xref: /openbmc/linux/net/bluetooth/rfcomm/tty.c (revision b34081f1)
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 <net/bluetooth/bluetooth.h>
35 #include <net/bluetooth/hci_core.h>
36 #include <net/bluetooth/rfcomm.h>
37 
38 #define RFCOMM_TTY_MAGIC 0x6d02		/* magic number for rfcomm struct */
39 #define RFCOMM_TTY_PORTS RFCOMM_MAX_DEV	/* whole lotta rfcomm devices */
40 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
41 #define RFCOMM_TTY_MINOR 0
42 
43 static struct tty_driver *rfcomm_tty_driver;
44 
45 struct rfcomm_dev {
46 	struct tty_port		port;
47 	struct list_head	list;
48 
49 	char			name[12];
50 	int			id;
51 	unsigned long		flags;
52 	int			err;
53 
54 	bdaddr_t		src;
55 	bdaddr_t		dst;
56 	u8			channel;
57 
58 	uint			modem_status;
59 
60 	struct rfcomm_dlc	*dlc;
61 
62 	struct device		*tty_dev;
63 
64 	atomic_t		wmem_alloc;
65 
66 	struct sk_buff_head	pending;
67 };
68 
69 static LIST_HEAD(rfcomm_dev_list);
70 static DEFINE_SPINLOCK(rfcomm_dev_lock);
71 
72 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb);
73 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err);
74 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig);
75 
76 /* ---- Device functions ---- */
77 
78 static void rfcomm_dev_destruct(struct tty_port *port)
79 {
80 	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
81 	struct rfcomm_dlc *dlc = dev->dlc;
82 
83 	BT_DBG("dev %p dlc %p", dev, dlc);
84 
85 	spin_lock(&rfcomm_dev_lock);
86 	list_del(&dev->list);
87 	spin_unlock(&rfcomm_dev_lock);
88 
89 	rfcomm_dlc_lock(dlc);
90 	/* Detach DLC if it's owned by this dev */
91 	if (dlc->owner == dev)
92 		dlc->owner = NULL;
93 	rfcomm_dlc_unlock(dlc);
94 
95 	rfcomm_dlc_put(dlc);
96 
97 	tty_unregister_device(rfcomm_tty_driver, dev->id);
98 
99 	kfree(dev);
100 
101 	/* It's safe to call module_put() here because socket still
102 	   holds reference to this module. */
103 	module_put(THIS_MODULE);
104 }
105 
106 /* device-specific initialization: open the dlc */
107 static int rfcomm_dev_activate(struct tty_port *port, struct tty_struct *tty)
108 {
109 	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
110 
111 	return rfcomm_dlc_open(dev->dlc, &dev->src, &dev->dst, dev->channel);
112 }
113 
114 /* we block the open until the dlc->state becomes BT_CONNECTED */
115 static int rfcomm_dev_carrier_raised(struct tty_port *port)
116 {
117 	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
118 
119 	return (dev->dlc->state == BT_CONNECTED);
120 }
121 
122 /* device-specific cleanup: close the dlc */
123 static void rfcomm_dev_shutdown(struct tty_port *port)
124 {
125 	struct rfcomm_dev *dev = container_of(port, struct rfcomm_dev, port);
126 
127 	if (dev->tty_dev->parent)
128 		device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
129 
130 	/* close the dlc */
131 	rfcomm_dlc_close(dev->dlc, 0);
132 }
133 
134 static const struct tty_port_operations rfcomm_port_ops = {
135 	.destruct = rfcomm_dev_destruct,
136 	.activate = rfcomm_dev_activate,
137 	.shutdown = rfcomm_dev_shutdown,
138 	.carrier_raised = rfcomm_dev_carrier_raised,
139 };
140 
141 static struct rfcomm_dev *__rfcomm_dev_get(int id)
142 {
143 	struct rfcomm_dev *dev;
144 
145 	list_for_each_entry(dev, &rfcomm_dev_list, list)
146 		if (dev->id == id)
147 			return dev;
148 
149 	return NULL;
150 }
151 
152 static struct rfcomm_dev *rfcomm_dev_get(int id)
153 {
154 	struct rfcomm_dev *dev;
155 
156 	spin_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 			tty_port_get(&dev->port);
165 	}
166 
167 	spin_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 	return sprintf(buf, "%pMR\n", &dev->dst);
192 }
193 
194 static ssize_t show_channel(struct device *tty_dev, struct device_attribute *attr, char *buf)
195 {
196 	struct rfcomm_dev *dev = dev_get_drvdata(tty_dev);
197 	return sprintf(buf, "%d\n", dev->channel);
198 }
199 
200 static DEVICE_ATTR(address, S_IRUGO, show_address, NULL);
201 static DEVICE_ATTR(channel, S_IRUGO, show_channel, NULL);
202 
203 static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
204 {
205 	struct rfcomm_dev *dev, *entry;
206 	struct list_head *head = &rfcomm_dev_list;
207 	int err = 0;
208 
209 	BT_DBG("id %d channel %d", req->dev_id, req->channel);
210 
211 	dev = kzalloc(sizeof(struct rfcomm_dev), GFP_KERNEL);
212 	if (!dev)
213 		return -ENOMEM;
214 
215 	spin_lock(&rfcomm_dev_lock);
216 
217 	if (req->dev_id < 0) {
218 		dev->id = 0;
219 
220 		list_for_each_entry(entry, &rfcomm_dev_list, list) {
221 			if (entry->id != dev->id)
222 				break;
223 
224 			dev->id++;
225 			head = &entry->list;
226 		}
227 	} else {
228 		dev->id = req->dev_id;
229 
230 		list_for_each_entry(entry, &rfcomm_dev_list, list) {
231 			if (entry->id == dev->id) {
232 				err = -EADDRINUSE;
233 				goto out;
234 			}
235 
236 			if (entry->id > dev->id - 1)
237 				break;
238 
239 			head = &entry->list;
240 		}
241 	}
242 
243 	if ((dev->id < 0) || (dev->id > RFCOMM_MAX_DEV - 1)) {
244 		err = -ENFILE;
245 		goto out;
246 	}
247 
248 	sprintf(dev->name, "rfcomm%d", dev->id);
249 
250 	list_add(&dev->list, head);
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 	tty_port_init(&dev->port);
260 	dev->port.ops = &rfcomm_port_ops;
261 
262 	skb_queue_head_init(&dev->pending);
263 
264 	rfcomm_dlc_lock(dlc);
265 
266 	if (req->flags & (1 << RFCOMM_REUSE_DLC)) {
267 		struct sock *sk = dlc->owner;
268 		struct sk_buff *skb;
269 
270 		BUG_ON(!sk);
271 
272 		rfcomm_dlc_throttle(dlc);
273 
274 		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
275 			skb_orphan(skb);
276 			skb_queue_tail(&dev->pending, skb);
277 			atomic_sub(skb->len, &sk->sk_rmem_alloc);
278 		}
279 	}
280 
281 	dlc->data_ready   = rfcomm_dev_data_ready;
282 	dlc->state_change = rfcomm_dev_state_change;
283 	dlc->modem_status = rfcomm_dev_modem_status;
284 
285 	dlc->owner = dev;
286 	dev->dlc   = dlc;
287 
288 	rfcomm_dev_modem_status(dlc, dlc->remote_v24_sig);
289 
290 	rfcomm_dlc_unlock(dlc);
291 
292 	/* It's safe to call __module_get() here because socket already
293 	   holds reference to this module. */
294 	__module_get(THIS_MODULE);
295 
296 out:
297 	spin_unlock(&rfcomm_dev_lock);
298 
299 	if (err < 0)
300 		goto free;
301 
302 	dev->tty_dev = tty_port_register_device(&dev->port, rfcomm_tty_driver,
303 			dev->id, NULL);
304 	if (IS_ERR(dev->tty_dev)) {
305 		err = PTR_ERR(dev->tty_dev);
306 		spin_lock(&rfcomm_dev_lock);
307 		list_del(&dev->list);
308 		spin_unlock(&rfcomm_dev_lock);
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 /* ---- Send buffer ---- */
328 static inline unsigned int rfcomm_room(struct rfcomm_dlc *dlc)
329 {
330 	/* We can't let it be zero, because we don't get a callback
331 	   when tx_credits becomes nonzero, hence we'd never wake up */
332 	return dlc->mtu * (dlc->tx_credits?:1);
333 }
334 
335 static void rfcomm_wfree(struct sk_buff *skb)
336 {
337 	struct rfcomm_dev *dev = (void *) skb->sk;
338 	atomic_sub(skb->truesize, &dev->wmem_alloc);
339 	if (test_bit(RFCOMM_TTY_ATTACHED, &dev->flags))
340 		tty_port_tty_wakeup(&dev->port);
341 	tty_port_put(&dev->port);
342 }
343 
344 static void rfcomm_set_owner_w(struct sk_buff *skb, struct rfcomm_dev *dev)
345 {
346 	tty_port_get(&dev->port);
347 	atomic_add(skb->truesize, &dev->wmem_alloc);
348 	skb->sk = (void *) dev;
349 	skb->destructor = rfcomm_wfree;
350 }
351 
352 static struct sk_buff *rfcomm_wmalloc(struct rfcomm_dev *dev, unsigned long size, gfp_t priority)
353 {
354 	if (atomic_read(&dev->wmem_alloc) < rfcomm_room(dev->dlc)) {
355 		struct sk_buff *skb = alloc_skb(size, priority);
356 		if (skb) {
357 			rfcomm_set_owner_w(skb, dev);
358 			return skb;
359 		}
360 	}
361 	return NULL;
362 }
363 
364 /* ---- Device IOCTLs ---- */
365 
366 #define NOCAP_FLAGS ((1 << RFCOMM_REUSE_DLC) | (1 << RFCOMM_RELEASE_ONHUP))
367 
368 static int rfcomm_create_dev(struct sock *sk, void __user *arg)
369 {
370 	struct rfcomm_dev_req req;
371 	struct rfcomm_dlc *dlc;
372 	int id;
373 
374 	if (copy_from_user(&req, arg, sizeof(req)))
375 		return -EFAULT;
376 
377 	BT_DBG("sk %p dev_id %d flags 0x%x", sk, req.dev_id, req.flags);
378 
379 	if (req.flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN))
380 		return -EPERM;
381 
382 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
383 		/* Socket must be connected */
384 		if (sk->sk_state != BT_CONNECTED)
385 			return -EBADFD;
386 
387 		dlc = rfcomm_pi(sk)->dlc;
388 		rfcomm_dlc_hold(dlc);
389 	} else {
390 		dlc = rfcomm_dlc_alloc(GFP_KERNEL);
391 		if (!dlc)
392 			return -ENOMEM;
393 	}
394 
395 	id = rfcomm_dev_add(&req, dlc);
396 	if (id < 0) {
397 		rfcomm_dlc_put(dlc);
398 		return id;
399 	}
400 
401 	if (req.flags & (1 << RFCOMM_REUSE_DLC)) {
402 		/* DLC is now used by device.
403 		 * Socket must be disconnected */
404 		sk->sk_state = BT_CLOSED;
405 	}
406 
407 	return id;
408 }
409 
410 static int rfcomm_release_dev(void __user *arg)
411 {
412 	struct rfcomm_dev_req req;
413 	struct rfcomm_dev *dev;
414 	struct tty_struct *tty;
415 
416 	if (copy_from_user(&req, arg, sizeof(req)))
417 		return -EFAULT;
418 
419 	BT_DBG("dev_id %d flags 0x%x", req.dev_id, req.flags);
420 
421 	dev = rfcomm_dev_get(req.dev_id);
422 	if (!dev)
423 		return -ENODEV;
424 
425 	if (dev->flags != NOCAP_FLAGS && !capable(CAP_NET_ADMIN)) {
426 		tty_port_put(&dev->port);
427 		return -EPERM;
428 	}
429 
430 	if (req.flags & (1 << RFCOMM_HANGUP_NOW))
431 		rfcomm_dlc_close(dev->dlc, 0);
432 
433 	/* Shut down TTY synchronously before freeing rfcomm_dev */
434 	tty = tty_port_tty_get(&dev->port);
435 	if (tty) {
436 		tty_vhangup(tty);
437 		tty_kref_put(tty);
438 	}
439 
440 	if (!test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags))
441 		tty_port_put(&dev->port);
442 
443 	tty_port_put(&dev->port);
444 	return 0;
445 }
446 
447 static int rfcomm_get_dev_list(void __user *arg)
448 {
449 	struct rfcomm_dev *dev;
450 	struct rfcomm_dev_list_req *dl;
451 	struct rfcomm_dev_info *di;
452 	int n = 0, size, err;
453 	u16 dev_num;
454 
455 	BT_DBG("");
456 
457 	if (get_user(dev_num, (u16 __user *) arg))
458 		return -EFAULT;
459 
460 	if (!dev_num || dev_num > (PAGE_SIZE * 4) / sizeof(*di))
461 		return -EINVAL;
462 
463 	size = sizeof(*dl) + dev_num * sizeof(*di);
464 
465 	dl = kzalloc(size, GFP_KERNEL);
466 	if (!dl)
467 		return -ENOMEM;
468 
469 	di = dl->dev_info;
470 
471 	spin_lock(&rfcomm_dev_lock);
472 
473 	list_for_each_entry(dev, &rfcomm_dev_list, list) {
474 		if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
475 			continue;
476 		(di + n)->id      = dev->id;
477 		(di + n)->flags   = dev->flags;
478 		(di + n)->state   = dev->dlc->state;
479 		(di + n)->channel = dev->channel;
480 		bacpy(&(di + n)->src, &dev->src);
481 		bacpy(&(di + n)->dst, &dev->dst);
482 		if (++n >= dev_num)
483 			break;
484 	}
485 
486 	spin_unlock(&rfcomm_dev_lock);
487 
488 	dl->dev_num = n;
489 	size = sizeof(*dl) + n * sizeof(*di);
490 
491 	err = copy_to_user(arg, dl, size);
492 	kfree(dl);
493 
494 	return err ? -EFAULT : 0;
495 }
496 
497 static int rfcomm_get_dev_info(void __user *arg)
498 {
499 	struct rfcomm_dev *dev;
500 	struct rfcomm_dev_info di;
501 	int err = 0;
502 
503 	BT_DBG("");
504 
505 	if (copy_from_user(&di, arg, sizeof(di)))
506 		return -EFAULT;
507 
508 	dev = rfcomm_dev_get(di.id);
509 	if (!dev)
510 		return -ENODEV;
511 
512 	di.flags   = dev->flags;
513 	di.channel = dev->channel;
514 	di.state   = dev->dlc->state;
515 	bacpy(&di.src, &dev->src);
516 	bacpy(&di.dst, &dev->dst);
517 
518 	if (copy_to_user(arg, &di, sizeof(di)))
519 		err = -EFAULT;
520 
521 	tty_port_put(&dev->port);
522 	return err;
523 }
524 
525 int rfcomm_dev_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
526 {
527 	BT_DBG("cmd %d arg %p", cmd, arg);
528 
529 	switch (cmd) {
530 	case RFCOMMCREATEDEV:
531 		return rfcomm_create_dev(sk, arg);
532 
533 	case RFCOMMRELEASEDEV:
534 		return rfcomm_release_dev(arg);
535 
536 	case RFCOMMGETDEVLIST:
537 		return rfcomm_get_dev_list(arg);
538 
539 	case RFCOMMGETDEVINFO:
540 		return rfcomm_get_dev_info(arg);
541 	}
542 
543 	return -EINVAL;
544 }
545 
546 /* ---- DLC callbacks ---- */
547 static void rfcomm_dev_data_ready(struct rfcomm_dlc *dlc, struct sk_buff *skb)
548 {
549 	struct rfcomm_dev *dev = dlc->owner;
550 
551 	if (!dev) {
552 		kfree_skb(skb);
553 		return;
554 	}
555 
556 	if (!skb_queue_empty(&dev->pending)) {
557 		skb_queue_tail(&dev->pending, skb);
558 		return;
559 	}
560 
561 	BT_DBG("dlc %p len %d", dlc, skb->len);
562 
563 	tty_insert_flip_string(&dev->port, skb->data, skb->len);
564 	tty_flip_buffer_push(&dev->port);
565 
566 	kfree_skb(skb);
567 }
568 
569 static void rfcomm_dev_state_change(struct rfcomm_dlc *dlc, int err)
570 {
571 	struct rfcomm_dev *dev = dlc->owner;
572 	struct tty_struct *tty;
573 	if (!dev)
574 		return;
575 
576 	BT_DBG("dlc %p dev %p err %d", dlc, dev, err);
577 
578 	dev->err = err;
579 	if (dlc->state == BT_CONNECTED) {
580 		device_move(dev->tty_dev, rfcomm_get_device(dev),
581 			    DPM_ORDER_DEV_AFTER_PARENT);
582 
583 		wake_up_interruptible(&dev->port.open_wait);
584 	} else if (dlc->state == BT_CLOSED) {
585 		tty = tty_port_tty_get(&dev->port);
586 		if (!tty) {
587 			if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
588 				/* Drop DLC lock here to avoid deadlock
589 				 * 1. rfcomm_dev_get will take rfcomm_dev_lock
590 				 *    but in rfcomm_dev_add there's lock order:
591 				 *    rfcomm_dev_lock -> dlc lock
592 				 * 2. tty_port_put will deadlock if it's
593 				 *    the last reference
594 				 *
595 				 * FIXME: when we release the lock anything
596 				 * could happen to dev, even its destruction
597 				 */
598 				rfcomm_dlc_unlock(dlc);
599 				if (rfcomm_dev_get(dev->id) == NULL) {
600 					rfcomm_dlc_lock(dlc);
601 					return;
602 				}
603 
604 				if (!test_and_set_bit(RFCOMM_TTY_RELEASED,
605 						      &dev->flags))
606 					tty_port_put(&dev->port);
607 
608 				tty_port_put(&dev->port);
609 				rfcomm_dlc_lock(dlc);
610 			}
611 		} else {
612 			tty_hangup(tty);
613 			tty_kref_put(tty);
614 		}
615 	}
616 }
617 
618 static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)
619 {
620 	struct rfcomm_dev *dev = dlc->owner;
621 	if (!dev)
622 		return;
623 
624 	BT_DBG("dlc %p dev %p v24_sig 0x%02x", dlc, dev, v24_sig);
625 
626 	if ((dev->modem_status & TIOCM_CD) && !(v24_sig & RFCOMM_V24_DV))
627 		tty_port_tty_hangup(&dev->port, true);
628 
629 	dev->modem_status =
630 		((v24_sig & RFCOMM_V24_RTC) ? (TIOCM_DSR | TIOCM_DTR) : 0) |
631 		((v24_sig & RFCOMM_V24_RTR) ? (TIOCM_RTS | TIOCM_CTS) : 0) |
632 		((v24_sig & RFCOMM_V24_IC)  ? TIOCM_RI : 0) |
633 		((v24_sig & RFCOMM_V24_DV)  ? TIOCM_CD : 0);
634 }
635 
636 /* ---- TTY functions ---- */
637 static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
638 {
639 	struct sk_buff *skb;
640 	int inserted = 0;
641 
642 	BT_DBG("dev %p", dev);
643 
644 	rfcomm_dlc_lock(dev->dlc);
645 
646 	while ((skb = skb_dequeue(&dev->pending))) {
647 		inserted += tty_insert_flip_string(&dev->port, skb->data,
648 				skb->len);
649 		kfree_skb(skb);
650 	}
651 
652 	rfcomm_dlc_unlock(dev->dlc);
653 
654 	if (inserted > 0)
655 		tty_flip_buffer_push(&dev->port);
656 }
657 
658 /* do the reverse of install, clearing the tty fields and releasing the
659  * reference to tty_port
660  */
661 static void rfcomm_tty_cleanup(struct tty_struct *tty)
662 {
663 	struct rfcomm_dev *dev = tty->driver_data;
664 
665 	clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
666 
667 	rfcomm_dlc_lock(dev->dlc);
668 	tty->driver_data = NULL;
669 	rfcomm_dlc_unlock(dev->dlc);
670 
671 	/*
672 	 * purge the dlc->tx_queue to avoid circular dependencies
673 	 * between dev and dlc
674 	 */
675 	skb_queue_purge(&dev->dlc->tx_queue);
676 
677 	tty_port_put(&dev->port);
678 }
679 
680 /* we acquire the tty_port reference since it's here the tty is first used
681  * by setting the termios. We also populate the driver_data field and install
682  * the tty port
683  */
684 static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
685 {
686 	struct rfcomm_dev *dev;
687 	struct rfcomm_dlc *dlc;
688 	int err;
689 
690 	dev = rfcomm_dev_get(tty->index);
691 	if (!dev)
692 		return -ENODEV;
693 
694 	dlc = dev->dlc;
695 
696 	/* Attach TTY and open DLC */
697 	rfcomm_dlc_lock(dlc);
698 	tty->driver_data = dev;
699 	rfcomm_dlc_unlock(dlc);
700 	set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
701 
702 	/* install the tty_port */
703 	err = tty_port_install(&dev->port, driver, tty);
704 	if (err)
705 		rfcomm_tty_cleanup(tty);
706 
707 	return err;
708 }
709 
710 static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
711 {
712 	struct rfcomm_dev *dev = tty->driver_data;
713 	int err;
714 
715 	BT_DBG("tty %p id %d", tty, tty->index);
716 
717 	BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
718 	       dev->channel, dev->port.count);
719 
720 	err = tty_port_open(&dev->port, tty, filp);
721 	if (err)
722 		return err;
723 
724 	/*
725 	 * FIXME: rfcomm should use proper flow control for
726 	 * received data. This hack will be unnecessary and can
727 	 * be removed when that's implemented
728 	 */
729 	rfcomm_tty_copy_pending(dev);
730 
731 	rfcomm_dlc_unthrottle(dev->dlc);
732 
733 	return 0;
734 }
735 
736 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
737 {
738 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
739 
740 	BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
741 						dev->port.count);
742 
743 	tty_port_close(&dev->port, tty, filp);
744 }
745 
746 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
747 {
748 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
749 	struct rfcomm_dlc *dlc = dev->dlc;
750 	struct sk_buff *skb;
751 	int err = 0, sent = 0, size;
752 
753 	BT_DBG("tty %p count %d", tty, count);
754 
755 	while (count) {
756 		size = min_t(uint, count, dlc->mtu);
757 
758 		skb = rfcomm_wmalloc(dev, size + RFCOMM_SKB_RESERVE, GFP_ATOMIC);
759 
760 		if (!skb)
761 			break;
762 
763 		skb_reserve(skb, RFCOMM_SKB_HEAD_RESERVE);
764 
765 		memcpy(skb_put(skb, size), buf + sent, size);
766 
767 		err = rfcomm_dlc_send(dlc, skb);
768 		if (err < 0) {
769 			kfree_skb(skb);
770 			break;
771 		}
772 
773 		sent  += size;
774 		count -= size;
775 	}
776 
777 	return sent ? sent : err;
778 }
779 
780 static int rfcomm_tty_write_room(struct tty_struct *tty)
781 {
782 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
783 	int room;
784 
785 	BT_DBG("tty %p", tty);
786 
787 	if (!dev || !dev->dlc)
788 		return 0;
789 
790 	room = rfcomm_room(dev->dlc) - atomic_read(&dev->wmem_alloc);
791 	if (room < 0)
792 		room = 0;
793 
794 	return room;
795 }
796 
797 static int rfcomm_tty_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
798 {
799 	BT_DBG("tty %p cmd 0x%02x", tty, cmd);
800 
801 	switch (cmd) {
802 	case TCGETS:
803 		BT_DBG("TCGETS is not supported");
804 		return -ENOIOCTLCMD;
805 
806 	case TCSETS:
807 		BT_DBG("TCSETS is not supported");
808 		return -ENOIOCTLCMD;
809 
810 	case TIOCMIWAIT:
811 		BT_DBG("TIOCMIWAIT");
812 		break;
813 
814 	case TIOCGSERIAL:
815 		BT_ERR("TIOCGSERIAL is not supported");
816 		return -ENOIOCTLCMD;
817 
818 	case TIOCSSERIAL:
819 		BT_ERR("TIOCSSERIAL is not supported");
820 		return -ENOIOCTLCMD;
821 
822 	case TIOCSERGSTRUCT:
823 		BT_ERR("TIOCSERGSTRUCT is not supported");
824 		return -ENOIOCTLCMD;
825 
826 	case TIOCSERGETLSR:
827 		BT_ERR("TIOCSERGETLSR is not supported");
828 		return -ENOIOCTLCMD;
829 
830 	case TIOCSERCONFIG:
831 		BT_ERR("TIOCSERCONFIG is not supported");
832 		return -ENOIOCTLCMD;
833 
834 	default:
835 		return -ENOIOCTLCMD;	/* ioctls which we must ignore */
836 
837 	}
838 
839 	return -ENOIOCTLCMD;
840 }
841 
842 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
843 {
844 	struct ktermios *new = &tty->termios;
845 	int old_baud_rate = tty_termios_baud_rate(old);
846 	int new_baud_rate = tty_termios_baud_rate(new);
847 
848 	u8 baud, data_bits, stop_bits, parity, x_on, x_off;
849 	u16 changes = 0;
850 
851 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
852 
853 	BT_DBG("tty %p termios %p", tty, old);
854 
855 	if (!dev || !dev->dlc || !dev->dlc->session)
856 		return;
857 
858 	/* Handle turning off CRTSCTS */
859 	if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS))
860 		BT_DBG("Turning off CRTSCTS unsupported");
861 
862 	/* Parity on/off and when on, odd/even */
863 	if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
864 			((old->c_cflag & PARODD) != (new->c_cflag & PARODD))) {
865 		changes |= RFCOMM_RPN_PM_PARITY;
866 		BT_DBG("Parity change detected.");
867 	}
868 
869 	/* Mark and space parity are not supported! */
870 	if (new->c_cflag & PARENB) {
871 		if (new->c_cflag & PARODD) {
872 			BT_DBG("Parity is ODD");
873 			parity = RFCOMM_RPN_PARITY_ODD;
874 		} else {
875 			BT_DBG("Parity is EVEN");
876 			parity = RFCOMM_RPN_PARITY_EVEN;
877 		}
878 	} else {
879 		BT_DBG("Parity is OFF");
880 		parity = RFCOMM_RPN_PARITY_NONE;
881 	}
882 
883 	/* Setting the x_on / x_off characters */
884 	if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
885 		BT_DBG("XOFF custom");
886 		x_on = new->c_cc[VSTOP];
887 		changes |= RFCOMM_RPN_PM_XON;
888 	} else {
889 		BT_DBG("XOFF default");
890 		x_on = RFCOMM_RPN_XON_CHAR;
891 	}
892 
893 	if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
894 		BT_DBG("XON custom");
895 		x_off = new->c_cc[VSTART];
896 		changes |= RFCOMM_RPN_PM_XOFF;
897 	} else {
898 		BT_DBG("XON default");
899 		x_off = RFCOMM_RPN_XOFF_CHAR;
900 	}
901 
902 	/* Handle setting of stop bits */
903 	if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
904 		changes |= RFCOMM_RPN_PM_STOP;
905 
906 	/* POSIX does not support 1.5 stop bits and RFCOMM does not
907 	 * support 2 stop bits. So a request for 2 stop bits gets
908 	 * translated to 1.5 stop bits */
909 	if (new->c_cflag & CSTOPB)
910 		stop_bits = RFCOMM_RPN_STOP_15;
911 	else
912 		stop_bits = RFCOMM_RPN_STOP_1;
913 
914 	/* Handle number of data bits [5-8] */
915 	if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE))
916 		changes |= RFCOMM_RPN_PM_DATA;
917 
918 	switch (new->c_cflag & CSIZE) {
919 	case CS5:
920 		data_bits = RFCOMM_RPN_DATA_5;
921 		break;
922 	case CS6:
923 		data_bits = RFCOMM_RPN_DATA_6;
924 		break;
925 	case CS7:
926 		data_bits = RFCOMM_RPN_DATA_7;
927 		break;
928 	case CS8:
929 		data_bits = RFCOMM_RPN_DATA_8;
930 		break;
931 	default:
932 		data_bits = RFCOMM_RPN_DATA_8;
933 		break;
934 	}
935 
936 	/* Handle baudrate settings */
937 	if (old_baud_rate != new_baud_rate)
938 		changes |= RFCOMM_RPN_PM_BITRATE;
939 
940 	switch (new_baud_rate) {
941 	case 2400:
942 		baud = RFCOMM_RPN_BR_2400;
943 		break;
944 	case 4800:
945 		baud = RFCOMM_RPN_BR_4800;
946 		break;
947 	case 7200:
948 		baud = RFCOMM_RPN_BR_7200;
949 		break;
950 	case 9600:
951 		baud = RFCOMM_RPN_BR_9600;
952 		break;
953 	case 19200:
954 		baud = RFCOMM_RPN_BR_19200;
955 		break;
956 	case 38400:
957 		baud = RFCOMM_RPN_BR_38400;
958 		break;
959 	case 57600:
960 		baud = RFCOMM_RPN_BR_57600;
961 		break;
962 	case 115200:
963 		baud = RFCOMM_RPN_BR_115200;
964 		break;
965 	case 230400:
966 		baud = RFCOMM_RPN_BR_230400;
967 		break;
968 	default:
969 		/* 9600 is standard accordinag to the RFCOMM specification */
970 		baud = RFCOMM_RPN_BR_9600;
971 		break;
972 
973 	}
974 
975 	if (changes)
976 		rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
977 				data_bits, stop_bits, parity,
978 				RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
979 }
980 
981 static void rfcomm_tty_throttle(struct tty_struct *tty)
982 {
983 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
984 
985 	BT_DBG("tty %p dev %p", tty, dev);
986 
987 	rfcomm_dlc_throttle(dev->dlc);
988 }
989 
990 static void rfcomm_tty_unthrottle(struct tty_struct *tty)
991 {
992 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
993 
994 	BT_DBG("tty %p dev %p", tty, dev);
995 
996 	rfcomm_dlc_unthrottle(dev->dlc);
997 }
998 
999 static int rfcomm_tty_chars_in_buffer(struct tty_struct *tty)
1000 {
1001 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1002 
1003 	BT_DBG("tty %p dev %p", tty, dev);
1004 
1005 	if (!dev || !dev->dlc)
1006 		return 0;
1007 
1008 	if (!skb_queue_empty(&dev->dlc->tx_queue))
1009 		return dev->dlc->mtu;
1010 
1011 	return 0;
1012 }
1013 
1014 static void rfcomm_tty_flush_buffer(struct tty_struct *tty)
1015 {
1016 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1017 
1018 	BT_DBG("tty %p dev %p", tty, dev);
1019 
1020 	if (!dev || !dev->dlc)
1021 		return;
1022 
1023 	skb_queue_purge(&dev->dlc->tx_queue);
1024 	tty_wakeup(tty);
1025 }
1026 
1027 static void rfcomm_tty_send_xchar(struct tty_struct *tty, char ch)
1028 {
1029 	BT_DBG("tty %p ch %c", tty, ch);
1030 }
1031 
1032 static void rfcomm_tty_wait_until_sent(struct tty_struct *tty, int timeout)
1033 {
1034 	BT_DBG("tty %p timeout %d", tty, timeout);
1035 }
1036 
1037 static void rfcomm_tty_hangup(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 	tty_port_hangup(&dev->port);
1044 
1045 	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags) &&
1046 	    !test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags))
1047 		tty_port_put(&dev->port);
1048 }
1049 
1050 static int rfcomm_tty_tiocmget(struct tty_struct *tty)
1051 {
1052 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1053 
1054 	BT_DBG("tty %p dev %p", tty, dev);
1055 
1056 	return dev->modem_status;
1057 }
1058 
1059 static int rfcomm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
1060 {
1061 	struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
1062 	struct rfcomm_dlc *dlc = dev->dlc;
1063 	u8 v24_sig;
1064 
1065 	BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
1066 
1067 	rfcomm_dlc_get_modem_status(dlc, &v24_sig);
1068 
1069 	if (set & TIOCM_DSR || set & TIOCM_DTR)
1070 		v24_sig |= RFCOMM_V24_RTC;
1071 	if (set & TIOCM_RTS || set & TIOCM_CTS)
1072 		v24_sig |= RFCOMM_V24_RTR;
1073 	if (set & TIOCM_RI)
1074 		v24_sig |= RFCOMM_V24_IC;
1075 	if (set & TIOCM_CD)
1076 		v24_sig |= RFCOMM_V24_DV;
1077 
1078 	if (clear & TIOCM_DSR || clear & TIOCM_DTR)
1079 		v24_sig &= ~RFCOMM_V24_RTC;
1080 	if (clear & TIOCM_RTS || clear & TIOCM_CTS)
1081 		v24_sig &= ~RFCOMM_V24_RTR;
1082 	if (clear & TIOCM_RI)
1083 		v24_sig &= ~RFCOMM_V24_IC;
1084 	if (clear & TIOCM_CD)
1085 		v24_sig &= ~RFCOMM_V24_DV;
1086 
1087 	rfcomm_dlc_set_modem_status(dlc, v24_sig);
1088 
1089 	return 0;
1090 }
1091 
1092 /* ---- TTY structure ---- */
1093 
1094 static const struct tty_operations rfcomm_ops = {
1095 	.open			= rfcomm_tty_open,
1096 	.close			= rfcomm_tty_close,
1097 	.write			= rfcomm_tty_write,
1098 	.write_room		= rfcomm_tty_write_room,
1099 	.chars_in_buffer	= rfcomm_tty_chars_in_buffer,
1100 	.flush_buffer		= rfcomm_tty_flush_buffer,
1101 	.ioctl			= rfcomm_tty_ioctl,
1102 	.throttle		= rfcomm_tty_throttle,
1103 	.unthrottle		= rfcomm_tty_unthrottle,
1104 	.set_termios		= rfcomm_tty_set_termios,
1105 	.send_xchar		= rfcomm_tty_send_xchar,
1106 	.hangup			= rfcomm_tty_hangup,
1107 	.wait_until_sent	= rfcomm_tty_wait_until_sent,
1108 	.tiocmget		= rfcomm_tty_tiocmget,
1109 	.tiocmset		= rfcomm_tty_tiocmset,
1110 	.install                = rfcomm_tty_install,
1111 	.cleanup                = rfcomm_tty_cleanup,
1112 };
1113 
1114 int __init rfcomm_init_ttys(void)
1115 {
1116 	int error;
1117 
1118 	rfcomm_tty_driver = alloc_tty_driver(RFCOMM_TTY_PORTS);
1119 	if (!rfcomm_tty_driver)
1120 		return -ENOMEM;
1121 
1122 	rfcomm_tty_driver->driver_name	= "rfcomm";
1123 	rfcomm_tty_driver->name		= "rfcomm";
1124 	rfcomm_tty_driver->major	= RFCOMM_TTY_MAJOR;
1125 	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
1126 	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
1127 	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
1128 	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1129 	rfcomm_tty_driver->init_termios	= tty_std_termios;
1130 	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL;
1131 	rfcomm_tty_driver->init_termios.c_lflag &= ~ICANON;
1132 	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);
1133 
1134 	error = tty_register_driver(rfcomm_tty_driver);
1135 	if (error) {
1136 		BT_ERR("Can't register RFCOMM TTY driver");
1137 		put_tty_driver(rfcomm_tty_driver);
1138 		return error;
1139 	}
1140 
1141 	BT_INFO("RFCOMM TTY layer initialized");
1142 
1143 	return 0;
1144 }
1145 
1146 void rfcomm_cleanup_ttys(void)
1147 {
1148 	tty_unregister_driver(rfcomm_tty_driver);
1149 	put_tty_driver(rfcomm_tty_driver);
1150 }
1151