blob: fda497412fc34a5b10aa25a1c7599118d5e832a8 [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
WANG Cong320f5ea2012-07-24 13:44:01 +080036#ifdef CONFIG_LOCKDEP
Pravin B Shelar86b13092011-11-10 19:14:51 -080037int lockdep_genl_is_held(void)
38{
39 return lockdep_is_held(&genl_mutex);
40}
41EXPORT_SYMBOL(lockdep_genl_is_held);
42#endif
43
Thomas Graf482a8522005-11-10 02:25:56 +010044#define GENL_FAM_TAB_SIZE 16
45#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
46
47static struct list_head family_ht[GENL_FAM_TAB_SIZE];
Johannes Berg2dbba6f2007-07-18 15:47:52 -070048/*
49 * Bitmap of multicast groups that are currently in use.
50 *
51 * To avoid an allocation at boot of just one unsigned long,
52 * declare it global instead.
53 * Bit 0 is marked as already used since group 0 is invalid.
54 */
55static unsigned long mc_group_start = 0x1;
56static unsigned long *mc_groups = &mc_group_start;
57static unsigned long mc_groups_longs = 1;
Thomas Graf482a8522005-11-10 02:25:56 +010058
59static int genl_ctrl_event(int event, void *data);
60
61static inline unsigned int genl_family_hash(unsigned int id)
62{
63 return id & GENL_FAM_TAB_MASK;
64}
65
66static inline struct list_head *genl_family_chain(unsigned int id)
67{
68 return &family_ht[genl_family_hash(id)];
69}
70
71static struct genl_family *genl_family_find_byid(unsigned int id)
72{
73 struct genl_family *f;
74
75 list_for_each_entry(f, genl_family_chain(id), family_list)
76 if (f->id == id)
77 return f;
78
79 return NULL;
80}
81
82static struct genl_family *genl_family_find_byname(char *name)
83{
84 struct genl_family *f;
85 int i;
86
87 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
88 list_for_each_entry(f, genl_family_chain(i), family_list)
89 if (strcmp(f->name, name) == 0)
90 return f;
91
92 return NULL;
93}
94
95static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
96{
97 struct genl_ops *ops;
98
99 list_for_each_entry(ops, &family->ops_list, ops_list)
100 if (ops->cmd == cmd)
101 return ops;
102
103 return NULL;
104}
105
106/* Of course we are going to have problems once we hit
107 * 2^16 alive types, but that can only happen by year 2K
108*/
stephen hemmingerb57ef81f2011-12-22 08:52:02 +0000109static u16 genl_generate_id(void)
Thomas Graf482a8522005-11-10 02:25:56 +0100110{
Krishna Kumar988ade62009-10-14 19:55:07 +0000111 static u16 id_gen_idx = GENL_MIN_ID;
112 int i;
Thomas Graf482a8522005-11-10 02:25:56 +0100113
Krishna Kumar988ade62009-10-14 19:55:07 +0000114 for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
115 if (!genl_family_find_byid(id_gen_idx))
116 return id_gen_idx;
117 if (++id_gen_idx > GENL_MAX_ID)
Thomas Graf482a8522005-11-10 02:25:56 +0100118 id_gen_idx = GENL_MIN_ID;
Krishna Kumar988ade62009-10-14 19:55:07 +0000119 }
Thomas Graf482a8522005-11-10 02:25:56 +0100120
Krishna Kumar988ade62009-10-14 19:55:07 +0000121 return 0;
Thomas Graf482a8522005-11-10 02:25:56 +0100122}
123
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700124static struct genl_multicast_group notify_grp;
125
126/**
127 * genl_register_mc_group - register a multicast group
128 *
129 * Registers the specified multicast group and notifies userspace
130 * about the new group.
131 *
132 * Returns 0 on success or a negative error code.
133 *
134 * @family: The generic netlink family the group shall be registered for.
135 * @grp: The group to register, must have a name.
136 */
137int genl_register_mc_group(struct genl_family *family,
138 struct genl_multicast_group *grp)
139{
140 int id;
141 unsigned long *new_groups;
Brian Haleyb1f57192009-09-04 20:36:52 -0700142 int err = 0;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700143
144 BUG_ON(grp->name[0] == '\0');
145
146 genl_lock();
147
148 /* special-case our own group */
149 if (grp == &notify_grp)
150 id = GENL_ID_CTRL;
151 else
152 id = find_first_zero_bit(mc_groups,
153 mc_groups_longs * BITS_PER_LONG);
154
155
156 if (id >= mc_groups_longs * BITS_PER_LONG) {
157 size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long);
158
159 if (mc_groups == &mc_group_start) {
160 new_groups = kzalloc(nlen, GFP_KERNEL);
161 if (!new_groups) {
162 err = -ENOMEM;
163 goto out;
164 }
165 mc_groups = new_groups;
166 *mc_groups = mc_group_start;
167 } else {
168 new_groups = krealloc(mc_groups, nlen, GFP_KERNEL);
169 if (!new_groups) {
170 err = -ENOMEM;
171 goto out;
172 }
173 mc_groups = new_groups;
174 mc_groups[mc_groups_longs] = 0;
175 }
176 mc_groups_longs++;
177 }
178
Johannes Berg134e6372009-07-10 09:51:34 +0000179 if (family->netnsok) {
180 struct net *net;
181
Johannes Bergd136f1b2009-09-12 03:03:15 +0000182 netlink_table_grab();
Johannes Berg134e6372009-07-10 09:51:34 +0000183 rcu_read_lock();
184 for_each_net_rcu(net) {
Johannes Bergd136f1b2009-09-12 03:03:15 +0000185 err = __netlink_change_ngroups(net->genl_sock,
Johannes Berg134e6372009-07-10 09:51:34 +0000186 mc_groups_longs * BITS_PER_LONG);
187 if (err) {
188 /*
189 * No need to roll back, can only fail if
190 * memory allocation fails and then the
191 * number of _possible_ groups has been
192 * increased on some sockets which is ok.
193 */
194 rcu_read_unlock();
Johannes Bergd136f1b2009-09-12 03:03:15 +0000195 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000196 goto out;
197 }
198 }
199 rcu_read_unlock();
Johannes Bergd136f1b2009-09-12 03:03:15 +0000200 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000201 } else {
202 err = netlink_change_ngroups(init_net.genl_sock,
203 mc_groups_longs * BITS_PER_LONG);
204 if (err)
205 goto out;
206 }
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700207
208 grp->id = id;
209 set_bit(id, mc_groups);
210 list_add_tail(&grp->list, &family->mcast_groups);
211 grp->family = family;
212
213 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
214 out:
215 genl_unlock();
Thomas Graf79d310d2007-07-24 15:34:53 -0700216 return err;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700217}
218EXPORT_SYMBOL(genl_register_mc_group);
219
Thomas Graf79dc43862007-07-24 15:32:46 -0700220static void __genl_unregister_mc_group(struct genl_family *family,
221 struct genl_multicast_group *grp)
222{
Johannes Berg134e6372009-07-10 09:51:34 +0000223 struct net *net;
Thomas Graf79dc43862007-07-24 15:32:46 -0700224 BUG_ON(grp->family != family);
Johannes Berg134e6372009-07-10 09:51:34 +0000225
Johannes Bergb8273572009-09-24 15:44:05 -0700226 netlink_table_grab();
Johannes Berg134e6372009-07-10 09:51:34 +0000227 rcu_read_lock();
228 for_each_net_rcu(net)
Johannes Bergb8273572009-09-24 15:44:05 -0700229 __netlink_clear_multicast_users(net->genl_sock, grp->id);
Johannes Berg134e6372009-07-10 09:51:34 +0000230 rcu_read_unlock();
Johannes Bergb8273572009-09-24 15:44:05 -0700231 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000232
Thomas Graf79dc43862007-07-24 15:32:46 -0700233 clear_bit(grp->id, mc_groups);
234 list_del(&grp->list);
235 genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
236 grp->id = 0;
237 grp->family = NULL;
238}
239
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700240/**
241 * genl_unregister_mc_group - unregister a multicast group
242 *
243 * Unregisters the specified multicast group and notifies userspace
244 * about it. All current listeners on the group are removed.
245 *
246 * Note: It is not necessary to unregister all multicast groups before
247 * unregistering the family, unregistering the family will cause
248 * all assigned multicast groups to be unregistered automatically.
249 *
250 * @family: Generic netlink family the group belongs to.
251 * @grp: The group to unregister, must have been registered successfully
252 * previously.
253 */
254void genl_unregister_mc_group(struct genl_family *family,
255 struct genl_multicast_group *grp)
256{
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700257 genl_lock();
Thomas Graf79dc43862007-07-24 15:32:46 -0700258 __genl_unregister_mc_group(family, grp);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700259 genl_unlock();
260}
Inaky Perez-Gonzalez3efb40c2008-12-20 16:57:37 -0800261EXPORT_SYMBOL(genl_unregister_mc_group);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700262
263static void genl_unregister_mc_groups(struct genl_family *family)
264{
265 struct genl_multicast_group *grp, *tmp;
266
267 list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
Thomas Graf79dc43862007-07-24 15:32:46 -0700268 __genl_unregister_mc_group(family, grp);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700269}
270
Thomas Graf482a8522005-11-10 02:25:56 +0100271/**
272 * genl_register_ops - register generic netlink operations
273 * @family: generic netlink family
274 * @ops: operations to be registered
275 *
276 * Registers the specified operations and assigns them to the specified
277 * family. Either a doit or dumpit callback must be specified or the
278 * operation will fail. Only one operation structure per command
279 * identifier may be registered.
280 *
281 * See include/net/genetlink.h for more documenation on the operations
282 * structure.
283 *
284 * Returns 0 on success or a negative error code.
285 */
286int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
287{
288 int err = -EINVAL;
289
290 if (ops->dumpit == NULL && ops->doit == NULL)
291 goto errout;
292
293 if (genl_get_cmd(ops->cmd, family)) {
294 err = -EEXIST;
295 goto errout;
296 }
297
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800298 if (ops->dumpit)
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800299 ops->flags |= GENL_CMD_CAP_DUMP;
Jamal Hadi Salim48d4ed72006-12-06 20:06:25 -0800300 if (ops->doit)
301 ops->flags |= GENL_CMD_CAP_DO;
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800302 if (ops->policy)
303 ops->flags |= GENL_CMD_CAP_HASPOL;
304
Thomas Graf482a8522005-11-10 02:25:56 +0100305 genl_lock();
306 list_add_tail(&ops->ops_list, &family->ops_list);
307 genl_unlock();
308
309 genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
310 err = 0;
311errout:
312 return err;
313}
Changli Gao416c2f92010-07-25 20:46:01 +0000314EXPORT_SYMBOL(genl_register_ops);
Thomas Graf482a8522005-11-10 02:25:56 +0100315
316/**
317 * genl_unregister_ops - unregister generic netlink operations
318 * @family: generic netlink family
319 * @ops: operations to be unregistered
320 *
321 * Unregisters the specified operations and unassigns them from the
322 * specified family. The operation blocks until the current message
323 * processing has finished and doesn't start again until the
324 * unregister process has finished.
325 *
326 * Note: It is not necessary to unregister all operations before
327 * unregistering the family, unregistering the family will cause
328 * all assigned operations to be unregistered automatically.
329 *
330 * Returns 0 on success or a negative error code.
331 */
332int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
333{
334 struct genl_ops *rc;
335
336 genl_lock();
337 list_for_each_entry(rc, &family->ops_list, ops_list) {
338 if (rc == ops) {
339 list_del(&ops->ops_list);
340 genl_unlock();
341 genl_ctrl_event(CTRL_CMD_DELOPS, ops);
342 return 0;
343 }
344 }
345 genl_unlock();
346
347 return -ENOENT;
348}
Changli Gao416c2f92010-07-25 20:46:01 +0000349EXPORT_SYMBOL(genl_unregister_ops);
Thomas Graf482a8522005-11-10 02:25:56 +0100350
351/**
352 * genl_register_family - register a generic netlink family
353 * @family: generic netlink family
354 *
355 * Registers the specified family after validating it first. Only one
356 * family may be registered with the same family name or identifier.
357 * The family id may equal GENL_ID_GENERATE causing an unique id to
358 * be automatically generated and assigned.
359 *
360 * Return 0 on success or a negative error code.
361 */
362int genl_register_family(struct genl_family *family)
363{
364 int err = -EINVAL;
365
366 if (family->id && family->id < GENL_MIN_ID)
367 goto errout;
368
369 if (family->id > GENL_MAX_ID)
370 goto errout;
371
372 INIT_LIST_HEAD(&family->ops_list);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700373 INIT_LIST_HEAD(&family->mcast_groups);
Thomas Graf482a8522005-11-10 02:25:56 +0100374
375 genl_lock();
376
377 if (genl_family_find_byname(family->name)) {
378 err = -EEXIST;
379 goto errout_locked;
380 }
381
Thomas Graf482a8522005-11-10 02:25:56 +0100382 if (family->id == GENL_ID_GENERATE) {
383 u16 newid = genl_generate_id();
384
385 if (!newid) {
386 err = -ENOMEM;
387 goto errout_locked;
388 }
389
390 family->id = newid;
Krishna Kumar93860b02009-10-14 19:54:53 +0000391 } else if (genl_family_find_byid(family->id)) {
392 err = -EEXIST;
393 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100394 }
395
396 if (family->maxattr) {
397 family->attrbuf = kmalloc((family->maxattr+1) *
398 sizeof(struct nlattr *), GFP_KERNEL);
399 if (family->attrbuf == NULL) {
400 err = -ENOMEM;
Jamal Hadi Salime200bd82006-02-13 15:51:24 -0800401 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100402 }
403 } else
404 family->attrbuf = NULL;
405
406 list_add_tail(&family->family_list, genl_family_chain(family->id));
407 genl_unlock();
408
409 genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
410
411 return 0;
412
413errout_locked:
414 genl_unlock();
415errout:
416 return err;
417}
Changli Gao416c2f92010-07-25 20:46:01 +0000418EXPORT_SYMBOL(genl_register_family);
Thomas Graf482a8522005-11-10 02:25:56 +0100419
420/**
Michał Mirosława7b11d72009-05-21 10:34:04 +0000421 * genl_register_family_with_ops - register a generic netlink family
422 * @family: generic netlink family
423 * @ops: operations to be registered
424 * @n_ops: number of elements to register
425 *
426 * Registers the specified family and operations from the specified table.
427 * Only one family may be registered with the same family name or identifier.
428 *
429 * The family id may equal GENL_ID_GENERATE causing an unique id to
430 * be automatically generated and assigned.
431 *
432 * Either a doit or dumpit callback must be specified for every registered
433 * operation or the function will fail. Only one operation structure per
434 * command identifier may be registered.
435 *
436 * See include/net/genetlink.h for more documenation on the operations
437 * structure.
438 *
439 * This is equivalent to calling genl_register_family() followed by
440 * genl_register_ops() for every operation entry in the table taking
441 * care to unregister the family on error path.
442 *
443 * Return 0 on success or a negative error code.
444 */
445int genl_register_family_with_ops(struct genl_family *family,
446 struct genl_ops *ops, size_t n_ops)
447{
448 int err, i;
449
450 err = genl_register_family(family);
451 if (err)
452 return err;
453
454 for (i = 0; i < n_ops; ++i, ++ops) {
455 err = genl_register_ops(family, ops);
456 if (err)
457 goto err_out;
458 }
459 return 0;
460err_out:
461 genl_unregister_family(family);
462 return err;
463}
464EXPORT_SYMBOL(genl_register_family_with_ops);
465
466/**
Thomas Graf482a8522005-11-10 02:25:56 +0100467 * genl_unregister_family - unregister generic netlink family
468 * @family: generic netlink family
469 *
470 * Unregisters the specified family.
471 *
472 * Returns 0 on success or a negative error code.
473 */
474int genl_unregister_family(struct genl_family *family)
475{
476 struct genl_family *rc;
477
478 genl_lock();
479
Pavel Emelyanov910d6c32008-02-12 22:16:33 -0800480 genl_unregister_mc_groups(family);
481
Thomas Graf482a8522005-11-10 02:25:56 +0100482 list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
483 if (family->id != rc->id || strcmp(rc->name, family->name))
484 continue;
485
486 list_del(&rc->family_list);
487 INIT_LIST_HEAD(&family->ops_list);
488 genl_unlock();
489
Thomas Graf482a8522005-11-10 02:25:56 +0100490 kfree(family->attrbuf);
491 genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
492 return 0;
493 }
494
495 genl_unlock();
496
497 return -ENOENT;
498}
Changli Gao416c2f92010-07-25 20:46:01 +0000499EXPORT_SYMBOL(genl_unregister_family);
Thomas Graf482a8522005-11-10 02:25:56 +0100500
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500501/**
502 * genlmsg_put - Add generic netlink header to netlink message
503 * @skb: socket buffer holding the message
504 * @pid: netlink pid the message is addressed to
505 * @seq: sequence number (usually the one of the sender)
506 * @family: generic netlink family
Ben Hutchings2c530402012-07-10 10:55:09 +0000507 * @flags: netlink message flags
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500508 * @cmd: generic netlink command
509 *
510 * Returns pointer to user specific header
511 */
512void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
513 struct genl_family *family, int flags, u8 cmd)
514{
515 struct nlmsghdr *nlh;
516 struct genlmsghdr *hdr;
517
518 nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
519 family->hdrsize, flags);
520 if (nlh == NULL)
521 return NULL;
522
523 hdr = nlmsg_data(nlh);
524 hdr->cmd = cmd;
525 hdr->version = family->version;
526 hdr->reserved = 0;
527
528 return (char *) hdr + GENL_HDRLEN;
529}
530EXPORT_SYMBOL(genlmsg_put);
531
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700532static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
Thomas Graf482a8522005-11-10 02:25:56 +0100533{
534 struct genl_ops *ops;
535 struct genl_family *family;
Johannes Berg134e6372009-07-10 09:51:34 +0000536 struct net *net = sock_net(skb->sk);
Thomas Graf482a8522005-11-10 02:25:56 +0100537 struct genl_info info;
538 struct genlmsghdr *hdr = nlmsg_data(nlh);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700539 int hdrlen, err;
Thomas Graf482a8522005-11-10 02:25:56 +0100540
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900541 family = genl_family_find_byid(nlh->nlmsg_type);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700542 if (family == NULL)
543 return -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100544
Johannes Berg134e6372009-07-10 09:51:34 +0000545 /* this family doesn't exist in this netns */
546 if (!family->netnsok && !net_eq(net, &init_net))
547 return -ENOENT;
548
Thomas Graf482a8522005-11-10 02:25:56 +0100549 hdrlen = GENL_HDRLEN + family->hdrsize;
550 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700551 return -EINVAL;
Thomas Graf482a8522005-11-10 02:25:56 +0100552
553 ops = genl_get_cmd(hdr->cmd, family);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700554 if (ops == NULL)
555 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100556
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700557 if ((ops->flags & GENL_ADMIN_PERM) &&
Eric Parisfd778462012-01-03 12:25:16 -0500558 !capable(CAP_NET_ADMIN))
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700559 return -EPERM;
Thomas Graf482a8522005-11-10 02:25:56 +0100560
David S. Millerb8f3ab42011-01-18 12:40:38 -0800561 if (nlh->nlmsg_flags & NLM_F_DUMP) {
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700562 if (ops->dumpit == NULL)
563 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100564
Patrick McHardy6d1a3fb2008-06-18 02:07:07 -0700565 genl_unlock();
Pablo Neira Ayuso80d326f2012-02-24 14:30:15 +0000566 {
567 struct netlink_dump_control c = {
568 .dump = ops->dumpit,
569 .done = ops->done,
570 };
571 err = netlink_dump_start(net->genl_sock, skb, nlh, &c);
572 }
Patrick McHardy6d1a3fb2008-06-18 02:07:07 -0700573 genl_lock();
574 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100575 }
576
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700577 if (ops->doit == NULL)
578 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100579
580 if (family->attrbuf) {
581 err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
582 ops->policy);
583 if (err < 0)
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700584 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100585 }
586
587 info.snd_seq = nlh->nlmsg_seq;
588 info.snd_pid = NETLINK_CB(skb).pid;
589 info.nlhdr = nlh;
590 info.genlhdr = nlmsg_data(nlh);
591 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
592 info.attrs = family->attrbuf;
Johannes Berg134e6372009-07-10 09:51:34 +0000593 genl_info_net_set(&info, net);
Johannes Bergff4c92d2010-10-04 21:14:03 +0200594 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
Thomas Graf482a8522005-11-10 02:25:56 +0100595
Johannes Bergff4c92d2010-10-04 21:14:03 +0200596 if (family->pre_doit) {
597 err = family->pre_doit(ops, skb, &info);
598 if (err)
599 return err;
600 }
601
602 err = ops->doit(skb, &info);
603
604 if (family->post_doit)
605 family->post_doit(ops, skb, &info);
606
607 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100608}
609
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700610static void genl_rcv(struct sk_buff *skb)
Thomas Graf482a8522005-11-10 02:25:56 +0100611{
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700612 genl_lock();
613 netlink_rcv_skb(skb, &genl_rcv_msg);
614 genl_unlock();
Thomas Graf482a8522005-11-10 02:25:56 +0100615}
616
617/**************************************************************************
618 * Controller
619 **************************************************************************/
620
Thomas Graf17c157c2006-11-14 19:46:02 -0800621static struct genl_family genl_ctrl = {
622 .id = GENL_ID_CTRL,
623 .name = "nlctrl",
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800624 .version = 0x2,
Thomas Graf17c157c2006-11-14 19:46:02 -0800625 .maxattr = CTRL_ATTR_MAX,
Johannes Berg134e6372009-07-10 09:51:34 +0000626 .netnsok = true,
Thomas Graf17c157c2006-11-14 19:46:02 -0800627};
628
Thomas Graf482a8522005-11-10 02:25:56 +0100629static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
630 u32 flags, struct sk_buff *skb, u8 cmd)
631{
632 void *hdr;
633
Thomas Graf17c157c2006-11-14 19:46:02 -0800634 hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
Thomas Graf482a8522005-11-10 02:25:56 +0100635 if (hdr == NULL)
636 return -1;
637
David S. Miller444653f2012-03-29 23:25:11 -0400638 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
639 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
640 nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
641 nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
642 nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
643 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700644
Thomas Grafe94ef682006-11-23 11:44:37 -0800645 if (!list_empty(&family->ops_list)) {
646 struct nlattr *nla_ops;
647 struct genl_ops *ops;
648 int idx = 1;
Thomas Grafeb328112006-09-18 00:01:59 -0700649
Thomas Grafe94ef682006-11-23 11:44:37 -0800650 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
651 if (nla_ops == NULL)
Thomas Grafeb328112006-09-18 00:01:59 -0700652 goto nla_put_failure;
653
Thomas Grafe94ef682006-11-23 11:44:37 -0800654 list_for_each_entry(ops, &family->ops_list, ops_list) {
655 struct nlattr *nest;
Thomas Grafeb328112006-09-18 00:01:59 -0700656
Thomas Grafe94ef682006-11-23 11:44:37 -0800657 nest = nla_nest_start(skb, idx++);
658 if (nest == NULL)
659 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700660
David S. Miller444653f2012-03-29 23:25:11 -0400661 if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
662 nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, ops->flags))
663 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700664
Thomas Grafe94ef682006-11-23 11:44:37 -0800665 nla_nest_end(skb, nest);
666 }
667
668 nla_nest_end(skb, nla_ops);
Thomas Grafeb328112006-09-18 00:01:59 -0700669 }
670
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700671 if (!list_empty(&family->mcast_groups)) {
672 struct genl_multicast_group *grp;
673 struct nlattr *nla_grps;
674 int idx = 1;
675
676 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
677 if (nla_grps == NULL)
678 goto nla_put_failure;
679
680 list_for_each_entry(grp, &family->mcast_groups, list) {
681 struct nlattr *nest;
682
683 nest = nla_nest_start(skb, idx++);
684 if (nest == NULL)
685 goto nla_put_failure;
686
David S. Miller444653f2012-03-29 23:25:11 -0400687 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) ||
688 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
689 grp->name))
690 goto nla_put_failure;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700691
692 nla_nest_end(skb, nest);
693 }
694 nla_nest_end(skb, nla_grps);
695 }
696
697 return genlmsg_end(skb, hdr);
698
699nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700700 genlmsg_cancel(skb, hdr);
701 return -EMSGSIZE;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700702}
703
704static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
705 u32 seq, u32 flags, struct sk_buff *skb,
706 u8 cmd)
707{
708 void *hdr;
709 struct nlattr *nla_grps;
710 struct nlattr *nest;
711
712 hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
713 if (hdr == NULL)
714 return -1;
715
David S. Miller444653f2012-03-29 23:25:11 -0400716 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name) ||
717 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id))
718 goto nla_put_failure;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700719
720 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
721 if (nla_grps == NULL)
722 goto nla_put_failure;
723
724 nest = nla_nest_start(skb, 1);
725 if (nest == NULL)
726 goto nla_put_failure;
727
David S. Miller444653f2012-03-29 23:25:11 -0400728 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) ||
729 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
730 grp->name))
731 goto nla_put_failure;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700732
733 nla_nest_end(skb, nest);
734 nla_nest_end(skb, nla_grps);
735
Thomas Graf482a8522005-11-10 02:25:56 +0100736 return genlmsg_end(skb, hdr);
737
738nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700739 genlmsg_cancel(skb, hdr);
740 return -EMSGSIZE;
Thomas Graf482a8522005-11-10 02:25:56 +0100741}
742
743static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
744{
745
746 int i, n = 0;
747 struct genl_family *rt;
Johannes Berg134e6372009-07-10 09:51:34 +0000748 struct net *net = sock_net(skb->sk);
Thomas Graf482a8522005-11-10 02:25:56 +0100749 int chains_to_skip = cb->args[0];
750 int fams_to_skip = cb->args[1];
751
Samir Bellabese1d5a012010-01-07 22:10:56 +0000752 for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
Thomas Graf482a8522005-11-10 02:25:56 +0100753 n = 0;
754 list_for_each_entry(rt, genl_family_chain(i), family_list) {
Johannes Berg134e6372009-07-10 09:51:34 +0000755 if (!rt->netnsok && !net_eq(net, &init_net))
756 continue;
Thomas Graf482a8522005-11-10 02:25:56 +0100757 if (++n < fams_to_skip)
758 continue;
759 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
760 cb->nlh->nlmsg_seq, NLM_F_MULTI,
761 skb, CTRL_CMD_NEWFAMILY) < 0)
762 goto errout;
763 }
764
765 fams_to_skip = 0;
766 }
767
768errout:
769 cb->args[0] = i;
770 cb->args[1] = n;
771
772 return skb->len;
773}
774
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700775static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
776 u32 pid, int seq, u8 cmd)
Thomas Graf482a8522005-11-10 02:25:56 +0100777{
778 struct sk_buff *skb;
779 int err;
780
Thomas Graf339bf982006-11-10 14:10:15 -0800781 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
Thomas Graf482a8522005-11-10 02:25:56 +0100782 if (skb == NULL)
783 return ERR_PTR(-ENOBUFS);
784
785 err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
786 if (err < 0) {
787 nlmsg_free(skb);
788 return ERR_PTR(err);
789 }
790
791 return skb;
792}
793
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700794static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
795 u32 pid, int seq, u8 cmd)
796{
797 struct sk_buff *skb;
798 int err;
799
800 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
801 if (skb == NULL)
802 return ERR_PTR(-ENOBUFS);
803
804 err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd);
805 if (err < 0) {
806 nlmsg_free(skb);
807 return ERR_PTR(err);
808 }
809
810 return skb;
811}
812
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700813static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
Thomas Graf482a8522005-11-10 02:25:56 +0100814 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
Thomas Graf5176f912006-08-26 20:13:18 -0700815 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
816 .len = GENL_NAMSIZ - 1 },
Thomas Graf482a8522005-11-10 02:25:56 +0100817};
818
819static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
820{
821 struct sk_buff *msg;
822 struct genl_family *res = NULL;
823 int err = -EINVAL;
824
825 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
826 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
827 res = genl_family_find_byid(id);
Johannes Berg134e6372009-07-10 09:51:34 +0000828 err = -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100829 }
830
831 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
Thomas Graf5176f912006-08-26 20:13:18 -0700832 char *name;
Thomas Graf482a8522005-11-10 02:25:56 +0100833
Thomas Graf5176f912006-08-26 20:13:18 -0700834 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
Thomas Graf482a8522005-11-10 02:25:56 +0100835 res = genl_family_find_byname(name);
Stephen Hemmingerfa843092011-12-28 13:48:55 -0500836#ifdef CONFIG_MODULES
837 if (res == NULL) {
838 genl_unlock();
Neil Hormane9412c32012-05-29 09:30:41 +0000839 request_module("net-pf-%d-proto-%d-family-%s",
Stephen Hemmingerfa843092011-12-28 13:48:55 -0500840 PF_NETLINK, NETLINK_GENERIC, name);
841 genl_lock();
842 res = genl_family_find_byname(name);
843 }
844#endif
Johannes Berg134e6372009-07-10 09:51:34 +0000845 err = -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100846 }
847
Johannes Berg134e6372009-07-10 09:51:34 +0000848 if (res == NULL)
849 return err;
850
851 if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
852 /* family doesn't exist here */
853 return -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100854 }
855
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700856 msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
857 CTRL_CMD_NEWFAMILY);
Johannes Berg134e6372009-07-10 09:51:34 +0000858 if (IS_ERR(msg))
859 return PTR_ERR(msg);
Thomas Graf482a8522005-11-10 02:25:56 +0100860
Johannes Berg134e6372009-07-10 09:51:34 +0000861 return genlmsg_reply(msg, info);
Thomas Graf482a8522005-11-10 02:25:56 +0100862}
863
864static int genl_ctrl_event(int event, void *data)
865{
866 struct sk_buff *msg;
Johannes Berg134e6372009-07-10 09:51:34 +0000867 struct genl_family *family;
868 struct genl_multicast_group *grp;
Thomas Graf482a8522005-11-10 02:25:56 +0100869
Johannes Berg134e6372009-07-10 09:51:34 +0000870 /* genl is still initialising */
871 if (!init_net.genl_sock)
Thomas Graf482a8522005-11-10 02:25:56 +0100872 return 0;
873
874 switch (event) {
875 case CTRL_CMD_NEWFAMILY:
876 case CTRL_CMD_DELFAMILY:
Johannes Berg134e6372009-07-10 09:51:34 +0000877 family = data;
878 msg = ctrl_build_family_msg(family, 0, 0, event);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700879 break;
880 case CTRL_CMD_NEWMCAST_GRP:
881 case CTRL_CMD_DELMCAST_GRP:
Johannes Berg134e6372009-07-10 09:51:34 +0000882 grp = data;
883 family = grp->family;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700884 msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
Thomas Graf482a8522005-11-10 02:25:56 +0100885 break;
Johannes Berg134e6372009-07-10 09:51:34 +0000886 default:
887 return -EINVAL;
888 }
889
890 if (IS_ERR(msg))
891 return PTR_ERR(msg);
892
893 if (!family->netnsok) {
894 genlmsg_multicast_netns(&init_net, msg, 0,
895 GENL_ID_CTRL, GFP_KERNEL);
896 } else {
897 rcu_read_lock();
898 genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
899 rcu_read_unlock();
Thomas Graf482a8522005-11-10 02:25:56 +0100900 }
901
902 return 0;
903}
904
905static struct genl_ops genl_ctrl_ops = {
906 .cmd = CTRL_CMD_GETFAMILY,
907 .doit = ctrl_getfamily,
908 .dumpit = ctrl_dumpfamily,
909 .policy = ctrl_policy,
910};
911
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700912static struct genl_multicast_group notify_grp = {
913 .name = "notify",
914};
915
Johannes Berg134e6372009-07-10 09:51:34 +0000916static int __net_init genl_pernet_init(struct net *net)
917{
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +0000918 struct netlink_kernel_cfg cfg = {
919 .input = genl_rcv,
920 .cb_mutex = &genl_mutex,
921 };
922
Johannes Berg134e6372009-07-10 09:51:34 +0000923 /* we'll bump the group number right afterwards */
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +0000924 net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC,
925 THIS_MODULE, &cfg);
Johannes Berg134e6372009-07-10 09:51:34 +0000926
927 if (!net->genl_sock && net_eq(net, &init_net))
928 panic("GENL: Cannot initialize generic netlink\n");
929
930 if (!net->genl_sock)
931 return -ENOMEM;
932
933 return 0;
934}
935
936static void __net_exit genl_pernet_exit(struct net *net)
937{
938 netlink_kernel_release(net->genl_sock);
939 net->genl_sock = NULL;
940}
941
942static struct pernet_operations genl_pernet_ops = {
943 .init = genl_pernet_init,
944 .exit = genl_pernet_exit,
945};
946
Thomas Graf482a8522005-11-10 02:25:56 +0100947static int __init genl_init(void)
948{
949 int i, err;
950
951 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
952 INIT_LIST_HEAD(&family_ht[i]);
953
Changli Gao652c6712010-07-25 23:21:05 +0000954 err = genl_register_family_with_ops(&genl_ctrl, &genl_ctrl_ops, 1);
Thomas Graf482a8522005-11-10 02:25:56 +0100955 if (err < 0)
Johannes Berg134e6372009-07-10 09:51:34 +0000956 goto problem;
Thomas Graf482a8522005-11-10 02:25:56 +0100957
958 netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700959
Johannes Berg134e6372009-07-10 09:51:34 +0000960 err = register_pernet_subsys(&genl_pernet_ops);
961 if (err)
962 goto problem;
Thomas Graf482a8522005-11-10 02:25:56 +0100963
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700964 err = genl_register_mc_group(&genl_ctrl, &notify_grp);
965 if (err < 0)
Johannes Berg134e6372009-07-10 09:51:34 +0000966 goto problem;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700967
Thomas Graf482a8522005-11-10 02:25:56 +0100968 return 0;
969
Johannes Berg134e6372009-07-10 09:51:34 +0000970problem:
Thomas Graf482a8522005-11-10 02:25:56 +0100971 panic("GENL: Cannot register controller: %d\n", err);
Thomas Graf482a8522005-11-10 02:25:56 +0100972}
973
974subsys_initcall(genl_init);
975
Johannes Berg134e6372009-07-10 09:51:34 +0000976static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
977 gfp_t flags)
978{
979 struct sk_buff *tmp;
980 struct net *net, *prev = NULL;
981 int err;
982
983 for_each_net_rcu(net) {
984 if (prev) {
985 tmp = skb_clone(skb, flags);
986 if (!tmp) {
987 err = -ENOMEM;
988 goto error;
989 }
990 err = nlmsg_multicast(prev->genl_sock, tmp,
991 pid, group, flags);
992 if (err)
993 goto error;
994 }
995
996 prev = net;
997 }
998
999 return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
1000 error:
1001 kfree_skb(skb);
1002 return err;
1003}
1004
1005int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
1006 gfp_t flags)
1007{
1008 return genlmsg_mcast(skb, pid, group, flags);
1009}
1010EXPORT_SYMBOL(genlmsg_multicast_allns);
Pravin B Shelar263ba612011-11-10 19:14:37 -08001011
1012void genl_notify(struct sk_buff *skb, struct net *net, u32 pid, u32 group,
1013 struct nlmsghdr *nlh, gfp_t flags)
1014{
1015 struct sock *sk = net->genl_sock;
1016 int report = 0;
1017
1018 if (nlh)
1019 report = nlmsg_report(nlh);
1020
1021 nlmsg_notify(sk, skb, pid, group, report, flags);
1022}
1023EXPORT_SYMBOL(genl_notify);