old_contents: # Copyright (C) 2003-2007, 2009-2011 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 struct
  
  import dns.exception
  
  def inet_ntoa(address):
      if len(address) != 4:
          raise dns.exception.SyntaxError
      return '%u.%u.%u.%u' % (ord(address[0]), ord(address[1]),
                              ord(address[2]), ord(address[3]))
  
  def inet_aton(text):
      parts = text.split('.')
      if len(parts) != 4:
          raise dns.exception.SyntaxError
      try:
          bytes = [int(part) for part in parts]
          return struct.pack('BBBB', *bytes)
      except:
          raise dns.exception.SyntaxError
  
new_contents: # Copyright (C) 2003-2007, 2009-2011 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 struct
  
  import dns.exception
  
  def inet_ntoa(address):
      if len(address) != 4:
          raise dns.exception.SyntaxError
      return '%u.%u.%u.%u' % (ord(address[0]), ord(address[1]),
                              ord(address[2]), ord(address[3]))
  
  def inet_aton(text):
      parts = text.split('.')
      if len(parts) != 4:
          raise dns.exception.SyntaxError
      for part in parts:
          if not part.isdigit():
              raise dns.exception.SyntaxError
          if len(part) > 1 and part[0] == '0':
              # No leading zeros
              raise dns.exception.SyntaxError
      try:
          bytes = [int(part) for part in parts]
          return struct.pack('BBBB', *bytes)
      except:
          raise dns.exception.SyntaxError
  
subject: increase IPv4 parsing strictness yet more