xref: /linux/net/bluetooth/msft.c (revision cf85f810f911234a06a4ef2439e8694b93b717fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2020 Google Corporation
4  */
5 
6 #include <net/bluetooth/bluetooth.h>
7 #include <net/bluetooth/hci_core.h>
8 #include <net/bluetooth/mgmt.h>
9 
10 #include "mgmt_util.h"
11 #include "msft.h"
12 
13 #define MSFT_RSSI_THRESHOLD_VALUE_MIN		-127
14 #define MSFT_RSSI_THRESHOLD_VALUE_MAX		20
15 #define MSFT_RSSI_LOW_TIMEOUT_MAX		0x3C
16 
17 #define MSFT_OP_READ_SUPPORTED_FEATURES		0x00
18 struct msft_cp_read_supported_features {
19 	__u8   sub_opcode;
20 } __packed;
21 
22 struct msft_rp_read_supported_features {
23 	__u8   status;
24 	__u8   sub_opcode;
25 	__le64 features;
26 	__u8   evt_prefix_len;
27 	__u8   evt_prefix[];
28 } __packed;
29 
30 #define MSFT_OP_LE_MONITOR_ADVERTISEMENT	0x03
31 #define MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN	0x01
32 struct msft_le_monitor_advertisement_pattern {
33 	__u8 length;
34 	__u8 data_type;
35 	__u8 start_byte;
36 	__u8 pattern[];
37 };
38 
39 struct msft_le_monitor_advertisement_pattern_data {
40 	__u8 count;
41 	__u8 data[];
42 };
43 
44 struct msft_cp_le_monitor_advertisement {
45 	__u8 sub_opcode;
46 	__s8 rssi_high;
47 	__s8 rssi_low;
48 	__u8 rssi_low_interval;
49 	__u8 rssi_sampling_period;
50 	__u8 cond_type;
51 	__u8 data[];
52 } __packed;
53 
54 struct msft_rp_le_monitor_advertisement {
55 	__u8 status;
56 	__u8 sub_opcode;
57 	__u8 handle;
58 } __packed;
59 
60 #define MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT	0x04
61 struct msft_cp_le_cancel_monitor_advertisement {
62 	__u8 sub_opcode;
63 	__u8 handle;
64 } __packed;
65 
66 struct msft_rp_le_cancel_monitor_advertisement {
67 	__u8 status;
68 	__u8 sub_opcode;
69 } __packed;
70 
71 #define MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE	0x05
72 struct msft_cp_le_set_advertisement_filter_enable {
73 	__u8 sub_opcode;
74 	__u8 enable;
75 } __packed;
76 
77 struct msft_rp_le_set_advertisement_filter_enable {
78 	__u8 status;
79 	__u8 sub_opcode;
80 } __packed;
81 
82 #define MSFT_EV_LE_MONITOR_DEVICE	0x02
83 struct msft_ev_le_monitor_device {
84 	__u8     addr_type;
85 	bdaddr_t bdaddr;
86 	__u8     monitor_handle;
87 	__u8     monitor_state;
88 } __packed;
89 
90 struct msft_monitor_advertisement_handle_data {
91 	__u8  msft_handle;
92 	__u16 mgmt_handle;
93 	__s8 rssi_high;
94 	__s8 rssi_low;
95 	__u8 rssi_low_interval;
96 	__u8 rssi_sampling_period;
97 	__u8 cond_type;
98 	struct list_head list;
99 };
100 
101 enum monitor_addr_filter_state {
102 	AF_STATE_IDLE,
103 	AF_STATE_ADDING,
104 	AF_STATE_ADDED,
105 	AF_STATE_REMOVING,
106 };
107 
108 #define MSFT_MONITOR_ADVERTISEMENT_TYPE_ADDR	0x04
109 struct msft_monitor_addr_filter_data {
110 	__u8     msft_handle;
111 	__u8     pattern_handle; /* address filters pertain to */
112 	__u16    mgmt_handle;
113 	int      state;
114 	__s8     rssi_high;
115 	__s8     rssi_low;
116 	__u8     rssi_low_interval;
117 	__u8     rssi_sampling_period;
118 	__u8     addr_type;
119 	bdaddr_t bdaddr;
120 	struct list_head list;
121 };
122 
123 struct msft_data {
124 	__u64 features;
125 	__u8  evt_prefix_len;
126 	__u8  *evt_prefix;
127 	struct list_head handle_map;
128 	struct list_head address_filters;
129 	__u8 resuming;
130 	__u8 suspending;
131 	__u8 filter_enabled;
132 	/* To synchronize add/remove address filter and monitor device event.*/
133 	struct mutex filter_lock;
134 };
135 
136 bool msft_monitor_supported(struct hci_dev *hdev)
137 {
138 	return !!(msft_get_features(hdev) & MSFT_FEATURE_MASK_LE_ADV_MONITOR);
139 }
140 
141 static bool read_supported_features(struct hci_dev *hdev,
142 				    struct msft_data *msft)
143 {
144 	struct msft_cp_read_supported_features cp;
145 	struct msft_rp_read_supported_features *rp;
146 	struct sk_buff *skb;
147 
148 	cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;
149 
150 	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
151 			     HCI_CMD_TIMEOUT);
152 	if (IS_ERR(skb)) {
153 		bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)",
154 			   PTR_ERR(skb));
155 		return false;
156 	}
157 
158 	if (skb->len < sizeof(*rp)) {
159 		bt_dev_err(hdev, "MSFT supported features length mismatch");
160 		goto failed;
161 	}
162 
163 	rp = (struct msft_rp_read_supported_features *)skb->data;
164 
165 	if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES)
166 		goto failed;
167 
168 	if (skb->len < sizeof(*rp) + rp->evt_prefix_len) {
169 		bt_dev_err(hdev, "MSFT event prefix length mismatch");
170 		goto failed;
171 	}
172 
173 	if (rp->evt_prefix_len > 0) {
174 		msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
175 					   GFP_KERNEL);
176 		if (!msft->evt_prefix)
177 			goto failed;
178 	}
179 
180 	msft->evt_prefix_len = rp->evt_prefix_len;
181 	msft->features = __le64_to_cpu(rp->features);
182 
183 	if (msft->features & MSFT_FEATURE_MASK_CURVE_VALIDITY)
184 		hdev->msft_curve_validity = true;
185 
186 	kfree_skb(skb);
187 	return true;
188 
189 failed:
190 	kfree_skb(skb);
191 	return false;
192 }
193 
194 /* is_mgmt = true matches the handle exposed to userspace via mgmt.
195  * is_mgmt = false matches the handle used by the msft controller.
196  * This function requires the caller holds hdev->lock
197  */
198 static struct msft_monitor_advertisement_handle_data *msft_find_handle_data
199 				(struct hci_dev *hdev, u16 handle, bool is_mgmt)
200 {
201 	struct msft_monitor_advertisement_handle_data *entry;
202 	struct msft_data *msft = hdev->msft_data;
203 
204 	list_for_each_entry(entry, &msft->handle_map, list) {
205 		if (is_mgmt && entry->mgmt_handle == handle)
206 			return entry;
207 		if (!is_mgmt && entry->msft_handle == handle)
208 			return entry;
209 	}
210 
211 	return NULL;
212 }
213 
214 /* This function requires the caller holds msft->filter_lock */
215 static struct msft_monitor_addr_filter_data *msft_find_address_data
216 			(struct hci_dev *hdev, u8 addr_type, bdaddr_t *addr,
217 			 u8 pattern_handle)
218 {
219 	struct msft_monitor_addr_filter_data *entry;
220 	struct msft_data *msft = hdev->msft_data;
221 
222 	list_for_each_entry(entry, &msft->address_filters, list) {
223 		if (entry->pattern_handle == pattern_handle &&
224 		    addr_type == entry->addr_type &&
225 		    !bacmp(addr, &entry->bdaddr))
226 			return entry;
227 	}
228 
229 	return NULL;
230 }
231 
232 /* This function requires the caller holds hdev->lock */
233 static int msft_monitor_device_del(struct hci_dev *hdev, __u16 mgmt_handle,
234 				   bdaddr_t *bdaddr, __u8 addr_type,
235 				   bool notify)
236 {
237 	struct monitored_device *dev, *tmp;
238 	int count = 0;
239 
240 	list_for_each_entry_safe(dev, tmp, &hdev->monitored_devices, list) {
241 		/* mgmt_handle == 0 indicates remove all devices, whereas,
242 		 * bdaddr == NULL indicates remove all devices matching the
243 		 * mgmt_handle.
244 		 */
245 		if ((!mgmt_handle || dev->handle == mgmt_handle) &&
246 		    (!bdaddr || (!bacmp(bdaddr, &dev->bdaddr) &&
247 				 addr_type == dev->addr_type))) {
248 			if (notify && dev->notified) {
249 				mgmt_adv_monitor_device_lost(hdev, dev->handle,
250 							     &dev->bdaddr,
251 							     dev->addr_type);
252 			}
253 
254 			list_del(&dev->list);
255 			kfree(dev);
256 			count++;
257 		}
258 	}
259 
260 	return count;
261 }
262 
263 static int msft_le_monitor_advertisement_cb(struct hci_dev *hdev, u16 opcode,
264 					    struct adv_monitor *monitor,
265 					    struct sk_buff *skb)
266 {
267 	struct msft_rp_le_monitor_advertisement *rp;
268 	struct msft_monitor_advertisement_handle_data *handle_data;
269 	struct msft_data *msft = hdev->msft_data;
270 	int status = 0;
271 
272 	hci_dev_lock(hdev);
273 
274 	rp = (struct msft_rp_le_monitor_advertisement *)skb->data;
275 	if (skb->len < sizeof(*rp)) {
276 		status = HCI_ERROR_UNSPECIFIED;
277 		goto unlock;
278 	}
279 
280 	status = rp->status;
281 	if (status)
282 		goto unlock;
283 
284 	handle_data = kmalloc_obj(*handle_data);
285 	if (!handle_data) {
286 		status = HCI_ERROR_UNSPECIFIED;
287 		goto unlock;
288 	}
289 
290 	handle_data->mgmt_handle = monitor->handle;
291 	handle_data->msft_handle = rp->handle;
292 	handle_data->cond_type   = MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN;
293 	INIT_LIST_HEAD(&handle_data->list);
294 	list_add(&handle_data->list, &msft->handle_map);
295 
296 	monitor->state = ADV_MONITOR_STATE_OFFLOADED;
297 
298 unlock:
299 	if (status && msft->resuming)
300 		hci_free_adv_monitor(hdev, monitor);
301 
302 	hci_dev_unlock(hdev);
303 
304 	return status;
305 }
306 
307 /* This function requires the caller holds hci_req_sync_lock */
308 static void msft_remove_addr_filters_sync(struct hci_dev *hdev, u8 handle)
309 {
310 	struct msft_monitor_addr_filter_data *address_filter, *n;
311 	struct msft_cp_le_cancel_monitor_advertisement cp;
312 	struct msft_data *msft = hdev->msft_data;
313 	struct list_head head;
314 	struct sk_buff *skb;
315 
316 	INIT_LIST_HEAD(&head);
317 
318 	/* Cancel all corresponding address monitors */
319 	mutex_lock(&msft->filter_lock);
320 
321 	list_for_each_entry_safe(address_filter, n, &msft->address_filters,
322 				 list) {
323 		if (address_filter->pattern_handle != handle)
324 			continue;
325 
326 		list_del(&address_filter->list);
327 
328 		/* Keep the address filter and let
329 		 * msft_add_address_filter_sync() remove and free the address
330 		 * filter.
331 		 */
332 		if (address_filter->state == AF_STATE_ADDING) {
333 			address_filter->state = AF_STATE_REMOVING;
334 			continue;
335 		}
336 
337 		/* Keep the address filter and let
338 		 * msft_cancel_address_filter_sync() remove and free the address
339 		 * filter
340 		 */
341 		if (address_filter->state == AF_STATE_REMOVING)
342 			continue;
343 
344 		list_add_tail(&address_filter->list, &head);
345 	}
346 
347 	mutex_unlock(&msft->filter_lock);
348 
349 	list_for_each_entry_safe(address_filter, n, &head, list) {
350 		list_del(&address_filter->list);
351 
352 		cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
353 		cp.handle = address_filter->msft_handle;
354 
355 		skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
356 				     HCI_CMD_TIMEOUT);
357 		if (IS_ERR(skb)) {
358 			kfree(address_filter);
359 			continue;
360 		}
361 
362 		kfree_skb(skb);
363 
364 		bt_dev_dbg(hdev, "MSFT: Canceled device %pMR address filter",
365 			   &address_filter->bdaddr);
366 
367 		kfree(address_filter);
368 	}
369 }
370 
371 static int msft_le_cancel_monitor_advertisement_cb(struct hci_dev *hdev,
372 						   u16 opcode,
373 						   struct adv_monitor *monitor,
374 						   struct sk_buff *skb)
375 {
376 	struct msft_rp_le_cancel_monitor_advertisement *rp;
377 	struct msft_monitor_advertisement_handle_data *handle_data;
378 	struct msft_data *msft = hdev->msft_data;
379 	int status = 0;
380 	u8 msft_handle;
381 
382 	rp = (struct msft_rp_le_cancel_monitor_advertisement *)skb->data;
383 	if (skb->len < sizeof(*rp)) {
384 		status = HCI_ERROR_UNSPECIFIED;
385 		goto done;
386 	}
387 
388 	status = rp->status;
389 	if (status)
390 		goto done;
391 
392 	hci_dev_lock(hdev);
393 
394 	handle_data = msft_find_handle_data(hdev, monitor->handle, true);
395 
396 	if (handle_data) {
397 		if (monitor->state == ADV_MONITOR_STATE_OFFLOADED)
398 			monitor->state = ADV_MONITOR_STATE_REGISTERED;
399 
400 		/* Do not free the monitor if it is being removed due to
401 		 * suspend. It will be re-monitored on resume.
402 		 */
403 		if (!msft->suspending) {
404 			hci_free_adv_monitor(hdev, monitor);
405 
406 			/* Clear any monitored devices by this Adv Monitor */
407 			msft_monitor_device_del(hdev, handle_data->mgmt_handle,
408 						NULL, 0, false);
409 		}
410 
411 		msft_handle = handle_data->msft_handle;
412 
413 		list_del(&handle_data->list);
414 		kfree(handle_data);
415 
416 		hci_dev_unlock(hdev);
417 
418 		msft_remove_addr_filters_sync(hdev, msft_handle);
419 	} else {
420 		hci_dev_unlock(hdev);
421 	}
422 
423 done:
424 	return status;
425 }
426 
427 /* This function requires the caller holds hci_req_sync_lock */
428 static int msft_remove_monitor_sync(struct hci_dev *hdev,
429 				    struct adv_monitor *monitor)
430 {
431 	struct msft_cp_le_cancel_monitor_advertisement cp;
432 	struct msft_monitor_advertisement_handle_data *handle_data;
433 	struct sk_buff *skb;
434 
435 	handle_data = msft_find_handle_data(hdev, monitor->handle, true);
436 
437 	/* If no matched handle, just remove without telling controller */
438 	if (!handle_data)
439 		return -ENOENT;
440 
441 	cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
442 	cp.handle = handle_data->msft_handle;
443 
444 	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
445 			     HCI_CMD_TIMEOUT);
446 	if (IS_ERR(skb))
447 		return PTR_ERR(skb);
448 
449 	return msft_le_cancel_monitor_advertisement_cb(hdev, hdev->msft_opcode,
450 						       monitor, skb);
451 }
452 
453 /* This function requires the caller holds hci_req_sync_lock */
454 int msft_suspend_sync(struct hci_dev *hdev)
455 {
456 	struct msft_data *msft = hdev->msft_data;
457 	struct adv_monitor *monitor;
458 	int handle = 0;
459 
460 	if (!msft || !msft_monitor_supported(hdev))
461 		return 0;
462 
463 	msft->suspending = true;
464 
465 	while (1) {
466 		monitor = idr_get_next(&hdev->adv_monitors_idr, &handle);
467 		if (!monitor)
468 			break;
469 
470 		msft_remove_monitor_sync(hdev, monitor);
471 
472 		handle++;
473 	}
474 
475 	/* All monitors have been removed */
476 	msft->suspending = false;
477 
478 	return 0;
479 }
480 
481 static bool msft_monitor_rssi_valid(struct adv_monitor *monitor)
482 {
483 	struct adv_rssi_thresholds *r = &monitor->rssi;
484 
485 	if (r->high_threshold < MSFT_RSSI_THRESHOLD_VALUE_MIN ||
486 	    r->high_threshold > MSFT_RSSI_THRESHOLD_VALUE_MAX ||
487 	    r->low_threshold < MSFT_RSSI_THRESHOLD_VALUE_MIN ||
488 	    r->low_threshold > MSFT_RSSI_THRESHOLD_VALUE_MAX)
489 		return false;
490 
491 	/* High_threshold_timeout is not supported,
492 	 * once high_threshold is reached, events are immediately reported.
493 	 */
494 	if (r->high_threshold_timeout != 0)
495 		return false;
496 
497 	if (r->low_threshold_timeout > MSFT_RSSI_LOW_TIMEOUT_MAX)
498 		return false;
499 
500 	/* Sampling period from 0x00 to 0xFF are all allowed */
501 	return true;
502 }
503 
504 static bool msft_monitor_pattern_valid(struct adv_monitor *monitor)
505 {
506 	return msft_monitor_rssi_valid(monitor);
507 	/* No additional check needed for pattern-based monitor */
508 }
509 
510 static int msft_add_monitor_sync(struct hci_dev *hdev,
511 				 struct adv_monitor *monitor)
512 {
513 	struct msft_cp_le_monitor_advertisement *cp;
514 	struct msft_le_monitor_advertisement_pattern_data *pattern_data;
515 	struct msft_monitor_advertisement_handle_data *handle_data;
516 	struct msft_le_monitor_advertisement_pattern *pattern;
517 	struct adv_pattern *entry;
518 	size_t total_size = sizeof(*cp) + sizeof(*pattern_data);
519 	ptrdiff_t offset = 0;
520 	u8 pattern_count = 0;
521 	struct sk_buff *skb;
522 	int err;
523 
524 	if (!msft_monitor_pattern_valid(monitor))
525 		return -EINVAL;
526 
527 	list_for_each_entry(entry, &monitor->patterns, list) {
528 		pattern_count++;
529 		total_size += sizeof(*pattern) + entry->length;
530 	}
531 
532 	cp = kmalloc(total_size, GFP_KERNEL);
533 	if (!cp)
534 		return -ENOMEM;
535 
536 	cp->sub_opcode = MSFT_OP_LE_MONITOR_ADVERTISEMENT;
537 	cp->rssi_high = monitor->rssi.high_threshold;
538 	cp->rssi_low = monitor->rssi.low_threshold;
539 	cp->rssi_low_interval = (u8)monitor->rssi.low_threshold_timeout;
540 	cp->rssi_sampling_period = monitor->rssi.sampling_period;
541 
542 	cp->cond_type = MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN;
543 
544 	pattern_data = (void *)cp->data;
545 	pattern_data->count = pattern_count;
546 
547 	list_for_each_entry(entry, &monitor->patterns, list) {
548 		pattern = (void *)(pattern_data->data + offset);
549 		/* the length also includes data_type and offset */
550 		pattern->length = entry->length + 2;
551 		pattern->data_type = entry->ad_type;
552 		pattern->start_byte = entry->offset;
553 		memcpy(pattern->pattern, entry->value, entry->length);
554 		offset += sizeof(*pattern) + entry->length;
555 	}
556 
557 	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, total_size, cp,
558 			     HCI_CMD_TIMEOUT);
559 
560 	if (IS_ERR(skb)) {
561 		err = PTR_ERR(skb);
562 		goto out_free;
563 	}
564 
565 	err = msft_le_monitor_advertisement_cb(hdev, hdev->msft_opcode,
566 					       monitor, skb);
567 	if (err)
568 		goto out_free;
569 
570 	handle_data = msft_find_handle_data(hdev, monitor->handle, true);
571 	if (!handle_data) {
572 		err = -ENODATA;
573 		goto out_free;
574 	}
575 
576 	handle_data->rssi_high	= cp->rssi_high;
577 	handle_data->rssi_low	= cp->rssi_low;
578 	handle_data->rssi_low_interval	  = cp->rssi_low_interval;
579 	handle_data->rssi_sampling_period = cp->rssi_sampling_period;
580 
581 out_free:
582 	kfree(cp);
583 	return err;
584 }
585 
586 /* This function requires the caller holds hci_req_sync_lock */
587 static void reregister_monitor(struct hci_dev *hdev)
588 {
589 	struct adv_monitor *monitor;
590 	struct msft_data *msft = hdev->msft_data;
591 	int handle = 0;
592 
593 	if (!msft)
594 		return;
595 
596 	msft->resuming = true;
597 
598 	while (1) {
599 		monitor = idr_get_next(&hdev->adv_monitors_idr, &handle);
600 		if (!monitor)
601 			break;
602 
603 		msft_add_monitor_sync(hdev, monitor);
604 
605 		handle++;
606 	}
607 
608 	/* All monitors have been reregistered */
609 	msft->resuming = false;
610 }
611 
612 /* This function requires the caller holds hci_req_sync_lock */
613 int msft_resume_sync(struct hci_dev *hdev)
614 {
615 	struct msft_data *msft = hdev->msft_data;
616 
617 	if (!msft || !msft_monitor_supported(hdev))
618 		return 0;
619 
620 	hci_dev_lock(hdev);
621 
622 	/* Clear already tracked devices on resume. Once the monitors are
623 	 * reregistered, devices in range will be found again after resume.
624 	 */
625 	hdev->advmon_pend_notify = false;
626 	msft_monitor_device_del(hdev, 0, NULL, 0, true);
627 
628 	hci_dev_unlock(hdev);
629 
630 	reregister_monitor(hdev);
631 
632 	return 0;
633 }
634 
635 /* This function requires the caller holds hci_req_sync_lock */
636 void msft_do_open(struct hci_dev *hdev)
637 {
638 	struct msft_data *msft = hdev->msft_data;
639 
640 	if (hdev->msft_opcode == HCI_OP_NOP)
641 		return;
642 
643 	if (!msft) {
644 		bt_dev_err(hdev, "MSFT extension not registered");
645 		return;
646 	}
647 
648 	bt_dev_dbg(hdev, "Initialize MSFT extension");
649 
650 	/* Reset existing MSFT data before re-reading */
651 	kfree(msft->evt_prefix);
652 	msft->evt_prefix = NULL;
653 	msft->evt_prefix_len = 0;
654 	msft->features = 0;
655 
656 	if (!read_supported_features(hdev, msft)) {
657 		hdev->msft_data = NULL;
658 		kfree(msft);
659 		return;
660 	}
661 
662 	if (msft_monitor_supported(hdev)) {
663 		msft->resuming = true;
664 		msft_set_filter_enable(hdev, true);
665 		/* Monitors get removed on power off, so we need to explicitly
666 		 * tell the controller to re-monitor.
667 		 */
668 		reregister_monitor(hdev);
669 	}
670 }
671 
672 void msft_do_close(struct hci_dev *hdev)
673 {
674 	struct msft_data *msft = hdev->msft_data;
675 	struct msft_monitor_advertisement_handle_data *handle_data, *tmp;
676 	struct msft_monitor_addr_filter_data *address_filter, *n;
677 	struct adv_monitor *monitor;
678 
679 	if (!msft)
680 		return;
681 
682 	bt_dev_dbg(hdev, "Cleanup of MSFT extension");
683 
684 	/* The controller will silently remove all monitors on power off.
685 	 * Therefore, remove handle_data mapping and reset monitor state.
686 	 */
687 	list_for_each_entry_safe(handle_data, tmp, &msft->handle_map, list) {
688 		monitor = idr_find(&hdev->adv_monitors_idr,
689 				   handle_data->mgmt_handle);
690 
691 		if (monitor && monitor->state == ADV_MONITOR_STATE_OFFLOADED)
692 			monitor->state = ADV_MONITOR_STATE_REGISTERED;
693 
694 		list_del(&handle_data->list);
695 		kfree(handle_data);
696 	}
697 
698 	mutex_lock(&msft->filter_lock);
699 	list_for_each_entry_safe(address_filter, n, &msft->address_filters,
700 				 list) {
701 		list_del(&address_filter->list);
702 		kfree(address_filter);
703 	}
704 	mutex_unlock(&msft->filter_lock);
705 
706 	hci_dev_lock(hdev);
707 
708 	/* Clear any devices that are being monitored and notify device lost */
709 	hdev->advmon_pend_notify = false;
710 	msft_monitor_device_del(hdev, 0, NULL, 0, true);
711 
712 	hci_dev_unlock(hdev);
713 }
714 
715 static int msft_cancel_address_filter_sync(struct hci_dev *hdev, void *data)
716 {
717 	struct msft_monitor_addr_filter_data *address_filter = data;
718 	struct msft_cp_le_cancel_monitor_advertisement cp;
719 	struct msft_data *msft = hdev->msft_data;
720 	struct sk_buff *skb;
721 	int err = 0;
722 
723 	if (!msft) {
724 		bt_dev_err(hdev, "MSFT: msft data is freed");
725 		return -EINVAL;
726 	}
727 
728 	/* The address filter has been removed by hci dev close */
729 	if (!test_bit(HCI_UP, &hdev->flags))
730 		return 0;
731 
732 	mutex_lock(&msft->filter_lock);
733 	list_del(&address_filter->list);
734 	mutex_unlock(&msft->filter_lock);
735 
736 	cp.sub_opcode = MSFT_OP_LE_CANCEL_MONITOR_ADVERTISEMENT;
737 	cp.handle = address_filter->msft_handle;
738 
739 	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
740 			     HCI_CMD_TIMEOUT);
741 	if (IS_ERR(skb)) {
742 		bt_dev_err(hdev, "MSFT: Failed to cancel address (%pMR) filter",
743 			   &address_filter->bdaddr);
744 		err = PTR_ERR(skb);
745 		goto done;
746 	}
747 	kfree_skb(skb);
748 
749 	bt_dev_dbg(hdev, "MSFT: Canceled device %pMR address filter",
750 		   &address_filter->bdaddr);
751 
752 done:
753 	kfree(address_filter);
754 
755 	return err;
756 }
757 
758 void msft_register(struct hci_dev *hdev)
759 {
760 	struct msft_data *msft = NULL;
761 
762 	bt_dev_dbg(hdev, "Register MSFT extension");
763 
764 	msft = kzalloc_obj(*msft);
765 	if (!msft) {
766 		bt_dev_err(hdev, "Failed to register MSFT extension");
767 		return;
768 	}
769 
770 	INIT_LIST_HEAD(&msft->handle_map);
771 	INIT_LIST_HEAD(&msft->address_filters);
772 	hdev->msft_data = msft;
773 	mutex_init(&msft->filter_lock);
774 }
775 
776 void msft_release(struct hci_dev *hdev)
777 {
778 	struct msft_data *msft = hdev->msft_data;
779 
780 	if (!msft)
781 		return;
782 
783 	bt_dev_dbg(hdev, "Unregister MSFT extension");
784 
785 	hdev->msft_data = NULL;
786 
787 	kfree(msft->evt_prefix);
788 	mutex_destroy(&msft->filter_lock);
789 	kfree(msft);
790 }
791 
792 /* This function requires the caller holds hdev->lock */
793 static void msft_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr,
794 			      __u8 addr_type, __u16 mgmt_handle)
795 {
796 	struct monitored_device *dev;
797 
798 	dev = kmalloc_obj(*dev);
799 	if (!dev) {
800 		bt_dev_err(hdev, "MSFT vendor event %u: no memory",
801 			   MSFT_EV_LE_MONITOR_DEVICE);
802 		return;
803 	}
804 
805 	bacpy(&dev->bdaddr, bdaddr);
806 	dev->addr_type = addr_type;
807 	dev->handle = mgmt_handle;
808 	dev->notified = false;
809 
810 	INIT_LIST_HEAD(&dev->list);
811 	list_add(&dev->list, &hdev->monitored_devices);
812 	hdev->advmon_pend_notify = true;
813 }
814 
815 /* This function requires the caller holds hdev->lock */
816 static void msft_device_lost(struct hci_dev *hdev, bdaddr_t *bdaddr,
817 			     __u8 addr_type, __u16 mgmt_handle)
818 {
819 	if (!msft_monitor_device_del(hdev, mgmt_handle, bdaddr, addr_type,
820 				     true)) {
821 		bt_dev_err(hdev, "MSFT vendor event %u: dev %pMR not in list",
822 			   MSFT_EV_LE_MONITOR_DEVICE, bdaddr);
823 	}
824 }
825 
826 static void *msft_skb_pull(struct hci_dev *hdev, struct sk_buff *skb,
827 			   u8 ev, size_t len)
828 {
829 	void *data;
830 
831 	data = skb_pull_data(skb, len);
832 	if (!data)
833 		bt_dev_err(hdev, "Malformed MSFT vendor event: 0x%02x", ev);
834 
835 	return data;
836 }
837 
838 static int msft_add_address_filter_sync(struct hci_dev *hdev, void *data)
839 {
840 	struct msft_monitor_addr_filter_data *address_filter = data;
841 	struct msft_rp_le_monitor_advertisement *rp;
842 	struct msft_cp_le_monitor_advertisement *cp;
843 	struct msft_data *msft = hdev->msft_data;
844 	struct sk_buff *skb = NULL;
845 	bool remove = false;
846 	size_t size;
847 
848 	if (!msft) {
849 		bt_dev_err(hdev, "MSFT: msft data is freed");
850 		return -EINVAL;
851 	}
852 
853 	/* The address filter has been removed by hci dev close */
854 	if (!test_bit(HCI_UP, &hdev->flags))
855 		return -ENODEV;
856 
857 	/* We are safe to use the address filter from now on.
858 	 * msft_monitor_device_evt() wouldn't delete this filter because it's
859 	 * not been added by now.
860 	 * And all other functions that requiring hci_req_sync_lock wouldn't
861 	 * touch this filter before this func completes because it's protected
862 	 * by hci_req_sync_lock.
863 	 */
864 
865 	if (address_filter->state == AF_STATE_REMOVING) {
866 		mutex_lock(&msft->filter_lock);
867 		list_del(&address_filter->list);
868 		mutex_unlock(&msft->filter_lock);
869 		kfree(address_filter);
870 		return 0;
871 	}
872 
873 	size = sizeof(*cp) +
874 	       sizeof(address_filter->addr_type) +
875 	       sizeof(address_filter->bdaddr);
876 	cp = kzalloc(size, GFP_KERNEL);
877 	if (!cp) {
878 		bt_dev_err(hdev, "MSFT: Alloc cmd param err");
879 		remove = true;
880 		goto done;
881 	}
882 
883 	cp->sub_opcode           = MSFT_OP_LE_MONITOR_ADVERTISEMENT;
884 	cp->rssi_high		 = address_filter->rssi_high;
885 	cp->rssi_low		 = address_filter->rssi_low;
886 	cp->rssi_low_interval    = address_filter->rssi_low_interval;
887 	cp->rssi_sampling_period = address_filter->rssi_sampling_period;
888 	cp->cond_type            = MSFT_MONITOR_ADVERTISEMENT_TYPE_ADDR;
889 	cp->data[0]              = address_filter->addr_type;
890 	memcpy(&cp->data[1], &address_filter->bdaddr,
891 	       sizeof(address_filter->bdaddr));
892 
893 	skb = __hci_cmd_sync(hdev, hdev->msft_opcode, size, cp,
894 			     HCI_CMD_TIMEOUT);
895 	kfree(cp);
896 
897 	if (IS_ERR(skb)) {
898 		bt_dev_err(hdev, "Failed to enable address %pMR filter",
899 			   &address_filter->bdaddr);
900 		skb = NULL;
901 		remove = true;
902 		goto done;
903 	}
904 
905 	rp = skb_pull_data(skb, sizeof(*rp));
906 	if (!rp || rp->sub_opcode != MSFT_OP_LE_MONITOR_ADVERTISEMENT ||
907 	    rp->status)
908 		remove = true;
909 
910 done:
911 	mutex_lock(&msft->filter_lock);
912 
913 	if (remove) {
914 		bt_dev_warn(hdev, "MSFT: Remove address (%pMR) filter",
915 			    &address_filter->bdaddr);
916 		list_del(&address_filter->list);
917 		kfree(address_filter);
918 	} else {
919 		address_filter->state = AF_STATE_ADDED;
920 		address_filter->msft_handle = rp->handle;
921 		bt_dev_dbg(hdev, "MSFT: Address %pMR filter enabled",
922 			   &address_filter->bdaddr);
923 	}
924 	mutex_unlock(&msft->filter_lock);
925 
926 	kfree_skb(skb);
927 
928 	return 0;
929 }
930 
931 /* This function requires the caller holds msft->filter_lock */
932 static struct msft_monitor_addr_filter_data *msft_add_address_filter
933 		(struct hci_dev *hdev, u8 addr_type, bdaddr_t *bdaddr,
934 		 struct msft_monitor_advertisement_handle_data *handle_data)
935 {
936 	struct msft_monitor_addr_filter_data *address_filter = NULL;
937 	struct msft_data *msft = hdev->msft_data;
938 	int err;
939 
940 	address_filter = kzalloc_obj(*address_filter);
941 	if (!address_filter)
942 		return NULL;
943 
944 	address_filter->state             = AF_STATE_ADDING;
945 	address_filter->msft_handle       = 0xff;
946 	address_filter->pattern_handle    = handle_data->msft_handle;
947 	address_filter->mgmt_handle       = handle_data->mgmt_handle;
948 	address_filter->rssi_high         = handle_data->rssi_high;
949 	address_filter->rssi_low          = handle_data->rssi_low;
950 	address_filter->rssi_low_interval = handle_data->rssi_low_interval;
951 	address_filter->rssi_sampling_period = handle_data->rssi_sampling_period;
952 	address_filter->addr_type            = addr_type;
953 	bacpy(&address_filter->bdaddr, bdaddr);
954 
955 	/* With the above AF_STATE_ADDING, duplicated address filter can be
956 	 * avoided when receiving monitor device event (found/lost) frequently
957 	 * for the same device.
958 	 */
959 	list_add_tail(&address_filter->list, &msft->address_filters);
960 
961 	err = hci_cmd_sync_queue(hdev, msft_add_address_filter_sync,
962 				 address_filter, NULL);
963 	if (err < 0) {
964 		bt_dev_err(hdev, "MSFT: Add address %pMR filter err", bdaddr);
965 		list_del(&address_filter->list);
966 		kfree(address_filter);
967 		return NULL;
968 	}
969 
970 	bt_dev_dbg(hdev, "MSFT: Add device %pMR address filter",
971 		   &address_filter->bdaddr);
972 
973 	return address_filter;
974 }
975 
976 /* This function requires the caller holds hdev->lock */
977 static void msft_monitor_device_evt(struct hci_dev *hdev, struct sk_buff *skb)
978 {
979 	struct msft_monitor_addr_filter_data *n, *address_filter = NULL;
980 	struct msft_ev_le_monitor_device *ev;
981 	struct msft_monitor_advertisement_handle_data *handle_data;
982 	struct msft_data *msft = hdev->msft_data;
983 	u16 mgmt_handle = 0xffff;
984 	u8 addr_type;
985 
986 	ev = msft_skb_pull(hdev, skb, MSFT_EV_LE_MONITOR_DEVICE, sizeof(*ev));
987 	if (!ev)
988 		return;
989 
990 	bt_dev_dbg(hdev,
991 		   "MSFT vendor event 0x%02x: handle 0x%04x state %d addr %pMR",
992 		   MSFT_EV_LE_MONITOR_DEVICE, ev->monitor_handle,
993 		   ev->monitor_state, &ev->bdaddr);
994 
995 	handle_data = msft_find_handle_data(hdev, ev->monitor_handle, false);
996 
997 	if (!hci_test_quirk(hdev, HCI_QUIRK_USE_MSFT_EXT_ADDRESS_FILTER)) {
998 		if (!handle_data)
999 			return;
1000 		mgmt_handle = handle_data->mgmt_handle;
1001 		goto report_state;
1002 	}
1003 
1004 	if (handle_data) {
1005 		/* Don't report any device found/lost event from pattern
1006 		 * monitors. Pattern monitor always has its address filters for
1007 		 * tracking devices.
1008 		 */
1009 
1010 		address_filter = msft_find_address_data(hdev, ev->addr_type,
1011 							&ev->bdaddr,
1012 							handle_data->msft_handle);
1013 		if (address_filter)
1014 			return;
1015 
1016 		if (ev->monitor_state && handle_data->cond_type ==
1017 				MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN)
1018 			msft_add_address_filter(hdev, ev->addr_type,
1019 						&ev->bdaddr, handle_data);
1020 
1021 		return;
1022 	}
1023 
1024 	/* This device event is not from pattern monitor.
1025 	 * Report it if there is a corresponding address_filter for it.
1026 	 */
1027 	list_for_each_entry(n, &msft->address_filters, list) {
1028 		if (n->state == AF_STATE_ADDED &&
1029 		    n->msft_handle == ev->monitor_handle) {
1030 			mgmt_handle = n->mgmt_handle;
1031 			address_filter = n;
1032 			break;
1033 		}
1034 	}
1035 
1036 	if (!address_filter) {
1037 		bt_dev_warn(hdev, "MSFT: Unexpected device event %pMR, %u, %u",
1038 			    &ev->bdaddr, ev->monitor_handle, ev->monitor_state);
1039 		return;
1040 	}
1041 
1042 report_state:
1043 	switch (ev->addr_type) {
1044 	case ADDR_LE_DEV_PUBLIC:
1045 		addr_type = BDADDR_LE_PUBLIC;
1046 		break;
1047 
1048 	case ADDR_LE_DEV_RANDOM:
1049 		addr_type = BDADDR_LE_RANDOM;
1050 		break;
1051 
1052 	default:
1053 		bt_dev_err(hdev,
1054 			   "MSFT vendor event 0x%02x: unknown addr type 0x%02x",
1055 			   MSFT_EV_LE_MONITOR_DEVICE, ev->addr_type);
1056 		return;
1057 	}
1058 
1059 	if (ev->monitor_state) {
1060 		msft_device_found(hdev, &ev->bdaddr, addr_type, mgmt_handle);
1061 	} else {
1062 		if (address_filter && address_filter->state == AF_STATE_ADDED) {
1063 			address_filter->state = AF_STATE_REMOVING;
1064 			hci_cmd_sync_queue(hdev,
1065 					   msft_cancel_address_filter_sync,
1066 					   address_filter,
1067 					   NULL);
1068 		}
1069 		msft_device_lost(hdev, &ev->bdaddr, addr_type, mgmt_handle);
1070 	}
1071 }
1072 
1073 void msft_vendor_evt(struct hci_dev *hdev, void *data, struct sk_buff *skb)
1074 {
1075 	struct msft_data *msft = hdev->msft_data;
1076 	u8 *evt_prefix;
1077 	u8 *evt;
1078 
1079 	if (!msft)
1080 		return;
1081 
1082 	/* When the extension has defined an event prefix, check that it
1083 	 * matches, and otherwise just return.
1084 	 */
1085 	if (msft->evt_prefix_len > 0) {
1086 		evt_prefix = msft_skb_pull(hdev, skb, 0, msft->evt_prefix_len);
1087 		if (!evt_prefix)
1088 			return;
1089 
1090 		if (memcmp(evt_prefix, msft->evt_prefix, msft->evt_prefix_len))
1091 			return;
1092 	}
1093 
1094 	/* Every event starts at least with an event code and the rest of
1095 	 * the data is variable and depends on the event code.
1096 	 */
1097 	if (skb->len < 1)
1098 		return;
1099 
1100 	evt = msft_skb_pull(hdev, skb, 0, sizeof(*evt));
1101 	if (!evt)
1102 		return;
1103 
1104 	hci_dev_lock(hdev);
1105 
1106 	switch (*evt) {
1107 	case MSFT_EV_LE_MONITOR_DEVICE:
1108 		mutex_lock(&msft->filter_lock);
1109 		msft_monitor_device_evt(hdev, skb);
1110 		mutex_unlock(&msft->filter_lock);
1111 		break;
1112 
1113 	default:
1114 		bt_dev_dbg(hdev, "MSFT vendor event 0x%02x", *evt);
1115 		break;
1116 	}
1117 
1118 	hci_dev_unlock(hdev);
1119 }
1120 
1121 __u64 msft_get_features(struct hci_dev *hdev)
1122 {
1123 	struct msft_data *msft = hdev->msft_data;
1124 
1125 	return msft ? msft->features : 0;
1126 }
1127 
1128 static void msft_le_set_advertisement_filter_enable_cb(struct hci_dev *hdev,
1129 						       void *user_data,
1130 						       u8 status)
1131 {
1132 	struct msft_cp_le_set_advertisement_filter_enable *cp = user_data;
1133 	struct msft_data *msft = hdev->msft_data;
1134 
1135 	/* Error 0x0C would be returned if the filter enabled status is
1136 	 * already set to whatever we were trying to set.
1137 	 * Although the default state should be disabled, some controller set
1138 	 * the initial value to enabled. Because there is no way to know the
1139 	 * actual initial value before sending this command, here we also treat
1140 	 * error 0x0C as success.
1141 	 */
1142 	if (status != 0x00 && status != 0x0C)
1143 		return;
1144 
1145 	hci_dev_lock(hdev);
1146 
1147 	msft->filter_enabled = cp->enable;
1148 
1149 	if (status == 0x0C)
1150 		bt_dev_warn(hdev, "MSFT filter_enable is already %s",
1151 			    cp->enable ? "on" : "off");
1152 
1153 	hci_dev_unlock(hdev);
1154 }
1155 
1156 /* This function requires the caller holds hci_req_sync_lock */
1157 int msft_add_monitor_pattern(struct hci_dev *hdev, struct adv_monitor *monitor)
1158 {
1159 	struct msft_data *msft = hdev->msft_data;
1160 
1161 	if (!msft)
1162 		return -EOPNOTSUPP;
1163 
1164 	if (msft->resuming || msft->suspending)
1165 		return -EBUSY;
1166 
1167 	return msft_add_monitor_sync(hdev, monitor);
1168 }
1169 
1170 /* This function requires the caller holds hci_req_sync_lock */
1171 int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor)
1172 {
1173 	struct msft_data *msft = hdev->msft_data;
1174 
1175 	if (!msft)
1176 		return -EOPNOTSUPP;
1177 
1178 	if (msft->resuming || msft->suspending)
1179 		return -EBUSY;
1180 
1181 	return msft_remove_monitor_sync(hdev, monitor);
1182 }
1183 
1184 int msft_set_filter_enable(struct hci_dev *hdev, bool enable)
1185 {
1186 	struct msft_cp_le_set_advertisement_filter_enable cp;
1187 	struct msft_data *msft = hdev->msft_data;
1188 	int err;
1189 
1190 	if (!msft)
1191 		return -EOPNOTSUPP;
1192 
1193 	cp.sub_opcode = MSFT_OP_LE_SET_ADVERTISEMENT_FILTER_ENABLE;
1194 	cp.enable = enable;
1195 	err = __hci_cmd_sync_status(hdev, hdev->msft_opcode, sizeof(cp), &cp,
1196 				    HCI_CMD_TIMEOUT);
1197 
1198 	msft_le_set_advertisement_filter_enable_cb(hdev, &cp, err);
1199 
1200 	return 0;
1201 }
1202 
1203 bool msft_curve_validity(struct hci_dev *hdev)
1204 {
1205 	return hdev->msft_curve_validity;
1206 }
1207