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 | ||
6c04bb18 JB |
86 | struct listeners_rcu_head { |
87 | struct rcu_head rcu_head; | |
88 | void *ptr; | |
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 | ||
aed81560 DL |
101 | static inline int netlink_is_kernel(struct sock *sk) |
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; | |
4277a083 | 122 | unsigned long *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 | |
d629b836 PM |
142 | static u32 netlink_group_mask(u32 group) |
143 | { | |
144 | return group ? 1 << (group - 1) : 0; | |
145 | } | |
146 | ||
1da177e4 LT |
147 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
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 | ||
180 | static void netlink_table_grab(void) | |
9a429c49 | 181 | __acquires(nl_table_lock) |
1da177e4 | 182 | { |
6abd219c | 183 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
184 | |
185 | if (atomic_read(&nl_table_users)) { | |
186 | DECLARE_WAITQUEUE(wait, current); | |
187 | ||
188 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
6ac552fd | 189 | for (;;) { |
1da177e4 LT |
190 | set_current_state(TASK_UNINTERRUPTIBLE); |
191 | if (atomic_read(&nl_table_users) == 0) | |
192 | break; | |
6abd219c | 193 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 194 | schedule(); |
6abd219c | 195 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
196 | } |
197 | ||
198 | __set_current_state(TASK_RUNNING); | |
199 | remove_wait_queue(&nl_table_wait, &wait); | |
200 | } | |
201 | } | |
202 | ||
3f252526 | 203 | static void netlink_table_ungrab(void) |
9a429c49 | 204 | __releases(nl_table_lock) |
1da177e4 | 205 | { |
6abd219c | 206 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
207 | wake_up(&nl_table_wait); |
208 | } | |
209 | ||
6ac552fd | 210 | static inline void |
1da177e4 LT |
211 | netlink_lock_table(void) |
212 | { | |
213 | /* read_lock() synchronizes us to netlink_table_grab */ | |
214 | ||
215 | read_lock(&nl_table_lock); | |
216 | atomic_inc(&nl_table_users); | |
217 | read_unlock(&nl_table_lock); | |
218 | } | |
219 | ||
6ac552fd | 220 | static inline void |
1da177e4 LT |
221 | netlink_unlock_table(void) |
222 | { | |
223 | if (atomic_dec_and_test(&nl_table_users)) | |
224 | wake_up(&nl_table_wait); | |
225 | } | |
226 | ||
6ac552fd PM |
227 | static inline struct sock *netlink_lookup(struct net *net, int protocol, |
228 | u32 pid) | |
1da177e4 LT |
229 | { |
230 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
231 | struct hlist_head *head; | |
232 | struct sock *sk; | |
233 | struct hlist_node *node; | |
234 | ||
235 | read_lock(&nl_table_lock); | |
236 | head = nl_pid_hashfn(hash, pid); | |
237 | sk_for_each(sk, node, head) { | |
878628fb | 238 | if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { |
1da177e4 LT |
239 | sock_hold(sk); |
240 | goto found; | |
241 | } | |
242 | } | |
243 | sk = NULL; | |
244 | found: | |
245 | read_unlock(&nl_table_lock); | |
246 | return sk; | |
247 | } | |
248 | ||
ea72912c | 249 | static inline struct hlist_head *nl_pid_hash_zalloc(size_t size) |
1da177e4 LT |
250 | { |
251 | if (size <= PAGE_SIZE) | |
ea72912c | 252 | return kzalloc(size, GFP_ATOMIC); |
1da177e4 LT |
253 | else |
254 | return (struct hlist_head *) | |
ea72912c ED |
255 | __get_free_pages(GFP_ATOMIC | __GFP_ZERO, |
256 | get_order(size)); | |
1da177e4 LT |
257 | } |
258 | ||
259 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
260 | { | |
261 | if (size <= PAGE_SIZE) | |
262 | kfree(table); | |
263 | else | |
264 | free_pages((unsigned long)table, get_order(size)); | |
265 | } | |
266 | ||
267 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
268 | { | |
269 | unsigned int omask, mask, shift; | |
270 | size_t osize, size; | |
271 | struct hlist_head *otable, *table; | |
272 | int i; | |
273 | ||
274 | omask = mask = hash->mask; | |
275 | osize = size = (mask + 1) * sizeof(*table); | |
276 | shift = hash->shift; | |
277 | ||
278 | if (grow) { | |
279 | if (++shift > hash->max_shift) | |
280 | return 0; | |
281 | mask = mask * 2 + 1; | |
282 | size *= 2; | |
283 | } | |
284 | ||
ea72912c | 285 | table = nl_pid_hash_zalloc(size); |
1da177e4 LT |
286 | if (!table) |
287 | return 0; | |
288 | ||
1da177e4 LT |
289 | otable = hash->table; |
290 | hash->table = table; | |
291 | hash->mask = mask; | |
292 | hash->shift = shift; | |
293 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
294 | ||
295 | for (i = 0; i <= omask; i++) { | |
296 | struct sock *sk; | |
297 | struct hlist_node *node, *tmp; | |
298 | ||
299 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
300 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
301 | } | |
302 | ||
303 | nl_pid_hash_free(otable, osize); | |
304 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
305 | return 1; | |
306 | } | |
307 | ||
308 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
309 | { | |
310 | int avg = hash->entries >> hash->shift; | |
311 | ||
312 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
313 | return 1; | |
314 | ||
315 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
316 | nl_pid_hash_rehash(hash, 0); | |
317 | return 1; | |
318 | } | |
319 | ||
320 | return 0; | |
321 | } | |
322 | ||
90ddc4f0 | 323 | static const struct proto_ops netlink_ops; |
1da177e4 | 324 | |
4277a083 PM |
325 | static void |
326 | netlink_update_listeners(struct sock *sk) | |
327 | { | |
328 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
329 | struct hlist_node *node; | |
330 | unsigned long mask; | |
331 | unsigned int i; | |
332 | ||
b4ff4f04 | 333 | for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { |
4277a083 | 334 | mask = 0; |
b4ff4f04 JB |
335 | sk_for_each_bound(sk, node, &tbl->mc_list) { |
336 | if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) | |
337 | mask |= nlk_sk(sk)->groups[i]; | |
338 | } | |
4277a083 PM |
339 | tbl->listeners[i] = mask; |
340 | } | |
341 | /* this function is only called with the netlink table "grabbed", which | |
342 | * makes sure updates are visible before bind or setsockopt return. */ | |
343 | } | |
344 | ||
b4b51029 | 345 | static int netlink_insert(struct sock *sk, struct net *net, u32 pid) |
1da177e4 LT |
346 | { |
347 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
348 | struct hlist_head *head; | |
349 | int err = -EADDRINUSE; | |
350 | struct sock *osk; | |
351 | struct hlist_node *node; | |
352 | int len; | |
353 | ||
354 | netlink_table_grab(); | |
355 | head = nl_pid_hashfn(hash, pid); | |
356 | len = 0; | |
357 | sk_for_each(osk, node, head) { | |
878628fb | 358 | if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) |
1da177e4 LT |
359 | break; |
360 | len++; | |
361 | } | |
362 | if (node) | |
363 | goto err; | |
364 | ||
365 | err = -EBUSY; | |
366 | if (nlk_sk(sk)->pid) | |
367 | goto err; | |
368 | ||
369 | err = -ENOMEM; | |
370 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
371 | goto err; | |
372 | ||
373 | if (len && nl_pid_hash_dilute(hash, len)) | |
374 | head = nl_pid_hashfn(hash, pid); | |
375 | hash->entries++; | |
376 | nlk_sk(sk)->pid = pid; | |
377 | sk_add_node(sk, head); | |
378 | err = 0; | |
379 | ||
380 | err: | |
381 | netlink_table_ungrab(); | |
382 | return err; | |
383 | } | |
384 | ||
385 | static void netlink_remove(struct sock *sk) | |
386 | { | |
387 | netlink_table_grab(); | |
d470e3b4 DM |
388 | if (sk_del_node_init(sk)) |
389 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 390 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
391 | __sk_del_bind_node(sk); |
392 | netlink_table_ungrab(); | |
393 | } | |
394 | ||
395 | static struct proto netlink_proto = { | |
396 | .name = "NETLINK", | |
397 | .owner = THIS_MODULE, | |
398 | .obj_size = sizeof(struct netlink_sock), | |
399 | }; | |
400 | ||
1b8d7ae4 EB |
401 | static int __netlink_create(struct net *net, struct socket *sock, |
402 | struct mutex *cb_mutex, int protocol) | |
1da177e4 LT |
403 | { |
404 | struct sock *sk; | |
405 | struct netlink_sock *nlk; | |
ab33a171 PM |
406 | |
407 | sock->ops = &netlink_ops; | |
408 | ||
6257ff21 | 409 | sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); |
ab33a171 PM |
410 | if (!sk) |
411 | return -ENOMEM; | |
412 | ||
413 | sock_init_data(sock, sk); | |
414 | ||
415 | nlk = nlk_sk(sk); | |
ffa4d721 PM |
416 | if (cb_mutex) |
417 | nlk->cb_mutex = cb_mutex; | |
418 | else { | |
419 | nlk->cb_mutex = &nlk->cb_def_mutex; | |
420 | mutex_init(nlk->cb_mutex); | |
421 | } | |
ab33a171 PM |
422 | init_waitqueue_head(&nlk->wait); |
423 | ||
424 | sk->sk_destruct = netlink_sock_destruct; | |
425 | sk->sk_protocol = protocol; | |
426 | return 0; | |
427 | } | |
428 | ||
1b8d7ae4 | 429 | static int netlink_create(struct net *net, struct socket *sock, int protocol) |
ab33a171 PM |
430 | { |
431 | struct module *module = NULL; | |
af65bdfc | 432 | struct mutex *cb_mutex; |
f7fa9b10 | 433 | struct netlink_sock *nlk; |
ab33a171 | 434 | int err = 0; |
1da177e4 LT |
435 | |
436 | sock->state = SS_UNCONNECTED; | |
437 | ||
438 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
439 | return -ESOCKTNOSUPPORT; | |
440 | ||
6ac552fd | 441 | if (protocol < 0 || protocol >= MAX_LINKS) |
1da177e4 LT |
442 | return -EPROTONOSUPPORT; |
443 | ||
77247bbb | 444 | netlink_lock_table(); |
95a5afca | 445 | #ifdef CONFIG_MODULES |
ab33a171 | 446 | if (!nl_table[protocol].registered) { |
77247bbb | 447 | netlink_unlock_table(); |
4fdb3bb7 | 448 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 449 | netlink_lock_table(); |
4fdb3bb7 | 450 | } |
ab33a171 PM |
451 | #endif |
452 | if (nl_table[protocol].registered && | |
453 | try_module_get(nl_table[protocol].module)) | |
454 | module = nl_table[protocol].module; | |
af65bdfc | 455 | cb_mutex = nl_table[protocol].cb_mutex; |
77247bbb | 456 | netlink_unlock_table(); |
4fdb3bb7 | 457 | |
6ac552fd PM |
458 | err = __netlink_create(net, sock, cb_mutex, protocol); |
459 | if (err < 0) | |
f7fa9b10 PM |
460 | goto out_module; |
461 | ||
6f756a8c | 462 | local_bh_disable(); |
c1fd3b94 | 463 | sock_prot_inuse_add(net, &netlink_proto, 1); |
6f756a8c DM |
464 | local_bh_enable(); |
465 | ||
f7fa9b10 | 466 | nlk = nlk_sk(sock->sk); |
f7fa9b10 | 467 | nlk->module = module; |
ab33a171 PM |
468 | out: |
469 | return err; | |
1da177e4 | 470 | |
ab33a171 PM |
471 | out_module: |
472 | module_put(module); | |
473 | goto out; | |
1da177e4 LT |
474 | } |
475 | ||
476 | static int netlink_release(struct socket *sock) | |
477 | { | |
478 | struct sock *sk = sock->sk; | |
479 | struct netlink_sock *nlk; | |
480 | ||
481 | if (!sk) | |
482 | return 0; | |
483 | ||
484 | netlink_remove(sk); | |
ac57b3a9 | 485 | sock_orphan(sk); |
1da177e4 LT |
486 | nlk = nlk_sk(sk); |
487 | ||
3f660d66 HX |
488 | /* |
489 | * OK. Socket is unlinked, any packets that arrive now | |
490 | * will be purged. | |
491 | */ | |
1da177e4 | 492 | |
1da177e4 LT |
493 | sock->sk = NULL; |
494 | wake_up_interruptible_all(&nlk->wait); | |
495 | ||
496 | skb_queue_purge(&sk->sk_write_queue); | |
497 | ||
f7fa9b10 | 498 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 | 499 | struct netlink_notify n = { |
3b1e0a65 | 500 | .net = sock_net(sk), |
1da177e4 LT |
501 | .protocol = sk->sk_protocol, |
502 | .pid = nlk->pid, | |
503 | }; | |
e041c683 AS |
504 | atomic_notifier_call_chain(&netlink_chain, |
505 | NETLINK_URELEASE, &n); | |
746fac4d | 506 | } |
4fdb3bb7 | 507 | |
5e7c001c | 508 | module_put(nlk->module); |
4fdb3bb7 | 509 | |
4277a083 | 510 | netlink_table_grab(); |
aed81560 | 511 | if (netlink_is_kernel(sk)) { |
869e58f8 DL |
512 | BUG_ON(nl_table[sk->sk_protocol].registered == 0); |
513 | if (--nl_table[sk->sk_protocol].registered == 0) { | |
514 | kfree(nl_table[sk->sk_protocol].listeners); | |
515 | nl_table[sk->sk_protocol].module = NULL; | |
516 | nl_table[sk->sk_protocol].registered = 0; | |
517 | } | |
4277a083 PM |
518 | } else if (nlk->subscriptions) |
519 | netlink_update_listeners(sk); | |
520 | netlink_table_ungrab(); | |
77247bbb | 521 | |
f7fa9b10 PM |
522 | kfree(nlk->groups); |
523 | nlk->groups = NULL; | |
524 | ||
3755810c | 525 | local_bh_disable(); |
c1fd3b94 | 526 | sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); |
3755810c | 527 | local_bh_enable(); |
1da177e4 LT |
528 | sock_put(sk); |
529 | return 0; | |
530 | } | |
531 | ||
532 | static int netlink_autobind(struct socket *sock) | |
533 | { | |
534 | struct sock *sk = sock->sk; | |
3b1e0a65 | 535 | struct net *net = sock_net(sk); |
1da177e4 LT |
536 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; |
537 | struct hlist_head *head; | |
538 | struct sock *osk; | |
539 | struct hlist_node *node; | |
c27bd492 | 540 | s32 pid = current->tgid; |
1da177e4 LT |
541 | int err; |
542 | static s32 rover = -4097; | |
543 | ||
544 | retry: | |
545 | cond_resched(); | |
546 | netlink_table_grab(); | |
547 | head = nl_pid_hashfn(hash, pid); | |
548 | sk_for_each(osk, node, head) { | |
878628fb | 549 | if (!net_eq(sock_net(osk), net)) |
b4b51029 | 550 | continue; |
1da177e4 LT |
551 | if (nlk_sk(osk)->pid == pid) { |
552 | /* Bind collision, search negative pid values. */ | |
553 | pid = rover--; | |
554 | if (rover > -4097) | |
555 | rover = -4097; | |
556 | netlink_table_ungrab(); | |
557 | goto retry; | |
558 | } | |
559 | } | |
560 | netlink_table_ungrab(); | |
561 | ||
b4b51029 | 562 | err = netlink_insert(sk, net, pid); |
1da177e4 LT |
563 | if (err == -EADDRINUSE) |
564 | goto retry; | |
d470e3b4 DM |
565 | |
566 | /* If 2 threads race to autobind, that is fine. */ | |
567 | if (err == -EBUSY) | |
568 | err = 0; | |
569 | ||
570 | return err; | |
1da177e4 LT |
571 | } |
572 | ||
746fac4d YH |
573 | static inline int netlink_capable(struct socket *sock, unsigned int flag) |
574 | { | |
1da177e4 LT |
575 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || |
576 | capable(CAP_NET_ADMIN); | |
746fac4d | 577 | } |
1da177e4 | 578 | |
f7fa9b10 PM |
579 | static void |
580 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
581 | { | |
582 | struct netlink_sock *nlk = nlk_sk(sk); | |
583 | ||
584 | if (nlk->subscriptions && !subscriptions) | |
585 | __sk_del_bind_node(sk); | |
586 | else if (!nlk->subscriptions && subscriptions) | |
587 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
588 | nlk->subscriptions = subscriptions; | |
589 | } | |
590 | ||
b4ff4f04 | 591 | static int netlink_realloc_groups(struct sock *sk) |
513c2500 PM |
592 | { |
593 | struct netlink_sock *nlk = nlk_sk(sk); | |
594 | unsigned int groups; | |
b4ff4f04 | 595 | unsigned long *new_groups; |
513c2500 PM |
596 | int err = 0; |
597 | ||
b4ff4f04 JB |
598 | netlink_table_grab(); |
599 | ||
513c2500 | 600 | groups = nl_table[sk->sk_protocol].groups; |
b4ff4f04 | 601 | if (!nl_table[sk->sk_protocol].registered) { |
513c2500 | 602 | err = -ENOENT; |
b4ff4f04 JB |
603 | goto out_unlock; |
604 | } | |
513c2500 | 605 | |
b4ff4f04 JB |
606 | if (nlk->ngroups >= groups) |
607 | goto out_unlock; | |
513c2500 | 608 | |
b4ff4f04 JB |
609 | new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); |
610 | if (new_groups == NULL) { | |
611 | err = -ENOMEM; | |
612 | goto out_unlock; | |
613 | } | |
6ac552fd | 614 | memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, |
b4ff4f04 JB |
615 | NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); |
616 | ||
617 | nlk->groups = new_groups; | |
513c2500 | 618 | nlk->ngroups = groups; |
b4ff4f04 JB |
619 | out_unlock: |
620 | netlink_table_ungrab(); | |
621 | return err; | |
513c2500 PM |
622 | } |
623 | ||
6ac552fd PM |
624 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, |
625 | int addr_len) | |
1da177e4 LT |
626 | { |
627 | struct sock *sk = sock->sk; | |
3b1e0a65 | 628 | struct net *net = sock_net(sk); |
1da177e4 LT |
629 | struct netlink_sock *nlk = nlk_sk(sk); |
630 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
631 | int err; | |
746fac4d | 632 | |
1da177e4 LT |
633 | if (nladdr->nl_family != AF_NETLINK) |
634 | return -EINVAL; | |
635 | ||
636 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
637 | if (nladdr->nl_groups) { |
638 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
639 | return -EPERM; | |
b4ff4f04 JB |
640 | err = netlink_realloc_groups(sk); |
641 | if (err) | |
642 | return err; | |
513c2500 | 643 | } |
1da177e4 LT |
644 | |
645 | if (nlk->pid) { | |
646 | if (nladdr->nl_pid != nlk->pid) | |
647 | return -EINVAL; | |
648 | } else { | |
649 | err = nladdr->nl_pid ? | |
b4b51029 | 650 | netlink_insert(sk, net, nladdr->nl_pid) : |
1da177e4 LT |
651 | netlink_autobind(sock); |
652 | if (err) | |
653 | return err; | |
654 | } | |
655 | ||
513c2500 | 656 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
657 | return 0; |
658 | ||
659 | netlink_table_grab(); | |
f7fa9b10 | 660 | netlink_update_subscriptions(sk, nlk->subscriptions + |
746fac4d YH |
661 | hweight32(nladdr->nl_groups) - |
662 | hweight32(nlk->groups[0])); | |
663 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 664 | netlink_update_listeners(sk); |
1da177e4 LT |
665 | netlink_table_ungrab(); |
666 | ||
667 | return 0; | |
668 | } | |
669 | ||
670 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
671 | int alen, int flags) | |
672 | { | |
673 | int err = 0; | |
674 | struct sock *sk = sock->sk; | |
675 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 676 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
1da177e4 LT |
677 | |
678 | if (addr->sa_family == AF_UNSPEC) { | |
679 | sk->sk_state = NETLINK_UNCONNECTED; | |
680 | nlk->dst_pid = 0; | |
d629b836 | 681 | nlk->dst_group = 0; |
1da177e4 LT |
682 | return 0; |
683 | } | |
684 | if (addr->sa_family != AF_NETLINK) | |
685 | return -EINVAL; | |
686 | ||
687 | /* Only superuser is allowed to send multicasts */ | |
688 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
689 | return -EPERM; | |
690 | ||
691 | if (!nlk->pid) | |
692 | err = netlink_autobind(sock); | |
693 | ||
694 | if (err == 0) { | |
695 | sk->sk_state = NETLINK_CONNECTED; | |
696 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 697 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
698 | } |
699 | ||
700 | return err; | |
701 | } | |
702 | ||
6ac552fd PM |
703 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, |
704 | int *addr_len, int peer) | |
1da177e4 LT |
705 | { |
706 | struct sock *sk = sock->sk; | |
707 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 708 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; |
746fac4d | 709 | |
1da177e4 LT |
710 | nladdr->nl_family = AF_NETLINK; |
711 | nladdr->nl_pad = 0; | |
712 | *addr_len = sizeof(*nladdr); | |
713 | ||
714 | if (peer) { | |
715 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 716 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
717 | } else { |
718 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 719 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
720 | } |
721 | return 0; | |
722 | } | |
723 | ||
724 | static void netlink_overrun(struct sock *sk) | |
725 | { | |
38938bfe PNA |
726 | struct netlink_sock *nlk = nlk_sk(sk); |
727 | ||
728 | if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { | |
729 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
730 | sk->sk_err = ENOBUFS; | |
731 | sk->sk_error_report(sk); | |
732 | } | |
1da177e4 | 733 | } |
38938bfe | 734 | atomic_inc(&sk->sk_drops); |
1da177e4 LT |
735 | } |
736 | ||
737 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
738 | { | |
1da177e4 LT |
739 | struct sock *sock; |
740 | struct netlink_sock *nlk; | |
741 | ||
3b1e0a65 | 742 | sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); |
1da177e4 LT |
743 | if (!sock) |
744 | return ERR_PTR(-ECONNREFUSED); | |
745 | ||
746 | /* Don't bother queuing skb if kernel socket has no input function */ | |
747 | nlk = nlk_sk(sock); | |
cd40b7d3 DL |
748 | if (sock->sk_state == NETLINK_CONNECTED && |
749 | nlk->dst_pid != nlk_sk(ssk)->pid) { | |
1da177e4 LT |
750 | sock_put(sock); |
751 | return ERR_PTR(-ECONNREFUSED); | |
752 | } | |
753 | return sock; | |
754 | } | |
755 | ||
756 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
757 | { | |
6db5fc5d | 758 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
759 | struct sock *sock; |
760 | ||
761 | if (!S_ISSOCK(inode->i_mode)) | |
762 | return ERR_PTR(-ENOTSOCK); | |
763 | ||
764 | sock = SOCKET_I(inode)->sk; | |
765 | if (sock->sk_family != AF_NETLINK) | |
766 | return ERR_PTR(-EINVAL); | |
767 | ||
768 | sock_hold(sock); | |
769 | return sock; | |
770 | } | |
771 | ||
772 | /* | |
773 | * Attach a skb to a netlink socket. | |
774 | * The caller must hold a reference to the destination socket. On error, the | |
775 | * reference is dropped. The skb is not send to the destination, just all | |
776 | * all error checks are performed and memory in the queue is reserved. | |
777 | * Return values: | |
778 | * < 0: error. skb freed, reference to sock dropped. | |
779 | * 0: continue | |
780 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
781 | */ | |
9457afee | 782 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, |
c3d8d1e3 | 783 | long *timeo, struct sock *ssk) |
1da177e4 LT |
784 | { |
785 | struct netlink_sock *nlk; | |
786 | ||
787 | nlk = nlk_sk(sk); | |
788 | ||
789 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
790 | test_bit(0, &nlk->state)) { | |
791 | DECLARE_WAITQUEUE(wait, current); | |
c3d8d1e3 | 792 | if (!*timeo) { |
aed81560 | 793 | if (!ssk || netlink_is_kernel(ssk)) |
1da177e4 LT |
794 | netlink_overrun(sk); |
795 | sock_put(sk); | |
796 | kfree_skb(skb); | |
797 | return -EAGAIN; | |
798 | } | |
799 | ||
800 | __set_current_state(TASK_INTERRUPTIBLE); | |
801 | add_wait_queue(&nlk->wait, &wait); | |
802 | ||
803 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
804 | test_bit(0, &nlk->state)) && | |
805 | !sock_flag(sk, SOCK_DEAD)) | |
c3d8d1e3 | 806 | *timeo = schedule_timeout(*timeo); |
1da177e4 LT |
807 | |
808 | __set_current_state(TASK_RUNNING); | |
809 | remove_wait_queue(&nlk->wait, &wait); | |
810 | sock_put(sk); | |
811 | ||
812 | if (signal_pending(current)) { | |
813 | kfree_skb(skb); | |
c3d8d1e3 | 814 | return sock_intr_errno(*timeo); |
1da177e4 LT |
815 | } |
816 | return 1; | |
817 | } | |
818 | skb_set_owner_r(skb, sk); | |
819 | return 0; | |
820 | } | |
821 | ||
7ee015e0 | 822 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 823 | { |
1da177e4 LT |
824 | int len = skb->len; |
825 | ||
1da177e4 LT |
826 | skb_queue_tail(&sk->sk_receive_queue, skb); |
827 | sk->sk_data_ready(sk, len); | |
828 | sock_put(sk); | |
829 | return len; | |
830 | } | |
831 | ||
832 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
833 | { | |
834 | kfree_skb(skb); | |
835 | sock_put(sk); | |
836 | } | |
837 | ||
37da647d | 838 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 839 | gfp_t allocation) |
1da177e4 LT |
840 | { |
841 | int delta; | |
842 | ||
843 | skb_orphan(skb); | |
844 | ||
4305b541 | 845 | delta = skb->end - skb->tail; |
1da177e4 LT |
846 | if (delta * 2 < skb->truesize) |
847 | return skb; | |
848 | ||
849 | if (skb_shared(skb)) { | |
850 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
851 | if (!nskb) | |
852 | return skb; | |
853 | kfree_skb(skb); | |
854 | skb = nskb; | |
855 | } | |
856 | ||
857 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
858 | skb->truesize -= delta; | |
859 | ||
860 | return skb; | |
861 | } | |
862 | ||
cd40b7d3 DL |
863 | static inline void netlink_rcv_wake(struct sock *sk) |
864 | { | |
865 | struct netlink_sock *nlk = nlk_sk(sk); | |
866 | ||
867 | if (skb_queue_empty(&sk->sk_receive_queue)) | |
868 | clear_bit(0, &nlk->state); | |
869 | if (!test_bit(0, &nlk->state)) | |
870 | wake_up_interruptible(&nlk->wait); | |
871 | } | |
872 | ||
873 | static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) | |
874 | { | |
875 | int ret; | |
876 | struct netlink_sock *nlk = nlk_sk(sk); | |
877 | ||
878 | ret = -ECONNREFUSED; | |
879 | if (nlk->netlink_rcv != NULL) { | |
880 | ret = skb->len; | |
881 | skb_set_owner_r(skb, sk); | |
882 | nlk->netlink_rcv(skb); | |
883 | } | |
884 | kfree_skb(skb); | |
885 | sock_put(sk); | |
886 | return ret; | |
887 | } | |
888 | ||
889 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, | |
890 | u32 pid, int nonblock) | |
1da177e4 LT |
891 | { |
892 | struct sock *sk; | |
893 | int err; | |
894 | long timeo; | |
895 | ||
896 | skb = netlink_trim(skb, gfp_any()); | |
897 | ||
898 | timeo = sock_sndtimeo(ssk, nonblock); | |
899 | retry: | |
900 | sk = netlink_getsockbypid(ssk, pid); | |
901 | if (IS_ERR(sk)) { | |
902 | kfree_skb(skb); | |
903 | return PTR_ERR(sk); | |
904 | } | |
cd40b7d3 DL |
905 | if (netlink_is_kernel(sk)) |
906 | return netlink_unicast_kernel(sk, skb); | |
907 | ||
b1153f29 | 908 | if (sk_filter(sk, skb)) { |
84874607 | 909 | err = skb->len; |
b1153f29 SH |
910 | kfree_skb(skb); |
911 | sock_put(sk); | |
912 | return err; | |
913 | } | |
914 | ||
9457afee | 915 | err = netlink_attachskb(sk, skb, &timeo, ssk); |
1da177e4 LT |
916 | if (err == 1) |
917 | goto retry; | |
918 | if (err) | |
919 | return err; | |
920 | ||
7ee015e0 | 921 | return netlink_sendskb(sk, skb); |
1da177e4 | 922 | } |
6ac552fd | 923 | EXPORT_SYMBOL(netlink_unicast); |
1da177e4 | 924 | |
4277a083 PM |
925 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
926 | { | |
927 | int res = 0; | |
b4ff4f04 | 928 | unsigned long *listeners; |
4277a083 | 929 | |
aed81560 | 930 | BUG_ON(!netlink_is_kernel(sk)); |
b4ff4f04 JB |
931 | |
932 | rcu_read_lock(); | |
933 | listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); | |
934 | ||
4277a083 | 935 | if (group - 1 < nl_table[sk->sk_protocol].groups) |
b4ff4f04 JB |
936 | res = test_bit(group - 1, listeners); |
937 | ||
938 | rcu_read_unlock(); | |
939 | ||
4277a083 PM |
940 | return res; |
941 | } | |
942 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
943 | ||
6ac552fd PM |
944 | static inline int netlink_broadcast_deliver(struct sock *sk, |
945 | struct sk_buff *skb) | |
1da177e4 LT |
946 | { |
947 | struct netlink_sock *nlk = nlk_sk(sk); | |
948 | ||
949 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
950 | !test_bit(0, &nlk->state)) { | |
951 | skb_set_owner_r(skb, sk); | |
952 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
953 | sk->sk_data_ready(sk, skb->len); | |
954 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
955 | } | |
956 | return -1; | |
957 | } | |
958 | ||
959 | struct netlink_broadcast_data { | |
960 | struct sock *exclude_sk; | |
b4b51029 | 961 | struct net *net; |
1da177e4 LT |
962 | u32 pid; |
963 | u32 group; | |
964 | int failure; | |
ff491a73 | 965 | int delivery_failure; |
1da177e4 LT |
966 | int congested; |
967 | int delivered; | |
7d877f3b | 968 | gfp_t allocation; |
1da177e4 LT |
969 | struct sk_buff *skb, *skb2; |
970 | }; | |
971 | ||
972 | static inline int do_one_broadcast(struct sock *sk, | |
973 | struct netlink_broadcast_data *p) | |
974 | { | |
975 | struct netlink_sock *nlk = nlk_sk(sk); | |
976 | int val; | |
977 | ||
978 | if (p->exclude_sk == sk) | |
979 | goto out; | |
980 | ||
f7fa9b10 PM |
981 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
982 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
983 | goto out; |
984 | ||
878628fb | 985 | if (!net_eq(sock_net(sk), p->net)) |
b4b51029 EB |
986 | goto out; |
987 | ||
1da177e4 LT |
988 | if (p->failure) { |
989 | netlink_overrun(sk); | |
990 | goto out; | |
991 | } | |
992 | ||
993 | sock_hold(sk); | |
994 | if (p->skb2 == NULL) { | |
68acc024 | 995 | if (skb_shared(p->skb)) { |
1da177e4 LT |
996 | p->skb2 = skb_clone(p->skb, p->allocation); |
997 | } else { | |
68acc024 TC |
998 | p->skb2 = skb_get(p->skb); |
999 | /* | |
1000 | * skb ownership may have been set when | |
1001 | * delivered to a previous socket. | |
1002 | */ | |
1003 | skb_orphan(p->skb2); | |
1da177e4 LT |
1004 | } |
1005 | } | |
1006 | if (p->skb2 == NULL) { | |
1007 | netlink_overrun(sk); | |
1008 | /* Clone failed. Notify ALL listeners. */ | |
1009 | p->failure = 1; | |
be0c22a4 PNA |
1010 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1011 | p->delivery_failure = 1; | |
b1153f29 SH |
1012 | } else if (sk_filter(sk, p->skb2)) { |
1013 | kfree_skb(p->skb2); | |
1014 | p->skb2 = NULL; | |
1da177e4 LT |
1015 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { |
1016 | netlink_overrun(sk); | |
be0c22a4 PNA |
1017 | if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) |
1018 | p->delivery_failure = 1; | |
1da177e4 LT |
1019 | } else { |
1020 | p->congested |= val; | |
1021 | p->delivered = 1; | |
1022 | p->skb2 = NULL; | |
1023 | } | |
1024 | sock_put(sk); | |
1025 | ||
1026 | out: | |
1027 | return 0; | |
1028 | } | |
1029 | ||
1030 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 1031 | u32 group, gfp_t allocation) |
1da177e4 | 1032 | { |
3b1e0a65 | 1033 | struct net *net = sock_net(ssk); |
1da177e4 LT |
1034 | struct netlink_broadcast_data info; |
1035 | struct hlist_node *node; | |
1036 | struct sock *sk; | |
1037 | ||
1038 | skb = netlink_trim(skb, allocation); | |
1039 | ||
1040 | info.exclude_sk = ssk; | |
b4b51029 | 1041 | info.net = net; |
1da177e4 LT |
1042 | info.pid = pid; |
1043 | info.group = group; | |
1044 | info.failure = 0; | |
ff491a73 | 1045 | info.delivery_failure = 0; |
1da177e4 LT |
1046 | info.congested = 0; |
1047 | info.delivered = 0; | |
1048 | info.allocation = allocation; | |
1049 | info.skb = skb; | |
1050 | info.skb2 = NULL; | |
1051 | ||
1052 | /* While we sleep in clone, do not allow to change socket list */ | |
1053 | ||
1054 | netlink_lock_table(); | |
1055 | ||
1056 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1057 | do_one_broadcast(sk, &info); | |
1058 | ||
aa1c6a6f TC |
1059 | kfree_skb(skb); |
1060 | ||
1da177e4 LT |
1061 | netlink_unlock_table(); |
1062 | ||
91744f65 | 1063 | kfree_skb(info.skb2); |
1da177e4 | 1064 | |
be0c22a4 | 1065 | if (info.delivery_failure) |
ff491a73 PNA |
1066 | return -ENOBUFS; |
1067 | ||
1da177e4 LT |
1068 | if (info.delivered) { |
1069 | if (info.congested && (allocation & __GFP_WAIT)) | |
1070 | yield(); | |
1071 | return 0; | |
1072 | } | |
1da177e4 LT |
1073 | return -ESRCH; |
1074 | } | |
6ac552fd | 1075 | EXPORT_SYMBOL(netlink_broadcast); |
1da177e4 LT |
1076 | |
1077 | struct netlink_set_err_data { | |
1078 | struct sock *exclude_sk; | |
1079 | u32 pid; | |
1080 | u32 group; | |
1081 | int code; | |
1082 | }; | |
1083 | ||
1084 | static inline int do_one_set_err(struct sock *sk, | |
1085 | struct netlink_set_err_data *p) | |
1086 | { | |
1087 | struct netlink_sock *nlk = nlk_sk(sk); | |
1088 | ||
1089 | if (sk == p->exclude_sk) | |
1090 | goto out; | |
1091 | ||
3b1e0a65 | 1092 | if (sock_net(sk) != sock_net(p->exclude_sk)) |
b4b51029 EB |
1093 | goto out; |
1094 | ||
f7fa9b10 PM |
1095 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
1096 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
1097 | goto out; |
1098 | ||
1099 | sk->sk_err = p->code; | |
1100 | sk->sk_error_report(sk); | |
1101 | out: | |
1102 | return 0; | |
1103 | } | |
1104 | ||
4843b93c PNA |
1105 | /** |
1106 | * netlink_set_err - report error to broadcast listeners | |
1107 | * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() | |
1108 | * @pid: the PID of a process that we want to skip (if any) | |
1109 | * @groups: the broadcast group that will notice the error | |
1110 | * @code: error code, must be negative (as usual in kernelspace) | |
1111 | */ | |
1da177e4 LT |
1112 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) |
1113 | { | |
1114 | struct netlink_set_err_data info; | |
1115 | struct hlist_node *node; | |
1116 | struct sock *sk; | |
1117 | ||
1118 | info.exclude_sk = ssk; | |
1119 | info.pid = pid; | |
1120 | info.group = group; | |
4843b93c PNA |
1121 | /* sk->sk_err wants a positive error value */ |
1122 | info.code = -code; | |
1da177e4 LT |
1123 | |
1124 | read_lock(&nl_table_lock); | |
1125 | ||
1126 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
1127 | do_one_set_err(sk, &info); | |
1128 | ||
1129 | read_unlock(&nl_table_lock); | |
1130 | } | |
dd5b6ce6 | 1131 | EXPORT_SYMBOL(netlink_set_err); |
1da177e4 | 1132 | |
84659eb5 JB |
1133 | /* must be called with netlink table grabbed */ |
1134 | static void netlink_update_socket_mc(struct netlink_sock *nlk, | |
1135 | unsigned int group, | |
1136 | int is_new) | |
1137 | { | |
1138 | int old, new = !!is_new, subscriptions; | |
1139 | ||
1140 | old = test_bit(group - 1, nlk->groups); | |
1141 | subscriptions = nlk->subscriptions - old + new; | |
1142 | if (new) | |
1143 | __set_bit(group - 1, nlk->groups); | |
1144 | else | |
1145 | __clear_bit(group - 1, nlk->groups); | |
1146 | netlink_update_subscriptions(&nlk->sk, subscriptions); | |
1147 | netlink_update_listeners(&nlk->sk); | |
1148 | } | |
1149 | ||
9a4595bc | 1150 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
746fac4d | 1151 | char __user *optval, int optlen) |
9a4595bc PM |
1152 | { |
1153 | struct sock *sk = sock->sk; | |
1154 | struct netlink_sock *nlk = nlk_sk(sk); | |
eb496534 JB |
1155 | unsigned int val = 0; |
1156 | int err; | |
9a4595bc PM |
1157 | |
1158 | if (level != SOL_NETLINK) | |
1159 | return -ENOPROTOOPT; | |
1160 | ||
1161 | if (optlen >= sizeof(int) && | |
eb496534 | 1162 | get_user(val, (unsigned int __user *)optval)) |
9a4595bc PM |
1163 | return -EFAULT; |
1164 | ||
1165 | switch (optname) { | |
1166 | case NETLINK_PKTINFO: | |
1167 | if (val) | |
1168 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1169 | else | |
1170 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1171 | err = 0; | |
1172 | break; | |
1173 | case NETLINK_ADD_MEMBERSHIP: | |
1174 | case NETLINK_DROP_MEMBERSHIP: { | |
9a4595bc PM |
1175 | if (!netlink_capable(sock, NL_NONROOT_RECV)) |
1176 | return -EPERM; | |
b4ff4f04 JB |
1177 | err = netlink_realloc_groups(sk); |
1178 | if (err) | |
1179 | return err; | |
9a4595bc PM |
1180 | if (!val || val - 1 >= nlk->ngroups) |
1181 | return -EINVAL; | |
1182 | netlink_table_grab(); | |
84659eb5 JB |
1183 | netlink_update_socket_mc(nlk, val, |
1184 | optname == NETLINK_ADD_MEMBERSHIP); | |
9a4595bc PM |
1185 | netlink_table_ungrab(); |
1186 | err = 0; | |
1187 | break; | |
1188 | } | |
be0c22a4 PNA |
1189 | case NETLINK_BROADCAST_ERROR: |
1190 | if (val) | |
1191 | nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; | |
1192 | else | |
1193 | nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; | |
1194 | err = 0; | |
1195 | break; | |
38938bfe PNA |
1196 | case NETLINK_NO_ENOBUFS: |
1197 | if (val) { | |
1198 | nlk->flags |= NETLINK_RECV_NO_ENOBUFS; | |
1199 | clear_bit(0, &nlk->state); | |
1200 | wake_up_interruptible(&nlk->wait); | |
1201 | } else | |
1202 | nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; | |
1203 | err = 0; | |
1204 | break; | |
9a4595bc PM |
1205 | default: |
1206 | err = -ENOPROTOOPT; | |
1207 | } | |
1208 | return err; | |
1209 | } | |
1210 | ||
1211 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
746fac4d | 1212 | char __user *optval, int __user *optlen) |
9a4595bc PM |
1213 | { |
1214 | struct sock *sk = sock->sk; | |
1215 | struct netlink_sock *nlk = nlk_sk(sk); | |
1216 | int len, val, err; | |
1217 | ||
1218 | if (level != SOL_NETLINK) | |
1219 | return -ENOPROTOOPT; | |
1220 | ||
1221 | if (get_user(len, optlen)) | |
1222 | return -EFAULT; | |
1223 | if (len < 0) | |
1224 | return -EINVAL; | |
1225 | ||
1226 | switch (optname) { | |
1227 | case NETLINK_PKTINFO: | |
1228 | if (len < sizeof(int)) | |
1229 | return -EINVAL; | |
1230 | len = sizeof(int); | |
1231 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
a27b58fe HC |
1232 | if (put_user(len, optlen) || |
1233 | put_user(val, optval)) | |
1234 | return -EFAULT; | |
9a4595bc PM |
1235 | err = 0; |
1236 | break; | |
be0c22a4 PNA |
1237 | case NETLINK_BROADCAST_ERROR: |
1238 | if (len < sizeof(int)) | |
1239 | return -EINVAL; | |
1240 | len = sizeof(int); | |
1241 | val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; | |
1242 | if (put_user(len, optlen) || | |
1243 | put_user(val, optval)) | |
1244 | return -EFAULT; | |
1245 | err = 0; | |
1246 | break; | |
38938bfe PNA |
1247 | case NETLINK_NO_ENOBUFS: |
1248 | if (len < sizeof(int)) | |
1249 | return -EINVAL; | |
1250 | len = sizeof(int); | |
1251 | val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; | |
1252 | if (put_user(len, optlen) || | |
1253 | put_user(val, optval)) | |
1254 | return -EFAULT; | |
1255 | err = 0; | |
1256 | break; | |
9a4595bc PM |
1257 | default: |
1258 | err = -ENOPROTOOPT; | |
1259 | } | |
1260 | return err; | |
1261 | } | |
1262 | ||
1263 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1264 | { | |
1265 | struct nl_pktinfo info; | |
1266 | ||
1267 | info.group = NETLINK_CB(skb).dst_group; | |
1268 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1269 | } | |
1270 | ||
1da177e4 LT |
1271 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, |
1272 | struct msghdr *msg, size_t len) | |
1273 | { | |
1274 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1275 | struct sock *sk = sock->sk; | |
1276 | struct netlink_sock *nlk = nlk_sk(sk); | |
6ac552fd | 1277 | struct sockaddr_nl *addr = msg->msg_name; |
1da177e4 | 1278 | u32 dst_pid; |
d629b836 | 1279 | u32 dst_group; |
1da177e4 LT |
1280 | struct sk_buff *skb; |
1281 | int err; | |
1282 | struct scm_cookie scm; | |
1283 | ||
1284 | if (msg->msg_flags&MSG_OOB) | |
1285 | return -EOPNOTSUPP; | |
1286 | ||
1287 | if (NULL == siocb->scm) | |
1288 | siocb->scm = &scm; | |
1289 | err = scm_send(sock, msg, siocb->scm); | |
1290 | if (err < 0) | |
1291 | return err; | |
1292 | ||
1293 | if (msg->msg_namelen) { | |
1294 | if (addr->nl_family != AF_NETLINK) | |
1295 | return -EINVAL; | |
1296 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1297 | dst_group = ffs(addr->nl_groups); |
1298 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1299 | return -EPERM; |
1300 | } else { | |
1301 | dst_pid = nlk->dst_pid; | |
d629b836 | 1302 | dst_group = nlk->dst_group; |
1da177e4 LT |
1303 | } |
1304 | ||
1305 | if (!nlk->pid) { | |
1306 | err = netlink_autobind(sock); | |
1307 | if (err) | |
1308 | goto out; | |
1309 | } | |
1310 | ||
1311 | err = -EMSGSIZE; | |
1312 | if (len > sk->sk_sndbuf - 32) | |
1313 | goto out; | |
1314 | err = -ENOBUFS; | |
339bf98f | 1315 | skb = alloc_skb(len, GFP_KERNEL); |
6ac552fd | 1316 | if (skb == NULL) |
1da177e4 LT |
1317 | goto out; |
1318 | ||
1319 | NETLINK_CB(skb).pid = nlk->pid; | |
d629b836 | 1320 | NETLINK_CB(skb).dst_group = dst_group; |
0c11b942 | 1321 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current); |
2532386f | 1322 | NETLINK_CB(skb).sessionid = audit_get_sessionid(current); |
0ce784ca | 1323 | security_task_getsecid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1324 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1325 | ||
1326 | /* What can I do? Netlink is asynchronous, so that | |
1327 | we will have to save current capabilities to | |
1328 | check them, when this message will be delivered | |
1329 | to corresponding kernel module. --ANK (980802) | |
1330 | */ | |
1331 | ||
1332 | err = -EFAULT; | |
6ac552fd | 1333 | if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { |
1da177e4 LT |
1334 | kfree_skb(skb); |
1335 | goto out; | |
1336 | } | |
1337 | ||
1338 | err = security_netlink_send(sk, skb); | |
1339 | if (err) { | |
1340 | kfree_skb(skb); | |
1341 | goto out; | |
1342 | } | |
1343 | ||
d629b836 | 1344 | if (dst_group) { |
1da177e4 | 1345 | atomic_inc(&skb->users); |
d629b836 | 1346 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1347 | } |
1348 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1349 | ||
1350 | out: | |
1351 | return err; | |
1352 | } | |
1353 | ||
1354 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1355 | struct msghdr *msg, size_t len, | |
1356 | int flags) | |
1357 | { | |
1358 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1359 | struct scm_cookie scm; | |
1360 | struct sock *sk = sock->sk; | |
1361 | struct netlink_sock *nlk = nlk_sk(sk); | |
1362 | int noblock = flags&MSG_DONTWAIT; | |
1363 | size_t copied; | |
1dacc76d | 1364 | struct sk_buff *skb, *frag __maybe_unused = NULL; |
1da177e4 LT |
1365 | int err; |
1366 | ||
1367 | if (flags&MSG_OOB) | |
1368 | return -EOPNOTSUPP; | |
1369 | ||
1370 | copied = 0; | |
1371 | ||
6ac552fd PM |
1372 | skb = skb_recv_datagram(sk, flags, noblock, &err); |
1373 | if (skb == NULL) | |
1da177e4 LT |
1374 | goto out; |
1375 | ||
1dacc76d JB |
1376 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES |
1377 | if (unlikely(skb_shinfo(skb)->frag_list)) { | |
1378 | bool need_compat = !!(flags & MSG_CMSG_COMPAT); | |
1379 | ||
1380 | /* | |
1381 | * If this skb has a frag_list, then here that means that | |
1382 | * we will have to use the frag_list skb for compat tasks | |
1383 | * and the regular skb for non-compat tasks. | |
1384 | * | |
1385 | * The skb might (and likely will) be cloned, so we can't | |
1386 | * just reset frag_list and go on with things -- we need to | |
1387 | * keep that. For the compat case that's easy -- simply get | |
1388 | * a reference to the compat skb and free the regular one | |
1389 | * including the frag. For the non-compat case, we need to | |
1390 | * avoid sending the frag to the user -- so assign NULL but | |
1391 | * restore it below before freeing the skb. | |
1392 | */ | |
1393 | if (need_compat) { | |
1394 | struct sk_buff *compskb = skb_shinfo(skb)->frag_list; | |
1395 | skb_get(compskb); | |
1396 | kfree_skb(skb); | |
1397 | skb = compskb; | |
1398 | } else { | |
1399 | frag = skb_shinfo(skb)->frag_list; | |
1400 | skb_shinfo(skb)->frag_list = NULL; | |
1401 | } | |
1402 | } | |
1403 | #endif | |
1404 | ||
1da177e4 LT |
1405 | msg->msg_namelen = 0; |
1406 | ||
1407 | copied = skb->len; | |
1408 | if (len < copied) { | |
1409 | msg->msg_flags |= MSG_TRUNC; | |
1410 | copied = len; | |
1411 | } | |
1412 | ||
badff6d0 | 1413 | skb_reset_transport_header(skb); |
1da177e4 LT |
1414 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); |
1415 | ||
1416 | if (msg->msg_name) { | |
6ac552fd | 1417 | struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; |
1da177e4 LT |
1418 | addr->nl_family = AF_NETLINK; |
1419 | addr->nl_pad = 0; | |
1420 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1421 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1422 | msg->msg_namelen = sizeof(*addr); |
1423 | } | |
1424 | ||
cc9a06cd PM |
1425 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1426 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1427 | ||
1da177e4 LT |
1428 | if (NULL == siocb->scm) { |
1429 | memset(&scm, 0, sizeof(scm)); | |
1430 | siocb->scm = &scm; | |
1431 | } | |
1432 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
188ccb55 PM |
1433 | if (flags & MSG_TRUNC) |
1434 | copied = skb->len; | |
1dacc76d JB |
1435 | |
1436 | #ifdef CONFIG_COMPAT_NETLINK_MESSAGES | |
1437 | skb_shinfo(skb)->frag_list = frag; | |
1438 | #endif | |
1439 | ||
1da177e4 LT |
1440 | skb_free_datagram(sk, skb); |
1441 | ||
1442 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1443 | netlink_dump(sk); | |
1444 | ||
1445 | scm_recv(sock, msg, siocb->scm, flags); | |
1da177e4 LT |
1446 | out: |
1447 | netlink_rcv_wake(sk); | |
1448 | return err ? : copied; | |
1449 | } | |
1450 | ||
1451 | static void netlink_data_ready(struct sock *sk, int len) | |
1452 | { | |
cd40b7d3 | 1453 | BUG(); |
1da177e4 LT |
1454 | } |
1455 | ||
1456 | /* | |
746fac4d | 1457 | * We export these functions to other modules. They provide a |
1da177e4 LT |
1458 | * complete set of kernel non-blocking support for message |
1459 | * queueing. | |
1460 | */ | |
1461 | ||
1462 | struct sock * | |
b4b51029 | 1463 | netlink_kernel_create(struct net *net, int unit, unsigned int groups, |
cd40b7d3 | 1464 | void (*input)(struct sk_buff *skb), |
af65bdfc | 1465 | struct mutex *cb_mutex, struct module *module) |
1da177e4 LT |
1466 | { |
1467 | struct socket *sock; | |
1468 | struct sock *sk; | |
77247bbb | 1469 | struct netlink_sock *nlk; |
4277a083 | 1470 | unsigned long *listeners = NULL; |
1da177e4 | 1471 | |
fab2caf6 | 1472 | BUG_ON(!nl_table); |
1da177e4 | 1473 | |
6ac552fd | 1474 | if (unit < 0 || unit >= MAX_LINKS) |
1da177e4 LT |
1475 | return NULL; |
1476 | ||
1477 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1478 | return NULL; | |
1479 | ||
23fe1866 PE |
1480 | /* |
1481 | * We have to just have a reference on the net from sk, but don't | |
1482 | * get_net it. Besides, we cannot get and then put the net here. | |
1483 | * So we create one inside init_net and the move it to net. | |
1484 | */ | |
1485 | ||
1486 | if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) | |
1487 | goto out_sock_release_nosk; | |
1488 | ||
1489 | sk = sock->sk; | |
edf02087 | 1490 | sk_change_net(sk, net); |
4fdb3bb7 | 1491 | |
4277a083 PM |
1492 | if (groups < 32) |
1493 | groups = 32; | |
1494 | ||
6c04bb18 JB |
1495 | listeners = kzalloc(NLGRPSZ(groups) + sizeof(struct listeners_rcu_head), |
1496 | GFP_KERNEL); | |
4277a083 PM |
1497 | if (!listeners) |
1498 | goto out_sock_release; | |
1499 | ||
1da177e4 LT |
1500 | sk->sk_data_ready = netlink_data_ready; |
1501 | if (input) | |
cd40b7d3 | 1502 | nlk_sk(sk)->netlink_rcv = input; |
1da177e4 | 1503 | |
b4b51029 | 1504 | if (netlink_insert(sk, net, 0)) |
77247bbb | 1505 | goto out_sock_release; |
4fdb3bb7 | 1506 | |
77247bbb PM |
1507 | nlk = nlk_sk(sk); |
1508 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1509 | |
4fdb3bb7 | 1510 | netlink_table_grab(); |
b4b51029 EB |
1511 | if (!nl_table[unit].registered) { |
1512 | nl_table[unit].groups = groups; | |
1513 | nl_table[unit].listeners = listeners; | |
1514 | nl_table[unit].cb_mutex = cb_mutex; | |
1515 | nl_table[unit].module = module; | |
1516 | nl_table[unit].registered = 1; | |
f937f1f4 JJ |
1517 | } else { |
1518 | kfree(listeners); | |
869e58f8 | 1519 | nl_table[unit].registered++; |
b4b51029 | 1520 | } |
4fdb3bb7 | 1521 | netlink_table_ungrab(); |
77247bbb PM |
1522 | return sk; |
1523 | ||
4fdb3bb7 | 1524 | out_sock_release: |
4277a083 | 1525 | kfree(listeners); |
9dfbec1f | 1526 | netlink_kernel_release(sk); |
23fe1866 PE |
1527 | return NULL; |
1528 | ||
1529 | out_sock_release_nosk: | |
4fdb3bb7 | 1530 | sock_release(sock); |
77247bbb | 1531 | return NULL; |
1da177e4 | 1532 | } |
6ac552fd | 1533 | EXPORT_SYMBOL(netlink_kernel_create); |
1da177e4 | 1534 | |
b7c6ba6e DL |
1535 | |
1536 | void | |
1537 | netlink_kernel_release(struct sock *sk) | |
1538 | { | |
edf02087 | 1539 | sk_release_kernel(sk); |
b7c6ba6e DL |
1540 | } |
1541 | EXPORT_SYMBOL(netlink_kernel_release); | |
1542 | ||
1543 | ||
6c04bb18 JB |
1544 | static void netlink_free_old_listeners(struct rcu_head *rcu_head) |
1545 | { | |
1546 | struct listeners_rcu_head *lrh; | |
1547 | ||
1548 | lrh = container_of(rcu_head, struct listeners_rcu_head, rcu_head); | |
1549 | kfree(lrh->ptr); | |
1550 | } | |
1551 | ||
b4ff4f04 JB |
1552 | /** |
1553 | * netlink_change_ngroups - change number of multicast groups | |
1554 | * | |
1555 | * This changes the number of multicast groups that are available | |
1556 | * on a certain netlink family. Note that it is not possible to | |
84659eb5 JB |
1557 | * change the number of groups to below 32. Also note that it does |
1558 | * not implicitly call netlink_clear_multicast_users() when the | |
1559 | * number of groups is reduced. | |
b4ff4f04 JB |
1560 | * |
1561 | * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). | |
1562 | * @groups: The new number of groups. | |
1563 | */ | |
1564 | int netlink_change_ngroups(struct sock *sk, unsigned int groups) | |
1565 | { | |
1566 | unsigned long *listeners, *old = NULL; | |
6c04bb18 | 1567 | struct listeners_rcu_head *old_rcu_head; |
b4ff4f04 JB |
1568 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; |
1569 | int err = 0; | |
1570 | ||
1571 | if (groups < 32) | |
1572 | groups = 32; | |
1573 | ||
1574 | netlink_table_grab(); | |
1575 | if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { | |
6c04bb18 JB |
1576 | listeners = kzalloc(NLGRPSZ(groups) + |
1577 | sizeof(struct listeners_rcu_head), | |
1578 | GFP_ATOMIC); | |
b4ff4f04 JB |
1579 | if (!listeners) { |
1580 | err = -ENOMEM; | |
1581 | goto out_ungrab; | |
1582 | } | |
1583 | old = tbl->listeners; | |
1584 | memcpy(listeners, old, NLGRPSZ(tbl->groups)); | |
1585 | rcu_assign_pointer(tbl->listeners, listeners); | |
6c04bb18 JB |
1586 | /* |
1587 | * Free the old memory after an RCU grace period so we | |
1588 | * don't leak it. We use call_rcu() here in order to be | |
1589 | * able to call this function from atomic contexts. The | |
1590 | * allocation of this memory will have reserved enough | |
1591 | * space for struct listeners_rcu_head at the end. | |
1592 | */ | |
1593 | old_rcu_head = (void *)(tbl->listeners + | |
1594 | NLGRPLONGS(tbl->groups)); | |
1595 | old_rcu_head->ptr = old; | |
1596 | call_rcu(&old_rcu_head->rcu_head, netlink_free_old_listeners); | |
b4ff4f04 JB |
1597 | } |
1598 | tbl->groups = groups; | |
1599 | ||
1600 | out_ungrab: | |
1601 | netlink_table_ungrab(); | |
b4ff4f04 JB |
1602 | return err; |
1603 | } | |
b4ff4f04 | 1604 | |
84659eb5 JB |
1605 | /** |
1606 | * netlink_clear_multicast_users - kick off multicast listeners | |
1607 | * | |
1608 | * This function removes all listeners from the given group. | |
1609 | * @ksk: The kernel netlink socket, as returned by | |
1610 | * netlink_kernel_create(). | |
1611 | * @group: The multicast group to clear. | |
1612 | */ | |
1613 | void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) | |
1614 | { | |
1615 | struct sock *sk; | |
1616 | struct hlist_node *node; | |
1617 | struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; | |
1618 | ||
1619 | netlink_table_grab(); | |
1620 | ||
1621 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
1622 | netlink_update_socket_mc(nlk_sk(sk), group, 0); | |
1623 | ||
1624 | netlink_table_ungrab(); | |
1625 | } | |
84659eb5 | 1626 | |
1da177e4 | 1627 | void netlink_set_nonroot(int protocol, unsigned int flags) |
746fac4d YH |
1628 | { |
1629 | if ((unsigned int)protocol < MAX_LINKS) | |
1da177e4 | 1630 | nl_table[protocol].nl_nonroot = flags; |
746fac4d | 1631 | } |
6ac552fd | 1632 | EXPORT_SYMBOL(netlink_set_nonroot); |
1da177e4 LT |
1633 | |
1634 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1635 | { | |
91744f65 | 1636 | kfree_skb(cb->skb); |
1da177e4 LT |
1637 | kfree(cb); |
1638 | } | |
1639 | ||
1640 | /* | |
1641 | * It looks a bit ugly. | |
1642 | * It would be better to create kernel thread. | |
1643 | */ | |
1644 | ||
1645 | static int netlink_dump(struct sock *sk) | |
1646 | { | |
1647 | struct netlink_sock *nlk = nlk_sk(sk); | |
1648 | struct netlink_callback *cb; | |
1649 | struct sk_buff *skb; | |
1650 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1651 | int len, err = -ENOBUFS; |
746fac4d | 1652 | |
1da177e4 LT |
1653 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); |
1654 | if (!skb) | |
bf8b79e4 | 1655 | goto errout; |
1da177e4 | 1656 | |
af65bdfc | 1657 | mutex_lock(nlk->cb_mutex); |
1da177e4 LT |
1658 | |
1659 | cb = nlk->cb; | |
1660 | if (cb == NULL) { | |
bf8b79e4 TG |
1661 | err = -EINVAL; |
1662 | goto errout_skb; | |
1da177e4 LT |
1663 | } |
1664 | ||
1665 | len = cb->dump(skb, cb); | |
1666 | ||
1667 | if (len > 0) { | |
af65bdfc | 1668 | mutex_unlock(nlk->cb_mutex); |
b1153f29 SH |
1669 | |
1670 | if (sk_filter(sk, skb)) | |
1671 | kfree_skb(skb); | |
1672 | else { | |
1673 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1674 | sk->sk_data_ready(sk, skb->len); | |
1675 | } | |
1da177e4 LT |
1676 | return 0; |
1677 | } | |
1678 | ||
bf8b79e4 TG |
1679 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1680 | if (!nlh) | |
1681 | goto errout_skb; | |
1682 | ||
1683 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1684 | ||
b1153f29 SH |
1685 | if (sk_filter(sk, skb)) |
1686 | kfree_skb(skb); | |
1687 | else { | |
1688 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1689 | sk->sk_data_ready(sk, skb->len); | |
1690 | } | |
1da177e4 | 1691 | |
a8f74b22 TG |
1692 | if (cb->done) |
1693 | cb->done(cb); | |
1da177e4 | 1694 | nlk->cb = NULL; |
af65bdfc | 1695 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1696 | |
1697 | netlink_destroy_callback(cb); | |
1da177e4 | 1698 | return 0; |
1797754e | 1699 | |
bf8b79e4 | 1700 | errout_skb: |
af65bdfc | 1701 | mutex_unlock(nlk->cb_mutex); |
bf8b79e4 TG |
1702 | kfree_skb(skb); |
1703 | errout: | |
1704 | return err; | |
1da177e4 LT |
1705 | } |
1706 | ||
1707 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1708 | struct nlmsghdr *nlh, | |
6ac552fd PM |
1709 | int (*dump)(struct sk_buff *skb, |
1710 | struct netlink_callback *), | |
1711 | int (*done)(struct netlink_callback *)) | |
1da177e4 LT |
1712 | { |
1713 | struct netlink_callback *cb; | |
1714 | struct sock *sk; | |
1715 | struct netlink_sock *nlk; | |
1716 | ||
0da974f4 | 1717 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1718 | if (cb == NULL) |
1719 | return -ENOBUFS; | |
1720 | ||
1da177e4 LT |
1721 | cb->dump = dump; |
1722 | cb->done = done; | |
1723 | cb->nlh = nlh; | |
1724 | atomic_inc(&skb->users); | |
1725 | cb->skb = skb; | |
1726 | ||
3b1e0a65 | 1727 | sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); |
1da177e4 LT |
1728 | if (sk == NULL) { |
1729 | netlink_destroy_callback(cb); | |
1730 | return -ECONNREFUSED; | |
1731 | } | |
1732 | nlk = nlk_sk(sk); | |
3f660d66 | 1733 | /* A dump is in progress... */ |
af65bdfc | 1734 | mutex_lock(nlk->cb_mutex); |
3f660d66 | 1735 | if (nlk->cb) { |
af65bdfc | 1736 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1737 | netlink_destroy_callback(cb); |
1738 | sock_put(sk); | |
1739 | return -EBUSY; | |
1740 | } | |
1741 | nlk->cb = cb; | |
af65bdfc | 1742 | mutex_unlock(nlk->cb_mutex); |
1da177e4 LT |
1743 | |
1744 | netlink_dump(sk); | |
1745 | sock_put(sk); | |
5c58298c DL |
1746 | |
1747 | /* We successfully started a dump, by returning -EINTR we | |
1748 | * signal not to send ACK even if it was requested. | |
1749 | */ | |
1750 | return -EINTR; | |
1da177e4 | 1751 | } |
6ac552fd | 1752 | EXPORT_SYMBOL(netlink_dump_start); |
1da177e4 LT |
1753 | |
1754 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1755 | { | |
1756 | struct sk_buff *skb; | |
1757 | struct nlmsghdr *rep; | |
1758 | struct nlmsgerr *errmsg; | |
339bf98f | 1759 | size_t payload = sizeof(*errmsg); |
1da177e4 | 1760 | |
339bf98f TG |
1761 | /* error messages get the original request appened */ |
1762 | if (err) | |
1763 | payload += nlmsg_len(nlh); | |
1da177e4 | 1764 | |
339bf98f | 1765 | skb = nlmsg_new(payload, GFP_KERNEL); |
1da177e4 LT |
1766 | if (!skb) { |
1767 | struct sock *sk; | |
1768 | ||
3b1e0a65 | 1769 | sk = netlink_lookup(sock_net(in_skb->sk), |
b4b51029 | 1770 | in_skb->sk->sk_protocol, |
1da177e4 LT |
1771 | NETLINK_CB(in_skb).pid); |
1772 | if (sk) { | |
1773 | sk->sk_err = ENOBUFS; | |
1774 | sk->sk_error_report(sk); | |
1775 | sock_put(sk); | |
1776 | } | |
1777 | return; | |
1778 | } | |
1779 | ||
1780 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1781 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1782 | errmsg = nlmsg_data(rep); |
1da177e4 | 1783 | errmsg->error = err; |
bf8b79e4 | 1784 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1785 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1786 | } | |
6ac552fd | 1787 | EXPORT_SYMBOL(netlink_ack); |
1da177e4 | 1788 | |
cd40b7d3 | 1789 | int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1d00a4eb | 1790 | struct nlmsghdr *)) |
82ace47a | 1791 | { |
82ace47a TG |
1792 | struct nlmsghdr *nlh; |
1793 | int err; | |
1794 | ||
1795 | while (skb->len >= nlmsg_total_size(0)) { | |
cd40b7d3 DL |
1796 | int msglen; |
1797 | ||
b529ccf2 | 1798 | nlh = nlmsg_hdr(skb); |
d35b6856 | 1799 | err = 0; |
82ace47a | 1800 | |
ad8e4b75 | 1801 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1802 | return 0; |
1803 | ||
d35b6856 TG |
1804 | /* Only requests are handled by the kernel */ |
1805 | if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) | |
5c58298c | 1806 | goto ack; |
45e7ae7f TG |
1807 | |
1808 | /* Skip control messages */ | |
1809 | if (nlh->nlmsg_type < NLMSG_MIN_TYPE) | |
5c58298c | 1810 | goto ack; |
d35b6856 | 1811 | |
1d00a4eb | 1812 | err = cb(skb, nlh); |
5c58298c DL |
1813 | if (err == -EINTR) |
1814 | goto skip; | |
1815 | ||
1816 | ack: | |
d35b6856 | 1817 | if (nlh->nlmsg_flags & NLM_F_ACK || err) |
82ace47a | 1818 | netlink_ack(skb, nlh, err); |
82ace47a | 1819 | |
5c58298c | 1820 | skip: |
6ac552fd | 1821 | msglen = NLMSG_ALIGN(nlh->nlmsg_len); |
cd40b7d3 DL |
1822 | if (msglen > skb->len) |
1823 | msglen = skb->len; | |
1824 | skb_pull(skb, msglen); | |
82ace47a TG |
1825 | } |
1826 | ||
1827 | return 0; | |
1828 | } | |
6ac552fd | 1829 | EXPORT_SYMBOL(netlink_rcv_skb); |
82ace47a | 1830 | |
d387f6ad TG |
1831 | /** |
1832 | * nlmsg_notify - send a notification netlink message | |
1833 | * @sk: netlink socket to use | |
1834 | * @skb: notification message | |
1835 | * @pid: destination netlink pid for reports or 0 | |
1836 | * @group: destination multicast group or 0 | |
1837 | * @report: 1 to report back, 0 to disable | |
1838 | * @flags: allocation flags | |
1839 | */ | |
1840 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1841 | unsigned int group, int report, gfp_t flags) | |
1842 | { | |
1843 | int err = 0; | |
1844 | ||
1845 | if (group) { | |
1846 | int exclude_pid = 0; | |
1847 | ||
1848 | if (report) { | |
1849 | atomic_inc(&skb->users); | |
1850 | exclude_pid = pid; | |
1851 | } | |
1852 | ||
1ce85fe4 PNA |
1853 | /* errors reported via destination sk->sk_err, but propagate |
1854 | * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ | |
1855 | err = nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
d387f6ad TG |
1856 | } |
1857 | ||
1ce85fe4 PNA |
1858 | if (report) { |
1859 | int err2; | |
1860 | ||
1861 | err2 = nlmsg_unicast(sk, skb, pid); | |
1862 | if (!err || err == -ESRCH) | |
1863 | err = err2; | |
1864 | } | |
d387f6ad TG |
1865 | |
1866 | return err; | |
1867 | } | |
6ac552fd | 1868 | EXPORT_SYMBOL(nlmsg_notify); |
d387f6ad | 1869 | |
1da177e4 LT |
1870 | #ifdef CONFIG_PROC_FS |
1871 | struct nl_seq_iter { | |
e372c414 | 1872 | struct seq_net_private p; |
1da177e4 LT |
1873 | int link; |
1874 | int hash_idx; | |
1875 | }; | |
1876 | ||
1877 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1878 | { | |
1879 | struct nl_seq_iter *iter = seq->private; | |
1880 | int i, j; | |
1881 | struct sock *s; | |
1882 | struct hlist_node *node; | |
1883 | loff_t off = 0; | |
1884 | ||
6ac552fd | 1885 | for (i = 0; i < MAX_LINKS; i++) { |
1da177e4 LT |
1886 | struct nl_pid_hash *hash = &nl_table[i].hash; |
1887 | ||
1888 | for (j = 0; j <= hash->mask; j++) { | |
1889 | sk_for_each(s, node, &hash->table[j]) { | |
1218854a | 1890 | if (sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1891 | continue; |
1da177e4 LT |
1892 | if (off == pos) { |
1893 | iter->link = i; | |
1894 | iter->hash_idx = j; | |
1895 | return s; | |
1896 | } | |
1897 | ++off; | |
1898 | } | |
1899 | } | |
1900 | } | |
1901 | return NULL; | |
1902 | } | |
1903 | ||
1904 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
9a429c49 | 1905 | __acquires(nl_table_lock) |
1da177e4 LT |
1906 | { |
1907 | read_lock(&nl_table_lock); | |
1908 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1909 | } | |
1910 | ||
1911 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1912 | { | |
1913 | struct sock *s; | |
1914 | struct nl_seq_iter *iter; | |
1915 | int i, j; | |
1916 | ||
1917 | ++*pos; | |
1918 | ||
1919 | if (v == SEQ_START_TOKEN) | |
1920 | return netlink_seq_socket_idx(seq, 0); | |
746fac4d | 1921 | |
b4b51029 EB |
1922 | iter = seq->private; |
1923 | s = v; | |
1924 | do { | |
1925 | s = sk_next(s); | |
1218854a | 1926 | } while (s && sock_net(s) != seq_file_net(seq)); |
1da177e4 LT |
1927 | if (s) |
1928 | return s; | |
1929 | ||
1da177e4 LT |
1930 | i = iter->link; |
1931 | j = iter->hash_idx + 1; | |
1932 | ||
1933 | do { | |
1934 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1935 | ||
1936 | for (; j <= hash->mask; j++) { | |
1937 | s = sk_head(&hash->table[j]); | |
1218854a | 1938 | while (s && sock_net(s) != seq_file_net(seq)) |
b4b51029 | 1939 | s = sk_next(s); |
1da177e4 LT |
1940 | if (s) { |
1941 | iter->link = i; | |
1942 | iter->hash_idx = j; | |
1943 | return s; | |
1944 | } | |
1945 | } | |
1946 | ||
1947 | j = 0; | |
1948 | } while (++i < MAX_LINKS); | |
1949 | ||
1950 | return NULL; | |
1951 | } | |
1952 | ||
1953 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
9a429c49 | 1954 | __releases(nl_table_lock) |
1da177e4 LT |
1955 | { |
1956 | read_unlock(&nl_table_lock); | |
1957 | } | |
1958 | ||
1959 | ||
1960 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1961 | { | |
1962 | if (v == SEQ_START_TOKEN) | |
1963 | seq_puts(seq, | |
1964 | "sk Eth Pid Groups " | |
38938bfe | 1965 | "Rmem Wmem Dump Locks Drops\n"); |
1da177e4 LT |
1966 | else { |
1967 | struct sock *s = v; | |
1968 | struct netlink_sock *nlk = nlk_sk(s); | |
1969 | ||
38938bfe | 1970 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %-8d %-8d\n", |
1da177e4 LT |
1971 | s, |
1972 | s->sk_protocol, | |
1973 | nlk->pid, | |
513c2500 | 1974 | nlk->groups ? (u32)nlk->groups[0] : 0, |
31e6d363 ED |
1975 | sk_rmem_alloc_get(s), |
1976 | sk_wmem_alloc_get(s), | |
1da177e4 | 1977 | nlk->cb, |
38938bfe PNA |
1978 | atomic_read(&s->sk_refcnt), |
1979 | atomic_read(&s->sk_drops) | |
1da177e4 LT |
1980 | ); |
1981 | ||
1982 | } | |
1983 | return 0; | |
1984 | } | |
1985 | ||
56b3d975 | 1986 | static const struct seq_operations netlink_seq_ops = { |
1da177e4 LT |
1987 | .start = netlink_seq_start, |
1988 | .next = netlink_seq_next, | |
1989 | .stop = netlink_seq_stop, | |
1990 | .show = netlink_seq_show, | |
1991 | }; | |
1992 | ||
1993 | ||
1994 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1995 | { | |
e372c414 DL |
1996 | return seq_open_net(inode, file, &netlink_seq_ops, |
1997 | sizeof(struct nl_seq_iter)); | |
b4b51029 EB |
1998 | } |
1999 | ||
da7071d7 | 2000 | static const struct file_operations netlink_seq_fops = { |
1da177e4 LT |
2001 | .owner = THIS_MODULE, |
2002 | .open = netlink_seq_open, | |
2003 | .read = seq_read, | |
2004 | .llseek = seq_lseek, | |
e372c414 | 2005 | .release = seq_release_net, |
1da177e4 LT |
2006 | }; |
2007 | ||
2008 | #endif | |
2009 | ||
2010 | int netlink_register_notifier(struct notifier_block *nb) | |
2011 | { | |
e041c683 | 2012 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 | 2013 | } |
6ac552fd | 2014 | EXPORT_SYMBOL(netlink_register_notifier); |
1da177e4 LT |
2015 | |
2016 | int netlink_unregister_notifier(struct notifier_block *nb) | |
2017 | { | |
e041c683 | 2018 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 | 2019 | } |
6ac552fd | 2020 | EXPORT_SYMBOL(netlink_unregister_notifier); |
746fac4d | 2021 | |
90ddc4f0 | 2022 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
2023 | .family = PF_NETLINK, |
2024 | .owner = THIS_MODULE, | |
2025 | .release = netlink_release, | |
2026 | .bind = netlink_bind, | |
2027 | .connect = netlink_connect, | |
2028 | .socketpair = sock_no_socketpair, | |
2029 | .accept = sock_no_accept, | |
2030 | .getname = netlink_getname, | |
2031 | .poll = datagram_poll, | |
2032 | .ioctl = sock_no_ioctl, | |
2033 | .listen = sock_no_listen, | |
2034 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
2035 | .setsockopt = netlink_setsockopt, |
2036 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
2037 | .sendmsg = netlink_sendmsg, |
2038 | .recvmsg = netlink_recvmsg, | |
2039 | .mmap = sock_no_mmap, | |
2040 | .sendpage = sock_no_sendpage, | |
2041 | }; | |
2042 | ||
2043 | static struct net_proto_family netlink_family_ops = { | |
2044 | .family = PF_NETLINK, | |
2045 | .create = netlink_create, | |
2046 | .owner = THIS_MODULE, /* for consistency 8) */ | |
2047 | }; | |
2048 | ||
4665079c | 2049 | static int __net_init netlink_net_init(struct net *net) |
b4b51029 EB |
2050 | { |
2051 | #ifdef CONFIG_PROC_FS | |
2052 | if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) | |
2053 | return -ENOMEM; | |
2054 | #endif | |
2055 | return 0; | |
2056 | } | |
2057 | ||
4665079c | 2058 | static void __net_exit netlink_net_exit(struct net *net) |
b4b51029 EB |
2059 | { |
2060 | #ifdef CONFIG_PROC_FS | |
2061 | proc_net_remove(net, "netlink"); | |
2062 | #endif | |
2063 | } | |
2064 | ||
022cbae6 | 2065 | static struct pernet_operations __net_initdata netlink_net_ops = { |
b4b51029 EB |
2066 | .init = netlink_net_init, |
2067 | .exit = netlink_net_exit, | |
2068 | }; | |
2069 | ||
1da177e4 LT |
2070 | static int __init netlink_proto_init(void) |
2071 | { | |
2072 | struct sk_buff *dummy_skb; | |
2073 | int i; | |
26ff5ddc | 2074 | unsigned long limit; |
1da177e4 LT |
2075 | unsigned int order; |
2076 | int err = proto_register(&netlink_proto, 0); | |
2077 | ||
2078 | if (err != 0) | |
2079 | goto out; | |
2080 | ||
ef047f5e | 2081 | BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); |
1da177e4 | 2082 | |
0da974f4 | 2083 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
2084 | if (!nl_table) |
2085 | goto panic; | |
1da177e4 | 2086 | |
1da177e4 | 2087 | if (num_physpages >= (128 * 1024)) |
26ff5ddc | 2088 | limit = num_physpages >> (21 - PAGE_SHIFT); |
1da177e4 | 2089 | else |
26ff5ddc | 2090 | limit = num_physpages >> (23 - PAGE_SHIFT); |
1da177e4 | 2091 | |
26ff5ddc DC |
2092 | order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; |
2093 | limit = (1UL << order) / sizeof(struct hlist_head); | |
2094 | order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; | |
1da177e4 LT |
2095 | |
2096 | for (i = 0; i < MAX_LINKS; i++) { | |
2097 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
2098 | ||
ea72912c | 2099 | hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); |
1da177e4 LT |
2100 | if (!hash->table) { |
2101 | while (i-- > 0) | |
2102 | nl_pid_hash_free(nl_table[i].hash.table, | |
2103 | 1 * sizeof(*hash->table)); | |
2104 | kfree(nl_table); | |
fab2caf6 | 2105 | goto panic; |
1da177e4 | 2106 | } |
1da177e4 LT |
2107 | hash->max_shift = order; |
2108 | hash->shift = 0; | |
2109 | hash->mask = 0; | |
2110 | hash->rehash_time = jiffies; | |
2111 | } | |
2112 | ||
2113 | sock_register(&netlink_family_ops); | |
b4b51029 | 2114 | register_pernet_subsys(&netlink_net_ops); |
746fac4d | 2115 | /* The netlink device handler may be needed early. */ |
1da177e4 LT |
2116 | rtnetlink_init(); |
2117 | out: | |
2118 | return err; | |
fab2caf6 AM |
2119 | panic: |
2120 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
2121 | } |
2122 | ||
1da177e4 | 2123 | core_initcall(netlink_proto_init); |