xref: /openbmc/linux/net/bluetooth/l2cap_sock.c (revision 62e7ca52)
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 
33 #include <net/bluetooth/bluetooth.h>
34 #include <net/bluetooth/hci_core.h>
35 #include <net/bluetooth/l2cap.h>
36 
37 #include "smp.h"
38 
39 static struct bt_sock_list l2cap_sk_list = {
40 	.lock = __RW_LOCK_UNLOCKED(l2cap_sk_list.lock)
41 };
42 
43 static const struct proto_ops l2cap_sock_ops;
44 static void l2cap_sock_init(struct sock *sk, struct sock *parent);
45 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
46 				     int proto, gfp_t prio);
47 
48 bool l2cap_is_socket(struct socket *sock)
49 {
50 	return sock && sock->ops == &l2cap_sock_ops;
51 }
52 EXPORT_SYMBOL(l2cap_is_socket);
53 
54 static int l2cap_validate_bredr_psm(u16 psm)
55 {
56 	/* PSM must be odd and lsb of upper byte must be 0 */
57 	if ((psm & 0x0101) != 0x0001)
58 		return -EINVAL;
59 
60 	/* Restrict usage of well-known PSMs */
61 	if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE))
62 		return -EACCES;
63 
64 	return 0;
65 }
66 
67 static int l2cap_validate_le_psm(u16 psm)
68 {
69 	/* Valid LE_PSM ranges are defined only until 0x00ff */
70 	if (psm > 0x00ff)
71 		return -EINVAL;
72 
73 	/* Restrict fixed, SIG assigned PSM values to CAP_NET_BIND_SERVICE */
74 	if (psm <= 0x007f && !capable(CAP_NET_BIND_SERVICE))
75 		return -EACCES;
76 
77 	return 0;
78 }
79 
80 static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
81 {
82 	struct sock *sk = sock->sk;
83 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
84 	struct sockaddr_l2 la;
85 	int len, err = 0;
86 
87 	BT_DBG("sk %p", sk);
88 
89 	if (!addr || addr->sa_family != AF_BLUETOOTH)
90 		return -EINVAL;
91 
92 	memset(&la, 0, sizeof(la));
93 	len = min_t(unsigned int, sizeof(la), alen);
94 	memcpy(&la, addr, len);
95 
96 	if (la.l2_cid && la.l2_psm)
97 		return -EINVAL;
98 
99 	if (!bdaddr_type_is_valid(la.l2_bdaddr_type))
100 		return -EINVAL;
101 
102 	if (la.l2_cid) {
103 		/* When the socket gets created it defaults to
104 		 * CHAN_CONN_ORIENTED, so we need to overwrite the
105 		 * default here.
106 		 */
107 		chan->chan_type = L2CAP_CHAN_FIXED;
108 		chan->omtu = L2CAP_DEFAULT_MTU;
109 	}
110 
111 	if (bdaddr_type_is_le(la.l2_bdaddr_type)) {
112 		/* We only allow ATT user space socket */
113 		if (la.l2_cid &&
114 		    la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
115 			return -EINVAL;
116 	}
117 
118 	lock_sock(sk);
119 
120 	if (sk->sk_state != BT_OPEN) {
121 		err = -EBADFD;
122 		goto done;
123 	}
124 
125 	if (la.l2_psm) {
126 		__u16 psm = __le16_to_cpu(la.l2_psm);
127 
128 		if (la.l2_bdaddr_type == BDADDR_BREDR)
129 			err = l2cap_validate_bredr_psm(psm);
130 		else
131 			err = l2cap_validate_le_psm(psm);
132 
133 		if (err)
134 			goto done;
135 	}
136 
137 	if (la.l2_cid)
138 		err = l2cap_add_scid(chan, __le16_to_cpu(la.l2_cid));
139 	else
140 		err = l2cap_add_psm(chan, &la.l2_bdaddr, la.l2_psm);
141 
142 	if (err < 0)
143 		goto done;
144 
145 	switch (chan->chan_type) {
146 	case L2CAP_CHAN_CONN_LESS:
147 		if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_3DSP)
148 			chan->sec_level = BT_SECURITY_SDP;
149 		break;
150 	case L2CAP_CHAN_CONN_ORIENTED:
151 		if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_SDP ||
152 		    __le16_to_cpu(la.l2_psm) == L2CAP_PSM_RFCOMM)
153 			chan->sec_level = BT_SECURITY_SDP;
154 		break;
155 	case L2CAP_CHAN_RAW:
156 		chan->sec_level = BT_SECURITY_SDP;
157 		break;
158 	}
159 
160 	bacpy(&chan->src, &la.l2_bdaddr);
161 	chan->src_type = la.l2_bdaddr_type;
162 
163 	if (chan->psm && bdaddr_type_is_le(chan->src_type))
164 		chan->mode = L2CAP_MODE_LE_FLOWCTL;
165 
166 	chan->state = BT_BOUND;
167 	sk->sk_state = BT_BOUND;
168 
169 done:
170 	release_sock(sk);
171 	return err;
172 }
173 
174 static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
175 			      int alen, int flags)
176 {
177 	struct sock *sk = sock->sk;
178 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
179 	struct sockaddr_l2 la;
180 	int len, err = 0;
181 
182 	BT_DBG("sk %p", sk);
183 
184 	if (!addr || alen < sizeof(addr->sa_family) ||
185 	    addr->sa_family != AF_BLUETOOTH)
186 		return -EINVAL;
187 
188 	memset(&la, 0, sizeof(la));
189 	len = min_t(unsigned int, sizeof(la), alen);
190 	memcpy(&la, addr, len);
191 
192 	if (la.l2_cid && la.l2_psm)
193 		return -EINVAL;
194 
195 	if (!bdaddr_type_is_valid(la.l2_bdaddr_type))
196 		return -EINVAL;
197 
198 	/* Check that the socket wasn't bound to something that
199 	 * conflicts with the address given to connect(). If chan->src
200 	 * is BDADDR_ANY it means bind() was never used, in which case
201 	 * chan->src_type and la.l2_bdaddr_type do not need to match.
202 	 */
203 	if (chan->src_type == BDADDR_BREDR && bacmp(&chan->src, BDADDR_ANY) &&
204 	    bdaddr_type_is_le(la.l2_bdaddr_type)) {
205 		/* Old user space versions will try to incorrectly bind
206 		 * the ATT socket using BDADDR_BREDR. We need to accept
207 		 * this and fix up the source address type only when
208 		 * both the source CID and destination CID indicate
209 		 * ATT. Anything else is an invalid combination.
210 		 */
211 		if (chan->scid != L2CAP_CID_ATT ||
212 		    la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
213 			return -EINVAL;
214 
215 		/* We don't have the hdev available here to make a
216 		 * better decision on random vs public, but since all
217 		 * user space versions that exhibit this issue anyway do
218 		 * not support random local addresses assuming public
219 		 * here is good enough.
220 		 */
221 		chan->src_type = BDADDR_LE_PUBLIC;
222 	}
223 
224 	if (chan->src_type != BDADDR_BREDR && la.l2_bdaddr_type == BDADDR_BREDR)
225 		return -EINVAL;
226 
227 	if (bdaddr_type_is_le(la.l2_bdaddr_type)) {
228 		/* We only allow ATT user space socket */
229 		if (la.l2_cid &&
230 		    la.l2_cid != cpu_to_le16(L2CAP_CID_ATT))
231 			return -EINVAL;
232 	}
233 
234 	if (chan->psm && bdaddr_type_is_le(chan->src_type))
235 		chan->mode = L2CAP_MODE_LE_FLOWCTL;
236 
237 	err = l2cap_chan_connect(chan, la.l2_psm, __le16_to_cpu(la.l2_cid),
238 				 &la.l2_bdaddr, la.l2_bdaddr_type);
239 	if (err)
240 		return err;
241 
242 	lock_sock(sk);
243 
244 	err = bt_sock_wait_state(sk, BT_CONNECTED,
245 				 sock_sndtimeo(sk, flags & O_NONBLOCK));
246 
247 	release_sock(sk);
248 
249 	return err;
250 }
251 
252 static int l2cap_sock_listen(struct socket *sock, int backlog)
253 {
254 	struct sock *sk = sock->sk;
255 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
256 	int err = 0;
257 
258 	BT_DBG("sk %p backlog %d", sk, backlog);
259 
260 	lock_sock(sk);
261 
262 	if (sk->sk_state != BT_BOUND) {
263 		err = -EBADFD;
264 		goto done;
265 	}
266 
267 	if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM) {
268 		err = -EINVAL;
269 		goto done;
270 	}
271 
272 	switch (chan->mode) {
273 	case L2CAP_MODE_BASIC:
274 	case L2CAP_MODE_LE_FLOWCTL:
275 		break;
276 	case L2CAP_MODE_ERTM:
277 	case L2CAP_MODE_STREAMING:
278 		if (!disable_ertm)
279 			break;
280 		/* fall through */
281 	default:
282 		err = -EOPNOTSUPP;
283 		goto done;
284 	}
285 
286 	sk->sk_max_ack_backlog = backlog;
287 	sk->sk_ack_backlog = 0;
288 
289 	chan->state = BT_LISTEN;
290 	sk->sk_state = BT_LISTEN;
291 
292 done:
293 	release_sock(sk);
294 	return err;
295 }
296 
297 static int l2cap_sock_accept(struct socket *sock, struct socket *newsock,
298 			     int flags)
299 {
300 	DECLARE_WAITQUEUE(wait, current);
301 	struct sock *sk = sock->sk, *nsk;
302 	long timeo;
303 	int err = 0;
304 
305 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
306 
307 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
308 
309 	BT_DBG("sk %p timeo %ld", sk, timeo);
310 
311 	/* Wait for an incoming connection. (wake-one). */
312 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
313 	while (1) {
314 		set_current_state(TASK_INTERRUPTIBLE);
315 
316 		if (sk->sk_state != BT_LISTEN) {
317 			err = -EBADFD;
318 			break;
319 		}
320 
321 		nsk = bt_accept_dequeue(sk, newsock);
322 		if (nsk)
323 			break;
324 
325 		if (!timeo) {
326 			err = -EAGAIN;
327 			break;
328 		}
329 
330 		if (signal_pending(current)) {
331 			err = sock_intr_errno(timeo);
332 			break;
333 		}
334 
335 		release_sock(sk);
336 		timeo = schedule_timeout(timeo);
337 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
338 	}
339 	__set_current_state(TASK_RUNNING);
340 	remove_wait_queue(sk_sleep(sk), &wait);
341 
342 	if (err)
343 		goto done;
344 
345 	newsock->state = SS_CONNECTED;
346 
347 	BT_DBG("new socket %p", nsk);
348 
349 done:
350 	release_sock(sk);
351 	return err;
352 }
353 
354 static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr,
355 			      int *len, int peer)
356 {
357 	struct sockaddr_l2 *la = (struct sockaddr_l2 *) addr;
358 	struct sock *sk = sock->sk;
359 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
360 
361 	BT_DBG("sock %p, sk %p", sock, sk);
362 
363 	if (peer && sk->sk_state != BT_CONNECTED &&
364 	    sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2 &&
365 	    sk->sk_state != BT_CONFIG)
366 		return -ENOTCONN;
367 
368 	memset(la, 0, sizeof(struct sockaddr_l2));
369 	addr->sa_family = AF_BLUETOOTH;
370 	*len = sizeof(struct sockaddr_l2);
371 
372 	la->l2_psm = chan->psm;
373 
374 	if (peer) {
375 		bacpy(&la->l2_bdaddr, &chan->dst);
376 		la->l2_cid = cpu_to_le16(chan->dcid);
377 		la->l2_bdaddr_type = chan->dst_type;
378 	} else {
379 		bacpy(&la->l2_bdaddr, &chan->src);
380 		la->l2_cid = cpu_to_le16(chan->scid);
381 		la->l2_bdaddr_type = chan->src_type;
382 	}
383 
384 	return 0;
385 }
386 
387 static int l2cap_sock_getsockopt_old(struct socket *sock, int optname,
388 				     char __user *optval, int __user *optlen)
389 {
390 	struct sock *sk = sock->sk;
391 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
392 	struct l2cap_options opts;
393 	struct l2cap_conninfo cinfo;
394 	int len, err = 0;
395 	u32 opt;
396 
397 	BT_DBG("sk %p", sk);
398 
399 	if (get_user(len, optlen))
400 		return -EFAULT;
401 
402 	lock_sock(sk);
403 
404 	switch (optname) {
405 	case L2CAP_OPTIONS:
406 		/* LE sockets should use BT_SNDMTU/BT_RCVMTU, but since
407 		 * legacy ATT code depends on getsockopt for
408 		 * L2CAP_OPTIONS we need to let this pass.
409 		 */
410 		if (bdaddr_type_is_le(chan->src_type) &&
411 		    chan->scid != L2CAP_CID_ATT) {
412 			err = -EINVAL;
413 			break;
414 		}
415 
416 		memset(&opts, 0, sizeof(opts));
417 		opts.imtu     = chan->imtu;
418 		opts.omtu     = chan->omtu;
419 		opts.flush_to = chan->flush_to;
420 		opts.mode     = chan->mode;
421 		opts.fcs      = chan->fcs;
422 		opts.max_tx   = chan->max_tx;
423 		opts.txwin_size = chan->tx_win;
424 
425 		len = min_t(unsigned int, len, sizeof(opts));
426 		if (copy_to_user(optval, (char *) &opts, len))
427 			err = -EFAULT;
428 
429 		break;
430 
431 	case L2CAP_LM:
432 		switch (chan->sec_level) {
433 		case BT_SECURITY_LOW:
434 			opt = L2CAP_LM_AUTH;
435 			break;
436 		case BT_SECURITY_MEDIUM:
437 			opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT;
438 			break;
439 		case BT_SECURITY_HIGH:
440 			opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT |
441 			      L2CAP_LM_SECURE;
442 			break;
443 		case BT_SECURITY_FIPS:
444 			opt = L2CAP_LM_AUTH | L2CAP_LM_ENCRYPT |
445 			      L2CAP_LM_SECURE | L2CAP_LM_FIPS;
446 			break;
447 		default:
448 			opt = 0;
449 			break;
450 		}
451 
452 		if (test_bit(FLAG_ROLE_SWITCH, &chan->flags))
453 			opt |= L2CAP_LM_MASTER;
454 
455 		if (test_bit(FLAG_FORCE_RELIABLE, &chan->flags))
456 			opt |= L2CAP_LM_RELIABLE;
457 
458 		if (put_user(opt, (u32 __user *) optval))
459 			err = -EFAULT;
460 
461 		break;
462 
463 	case L2CAP_CONNINFO:
464 		if (sk->sk_state != BT_CONNECTED &&
465 		    !(sk->sk_state == BT_CONNECT2 &&
466 		      test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags))) {
467 			err = -ENOTCONN;
468 			break;
469 		}
470 
471 		memset(&cinfo, 0, sizeof(cinfo));
472 		cinfo.hci_handle = chan->conn->hcon->handle;
473 		memcpy(cinfo.dev_class, chan->conn->hcon->dev_class, 3);
474 
475 		len = min_t(unsigned int, len, sizeof(cinfo));
476 		if (copy_to_user(optval, (char *) &cinfo, len))
477 			err = -EFAULT;
478 
479 		break;
480 
481 	default:
482 		err = -ENOPROTOOPT;
483 		break;
484 	}
485 
486 	release_sock(sk);
487 	return err;
488 }
489 
490 static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname,
491 				 char __user *optval, int __user *optlen)
492 {
493 	struct sock *sk = sock->sk;
494 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
495 	struct bt_security sec;
496 	struct bt_power pwr;
497 	int len, err = 0;
498 
499 	BT_DBG("sk %p", sk);
500 
501 	if (level == SOL_L2CAP)
502 		return l2cap_sock_getsockopt_old(sock, optname, optval, optlen);
503 
504 	if (level != SOL_BLUETOOTH)
505 		return -ENOPROTOOPT;
506 
507 	if (get_user(len, optlen))
508 		return -EFAULT;
509 
510 	lock_sock(sk);
511 
512 	switch (optname) {
513 	case BT_SECURITY:
514 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
515 		    chan->chan_type != L2CAP_CHAN_FIXED &&
516 		    chan->chan_type != L2CAP_CHAN_RAW) {
517 			err = -EINVAL;
518 			break;
519 		}
520 
521 		memset(&sec, 0, sizeof(sec));
522 		if (chan->conn) {
523 			sec.level = chan->conn->hcon->sec_level;
524 
525 			if (sk->sk_state == BT_CONNECTED)
526 				sec.key_size = chan->conn->hcon->enc_key_size;
527 		} else {
528 			sec.level = chan->sec_level;
529 		}
530 
531 		len = min_t(unsigned int, len, sizeof(sec));
532 		if (copy_to_user(optval, (char *) &sec, len))
533 			err = -EFAULT;
534 
535 		break;
536 
537 	case BT_DEFER_SETUP:
538 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
539 			err = -EINVAL;
540 			break;
541 		}
542 
543 		if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
544 			     (u32 __user *) optval))
545 			err = -EFAULT;
546 
547 		break;
548 
549 	case BT_FLUSHABLE:
550 		if (put_user(test_bit(FLAG_FLUSHABLE, &chan->flags),
551 			     (u32 __user *) optval))
552 			err = -EFAULT;
553 
554 		break;
555 
556 	case BT_POWER:
557 		if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM
558 		    && sk->sk_type != SOCK_RAW) {
559 			err = -EINVAL;
560 			break;
561 		}
562 
563 		pwr.force_active = test_bit(FLAG_FORCE_ACTIVE, &chan->flags);
564 
565 		len = min_t(unsigned int, len, sizeof(pwr));
566 		if (copy_to_user(optval, (char *) &pwr, len))
567 			err = -EFAULT;
568 
569 		break;
570 
571 	case BT_CHANNEL_POLICY:
572 		if (put_user(chan->chan_policy, (u32 __user *) optval))
573 			err = -EFAULT;
574 		break;
575 
576 	case BT_SNDMTU:
577 		if (!bdaddr_type_is_le(chan->src_type)) {
578 			err = -EINVAL;
579 			break;
580 		}
581 
582 		if (sk->sk_state != BT_CONNECTED) {
583 			err = -ENOTCONN;
584 			break;
585 		}
586 
587 		if (put_user(chan->omtu, (u16 __user *) optval))
588 			err = -EFAULT;
589 		break;
590 
591 	case BT_RCVMTU:
592 		if (!bdaddr_type_is_le(chan->src_type)) {
593 			err = -EINVAL;
594 			break;
595 		}
596 
597 		if (put_user(chan->imtu, (u16 __user *) optval))
598 			err = -EFAULT;
599 		break;
600 
601 	default:
602 		err = -ENOPROTOOPT;
603 		break;
604 	}
605 
606 	release_sock(sk);
607 	return err;
608 }
609 
610 static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu)
611 {
612 	switch (chan->scid) {
613 	case L2CAP_CID_ATT:
614 		if (mtu < L2CAP_LE_MIN_MTU)
615 			return false;
616 		break;
617 
618 	default:
619 		if (mtu < L2CAP_DEFAULT_MIN_MTU)
620 			return false;
621 	}
622 
623 	return true;
624 }
625 
626 static int l2cap_sock_setsockopt_old(struct socket *sock, int optname,
627 				     char __user *optval, unsigned int optlen)
628 {
629 	struct sock *sk = sock->sk;
630 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
631 	struct l2cap_options opts;
632 	int len, err = 0;
633 	u32 opt;
634 
635 	BT_DBG("sk %p", sk);
636 
637 	lock_sock(sk);
638 
639 	switch (optname) {
640 	case L2CAP_OPTIONS:
641 		if (bdaddr_type_is_le(chan->src_type)) {
642 			err = -EINVAL;
643 			break;
644 		}
645 
646 		if (sk->sk_state == BT_CONNECTED) {
647 			err = -EINVAL;
648 			break;
649 		}
650 
651 		opts.imtu     = chan->imtu;
652 		opts.omtu     = chan->omtu;
653 		opts.flush_to = chan->flush_to;
654 		opts.mode     = chan->mode;
655 		opts.fcs      = chan->fcs;
656 		opts.max_tx   = chan->max_tx;
657 		opts.txwin_size = chan->tx_win;
658 
659 		len = min_t(unsigned int, sizeof(opts), optlen);
660 		if (copy_from_user((char *) &opts, optval, len)) {
661 			err = -EFAULT;
662 			break;
663 		}
664 
665 		if (opts.txwin_size > L2CAP_DEFAULT_EXT_WINDOW) {
666 			err = -EINVAL;
667 			break;
668 		}
669 
670 		if (!l2cap_valid_mtu(chan, opts.imtu)) {
671 			err = -EINVAL;
672 			break;
673 		}
674 
675 		chan->mode = opts.mode;
676 		switch (chan->mode) {
677 		case L2CAP_MODE_LE_FLOWCTL:
678 			break;
679 		case L2CAP_MODE_BASIC:
680 			clear_bit(CONF_STATE2_DEVICE, &chan->conf_state);
681 			break;
682 		case L2CAP_MODE_ERTM:
683 		case L2CAP_MODE_STREAMING:
684 			if (!disable_ertm)
685 				break;
686 			/* fall through */
687 		default:
688 			err = -EINVAL;
689 			break;
690 		}
691 
692 		chan->imtu = opts.imtu;
693 		chan->omtu = opts.omtu;
694 		chan->fcs  = opts.fcs;
695 		chan->max_tx = opts.max_tx;
696 		chan->tx_win = opts.txwin_size;
697 		chan->flush_to = opts.flush_to;
698 		break;
699 
700 	case L2CAP_LM:
701 		if (get_user(opt, (u32 __user *) optval)) {
702 			err = -EFAULT;
703 			break;
704 		}
705 
706 		if (opt & L2CAP_LM_FIPS) {
707 			err = -EINVAL;
708 			break;
709 		}
710 
711 		if (opt & L2CAP_LM_AUTH)
712 			chan->sec_level = BT_SECURITY_LOW;
713 		if (opt & L2CAP_LM_ENCRYPT)
714 			chan->sec_level = BT_SECURITY_MEDIUM;
715 		if (opt & L2CAP_LM_SECURE)
716 			chan->sec_level = BT_SECURITY_HIGH;
717 
718 		if (opt & L2CAP_LM_MASTER)
719 			set_bit(FLAG_ROLE_SWITCH, &chan->flags);
720 		else
721 			clear_bit(FLAG_ROLE_SWITCH, &chan->flags);
722 
723 		if (opt & L2CAP_LM_RELIABLE)
724 			set_bit(FLAG_FORCE_RELIABLE, &chan->flags);
725 		else
726 			clear_bit(FLAG_FORCE_RELIABLE, &chan->flags);
727 		break;
728 
729 	default:
730 		err = -ENOPROTOOPT;
731 		break;
732 	}
733 
734 	release_sock(sk);
735 	return err;
736 }
737 
738 static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname,
739 				 char __user *optval, unsigned int optlen)
740 {
741 	struct sock *sk = sock->sk;
742 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
743 	struct bt_security sec;
744 	struct bt_power pwr;
745 	struct l2cap_conn *conn;
746 	int len, err = 0;
747 	u32 opt;
748 
749 	BT_DBG("sk %p", sk);
750 
751 	if (level == SOL_L2CAP)
752 		return l2cap_sock_setsockopt_old(sock, optname, optval, optlen);
753 
754 	if (level != SOL_BLUETOOTH)
755 		return -ENOPROTOOPT;
756 
757 	lock_sock(sk);
758 
759 	switch (optname) {
760 	case BT_SECURITY:
761 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
762 		    chan->chan_type != L2CAP_CHAN_FIXED &&
763 		    chan->chan_type != L2CAP_CHAN_RAW) {
764 			err = -EINVAL;
765 			break;
766 		}
767 
768 		sec.level = BT_SECURITY_LOW;
769 
770 		len = min_t(unsigned int, sizeof(sec), optlen);
771 		if (copy_from_user((char *) &sec, optval, len)) {
772 			err = -EFAULT;
773 			break;
774 		}
775 
776 		if (sec.level < BT_SECURITY_LOW ||
777 		    sec.level > BT_SECURITY_HIGH) {
778 			err = -EINVAL;
779 			break;
780 		}
781 
782 		chan->sec_level = sec.level;
783 
784 		if (!chan->conn)
785 			break;
786 
787 		conn = chan->conn;
788 
789 		/*change security for LE channels */
790 		if (chan->scid == L2CAP_CID_ATT) {
791 			if (smp_conn_security(conn->hcon, sec.level))
792 				break;
793 			sk->sk_state = BT_CONFIG;
794 			chan->state = BT_CONFIG;
795 
796 		/* or for ACL link */
797 		} else if ((sk->sk_state == BT_CONNECT2 &&
798 			    test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags)) ||
799 			   sk->sk_state == BT_CONNECTED) {
800 			if (!l2cap_chan_check_security(chan, true))
801 				set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
802 			else
803 				sk->sk_state_change(sk);
804 		} else {
805 			err = -EINVAL;
806 		}
807 		break;
808 
809 	case BT_DEFER_SETUP:
810 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
811 			err = -EINVAL;
812 			break;
813 		}
814 
815 		if (get_user(opt, (u32 __user *) optval)) {
816 			err = -EFAULT;
817 			break;
818 		}
819 
820 		if (opt) {
821 			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
822 			set_bit(FLAG_DEFER_SETUP, &chan->flags);
823 		} else {
824 			clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
825 			clear_bit(FLAG_DEFER_SETUP, &chan->flags);
826 		}
827 		break;
828 
829 	case BT_FLUSHABLE:
830 		if (get_user(opt, (u32 __user *) optval)) {
831 			err = -EFAULT;
832 			break;
833 		}
834 
835 		if (opt > BT_FLUSHABLE_ON) {
836 			err = -EINVAL;
837 			break;
838 		}
839 
840 		if (opt == BT_FLUSHABLE_OFF) {
841 			conn = chan->conn;
842 			/* proceed further only when we have l2cap_conn and
843 			   No Flush support in the LM */
844 			if (!conn || !lmp_no_flush_capable(conn->hcon->hdev)) {
845 				err = -EINVAL;
846 				break;
847 			}
848 		}
849 
850 		if (opt)
851 			set_bit(FLAG_FLUSHABLE, &chan->flags);
852 		else
853 			clear_bit(FLAG_FLUSHABLE, &chan->flags);
854 		break;
855 
856 	case BT_POWER:
857 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED &&
858 		    chan->chan_type != L2CAP_CHAN_RAW) {
859 			err = -EINVAL;
860 			break;
861 		}
862 
863 		pwr.force_active = BT_POWER_FORCE_ACTIVE_ON;
864 
865 		len = min_t(unsigned int, sizeof(pwr), optlen);
866 		if (copy_from_user((char *) &pwr, optval, len)) {
867 			err = -EFAULT;
868 			break;
869 		}
870 
871 		if (pwr.force_active)
872 			set_bit(FLAG_FORCE_ACTIVE, &chan->flags);
873 		else
874 			clear_bit(FLAG_FORCE_ACTIVE, &chan->flags);
875 		break;
876 
877 	case BT_CHANNEL_POLICY:
878 		if (get_user(opt, (u32 __user *) optval)) {
879 			err = -EFAULT;
880 			break;
881 		}
882 
883 		if (opt > BT_CHANNEL_POLICY_AMP_PREFERRED) {
884 			err = -EINVAL;
885 			break;
886 		}
887 
888 		if (chan->mode != L2CAP_MODE_ERTM &&
889 		    chan->mode != L2CAP_MODE_STREAMING) {
890 			err = -EOPNOTSUPP;
891 			break;
892 		}
893 
894 		chan->chan_policy = (u8) opt;
895 
896 		if (sk->sk_state == BT_CONNECTED &&
897 		    chan->move_role == L2CAP_MOVE_ROLE_NONE)
898 			l2cap_move_start(chan);
899 
900 		break;
901 
902 	case BT_SNDMTU:
903 		if (!bdaddr_type_is_le(chan->src_type)) {
904 			err = -EINVAL;
905 			break;
906 		}
907 
908 		/* Setting is not supported as it's the remote side that
909 		 * decides this.
910 		 */
911 		err = -EPERM;
912 		break;
913 
914 	case BT_RCVMTU:
915 		if (!bdaddr_type_is_le(chan->src_type)) {
916 			err = -EINVAL;
917 			break;
918 		}
919 
920 		if (sk->sk_state == BT_CONNECTED) {
921 			err = -EISCONN;
922 			break;
923 		}
924 
925 		if (get_user(opt, (u32 __user *) optval)) {
926 			err = -EFAULT;
927 			break;
928 		}
929 
930 		chan->imtu = opt;
931 		break;
932 
933 	default:
934 		err = -ENOPROTOOPT;
935 		break;
936 	}
937 
938 	release_sock(sk);
939 	return err;
940 }
941 
942 static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
943 			      struct msghdr *msg, size_t len)
944 {
945 	struct sock *sk = sock->sk;
946 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
947 	int err;
948 
949 	BT_DBG("sock %p, sk %p", sock, sk);
950 
951 	err = sock_error(sk);
952 	if (err)
953 		return err;
954 
955 	if (msg->msg_flags & MSG_OOB)
956 		return -EOPNOTSUPP;
957 
958 	if (sk->sk_state != BT_CONNECTED)
959 		return -ENOTCONN;
960 
961 	lock_sock(sk);
962 	err = bt_sock_wait_ready(sk, msg->msg_flags);
963 	release_sock(sk);
964 	if (err)
965 		return err;
966 
967 	l2cap_chan_lock(chan);
968 	err = l2cap_chan_send(chan, msg, len);
969 	l2cap_chan_unlock(chan);
970 
971 	return err;
972 }
973 
974 static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
975 			      struct msghdr *msg, size_t len, int flags)
976 {
977 	struct sock *sk = sock->sk;
978 	struct l2cap_pinfo *pi = l2cap_pi(sk);
979 	int err;
980 
981 	lock_sock(sk);
982 
983 	if (sk->sk_state == BT_CONNECT2 && test_bit(BT_SK_DEFER_SETUP,
984 						    &bt_sk(sk)->flags)) {
985 		if (bdaddr_type_is_le(pi->chan->src_type)) {
986 			sk->sk_state = BT_CONNECTED;
987 			pi->chan->state = BT_CONNECTED;
988 			__l2cap_le_connect_rsp_defer(pi->chan);
989 		} else {
990 			sk->sk_state = BT_CONFIG;
991 			pi->chan->state = BT_CONFIG;
992 			__l2cap_connect_rsp_defer(pi->chan);
993 		}
994 
995 		err = 0;
996 		goto done;
997 	}
998 
999 	release_sock(sk);
1000 
1001 	if (sock->type == SOCK_STREAM)
1002 		err = bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
1003 	else
1004 		err = bt_sock_recvmsg(iocb, sock, msg, len, flags);
1005 
1006 	if (pi->chan->mode != L2CAP_MODE_ERTM)
1007 		return err;
1008 
1009 	/* Attempt to put pending rx data in the socket buffer */
1010 
1011 	lock_sock(sk);
1012 
1013 	if (!test_bit(CONN_LOCAL_BUSY, &pi->chan->conn_state))
1014 		goto done;
1015 
1016 	if (pi->rx_busy_skb) {
1017 		if (!sock_queue_rcv_skb(sk, pi->rx_busy_skb))
1018 			pi->rx_busy_skb = NULL;
1019 		else
1020 			goto done;
1021 	}
1022 
1023 	/* Restore data flow when half of the receive buffer is
1024 	 * available.  This avoids resending large numbers of
1025 	 * frames.
1026 	 */
1027 	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf >> 1)
1028 		l2cap_chan_busy(pi->chan, 0);
1029 
1030 done:
1031 	release_sock(sk);
1032 	return err;
1033 }
1034 
1035 /* Kill socket (only if zapped and orphan)
1036  * Must be called on unlocked socket.
1037  */
1038 static void l2cap_sock_kill(struct sock *sk)
1039 {
1040 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
1041 		return;
1042 
1043 	BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state));
1044 
1045 	/* Kill poor orphan */
1046 
1047 	l2cap_chan_put(l2cap_pi(sk)->chan);
1048 	sock_set_flag(sk, SOCK_DEAD);
1049 	sock_put(sk);
1050 }
1051 
1052 static int __l2cap_wait_ack(struct sock *sk)
1053 {
1054 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1055 	DECLARE_WAITQUEUE(wait, current);
1056 	int err = 0;
1057 	int timeo = HZ/5;
1058 
1059 	add_wait_queue(sk_sleep(sk), &wait);
1060 	set_current_state(TASK_INTERRUPTIBLE);
1061 	while (chan->unacked_frames > 0 && chan->conn) {
1062 		if (!timeo)
1063 			timeo = HZ/5;
1064 
1065 		if (signal_pending(current)) {
1066 			err = sock_intr_errno(timeo);
1067 			break;
1068 		}
1069 
1070 		release_sock(sk);
1071 		timeo = schedule_timeout(timeo);
1072 		lock_sock(sk);
1073 		set_current_state(TASK_INTERRUPTIBLE);
1074 
1075 		err = sock_error(sk);
1076 		if (err)
1077 			break;
1078 	}
1079 	set_current_state(TASK_RUNNING);
1080 	remove_wait_queue(sk_sleep(sk), &wait);
1081 	return err;
1082 }
1083 
1084 static int l2cap_sock_shutdown(struct socket *sock, int how)
1085 {
1086 	struct sock *sk = sock->sk;
1087 	struct l2cap_chan *chan;
1088 	struct l2cap_conn *conn;
1089 	int err = 0;
1090 
1091 	BT_DBG("sock %p, sk %p", sock, sk);
1092 
1093 	if (!sk)
1094 		return 0;
1095 
1096 	chan = l2cap_pi(sk)->chan;
1097 	conn = chan->conn;
1098 
1099 	if (conn)
1100 		mutex_lock(&conn->chan_lock);
1101 
1102 	l2cap_chan_lock(chan);
1103 	lock_sock(sk);
1104 
1105 	if (!sk->sk_shutdown) {
1106 		if (chan->mode == L2CAP_MODE_ERTM)
1107 			err = __l2cap_wait_ack(sk);
1108 
1109 		sk->sk_shutdown = SHUTDOWN_MASK;
1110 
1111 		release_sock(sk);
1112 		l2cap_chan_close(chan, 0);
1113 		lock_sock(sk);
1114 
1115 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
1116 		    !(current->flags & PF_EXITING))
1117 			err = bt_sock_wait_state(sk, BT_CLOSED,
1118 						 sk->sk_lingertime);
1119 	}
1120 
1121 	if (!err && sk->sk_err)
1122 		err = -sk->sk_err;
1123 
1124 	release_sock(sk);
1125 	l2cap_chan_unlock(chan);
1126 
1127 	if (conn)
1128 		mutex_unlock(&conn->chan_lock);
1129 
1130 	return err;
1131 }
1132 
1133 static int l2cap_sock_release(struct socket *sock)
1134 {
1135 	struct sock *sk = sock->sk;
1136 	int err;
1137 
1138 	BT_DBG("sock %p, sk %p", sock, sk);
1139 
1140 	if (!sk)
1141 		return 0;
1142 
1143 	bt_sock_unlink(&l2cap_sk_list, sk);
1144 
1145 	err = l2cap_sock_shutdown(sock, 2);
1146 
1147 	sock_orphan(sk);
1148 	l2cap_sock_kill(sk);
1149 	return err;
1150 }
1151 
1152 static void l2cap_sock_cleanup_listen(struct sock *parent)
1153 {
1154 	struct sock *sk;
1155 
1156 	BT_DBG("parent %p", parent);
1157 
1158 	/* Close not yet accepted channels */
1159 	while ((sk = bt_accept_dequeue(parent, NULL))) {
1160 		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1161 
1162 		l2cap_chan_lock(chan);
1163 		__clear_chan_timer(chan);
1164 		l2cap_chan_close(chan, ECONNRESET);
1165 		l2cap_chan_unlock(chan);
1166 
1167 		l2cap_sock_kill(sk);
1168 	}
1169 }
1170 
1171 static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
1172 {
1173 	struct sock *sk, *parent = chan->data;
1174 
1175 	lock_sock(parent);
1176 
1177 	/* Check for backlog size */
1178 	if (sk_acceptq_is_full(parent)) {
1179 		BT_DBG("backlog full %d", parent->sk_ack_backlog);
1180 		release_sock(parent);
1181 		return NULL;
1182 	}
1183 
1184 	sk = l2cap_sock_alloc(sock_net(parent), NULL, BTPROTO_L2CAP,
1185 			      GFP_ATOMIC);
1186 	if (!sk) {
1187 		release_sock(parent);
1188 		return NULL;
1189         }
1190 
1191 	bt_sock_reclassify_lock(sk, BTPROTO_L2CAP);
1192 
1193 	l2cap_sock_init(sk, parent);
1194 
1195 	bt_accept_enqueue(parent, sk);
1196 
1197 	release_sock(parent);
1198 
1199 	return l2cap_pi(sk)->chan;
1200 }
1201 
1202 static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
1203 {
1204 	struct sock *sk = chan->data;
1205 	int err;
1206 
1207 	lock_sock(sk);
1208 
1209 	if (l2cap_pi(sk)->rx_busy_skb) {
1210 		err = -ENOMEM;
1211 		goto done;
1212 	}
1213 
1214 	err = sock_queue_rcv_skb(sk, skb);
1215 
1216 	/* For ERTM, handle one skb that doesn't fit into the recv
1217 	 * buffer.  This is important to do because the data frames
1218 	 * have already been acked, so the skb cannot be discarded.
1219 	 *
1220 	 * Notify the l2cap core that the buffer is full, so the
1221 	 * LOCAL_BUSY state is entered and no more frames are
1222 	 * acked and reassembled until there is buffer space
1223 	 * available.
1224 	 */
1225 	if (err < 0 && chan->mode == L2CAP_MODE_ERTM) {
1226 		l2cap_pi(sk)->rx_busy_skb = skb;
1227 		l2cap_chan_busy(chan, 1);
1228 		err = 0;
1229 	}
1230 
1231 done:
1232 	release_sock(sk);
1233 
1234 	return err;
1235 }
1236 
1237 static void l2cap_sock_close_cb(struct l2cap_chan *chan)
1238 {
1239 	struct sock *sk = chan->data;
1240 
1241 	l2cap_sock_kill(sk);
1242 }
1243 
1244 static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err)
1245 {
1246 	struct sock *sk = chan->data;
1247 	struct sock *parent;
1248 
1249 	lock_sock(sk);
1250 
1251 	parent = bt_sk(sk)->parent;
1252 
1253 	sock_set_flag(sk, SOCK_ZAPPED);
1254 
1255 	switch (chan->state) {
1256 	case BT_OPEN:
1257 	case BT_BOUND:
1258 	case BT_CLOSED:
1259 		break;
1260 	case BT_LISTEN:
1261 		l2cap_sock_cleanup_listen(sk);
1262 		sk->sk_state = BT_CLOSED;
1263 		chan->state = BT_CLOSED;
1264 
1265 		break;
1266 	default:
1267 		sk->sk_state = BT_CLOSED;
1268 		chan->state = BT_CLOSED;
1269 
1270 		sk->sk_err = err;
1271 
1272 		if (parent) {
1273 			bt_accept_unlink(sk);
1274 			parent->sk_data_ready(parent);
1275 		} else {
1276 			sk->sk_state_change(sk);
1277 		}
1278 
1279 		break;
1280 	}
1281 
1282 	release_sock(sk);
1283 }
1284 
1285 static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state,
1286 				       int err)
1287 {
1288 	struct sock *sk = chan->data;
1289 
1290 	sk->sk_state = state;
1291 
1292 	if (err)
1293 		sk->sk_err = err;
1294 }
1295 
1296 static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan,
1297 					       unsigned long hdr_len,
1298 					       unsigned long len, int nb)
1299 {
1300 	struct sock *sk = chan->data;
1301 	struct sk_buff *skb;
1302 	int err;
1303 
1304 	l2cap_chan_unlock(chan);
1305 	skb = bt_skb_send_alloc(sk, hdr_len + len, nb, &err);
1306 	l2cap_chan_lock(chan);
1307 
1308 	if (!skb)
1309 		return ERR_PTR(err);
1310 
1311 	skb->priority = sk->sk_priority;
1312 
1313 	bt_cb(skb)->chan = chan;
1314 
1315 	return skb;
1316 }
1317 
1318 static int l2cap_sock_memcpy_fromiovec_cb(struct l2cap_chan *chan,
1319 					  unsigned char *kdata,
1320 					  struct iovec *iov, int len)
1321 {
1322 	return memcpy_fromiovec(kdata, iov, len);
1323 }
1324 
1325 static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
1326 {
1327 	struct sock *sk = chan->data;
1328 	struct sock *parent;
1329 
1330 	lock_sock(sk);
1331 
1332 	parent = bt_sk(sk)->parent;
1333 
1334 	BT_DBG("sk %p, parent %p", sk, parent);
1335 
1336 	sk->sk_state = BT_CONNECTED;
1337 	sk->sk_state_change(sk);
1338 
1339 	if (parent)
1340 		parent->sk_data_ready(parent);
1341 
1342 	release_sock(sk);
1343 }
1344 
1345 static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
1346 {
1347 	struct sock *parent, *sk = chan->data;
1348 
1349 	lock_sock(sk);
1350 
1351 	parent = bt_sk(sk)->parent;
1352 	if (parent)
1353 		parent->sk_data_ready(parent);
1354 
1355 	release_sock(sk);
1356 }
1357 
1358 static void l2cap_sock_resume_cb(struct l2cap_chan *chan)
1359 {
1360 	struct sock *sk = chan->data;
1361 
1362 	clear_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1363 	sk->sk_state_change(sk);
1364 }
1365 
1366 static void l2cap_sock_set_shutdown_cb(struct l2cap_chan *chan)
1367 {
1368 	struct sock *sk = chan->data;
1369 
1370 	lock_sock(sk);
1371 	sk->sk_shutdown = SHUTDOWN_MASK;
1372 	release_sock(sk);
1373 }
1374 
1375 static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
1376 {
1377 	struct sock *sk = chan->data;
1378 
1379 	return sk->sk_sndtimeo;
1380 }
1381 
1382 static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
1383 {
1384 	struct sock *sk = chan->data;
1385 
1386 	set_bit(BT_SK_SUSPEND, &bt_sk(sk)->flags);
1387 	sk->sk_state_change(sk);
1388 }
1389 
1390 static const struct l2cap_ops l2cap_chan_ops = {
1391 	.name			= "L2CAP Socket Interface",
1392 	.new_connection		= l2cap_sock_new_connection_cb,
1393 	.recv			= l2cap_sock_recv_cb,
1394 	.close			= l2cap_sock_close_cb,
1395 	.teardown		= l2cap_sock_teardown_cb,
1396 	.state_change		= l2cap_sock_state_change_cb,
1397 	.ready			= l2cap_sock_ready_cb,
1398 	.defer			= l2cap_sock_defer_cb,
1399 	.resume			= l2cap_sock_resume_cb,
1400 	.suspend		= l2cap_sock_suspend_cb,
1401 	.set_shutdown		= l2cap_sock_set_shutdown_cb,
1402 	.get_sndtimeo		= l2cap_sock_get_sndtimeo_cb,
1403 	.alloc_skb		= l2cap_sock_alloc_skb_cb,
1404 	.memcpy_fromiovec	= l2cap_sock_memcpy_fromiovec_cb,
1405 };
1406 
1407 static void l2cap_sock_destruct(struct sock *sk)
1408 {
1409 	BT_DBG("sk %p", sk);
1410 
1411 	if (l2cap_pi(sk)->chan)
1412 		l2cap_chan_put(l2cap_pi(sk)->chan);
1413 
1414 	if (l2cap_pi(sk)->rx_busy_skb) {
1415 		kfree_skb(l2cap_pi(sk)->rx_busy_skb);
1416 		l2cap_pi(sk)->rx_busy_skb = NULL;
1417 	}
1418 
1419 	skb_queue_purge(&sk->sk_receive_queue);
1420 	skb_queue_purge(&sk->sk_write_queue);
1421 }
1422 
1423 static void l2cap_skb_msg_name(struct sk_buff *skb, void *msg_name,
1424 			       int *msg_namelen)
1425 {
1426 	DECLARE_SOCKADDR(struct sockaddr_l2 *, la, msg_name);
1427 
1428 	memset(la, 0, sizeof(struct sockaddr_l2));
1429 	la->l2_family = AF_BLUETOOTH;
1430 	la->l2_psm = bt_cb(skb)->psm;
1431 	bacpy(&la->l2_bdaddr, &bt_cb(skb)->bdaddr);
1432 
1433 	*msg_namelen = sizeof(struct sockaddr_l2);
1434 }
1435 
1436 static void l2cap_sock_init(struct sock *sk, struct sock *parent)
1437 {
1438 	struct l2cap_chan *chan = l2cap_pi(sk)->chan;
1439 
1440 	BT_DBG("sk %p", sk);
1441 
1442 	if (parent) {
1443 		struct l2cap_chan *pchan = l2cap_pi(parent)->chan;
1444 
1445 		sk->sk_type = parent->sk_type;
1446 		bt_sk(sk)->flags = bt_sk(parent)->flags;
1447 
1448 		chan->chan_type = pchan->chan_type;
1449 		chan->imtu = pchan->imtu;
1450 		chan->omtu = pchan->omtu;
1451 		chan->conf_state = pchan->conf_state;
1452 		chan->mode = pchan->mode;
1453 		chan->fcs  = pchan->fcs;
1454 		chan->max_tx = pchan->max_tx;
1455 		chan->tx_win = pchan->tx_win;
1456 		chan->tx_win_max = pchan->tx_win_max;
1457 		chan->sec_level = pchan->sec_level;
1458 		chan->flags = pchan->flags;
1459 		chan->tx_credits = pchan->tx_credits;
1460 		chan->rx_credits = pchan->rx_credits;
1461 
1462 		if (chan->chan_type == L2CAP_CHAN_FIXED) {
1463 			chan->scid = pchan->scid;
1464 			chan->dcid = pchan->scid;
1465 		}
1466 
1467 		security_sk_clone(parent, sk);
1468 	} else {
1469 		switch (sk->sk_type) {
1470 		case SOCK_RAW:
1471 			chan->chan_type = L2CAP_CHAN_RAW;
1472 			break;
1473 		case SOCK_DGRAM:
1474 			chan->chan_type = L2CAP_CHAN_CONN_LESS;
1475 			bt_sk(sk)->skb_msg_name = l2cap_skb_msg_name;
1476 			break;
1477 		case SOCK_SEQPACKET:
1478 		case SOCK_STREAM:
1479 			chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
1480 			break;
1481 		}
1482 
1483 		chan->imtu = L2CAP_DEFAULT_MTU;
1484 		chan->omtu = 0;
1485 		if (!disable_ertm && sk->sk_type == SOCK_STREAM) {
1486 			chan->mode = L2CAP_MODE_ERTM;
1487 			set_bit(CONF_STATE2_DEVICE, &chan->conf_state);
1488 		} else {
1489 			chan->mode = L2CAP_MODE_BASIC;
1490 		}
1491 
1492 		l2cap_chan_set_defaults(chan);
1493 	}
1494 
1495 	/* Default config options */
1496 	chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
1497 
1498 	chan->data = sk;
1499 	chan->ops = &l2cap_chan_ops;
1500 }
1501 
1502 static struct proto l2cap_proto = {
1503 	.name		= "L2CAP",
1504 	.owner		= THIS_MODULE,
1505 	.obj_size	= sizeof(struct l2cap_pinfo)
1506 };
1507 
1508 static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock,
1509 				     int proto, gfp_t prio)
1510 {
1511 	struct sock *sk;
1512 	struct l2cap_chan *chan;
1513 
1514 	sk = sk_alloc(net, PF_BLUETOOTH, prio, &l2cap_proto);
1515 	if (!sk)
1516 		return NULL;
1517 
1518 	sock_init_data(sock, sk);
1519 	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
1520 
1521 	sk->sk_destruct = l2cap_sock_destruct;
1522 	sk->sk_sndtimeo = L2CAP_CONN_TIMEOUT;
1523 
1524 	sock_reset_flag(sk, SOCK_ZAPPED);
1525 
1526 	sk->sk_protocol = proto;
1527 	sk->sk_state = BT_OPEN;
1528 
1529 	chan = l2cap_chan_create();
1530 	if (!chan) {
1531 		sk_free(sk);
1532 		return NULL;
1533 	}
1534 
1535 	l2cap_chan_hold(chan);
1536 
1537 	l2cap_pi(sk)->chan = chan;
1538 
1539 	return sk;
1540 }
1541 
1542 static int l2cap_sock_create(struct net *net, struct socket *sock, int protocol,
1543 			     int kern)
1544 {
1545 	struct sock *sk;
1546 
1547 	BT_DBG("sock %p", sock);
1548 
1549 	sock->state = SS_UNCONNECTED;
1550 
1551 	if (sock->type != SOCK_SEQPACKET && sock->type != SOCK_STREAM &&
1552 	    sock->type != SOCK_DGRAM && sock->type != SOCK_RAW)
1553 		return -ESOCKTNOSUPPORT;
1554 
1555 	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1556 		return -EPERM;
1557 
1558 	sock->ops = &l2cap_sock_ops;
1559 
1560 	sk = l2cap_sock_alloc(net, sock, protocol, GFP_ATOMIC);
1561 	if (!sk)
1562 		return -ENOMEM;
1563 
1564 	l2cap_sock_init(sk, NULL);
1565 	bt_sock_link(&l2cap_sk_list, sk);
1566 	return 0;
1567 }
1568 
1569 static const struct proto_ops l2cap_sock_ops = {
1570 	.family		= PF_BLUETOOTH,
1571 	.owner		= THIS_MODULE,
1572 	.release	= l2cap_sock_release,
1573 	.bind		= l2cap_sock_bind,
1574 	.connect	= l2cap_sock_connect,
1575 	.listen		= l2cap_sock_listen,
1576 	.accept		= l2cap_sock_accept,
1577 	.getname	= l2cap_sock_getname,
1578 	.sendmsg	= l2cap_sock_sendmsg,
1579 	.recvmsg	= l2cap_sock_recvmsg,
1580 	.poll		= bt_sock_poll,
1581 	.ioctl		= bt_sock_ioctl,
1582 	.mmap		= sock_no_mmap,
1583 	.socketpair	= sock_no_socketpair,
1584 	.shutdown	= l2cap_sock_shutdown,
1585 	.setsockopt	= l2cap_sock_setsockopt,
1586 	.getsockopt	= l2cap_sock_getsockopt
1587 };
1588 
1589 static const struct net_proto_family l2cap_sock_family_ops = {
1590 	.family	= PF_BLUETOOTH,
1591 	.owner	= THIS_MODULE,
1592 	.create	= l2cap_sock_create,
1593 };
1594 
1595 int __init l2cap_init_sockets(void)
1596 {
1597 	int err;
1598 
1599 	err = proto_register(&l2cap_proto, 0);
1600 	if (err < 0)
1601 		return err;
1602 
1603 	err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops);
1604 	if (err < 0) {
1605 		BT_ERR("L2CAP socket registration failed");
1606 		goto error;
1607 	}
1608 
1609 	err = bt_procfs_init(&init_net, "l2cap", &l2cap_sk_list,
1610 			     NULL);
1611 	if (err < 0) {
1612 		BT_ERR("Failed to create L2CAP proc file");
1613 		bt_sock_unregister(BTPROTO_L2CAP);
1614 		goto error;
1615 	}
1616 
1617 	BT_INFO("L2CAP socket layer initialized");
1618 
1619 	return 0;
1620 
1621 error:
1622 	proto_unregister(&l2cap_proto);
1623 	return err;
1624 }
1625 
1626 void l2cap_cleanup_sockets(void)
1627 {
1628 	bt_procfs_cleanup(&init_net, "l2cap");
1629 	bt_sock_unregister(BTPROTO_L2CAP);
1630 	proto_unregister(&l2cap_proto);
1631 }
1632