bluetooth: fix race in bt_procfs_init()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / bluetooth / af_bluetooth.c
1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2000-2001 Qualcomm Incorporated
4
5 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License version 2 as
9 published by the Free Software Foundation;
10
11 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
12 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
13 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
14 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
15 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
16 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19
20 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
21 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
22 SOFTWARE IS DISCLAIMED.
23 */
24
25 /* Bluetooth address family and sockets. */
26
27 #include <linux/module.h>
28 #include <asm/ioctls.h>
29
30 #include <net/bluetooth/bluetooth.h>
31 #include <linux/proc_fs.h>
32
33 #define VERSION "2.16"
34
35 /* Bluetooth sockets */
36 #define BT_MAX_PROTO 8
37 static const struct net_proto_family *bt_proto[BT_MAX_PROTO];
38 static DEFINE_RWLOCK(bt_proto_lock);
39
40 static struct lock_class_key bt_lock_key[BT_MAX_PROTO];
41 static const char *const bt_key_strings[BT_MAX_PROTO] = {
42 "sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP",
43 "sk_lock-AF_BLUETOOTH-BTPROTO_HCI",
44 "sk_lock-AF_BLUETOOTH-BTPROTO_SCO",
45 "sk_lock-AF_BLUETOOTH-BTPROTO_RFCOMM",
46 "sk_lock-AF_BLUETOOTH-BTPROTO_BNEP",
47 "sk_lock-AF_BLUETOOTH-BTPROTO_CMTP",
48 "sk_lock-AF_BLUETOOTH-BTPROTO_HIDP",
49 "sk_lock-AF_BLUETOOTH-BTPROTO_AVDTP",
50 };
51
52 static struct lock_class_key bt_slock_key[BT_MAX_PROTO];
53 static const char *const bt_slock_key_strings[BT_MAX_PROTO] = {
54 "slock-AF_BLUETOOTH-BTPROTO_L2CAP",
55 "slock-AF_BLUETOOTH-BTPROTO_HCI",
56 "slock-AF_BLUETOOTH-BTPROTO_SCO",
57 "slock-AF_BLUETOOTH-BTPROTO_RFCOMM",
58 "slock-AF_BLUETOOTH-BTPROTO_BNEP",
59 "slock-AF_BLUETOOTH-BTPROTO_CMTP",
60 "slock-AF_BLUETOOTH-BTPROTO_HIDP",
61 "slock-AF_BLUETOOTH-BTPROTO_AVDTP",
62 };
63
64 void bt_sock_reclassify_lock(struct sock *sk, int proto)
65 {
66 BUG_ON(!sk);
67 BUG_ON(sock_owned_by_user(sk));
68
69 sock_lock_init_class_and_name(sk,
70 bt_slock_key_strings[proto], &bt_slock_key[proto],
71 bt_key_strings[proto], &bt_lock_key[proto]);
72 }
73 EXPORT_SYMBOL(bt_sock_reclassify_lock);
74
75 int bt_sock_register(int proto, const struct net_proto_family *ops)
76 {
77 int err = 0;
78
79 if (proto < 0 || proto >= BT_MAX_PROTO)
80 return -EINVAL;
81
82 write_lock(&bt_proto_lock);
83
84 if (bt_proto[proto])
85 err = -EEXIST;
86 else
87 bt_proto[proto] = ops;
88
89 write_unlock(&bt_proto_lock);
90
91 return err;
92 }
93 EXPORT_SYMBOL(bt_sock_register);
94
95 int bt_sock_unregister(int proto)
96 {
97 int err = 0;
98
99 if (proto < 0 || proto >= BT_MAX_PROTO)
100 return -EINVAL;
101
102 write_lock(&bt_proto_lock);
103
104 if (!bt_proto[proto])
105 err = -ENOENT;
106 else
107 bt_proto[proto] = NULL;
108
109 write_unlock(&bt_proto_lock);
110
111 return err;
112 }
113 EXPORT_SYMBOL(bt_sock_unregister);
114
115 static int bt_sock_create(struct net *net, struct socket *sock, int proto,
116 int kern)
117 {
118 int err;
119
120 if (net != &init_net)
121 return -EAFNOSUPPORT;
122
123 if (proto < 0 || proto >= BT_MAX_PROTO)
124 return -EINVAL;
125
126 if (!bt_proto[proto])
127 request_module("bt-proto-%d", proto);
128
129 err = -EPROTONOSUPPORT;
130
131 read_lock(&bt_proto_lock);
132
133 if (bt_proto[proto] && try_module_get(bt_proto[proto]->owner)) {
134 err = bt_proto[proto]->create(net, sock, proto, kern);
135 if (!err)
136 bt_sock_reclassify_lock(sock->sk, proto);
137 module_put(bt_proto[proto]->owner);
138 }
139
140 read_unlock(&bt_proto_lock);
141
142 return err;
143 }
144
145 void bt_sock_link(struct bt_sock_list *l, struct sock *sk)
146 {
147 write_lock(&l->lock);
148 sk_add_node(sk, &l->head);
149 write_unlock(&l->lock);
150 }
151 EXPORT_SYMBOL(bt_sock_link);
152
153 void bt_sock_unlink(struct bt_sock_list *l, struct sock *sk)
154 {
155 write_lock(&l->lock);
156 sk_del_node_init(sk);
157 write_unlock(&l->lock);
158 }
159 EXPORT_SYMBOL(bt_sock_unlink);
160
161 void bt_accept_enqueue(struct sock *parent, struct sock *sk)
162 {
163 BT_DBG("parent %p, sk %p", parent, sk);
164
165 sock_hold(sk);
166 list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q);
167 bt_sk(sk)->parent = parent;
168 parent->sk_ack_backlog++;
169 }
170 EXPORT_SYMBOL(bt_accept_enqueue);
171
172 void bt_accept_unlink(struct sock *sk)
173 {
174 BT_DBG("sk %p state %d", sk, sk->sk_state);
175
176 list_del_init(&bt_sk(sk)->accept_q);
177 bt_sk(sk)->parent->sk_ack_backlog--;
178 bt_sk(sk)->parent = NULL;
179 sock_put(sk);
180 }
181 EXPORT_SYMBOL(bt_accept_unlink);
182
183 struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
184 {
185 struct list_head *p, *n;
186 struct sock *sk;
187
188 BT_DBG("parent %p", parent);
189
190 list_for_each_safe(p, n, &bt_sk(parent)->accept_q) {
191 sk = (struct sock *) list_entry(p, struct bt_sock, accept_q);
192
193 lock_sock(sk);
194
195 /* FIXME: Is this check still needed */
196 if (sk->sk_state == BT_CLOSED) {
197 release_sock(sk);
198 bt_accept_unlink(sk);
199 continue;
200 }
201
202 if (sk->sk_state == BT_CONNECTED || !newsock ||
203 test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags)) {
204 bt_accept_unlink(sk);
205 if (newsock)
206 sock_graft(sk, newsock);
207
208 release_sock(sk);
209 return sk;
210 }
211
212 release_sock(sk);
213 }
214
215 return NULL;
216 }
217 EXPORT_SYMBOL(bt_accept_dequeue);
218
219 int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
220 struct msghdr *msg, size_t len, int flags)
221 {
222 int noblock = flags & MSG_DONTWAIT;
223 struct sock *sk = sock->sk;
224 struct sk_buff *skb;
225 size_t copied;
226 int err;
227
228 BT_DBG("sock %p sk %p len %zu", sock, sk, len);
229
230 if (flags & (MSG_OOB))
231 return -EOPNOTSUPP;
232
233 skb = skb_recv_datagram(sk, flags, noblock, &err);
234 if (!skb) {
235 if (sk->sk_shutdown & RCV_SHUTDOWN)
236 return 0;
237 return err;
238 }
239
240 msg->msg_namelen = 0;
241
242 copied = skb->len;
243 if (len < copied) {
244 msg->msg_flags |= MSG_TRUNC;
245 copied = len;
246 }
247
248 skb_reset_transport_header(skb);
249 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
250 if (err == 0)
251 sock_recv_ts_and_drops(msg, sk, skb);
252
253 skb_free_datagram(sk, skb);
254
255 return err ? : copied;
256 }
257 EXPORT_SYMBOL(bt_sock_recvmsg);
258
259 static long bt_sock_data_wait(struct sock *sk, long timeo)
260 {
261 DECLARE_WAITQUEUE(wait, current);
262
263 add_wait_queue(sk_sleep(sk), &wait);
264 for (;;) {
265 set_current_state(TASK_INTERRUPTIBLE);
266
267 if (!skb_queue_empty(&sk->sk_receive_queue))
268 break;
269
270 if (sk->sk_err || (sk->sk_shutdown & RCV_SHUTDOWN))
271 break;
272
273 if (signal_pending(current) || !timeo)
274 break;
275
276 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
277 release_sock(sk);
278 timeo = schedule_timeout(timeo);
279 lock_sock(sk);
280 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
281 }
282
283 __set_current_state(TASK_RUNNING);
284 remove_wait_queue(sk_sleep(sk), &wait);
285 return timeo;
286 }
287
288 int bt_sock_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
289 struct msghdr *msg, size_t size, int flags)
290 {
291 struct sock *sk = sock->sk;
292 int err = 0;
293 size_t target, copied = 0;
294 long timeo;
295
296 if (flags & MSG_OOB)
297 return -EOPNOTSUPP;
298
299 msg->msg_namelen = 0;
300
301 BT_DBG("sk %p size %zu", sk, size);
302
303 lock_sock(sk);
304
305 target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
306 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
307
308 do {
309 struct sk_buff *skb;
310 int chunk;
311
312 skb = skb_dequeue(&sk->sk_receive_queue);
313 if (!skb) {
314 if (copied >= target)
315 break;
316
317 err = sock_error(sk);
318 if (err)
319 break;
320 if (sk->sk_shutdown & RCV_SHUTDOWN)
321 break;
322
323 err = -EAGAIN;
324 if (!timeo)
325 break;
326
327 timeo = bt_sock_data_wait(sk, timeo);
328
329 if (signal_pending(current)) {
330 err = sock_intr_errno(timeo);
331 goto out;
332 }
333 continue;
334 }
335
336 chunk = min_t(unsigned int, skb->len, size);
337 if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, chunk)) {
338 skb_queue_head(&sk->sk_receive_queue, skb);
339 if (!copied)
340 copied = -EFAULT;
341 break;
342 }
343 copied += chunk;
344 size -= chunk;
345
346 sock_recv_ts_and_drops(msg, sk, skb);
347
348 if (!(flags & MSG_PEEK)) {
349 int skb_len = skb_headlen(skb);
350
351 if (chunk <= skb_len) {
352 __skb_pull(skb, chunk);
353 } else {
354 struct sk_buff *frag;
355
356 __skb_pull(skb, skb_len);
357 chunk -= skb_len;
358
359 skb_walk_frags(skb, frag) {
360 if (chunk <= frag->len) {
361 /* Pulling partial data */
362 skb->len -= chunk;
363 skb->data_len -= chunk;
364 __skb_pull(frag, chunk);
365 break;
366 } else if (frag->len) {
367 /* Pulling all frag data */
368 chunk -= frag->len;
369 skb->len -= frag->len;
370 skb->data_len -= frag->len;
371 __skb_pull(frag, frag->len);
372 }
373 }
374 }
375
376 if (skb->len) {
377 skb_queue_head(&sk->sk_receive_queue, skb);
378 break;
379 }
380 kfree_skb(skb);
381
382 } else {
383 /* put message back and return */
384 skb_queue_head(&sk->sk_receive_queue, skb);
385 break;
386 }
387 } while (size);
388
389 out:
390 release_sock(sk);
391 return copied ? : err;
392 }
393 EXPORT_SYMBOL(bt_sock_stream_recvmsg);
394
395 static inline unsigned int bt_accept_poll(struct sock *parent)
396 {
397 struct list_head *p, *n;
398 struct sock *sk;
399
400 list_for_each_safe(p, n, &bt_sk(parent)->accept_q) {
401 sk = (struct sock *) list_entry(p, struct bt_sock, accept_q);
402 if (sk->sk_state == BT_CONNECTED ||
403 (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) &&
404 sk->sk_state == BT_CONNECT2))
405 return POLLIN | POLLRDNORM;
406 }
407
408 return 0;
409 }
410
411 unsigned int bt_sock_poll(struct file *file, struct socket *sock,
412 poll_table *wait)
413 {
414 struct sock *sk = sock->sk;
415 unsigned int mask = 0;
416
417 BT_DBG("sock %p, sk %p", sock, sk);
418
419 poll_wait(file, sk_sleep(sk), wait);
420
421 if (sk->sk_state == BT_LISTEN)
422 return bt_accept_poll(sk);
423
424 if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
425 mask |= POLLERR;
426
427 if (sk->sk_shutdown & RCV_SHUTDOWN)
428 mask |= POLLRDHUP | POLLIN | POLLRDNORM;
429
430 if (sk->sk_shutdown == SHUTDOWN_MASK)
431 mask |= POLLHUP;
432
433 if (!skb_queue_empty(&sk->sk_receive_queue))
434 mask |= POLLIN | POLLRDNORM;
435
436 if (sk->sk_state == BT_CLOSED)
437 mask |= POLLHUP;
438
439 if (sk->sk_state == BT_CONNECT ||
440 sk->sk_state == BT_CONNECT2 ||
441 sk->sk_state == BT_CONFIG)
442 return mask;
443
444 if (!test_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags) && sock_writeable(sk))
445 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
446 else
447 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
448
449 return mask;
450 }
451 EXPORT_SYMBOL(bt_sock_poll);
452
453 int bt_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
454 {
455 struct sock *sk = sock->sk;
456 struct sk_buff *skb;
457 long amount;
458 int err;
459
460 BT_DBG("sk %p cmd %x arg %lx", sk, cmd, arg);
461
462 switch (cmd) {
463 case TIOCOUTQ:
464 if (sk->sk_state == BT_LISTEN)
465 return -EINVAL;
466
467 amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
468 if (amount < 0)
469 amount = 0;
470 err = put_user(amount, (int __user *) arg);
471 break;
472
473 case TIOCINQ:
474 if (sk->sk_state == BT_LISTEN)
475 return -EINVAL;
476
477 lock_sock(sk);
478 skb = skb_peek(&sk->sk_receive_queue);
479 amount = skb ? skb->len : 0;
480 release_sock(sk);
481 err = put_user(amount, (int __user *) arg);
482 break;
483
484 case SIOCGSTAMP:
485 err = sock_get_timestamp(sk, (struct timeval __user *) arg);
486 break;
487
488 case SIOCGSTAMPNS:
489 err = sock_get_timestampns(sk, (struct timespec __user *) arg);
490 break;
491
492 default:
493 err = -ENOIOCTLCMD;
494 break;
495 }
496
497 return err;
498 }
499 EXPORT_SYMBOL(bt_sock_ioctl);
500
501 int bt_sock_wait_state(struct sock *sk, int state, unsigned long timeo)
502 {
503 DECLARE_WAITQUEUE(wait, current);
504 int err = 0;
505
506 BT_DBG("sk %p", sk);
507
508 add_wait_queue(sk_sleep(sk), &wait);
509 set_current_state(TASK_INTERRUPTIBLE);
510 while (sk->sk_state != state) {
511 if (!timeo) {
512 err = -EINPROGRESS;
513 break;
514 }
515
516 if (signal_pending(current)) {
517 err = sock_intr_errno(timeo);
518 break;
519 }
520
521 release_sock(sk);
522 timeo = schedule_timeout(timeo);
523 lock_sock(sk);
524 set_current_state(TASK_INTERRUPTIBLE);
525
526 err = sock_error(sk);
527 if (err)
528 break;
529 }
530 __set_current_state(TASK_RUNNING);
531 remove_wait_queue(sk_sleep(sk), &wait);
532 return err;
533 }
534 EXPORT_SYMBOL(bt_sock_wait_state);
535
536 #ifdef CONFIG_PROC_FS
537 struct bt_seq_state {
538 struct bt_sock_list *l;
539 };
540
541 static void *bt_seq_start(struct seq_file *seq, loff_t *pos)
542 __acquires(seq->private->l->lock)
543 {
544 struct bt_seq_state *s = seq->private;
545 struct bt_sock_list *l = s->l;
546
547 read_lock(&l->lock);
548 return seq_hlist_start_head(&l->head, *pos);
549 }
550
551 static void *bt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
552 {
553 struct bt_seq_state *s = seq->private;
554 struct bt_sock_list *l = s->l;
555
556 return seq_hlist_next(v, &l->head, pos);
557 }
558
559 static void bt_seq_stop(struct seq_file *seq, void *v)
560 __releases(seq->private->l->lock)
561 {
562 struct bt_seq_state *s = seq->private;
563 struct bt_sock_list *l = s->l;
564
565 read_unlock(&l->lock);
566 }
567
568 static int bt_seq_show(struct seq_file *seq, void *v)
569 {
570 struct bt_seq_state *s = seq->private;
571 struct bt_sock_list *l = s->l;
572
573 if (v == SEQ_START_TOKEN) {
574 seq_puts(seq ,"sk RefCnt Rmem Wmem User Inode Src Dst Parent");
575
576 if (l->custom_seq_show) {
577 seq_putc(seq, ' ');
578 l->custom_seq_show(seq, v);
579 }
580
581 seq_putc(seq, '\n');
582 } else {
583 struct sock *sk = sk_entry(v);
584 struct bt_sock *bt = bt_sk(sk);
585
586 seq_printf(seq,
587 "%pK %-6d %-6u %-6u %-6u %-6lu %pMR %pMR %-6lu",
588 sk,
589 atomic_read(&sk->sk_refcnt),
590 sk_rmem_alloc_get(sk),
591 sk_wmem_alloc_get(sk),
592 from_kuid(seq_user_ns(seq), sock_i_uid(sk)),
593 sock_i_ino(sk),
594 &bt->src,
595 &bt->dst,
596 bt->parent? sock_i_ino(bt->parent): 0LU);
597
598 if (l->custom_seq_show) {
599 seq_putc(seq, ' ');
600 l->custom_seq_show(seq, v);
601 }
602
603 seq_putc(seq, '\n');
604 }
605 return 0;
606 }
607
608 static struct seq_operations bt_seq_ops = {
609 .start = bt_seq_start,
610 .next = bt_seq_next,
611 .stop = bt_seq_stop,
612 .show = bt_seq_show,
613 };
614
615 static int bt_seq_open(struct inode *inode, struct file *file)
616 {
617 struct bt_sock_list *sk_list;
618 struct bt_seq_state *s;
619
620 sk_list = PDE_DATA(inode);
621 s = __seq_open_private(file, &bt_seq_ops,
622 sizeof(struct bt_seq_state));
623 if (!s)
624 return -ENOMEM;
625
626 s->l = sk_list;
627 return 0;
628 }
629
630 static const struct file_operations bt_fops = {
631 .open = bt_seq_open,
632 .read = seq_read,
633 .llseek = seq_lseek,
634 .release = seq_release_private
635 };
636
637 int bt_procfs_init(struct net *net, const char *name,
638 struct bt_sock_list* sk_list,
639 int (* seq_show)(struct seq_file *, void *))
640 {
641 sk_list->custom_seq_show = seq_show;
642
643 if (!proc_create_data(name, 0, net->proc_net, &bt_fops, sk_list))
644 return -ENOMEM;
645 return 0;
646 }
647
648 void bt_procfs_cleanup(struct net *net, const char *name)
649 {
650 remove_proc_entry(name, net->proc_net);
651 }
652 #else
653 int bt_procfs_init(struct net *net, const char *name,
654 struct bt_sock_list* sk_list,
655 int (* seq_show)(struct seq_file *, void *))
656 {
657 return 0;
658 }
659
660 void bt_procfs_cleanup(struct net *net, const char *name)
661 {
662 }
663 #endif
664 EXPORT_SYMBOL(bt_procfs_init);
665 EXPORT_SYMBOL(bt_procfs_cleanup);
666
667 static struct net_proto_family bt_sock_family_ops = {
668 .owner = THIS_MODULE,
669 .family = PF_BLUETOOTH,
670 .create = bt_sock_create,
671 };
672
673 static int __init bt_init(void)
674 {
675 int err;
676
677 BT_INFO("Core ver %s", VERSION);
678
679 err = bt_sysfs_init();
680 if (err < 0)
681 return err;
682
683 err = sock_register(&bt_sock_family_ops);
684 if (err < 0) {
685 bt_sysfs_cleanup();
686 return err;
687 }
688
689 BT_INFO("HCI device and connection manager initialized");
690
691 err = hci_sock_init();
692 if (err < 0)
693 goto error;
694
695 err = l2cap_init();
696 if (err < 0)
697 goto sock_err;
698
699 err = sco_init();
700 if (err < 0) {
701 l2cap_exit();
702 goto sock_err;
703 }
704
705 return 0;
706
707 sock_err:
708 hci_sock_cleanup();
709
710 error:
711 sock_unregister(PF_BLUETOOTH);
712 bt_sysfs_cleanup();
713
714 return err;
715 }
716
717 static void __exit bt_exit(void)
718 {
719
720 sco_exit();
721
722 l2cap_exit();
723
724 hci_sock_cleanup();
725
726 sock_unregister(PF_BLUETOOTH);
727
728 bt_sysfs_cleanup();
729 }
730
731 subsys_initcall(bt_init);
732 module_exit(bt_exit);
733
734 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
735 MODULE_DESCRIPTION("Bluetooth Core ver " VERSION);
736 MODULE_VERSION(VERSION);
737 MODULE_LICENSE("GPL");
738 MODULE_ALIAS_NETPROTO(PF_BLUETOOTH);