2 files changed, 49 insertions, 5 deletions

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index d3a232be9d9b..52863c3e0b13 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1334,6 +1334,7 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event);
 #define DISCOV_INTERLEAVED_TIMEOUT      5120    /* msec */
 #define DISCOV_INTERLEAVED_INQUIRY_LEN  0x04
 #define DISCOV_BREDR_INQUIRY_LEN        0x08
+#define DISCOV_LE_RESTART_DELAY         msecs_to_jiffies(200)   /* msec */
 
 int mgmt_control(struct sock *sk, struct msghdr *msg, size_t len);
 int mgmt_new_settings(struct hci_dev *hdev);
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 8c2520a7f386..9e50b5c09b02 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -7262,6 +7262,21 @@ static bool eir_has_uuids(u8 *eir, u16 eir_len, u16 uuid_count, u8 (*uuids)[16])
         return false;
 }
 
+static void restart_le_scan(struct hci_dev *hdev)
+{
+        /* If controller is not scanning we are done. */
+        if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+                return;
+
+        if (time_after(jiffies + DISCOV_LE_RESTART_DELAY,
+                       hdev->discovery.scan_start +
+                       hdev->discovery.scan_duration))
+                return;
+
+        queue_delayed_work(hdev->workqueue, &hdev->le_scan_restart,
+                           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)
@@ -7284,14 +7299,18 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 
         /* When using service discovery with a RSSI threshold, then check
          * if such a RSSI threshold is specified. If a RSSI threshold has
-         * been specified, then all results with a RSSI smaller than the
-         * RSSI threshold will be dropped.
+         * 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 < hdev->discovery.rssi || rssi == HCI_RSSI_INVALID))
+            (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
@@ -7326,12 +7345,20 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
                  * kept and checking possible scan response data
                  * will be skipped.
                  */
-                if (hdev->discovery.uuid_count > 0)
+                if (hdev->discovery.uuid_count > 0) {
                         match = eir_has_uuids(eir, eir_len,
                                               hdev->discovery.uuid_count,
                                               hdev->discovery.uuids);
-                else
+                        /* 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;
@@ -7364,6 +7391,14 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
                                                      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);
                 }
 
                 /* Append scan response data to event */
@@ -7377,6 +7412,14 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
                         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;