xref: /openbmc/linux/net/bluetooth/rfcomm/tty.c (revision 384740dc)
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 #ifndef CONFIG_BT_RFCOMM_DEBUG
43 #undef  BT_DBG
44 #define BT_DBG(D...)
45 #endif
46 
47 #define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
48 #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
49 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
50 #define RFCOMM_TTY_MINOR 0
51 
52 static struct tty_driver *rfcomm_tty_driver;
53 
54 struct rfcomm_dev {
55 	struct list_head	list;
56 	atomic_t		refcnt;
57 
58 	char			name[12];
59 	int			id;
60 	unsigned long		flags;
61 	int			opened;
62 	int			err;
63 
64 	bdaddr_t		src;
65 	bdaddr_t		dst;
66 	u8 			channel;
67 
68 	uint 			modem_status;
69 
70 	struct rfcomm_dlc	*dlc;
71 	struct tty_struct	*tty;
72 	wait_queue_head_t       wait;
73 	struct tasklet_struct   wakeup_task;
74 
75 	struct device		*tty_dev;
76 
77 	atomic_t 		wmem_alloc;
78 
79 	struct sk_buff_head	pending;
80 };
81 
82 static LIST_HEAD(rfcomm_dev_list);
83 static DEFINE_RWLOCK(rfcomm_dev_lock);
84 
85 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
86 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
87 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
88 
89 static void rfcomm_tty_wakeup(unsigned long arg);
90 
91 /* ---- Device functions ---- */
92 static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
93 {
94 	struct rfcomm_dlc *dlc = dev->dlc;
95 
96 	BT_DBG("dev %p dlc %p", dev, dlc);
97 
98 	/* Refcount should only hit zero when called from rfcomm_dev_del()
99 	   which will have taken us off the list. Everything else are
100 	   refcounting bugs. */
101 	BUG_ON(!list_empty(&dev->list));
102 
103 	rfcomm_dlc_lock(dlc);
104 	/* Detach DLC if it's owned by this dev */
105 	if (dlc->owner == dev)
106 		dlc->owner = NULL;
107 	rfcomm_dlc_unlock(dlc);
108 
109 	rfcomm_dlc_put(dlc);
110 
111 	tty_unregister_device(rfcomm_tty_driver, dev->id);
112 
113 	kfree(dev);
114 
115 	/* It's safe to call module_put() here because socket still
116 	   holds reference to this module. */
117 	module_put(THIS_MODULE);
118 }
119 
120 static inline void rfcomm_dev_hold(struct rfcomm_dev *dev)
121 {
122 	atomic_inc(&dev->refcnt);
123 }
124 
125 static inline void rfcomm_dev_put(struct rfcomm_dev *dev)
126 {
127 	/* The reason this isn't actually a race, as you no
128 	   doubt have a little voice screaming at you in your
129 	   head, is that the refcount should never actually
130 	   reach zero unless the device has already been taken
131 	   off the list, in rfcomm_dev_del(). And if that's not
132 	   true, we'll hit the BUG() in rfcomm_dev_destruct()
133 	   anyway. */
134 	if (atomic_dec_and_test(&dev->refcnt))
135 		rfcomm_dev_destruct(dev);
136 }
137 
138 static struct rfcomm_dev *__rfcomm_dev_get(int id)
139 {
140 	struct rfcomm_dev *dev;
141 	struct list_head  *p;
142 
143 	list_for_each(p, &rfcomm_dev_list) {
144 		dev = list_entry(p, struct rfcomm_dev, list);
145 		if (dev->id == id)
146 			return dev;
147 	}
148 
149 	return NULL;
150 }
151 
152 static inline struct rfcomm_dev *rfcomm_dev_get(int id)
153 {
154 	struct rfcomm_dev *dev;
155 
156 	read_lock(&rfcomm_dev_lock);
157 
158 	dev = __rfcomm_dev_get(id);
159 
160 	if (dev) {
161 		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
162 			dev = NULL;
163 		else
164 			rfcomm_dev_hold(dev);
165 	}
166 
167 	read_unlock(&rfcomm_dev_lock);
168 
169 	return dev;
170 }
171 
172 static struct device *rfcomm_get_device(struct rfcomm_dev *dev)
173 {
174 	struct hci_dev *hdev;
175 	struct hci_conn *conn;
176 
177 	hdev = hci_get_route(&dev->dst, &dev->src);
178 	if (!hdev)
179 		return NULL;
180 
181 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &dev->dst);
182 
183 	hci_dev_put(hdev);
184 
185 	return conn ? &conn->dev : NULL;
186 }
187 
188 static ssize_t show_address(struct device *tty_dev, struct device_attribute *attr, char *buf)
189 {
190 	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
191 	bdaddr_t bdaddr;
192 	baswap(&bdaddr, &dev->dst);
193 	return sprintf(buf, "%s\n", batostr(&bdaddr));
194 }
195 
196 static ssize_t show_channel(struct device *tty_dev, struct device_attribute *attr, char *buf)
197 {
198 	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
199 	return sprintf(buf, "%d\n", dev->channel);
200 }
201 
202 static DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
203 static DEVICE_ATTR(channel, S_IRUGO, show_channel, NULL);
204 
205 static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
206 {
207 	struct rfcomm_dev *dev;
208 	struct list_head *head = &rfcomm_dev_list, *p;
209 	int err = 0;
210 
211 	BT_DBG("id %d channel %d", req->dev_id, req->channel);
212 
213 	dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
214 	if (!dev)
215 		return -ENOMEM;
216 
217 	write_lock_bh(&rfcomm_dev_lock);
218 
219 	if (req->dev_id < 0) {
220 		dev->id = 0;
221 
222 		list_for_each(p, &rfcomm_dev_list) {
223 			if (list_entry(p, struct rfcomm_dev, list)->id != dev->id)
224 				break;
225 
226 			dev->id++;
227 			head = p;
228 		}
229 	} else {
230 		dev->id = req->dev_id;
231 
232 		list_for_each(p, &rfcomm_dev_list) {
233 			struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list);
234 
235 			if (entry->id == dev->id) {
236 				err = -EADDRINUSE;
237 				goto out;
238 			}
239 
240 			if (entry->id > dev->id - 1)
241 				break;
242 
243 			head = p;
244 		}
245 	}
246 
247 	if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) {
248 		err = -ENFILE;
249 		goto out;
250 	}
251 
252 	sprintf(dev->name, "rfcomm%d", dev->id);
253 
254 	list_add(&dev->list, head);
255 	atomic_set(&dev->refcnt, 1);
256 
257 	bacpy(&dev->src, &req->src);
258 	bacpy(&dev->dst, &req->dst);
259 	dev->channel = req->channel;
260 
261 	dev->flags = req->flags &
262 		((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
263 
264 	init_waitqueue_head(&dev->wait);
265 	tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev);
266 
267 	skb_queue_head_init(&dev->pending);
268 
269 	rfcomm_dlc_lock(dlc);
270 
271 	if (req->flags & (1 << RFCOMM_REUSE_DLC)) {
272 		struct sock *sk = dlc->owner;
273 		struct sk_buff *skb;
274 
275 		BUG_ON(!sk);
276 
277 		rfcomm_dlc_throttle(dlc);
278 
279 		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
280 			skb_orphan(skb);
281 			skb_queue_tail(&dev->pending, skb);
282 			atomic_sub(skb->len, &sk->sk_rmem_alloc);
283 		}
284 	}
285 
286 	dlc->data_ready   = rfcomm_dev_data_ready;
287 	dlc->state_change = rfcomm_dev_state_change;
288 	dlc->modem_status = rfcomm_dev_modem_status;
289 
290 	dlc->owner = dev;
291 	dev->dlc   = dlc;
292 
293 	rfcomm_dev_modem_status(dlc, dlc->remote_v24_sig);
294 
295 	rfcomm_dlc_unlock(dlc);
296 
297 	/* It's safe to call __module_get() here because socket already
298 	   holds reference to this module. */
299 	__module_get(THIS_MODULE);
300 
301 out:
302 	write_unlock_bh(&rfcomm_dev_lock);
303 
304 	if (err < 0) {
305 		kfree(dev);
306 		return err;
307 	}
308 
309 	dev->tty_dev = tty_register_device(rfcomm_tty_driver, dev->id, NULL);
310 
311 	if (IS_ERR(dev->tty_dev)) {
312 		err = PTR_ERR(dev->tty_dev);
313 		list_del(&dev->list);
314 		kfree(dev);
315 		return err;
316 	}
317 
318 	dev_set_drvdata(dev->tty_dev, dev);
319 
320 	if (device_create_file(dev->tty_dev, &dev_attr_address) < 0)
321 		BT_ERR("Failed to create address attribute");
322 
323 	if (device_create_file(dev->tty_dev, &dev_attr_channel) < 0)
324 		BT_ERR("Failed to create channel attribute");
325 
326 	return dev->id;
327 }
328 
329 static void rfcomm_dev_del(struct rfcomm_dev *dev)
330 {
331 	BT_DBG("dev %p", dev);
332 
333 	if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
334 		BUG_ON(1);
335 	else
336 		set_bit(RFCOMM_TTY_RELEASED, &dev->flags);
337 
338 	write_lock_bh(&rfcomm_dev_lock);
339 	list_del_init(&dev->list);
340 	write_unlock_bh(&rfcomm_dev_lock);
341 
342 	rfcomm_dev_put(dev);
343 }
344 
345 /* ---- Send buffer ---- */
346 static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
347 {
348 	/* We can't let it be zero, because we don't get a callback
349 	   when tx_credits becomes nonzero, hence we'd never wake up */
350 	return dlc->mtu * (dlc->tx_credits?:1);
351 }
352 
353 static void rfcomm_wfree(struct sk_buff *skb)
354 {
355 	struct rfcomm_dev *dev = (void *) skb->sk;
356 	atomic_sub(skb->truesize, &dev->wmem_alloc);
357 	if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
358 		tasklet_schedule(&dev->wakeup_task);
359 	rfcomm_dev_put(dev);
360 }
361 
362 static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
363 {
364 	rfcomm_dev_hold(dev);
365 	atomic_add(skb->truesize, &dev->wmem_alloc);
366 	skb->sk = (void *) dev;
367 	skb->destructor = rfcomm_wfree;
368 }
369 
370 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
371 {
372 	if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
373 		struct sk_buff *skb = alloc_skb(size, priority);
374 		if (skb) {
375 			rfcomm_set_owner_w(skb, dev);
376 			return skb;
377 		}
378 	}
379 	return NULL;
380 }
381 
382 /* ---- Device IOCTLs ---- */
383 
384 #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
385 
386 static int rfcomm_create_dev(struct sock *sk, void __user *arg)
387 {
388 	struct rfcomm_dev_req req;
389 	struct rfcomm_dlc *dlc;
390 	int id;
391 
392 	if (copy_from_user(&req, arg, sizeof(req)))
393 		return -EFAULT;
394 
395 	BT_DBG("sk %p dev_id %d flags 0x%x", sk, req.dev_id, req.flags);
396 
397 	if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN))
398 		return -EPERM;
399 
400 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
401 		/* Socket must be connected */
402 		if (sk->sk_state != BT_CONNECTED)
403 			return -EBADFD;
404 
405 		dlc = rfcomm_pi(sk)->dlc;
406 		rfcomm_dlc_hold(dlc);
407 	} else {
408 		dlc = rfcomm_dlc_alloc(GFP_KERNEL);
409 		if (!dlc)
410 			return -ENOMEM;
411 	}
412 
413 	id = rfcomm_dev_add(&req, dlc);
414 	if (id < 0) {
415 		rfcomm_dlc_put(dlc);
416 		return id;
417 	}
418 
419 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
420 		/* DLC is now used by device.
421 		 * Socket must be disconnected */
422 		sk->sk_state = BT_CLOSED;
423 	}
424 
425 	return id;
426 }
427 
428 static int rfcomm_release_dev(void __user *arg)
429 {
430 	struct rfcomm_dev_req req;
431 	struct rfcomm_dev *dev;
432 
433 	if (copy_from_user(&req, arg, sizeof(req)))
434 		return -EFAULT;
435 
436 	BT_DBG("dev_id %d flags 0x%x", req.dev_id, req.flags);
437 
438 	if (!(dev = rfcomm_dev_get(req.dev_id)))
439 		return -ENODEV;
440 
441 	if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
442 		rfcomm_dev_put(dev);
443 		return -EPERM;
444 	}
445 
446 	if (req.flags & (1 << RFCOMM_HANGUP_NOW))
447 		rfcomm_dlc_close(dev->dlc, 0);
448 
449 	/* Shut down TTY synchronously before freeing rfcomm_dev */
450 	if (dev->tty)
451 		tty_vhangup(dev->tty);
452 
453 	if (!test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
454 		rfcomm_dev_del(dev);
455 	rfcomm_dev_put(dev);
456 	return 0;
457 }
458 
459 static int rfcomm_get_dev_list(void __user *arg)
460 {
461 	struct rfcomm_dev_list_req *dl;
462 	struct rfcomm_dev_info *di;
463 	struct list_head *p;
464 	int n = 0, size, err;
465 	u16 dev_num;
466 
467 	BT_DBG("");
468 
469 	if (get_user(dev_num, (u16 __user *) arg))
470 		return -EFAULT;
471 
472 	if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di))
473 		return -EINVAL;
474 
475 	size = sizeof(*dl) + dev_num * sizeof(*di);
476 
477 	if (!(dl = kmalloc(size, GFP_KERNEL)))
478 		return -ENOMEM;
479 
480 	di = dl->dev_info;
481 
482 	read_lock_bh(&rfcomm_dev_lock);
483 
484 	list_for_each(p, &rfcomm_dev_list) {
485 		struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list);
486 		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
487 			continue;
488 		(di + n)->id      = dev->id;
489 		(di + n)->flags   = dev->flags;
490 		(di + n)->state   = dev->dlc->state;
491 		(di + n)->channel = dev->channel;
492 		bacpy(&(di + n)->src, &dev->src);
493 		bacpy(&(di + n)->dst, &dev->dst);
494 		if (++n >= dev_num)
495 			break;
496 	}
497 
498 	read_unlock_bh(&rfcomm_dev_lock);
499 
500 	dl->dev_num = n;
501 	size = sizeof(*dl) + n * sizeof(*di);
502 
503 	err = copy_to_user(arg, dl, size);
504 	kfree(dl);
505 
506 	return err ? -EFAULT : 0;
507 }
508 
509 static int rfcomm_get_dev_info(void __user *arg)
510 {
511 	struct rfcomm_dev *dev;
512 	struct rfcomm_dev_info di;
513 	int err = 0;
514 
515 	BT_DBG("");
516 
517 	if (copy_from_user(&di, arg, sizeof(di)))
518 		return -EFAULT;
519 
520 	if (!(dev = rfcomm_dev_get(di.id)))
521 		return -ENODEV;
522 
523 	di.flags   = dev->flags;
524 	di.channel = dev->channel;
525 	di.state   = dev->dlc->state;
526 	bacpy(&di.src, &dev->src);
527 	bacpy(&di.dst, &dev->dst);
528 
529 	if (copy_to_user(arg, &di, sizeof(di)))
530 		err = -EFAULT;
531 
532 	rfcomm_dev_put(dev);
533 	return err;
534 }
535 
536 int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
537 {
538 	BT_DBG("cmd %d arg %p", cmd, arg);
539 
540 	switch (cmd) {
541 	case RFCOMMCREATEDEV:
542 		return rfcomm_create_dev(sk, arg);
543 
544 	case RFCOMMRELEASEDEV:
545 		return rfcomm_release_dev(arg);
546 
547 	case RFCOMMGETDEVLIST:
548 		return rfcomm_get_dev_list(arg);
549 
550 	case RFCOMMGETDEVINFO:
551 		return rfcomm_get_dev_info(arg);
552 	}
553 
554 	return -EINVAL;
555 }
556 
557 /* ---- DLC callbacks ---- */
558 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
559 {
560 	struct rfcomm_dev *dev = dlc->owner;
561 	struct tty_struct *tty;
562 
563 	if (!dev) {
564 		kfree_skb(skb);
565 		return;
566 	}
567 
568 	if (!(tty = dev->tty) || !skb_queue_empty(&dev->pending)) {
569 		skb_queue_tail(&dev->pending, skb);
570 		return;
571 	}
572 
573 	BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);
574 
575 	tty_insert_flip_string(tty, skb->data, skb->len);
576 	tty_flip_buffer_push(tty);
577 
578 	kfree_skb(skb);
579 }
580 
581 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
582 {
583 	struct rfcomm_dev *dev = dlc->owner;
584 	if (!dev)
585 		return;
586 
587 	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
588 
589 	dev->err = err;
590 	wake_up_interruptible(&dev->wait);
591 
592 	if (dlc->state == BT_CLOSED) {
593 		if (!dev->tty) {
594 			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
595 				/* Drop DLC lock here to avoid deadlock
596 				 * 1. rfcomm_dev_get will take rfcomm_dev_lock
597 				 *    but in rfcomm_dev_add there's lock order:
598 				 *    rfcomm_dev_lock -> dlc lock
599 				 * 2. rfcomm_dev_put will deadlock if it's
600 				 *    the last reference
601 				 */
602 				rfcomm_dlc_unlock(dlc);
603 				if (rfcomm_dev_get(dev->id) == NULL) {
604 					rfcomm_dlc_lock(dlc);
605 					return;
606 				}
607 
608 				rfcomm_dev_del(dev);
609 				rfcomm_dev_put(dev);
610 				rfcomm_dlc_lock(dlc);
611 			}
612 		} else
613 			tty_hangup(dev->tty);
614 	}
615 }
616 
617 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
618 {
619 	struct rfcomm_dev *dev = dlc->owner;
620 	if (!dev)
621 		return;
622 
623 	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
624 
625 	if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV)) {
626 		if (dev->tty && !C_CLOCAL(dev->tty))
627 			tty_hangup(dev->tty);
628 	}
629 
630 	dev->modem_status =
631 		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
632 		((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
633 		((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
634 		((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
635 }
636 
637 /* ---- TTY functions ---- */
638 static void rfcomm_tty_wakeup(unsigned long arg)
639 {
640 	struct rfcomm_dev *dev = (void *) arg;
641 	struct tty_struct *tty = dev->tty;
642 	if (!tty)
643 		return;
644 
645 	BT_DBG("dev %p tty %p", dev, tty);
646 	tty_wakeup(tty);
647 }
648 
649 static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
650 {
651 	struct tty_struct *tty = dev->tty;
652 	struct sk_buff *skb;
653 	int inserted = 0;
654 
655 	if (!tty)
656 		return;
657 
658 	BT_DBG("dev %p tty %p", dev, tty);
659 
660 	rfcomm_dlc_lock(dev->dlc);
661 
662 	while ((skb = skb_dequeue(&dev->pending))) {
663 		inserted += tty_insert_flip_string(tty, skb->data, skb->len);
664 		kfree_skb(skb);
665 	}
666 
667 	rfcomm_dlc_unlock(dev->dlc);
668 
669 	if (inserted > 0)
670 		tty_flip_buffer_push(tty);
671 }
672 
673 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
674 {
675 	DECLARE_WAITQUEUE(wait, current);
676 	struct rfcomm_dev *dev;
677 	struct rfcomm_dlc *dlc;
678 	int err, id;
679 
680 	id = tty->index;
681 
682 	BT_DBG("tty %p id %d", tty, id);
683 
684 	/* We don't leak this refcount. For reasons which are not entirely
685 	   clear, the TTY layer will call our ->close() method even if the
686 	   open fails. We decrease the refcount there, and decreasing it
687 	   here too would cause breakage. */
688 	dev = rfcomm_dev_get(id);
689 	if (!dev)
690 		return -ENODEV;
691 
692 	BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst), dev->channel, dev->opened);
693 
694 	if (dev->opened++ != 0)
695 		return 0;
696 
697 	dlc = dev->dlc;
698 
699 	/* Attach TTY and open DLC */
700 
701 	rfcomm_dlc_lock(dlc);
702 	tty->driver_data = dev;
703 	dev->tty = tty;
704 	rfcomm_dlc_unlock(dlc);
705 	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
706 
707 	err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
708 	if (err < 0)
709 		return err;
710 
711 	/* Wait for DLC to connect */
712 	add_wait_queue(&dev->wait, &wait);
713 	while (1) {
714 		set_current_state(TASK_INTERRUPTIBLE);
715 
716 		if (dlc->state == BT_CLOSED) {
717 			err = -dev->err;
718 			break;
719 		}
720 
721 		if (dlc->state == BT_CONNECTED)
722 			break;
723 
724 		if (signal_pending(current)) {
725 			err = -EINTR;
726 			break;
727 		}
728 
729 		schedule();
730 	}
731 	set_current_state(TASK_RUNNING);
732 	remove_wait_queue(&dev->wait, &wait);
733 
734 	if (err == 0)
735 		device_move(dev->tty_dev, rfcomm_get_device(dev));
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, dev->opened);
751 
752 	if (--dev->opened == 0) {
753 		if (dev->tty_dev->parent)
754 			device_move(dev->tty_dev, NULL);
755 
756 		/* Close DLC and dettach TTY */
757 		rfcomm_dlc_close(dev->dlc, 0);
758 
759 		clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
760 		tasklet_kill(&dev->wakeup_task);
761 
762 		rfcomm_dlc_lock(dev->dlc);
763 		tty->driver_data = NULL;
764 		dev->tty = NULL;
765 		rfcomm_dlc_unlock(dev->dlc);
766 	}
767 
768 	rfcomm_dev_put(dev);
769 }
770 
771 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
772 {
773 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
774 	struct rfcomm_dlc *dlc = dev->dlc;
775 	struct sk_buff *skb;
776 	int err = 0, sent = 0, size;
777 
778 	BT_DBG("tty %p count %d", tty, count);
779 
780 	while (count) {
781 		size = min_t(uint, count, dlc->mtu);
782 
783 		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
784 
785 		if (!skb)
786 			break;
787 
788 		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
789 
790 		memcpy(skb_put(skb, size), buf + sent, size);
791 
792 		if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
793 			kfree_skb(skb);
794 			break;
795 		}
796 
797 		sent  += size;
798 		count -= size;
799 	}
800 
801 	return sent ? sent : err;
802 }
803 
804 static int rfcomm_tty_write_room(struct tty_struct *tty)
805 {
806 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
807 	int room;
808 
809 	BT_DBG("tty %p", tty);
810 
811 	if (!dev || !dev->dlc)
812 		return 0;
813 
814 	room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
815 	if (room < 0)
816 		room = 0;
817 
818 	return room;
819 }
820 
821 static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
822 {
823 	BT_DBG("tty %p cmd 0x%02x", tty, cmd);
824 
825 	switch (cmd) {
826 	case TCGETS:
827 		BT_DBG("TCGETS is not supported");
828 		return -ENOIOCTLCMD;
829 
830 	case TCSETS:
831 		BT_DBG("TCSETS is not supported");
832 		return -ENOIOCTLCMD;
833 
834 	case TIOCMIWAIT:
835 		BT_DBG("TIOCMIWAIT");
836 		break;
837 
838 	case TIOCGICOUNT:
839 		BT_DBG("TIOCGICOUNT");
840 		break;
841 
842 	case TIOCGSERIAL:
843 		BT_ERR("TIOCGSERIAL is not supported");
844 		return -ENOIOCTLCMD;
845 
846 	case TIOCSSERIAL:
847 		BT_ERR("TIOCSSERIAL is not supported");
848 		return -ENOIOCTLCMD;
849 
850 	case TIOCSERGSTRUCT:
851 		BT_ERR("TIOCSERGSTRUCT is not supported");
852 		return -ENOIOCTLCMD;
853 
854 	case TIOCSERGETLSR:
855 		BT_ERR("TIOCSERGETLSR is not supported");
856 		return -ENOIOCTLCMD;
857 
858 	case TIOCSERCONFIG:
859 		BT_ERR("TIOCSERCONFIG is not supported");
860 		return -ENOIOCTLCMD;
861 
862 	default:
863 		return -ENOIOCTLCMD;	/* ioctls which we must ignore */
864 
865 	}
866 
867 	return -ENOIOCTLCMD;
868 }
869 
870 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
871 {
872 	struct ktermios *new = tty->termios;
873 	int old_baud_rate = tty_termios_baud_rate(old);
874 	int new_baud_rate = tty_termios_baud_rate(new);
875 
876 	u8 baud, data_bits, stop_bits, parity, x_on, x_off;
877 	u16 changes = 0;
878 
879 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
880 
881 	BT_DBG("tty %p termios %p", tty, old);
882 
883 	if (!dev || !dev->dlc || !dev->dlc->session)
884 		return;
885 
886 	/* Handle turning off CRTSCTS */
887 	if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS))
888 		BT_DBG("Turning off CRTSCTS unsupported");
889 
890 	/* Parity on/off and when on, odd/even */
891 	if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
892 			((old->c_cflag & PARODD) != (new->c_cflag & PARODD)) ) {
893 		changes |= RFCOMM_RPN_PM_PARITY;
894 		BT_DBG("Parity change detected.");
895 	}
896 
897 	/* Mark and space parity are not supported! */
898 	if (new->c_cflag & PARENB) {
899 		if (new->c_cflag & PARODD) {
900 			BT_DBG("Parity is ODD");
901 			parity = RFCOMM_RPN_PARITY_ODD;
902 		} else {
903 			BT_DBG("Parity is EVEN");
904 			parity = RFCOMM_RPN_PARITY_EVEN;
905 		}
906 	} else {
907 		BT_DBG("Parity is OFF");
908 		parity = RFCOMM_RPN_PARITY_NONE;
909 	}
910 
911 	/* Setting the x_on / x_off characters */
912 	if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
913 		BT_DBG("XOFF custom");
914 		x_on = new->c_cc[VSTOP];
915 		changes |= RFCOMM_RPN_PM_XON;
916 	} else {
917 		BT_DBG("XOFF default");
918 		x_on = RFCOMM_RPN_XON_CHAR;
919 	}
920 
921 	if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
922 		BT_DBG("XON custom");
923 		x_off = new->c_cc[VSTART];
924 		changes |= RFCOMM_RPN_PM_XOFF;
925 	} else {
926 		BT_DBG("XON default");
927 		x_off = RFCOMM_RPN_XOFF_CHAR;
928 	}
929 
930 	/* Handle setting of stop bits */
931 	if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
932 		changes |= RFCOMM_RPN_PM_STOP;
933 
934 	/* POSIX does not support 1.5 stop bits and RFCOMM does not
935 	 * support 2 stop bits. So a request for 2 stop bits gets
936 	 * translated to 1.5 stop bits */
937 	if (new->c_cflag & CSTOPB) {
938 		stop_bits = RFCOMM_RPN_STOP_15;
939 	} else {
940 		stop_bits = RFCOMM_RPN_STOP_1;
941 	}
942 
943 	/* Handle number of data bits [5-8] */
944 	if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
945 		changes |= RFCOMM_RPN_PM_DATA;
946 
947 	switch (new->c_cflag & CSIZE) {
948 	case CS5:
949 		data_bits = RFCOMM_RPN_DATA_5;
950 		break;
951 	case CS6:
952 		data_bits = RFCOMM_RPN_DATA_6;
953 		break;
954 	case CS7:
955 		data_bits = RFCOMM_RPN_DATA_7;
956 		break;
957 	case CS8:
958 		data_bits = RFCOMM_RPN_DATA_8;
959 		break;
960 	default:
961 		data_bits = RFCOMM_RPN_DATA_8;
962 		break;
963 	}
964 
965 	/* Handle baudrate settings */
966 	if (old_baud_rate != new_baud_rate)
967 		changes |= RFCOMM_RPN_PM_BITRATE;
968 
969 	switch (new_baud_rate) {
970 	case 2400:
971 		baud = RFCOMM_RPN_BR_2400;
972 		break;
973 	case 4800:
974 		baud = RFCOMM_RPN_BR_4800;
975 		break;
976 	case 7200:
977 		baud = RFCOMM_RPN_BR_7200;
978 		break;
979 	case 9600:
980 		baud = RFCOMM_RPN_BR_9600;
981 		break;
982 	case 19200:
983 		baud = RFCOMM_RPN_BR_19200;
984 		break;
985 	case 38400:
986 		baud = RFCOMM_RPN_BR_38400;
987 		break;
988 	case 57600:
989 		baud = RFCOMM_RPN_BR_57600;
990 		break;
991 	case 115200:
992 		baud = RFCOMM_RPN_BR_115200;
993 		break;
994 	case 230400:
995 		baud = RFCOMM_RPN_BR_230400;
996 		break;
997 	default:
998 		/* 9600 is standard accordinag to the RFCOMM specification */
999 		baud = RFCOMM_RPN_BR_9600;
1000 		break;
1001 
1002 	}
1003 
1004 	if (changes)
1005 		rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
1006 				data_bits, stop_bits, parity,
1007 				RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
1008 
1009 	return;
1010 }
1011 
1012 static void rfcomm_tty_throttle(struct tty_struct *tty)
1013 {
1014 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1015 
1016 	BT_DBG("tty %p dev %p", tty, dev);
1017 
1018 	rfcomm_dlc_throttle(dev->dlc);
1019 }
1020 
1021 static void rfcomm_tty_unthrottle(struct tty_struct *tty)
1022 {
1023 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1024 
1025 	BT_DBG("tty %p dev %p", tty, dev);
1026 
1027 	rfcomm_dlc_unthrottle(dev->dlc);
1028 }
1029 
1030 static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
1031 {
1032 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1033 
1034 	BT_DBG("tty %p dev %p", tty, dev);
1035 
1036 	if (!dev || !dev->dlc)
1037 		return 0;
1038 
1039 	if (!skb_queue_empty(&dev->dlc->tx_queue))
1040 		return dev->dlc->mtu;
1041 
1042 	return 0;
1043 }
1044 
1045 static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
1046 {
1047 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1048 
1049 	BT_DBG("tty %p dev %p", tty, dev);
1050 
1051 	if (!dev || !dev->dlc)
1052 		return;
1053 
1054 	skb_queue_purge(&dev->dlc->tx_queue);
1055 	tty_wakeup(tty);
1056 }
1057 
1058 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
1059 {
1060 	BT_DBG("tty %p ch %c", tty, ch);
1061 }
1062 
1063 static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
1064 {
1065 	BT_DBG("tty %p timeout %d", tty, timeout);
1066 }
1067 
1068 static void rfcomm_tty_hangup(struct tty_struct *tty)
1069 {
1070 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1071 
1072 	BT_DBG("tty %p dev %p", tty, dev);
1073 
1074 	if (!dev)
1075 		return;
1076 
1077 	rfcomm_tty_flush_buffer(tty);
1078 
1079 	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
1080 		if (rfcomm_dev_get(dev->id) == NULL)
1081 			return;
1082 		rfcomm_dev_del(dev);
1083 		rfcomm_dev_put(dev);
1084 	}
1085 }
1086 
1087 static int rfcomm_tty_read_proc(char *buf, char **start, off_t offset, int len, int *eof, void *unused)
1088 {
1089 	return 0;
1090 }
1091 
1092 static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
1093 {
1094 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1095 
1096 	BT_DBG("tty %p dev %p", tty, dev);
1097 
1098 	return dev->modem_status;
1099 }
1100 
1101 static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
1102 {
1103 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1104 	struct rfcomm_dlc *dlc = dev->dlc;
1105 	u8 v24_sig;
1106 
1107 	BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
1108 
1109 	rfcomm_dlc_get_modem_status(dlc, &v24_sig);
1110 
1111 	if (set & TIOCM_DSR || set & TIOCM_DTR)
1112 		v24_sig |= RFCOMM_V24_RTC;
1113 	if (set & TIOCM_RTS || set & TIOCM_CTS)
1114 		v24_sig |= RFCOMM_V24_RTR;
1115 	if (set & TIOCM_RI)
1116 		v24_sig |= RFCOMM_V24_IC;
1117 	if (set & TIOCM_CD)
1118 		v24_sig |= RFCOMM_V24_DV;
1119 
1120 	if (clear & TIOCM_DSR || clear & TIOCM_DTR)
1121 		v24_sig &= ~RFCOMM_V24_RTC;
1122 	if (clear & TIOCM_RTS || clear & TIOCM_CTS)
1123 		v24_sig &= ~RFCOMM_V24_RTR;
1124 	if (clear & TIOCM_RI)
1125 		v24_sig &= ~RFCOMM_V24_IC;
1126 	if (clear & TIOCM_CD)
1127 		v24_sig &= ~RFCOMM_V24_DV;
1128 
1129 	rfcomm_dlc_set_modem_status(dlc, v24_sig);
1130 
1131 	return 0;
1132 }
1133 
1134 /* ---- TTY structure ---- */
1135 
1136 static const struct tty_operations rfcomm_ops = {
1137 	.open			= rfcomm_tty_open,
1138 	.close			= rfcomm_tty_close,
1139 	.write			= rfcomm_tty_write,
1140 	.write_room		= rfcomm_tty_write_room,
1141 	.chars_in_buffer	= rfcomm_tty_chars_in_buffer,
1142 	.flush_buffer		= rfcomm_tty_flush_buffer,
1143 	.ioctl			= rfcomm_tty_ioctl,
1144 	.throttle		= rfcomm_tty_throttle,
1145 	.unthrottle		= rfcomm_tty_unthrottle,
1146 	.set_termios		= rfcomm_tty_set_termios,
1147 	.send_xchar		= rfcomm_tty_send_xchar,
1148 	.hangup			= rfcomm_tty_hangup,
1149 	.wait_until_sent	= rfcomm_tty_wait_until_sent,
1150 	.read_proc		= rfcomm_tty_read_proc,
1151 	.tiocmget		= rfcomm_tty_tiocmget,
1152 	.tiocmset		= rfcomm_tty_tiocmset,
1153 };
1154 
1155 int rfcomm_init_ttys(void)
1156 {
1157 	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
1158 	if (!rfcomm_tty_driver)
1159 		return -1;
1160 
1161 	rfcomm_tty_driver->owner	= THIS_MODULE;
1162 	rfcomm_tty_driver->driver_name	= "rfcomm";
1163 	rfcomm_tty_driver->name		= "rfcomm";
1164 	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
1165 	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
1166 	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
1167 	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
1168 	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1169 	rfcomm_tty_driver->init_termios	= tty_std_termios;
1170 	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1171 	rfcomm_tty_driver->init_termios.c_lflag &= ~ICANON;
1172 	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
1173 
1174 	if (tty_register_driver(rfcomm_tty_driver)) {
1175 		BT_ERR("Can't register RFCOMM TTY driver");
1176 		put_tty_driver(rfcomm_tty_driver);
1177 		return -1;
1178 	}
1179 
1180 	BT_INFO("RFCOMM TTY layer initialized");
1181 
1182 	return 0;
1183 }
1184 
1185 void rfcomm_cleanup_ttys(void)
1186 {
1187 	tty_unregister_driver(rfcomm_tty_driver);
1188 	put_tty_driver(rfcomm_tty_driver);
1189 }
1190