blob: 1781d99145e2d2594fc961e1a2fc9307aad957a5 [file] [log] [blame]
Thomas Graf482a8522005-11-10 02:25:56 +01001/*
2 * NETLINK Generic Netlink Family
3 *
4 * Authors: Jamal Hadi Salim
5 * Thomas Graf <tgraf@suug.ch>
Johannes Berg2dbba6f2007-07-18 15:47:52 -07006 * Johannes Berg <johannes@sipsolutions.net>
Thomas Graf482a8522005-11-10 02:25:56 +01007 */
8
Thomas Graf482a8522005-11-10 02:25:56 +01009#include <linux/module.h>
10#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090011#include <linux/slab.h>
Thomas Graf482a8522005-11-10 02:25:56 +010012#include <linux/errno.h>
13#include <linux/types.h>
14#include <linux/socket.h>
15#include <linux/string.h>
16#include <linux/skbuff.h>
Ingo Molnar14cc3e22006-03-26 01:37:14 -080017#include <linux/mutex.h>
Johannes Berg2dbba6f2007-07-18 15:47:52 -070018#include <linux/bitmap.h>
Thomas Graf482a8522005-11-10 02:25:56 +010019#include <net/sock.h>
20#include <net/genetlink.h>
21
Ingo Molnar14cc3e22006-03-26 01:37:14 -080022static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
Thomas Graf482a8522005-11-10 02:25:56 +010023
James Chapmanf408e0c2010-04-02 06:19:05 +000024void genl_lock(void)
Thomas Graf482a8522005-11-10 02:25:56 +010025{
Ingo Molnar14cc3e22006-03-26 01:37:14 -080026 mutex_lock(&genl_mutex);
Thomas Graf482a8522005-11-10 02:25:56 +010027}
James Chapmanf408e0c2010-04-02 06:19:05 +000028EXPORT_SYMBOL(genl_lock);
Thomas Graf482a8522005-11-10 02:25:56 +010029
James Chapmanf408e0c2010-04-02 06:19:05 +000030void genl_unlock(void)
Thomas Graf482a8522005-11-10 02:25:56 +010031{
Ingo Molnar14cc3e22006-03-26 01:37:14 -080032 mutex_unlock(&genl_mutex);
Thomas Graf482a8522005-11-10 02:25:56 +010033}
James Chapmanf408e0c2010-04-02 06:19:05 +000034EXPORT_SYMBOL(genl_unlock);
Thomas Graf482a8522005-11-10 02:25:56 +010035
36#define GENL_FAM_TAB_SIZE 16
37#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
38
39static struct list_head family_ht[GENL_FAM_TAB_SIZE];
Johannes Berg2dbba6f2007-07-18 15:47:52 -070040/*
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 */
47static unsigned long mc_group_start = 0x1;
48static unsigned long *mc_groups = &mc_group_start;
49static unsigned long mc_groups_longs = 1;
Thomas Graf482a8522005-11-10 02:25:56 +010050
51static int genl_ctrl_event(int event, void *data);
52
53static inline unsigned int genl_family_hash(unsigned int id)
54{
55 return id & GENL_FAM_TAB_MASK;
56}
57
58static inline struct list_head *genl_family_chain(unsigned int id)
59{
60 return &family_ht[genl_family_hash(id)];
61}
62
63static 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
74static 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
87static 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*/
101static inline u16 genl_generate_id(void)
102{
Krishna Kumar988ade62009-10-14 19:55:07 +0000103 static u16 id_gen_idx = GENL_MIN_ID;
104 int i;
Thomas Graf482a8522005-11-10 02:25:56 +0100105
Krishna Kumar988ade62009-10-14 19:55:07 +0000106 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)
Thomas Graf482a8522005-11-10 02:25:56 +0100110 id_gen_idx = GENL_MIN_ID;
Krishna Kumar988ade62009-10-14 19:55:07 +0000111 }
Thomas Graf482a8522005-11-10 02:25:56 +0100112
Krishna Kumar988ade62009-10-14 19:55:07 +0000113 return 0;
Thomas Graf482a8522005-11-10 02:25:56 +0100114}
115
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700116static 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 */
129int genl_register_mc_group(struct genl_family *family,
130 struct genl_multicast_group *grp)
131{
132 int id;
133 unsigned long *new_groups;
Brian Haleyb1f57192009-09-04 20:36:52 -0700134 int err = 0;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700135
136 BUG_ON(grp->name[0] == '\0');
137
138 genl_lock();
139
140 /* special-case our own group */
141 if (grp == &notify_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
Johannes Berg134e6372009-07-10 09:51:34 +0000171 if (family->netnsok) {
172 struct net *net;
173
Johannes Bergd136f1b2009-09-12 03:03:15 +0000174 netlink_table_grab();
Johannes Berg134e6372009-07-10 09:51:34 +0000175 rcu_read_lock();
176 for_each_net_rcu(net) {
Johannes Bergd136f1b2009-09-12 03:03:15 +0000177 err = __netlink_change_ngroups(net->genl_sock,
Johannes Berg134e6372009-07-10 09:51:34 +0000178 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();
Johannes Bergd136f1b2009-09-12 03:03:15 +0000187 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000188 goto out;
189 }
190 }
191 rcu_read_unlock();
Johannes Bergd136f1b2009-09-12 03:03:15 +0000192 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000193 } else {
194 err = netlink_change_ngroups(init_net.genl_sock,
195 mc_groups_longs * BITS_PER_LONG);
196 if (err)
197 goto out;
198 }
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700199
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();
Thomas Graf79d310d2007-07-24 15:34:53 -0700208 return err;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700209}
210EXPORT_SYMBOL(genl_register_mc_group);
211
Thomas Graf79dc43862007-07-24 15:32:46 -0700212static void __genl_unregister_mc_group(struct genl_family *family,
213 struct genl_multicast_group *grp)
214{
Johannes Berg134e6372009-07-10 09:51:34 +0000215 struct net *net;
Thomas Graf79dc43862007-07-24 15:32:46 -0700216 BUG_ON(grp->family != family);
Johannes Berg134e6372009-07-10 09:51:34 +0000217
Johannes Bergb8273572009-09-24 15:44:05 -0700218 netlink_table_grab();
Johannes Berg134e6372009-07-10 09:51:34 +0000219 rcu_read_lock();
220 for_each_net_rcu(net)
Johannes Bergb8273572009-09-24 15:44:05 -0700221 __netlink_clear_multicast_users(net->genl_sock, grp->id);
Johannes Berg134e6372009-07-10 09:51:34 +0000222 rcu_read_unlock();
Johannes Bergb8273572009-09-24 15:44:05 -0700223 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000224
Thomas Graf79dc43862007-07-24 15:32:46 -0700225 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
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700232/**
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 */
246void genl_unregister_mc_group(struct genl_family *family,
247 struct genl_multicast_group *grp)
248{
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700249 genl_lock();
Thomas Graf79dc43862007-07-24 15:32:46 -0700250 __genl_unregister_mc_group(family, grp);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700251 genl_unlock();
252}
Inaky Perez-Gonzalez3efb40c2008-12-20 16:57:37 -0800253EXPORT_SYMBOL(genl_unregister_mc_group);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700254
255static 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)
Thomas Graf79dc43862007-07-24 15:32:46 -0700260 __genl_unregister_mc_group(family, grp);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700261}
262
Thomas Graf482a8522005-11-10 02:25:56 +0100263/**
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 */
278int 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
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800290 if (ops->dumpit)
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800291 ops->flags |= GENL_CMD_CAP_DUMP;
Jamal Hadi Salim48d4ed72006-12-06 20:06:25 -0800292 if (ops->doit)
293 ops->flags |= GENL_CMD_CAP_DO;
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800294 if (ops->policy)
295 ops->flags |= GENL_CMD_CAP_HASPOL;
296
Thomas Graf482a8522005-11-10 02:25:56 +0100297 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;
303errout:
304 return err;
305}
Changli Gao416c2f92010-07-25 20:46:01 +0000306EXPORT_SYMBOL(genl_register_ops);
Thomas Graf482a8522005-11-10 02:25:56 +0100307
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 */
324int 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}
Changli Gao416c2f92010-07-25 20:46:01 +0000341EXPORT_SYMBOL(genl_unregister_ops);
Thomas Graf482a8522005-11-10 02:25:56 +0100342
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 */
354int 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);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700365 INIT_LIST_HEAD(&family->mcast_groups);
Thomas Graf482a8522005-11-10 02:25:56 +0100366
367 genl_lock();
368
369 if (genl_family_find_byname(family->name)) {
370 err = -EEXIST;
371 goto errout_locked;
372 }
373
Thomas Graf482a8522005-11-10 02:25:56 +0100374 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;
Krishna Kumar93860b02009-10-14 19:54:53 +0000383 } else if (genl_family_find_byid(family->id)) {
384 err = -EEXIST;
385 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100386 }
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;
Jamal Hadi Salime200bd82006-02-13 15:51:24 -0800393 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100394 }
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
405errout_locked:
406 genl_unlock();
407errout:
408 return err;
409}
Changli Gao416c2f92010-07-25 20:46:01 +0000410EXPORT_SYMBOL(genl_register_family);
Thomas Graf482a8522005-11-10 02:25:56 +0100411
412/**
Michał Mirosława7b11d72009-05-21 10:34:04 +0000413 * 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 */
437int 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;
452err_out:
453 genl_unregister_family(family);
454 return err;
455}
456EXPORT_SYMBOL(genl_register_family_with_ops);
457
458/**
Thomas Graf482a8522005-11-10 02:25:56 +0100459 * 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 */
466int genl_unregister_family(struct genl_family *family)
467{
468 struct genl_family *rc;
469
470 genl_lock();
471
Pavel Emelyanov910d6c32008-02-12 22:16:33 -0800472 genl_unregister_mc_groups(family);
473
Thomas Graf482a8522005-11-10 02:25:56 +0100474 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
Thomas Graf482a8522005-11-10 02:25:56 +0100482 kfree(family->attrbuf);
483 genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
484 return 0;
485 }
486
487 genl_unlock();
488
489 return -ENOENT;
490}
Changli Gao416c2f92010-07-25 20:46:01 +0000491EXPORT_SYMBOL(genl_unregister_family);
Thomas Graf482a8522005-11-10 02:25:56 +0100492
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700493static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
Thomas Graf482a8522005-11-10 02:25:56 +0100494{
495 struct genl_ops *ops;
496 struct genl_family *family;
Johannes Berg134e6372009-07-10 09:51:34 +0000497 struct net *net = sock_net(skb->sk);
Thomas Graf482a8522005-11-10 02:25:56 +0100498 struct genl_info info;
499 struct genlmsghdr *hdr = nlmsg_data(nlh);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700500 int hdrlen, err;
Thomas Graf482a8522005-11-10 02:25:56 +0100501
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900502 family = genl_family_find_byid(nlh->nlmsg_type);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700503 if (family == NULL)
504 return -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100505
Johannes Berg134e6372009-07-10 09:51:34 +0000506 /* this family doesn't exist in this netns */
507 if (!family->netnsok && !net_eq(net, &init_net))
508 return -ENOENT;
509
Thomas Graf482a8522005-11-10 02:25:56 +0100510 hdrlen = GENL_HDRLEN + family->hdrsize;
511 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700512 return -EINVAL;
Thomas Graf482a8522005-11-10 02:25:56 +0100513
514 ops = genl_get_cmd(hdr->cmd, family);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700515 if (ops == NULL)
516 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100517
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700518 if ((ops->flags & GENL_ADMIN_PERM) &&
519 security_netlink_recv(skb, CAP_NET_ADMIN))
520 return -EPERM;
Thomas Graf482a8522005-11-10 02:25:56 +0100521
David S. Millerb8f3ab42011-01-18 12:40:38 -0800522 if (nlh->nlmsg_flags & NLM_F_DUMP) {
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700523 if (ops->dumpit == NULL)
524 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100525
Patrick McHardy6d1a3fb2008-06-18 02:07:07 -0700526 genl_unlock();
Johannes Berg134e6372009-07-10 09:51:34 +0000527 err = netlink_dump_start(net->genl_sock, skb, nlh,
Patrick McHardy6d1a3fb2008-06-18 02:07:07 -0700528 ops->dumpit, ops->done);
529 genl_lock();
530 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100531 }
532
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700533 if (ops->doit == NULL)
534 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100535
536 if (family->attrbuf) {
537 err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
538 ops->policy);
539 if (err < 0)
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700540 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100541 }
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;
Johannes Berg134e6372009-07-10 09:51:34 +0000549 genl_info_net_set(&info, net);
Johannes Bergff4c92d2010-10-04 21:14:03 +0200550 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
Thomas Graf482a8522005-11-10 02:25:56 +0100551
Johannes Bergff4c92d2010-10-04 21:14:03 +0200552 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;
Thomas Graf482a8522005-11-10 02:25:56 +0100564}
565
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700566static void genl_rcv(struct sk_buff *skb)
Thomas Graf482a8522005-11-10 02:25:56 +0100567{
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700568 genl_lock();
569 netlink_rcv_skb(skb, &genl_rcv_msg);
570 genl_unlock();
Thomas Graf482a8522005-11-10 02:25:56 +0100571}
572
573/**************************************************************************
574 * Controller
575 **************************************************************************/
576
Thomas Graf17c157c2006-11-14 19:46:02 -0800577static struct genl_family genl_ctrl = {
578 .id = GENL_ID_CTRL,
579 .name = "nlctrl",
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800580 .version = 0x2,
Thomas Graf17c157c2006-11-14 19:46:02 -0800581 .maxattr = CTRL_ATTR_MAX,
Johannes Berg134e6372009-07-10 09:51:34 +0000582 .netnsok = true,
Thomas Graf17c157c2006-11-14 19:46:02 -0800583};
584
Thomas Graf482a8522005-11-10 02:25:56 +0100585static 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
Thomas Graf17c157c2006-11-14 19:46:02 -0800590 hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
Thomas Graf482a8522005-11-10 02:25:56 +0100591 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);
Thomas Grafeb328112006-09-18 00:01:59 -0700596 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
Thomas Grafe94ef682006-11-23 11:44:37 -0800600 if (!list_empty(&family->ops_list)) {
601 struct nlattr *nla_ops;
602 struct genl_ops *ops;
603 int idx = 1;
Thomas Grafeb328112006-09-18 00:01:59 -0700604
Thomas Grafe94ef682006-11-23 11:44:37 -0800605 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
606 if (nla_ops == NULL)
Thomas Grafeb328112006-09-18 00:01:59 -0700607 goto nla_put_failure;
608
Thomas Grafe94ef682006-11-23 11:44:37 -0800609 list_for_each_entry(ops, &family->ops_list, ops_list) {
610 struct nlattr *nest;
Thomas Grafeb328112006-09-18 00:01:59 -0700611
Thomas Grafe94ef682006-11-23 11:44:37 -0800612 nest = nla_nest_start(skb, idx++);
613 if (nest == NULL)
614 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700615
Thomas Grafe94ef682006-11-23 11:44:37 -0800616 NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
617 NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
Thomas Grafeb328112006-09-18 00:01:59 -0700618
Thomas Grafe94ef682006-11-23 11:44:37 -0800619 nla_nest_end(skb, nest);
620 }
621
622 nla_nest_end(skb, nla_ops);
Thomas Grafeb328112006-09-18 00:01:59 -0700623 }
624
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700625 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
652nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700653 genlmsg_cancel(skb, hdr);
654 return -EMSGSIZE;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700655}
656
657static 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
Thomas Graf482a8522005-11-10 02:25:56 +0100687 return genlmsg_end(skb, hdr);
688
689nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700690 genlmsg_cancel(skb, hdr);
691 return -EMSGSIZE;
Thomas Graf482a8522005-11-10 02:25:56 +0100692}
693
694static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
695{
696
697 int i, n = 0;
698 struct genl_family *rt;
Johannes Berg134e6372009-07-10 09:51:34 +0000699 struct net *net = sock_net(skb->sk);
Thomas Graf482a8522005-11-10 02:25:56 +0100700 int chains_to_skip = cb->args[0];
701 int fams_to_skip = cb->args[1];
702
Samir Bellabese1d5a012010-01-07 22:10:56 +0000703 for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
Thomas Graf482a8522005-11-10 02:25:56 +0100704 n = 0;
705 list_for_each_entry(rt, genl_family_chain(i), family_list) {
Johannes Berg134e6372009-07-10 09:51:34 +0000706 if (!rt->netnsok && !net_eq(net, &init_net))
707 continue;
Thomas Graf482a8522005-11-10 02:25:56 +0100708 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
719errout:
720 cb->args[0] = i;
721 cb->args[1] = n;
722
723 return skb->len;
724}
725
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700726static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
727 u32 pid, int seq, u8 cmd)
Thomas Graf482a8522005-11-10 02:25:56 +0100728{
729 struct sk_buff *skb;
730 int err;
731
Thomas Graf339bf982006-11-10 14:10:15 -0800732 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
Thomas Graf482a8522005-11-10 02:25:56 +0100733 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
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700745static 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
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700764static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
Thomas Graf482a8522005-11-10 02:25:56 +0100765 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
Thomas Graf5176f912006-08-26 20:13:18 -0700766 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
767 .len = GENL_NAMSIZ - 1 },
Thomas Graf482a8522005-11-10 02:25:56 +0100768};
769
770static 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);
Johannes Berg134e6372009-07-10 09:51:34 +0000779 err = -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100780 }
781
782 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
Thomas Graf5176f912006-08-26 20:13:18 -0700783 char *name;
Thomas Graf482a8522005-11-10 02:25:56 +0100784
Thomas Graf5176f912006-08-26 20:13:18 -0700785 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
Thomas Graf482a8522005-11-10 02:25:56 +0100786 res = genl_family_find_byname(name);
Johannes Berg134e6372009-07-10 09:51:34 +0000787 err = -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100788 }
789
Johannes Berg134e6372009-07-10 09:51:34 +0000790 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;
Thomas Graf482a8522005-11-10 02:25:56 +0100796 }
797
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700798 msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
799 CTRL_CMD_NEWFAMILY);
Johannes Berg134e6372009-07-10 09:51:34 +0000800 if (IS_ERR(msg))
801 return PTR_ERR(msg);
Thomas Graf482a8522005-11-10 02:25:56 +0100802
Johannes Berg134e6372009-07-10 09:51:34 +0000803 return genlmsg_reply(msg, info);
Thomas Graf482a8522005-11-10 02:25:56 +0100804}
805
806static int genl_ctrl_event(int event, void *data)
807{
808 struct sk_buff *msg;
Johannes Berg134e6372009-07-10 09:51:34 +0000809 struct genl_family *family;
810 struct genl_multicast_group *grp;
Thomas Graf482a8522005-11-10 02:25:56 +0100811
Johannes Berg134e6372009-07-10 09:51:34 +0000812 /* genl is still initialising */
813 if (!init_net.genl_sock)
Thomas Graf482a8522005-11-10 02:25:56 +0100814 return 0;
815
816 switch (event) {
817 case CTRL_CMD_NEWFAMILY:
818 case CTRL_CMD_DELFAMILY:
Johannes Berg134e6372009-07-10 09:51:34 +0000819 family = data;
820 msg = ctrl_build_family_msg(family, 0, 0, event);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700821 break;
822 case CTRL_CMD_NEWMCAST_GRP:
823 case CTRL_CMD_DELMCAST_GRP:
Johannes Berg134e6372009-07-10 09:51:34 +0000824 grp = data;
825 family = grp->family;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700826 msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
Thomas Graf482a8522005-11-10 02:25:56 +0100827 break;
Johannes Berg134e6372009-07-10 09:51:34 +0000828 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();
Thomas Graf482a8522005-11-10 02:25:56 +0100842 }
843
844 return 0;
845}
846
847static 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
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700854static struct genl_multicast_group notify_grp = {
855 .name = "notify",
856};
857
Johannes Berg134e6372009-07-10 09:51:34 +0000858static 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
874static void __net_exit genl_pernet_exit(struct net *net)
875{
876 netlink_kernel_release(net->genl_sock);
877 net->genl_sock = NULL;
878}
879
880static struct pernet_operations genl_pernet_ops = {
881 .init = genl_pernet_init,
882 .exit = genl_pernet_exit,
883};
884
Thomas Graf482a8522005-11-10 02:25:56 +0100885static 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
Changli Gao652c6712010-07-25 23:21:05 +0000892 err = genl_register_family_with_ops(&genl_ctrl, &genl_ctrl_ops, 1);
Thomas Graf482a8522005-11-10 02:25:56 +0100893 if (err < 0)
Johannes Berg134e6372009-07-10 09:51:34 +0000894 goto problem;
Thomas Graf482a8522005-11-10 02:25:56 +0100895
896 netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700897
Johannes Berg134e6372009-07-10 09:51:34 +0000898 err = register_pernet_subsys(&genl_pernet_ops);
899 if (err)
900 goto problem;
Thomas Graf482a8522005-11-10 02:25:56 +0100901
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700902 err = genl_register_mc_group(&genl_ctrl, &notify_grp);
903 if (err < 0)
Johannes Berg134e6372009-07-10 09:51:34 +0000904 goto problem;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700905
Thomas Graf482a8522005-11-10 02:25:56 +0100906 return 0;
907
Johannes Berg134e6372009-07-10 09:51:34 +0000908problem:
Thomas Graf482a8522005-11-10 02:25:56 +0100909 panic("GENL: Cannot register controller: %d\n", err);
Thomas Graf482a8522005-11-10 02:25:56 +0100910}
911
912subsys_initcall(genl_init);
913
Johannes Berg134e6372009-07-10 09:51:34 +0000914static 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
943int 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}
948EXPORT_SYMBOL(genlmsg_multicast_allns);