On 08/24, Luiz Augusto von Dentz wrote: > Hi Konrad, > > On Thu, Aug 24, 2017 at 11:24 AM, Konrad Zapalowicz > <konrad.zapalowicz@xxxxxxxxxxxxx> wrote: > > On 08/24, Luiz Augusto von Dentz wrote: > >> Hi Konrad, > >> > >> On Wed, Aug 23, 2017 at 10:38 PM, Konrad Zapalowicz > >> <konrad.zapalowicz@xxxxxxxxxxxxx> wrote: > >> > Hey, > >> > > >> > I have stumbled upon a problem with one of the BLE devices that I have > >> > on my desk. BlueZ (bluetoothctl) failed to discover the primary services > >> > and the error returned by the Read by Group type request was > >> > "Insufficient Authentication". It did work when using gatttool though. > >> > > >> > I have tracked it down and realized that if calling the > >> > bt_gatt_discover_all_primary_services is delayed until after the pairing > >> > is finished then the primary services are discovered without any issues. > >> > > >> > The simplified bt for bt_gatt_discover_all_primary_services is: > >> > > >> > (gdb) bt > >> > #0 discover_services > >> > #1 bt_gatt_discover_primary_services > >> > #2 bt_gatt_discover_all_primary_services > >> > #3 exchange_mtu_cb > >> > > >> > Now, what would be the best way of approaching this. Calling it could be > >> > delayed with a timer but would it be an optimal solution - thoughts? > >> > >> Sounds to me that the device is requiring authentication for primary > >> services which is not following the spec: > > > > Yes, this is true as well and it is also my concern. Yet at the same > > time I would love to get this device operational. This is a Transport > > Data Logger btw that I'm playing with. > > > >> > >> 4.4.1 Discover All Primary Services > >> ... > >> Note: The service declaration described in Section 3.1 specifies that the > >> service declaration is readable and requires no authentication or authorization, > >> therefore insufficient authentication or read not permitted errors > >> shall not occur. > >> > >> Is this a device already on the market? Perhaps we should contact the > >> manufacturer since it seems to not comply to the spec when it comes to > >> discovery. > >> > >> Delaying is never a nice thing since it affects all devices, but we > >> could perhaps attempt to pair if that happens, actually, we usually do > >> this for regular Read/Write procedures so in case there is an > >> authentication error we pair and try again which might work here as > >> well despite not following the spec. > > > > In the meantime I have cross-checked with the Android code and it does > > things differently. So the services discovery is started in pairing_cb > > that is being called when the pairing is done. I can't tell however if > > this affects interoperability in any way, i.e. has a negative impact > > over Linux implementation. > > Not sure how Android would determine if it needs pairing before > discovering the services, in GATT the pairing is normally done on > demand when there is an authentication error. Though perhaps Android > pairs with any device capable of pairing, anyway the same could be > done with bluetoothctl> pair instead of connect command. > > Btw, even for profiles requiring pairing, like HoG, it hasn't been a > problem to pair on demand though it is probably recommended to pair > first so we don't lose a round trip while accessing the attributes > that would cause the authentication error. Hey, I have taken an approach in refactoring the gatt code in a way that would satisfy the issue I have described previously. To basically do the service search after the connection. I do not have good results so far with it therefore Luiz could you share some suggestions on what would be the best way to tackle it? The reason I ask and proceed with it is that there might be a number of devices on the market that suffer from this and although it is a device's fault these ight not recieve a firmware update. Thanks in advance, K > > > Thanks, > > K > > > >> > >> > Thanks, > >> > K > >> > -- > >> > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > >> > the body of a message to majordomo@xxxxxxxxxxxxxxx > >> > More majordomo info at http://vger.kernel.org/majordomo-info.html > >> > >> > >> > >> -- > >> Luiz Augusto von Dentz > > > > -- > Luiz Augusto von Dentz -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
