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>

1 files changed, 79 insertions, 62 deletions

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 1e4635a3374d..a41a5efa4391 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -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;