Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * NETLINK Kernel-user communication protocol. | |
3 | * | |
4 | * Authors: Alan Cox <alan@redhat.com> | |
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. | |
11 | * | |
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> | |
48 | #include <linux/smp_lock.h> | |
49 | #include <linux/notifier.h> | |
50 | #include <linux/security.h> | |
51 | #include <linux/jhash.h> | |
52 | #include <linux/jiffies.h> | |
53 | #include <linux/random.h> | |
54 | #include <linux/bitops.h> | |
55 | #include <linux/mm.h> | |
56 | #include <linux/types.h> | |
54e0f520 | 57 | #include <linux/audit.h> |
e7c34970 | 58 | #include <linux/selinux.h> |
54e0f520 | 59 | |
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) |
1da177e4 LT |
65 | |
66 | struct netlink_sock { | |
67 | /* struct sock has to be the first member of netlink_sock */ | |
68 | struct sock sk; | |
69 | u32 pid; | |
1da177e4 | 70 | u32 dst_pid; |
d629b836 | 71 | u32 dst_group; |
f7fa9b10 PM |
72 | u32 flags; |
73 | u32 subscriptions; | |
74 | u32 ngroups; | |
75 | unsigned long *groups; | |
1da177e4 LT |
76 | unsigned long state; |
77 | wait_queue_head_t wait; | |
78 | struct netlink_callback *cb; | |
79 | spinlock_t cb_lock; | |
80 | void (*data_ready)(struct sock *sk, int bytes); | |
77247bbb | 81 | struct module *module; |
1da177e4 LT |
82 | }; |
83 | ||
77247bbb | 84 | #define NETLINK_KERNEL_SOCKET 0x1 |
9a4595bc | 85 | #define NETLINK_RECV_PKTINFO 0x2 |
77247bbb | 86 | |
1da177e4 LT |
87 | static inline struct netlink_sock *nlk_sk(struct sock *sk) |
88 | { | |
89 | return (struct netlink_sock *)sk; | |
90 | } | |
91 | ||
92 | struct nl_pid_hash { | |
93 | struct hlist_head *table; | |
94 | unsigned long rehash_time; | |
95 | ||
96 | unsigned int mask; | |
97 | unsigned int shift; | |
98 | ||
99 | unsigned int entries; | |
100 | unsigned int max_shift; | |
101 | ||
102 | u32 rnd; | |
103 | }; | |
104 | ||
105 | struct netlink_table { | |
106 | struct nl_pid_hash hash; | |
107 | struct hlist_head mc_list; | |
4277a083 | 108 | unsigned long *listeners; |
1da177e4 | 109 | unsigned int nl_nonroot; |
f7fa9b10 | 110 | unsigned int groups; |
77247bbb | 111 | struct module *module; |
ab33a171 | 112 | int registered; |
1da177e4 LT |
113 | }; |
114 | ||
115 | static struct netlink_table *nl_table; | |
116 | ||
117 | static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); | |
118 | ||
119 | static int netlink_dump(struct sock *sk); | |
120 | static void netlink_destroy_callback(struct netlink_callback *cb); | |
121 | ||
122 | static DEFINE_RWLOCK(nl_table_lock); | |
123 | static atomic_t nl_table_users = ATOMIC_INIT(0); | |
124 | ||
e041c683 | 125 | static ATOMIC_NOTIFIER_HEAD(netlink_chain); |
1da177e4 | 126 | |
d629b836 PM |
127 | static u32 netlink_group_mask(u32 group) |
128 | { | |
129 | return group ? 1 << (group - 1) : 0; | |
130 | } | |
131 | ||
1da177e4 LT |
132 | static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) |
133 | { | |
134 | return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; | |
135 | } | |
136 | ||
137 | static void netlink_sock_destruct(struct sock *sk) | |
138 | { | |
139 | skb_queue_purge(&sk->sk_receive_queue); | |
140 | ||
141 | if (!sock_flag(sk, SOCK_DEAD)) { | |
142 | printk("Freeing alive netlink socket %p\n", sk); | |
143 | return; | |
144 | } | |
145 | BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); | |
146 | BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); | |
147 | BUG_TRAP(!nlk_sk(sk)->cb); | |
f7fa9b10 | 148 | BUG_TRAP(!nlk_sk(sk)->groups); |
1da177e4 LT |
149 | } |
150 | ||
151 | /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP. | |
152 | * Look, when several writers sleep and reader wakes them up, all but one | |
153 | * immediately hit write lock and grab all the cpus. Exclusive sleep solves | |
154 | * this, _but_ remember, it adds useless work on UP machines. | |
155 | */ | |
156 | ||
157 | static void netlink_table_grab(void) | |
158 | { | |
6abd219c | 159 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
160 | |
161 | if (atomic_read(&nl_table_users)) { | |
162 | DECLARE_WAITQUEUE(wait, current); | |
163 | ||
164 | add_wait_queue_exclusive(&nl_table_wait, &wait); | |
165 | for(;;) { | |
166 | set_current_state(TASK_UNINTERRUPTIBLE); | |
167 | if (atomic_read(&nl_table_users) == 0) | |
168 | break; | |
6abd219c | 169 | write_unlock_irq(&nl_table_lock); |
1da177e4 | 170 | schedule(); |
6abd219c | 171 | write_lock_irq(&nl_table_lock); |
1da177e4 LT |
172 | } |
173 | ||
174 | __set_current_state(TASK_RUNNING); | |
175 | remove_wait_queue(&nl_table_wait, &wait); | |
176 | } | |
177 | } | |
178 | ||
179 | static __inline__ void netlink_table_ungrab(void) | |
180 | { | |
6abd219c | 181 | write_unlock_irq(&nl_table_lock); |
1da177e4 LT |
182 | wake_up(&nl_table_wait); |
183 | } | |
184 | ||
185 | static __inline__ void | |
186 | netlink_lock_table(void) | |
187 | { | |
188 | /* read_lock() synchronizes us to netlink_table_grab */ | |
189 | ||
190 | read_lock(&nl_table_lock); | |
191 | atomic_inc(&nl_table_users); | |
192 | read_unlock(&nl_table_lock); | |
193 | } | |
194 | ||
195 | static __inline__ void | |
196 | netlink_unlock_table(void) | |
197 | { | |
198 | if (atomic_dec_and_test(&nl_table_users)) | |
199 | wake_up(&nl_table_wait); | |
200 | } | |
201 | ||
202 | static __inline__ struct sock *netlink_lookup(int protocol, u32 pid) | |
203 | { | |
204 | struct nl_pid_hash *hash = &nl_table[protocol].hash; | |
205 | struct hlist_head *head; | |
206 | struct sock *sk; | |
207 | struct hlist_node *node; | |
208 | ||
209 | read_lock(&nl_table_lock); | |
210 | head = nl_pid_hashfn(hash, pid); | |
211 | sk_for_each(sk, node, head) { | |
212 | if (nlk_sk(sk)->pid == pid) { | |
213 | sock_hold(sk); | |
214 | goto found; | |
215 | } | |
216 | } | |
217 | sk = NULL; | |
218 | found: | |
219 | read_unlock(&nl_table_lock); | |
220 | return sk; | |
221 | } | |
222 | ||
223 | static inline struct hlist_head *nl_pid_hash_alloc(size_t size) | |
224 | { | |
225 | if (size <= PAGE_SIZE) | |
226 | return kmalloc(size, GFP_ATOMIC); | |
227 | else | |
228 | return (struct hlist_head *) | |
229 | __get_free_pages(GFP_ATOMIC, get_order(size)); | |
230 | } | |
231 | ||
232 | static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) | |
233 | { | |
234 | if (size <= PAGE_SIZE) | |
235 | kfree(table); | |
236 | else | |
237 | free_pages((unsigned long)table, get_order(size)); | |
238 | } | |
239 | ||
240 | static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) | |
241 | { | |
242 | unsigned int omask, mask, shift; | |
243 | size_t osize, size; | |
244 | struct hlist_head *otable, *table; | |
245 | int i; | |
246 | ||
247 | omask = mask = hash->mask; | |
248 | osize = size = (mask + 1) * sizeof(*table); | |
249 | shift = hash->shift; | |
250 | ||
251 | if (grow) { | |
252 | if (++shift > hash->max_shift) | |
253 | return 0; | |
254 | mask = mask * 2 + 1; | |
255 | size *= 2; | |
256 | } | |
257 | ||
258 | table = nl_pid_hash_alloc(size); | |
259 | if (!table) | |
260 | return 0; | |
261 | ||
262 | memset(table, 0, size); | |
263 | otable = hash->table; | |
264 | hash->table = table; | |
265 | hash->mask = mask; | |
266 | hash->shift = shift; | |
267 | get_random_bytes(&hash->rnd, sizeof(hash->rnd)); | |
268 | ||
269 | for (i = 0; i <= omask; i++) { | |
270 | struct sock *sk; | |
271 | struct hlist_node *node, *tmp; | |
272 | ||
273 | sk_for_each_safe(sk, node, tmp, &otable[i]) | |
274 | __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); | |
275 | } | |
276 | ||
277 | nl_pid_hash_free(otable, osize); | |
278 | hash->rehash_time = jiffies + 10 * 60 * HZ; | |
279 | return 1; | |
280 | } | |
281 | ||
282 | static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) | |
283 | { | |
284 | int avg = hash->entries >> hash->shift; | |
285 | ||
286 | if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) | |
287 | return 1; | |
288 | ||
289 | if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { | |
290 | nl_pid_hash_rehash(hash, 0); | |
291 | return 1; | |
292 | } | |
293 | ||
294 | return 0; | |
295 | } | |
296 | ||
90ddc4f0 | 297 | static const struct proto_ops netlink_ops; |
1da177e4 | 298 | |
4277a083 PM |
299 | static void |
300 | netlink_update_listeners(struct sock *sk) | |
301 | { | |
302 | struct netlink_table *tbl = &nl_table[sk->sk_protocol]; | |
303 | struct hlist_node *node; | |
304 | unsigned long mask; | |
305 | unsigned int i; | |
306 | ||
307 | for (i = 0; i < NLGRPSZ(tbl->groups)/sizeof(unsigned long); i++) { | |
308 | mask = 0; | |
309 | sk_for_each_bound(sk, node, &tbl->mc_list) | |
310 | mask |= nlk_sk(sk)->groups[i]; | |
311 | tbl->listeners[i] = mask; | |
312 | } | |
313 | /* this function is only called with the netlink table "grabbed", which | |
314 | * makes sure updates are visible before bind or setsockopt return. */ | |
315 | } | |
316 | ||
1da177e4 LT |
317 | static int netlink_insert(struct sock *sk, u32 pid) |
318 | { | |
319 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
320 | struct hlist_head *head; | |
321 | int err = -EADDRINUSE; | |
322 | struct sock *osk; | |
323 | struct hlist_node *node; | |
324 | int len; | |
325 | ||
326 | netlink_table_grab(); | |
327 | head = nl_pid_hashfn(hash, pid); | |
328 | len = 0; | |
329 | sk_for_each(osk, node, head) { | |
330 | if (nlk_sk(osk)->pid == pid) | |
331 | break; | |
332 | len++; | |
333 | } | |
334 | if (node) | |
335 | goto err; | |
336 | ||
337 | err = -EBUSY; | |
338 | if (nlk_sk(sk)->pid) | |
339 | goto err; | |
340 | ||
341 | err = -ENOMEM; | |
342 | if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) | |
343 | goto err; | |
344 | ||
345 | if (len && nl_pid_hash_dilute(hash, len)) | |
346 | head = nl_pid_hashfn(hash, pid); | |
347 | hash->entries++; | |
348 | nlk_sk(sk)->pid = pid; | |
349 | sk_add_node(sk, head); | |
350 | err = 0; | |
351 | ||
352 | err: | |
353 | netlink_table_ungrab(); | |
354 | return err; | |
355 | } | |
356 | ||
357 | static void netlink_remove(struct sock *sk) | |
358 | { | |
359 | netlink_table_grab(); | |
d470e3b4 DM |
360 | if (sk_del_node_init(sk)) |
361 | nl_table[sk->sk_protocol].hash.entries--; | |
f7fa9b10 | 362 | if (nlk_sk(sk)->subscriptions) |
1da177e4 LT |
363 | __sk_del_bind_node(sk); |
364 | netlink_table_ungrab(); | |
365 | } | |
366 | ||
367 | static struct proto netlink_proto = { | |
368 | .name = "NETLINK", | |
369 | .owner = THIS_MODULE, | |
370 | .obj_size = sizeof(struct netlink_sock), | |
371 | }; | |
372 | ||
ab33a171 | 373 | static int __netlink_create(struct socket *sock, int protocol) |
1da177e4 LT |
374 | { |
375 | struct sock *sk; | |
376 | struct netlink_sock *nlk; | |
ab33a171 PM |
377 | |
378 | sock->ops = &netlink_ops; | |
379 | ||
380 | sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1); | |
381 | if (!sk) | |
382 | return -ENOMEM; | |
383 | ||
384 | sock_init_data(sock, sk); | |
385 | ||
386 | nlk = nlk_sk(sk); | |
387 | spin_lock_init(&nlk->cb_lock); | |
388 | init_waitqueue_head(&nlk->wait); | |
389 | ||
390 | sk->sk_destruct = netlink_sock_destruct; | |
391 | sk->sk_protocol = protocol; | |
392 | return 0; | |
393 | } | |
394 | ||
395 | static int netlink_create(struct socket *sock, int protocol) | |
396 | { | |
397 | struct module *module = NULL; | |
f7fa9b10 PM |
398 | struct netlink_sock *nlk; |
399 | unsigned int groups; | |
ab33a171 | 400 | int err = 0; |
1da177e4 LT |
401 | |
402 | sock->state = SS_UNCONNECTED; | |
403 | ||
404 | if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) | |
405 | return -ESOCKTNOSUPPORT; | |
406 | ||
407 | if (protocol<0 || protocol >= MAX_LINKS) | |
408 | return -EPROTONOSUPPORT; | |
409 | ||
77247bbb | 410 | netlink_lock_table(); |
4fdb3bb7 | 411 | #ifdef CONFIG_KMOD |
ab33a171 | 412 | if (!nl_table[protocol].registered) { |
77247bbb | 413 | netlink_unlock_table(); |
4fdb3bb7 | 414 | request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); |
77247bbb | 415 | netlink_lock_table(); |
4fdb3bb7 | 416 | } |
ab33a171 PM |
417 | #endif |
418 | if (nl_table[protocol].registered && | |
419 | try_module_get(nl_table[protocol].module)) | |
420 | module = nl_table[protocol].module; | |
f7fa9b10 | 421 | groups = nl_table[protocol].groups; |
77247bbb | 422 | netlink_unlock_table(); |
4fdb3bb7 | 423 | |
14591de1 | 424 | if ((err = __netlink_create(sock, protocol)) < 0) |
f7fa9b10 PM |
425 | goto out_module; |
426 | ||
427 | nlk = nlk_sk(sock->sk); | |
f7fa9b10 | 428 | nlk->module = module; |
ab33a171 PM |
429 | out: |
430 | return err; | |
1da177e4 | 431 | |
ab33a171 PM |
432 | out_module: |
433 | module_put(module); | |
434 | goto out; | |
1da177e4 LT |
435 | } |
436 | ||
437 | static int netlink_release(struct socket *sock) | |
438 | { | |
439 | struct sock *sk = sock->sk; | |
440 | struct netlink_sock *nlk; | |
441 | ||
442 | if (!sk) | |
443 | return 0; | |
444 | ||
445 | netlink_remove(sk); | |
446 | nlk = nlk_sk(sk); | |
447 | ||
448 | spin_lock(&nlk->cb_lock); | |
449 | if (nlk->cb) { | |
a8f74b22 TG |
450 | if (nlk->cb->done) |
451 | nlk->cb->done(nlk->cb); | |
1da177e4 LT |
452 | netlink_destroy_callback(nlk->cb); |
453 | nlk->cb = NULL; | |
1da177e4 LT |
454 | } |
455 | spin_unlock(&nlk->cb_lock); | |
456 | ||
457 | /* OK. Socket is unlinked, and, therefore, | |
458 | no new packets will arrive */ | |
459 | ||
460 | sock_orphan(sk); | |
461 | sock->sk = NULL; | |
462 | wake_up_interruptible_all(&nlk->wait); | |
463 | ||
464 | skb_queue_purge(&sk->sk_write_queue); | |
465 | ||
f7fa9b10 | 466 | if (nlk->pid && !nlk->subscriptions) { |
1da177e4 LT |
467 | struct netlink_notify n = { |
468 | .protocol = sk->sk_protocol, | |
469 | .pid = nlk->pid, | |
470 | }; | |
e041c683 AS |
471 | atomic_notifier_call_chain(&netlink_chain, |
472 | NETLINK_URELEASE, &n); | |
1da177e4 | 473 | } |
4fdb3bb7 | 474 | |
77247bbb PM |
475 | if (nlk->module) |
476 | module_put(nlk->module); | |
4fdb3bb7 | 477 | |
4277a083 | 478 | netlink_table_grab(); |
77247bbb | 479 | if (nlk->flags & NETLINK_KERNEL_SOCKET) { |
4277a083 | 480 | kfree(nl_table[sk->sk_protocol].listeners); |
77247bbb | 481 | nl_table[sk->sk_protocol].module = NULL; |
ab33a171 | 482 | nl_table[sk->sk_protocol].registered = 0; |
4277a083 PM |
483 | } else if (nlk->subscriptions) |
484 | netlink_update_listeners(sk); | |
485 | netlink_table_ungrab(); | |
77247bbb | 486 | |
f7fa9b10 PM |
487 | kfree(nlk->groups); |
488 | nlk->groups = NULL; | |
489 | ||
1da177e4 LT |
490 | sock_put(sk); |
491 | return 0; | |
492 | } | |
493 | ||
494 | static int netlink_autobind(struct socket *sock) | |
495 | { | |
496 | struct sock *sk = sock->sk; | |
497 | struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; | |
498 | struct hlist_head *head; | |
499 | struct sock *osk; | |
500 | struct hlist_node *node; | |
c27bd492 | 501 | s32 pid = current->tgid; |
1da177e4 LT |
502 | int err; |
503 | static s32 rover = -4097; | |
504 | ||
505 | retry: | |
506 | cond_resched(); | |
507 | netlink_table_grab(); | |
508 | head = nl_pid_hashfn(hash, pid); | |
509 | sk_for_each(osk, node, head) { | |
510 | if (nlk_sk(osk)->pid == pid) { | |
511 | /* Bind collision, search negative pid values. */ | |
512 | pid = rover--; | |
513 | if (rover > -4097) | |
514 | rover = -4097; | |
515 | netlink_table_ungrab(); | |
516 | goto retry; | |
517 | } | |
518 | } | |
519 | netlink_table_ungrab(); | |
520 | ||
521 | err = netlink_insert(sk, pid); | |
522 | if (err == -EADDRINUSE) | |
523 | goto retry; | |
d470e3b4 DM |
524 | |
525 | /* If 2 threads race to autobind, that is fine. */ | |
526 | if (err == -EBUSY) | |
527 | err = 0; | |
528 | ||
529 | return err; | |
1da177e4 LT |
530 | } |
531 | ||
532 | static inline int netlink_capable(struct socket *sock, unsigned int flag) | |
533 | { | |
534 | return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || | |
535 | capable(CAP_NET_ADMIN); | |
536 | } | |
537 | ||
f7fa9b10 PM |
538 | static void |
539 | netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) | |
540 | { | |
541 | struct netlink_sock *nlk = nlk_sk(sk); | |
542 | ||
543 | if (nlk->subscriptions && !subscriptions) | |
544 | __sk_del_bind_node(sk); | |
545 | else if (!nlk->subscriptions && subscriptions) | |
546 | sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); | |
547 | nlk->subscriptions = subscriptions; | |
548 | } | |
549 | ||
513c2500 PM |
550 | static int netlink_alloc_groups(struct sock *sk) |
551 | { | |
552 | struct netlink_sock *nlk = nlk_sk(sk); | |
553 | unsigned int groups; | |
554 | int err = 0; | |
555 | ||
556 | netlink_lock_table(); | |
557 | groups = nl_table[sk->sk_protocol].groups; | |
558 | if (!nl_table[sk->sk_protocol].registered) | |
559 | err = -ENOENT; | |
560 | netlink_unlock_table(); | |
561 | ||
562 | if (err) | |
563 | return err; | |
564 | ||
0da974f4 | 565 | nlk->groups = kzalloc(NLGRPSZ(groups), GFP_KERNEL); |
513c2500 PM |
566 | if (nlk->groups == NULL) |
567 | return -ENOMEM; | |
513c2500 PM |
568 | nlk->ngroups = groups; |
569 | return 0; | |
570 | } | |
571 | ||
1da177e4 LT |
572 | static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) |
573 | { | |
574 | struct sock *sk = sock->sk; | |
575 | struct netlink_sock *nlk = nlk_sk(sk); | |
576 | struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; | |
577 | int err; | |
578 | ||
579 | if (nladdr->nl_family != AF_NETLINK) | |
580 | return -EINVAL; | |
581 | ||
582 | /* Only superuser is allowed to listen multicasts */ | |
513c2500 PM |
583 | if (nladdr->nl_groups) { |
584 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
585 | return -EPERM; | |
586 | if (nlk->groups == NULL) { | |
587 | err = netlink_alloc_groups(sk); | |
588 | if (err) | |
589 | return err; | |
590 | } | |
591 | } | |
1da177e4 LT |
592 | |
593 | if (nlk->pid) { | |
594 | if (nladdr->nl_pid != nlk->pid) | |
595 | return -EINVAL; | |
596 | } else { | |
597 | err = nladdr->nl_pid ? | |
598 | netlink_insert(sk, nladdr->nl_pid) : | |
599 | netlink_autobind(sock); | |
600 | if (err) | |
601 | return err; | |
602 | } | |
603 | ||
513c2500 | 604 | if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) |
1da177e4 LT |
605 | return 0; |
606 | ||
607 | netlink_table_grab(); | |
f7fa9b10 PM |
608 | netlink_update_subscriptions(sk, nlk->subscriptions + |
609 | hweight32(nladdr->nl_groups) - | |
610 | hweight32(nlk->groups[0])); | |
611 | nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; | |
4277a083 | 612 | netlink_update_listeners(sk); |
1da177e4 LT |
613 | netlink_table_ungrab(); |
614 | ||
615 | return 0; | |
616 | } | |
617 | ||
618 | static int netlink_connect(struct socket *sock, struct sockaddr *addr, | |
619 | int alen, int flags) | |
620 | { | |
621 | int err = 0; | |
622 | struct sock *sk = sock->sk; | |
623 | struct netlink_sock *nlk = nlk_sk(sk); | |
624 | struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr; | |
625 | ||
626 | if (addr->sa_family == AF_UNSPEC) { | |
627 | sk->sk_state = NETLINK_UNCONNECTED; | |
628 | nlk->dst_pid = 0; | |
d629b836 | 629 | nlk->dst_group = 0; |
1da177e4 LT |
630 | return 0; |
631 | } | |
632 | if (addr->sa_family != AF_NETLINK) | |
633 | return -EINVAL; | |
634 | ||
635 | /* Only superuser is allowed to send multicasts */ | |
636 | if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) | |
637 | return -EPERM; | |
638 | ||
639 | if (!nlk->pid) | |
640 | err = netlink_autobind(sock); | |
641 | ||
642 | if (err == 0) { | |
643 | sk->sk_state = NETLINK_CONNECTED; | |
644 | nlk->dst_pid = nladdr->nl_pid; | |
d629b836 | 645 | nlk->dst_group = ffs(nladdr->nl_groups); |
1da177e4 LT |
646 | } |
647 | ||
648 | return err; | |
649 | } | |
650 | ||
651 | static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) | |
652 | { | |
653 | struct sock *sk = sock->sk; | |
654 | struct netlink_sock *nlk = nlk_sk(sk); | |
655 | struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr; | |
656 | ||
657 | nladdr->nl_family = AF_NETLINK; | |
658 | nladdr->nl_pad = 0; | |
659 | *addr_len = sizeof(*nladdr); | |
660 | ||
661 | if (peer) { | |
662 | nladdr->nl_pid = nlk->dst_pid; | |
d629b836 | 663 | nladdr->nl_groups = netlink_group_mask(nlk->dst_group); |
1da177e4 LT |
664 | } else { |
665 | nladdr->nl_pid = nlk->pid; | |
513c2500 | 666 | nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; |
1da177e4 LT |
667 | } |
668 | return 0; | |
669 | } | |
670 | ||
671 | static void netlink_overrun(struct sock *sk) | |
672 | { | |
673 | if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { | |
674 | sk->sk_err = ENOBUFS; | |
675 | sk->sk_error_report(sk); | |
676 | } | |
677 | } | |
678 | ||
679 | static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) | |
680 | { | |
681 | int protocol = ssk->sk_protocol; | |
682 | struct sock *sock; | |
683 | struct netlink_sock *nlk; | |
684 | ||
685 | sock = netlink_lookup(protocol, pid); | |
686 | if (!sock) | |
687 | return ERR_PTR(-ECONNREFUSED); | |
688 | ||
689 | /* Don't bother queuing skb if kernel socket has no input function */ | |
690 | nlk = nlk_sk(sock); | |
691 | if ((nlk->pid == 0 && !nlk->data_ready) || | |
692 | (sock->sk_state == NETLINK_CONNECTED && | |
693 | nlk->dst_pid != nlk_sk(ssk)->pid)) { | |
694 | sock_put(sock); | |
695 | return ERR_PTR(-ECONNREFUSED); | |
696 | } | |
697 | return sock; | |
698 | } | |
699 | ||
700 | struct sock *netlink_getsockbyfilp(struct file *filp) | |
701 | { | |
702 | struct inode *inode = filp->f_dentry->d_inode; | |
703 | struct sock *sock; | |
704 | ||
705 | if (!S_ISSOCK(inode->i_mode)) | |
706 | return ERR_PTR(-ENOTSOCK); | |
707 | ||
708 | sock = SOCKET_I(inode)->sk; | |
709 | if (sock->sk_family != AF_NETLINK) | |
710 | return ERR_PTR(-EINVAL); | |
711 | ||
712 | sock_hold(sock); | |
713 | return sock; | |
714 | } | |
715 | ||
716 | /* | |
717 | * Attach a skb to a netlink socket. | |
718 | * The caller must hold a reference to the destination socket. On error, the | |
719 | * reference is dropped. The skb is not send to the destination, just all | |
720 | * all error checks are performed and memory in the queue is reserved. | |
721 | * Return values: | |
722 | * < 0: error. skb freed, reference to sock dropped. | |
723 | * 0: continue | |
724 | * 1: repeat lookup - reference dropped while waiting for socket memory. | |
725 | */ | |
a70ea994 AK |
726 | int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, |
727 | long timeo, struct sock *ssk) | |
1da177e4 LT |
728 | { |
729 | struct netlink_sock *nlk; | |
730 | ||
731 | nlk = nlk_sk(sk); | |
732 | ||
733 | if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
734 | test_bit(0, &nlk->state)) { | |
735 | DECLARE_WAITQUEUE(wait, current); | |
736 | if (!timeo) { | |
a70ea994 | 737 | if (!ssk || nlk_sk(ssk)->pid == 0) |
1da177e4 LT |
738 | netlink_overrun(sk); |
739 | sock_put(sk); | |
740 | kfree_skb(skb); | |
741 | return -EAGAIN; | |
742 | } | |
743 | ||
744 | __set_current_state(TASK_INTERRUPTIBLE); | |
745 | add_wait_queue(&nlk->wait, &wait); | |
746 | ||
747 | if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || | |
748 | test_bit(0, &nlk->state)) && | |
749 | !sock_flag(sk, SOCK_DEAD)) | |
750 | timeo = schedule_timeout(timeo); | |
751 | ||
752 | __set_current_state(TASK_RUNNING); | |
753 | remove_wait_queue(&nlk->wait, &wait); | |
754 | sock_put(sk); | |
755 | ||
756 | if (signal_pending(current)) { | |
757 | kfree_skb(skb); | |
758 | return sock_intr_errno(timeo); | |
759 | } | |
760 | return 1; | |
761 | } | |
762 | skb_set_owner_r(skb, sk); | |
763 | return 0; | |
764 | } | |
765 | ||
766 | int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol) | |
767 | { | |
1da177e4 LT |
768 | int len = skb->len; |
769 | ||
1da177e4 LT |
770 | skb_queue_tail(&sk->sk_receive_queue, skb); |
771 | sk->sk_data_ready(sk, len); | |
772 | sock_put(sk); | |
773 | return len; | |
774 | } | |
775 | ||
776 | void netlink_detachskb(struct sock *sk, struct sk_buff *skb) | |
777 | { | |
778 | kfree_skb(skb); | |
779 | sock_put(sk); | |
780 | } | |
781 | ||
37da647d | 782 | static inline struct sk_buff *netlink_trim(struct sk_buff *skb, |
dd0fc66f | 783 | gfp_t allocation) |
1da177e4 LT |
784 | { |
785 | int delta; | |
786 | ||
787 | skb_orphan(skb); | |
788 | ||
789 | delta = skb->end - skb->tail; | |
790 | if (delta * 2 < skb->truesize) | |
791 | return skb; | |
792 | ||
793 | if (skb_shared(skb)) { | |
794 | struct sk_buff *nskb = skb_clone(skb, allocation); | |
795 | if (!nskb) | |
796 | return skb; | |
797 | kfree_skb(skb); | |
798 | skb = nskb; | |
799 | } | |
800 | ||
801 | if (!pskb_expand_head(skb, 0, -delta, allocation)) | |
802 | skb->truesize -= delta; | |
803 | ||
804 | return skb; | |
805 | } | |
806 | ||
807 | int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock) | |
808 | { | |
809 | struct sock *sk; | |
810 | int err; | |
811 | long timeo; | |
812 | ||
813 | skb = netlink_trim(skb, gfp_any()); | |
814 | ||
815 | timeo = sock_sndtimeo(ssk, nonblock); | |
816 | retry: | |
817 | sk = netlink_getsockbypid(ssk, pid); | |
818 | if (IS_ERR(sk)) { | |
819 | kfree_skb(skb); | |
820 | return PTR_ERR(sk); | |
821 | } | |
a70ea994 | 822 | err = netlink_attachskb(sk, skb, nonblock, timeo, ssk); |
1da177e4 LT |
823 | if (err == 1) |
824 | goto retry; | |
825 | if (err) | |
826 | return err; | |
827 | ||
828 | return netlink_sendskb(sk, skb, ssk->sk_protocol); | |
829 | } | |
830 | ||
4277a083 PM |
831 | int netlink_has_listeners(struct sock *sk, unsigned int group) |
832 | { | |
833 | int res = 0; | |
834 | ||
835 | BUG_ON(!(nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET)); | |
836 | if (group - 1 < nl_table[sk->sk_protocol].groups) | |
837 | res = test_bit(group - 1, nl_table[sk->sk_protocol].listeners); | |
838 | return res; | |
839 | } | |
840 | EXPORT_SYMBOL_GPL(netlink_has_listeners); | |
841 | ||
1da177e4 LT |
842 | static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) |
843 | { | |
844 | struct netlink_sock *nlk = nlk_sk(sk); | |
845 | ||
846 | if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && | |
847 | !test_bit(0, &nlk->state)) { | |
848 | skb_set_owner_r(skb, sk); | |
849 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
850 | sk->sk_data_ready(sk, skb->len); | |
851 | return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; | |
852 | } | |
853 | return -1; | |
854 | } | |
855 | ||
856 | struct netlink_broadcast_data { | |
857 | struct sock *exclude_sk; | |
858 | u32 pid; | |
859 | u32 group; | |
860 | int failure; | |
861 | int congested; | |
862 | int delivered; | |
7d877f3b | 863 | gfp_t allocation; |
1da177e4 LT |
864 | struct sk_buff *skb, *skb2; |
865 | }; | |
866 | ||
867 | static inline int do_one_broadcast(struct sock *sk, | |
868 | struct netlink_broadcast_data *p) | |
869 | { | |
870 | struct netlink_sock *nlk = nlk_sk(sk); | |
871 | int val; | |
872 | ||
873 | if (p->exclude_sk == sk) | |
874 | goto out; | |
875 | ||
f7fa9b10 PM |
876 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
877 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
878 | goto out; |
879 | ||
880 | if (p->failure) { | |
881 | netlink_overrun(sk); | |
882 | goto out; | |
883 | } | |
884 | ||
885 | sock_hold(sk); | |
886 | if (p->skb2 == NULL) { | |
68acc024 | 887 | if (skb_shared(p->skb)) { |
1da177e4 LT |
888 | p->skb2 = skb_clone(p->skb, p->allocation); |
889 | } else { | |
68acc024 TC |
890 | p->skb2 = skb_get(p->skb); |
891 | /* | |
892 | * skb ownership may have been set when | |
893 | * delivered to a previous socket. | |
894 | */ | |
895 | skb_orphan(p->skb2); | |
1da177e4 LT |
896 | } |
897 | } | |
898 | if (p->skb2 == NULL) { | |
899 | netlink_overrun(sk); | |
900 | /* Clone failed. Notify ALL listeners. */ | |
901 | p->failure = 1; | |
902 | } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { | |
903 | netlink_overrun(sk); | |
904 | } else { | |
905 | p->congested |= val; | |
906 | p->delivered = 1; | |
907 | p->skb2 = NULL; | |
908 | } | |
909 | sock_put(sk); | |
910 | ||
911 | out: | |
912 | return 0; | |
913 | } | |
914 | ||
915 | int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, | |
dd0fc66f | 916 | u32 group, gfp_t allocation) |
1da177e4 LT |
917 | { |
918 | struct netlink_broadcast_data info; | |
919 | struct hlist_node *node; | |
920 | struct sock *sk; | |
921 | ||
922 | skb = netlink_trim(skb, allocation); | |
923 | ||
924 | info.exclude_sk = ssk; | |
925 | info.pid = pid; | |
926 | info.group = group; | |
927 | info.failure = 0; | |
928 | info.congested = 0; | |
929 | info.delivered = 0; | |
930 | info.allocation = allocation; | |
931 | info.skb = skb; | |
932 | info.skb2 = NULL; | |
933 | ||
934 | /* While we sleep in clone, do not allow to change socket list */ | |
935 | ||
936 | netlink_lock_table(); | |
937 | ||
938 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
939 | do_one_broadcast(sk, &info); | |
940 | ||
aa1c6a6f TC |
941 | kfree_skb(skb); |
942 | ||
1da177e4 LT |
943 | netlink_unlock_table(); |
944 | ||
945 | if (info.skb2) | |
946 | kfree_skb(info.skb2); | |
1da177e4 LT |
947 | |
948 | if (info.delivered) { | |
949 | if (info.congested && (allocation & __GFP_WAIT)) | |
950 | yield(); | |
951 | return 0; | |
952 | } | |
953 | if (info.failure) | |
954 | return -ENOBUFS; | |
955 | return -ESRCH; | |
956 | } | |
957 | ||
958 | struct netlink_set_err_data { | |
959 | struct sock *exclude_sk; | |
960 | u32 pid; | |
961 | u32 group; | |
962 | int code; | |
963 | }; | |
964 | ||
965 | static inline int do_one_set_err(struct sock *sk, | |
966 | struct netlink_set_err_data *p) | |
967 | { | |
968 | struct netlink_sock *nlk = nlk_sk(sk); | |
969 | ||
970 | if (sk == p->exclude_sk) | |
971 | goto out; | |
972 | ||
f7fa9b10 PM |
973 | if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || |
974 | !test_bit(p->group - 1, nlk->groups)) | |
1da177e4 LT |
975 | goto out; |
976 | ||
977 | sk->sk_err = p->code; | |
978 | sk->sk_error_report(sk); | |
979 | out: | |
980 | return 0; | |
981 | } | |
982 | ||
983 | void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) | |
984 | { | |
985 | struct netlink_set_err_data info; | |
986 | struct hlist_node *node; | |
987 | struct sock *sk; | |
988 | ||
989 | info.exclude_sk = ssk; | |
990 | info.pid = pid; | |
991 | info.group = group; | |
992 | info.code = code; | |
993 | ||
994 | read_lock(&nl_table_lock); | |
995 | ||
996 | sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) | |
997 | do_one_set_err(sk, &info); | |
998 | ||
999 | read_unlock(&nl_table_lock); | |
1000 | } | |
1001 | ||
9a4595bc PM |
1002 | static int netlink_setsockopt(struct socket *sock, int level, int optname, |
1003 | char __user *optval, int optlen) | |
1004 | { | |
1005 | struct sock *sk = sock->sk; | |
1006 | struct netlink_sock *nlk = nlk_sk(sk); | |
1007 | int val = 0, err; | |
1008 | ||
1009 | if (level != SOL_NETLINK) | |
1010 | return -ENOPROTOOPT; | |
1011 | ||
1012 | if (optlen >= sizeof(int) && | |
1013 | get_user(val, (int __user *)optval)) | |
1014 | return -EFAULT; | |
1015 | ||
1016 | switch (optname) { | |
1017 | case NETLINK_PKTINFO: | |
1018 | if (val) | |
1019 | nlk->flags |= NETLINK_RECV_PKTINFO; | |
1020 | else | |
1021 | nlk->flags &= ~NETLINK_RECV_PKTINFO; | |
1022 | err = 0; | |
1023 | break; | |
1024 | case NETLINK_ADD_MEMBERSHIP: | |
1025 | case NETLINK_DROP_MEMBERSHIP: { | |
1026 | unsigned int subscriptions; | |
1027 | int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0; | |
1028 | ||
1029 | if (!netlink_capable(sock, NL_NONROOT_RECV)) | |
1030 | return -EPERM; | |
513c2500 PM |
1031 | if (nlk->groups == NULL) { |
1032 | err = netlink_alloc_groups(sk); | |
1033 | if (err) | |
1034 | return err; | |
1035 | } | |
9a4595bc PM |
1036 | if (!val || val - 1 >= nlk->ngroups) |
1037 | return -EINVAL; | |
1038 | netlink_table_grab(); | |
1039 | old = test_bit(val - 1, nlk->groups); | |
1040 | subscriptions = nlk->subscriptions - old + new; | |
1041 | if (new) | |
1042 | __set_bit(val - 1, nlk->groups); | |
1043 | else | |
1044 | __clear_bit(val - 1, nlk->groups); | |
1045 | netlink_update_subscriptions(sk, subscriptions); | |
4277a083 | 1046 | netlink_update_listeners(sk); |
9a4595bc PM |
1047 | netlink_table_ungrab(); |
1048 | err = 0; | |
1049 | break; | |
1050 | } | |
1051 | default: | |
1052 | err = -ENOPROTOOPT; | |
1053 | } | |
1054 | return err; | |
1055 | } | |
1056 | ||
1057 | static int netlink_getsockopt(struct socket *sock, int level, int optname, | |
1058 | char __user *optval, int __user *optlen) | |
1059 | { | |
1060 | struct sock *sk = sock->sk; | |
1061 | struct netlink_sock *nlk = nlk_sk(sk); | |
1062 | int len, val, err; | |
1063 | ||
1064 | if (level != SOL_NETLINK) | |
1065 | return -ENOPROTOOPT; | |
1066 | ||
1067 | if (get_user(len, optlen)) | |
1068 | return -EFAULT; | |
1069 | if (len < 0) | |
1070 | return -EINVAL; | |
1071 | ||
1072 | switch (optname) { | |
1073 | case NETLINK_PKTINFO: | |
1074 | if (len < sizeof(int)) | |
1075 | return -EINVAL; | |
1076 | len = sizeof(int); | |
1077 | val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; | |
1078 | put_user(len, optlen); | |
1079 | put_user(val, optval); | |
1080 | err = 0; | |
1081 | break; | |
1082 | default: | |
1083 | err = -ENOPROTOOPT; | |
1084 | } | |
1085 | return err; | |
1086 | } | |
1087 | ||
1088 | static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) | |
1089 | { | |
1090 | struct nl_pktinfo info; | |
1091 | ||
1092 | info.group = NETLINK_CB(skb).dst_group; | |
1093 | put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); | |
1094 | } | |
1095 | ||
1da177e4 LT |
1096 | static inline void netlink_rcv_wake(struct sock *sk) |
1097 | { | |
1098 | struct netlink_sock *nlk = nlk_sk(sk); | |
1099 | ||
b03efcfb | 1100 | if (skb_queue_empty(&sk->sk_receive_queue)) |
1da177e4 LT |
1101 | clear_bit(0, &nlk->state); |
1102 | if (!test_bit(0, &nlk->state)) | |
1103 | wake_up_interruptible(&nlk->wait); | |
1104 | } | |
1105 | ||
1106 | static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, | |
1107 | struct msghdr *msg, size_t len) | |
1108 | { | |
1109 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1110 | struct sock *sk = sock->sk; | |
1111 | struct netlink_sock *nlk = nlk_sk(sk); | |
1112 | struct sockaddr_nl *addr=msg->msg_name; | |
1113 | u32 dst_pid; | |
d629b836 | 1114 | u32 dst_group; |
1da177e4 LT |
1115 | struct sk_buff *skb; |
1116 | int err; | |
1117 | struct scm_cookie scm; | |
1118 | ||
1119 | if (msg->msg_flags&MSG_OOB) | |
1120 | return -EOPNOTSUPP; | |
1121 | ||
1122 | if (NULL == siocb->scm) | |
1123 | siocb->scm = &scm; | |
1124 | err = scm_send(sock, msg, siocb->scm); | |
1125 | if (err < 0) | |
1126 | return err; | |
1127 | ||
1128 | if (msg->msg_namelen) { | |
1129 | if (addr->nl_family != AF_NETLINK) | |
1130 | return -EINVAL; | |
1131 | dst_pid = addr->nl_pid; | |
d629b836 PM |
1132 | dst_group = ffs(addr->nl_groups); |
1133 | if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) | |
1da177e4 LT |
1134 | return -EPERM; |
1135 | } else { | |
1136 | dst_pid = nlk->dst_pid; | |
d629b836 | 1137 | dst_group = nlk->dst_group; |
1da177e4 LT |
1138 | } |
1139 | ||
1140 | if (!nlk->pid) { | |
1141 | err = netlink_autobind(sock); | |
1142 | if (err) | |
1143 | goto out; | |
1144 | } | |
1145 | ||
1146 | err = -EMSGSIZE; | |
1147 | if (len > sk->sk_sndbuf - 32) | |
1148 | goto out; | |
1149 | err = -ENOBUFS; | |
bf8b79e4 | 1150 | skb = nlmsg_new(len, GFP_KERNEL); |
1da177e4 LT |
1151 | if (skb==NULL) |
1152 | goto out; | |
1153 | ||
1154 | NETLINK_CB(skb).pid = nlk->pid; | |
1da177e4 | 1155 | NETLINK_CB(skb).dst_pid = dst_pid; |
d629b836 | 1156 | NETLINK_CB(skb).dst_group = dst_group; |
c94c257c | 1157 | NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); |
e7c34970 | 1158 | selinux_get_task_sid(current, &(NETLINK_CB(skb).sid)); |
1da177e4 LT |
1159 | memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); |
1160 | ||
1161 | /* What can I do? Netlink is asynchronous, so that | |
1162 | we will have to save current capabilities to | |
1163 | check them, when this message will be delivered | |
1164 | to corresponding kernel module. --ANK (980802) | |
1165 | */ | |
1166 | ||
1167 | err = -EFAULT; | |
1168 | if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) { | |
1169 | kfree_skb(skb); | |
1170 | goto out; | |
1171 | } | |
1172 | ||
1173 | err = security_netlink_send(sk, skb); | |
1174 | if (err) { | |
1175 | kfree_skb(skb); | |
1176 | goto out; | |
1177 | } | |
1178 | ||
d629b836 | 1179 | if (dst_group) { |
1da177e4 | 1180 | atomic_inc(&skb->users); |
d629b836 | 1181 | netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); |
1da177e4 LT |
1182 | } |
1183 | err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); | |
1184 | ||
1185 | out: | |
1186 | return err; | |
1187 | } | |
1188 | ||
1189 | static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, | |
1190 | struct msghdr *msg, size_t len, | |
1191 | int flags) | |
1192 | { | |
1193 | struct sock_iocb *siocb = kiocb_to_siocb(kiocb); | |
1194 | struct scm_cookie scm; | |
1195 | struct sock *sk = sock->sk; | |
1196 | struct netlink_sock *nlk = nlk_sk(sk); | |
1197 | int noblock = flags&MSG_DONTWAIT; | |
1198 | size_t copied; | |
1199 | struct sk_buff *skb; | |
1200 | int err; | |
1201 | ||
1202 | if (flags&MSG_OOB) | |
1203 | return -EOPNOTSUPP; | |
1204 | ||
1205 | copied = 0; | |
1206 | ||
1207 | skb = skb_recv_datagram(sk,flags,noblock,&err); | |
1208 | if (skb==NULL) | |
1209 | goto out; | |
1210 | ||
1211 | msg->msg_namelen = 0; | |
1212 | ||
1213 | copied = skb->len; | |
1214 | if (len < copied) { | |
1215 | msg->msg_flags |= MSG_TRUNC; | |
1216 | copied = len; | |
1217 | } | |
1218 | ||
1219 | skb->h.raw = skb->data; | |
1220 | err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); | |
1221 | ||
1222 | if (msg->msg_name) { | |
1223 | struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name; | |
1224 | addr->nl_family = AF_NETLINK; | |
1225 | addr->nl_pad = 0; | |
1226 | addr->nl_pid = NETLINK_CB(skb).pid; | |
d629b836 | 1227 | addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); |
1da177e4 LT |
1228 | msg->msg_namelen = sizeof(*addr); |
1229 | } | |
1230 | ||
cc9a06cd PM |
1231 | if (nlk->flags & NETLINK_RECV_PKTINFO) |
1232 | netlink_cmsg_recv_pktinfo(msg, skb); | |
1233 | ||
1da177e4 LT |
1234 | if (NULL == siocb->scm) { |
1235 | memset(&scm, 0, sizeof(scm)); | |
1236 | siocb->scm = &scm; | |
1237 | } | |
1238 | siocb->scm->creds = *NETLINK_CREDS(skb); | |
1239 | skb_free_datagram(sk, skb); | |
1240 | ||
1241 | if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) | |
1242 | netlink_dump(sk); | |
1243 | ||
1244 | scm_recv(sock, msg, siocb->scm, flags); | |
1245 | ||
1246 | out: | |
1247 | netlink_rcv_wake(sk); | |
1248 | return err ? : copied; | |
1249 | } | |
1250 | ||
1251 | static void netlink_data_ready(struct sock *sk, int len) | |
1252 | { | |
1253 | struct netlink_sock *nlk = nlk_sk(sk); | |
1254 | ||
1255 | if (nlk->data_ready) | |
1256 | nlk->data_ready(sk, len); | |
1257 | netlink_rcv_wake(sk); | |
1258 | } | |
1259 | ||
1260 | /* | |
1261 | * We export these functions to other modules. They provide a | |
1262 | * complete set of kernel non-blocking support for message | |
1263 | * queueing. | |
1264 | */ | |
1265 | ||
1266 | struct sock * | |
06628607 PM |
1267 | netlink_kernel_create(int unit, unsigned int groups, |
1268 | void (*input)(struct sock *sk, int len), | |
1269 | struct module *module) | |
1da177e4 LT |
1270 | { |
1271 | struct socket *sock; | |
1272 | struct sock *sk; | |
77247bbb | 1273 | struct netlink_sock *nlk; |
4277a083 | 1274 | unsigned long *listeners = NULL; |
1da177e4 | 1275 | |
fab2caf6 | 1276 | BUG_ON(!nl_table); |
1da177e4 LT |
1277 | |
1278 | if (unit<0 || unit>=MAX_LINKS) | |
1279 | return NULL; | |
1280 | ||
1281 | if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) | |
1282 | return NULL; | |
1283 | ||
ab33a171 | 1284 | if (__netlink_create(sock, unit) < 0) |
77247bbb | 1285 | goto out_sock_release; |
4fdb3bb7 | 1286 | |
4277a083 PM |
1287 | if (groups < 32) |
1288 | groups = 32; | |
1289 | ||
1290 | listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL); | |
1291 | if (!listeners) | |
1292 | goto out_sock_release; | |
1293 | ||
1da177e4 LT |
1294 | sk = sock->sk; |
1295 | sk->sk_data_ready = netlink_data_ready; | |
1296 | if (input) | |
1297 | nlk_sk(sk)->data_ready = input; | |
1298 | ||
77247bbb PM |
1299 | if (netlink_insert(sk, 0)) |
1300 | goto out_sock_release; | |
4fdb3bb7 | 1301 | |
77247bbb PM |
1302 | nlk = nlk_sk(sk); |
1303 | nlk->flags |= NETLINK_KERNEL_SOCKET; | |
4fdb3bb7 | 1304 | |
4fdb3bb7 | 1305 | netlink_table_grab(); |
4277a083 PM |
1306 | nl_table[unit].groups = groups; |
1307 | nl_table[unit].listeners = listeners; | |
77247bbb | 1308 | nl_table[unit].module = module; |
ab33a171 | 1309 | nl_table[unit].registered = 1; |
4fdb3bb7 | 1310 | netlink_table_ungrab(); |
77247bbb PM |
1311 | |
1312 | return sk; | |
1313 | ||
4fdb3bb7 | 1314 | out_sock_release: |
4277a083 | 1315 | kfree(listeners); |
4fdb3bb7 | 1316 | sock_release(sock); |
77247bbb | 1317 | return NULL; |
1da177e4 LT |
1318 | } |
1319 | ||
1320 | void netlink_set_nonroot(int protocol, unsigned int flags) | |
1321 | { | |
1322 | if ((unsigned int)protocol < MAX_LINKS) | |
1323 | nl_table[protocol].nl_nonroot = flags; | |
1324 | } | |
1325 | ||
1326 | static void netlink_destroy_callback(struct netlink_callback *cb) | |
1327 | { | |
1328 | if (cb->skb) | |
1329 | kfree_skb(cb->skb); | |
1330 | kfree(cb); | |
1331 | } | |
1332 | ||
1333 | /* | |
1334 | * It looks a bit ugly. | |
1335 | * It would be better to create kernel thread. | |
1336 | */ | |
1337 | ||
1338 | static int netlink_dump(struct sock *sk) | |
1339 | { | |
1340 | struct netlink_sock *nlk = nlk_sk(sk); | |
1341 | struct netlink_callback *cb; | |
1342 | struct sk_buff *skb; | |
1343 | struct nlmsghdr *nlh; | |
bf8b79e4 | 1344 | int len, err = -ENOBUFS; |
1da177e4 LT |
1345 | |
1346 | skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); | |
1347 | if (!skb) | |
bf8b79e4 | 1348 | goto errout; |
1da177e4 LT |
1349 | |
1350 | spin_lock(&nlk->cb_lock); | |
1351 | ||
1352 | cb = nlk->cb; | |
1353 | if (cb == NULL) { | |
bf8b79e4 TG |
1354 | err = -EINVAL; |
1355 | goto errout_skb; | |
1da177e4 LT |
1356 | } |
1357 | ||
1358 | len = cb->dump(skb, cb); | |
1359 | ||
1360 | if (len > 0) { | |
1361 | spin_unlock(&nlk->cb_lock); | |
1362 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
1363 | sk->sk_data_ready(sk, len); | |
1364 | return 0; | |
1365 | } | |
1366 | ||
bf8b79e4 TG |
1367 | nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); |
1368 | if (!nlh) | |
1369 | goto errout_skb; | |
1370 | ||
1371 | memcpy(nlmsg_data(nlh), &len, sizeof(len)); | |
1372 | ||
1da177e4 LT |
1373 | skb_queue_tail(&sk->sk_receive_queue, skb); |
1374 | sk->sk_data_ready(sk, skb->len); | |
1375 | ||
a8f74b22 TG |
1376 | if (cb->done) |
1377 | cb->done(cb); | |
1da177e4 LT |
1378 | nlk->cb = NULL; |
1379 | spin_unlock(&nlk->cb_lock); | |
1380 | ||
1381 | netlink_destroy_callback(cb); | |
1da177e4 | 1382 | return 0; |
1797754e | 1383 | |
bf8b79e4 TG |
1384 | errout_skb: |
1385 | spin_unlock(&nlk->cb_lock); | |
1386 | kfree_skb(skb); | |
1387 | errout: | |
1388 | return err; | |
1da177e4 LT |
1389 | } |
1390 | ||
1391 | int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, | |
1392 | struct nlmsghdr *nlh, | |
1393 | int (*dump)(struct sk_buff *skb, struct netlink_callback*), | |
1394 | int (*done)(struct netlink_callback*)) | |
1395 | { | |
1396 | struct netlink_callback *cb; | |
1397 | struct sock *sk; | |
1398 | struct netlink_sock *nlk; | |
1399 | ||
0da974f4 | 1400 | cb = kzalloc(sizeof(*cb), GFP_KERNEL); |
1da177e4 LT |
1401 | if (cb == NULL) |
1402 | return -ENOBUFS; | |
1403 | ||
1da177e4 LT |
1404 | cb->dump = dump; |
1405 | cb->done = done; | |
1406 | cb->nlh = nlh; | |
1407 | atomic_inc(&skb->users); | |
1408 | cb->skb = skb; | |
1409 | ||
1410 | sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid); | |
1411 | if (sk == NULL) { | |
1412 | netlink_destroy_callback(cb); | |
1413 | return -ECONNREFUSED; | |
1414 | } | |
1415 | nlk = nlk_sk(sk); | |
1416 | /* A dump is in progress... */ | |
1417 | spin_lock(&nlk->cb_lock); | |
1418 | if (nlk->cb) { | |
1419 | spin_unlock(&nlk->cb_lock); | |
1420 | netlink_destroy_callback(cb); | |
1421 | sock_put(sk); | |
1422 | return -EBUSY; | |
1423 | } | |
1424 | nlk->cb = cb; | |
1da177e4 LT |
1425 | spin_unlock(&nlk->cb_lock); |
1426 | ||
1427 | netlink_dump(sk); | |
1428 | sock_put(sk); | |
1429 | return 0; | |
1430 | } | |
1431 | ||
1432 | void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) | |
1433 | { | |
1434 | struct sk_buff *skb; | |
1435 | struct nlmsghdr *rep; | |
1436 | struct nlmsgerr *errmsg; | |
1437 | int size; | |
1438 | ||
1439 | if (err == 0) | |
bf8b79e4 | 1440 | size = nlmsg_total_size(sizeof(*errmsg)); |
1da177e4 | 1441 | else |
bf8b79e4 | 1442 | size = nlmsg_total_size(sizeof(*errmsg) + nlmsg_len(nlh)); |
1da177e4 | 1443 | |
bf8b79e4 | 1444 | skb = nlmsg_new(size, GFP_KERNEL); |
1da177e4 LT |
1445 | if (!skb) { |
1446 | struct sock *sk; | |
1447 | ||
1448 | sk = netlink_lookup(in_skb->sk->sk_protocol, | |
1449 | NETLINK_CB(in_skb).pid); | |
1450 | if (sk) { | |
1451 | sk->sk_err = ENOBUFS; | |
1452 | sk->sk_error_report(sk); | |
1453 | sock_put(sk); | |
1454 | } | |
1455 | return; | |
1456 | } | |
1457 | ||
1458 | rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, | |
1797754e | 1459 | NLMSG_ERROR, sizeof(struct nlmsgerr), 0); |
bf8b79e4 | 1460 | errmsg = nlmsg_data(rep); |
1da177e4 | 1461 | errmsg->error = err; |
bf8b79e4 | 1462 | memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); |
1da177e4 LT |
1463 | netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); |
1464 | } | |
1465 | ||
82ace47a TG |
1466 | static int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, |
1467 | struct nlmsghdr *, int *)) | |
1468 | { | |
82ace47a TG |
1469 | struct nlmsghdr *nlh; |
1470 | int err; | |
1471 | ||
1472 | while (skb->len >= nlmsg_total_size(0)) { | |
1473 | nlh = (struct nlmsghdr *) skb->data; | |
1474 | ||
ad8e4b75 | 1475 | if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) |
82ace47a TG |
1476 | return 0; |
1477 | ||
82ace47a TG |
1478 | if (cb(skb, nlh, &err) < 0) { |
1479 | /* Not an error, but we have to interrupt processing | |
1480 | * here. Note: that in this case we do not pull | |
1481 | * message from skb, it will be processed later. | |
1482 | */ | |
1483 | if (err == 0) | |
1484 | return -1; | |
1485 | netlink_ack(skb, nlh, err); | |
1486 | } else if (nlh->nlmsg_flags & NLM_F_ACK) | |
1487 | netlink_ack(skb, nlh, 0); | |
1488 | ||
bf8b79e4 | 1489 | netlink_queue_skip(nlh, skb); |
82ace47a TG |
1490 | } |
1491 | ||
1492 | return 0; | |
1493 | } | |
1494 | ||
1495 | /** | |
1496 | * nelink_run_queue - Process netlink receive queue. | |
1497 | * @sk: Netlink socket containing the queue | |
1498 | * @qlen: Place to store queue length upon entry | |
1499 | * @cb: Callback function invoked for each netlink message found | |
1500 | * | |
1501 | * Processes as much as there was in the queue upon entry and invokes | |
1502 | * a callback function for each netlink message found. The callback | |
1503 | * function may refuse a message by returning a negative error code | |
1504 | * but setting the error pointer to 0 in which case this function | |
1505 | * returns with a qlen != 0. | |
1506 | * | |
1507 | * qlen must be initialized to 0 before the initial entry, afterwards | |
1508 | * the function may be called repeatedly until qlen reaches 0. | |
1509 | */ | |
1510 | void netlink_run_queue(struct sock *sk, unsigned int *qlen, | |
1511 | int (*cb)(struct sk_buff *, struct nlmsghdr *, int *)) | |
1512 | { | |
1513 | struct sk_buff *skb; | |
1514 | ||
1515 | if (!*qlen || *qlen > skb_queue_len(&sk->sk_receive_queue)) | |
1516 | *qlen = skb_queue_len(&sk->sk_receive_queue); | |
1517 | ||
1518 | for (; *qlen; (*qlen)--) { | |
1519 | skb = skb_dequeue(&sk->sk_receive_queue); | |
1520 | if (netlink_rcv_skb(skb, cb)) { | |
1521 | if (skb->len) | |
1522 | skb_queue_head(&sk->sk_receive_queue, skb); | |
1523 | else { | |
1524 | kfree_skb(skb); | |
1525 | (*qlen)--; | |
1526 | } | |
1527 | break; | |
1528 | } | |
1529 | ||
1530 | kfree_skb(skb); | |
1531 | } | |
1532 | } | |
1533 | ||
1534 | /** | |
1535 | * netlink_queue_skip - Skip netlink message while processing queue. | |
1536 | * @nlh: Netlink message to be skipped | |
1537 | * @skb: Socket buffer containing the netlink messages. | |
1538 | * | |
1539 | * Pulls the given netlink message off the socket buffer so the next | |
1540 | * call to netlink_queue_run() will not reconsider the message. | |
1541 | */ | |
1542 | void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb) | |
1543 | { | |
1544 | int msglen = NLMSG_ALIGN(nlh->nlmsg_len); | |
1545 | ||
1546 | if (msglen > skb->len) | |
1547 | msglen = skb->len; | |
1548 | ||
1549 | skb_pull(skb, msglen); | |
1550 | } | |
1da177e4 | 1551 | |
d387f6ad TG |
1552 | /** |
1553 | * nlmsg_notify - send a notification netlink message | |
1554 | * @sk: netlink socket to use | |
1555 | * @skb: notification message | |
1556 | * @pid: destination netlink pid for reports or 0 | |
1557 | * @group: destination multicast group or 0 | |
1558 | * @report: 1 to report back, 0 to disable | |
1559 | * @flags: allocation flags | |
1560 | */ | |
1561 | int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, | |
1562 | unsigned int group, int report, gfp_t flags) | |
1563 | { | |
1564 | int err = 0; | |
1565 | ||
1566 | if (group) { | |
1567 | int exclude_pid = 0; | |
1568 | ||
1569 | if (report) { | |
1570 | atomic_inc(&skb->users); | |
1571 | exclude_pid = pid; | |
1572 | } | |
1573 | ||
1574 | /* errors reported via destination sk->sk_err */ | |
1575 | nlmsg_multicast(sk, skb, exclude_pid, group, flags); | |
1576 | } | |
1577 | ||
1578 | if (report) | |
1579 | err = nlmsg_unicast(sk, skb, pid); | |
1580 | ||
1581 | return err; | |
1582 | } | |
1583 | ||
1da177e4 LT |
1584 | #ifdef CONFIG_PROC_FS |
1585 | struct nl_seq_iter { | |
1586 | int link; | |
1587 | int hash_idx; | |
1588 | }; | |
1589 | ||
1590 | static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) | |
1591 | { | |
1592 | struct nl_seq_iter *iter = seq->private; | |
1593 | int i, j; | |
1594 | struct sock *s; | |
1595 | struct hlist_node *node; | |
1596 | loff_t off = 0; | |
1597 | ||
1598 | for (i=0; i<MAX_LINKS; i++) { | |
1599 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1600 | ||
1601 | for (j = 0; j <= hash->mask; j++) { | |
1602 | sk_for_each(s, node, &hash->table[j]) { | |
1603 | if (off == pos) { | |
1604 | iter->link = i; | |
1605 | iter->hash_idx = j; | |
1606 | return s; | |
1607 | } | |
1608 | ++off; | |
1609 | } | |
1610 | } | |
1611 | } | |
1612 | return NULL; | |
1613 | } | |
1614 | ||
1615 | static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) | |
1616 | { | |
1617 | read_lock(&nl_table_lock); | |
1618 | return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; | |
1619 | } | |
1620 | ||
1621 | static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
1622 | { | |
1623 | struct sock *s; | |
1624 | struct nl_seq_iter *iter; | |
1625 | int i, j; | |
1626 | ||
1627 | ++*pos; | |
1628 | ||
1629 | if (v == SEQ_START_TOKEN) | |
1630 | return netlink_seq_socket_idx(seq, 0); | |
1631 | ||
1632 | s = sk_next(v); | |
1633 | if (s) | |
1634 | return s; | |
1635 | ||
1636 | iter = seq->private; | |
1637 | i = iter->link; | |
1638 | j = iter->hash_idx + 1; | |
1639 | ||
1640 | do { | |
1641 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1642 | ||
1643 | for (; j <= hash->mask; j++) { | |
1644 | s = sk_head(&hash->table[j]); | |
1645 | if (s) { | |
1646 | iter->link = i; | |
1647 | iter->hash_idx = j; | |
1648 | return s; | |
1649 | } | |
1650 | } | |
1651 | ||
1652 | j = 0; | |
1653 | } while (++i < MAX_LINKS); | |
1654 | ||
1655 | return NULL; | |
1656 | } | |
1657 | ||
1658 | static void netlink_seq_stop(struct seq_file *seq, void *v) | |
1659 | { | |
1660 | read_unlock(&nl_table_lock); | |
1661 | } | |
1662 | ||
1663 | ||
1664 | static int netlink_seq_show(struct seq_file *seq, void *v) | |
1665 | { | |
1666 | if (v == SEQ_START_TOKEN) | |
1667 | seq_puts(seq, | |
1668 | "sk Eth Pid Groups " | |
1669 | "Rmem Wmem Dump Locks\n"); | |
1670 | else { | |
1671 | struct sock *s = v; | |
1672 | struct netlink_sock *nlk = nlk_sk(s); | |
1673 | ||
1674 | seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", | |
1675 | s, | |
1676 | s->sk_protocol, | |
1677 | nlk->pid, | |
513c2500 | 1678 | nlk->groups ? (u32)nlk->groups[0] : 0, |
1da177e4 LT |
1679 | atomic_read(&s->sk_rmem_alloc), |
1680 | atomic_read(&s->sk_wmem_alloc), | |
1681 | nlk->cb, | |
1682 | atomic_read(&s->sk_refcnt) | |
1683 | ); | |
1684 | ||
1685 | } | |
1686 | return 0; | |
1687 | } | |
1688 | ||
1689 | static struct seq_operations netlink_seq_ops = { | |
1690 | .start = netlink_seq_start, | |
1691 | .next = netlink_seq_next, | |
1692 | .stop = netlink_seq_stop, | |
1693 | .show = netlink_seq_show, | |
1694 | }; | |
1695 | ||
1696 | ||
1697 | static int netlink_seq_open(struct inode *inode, struct file *file) | |
1698 | { | |
1699 | struct seq_file *seq; | |
1700 | struct nl_seq_iter *iter; | |
1701 | int err; | |
1702 | ||
0da974f4 | 1703 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
1da177e4 LT |
1704 | if (!iter) |
1705 | return -ENOMEM; | |
1706 | ||
1707 | err = seq_open(file, &netlink_seq_ops); | |
1708 | if (err) { | |
1709 | kfree(iter); | |
1710 | return err; | |
1711 | } | |
1712 | ||
1da177e4 LT |
1713 | seq = file->private_data; |
1714 | seq->private = iter; | |
1715 | return 0; | |
1716 | } | |
1717 | ||
1718 | static struct file_operations netlink_seq_fops = { | |
1719 | .owner = THIS_MODULE, | |
1720 | .open = netlink_seq_open, | |
1721 | .read = seq_read, | |
1722 | .llseek = seq_lseek, | |
1723 | .release = seq_release_private, | |
1724 | }; | |
1725 | ||
1726 | #endif | |
1727 | ||
1728 | int netlink_register_notifier(struct notifier_block *nb) | |
1729 | { | |
e041c683 | 1730 | return atomic_notifier_chain_register(&netlink_chain, nb); |
1da177e4 LT |
1731 | } |
1732 | ||
1733 | int netlink_unregister_notifier(struct notifier_block *nb) | |
1734 | { | |
e041c683 | 1735 | return atomic_notifier_chain_unregister(&netlink_chain, nb); |
1da177e4 LT |
1736 | } |
1737 | ||
90ddc4f0 | 1738 | static const struct proto_ops netlink_ops = { |
1da177e4 LT |
1739 | .family = PF_NETLINK, |
1740 | .owner = THIS_MODULE, | |
1741 | .release = netlink_release, | |
1742 | .bind = netlink_bind, | |
1743 | .connect = netlink_connect, | |
1744 | .socketpair = sock_no_socketpair, | |
1745 | .accept = sock_no_accept, | |
1746 | .getname = netlink_getname, | |
1747 | .poll = datagram_poll, | |
1748 | .ioctl = sock_no_ioctl, | |
1749 | .listen = sock_no_listen, | |
1750 | .shutdown = sock_no_shutdown, | |
9a4595bc PM |
1751 | .setsockopt = netlink_setsockopt, |
1752 | .getsockopt = netlink_getsockopt, | |
1da177e4 LT |
1753 | .sendmsg = netlink_sendmsg, |
1754 | .recvmsg = netlink_recvmsg, | |
1755 | .mmap = sock_no_mmap, | |
1756 | .sendpage = sock_no_sendpage, | |
1757 | }; | |
1758 | ||
1759 | static struct net_proto_family netlink_family_ops = { | |
1760 | .family = PF_NETLINK, | |
1761 | .create = netlink_create, | |
1762 | .owner = THIS_MODULE, /* for consistency 8) */ | |
1763 | }; | |
1764 | ||
1765 | extern void netlink_skb_parms_too_large(void); | |
1766 | ||
1767 | static int __init netlink_proto_init(void) | |
1768 | { | |
1769 | struct sk_buff *dummy_skb; | |
1770 | int i; | |
1771 | unsigned long max; | |
1772 | unsigned int order; | |
1773 | int err = proto_register(&netlink_proto, 0); | |
1774 | ||
1775 | if (err != 0) | |
1776 | goto out; | |
1777 | ||
1778 | if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)) | |
1779 | netlink_skb_parms_too_large(); | |
1780 | ||
0da974f4 | 1781 | nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); |
fab2caf6 AM |
1782 | if (!nl_table) |
1783 | goto panic; | |
1da177e4 | 1784 | |
1da177e4 LT |
1785 | if (num_physpages >= (128 * 1024)) |
1786 | max = num_physpages >> (21 - PAGE_SHIFT); | |
1787 | else | |
1788 | max = num_physpages >> (23 - PAGE_SHIFT); | |
1789 | ||
1790 | order = get_bitmask_order(max) - 1 + PAGE_SHIFT; | |
1791 | max = (1UL << order) / sizeof(struct hlist_head); | |
1792 | order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1; | |
1793 | ||
1794 | for (i = 0; i < MAX_LINKS; i++) { | |
1795 | struct nl_pid_hash *hash = &nl_table[i].hash; | |
1796 | ||
1797 | hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table)); | |
1798 | if (!hash->table) { | |
1799 | while (i-- > 0) | |
1800 | nl_pid_hash_free(nl_table[i].hash.table, | |
1801 | 1 * sizeof(*hash->table)); | |
1802 | kfree(nl_table); | |
fab2caf6 | 1803 | goto panic; |
1da177e4 LT |
1804 | } |
1805 | memset(hash->table, 0, 1 * sizeof(*hash->table)); | |
1806 | hash->max_shift = order; | |
1807 | hash->shift = 0; | |
1808 | hash->mask = 0; | |
1809 | hash->rehash_time = jiffies; | |
1810 | } | |
1811 | ||
1812 | sock_register(&netlink_family_ops); | |
1813 | #ifdef CONFIG_PROC_FS | |
1814 | proc_net_fops_create("netlink", 0, &netlink_seq_fops); | |
1815 | #endif | |
1816 | /* The netlink device handler may be needed early. */ | |
1817 | rtnetlink_init(); | |
1818 | out: | |
1819 | return err; | |
fab2caf6 AM |
1820 | panic: |
1821 | panic("netlink_init: Cannot allocate nl_table\n"); | |
1da177e4 LT |
1822 | } |
1823 | ||
1da177e4 | 1824 | core_initcall(netlink_proto_init); |
1da177e4 LT |
1825 | |
1826 | EXPORT_SYMBOL(netlink_ack); | |
82ace47a TG |
1827 | EXPORT_SYMBOL(netlink_run_queue); |
1828 | EXPORT_SYMBOL(netlink_queue_skip); | |
1da177e4 LT |
1829 | EXPORT_SYMBOL(netlink_broadcast); |
1830 | EXPORT_SYMBOL(netlink_dump_start); | |
1831 | EXPORT_SYMBOL(netlink_kernel_create); | |
1832 | EXPORT_SYMBOL(netlink_register_notifier); | |
1833 | EXPORT_SYMBOL(netlink_set_err); | |
1834 | EXPORT_SYMBOL(netlink_set_nonroot); | |
1835 | EXPORT_SYMBOL(netlink_unicast); | |
1836 | EXPORT_SYMBOL(netlink_unregister_notifier); | |
d387f6ad | 1837 | EXPORT_SYMBOL(nlmsg_notify); |