Support for macOS feth devices

[Peter Stuge]

Charles Celerier wrote:
> I have not yet gone far enough to try and integrate the ZeroTierOne code
> with my own ssh build, but I'm curious what thoughts others may have on
> this mailing list.

Large-scale, the license will be a problem.

https://github.com/zerotier/ZeroTierOne/blob/98af3c0dc192ea89df797dd45df7d7efe5ad3d09/osdep/MacEthernetTapAgent.c

is GPL-licensed, so a derivative of that can't be integrated into OpenSSH.

ZeroTierOne later relicensed their code under the "Business Source License"
of which I haven't heard yet, and in 2023 it'll change again to Apache 2.
I think that's all a problem for public distribution, but of course no
problem for a local solution.

It's unfortunate that there was a lot of effort to understand how the
Apple kernel works, but that only code was published.

It would be helpful if someone published documentation, like a blog post,
with all the technical details required to use this kernel API. That
would enable the creation of a BSD-licensed/-compatible implementation.


//Peter