Update deps

vendor/github.com/miekg/dns/server.go

@@ -72,9 +72,10 @@ type response struct {
 	tsigStatus     error
 	tsigRequestMAC string
 	tsigSecret     map[string]string // the tsig secrets
-	udp            *net.UDPConn      // i/o connection if UDP was used
+	udp            net.PacketConn    // i/o connection if UDP was used
 	tcp            net.Conn          // i/o connection if TCP was used
 	udpSession     *SessionUDP       // oob data to get egress interface right
+	pcSession      net.Addr          // address to use when writing to a generic net.PacketConn
 	writer         Writer            // writer to output the raw DNS bits
 }
 
@@ -147,12 +148,24 @@ type Reader interface {
 	ReadUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *SessionUDP, error)
 }
 
-// defaultReader is an adapter for the Server struct that implements the Reader interface
-// using the readTCP and readUDP func of the embedded Server.
+// PacketConnReader is an optional interface that Readers can implement to support using generic net.PacketConns.
+type PacketConnReader interface {
+	Reader
+
+	// ReadPacketConn reads a raw message from a generic net.PacketConn UDP connection. Implementations may
+	// alter connection properties, for example the read-deadline.
+	ReadPacketConn(conn net.PacketConn, timeout time.Duration) ([]byte, net.Addr, error)
+}
+
+// defaultReader is an adapter for the Server struct that implements the Reader and
+// PacketConnReader interfaces using the readTCP, readUDP and readPacketConn funcs
+// of the embedded Server.
 type defaultReader struct {
 	*Server
 }
 
+var _ PacketConnReader = defaultReader{}
+
 func (dr defaultReader) ReadTCP(conn net.Conn, timeout time.Duration) ([]byte, error) {
 	return dr.readTCP(conn, timeout)
 }
@@ -161,8 +174,14 @@ func (dr defaultReader) ReadUDP(conn *net.UDPConn, timeout time.Duration) ([]byt
 	return dr.readUDP(conn, timeout)
 }
 
+func (dr defaultReader) ReadPacketConn(conn net.PacketConn, timeout time.Duration) ([]byte, net.Addr, error) {
+	return dr.readPacketConn(conn, timeout)
+}
+
 // DecorateReader is a decorator hook for extending or supplanting the functionality of a Reader.
 // Implementations should never return a nil Reader.
+// Readers should also implement the optional PacketConnReader interface.
+// PacketConnReader is required to use a generic net.PacketConn.
 type DecorateReader func(Reader) Reader
 
 // DecorateWriter is a decorator hook for extending or supplanting the functionality of a Writer.
@@ -325,24 +344,22 @@ func (srv *Server) ActivateAndServe() error {
 
 	srv.init()
 
-	pConn := srv.PacketConn
-	l := srv.Listener
-	if pConn != nil {
+	if srv.PacketConn != nil {
 		// Check PacketConn interface's type is valid and value
 		// is not nil
-		if t, ok := pConn.(*net.UDPConn); ok && t != nil {
+		if t, ok := srv.PacketConn.(*net.UDPConn); ok && t != nil {
 			if e := setUDPSocketOptions(t); e != nil {
 				return e
 			}
-			srv.started = true
-			unlock()
-			return srv.serveUDP(t)
 		}
-	}
-	if l != nil {
 		srv.started = true
 		unlock()
-		return srv.serveTCP(l)
+		return srv.serveUDP(srv.PacketConn)
+	}
+	if srv.Listener != nil {
+		srv.started = true
+		unlock()
+		return srv.serveTCP(srv.Listener)
 	}
 	return &Error{err: "bad listeners"}
 }
@@ -446,18 +463,24 @@ func (srv *Server) serveTCP(l net.Listener) error {
 }
 
 // serveUDP starts a UDP listener for the server.
-func (srv *Server) serveUDP(l *net.UDPConn) error {
+func (srv *Server) serveUDP(l net.PacketConn) error {
 	defer l.Close()
 
-	if srv.NotifyStartedFunc != nil {
-		srv.NotifyStartedFunc()
-	}
-
 	reader := Reader(defaultReader{srv})
 	if srv.DecorateReader != nil {
 		reader = srv.DecorateReader(reader)
 	}
 
+	lUDP, isUDP := l.(*net.UDPConn)
+	readerPC, canPacketConn := reader.(PacketConnReader)
+	if !isUDP && !canPacketConn {
+		return &Error{err: "PacketConnReader was not implemented on Reader returned from DecorateReader but is required for net.PacketConn"}
+	}
+
+	if srv.NotifyStartedFunc != nil {
+		srv.NotifyStartedFunc()
+	}
+
 	var wg sync.WaitGroup
 	defer func() {
 		wg.Wait()
@@ -467,7 +490,17 @@ func (srv *Server) serveUDP(l *net.UDPConn) error {
 	rtimeout := srv.getReadTimeout()
 	// deadline is not used here
 	for srv.isStarted() {
-		m, s, err := reader.ReadUDP(l, rtimeout)
+		var (
+			m    []byte
+			sPC  net.Addr
+			sUDP *SessionUDP
+			err  error
+		)
+		if isUDP {
+			m, sUDP, err = reader.ReadUDP(lUDP, rtimeout)
+		} else {
+			m, sPC, err = readerPC.ReadPacketConn(l, rtimeout)
+		}
 		if err != nil {
 			if !srv.isStarted() {
 				return nil
@@ -484,7 +517,7 @@ func (srv *Server) serveUDP(l *net.UDPConn) error {
 			continue
 		}
 		wg.Add(1)
-		go srv.serveUDPPacket(&wg, m, l, s)
+		go srv.serveUDPPacket(&wg, m, l, sUDP, sPC)
 	}
 
 	return nil
@@ -546,8 +579,8 @@ func (srv *Server) serveTCPConn(wg *sync.WaitGroup, rw net.Conn) {
 }
 
 // Serve a new UDP request.
-func (srv *Server) serveUDPPacket(wg *sync.WaitGroup, m []byte, u *net.UDPConn, s *SessionUDP) {
-	w := &response{tsigSecret: srv.TsigSecret, udp: u, udpSession: s}
+func (srv *Server) serveUDPPacket(wg *sync.WaitGroup, m []byte, u net.PacketConn, udpSession *SessionUDP, pcSession net.Addr) {
+	w := &response{tsigSecret: srv.TsigSecret, udp: u, udpSession: udpSession, pcSession: pcSession}
 	if srv.DecorateWriter != nil {
 		w.writer = srv.DecorateWriter(w)
 	} else {
@@ -659,6 +692,24 @@ func (srv *Server) readUDP(conn *net.UDPConn, timeout time.Duration) ([]byte, *S
 	return m, s, nil
 }
 
+func (srv *Server) readPacketConn(conn net.PacketConn, timeout time.Duration) ([]byte, net.Addr, error) {
+	srv.lock.RLock()
+	if srv.started {
+		// See the comment in readTCP above.
+		conn.SetReadDeadline(time.Now().Add(timeout))
+	}
+	srv.lock.RUnlock()
+
+	m := srv.udpPool.Get().([]byte)
+	n, addr, err := conn.ReadFrom(m)
+	if err != nil {
+		srv.udpPool.Put(m)
+		return nil, nil, err
+	}
+	m = m[:n]
+	return m, addr, nil
+}
+
 // WriteMsg implements the ResponseWriter.WriteMsg method.
 func (w *response) WriteMsg(m *Msg) (err error) {
 	if w.closed {
@@ -692,7 +743,10 @@ func (w *response) Write(m []byte) (int, error) {
 
 	switch {
 	case w.udp != nil:
-		return WriteToSessionUDP(w.udp, m, w.udpSession)
+		if u, ok := w.udp.(*net.UDPConn); ok {
+			return WriteToSessionUDP(u, m, w.udpSession)
+		}
+		return w.udp.WriteTo(m, w.pcSession)
 	case w.tcp != nil:
 		if len(m) > MaxMsgSize {
 			return 0, &Error{err: "message too large"}
@@ -725,10 +779,12 @@ func (w *response) RemoteAddr() net.Addr {
 	switch {
 	case w.udpSession != nil:
 		return w.udpSession.RemoteAddr()
+	case w.pcSession != nil:
+		return w.pcSession
 	case w.tcp != nil:
 		return w.tcp.RemoteAddr()
 	default:
-		panic("dns: internal error: udpSession and tcp both nil")
+		panic("dns: internal error: udpSession, pcSession and tcp are all nil")
 	}
 }