Bluetooth: Add toggle to switch off interleave scan

This patch add a configurable parameter to switch off the interleave
scan feature.

Signed-off-by: Howard Chung <howardchung@google.com>
Reviewed-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci_core.h

@@ -363,6 +363,7 @@ struct hci_dev {
 	__u32		clock;
 	__u16		advmon_allowlist_duration;
 	__u16		advmon_no_filter_duration;
+	__u8		enable_advmon_interleave_scan;
 
 	__u16		devid_source;
 	__u16		devid_vendor;

net/bluetooth/hci_core.c

@@ -3594,6 +3594,7 @@ struct hci_dev *hci_alloc_dev(void)
 
 	hdev->advmon_allowlist_duration = 300;
 	hdev->advmon_no_filter_duration = 500;
+	hdev->enable_advmon_interleave_scan = 0x00;	/* Default to disable */
 
 	hdev->sniff_max_interval = 800;
 	hdev->sniff_min_interval = 80;

net/bluetooth/hci_request.c

@@ -1057,7 +1057,8 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
 				      &own_addr_type))
 		return;
 
-	if (__hci_update_interleaved_scan(hdev))
+	if (hdev->enable_advmon_interleave_scan &&
+	    __hci_update_interleaved_scan(hdev))
 		return;
 
 	bt_dev_dbg(hdev, "interleave state %d", hdev->interleave_scan_state);

net/bluetooth/mgmt_config.c

@@ -17,12 +17,24 @@
 		__le16 value; \
 	} __packed _param_name_
 
+#define HDEV_PARAM_U8(_param_name_) \
+	struct {\
+		struct mgmt_tlv entry; \
+		__u8 value; \
+	} __packed _param_name_
+
 #define TLV_SET_U16(_param_code_, _param_name_) \
 	{ \
 		{ cpu_to_le16(_param_code_), sizeof(__u16) }, \
 		cpu_to_le16(hdev->_param_name_) \
 	}
 
+#define TLV_SET_U8(_param_code_, _param_name_) \
+	{ \
+		{ cpu_to_le16(_param_code_), sizeof(__u8) }, \
+		hdev->_param_name_ \
+	}
+
 #define TLV_SET_U16_JIFFIES_TO_MSECS(_param_code_, _param_name_) \
 	{ \
 		{ cpu_to_le16(_param_code_), sizeof(__u16) }, \
@@ -65,6 +77,7 @@ int read_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 		HDEV_PARAM_U16(def_le_autoconnect_timeout);
 		HDEV_PARAM_U16(advmon_allowlist_duration);
 		HDEV_PARAM_U16(advmon_no_filter_duration);
+		HDEV_PARAM_U8(enable_advmon_interleave_scan);
 	} __packed rp = {
 		TLV_SET_U16(0x0000, def_page_scan_type),
 		TLV_SET_U16(0x0001, def_page_scan_int),
@@ -97,6 +110,7 @@ int read_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 					     def_le_autoconnect_timeout),
 		TLV_SET_U16(0x001d, advmon_allowlist_duration),
 		TLV_SET_U16(0x001e, advmon_no_filter_duration),
+		TLV_SET_U8(0x001f, enable_advmon_interleave_scan),
 	};
 
 	bt_dev_dbg(hdev, "sock %p", sk);
@@ -109,6 +123,7 @@ int read_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 
 #define TO_TLV(x)		((struct mgmt_tlv *)(x))
 #define TLV_GET_LE16(tlv)	le16_to_cpu(*((__le16 *)(TO_TLV(tlv)->value)))
+#define TLV_GET_U8(tlv)		(*((__u8 *)(TO_TLV(tlv)->value)))
 
 int set_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 			  u16 data_len)
@@ -125,6 +140,7 @@ int set_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 	/* First pass to validate the tlv */
 	while (buffer_left >= sizeof(struct mgmt_tlv)) {
 		const u8 len = TO_TLV(buffer)->length;
+		size_t exp_type_len;
 		const u16 exp_len = sizeof(struct mgmt_tlv) +
 				    len;
 		const u16 type = le16_to_cpu(TO_TLV(buffer)->type);
@@ -170,20 +186,26 @@ int set_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 		case 0x001b:
 		case 0x001d:
 		case 0x001e:
-			if (len != sizeof(u16)) {
-				bt_dev_warn(hdev, "invalid length %d, exp %zu for type %d",
-					    len, sizeof(u16), type);
-
-				return mgmt_cmd_status(sk, hdev->id,
-					MGMT_OP_SET_DEF_SYSTEM_CONFIG,
-					MGMT_STATUS_INVALID_PARAMS);
-			}
+			exp_type_len = sizeof(u16);
+			break;
+		case 0x001f:
+			exp_type_len = sizeof(u8);
 			break;
 		default:
+			exp_type_len = 0;
 			bt_dev_warn(hdev, "unsupported parameter %u", type);
 			break;
 		}
 
+		if (exp_type_len && len != exp_type_len) {
+			bt_dev_warn(hdev, "invalid length %d, exp %zu for type %d",
+				    len, exp_type_len, type);
+
+			return mgmt_cmd_status(sk, hdev->id,
+				MGMT_OP_SET_DEF_SYSTEM_CONFIG,
+				MGMT_STATUS_INVALID_PARAMS);
+		}
+
 		buffer_left -= exp_len;
 		buffer += exp_len;
 	}
@@ -289,6 +311,9 @@ int set_def_system_config(struct sock *sk, struct hci_dev *hdev, void *data,
 		case 0x0001e:
 			hdev->advmon_no_filter_duration = TLV_GET_LE16(buffer);
 			break;
+		case 0x0001f:
+			hdev->enable_advmon_interleave_scan = TLV_GET_U8(buffer);
+			break;
 		default:
 			bt_dev_warn(hdev, "unsupported parameter %u", type);
 			break;