[openwrt] Make wwan modem backend interchangeable

[feckert]

Up to now only the modem manager is supported to get information from them wwan modem. Not all system does have a modem manager instance running. There are the following other backends

• uqmi
• mbim
• 3g

So far, there is no uniform way to read the information from these different backends. The needed information are not all the same. We would have to agree on the smallest common set here.

I would suggest an ubus interface that provides the necessary information. Then there would be no need to go to the trouble of collecting this information from the different backends system. The ubus interface then takes over the collection of the information. The openwisp-monitoring then only calls the ubus endpoint and returns what is there.

[nemesifier]

Up to now only the modem manager is supported to get information from them wwan modem. Not all system does have a modem manager instance running. There are the following other backends

• uqmi
• mbim
• 3g

So far, there is no uniform way to read the information from these different backends. The needed information are not all the same. We would have to agree on the smallest common set here.

I would suggest an ubus interface that provides the necessary information. Then there would be no need to go to the trouble of collecting this information from the different backends system. The ubus interface then takes over the collection of the information. The openwisp-monitoring then only calls the ubus endpoint and returns what is there.

@feckert, is it possible to write an ubus module that retrieves this info in an independent way from the modem software used?
If yes, it would be great! Is this something which we would have to develop in a separate module?