xref: /linux/net/bluetooth/rfcomm/tty.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 TTY.
26  */
27 
28 #include <linux/module.h>
29 
30 #include <linux/tty.h>
31 #include <linux/tty_driver.h>
32 #include <linux/tty_flip.h>
33 
34 #include <linux/capability.h>
35 #include <linux/slab.h>
36 #include <linux/skbuff.h>
37 
38 #include <net/bluetooth/bluetooth.h>
39 #include <net/bluetooth/hci_core.h>
40 #include <net/bluetooth/rfcomm.h>
41 
42 #define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
43 #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
44 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
45 #define RFCOMM_TTY_MINOR 0
46 
47 static struct tty_driver *rfcomm_tty_driver;
48 
49 struct rfcomm_dev {
50 	struct list_head	list;
51 	atomic_t		refcnt;
52 
53 	char			name[12];
54 	int			id;
55 	unsigned long		flags;
56 	atomic_t		opened;
57 	int			err;
58 
59 	bdaddr_t		src;
60 	bdaddr_t		dst;
61 	u8 			channel;
62 
63 	uint 			modem_status;
64 
65 	struct rfcomm_dlc	*dlc;
66 	struct tty_struct	*tty;
67 	wait_queue_head_t       wait;
68 	struct tasklet_struct   wakeup_task;
69 
70 	struct device		*tty_dev;
71 
72 	atomic_t 		wmem_alloc;
73 
74 	struct sk_buff_head	pending;
75 };
76 
77 static LIST_HEAD(rfcomm_dev_list);
78 static DEFINE_RWLOCK(rfcomm_dev_lock);
79 
80 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
81 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
82 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
83 
84 static void rfcomm_tty_wakeup(unsigned long arg);
85 
86 /* ---- Device functions ---- */
87 static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
88 {
89 	struct rfcomm_dlc *dlc = dev->dlc;
90 
91 	BT_DBG("dev %p dlc %p", dev, dlc);
92 
93 	/* Refcount should only hit zero when called from rfcomm_dev_del()
94 	   which will have taken us off the list. Everything else are
95 	   refcounting bugs. */
96 	BUG_ON(!list_empty(&dev->list));
97 
98 	rfcomm_dlc_lock(dlc);
99 	/* Detach DLC if it's owned by this dev */
100 	if (dlc->owner == dev)
101 		dlc->owner = NULL;
102 	rfcomm_dlc_unlock(dlc);
103 
104 	rfcomm_dlc_put(dlc);
105 
106 	tty_unregister_device(rfcomm_tty_driver, dev->id);
107 
108 	kfree(dev);
109 
110 	/* It's safe to call module_put() here because socket still
111 	   holds reference to this module. */
112 	module_put(THIS_MODULE);
113 }
114 
115 static inline void rfcomm_dev_hold(struct rfcomm_dev *dev)
116 {
117 	atomic_inc(&dev->refcnt);
118 }
119 
120 static inline void rfcomm_dev_put(struct rfcomm_dev *dev)
121 {
122 	/* The reason this isn't actually a race, as you no
123 	   doubt have a little voice screaming at you in your
124 	   head, is that the refcount should never actually
125 	   reach zero unless the device has already been taken
126 	   off the list, in rfcomm_dev_del(). And if that's not
127 	   true, we'll hit the BUG() in rfcomm_dev_destruct()
128 	   anyway. */
129 	if (atomic_dec_and_test(&dev->refcnt))
130 		rfcomm_dev_destruct(dev);
131 }
132 
133 static struct rfcomm_dev *__rfcomm_dev_get(int id)
134 {
135 	struct rfcomm_dev *dev;
136 	struct list_head  *p;
137 
138 	list_for_each(p, &rfcomm_dev_list) {
139 		dev = list_entry(p, struct rfcomm_dev, list);
140 		if (dev->id == id)
141 			return dev;
142 	}
143 
144 	return NULL;
145 }
146 
147 static inline struct rfcomm_dev *rfcomm_dev_get(int id)
148 {
149 	struct rfcomm_dev *dev;
150 
151 	read_lock(&rfcomm_dev_lock);
152 
153 	dev = __rfcomm_dev_get(id);
154 
155 	if (dev) {
156 		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
157 			dev = NULL;
158 		else
159 			rfcomm_dev_hold(dev);
160 	}
161 
162 	read_unlock(&rfcomm_dev_lock);
163 
164 	return dev;
165 }
166 
167 static struct device *rfcomm_get_device(struct rfcomm_dev *dev)
168 {
169 	struct hci_dev *hdev;
170 	struct hci_conn *conn;
171 
172 	hdev = hci_get_route(&dev->dst, &dev->src);
173 	if (!hdev)
174 		return NULL;
175 
176 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &dev->dst);
177 
178 	hci_dev_put(hdev);
179 
180 	return conn ? &conn->dev : NULL;
181 }
182 
183 static ssize_t show_address(struct device *tty_dev, struct device_attribute *attr, char *buf)
184 {
185 	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
186 	bdaddr_t bdaddr;
187 	baswap(&bdaddr, &dev->dst);
188 	return sprintf(buf, "%s\n", batostr(&bdaddr));
189 }
190 
191 static ssize_t show_channel(struct device *tty_dev, struct device_attribute *attr, char *buf)
192 {
193 	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
194 	return sprintf(buf, "%d\n", dev->channel);
195 }
196 
197 static DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
198 static DEVICE_ATTR(channel, S_IRUGO, show_channel, NULL);
199 
200 static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
201 {
202 	struct rfcomm_dev *dev;
203 	struct list_head *head = &rfcomm_dev_list, *p;
204 	int err = 0;
205 
206 	BT_DBG("id %d channel %d", req->dev_id, req->channel);
207 
208 	dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
209 	if (!dev)
210 		return -ENOMEM;
211 
212 	write_lock_bh(&rfcomm_dev_lock);
213 
214 	if (req->dev_id < 0) {
215 		dev->id = 0;
216 
217 		list_for_each(p, &rfcomm_dev_list) {
218 			if (list_entry(p, struct rfcomm_dev, list)->id != dev->id)
219 				break;
220 
221 			dev->id++;
222 			head = p;
223 		}
224 	} else {
225 		dev->id = req->dev_id;
226 
227 		list_for_each(p, &rfcomm_dev_list) {
228 			struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list);
229 
230 			if (entry->id == dev->id) {
231 				err = -EADDRINUSE;
232 				goto out;
233 			}
234 
235 			if (entry->id > dev->id - 1)
236 				break;
237 
238 			head = p;
239 		}
240 	}
241 
242 	if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) {
243 		err = -ENFILE;
244 		goto out;
245 	}
246 
247 	sprintf(dev->name, "rfcomm%d", dev->id);
248 
249 	list_add(&dev->list, head);
250 	atomic_set(&dev->refcnt, 1);
251 
252 	bacpy(&dev->src, &req->src);
253 	bacpy(&dev->dst, &req->dst);
254 	dev->channel = req->channel;
255 
256 	dev->flags = req->flags &
257 		((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
258 
259 	atomic_set(&dev->opened, 0);
260 
261 	init_waitqueue_head(&dev->wait);
262 	tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev);
263 
264 	skb_queue_head_init(&dev->pending);
265 
266 	rfcomm_dlc_lock(dlc);
267 
268 	if (req->flags & (1 << RFCOMM_REUSE_DLC)) {
269 		struct sock *sk = dlc->owner;
270 		struct sk_buff *skb;
271 
272 		BUG_ON(!sk);
273 
274 		rfcomm_dlc_throttle(dlc);
275 
276 		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
277 			skb_orphan(skb);
278 			skb_queue_tail(&dev->pending, skb);
279 			atomic_sub(skb->len, &sk->sk_rmem_alloc);
280 		}
281 	}
282 
283 	dlc->data_ready   = rfcomm_dev_data_ready;
284 	dlc->state_change = rfcomm_dev_state_change;
285 	dlc->modem_status = rfcomm_dev_modem_status;
286 
287 	dlc->owner = dev;
288 	dev->dlc   = dlc;
289 
290 	rfcomm_dev_modem_status(dlc, dlc->remote_v24_sig);
291 
292 	rfcomm_dlc_unlock(dlc);
293 
294 	/* It's safe to call __module_get() here because socket already
295 	   holds reference to this module. */
296 	__module_get(THIS_MODULE);
297 
298 out:
299 	write_unlock_bh(&rfcomm_dev_lock);
300 
301 	if (err < 0)
302 		goto free;
303 
304 	dev->tty_dev = tty_register_device(rfcomm_tty_driver, dev->id, NULL);
305 
306 	if (IS_ERR(dev->tty_dev)) {
307 		err = PTR_ERR(dev->tty_dev);
308 		list_del(&dev->list);
309 		goto free;
310 	}
311 
312 	dev_set_drvdata(dev->tty_dev, dev);
313 
314 	if (device_create_file(dev->tty_dev, &dev_attr_address) < 0)
315 		BT_ERR("Failed to create address attribute");
316 
317 	if (device_create_file(dev->tty_dev, &dev_attr_channel) < 0)
318 		BT_ERR("Failed to create channel attribute");
319 
320 	return dev->id;
321 
322 free:
323 	kfree(dev);
324 	return err;
325 }
326 
327 static void rfcomm_dev_del(struct rfcomm_dev *dev)
328 {
329 	BT_DBG("dev %p", dev);
330 
331 	BUG_ON(test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags));
332 
333 	if (atomic_read(&dev->opened) > 0)
334 		return;
335 
336 	write_lock_bh(&rfcomm_dev_lock);
337 	list_del_init(&dev->list);
338 	write_unlock_bh(&rfcomm_dev_lock);
339 
340 	rfcomm_dev_put(dev);
341 }
342 
343 /* ---- Send buffer ---- */
344 static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
345 {
346 	/* We can't let it be zero, because we don't get a callback
347 	   when tx_credits becomes nonzero, hence we'd never wake up */
348 	return dlc->mtu * (dlc->tx_credits?:1);
349 }
350 
351 static void rfcomm_wfree(struct sk_buff *skb)
352 {
353 	struct rfcomm_dev *dev = (void *) skb->sk;
354 	atomic_sub(skb->truesize, &dev->wmem_alloc);
355 	if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
356 		tasklet_schedule(&dev->wakeup_task);
357 	rfcomm_dev_put(dev);
358 }
359 
360 static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
361 {
362 	rfcomm_dev_hold(dev);
363 	atomic_add(skb->truesize, &dev->wmem_alloc);
364 	skb->sk = (void *) dev;
365 	skb->destructor = rfcomm_wfree;
366 }
367 
368 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
369 {
370 	if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
371 		struct sk_buff *skb = alloc_skb(size, priority);
372 		if (skb) {
373 			rfcomm_set_owner_w(skb, dev);
374 			return skb;
375 		}
376 	}
377 	return NULL;
378 }
379 
380 /* ---- Device IOCTLs ---- */
381 
382 #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
383 
384 static int rfcomm_create_dev(struct sock *sk, void __user *arg)
385 {
386 	struct rfcomm_dev_req req;
387 	struct rfcomm_dlc *dlc;
388 	int id;
389 
390 	if (copy_from_user(&req, arg, sizeof(req)))
391 		return -EFAULT;
392 
393 	BT_DBG("sk %p dev_id %d flags 0x%x", sk, req.dev_id, req.flags);
394 
395 	if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN))
396 		return -EPERM;
397 
398 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
399 		/* Socket must be connected */
400 		if (sk->sk_state != BT_CONNECTED)
401 			return -EBADFD;
402 
403 		dlc = rfcomm_pi(sk)->dlc;
404 		rfcomm_dlc_hold(dlc);
405 	} else {
406 		dlc = rfcomm_dlc_alloc(GFP_KERNEL);
407 		if (!dlc)
408 			return -ENOMEM;
409 	}
410 
411 	id = rfcomm_dev_add(&req, dlc);
412 	if (id < 0) {
413 		rfcomm_dlc_put(dlc);
414 		return id;
415 	}
416 
417 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
418 		/* DLC is now used by device.
419 		 * Socket must be disconnected */
420 		sk->sk_state = BT_CLOSED;
421 	}
422 
423 	return id;
424 }
425 
426 static int rfcomm_release_dev(void __user *arg)
427 {
428 	struct rfcomm_dev_req req;
429 	struct rfcomm_dev *dev;
430 
431 	if (copy_from_user(&req, arg, sizeof(req)))
432 		return -EFAULT;
433 
434 	BT_DBG("dev_id %d flags 0x%x", req.dev_id, req.flags);
435 
436 	if (!(dev = rfcomm_dev_get(req.dev_id)))
437 		return -ENODEV;
438 
439 	if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
440 		rfcomm_dev_put(dev);
441 		return -EPERM;
442 	}
443 
444 	if (req.flags & (1 << RFCOMM_HANGUP_NOW))
445 		rfcomm_dlc_close(dev->dlc, 0);
446 
447 	/* Shut down TTY synchronously before freeing rfcomm_dev */
448 	if (dev->tty)
449 		tty_vhangup(dev->tty);
450 
451 	if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
452 		rfcomm_dev_del(dev);
453 	rfcomm_dev_put(dev);
454 	return 0;
455 }
456 
457 static int rfcomm_get_dev_list(void __user *arg)
458 {
459 	struct rfcomm_dev_list_req *dl;
460 	struct rfcomm_dev_info *di;
461 	struct list_head *p;
462 	int n = 0, size, err;
463 	u16 dev_num;
464 
465 	BT_DBG("");
466 
467 	if (get_user(dev_num, (u16 __user *) arg))
468 		return -EFAULT;
469 
470 	if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di))
471 		return -EINVAL;
472 
473 	size = sizeof(*dl) + dev_num * sizeof(*di);
474 
475 	if (!(dl = kmalloc(size, GFP_KERNEL)))
476 		return -ENOMEM;
477 
478 	di = dl->dev_info;
479 
480 	read_lock_bh(&rfcomm_dev_lock);
481 
482 	list_for_each(p, &rfcomm_dev_list) {
483 		struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list);
484 		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
485 			continue;
486 		(di + n)->id      = dev->id;
487 		(di + n)->flags   = dev->flags;
488 		(di + n)->state   = dev->dlc->state;
489 		(di + n)->channel = dev->channel;
490 		bacpy(&(di + n)->src, &dev->src);
491 		bacpy(&(di + n)->dst, &dev->dst);
492 		if (++n >= dev_num)
493 			break;
494 	}
495 
496 	read_unlock_bh(&rfcomm_dev_lock);
497 
498 	dl->dev_num = n;
499 	size = sizeof(*dl) + n * sizeof(*di);
500 
501 	err = copy_to_user(arg, dl, size);
502 	kfree(dl);
503 
504 	return err ? -EFAULT : 0;
505 }
506 
507 static int rfcomm_get_dev_info(void __user *arg)
508 {
509 	struct rfcomm_dev *dev;
510 	struct rfcomm_dev_info di;
511 	int err = 0;
512 
513 	BT_DBG("");
514 
515 	if (copy_from_user(&di, arg, sizeof(di)))
516 		return -EFAULT;
517 
518 	if (!(dev = rfcomm_dev_get(di.id)))
519 		return -ENODEV;
520 
521 	di.flags   = dev->flags;
522 	di.channel = dev->channel;
523 	di.state   = dev->dlc->state;
524 	bacpy(&di.src, &dev->src);
525 	bacpy(&di.dst, &dev->dst);
526 
527 	if (copy_to_user(arg, &di, sizeof(di)))
528 		err = -EFAULT;
529 
530 	rfcomm_dev_put(dev);
531 	return err;
532 }
533 
534 int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
535 {
536 	BT_DBG("cmd %d arg %p", cmd, arg);
537 
538 	switch (cmd) {
539 	case RFCOMMCREATEDEV:
540 		return rfcomm_create_dev(sk, arg);
541 
542 	case RFCOMMRELEASEDEV:
543 		return rfcomm_release_dev(arg);
544 
545 	case RFCOMMGETDEVLIST:
546 		return rfcomm_get_dev_list(arg);
547 
548 	case RFCOMMGETDEVINFO:
549 		return rfcomm_get_dev_info(arg);
550 	}
551 
552 	return -EINVAL;
553 }
554 
555 /* ---- DLC callbacks ---- */
556 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
557 {
558 	struct rfcomm_dev *dev = dlc->owner;
559 	struct tty_struct *tty;
560 
561 	if (!dev) {
562 		kfree_skb(skb);
563 		return;
564 	}
565 
566 	if (!(tty = dev->tty) || !skb_queue_empty(&dev->pending)) {
567 		skb_queue_tail(&dev->pending, skb);
568 		return;
569 	}
570 
571 	BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);
572 
573 	tty_insert_flip_string(tty, skb->data, skb->len);
574 	tty_flip_buffer_push(tty);
575 
576 	kfree_skb(skb);
577 }
578 
579 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
580 {
581 	struct rfcomm_dev *dev = dlc->owner;
582 	if (!dev)
583 		return;
584 
585 	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
586 
587 	dev->err = err;
588 	wake_up_interruptible(&dev->wait);
589 
590 	if (dlc->state == BT_CLOSED) {
591 		if (!dev->tty) {
592 			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
593 				/* Drop DLC lock here to avoid deadlock
594 				 * 1. rfcomm_dev_get will take rfcomm_dev_lock
595 				 *    but in rfcomm_dev_add there's lock order:
596 				 *    rfcomm_dev_lock -> dlc lock
597 				 * 2. rfcomm_dev_put will deadlock if it's
598 				 *    the last reference
599 				 */
600 				rfcomm_dlc_unlock(dlc);
601 				if (rfcomm_dev_get(dev->id) == NULL) {
602 					rfcomm_dlc_lock(dlc);
603 					return;
604 				}
605 
606 				rfcomm_dev_del(dev);
607 				rfcomm_dev_put(dev);
608 				rfcomm_dlc_lock(dlc);
609 			}
610 		} else
611 			tty_hangup(dev->tty);
612 	}
613 }
614 
615 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
616 {
617 	struct rfcomm_dev *dev = dlc->owner;
618 	if (!dev)
619 		return;
620 
621 	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
622 
623 	if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV)) {
624 		if (dev->tty && !C_CLOCAL(dev->tty))
625 			tty_hangup(dev->tty);
626 	}
627 
628 	dev->modem_status =
629 		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
630 		((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
631 		((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
632 		((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
633 }
634 
635 /* ---- TTY functions ---- */
636 static void rfcomm_tty_wakeup(unsigned long arg)
637 {
638 	struct rfcomm_dev *dev = (void *) arg;
639 	struct tty_struct *tty = dev->tty;
640 	if (!tty)
641 		return;
642 
643 	BT_DBG("dev %p tty %p", dev, tty);
644 	tty_wakeup(tty);
645 }
646 
647 static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
648 {
649 	struct tty_struct *tty = dev->tty;
650 	struct sk_buff *skb;
651 	int inserted = 0;
652 
653 	if (!tty)
654 		return;
655 
656 	BT_DBG("dev %p tty %p", dev, tty);
657 
658 	rfcomm_dlc_lock(dev->dlc);
659 
660 	while ((skb = skb_dequeue(&dev->pending))) {
661 		inserted += tty_insert_flip_string(tty, skb->data, skb->len);
662 		kfree_skb(skb);
663 	}
664 
665 	rfcomm_dlc_unlock(dev->dlc);
666 
667 	if (inserted > 0)
668 		tty_flip_buffer_push(tty);
669 }
670 
671 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
672 {
673 	DECLARE_WAITQUEUE(wait, current);
674 	struct rfcomm_dev *dev;
675 	struct rfcomm_dlc *dlc;
676 	int err, id;
677 
678 	id = tty->index;
679 
680 	BT_DBG("tty %p id %d", tty, id);
681 
682 	/* We don't leak this refcount. For reasons which are not entirely
683 	   clear, the TTY layer will call our ->close() method even if the
684 	   open fails. We decrease the refcount there, and decreasing it
685 	   here too would cause breakage. */
686 	dev = rfcomm_dev_get(id);
687 	if (!dev)
688 		return -ENODEV;
689 
690 	BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst),
691 				dev->channel, atomic_read(&dev->opened));
692 
693 	if (atomic_inc_return(&dev->opened) > 1)
694 		return 0;
695 
696 	dlc = dev->dlc;
697 
698 	/* Attach TTY and open DLC */
699 
700 	rfcomm_dlc_lock(dlc);
701 	tty->driver_data = dev;
702 	dev->tty = tty;
703 	rfcomm_dlc_unlock(dlc);
704 	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
705 
706 	err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
707 	if (err < 0)
708 		return err;
709 
710 	/* Wait for DLC to connect */
711 	add_wait_queue(&dev->wait, &wait);
712 	while (1) {
713 		set_current_state(TASK_INTERRUPTIBLE);
714 
715 		if (dlc->state == BT_CLOSED) {
716 			err = -dev->err;
717 			break;
718 		}
719 
720 		if (dlc->state == BT_CONNECTED)
721 			break;
722 
723 		if (signal_pending(current)) {
724 			err = -EINTR;
725 			break;
726 		}
727 
728 		schedule();
729 	}
730 	set_current_state(TASK_RUNNING);
731 	remove_wait_queue(&dev->wait, &wait);
732 
733 	if (err == 0)
734 		device_move(dev->tty_dev, rfcomm_get_device(dev),
735 			    DPM_ORDER_DEV_AFTER_PARENT);
736 
737 	rfcomm_tty_copy_pending(dev);
738 
739 	rfcomm_dlc_unthrottle(dev->dlc);
740 
741 	return err;
742 }
743 
744 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
745 {
746 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
747 	if (!dev)
748 		return;
749 
750 	BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
751 						atomic_read(&dev->opened));
752 
753 	if (atomic_dec_and_test(&dev->opened)) {
754 		if (dev->tty_dev->parent)
755 			device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
756 
757 		/* Close DLC and dettach TTY */
758 		rfcomm_dlc_close(dev->dlc, 0);
759 
760 		clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
761 		tasklet_kill(&dev->wakeup_task);
762 
763 		rfcomm_dlc_lock(dev->dlc);
764 		tty->driver_data = NULL;
765 		dev->tty = NULL;
766 		rfcomm_dlc_unlock(dev->dlc);
767 
768 		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags)) {
769 			write_lock_bh(&rfcomm_dev_lock);
770 			list_del_init(&dev->list);
771 			write_unlock_bh(&rfcomm_dev_lock);
772 
773 			rfcomm_dev_put(dev);
774 		}
775 	}
776 
777 	rfcomm_dev_put(dev);
778 }
779 
780 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
781 {
782 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
783 	struct rfcomm_dlc *dlc = dev->dlc;
784 	struct sk_buff *skb;
785 	int err = 0, sent = 0, size;
786 
787 	BT_DBG("tty %p count %d", tty, count);
788 
789 	while (count) {
790 		size = min_t(uint, count, dlc->mtu);
791 
792 		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
793 
794 		if (!skb)
795 			break;
796 
797 		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
798 
799 		memcpy(skb_put(skb, size), buf + sent, size);
800 
801 		if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
802 			kfree_skb(skb);
803 			break;
804 		}
805 
806 		sent  += size;
807 		count -= size;
808 	}
809 
810 	return sent ? sent : err;
811 }
812 
813 static int rfcomm_tty_write_room(struct tty_struct *tty)
814 {
815 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
816 	int room;
817 
818 	BT_DBG("tty %p", tty);
819 
820 	if (!dev || !dev->dlc)
821 		return 0;
822 
823 	room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
824 	if (room < 0)
825 		room = 0;
826 
827 	return room;
828 }
829 
830 static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
831 {
832 	BT_DBG("tty %p cmd 0x%02x", tty, cmd);
833 
834 	switch (cmd) {
835 	case TCGETS:
836 		BT_DBG("TCGETS is not supported");
837 		return -ENOIOCTLCMD;
838 
839 	case TCSETS:
840 		BT_DBG("TCSETS is not supported");
841 		return -ENOIOCTLCMD;
842 
843 	case TIOCMIWAIT:
844 		BT_DBG("TIOCMIWAIT");
845 		break;
846 
847 	case TIOCGICOUNT:
848 		BT_DBG("TIOCGICOUNT");
849 		break;
850 
851 	case TIOCGSERIAL:
852 		BT_ERR("TIOCGSERIAL is not supported");
853 		return -ENOIOCTLCMD;
854 
855 	case TIOCSSERIAL:
856 		BT_ERR("TIOCSSERIAL is not supported");
857 		return -ENOIOCTLCMD;
858 
859 	case TIOCSERGSTRUCT:
860 		BT_ERR("TIOCSERGSTRUCT is not supported");
861 		return -ENOIOCTLCMD;
862 
863 	case TIOCSERGETLSR:
864 		BT_ERR("TIOCSERGETLSR is not supported");
865 		return -ENOIOCTLCMD;
866 
867 	case TIOCSERCONFIG:
868 		BT_ERR("TIOCSERCONFIG is not supported");
869 		return -ENOIOCTLCMD;
870 
871 	default:
872 		return -ENOIOCTLCMD;	/* ioctls which we must ignore */
873 
874 	}
875 
876 	return -ENOIOCTLCMD;
877 }
878 
879 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
880 {
881 	struct ktermios *new = tty->termios;
882 	int old_baud_rate = tty_termios_baud_rate(old);
883 	int new_baud_rate = tty_termios_baud_rate(new);
884 
885 	u8 baud, data_bits, stop_bits, parity, x_on, x_off;
886 	u16 changes = 0;
887 
888 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
889 
890 	BT_DBG("tty %p termios %p", tty, old);
891 
892 	if (!dev || !dev->dlc || !dev->dlc->session)
893 		return;
894 
895 	/* Handle turning off CRTSCTS */
896 	if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS))
897 		BT_DBG("Turning off CRTSCTS unsupported");
898 
899 	/* Parity on/off and when on, odd/even */
900 	if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
901 			((old->c_cflag & PARODD) != (new->c_cflag & PARODD)) ) {
902 		changes |= RFCOMM_RPN_PM_PARITY;
903 		BT_DBG("Parity change detected.");
904 	}
905 
906 	/* Mark and space parity are not supported! */
907 	if (new->c_cflag & PARENB) {
908 		if (new->c_cflag & PARODD) {
909 			BT_DBG("Parity is ODD");
910 			parity = RFCOMM_RPN_PARITY_ODD;
911 		} else {
912 			BT_DBG("Parity is EVEN");
913 			parity = RFCOMM_RPN_PARITY_EVEN;
914 		}
915 	} else {
916 		BT_DBG("Parity is OFF");
917 		parity = RFCOMM_RPN_PARITY_NONE;
918 	}
919 
920 	/* Setting the x_on / x_off characters */
921 	if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
922 		BT_DBG("XOFF custom");
923 		x_on = new->c_cc[VSTOP];
924 		changes |= RFCOMM_RPN_PM_XON;
925 	} else {
926 		BT_DBG("XOFF default");
927 		x_on = RFCOMM_RPN_XON_CHAR;
928 	}
929 
930 	if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
931 		BT_DBG("XON custom");
932 		x_off = new->c_cc[VSTART];
933 		changes |= RFCOMM_RPN_PM_XOFF;
934 	} else {
935 		BT_DBG("XON default");
936 		x_off = RFCOMM_RPN_XOFF_CHAR;
937 	}
938 
939 	/* Handle setting of stop bits */
940 	if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
941 		changes |= RFCOMM_RPN_PM_STOP;
942 
943 	/* POSIX does not support 1.5 stop bits and RFCOMM does not
944 	 * support 2 stop bits. So a request for 2 stop bits gets
945 	 * translated to 1.5 stop bits */
946 	if (new->c_cflag & CSTOPB) {
947 		stop_bits = RFCOMM_RPN_STOP_15;
948 	} else {
949 		stop_bits = RFCOMM_RPN_STOP_1;
950 	}
951 
952 	/* Handle number of data bits [5-8] */
953 	if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
954 		changes |= RFCOMM_RPN_PM_DATA;
955 
956 	switch (new->c_cflag & CSIZE) {
957 	case CS5:
958 		data_bits = RFCOMM_RPN_DATA_5;
959 		break;
960 	case CS6:
961 		data_bits = RFCOMM_RPN_DATA_6;
962 		break;
963 	case CS7:
964 		data_bits = RFCOMM_RPN_DATA_7;
965 		break;
966 	case CS8:
967 		data_bits = RFCOMM_RPN_DATA_8;
968 		break;
969 	default:
970 		data_bits = RFCOMM_RPN_DATA_8;
971 		break;
972 	}
973 
974 	/* Handle baudrate settings */
975 	if (old_baud_rate != new_baud_rate)
976 		changes |= RFCOMM_RPN_PM_BITRATE;
977 
978 	switch (new_baud_rate) {
979 	case 2400:
980 		baud = RFCOMM_RPN_BR_2400;
981 		break;
982 	case 4800:
983 		baud = RFCOMM_RPN_BR_4800;
984 		break;
985 	case 7200:
986 		baud = RFCOMM_RPN_BR_7200;
987 		break;
988 	case 9600:
989 		baud = RFCOMM_RPN_BR_9600;
990 		break;
991 	case 19200:
992 		baud = RFCOMM_RPN_BR_19200;
993 		break;
994 	case 38400:
995 		baud = RFCOMM_RPN_BR_38400;
996 		break;
997 	case 57600:
998 		baud = RFCOMM_RPN_BR_57600;
999 		break;
1000 	case 115200:
1001 		baud = RFCOMM_RPN_BR_115200;
1002 		break;
1003 	case 230400:
1004 		baud = RFCOMM_RPN_BR_230400;
1005 		break;
1006 	default:
1007 		/* 9600 is standard accordinag to the RFCOMM specification */
1008 		baud = RFCOMM_RPN_BR_9600;
1009 		break;
1010 
1011 	}
1012 
1013 	if (changes)
1014 		rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
1015 				data_bits, stop_bits, parity,
1016 				RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
1017 }
1018 
1019 static void rfcomm_tty_throttle(struct tty_struct *tty)
1020 {
1021 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1022 
1023 	BT_DBG("tty %p dev %p", tty, dev);
1024 
1025 	rfcomm_dlc_throttle(dev->dlc);
1026 }
1027 
1028 static void rfcomm_tty_unthrottle(struct tty_struct *tty)
1029 {
1030 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1031 
1032 	BT_DBG("tty %p dev %p", tty, dev);
1033 
1034 	rfcomm_dlc_unthrottle(dev->dlc);
1035 }
1036 
1037 static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
1038 {
1039 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1040 
1041 	BT_DBG("tty %p dev %p", tty, dev);
1042 
1043 	if (!dev || !dev->dlc)
1044 		return 0;
1045 
1046 	if (!skb_queue_empty(&dev->dlc->tx_queue))
1047 		return dev->dlc->mtu;
1048 
1049 	return 0;
1050 }
1051 
1052 static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
1053 {
1054 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1055 
1056 	BT_DBG("tty %p dev %p", tty, dev);
1057 
1058 	if (!dev || !dev->dlc)
1059 		return;
1060 
1061 	skb_queue_purge(&dev->dlc->tx_queue);
1062 	tty_wakeup(tty);
1063 }
1064 
1065 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
1066 {
1067 	BT_DBG("tty %p ch %c", tty, ch);
1068 }
1069 
1070 static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
1071 {
1072 	BT_DBG("tty %p timeout %d", tty, timeout);
1073 }
1074 
1075 static void rfcomm_tty_hangup(struct tty_struct *tty)
1076 {
1077 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1078 
1079 	BT_DBG("tty %p dev %p", tty, dev);
1080 
1081 	if (!dev)
1082 		return;
1083 
1084 	rfcomm_tty_flush_buffer(tty);
1085 
1086 	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
1087 		if (rfcomm_dev_get(dev->id) == NULL)
1088 			return;
1089 		rfcomm_dev_del(dev);
1090 		rfcomm_dev_put(dev);
1091 	}
1092 }
1093 
1094 static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
1095 {
1096 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1097 
1098 	BT_DBG("tty %p dev %p", tty, dev);
1099 
1100 	return dev->modem_status;
1101 }
1102 
1103 static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
1104 {
1105 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1106 	struct rfcomm_dlc *dlc = dev->dlc;
1107 	u8 v24_sig;
1108 
1109 	BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
1110 
1111 	rfcomm_dlc_get_modem_status(dlc, &v24_sig);
1112 
1113 	if (set & TIOCM_DSR || set & TIOCM_DTR)
1114 		v24_sig |= RFCOMM_V24_RTC;
1115 	if (set & TIOCM_RTS || set & TIOCM_CTS)
1116 		v24_sig |= RFCOMM_V24_RTR;
1117 	if (set & TIOCM_RI)
1118 		v24_sig |= RFCOMM_V24_IC;
1119 	if (set & TIOCM_CD)
1120 		v24_sig |= RFCOMM_V24_DV;
1121 
1122 	if (clear & TIOCM_DSR || clear & TIOCM_DTR)
1123 		v24_sig &= ~RFCOMM_V24_RTC;
1124 	if (clear & TIOCM_RTS || clear & TIOCM_CTS)
1125 		v24_sig &= ~RFCOMM_V24_RTR;
1126 	if (clear & TIOCM_RI)
1127 		v24_sig &= ~RFCOMM_V24_IC;
1128 	if (clear & TIOCM_CD)
1129 		v24_sig &= ~RFCOMM_V24_DV;
1130 
1131 	rfcomm_dlc_set_modem_status(dlc, v24_sig);
1132 
1133 	return 0;
1134 }
1135 
1136 /* ---- TTY structure ---- */
1137 
1138 static const struct tty_operations rfcomm_ops = {
1139 	.open			= rfcomm_tty_open,
1140 	.close			= rfcomm_tty_close,
1141 	.write			= rfcomm_tty_write,
1142 	.write_room		= rfcomm_tty_write_room,
1143 	.chars_in_buffer	= rfcomm_tty_chars_in_buffer,
1144 	.flush_buffer		= rfcomm_tty_flush_buffer,
1145 	.ioctl			= rfcomm_tty_ioctl,
1146 	.throttle		= rfcomm_tty_throttle,
1147 	.unthrottle		= rfcomm_tty_unthrottle,
1148 	.set_termios		= rfcomm_tty_set_termios,
1149 	.send_xchar		= rfcomm_tty_send_xchar,
1150 	.hangup			= rfcomm_tty_hangup,
1151 	.wait_until_sent	= rfcomm_tty_wait_until_sent,
1152 	.tiocmget		= rfcomm_tty_tiocmget,
1153 	.tiocmset		= rfcomm_tty_tiocmset,
1154 };
1155 
1156 int __init rfcomm_init_ttys(void)
1157 {
1158 	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
1159 	if (!rfcomm_tty_driver)
1160 		return -1;
1161 
1162 	rfcomm_tty_driver->owner	= THIS_MODULE;
1163 	rfcomm_tty_driver->driver_name	= "rfcomm";
1164 	rfcomm_tty_driver->name		= "rfcomm";
1165 	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
1166 	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
1167 	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
1168 	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
1169 	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1170 	rfcomm_tty_driver->init_termios	= tty_std_termios;
1171 	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1172 	rfcomm_tty_driver->init_termios.c_lflag &= ~ICANON;
1173 	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
1174 
1175 	if (tty_register_driver(rfcomm_tty_driver)) {
1176 		BT_ERR("Can't register RFCOMM TTY driver");
1177 		put_tty_driver(rfcomm_tty_driver);
1178 		return -1;
1179 	}
1180 
1181 	BT_INFO("RFCOMM TTY layer initialized");
1182 
1183 	return 0;
1184 }
1185 
1186 void rfcomm_cleanup_ttys(void)
1187 {
1188 	tty_unregister_driver(rfcomm_tty_driver);
1189 	put_tty_driver(rfcomm_tty_driver);
1190 }
1191