класс IPAddr

# File lib/ipaddr.rb, line 470
def initialize(addr = '::', family = Socket::AF_UNSPEC)
  if !addr.kind_of?(String)
    case family
    when Socket::AF_INET, Socket::AF_INET6
      set(addr.to_i, family)
      @mask_addr = (family == Socket::AF_INET) ? IN4MASK : IN6MASK
      return
    when Socket::AF_UNSPEC
      raise AddressFamilyError, "address family must be specified"
    else
      raise AddressFamilyError, "unsupported address family: #{family}"
    end
  end
  prefix, prefixlen = addr.split('/')
  if prefix =~ /\A\[(.*)\]\z/i
    prefix = $1
    family = Socket::AF_INET6
  end
  # It seems AI_NUMERICHOST doesn't do the job.
  #Socket.getaddrinfo(left, nil, Socket::AF_INET6, Socket::SOCK_STREAM, nil,
  #                  Socket::AI_NUMERICHOST)
  @addr = @family = nil
  if family == Socket::AF_UNSPEC || family == Socket::AF_INET
    @addr = in_addr(prefix)
    if @addr
      @family = Socket::AF_INET
    end
  end
  if !@addr && (family == Socket::AF_UNSPEC || family == Socket::AF_INET6)
    @addr = in6_addr(prefix)
    @family = Socket::AF_INET6
  end
  if family != Socket::AF_UNSPEC && @family != family
    raise AddressFamilyError, "address family mismatch"
  end
  if prefixlen
    mask!(prefixlen)
  else
    @mask_addr = (@family == Socket::AF_INET) ? IN4MASK : IN6MASK
  end
end

# File lib/ipaddr.rb, line 105
def IPAddr::new_ntoh(addr)
  return IPAddr.new(IPAddr::ntop(addr))
end

# File lib/ipaddr.rb, line 111
def IPAddr::ntop(addr)
  case addr.size
  when 4
    s = addr.unpack('C4').join('.')
  when 16
    s = IN6FORMAT % addr.unpack('n8')
  else
    raise AddressFamilyError, "unsupported address family"
  end
  return s
end

# File lib/ipaddr.rb, line 414
def mask!(mask)
  if mask.kind_of?(String)
    if mask =~ /\A\d+\z/
      prefixlen = mask.to_i
    else
      m = IPAddr.new(mask)
      if m.family != @family
        raise InvalidPrefixError, "address family is not same"
      end
      @mask_addr = m.to_i
      @addr &= @mask_addr
      return self
    end
  else
    prefixlen = mask
  end
  case @family
  when Socket::AF_INET
    if prefixlen < 0 || prefixlen > 32
      raise InvalidPrefixError, "invalid length"
    end
    masklen = 32 - prefixlen
    @mask_addr = ((IN4MASK >> masklen) << masklen)
  when Socket::AF_INET6
    if prefixlen < 0 || prefixlen > 128
      raise InvalidPrefixError, "invalid length"
    end
    masklen = 128 - prefixlen
    @mask_addr = ((IN6MASK >> masklen) << masklen)
  else
    raise AddressFamilyError, "unsupported address family"
  end
  @addr = ((@addr >> masklen) << masklen)
  return self
end

# File lib/ipaddr.rb, line 393
def set(addr, *family)
  case family[0] ? family[0] : @family
  when Socket::AF_INET
    if addr < 0 || addr > IN4MASK
      raise InvalidAddressError, "invalid address"
    end
  when Socket::AF_INET6
    if addr < 0 || addr > IN6MASK
      raise InvalidAddressError, "invalid address"
    end
  else
    raise AddressFamilyError, "unsupported address family"
  end
  @addr = addr
  if family[0]
    @family = family[0]
  end
  return self
end

# File lib/ipaddr.rb, line 586
def _reverse
  case @family
  when Socket::AF_INET
    return (0..3).map { |i|
      (@addr >> (8 * i)) & 0xff
    }.join('.')
  when Socket::AF_INET6
    return ("%.32x" % @addr).reverse!.gsub!(/.(?!$)/, '\&.')
  else
    raise AddressFamilyError, "unsupported address family"
  end
end

# File lib/ipaddr.rb, line 599
def _to_string(addr)
  case @family
  when Socket::AF_INET
    return (0..3).map { |i|
      (addr >> (24 - 8 * i)) & 0xff
    }.join('.')
  when Socket::AF_INET6
    return (("%.32x" % addr).gsub!(/.{4}(?!$)/, '\&:'))
  else
    raise AddressFamilyError, "unsupported address family"
  end
end

# File lib/ipaddr.rb, line 575
def addr_mask(addr)
  case @family
  when Socket::AF_INET
    return addr & IN4MASK
  when Socket::AF_INET6
    return addr & IN6MASK
  else
    raise AddressFamilyError, "unsupported address family"
  end
end

# File lib/ipaddr.rb, line 512
def coerce_other(other)
  case other
  when IPAddr
    other
  when String
    self.class.new(other)
  else
    self.class.new(other, @family)
  end
end

# File lib/ipaddr.rb, line 538
def in6_addr(left)
  case left
  when RE_IPV6ADDRLIKE_FULL
    if $2
      addr = in_addr($~[2,4])
      left = $1 + ':'
    else
      addr = 0
    end
    right = ''
  when RE_IPV6ADDRLIKE_COMPRESSED
    if $4
      left.count(':') <= 6 or raise InvalidAddressError, "invalid address"
      addr = in_addr($~[4,4])
      left = $1
      right = $3 + '0:0'
    else
      left.count(':') <= ($1.empty? || $2.empty? ? 8 : 7) or
        raise InvalidAddressError, "invalid address"
      left = $1
      right = $2
      addr = 0
    end
  else
    raise InvalidAddressError, "invalid address"
  end
  l = left.split(':')
  r = right.split(':')
  rest = 8 - l.size - r.size
  if rest < 0
    return nil
  end
  (l + Array.new(rest, '0') + r).inject(0) { |i, s|
    i << 16 | s.hex
  } | addr
end

# File lib/ipaddr.rb, line 523
def in_addr(addr)
  case addr
  when Array
    octets = addr
  else
    m = RE_IPV4ADDRLIKE.match(addr) or return nil
    octets = m.captures
  end
  octets.inject(0) { |i, s|
    (n = s.to_i) < 256 or raise InvalidAddressError, "invalid address"
    s.match(/\A0./) and raise InvalidAddressError, "zero-filled number in IPv4 address is ambiguous"
    i << 8 | n
  }
end