Commit | Line | Data |
---|---|---|
482a8524 TG |
1 | /* |
2 | * NETLINK Generic Netlink Family | |
3 | * | |
4 | * Authors: Jamal Hadi Salim | |
5 | * Thomas Graf <tgraf@suug.ch> | |
2dbba6f7 | 6 | * Johannes Berg <johannes@sipsolutions.net> |
482a8524 TG |
7 | */ |
8 | ||
482a8524 TG |
9 | #include <linux/module.h> |
10 | #include <linux/kernel.h> | |
5a0e3ad6 | 11 | #include <linux/slab.h> |
482a8524 TG |
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> | |
14cc3e2b | 17 | #include <linux/mutex.h> |
2dbba6f7 | 18 | #include <linux/bitmap.h> |
def31174 | 19 | #include <linux/rwsem.h> |
482a8524 TG |
20 | #include <net/sock.h> |
21 | #include <net/genetlink.h> | |
22 | ||
14cc3e2b | 23 | static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */ |
def31174 | 24 | static DECLARE_RWSEM(cb_lock); |
482a8524 | 25 | |
f408e0ce | 26 | void genl_lock(void) |
482a8524 | 27 | { |
14cc3e2b | 28 | mutex_lock(&genl_mutex); |
482a8524 | 29 | } |
f408e0ce | 30 | EXPORT_SYMBOL(genl_lock); |
482a8524 | 31 | |
f408e0ce | 32 | void genl_unlock(void) |
482a8524 | 33 | { |
14cc3e2b | 34 | mutex_unlock(&genl_mutex); |
482a8524 | 35 | } |
f408e0ce | 36 | EXPORT_SYMBOL(genl_unlock); |
482a8524 | 37 | |
320f5ea0 | 38 | #ifdef CONFIG_LOCKDEP |
86b1309c PS |
39 | int lockdep_genl_is_held(void) |
40 | { | |
41 | return lockdep_is_held(&genl_mutex); | |
42 | } | |
43 | EXPORT_SYMBOL(lockdep_genl_is_held); | |
44 | #endif | |
45 | ||
def31174 PS |
46 | static void genl_lock_all(void) |
47 | { | |
48 | down_write(&cb_lock); | |
49 | genl_lock(); | |
50 | } | |
51 | ||
52 | static void genl_unlock_all(void) | |
53 | { | |
54 | genl_unlock(); | |
55 | up_write(&cb_lock); | |
56 | } | |
57 | ||
482a8524 TG |
58 | #define GENL_FAM_TAB_SIZE 16 |
59 | #define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1) | |
60 | ||
61 | static struct list_head family_ht[GENL_FAM_TAB_SIZE]; | |
2dbba6f7 JB |
62 | /* |
63 | * Bitmap of multicast groups that are currently in use. | |
64 | * | |
65 | * To avoid an allocation at boot of just one unsigned long, | |
66 | * declare it global instead. | |
67 | * Bit 0 is marked as already used since group 0 is invalid. | |
e5dcecba JB |
68 | * Bit 1 is marked as already used since the drop-monitor code |
69 | * abuses the API and thinks it can statically use group 1. | |
70 | * That group will typically conflict with other groups that | |
71 | * any proper users use. | |
2dbba6f7 | 72 | */ |
e5dcecba | 73 | static unsigned long mc_group_start = 0x3; |
2dbba6f7 JB |
74 | static unsigned long *mc_groups = &mc_group_start; |
75 | static unsigned long mc_groups_longs = 1; | |
482a8524 TG |
76 | |
77 | static int genl_ctrl_event(int event, void *data); | |
78 | ||
79 | static inline unsigned int genl_family_hash(unsigned int id) | |
80 | { | |
81 | return id & GENL_FAM_TAB_MASK; | |
82 | } | |
83 | ||
84 | static inline struct list_head *genl_family_chain(unsigned int id) | |
85 | { | |
86 | return &family_ht[genl_family_hash(id)]; | |
87 | } | |
88 | ||
89 | static struct genl_family *genl_family_find_byid(unsigned int id) | |
90 | { | |
91 | struct genl_family *f; | |
92 | ||
93 | list_for_each_entry(f, genl_family_chain(id), family_list) | |
94 | if (f->id == id) | |
95 | return f; | |
96 | ||
97 | return NULL; | |
98 | } | |
99 | ||
100 | static struct genl_family *genl_family_find_byname(char *name) | |
101 | { | |
102 | struct genl_family *f; | |
103 | int i; | |
104 | ||
105 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | |
106 | list_for_each_entry(f, genl_family_chain(i), family_list) | |
107 | if (strcmp(f->name, name) == 0) | |
108 | return f; | |
109 | ||
110 | return NULL; | |
111 | } | |
112 | ||
f84f771d | 113 | static const struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) |
482a8524 | 114 | { |
d91824c0 | 115 | int i; |
482a8524 | 116 | |
d91824c0 JB |
117 | for (i = 0; i < family->n_ops; i++) |
118 | if (family->ops[i].cmd == cmd) | |
119 | return &family->ops[i]; | |
482a8524 TG |
120 | |
121 | return NULL; | |
122 | } | |
123 | ||
124 | /* Of course we are going to have problems once we hit | |
125 | * 2^16 alive types, but that can only happen by year 2K | |
126 | */ | |
b57ef81f | 127 | static u16 genl_generate_id(void) |
482a8524 | 128 | { |
988ade6b KK |
129 | static u16 id_gen_idx = GENL_MIN_ID; |
130 | int i; | |
482a8524 | 131 | |
988ade6b KK |
132 | for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) { |
133 | if (!genl_family_find_byid(id_gen_idx)) | |
134 | return id_gen_idx; | |
135 | if (++id_gen_idx > GENL_MAX_ID) | |
482a8524 | 136 | id_gen_idx = GENL_MIN_ID; |
988ade6b | 137 | } |
482a8524 | 138 | |
988ade6b | 139 | return 0; |
482a8524 TG |
140 | } |
141 | ||
2dbba6f7 JB |
142 | static struct genl_multicast_group notify_grp; |
143 | ||
144 | /** | |
145 | * genl_register_mc_group - register a multicast group | |
146 | * | |
147 | * Registers the specified multicast group and notifies userspace | |
148 | * about the new group. | |
149 | * | |
150 | * Returns 0 on success or a negative error code. | |
151 | * | |
152 | * @family: The generic netlink family the group shall be registered for. | |
153 | * @grp: The group to register, must have a name. | |
154 | */ | |
155 | int genl_register_mc_group(struct genl_family *family, | |
156 | struct genl_multicast_group *grp) | |
157 | { | |
158 | int id; | |
159 | unsigned long *new_groups; | |
b1f57195 | 160 | int err = 0; |
2dbba6f7 JB |
161 | |
162 | BUG_ON(grp->name[0] == '\0'); | |
f1e79e20 | 163 | BUG_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL); |
2dbba6f7 | 164 | |
def31174 | 165 | genl_lock_all(); |
2dbba6f7 | 166 | |
e5dcecba | 167 | /* special-case our own group and hacks */ |
2dbba6f7 JB |
168 | if (grp == ¬ify_grp) |
169 | id = GENL_ID_CTRL; | |
e5dcecba JB |
170 | else if (strcmp(family->name, "NET_DM") == 0) |
171 | id = 1; | |
2dbba6f7 JB |
172 | else |
173 | id = find_first_zero_bit(mc_groups, | |
174 | mc_groups_longs * BITS_PER_LONG); | |
175 | ||
176 | ||
177 | if (id >= mc_groups_longs * BITS_PER_LONG) { | |
178 | size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long); | |
179 | ||
180 | if (mc_groups == &mc_group_start) { | |
181 | new_groups = kzalloc(nlen, GFP_KERNEL); | |
182 | if (!new_groups) { | |
183 | err = -ENOMEM; | |
184 | goto out; | |
185 | } | |
186 | mc_groups = new_groups; | |
187 | *mc_groups = mc_group_start; | |
188 | } else { | |
189 | new_groups = krealloc(mc_groups, nlen, GFP_KERNEL); | |
190 | if (!new_groups) { | |
191 | err = -ENOMEM; | |
192 | goto out; | |
193 | } | |
194 | mc_groups = new_groups; | |
195 | mc_groups[mc_groups_longs] = 0; | |
196 | } | |
197 | mc_groups_longs++; | |
198 | } | |
199 | ||
134e6375 JB |
200 | if (family->netnsok) { |
201 | struct net *net; | |
202 | ||
d136f1bd | 203 | netlink_table_grab(); |
134e6375 JB |
204 | rcu_read_lock(); |
205 | for_each_net_rcu(net) { | |
d136f1bd | 206 | err = __netlink_change_ngroups(net->genl_sock, |
134e6375 JB |
207 | mc_groups_longs * BITS_PER_LONG); |
208 | if (err) { | |
209 | /* | |
210 | * No need to roll back, can only fail if | |
211 | * memory allocation fails and then the | |
212 | * number of _possible_ groups has been | |
213 | * increased on some sockets which is ok. | |
214 | */ | |
215 | rcu_read_unlock(); | |
d136f1bd | 216 | netlink_table_ungrab(); |
134e6375 JB |
217 | goto out; |
218 | } | |
219 | } | |
220 | rcu_read_unlock(); | |
d136f1bd | 221 | netlink_table_ungrab(); |
134e6375 JB |
222 | } else { |
223 | err = netlink_change_ngroups(init_net.genl_sock, | |
224 | mc_groups_longs * BITS_PER_LONG); | |
225 | if (err) | |
226 | goto out; | |
227 | } | |
2dbba6f7 JB |
228 | |
229 | grp->id = id; | |
230 | set_bit(id, mc_groups); | |
231 | list_add_tail(&grp->list, &family->mcast_groups); | |
232 | grp->family = family; | |
233 | ||
234 | genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp); | |
235 | out: | |
def31174 | 236 | genl_unlock_all(); |
79d310d0 | 237 | return err; |
2dbba6f7 JB |
238 | } |
239 | EXPORT_SYMBOL(genl_register_mc_group); | |
240 | ||
79dc4386 TG |
241 | static void __genl_unregister_mc_group(struct genl_family *family, |
242 | struct genl_multicast_group *grp) | |
243 | { | |
134e6375 | 244 | struct net *net; |
79dc4386 | 245 | BUG_ON(grp->family != family); |
134e6375 | 246 | |
b8273570 | 247 | netlink_table_grab(); |
134e6375 JB |
248 | rcu_read_lock(); |
249 | for_each_net_rcu(net) | |
b8273570 | 250 | __netlink_clear_multicast_users(net->genl_sock, grp->id); |
134e6375 | 251 | rcu_read_unlock(); |
b8273570 | 252 | netlink_table_ungrab(); |
134e6375 | 253 | |
e5dcecba JB |
254 | if (grp->id != 1) |
255 | clear_bit(grp->id, mc_groups); | |
79dc4386 TG |
256 | list_del(&grp->list); |
257 | genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp); | |
258 | grp->id = 0; | |
259 | grp->family = NULL; | |
260 | } | |
261 | ||
2dbba6f7 JB |
262 | /** |
263 | * genl_unregister_mc_group - unregister a multicast group | |
264 | * | |
265 | * Unregisters the specified multicast group and notifies userspace | |
266 | * about it. All current listeners on the group are removed. | |
267 | * | |
268 | * Note: It is not necessary to unregister all multicast groups before | |
269 | * unregistering the family, unregistering the family will cause | |
270 | * all assigned multicast groups to be unregistered automatically. | |
271 | * | |
272 | * @family: Generic netlink family the group belongs to. | |
273 | * @grp: The group to unregister, must have been registered successfully | |
274 | * previously. | |
275 | */ | |
276 | void genl_unregister_mc_group(struct genl_family *family, | |
277 | struct genl_multicast_group *grp) | |
278 | { | |
def31174 | 279 | genl_lock_all(); |
79dc4386 | 280 | __genl_unregister_mc_group(family, grp); |
def31174 | 281 | genl_unlock_all(); |
2dbba6f7 | 282 | } |
3efb40c2 | 283 | EXPORT_SYMBOL(genl_unregister_mc_group); |
2dbba6f7 JB |
284 | |
285 | static void genl_unregister_mc_groups(struct genl_family *family) | |
286 | { | |
287 | struct genl_multicast_group *grp, *tmp; | |
288 | ||
289 | list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list) | |
79dc4386 | 290 | __genl_unregister_mc_group(family, grp); |
2dbba6f7 JB |
291 | } |
292 | ||
568508aa | 293 | static int genl_validate_ops(struct genl_family *family) |
482a8524 | 294 | { |
568508aa JB |
295 | const struct genl_ops *ops = family->ops; |
296 | unsigned int n_ops = family->n_ops; | |
d91824c0 JB |
297 | int i, j; |
298 | ||
568508aa JB |
299 | if (WARN_ON(n_ops && !ops)) |
300 | return -EINVAL; | |
301 | ||
302 | if (!n_ops) | |
303 | return 0; | |
304 | ||
d91824c0 JB |
305 | for (i = 0; i < n_ops; i++) { |
306 | if (ops[i].dumpit == NULL && ops[i].doit == NULL) | |
307 | return -EINVAL; | |
308 | for (j = i + 1; j < n_ops; j++) | |
309 | if (ops[i].cmd == ops[j].cmd) | |
310 | return -EINVAL; | |
482a8524 TG |
311 | } |
312 | ||
d91824c0 JB |
313 | /* family is not registered yet, so no locking needed */ |
314 | family->ops = ops; | |
315 | family->n_ops = n_ops; | |
482a8524 | 316 | |
d91824c0 | 317 | return 0; |
482a8524 | 318 | } |
482a8524 TG |
319 | |
320 | /** | |
33c6b1f6 | 321 | * __genl_register_family - register a generic netlink family |
482a8524 TG |
322 | * @family: generic netlink family |
323 | * | |
324 | * Registers the specified family after validating it first. Only one | |
325 | * family may be registered with the same family name or identifier. | |
326 | * The family id may equal GENL_ID_GENERATE causing an unique id to | |
327 | * be automatically generated and assigned. | |
328 | * | |
568508aa JB |
329 | * The family's ops array must already be assigned, you can use the |
330 | * genl_register_family_with_ops() helper function. | |
331 | * | |
482a8524 TG |
332 | * Return 0 on success or a negative error code. |
333 | */ | |
33c6b1f6 | 334 | int __genl_register_family(struct genl_family *family) |
482a8524 TG |
335 | { |
336 | int err = -EINVAL; | |
337 | ||
338 | if (family->id && family->id < GENL_MIN_ID) | |
339 | goto errout; | |
340 | ||
341 | if (family->id > GENL_MAX_ID) | |
342 | goto errout; | |
343 | ||
568508aa JB |
344 | err = genl_validate_ops(family); |
345 | if (err) | |
346 | return err; | |
347 | ||
2dbba6f7 | 348 | INIT_LIST_HEAD(&family->mcast_groups); |
482a8524 | 349 | |
def31174 | 350 | genl_lock_all(); |
482a8524 TG |
351 | |
352 | if (genl_family_find_byname(family->name)) { | |
353 | err = -EEXIST; | |
354 | goto errout_locked; | |
355 | } | |
356 | ||
482a8524 TG |
357 | if (family->id == GENL_ID_GENERATE) { |
358 | u16 newid = genl_generate_id(); | |
359 | ||
360 | if (!newid) { | |
361 | err = -ENOMEM; | |
362 | goto errout_locked; | |
363 | } | |
364 | ||
365 | family->id = newid; | |
93860b08 KK |
366 | } else if (genl_family_find_byid(family->id)) { |
367 | err = -EEXIST; | |
368 | goto errout_locked; | |
482a8524 TG |
369 | } |
370 | ||
def31174 | 371 | if (family->maxattr && !family->parallel_ops) { |
482a8524 TG |
372 | family->attrbuf = kmalloc((family->maxattr+1) * |
373 | sizeof(struct nlattr *), GFP_KERNEL); | |
374 | if (family->attrbuf == NULL) { | |
375 | err = -ENOMEM; | |
e200bd80 | 376 | goto errout_locked; |
482a8524 TG |
377 | } |
378 | } else | |
379 | family->attrbuf = NULL; | |
380 | ||
381 | list_add_tail(&family->family_list, genl_family_chain(family->id)); | |
def31174 | 382 | genl_unlock_all(); |
482a8524 TG |
383 | |
384 | genl_ctrl_event(CTRL_CMD_NEWFAMILY, family); | |
385 | ||
386 | return 0; | |
387 | ||
388 | errout_locked: | |
def31174 | 389 | genl_unlock_all(); |
482a8524 TG |
390 | errout: |
391 | return err; | |
392 | } | |
33c6b1f6 | 393 | EXPORT_SYMBOL(__genl_register_family); |
482a8524 TG |
394 | |
395 | /** | |
396 | * genl_unregister_family - unregister generic netlink family | |
397 | * @family: generic netlink family | |
398 | * | |
399 | * Unregisters the specified family. | |
400 | * | |
401 | * Returns 0 on success or a negative error code. | |
402 | */ | |
403 | int genl_unregister_family(struct genl_family *family) | |
404 | { | |
405 | struct genl_family *rc; | |
406 | ||
def31174 | 407 | genl_lock_all(); |
482a8524 | 408 | |
910d6c32 PE |
409 | genl_unregister_mc_groups(family); |
410 | ||
482a8524 TG |
411 | list_for_each_entry(rc, genl_family_chain(family->id), family_list) { |
412 | if (family->id != rc->id || strcmp(rc->name, family->name)) | |
413 | continue; | |
414 | ||
415 | list_del(&rc->family_list); | |
d91824c0 | 416 | family->n_ops = 0; |
def31174 | 417 | genl_unlock_all(); |
482a8524 | 418 | |
482a8524 TG |
419 | kfree(family->attrbuf); |
420 | genl_ctrl_event(CTRL_CMD_DELFAMILY, family); | |
421 | return 0; | |
422 | } | |
423 | ||
def31174 | 424 | genl_unlock_all(); |
482a8524 TG |
425 | |
426 | return -ENOENT; | |
427 | } | |
416c2f9c | 428 | EXPORT_SYMBOL(genl_unregister_family); |
482a8524 | 429 | |
a46621a3 DV |
430 | /** |
431 | * genlmsg_put - Add generic netlink header to netlink message | |
432 | * @skb: socket buffer holding the message | |
15e47304 | 433 | * @portid: netlink portid the message is addressed to |
a46621a3 DV |
434 | * @seq: sequence number (usually the one of the sender) |
435 | * @family: generic netlink family | |
2c53040f | 436 | * @flags: netlink message flags |
a46621a3 DV |
437 | * @cmd: generic netlink command |
438 | * | |
439 | * Returns pointer to user specific header | |
440 | */ | |
15e47304 | 441 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
a46621a3 DV |
442 | struct genl_family *family, int flags, u8 cmd) |
443 | { | |
444 | struct nlmsghdr *nlh; | |
445 | struct genlmsghdr *hdr; | |
446 | ||
15e47304 | 447 | nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN + |
a46621a3 DV |
448 | family->hdrsize, flags); |
449 | if (nlh == NULL) | |
450 | return NULL; | |
451 | ||
452 | hdr = nlmsg_data(nlh); | |
453 | hdr->cmd = cmd; | |
454 | hdr->version = family->version; | |
455 | hdr->reserved = 0; | |
456 | ||
457 | return (char *) hdr + GENL_HDRLEN; | |
458 | } | |
459 | EXPORT_SYMBOL(genlmsg_put); | |
460 | ||
9b96309c PS |
461 | static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) |
462 | { | |
f84f771d JB |
463 | /* our ops are always const - netlink API doesn't propagate that */ |
464 | const struct genl_ops *ops = cb->data; | |
9b96309c PS |
465 | int rc; |
466 | ||
467 | genl_lock(); | |
468 | rc = ops->dumpit(skb, cb); | |
469 | genl_unlock(); | |
470 | return rc; | |
471 | } | |
472 | ||
473 | static int genl_lock_done(struct netlink_callback *cb) | |
474 | { | |
f84f771d JB |
475 | /* our ops are always const - netlink API doesn't propagate that */ |
476 | const struct genl_ops *ops = cb->data; | |
9b96309c PS |
477 | int rc = 0; |
478 | ||
479 | if (ops->done) { | |
480 | genl_lock(); | |
481 | rc = ops->done(cb); | |
482 | genl_unlock(); | |
483 | } | |
484 | return rc; | |
485 | } | |
486 | ||
def31174 PS |
487 | static int genl_family_rcv_msg(struct genl_family *family, |
488 | struct sk_buff *skb, | |
489 | struct nlmsghdr *nlh) | |
482a8524 | 490 | { |
f84f771d | 491 | const struct genl_ops *ops; |
134e6375 | 492 | struct net *net = sock_net(skb->sk); |
482a8524 TG |
493 | struct genl_info info; |
494 | struct genlmsghdr *hdr = nlmsg_data(nlh); | |
def31174 | 495 | struct nlattr **attrbuf; |
1d00a4eb | 496 | int hdrlen, err; |
482a8524 | 497 | |
134e6375 JB |
498 | /* this family doesn't exist in this netns */ |
499 | if (!family->netnsok && !net_eq(net, &init_net)) | |
500 | return -ENOENT; | |
501 | ||
482a8524 TG |
502 | hdrlen = GENL_HDRLEN + family->hdrsize; |
503 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
1d00a4eb | 504 | return -EINVAL; |
482a8524 TG |
505 | |
506 | ops = genl_get_cmd(hdr->cmd, family); | |
1d00a4eb TG |
507 | if (ops == NULL) |
508 | return -EOPNOTSUPP; | |
482a8524 | 509 | |
1d00a4eb | 510 | if ((ops->flags & GENL_ADMIN_PERM) && |
fd778461 | 511 | !capable(CAP_NET_ADMIN)) |
1d00a4eb | 512 | return -EPERM; |
482a8524 | 513 | |
e1ee3673 | 514 | if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) { |
9b96309c | 515 | int rc; |
def31174 | 516 | |
1d00a4eb TG |
517 | if (ops->dumpit == NULL) |
518 | return -EOPNOTSUPP; | |
482a8524 | 519 | |
9b96309c PS |
520 | if (!family->parallel_ops) { |
521 | struct netlink_dump_control c = { | |
33c6b1f6 | 522 | .module = family->module, |
f84f771d JB |
523 | /* we have const, but the netlink API doesn't */ |
524 | .data = (void *)ops, | |
9b96309c PS |
525 | .dump = genl_lock_dumpit, |
526 | .done = genl_lock_done, | |
527 | }; | |
528 | ||
529 | genl_unlock(); | |
33c6b1f6 | 530 | rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c); |
9b96309c PS |
531 | genl_lock(); |
532 | ||
533 | } else { | |
534 | struct netlink_dump_control c = { | |
33c6b1f6 | 535 | .module = family->module, |
9b96309c PS |
536 | .dump = ops->dumpit, |
537 | .done = ops->done, | |
538 | }; | |
539 | ||
33c6b1f6 | 540 | rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c); |
9b96309c PS |
541 | } |
542 | ||
543 | return rc; | |
482a8524 TG |
544 | } |
545 | ||
1d00a4eb TG |
546 | if (ops->doit == NULL) |
547 | return -EOPNOTSUPP; | |
482a8524 | 548 | |
def31174 PS |
549 | if (family->maxattr && family->parallel_ops) { |
550 | attrbuf = kmalloc((family->maxattr+1) * | |
551 | sizeof(struct nlattr *), GFP_KERNEL); | |
552 | if (attrbuf == NULL) | |
553 | return -ENOMEM; | |
554 | } else | |
555 | attrbuf = family->attrbuf; | |
556 | ||
557 | if (attrbuf) { | |
558 | err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr, | |
482a8524 TG |
559 | ops->policy); |
560 | if (err < 0) | |
50754d21 | 561 | goto out; |
482a8524 TG |
562 | } |
563 | ||
564 | info.snd_seq = nlh->nlmsg_seq; | |
15e47304 | 565 | info.snd_portid = NETLINK_CB(skb).portid; |
482a8524 TG |
566 | info.nlhdr = nlh; |
567 | info.genlhdr = nlmsg_data(nlh); | |
568 | info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; | |
def31174 | 569 | info.attrs = attrbuf; |
134e6375 | 570 | genl_info_net_set(&info, net); |
ff4c92d8 | 571 | memset(&info.user_ptr, 0, sizeof(info.user_ptr)); |
482a8524 | 572 | |
ff4c92d8 JB |
573 | if (family->pre_doit) { |
574 | err = family->pre_doit(ops, skb, &info); | |
575 | if (err) | |
50754d21 | 576 | goto out; |
ff4c92d8 JB |
577 | } |
578 | ||
579 | err = ops->doit(skb, &info); | |
580 | ||
581 | if (family->post_doit) | |
582 | family->post_doit(ops, skb, &info); | |
583 | ||
50754d21 | 584 | out: |
def31174 PS |
585 | if (family->parallel_ops) |
586 | kfree(attrbuf); | |
587 | ||
588 | return err; | |
589 | } | |
590 | ||
591 | static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) | |
592 | { | |
593 | struct genl_family *family; | |
594 | int err; | |
595 | ||
596 | family = genl_family_find_byid(nlh->nlmsg_type); | |
597 | if (family == NULL) | |
598 | return -ENOENT; | |
599 | ||
600 | if (!family->parallel_ops) | |
601 | genl_lock(); | |
602 | ||
603 | err = genl_family_rcv_msg(family, skb, nlh); | |
604 | ||
605 | if (!family->parallel_ops) | |
606 | genl_unlock(); | |
607 | ||
ff4c92d8 | 608 | return err; |
482a8524 TG |
609 | } |
610 | ||
cd40b7d3 | 611 | static void genl_rcv(struct sk_buff *skb) |
482a8524 | 612 | { |
def31174 | 613 | down_read(&cb_lock); |
cd40b7d3 | 614 | netlink_rcv_skb(skb, &genl_rcv_msg); |
def31174 | 615 | up_read(&cb_lock); |
482a8524 TG |
616 | } |
617 | ||
618 | /************************************************************************** | |
619 | * Controller | |
620 | **************************************************************************/ | |
621 | ||
17c157c8 TG |
622 | static struct genl_family genl_ctrl = { |
623 | .id = GENL_ID_CTRL, | |
624 | .name = "nlctrl", | |
334c29a6 | 625 | .version = 0x2, |
17c157c8 | 626 | .maxattr = CTRL_ATTR_MAX, |
134e6375 | 627 | .netnsok = true, |
17c157c8 TG |
628 | }; |
629 | ||
15e47304 | 630 | static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq, |
482a8524 TG |
631 | u32 flags, struct sk_buff *skb, u8 cmd) |
632 | { | |
633 | void *hdr; | |
634 | ||
15e47304 | 635 | hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd); |
482a8524 TG |
636 | if (hdr == NULL) |
637 | return -1; | |
638 | ||
444653f6 DM |
639 | if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) || |
640 | nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) || | |
641 | nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) || | |
642 | nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) || | |
643 | nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr)) | |
644 | goto nla_put_failure; | |
eb328111 | 645 | |
d91824c0 | 646 | if (family->n_ops) { |
e94ef682 | 647 | struct nlattr *nla_ops; |
d91824c0 | 648 | int i; |
eb328111 | 649 | |
e94ef682 TG |
650 | nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS); |
651 | if (nla_ops == NULL) | |
eb328111 TG |
652 | goto nla_put_failure; |
653 | ||
d91824c0 | 654 | for (i = 0; i < family->n_ops; i++) { |
e94ef682 | 655 | struct nlattr *nest; |
f84f771d | 656 | const struct genl_ops *ops = &family->ops[i]; |
029b234f | 657 | u32 op_flags = ops->flags; |
f84f771d JB |
658 | |
659 | if (ops->dumpit) | |
029b234f | 660 | op_flags |= GENL_CMD_CAP_DUMP; |
f84f771d | 661 | if (ops->doit) |
029b234f | 662 | op_flags |= GENL_CMD_CAP_DO; |
f84f771d | 663 | if (ops->policy) |
029b234f | 664 | op_flags |= GENL_CMD_CAP_HASPOL; |
eb328111 | 665 | |
d91824c0 | 666 | nest = nla_nest_start(skb, i + 1); |
e94ef682 TG |
667 | if (nest == NULL) |
668 | goto nla_put_failure; | |
eb328111 | 669 | |
444653f6 | 670 | if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) || |
029b234f | 671 | nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags)) |
444653f6 | 672 | goto nla_put_failure; |
eb328111 | 673 | |
e94ef682 TG |
674 | nla_nest_end(skb, nest); |
675 | } | |
676 | ||
677 | nla_nest_end(skb, nla_ops); | |
678 | } | |
482a8524 | 679 | |
2dbba6f7 JB |
680 | if (!list_empty(&family->mcast_groups)) { |
681 | struct genl_multicast_group *grp; | |
682 | struct nlattr *nla_grps; | |
683 | int idx = 1; | |
684 | ||
685 | nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); | |
686 | if (nla_grps == NULL) | |
687 | goto nla_put_failure; | |
688 | ||
689 | list_for_each_entry(grp, &family->mcast_groups, list) { | |
690 | struct nlattr *nest; | |
691 | ||
692 | nest = nla_nest_start(skb, idx++); | |
693 | if (nest == NULL) | |
694 | goto nla_put_failure; | |
695 | ||
444653f6 DM |
696 | if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) || |
697 | nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME, | |
698 | grp->name)) | |
699 | goto nla_put_failure; | |
2dbba6f7 JB |
700 | |
701 | nla_nest_end(skb, nest); | |
702 | } | |
703 | nla_nest_end(skb, nla_grps); | |
704 | } | |
705 | ||
706 | return genlmsg_end(skb, hdr); | |
707 | ||
708 | nla_put_failure: | |
bc3ed28c TG |
709 | genlmsg_cancel(skb, hdr); |
710 | return -EMSGSIZE; | |
2dbba6f7 JB |
711 | } |
712 | ||
15e47304 | 713 | static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 portid, |
2dbba6f7 JB |
714 | u32 seq, u32 flags, struct sk_buff *skb, |
715 | u8 cmd) | |
716 | { | |
717 | void *hdr; | |
718 | struct nlattr *nla_grps; | |
719 | struct nlattr *nest; | |
720 | ||
15e47304 | 721 | hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd); |
2dbba6f7 JB |
722 | if (hdr == NULL) |
723 | return -1; | |
724 | ||
444653f6 DM |
725 | if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name) || |
726 | nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id)) | |
727 | goto nla_put_failure; | |
2dbba6f7 JB |
728 | |
729 | nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); | |
730 | if (nla_grps == NULL) | |
731 | goto nla_put_failure; | |
732 | ||
733 | nest = nla_nest_start(skb, 1); | |
734 | if (nest == NULL) | |
735 | goto nla_put_failure; | |
736 | ||
444653f6 DM |
737 | if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) || |
738 | nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME, | |
739 | grp->name)) | |
740 | goto nla_put_failure; | |
2dbba6f7 JB |
741 | |
742 | nla_nest_end(skb, nest); | |
743 | nla_nest_end(skb, nla_grps); | |
744 | ||
482a8524 TG |
745 | return genlmsg_end(skb, hdr); |
746 | ||
747 | nla_put_failure: | |
bc3ed28c TG |
748 | genlmsg_cancel(skb, hdr); |
749 | return -EMSGSIZE; | |
482a8524 TG |
750 | } |
751 | ||
752 | static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) | |
753 | { | |
754 | ||
755 | int i, n = 0; | |
756 | struct genl_family *rt; | |
134e6375 | 757 | struct net *net = sock_net(skb->sk); |
482a8524 TG |
758 | int chains_to_skip = cb->args[0]; |
759 | int fams_to_skip = cb->args[1]; | |
760 | ||
e1d5a010 | 761 | for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) { |
482a8524 TG |
762 | n = 0; |
763 | list_for_each_entry(rt, genl_family_chain(i), family_list) { | |
134e6375 JB |
764 | if (!rt->netnsok && !net_eq(net, &init_net)) |
765 | continue; | |
482a8524 TG |
766 | if (++n < fams_to_skip) |
767 | continue; | |
15e47304 | 768 | if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid, |
482a8524 TG |
769 | cb->nlh->nlmsg_seq, NLM_F_MULTI, |
770 | skb, CTRL_CMD_NEWFAMILY) < 0) | |
771 | goto errout; | |
772 | } | |
773 | ||
774 | fams_to_skip = 0; | |
775 | } | |
776 | ||
777 | errout: | |
778 | cb->args[0] = i; | |
779 | cb->args[1] = n; | |
780 | ||
781 | return skb->len; | |
782 | } | |
783 | ||
2dbba6f7 | 784 | static struct sk_buff *ctrl_build_family_msg(struct genl_family *family, |
15e47304 | 785 | u32 portid, int seq, u8 cmd) |
482a8524 TG |
786 | { |
787 | struct sk_buff *skb; | |
788 | int err; | |
789 | ||
339bf98f | 790 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
482a8524 TG |
791 | if (skb == NULL) |
792 | return ERR_PTR(-ENOBUFS); | |
793 | ||
15e47304 | 794 | err = ctrl_fill_info(family, portid, seq, 0, skb, cmd); |
482a8524 TG |
795 | if (err < 0) { |
796 | nlmsg_free(skb); | |
797 | return ERR_PTR(err); | |
798 | } | |
799 | ||
800 | return skb; | |
801 | } | |
802 | ||
2dbba6f7 | 803 | static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp, |
15e47304 | 804 | u32 portid, int seq, u8 cmd) |
2dbba6f7 JB |
805 | { |
806 | struct sk_buff *skb; | |
807 | int err; | |
808 | ||
809 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
810 | if (skb == NULL) | |
811 | return ERR_PTR(-ENOBUFS); | |
812 | ||
15e47304 | 813 | err = ctrl_fill_mcgrp_info(grp, portid, seq, 0, skb, cmd); |
2dbba6f7 JB |
814 | if (err < 0) { |
815 | nlmsg_free(skb); | |
816 | return ERR_PTR(err); | |
817 | } | |
818 | ||
819 | return skb; | |
820 | } | |
821 | ||
ef7c79ed | 822 | static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = { |
482a8524 | 823 | [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, |
5176f91e TG |
824 | [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, |
825 | .len = GENL_NAMSIZ - 1 }, | |
482a8524 TG |
826 | }; |
827 | ||
828 | static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) | |
829 | { | |
830 | struct sk_buff *msg; | |
831 | struct genl_family *res = NULL; | |
832 | int err = -EINVAL; | |
833 | ||
834 | if (info->attrs[CTRL_ATTR_FAMILY_ID]) { | |
835 | u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]); | |
836 | res = genl_family_find_byid(id); | |
134e6375 | 837 | err = -ENOENT; |
482a8524 TG |
838 | } |
839 | ||
840 | if (info->attrs[CTRL_ATTR_FAMILY_NAME]) { | |
5176f91e | 841 | char *name; |
482a8524 | 842 | |
5176f91e | 843 | name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]); |
482a8524 | 844 | res = genl_family_find_byname(name); |
fa843095 SH |
845 | #ifdef CONFIG_MODULES |
846 | if (res == NULL) { | |
847 | genl_unlock(); | |
c74f2b26 | 848 | up_read(&cb_lock); |
e9412c37 | 849 | request_module("net-pf-%d-proto-%d-family-%s", |
fa843095 | 850 | PF_NETLINK, NETLINK_GENERIC, name); |
c74f2b26 | 851 | down_read(&cb_lock); |
fa843095 SH |
852 | genl_lock(); |
853 | res = genl_family_find_byname(name); | |
854 | } | |
855 | #endif | |
134e6375 | 856 | err = -ENOENT; |
482a8524 TG |
857 | } |
858 | ||
134e6375 JB |
859 | if (res == NULL) |
860 | return err; | |
861 | ||
862 | if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) { | |
863 | /* family doesn't exist here */ | |
864 | return -ENOENT; | |
482a8524 TG |
865 | } |
866 | ||
15e47304 | 867 | msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq, |
2dbba6f7 | 868 | CTRL_CMD_NEWFAMILY); |
134e6375 JB |
869 | if (IS_ERR(msg)) |
870 | return PTR_ERR(msg); | |
482a8524 | 871 | |
134e6375 | 872 | return genlmsg_reply(msg, info); |
482a8524 TG |
873 | } |
874 | ||
875 | static int genl_ctrl_event(int event, void *data) | |
876 | { | |
877 | struct sk_buff *msg; | |
134e6375 JB |
878 | struct genl_family *family; |
879 | struct genl_multicast_group *grp; | |
482a8524 | 880 | |
134e6375 JB |
881 | /* genl is still initialising */ |
882 | if (!init_net.genl_sock) | |
482a8524 TG |
883 | return 0; |
884 | ||
885 | switch (event) { | |
886 | case CTRL_CMD_NEWFAMILY: | |
887 | case CTRL_CMD_DELFAMILY: | |
134e6375 JB |
888 | family = data; |
889 | msg = ctrl_build_family_msg(family, 0, 0, event); | |
2dbba6f7 JB |
890 | break; |
891 | case CTRL_CMD_NEWMCAST_GRP: | |
892 | case CTRL_CMD_DELMCAST_GRP: | |
134e6375 JB |
893 | grp = data; |
894 | family = grp->family; | |
2dbba6f7 | 895 | msg = ctrl_build_mcgrp_msg(data, 0, 0, event); |
482a8524 | 896 | break; |
134e6375 JB |
897 | default: |
898 | return -EINVAL; | |
899 | } | |
900 | ||
901 | if (IS_ERR(msg)) | |
902 | return PTR_ERR(msg); | |
903 | ||
904 | if (!family->netnsok) { | |
905 | genlmsg_multicast_netns(&init_net, msg, 0, | |
906 | GENL_ID_CTRL, GFP_KERNEL); | |
907 | } else { | |
908 | rcu_read_lock(); | |
909 | genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC); | |
910 | rcu_read_unlock(); | |
482a8524 TG |
911 | } |
912 | ||
913 | return 0; | |
914 | } | |
915 | ||
c53ed742 JB |
916 | static struct genl_ops genl_ctrl_ops[] = { |
917 | { | |
918 | .cmd = CTRL_CMD_GETFAMILY, | |
919 | .doit = ctrl_getfamily, | |
920 | .dumpit = ctrl_dumpfamily, | |
921 | .policy = ctrl_policy, | |
922 | }, | |
482a8524 TG |
923 | }; |
924 | ||
2dbba6f7 JB |
925 | static struct genl_multicast_group notify_grp = { |
926 | .name = "notify", | |
927 | }; | |
928 | ||
134e6375 JB |
929 | static int __net_init genl_pernet_init(struct net *net) |
930 | { | |
a31f2d17 PNA |
931 | struct netlink_kernel_cfg cfg = { |
932 | .input = genl_rcv, | |
9785e10a | 933 | .flags = NL_CFG_F_NONROOT_RECV, |
a31f2d17 PNA |
934 | }; |
935 | ||
134e6375 | 936 | /* we'll bump the group number right afterwards */ |
9f00d977 | 937 | net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg); |
134e6375 JB |
938 | |
939 | if (!net->genl_sock && net_eq(net, &init_net)) | |
940 | panic("GENL: Cannot initialize generic netlink\n"); | |
941 | ||
942 | if (!net->genl_sock) | |
943 | return -ENOMEM; | |
944 | ||
945 | return 0; | |
946 | } | |
947 | ||
948 | static void __net_exit genl_pernet_exit(struct net *net) | |
949 | { | |
950 | netlink_kernel_release(net->genl_sock); | |
951 | net->genl_sock = NULL; | |
952 | } | |
953 | ||
954 | static struct pernet_operations genl_pernet_ops = { | |
955 | .init = genl_pernet_init, | |
956 | .exit = genl_pernet_exit, | |
957 | }; | |
958 | ||
482a8524 TG |
959 | static int __init genl_init(void) |
960 | { | |
961 | int i, err; | |
962 | ||
963 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | |
964 | INIT_LIST_HEAD(&family_ht[i]); | |
965 | ||
c53ed742 | 966 | err = genl_register_family_with_ops(&genl_ctrl, genl_ctrl_ops); |
482a8524 | 967 | if (err < 0) |
134e6375 | 968 | goto problem; |
482a8524 | 969 | |
134e6375 JB |
970 | err = register_pernet_subsys(&genl_pernet_ops); |
971 | if (err) | |
972 | goto problem; | |
482a8524 | 973 | |
2dbba6f7 JB |
974 | err = genl_register_mc_group(&genl_ctrl, ¬ify_grp); |
975 | if (err < 0) | |
134e6375 | 976 | goto problem; |
2dbba6f7 | 977 | |
482a8524 TG |
978 | return 0; |
979 | ||
134e6375 | 980 | problem: |
482a8524 | 981 | panic("GENL: Cannot register controller: %d\n", err); |
482a8524 TG |
982 | } |
983 | ||
984 | subsys_initcall(genl_init); | |
985 | ||
15e47304 | 986 | static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group, |
134e6375 JB |
987 | gfp_t flags) |
988 | { | |
989 | struct sk_buff *tmp; | |
990 | struct net *net, *prev = NULL; | |
991 | int err; | |
992 | ||
993 | for_each_net_rcu(net) { | |
994 | if (prev) { | |
995 | tmp = skb_clone(skb, flags); | |
996 | if (!tmp) { | |
997 | err = -ENOMEM; | |
998 | goto error; | |
999 | } | |
1000 | err = nlmsg_multicast(prev->genl_sock, tmp, | |
15e47304 | 1001 | portid, group, flags); |
134e6375 JB |
1002 | if (err) |
1003 | goto error; | |
1004 | } | |
1005 | ||
1006 | prev = net; | |
1007 | } | |
1008 | ||
15e47304 | 1009 | return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags); |
134e6375 JB |
1010 | error: |
1011 | kfree_skb(skb); | |
1012 | return err; | |
1013 | } | |
1014 | ||
15e47304 | 1015 | int genlmsg_multicast_allns(struct sk_buff *skb, u32 portid, unsigned int group, |
134e6375 JB |
1016 | gfp_t flags) |
1017 | { | |
15e47304 | 1018 | return genlmsg_mcast(skb, portid, group, flags); |
134e6375 JB |
1019 | } |
1020 | EXPORT_SYMBOL(genlmsg_multicast_allns); | |
263ba61d | 1021 | |
15e47304 | 1022 | void genl_notify(struct sk_buff *skb, struct net *net, u32 portid, u32 group, |
263ba61d PS |
1023 | struct nlmsghdr *nlh, gfp_t flags) |
1024 | { | |
1025 | struct sock *sk = net->genl_sock; | |
1026 | int report = 0; | |
1027 | ||
1028 | if (nlh) | |
1029 | report = nlmsg_report(nlh); | |
1030 | ||
15e47304 | 1031 | nlmsg_notify(sk, skb, portid, group, report, flags); |
263ba61d PS |
1032 | } |
1033 | EXPORT_SYMBOL(genl_notify); |