onetun VS tunsocks

Sure, essentially it's a TCP and UDP server that:

- receives connections and assigns a random internal port for it

- wraps the data packets in a transport packet (TCP/UDP)

- wraps the transport in an IP packet that's routed from the internal port and to the remote WireGuard address

- wraps that with WireGuard's protocol (encryption)

- sends off the encrypted packet to the WireGuard UDP endpoint

The packet-wrapping and state machine for the connection is implemented using smoltcp in Rust, which is similar to netstack in Go

The WireGuard encapsulation and state machine is implemented with boringtun, Cloudflare's implementation of the WireGuard client in Rust.

I do have a more thorough architecture explanation in the Readme: https://github.com/aramperes/onetun#architecture

If you use WireGuard instead of Tinc, you can use onetun which is specifically designed for doing this: https://github.com/aramperes/onetun

It's in the plans! I'm going to finish UDP support and multi-port forwarding first and then I'll get to it: https://github.com/aramperes/onetun/issues/6

tunsocks[0] might be of interest to you. It's very similar to the software mentioned by OP except in C. It uses the lwIP usermode tcp/ip stack. It doesn't itself have any VPN or tunneling support, but instead relies on raw packets being passed into and out of a pipe. It can then provide access to that network via various proxies, port forwards, and even raw packets via NAT (very useful for VMs).

[0]: https://github.com/russdill/tunsocks