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. | |
2ecf7536 JB |
72 | * Bit 17 is marked as already used since the VFS quota code |
73 | * also abused this API and relied on family == group ID, we | |
74 | * cater to that by giving it a static family and group ID. | |
2dbba6f7 | 75 | */ |
2ecf7536 | 76 | static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_VFS_DQUOT); |
2dbba6f7 JB |
77 | static unsigned long *mc_groups = &mc_group_start; |
78 | static unsigned long mc_groups_longs = 1; | |
482a8524 | 79 | |
c2ebb908 JB |
80 | static int genl_ctrl_event(int event, struct genl_family *family, |
81 | struct genl_multicast_group *grp); | |
482a8524 TG |
82 | |
83 | static inline unsigned int genl_family_hash(unsigned int id) | |
84 | { | |
85 | return id & GENL_FAM_TAB_MASK; | |
86 | } | |
87 | ||
88 | static inline struct list_head *genl_family_chain(unsigned int id) | |
89 | { | |
90 | return &family_ht[genl_family_hash(id)]; | |
91 | } | |
92 | ||
93 | static struct genl_family *genl_family_find_byid(unsigned int id) | |
94 | { | |
95 | struct genl_family *f; | |
96 | ||
97 | list_for_each_entry(f, genl_family_chain(id), family_list) | |
98 | if (f->id == id) | |
99 | return f; | |
100 | ||
101 | return NULL; | |
102 | } | |
103 | ||
104 | static struct genl_family *genl_family_find_byname(char *name) | |
105 | { | |
106 | struct genl_family *f; | |
107 | int i; | |
108 | ||
109 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | |
110 | list_for_each_entry(f, genl_family_chain(i), family_list) | |
111 | if (strcmp(f->name, name) == 0) | |
112 | return f; | |
113 | ||
114 | return NULL; | |
115 | } | |
116 | ||
f84f771d | 117 | static const struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family) |
482a8524 | 118 | { |
d91824c0 | 119 | int i; |
482a8524 | 120 | |
d91824c0 JB |
121 | for (i = 0; i < family->n_ops; i++) |
122 | if (family->ops[i].cmd == cmd) | |
123 | return &family->ops[i]; | |
482a8524 TG |
124 | |
125 | return NULL; | |
126 | } | |
127 | ||
128 | /* Of course we are going to have problems once we hit | |
129 | * 2^16 alive types, but that can only happen by year 2K | |
130 | */ | |
b57ef81f | 131 | static u16 genl_generate_id(void) |
482a8524 | 132 | { |
988ade6b KK |
133 | static u16 id_gen_idx = GENL_MIN_ID; |
134 | int i; | |
482a8524 | 135 | |
988ade6b | 136 | for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) { |
2ecf7536 JB |
137 | if (id_gen_idx != GENL_ID_VFS_DQUOT && |
138 | !genl_family_find_byid(id_gen_idx)) | |
988ade6b KK |
139 | return id_gen_idx; |
140 | if (++id_gen_idx > GENL_MAX_ID) | |
482a8524 | 141 | id_gen_idx = GENL_MIN_ID; |
988ade6b | 142 | } |
482a8524 | 143 | |
988ade6b | 144 | return 0; |
482a8524 TG |
145 | } |
146 | ||
2dbba6f7 JB |
147 | static struct genl_multicast_group notify_grp; |
148 | ||
149 | /** | |
150 | * genl_register_mc_group - register a multicast group | |
151 | * | |
152 | * Registers the specified multicast group and notifies userspace | |
153 | * about the new group. | |
154 | * | |
155 | * Returns 0 on success or a negative error code. | |
156 | * | |
157 | * @family: The generic netlink family the group shall be registered for. | |
158 | * @grp: The group to register, must have a name. | |
159 | */ | |
160 | int genl_register_mc_group(struct genl_family *family, | |
161 | struct genl_multicast_group *grp) | |
162 | { | |
163 | int id; | |
164 | unsigned long *new_groups; | |
b1f57195 | 165 | int err = 0; |
2dbba6f7 JB |
166 | |
167 | BUG_ON(grp->name[0] == '\0'); | |
f1e79e20 | 168 | BUG_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL); |
2dbba6f7 | 169 | |
def31174 | 170 | genl_lock_all(); |
2dbba6f7 | 171 | |
e5dcecba | 172 | /* special-case our own group and hacks */ |
2dbba6f7 JB |
173 | if (grp == ¬ify_grp) |
174 | id = GENL_ID_CTRL; | |
e5dcecba JB |
175 | else if (strcmp(family->name, "NET_DM") == 0) |
176 | id = 1; | |
2ecf7536 JB |
177 | else if (strcmp(family->name, "VFS_DQUOT") == 0) |
178 | id = GENL_ID_VFS_DQUOT; | |
2dbba6f7 JB |
179 | else |
180 | id = find_first_zero_bit(mc_groups, | |
181 | mc_groups_longs * BITS_PER_LONG); | |
182 | ||
183 | ||
184 | if (id >= mc_groups_longs * BITS_PER_LONG) { | |
185 | size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long); | |
186 | ||
187 | if (mc_groups == &mc_group_start) { | |
188 | new_groups = kzalloc(nlen, GFP_KERNEL); | |
189 | if (!new_groups) { | |
190 | err = -ENOMEM; | |
191 | goto out; | |
192 | } | |
193 | mc_groups = new_groups; | |
194 | *mc_groups = mc_group_start; | |
195 | } else { | |
196 | new_groups = krealloc(mc_groups, nlen, GFP_KERNEL); | |
197 | if (!new_groups) { | |
198 | err = -ENOMEM; | |
199 | goto out; | |
200 | } | |
201 | mc_groups = new_groups; | |
202 | mc_groups[mc_groups_longs] = 0; | |
203 | } | |
204 | mc_groups_longs++; | |
205 | } | |
206 | ||
134e6375 JB |
207 | if (family->netnsok) { |
208 | struct net *net; | |
209 | ||
d136f1bd | 210 | netlink_table_grab(); |
134e6375 JB |
211 | rcu_read_lock(); |
212 | for_each_net_rcu(net) { | |
d136f1bd | 213 | err = __netlink_change_ngroups(net->genl_sock, |
134e6375 JB |
214 | mc_groups_longs * BITS_PER_LONG); |
215 | if (err) { | |
216 | /* | |
217 | * No need to roll back, can only fail if | |
218 | * memory allocation fails and then the | |
219 | * number of _possible_ groups has been | |
220 | * increased on some sockets which is ok. | |
221 | */ | |
222 | rcu_read_unlock(); | |
d136f1bd | 223 | netlink_table_ungrab(); |
134e6375 JB |
224 | goto out; |
225 | } | |
226 | } | |
227 | rcu_read_unlock(); | |
d136f1bd | 228 | netlink_table_ungrab(); |
134e6375 JB |
229 | } else { |
230 | err = netlink_change_ngroups(init_net.genl_sock, | |
231 | mc_groups_longs * BITS_PER_LONG); | |
232 | if (err) | |
233 | goto out; | |
234 | } | |
2dbba6f7 JB |
235 | |
236 | grp->id = id; | |
237 | set_bit(id, mc_groups); | |
238 | list_add_tail(&grp->list, &family->mcast_groups); | |
2dbba6f7 | 239 | |
c2ebb908 | 240 | genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family, grp); |
2dbba6f7 | 241 | out: |
def31174 | 242 | genl_unlock_all(); |
79d310d0 | 243 | return err; |
2dbba6f7 JB |
244 | } |
245 | EXPORT_SYMBOL(genl_register_mc_group); | |
246 | ||
79dc4386 TG |
247 | static void __genl_unregister_mc_group(struct genl_family *family, |
248 | struct genl_multicast_group *grp) | |
249 | { | |
134e6375 | 250 | struct net *net; |
134e6375 | 251 | |
b8273570 | 252 | netlink_table_grab(); |
134e6375 JB |
253 | rcu_read_lock(); |
254 | for_each_net_rcu(net) | |
b8273570 | 255 | __netlink_clear_multicast_users(net->genl_sock, grp->id); |
134e6375 | 256 | rcu_read_unlock(); |
b8273570 | 257 | netlink_table_ungrab(); |
134e6375 | 258 | |
e5dcecba JB |
259 | if (grp->id != 1) |
260 | clear_bit(grp->id, mc_groups); | |
79dc4386 | 261 | list_del(&grp->list); |
c2ebb908 | 262 | genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family, grp); |
79dc4386 | 263 | grp->id = 0; |
79dc4386 TG |
264 | } |
265 | ||
2dbba6f7 JB |
266 | static void genl_unregister_mc_groups(struct genl_family *family) |
267 | { | |
268 | struct genl_multicast_group *grp, *tmp; | |
269 | ||
270 | list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list) | |
79dc4386 | 271 | __genl_unregister_mc_group(family, grp); |
2dbba6f7 JB |
272 | } |
273 | ||
568508aa | 274 | static int genl_validate_ops(struct genl_family *family) |
482a8524 | 275 | { |
568508aa JB |
276 | const struct genl_ops *ops = family->ops; |
277 | unsigned int n_ops = family->n_ops; | |
d91824c0 JB |
278 | int i, j; |
279 | ||
568508aa JB |
280 | if (WARN_ON(n_ops && !ops)) |
281 | return -EINVAL; | |
282 | ||
283 | if (!n_ops) | |
284 | return 0; | |
285 | ||
d91824c0 JB |
286 | for (i = 0; i < n_ops; i++) { |
287 | if (ops[i].dumpit == NULL && ops[i].doit == NULL) | |
288 | return -EINVAL; | |
289 | for (j = i + 1; j < n_ops; j++) | |
290 | if (ops[i].cmd == ops[j].cmd) | |
291 | return -EINVAL; | |
482a8524 TG |
292 | } |
293 | ||
d91824c0 JB |
294 | /* family is not registered yet, so no locking needed */ |
295 | family->ops = ops; | |
296 | family->n_ops = n_ops; | |
482a8524 | 297 | |
d91824c0 | 298 | return 0; |
482a8524 | 299 | } |
482a8524 TG |
300 | |
301 | /** | |
33c6b1f6 | 302 | * __genl_register_family - register a generic netlink family |
482a8524 TG |
303 | * @family: generic netlink family |
304 | * | |
305 | * Registers the specified family after validating it first. Only one | |
306 | * family may be registered with the same family name or identifier. | |
307 | * The family id may equal GENL_ID_GENERATE causing an unique id to | |
308 | * be automatically generated and assigned. | |
309 | * | |
568508aa JB |
310 | * The family's ops array must already be assigned, you can use the |
311 | * genl_register_family_with_ops() helper function. | |
312 | * | |
482a8524 TG |
313 | * Return 0 on success or a negative error code. |
314 | */ | |
33c6b1f6 | 315 | int __genl_register_family(struct genl_family *family) |
482a8524 TG |
316 | { |
317 | int err = -EINVAL; | |
318 | ||
319 | if (family->id && family->id < GENL_MIN_ID) | |
320 | goto errout; | |
321 | ||
322 | if (family->id > GENL_MAX_ID) | |
323 | goto errout; | |
324 | ||
568508aa JB |
325 | err = genl_validate_ops(family); |
326 | if (err) | |
327 | return err; | |
328 | ||
2dbba6f7 | 329 | INIT_LIST_HEAD(&family->mcast_groups); |
482a8524 | 330 | |
def31174 | 331 | genl_lock_all(); |
482a8524 TG |
332 | |
333 | if (genl_family_find_byname(family->name)) { | |
334 | err = -EEXIST; | |
335 | goto errout_locked; | |
336 | } | |
337 | ||
482a8524 TG |
338 | if (family->id == GENL_ID_GENERATE) { |
339 | u16 newid = genl_generate_id(); | |
340 | ||
341 | if (!newid) { | |
342 | err = -ENOMEM; | |
343 | goto errout_locked; | |
344 | } | |
345 | ||
346 | family->id = newid; | |
93860b08 KK |
347 | } else if (genl_family_find_byid(family->id)) { |
348 | err = -EEXIST; | |
349 | goto errout_locked; | |
482a8524 TG |
350 | } |
351 | ||
def31174 | 352 | if (family->maxattr && !family->parallel_ops) { |
482a8524 TG |
353 | family->attrbuf = kmalloc((family->maxattr+1) * |
354 | sizeof(struct nlattr *), GFP_KERNEL); | |
355 | if (family->attrbuf == NULL) { | |
356 | err = -ENOMEM; | |
e200bd80 | 357 | goto errout_locked; |
482a8524 TG |
358 | } |
359 | } else | |
360 | family->attrbuf = NULL; | |
361 | ||
362 | list_add_tail(&family->family_list, genl_family_chain(family->id)); | |
def31174 | 363 | genl_unlock_all(); |
482a8524 | 364 | |
c2ebb908 | 365 | genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL); |
482a8524 TG |
366 | |
367 | return 0; | |
368 | ||
369 | errout_locked: | |
def31174 | 370 | genl_unlock_all(); |
482a8524 TG |
371 | errout: |
372 | return err; | |
373 | } | |
33c6b1f6 | 374 | EXPORT_SYMBOL(__genl_register_family); |
482a8524 TG |
375 | |
376 | /** | |
377 | * genl_unregister_family - unregister generic netlink family | |
378 | * @family: generic netlink family | |
379 | * | |
380 | * Unregisters the specified family. | |
381 | * | |
382 | * Returns 0 on success or a negative error code. | |
383 | */ | |
384 | int genl_unregister_family(struct genl_family *family) | |
385 | { | |
386 | struct genl_family *rc; | |
387 | ||
def31174 | 388 | genl_lock_all(); |
482a8524 | 389 | |
910d6c32 PE |
390 | genl_unregister_mc_groups(family); |
391 | ||
482a8524 TG |
392 | list_for_each_entry(rc, genl_family_chain(family->id), family_list) { |
393 | if (family->id != rc->id || strcmp(rc->name, family->name)) | |
394 | continue; | |
395 | ||
396 | list_del(&rc->family_list); | |
d91824c0 | 397 | family->n_ops = 0; |
def31174 | 398 | genl_unlock_all(); |
482a8524 | 399 | |
482a8524 | 400 | kfree(family->attrbuf); |
c2ebb908 | 401 | genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL); |
482a8524 TG |
402 | return 0; |
403 | } | |
404 | ||
def31174 | 405 | genl_unlock_all(); |
482a8524 TG |
406 | |
407 | return -ENOENT; | |
408 | } | |
416c2f9c | 409 | EXPORT_SYMBOL(genl_unregister_family); |
482a8524 | 410 | |
a46621a3 DV |
411 | /** |
412 | * genlmsg_put - Add generic netlink header to netlink message | |
413 | * @skb: socket buffer holding the message | |
15e47304 | 414 | * @portid: netlink portid the message is addressed to |
a46621a3 DV |
415 | * @seq: sequence number (usually the one of the sender) |
416 | * @family: generic netlink family | |
2c53040f | 417 | * @flags: netlink message flags |
a46621a3 DV |
418 | * @cmd: generic netlink command |
419 | * | |
420 | * Returns pointer to user specific header | |
421 | */ | |
15e47304 | 422 | void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, |
a46621a3 DV |
423 | struct genl_family *family, int flags, u8 cmd) |
424 | { | |
425 | struct nlmsghdr *nlh; | |
426 | struct genlmsghdr *hdr; | |
427 | ||
15e47304 | 428 | nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN + |
a46621a3 DV |
429 | family->hdrsize, flags); |
430 | if (nlh == NULL) | |
431 | return NULL; | |
432 | ||
433 | hdr = nlmsg_data(nlh); | |
434 | hdr->cmd = cmd; | |
435 | hdr->version = family->version; | |
436 | hdr->reserved = 0; | |
437 | ||
438 | return (char *) hdr + GENL_HDRLEN; | |
439 | } | |
440 | EXPORT_SYMBOL(genlmsg_put); | |
441 | ||
9b96309c PS |
442 | static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) |
443 | { | |
f84f771d JB |
444 | /* our ops are always const - netlink API doesn't propagate that */ |
445 | const struct genl_ops *ops = cb->data; | |
9b96309c PS |
446 | int rc; |
447 | ||
448 | genl_lock(); | |
449 | rc = ops->dumpit(skb, cb); | |
450 | genl_unlock(); | |
451 | return rc; | |
452 | } | |
453 | ||
454 | static int genl_lock_done(struct netlink_callback *cb) | |
455 | { | |
f84f771d JB |
456 | /* our ops are always const - netlink API doesn't propagate that */ |
457 | const struct genl_ops *ops = cb->data; | |
9b96309c PS |
458 | int rc = 0; |
459 | ||
460 | if (ops->done) { | |
461 | genl_lock(); | |
462 | rc = ops->done(cb); | |
463 | genl_unlock(); | |
464 | } | |
465 | return rc; | |
466 | } | |
467 | ||
def31174 PS |
468 | static int genl_family_rcv_msg(struct genl_family *family, |
469 | struct sk_buff *skb, | |
470 | struct nlmsghdr *nlh) | |
482a8524 | 471 | { |
f84f771d | 472 | const struct genl_ops *ops; |
134e6375 | 473 | struct net *net = sock_net(skb->sk); |
482a8524 TG |
474 | struct genl_info info; |
475 | struct genlmsghdr *hdr = nlmsg_data(nlh); | |
def31174 | 476 | struct nlattr **attrbuf; |
1d00a4eb | 477 | int hdrlen, err; |
482a8524 | 478 | |
134e6375 JB |
479 | /* this family doesn't exist in this netns */ |
480 | if (!family->netnsok && !net_eq(net, &init_net)) | |
481 | return -ENOENT; | |
482 | ||
482a8524 TG |
483 | hdrlen = GENL_HDRLEN + family->hdrsize; |
484 | if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen)) | |
1d00a4eb | 485 | return -EINVAL; |
482a8524 TG |
486 | |
487 | ops = genl_get_cmd(hdr->cmd, family); | |
1d00a4eb TG |
488 | if (ops == NULL) |
489 | return -EOPNOTSUPP; | |
482a8524 | 490 | |
1d00a4eb | 491 | if ((ops->flags & GENL_ADMIN_PERM) && |
fd778461 | 492 | !capable(CAP_NET_ADMIN)) |
1d00a4eb | 493 | return -EPERM; |
482a8524 | 494 | |
e1ee3673 | 495 | if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) { |
9b96309c | 496 | int rc; |
def31174 | 497 | |
1d00a4eb TG |
498 | if (ops->dumpit == NULL) |
499 | return -EOPNOTSUPP; | |
482a8524 | 500 | |
9b96309c PS |
501 | if (!family->parallel_ops) { |
502 | struct netlink_dump_control c = { | |
33c6b1f6 | 503 | .module = family->module, |
f84f771d JB |
504 | /* we have const, but the netlink API doesn't */ |
505 | .data = (void *)ops, | |
9b96309c PS |
506 | .dump = genl_lock_dumpit, |
507 | .done = genl_lock_done, | |
508 | }; | |
509 | ||
510 | genl_unlock(); | |
33c6b1f6 | 511 | rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c); |
9b96309c PS |
512 | genl_lock(); |
513 | ||
514 | } else { | |
515 | struct netlink_dump_control c = { | |
33c6b1f6 | 516 | .module = family->module, |
9b96309c PS |
517 | .dump = ops->dumpit, |
518 | .done = ops->done, | |
519 | }; | |
520 | ||
33c6b1f6 | 521 | rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c); |
9b96309c PS |
522 | } |
523 | ||
524 | return rc; | |
482a8524 TG |
525 | } |
526 | ||
1d00a4eb TG |
527 | if (ops->doit == NULL) |
528 | return -EOPNOTSUPP; | |
482a8524 | 529 | |
def31174 PS |
530 | if (family->maxattr && family->parallel_ops) { |
531 | attrbuf = kmalloc((family->maxattr+1) * | |
532 | sizeof(struct nlattr *), GFP_KERNEL); | |
533 | if (attrbuf == NULL) | |
534 | return -ENOMEM; | |
535 | } else | |
536 | attrbuf = family->attrbuf; | |
537 | ||
538 | if (attrbuf) { | |
539 | err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr, | |
482a8524 TG |
540 | ops->policy); |
541 | if (err < 0) | |
50754d21 | 542 | goto out; |
482a8524 TG |
543 | } |
544 | ||
545 | info.snd_seq = nlh->nlmsg_seq; | |
15e47304 | 546 | info.snd_portid = NETLINK_CB(skb).portid; |
482a8524 TG |
547 | info.nlhdr = nlh; |
548 | info.genlhdr = nlmsg_data(nlh); | |
549 | info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN; | |
def31174 | 550 | info.attrs = attrbuf; |
134e6375 | 551 | genl_info_net_set(&info, net); |
ff4c92d8 | 552 | memset(&info.user_ptr, 0, sizeof(info.user_ptr)); |
482a8524 | 553 | |
ff4c92d8 JB |
554 | if (family->pre_doit) { |
555 | err = family->pre_doit(ops, skb, &info); | |
556 | if (err) | |
50754d21 | 557 | goto out; |
ff4c92d8 JB |
558 | } |
559 | ||
560 | err = ops->doit(skb, &info); | |
561 | ||
562 | if (family->post_doit) | |
563 | family->post_doit(ops, skb, &info); | |
564 | ||
50754d21 | 565 | out: |
def31174 PS |
566 | if (family->parallel_ops) |
567 | kfree(attrbuf); | |
568 | ||
569 | return err; | |
570 | } | |
571 | ||
572 | static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) | |
573 | { | |
574 | struct genl_family *family; | |
575 | int err; | |
576 | ||
577 | family = genl_family_find_byid(nlh->nlmsg_type); | |
578 | if (family == NULL) | |
579 | return -ENOENT; | |
580 | ||
581 | if (!family->parallel_ops) | |
582 | genl_lock(); | |
583 | ||
584 | err = genl_family_rcv_msg(family, skb, nlh); | |
585 | ||
586 | if (!family->parallel_ops) | |
587 | genl_unlock(); | |
588 | ||
ff4c92d8 | 589 | return err; |
482a8524 TG |
590 | } |
591 | ||
cd40b7d3 | 592 | static void genl_rcv(struct sk_buff *skb) |
482a8524 | 593 | { |
def31174 | 594 | down_read(&cb_lock); |
cd40b7d3 | 595 | netlink_rcv_skb(skb, &genl_rcv_msg); |
def31174 | 596 | up_read(&cb_lock); |
482a8524 TG |
597 | } |
598 | ||
599 | /************************************************************************** | |
600 | * Controller | |
601 | **************************************************************************/ | |
602 | ||
17c157c8 TG |
603 | static struct genl_family genl_ctrl = { |
604 | .id = GENL_ID_CTRL, | |
605 | .name = "nlctrl", | |
334c29a6 | 606 | .version = 0x2, |
17c157c8 | 607 | .maxattr = CTRL_ATTR_MAX, |
134e6375 | 608 | .netnsok = true, |
17c157c8 TG |
609 | }; |
610 | ||
15e47304 | 611 | static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq, |
482a8524 TG |
612 | u32 flags, struct sk_buff *skb, u8 cmd) |
613 | { | |
614 | void *hdr; | |
615 | ||
15e47304 | 616 | hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd); |
482a8524 TG |
617 | if (hdr == NULL) |
618 | return -1; | |
619 | ||
444653f6 DM |
620 | if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) || |
621 | nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) || | |
622 | nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) || | |
623 | nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) || | |
624 | nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr)) | |
625 | goto nla_put_failure; | |
eb328111 | 626 | |
d91824c0 | 627 | if (family->n_ops) { |
e94ef682 | 628 | struct nlattr *nla_ops; |
d91824c0 | 629 | int i; |
eb328111 | 630 | |
e94ef682 TG |
631 | nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS); |
632 | if (nla_ops == NULL) | |
eb328111 TG |
633 | goto nla_put_failure; |
634 | ||
d91824c0 | 635 | for (i = 0; i < family->n_ops; i++) { |
e94ef682 | 636 | struct nlattr *nest; |
f84f771d | 637 | const struct genl_ops *ops = &family->ops[i]; |
029b234f | 638 | u32 op_flags = ops->flags; |
f84f771d JB |
639 | |
640 | if (ops->dumpit) | |
029b234f | 641 | op_flags |= GENL_CMD_CAP_DUMP; |
f84f771d | 642 | if (ops->doit) |
029b234f | 643 | op_flags |= GENL_CMD_CAP_DO; |
f84f771d | 644 | if (ops->policy) |
029b234f | 645 | op_flags |= GENL_CMD_CAP_HASPOL; |
eb328111 | 646 | |
d91824c0 | 647 | nest = nla_nest_start(skb, i + 1); |
e94ef682 TG |
648 | if (nest == NULL) |
649 | goto nla_put_failure; | |
eb328111 | 650 | |
444653f6 | 651 | if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) || |
029b234f | 652 | nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags)) |
444653f6 | 653 | goto nla_put_failure; |
eb328111 | 654 | |
e94ef682 TG |
655 | nla_nest_end(skb, nest); |
656 | } | |
657 | ||
658 | nla_nest_end(skb, nla_ops); | |
659 | } | |
482a8524 | 660 | |
2dbba6f7 JB |
661 | if (!list_empty(&family->mcast_groups)) { |
662 | struct genl_multicast_group *grp; | |
663 | struct nlattr *nla_grps; | |
664 | int idx = 1; | |
665 | ||
666 | nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); | |
667 | if (nla_grps == NULL) | |
668 | goto nla_put_failure; | |
669 | ||
670 | list_for_each_entry(grp, &family->mcast_groups, list) { | |
671 | struct nlattr *nest; | |
672 | ||
673 | nest = nla_nest_start(skb, idx++); | |
674 | if (nest == NULL) | |
675 | goto nla_put_failure; | |
676 | ||
444653f6 DM |
677 | if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) || |
678 | nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME, | |
679 | grp->name)) | |
680 | goto nla_put_failure; | |
2dbba6f7 JB |
681 | |
682 | nla_nest_end(skb, nest); | |
683 | } | |
684 | nla_nest_end(skb, nla_grps); | |
685 | } | |
686 | ||
687 | return genlmsg_end(skb, hdr); | |
688 | ||
689 | nla_put_failure: | |
bc3ed28c TG |
690 | genlmsg_cancel(skb, hdr); |
691 | return -EMSGSIZE; | |
2dbba6f7 JB |
692 | } |
693 | ||
c2ebb908 JB |
694 | static int ctrl_fill_mcgrp_info(struct genl_family *family, |
695 | struct genl_multicast_group *grp, u32 portid, | |
2dbba6f7 JB |
696 | u32 seq, u32 flags, struct sk_buff *skb, |
697 | u8 cmd) | |
698 | { | |
699 | void *hdr; | |
700 | struct nlattr *nla_grps; | |
701 | struct nlattr *nest; | |
702 | ||
15e47304 | 703 | hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd); |
2dbba6f7 JB |
704 | if (hdr == NULL) |
705 | return -1; | |
706 | ||
c2ebb908 JB |
707 | if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) || |
708 | nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id)) | |
444653f6 | 709 | goto nla_put_failure; |
2dbba6f7 JB |
710 | |
711 | nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS); | |
712 | if (nla_grps == NULL) | |
713 | goto nla_put_failure; | |
714 | ||
715 | nest = nla_nest_start(skb, 1); | |
716 | if (nest == NULL) | |
717 | goto nla_put_failure; | |
718 | ||
444653f6 DM |
719 | if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id) || |
720 | nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME, | |
721 | grp->name)) | |
722 | goto nla_put_failure; | |
2dbba6f7 JB |
723 | |
724 | nla_nest_end(skb, nest); | |
725 | nla_nest_end(skb, nla_grps); | |
726 | ||
482a8524 TG |
727 | return genlmsg_end(skb, hdr); |
728 | ||
729 | nla_put_failure: | |
bc3ed28c TG |
730 | genlmsg_cancel(skb, hdr); |
731 | return -EMSGSIZE; | |
482a8524 TG |
732 | } |
733 | ||
734 | static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) | |
735 | { | |
736 | ||
737 | int i, n = 0; | |
738 | struct genl_family *rt; | |
134e6375 | 739 | struct net *net = sock_net(skb->sk); |
482a8524 TG |
740 | int chains_to_skip = cb->args[0]; |
741 | int fams_to_skip = cb->args[1]; | |
742 | ||
e1d5a010 | 743 | for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) { |
482a8524 TG |
744 | n = 0; |
745 | list_for_each_entry(rt, genl_family_chain(i), family_list) { | |
134e6375 JB |
746 | if (!rt->netnsok && !net_eq(net, &init_net)) |
747 | continue; | |
482a8524 TG |
748 | if (++n < fams_to_skip) |
749 | continue; | |
15e47304 | 750 | if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid, |
482a8524 TG |
751 | cb->nlh->nlmsg_seq, NLM_F_MULTI, |
752 | skb, CTRL_CMD_NEWFAMILY) < 0) | |
753 | goto errout; | |
754 | } | |
755 | ||
756 | fams_to_skip = 0; | |
757 | } | |
758 | ||
759 | errout: | |
760 | cb->args[0] = i; | |
761 | cb->args[1] = n; | |
762 | ||
763 | return skb->len; | |
764 | } | |
765 | ||
2dbba6f7 | 766 | static struct sk_buff *ctrl_build_family_msg(struct genl_family *family, |
15e47304 | 767 | u32 portid, int seq, u8 cmd) |
482a8524 TG |
768 | { |
769 | struct sk_buff *skb; | |
770 | int err; | |
771 | ||
339bf98f | 772 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
482a8524 TG |
773 | if (skb == NULL) |
774 | return ERR_PTR(-ENOBUFS); | |
775 | ||
15e47304 | 776 | err = ctrl_fill_info(family, portid, seq, 0, skb, cmd); |
482a8524 TG |
777 | if (err < 0) { |
778 | nlmsg_free(skb); | |
779 | return ERR_PTR(err); | |
780 | } | |
781 | ||
782 | return skb; | |
783 | } | |
784 | ||
c2ebb908 JB |
785 | static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_family *family, |
786 | struct genl_multicast_group *grp, | |
15e47304 | 787 | u32 portid, int seq, u8 cmd) |
2dbba6f7 JB |
788 | { |
789 | struct sk_buff *skb; | |
790 | int err; | |
791 | ||
792 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
793 | if (skb == NULL) | |
794 | return ERR_PTR(-ENOBUFS); | |
795 | ||
c2ebb908 | 796 | err = ctrl_fill_mcgrp_info(family, grp, portid, seq, 0, skb, cmd); |
2dbba6f7 JB |
797 | if (err < 0) { |
798 | nlmsg_free(skb); | |
799 | return ERR_PTR(err); | |
800 | } | |
801 | ||
802 | return skb; | |
803 | } | |
804 | ||
ef7c79ed | 805 | static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = { |
482a8524 | 806 | [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 }, |
5176f91e TG |
807 | [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING, |
808 | .len = GENL_NAMSIZ - 1 }, | |
482a8524 TG |
809 | }; |
810 | ||
811 | static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info) | |
812 | { | |
813 | struct sk_buff *msg; | |
814 | struct genl_family *res = NULL; | |
815 | int err = -EINVAL; | |
816 | ||
817 | if (info->attrs[CTRL_ATTR_FAMILY_ID]) { | |
818 | u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]); | |
819 | res = genl_family_find_byid(id); | |
134e6375 | 820 | err = -ENOENT; |
482a8524 TG |
821 | } |
822 | ||
823 | if (info->attrs[CTRL_ATTR_FAMILY_NAME]) { | |
5176f91e | 824 | char *name; |
482a8524 | 825 | |
5176f91e | 826 | name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]); |
482a8524 | 827 | res = genl_family_find_byname(name); |
fa843095 SH |
828 | #ifdef CONFIG_MODULES |
829 | if (res == NULL) { | |
830 | genl_unlock(); | |
c74f2b26 | 831 | up_read(&cb_lock); |
e9412c37 | 832 | request_module("net-pf-%d-proto-%d-family-%s", |
fa843095 | 833 | PF_NETLINK, NETLINK_GENERIC, name); |
c74f2b26 | 834 | down_read(&cb_lock); |
fa843095 SH |
835 | genl_lock(); |
836 | res = genl_family_find_byname(name); | |
837 | } | |
838 | #endif | |
134e6375 | 839 | err = -ENOENT; |
482a8524 TG |
840 | } |
841 | ||
134e6375 JB |
842 | if (res == NULL) |
843 | return err; | |
844 | ||
845 | if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) { | |
846 | /* family doesn't exist here */ | |
847 | return -ENOENT; | |
482a8524 TG |
848 | } |
849 | ||
15e47304 | 850 | msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq, |
2dbba6f7 | 851 | CTRL_CMD_NEWFAMILY); |
134e6375 JB |
852 | if (IS_ERR(msg)) |
853 | return PTR_ERR(msg); | |
482a8524 | 854 | |
134e6375 | 855 | return genlmsg_reply(msg, info); |
482a8524 TG |
856 | } |
857 | ||
c2ebb908 JB |
858 | static int genl_ctrl_event(int event, struct genl_family *family, |
859 | struct genl_multicast_group *grp) | |
482a8524 TG |
860 | { |
861 | struct sk_buff *msg; | |
862 | ||
134e6375 JB |
863 | /* genl is still initialising */ |
864 | if (!init_net.genl_sock) | |
482a8524 TG |
865 | return 0; |
866 | ||
867 | switch (event) { | |
868 | case CTRL_CMD_NEWFAMILY: | |
869 | case CTRL_CMD_DELFAMILY: | |
c2ebb908 | 870 | WARN_ON(grp); |
134e6375 | 871 | msg = ctrl_build_family_msg(family, 0, 0, event); |
2dbba6f7 JB |
872 | break; |
873 | case CTRL_CMD_NEWMCAST_GRP: | |
874 | case CTRL_CMD_DELMCAST_GRP: | |
c2ebb908 JB |
875 | BUG_ON(!grp); |
876 | msg = ctrl_build_mcgrp_msg(family, grp, 0, 0, event); | |
482a8524 | 877 | break; |
134e6375 JB |
878 | default: |
879 | return -EINVAL; | |
880 | } | |
881 | ||
882 | if (IS_ERR(msg)) | |
883 | return PTR_ERR(msg); | |
884 | ||
885 | if (!family->netnsok) { | |
886 | genlmsg_multicast_netns(&init_net, msg, 0, | |
887 | GENL_ID_CTRL, GFP_KERNEL); | |
888 | } else { | |
889 | rcu_read_lock(); | |
890 | genlmsg_multicast_allns(msg, 0, GENL_ID_CTRL, GFP_ATOMIC); | |
891 | rcu_read_unlock(); | |
482a8524 TG |
892 | } |
893 | ||
894 | return 0; | |
895 | } | |
896 | ||
c53ed742 JB |
897 | static struct genl_ops genl_ctrl_ops[] = { |
898 | { | |
899 | .cmd = CTRL_CMD_GETFAMILY, | |
900 | .doit = ctrl_getfamily, | |
901 | .dumpit = ctrl_dumpfamily, | |
902 | .policy = ctrl_policy, | |
903 | }, | |
482a8524 TG |
904 | }; |
905 | ||
2dbba6f7 JB |
906 | static struct genl_multicast_group notify_grp = { |
907 | .name = "notify", | |
908 | }; | |
909 | ||
134e6375 JB |
910 | static int __net_init genl_pernet_init(struct net *net) |
911 | { | |
a31f2d17 PNA |
912 | struct netlink_kernel_cfg cfg = { |
913 | .input = genl_rcv, | |
9785e10a | 914 | .flags = NL_CFG_F_NONROOT_RECV, |
a31f2d17 PNA |
915 | }; |
916 | ||
134e6375 | 917 | /* we'll bump the group number right afterwards */ |
9f00d977 | 918 | net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg); |
134e6375 JB |
919 | |
920 | if (!net->genl_sock && net_eq(net, &init_net)) | |
921 | panic("GENL: Cannot initialize generic netlink\n"); | |
922 | ||
923 | if (!net->genl_sock) | |
924 | return -ENOMEM; | |
925 | ||
926 | return 0; | |
927 | } | |
928 | ||
929 | static void __net_exit genl_pernet_exit(struct net *net) | |
930 | { | |
931 | netlink_kernel_release(net->genl_sock); | |
932 | net->genl_sock = NULL; | |
933 | } | |
934 | ||
935 | static struct pernet_operations genl_pernet_ops = { | |
936 | .init = genl_pernet_init, | |
937 | .exit = genl_pernet_exit, | |
938 | }; | |
939 | ||
482a8524 TG |
940 | static int __init genl_init(void) |
941 | { | |
942 | int i, err; | |
943 | ||
944 | for (i = 0; i < GENL_FAM_TAB_SIZE; i++) | |
945 | INIT_LIST_HEAD(&family_ht[i]); | |
946 | ||
c53ed742 | 947 | err = genl_register_family_with_ops(&genl_ctrl, genl_ctrl_ops); |
482a8524 | 948 | if (err < 0) |
134e6375 | 949 | goto problem; |
482a8524 | 950 | |
134e6375 JB |
951 | err = register_pernet_subsys(&genl_pernet_ops); |
952 | if (err) | |
953 | goto problem; | |
482a8524 | 954 | |
2dbba6f7 JB |
955 | err = genl_register_mc_group(&genl_ctrl, ¬ify_grp); |
956 | if (err < 0) | |
134e6375 | 957 | goto problem; |
2dbba6f7 | 958 | |
482a8524 TG |
959 | return 0; |
960 | ||
134e6375 | 961 | problem: |
482a8524 | 962 | panic("GENL: Cannot register controller: %d\n", err); |
482a8524 TG |
963 | } |
964 | ||
965 | subsys_initcall(genl_init); | |
966 | ||
15e47304 | 967 | static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group, |
134e6375 JB |
968 | gfp_t flags) |
969 | { | |
970 | struct sk_buff *tmp; | |
971 | struct net *net, *prev = NULL; | |
972 | int err; | |
973 | ||
974 | for_each_net_rcu(net) { | |
975 | if (prev) { | |
976 | tmp = skb_clone(skb, flags); | |
977 | if (!tmp) { | |
978 | err = -ENOMEM; | |
979 | goto error; | |
980 | } | |
981 | err = nlmsg_multicast(prev->genl_sock, tmp, | |
15e47304 | 982 | portid, group, flags); |
134e6375 JB |
983 | if (err) |
984 | goto error; | |
985 | } | |
986 | ||
987 | prev = net; | |
988 | } | |
989 | ||
15e47304 | 990 | return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags); |
134e6375 JB |
991 | error: |
992 | kfree_skb(skb); | |
993 | return err; | |
994 | } | |
995 | ||
15e47304 | 996 | int genlmsg_multicast_allns(struct sk_buff *skb, u32 portid, unsigned int group, |
134e6375 JB |
997 | gfp_t flags) |
998 | { | |
15e47304 | 999 | return genlmsg_mcast(skb, portid, group, flags); |
134e6375 JB |
1000 | } |
1001 | EXPORT_SYMBOL(genlmsg_multicast_allns); | |
263ba61d | 1002 | |
15e47304 | 1003 | void genl_notify(struct sk_buff *skb, struct net *net, u32 portid, u32 group, |
263ba61d PS |
1004 | struct nlmsghdr *nlh, gfp_t flags) |
1005 | { | |
1006 | struct sock *sk = net->genl_sock; | |
1007 | int report = 0; | |
1008 | ||
1009 | if (nlh) | |
1010 | report = nlmsg_report(nlh); | |
1011 | ||
15e47304 | 1012 | nlmsg_notify(sk, skb, portid, group, report, flags); |
263ba61d PS |
1013 | } |
1014 | EXPORT_SYMBOL(genl_notify); |