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1#ifndef __NET_GENERIC_NETLINK_H
2#define __NET_GENERIC_NETLINK_H
3
4#include <linux/genetlink.h>
5#include <net/netlink.h>
6#include <net/net_namespace.h>
7
8#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
9
10/**
11 * struct genl_multicast_group - generic netlink multicast group
12 * @name: name of the multicast group, names are per-family
13 */
14struct genl_multicast_group {
15 char name[GENL_NAMSIZ];
16};
17
18struct genl_ops;
19struct genl_info;
20
21/**
22 * struct genl_family - generic netlink family
23 * @id: protocol family idenfitier
24 * @hdrsize: length of user specific header in bytes
25 * @name: name of family
26 * @version: protocol version
27 * @maxattr: maximum number of attributes supported
28 * @netnsok: set to true if the family can handle network
29 * namespaces and should be presented in all of them
30 * @parallel_ops: operations can be called in parallel and aren't
31 * synchronized by the core genetlink code
32 * @pre_doit: called before an operation's doit callback, it may
33 * do additional, common, filtering and return an error
34 * @post_doit: called after an operation's doit callback, it may
35 * undo operations done by pre_doit, for example release locks
36 * @mcast_bind: a socket bound to the given multicast group (which
37 * is given as the offset into the groups array)
38 * @mcast_unbind: a socket was unbound from the given multicast group.
39 * Note that unbind() will not be called symmetrically if the
40 * generic netlink family is removed while there are still open
41 * sockets.
42 * @attrbuf: buffer to store parsed attributes
43 * @family_list: family list
44 * @mcgrps: multicast groups used by this family (private)
45 * @n_mcgrps: number of multicast groups (private)
46 * @mcgrp_offset: starting number of multicast group IDs in this family
47 * @ops: the operations supported by this family (private)
48 * @n_ops: number of operations supported by this family (private)
49 */
50struct genl_family {
51 unsigned int id;
52 unsigned int hdrsize;
53 char name[GENL_NAMSIZ];
54 unsigned int version;
55 unsigned int maxattr;
56 bool netnsok;
57 bool parallel_ops;
58 int (*pre_doit)(const struct genl_ops *ops,
59 struct sk_buff *skb,
60 struct genl_info *info);
61 void (*post_doit)(const struct genl_ops *ops,
62 struct sk_buff *skb,
63 struct genl_info *info);
64 int (*mcast_bind)(struct net *net, int group);
65 void (*mcast_unbind)(struct net *net, int group);
66 struct nlattr ** attrbuf; /* private */
67 const struct genl_ops * ops; /* private */
68 const struct genl_multicast_group *mcgrps; /* private */
69 unsigned int n_ops; /* private */
70 unsigned int n_mcgrps; /* private */
71 unsigned int mcgrp_offset; /* private */
72 struct list_head family_list; /* private */
73 struct module *module;
74};
75
76/**
77 * struct genl_info - receiving information
78 * @snd_seq: sending sequence number
79 * @snd_portid: netlink portid of sender
80 * @nlhdr: netlink message header
81 * @genlhdr: generic netlink message header
82 * @userhdr: user specific header
83 * @attrs: netlink attributes
84 * @_net: network namespace
85 * @user_ptr: user pointers
86 */
87struct genl_info {
88 u32 snd_seq;
89 u32 snd_portid;
90 struct nlmsghdr * nlhdr;
91 struct genlmsghdr * genlhdr;
92 void * userhdr;
93 struct nlattr ** attrs;
94 possible_net_t _net;
95 void * user_ptr[2];
96};
97
98static inline struct net *genl_info_net(struct genl_info *info)
99{
100 return read_pnet(&info->_net);
101}
102
103static inline void genl_info_net_set(struct genl_info *info, struct net *net)
104{
105 write_pnet(&info->_net, net);
106}
107
108/**
109 * struct genl_ops - generic netlink operations
110 * @cmd: command identifier
111 * @internal_flags: flags used by the family
112 * @flags: flags
113 * @policy: attribute validation policy
114 * @doit: standard command callback
115 * @start: start callback for dumps
116 * @dumpit: callback for dumpers
117 * @done: completion callback for dumps
118 * @ops_list: operations list
119 */
120struct genl_ops {
121 const struct nla_policy *policy;
122 int (*doit)(struct sk_buff *skb,
123 struct genl_info *info);
124 int (*start)(struct netlink_callback *cb);
125 int (*dumpit)(struct sk_buff *skb,
126 struct netlink_callback *cb);
127 int (*done)(struct netlink_callback *cb);
128 u8 cmd;
129 u8 internal_flags;
130 u8 flags;
131};
132
133int __genl_register_family(struct genl_family *family);
134
135static inline int genl_register_family(struct genl_family *family)
136{
137 family->module = THIS_MODULE;
138 return __genl_register_family(family);
139}
140
141/**
142 * genl_register_family_with_ops - register a generic netlink family with ops
143 * @family: generic netlink family
144 * @ops: operations to be registered
145 * @n_ops: number of elements to register
146 *
147 * Registers the specified family and operations from the specified table.
148 * Only one family may be registered with the same family name or identifier.
149 *
150 * The family id may equal GENL_ID_GENERATE causing an unique id to
151 * be automatically generated and assigned.
152 *
153 * Either a doit or dumpit callback must be specified for every registered
154 * operation or the function will fail. Only one operation structure per
155 * command identifier may be registered.
156 *
157 * See include/net/genetlink.h for more documenation on the operations
158 * structure.
159 *
160 * Return 0 on success or a negative error code.
161 */
162static inline int
163_genl_register_family_with_ops_grps(struct genl_family *family,
164 const struct genl_ops *ops, size_t n_ops,
165 const struct genl_multicast_group *mcgrps,
166 size_t n_mcgrps)
167{
168 family->module = THIS_MODULE;
169 family->ops = ops;
170 family->n_ops = n_ops;
171 family->mcgrps = mcgrps;
172 family->n_mcgrps = n_mcgrps;
173 return __genl_register_family(family);
174}
175
176#define genl_register_family_with_ops(family, ops) \
177 _genl_register_family_with_ops_grps((family), \
178 (ops), ARRAY_SIZE(ops), \
179 NULL, 0)
180#define genl_register_family_with_ops_groups(family, ops, grps) \
181 _genl_register_family_with_ops_grps((family), \
182 (ops), ARRAY_SIZE(ops), \
183 (grps), ARRAY_SIZE(grps))
184
185int genl_unregister_family(struct genl_family *family);
186void genl_notify(struct genl_family *family, struct sk_buff *skb,
187 struct genl_info *info, u32 group, gfp_t flags);
188
189void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
190 struct genl_family *family, int flags, u8 cmd);
191
192/**
193 * genlmsg_nlhdr - Obtain netlink header from user specified header
194 * @user_hdr: user header as returned from genlmsg_put()
195 * @family: generic netlink family
196 *
197 * Returns pointer to netlink header.
198 */
199static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
200 struct genl_family *family)
201{
202 return (struct nlmsghdr *)((char *)user_hdr -
203 family->hdrsize -
204 GENL_HDRLEN -
205 NLMSG_HDRLEN);
206}
207
208/**
209 * genlmsg_parse - parse attributes of a genetlink message
210 * @nlh: netlink message header
211 * @family: genetlink message family
212 * @tb: destination array with maxtype+1 elements
213 * @maxtype: maximum attribute type to be expected
214 * @policy: validation policy
215 * */
216static inline int genlmsg_parse(const struct nlmsghdr *nlh,
217 const struct genl_family *family,
218 struct nlattr *tb[], int maxtype,
219 const struct nla_policy *policy)
220{
221 return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
222 policy);
223}
224
225/**
226 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
227 * @cb: netlink callback structure that stores the sequence number
228 * @user_hdr: user header as returned from genlmsg_put()
229 * @family: generic netlink family
230 *
231 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
232 * simpler to use with generic netlink.
233 */
234static inline void genl_dump_check_consistent(struct netlink_callback *cb,
235 void *user_hdr,
236 struct genl_family *family)
237{
238 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
239}
240
241/**
242 * genlmsg_put_reply - Add generic netlink header to a reply message
243 * @skb: socket buffer holding the message
244 * @info: receiver info
245 * @family: generic netlink family
246 * @flags: netlink message flags
247 * @cmd: generic netlink command
248 *
249 * Returns pointer to user specific header
250 */
251static inline void *genlmsg_put_reply(struct sk_buff *skb,
252 struct genl_info *info,
253 struct genl_family *family,
254 int flags, u8 cmd)
255{
256 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
257 flags, cmd);
258}
259
260/**
261 * genlmsg_end - Finalize a generic netlink message
262 * @skb: socket buffer the message is stored in
263 * @hdr: user specific header
264 */
265static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
266{
267 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
268}
269
270/**
271 * genlmsg_cancel - Cancel construction of a generic netlink message
272 * @skb: socket buffer the message is stored in
273 * @hdr: generic netlink message header
274 */
275static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
276{
277 if (hdr)
278 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
279}
280
281/**
282 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
283 * @family: the generic netlink family
284 * @net: the net namespace
285 * @skb: netlink message as socket buffer
286 * @portid: own netlink portid to avoid sending to yourself
287 * @group: offset of multicast group in groups array
288 * @flags: allocation flags
289 */
290static inline int genlmsg_multicast_netns(struct genl_family *family,
291 struct net *net, struct sk_buff *skb,
292 u32 portid, unsigned int group, gfp_t flags)
293{
294 if (WARN_ON_ONCE(group >= family->n_mcgrps))
295 return -EINVAL;
296 group = family->mcgrp_offset + group;
297 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
298}
299
300/**
301 * genlmsg_multicast - multicast a netlink message to the default netns
302 * @family: the generic netlink family
303 * @skb: netlink message as socket buffer
304 * @portid: own netlink portid to avoid sending to yourself
305 * @group: offset of multicast group in groups array
306 * @flags: allocation flags
307 */
308static inline int genlmsg_multicast(struct genl_family *family,
309 struct sk_buff *skb, u32 portid,
310 unsigned int group, gfp_t flags)
311{
312 return genlmsg_multicast_netns(family, &init_net, skb,
313 portid, group, flags);
314}
315
316/**
317 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
318 * @family: the generic netlink family
319 * @skb: netlink message as socket buffer
320 * @portid: own netlink portid to avoid sending to yourself
321 * @group: offset of multicast group in groups array
322 * @flags: allocation flags
323 *
324 * This function must hold the RTNL or rcu_read_lock().
325 */
326int genlmsg_multicast_allns(struct genl_family *family,
327 struct sk_buff *skb, u32 portid,
328 unsigned int group, gfp_t flags);
329
330/**
331 * genlmsg_unicast - unicast a netlink message
332 * @skb: netlink message as socket buffer
333 * @portid: netlink portid of the destination socket
334 */
335static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
336{
337 return nlmsg_unicast(net->genl_sock, skb, portid);
338}
339
340/**
341 * genlmsg_reply - reply to a request
342 * @skb: netlink message to be sent back
343 * @info: receiver information
344 */
345static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
346{
347 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
348}
349
350/**
351 * gennlmsg_data - head of message payload
352 * @gnlh: genetlink message header
353 */
354static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
355{
356 return ((unsigned char *) gnlh + GENL_HDRLEN);
357}
358
359/**
360 * genlmsg_len - length of message payload
361 * @gnlh: genetlink message header
362 */
363static inline int genlmsg_len(const struct genlmsghdr *gnlh)
364{
365 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
366 NLMSG_HDRLEN);
367 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
368}
369
370/**
371 * genlmsg_msg_size - length of genetlink message not including padding
372 * @payload: length of message payload
373 */
374static inline int genlmsg_msg_size(int payload)
375{
376 return GENL_HDRLEN + payload;
377}
378
379/**
380 * genlmsg_total_size - length of genetlink message including padding
381 * @payload: length of message payload
382 */
383static inline int genlmsg_total_size(int payload)
384{
385 return NLMSG_ALIGN(genlmsg_msg_size(payload));
386}
387
388/**
389 * genlmsg_new - Allocate a new generic netlink message
390 * @payload: size of the message payload
391 * @flags: the type of memory to allocate.
392 */
393static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
394{
395 return nlmsg_new(genlmsg_total_size(payload), flags);
396}
397
398/**
399 * genl_set_err - report error to genetlink broadcast listeners
400 * @family: the generic netlink family
401 * @net: the network namespace to report the error to
402 * @portid: the PORTID of a process that we want to skip (if any)
403 * @group: the broadcast group that will notice the error
404 * (this is the offset of the multicast group in the groups array)
405 * @code: error code, must be negative (as usual in kernelspace)
406 *
407 * This function returns the number of broadcast listeners that have set the
408 * NETLINK_RECV_NO_ENOBUFS socket option.
409 */
410static inline int genl_set_err(struct genl_family *family, struct net *net,
411 u32 portid, u32 group, int code)
412{
413 if (WARN_ON_ONCE(group >= family->n_mcgrps))
414 return -EINVAL;
415 group = family->mcgrp_offset + group;
416 return netlink_set_err(net->genl_sock, portid, group, code);
417}
418
419static inline int genl_has_listeners(struct genl_family *family,
420 struct net *net, unsigned int group)
421{
422 if (WARN_ON_ONCE(group >= family->n_mcgrps))
423 return -EINVAL;
424 group = family->mcgrp_offset + group;
425 return netlink_has_listeners(net->genl_sock, group);
426}
427#endif /* __NET_GENERIC_NETLINK_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_GENERIC_NETLINK_H
3#define __NET_GENERIC_NETLINK_H
4
5#include <linux/genetlink.h>
6#include <net/netlink.h>
7#include <net/net_namespace.h>
8
9#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
10
11/* 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 */