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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
113aa838 | 4 | * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> |
1da177e4 LT |
5 | * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
746fac4d | 11 | * |
1da177e4 LT |
12 | * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith |
13 | * added netlink_proto_exit | |
14 | * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> | |
15 | * use nlk_sk, as sk->protinfo is on a diet 8) | |
4fdb3bb7 HW |
16 | * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> |
17 | * - inc module use count of module that owns | |
18 | * the kernel socket in case userspace opens | |
19 | * socket of same protocol | |
20 | * - remove all module support, since netlink is | |
21 | * mandatory if CONFIG_NET=y these days | |
1da177e4 LT |
22 | */ |
23 | ||
1da177e4 LT |
24 | #include <linux/module.h> |
25 | ||
4fc268d2 | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/kernel.h> |
28 | #include <linux/init.h> | |
1da177e4 LT |
29 | #include <linux/signal.h> |
30 | #include <linux/sched.h> | |
31 | #include <linux/errno.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/stat.h> | |
34 | #include <linux/socket.h> | |
35 | #include <linux/un.h> | |
36 | #include <linux/fcntl.h> | |
37 | #include <linux/termios.h> | |
38 | #include <linux/sockios.h> | |
39 | #include <linux/net.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/slab.h> | |
42 | #include <asm/uaccess.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/netdevice.h> | |
45 | #include <linux/rtnetlink.h> | |
46 | #include <linux/proc_fs.h> | |
47 | #include <linux/seq_file.h> | |
1da177e4 LT |
48 | #include <linux/notifier.h> |
49 | #include <linux/security.h> | |
50 | #include <linux/jhash.h> | |
51 | #include <linux/jiffies.h> | |
52 | #include <linux/random.h> | |
53 | #include <linux/bitops.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/types.h> | |
54e0f520 | 56 | #include <linux/audit.h> |
af65bdfc | 57 | #include <linux/mutex.h> |
54e0f520 | 58 | |
457c4cbc | 59 | #include <net/net_namespace.h> |
1da177e4 LT |
60 | #include <net/sock.h> |
61 | #include <net/scm.h> | |
82ace47a | 62 | #include <net/netlink.h> |
1da177e4 | 63 | |
f7fa9b10 | 64 | #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) |
b4ff4f04 | 65 | #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) |
1da177e4 LT |
66 | |
67 | struct netlink_sock { | |
68 | /* struct sock has to be the first member of netlink_sock */ | |
69 | struct sock sk; | |
70 | u32 pid; | |
1da177e4 | 71 | u32 dst_pid; |
d629b836 | 72 | u32 dst_group; |
f7fa9b10 PM |
73 | u32 flags; |
74 | u32 subscriptions; | |
75 | u32 ngroups; | |
76 | unsigned long *groups; | |
1da177e4 LT |
77 | unsigned long state; |
78 | wait_queue_head_t wait; | |
79 | struct netlink_callback *cb; | |
af65bdfc PM |
80 | struct mutex *cb_mutex; |
81 | struct mutex cb_def_mutex; | |
cd40b7d3 | 82 | void (*netlink_rcv)(struct sk_buff *skb); |
77247bbb | 83 | struct module *module; |
1da177e4 LT |
84 | }; |
85 | ||
5c398dc8 ED |
86 | struct listeners { |
87 | struct rcu_head rcu; | |
88 | unsigned long masks[0]; | |
6c04bb18 JB |
89 | }; |
90 | ||
77247bbb | 91 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 92 | #define NETLINK_RECV_PKTINFO 0x2 |
be0c22a4 | 93 | #define NETLINK_BROADCAST_SEND_ERROR 0x4 |
38938bfe | 94 | #define NETLINK_RECV_NO_ENOBUFS 0x8 |
77247bbb | 95 | |
1da177e4 LT |
96 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
97 | { | |
32b21e03 | 98 | return container_of(sk, struct netlink_sock, sk); |
1da177e4 LT |
99 | } |
100 | ||
035c4c16 | 101 | static inline int netlink_is_kernel(struct sock *sk) |
aed81560 DL |
102 | { |
103 | return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; | |
104 | } | |
105 | ||
1da177e4 LT |
106 | struct nl_pid_hash { |
107 | struct hlist_head *table; | |
108 | unsigned long rehash_time; | |
109 | ||
110 | unsigned int mask; | |
111 | unsigned int shift; | |
112 | ||
113 | unsigned int entries; | |
114 | unsigned int max_shift; | |
115 | ||
116 | u32 rnd; | |
117 | }; | |
118 | ||
119 | struct netlink_table { | |
120 | struct nl_pid_hash hash; | |
121 | struct hlist_head mc_list; | |
5c398dc8 | 122 | struct listeners __rcu *listeners; |
1da177e4 | 123 | unsigned int nl_nonroot; |
f7fa9b10 | 124 | unsigned int groups; |
af65bdfc | 125 | struct mutex *cb_mutex; |
77247bbb | 126 | struct module *module; |
ab33a171 | 127 | int registered; |
1da177e4 LT |
128 | }; |
129 | ||
130 | static struct netlink_table *nl_table; | |
131 | ||
132 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
133 | ||
134 | static int netlink_dump(struct sock *sk); | |
135 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
136 | ||
137 | static DEFINE_RWLOCK(nl_table_lock); | |
138 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
139 | ||
e041c683 | 140 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 141 | |
b57ef81f | 142 | static inline u32 netlink_group_mask(u32 group) |
d629b836 PM |
143 | { |
144 | return group ? 1 << (group - 1) : 0; | |
145 | } | |
146 | ||
b57ef81f | 147 | static inline struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
1da177e4 LT |
148 | { |
149 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
150 | } | |
151 | ||
152 | static void netlink_sock_destruct(struct sock *sk) | |
153 | { | |
3f660d66 HX |
154 | struct netlink_sock *nlk = nlk_sk(sk); |
155 | ||
3f660d66 HX |
156 | if (nlk->cb) { |
157 | if (nlk->cb->done) | |
158 | nlk->cb->done(nlk->cb); | |
159 | netlink_destroy_callback(nlk->cb); | |
160 | } | |
161 | ||
1da177e4 LT |
162 | skb_queue_purge(&sk->sk_receive_queue); |
163 | ||
164 | if (!sock_flag(sk, SOCK_DEAD)) { | |
6ac552fd | 165 | printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); |
1da177e4 LT |
166 | return; |
167 | } | |
547b792c IJ |
168 | |
169 | WARN_ON(atomic_read(&sk->sk_rmem_alloc)); | |
170 | WARN_ON(atomic_read(&sk->sk_wmem_alloc)); | |
171 | WARN_ON(nlk_sk(sk)->groups); | |
1da177e4 LT |
172 | } |
173 | ||
6ac552fd PM |
174 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on |
175 | * SMP. Look, when several writers sleep and reader wakes them up, all but one | |
1da177e4 LT |
176 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves |
177 | * this, _but_ remember, it adds useless work on UP machines. | |
178 | */ | |
179 | ||
d136f1bd | 180 | void netlink_table_grab(void) |
9a429c49 | 181 | __acquires(nl_table_lock) |
1da177e4 | 182 | { |
d136f1bd JB |
183 | might_sleep(); |
184 | ||
6abd219c | 185 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
186 | |
187 | if (atomic_read(&nl_table_users)) { | |
188 | DECLARE_WAITQUEUE(wait, current); | |
189 | ||
190 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 191 | for (;;) { |
1da177e4 LT |
192 | set_current_state(TASK_UNINTERRUPTIBLE); |
193 | if (atomic_read(&nl_table_users) == 0) | |
194 | break; | |
6abd219c | 195 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 196 | schedule(); |
6abd219c | 197 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
198 | } |
199 | ||
200 | __set_current_state(TASK_RUNNING); | |
201 | remove_wait_queue(&nl_table_wait, &wait); | |
202 | } | |
203 | } | |
204 | ||
d136f1bd | 205 | void netlink_table_ungrab(void) |
9a429c49 | 206 | __releases(nl_table_lock) |
1da177e4 | 207 | { |
6abd219c | 208 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
209 | wake_up(&nl_table_wait); |
210 | } | |
211 | ||
6ac552fd | 212 | static inline void |
1da177e4 LT |
213 | netlink_lock_table(void) |
214 | { | |
215 | /* read_lock() synchronizes us to netlink_table_grab */ | |
216 | ||
217 | read_lock(&nl_table_lock); | |
218 | atomic_inc(&nl_table_users); | |
219 | read_unlock(&nl_table_lock); | |
220 | } | |
221 | ||
6ac552fd | 222 | static inline void |
1da177e4 LT |
223 | netlink_unlock_table(void) |
224 | { | |
225 | if (atomic_dec_and_test(&nl_table_users)) | |
226 | wake_up(&nl_table_wait); | |
227 | } | |
228 | ||
b57ef81f | 229 | static struct sock *netlink_lookup(struct net *net, int protocol, u32 pid) |
1da177e4 LT |
230 | { |
231 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
232 | struct hlist_head *head; | |
233 | struct sock *sk; | |
234 | struct hlist_node *node; | |
235 | ||
236 | read_lock(&nl_table_lock); | |
237 | head = nl_pid_hashfn(hash, pid); | |
238 | sk_for_each(sk, node, head) { | |
878628fb | 239 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
240 | sock_hold(sk); |
241 | goto found; | |
242 | } | |
243 | } | |
244 | sk = NULL; | |
245 | found: | |
246 | read_unlock(&nl_table_lock); | |
247 | return sk; | |
248 | } | |
249 | ||
b57ef81f | 250 | static struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
251 | { |
252 | if (size <= PAGE_SIZE) | |
ea72912c | 253 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
254 | else |
255 | return (struct hlist_head *) | |
ea72912c ED |
256 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
257 | get_order(size)); | |
1da177e4 LT |
258 | } |
259 | ||
b57ef81f | 260 | static void nl_pid_hash_free(struct hlist_head *table, size_t size) |
1da177e4 LT |
261 | { |
262 | if (size <= PAGE_SIZE) | |
263 | kfree(table); | |
264 | else | |
265 | free_pages((unsigned long)table, get_order(size)); | |
266 | } | |
267 | ||
268 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
269 | { | |
270 | unsigned int omask, mask, shift; | |
271 | size_t osize, size; | |
272 | struct hlist_head *otable, *table; | |
273 | int i; | |
274 | ||
275 | omask = mask = hash->mask; | |
276 | osize = size = (mask + 1) * sizeof(*table); | |
277 | shift = hash->shift; | |
278 | ||
279 | if (grow) { | |
280 | if (++shift > hash->max_shift) | |
281 | return 0; | |
282 | mask = mask * 2 + 1; | |
283 | size *= 2; | |
284 | } | |
285 | ||
ea72912c | 286 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
287 | if (!table) |
288 | return 0; | |
289 | ||
1da177e4 LT |
290 | otable = hash->table; |
291 | hash->table = table; | |
292 | hash->mask = mask; | |
293 | hash->shift = shift; | |
294 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
295 | ||
296 | for (i = 0; i <= omask; i++) { | |
297 | struct sock *sk; | |
298 | struct hlist_node *node, *tmp; | |
299 | ||
300 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
301 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
302 | } | |
303 | ||
304 | nl_pid_hash_free(otable, osize); | |
305 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
306 | return 1; | |
307 | } | |
308 | ||
309 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
310 | { | |
311 | int avg = hash->entries >> hash->shift; | |
312 | ||
313 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
314 | return 1; | |
315 | ||
316 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
317 | nl_pid_hash_rehash(hash, 0); | |
318 | return 1; | |
319 | } | |
320 | ||
321 | return 0; | |
322 | } | |
323 | ||
90ddc4f0 | 324 | static const struct proto_ops netlink_ops; |
1da177e4 | 325 | |
4277a083 PM |
326 | static void |
327 | netlink_update_listeners(struct sock *sk) | |
328 | { | |
329 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
330 | struct hlist_node *node; | |
331 | unsigned long mask; | |
332 | unsigned int i; | |
333 | ||
b4ff4f04 | 334 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 335 | mask = 0; |
b4ff4f04 JB |
336 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
337 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
338 | mask |= nlk_sk(sk)->groups[i]; | |
339 | } | |
5c398dc8 | 340 | tbl->listeners->masks[i] = mask; |
4277a083 PM |
341 | } |
342 | /* this function is only called with the netlink table "grabbed", which | |
343 | * makes sure updates are visible before bind or setsockopt return. */ | |
344 | } | |
345 | ||
b4b51029 | 346 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
347 | { |
348 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
349 | struct hlist_head *head; | |
350 | int err = -EADDRINUSE; | |
351 | struct sock *osk; | |
352 | struct hlist_node *node; | |
353 | int len; | |
354 | ||
355 | netlink_table_grab(); | |
356 | head = nl_pid_hashfn(hash, pid); | |
357 | len = 0; | |
358 | sk_for_each(osk, node, head) { | |
878628fb | 359 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
360 | break; |
361 | len++; | |
362 | } | |
363 | if (node) | |
364 | goto err; | |
365 | ||
366 | err = -EBUSY; | |
367 | if (nlk_sk(sk)->pid) | |
368 | goto err; | |
369 | ||
370 | err = -ENOMEM; | |
371 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
372 | goto err; | |
373 | ||
374 | if (len && nl_pid_hash_dilute(hash, len)) | |
375 | head = nl_pid_hashfn(hash, pid); | |
376 | hash->entries++; | |
377 | nlk_sk(sk)->pid = pid; | |
378 | sk_add_node(sk, head); | |
379 | err = 0; | |
380 | ||
381 | err: | |
382 | netlink_table_ungrab(); | |
383 | return err; | |
384 | } | |
385 | ||
386 | static void netlink_remove(struct sock *sk) | |
387 | { | |
388 | netlink_table_grab(); | |
d470e3b4 DM |
389 | if (sk_del_node_init(sk)) |
390 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 391 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
392 | __sk_del_bind_node(sk); |
393 | netlink_table_ungrab(); | |
394 | } | |
395 | ||
396 | static struct proto netlink_proto = { | |
397 | .name = "NETLINK", | |
398 | .owner = THIS_MODULE, | |
399 | .obj_size = sizeof(struct netlink_sock), | |
400 | }; | |
401 | ||
1b8d7ae4 EB |
402 | static int __netlink_create(struct net *net, struct socket *sock, |
403 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
404 | { |
405 | struct sock *sk; | |
406 | struct netlink_sock *nlk; | |
ab33a171 PM |
407 | |
408 | sock->ops = &netlink_ops; | |
409 | ||
6257ff21 | 410 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
411 | if (!sk) |
412 | return -ENOMEM; | |
413 | ||
414 | sock_init_data(sock, sk); | |
415 | ||
416 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
417 | if (cb_mutex) |
418 | nlk->cb_mutex = cb_mutex; | |
419 | else { | |
420 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
421 | mutex_init(nlk->cb_mutex); | |
422 | } | |
ab33a171 PM |
423 | init_waitqueue_head(&nlk->wait); |
424 | ||
425 | sk->sk_destruct = netlink_sock_destruct; | |
426 | sk->sk_protocol = protocol; | |
427 | return 0; | |
428 | } | |
429 | ||
3f378b68 EP |
430 | static int netlink_create(struct net *net, struct socket *sock, int protocol, |
431 | int kern) | |
ab33a171 PM |
432 | { |
433 | struct module *module = NULL; | |
af65bdfc | 434 | struct mutex *cb_mutex; |
f7fa9b10 | 435 | struct netlink_sock *nlk; |
ab33a171 | 436 | int err = 0; |
1da177e4 LT |
437 | |
438 | sock->state = SS_UNCONNECTED; | |
439 | ||
440 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
441 | return -ESOCKTNOSUPPORT; | |
442 | ||
6ac552fd | 443 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
444 | return -EPROTONOSUPPORT; |
445 | ||
77247bbb | 446 | netlink_lock_table(); |
95a5afca | 447 | #ifdef CONFIG_MODULES |
ab33a171 | 448 | if (!nl_table[protocol].registered) { |
77247bbb | 449 | netlink_unlock_table(); |
4fdb3bb7 | 450 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 451 | netlink_lock_table(); |
4fdb3bb7 | 452 | } |
ab33a171 PM |
453 | #endif |
454 | if (nl_table[protocol].registered && | |
455 | try_module_get(nl_table[protocol].module)) | |
456 | module = nl_table[protocol].module; | |
974c37e9 AD |
457 | else |
458 | err = -EPROTONOSUPPORT; | |
af65bdfc | 459 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 460 | netlink_unlock_table(); |
4fdb3bb7 | 461 | |
974c37e9 AD |
462 | if (err < 0) |
463 | goto out; | |
464 | ||
6ac552fd PM |
465 | err = __netlink_create(net, sock, cb_mutex, protocol); |
466 | if (err < 0) | |
f7fa9b10 PM |
467 | goto out_module; |
468 | ||
6f756a8c | 469 | local_bh_disable(); |
c1fd3b94 | 470 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
471 | local_bh_enable(); |
472 | ||
f7fa9b10 | 473 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 474 | nlk->module = module; |
ab33a171 PM |
475 | out: |
476 | return err; | |
1da177e4 | 477 | |
ab33a171 PM |
478 | out_module: |
479 | module_put(module); | |
480 | goto out; | |
1da177e4 LT |
481 | } |
482 | ||
483 | static int netlink_release(struct socket *sock) | |
484 | { | |
485 | struct sock *sk = sock->sk; | |
486 | struct netlink_sock *nlk; | |
487 | ||
488 | if (!sk) | |
489 | return 0; | |
490 | ||
491 | netlink_remove(sk); | |
ac57b3a9 | 492 | sock_orphan(sk); |
1da177e4 LT |
493 | nlk = nlk_sk(sk); |
494 | ||
3f660d66 HX |
495 | /* |
496 | * OK. Socket is unlinked, any packets that arrive now | |
497 | * will be purged. | |
498 | */ | |
1da177e4 | 499 | |
1da177e4 LT |
500 | sock->sk = NULL; |
501 | wake_up_interruptible_all(&nlk->wait); | |
502 | ||
503 | skb_queue_purge(&sk->sk_write_queue); | |
504 | ||
649300b9 | 505 | if (nlk->pid) { |
1da177e4 | 506 | struct netlink_notify n = { |
3b1e0a65 | 507 | .net = sock_net(sk), |
1da177e4 LT |
508 | .protocol = sk->sk_protocol, |
509 | .pid = nlk->pid, | |
510 | }; | |
e041c683 AS |
511 | atomic_notifier_call_chain(&netlink_chain, |
512 | NETLINK_URELEASE, &n); | |
746fac4d | 513 | } |
4fdb3bb7 | 514 | |
5e7c001c | 515 | module_put(nlk->module); |
4fdb3bb7 | 516 | |
4277a083 | 517 | netlink_table_grab(); |
aed81560 | 518 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
519 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
520 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
521 | kfree(nl_table[sk->sk_protocol].listeners); | |
522 | nl_table[sk->sk_protocol].module = NULL; | |
523 | nl_table[sk->sk_protocol].registered = 0; | |
524 | } | |
4277a083 PM |
525 | } else if (nlk->subscriptions) |
526 | netlink_update_listeners(sk); | |
527 | netlink_table_ungrab(); | |
77247bbb | 528 | |
f7fa9b10 PM |
529 | kfree(nlk->groups); |
530 | nlk->groups = NULL; | |
531 | ||
3755810c | 532 | local_bh_disable(); |
c1fd3b94 | 533 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 534 | local_bh_enable(); |
1da177e4 LT |
535 | sock_put(sk); |
536 | return 0; | |
537 | } | |
538 | ||
539 | static int netlink_autobind(struct socket *sock) | |
540 | { | |
541 | struct sock *sk = sock->sk; | |
3b1e0a65 | 542 | struct net *net = sock_net(sk); |
1da177e4 LT |
543 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
544 | struct hlist_head *head; | |
545 | struct sock *osk; | |
546 | struct hlist_node *node; | |
66aa4a55 | 547 | s32 pid = task_tgid_vnr(current); |
1da177e4 LT |
548 | int err; |
549 | static s32 rover = -4097; | |
550 | ||
551 | retry: | |
552 | cond_resched(); | |
553 | netlink_table_grab(); | |
554 | head = nl_pid_hashfn(hash, pid); | |
555 | sk_for_each(osk, node, head) { | |
878628fb | 556 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 557 | continue; |
1da177e4 LT |
558 | if (nlk_sk(osk)->pid == pid) { |
559 | /* Bind collision, search negative pid values. */ | |
560 | pid = rover--; | |
561 | if (rover > -4097) | |
562 | rover = -4097; | |
563 | netlink_table_ungrab(); | |
564 | goto retry; | |
565 | } | |
566 | } | |
567 | netlink_table_ungrab(); | |
568 | ||
b4b51029 | 569 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
570 | if (err == -EADDRINUSE) |
571 | goto retry; | |
d470e3b4 DM |
572 | |
573 | /* If 2 threads race to autobind, that is fine. */ | |
574 | if (err == -EBUSY) | |
575 | err = 0; | |
576 | ||
577 | return err; | |
1da177e4 LT |
578 | } |
579 | ||
b57ef81f | 580 | static inline int netlink_capable(const struct socket *sock, unsigned int flag) |
746fac4d | 581 | { |
1da177e4 LT |
582 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
583 | capable(CAP_NET_ADMIN); | |
746fac4d | 584 | } |
1da177e4 | 585 | |
f7fa9b10 PM |
586 | static void |
587 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
588 | { | |
589 | struct netlink_sock *nlk = nlk_sk(sk); | |
590 | ||
591 | if (nlk->subscriptions && !subscriptions) | |
592 | __sk_del_bind_node(sk); | |
593 | else if (!nlk->subscriptions && subscriptions) | |
594 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
595 | nlk->subscriptions = subscriptions; | |
596 | } | |
597 | ||
b4ff4f04 | 598 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
599 | { |
600 | struct netlink_sock *nlk = nlk_sk(sk); | |
601 | unsigned int groups; | |
b4ff4f04 | 602 | unsigned long *new_groups; |
513c2500 PM |
603 | int err = 0; |
604 | ||
b4ff4f04 JB |
605 | netlink_table_grab(); |
606 | ||
513c2500 | 607 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 608 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 609 | err = -ENOENT; |
b4ff4f04 JB |
610 | goto out_unlock; |
611 | } | |
513c2500 | 612 | |
b4ff4f04 JB |
613 | if (nlk->ngroups >= groups) |
614 | goto out_unlock; | |
513c2500 | 615 | |
b4ff4f04 JB |
616 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
617 | if (new_groups == NULL) { | |
618 | err = -ENOMEM; | |
619 | goto out_unlock; | |
620 | } | |
6ac552fd | 621 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
622 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
623 | ||
624 | nlk->groups = new_groups; | |
513c2500 | 625 | nlk->ngroups = groups; |
b4ff4f04 JB |
626 | out_unlock: |
627 | netlink_table_ungrab(); | |
628 | return err; | |
513c2500 PM |
629 | } |
630 | ||
6ac552fd PM |
631 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
632 | int addr_len) | |
1da177e4 LT |
633 | { |
634 | struct sock *sk = sock->sk; | |
3b1e0a65 | 635 | struct net *net = sock_net(sk); |
1da177e4 LT |
636 | struct netlink_sock *nlk = nlk_sk(sk); |
637 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
638 | int err; | |
746fac4d | 639 | |
1da177e4 LT |
640 | if (nladdr->nl_family != AF_NETLINK) |
641 | return -EINVAL; | |
642 | ||
643 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
644 | if (nladdr->nl_groups) { |
645 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
646 | return -EPERM; | |
b4ff4f04 JB |
647 | err = netlink_realloc_groups(sk); |
648 | if (err) | |
649 | return err; | |
513c2500 | 650 | } |
1da177e4 LT |
651 | |
652 | if (nlk->pid) { | |
653 | if (nladdr->nl_pid != nlk->pid) | |
654 | return -EINVAL; | |
655 | } else { | |
656 | err = nladdr->nl_pid ? | |
b4b51029 | 657 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
658 | netlink_autobind(sock); |
659 | if (err) | |
660 | return err; | |
661 | } | |
662 | ||
513c2500 | 663 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
664 | return 0; |
665 | ||
666 | netlink_table_grab(); | |
f7fa9b10 | 667 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
668 | hweight32(nladdr->nl_groups) - |
669 | hweight32(nlk->groups[0])); | |
670 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 671 | netlink_update_listeners(sk); |
1da177e4 LT |
672 | netlink_table_ungrab(); |
673 | ||
674 | return 0; | |
675 | } | |
676 | ||
677 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
678 | int alen, int flags) | |
679 | { | |
680 | int err = 0; | |
681 | struct sock *sk = sock->sk; | |
682 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 683 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 | 684 | |
6503d961 CG |
685 | if (alen < sizeof(addr->sa_family)) |
686 | return -EINVAL; | |
687 | ||
1da177e4 LT |
688 | if (addr->sa_family == AF_UNSPEC) { |
689 | sk->sk_state = NETLINK_UNCONNECTED; | |
690 | nlk->dst_pid = 0; | |
d629b836 | 691 | nlk->dst_group = 0; |
1da177e4 LT |
692 | return 0; |
693 | } | |
694 | if (addr->sa_family != AF_NETLINK) | |
695 | return -EINVAL; | |
696 | ||
697 | /* Only superuser is allowed to send multicasts */ | |
698 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
699 | return -EPERM; | |
700 | ||
701 | if (!nlk->pid) | |
702 | err = netlink_autobind(sock); | |
703 | ||
704 | if (err == 0) { | |
705 | sk->sk_state = NETLINK_CONNECTED; | |
706 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 707 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
708 | } |
709 | ||
710 | return err; | |
711 | } | |
712 | ||
6ac552fd PM |
713 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
714 | int *addr_len, int peer) | |
1da177e4 LT |
715 | { |
716 | struct sock *sk = sock->sk; | |
717 | struct netlink_sock *nlk = nlk_sk(sk); | |
13cfa97b | 718 | DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); |
746fac4d | 719 | |
1da177e4 LT |
720 | nladdr->nl_family = AF_NETLINK; |
721 | nladdr->nl_pad = 0; | |
722 | *addr_len = sizeof(*nladdr); | |
723 | ||
724 | if (peer) { | |
725 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 726 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
727 | } else { |
728 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 729 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
730 | } |
731 | return 0; | |
732 | } | |
733 | ||
734 | static void netlink_overrun(struct sock *sk) | |
735 | { | |
38938bfe PNA |
736 | struct netlink_sock *nlk = nlk_sk(sk); |
737 | ||
738 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
739 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
740 | sk->sk_err = ENOBUFS; | |
741 | sk->sk_error_report(sk); | |
742 | } | |
1da177e4 | 743 | } |
38938bfe | 744 | atomic_inc(&sk->sk_drops); |
1da177e4 LT |
745 | } |
746 | ||
747 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
748 | { | |
1da177e4 LT |
749 | struct sock *sock; |
750 | struct netlink_sock *nlk; | |
751 | ||
3b1e0a65 | 752 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); |
1da177e4 LT |
753 | if (!sock) |
754 | return ERR_PTR(-ECONNREFUSED); | |
755 | ||
756 | /* Don't bother queuing skb if kernel socket has no input function */ | |
757 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
758 | if (sock->sk_state == NETLINK_CONNECTED && |
759 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
760 | sock_put(sock); |
761 | return ERR_PTR(-ECONNREFUSED); | |
762 | } | |
763 | return sock; | |
764 | } | |
765 | ||
766 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
767 | { | |
6db5fc5d | 768 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
769 | struct sock *sock; |
770 | ||
771 | if (!S_ISSOCK(inode->i_mode)) | |
772 | return ERR_PTR(-ENOTSOCK); | |
773 | ||
774 | sock = SOCKET_I(inode)->sk; | |
775 | if (sock->sk_family != AF_NETLINK) | |
776 | return ERR_PTR(-EINVAL); | |
777 | ||
778 | sock_hold(sock); | |
779 | return sock; | |
780 | } | |
781 | ||
782 | /* | |
783 | * Attach a skb to a netlink socket. | |
784 | * The caller must hold a reference to the destination socket. On error, the | |
785 | * reference is dropped. The skb is not send to the destination, just all | |
786 | * all error checks are performed and memory in the queue is reserved. | |
787 | * Return values: | |
788 | * < 0: error. skb freed, reference to sock dropped. | |
789 | * 0: continue | |
790 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
791 | */ | |
9457afee | 792 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 793 | long *timeo, struct sock *ssk) |
1da177e4 LT |
794 | { |
795 | struct netlink_sock *nlk; | |
796 | ||
797 | nlk = nlk_sk(sk); | |
798 | ||
799 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
800 | test_bit(0, &nlk->state)) { | |
801 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 802 | if (!*timeo) { |
aed81560 | 803 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
804 | netlink_overrun(sk); |
805 | sock_put(sk); | |
806 | kfree_skb(skb); | |
807 | return -EAGAIN; | |
808 | } | |
809 | ||
810 | __set_current_state(TASK_INTERRUPTIBLE); | |
811 | add_wait_queue(&nlk->wait, &wait); | |
812 | ||
813 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
814 | test_bit(0, &nlk->state)) && | |
815 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 816 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
817 | |
818 | __set_current_state(TASK_RUNNING); | |
819 | remove_wait_queue(&nlk->wait, &wait); | |
820 | sock_put(sk); | |
821 | ||
822 | if (signal_pending(current)) { | |
823 | kfree_skb(skb); | |
c3d8d1e3 | 824 | return sock_intr_errno(*timeo); |
1da177e4 LT |
825 | } |
826 | return 1; | |
827 | } | |
828 | skb_set_owner_r(skb, sk); | |
829 | return 0; | |
830 | } | |
831 | ||
4a7e7c2a | 832 | static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 833 | { |
1da177e4 LT |
834 | int len = skb->len; |
835 | ||
1da177e4 LT |
836 | skb_queue_tail(&sk->sk_receive_queue, skb); |
837 | sk->sk_data_ready(sk, len); | |
4a7e7c2a ED |
838 | return len; |
839 | } | |
840 | ||
841 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) | |
842 | { | |
843 | int len = __netlink_sendskb(sk, skb); | |
844 | ||
1da177e4 LT |
845 | sock_put(sk); |
846 | return len; | |
847 | } | |
848 | ||
849 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
850 | { | |
851 | kfree_skb(skb); | |
852 | sock_put(sk); | |
853 | } | |
854 | ||
b57ef81f | 855 | static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) |
1da177e4 LT |
856 | { |
857 | int delta; | |
858 | ||
859 | skb_orphan(skb); | |
860 | ||
4305b541 | 861 | delta = skb->end - skb->tail; |
1da177e4 LT |
862 | if (delta * 2 < skb->truesize) |
863 | return skb; | |
864 | ||
865 | if (skb_shared(skb)) { | |
866 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
867 | if (!nskb) | |
868 | return skb; | |
869 | kfree_skb(skb); | |
870 | skb = nskb; | |
871 | } | |
872 | ||
873 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
874 | skb->truesize -= delta; | |
875 | ||
876 | return skb; | |
877 | } | |
878 | ||
b57ef81f | 879 | static void netlink_rcv_wake(struct sock *sk) |
cd40b7d3 DL |
880 | { |
881 | struct netlink_sock *nlk = nlk_sk(sk); | |
882 | ||
883 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
884 | clear_bit(0, &nlk->state); | |
885 | if (!test_bit(0, &nlk->state)) | |
886 | wake_up_interruptible(&nlk->wait); | |
887 | } | |
888 | ||
b57ef81f | 889 | static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) |
cd40b7d3 DL |
890 | { |
891 | int ret; | |
892 | struct netlink_sock *nlk = nlk_sk(sk); | |
893 | ||
894 | ret = -ECONNREFUSED; | |
895 | if (nlk->netlink_rcv != NULL) { | |
896 | ret = skb->len; | |
897 | skb_set_owner_r(skb, sk); | |
898 | nlk->netlink_rcv(skb); | |
899 | } | |
900 | kfree_skb(skb); | |
901 | sock_put(sk); | |
902 | return ret; | |
903 | } | |
904 | ||
905 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
906 | u32 pid, int nonblock) | |
1da177e4 LT |
907 | { |
908 | struct sock *sk; | |
909 | int err; | |
910 | long timeo; | |
911 | ||
912 | skb = netlink_trim(skb, gfp_any()); | |
913 | ||
914 | timeo = sock_sndtimeo(ssk, nonblock); | |
915 | retry: | |
916 | sk = netlink_getsockbypid(ssk, pid); | |
917 | if (IS_ERR(sk)) { | |
918 | kfree_skb(skb); | |
919 | return PTR_ERR(sk); | |
920 | } | |
cd40b7d3 DL |
921 | if (netlink_is_kernel(sk)) |
922 | return netlink_unicast_kernel(sk, skb); | |
923 | ||
b1153f29 | 924 | if (sk_filter(sk, skb)) { |
84874607 | 925 | err = skb->len; |
b1153f29 SH |
926 | kfree_skb(skb); |
927 | sock_put(sk); | |
928 | return err; | |
929 | } | |
930 | ||
9457afee | 931 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
932 | if (err == 1) |
933 | goto retry; | |
934 | if (err) | |
935 | return err; | |
936 | ||
7ee015e0 | 937 | return netlink_sendskb(sk, skb); |
1da177e4 | 938 | } |
6ac552fd | 939 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 940 | |
4277a083 PM |
941 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
942 | { | |
943 | int res = 0; | |
5c398dc8 | 944 | struct listeners *listeners; |
4277a083 | 945 | |
aed81560 | 946 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
947 | |
948 | rcu_read_lock(); | |
949 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
950 | ||
4277a083 | 951 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
5c398dc8 | 952 | res = test_bit(group - 1, listeners->masks); |
b4ff4f04 JB |
953 | |
954 | rcu_read_unlock(); | |
955 | ||
4277a083 PM |
956 | return res; |
957 | } | |
958 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
959 | ||
b57ef81f | 960 | static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
961 | { |
962 | struct netlink_sock *nlk = nlk_sk(sk); | |
963 | ||
964 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
965 | !test_bit(0, &nlk->state)) { | |
966 | skb_set_owner_r(skb, sk); | |
4a7e7c2a | 967 | __netlink_sendskb(sk, skb); |
2c645800 | 968 | return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); |
1da177e4 LT |
969 | } |
970 | return -1; | |
971 | } | |
972 | ||
973 | struct netlink_broadcast_data { | |
974 | struct sock *exclude_sk; | |
b4b51029 | 975 | struct net *net; |
1da177e4 LT |
976 | u32 pid; |
977 | u32 group; | |
978 | int failure; | |
ff491a73 | 979 | int delivery_failure; |
1da177e4 LT |
980 | int congested; |
981 | int delivered; | |
7d877f3b | 982 | gfp_t allocation; |
1da177e4 | 983 | struct sk_buff *skb, *skb2; |
910a7e90 EB |
984 | int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); |
985 | void *tx_data; | |
1da177e4 LT |
986 | }; |
987 | ||
b57ef81f | 988 | static int do_one_broadcast(struct sock *sk, |
1da177e4 LT |
989 | struct netlink_broadcast_data *p) |
990 | { | |
991 | struct netlink_sock *nlk = nlk_sk(sk); | |
992 | int val; | |
993 | ||
994 | if (p->exclude_sk == sk) | |
995 | goto out; | |
996 | ||
f7fa9b10 PM |
997 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
998 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
999 | goto out; |
1000 | ||
878628fb | 1001 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
1002 | goto out; |
1003 | ||
1da177e4 LT |
1004 | if (p->failure) { |
1005 | netlink_overrun(sk); | |
1006 | goto out; | |
1007 | } | |
1008 | ||
1009 | sock_hold(sk); | |
1010 | if (p->skb2 == NULL) { | |
68acc024 | 1011 | if (skb_shared(p->skb)) { |
1da177e4 LT |
1012 | p->skb2 = skb_clone(p->skb, p->allocation); |
1013 | } else { | |
68acc024 TC |
1014 | p->skb2 = skb_get(p->skb); |
1015 | /* | |
1016 | * skb ownership may have been set when | |
1017 | * delivered to a previous socket. | |
1018 | */ | |
1019 | skb_orphan(p->skb2); | |
1da177e4 LT |
1020 | } |
1021 | } | |
1022 | if (p->skb2 == NULL) { | |
1023 | netlink_overrun(sk); | |
1024 | /* Clone failed. Notify ALL listeners. */ | |
1025 | p->failure = 1; | |
be0c22a4 PNA |
1026 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1027 | p->delivery_failure = 1; | |
910a7e90 EB |
1028 | } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { |
1029 | kfree_skb(p->skb2); | |
1030 | p->skb2 = NULL; | |
b1153f29 SH |
1031 | } else if (sk_filter(sk, p->skb2)) { |
1032 | kfree_skb(p->skb2); | |
1033 | p->skb2 = NULL; | |
1da177e4 LT |
1034 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1035 | netlink_overrun(sk); | |
be0c22a4 PNA |
1036 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1037 | p->delivery_failure = 1; | |
1da177e4 LT |
1038 | } else { |
1039 | p->congested |= val; | |
1040 | p->delivered = 1; | |
1041 | p->skb2 = NULL; | |
1042 | } | |
1043 | sock_put(sk); | |
1044 | ||
1045 | out: | |
1046 | return 0; | |
1047 | } | |
1048 | ||
910a7e90 EB |
1049 | int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid, |
1050 | u32 group, gfp_t allocation, | |
1051 | int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), | |
1052 | void *filter_data) | |
1da177e4 | 1053 | { |
3b1e0a65 | 1054 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1055 | struct netlink_broadcast_data info; |
1056 | struct hlist_node *node; | |
1057 | struct sock *sk; | |
1058 | ||
1059 | skb = netlink_trim(skb, allocation); | |
1060 | ||
1061 | info.exclude_sk = ssk; | |
b4b51029 | 1062 | info.net = net; |
1da177e4 LT |
1063 | info.pid = pid; |
1064 | info.group = group; | |
1065 | info.failure = 0; | |
ff491a73 | 1066 | info.delivery_failure = 0; |
1da177e4 LT |
1067 | info.congested = 0; |
1068 | info.delivered = 0; | |
1069 | info.allocation = allocation; | |
1070 | info.skb = skb; | |
1071 | info.skb2 = NULL; | |
910a7e90 EB |
1072 | info.tx_filter = filter; |
1073 | info.tx_data = filter_data; | |
1da177e4 LT |
1074 | |
1075 | /* While we sleep in clone, do not allow to change socket list */ | |
1076 | ||
1077 | netlink_lock_table(); | |
1078 | ||
1079 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1080 | do_one_broadcast(sk, &info); | |
1081 | ||
70d4bf6d | 1082 | consume_skb(skb); |
aa1c6a6f | 1083 | |
1da177e4 LT |
1084 | netlink_unlock_table(); |
1085 | ||
70d4bf6d NH |
1086 | if (info.delivery_failure) { |
1087 | kfree_skb(info.skb2); | |
ff491a73 | 1088 | return -ENOBUFS; |
70d4bf6d NH |
1089 | } else |
1090 | consume_skb(info.skb2); | |
ff491a73 | 1091 | |
1da177e4 LT |
1092 | if (info.delivered) { |
1093 | if (info.congested && (allocation & __GFP_WAIT)) | |
1094 | yield(); | |
1095 | return 0; | |
1096 | } | |
1da177e4 LT |
1097 | return -ESRCH; |
1098 | } | |
910a7e90 EB |
1099 | EXPORT_SYMBOL(netlink_broadcast_filtered); |
1100 | ||
1101 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
1102 | u32 group, gfp_t allocation) | |
1103 | { | |
1104 | return netlink_broadcast_filtered(ssk, skb, pid, group, allocation, | |
1105 | NULL, NULL); | |
1106 | } | |
6ac552fd | 1107 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1108 | |
1109 | struct netlink_set_err_data { | |
1110 | struct sock *exclude_sk; | |
1111 | u32 pid; | |
1112 | u32 group; | |
1113 | int code; | |
1114 | }; | |
1115 | ||
b57ef81f | 1116 | static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) |
1da177e4 LT |
1117 | { |
1118 | struct netlink_sock *nlk = nlk_sk(sk); | |
1a50307b | 1119 | int ret = 0; |
1da177e4 LT |
1120 | |
1121 | if (sk == p->exclude_sk) | |
1122 | goto out; | |
1123 | ||
09ad9bc7 | 1124 | if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) |
b4b51029 EB |
1125 | goto out; |
1126 | ||
f7fa9b10 PM |
1127 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1128 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1129 | goto out; |
1130 | ||
1a50307b PNA |
1131 | if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) { |
1132 | ret = 1; | |
1133 | goto out; | |
1134 | } | |
1135 | ||
1da177e4 LT |
1136 | sk->sk_err = p->code; |
1137 | sk->sk_error_report(sk); | |
1138 | out: | |
1a50307b | 1139 | return ret; |
1da177e4 LT |
1140 | } |
1141 | ||
4843b93c PNA |
1142 | /** |
1143 | * netlink_set_err - report error to broadcast listeners | |
1144 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
1145 | * @pid: the PID of a process that we want to skip (if any) | |
1146 | * @groups: the broadcast group that will notice the error | |
1147 | * @code: error code, must be negative (as usual in kernelspace) | |
1a50307b PNA |
1148 | * |
1149 | * This function returns the number of broadcast listeners that have set the | |
1150 | * NETLINK_RECV_NO_ENOBUFS socket option. | |
4843b93c | 1151 | */ |
1a50307b | 1152 | int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) |
1da177e4 LT |
1153 | { |
1154 | struct netlink_set_err_data info; | |
1155 | struct hlist_node *node; | |
1156 | struct sock *sk; | |
1a50307b | 1157 | int ret = 0; |
1da177e4 LT |
1158 | |
1159 | info.exclude_sk = ssk; | |
1160 | info.pid = pid; | |
1161 | info.group = group; | |
4843b93c PNA |
1162 | /* sk->sk_err wants a positive error value */ |
1163 | info.code = -code; | |
1da177e4 LT |
1164 | |
1165 | read_lock(&nl_table_lock); | |
1166 | ||
1167 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1a50307b | 1168 | ret += do_one_set_err(sk, &info); |
1da177e4 LT |
1169 | |
1170 | read_unlock(&nl_table_lock); | |
1a50307b | 1171 | return ret; |
1da177e4 | 1172 | } |
dd5b6ce6 | 1173 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1174 | |
84659eb5 JB |
1175 | /* must be called with netlink table grabbed */ |
1176 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1177 | unsigned int group, | |
1178 | int is_new) | |
1179 | { | |
1180 | int old, new = !!is_new, subscriptions; | |
1181 | ||
1182 | old = test_bit(group - 1, nlk->groups); | |
1183 | subscriptions = nlk->subscriptions - old + new; | |
1184 | if (new) | |
1185 | __set_bit(group - 1, nlk->groups); | |
1186 | else | |
1187 | __clear_bit(group - 1, nlk->groups); | |
1188 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1189 | netlink_update_listeners(&nlk->sk); | |
1190 | } | |
1191 | ||
9a4595bc | 1192 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
b7058842 | 1193 | char __user *optval, unsigned int optlen) |
9a4595bc PM |
1194 | { |
1195 | struct sock *sk = sock->sk; | |
1196 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1197 | unsigned int val = 0; |
1198 | int err; | |
9a4595bc PM |
1199 | |
1200 | if (level != SOL_NETLINK) | |
1201 | return -ENOPROTOOPT; | |
1202 | ||
1203 | if (optlen >= sizeof(int) && | |
eb496534 | 1204 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1205 | return -EFAULT; |
1206 | ||
1207 | switch (optname) { | |
1208 | case NETLINK_PKTINFO: | |
1209 | if (val) | |
1210 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1211 | else | |
1212 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1213 | err = 0; | |
1214 | break; | |
1215 | case NETLINK_ADD_MEMBERSHIP: | |
1216 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1217 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1218 | return -EPERM; | |
b4ff4f04 JB |
1219 | err = netlink_realloc_groups(sk); |
1220 | if (err) | |
1221 | return err; | |
9a4595bc PM |
1222 | if (!val || val - 1 >= nlk->ngroups) |
1223 | return -EINVAL; | |
1224 | netlink_table_grab(); | |
84659eb5 JB |
1225 | netlink_update_socket_mc(nlk, val, |
1226 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1227 | netlink_table_ungrab(); |
1228 | err = 0; | |
1229 | break; | |
1230 | } | |
be0c22a4 PNA |
1231 | case NETLINK_BROADCAST_ERROR: |
1232 | if (val) | |
1233 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1234 | else | |
1235 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1236 | err = 0; | |
1237 | break; | |
38938bfe PNA |
1238 | case NETLINK_NO_ENOBUFS: |
1239 | if (val) { | |
1240 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
1241 | clear_bit(0, &nlk->state); | |
1242 | wake_up_interruptible(&nlk->wait); | |
1243 | } else | |
1244 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; | |
1245 | err = 0; | |
1246 | break; | |
9a4595bc PM |
1247 | default: |
1248 | err = -ENOPROTOOPT; | |
1249 | } | |
1250 | return err; | |
1251 | } | |
1252 | ||
1253 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1254 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1255 | { |
1256 | struct sock *sk = sock->sk; | |
1257 | struct netlink_sock *nlk = nlk_sk(sk); | |
1258 | int len, val, err; | |
1259 | ||
1260 | if (level != SOL_NETLINK) | |
1261 | return -ENOPROTOOPT; | |
1262 | ||
1263 | if (get_user(len, optlen)) | |
1264 | return -EFAULT; | |
1265 | if (len < 0) | |
1266 | return -EINVAL; | |
1267 | ||
1268 | switch (optname) { | |
1269 | case NETLINK_PKTINFO: | |
1270 | if (len < sizeof(int)) | |
1271 | return -EINVAL; | |
1272 | len = sizeof(int); | |
1273 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1274 | if (put_user(len, optlen) || |
1275 | put_user(val, optval)) | |
1276 | return -EFAULT; | |
9a4595bc PM |
1277 | err = 0; |
1278 | break; | |
be0c22a4 PNA |
1279 | case NETLINK_BROADCAST_ERROR: |
1280 | if (len < sizeof(int)) | |
1281 | return -EINVAL; | |
1282 | len = sizeof(int); | |
1283 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1284 | if (put_user(len, optlen) || | |
1285 | put_user(val, optval)) | |
1286 | return -EFAULT; | |
1287 | err = 0; | |
1288 | break; | |
38938bfe PNA |
1289 | case NETLINK_NO_ENOBUFS: |
1290 | if (len < sizeof(int)) | |
1291 | return -EINVAL; | |
1292 | len = sizeof(int); | |
1293 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
1294 | if (put_user(len, optlen) || | |
1295 | put_user(val, optval)) | |
1296 | return -EFAULT; | |
1297 | err = 0; | |
1298 | break; | |
9a4595bc PM |
1299 | default: |
1300 | err = -ENOPROTOOPT; | |
1301 | } | |
1302 | return err; | |
1303 | } | |
1304 | ||
1305 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1306 | { | |
1307 | struct nl_pktinfo info; | |
1308 | ||
1309 | info.group = NETLINK_CB(skb).dst_group; | |
1310 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1311 | } | |
1312 | ||
1da177e4 LT |
1313 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1314 | struct msghdr *msg, size_t len) | |
1315 | { | |
1316 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1317 | struct sock *sk = sock->sk; | |
1318 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1319 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1320 | u32 dst_pid; |
d629b836 | 1321 | u32 dst_group; |
1da177e4 LT |
1322 | struct sk_buff *skb; |
1323 | int err; | |
1324 | struct scm_cookie scm; | |
1325 | ||
1326 | if (msg->msg_flags&MSG_OOB) | |
1327 | return -EOPNOTSUPP; | |
1328 | ||
16e57262 | 1329 | if (NULL == siocb->scm) |
1da177e4 | 1330 | siocb->scm = &scm; |
16e57262 | 1331 | |
1da177e4 LT |
1332 | err = scm_send(sock, msg, siocb->scm); |
1333 | if (err < 0) | |
1334 | return err; | |
1335 | ||
1336 | if (msg->msg_namelen) { | |
b47030c7 | 1337 | err = -EINVAL; |
1da177e4 | 1338 | if (addr->nl_family != AF_NETLINK) |
b47030c7 | 1339 | goto out; |
1da177e4 | 1340 | dst_pid = addr->nl_pid; |
d629b836 | 1341 | dst_group = ffs(addr->nl_groups); |
b47030c7 | 1342 | err = -EPERM; |
d629b836 | 1343 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) |
b47030c7 | 1344 | goto out; |
1da177e4 LT |
1345 | } else { |
1346 | dst_pid = nlk->dst_pid; | |
d629b836 | 1347 | dst_group = nlk->dst_group; |
1da177e4 LT |
1348 | } |
1349 | ||
1350 | if (!nlk->pid) { | |
1351 | err = netlink_autobind(sock); | |
1352 | if (err) | |
1353 | goto out; | |
1354 | } | |
1355 | ||
1356 | err = -EMSGSIZE; | |
1357 | if (len > sk->sk_sndbuf - 32) | |
1358 | goto out; | |
1359 | err = -ENOBUFS; | |
339bf98f | 1360 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1361 | if (skb == NULL) |
1da177e4 LT |
1362 | goto out; |
1363 | ||
1364 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1365 | NETLINK_CB(skb).dst_group = dst_group; |
1da177e4 LT |
1366 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1367 | ||
1da177e4 | 1368 | err = -EFAULT; |
6ac552fd | 1369 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1370 | kfree_skb(skb); |
1371 | goto out; | |
1372 | } | |
1373 | ||
1374 | err = security_netlink_send(sk, skb); | |
1375 | if (err) { | |
1376 | kfree_skb(skb); | |
1377 | goto out; | |
1378 | } | |
1379 | ||
d629b836 | 1380 | if (dst_group) { |
1da177e4 | 1381 | atomic_inc(&skb->users); |
d629b836 | 1382 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1383 | } |
1384 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1385 | ||
1386 | out: | |
b47030c7 | 1387 | scm_destroy(siocb->scm); |
1da177e4 LT |
1388 | return err; |
1389 | } | |
1390 | ||
1391 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1392 | struct msghdr *msg, size_t len, | |
1393 | int flags) | |
1394 | { | |
1395 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1396 | struct scm_cookie scm; | |
1397 | struct sock *sk = sock->sk; | |
1398 | struct netlink_sock *nlk = nlk_sk(sk); | |
1399 | int noblock = flags&MSG_DONTWAIT; | |
1400 | size_t copied; | |
68d6ac6d | 1401 | struct sk_buff *skb, *data_skb; |
b44d211e | 1402 | int err, ret; |
1da177e4 LT |
1403 | |
1404 | if (flags&MSG_OOB) | |
1405 | return -EOPNOTSUPP; | |
1406 | ||
1407 | copied = 0; | |
1408 | ||
6ac552fd PM |
1409 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1410 | if (skb == NULL) | |
1da177e4 LT |
1411 | goto out; |
1412 | ||
68d6ac6d JB |
1413 | data_skb = skb; |
1414 | ||
1dacc76d JB |
1415 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1416 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1dacc76d | 1417 | /* |
68d6ac6d JB |
1418 | * If this skb has a frag_list, then here that means that we |
1419 | * will have to use the frag_list skb's data for compat tasks | |
1420 | * and the regular skb's data for normal (non-compat) tasks. | |
1dacc76d | 1421 | * |
68d6ac6d JB |
1422 | * If we need to send the compat skb, assign it to the |
1423 | * 'data_skb' variable so that it will be used below for data | |
1424 | * copying. We keep 'skb' for everything else, including | |
1425 | * freeing both later. | |
1dacc76d | 1426 | */ |
68d6ac6d JB |
1427 | if (flags & MSG_CMSG_COMPAT) |
1428 | data_skb = skb_shinfo(skb)->frag_list; | |
1dacc76d JB |
1429 | } |
1430 | #endif | |
1431 | ||
1da177e4 LT |
1432 | msg->msg_namelen = 0; |
1433 | ||
68d6ac6d | 1434 | copied = data_skb->len; |
1da177e4 LT |
1435 | if (len < copied) { |
1436 | msg->msg_flags |= MSG_TRUNC; | |
1437 | copied = len; | |
1438 | } | |
1439 | ||
68d6ac6d JB |
1440 | skb_reset_transport_header(data_skb); |
1441 | err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied); | |
1da177e4 LT |
1442 | |
1443 | if (msg->msg_name) { | |
6ac552fd | 1444 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1445 | addr->nl_family = AF_NETLINK; |
1446 | addr->nl_pad = 0; | |
1447 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1448 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1449 | msg->msg_namelen = sizeof(*addr); |
1450 | } | |
1451 | ||
cc9a06cd PM |
1452 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1453 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1454 | ||
1da177e4 LT |
1455 | if (NULL == siocb->scm) { |
1456 | memset(&scm, 0, sizeof(scm)); | |
1457 | siocb->scm = &scm; | |
1458 | } | |
1459 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 | 1460 | if (flags & MSG_TRUNC) |
68d6ac6d | 1461 | copied = data_skb->len; |
daa3766e | 1462 | |
1da177e4 LT |
1463 | skb_free_datagram(sk, skb); |
1464 | ||
b44d211e AV |
1465 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { |
1466 | ret = netlink_dump(sk); | |
1467 | if (ret) { | |
1468 | sk->sk_err = ret; | |
1469 | sk->sk_error_report(sk); | |
1470 | } | |
1471 | } | |
1da177e4 LT |
1472 | |
1473 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1474 | out: |
1475 | netlink_rcv_wake(sk); | |
1476 | return err ? : copied; | |
1477 | } | |
1478 | ||
1479 | static void netlink_data_ready(struct sock *sk, int len) | |
1480 | { | |
cd40b7d3 | 1481 | BUG(); |
1da177e4 LT |
1482 | } |
1483 | ||
1484 | /* | |
746fac4d | 1485 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1486 | * complete set of kernel non-blocking support for message |
1487 | * queueing. | |
1488 | */ | |
1489 | ||
1490 | struct sock * | |
b4b51029 | 1491 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1492 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1493 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1494 | { |
1495 | struct socket *sock; | |
1496 | struct sock *sk; | |
77247bbb | 1497 | struct netlink_sock *nlk; |
5c398dc8 | 1498 | struct listeners *listeners = NULL; |
1da177e4 | 1499 | |
fab2caf6 | 1500 | BUG_ON(!nl_table); |
1da177e4 | 1501 | |
6ac552fd | 1502 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1503 | return NULL; |
1504 | ||
1505 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1506 | return NULL; | |
1507 | ||
23fe1866 PE |
1508 | /* |
1509 | * We have to just have a reference on the net from sk, but don't | |
1510 | * get_net it. Besides, we cannot get and then put the net here. | |
1511 | * So we create one inside init_net and the move it to net. | |
1512 | */ | |
1513 | ||
1514 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1515 | goto out_sock_release_nosk; | |
1516 | ||
1517 | sk = sock->sk; | |
edf02087 | 1518 | sk_change_net(sk, net); |
4fdb3bb7 | 1519 | |
4277a083 PM |
1520 | if (groups < 32) |
1521 | groups = 32; | |
1522 | ||
5c398dc8 | 1523 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
4277a083 PM |
1524 | if (!listeners) |
1525 | goto out_sock_release; | |
1526 | ||
1da177e4 LT |
1527 | sk->sk_data_ready = netlink_data_ready; |
1528 | if (input) | |
cd40b7d3 | 1529 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1530 | |
b4b51029 | 1531 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1532 | goto out_sock_release; |
4fdb3bb7 | 1533 | |
77247bbb PM |
1534 | nlk = nlk_sk(sk); |
1535 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1536 | |
4fdb3bb7 | 1537 | netlink_table_grab(); |
b4b51029 EB |
1538 | if (!nl_table[unit].registered) { |
1539 | nl_table[unit].groups = groups; | |
5c398dc8 | 1540 | rcu_assign_pointer(nl_table[unit].listeners, listeners); |
b4b51029 EB |
1541 | nl_table[unit].cb_mutex = cb_mutex; |
1542 | nl_table[unit].module = module; | |
1543 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1544 | } else { |
1545 | kfree(listeners); | |
869e58f8 | 1546 | nl_table[unit].registered++; |
b4b51029 | 1547 | } |
4fdb3bb7 | 1548 | netlink_table_ungrab(); |
77247bbb PM |
1549 | return sk; |
1550 | ||
4fdb3bb7 | 1551 | out_sock_release: |
4277a083 | 1552 | kfree(listeners); |
9dfbec1f | 1553 | netlink_kernel_release(sk); |
23fe1866 PE |
1554 | return NULL; |
1555 | ||
1556 | out_sock_release_nosk: | |
4fdb3bb7 | 1557 | sock_release(sock); |
77247bbb | 1558 | return NULL; |
1da177e4 | 1559 | } |
6ac552fd | 1560 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1561 | |
b7c6ba6e DL |
1562 | |
1563 | void | |
1564 | netlink_kernel_release(struct sock *sk) | |
1565 | { | |
edf02087 | 1566 | sk_release_kernel(sk); |
b7c6ba6e DL |
1567 | } |
1568 | EXPORT_SYMBOL(netlink_kernel_release); | |
1569 | ||
d136f1bd | 1570 | int __netlink_change_ngroups(struct sock *sk, unsigned int groups) |
b4ff4f04 | 1571 | { |
5c398dc8 | 1572 | struct listeners *new, *old; |
b4ff4f04 | 1573 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
b4ff4f04 JB |
1574 | |
1575 | if (groups < 32) | |
1576 | groups = 32; | |
1577 | ||
b4ff4f04 | 1578 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { |
5c398dc8 ED |
1579 | new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); |
1580 | if (!new) | |
d136f1bd | 1581 | return -ENOMEM; |
33d480ce | 1582 | old = rcu_dereference_protected(tbl->listeners, 1); |
5c398dc8 ED |
1583 | memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); |
1584 | rcu_assign_pointer(tbl->listeners, new); | |
1585 | ||
37b6b935 | 1586 | kfree_rcu(old, rcu); |
b4ff4f04 JB |
1587 | } |
1588 | tbl->groups = groups; | |
1589 | ||
d136f1bd JB |
1590 | return 0; |
1591 | } | |
1592 | ||
1593 | /** | |
1594 | * netlink_change_ngroups - change number of multicast groups | |
1595 | * | |
1596 | * This changes the number of multicast groups that are available | |
1597 | * on a certain netlink family. Note that it is not possible to | |
1598 | * change the number of groups to below 32. Also note that it does | |
1599 | * not implicitly call netlink_clear_multicast_users() when the | |
1600 | * number of groups is reduced. | |
1601 | * | |
1602 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1603 | * @groups: The new number of groups. | |
1604 | */ | |
1605 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1606 | { | |
1607 | int err; | |
1608 | ||
1609 | netlink_table_grab(); | |
1610 | err = __netlink_change_ngroups(sk, groups); | |
b4ff4f04 | 1611 | netlink_table_ungrab(); |
d136f1bd | 1612 | |
b4ff4f04 JB |
1613 | return err; |
1614 | } | |
b4ff4f04 | 1615 | |
b8273570 JB |
1616 | void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) |
1617 | { | |
1618 | struct sock *sk; | |
1619 | struct hlist_node *node; | |
1620 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1621 | ||
1622 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1623 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1624 | } | |
1625 | ||
84659eb5 JB |
1626 | /** |
1627 | * netlink_clear_multicast_users - kick off multicast listeners | |
1628 | * | |
1629 | * This function removes all listeners from the given group. | |
1630 | * @ksk: The kernel netlink socket, as returned by | |
1631 | * netlink_kernel_create(). | |
1632 | * @group: The multicast group to clear. | |
1633 | */ | |
1634 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1635 | { | |
84659eb5 | 1636 | netlink_table_grab(); |
b8273570 | 1637 | __netlink_clear_multicast_users(ksk, group); |
84659eb5 JB |
1638 | netlink_table_ungrab(); |
1639 | } | |
84659eb5 | 1640 | |
1da177e4 | 1641 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1642 | { |
1643 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1644 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1645 | } |
6ac552fd | 1646 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1647 | |
1648 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1649 | { | |
91744f65 | 1650 | kfree_skb(cb->skb); |
1da177e4 LT |
1651 | kfree(cb); |
1652 | } | |
1653 | ||
a46621a3 DV |
1654 | struct nlmsghdr * |
1655 | __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags) | |
1656 | { | |
1657 | struct nlmsghdr *nlh; | |
1658 | int size = NLMSG_LENGTH(len); | |
1659 | ||
1660 | nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size)); | |
1661 | nlh->nlmsg_type = type; | |
1662 | nlh->nlmsg_len = size; | |
1663 | nlh->nlmsg_flags = flags; | |
1664 | nlh->nlmsg_pid = pid; | |
1665 | nlh->nlmsg_seq = seq; | |
1666 | if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) | |
1667 | memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size); | |
1668 | return nlh; | |
1669 | } | |
1670 | EXPORT_SYMBOL(__nlmsg_put); | |
1671 | ||
1da177e4 LT |
1672 | /* |
1673 | * It looks a bit ugly. | |
1674 | * It would be better to create kernel thread. | |
1675 | */ | |
1676 | ||
1677 | static int netlink_dump(struct sock *sk) | |
1678 | { | |
1679 | struct netlink_sock *nlk = nlk_sk(sk); | |
1680 | struct netlink_callback *cb; | |
c7ac8679 | 1681 | struct sk_buff *skb = NULL; |
1da177e4 | 1682 | struct nlmsghdr *nlh; |
bf8b79e4 | 1683 | int len, err = -ENOBUFS; |
c7ac8679 | 1684 | int alloc_size; |
1da177e4 | 1685 | |
af65bdfc | 1686 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1687 | |
1688 | cb = nlk->cb; | |
1689 | if (cb == NULL) { | |
bf8b79e4 TG |
1690 | err = -EINVAL; |
1691 | goto errout_skb; | |
1da177e4 LT |
1692 | } |
1693 | ||
c7ac8679 GR |
1694 | alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); |
1695 | ||
1696 | skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL); | |
1697 | if (!skb) | |
c63d6ea3 | 1698 | goto errout_skb; |
c7ac8679 | 1699 | |
1da177e4 LT |
1700 | len = cb->dump(skb, cb); |
1701 | ||
1702 | if (len > 0) { | |
af65bdfc | 1703 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1704 | |
1705 | if (sk_filter(sk, skb)) | |
1706 | kfree_skb(skb); | |
4a7e7c2a ED |
1707 | else |
1708 | __netlink_sendskb(sk, skb); | |
1da177e4 LT |
1709 | return 0; |
1710 | } | |
1711 | ||
bf8b79e4 TG |
1712 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1713 | if (!nlh) | |
1714 | goto errout_skb; | |
1715 | ||
670dc283 JB |
1716 | nl_dump_check_consistent(cb, nlh); |
1717 | ||
bf8b79e4 TG |
1718 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); |
1719 | ||
b1153f29 SH |
1720 | if (sk_filter(sk, skb)) |
1721 | kfree_skb(skb); | |
4a7e7c2a ED |
1722 | else |
1723 | __netlink_sendskb(sk, skb); | |
1da177e4 | 1724 | |
a8f74b22 TG |
1725 | if (cb->done) |
1726 | cb->done(cb); | |
1da177e4 | 1727 | nlk->cb = NULL; |
af65bdfc | 1728 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1729 | |
1730 | netlink_destroy_callback(cb); | |
1da177e4 | 1731 | return 0; |
1797754e | 1732 | |
bf8b79e4 | 1733 | errout_skb: |
af65bdfc | 1734 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 | 1735 | kfree_skb(skb); |
bf8b79e4 | 1736 | return err; |
1da177e4 LT |
1737 | } |
1738 | ||
1739 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
3a6c2b41 | 1740 | const struct nlmsghdr *nlh, |
80d326fa | 1741 | struct netlink_dump_control *control) |
1da177e4 LT |
1742 | { |
1743 | struct netlink_callback *cb; | |
1744 | struct sock *sk; | |
1745 | struct netlink_sock *nlk; | |
b44d211e | 1746 | int ret; |
1da177e4 | 1747 | |
0da974f4 | 1748 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1749 | if (cb == NULL) |
1750 | return -ENOBUFS; | |
1751 | ||
80d326fa PNA |
1752 | cb->dump = control->dump; |
1753 | cb->done = control->done; | |
1da177e4 | 1754 | cb->nlh = nlh; |
7175c883 | 1755 | cb->data = control->data; |
80d326fa | 1756 | cb->min_dump_alloc = control->min_dump_alloc; |
1da177e4 LT |
1757 | atomic_inc(&skb->users); |
1758 | cb->skb = skb; | |
1759 | ||
3b1e0a65 | 1760 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1761 | if (sk == NULL) { |
1762 | netlink_destroy_callback(cb); | |
1763 | return -ECONNREFUSED; | |
1764 | } | |
1765 | nlk = nlk_sk(sk); | |
3f660d66 | 1766 | /* A dump is in progress... */ |
af65bdfc | 1767 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1768 | if (nlk->cb) { |
af65bdfc | 1769 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1770 | netlink_destroy_callback(cb); |
1771 | sock_put(sk); | |
1772 | return -EBUSY; | |
1773 | } | |
1774 | nlk->cb = cb; | |
af65bdfc | 1775 | mutex_unlock(nlk->cb_mutex); |
1da177e4 | 1776 | |
b44d211e AV |
1777 | ret = netlink_dump(sk); |
1778 | ||
1da177e4 | 1779 | sock_put(sk); |
5c58298c | 1780 | |
b44d211e AV |
1781 | if (ret) |
1782 | return ret; | |
1783 | ||
5c58298c DL |
1784 | /* We successfully started a dump, by returning -EINTR we |
1785 | * signal not to send ACK even if it was requested. | |
1786 | */ | |
1787 | return -EINTR; | |
1da177e4 | 1788 | } |
6ac552fd | 1789 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1790 | |
1791 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1792 | { | |
1793 | struct sk_buff *skb; | |
1794 | struct nlmsghdr *rep; | |
1795 | struct nlmsgerr *errmsg; | |
339bf98f | 1796 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1797 | |
339bf98f TG |
1798 | /* error messages get the original request appened */ |
1799 | if (err) | |
1800 | payload += nlmsg_len(nlh); | |
1da177e4 | 1801 | |
339bf98f | 1802 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1803 | if (!skb) { |
1804 | struct sock *sk; | |
1805 | ||
3b1e0a65 | 1806 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1807 | in_skb->sk->sk_protocol, |
1da177e4 LT |
1808 | NETLINK_CB(in_skb).pid); |
1809 | if (sk) { | |
1810 | sk->sk_err = ENOBUFS; | |
1811 | sk->sk_error_report(sk); | |
1812 | sock_put(sk); | |
1813 | } | |
1814 | return; | |
1815 | } | |
1816 | ||
1817 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
5dba93ae | 1818 | NLMSG_ERROR, payload, 0); |
bf8b79e4 | 1819 | errmsg = nlmsg_data(rep); |
1da177e4 | 1820 | errmsg->error = err; |
bf8b79e4 | 1821 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1822 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1823 | } | |
6ac552fd | 1824 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1825 | |
cd40b7d3 | 1826 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1827 | struct nlmsghdr *)) |
82ace47a | 1828 | { |
82ace47a TG |
1829 | struct nlmsghdr *nlh; |
1830 | int err; | |
1831 | ||
1832 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1833 | int msglen; |
1834 | ||
b529ccf2 | 1835 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1836 | err = 0; |
82ace47a | 1837 | |
ad8e4b75 | 1838 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1839 | return 0; |
1840 | ||
d35b6856 TG |
1841 | /* Only requests are handled by the kernel */ |
1842 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1843 | goto ack; |
45e7ae7f TG |
1844 | |
1845 | /* Skip control messages */ | |
1846 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1847 | goto ack; |
d35b6856 | 1848 | |
1d00a4eb | 1849 | err = cb(skb, nlh); |
5c58298c DL |
1850 | if (err == -EINTR) |
1851 | goto skip; | |
1852 | ||
1853 | ack: | |
d35b6856 | 1854 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1855 | netlink_ack(skb, nlh, err); |
82ace47a | 1856 | |
5c58298c | 1857 | skip: |
6ac552fd | 1858 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1859 | if (msglen > skb->len) |
1860 | msglen = skb->len; | |
1861 | skb_pull(skb, msglen); | |
82ace47a TG |
1862 | } |
1863 | ||
1864 | return 0; | |
1865 | } | |
6ac552fd | 1866 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1867 | |
d387f6ad TG |
1868 | /** |
1869 | * nlmsg_notify - send a notification netlink message | |
1870 | * @sk: netlink socket to use | |
1871 | * @skb: notification message | |
1872 | * @pid: destination netlink pid for reports or 0 | |
1873 | * @group: destination multicast group or 0 | |
1874 | * @report: 1 to report back, 0 to disable | |
1875 | * @flags: allocation flags | |
1876 | */ | |
1877 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1878 | unsigned int group, int report, gfp_t flags) | |
1879 | { | |
1880 | int err = 0; | |
1881 | ||
1882 | if (group) { | |
1883 | int exclude_pid = 0; | |
1884 | ||
1885 | if (report) { | |
1886 | atomic_inc(&skb->users); | |
1887 | exclude_pid = pid; | |
1888 | } | |
1889 | ||
1ce85fe4 PNA |
1890 | /* errors reported via destination sk->sk_err, but propagate |
1891 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
1892 | err = nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
d387f6ad TG |
1893 | } |
1894 | ||
1ce85fe4 PNA |
1895 | if (report) { |
1896 | int err2; | |
1897 | ||
1898 | err2 = nlmsg_unicast(sk, skb, pid); | |
1899 | if (!err || err == -ESRCH) | |
1900 | err = err2; | |
1901 | } | |
d387f6ad TG |
1902 | |
1903 | return err; | |
1904 | } | |
6ac552fd | 1905 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1906 | |
1da177e4 LT |
1907 | #ifdef CONFIG_PROC_FS |
1908 | struct nl_seq_iter { | |
e372c414 | 1909 | struct seq_net_private p; |
1da177e4 LT |
1910 | int link; |
1911 | int hash_idx; | |
1912 | }; | |
1913 | ||
1914 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1915 | { | |
1916 | struct nl_seq_iter *iter = seq->private; | |
1917 | int i, j; | |
1918 | struct sock *s; | |
1919 | struct hlist_node *node; | |
1920 | loff_t off = 0; | |
1921 | ||
6ac552fd | 1922 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1923 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1924 | ||
1925 | for (j = 0; j <= hash->mask; j++) { | |
1926 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1927 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1928 | continue; |
1da177e4 LT |
1929 | if (off == pos) { |
1930 | iter->link = i; | |
1931 | iter->hash_idx = j; | |
1932 | return s; | |
1933 | } | |
1934 | ++off; | |
1935 | } | |
1936 | } | |
1937 | } | |
1938 | return NULL; | |
1939 | } | |
1940 | ||
1941 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1942 | __acquires(nl_table_lock) |
1da177e4 LT |
1943 | { |
1944 | read_lock(&nl_table_lock); | |
1945 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1946 | } | |
1947 | ||
1948 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1949 | { | |
1950 | struct sock *s; | |
1951 | struct nl_seq_iter *iter; | |
1952 | int i, j; | |
1953 | ||
1954 | ++*pos; | |
1955 | ||
1956 | if (v == SEQ_START_TOKEN) | |
1957 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1958 | |
b4b51029 EB |
1959 | iter = seq->private; |
1960 | s = v; | |
1961 | do { | |
1962 | s = sk_next(s); | |
1218854a | 1963 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
1964 | if (s) |
1965 | return s; | |
1966 | ||
1da177e4 LT |
1967 | i = iter->link; |
1968 | j = iter->hash_idx + 1; | |
1969 | ||
1970 | do { | |
1971 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1972 | ||
1973 | for (; j <= hash->mask; j++) { | |
1974 | s = sk_head(&hash->table[j]); | |
1218854a | 1975 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1976 | s = sk_next(s); |
1da177e4 LT |
1977 | if (s) { |
1978 | iter->link = i; | |
1979 | iter->hash_idx = j; | |
1980 | return s; | |
1981 | } | |
1982 | } | |
1983 | ||
1984 | j = 0; | |
1985 | } while (++i < MAX_LINKS); | |
1986 | ||
1987 | return NULL; | |
1988 | } | |
1989 | ||
1990 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1991 | __releases(nl_table_lock) |
1da177e4 LT |
1992 | { |
1993 | read_unlock(&nl_table_lock); | |
1994 | } | |
1995 | ||
1996 | ||
1997 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1998 | { | |
1999 | if (v == SEQ_START_TOKEN) | |
2000 | seq_puts(seq, | |
2001 | "sk Eth Pid Groups " | |
cf0aa4e0 | 2002 | "Rmem Wmem Dump Locks Drops Inode\n"); |
1da177e4 LT |
2003 | else { |
2004 | struct sock *s = v; | |
2005 | struct netlink_sock *nlk = nlk_sk(s); | |
2006 | ||
71338aa7 | 2007 | seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n", |
1da177e4 LT |
2008 | s, |
2009 | s->sk_protocol, | |
2010 | nlk->pid, | |
513c2500 | 2011 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
2012 | sk_rmem_alloc_get(s), |
2013 | sk_wmem_alloc_get(s), | |
1da177e4 | 2014 | nlk->cb, |
38938bfe | 2015 | atomic_read(&s->sk_refcnt), |
cf0aa4e0 MY |
2016 | atomic_read(&s->sk_drops), |
2017 | sock_i_ino(s) | |
1da177e4 LT |
2018 | ); |
2019 | ||
2020 | } | |
2021 | return 0; | |
2022 | } | |
2023 | ||
56b3d975 | 2024 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
2025 | .start = netlink_seq_start, |
2026 | .next = netlink_seq_next, | |
2027 | .stop = netlink_seq_stop, | |
2028 | .show = netlink_seq_show, | |
2029 | }; | |
2030 | ||
2031 | ||
2032 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
2033 | { | |
e372c414 DL |
2034 | return seq_open_net(inode, file, &netlink_seq_ops, |
2035 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
2036 | } |
2037 | ||
da7071d7 | 2038 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2039 | .owner = THIS_MODULE, |
2040 | .open = netlink_seq_open, | |
2041 | .read = seq_read, | |
2042 | .llseek = seq_lseek, | |
e372c414 | 2043 | .release = seq_release_net, |
1da177e4 LT |
2044 | }; |
2045 | ||
2046 | #endif | |
2047 | ||
2048 | int netlink_register_notifier(struct notifier_block *nb) | |
2049 | { | |
e041c683 | 2050 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2051 | } |
6ac552fd | 2052 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2053 | |
2054 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2055 | { | |
e041c683 | 2056 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2057 | } |
6ac552fd | 2058 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2059 | |
90ddc4f0 | 2060 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2061 | .family = PF_NETLINK, |
2062 | .owner = THIS_MODULE, | |
2063 | .release = netlink_release, | |
2064 | .bind = netlink_bind, | |
2065 | .connect = netlink_connect, | |
2066 | .socketpair = sock_no_socketpair, | |
2067 | .accept = sock_no_accept, | |
2068 | .getname = netlink_getname, | |
2069 | .poll = datagram_poll, | |
2070 | .ioctl = sock_no_ioctl, | |
2071 | .listen = sock_no_listen, | |
2072 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2073 | .setsockopt = netlink_setsockopt, |
2074 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2075 | .sendmsg = netlink_sendmsg, |
2076 | .recvmsg = netlink_recvmsg, | |
2077 | .mmap = sock_no_mmap, | |
2078 | .sendpage = sock_no_sendpage, | |
2079 | }; | |
2080 | ||
ec1b4cf7 | 2081 | static const struct net_proto_family netlink_family_ops = { |
1da177e4 LT |
2082 | .family = PF_NETLINK, |
2083 | .create = netlink_create, | |
2084 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2085 | }; | |
2086 | ||
4665079c | 2087 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2088 | { |
2089 | #ifdef CONFIG_PROC_FS | |
2090 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
2091 | return -ENOMEM; | |
2092 | #endif | |
2093 | return 0; | |
2094 | } | |
2095 | ||
4665079c | 2096 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2097 | { |
2098 | #ifdef CONFIG_PROC_FS | |
2099 | proc_net_remove(net, "netlink"); | |
2100 | #endif | |
2101 | } | |
2102 | ||
b963ea89 DM |
2103 | static void __init netlink_add_usersock_entry(void) |
2104 | { | |
5c398dc8 | 2105 | struct listeners *listeners; |
b963ea89 DM |
2106 | int groups = 32; |
2107 | ||
5c398dc8 | 2108 | listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); |
b963ea89 | 2109 | if (!listeners) |
5c398dc8 | 2110 | panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); |
b963ea89 DM |
2111 | |
2112 | netlink_table_grab(); | |
2113 | ||
2114 | nl_table[NETLINK_USERSOCK].groups = groups; | |
5c398dc8 | 2115 | rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); |
b963ea89 DM |
2116 | nl_table[NETLINK_USERSOCK].module = THIS_MODULE; |
2117 | nl_table[NETLINK_USERSOCK].registered = 1; | |
2118 | ||
2119 | netlink_table_ungrab(); | |
2120 | } | |
2121 | ||
022cbae6 | 2122 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2123 | .init = netlink_net_init, |
2124 | .exit = netlink_net_exit, | |
2125 | }; | |
2126 | ||
1da177e4 LT |
2127 | static int __init netlink_proto_init(void) |
2128 | { | |
2129 | struct sk_buff *dummy_skb; | |
2130 | int i; | |
26ff5ddc | 2131 | unsigned long limit; |
1da177e4 LT |
2132 | unsigned int order; |
2133 | int err = proto_register(&netlink_proto, 0); | |
2134 | ||
2135 | if (err != 0) | |
2136 | goto out; | |
2137 | ||
ef047f5e | 2138 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 2139 | |
0da974f4 | 2140 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2141 | if (!nl_table) |
2142 | goto panic; | |
1da177e4 | 2143 | |
4481374c JB |
2144 | if (totalram_pages >= (128 * 1024)) |
2145 | limit = totalram_pages >> (21 - PAGE_SHIFT); | |
1da177e4 | 2146 | else |
4481374c | 2147 | limit = totalram_pages >> (23 - PAGE_SHIFT); |
1da177e4 | 2148 | |
26ff5ddc DC |
2149 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2150 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2151 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2152 | |
2153 | for (i = 0; i < MAX_LINKS; i++) { | |
2154 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
2155 | ||
ea72912c | 2156 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2157 | if (!hash->table) { |
2158 | while (i-- > 0) | |
2159 | nl_pid_hash_free(nl_table[i].hash.table, | |
2160 | 1 * sizeof(*hash->table)); | |
2161 | kfree(nl_table); | |
fab2caf6 | 2162 | goto panic; |
1da177e4 | 2163 | } |
1da177e4 LT |
2164 | hash->max_shift = order; |
2165 | hash->shift = 0; | |
2166 | hash->mask = 0; | |
2167 | hash->rehash_time = jiffies; | |
2168 | } | |
2169 | ||
b963ea89 DM |
2170 | netlink_add_usersock_entry(); |
2171 | ||
1da177e4 | 2172 | sock_register(&netlink_family_ops); |
b4b51029 | 2173 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2174 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2175 | rtnetlink_init(); |
2176 | out: | |
2177 | return err; | |
fab2caf6 AM |
2178 | panic: |
2179 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2180 | } |
2181 | ||
1da177e4 | 2182 | core_initcall(netlink_proto_init); |