Package dns :: Module e164 |
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# Source Code for Module dns.e164

     1  # Copyright (C) 2006, 2007, 2009 Nominum, Inc.
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     5  # provided that the above copyright notice and this permission notice
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     9  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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    15
    16  """DNS E.164 helpers
    17
    18  @var public_enum_domain: The DNS public ENUM domain, e164.arpa.
    19  @type public_enum_domain: dns.name.Name object
    20  """
    21
    22  import dns.exception
    23  import dns.name
    24  import dns.resolver
    25
    26  public_enum_domain = dns.name.from_text('e164.arpa.')
    27
    28 -def from_e164(text, origin=public_enum_domain):
    29      """Convert an E.164 number in textual form into a Name object whose
    30      value is the ENUM domain name for that number.
    31      @param text: an E.164 number in textual form.
    32      @type text: str
    33      @param origin: The domain in which the number should be constructed.
    34      The default is e164.arpa.
    35      @type: dns.name.Name object or None
    36      @rtype: dns.name.Name object
    37      """
    38      parts = [d for d in text if d.isdigit()]
    39      parts.reverse()
    40      return dns.name.from_text('.'.join(parts), origin=origin)
    41
    42 -def to_e164(name, origin=public_enum_domain, want_plus_prefix=True):
    43      """Convert an ENUM domain name into an E.164 number.
    44      @param name: the ENUM domain name.
    45      @type name: dns.name.Name object.
    46      @param origin: A domain containing the ENUM domain name.  The
    47      name is relativized to this domain before being converted to text.
    48      @type: dns.name.Name object or None
    49      @param want_plus_prefix: if True, add a '+' to the beginning of the
    50      returned number.
    51      @rtype: str
    52      """
    53      if not origin is None:
    54          name = name.relativize(origin)
    55      dlabels = [d for d in name.labels if (d.isdigit() and len(d) == 1)]
    56      if len(dlabels) != len(name.labels):
    57          raise dns.exception.SyntaxError('non-digit labels in ENUM domain name')
    58      dlabels.reverse()
    59      text = ''.join(dlabels)
    60      if want_plus_prefix:
    61          text = '+' + text
    62      return text
    63
    64 -def query(number, domains, resolver=None):
    65      """Look for NAPTR RRs for the specified number in the specified domains.
    66
    67      e.g. lookup('16505551212', ['e164.dnspython.org.', 'e164.arpa.'])
    68      """
    69      if resolver is None:
    70          resolver = dns.resolver.get_default_resolver()
    71      for domain in domains:
    72          if isinstance(domain, (str, unicode)):
    73              domain = dns.name.from_text(domain)
    74          qname = dns.e164.from_e164(number, domain)
    75          try:
    76              return resolver.query(qname, 'NAPTR')
    77          except dns.resolver.NXDOMAIN:
    78              pass
    79      raise dns.resolver.NXDOMAIN
    80