IPAddress::IPv4 - IP version 4 address manipulation library
require 'ipaddress'
Class IPAddress::IPv4 is used to handle IPv4 type addresses.
Extract an IPv4 address from a string and returns a new object
Example:
str = "foobar172.16.10.1barbaz" ip = IPAddress::IPv4::extract str ip.to_s #=> "172.16.10.1"
# File lib/ipaddress/ipv4.rb, line 846 def self.extract(str) self.new REGEXP.match(str).to_s end
Creates a new IPv4 address object.
An IPv4 address can be expressed in any of the following forms:
"10.1.1.1/24": ip address and prefix. This is the common and
suggested way to create an object .
"10.1.1.1/255.255.255.0": ip address and netmask. Although
convenient sometimes, this format is less clear than the previous one.
"10.1.1.1": if the address alone is specified, the prefix will be
set as default 32, also known as the host prefix
Examples:
# These two are the same ip = IPAddress::IPv4.new("10.0.0.1/24") ip = IPAddress("10.0.0.1/24") # These two are the same IPAddress::IPv4.new "10.0.0.1/8" IPAddress::IPv4.new "10.0.0.1/255.0.0.0"
# File lib/ipaddress/ipv4.rb, line 63 def initialize(str) ip, netmask = str.split("/") # Check the ip and remove white space if IPAddress.valid_ipv4?(ip) @address = ip.strip else raise ArgumentError, "Invalid IP #{ip.inspect}" end # Check the netmask if netmask # netmask is defined netmask.strip! if netmask =~ /^\d{1,2}$/ # netmask in cidr format @prefix = Prefix32.new(netmask.to_i) elsif IPAddress.valid_ipv4_netmask?(netmask) # netmask in IP format @prefix = Prefix32.parse_netmask(netmask) else # invalid netmask raise ArgumentError, "Invalid netmask #{netmask}" end else # netmask is nil, reverting to defaul classful mask @prefix = Prefix32.new(32) end # Array formed with the IP octets @octets = @address.split(".").map{|i| i.to_i} # 32 bits interger containing the address @u32 = (@octets[0]<< 24) + (@octets[1]<< 16) + (@octets[2]<< 8) + (@octets[3]) end
Creates a new IPv4 address object by parsing the address in a classful way.
Classful addresses have a fixed netmask based on the class they belong to:
Class A, from 0.0.0.0 to 127.255.255.255
Class B, from 128.0.0.0 to 191.255.255.255
Class C, D and E, from 192.0.0.0 to 255.255.255.254
Example:
ip = IPAddress::IPv4.parse_classful "10.0.0.1" ip.netmask #=> "255.0.0.0" ip.a? #=> true
Note that classes C, D and E will all have a default prefix of /24 or 255.255.255.0
# File lib/ipaddress/ipv4.rb, line 957 def self.parse_classful(ip) if IPAddress.valid_ipv4?(ip) address = ip.strip else raise ArgumentError, "Invalid IP #{ip.inspect}" end prefix = CLASSFUL.find{|h,k| h === ("%.8b" % address.to_i)}.last self.new "#{address}/#{prefix}" end
Creates a new IPv4 object from binary data, like the one you get from a network stream.
For example, on a network stream the IP 172.16.0.1 is represented with the binary "254020n001".
ip = IPAddress::IPv4::parse_data "\254\020\n\001" ip.prefix = 24 ip.to_string #=> "172.16.10.1/24"
# File lib/ipaddress/ipv4.rb, line 830 def self.parse_data(str, prefix=32) self.new(str.unpack("C4").join(".")+"/#{prefix}") end
Creates a new IPv4 object from an unsigned 32bits integer.
ip = IPAddress::IPv4::parse_u32(167772160) ip.prefix = 8 ip.to_string #=> "10.0.0.0/8"
The prefix parameter is optional:
ip = IPAddress::IPv4::parse_u32(167772160, 8) ip.to_string #=> "10.0.0.0/8"
# File lib/ipaddress/ipv4.rb, line 813 def self.parse_u32(u32, prefix=32) self.new([u32].pack("N").unpack("C4").join(".")+"/#{prefix}") end
Summarization (or aggregation) is the process when two or more networks are taken together to check if a supernet, including all and only these networks, exists. If it exists then this supernet is called the summarized (or aggregated) network.
It is very important to understand that summarization can only occur if there are no holes in the aggregated network, or, in other words, if the given networks fill completely the address space of the supernet. So the two rules are:
1) The aggregate network must contain all the IP addresses of the
original networks;
2) The aggregate network must contain only the IP addresses of the
original networks;
A few examples will help clarify the above. Let's consider for instance the following two networks:
ip1 = IPAddress("172.16.10.0/24") ip2 = IPAddress("172.16.11.0/24")
These two networks can be expressed using only one IP address network if we change the prefix. Let Ruby do the work:
IPAddress::IPv4::summarize(ip1,ip2).to_s #=> "172.16.10.0/23"
We note how the network "172.16.10.0/23" includes all the addresses specified in the above networks, and (more important) includes ONLY those addresses.
If we summarized ip1 and ip2 with the following network:
"172.16.0.0/16"
we would have satisfied rule #1 above, but not rule #2. So "172.16.0.0/16" is not an aggregate network for ip1 and ip2.
If it's not possible to compute a single aggregated network for all the original networks, the method returns an array with all the aggregate networks found. For example, the following four networks can be aggregated in a single /22:
ip1 = IPAddress("10.0.0.1/24") ip2 = IPAddress("10.0.1.1/24") ip3 = IPAddress("10.0.2.1/24") ip4 = IPAddress("10.0.3.1/24") IPAddress::IPv4::summarize(ip1,ip2,ip3,ip4).to_string #=> "10.0.0.0/22",
But the following networks can't be summarized in a single network:
ip1 = IPAddress("10.0.1.1/24") ip2 = IPAddress("10.0.2.1/24") ip3 = IPAddress("10.0.3.1/24") ip4 = IPAddress("10.0.4.1/24") IPAddress::IPv4::summarize(ip1,ip2,ip3,ip4).map{|i| i.to_string} #=> ["10.0.1.0/24","10.0.2.0/23","10.0.4.0/24"]
# File lib/ipaddress/ipv4.rb, line 912 def self.summarize(*args) # one network? no need to summarize return [args.first.network] if args.size == 1 i = 0 result = args.dup.sort.map{|ip| ip.network} while i < result.size-1 sum = result[i] + result[i+1] result[i..i+1] = sum.first if sum.size == 1 i += 1 end result.flatten! if result.size == args.size # nothing more to summarize return result else # keep on summarizing return self.summarize(*result) end end
Returns a new IPv4 object which is the result of the summarization, if possible, of the two objects
Example:
ip1 = IPAddress("172.16.10.1/24") ip2 = IPAddress("172.16.11.2/24") p (ip1 + ip2).map {|i| i.to_string} #=> ["172.16.10.0/23"]
If the networks are not contiguous, returns the two network numbers from the objects
ip1 = IPAddress("10.0.0.1/24") ip2 = IPAddress("10.0.2.1/24") p (ip1 + ip2).map {|i| i.to_string} #=> ["10.0.0.0/24","10.0.2.0/24"]
# File lib/ipaddress/ipv4.rb, line 729 def +(oth) aggregate(*[self,oth].sort.map{|i| i.network}) end
Returns the difference between two IP addresses in unsigned int 32 bits format
Example:
ip1 = IPAddress("172.16.10.0/24") ip2 = IPAddress("172.16.11.0/24") puts ip1 - ip2 #=> 256
# File lib/ipaddress/ipv4.rb, line 703 def -(oth) return (to_u32 - oth.to_u32).abs end
Spaceship operator to compare IPv4 objects
Comparing IPv4 addresses is useful to ordinate them into lists that match our intuitive perception of ordered IP addresses.
The first comparison criteria is the u32 value. For example, 10.100.100.1 will be considered to be less than 172.16.0.1, because, in a ordered list, we expect 10.100.100.1 to come before 172.16.0.1.
The second criteria, in case two IPv4 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 10.100.100.0/24 come before 10.100.100.0/25.
Example:
ip1 = IPAddress "10.100.100.1/8" ip2 = IPAddress "172.16.0.1/16" ip3 = IPAddress "10.100.100.1/16" ip1 < ip2 #=> true ip1 > ip3 #=> false [ip1,ip2,ip3].sort.map{|i| i.to_string} #=> ["10.100.100.1/8","10.100.100.1/16","172.16.0.1/16"]
# File lib/ipaddress/ipv4.rb, line 460 def <=>(oth) return prefix <=> oth.prefix if to_u32 == oth.to_u32 to_u32 <=> oth.to_u32 end
Returns the octet specified by index
ip = IPAddress("172.16.100.50/24") ip[0] #=> 172 ip[1] #=> 16 ip[2] #=> 100 ip[3] #=> 50
# File lib/ipaddress/ipv4.rb, line 270 def [](index) @octets[index] end
Checks whether the ip address belongs to a RFC 791 CLASS A network, no matter what the subnet mask is.
Example:
ip = IPAddress("10.0.0.1/24") ip.a? #=> true
# File lib/ipaddress/ipv4.rb, line 745 def a? CLASSFUL.key(8) === bits end
Returns the address portion of the IPv4 object as a string.
ip = IPAddress("172.16.100.4/22") ip.address #=> "172.16.100.4"
# File lib/ipaddress/ipv4.rb, line 103 def address @address end
Checks whether the ip address belongs to a RFC 791 CLASS B network, no matter what the subnet mask is.
Example:
ip = IPAddress("172.16.10.1/24") ip.b? #=> true
# File lib/ipaddress/ipv4.rb, line 761 def b? CLASSFUL.key(16) === bits end
Returns the address portion of an IP in binary format, as a string containing a sequence of 0 and 1
ip = IPAddress("127.0.0.1") ip.bits #=> "01111111000000000000000000000001"
# File lib/ipaddress/ipv4.rb, line 284 def bits data.unpack("B*").first end
Returns the broadcast address for the given IP.
ip = IPAddress("172.16.10.64/24") ip.broadcast.to_s #=> "172.16.10.255"
# File lib/ipaddress/ipv4.rb, line 296 def broadcast self.class.parse_u32(broadcast_u32, @prefix) end
Returns the broadcast address in Unsigned 32bits format
ip = IPaddress("10.0.0.1/29") ip.broadcast_u32 #=> 167772167
# File lib/ipaddress/ipv4.rb, line 517 def broadcast_u32 network_u32 + size - 1 end
Checks whether the ip address belongs to a RFC 791 CLASS C network, no matter what the subnet mask is.
Example:
ip = IPAddress("192.168.1.1/30") ip.c? #=> true
# File lib/ipaddress/ipv4.rb, line 777 def c? CLASSFUL.key(24) === bits end
Returns the address portion of an IPv4 object in a network byte order format.
ip = IPAddress("172.16.10.1/24") ip.data #=> "\254\020\n\001"
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 ip = IPAddress("10.1.1.0/24") binary_data = ["Address: "].pack("a*") + ip.data # Send binary data a.puts binary_data
# File lib/ipaddress/ipv4.rb, line 252 def data [@u32].pack("N") end
Iterates over all the IP addresses for the given network (or IP address).
The object yielded is a new IPv4 object created from the iteration.
ip = IPAddress("10.0.0.1/29") ip.each do |i| p i.address end #=> "10.0.0.0" #=> "10.0.0.1" #=> "10.0.0.2" #=> "10.0.0.3" #=> "10.0.0.4" #=> "10.0.0.5" #=> "10.0.0.6" #=> "10.0.0.7"
# File lib/ipaddress/ipv4.rb, line 422 def each (network_u32..broadcast_u32).each do |i| yield self.class.parse_u32(i, @prefix) end end
Iterates over all the hosts IP addresses for the given network (or IP address).
ip = IPAddress("10.0.0.1/29") ip.each_host do |i| p i.to_s end #=> "10.0.0.1" #=> "10.0.0.2" #=> "10.0.0.3" #=> "10.0.0.4" #=> "10.0.0.5" #=> "10.0.0.6"
# File lib/ipaddress/ipv4.rb, line 395 def each_host (network_u32+1..broadcast_u32-1).each do |i| yield self.class.parse_u32(i, @prefix) end end
Returns a new IPv4 object with the first host IP address in the range.
Example: given the 192.168.100.0/24 network, the first host IP address is 192.168.100.1.
ip = IPAddress("192.168.100.0/24") ip.first.to_s #=> "192.168.100.1"
The object IP doesn't need to be a network: the method automatically gets the network number from it
ip = IPAddress("192.168.100.50/24") ip.first.to_s #=> "192.168.100.1"
# File lib/ipaddress/ipv4.rb, line 350 def first self.class.parse_u32(network_u32+1, @prefix) end
Returns an array with the IP addresses of all the hosts in the network.
ip = IPAddress("10.0.0.1/29") ip.hosts.map {|i| i.address} #=> ["10.0.0.1", #=> "10.0.0.2", #=> "10.0.0.3", #=> "10.0.0.4", #=> "10.0.0.5", #=> "10.0.0.6"]
# File lib/ipaddress/ipv4.rb, line 493 def hosts to_a[1..-2] end
Checks whether a subnet includes the given IP address.
Accepts an IPAddress::IPv4 object.
ip = IPAddress("192.168.10.100/24") addr = IPAddress("192.168.10.102/24") ip.include? addr #=> true ip.include? IPAddress("172.16.0.48/16") #=> false
# File lib/ipaddress/ipv4.rb, line 536 def include?(oth) @prefix <= oth.prefix and network_u32 == (oth.to_u32 & @prefix.to_u32) end
Checks whether a subnet includes all the given IPv4 objects.
ip = IPAddress("192.168.10.100/24") addr1 = IPAddress("192.168.10.102/24") addr2 = IPAddress("192.168.10.103/24") ip.include_all?(addr1,addr2) #=> true
# File lib/ipaddress/ipv4.rb, line 552 def include_all?(*others) others.all? {|oth| include?(oth)} end
Like its sibling method IPv4#first, this method returns a new IPv4 object with the last host IP address in the range.
Example: given the 192.168.100.0/24 network, the last host IP address is 192.168.100.254
ip = IPAddress("192.168.100.0/24") ip.last.to_s #=> "192.168.100.254"
The object IP doesn't need to be a network: the method automatically gets the network number from it
ip = IPAddress("192.168.100.50/24") ip.last.to_s #=> "192.168.100.254"
# File lib/ipaddress/ipv4.rb, line 375 def last self.class.parse_u32(broadcast_u32-1, @prefix) end
Returns the prefix as a string in IP format
ip = IPAddress("172.16.100.4/22") ip.netmask #=> "255.255.252.0"
# File lib/ipaddress/ipv4.rb, line 191 def netmask @prefix.to_ip end
Like IPv4#prefix=, this method allow you to change the prefix / netmask of an IP address object.
ip = IPAddress("172.16.100.4") puts ip #=> 172.16.100.4/16 ip.netmask = "255.255.252.0" puts ip #=> 172.16.100.4/22
# File lib/ipaddress/ipv4.rb, line 210 def netmask=(addr) @prefix = Prefix32.parse_netmask(addr) end
Returns a new IPv4 object with the network number for the given IP.
ip = IPAddress("172.16.10.64/24") ip.network.to_s #=> "172.16.10.0"
# File lib/ipaddress/ipv4.rb, line 326 def network self.class.parse_u32(network_u32, @prefix) end
Checks if the IP address is actually a network
ip = IPAddress("172.16.10.64/24") ip.network? #=> false ip = IPAddress("172.16.10.64/26") ip.network? #=> true
# File lib/ipaddress/ipv4.rb, line 313 def network? @u32 | @prefix.to_u32 == @prefix.to_u32 end
Returns the network number in Unsigned 32bits format
ip = IPAddress("10.0.0.1/29") ip.network_u32 #=> 167772160
# File lib/ipaddress/ipv4.rb, line 505 def network_u32 @u32 & @prefix.to_u32 end
Returns the address as an array of decimal values
ip = IPAddress("172.16.100.4") ip.octets #=> [172, 16, 100, 4]
# File lib/ipaddress/ipv4.rb, line 153 def octets @octets end
Returns the prefix portion of the IPv4 object as a IPAddress::Prefix32 object
ip = IPAddress("172.16.100.4/22") ip.prefix #=> 22 ip.prefix.class #=> IPAddress::Prefix32
# File lib/ipaddress/ipv4.rb, line 119 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 IPv4::parse_u32 or if the object was created using the classful mask.
ip = IPAddress("172.16.100.4") puts ip #=> 172.16.100.4/16 ip.prefix = 22 puts ip #=> 172.16.100.4/22
# File lib/ipaddress/ipv4.rb, line 141 def prefix=(num) @prefix = Prefix32.new(num) end
Checks if an IPv4 address objects belongs to a private network RFC1918
Example:
ip = IPAddress "10.1.1.1/24" ip.private? #=> true
# File lib/ipaddress/ipv4.rb, line 566 def private? [self.class.new("10.0.0.0/8"), self.class.new("172.16.0.0/12"), self.class.new("192.168.0.0/16")].any? {|i| i.include? self} end
Returns the IP address in in-addr.arpa format for DNS lookups
ip = IPAddress("172.16.100.50/24") ip.reverse #=> "50.100.16.172.in-addr.arpa"
# File lib/ipaddress/ipv4.rb, line 581 def reverse @octets.reverse.join(".") + ".in-addr.arpa" end
Returns the number of IP addresses included in the network. It also counts the network address and the broadcast address.
ip = IPAddress("10.0.0.1/29") ip.size #=> 8
# File lib/ipaddress/ipv4.rb, line 475 def size 2 ** @prefix.host_prefix end
Splits a network into different subnets
If the IP Address is a network, it can be divided into multiple networks. If self is not a network, this method will calculate the network from the IP and then subnet it.
If subnets is an power of two number, the resulting networks will be divided evenly from the supernet.
network = IPAddress("172.16.10.0/24") network / 4 # implies map{|i| i.to_string} #=> ["172.16.10.0/26", "172.16.10.64/26", "172.16.10.128/26", "172.16.10.192/26"]
If num is any other number, the supernet will be divided into some networks with a even number of hosts and other networks with the remaining addresses.
network = IPAddress("172.16.10.0/24") network / 3 # implies map{|i| i.to_string} #=> ["172.16.10.0/26", "172.16.10.64/26", "172.16.10.128/25"]
Returns an array of IPv4 objects
# File lib/ipaddress/ipv4.rb, line 618 def split(subnets=2) unless (1..(2**@prefix.host_prefix)).include? subnets raise ArgumentError, "Value #{subnets} out of range" end networks = subnet(newprefix(subnets)) until networks.size == subnets networks = sum_first_found(networks) end return networks end
This method implements the subnetting function similar to the one described in RFC3531.
By specifying a new prefix, the method calculates the network number for the given IPv4 object and calculates the subnets associated to the new prefix.
For example, given the following network:
ip = IPAddress "172.16.10.0/24"
we can calculate the subnets with a /26 prefix
ip.subnets(26).map{&:to_string) #=> ["172.16.10.0/26", "172.16.10.64/26", "172.16.10.128/26", "172.16.10.192/26"]
The resulting number of subnets will of course always be a power of two.
# File lib/ipaddress/ipv4.rb, line 682 def subnet(subprefix) unless ((@prefix.to_i)..32).include? subprefix raise ArgumentError, "New prefix must be between #@prefix and 32" end Array.new(2**(subprefix-@prefix.to_i)) do |i| self.class.parse_u32(network_u32+(i*(2**(32-subprefix))), subprefix) end end
Returns a new IPv4 object from the supernetting of the instance network.
Supernetting is similar to subnetting, except that you getting as a result a network with a smaller prefix (bigger host space). For example, given the network
ip = IPAddress("172.16.10.0/24")
you can supernet it with a new /23 prefix
ip.supernet(23).to_string #=> "172.16.10.0/23"
However if you supernet it with a /22 prefix, the network address will change:
ip.supernet(22).to_string #=> "172.16.8.0/22"
If new_prefix is less than 1, returns 0.0.0.0/0
# File lib/ipaddress/ipv4.rb, line 654 def supernet(new_prefix) raise ArgumentError, "New prefix must be smaller than existing prefix" if new_prefix >= @prefix.to_i return self.class.new("0.0.0.0/0") if new_prefix < 1 return self.class.new(@address+"/#{new_prefix}").network end
Returns a string with the address portion of the IPv4 object
ip = IPAddress("172.16.100.4/22") ip.to_s #=> "172.16.100.4"
# File lib/ipaddress/ipv4.rb, line 166 def to_s @address end
Returns a string with the IP address in canonical form.
ip = IPAddress("172.16.100.4/22") ip.to_string #=> "172.16.100.4/22"
# File lib/ipaddress/ipv4.rb, line 179 def to_string "#@address/#@prefix" end
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