[BlueZ PATCH v6 3/6] adv_monitor: Receive the Device Found/Lost events

[Manish Mandlik <mmandlik@google.com>]

This patch registers callback functions to receive the Advertisement
Monitor Device Found and Device Lost events. It also disables software
based filtering whenever controller offloading support is available.

Test performed:
- Verified by logs that the MSFT Monitor Device is received from the
  controller and the bluetoothd is notified whenever the controller
  starts/stops monitoring a device.

Reviewed-by: Miao-chen Chou <mcchou@google.com>
---

Changes in v6:
- Removed unused variable 'handle'.

Changes in v5:
- Update the Adv Monitor Device Found event to include fields from the
  existing Device Found event and update the device object.
- Disable the software based filtering whenever controller offloading is
  available.

Changes in v4:
- Add Advertisement Monitor Device Found event.

Changes in v3:
- Fix indentation of the adv_monitor_device_lost_callback() name and
  it's arguments.

Changes in v2:
- Update function name adv_monitor_tracking_callback() to
  adv_monitor_device_lost_callback() as it will receive only Device Lost
  event.

 src/adapter.c     | 47 ++++++++++++++-----------
 src/adapter.h     |  8 +++++
 src/adv_monitor.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
 src/adv_monitor.h |  2 ++
 4 files changed, 127 insertions(+), 20 deletions(-)

diff --git a/src/adapter.c b/src/adapter.c
index d0d38621b..42463a3c1 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -6984,12 +6984,13 @@ static bool device_is_discoverable(struct btd_adapter *adapter,
 	return discoverable;
 }
 
-static void update_found_devices(struct btd_adapter *adapter,
+void btd_adapter_update_found_device(struct btd_adapter *adapter,
 					const bdaddr_t *bdaddr,
 					uint8_t bdaddr_type, int8_t rssi,
 					bool confirm, bool legacy,
 					bool not_connectable,
-					const uint8_t *data, uint8_t data_len)
+					const uint8_t *data, uint8_t data_len,
+					bool monitoring)
 {
 	struct btd_device *dev;
 	struct bt_ad *ad = NULL;
@@ -6999,20 +7000,24 @@ static void update_found_devices(struct btd_adapter *adapter,
 	bool duplicate = false;
 	struct queue *matched_monitors = NULL;
 
-	if (bdaddr_type != BDADDR_BREDR)
-		ad = bt_ad_new_with_data(data_len, data);
+	if (!btd_adv_monitor_offload_supported(adapter->adv_monitor_manager)) {
+		if (bdaddr_type != BDADDR_BREDR)
+			ad = bt_ad_new_with_data(data_len, data);
 
-	/* During the background scanning, update the device only when the data
-	 * match at least one Adv monitor
-	 */
-	if (ad) {
-		matched_monitors = btd_adv_monitor_content_filter(
-					adapter->adv_monitor_manager, ad);
-		bt_ad_unref(ad);
-		ad = NULL;
+		/* During the background scanning, update the device only when
+		 * the data match at least one Adv monitor
+		 */
+		if (ad) {
+			matched_monitors = btd_adv_monitor_content_filter(
+						adapter->adv_monitor_manager,
+						ad);
+			bt_ad_unref(ad);
+			ad = NULL;
+			monitoring = matched_monitors ? true : false;
+		}
 	}
 
-	if (!adapter->discovering && !matched_monitors)
+	if (!adapter->discovering && !monitoring)
 		return;
 
 	memset(&eir_data, 0, sizeof(eir_data));
@@ -7025,7 +7030,7 @@ static void update_found_devices(struct btd_adapter *adapter,
 
 	dev = btd_adapter_find_device(adapter, bdaddr, bdaddr_type);
 	if (!dev) {
-		if (!discoverable && !matched_monitors) {
+		if (!discoverable && !monitoring) {
 			eir_data_free(&eir_data);
 			return;
 		}
@@ -7064,7 +7069,7 @@ static void update_found_devices(struct btd_adapter *adapter,
 	 */
 	if (!btd_device_is_connected(dev) &&
 		(device_is_temporary(dev) && !adapter->discovery_list) &&
-		!matched_monitors) {
+		!monitoring) {
 		eir_data_free(&eir_data);
 		return;
 	}
@@ -7072,7 +7077,7 @@ static void update_found_devices(struct btd_adapter *adapter,
 	/* If there is no matched Adv monitors, don't continue if not
 	 * discoverable or if active discovery filter don't match.
 	 */
-	if (!matched_monitors && (!discoverable ||
+	if (!monitoring && (!discoverable ||
 		(adapter->filtered_discovery && !is_filter_match(
 				adapter->discovery_list, &eir_data, rssi)))) {
 		eir_data_free(&eir_data);
@@ -7202,6 +7207,7 @@ static void device_found_callback(uint16_t index, uint16_t length,
 	bool confirm_name;
 	bool legacy;
 	char addr[18];
+	bool not_connectable;
 
 	if (length < sizeof(*ev)) {
 		btd_error(adapter->dev_id,
@@ -7230,11 +7236,12 @@ static void device_found_callback(uint16_t index, uint16_t length,
 
 	confirm_name = (flags & MGMT_DEV_FOUND_CONFIRM_NAME);
 	legacy = (flags & MGMT_DEV_FOUND_LEGACY_PAIRING);
+	not_connectable = (flags & MGMT_DEV_FOUND_NOT_CONNECTABLE);
 
-	update_found_devices(adapter, &ev->addr.bdaddr, ev->addr.type,
-					ev->rssi, confirm_name, legacy,
-					flags & MGMT_DEV_FOUND_NOT_CONNECTABLE,
-					eir, eir_len);
+	btd_adapter_update_found_device(adapter, &ev->addr.bdaddr,
+					ev->addr.type, ev->rssi, confirm_name,
+					legacy, not_connectable, eir, eir_len,
+					false);
 }
 
 struct agent *adapter_get_agent(struct btd_adapter *adapter)
diff --git a/src/adapter.h b/src/adapter.h
index db3c17f23..cd0d037af 100644
--- a/src/adapter.h
+++ b/src/adapter.h
@@ -87,6 +87,14 @@ struct btd_device *btd_adapter_find_device(struct btd_adapter *adapter,
 struct btd_device *btd_adapter_find_device_by_path(struct btd_adapter *adapter,
 						   const char *path);
 
+void btd_adapter_update_found_device(struct btd_adapter *adapter,
+					const bdaddr_t *bdaddr,
+					uint8_t bdaddr_type, int8_t rssi,
+					bool confirm, bool legacy,
+					bool not_connectable,
+					const uint8_t *data, uint8_t data_len,
+					bool monitored);
+
 const char *adapter_get_path(struct btd_adapter *adapter);
 const bdaddr_t *btd_adapter_get_address(struct btd_adapter *adapter);
 uint8_t btd_adapter_get_address_type(struct btd_adapter *adapter);
diff --git a/src/adv_monitor.c b/src/adv_monitor.c
index a3b33188b..ca8aa976c 100644
--- a/src/adv_monitor.c
+++ b/src/adv_monitor.c
@@ -1531,6 +1531,77 @@ static void adv_monitor_removed_callback(uint16_t index, uint16_t length,
 		ev->monitor_handle);
 }
 
+/* Processes Adv Monitor Device Found event from kernel */
+static void adv_monitor_device_found_callback(uint16_t index, uint16_t length,
+						const void *param,
+						void *user_data)
+{
+	const struct mgmt_ev_adv_monitor_device_found *ev = param;
+	struct btd_adv_monitor_manager *manager = user_data;
+	const uint16_t adapter_id = manager->adapter_id;
+	struct btd_adapter *adapter = manager->adapter;
+	const uint8_t *ad_data = NULL;
+	uint16_t ad_data_len;
+	uint32_t flags;
+	bool confirm_name;
+	bool legacy;
+	char addr[18];
+	bool not_connectable;
+
+	if (length < sizeof(*ev)) {
+		btd_error(adapter_id,
+				"Too short Adv Monitor Device Found event");
+		return;
+	}
+
+	ad_data_len = btohs(ev->ad_data_len);
+	if (length != sizeof(*ev) + ad_data_len) {
+		btd_error(adapter_id,
+				"Wrong size of Adv Monitor Device Found event");
+		return;
+	}
+
+	if (ad_data_len > 0)
+		ad_data = ev->ad_data;
+
+	flags = btohl(ev->flags);
+
+	ba2str(&ev->addr.bdaddr, addr);
+	DBG("hci%u addr %s, rssi %d flags 0x%04x ad_data_len %u",
+			index, addr, ev->rssi, flags, ad_data_len);
+
+	confirm_name = (flags & MGMT_DEV_FOUND_CONFIRM_NAME);
+	legacy = (flags & MGMT_DEV_FOUND_LEGACY_PAIRING);
+	not_connectable = (flags & MGMT_DEV_FOUND_NOT_CONNECTABLE);
+
+	btd_adapter_update_found_device(adapter, &ev->addr.bdaddr,
+					ev->addr.type, ev->rssi, confirm_name,
+					legacy, not_connectable, ad_data,
+					ad_data_len, true);
+}
+
+/* Processes Adv Monitor Device Lost event from kernel */
+static void adv_monitor_device_lost_callback(uint16_t index, uint16_t length,
+						const void *param,
+						void *user_data)
+{
+	struct btd_adv_monitor_manager *manager = user_data;
+	const struct mgmt_ev_adv_monitor_device_lost *ev = param;
+	uint16_t handle = le16_to_cpu(ev->monitor_handle);
+	const uint16_t adapter_id = manager->adapter_id;
+	char addr[18];
+
+	if (length < sizeof(*ev)) {
+		btd_error(adapter_id,
+				"Wrong size of Adv Monitor Device Lost event");
+		return;
+	}
+
+	ba2str(&ev->addr.bdaddr, addr);
+	DBG("Adv Monitor with handle 0x%04x stopped tracking the device %s",
+		handle, addr);
+}
+
 /* Allocates a manager object */
 static struct btd_adv_monitor_manager *manager_new(
 						struct btd_adapter *adapter,
@@ -1555,6 +1626,14 @@ static struct btd_adv_monitor_manager *manager_new(
 			manager->adapter_id, adv_monitor_removed_callback,
 			manager, NULL);
 
+	mgmt_register(manager->mgmt, MGMT_EV_ADV_MONITOR_DEVICE_FOUND,
+			manager->adapter_id, adv_monitor_device_found_callback,
+			manager, NULL);
+
+	mgmt_register(manager->mgmt, MGMT_EV_ADV_MONITOR_DEVICE_LOST,
+			manager->adapter_id, adv_monitor_device_lost_callback,
+			manager, NULL);
+
 	return manager;
 }
 
@@ -1666,6 +1745,17 @@ void btd_adv_monitor_manager_destroy(struct btd_adv_monitor_manager *manager)
 	manager_destroy(manager);
 }
 
+bool btd_adv_monitor_offload_supported(struct btd_adv_monitor_manager *manager)
+{
+	if (!manager) {
+		error("Manager is NULL, get offload support failed");
+		return false;
+	}
+
+	return !!(manager->enabled_features &
+				MGMT_ADV_MONITOR_FEATURE_MASK_OR_PATTERNS);
+}
+
 /* Processes the content matching based pattern(s) of a monitor */
 static void adv_match_per_monitor(void *data, void *user_data)
 {
diff --git a/src/adv_monitor.h b/src/adv_monitor.h
index d9cb9ccbb..bed6572d0 100644
--- a/src/adv_monitor.h
+++ b/src/adv_monitor.h
@@ -27,6 +27,8 @@ struct btd_adv_monitor_manager *btd_adv_monitor_manager_create(
 						struct mgmt *mgmt);
 void btd_adv_monitor_manager_destroy(struct btd_adv_monitor_manager *manager);
 
+bool btd_adv_monitor_offload_supported(struct btd_adv_monitor_manager *manager);
+
 struct queue *btd_adv_monitor_content_filter(
 				struct btd_adv_monitor_manager *manager,
 				struct bt_ad *ad);
-- 
2.34.0.rc2.393.gf8c9666880-goog