMP			= BIT(1),
115	GENL_DONT_VALIDATE_DUMP_STRICT		= BIT(2),
116};
117
118/**
119 * struct genl_info - info that is available during dumpit op call
120 * @family: generic netlink family - for internal genl code usage
121 * @ops: generic netlink ops - for internal genl code usage
122 * @attrs: netlink attributes
123 */
124struct genl_dumpit_info {
125	const struct genl_family *family;
126	const struct genl_ops *ops;
127	struct nlattr **attrs;
128};
129
130static inline const struct genl_dumpit_info *
131genl_dumpit_info(struct netlink_callback *cb)
132{
133	return cb->data;
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 * @validate: validation flags from enum genl_validate_flags
142 * @doit: standard command callback
143 * @start: start callback for dumps
144 * @dumpit: callback for dumpers
145 * @done: completion callback for dumps
 
146 */
147struct genl_ops {
 
 
 
 
148	int		       (*doit)(struct sk_buff *skb,
149				       struct genl_info *info);
150	int		       (*start)(struct netlink_callback *cb);
151	int		       (*dumpit)(struct sk_buff *skb,
152					 struct netlink_callback *cb);
153	int		       (*done)(struct netlink_callback *cb);
154	u8			cmd;
155	u8			internal_flags;
156	u8			flags;
157	u8			validate;
158};
159
160int genl_register_family(struct genl_family *family);
161int genl_unregister_family(const struct genl_family *family);
162void genl_notify(const struct genl_family *family, struct sk_buff *skb,
163		 struct genl_info *info, u32 group, gfp_t flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
164
165void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
166		  const struct genl_family *family, int flags, u8 cmd);
167
168/**
169 * genlmsg_nlhdr - Obtain netlink header from user specified header
170 * @user_hdr: user header as returned from genlmsg_put()
 
171 *
172 * Returns pointer to netlink header.
173 */
174static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
 
175{
176	return (struct nlmsghdr *)((char *)user_hdr -
 
177				   GENL_HDRLEN -
178				   NLMSG_HDRLEN);
179}
180
181/**
182 * genlmsg_parse_deprecated - parse attributes of a genetlink message
183 * @nlh: netlink message header
184 * @family: genetlink message family
185 * @tb: destination array with maxtype+1 elements
186 * @maxtype: maximum attribute type to be expected
187 * @policy: validation policy
188 * @extack: extended ACK report struct
189 */
190static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
191					   const struct genl_family *family,
192					   struct nlattr *tb[], int maxtype,
193					   const struct nla_policy *policy,
194					   struct netlink_ext_ack *extack)
195{
196	return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
197			     policy, NL_VALIDATE_LIBERAL, extack);
198}
199
200/**
201 * genlmsg_parse - parse attributes of a genetlink message
202 * @nlh: netlink message header
203 * @family: genetlink message family
204 * @tb: destination array with maxtype+1 elements
205 * @maxtype: maximum attribute type to be expected
206 * @policy: validation policy
207 * @extack: extended ACK report struct
208 */
209static inline int genlmsg_parse(const struct nlmsghdr *nlh,
210				const struct genl_family *family,
211				struct nlattr *tb[], int maxtype,
212				const struct nla_policy *policy,
213				struct netlink_ext_ack *extack)
214{
215	return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
216			     policy, NL_VALIDATE_STRICT, extack);
217}
218
219/**
220 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
221 * @cb: netlink callback structure that stores the sequence number
222 * @user_hdr: user header as returned from genlmsg_put()
 
223 *
224 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
225 * simpler to use with generic netlink.
226 */
227static inline void genl_dump_check_consistent(struct netlink_callback *cb,
228					      void *user_hdr)
 
229{
230	nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
231}
232
233/**
234 * genlmsg_put_reply - Add generic netlink header to a reply message
235 * @skb: socket buffer holding the message
236 * @info: receiver info
237 * @family: generic netlink family
238 * @flags: netlink message flags
239 * @cmd: generic netlink command
240 *
241 * Returns pointer to user specific header
242 */
243static inline void *genlmsg_put_reply(struct sk_buff *skb,
244				      struct genl_info *info,
245				      const struct genl_family *family,
246				      int flags, u8 cmd)
247{
248	return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
249			   flags, cmd);
250}
251
252/**
253 * genlmsg_end - Finalize a generic netlink message
254 * @skb: socket buffer the message is stored in
255 * @hdr: user specific header
256 */
257static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
258{
259	nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
260}
261
262/**
263 * genlmsg_cancel - Cancel construction of a generic netlink message
264 * @skb: socket buffer the message is stored in
265 * @hdr: generic netlink message header
266 */
267static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
268{
269	if (hdr)
270		nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
271}
272
273/**
274 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
275 * @family: the generic netlink family
276 * @net: the net namespace
277 * @skb: netlink message as socket buffer
278 * @portid: own netlink portid to avoid sending to yourself
279 * @group: offset of multicast group in groups array
280 * @flags: allocation flags
281 */
282static inline int genlmsg_multicast_netns(const struct genl_family *family,
283					  struct net *net, struct sk_buff *skb,
284					  u32 portid, unsigned int group, gfp_t flags)
285{
286	if (WARN_ON_ONCE(group >= family->n_mcgrps))
287		return -EINVAL;
288	group = family->mcgrp_offset + group;
289	return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
290}
291
292/**
293 * genlmsg_multicast - multicast a netlink message to the default netns
294 * @family: the generic netlink family
295 * @skb: netlink message as socket buffer
296 * @portid: own netlink portid to avoid sending to yourself
297 * @group: offset of multicast group in groups array
298 * @flags: allocation flags
299 */
300static inline int genlmsg_multicast(const struct genl_family *family,
301				    struct sk_buff *skb, u32 portid,
302				    unsigned int group, gfp_t flags)
303{
304	return genlmsg_multicast_netns(family, &init_net, skb,
305				       portid, group, flags);
306}
307
308/**
309 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
310 * @family: the generic netlink family
311 * @skb: netlink message as socket buffer
312 * @portid: own netlink portid to avoid sending to yourself
313 * @group: offset of multicast group in groups array
314 * @flags: allocation flags
315 *
316 * This function must hold the RTNL or rcu_read_lock().
317 */
318int genlmsg_multicast_allns(const struct genl_family *family,
319			    struct sk_buff *skb, u32 portid,
320			    unsigned int group, gfp_t flags);
321
322/**
323 * genlmsg_unicast - unicast a netlink message
324 * @skb: netlink message as socket buffer
325 * @portid: netlink portid of the destination socket
326 */
327static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
328{
329	return nlmsg_unicast(net->genl_sock, skb, portid);
330}
331
332/**
333 * genlmsg_reply - reply to a request
334 * @skb: netlink message to be sent back
335 * @info: receiver information
336 */
337static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
338{
339	return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
340}
341
342/**
343 * gennlmsg_data - head of message payload
344 * @gnlh: genetlink message header
345 */
346static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
347{
348	return ((unsigned char *) gnlh + GENL_HDRLEN);
349}
350
351/**
352 * genlmsg_len - length of message payload
353 * @gnlh: genetlink message header
354 */
355static inline int genlmsg_len(const struct genlmsghdr *gnlh)
356{
357	struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
358							NLMSG_HDRLEN);
359	return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
360}
361
362/**
363 * genlmsg_msg_size - length of genetlink message not including padding
364 * @payload: length of message payload
365 */
366static inline int genlmsg_msg_size(int payload)
367{
368	return GENL_HDRLEN + payload;
369}
370
371/**
372 * genlmsg_total_size - length of genetlink message including padding
373 * @payload: length of message payload
374 */
375static inline int genlmsg_total_size(int payload)
376{
377	return NLMSG_ALIGN(genlmsg_msg_size(payload));
378}
379
380/**
381 * genlmsg_new - Allocate a new generic netlink message
382 * @payload: size of the message payload
383 * @flags: the type of memory to allocate.
384 */
385static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
386{
387	return nlmsg_new(genlmsg_total_size(payload), flags);
388}
389
390/**
391 * genl_set_err - report error to genetlink broadcast listeners
392 * @family: the generic netlink family
393 * @net: the network namespace to report the error to
394 * @portid: the PORTID of a process that we want to skip (if any)
395 * @group: the broadcast group that will notice the error
396 * 	(this is the offset of the multicast group in the groups array)
397 * @code: error code, must be negative (as usual in kernelspace)
398 *
399 * This function returns the number of broadcast listeners that have set the
400 * NETLINK_RECV_NO_ENOBUFS socket option.
401 */
402static inline int genl_set_err(const struct genl_family *family,
403			       struct net *net, u32 portid,
404			       u32 group, int code)
405{
406	if (WARN_ON_ONCE(group >= family->n_mcgrps))
407		return -EINVAL;
408	group = family->mcgrp_offset + group;
409	return netlink_set_err(net->genl_sock, portid, group, code);
410}
411
412static inline int genl_has_listeners(const struct genl_family *family,
413				     struct net *net, unsigned int group)
414{
415	if (WARN_ON_ONCE(group >= family->n_mcgrps))
416		return -EINVAL;
417	group = family->mcgrp_offset + group;
418	return netlink_has_listeners(net->genl_sock, group);
419}
420#endif	/* __NET_GENERIC_NETLINK_H */