The go turnOff code waits for all readers to have completed. In order to
make readers complete, we must send the signal to unblock the request.
Thus, we must reorder these.
The app figures out all settings and passes them in the
'options' parameter of startTunnel().
The network extension just takes them as is and just plugs the supplied
values into the right places.
Roopesh Chander
Jason A. Donenfeld