xref: /linux/net/bluetooth/rfcomm/sock.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 /*
2    RFCOMM implementation for Linux Bluetooth stack (BlueZ).
3    Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
4    Copyright (C) 2002 Marcel Holtmann <marcel@holtmann.org>
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License version 2 as
8    published by the Free Software Foundation;
9 
10    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
11    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
12    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
13    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
14    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
15    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 
19    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
20    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
21    SOFTWARE IS DISCLAIMED.
22 */
23 
24 /*
25  * RFCOMM sockets.
26  */
27 #include <linux/compat.h>
28 #include <linux/export.h>
29 #include <linux/debugfs.h>
30 #include <linux/sched/signal.h>
31 
32 #include <net/bluetooth/bluetooth.h>
33 #include <net/bluetooth/hci_core.h>
34 #include <net/bluetooth/l2cap.h>
35 #include <net/bluetooth/rfcomm.h>
36 
37 static const struct proto_ops rfcomm_sock_ops;
38 
39 static struct bt_sock_list rfcomm_sk_list = {
40 	.lock = __RW_LOCK_UNLOCKED(rfcomm_sk_list.lock)
41 };
42 
43 static void rfcomm_sock_close(struct sock *sk);
44 static void rfcomm_sock_kill(struct sock *sk);
45 
46 /* ---- DLC callbacks ----
47  *
48  * called under rfcomm_dlc_lock()
49  */
50 static void rfcomm_sk_data_ready(struct rfcomm_dlc *d, struct sk_buff *skb)
51 {
52 	struct sock *sk = d->owner;
53 	if (!sk)
54 		return;
55 
56 	atomic_add(skb->len, &sk->sk_rmem_alloc);
57 	skb_queue_tail(&sk->sk_receive_queue, skb);
58 	sk->sk_data_ready(sk);
59 
60 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
61 		rfcomm_dlc_throttle(d);
62 }
63 
64 static void rfcomm_sk_state_change(struct rfcomm_dlc *d, int err)
65 {
66 	struct sock *sk = d->owner, *parent;
67 
68 	if (!sk)
69 		return;
70 
71 	BT_DBG("dlc %p state %ld err %d", d, d->state, err);
72 
73 	lock_sock(sk);
74 
75 	if (err)
76 		sk->sk_err = err;
77 
78 	sk->sk_state = d->state;
79 
80 	parent = bt_sk(sk)->parent;
81 	if (parent) {
82 		if (d->state == BT_CLOSED) {
83 			sock_set_flag(sk, SOCK_ZAPPED);
84 			bt_accept_unlink(sk);
85 		}
86 		parent->sk_data_ready(parent);
87 	} else {
88 		if (d->state == BT_CONNECTED)
89 			rfcomm_session_getaddr(d->session,
90 					       &rfcomm_pi(sk)->src, NULL);
91 		sk->sk_state_change(sk);
92 	}
93 
94 	release_sock(sk);
95 
96 	if (parent && sock_flag(sk, SOCK_ZAPPED)) {
97 		/* We have to drop DLC lock here, otherwise
98 		 * rfcomm_sock_destruct() will dead lock. */
99 		rfcomm_dlc_unlock(d);
100 		rfcomm_sock_kill(sk);
101 		rfcomm_dlc_lock(d);
102 	}
103 }
104 
105 /* ---- Socket functions ---- */
106 static struct sock *__rfcomm_get_listen_sock_by_addr(u8 channel, bdaddr_t *src)
107 {
108 	struct sock *sk = NULL;
109 
110 	sk_for_each(sk, &rfcomm_sk_list.head) {
111 		if (rfcomm_pi(sk)->channel != channel)
112 			continue;
113 
114 		if (bacmp(&rfcomm_pi(sk)->src, src))
115 			continue;
116 
117 		if (sk->sk_state == BT_BOUND || sk->sk_state == BT_LISTEN)
118 			break;
119 	}
120 
121 	return sk ? sk : NULL;
122 }
123 
124 /* Find socket with channel and source bdaddr.
125  * Returns closest match.
126  */
127 static struct sock *rfcomm_get_sock_by_channel(int state, u8 channel, bdaddr_t *src)
128 {
129 	struct sock *sk = NULL, *sk1 = NULL;
130 
131 	read_lock(&rfcomm_sk_list.lock);
132 
133 	sk_for_each(sk, &rfcomm_sk_list.head) {
134 		if (state && sk->sk_state != state)
135 			continue;
136 
137 		if (rfcomm_pi(sk)->channel == channel) {
138 			/* Exact match. */
139 			if (!bacmp(&rfcomm_pi(sk)->src, src))
140 				break;
141 
142 			/* Closest match */
143 			if (!bacmp(&rfcomm_pi(sk)->src, BDADDR_ANY))
144 				sk1 = sk;
145 		}
146 	}
147 
148 	read_unlock(&rfcomm_sk_list.lock);
149 
150 	return sk ? sk : sk1;
151 }
152 
153 static void rfcomm_sock_destruct(struct sock *sk)
154 {
155 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
156 
157 	BT_DBG("sk %p dlc %p", sk, d);
158 
159 	skb_queue_purge(&sk->sk_receive_queue);
160 	skb_queue_purge(&sk->sk_write_queue);
161 
162 	rfcomm_dlc_lock(d);
163 	rfcomm_pi(sk)->dlc = NULL;
164 
165 	/* Detach DLC if it's owned by this socket */
166 	if (d->owner == sk)
167 		d->owner = NULL;
168 	rfcomm_dlc_unlock(d);
169 
170 	rfcomm_dlc_put(d);
171 }
172 
173 static void rfcomm_sock_cleanup_listen(struct sock *parent)
174 {
175 	struct sock *sk;
176 
177 	BT_DBG("parent %p", parent);
178 
179 	/* Close not yet accepted dlcs */
180 	while ((sk = bt_accept_dequeue(parent, NULL))) {
181 		rfcomm_sock_close(sk);
182 		rfcomm_sock_kill(sk);
183 	}
184 
185 	parent->sk_state  = BT_CLOSED;
186 	sock_set_flag(parent, SOCK_ZAPPED);
187 }
188 
189 /* Kill socket (only if zapped and orphan)
190  * Must be called on unlocked socket.
191  */
192 static void rfcomm_sock_kill(struct sock *sk)
193 {
194 	if (!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket)
195 		return;
196 
197 	BT_DBG("sk %p state %d refcnt %d", sk, sk->sk_state, refcount_read(&sk->sk_refcnt));
198 
199 	/* Kill poor orphan */
200 	bt_sock_unlink(&rfcomm_sk_list, sk);
201 	sock_set_flag(sk, SOCK_DEAD);
202 	sock_put(sk);
203 }
204 
205 static void __rfcomm_sock_close(struct sock *sk)
206 {
207 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
208 
209 	BT_DBG("sk %p state %d socket %p", sk, sk->sk_state, sk->sk_socket);
210 
211 	switch (sk->sk_state) {
212 	case BT_LISTEN:
213 		rfcomm_sock_cleanup_listen(sk);
214 		break;
215 
216 	case BT_CONNECT:
217 	case BT_CONNECT2:
218 	case BT_CONFIG:
219 	case BT_CONNECTED:
220 		rfcomm_dlc_close(d, 0);
221 		fallthrough;
222 
223 	default:
224 		sock_set_flag(sk, SOCK_ZAPPED);
225 		break;
226 	}
227 }
228 
229 /* Close socket.
230  * Must be called on unlocked socket.
231  */
232 static void rfcomm_sock_close(struct sock *sk)
233 {
234 	lock_sock(sk);
235 	__rfcomm_sock_close(sk);
236 	release_sock(sk);
237 }
238 
239 static void rfcomm_sock_init(struct sock *sk, struct sock *parent)
240 {
241 	struct rfcomm_pinfo *pi = rfcomm_pi(sk);
242 
243 	BT_DBG("sk %p", sk);
244 
245 	if (parent) {
246 		sk->sk_type = parent->sk_type;
247 		pi->dlc->defer_setup = test_bit(BT_SK_DEFER_SETUP,
248 						&bt_sk(parent)->flags);
249 
250 		pi->sec_level = rfcomm_pi(parent)->sec_level;
251 		pi->role_switch = rfcomm_pi(parent)->role_switch;
252 
253 		security_sk_clone(parent, sk);
254 	} else {
255 		pi->dlc->defer_setup = 0;
256 
257 		pi->sec_level = BT_SECURITY_LOW;
258 		pi->role_switch = 0;
259 	}
260 
261 	pi->dlc->sec_level = pi->sec_level;
262 	pi->dlc->role_switch = pi->role_switch;
263 }
264 
265 static struct proto rfcomm_proto = {
266 	.name		= "RFCOMM",
267 	.owner		= THIS_MODULE,
268 	.obj_size	= sizeof(struct rfcomm_pinfo)
269 };
270 
271 static struct sock *rfcomm_sock_alloc(struct net *net, struct socket *sock,
272 				      int proto, gfp_t prio, int kern)
273 {
274 	struct rfcomm_dlc *d;
275 	struct sock *sk;
276 
277 	d = rfcomm_dlc_alloc(prio);
278 	if (!d)
279 		return NULL;
280 
281 	sk = bt_sock_alloc(net, sock, &rfcomm_proto, proto, prio, kern);
282 	if (!sk) {
283 		rfcomm_dlc_free(d);
284 		return NULL;
285 	}
286 
287 	d->data_ready   = rfcomm_sk_data_ready;
288 	d->state_change = rfcomm_sk_state_change;
289 
290 	rfcomm_pi(sk)->dlc = d;
291 	d->owner = sk;
292 
293 	sk->sk_destruct = rfcomm_sock_destruct;
294 	sk->sk_sndtimeo = RFCOMM_CONN_TIMEOUT;
295 
296 	sk->sk_sndbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10;
297 	sk->sk_rcvbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10;
298 
299 	bt_sock_link(&rfcomm_sk_list, sk);
300 
301 	BT_DBG("sk %p", sk);
302 	return sk;
303 }
304 
305 static int rfcomm_sock_create(struct net *net, struct socket *sock,
306 			      int protocol, int kern)
307 {
308 	struct sock *sk;
309 
310 	BT_DBG("sock %p", sock);
311 
312 	sock->state = SS_UNCONNECTED;
313 
314 	if (sock->type != SOCK_STREAM && sock->type != SOCK_RAW)
315 		return -ESOCKTNOSUPPORT;
316 
317 	sock->ops = &rfcomm_sock_ops;
318 
319 	sk = rfcomm_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern);
320 	if (!sk)
321 		return -ENOMEM;
322 
323 	rfcomm_sock_init(sk, NULL);
324 	return 0;
325 }
326 
327 static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
328 {
329 	struct sockaddr_rc sa;
330 	struct sock *sk = sock->sk;
331 	int len, err = 0;
332 
333 	if (!addr || addr_len < offsetofend(struct sockaddr, sa_family) ||
334 	    addr->sa_family != AF_BLUETOOTH)
335 		return -EINVAL;
336 
337 	memset(&sa, 0, sizeof(sa));
338 	len = min_t(unsigned int, sizeof(sa), addr_len);
339 	memcpy(&sa, addr, len);
340 
341 	BT_DBG("sk %p %pMR", sk, &sa.rc_bdaddr);
342 
343 	lock_sock(sk);
344 
345 	if (sk->sk_state != BT_OPEN) {
346 		err = -EBADFD;
347 		goto done;
348 	}
349 
350 	if (sk->sk_type != SOCK_STREAM) {
351 		err = -EINVAL;
352 		goto done;
353 	}
354 
355 	write_lock(&rfcomm_sk_list.lock);
356 
357 	if (sa.rc_channel &&
358 	    __rfcomm_get_listen_sock_by_addr(sa.rc_channel, &sa.rc_bdaddr)) {
359 		err = -EADDRINUSE;
360 	} else {
361 		/* Save source address */
362 		bacpy(&rfcomm_pi(sk)->src, &sa.rc_bdaddr);
363 		rfcomm_pi(sk)->channel = sa.rc_channel;
364 		sk->sk_state = BT_BOUND;
365 	}
366 
367 	write_unlock(&rfcomm_sk_list.lock);
368 
369 done:
370 	release_sock(sk);
371 	return err;
372 }
373 
374 static int rfcomm_sock_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags)
375 {
376 	struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
377 	struct sock *sk = sock->sk;
378 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
379 	int err = 0;
380 
381 	BT_DBG("sk %p", sk);
382 
383 	if (alen < sizeof(struct sockaddr_rc) ||
384 	    addr->sa_family != AF_BLUETOOTH)
385 		return -EINVAL;
386 
387 	sock_hold(sk);
388 	lock_sock(sk);
389 
390 	if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) {
391 		err = -EBADFD;
392 		goto done;
393 	}
394 
395 	if (sk->sk_type != SOCK_STREAM) {
396 		err = -EINVAL;
397 		goto done;
398 	}
399 
400 	sk->sk_state = BT_CONNECT;
401 	bacpy(&rfcomm_pi(sk)->dst, &sa->rc_bdaddr);
402 	rfcomm_pi(sk)->channel = sa->rc_channel;
403 
404 	d->sec_level = rfcomm_pi(sk)->sec_level;
405 	d->role_switch = rfcomm_pi(sk)->role_switch;
406 
407 	/* Drop sock lock to avoid potential deadlock with the RFCOMM lock */
408 	release_sock(sk);
409 	err = rfcomm_dlc_open(d, &rfcomm_pi(sk)->src, &sa->rc_bdaddr,
410 			      sa->rc_channel);
411 	lock_sock(sk);
412 	if (!err && !sock_flag(sk, SOCK_ZAPPED))
413 		err = bt_sock_wait_state(sk, BT_CONNECTED,
414 				sock_sndtimeo(sk, flags & O_NONBLOCK));
415 
416 done:
417 	release_sock(sk);
418 	sock_put(sk);
419 	return err;
420 }
421 
422 static int rfcomm_sock_listen(struct socket *sock, int backlog)
423 {
424 	struct sock *sk = sock->sk;
425 	int err = 0;
426 
427 	BT_DBG("sk %p backlog %d", sk, backlog);
428 
429 	lock_sock(sk);
430 
431 	if (sk->sk_state != BT_BOUND) {
432 		err = -EBADFD;
433 		goto done;
434 	}
435 
436 	if (sk->sk_type != SOCK_STREAM) {
437 		err = -EINVAL;
438 		goto done;
439 	}
440 
441 	if (!rfcomm_pi(sk)->channel) {
442 		bdaddr_t *src = &rfcomm_pi(sk)->src;
443 		u8 channel;
444 
445 		err = -EINVAL;
446 
447 		write_lock(&rfcomm_sk_list.lock);
448 
449 		for (channel = 1; channel < 31; channel++)
450 			if (!__rfcomm_get_listen_sock_by_addr(channel, src)) {
451 				rfcomm_pi(sk)->channel = channel;
452 				err = 0;
453 				break;
454 			}
455 
456 		write_unlock(&rfcomm_sk_list.lock);
457 
458 		if (err < 0)
459 			goto done;
460 	}
461 
462 	sk->sk_max_ack_backlog = backlog;
463 	sk->sk_ack_backlog = 0;
464 	sk->sk_state = BT_LISTEN;
465 
466 done:
467 	release_sock(sk);
468 	return err;
469 }
470 
471 static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock,
472 			      struct proto_accept_arg *arg)
473 {
474 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
475 	struct sock *sk = sock->sk, *nsk;
476 	long timeo;
477 	int err = 0;
478 
479 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
480 
481 	if (sk->sk_type != SOCK_STREAM) {
482 		err = -EINVAL;
483 		goto done;
484 	}
485 
486 	timeo = sock_rcvtimeo(sk, arg->flags & O_NONBLOCK);
487 
488 	BT_DBG("sk %p timeo %ld", sk, timeo);
489 
490 	/* Wait for an incoming connection. (wake-one). */
491 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
492 	while (1) {
493 		if (sk->sk_state != BT_LISTEN) {
494 			err = -EBADFD;
495 			break;
496 		}
497 
498 		nsk = bt_accept_dequeue(sk, newsock);
499 		if (nsk)
500 			break;
501 
502 		if (!timeo) {
503 			err = -EAGAIN;
504 			break;
505 		}
506 
507 		if (signal_pending(current)) {
508 			err = sock_intr_errno(timeo);
509 			break;
510 		}
511 
512 		release_sock(sk);
513 
514 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
515 
516 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
517 	}
518 	remove_wait_queue(sk_sleep(sk), &wait);
519 
520 	if (err)
521 		goto done;
522 
523 	newsock->state = SS_CONNECTED;
524 
525 	BT_DBG("new socket %p", nsk);
526 
527 done:
528 	release_sock(sk);
529 	return err;
530 }
531 
532 static int rfcomm_sock_getname(struct socket *sock, struct sockaddr *addr, int peer)
533 {
534 	struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
535 	struct sock *sk = sock->sk;
536 
537 	BT_DBG("sock %p, sk %p", sock, sk);
538 
539 	if (peer && sk->sk_state != BT_CONNECTED &&
540 	    sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2)
541 		return -ENOTCONN;
542 
543 	memset(sa, 0, sizeof(*sa));
544 	sa->rc_family  = AF_BLUETOOTH;
545 	sa->rc_channel = rfcomm_pi(sk)->channel;
546 	if (peer)
547 		bacpy(&sa->rc_bdaddr, &rfcomm_pi(sk)->dst);
548 	else
549 		bacpy(&sa->rc_bdaddr, &rfcomm_pi(sk)->src);
550 
551 	return sizeof(struct sockaddr_rc);
552 }
553 
554 static int rfcomm_sock_sendmsg(struct socket *sock, struct msghdr *msg,
555 			       size_t len)
556 {
557 	struct sock *sk = sock->sk;
558 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
559 	struct sk_buff *skb;
560 	int sent;
561 
562 	if (test_bit(RFCOMM_DEFER_SETUP, &d->flags))
563 		return -ENOTCONN;
564 
565 	if (msg->msg_flags & MSG_OOB)
566 		return -EOPNOTSUPP;
567 
568 	if (sk->sk_shutdown & SEND_SHUTDOWN)
569 		return -EPIPE;
570 
571 	BT_DBG("sock %p, sk %p", sock, sk);
572 
573 	lock_sock(sk);
574 
575 	sent = bt_sock_wait_ready(sk, msg->msg_flags);
576 
577 	release_sock(sk);
578 
579 	if (sent)
580 		return sent;
581 
582 	skb = bt_skb_sendmmsg(sk, msg, len, d->mtu, RFCOMM_SKB_HEAD_RESERVE,
583 			      RFCOMM_SKB_TAIL_RESERVE);
584 	if (IS_ERR(skb))
585 		return PTR_ERR(skb);
586 
587 	sent = rfcomm_dlc_send(d, skb);
588 	if (sent < 0)
589 		kfree_skb(skb);
590 
591 	return sent;
592 }
593 
594 static int rfcomm_sock_recvmsg(struct socket *sock, struct msghdr *msg,
595 			       size_t size, int flags)
596 {
597 	struct sock *sk = sock->sk;
598 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
599 	int len;
600 
601 	if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
602 		rfcomm_dlc_accept(d);
603 		return 0;
604 	}
605 
606 	len = bt_sock_stream_recvmsg(sock, msg, size, flags);
607 
608 	lock_sock(sk);
609 	if (!(flags & MSG_PEEK) && len > 0)
610 		atomic_sub(len, &sk->sk_rmem_alloc);
611 
612 	if (atomic_read(&sk->sk_rmem_alloc) <= (sk->sk_rcvbuf >> 2))
613 		rfcomm_dlc_unthrottle(rfcomm_pi(sk)->dlc);
614 	release_sock(sk);
615 
616 	return len;
617 }
618 
619 static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname,
620 		sockptr_t optval, unsigned int optlen)
621 {
622 	struct sock *sk = sock->sk;
623 	int err = 0;
624 	u32 opt;
625 
626 	BT_DBG("sk %p", sk);
627 
628 	lock_sock(sk);
629 
630 	switch (optname) {
631 	case RFCOMM_LM:
632 		if (bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen)) {
633 			err = -EFAULT;
634 			break;
635 		}
636 
637 		if (opt & RFCOMM_LM_FIPS) {
638 			err = -EINVAL;
639 			break;
640 		}
641 
642 		if (opt & RFCOMM_LM_AUTH)
643 			rfcomm_pi(sk)->sec_level = BT_SECURITY_LOW;
644 		if (opt & RFCOMM_LM_ENCRYPT)
645 			rfcomm_pi(sk)->sec_level = BT_SECURITY_MEDIUM;
646 		if (opt & RFCOMM_LM_SECURE)
647 			rfcomm_pi(sk)->sec_level = BT_SECURITY_HIGH;
648 
649 		rfcomm_pi(sk)->role_switch = (opt & RFCOMM_LM_MASTER);
650 		break;
651 
652 	default:
653 		err = -ENOPROTOOPT;
654 		break;
655 	}
656 
657 	release_sock(sk);
658 	return err;
659 }
660 
661 static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
662 		sockptr_t optval, unsigned int optlen)
663 {
664 	struct sock *sk = sock->sk;
665 	struct bt_security sec;
666 	int err = 0;
667 	u32 opt;
668 
669 	BT_DBG("sk %p", sk);
670 
671 	if (level == SOL_RFCOMM)
672 		return rfcomm_sock_setsockopt_old(sock, optname, optval, optlen);
673 
674 	if (level != SOL_BLUETOOTH)
675 		return -ENOPROTOOPT;
676 
677 	lock_sock(sk);
678 
679 	switch (optname) {
680 	case BT_SECURITY:
681 		if (sk->sk_type != SOCK_STREAM) {
682 			err = -EINVAL;
683 			break;
684 		}
685 
686 		sec.level = BT_SECURITY_LOW;
687 
688 		err = bt_copy_from_sockptr(&sec, sizeof(sec), optval, optlen);
689 		if (err)
690 			break;
691 
692 		if (sec.level > BT_SECURITY_HIGH) {
693 			err = -EINVAL;
694 			break;
695 		}
696 
697 		rfcomm_pi(sk)->sec_level = sec.level;
698 		break;
699 
700 	case BT_DEFER_SETUP:
701 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
702 			err = -EINVAL;
703 			break;
704 		}
705 
706 		err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen);
707 		if (err)
708 			break;
709 
710 		if (opt)
711 			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
712 		else
713 			clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
714 
715 		break;
716 
717 	default:
718 		err = -ENOPROTOOPT;
719 		break;
720 	}
721 
722 	release_sock(sk);
723 	return err;
724 }
725 
726 static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __user *optval, int __user *optlen)
727 {
728 	struct sock *sk = sock->sk;
729 	struct sock *l2cap_sk;
730 	struct l2cap_conn *conn;
731 	struct rfcomm_conninfo cinfo;
732 	int err = 0;
733 	size_t len;
734 	u32 opt;
735 
736 	BT_DBG("sk %p", sk);
737 
738 	if (get_user(len, optlen))
739 		return -EFAULT;
740 
741 	lock_sock(sk);
742 
743 	switch (optname) {
744 	case RFCOMM_LM:
745 		switch (rfcomm_pi(sk)->sec_level) {
746 		case BT_SECURITY_LOW:
747 			opt = RFCOMM_LM_AUTH;
748 			break;
749 		case BT_SECURITY_MEDIUM:
750 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT;
751 			break;
752 		case BT_SECURITY_HIGH:
753 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
754 			      RFCOMM_LM_SECURE;
755 			break;
756 		case BT_SECURITY_FIPS:
757 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
758 			      RFCOMM_LM_SECURE | RFCOMM_LM_FIPS;
759 			break;
760 		default:
761 			opt = 0;
762 			break;
763 		}
764 
765 		if (rfcomm_pi(sk)->role_switch)
766 			opt |= RFCOMM_LM_MASTER;
767 
768 		if (put_user(opt, (u32 __user *) optval))
769 			err = -EFAULT;
770 
771 		break;
772 
773 	case RFCOMM_CONNINFO:
774 		if (sk->sk_state != BT_CONNECTED &&
775 					!rfcomm_pi(sk)->dlc->defer_setup) {
776 			err = -ENOTCONN;
777 			break;
778 		}
779 
780 		l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;
781 		conn = l2cap_pi(l2cap_sk)->chan->conn;
782 
783 		memset(&cinfo, 0, sizeof(cinfo));
784 		cinfo.hci_handle = conn->hcon->handle;
785 		memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);
786 
787 		len = min(len, sizeof(cinfo));
788 		if (copy_to_user(optval, (char *) &cinfo, len))
789 			err = -EFAULT;
790 
791 		break;
792 
793 	default:
794 		err = -ENOPROTOOPT;
795 		break;
796 	}
797 
798 	release_sock(sk);
799 	return err;
800 }
801 
802 static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
803 {
804 	struct sock *sk = sock->sk;
805 	struct bt_security sec;
806 	int err = 0;
807 	size_t len;
808 
809 	BT_DBG("sk %p", sk);
810 
811 	if (level == SOL_RFCOMM)
812 		return rfcomm_sock_getsockopt_old(sock, optname, optval, optlen);
813 
814 	if (level != SOL_BLUETOOTH)
815 		return -ENOPROTOOPT;
816 
817 	if (get_user(len, optlen))
818 		return -EFAULT;
819 
820 	lock_sock(sk);
821 
822 	switch (optname) {
823 	case BT_SECURITY:
824 		if (sk->sk_type != SOCK_STREAM) {
825 			err = -EINVAL;
826 			break;
827 		}
828 
829 		sec.level = rfcomm_pi(sk)->sec_level;
830 		sec.key_size = 0;
831 
832 		len = min(len, sizeof(sec));
833 		if (copy_to_user(optval, (char *) &sec, len))
834 			err = -EFAULT;
835 
836 		break;
837 
838 	case BT_DEFER_SETUP:
839 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
840 			err = -EINVAL;
841 			break;
842 		}
843 
844 		if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
845 			     (u32 __user *) optval))
846 			err = -EFAULT;
847 
848 		break;
849 
850 	default:
851 		err = -ENOPROTOOPT;
852 		break;
853 	}
854 
855 	release_sock(sk);
856 	return err;
857 }
858 
859 static int rfcomm_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
860 {
861 	struct sock *sk __maybe_unused = sock->sk;
862 	int err;
863 
864 	BT_DBG("sk %p cmd %x arg %lx", sk, cmd, arg);
865 
866 	err = bt_sock_ioctl(sock, cmd, arg);
867 
868 	if (err == -ENOIOCTLCMD) {
869 #ifdef CONFIG_BT_RFCOMM_TTY
870 		err = rfcomm_dev_ioctl(sk, cmd, (void __user *) arg);
871 #else
872 		err = -EOPNOTSUPP;
873 #endif
874 	}
875 
876 	return err;
877 }
878 
879 #ifdef CONFIG_COMPAT
880 static int rfcomm_sock_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
881 {
882 	return rfcomm_sock_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
883 }
884 #endif
885 
886 static int rfcomm_sock_shutdown(struct socket *sock, int how)
887 {
888 	struct sock *sk = sock->sk;
889 	int err = 0;
890 
891 	BT_DBG("sock %p, sk %p", sock, sk);
892 
893 	if (!sk)
894 		return 0;
895 
896 	lock_sock(sk);
897 	if (!sk->sk_shutdown) {
898 		sk->sk_shutdown = SHUTDOWN_MASK;
899 
900 		release_sock(sk);
901 		__rfcomm_sock_close(sk);
902 		lock_sock(sk);
903 
904 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
905 		    !(current->flags & PF_EXITING))
906 			err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
907 	}
908 	release_sock(sk);
909 	return err;
910 }
911 
912 static int rfcomm_sock_release(struct socket *sock)
913 {
914 	struct sock *sk = sock->sk;
915 	int err;
916 
917 	BT_DBG("sock %p, sk %p", sock, sk);
918 
919 	if (!sk)
920 		return 0;
921 
922 	err = rfcomm_sock_shutdown(sock, 2);
923 
924 	sock_orphan(sk);
925 	rfcomm_sock_kill(sk);
926 	return err;
927 }
928 
929 /* ---- RFCOMM core layer callbacks ----
930  *
931  * called under rfcomm_lock()
932  */
933 int rfcomm_connect_ind(struct rfcomm_session *s, u8 channel, struct rfcomm_dlc **d)
934 {
935 	struct sock *sk, *parent;
936 	bdaddr_t src, dst;
937 	int result = 0;
938 
939 	BT_DBG("session %p channel %d", s, channel);
940 
941 	rfcomm_session_getaddr(s, &src, &dst);
942 
943 	/* Check if we have socket listening on channel */
944 	parent = rfcomm_get_sock_by_channel(BT_LISTEN, channel, &src);
945 	if (!parent)
946 		return 0;
947 
948 	lock_sock(parent);
949 
950 	/* Check for backlog size */
951 	if (sk_acceptq_is_full(parent)) {
952 		BT_DBG("backlog full %d", parent->sk_ack_backlog);
953 		goto done;
954 	}
955 
956 	sk = rfcomm_sock_alloc(sock_net(parent), NULL, BTPROTO_RFCOMM, GFP_ATOMIC, 0);
957 	if (!sk)
958 		goto done;
959 
960 	bt_sock_reclassify_lock(sk, BTPROTO_RFCOMM);
961 
962 	rfcomm_sock_init(sk, parent);
963 	bacpy(&rfcomm_pi(sk)->src, &src);
964 	bacpy(&rfcomm_pi(sk)->dst, &dst);
965 	rfcomm_pi(sk)->channel = channel;
966 
967 	sk->sk_state = BT_CONFIG;
968 	bt_accept_enqueue(parent, sk, true);
969 
970 	/* Accept connection and return socket DLC */
971 	*d = rfcomm_pi(sk)->dlc;
972 	result = 1;
973 
974 done:
975 	release_sock(parent);
976 
977 	if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags))
978 		parent->sk_state_change(parent);
979 
980 	return result;
981 }
982 
983 static int rfcomm_sock_debugfs_show(struct seq_file *f, void *p)
984 {
985 	struct sock *sk;
986 
987 	read_lock(&rfcomm_sk_list.lock);
988 
989 	sk_for_each(sk, &rfcomm_sk_list.head) {
990 		seq_printf(f, "%pMR %pMR %d %d\n",
991 			   &rfcomm_pi(sk)->src, &rfcomm_pi(sk)->dst,
992 			   sk->sk_state, rfcomm_pi(sk)->channel);
993 	}
994 
995 	read_unlock(&rfcomm_sk_list.lock);
996 
997 	return 0;
998 }
999 
1000 DEFINE_SHOW_ATTRIBUTE(rfcomm_sock_debugfs);
1001 
1002 static struct dentry *rfcomm_sock_debugfs;
1003 
1004 static const struct proto_ops rfcomm_sock_ops = {
1005 	.family		= PF_BLUETOOTH,
1006 	.owner		= THIS_MODULE,
1007 	.release	= rfcomm_sock_release,
1008 	.bind		= rfcomm_sock_bind,
1009 	.connect	= rfcomm_sock_connect,
1010 	.listen		= rfcomm_sock_listen,
1011 	.accept		= rfcomm_sock_accept,
1012 	.getname	= rfcomm_sock_getname,
1013 	.sendmsg	= rfcomm_sock_sendmsg,
1014 	.recvmsg	= rfcomm_sock_recvmsg,
1015 	.shutdown	= rfcomm_sock_shutdown,
1016 	.setsockopt	= rfcomm_sock_setsockopt,
1017 	.getsockopt	= rfcomm_sock_getsockopt,
1018 	.ioctl		= rfcomm_sock_ioctl,
1019 	.gettstamp	= sock_gettstamp,
1020 	.poll		= bt_sock_poll,
1021 	.socketpair	= sock_no_socketpair,
1022 	.mmap		= sock_no_mmap,
1023 #ifdef CONFIG_COMPAT
1024 	.compat_ioctl	= rfcomm_sock_compat_ioctl,
1025 #endif
1026 };
1027 
1028 static const struct net_proto_family rfcomm_sock_family_ops = {
1029 	.family		= PF_BLUETOOTH,
1030 	.owner		= THIS_MODULE,
1031 	.create		= rfcomm_sock_create
1032 };
1033 
1034 int __init rfcomm_init_sockets(void)
1035 {
1036 	int err;
1037 
1038 	BUILD_BUG_ON(sizeof(struct sockaddr_rc) > sizeof(struct sockaddr));
1039 
1040 	err = proto_register(&rfcomm_proto, 0);
1041 	if (err < 0)
1042 		return err;
1043 
1044 	err = bt_sock_register(BTPROTO_RFCOMM, &rfcomm_sock_family_ops);
1045 	if (err < 0) {
1046 		BT_ERR("RFCOMM socket layer registration failed");
1047 		goto error;
1048 	}
1049 
1050 	err = bt_procfs_init(&init_net, "rfcomm", &rfcomm_sk_list, NULL);
1051 	if (err < 0) {
1052 		BT_ERR("Failed to create RFCOMM proc file");
1053 		bt_sock_unregister(BTPROTO_RFCOMM);
1054 		goto error;
1055 	}
1056 
1057 	BT_INFO("RFCOMM socket layer initialized");
1058 
1059 	if (IS_ERR_OR_NULL(bt_debugfs))
1060 		return 0;
1061 
1062 	rfcomm_sock_debugfs = debugfs_create_file("rfcomm", 0444,
1063 						  bt_debugfs, NULL,
1064 						  &rfcomm_sock_debugfs_fops);
1065 
1066 	return 0;
1067 
1068 error:
1069 	proto_unregister(&rfcomm_proto);
1070 	return err;
1071 }
1072 
1073 void __exit rfcomm_cleanup_sockets(void)
1074 {
1075 	bt_procfs_cleanup(&init_net, "rfcomm");
1076 
1077 	debugfs_remove(rfcomm_sock_debugfs);
1078 
1079 	bt_sock_unregister(BTPROTO_RFCOMM);
1080 
1081 	proto_unregister(&rfcomm_proto);
1082 }
1083