Package dns :: Package rdtypes :: Module nsbase |
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# Source Code for Module dns.rdtypes.nsbase

     1  # Copyright (C) 2003-2007, 2009-2011 Nominum, Inc.
     2  #
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     4  # documentation for any purpose with or without fee is hereby granted,
     5  # provided that the above copyright notice and this permission notice
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     8  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
     9  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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    15
    16  """NS-like base classes."""
    17
    18  from io import BytesIO
    19
    20  import dns.exception
    21  import dns.rdata
    22  import dns.name
    23
    24
    25 -class NSBase(dns.rdata.Rdata):
    26
    27      """Base class for rdata that is like an NS record.
    28
    29      @ivar target: the target name of the rdata
    30      @type target: dns.name.Name object"""
    31
    32      __slots__ = ['target']
    33
    34 -    def __init__(self, rdclass, rdtype, target):
    35          super(NSBase, self).__init__(rdclass, rdtype)
    36          self.target = target
    37
    38 -    def to_text(self, origin=None, relativize=True, **kw):
    39          target = self.target.choose_relativity(origin, relativize)
    40          return str(target)
    41
    42      @classmethod
    43 -    def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True):
    44          target = tok.get_name()
    45          target = target.choose_relativity(origin, relativize)
    46          tok.get_eol()
    47          return cls(rdclass, rdtype, target)
    48
    49 -    def to_wire(self, file, compress=None, origin=None):
    50          self.target.to_wire(file, compress, origin)
    51
    52 -    def to_digestable(self, origin=None):
    53          return self.target.to_digestable(origin)
    54
    55      @classmethod
    56 -    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None):
    57          (target, cused) = dns.name.from_wire(wire[: current + rdlen],
    58                                               current)
    59          if cused != rdlen:
    60              raise dns.exception.FormError
    61          if origin is not None:
    62              target = target.relativize(origin)
    63          return cls(rdclass, rdtype, target)
    64
    65 -    def choose_relativity(self, origin=None, relativize=True):
    66          self.target = self.target.choose_relativity(origin, relativize)
    67
    68
    69 -class UncompressedNS(NSBase):
    70
    71      """Base class for rdata that is like an NS record, but whose name
    72      is not compressed when convert to DNS wire format, and whose
    73      digestable form is not downcased."""
    74
    75 -    def to_wire(self, file, compress=None, origin=None):
    76          super(UncompressedNS, self).to_wire(file, None, origin)
    77
    78 -    def to_digestable(self, origin=None):
    79          f = BytesIO()
    80          self.to_wire(f, None, origin)
    81          return f.getvalue()
    82