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