package udp import ( "io" "net" "github.com/containous/traefik/v2/pkg/log" ) // Proxy is a reverse-proxy implementation of the Handler interface. type Proxy struct { // TODO: maybe optimize by pre-resolving it at proxy creation time target string } // NewProxy creates a new Proxy func NewProxy(address string) (*Proxy, error) { return &Proxy{target: address}, nil } // ServeUDP implements the Handler interface. func (p *Proxy) ServeUDP(conn *Conn) { log.Debugf("Handling connection from %s", conn.rAddr) // needed because of e.g. server.trackedConnection defer conn.Close() connBackend, err := net.Dial("udp", p.target) if err != nil { log.Errorf("Error while connecting to backend: %v", err) return } // maybe not needed, but just in case defer connBackend.Close() errChan := make(chan error) go p.connCopy(conn, connBackend, errChan) go p.connCopy(connBackend, conn, errChan) err = <-errChan if err != nil { log.WithoutContext().Errorf("Error while serving UDP: %v", err) } <-errChan } func (p Proxy) connCopy(dst io.WriteCloser, src io.Reader, errCh chan error) { _, err := io.Copy(dst, src) errCh <- err if err := dst.Close(); err != nil { log.WithoutContext().Debugf("Error while terminating connection: %v", err) } }