Source Code for Module dns.rdtypes.euibase

 1  # Copyright (C) 2015 Red Hat, Inc. 
 2  # Author: Petr Spacek <pspacek@redhat.com> 
 3  # 
 4  # Permission to use, copy, modify, and distribute this software and its 
 5  # documentation for any purpose with or without fee is hereby granted, 
 6  # provided that the above copyright notice and this permission notice 
 7  # appear in all copies. 
 8  # 
 9  # THE SOFTWARE IS PROVIDED 'AS IS' AND RED HAT DISCLAIMS ALL WARRANTIES 
10  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
11  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR 
12  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
13  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
14  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 
15  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
16   
17  import binascii 
18   
19  import dns.rdata 
20  from dns._compat import xrange 
21   
22   
23 -class EUIBase(dns.rdata.Rdata): 
24   
25      """EUIxx record 
26   
27      @ivar fingerprint: xx-bit Extended Unique Identifier (EUI-xx) 
28      @type fingerprint: string 
29      @see: rfc7043.txt""" 
30   
31      __slots__ = ['eui'] 
32      # define these in subclasses 
33      # byte_len = 6  # 0123456789ab (in hex) 
34      # text_len = byte_len * 3 - 1  # 01-23-45-67-89-ab 
35   
36 -    def __init__(self, rdclass, rdtype, eui): 
37          super(EUIBase, self).__init__(rdclass, rdtype) 
38          if len(eui) != self.byte_len: 
39              raise dns.exception.FormError('EUI%s rdata has to have %s bytes' 
40                                            % (self.byte_len * 8, self.byte_len)) 
41          self.eui = eui 
42   
43 -    def to_text(self, origin=None, relativize=True, **kw): 
44          return dns.rdata._hexify(self.eui, chunksize=2).replace(' ', '-') 
45   
46      @classmethod 
47 -    def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True): 
48          text = tok.get_string() 
49          tok.get_eol() 
50          if len(text) != cls.text_len: 
51              raise dns.exception.SyntaxError( 
52                  'Input text must have %s characters' % cls.text_len) 
53          expected_dash_idxs = xrange(2, cls.byte_len * 3 - 1, 3) 
54          for i in expected_dash_idxs: 
55              if text[i] != '-': 
56                  raise dns.exception.SyntaxError('Dash expected at position %s' 
57                                                  % i) 
58          text = text.replace('-', '') 
59          try: 
60              data = binascii.unhexlify(text.encode()) 
61          except (ValueError, TypeError) as ex: 
62              raise dns.exception.SyntaxError('Hex decoding error: %s' % str(ex)) 
63          return cls(rdclass, rdtype, data) 
64   
65 -    def to_wire(self, file, compress=None, origin=None): 
66          file.write(self.eui) 
67   
68      @classmethod 
69 -    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None): 
70          eui = wire[current:current + rdlen].unwrap() 
71          return cls(rdclass, rdtype, eui) 
72