Bluetooth: advmon offload MSFT add monitor

Enables advertising monitor offloading to the controller, if MSFT
extension is supported. The kernel won't adjust the monitor parameters
to match what the controller supports - that is the user space's
responsibility.

This patch only manages the addition of monitors. Monitor removal is
going to be handled by another patch.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Manish Mandlik <mmandlik@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Reviewed-by: Yun-Hao Chung <howardchung@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

4 files changed, 342 insertions, 40 deletions

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 9d2c9a1c552f..625298f64a20 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3070,27 +3070,56 @@ void hci_free_adv_monitor(struct adv_monitor *monitor)
 	kfree(monitor);
 }
 
-/* This function requires the caller holds hdev->lock */
-int hci_add_adv_monitor(struct hci_dev *hdev, struct adv_monitor *monitor)
+int hci_add_adv_patterns_monitor_complete(struct hci_dev *hdev, u8 status)
+{
+	return mgmt_add_adv_patterns_monitor_complete(hdev, status);
+}
+
+/* Assigns handle to a monitor, and if offloading is supported and power is on,
+ * also attempts to forward the request to the controller.
+ * Returns true if request is forwarded (result is pending), false otherwise.
+ * This function requires the caller holds hdev->lock.
+ */
+bool hci_add_adv_monitor(struct hci_dev *hdev, struct adv_monitor *monitor,
+			 int *err)
 {
 	int min, max, handle;
 
-	if (!monitor)
-		return -EINVAL;
+	*err = 0;
+
+	if (!monitor) {
+		*err = -EINVAL;
+		return false;
+	}
 
 	min = HCI_MIN_ADV_MONITOR_HANDLE;
 	max = HCI_MIN_ADV_MONITOR_HANDLE + HCI_MAX_ADV_MONITOR_NUM_HANDLES;
 	handle = idr_alloc(&hdev->adv_monitors_idr, monitor, min, max,
 			   GFP_KERNEL);
-	if (handle < 0)
-		return handle;
+	if (handle < 0) {
+		*err = handle;
+		return false;
+	}
 
-	hdev->adv_monitors_cnt++;
 	monitor->handle = handle;
 
-	hci_update_background_scan(hdev);
+	if (!hdev_is_powered(hdev))
+		return false;
 
-	return 0;
+	switch (hci_get_adv_monitor_offload_ext(hdev)) {
+	case HCI_ADV_MONITOR_EXT_NONE:
+		hci_update_background_scan(hdev);
+		bt_dev_dbg(hdev, "%s add monitor status %d", hdev->name, *err);
+		/* Message was not forwarded to controller - not an error */
+		return false;
+	case HCI_ADV_MONITOR_EXT_MSFT:
+		*err = msft_add_monitor_pattern(hdev, monitor);
+		bt_dev_dbg(hdev, "%s add monitor msft status %d", hdev->name,
+			   *err);
+		break;
+	}
+
+	return (*err == 0);
 }
 
 static int free_adv_monitor(int id, void *ptr, void *data)
@@ -3134,6 +3163,14 @@ bool hci_is_adv_monitoring(struct hci_dev *hdev)
 	return !idr_is_empty(&hdev->adv_monitors_idr);
 }
 
+int hci_get_adv_monitor_offload_ext(struct hci_dev *hdev)
+{
+	if (msft_monitor_supported(hdev))
+		return HCI_ADV_MONITOR_EXT_MSFT;
+
+	return HCI_ADV_MONITOR_EXT_NONE;
+}
+
 struct bdaddr_list *hci_bdaddr_list_lookup(struct list_head *bdaddr_list,
 					 bdaddr_t *bdaddr, u8 type)
 {
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 72d37c80e071..fea5e9763b72 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -4185,6 +4185,7 @@ static int read_adv_mon_features(struct sock *sk, struct hci_dev *hdev,
 	int handle, err;
 	size_t rp_size = 0;
 	__u32 supported = 0;
+	__u32 enabled = 0;
 	__u16 num_handles = 0;
 	__u16 handles[HCI_MAX_ADV_MONITOR_NUM_HANDLES];
 
@@ -4192,12 +4193,11 @@ static int read_adv_mon_features(struct sock *sk, struct hci_dev *hdev,
 
 	hci_dev_lock(hdev);
 
-	if (msft_get_features(hdev) & MSFT_FEATURE_MASK_LE_ADV_MONITOR)
+	if (msft_monitor_supported(hdev))
 		supported |= MGMT_ADV_MONITOR_FEATURE_MASK_OR_PATTERNS;
 
-	idr_for_each_entry(&hdev->adv_monitors_idr, monitor, handle) {
+	idr_for_each_entry(&hdev->adv_monitors_idr, monitor, handle)
 		handles[num_handles++] = monitor->handle;
-	}
 
 	hci_dev_unlock(hdev);
 
@@ -4206,11 +4206,11 @@ static int read_adv_mon_features(struct sock *sk, struct hci_dev *hdev,
 	if (!rp)
 		return -ENOMEM;
 
-	/* Once controller-based monitoring is in place, the enabled_features
-	 * should reflect the use.
-	 */
+	/* All supported features are currently enabled */
+	enabled = supported;
+
 	rp->supported_features = cpu_to_le32(supported);
-	rp->enabled_features = 0;
+	rp->enabled_features = cpu_to_le32(enabled);
 	rp->max_num_handles = cpu_to_le16(HCI_MAX_ADV_MONITOR_NUM_HANDLES);
 	rp->max_num_patterns = HCI_MAX_ADV_MONITOR_NUM_PATTERNS;
 	rp->num_handles = cpu_to_le16(num_handles);
@@ -4226,44 +4226,105 @@ static int read_adv_mon_features(struct sock *sk, struct hci_dev *hdev,
 	return err;
 }
 
+int mgmt_add_adv_patterns_monitor_complete(struct hci_dev *hdev, u8 status)
+{
+	struct mgmt_rp_add_adv_patterns_monitor rp;
+	struct mgmt_pending_cmd *cmd;
+	struct adv_monitor *monitor;
+	int err = 0;
+
+	hci_dev_lock(hdev);
+
+	cmd = pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI, hdev);
+	if (!cmd) {
+		cmd = pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR, hdev);
+		if (!cmd)
+			goto done;
+	}
+
+	monitor = cmd->user_data;
+	rp.monitor_handle = cpu_to_le16(monitor->handle);
+
+	if (!status) {
+		mgmt_adv_monitor_added(cmd->sk, hdev, monitor->handle);
+		hdev->adv_monitors_cnt++;
+		if (monitor->state == ADV_MONITOR_STATE_NOT_REGISTERED)
+			monitor->state = ADV_MONITOR_STATE_REGISTERED;
+		hci_update_background_scan(hdev);
+	}
+
+	err = mgmt_cmd_complete(cmd->sk, cmd->index, cmd->opcode,
+				mgmt_status(status), &rp, sizeof(rp));
+	mgmt_pending_remove(cmd);
+
+done:
+	hci_dev_unlock(hdev);
+	bt_dev_dbg(hdev, "add monitor %d complete, status %d",
+		   rp.monitor_handle, status);
+
+	return err;
+}
+
 static int __add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev,
-				      struct adv_monitor *m, u8 status, u16 op)
+				      struct adv_monitor *m, u8 status,
+				      void *data, u16 len, u16 op)
 {
 	struct mgmt_rp_add_adv_patterns_monitor rp;
-	unsigned int prev_adv_monitors_cnt;
+	struct mgmt_pending_cmd *cmd;
 	int err;
+	bool pending;
+
+	hci_dev_lock(hdev);
 
 	if (status)
-		goto failed;
+		goto unlock;
 
-	hci_dev_lock(hdev);
+	if (pending_find(MGMT_OP_SET_LE, hdev) ||
+	    pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR, hdev) ||
+	    pending_find(MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI, hdev) ||
+	    pending_find(MGMT_OP_REMOVE_ADV_MONITOR, hdev)) {
+		status = MGMT_STATUS_BUSY;
+		goto unlock;
+	}
 
-	prev_adv_monitors_cnt = hdev->adv_monitors_cnt;
+	cmd = mgmt_pending_add(sk, op, hdev, data, len);
+	if (!cmd) {
+		status = MGMT_STATUS_NO_RESOURCES;
+		goto unlock;
+	}
 
-	err = hci_add_adv_monitor(hdev, m);
+	pending = hci_add_adv_monitor(hdev, m, &err);
 	if (err) {
-		if (err == -ENOSPC)
+		if (err == -ENOSPC || err == -ENOMEM)
 			status = MGMT_STATUS_NO_RESOURCES;
+		else if (err == -EINVAL)
+			status = MGMT_STATUS_INVALID_PARAMS;
 		else
 			status = MGMT_STATUS_FAILED;
 
+		mgmt_pending_remove(cmd);
 		goto unlock;
 	}
 
-	if (hdev->adv_monitors_cnt > prev_adv_monitors_cnt)
+	if (!pending) {
+		mgmt_pending_remove(cmd);
+		rp.monitor_handle = cpu_to_le16(m->handle);
 		mgmt_adv_monitor_added(sk, hdev, m->handle);
+		m->state = ADV_MONITOR_STATE_REGISTERED;
+		hdev->adv_monitors_cnt++;
 
-	hci_dev_unlock(hdev);
+		hci_dev_unlock(hdev);
+		return mgmt_cmd_complete(sk, hdev->id, op, MGMT_STATUS_SUCCESS,
+					 &rp, sizeof(rp));
+	}
 
-	rp.monitor_handle = cpu_to_le16(m->handle);
+	hci_dev_unlock(hdev);
 
-	return mgmt_cmd_complete(sk, hdev->id, op,
-				 MGMT_STATUS_SUCCESS, &rp, sizeof(rp));
+	cmd->user_data = m;
+	return 0;
 
 unlock:
 	hci_dev_unlock(hdev);
-
-failed:
 	hci_free_adv_monitor(m);
 	return mgmt_cmd_status(sk, hdev->id, op, status);
 }
@@ -4298,13 +4359,9 @@ static u8 parse_adv_monitor_pattern(struct adv_monitor *m, u8 pattern_count,
 {
 	u8 offset = 0, length = 0;
 	struct adv_pattern *p = NULL;
-	unsigned int mp_cnt = 0;
 	int i;
 
 	for (i = 0; i < pattern_count; i++) {
-		if (++mp_cnt > HCI_MAX_ADV_MONITOR_NUM_PATTERNS)
-			return MGMT_STATUS_INVALID_PARAMS;
-
 		offset = patterns[i].offset;
 		length = patterns[i].length;
 		if (offset >= HCI_MAX_AD_LENGTH ||
@@ -4325,9 +4382,6 @@ static u8 parse_adv_monitor_pattern(struct adv_monitor *m, u8 pattern_count,
 		list_add(&p->list, &m->patterns);
 	}
 
-	if (mp_cnt != pattern_count)
-		return MGMT_STATUS_INVALID_PARAMS;
-
 	return MGMT_STATUS_SUCCESS;
 }
 
@@ -4364,7 +4418,7 @@ static int add_adv_patterns_monitor(struct sock *sk, struct hci_dev *hdev,
 	status = parse_adv_monitor_pattern(m, cp->pattern_count, cp->patterns);
 
 done:
-	return __add_adv_patterns_monitor(sk, hdev, m, status,
+	return __add_adv_patterns_monitor(sk, hdev, m, status, data, len,
 					  MGMT_OP_ADD_ADV_PATTERNS_MONITOR);
 }
 
@@ -4401,7 +4455,7 @@ static int add_adv_patterns_monitor_rssi(struct sock *sk, struct hci_dev *hdev,
 	status = parse_adv_monitor_pattern(m, cp->pattern_count, cp->patterns);
 
 done:
-	return __add_adv_patterns_monitor(sk, hdev, m, status,
+	return __add_adv_patterns_monitor(sk, hdev, m, status, data, len,
 					 MGMT_OP_ADD_ADV_PATTERNS_MONITOR_RSSI);
 }
 
diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
index 4b39534a14a1..e4b8fe71b9c3 100644
--- a/net/bluetooth/msft.c
+++ b/net/bluetooth/msft.c
@@ -5,9 +5,16 @@
 
 #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;
@@ -21,12 +28,55 @@ struct msft_rp_read_supported_features {
 	__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;
+
+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;
 };
 
+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)
 {
@@ -90,12 +140,14 @@ void msft_do_open(struct hci_dev *hdev)
 		return;
 	}
 
+	INIT_LIST_HEAD(&msft->handle_map);
 	hdev->msft_data = msft;
 }
 
 void msft_do_close(struct hci_dev *hdev)
 {
 	struct msft_data *msft = hdev->msft_data;
+	struct msft_monitor_advertisement_handle_data *handle_data, *tmp;
 
 	if (!msft)
 		return;
@@ -104,6 +156,11 @@ void msft_do_close(struct hci_dev *hdev)
 
 	hdev->msft_data = NULL;
 
+	list_for_each_entry_safe(handle_data, tmp, &msft->handle_map, list) {
+		list_del(&handle_data->list);
+		kfree(handle_data);
+	}
+
 	kfree(msft->evt_prefix);
 	kfree(msft);
 }
@@ -145,5 +202,147 @@ __u64 msft_get_features(struct hci_dev *hdev)
 {
 	struct msft_data *msft = hdev->msft_data;
 
-	return  msft ? msft->features : 0;
+	return msft ? msft->features : 0;
+}
+
+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) {
+		idr_remove(&hdev->adv_monitors_idr, monitor->handle);
+		hci_free_adv_monitor(monitor);
+	}
+
+	hci_dev_unlock(hdev);
+
+	hci_add_adv_patterns_monitor_complete(hdev, status);
+}
+
+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 */
+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)
+		return -EOPNOTSUPP;
+
+	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;
 }
diff --git a/net/bluetooth/msft.h b/net/bluetooth/msft.h
index e9c478e890b8..0ac9b15322b1 100644
--- a/net/bluetooth/msft.h
+++ b/net/bluetooth/msft.h
@@ -12,16 +12,28 @@
 
 #if IS_ENABLED(CONFIG_BT_MSFTEXT)
 
+bool msft_monitor_supported(struct hci_dev *hdev);
 void msft_do_open(struct hci_dev *hdev);
 void msft_do_close(struct hci_dev *hdev);
 void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb);
 __u64 msft_get_features(struct hci_dev *hdev);
+int msft_add_monitor_pattern(struct hci_dev *hdev, struct adv_monitor *monitor);
 
 #else
 
+static inline bool msft_monitor_supported(struct hci_dev *hdev)
+{
+	return false;
+}
+
 static inline void msft_do_open(struct hci_dev *hdev) {}
 static inline void msft_do_close(struct hci_dev *hdev) {}
 static inline void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb) {}
 static inline __u64 msft_get_features(struct hci_dev *hdev) { return 0; }
+static inline int msft_add_monitor_pattern(struct hci_dev *hdev,
+					   struct adv_monitor *monitor)
+{
+	return -EOPNOTSUPP;
+}
 
 #endif