xref: /linux/net/bluetooth/rfcomm/sock.c (revision 90e0d94d369d342e735a75174439482119b6c393)
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, int proto, gfp_t prio, int kern)
272 {
273 	struct rfcomm_dlc *d;
274 	struct sock *sk;
275 
276 	sk = sk_alloc(net, PF_BLUETOOTH, prio, &rfcomm_proto, kern);
277 	if (!sk)
278 		return NULL;
279 
280 	sock_init_data(sock, sk);
281 	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
282 
283 	d = rfcomm_dlc_alloc(prio);
284 	if (!d) {
285 		sk_free(sk);
286 		return NULL;
287 	}
288 
289 	d->data_ready   = rfcomm_sk_data_ready;
290 	d->state_change = rfcomm_sk_state_change;
291 
292 	rfcomm_pi(sk)->dlc = d;
293 	d->owner = sk;
294 
295 	sk->sk_destruct = rfcomm_sock_destruct;
296 	sk->sk_sndtimeo = RFCOMM_CONN_TIMEOUT;
297 
298 	sk->sk_sndbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10;
299 	sk->sk_rcvbuf = RFCOMM_MAX_CREDITS * RFCOMM_DEFAULT_MTU * 10;
300 
301 	sock_reset_flag(sk, SOCK_ZAPPED);
302 
303 	sk->sk_protocol = proto;
304 	sk->sk_state    = BT_OPEN;
305 
306 	bt_sock_link(&rfcomm_sk_list, sk);
307 
308 	BT_DBG("sk %p", sk);
309 	return sk;
310 }
311 
312 static int rfcomm_sock_create(struct net *net, struct socket *sock,
313 			      int protocol, int kern)
314 {
315 	struct sock *sk;
316 
317 	BT_DBG("sock %p", sock);
318 
319 	sock->state = SS_UNCONNECTED;
320 
321 	if (sock->type != SOCK_STREAM && sock->type != SOCK_RAW)
322 		return -ESOCKTNOSUPPORT;
323 
324 	sock->ops = &rfcomm_sock_ops;
325 
326 	sk = rfcomm_sock_alloc(net, sock, protocol, GFP_ATOMIC, kern);
327 	if (!sk)
328 		return -ENOMEM;
329 
330 	rfcomm_sock_init(sk, NULL);
331 	return 0;
332 }
333 
334 static int rfcomm_sock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
335 {
336 	struct sockaddr_rc sa;
337 	struct sock *sk = sock->sk;
338 	int len, err = 0;
339 
340 	if (!addr || addr_len < offsetofend(struct sockaddr, sa_family) ||
341 	    addr->sa_family != AF_BLUETOOTH)
342 		return -EINVAL;
343 
344 	memset(&sa, 0, sizeof(sa));
345 	len = min_t(unsigned int, sizeof(sa), addr_len);
346 	memcpy(&sa, addr, len);
347 
348 	BT_DBG("sk %p %pMR", sk, &sa.rc_bdaddr);
349 
350 	lock_sock(sk);
351 
352 	if (sk->sk_state != BT_OPEN) {
353 		err = -EBADFD;
354 		goto done;
355 	}
356 
357 	if (sk->sk_type != SOCK_STREAM) {
358 		err = -EINVAL;
359 		goto done;
360 	}
361 
362 	write_lock(&rfcomm_sk_list.lock);
363 
364 	if (sa.rc_channel &&
365 	    __rfcomm_get_listen_sock_by_addr(sa.rc_channel, &sa.rc_bdaddr)) {
366 		err = -EADDRINUSE;
367 	} else {
368 		/* Save source address */
369 		bacpy(&rfcomm_pi(sk)->src, &sa.rc_bdaddr);
370 		rfcomm_pi(sk)->channel = sa.rc_channel;
371 		sk->sk_state = BT_BOUND;
372 	}
373 
374 	write_unlock(&rfcomm_sk_list.lock);
375 
376 done:
377 	release_sock(sk);
378 	return err;
379 }
380 
381 static int rfcomm_sock_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags)
382 {
383 	struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
384 	struct sock *sk = sock->sk;
385 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
386 	int err = 0;
387 
388 	BT_DBG("sk %p", sk);
389 
390 	if (alen < sizeof(struct sockaddr_rc) ||
391 	    addr->sa_family != AF_BLUETOOTH)
392 		return -EINVAL;
393 
394 	lock_sock(sk);
395 
396 	if (sk->sk_state != BT_OPEN && sk->sk_state != BT_BOUND) {
397 		err = -EBADFD;
398 		goto done;
399 	}
400 
401 	if (sk->sk_type != SOCK_STREAM) {
402 		err = -EINVAL;
403 		goto done;
404 	}
405 
406 	sk->sk_state = BT_CONNECT;
407 	bacpy(&rfcomm_pi(sk)->dst, &sa->rc_bdaddr);
408 	rfcomm_pi(sk)->channel = sa->rc_channel;
409 
410 	d->sec_level = rfcomm_pi(sk)->sec_level;
411 	d->role_switch = rfcomm_pi(sk)->role_switch;
412 
413 	err = rfcomm_dlc_open(d, &rfcomm_pi(sk)->src, &sa->rc_bdaddr,
414 			      sa->rc_channel);
415 	if (!err)
416 		err = bt_sock_wait_state(sk, BT_CONNECTED,
417 				sock_sndtimeo(sk, flags & O_NONBLOCK));
418 
419 done:
420 	release_sock(sk);
421 	return err;
422 }
423 
424 static int rfcomm_sock_listen(struct socket *sock, int backlog)
425 {
426 	struct sock *sk = sock->sk;
427 	int err = 0;
428 
429 	BT_DBG("sk %p backlog %d", sk, backlog);
430 
431 	lock_sock(sk);
432 
433 	if (sk->sk_state != BT_BOUND) {
434 		err = -EBADFD;
435 		goto done;
436 	}
437 
438 	if (sk->sk_type != SOCK_STREAM) {
439 		err = -EINVAL;
440 		goto done;
441 	}
442 
443 	if (!rfcomm_pi(sk)->channel) {
444 		bdaddr_t *src = &rfcomm_pi(sk)->src;
445 		u8 channel;
446 
447 		err = -EINVAL;
448 
449 		write_lock(&rfcomm_sk_list.lock);
450 
451 		for (channel = 1; channel < 31; channel++)
452 			if (!__rfcomm_get_listen_sock_by_addr(channel, src)) {
453 				rfcomm_pi(sk)->channel = channel;
454 				err = 0;
455 				break;
456 			}
457 
458 		write_unlock(&rfcomm_sk_list.lock);
459 
460 		if (err < 0)
461 			goto done;
462 	}
463 
464 	sk->sk_max_ack_backlog = backlog;
465 	sk->sk_ack_backlog = 0;
466 	sk->sk_state = BT_LISTEN;
467 
468 done:
469 	release_sock(sk);
470 	return err;
471 }
472 
473 static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock, int flags,
474 			      bool kern)
475 {
476 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
477 	struct sock *sk = sock->sk, *nsk;
478 	long timeo;
479 	int err = 0;
480 
481 	lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
482 
483 	if (sk->sk_type != SOCK_STREAM) {
484 		err = -EINVAL;
485 		goto done;
486 	}
487 
488 	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
489 
490 	BT_DBG("sk %p timeo %ld", sk, timeo);
491 
492 	/* Wait for an incoming connection. (wake-one). */
493 	add_wait_queue_exclusive(sk_sleep(sk), &wait);
494 	while (1) {
495 		if (sk->sk_state != BT_LISTEN) {
496 			err = -EBADFD;
497 			break;
498 		}
499 
500 		nsk = bt_accept_dequeue(sk, newsock);
501 		if (nsk)
502 			break;
503 
504 		if (!timeo) {
505 			err = -EAGAIN;
506 			break;
507 		}
508 
509 		if (signal_pending(current)) {
510 			err = sock_intr_errno(timeo);
511 			break;
512 		}
513 
514 		release_sock(sk);
515 
516 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
517 
518 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
519 	}
520 	remove_wait_queue(sk_sleep(sk), &wait);
521 
522 	if (err)
523 		goto done;
524 
525 	newsock->state = SS_CONNECTED;
526 
527 	BT_DBG("new socket %p", nsk);
528 
529 done:
530 	release_sock(sk);
531 	return err;
532 }
533 
534 static int rfcomm_sock_getname(struct socket *sock, struct sockaddr *addr, int peer)
535 {
536 	struct sockaddr_rc *sa = (struct sockaddr_rc *) addr;
537 	struct sock *sk = sock->sk;
538 
539 	BT_DBG("sock %p, sk %p", sock, sk);
540 
541 	if (peer && sk->sk_state != BT_CONNECTED &&
542 	    sk->sk_state != BT_CONNECT && sk->sk_state != BT_CONNECT2)
543 		return -ENOTCONN;
544 
545 	memset(sa, 0, sizeof(*sa));
546 	sa->rc_family  = AF_BLUETOOTH;
547 	sa->rc_channel = rfcomm_pi(sk)->channel;
548 	if (peer)
549 		bacpy(&sa->rc_bdaddr, &rfcomm_pi(sk)->dst);
550 	else
551 		bacpy(&sa->rc_bdaddr, &rfcomm_pi(sk)->src);
552 
553 	return sizeof(struct sockaddr_rc);
554 }
555 
556 static int rfcomm_sock_sendmsg(struct socket *sock, struct msghdr *msg,
557 			       size_t len)
558 {
559 	struct sock *sk = sock->sk;
560 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
561 	struct sk_buff *skb;
562 	int sent;
563 
564 	if (test_bit(RFCOMM_DEFER_SETUP, &d->flags))
565 		return -ENOTCONN;
566 
567 	if (msg->msg_flags & MSG_OOB)
568 		return -EOPNOTSUPP;
569 
570 	if (sk->sk_shutdown & SEND_SHUTDOWN)
571 		return -EPIPE;
572 
573 	BT_DBG("sock %p, sk %p", sock, sk);
574 
575 	lock_sock(sk);
576 
577 	sent = bt_sock_wait_ready(sk, msg->msg_flags);
578 
579 	release_sock(sk);
580 
581 	if (sent)
582 		return sent;
583 
584 	skb = bt_skb_sendmmsg(sk, msg, len, d->mtu, RFCOMM_SKB_HEAD_RESERVE,
585 			      RFCOMM_SKB_TAIL_RESERVE);
586 	if (IS_ERR(skb))
587 		return PTR_ERR(skb);
588 
589 	sent = rfcomm_dlc_send(d, skb);
590 	if (sent < 0)
591 		kfree_skb(skb);
592 
593 	return sent;
594 }
595 
596 static int rfcomm_sock_recvmsg(struct socket *sock, struct msghdr *msg,
597 			       size_t size, int flags)
598 {
599 	struct sock *sk = sock->sk;
600 	struct rfcomm_dlc *d = rfcomm_pi(sk)->dlc;
601 	int len;
602 
603 	if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
604 		rfcomm_dlc_accept(d);
605 		return 0;
606 	}
607 
608 	len = bt_sock_stream_recvmsg(sock, msg, size, flags);
609 
610 	lock_sock(sk);
611 	if (!(flags & MSG_PEEK) && len > 0)
612 		atomic_sub(len, &sk->sk_rmem_alloc);
613 
614 	if (atomic_read(&sk->sk_rmem_alloc) <= (sk->sk_rcvbuf >> 2))
615 		rfcomm_dlc_unthrottle(rfcomm_pi(sk)->dlc);
616 	release_sock(sk);
617 
618 	return len;
619 }
620 
621 static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname,
622 		sockptr_t optval, unsigned int optlen)
623 {
624 	struct sock *sk = sock->sk;
625 	int err = 0;
626 	u32 opt;
627 
628 	BT_DBG("sk %p", sk);
629 
630 	lock_sock(sk);
631 
632 	switch (optname) {
633 	case RFCOMM_LM:
634 		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
635 			err = -EFAULT;
636 			break;
637 		}
638 
639 		if (opt & RFCOMM_LM_FIPS) {
640 			err = -EINVAL;
641 			break;
642 		}
643 
644 		if (opt & RFCOMM_LM_AUTH)
645 			rfcomm_pi(sk)->sec_level = BT_SECURITY_LOW;
646 		if (opt & RFCOMM_LM_ENCRYPT)
647 			rfcomm_pi(sk)->sec_level = BT_SECURITY_MEDIUM;
648 		if (opt & RFCOMM_LM_SECURE)
649 			rfcomm_pi(sk)->sec_level = BT_SECURITY_HIGH;
650 
651 		rfcomm_pi(sk)->role_switch = (opt & RFCOMM_LM_MASTER);
652 		break;
653 
654 	default:
655 		err = -ENOPROTOOPT;
656 		break;
657 	}
658 
659 	release_sock(sk);
660 	return err;
661 }
662 
663 static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
664 		sockptr_t optval, unsigned int optlen)
665 {
666 	struct sock *sk = sock->sk;
667 	struct bt_security sec;
668 	int err = 0;
669 	size_t len;
670 	u32 opt;
671 
672 	BT_DBG("sk %p", sk);
673 
674 	if (level == SOL_RFCOMM)
675 		return rfcomm_sock_setsockopt_old(sock, optname, optval, optlen);
676 
677 	if (level != SOL_BLUETOOTH)
678 		return -ENOPROTOOPT;
679 
680 	lock_sock(sk);
681 
682 	switch (optname) {
683 	case BT_SECURITY:
684 		if (sk->sk_type != SOCK_STREAM) {
685 			err = -EINVAL;
686 			break;
687 		}
688 
689 		sec.level = BT_SECURITY_LOW;
690 
691 		len = min_t(unsigned int, sizeof(sec), optlen);
692 		if (copy_from_sockptr(&sec, optval, len)) {
693 			err = -EFAULT;
694 			break;
695 		}
696 
697 		if (sec.level > BT_SECURITY_HIGH) {
698 			err = -EINVAL;
699 			break;
700 		}
701 
702 		rfcomm_pi(sk)->sec_level = sec.level;
703 		break;
704 
705 	case BT_DEFER_SETUP:
706 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
707 			err = -EINVAL;
708 			break;
709 		}
710 
711 		if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
712 			err = -EFAULT;
713 			break;
714 		}
715 
716 		if (opt)
717 			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
718 		else
719 			clear_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);
720 
721 		break;
722 
723 	default:
724 		err = -ENOPROTOOPT;
725 		break;
726 	}
727 
728 	release_sock(sk);
729 	return err;
730 }
731 
732 static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname, char __user *optval, int __user *optlen)
733 {
734 	struct sock *sk = sock->sk;
735 	struct sock *l2cap_sk;
736 	struct l2cap_conn *conn;
737 	struct rfcomm_conninfo cinfo;
738 	int len, err = 0;
739 	u32 opt;
740 
741 	BT_DBG("sk %p", sk);
742 
743 	if (get_user(len, optlen))
744 		return -EFAULT;
745 
746 	lock_sock(sk);
747 
748 	switch (optname) {
749 	case RFCOMM_LM:
750 		switch (rfcomm_pi(sk)->sec_level) {
751 		case BT_SECURITY_LOW:
752 			opt = RFCOMM_LM_AUTH;
753 			break;
754 		case BT_SECURITY_MEDIUM:
755 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT;
756 			break;
757 		case BT_SECURITY_HIGH:
758 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
759 			      RFCOMM_LM_SECURE;
760 			break;
761 		case BT_SECURITY_FIPS:
762 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
763 			      RFCOMM_LM_SECURE | RFCOMM_LM_FIPS;
764 			break;
765 		default:
766 			opt = 0;
767 			break;
768 		}
769 
770 		if (rfcomm_pi(sk)->role_switch)
771 			opt |= RFCOMM_LM_MASTER;
772 
773 		if (put_user(opt, (u32 __user *) optval))
774 			err = -EFAULT;
775 
776 		break;
777 
778 	case RFCOMM_CONNINFO:
779 		if (sk->sk_state != BT_CONNECTED &&
780 					!rfcomm_pi(sk)->dlc->defer_setup) {
781 			err = -ENOTCONN;
782 			break;
783 		}
784 
785 		l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;
786 		conn = l2cap_pi(l2cap_sk)->chan->conn;
787 
788 		memset(&cinfo, 0, sizeof(cinfo));
789 		cinfo.hci_handle = conn->hcon->handle;
790 		memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);
791 
792 		len = min_t(unsigned int, len, sizeof(cinfo));
793 		if (copy_to_user(optval, (char *) &cinfo, len))
794 			err = -EFAULT;
795 
796 		break;
797 
798 	default:
799 		err = -ENOPROTOOPT;
800 		break;
801 	}
802 
803 	release_sock(sk);
804 	return err;
805 }
806 
807 static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
808 {
809 	struct sock *sk = sock->sk;
810 	struct bt_security sec;
811 	int len, err = 0;
812 
813 	BT_DBG("sk %p", sk);
814 
815 	if (level == SOL_RFCOMM)
816 		return rfcomm_sock_getsockopt_old(sock, optname, optval, optlen);
817 
818 	if (level != SOL_BLUETOOTH)
819 		return -ENOPROTOOPT;
820 
821 	if (get_user(len, optlen))
822 		return -EFAULT;
823 
824 	lock_sock(sk);
825 
826 	switch (optname) {
827 	case BT_SECURITY:
828 		if (sk->sk_type != SOCK_STREAM) {
829 			err = -EINVAL;
830 			break;
831 		}
832 
833 		sec.level = rfcomm_pi(sk)->sec_level;
834 		sec.key_size = 0;
835 
836 		len = min_t(unsigned int, len, sizeof(sec));
837 		if (copy_to_user(optval, (char *) &sec, len))
838 			err = -EFAULT;
839 
840 		break;
841 
842 	case BT_DEFER_SETUP:
843 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
844 			err = -EINVAL;
845 			break;
846 		}
847 
848 		if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
849 			     (u32 __user *) optval))
850 			err = -EFAULT;
851 
852 		break;
853 
854 	default:
855 		err = -ENOPROTOOPT;
856 		break;
857 	}
858 
859 	release_sock(sk);
860 	return err;
861 }
862 
863 static int rfcomm_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
864 {
865 	struct sock *sk __maybe_unused = sock->sk;
866 	int err;
867 
868 	BT_DBG("sk %p cmd %x arg %lx", sk, cmd, arg);
869 
870 	err = bt_sock_ioctl(sock, cmd, arg);
871 
872 	if (err == -ENOIOCTLCMD) {
873 #ifdef CONFIG_BT_RFCOMM_TTY
874 		lock_sock(sk);
875 		err = rfcomm_dev_ioctl(sk, cmd, (void __user *) arg);
876 		release_sock(sk);
877 #else
878 		err = -EOPNOTSUPP;
879 #endif
880 	}
881 
882 	return err;
883 }
884 
885 #ifdef CONFIG_COMPAT
886 static int rfcomm_sock_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
887 {
888 	return rfcomm_sock_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
889 }
890 #endif
891 
892 static int rfcomm_sock_shutdown(struct socket *sock, int how)
893 {
894 	struct sock *sk = sock->sk;
895 	int err = 0;
896 
897 	BT_DBG("sock %p, sk %p", sock, sk);
898 
899 	if (!sk)
900 		return 0;
901 
902 	lock_sock(sk);
903 	if (!sk->sk_shutdown) {
904 		sk->sk_shutdown = SHUTDOWN_MASK;
905 
906 		release_sock(sk);
907 		__rfcomm_sock_close(sk);
908 		lock_sock(sk);
909 
910 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
911 		    !(current->flags & PF_EXITING))
912 			err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
913 	}
914 	release_sock(sk);
915 	return err;
916 }
917 
918 static int rfcomm_sock_release(struct socket *sock)
919 {
920 	struct sock *sk = sock->sk;
921 	int err;
922 
923 	BT_DBG("sock %p, sk %p", sock, sk);
924 
925 	if (!sk)
926 		return 0;
927 
928 	err = rfcomm_sock_shutdown(sock, 2);
929 
930 	sock_orphan(sk);
931 	rfcomm_sock_kill(sk);
932 	return err;
933 }
934 
935 /* ---- RFCOMM core layer callbacks ----
936  *
937  * called under rfcomm_lock()
938  */
939 int rfcomm_connect_ind(struct rfcomm_session *s, u8 channel, struct rfcomm_dlc **d)
940 {
941 	struct sock *sk, *parent;
942 	bdaddr_t src, dst;
943 	int result = 0;
944 
945 	BT_DBG("session %p channel %d", s, channel);
946 
947 	rfcomm_session_getaddr(s, &src, &dst);
948 
949 	/* Check if we have socket listening on channel */
950 	parent = rfcomm_get_sock_by_channel(BT_LISTEN, channel, &src);
951 	if (!parent)
952 		return 0;
953 
954 	lock_sock(parent);
955 
956 	/* Check for backlog size */
957 	if (sk_acceptq_is_full(parent)) {
958 		BT_DBG("backlog full %d", parent->sk_ack_backlog);
959 		goto done;
960 	}
961 
962 	sk = rfcomm_sock_alloc(sock_net(parent), NULL, BTPROTO_RFCOMM, GFP_ATOMIC, 0);
963 	if (!sk)
964 		goto done;
965 
966 	bt_sock_reclassify_lock(sk, BTPROTO_RFCOMM);
967 
968 	rfcomm_sock_init(sk, parent);
969 	bacpy(&rfcomm_pi(sk)->src, &src);
970 	bacpy(&rfcomm_pi(sk)->dst, &dst);
971 	rfcomm_pi(sk)->channel = channel;
972 
973 	sk->sk_state = BT_CONFIG;
974 	bt_accept_enqueue(parent, sk, true);
975 
976 	/* Accept connection and return socket DLC */
977 	*d = rfcomm_pi(sk)->dlc;
978 	result = 1;
979 
980 done:
981 	release_sock(parent);
982 
983 	if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags))
984 		parent->sk_state_change(parent);
985 
986 	return result;
987 }
988 
989 static int rfcomm_sock_debugfs_show(struct seq_file *f, void *p)
990 {
991 	struct sock *sk;
992 
993 	read_lock(&rfcomm_sk_list.lock);
994 
995 	sk_for_each(sk, &rfcomm_sk_list.head) {
996 		seq_printf(f, "%pMR %pMR %d %d\n",
997 			   &rfcomm_pi(sk)->src, &rfcomm_pi(sk)->dst,
998 			   sk->sk_state, rfcomm_pi(sk)->channel);
999 	}
1000 
1001 	read_unlock(&rfcomm_sk_list.lock);
1002 
1003 	return 0;
1004 }
1005 
1006 DEFINE_SHOW_ATTRIBUTE(rfcomm_sock_debugfs);
1007 
1008 static struct dentry *rfcomm_sock_debugfs;
1009 
1010 static const struct proto_ops rfcomm_sock_ops = {
1011 	.family		= PF_BLUETOOTH,
1012 	.owner		= THIS_MODULE,
1013 	.release	= rfcomm_sock_release,
1014 	.bind		= rfcomm_sock_bind,
1015 	.connect	= rfcomm_sock_connect,
1016 	.listen		= rfcomm_sock_listen,
1017 	.accept		= rfcomm_sock_accept,
1018 	.getname	= rfcomm_sock_getname,
1019 	.sendmsg	= rfcomm_sock_sendmsg,
1020 	.recvmsg	= rfcomm_sock_recvmsg,
1021 	.shutdown	= rfcomm_sock_shutdown,
1022 	.setsockopt	= rfcomm_sock_setsockopt,
1023 	.getsockopt	= rfcomm_sock_getsockopt,
1024 	.ioctl		= rfcomm_sock_ioctl,
1025 	.gettstamp	= sock_gettstamp,
1026 	.poll		= bt_sock_poll,
1027 	.socketpair	= sock_no_socketpair,
1028 	.mmap		= sock_no_mmap,
1029 #ifdef CONFIG_COMPAT
1030 	.compat_ioctl	= rfcomm_sock_compat_ioctl,
1031 #endif
1032 };
1033 
1034 static const struct net_proto_family rfcomm_sock_family_ops = {
1035 	.family		= PF_BLUETOOTH,
1036 	.owner		= THIS_MODULE,
1037 	.create		= rfcomm_sock_create
1038 };
1039 
1040 int __init rfcomm_init_sockets(void)
1041 {
1042 	int err;
1043 
1044 	BUILD_BUG_ON(sizeof(struct sockaddr_rc) > sizeof(struct sockaddr));
1045 
1046 	err = proto_register(&rfcomm_proto, 0);
1047 	if (err < 0)
1048 		return err;
1049 
1050 	err = bt_sock_register(BTPROTO_RFCOMM, &rfcomm_sock_family_ops);
1051 	if (err < 0) {
1052 		BT_ERR("RFCOMM socket layer registration failed");
1053 		goto error;
1054 	}
1055 
1056 	err = bt_procfs_init(&init_net, "rfcomm", &rfcomm_sk_list, NULL);
1057 	if (err < 0) {
1058 		BT_ERR("Failed to create RFCOMM proc file");
1059 		bt_sock_unregister(BTPROTO_RFCOMM);
1060 		goto error;
1061 	}
1062 
1063 	BT_INFO("RFCOMM socket layer initialized");
1064 
1065 	if (IS_ERR_OR_NULL(bt_debugfs))
1066 		return 0;
1067 
1068 	rfcomm_sock_debugfs = debugfs_create_file("rfcomm", 0444,
1069 						  bt_debugfs, NULL,
1070 						  &rfcomm_sock_debugfs_fops);
1071 
1072 	return 0;
1073 
1074 error:
1075 	proto_unregister(&rfcomm_proto);
1076 	return err;
1077 }
1078 
1079 void __exit rfcomm_cleanup_sockets(void)
1080 {
1081 	bt_procfs_cleanup(&init_net, "rfcomm");
1082 
1083 	debugfs_remove(rfcomm_sock_debugfs);
1084 
1085 	bt_sock_unregister(BTPROTO_RFCOMM);
1086 
1087 	proto_unregister(&rfcomm_proto);
1088 }
1089