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