blob: a09132a69869245a20aacc87953213f16a5111e8 [file] [log] [blame]
Thomas Graf482a8522005-11-10 02:25:56 +01001/*
2 * NETLINK Generic Netlink Family
3 *
4 * Authors: Jamal Hadi Salim
5 * Thomas Graf <tgraf@suug.ch>
Johannes Berg2dbba6f2007-07-18 15:47:52 -07006 * Johannes Berg <johannes@sipsolutions.net>
Thomas Graf482a8522005-11-10 02:25:56 +01007 */
8
Thomas Graf482a8522005-11-10 02:25:56 +01009#include <linux/module.h>
10#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090011#include <linux/slab.h>
Thomas Graf482a8522005-11-10 02:25:56 +010012#include <linux/errno.h>
13#include <linux/types.h>
14#include <linux/socket.h>
15#include <linux/string.h>
16#include <linux/skbuff.h>
Ingo Molnar14cc3e22006-03-26 01:37:14 -080017#include <linux/mutex.h>
Johannes Berg2dbba6f2007-07-18 15:47:52 -070018#include <linux/bitmap.h>
Pravin B Shelardef31172013-04-23 07:48:30 +000019#include <linux/rwsem.h>
Thomas Graf482a8522005-11-10 02:25:56 +010020#include <net/sock.h>
21#include <net/genetlink.h>
22
Ingo Molnar14cc3e22006-03-26 01:37:14 -080023static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
Pravin B Shelardef31172013-04-23 07:48:30 +000024static DECLARE_RWSEM(cb_lock);
Thomas Graf482a8522005-11-10 02:25:56 +010025
Johannes Bergee1c24422015-01-16 11:37:14 +010026atomic_t genl_sk_destructing_cnt = ATOMIC_INIT(0);
27DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq);
28
James Chapmanf408e0c2010-04-02 06:19:05 +000029void genl_lock(void)
Thomas Graf482a8522005-11-10 02:25:56 +010030{
Ingo Molnar14cc3e22006-03-26 01:37:14 -080031 mutex_lock(&genl_mutex);
Thomas Graf482a8522005-11-10 02:25:56 +010032}
James Chapmanf408e0c2010-04-02 06:19:05 +000033EXPORT_SYMBOL(genl_lock);
Thomas Graf482a8522005-11-10 02:25:56 +010034
James Chapmanf408e0c2010-04-02 06:19:05 +000035void genl_unlock(void)
Thomas Graf482a8522005-11-10 02:25:56 +010036{
Ingo Molnar14cc3e22006-03-26 01:37:14 -080037 mutex_unlock(&genl_mutex);
Thomas Graf482a8522005-11-10 02:25:56 +010038}
James Chapmanf408e0c2010-04-02 06:19:05 +000039EXPORT_SYMBOL(genl_unlock);
Thomas Graf482a8522005-11-10 02:25:56 +010040
WANG Cong320f5ea2012-07-24 13:44:01 +080041#ifdef CONFIG_LOCKDEP
Yaowei Bai61d03532015-10-08 21:28:54 +080042bool lockdep_genl_is_held(void)
Pravin B Shelar86b13092011-11-10 19:14:51 -080043{
44 return lockdep_is_held(&genl_mutex);
45}
46EXPORT_SYMBOL(lockdep_genl_is_held);
47#endif
48
Pravin B Shelardef31172013-04-23 07:48:30 +000049static void genl_lock_all(void)
50{
51 down_write(&cb_lock);
52 genl_lock();
53}
54
55static void genl_unlock_all(void)
56{
57 genl_unlock();
58 up_write(&cb_lock);
59}
60
Thomas Graf482a8522005-11-10 02:25:56 +010061#define GENL_FAM_TAB_SIZE 16
62#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
63
64static struct list_head family_ht[GENL_FAM_TAB_SIZE];
Johannes Berg2dbba6f2007-07-18 15:47:52 -070065/*
66 * Bitmap of multicast groups that are currently in use.
67 *
68 * To avoid an allocation at boot of just one unsigned long,
69 * declare it global instead.
70 * Bit 0 is marked as already used since group 0 is invalid.
Johannes Berge5dcecb2013-11-19 15:19:32 +010071 * Bit 1 is marked as already used since the drop-monitor code
72 * abuses the API and thinks it can statically use group 1.
73 * That group will typically conflict with other groups that
74 * any proper users use.
Johannes Berg2a94fe42013-11-19 15:19:39 +010075 * Bit 16 is marked as used since it's used for generic netlink
76 * and the code no longer marks pre-reserved IDs as used.
Johannes Berg2ecf7532013-11-19 15:19:33 +010077 * Bit 17 is marked as already used since the VFS quota code
78 * also abused this API and relied on family == group ID, we
79 * cater to that by giving it a static family and group ID.
Johannes Berg5e53e682013-11-24 21:09:26 +010080 * Bit 18 is marked as already used since the PMCRAID driver
81 * did the same thing as the VFS quota code (maybe copied?)
Johannes Berg2dbba6f2007-07-18 15:47:52 -070082 */
Johannes Berg2a94fe42013-11-19 15:19:39 +010083static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
Johannes Berg5e53e682013-11-24 21:09:26 +010084 BIT(GENL_ID_VFS_DQUOT) |
85 BIT(GENL_ID_PMCRAID);
Johannes Berg2dbba6f2007-07-18 15:47:52 -070086static unsigned long *mc_groups = &mc_group_start;
87static unsigned long mc_groups_longs = 1;
Thomas Graf482a8522005-11-10 02:25:56 +010088
Johannes Bergc2ebb902013-11-19 15:19:36 +010089static int genl_ctrl_event(int event, struct genl_family *family,
Johannes Berg2a94fe42013-11-19 15:19:39 +010090 const struct genl_multicast_group *grp,
91 int grp_id);
Thomas Graf482a8522005-11-10 02:25:56 +010092
93static inline unsigned int genl_family_hash(unsigned int id)
94{
95 return id & GENL_FAM_TAB_MASK;
96}
97
98static inline struct list_head *genl_family_chain(unsigned int id)
99{
100 return &family_ht[genl_family_hash(id)];
101}
102
103static struct genl_family *genl_family_find_byid(unsigned int id)
104{
105 struct genl_family *f;
106
107 list_for_each_entry(f, genl_family_chain(id), family_list)
108 if (f->id == id)
109 return f;
110
111 return NULL;
112}
113
114static struct genl_family *genl_family_find_byname(char *name)
115{
116 struct genl_family *f;
117 int i;
118
119 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
120 list_for_each_entry(f, genl_family_chain(i), family_list)
121 if (strcmp(f->name, name) == 0)
122 return f;
123
124 return NULL;
125}
126
Johannes Bergf84f7712013-11-14 17:14:45 +0100127static const struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
Thomas Graf482a8522005-11-10 02:25:56 +0100128{
Johannes Bergd91824c2013-11-14 17:14:44 +0100129 int i;
Thomas Graf482a8522005-11-10 02:25:56 +0100130
Johannes Bergd91824c2013-11-14 17:14:44 +0100131 for (i = 0; i < family->n_ops; i++)
132 if (family->ops[i].cmd == cmd)
133 return &family->ops[i];
Thomas Graf482a8522005-11-10 02:25:56 +0100134
135 return NULL;
136}
137
138/* Of course we are going to have problems once we hit
139 * 2^16 alive types, but that can only happen by year 2K
140*/
stephen hemmingerb57ef81f2011-12-22 08:52:02 +0000141static u16 genl_generate_id(void)
Thomas Graf482a8522005-11-10 02:25:56 +0100142{
Krishna Kumar988ade62009-10-14 19:55:07 +0000143 static u16 id_gen_idx = GENL_MIN_ID;
144 int i;
Thomas Graf482a8522005-11-10 02:25:56 +0100145
Krishna Kumar988ade62009-10-14 19:55:07 +0000146 for (i = 0; i <= GENL_MAX_ID - GENL_MIN_ID; i++) {
Johannes Berg2ecf7532013-11-19 15:19:33 +0100147 if (id_gen_idx != GENL_ID_VFS_DQUOT &&
Johannes Berg5e53e682013-11-24 21:09:26 +0100148 id_gen_idx != GENL_ID_PMCRAID &&
Johannes Berg2ecf7532013-11-19 15:19:33 +0100149 !genl_family_find_byid(id_gen_idx))
Krishna Kumar988ade62009-10-14 19:55:07 +0000150 return id_gen_idx;
151 if (++id_gen_idx > GENL_MAX_ID)
Thomas Graf482a8522005-11-10 02:25:56 +0100152 id_gen_idx = GENL_MIN_ID;
Krishna Kumar988ade62009-10-14 19:55:07 +0000153 }
Thomas Graf482a8522005-11-10 02:25:56 +0100154
Krishna Kumar988ade62009-10-14 19:55:07 +0000155 return 0;
Thomas Graf482a8522005-11-10 02:25:56 +0100156}
157
Johannes Berg2a94fe42013-11-19 15:19:39 +0100158static int genl_allocate_reserve_groups(int n_groups, int *first_id)
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700159{
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700160 unsigned long *new_groups;
Johannes Berg2a94fe42013-11-19 15:19:39 +0100161 int start = 0;
162 int i;
163 int id;
164 bool fits;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700165
Johannes Berg2a94fe42013-11-19 15:19:39 +0100166 do {
167 if (start == 0)
168 id = find_first_zero_bit(mc_groups,
169 mc_groups_longs *
170 BITS_PER_LONG);
171 else
172 id = find_next_zero_bit(mc_groups,
173 mc_groups_longs * BITS_PER_LONG,
174 start);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700175
Johannes Berg2a94fe42013-11-19 15:19:39 +0100176 fits = true;
177 for (i = id;
178 i < min_t(int, id + n_groups,
179 mc_groups_longs * BITS_PER_LONG);
180 i++) {
181 if (test_bit(i, mc_groups)) {
182 start = i;
183 fits = false;
184 break;
185 }
186 }
187
David S. Millerb8e429a2016-01-13 10:28:06 -0500188 if (id + n_groups > mc_groups_longs * BITS_PER_LONG) {
Johannes Berg2a94fe42013-11-19 15:19:39 +0100189 unsigned long new_longs = mc_groups_longs +
190 BITS_TO_LONGS(n_groups);
191 size_t nlen = new_longs * sizeof(unsigned long);
192
193 if (mc_groups == &mc_group_start) {
194 new_groups = kzalloc(nlen, GFP_KERNEL);
195 if (!new_groups)
196 return -ENOMEM;
197 mc_groups = new_groups;
198 *mc_groups = mc_group_start;
199 } else {
200 new_groups = krealloc(mc_groups, nlen,
201 GFP_KERNEL);
202 if (!new_groups)
203 return -ENOMEM;
204 mc_groups = new_groups;
205 for (i = 0; i < BITS_TO_LONGS(n_groups); i++)
206 mc_groups[mc_groups_longs + i] = 0;
207 }
208 mc_groups_longs = new_longs;
209 }
210 } while (!fits);
211
212 for (i = id; i < id + n_groups; i++)
213 set_bit(i, mc_groups);
214 *first_id = id;
215 return 0;
216}
217
218static struct genl_family genl_ctrl;
219
220static int genl_validate_assign_mc_groups(struct genl_family *family)
221{
222 int first_id;
223 int n_groups = family->n_mcgrps;
Geert Uytterhoeven0f0e2152013-11-23 13:01:50 +0100224 int err = 0, i;
Johannes Berg2a94fe42013-11-19 15:19:39 +0100225 bool groups_allocated = false;
226
227 if (!n_groups)
228 return 0;
229
230 for (i = 0; i < n_groups; i++) {
231 const struct genl_multicast_group *grp = &family->mcgrps[i];
232
233 if (WARN_ON(grp->name[0] == '\0'))
234 return -EINVAL;
235 if (WARN_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL))
236 return -EINVAL;
237 }
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700238
Johannes Berge5dcecb2013-11-19 15:19:32 +0100239 /* special-case our own group and hacks */
Johannes Berg2a94fe42013-11-19 15:19:39 +0100240 if (family == &genl_ctrl) {
241 first_id = GENL_ID_CTRL;
242 BUG_ON(n_groups != 1);
243 } else if (strcmp(family->name, "NET_DM") == 0) {
244 first_id = 1;
245 BUG_ON(n_groups != 1);
Johannes Berg5e53e682013-11-24 21:09:26 +0100246 } else if (family->id == GENL_ID_VFS_DQUOT) {
Johannes Berg2a94fe42013-11-19 15:19:39 +0100247 first_id = GENL_ID_VFS_DQUOT;
248 BUG_ON(n_groups != 1);
Johannes Berg5e53e682013-11-24 21:09:26 +0100249 } else if (family->id == GENL_ID_PMCRAID) {
250 first_id = GENL_ID_PMCRAID;
251 BUG_ON(n_groups != 1);
Johannes Berg2a94fe42013-11-19 15:19:39 +0100252 } else {
253 groups_allocated = true;
254 err = genl_allocate_reserve_groups(n_groups, &first_id);
255 if (err)
256 return err;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700257 }
258
Johannes Berg2a94fe42013-11-19 15:19:39 +0100259 family->mcgrp_offset = first_id;
260
261 /* if still initializing, can't and don't need to to realloc bitmaps */
262 if (!init_net.genl_sock)
263 return 0;
264
Johannes Berg134e6372009-07-10 09:51:34 +0000265 if (family->netnsok) {
266 struct net *net;
267
Johannes Bergd136f1b2009-09-12 03:03:15 +0000268 netlink_table_grab();
Johannes Berg134e6372009-07-10 09:51:34 +0000269 rcu_read_lock();
270 for_each_net_rcu(net) {
Johannes Bergd136f1b2009-09-12 03:03:15 +0000271 err = __netlink_change_ngroups(net->genl_sock,
Johannes Berg134e6372009-07-10 09:51:34 +0000272 mc_groups_longs * BITS_PER_LONG);
273 if (err) {
274 /*
275 * No need to roll back, can only fail if
276 * memory allocation fails and then the
277 * number of _possible_ groups has been
278 * increased on some sockets which is ok.
279 */
Johannes Berg2a94fe42013-11-19 15:19:39 +0100280 break;
Johannes Berg134e6372009-07-10 09:51:34 +0000281 }
282 }
283 rcu_read_unlock();
Johannes Bergd136f1b2009-09-12 03:03:15 +0000284 netlink_table_ungrab();
Johannes Berg134e6372009-07-10 09:51:34 +0000285 } else {
286 err = netlink_change_ngroups(init_net.genl_sock,
287 mc_groups_longs * BITS_PER_LONG);
Johannes Berg134e6372009-07-10 09:51:34 +0000288 }
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700289
Johannes Berg2a94fe42013-11-19 15:19:39 +0100290 if (groups_allocated && err) {
291 for (i = 0; i < family->n_mcgrps; i++)
292 clear_bit(family->mcgrp_offset + i, mc_groups);
293 }
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700294
Thomas Graf79d310d2007-07-24 15:34:53 -0700295 return err;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700296}
Thomas Graf79dc43862007-07-24 15:32:46 -0700297
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700298static void genl_unregister_mc_groups(struct genl_family *family)
299{
Johannes Berg2a94fe42013-11-19 15:19:39 +0100300 struct net *net;
301 int i;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700302
Johannes Berg2a94fe42013-11-19 15:19:39 +0100303 netlink_table_grab();
304 rcu_read_lock();
305 for_each_net_rcu(net) {
306 for (i = 0; i < family->n_mcgrps; i++)
307 __netlink_clear_multicast_users(
308 net->genl_sock, family->mcgrp_offset + i);
309 }
310 rcu_read_unlock();
311 netlink_table_ungrab();
312
313 for (i = 0; i < family->n_mcgrps; i++) {
314 int grp_id = family->mcgrp_offset + i;
315
316 if (grp_id != 1)
317 clear_bit(grp_id, mc_groups);
318 genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family,
319 &family->mcgrps[i], grp_id);
320 }
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700321}
322
Denis ChengRq2f91abd2014-06-02 01:18:01 -0700323static int genl_validate_ops(const struct genl_family *family)
Thomas Graf482a8522005-11-10 02:25:56 +0100324{
Johannes Berg568508a2013-11-15 14:19:08 +0100325 const struct genl_ops *ops = family->ops;
326 unsigned int n_ops = family->n_ops;
Johannes Bergd91824c2013-11-14 17:14:44 +0100327 int i, j;
Thomas Graf482a8522005-11-10 02:25:56 +0100328
Johannes Berg568508a2013-11-15 14:19:08 +0100329 if (WARN_ON(n_ops && !ops))
330 return -EINVAL;
331
332 if (!n_ops)
333 return 0;
334
Johannes Bergd91824c2013-11-14 17:14:44 +0100335 for (i = 0; i < n_ops; i++) {
336 if (ops[i].dumpit == NULL && ops[i].doit == NULL)
337 return -EINVAL;
338 for (j = i + 1; j < n_ops; j++)
339 if (ops[i].cmd == ops[j].cmd)
340 return -EINVAL;
Thomas Graf482a8522005-11-10 02:25:56 +0100341 }
342
Johannes Bergd91824c2013-11-14 17:14:44 +0100343 return 0;
Thomas Graf482a8522005-11-10 02:25:56 +0100344}
Thomas Graf482a8522005-11-10 02:25:56 +0100345
346/**
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700347 * __genl_register_family - register a generic netlink family
Thomas Graf482a8522005-11-10 02:25:56 +0100348 * @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 *
Johannes Berg568508a2013-11-15 14:19:08 +0100355 * The family's ops array must already be assigned, you can use the
356 * genl_register_family_with_ops() helper function.
357 *
Thomas Graf482a8522005-11-10 02:25:56 +0100358 * Return 0 on success or a negative error code.
359 */
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700360int __genl_register_family(struct genl_family *family)
Thomas Graf482a8522005-11-10 02:25:56 +0100361{
Johannes Berg2a94fe42013-11-19 15:19:39 +0100362 int err = -EINVAL, i;
Thomas Graf482a8522005-11-10 02:25:56 +0100363
364 if (family->id && family->id < GENL_MIN_ID)
365 goto errout;
366
367 if (family->id > GENL_MAX_ID)
368 goto errout;
369
Johannes Berg568508a2013-11-15 14:19:08 +0100370 err = genl_validate_ops(family);
371 if (err)
372 return err;
373
Pravin B Shelardef31172013-04-23 07:48:30 +0000374 genl_lock_all();
Thomas Graf482a8522005-11-10 02:25:56 +0100375
376 if (genl_family_find_byname(family->name)) {
377 err = -EEXIST;
378 goto errout_locked;
379 }
380
Thomas Graf482a8522005-11-10 02:25:56 +0100381 if (family->id == GENL_ID_GENERATE) {
382 u16 newid = genl_generate_id();
383
384 if (!newid) {
385 err = -ENOMEM;
386 goto errout_locked;
387 }
388
389 family->id = newid;
Krishna Kumar93860b02009-10-14 19:54:53 +0000390 } else if (genl_family_find_byid(family->id)) {
391 err = -EEXIST;
392 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100393 }
394
Pravin B Shelardef31172013-04-23 07:48:30 +0000395 if (family->maxattr && !family->parallel_ops) {
Thomas Graf482a8522005-11-10 02:25:56 +0100396 family->attrbuf = kmalloc((family->maxattr+1) *
397 sizeof(struct nlattr *), GFP_KERNEL);
398 if (family->attrbuf == NULL) {
399 err = -ENOMEM;
Jamal Hadi Salime200bd82006-02-13 15:51:24 -0800400 goto errout_locked;
Thomas Graf482a8522005-11-10 02:25:56 +0100401 }
402 } else
403 family->attrbuf = NULL;
404
Johannes Berg2a94fe42013-11-19 15:19:39 +0100405 err = genl_validate_assign_mc_groups(family);
406 if (err)
407 goto errout_locked;
408
Thomas Graf482a8522005-11-10 02:25:56 +0100409 list_add_tail(&family->family_list, genl_family_chain(family->id));
Pravin B Shelardef31172013-04-23 07:48:30 +0000410 genl_unlock_all();
Thomas Graf482a8522005-11-10 02:25:56 +0100411
Johannes Berg2a94fe42013-11-19 15:19:39 +0100412 /* send all events */
413 genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
414 for (i = 0; i < family->n_mcgrps; i++)
415 genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
416 &family->mcgrps[i], family->mcgrp_offset + i);
Thomas Graf482a8522005-11-10 02:25:56 +0100417
418 return 0;
419
420errout_locked:
Pravin B Shelardef31172013-04-23 07:48:30 +0000421 genl_unlock_all();
Thomas Graf482a8522005-11-10 02:25:56 +0100422errout:
423 return err;
424}
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700425EXPORT_SYMBOL(__genl_register_family);
Thomas Graf482a8522005-11-10 02:25:56 +0100426
427/**
428 * genl_unregister_family - unregister generic netlink family
429 * @family: generic netlink family
430 *
431 * Unregisters the specified family.
432 *
433 * Returns 0 on success or a negative error code.
434 */
435int genl_unregister_family(struct genl_family *family)
436{
437 struct genl_family *rc;
438
Pravin B Shelardef31172013-04-23 07:48:30 +0000439 genl_lock_all();
Thomas Graf482a8522005-11-10 02:25:56 +0100440
441 list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
442 if (family->id != rc->id || strcmp(rc->name, family->name))
443 continue;
444
Johannes Bergee1c24422015-01-16 11:37:14 +0100445 genl_unregister_mc_groups(family);
446
Thomas Graf482a8522005-11-10 02:25:56 +0100447 list_del(&rc->family_list);
Johannes Bergd91824c2013-11-14 17:14:44 +0100448 family->n_ops = 0;
Johannes Bergee1c24422015-01-16 11:37:14 +0100449 up_write(&cb_lock);
450 wait_event(genl_sk_destructing_waitq,
451 atomic_read(&genl_sk_destructing_cnt) == 0);
452 genl_unlock();
Thomas Graf482a8522005-11-10 02:25:56 +0100453
Thomas Graf482a8522005-11-10 02:25:56 +0100454 kfree(family->attrbuf);
Johannes Berg2a94fe42013-11-19 15:19:39 +0100455 genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
Thomas Graf482a8522005-11-10 02:25:56 +0100456 return 0;
457 }
458
Pravin B Shelardef31172013-04-23 07:48:30 +0000459 genl_unlock_all();
Thomas Graf482a8522005-11-10 02:25:56 +0100460
461 return -ENOENT;
462}
Changli Gao416c2f92010-07-25 20:46:01 +0000463EXPORT_SYMBOL(genl_unregister_family);
Thomas Graf482a8522005-11-10 02:25:56 +0100464
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500465/**
466 * genlmsg_put - Add generic netlink header to netlink message
467 * @skb: socket buffer holding the message
Eric W. Biederman15e47302012-09-07 20:12:54 +0000468 * @portid: netlink portid the message is addressed to
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500469 * @seq: sequence number (usually the one of the sender)
470 * @family: generic netlink family
Ben Hutchings2c530402012-07-10 10:55:09 +0000471 * @flags: netlink message flags
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500472 * @cmd: generic netlink command
473 *
474 * Returns pointer to user specific header
475 */
Eric W. Biederman15e47302012-09-07 20:12:54 +0000476void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500477 struct genl_family *family, int flags, u8 cmd)
478{
479 struct nlmsghdr *nlh;
480 struct genlmsghdr *hdr;
481
Eric W. Biederman15e47302012-09-07 20:12:54 +0000482 nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
Denys Vlasenkoa46621a2012-01-30 15:22:06 -0500483 family->hdrsize, flags);
484 if (nlh == NULL)
485 return NULL;
486
487 hdr = nlmsg_data(nlh);
488 hdr->cmd = cmd;
489 hdr->version = family->version;
490 hdr->reserved = 0;
491
492 return (char *) hdr + GENL_HDRLEN;
493}
494EXPORT_SYMBOL(genlmsg_put);
495
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800496static int genl_lock_start(struct netlink_callback *cb)
497{
498 /* our ops are always const - netlink API doesn't propagate that */
499 const struct genl_ops *ops = cb->data;
500 int rc = 0;
501
502 if (ops->start) {
503 genl_lock();
504 rc = ops->start(cb);
505 genl_unlock();
506 }
507 return rc;
508}
509
Pravin B Shelar9b963092013-08-23 12:44:55 -0700510static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
511{
Johannes Bergf84f7712013-11-14 17:14:45 +0100512 /* our ops are always const - netlink API doesn't propagate that */
513 const struct genl_ops *ops = cb->data;
Pravin B Shelar9b963092013-08-23 12:44:55 -0700514 int rc;
515
516 genl_lock();
517 rc = ops->dumpit(skb, cb);
518 genl_unlock();
519 return rc;
520}
521
522static int genl_lock_done(struct netlink_callback *cb)
523{
Johannes Bergf84f7712013-11-14 17:14:45 +0100524 /* our ops are always const - netlink API doesn't propagate that */
525 const struct genl_ops *ops = cb->data;
Pravin B Shelar9b963092013-08-23 12:44:55 -0700526 int rc = 0;
527
528 if (ops->done) {
529 genl_lock();
530 rc = ops->done(cb);
531 genl_unlock();
532 }
533 return rc;
534}
535
Pravin B Shelardef31172013-04-23 07:48:30 +0000536static int genl_family_rcv_msg(struct genl_family *family,
537 struct sk_buff *skb,
538 struct nlmsghdr *nlh)
Thomas Graf482a8522005-11-10 02:25:56 +0100539{
Johannes Bergf84f7712013-11-14 17:14:45 +0100540 const struct genl_ops *ops;
Johannes Berg134e6372009-07-10 09:51:34 +0000541 struct net *net = sock_net(skb->sk);
Thomas Graf482a8522005-11-10 02:25:56 +0100542 struct genl_info info;
543 struct genlmsghdr *hdr = nlmsg_data(nlh);
Pravin B Shelardef31172013-04-23 07:48:30 +0000544 struct nlattr **attrbuf;
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700545 int hdrlen, err;
Thomas Graf482a8522005-11-10 02:25:56 +0100546
Johannes Berg134e6372009-07-10 09:51:34 +0000547 /* this family doesn't exist in this netns */
548 if (!family->netnsok && !net_eq(net, &init_net))
549 return -ENOENT;
550
Thomas Graf482a8522005-11-10 02:25:56 +0100551 hdrlen = GENL_HDRLEN + family->hdrsize;
552 if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700553 return -EINVAL;
Thomas Graf482a8522005-11-10 02:25:56 +0100554
555 ops = genl_get_cmd(hdr->cmd, family);
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700556 if (ops == NULL)
557 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100558
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700559 if ((ops->flags & GENL_ADMIN_PERM) &&
Eric W. Biederman90f62cf2014-04-23 14:29:27 -0700560 !netlink_capable(skb, CAP_NET_ADMIN))
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700561 return -EPERM;
Thomas Graf482a8522005-11-10 02:25:56 +0100562
Tycho Andersen4a926022016-02-05 09:20:52 -0700563 if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
564 !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
565 return -EPERM;
566
Pablo Neirae1ee3672013-07-29 12:30:04 +0200567 if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
Pravin B Shelar9b963092013-08-23 12:44:55 -0700568 int rc;
Pravin B Shelardef31172013-04-23 07:48:30 +0000569
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700570 if (ops->dumpit == NULL)
571 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100572
Pravin B Shelar9b963092013-08-23 12:44:55 -0700573 if (!family->parallel_ops) {
574 struct netlink_dump_control c = {
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700575 .module = family->module,
Johannes Bergf84f7712013-11-14 17:14:45 +0100576 /* we have const, but the netlink API doesn't */
577 .data = (void *)ops,
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800578 .start = genl_lock_start,
Pravin B Shelar9b963092013-08-23 12:44:55 -0700579 .dump = genl_lock_dumpit,
580 .done = genl_lock_done,
581 };
582
583 genl_unlock();
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700584 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
Pravin B Shelar9b963092013-08-23 12:44:55 -0700585 genl_lock();
586
587 } else {
588 struct netlink_dump_control c = {
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700589 .module = family->module,
Tom Herbertfc9e50f2015-12-15 15:41:37 -0800590 .start = ops->start,
Pravin B Shelar9b963092013-08-23 12:44:55 -0700591 .dump = ops->dumpit,
592 .done = ops->done,
593 };
594
Pravin B Shelar33c6b1f2013-08-23 12:45:04 -0700595 rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
Pravin B Shelar9b963092013-08-23 12:44:55 -0700596 }
597
598 return rc;
Thomas Graf482a8522005-11-10 02:25:56 +0100599 }
600
Thomas Graf1d00a4e2007-03-22 23:30:12 -0700601 if (ops->doit == NULL)
602 return -EOPNOTSUPP;
Thomas Graf482a8522005-11-10 02:25:56 +0100603
Pravin B Shelardef31172013-04-23 07:48:30 +0000604 if (family->maxattr && family->parallel_ops) {
605 attrbuf = kmalloc((family->maxattr+1) *
606 sizeof(struct nlattr *), GFP_KERNEL);
607 if (attrbuf == NULL)
608 return -ENOMEM;
609 } else
610 attrbuf = family->attrbuf;
611
612 if (attrbuf) {
613 err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
Thomas Graf482a8522005-11-10 02:25:56 +0100614 ops->policy);
615 if (err < 0)
Wei Yongjun50754d212013-04-26 15:34:16 +0000616 goto out;
Thomas Graf482a8522005-11-10 02:25:56 +0100617 }
618
619 info.snd_seq = nlh->nlmsg_seq;
Eric W. Biederman15e47302012-09-07 20:12:54 +0000620 info.snd_portid = NETLINK_CB(skb).portid;
Thomas Graf482a8522005-11-10 02:25:56 +0100621 info.nlhdr = nlh;
622 info.genlhdr = nlmsg_data(nlh);
623 info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
Pravin B Shelardef31172013-04-23 07:48:30 +0000624 info.attrs = attrbuf;
Johannes Berg134e6372009-07-10 09:51:34 +0000625 genl_info_net_set(&info, net);
Johannes Bergff4c92d2010-10-04 21:14:03 +0200626 memset(&info.user_ptr, 0, sizeof(info.user_ptr));
Thomas Graf482a8522005-11-10 02:25:56 +0100627
Johannes Bergff4c92d2010-10-04 21:14:03 +0200628 if (family->pre_doit) {
629 err = family->pre_doit(ops, skb, &info);
630 if (err)
Wei Yongjun50754d212013-04-26 15:34:16 +0000631 goto out;
Johannes Bergff4c92d2010-10-04 21:14:03 +0200632 }
633
634 err = ops->doit(skb, &info);
635
636 if (family->post_doit)
637 family->post_doit(ops, skb, &info);
638
Wei Yongjun50754d212013-04-26 15:34:16 +0000639out:
Pravin B Shelardef31172013-04-23 07:48:30 +0000640 if (family->parallel_ops)
641 kfree(attrbuf);
642
643 return err;
644}
645
646static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
647{
648 struct genl_family *family;
649 int err;
650
651 family = genl_family_find_byid(nlh->nlmsg_type);
652 if (family == NULL)
653 return -ENOENT;
654
655 if (!family->parallel_ops)
656 genl_lock();
657
658 err = genl_family_rcv_msg(family, skb, nlh);
659
660 if (!family->parallel_ops)
661 genl_unlock();
662
Johannes Bergff4c92d2010-10-04 21:14:03 +0200663 return err;
Thomas Graf482a8522005-11-10 02:25:56 +0100664}
665
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700666static void genl_rcv(struct sk_buff *skb)
Thomas Graf482a8522005-11-10 02:25:56 +0100667{
Pravin B Shelardef31172013-04-23 07:48:30 +0000668 down_read(&cb_lock);
Denis V. Lunevcd40b7d2007-10-10 21:15:29 -0700669 netlink_rcv_skb(skb, &genl_rcv_msg);
Pravin B Shelardef31172013-04-23 07:48:30 +0000670 up_read(&cb_lock);
Thomas Graf482a8522005-11-10 02:25:56 +0100671}
672
673/**************************************************************************
674 * Controller
675 **************************************************************************/
676
Thomas Graf17c157c2006-11-14 19:46:02 -0800677static struct genl_family genl_ctrl = {
678 .id = GENL_ID_CTRL,
679 .name = "nlctrl",
Jamal Hadi Salim334c29a2006-12-04 19:31:51 -0800680 .version = 0x2,
Thomas Graf17c157c2006-11-14 19:46:02 -0800681 .maxattr = CTRL_ATTR_MAX,
Johannes Berg134e6372009-07-10 09:51:34 +0000682 .netnsok = true,
Thomas Graf17c157c2006-11-14 19:46:02 -0800683};
684
Eric W. Biederman15e47302012-09-07 20:12:54 +0000685static int ctrl_fill_info(struct genl_family *family, u32 portid, u32 seq,
Thomas Graf482a8522005-11-10 02:25:56 +0100686 u32 flags, struct sk_buff *skb, u8 cmd)
687{
688 void *hdr;
689
Eric W. Biederman15e47302012-09-07 20:12:54 +0000690 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
Thomas Graf482a8522005-11-10 02:25:56 +0100691 if (hdr == NULL)
692 return -1;
693
David S. Miller444653f2012-03-29 23:25:11 -0400694 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
695 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) ||
696 nla_put_u32(skb, CTRL_ATTR_VERSION, family->version) ||
697 nla_put_u32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize) ||
698 nla_put_u32(skb, CTRL_ATTR_MAXATTR, family->maxattr))
699 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700700
Johannes Bergd91824c2013-11-14 17:14:44 +0100701 if (family->n_ops) {
Thomas Grafe94ef682006-11-23 11:44:37 -0800702 struct nlattr *nla_ops;
Johannes Bergd91824c2013-11-14 17:14:44 +0100703 int i;
Thomas Grafeb328112006-09-18 00:01:59 -0700704
Thomas Grafe94ef682006-11-23 11:44:37 -0800705 nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
706 if (nla_ops == NULL)
Thomas Grafeb328112006-09-18 00:01:59 -0700707 goto nla_put_failure;
708
Johannes Bergd91824c2013-11-14 17:14:44 +0100709 for (i = 0; i < family->n_ops; i++) {
Thomas Grafe94ef682006-11-23 11:44:37 -0800710 struct nlattr *nest;
Johannes Bergf84f7712013-11-14 17:14:45 +0100711 const struct genl_ops *ops = &family->ops[i];
Johannes Berg029b2342013-11-18 20:54:58 +0100712 u32 op_flags = ops->flags;
Johannes Bergf84f7712013-11-14 17:14:45 +0100713
714 if (ops->dumpit)
Johannes Berg029b2342013-11-18 20:54:58 +0100715 op_flags |= GENL_CMD_CAP_DUMP;
Johannes Bergf84f7712013-11-14 17:14:45 +0100716 if (ops->doit)
Johannes Berg029b2342013-11-18 20:54:58 +0100717 op_flags |= GENL_CMD_CAP_DO;
Johannes Bergf84f7712013-11-14 17:14:45 +0100718 if (ops->policy)
Johannes Berg029b2342013-11-18 20:54:58 +0100719 op_flags |= GENL_CMD_CAP_HASPOL;
Thomas Grafeb328112006-09-18 00:01:59 -0700720
Johannes Bergd91824c2013-11-14 17:14:44 +0100721 nest = nla_nest_start(skb, i + 1);
Thomas Grafe94ef682006-11-23 11:44:37 -0800722 if (nest == NULL)
723 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700724
David S. Miller444653f2012-03-29 23:25:11 -0400725 if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
Johannes Berg029b2342013-11-18 20:54:58 +0100726 nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
David S. Miller444653f2012-03-29 23:25:11 -0400727 goto nla_put_failure;
Thomas Grafeb328112006-09-18 00:01:59 -0700728
Thomas Grafe94ef682006-11-23 11:44:37 -0800729 nla_nest_end(skb, nest);
730 }
731
732 nla_nest_end(skb, nla_ops);
Thomas Grafeb328112006-09-18 00:01:59 -0700733 }
734
Johannes Berg2a94fe42013-11-19 15:19:39 +0100735 if (family->n_mcgrps) {
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700736 struct nlattr *nla_grps;
Johannes Berg2a94fe42013-11-19 15:19:39 +0100737 int i;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700738
739 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
740 if (nla_grps == NULL)
741 goto nla_put_failure;
742
Johannes Berg2a94fe42013-11-19 15:19:39 +0100743 for (i = 0; i < family->n_mcgrps; i++) {
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700744 struct nlattr *nest;
Johannes Berg2a94fe42013-11-19 15:19:39 +0100745 const struct genl_multicast_group *grp;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700746
Johannes Berg2a94fe42013-11-19 15:19:39 +0100747 grp = &family->mcgrps[i];
748
749 nest = nla_nest_start(skb, i + 1);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700750 if (nest == NULL)
751 goto nla_put_failure;
752
Johannes Berg2a94fe42013-11-19 15:19:39 +0100753 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
754 family->mcgrp_offset + i) ||
David S. Miller444653f2012-03-29 23:25:11 -0400755 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
756 grp->name))
757 goto nla_put_failure;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700758
759 nla_nest_end(skb, nest);
760 }
761 nla_nest_end(skb, nla_grps);
762 }
763
Johannes Berg053c0952015-01-16 22:09:00 +0100764 genlmsg_end(skb, hdr);
765 return 0;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700766
767nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700768 genlmsg_cancel(skb, hdr);
769 return -EMSGSIZE;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700770}
771
Johannes Bergc2ebb902013-11-19 15:19:36 +0100772static int ctrl_fill_mcgrp_info(struct genl_family *family,
Johannes Berg2a94fe42013-11-19 15:19:39 +0100773 const struct genl_multicast_group *grp,
774 int grp_id, u32 portid, u32 seq, u32 flags,
775 struct sk_buff *skb, u8 cmd)
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700776{
777 void *hdr;
778 struct nlattr *nla_grps;
779 struct nlattr *nest;
780
Eric W. Biederman15e47302012-09-07 20:12:54 +0000781 hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700782 if (hdr == NULL)
783 return -1;
784
Johannes Bergc2ebb902013-11-19 15:19:36 +0100785 if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
786 nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
David S. Miller444653f2012-03-29 23:25:11 -0400787 goto nla_put_failure;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700788
789 nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
790 if (nla_grps == NULL)
791 goto nla_put_failure;
792
793 nest = nla_nest_start(skb, 1);
794 if (nest == NULL)
795 goto nla_put_failure;
796
Johannes Berg2a94fe42013-11-19 15:19:39 +0100797 if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
David S. Miller444653f2012-03-29 23:25:11 -0400798 nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
799 grp->name))
800 goto nla_put_failure;
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700801
802 nla_nest_end(skb, nest);
803 nla_nest_end(skb, nla_grps);
804
Johannes Berg053c0952015-01-16 22:09:00 +0100805 genlmsg_end(skb, hdr);
806 return 0;
Thomas Graf482a8522005-11-10 02:25:56 +0100807
808nla_put_failure:
Thomas Grafbc3ed282008-06-03 16:36:54 -0700809 genlmsg_cancel(skb, hdr);
810 return -EMSGSIZE;
Thomas Graf482a8522005-11-10 02:25:56 +0100811}
812
813static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
814{
815
816 int i, n = 0;
817 struct genl_family *rt;
Johannes Berg134e6372009-07-10 09:51:34 +0000818 struct net *net = sock_net(skb->sk);
Thomas Graf482a8522005-11-10 02:25:56 +0100819 int chains_to_skip = cb->args[0];
820 int fams_to_skip = cb->args[1];
821
Samir Bellabese1d5a012010-01-07 22:10:56 +0000822 for (i = chains_to_skip; i < GENL_FAM_TAB_SIZE; i++) {
Thomas Graf482a8522005-11-10 02:25:56 +0100823 n = 0;
824 list_for_each_entry(rt, genl_family_chain(i), family_list) {
Johannes Berg134e6372009-07-10 09:51:34 +0000825 if (!rt->netnsok && !net_eq(net, &init_net))
826 continue;
Thomas Graf482a8522005-11-10 02:25:56 +0100827 if (++n < fams_to_skip)
828 continue;
Eric W. Biederman15e47302012-09-07 20:12:54 +0000829 if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
Thomas Graf482a8522005-11-10 02:25:56 +0100830 cb->nlh->nlmsg_seq, NLM_F_MULTI,
831 skb, CTRL_CMD_NEWFAMILY) < 0)
832 goto errout;
833 }
834
835 fams_to_skip = 0;
836 }
837
838errout:
839 cb->args[0] = i;
840 cb->args[1] = n;
841
842 return skb->len;
843}
844
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700845static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
Eric W. Biederman15e47302012-09-07 20:12:54 +0000846 u32 portid, int seq, u8 cmd)
Thomas Graf482a8522005-11-10 02:25:56 +0100847{
848 struct sk_buff *skb;
849 int err;
850
Thomas Graf339bf982006-11-10 14:10:15 -0800851 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
Thomas Graf482a8522005-11-10 02:25:56 +0100852 if (skb == NULL)
853 return ERR_PTR(-ENOBUFS);
854
Eric W. Biederman15e47302012-09-07 20:12:54 +0000855 err = ctrl_fill_info(family, portid, seq, 0, skb, cmd);
Thomas Graf482a8522005-11-10 02:25:56 +0100856 if (err < 0) {
857 nlmsg_free(skb);
858 return ERR_PTR(err);
859 }
860
861 return skb;
862}
863
Johannes Berg2a94fe42013-11-19 15:19:39 +0100864static struct sk_buff *
865ctrl_build_mcgrp_msg(struct genl_family *family,
866 const struct genl_multicast_group *grp,
867 int grp_id, u32 portid, int seq, u8 cmd)
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700868{
869 struct sk_buff *skb;
870 int err;
871
872 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
873 if (skb == NULL)
874 return ERR_PTR(-ENOBUFS);
875
Johannes Berg2a94fe42013-11-19 15:19:39 +0100876 err = ctrl_fill_mcgrp_info(family, grp, grp_id, portid,
877 seq, 0, skb, cmd);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700878 if (err < 0) {
879 nlmsg_free(skb);
880 return ERR_PTR(err);
881 }
882
883 return skb;
884}
885
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700886static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
Thomas Graf482a8522005-11-10 02:25:56 +0100887 [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
Thomas Graf5176f912006-08-26 20:13:18 -0700888 [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
889 .len = GENL_NAMSIZ - 1 },
Thomas Graf482a8522005-11-10 02:25:56 +0100890};
891
892static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
893{
894 struct sk_buff *msg;
895 struct genl_family *res = NULL;
896 int err = -EINVAL;
897
898 if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
899 u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
900 res = genl_family_find_byid(id);
Johannes Berg134e6372009-07-10 09:51:34 +0000901 err = -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100902 }
903
904 if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
Thomas Graf5176f912006-08-26 20:13:18 -0700905 char *name;
Thomas Graf482a8522005-11-10 02:25:56 +0100906
Thomas Graf5176f912006-08-26 20:13:18 -0700907 name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
Thomas Graf482a8522005-11-10 02:25:56 +0100908 res = genl_family_find_byname(name);
Stephen Hemmingerfa843092011-12-28 13:48:55 -0500909#ifdef CONFIG_MODULES
910 if (res == NULL) {
911 genl_unlock();
Stanislaw Gruszkac74f2b22013-07-26 11:00:10 +0200912 up_read(&cb_lock);
Neil Hormane9412c32012-05-29 09:30:41 +0000913 request_module("net-pf-%d-proto-%d-family-%s",
Stephen Hemmingerfa843092011-12-28 13:48:55 -0500914 PF_NETLINK, NETLINK_GENERIC, name);
Stanislaw Gruszkac74f2b22013-07-26 11:00:10 +0200915 down_read(&cb_lock);
Stephen Hemmingerfa843092011-12-28 13:48:55 -0500916 genl_lock();
917 res = genl_family_find_byname(name);
918 }
919#endif
Johannes Berg134e6372009-07-10 09:51:34 +0000920 err = -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100921 }
922
Johannes Berg134e6372009-07-10 09:51:34 +0000923 if (res == NULL)
924 return err;
925
926 if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
927 /* family doesn't exist here */
928 return -ENOENT;
Thomas Graf482a8522005-11-10 02:25:56 +0100929 }
930
Eric W. Biederman15e47302012-09-07 20:12:54 +0000931 msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700932 CTRL_CMD_NEWFAMILY);
Johannes Berg134e6372009-07-10 09:51:34 +0000933 if (IS_ERR(msg))
934 return PTR_ERR(msg);
Thomas Graf482a8522005-11-10 02:25:56 +0100935
Johannes Berg134e6372009-07-10 09:51:34 +0000936 return genlmsg_reply(msg, info);
Thomas Graf482a8522005-11-10 02:25:56 +0100937}
938
Johannes Bergc2ebb902013-11-19 15:19:36 +0100939static int genl_ctrl_event(int event, struct genl_family *family,
Johannes Berg2a94fe42013-11-19 15:19:39 +0100940 const struct genl_multicast_group *grp,
941 int grp_id)
Thomas Graf482a8522005-11-10 02:25:56 +0100942{
943 struct sk_buff *msg;
944
Johannes Berg134e6372009-07-10 09:51:34 +0000945 /* genl is still initialising */
946 if (!init_net.genl_sock)
Thomas Graf482a8522005-11-10 02:25:56 +0100947 return 0;
948
949 switch (event) {
950 case CTRL_CMD_NEWFAMILY:
951 case CTRL_CMD_DELFAMILY:
Johannes Bergc2ebb902013-11-19 15:19:36 +0100952 WARN_ON(grp);
Johannes Berg134e6372009-07-10 09:51:34 +0000953 msg = ctrl_build_family_msg(family, 0, 0, event);
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700954 break;
955 case CTRL_CMD_NEWMCAST_GRP:
956 case CTRL_CMD_DELMCAST_GRP:
Johannes Bergc2ebb902013-11-19 15:19:36 +0100957 BUG_ON(!grp);
Johannes Berg2a94fe42013-11-19 15:19:39 +0100958 msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
Thomas Graf482a8522005-11-10 02:25:56 +0100959 break;
Johannes Berg134e6372009-07-10 09:51:34 +0000960 default:
961 return -EINVAL;
962 }
963
964 if (IS_ERR(msg))
965 return PTR_ERR(msg);
966
967 if (!family->netnsok) {
Johannes Berg68eb5502013-11-19 15:19:38 +0100968 genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
Johannes Berg2a94fe42013-11-19 15:19:39 +0100969 0, GFP_KERNEL);
Johannes Berg134e6372009-07-10 09:51:34 +0000970 } else {
971 rcu_read_lock();
Johannes Berg68eb5502013-11-19 15:19:38 +0100972 genlmsg_multicast_allns(&genl_ctrl, msg, 0,
Johannes Berg2a94fe42013-11-19 15:19:39 +0100973 0, GFP_ATOMIC);
Johannes Berg134e6372009-07-10 09:51:34 +0000974 rcu_read_unlock();
Thomas Graf482a8522005-11-10 02:25:56 +0100975 }
976
977 return 0;
978}
979
Johannes Bergc53ed742013-11-19 15:19:31 +0100980static struct genl_ops genl_ctrl_ops[] = {
981 {
982 .cmd = CTRL_CMD_GETFAMILY,
983 .doit = ctrl_getfamily,
984 .dumpit = ctrl_dumpfamily,
985 .policy = ctrl_policy,
986 },
Thomas Graf482a8522005-11-10 02:25:56 +0100987};
988
Johannes Berg2a94fe42013-11-19 15:19:39 +0100989static struct genl_multicast_group genl_ctrl_groups[] = {
990 { .name = "notify", },
Johannes Berg2dbba6f2007-07-18 15:47:52 -0700991};
992
Johannes Berg023e2cf2014-12-23 21:00:06 +0100993static int genl_bind(struct net *net, int group)
Johannes Bergc380d9a2014-12-23 20:54:40 +0100994{
Johannes Berg5ad63002015-01-16 11:37:13 +0100995 int i, err = -ENOENT;
Johannes Bergc380d9a2014-12-23 20:54:40 +0100996
997 down_read(&cb_lock);
998 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
999 struct genl_family *f;
1000
1001 list_for_each_entry(f, genl_family_chain(i), family_list) {
1002 if (group >= f->mcgrp_offset &&
1003 group < f->mcgrp_offset + f->n_mcgrps) {
1004 int fam_grp = group - f->mcgrp_offset;
1005
Johannes Berg023e2cf2014-12-23 21:00:06 +01001006 if (!f->netnsok && net != &init_net)
1007 err = -ENOENT;
1008 else if (f->mcast_bind)
1009 err = f->mcast_bind(net, fam_grp);
Johannes Bergc380d9a2014-12-23 20:54:40 +01001010 else
1011 err = 0;
Johannes Bergc380d9a2014-12-23 20:54:40 +01001012 break;
1013 }
1014 }
1015 }
1016 up_read(&cb_lock);
1017
Johannes Bergc380d9a2014-12-23 20:54:40 +01001018 return err;
1019}
1020
Johannes Berg023e2cf2014-12-23 21:00:06 +01001021static void genl_unbind(struct net *net, int group)
Johannes Bergc380d9a2014-12-23 20:54:40 +01001022{
1023 int i;
Johannes Bergc380d9a2014-12-23 20:54:40 +01001024
1025 down_read(&cb_lock);
1026 for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
1027 struct genl_family *f;
1028
1029 list_for_each_entry(f, genl_family_chain(i), family_list) {
1030 if (group >= f->mcgrp_offset &&
1031 group < f->mcgrp_offset + f->n_mcgrps) {
1032 int fam_grp = group - f->mcgrp_offset;
1033
1034 if (f->mcast_unbind)
Johannes Berg023e2cf2014-12-23 21:00:06 +01001035 f->mcast_unbind(net, fam_grp);
Johannes Bergc380d9a2014-12-23 20:54:40 +01001036 break;
1037 }
1038 }
1039 }
1040 up_read(&cb_lock);
Johannes Bergc380d9a2014-12-23 20:54:40 +01001041}
1042
Johannes Berg134e6372009-07-10 09:51:34 +00001043static int __net_init genl_pernet_init(struct net *net)
1044{
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +00001045 struct netlink_kernel_cfg cfg = {
1046 .input = genl_rcv,
Pablo Neira Ayuso9785e102012-09-08 02:53:53 +00001047 .flags = NL_CFG_F_NONROOT_RECV,
Johannes Bergc380d9a2014-12-23 20:54:40 +01001048 .bind = genl_bind,
1049 .unbind = genl_unbind,
Pablo Neira Ayusoa31f2d12012-06-29 06:15:21 +00001050 };
1051
Johannes Berg134e6372009-07-10 09:51:34 +00001052 /* we'll bump the group number right afterwards */
Pablo Neira Ayuso9f00d972012-09-08 02:53:54 +00001053 net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
Johannes Berg134e6372009-07-10 09:51:34 +00001054
1055 if (!net->genl_sock && net_eq(net, &init_net))
1056 panic("GENL: Cannot initialize generic netlink\n");
1057
1058 if (!net->genl_sock)
1059 return -ENOMEM;
1060
1061 return 0;
1062}
1063
1064static void __net_exit genl_pernet_exit(struct net *net)
1065{
1066 netlink_kernel_release(net->genl_sock);
1067 net->genl_sock = NULL;
1068}
1069
1070static struct pernet_operations genl_pernet_ops = {
1071 .init = genl_pernet_init,
1072 .exit = genl_pernet_exit,
1073};
1074
Thomas Graf482a8522005-11-10 02:25:56 +01001075static int __init genl_init(void)
1076{
1077 int i, err;
1078
1079 for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
1080 INIT_LIST_HEAD(&family_ht[i]);
1081
Johannes Berg2a94fe42013-11-19 15:19:39 +01001082 err = genl_register_family_with_ops_groups(&genl_ctrl, genl_ctrl_ops,
1083 genl_ctrl_groups);
Thomas Graf482a8522005-11-10 02:25:56 +01001084 if (err < 0)
Johannes Berg134e6372009-07-10 09:51:34 +00001085 goto problem;
Thomas Graf482a8522005-11-10 02:25:56 +01001086
Johannes Berg134e6372009-07-10 09:51:34 +00001087 err = register_pernet_subsys(&genl_pernet_ops);
1088 if (err)
1089 goto problem;
Thomas Graf482a8522005-11-10 02:25:56 +01001090
1091 return 0;
1092
Johannes Berg134e6372009-07-10 09:51:34 +00001093problem:
Thomas Graf482a8522005-11-10 02:25:56 +01001094 panic("GENL: Cannot register controller: %d\n", err);
Thomas Graf482a8522005-11-10 02:25:56 +01001095}
1096
1097subsys_initcall(genl_init);
1098
Eric W. Biederman15e47302012-09-07 20:12:54 +00001099static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
Johannes Berg134e6372009-07-10 09:51:34 +00001100 gfp_t flags)
1101{
1102 struct sk_buff *tmp;
1103 struct net *net, *prev = NULL;
1104 int err;
1105
1106 for_each_net_rcu(net) {
1107 if (prev) {
1108 tmp = skb_clone(skb, flags);
1109 if (!tmp) {
1110 err = -ENOMEM;
1111 goto error;
1112 }
1113 err = nlmsg_multicast(prev->genl_sock, tmp,
Eric W. Biederman15e47302012-09-07 20:12:54 +00001114 portid, group, flags);
Johannes Berg134e6372009-07-10 09:51:34 +00001115 if (err)
1116 goto error;
1117 }
1118
1119 prev = net;
1120 }
1121
Eric W. Biederman15e47302012-09-07 20:12:54 +00001122 return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
Johannes Berg134e6372009-07-10 09:51:34 +00001123 error:
1124 kfree_skb(skb);
1125 return err;
1126}
1127
Johannes Berg68eb5502013-11-19 15:19:38 +01001128int genlmsg_multicast_allns(struct genl_family *family, struct sk_buff *skb,
1129 u32 portid, unsigned int group, gfp_t flags)
Johannes Berg134e6372009-07-10 09:51:34 +00001130{
Johannes Berg220815a2013-11-21 18:17:04 +01001131 if (WARN_ON_ONCE(group >= family->n_mcgrps))
Johannes Berg2a94fe42013-11-19 15:19:39 +01001132 return -EINVAL;
1133 group = family->mcgrp_offset + group;
Eric W. Biederman15e47302012-09-07 20:12:54 +00001134 return genlmsg_mcast(skb, portid, group, flags);
Johannes Berg134e6372009-07-10 09:51:34 +00001135}
1136EXPORT_SYMBOL(genlmsg_multicast_allns);
Pravin B Shelar263ba612011-11-10 19:14:37 -08001137
Jiri Benc92c14d92015-09-22 18:56:43 +02001138void genl_notify(struct genl_family *family, struct sk_buff *skb,
1139 struct genl_info *info, u32 group, gfp_t flags)
Pravin B Shelar263ba612011-11-10 19:14:37 -08001140{
Jiri Benc92c14d92015-09-22 18:56:43 +02001141 struct net *net = genl_info_net(info);
Pravin B Shelar263ba612011-11-10 19:14:37 -08001142 struct sock *sk = net->genl_sock;
1143 int report = 0;
1144
Jiri Benc92c14d92015-09-22 18:56:43 +02001145 if (info->nlhdr)
1146 report = nlmsg_report(info->nlhdr);
Pravin B Shelar263ba612011-11-10 19:14:37 -08001147
Johannes Berg220815a2013-11-21 18:17:04 +01001148 if (WARN_ON_ONCE(group >= family->n_mcgrps))
Johannes Berg2a94fe42013-11-19 15:19:39 +01001149 return;
1150 group = family->mcgrp_offset + group;
Jiri Benc92c14d92015-09-22 18:56:43 +02001151 nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
Pravin B Shelar263ba612011-11-10 19:14:37 -08001152}
1153EXPORT_SYMBOL(genl_notify);