code: def _read_opt_pad(self, code, *, desc):
          
          _type = self._read_opt_type(code)
  
          if code == 0:
              opt = dict(
                  desc=desc,
                  type=_type,
                  length=1,
              )
          elif code == 1:
              _size = self._read_unpack(1)
              _padn = self._read_fileng(_size)
  
              opt = dict(
                  desc=desc,
                  type=_type,
                  length=_size + 2,
                  padding=_padn,
              )
          else:
              raise ProtocolError(f'{self.alias}: [Optno {code}] invalid format')
  
          return opt
docs: Read HOPOPT padding options.
  
          Structure of HOPOPT padding options [RFC 8200]:
              * Pad1 Option:
                  +-+-+-+-+-+-+-+-+
                  |       0       |
                  +-+-+-+-+-+-+-+-+
  
                  Octets      Bits        Name                    Description
                    0           0     hopopt.pad.type         Option Type
                    0           0     hopopt.pad.type.value   Option Number
                    0           0     hopopt.pad.type.action  Action (00)
                    0           2     hopopt.pad.type.change  Change Flag (0)
  
              * PadN Option:
                  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
                  |       1       |  Opt Data Len |  Option Data
                  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
  
                  Octets      Bits        Name                    Description
                    0           0     hopopt.pad.type         Option Type
                    0           0     hopopt.pad.type.value   Option Number
                    0           0     hopopt.pad.type.action  Action (00)
                    0           2     hopopt.pad.type.change  Change Flag (0)
                    1           8     hopopt.opt.length       Length of Option Data
                    2          16     hopopt.pad.padding      Padding