Tap abstractions

[andreeaflorescu]

Implement tap abstractions, or find if we can use existing crates (i.e. https://github.com/myrrlyn/tap).

We should be able to mock the tap functionality for testing (this is really important for writing unit tests, and not call read/write on sockets).

[0x00A5]

Hi, it seems a copy of FC's tap device is already in place. Could you please help clarify the remaining work for this issue? Some action items I find are,

• Compare external crate
• If using the existing one, add tests

[andreeaflorescu]

I think a good next step here is to add tests to the Tap abstractions in a way that is not requiring reading and writing on sockets because that would make the unit tests runnable only with TAP_ADMIN permissions and this is not something that we want to do.

Does that make sense?

[0x00A5]

@andreeaflorescu Yep, thanks