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
l2cap_is_socket(struct socket * sock)50 bool l2cap_is_socket(struct socket *sock)
51 {
52 return sock && sock->ops == &l2cap_sock_ops;
53 }
54 EXPORT_SYMBOL(l2cap_is_socket);
55
l2cap_validate_bredr_psm(u16 psm)56 static int l2cap_validate_bredr_psm(u16 psm)
57 {
58 /* PSM must be odd and lsb of upper byte must be 0 */
59 if ((psm & 0x0101) != 0x0001)
60 return -EINVAL;
61
62 /* Restrict usage of well-known PSMs */
63 if (psm < L2CAP_PSM_DYN_START && !capable(CAP_NET_BIND_SERVICE))
64 return -EACCES;
65
66 return 0;
67 }
68
l2cap_validate_le_psm(u16 psm)69 static int l2cap_validate_le_psm(u16 psm)
70 {
71 /* Valid LE_PSM ranges are defined only until 0x00ff */
72 if (psm > L2CAP_PSM_LE_DYN_END)
73 return -EINVAL;
74
75 /* Restrict fixed, SIG assigned PSM values to CAP_NET_BIND_SERVICE */
76 if (psm < L2CAP_PSM_LE_DYN_START && !capable(CAP_NET_BIND_SERVICE))
77 return -EACCES;
78
79 return 0;
80 }
81
l2cap_sock_bind(struct socket * sock,struct sockaddr * addr,int alen)82 static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
83 {
84 struct sock *sk = sock->sk;
85 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
86 struct sockaddr_l2 la;
87 int len, err = 0;
88
89 BT_DBG("sk %p", sk);
90
91 if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
92 addr->sa_family != AF_BLUETOOTH)
93 return -EINVAL;
94
95 memset(&la, 0, sizeof(la));
96 len = min_t(unsigned int, sizeof(la), alen);
97 memcpy(&la, addr, len);
98
99 if (la.l2_cid && la.l2_psm)
100 return -EINVAL;
101
102 if (!bdaddr_type_is_valid(la.l2_bdaddr_type))
103 return -EINVAL;
104
105 if (bdaddr_type_is_le(la.l2_bdaddr_type)) {
106 /* We only allow ATT user space socket */
107 if (la.l2_cid &&
108 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
109 return -EINVAL;
110 }
111
112 lock_sock(sk);
113
114 if (sk->sk_state != BT_OPEN) {
115 err = -EBADFD;
116 goto done;
117 }
118
119 if (la.l2_psm) {
120 __u16 psm = __le16_to_cpu(la.l2_psm);
121
122 if (la.l2_bdaddr_type == BDADDR_BREDR)
123 err = l2cap_validate_bredr_psm(psm);
124 else
125 err = l2cap_validate_le_psm(psm);
126
127 if (err)
128 goto done;
129 }
130
131 bacpy(&chan->src, &la.l2_bdaddr);
132 chan->src_type = la.l2_bdaddr_type;
133
134 if (la.l2_cid)
135 err = l2cap_add_scid(chan, __le16_to_cpu(la.l2_cid));
136 else
137 err = l2cap_add_psm(chan, &la.l2_bdaddr, la.l2_psm);
138
139 if (err < 0)
140 goto done;
141
142 switch (chan->chan_type) {
143 case L2CAP_CHAN_CONN_LESS:
144 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_3DSP)
145 chan->sec_level = BT_SECURITY_SDP;
146 break;
147 case L2CAP_CHAN_CONN_ORIENTED:
148 if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_SDP ||
149 __le16_to_cpu(la.l2_psm) == L2CAP_PSM_RFCOMM)
150 chan->sec_level = BT_SECURITY_SDP;
151 break;
152 case L2CAP_CHAN_RAW:
153 chan->sec_level = BT_SECURITY_SDP;
154 break;
155 case L2CAP_CHAN_FIXED:
156 /* Fixed channels default to the L2CAP core not holding a
157 * hci_conn reference for them. For fixed channels mapping to
158 * L2CAP sockets we do want to hold a reference so set the
159 * appropriate flag to request it.
160 */
161 set_bit(FLAG_HOLD_HCI_CONN, &chan->flags);
162 break;
163 }
164
165 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and
166 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set.
167 */
168 if (chan->psm && bdaddr_type_is_le(chan->src_type) &&
169 chan->mode != L2CAP_MODE_EXT_FLOWCTL)
170 chan->mode = L2CAP_MODE_LE_FLOWCTL;
171
172 chan->state = BT_BOUND;
173 sk->sk_state = BT_BOUND;
174
175 done:
176 release_sock(sk);
177 return err;
178 }
179
l2cap_sock_init_pid(struct sock * sk)180 static void l2cap_sock_init_pid(struct sock *sk)
181 {
182 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
183
184 /* Only L2CAP_MODE_EXT_FLOWCTL ever need to access the PID in order to
185 * group the channels being requested.
186 */
187 if (chan->mode != L2CAP_MODE_EXT_FLOWCTL)
188 return;
189
190 spin_lock(&sk->sk_peer_lock);
191 sk->sk_peer_pid = get_pid(task_tgid(current));
192 spin_unlock(&sk->sk_peer_lock);
193 }
194
l2cap_sock_connect(struct socket * sock,struct sockaddr * addr,int alen,int flags)195 static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
196 int alen, int flags)
197 {
198 struct sock *sk = sock->sk;
199 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
200 struct sockaddr_l2 la;
201 int len, err = 0;
202 bool zapped;
203
204 BT_DBG("sk %p", sk);
205
206 lock_sock(sk);
207 zapped = sock_flag(sk, SOCK_ZAPPED);
208 release_sock(sk);
209
210 if (zapped)
211 return -EINVAL;
212
213 if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
214 addr->sa_family != AF_BLUETOOTH)
215 return -EINVAL;
216
217 memset(&la, 0, sizeof(la));
218 len = min_t(unsigned int, sizeof(la), alen);
219 memcpy(&la, addr, len);
220
221 if (la.l2_cid && la.l2_psm)
222 return -EINVAL;
223
224 if (!bdaddr_type_is_valid(la.l2_bdaddr_type))
225 return -EINVAL;
226
227 /* Check that the socket wasn't bound to something that
228 * conflicts with the address given to connect(). If chan->src
229 * is BDADDR_ANY it means bind() was never used, in which case
230 * chan->src_type and la.l2_bdaddr_type do not need to match.
231 */
232 if (chan->src_type == BDADDR_BREDR && bacmp(&chan->src, BDADDR_ANY) &&
233 bdaddr_type_is_le(la.l2_bdaddr_type)) {
234 /* Old user space versions will try to incorrectly bind
235 * the ATT socket using BDADDR_BREDR. We need to accept
236 * this and fix up the source address type only when
237 * both the source CID and destination CID indicate
238 * ATT. Anything else is an invalid combination.
239 */
240 if (chan->scid != L2CAP_CID_ATT ||
241 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
242 return -EINVAL;
243
244 /* We don't have the hdev available here to make a
245 * better decision on random vs public, but since all
246 * user space versions that exhibit this issue anyway do
247 * not support random local addresses assuming public
248 * here is good enough.
249 */
250 chan->src_type = BDADDR_LE_PUBLIC;
251 }
252
253 if (chan->src_type != BDADDR_BREDR && la.l2_bdaddr_type == BDADDR_BREDR)
254 return -EINVAL;
255
256 if (bdaddr_type_is_le(la.l2_bdaddr_type)) {
257 /* We only allow ATT user space socket */
258 if (la.l2_cid &&
259 la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
260 return -EINVAL;
261 }
262
263 /* Use L2CAP_MODE_LE_FLOWCTL (CoC) in case of LE address and
264 * L2CAP_MODE_EXT_FLOWCTL (ECRED) has not been set.
265 */
266 if (chan->psm && bdaddr_type_is_le(chan->src_type) &&
267 chan->mode != L2CAP_MODE_EXT_FLOWCTL)
268 chan->mode = L2CAP_MODE_LE_FLOWCTL;
269
270 l2cap_sock_init_pid(sk);
271
272 err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid),
273 &la.l2_bdaddr, la.l2_bdaddr_type);
274 if (err)
275 return err;
276
277 lock_sock(sk);
278
279 err = bt_sock_wait_state(sk, BT_CONNECTED,
280 sock_sndtimeo(sk, flags & O_NONBLOCK));
281
282 release_sock(sk);
283
284 return err;
285 }
286
l2cap_sock_listen(struct socket * sock,int backlog)287 static int l2cap_sock_listen(struct socket *sock, int backlog)
288 {
289 struct sock *sk = sock->sk;
290 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
291 int err = 0;
292
293 BT_DBG("sk %p backlog %d", sk, backlog);
294
295 lock_sock(sk);
296
297 if (sk->sk_state != BT_BOUND) {
298 err = -EBADFD;
299 goto done;
300 }
301
302 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM) {
303 err = -EINVAL;
304 goto done;
305 }
306
307 switch (chan->mode) {
308 case L2CAP_MODE_BASIC:
309 case L2CAP_MODE_LE_FLOWCTL:
310 break;
311 case L2CAP_MODE_EXT_FLOWCTL:
312 if (!enable_ecred) {
313 err = -EOPNOTSUPP;
314 goto done;
315 }
316 break;
317 case L2CAP_MODE_ERTM:
318 case L2CAP_MODE_STREAMING:
319 if (!disable_ertm)
320 break;
321 fallthrough;
322 default:
323 err = -EOPNOTSUPP;
324 goto done;
325 }
326
327 l2cap_sock_init_pid(sk);
328
329 sk->sk_max_ack_backlog = backlog;
330 sk->sk_ack_backlog = 0;
331
332 /* Listening channels need to use nested locking in order not to
333 * cause lockdep warnings when the created child channels end up
334 * being locked in the same thread as the parent channel.
335 */
336 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
337
338 chan->state = BT_LISTEN;
339 sk->sk_state = BT_LISTEN;
340
341 done:
342 release_sock(sk);
343 return err;
344 }
345
l2cap_sock_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)346 static int l2cap_sock_accept(struct socket *sock, struct socket *newsock,
347 int flags, bool kern)
348 {
349 DEFINE_WAIT_FUNC(wait, woken_wake_function);
350 struct sock *sk = sock->sk, *nsk;
351 long timeo;
352 int err = 0;
353
354 lock_sock_nested(sk, L2CAP_NESTING_PARENT);
355
356 timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
357
358 BT_DBG("sk %p timeo %ld", sk, timeo);
359
360 /* Wait for an incoming connection. (wake-one). */
361 add_wait_queue_exclusive(sk_sleep(sk), &wait);
362 while (1) {
363 if (sk->sk_state != BT_LISTEN) {
364 err = -EBADFD;
365 break;
366 }
367
368 nsk = bt_accept_dequeue(sk, newsock);
369 if (nsk)
370 break;
371
372 if (!timeo) {
373 err = -EAGAIN;
374 break;
375 }
376
377 if (signal_pending(current)) {
378 err = sock_intr_errno(timeo);
379 break;
380 }
381
382 release_sock(sk);
383
384 timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
385
386 lock_sock_nested(sk, L2CAP_NESTING_PARENT);
387 }
388 remove_wait_queue(sk_sleep(sk), &wait);
389
390 if (err)
391 goto done;
392
393 newsock->state = SS_CONNECTED;
394
395 BT_DBG("new socket %p", nsk);
396
397 done:
398 release_sock(sk);
399 return err;
400 }
401
l2cap_sock_getname(struct socket * sock,struct sockaddr * addr,int peer)402 static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr,
403 int peer)
404 {
405 struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr;
406 struct sock *sk = sock->sk;
407 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
408
409 BT_DBG("sock %p, sk %p", sock, sk);
410
411 if (peer && sk->sk_state != BT_CONNECTED &&
412 sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2 &&
413 sk->sk_state != BT_CONFIG)
414 return -ENOTCONN;
415
416 memset(la, 0, sizeof(struct sockaddr_l2));
417 addr->sa_family = AF_BLUETOOTH;
418
419 la->l2_psm = chan->psm;
420
421 if (peer) {
422 bacpy(&la->l2_bdaddr, &chan->dst);
423 la->l2_cid = cpu_to_le16(chan->dcid);
424 la->l2_bdaddr_type = chan->dst_type;
425 } else {
426 bacpy(&la->l2_bdaddr, &chan->src);
427 la->l2_cid = cpu_to_le16(chan->scid);
428 la->l2_bdaddr_type = chan->src_type;
429 }
430
431 return sizeof(struct sockaddr_l2);
432 }
433
l2cap_get_mode(struct l2cap_chan * chan)434 static int l2cap_get_mode(struct l2cap_chan *chan)
435 {
436 switch (chan->mode) {
437 case L2CAP_MODE_BASIC:
438 return BT_MODE_BASIC;
439 case L2CAP_MODE_ERTM:
440 return BT_MODE_ERTM;
441 case L2CAP_MODE_STREAMING:
442 return BT_MODE_STREAMING;
443 case L2CAP_MODE_LE_FLOWCTL:
444 return BT_MODE_LE_FLOWCTL;
445 case L2CAP_MODE_EXT_FLOWCTL:
446 return BT_MODE_EXT_FLOWCTL;
447 }
448
449 return -EINVAL;
450 }
451
l2cap_sock_getsockopt_old(struct socket * sock,int optname,char __user * optval,int __user * optlen)452 static int l2cap_sock_getsockopt_old(struct socket *sock, int optname,
453 char __user *optval, int __user *optlen)
454 {
455 struct sock *sk = sock->sk;
456 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
457 struct l2cap_options opts;
458 struct l2cap_conninfo cinfo;
459 int len, err = 0;
460 u32 opt;
461
462 BT_DBG("sk %p", sk);
463
464 if (get_user(len, optlen))
465 return -EFAULT;
466
467 lock_sock(sk);
468
469 switch (optname) {
470 case L2CAP_OPTIONS:
471 /* LE sockets should use BT_SNDMTU/BT_RCVMTU, but since
472 * legacy ATT code depends on getsockopt for
473 * L2CAP_OPTIONS we need to let this pass.
474 */
475 if (bdaddr_type_is_le(chan->src_type) &&
476 chan->scid != L2CAP_CID_ATT) {
477 err = -EINVAL;
478 break;
479 }
480
481 /* Only BR/EDR modes are supported here */
482 switch (chan->mode) {
483 case L2CAP_MODE_BASIC:
484 case L2CAP_MODE_ERTM:
485 case L2CAP_MODE_STREAMING:
486 break;
487 default:
488 err = -EINVAL;
489 break;
490 }
491
492 if (err < 0)
493 break;
494
495 memset(&opts, 0, sizeof(opts));
496 opts.imtu = chan->imtu;
497 opts.omtu = chan->omtu;
498 opts.flush_to = chan->flush_to;
499 opts.mode = chan->mode;
500 opts.fcs = chan->fcs;
501 opts.max_tx = chan->max_tx;
502 opts.txwin_size = chan->tx_win;
503
504 BT_DBG("mode 0x%2.2x", chan->mode);
505
506 len = min_t(unsigned int, len, sizeof(opts));
507 if (copy_to_user(optval, (char *) &opts, len))
508 err = -EFAULT;
509
510 break;
511
512 case L2CAP_LM:
513 switch (chan->sec_level) {
514 case BT_SECURITY_LOW:
515 opt = L2CAP_LM_AUTH;
516 break;
517 case BT_SECURITY_MEDIUM:
518 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT;
519 break;
520 case BT_SECURITY_HIGH:
521 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT |
522 L2CAP_LM_SECURE;
523 break;
524 case BT_SECURITY_FIPS:
525 opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT |
526 L2CAP_LM_SECURE | L2CAP_LM_FIPS;
527 break;
528 default:
529 opt = 0;
530 break;
531 }
532
533 if (test_bit(FLAG_ROLE_SWITCH, &chan->flags))
534 opt |= L2CAP_LM_MASTER;
535
536 if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
537 opt |= L2CAP_LM_RELIABLE;
538
539 if (put_user(opt, (u32 __user *) optval))
540 err = -EFAULT;
541
542 break;
543
544 case L2CAP_CONNINFO:
545 if (sk->sk_state != BT_CONNECTED &&
546 !(sk->sk_state == BT_CONNECT2 &&
547 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags))) {
548 err = -ENOTCONN;
549 break;
550 }
551
552 memset(&cinfo, 0, sizeof(cinfo));
553 cinfo.hci_handle = chan->conn->hcon->handle;
554 memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3);
555
556 len = min_t(unsigned int, len, sizeof(cinfo));
557 if (copy_to_user(optval, (char *) &cinfo, len))
558 err = -EFAULT;
559
560 break;
561
562 default:
563 err = -ENOPROTOOPT;
564 break;
565 }
566
567 release_sock(sk);
568 return err;
569 }
570
l2cap_sock_getsockopt(struct socket * sock,int level,int optname,char __user * optval,int __user * optlen)571 static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname,
572 char __user *optval, int __user *optlen)
573 {
574 struct sock *sk = sock->sk;
575 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
576 struct bt_security sec;
577 struct bt_power pwr;
578 u32 phys;
579 int len, mode, err = 0;
580
581 BT_DBG("sk %p", sk);
582
583 if (level == SOL_L2CAP)
584 return l2cap_sock_getsockopt_old(sock, optname, optval, optlen);
585
586 if (level != SOL_BLUETOOTH)
587 return -ENOPROTOOPT;
588
589 if (get_user(len, optlen))
590 return -EFAULT;
591
592 lock_sock(sk);
593
594 switch (optname) {
595 case BT_SECURITY:
596 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
597 chan->chan_type != L2CAP_CHAN_FIXED &&
598 chan->chan_type != L2CAP_CHAN_RAW) {
599 err = -EINVAL;
600 break;
601 }
602
603 memset(&sec, 0, sizeof(sec));
604 if (chan->conn) {
605 sec.level = chan->conn->hcon->sec_level;
606
607 if (sk->sk_state == BT_CONNECTED)
608 sec.key_size = chan->conn->hcon->enc_key_size;
609 } else {
610 sec.level = chan->sec_level;
611 }
612
613 len = min_t(unsigned int, len, sizeof(sec));
614 if (copy_to_user(optval, (char *) &sec, len))
615 err = -EFAULT;
616
617 break;
618
619 case BT_DEFER_SETUP:
620 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
621 err = -EINVAL;
622 break;
623 }
624
625 if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
626 (u32 __user *) optval))
627 err = -EFAULT;
628
629 break;
630
631 case BT_FLUSHABLE:
632 if (put_user(test_bit(FLAG_FLUSHABLE, &chan->flags),
633 (u32 __user *) optval))
634 err = -EFAULT;
635
636 break;
637
638 case BT_POWER:
639 if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM
640 && sk->sk_type != SOCK_RAW) {
641 err = -EINVAL;
642 break;
643 }
644
645 pwr.force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
646
647 len = min_t(unsigned int, len, sizeof(pwr));
648 if (copy_to_user(optval, (char *) &pwr, len))
649 err = -EFAULT;
650
651 break;
652
653 case BT_CHANNEL_POLICY:
654 if (put_user(chan->chan_policy, (u32 __user *) optval))
655 err = -EFAULT;
656 break;
657
658 case BT_SNDMTU:
659 if (!bdaddr_type_is_le(chan->src_type)) {
660 err = -EINVAL;
661 break;
662 }
663
664 if (sk->sk_state != BT_CONNECTED) {
665 err = -ENOTCONN;
666 break;
667 }
668
669 if (put_user(chan->omtu, (u16 __user *) optval))
670 err = -EFAULT;
671 break;
672
673 case BT_RCVMTU:
674 if (!bdaddr_type_is_le(chan->src_type)) {
675 err = -EINVAL;
676 break;
677 }
678
679 if (put_user(chan->imtu, (u16 __user *) optval))
680 err = -EFAULT;
681 break;
682
683 case BT_PHY:
684 if (sk->sk_state != BT_CONNECTED) {
685 err = -ENOTCONN;
686 break;
687 }
688
689 phys = hci_conn_get_phy(chan->conn->hcon);
690
691 if (put_user(phys, (u32 __user *) optval))
692 err = -EFAULT;
693 break;
694
695 case BT_MODE:
696 if (!enable_ecred) {
697 err = -ENOPROTOOPT;
698 break;
699 }
700
701 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
702 err = -EINVAL;
703 break;
704 }
705
706 mode = l2cap_get_mode(chan);
707 if (mode < 0) {
708 err = mode;
709 break;
710 }
711
712 if (put_user(mode, (u8 __user *) optval))
713 err = -EFAULT;
714 break;
715
716 default:
717 err = -ENOPROTOOPT;
718 break;
719 }
720
721 release_sock(sk);
722 return err;
723 }
724
l2cap_valid_mtu(struct l2cap_chan * chan,u16 mtu)725 static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu)
726 {
727 switch (chan->scid) {
728 case L2CAP_CID_ATT:
729 if (mtu < L2CAP_LE_MIN_MTU)
730 return false;
731 break;
732
733 default:
734 if (mtu < L2CAP_DEFAULT_MIN_MTU)
735 return false;
736 }
737
738 return true;
739 }
740
l2cap_sock_setsockopt_old(struct socket * sock,int optname,sockptr_t optval,unsigned int optlen)741 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname,
742 sockptr_t optval, unsigned int optlen)
743 {
744 struct sock *sk = sock->sk;
745 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
746 struct l2cap_options opts;
747 int len, err = 0;
748 u32 opt;
749
750 BT_DBG("sk %p", sk);
751
752 lock_sock(sk);
753
754 switch (optname) {
755 case L2CAP_OPTIONS:
756 if (bdaddr_type_is_le(chan->src_type)) {
757 err = -EINVAL;
758 break;
759 }
760
761 if (sk->sk_state == BT_CONNECTED) {
762 err = -EINVAL;
763 break;
764 }
765
766 opts.imtu = chan->imtu;
767 opts.omtu = chan->omtu;
768 opts.flush_to = chan->flush_to;
769 opts.mode = chan->mode;
770 opts.fcs = chan->fcs;
771 opts.max_tx = chan->max_tx;
772 opts.txwin_size = chan->tx_win;
773
774 len = min_t(unsigned int, sizeof(opts), optlen);
775 if (copy_from_sockptr(&opts, optval, len)) {
776 err = -EFAULT;
777 break;
778 }
779
780 if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) {
781 err = -EINVAL;
782 break;
783 }
784
785 if (!l2cap_valid_mtu(chan, opts.imtu)) {
786 err = -EINVAL;
787 break;
788 }
789
790 /* Only BR/EDR modes are supported here */
791 switch (opts.mode) {
792 case L2CAP_MODE_BASIC:
793 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state);
794 break;
795 case L2CAP_MODE_ERTM:
796 case L2CAP_MODE_STREAMING:
797 if (!disable_ertm)
798 break;
799 fallthrough;
800 default:
801 err = -EINVAL;
802 break;
803 }
804
805 if (err < 0)
806 break;
807
808 chan->mode = opts.mode;
809
810 BT_DBG("mode 0x%2.2x", chan->mode);
811
812 chan->imtu = opts.imtu;
813 chan->omtu = opts.omtu;
814 chan->fcs = opts.fcs;
815 chan->max_tx = opts.max_tx;
816 chan->tx_win = opts.txwin_size;
817 chan->flush_to = opts.flush_to;
818 break;
819
820 case L2CAP_LM:
821 if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
822 err = -EFAULT;
823 break;
824 }
825
826 if (opt & L2CAP_LM_FIPS) {
827 err = -EINVAL;
828 break;
829 }
830
831 if (opt & L2CAP_LM_AUTH)
832 chan->sec_level = BT_SECURITY_LOW;
833 if (opt & L2CAP_LM_ENCRYPT)
834 chan->sec_level = BT_SECURITY_MEDIUM;
835 if (opt & L2CAP_LM_SECURE)
836 chan->sec_level = BT_SECURITY_HIGH;
837
838 if (opt & L2CAP_LM_MASTER)
839 set_bit(FLAG_ROLE_SWITCH, &chan->flags);
840 else
841 clear_bit(FLAG_ROLE_SWITCH, &chan->flags);
842
843 if (opt & L2CAP_LM_RELIABLE)
844 set_bit(FLAG_FORCE_RELIABLE, &chan->flags);
845 else
846 clear_bit(FLAG_FORCE_RELIABLE, &chan->flags);
847 break;
848
849 default:
850 err = -ENOPROTOOPT;
851 break;
852 }
853
854 release_sock(sk);
855 return err;
856 }
857
l2cap_set_mode(struct l2cap_chan * chan,u8 mode)858 static int l2cap_set_mode(struct l2cap_chan *chan, u8 mode)
859 {
860 switch (mode) {
861 case BT_MODE_BASIC:
862 if (bdaddr_type_is_le(chan->src_type))
863 return -EINVAL;
864 mode = L2CAP_MODE_BASIC;
865 clear_bit(CONF_STATE2_DEVICE, &chan->conf_state);
866 break;
867 case BT_MODE_ERTM:
868 if (!disable_ertm || bdaddr_type_is_le(chan->src_type))
869 return -EINVAL;
870 mode = L2CAP_MODE_ERTM;
871 break;
872 case BT_MODE_STREAMING:
873 if (!disable_ertm || bdaddr_type_is_le(chan->src_type))
874 return -EINVAL;
875 mode = L2CAP_MODE_STREAMING;
876 break;
877 case BT_MODE_LE_FLOWCTL:
878 if (!bdaddr_type_is_le(chan->src_type))
879 return -EINVAL;
880 mode = L2CAP_MODE_LE_FLOWCTL;
881 break;
882 case BT_MODE_EXT_FLOWCTL:
883 /* TODO: Add support for ECRED PDUs to BR/EDR */
884 if (!bdaddr_type_is_le(chan->src_type))
885 return -EINVAL;
886 mode = L2CAP_MODE_EXT_FLOWCTL;
887 break;
888 default:
889 return -EINVAL;
890 }
891
892 chan->mode = mode;
893
894 return 0;
895 }
896
l2cap_sock_setsockopt(struct socket * sock,int level,int optname,sockptr_t optval,unsigned int optlen)897 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
898 sockptr_t optval, unsigned int optlen)
899 {
900 struct sock *sk = sock->sk;
901 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
902 struct bt_security sec;
903 struct bt_power pwr;
904 struct l2cap_conn *conn;
905 int len, err = 0;
906 u32 opt;
907 u16 mtu;
908 u8 mode;
909
910 BT_DBG("sk %p", sk);
911
912 if (level == SOL_L2CAP)
913 return l2cap_sock_setsockopt_old(sock, optname, optval, optlen);
914
915 if (level != SOL_BLUETOOTH)
916 return -ENOPROTOOPT;
917
918 lock_sock(sk);
919
920 switch (optname) {
921 case BT_SECURITY:
922 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
923 chan->chan_type != L2CAP_CHAN_FIXED &&
924 chan->chan_type != L2CAP_CHAN_RAW) {
925 err = -EINVAL;
926 break;
927 }
928
929 sec.level = BT_SECURITY_LOW;
930
931 len = min_t(unsigned int, sizeof(sec), optlen);
932 if (copy_from_sockptr(&sec, optval, len)) {
933 err = -EFAULT;
934 break;
935 }
936
937 if (sec.level < BT_SECURITY_LOW ||
938 sec.level > BT_SECURITY_FIPS) {
939 err = -EINVAL;
940 break;
941 }
942
943 chan->sec_level = sec.level;
944
945 if (!chan->conn)
946 break;
947
948 conn = chan->conn;
949
950 /* change security for LE channels */
951 if (chan->scid == L2CAP_CID_ATT) {
952 if (smp_conn_security(conn->hcon, sec.level)) {
953 err = -EINVAL;
954 break;
955 }
956
957 set_bit(FLAG_PENDING_SECURITY, &chan->flags);
958 sk->sk_state = BT_CONFIG;
959 chan->state = BT_CONFIG;
960
961 /* or for ACL link */
962 } else if ((sk->sk_state == BT_CONNECT2 &&
963 test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) ||
964 sk->sk_state == BT_CONNECTED) {
965 if (!l2cap_chan_check_security(chan, true))
966 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
967 else
968 sk->sk_state_change(sk);
969 } else {
970 err = -EINVAL;
971 }
972 break;
973
974 case BT_DEFER_SETUP:
975 if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
976 err = -EINVAL;
977 break;
978 }
979
980 if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
981 err = -EFAULT;
982 break;
983 }
984
985 if (opt) {
986 set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
987 set_bit(FLAG_DEFER_SETUP, &chan->flags);
988 } else {
989 clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
990 clear_bit(FLAG_DEFER_SETUP, &chan->flags);
991 }
992 break;
993
994 case BT_FLUSHABLE:
995 if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
996 err = -EFAULT;
997 break;
998 }
999
1000 if (opt > BT_FLUSHABLE_ON) {
1001 err = -EINVAL;
1002 break;
1003 }
1004
1005 if (opt == BT_FLUSHABLE_OFF) {
1006 conn = chan->conn;
1007 /* proceed further only when we have l2cap_conn and
1008 No Flush support in the LM */
1009 if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) {
1010 err = -EINVAL;
1011 break;
1012 }
1013 }
1014
1015 if (opt)
1016 set_bit(FLAG_FLUSHABLE, &chan->flags);
1017 else
1018 clear_bit(FLAG_FLUSHABLE, &chan->flags);
1019 break;
1020
1021 case BT_POWER:
1022 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
1023 chan->chan_type != L2CAP_CHAN_RAW) {
1024 err = -EINVAL;
1025 break;
1026 }
1027
1028 pwr.force_active = BT_POWER_FORCE_ACTIVE_ON;
1029
1030 len = min_t(unsigned int, sizeof(pwr), optlen);
1031 if (copy_from_sockptr(&pwr, optval, len)) {
1032 err = -EFAULT;
1033 break;
1034 }
1035
1036 if (pwr.force_active)
1037 set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
1038 else
1039 clear_bit(FLAG_FORCE_ACTIVE, &chan->flags);
1040 break;
1041
1042 case BT_CHANNEL_POLICY:
1043 if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
1044 err = -EFAULT;
1045 break;
1046 }
1047
1048 if (opt > BT_CHANNEL_POLICY_AMP_PREFERRED) {
1049 err = -EINVAL;
1050 break;
1051 }
1052
1053 if (chan->mode != L2CAP_MODE_ERTM &&
1054 chan->mode != L2CAP_MODE_STREAMING) {
1055 err = -EOPNOTSUPP;
1056 break;
1057 }
1058
1059 chan->chan_policy = (u8) opt;
1060
1061 if (sk->sk_state == BT_CONNECTED &&
1062 chan->move_role == L2CAP_MOVE_ROLE_NONE)
1063 l2cap_move_start(chan);
1064
1065 break;
1066
1067 case BT_SNDMTU:
1068 if (!bdaddr_type_is_le(chan->src_type)) {
1069 err = -EINVAL;
1070 break;
1071 }
1072
1073 /* Setting is not supported as it's the remote side that
1074 * decides this.
1075 */
1076 err = -EPERM;
1077 break;
1078
1079 case BT_RCVMTU:
1080 if (!bdaddr_type_is_le(chan->src_type)) {
1081 err = -EINVAL;
1082 break;
1083 }
1084
1085 if (chan->mode == L2CAP_MODE_LE_FLOWCTL &&
1086 sk->sk_state == BT_CONNECTED) {
1087 err = -EISCONN;
1088 break;
1089 }
1090
1091 if (copy_from_sockptr(&mtu, optval, sizeof(u16))) {
1092 err = -EFAULT;
1093 break;
1094 }
1095
1096 if (chan->mode == L2CAP_MODE_EXT_FLOWCTL &&
1097 sk->sk_state == BT_CONNECTED)
1098 err = l2cap_chan_reconfigure(chan, mtu);
1099 else
1100 chan->imtu = mtu;
1101
1102 break;
1103
1104 case BT_MODE:
1105 if (!enable_ecred) {
1106 err = -ENOPROTOOPT;
1107 break;
1108 }
1109
1110 BT_DBG("sk->sk_state %u", sk->sk_state);
1111
1112 if (sk->sk_state != BT_BOUND) {
1113 err = -EINVAL;
1114 break;
1115 }
1116
1117 if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
1118 err = -EINVAL;
1119 break;
1120 }
1121
1122 if (copy_from_sockptr(&mode, optval, sizeof(u8))) {
1123 err = -EFAULT;
1124 break;
1125 }
1126
1127 BT_DBG("mode %u", mode);
1128
1129 err = l2cap_set_mode(chan, mode);
1130 if (err)
1131 break;
1132
1133 BT_DBG("mode 0x%2.2x", chan->mode);
1134
1135 break;
1136
1137 default:
1138 err = -ENOPROTOOPT;
1139 break;
1140 }
1141
1142 release_sock(sk);
1143 return err;
1144 }
1145
l2cap_sock_sendmsg(struct socket * sock,struct msghdr * msg,size_t len)1146 static int l2cap_sock_sendmsg(struct socket *sock, struct msghdr *msg,
1147 size_t len)
1148 {
1149 struct sock *sk = sock->sk;
1150 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1151 int err;
1152
1153 BT_DBG("sock %p, sk %p", sock, sk);
1154
1155 err = sock_error(sk);
1156 if (err)
1157 return err;
1158
1159 if (msg->msg_flags & MSG_OOB)
1160 return -EOPNOTSUPP;
1161
1162 if (sk->sk_state != BT_CONNECTED)
1163 return -ENOTCONN;
1164
1165 lock_sock(sk);
1166 err = bt_sock_wait_ready(sk, msg->msg_flags);
1167 release_sock(sk);
1168 if (err)
1169 return err;
1170
1171 l2cap_chan_lock(chan);
1172 err = l2cap_chan_send(chan, msg, len);
1173 l2cap_chan_unlock(chan);
1174
1175 return err;
1176 }
1177
l2cap_sock_recvmsg(struct socket * sock,struct msghdr * msg,size_t len,int flags)1178 static int l2cap_sock_recvmsg(struct socket *sock, struct msghdr *msg,
1179 size_t len, int flags)
1180 {
1181 struct sock *sk = sock->sk;
1182 struct l2cap_pinfo *pi = l2cap_pi(sk);
1183 int err;
1184
1185 lock_sock(sk);
1186
1187 if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP,
1188 &bt_sk(sk)->flags)) {
1189 if (pi->chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
1190 sk->sk_state = BT_CONNECTED;
1191 pi->chan->state = BT_CONNECTED;
1192 __l2cap_ecred_conn_rsp_defer(pi->chan);
1193 } else if (bdaddr_type_is_le(pi->chan->src_type)) {
1194 sk->sk_state = BT_CONNECTED;
1195 pi->chan->state = BT_CONNECTED;
1196 __l2cap_le_connect_rsp_defer(pi->chan);
1197 } else {
1198 sk->sk_state = BT_CONFIG;
1199 pi->chan->state = BT_CONFIG;
1200 __l2cap_connect_rsp_defer(pi->chan);
1201 }
1202
1203 err = 0;
1204 goto done;
1205 }
1206
1207 release_sock(sk);
1208
1209 if (sock->type == SOCK_STREAM)
1210 err = bt_sock_stream_recvmsg(sock, msg, len, flags);
1211 else
1212 err = bt_sock_recvmsg(sock, msg, len, flags);
1213
1214 if (pi->chan->mode != L2CAP_MODE_ERTM)
1215 return err;
1216
1217 /* Attempt to put pending rx data in the socket buffer */
1218
1219 lock_sock(sk);
1220
1221 if (!test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state))
1222 goto done;
1223
1224 if (pi->rx_busy_skb) {
1225 if (!__sock_queue_rcv_skb(sk, pi->rx_busy_skb))
1226 pi->rx_busy_skb = NULL;
1227 else
1228 goto done;
1229 }
1230
1231 /* Restore data flow when half of the receive buffer is
1232 * available. This avoids resending large numbers of
1233 * frames.
1234 */
1235 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1)
1236 l2cap_chan_busy(pi->chan, 0);
1237
1238 done:
1239 release_sock(sk);
1240 return err;
1241 }
1242
1243 /* Kill socket (only if zapped and orphan)
1244 * Must be called on unlocked socket, with l2cap channel lock.
1245 */
l2cap_sock_kill(struct sock * sk)1246 static void l2cap_sock_kill(struct sock *sk)
1247 {
1248 if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
1249 return;
1250
1251 BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state));
1252
1253 /* Kill poor orphan */
1254
1255 l2cap_chan_put(l2cap_pi(sk)->chan);
1256 sock_set_flag(sk, SOCK_DEAD);
1257 sock_put(sk);
1258 }
1259
__l2cap_wait_ack(struct sock * sk,struct l2cap_chan * chan)1260 static int __l2cap_wait_ack(struct sock *sk, struct l2cap_chan *chan)
1261 {
1262 DECLARE_WAITQUEUE(wait, current);
1263 int err = 0;
1264 int timeo = L2CAP_WAIT_ACK_POLL_PERIOD;
1265 /* Timeout to prevent infinite loop */
1266 unsigned long timeout = jiffies + L2CAP_WAIT_ACK_TIMEOUT;
1267
1268 add_wait_queue(sk_sleep(sk), &wait);
1269 set_current_state(TASK_INTERRUPTIBLE);
1270 do {
1271 BT_DBG("Waiting for %d ACKs, timeout %04d ms",
1272 chan->unacked_frames, time_after(jiffies, timeout) ? 0 :
1273 jiffies_to_msecs(timeout - jiffies));
1274
1275 if (!timeo)
1276 timeo = L2CAP_WAIT_ACK_POLL_PERIOD;
1277
1278 if (signal_pending(current)) {
1279 err = sock_intr_errno(timeo);
1280 break;
1281 }
1282
1283 release_sock(sk);
1284 timeo = schedule_timeout(timeo);
1285 lock_sock(sk);
1286 set_current_state(TASK_INTERRUPTIBLE);
1287
1288 err = sock_error(sk);
1289 if (err)
1290 break;
1291
1292 if (time_after(jiffies, timeout)) {
1293 err = -ENOLINK;
1294 break;
1295 }
1296
1297 } while (chan->unacked_frames > 0 &&
1298 chan->state == BT_CONNECTED);
1299
1300 set_current_state(TASK_RUNNING);
1301 remove_wait_queue(sk_sleep(sk), &wait);
1302 return err;
1303 }
1304
l2cap_sock_shutdown(struct socket * sock,int how)1305 static int l2cap_sock_shutdown(struct socket *sock, int how)
1306 {
1307 struct sock *sk = sock->sk;
1308 struct l2cap_chan *chan;
1309 struct l2cap_conn *conn;
1310 int err = 0;
1311
1312 BT_DBG("sock %p, sk %p, how %d", sock, sk, how);
1313
1314 /* 'how' parameter is mapped to sk_shutdown as follows:
1315 * SHUT_RD (0) --> RCV_SHUTDOWN (1)
1316 * SHUT_WR (1) --> SEND_SHUTDOWN (2)
1317 * SHUT_RDWR (2) --> SHUTDOWN_MASK (3)
1318 */
1319 how++;
1320
1321 if (!sk)
1322 return 0;
1323
1324 lock_sock(sk);
1325
1326 if ((sk->sk_shutdown & how) == how)
1327 goto shutdown_already;
1328
1329 BT_DBG("Handling sock shutdown");
1330
1331 /* prevent sk structure from being freed whilst unlocked */
1332 sock_hold(sk);
1333
1334 chan = l2cap_pi(sk)->chan;
1335 /* prevent chan structure from being freed whilst unlocked */
1336 l2cap_chan_hold(chan);
1337
1338 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
1339
1340 if (chan->mode == L2CAP_MODE_ERTM &&
1341 chan->unacked_frames > 0 &&
1342 chan->state == BT_CONNECTED) {
1343 err = __l2cap_wait_ack(sk, chan);
1344
1345 /* After waiting for ACKs, check whether shutdown
1346 * has already been actioned to close the L2CAP
1347 * link such as by l2cap_disconnection_req().
1348 */
1349 if ((sk->sk_shutdown & how) == how)
1350 goto shutdown_matched;
1351 }
1352
1353 /* Try setting the RCV_SHUTDOWN bit, return early if SEND_SHUTDOWN
1354 * is already set
1355 */
1356 if ((how & RCV_SHUTDOWN) && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
1357 sk->sk_shutdown |= RCV_SHUTDOWN;
1358 if ((sk->sk_shutdown & how) == how)
1359 goto shutdown_matched;
1360 }
1361
1362 sk->sk_shutdown |= SEND_SHUTDOWN;
1363 release_sock(sk);
1364
1365 l2cap_chan_lock(chan);
1366 conn = chan->conn;
1367 if (conn)
1368 /* prevent conn structure from being freed */
1369 l2cap_conn_get(conn);
1370 l2cap_chan_unlock(chan);
1371
1372 if (conn)
1373 /* mutex lock must be taken before l2cap_chan_lock() */
1374 mutex_lock(&conn->chan_lock);
1375
1376 l2cap_chan_lock(chan);
1377 l2cap_chan_close(chan, 0);
1378 l2cap_chan_unlock(chan);
1379
1380 if (conn) {
1381 mutex_unlock(&conn->chan_lock);
1382 l2cap_conn_put(conn);
1383 }
1384
1385 lock_sock(sk);
1386
1387 if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
1388 !(current->flags & PF_EXITING))
1389 err = bt_sock_wait_state(sk, BT_CLOSED,
1390 sk->sk_lingertime);
1391
1392 shutdown_matched:
1393 l2cap_chan_put(chan);
1394 sock_put(sk);
1395
1396 shutdown_already:
1397 if (!err && sk->sk_err)
1398 err = -sk->sk_err;
1399
1400 release_sock(sk);
1401
1402 BT_DBG("Sock shutdown complete err: %d", err);
1403
1404 return err;
1405 }
1406
l2cap_sock_release(struct socket * sock)1407 static int l2cap_sock_release(struct socket *sock)
1408 {
1409 struct sock *sk = sock->sk;
1410 int err;
1411 struct l2cap_chan *chan;
1412
1413 BT_DBG("sock %p, sk %p", sock, sk);
1414
1415 if (!sk)
1416 return 0;
1417
1418 bt_sock_unlink(&l2cap_sk_list, sk);
1419
1420 err = l2cap_sock_shutdown(sock, SHUT_RDWR);
1421 chan = l2cap_pi(sk)->chan;
1422
1423 l2cap_chan_hold(chan);
1424 l2cap_chan_lock(chan);
1425
1426 sock_orphan(sk);
1427 l2cap_sock_kill(sk);
1428
1429 l2cap_chan_unlock(chan);
1430 l2cap_chan_put(chan);
1431
1432 return err;
1433 }
1434
l2cap_sock_cleanup_listen(struct sock * parent)1435 static void l2cap_sock_cleanup_listen(struct sock *parent)
1436 {
1437 struct sock *sk;
1438
1439 BT_DBG("parent %p state %s", parent,
1440 state_to_string(parent->sk_state));
1441
1442 /* Close not yet accepted channels */
1443 while ((sk = bt_accept_dequeue(parent, NULL))) {
1444 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1445
1446 BT_DBG("child chan %p state %s", chan,
1447 state_to_string(chan->state));
1448
1449 l2cap_chan_hold(chan);
1450 l2cap_chan_lock(chan);
1451
1452 __clear_chan_timer(chan);
1453 l2cap_chan_close(chan, ECONNRESET);
1454 l2cap_sock_kill(sk);
1455
1456 l2cap_chan_unlock(chan);
1457 l2cap_chan_put(chan);
1458 }
1459 }
1460
l2cap_sock_new_connection_cb(struct l2cap_chan * chan)1461 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
1462 {
1463 struct sock *sk, *parent = chan->data;
1464
1465 lock_sock(parent);
1466
1467 /* Check for backlog size */
1468 if (sk_acceptq_is_full(parent)) {
1469 BT_DBG("backlog full %d", parent->sk_ack_backlog);
1470 release_sock(parent);
1471 return NULL;
1472 }
1473
1474 sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP,
1475 GFP_ATOMIC, 0);
1476 if (!sk) {
1477 release_sock(parent);
1478 return NULL;
1479 }
1480
1481 bt_sock_reclassify_lock(sk, BTPROTO_L2CAP);
1482
1483 l2cap_sock_init(sk, parent);
1484
1485 bt_accept_enqueue(parent, sk, false);
1486
1487 release_sock(parent);
1488
1489 return l2cap_pi(sk)->chan;
1490 }
1491
l2cap_sock_recv_cb(struct l2cap_chan * chan,struct sk_buff * skb)1492 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
1493 {
1494 struct sock *sk = chan->data;
1495 int err;
1496
1497 lock_sock(sk);
1498
1499 if (l2cap_pi(sk)->rx_busy_skb) {
1500 err = -ENOMEM;
1501 goto done;
1502 }
1503
1504 if (chan->mode != L2CAP_MODE_ERTM &&
1505 chan->mode != L2CAP_MODE_STREAMING) {
1506 /* Even if no filter is attached, we could potentially
1507 * get errors from security modules, etc.
1508 */
1509 err = sk_filter(sk, skb);
1510 if (err)
1511 goto done;
1512 }
1513
1514 err = __sock_queue_rcv_skb(sk, skb);
1515
1516 /* For ERTM, handle one skb that doesn't fit into the recv
1517 * buffer. This is important to do because the data frames
1518 * have already been acked, so the skb cannot be discarded.
1519 *
1520 * Notify the l2cap core that the buffer is full, so the
1521 * LOCAL_BUSY state is entered and no more frames are
1522 * acked and reassembled until there is buffer space
1523 * available.
1524 */
1525 if (err < 0 && chan->mode == L2CAP_MODE_ERTM) {
1526 l2cap_pi(sk)->rx_busy_skb = skb;
1527 l2cap_chan_busy(chan, 1);
1528 err = 0;
1529 }
1530
1531 done:
1532 release_sock(sk);
1533
1534 return err;
1535 }
1536
l2cap_sock_close_cb(struct l2cap_chan * chan)1537 static void l2cap_sock_close_cb(struct l2cap_chan *chan)
1538 {
1539 struct sock *sk = chan->data;
1540
1541 if (!sk)
1542 return;
1543
1544 l2cap_sock_kill(sk);
1545 }
1546
l2cap_sock_teardown_cb(struct l2cap_chan * chan,int err)1547 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err)
1548 {
1549 struct sock *sk = chan->data;
1550 struct sock *parent;
1551
1552 if (!sk)
1553 return;
1554
1555 BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
1556
1557 /* This callback can be called both for server (BT_LISTEN)
1558 * sockets as well as "normal" ones. To avoid lockdep warnings
1559 * with child socket locking (through l2cap_sock_cleanup_listen)
1560 * we need separation into separate nesting levels. The simplest
1561 * way to accomplish this is to inherit the nesting level used
1562 * for the channel.
1563 */
1564 lock_sock_nested(sk, atomic_read(&chan->nesting));
1565
1566 parent = bt_sk(sk)->parent;
1567
1568 switch (chan->state) {
1569 case BT_OPEN:
1570 case BT_BOUND:
1571 case BT_CLOSED:
1572 break;
1573 case BT_LISTEN:
1574 l2cap_sock_cleanup_listen(sk);
1575 sk->sk_state = BT_CLOSED;
1576 chan->state = BT_CLOSED;
1577
1578 break;
1579 default:
1580 sk->sk_state = BT_CLOSED;
1581 chan->state = BT_CLOSED;
1582
1583 sk->sk_err = err;
1584
1585 if (parent) {
1586 bt_accept_unlink(sk);
1587 parent->sk_data_ready(parent);
1588 } else {
1589 sk->sk_state_change(sk);
1590 }
1591
1592 break;
1593 }
1594 release_sock(sk);
1595
1596 /* Only zap after cleanup to avoid use after free race */
1597 sock_set_flag(sk, SOCK_ZAPPED);
1598
1599 }
1600
l2cap_sock_state_change_cb(struct l2cap_chan * chan,int state,int err)1601 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state,
1602 int err)
1603 {
1604 struct sock *sk = chan->data;
1605
1606 sk->sk_state = state;
1607
1608 if (err)
1609 sk->sk_err = err;
1610 }
1611
l2cap_sock_alloc_skb_cb(struct l2cap_chan * chan,unsigned long hdr_len,unsigned long len,int nb)1612 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan,
1613 unsigned long hdr_len,
1614 unsigned long len, int nb)
1615 {
1616 struct sock *sk = chan->data;
1617 struct sk_buff *skb;
1618 int err;
1619
1620 l2cap_chan_unlock(chan);
1621 skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err);
1622 l2cap_chan_lock(chan);
1623
1624 if (!skb)
1625 return ERR_PTR(err);
1626
1627 skb->priority = sk->sk_priority;
1628
1629 bt_cb(skb)->l2cap.chan = chan;
1630
1631 return skb;
1632 }
1633
l2cap_sock_ready_cb(struct l2cap_chan * chan)1634 static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
1635 {
1636 struct sock *sk = chan->data;
1637 struct sock *parent;
1638
1639 lock_sock(sk);
1640
1641 parent = bt_sk(sk)->parent;
1642
1643 BT_DBG("sk %p, parent %p", sk, parent);
1644
1645 sk->sk_state = BT_CONNECTED;
1646 sk->sk_state_change(sk);
1647
1648 if (parent)
1649 parent->sk_data_ready(parent);
1650
1651 release_sock(sk);
1652 }
1653
l2cap_sock_defer_cb(struct l2cap_chan * chan)1654 static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
1655 {
1656 struct sock *parent, *sk = chan->data;
1657
1658 lock_sock(sk);
1659
1660 parent = bt_sk(sk)->parent;
1661 if (parent)
1662 parent->sk_data_ready(parent);
1663
1664 release_sock(sk);
1665 }
1666
l2cap_sock_resume_cb(struct l2cap_chan * chan)1667 static void l2cap_sock_resume_cb(struct l2cap_chan *chan)
1668 {
1669 struct sock *sk = chan->data;
1670
1671 if (test_and_clear_bit(FLAG_PENDING_SECURITY, &chan->flags)) {
1672 sk->sk_state = BT_CONNECTED;
1673 chan->state = BT_CONNECTED;
1674 }
1675
1676 clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1677 sk->sk_state_change(sk);
1678 }
1679
l2cap_sock_set_shutdown_cb(struct l2cap_chan * chan)1680 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan)
1681 {
1682 struct sock *sk = chan->data;
1683
1684 lock_sock(sk);
1685 sk->sk_shutdown = SHUTDOWN_MASK;
1686 release_sock(sk);
1687 }
1688
l2cap_sock_get_sndtimeo_cb(struct l2cap_chan * chan)1689 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
1690 {
1691 struct sock *sk = chan->data;
1692
1693 return sk->sk_sndtimeo;
1694 }
1695
l2cap_sock_get_peer_pid_cb(struct l2cap_chan * chan)1696 static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan)
1697 {
1698 struct sock *sk = chan->data;
1699
1700 return sk->sk_peer_pid;
1701 }
1702
l2cap_sock_suspend_cb(struct l2cap_chan * chan)1703 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
1704 {
1705 struct sock *sk = chan->data;
1706
1707 set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1708 sk->sk_state_change(sk);
1709 }
1710
l2cap_sock_filter(struct l2cap_chan * chan,struct sk_buff * skb)1711 static int l2cap_sock_filter(struct l2cap_chan *chan, struct sk_buff *skb)
1712 {
1713 struct sock *sk = chan->data;
1714
1715 switch (chan->mode) {
1716 case L2CAP_MODE_ERTM:
1717 case L2CAP_MODE_STREAMING:
1718 return sk_filter(sk, skb);
1719 }
1720
1721 return 0;
1722 }
1723
1724 static const struct l2cap_ops l2cap_chan_ops = {
1725 .name = "L2CAP Socket Interface",
1726 .new_connection = l2cap_sock_new_connection_cb,
1727 .recv = l2cap_sock_recv_cb,
1728 .close = l2cap_sock_close_cb,
1729 .teardown = l2cap_sock_teardown_cb,
1730 .state_change = l2cap_sock_state_change_cb,
1731 .ready = l2cap_sock_ready_cb,
1732 .defer = l2cap_sock_defer_cb,
1733 .resume = l2cap_sock_resume_cb,
1734 .suspend = l2cap_sock_suspend_cb,
1735 .set_shutdown = l2cap_sock_set_shutdown_cb,
1736 .get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
1737 .get_peer_pid = l2cap_sock_get_peer_pid_cb,
1738 .alloc_skb = l2cap_sock_alloc_skb_cb,
1739 .filter = l2cap_sock_filter,
1740 };
1741
l2cap_sock_destruct(struct sock * sk)1742 static void l2cap_sock_destruct(struct sock *sk)
1743 {
1744 BT_DBG("sk %p", sk);
1745
1746 if (l2cap_pi(sk)->chan) {
1747 l2cap_pi(sk)->chan->data = NULL;
1748 l2cap_chan_put(l2cap_pi(sk)->chan);
1749 }
1750
1751 if (l2cap_pi(sk)->rx_busy_skb) {
1752 kfree_skb(l2cap_pi(sk)->rx_busy_skb);
1753 l2cap_pi(sk)->rx_busy_skb = NULL;
1754 }
1755
1756 skb_queue_purge(&sk->sk_receive_queue);
1757 skb_queue_purge(&sk->sk_write_queue);
1758 }
1759
l2cap_skb_msg_name(struct sk_buff * skb,void * msg_name,int * msg_namelen)1760 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name,
1761 int *msg_namelen)
1762 {
1763 DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name);
1764
1765 memset(la, 0, sizeof(struct sockaddr_l2));
1766 la->l2_family = AF_BLUETOOTH;
1767 la->l2_psm = bt_cb(skb)->l2cap.psm;
1768 bacpy(&la->l2_bdaddr, &bt_cb(skb)->l2cap.bdaddr);
1769
1770 *msg_namelen = sizeof(struct sockaddr_l2);
1771 }
1772
l2cap_sock_init(struct sock * sk,struct sock * parent)1773 static void l2cap_sock_init(struct sock *sk, struct sock *parent)
1774 {
1775 struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1776
1777 BT_DBG("sk %p", sk);
1778
1779 if (parent) {
1780 struct l2cap_chan *pchan = l2cap_pi(parent)->chan;
1781
1782 sk->sk_type = parent->sk_type;
1783 bt_sk(sk)->flags = bt_sk(parent)->flags;
1784
1785 chan->chan_type = pchan->chan_type;
1786 chan->imtu = pchan->imtu;
1787 chan->omtu = pchan->omtu;
1788 chan->conf_state = pchan->conf_state;
1789 chan->mode = pchan->mode;
1790 chan->fcs = pchan->fcs;
1791 chan->max_tx = pchan->max_tx;
1792 chan->tx_win = pchan->tx_win;
1793 chan->tx_win_max = pchan->tx_win_max;
1794 chan->sec_level = pchan->sec_level;
1795 chan->flags = pchan->flags;
1796 chan->tx_credits = pchan->tx_credits;
1797 chan->rx_credits = pchan->rx_credits;
1798
1799 if (chan->chan_type == L2CAP_CHAN_FIXED) {
1800 chan->scid = pchan->scid;
1801 chan->dcid = pchan->scid;
1802 }
1803
1804 security_sk_clone(parent, sk);
1805 } else {
1806 switch (sk->sk_type) {
1807 case SOCK_RAW:
1808 chan->chan_type = L2CAP_CHAN_RAW;
1809 break;
1810 case SOCK_DGRAM:
1811 chan->chan_type = L2CAP_CHAN_CONN_LESS;
1812 bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name;
1813 break;
1814 case SOCK_SEQPACKET:
1815 case SOCK_STREAM:
1816 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
1817 break;
1818 }
1819
1820 chan->imtu = L2CAP_DEFAULT_MTU;
1821 chan->omtu = 0;
1822 if (!disable_ertm && sk->sk_type == SOCK_STREAM) {
1823 chan->mode = L2CAP_MODE_ERTM;
1824 set_bit(CONF_STATE2_DEVICE, &chan->conf_state);
1825 } else {
1826 chan->mode = L2CAP_MODE_BASIC;
1827 }
1828
1829 l2cap_chan_set_defaults(chan);
1830 }
1831
1832 /* Default config options */
1833 chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
1834
1835 chan->data = sk;
1836 chan->ops = &l2cap_chan_ops;
1837 }
1838
1839 static struct proto l2cap_proto = {
1840 .name = "L2CAP",
1841 .owner = THIS_MODULE,
1842 .obj_size = sizeof(struct l2cap_pinfo)
1843 };
1844
l2cap_sock_alloc(struct net * net,struct socket * sock,int proto,gfp_t prio,int kern)1845 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
1846 int proto, gfp_t prio, int kern)
1847 {
1848 struct sock *sk;
1849 struct l2cap_chan *chan;
1850
1851 sk = sk_alloc(net, PF_BLUETOOTH, prio, &l2cap_proto, kern);
1852 if (!sk)
1853 return NULL;
1854
1855 sock_init_data(sock, sk);
1856 INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
1857
1858 sk->sk_destruct = l2cap_sock_destruct;
1859 sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT;
1860
1861 sock_reset_flag(sk, SOCK_ZAPPED);
1862
1863 sk->sk_protocol = proto;
1864 sk->sk_state = BT_OPEN;
1865
1866 chan = l2cap_chan_create();
1867 if (!chan) {
1868 sk_free(sk);
1869 return NULL;
1870 }
1871
1872 l2cap_chan_hold(chan);
1873
1874 l2cap_pi(sk)->chan = chan;
1875
1876 return sk;
1877 }
1878
l2cap_sock_create(struct net * net,struct socket * sock,int protocol,int kern)1879 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol,
1880 int kern)
1881 {
1882 struct sock *sk;
1883
1884 BT_DBG("sock %p", sock);
1885
1886 sock->state = SS_UNCONNECTED;
1887
1888 if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM &&
1889 sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
1890 return -ESOCKTNOSUPPORT;
1891
1892 if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1893 return -EPERM;
1894
1895 sock->ops = &l2cap_sock_ops;
1896
1897 sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern);
1898 if (!sk)
1899 return -ENOMEM;
1900
1901 l2cap_sock_init(sk, NULL);
1902 bt_sock_link(&l2cap_sk_list, sk);
1903 return 0;
1904 }
1905
1906 static const struct proto_ops l2cap_sock_ops = {
1907 .family = PF_BLUETOOTH,
1908 .owner = THIS_MODULE,
1909 .release = l2cap_sock_release,
1910 .bind = l2cap_sock_bind,
1911 .connect = l2cap_sock_connect,
1912 .listen = l2cap_sock_listen,
1913 .accept = l2cap_sock_accept,
1914 .getname = l2cap_sock_getname,
1915 .sendmsg = l2cap_sock_sendmsg,
1916 .recvmsg = l2cap_sock_recvmsg,
1917 .poll = bt_sock_poll,
1918 .ioctl = bt_sock_ioctl,
1919 .gettstamp = sock_gettstamp,
1920 .mmap = sock_no_mmap,
1921 .socketpair = sock_no_socketpair,
1922 .shutdown = l2cap_sock_shutdown,
1923 .setsockopt = l2cap_sock_setsockopt,
1924 .getsockopt = l2cap_sock_getsockopt
1925 };
1926
1927 static const struct net_proto_family l2cap_sock_family_ops = {
1928 .family = PF_BLUETOOTH,
1929 .owner = THIS_MODULE,
1930 .create = l2cap_sock_create,
1931 };
1932
l2cap_init_sockets(void)1933 int __init l2cap_init_sockets(void)
1934 {
1935 int err;
1936
1937 BUILD_BUG_ON(sizeof(struct sockaddr_l2) > sizeof(struct sockaddr));
1938
1939 err = proto_register(&l2cap_proto, 0);
1940 if (err < 0)
1941 return err;
1942
1943 err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops);
1944 if (err < 0) {
1945 BT_ERR("L2CAP socket registration failed");
1946 goto error;
1947 }
1948
1949 err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list,
1950 NULL);
1951 if (err < 0) {
1952 BT_ERR("Failed to create L2CAP proc file");
1953 bt_sock_unregister(BTPROTO_L2CAP);
1954 goto error;
1955 }
1956
1957 BT_INFO("L2CAP socket layer initialized");
1958
1959 return 0;
1960
1961 error:
1962 proto_unregister(&l2cap_proto);
1963 return err;
1964 }
1965
l2cap_cleanup_sockets(void)1966 void l2cap_cleanup_sockets(void)
1967 {
1968 bt_procfs_cleanup(&init_net, "l2cap");
1969 bt_sock_unregister(BTPROTO_L2CAP);
1970 proto_unregister(&l2cap_proto);
1971 }
1972