blob: 1d3dd30099df00f2983e95de4125da6d4cd923df [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>
11#include <linux/errno.h>
12#include <linux/types.h>
13#include <linux/socket.h>
14#include <linux/string.h>
15#include <linux/skbuff.h>
Ingo Molnar14cc3e22006-03-26 01:37:14 -080016#include <linux/mutex.h>
Johannes Berg2dbba6f2007-07-18 15:47:52 -070017#include <linux/bitmap.h>
Thomas Graf482a8522005-11-10 02:25:56 +010018#include <net/sock.h>
19#include <net/genetlink.h>
20
21struct sock *genl_sock = NULL;
22
Ingo Molnar14cc3e22006-03-26 01:37:14 -080023static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
Thomas Graf482a8522005-11-10 02:25:56 +010024
Denis V. Lunev3b715352007-10-10 21:13:32 -070025static inline void genl_lock(void)
Thomas Graf482a8522005-11-10 02:25:56 +010026{
Ingo Molnar14cc3e22006-03-26 01:37:14 -080027 mutex_lock(&genl_mutex);
Thomas Graf482a8522005-11-10 02:25:56 +010028}
29
Denis V. Lunev3b715352007-10-10 21:13:32 -070030static inline void 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}
34
35#define GENL_FAM_TAB_SIZE 16
36#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
37
38static struct list_head family_ht[GENL_FAM_TAB_SIZE];
Johannes Berg2dbba6f2007-07-18 15:47:52 -070039/*
40 * Bitmap of multicast groups that are currently in use.
41 *
42 * To avoid an allocation at boot of just one unsigned long,
43 * declare it global instead.
44 * Bit 0 is marked as already used since group 0 is invalid.
45 */
46static unsigned long mc_group_start = 0x1;
47static unsigned long *mc_groups = &mc_group_start;
48static unsigned long mc_groups_longs = 1;
Thomas Graf482a8522005-11-10 02:25:56 +010049
50static int genl_ctrl_event(int event, void *data);
51
52static inline unsigned int genl_family_hash(unsigned int id)
53{
54 return id & GENL_FAM_TAB_MASK;
55}
56
57static inline struct list_head *genl_family_chain(unsigned int id)
58{
59 return &family_ht[genl_family_hash(id)];
60}
61
62static struct genl_family *genl_family_find_byid(unsigned int id)
63{
64 struct genl_family *f;
65
66 list_for_each_entry(f, genl_family_chain(id), family_list)
67 if (f->id == id)
68 return f;
69
70 return NULL;
71}
72
73static struct genl_family *genl_family_find_byname(char *name)
74{
75 struct genl_family *f;
76 int i;
77
78 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
79 list_for_each_entry(f, genl_family_chain(i), family_list)
80 if (strcmp(f->name, name) == 0)
81 return f;
82
83 return NULL;
84}
85
86static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
87{
88 struct genl_ops *ops;
89
90 list_for_each_entry(ops, &family->ops_list, ops_list)
91 if (ops->cmd == cmd)
92 return ops;
93
94 return NULL;
95}
96
97/* Of course we are going to have problems once we hit
98 * 2^16 alive types, but that can only happen by year 2K
99*/
100static inline u16 genl_generate_id(void)
101{
102 static u16 id_gen_idx;
103 int overflowed = 0;
104
105 do {
106 if (id_gen_idx == 0)
107 id_gen_idx = GENL_MIN_ID;
108
109 if (++id_gen_idx > GENL_MAX_ID) {
110 if (!overflowed) {
111 overflowed = 1;
112 id_gen_idx = 0;
113 continue;
114 } else
115 return 0;
116 }
117
118 } while (genl_family_find_byid(id_gen_idx));
119
120 return id_gen_idx;
121}
122
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700123static struct genl_multicast_group notify_grp;
124
125/**
126 * genl_register_mc_group - register a multicast group
127 *
128 * Registers the specified multicast group and notifies userspace
129 * about the new group.
130 *
131 * Returns 0 on success or a negative error code.
132 *
133 * @family: The generic netlink family the group shall be registered for.
134 * @grp: The group to register, must have a name.
135 */
136int genl_register_mc_group(struct genl_family *family,
137 struct genl_multicast_group *grp)
138{
139 int id;
140 unsigned long *new_groups;
141 int err;
142
143 BUG_ON(grp->name[0] == '\0');
144
145 genl_lock();
146
147 /* special-case our own group */
148 if (grp == &notify_grp)
149 id = GENL_ID_CTRL;
150 else
151 id = find_first_zero_bit(mc_groups,
152 mc_groups_longs * BITS_PER_LONG);
153
154
155 if (id >= mc_groups_longs * BITS_PER_LONG) {
156 size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long);
157
158 if (mc_groups == &mc_group_start) {
159 new_groups = kzalloc(nlen, GFP_KERNEL);
160 if (!new_groups) {
161 err = -ENOMEM;
162 goto out;
163 }
164 mc_groups = new_groups;
165 *mc_groups = mc_group_start;
166 } else {
167 new_groups = krealloc(mc_groups, nlen, GFP_KERNEL);
168 if (!new_groups) {
169 err = -ENOMEM;
170 goto out;
171 }
172 mc_groups = new_groups;
173 mc_groups[mc_groups_longs] = 0;
174 }
175 mc_groups_longs++;
176 }
177
178 err = netlink_change_ngroups(genl_sock,
Thomas Graf2c04ddb2007-07-24 15:33:51 -0700179 mc_groups_longs * BITS_PER_LONG);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700180 if (err)
181 goto out;
182
183 grp->id = id;
184 set_bit(id, mc_groups);
185 list_add_tail(&grp->list, &family->mcast_groups);
186 grp->family = family;
187
188 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
189 out:
190 genl_unlock();
Thomas Graf79d310d2007-07-24 15:34:53 -0700191 return err;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700192}
193EXPORT_SYMBOL(genl_register_mc_group);
194
Thomas Graf79dc43862007-07-24 15:32:46 -0700195static void __genl_unregister_mc_group(struct genl_family *family,
196 struct genl_multicast_group *grp)
197{
198 BUG_ON(grp->family != family);
199 netlink_clear_multicast_users(genl_sock, grp->id);
200 clear_bit(grp->id, mc_groups);
201 list_del(&grp->list);
202 genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
203 grp->id = 0;
204 grp->family = NULL;
205}
206
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700207/**
208 * genl_unregister_mc_group - unregister a multicast group
209 *
210 * Unregisters the specified multicast group and notifies userspace
211 * about it. All current listeners on the group are removed.
212 *
213 * Note: It is not necessary to unregister all multicast groups before
214 * unregistering the family, unregistering the family will cause
215 * all assigned multicast groups to be unregistered automatically.
216 *
217 * @family: Generic netlink family the group belongs to.
218 * @grp: The group to unregister, must have been registered successfully
219 * previously.
220 */
221void genl_unregister_mc_group(struct genl_family *family,
222 struct genl_multicast_group *grp)
223{
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700224 genl_lock();
Thomas Graf79dc43862007-07-24 15:32:46 -0700225 __genl_unregister_mc_group(family, grp);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700226 genl_unlock();
227}
Inaky Perez-Gonzalez3efb40c2008-12-20 16:57:37 -0800228EXPORT_SYMBOL(genl_unregister_mc_group);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700229
230static void genl_unregister_mc_groups(struct genl_family *family)
231{
232 struct genl_multicast_group *grp, *tmp;
233
234 list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
Thomas Graf79dc43862007-07-24 15:32:46 -0700235 __genl_unregister_mc_group(family, grp);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700236}
237
Thomas Graf482a8522005-11-10 02:25:56 +0100238/**
239 * genl_register_ops - register generic netlink operations
240 * @family: generic netlink family
241 * @ops: operations to be registered
242 *
243 * Registers the specified operations and assigns them to the specified
244 * family. Either a doit or dumpit callback must be specified or the
245 * operation will fail. Only one operation structure per command
246 * identifier may be registered.
247 *
248 * See include/net/genetlink.h for more documenation on the operations
249 * structure.
250 *
251 * Returns 0 on success or a negative error code.
252 */
253int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
254{
255 int err = -EINVAL;
256
257 if (ops->dumpit == NULL && ops->doit == NULL)
258 goto errout;
259
260 if (genl_get_cmd(ops->cmd, family)) {
261 err = -EEXIST;
262 goto errout;
263 }
264
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800265 if (ops->dumpit)
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800266 ops->flags |= GENL_CMD_CAP_DUMP;
Jamal Hadi Salim48d4ed72006-12-06 20:06:25 -0800267 if (ops->doit)
268 ops->flags |= GENL_CMD_CAP_DO;
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800269 if (ops->policy)
270 ops->flags |= GENL_CMD_CAP_HASPOL;
271
Thomas Graf482a8522005-11-10 02:25:56 +0100272 genl_lock();
273 list_add_tail(&ops->ops_list, &family->ops_list);
274 genl_unlock();
275
276 genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
277 err = 0;
278errout:
279 return err;
280}
281
282/**
283 * genl_unregister_ops - unregister generic netlink operations
284 * @family: generic netlink family
285 * @ops: operations to be unregistered
286 *
287 * Unregisters the specified operations and unassigns them from the
288 * specified family. The operation blocks until the current message
289 * processing has finished and doesn't start again until the
290 * unregister process has finished.
291 *
292 * Note: It is not necessary to unregister all operations before
293 * unregistering the family, unregistering the family will cause
294 * all assigned operations to be unregistered automatically.
295 *
296 * Returns 0 on success or a negative error code.
297 */
298int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
299{
300 struct genl_ops *rc;
301
302 genl_lock();
303 list_for_each_entry(rc, &family->ops_list, ops_list) {
304 if (rc == ops) {
305 list_del(&ops->ops_list);
306 genl_unlock();
307 genl_ctrl_event(CTRL_CMD_DELOPS, ops);
308 return 0;
309 }
310 }
311 genl_unlock();
312
313 return -ENOENT;
314}
315
316/**
317 * genl_register_family - register a generic netlink family
318 * @family: generic netlink family
319 *
320 * Registers the specified family after validating it first. Only one
321 * family may be registered with the same family name or identifier.
322 * The family id may equal GENL_ID_GENERATE causing an unique id to
323 * be automatically generated and assigned.
324 *
325 * Return 0 on success or a negative error code.
326 */
327int genl_register_family(struct genl_family *family)
328{
329 int err = -EINVAL;
330
331 if (family->id && family->id < GENL_MIN_ID)
332 goto errout;
333
334 if (family->id > GENL_MAX_ID)
335 goto errout;
336
337 INIT_LIST_HEAD(&family->ops_list);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700338 INIT_LIST_HEAD(&family->mcast_groups);
Thomas Graf482a8522005-11-10 02:25:56 +0100339
340 genl_lock();
341
342 if (genl_family_find_byname(family->name)) {
343 err = -EEXIST;
344 goto errout_locked;
345 }
346
347 if (genl_family_find_byid(family->id)) {
348 err = -EEXIST;
349 goto errout_locked;
350 }
351
Thomas Graf482a8522005-11-10 02:25:56 +0100352 if (family->id == GENL_ID_GENERATE) {
353 u16 newid = genl_generate_id();
354
355 if (!newid) {
356 err = -ENOMEM;
357 goto errout_locked;
358 }
359
360 family->id = newid;
361 }
362
363 if (family->maxattr) {
364 family->attrbuf = kmalloc((family->maxattr+1) *
365 sizeof(struct nlattr *), GFP_KERNEL);
366 if (family->attrbuf == NULL) {
367 err = -ENOMEM;
Jamal Hadi Salime200bd82006-02-13 15:51:24 -0800368 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100369 }
370 } else
371 family->attrbuf = NULL;
372
373 list_add_tail(&family->family_list, genl_family_chain(family->id));
374 genl_unlock();
375
376 genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
377
378 return 0;
379
380errout_locked:
381 genl_unlock();
382errout:
383 return err;
384}
385
386/**
387 * genl_unregister_family - unregister generic netlink family
388 * @family: generic netlink family
389 *
390 * Unregisters the specified family.
391 *
392 * Returns 0 on success or a negative error code.
393 */
394int genl_unregister_family(struct genl_family *family)
395{
396 struct genl_family *rc;
397
398 genl_lock();
399
Pavel Emelyanov910d6c32008-02-12 22:16:33 -0800400 genl_unregister_mc_groups(family);
401
Thomas Graf482a8522005-11-10 02:25:56 +0100402 list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
403 if (family->id != rc->id || strcmp(rc->name, family->name))
404 continue;
405
406 list_del(&rc->family_list);
407 INIT_LIST_HEAD(&family->ops_list);
408 genl_unlock();
409
Thomas Graf482a8522005-11-10 02:25:56 +0100410 kfree(family->attrbuf);
411 genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
412 return 0;
413 }
414
415 genl_unlock();
416
417 return -ENOENT;
418}
419
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700420static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
Thomas Graf482a8522005-11-10 02:25:56 +0100421{
422 struct genl_ops *ops;
423 struct genl_family *family;
424 struct genl_info info;
425 struct genlmsghdr *hdr = nlmsg_data(nlh);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700426 int hdrlen, err;
Thomas Graf482a8522005-11-10 02:25:56 +0100427
YOSHIFUJI Hideaki746fac42007-02-09 23:25:07 +0900428 family = genl_family_find_byid(nlh->nlmsg_type);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700429 if (family == NULL)
430 return -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100431
432 hdrlen = GENL_HDRLEN + family->hdrsize;
433 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700434 return -EINVAL;
Thomas Graf482a8522005-11-10 02:25:56 +0100435
436 ops = genl_get_cmd(hdr->cmd, family);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700437 if (ops == NULL)
438 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100439
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700440 if ((ops->flags & GENL_ADMIN_PERM) &&
441 security_netlink_recv(skb, CAP_NET_ADMIN))
442 return -EPERM;
Thomas Graf482a8522005-11-10 02:25:56 +0100443
444 if (nlh->nlmsg_flags & NLM_F_DUMP) {
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700445 if (ops->dumpit == NULL)
446 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100447
Patrick McHardy6d1a3fb2008-06-18 02:07:07 -0700448 genl_unlock();
449 err = netlink_dump_start(genl_sock, skb, nlh,
450 ops->dumpit, ops->done);
451 genl_lock();
452 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100453 }
454
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700455 if (ops->doit == NULL)
456 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100457
458 if (family->attrbuf) {
459 err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
460 ops->policy);
461 if (err < 0)
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700462 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100463 }
464
465 info.snd_seq = nlh->nlmsg_seq;
466 info.snd_pid = NETLINK_CB(skb).pid;
467 info.nlhdr = nlh;
468 info.genlhdr = nlmsg_data(nlh);
469 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
470 info.attrs = family->attrbuf;
471
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700472 return ops->doit(skb, &info);
Thomas Graf482a8522005-11-10 02:25:56 +0100473}
474
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700475static void genl_rcv(struct sk_buff *skb)
Thomas Graf482a8522005-11-10 02:25:56 +0100476{
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700477 genl_lock();
478 netlink_rcv_skb(skb, &genl_rcv_msg);
479 genl_unlock();
Thomas Graf482a8522005-11-10 02:25:56 +0100480}
481
482/**************************************************************************
483 * Controller
484 **************************************************************************/
485
Thomas Graf17c157c2006-11-14 19:46:02 -0800486static struct genl_family genl_ctrl = {
487 .id = GENL_ID_CTRL,
488 .name = "nlctrl",
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800489 .version = 0x2,
Thomas Graf17c157c2006-11-14 19:46:02 -0800490 .maxattr = CTRL_ATTR_MAX,
491};
492
Thomas Graf482a8522005-11-10 02:25:56 +0100493static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
494 u32 flags, struct sk_buff *skb, u8 cmd)
495{
496 void *hdr;
497
Thomas Graf17c157c2006-11-14 19:46:02 -0800498 hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
Thomas Graf482a8522005-11-10 02:25:56 +0100499 if (hdr == NULL)
500 return -1;
501
502 NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name);
503 NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id);
Thomas Grafeb328112006-09-18 00:01:59 -0700504 NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version);
505 NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize);
506 NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr);
507
Thomas Grafe94ef682006-11-23 11:44:37 -0800508 if (!list_empty(&family->ops_list)) {
509 struct nlattr *nla_ops;
510 struct genl_ops *ops;
511 int idx = 1;
Thomas Grafeb328112006-09-18 00:01:59 -0700512
Thomas Grafe94ef682006-11-23 11:44:37 -0800513 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
514 if (nla_ops == NULL)
Thomas Grafeb328112006-09-18 00:01:59 -0700515 goto nla_put_failure;
516
Thomas Grafe94ef682006-11-23 11:44:37 -0800517 list_for_each_entry(ops, &family->ops_list, ops_list) {
518 struct nlattr *nest;
Thomas Grafeb328112006-09-18 00:01:59 -0700519
Thomas Grafe94ef682006-11-23 11:44:37 -0800520 nest = nla_nest_start(skb, idx++);
521 if (nest == NULL)
522 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700523
Thomas Grafe94ef682006-11-23 11:44:37 -0800524 NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
525 NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
Thomas Grafeb328112006-09-18 00:01:59 -0700526
Thomas Grafe94ef682006-11-23 11:44:37 -0800527 nla_nest_end(skb, nest);
528 }
529
530 nla_nest_end(skb, nla_ops);
Thomas Grafeb328112006-09-18 00:01:59 -0700531 }
532
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700533 if (!list_empty(&family->mcast_groups)) {
534 struct genl_multicast_group *grp;
535 struct nlattr *nla_grps;
536 int idx = 1;
537
538 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
539 if (nla_grps == NULL)
540 goto nla_put_failure;
541
542 list_for_each_entry(grp, &family->mcast_groups, list) {
543 struct nlattr *nest;
544
545 nest = nla_nest_start(skb, idx++);
546 if (nest == NULL)
547 goto nla_put_failure;
548
549 NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
550 NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
551 grp->name);
552
553 nla_nest_end(skb, nest);
554 }
555 nla_nest_end(skb, nla_grps);
556 }
557
558 return genlmsg_end(skb, hdr);
559
560nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700561 genlmsg_cancel(skb, hdr);
562 return -EMSGSIZE;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700563}
564
565static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
566 u32 seq, u32 flags, struct sk_buff *skb,
567 u8 cmd)
568{
569 void *hdr;
570 struct nlattr *nla_grps;
571 struct nlattr *nest;
572
573 hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
574 if (hdr == NULL)
575 return -1;
576
577 NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name);
578 NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id);
579
580 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
581 if (nla_grps == NULL)
582 goto nla_put_failure;
583
584 nest = nla_nest_start(skb, 1);
585 if (nest == NULL)
586 goto nla_put_failure;
587
588 NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
589 NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
590 grp->name);
591
592 nla_nest_end(skb, nest);
593 nla_nest_end(skb, nla_grps);
594
Thomas Graf482a8522005-11-10 02:25:56 +0100595 return genlmsg_end(skb, hdr);
596
597nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700598 genlmsg_cancel(skb, hdr);
599 return -EMSGSIZE;
Thomas Graf482a8522005-11-10 02:25:56 +0100600}
601
602static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
603{
604
605 int i, n = 0;
606 struct genl_family *rt;
607 int chains_to_skip = cb->args[0];
608 int fams_to_skip = cb->args[1];
609
610 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
611 if (i < chains_to_skip)
612 continue;
613 n = 0;
614 list_for_each_entry(rt, genl_family_chain(i), family_list) {
615 if (++n < fams_to_skip)
616 continue;
617 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
618 cb->nlh->nlmsg_seq, NLM_F_MULTI,
619 skb, CTRL_CMD_NEWFAMILY) < 0)
620 goto errout;
621 }
622
623 fams_to_skip = 0;
624 }
625
626errout:
627 cb->args[0] = i;
628 cb->args[1] = n;
629
630 return skb->len;
631}
632
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700633static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
634 u32 pid, int seq, u8 cmd)
Thomas Graf482a8522005-11-10 02:25:56 +0100635{
636 struct sk_buff *skb;
637 int err;
638
Thomas Graf339bf982006-11-10 14:10:15 -0800639 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
Thomas Graf482a8522005-11-10 02:25:56 +0100640 if (skb == NULL)
641 return ERR_PTR(-ENOBUFS);
642
643 err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
644 if (err < 0) {
645 nlmsg_free(skb);
646 return ERR_PTR(err);
647 }
648
649 return skb;
650}
651
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700652static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
653 u32 pid, int seq, u8 cmd)
654{
655 struct sk_buff *skb;
656 int err;
657
658 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
659 if (skb == NULL)
660 return ERR_PTR(-ENOBUFS);
661
662 err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd);
663 if (err < 0) {
664 nlmsg_free(skb);
665 return ERR_PTR(err);
666 }
667
668 return skb;
669}
670
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700671static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
Thomas Graf482a8522005-11-10 02:25:56 +0100672 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
Thomas Graf5176f912006-08-26 20:13:18 -0700673 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
674 .len = GENL_NAMSIZ - 1 },
Thomas Graf482a8522005-11-10 02:25:56 +0100675};
676
677static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
678{
679 struct sk_buff *msg;
680 struct genl_family *res = NULL;
681 int err = -EINVAL;
682
683 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
684 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
685 res = genl_family_find_byid(id);
686 }
687
688 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
Thomas Graf5176f912006-08-26 20:13:18 -0700689 char *name;
Thomas Graf482a8522005-11-10 02:25:56 +0100690
Thomas Graf5176f912006-08-26 20:13:18 -0700691 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
Thomas Graf482a8522005-11-10 02:25:56 +0100692 res = genl_family_find_byname(name);
693 }
694
695 if (res == NULL) {
696 err = -ENOENT;
697 goto errout;
698 }
699
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700700 msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
701 CTRL_CMD_NEWFAMILY);
Thomas Graf482a8522005-11-10 02:25:56 +0100702 if (IS_ERR(msg)) {
703 err = PTR_ERR(msg);
704 goto errout;
705 }
706
Thomas Graf81878d22006-11-14 19:45:27 -0800707 err = genlmsg_reply(msg, info);
Thomas Graf482a8522005-11-10 02:25:56 +0100708errout:
709 return err;
710}
711
712static int genl_ctrl_event(int event, void *data)
713{
714 struct sk_buff *msg;
715
716 if (genl_sock == NULL)
717 return 0;
718
719 switch (event) {
720 case CTRL_CMD_NEWFAMILY:
721 case CTRL_CMD_DELFAMILY:
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700722 msg = ctrl_build_family_msg(data, 0, 0, event);
723 if (IS_ERR(msg))
724 return PTR_ERR(msg);
725
726 genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
727 break;
728 case CTRL_CMD_NEWMCAST_GRP:
729 case CTRL_CMD_DELMCAST_GRP:
730 msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
Thomas Graf482a8522005-11-10 02:25:56 +0100731 if (IS_ERR(msg))
732 return PTR_ERR(msg);
733
Thomas Grafd387f6a2006-08-15 00:31:06 -0700734 genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
Thomas Graf482a8522005-11-10 02:25:56 +0100735 break;
736 }
737
738 return 0;
739}
740
741static struct genl_ops genl_ctrl_ops = {
742 .cmd = CTRL_CMD_GETFAMILY,
743 .doit = ctrl_getfamily,
744 .dumpit = ctrl_dumpfamily,
745 .policy = ctrl_policy,
746};
747
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700748static struct genl_multicast_group notify_grp = {
749 .name = "notify",
750};
751
Thomas Graf482a8522005-11-10 02:25:56 +0100752static int __init genl_init(void)
753{
754 int i, err;
755
756 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
757 INIT_LIST_HEAD(&family_ht[i]);
758
759 err = genl_register_family(&genl_ctrl);
760 if (err < 0)
761 goto errout;
762
763 err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
764 if (err < 0)
765 goto errout_register;
766
767 netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700768
769 /* we'll bump the group number right afterwards */
Eric W. Biedermanb4b51022007-09-12 13:05:38 +0200770 genl_sock = netlink_kernel_create(&init_net, NETLINK_GENERIC, 0,
Patrick McHardy6d1a3fb2008-06-18 02:07:07 -0700771 genl_rcv, &genl_mutex, THIS_MODULE);
Jamal Hadi Salime200bd82006-02-13 15:51:24 -0800772 if (genl_sock == NULL)
Thomas Graf482a8522005-11-10 02:25:56 +0100773 panic("GENL: Cannot initialize generic netlink\n");
Thomas Graf482a8522005-11-10 02:25:56 +0100774
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700775 err = genl_register_mc_group(&genl_ctrl, &notify_grp);
776 if (err < 0)
777 goto errout_register;
778
Thomas Graf482a8522005-11-10 02:25:56 +0100779 return 0;
780
781errout_register:
782 genl_unregister_family(&genl_ctrl);
783errout:
784 panic("GENL: Cannot register controller: %d\n", err);
Thomas Graf482a8522005-11-10 02:25:56 +0100785}
786
787subsys_initcall(genl_init);
788
789EXPORT_SYMBOL(genl_sock);
790EXPORT_SYMBOL(genl_register_ops);
791EXPORT_SYMBOL(genl_unregister_ops);
792EXPORT_SYMBOL(genl_register_family);
793EXPORT_SYMBOL(genl_unregister_family);