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

     1  # Copyright (C) 2006, 2007, 2009, 2011 Nominum, Inc.
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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
    23  import dns.exception
    24  import dns.name
    25  import dns.resolver
    26  from ._compat import string_types
    27
    28  public_enum_domain = dns.name.from_text('e164.arpa.')
    29
    30
    31 -def from_e164(text, origin=public_enum_domain):
    32      """Convert an E.164 number in textual form into a Name object whose
    33      value is the ENUM domain name for that number.
    34      @param text: an E.164 number in textual form.
    35      @type text: str
    36      @param origin: The domain in which the number should be constructed.
    37      The default is e164.arpa.
    38      @type origin: dns.name.Name object or None
    39      @rtype: dns.name.Name object
    40      """
    41      parts = [d for d in text if d.isdigit()]
    42      parts.reverse()
    43      return dns.name.from_text('.'.join(parts), origin=origin)
    44
    45
    46 -def to_e164(name, origin=public_enum_domain, want_plus_prefix=True):
    47      """Convert an ENUM domain name into an E.164 number.
    48      @param name: the ENUM domain name.
    49      @type name: dns.name.Name object.
    50      @param origin: A domain containing the ENUM domain name.  The
    51      name is relativized to this domain before being converted to text.
    52      @type origin: dns.name.Name object or None
    53      @param want_plus_prefix: if True, add a '+' to the beginning of the
    54      returned number.
    55      @rtype: str
    56      """
    57      if origin is not None:
    58          name = name.relativize(origin)
    59      dlabels = [d for d in name.labels if d.isdigit() and len(d) == 1]
    60      if len(dlabels) != len(name.labels):
    61          raise dns.exception.SyntaxError('non-digit labels in ENUM domain name')
    62      dlabels.reverse()
    63      text = b''.join(dlabels)
    64      if want_plus_prefix:
    65          text = b'+' + text
    66      return text
    67
    68
    69 -def query(number, domains, resolver=None):
    70      """Look for NAPTR RRs for the specified number in the specified domains.
    71
    72      e.g. lookup('16505551212', ['e164.dnspython.org.', 'e164.arpa.'])
    73      """
    74      if resolver is None:
    75          resolver = dns.resolver.get_default_resolver()
    76      e_nx = dns.resolver.NXDOMAIN()
    77      for domain in domains:
    78          if isinstance(domain, string_types):
    79              domain = dns.name.from_text(domain)
    80          qname = dns.e164.from_e164(number, domain)
    81          try:
    82              return resolver.query(qname, 'NAPTR')
    83          except dns.resolver.NXDOMAIN as e:
    84              e_nx += e
    85      raise e_nx
    86