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   
21   
22 -class EUIBase(dns.rdata.Rdata): 
23   
24      """EUIxx record 
25   
26      @ivar fingerprint: xx-bit Extended Unique Identifier (EUI-xx) 
27      @type fingerprint: string 
28      @see: rfc7043.txt""" 
29   
30      __slots__ = ['eui'] 
31      # define these in subclasses 
32      # byte_len = 6  # 0123456789ab (in hex) 
33      # text_len = byte_len * 3 - 1  # 01-23-45-67-89-ab 
34   
35 -    def __init__(self, rdclass, rdtype, eui): 
36          super(EUIBase, self).__init__(rdclass, rdtype) 
37          if len(eui) != self.byte_len: 
38              raise dns.exception.FormError('EUI%s rdata has to have %s bytes' 
39                                            % (self.byte_len * 8, self.byte_len)) 
40          self.eui = eui 
41   
42 -    def to_text(self, origin=None, relativize=True, **kw): 
43          return dns.rdata._hexify(self.eui, chunksize=2).replace(' ', '-') 
44   
45      @classmethod 
46 -    def from_text(cls, rdclass, rdtype, tok, origin=None, relativize=True): 
47          text = tok.get_string() 
48          tok.get_eol() 
49          if len(text) != cls.text_len: 
50              raise dns.exception.SyntaxError( 
51                  'Input text must have %s characters' % cls.text_len) 
52          expected_dash_idxs = range(2, cls.byte_len * 3 - 1, 3) 
53          for i in expected_dash_idxs: 
54              if text[i] != '-': 
55                  raise dns.exception.SyntaxError('Dash expected at position %s' 
56                                                  % i) 
57          text = text.replace('-', '') 
58          try: 
59              data = binascii.unhexlify(text.encode()) 
60          except (ValueError, TypeError) as ex: 
61              raise dns.exception.SyntaxError('Hex decoding error: %s' % str(ex)) 
62          return cls(rdclass, rdtype, data) 
63   
64 -    def to_wire(self, file, compress=None, origin=None): 
65          file.write(self.eui) 
66   
67      @classmethod 
68 -    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin=None): 
69          eui = wire[current:current + rdlen].unwrap() 
70          return cls(rdclass, rdtype, eui) 
71