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 * @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 * @attrbuf: buffer to store parsed attributes
40 * @family_list: family list
41 * @mcgrps: multicast groups used by this family (private)
42 * @n_mcgrps: number of multicast groups (private)
43 * @mcgrp_offset: starting number of multicast group IDs in this family
44 * @ops: the operations supported by this family (private)
45 * @n_ops: number of operations supported by this family (private)
50 char name[GENL_NAMSIZ];
55 int (*pre_doit)(const struct genl_ops *ops,
57 struct genl_info *info);
58 void (*post_doit)(const struct genl_ops *ops,
60 struct genl_info *info);
61 int (*mcast_bind)(struct net *net, int group);
62 void (*mcast_unbind)(struct net *net, int group);
63 struct nlattr ** attrbuf; /* private */
64 const struct genl_ops * ops; /* private */
65 const struct genl_multicast_group *mcgrps; /* private */
66 unsigned int n_ops; /* private */
67 unsigned int n_mcgrps; /* private */
68 unsigned int mcgrp_offset; /* private */
69 struct list_head family_list; /* private */
70 struct module *module;
74 * struct genl_info - receiving information
75 * @snd_seq: sending sequence number
76 * @snd_portid: netlink portid of sender
77 * @nlhdr: netlink message header
78 * @genlhdr: generic netlink message header
79 * @userhdr: user specific header
80 * @attrs: netlink attributes
81 * @_net: network namespace
82 * @user_ptr: user pointers
83 * @dst_sk: destination socket
88 struct nlmsghdr * nlhdr;
89 struct genlmsghdr * genlhdr;
91 struct nlattr ** attrs;
99 static inline struct net *genl_info_net(struct genl_info *info)
101 return read_pnet(&info->_net);
104 static inline void genl_info_net_set(struct genl_info *info, struct net *net)
106 write_pnet(&info->_net, net);
110 * struct genl_ops - generic netlink operations
111 * @cmd: command identifier
112 * @internal_flags: flags used by the family
114 * @policy: attribute validation policy
115 * @doit: standard command callback
116 * @dumpit: callback for dumpers
117 * @done: completion callback for dumps
118 * @ops_list: operations list
121 const struct nla_policy *policy;
122 int (*doit)(struct sk_buff *skb,
123 struct genl_info *info);
124 int (*dumpit)(struct sk_buff *skb,
125 struct netlink_callback *cb);
126 int (*done)(struct netlink_callback *cb);
132 int __genl_register_family(struct genl_family *family);
134 static inline int genl_register_family(struct genl_family *family)
136 family->module = THIS_MODULE;
137 return __genl_register_family(family);
141 * genl_register_family_with_ops - register a generic netlink family with ops
142 * @family: generic netlink family
143 * @ops: operations to be registered
144 * @n_ops: number of elements to register
146 * Registers the specified family and operations from the specified table.
147 * Only one family may be registered with the same family name or identifier.
149 * The family id may equal GENL_ID_GENERATE causing an unique id to
150 * be automatically generated and assigned.
152 * Either a doit or dumpit callback must be specified for every registered
153 * operation or the function will fail. Only one operation structure per
154 * command identifier may be registered.
156 * See include/net/genetlink.h for more documenation on the operations
159 * Return 0 on success or a negative error code.
162 _genl_register_family_with_ops_grps(struct genl_family *family,
163 const struct genl_ops *ops, size_t n_ops,
164 const struct genl_multicast_group *mcgrps,
167 family->module = THIS_MODULE;
169 family->n_ops = n_ops;
170 family->mcgrps = mcgrps;
171 family->n_mcgrps = n_mcgrps;
172 return __genl_register_family(family);
175 #define genl_register_family_with_ops(family, ops) \
176 _genl_register_family_with_ops_grps((family), \
177 (ops), ARRAY_SIZE(ops), \
179 #define genl_register_family_with_ops_groups(family, ops, grps) \
180 _genl_register_family_with_ops_grps((family), \
181 (ops), ARRAY_SIZE(ops), \
182 (grps), ARRAY_SIZE(grps))
184 int genl_unregister_family(struct genl_family *family);
185 void genl_notify(struct genl_family *family,
186 struct sk_buff *skb, struct net *net, u32 portid,
187 u32 group, struct nlmsghdr *nlh, gfp_t flags);
189 struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
191 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
192 struct genl_family *family, int flags, u8 cmd);
195 * genlmsg_nlhdr - Obtain netlink header from user specified header
196 * @user_hdr: user header as returned from genlmsg_put()
197 * @family: generic netlink family
199 * Returns pointer to netlink header.
201 static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
202 struct genl_family *family)
204 return (struct nlmsghdr *)((char *)user_hdr -
211 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
212 * @cb: netlink callback structure that stores the sequence number
213 * @user_hdr: user header as returned from genlmsg_put()
214 * @family: generic netlink family
216 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
217 * simpler to use with generic netlink.
219 static inline void genl_dump_check_consistent(struct netlink_callback *cb,
221 struct genl_family *family)
223 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
227 * genlmsg_put_reply - Add generic netlink header to a reply message
228 * @skb: socket buffer holding the message
229 * @info: receiver info
230 * @family: generic netlink family
231 * @flags: netlink message flags
232 * @cmd: generic netlink command
234 * Returns pointer to user specific header
236 static inline void *genlmsg_put_reply(struct sk_buff *skb,
237 struct genl_info *info,
238 struct genl_family *family,
241 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
246 * genlmsg_end - Finalize a generic netlink message
247 * @skb: socket buffer the message is stored in
248 * @hdr: user specific header
250 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
252 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
256 * genlmsg_cancel - Cancel construction of a generic netlink message
257 * @skb: socket buffer the message is stored in
258 * @hdr: generic netlink message header
260 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
263 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
267 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
268 * @family: the generic netlink family
269 * @net: the net namespace
270 * @skb: netlink message as socket buffer
271 * @portid: own netlink portid to avoid sending to yourself
272 * @group: offset of multicast group in groups array
273 * @flags: allocation flags
275 static inline int genlmsg_multicast_netns(struct genl_family *family,
276 struct net *net, struct sk_buff *skb,
277 u32 portid, unsigned int group, gfp_t flags)
279 if (WARN_ON_ONCE(group >= family->n_mcgrps))
281 group = family->mcgrp_offset + group;
282 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
286 * genlmsg_multicast - multicast a netlink message to the default netns
287 * @family: the generic netlink family
288 * @skb: netlink message as socket buffer
289 * @portid: own netlink portid to avoid sending to yourself
290 * @group: offset of multicast group in groups array
291 * @flags: allocation flags
293 static inline int genlmsg_multicast(struct genl_family *family,
294 struct sk_buff *skb, u32 portid,
295 unsigned int group, gfp_t flags)
297 return genlmsg_multicast_netns(family, &init_net, skb,
298 portid, group, flags);
302 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
303 * @family: the generic netlink family
304 * @skb: netlink message as socket buffer
305 * @portid: own netlink portid to avoid sending to yourself
306 * @group: offset of multicast group in groups array
307 * @flags: allocation flags
309 * This function must hold the RTNL or rcu_read_lock().
311 int genlmsg_multicast_allns(struct genl_family *family,
312 struct sk_buff *skb, u32 portid,
313 unsigned int group, gfp_t flags);
316 * genlmsg_unicast - unicast a netlink message
317 * @skb: netlink message as socket buffer
318 * @portid: netlink portid of the destination socket
320 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
322 return nlmsg_unicast(net->genl_sock, skb, portid);
326 * genlmsg_reply - reply to a request
327 * @skb: netlink message to be sent back
328 * @info: receiver information
330 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
332 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
336 * gennlmsg_data - head of message payload
337 * @gnlh: genetlink message header
339 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
341 return ((unsigned char *) gnlh + GENL_HDRLEN);
345 * genlmsg_len - length of message payload
346 * @gnlh: genetlink message header
348 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
350 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
352 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
356 * genlmsg_msg_size - length of genetlink message not including padding
357 * @payload: length of message payload
359 static inline int genlmsg_msg_size(int payload)
361 return GENL_HDRLEN + payload;
365 * genlmsg_total_size - length of genetlink message including padding
366 * @payload: length of message payload
368 static inline int genlmsg_total_size(int payload)
370 return NLMSG_ALIGN(genlmsg_msg_size(payload));
374 * genlmsg_new - Allocate a new generic netlink message
375 * @payload: size of the message payload
376 * @flags: the type of memory to allocate.
378 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
380 return nlmsg_new(genlmsg_total_size(payload), flags);
384 * genl_set_err - report error to genetlink broadcast listeners
385 * @family: the generic netlink family
386 * @net: the network namespace to report the error to
387 * @portid: the PORTID of a process that we want to skip (if any)
388 * @group: the broadcast group that will notice the error
389 * (this is the offset of the multicast group in the groups array)
390 * @code: error code, must be negative (as usual in kernelspace)
392 * This function returns the number of broadcast listeners that have set the
393 * NETLINK_RECV_NO_ENOBUFS socket option.
395 static inline int genl_set_err(struct genl_family *family, struct net *net,
396 u32 portid, u32 group, int code)
398 if (WARN_ON_ONCE(group >= family->n_mcgrps))
400 group = family->mcgrp_offset + group;
401 return netlink_set_err(net->genl_sock, portid, group, code);
404 static inline int genl_has_listeners(struct genl_family *family,
405 struct net *net, unsigned int group)
407 if (WARN_ON_ONCE(group >= family->n_mcgrps))
409 group = family->mcgrp_offset + group;
410 return netlink_has_listeners(net->genl_sock, group);
412 #endif /* __NET_GENERIC_NETLINK_H */