xref: /openbmc/linux/net/bluetooth/rfcomm/tty.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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  * $Id: tty.c,v 1.24 2002/10/03 01:54:38 holtmann Exp $
28  */
29 
30 #include <linux/config.h>
31 #include <linux/module.h>
32 
33 #include <linux/tty.h>
34 #include <linux/tty_driver.h>
35 #include <linux/tty_flip.h>
36 
37 #include <linux/slab.h>
38 #include <linux/skbuff.h>
39 
40 #include <net/bluetooth/bluetooth.h>
41 #include <net/bluetooth/rfcomm.h>
42 
43 #ifndef CONFIG_BT_RFCOMM_DEBUG
44 #undef  BT_DBG
45 #define BT_DBG(D...)
46 #endif
47 
48 #define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
49 #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
50 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
51 #define RFCOMM_TTY_MINOR 0
52 
53 static struct tty_driver *rfcomm_tty_driver;
54 
55 struct rfcomm_dev {
56 	struct list_head	list;
57 	atomic_t		refcnt;
58 
59 	char			name[12];
60 	int			id;
61 	unsigned long		flags;
62 	int			opened;
63 	int			err;
64 
65 	bdaddr_t		src;
66 	bdaddr_t		dst;
67 	u8 			channel;
68 
69 	uint 			modem_status;
70 
71 	struct rfcomm_dlc	*dlc;
72 	struct tty_struct	*tty;
73 	wait_queue_head_t       wait;
74 	struct tasklet_struct   wakeup_task;
75 
76 	atomic_t 		wmem_alloc;
77 };
78 
79 static LIST_HEAD(rfcomm_dev_list);
80 static DEFINE_RWLOCK(rfcomm_dev_lock);
81 
82 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
83 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
84 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
85 
86 static void rfcomm_tty_wakeup(unsigned long arg);
87 
88 /* ---- Device functions ---- */
89 static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
90 {
91 	struct rfcomm_dlc *dlc = dev->dlc;
92 
93 	BT_DBG("dev %p dlc %p", dev, dlc);
94 
95 	rfcomm_dlc_lock(dlc);
96 	/* Detach DLC if it's owned by this dev */
97 	if (dlc->owner == dev)
98 		dlc->owner = NULL;
99 	rfcomm_dlc_unlock(dlc);
100 
101 	rfcomm_dlc_put(dlc);
102 
103 	tty_unregister_device(rfcomm_tty_driver, dev->id);
104 
105 	/* Refcount should only hit zero when called from rfcomm_dev_del()
106 	   which will have taken us off the list. Everything else are
107 	   refcounting bugs. */
108 	BUG_ON(!list_empty(&dev->list));
109 
110 	kfree(dev);
111 
112 	/* It's safe to call module_put() here because socket still
113 	   holds reference to this module. */
114 	module_put(THIS_MODULE);
115 }
116 
117 static inline void rfcomm_dev_hold(struct rfcomm_dev *dev)
118 {
119 	atomic_inc(&dev->refcnt);
120 }
121 
122 static inline void rfcomm_dev_put(struct rfcomm_dev *dev)
123 {
124 	/* The reason this isn't actually a race, as you no
125 	   doubt have a little voice screaming at you in your
126 	   head, is that the refcount should never actually
127 	   reach zero unless the device has already been taken
128 	   off the list, in rfcomm_dev_del(). And if that's not
129 	   true, we'll hit the BUG() in rfcomm_dev_destruct()
130 	   anyway. */
131 	if (atomic_dec_and_test(&dev->refcnt))
132 		rfcomm_dev_destruct(dev);
133 }
134 
135 static struct rfcomm_dev *__rfcomm_dev_get(int id)
136 {
137 	struct rfcomm_dev *dev;
138 	struct list_head  *p;
139 
140 	list_for_each(p, &rfcomm_dev_list) {
141 		dev = list_entry(p, struct rfcomm_dev, list);
142 		if (dev->id == id)
143 			return dev;
144 	}
145 
146 	return NULL;
147 }
148 
149 static inline struct rfcomm_dev *rfcomm_dev_get(int id)
150 {
151 	struct rfcomm_dev *dev;
152 
153 	read_lock(&rfcomm_dev_lock);
154 
155 	dev = __rfcomm_dev_get(id);
156 	if (dev)
157 		rfcomm_dev_hold(dev);
158 
159 	read_unlock(&rfcomm_dev_lock);
160 
161 	return dev;
162 }
163 
164 static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
165 {
166 	struct rfcomm_dev *dev;
167 	struct list_head *head = &rfcomm_dev_list, *p;
168 	int err = 0;
169 
170 	BT_DBG("id %d channel %d", req->dev_id, req->channel);
171 
172 	dev = kmalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
173 	if (!dev)
174 		return -ENOMEM;
175 	memset(dev, 0, sizeof(struct rfcomm_dev));
176 
177 	write_lock_bh(&rfcomm_dev_lock);
178 
179 	if (req->dev_id < 0) {
180 		dev->id = 0;
181 
182 		list_for_each(p, &rfcomm_dev_list) {
183 			if (list_entry(p, struct rfcomm_dev, list)->id != dev->id)
184 				break;
185 
186 			dev->id++;
187 			head = p;
188 		}
189 	} else {
190 		dev->id = req->dev_id;
191 
192 		list_for_each(p, &rfcomm_dev_list) {
193 			struct rfcomm_dev *entry = list_entry(p, struct rfcomm_dev, list);
194 
195 			if (entry->id == dev->id) {
196 				err = -EADDRINUSE;
197 				goto out;
198 			}
199 
200 			if (entry->id > dev->id - 1)
201 				break;
202 
203 			head = p;
204 		}
205 	}
206 
207 	if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) {
208 		err = -ENFILE;
209 		goto out;
210 	}
211 
212 	sprintf(dev->name, "rfcomm%d", dev->id);
213 
214 	list_add(&dev->list, head);
215 	atomic_set(&dev->refcnt, 1);
216 
217 	bacpy(&dev->src, &req->src);
218 	bacpy(&dev->dst, &req->dst);
219 	dev->channel = req->channel;
220 
221 	dev->flags = req->flags &
222 		((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
223 
224 	init_waitqueue_head(&dev->wait);
225 	tasklet_init(&dev->wakeup_task, rfcomm_tty_wakeup, (unsigned long) dev);
226 
227 	rfcomm_dlc_lock(dlc);
228 	dlc->data_ready   = rfcomm_dev_data_ready;
229 	dlc->state_change = rfcomm_dev_state_change;
230 	dlc->modem_status = rfcomm_dev_modem_status;
231 
232 	dlc->owner = dev;
233 	dev->dlc   = dlc;
234 	rfcomm_dlc_unlock(dlc);
235 
236 	/* It's safe to call __module_get() here because socket already
237 	   holds reference to this module. */
238 	__module_get(THIS_MODULE);
239 
240 out:
241 	write_unlock_bh(&rfcomm_dev_lock);
242 
243 	if (err) {
244 		kfree(dev);
245 		return err;
246 	}
247 
248 	tty_register_device(rfcomm_tty_driver, dev->id, NULL);
249 
250 	return dev->id;
251 }
252 
253 static void rfcomm_dev_del(struct rfcomm_dev *dev)
254 {
255 	BT_DBG("dev %p", dev);
256 
257 	write_lock_bh(&rfcomm_dev_lock);
258 	list_del_init(&dev->list);
259 	write_unlock_bh(&rfcomm_dev_lock);
260 
261 	rfcomm_dev_put(dev);
262 }
263 
264 /* ---- Send buffer ---- */
265 static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
266 {
267 	/* We can't let it be zero, because we don't get a callback
268 	   when tx_credits becomes nonzero, hence we'd never wake up */
269 	return dlc->mtu * (dlc->tx_credits?:1);
270 }
271 
272 static void rfcomm_wfree(struct sk_buff *skb)
273 {
274 	struct rfcomm_dev *dev = (void *) skb->sk;
275 	atomic_sub(skb->truesize, &dev->wmem_alloc);
276 	if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
277 		tasklet_schedule(&dev->wakeup_task);
278 	rfcomm_dev_put(dev);
279 }
280 
281 static inline void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
282 {
283 	rfcomm_dev_hold(dev);
284 	atomic_add(skb->truesize, &dev->wmem_alloc);
285 	skb->sk = (void *) dev;
286 	skb->destructor = rfcomm_wfree;
287 }
288 
289 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, int priority)
290 {
291 	if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
292 		struct sk_buff *skb = alloc_skb(size, priority);
293 		if (skb) {
294 			rfcomm_set_owner_w(skb, dev);
295 			return skb;
296 		}
297 	}
298 	return NULL;
299 }
300 
301 /* ---- Device IOCTLs ---- */
302 
303 #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
304 
305 static int rfcomm_create_dev(struct sock *sk, void __user *arg)
306 {
307 	struct rfcomm_dev_req req;
308 	struct rfcomm_dlc *dlc;
309 	int id;
310 
311 	if (copy_from_user(&req, arg, sizeof(req)))
312 		return -EFAULT;
313 
314 	BT_DBG("sk %p dev_id %id flags 0x%x", sk, req.dev_id, req.flags);
315 
316 	if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN))
317 		return -EPERM;
318 
319 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
320 		/* Socket must be connected */
321 		if (sk->sk_state != BT_CONNECTED)
322 			return -EBADFD;
323 
324 		dlc = rfcomm_pi(sk)->dlc;
325 		rfcomm_dlc_hold(dlc);
326 	} else {
327 		dlc = rfcomm_dlc_alloc(GFP_KERNEL);
328 		if (!dlc)
329 			return -ENOMEM;
330 	}
331 
332 	id = rfcomm_dev_add(&req, dlc);
333 	if (id < 0) {
334 		rfcomm_dlc_put(dlc);
335 		return id;
336 	}
337 
338 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
339 		/* DLC is now used by device.
340 		 * Socket must be disconnected */
341 		sk->sk_state = BT_CLOSED;
342 	}
343 
344 	return id;
345 }
346 
347 static int rfcomm_release_dev(void __user *arg)
348 {
349 	struct rfcomm_dev_req req;
350 	struct rfcomm_dev *dev;
351 
352 	if (copy_from_user(&req, arg, sizeof(req)))
353 		return -EFAULT;
354 
355 	BT_DBG("dev_id %id flags 0x%x", req.dev_id, req.flags);
356 
357 	if (!(dev = rfcomm_dev_get(req.dev_id)))
358 		return -ENODEV;
359 
360 	if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
361 		rfcomm_dev_put(dev);
362 		return -EPERM;
363 	}
364 
365 	if (req.flags & (1 << RFCOMM_HANGUP_NOW))
366 		rfcomm_dlc_close(dev->dlc, 0);
367 
368 	rfcomm_dev_del(dev);
369 	rfcomm_dev_put(dev);
370 	return 0;
371 }
372 
373 static int rfcomm_get_dev_list(void __user *arg)
374 {
375 	struct rfcomm_dev_list_req *dl;
376 	struct rfcomm_dev_info *di;
377 	struct list_head *p;
378 	int n = 0, size, err;
379 	u16 dev_num;
380 
381 	BT_DBG("");
382 
383 	if (get_user(dev_num, (u16 __user *) arg))
384 		return -EFAULT;
385 
386 	if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di))
387 		return -EINVAL;
388 
389 	size = sizeof(*dl) + dev_num * sizeof(*di);
390 
391 	if (!(dl = kmalloc(size, GFP_KERNEL)))
392 		return -ENOMEM;
393 
394 	di = dl->dev_info;
395 
396 	read_lock_bh(&rfcomm_dev_lock);
397 
398 	list_for_each(p, &rfcomm_dev_list) {
399 		struct rfcomm_dev *dev = list_entry(p, struct rfcomm_dev, list);
400 		(di + n)->id      = dev->id;
401 		(di + n)->flags   = dev->flags;
402 		(di + n)->state   = dev->dlc->state;
403 		(di + n)->channel = dev->channel;
404 		bacpy(&(di + n)->src, &dev->src);
405 		bacpy(&(di + n)->dst, &dev->dst);
406 		if (++n >= dev_num)
407 			break;
408 	}
409 
410 	read_unlock_bh(&rfcomm_dev_lock);
411 
412 	dl->dev_num = n;
413 	size = sizeof(*dl) + n * sizeof(*di);
414 
415 	err = copy_to_user(arg, dl, size);
416 	kfree(dl);
417 
418 	return err ? -EFAULT : 0;
419 }
420 
421 static int rfcomm_get_dev_info(void __user *arg)
422 {
423 	struct rfcomm_dev *dev;
424 	struct rfcomm_dev_info di;
425 	int err = 0;
426 
427 	BT_DBG("");
428 
429 	if (copy_from_user(&di, arg, sizeof(di)))
430 		return -EFAULT;
431 
432 	if (!(dev = rfcomm_dev_get(di.id)))
433 		return -ENODEV;
434 
435 	di.flags   = dev->flags;
436 	di.channel = dev->channel;
437 	di.state   = dev->dlc->state;
438 	bacpy(&di.src, &dev->src);
439 	bacpy(&di.dst, &dev->dst);
440 
441 	if (copy_to_user(arg, &di, sizeof(di)))
442 		err = -EFAULT;
443 
444 	rfcomm_dev_put(dev);
445 	return err;
446 }
447 
448 int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
449 {
450 	BT_DBG("cmd %d arg %p", cmd, arg);
451 
452 	switch (cmd) {
453 	case RFCOMMCREATEDEV:
454 		return rfcomm_create_dev(sk, arg);
455 
456 	case RFCOMMRELEASEDEV:
457 		return rfcomm_release_dev(arg);
458 
459 	case RFCOMMGETDEVLIST:
460 		return rfcomm_get_dev_list(arg);
461 
462 	case RFCOMMGETDEVINFO:
463 		return rfcomm_get_dev_info(arg);
464 	}
465 
466 	return -EINVAL;
467 }
468 
469 /* ---- DLC callbacks ---- */
470 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
471 {
472 	struct rfcomm_dev *dev = dlc->owner;
473 	struct tty_struct *tty;
474 
475 	if (!dev || !(tty = dev->tty)) {
476 		kfree_skb(skb);
477 		return;
478 	}
479 
480 	BT_DBG("dlc %p tty %p len %d", dlc, tty, skb->len);
481 
482 	if (test_bit(TTY_DONT_FLIP, &tty->flags)) {
483 		register int i;
484 		for (i = 0; i < skb->len; i++) {
485 			if (tty->flip.count >= TTY_FLIPBUF_SIZE)
486 				tty_flip_buffer_push(tty);
487 
488 			tty_insert_flip_char(tty, skb->data[i], 0);
489 		}
490 		tty_flip_buffer_push(tty);
491 	} else
492 		tty->ldisc.receive_buf(tty, skb->data, NULL, skb->len);
493 
494 	kfree_skb(skb);
495 }
496 
497 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
498 {
499 	struct rfcomm_dev *dev = dlc->owner;
500 	if (!dev)
501 		return;
502 
503 	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
504 
505 	dev->err = err;
506 	wake_up_interruptible(&dev->wait);
507 
508 	if (dlc->state == BT_CLOSED) {
509 		if (!dev->tty) {
510 			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
511 				rfcomm_dev_hold(dev);
512 				rfcomm_dev_del(dev);
513 
514 				/* We have to drop DLC lock here, otherwise
515 				   rfcomm_dev_put() will dead lock if it's
516 				   the last reference. */
517 				rfcomm_dlc_unlock(dlc);
518 				rfcomm_dev_put(dev);
519 				rfcomm_dlc_lock(dlc);
520 			}
521 		} else
522 			tty_hangup(dev->tty);
523 	}
524 }
525 
526 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
527 {
528 	struct rfcomm_dev *dev = dlc->owner;
529 	if (!dev)
530 		return;
531 
532 	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
533 
534 	dev->modem_status =
535 		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
536 		((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
537 		((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
538 		((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
539 }
540 
541 /* ---- TTY functions ---- */
542 static void rfcomm_tty_wakeup(unsigned long arg)
543 {
544 	struct rfcomm_dev *dev = (void *) arg;
545 	struct tty_struct *tty = dev->tty;
546 	if (!tty)
547 		return;
548 
549 	BT_DBG("dev %p tty %p", dev, tty);
550 
551 	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
552                 (tty->ldisc.write_wakeup)(tty);
553 
554 	wake_up_interruptible(&tty->write_wait);
555 #ifdef SERIAL_HAVE_POLL_WAIT
556 	wake_up_interruptible(&tty->poll_wait);
557 #endif
558 }
559 
560 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
561 {
562 	DECLARE_WAITQUEUE(wait, current);
563 	struct rfcomm_dev *dev;
564 	struct rfcomm_dlc *dlc;
565 	int err, id;
566 
567         id = tty->index;
568 
569 	BT_DBG("tty %p id %d", tty, id);
570 
571 	/* We don't leak this refcount. For reasons which are not entirely
572 	   clear, the TTY layer will call our ->close() method even if the
573 	   open fails. We decrease the refcount there, and decreasing it
574 	   here too would cause breakage. */
575 	dev = rfcomm_dev_get(id);
576 	if (!dev)
577 		return -ENODEV;
578 
579 	BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst), dev->channel, dev->opened);
580 
581 	if (dev->opened++ != 0)
582 		return 0;
583 
584 	dlc = dev->dlc;
585 
586 	/* Attach TTY and open DLC */
587 
588 	rfcomm_dlc_lock(dlc);
589 	tty->driver_data = dev;
590 	dev->tty = tty;
591 	rfcomm_dlc_unlock(dlc);
592 	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
593 
594 	err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
595 	if (err < 0)
596 		return err;
597 
598 	/* Wait for DLC to connect */
599 	add_wait_queue(&dev->wait, &wait);
600 	while (1) {
601 		set_current_state(TASK_INTERRUPTIBLE);
602 
603 		if (dlc->state == BT_CLOSED) {
604 			err = -dev->err;
605 			break;
606 		}
607 
608 		if (dlc->state == BT_CONNECTED)
609 			break;
610 
611 		if (signal_pending(current)) {
612 			err = -EINTR;
613 			break;
614 		}
615 
616 		schedule();
617 	}
618 	set_current_state(TASK_RUNNING);
619 	remove_wait_queue(&dev->wait, &wait);
620 
621 	return err;
622 }
623 
624 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
625 {
626 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
627 	if (!dev)
628 		return;
629 
630 	BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc, dev->opened);
631 
632 	if (--dev->opened == 0) {
633 		/* Close DLC and dettach TTY */
634 		rfcomm_dlc_close(dev->dlc, 0);
635 
636 		clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
637 		tasklet_kill(&dev->wakeup_task);
638 
639 		rfcomm_dlc_lock(dev->dlc);
640 		tty->driver_data = NULL;
641 		dev->tty = NULL;
642 		rfcomm_dlc_unlock(dev->dlc);
643 	}
644 
645 	rfcomm_dev_put(dev);
646 }
647 
648 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
649 {
650 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
651 	struct rfcomm_dlc *dlc = dev->dlc;
652 	struct sk_buff *skb;
653 	int err = 0, sent = 0, size;
654 
655 	BT_DBG("tty %p count %d", tty, count);
656 
657 	while (count) {
658 		size = min_t(uint, count, dlc->mtu);
659 
660 		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
661 
662 		if (!skb)
663 			break;
664 
665 		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
666 
667 		memcpy(skb_put(skb, size), buf + sent, size);
668 
669 		if ((err = rfcomm_dlc_send(dlc, skb)) < 0) {
670 			kfree_skb(skb);
671 			break;
672 		}
673 
674 		sent  += size;
675 		count -= size;
676 	}
677 
678 	return sent ? sent : err;
679 }
680 
681 static int rfcomm_tty_write_room(struct tty_struct *tty)
682 {
683 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
684 	int room;
685 
686 	BT_DBG("tty %p", tty);
687 
688 	room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
689 	if (room < 0)
690 		room = 0;
691 	return room;
692 }
693 
694 static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, unsigned long arg)
695 {
696 	BT_DBG("tty %p cmd 0x%02x", tty, cmd);
697 
698 	switch (cmd) {
699 	case TCGETS:
700 		BT_DBG("TCGETS is not supported");
701 		return -ENOIOCTLCMD;
702 
703 	case TCSETS:
704 		BT_DBG("TCSETS is not supported");
705 		return -ENOIOCTLCMD;
706 
707 	case TIOCMIWAIT:
708 		BT_DBG("TIOCMIWAIT");
709 		break;
710 
711 	case TIOCGICOUNT:
712 		BT_DBG("TIOCGICOUNT");
713 		break;
714 
715 	case TIOCGSERIAL:
716 		BT_ERR("TIOCGSERIAL is not supported");
717 		return -ENOIOCTLCMD;
718 
719 	case TIOCSSERIAL:
720 		BT_ERR("TIOCSSERIAL is not supported");
721 		return -ENOIOCTLCMD;
722 
723 	case TIOCSERGSTRUCT:
724 		BT_ERR("TIOCSERGSTRUCT is not supported");
725 		return -ENOIOCTLCMD;
726 
727 	case TIOCSERGETLSR:
728 		BT_ERR("TIOCSERGETLSR is not supported");
729 		return -ENOIOCTLCMD;
730 
731 	case TIOCSERCONFIG:
732 		BT_ERR("TIOCSERCONFIG is not supported");
733 		return -ENOIOCTLCMD;
734 
735 	default:
736 		return -ENOIOCTLCMD;	/* ioctls which we must ignore */
737 
738 	}
739 
740 	return -ENOIOCTLCMD;
741 }
742 
743 #define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
744 
745 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct termios *old)
746 {
747 	BT_DBG("tty %p", tty);
748 
749 	if ((tty->termios->c_cflag == old->c_cflag) &&
750 		(RELEVANT_IFLAG(tty->termios->c_iflag) == RELEVANT_IFLAG(old->c_iflag)))
751 		return;
752 
753 	/* handle turning off CRTSCTS */
754 	if ((old->c_cflag & CRTSCTS) && !(tty->termios->c_cflag & CRTSCTS)) {
755 		BT_DBG("turning off CRTSCTS");
756 	}
757 }
758 
759 static void rfcomm_tty_throttle(struct tty_struct *tty)
760 {
761 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
762 
763 	BT_DBG("tty %p dev %p", tty, dev);
764 
765 	rfcomm_dlc_throttle(dev->dlc);
766 }
767 
768 static void rfcomm_tty_unthrottle(struct tty_struct *tty)
769 {
770 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
771 
772 	BT_DBG("tty %p dev %p", tty, dev);
773 
774 	rfcomm_dlc_unthrottle(dev->dlc);
775 }
776 
777 static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
778 {
779 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
780 	struct rfcomm_dlc *dlc = dev->dlc;
781 
782 	BT_DBG("tty %p dev %p", tty, dev);
783 
784 	if (skb_queue_len(&dlc->tx_queue))
785 		return dlc->mtu;
786 
787 	return 0;
788 }
789 
790 static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
791 {
792 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
793 	if (!dev)
794 		return;
795 
796 	BT_DBG("tty %p dev %p", tty, dev);
797 
798 	skb_queue_purge(&dev->dlc->tx_queue);
799 
800 	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) && tty->ldisc.write_wakeup)
801 		tty->ldisc.write_wakeup(tty);
802 }
803 
804 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
805 {
806 	BT_DBG("tty %p ch %c", tty, ch);
807 }
808 
809 static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
810 {
811 	BT_DBG("tty %p timeout %d", tty, timeout);
812 }
813 
814 static void rfcomm_tty_hangup(struct tty_struct *tty)
815 {
816 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
817 	if (!dev)
818 		return;
819 
820 	BT_DBG("tty %p dev %p", tty, dev);
821 
822 	rfcomm_tty_flush_buffer(tty);
823 
824 	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags))
825 		rfcomm_dev_del(dev);
826 }
827 
828 static int rfcomm_tty_read_proc(char *buf, char **start, off_t offset, int len, int *eof, void *unused)
829 {
830 	return 0;
831 }
832 
833 static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
834 {
835  	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
836 
837 	BT_DBG("tty %p dev %p", tty, dev);
838 
839  	return dev->modem_status;
840 }
841 
842 static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
843 {
844  	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
845  	struct rfcomm_dlc *dlc = dev->dlc;
846  	u8 v24_sig;
847 
848 	BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
849 
850  	rfcomm_dlc_get_modem_status(dlc, &v24_sig);
851 
852  	if (set & TIOCM_DSR || set & TIOCM_DTR)
853  		v24_sig |= RFCOMM_V24_RTC;
854  	if (set & TIOCM_RTS || set & TIOCM_CTS)
855  		v24_sig |= RFCOMM_V24_RTR;
856  	if (set & TIOCM_RI)
857  		v24_sig |= RFCOMM_V24_IC;
858  	if (set & TIOCM_CD)
859  		v24_sig |= RFCOMM_V24_DV;
860 
861  	if (clear & TIOCM_DSR || clear & TIOCM_DTR)
862  		v24_sig &= ~RFCOMM_V24_RTC;
863  	if (clear & TIOCM_RTS || clear & TIOCM_CTS)
864  		v24_sig &= ~RFCOMM_V24_RTR;
865  	if (clear & TIOCM_RI)
866  		v24_sig &= ~RFCOMM_V24_IC;
867  	if (clear & TIOCM_CD)
868  		v24_sig &= ~RFCOMM_V24_DV;
869 
870  	rfcomm_dlc_set_modem_status(dlc, v24_sig);
871 
872  	return 0;
873 }
874 
875 /* ---- TTY structure ---- */
876 
877 static struct tty_operations rfcomm_ops = {
878 	.open			= rfcomm_tty_open,
879 	.close			= rfcomm_tty_close,
880 	.write			= rfcomm_tty_write,
881 	.write_room		= rfcomm_tty_write_room,
882 	.chars_in_buffer	= rfcomm_tty_chars_in_buffer,
883 	.flush_buffer		= rfcomm_tty_flush_buffer,
884 	.ioctl			= rfcomm_tty_ioctl,
885 	.throttle		= rfcomm_tty_throttle,
886 	.unthrottle		= rfcomm_tty_unthrottle,
887 	.set_termios		= rfcomm_tty_set_termios,
888 	.send_xchar		= rfcomm_tty_send_xchar,
889 	.hangup			= rfcomm_tty_hangup,
890 	.wait_until_sent	= rfcomm_tty_wait_until_sent,
891 	.read_proc		= rfcomm_tty_read_proc,
892 	.tiocmget		= rfcomm_tty_tiocmget,
893 	.tiocmset		= rfcomm_tty_tiocmset,
894 };
895 
896 int rfcomm_init_ttys(void)
897 {
898 	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
899 	if (!rfcomm_tty_driver)
900 		return -1;
901 
902 	rfcomm_tty_driver->owner	= THIS_MODULE;
903 	rfcomm_tty_driver->driver_name	= "rfcomm";
904 	rfcomm_tty_driver->devfs_name	= "bluetooth/rfcomm/";
905 	rfcomm_tty_driver->name		= "rfcomm";
906 	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
907 	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
908 	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
909 	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
910 	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
911 	rfcomm_tty_driver->init_termios	= tty_std_termios;
912 	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL | CLOCAL;
913 	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
914 
915 	if (tty_register_driver(rfcomm_tty_driver)) {
916 		BT_ERR("Can't register RFCOMM TTY driver");
917 		put_tty_driver(rfcomm_tty_driver);
918 		return -1;
919 	}
920 
921 	BT_INFO("RFCOMM TTY layer initialized");
922 
923 	return 0;
924 }
925 
926 void rfcomm_cleanup_ttys(void)
927 {
928 	tty_unregister_driver(rfcomm_tty_driver);
929 	put_tty_driver(rfcomm_tty_driver);
930 }
931