package main import ( "errors" "net" ) type UDPBind interface { SetMark(value uint32) error ReceiveIPv6(buff []byte, end *Endpoint) (int, error) ReceiveIPv4(buff []byte, end *Endpoint) (int, error) Send(buff []byte, end *Endpoint) error Close() error } func parseEndpoint(s string) (*net.UDPAddr, error) { // ensure that the host is an IP address host, _, err := net.SplitHostPort(s) if err != nil { return nil, err } if ip := net.ParseIP(host); ip == nil { return nil, errors.New("Failed to parse IP address: " + host) } // parse address and port addr, err := net.ResolveUDPAddr("udp", s) if err != nil { return nil, err } return addr, err } /* Must hold device and net lock */ func unsafeCloseUDPListener(device *Device) error { var err error netc := &device.net if netc.bind != nil { err = netc.bind.Close() netc.bind = nil netc.update.Add(1) } return err } // must inform all listeners func UpdateUDPListener(device *Device) error { device.mutex.Lock() defer device.mutex.Unlock() netc := &device.net netc.mutex.Lock() defer netc.mutex.Unlock() // close existing sockets if err := unsafeCloseUDPListener(device); err != nil { return err } // assumption: netc.update WaitGroup should be exactly 1 // open new sockets if device.tun.isUp.Get() { // bind to new port var err error netc.bind, netc.port, err = CreateUDPBind(netc.port) if err != nil { netc.bind = nil return err } // set mark err = netc.bind.SetMark(netc.fwmark) if err != nil { return err } // clear cached source addresses for _, peer := range device.peers { peer.mutex.Lock() peer.endpoint.value.ClearSrc() peer.mutex.Unlock() } // decrease waitgroup to 0 device.log.Debug.Println("UDP bind has been updated") netc.update.Done() } return nil } func CloseUDPListener(device *Device) error { device.mutex.Lock() device.net.mutex.Lock() err := unsafeCloseUDPListener(device) device.net.mutex.Unlock() device.mutex.Unlock() return err }