Source Code for Module dns.e164

  1  # Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license 
  2   
  3  # Copyright (C) 2006-2017 Nominum, Inc. 
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 17   
 18  """DNS E.164 helpers.""" 
 19   
 20  import dns.exception 
 21  import dns.name 
 22  import dns.resolver 
 23  from ._compat import string_types, maybe_decode 
 24   
 25  #: The public E.164 domain. 
 26  public_enum_domain = dns.name.from_text('e164.arpa.') 
 27   
 28   
 29 -def from_e164(text, origin=public_enum_domain): 
 30      """Convert an E.164 number in textual form into a Name object whose 
 31      value is the ENUM domain name for that number. 
 32   
 33      Non-digits in the text are ignored, i.e. "16505551212", 
 34      "+1.650.555.1212" and "1 (650) 555-1212" are all the same. 
 35   
 36      *text*, a ``text``, is an E.164 number in textual form. 
 37   
 38      *origin*, a ``dns.name.Name``, the domain in which the number 
 39      should be constructed.  The default is ``e164.arpa.``. 
 40   
 41      Returns a ``dns.name.Name``. 
 42      """ 
 43   
 44      parts = [d for d in text if d.isdigit()] 
 45      parts.reverse() 
 46      return dns.name.from_text('.'.join(parts), origin=origin) 
 47   
 48   
 49 -def to_e164(name, origin=public_enum_domain, want_plus_prefix=True): 
 50      """Convert an ENUM domain name into an E.164 number. 
 51   
 52      Note that dnspython does not have any information about preferred 
 53      number formats within national numbering plans, so all numbers are 
 54      emitted as a simple string of digits, prefixed by a '+' (unless 
 55      *want_plus_prefix* is ``False``). 
 56   
 57      *name* is a ``dns.name.Name``, the ENUM domain name. 
 58   
 59      *origin* is a ``dns.name.Name``, a domain containing the ENUM 
 60      domain name.  The name is relativized to this domain before being 
 61      converted to text.  If ``None``, no relativization is done. 
 62   
 63      *want_plus_prefix* is a ``bool``.  If True, add a '+' to the beginning of 
 64      the returned number. 
 65   
 66      Returns a ``text``. 
 67   
 68      """ 
 69      if origin is not None: 
 70          name = name.relativize(origin) 
 71      dlabels = [d for d in name.labels if d.isdigit() and len(d) == 1] 
 72      if len(dlabels) != len(name.labels): 
 73          raise dns.exception.SyntaxError('non-digit labels in ENUM domain name') 
 74      dlabels.reverse() 
 75      text = b''.join(dlabels) 
 76      if want_plus_prefix: 
 77          text = b'+' + text 
 78      return maybe_decode(text) 
 79   
 80   
 81 -def query(number, domains, resolver=None): 
 82      """Look for NAPTR RRs for the specified number in the specified domains. 
 83   
 84      e.g. lookup('16505551212', ['e164.dnspython.org.', 'e164.arpa.']) 
 85   
 86      *number*, a ``text`` is the number to look for. 
 87   
 88      *domains* is an iterable containing ``dns.name.Name`` values. 
 89   
 90      *resolver*, a ``dns.resolver.Resolver``, is the resolver to use.  If 
 91      ``None``, the default resolver is used. 
 92      """ 
 93   
 94      if resolver is None: 
 95          resolver = dns.resolver.get_default_resolver() 
 96      e_nx = dns.resolver.NXDOMAIN() 
 97      for domain in domains: 
 98          if isinstance(domain, string_types): 
 99              domain = dns.name.from_text(domain) 
100          qname = dns.e164.from_e164(number, domain) 
101          try: 
102              return resolver.query(qname, 'NAPTR') 
103          except dns.resolver.NXDOMAIN as e: 
104              e_nx += e 
105      raise e_nx 
106