text: # Copyright (C) 2003-2005 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.
  
  """IPv4 helper functions."""
  
  import socket
  import sys
  
  if sys.hexversion < 0x02030000 or sys.platform == 'win32':
      #
      # Some versions of Python 2.2 have an inet_aton which rejects
      # the valid IP address '255.255.255.255'.  It appears this
      # problem is still present on the Win32 platform even in 2.3.
      # We'll work around the problem.
      #
      def inet_aton(text):
          if text == '255.255.255.255':
              return '\xff' * 4
          else:
              return socket.inet_aton(text)
  else:
      inet_aton = socket.inet_aton
  
  inet_ntoa = socket.inet_ntoa
  