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 * @pre_doit: called before an operation's doit callback, it may
31 * do additional, common, filtering and return an error
32 * @post_doit: called after an operation's doit callback, it may
33 * undo operations done by pre_doit, for example release locks
34 * @attrbuf: buffer to store parsed attributes
35 * @family_list: family list
36 * @mcgrps: multicast groups used by this family (private)
37 * @n_mcgrps: number of multicast groups (private)
38 * @mcgrp_offset: starting number of multicast group IDs in this family
39 * @ops: the operations supported by this family (private)
40 * @n_ops: number of operations supported by this family (private)
45 char name[GENL_NAMSIZ];
50 int (*pre_doit)(const struct genl_ops *ops,
52 struct genl_info *info);
53 void (*post_doit)(const struct genl_ops *ops,
55 struct genl_info *info);
56 struct nlattr ** attrbuf; /* private */
57 const struct genl_ops * ops; /* private */
58 const struct genl_multicast_group *mcgrps; /* private */
59 unsigned int n_ops; /* private */
60 unsigned int n_mcgrps; /* private */
61 unsigned int mcgrp_offset; /* private */
62 struct list_head family_list; /* private */
63 struct module *module;
67 * struct genl_info - receiving information
68 * @snd_seq: sending sequence number
69 * @snd_portid: netlink portid of sender
70 * @nlhdr: netlink message header
71 * @genlhdr: generic netlink message header
72 * @userhdr: user specific header
73 * @attrs: netlink attributes
74 * @_net: network namespace
75 * @user_ptr: user pointers
80 struct nlmsghdr * nlhdr;
81 struct genlmsghdr * genlhdr;
83 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 * @dumpit: callback for dumpers
108 * @done: completion callback for dumps
109 * @ops_list: operations list
112 const struct nla_policy *policy;
113 int (*doit)(struct sk_buff *skb,
114 struct genl_info *info);
115 int (*dumpit)(struct sk_buff *skb,
116 struct netlink_callback *cb);
117 int (*done)(struct netlink_callback *cb);
123 int __genl_register_family(struct genl_family *family);
125 static inline int genl_register_family(struct genl_family *family)
127 family->module = THIS_MODULE;
128 return __genl_register_family(family);
132 * genl_register_family_with_ops - register a generic netlink family with ops
133 * @family: generic netlink family
134 * @ops: operations to be registered
135 * @n_ops: number of elements to register
137 * Registers the specified family and operations from the specified table.
138 * Only one family may be registered with the same family name or identifier.
140 * The family id may equal GENL_ID_GENERATE causing an unique id to
141 * be automatically generated and assigned.
143 * Either a doit or dumpit callback must be specified for every registered
144 * operation or the function will fail. Only one operation structure per
145 * command identifier may be registered.
147 * See include/net/genetlink.h for more documenation on the operations
150 * Return 0 on success or a negative error code.
153 _genl_register_family_with_ops_grps(struct genl_family *family,
154 const struct genl_ops *ops, size_t n_ops,
155 const struct genl_multicast_group *mcgrps,
158 family->module = THIS_MODULE;
160 family->n_ops = n_ops;
161 family->mcgrps = mcgrps;
162 family->n_mcgrps = n_mcgrps;
163 return __genl_register_family(family);
166 #define genl_register_family_with_ops(family, ops) \
167 _genl_register_family_with_ops_grps((family), \
168 (ops), ARRAY_SIZE(ops), \
170 #define genl_register_family_with_ops_groups(family, ops, grps) \
171 _genl_register_family_with_ops_grps((family), \
172 (ops), ARRAY_SIZE(ops), \
173 (grps), ARRAY_SIZE(grps))
175 int genl_unregister_family(struct genl_family *family);
176 void genl_notify(struct genl_family *family,
177 struct sk_buff *skb, struct net *net, u32 portid,
178 u32 group, struct nlmsghdr *nlh, gfp_t flags);
180 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
181 struct genl_family *family, int flags, u8 cmd);
184 * genlmsg_nlhdr - Obtain netlink header from user specified header
185 * @user_hdr: user header as returned from genlmsg_put()
186 * @family: generic netlink family
188 * Returns pointer to netlink header.
190 static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr,
191 struct genl_family *family)
193 return (struct nlmsghdr *)((char *)user_hdr -
200 * genl_dump_check_consistent - check if sequence is consistent and advertise if not
201 * @cb: netlink callback structure that stores the sequence number
202 * @user_hdr: user header as returned from genlmsg_put()
203 * @family: generic netlink family
205 * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it
206 * simpler to use with generic netlink.
208 static inline void genl_dump_check_consistent(struct netlink_callback *cb,
210 struct genl_family *family)
212 nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family));
216 * genlmsg_put_reply - Add generic netlink header to a reply message
217 * @skb: socket buffer holding the message
218 * @info: receiver info
219 * @family: generic netlink family
220 * @flags: netlink message flags
221 * @cmd: generic netlink command
223 * Returns pointer to user specific header
225 static inline void *genlmsg_put_reply(struct sk_buff *skb,
226 struct genl_info *info,
227 struct genl_family *family,
230 return genlmsg_put(skb, info->snd_portid, info->snd_seq, family,
235 * genlmsg_end - Finalize a generic netlink message
236 * @skb: socket buffer the message is stored in
237 * @hdr: user specific header
239 static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
241 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
245 * genlmsg_cancel - Cancel construction of a generic netlink message
246 * @skb: socket buffer the message is stored in
247 * @hdr: generic netlink message header
249 static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
252 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
256 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
257 * @family: the generic netlink family
258 * @net: the net namespace
259 * @skb: netlink message as socket buffer
260 * @portid: own netlink portid to avoid sending to yourself
261 * @group: offset of multicast group in groups array
262 * @flags: allocation flags
264 static inline int genlmsg_multicast_netns(struct genl_family *family,
265 struct net *net, struct sk_buff *skb,
266 u32 portid, unsigned int group, gfp_t flags)
268 if (WARN_ON_ONCE(group >= family->n_mcgrps))
270 group = family->mcgrp_offset + group;
271 return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
275 * genlmsg_multicast - multicast a netlink message to the default netns
276 * @family: the generic netlink family
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(struct genl_family *family,
283 struct sk_buff *skb, u32 portid,
284 unsigned int group, gfp_t flags)
286 return genlmsg_multicast_netns(family, &init_net, skb,
287 portid, group, flags);
291 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
292 * @family: the generic netlink family
293 * @skb: netlink message as socket buffer
294 * @portid: own netlink portid to avoid sending to yourself
295 * @group: offset of multicast group in groups array
296 * @flags: allocation flags
298 * This function must hold the RTNL or rcu_read_lock().
300 int genlmsg_multicast_allns(struct genl_family *family,
301 struct sk_buff *skb, u32 portid,
302 unsigned int group, gfp_t flags);
305 * genlmsg_unicast - unicast a netlink message
306 * @skb: netlink message as socket buffer
307 * @portid: netlink portid of the destination socket
309 static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid)
311 return nlmsg_unicast(net->genl_sock, skb, portid);
315 * genlmsg_reply - reply to a request
316 * @skb: netlink message to be sent back
317 * @info: receiver information
319 static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
321 return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid);
325 * gennlmsg_data - head of message payload
326 * @gnlh: genetlink message header
328 static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
330 return ((unsigned char *) gnlh + GENL_HDRLEN);
334 * genlmsg_len - length of message payload
335 * @gnlh: genetlink message header
337 static inline int genlmsg_len(const struct genlmsghdr *gnlh)
339 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
341 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
345 * genlmsg_msg_size - length of genetlink message not including padding
346 * @payload: length of message payload
348 static inline int genlmsg_msg_size(int payload)
350 return GENL_HDRLEN + payload;
354 * genlmsg_total_size - length of genetlink message including padding
355 * @payload: length of message payload
357 static inline int genlmsg_total_size(int payload)
359 return NLMSG_ALIGN(genlmsg_msg_size(payload));
363 * genlmsg_new - Allocate a new generic netlink message
364 * @payload: size of the message payload
365 * @flags: the type of memory to allocate.
367 static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
369 return nlmsg_new(genlmsg_total_size(payload), flags);
373 * genl_set_err - report error to genetlink broadcast listeners
374 * @family: the generic netlink family
375 * @net: the network namespace to report the error to
376 * @portid: the PORTID of a process that we want to skip (if any)
377 * @group: the broadcast group that will notice the error
378 * (this is the offset of the multicast group in the groups array)
379 * @code: error code, must be negative (as usual in kernelspace)
381 * This function returns the number of broadcast listeners that have set the
382 * NETLINK_RECV_NO_ENOBUFS socket option.
384 static inline int genl_set_err(struct genl_family *family, struct net *net,
385 u32 portid, u32 group, int code)
387 if (WARN_ON_ONCE(group >= family->n_mcgrps))
389 group = family->mcgrp_offset + group;
390 return netlink_set_err(net->genl_sock, portid, group, code);
393 #endif /* __NET_GENERIC_NETLINK_H */