Loading...
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_GENERIC_NETLINK_H
3#define __NET_GENERIC_NETLINK_H
4
5#include <linux/genetlink.h>
6#include <net/netlink.h>
7#include <net/net_namespace.h>
8
9#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
10
11/**
12 * struct genl_multicast_group - generic netlink multicast group
13 * @name: name of the multicast group, names are per-family
14 */
15struct genl_multicast_group {
16 char name[GENL_NAMSIZ];
17};
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 * @netnsok: set to true if the family can handle network
30 * namespaces and should be presented in all of them
31 * @parallel_ops: operations can be called in parallel and aren't
32 * synchronized by the core genetlink code
33 * @pre_doit: called before an operation's doit callback, it may
34 * do additional, common, filtering and return an error
35 * @post_doit: called after an operation's doit callback, it may
36 * undo operations done by pre_doit, for example release locks
37 * @mcast_bind: a socket bound to the given multicast group (which
38 * is given as the offset into the groups array)
39 * @mcast_unbind: a socket was unbound from the given multicast group.
40 * Note that unbind() will not be called symmetrically if the
41 * generic netlink family is removed while there are still open
42 * sockets.
43 * @attrbuf: buffer to store parsed attributes (private)
44 * @mcgrps: multicast groups used by this family
45 * @n_mcgrps: number of multicast groups
46 * @mcgrp_offset: starting number of multicast group IDs in this family
47 * (private)
48 * @ops: the operations supported by this family
49 * @n_ops: number of operations supported by this family
50 */
51struct genl_family {
52 int id; /* private */
53 unsigned int hdrsize;
54 char name[GENL_NAMSIZ];
55 unsigned int version;
56 unsigned int maxattr;
57 bool netnsok;
58 bool parallel_ops;
59 int (*pre_doit)(const struct genl_ops *ops,
60 struct sk_buff *skb,
61 struct genl_info *info);
62 void (*post_doit)(const struct genl_ops *ops,
63 struct sk_buff *skb,
64 struct genl_info *info);
65 int (*mcast_bind)(struct net *net, int group);
66 void (*mcast_unbind)(struct net *net, int group);
67 struct nlattr ** attrbuf; /* private */
68 const struct genl_ops * ops;
69 const struct genl_multicast_group *mcgrps;
70 unsigned int n_ops;
71 unsigned int n_mcgrps;
72 unsigned int mcgrp_offset; /* private */
73 struct module *module;
74};
75
76struct nlattr **genl_family_attrbuf(const struct genl_family *family);
77
78/**
79 * struct genl_info - receiving information
80 * @snd_seq: sending sequence number
81 * @snd_portid: netlink portid of sender
82 * @nlhdr: netlink message header
83 * @genlhdr: generic netlink message header
84 * @userhdr: user specific header
85 * @attrs: netlink attributes
86 * @_net: network namespace
87 * @user_ptr: user pointers
88 * @extack: extended ACK report struct
89 */
90struct genl_info {
91 u32 snd_seq;
92 u32 snd_portid;
93 struct nlmsghdr * nlhdr;
94 struct genlmsghdr * genlhdr;
95 void * userhdr;
96 struct nlattr ** attrs;
97 possible_net_t _net;
98 void * user_ptr[2];
99 struct netlink_ext_ack *extack;
100};
101
102static inline struct net *genl_info_net(struct genl_info *info)
103{
104 return read_pnet(&info->_net);
105}
106
107static inline void genl_info_net_set(struct genl_info *info, struct net *net)
108{
109 write_pnet(&info->_net, net);
110}
111
112#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,
115 struct nlattr *attr)
116{
117 info->extack->bad_attr = attr;
118
119 return err;
120}
121
122/**
123 * struct genl_ops - generic netlink operations
124 * @cmd: command identifier
125 * @internal_flags: flags used by the family
126 * @flags: flags
127 * @policy: attribute validation policy
128 * @doit: standard command callback
129 * @start: start callback for dumps
130 * @dumpit: callback for dumpers
131 * @done: completion callback for dumps
132 */
133struct genl_ops {
134 const struct nla_policy *policy;
135 int (*doit)(struct sk_buff *skb,
136 struct genl_info *info);
137 int (*start)(struct netlink_callback *cb);
138 int (*dumpit)(struct sk_buff *skb,
139 struct netlink_callback *cb);
140 int (*done)(struct netlink_callback *cb);
141 u8 cmd;
142 u8 internal_flags;
143 u8 flags;
144};
145
146int genl_register_family(struct genl_family *family);
147int genl_unregister_family(const struct genl_family *family);
148void genl_notify(const struct genl_family *family, struct sk_buff *skb,
149 struct genl_info *info, u32 group, gfp_t flags);
150
151void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
152 const struct genl_family *family, int flags, u8 cmd);
153
154/**
155 * genlmsg_nlhdr - Obtain netlink header from user specified header
156 * @user_hdr: user header as returned from genlmsg_put()
157 *
158 * Returns pointer to netlink header.
159 */
160static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
161{
162 return (struct nlmsghdr *)((char *)user_hdr -
163 GENL_HDRLEN -
164 NLMSG_HDRLEN);
165}
166
167/**
168 * genlmsg_parse - parse attributes of a genetlink message
169 * @nlh: netlink message header
170 * @family: genetlink message family
171 * @tb: destination array with maxtype+1 elements
172 * @maxtype: maximum attribute type to be expected
173 * @policy: validation policy
174 * @extack: extended ACK report struct
175 */
176static inline int genlmsg_parse(const struct nlmsghdr *nlh,
177 const struct genl_family *family,
178 struct nlattr *tb[], int maxtype,
179 const struct nla_policy *policy,
180 struct netlink_ext_ack *extack)
181{
182 return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
183 policy, extack);
184}
185
186/**
187 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
188 * @cb: netlink callback structure that stores the sequence number
189 * @user_hdr: user header as returned from genlmsg_put()
190 *
191 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
192 * simpler to use with generic netlink.
193 */
194static inline void genl_dump_check_consistent(struct netlink_callback *cb,
195 void *user_hdr)
196{
197 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
198}
199
200/**
201 * genlmsg_put_reply - Add generic netlink header to a reply message
202 * @skb: socket buffer holding the message
203 * @info: receiver info
204 * @family: generic netlink family
205 * @flags: netlink message flags
206 * @cmd: generic netlink command
207 *
208 * Returns pointer to user specific header
209 */
210static inline void *genlmsg_put_reply(struct sk_buff *skb,
211 struct genl_info *info,
212 const struct genl_family *family,
213 int flags, u8 cmd)
214{
215 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
216 flags, cmd);
217}
218
219/**
220 * genlmsg_end - Finalize a generic netlink message
221 * @skb: socket buffer the message is stored in
222 * @hdr: user specific header
223 */
224static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
225{
226 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
227}
228
229/**
230 * genlmsg_cancel - Cancel construction of a generic netlink message
231 * @skb: socket buffer the message is stored in
232 * @hdr: generic netlink message header
233 */
234static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
235{
236 if (hdr)
237 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
238}
239
240/**
241 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
242 * @family: the generic netlink family
243 * @net: the net namespace
244 * @skb: netlink message as socket buffer
245 * @portid: own netlink portid to avoid sending to yourself
246 * @group: offset of multicast group in groups array
247 * @flags: allocation flags
248 */
249static inline int genlmsg_multicast_netns(const struct genl_family *family,
250 struct net *net, struct sk_buff *skb,
251 u32 portid, unsigned int group, gfp_t flags)
252{
253 if (WARN_ON_ONCE(group >= family->n_mcgrps))
254 return -EINVAL;
255 group = family->mcgrp_offset + group;
256 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
257}
258
259/**
260 * genlmsg_multicast - multicast a netlink message to the default netns
261 * @family: the generic netlink family
262 * @skb: netlink message as socket buffer
263 * @portid: own netlink portid to avoid sending to yourself
264 * @group: offset of multicast group in groups array
265 * @flags: allocation flags
266 */
267static inline int genlmsg_multicast(const struct genl_family *family,
268 struct sk_buff *skb, u32 portid,
269 unsigned int group, gfp_t flags)
270{
271 return genlmsg_multicast_netns(family, &init_net, skb,
272 portid, group, flags);
273}
274
275/**
276 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
277 * @family: the generic netlink family
278 * @skb: netlink message as socket buffer
279 * @portid: own netlink portid to avoid sending to yourself
280 * @group: offset of multicast group in groups array
281 * @flags: allocation flags
282 *
283 * This function must hold the RTNL or rcu_read_lock().
284 */
285int genlmsg_multicast_allns(const struct genl_family *family,
286 struct sk_buff *skb, u32 portid,
287 unsigned int group, gfp_t flags);
288
289/**
290 * genlmsg_unicast - unicast a netlink message
291 * @skb: netlink message as socket buffer
292 * @portid: netlink portid of the destination socket
293 */
294static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
295{
296 return nlmsg_unicast(net->genl_sock, skb, portid);
297}
298
299/**
300 * genlmsg_reply - reply to a request
301 * @skb: netlink message to be sent back
302 * @info: receiver information
303 */
304static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
305{
306 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
307}
308
309/**
310 * gennlmsg_data - head of message payload
311 * @gnlh: genetlink message header
312 */
313static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
314{
315 return ((unsigned char *) gnlh + GENL_HDRLEN);
316}
317
318/**
319 * genlmsg_len - length of message payload
320 * @gnlh: genetlink message header
321 */
322static inline int genlmsg_len(const struct genlmsghdr *gnlh)
323{
324 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
325 NLMSG_HDRLEN);
326 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
327}
328
329/**
330 * genlmsg_msg_size - length of genetlink message not including padding
331 * @payload: length of message payload
332 */
333static inline int genlmsg_msg_size(int payload)
334{
335 return GENL_HDRLEN + payload;
336}
337
338/**
339 * genlmsg_total_size - length of genetlink message including padding
340 * @payload: length of message payload
341 */
342static inline int genlmsg_total_size(int payload)
343{
344 return NLMSG_ALIGN(genlmsg_msg_size(payload));
345}
346
347/**
348 * genlmsg_new - Allocate a new generic netlink message
349 * @payload: size of the message payload
350 * @flags: the type of memory to allocate.
351 */
352static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
353{
354 return nlmsg_new(genlmsg_total_size(payload), flags);
355}
356
357/**
358 * genl_set_err - report error to genetlink broadcast listeners
359 * @family: the generic netlink family
360 * @net: the network namespace to report the error to
361 * @portid: the PORTID of a process that we want to skip (if any)
362 * @group: the broadcast group that will notice the error
363 * (this is the offset of the multicast group in the groups array)
364 * @code: error code, must be negative (as usual in kernelspace)
365 *
366 * This function returns the number of broadcast listeners that have set the
367 * NETLINK_RECV_NO_ENOBUFS socket option.
368 */
369static inline int genl_set_err(const struct genl_family *family,
370 struct net *net, u32 portid,
371 u32 group, int code)
372{
373 if (WARN_ON_ONCE(group >= family->n_mcgrps))
374 return -EINVAL;
375 group = family->mcgrp_offset + group;
376 return netlink_set_err(net->genl_sock, portid, group, code);
377}
378
379static inline int genl_has_listeners(const struct genl_family *family,
380 struct net *net, unsigned int group)
381{
382 if (WARN_ON_ONCE(group >= family->n_mcgrps))
383 return -EINVAL;
384 group = family->mcgrp_offset + group;
385 return netlink_has_listeners(net->genl_sock, group);
386}
387#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/* Binding to multicast group requires %CAP_NET_ADMIN */
12#define GENL_MCAST_CAP_NET_ADMIN BIT(0)
13/* Binding to multicast group requires %CAP_SYS_ADMIN */
14#define GENL_MCAST_CAP_SYS_ADMIN BIT(1)
15
16/**
17 * struct genl_multicast_group - generic netlink multicast group
18 * @name: name of the multicast group, names are per-family
19 * @flags: GENL_MCAST_* flags
20 */
21struct genl_multicast_group {
22 char name[GENL_NAMSIZ];
23 u8 flags;
24};
25
26struct genl_split_ops;
27struct genl_info;
28
29/**
30 * struct genl_family - generic netlink family
31 * @hdrsize: length of user specific header in bytes
32 * @name: name of family
33 * @version: protocol version
34 * @maxattr: maximum number of attributes supported
35 * @policy: netlink policy
36 * @netnsok: set to true if the family can handle network
37 * namespaces and should be presented in all of them
38 * @parallel_ops: operations can be called in parallel and aren't
39 * synchronized by the core genetlink code
40 * @pre_doit: called before an operation's doit callback, it may
41 * do additional, common, filtering and return an error
42 * @post_doit: called after an operation's doit callback, it may
43 * undo operations done by pre_doit, for example release locks
44 * @bind: called when family multicast group is added to a netlink socket
45 * @unbind: called when family multicast group is removed from a netlink socket
46 * @module: pointer to the owning module (set to THIS_MODULE)
47 * @mcgrps: multicast groups used by this family
48 * @n_mcgrps: number of multicast groups
49 * @resv_start_op: first operation for which reserved fields of the header
50 * can be validated and policies are required (see below);
51 * new families should leave this field at zero
52 * @ops: the operations supported by this family
53 * @n_ops: number of operations supported by this family
54 * @small_ops: the small-struct operations supported by this family
55 * @n_small_ops: number of small-struct operations supported by this family
56 * @split_ops: the split do/dump form of operation definition
57 * @n_split_ops: number of entries in @split_ops, not that with split do/dump
58 * ops the number of entries is not the same as number of commands
59 * @sock_priv_size: the size of per-socket private memory
60 * @sock_priv_init: the per-socket private memory initializer
61 * @sock_priv_destroy: the per-socket private memory destructor
62 *
63 * Attribute policies (the combination of @policy and @maxattr fields)
64 * can be attached at the family level or at the operation level.
65 * If both are present the per-operation policy takes precedence.
66 * For operations before @resv_start_op lack of policy means that the core
67 * will perform no attribute parsing or validation. For newer operations
68 * if policy is not provided core will reject all TLV attributes.
69 */
70struct genl_family {
71 unsigned int hdrsize;
72 char name[GENL_NAMSIZ];
73 unsigned int version;
74 unsigned int maxattr;
75 u8 netnsok:1;
76 u8 parallel_ops:1;
77 u8 n_ops;
78 u8 n_small_ops;
79 u8 n_split_ops;
80 u8 n_mcgrps;
81 u8 resv_start_op;
82 const struct nla_policy *policy;
83 int (*pre_doit)(const struct genl_split_ops *ops,
84 struct sk_buff *skb,
85 struct genl_info *info);
86 void (*post_doit)(const struct genl_split_ops *ops,
87 struct sk_buff *skb,
88 struct genl_info *info);
89 int (*bind)(int mcgrp);
90 void (*unbind)(int mcgrp);
91 const struct genl_ops * ops;
92 const struct genl_small_ops *small_ops;
93 const struct genl_split_ops *split_ops;
94 const struct genl_multicast_group *mcgrps;
95 struct module *module;
96
97 size_t sock_priv_size;
98 void (*sock_priv_init)(void *priv);
99 void (*sock_priv_destroy)(void *priv);
100
101/* private: internal use only */
102 /* protocol family identifier */
103 int id;
104 /* starting number of multicast group IDs in this family */
105 unsigned int mcgrp_offset;
106 /* list of per-socket privs */
107 struct xarray *sock_privs;
108};
109
110/**
111 * struct genl_info - receiving information
112 * @snd_seq: sending sequence number
113 * @snd_portid: netlink portid of sender
114 * @family: generic netlink family
115 * @nlhdr: netlink message header
116 * @genlhdr: generic netlink message header
117 * @attrs: netlink attributes
118 * @_net: network namespace
119 * @user_ptr: user pointers
120 * @extack: extended ACK report struct
121 */
122struct genl_info {
123 u32 snd_seq;
124 u32 snd_portid;
125 const struct genl_family *family;
126 const struct nlmsghdr * nlhdr;
127 struct genlmsghdr * genlhdr;
128 struct nlattr ** attrs;
129 possible_net_t _net;
130 void * user_ptr[2];
131 struct netlink_ext_ack *extack;
132};
133
134static inline struct net *genl_info_net(const struct genl_info *info)
135{
136 return read_pnet(&info->_net);
137}
138
139static inline void genl_info_net_set(struct genl_info *info, struct net *net)
140{
141 write_pnet(&info->_net, net);
142}
143
144static inline void *genl_info_userhdr(const struct genl_info *info)
145{
146 return (u8 *)info->genlhdr + GENL_HDRLEN;
147}
148
149#define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
150
151#define GENL_SET_ERR_MSG_FMT(info, msg, args...) \
152 NL_SET_ERR_MSG_FMT((info)->extack, msg, ##args)
153
154/* Report that a root attribute is missing */
155#define GENL_REQ_ATTR_CHECK(info, attr) ({ \
156 const struct genl_info *__info = (info); \
157 \
158 NL_REQ_ATTR_CHECK(__info->extack, NULL, __info->attrs, (attr)); \
159})
160
161enum genl_validate_flags {
162 GENL_DONT_VALIDATE_STRICT = BIT(0),
163 GENL_DONT_VALIDATE_DUMP = BIT(1),
164 GENL_DONT_VALIDATE_DUMP_STRICT = BIT(2),
165};
166
167/**
168 * struct genl_small_ops - generic netlink operations (small version)
169 * @cmd: command identifier
170 * @internal_flags: flags used by the family
171 * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM)
172 * @validate: validation flags from enum genl_validate_flags
173 * @doit: standard command callback
174 * @dumpit: callback for dumpers
175 *
176 * This is a cut-down version of struct genl_ops for users who don't need
177 * most of the ancillary infra and want to save space.
178 */
179struct genl_small_ops {
180 int (*doit)(struct sk_buff *skb, struct genl_info *info);
181 int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb);
182 u8 cmd;
183 u8 internal_flags;
184 u8 flags;
185 u8 validate;
186};
187
188/**
189 * struct genl_ops - generic netlink operations
190 * @cmd: command identifier
191 * @internal_flags: flags used by the family
192 * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM)
193 * @maxattr: maximum number of attributes supported
194 * @policy: netlink policy (takes precedence over family policy)
195 * @validate: validation flags from enum genl_validate_flags
196 * @doit: standard command callback
197 * @start: start callback for dumps
198 * @dumpit: callback for dumpers
199 * @done: completion callback for dumps
200 */
201struct genl_ops {
202 int (*doit)(struct sk_buff *skb,
203 struct genl_info *info);
204 int (*start)(struct netlink_callback *cb);
205 int (*dumpit)(struct sk_buff *skb,
206 struct netlink_callback *cb);
207 int (*done)(struct netlink_callback *cb);
208 const struct nla_policy *policy;
209 unsigned int maxattr;
210 u8 cmd;
211 u8 internal_flags;
212 u8 flags;
213 u8 validate;
214};
215
216/**
217 * struct genl_split_ops - generic netlink operations (do/dump split version)
218 * @cmd: command identifier
219 * @internal_flags: flags used by the family
220 * @flags: GENL_* flags (%GENL_ADMIN_PERM or %GENL_UNS_ADMIN_PERM)
221 * @validate: validation flags from enum genl_validate_flags
222 * @policy: netlink policy (takes precedence over family policy)
223 * @maxattr: maximum number of attributes supported
224 *
225 * Do callbacks:
226 * @pre_doit: called before an operation's @doit callback, it may
227 * do additional, common, filtering and return an error
228 * @doit: standard command callback
229 * @post_doit: called after an operation's @doit callback, it may
230 * undo operations done by pre_doit, for example release locks
231 *
232 * Dump callbacks:
233 * @start: start callback for dumps
234 * @dumpit: callback for dumpers
235 * @done: completion callback for dumps
236 *
237 * Do callbacks can be used if %GENL_CMD_CAP_DO is set in @flags.
238 * Dump callbacks can be used if %GENL_CMD_CAP_DUMP is set in @flags.
239 * Exactly one of those flags must be set.
240 */
241struct genl_split_ops {
242 union {
243 struct {
244 int (*pre_doit)(const struct genl_split_ops *ops,
245 struct sk_buff *skb,
246 struct genl_info *info);
247 int (*doit)(struct sk_buff *skb,
248 struct genl_info *info);
249 void (*post_doit)(const struct genl_split_ops *ops,
250 struct sk_buff *skb,
251 struct genl_info *info);
252 };
253 struct {
254 int (*start)(struct netlink_callback *cb);
255 int (*dumpit)(struct sk_buff *skb,
256 struct netlink_callback *cb);
257 int (*done)(struct netlink_callback *cb);
258 };
259 };
260 const struct nla_policy *policy;
261 unsigned int maxattr;
262 u8 cmd;
263 u8 internal_flags;
264 u8 flags;
265 u8 validate;
266};
267
268/**
269 * struct genl_dumpit_info - info that is available during dumpit op call
270 * @op: generic netlink ops - for internal genl code usage
271 * @attrs: netlink attributes
272 * @info: struct genl_info describing the request
273 */
274struct genl_dumpit_info {
275 struct genl_split_ops op;
276 struct genl_info info;
277};
278
279static inline const struct genl_dumpit_info *
280genl_dumpit_info(struct netlink_callback *cb)
281{
282 return cb->data;
283}
284
285static inline const struct genl_info *
286genl_info_dump(struct netlink_callback *cb)
287{
288 return &genl_dumpit_info(cb)->info;
289}
290
291/**
292 * genl_info_init_ntf() - initialize genl_info for notifications
293 * @info: genl_info struct to set up
294 * @family: pointer to the genetlink family
295 * @cmd: command to be used in the notification
296 *
297 * Initialize a locally declared struct genl_info to pass to various APIs.
298 * Intended to be used when creating notifications.
299 */
300static inline void
301genl_info_init_ntf(struct genl_info *info, const struct genl_family *family,
302 u8 cmd)
303{
304 struct genlmsghdr *hdr = (void *) &info->user_ptr[0];
305
306 memset(info, 0, sizeof(*info));
307 info->family = family;
308 info->genlhdr = hdr;
309 hdr->cmd = cmd;
310}
311
312static inline bool genl_info_is_ntf(const struct genl_info *info)
313{
314 return !info->nlhdr;
315}
316
317void *__genl_sk_priv_get(struct genl_family *family, struct sock *sk);
318void *genl_sk_priv_get(struct genl_family *family, struct sock *sk);
319int genl_register_family(struct genl_family *family);
320int genl_unregister_family(const struct genl_family *family);
321void genl_notify(const struct genl_family *family, struct sk_buff *skb,
322 struct genl_info *info, u32 group, gfp_t flags);
323
324void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
325 const struct genl_family *family, int flags, u8 cmd);
326
327static inline void *
328__genlmsg_iput(struct sk_buff *skb, const struct genl_info *info, int flags)
329{
330 return genlmsg_put(skb, info->snd_portid, info->snd_seq, info->family,
331 flags, info->genlhdr->cmd);
332}
333
334/**
335 * genlmsg_iput - start genetlink message based on genl_info
336 * @skb: skb in which message header will be placed
337 * @info: genl_info as provided to do/dump handlers
338 *
339 * Convenience wrapper which starts a genetlink message based on
340 * information in user request. @info should be either the struct passed
341 * by genetlink core to do/dump handlers (when constructing replies to
342 * such requests) or a struct initialized by genl_info_init_ntf()
343 * when constructing notifications.
344 *
345 * Returns pointer to new genetlink header.
346 */
347static inline void *
348genlmsg_iput(struct sk_buff *skb, const struct genl_info *info)
349{
350 return __genlmsg_iput(skb, info, 0);
351}
352
353/**
354 * genlmsg_nlhdr - Obtain netlink header from user specified header
355 * @user_hdr: user header as returned from genlmsg_put()
356 *
357 * Returns pointer to netlink header.
358 */
359static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr)
360{
361 return (struct nlmsghdr *)((char *)user_hdr -
362 GENL_HDRLEN -
363 NLMSG_HDRLEN);
364}
365
366/**
367 * genlmsg_parse_deprecated - parse attributes of a genetlink message
368 * @nlh: netlink message header
369 * @family: genetlink message family
370 * @tb: destination array with maxtype+1 elements
371 * @maxtype: maximum attribute type to be expected
372 * @policy: validation policy
373 * @extack: extended ACK report struct
374 */
375static inline int genlmsg_parse_deprecated(const struct nlmsghdr *nlh,
376 const struct genl_family *family,
377 struct nlattr *tb[], int maxtype,
378 const struct nla_policy *policy,
379 struct netlink_ext_ack *extack)
380{
381 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
382 policy, NL_VALIDATE_LIBERAL, extack);
383}
384
385/**
386 * genlmsg_parse - parse attributes of a genetlink message
387 * @nlh: netlink message header
388 * @family: genetlink message family
389 * @tb: destination array with maxtype+1 elements
390 * @maxtype: maximum attribute type to be expected
391 * @policy: validation policy
392 * @extack: extended ACK report struct
393 */
394static inline int genlmsg_parse(const struct nlmsghdr *nlh,
395 const struct genl_family *family,
396 struct nlattr *tb[], int maxtype,
397 const struct nla_policy *policy,
398 struct netlink_ext_ack *extack)
399{
400 return __nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
401 policy, NL_VALIDATE_STRICT, extack);
402}
403
404/**
405 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
406 * @cb: netlink callback structure that stores the sequence number
407 * @user_hdr: user header as returned from genlmsg_put()
408 *
409 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
410 * simpler to use with generic netlink.
411 */
412static inline void genl_dump_check_consistent(struct netlink_callback *cb,
413 void *user_hdr)
414{
415 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr));
416}
417
418/**
419 * genlmsg_put_reply - Add generic netlink header to a reply message
420 * @skb: socket buffer holding the message
421 * @info: receiver info
422 * @family: generic netlink family
423 * @flags: netlink message flags
424 * @cmd: generic netlink command
425 *
426 * Returns pointer to user specific header
427 */
428static inline void *genlmsg_put_reply(struct sk_buff *skb,
429 struct genl_info *info,
430 const struct genl_family *family,
431 int flags, u8 cmd)
432{
433 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
434 flags, cmd);
435}
436
437/**
438 * genlmsg_end - Finalize a generic netlink message
439 * @skb: socket buffer the message is stored in
440 * @hdr: user specific header
441 */
442static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
443{
444 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
445}
446
447/**
448 * genlmsg_cancel - Cancel construction of a generic netlink message
449 * @skb: socket buffer the message is stored in
450 * @hdr: generic netlink message header
451 */
452static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
453{
454 if (hdr)
455 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
456}
457
458/**
459 * genlmsg_multicast_netns_filtered - multicast a netlink message
460 * to a specific netns with filter
461 * function
462 * @family: the generic netlink family
463 * @net: the net namespace
464 * @skb: netlink message as socket buffer
465 * @portid: own netlink portid to avoid sending to yourself
466 * @group: offset of multicast group in groups array
467 * @flags: allocation flags
468 * @filter: filter function
469 * @filter_data: filter function private data
470 *
471 * Return: 0 on success, negative error code for failure.
472 */
473static inline int
474genlmsg_multicast_netns_filtered(const struct genl_family *family,
475 struct net *net, struct sk_buff *skb,
476 u32 portid, unsigned int group, gfp_t flags,
477 netlink_filter_fn filter,
478 void *filter_data)
479{
480 if (WARN_ON_ONCE(group >= family->n_mcgrps))
481 return -EINVAL;
482 group = family->mcgrp_offset + group;
483 return nlmsg_multicast_filtered(net->genl_sock, skb, portid, group,
484 flags, filter, filter_data);
485}
486
487/**
488 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
489 * @family: the generic netlink family
490 * @net: the net namespace
491 * @skb: netlink message as socket buffer
492 * @portid: own netlink portid to avoid sending to yourself
493 * @group: offset of multicast group in groups array
494 * @flags: allocation flags
495 */
496static inline int genlmsg_multicast_netns(const struct genl_family *family,
497 struct net *net, struct sk_buff *skb,
498 u32 portid, unsigned int group, gfp_t flags)
499{
500 return genlmsg_multicast_netns_filtered(family, net, skb, portid,
501 group, flags, NULL, NULL);
502}
503
504/**
505 * genlmsg_multicast - multicast a netlink message to the default netns
506 * @family: the generic netlink family
507 * @skb: netlink message as socket buffer
508 * @portid: own netlink portid to avoid sending to yourself
509 * @group: offset of multicast group in groups array
510 * @flags: allocation flags
511 */
512static inline int genlmsg_multicast(const struct genl_family *family,
513 struct sk_buff *skb, u32 portid,
514 unsigned int group, gfp_t flags)
515{
516 return genlmsg_multicast_netns(family, &init_net, skb,
517 portid, group, flags);
518}
519
520/**
521 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
522 * @family: the generic netlink family
523 * @skb: netlink message as socket buffer
524 * @portid: own netlink portid to avoid sending to yourself
525 * @group: offset of multicast group in groups array
526 * @flags: allocation flags
527 *
528 * This function must hold the RTNL or rcu_read_lock().
529 */
530int genlmsg_multicast_allns(const struct genl_family *family,
531 struct sk_buff *skb, u32 portid,
532 unsigned int group, gfp_t flags);
533
534/**
535 * genlmsg_unicast - unicast a netlink message
536 * @net: network namespace to look up @portid in
537 * @skb: netlink message as socket buffer
538 * @portid: netlink portid of the destination socket
539 */
540static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
541{
542 return nlmsg_unicast(net->genl_sock, skb, portid);
543}
544
545/**
546 * genlmsg_reply - reply to a request
547 * @skb: netlink message to be sent back
548 * @info: receiver information
549 */
550static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
551{
552 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
553}
554
555/**
556 * genlmsg_data - head of message payload
557 * @gnlh: genetlink message header
558 */
559static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
560{
561 return ((unsigned char *) gnlh + GENL_HDRLEN);
562}
563
564/**
565 * genlmsg_len - length of message payload
566 * @gnlh: genetlink message header
567 */
568static inline int genlmsg_len(const struct genlmsghdr *gnlh)
569{
570 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
571 NLMSG_HDRLEN);
572 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
573}
574
575/**
576 * genlmsg_msg_size - length of genetlink message not including padding
577 * @payload: length of message payload
578 */
579static inline int genlmsg_msg_size(int payload)
580{
581 return GENL_HDRLEN + payload;
582}
583
584/**
585 * genlmsg_total_size - length of genetlink message including padding
586 * @payload: length of message payload
587 */
588static inline int genlmsg_total_size(int payload)
589{
590 return NLMSG_ALIGN(genlmsg_msg_size(payload));
591}
592
593/**
594 * genlmsg_new - Allocate a new generic netlink message
595 * @payload: size of the message payload
596 * @flags: the type of memory to allocate.
597 */
598static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
599{
600 return nlmsg_new(genlmsg_total_size(payload), flags);
601}
602
603/**
604 * genl_set_err - report error to genetlink broadcast listeners
605 * @family: the generic netlink family
606 * @net: the network namespace to report the error to
607 * @portid: the PORTID of a process that we want to skip (if any)
608 * @group: the broadcast group that will notice the error
609 * (this is the offset of the multicast group in the groups array)
610 * @code: error code, must be negative (as usual in kernelspace)
611 *
612 * This function returns the number of broadcast listeners that have set the
613 * NETLINK_RECV_NO_ENOBUFS socket option.
614 */
615static inline int genl_set_err(const struct genl_family *family,
616 struct net *net, u32 portid,
617 u32 group, int code)
618{
619 if (WARN_ON_ONCE(group >= family->n_mcgrps))
620 return -EINVAL;
621 group = family->mcgrp_offset + group;
622 return netlink_set_err(net->genl_sock, portid, group, code);
623}
624
625static inline int genl_has_listeners(const struct genl_family *family,
626 struct net *net, unsigned int group)
627{
628 if (WARN_ON_ONCE(group >= family->n_mcgrps))
629 return -EINVAL;
630 group = family->mcgrp_offset + group;
631 return netlink_has_listeners(net->genl_sock, group);
632}
633#endif /* __NET_GENERIC_NETLINK_H */