func()

in ntp/responder/server/server.go [136:177]

• 33 lines of code
• 7 McCabe index (conditional complexity)

func (s *Server) startListener(conn *net.UDPConn) {
	s.Checker.IncListeners()
	defer s.Checker.DecListeners()

	// get connection file descriptor
	connFd, err := timestamp.ConnFd(conn)
	if err != nil {
		log.Fatalf("Getting event connection FD: %s", err)
	}

	// Allow reading of kernel timestamps via socket
	if err := timestamp.EnableSWTimestampsRx(connFd); err != nil {
		log.Fatalf("enabling timestamp error: %s", err)
	}

	err = unix.SetNonblock(connFd, false)
	if err != nil {
		log.Fatalf("Failed to set socket to blocking: %s", err)
	}

	buf := make([]byte, timestamp.PayloadSizeBytes)
	oob := make([]byte, timestamp.ControlSizeBytes)

	for {
		request := new(ntp.Packet)
		// read kernel timestamp from incoming packet
		bbuf, clisa, rxTS, err := timestamp.ReadPacketWithRXTimestampBuf(connFd, buf, oob)
		if err != nil {
			log.Errorf("Failed to read packet on %s: %v", conn.LocalAddr(), err)
			s.Stats.IncReadError()
			continue
		}

		if err := request.UnmarshalBinary(buf[:bbuf]); err != nil {
			log.Errorf("failed to parse ntp packet: %s", err)
			s.Stats.IncReadError()
			continue
		}
		s.Stats.IncRequests()
		s.tasks <- task{connFd: connFd, addr: clisa, received: rxTS, request: request, stats: s.Stats}
	}
}