1 /*
2 BlueZ - Bluetooth protocol stack for Linux
3 Copyright (C) 2000-2001 Qualcomm Incorporated
4 Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
5 Copyright (C) 2010 Google Inc.
6 Copyright (C) 2011 ProFUSION Embedded Systems
7
8 Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
9
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License version 2 as
12 published by the Free Software Foundation;
13
14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
17 IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
18 CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
21 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22
23 ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
24 COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
25 SOFTWARE IS DISCLAIMED.
26 */
27
28 /* Bluetooth L2CAP sockets. */
29
30 #include <linux/module.h>
31 #include <linux/export.h>
32 #include <linux/filter.h>
33 #include <linux/sched/signal.h>
34
35 #include <net/bluetooth/bluetooth.h>
36 #include <net/bluetooth/hci_core.h>
37 #include <net/bluetooth/l2cap.h>
38
39 #include "smp.h"
40
41 static struct bt_sock_list l2cap_sk_list = {
42 .lock = __RW_LOCK_UNLOCKED(l2cap_sk_list.lock)
43 };
44
45 static const struct proto_ops l2cap_sock_ops;
46 static void l2cap_sock_init(struct sock *sk, struct sock *parent);
47 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
48 int proto, gfp_t prio, int kern);
49 static void l2cap_sock_cleanup_listen(struct sock *parent);
50
l2cap_is_socket(struct socket * sock)51 bool l2cap_is_socket(struct socket *sock)
52 {
53 return sock && sock->ops == &l2cap_sock_ops;
54 }
55 EXPORT_SYMBOL(l2cap_is_socket);
56
l2cap_validate_bredr_psm(u16 psm)57 static int l2cap_validate_bredr_psm(u16 psm)
58 {
59 /* PSM must be odd and lsb of upper byte must be 0 */
60 if ((psm & 0x0101) != 0x0001)
61 return -EINVAL;
62
63 /* Restrict usage of well-known PSMs */
64 if (psm < L2CAP_PSM_DYN_START && !capable(CAP_NET_BIND_SERVICE))
65 return -EACCES;
66
67 return 0;
68 }
69
l2cap_validate_le_psm(u16 psm)70 static int l2cap_validate_le_psm(u16 psm)
71 {
72 /* Valid LE_PSM ranges are defined only until 0x00ff */
73 if (psm > L2CAP_PSM_LE_DYN_END)
74 return -EINVAL;
75
76 /* Restrict fixed, SIG assigned PSM values to CAP_NET_BIND_SERVICE */
77 if (psm < L2CAP_PSM_LE_DYN_START && !capable(CAP_NET_BIND_SERVICE))
78 return -EACCES;
79
80 return 0;
81 }
82
l2cap_sock_bind(struct socket * sock,struct sockaddr * addr,int alen)83 static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
84 {
85 struct sock *sk = sock->sk;
86 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
87 struct sockaddr_l2 la;
88 int len, err = 0;
89
90 BT_DBG("sk %p", sk);
91
92 if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
93 addr->sa_family != AF_BLUETOOTH)
94 return -EINVAL;
95
96 memset(&la, 0, sizeof(la));
97 len = min_t(unsigned int, sizeof(la), alen);
98 memcpy(&la, addr, len);
99
100 if (la.l2_cid && la.l2_psm)
101 return -EINVAL;
102
103 if (!bdaddr_type_is_valid(la.l2_bdaddr_type))
104 return -EINVAL;
105
106 if (bdaddr_type_is_le(la.l2_bdaddr_type)) {
107 /* We only allow ATT user space socket */
108 if (la.l2_cid &&
109 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
110 return -EINVAL;
111 }
112
113 lock_sock(sk);
114
115 if (sk->sk_state != BT_OPEN) {
116 err = -EBADFD;
117 goto done;
118 }
119
120 if (la.l2_psm) {
121 __u16 psm = __le16_to_cpu(la.l2_psm);
122
123 if (la.l2_bdaddr_type == BDADDR_BREDR)
124 err = l2cap_validate_bredr_psm(psm);
125 else
126 err = l2cap_validate_le_psm(psm);
127
128 if (err)
129 goto done;
130 }
131
132 bacpy(&chan->src, &la.l2_bdaddr);
133 chan->src_type = la.l2_bdaddr_type;
134
135 if (la.l2_cid)
136 err = l2cap_add_scid(chan, __le16_to_cpu(la.l2_cid));
137 else
138 err = l2cap_add_psm(chan, &la.l2_bdaddr, la.l2_psm);
139
140 if (err < 0)
141 goto done;
142
143 switch (chan->chan_type) {
144 case L2CAP_CHAN_CONN_LESS:
145 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_3DSP)
146 chan->sec_level = BT_SECURITY_SDP;
147 break;
148 case L2CAP_CHAN_CONN_ORIENTED:
149 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_SDP ||
150 __le16_to_cpu(la.l2_psm) == L2CAP_PSM_RFCOMM)
151 chan->sec_level = BT_SECURITY_SDP;
152 break;
153 case L2CAP_CHAN_RAW:
154 chan->sec_level = BT_SECURITY_SDP;
155 break;
156 case L2CAP_CHAN_FIXED:
157 /* Fixed channels default to the L2CAP core not holding a
158 * hci_conn reference for them. For fixed channels mapping to
159 * L2CAP sockets we do want to hold a reference so set the
160 * appropriate flag to request it.
161 */
162 set_bit(FLAG_HOLD_HCI_CONN, &chan->flags);
163 break;
164 }
165
166 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and
167 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set.
168 */
169 if (chan->psm && bdaddr_type_is_le(chan->src_type) &&
170 chan->mode != L2CAP_MODE_EXT_FLOWCTL)
171 chan->mode = L2CAP_MODE_LE_FLOWCTL;
172
173 chan->state = BT_BOUND;
174 sk->sk_state = BT_BOUND;
175
176 done:
177 release_sock(sk);
178 return err;
179 }
180
l2cap_sock_connect(struct socket * sock,struct sockaddr * addr,int alen,int flags)181 static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
182 int alen, int flags)
183 {
184 struct sock *sk = sock->sk;
185 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
186 struct sockaddr_l2 la;
187 int len, err = 0;
188 bool zapped;
189
190 BT_DBG("sk %p", sk);
191
192 lock_sock(sk);
193 zapped = sock_flag(sk, SOCK_ZAPPED);
194 release_sock(sk);
195
196 if (zapped)
197 return -EINVAL;
198
199 if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
200 addr->sa_family != AF_BLUETOOTH)
201 return -EINVAL;
202
203 memset(&la, 0, sizeof(la));
204 len = min_t(unsigned int, sizeof(la), alen);
205 memcpy(&la, addr, len);
206
207 if (la.l2_cid && la.l2_psm)
208 return -EINVAL;
209
210 if (!bdaddr_type_is_valid(la.l2_bdaddr_type))
211 return -EINVAL;
212
213 /* Check that the socket wasn't bound to something that
214 * conflicts with the address given to connect(). If chan->src
215 * is BDADDR_ANY it means bind() was never used, in which case
216 * chan->src_type and la.l2_bdaddr_type do not need to match.
217 */
218 if (chan->src_type == BDADDR_BREDR && bacmp(&chan->src, BDADDR_ANY) &&
219 bdaddr_type_is_le(la.l2_bdaddr_type)) {
220 /* Old user space versions will try to incorrectly bind
221 * the ATT socket using BDADDR_BREDR. We need to accept
222 * this and fix up the source address type only when
223 * both the source CID and destination CID indicate
224 * ATT. Anything else is an invalid combination.
225 */
226 if (chan->scid != L2CAP_CID_ATT ||
227 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
228 return -EINVAL;
229
230 /* We don't have the hdev available here to make a
231 * better decision on random vs public, but since all
232 * user space versions that exhibit this issue anyway do
233 * not support random local addresses assuming public
234 * here is good enough.
235 */
236 chan->src_type = BDADDR_LE_PUBLIC;
237 }
238
239 if (chan->src_type != BDADDR_BREDR && la.l2_bdaddr_type == BDADDR_BREDR)
240 return -EINVAL;
241
242 if (bdaddr_type_is_le(la.l2_bdaddr_type)) {
243 /* We only allow ATT user space socket */
244 if (la.l2_cid &&
245 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
246 return -EINVAL;
247 }
248
249 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and
250 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set.
251 */
252 if (chan->psm && bdaddr_type_is_le(chan->src_type) &&
253 chan->mode != L2CAP_MODE_EXT_FLOWCTL)
254 chan->mode = L2CAP_MODE_LE_FLOWCTL;
255
256 err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid),
257 &la.l2_bdaddr, la.l2_bdaddr_type,
258 sk->sk_sndtimeo);
259 if (err)
260 return err;
261
262 lock_sock(sk);
263
264 err = bt_sock_wait_state(sk, BT_CONNECTED,
265 sock_sndtimeo(sk, flags & O_NONBLOCK));
266
267 release_sock(sk);
268
269 return err;
270 }
271
l2cap_sock_listen(struct socket * sock,int backlog)272 static int l2cap_sock_listen(struct socket *sock, int backlog)
273 {
274 struct sock *sk = sock->sk;
275 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
276 int err = 0;
277
278 BT_DBG("sk %p backlog %d", sk, backlog);
279
280 lock_sock(sk);
281
282 if (sk->sk_state != BT_BOUND) {
283 err = -EBADFD;
284 goto done;
285 }
286
287 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM) {
288 err = -EINVAL;
289 goto done;
290 }
291
292 switch (chan->mode) {
293 case L2CAP_MODE_BASIC:
294 case L2CAP_MODE_LE_FLOWCTL:
295 break;
296 case L2CAP_MODE_EXT_FLOWCTL:
297 if (!enable_ecred) {
298 err = -EOPNOTSUPP;
299 goto done;
300 }
301 break;
302 case L2CAP_MODE_ERTM:
303 case L2CAP_MODE_STREAMING:
304 if (!disable_ertm)
305 break;
306 fallthrough;
307 default:
308 err = -EOPNOTSUPP;
309 goto done;
310 }
311
312 sk->sk_max_ack_backlog = backlog;
313 sk->sk_ack_backlog = 0;
314
315 /* Listening channels need to use nested locking in order not to
316 * cause lockdep warnings when the created child channels end up
317 * being locked in the same thread as the parent channel.
318 */
319 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
320
321 chan->state = BT_LISTEN;
322 sk->sk_state = BT_LISTEN;
323
324 done:
325 release_sock(sk);
326 return err;
327 }
328
l2cap_sock_accept(struct socket * sock,struct socket * newsock,struct proto_accept_arg * arg)329 static int l2cap_sock_accept(struct socket *sock, struct socket *newsock,
330 struct proto_accept_arg *arg)
331 {
332 DEFINE_WAIT_FUNC(wait, woken_wake_function);
333 struct sock *sk = sock->sk, *nsk;
334 long timeo;
335 int err = 0;
336
337 lock_sock_nested(sk, L2CAP_NESTING_PARENT);
338
339 timeo = sock_rcvtimeo(sk, arg->flags & O_NONBLOCK);
340
341 BT_DBG("sk %p timeo %ld", sk, timeo);
342
343 /* Wait for an incoming connection. (wake-one). */
344 add_wait_queue_exclusive(sk_sleep(sk), &wait);
345 while (1) {
346 if (sk->sk_state != BT_LISTEN) {
347 err = -EBADFD;
348 break;
349 }
350
351 nsk = bt_accept_dequeue(sk, newsock);
352 if (nsk)
353 break;
354
355 if (!timeo) {
356 err = -EAGAIN;
357 break;
358 }
359
360 if (signal_pending(current)) {
361 err = sock_intr_errno(timeo);
362 break;
363 }
364
365 release_sock(sk);
366
367 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
368
369 lock_sock_nested(sk, L2CAP_NESTING_PARENT);
370 }
371 remove_wait_queue(sk_sleep(sk), &wait);
372
373 if (err)
374 goto done;
375
376 newsock->state = SS_CONNECTED;
377
378 BT_DBG("new socket %p", nsk);
379
380 done:
381 release_sock(sk);
382 return err;
383 }
384
l2cap_sock_getname(struct socket * sock,struct sockaddr * addr,int peer)385 static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr,
386 int peer)
387 {
388 struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr;
389 struct sock *sk = sock->sk;
390 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
391
392 BT_DBG("sock %p, sk %p", sock, sk);
393
394 if (peer && sk->sk_state != BT_CONNECTED &&
395 sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2 &&
396 sk->sk_state != BT_CONFIG)
397 return -ENOTCONN;
398
399 memset(la, 0, sizeof(struct sockaddr_l2));
400 addr->sa_family = AF_BLUETOOTH;
401
402 la->l2_psm = chan->psm;
403
404 if (peer) {
405 bacpy(&la->l2_bdaddr, &chan->dst);
406 la->l2_cid = cpu_to_le16(chan->dcid);
407 la->l2_bdaddr_type = chan->dst_type;
408 } else {
409 bacpy(&la->l2_bdaddr, &chan->src);
410 la->l2_cid = cpu_to_le16(chan->scid);
411 la->l2_bdaddr_type = chan->src_type;
412 }
413
414 return sizeof(struct sockaddr_l2);
415 }
416
l2cap_get_mode(struct l2cap_chan * chan)417 static int l2cap_get_mode(struct l2cap_chan *chan)
418 {
419 switch (chan->mode) {
420 case L2CAP_MODE_BASIC:
421 return BT_MODE_BASIC;
422 case L2CAP_MODE_ERTM:
423 return BT_MODE_ERTM;
424 case L2CAP_MODE_STREAMING:
425 return BT_MODE_STREAMING;
426 case L2CAP_MODE_LE_FLOWCTL:
427 return BT_MODE_LE_FLOWCTL;
428 case L2CAP_MODE_EXT_FLOWCTL:
429 return BT_MODE_EXT_FLOWCTL;
430 }
431
432 return -EINVAL;
433 }
434
l2cap_sock_getsockopt_old(struct socket * sock,int optname,char __user * optval,int __user * optlen)435 static int l2cap_sock_getsockopt_old(struct socket *sock, int optname,
436 char __user *optval, int __user *optlen)
437 {
438 struct sock *sk = sock->sk;
439 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
440 struct l2cap_options opts;
441 struct l2cap_conninfo cinfo;
442 int err = 0;
443 size_t len;
444 u32 opt;
445
446 BT_DBG("sk %p", sk);
447
448 if (get_user(len, optlen))
449 return -EFAULT;
450
451 lock_sock(sk);
452
453 switch (optname) {
454 case L2CAP_OPTIONS:
455 /* LE sockets should use BT_SNDMTU/BT_RCVMTU, but since
456 * legacy ATT code depends on getsockopt for
457 * L2CAP_OPTIONS we need to let this pass.
458 */
459 if (bdaddr_type_is_le(chan->src_type) &&
460 chan->scid != L2CAP_CID_ATT) {
461 err = -EINVAL;
462 break;
463 }
464
465 /* Only BR/EDR modes are supported here */
466 switch (chan->mode) {
467 case L2CAP_MODE_BASIC:
468 case L2CAP_MODE_ERTM:
469 case L2CAP_MODE_STREAMING:
470 break;
471 default:
472 err = -EINVAL;
473 break;
474 }
475
476 if (err < 0)
477 break;
478
479 memset(&opts, 0, sizeof(opts));
480 opts.imtu = chan->imtu;
481 opts.omtu = chan->omtu;
482 opts.flush_to = chan->flush_to;
483 opts.mode = chan->mode;
484 opts.fcs = chan->fcs;
485 opts.max_tx = chan->max_tx;
486 opts.txwin_size = chan->tx_win;
487
488 BT_DBG("mode 0x%2.2x", chan->mode);
489
490 len = min(len, sizeof(opts));
491 if (copy_to_user(optval, (char *) &opts, len))
492 err = -EFAULT;
493
494 break;
495
496 case L2CAP_LM:
497 switch (chan->sec_level) {
498 case BT_SECURITY_LOW:
499 opt = L2CAP_LM_AUTH;
500 break;
501 case BT_SECURITY_MEDIUM:
502 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT;
503 break;
504 case BT_SECURITY_HIGH:
505 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT |
506 L2CAP_LM_SECURE;
507 break;
508 case BT_SECURITY_FIPS:
509 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT |
510 L2CAP_LM_SECURE | L2CAP_LM_FIPS;
511 break;
512 default:
513 opt = 0;
514 break;
515 }
516
517 if (test_bit(FLAG_ROLE_SWITCH, &chan->flags))
518 opt |= L2CAP_LM_MASTER;
519
520 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
521 opt |= L2CAP_LM_RELIABLE;
522
523 if (put_user(opt, (u32 __user *) optval))
524 err = -EFAULT;
525
526 break;
527
528 case L2CAP_CONNINFO:
529 if (sk->sk_state != BT_CONNECTED &&
530 !(sk->sk_state == BT_CONNECT2 &&
531 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags))) {
532 err = -ENOTCONN;
533 break;
534 }
535
536 memset(&cinfo, 0, sizeof(cinfo));
537 cinfo.hci_handle = chan->conn->hcon->handle;
538 memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3);
539
540 len = min(len, sizeof(cinfo));
541 if (copy_to_user(optval, (char *) &cinfo, len))
542 err = -EFAULT;
543
544 break;
545
546 default:
547 err = -ENOPROTOOPT;
548 break;
549 }
550
551 release_sock(sk);
552 return err;
553 }
554
l2cap_sock_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)555 static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname,
556 char __user *optval, int __user *optlen)
557 {
558 struct sock *sk = sock->sk;
559 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
560 struct bt_security sec;
561 struct bt_power pwr;
562 u32 phys;
563 int len, mode, err = 0;
564
565 BT_DBG("sk %p", sk);
566
567 if (level == SOL_L2CAP)
568 return l2cap_sock_getsockopt_old(sock, optname, optval, optlen);
569
570 if (level != SOL_BLUETOOTH)
571 return -ENOPROTOOPT;
572
573 if (get_user(len, optlen))
574 return -EFAULT;
575
576 lock_sock(sk);
577
578 switch (optname) {
579 case BT_SECURITY:
580 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
581 chan->chan_type != L2CAP_CHAN_FIXED &&
582 chan->chan_type != L2CAP_CHAN_RAW) {
583 err = -EINVAL;
584 break;
585 }
586
587 memset(&sec, 0, sizeof(sec));
588 if (chan->conn) {
589 sec.level = chan->conn->hcon->sec_level;
590
591 if (sk->sk_state == BT_CONNECTED)
592 sec.key_size = chan->conn->hcon->enc_key_size;
593 } else {
594 sec.level = chan->sec_level;
595 }
596
597 len = min_t(unsigned int, len, sizeof(sec));
598 if (copy_to_user(optval, (char *) &sec, len))
599 err = -EFAULT;
600
601 break;
602
603 case BT_DEFER_SETUP:
604 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
605 err = -EINVAL;
606 break;
607 }
608
609 if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
610 (u32 __user *) optval))
611 err = -EFAULT;
612
613 break;
614
615 case BT_FLUSHABLE:
616 if (put_user(test_bit(FLAG_FLUSHABLE, &chan->flags),
617 (u32 __user *) optval))
618 err = -EFAULT;
619
620 break;
621
622 case BT_POWER:
623 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM
624 && sk->sk_type != SOCK_RAW) {
625 err = -EINVAL;
626 break;
627 }
628
629 pwr.force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
630
631 len = min_t(unsigned int, len, sizeof(pwr));
632 if (copy_to_user(optval, (char *) &pwr, len))
633 err = -EFAULT;
634
635 break;
636
637 case BT_CHANNEL_POLICY:
638 if (put_user(chan->chan_policy, (u32 __user *) optval))
639 err = -EFAULT;
640 break;
641
642 case BT_SNDMTU:
643 if (!bdaddr_type_is_le(chan->src_type)) {
644 err = -EINVAL;
645 break;
646 }
647
648 if (sk->sk_state != BT_CONNECTED) {
649 err = -ENOTCONN;
650 break;
651 }
652
653 if (put_user(chan->omtu, (u16 __user *) optval))
654 err = -EFAULT;
655 break;
656
657 case BT_RCVMTU:
658 if (!bdaddr_type_is_le(chan->src_type)) {
659 err = -EINVAL;
660 break;
661 }
662
663 if (put_user(chan->imtu, (u16 __user *) optval))
664 err = -EFAULT;
665 break;
666
667 case BT_PHY:
668 if (sk->sk_state != BT_CONNECTED) {
669 err = -ENOTCONN;
670 break;
671 }
672
673 phys = hci_conn_get_phy(chan->conn->hcon);
674
675 if (put_user(phys, (u32 __user *) optval))
676 err = -EFAULT;
677 break;
678
679 case BT_MODE:
680 if (!enable_ecred) {
681 err = -ENOPROTOOPT;
682 break;
683 }
684
685 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
686 err = -EINVAL;
687 break;
688 }
689
690 mode = l2cap_get_mode(chan);
691 if (mode < 0) {
692 err = mode;
693 break;
694 }
695
696 if (put_user(mode, (u8 __user *) optval))
697 err = -EFAULT;
698 break;
699
700 default:
701 err = -ENOPROTOOPT;
702 break;
703 }
704
705 release_sock(sk);
706 return err;
707 }
708
l2cap_valid_mtu(struct l2cap_chan * chan,u16 mtu)709 static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu)
710 {
711 switch (chan->scid) {
712 case L2CAP_CID_ATT:
713 if (mtu && mtu < L2CAP_LE_MIN_MTU)
714 return false;
715 break;
716
717 default:
718 if (mtu && mtu < L2CAP_DEFAULT_MIN_MTU)
719 return false;
720 }
721
722 return true;
723 }
724
l2cap_sock_setsockopt_old(struct socket * sock,int optname,sockptr_t optval,unsigned int optlen)725 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname,
726 sockptr_t optval, unsigned int optlen)
727 {
728 struct sock *sk = sock->sk;
729 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
730 struct l2cap_options opts;
731 int err = 0;
732 u32 opt;
733
734 BT_DBG("sk %p", sk);
735
736 lock_sock(sk);
737
738 switch (optname) {
739 case L2CAP_OPTIONS:
740 if (bdaddr_type_is_le(chan->src_type)) {
741 err = -EINVAL;
742 break;
743 }
744
745 if (sk->sk_state == BT_CONNECTED) {
746 err = -EINVAL;
747 break;
748 }
749
750 opts.imtu = chan->imtu;
751 opts.omtu = chan->omtu;
752 opts.flush_to = chan->flush_to;
753 opts.mode = chan->mode;
754 opts.fcs = chan->fcs;
755 opts.max_tx = chan->max_tx;
756 opts.txwin_size = chan->tx_win;
757
758 err = copy_safe_from_sockptr(&opts, sizeof(opts), optval,
759 optlen);
760 if (err)
761 break;
762
763 if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) {
764 err = -EINVAL;
765 break;
766 }
767
768 if (!l2cap_valid_mtu(chan, opts.imtu)) {
769 err = -EINVAL;
770 break;
771 }
772
773 /* Only BR/EDR modes are supported here */
774 switch (opts.mode) {
775 case L2CAP_MODE_BASIC:
776 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state);
777 break;
778 case L2CAP_MODE_ERTM:
779 case L2CAP_MODE_STREAMING:
780 if (!disable_ertm)
781 break;
782 fallthrough;
783 default:
784 err = -EINVAL;
785 break;
786 }
787
788 if (err < 0)
789 break;
790
791 chan->mode = opts.mode;
792
793 BT_DBG("mode 0x%2.2x", chan->mode);
794
795 chan->imtu = opts.imtu;
796 chan->omtu = opts.omtu;
797 chan->fcs = opts.fcs;
798 chan->max_tx = opts.max_tx;
799 chan->tx_win = opts.txwin_size;
800 chan->flush_to = opts.flush_to;
801 break;
802
803 case L2CAP_LM:
804 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
805 if (err)
806 break;
807
808 if (opt & L2CAP_LM_FIPS) {
809 err = -EINVAL;
810 break;
811 }
812
813 if (opt & L2CAP_LM_AUTH)
814 chan->sec_level = BT_SECURITY_LOW;
815 if (opt & L2CAP_LM_ENCRYPT)
816 chan->sec_level = BT_SECURITY_MEDIUM;
817 if (opt & L2CAP_LM_SECURE)
818 chan->sec_level = BT_SECURITY_HIGH;
819
820 if (opt & L2CAP_LM_MASTER)
821 set_bit(FLAG_ROLE_SWITCH, &chan->flags);
822 else
823 clear_bit(FLAG_ROLE_SWITCH, &chan->flags);
824
825 if (opt & L2CAP_LM_RELIABLE)
826 set_bit(FLAG_FORCE_RELIABLE, &chan->flags);
827 else
828 clear_bit(FLAG_FORCE_RELIABLE, &chan->flags);
829 break;
830
831 default:
832 err = -ENOPROTOOPT;
833 break;
834 }
835
836 release_sock(sk);
837 return err;
838 }
839
l2cap_set_mode(struct l2cap_chan * chan,u8 mode)840 static int l2cap_set_mode(struct l2cap_chan *chan, u8 mode)
841 {
842 switch (mode) {
843 case BT_MODE_BASIC:
844 if (bdaddr_type_is_le(chan->src_type))
845 return -EINVAL;
846 mode = L2CAP_MODE_BASIC;
847 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state);
848 break;
849 case BT_MODE_ERTM:
850 if (!disable_ertm || bdaddr_type_is_le(chan->src_type))
851 return -EINVAL;
852 mode = L2CAP_MODE_ERTM;
853 break;
854 case BT_MODE_STREAMING:
855 if (!disable_ertm || bdaddr_type_is_le(chan->src_type))
856 return -EINVAL;
857 mode = L2CAP_MODE_STREAMING;
858 break;
859 case BT_MODE_LE_FLOWCTL:
860 if (!bdaddr_type_is_le(chan->src_type))
861 return -EINVAL;
862 mode = L2CAP_MODE_LE_FLOWCTL;
863 break;
864 case BT_MODE_EXT_FLOWCTL:
865 /* TODO: Add support for ECRED PDUs to BR/EDR */
866 if (!bdaddr_type_is_le(chan->src_type))
867 return -EINVAL;
868 mode = L2CAP_MODE_EXT_FLOWCTL;
869 break;
870 default:
871 return -EINVAL;
872 }
873
874 chan->mode = mode;
875
876 return 0;
877 }
878
l2cap_sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)879 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
880 sockptr_t optval, unsigned int optlen)
881 {
882 struct sock *sk = sock->sk;
883 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
884 struct bt_security sec;
885 struct bt_power pwr;
886 struct l2cap_conn *conn;
887 int err = 0;
888 u32 opt;
889 u16 mtu;
890 u8 mode;
891
892 BT_DBG("sk %p", sk);
893
894 if (level == SOL_L2CAP)
895 return l2cap_sock_setsockopt_old(sock, optname, optval, optlen);
896
897 if (level != SOL_BLUETOOTH)
898 return -ENOPROTOOPT;
899
900 lock_sock(sk);
901
902 switch (optname) {
903 case BT_SECURITY:
904 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
905 chan->chan_type != L2CAP_CHAN_FIXED &&
906 chan->chan_type != L2CAP_CHAN_RAW) {
907 err = -EINVAL;
908 break;
909 }
910
911 sec.level = BT_SECURITY_LOW;
912
913 err = copy_safe_from_sockptr(&sec, sizeof(sec), optval, optlen);
914 if (err)
915 break;
916
917 if (sec.level < BT_SECURITY_LOW ||
918 sec.level > BT_SECURITY_FIPS) {
919 err = -EINVAL;
920 break;
921 }
922
923 chan->sec_level = sec.level;
924
925 if (!chan->conn)
926 break;
927
928 conn = chan->conn;
929
930 /* change security for LE channels */
931 if (chan->scid == L2CAP_CID_ATT) {
932 if (smp_conn_security(conn->hcon, sec.level)) {
933 err = -EINVAL;
934 break;
935 }
936
937 set_bit(FLAG_PENDING_SECURITY, &chan->flags);
938 sk->sk_state = BT_CONFIG;
939 chan->state = BT_CONFIG;
940
941 /* or for ACL link */
942 } else if ((sk->sk_state == BT_CONNECT2 &&
943 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) ||
944 sk->sk_state == BT_CONNECTED) {
945 if (!l2cap_chan_check_security(chan, true))
946 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
947 else
948 sk->sk_state_change(sk);
949 } else {
950 err = -EINVAL;
951 }
952 break;
953
954 case BT_DEFER_SETUP:
955 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
956 err = -EINVAL;
957 break;
958 }
959
960 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
961 if (err)
962 break;
963
964 if (opt) {
965 set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
966 set_bit(FLAG_DEFER_SETUP, &chan->flags);
967 } else {
968 clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
969 clear_bit(FLAG_DEFER_SETUP, &chan->flags);
970 }
971 break;
972
973 case BT_FLUSHABLE:
974 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
975 if (err)
976 break;
977
978 if (opt > BT_FLUSHABLE_ON) {
979 err = -EINVAL;
980 break;
981 }
982
983 if (opt == BT_FLUSHABLE_OFF) {
984 conn = chan->conn;
985 /* proceed further only when we have l2cap_conn and
986 No Flush support in the LM */
987 if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) {
988 err = -EINVAL;
989 break;
990 }
991 }
992
993 if (opt)
994 set_bit(FLAG_FLUSHABLE, &chan->flags);
995 else
996 clear_bit(FLAG_FLUSHABLE, &chan->flags);
997 break;
998
999 case BT_POWER:
1000 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
1001 chan->chan_type != L2CAP_CHAN_RAW) {
1002 err = -EINVAL;
1003 break;
1004 }
1005
1006 pwr.force_active = BT_POWER_FORCE_ACTIVE_ON;
1007
1008 err = copy_safe_from_sockptr(&pwr, sizeof(pwr), optval, optlen);
1009 if (err)
1010 break;
1011
1012 if (pwr.force_active)
1013 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
1014 else
1015 clear_bit(FLAG_FORCE_ACTIVE, &chan->flags);
1016 break;
1017
1018 case BT_CHANNEL_POLICY:
1019 err = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
1020 if (err)
1021 break;
1022
1023 err = -EOPNOTSUPP;
1024 break;
1025
1026 case BT_SNDMTU:
1027 if (!bdaddr_type_is_le(chan->src_type)) {
1028 err = -EINVAL;
1029 break;
1030 }
1031
1032 /* Setting is not supported as it's the remote side that
1033 * decides this.
1034 */
1035 err = -EPERM;
1036 break;
1037
1038 case BT_RCVMTU:
1039 if (!bdaddr_type_is_le(chan->src_type)) {
1040 err = -EINVAL;
1041 break;
1042 }
1043
1044 if (chan->mode == L2CAP_MODE_LE_FLOWCTL &&
1045 sk->sk_state == BT_CONNECTED) {
1046 err = -EISCONN;
1047 break;
1048 }
1049
1050 err = copy_safe_from_sockptr(&mtu, sizeof(mtu), optval, optlen);
1051 if (err)
1052 break;
1053
1054 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL &&
1055 sk->sk_state == BT_CONNECTED)
1056 err = l2cap_chan_reconfigure(chan, mtu);
1057 else
1058 chan->imtu = mtu;
1059
1060 break;
1061
1062 case BT_MODE:
1063 if (!enable_ecred) {
1064 err = -ENOPROTOOPT;
1065 break;
1066 }
1067
1068 BT_DBG("sk->sk_state %u", sk->sk_state);
1069
1070 if (sk->sk_state != BT_BOUND) {
1071 err = -EINVAL;
1072 break;
1073 }
1074
1075 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1076 err = -EINVAL;
1077 break;
1078 }
1079
1080 err = copy_safe_from_sockptr(&mode, sizeof(mode), optval,
1081 optlen);
1082 if (err)
1083 break;
1084
1085 BT_DBG("mode %u", mode);
1086
1087 err = l2cap_set_mode(chan, mode);
1088 if (err)
1089 break;
1090
1091 BT_DBG("mode 0x%2.2x", chan->mode);
1092
1093 break;
1094
1095 default:
1096 err = -ENOPROTOOPT;
1097 break;
1098 }
1099
1100 release_sock(sk);
1101 return err;
1102 }
1103
l2cap_sock_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)1104 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg,
1105 size_t len)
1106 {
1107 struct sock *sk = sock->sk;
1108 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1109 int err;
1110
1111 BT_DBG("sock %p, sk %p", sock, sk);
1112
1113 err = sock_error(sk);
1114 if (err)
1115 return err;
1116
1117 if (msg->msg_flags & MSG_OOB)
1118 return -EOPNOTSUPP;
1119
1120 if (sk->sk_state != BT_CONNECTED)
1121 return -ENOTCONN;
1122
1123 lock_sock(sk);
1124 err = bt_sock_wait_ready(sk, msg->msg_flags);
1125 release_sock(sk);
1126 if (err)
1127 return err;
1128
1129 l2cap_chan_lock(chan);
1130 err = l2cap_chan_send(chan, msg, len);
1131 l2cap_chan_unlock(chan);
1132
1133 return err;
1134 }
1135
l2cap_publish_rx_avail(struct l2cap_chan * chan)1136 static void l2cap_publish_rx_avail(struct l2cap_chan *chan)
1137 {
1138 struct sock *sk = chan->data;
1139 ssize_t avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc);
1140 int expected_skbs, skb_overhead;
1141
1142 if (avail <= 0) {
1143 l2cap_chan_rx_avail(chan, 0);
1144 return;
1145 }
1146
1147 if (!chan->mps) {
1148 l2cap_chan_rx_avail(chan, -1);
1149 return;
1150 }
1151
1152 /* Correct available memory by estimated sk_buff overhead.
1153 * This is significant due to small transfer sizes. However, accept
1154 * at least one full packet if receive space is non-zero.
1155 */
1156 expected_skbs = DIV_ROUND_UP(avail, chan->mps);
1157 skb_overhead = expected_skbs * sizeof(struct sk_buff);
1158 if (skb_overhead < avail)
1159 l2cap_chan_rx_avail(chan, avail - skb_overhead);
1160 else
1161 l2cap_chan_rx_avail(chan, -1);
1162 }
1163
l2cap_sock_recvmsg(struct socket * sock,struct msghdr * msg,size_t len,int flags)1164 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1165 size_t len, int flags)
1166 {
1167 struct sock *sk = sock->sk;
1168 struct l2cap_pinfo *pi = l2cap_pi(sk);
1169 int err;
1170
1171 lock_sock(sk);
1172
1173 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP,
1174 &bt_sk(sk)->flags)) {
1175 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
1176 sk->sk_state = BT_CONNECTED;
1177 pi->chan->state = BT_CONNECTED;
1178 __l2cap_ecred_conn_rsp_defer(pi->chan);
1179 } else if (bdaddr_type_is_le(pi->chan->src_type)) {
1180 sk->sk_state = BT_CONNECTED;
1181 pi->chan->state = BT_CONNECTED;
1182 __l2cap_le_connect_rsp_defer(pi->chan);
1183 } else {
1184 sk->sk_state = BT_CONFIG;
1185 pi->chan->state = BT_CONFIG;
1186 __l2cap_connect_rsp_defer(pi->chan);
1187 }
1188
1189 err = 0;
1190 goto done;
1191 }
1192
1193 release_sock(sk);
1194
1195 if (sock->type == SOCK_STREAM)
1196 err = bt_sock_stream_recvmsg(sock, msg, len, flags);
1197 else
1198 err = bt_sock_recvmsg(sock, msg, len, flags);
1199
1200 if (pi->chan->mode != L2CAP_MODE_ERTM &&
1201 pi->chan->mode != L2CAP_MODE_LE_FLOWCTL &&
1202 pi->chan->mode != L2CAP_MODE_EXT_FLOWCTL)
1203 return err;
1204
1205 lock_sock(sk);
1206
1207 l2cap_publish_rx_avail(pi->chan);
1208
1209 /* Attempt to put pending rx data in the socket buffer */
1210 while (!list_empty(&pi->rx_busy)) {
1211 struct l2cap_rx_busy *rx_busy =
1212 list_first_entry(&pi->rx_busy,
1213 struct l2cap_rx_busy,
1214 list);
1215 if (__sock_queue_rcv_skb(sk, rx_busy->skb) < 0)
1216 goto done;
1217 list_del(&rx_busy->list);
1218 kfree(rx_busy);
1219 }
1220
1221 /* Restore data flow when half of the receive buffer is
1222 * available. This avoids resending large numbers of
1223 * frames.
1224 */
1225 if (test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state) &&
1226 atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1)
1227 l2cap_chan_busy(pi->chan, 0);
1228
1229 done:
1230 release_sock(sk);
1231 return err;
1232 }
1233
1234 /* Kill socket (only if zapped and orphan)
1235 * Must be called on unlocked socket, with l2cap channel lock.
1236 */
l2cap_sock_kill(struct sock * sk)1237 static void l2cap_sock_kill(struct sock *sk)
1238 {
1239 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
1240 return;
1241
1242 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state));
1243
1244 /* Sock is dead, so set chan data to NULL, avoid other task use invalid
1245 * sock pointer.
1246 */
1247 l2cap_pi(sk)->chan->data = NULL;
1248 /* Kill poor orphan */
1249
1250 l2cap_chan_put(l2cap_pi(sk)->chan);
1251 sock_set_flag(sk, SOCK_DEAD);
1252 sock_put(sk);
1253 }
1254
__l2cap_wait_ack(struct sock * sk,struct l2cap_chan * chan)1255 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan)
1256 {
1257 DECLARE_WAITQUEUE(wait, current);
1258 int err = 0;
1259 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD;
1260 /* Timeout to prevent infinite loop */
1261 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT;
1262
1263 add_wait_queue(sk_sleep(sk), &wait);
1264 set_current_state(TASK_INTERRUPTIBLE);
1265 do {
1266 BT_DBG("Waiting for %d ACKs, timeout %04d ms",
1267 chan->unacked_frames, time_after(jiffies, timeout) ? 0 :
1268 jiffies_to_msecs(timeout - jiffies));
1269
1270 if (!timeo)
1271 timeo = L2CAP_WAIT_ACK_POLL_PERIOD;
1272
1273 if (signal_pending(current)) {
1274 err = sock_intr_errno(timeo);
1275 break;
1276 }
1277
1278 release_sock(sk);
1279 timeo = schedule_timeout(timeo);
1280 lock_sock(sk);
1281 set_current_state(TASK_INTERRUPTIBLE);
1282
1283 err = sock_error(sk);
1284 if (err)
1285 break;
1286
1287 if (time_after(jiffies, timeout)) {
1288 err = -ENOLINK;
1289 break;
1290 }
1291
1292 } while (chan->unacked_frames > 0 &&
1293 chan->state == BT_CONNECTED);
1294
1295 set_current_state(TASK_RUNNING);
1296 remove_wait_queue(sk_sleep(sk), &wait);
1297 return err;
1298 }
1299
l2cap_sock_shutdown(struct socket * sock,int how)1300 static int l2cap_sock_shutdown(struct socket *sock, int how)
1301 {
1302 struct sock *sk = sock->sk;
1303 struct l2cap_chan *chan;
1304 struct l2cap_conn *conn;
1305 int err = 0;
1306
1307 BT_DBG("sock %p, sk %p, how %d", sock, sk, how);
1308
1309 /* 'how' parameter is mapped to sk_shutdown as follows:
1310 * SHUT_RD (0) --> RCV_SHUTDOWN (1)
1311 * SHUT_WR (1) --> SEND_SHUTDOWN (2)
1312 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3)
1313 */
1314 how++;
1315
1316 if (!sk)
1317 return 0;
1318
1319 lock_sock(sk);
1320
1321 if ((sk->sk_shutdown & how) == how)
1322 goto shutdown_already;
1323
1324 BT_DBG("Handling sock shutdown");
1325
1326 /* prevent sk structure from being freed whilst unlocked */
1327 sock_hold(sk);
1328
1329 /* prevent chan structure from being freed whilst unlocked */
1330 chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan);
1331 if (!chan)
1332 goto shutdown_already;
1333
1334 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
1335
1336 if (chan->mode == L2CAP_MODE_ERTM &&
1337 chan->unacked_frames > 0 &&
1338 chan->state == BT_CONNECTED) {
1339 err = __l2cap_wait_ack(sk, chan);
1340
1341 /* After waiting for ACKs, check whether shutdown
1342 * has already been actioned to close the L2CAP
1343 * link such as by l2cap_disconnection_req().
1344 */
1345 if ((sk->sk_shutdown & how) == how)
1346 goto shutdown_matched;
1347 }
1348
1349 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN
1350 * is already set
1351 */
1352 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1353 sk->sk_shutdown |= RCV_SHUTDOWN;
1354 if ((sk->sk_shutdown & how) == how)
1355 goto shutdown_matched;
1356 }
1357
1358 sk->sk_shutdown |= SEND_SHUTDOWN;
1359 release_sock(sk);
1360
1361 l2cap_chan_lock(chan);
1362 /* prevent conn structure from being freed */
1363 conn = l2cap_conn_hold_unless_zero(chan->conn);
1364 l2cap_chan_unlock(chan);
1365
1366 if (conn)
1367 /* mutex lock must be taken before l2cap_chan_lock() */
1368 mutex_lock(&conn->lock);
1369
1370 l2cap_chan_lock(chan);
1371 l2cap_chan_close(chan, 0);
1372 l2cap_chan_unlock(chan);
1373
1374 if (conn) {
1375 mutex_unlock(&conn->lock);
1376 l2cap_conn_put(conn);
1377 }
1378
1379 lock_sock(sk);
1380
1381 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
1382 !(current->flags & PF_EXITING))
1383 err = bt_sock_wait_state(sk, BT_CLOSED,
1384 sk->sk_lingertime);
1385
1386 shutdown_matched:
1387 l2cap_chan_put(chan);
1388 sock_put(sk);
1389
1390 shutdown_already:
1391 if (!err && sk->sk_err)
1392 err = -sk->sk_err;
1393
1394 release_sock(sk);
1395
1396 BT_DBG("Sock shutdown complete err: %d", err);
1397
1398 return err;
1399 }
1400
l2cap_sock_release(struct socket * sock)1401 static int l2cap_sock_release(struct socket *sock)
1402 {
1403 struct sock *sk = sock->sk;
1404 int err;
1405 struct l2cap_chan *chan;
1406
1407 BT_DBG("sock %p, sk %p", sock, sk);
1408
1409 if (!sk)
1410 return 0;
1411
1412 lock_sock_nested(sk, L2CAP_NESTING_PARENT);
1413 l2cap_sock_cleanup_listen(sk);
1414 release_sock(sk);
1415
1416 bt_sock_unlink(&l2cap_sk_list, sk);
1417
1418 err = l2cap_sock_shutdown(sock, SHUT_RDWR);
1419 chan = l2cap_pi(sk)->chan;
1420
1421 l2cap_chan_hold(chan);
1422 l2cap_chan_lock(chan);
1423
1424 sock_orphan(sk);
1425 l2cap_sock_kill(sk);
1426
1427 l2cap_chan_unlock(chan);
1428 l2cap_chan_put(chan);
1429
1430 return err;
1431 }
1432
l2cap_sock_cleanup_listen(struct sock * parent)1433 static void l2cap_sock_cleanup_listen(struct sock *parent)
1434 {
1435 struct sock *sk;
1436
1437 BT_DBG("parent %p state %s", parent,
1438 state_to_string(parent->sk_state));
1439
1440 /* Close not yet accepted channels */
1441 while ((sk = bt_accept_dequeue(parent, NULL))) {
1442 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1443
1444 BT_DBG("child chan %p state %s", chan,
1445 state_to_string(chan->state));
1446
1447 l2cap_chan_hold(chan);
1448 l2cap_chan_lock(chan);
1449
1450 __clear_chan_timer(chan);
1451 l2cap_chan_close(chan, ECONNRESET);
1452 l2cap_sock_kill(sk);
1453
1454 l2cap_chan_unlock(chan);
1455 l2cap_chan_put(chan);
1456 }
1457 }
1458
l2cap_sock_new_connection_cb(struct l2cap_chan * chan)1459 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
1460 {
1461 struct sock *sk, *parent = chan->data;
1462
1463 lock_sock(parent);
1464
1465 /* Check for backlog size */
1466 if (sk_acceptq_is_full(parent)) {
1467 BT_DBG("backlog full %d", parent->sk_ack_backlog);
1468 release_sock(parent);
1469 return NULL;
1470 }
1471
1472 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP,
1473 GFP_ATOMIC, 0);
1474 if (!sk) {
1475 release_sock(parent);
1476 return NULL;
1477 }
1478
1479 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP);
1480
1481 l2cap_sock_init(sk, parent);
1482
1483 bt_accept_enqueue(parent, sk, false);
1484
1485 release_sock(parent);
1486
1487 return l2cap_pi(sk)->chan;
1488 }
1489
l2cap_sock_recv_cb(struct l2cap_chan * chan,struct sk_buff * skb)1490 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
1491 {
1492 struct sock *sk;
1493 struct l2cap_pinfo *pi;
1494 int err;
1495
1496 sk = chan->data;
1497 if (!sk)
1498 return -ENXIO;
1499
1500 pi = l2cap_pi(sk);
1501 lock_sock(sk);
1502 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) {
1503 err = -ENOMEM;
1504 goto done;
1505 }
1506
1507 if (chan->mode != L2CAP_MODE_ERTM &&
1508 chan->mode != L2CAP_MODE_STREAMING &&
1509 chan->mode != L2CAP_MODE_LE_FLOWCTL &&
1510 chan->mode != L2CAP_MODE_EXT_FLOWCTL) {
1511 /* Even if no filter is attached, we could potentially
1512 * get errors from security modules, etc.
1513 */
1514 err = sk_filter(sk, skb);
1515 if (err)
1516 goto done;
1517 }
1518
1519 err = __sock_queue_rcv_skb(sk, skb);
1520
1521 l2cap_publish_rx_avail(chan);
1522
1523 /* For ERTM and LE, handle a skb that doesn't fit into the recv
1524 * buffer. This is important to do because the data frames
1525 * have already been acked, so the skb cannot be discarded.
1526 *
1527 * Notify the l2cap core that the buffer is full, so the
1528 * LOCAL_BUSY state is entered and no more frames are
1529 * acked and reassembled until there is buffer space
1530 * available.
1531 */
1532 if (err < 0 &&
1533 (chan->mode == L2CAP_MODE_ERTM ||
1534 chan->mode == L2CAP_MODE_LE_FLOWCTL ||
1535 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) {
1536 struct l2cap_rx_busy *rx_busy =
1537 kmalloc(sizeof(*rx_busy), GFP_KERNEL);
1538 if (!rx_busy) {
1539 err = -ENOMEM;
1540 goto done;
1541 }
1542 rx_busy->skb = skb;
1543 list_add_tail(&rx_busy->list, &pi->rx_busy);
1544 l2cap_chan_busy(chan, 1);
1545 err = 0;
1546 }
1547
1548 done:
1549 release_sock(sk);
1550
1551 return err;
1552 }
1553
l2cap_sock_close_cb(struct l2cap_chan * chan)1554 static void l2cap_sock_close_cb(struct l2cap_chan *chan)
1555 {
1556 struct sock *sk = chan->data;
1557
1558 if (!sk)
1559 return;
1560
1561 l2cap_sock_kill(sk);
1562 }
1563
l2cap_sock_teardown_cb(struct l2cap_chan * chan,int err)1564 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err)
1565 {
1566 struct sock *sk = chan->data;
1567 struct sock *parent;
1568
1569 if (!sk)
1570 return;
1571
1572 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
1573
1574 /* This callback can be called both for server (BT_LISTEN)
1575 * sockets as well as "normal" ones. To avoid lockdep warnings
1576 * with child socket locking (through l2cap_sock_cleanup_listen)
1577 * we need separation into separate nesting levels. The simplest
1578 * way to accomplish this is to inherit the nesting level used
1579 * for the channel.
1580 */
1581 lock_sock_nested(sk, atomic_read(&chan->nesting));
1582
1583 parent = bt_sk(sk)->parent;
1584
1585 switch (chan->state) {
1586 case BT_OPEN:
1587 case BT_BOUND:
1588 case BT_CLOSED:
1589 break;
1590 case BT_LISTEN:
1591 l2cap_sock_cleanup_listen(sk);
1592 sk->sk_state = BT_CLOSED;
1593 chan->state = BT_CLOSED;
1594
1595 break;
1596 default:
1597 sk->sk_state = BT_CLOSED;
1598 chan->state = BT_CLOSED;
1599
1600 sk->sk_err = err;
1601
1602 if (parent) {
1603 bt_accept_unlink(sk);
1604 parent->sk_data_ready(parent);
1605 } else {
1606 sk->sk_state_change(sk);
1607 }
1608
1609 break;
1610 }
1611 release_sock(sk);
1612
1613 /* Only zap after cleanup to avoid use after free race */
1614 sock_set_flag(sk, SOCK_ZAPPED);
1615
1616 }
1617
l2cap_sock_state_change_cb(struct l2cap_chan * chan,int state,int err)1618 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state,
1619 int err)
1620 {
1621 struct sock *sk = chan->data;
1622
1623 sk->sk_state = state;
1624
1625 if (err)
1626 sk->sk_err = err;
1627 }
1628
l2cap_sock_alloc_skb_cb(struct l2cap_chan * chan,unsigned long hdr_len,unsigned long len,int nb)1629 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan,
1630 unsigned long hdr_len,
1631 unsigned long len, int nb)
1632 {
1633 struct sock *sk = chan->data;
1634 struct sk_buff *skb;
1635 int err;
1636
1637 l2cap_chan_unlock(chan);
1638 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err);
1639 l2cap_chan_lock(chan);
1640
1641 if (!skb)
1642 return ERR_PTR(err);
1643
1644 /* Channel lock is released before requesting new skb and then
1645 * reacquired thus we need to recheck channel state.
1646 */
1647 if (chan->state != BT_CONNECTED) {
1648 kfree_skb(skb);
1649 return ERR_PTR(-ENOTCONN);
1650 }
1651
1652 skb->priority = READ_ONCE(sk->sk_priority);
1653
1654 bt_cb(skb)->l2cap.chan = chan;
1655
1656 return skb;
1657 }
1658
l2cap_sock_ready_cb(struct l2cap_chan * chan)1659 static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
1660 {
1661 struct sock *sk = chan->data;
1662 struct sock *parent;
1663
1664 lock_sock(sk);
1665
1666 parent = bt_sk(sk)->parent;
1667
1668 BT_DBG("sk %p, parent %p", sk, parent);
1669
1670 sk->sk_state = BT_CONNECTED;
1671 sk->sk_state_change(sk);
1672
1673 if (parent)
1674 parent->sk_data_ready(parent);
1675
1676 release_sock(sk);
1677 }
1678
l2cap_sock_defer_cb(struct l2cap_chan * chan)1679 static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
1680 {
1681 struct sock *parent, *sk = chan->data;
1682
1683 lock_sock(sk);
1684
1685 parent = bt_sk(sk)->parent;
1686 if (parent)
1687 parent->sk_data_ready(parent);
1688
1689 release_sock(sk);
1690 }
1691
l2cap_sock_resume_cb(struct l2cap_chan * chan)1692 static void l2cap_sock_resume_cb(struct l2cap_chan *chan)
1693 {
1694 struct sock *sk = chan->data;
1695
1696 if (!sk)
1697 return;
1698
1699 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) {
1700 sk->sk_state = BT_CONNECTED;
1701 chan->state = BT_CONNECTED;
1702 }
1703
1704 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1705 sk->sk_state_change(sk);
1706 }
1707
l2cap_sock_set_shutdown_cb(struct l2cap_chan * chan)1708 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan)
1709 {
1710 struct sock *sk = chan->data;
1711
1712 lock_sock(sk);
1713 sk->sk_shutdown = SHUTDOWN_MASK;
1714 release_sock(sk);
1715 }
1716
l2cap_sock_get_sndtimeo_cb(struct l2cap_chan * chan)1717 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
1718 {
1719 struct sock *sk = chan->data;
1720
1721 return sk->sk_sndtimeo;
1722 }
1723
l2cap_sock_get_peer_pid_cb(struct l2cap_chan * chan)1724 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan)
1725 {
1726 struct sock *sk = chan->data;
1727
1728 return sk->sk_peer_pid;
1729 }
1730
l2cap_sock_suspend_cb(struct l2cap_chan * chan)1731 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
1732 {
1733 struct sock *sk = chan->data;
1734
1735 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1736 sk->sk_state_change(sk);
1737 }
1738
l2cap_sock_filter(struct l2cap_chan * chan,struct sk_buff * skb)1739 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb)
1740 {
1741 struct sock *sk = chan->data;
1742
1743 switch (chan->mode) {
1744 case L2CAP_MODE_ERTM:
1745 case L2CAP_MODE_STREAMING:
1746 return sk_filter(sk, skb);
1747 }
1748
1749 return 0;
1750 }
1751
1752 static const struct l2cap_ops l2cap_chan_ops = {
1753 .name = "L2CAP Socket Interface",
1754 .new_connection = l2cap_sock_new_connection_cb,
1755 .recv = l2cap_sock_recv_cb,
1756 .close = l2cap_sock_close_cb,
1757 .teardown = l2cap_sock_teardown_cb,
1758 .state_change = l2cap_sock_state_change_cb,
1759 .ready = l2cap_sock_ready_cb,
1760 .defer = l2cap_sock_defer_cb,
1761 .resume = l2cap_sock_resume_cb,
1762 .suspend = l2cap_sock_suspend_cb,
1763 .set_shutdown = l2cap_sock_set_shutdown_cb,
1764 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
1765 .get_peer_pid = l2cap_sock_get_peer_pid_cb,
1766 .alloc_skb = l2cap_sock_alloc_skb_cb,
1767 .filter = l2cap_sock_filter,
1768 };
1769
l2cap_sock_destruct(struct sock * sk)1770 static void l2cap_sock_destruct(struct sock *sk)
1771 {
1772 struct l2cap_rx_busy *rx_busy, *next;
1773
1774 BT_DBG("sk %p", sk);
1775
1776 if (l2cap_pi(sk)->chan) {
1777 l2cap_pi(sk)->chan->data = NULL;
1778 l2cap_chan_put(l2cap_pi(sk)->chan);
1779 }
1780
1781 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) {
1782 kfree_skb(rx_busy->skb);
1783 list_del(&rx_busy->list);
1784 kfree(rx_busy);
1785 }
1786
1787 skb_queue_purge(&sk->sk_receive_queue);
1788 skb_queue_purge(&sk->sk_write_queue);
1789 }
1790
l2cap_skb_msg_name(struct sk_buff * skb,void * msg_name,int * msg_namelen)1791 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name,
1792 int *msg_namelen)
1793 {
1794 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name);
1795
1796 memset(la, 0, sizeof(struct sockaddr_l2));
1797 la->l2_family = AF_BLUETOOTH;
1798 la->l2_psm = bt_cb(skb)->l2cap.psm;
1799 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr);
1800
1801 *msg_namelen = sizeof(struct sockaddr_l2);
1802 }
1803
l2cap_sock_init(struct sock * sk,struct sock * parent)1804 static void l2cap_sock_init(struct sock *sk, struct sock *parent)
1805 {
1806 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1807
1808 BT_DBG("sk %p", sk);
1809
1810 if (parent) {
1811 struct l2cap_chan *pchan = l2cap_pi(parent)->chan;
1812
1813 sk->sk_type = parent->sk_type;
1814 bt_sk(sk)->flags = bt_sk(parent)->flags;
1815
1816 chan->chan_type = pchan->chan_type;
1817 chan->imtu = pchan->imtu;
1818 chan->omtu = pchan->omtu;
1819 chan->conf_state = pchan->conf_state;
1820 chan->mode = pchan->mode;
1821 chan->fcs = pchan->fcs;
1822 chan->max_tx = pchan->max_tx;
1823 chan->tx_win = pchan->tx_win;
1824 chan->tx_win_max = pchan->tx_win_max;
1825 chan->sec_level = pchan->sec_level;
1826 chan->flags = pchan->flags;
1827 chan->tx_credits = pchan->tx_credits;
1828 chan->rx_credits = pchan->rx_credits;
1829
1830 if (chan->chan_type == L2CAP_CHAN_FIXED) {
1831 chan->scid = pchan->scid;
1832 chan->dcid = pchan->scid;
1833 }
1834
1835 security_sk_clone(parent, sk);
1836 } else {
1837 switch (sk->sk_type) {
1838 case SOCK_RAW:
1839 chan->chan_type = L2CAP_CHAN_RAW;
1840 break;
1841 case SOCK_DGRAM:
1842 chan->chan_type = L2CAP_CHAN_CONN_LESS;
1843 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name;
1844 break;
1845 case SOCK_SEQPACKET:
1846 case SOCK_STREAM:
1847 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
1848 break;
1849 }
1850
1851 chan->imtu = L2CAP_DEFAULT_MTU;
1852 chan->omtu = 0;
1853 if (!disable_ertm && sk->sk_type == SOCK_STREAM) {
1854 chan->mode = L2CAP_MODE_ERTM;
1855 set_bit(CONF_STATE2_DEVICE, &chan->conf_state);
1856 } else {
1857 chan->mode = L2CAP_MODE_BASIC;
1858 }
1859
1860 l2cap_chan_set_defaults(chan);
1861 }
1862
1863 /* Default config options */
1864 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
1865
1866 chan->data = sk;
1867 chan->ops = &l2cap_chan_ops;
1868
1869 l2cap_publish_rx_avail(chan);
1870 }
1871
1872 static struct proto l2cap_proto = {
1873 .name = "L2CAP",
1874 .owner = THIS_MODULE,
1875 .obj_size = sizeof(struct l2cap_pinfo)
1876 };
1877
l2cap_sock_alloc(struct net * net,struct socket * sock,int proto,gfp_t prio,int kern)1878 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
1879 int proto, gfp_t prio, int kern)
1880 {
1881 struct sock *sk;
1882 struct l2cap_chan *chan;
1883
1884 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern);
1885 if (!sk)
1886 return NULL;
1887
1888 sk->sk_destruct = l2cap_sock_destruct;
1889 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT;
1890
1891 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy);
1892
1893 chan = l2cap_chan_create();
1894 if (!chan) {
1895 sk_free(sk);
1896 if (sock)
1897 sock->sk = NULL;
1898 return NULL;
1899 }
1900
1901 l2cap_chan_hold(chan);
1902
1903 l2cap_pi(sk)->chan = chan;
1904
1905 return sk;
1906 }
1907
l2cap_sock_create(struct net * net,struct socket * sock,int protocol,int kern)1908 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol,
1909 int kern)
1910 {
1911 struct sock *sk;
1912
1913 BT_DBG("sock %p", sock);
1914
1915 sock->state = SS_UNCONNECTED;
1916
1917 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM &&
1918 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
1919 return -ESOCKTNOSUPPORT;
1920
1921 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1922 return -EPERM;
1923
1924 sock->ops = &l2cap_sock_ops;
1925
1926 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern);
1927 if (!sk)
1928 return -ENOMEM;
1929
1930 l2cap_sock_init(sk, NULL);
1931 bt_sock_link(&l2cap_sk_list, sk);
1932 return 0;
1933 }
1934
1935 static const struct proto_ops l2cap_sock_ops = {
1936 .family = PF_BLUETOOTH,
1937 .owner = THIS_MODULE,
1938 .release = l2cap_sock_release,
1939 .bind = l2cap_sock_bind,
1940 .connect = l2cap_sock_connect,
1941 .listen = l2cap_sock_listen,
1942 .accept = l2cap_sock_accept,
1943 .getname = l2cap_sock_getname,
1944 .sendmsg = l2cap_sock_sendmsg,
1945 .recvmsg = l2cap_sock_recvmsg,
1946 .poll = bt_sock_poll,
1947 .ioctl = bt_sock_ioctl,
1948 .gettstamp = sock_gettstamp,
1949 .mmap = sock_no_mmap,
1950 .socketpair = sock_no_socketpair,
1951 .shutdown = l2cap_sock_shutdown,
1952 .setsockopt = l2cap_sock_setsockopt,
1953 .getsockopt = l2cap_sock_getsockopt
1954 };
1955
1956 static const struct net_proto_family l2cap_sock_family_ops = {
1957 .family = PF_BLUETOOTH,
1958 .owner = THIS_MODULE,
1959 .create = l2cap_sock_create,
1960 };
1961
l2cap_init_sockets(void)1962 int __init l2cap_init_sockets(void)
1963 {
1964 int err;
1965
1966 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr));
1967
1968 err = proto_register(&l2cap_proto, 0);
1969 if (err < 0)
1970 return err;
1971
1972 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops);
1973 if (err < 0) {
1974 BT_ERR("L2CAP socket registration failed");
1975 goto error;
1976 }
1977
1978 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list,
1979 NULL);
1980 if (err < 0) {
1981 BT_ERR("Failed to create L2CAP proc file");
1982 bt_sock_unregister(BTPROTO_L2CAP);
1983 goto error;
1984 }
1985
1986 BT_INFO("L2CAP socket layer initialized");
1987
1988 return 0;
1989
1990 error:
1991 proto_unregister(&l2cap_proto);
1992 return err;
1993 }
1994
l2cap_cleanup_sockets(void)1995 void l2cap_cleanup_sockets(void)
1996 {
1997 bt_procfs_cleanup(&init_net, "l2cap");
1998 bt_sock_unregister(BTPROTO_L2CAP);
1999 proto_unregister(&l2cap_proto);
2000 }
2001