xref: /linux/net/bluetooth/rfcomm/sock.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 	sk = bt_sock_alloc(net, sock, &rfcomm_proto, proto, prio, kern);
278 	if (!sk)
279 		return NULL;
280 
281 	d = rfcomm_dlc_alloc(prio);
282 	if (!d) {
283 		sk_free(sk);
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 len, err = 0;
733 	u32 opt;
734 
735 	BT_DBG("sk %p", sk);
736 
737 	if (get_user(len, optlen))
738 		return -EFAULT;
739 
740 	lock_sock(sk);
741 
742 	switch (optname) {
743 	case RFCOMM_LM:
744 		switch (rfcomm_pi(sk)->sec_level) {
745 		case BT_SECURITY_LOW:
746 			opt = RFCOMM_LM_AUTH;
747 			break;
748 		case BT_SECURITY_MEDIUM:
749 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT;
750 			break;
751 		case BT_SECURITY_HIGH:
752 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
753 			      RFCOMM_LM_SECURE;
754 			break;
755 		case BT_SECURITY_FIPS:
756 			opt = RFCOMM_LM_AUTH | RFCOMM_LM_ENCRYPT |
757 			      RFCOMM_LM_SECURE | RFCOMM_LM_FIPS;
758 			break;
759 		default:
760 			opt = 0;
761 			break;
762 		}
763 
764 		if (rfcomm_pi(sk)->role_switch)
765 			opt |= RFCOMM_LM_MASTER;
766 
767 		if (put_user(opt, (u32 __user *) optval))
768 			err = -EFAULT;
769 
770 		break;
771 
772 	case RFCOMM_CONNINFO:
773 		if (sk->sk_state != BT_CONNECTED &&
774 					!rfcomm_pi(sk)->dlc->defer_setup) {
775 			err = -ENOTCONN;
776 			break;
777 		}
778 
779 		l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;
780 		conn = l2cap_pi(l2cap_sk)->chan->conn;
781 
782 		memset(&cinfo, 0, sizeof(cinfo));
783 		cinfo.hci_handle = conn->hcon->handle;
784 		memcpy(cinfo.dev_class, conn->hcon->dev_class, 3);
785 
786 		len = min_t(unsigned int, len, sizeof(cinfo));
787 		if (copy_to_user(optval, (char *) &cinfo, len))
788 			err = -EFAULT;
789 
790 		break;
791 
792 	default:
793 		err = -ENOPROTOOPT;
794 		break;
795 	}
796 
797 	release_sock(sk);
798 	return err;
799 }
800 
801 static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
802 {
803 	struct sock *sk = sock->sk;
804 	struct bt_security sec;
805 	int len, err = 0;
806 
807 	BT_DBG("sk %p", sk);
808 
809 	if (level == SOL_RFCOMM)
810 		return rfcomm_sock_getsockopt_old(sock, optname, optval, optlen);
811 
812 	if (level != SOL_BLUETOOTH)
813 		return -ENOPROTOOPT;
814 
815 	if (get_user(len, optlen))
816 		return -EFAULT;
817 
818 	lock_sock(sk);
819 
820 	switch (optname) {
821 	case BT_SECURITY:
822 		if (sk->sk_type != SOCK_STREAM) {
823 			err = -EINVAL;
824 			break;
825 		}
826 
827 		sec.level = rfcomm_pi(sk)->sec_level;
828 		sec.key_size = 0;
829 
830 		len = min_t(unsigned int, len, sizeof(sec));
831 		if (copy_to_user(optval, (char *) &sec, len))
832 			err = -EFAULT;
833 
834 		break;
835 
836 	case BT_DEFER_SETUP:
837 		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
838 			err = -EINVAL;
839 			break;
840 		}
841 
842 		if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
843 			     (u32 __user *) optval))
844 			err = -EFAULT;
845 
846 		break;
847 
848 	default:
849 		err = -ENOPROTOOPT;
850 		break;
851 	}
852 
853 	release_sock(sk);
854 	return err;
855 }
856 
857 static int rfcomm_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
858 {
859 	struct sock *sk __maybe_unused = sock->sk;
860 	int err;
861 
862 	BT_DBG("sk %p cmd %x arg %lx", sk, cmd, arg);
863 
864 	err = bt_sock_ioctl(sock, cmd, arg);
865 
866 	if (err == -ENOIOCTLCMD) {
867 #ifdef CONFIG_BT_RFCOMM_TTY
868 		err = rfcomm_dev_ioctl(sk, cmd, (void __user *) arg);
869 #else
870 		err = -EOPNOTSUPP;
871 #endif
872 	}
873 
874 	return err;
875 }
876 
877 #ifdef CONFIG_COMPAT
878 static int rfcomm_sock_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
879 {
880 	return rfcomm_sock_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
881 }
882 #endif
883 
884 static int rfcomm_sock_shutdown(struct socket *sock, int how)
885 {
886 	struct sock *sk = sock->sk;
887 	int err = 0;
888 
889 	BT_DBG("sock %p, sk %p", sock, sk);
890 
891 	if (!sk)
892 		return 0;
893 
894 	lock_sock(sk);
895 	if (!sk->sk_shutdown) {
896 		sk->sk_shutdown = SHUTDOWN_MASK;
897 
898 		release_sock(sk);
899 		__rfcomm_sock_close(sk);
900 		lock_sock(sk);
901 
902 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
903 		    !(current->flags & PF_EXITING))
904 			err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
905 	}
906 	release_sock(sk);
907 	return err;
908 }
909 
910 static int rfcomm_sock_release(struct socket *sock)
911 {
912 	struct sock *sk = sock->sk;
913 	int err;
914 
915 	BT_DBG("sock %p, sk %p", sock, sk);
916 
917 	if (!sk)
918 		return 0;
919 
920 	err = rfcomm_sock_shutdown(sock, 2);
921 
922 	sock_orphan(sk);
923 	rfcomm_sock_kill(sk);
924 	return err;
925 }
926 
927 /* ---- RFCOMM core layer callbacks ----
928  *
929  * called under rfcomm_lock()
930  */
931 int rfcomm_connect_ind(struct rfcomm_session *s, u8 channel, struct rfcomm_dlc **d)
932 {
933 	struct sock *sk, *parent;
934 	bdaddr_t src, dst;
935 	int result = 0;
936 
937 	BT_DBG("session %p channel %d", s, channel);
938 
939 	rfcomm_session_getaddr(s, &src, &dst);
940 
941 	/* Check if we have socket listening on channel */
942 	parent = rfcomm_get_sock_by_channel(BT_LISTEN, channel, &src);
943 	if (!parent)
944 		return 0;
945 
946 	lock_sock(parent);
947 
948 	/* Check for backlog size */
949 	if (sk_acceptq_is_full(parent)) {
950 		BT_DBG("backlog full %d", parent->sk_ack_backlog);
951 		goto done;
952 	}
953 
954 	sk = rfcomm_sock_alloc(sock_net(parent), NULL, BTPROTO_RFCOMM, GFP_ATOMIC, 0);
955 	if (!sk)
956 		goto done;
957 
958 	bt_sock_reclassify_lock(sk, BTPROTO_RFCOMM);
959 
960 	rfcomm_sock_init(sk, parent);
961 	bacpy(&rfcomm_pi(sk)->src, &src);
962 	bacpy(&rfcomm_pi(sk)->dst, &dst);
963 	rfcomm_pi(sk)->channel = channel;
964 
965 	sk->sk_state = BT_CONFIG;
966 	bt_accept_enqueue(parent, sk, true);
967 
968 	/* Accept connection and return socket DLC */
969 	*d = rfcomm_pi(sk)->dlc;
970 	result = 1;
971 
972 done:
973 	release_sock(parent);
974 
975 	if (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags))
976 		parent->sk_state_change(parent);
977 
978 	return result;
979 }
980 
981 static int rfcomm_sock_debugfs_show(struct seq_file *f, void *p)
982 {
983 	struct sock *sk;
984 
985 	read_lock(&rfcomm_sk_list.lock);
986 
987 	sk_for_each(sk, &rfcomm_sk_list.head) {
988 		seq_printf(f, "%pMR %pMR %d %d\n",
989 			   &rfcomm_pi(sk)->src, &rfcomm_pi(sk)->dst,
990 			   sk->sk_state, rfcomm_pi(sk)->channel);
991 	}
992 
993 	read_unlock(&rfcomm_sk_list.lock);
994 
995 	return 0;
996 }
997 
998 DEFINE_SHOW_ATTRIBUTE(rfcomm_sock_debugfs);
999 
1000 static struct dentry *rfcomm_sock_debugfs;
1001 
1002 static const struct proto_ops rfcomm_sock_ops = {
1003 	.family		= PF_BLUETOOTH,
1004 	.owner		= THIS_MODULE,
1005 	.release	= rfcomm_sock_release,
1006 	.bind		= rfcomm_sock_bind,
1007 	.connect	= rfcomm_sock_connect,
1008 	.listen		= rfcomm_sock_listen,
1009 	.accept		= rfcomm_sock_accept,
1010 	.getname	= rfcomm_sock_getname,
1011 	.sendmsg	= rfcomm_sock_sendmsg,
1012 	.recvmsg	= rfcomm_sock_recvmsg,
1013 	.shutdown	= rfcomm_sock_shutdown,
1014 	.setsockopt	= rfcomm_sock_setsockopt,
1015 	.getsockopt	= rfcomm_sock_getsockopt,
1016 	.ioctl		= rfcomm_sock_ioctl,
1017 	.gettstamp	= sock_gettstamp,
1018 	.poll		= bt_sock_poll,
1019 	.socketpair	= sock_no_socketpair,
1020 	.mmap		= sock_no_mmap,
1021 #ifdef CONFIG_COMPAT
1022 	.compat_ioctl	= rfcomm_sock_compat_ioctl,
1023 #endif
1024 };
1025 
1026 static const struct net_proto_family rfcomm_sock_family_ops = {
1027 	.family		= PF_BLUETOOTH,
1028 	.owner		= THIS_MODULE,
1029 	.create		= rfcomm_sock_create
1030 };
1031 
1032 int __init rfcomm_init_sockets(void)
1033 {
1034 	int err;
1035 
1036 	BUILD_BUG_ON(sizeof(struct sockaddr_rc) > sizeof(struct sockaddr));
1037 
1038 	err = proto_register(&rfcomm_proto, 0);
1039 	if (err < 0)
1040 		return err;
1041 
1042 	err = bt_sock_register(BTPROTO_RFCOMM, &rfcomm_sock_family_ops);
1043 	if (err < 0) {
1044 		BT_ERR("RFCOMM socket layer registration failed");
1045 		goto error;
1046 	}
1047 
1048 	err = bt_procfs_init(&init_net, "rfcomm", &rfcomm_sk_list, NULL);
1049 	if (err < 0) {
1050 		BT_ERR("Failed to create RFCOMM proc file");
1051 		bt_sock_unregister(BTPROTO_RFCOMM);
1052 		goto error;
1053 	}
1054 
1055 	BT_INFO("RFCOMM socket layer initialized");
1056 
1057 	if (IS_ERR_OR_NULL(bt_debugfs))
1058 		return 0;
1059 
1060 	rfcomm_sock_debugfs = debugfs_create_file("rfcomm", 0444,
1061 						  bt_debugfs, NULL,
1062 						  &rfcomm_sock_debugfs_fops);
1063 
1064 	return 0;
1065 
1066 error:
1067 	proto_unregister(&rfcomm_proto);
1068 	return err;
1069 }
1070 
1071 void __exit rfcomm_cleanup_sockets(void)
1072 {
1073 	bt_procfs_cleanup(&init_net, "rfcomm");
1074 
1075 	debugfs_remove(rfcomm_sock_debugfs);
1076 
1077 	bt_sock_unregister(BTPROTO_RFCOMM);
1078 
1079 	proto_unregister(&rfcomm_proto);
1080 }
1081