# class IPAddr

`IPAddr` provides a set of methods to manipulate an IP address. Both IPv4 and IPv6 are supported.

## Example¶ ↑

    require 'ipaddr'

    ipaddr1 = IPAddr.new "3ffe:505:2::1"

    p ipaddr1                   #=> #<IPAddr: IPv6:3ffe:0505:0002:0000:0000:0000:0000:0001/ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff>

    p ipaddr1.to_s              #=> "3ffe:505:2::1"

    ipaddr2 = ipaddr1.mask(48)  #=> #<IPAddr: IPv6:3ffe:0505:0002:0000:0000:0000:0000:0000/ffff:ffff:ffff:0000:0000:0000:0000:0000>

    p ipaddr2.to_s              #=> "3ffe:505:2::"

    ipaddr3 = IPAddr.new "192.168.2.0/24"

    p ipaddr3                   #=> #<IPAddr: IPv4:192.168.2.0/255.255.255.0>

### Constants

IN4MASK

  32 bit mask for IPv4

IN6FORMAT

  Format string for IPv6

IN6MASK

  128 bit mask for IPv6

RE_IPV4ADDRLIKE

  `Regexp` internally used for parsing IPv4 address.

RE_IPV6ADDRLIKE_COMPRESSED

  `Regexp` internally used for parsing IPv6 address.

RE_IPV6ADDRLIKE_FULL

  `Regexp` internally used for parsing IPv6 address.

VERSION

### Attributes

family[R]

Returns the address family of this IP address.

### Public Class Methods

new(addr = '::', family = Socket::AF_UNSPEC) click to toggle source

Creates a new ipaddr object either from a human readable IP address representation in string, or from a packed `in_addr` value followed by an address family.

In the former case, the following are the valid formats that will be recognized: “address”, “address/prefixlen” and “address/mask”, where IPv6 address may be enclosed in square brackets (‘[’ and ‘]’). If a prefixlen or a mask is specified, it returns a masked IP address. Although the address family is determined automatically from a specified string, you can specify one explicitly by the optional second argument.

Otherwise an IP address is generated from a packed `in_addr` value and an address family.

The `IPAddr` class defines many methods and operators, and some of those, such as &, |, include? and ==, accept a string, or a packed `in_addr` value instead of an `IPAddr` object.

    # File lib/ipaddr.rb, line 593
    def initialize(addr = '::', family = Socket::AF_UNSPEC)
      @mask_addr = nil
      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('/', 2)
      if prefix =~ /\A\[(.*)\]\z/i
        prefix = $1
        family = Socket::AF_INET6
      end
      if prefix =~ /\A(.*)(%\w+)\z/
        prefix = $1
        zone_id = $2
        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
      @zone_id = zone_id
      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

new_ntoh(addr) click to toggle source

Creates a new ipaddr containing the given network byte ordered string form of an IP address.

    # File lib/ipaddr.rb, line 107
    def self.new_ntoh(addr)
      return new(ntop(addr))
    end

ntop(addr) click to toggle source

Convert a network byte ordered string form of an IP address into human readable form.

    # File lib/ipaddr.rb, line 113
    def self.ntop(addr)
      case addr.size
      when 4
        addr.unpack('C4').join('.')
      when 16
        IN6FORMAT % addr.unpack('n8')
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

### Public Instance Methods

&(other) click to toggle source

Returns a new ipaddr built by bitwise AND.

    # File lib/ipaddr.rb, line 125
    def &(other)
      return self.clone.set(@addr & coerce_other(other).to_i)
    end

<<(num) click to toggle source

Returns a new ipaddr built by bitwise left shift.

    # File lib/ipaddr.rb, line 140
    def <<(num)
      return self.clone.set(addr_mask(@addr << num))
    end

<=>(other) click to toggle source

Compares the ipaddr with another.

    # File lib/ipaddr.rb, line 386
    def <=>(other)
      other = coerce_other(other)
    rescue
      nil
    else
      @addr <=> other.to_i if other.family == @family
    end

==(other) click to toggle source

Returns true if two ipaddrs are equal.

    # File lib/ipaddr.rb, line 150
    def ==(other)
      other = coerce_other(other)
    rescue
      false
    else
      @family == other.family && @addr == other.to_i
    end

===(other)
Alias for: include?
>>(num) click to toggle source

Returns a new ipaddr built by bitwise right-shift.

    # File lib/ipaddr.rb, line 135
    def >>(num)
      return self.clone.set(@addr >> num)
    end

eql?(other) click to toggle source

Checks equality used by `Hash`.

    # File lib/ipaddr.rb, line 396
    def eql?(other)
      return self.class == other.class && self.hash == other.hash && self == other
    end

hash() click to toggle source

Returns a hash value used by `Hash`, `Set`, and `Array` classes

    # File lib/ipaddr.rb, line 401
    def hash
      return ([@addr, @mask_addr, @zone_id].hash << 1) | (ipv4? ? 0 : 1)
    end

hton() click to toggle source

Returns a network byte ordered string form of the IP address.

    # File lib/ipaddr.rb, line 226
    def hton
      case @family
      when Socket::AF_INET
        return [@addr].pack('N')
      when Socket::AF_INET6
        return (0..7).map { |i|
          (@addr >> (112 - 16 * i)) & 0xffff
        }.pack('n8')
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

include?(other) click to toggle source

Returns true if the given ipaddr is in the range.

e.g.:

    require 'ipaddr'
    net1 = IPAddr.new("192.168.2.0/24")
    net2 = IPAddr.new("192.168.2.100")
    net3 = IPAddr.new("192.168.3.0")
    net4 = IPAddr.new("192.168.2.0/16")
    p net1.include?(net2)     #=> true
    p net1.include?(net3)     #=> false
    p net1.include?(net4)     #=> false
    p net4.include?(net1)     #=> true

    # File lib/ipaddr.rb, line 176
    def include?(other)
      other = coerce_other(other)
      return false unless other.family == family
      begin_addr <= other.begin_addr && end_addr >= other.end_addr
    end

Also aliased as: ===
inspect() click to toggle source

Returns a string containing a human-readable representation of the ipaddr. (“#<IPAddr: family:address/mask>”)

    # File lib/ipaddr.rb, line 441
    def inspect
      case @family
      when Socket::AF_INET
        af = "IPv4"
      when Socket::AF_INET6
        af = "IPv6"
        zone_id = @zone_id.to_s
      else
        raise AddressFamilyError, "unsupported address family"
      end
      return sprintf("#<%s: %s:%s%s/%s>", self.class.name,
                     af, _to_string(@addr), zone_id, _to_string(@mask_addr))
    end

ip6_arpa() click to toggle source

Returns a string for DNS reverse lookup compatible with RFC3172.

    # File lib/ipaddr.rb, line 365
    def ip6_arpa
      if !ipv6?
        raise InvalidAddressError, "not an IPv6 address: #{@addr}"
      end
      return _reverse + ".ip6.arpa"
    end

ip6_int() click to toggle source

Returns a string for DNS reverse lookup compatible with RFC1886.

    # File lib/ipaddr.rb, line 373
    def ip6_int
      if !ipv6?
        raise InvalidAddressError, "not an IPv6 address: #{@addr}"
      end
      return _reverse + ".ip6.int"
    end

ipv4?() click to toggle source

Returns true if the ipaddr is an IPv4 address.

    # File lib/ipaddr.rb, line 240
    def ipv4?
      return @family == Socket::AF_INET
    end

ipv4_compat() click to toggle source

Returns a new ipaddr built by converting the native IPv4 address into an IPv4-compatible IPv6 address.

    # File lib/ipaddr.rb, line 333
    def ipv4_compat
      warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
      if !ipv4?
        raise InvalidAddressError, "not an IPv4 address: #{@addr}"
      end
      return self.clone.set(@addr, Socket::AF_INET6)
    end

ipv4_compat?() click to toggle source

Returns true if the ipaddr is an IPv4-compatible IPv6 address.

    # File lib/ipaddr.rb, line 305
    def ipv4_compat?
      warn "IPAddr\##{__callee__} is obsolete", uplevel: 1 if $VERBOSE
      _ipv4_compat?
    end

ipv4_mapped() click to toggle source

Returns a new ipaddr built by converting the native IPv4 address into an IPv4-mapped IPv6 address.

    # File lib/ipaddr.rb, line 322
    def ipv4_mapped
      if !ipv4?
        raise InvalidAddressError, "not an IPv4 address: #{@addr}"
      end
      clone = self.clone.set(@addr | 0xffff00000000, Socket::AF_INET6)
      clone.instance_variable_set(:@mask_addr, @mask_addr | 0xffffffffffffffffffffffff00000000)
      clone
    end

ipv4_mapped?() click to toggle source

Returns true if the ipaddr is an IPv4-mapped IPv6 address.

    # File lib/ipaddr.rb, line 300
    def ipv4_mapped?
      return ipv6? && (@addr >> 32) == 0xffff
    end

ipv6?() click to toggle source

Returns true if the ipaddr is an IPv6 address.

    # File lib/ipaddr.rb, line 245
    def ipv6?
      return @family == Socket::AF_INET6
    end

link_local?() click to toggle source

Returns true if the ipaddr is a link-local address. IPv4 addresses in 169.254.0.0/16 reserved by RFC 3927 and Link-Local IPv6 Unicast Addresses in fe80::/10 reserved by RFC 4291 are considered link-local.

    # File lib/ipaddr.rb, line 288
    def link_local?
      case @family
      when Socket::AF_INET
        @addr & 0xffff0000 == 0xa9fe0000 # 169.254.0.0/16
      when Socket::AF_INET6
        @addr & 0xffc0_0000_0000_0000_0000_0000_0000_0000 == 0xfe80_0000_0000_0000_0000_0000_0000_0000
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

loopback?() click to toggle source

Returns true if the ipaddr is a loopback address.

    # File lib/ipaddr.rb, line 250
    def loopback?
      case @family
      when Socket::AF_INET
        @addr & 0xff000000 == 0x7f000000
      when Socket::AF_INET6
        @addr == 1
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

mask(prefixlen) click to toggle source

Returns a new ipaddr built by masking IP address with the given prefixlen/netmask. (e.g. 8, 64, “255.255.255.0”, etc.)

    # File lib/ipaddr.rb, line 160
    def mask(prefixlen)
      return self.clone.mask!(prefixlen)
    end

native() click to toggle source

Returns a new ipaddr built by converting the IPv6 address into a native IPv4 address. If the IP address is not an IPv4-mapped or IPv4-compatible IPv6 address, returns self.

    # File lib/ipaddr.rb, line 344
    def native
      if !ipv4_mapped? && !_ipv4_compat?
        return self
      end
      return self.clone.set(@addr & IN4MASK, Socket::AF_INET)
    end

netmask() click to toggle source

Returns the netmask in string format e.g. 255.255.0.0

    # File lib/ipaddr.rb, line 456
    def netmask
      _to_string(@mask_addr)
    end

prefix() click to toggle source

Returns the prefix length in bits for the ipaddr.

    # File lib/ipaddr.rb, line 411
    def prefix
      case @family
      when Socket::AF_INET
        n = IN4MASK ^ @mask_addr
        i = 32
      when Socket::AF_INET6
        n = IN6MASK ^ @mask_addr
        i = 128
      else
        raise AddressFamilyError, "unsupported address family"
      end
      while n.positive?
        n >>= 1
        i -= 1
      end
      i
    end

prefix=(prefix) click to toggle source

Sets the prefix length in bits

    # File lib/ipaddr.rb, line 430
    def prefix=(prefix)
      case prefix
      when Integer
        mask!(prefix)
      else
        raise InvalidPrefixError, "prefix must be an integer: #{@addr}"
      end
    end

private?() click to toggle source

Returns true if the ipaddr is a private address. IPv4 addresses in 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 as defined in RFC 1918 and IPv6 Unique Local Addresses in fc00::/7 as defined in RFC 4193 are considered private. Private IPv4 addresses in the IPv4-mapped IPv6 address range are also considered private.

    # File lib/ipaddr.rb, line 266
    def private?
      case @family
      when Socket::AF_INET
        @addr & 0xff000000 == 0x0a000000 ||    # 10.0.0.0/8
          @addr & 0xfff00000 == 0xac100000 ||  # 172.16.0.0/12
          @addr & 0xffff0000 == 0xc0a80000     # 192.168.0.0/16
      when Socket::AF_INET6
        @addr & 0xfe00_0000_0000_0000_0000_0000_0000_0000 == 0xfc00_0000_0000_0000_0000_0000_0000_0000 ||
          (@addr & 0xffff_0000_0000 == 0xffff_0000_0000 && (
            @addr & 0xff000000 == 0x0a000000 ||  # ::ffff:10.0.0.0/8
            @addr & 0xfff00000 == 0xac100000 ||  # ::ffff::172.16.0.0/12
            @addr & 0xffff0000 == 0xc0a80000     # ::ffff::192.168.0.0/16
          ))
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

reverse() click to toggle source

Returns a string for DNS reverse lookup. It returns a string in RFC3172 form for an IPv6 address.

    # File lib/ipaddr.rb, line 353
    def reverse
      case @family
      when Socket::AF_INET
        return _reverse + ".in-addr.arpa"
      when Socket::AF_INET6
        return ip6_arpa
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

succ() click to toggle source

Returns the successor to the ipaddr.

    # File lib/ipaddr.rb, line 381
    def succ
      return self.clone.set(@addr + 1, @family)
    end

to_i() click to toggle source

Returns the integer representation of the ipaddr.

    # File lib/ipaddr.rb, line 184
    def to_i
      return @addr
    end

to_range() click to toggle source

Creates a `Range` object for the network address.

    # File lib/ipaddr.rb, line 406
    def to_range
      self.class.new(begin_addr, @family)..self.class.new(end_addr, @family)
    end

to_s() click to toggle source

Returns a string containing the IP address representation.

    # File lib/ipaddr.rb, line 189
    def to_s
      str = to_string
      return str if ipv4?

      str.gsub!(/\b0{1,3}([\da-f]+)\b/i, '\1')
      loop do
        break if str.sub!(/\A0:0:0:0:0:0:0:0\z/, '::')
        break if str.sub!(/\b0:0:0:0:0:0:0\b/, ':')
        break if str.sub!(/\b0:0:0:0:0:0\b/, ':')
        break if str.sub!(/\b0:0:0:0:0\b/, ':')
        break if str.sub!(/\b0:0:0:0\b/, ':')
        break if str.sub!(/\b0:0:0\b/, ':')
        break if str.sub!(/\b0:0\b/, ':')
        break
      end
      str.sub!(/:{3,}/, '::')

      if /\A::(ffff:)?([\da-f]{1,4}):([\da-f]{1,4})\z/i =~ str
        str = sprintf('::%s%d.%d.%d.%d', $1, $2.hex / 256, $2.hex % 256, $3.hex / 256, $3.hex % 256)
      end

      str
    end

to_string() click to toggle source

Returns a string containing the IP address representation in canonical form.

    # File lib/ipaddr.rb, line 215
    def to_string
      str = _to_string(@addr)

      if @family == Socket::AF_INET6
        str << zone_id.to_s
      end

      return str
    end

zone_id() click to toggle source

Returns the IPv6 zone identifier, if present. Raises `InvalidAddressError` if not an IPv6 address.

    # File lib/ipaddr.rb, line 462
    def zone_id
      if @family == Socket::AF_INET6
        @zone_id
      else
        raise InvalidAddressError, "not an IPv6 address"
      end
    end

zone_id=(zid) click to toggle source

Returns the IPv6 zone identifier, if present. Raises `InvalidAddressError` if not an IPv6 address.

    # File lib/ipaddr.rb, line 472
    def zone_id=(zid)
      if @family == Socket::AF_INET6
        case zid
        when nil, /\A%(\w+)\z/
          @zone_id = zid
        else
          raise InvalidAddressError, "invalid zone identifier for address"
        end
      else
        raise InvalidAddressError, "not an IPv6 address"
      end
    end

|(other) click to toggle source

Returns a new ipaddr built by bitwise OR.

    # File lib/ipaddr.rb, line 130
    def |(other)
      return self.clone.set(@addr | coerce_other(other).to_i)
    end

~() click to toggle source

Returns a new ipaddr built by bitwise negation.

    # File lib/ipaddr.rb, line 145
    def ~
      return self.clone.set(addr_mask(~@addr))
    end

### Protected Instance Methods

begin_addr() click to toggle source

    # File lib/ipaddr.rb, line 487
    def begin_addr
      @addr & @mask_addr
    end

end_addr() click to toggle source

    # File lib/ipaddr.rb, line 491
    def end_addr
      case @family
      when Socket::AF_INET
        @addr | (IN4MASK ^ @mask_addr)
      when Socket::AF_INET6
        @addr | (IN6MASK ^ @mask_addr)
      else
        raise AddressFamilyError, "unsupported address family"
      end
    end

mask!(mask) click to toggle source

`Set` current netmask to given mask.

    # File lib/ipaddr.rb, line 529
    def mask!(mask)
      case mask
      when String
        case mask
        when /\A(0|[1-9]+\d*)\z/
          prefixlen = mask.to_i
        when /\A\d+\z/
          raise InvalidPrefixError, "leading zeros in prefix"
        else
          m = IPAddr.new(mask)
          if m.family != @family
            raise InvalidPrefixError, "address family is not same: #{@addr}"
          end
          @mask_addr = m.to_i
          n = @mask_addr ^ m.instance_variable_get(:@mask_addr)
          unless ((n + 1) & n).zero?
            raise InvalidPrefixError, "invalid mask #{mask}: #{@addr}"
          end
          @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: #{@addr}"
        end
        masklen = 32 - prefixlen
        @mask_addr = ((IN4MASK >> masklen) << masklen)
      when Socket::AF_INET6
        if prefixlen < 0 || prefixlen > 128
          raise InvalidPrefixError, "invalid length: #{@addr}"
        end
        masklen = 128 - prefixlen
        @mask_addr = ((IN6MASK >> masklen) << masklen)
      else
        raise AddressFamilyError, "unsupported address family"
      end
      @addr = ((@addr >> masklen) << masklen)
      return self
    end

set(addr, *family) click to toggle source

`Set` +@addr+, the internal stored ip address, to given `addr`. The parameter `addr` is validated using the first `family` member, which is `Socket::AF_INET` or `Socket::AF_INET6`.

    # File lib/ipaddr.rb, line 505
    def set(addr, *family)
      case family[0] ? family[0] : @family
      when Socket::AF_INET
        if addr < 0 || addr > IN4MASK
          raise InvalidAddressError, "invalid address: #{@addr}"
        end
      when Socket::AF_INET6
        if addr < 0 || addr > IN6MASK
          raise InvalidAddressError, "invalid address: #{@addr}"
        end
      else
        raise AddressFamilyError, "unsupported address family"
      end
      @addr = addr
      if family[0]
        @family = family[0]
        if @family == Socket::AF_INET
          @mask_addr &= IN4MASK
        end
      end
      return self
    end

### Private Instance Methods

_ipv4_compat?() click to toggle source

    # File lib/ipaddr.rb, line 310
    def _ipv4_compat?
      if !ipv6? || (@addr >> 32) != 0
        return false
      end
      a = (@addr & IN4MASK)
      return a != 0 && a != 1
    end

_reverse() click to toggle source

    # File lib/ipaddr.rb, line 716
    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

_to_string(addr) click to toggle source

    # File lib/ipaddr.rb, line 729
    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

addr_mask(addr) click to toggle source

    # File lib/ipaddr.rb, line 705
    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

coerce_other(other) click to toggle source

    # File lib/ipaddr.rb, line 642
    def coerce_other(other)
      case other
      when IPAddr
        other
      when String
        self.class.new(other)
      else
        self.class.new(other, @family)
      end
    end

in6_addr(left) click to toggle source

    # File lib/ipaddr.rb, line 668
    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 $4
          left.count(':') <= 6 or raise InvalidAddressError, "invalid address: #{@addr}"
          addr = in_addr($~[4,4])
          left = $1
          right = $3 + '0:0'
        else
          left.count(':') <= ($1.empty? || $2.empty? ? 8 : 7) or
            raise InvalidAddressError, "invalid address: #{@addr}"
          left = $1
          right = $2
          addr = 0
        end
      else
        raise InvalidAddressError, "invalid address: #{@addr}"
      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

in_addr(addr) click to toggle source

    # File lib/ipaddr.rb, line 653
    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: #{@addr}"
        s.match(/\A0./) and raise InvalidAddressError, "zero-filled number in IPv4 address is ambiguous: #{@addr}"
        i << 8 | n
      }
    end