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: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 1e4635a..a41a5ef 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7280,14 +7280,109 @@
DISCOV_LE_RESTART_DELAY);
}
+static bool is_filter_match(struct hci_dev *hdev, s8 rssi, u8 *eir,
+ u16 eir_len, u8 *scan_rsp, u8 scan_rsp_len)
+{
+ bool match;
+
+ /* 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.
+ */
+ if (hdev->discovery.rssi != HCI_RSSI_INVALID &&
+ (rssi == HCI_RSSI_INVALID ||
+ (rssi < hdev->discovery.rssi &&
+ !test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks))))
+ return false;
+
+
+ if (eir_len > 0) {
+ /* When using service discovery and a list of UUID is
+ * provided, results with no matching UUID should be
+ * dropped. In case there is a match the result is
+ * kept and checking possible scan response data
+ * will be skipped.
+ */
+ if (hdev->discovery.uuid_count > 0) {
+ match = eir_has_uuids(eir, eir_len,
+ hdev->discovery.uuid_count,
+ hdev->discovery.uuids);
+ /* If duplicate filtering does not report RSSI changes,
+ * then restart scanning to ensure updated result with
+ * updated RSSI values.
+ */
+ if (match && test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
+ &hdev->quirks))
+ restart_le_scan(hdev);
+ } else {
+ match = true;
+ }
+
+ if (!match && !scan_rsp_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 false;
+
+ match = false;
+ }
+
+ if (scan_rsp_len > 0) {
+ /* When using service discovery and a list of UUID is
+ * provided, results with no matching UUID should be
+ * dropped if there is no previous match from the
+ * advertising data.
+ */
+ if (hdev->discovery.uuid_count > 0) {
+ if (!match && !eir_has_uuids(scan_rsp, scan_rsp_len,
+ hdev->discovery.uuid_count,
+ hdev->discovery.uuids))
+ return false;
+
+ /* If duplicate filtering does not report RSSI changes,
+ * then restart scanning to ensure updated result with
+ * updated RSSI values.
+ */
+ if (test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
+ &hdev->quirks))
+ restart_le_scan(hdev);
+ }
+ } 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 false;
+ }
+
+ /* Validate the reported RSSI value against the RSSI threshold once more
+ * incase HCI_QUIRK_STRICT_DUPLICATE_FILTER forced a restart of LE
+ * scanning.
+ */
+ 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;
+ 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
@@ -7300,21 +7395,13 @@
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.
- *
- * For BR/EDR devices (pre 1.2) providing no RSSI during inquiry,
- * the results are also dropped.
- */
- if (hdev->discovery.rssi != HCI_RSSI_INVALID &&
- (rssi == HCI_RSSI_INVALID ||
- (rssi < hdev->discovery.rssi &&
- !test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks))))
- 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.
@@ -7341,87 +7428,17 @@
ev->rssi = rssi;
ev->flags = cpu_to_le32(flags);
- if (eir_len > 0) {
- /* When using service discovery and a list of UUID is
- * provided, results with no matching UUID should be
- * dropped. In case there is a match the result is
- * kept and checking possible scan response data
- * will be skipped.
- */
- if (hdev->discovery.uuid_count > 0) {
- match = eir_has_uuids(eir, eir_len,
- hdev->discovery.uuid_count,
- hdev->discovery.uuids);
- /* If duplicate filtering does not report RSSI changes,
- * then restart scanning to ensure updated result with
- * updated RSSI values.
- */
- if (match && test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
- &hdev->quirks))
- restart_le_scan(hdev);
- } else {
- match = true;
- }
-
- if (!match && !scan_rsp_len)
- return;
-
+ if (eir_len > 0)
/* Copy EIR or advertising data into event */
memcpy(ev->eir, eir, eir_len);
- } 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;
-
- 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
- * dropped if there is no previous match from the
- * advertising data.
- */
- if (hdev->discovery.uuid_count > 0) {
- if (!match && !eir_has_uuids(scan_rsp, scan_rsp_len,
- hdev->discovery.uuid_count,
- hdev->discovery.uuids))
- return;
-
- /* If duplicate filtering does not report RSSI changes,
- * then restart scanning to ensure updated result with
- * updated RSSI values.
- */
- if (test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER,
- &hdev->quirks))
- restart_le_scan(hdev);
- }
-
+ if (scan_rsp_len > 0)
/* 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;
- }
-
- /* Validate the reported RSSI value against the RSSI threshold once more
- * incase HCI_QUIRK_STRICT_DUPLICATE_FILTER forced a restart of LE
- * scanning.
- */
- if (hdev->discovery.rssi != HCI_RSSI_INVALID &&
- rssi < hdev->discovery.rssi)
- return;
ev->eir_len = cpu_to_le16(eir_len + scan_rsp_len);
ev_size = sizeof(*ev) + eir_len + scan_rsp_len;