Remote provisioning link open timeout not triggering

RE: Remote provisioning link open timeout not triggering

rmarques — Fri, 11 Jun 2021 07:54:45 GMT

Thank you for the advice Mttrinh, we will do this.

RE: Remote provisioning link open timeout not triggering

Mttrinh — Thu, 10 Jun 2021 13:09:26 GMT

Hi,

This seems to be true. I see that PB Remote Client messages are acked after they are forwarded by PB Remote Server to PB-ADV, but the reply on those messages comes independently of the reply on the PB Remote Client message. This looks like an omission from the PB Remote protocol side.

So, it might actually be a right thing to run timer in pb_if_link_open_cb in pb_remote_client.c setting the timeout to some reasonable time which is 2-3 times bigger than the provisioning link timeout.

RE: Remote provisioning link open timeout not triggering

rmarques — Tue, 08 Jun 2021 16:06:26 GMT

Thank you for the useful information as always Mttrinh, we will activate those logs and check what may be happening.

In the meantime, what do you think will happen if the server times out, triggers the link close callback but the reliable message never reaches the remote provisioner client?

I suspect this might be happening in our case. Will the client be eternally waiting for the server to say something?

RE: Remote provisioning link open timeout not triggering

Mttrinh — Tue, 08 Jun 2021 13:42:53 GMT

Hi,

The timeout passed link_open callback is the timeout of the provisioning link, which is the link between the provisioner and an unprovisioned device. In case of PB Remote, this is the link between PB Remote Server and an unprovisioned device. The link between PB Remote Client and PB Remote Server doesn't use this timeout, but instead relies on the PB Remote protocol. This is because PB Remote Client doesn't really know when PB Remote Server established the provisioning link and thus can't manage the timeout correctly. PB Remote Client and Server use reliable messages to exchange the data, so that if the message has not been received by one of the side, it will terminate the remote provisioning process. Since PB-ADV on the PB Remote Server side still uses the timeout, it will call pb_adv_link_closed_cb if link has been timed out (https://github.com/NordicSemiconductor/nRF5-SDK-for-Mesh/blob/master/mesh/prov/src/prov_bearer_adv.c#L290). This will go to pb_remote_server_event_link_closed_cb (https://github.com/NordicSemiconductor/nRF5-SDK-for-Mesh/blob/master/models/proprietary/pb_remote/src/pb_remote_server.c#L686), which in turns will send a message to PB Remote Client.

Can you check that what I described actually happens on your side and what is PB Remote Server and Client states? If you could provide logs with LOG_SRC_ACCESS | LOG_SRC_BEARER and LOG_LEVEL_DBG3, this might also be helpful.

RE: Remote provisioning link open timeout not triggering

rmarques — Mon, 07 Jun 2021 17:15:26 GMT

So, this is my idea:

Inside pb_if_link_open_cb I start a timer that triggers a callback that tries to close the link after NRF_MESH_PROV_LINK_TIMEOUT_MIN_US microseconds. This timer is restarted every time a PDU is processed in pb_remote_client_process and is stopped somewhere when the provisioning is complete, probably in prov_evt_handler in my provisioner_helper.c file, on the NRF_MESH_PROV_EVT_LINK_CLOSED case. Am I on the right track?