interfaces.Tailscale only returns an interface if it has at least one Tailscale
IP assigned to it. In the resolved DNS manager, when we're called upon to tear
down DNS config, the interface no longer has IPs.
Instead, look up the interface index on construction and reuse it throughout
the daemon lifecycle.
Fixes#1892.
Signed-off-by: David Anderson <dave@natulte.net>
It seems that all the setups that support split DNS understand
this distinction, and it's an important one when translating
high-level configuration.
Part of #953.
Signed-off-by: David Anderson <danderson@tailscale.com>
wgengine/router.CallbackRouter needs to support both the Router
and OSConfigurator interfaces, so the setters can't both be called
Set.
Signed-off-by: David Anderson <danderson@tailscale.com>
They need some rework to do the right thing, in the meantime the direct
and resolvconf managers will work out.
The resolved implementation was never selected due to control-side settings.
The networkmanager implementation mostly doesn't get selected due to
unforeseen interactions with `resolvconf` on many platforms.
Both implementations also need rework to support the various routing modes
they're capable of.
Signed-off-by: David Anderson <danderson@tailscale.com>
