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 < L2CAP_LE_MIN_MTU)
714 return false;
715 break;
716
717 default:
718 if (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 chan = l2cap_pi(sk)->chan;
1330 /* prevent chan structure from being freed whilst unlocked */
1331 l2cap_chan_hold(chan);
1332
1333 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
1334
1335 if (chan->mode == L2CAP_MODE_ERTM &&
1336 chan->unacked_frames > 0 &&
1337 chan->state == BT_CONNECTED) {
1338 err = __l2cap_wait_ack(sk, chan);
1339
1340 /* After waiting for ACKs, check whether shutdown
1341 * has already been actioned to close the L2CAP
1342 * link such as by l2cap_disconnection_req().
1343 */
1344 if ((sk->sk_shutdown & how) == how)
1345 goto shutdown_matched;
1346 }
1347
1348 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN
1349 * is already set
1350 */
1351 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1352 sk->sk_shutdown |= RCV_SHUTDOWN;
1353 if ((sk->sk_shutdown & how) == how)
1354 goto shutdown_matched;
1355 }
1356
1357 sk->sk_shutdown |= SEND_SHUTDOWN;
1358 release_sock(sk);
1359
1360 l2cap_chan_lock(chan);
1361 conn = chan->conn;
1362 if (conn)
1363 /* prevent conn structure from being freed */
1364 l2cap_conn_get(conn);
1365 l2cap_chan_unlock(chan);
1366
1367 if (conn)
1368 /* mutex lock must be taken before l2cap_chan_lock() */
1369 mutex_lock(&conn->chan_lock);
1370
1371 l2cap_chan_lock(chan);
1372 l2cap_chan_close(chan, 0);
1373 l2cap_chan_unlock(chan);
1374
1375 if (conn) {
1376 mutex_unlock(&conn->chan_lock);
1377 l2cap_conn_put(conn);
1378 }
1379
1380 lock_sock(sk);
1381
1382 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
1383 !(current->flags & PF_EXITING))
1384 err = bt_sock_wait_state(sk, BT_CLOSED,
1385 sk->sk_lingertime);
1386
1387 shutdown_matched:
1388 l2cap_chan_put(chan);
1389 sock_put(sk);
1390
1391 shutdown_already:
1392 if (!err && sk->sk_err)
1393 err = -sk->sk_err;
1394
1395 release_sock(sk);
1396
1397 BT_DBG("Sock shutdown complete err: %d", err);
1398
1399 return err;
1400 }
1401
l2cap_sock_release(struct socket * sock)1402 static int l2cap_sock_release(struct socket *sock)
1403 {
1404 struct sock *sk = sock->sk;
1405 int err;
1406 struct l2cap_chan *chan;
1407
1408 BT_DBG("sock %p, sk %p", sock, sk);
1409
1410 if (!sk)
1411 return 0;
1412
1413 l2cap_sock_cleanup_listen(sk);
1414 bt_sock_unlink(&l2cap_sk_list, sk);
1415
1416 err = l2cap_sock_shutdown(sock, SHUT_RDWR);
1417 chan = l2cap_pi(sk)->chan;
1418
1419 l2cap_chan_hold(chan);
1420 l2cap_chan_lock(chan);
1421
1422 sock_orphan(sk);
1423 l2cap_sock_kill(sk);
1424
1425 l2cap_chan_unlock(chan);
1426 l2cap_chan_put(chan);
1427
1428 return err;
1429 }
1430
l2cap_sock_cleanup_listen(struct sock * parent)1431 static void l2cap_sock_cleanup_listen(struct sock *parent)
1432 {
1433 struct sock *sk;
1434
1435 BT_DBG("parent %p state %s", parent,
1436 state_to_string(parent->sk_state));
1437
1438 /* Close not yet accepted channels */
1439 while ((sk = bt_accept_dequeue(parent, NULL))) {
1440 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1441
1442 BT_DBG("child chan %p state %s", chan,
1443 state_to_string(chan->state));
1444
1445 l2cap_chan_hold(chan);
1446 l2cap_chan_lock(chan);
1447
1448 __clear_chan_timer(chan);
1449 l2cap_chan_close(chan, ECONNRESET);
1450 l2cap_sock_kill(sk);
1451
1452 l2cap_chan_unlock(chan);
1453 l2cap_chan_put(chan);
1454 }
1455 }
1456
l2cap_sock_new_connection_cb(struct l2cap_chan * chan)1457 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
1458 {
1459 struct sock *sk, *parent = chan->data;
1460
1461 lock_sock(parent);
1462
1463 /* Check for backlog size */
1464 if (sk_acceptq_is_full(parent)) {
1465 BT_DBG("backlog full %d", parent->sk_ack_backlog);
1466 release_sock(parent);
1467 return NULL;
1468 }
1469
1470 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP,
1471 GFP_ATOMIC, 0);
1472 if (!sk) {
1473 release_sock(parent);
1474 return NULL;
1475 }
1476
1477 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP);
1478
1479 l2cap_sock_init(sk, parent);
1480
1481 bt_accept_enqueue(parent, sk, false);
1482
1483 release_sock(parent);
1484
1485 return l2cap_pi(sk)->chan;
1486 }
1487
l2cap_sock_recv_cb(struct l2cap_chan * chan,struct sk_buff * skb)1488 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
1489 {
1490 struct sock *sk;
1491 struct l2cap_pinfo *pi;
1492 int err;
1493
1494 sk = chan->data;
1495 if (!sk)
1496 return -ENXIO;
1497
1498 pi = l2cap_pi(sk);
1499 lock_sock(sk);
1500 if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) {
1501 err = -ENOMEM;
1502 goto done;
1503 }
1504
1505 if (chan->mode != L2CAP_MODE_ERTM &&
1506 chan->mode != L2CAP_MODE_STREAMING &&
1507 chan->mode != L2CAP_MODE_LE_FLOWCTL &&
1508 chan->mode != L2CAP_MODE_EXT_FLOWCTL) {
1509 /* Even if no filter is attached, we could potentially
1510 * get errors from security modules, etc.
1511 */
1512 err = sk_filter(sk, skb);
1513 if (err)
1514 goto done;
1515 }
1516
1517 err = __sock_queue_rcv_skb(sk, skb);
1518
1519 l2cap_publish_rx_avail(chan);
1520
1521 /* For ERTM and LE, handle a skb that doesn't fit into the recv
1522 * buffer. This is important to do because the data frames
1523 * have already been acked, so the skb cannot be discarded.
1524 *
1525 * Notify the l2cap core that the buffer is full, so the
1526 * LOCAL_BUSY state is entered and no more frames are
1527 * acked and reassembled until there is buffer space
1528 * available.
1529 */
1530 if (err < 0 &&
1531 (chan->mode == L2CAP_MODE_ERTM ||
1532 chan->mode == L2CAP_MODE_LE_FLOWCTL ||
1533 chan->mode == L2CAP_MODE_EXT_FLOWCTL)) {
1534 struct l2cap_rx_busy *rx_busy =
1535 kmalloc(sizeof(*rx_busy), GFP_KERNEL);
1536 if (!rx_busy) {
1537 err = -ENOMEM;
1538 goto done;
1539 }
1540 rx_busy->skb = skb;
1541 list_add_tail(&rx_busy->list, &pi->rx_busy);
1542 l2cap_chan_busy(chan, 1);
1543 err = 0;
1544 }
1545
1546 done:
1547 release_sock(sk);
1548
1549 return err;
1550 }
1551
l2cap_sock_close_cb(struct l2cap_chan * chan)1552 static void l2cap_sock_close_cb(struct l2cap_chan *chan)
1553 {
1554 struct sock *sk = chan->data;
1555
1556 if (!sk)
1557 return;
1558
1559 l2cap_sock_kill(sk);
1560 }
1561
l2cap_sock_teardown_cb(struct l2cap_chan * chan,int err)1562 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err)
1563 {
1564 struct sock *sk = chan->data;
1565 struct sock *parent;
1566
1567 if (!sk)
1568 return;
1569
1570 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
1571
1572 /* This callback can be called both for server (BT_LISTEN)
1573 * sockets as well as "normal" ones. To avoid lockdep warnings
1574 * with child socket locking (through l2cap_sock_cleanup_listen)
1575 * we need separation into separate nesting levels. The simplest
1576 * way to accomplish this is to inherit the nesting level used
1577 * for the channel.
1578 */
1579 lock_sock_nested(sk, atomic_read(&chan->nesting));
1580
1581 parent = bt_sk(sk)->parent;
1582
1583 switch (chan->state) {
1584 case BT_OPEN:
1585 case BT_BOUND:
1586 case BT_CLOSED:
1587 break;
1588 case BT_LISTEN:
1589 l2cap_sock_cleanup_listen(sk);
1590 sk->sk_state = BT_CLOSED;
1591 chan->state = BT_CLOSED;
1592
1593 break;
1594 default:
1595 sk->sk_state = BT_CLOSED;
1596 chan->state = BT_CLOSED;
1597
1598 sk->sk_err = err;
1599
1600 if (parent) {
1601 bt_accept_unlink(sk);
1602 parent->sk_data_ready(parent);
1603 } else {
1604 sk->sk_state_change(sk);
1605 }
1606
1607 break;
1608 }
1609 release_sock(sk);
1610
1611 /* Only zap after cleanup to avoid use after free race */
1612 sock_set_flag(sk, SOCK_ZAPPED);
1613
1614 }
1615
l2cap_sock_state_change_cb(struct l2cap_chan * chan,int state,int err)1616 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state,
1617 int err)
1618 {
1619 struct sock *sk = chan->data;
1620
1621 sk->sk_state = state;
1622
1623 if (err)
1624 sk->sk_err = err;
1625 }
1626
l2cap_sock_alloc_skb_cb(struct l2cap_chan * chan,unsigned long hdr_len,unsigned long len,int nb)1627 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan,
1628 unsigned long hdr_len,
1629 unsigned long len, int nb)
1630 {
1631 struct sock *sk = chan->data;
1632 struct sk_buff *skb;
1633 int err;
1634
1635 l2cap_chan_unlock(chan);
1636 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err);
1637 l2cap_chan_lock(chan);
1638
1639 if (!skb)
1640 return ERR_PTR(err);
1641
1642 /* Channel lock is released before requesting new skb and then
1643 * reacquired thus we need to recheck channel state.
1644 */
1645 if (chan->state != BT_CONNECTED) {
1646 kfree_skb(skb);
1647 return ERR_PTR(-ENOTCONN);
1648 }
1649
1650 skb->priority = READ_ONCE(sk->sk_priority);
1651
1652 bt_cb(skb)->l2cap.chan = chan;
1653
1654 return skb;
1655 }
1656
l2cap_sock_ready_cb(struct l2cap_chan * chan)1657 static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
1658 {
1659 struct sock *sk = chan->data;
1660 struct sock *parent;
1661
1662 lock_sock(sk);
1663
1664 parent = bt_sk(sk)->parent;
1665
1666 BT_DBG("sk %p, parent %p", sk, parent);
1667
1668 sk->sk_state = BT_CONNECTED;
1669 sk->sk_state_change(sk);
1670
1671 if (parent)
1672 parent->sk_data_ready(parent);
1673
1674 release_sock(sk);
1675 }
1676
l2cap_sock_defer_cb(struct l2cap_chan * chan)1677 static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
1678 {
1679 struct sock *parent, *sk = chan->data;
1680
1681 lock_sock(sk);
1682
1683 parent = bt_sk(sk)->parent;
1684 if (parent)
1685 parent->sk_data_ready(parent);
1686
1687 release_sock(sk);
1688 }
1689
l2cap_sock_resume_cb(struct l2cap_chan * chan)1690 static void l2cap_sock_resume_cb(struct l2cap_chan *chan)
1691 {
1692 struct sock *sk = chan->data;
1693
1694 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) {
1695 sk->sk_state = BT_CONNECTED;
1696 chan->state = BT_CONNECTED;
1697 }
1698
1699 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1700 sk->sk_state_change(sk);
1701 }
1702
l2cap_sock_set_shutdown_cb(struct l2cap_chan * chan)1703 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan)
1704 {
1705 struct sock *sk = chan->data;
1706
1707 lock_sock(sk);
1708 sk->sk_shutdown = SHUTDOWN_MASK;
1709 release_sock(sk);
1710 }
1711
l2cap_sock_get_sndtimeo_cb(struct l2cap_chan * chan)1712 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
1713 {
1714 struct sock *sk = chan->data;
1715
1716 return sk->sk_sndtimeo;
1717 }
1718
l2cap_sock_get_peer_pid_cb(struct l2cap_chan * chan)1719 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan)
1720 {
1721 struct sock *sk = chan->data;
1722
1723 return sk->sk_peer_pid;
1724 }
1725
l2cap_sock_suspend_cb(struct l2cap_chan * chan)1726 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
1727 {
1728 struct sock *sk = chan->data;
1729
1730 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1731 sk->sk_state_change(sk);
1732 }
1733
l2cap_sock_filter(struct l2cap_chan * chan,struct sk_buff * skb)1734 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb)
1735 {
1736 struct sock *sk = chan->data;
1737
1738 switch (chan->mode) {
1739 case L2CAP_MODE_ERTM:
1740 case L2CAP_MODE_STREAMING:
1741 return sk_filter(sk, skb);
1742 }
1743
1744 return 0;
1745 }
1746
1747 static const struct l2cap_ops l2cap_chan_ops = {
1748 .name = "L2CAP Socket Interface",
1749 .new_connection = l2cap_sock_new_connection_cb,
1750 .recv = l2cap_sock_recv_cb,
1751 .close = l2cap_sock_close_cb,
1752 .teardown = l2cap_sock_teardown_cb,
1753 .state_change = l2cap_sock_state_change_cb,
1754 .ready = l2cap_sock_ready_cb,
1755 .defer = l2cap_sock_defer_cb,
1756 .resume = l2cap_sock_resume_cb,
1757 .suspend = l2cap_sock_suspend_cb,
1758 .set_shutdown = l2cap_sock_set_shutdown_cb,
1759 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
1760 .get_peer_pid = l2cap_sock_get_peer_pid_cb,
1761 .alloc_skb = l2cap_sock_alloc_skb_cb,
1762 .filter = l2cap_sock_filter,
1763 };
1764
l2cap_sock_destruct(struct sock * sk)1765 static void l2cap_sock_destruct(struct sock *sk)
1766 {
1767 struct l2cap_rx_busy *rx_busy, *next;
1768
1769 BT_DBG("sk %p", sk);
1770
1771 if (l2cap_pi(sk)->chan) {
1772 l2cap_pi(sk)->chan->data = NULL;
1773 l2cap_chan_put(l2cap_pi(sk)->chan);
1774 }
1775
1776 list_for_each_entry_safe(rx_busy, next, &l2cap_pi(sk)->rx_busy, list) {
1777 kfree_skb(rx_busy->skb);
1778 list_del(&rx_busy->list);
1779 kfree(rx_busy);
1780 }
1781
1782 skb_queue_purge(&sk->sk_receive_queue);
1783 skb_queue_purge(&sk->sk_write_queue);
1784 }
1785
l2cap_skb_msg_name(struct sk_buff * skb,void * msg_name,int * msg_namelen)1786 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name,
1787 int *msg_namelen)
1788 {
1789 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name);
1790
1791 memset(la, 0, sizeof(struct sockaddr_l2));
1792 la->l2_family = AF_BLUETOOTH;
1793 la->l2_psm = bt_cb(skb)->l2cap.psm;
1794 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr);
1795
1796 *msg_namelen = sizeof(struct sockaddr_l2);
1797 }
1798
l2cap_sock_init(struct sock * sk,struct sock * parent)1799 static void l2cap_sock_init(struct sock *sk, struct sock *parent)
1800 {
1801 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1802
1803 BT_DBG("sk %p", sk);
1804
1805 if (parent) {
1806 struct l2cap_chan *pchan = l2cap_pi(parent)->chan;
1807
1808 sk->sk_type = parent->sk_type;
1809 bt_sk(sk)->flags = bt_sk(parent)->flags;
1810
1811 chan->chan_type = pchan->chan_type;
1812 chan->imtu = pchan->imtu;
1813 chan->omtu = pchan->omtu;
1814 chan->conf_state = pchan->conf_state;
1815 chan->mode = pchan->mode;
1816 chan->fcs = pchan->fcs;
1817 chan->max_tx = pchan->max_tx;
1818 chan->tx_win = pchan->tx_win;
1819 chan->tx_win_max = pchan->tx_win_max;
1820 chan->sec_level = pchan->sec_level;
1821 chan->flags = pchan->flags;
1822 chan->tx_credits = pchan->tx_credits;
1823 chan->rx_credits = pchan->rx_credits;
1824
1825 if (chan->chan_type == L2CAP_CHAN_FIXED) {
1826 chan->scid = pchan->scid;
1827 chan->dcid = pchan->scid;
1828 }
1829
1830 security_sk_clone(parent, sk);
1831 } else {
1832 switch (sk->sk_type) {
1833 case SOCK_RAW:
1834 chan->chan_type = L2CAP_CHAN_RAW;
1835 break;
1836 case SOCK_DGRAM:
1837 chan->chan_type = L2CAP_CHAN_CONN_LESS;
1838 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name;
1839 break;
1840 case SOCK_SEQPACKET:
1841 case SOCK_STREAM:
1842 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
1843 break;
1844 }
1845
1846 chan->imtu = L2CAP_DEFAULT_MTU;
1847 chan->omtu = 0;
1848 if (!disable_ertm && sk->sk_type == SOCK_STREAM) {
1849 chan->mode = L2CAP_MODE_ERTM;
1850 set_bit(CONF_STATE2_DEVICE, &chan->conf_state);
1851 } else {
1852 chan->mode = L2CAP_MODE_BASIC;
1853 }
1854
1855 l2cap_chan_set_defaults(chan);
1856 }
1857
1858 /* Default config options */
1859 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
1860
1861 chan->data = sk;
1862 chan->ops = &l2cap_chan_ops;
1863
1864 l2cap_publish_rx_avail(chan);
1865 }
1866
1867 static struct proto l2cap_proto = {
1868 .name = "L2CAP",
1869 .owner = THIS_MODULE,
1870 .obj_size = sizeof(struct l2cap_pinfo)
1871 };
1872
l2cap_sock_alloc(struct net * net,struct socket * sock,int proto,gfp_t prio,int kern)1873 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
1874 int proto, gfp_t prio, int kern)
1875 {
1876 struct sock *sk;
1877 struct l2cap_chan *chan;
1878
1879 sk = bt_sock_alloc(net, sock, &l2cap_proto, proto, prio, kern);
1880 if (!sk)
1881 return NULL;
1882
1883 sk->sk_destruct = l2cap_sock_destruct;
1884 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT;
1885
1886 INIT_LIST_HEAD(&l2cap_pi(sk)->rx_busy);
1887
1888 chan = l2cap_chan_create();
1889 if (!chan) {
1890 sk_free(sk);
1891 sock->sk = NULL;
1892 return NULL;
1893 }
1894
1895 l2cap_chan_hold(chan);
1896
1897 l2cap_pi(sk)->chan = chan;
1898
1899 return sk;
1900 }
1901
l2cap_sock_create(struct net * net,struct socket * sock,int protocol,int kern)1902 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol,
1903 int kern)
1904 {
1905 struct sock *sk;
1906
1907 BT_DBG("sock %p", sock);
1908
1909 sock->state = SS_UNCONNECTED;
1910
1911 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM &&
1912 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
1913 return -ESOCKTNOSUPPORT;
1914
1915 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1916 return -EPERM;
1917
1918 sock->ops = &l2cap_sock_ops;
1919
1920 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern);
1921 if (!sk)
1922 return -ENOMEM;
1923
1924 l2cap_sock_init(sk, NULL);
1925 bt_sock_link(&l2cap_sk_list, sk);
1926 return 0;
1927 }
1928
1929 static const struct proto_ops l2cap_sock_ops = {
1930 .family = PF_BLUETOOTH,
1931 .owner = THIS_MODULE,
1932 .release = l2cap_sock_release,
1933 .bind = l2cap_sock_bind,
1934 .connect = l2cap_sock_connect,
1935 .listen = l2cap_sock_listen,
1936 .accept = l2cap_sock_accept,
1937 .getname = l2cap_sock_getname,
1938 .sendmsg = l2cap_sock_sendmsg,
1939 .recvmsg = l2cap_sock_recvmsg,
1940 .poll = bt_sock_poll,
1941 .ioctl = bt_sock_ioctl,
1942 .gettstamp = sock_gettstamp,
1943 .mmap = sock_no_mmap,
1944 .socketpair = sock_no_socketpair,
1945 .shutdown = l2cap_sock_shutdown,
1946 .setsockopt = l2cap_sock_setsockopt,
1947 .getsockopt = l2cap_sock_getsockopt
1948 };
1949
1950 static const struct net_proto_family l2cap_sock_family_ops = {
1951 .family = PF_BLUETOOTH,
1952 .owner = THIS_MODULE,
1953 .create = l2cap_sock_create,
1954 };
1955
l2cap_init_sockets(void)1956 int __init l2cap_init_sockets(void)
1957 {
1958 int err;
1959
1960 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr));
1961
1962 err = proto_register(&l2cap_proto, 0);
1963 if (err < 0)
1964 return err;
1965
1966 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops);
1967 if (err < 0) {
1968 BT_ERR("L2CAP socket registration failed");
1969 goto error;
1970 }
1971
1972 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list,
1973 NULL);
1974 if (err < 0) {
1975 BT_ERR("Failed to create L2CAP proc file");
1976 bt_sock_unregister(BTPROTO_L2CAP);
1977 goto error;
1978 }
1979
1980 BT_INFO("L2CAP socket layer initialized");
1981
1982 return 0;
1983
1984 error:
1985 proto_unregister(&l2cap_proto);
1986 return err;
1987 }
1988
l2cap_cleanup_sockets(void)1989 void l2cap_cleanup_sockets(void)
1990 {
1991 bt_procfs_cleanup(&init_net, "l2cap");
1992 bt_sock_unregister(BTPROTO_L2CAP);
1993 proto_unregister(&l2cap_proto);
1994 }
1995