Bluetooth: Configure controller address resolution if available

When the LL Privacy support is available, then as part of enabling or
disabling passive background scanning, it is required to set up the
controller based address resolution as well.

Since only passive background scanning is utilizing the whitelist, the
address resolution is now bound to the whitelist and passive background
scanning. All other resolution can be easily done by the host stack.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sathish Narsimman <sathish.narasimman@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -1359,6 +1359,9 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
 #define scan_coded(dev) (((dev)->le_tx_def_phys & HCI_LE_SET_PHY_CODED) || \
 			 ((dev)->le_rx_def_phys & HCI_LE_SET_PHY_CODED))
 
+/* Use LL Privacy based address resolution if supported */
+#define use_ll_privacy(dev) ((dev)->le_features[0] & HCI_LE_LL_PRIVACY)
+
 /* Use ext scanning if set ext scan param and ext scan enable is supported */
 #define use_ext_scan(dev) (((dev)->commands[37] & 0x20) && \
 			   ((dev)->commands[37] & 0x40))

net/bluetooth/hci_request.c

@@ -675,6 +675,12 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
 		cp.enable = LE_SCAN_DISABLE;
 		hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
 	}
+
+	if (use_ll_privacy(hdev) &&
+	    hci_dev_test_flag(hdev, HCI_LL_RPA_RESOLUTION)) {
+		__u8 enable = 0x00;
+		hci_req_add(req, HCI_OP_LE_SET_ADDR_RESOLV_ENABLE, 1, &enable);
+	}
 }
 
 static void del_from_white_list(struct hci_request *req, bdaddr_t *bdaddr,
@@ -816,7 +822,8 @@ static bool scan_use_rpa(struct hci_dev *hdev)
 }
 
 static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
-			       u16 window, u8 own_addr_type, u8 filter_policy)
+			       u16 window, u8 own_addr_type, u8 filter_policy,
+			       bool addr_resolv)
 {
 	struct hci_dev *hdev = req->hdev;
 
@@ -825,6 +832,11 @@ static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
 		return;
 	}
 
+	if (use_ll_privacy(hdev) && addr_resolv) {
+		u8 enable = 0x01;
+		hci_req_add(req, HCI_OP_LE_SET_ADDR_RESOLV_ENABLE, 1, &enable);
+	}
+
 	/* Use ext scanning if set ext scan param and ext scan enable is
 	 * supported
 	 */
@@ -898,12 +910,18 @@ static void hci_req_start_scan(struct hci_request *req, u8 type, u16 interval,
 	}
 }
 
+/* Ensure to call hci_req_add_le_scan_disable() first to disable the
+ * controller based address resolution to be able to reconfigure
+ * resolving list.
+ */
 void hci_req_add_le_passive_scan(struct hci_request *req)
 {
 	struct hci_dev *hdev = req->hdev;
 	u8 own_addr_type;
 	u8 filter_policy;
 	u16 window, interval;
+	/* Background scanning should run with address resolution */
+	bool addr_resolv = true;
 
 	if (hdev->scanning_paused) {
 		bt_dev_dbg(hdev, "Scanning is paused for suspend");
@@ -949,7 +967,7 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
 
 	bt_dev_dbg(hdev, "LE passive scan with whitelist = %d", filter_policy);
 	hci_req_start_scan(req, LE_SCAN_PASSIVE, interval, window,
-			   own_addr_type, filter_policy);
+			   own_addr_type, filter_policy, addr_resolv);
 }
 
 static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
@@ -2789,6 +2807,8 @@ static int active_scan(struct hci_request *req, unsigned long opt)
 	u8 own_addr_type;
 	/* White list is not used for discovery */
 	u8 filter_policy = 0x00;
+	/* Discovery doesn't require controller address resolution */
+	bool addr_resolv = false;
 	int err;
 
 	BT_DBG("%s", hdev->name);
@@ -2811,7 +2831,7 @@ static int active_scan(struct hci_request *req, unsigned long opt)
 
 	hci_req_start_scan(req, LE_SCAN_ACTIVE, interval,
 			   hdev->le_scan_window_discovery, own_addr_type,
-			   filter_policy);
+			   filter_policy, addr_resolv);
 	return 0;
 }