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Commit 48f86b7f authored by Jakub Pawlowski's avatar Jakub Pawlowski Committed by Johan Hedberg
Browse files

Bluetooth: Move Service Discovery logic before refactoring 



This patch moves whole packet filering logic of service discovery
into new function is_filter_match. It's done because logic inside
mgmt_device_found is very complicated and needs some
simplification.

Also having whole logic in one place will allow to simplify it in
the future.

Signed-off-by: default avatarJakub Pawlowski <jpawlowski@google.com>
Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
parent 263be332

net/bluetooth/mgmt.c

+79 −62
Original line number Diff line number Diff line
@@ -7280,32 +7280,16 @@ static void restart_le_scan(struct hci_dev *hdev) 
			   DISCOV_LE_RESTART_DELAY);

}



void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,

		       u8 addr_type, u8 *dev_class, s8 rssi, u32 flags,

		       u8 *eir, u16 eir_len, u8 *scan_rsp, u8 scan_rsp_len)

static bool is_filter_match(struct hci_dev *hdev, s8 rssi, u8 *eir,

			    u16 eir_len, u8 *scan_rsp, u8 scan_rsp_len)

{

	char buf[512];

	struct mgmt_ev_device_found *ev = (void *) buf;

	size_t ev_size;

	bool match;



	/* Don't send events for a non-kernel initiated discovery. With

	 * LE one exception is if we have pend_le_reports > 0 in which

	 * case we're doing passive scanning and want these events.

	 */

	if (!hci_discovery_active(hdev)) {

		if (link_type == ACL_LINK)

			return;

		if (link_type == LE_LINK && list_empty(&hdev->pend_le_reports))

			return;

	}



	/* When using service discovery with a RSSI threshold, then check

	 * if such a RSSI threshold is specified. If a RSSI threshold has

	 * been specified, and HCI_QUIRK_STRICT_DUPLICATE_FILTER is not set,

	 * then all results with a RSSI smaller than the RSSI threshold will be

	 * dropped. If the quirk is set, let it through for further processing,

	 * as we might need to restart the scan.

	/* If a RSSI threshold has been specified, and

	 * HCI_QUIRK_STRICT_DUPLICATE_FILTER is not set, then all results with

	 * a RSSI smaller than the RSSI threshold will be dropped. If the quirk

	 * is set, let it through for further processing, as we might need to

	 * restart the scan.

	 *

	 * For BR/EDR devices (pre 1.2) providing no RSSI during inquiry,

	 * the results are also dropped.
@@ -7314,32 +7298,8 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, 
	    (rssi == HCI_RSSI_INVALID ||

	    (rssi < hdev->discovery.rssi &&

	     !test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks))))

		return;



	/* Make sure that the buffer is big enough. The 5 extra bytes

	 * are for the potential CoD field.

	 */

	if (sizeof(*ev) + eir_len + scan_rsp_len + 5 > sizeof(buf))

		return;



	memset(buf, 0, sizeof(buf));



	/* In case of device discovery with BR/EDR devices (pre 1.2), the

	 * RSSI value was reported as 0 when not available. This behavior

	 * is kept when using device discovery. This is required for full

	 * backwards compatibility with the API.

	 *

	 * However when using service discovery, the value 127 will be

	 * returned when the RSSI is not available.

	 */

	if (rssi == HCI_RSSI_INVALID && !hdev->discovery.report_invalid_rssi &&

	    link_type == ACL_LINK)

		rssi = 0;

		return  false;



	bacpy(&ev->addr.bdaddr, bdaddr);

	ev->addr.type = link_to_bdaddr(link_type, addr_type);

	ev->rssi = rssi;

	ev->flags = cpu_to_le32(flags);



	if (eir_len > 0) {

		/* When using service discovery and a list of UUID is
@@ -7364,25 +7324,18 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, 
		}



		if (!match && !scan_rsp_len)

			return;



		/* Copy EIR or advertising data into event */

		memcpy(ev->eir, eir, eir_len);

			return  false;

	} else {

		/* When using service discovery and a list of UUID is

		 * provided, results with empty EIR or advertising data

		 * should be dropped since they do not match any UUID.

		 */

		if (hdev->discovery.uuid_count > 0 && !scan_rsp_len)

			return;

			return  false;



		match = false;

	}



	if (dev_class && !eir_has_data_type(ev->eir, eir_len, EIR_CLASS_OF_DEV))

		eir_len = eir_append_data(ev->eir, eir_len, EIR_CLASS_OF_DEV,

					  dev_class, 3);



	if (scan_rsp_len > 0) {

		/* When using service discovery and a list of UUID is

		 * provided, results with no matching UUID should be
@@ -7393,7 +7346,7 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, 
			if (!match && !eir_has_uuids(scan_rsp, scan_rsp_len,

						     hdev->discovery.uuid_count,

						     hdev->discovery.uuids))

				return;

				return  false;



			/* If duplicate filtering does not report RSSI changes,

			 * then restart scanning to ensure updated result with
@@ -7403,16 +7356,13 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, 
				     &hdev->quirks))

				restart_le_scan(hdev);

		}



		/* Append scan response data to event */

		memcpy(ev->eir + eir_len, scan_rsp, scan_rsp_len);

	} else {

		/* When using service discovery and a list of UUID is

		 * provided, results with empty scan response and no

		 * previous matched advertising data should be dropped.

		 */

		if (hdev->discovery.uuid_count > 0 && !match)

			return;

			return  false;

	}



	/* Validate the reported RSSI value against the RSSI threshold once more
@@ -7421,8 +7371,75 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, 
	 */

	if (hdev->discovery.rssi != HCI_RSSI_INVALID &&

	    rssi < hdev->discovery.rssi)

		return  false;



	return true;

}



void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,

		       u8 addr_type, u8 *dev_class, s8 rssi, u32 flags,

		       u8 *eir, u16 eir_len, u8 *scan_rsp, u8 scan_rsp_len)

{

	char buf[512];

	struct mgmt_ev_device_found *ev = (void *)buf;

	size_t ev_size;



	/* Don't send events for a non-kernel initiated discovery. With

	 * LE one exception is if we have pend_le_reports > 0 in which

	 * case we're doing passive scanning and want these events.

	 */

	if (!hci_discovery_active(hdev)) {

		if (link_type == ACL_LINK)

			return;

		if (link_type == LE_LINK && list_empty(&hdev->pend_le_reports))

			return;

	}



	if (hdev->discovery.rssi != HCI_RSSI_INVALID ||

	    hdev->discovery.uuid_count > 0) {

		/* We are using service discovery */

		if (!is_filter_match(hdev, rssi, eir, eir_len, scan_rsp,

				     scan_rsp_len))

			return;

	}



	/* Make sure that the buffer is big enough. The 5 extra bytes

	 * are for the potential CoD field.

	 */

	if (sizeof(*ev) + eir_len + scan_rsp_len + 5 > sizeof(buf))

		return;



	memset(buf, 0, sizeof(buf));



	/* In case of device discovery with BR/EDR devices (pre 1.2), the

	 * RSSI value was reported as 0 when not available. This behavior

	 * is kept when using device discovery. This is required for full

	 * backwards compatibility with the API.

	 *

	 * However when using service discovery, the value 127 will be

	 * returned when the RSSI is not available.

	 */

	if (rssi == HCI_RSSI_INVALID && !hdev->discovery.report_invalid_rssi &&

	    link_type == ACL_LINK)

		rssi = 0;



	bacpy(&ev->addr.bdaddr, bdaddr);

	ev->addr.type = link_to_bdaddr(link_type, addr_type);

	ev->rssi = rssi;

	ev->flags = cpu_to_le32(flags);



	if (eir_len > 0)

		/* Copy EIR or advertising data into event */

		memcpy(ev->eir, eir, eir_len);



	if (dev_class && !eir_has_data_type(ev->eir, eir_len, EIR_CLASS_OF_DEV))

		eir_len = eir_append_data(ev->eir, eir_len, EIR_CLASS_OF_DEV,

					  dev_class, 3);



	if (scan_rsp_len > 0)

		/* Append scan response data to event */

		memcpy(ev->eir + eir_len, scan_rsp, scan_rsp_len);



	ev->eir_len = cpu_to_le16(eir_len + scan_rsp_len);

	ev_size = sizeof(*ev) + eir_len + scan_rsp_len;