-Only one of secnet-address or ptp-address may be specified. If
-point-to-point mode is in use then precisely one tunnel must register
-with the netlink device.
+Only one of secnet-address or ptp-address may be specified. If
+point-to-point mode is in use then the "routes" option must also be
+specified, and netlink returns a netlink closure that should be used
+directly with the "link" option to the site closure. If
+point-to-point mode is not in use then netlink returns a closure that
+may be invoked using a dict argument with the following keys to yield
+a netlink closure:
+ routes (string list): networks reachable down the tunnel attached to
+ this instance of netlink
+ options (string list):
+ allow-route: allow packets coming from this tunnel to be routed to
+ other tunnels as well as the host (used for mobile devices like laptops)
+ soft-route: remove these routes from the host's routing table when
+ the tunnel link quality is zero
+ mtu (integer): default MTU over this link; may be updated by tunnel code