Bluetooth: Add framework for device found filtering based on UUID

Using Start Service Discovery provides the option to specifiy a list
of UUID that are used to filter out device found events. This patch
provides the framework for hooking up the UUID filter.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 1715c91..e39190a 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -6802,6 +6802,11 @@ void mgmt_read_local_oob_data_complete(struct hci_dev *hdev, u8 *hash192,
        mgmt_pending_remove(cmd);
 }
 
+static bool eir_has_uuids(u8 *eir, u16 eir_len, u16 uuid_count, u8 (*uuids)[16])
+{
+       return false;
+}
+
 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)
@@ -6809,6 +6814,7 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
        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
@@ -6843,15 +6849,59 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
        ev->rssi = rssi;
        ev->flags = cpu_to_le32(flags);
 
-       if (eir_len > 0)
+       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 (!match)
+                               return;
+               }
+
+               /* 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)
+                       return;
+       }
 
        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)
+       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;
+               }
+
+               /* 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;
+       }
 
        ev->eir_len = cpu_to_le16(eir_len + scan_rsp_len);
        ev_size = sizeof(*ev) + eir_len + scan_rsp_len;