TCP fallback tunneling is now working. That hurt more than expected.

service/OneService.hpp

@@ -126,6 +126,11 @@ public:
 	 */
 	virtual std::string portDeviceName(uint64_t nwid) const = 0;
 
+	/**
+	 * @return True if TCP fallback is currently active
+	 */
+	virtual bool tcpFallbackActive() const = 0;
+
 	/**
 	 * Terminate background service (can be called from other threads)
 	 */