?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
i2c: brcmstb: Fix START and STOP conditions
[linux/fpc-iii.git] / net / netlink / genetlink.c
blob49c28e8ef01b986c068ecc8e86d4d8546088c8f7
1 /*
2 * NETLINK Generic Netlink Family
3 *
4 * Authors: Jamal Hadi Salim
5 * Thomas Graf <tgraf@suug.ch>
6 * Johannes Berg <johannes@sipsolutions.net>
7 */
8
9 #include <linux/module.h>
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/errno.h>
13 #include <linux/types.h>
14 #include <linux/socket.h>
15 #include <linux/string.h>
16 #include <linux/skbuff.h>
17 #include <linux/mutex.h>
18 #include <linux/bitmap.h>
19 #include <linux/rwsem.h>
20 #include <net/sock.h>
21 #include <net/genetlink.h>
22
23 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
24 static DECLARE_RWSEM(cb_lock);
25
26 atomic_t genl_sk_destructing_cnt = ATOMIC_INIT(0);
27 DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq);
28
29 void genl_lock(void)
30 {
31 mutex_lock(&genl_mutex);
32 }
33 EXPORT_SYMBOL(genl_lock);
34
35 void genl_unlock(void)
36 {
37 mutex_unlock(&genl_mutex);
38 }
39 EXPORT_SYMBOL(genl_unlock);
40
41 #ifdef CONFIG_LOCKDEP
42 bool lockdep_genl_is_held(void)
43 {
44 return lockdep_is_held(&genl_mutex);
45 }
46 EXPORT_SYMBOL(lockdep_genl_is_held);
47 #endif
48
49 static void genl_lock_all(void)
50 {
51 down_write(&cb_lock);
52 genl_lock();
53 }
54
55 static void genl_unlock_all(void)
56 {
57 genl_unlock();
58 up_write(&cb_lock);
59 }
60
61 #define GENL_FAM_TAB_SIZE 16
62 #define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
63
64 static struct list_head family_ht[GENL_FAM_TAB_SIZE];
65 /*
66 * Bitmap of multicast groups that are currently in use.
67 *
68 * To avoid an allocation at boot of just one unsigned long,
69 * declare it global instead.
70 * Bit 0 is marked as already used since group 0 is invalid.
71 * Bit 1 is marked as already used since the drop-monitor code
72 * abuses the API and thinks it can statically use group 1.
73 * That group will typically conflict with other groups that
74 * any proper users use.
75 * Bit 16 is marked as used since it's used for generic netlink
76 * and the code no longer marks pre-reserved IDs as used.
77 * Bit 17 is marked as already used since the VFS quota code
78 * also abused this API and relied on family == group ID, we
79 * cater to that by giving it a static family and group ID.
80 * Bit 18 is marked as already used since the PMCRAID driver
81 * did the same thing as the VFS quota code (maybe copied?)
82 */
83 static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
84 BIT(GENL_ID_VFS_DQUOT) |
85 BIT(GENL_ID_PMCRAID);
86 static unsigned long *mc_groups = &mc_group_start;
87 static unsigned long mc_groups_longs = 1;
88
89 static int genl_ctrl_event(int event, struct genl_family *family,
90 const struct genl_multicast_group *grp,
91 int grp_id);
92
93 static inline unsigned int genl_family_hash(unsigned int id)
94 {
95 return id & GENL_FAM_TAB_MASK;
96 }
97
98 static inline struct list_head *genl_family_chain(unsigned int id)
99 {
100 return &family_ht[genl_family_hash(id)];
101 }
102
103 static struct genl_family *genl_family_find_byid(unsigned int id)
104 {
105 struct genl_family *f;
106
107 list_for_each_entry(f, genl_family_chain(id), family_list)
108 if (f->id == id)
109 return f;
110
111 return NULL;
112 }
113
114 static struct genl_family *genl_family_find_byname(char *name)
115 {
116 struct genl_family *f;
117 int i;
118
119 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
120 list_for_each_entry(f, genl_family_chain(i), family_list)
121 if (strcmp(f->name, name) == 0)
122 return f;
123
124 return NULL;
125 }
126
127 static const struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
128 {
129 int i;
130
131 for (i = 0; i < family->n_ops; i++)
132 if (family->ops[i].cmd == cmd)
133 return &family->ops[i];
134
135 return NULL;
136 }
137
138 /* Of course we are going to have problems once we hit
139 * 2^16 alive types, but that can only happen by year 2K
140 */
141 static u16 genl_generate_id(void)
142 {
143 static u16 id_gen_idx = GENL_MIN_ID;
144 int i;
145
146 for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
147 if (id_gen_idx != GENL_ID_VFS_DQUOT &&
148 id_gen_idx != GENL_ID_PMCRAID &&
149 !genl_family_find_byid(id_gen_idx))
150 return id_gen_idx;
151 if (++id_gen_idx > GENL_MAX_ID)
152 id_gen_idx = GENL_MIN_ID;
153 }
154
155 return 0;
156 }
157
158 static int genl_allocate_reserve_groups(int n_groups, int *first_id)
159 {
160 unsigned long *new_groups;
161 int start = 0;
162 int i;
163 int id;
164 bool fits;
165
166 do {
167 if (start == 0)
168 id = find_first_zero_bit(mc_groups,
169 mc_groups_longs *
170 BITS_PER_LONG);
171 else
172 id = find_next_zero_bit(mc_groups,
173 mc_groups_longs * BITS_PER_LONG,
174 start);
175
176 fits = true;
177 for (i = id;
178 i < min_t(int, id + n_groups,
179 mc_groups_longs * BITS_PER_LONG);
180 i++) {
181 if (test_bit(i, mc_groups)) {
182 start = i;
183 fits = false;
184 break;
185 }
186 }
187
188 if (id + n_groups > mc_groups_longs * BITS_PER_LONG) {
189 unsigned long new_longs = mc_groups_longs +
190 BITS_TO_LONGS(n_groups);
191 size_t nlen = new_longs * sizeof(unsigned long);
192
193 if (mc_groups == &mc_group_start) {
194 new_groups = kzalloc(nlen, GFP_KERNEL);
195 if (!new_groups)
196 return -ENOMEM;
197 mc_groups = new_groups;
198 *mc_groups = mc_group_start;
199 } else {
200 new_groups = krealloc(mc_groups, nlen,
201 GFP_KERNEL);
202 if (!new_groups)
203 return -ENOMEM;
204 mc_groups = new_groups;
205 for (i = 0; i < BITS_TO_LONGS(n_groups); i++)
206 mc_groups[mc_groups_longs + i] = 0;
207 }
208 mc_groups_longs = new_longs;
209 }
210 } while (!fits);
211
212 for (i = id; i < id + n_groups; i++)
213 set_bit(i, mc_groups);
214 *first_id = id;
215 return 0;
216 }
217
218 static struct genl_family genl_ctrl;
219
220 static int genl_validate_assign_mc_groups(struct genl_family *family)
221 {
222 int first_id;
223 int n_groups = family->n_mcgrps;
224 int err = 0, i;
225 bool groups_allocated = false;
226
227 if (!n_groups)
228 return 0;
229
230 for (i = 0; i < n_groups; i++) {
231 const struct genl_multicast_group *grp = &family->mcgrps[i];
232
233 if (WARN_ON(grp->name[0] == '\0'))
234 return -EINVAL;
235 if (WARN_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL))
236 return -EINVAL;
237 }
238
239 /* special-case our own group and hacks */
240 if (family == &genl_ctrl) {
241 first_id = GENL_ID_CTRL;
242 BUG_ON(n_groups != 1);
243 } else if (strcmp(family->name, "NET_DM") == 0) {
244 first_id = 1;
245 BUG_ON(n_groups != 1);
246 } else if (family->id == GENL_ID_VFS_DQUOT) {
247 first_id = GENL_ID_VFS_DQUOT;
248 BUG_ON(n_groups != 1);
249 } else if (family->id == GENL_ID_PMCRAID) {
250 first_id = GENL_ID_PMCRAID;
251 BUG_ON(n_groups != 1);
252 } else {
253 groups_allocated = true;
254 err = genl_allocate_reserve_groups(n_groups, &first_id);
255 if (err)
256 return err;
257 }
258
259 family->mcgrp_offset = first_id;
260
261 /* if still initializing, can't and don't need to to realloc bitmaps */
262 if (!init_net.genl_sock)
263 return 0;
264
265 if (family->netnsok) {
266 struct net *net;
267
268 netlink_table_grab();
269 rcu_read_lock();
270 for_each_net_rcu(net) {
271 err = __netlink_change_ngroups(net->genl_sock,
272 mc_groups_longs * BITS_PER_LONG);
273 if (err) {
274 /*
275 * No need to roll back, can only fail if
276 * memory allocation fails and then the
277 * number of _possible_ groups has been
278 * increased on some sockets which is ok.
279 */
280 break;
281 }
282 }
283 rcu_read_unlock();
284 netlink_table_ungrab();
285 } else {
286 err = netlink_change_ngroups(init_net.genl_sock,
287 mc_groups_longs * BITS_PER_LONG);
288 }
289
290 if (groups_allocated && err) {
291 for (i = 0; i < family->n_mcgrps; i++)
292 clear_bit(family->mcgrp_offset + i, mc_groups);
293 }
294
295 return err;
296 }
297
298 static void genl_unregister_mc_groups(struct genl_family *family)
299 {
300 struct net *net;
301 int i;
302
303 netlink_table_grab();
304 rcu_read_lock();
305 for_each_net_rcu(net) {
306 for (i = 0; i < family->n_mcgrps; i++)
307 __netlink_clear_multicast_users(
308 net->genl_sock, family->mcgrp_offset + i);
309 }
310 rcu_read_unlock();
311 netlink_table_ungrab();
312
313 for (i = 0; i < family->n_mcgrps; i++) {
314 int grp_id = family->mcgrp_offset + i;
315
316 if (grp_id != 1)
317 clear_bit(grp_id, mc_groups);
318 genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family,
319 &family->mcgrps[i], grp_id);
320 }
321 }
322
323 static int genl_validate_ops(const struct genl_family *family)
324 {
325 const struct genl_ops *ops = family->ops;
326 unsigned int n_ops = family->n_ops;
327 int i, j;
328
329 if (WARN_ON(n_ops && !ops))
330 return -EINVAL;
331
332 if (!n_ops)
333 return 0;
334
335 for (i = 0; i < n_ops; i++) {
336 if (ops[i].dumpit == NULL && ops[i].doit == NULL)
337 return -EINVAL;
338 for (j = i + 1; j < n_ops; j++)
339 if (ops[i].cmd == ops[j].cmd)
340 return -EINVAL;
341 }
342
343 return 0;
344 }
345
346 /**
347 * __genl_register_family - register a generic netlink family
348 * @family: generic netlink family
349 *
350 * Registers the specified family after validating it first. Only one
351 * family may be registered with the same family name or identifier.
352 * The family id may equal GENL_ID_GENERATE causing an unique id to
353 * be automatically generated and assigned.
354 *
355 * The family's ops array must already be assigned, you can use the
356 * genl_register_family_with_ops() helper function.
357 *
358 * Return 0 on success or a negative error code.
359 */
360 int __genl_register_family(struct genl_family *family)
361 {
362 int err = -EINVAL, i;
363
364 if (family->id && family->id < GENL_MIN_ID)
365 goto errout;
366
367 if (family->id > GENL_MAX_ID)
368 goto errout;
369
370 err = genl_validate_ops(family);
371 if (err)
372 return err;
373
374 genl_lock_all();
375
376 if (genl_family_find_byname(family->name)) {
377 err = -EEXIST;
378 goto errout_locked;
379 }
380
381 if (family->id == GENL_ID_GENERATE) {
382 u16 newid = genl_generate_id();
383
384 if (!newid) {
385 err = -ENOMEM;
386 goto errout_locked;
387 }
388
389 family->id = newid;
390 } else if (genl_family_find_byid(family->id)) {
391 err = -EEXIST;
392 goto errout_locked;
393 }
394
395 if (family->maxattr && !family->parallel_ops) {
396 family->attrbuf = kmalloc((family->maxattr+1) *
397 sizeof(struct nlattr *), GFP_KERNEL);
398 if (family->attrbuf == NULL) {
399 err = -ENOMEM;
400 goto errout_locked;
401 }
402 } else
403 family->attrbuf = NULL;
404
405 err = genl_validate_assign_mc_groups(family);
406 if (err)
407 goto errout_free;
408
409 list_add_tail(&family->family_list, genl_family_chain(family->id));
410 genl_unlock_all();
411
412 /* send all events */
413 genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
414 for (i = 0; i < family->n_mcgrps; i++)
415 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
416 &family->mcgrps[i], family->mcgrp_offset + i);
417
418 return 0;
419
420 errout_free:
421 kfree(family->attrbuf);
422 errout_locked:
423 genl_unlock_all();
424 errout:
425 return err;
426 }
427 EXPORT_SYMBOL(__genl_register_family);
428
429 /**
430 * genl_unregister_family - unregister generic netlink family
431 * @family: generic netlink family
432 *
433 * Unregisters the specified family.
434 *
435 * Returns 0 on success or a negative error code.
436 */
437 int genl_unregister_family(struct genl_family *family)
438 {
439 struct genl_family *rc;
440
441 genl_lock_all();
442
443 list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
444 if (family->id != rc->id || strcmp(rc->name, family->name))
445 continue;
446
447 genl_unregister_mc_groups(family);
448
449 list_del(&rc->family_list);
450 family->n_ops = 0;
451 up_write(&cb_lock);
452 wait_event(genl_sk_destructing_waitq,
453 atomic_read(&genl_sk_destructing_cnt) == 0);
454 genl_unlock();
455
456 kfree(family->attrbuf);
457 genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
458 return 0;
459 }
460
461 genl_unlock_all();
462
463 return -ENOENT;
464 }
465 EXPORT_SYMBOL(genl_unregister_family);
466
467 /**
468 * genlmsg_put - Add generic netlink header to netlink message
469 * @skb: socket buffer holding the message
470 * @portid: netlink portid the message is addressed to
471 * @seq: sequence number (usually the one of the sender)
472 * @family: generic netlink family
473 * @flags: netlink message flags
474 * @cmd: generic netlink command
475 *
476 * Returns pointer to user specific header
477 */
478 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
479 struct genl_family *family, int flags, u8 cmd)
480 {
481 struct nlmsghdr *nlh;
482 struct genlmsghdr *hdr;
483
484 nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
485 family->hdrsize, flags);
486 if (nlh == NULL)
487 return NULL;
488
489 hdr = nlmsg_data(nlh);
490 hdr->cmd = cmd;
491 hdr->version = family->version;
492 hdr->reserved = 0;
493
494 return (char *) hdr + GENL_HDRLEN;
495 }
496 EXPORT_SYMBOL(genlmsg_put);
497
498 static int genl_lock_start(struct netlink_callback *cb)
499 {
500 /* our ops are always const - netlink API doesn't propagate that */
501 const struct genl_ops *ops = cb->data;
502 int rc = 0;
503
504 if (ops->start) {
505 genl_lock();
506 rc = ops->start(cb);
507 genl_unlock();
508 }
509 return rc;
510 }
511
512 static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
513 {
514 /* our ops are always const - netlink API doesn't propagate that */
515 const struct genl_ops *ops = cb->data;
516 int rc;
517
518 genl_lock();
519 rc = ops->dumpit(skb, cb);
520 genl_unlock();
521 return rc;
522 }
523
524 static int genl_lock_done(struct netlink_callback *cb)
525 {
526 /* our ops are always const - netlink API doesn't propagate that */
527 const struct genl_ops *ops = cb->data;
528 int rc = 0;
529
530 if (ops->done) {
531 genl_lock();
532 rc = ops->done(cb);
533 genl_unlock();
534 }
535 return rc;
536 }
537
538 static int genl_family_rcv_msg(struct genl_family *family,
539 struct sk_buff *skb,
540 struct nlmsghdr *nlh)
541 {
542 const struct genl_ops *ops;
543 struct net *net = sock_net(skb->sk);
544 struct genl_info info;
545 struct genlmsghdr *hdr = nlmsg_data(nlh);
546 struct nlattr **attrbuf;
547 int hdrlen, err;
548
549 /* this family doesn't exist in this netns */
550 if (!family->netnsok && !net_eq(net, &init_net))
551 return -ENOENT;
552
553 hdrlen = GENL_HDRLEN + family->hdrsize;
554 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
555 return -EINVAL;
556
557 ops = genl_get_cmd(hdr->cmd, family);
558 if (ops == NULL)
559 return -EOPNOTSUPP;
560
561 if ((ops->flags & GENL_ADMIN_PERM) &&
562 !netlink_capable(skb, CAP_NET_ADMIN))
563 return -EPERM;
564
565 if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
566 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
567 return -EPERM;
568
569 if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
570 int rc;
571
572 if (ops->dumpit == NULL)
573 return -EOPNOTSUPP;
574
575 if (!family->parallel_ops) {
576 struct netlink_dump_control c = {
577 .module = family->module,
578 /* we have const, but the netlink API doesn't */
579 .data = (void *)ops,
580 .start = genl_lock_start,
581 .dump = genl_lock_dumpit,
582 .done = genl_lock_done,
583 };
584
585 genl_unlock();
586 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
587 genl_lock();
588
589 } else {
590 struct netlink_dump_control c = {
591 .module = family->module,
592 .start = ops->start,
593 .dump = ops->dumpit,
594 .done = ops->done,
595 };
596
597 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
598 }
599
600 return rc;
601 }
602
603 if (ops->doit == NULL)
604 return -EOPNOTSUPP;
605
606 if (family->maxattr && family->parallel_ops) {
607 attrbuf = kmalloc((family->maxattr+1) *
608 sizeof(struct nlattr *), GFP_KERNEL);
609 if (attrbuf == NULL)
610 return -ENOMEM;
611 } else
612 attrbuf = family->attrbuf;
613
614 if (attrbuf) {
615 err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
616 ops->policy);
617 if (err < 0)
618 goto out;
619 }
620
621 info.snd_seq = nlh->nlmsg_seq;
622 info.snd_portid = NETLINK_CB(skb).portid;
623 info.nlhdr = nlh;
624 info.genlhdr = nlmsg_data(nlh);
625 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
626 info.attrs = attrbuf;
627 genl_info_net_set(&info, net);
628 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
629
630 if (family->pre_doit) {
631 err = family->pre_doit(ops, skb, &info);
632 if (err)
633 goto out;
634 }
635
636 err = ops->doit(skb, &info);
637
638 if (family->post_doit)
639 family->post_doit(ops, skb, &info);
640
641 out:
642 if (family->parallel_ops)
643 kfree(attrbuf);
644
645 return err;
646 }
647
648 static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
649 {
650 struct genl_family *family;
651 int err;
652
653 family = genl_family_find_byid(nlh->nlmsg_type);
654 if (family == NULL)
655 return -ENOENT;
656
657 if (!family->parallel_ops)
658 genl_lock();
659
660 err = genl_family_rcv_msg(family, skb, nlh);
661
662 if (!family->parallel_ops)
663 genl_unlock();
664
665 return err;
666 }
667
668 static void genl_rcv(struct sk_buff *skb)
669 {
670 down_read(&cb_lock);
671 netlink_rcv_skb(skb, &genl_rcv_msg);
672 up_read(&cb_lock);
673 }
674
675 /**************************************************************************
676 * Controller
677 **************************************************************************/
678
679 static struct genl_family genl_ctrl = {
680 .id = GENL_ID_CTRL,
681 .name = "nlctrl",
682 .version = 0x2,
683 .maxattr = CTRL_ATTR_MAX,
684 .netnsok = true,
685 };
686
687 static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq,
688 u32 flags, struct sk_buff *skb, u8 cmd)
689 {
690 void *hdr;
691
692 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
693 if (hdr == NULL)
694 return -1;
695
696 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
697 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
698 nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
699 nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
700 nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
701 goto nla_put_failure;
702
703 if (family->n_ops) {
704 struct nlattr *nla_ops;
705 int i;
706
707 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
708 if (nla_ops == NULL)
709 goto nla_put_failure;
710
711 for (i = 0; i < family->n_ops; i++) {
712 struct nlattr *nest;
713 const struct genl_ops *ops = &family->ops[i];
714 u32 op_flags = ops->flags;
715
716 if (ops->dumpit)
717 op_flags |= GENL_CMD_CAP_DUMP;
718 if (ops->doit)
719 op_flags |= GENL_CMD_CAP_DO;
720 if (ops->policy)
721 op_flags |= GENL_CMD_CAP_HASPOL;
722
723 nest = nla_nest_start(skb, i + 1);
724 if (nest == NULL)
725 goto nla_put_failure;
726
727 if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
728 nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
729 goto nla_put_failure;
730
731 nla_nest_end(skb, nest);
732 }
733
734 nla_nest_end(skb, nla_ops);
735 }
736
737 if (family->n_mcgrps) {
738 struct nlattr *nla_grps;
739 int i;
740
741 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
742 if (nla_grps == NULL)
743 goto nla_put_failure;
744
745 for (i = 0; i < family->n_mcgrps; i++) {
746 struct nlattr *nest;
747 const struct genl_multicast_group *grp;
748
749 grp = &family->mcgrps[i];
750
751 nest = nla_nest_start(skb, i + 1);
752 if (nest == NULL)
753 goto nla_put_failure;
754
755 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
756 family->mcgrp_offset + i) ||
757 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
758 grp->name))
759 goto nla_put_failure;
760
761 nla_nest_end(skb, nest);
762 }
763 nla_nest_end(skb, nla_grps);
764 }
765
766 genlmsg_end(skb, hdr);
767 return 0;
768
769 nla_put_failure:
770 genlmsg_cancel(skb, hdr);
771 return -EMSGSIZE;
772 }
773
774 static int ctrl_fill_mcgrp_info(struct genl_family *family,
775 const struct genl_multicast_group *grp,
776 int grp_id, u32 portid, u32 seq, u32 flags,
777 struct sk_buff *skb, u8 cmd)
778 {
779 void *hdr;
780 struct nlattr *nla_grps;
781 struct nlattr *nest;
782
783 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
784 if (hdr == NULL)
785 return -1;
786
787 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
788 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
789 goto nla_put_failure;
790
791 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
792 if (nla_grps == NULL)
793 goto nla_put_failure;
794
795 nest = nla_nest_start(skb, 1);
796 if (nest == NULL)
797 goto nla_put_failure;
798
799 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
800 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
801 grp->name))
802 goto nla_put_failure;
803
804 nla_nest_end(skb, nest);
805 nla_nest_end(skb, nla_grps);
806
807 genlmsg_end(skb, hdr);
808 return 0;
809
810 nla_put_failure:
811 genlmsg_cancel(skb, hdr);
812 return -EMSGSIZE;
813 }
814
815 static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
816 {
817
818 int i, n = 0;
819 struct genl_family *rt;
820 struct net *net = sock_net(skb->sk);
821 int chains_to_skip = cb->args[0];
822 int fams_to_skip = cb->args[1];
823
824 for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
825 n = 0;
826 list_for_each_entry(rt, genl_family_chain(i), family_list) {
827 if (!rt->netnsok && !net_eq(net, &init_net))
828 continue;
829 if (++n < fams_to_skip)
830 continue;
831 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
832 cb->nlh->nlmsg_seq, NLM_F_MULTI,
833 skb, CTRL_CMD_NEWFAMILY) < 0)
834 goto errout;
835 }
836
837 fams_to_skip = 0;
838 }
839
840 errout:
841 cb->args[0] = i;
842 cb->args[1] = n;
843
844 return skb->len;
845 }
846
847 static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
848 u32 portid, int seq, u8 cmd)
849 {
850 struct sk_buff *skb;
851 int err;
852
853 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
854 if (skb == NULL)
855 return ERR_PTR(-ENOBUFS);
856
857 err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
858 if (err < 0) {
859 nlmsg_free(skb);
860 return ERR_PTR(err);
861 }
862
863 return skb;
864 }
865
866 static struct sk_buff *
867 ctrl_build_mcgrp_msg(struct genl_family *family,
868 const struct genl_multicast_group *grp,
869 int grp_id, u32 portid, int seq, u8 cmd)
870 {
871 struct sk_buff *skb;
872 int err;
873
874 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
875 if (skb == NULL)
876 return ERR_PTR(-ENOBUFS);
877
878 err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
879 seq, 0, skb, cmd);
880 if (err < 0) {
881 nlmsg_free(skb);
882 return ERR_PTR(err);
883 }
884
885 return skb;
886 }
887
888 static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
889 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
890 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
891 .len = GENL_NAMSIZ - 1 },
892 };
893
894 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
895 {
896 struct sk_buff *msg;
897 struct genl_family *res = NULL;
898 int err = -EINVAL;
899
900 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
901 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
902 res = genl_family_find_byid(id);
903 err = -ENOENT;
904 }
905
906 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
907 char *name;
908
909 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
910 res = genl_family_find_byname(name);
911 #ifdef CONFIG_MODULES
912 if (res == NULL) {
913 genl_unlock();
914 up_read(&cb_lock);
915 request_module("net-pf-%d-proto-%d-family-%s",
916 PF_NETLINK, NETLINK_GENERIC, name);
917 down_read(&cb_lock);
918 genl_lock();
919 res = genl_family_find_byname(name);
920 }
921 #endif
922 err = -ENOENT;
923 }
924
925 if (res == NULL)
926 return err;
927
928 if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
929 /* family doesn't exist here */
930 return -ENOENT;
931 }
932
933 msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
934 CTRL_CMD_NEWFAMILY);
935 if (IS_ERR(msg))
936 return PTR_ERR(msg);
937
938 return genlmsg_reply(msg, info);
939 }
940
941 static int genl_ctrl_event(int event, struct genl_family *family,
942 const struct genl_multicast_group *grp,
943 int grp_id)
944 {
945 struct sk_buff *msg;
946
947 /* genl is still initialising */
948 if (!init_net.genl_sock)
949 return 0;
950
951 switch (event) {
952 case CTRL_CMD_NEWFAMILY:
953 case CTRL_CMD_DELFAMILY:
954 WARN_ON(grp);
955 msg = ctrl_build_family_msg(family, 0, 0, event);
956 break;
957 case CTRL_CMD_NEWMCAST_GRP:
958 case CTRL_CMD_DELMCAST_GRP:
959 BUG_ON(!grp);
960 msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
961 break;
962 default:
963 return -EINVAL;
964 }
965
966 if (IS_ERR(msg))
967 return PTR_ERR(msg);
968
969 if (!family->netnsok) {
970 genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
971 0, GFP_KERNEL);
972 } else {
973 rcu_read_lock();
974 genlmsg_multicast_allns(&genl_ctrl, msg, 0,
975 0, GFP_ATOMIC);
976 rcu_read_unlock();
977 }
978
979 return 0;
980 }
981
982 static const struct genl_ops genl_ctrl_ops[] = {
983 {
984 .cmd = CTRL_CMD_GETFAMILY,
985 .doit = ctrl_getfamily,
986 .dumpit = ctrl_dumpfamily,
987 .policy = ctrl_policy,
988 },
989 };
990
991 static const struct genl_multicast_group genl_ctrl_groups[] = {
992 { .name = "notify", },
993 };
994
995 static int genl_bind(struct net *net, int group)
996 {
997 int i, err = -ENOENT;
998
999 down_read(&cb_lock);
1000 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
1001 struct genl_family *f;
1002
1003 list_for_each_entry(f, genl_family_chain(i), family_list) {
1004 if (group >= f->mcgrp_offset &&
1005 group < f->mcgrp_offset + f->n_mcgrps) {
1006 int fam_grp = group - f->mcgrp_offset;
1007
1008 if (!f->netnsok && net != &init_net)
1009 err = -ENOENT;
1010 else if (f->mcast_bind)
1011 err = f->mcast_bind(net, fam_grp);
1012 else
1013 err = 0;
1014 break;
1015 }
1016 }
1017 }
1018 up_read(&cb_lock);
1019
1020 return err;
1021 }
1022
1023 static void genl_unbind(struct net *net, int group)
1024 {
1025 int i;
1026
1027 down_read(&cb_lock);
1028 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
1029 struct genl_family *f;
1030
1031 list_for_each_entry(f, genl_family_chain(i), family_list) {
1032 if (group >= f->mcgrp_offset &&
1033 group < f->mcgrp_offset + f->n_mcgrps) {
1034 int fam_grp = group - f->mcgrp_offset;
1035
1036 if (f->mcast_unbind)
1037 f->mcast_unbind(net, fam_grp);
1038 break;
1039 }
1040 }
1041 }
1042 up_read(&cb_lock);
1043 }
1044
1045 static int __net_init genl_pernet_init(struct net *net)
1046 {
1047 struct netlink_kernel_cfg cfg = {
1048 .input = genl_rcv,
1049 .flags = NL_CFG_F_NONROOT_RECV,
1050 .bind = genl_bind,
1051 .unbind = genl_unbind,
1052 };
1053
1054 /* we'll bump the group number right afterwards */
1055 net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
1056
1057 if (!net->genl_sock && net_eq(net, &init_net))
1058 panic("GENL: Cannot initialize generic netlink\n");
1059
1060 if (!net->genl_sock)
1061 return -ENOMEM;
1062
1063 return 0;
1064 }
1065
1066 static void __net_exit genl_pernet_exit(struct net *net)
1067 {
1068 netlink_kernel_release(net->genl_sock);
1069 net->genl_sock = NULL;
1070 }
1071
1072 static struct pernet_operations genl_pernet_ops = {
1073 .init = genl_pernet_init,
1074 .exit = genl_pernet_exit,
1075 };
1076
1077 static int __init genl_init(void)
1078 {
1079 int i, err;
1080
1081 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
1082 INIT_LIST_HEAD(&family_ht[i]);
1083
1084 err = genl_register_family_with_ops_groups(&genl_ctrl, genl_ctrl_ops,
1085 genl_ctrl_groups);
1086 if (err < 0)
1087 goto problem;
1088
1089 err = register_pernet_subsys(&genl_pernet_ops);
1090 if (err)
1091 goto problem;
1092
1093 return 0;
1094
1095 problem:
1096 panic("GENL: Cannot register controller: %d\n", err);
1097 }
1098
1099 subsys_initcall(genl_init);
1100
1101 static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
1102 gfp_t flags)
1103 {
1104 struct sk_buff *tmp;
1105 struct net *net, *prev = NULL;
1106 int err;
1107
1108 for_each_net_rcu(net) {
1109 if (prev) {
1110 tmp = skb_clone(skb, flags);
1111 if (!tmp) {
1112 err = -ENOMEM;
1113 goto error;
1114 }
1115 err = nlmsg_multicast(prev->genl_sock, tmp,
1116 portid, group, flags);
1117 if (err)
1118 goto error;
1119 }
1120
1121 prev = net;
1122 }
1123
1124 return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
1125 error:
1126 kfree_skb(skb);
1127 return err;
1128 }
1129
1130 int genlmsg_multicast_allns(struct genl_family *family, struct sk_buff *skb,
1131 u32 portid, unsigned int group, gfp_t flags)
1132 {
1133 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1134 return -EINVAL;
1135 group = family->mcgrp_offset + group;
1136 return genlmsg_mcast(skb, portid, group, flags);
1137 }
1138 EXPORT_SYMBOL(genlmsg_multicast_allns);
1139
1140 void genl_notify(struct genl_family *family, struct sk_buff *skb,
1141 struct genl_info *info, u32 group, gfp_t flags)
1142 {
1143 struct net *net = genl_info_net(info);
1144 struct sock *sk = net->genl_sock;
1145 int report = 0;
1146
1147 if (info->nlhdr)
1148 report = nlmsg_report(info->nlhdr);
1149
1150 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1151 return;
1152 group = family->mcgrp_offset + group;
1153 nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
1154 }
1155 EXPORT_SYMBOL(genl_notify);
Linux with added FPC-III support