Adds the eventbus to the router subsystem.
The event is currently only used on linux.
Also includes facilities to inject events into the bus.
Updates #15160
Signed-off-by: Claus Lensbøl <claus@tailscale.com>
The regular android app constructs its own wgengine with
additional FFI shims, so this default codepath only affects
other handcrafted buids like tsnet, which do not let the
caller customize the innards of wgengine.
Android >=14 forbids the use of netlink sockets, which makes
the standard linux router fail to initialize.
Fixes#9836
Signed-off-by: David Anderson <dave@tailscale.com>
Claus Lensbøl
David Anderson