discovery_filter_to_mgmt_cp() does not add discovery_filter.discoverable
to the created mgmt_cp_start_service_discovery struct.
Instead update_discovery_filter() separately checks
client->discovery_filter->discoverable for all clients.
This means that for discovery-filters which only have the discoverable
flag set, to put the adapter in discoverable mode while discovering,
the created mgmt_cp_start_service_discovery struct is empty.
This empty mgmt_cp_start_service_discovery struct then gets sent
to the kernel as part of a MGMT_OP_START_SERVICE_DISCOVERY msg
by start_discovery_timeout().
This use of an empty filter with MGMT_OP_START_SERVICE_DISCOVERY
causes some bluetooth devices to not get seen with some (most?)
Broadcom bluetooth adapters. This problem has been observed with
the following Broadcom models: BCM4343A0, BCM43430A1, BCM43341B0 .
On these models the following 2 devices were not being discovered
when starting a scan with a filter with just discoverable set
in the filter (as gnome-bluetooth does):
Device 09:02:01:03:0F:87 (public)
Name: Bluetooth 3.0 Keyboard
Alias: Bluetooth 3.0 Keyboard
Class: 0x00000540
Icon: input-keyboard
Paired: yes
Bonded: yes
Trusted: yes
Blocked: no
Connected: yes
WakeAllowed: yes
LegacyPairing: yes
UUID: Service Discovery Serve.. (00001000-0000-1000-8000-00805f9b34fb)
UUID: Human Interface Device... (00001124-0000-1000-8000-00805f9b34fb)
UUID: PnP Information (00001200-0000-1000-8000-00805f9b34fb)
Modalias: bluetooth:v05ACp022Cd011B
Device 00:60:D1:00:00:34 (public)
Name: Bluetooth Mouse
Alias: Bluetooth Mouse
Class: 0x00002580
Icon: input-mouse
Paired: yes
Bonded: yes
Trusted: yes
Blocked: no
Connected: yes
WakeAllowed: yes
LegacyPairing: no
UUID: Human Interface Device... (00001124-0000-1000-8000-00805f9b34fb)
UUID: PnP Information (00001200-0000-1000-8000-00805f9b34fb)
Modalias: usb:v0103p0204d001E
Since setting the discoverable flag on a filter only is a way to
automatically put the adapter in discoverable mode itself while
it is discovering; and since this does not any device filtering
at all; modify merge_discovery_filters() to treat discovery with
such filters as regular unfiltered discovery.
This results in start_discovery_timeout() starting regular
discovery through a MGMT_OP_START_DISCOVERY message and this
fixes these 2 example devices not getting discovered by the
mentioned Broadcom BT adapter models.
Link: https://gitlab.gnome.org/GNOME/gnome-bluetooth/-/merge_requests/163
Reviewed-by: Bastien Nocera <hadess@xxxxxxxxxx>
---
Note the same argument can be made for the pattern and duplicate part of
the filters which also get handled outside of the kernel filter.
But I prefer to keep the first patch small and targetted at solving things
not working with the gnome-bluetooth filter settings.
Also I'm not familiar enough with the code to say with certainty that
filters with just a pattern or the duplicate flag set (or a combination)
should also be treated as unfiltered discovery.
---
Changes in v2:
- Fix a couple of typos / grammar errors in the commit message
- Replace hard-tabs in commit message with spaces
- Add Bastien's Reviewed-by tag
---
src/adapter.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/src/adapter.c b/src/adapter.c
index 7947160a6..cc7f891d9 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -2192,6 +2192,7 @@ static int merge_discovery_filters(struct btd_adapter *adapter, int *rssi,
bool empty_uuid = false;
bool has_regular_discovery = false;
bool has_filtered_discovery = false;
+ uint8_t adapter_scan_type = get_scan_type(adapter);
for (l = adapter->discovery_list; l != NULL; l = g_slist_next(l)) {
struct discovery_client *client = l->data;
@@ -2202,6 +2203,20 @@ static int merge_discovery_filters(struct btd_adapter *adapter, int *rssi,
continue;
}
+ /*
+ * Detect empty filter with only discoverable
+ * (which does not require a kernel filter) set.
+ */
+ if (item->uuids == NULL &&
+ item->pathloss == DISTANCE_VAL_INVALID &&
+ item->rssi == DISTANCE_VAL_INVALID &&
+ item->type == adapter_scan_type &&
+ item->duplicate == false &&
+ item->pattern == NULL) {
+ has_regular_discovery = true;
+ continue;
+ }
+
has_filtered_discovery = true;
*transport |= item->type;
@@ -2251,7 +2266,7 @@ static int merge_discovery_filters(struct btd_adapter *adapter, int *rssi,
* It there is both regular and filtered scan running, then
* clear whole fitler to report all devices.
*/
- *transport = get_scan_type(adapter);
+ *transport = adapter_scan_type;
*rssi = HCI_RSSI_INVALID;
g_slist_free(*uuids);
*uuids = NULL;
--
2.39.1
