diff options
-rw-r--r-- | include/linux/genetlink.h | 51 | ||||
-rw-r--r-- | include/net/genetlink.h | 154 | ||||
-rw-r--r-- | net/netlink/Makefile | 2 | ||||
-rw-r--r-- | net/netlink/genetlink.c | 579 |
4 files changed, 785 insertions, 1 deletions
diff --git a/include/linux/genetlink.h b/include/linux/genetlink.h new file mode 100644 index 000000000000..84f12a41dc01 --- /dev/null +++ b/include/linux/genetlink.h | |||
@@ -0,0 +1,51 @@ | |||
1 | #ifndef __LINUX_GENERIC_NETLINK_H | ||
2 | #define __LINUX_GENERIC_NETLINK_H | ||
3 | |||
4 | #include <linux/netlink.h> | ||
5 | |||
6 | #define GENL_NAMSIZ 16 /* length of family name */ | ||
7 | |||
8 | #define GENL_MIN_ID NLMSG_MIN_TYPE | ||
9 | #define GENL_MAX_ID 1023 | ||
10 | |||
11 | struct genlmsghdr { | ||
12 | __u8 cmd; | ||
13 | __u8 version; | ||
14 | __u16 reserved; | ||
15 | }; | ||
16 | |||
17 | #define GENL_HDRLEN NLMSG_ALIGN(sizeof(struct genlmsghdr)) | ||
18 | |||
19 | /* | ||
20 | * List of reserved static generic netlink identifiers: | ||
21 | */ | ||
22 | #define GENL_ID_GENERATE 0 | ||
23 | #define GENL_ID_CTRL NLMSG_MIN_TYPE | ||
24 | |||
25 | /************************************************************************** | ||
26 | * Controller | ||
27 | **************************************************************************/ | ||
28 | |||
29 | enum { | ||
30 | CTRL_CMD_UNSPEC, | ||
31 | CTRL_CMD_NEWFAMILY, | ||
32 | CTRL_CMD_DELFAMILY, | ||
33 | CTRL_CMD_GETFAMILY, | ||
34 | CTRL_CMD_NEWOPS, | ||
35 | CTRL_CMD_DELOPS, | ||
36 | CTRL_CMD_GETOPS, | ||
37 | __CTRL_CMD_MAX, | ||
38 | }; | ||
39 | |||
40 | #define CTRL_CMD_MAX (__CTRL_CMD_MAX - 1) | ||
41 | |||
42 | enum { | ||
43 | CTRL_ATTR_UNSPEC, | ||
44 | CTRL_ATTR_FAMILY_ID, | ||
45 | CTRL_ATTR_FAMILY_NAME, | ||
46 | __CTRL_ATTR_MAX, | ||
47 | }; | ||
48 | |||
49 | #define CTRL_ATTR_MAX (__CTRL_ATTR_MAX - 1) | ||
50 | |||
51 | #endif /* __LINUX_GENERIC_NETLINK_H */ | ||
diff --git a/include/net/genetlink.h b/include/net/genetlink.h new file mode 100644 index 000000000000..52d8b1a73d52 --- /dev/null +++ b/include/net/genetlink.h | |||
@@ -0,0 +1,154 @@ | |||
1 | #ifndef __NET_GENERIC_NETLINK_H | ||
2 | #define __NET_GENERIC_NETLINK_H | ||
3 | |||
4 | #include <linux/genetlink.h> | ||
5 | #include <net/netlink.h> | ||
6 | |||
7 | /** | ||
8 | * struct genl_family - generic netlink family | ||
9 | * @id: protocol family idenfitier | ||
10 | * @hdrsize: length of user specific header in bytes | ||
11 | * @name: name of family | ||
12 | * @version: protocol version | ||
13 | * @maxattr: maximum number of attributes supported | ||
14 | * @attrbuf: buffer to store parsed attributes | ||
15 | * @ops_list: list of all assigned operations | ||
16 | * @family_list: family list | ||
17 | */ | ||
18 | struct genl_family | ||
19 | { | ||
20 | unsigned int id; | ||
21 | unsigned int hdrsize; | ||
22 | char name[GENL_NAMSIZ]; | ||
23 | unsigned int version; | ||
24 | unsigned int maxattr; | ||
25 | struct module * owner; | ||
26 | struct nlattr ** attrbuf; /* private */ | ||
27 | struct list_head ops_list; /* private */ | ||
28 | struct list_head family_list; /* private */ | ||
29 | }; | ||
30 | |||
31 | #define GENL_ADMIN_PERM 0x01 | ||
32 | |||
33 | /** | ||
34 | * struct genl_info - receiving information | ||
35 | * @snd_seq: sending sequence number | ||
36 | * @snd_pid: netlink pid of sender | ||
37 | * @nlhdr: netlink message header | ||
38 | * @genlhdr: generic netlink message header | ||
39 | * @userhdr: user specific header | ||
40 | * @attrs: netlink attributes | ||
41 | */ | ||
42 | struct genl_info | ||
43 | { | ||
44 | u32 snd_seq; | ||
45 | u32 snd_pid; | ||
46 | struct nlmsghdr * nlhdr; | ||
47 | struct genlmsghdr * genlhdr; | ||
48 | void * userhdr; | ||
49 | struct nlattr ** attrs; | ||
50 | }; | ||
51 | |||
52 | /** | ||
53 | * struct genl_ops - generic netlink operations | ||
54 | * @cmd: command identifier | ||
55 | * @flags: flags | ||
56 | * @policy: attribute validation policy | ||
57 | * @doit: standard command callback | ||
58 | * @dumpit: callback for dumpers | ||
59 | * @ops_list: operations list | ||
60 | */ | ||
61 | struct genl_ops | ||
62 | { | ||
63 | unsigned int cmd; | ||
64 | unsigned int flags; | ||
65 | struct nla_policy *policy; | ||
66 | int (*doit)(struct sk_buff *skb, | ||
67 | struct genl_info *info); | ||
68 | int (*dumpit)(struct sk_buff *skb, | ||
69 | struct netlink_callback *cb); | ||
70 | struct list_head ops_list; | ||
71 | }; | ||
72 | |||
73 | extern int genl_register_family(struct genl_family *family); | ||
74 | extern int genl_unregister_family(struct genl_family *family); | ||
75 | extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); | ||
76 | extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops); | ||
77 | |||
78 | extern struct sock *genl_sock; | ||
79 | |||
80 | /** | ||
81 | * genlmsg_put - Add generic netlink header to netlink message | ||
82 | * @skb: socket buffer holding the message | ||
83 | * @pid: netlink pid the message is addressed to | ||
84 | * @seq: sequence number (usually the one of the sender) | ||
85 | * @type: netlink message type | ||
86 | * @hdrlen: length of the user specific header | ||
87 | * @flags netlink message flags | ||
88 | * @cmd: generic netlink command | ||
89 | * @version: version | ||
90 | * | ||
91 | * Returns pointer to user specific header | ||
92 | */ | ||
93 | static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, | ||
94 | int type, int hdrlen, int flags, | ||
95 | u8 cmd, u8 version) | ||
96 | { | ||
97 | struct nlmsghdr *nlh; | ||
98 | struct genlmsghdr *hdr; | ||
99 | |||
100 | nlh = nlmsg_put(skb, pid, seq, type, GENL_HDRLEN + hdrlen, flags); | ||
101 | if (nlh == NULL) | ||
102 | return NULL; | ||
103 | |||
104 | hdr = nlmsg_data(nlh); | ||
105 | hdr->cmd = cmd; | ||
106 | hdr->version = version; | ||
107 | hdr->reserved = 0; | ||
108 | |||
109 | return (char *) hdr + GENL_HDRLEN; | ||
110 | } | ||
111 | |||
112 | /** | ||
113 | * genlmsg_end - Finalize a generic netlink message | ||
114 | * @skb: socket buffer the message is stored in | ||
115 | * @hdr: user specific header | ||
116 | */ | ||
117 | static inline int genlmsg_end(struct sk_buff *skb, void *hdr) | ||
118 | { | ||
119 | return nlmsg_end(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | ||
120 | } | ||
121 | |||
122 | /** | ||
123 | * genlmsg_cancel - Cancel construction of a generic netlink message | ||
124 | * @skb: socket buffer the message is stored in | ||
125 | * @hdr: generic netlink message header | ||
126 | */ | ||
127 | static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr) | ||
128 | { | ||
129 | return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); | ||
130 | } | ||
131 | |||
132 | /** | ||
133 | * genlmsg_multicast - multicast a netlink message | ||
134 | * @skb: netlink message as socket buffer | ||
135 | * @pid: own netlink pid to avoid sending to yourself | ||
136 | * @group: multicast group id | ||
137 | */ | ||
138 | static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid, | ||
139 | unsigned int group) | ||
140 | { | ||
141 | return nlmsg_multicast(genl_sock, skb, pid, group); | ||
142 | } | ||
143 | |||
144 | /** | ||
145 | * genlmsg_unicast - unicast a netlink message | ||
146 | * @skb: netlink message as socket buffer | ||
147 | * @pid: netlink pid of the destination socket | ||
148 | */ | ||
149 | static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid) | ||
150 | { | ||
151 | return nlmsg_unicast(genl_sock, skb, pid); | ||
152 | } | ||
153 | |||
154 | #endif /* __NET_GENERIC_NETLINK_H */ | ||
diff --git a/net/netlink/Makefile b/net/netlink/Makefile index 68179015bd39..e3589c2de49e 100644 --- a/net/netlink/Makefile +++ b/net/netlink/Makefile | |||
@@ -2,4 +2,4 @@ | |||
2 | # Makefile for the netlink driver. | 2 | # Makefile for the netlink driver. |
3 | # | 3 | # |
4 | 4 | ||
5 | obj-y := af_netlink.o attr.o | 5 | obj-y := af_netlink.o attr.o genetlink.o |
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c new file mode 100644 index 000000000000..287cfcc56951 --- /dev/null +++ b/net/netlink/genetlink.c | |||
@@ -0,0 +1,579 @@ | |||
1 | /* | ||
2 | * NETLINK Generic Netlink Family | ||
3 | * | ||
4 | * Authors: Jamal Hadi Salim | ||
5 | * Thomas Graf <tgraf@suug.ch> | ||
6 | */ | ||
7 | |||
8 | #include <linux/config.h> | ||
9 | #include <linux/module.h> | ||
10 | #include <linux/kernel.h> | ||
11 | #include <linux/errno.h> | ||
12 | #include <linux/types.h> | ||
13 | #include <linux/socket.h> | ||
14 | #include <linux/string.h> | ||
15 | #include <linux/skbuff.h> | ||
16 | #include <net/sock.h> | ||
17 | #include <net/genetlink.h> | ||
18 | |||
19 | struct sock *genl_sock = NULL; | ||
20 | |||
21 | static DECLARE_MUTEX(genl_sem); /* serialization of message processing */ | ||
22 | |||
23 | static void genl_lock(void) | ||
24 | { | ||
25 | down(&genl_sem); | ||
26 | } | ||
27 | |||
28 | static int genl_trylock(void) | ||
29 | { | ||
30 | return down_trylock(&genl_sem); | ||
31 | } | ||
32 | |||
33 | static void genl_unlock(void) | ||
34 | { | ||
35 | up(&genl_sem); | ||
36 | |||
37 | if (genl_sock && genl_sock->sk_receive_queue.qlen) | ||
38 | genl_sock->sk_data_ready(genl_sock, 0); | ||
39 | } | ||
40 | |||
41 | #define GENL_FAM_TAB_SIZE 16 | ||
42 | #define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1) | ||
43 | |||
44 | static struct list_head family_ht[GENL_FAM_TAB_SIZE]; | ||
45 | |||
46 | static int genl_ctrl_event(int event, void *data); | ||
47 | |||
48 | static inline unsigned int genl_family_hash(unsigned int id) | ||
49 | { | ||
50 | return id & GENL_FAM_TAB_MASK; | ||
51 | } | ||
52 | |||
53 | static inline struct list_head *genl_family_chain(unsigned int id) | ||
54 | { | ||
55 | return &family_ht[genl_family_hash(id)]; | ||
56 | } | ||
57 | |||
58 | static struct genl_family *genl_family_find_byid(unsigned int id) | ||
59 | { | ||
60 | struct genl_family *f; | ||
61 | |||
62 | list_for_each_entry(f, genl_family_chain(id), family_list) | ||
63 | if (f->id == id) | ||
64 | return f; | ||
65 | |||
66 | return NULL; | ||
67 | } | ||
68 | |||
69 | static struct genl_family *genl_family_find_byname(char *name) | ||
70 | { | ||
71 | struct genl_family *f; | ||
72 | int i; | ||
73 | |||
74 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | ||
75 | list_for_each_entry(f, genl_family_chain(i), family_list) | ||
76 | if (strcmp(f->name, name) == 0) | ||
77 | return f; | ||
78 | |||
79 | return NULL; | ||
80 | } | ||
81 | |||
82 | static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) | ||
83 | { | ||
84 | struct genl_ops *ops; | ||
85 | |||
86 | list_for_each_entry(ops, &family->ops_list, ops_list) | ||
87 | if (ops->cmd == cmd) | ||
88 | return ops; | ||
89 | |||
90 | return NULL; | ||
91 | } | ||
92 | |||
93 | /* Of course we are going to have problems once we hit | ||
94 | * 2^16 alive types, but that can only happen by year 2K | ||
95 | */ | ||
96 | static inline u16 genl_generate_id(void) | ||
97 | { | ||
98 | static u16 id_gen_idx; | ||
99 | int overflowed = 0; | ||
100 | |||
101 | do { | ||
102 | if (id_gen_idx == 0) | ||
103 | id_gen_idx = GENL_MIN_ID; | ||
104 | |||
105 | if (++id_gen_idx > GENL_MAX_ID) { | ||
106 | if (!overflowed) { | ||
107 | overflowed = 1; | ||
108 | id_gen_idx = 0; | ||
109 | continue; | ||
110 | } else | ||
111 | return 0; | ||
112 | } | ||
113 | |||
114 | } while (genl_family_find_byid(id_gen_idx)); | ||
115 | |||
116 | return id_gen_idx; | ||
117 | } | ||
118 | |||
119 | /** | ||
120 | * genl_register_ops - register generic netlink operations | ||
121 | * @family: generic netlink family | ||
122 | * @ops: operations to be registered | ||
123 | * | ||
124 | * Registers the specified operations and assigns them to the specified | ||
125 | * family. Either a doit or dumpit callback must be specified or the | ||
126 | * operation will fail. Only one operation structure per command | ||
127 | * identifier may be registered. | ||
128 | * | ||
129 | * See include/net/genetlink.h for more documenation on the operations | ||
130 | * structure. | ||
131 | * | ||
132 | * Returns 0 on success or a negative error code. | ||
133 | */ | ||
134 | int genl_register_ops(struct genl_family *family, struct genl_ops *ops) | ||
135 | { | ||
136 | int err = -EINVAL; | ||
137 | |||
138 | if (ops->dumpit == NULL && ops->doit == NULL) | ||
139 | goto errout; | ||
140 | |||
141 | if (genl_get_cmd(ops->cmd, family)) { | ||
142 | err = -EEXIST; | ||
143 | goto errout; | ||
144 | } | ||
145 | |||
146 | genl_lock(); | ||
147 | list_add_tail(&ops->ops_list, &family->ops_list); | ||
148 | genl_unlock(); | ||
149 | |||
150 | genl_ctrl_event(CTRL_CMD_NEWOPS, ops); | ||
151 | err = 0; | ||
152 | errout: | ||
153 | return err; | ||
154 | } | ||
155 | |||
156 | /** | ||
157 | * genl_unregister_ops - unregister generic netlink operations | ||
158 | * @family: generic netlink family | ||
159 | * @ops: operations to be unregistered | ||
160 | * | ||
161 | * Unregisters the specified operations and unassigns them from the | ||
162 | * specified family. The operation blocks until the current message | ||
163 | * processing has finished and doesn't start again until the | ||
164 | * unregister process has finished. | ||
165 | * | ||
166 | * Note: It is not necessary to unregister all operations before | ||
167 | * unregistering the family, unregistering the family will cause | ||
168 | * all assigned operations to be unregistered automatically. | ||
169 | * | ||
170 | * Returns 0 on success or a negative error code. | ||
171 | */ | ||
172 | int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops) | ||
173 | { | ||
174 | struct genl_ops *rc; | ||
175 | |||
176 | genl_lock(); | ||
177 | list_for_each_entry(rc, &family->ops_list, ops_list) { | ||
178 | if (rc == ops) { | ||
179 | list_del(&ops->ops_list); | ||
180 | genl_unlock(); | ||
181 | genl_ctrl_event(CTRL_CMD_DELOPS, ops); | ||
182 | return 0; | ||
183 | } | ||
184 | } | ||
185 | genl_unlock(); | ||
186 | |||
187 | return -ENOENT; | ||
188 | } | ||
189 | |||
190 | /** | ||
191 | * genl_register_family - register a generic netlink family | ||
192 | * @family: generic netlink family | ||
193 | * | ||
194 | * Registers the specified family after validating it first. Only one | ||
195 | * family may be registered with the same family name or identifier. | ||
196 | * The family id may equal GENL_ID_GENERATE causing an unique id to | ||
197 | * be automatically generated and assigned. | ||
198 | * | ||
199 | * Return 0 on success or a negative error code. | ||
200 | */ | ||
201 | int genl_register_family(struct genl_family *family) | ||
202 | { | ||
203 | int err = -EINVAL; | ||
204 | |||
205 | if (family->id && family->id < GENL_MIN_ID) | ||
206 | goto errout; | ||
207 | |||
208 | if (family->id > GENL_MAX_ID) | ||
209 | goto errout; | ||
210 | |||
211 | INIT_LIST_HEAD(&family->ops_list); | ||
212 | |||
213 | genl_lock(); | ||
214 | |||
215 | if (genl_family_find_byname(family->name)) { | ||
216 | err = -EEXIST; | ||
217 | goto errout_locked; | ||
218 | } | ||
219 | |||
220 | if (genl_family_find_byid(family->id)) { | ||
221 | err = -EEXIST; | ||
222 | goto errout_locked; | ||
223 | } | ||
224 | |||
225 | if (!try_module_get(family->owner)) { | ||
226 | err = -EBUSY; | ||
227 | goto errout_locked; | ||
228 | } | ||
229 | |||
230 | if (family->id == GENL_ID_GENERATE) { | ||
231 | u16 newid = genl_generate_id(); | ||
232 | |||
233 | if (!newid) { | ||
234 | err = -ENOMEM; | ||
235 | goto errout_locked; | ||
236 | } | ||
237 | |||
238 | family->id = newid; | ||
239 | } | ||
240 | |||
241 | if (family->maxattr) { | ||
242 | family->attrbuf = kmalloc((family->maxattr+1) * | ||
243 | sizeof(struct nlattr *), GFP_KERNEL); | ||
244 | if (family->attrbuf == NULL) { | ||
245 | err = -ENOMEM; | ||
246 | goto errout; | ||
247 | } | ||
248 | } else | ||
249 | family->attrbuf = NULL; | ||
250 | |||
251 | list_add_tail(&family->family_list, genl_family_chain(family->id)); | ||
252 | genl_unlock(); | ||
253 | |||
254 | genl_ctrl_event(CTRL_CMD_NEWFAMILY, family); | ||
255 | |||
256 | return 0; | ||
257 | |||
258 | errout_locked: | ||
259 | genl_unlock(); | ||
260 | errout: | ||
261 | return err; | ||
262 | } | ||
263 | |||
264 | /** | ||
265 | * genl_unregister_family - unregister generic netlink family | ||
266 | * @family: generic netlink family | ||
267 | * | ||
268 | * Unregisters the specified family. | ||
269 | * | ||
270 | * Returns 0 on success or a negative error code. | ||
271 | */ | ||
272 | int genl_unregister_family(struct genl_family *family) | ||
273 | { | ||
274 | struct genl_family *rc; | ||
275 | |||
276 | genl_lock(); | ||
277 | |||
278 | list_for_each_entry(rc, genl_family_chain(family->id), family_list) { | ||
279 | if (family->id != rc->id || strcmp(rc->name, family->name)) | ||
280 | continue; | ||
281 | |||
282 | list_del(&rc->family_list); | ||
283 | INIT_LIST_HEAD(&family->ops_list); | ||
284 | genl_unlock(); | ||
285 | |||
286 | module_put(family->owner); | ||
287 | kfree(family->attrbuf); | ||
288 | genl_ctrl_event(CTRL_CMD_DELFAMILY, family); | ||
289 | return 0; | ||
290 | } | ||
291 | |||
292 | genl_unlock(); | ||
293 | |||
294 | return -ENOENT; | ||
295 | } | ||
296 | |||
297 | static inline int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, | ||
298 | int *errp) | ||
299 | { | ||
300 | struct genl_ops *ops; | ||
301 | struct genl_family *family; | ||
302 | struct genl_info info; | ||
303 | struct genlmsghdr *hdr = nlmsg_data(nlh); | ||
304 | int hdrlen, err = -EINVAL; | ||
305 | |||
306 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | ||
307 | goto ignore; | ||
308 | |||
309 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | ||
310 | goto ignore; | ||
311 | |||
312 | family = genl_family_find_byid(nlh->nlmsg_type); | ||
313 | if (family == NULL) { | ||
314 | err = -ENOENT; | ||
315 | goto errout; | ||
316 | } | ||
317 | |||
318 | hdrlen = GENL_HDRLEN + family->hdrsize; | ||
319 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | ||
320 | goto errout; | ||
321 | |||
322 | ops = genl_get_cmd(hdr->cmd, family); | ||
323 | if (ops == NULL) { | ||
324 | err = -EOPNOTSUPP; | ||
325 | goto errout; | ||
326 | } | ||
327 | |||
328 | if ((ops->flags & GENL_ADMIN_PERM) && security_netlink_recv(skb)) { | ||
329 | err = -EPERM; | ||
330 | goto errout; | ||
331 | } | ||
332 | |||
333 | if (nlh->nlmsg_flags & NLM_F_DUMP) { | ||
334 | if (ops->dumpit == NULL) { | ||
335 | err = -EOPNOTSUPP; | ||
336 | goto errout; | ||
337 | } | ||
338 | |||
339 | *errp = err = netlink_dump_start(genl_sock, skb, nlh, | ||
340 | ops->dumpit, NULL); | ||
341 | if (err == 0) | ||
342 | skb_pull(skb, min(NLMSG_ALIGN(nlh->nlmsg_len), | ||
343 | skb->len)); | ||
344 | return -1; | ||
345 | } | ||
346 | |||
347 | if (ops->doit == NULL) { | ||
348 | err = -EOPNOTSUPP; | ||
349 | goto errout; | ||
350 | } | ||
351 | |||
352 | if (family->attrbuf) { | ||
353 | err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr, | ||
354 | ops->policy); | ||
355 | if (err < 0) | ||
356 | goto errout; | ||
357 | } | ||
358 | |||
359 | info.snd_seq = nlh->nlmsg_seq; | ||
360 | info.snd_pid = NETLINK_CB(skb).pid; | ||
361 | info.nlhdr = nlh; | ||
362 | info.genlhdr = nlmsg_data(nlh); | ||
363 | info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; | ||
364 | info.attrs = family->attrbuf; | ||
365 | |||
366 | *errp = err = ops->doit(skb, &info); | ||
367 | return err; | ||
368 | |||
369 | ignore: | ||
370 | return 0; | ||
371 | |||
372 | errout: | ||
373 | *errp = err; | ||
374 | return -1; | ||
375 | } | ||
376 | |||
377 | static void genl_rcv(struct sock *sk, int len) | ||
378 | { | ||
379 | unsigned int qlen = 0; | ||
380 | |||
381 | do { | ||
382 | if (genl_trylock()) | ||
383 | return; | ||
384 | netlink_run_queue(sk, &qlen, &genl_rcv_msg); | ||
385 | genl_unlock(); | ||
386 | } while (qlen && genl_sock && genl_sock->sk_receive_queue.qlen); | ||
387 | } | ||
388 | |||
389 | /************************************************************************** | ||
390 | * Controller | ||
391 | **************************************************************************/ | ||
392 | |||
393 | static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq, | ||
394 | u32 flags, struct sk_buff *skb, u8 cmd) | ||
395 | { | ||
396 | void *hdr; | ||
397 | |||
398 | hdr = genlmsg_put(skb, pid, seq, GENL_ID_CTRL, 0, flags, cmd, | ||
399 | family->version); | ||
400 | if (hdr == NULL) | ||
401 | return -1; | ||
402 | |||
403 | NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name); | ||
404 | NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id); | ||
405 | |||
406 | return genlmsg_end(skb, hdr); | ||
407 | |||
408 | nla_put_failure: | ||
409 | return genlmsg_cancel(skb, hdr); | ||
410 | } | ||
411 | |||
412 | static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) | ||
413 | { | ||
414 | |||
415 | int i, n = 0; | ||
416 | struct genl_family *rt; | ||
417 | int chains_to_skip = cb->args[0]; | ||
418 | int fams_to_skip = cb->args[1]; | ||
419 | |||
420 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) { | ||
421 | if (i < chains_to_skip) | ||
422 | continue; | ||
423 | n = 0; | ||
424 | list_for_each_entry(rt, genl_family_chain(i), family_list) { | ||
425 | if (++n < fams_to_skip) | ||
426 | continue; | ||
427 | if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid, | ||
428 | cb->nlh->nlmsg_seq, NLM_F_MULTI, | ||
429 | skb, CTRL_CMD_NEWFAMILY) < 0) | ||
430 | goto errout; | ||
431 | } | ||
432 | |||
433 | fams_to_skip = 0; | ||
434 | } | ||
435 | |||
436 | errout: | ||
437 | cb->args[0] = i; | ||
438 | cb->args[1] = n; | ||
439 | |||
440 | return skb->len; | ||
441 | } | ||
442 | |||
443 | static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid, | ||
444 | int seq, int cmd) | ||
445 | { | ||
446 | struct sk_buff *skb; | ||
447 | int err; | ||
448 | |||
449 | skb = nlmsg_new(NLMSG_GOODSIZE); | ||
450 | if (skb == NULL) | ||
451 | return ERR_PTR(-ENOBUFS); | ||
452 | |||
453 | err = ctrl_fill_info(family, pid, seq, 0, skb, cmd); | ||
454 | if (err < 0) { | ||
455 | nlmsg_free(skb); | ||
456 | return ERR_PTR(err); | ||
457 | } | ||
458 | |||
459 | return skb; | ||
460 | } | ||
461 | |||
462 | static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = { | ||
463 | [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, | ||
464 | [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING }, | ||
465 | }; | ||
466 | |||
467 | static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) | ||
468 | { | ||
469 | struct sk_buff *msg; | ||
470 | struct genl_family *res = NULL; | ||
471 | int err = -EINVAL; | ||
472 | |||
473 | if (info->attrs[CTRL_ATTR_FAMILY_ID]) { | ||
474 | u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]); | ||
475 | res = genl_family_find_byid(id); | ||
476 | } | ||
477 | |||
478 | if (info->attrs[CTRL_ATTR_FAMILY_NAME]) { | ||
479 | char name[GENL_NAMSIZ]; | ||
480 | |||
481 | if (nla_strlcpy(name, info->attrs[CTRL_ATTR_FAMILY_NAME], | ||
482 | GENL_NAMSIZ) >= GENL_NAMSIZ) | ||
483 | goto errout; | ||
484 | |||
485 | res = genl_family_find_byname(name); | ||
486 | } | ||
487 | |||
488 | if (res == NULL) { | ||
489 | err = -ENOENT; | ||
490 | goto errout; | ||
491 | } | ||
492 | |||
493 | msg = ctrl_build_msg(res, info->snd_pid, info->snd_seq, | ||
494 | CTRL_CMD_NEWFAMILY); | ||
495 | if (IS_ERR(msg)) { | ||
496 | err = PTR_ERR(msg); | ||
497 | goto errout; | ||
498 | } | ||
499 | |||
500 | err = genlmsg_unicast(msg, info->snd_pid); | ||
501 | errout: | ||
502 | return err; | ||
503 | } | ||
504 | |||
505 | static int genl_ctrl_event(int event, void *data) | ||
506 | { | ||
507 | struct sk_buff *msg; | ||
508 | |||
509 | if (genl_sock == NULL) | ||
510 | return 0; | ||
511 | |||
512 | switch (event) { | ||
513 | case CTRL_CMD_NEWFAMILY: | ||
514 | case CTRL_CMD_DELFAMILY: | ||
515 | msg = ctrl_build_msg(data, 0, 0, event); | ||
516 | if (IS_ERR(msg)) | ||
517 | return PTR_ERR(msg); | ||
518 | |||
519 | genlmsg_multicast(msg, 0, GENL_ID_CTRL); | ||
520 | break; | ||
521 | } | ||
522 | |||
523 | return 0; | ||
524 | } | ||
525 | |||
526 | static struct genl_ops genl_ctrl_ops = { | ||
527 | .cmd = CTRL_CMD_GETFAMILY, | ||
528 | .doit = ctrl_getfamily, | ||
529 | .dumpit = ctrl_dumpfamily, | ||
530 | .policy = ctrl_policy, | ||
531 | }; | ||
532 | |||
533 | static struct genl_family genl_ctrl = { | ||
534 | .id = GENL_ID_CTRL, | ||
535 | .name = "nlctrl", | ||
536 | .version = 0x1, | ||
537 | .maxattr = CTRL_ATTR_MAX, | ||
538 | .owner = THIS_MODULE, | ||
539 | }; | ||
540 | |||
541 | static int __init genl_init(void) | ||
542 | { | ||
543 | int i, err; | ||
544 | |||
545 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | ||
546 | INIT_LIST_HEAD(&family_ht[i]); | ||
547 | |||
548 | err = genl_register_family(&genl_ctrl); | ||
549 | if (err < 0) | ||
550 | goto errout; | ||
551 | |||
552 | err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops); | ||
553 | if (err < 0) | ||
554 | goto errout_register; | ||
555 | |||
556 | netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV); | ||
557 | genl_sock = netlink_kernel_create(NETLINK_GENERIC, GENL_MAX_ID, | ||
558 | genl_rcv, THIS_MODULE); | ||
559 | if (genl_sock == NULL) { | ||
560 | panic("GENL: Cannot initialize generic netlink\n"); | ||
561 | return -ENOMEM; | ||
562 | } | ||
563 | |||
564 | return 0; | ||
565 | |||
566 | errout_register: | ||
567 | genl_unregister_family(&genl_ctrl); | ||
568 | errout: | ||
569 | panic("GENL: Cannot register controller: %d\n", err); | ||
570 | return err; | ||
571 | } | ||
572 | |||
573 | subsys_initcall(genl_init); | ||
574 | |||
575 | EXPORT_SYMBOL(genl_sock); | ||
576 | EXPORT_SYMBOL(genl_register_ops); | ||
577 | EXPORT_SYMBOL(genl_unregister_ops); | ||
578 | EXPORT_SYMBOL(genl_register_family); | ||
579 | EXPORT_SYMBOL(genl_unregister_family); | ||