Hello,
I am trying to implement GATT services with bluez API.
If external device initiated LE connection to device with bluez
running, bluez start to discover services at initiator and, if one of
characteristics required pairing, request pairing. This is not
intended behaviour for some reason in my case, so I need to disable
GATT client if bluez is not initiator side of the connection, similar
to ReverseServiceDiscovery config option for non-LE.
Is it possible by any way? As i see code, device_attach_att() function
in src/device.c initializes GATT client unconditionally in both cases.
For debug, I disabled client initializing and this seems works for
external-initiated connections.
--
Yauhen Kharuzhy
Hi Yauhen,
On Tue, Mar 19, 2019 at 5:07 PM Yauhen Kharuzhy <[email protected]> wrote:
>
> Hello,
>
> I am trying to implement GATT services with bluez API.
>
> If external device initiated LE connection to device with bluez
> running, bluez start to discover services at initiator and, if one of
> characteristics required pairing, request pairing. This is not
> intended behaviour for some reason in my case, so I need to disable
> GATT client if bluez is not initiator side of the connection, similar
> to ReverseServiceDiscovery config option for non-LE.
>
> Is it possible by any way? As i see code, device_attach_att() function
> in src/device.c initializes GATT client unconditionally in both cases.
> For debug, I disabled client initializing and this seems works for
> external-initiated connections.
We could perhaps reuse the same logic to disable the GATT service
discovery, though the should not cause any pairing request since the
discovery don't actually read any value, apart from characteristic
declaration which shall not require authentication.
--
Luiz Augusto von Dentz
вт, 19 мар. 2019 г. в 23:22, Luiz Augusto von Dentz <[email protected]>:
>
> Hi Yauhen,
>
> On Tue, Mar 19, 2019 at 5:07 PM Yauhen Kharuzhy <[email protected]> wrote:
> >
> > Hello,
> >
> > I am trying to implement GATT services with bluez API.
> >
> > If external device initiated LE connection to device with bluez
> > running, bluez start to discover services at initiator and, if one of
> > characteristics required pairing, request pairing. This is not
> > intended behaviour for some reason in my case, so I need to disable
> > GATT client if bluez is not initiator side of the connection, similar
> > to ReverseServiceDiscovery config option for non-LE.
> >
> > Is it possible by any way? As i see code, device_attach_att() function
> > in src/device.c initializes GATT client unconditionally in both cases.
> > For debug, I disabled client initializing and this seems works for
> > external-initiated connections.
>
> We could perhaps reuse the same logic to disable the GATT service
> discovery, though the should not cause any pairing request since the
> discovery don't actually read any value, apart from characteristic
> declaration which shall not require authentication.
Yes, problem really in BATT profile accept stage:
164 16.407237 localhost (jeknotez) 5c:ca:67:f8:3b:11 ()
ATT 12 Sent Read Request, Handle: 0x0016 (Battery Service:
Battery Level)
166 16.466794 5c:ca:67:f8:3b:11 () localhost (jeknotez)
ATT 14 Rcvd Error Response - Insufficient Encryption, Handle:
0x0016 (Battery Service: Battery Level)
167 16.467125 localhost (jeknotez) 5c:ca:67:f8:3b:11 ()
SMP 11 Sent Security Request: AuthReq: Bonding,
SecureConnection, Reserved
сак 20 13:53:42 jeknotez bluetoothd[4945]:
profiles/battery/battery.c:batt_probe() BATT profile probe
(74:E0:C9:69:D2:8C)
сак 20 13:53:42 jeknotez bluetoothd[4945]:
src/service.c:change_state() 0x5557fcda23b0: device 74:E0:C9:69:D2:8C
profile batt-profile state changed: unavailable -> disconnected (0)
сак 20 13:53:42 jeknotez bluetoothd[4945]:
profiles/battery/battery.c:batt_accept() BATT profile accept
(74:E0:C9:69:D2:8C)
сак 20 13:53:42 jeknotez bluetoothd[4945]:
src/service.c:change_state() 0x5557fcda23b0: device 74:E0:C9:69:D2:8C
profile batt-profile state changed: disconnected -> connected (0)
device_probe_profiles()
...
batt_accept()
gatt_db_foreach_service()
foreach_batt_service()
handle_batt_service()
gatt_db_service_foreach_char()
handle_characteristic()
if (uuid_cmp(GATT_CHARAC_BATTERY_LEVEL, &uuid)) {
handle_battery_level(batt, value_handle);
}
--
Yauhen Kharuzhy