add PKI uplink and downlink options

[jp-bennett]

Seems like we'll want the switches to control PKI uplink and downlink via MQTT

[GUVWAF]

There's already an "encryption_enabled" setting in the MQTT config. Can't we follow that?

[jp-bennett]

There's already an "encryption_enabled" setting in the MQTT config. Can't we follow that?

We're treating PKI as a separate channel, so this setting follows the per-channel MQTT settings. I'm not sure how exactly that would map to encryption_enabled.

[GUVWAF]

"encryption_enabled" applies to all packets sent to the MQTT server, no matter which channel. I think we can just follow the same logic for PKI?

[ianmcorvidae]

I believe these new settings aren't for whether the uploaded packets are encrypted or not (with PKI they always are), it's for whether they're uplinked/downlinked to/from MQTT at all. Since the new PKI DMs use different keys, they're effectively "channel-less", so these options are the equivalent of the "uplink enabled" and "downlink enabled" that's on each channel, but for these new messages instead.

[ianmcorvidae]

(or to put it more simply, maybe: if we followed encryption_enabled, then you would be unable to have both encrypted channel messages uplinked & PKI DMs not uplinked; you also wouldn't be able to have PKI messages uplink-only or downlink-only)

[GUVWAF]

Summary of my points on Discord: currently we also don't have granular settings for uplinking/downlinking DMs and I believe this will be confusing because when you discover a node, you expect you can also DM it.
So if we want to reproduce the current behavior, we would need to uplink/downlink DMs that would otherwise have been sent over a channel we have uplink/downlink enabled. To avoid uplinking/downlinking every DM in an MQTT root topic, I think the best we can do is to check whether you have at least one channel uplink/downlink enabled and both the sender and receiver of the packet in your NodeDB, as then it's likely they share a channel you have uplink/downlink enabled on.

[jp-bennett]

Shelving this for now.