old_contents: # Copyright (C) 2005 Nominum, Inc.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose with or without fee is hereby granted,
  # provided that the above copyright notice and this permission notice
  # appear in all copies.
  #
  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  """DNS Reverse Map Names."""
  
  import dns.name
  import dns.ipv6
  import dns.ipv4
  
  def from_text(text):
      """Convert an IPv4 or IPv6 address in textual form into a Name object whose
      value is the reverse-map domain name of the address.
      @param text: an IPv4 or IPv6 address in textual form (e.g. '127.0.0.1',
      '::1')
      @type text: str
      @rtype: dns.name.Name object
      """
      
      try:
          parts = list(dns.ipv6.inet_aton(text).encode('hex_codec'))
          suffix = 'ip6.arpa.'
      except:
          parts = ['%d' % ord(byte) for byte in dns.ipv4.inet_aton(text)]
          suffix = 'in-addr.arpa.'
      parts.reverse()
      parts.append(suffix)
      return dns.name.from_text('.'.join(parts))
  
new_contents: # Copyright (C) 2005 Nominum, Inc.
  #
  # Permission to use, copy, modify, and distribute this software and its
  # documentation for any purpose with or without fee is hereby granted,
  # provided that the above copyright notice and this permission notice
  # appear in all copies.
  #
  # THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
  # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
  # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  
  """DNS Reverse Map Names.
  
  @var ipv4_reverse_domain: The DNS IPv4 reverse-map domain, in-addr.arpa.
  @type ipv4_reverse_domain: dns.name.Name object
  @var ipv6_reverse_domain: The DNS IPv6 reverse-map domain, ip6.arpa.
  @type ipv6_reverse_domain: dns.name.Name object
  """
  
  import dns.name
  import dns.ipv6
  import dns.ipv4
  
  ipv4_reverse_domain = dns.name.from_text('in-addr.arpa.')
  ipv6_reverse_domain = dns.name.from_text('ip6.arpa.')
  
  def from_address(text):
      """Convert an IPv4 or IPv6 address in textual form into a Name object whose
      value is the reverse-map domain name of the address.
      @param text: an IPv4 or IPv6 address in textual form (e.g. '127.0.0.1',
      '::1')
      @type text: str
      @rtype: dns.name.Name object
      """
      try:
          parts = list(dns.ipv6.inet_aton(text).encode('hex_codec'))
          origin = ipv6_reverse_domain
      except:
          parts = ['%d' % ord(byte) for byte in dns.ipv4.inet_aton(text)]
          origin = ipv4_reverse_domain
      parts.reverse()
      return dns.name.from_text('.'.join(parts), origin=origin)
  
  def to_address(name):
      """Convert a reverse map domain name into textual address form.
      @param name: an IPv4 or IPv6 address in reverse-map form.
      @type name: dns.name.Name object
      @rtype: str
      """
      if name.is_subdomain(ipv4_reverse_domain):
          name = name.relativize(ipv4_reverse_domain)
          labels = list(name.labels)
          labels.reverse()
          text = '.'.join(labels)
          # run through inet_aton() to check syntax and make pretty.
          return dns.ipv4.inet_ntoa(dns.ipv4.inet_aton(text))
      elif name.is_subdomain(ipv6_reverse_domain):
          name = name.relativize(ipv6_reverse_domain)
          labels = list(name.labels)
          labels.reverse()
          parts = []
          i = 0
          l = len(labels)
          while i < l:
              parts.append(''.join(labels[i:i+4]))
              i += 4
          text = ':'.join(parts)
          # run through inet_aton() to check syntax and make pretty.
          return dns.ipv6.inet_ntoa(dns.ipv6.inet_aton(text))
      else:
          raise dns.exception.SyntaxError, 'unknown reverse-map address family'
  
subject: rename from_text() to from_address(); add to_address()