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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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/**
9 * struct genl_multicast_group - generic netlink multicast group
10 * @name: name of the multicast group, names are per-family
11 * @id: multicast group ID, assigned by the core, to use with
12 * genlmsg_multicast().
13 * @list: list entry for linking
14 * @family: pointer to family, need not be set before registering
15 */
16struct genl_multicast_group {
17 struct genl_family *family; /* private */
18 struct list_head list; /* private */
19 char name[GENL_NAMSIZ];
20 u32 id;
21};
22
23/**
24 * struct genl_family - generic netlink family
25 * @id: protocol family idenfitier
26 * @hdrsize: length of user specific header in bytes
27 * @name: name of family
28 * @version: protocol version
29 * @maxattr: maximum number of attributes supported
30 * @netnsok: set to true if the family can handle network
31 * namespaces and should be presented in all of them
32 * @attrbuf: buffer to store parsed attributes
33 * @ops_list: list of all assigned operations
34 * @family_list: family list
35 * @mcast_groups: multicast groups list
36 */
37struct genl_family {
38 unsigned int id;
39 unsigned int hdrsize;
40 char name[GENL_NAMSIZ];
41 unsigned int version;
42 unsigned int maxattr;
43 bool netnsok;
44 struct nlattr ** attrbuf; /* private */
45 struct list_head ops_list; /* private */
46 struct list_head family_list; /* private */
47 struct list_head mcast_groups; /* private */
48};
49
50/**
51 * struct genl_info - receiving information
52 * @snd_seq: sending sequence number
53 * @snd_pid: netlink pid of sender
54 * @nlhdr: netlink message header
55 * @genlhdr: generic netlink message header
56 * @userhdr: user specific header
57 * @attrs: netlink attributes
58 */
59struct genl_info {
60 u32 snd_seq;
61 u32 snd_pid;
62 struct nlmsghdr * nlhdr;
63 struct genlmsghdr * genlhdr;
64 void * userhdr;
65 struct nlattr ** attrs;
66#ifdef CONFIG_NET_NS
67 struct net * _net;
68#endif
69};
70
71#ifdef CONFIG_NET_NS
72static inline struct net *genl_info_net(struct genl_info *info)
73{
74 return info->_net;
75}
76
77static inline void genl_info_net_set(struct genl_info *info, struct net *net)
78{
79 info->_net = net;
80}
81#else
82static inline struct net *genl_info_net(struct genl_info *info)
83{
84 return &init_net;
85}
86
87static inline void genl_info_net_set(struct genl_info *info, struct net *net)
88{
89}
90#endif
91
92/**
93 * struct genl_ops - generic netlink operations
94 * @cmd: command identifier
95 * @flags: flags
96 * @policy: attribute validation policy
97 * @doit: standard command callback
98 * @dumpit: callback for dumpers
99 * @done: completion callback for dumps
100 * @ops_list: operations list
101 */
102struct genl_ops {
103 u8 cmd;
104 unsigned int flags;
105 const struct nla_policy *policy;
106 int (*doit)(struct sk_buff *skb,
107 struct genl_info *info);
108 int (*dumpit)(struct sk_buff *skb,
109 struct netlink_callback *cb);
110 int (*done)(struct netlink_callback *cb);
111 struct list_head ops_list;
112};
113
114extern int genl_register_family(struct genl_family *family);
115extern int genl_register_family_with_ops(struct genl_family *family,
116 struct genl_ops *ops, size_t n_ops);
117extern int genl_unregister_family(struct genl_family *family);
118extern int genl_register_ops(struct genl_family *, struct genl_ops *ops);
119extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops);
120extern int genl_register_mc_group(struct genl_family *family,
121 struct genl_multicast_group *grp);
122extern void genl_unregister_mc_group(struct genl_family *family,
123 struct genl_multicast_group *grp);
124
125/**
126 * genlmsg_put - Add generic netlink header to netlink message
127 * @skb: socket buffer holding the message
128 * @pid: netlink pid the message is addressed to
129 * @seq: sequence number (usually the one of the sender)
130 * @family: generic netlink family
131 * @flags netlink message flags
132 * @cmd: generic netlink command
133 *
134 * Returns pointer to user specific header
135 */
136static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
137 struct genl_family *family, int flags, u8 cmd)
138{
139 struct nlmsghdr *nlh;
140 struct genlmsghdr *hdr;
141
142 nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
143 family->hdrsize, flags);
144 if (nlh == NULL)
145 return NULL;
146
147 hdr = nlmsg_data(nlh);
148 hdr->cmd = cmd;
149 hdr->version = family->version;
150 hdr->reserved = 0;
151
152 return (char *) hdr + GENL_HDRLEN;
153}
154
155/**
156 * genlmsg_put_reply - Add generic netlink header to a reply message
157 * @skb: socket buffer holding the message
158 * @info: receiver info
159 * @family: generic netlink family
160 * @flags: netlink message flags
161 * @cmd: generic netlink command
162 *
163 * Returns pointer to user specific header
164 */
165static inline void *genlmsg_put_reply(struct sk_buff *skb,
166 struct genl_info *info,
167 struct genl_family *family,
168 int flags, u8 cmd)
169{
170 return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
171 flags, cmd);
172}
173
174/**
175 * genlmsg_end - Finalize a generic netlink message
176 * @skb: socket buffer the message is stored in
177 * @hdr: user specific header
178 */
179static inline int genlmsg_end(struct sk_buff *skb, void *hdr)
180{
181 return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
182}
183
184/**
185 * genlmsg_cancel - Cancel construction of a generic netlink message
186 * @skb: socket buffer the message is stored in
187 * @hdr: generic netlink message header
188 */
189static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
190{
191 nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
192}
193
194/**
195 * genlmsg_multicast_netns - multicast a netlink message to a specific netns
196 * @net: the net namespace
197 * @skb: netlink message as socket buffer
198 * @pid: own netlink pid to avoid sending to yourself
199 * @group: multicast group id
200 * @flags: allocation flags
201 */
202static inline int genlmsg_multicast_netns(struct net *net, struct sk_buff *skb,
203 u32 pid, unsigned int group, gfp_t flags)
204{
205 return nlmsg_multicast(net->genl_sock, skb, pid, group, flags);
206}
207
208/**
209 * genlmsg_multicast - multicast a netlink message to the default netns
210 * @skb: netlink message as socket buffer
211 * @pid: own netlink pid to avoid sending to yourself
212 * @group: multicast group id
213 * @flags: allocation flags
214 */
215static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid,
216 unsigned int group, gfp_t flags)
217{
218 return genlmsg_multicast_netns(&init_net, skb, pid, group, flags);
219}
220
221/**
222 * genlmsg_multicast_allns - multicast a netlink message to all net namespaces
223 * @skb: netlink message as socket buffer
224 * @pid: own netlink pid to avoid sending to yourself
225 * @group: multicast group id
226 * @flags: allocation flags
227 *
228 * This function must hold the RTNL or rcu_read_lock().
229 */
230int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid,
231 unsigned int group, gfp_t flags);
232
233/**
234 * genlmsg_unicast - unicast a netlink message
235 * @skb: netlink message as socket buffer
236 * @pid: netlink pid of the destination socket
237 */
238static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 pid)
239{
240 return nlmsg_unicast(net->genl_sock, skb, pid);
241}
242
243/**
244 * genlmsg_reply - reply to a request
245 * @skb: netlink message to be sent back
246 * @info: receiver information
247 */
248static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info)
249{
250 return genlmsg_unicast(genl_info_net(info), skb, info->snd_pid);
251}
252
253/**
254 * gennlmsg_data - head of message payload
255 * @gnlh: genetlink messsage header
256 */
257static inline void *genlmsg_data(const struct genlmsghdr *gnlh)
258{
259 return ((unsigned char *) gnlh + GENL_HDRLEN);
260}
261
262/**
263 * genlmsg_len - length of message payload
264 * @gnlh: genetlink message header
265 */
266static inline int genlmsg_len(const struct genlmsghdr *gnlh)
267{
268 struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh -
269 NLMSG_HDRLEN);
270 return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN);
271}
272
273/**
274 * genlmsg_msg_size - length of genetlink message not including padding
275 * @payload: length of message payload
276 */
277static inline int genlmsg_msg_size(int payload)
278{
279 return GENL_HDRLEN + payload;
280}
281
282/**
283 * genlmsg_total_size - length of genetlink message including padding
284 * @payload: length of message payload
285 */
286static inline int genlmsg_total_size(int payload)
287{
288 return NLMSG_ALIGN(genlmsg_msg_size(payload));
289}
290
291/**
292 * genlmsg_new - Allocate a new generic netlink message
293 * @payload: size of the message payload
294 * @flags: the type of memory to allocate.
295 */
296static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags)
297{
298 return nlmsg_new(genlmsg_total_size(payload), flags);
299}
300
301
302#endif /* __NET_GENERIC_NETLINK_H */