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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 */
v4.10.11
  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 */