Bond deletion notification

RE: Bond deletion notification

Petter Myhre — Mon, 05 Oct 2015 13:39:45 GMT

We tried to reproduce this. We used SoftDevice S110 8.0.0 with ble_app_proximity from SDK 9.0.0 and Win 8.1 Desktop with a BLE dongle from CSR. Advertising->Connect->Bond->Disconnect->Whitelist advertising->Connect. It seems to be working fine. Could you try with ble_app_proximity? What kind of BLE dongle are you using?

RE: Bond deletion notification

Valer_I — Fri, 02 Oct 2015 12:36:03 GMT

Already discussed, Bluetooth Core Spec, v4.2. Vol. 3, Part C, Sections 9.2.3 and 9.2.4: "The Host shall set the advertising filter policy to ‘process scan and connection requests from all devices’." with Carles https://devzone.nordicsemi.com/question/51493/whitelist-advertisingconnection-cases/ .

So for whitelist advertising I use BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED and for "simple" advertising BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE.

RE: Bond deletion notification

Petter Myhre — Fri, 02 Oct 2015 12:10:09 GMT

What flags are you setting in the advertisements with whitelist? Could you try setting it to BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE or BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE and see if that helps?

RE: Bond deletion notification

Valer_I — Fri, 02 Oct 2015 11:23:29 GMT

I feel that should be something like

uint16_t         ediv;      /**< Peer's encrypted diversifier. */

to distinguish sequential connections. And if one peer deleted bond while other one not, the divercifier in advertisement will be different and connection won't establish.

RE: Bond deletion notification

Valer_I — Fri, 02 Oct 2015 11:18:20 GMT

The only reason I could imagine is that Microsoft developers made workaround and filtering out whitelist advertising from this peer untill it become general discoverable. However it is vicious way.

RE: Bond deletion notification

Petter Myhre — Fri, 02 Oct 2015 09:24:18 GMT

Very strange.

RE: Bond deletion notification

Valer_I — Fri, 02 Oct 2015 08:40:23 GMT

Nope, I use BLE dongle with my desktop. After deleting bond I replugged the dongle and didn't see the device advertisements. Than I rebonded and repeted experiment without deleting bonding. It works. So Windows works with whitelist correctly I think.

RE: Bond deletion notification

Petter Myhre — Fri, 02 Oct 2015 07:33:48 GMT

Is Win 8.1 able to discover the device if you restart Bluetooth on it?

RE: Bond deletion notification

Valer_I — Thu, 01 Oct 2015 12:51:04 GMT

Ow, in Core 4.2 [Vol 2, Part D], 2.19 REMOTE USER TERMINATED CONNECTION (0x13) "The Remote User Terminated Connection error code indicates that the user on the remote device terminated the connection." This is "very" strict description when remote user allowed to post this message at disconnection.)))

RE: Bond deletion notification

Valer_I — Thu, 01 Oct 2015 12:44:18 GMT

I afraid that BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION disconnection reason could be a trigger for this particular Nexus7 with particular Android version but not for all or even majority of devices. At present time i made application layer command for device to kill bond after disconnection but it vainly for Windows as it do not have API for bonding management.

RE: Bond deletion notification

Valer_I — Thu, 01 Oct 2015 12:37:21 GMT

SD110 v8.0.0. My idea is to delete bonding on device once it deleted on central. Since bond deleted, whitelist becomes empty and there are no need to do advertising. To connect/bond new device I use button pressing event in my app. But now after I deleted bond on central, device become disconnected and restart whitelist advertisement with address of last bonded central(i.e. that one that delete bond). The satrange behaviour demonstrates Win8.1 desktop,after bond deletion it do not show this device in scan list even if device do whitelist adverticement with address of desktop. But do it for advertisement without whitelist.

RE: Bond deletion notification

Petter Myhre — Thu, 01 Oct 2015 10:42:58 GMT

Are you advertising with a whitelist on disconnect? What SoftDevice version are you using?

RE: Bond deletion notification

Petter Myhre — Thu, 01 Oct 2015 10:42:22 GMT

I don't think there is any built in procedure in the Bluetooth specification for doing this. Yes, you could trigger a bond deletion when you get the BLE_GAP_EVT_DISCONNECTED with BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION, but this doesn't really tell you if the bond on the central side is deleted or not.

If this is a feature you need I think you need to build it into the application space and make the central use GATT to tell the peripheral that it should delete the bond.

Edit 02.10.2015: I gave this some more thought. There are ways of checking if the central has deleted the bond, but then you need to reconnect first.

Then you have two scenarioes.

That the central initiates the procedures. The central can do this whenever it wants, or when it does service discovery and tries to read an characteristic value or descriptor that requires encryption. If the central has a bond it will send an encryption request, and the peripheral applicaiton will receive the BLE_GAP_EVT_SEC_INFO_REQUEST event, see this for more information. If the central doesn't have a bond it will send an pairing request, and the peripheral application will receive the BLE_GAP_EVT_SEC_PARAMS_REQUEST event, see this for more information. If BLE_GAP_EVT_SEC_PARAMS_REQUEST is received the peripheral can check its list of bonded devices and delete the appropriate bond.

The second is that the peripheral initiates the procedures. It can call sd_ble_gap_authenticate() and then you get into the same situation as above, and then you can take the appropriate action depending if you receive BLE_GAP_EVT_SEC_INFO_REQUEST or BLE_GAP_EVT_SEC_PARAMS_REQUEST.

RE: Bond deletion notification

Valer_I — Wed, 30 Sep 2015 13:20:20 GMT

The second one, I need to know whether peer central deleted bond info on it's side at disconnection or not to trigger deletion of the correspondent bond info on the peripheral side.

RE: Bond deletion notification

Petter Myhre — Wed, 30 Sep 2015 12:43:54 GMT

I'm not sure I understand what your question is. Are you asking how you can delete a bond? Or are you asking how to trigger a deletion of a bond?