Add support for Freebsd

[cloudflare]

Add support for Freebsd

[decke]

I've created a FreeBSD Port for boringtun and included the patch from PR #35 - seems to build fine on FreeBSD 11.2 and 12.0 but I haven't done any runtime testing yet.

https://code.bluelife.at/decke/ports/src/branch/master/net/boringtun

[vkrasnov]

Cool. Yes it builds but we need to make it work with the CI to have official support. Also I wan to land sendmmsg and recvmmsg before FreeBSD as it provides significant performance benefits there.

[decke]

Don't know if it is an option but cirrus-ci.org has FreeBSD support and is free for open source projects.

[vkrasnov]

The problem is that there are interop tests that interact with wireguard-go in a container, and although there is experimental docker support on FreeBSD, wireguard refuses to work there. But maybe I just need to use a native container.

[lwhsu]

We also have wireguard-go on FreeBSD, although there is no container, it might still be possible to run those test scripts on Cirrus-CI's FreeBSD instance.

[BlameOmar]

It looks like #35 has stalled for nearly a year and has merge conflicts now. I'm interested in getting this working, but I don't know what's blocking it.

[vkrasnov]

The only thing blocking it is lack of CI server for FreeBSD

[BlameOmar]

From what I can tell, that's because:

• The integration tests depend on Docker. Specifically, two methods on Peer execute docker.
• Docker is not supported on FreeBSD. It's not clear if it ever will be.

Perhaps a path forward would be to assume Docker will never be supported on FreeBSD and factor out the Docker dependency from Peer, using jails on FreeBSD and Docker everywhere else.

If this is fine, I can file a bug for factoring out the Docker dependency and then take a look at a jails implementation ~Saturday. Otherwise, I suppose I can just run a tiny linux VM for kernel-space wireguard.

[vkrasnov]

@BlameOmar it would be awesome to have a jails based test suite