summaryrefslogtreecommitdiffstats
path: root/net/bluetooth/msft.c
blob: 47b104f318e934904545ab74f3608a8353890d66 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020 Google Corporation
 */

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

#include "hci_request.h"
#include "mgmt_util.h"
#include "msft.h"

#define MSFT_RSSI_THRESHOLD_VALUE_MIN		-127
#define MSFT_RSSI_THRESHOLD_VALUE_MAX		20
#define MSFT_RSSI_LOW_TIMEOUT_MAX		0x3C

#define MSFT_OP_READ_SUPPORTED_FEATURES		0x00
struct msft_cp_read_supported_features {
	__u8   sub_opcode;
} __packed;

struct msft_rp_read_supported_features {
	__u8   status;
	__u8   sub_opcode;
	__le64 features;
	__u8   evt_prefix_len;
	__u8   evt_prefix[];
} __packed;

#define MSFT_OP_LE_MONITOR_ADVERTISEMENT	0x03
#define MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN	0x01
struct msft_le_monitor_advertisement_pattern {
	__u8 length;
	__u8 data_type;
	__u8 start_byte;
	__u8 pattern[0];
};

struct msft_le_monitor_advertisement_pattern_data {
	__u8 count;
	__u8 data[0];
};

struct msft_cp_le_monitor_advertisement {
	__u8 sub_opcode;
	__s8 rssi_high;
	__s8 rssi_low;
	__u8 rssi_low_interval;
	__u8 rssi_sampling_period;
	__u8 cond_type;
	__u8 data[0];
} __packed;

struct msft_rp_le_monitor_advertisement {
	__u8 status;
	__u8 sub_opcode;
	__u8 handle;
} __packed;

#define MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT	0x04
struct msft_cp_le_cancel_monitor_advertisement {
	__u8 sub_opcode;
	__u8 handle;
} __packed;

struct msft_rp_le_cancel_monitor_advertisement {
	__u8 status;
	__u8 sub_opcode;
} __packed;

#define MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE	0x05
struct msft_cp_le_set_advertisement_filter_enable {
	__u8 sub_opcode;
	__u8 enable;
} __packed;

struct msft_rp_le_set_advertisement_filter_enable {
	__u8 status;
	__u8 sub_opcode;
} __packed;

struct msft_monitor_advertisement_handle_data {
	__u8  msft_handle;
	__u16 mgmt_handle;
	struct list_head list;
};

struct msft_data {
	__u64 features;
	__u8  evt_prefix_len;
	__u8  *evt_prefix;
	struct list_head handle_map;
	__u16 pending_add_handle;
	__u16 pending_remove_handle;
	__u8 reregistering;
	__u8 filter_enabled;
};

static int __msft_add_monitor_pattern(struct hci_dev *hdev,
				      struct adv_monitor *monitor);

bool msft_monitor_supported(struct hci_dev *hdev)
{
	return !!(msft_get_features(hdev) & MSFT_FEATURE_MASK_LE_ADV_MONITOR);
}

static bool read_supported_features(struct hci_dev *hdev,
				    struct msft_data *msft)
{
	struct msft_cp_read_supported_features cp;
	struct msft_rp_read_supported_features *rp;
	struct sk_buff *skb;

	cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;

	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
			     HCI_CMD_TIMEOUT);
	if (IS_ERR(skb)) {
		bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)",
			   PTR_ERR(skb));
		return false;
	}

	if (skb->len < sizeof(*rp)) {
		bt_dev_err(hdev, "MSFT supported features length mismatch");
		goto failed;
	}

	rp = (struct msft_rp_read_supported_features *)skb->data;

	if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES)
		goto failed;

	if (rp->evt_prefix_len > 0) {
		msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
					   GFP_KERNEL);
		if (!msft->evt_prefix)
			goto failed;
	}

	msft->evt_prefix_len = rp->evt_prefix_len;
	msft->features = __le64_to_cpu(rp->features);

	kfree_skb(skb);
	return true;

failed:
	kfree_skb(skb);
	return false;
}

/* This function requires the caller holds hdev->lock */
static void reregister_monitor_on_restart(struct hci_dev *hdev, int handle)
{
	struct adv_monitor *monitor;
	struct msft_data *msft = hdev->msft_data;
	int err;

	while (1) {
		monitor = idr_get_next(&hdev->adv_monitors_idr, &handle);
		if (!monitor) {
			/* All monitors have been reregistered */
			msft->reregistering = false;
			hci_update_background_scan(hdev);
			return;
		}

		msft->pending_add_handle = (u16)handle;
		err = __msft_add_monitor_pattern(hdev, monitor);

		/* If success, we return and wait for monitor added callback */
		if (!err)
			return;

		/* Otherwise remove the monitor and keep registering */
		hci_free_adv_monitor(hdev, monitor);
		handle++;
	}
}

void msft_do_open(struct hci_dev *hdev)
{
	struct msft_data *msft;

	if (hdev->msft_opcode == HCI_OP_NOP)
		return;

	bt_dev_dbg(hdev, "Initialize MSFT extension");

	msft = kzalloc(sizeof(*msft), GFP_KERNEL);
	if (!msft)
		return;

	if (!read_supported_features(hdev, msft)) {
		kfree(msft);
		return;
	}

	INIT_LIST_HEAD(&msft->handle_map);
	hdev->msft_data = msft;

	if (msft_monitor_supported(hdev)) {
		msft->reregistering = true;
		msft_set_filter_enable(hdev, true);
		reregister_monitor_on_restart(hdev, 0);
	}
}

void msft_do_close(struct hci_dev *hdev)
{
	struct msft_data *msft = hdev->msft_data;
	struct msft_monitor_advertisement_handle_data *handle_data, *tmp;
	struct adv_monitor *monitor;

	if (!msft)
		return;

	bt_dev_dbg(hdev, "Cleanup of MSFT extension");

	hdev->msft_data = NULL;

	list_for_each_entry_safe(handle_data, tmp, &msft->handle_map, list) {
		monitor = idr_find(&hdev->adv_monitors_idr,
				   handle_data->mgmt_handle);

		if (monitor && monitor->state == ADV_MONITOR_STATE_OFFLOADED)
			monitor->state = ADV_MONITOR_STATE_REGISTERED;

		list_del(&handle_data->list);
		kfree(handle_data);
	}

	kfree(msft->evt_prefix);
	kfree(msft);
}

void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
	struct msft_data *msft = hdev->msft_data;
	u8 event;

	if (!msft)
		return;

	/* When the extension has defined an event prefix, check that it
	 * matches, and otherwise just return.
	 */
	if (msft->evt_prefix_len > 0) {
		if (skb->len < msft->evt_prefix_len)
			return;

		if (memcmp(skb->data, msft->evt_prefix, msft->evt_prefix_len))
			return;

		skb_pull(skb, msft->evt_prefix_len);
	}

	/* Every event starts at least with an event code and the rest of
	 * the data is variable and depends on the event code.
	 */
	if (skb->len < 1)
		return;

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

	bt_dev_dbg(hdev, "MSFT vendor event %u", event);
}

__u64 msft_get_features(struct hci_dev *hdev)
{
	struct msft_data *msft = hdev->msft_data;

	return msft ? msft->features : 0;
}

/* is_mgmt = true matches the handle exposed to userspace via mgmt.
 * is_mgmt = false matches the handle used by the msft controller.
 * This function requires the caller holds hdev->lock
 */
static struct msft_monitor_advertisement_handle_data *msft_find_handle_data
				(struct hci_dev *hdev, u16 handle, bool is_mgmt)
{
	struct msft_monitor_advertisement_handle_data *entry;
	struct msft_data *msft = hdev->msft_data;

	list_for_each_entry(entry, &msft->handle_map, list) {
		if (is_mgmt && entry->mgmt_handle == handle)
			return entry;
		if (!is_mgmt && entry->msft_handle == handle)
			return entry;
	}

	return NULL;
}

static void msft_le_monitor_advertisement_cb(struct hci_dev *hdev,
					     u8 status, u16 opcode,
					     struct sk_buff *skb)
{
	struct msft_rp_le_monitor_advertisement *rp;
	struct adv_monitor *monitor;
	struct msft_monitor_advertisement_handle_data *handle_data;
	struct msft_data *msft = hdev->msft_data;

	hci_dev_lock(hdev);

	monitor = idr_find(&hdev->adv_monitors_idr, msft->pending_add_handle);
	if (!monitor) {
		bt_dev_err(hdev, "msft add advmon: monitor %d is not found!",
			   msft->pending_add_handle);
		status = HCI_ERROR_UNSPECIFIED;
		goto unlock;
	}

	if (status)
		goto unlock;

	rp = (struct msft_rp_le_monitor_advertisement *)skb->data;
	if (skb->len < sizeof(*rp)) {
		status = HCI_ERROR_UNSPECIFIED;
		goto unlock;
	}

	handle_data = kmalloc(sizeof(*handle_data), GFP_KERNEL);
	if (!handle_data) {
		status = HCI_ERROR_UNSPECIFIED;
		goto unlock;
	}

	handle_data->mgmt_handle = monitor->handle;
	handle_data->msft_handle = rp->handle;
	INIT_LIST_HEAD(&handle_data->list);
	list_add(&handle_data->list, &msft->handle_map);

	monitor->state = ADV_MONITOR_STATE_OFFLOADED;

unlock:
	if (status && monitor)
		hci_free_adv_monitor(hdev, monitor);

	/* If in restart/reregister sequence, keep registering. */
	if (msft->reregistering)
		reregister_monitor_on_restart(hdev,
					      msft->pending_add_handle + 1);

	hci_dev_unlock(hdev);

	if (!msft->reregistering)
		hci_add_adv_patterns_monitor_complete(hdev, status);
}

static void msft_le_cancel_monitor_advertisement_cb(struct hci_dev *hdev,
						    u8 status, u16 opcode,
						    struct sk_buff *skb)
{
	struct msft_cp_le_cancel_monitor_advertisement *cp;
	struct msft_rp_le_cancel_monitor_advertisement *rp;
	struct adv_monitor *monitor;
	struct msft_monitor_advertisement_handle_data *handle_data;
	struct msft_data *msft = hdev->msft_data;
	int err;
	bool pending;

	if (status)
		goto done;

	rp = (struct msft_rp_le_cancel_monitor_advertisement *)skb->data;
	if (skb->len < sizeof(*rp)) {
		status = HCI_ERROR_UNSPECIFIED;
		goto done;
	}

	hci_dev_lock(hdev);

	cp = hci_sent_cmd_data(hdev, hdev->msft_opcode);
	handle_data = msft_find_handle_data(hdev, cp->handle, false);

	if (handle_data) {
		monitor = idr_find(&hdev->adv_monitors_idr,
				   handle_data->mgmt_handle);
		if (monitor)
			hci_free_adv_monitor(hdev, monitor);

		list_del(&handle_data->list);
		kfree(handle_data);
	}

	/* If remove all monitors is required, we need to continue the process
	 * here because the earlier it was paused when waiting for the
	 * response from controller.
	 */
	if (msft->pending_remove_handle == 0) {
		pending = hci_remove_all_adv_monitor(hdev, &err);
		if (pending) {
			hci_dev_unlock(hdev);
			return;
		}

		if (err)
			status = HCI_ERROR_UNSPECIFIED;
	}

	hci_dev_unlock(hdev);

done:
	hci_remove_adv_monitor_complete(hdev, status);
}

static void msft_le_set_advertisement_filter_enable_cb(struct hci_dev *hdev,
						       u8 status, u16 opcode,
						       struct sk_buff *skb)
{
	struct msft_cp_le_set_advertisement_filter_enable *cp;
	struct msft_rp_le_set_advertisement_filter_enable *rp;
	struct msft_data *msft = hdev->msft_data;

	rp = (struct msft_rp_le_set_advertisement_filter_enable *)skb->data;
	if (skb->len < sizeof(*rp))
		return;

	/* Error 0x0C would be returned if the filter enabled status is
	 * already set to whatever we were trying to set.
	 * Although the default state should be disabled, some controller set
	 * the initial value to enabled. Because there is no way to know the
	 * actual initial value before sending this command, here we also treat
	 * error 0x0C as success.
	 */
	if (status != 0x00 && status != 0x0C)
		return;

	hci_dev_lock(hdev);

	cp = hci_sent_cmd_data(hdev, hdev->msft_opcode);
	msft->filter_enabled = cp->enable;

	if (status == 0x0C)
		bt_dev_warn(hdev, "MSFT filter_enable is already %s",
			    cp->enable ? "on" : "off");

	hci_dev_unlock(hdev);
}

static bool msft_monitor_rssi_valid(struct adv_monitor *monitor)
{
	struct adv_rssi_thresholds *r = &monitor->rssi;

	if (r->high_threshold < MSFT_RSSI_THRESHOLD_VALUE_MIN ||
	    r->high_threshold > MSFT_RSSI_THRESHOLD_VALUE_MAX ||
	    r->low_threshold < MSFT_RSSI_THRESHOLD_VALUE_MIN ||
	    r->low_threshold > MSFT_RSSI_THRESHOLD_VALUE_MAX)
		return false;

	/* High_threshold_timeout is not supported,
	 * once high_threshold is reached, events are immediately reported.
	 */
	if (r->high_threshold_timeout != 0)
		return false;

	if (r->low_threshold_timeout > MSFT_RSSI_LOW_TIMEOUT_MAX)
		return false;

	/* Sampling period from 0x00 to 0xFF are all allowed */
	return true;
}

static bool msft_monitor_pattern_valid(struct adv_monitor *monitor)
{
	return msft_monitor_rssi_valid(monitor);
	/* No additional check needed for pattern-based monitor */
}

/* This function requires the caller holds hdev->lock */
static int __msft_add_monitor_pattern(struct hci_dev *hdev,
				      struct adv_monitor *monitor)
{
	struct msft_cp_le_monitor_advertisement *cp;
	struct msft_le_monitor_advertisement_pattern_data *pattern_data;
	struct msft_le_monitor_advertisement_pattern *pattern;
	struct adv_pattern *entry;
	struct hci_request req;
	struct msft_data *msft = hdev->msft_data;
	size_t total_size = sizeof(*cp) + sizeof(*pattern_data);
	ptrdiff_t offset = 0;
	u8 pattern_count = 0;
	int err = 0;

	if (!msft_monitor_pattern_valid(monitor))
		return -EINVAL;

	list_for_each_entry(entry, &monitor->patterns, list) {
		pattern_count++;
		total_size += sizeof(*pattern) + entry->length;
	}

	cp = kmalloc(total_size, GFP_KERNEL);
	if (!cp)
		return -ENOMEM;

	cp->sub_opcode = MSFT_OP_LE_MONITOR_ADVERTISEMENT;
	cp->rssi_high = monitor->rssi.high_threshold;
	cp->rssi_low = monitor->rssi.low_threshold;
	cp->rssi_low_interval = (u8)monitor->rssi.low_threshold_timeout;
	cp->rssi_sampling_period = monitor->rssi.sampling_period;

	cp->cond_type = MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN;

	pattern_data = (void *)cp->data;
	pattern_data->count = pattern_count;

	list_for_each_entry(entry, &monitor->patterns, list) {
		pattern = (void *)(pattern_data->data + offset);
		/* the length also includes data_type and offset */
		pattern->length = entry->length + 2;
		pattern->data_type = entry->ad_type;
		pattern->start_byte = entry->offset;
		memcpy(pattern->pattern, entry->value, entry->length);
		offset += sizeof(*pattern) + entry->length;
	}

	hci_req_init(&req, hdev);
	hci_req_add(&req, hdev->msft_opcode, total_size, cp);
	err = hci_req_run_skb(&req, msft_le_monitor_advertisement_cb);
	kfree(cp);

	if (!err)
		msft->pending_add_handle = monitor->handle;

	return err;
}

/* This function requires the caller holds hdev->lock */
int msft_add_monitor_pattern(struct hci_dev *hdev, struct adv_monitor *monitor)
{
	struct msft_data *msft = hdev->msft_data;

	if (!msft)
		return -EOPNOTSUPP;

	if (msft->reregistering)
		return -EBUSY;

	return __msft_add_monitor_pattern(hdev, monitor);
}

/* This function requires the caller holds hdev->lock */
int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
			u16 handle)
{
	struct msft_cp_le_cancel_monitor_advertisement cp;
	struct msft_monitor_advertisement_handle_data *handle_data;
	struct hci_request req;
	struct msft_data *msft = hdev->msft_data;
	int err = 0;

	if (!msft)
		return -EOPNOTSUPP;

	if (msft->reregistering)
		return -EBUSY;

	handle_data = msft_find_handle_data(hdev, monitor->handle, true);

	/* If no matched handle, just remove without telling controller */
	if (!handle_data)
		return -ENOENT;

	cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
	cp.handle = handle_data->msft_handle;

	hci_req_init(&req, hdev);
	hci_req_add(&req, hdev->msft_opcode, sizeof(cp), &cp);
	err = hci_req_run_skb(&req, msft_le_cancel_monitor_advertisement_cb);

	if (!err)
		msft->pending_remove_handle = handle;

	return err;
}

void msft_req_add_set_filter_enable(struct hci_request *req, bool enable)
{
	struct hci_dev *hdev = req->hdev;
	struct msft_cp_le_set_advertisement_filter_enable cp;

	cp.sub_opcode = MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE;
	cp.enable = enable;

	hci_req_add(req, hdev->msft_opcode, sizeof(cp), &cp);
}

int msft_set_filter_enable(struct hci_dev *hdev, bool enable)
{
	struct hci_request req;
	struct msft_data *msft = hdev->msft_data;
	int err;

	if (!msft)
		return -EOPNOTSUPP;

	hci_req_init(&req, hdev);
	msft_req_add_set_filter_enable(&req, enable);
	err = hci_req_run_skb(&req, msft_le_set_advertisement_filter_enable_cb);

	return err;
}