Add WireGuard VPN usermod

[acvigue]

Adds a WireGuard usermod for ESP32 that allows WLED devices to join a remote network in situations where wireless isolation prevents local control.

[acvigue]

Is there any chance someone could take a quick look at this?

Thank you all!

[blazoncek]

I have no way of testing it so I trust it works for you.
There are some things I'd like you to address before merging, though.

[blazoncek]

One more thing: Please add your contact info into readme.md for user reference in case someone needs help with usermod.

[acvigue]

Can you look at the changes I made?

[blazoncek]

Using char[xx] eats a lot of stack, which is limited on MCU.
It may interfere with WLED behaviour (which itself uses a lot of stack space on some occasions) so it would be better to use new or malloc() for all the strings you want to store in setup() or readFromConfig().

Otherwise I see you updated as requested and see no objection to this usermod.

[acvigue]

fixed

[blazoncek]

Are you sure this works?
setup() is called after readFromConfig(). So malloc() happens after all strncpy() which is not good.

I may have unintentionally mislead you when I suggested setup(). Constructor would be a better place, and then free() in destructor. Sorry about that.

[acvigue]

So malloc() happens after all strncpy() which is not good.

Oops, ok. I'll take a look at fixing it tomorrow.

[Aircoookie]

Hmm, correct me if I'm wrong, but since these keys are private members, they are created on the heap anyways as the usermod constructor is called in usermods_list.cpp. Stack would only be used if they are local variables in a given function.
Sorry that I'm only taking a look at it now, but to me this seems fine as implemented in 7296e87 ...
Either way as this is an ESP32-only mod, memory usage is far less of a concern than with mods intended for ESP8266 as well.

[acvigue]

Sorry that I'm only taking a look at it now, but to me this seems fine as implemented in 7296e87 ...
Either way as this is an ESP32-only mod, memory usage is far less of a concern than with mods intended for ESP8266 as well.

All good, thanks for the input. I went ahead and reverted my branch back to that commit and then merged in all the changes from main so it should be good to go.

[blazoncek]

they are created on the heap anyways

You are correct and I was wrong. Mea culpa.

[Aircoookie]

All good :) I'd say this is ready to merge!