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>

1 files changed, 200 insertions, 1 deletions

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;
 }