summaryrefslogtreecommitdiff
path: root/drivers/bluetooth/hci_vhci.c
blob: 572d68d52965f640aef81e18962d59f0e6232e40 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 *  Bluetooth virtual HCI driver
 *
 *  Copyright (C) 2000-2001  Qualcomm Incorporated
 *  Copyright (C) 2002-2003  Maxim Krasnyansky <maxk@qualcomm.com>
 *  Copyright (C) 2004-2006  Marcel Holtmann <marcel@holtmann.org>
 */

#include <linux/module.h>
#include <asm/unaligned.h>

#include <linux/atomic.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/poll.h>

#include <linux/skbuff.h>
#include <linux/miscdevice.h>
#include <linux/debugfs.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>

#define VERSION "1.5"

static bool amp;

struct vhci_data {
	struct hci_dev *hdev;

	wait_queue_head_t read_wait;
	struct sk_buff_head readq;

	struct mutex open_mutex;
	struct delayed_work open_timeout;
	struct work_struct suspend_work;

	bool suspended;
	bool wakeup;
	__u16 msft_opcode;
	bool aosp_capable;
	atomic_t initialized;
};

static int vhci_open_dev(struct hci_dev *hdev)
{
	return 0;
}

static int vhci_close_dev(struct hci_dev *hdev)
{
	struct vhci_data *data = hci_get_drvdata(hdev);

	skb_queue_purge(&data->readq);

	return 0;
}

static int vhci_flush(struct hci_dev *hdev)
{
	struct vhci_data *data = hci_get_drvdata(hdev);

	skb_queue_purge(&data->readq);

	return 0;
}

static int vhci_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct vhci_data *data = hci_get_drvdata(hdev);

	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);

	skb_queue_tail(&data->readq, skb);

	if (atomic_read(&data->initialized))
		wake_up_interruptible(&data->read_wait);
	return 0;
}

static int vhci_get_data_path_id(struct hci_dev *hdev, u8 *data_path_id)
{
	*data_path_id = 0;
	return 0;
}

static int vhci_get_codec_config_data(struct hci_dev *hdev, __u8 type,
				      struct bt_codec *codec, __u8 *vnd_len,
				      __u8 **vnd_data)
{
	if (type != ESCO_LINK)
		return -EINVAL;

	*vnd_len = 0;
	*vnd_data = NULL;
	return 0;
}

static bool vhci_wakeup(struct hci_dev *hdev)
{
	struct vhci_data *data = hci_get_drvdata(hdev);

	return data->wakeup;
}

static ssize_t force_suspend_read(struct file *file, char __user *user_buf,
				  size_t count, loff_t *ppos)
{
	struct vhci_data *data = file->private_data;
	char buf[3];

	buf[0] = data->suspended ? 'Y' : 'N';
	buf[1] = '\n';
	buf[2] = '\0';
	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static void vhci_suspend_work(struct work_struct *work)
{
	struct vhci_data *data = container_of(work, struct vhci_data,
					      suspend_work);

	if (data->suspended)
		hci_suspend_dev(data->hdev);
	else
		hci_resume_dev(data->hdev);
}

static ssize_t force_suspend_write(struct file *file,
				   const char __user *user_buf,
				   size_t count, loff_t *ppos)
{
	struct vhci_data *data = file->private_data;
	bool enable;
	int err;

	err = kstrtobool_from_user(user_buf, count, &enable);
	if (err)
		return err;

	if (data->suspended == enable)
		return -EALREADY;

	data->suspended = enable;

	schedule_work(&data->suspend_work);

	return count;
}

static const struct file_operations force_suspend_fops = {
	.open		= simple_open,
	.read		= force_suspend_read,
	.write		= force_suspend_write,
	.llseek		= default_llseek,
};

static ssize_t force_wakeup_read(struct file *file, char __user *user_buf,
				 size_t count, loff_t *ppos)
{
	struct vhci_data *data = file->private_data;
	char buf[3];

	buf[0] = data->wakeup ? 'Y' : 'N';
	buf[1] = '\n';
	buf[2] = '\0';
	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static ssize_t force_wakeup_write(struct file *file,
				  const char __user *user_buf, size_t count,
				  loff_t *ppos)
{
	struct vhci_data *data = file->private_data;
	bool enable;
	int err;

	err = kstrtobool_from_user(user_buf, count, &enable);
	if (err)
		return err;

	if (data->wakeup == enable)
		return -EALREADY;

	data->wakeup = enable;

	return count;
}

static const struct file_operations force_wakeup_fops = {
	.open		= simple_open,
	.read		= force_wakeup_read,
	.write		= force_wakeup_write,
	.llseek		= default_llseek,
};

static int msft_opcode_set(void *data, u64 val)
{
	struct vhci_data *vhci = data;

	if (val > 0xffff || hci_opcode_ogf(val) != 0x3f)
		return -EINVAL;

	if (vhci->msft_opcode)
		return -EALREADY;

	vhci->msft_opcode = val;

	return 0;
}

static int msft_opcode_get(void *data, u64 *val)
{
	struct vhci_data *vhci = data;

	*val = vhci->msft_opcode;

	return 0;
}

DEFINE_DEBUGFS_ATTRIBUTE(msft_opcode_fops, msft_opcode_get, msft_opcode_set,
			 "%llu\n");

static ssize_t aosp_capable_read(struct file *file, char __user *user_buf,
				 size_t count, loff_t *ppos)
{
	struct vhci_data *vhci = file->private_data;
	char buf[3];

	buf[0] = vhci->aosp_capable ? 'Y' : 'N';
	buf[1] = '\n';
	buf[2] = '\0';
	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
}

static ssize_t aosp_capable_write(struct file *file,
				  const char __user *user_buf, size_t count,
				  loff_t *ppos)
{
	struct vhci_data *vhci = file->private_data;
	bool enable;
	int err;

	err = kstrtobool_from_user(user_buf, count, &enable);
	if (err)
		return err;

	if (!enable)
		return -EINVAL;

	if (vhci->aosp_capable)
		return -EALREADY;

	vhci->aosp_capable = enable;

	return count;
}

static const struct file_operations aosp_capable_fops = {
	.open		= simple_open,
	.read		= aosp_capable_read,
	.write		= aosp_capable_write,
	.llseek		= default_llseek,
};

static int vhci_setup(struct hci_dev *hdev)
{
	struct vhci_data *vhci = hci_get_drvdata(hdev);

	if (vhci->msft_opcode)
		hci_set_msft_opcode(hdev, vhci->msft_opcode);

	if (vhci->aosp_capable)
		hci_set_aosp_capable(hdev);

	return 0;
}

static void vhci_coredump(struct hci_dev *hdev)
{
	/* No need to do anything */
}

static void vhci_coredump_hdr(struct hci_dev *hdev, struct sk_buff *skb)
{
	char buf[80];

	snprintf(buf, sizeof(buf), "Controller Name: vhci_ctrl\n");
	skb_put_data(skb, buf, strlen(buf));

	snprintf(buf, sizeof(buf), "Firmware Version: vhci_fw\n");
	skb_put_data(skb, buf, strlen(buf));

	snprintf(buf, sizeof(buf), "Driver: vhci_drv\n");
	skb_put_data(skb, buf, strlen(buf));

	snprintf(buf, sizeof(buf), "Vendor: vhci\n");
	skb_put_data(skb, buf, strlen(buf));
}

#define MAX_COREDUMP_LINE_LEN	40

struct devcoredump_test_data {
	enum devcoredump_state state;
	unsigned int timeout;
	char data[MAX_COREDUMP_LINE_LEN];
};

static inline void force_devcd_timeout(struct hci_dev *hdev,
				       unsigned int timeout)
{
#ifdef CONFIG_DEV_COREDUMP
	hdev->dump.timeout = msecs_to_jiffies(timeout * 1000);
#endif
}

static ssize_t force_devcd_write(struct file *file, const char __user *user_buf,
				 size_t count, loff_t *ppos)
{
	struct vhci_data *data = file->private_data;
	struct hci_dev *hdev = data->hdev;
	struct sk_buff *skb = NULL;
	struct devcoredump_test_data dump_data;
	size_t data_size;
	int ret;

	if (count < offsetof(struct devcoredump_test_data, data) ||
	    count > sizeof(dump_data))
		return -EINVAL;

	if (copy_from_user(&dump_data, user_buf, count))
		return -EFAULT;

	data_size = count - offsetof(struct devcoredump_test_data, data);
	skb = alloc_skb(data_size, GFP_ATOMIC);
	if (!skb)
		return -ENOMEM;
	skb_put_data(skb, &dump_data.data, data_size);

	hci_devcd_register(hdev, vhci_coredump, vhci_coredump_hdr, NULL);

	/* Force the devcoredump timeout */
	if (dump_data.timeout)
		force_devcd_timeout(hdev, dump_data.timeout);

	ret = hci_devcd_init(hdev, skb->len);
	if (ret) {
		BT_ERR("Failed to generate devcoredump");
		kfree_skb(skb);
		return ret;
	}

	hci_devcd_append(hdev, skb);

	switch (dump_data.state) {
	case HCI_DEVCOREDUMP_DONE:
		hci_devcd_complete(hdev);
		break;
	case HCI_DEVCOREDUMP_ABORT:
		hci_devcd_abort(hdev);
		break;
	case HCI_DEVCOREDUMP_TIMEOUT:
		/* Do nothing */
		break;
	default:
		return -EINVAL;
	}

	return count;
}

static const struct file_operations force_devcoredump_fops = {
	.open		= simple_open,
	.write		= force_devcd_write,
};

static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
{
	struct hci_dev *hdev;
	struct sk_buff *skb;
	__u8 dev_type;

	if (data->hdev)
		return -EBADFD;

	/* bits 0-1 are dev_type (Primary or AMP) */
	dev_type = opcode & 0x03;

	if (dev_type != HCI_PRIMARY && dev_type != HCI_AMP)
		return -EINVAL;

	/* bits 2-5 are reserved (must be zero) */
	if (opcode & 0x3c)
		return -EINVAL;

	skb = bt_skb_alloc(4, GFP_KERNEL);
	if (!skb)
		return -ENOMEM;

	hdev = hci_alloc_dev();
	if (!hdev) {
		kfree_skb(skb);
		return -ENOMEM;
	}

	data->hdev = hdev;

	hdev->bus = HCI_VIRTUAL;
	hdev->dev_type = dev_type;
	hci_set_drvdata(hdev, data);

	hdev->open  = vhci_open_dev;
	hdev->close = vhci_close_dev;
	hdev->flush = vhci_flush;
	hdev->send  = vhci_send_frame;
	hdev->get_data_path_id = vhci_get_data_path_id;
	hdev->get_codec_config_data = vhci_get_codec_config_data;
	hdev->wakeup = vhci_wakeup;
	hdev->setup = vhci_setup;
	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);

	/* bit 6 is for external configuration */
	if (opcode & 0x40)
		set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);

	/* bit 7 is for raw device */
	if (opcode & 0x80)
		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);

	set_bit(HCI_QUIRK_VALID_LE_STATES, &hdev->quirks);

	if (hci_register_dev(hdev) < 0) {
		BT_ERR("Can't register HCI device");
		hci_free_dev(hdev);
		data->hdev = NULL;
		kfree_skb(skb);
		return -EBUSY;
	}

	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
			    &force_suspend_fops);

	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
			    &force_wakeup_fops);

	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
				    &msft_opcode_fops);

	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
				    &aosp_capable_fops);

	debugfs_create_file("force_devcoredump", 0644, hdev->debugfs, data,
			    &force_devcoredump_fops);

	hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;

	skb_put_u8(skb, 0xff);
	skb_put_u8(skb, opcode);
	put_unaligned_le16(hdev->id, skb_put(skb, 2));
	skb_queue_head(&data->readq, skb);
	atomic_inc(&data->initialized);

	wake_up_interruptible(&data->read_wait);
	return 0;
}

static int vhci_create_device(struct vhci_data *data, __u8 opcode)
{
	int err;

	mutex_lock(&data->open_mutex);
	err = __vhci_create_device(data, opcode);
	mutex_unlock(&data->open_mutex);

	return err;
}

static inline ssize_t vhci_get_user(struct vhci_data *data,
				    struct iov_iter *from)
{
	size_t len = iov_iter_count(from);
	struct sk_buff *skb;
	__u8 pkt_type, opcode;
	int ret;

	if (len < 2 || len > HCI_MAX_FRAME_SIZE)
		return -EINVAL;

	skb = bt_skb_alloc(len, GFP_KERNEL);
	if (!skb)
		return -ENOMEM;

	if (!copy_from_iter_full(skb_put(skb, len), len, from)) {
		kfree_skb(skb);
		return -EFAULT;
	}

	pkt_type = *((__u8 *) skb->data);
	skb_pull(skb, 1);

	switch (pkt_type) {
	case HCI_EVENT_PKT:
	case HCI_ACLDATA_PKT:
	case HCI_SCODATA_PKT:
	case HCI_ISODATA_PKT:
		if (!data->hdev) {
			kfree_skb(skb);
			return -ENODEV;
		}

		hci_skb_pkt_type(skb) = pkt_type;

		ret = hci_recv_frame(data->hdev, skb);
		break;

	case HCI_VENDOR_PKT:
		cancel_delayed_work_sync(&data->open_timeout);

		opcode = *((__u8 *) skb->data);
		skb_pull(skb, 1);

		if (skb->len > 0) {
			kfree_skb(skb);
			return -EINVAL;
		}

		kfree_skb(skb);

		ret = vhci_create_device(data, opcode);
		break;

	default:
		kfree_skb(skb);
		return -EINVAL;
	}

	return (ret < 0) ? ret : len;
}

static inline ssize_t vhci_put_user(struct vhci_data *data,
				    struct sk_buff *skb,
				    char __user *buf, int count)
{
	char __user *ptr = buf;
	int len;

	len = min_t(unsigned int, skb->len, count);

	if (copy_to_user(ptr, skb->data, len))
		return -EFAULT;

	if (!data->hdev)
		return len;

	data->hdev->stat.byte_tx += len;

	switch (hci_skb_pkt_type(skb)) {
	case HCI_COMMAND_PKT:
		data->hdev->stat.cmd_tx++;
		break;
	case HCI_ACLDATA_PKT:
		data->hdev->stat.acl_tx++;
		break;
	case HCI_SCODATA_PKT:
		data->hdev->stat.sco_tx++;
		break;
	}

	return len;
}

static ssize_t vhci_read(struct file *file,
			 char __user *buf, size_t count, loff_t *pos)
{
	struct vhci_data *data = file->private_data;
	struct sk_buff *skb;
	ssize_t ret = 0;

	while (count) {
		skb = skb_dequeue(&data->readq);
		if (skb) {
			ret = vhci_put_user(data, skb, buf, count);
			if (ret < 0)
				skb_queue_head(&data->readq, skb);
			else
				kfree_skb(skb);
			break;
		}

		if (file->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			break;
		}

		ret = wait_event_interruptible(data->read_wait,
					       !skb_queue_empty(&data->readq));
		if (ret < 0)
			break;
	}

	return ret;
}

static ssize_t vhci_write(struct kiocb *iocb, struct iov_iter *from)
{
	struct file *file = iocb->ki_filp;
	struct vhci_data *data = file->private_data;

	return vhci_get_user(data, from);
}

static __poll_t vhci_poll(struct file *file, poll_table *wait)
{
	struct vhci_data *data = file->private_data;

	poll_wait(file, &data->read_wait, wait);

	if (!skb_queue_empty(&data->readq))
		return EPOLLIN | EPOLLRDNORM;

	return EPOLLOUT | EPOLLWRNORM;
}

static void vhci_open_timeout(struct work_struct *work)
{
	struct vhci_data *data = container_of(work, struct vhci_data,
					      open_timeout.work);

	vhci_create_device(data, amp ? HCI_AMP : HCI_PRIMARY);
}

static int vhci_open(struct inode *inode, struct file *file)
{
	struct vhci_data *data;

	data = kzalloc(sizeof(struct vhci_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	skb_queue_head_init(&data->readq);
	init_waitqueue_head(&data->read_wait);

	mutex_init(&data->open_mutex);
	INIT_DELAYED_WORK(&data->open_timeout, vhci_open_timeout);
	INIT_WORK(&data->suspend_work, vhci_suspend_work);

	file->private_data = data;
	nonseekable_open(inode, file);

	schedule_delayed_work(&data->open_timeout, msecs_to_jiffies(1000));

	return 0;
}

static int vhci_release(struct inode *inode, struct file *file)
{
	struct vhci_data *data = file->private_data;
	struct hci_dev *hdev;

	cancel_delayed_work_sync(&data->open_timeout);
	flush_work(&data->suspend_work);

	hdev = data->hdev;

	if (hdev) {
		hci_unregister_dev(hdev);
		hci_free_dev(hdev);
	}

	skb_queue_purge(&data->readq);
	file->private_data = NULL;
	kfree(data);

	return 0;
}

static const struct file_operations vhci_fops = {
	.owner		= THIS_MODULE,
	.read		= vhci_read,
	.write_iter	= vhci_write,
	.poll		= vhci_poll,
	.open		= vhci_open,
	.release	= vhci_release,
	.llseek		= no_llseek,
};

static struct miscdevice vhci_miscdev = {
	.name	= "vhci",
	.fops	= &vhci_fops,
	.minor	= VHCI_MINOR,
};
module_misc_device(vhci_miscdev);

module_param(amp, bool, 0644);
MODULE_PARM_DESC(amp, "Create AMP controller device");

MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
MODULE_DESCRIPTION("Bluetooth virtual HCI driver ver " VERSION);
MODULE_VERSION(VERSION);
MODULE_LICENSE("GPL");
MODULE_ALIAS("devname:vhci");
MODULE_ALIAS_MISCDEV(VHCI_MINOR);