44ff3f3810faa6c94e15c9b5f6b40312cf1c1182
[linux-2.6.git] / net / netlink / genetlink.c
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/errno.h>
12 #include <linux/types.h>
13 #include <linux/socket.h>
14 #include <linux/string.h>
15 #include <linux/skbuff.h>
16 #include <linux/mutex.h>
17 #include <linux/bitmap.h>
18 #include <net/sock.h>
19 #include <net/genetlink.h>
20
21 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
22
23 static inline void genl_lock(void)
24 {
25         mutex_lock(&genl_mutex);
26 }
27
28 static inline void genl_unlock(void)
29 {
30         mutex_unlock(&genl_mutex);
31 }
32
33 #define GENL_FAM_TAB_SIZE       16
34 #define GENL_FAM_TAB_MASK       (GENL_FAM_TAB_SIZE - 1)
35
36 static struct list_head family_ht[GENL_FAM_TAB_SIZE];
37 /*
38  * Bitmap of multicast groups that are currently in use.
39  *
40  * To avoid an allocation at boot of just one unsigned long,
41  * declare it global instead.
42  * Bit 0 is marked as already used since group 0 is invalid.
43  */
44 static unsigned long mc_group_start = 0x1;
45 static unsigned long *mc_groups = &mc_group_start;
46 static unsigned long mc_groups_longs = 1;
47
48 static int genl_ctrl_event(int event, void *data);
49
50 static inline unsigned int genl_family_hash(unsigned int id)
51 {
52         return id & GENL_FAM_TAB_MASK;
53 }
54
55 static inline struct list_head *genl_family_chain(unsigned int id)
56 {
57         return &family_ht[genl_family_hash(id)];
58 }
59
60 static struct genl_family *genl_family_find_byid(unsigned int id)
61 {
62         struct genl_family *f;
63
64         list_for_each_entry(f, genl_family_chain(id), family_list)
65                 if (f->id == id)
66                         return f;
67
68         return NULL;
69 }
70
71 static struct genl_family *genl_family_find_byname(char *name)
72 {
73         struct genl_family *f;
74         int i;
75
76         for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
77                 list_for_each_entry(f, genl_family_chain(i), family_list)
78                         if (strcmp(f->name, name) == 0)
79                                 return f;
80
81         return NULL;
82 }
83
84 static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
85 {
86         struct genl_ops *ops;
87
88         list_for_each_entry(ops, &family->ops_list, ops_list)
89                 if (ops->cmd == cmd)
90                         return ops;
91
92         return NULL;
93 }
94
95 /* Of course we are going to have problems once we hit
96  * 2^16 alive types, but that can only happen by year 2K
97 */
98 static inline u16 genl_generate_id(void)
99 {
100         static u16 id_gen_idx;
101         int overflowed = 0;
102
103         do {
104                 if (id_gen_idx == 0)
105                         id_gen_idx = GENL_MIN_ID;
106
107                 if (++id_gen_idx > GENL_MAX_ID) {
108                         if (!overflowed) {
109                                 overflowed = 1;
110                                 id_gen_idx = 0;
111                                 continue;
112                         } else
113                                 return 0;
114                 }
115
116         } while (genl_family_find_byid(id_gen_idx));
117
118         return id_gen_idx;
119 }
120
121 static struct genl_multicast_group notify_grp;
122
123 /**
124  * genl_register_mc_group - register a multicast group
125  *
126  * Registers the specified multicast group and notifies userspace
127  * about the new group.
128  *
129  * Returns 0 on success or a negative error code.
130  *
131  * @family: The generic netlink family the group shall be registered for.
132  * @grp: The group to register, must have a name.
133  */
134 int genl_register_mc_group(struct genl_family *family,
135                            struct genl_multicast_group *grp)
136 {
137         int id;
138         unsigned long *new_groups;
139         int err = 0;
140
141         BUG_ON(grp->name[0] == '\0');
142
143         genl_lock();
144
145         /* special-case our own group */
146         if (grp == &notify_grp)
147                 id = GENL_ID_CTRL;
148         else
149                 id = find_first_zero_bit(mc_groups,
150                                          mc_groups_longs * BITS_PER_LONG);
151
152
153         if (id >= mc_groups_longs * BITS_PER_LONG) {
154                 size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long);
155
156                 if (mc_groups == &mc_group_start) {
157                         new_groups = kzalloc(nlen, GFP_KERNEL);
158                         if (!new_groups) {
159                                 err = -ENOMEM;
160                                 goto out;
161                         }
162                         mc_groups = new_groups;
163                         *mc_groups = mc_group_start;
164                 } else {
165                         new_groups = krealloc(mc_groups, nlen, GFP_KERNEL);
166                         if (!new_groups) {
167                                 err = -ENOMEM;
168                                 goto out;
169                         }
170                         mc_groups = new_groups;
171                         mc_groups[mc_groups_longs] = 0;
172                 }
173                 mc_groups_longs++;
174         }
175
176         if (family->netnsok) {
177                 struct net *net;
178
179                 netlink_table_grab();
180                 rcu_read_lock();
181                 for_each_net_rcu(net) {
182                         err = __netlink_change_ngroups(net->genl_sock,
183                                         mc_groups_longs * BITS_PER_LONG);
184                         if (err) {
185                                 /*
186                                  * No need to roll back, can only fail if
187                                  * memory allocation fails and then the
188                                  * number of _possible_ groups has been
189                                  * increased on some sockets which is ok.
190                                  */
191                                 rcu_read_unlock();
192                                 netlink_table_ungrab();
193                                 goto out;
194                         }
195                 }
196                 rcu_read_unlock();
197                 netlink_table_ungrab();
198         } else {
199                 err = netlink_change_ngroups(init_net.genl_sock,
200                                              mc_groups_longs * BITS_PER_LONG);
201                 if (err)
202                         goto out;
203         }
204
205         grp->id = id;
206         set_bit(id, mc_groups);
207         list_add_tail(&grp->list, &family->mcast_groups);
208         grp->family = family;
209
210         genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
211  out:
212         genl_unlock();
213         return err;
214 }
215 EXPORT_SYMBOL(genl_register_mc_group);
216
217 static void __genl_unregister_mc_group(struct genl_family *family,
218                                        struct genl_multicast_group *grp)
219 {
220         struct net *net;
221         BUG_ON(grp->family != family);
222
223         netlink_table_grab();
224         rcu_read_lock();
225         for_each_net_rcu(net)
226                 __netlink_clear_multicast_users(net->genl_sock, grp->id);
227         rcu_read_unlock();
228         netlink_table_ungrab();
229
230         clear_bit(grp->id, mc_groups);
231         list_del(&grp->list);
232         genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
233         grp->id = 0;
234         grp->family = NULL;
235 }
236
237 /**
238  * genl_unregister_mc_group - unregister a multicast group
239  *
240  * Unregisters the specified multicast group and notifies userspace
241  * about it. All current listeners on the group are removed.
242  *
243  * Note: It is not necessary to unregister all multicast groups before
244  *       unregistering the family, unregistering the family will cause
245  *       all assigned multicast groups to be unregistered automatically.
246  *
247  * @family: Generic netlink family the group belongs to.
248  * @grp: The group to unregister, must have been registered successfully
249  *       previously.
250  */
251 void genl_unregister_mc_group(struct genl_family *family,
252                               struct genl_multicast_group *grp)
253 {
254         genl_lock();
255         __genl_unregister_mc_group(family, grp);
256         genl_unlock();
257 }
258 EXPORT_SYMBOL(genl_unregister_mc_group);
259
260 static void genl_unregister_mc_groups(struct genl_family *family)
261 {
262         struct genl_multicast_group *grp, *tmp;
263
264         list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
265                 __genl_unregister_mc_group(family, grp);
266 }
267
268 /**
269  * genl_register_ops - register generic netlink operations
270  * @family: generic netlink family
271  * @ops: operations to be registered
272  *
273  * Registers the specified operations and assigns them to the specified
274  * family. Either a doit or dumpit callback must be specified or the
275  * operation will fail. Only one operation structure per command
276  * identifier may be registered.
277  *
278  * See include/net/genetlink.h for more documenation on the operations
279  * structure.
280  *
281  * Returns 0 on success or a negative error code.
282  */
283 int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
284 {
285         int err = -EINVAL;
286
287         if (ops->dumpit == NULL && ops->doit == NULL)
288                 goto errout;
289
290         if (genl_get_cmd(ops->cmd, family)) {
291                 err = -EEXIST;
292                 goto errout;
293         }
294
295         if (ops->dumpit)
296                 ops->flags |= GENL_CMD_CAP_DUMP;
297         if (ops->doit)
298                 ops->flags |= GENL_CMD_CAP_DO;
299         if (ops->policy)
300                 ops->flags |= GENL_CMD_CAP_HASPOL;
301
302         genl_lock();
303         list_add_tail(&ops->ops_list, &family->ops_list);
304         genl_unlock();
305
306         genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
307         err = 0;
308 errout:
309         return err;
310 }
311
312 /**
313  * genl_unregister_ops - unregister generic netlink operations
314  * @family: generic netlink family
315  * @ops: operations to be unregistered
316  *
317  * Unregisters the specified operations and unassigns them from the
318  * specified family. The operation blocks until the current message
319  * processing has finished and doesn't start again until the
320  * unregister process has finished.
321  *
322  * Note: It is not necessary to unregister all operations before
323  *       unregistering the family, unregistering the family will cause
324  *       all assigned operations to be unregistered automatically.
325  *
326  * Returns 0 on success or a negative error code.
327  */
328 int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
329 {
330         struct genl_ops *rc;
331
332         genl_lock();
333         list_for_each_entry(rc, &family->ops_list, ops_list) {
334                 if (rc == ops) {
335                         list_del(&ops->ops_list);
336                         genl_unlock();
337                         genl_ctrl_event(CTRL_CMD_DELOPS, ops);
338                         return 0;
339                 }
340         }
341         genl_unlock();
342
343         return -ENOENT;
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  * Return 0 on success or a negative error code.
356  */
357 int genl_register_family(struct genl_family *family)
358 {
359         int err = -EINVAL;
360
361         if (family->id && family->id < GENL_MIN_ID)
362                 goto errout;
363
364         if (family->id > GENL_MAX_ID)
365                 goto errout;
366
367         INIT_LIST_HEAD(&family->ops_list);
368         INIT_LIST_HEAD(&family->mcast_groups);
369
370         genl_lock();
371
372         if (genl_family_find_byname(family->name)) {
373                 err = -EEXIST;
374                 goto errout_locked;
375         }
376
377         if (genl_family_find_byid(family->id)) {
378                 err = -EEXIST;
379                 goto errout_locked;
380         }
381
382         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;
391         }
392
393         if (family->maxattr) {
394                 family->attrbuf = kmalloc((family->maxattr+1) *
395                                         sizeof(struct nlattr *), GFP_KERNEL);
396                 if (family->attrbuf == NULL) {
397                         err = -ENOMEM;
398                         goto errout_locked;
399                 }
400         } else
401                 family->attrbuf = NULL;
402
403         list_add_tail(&family->family_list, genl_family_chain(family->id));
404         genl_unlock();
405
406         genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
407
408         return 0;
409
410 errout_locked:
411         genl_unlock();
412 errout:
413         return err;
414 }
415
416 /**
417  * genl_register_family_with_ops - register a generic netlink family
418  * @family: generic netlink family
419  * @ops: operations to be registered
420  * @n_ops: number of elements to register
421  *
422  * Registers the specified family and operations from the specified table.
423  * Only one family may be registered with the same family name or identifier.
424  *
425  * The family id may equal GENL_ID_GENERATE causing an unique id to
426  * be automatically generated and assigned.
427  *
428  * Either a doit or dumpit callback must be specified for every registered
429  * operation or the function will fail. Only one operation structure per
430  * command identifier may be registered.
431  *
432  * See include/net/genetlink.h for more documenation on the operations
433  * structure.
434  *
435  * This is equivalent to calling genl_register_family() followed by
436  * genl_register_ops() for every operation entry in the table taking
437  * care to unregister the family on error path.
438  *
439  * Return 0 on success or a negative error code.
440  */
441 int genl_register_family_with_ops(struct genl_family *family,
442         struct genl_ops *ops, size_t n_ops)
443 {
444         int err, i;
445
446         err = genl_register_family(family);
447         if (err)
448                 return err;
449
450         for (i = 0; i < n_ops; ++i, ++ops) {
451                 err = genl_register_ops(family, ops);
452                 if (err)
453                         goto err_out;
454         }
455         return 0;
456 err_out:
457         genl_unregister_family(family);
458         return err;
459 }
460 EXPORT_SYMBOL(genl_register_family_with_ops);
461
462 /**
463  * genl_unregister_family - unregister generic netlink family
464  * @family: generic netlink family
465  *
466  * Unregisters the specified family.
467  *
468  * Returns 0 on success or a negative error code.
469  */
470 int genl_unregister_family(struct genl_family *family)
471 {
472         struct genl_family *rc;
473
474         genl_lock();
475
476         genl_unregister_mc_groups(family);
477
478         list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
479                 if (family->id != rc->id || strcmp(rc->name, family->name))
480                         continue;
481
482                 list_del(&rc->family_list);
483                 INIT_LIST_HEAD(&family->ops_list);
484                 genl_unlock();
485
486                 kfree(family->attrbuf);
487                 genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
488                 return 0;
489         }
490
491         genl_unlock();
492
493         return -ENOENT;
494 }
495
496 static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
497 {
498         struct genl_ops *ops;
499         struct genl_family *family;
500         struct net *net = sock_net(skb->sk);
501         struct genl_info info;
502         struct genlmsghdr *hdr = nlmsg_data(nlh);
503         int hdrlen, err;
504
505         family = genl_family_find_byid(nlh->nlmsg_type);
506         if (family == NULL)
507                 return -ENOENT;
508
509         /* this family doesn't exist in this netns */
510         if (!family->netnsok && !net_eq(net, &init_net))
511                 return -ENOENT;
512
513         hdrlen = GENL_HDRLEN + family->hdrsize;
514         if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
515                 return -EINVAL;
516
517         ops = genl_get_cmd(hdr->cmd, family);
518         if (ops == NULL)
519                 return -EOPNOTSUPP;
520
521         if ((ops->flags & GENL_ADMIN_PERM) &&
522             security_netlink_recv(skb, CAP_NET_ADMIN))
523                 return -EPERM;
524
525         if (nlh->nlmsg_flags & NLM_F_DUMP) {
526                 if (ops->dumpit == NULL)
527                         return -EOPNOTSUPP;
528
529                 genl_unlock();
530                 err = netlink_dump_start(net->genl_sock, skb, nlh,
531                                          ops->dumpit, ops->done);
532                 genl_lock();
533                 return err;
534         }
535
536         if (ops->doit == NULL)
537                 return -EOPNOTSUPP;
538
539         if (family->attrbuf) {
540                 err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
541                                   ops->policy);
542                 if (err < 0)
543                         return err;
544         }
545
546         info.snd_seq = nlh->nlmsg_seq;
547         info.snd_pid = NETLINK_CB(skb).pid;
548         info.nlhdr = nlh;
549         info.genlhdr = nlmsg_data(nlh);
550         info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
551         info.attrs = family->attrbuf;
552         genl_info_net_set(&info, net);
553
554         return ops->doit(skb, &info);
555 }
556
557 static void genl_rcv(struct sk_buff *skb)
558 {
559         genl_lock();
560         netlink_rcv_skb(skb, &genl_rcv_msg);
561         genl_unlock();
562 }
563
564 /**************************************************************************
565  * Controller
566  **************************************************************************/
567
568 static struct genl_family genl_ctrl = {
569         .id = GENL_ID_CTRL,
570         .name = "nlctrl",
571         .version = 0x2,
572         .maxattr = CTRL_ATTR_MAX,
573         .netnsok = true,
574 };
575
576 static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
577                           u32 flags, struct sk_buff *skb, u8 cmd)
578 {
579         void *hdr;
580
581         hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
582         if (hdr == NULL)
583                 return -1;
584
585         NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name);
586         NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id);
587         NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version);
588         NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize);
589         NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr);
590
591         if (!list_empty(&family->ops_list)) {
592                 struct nlattr *nla_ops;
593                 struct genl_ops *ops;
594                 int idx = 1;
595
596                 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
597                 if (nla_ops == NULL)
598                         goto nla_put_failure;
599
600                 list_for_each_entry(ops, &family->ops_list, ops_list) {
601                         struct nlattr *nest;
602
603                         nest = nla_nest_start(skb, idx++);
604                         if (nest == NULL)
605                                 goto nla_put_failure;
606
607                         NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
608                         NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
609
610                         nla_nest_end(skb, nest);
611                 }
612
613                 nla_nest_end(skb, nla_ops);
614         }
615
616         if (!list_empty(&family->mcast_groups)) {
617                 struct genl_multicast_group *grp;
618                 struct nlattr *nla_grps;
619                 int idx = 1;
620
621                 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
622                 if (nla_grps == NULL)
623                         goto nla_put_failure;
624
625                 list_for_each_entry(grp, &family->mcast_groups, list) {
626                         struct nlattr *nest;
627
628                         nest = nla_nest_start(skb, idx++);
629                         if (nest == NULL)
630                                 goto nla_put_failure;
631
632                         NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
633                         NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
634                                        grp->name);
635
636                         nla_nest_end(skb, nest);
637                 }
638                 nla_nest_end(skb, nla_grps);
639         }
640
641         return genlmsg_end(skb, hdr);
642
643 nla_put_failure:
644         genlmsg_cancel(skb, hdr);
645         return -EMSGSIZE;
646 }
647
648 static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
649                                 u32 seq, u32 flags, struct sk_buff *skb,
650                                 u8 cmd)
651 {
652         void *hdr;
653         struct nlattr *nla_grps;
654         struct nlattr *nest;
655
656         hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
657         if (hdr == NULL)
658                 return -1;
659
660         NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name);
661         NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id);
662
663         nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
664         if (nla_grps == NULL)
665                 goto nla_put_failure;
666
667         nest = nla_nest_start(skb, 1);
668         if (nest == NULL)
669                 goto nla_put_failure;
670
671         NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
672         NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
673                        grp->name);
674
675         nla_nest_end(skb, nest);
676         nla_nest_end(skb, nla_grps);
677
678         return genlmsg_end(skb, hdr);
679
680 nla_put_failure:
681         genlmsg_cancel(skb, hdr);
682         return -EMSGSIZE;
683 }
684
685 static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
686 {
687
688         int i, n = 0;
689         struct genl_family *rt;
690         struct net *net = sock_net(skb->sk);
691         int chains_to_skip = cb->args[0];
692         int fams_to_skip = cb->args[1];
693
694         for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
695                 if (i < chains_to_skip)
696                         continue;
697                 n = 0;
698                 list_for_each_entry(rt, genl_family_chain(i), family_list) {
699                         if (!rt->netnsok && !net_eq(net, &init_net))
700                                 continue;
701                         if (++n < fams_to_skip)
702                                 continue;
703                         if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
704                                            cb->nlh->nlmsg_seq, NLM_F_MULTI,
705                                            skb, CTRL_CMD_NEWFAMILY) < 0)
706                                 goto errout;
707                 }
708
709                 fams_to_skip = 0;
710         }
711
712 errout:
713         cb->args[0] = i;
714         cb->args[1] = n;
715
716         return skb->len;
717 }
718
719 static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
720                                              u32 pid, int seq, u8 cmd)
721 {
722         struct sk_buff *skb;
723         int err;
724
725         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
726         if (skb == NULL)
727                 return ERR_PTR(-ENOBUFS);
728
729         err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
730         if (err < 0) {
731                 nlmsg_free(skb);
732                 return ERR_PTR(err);
733         }
734
735         return skb;
736 }
737
738 static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
739                                             u32 pid, int seq, u8 cmd)
740 {
741         struct sk_buff *skb;
742         int err;
743
744         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
745         if (skb == NULL)
746                 return ERR_PTR(-ENOBUFS);
747
748         err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd);
749         if (err < 0) {
750                 nlmsg_free(skb);
751                 return ERR_PTR(err);
752         }
753
754         return skb;
755 }
756
757 static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
758         [CTRL_ATTR_FAMILY_ID]   = { .type = NLA_U16 },
759         [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
760                                     .len = GENL_NAMSIZ - 1 },
761 };
762
763 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
764 {
765         struct sk_buff *msg;
766         struct genl_family *res = NULL;
767         int err = -EINVAL;
768
769         if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
770                 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
771                 res = genl_family_find_byid(id);
772                 err = -ENOENT;
773         }
774
775         if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
776                 char *name;
777
778                 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
779                 res = genl_family_find_byname(name);
780                 err = -ENOENT;
781         }
782
783         if (res == NULL)
784                 return err;
785
786         if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
787                 /* family doesn't exist here */
788                 return -ENOENT;
789         }
790
791         msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
792                                     CTRL_CMD_NEWFAMILY);
793         if (IS_ERR(msg))
794                 return PTR_ERR(msg);
795
796         return genlmsg_reply(msg, info);
797 }
798
799 static int genl_ctrl_event(int event, void *data)
800 {
801         struct sk_buff *msg;
802         struct genl_family *family;
803         struct genl_multicast_group *grp;
804
805         /* genl is still initialising */
806         if (!init_net.genl_sock)
807                 return 0;
808
809         switch (event) {
810         case CTRL_CMD_NEWFAMILY:
811         case CTRL_CMD_DELFAMILY:
812                 family = data;
813                 msg = ctrl_build_family_msg(family, 0, 0, event);
814                 break;
815         case CTRL_CMD_NEWMCAST_GRP:
816         case CTRL_CMD_DELMCAST_GRP:
817                 grp = data;
818                 family = grp->family;
819                 msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
820                 break;
821         default:
822                 return -EINVAL;
823         }
824
825         if (IS_ERR(msg))
826                 return PTR_ERR(msg);
827
828         if (!family->netnsok) {
829                 genlmsg_multicast_netns(&init_net, msg, 0,
830                                         GENL_ID_CTRL, GFP_KERNEL);
831         } else {
832                 rcu_read_lock();
833                 genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC);
834                 rcu_read_unlock();
835         }
836
837         return 0;
838 }
839
840 static struct genl_ops genl_ctrl_ops = {
841         .cmd            = CTRL_CMD_GETFAMILY,
842         .doit           = ctrl_getfamily,
843         .dumpit         = ctrl_dumpfamily,
844         .policy         = ctrl_policy,
845 };
846
847 static struct genl_multicast_group notify_grp = {
848         .name           = "notify",
849 };
850
851 static int __net_init genl_pernet_init(struct net *net)
852 {
853         /* we'll bump the group number right afterwards */
854         net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, 0,
855                                                genl_rcv, &genl_mutex,
856                                                THIS_MODULE);
857
858         if (!net->genl_sock && net_eq(net, &init_net))
859                 panic("GENL: Cannot initialize generic netlink\n");
860
861         if (!net->genl_sock)
862                 return -ENOMEM;
863
864         return 0;
865 }
866
867 static void __net_exit genl_pernet_exit(struct net *net)
868 {
869         netlink_kernel_release(net->genl_sock);
870         net->genl_sock = NULL;
871 }
872
873 static struct pernet_operations genl_pernet_ops = {
874         .init = genl_pernet_init,
875         .exit = genl_pernet_exit,
876 };
877
878 static int __init genl_init(void)
879 {
880         int i, err;
881
882         for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
883                 INIT_LIST_HEAD(&family_ht[i]);
884
885         err = genl_register_family(&genl_ctrl);
886         if (err < 0)
887                 goto problem;
888
889         err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
890         if (err < 0)
891                 goto problem;
892
893         netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
894
895         err = register_pernet_subsys(&genl_pernet_ops);
896         if (err)
897                 goto problem;
898
899         err = genl_register_mc_group(&genl_ctrl, &notify_grp);
900         if (err < 0)
901                 goto problem;
902
903         return 0;
904
905 problem:
906         panic("GENL: Cannot register controller: %d\n", err);
907 }
908
909 subsys_initcall(genl_init);
910
911 EXPORT_SYMBOL(genl_register_ops);
912 EXPORT_SYMBOL(genl_unregister_ops);
913 EXPORT_SYMBOL(genl_register_family);
914 EXPORT_SYMBOL(genl_unregister_family);
915
916 static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
917                          gfp_t flags)
918 {
919         struct sk_buff *tmp;
920         struct net *net, *prev = NULL;
921         int err;
922
923         for_each_net_rcu(net) {
924                 if (prev) {
925                         tmp = skb_clone(skb, flags);
926                         if (!tmp) {
927                                 err = -ENOMEM;
928                                 goto error;
929                         }
930                         err = nlmsg_multicast(prev->genl_sock, tmp,
931                                               pid, group, flags);
932                         if (err)
933                                 goto error;
934                 }
935
936                 prev = net;
937         }
938
939         return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags);
940  error:
941         kfree_skb(skb);
942         return err;
943 }
944
945 int genlmsg_multicast_allns(struct sk_buff *skb, u32 pid, unsigned int group,
946                             gfp_t flags)
947 {
948         return genlmsg_mcast(skb, pid, group, flags);
949 }
950 EXPORT_SYMBOL(genlmsg_multicast_allns);