Nice. This does some things very similarly to Hyprspace[1]. The core idea is the same: Receive some bytes from a TUN device, shove them into a network socket, and vice versa. Hyprspace uses libp2p to manage the outer connections between VPN nodes instead of plain UDP, which takes care of addressing, hole punching and encryption.
BTW: You can also use the netlink library to configure the routing table without external processes[2]. The /1 trick isn't necessary either, you can just create a route for 0.0.0.0/0 and set its metric lower than the existing default route. That won't replace the old route in the table, the new one will just take precedence as long as it exists.
Thanks for the comment. Cool stuff you lot are doing on Hyprspace! I agree the usage of `exec.Command` is a bit gnarly, using the netlink library would make it a bit more cleaner.
The suggestion to define a metric lower than that of the existing default route makes sense. But then that would mean I then find out what the default route's metric is by making an extra call where my current implementation does not use that extra call but the outcome is the same? To reduce cognitive complexity, I can understand how your suggestion helps though :), unless there's another thing I am missing?
BTW: You can also use the netlink library to configure the routing table without external processes[2]. The /1 trick isn't necessary either, you can just create a route for 0.0.0.0/0 and set its metric lower than the existing default route. That won't replace the old route in the table, the new one will just take precedence as long as it exists.
[1] https://github.com/hyprspace/hyprspace
[2] https://github.com/hyprspace/hyprspace/blob/a5957e485ff0c2e9...