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git.proxmox.com Git - mirror_ubuntu-focal-kernel.git/blob - include/net/genetlink.h
1 #ifndef __NET_GENERIC_NETLINK_H
2 #define __NET_GENERIC_NETLINK_H
4 #include <linux/genetlink.h>
5 #include <net/netlink.h>
6 #include <net/net_namespace.h>
8 #define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN)
11 * struct genl_multicast_group - generic netlink multicast group
12 * @name: name of the multicast group, names are per-family
14 struct genl_multicast_group
{
15 char name
[GENL_NAMSIZ
];
22 * struct genl_family - generic netlink family
23 * @id: protocol family identifier (private)
24 * @hdrsize: length of user specific header in bytes
25 * @name: name of family
26 * @version: protocol version
27 * @maxattr: maximum number of attributes supported
28 * @netnsok: set to true if the family can handle network
29 * namespaces and should be presented in all of them
30 * @parallel_ops: operations can be called in parallel and aren't
31 * synchronized by the core genetlink code
32 * @pre_doit: called before an operation's doit callback, it may
33 * do additional, common, filtering and return an error
34 * @post_doit: called after an operation's doit callback, it may
35 * undo operations done by pre_doit, for example release locks
36 * @mcast_bind: a socket bound to the given multicast group (which
37 * is given as the offset into the groups array)
38 * @mcast_unbind: a socket was unbound from the given multicast group.
39 * Note that unbind() will not be called symmetrically if the
40 * generic netlink family is removed while there are still open
42 * @attrbuf: buffer to store parsed attributes (private)
43 * @mcgrps: multicast groups used by this family
44 * @n_mcgrps: number of multicast groups
45 * @mcgrp_offset: starting number of multicast group IDs in this family
47 * @ops: the operations supported by this family
48 * @n_ops: number of operations supported by this family
53 char name
[GENL_NAMSIZ
];
58 int (*pre_doit
)(const struct genl_ops
*ops
,
60 struct genl_info
*info
);
61 void (*post_doit
)(const struct genl_ops
*ops
,
63 struct genl_info
*info
);
64 int (*mcast_bind
)(struct net
*net
, int group
);
65 void (*mcast_unbind
)(struct net
*net
, int group
);
66 struct nlattr
** attrbuf
; /* private */
67 const struct genl_ops
* ops
;
68 const struct genl_multicast_group
*mcgrps
;
70 unsigned int n_mcgrps
;
71 unsigned int mcgrp_offset
; /* private */
72 struct module
*module
;
75 struct nlattr
**genl_family_attrbuf(const struct genl_family
*family
);
78 * struct genl_info - receiving information
79 * @snd_seq: sending sequence number
80 * @snd_portid: netlink portid of sender
81 * @nlhdr: netlink message header
82 * @genlhdr: generic netlink message header
83 * @userhdr: user specific header
84 * @attrs: netlink attributes
85 * @_net: network namespace
86 * @user_ptr: user pointers
87 * @extack: extended ACK report struct
92 struct nlmsghdr
* nlhdr
;
93 struct genlmsghdr
* genlhdr
;
95 struct nlattr
** attrs
;
98 struct netlink_ext_ack
*extack
;
101 static inline struct net
*genl_info_net(struct genl_info
*info
)
103 return read_pnet(&info
->_net
);
106 static inline void genl_info_net_set(struct genl_info
*info
, struct net
*net
)
108 write_pnet(&info
->_net
, net
);
111 #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
113 static inline int genl_err_attr(struct genl_info
*info
, int err
,
116 info
->extack
->bad_attr
= attr
;
122 * struct genl_ops - generic netlink operations
123 * @cmd: command identifier
124 * @internal_flags: flags used by the family
126 * @policy: attribute validation policy
127 * @doit: standard command callback
128 * @start: start callback for dumps
129 * @dumpit: callback for dumpers
130 * @done: completion callback for dumps
133 const struct nla_policy
*policy
;
134 int (*doit
)(struct sk_buff
*skb
,
135 struct genl_info
*info
);
136 int (*start
)(struct netlink_callback
*cb
);
137 int (*dumpit
)(struct sk_buff
*skb
,
138 struct netlink_callback
*cb
);
139 int (*done
)(struct netlink_callback
*cb
);
145 int genl_register_family(struct genl_family
*family
);
146 int genl_unregister_family(const struct genl_family
*family
);
147 void genl_notify(const struct genl_family
*family
, struct sk_buff
*skb
,
148 struct genl_info
*info
, u32 group
, gfp_t flags
);
150 void *genlmsg_put(struct sk_buff
*skb
, u32 portid
, u32 seq
,
151 const struct genl_family
*family
, int flags
, u8 cmd
);
154 * genlmsg_nlhdr - Obtain netlink header from user specified header
155 * @user_hdr: user header as returned from genlmsg_put()
156 * @family: generic netlink family
158 * Returns pointer to netlink header.
160 static inline struct nlmsghdr
*
161 genlmsg_nlhdr(void *user_hdr
, const struct genl_family
*family
)
163 return (struct nlmsghdr
*)((char *)user_hdr
-
170 * genlmsg_parse - parse attributes of a genetlink message
171 * @nlh: netlink message header
172 * @family: genetlink message family
173 * @tb: destination array with maxtype+1 elements
174 * @maxtype: maximum attribute type to be expected
175 * @policy: validation policy
176 * @extack: extended ACK report struct
178 static inline int genlmsg_parse(const struct nlmsghdr
*nlh
,
179 const struct genl_family
*family
,
180 struct nlattr
*tb
[], int maxtype
,
181 const struct nla_policy
*policy
,
182 struct netlink_ext_ack
*extack
)
184 return nlmsg_parse(nlh
, family
->hdrsize
+ GENL_HDRLEN
, tb
, maxtype
,
189 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
190 * @cb: netlink callback structure that stores the sequence number
191 * @user_hdr: user header as returned from genlmsg_put()
192 * @family: generic netlink family
194 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
195 * simpler to use with generic netlink.
197 static inline void genl_dump_check_consistent(struct netlink_callback
*cb
,
199 const struct genl_family
*family
)
201 nl_dump_check_consistent(cb
, genlmsg_nlhdr(user_hdr
, family
));
205 * genlmsg_put_reply - Add generic netlink header to a reply message
206 * @skb: socket buffer holding the message
207 * @info: receiver info
208 * @family: generic netlink family
209 * @flags: netlink message flags
210 * @cmd: generic netlink command
212 * Returns pointer to user specific header
214 static inline void *genlmsg_put_reply(struct sk_buff
*skb
,
215 struct genl_info
*info
,
216 const struct genl_family
*family
,
219 return genlmsg_put(skb
, info
->snd_portid
, info
->snd_seq
, family
,
224 * genlmsg_end - Finalize a generic netlink message
225 * @skb: socket buffer the message is stored in
226 * @hdr: user specific header
228 static inline void genlmsg_end(struct sk_buff
*skb
, void *hdr
)
230 nlmsg_end(skb
, hdr
- GENL_HDRLEN
- NLMSG_HDRLEN
);
234 * genlmsg_cancel - Cancel construction of a generic netlink message
235 * @skb: socket buffer the message is stored in
236 * @hdr: generic netlink message header
238 static inline void genlmsg_cancel(struct sk_buff
*skb
, void *hdr
)
241 nlmsg_cancel(skb
, hdr
- GENL_HDRLEN
- NLMSG_HDRLEN
);
245 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
246 * @family: the generic netlink family
247 * @net: the net namespace
248 * @skb: netlink message as socket buffer
249 * @portid: own netlink portid to avoid sending to yourself
250 * @group: offset of multicast group in groups array
251 * @flags: allocation flags
253 static inline int genlmsg_multicast_netns(const struct genl_family
*family
,
254 struct net
*net
, struct sk_buff
*skb
,
255 u32 portid
, unsigned int group
, gfp_t flags
)
257 if (WARN_ON_ONCE(group
>= family
->n_mcgrps
))
259 group
= family
->mcgrp_offset
+ group
;
260 return nlmsg_multicast(net
->genl_sock
, skb
, portid
, group
, flags
);
264 * genlmsg_multicast - multicast a netlink message to the default netns
265 * @family: the generic netlink family
266 * @skb: netlink message as socket buffer
267 * @portid: own netlink portid to avoid sending to yourself
268 * @group: offset of multicast group in groups array
269 * @flags: allocation flags
271 static inline int genlmsg_multicast(const struct genl_family
*family
,
272 struct sk_buff
*skb
, u32 portid
,
273 unsigned int group
, gfp_t flags
)
275 return genlmsg_multicast_netns(family
, &init_net
, skb
,
276 portid
, group
, flags
);
280 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
281 * @family: the generic netlink family
282 * @skb: netlink message as socket buffer
283 * @portid: own netlink portid to avoid sending to yourself
284 * @group: offset of multicast group in groups array
285 * @flags: allocation flags
287 * This function must hold the RTNL or rcu_read_lock().
289 int genlmsg_multicast_allns(const struct genl_family
*family
,
290 struct sk_buff
*skb
, u32 portid
,
291 unsigned int group
, gfp_t flags
);
294 * genlmsg_unicast - unicast a netlink message
295 * @skb: netlink message as socket buffer
296 * @portid: netlink portid of the destination socket
298 static inline int genlmsg_unicast(struct net
*net
, struct sk_buff
*skb
, u32 portid
)
300 return nlmsg_unicast(net
->genl_sock
, skb
, portid
);
304 * genlmsg_reply - reply to a request
305 * @skb: netlink message to be sent back
306 * @info: receiver information
308 static inline int genlmsg_reply(struct sk_buff
*skb
, struct genl_info
*info
)
310 return genlmsg_unicast(genl_info_net(info
), skb
, info
->snd_portid
);
314 * gennlmsg_data - head of message payload
315 * @gnlh: genetlink message header
317 static inline void *genlmsg_data(const struct genlmsghdr
*gnlh
)
319 return ((unsigned char *) gnlh
+ GENL_HDRLEN
);
323 * genlmsg_len - length of message payload
324 * @gnlh: genetlink message header
326 static inline int genlmsg_len(const struct genlmsghdr
*gnlh
)
328 struct nlmsghdr
*nlh
= (struct nlmsghdr
*)((unsigned char *)gnlh
-
330 return (nlh
->nlmsg_len
- GENL_HDRLEN
- NLMSG_HDRLEN
);
334 * genlmsg_msg_size - length of genetlink message not including padding
335 * @payload: length of message payload
337 static inline int genlmsg_msg_size(int payload
)
339 return GENL_HDRLEN
+ payload
;
343 * genlmsg_total_size - length of genetlink message including padding
344 * @payload: length of message payload
346 static inline int genlmsg_total_size(int payload
)
348 return NLMSG_ALIGN(genlmsg_msg_size(payload
));
352 * genlmsg_new - Allocate a new generic netlink message
353 * @payload: size of the message payload
354 * @flags: the type of memory to allocate.
356 static inline struct sk_buff
*genlmsg_new(size_t payload
, gfp_t flags
)
358 return nlmsg_new(genlmsg_total_size(payload
), flags
);
362 * genl_set_err - report error to genetlink broadcast listeners
363 * @family: the generic netlink family
364 * @net: the network namespace to report the error to
365 * @portid: the PORTID of a process that we want to skip (if any)
366 * @group: the broadcast group that will notice the error
367 * (this is the offset of the multicast group in the groups array)
368 * @code: error code, must be negative (as usual in kernelspace)
370 * This function returns the number of broadcast listeners that have set the
371 * NETLINK_RECV_NO_ENOBUFS socket option.
373 static inline int genl_set_err(const struct genl_family
*family
,
374 struct net
*net
, u32 portid
,
377 if (WARN_ON_ONCE(group
>= family
->n_mcgrps
))
379 group
= family
->mcgrp_offset
+ group
;
380 return netlink_set_err(net
->genl_sock
, portid
, group
, code
);
383 static inline int genl_has_listeners(const struct genl_family
*family
,
384 struct net
*net
, unsigned int group
)
386 if (WARN_ON_ONCE(group
>= family
->n_mcgrps
))
388 group
= family
->mcgrp_offset
+ group
;
389 return netlink_has_listeners(net
->genl_sock
, group
);
391 #endif /* __NET_GENERIC_NETLINK_H */