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Mike Mackintosh authoredMike Mackintosh authored
ipv6.rb 22.39 KiB
require 'ipaddress/prefix'
module IPAddress;
#
# =Name
#
# IPAddress::IPv6 - IP version 6 address manipulation library
#
# =Synopsis
#
# require 'ipaddress'
#
# =Description
#
# Class IPAddress::IPv6 is used to handle IPv6 type addresses.
#
# == IPv6 addresses
#
# IPv6 addresses are 128 bits long, in contrast with IPv4 addresses
# which are only 32 bits long. An IPv6 address is generally written as
# eight groups of four hexadecimal digits, each group representing 16
# bits or two octect. For example, the following is a valid IPv6
# address:
#
# 2001:0db8:0000:0000:0008:0800:200c:417a
#
# Letters in an IPv6 address are usually written downcase, as per
# RFC. You can create a new IPv6 object using uppercase letters, but
# they will be converted.
#
# === Compression
#
# Since IPv6 addresses are very long to write, there are some
# semplifications and compressions that you can use to shorten them.
#
# * Leading zeroes: all the leading zeroes within a group can be
# omitted: "0008" would become "8"
#
# * A string of consecutive zeroes can be replaced by the string
# "::". This can be only applied once.
#
# Using compression, the IPv6 address written above can be shorten into
# the following, equivalent, address
#
# 2001:db8::8:800:200c:417a
#
# This short version is often used in human representation.
#
# === Network Mask
#
# As we used to do with IPv4 addresses, an IPv6 address can be written
# using the prefix notation to specify the subnet mask:
#
# 2001:db8::8:800:200c:417a/64
#
# The /64 part means that the first 64 bits of the address are
# representing the network portion, and the last 64 bits are the host
# portion.
#
#
class IPv6
include IPAddress
include Enumerable
include Comparable
#
# Format string to pretty print IPv6 addresses
# IN6FORMAT = ("%.4x:"*8).chop
#
# Creates a new IPv6 address object.
#
# An IPv6 address can be expressed in any of the following forms:
#
# * "2001:0db8:0000:0000:0008:0800:200C:417A": IPv6 address with no compression
# * "2001:db8:0:0:8:800:200C:417A": IPv6 address with leading zeros compression
# * "2001:db8::8:800:200C:417A": IPv6 address with full compression
#
# In all these 3 cases, a new IPv6 address object will be created, using the default
# subnet mask /128
#
# You can also specify the subnet mask as with IPv4 addresses:
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
def initialize(str)
ip, netmask = str.split("/")
if str =~ /:.+\./
raise ArgumentError, "Please use #{self.class}::Mapped for IPv4 mapped addresses"
end
if IPAddress.valid_ipv6?(ip)
@groups = self.class.groups(ip)
@address = IN6FORMAT % @groups
@compressed = compress_address
else
raise ArgumentError, "Invalid IP #{ip.inspect}"
end
@prefix = Prefix128.new(netmask ? netmask : 128)
end # def initialize
#
# Returns the IPv6 address in uncompressed form:
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.address
# #=> "2001:0db8:0000:0000:0008:0800:200c:417a"
#
def address
@address
end
#
# Returns an array with the 16 bits groups in decimal
# format:
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.groups
# #=> [8193, 3512, 0, 0, 8, 2048, 8204, 16762]
#
def groups
@groups
end
#
# Returns an instance of the prefix object
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.prefix
# #=> 64
# def prefix
@prefix
end
#
# Set a new prefix number for the object
#
# This is useful if you want to change the prefix
# to an object created with IPv6::parse_u128 or
# if the object was created using the default prefix
# of 128 bits.
#
# ip6 = IPAddress("2001:db8::8:800:200c:417a")
#
# puts ip6.to_string
# #=> "2001:db8::8:800:200c:417a/128"
#
# ip6.prefix = 64
# puts ip6.to_string
# #=> "2001:db8::8:800:200c:417a/64"
#
def prefix=(num)
@prefix = Prefix128.new(num)
end
#
# Unlike its counterpart IPv6#to_string method, IPv6#to_string_uncompressed
# returns the whole IPv6 address and prefix in an uncompressed form
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.to_string_uncompressed
# #=> "2001:0db8:0000:0000:0008:0800:200c:417a/64"
#
def to_string_uncompressed
"#@address/#@prefix"
end
#
# Returns the IPv6 address in a human readable form,
# using the compressed address.
#
# ip6 = IPAddress "2001:0db8:0000:0000:0008:0800:200c:417a/64"
#
# ip6.to_string
# #=> "2001:db8::8:800:200c:417a/64"
#
def to_string
"#@compressed/#@prefix"
end
#
# Returns the IPv6 address in a human readable form,
# using the compressed address.
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.to_s
# #=> "2001:db8::8:800:200c:417a"
#
def to_s
@compressed
end
#
# Returns a decimal format (unsigned 128 bit) of the
# IPv6 address
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
# # ip6.to_i
# #=> 42540766411282592856906245548098208122
#
def to_i
to_hex.hex
end
alias_method :to_u128, :to_i
#
# True if the IPv6 address is a network
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.network?
# #=> false
#
# ip6 = IPAddress "2001:db8:8:800::/64"
#
# ip6.network?
# #=> true
#
def network?
to_u128 | @prefix.to_u128 == @prefix.to_u128
end
#
# Returns the 16-bits value specified by index
#
# ip = IPAddress("2001:db8::8:800:200c:417a/64")
#
# ip[0]
# #=> 8193
# ip[1]
# #=> 3512
# ip[2]
# #=> 0
# ip[3]
# #=> 0
#
def [](index)
@groups[index]
end
alias_method :group, :[]
#
# Updated the octet specified at index
#
def []=(index, value)
@groups[index] = value
initialize("#{IN6FORMAT % @groups}/#{prefix}")
end
alias_method :group=, :[]=
#
# Returns a Base16 number representing the IPv6
# address
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.to_hex
# #=> "20010db80000000000080800200c417a"
#
def to_hex
hexs.join("")
end
# Returns the address portion of an IPv6 object
# in a network byte order format.
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64" #
# ip6.data
# #=> " \001\r\270\000\000\000\000\000\b\b\000 \fAz"
#
# It is usually used to include an IP address
# in a data packet to be sent over a socket
#
# a = Socket.open(params) # socket details here
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
# binary_data = ["Address: "].pack("a*") + ip.data
#
# # Send binary data
# a.puts binary_data
#
def data
@groups.pack("n8")
end
#
# Returns an array of the 16 bits groups in hexdecimal
# format:
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.hexs
# #=> ["2001", "0db8", "0000", "0000", "0008", "0800", "200c", "417a"]
#
# Not to be confused with the similar IPv6#to_hex method.
#
def hexs
@address.split(":")
end
#
# Returns the IPv6 address in a DNS reverse lookup
# string, as per RFC3172 and RFC2874.
#
# ip6 = IPAddress "3ffe:505:2::f"
#
# ip6.reverse
# #=> "f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.0.5.0.5.0.e.f.f.3.ip6.arpa"
#
def reverse
to_hex.reverse.gsub(/./){|c| c+"."} + "ip6.arpa"
end
alias_method :arpa, :reverse
#
# Returns the network number in Unsigned 128bits format
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.network_u128
# #=> 42540766411282592856903984951653826560
#
def network_u128
to_u128 & @prefix.to_u128
end
#
# Returns the broadcast address in Unsigned 128bits format
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.broadcast_u128
# #=> 42540766411282592875350729025363378175
#
# Please note that there is no Broadcast concept in IPv6
# addresses as in IPv4 addresses, and this method is just
# an helper to other functions. #
def broadcast_u128
network_u128 + size - 1
end
#
# Returns the number of IP addresses included
# in the network. It also counts the network
# address and the broadcast address.
#
# ip6 = IPAddress("2001:db8::8:800:200c:417a/64")
#
# ip6.size
# #=> 18446744073709551616
#
def size
2 ** @prefix.host_prefix
end
#
# Checks whether a subnet includes the given IP address.
#
# Example:
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
# addr = IPAddress "2001:db8::8:800:200c:1/128"
#
# ip6.include? addr
# #=> true
#
# ip6.include? IPAddress("2001:db8:1::8:800:200c:417a/76")
# #=> false
#
def include?(oth)
@prefix <= oth.prefix and network_u128 == self.class.new(oth.address+"/#@prefix").network_u128
end
#
# Compressed form of the IPv6 address
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.compressed
# #=> "2001:db8::8:800:200c:417a"
#
def compressed
@compressed
end
#
# Returns true if the address is an unspecified address
#
# See IPAddress::IPv6::Unspecified for more information
#
def unspecified?
@prefix == 128 and @compressed == "::"
end
#
# Returns true if the address is a loopback address
#
# See IPAddress::IPv6::Loopback for more information
#
def loopback?
@prefix == 128 and @compressed == "::1"
end
#
# Returns true if the address is a mapped address
# # See IPAddress::IPv6::Mapped for more information
#
def mapped?
to_u128 >> 32 == 0xffff
end
#
# Iterates over all the IP addresses for the given
# network (or IP address).
#
# The object yielded is a new IPv6 object created
# from the iteration.
#
# ip6 = IPAddress("2001:db8::4/125")
#
# ip6.each do |i|
# p i.compressed
# end
# #=> "2001:db8::"
# #=> "2001:db8::1"
# #=> "2001:db8::2"
# #=> "2001:db8::3"
# #=> "2001:db8::4"
# #=> "2001:db8::5"
# #=> "2001:db8::6"
# #=> "2001:db8::7"
#
# WARNING: if the host portion is very large, this method
# can be very slow and possibly hang your system!
#
def each
(network_u128..broadcast_u128).each do |i|
yield self.class.parse_u128(i, @prefix)
end
end
#
# Spaceship operator to compare IPv6 objects
#
# Comparing IPv6 addresses is useful to ordinate
# them into lists that match our intuitive
# perception of ordered IP addresses.
#
# The first comparison criteria is the u128 value.
# For example, 2001:db8:1::1 will be considered
# to be less than 2001:db8:2::1, because, in a ordered list,
# we expect 2001:db8:1::1 to come before 2001:db8:2::1.
#
# The second criteria, in case two IPv6 objects
# have identical addresses, is the prefix. An higher
# prefix will be considered greater than a lower
# prefix. This is because we expect to see
# 2001:db8:1::1/64 come before 2001:db8:1::1/65
#
# Example:
#
# ip1 = IPAddress "2001:db8:1::1/64"
# ip2 = IPAddress "2001:db8:2::1/64"
# ip3 = IPAddress "2001:db8:1::1/65"
#
# ip1 < ip2
# #=> true
# ip1 < ip3
# #=> false
#
# [ip1,ip2,ip3].sort.map{|i| i.to_string}
# #=> ["2001:db8:1::1/64","2001:db8:1::1/65","2001:db8:2::1/64"]
#
def <=>(oth)
return prefix <=> oth.prefix if to_u128 == oth.to_u128 to_u128 <=> oth.to_u128
end
#
# Returns the address portion of an IP in binary format,
# as a string containing a sequence of 0 and 1
#
# ip6 = IPAddress("2001:db8::8:800:200c:417a")
#
# ip6.bits
# #=> "0010000000000001000011011011100000 [...] "
#
def bits
data.unpack("B*").first
end
#
# Expands an IPv6 address in the canocical form
#
# IPAddress::IPv6.expand "2001:0DB8:0:CD30::"
# #=> "2001:0DB8:0000:CD30:0000:0000:0000:0000"
#
def self.expand(str)
self.new(str).address
end
#
# Compress an IPv6 address in its compressed form
#
# IPAddress::IPv6.compress "2001:0DB8:0000:CD30:0000:0000:0000:0000"
# #=> "2001:db8:0:cd30::"
#
def self.compress(str)
self.new(str).compressed
end
#
# Literal version of the IPv6 address
#
# ip6 = IPAddress "2001:db8::8:800:200c:417a/64"
#
# ip6.literal
# #=> "2001-0db8-0000-0000-0008-0800-200c-417a.ipv6-literal.net"
#
def literal
@address.gsub(":","-") + ".ipv6-literal.net"
end
#
# Returns a new IPv6 object with the network number
# for the given IP.
#
# ip = IPAddress "2001:db8:1:1:1:1:1:1/32"
#
# ip.network.to_string
# #=> "2001:db8::/32"
#
def network
self.class.parse_u128(network_u128, @prefix)
end
#
# Extract 16 bits groups from a string
#
def self.groups(str)
l, r = if str =~ /^(.*)::(.*)$/
[$1,$2].map {|i| i.split ":"}
else
[str.split(":"),[]]
end (l + Array.new(8-l.size-r.size, '0') + r).map {|i| i.hex}
end
#
# Creates a new IPv6 object from binary data,
# like the one you get from a network stream.
#
# For example, on a network stream the IP
#
# "2001:db8::8:800:200c:417a"
#
# is represented with the binary data
#
# " \001\r\270\000\000\000\000\000\b\b\000 \fAz"
#
# With that data you can create a new IPv6 object:
#
# ip6 = IPAddress::IPv6::parse_data " \001\r\270\000\000\000\000\000\b\b\000 \fAz"
# ip6.prefix = 64
#
# ip6.to_s
# #=> "2001:db8::8:800:200c:417a/64"
#
def self.parse_data(str)
self.new(IN6FORMAT % str.unpack("n8"))
end
#
# Creates a new IPv6 object from an
# unsigned 128 bits integer.
#
# ip6 = IPAddress::IPv6::parse_u128(42540766411282592856906245548098208122)
# ip6.prefix = 64
#
# ip6.to_string
# #=> "2001:db8::8:800:200c:417a/64"
#
# The +prefix+ parameter is optional:
#
# ip6 = IPAddress::IPv6::parse_u128(42540766411282592856906245548098208122, 64)
#
# ip6.to_string
# #=> "2001:db8::8:800:200c:417a/64"
#
def self.parse_u128(u128, prefix=128)
str = IN6FORMAT % (0..7).map{|i| (u128>>(112-16*i))&0xffff}
self.new(str + "/#{prefix}")
end
#
# Creates a new IPv6 object from a number expressed in
# hexdecimal format:
#
# ip6 = IPAddress::IPv6::parse_hex("20010db80000000000080800200c417a")
# ip6.prefix = 64
#
# ip6.to_string
# #=> "2001:db8::8:800:200c:417a/64"
#
# The +prefix+ parameter is optional:
#
# ip6 = IPAddress::IPv6::parse_hex("20010db80000000000080800200c417a", 64)
#
# ip6.to_string
# #=> "2001:db8::8:800:200c:417a/64"
#
def self.parse_hex(hex, prefix=128)
self.parse_u128(hex.hex, prefix)
end
private
def compress_address
str = @groups.map{|i| i.to_s 16}.join ":"
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,}/, '::')
end
end # class IPv6
#
# The address with all zero bits is called the +unspecified+ address
# (corresponding to 0.0.0.0 in IPv4). It should be something like this:
#
# 0000:0000:0000:0000:0000:0000:0000:0000
#
# but, with the use of compression, it is usually written as just two
# colons:
#
# ::
#
# or, specifying the netmask:
#
# ::/128
#
# With IPAddress, create a new unspecified IPv6 address using its own
# subclass:
#
# ip = IPAddress::IPv6::Unspecified.new
#
# ip.to_s
# #=> => "::/128"
#
# You can easily check if an IPv6 object is an unspecified address by
# using the IPv6#unspecified? method
#
# ip.unspecified?
# #=> true
#
# An unspecified IPv6 address can also be created with the wrapper
# method, like we've seen before
#
# ip = IPAddress "::"
#
# ip.unspecified?
# #=> true
#
# This address must never be assigned to an interface and is to be used
# only in software before the application has learned its host's source
# address appropriate for a pending connection. Routers must not forward
# packets with the unspecified address.
#
class IPAddress::IPv6::Unspecified < IPAddress::IPv6
#
# Creates a new IPv6 unspecified address
#
# ip = IPAddress::IPv6::Unspecified.new
#
# ip.to_s
# #=> => "::/128"
# def initialize
@address = ("0000:"*8).chop
@groups = Array.new(8,0)
@prefix = Prefix128.new(128)
@compressed = compress_address
end
end # class IPv6::Unspecified
#
# The loopback address is a unicast localhost address. If an
# application in a host sends packets to this address, the IPv6 stack
# will loop these packets back on the same virtual interface.
#
# Loopback addresses are expressed in the following form:
#
# ::1
#
# or, with their appropriate prefix,
#
# ::1/128
#
# As for the unspecified addresses, IPv6 loopbacks can be created with
# IPAddress calling their own class:
#
# ip = IPAddress::IPv6::Loopback.new
#
# ip.to_string
# #=> "::1/128"
#
# or by using the wrapper:
#
# ip = IPAddress "::1"
#
# ip.to_string
# #=> "::1/128"
#
# Checking if an address is loopback is easy with the IPv6#loopback?
# method:
#
# ip.loopback?
# #=> true
#
# The IPv6 loopback address corresponds to 127.0.0.1 in IPv4.
#
class IPAddress::IPv6::Loopback < IPAddress::IPv6
#
# Creates a new IPv6 unspecified address
#
# ip = IPAddress::IPv6::Loopback.new
#
# ip.to_string
# #=> "::1/128"
#
def initialize
@address = ("0000:"*7)+"0001"
@groups = Array.new(7,0).push(1)
@prefix = Prefix128.new(128)
@compressed = compress_address
end
end # class IPv6::Loopback
#
# It is usually identified as a IPv4 mapped IPv6 address, a particular
# IPv6 address which aids the transition from IPv4 to IPv6. The
# structure of the address is
#
# ::ffff:w.y.x.z
#
# where w.x.y.z is a normal IPv4 address. For example, the following is
# a mapped IPv6 address: #
# ::ffff:192.168.100.1
#
# IPAddress is very powerful in handling mapped IPv6 addresses, as the
# IPv4 portion is stored internally as a normal IPv4 object. Let's have
# a look at some examples. To create a new mapped address, just use the
# class builder itself
#
# ip6 = IPAddress::IPv6::Mapped.new "::ffff:172.16.10.1/128"
#
# or just use the wrapper method
#
# ip6 = IPAddress "::ffff:172.16.10.1/128"
#
# Let's check it's really a mapped address:
#
# ip6.mapped?
# #=> true
#
# ip6.to_string
# #=> "::FFFF:172.16.10.1/128"
#
# Now with the +ipv4+ attribute, we can easily access the IPv4 portion
# of the mapped IPv6 address:
#
# ip6.ipv4.address
# #=> "172.16.10.1"
#
# Internally, the IPv4 address is stored as two 16 bits
# groups. Therefore all the usual methods for an IPv6 address are
# working perfectly fine:
#
# ip6.to_hex
# #=> "00000000000000000000ffffac100a01"
#
# ip6.address
# #=> "0000:0000:0000:0000:0000:ffff:ac10:0a01"
#
# A mapped IPv6 can also be created just by specify the address in the
# following format:
#
# ip6 = IPAddress "::172.16.10.1"
#
# That is, two colons and the IPv4 address. However, as by RFC, the ffff
# group will be automatically added at the beginning
#
# ip6.to_string
# => "::ffff:172.16.10.1/128"
#
# making it a mapped IPv6 compatible address.
#
class IPAddress::IPv6::Mapped < IPAddress::IPv6
# Access the internal IPv4 address
attr_reader :ipv4
#
# Creates a new IPv6 IPv4-mapped address
#
# ip6 = IPAddress::IPv6::Mapped.new "::ffff:172.16.10.1/128"
#
# ipv6.ipv4.class
# #=> IPAddress::IPv4
#
# An IPv6 IPv4-mapped address can also be created using the
# IPv6 only format of the address:
#
# ip6 = IPAddress::IPv6::Mapped.new "::0d01:4403"
#
# ip6.to_string # #=> "::ffff:13.1.68.3"
#
def initialize(str)
string, netmask = str.split("/")
if string =~ /\./ # IPv4 in dotted decimal form
@ipv4 = IPAddress::IPv4.extract(string)
else # IPv4 in hex form
groups = IPAddress::IPv6.groups(string)
@ipv4 = IPAddress::IPv4.parse_u32((groups[-2]<< 16)+groups[-1])
end
super("::ffff:#{@ipv4.to_ipv6}/#{netmask}")
end
#
# Similar to IPv6#to_s, but prints out the IPv4 address
# in dotted decimal format
#
# ip6 = IPAddress "::ffff:172.16.10.1/128"
#
# ip6.to_s
# #=> "::ffff:172.16.10.1"
#
def to_s
"::ffff:#{@ipv4.address}"
end
#
# Similar to IPv6#to_string, but prints out the IPv4 address
# in dotted decimal format
#
#
# ip6 = IPAddress "::ffff:172.16.10.1/128"
#
# ip6.to_string
# #=> "::ffff:172.16.10.1/128"
#
def to_string
"::ffff:#{@ipv4.address}/#@prefix"
end
#
# Checks if the IPv6 address is IPv4 mapped
#
# ip6 = IPAddress "::ffff:172.16.10.1/128"
#
# ip6.mapped?
# #=> true
#
def mapped?
true
end
end # class IPv6::Mapped
end # module IPAddress