Source Code for Module dns.rdtypes.mxbase

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15   
16  """MX-like base classes.""" 
17   
18  import cStringIO 
19  import struct 
20   
21  import dns.exception 
22  import dns.rdata 
23  import dns.name 
24   
25 -class MXBase(dns.rdata.Rdata): 
26      """Base class for rdata that is like an MX record. 
27   
28      @ivar preference: the preference value 
29      @type preference: int 
30      @ivar exchange: the exchange name 
31      @type exchange: dns.name.Name object""" 
32   
33      __slots__ = ['preference', 'exchange'] 
34   
35 -    def __init__(self, rdclass, rdtype, preference, exchange): 
36          super(MXBase, self).__init__(rdclass, rdtype) 
37          self.preference = preference 
38          self.exchange = exchange 
39   
40 -    def to_text(self, origin=None, relativize=True, **kw): 
41          exchange = self.exchange.choose_relativity(origin, relativize) 
42          return '%d %s' % (self.preference, exchange) 
43   
44 -    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True): 
45          preference = tok.get_uint16() 
46          exchange = tok.get_name() 
47          exchange = exchange.choose_relativity(origin, relativize) 
48          tok.get_eol() 
49          return cls(rdclass, rdtype, preference, exchange) 
50   
51      from_text = classmethod(from_text) 
52   
53 -    def to_wire(self, file, compress = None, origin = None): 
54          pref = struct.pack("!H", self.preference) 
55          file.write(pref) 
56          self.exchange.to_wire(file, compress, origin) 
57   
58 -    def to_digestable(self, origin = None): 
59          return struct.pack("!H", self.preference) + \ 
60              self.exchange.to_digestable(origin) 
61   
62 -    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None): 
63          (preference, ) = struct.unpack('!H', wire[current : current + 2]) 
64          current += 2 
65          rdlen -= 2 
66          (exchange, cused) = dns.name.from_wire(wire[: current + rdlen], 
67                                                 current) 
68          if cused != rdlen: 
69              raise dns.exception.FormError 
70          if not origin is None: 
71              exchange = exchange.relativize(origin) 
72          return cls(rdclass, rdtype, preference, exchange) 
73   
74      from_wire = classmethod(from_wire) 
75   
76 -    def choose_relativity(self, origin = None, relativize = True): 
77          self.exchange = self.exchange.choose_relativity(origin, relativize) 
78   
79 -class UncompressedMX(MXBase): 
80      """Base class for rdata that is like an MX record, but whose name 
81      is not compressed when converted to DNS wire format, and whose 
82      digestable form is not downcased.""" 
83   
84 -    def to_wire(self, file, compress = None, origin = None): 
85          super(UncompressedMX, self).to_wire(file, None, origin) 
86   
87 -    def to_digestable(self, origin = None): 
88          f = cStringIO.StringIO() 
89          self.to_wire(f, None, origin) 
90          return f.getvalue() 
91   
92 -class UncompressedDowncasingMX(MXBase): 
93      """Base class for rdata that is like an MX record, but whose name 
94      is not compressed when convert to DNS wire format.""" 
95   
96 -    def to_wire(self, file, compress = None, origin = None): 
97          super(UncompressedDowncasingMX, self).to_wire(file, None, origin) 
98