code: def recv_msg(self):
          '''message receive routine for UDP link'''
          self.pre_message()
          s = self.recv()
          if len(s) > 0:
              if self.first_byte:
                  self.auto_mavlink_version(s)
  
          m = self.mav.parse_char(s)
          if m is not None:
              self.post_message(m)
  
          return f recv_msg(self):
          '''message receive routine for UDP link'''
          self.pre_message()
          s = self.recv()
          if len(s) > 0:
              if self.first_byte:
                  self.auto_mavlink_version(s)
  
          m = self.mav.parse_char(s)
          if m is not None:
              self.post_message(m)
  
          return m
docs: message receive routine for UDP link