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 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 * @attrbuf: buffer to store parsed attributes
37 * @family_list: family list
38 * @mcgrps: multicast groups used by this family (private)
39 * @n_mcgrps: number of multicast groups (private)
40 * @mcgrp_offset: starting number of multicast group IDs in this family
41 * @ops: the operations supported by this family (private)
42 * @n_ops: number of operations supported by this family (private)
47 char name[GENL_NAMSIZ];
52 int (*pre_doit)(const struct genl_ops *ops,
54 struct genl_info *info);
55 void (*post_doit)(const struct genl_ops *ops,
57 struct genl_info *info);
58 struct nlattr ** attrbuf; /* private */
59 const struct genl_ops * ops; /* private */
60 const struct genl_multicast_group *mcgrps; /* private */
61 unsigned int n_ops; /* private */
62 unsigned int n_mcgrps; /* private */
63 unsigned int mcgrp_offset; /* private */
64 struct list_head family_list; /* private */
65 struct module *module;
69 * struct genl_info - receiving information
70 * @snd_seq: sending sequence number
71 * @snd_portid: netlink portid of sender
72 * @nlhdr: netlink message header
73 * @genlhdr: generic netlink message header
74 * @userhdr: user specific header
75 * @attrs: netlink attributes
76 * @_net: network namespace
77 * @user_ptr: user pointers
82 struct nlmsghdr * nlhdr;
83 struct genlmsghdr * genlhdr;
85 struct nlattr ** attrs;
90 static inline struct net *genl_info_net(struct genl_info *info)
92 return read_pnet(&info->_net);
95 static inline void genl_info_net_set(struct genl_info *info, struct net *net)
97 write_pnet(&info->_net, net);
101 * struct genl_ops - generic netlink operations
102 * @cmd: command identifier
103 * @internal_flags: flags used by the family
105 * @policy: attribute validation policy
106 * @doit: standard command callback
107 * @start: start callback for dumps
108 * @dumpit: callback for dumpers
109 * @done: completion callback for dumps
110 * @ops_list: operations list
113 const struct nla_policy *policy;
114 int (*doit)(struct sk_buff *skb,
115 struct genl_info *info);
116 int (*start)(struct netlink_callback *cb);
117 int (*dumpit)(struct sk_buff *skb,
118 struct netlink_callback *cb);
119 int (*done)(struct netlink_callback *cb);
125 int __genl_register_family(struct genl_family *family);
127 static inline int genl_register_family(struct genl_family *family)
129 family->module = THIS_MODULE;
130 return __genl_register_family(family);
134 * genl_register_family_with_ops - register a generic netlink family with ops
135 * @family: generic netlink family
136 * @ops: operations to be registered
137 * @n_ops: number of elements to register
139 * Registers the specified family and operations from the specified table.
140 * Only one family may be registered with the same family name or identifier.
142 * The family id may equal GENL_ID_GENERATE causing an unique id to
143 * be automatically generated and assigned.
145 * Either a doit or dumpit callback must be specified for every registered
146 * operation or the function will fail. Only one operation structure per
147 * command identifier may be registered.
149 * See include/net/genetlink.h for more documenation on the operations
152 * Return 0 on success or a negative error code.
155 _genl_register_family_with_ops_grps(struct genl_family *family,
156 const struct genl_ops *ops, size_t n_ops,
157 const struct genl_multicast_group *mcgrps,
160 family->module = THIS_MODULE;
162 family->n_ops = n_ops;
163 family->mcgrps = mcgrps;
164 family->n_mcgrps = n_mcgrps;
165 return __genl_register_family(family);
168 #define genl_register_family_with_ops(family, ops) \
169 _genl_register_family_with_ops_grps((family), \
170 (ops), ARRAY_SIZE(ops), \
172 #define genl_register_family_with_ops_groups(family, ops, grps) \
173 _genl_register_family_with_ops_grps((family), \
174 (ops), ARRAY_SIZE(ops), \
175 (grps), ARRAY_SIZE(grps))
177 int genl_unregister_family(struct genl_family *family);
178 void genl_notify(struct genl_family *family, struct sk_buff *skb,
179 struct genl_info *info, u32 group, gfp_t flags);
181 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
182 struct genl_family *family, int flags, u8 cmd);
185 * genlmsg_nlhdr - Obtain netlink header from user specified header
186 * @user_hdr: user header as returned from genlmsg_put()
187 * @family: generic netlink family
189 * Returns pointer to netlink header.
191 static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
192 struct genl_family *family)
194 return (struct nlmsghdr *)((char *)user_hdr -
201 * genlmsg_parse - parse attributes of a genetlink message
202 * @nlh: netlink message header
203 * @family: genetlink message family
204 * @tb: destination array with maxtype+1 elements
205 * @maxtype: maximum attribute type to be expected
206 * @policy: validation policy
208 static inline int genlmsg_parse(const struct nlmsghdr *nlh,
209 const struct genl_family *family,
210 struct nlattr *tb[], int maxtype,
211 const struct nla_policy *policy)
213 return nlmsg_parse(nlh, family->hdrsize + GENL_HDRLEN, tb, maxtype,
218 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
219 * @cb: netlink callback structure that stores the sequence number
220 * @user_hdr: user header as returned from genlmsg_put()
221 * @family: generic netlink family
223 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
224 * simpler to use with generic netlink.
226 static inline void genl_dump_check_consistent(struct netlink_callback *cb,
228 struct genl_family *family)
230 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
234 * genlmsg_put_reply - Add generic netlink header to a reply message
235 * @skb: socket buffer holding the message
236 * @info: receiver info
237 * @family: generic netlink family
238 * @flags: netlink message flags
239 * @cmd: generic netlink command
241 * Returns pointer to user specific header
243 static inline void *genlmsg_put_reply(struct sk_buff *skb,
244 struct genl_info *info,
245 struct genl_family *family,
248 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
253 * genlmsg_end - Finalize a generic netlink message
254 * @skb: socket buffer the message is stored in
255 * @hdr: user specific header
257 static inline void genlmsg_end(struct sk_buff *skb, void *hdr)
259 nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
263 * genlmsg_cancel - Cancel construction of a generic netlink message
264 * @skb: socket buffer the message is stored in
265 * @hdr: generic netlink message header
267 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
270 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
274 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
275 * @family: the generic netlink family
276 * @net: the net namespace
277 * @skb: netlink message as socket buffer
278 * @portid: own netlink portid to avoid sending to yourself
279 * @group: offset of multicast group in groups array
280 * @flags: allocation flags
282 static inline int genlmsg_multicast_netns(struct genl_family *family,
283 struct net *net, struct sk_buff *skb,
284 u32 portid, unsigned int group, gfp_t flags)
286 if (WARN_ON_ONCE(group >= family->n_mcgrps))
288 group = family->mcgrp_offset + group;
289 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
293 * genlmsg_multicast - multicast a netlink message to the default netns
294 * @family: the generic netlink family
295 * @skb: netlink message as socket buffer
296 * @portid: own netlink portid to avoid sending to yourself
297 * @group: offset of multicast group in groups array
298 * @flags: allocation flags
300 static inline int genlmsg_multicast(struct genl_family *family,
301 struct sk_buff *skb, u32 portid,
302 unsigned int group, gfp_t flags)
304 return genlmsg_multicast_netns(family, &init_net, skb,
305 portid, group, flags);
309 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
310 * @family: the generic netlink family
311 * @skb: netlink message as socket buffer
312 * @portid: own netlink portid to avoid sending to yourself
313 * @group: offset of multicast group in groups array
314 * @flags: allocation flags
316 * This function must hold the RTNL or rcu_read_lock().
318 int genlmsg_multicast_allns(struct genl_family *family,
319 struct sk_buff *skb, u32 portid,
320 unsigned int group, gfp_t flags);
323 * genlmsg_unicast - unicast a netlink message
324 * @skb: netlink message as socket buffer
325 * @portid: netlink portid of the destination socket
327 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
329 return nlmsg_unicast(net->genl_sock, skb, portid);
333 * genlmsg_reply - reply to a request
334 * @skb: netlink message to be sent back
335 * @info: receiver information
337 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
339 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
343 * gennlmsg_data - head of message payload
344 * @gnlh: genetlink message header
346 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
348 return ((unsigned char *) gnlh + GENL_HDRLEN);
352 * genlmsg_len - length of message payload
353 * @gnlh: genetlink message header
355 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
357 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
359 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
363 * genlmsg_msg_size - length of genetlink message not including padding
364 * @payload: length of message payload
366 static inline int genlmsg_msg_size(int payload)
368 return GENL_HDRLEN + payload;
372 * genlmsg_total_size - length of genetlink message including padding
373 * @payload: length of message payload
375 static inline int genlmsg_total_size(int payload)
377 return NLMSG_ALIGN(genlmsg_msg_size(payload));
381 * genlmsg_new - Allocate a new generic netlink message
382 * @payload: size of the message payload
383 * @flags: the type of memory to allocate.
385 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
387 return nlmsg_new(genlmsg_total_size(payload), flags);
391 * genl_set_err - report error to genetlink broadcast listeners
392 * @family: the generic netlink family
393 * @net: the network namespace to report the error to
394 * @portid: the PORTID of a process that we want to skip (if any)
395 * @group: the broadcast group that will notice the error
396 * (this is the offset of the multicast group in the groups array)
397 * @code: error code, must be negative (as usual in kernelspace)
399 * This function returns the number of broadcast listeners that have set the
400 * NETLINK_RECV_NO_ENOBUFS socket option.
402 static inline int genl_set_err(struct genl_family *family, struct net *net,
403 u32 portid, u32 group, int code)
405 if (WARN_ON_ONCE(group >= family->n_mcgrps))
407 group = family->mcgrp_offset + group;
408 return netlink_set_err(net->genl_sock, portid, group, code);
411 static inline int genl_has_listeners(struct genl_family *family,
412 struct net *net, unsigned int group)
414 if (WARN_ON_ONCE(group >= family->n_mcgrps))
416 group = family->mcgrp_offset + group;
417 return netlink_has_listeners(net->genl_sock, group);
419 #endif /* __NET_GENERIC_NETLINK_H */