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irqchip: Fix dependencies for archs w/o HAS_IOMEM
[linux/fpc-iii.git] / net / netlink / genetlink.c
blobbc0e504f33a68ee92897cb3c45241d4d3348deba
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 >= 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_locked;
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_locked:
421 genl_unlock_all();
422 errout:
423 return err;
424 }
425 EXPORT_SYMBOL(__genl_register_family);
426
427 /**
428 * genl_unregister_family - unregister generic netlink family
429 * @family: generic netlink family
430 *
431 * Unregisters the specified family.
432 *
433 * Returns 0 on success or a negative error code.
434 */
435 int genl_unregister_family(struct genl_family *family)
436 {
437 struct genl_family *rc;
438
439 genl_lock_all();
440
441 list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
442 if (family->id != rc->id || strcmp(rc->name, family->name))
443 continue;
444
445 genl_unregister_mc_groups(family);
446
447 list_del(&rc->family_list);
448 family->n_ops = 0;
449 up_write(&cb_lock);
450 wait_event(genl_sk_destructing_waitq,
451 atomic_read(&genl_sk_destructing_cnt) == 0);
452 genl_unlock();
453
454 kfree(family->attrbuf);
455 genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
456 return 0;
457 }
458
459 genl_unlock_all();
460
461 return -ENOENT;
462 }
463 EXPORT_SYMBOL(genl_unregister_family);
464
465 /**
466 * genlmsg_new_unicast - Allocate generic netlink message for unicast
467 * @payload: size of the message payload
468 * @info: information on destination
469 * @flags: the type of memory to allocate
470 *
471 * Allocates a new sk_buff large enough to cover the specified payload
472 * plus required Netlink headers. Will check receiving socket for
473 * memory mapped i/o capability and use it if enabled. Will fall back
474 * to non-mapped skb if message size exceeds the frame size of the ring.
475 */
476 struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
477 gfp_t flags)
478 {
479 size_t len = nlmsg_total_size(genlmsg_total_size(payload));
480
481 return netlink_alloc_skb(info->dst_sk, len, info->snd_portid, flags);
482 }
483 EXPORT_SYMBOL_GPL(genlmsg_new_unicast);
484
485 /**
486 * genlmsg_put - Add generic netlink header to netlink message
487 * @skb: socket buffer holding the message
488 * @portid: netlink portid the message is addressed to
489 * @seq: sequence number (usually the one of the sender)
490 * @family: generic netlink family
491 * @flags: netlink message flags
492 * @cmd: generic netlink command
493 *
494 * Returns pointer to user specific header
495 */
496 void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
497 struct genl_family *family, int flags, u8 cmd)
498 {
499 struct nlmsghdr *nlh;
500 struct genlmsghdr *hdr;
501
502 nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
503 family->hdrsize, flags);
504 if (nlh == NULL)
505 return NULL;
506
507 hdr = nlmsg_data(nlh);
508 hdr->cmd = cmd;
509 hdr->version = family->version;
510 hdr->reserved = 0;
511
512 return (char *) hdr + GENL_HDRLEN;
513 }
514 EXPORT_SYMBOL(genlmsg_put);
515
516 static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
517 {
518 /* our ops are always const - netlink API doesn't propagate that */
519 const struct genl_ops *ops = cb->data;
520 int rc;
521
522 genl_lock();
523 rc = ops->dumpit(skb, cb);
524 genl_unlock();
525 return rc;
526 }
527
528 static int genl_lock_done(struct netlink_callback *cb)
529 {
530 /* our ops are always const - netlink API doesn't propagate that */
531 const struct genl_ops *ops = cb->data;
532 int rc = 0;
533
534 if (ops->done) {
535 genl_lock();
536 rc = ops->done(cb);
537 genl_unlock();
538 }
539 return rc;
540 }
541
542 static int genl_family_rcv_msg(struct genl_family *family,
543 struct sk_buff *skb,
544 struct nlmsghdr *nlh)
545 {
546 const struct genl_ops *ops;
547 struct net *net = sock_net(skb->sk);
548 struct genl_info info;
549 struct genlmsghdr *hdr = nlmsg_data(nlh);
550 struct nlattr **attrbuf;
551 int hdrlen, err;
552
553 /* this family doesn't exist in this netns */
554 if (!family->netnsok && !net_eq(net, &init_net))
555 return -ENOENT;
556
557 hdrlen = GENL_HDRLEN + family->hdrsize;
558 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
559 return -EINVAL;
560
561 ops = genl_get_cmd(hdr->cmd, family);
562 if (ops == NULL)
563 return -EOPNOTSUPP;
564
565 if ((ops->flags & GENL_ADMIN_PERM) &&
566 !netlink_capable(skb, 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 .dump = genl_lock_dumpit,
581 .done = genl_lock_done,
582 };
583
584 genl_unlock();
585 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
586 genl_lock();
587
588 } else {
589 struct netlink_dump_control c = {
590 .module = family->module,
591 .dump = ops->dumpit,
592 .done = ops->done,
593 };
594
595 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
596 }
597
598 return rc;
599 }
600
601 if (ops->doit == NULL)
602 return -EOPNOTSUPP;
603
604 if (family->maxattr && family->parallel_ops) {
605 attrbuf = kmalloc((family->maxattr+1) *
606 sizeof(struct nlattr *), GFP_KERNEL);
607 if (attrbuf == NULL)
608 return -ENOMEM;
609 } else
610 attrbuf = family->attrbuf;
611
612 if (attrbuf) {
613 err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
614 ops->policy);
615 if (err < 0)
616 goto out;
617 }
618
619 info.snd_seq = nlh->nlmsg_seq;
620 info.snd_portid = NETLINK_CB(skb).portid;
621 info.nlhdr = nlh;
622 info.genlhdr = nlmsg_data(nlh);
623 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
624 info.attrs = attrbuf;
625 info.dst_sk = skb->sk;
626 genl_info_net_set(&info, net);
627 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
628
629 if (family->pre_doit) {
630 err = family->pre_doit(ops, skb, &info);
631 if (err)
632 goto out;
633 }
634
635 err = ops->doit(skb, &info);
636
637 if (family->post_doit)
638 family->post_doit(ops, skb, &info);
639
640 out:
641 if (family->parallel_ops)
642 kfree(attrbuf);
643
644 return err;
645 }
646
647 static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
648 {
649 struct genl_family *family;
650 int err;
651
652 family = genl_family_find_byid(nlh->nlmsg_type);
653 if (family == NULL)
654 return -ENOENT;
655
656 if (!family->parallel_ops)
657 genl_lock();
658
659 err = genl_family_rcv_msg(family, skb, nlh);
660
661 if (!family->parallel_ops)
662 genl_unlock();
663
664 return err;
665 }
666
667 static void genl_rcv(struct sk_buff *skb)
668 {
669 down_read(&cb_lock);
670 netlink_rcv_skb(skb, &genl_rcv_msg);
671 up_read(&cb_lock);
672 }
673
674 /**************************************************************************
675 * Controller
676 **************************************************************************/
677
678 static struct genl_family genl_ctrl = {
679 .id = GENL_ID_CTRL,
680 .name = "nlctrl",
681 .version = 0x2,
682 .maxattr = CTRL_ATTR_MAX,
683 .netnsok = true,
684 };
685
686 static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq,
687 u32 flags, struct sk_buff *skb, u8 cmd)
688 {
689 void *hdr;
690
691 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
692 if (hdr == NULL)
693 return -1;
694
695 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
696 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
697 nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
698 nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
699 nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
700 goto nla_put_failure;
701
702 if (family->n_ops) {
703 struct nlattr *nla_ops;
704 int i;
705
706 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
707 if (nla_ops == NULL)
708 goto nla_put_failure;
709
710 for (i = 0; i < family->n_ops; i++) {
711 struct nlattr *nest;
712 const struct genl_ops *ops = &family->ops[i];
713 u32 op_flags = ops->flags;
714
715 if (ops->dumpit)
716 op_flags |= GENL_CMD_CAP_DUMP;
717 if (ops->doit)
718 op_flags |= GENL_CMD_CAP_DO;
719 if (ops->policy)
720 op_flags |= GENL_CMD_CAP_HASPOL;
721
722 nest = nla_nest_start(skb, i + 1);
723 if (nest == NULL)
724 goto nla_put_failure;
725
726 if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
727 nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
728 goto nla_put_failure;
729
730 nla_nest_end(skb, nest);
731 }
732
733 nla_nest_end(skb, nla_ops);
734 }
735
736 if (family->n_mcgrps) {
737 struct nlattr *nla_grps;
738 int i;
739
740 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
741 if (nla_grps == NULL)
742 goto nla_put_failure;
743
744 for (i = 0; i < family->n_mcgrps; i++) {
745 struct nlattr *nest;
746 const struct genl_multicast_group *grp;
747
748 grp = &family->mcgrps[i];
749
750 nest = nla_nest_start(skb, i + 1);
751 if (nest == NULL)
752 goto nla_put_failure;
753
754 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
755 family->mcgrp_offset + i) ||
756 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
757 grp->name))
758 goto nla_put_failure;
759
760 nla_nest_end(skb, nest);
761 }
762 nla_nest_end(skb, nla_grps);
763 }
764
765 genlmsg_end(skb, hdr);
766 return 0;
767
768 nla_put_failure:
769 genlmsg_cancel(skb, hdr);
770 return -EMSGSIZE;
771 }
772
773 static int ctrl_fill_mcgrp_info(struct genl_family *family,
774 const struct genl_multicast_group *grp,
775 int grp_id, u32 portid, u32 seq, u32 flags,
776 struct sk_buff *skb, u8 cmd)
777 {
778 void *hdr;
779 struct nlattr *nla_grps;
780 struct nlattr *nest;
781
782 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
783 if (hdr == NULL)
784 return -1;
785
786 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
787 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
788 goto nla_put_failure;
789
790 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
791 if (nla_grps == NULL)
792 goto nla_put_failure;
793
794 nest = nla_nest_start(skb, 1);
795 if (nest == NULL)
796 goto nla_put_failure;
797
798 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
799 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
800 grp->name))
801 goto nla_put_failure;
802
803 nla_nest_end(skb, nest);
804 nla_nest_end(skb, nla_grps);
805
806 genlmsg_end(skb, hdr);
807 return 0;
808
809 nla_put_failure:
810 genlmsg_cancel(skb, hdr);
811 return -EMSGSIZE;
812 }
813
814 static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
815 {
816
817 int i, n = 0;
818 struct genl_family *rt;
819 struct net *net = sock_net(skb->sk);
820 int chains_to_skip = cb->args[0];
821 int fams_to_skip = cb->args[1];
822
823 for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
824 n = 0;
825 list_for_each_entry(rt, genl_family_chain(i), family_list) {
826 if (!rt->netnsok && !net_eq(net, &init_net))
827 continue;
828 if (++n < fams_to_skip)
829 continue;
830 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
831 cb->nlh->nlmsg_seq, NLM_F_MULTI,
832 skb, CTRL_CMD_NEWFAMILY) < 0)
833 goto errout;
834 }
835
836 fams_to_skip = 0;
837 }
838
839 errout:
840 cb->args[0] = i;
841 cb->args[1] = n;
842
843 return skb->len;
844 }
845
846 static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
847 u32 portid, int seq, u8 cmd)
848 {
849 struct sk_buff *skb;
850 int err;
851
852 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
853 if (skb == NULL)
854 return ERR_PTR(-ENOBUFS);
855
856 err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
857 if (err < 0) {
858 nlmsg_free(skb);
859 return ERR_PTR(err);
860 }
861
862 return skb;
863 }
864
865 static struct sk_buff *
866 ctrl_build_mcgrp_msg(struct genl_family *family,
867 const struct genl_multicast_group *grp,
868 int grp_id, u32 portid, int seq, u8 cmd)
869 {
870 struct sk_buff *skb;
871 int err;
872
873 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
874 if (skb == NULL)
875 return ERR_PTR(-ENOBUFS);
876
877 err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
878 seq, 0, skb, cmd);
879 if (err < 0) {
880 nlmsg_free(skb);
881 return ERR_PTR(err);
882 }
883
884 return skb;
885 }
886
887 static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
888 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
889 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
890 .len = GENL_NAMSIZ - 1 },
891 };
892
893 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
894 {
895 struct sk_buff *msg;
896 struct genl_family *res = NULL;
897 int err = -EINVAL;
898
899 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
900 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
901 res = genl_family_find_byid(id);
902 err = -ENOENT;
903 }
904
905 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
906 char *name;
907
908 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
909 res = genl_family_find_byname(name);
910 #ifdef CONFIG_MODULES
911 if (res == NULL) {
912 genl_unlock();
913 up_read(&cb_lock);
914 request_module("net-pf-%d-proto-%d-family-%s",
915 PF_NETLINK, NETLINK_GENERIC, name);
916 down_read(&cb_lock);
917 genl_lock();
918 res = genl_family_find_byname(name);
919 }
920 #endif
921 err = -ENOENT;
922 }
923
924 if (res == NULL)
925 return err;
926
927 if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
928 /* family doesn't exist here */
929 return -ENOENT;
930 }
931
932 msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
933 CTRL_CMD_NEWFAMILY);
934 if (IS_ERR(msg))
935 return PTR_ERR(msg);
936
937 return genlmsg_reply(msg, info);
938 }
939
940 static int genl_ctrl_event(int event, struct genl_family *family,
941 const struct genl_multicast_group *grp,
942 int grp_id)
943 {
944 struct sk_buff *msg;
945
946 /* genl is still initialising */
947 if (!init_net.genl_sock)
948 return 0;
949
950 switch (event) {
951 case CTRL_CMD_NEWFAMILY:
952 case CTRL_CMD_DELFAMILY:
953 WARN_ON(grp);
954 msg = ctrl_build_family_msg(family, 0, 0, event);
955 break;
956 case CTRL_CMD_NEWMCAST_GRP:
957 case CTRL_CMD_DELMCAST_GRP:
958 BUG_ON(!grp);
959 msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
960 break;
961 default:
962 return -EINVAL;
963 }
964
965 if (IS_ERR(msg))
966 return PTR_ERR(msg);
967
968 if (!family->netnsok) {
969 genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
970 0, GFP_KERNEL);
971 } else {
972 rcu_read_lock();
973 genlmsg_multicast_allns(&genl_ctrl, msg, 0,
974 0, GFP_ATOMIC);
975 rcu_read_unlock();
976 }
977
978 return 0;
979 }
980
981 static struct genl_ops genl_ctrl_ops[] = {
982 {
983 .cmd = CTRL_CMD_GETFAMILY,
984 .doit = ctrl_getfamily,
985 .dumpit = ctrl_dumpfamily,
986 .policy = ctrl_policy,
987 },
988 };
989
990 static struct genl_multicast_group genl_ctrl_groups[] = {
991 { .name = "notify", },
992 };
993
994 static int genl_bind(struct net *net, int group)
995 {
996 int i, err = -ENOENT;
997
998 down_read(&cb_lock);
999 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
1000 struct genl_family *f;
1001
1002 list_for_each_entry(f, genl_family_chain(i), family_list) {
1003 if (group >= f->mcgrp_offset &&
1004 group < f->mcgrp_offset + f->n_mcgrps) {
1005 int fam_grp = group - f->mcgrp_offset;
1006
1007 if (!f->netnsok && net != &init_net)
1008 err = -ENOENT;
1009 else if (f->mcast_bind)
1010 err = f->mcast_bind(net, fam_grp);
1011 else
1012 err = 0;
1013 break;
1014 }
1015 }
1016 }
1017 up_read(&cb_lock);
1018
1019 return err;
1020 }
1021
1022 static void genl_unbind(struct net *net, int group)
1023 {
1024 int i;
1025
1026 down_read(&cb_lock);
1027 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
1028 struct genl_family *f;
1029
1030 list_for_each_entry(f, genl_family_chain(i), family_list) {
1031 if (group >= f->mcgrp_offset &&
1032 group < f->mcgrp_offset + f->n_mcgrps) {
1033 int fam_grp = group - f->mcgrp_offset;
1034
1035 if (f->mcast_unbind)
1036 f->mcast_unbind(net, fam_grp);
1037 break;
1038 }
1039 }
1040 }
1041 up_read(&cb_lock);
1042 }
1043
1044 static int __net_init genl_pernet_init(struct net *net)
1045 {
1046 struct netlink_kernel_cfg cfg = {
1047 .input = genl_rcv,
1048 .flags = NL_CFG_F_NONROOT_RECV,
1049 .bind = genl_bind,
1050 .unbind = genl_unbind,
1051 };
1052
1053 /* we'll bump the group number right afterwards */
1054 net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
1055
1056 if (!net->genl_sock && net_eq(net, &init_net))
1057 panic("GENL: Cannot initialize generic netlink\n");
1058
1059 if (!net->genl_sock)
1060 return -ENOMEM;
1061
1062 return 0;
1063 }
1064
1065 static void __net_exit genl_pernet_exit(struct net *net)
1066 {
1067 netlink_kernel_release(net->genl_sock);
1068 net->genl_sock = NULL;
1069 }
1070
1071 static struct pernet_operations genl_pernet_ops = {
1072 .init = genl_pernet_init,
1073 .exit = genl_pernet_exit,
1074 };
1075
1076 static int __init genl_init(void)
1077 {
1078 int i, err;
1079
1080 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
1081 INIT_LIST_HEAD(&family_ht[i]);
1082
1083 err = genl_register_family_with_ops_groups(&genl_ctrl, genl_ctrl_ops,
1084 genl_ctrl_groups);
1085 if (err < 0)
1086 goto problem;
1087
1088 err = register_pernet_subsys(&genl_pernet_ops);
1089 if (err)
1090 goto problem;
1091
1092 return 0;
1093
1094 problem:
1095 panic("GENL: Cannot register controller: %d\n", err);
1096 }
1097
1098 subsys_initcall(genl_init);
1099
1100 static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
1101 gfp_t flags)
1102 {
1103 struct sk_buff *tmp;
1104 struct net *net, *prev = NULL;
1105 int err;
1106
1107 for_each_net_rcu(net) {
1108 if (prev) {
1109 tmp = skb_clone(skb, flags);
1110 if (!tmp) {
1111 err = -ENOMEM;
1112 goto error;
1113 }
1114 err = nlmsg_multicast(prev->genl_sock, tmp,
1115 portid, group, flags);
1116 if (err)
1117 goto error;
1118 }
1119
1120 prev = net;
1121 }
1122
1123 return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
1124 error:
1125 kfree_skb(skb);
1126 return err;
1127 }
1128
1129 int genlmsg_multicast_allns(struct genl_family *family, struct sk_buff *skb,
1130 u32 portid, unsigned int group, gfp_t flags)
1131 {
1132 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1133 return -EINVAL;
1134 group = family->mcgrp_offset + group;
1135 return genlmsg_mcast(skb, portid, group, flags);
1136 }
1137 EXPORT_SYMBOL(genlmsg_multicast_allns);
1138
1139 void genl_notify(struct genl_family *family, struct sk_buff *skb,
1140 struct genl_info *info, u32 group, gfp_t flags)
1141 {
1142 struct net *net = genl_info_net(info);
1143 struct sock *sk = net->genl_sock;
1144 int report = 0;
1145
1146 if (info->nlhdr)
1147 report = nlmsg_report(info->nlhdr);
1148
1149 if (WARN_ON_ONCE(group >= family->n_mcgrps))
1150 return;
1151 group = family->mcgrp_offset + group;
1152 nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
1153 }
1154 EXPORT_SYMBOL(genl_notify);
Linux with added FPC-III support