Apply missing node features after receiving composition data

[kkellermann]

This PR revises the processing of the composition data in the case of the node features. The current implementation discarded newly-received node features if NodeFeaturesState was already set once. In this PR, the individual node features are now checked for nil and, if necessary, replaced by the newly received composition data.

[CLAassistant]

All committers have signed the CLA.

[philips77]

Hello,
May I ask what is the intention for the change? Do you first read statuses of different features before reading Composition Data?

[philips77]

And sorry for the long response time. I didn't notice your PR during the holiday period.

[kkellermann]

Hello,

And sorry for the long response time. I didn't notice your PR during the holiday period.

no problem.

May I ask what is the intention for the change? Do you first read statuses of different features before reading Composition Data?

our nodes sometimes have large composition data and when we connect to another node as a proxy, we have some problems receiving the composition data. Now we enable the proxy after the provisioning. With an enabled proxy we are connecting us directly to the node to get a higher success rate for receiving the Data. However, the enabled proxy has the effect of initialising the node features. After that, there was no way to update the other features such as the friends feature.

[philips77]

Do you read Composition Data Page 0 before you connect to that node using GATT bearer? Is the Proxy feature disabled at that moment?

[kkellermann]

No, we do not read Page 0 until we are connected to the GATT bearer. After provisioning, the node's proxy is disabled by default. So, we first send the message to enable the proxy. If the proxy is enabled, we connect directly to the node so that a message does not have to be routed through multiple nodes. With a direct connection, we request Page 0, which leads to a higher success rate.

[philips77]

OK, I finally get it now. By sending ConfigGATTProxySet and receiving ConfigGATTProxyStatus the features property is created with default values:
https://github.com/NordicSemiconductor/IOS-nRF-Mesh-Library/blob/3c6cde5f07929872d11542dd27441776bf697580/nRFMeshProvision/Layers/Foundation%20Layer/ConfigurationClientHandler.swift#L313-L317
where ensureFeatures is:
https://github.com/NordicSemiconductor/IOS-nRF-Mesh-Library/blob/3c6cde5f07929872d11542dd27441776bf697580/nRFMeshProvision/Mesh%20Model/Node.swift#L895-L901

Then, the features received in the Composition Data are not applied, as the object exist.

[kkellermann]

Then, the features received in the Composition Data are not applied, as the object exist.

Correct, that was the problem.
After requesting the Composition Data, we run some configurations for the node, such as enabling/disabling friend or secure network beaconing feature. But if the node functions are not applied within the Composition Data, we do not know whether the feature such as the friend feature is supported or not.

Do you see any problems with the adjustments of this PR?

[philips77]

The only issue I can imagine is that the Composition Data should not change, that's why there's this check.
Actually, as I discussed here, perhaps it would be better to discard new completely when cid is already known, that is if Page 0 was applied.

But anyway, your suggestion is OK. I'll merge the PR when I'm done with my current changes.