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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001/* SPDX-License-Identifier: GPL-2.0 */
Thomas Graf482a8522005-11-10 02:25:56 +01002#ifndef __NET_GENERIC_NETLINK_H
3#define __NET_GENERIC_NETLINK_H
4
5#include <linux/genetlink.h>
6#include <net/netlink.h>
Johannes Berg134e6372009-07-10 09:51:34 +00007#include <net/net_namespace.h>
Thomas Graf482a8522005-11-10 02:25:56 +01008
Thomas Graf58050fc2012-06-28 03:57:45 +00009#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
10
Thomas Graf482a8522005-11-10 02:25:56 +010011/**
Johannes Berg2dbba6f2007-07-18 15:47:52 -070012 * struct genl_multicast_group - generic netlink multicast group
13 * @name: name of the multicast group, names are per-family
Johannes Berg2dbba6f2007-07-18 15:47:52 -070014 */
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000015struct genl_multicast_group {
Johannes Berg2dbba6f2007-07-18 15:47:52 -070016 char name[GENL_NAMSIZ];
Johannes Berg2dbba6f2007-07-18 15:47:52 -070017};
18
Johannes Bergff4c92d2010-10-04 21:14:03 +020019struct genl_ops;
20struct genl_info;
21
Johannes Berg2dbba6f2007-07-18 15:47:52 -070022/**
Thomas Graf482a8522005-11-10 02:25:56 +010023 * struct genl_family - generic netlink family
Johannes Berga07ea4d2016-10-24 14:40:02 +020024 * @id: protocol family identifier (private)
Thomas Graf482a8522005-11-10 02:25:56 +010025 * @hdrsize: length of user specific header in bytes
26 * @name: name of family
27 * @version: protocol version
28 * @maxattr: maximum number of attributes supported
Johannes Berg3b0f31f2019-03-21 22:51:02 +010029 * @policy: netlink policy
Johannes Berg134e6372009-07-10 09:51:34 +000030 * @netnsok: set to true if the family can handle network
31 * namespaces and should be presented in all of them
Johannes Bergf555f3d2015-01-16 11:37:12 +010032 * @parallel_ops: operations can be called in parallel and aren't
33 * synchronized by the core genetlink code
Johannes Bergff4c92d2010-10-04 21:14:03 +020034 * @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
Johannes Bergc380d9a2014-12-23 20:54:40 +010038 * @mcast_bind: a socket bound to the given multicast group (which
39 * is given as the offset into the groups array)
Johannes Bergee1c24422015-01-16 11:37:14 +010040 * @mcast_unbind: a socket was unbound from the given multicast group.
41 * Note that unbind() will not be called symmetrically if the
42 * generic netlink family is removed while there are still open
43 * sockets.
Johannes Berg489111e2016-10-24 14:40:03 +020044 * @attrbuf: buffer to store parsed attributes (private)
Johannes Berg489111e2016-10-24 14:40:03 +020045 * @mcgrps: multicast groups used by this family
46 * @n_mcgrps: number of multicast groups
Johannes Berg2a94fe42013-11-19 15:19:39 +010047 * @mcgrp_offset: starting number of multicast group IDs in this family
Johannes Berg489111e2016-10-24 14:40:03 +020048 * (private)
49 * @ops: the operations supported by this family
50 * @n_ops: number of operations supported by this family
Thomas Graf482a8522005-11-10 02:25:56 +010051 */
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000052struct genl_family {
David S. Miller98e43212016-11-13 12:14:59 -050053 int id; /* private */
Thomas Graf482a8522005-11-10 02:25:56 +010054 unsigned int hdrsize;
55 char name[GENL_NAMSIZ];
56 unsigned int version;
57 unsigned int maxattr;
Johannes Berg134e6372009-07-10 09:51:34 +000058 bool netnsok;
Pravin B Shelardef311742013-04-23 07:48:30 +000059 bool parallel_ops;
Johannes Berg3b0f31f2019-03-21 22:51:02 +010060 const struct nla_policy *policy;
Johannes Bergf84f7712013-11-14 17:14:45 +010061 int (*pre_doit)(const struct genl_ops *ops,
Johannes Bergff4c92d2010-10-04 21:14:03 +020062 struct sk_buff *skb,
63 struct genl_info *info);
Johannes Bergf84f7712013-11-14 17:14:45 +010064 void (*post_doit)(const struct genl_ops *ops,
Johannes Bergff4c92d2010-10-04 21:14:03 +020065 struct sk_buff *skb,
66 struct genl_info *info);
Johannes Berg023e2cf2014-12-23 21:00:06 +010067 int (*mcast_bind)(struct net *net, int group);
68 void (*mcast_unbind)(struct net *net, int group);
Thomas Graf482a8522005-11-10 02:25:56 +010069 struct nlattr ** attrbuf; /* private */
Johannes Berg489111e2016-10-24 14:40:03 +020070 const struct genl_ops * ops;
71 const struct genl_multicast_group *mcgrps;
72 unsigned int n_ops;
73 unsigned int n_mcgrps;
Johannes Berg2a94fe42013-11-19 15:19:39 +010074 unsigned int mcgrp_offset; /* private */
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -070075 struct module *module;
Thomas Graf482a8522005-11-10 02:25:56 +010076};
77
Thomas Graf482a8522005-11-10 02:25:56 +010078/**
79 * struct genl_info - receiving information
80 * @snd_seq: sending sequence number
Eric W. Biederman15e47302012-09-07 20:12:54 +000081 * @snd_portid: netlink portid of sender
Thomas Graf482a8522005-11-10 02:25:56 +010082 * @nlhdr: netlink message header
83 * @genlhdr: generic netlink message header
84 * @userhdr: user specific header
85 * @attrs: netlink attributes
Johannes Bergff4c92d2010-10-04 21:14:03 +020086 * @_net: network namespace
87 * @user_ptr: user pointers
Johannes Berg7ab606d2017-04-12 14:34:05 +020088 * @extack: extended ACK report struct
Thomas Graf482a8522005-11-10 02:25:56 +010089 */
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +000090struct genl_info {
Thomas Graf482a8522005-11-10 02:25:56 +010091 u32 snd_seq;
Eric W. Biederman15e47302012-09-07 20:12:54 +000092 u32 snd_portid;
Thomas Graf482a8522005-11-10 02:25:56 +010093 struct nlmsghdr * nlhdr;
94 struct genlmsghdr * genlhdr;
95 void * userhdr;
96 struct nlattr ** attrs;
Eric W. Biederman0c5c9fb2015-03-11 23:06:44 -050097 possible_net_t _net;
Johannes Bergff4c92d2010-10-04 21:14:03 +020098 void * user_ptr[2];
Johannes Berg7ab606d2017-04-12 14:34:05 +020099 struct netlink_ext_ack *extack;
Thomas Graf482a8522005-11-10 02:25:56 +0100100};
101
Johannes Berg134e6372009-07-10 09:51:34 +0000102static inline struct net *genl_info_net(struct genl_info *info)
103{
Eric Dumazetc2d9ba92010-06-01 06:51:19 +0000104 return read_pnet(&info->_net);
Johannes Berg134e6372009-07-10 09:51:34 +0000105}
106
107static inline void genl_info_net_set(struct genl_info *info, struct net *net)
108{
Eric Dumazetc2d9ba92010-06-01 06:51:19 +0000109 write_pnet(&info->_net, net);
Johannes Berg134e6372009-07-10 09:51:34 +0000110}
Johannes Berg134e6372009-07-10 09:51:34 +0000111
Johannes Berg7ab606d2017-04-12 14:34:05 +0200112#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
113
114static inline int genl_err_attr(struct genl_info *info, int err,
Michal Kubecek6fce10f2018-08-28 18:51:58 +0200115 const struct nlattr *attr)
Johannes Berg7ab606d2017-04-12 14:34:05 +0200116{
117 info->extack->bad_attr = attr;
118
119 return err;
120}
121
Johannes Bergef6243a2019-04-26 14:07:31 +0200122enum genl_validate_flags {
123 GENL_DONT_VALIDATE_STRICT = BIT(0),
124 GENL_DONT_VALIDATE_DUMP = BIT(1),
125 GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
126};
127
Thomas Graf482a8522005-11-10 02:25:56 +0100128/**
Jiri Pirko1927f412019-10-05 20:04:34 +0200129 * struct genl_info - info that is available during dumpit op call
Jiri Pirkobf813b02019-10-05 20:04:36 +0200130 * @family: generic netlink family - for internal genl code usage
Jiri Pirko1927f412019-10-05 20:04:34 +0200131 * @ops: generic netlink ops - for internal genl code usage
Jiri Pirkobf813b02019-10-05 20:04:36 +0200132 * @attrs: netlink attributes
Jiri Pirko1927f412019-10-05 20:04:34 +0200133 */
134struct genl_dumpit_info {
Jiri Pirkobf813b02019-10-05 20:04:36 +0200135 const struct genl_family *family;
Jiri Pirko1927f412019-10-05 20:04:34 +0200136 const struct genl_ops *ops;
Jiri Pirkobf813b02019-10-05 20:04:36 +0200137 struct nlattr **attrs;
Jiri Pirko1927f412019-10-05 20:04:34 +0200138};
139
140static inline const struct genl_dumpit_info *
141genl_dumpit_info(struct netlink_callback *cb)
142{
143 return cb->data;
144}
145
146/**
Thomas Graf482a8522005-11-10 02:25:56 +0100147 * struct genl_ops - generic netlink operations
148 * @cmd: command identifier
Johannes Bergff4c92d2010-10-04 21:14:03 +0200149 * @internal_flags: flags used by the family
Thomas Graf482a8522005-11-10 02:25:56 +0100150 * @flags: flags
Thomas Graf482a8522005-11-10 02:25:56 +0100151 * @doit: standard command callback
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800152 * @start: start callback for dumps
Thomas Graf482a8522005-11-10 02:25:56 +0100153 * @dumpit: callback for dumpers
Jamal Hadi Salima4d13662006-12-01 20:07:42 -0800154 * @done: completion callback for dumps
Thomas Graf482a8522005-11-10 02:25:56 +0100155 */
Eric Dumazetfd2c3ef2009-11-03 03:26:03 +0000156struct genl_ops {
Thomas Graf482a8522005-11-10 02:25:56 +0100157 int (*doit)(struct sk_buff *skb,
158 struct genl_info *info);
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800159 int (*start)(struct netlink_callback *cb);
Thomas Graf482a8522005-11-10 02:25:56 +0100160 int (*dumpit)(struct sk_buff *skb,
161 struct netlink_callback *cb);
Jamal Hadi Salima4d13662006-12-01 20:07:42 -0800162 int (*done)(struct netlink_callback *cb);
Johannes Berg3f5ccd02013-11-14 17:14:47 +0100163 u8 cmd;
164 u8 internal_flags;
165 u8 flags;
Johannes Bergef6243a2019-04-26 14:07:31 +0200166 u8 validate;
Thomas Graf482a8522005-11-10 02:25:56 +0100167};
168
Johannes Berg489111e2016-10-24 14:40:03 +0200169int genl_register_family(struct genl_family *family);
Johannes Berg2ae0f172016-10-24 14:40:04 +0200170int genl_unregister_family(const struct genl_family *family);
171void genl_notify(const struct genl_family *family, struct sk_buff *skb,
Jiri Benc92c14d92015-09-22 18:56:43 +0200172 struct genl_info *info, u32 group, gfp_t flags);
Thomas Graf482a8522005-11-10 02:25:56 +0100173
Eric W. Biederman15e47302012-09-07 20:12:54 +0000174void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
Johannes Berg2ae0f172016-10-24 14:40:04 +0200175 const struct genl_family *family, int flags, u8 cmd);
Thomas Graf482a8522005-11-10 02:25:56 +0100176
177/**
Johannes Berg670dc282011-06-20 13:40:46 +0200178 * genlmsg_nlhdr - Obtain netlink header from user specified header
179 * @user_hdr: user header as returned from genlmsg_put()
Johannes Berg670dc282011-06-20 13:40:46 +0200180 *
181 * Returns pointer to netlink header.
182 */
Michal Kubecek0a833c22017-11-15 13:09:32 +0100183static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
Johannes Berg670dc282011-06-20 13:40:46 +0200184{
185 return (struct nlmsghdr *)((char *)user_hdr -
Johannes Berg670dc282011-06-20 13:40:46 +0200186 GENL_HDRLEN -
187 NLMSG_HDRLEN);
188}
189
190/**
Johannes Berg8cb08172019-04-26 14:07:28 +0200191 * genlmsg_parse_deprecated - parse attributes of a genetlink message
Joe Stringer7b1883c2015-01-21 16:42:51 -0800192 * @nlh: netlink message header
193 * @family: genetlink message family
194 * @tb: destination array with maxtype+1 elements
195 * @maxtype: maximum attribute type to be expected
196 * @policy: validation policy
Johannes Bergfceb6432017-04-12 14:34:07 +0200197 * @extack: extended ACK report struct
198 */
Johannes Berg8cb08172019-04-26 14:07:28 +0200199static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
200 const struct genl_family *family,
201 struct nlattr *tb[], int maxtype,
202 const struct nla_policy *policy,
203 struct netlink_ext_ack *extack)
Joe Stringer7b1883c2015-01-21 16:42:51 -0800204{
Johannes Berg8cb08172019-04-26 14:07:28 +0200205 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
206 policy, NL_VALIDATE_LIBERAL, extack);
Joe Stringer7b1883c2015-01-21 16:42:51 -0800207}
208
209/**
Johannes Berg3de64402019-04-26 14:07:29 +0200210 * genlmsg_parse - parse attributes of a genetlink message
211 * @nlh: netlink message header
212 * @family: genetlink message family
213 * @tb: destination array with maxtype+1 elements
214 * @maxtype: maximum attribute type to be expected
215 * @policy: validation policy
216 * @extack: extended ACK report struct
217 */
218static inline int genlmsg_parse(const struct nlmsghdr *nlh,
219 const struct genl_family *family,
220 struct nlattr *tb[], int maxtype,
221 const struct nla_policy *policy,
222 struct netlink_ext_ack *extack)
223{
224 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
225 policy, NL_VALIDATE_STRICT, extack);
226}
227
228/**
Johannes Berg670dc282011-06-20 13:40:46 +0200229 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
230 * @cb: netlink callback structure that stores the sequence number
231 * @user_hdr: user header as returned from genlmsg_put()
Johannes Berg670dc282011-06-20 13:40:46 +0200232 *
233 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
234 * simpler to use with generic netlink.
235 */
236static inline void genl_dump_check_consistent(struct netlink_callback *cb,
Michal Kubecek0a833c22017-11-15 13:09:32 +0100237 void *user_hdr)
Johannes Berg670dc282011-06-20 13:40:46 +0200238{
Michal Kubecek0a833c22017-11-15 13:09:32 +0100239 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
Johannes Berg670dc282011-06-20 13:40:46 +0200240}
241
242/**
Thomas Graf17c157c2006-11-14 19:46:02 -0800243 * genlmsg_put_reply - Add generic netlink header to a reply message
244 * @skb: socket buffer holding the message
245 * @info: receiver info
246 * @family: generic netlink family
247 * @flags: netlink message flags
248 * @cmd: generic netlink command
249 *
250 * Returns pointer to user specific header
251 */
252static inline void *genlmsg_put_reply(struct sk_buff *skb,
253 struct genl_info *info,
Johannes Berg2ae0f172016-10-24 14:40:04 +0200254 const struct genl_family *family,
Thomas Graf17c157c2006-11-14 19:46:02 -0800255 int flags, u8 cmd)
256{
Eric W. Biederman15e47302012-09-07 20:12:54 +0000257 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
Thomas Graf17c157c2006-11-14 19:46:02 -0800258 flags, cmd);
259}
260
261/**
Thomas Graf482a8522005-11-10 02:25:56 +0100262 * genlmsg_end - Finalize a generic netlink message
263 * @skb: socket buffer the message is stored in
264 * @hdr: user specific header
265 */
Johannes Berg053c0952015-01-16 22:09:00 +0100266static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
Thomas Graf482a8522005-11-10 02:25:56 +0100267{
Johannes Berg053c0952015-01-16 22:09:00 +0100268 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
Thomas Graf482a8522005-11-10 02:25:56 +0100269}
270
271/**
272 * genlmsg_cancel - Cancel construction of a generic netlink message
273 * @skb: socket buffer the message is stored in
274 * @hdr: generic netlink message header
275 */
Thomas Grafbc3ed282008-06-03 16:36:54 -0700276static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
Thomas Graf482a8522005-11-10 02:25:56 +0100277{
Julia Lawall38db9e12011-01-28 05:43:40 +0000278 if (hdr)
279 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
Thomas Graf482a8522005-11-10 02:25:56 +0100280}
281
282/**
Johannes Berg134e6372009-07-10 09:51:34 +0000283 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
Johannes Berg68eb5502013-11-19 15:19:38 +0100284 * @family: the generic netlink family
Johannes Berg134e6372009-07-10 09:51:34 +0000285 * @net: the net namespace
286 * @skb: netlink message as socket buffer
Eric W. Biederman15e47302012-09-07 20:12:54 +0000287 * @portid: own netlink portid to avoid sending to yourself
Johannes Berg2a94fe42013-11-19 15:19:39 +0100288 * @group: offset of multicast group in groups array
Johannes Berg134e6372009-07-10 09:51:34 +0000289 * @flags: allocation flags
290 */
Johannes Berg2ae0f172016-10-24 14:40:04 +0200291static inline int genlmsg_multicast_netns(const struct genl_family *family,
Johannes Berg68eb5502013-11-19 15:19:38 +0100292 struct net *net, struct sk_buff *skb,
Eric W. Biederman15e47302012-09-07 20:12:54 +0000293 u32 portid, unsigned int group, gfp_t flags)
Johannes Berg134e6372009-07-10 09:51:34 +0000294{
Johannes Berg220815a2013-11-21 18:17:04 +0100295 if (WARN_ON_ONCE(group >= family->n_mcgrps))
Johannes Berg2a94fe42013-11-19 15:19:39 +0100296 return -EINVAL;
297 group = family->mcgrp_offset + group;
Eric W. Biederman15e47302012-09-07 20:12:54 +0000298 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
Johannes Berg134e6372009-07-10 09:51:34 +0000299}
300
301/**
302 * genlmsg_multicast - multicast a netlink message to the default netns
Johannes Berg68eb5502013-11-19 15:19:38 +0100303 * @family: the generic netlink family
Thomas Graf482a8522005-11-10 02:25:56 +0100304 * @skb: netlink message as socket buffer
Eric W. Biederman15e47302012-09-07 20:12:54 +0000305 * @portid: own netlink portid to avoid sending to yourself
Johannes Berg2a94fe42013-11-19 15:19:39 +0100306 * @group: offset of multicast group in groups array
Thomas Grafd387f6a2006-08-15 00:31:06 -0700307 * @flags: allocation flags
Thomas Graf482a8522005-11-10 02:25:56 +0100308 */
Johannes Berg2ae0f172016-10-24 14:40:04 +0200309static inline int genlmsg_multicast(const struct genl_family *family,
Johannes Berg68eb5502013-11-19 15:19:38 +0100310 struct sk_buff *skb, u32 portid,
Thomas Grafd387f6a2006-08-15 00:31:06 -0700311 unsigned int group, gfp_t flags)
Thomas Graf482a8522005-11-10 02:25:56 +0100312{
Johannes Berg68eb5502013-11-19 15:19:38 +0100313 return genlmsg_multicast_netns(family, &init_net, skb,
314 portid, group, flags);
Thomas Graf482a8522005-11-10 02:25:56 +0100315}
316
317/**
Johannes Berg134e6372009-07-10 09:51:34 +0000318 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
Johannes Berg68eb5502013-11-19 15:19:38 +0100319 * @family: the generic netlink family
Johannes Berg134e6372009-07-10 09:51:34 +0000320 * @skb: netlink message as socket buffer
Eric W. Biederman15e47302012-09-07 20:12:54 +0000321 * @portid: own netlink portid to avoid sending to yourself
Johannes Berg2a94fe42013-11-19 15:19:39 +0100322 * @group: offset of multicast group in groups array
Johannes Berg134e6372009-07-10 09:51:34 +0000323 * @flags: allocation flags
324 *
325 * This function must hold the RTNL or rcu_read_lock().
326 */
Johannes Berg2ae0f172016-10-24 14:40:04 +0200327int genlmsg_multicast_allns(const struct genl_family *family,
Johannes Berg68eb5502013-11-19 15:19:38 +0100328 struct sk_buff *skb, u32 portid,
Johannes Berg134e6372009-07-10 09:51:34 +0000329 unsigned int group, gfp_t flags);
330
331/**
Thomas Graf482a8522005-11-10 02:25:56 +0100332 * genlmsg_unicast - unicast a netlink message
333 * @skb: netlink message as socket buffer
Eric W. Biederman15e47302012-09-07 20:12:54 +0000334 * @portid: netlink portid of the destination socket
Thomas Graf482a8522005-11-10 02:25:56 +0100335 */
Eric W. Biederman15e47302012-09-07 20:12:54 +0000336static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
Thomas Graf482a8522005-11-10 02:25:56 +0100337{
Eric W. Biederman15e47302012-09-07 20:12:54 +0000338 return nlmsg_unicast(net->genl_sock, skb, portid);
Thomas Graf482a8522005-11-10 02:25:56 +0100339}
340
Balbir Singhfb0ba6bd2006-07-14 00:24:39 -0700341/**
Thomas Graf81878d22006-11-14 19:45:27 -0800342 * genlmsg_reply - reply to a request
343 * @skb: netlink message to be sent back
344 * @info: receiver information
345 */
346static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
347{
Eric W. Biederman15e47302012-09-07 20:12:54 +0000348 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
Thomas Graf81878d22006-11-14 19:45:27 -0800349}
350
351/**
Balbir Singhfb0ba6bd2006-07-14 00:24:39 -0700352 * gennlmsg_data - head of message payload
Justin P. Mattock70f23fd2011-05-10 10:16:21 +0200353 * @gnlh: genetlink message header
Balbir Singhfb0ba6bd2006-07-14 00:24:39 -0700354 */
355static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
356{
357 return ((unsigned char *) gnlh + GENL_HDRLEN);
358}
359
360/**
361 * genlmsg_len - length of message payload
362 * @gnlh: genetlink message header
363 */
364static inline int genlmsg_len(const struct genlmsghdr *gnlh)
365{
366 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
367 NLMSG_HDRLEN);
368 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
369}
370
Balbir Singh17db9522006-09-30 23:28:51 -0700371/**
372 * genlmsg_msg_size - length of genetlink message not including padding
373 * @payload: length of message payload
374 */
375static inline int genlmsg_msg_size(int payload)
376{
377 return GENL_HDRLEN + payload;
378}
379
380/**
381 * genlmsg_total_size - length of genetlink message including padding
382 * @payload: length of message payload
383 */
384static inline int genlmsg_total_size(int payload)
385{
386 return NLMSG_ALIGN(genlmsg_msg_size(payload));
387}
388
Thomas Graf3dabc712006-11-14 19:44:52 -0800389/**
390 * genlmsg_new - Allocate a new generic netlink message
391 * @payload: size of the message payload
392 * @flags: the type of memory to allocate.
393 */
394static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
395{
396 return nlmsg_new(genlmsg_total_size(payload), flags);
397}
398
Johannes Berg62b68e92013-11-19 15:19:37 +0100399/**
400 * genl_set_err - report error to genetlink broadcast listeners
Johannes Berg68eb5502013-11-19 15:19:38 +0100401 * @family: the generic netlink family
Johannes Berg62b68e92013-11-19 15:19:37 +0100402 * @net: the network namespace to report the error to
403 * @portid: the PORTID of a process that we want to skip (if any)
404 * @group: the broadcast group that will notice the error
Johannes Berg2a94fe42013-11-19 15:19:39 +0100405 * (this is the offset of the multicast group in the groups array)
Johannes Berg62b68e92013-11-19 15:19:37 +0100406 * @code: error code, must be negative (as usual in kernelspace)
407 *
408 * This function returns the number of broadcast listeners that have set the
409 * NETLINK_RECV_NO_ENOBUFS socket option.
410 */
Johannes Berg2ae0f172016-10-24 14:40:04 +0200411static inline int genl_set_err(const struct genl_family *family,
412 struct net *net, u32 portid,
413 u32 group, int code)
Johannes Berg62b68e92013-11-19 15:19:37 +0100414{
Johannes Berg91398a02013-11-21 18:20:28 +0100415 if (WARN_ON_ONCE(group >= family->n_mcgrps))
416 return -EINVAL;
417 group = family->mcgrp_offset + group;
Johannes Berg62b68e92013-11-19 15:19:37 +0100418 return netlink_set_err(net->genl_sock, portid, group, code);
419}
Thomas Graf3dabc712006-11-14 19:44:52 -0800420
Johannes Berg2ae0f172016-10-24 14:40:04 +0200421static inline int genl_has_listeners(const struct genl_family *family,
Johannes Bergf8403a22014-12-22 18:56:36 +0100422 struct net *net, unsigned int group)
Nicolas Dichtel0d566372014-09-18 10:31:03 +0200423{
424 if (WARN_ON_ONCE(group >= family->n_mcgrps))
425 return -EINVAL;
426 group = family->mcgrp_offset + group;
Johannes Bergf8403a22014-12-22 18:56:36 +0100427 return netlink_has_listeners(net->genl_sock, group);
Nicolas Dichtel0d566372014-09-18 10:31:03 +0200428}
Thomas Graf482a8522005-11-10 02:25:56 +0100429#endif /* __NET_GENERIC_NETLINK_H */