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Commit | Line | Data |
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482a8524 TG |
1 | /* |
2 | * NETLINK Generic Netlink Family | |
3 | * | |
4 | * Authors: Jamal Hadi Salim | |
5 | * Thomas Graf <tgraf@suug.ch> | |
2dbba6f7 | 6 | * Johannes Berg <johannes@sipsolutions.net> |
482a8524 TG |
7 | */ |
8 | ||
482a8524 TG |
9 | #include <linux/module.h> |
10 | #include <linux/kernel.h> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
482a8524 TG |
12 | #include <linux/errno.h> |
13 | #include <linux/types.h> | |
14 | #include <linux/socket.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/skbuff.h> | |
14cc3e2b | 17 | #include <linux/mutex.h> |
2dbba6f7 | 18 | #include <linux/bitmap.h> |
482a8524 TG |
19 | #include <net/sock.h> |
20 | #include <net/genetlink.h> | |
21 | ||
14cc3e2b | 22 | static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */ |
482a8524 | 23 | |
f408e0ce | 24 | void genl_lock(void) |
482a8524 | 25 | { |
14cc3e2b | 26 | mutex_lock(&genl_mutex); |
482a8524 | 27 | } |
f408e0ce | 28 | EXPORT_SYMBOL(genl_lock); |
482a8524 | 29 | |
f408e0ce | 30 | void genl_unlock(void) |
482a8524 | 31 | { |
14cc3e2b | 32 | mutex_unlock(&genl_mutex); |
482a8524 | 33 | } |
f408e0ce | 34 | EXPORT_SYMBOL(genl_unlock); |
482a8524 TG |
35 | |
36 | #define GENL_FAM_TAB_SIZE 16 | |
37 | #define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1) | |
38 | ||
39 | static struct list_head family_ht[GENL_FAM_TAB_SIZE]; | |
2dbba6f7 JB |
40 | /* |
41 | * Bitmap of multicast groups that are currently in use. | |
42 | * | |
43 | * To avoid an allocation at boot of just one unsigned long, | |
44 | * declare it global instead. | |
45 | * Bit 0 is marked as already used since group 0 is invalid. | |
46 | */ | |
47 | static unsigned long mc_group_start = 0x1; | |
48 | static unsigned long *mc_groups = &mc_group_start; | |
49 | static unsigned long mc_groups_longs = 1; | |
482a8524 TG |
50 | |
51 | static int genl_ctrl_event(int event, void *data); | |
52 | ||
53 | static inline unsigned int genl_family_hash(unsigned int id) | |
54 | { | |
55 | return id & GENL_FAM_TAB_MASK; | |
56 | } | |
57 | ||
58 | static inline struct list_head *genl_family_chain(unsigned int id) | |
59 | { | |
60 | return &family_ht[genl_family_hash(id)]; | |
61 | } | |
62 | ||
63 | static struct genl_family *genl_family_find_byid(unsigned int id) | |
64 | { | |
65 | struct genl_family *f; | |
66 | ||
67 | list_for_each_entry(f, genl_family_chain(id), family_list) | |
68 | if (f->id == id) | |
69 | return f; | |
70 | ||
71 | return NULL; | |
72 | } | |
73 | ||
74 | static struct genl_family *genl_family_find_byname(char *name) | |
75 | { | |
76 | struct genl_family *f; | |
77 | int i; | |
78 | ||
79 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | |
80 | list_for_each_entry(f, genl_family_chain(i), family_list) | |
81 | if (strcmp(f->name, name) == 0) | |
82 | return f; | |
83 | ||
84 | return NULL; | |
85 | } | |
86 | ||
87 | static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) | |
88 | { | |
89 | struct genl_ops *ops; | |
90 | ||
91 | list_for_each_entry(ops, &family->ops_list, ops_list) | |
92 | if (ops->cmd == cmd) | |
93 | return ops; | |
94 | ||
95 | return NULL; | |
96 | } | |
97 | ||
98 | /* Of course we are going to have problems once we hit | |
99 | * 2^16 alive types, but that can only happen by year 2K | |
100 | */ | |
101 | static inline u16 genl_generate_id(void) | |
102 | { | |
988ade6b KK |
103 | static u16 id_gen_idx = GENL_MIN_ID; |
104 | int i; | |
482a8524 | 105 | |
988ade6b KK |
106 | for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) { |
107 | if (!genl_family_find_byid(id_gen_idx)) | |
108 | return id_gen_idx; | |
109 | if (++id_gen_idx > GENL_MAX_ID) | |
482a8524 | 110 | id_gen_idx = GENL_MIN_ID; |
988ade6b | 111 | } |
482a8524 | 112 | |
988ade6b | 113 | return 0; |
482a8524 TG |
114 | } |
115 | ||
2dbba6f7 JB |
116 | static struct genl_multicast_group notify_grp; |
117 | ||
118 | /** | |
119 | * genl_register_mc_group - register a multicast group | |
120 | * | |
121 | * Registers the specified multicast group and notifies userspace | |
122 | * about the new group. | |
123 | * | |
124 | * Returns 0 on success or a negative error code. | |
125 | * | |
126 | * @family: The generic netlink family the group shall be registered for. | |
127 | * @grp: The group to register, must have a name. | |
128 | */ | |
129 | int genl_register_mc_group(struct genl_family *family, | |
130 | struct genl_multicast_group *grp) | |
131 | { | |
132 | int id; | |
133 | unsigned long *new_groups; | |
b1f57195 | 134 | int err = 0; |
2dbba6f7 JB |
135 | |
136 | BUG_ON(grp->name[0] == '\0'); | |
137 | ||
138 | genl_lock(); | |
139 | ||
140 | /* special-case our own group */ | |
141 | if (grp == ¬ify_grp) | |
142 | id = GENL_ID_CTRL; | |
143 | else | |
144 | id = find_first_zero_bit(mc_groups, | |
145 | mc_groups_longs * BITS_PER_LONG); | |
146 | ||
147 | ||
148 | if (id >= mc_groups_longs * BITS_PER_LONG) { | |
149 | size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long); | |
150 | ||
151 | if (mc_groups == &mc_group_start) { | |
152 | new_groups = kzalloc(nlen, GFP_KERNEL); | |
153 | if (!new_groups) { | |
154 | err = -ENOMEM; | |
155 | goto out; | |
156 | } | |
157 | mc_groups = new_groups; | |
158 | *mc_groups = mc_group_start; | |
159 | } else { | |
160 | new_groups = krealloc(mc_groups, nlen, GFP_KERNEL); | |
161 | if (!new_groups) { | |
162 | err = -ENOMEM; | |
163 | goto out; | |
164 | } | |
165 | mc_groups = new_groups; | |
166 | mc_groups[mc_groups_longs] = 0; | |
167 | } | |
168 | mc_groups_longs++; | |
169 | } | |
170 | ||
134e6375 JB |
171 | if (family->netnsok) { |
172 | struct net *net; | |
173 | ||
d136f1bd | 174 | netlink_table_grab(); |
134e6375 JB |
175 | rcu_read_lock(); |
176 | for_each_net_rcu(net) { | |
d136f1bd | 177 | err = __netlink_change_ngroups(net->genl_sock, |
134e6375 JB |
178 | mc_groups_longs * BITS_PER_LONG); |
179 | if (err) { | |
180 | /* | |
181 | * No need to roll back, can only fail if | |
182 | * memory allocation fails and then the | |
183 | * number of _possible_ groups has been | |
184 | * increased on some sockets which is ok. | |
185 | */ | |
186 | rcu_read_unlock(); | |
d136f1bd | 187 | netlink_table_ungrab(); |
134e6375 JB |
188 | goto out; |
189 | } | |
190 | } | |
191 | rcu_read_unlock(); | |
d136f1bd | 192 | netlink_table_ungrab(); |
134e6375 JB |
193 | } else { |
194 | err = netlink_change_ngroups(init_net.genl_sock, | |
195 | mc_groups_longs * BITS_PER_LONG); | |
196 | if (err) | |
197 | goto out; | |
198 | } | |
2dbba6f7 JB |
199 | |
200 | grp->id = id; | |
201 | set_bit(id, mc_groups); | |
202 | list_add_tail(&grp->list, &family->mcast_groups); | |
203 | grp->family = family; | |
204 | ||
205 | genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp); | |
206 | out: | |
207 | genl_unlock(); | |
79d310d0 | 208 | return err; |
2dbba6f7 JB |
209 | } |
210 | EXPORT_SYMBOL(genl_register_mc_group); | |
211 | ||
79dc4386 TG |
212 | static void __genl_unregister_mc_group(struct genl_family *family, |
213 | struct genl_multicast_group *grp) | |
214 | { | |
134e6375 | 215 | struct net *net; |
79dc4386 | 216 | BUG_ON(grp->family != family); |
134e6375 | 217 | |
b8273570 | 218 | netlink_table_grab(); |
134e6375 JB |
219 | rcu_read_lock(); |
220 | for_each_net_rcu(net) | |
b8273570 | 221 | __netlink_clear_multicast_users(net->genl_sock, grp->id); |
134e6375 | 222 | rcu_read_unlock(); |
b8273570 | 223 | netlink_table_ungrab(); |
134e6375 | 224 | |
79dc4386 TG |
225 | clear_bit(grp->id, mc_groups); |
226 | list_del(&grp->list); | |
227 | genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp); | |
228 | grp->id = 0; | |
229 | grp->family = NULL; | |
230 | } | |
231 | ||
2dbba6f7 JB |
232 | /** |
233 | * genl_unregister_mc_group - unregister a multicast group | |
234 | * | |
235 | * Unregisters the specified multicast group and notifies userspace | |
236 | * about it. All current listeners on the group are removed. | |
237 | * | |
238 | * Note: It is not necessary to unregister all multicast groups before | |
239 | * unregistering the family, unregistering the family will cause | |
240 | * all assigned multicast groups to be unregistered automatically. | |
241 | * | |
242 | * @family: Generic netlink family the group belongs to. | |
243 | * @grp: The group to unregister, must have been registered successfully | |
244 | * previously. | |
245 | */ | |
246 | void genl_unregister_mc_group(struct genl_family *family, | |
247 | struct genl_multicast_group *grp) | |
248 | { | |
2dbba6f7 | 249 | genl_lock(); |
79dc4386 | 250 | __genl_unregister_mc_group(family, grp); |
2dbba6f7 JB |
251 | genl_unlock(); |
252 | } | |
3efb40c2 | 253 | EXPORT_SYMBOL(genl_unregister_mc_group); |
2dbba6f7 JB |
254 | |
255 | static void genl_unregister_mc_groups(struct genl_family *family) | |
256 | { | |
257 | struct genl_multicast_group *grp, *tmp; | |
258 | ||
259 | list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list) | |
79dc4386 | 260 | __genl_unregister_mc_group(family, grp); |
2dbba6f7 JB |
261 | } |
262 | ||
482a8524 TG |
263 | /** |
264 | * genl_register_ops - register generic netlink operations | |
265 | * @family: generic netlink family | |
266 | * @ops: operations to be registered | |
267 | * | |
268 | * Registers the specified operations and assigns them to the specified | |
269 | * family. Either a doit or dumpit callback must be specified or the | |
270 | * operation will fail. Only one operation structure per command | |
271 | * identifier may be registered. | |
272 | * | |
273 | * See include/net/genetlink.h for more documenation on the operations | |
274 | * structure. | |
275 | * | |
276 | * Returns 0 on success or a negative error code. | |
277 | */ | |
278 | int genl_register_ops(struct genl_family *family, struct genl_ops *ops) | |
279 | { | |
280 | int err = -EINVAL; | |
281 | ||
282 | if (ops->dumpit == NULL && ops->doit == NULL) | |
283 | goto errout; | |
284 | ||
285 | if (genl_get_cmd(ops->cmd, family)) { | |
286 | err = -EEXIST; | |
287 | goto errout; | |
288 | } | |
289 | ||
334c29a6 | 290 | if (ops->dumpit) |
334c29a6 | 291 | ops->flags |= GENL_CMD_CAP_DUMP; |
48d4ed7a JHS |
292 | if (ops->doit) |
293 | ops->flags |= GENL_CMD_CAP_DO; | |
334c29a6 JHS |
294 | if (ops->policy) |
295 | ops->flags |= GENL_CMD_CAP_HASPOL; | |
296 | ||
482a8524 TG |
297 | genl_lock(); |
298 | list_add_tail(&ops->ops_list, &family->ops_list); | |
299 | genl_unlock(); | |
300 | ||
301 | genl_ctrl_event(CTRL_CMD_NEWOPS, ops); | |
302 | err = 0; | |
303 | errout: | |
304 | return err; | |
305 | } | |
416c2f9c | 306 | EXPORT_SYMBOL(genl_register_ops); |
482a8524 TG |
307 | |
308 | /** | |
309 | * genl_unregister_ops - unregister generic netlink operations | |
310 | * @family: generic netlink family | |
311 | * @ops: operations to be unregistered | |
312 | * | |
313 | * Unregisters the specified operations and unassigns them from the | |
314 | * specified family. The operation blocks until the current message | |
315 | * processing has finished and doesn't start again until the | |
316 | * unregister process has finished. | |
317 | * | |
318 | * Note: It is not necessary to unregister all operations before | |
319 | * unregistering the family, unregistering the family will cause | |
320 | * all assigned operations to be unregistered automatically. | |
321 | * | |
322 | * Returns 0 on success or a negative error code. | |
323 | */ | |
324 | int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops) | |
325 | { | |
326 | struct genl_ops *rc; | |
327 | ||
328 | genl_lock(); | |
329 | list_for_each_entry(rc, &family->ops_list, ops_list) { | |
330 | if (rc == ops) { | |
331 | list_del(&ops->ops_list); | |
332 | genl_unlock(); | |
333 | genl_ctrl_event(CTRL_CMD_DELOPS, ops); | |
334 | return 0; | |
335 | } | |
336 | } | |
337 | genl_unlock(); | |
338 | ||
339 | return -ENOENT; | |
340 | } | |
416c2f9c | 341 | EXPORT_SYMBOL(genl_unregister_ops); |
482a8524 TG |
342 | |
343 | /** | |
344 | * genl_register_family - register a generic netlink family | |
345 | * @family: generic netlink family | |
346 | * | |
347 | * Registers the specified family after validating it first. Only one | |
348 | * family may be registered with the same family name or identifier. | |
349 | * The family id may equal GENL_ID_GENERATE causing an unique id to | |
350 | * be automatically generated and assigned. | |
351 | * | |
352 | * Return 0 on success or a negative error code. | |
353 | */ | |
354 | int genl_register_family(struct genl_family *family) | |
355 | { | |
356 | int err = -EINVAL; | |
357 | ||
358 | if (family->id && family->id < GENL_MIN_ID) | |
359 | goto errout; | |
360 | ||
361 | if (family->id > GENL_MAX_ID) | |
362 | goto errout; | |
363 | ||
364 | INIT_LIST_HEAD(&family->ops_list); | |
2dbba6f7 | 365 | INIT_LIST_HEAD(&family->mcast_groups); |
482a8524 TG |
366 | |
367 | genl_lock(); | |
368 | ||
369 | if (genl_family_find_byname(family->name)) { | |
370 | err = -EEXIST; | |
371 | goto errout_locked; | |
372 | } | |
373 | ||
482a8524 TG |
374 | if (family->id == GENL_ID_GENERATE) { |
375 | u16 newid = genl_generate_id(); | |
376 | ||
377 | if (!newid) { | |
378 | err = -ENOMEM; | |
379 | goto errout_locked; | |
380 | } | |
381 | ||
382 | family->id = newid; | |
93860b08 KK |
383 | } else if (genl_family_find_byid(family->id)) { |
384 | err = -EEXIST; | |
385 | goto errout_locked; | |
482a8524 TG |
386 | } |
387 | ||
388 | if (family->maxattr) { | |
389 | family->attrbuf = kmalloc((family->maxattr+1) * | |
390 | sizeof(struct nlattr *), GFP_KERNEL); | |
391 | if (family->attrbuf == NULL) { | |
392 | err = -ENOMEM; | |
e200bd80 | 393 | goto errout_locked; |
482a8524 TG |
394 | } |
395 | } else | |
396 | family->attrbuf = NULL; | |
397 | ||
398 | list_add_tail(&family->family_list, genl_family_chain(family->id)); | |
399 | genl_unlock(); | |
400 | ||
401 | genl_ctrl_event(CTRL_CMD_NEWFAMILY, family); | |
402 | ||
403 | return 0; | |
404 | ||
405 | errout_locked: | |
406 | genl_unlock(); | |
407 | errout: | |
408 | return err; | |
409 | } | |
416c2f9c | 410 | EXPORT_SYMBOL(genl_register_family); |
482a8524 | 411 | |
a7b11d73 MM |
412 | /** |
413 | * genl_register_family_with_ops - register a generic netlink family | |
414 | * @family: generic netlink family | |
415 | * @ops: operations to be registered | |
416 | * @n_ops: number of elements to register | |
417 | * | |
418 | * Registers the specified family and operations from the specified table. | |
419 | * Only one family may be registered with the same family name or identifier. | |
420 | * | |
421 | * The family id may equal GENL_ID_GENERATE causing an unique id to | |
422 | * be automatically generated and assigned. | |
423 | * | |
424 | * Either a doit or dumpit callback must be specified for every registered | |
425 | * operation or the function will fail. Only one operation structure per | |
426 | * command identifier may be registered. | |
427 | * | |
428 | * See include/net/genetlink.h for more documenation on the operations | |
429 | * structure. | |
430 | * | |
431 | * This is equivalent to calling genl_register_family() followed by | |
432 | * genl_register_ops() for every operation entry in the table taking | |
433 | * care to unregister the family on error path. | |
434 | * | |
435 | * Return 0 on success or a negative error code. | |
436 | */ | |
437 | int genl_register_family_with_ops(struct genl_family *family, | |
438 | struct genl_ops *ops, size_t n_ops) | |
439 | { | |
440 | int err, i; | |
441 | ||
442 | err = genl_register_family(family); | |
443 | if (err) | |
444 | return err; | |
445 | ||
446 | for (i = 0; i < n_ops; ++i, ++ops) { | |
447 | err = genl_register_ops(family, ops); | |
448 | if (err) | |
449 | goto err_out; | |
450 | } | |
451 | return 0; | |
452 | err_out: | |
453 | genl_unregister_family(family); | |
454 | return err; | |
455 | } | |
456 | EXPORT_SYMBOL(genl_register_family_with_ops); | |
457 | ||
482a8524 TG |
458 | /** |
459 | * genl_unregister_family - unregister generic netlink family | |
460 | * @family: generic netlink family | |
461 | * | |
462 | * Unregisters the specified family. | |
463 | * | |
464 | * Returns 0 on success or a negative error code. | |
465 | */ | |
466 | int genl_unregister_family(struct genl_family *family) | |
467 | { | |
468 | struct genl_family *rc; | |
469 | ||
470 | genl_lock(); | |
471 | ||
910d6c32 PE |
472 | genl_unregister_mc_groups(family); |
473 | ||
482a8524 TG |
474 | list_for_each_entry(rc, genl_family_chain(family->id), family_list) { |
475 | if (family->id != rc->id || strcmp(rc->name, family->name)) | |
476 | continue; | |
477 | ||
478 | list_del(&rc->family_list); | |
479 | INIT_LIST_HEAD(&family->ops_list); | |
480 | genl_unlock(); | |
481 | ||
482a8524 TG |
482 | kfree(family->attrbuf); |
483 | genl_ctrl_event(CTRL_CMD_DELFAMILY, family); | |
484 | return 0; | |
485 | } | |
486 | ||
487 | genl_unlock(); | |
488 | ||
489 | return -ENOENT; | |
490 | } | |
416c2f9c | 491 | EXPORT_SYMBOL(genl_unregister_family); |
482a8524 | 492 | |
1d00a4eb | 493 | static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
482a8524 TG |
494 | { |
495 | struct genl_ops *ops; | |
496 | struct genl_family *family; | |
134e6375 | 497 | struct net *net = sock_net(skb->sk); |
482a8524 TG |
498 | struct genl_info info; |
499 | struct genlmsghdr *hdr = nlmsg_data(nlh); | |
1d00a4eb | 500 | int hdrlen, err; |
482a8524 | 501 | |
746fac4d | 502 | family = genl_family_find_byid(nlh->nlmsg_type); |
1d00a4eb TG |
503 | if (family == NULL) |
504 | return -ENOENT; | |
482a8524 | 505 | |
134e6375 JB |
506 | /* this family doesn't exist in this netns */ |
507 | if (!family->netnsok && !net_eq(net, &init_net)) | |
508 | return -ENOENT; | |
509 | ||
482a8524 TG |
510 | hdrlen = GENL_HDRLEN + family->hdrsize; |
511 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
1d00a4eb | 512 | return -EINVAL; |
482a8524 TG |
513 | |
514 | ops = genl_get_cmd(hdr->cmd, family); | |
1d00a4eb TG |
515 | if (ops == NULL) |
516 | return -EOPNOTSUPP; | |
482a8524 | 517 | |
1d00a4eb TG |
518 | if ((ops->flags & GENL_ADMIN_PERM) && |
519 | security_netlink_recv(skb, CAP_NET_ADMIN)) | |
520 | return -EPERM; | |
482a8524 | 521 | |
b8f3ab42 | 522 | if (nlh->nlmsg_flags & NLM_F_DUMP) { |
1d00a4eb TG |
523 | if (ops->dumpit == NULL) |
524 | return -EOPNOTSUPP; | |
482a8524 | 525 | |
6d1a3fb5 | 526 | genl_unlock(); |
134e6375 | 527 | err = netlink_dump_start(net->genl_sock, skb, nlh, |
6d1a3fb5 PM |
528 | ops->dumpit, ops->done); |
529 | genl_lock(); | |
530 | return err; | |
482a8524 TG |
531 | } |
532 | ||
1d00a4eb TG |
533 | if (ops->doit == NULL) |
534 | return -EOPNOTSUPP; | |
482a8524 TG |
535 | |
536 | if (family->attrbuf) { | |
537 | err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr, | |
538 | ops->policy); | |
539 | if (err < 0) | |
1d00a4eb | 540 | return err; |
482a8524 TG |
541 | } |
542 | ||
543 | info.snd_seq = nlh->nlmsg_seq; | |
544 | info.snd_pid = NETLINK_CB(skb).pid; | |
545 | info.nlhdr = nlh; | |
546 | info.genlhdr = nlmsg_data(nlh); | |
547 | info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; | |
548 | info.attrs = family->attrbuf; | |
134e6375 | 549 | genl_info_net_set(&info, net); |
ff4c92d8 | 550 | memset(&info.user_ptr, 0, sizeof(info.user_ptr)); |
482a8524 | 551 | |
ff4c92d8 JB |
552 | if (family->pre_doit) { |
553 | err = family->pre_doit(ops, skb, &info); | |
554 | if (err) | |
555 | return err; | |
556 | } | |
557 | ||
558 | err = ops->doit(skb, &info); | |
559 | ||
560 | if (family->post_doit) | |
561 | family->post_doit(ops, skb, &info); | |
562 | ||
563 | return err; | |
482a8524 TG |
564 | } |
565 | ||
cd40b7d3 | 566 | static void genl_rcv(struct sk_buff *skb) |
482a8524 | 567 | { |
cd40b7d3 DL |
568 | genl_lock(); |
569 | netlink_rcv_skb(skb, &genl_rcv_msg); | |
570 | genl_unlock(); | |
482a8524 TG |
571 | } |
572 | ||
573 | /************************************************************************** | |
574 | * Controller | |
575 | **************************************************************************/ | |
576 | ||
17c157c8 TG |
577 | static struct genl_family genl_ctrl = { |
578 | .id = GENL_ID_CTRL, | |
579 | .name = "nlctrl", | |
334c29a6 | 580 | .version = 0x2, |
17c157c8 | 581 | .maxattr = CTRL_ATTR_MAX, |
134e6375 | 582 | .netnsok = true, |
17c157c8 TG |
583 | }; |
584 | ||
482a8524 TG |
585 | static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq, |
586 | u32 flags, struct sk_buff *skb, u8 cmd) | |
587 | { | |
588 | void *hdr; | |
589 | ||
17c157c8 | 590 | hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd); |
482a8524 TG |
591 | if (hdr == NULL) |
592 | return -1; | |
593 | ||
594 | NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name); | |
595 | NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id); | |
eb328111 TG |
596 | NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version); |
597 | NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize); | |
598 | NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr); | |
599 | ||
e94ef682 TG |
600 | if (!list_empty(&family->ops_list)) { |
601 | struct nlattr *nla_ops; | |
602 | struct genl_ops *ops; | |
603 | int idx = 1; | |
eb328111 | 604 | |
e94ef682 TG |
605 | nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS); |
606 | if (nla_ops == NULL) | |
eb328111 TG |
607 | goto nla_put_failure; |
608 | ||
e94ef682 TG |
609 | list_for_each_entry(ops, &family->ops_list, ops_list) { |
610 | struct nlattr *nest; | |
eb328111 | 611 | |
e94ef682 TG |
612 | nest = nla_nest_start(skb, idx++); |
613 | if (nest == NULL) | |
614 | goto nla_put_failure; | |
eb328111 | 615 | |
e94ef682 TG |
616 | NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd); |
617 | NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags); | |
eb328111 | 618 | |
e94ef682 TG |
619 | nla_nest_end(skb, nest); |
620 | } | |
621 | ||
622 | nla_nest_end(skb, nla_ops); | |
623 | } | |
482a8524 | 624 | |
2dbba6f7 JB |
625 | if (!list_empty(&family->mcast_groups)) { |
626 | struct genl_multicast_group *grp; | |
627 | struct nlattr *nla_grps; | |
628 | int idx = 1; | |
629 | ||
630 | nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); | |
631 | if (nla_grps == NULL) | |
632 | goto nla_put_failure; | |
633 | ||
634 | list_for_each_entry(grp, &family->mcast_groups, list) { | |
635 | struct nlattr *nest; | |
636 | ||
637 | nest = nla_nest_start(skb, idx++); | |
638 | if (nest == NULL) | |
639 | goto nla_put_failure; | |
640 | ||
641 | NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id); | |
642 | NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME, | |
643 | grp->name); | |
644 | ||
645 | nla_nest_end(skb, nest); | |
646 | } | |
647 | nla_nest_end(skb, nla_grps); | |
648 | } | |
649 | ||
650 | return genlmsg_end(skb, hdr); | |
651 | ||
652 | nla_put_failure: | |
bc3ed28c TG |
653 | genlmsg_cancel(skb, hdr); |
654 | return -EMSGSIZE; | |
2dbba6f7 JB |
655 | } |
656 | ||
657 | static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid, | |
658 | u32 seq, u32 flags, struct sk_buff *skb, | |
659 | u8 cmd) | |
660 | { | |
661 | void *hdr; | |
662 | struct nlattr *nla_grps; | |
663 | struct nlattr *nest; | |
664 | ||
665 | hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd); | |
666 | if (hdr == NULL) | |
667 | return -1; | |
668 | ||
669 | NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name); | |
670 | NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id); | |
671 | ||
672 | nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); | |
673 | if (nla_grps == NULL) | |
674 | goto nla_put_failure; | |
675 | ||
676 | nest = nla_nest_start(skb, 1); | |
677 | if (nest == NULL) | |
678 | goto nla_put_failure; | |
679 | ||
680 | NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id); | |
681 | NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME, | |
682 | grp->name); | |
683 | ||
684 | nla_nest_end(skb, nest); | |
685 | nla_nest_end(skb, nla_grps); | |
686 | ||
482a8524 TG |
687 | return genlmsg_end(skb, hdr); |
688 | ||
689 | nla_put_failure: | |
bc3ed28c TG |
690 | genlmsg_cancel(skb, hdr); |
691 | return -EMSGSIZE; | |
482a8524 TG |
692 | } |
693 | ||
694 | static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) | |
695 | { | |
696 | ||
697 | int i, n = 0; | |
698 | struct genl_family *rt; | |
134e6375 | 699 | struct net *net = sock_net(skb->sk); |
482a8524 TG |
700 | int chains_to_skip = cb->args[0]; |
701 | int fams_to_skip = cb->args[1]; | |
702 | ||
e1d5a010 | 703 | for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) { |
482a8524 TG |
704 | n = 0; |
705 | list_for_each_entry(rt, genl_family_chain(i), family_list) { | |
134e6375 JB |
706 | if (!rt->netnsok && !net_eq(net, &init_net)) |
707 | continue; | |
482a8524 TG |
708 | if (++n < fams_to_skip) |
709 | continue; | |
710 | if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid, | |
711 | cb->nlh->nlmsg_seq, NLM_F_MULTI, | |
712 | skb, CTRL_CMD_NEWFAMILY) < 0) | |
713 | goto errout; | |
714 | } | |
715 | ||
716 | fams_to_skip = 0; | |
717 | } | |
718 | ||
719 | errout: | |
720 | cb->args[0] = i; | |
721 | cb->args[1] = n; | |
722 | ||
723 | return skb->len; | |
724 | } | |
725 | ||
2dbba6f7 JB |
726 | static struct sk_buff *ctrl_build_family_msg(struct genl_family *family, |
727 | u32 pid, int seq, u8 cmd) | |
482a8524 TG |
728 | { |
729 | struct sk_buff *skb; | |
730 | int err; | |
731 | ||
339bf98f | 732 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
482a8524 TG |
733 | if (skb == NULL) |
734 | return ERR_PTR(-ENOBUFS); | |
735 | ||
736 | err = ctrl_fill_info(family, pid, seq, 0, skb, cmd); | |
737 | if (err < 0) { | |
738 | nlmsg_free(skb); | |
739 | return ERR_PTR(err); | |
740 | } | |
741 | ||
742 | return skb; | |
743 | } | |
744 | ||
2dbba6f7 JB |
745 | static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp, |
746 | u32 pid, int seq, u8 cmd) | |
747 | { | |
748 | struct sk_buff *skb; | |
749 | int err; | |
750 | ||
751 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
752 | if (skb == NULL) | |
753 | return ERR_PTR(-ENOBUFS); | |
754 | ||
755 | err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd); | |
756 | if (err < 0) { | |
757 | nlmsg_free(skb); | |
758 | return ERR_PTR(err); | |
759 | } | |
760 | ||
761 | return skb; | |
762 | } | |
763 | ||
ef7c79ed | 764 | static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = { |
482a8524 | 765 | [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, |
5176f91e TG |
766 | [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, |
767 | .len = GENL_NAMSIZ - 1 }, | |
482a8524 TG |
768 | }; |
769 | ||
770 | static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) | |
771 | { | |
772 | struct sk_buff *msg; | |
773 | struct genl_family *res = NULL; | |
774 | int err = -EINVAL; | |
775 | ||
776 | if (info->attrs[CTRL_ATTR_FAMILY_ID]) { | |
777 | u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]); | |
778 | res = genl_family_find_byid(id); | |
134e6375 | 779 | err = -ENOENT; |
482a8524 TG |
780 | } |
781 | ||
782 | if (info->attrs[CTRL_ATTR_FAMILY_NAME]) { | |
5176f91e | 783 | char *name; |
482a8524 | 784 | |
5176f91e | 785 | name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]); |
482a8524 | 786 | res = genl_family_find_byname(name); |
134e6375 | 787 | err = -ENOENT; |
482a8524 TG |
788 | } |
789 | ||
134e6375 JB |
790 | if (res == NULL) |
791 | return err; | |
792 | ||
793 | if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) { | |
794 | /* family doesn't exist here */ | |
795 | return -ENOENT; | |
482a8524 TG |
796 | } |
797 | ||
2dbba6f7 JB |
798 | msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq, |
799 | CTRL_CMD_NEWFAMILY); | |
134e6375 JB |
800 | if (IS_ERR(msg)) |
801 | return PTR_ERR(msg); | |
482a8524 | 802 | |
134e6375 | 803 | return genlmsg_reply(msg, info); |
482a8524 TG |
804 | } |
805 | ||
806 | static int genl_ctrl_event(int event, void *data) | |
807 | { | |
808 | struct sk_buff *msg; | |
134e6375 JB |
809 | struct genl_family *family; |
810 | struct genl_multicast_group *grp; | |
482a8524 | 811 | |
134e6375 JB |
812 | /* genl is still initialising */ |
813 | if (!init_net.genl_sock) | |
482a8524 TG |
814 | return 0; |
815 | ||
816 | switch (event) { | |
817 | case CTRL_CMD_NEWFAMILY: | |
818 | case CTRL_CMD_DELFAMILY: | |
134e6375 JB |
819 | family = data; |
820 | msg = ctrl_build_family_msg(family, 0, 0, event); | |
2dbba6f7 JB |
821 | break; |
822 | case CTRL_CMD_NEWMCAST_GRP: | |
823 | case CTRL_CMD_DELMCAST_GRP: | |
134e6375 JB |
824 | grp = data; |
825 | family = grp->family; | |
2dbba6f7 | 826 | msg = ctrl_build_mcgrp_msg(data, 0, 0, event); |
482a8524 | 827 | break; |
134e6375 JB |
828 | default: |
829 | return -EINVAL; | |
830 | } | |
831 | ||
832 | if (IS_ERR(msg)) | |
833 | return PTR_ERR(msg); | |
834 | ||
835 | if (!family->netnsok) { | |
836 | genlmsg_multicast_netns(&init_net, msg, 0, | |
837 | GENL_ID_CTRL, GFP_KERNEL); | |
838 | } else { | |
839 | rcu_read_lock(); | |
840 | genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC); | |
841 | rcu_read_unlock(); | |
482a8524 TG |
842 | } |
843 | ||
844 | return 0; | |
845 | } | |
846 | ||
847 | static struct genl_ops genl_ctrl_ops = { | |
848 | .cmd = CTRL_CMD_GETFAMILY, | |
849 | .doit = ctrl_getfamily, | |
850 | .dumpit = ctrl_dumpfamily, | |
851 | .policy = ctrl_policy, | |
852 | }; | |
853 | ||
2dbba6f7 JB |
854 | static struct genl_multicast_group notify_grp = { |
855 | .name = "notify", | |
856 | }; | |
857 | ||
134e6375 JB |
858 | static int __net_init genl_pernet_init(struct net *net) |
859 | { | |
860 | /* we'll bump the group number right afterwards */ | |
861 | net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0, | |
862 | genl_rcv, &genl_mutex, | |
863 | THIS_MODULE); | |
864 | ||
865 | if (!net->genl_sock && net_eq(net, &init_net)) | |
866 | panic("GENL: Cannot initialize generic netlink\n"); | |
867 | ||
868 | if (!net->genl_sock) | |
869 | return -ENOMEM; | |
870 | ||
871 | return 0; | |
872 | } | |
873 | ||
874 | static void __net_exit genl_pernet_exit(struct net *net) | |
875 | { | |
876 | netlink_kernel_release(net->genl_sock); | |
877 | net->genl_sock = NULL; | |
878 | } | |
879 | ||
880 | static struct pernet_operations genl_pernet_ops = { | |
881 | .init = genl_pernet_init, | |
882 | .exit = genl_pernet_exit, | |
883 | }; | |
884 | ||
482a8524 TG |
885 | static int __init genl_init(void) |
886 | { | |
887 | int i, err; | |
888 | ||
889 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | |
890 | INIT_LIST_HEAD(&family_ht[i]); | |
891 | ||
652c6717 | 892 | err = genl_register_family_with_ops(&genl_ctrl, &genl_ctrl_ops, 1); |
482a8524 | 893 | if (err < 0) |
134e6375 | 894 | goto problem; |
482a8524 TG |
895 | |
896 | netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV); | |
2dbba6f7 | 897 | |
134e6375 JB |
898 | err = register_pernet_subsys(&genl_pernet_ops); |
899 | if (err) | |
900 | goto problem; | |
482a8524 | 901 | |
2dbba6f7 JB |
902 | err = genl_register_mc_group(&genl_ctrl, ¬ify_grp); |
903 | if (err < 0) | |
134e6375 | 904 | goto problem; |
2dbba6f7 | 905 | |
482a8524 TG |
906 | return 0; |
907 | ||
134e6375 | 908 | problem: |
482a8524 | 909 | panic("GENL: Cannot register controller: %d\n", err); |
482a8524 TG |
910 | } |
911 | ||
912 | subsys_initcall(genl_init); | |
913 | ||
134e6375 JB |
914 | static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group, |
915 | gfp_t flags) | |
916 | { | |
917 | struct sk_buff *tmp; | |
918 | struct net *net, *prev = NULL; | |
919 | int err; | |
920 | ||
921 | for_each_net_rcu(net) { | |
922 | if (prev) { | |
923 | tmp = skb_clone(skb, flags); | |
924 | if (!tmp) { | |
925 | err = -ENOMEM; | |
926 | goto error; | |
927 | } | |
928 | err = nlmsg_multicast(prev->genl_sock, tmp, | |
929 | pid, group, flags); | |
930 | if (err) | |
931 | goto error; | |
932 | } | |
933 | ||
934 | prev = net; | |
935 | } | |
936 | ||
937 | return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags); | |
938 | error: | |
939 | kfree_skb(skb); | |
940 | return err; | |
941 | } | |
942 | ||
943 | int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group, | |
944 | gfp_t flags) | |
945 | { | |
946 | return genlmsg_mcast(skb, pid, group, flags); | |
947 | } | |
948 | EXPORT_SYMBOL(genlmsg_multicast_allns); |