Class: NetAddr::EUI

Inherits:
Object
  • Object
show all
Defined in:
lib/eui.rb

Overview

EUI - Extended Unique Identifier

A class & series of methods for creating and manipulating Extended Unique Identifier (EUI) addresses. Two types of address formats are supported EUI-48 and EUI-64. The most common use for this class will be to manipulate MAC addresses (which are essentially a type of EUI-48 address).

EUI addresses are separated into two parts, the Organizationally Unique Identifier (OUI) and the Extended Identifier (EI). The OUI is assigned by the IEEE and is used to identify a particular hardware manufacturer. The EI is assigned by the hardware manufacturer as a per device unique address.

Probably the most useful feature of this class, and thus the reason it was created, is to help automate certain address assignments within IP. For example, IPv6 Link Local addresses use MAC addresses for IP auto-assignment and multicast MAC addresses are determined based on the multicast IP address.

Direct Known Subclasses

EUI48, EUI64

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(eui) ⇒ EUI

Synopsis

This method performs absolutely no error checking, and is meant to be used only by other internal methods for the sake of the speedier creation of EUI objects. Please consider using #create unless you know what you are doing with 100% certainty.

Example: NetAddr::EUI48.new(‘aabbccddeeff’)

Arguments:

  • EUI as a String or Integer. Strings should contain no formatting characters.



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# File 'lib/eui.rb', line 35

def initialize(eui)

    if (eui.kind_of?(Integer))
        @eui_i = eui
        @eui = eui.to_s(16)
        if ( self.kind_of?(NetAddr::EUI48) )
            @eui = '0' * (12 - @eui.length) << @eui if (@eui.length < 12)
        else
            @eui = '0' * (16 - @eui.length) << @eui if (@eui.length < 16)
        end

    elsif(eui.kind_of?(String))
        @eui = eui
        @eui_i = eui.to_i(16)
    else
        raise ArgumentError, "Expected String or Integer, but #{eui.class} provided."
    end

    # set ei & oui
    if ( self.kind_of?(NetAddr::EUI48) )
        @ei = @eui.slice(6..11)
    else
        @ei = @eui.slice(6..15)
    end

    @oui = @eui.slice(0..5)

end

Class Method Details

.create(eui) ⇒ Object

Synopsis

Create a new EUI48 or EUI64 object.

Example: addr = NetAddr::EUI.create(‘aa-bb-cc-dd-ee-ff’) addr = NetAddr::EUI.create(‘aa:bb:cc:dd:ee:ff’) addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr = NetAddr::EUI.create(‘aa-bb-cc-dd-ee-ff-00-01’)

Arguments

  • eui = EUI as a String

Returns

  • EUI48 or EUI64 object



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# File 'lib/eui.rb', line 79

def EUI.create(eui)
    if (!eui.kind_of? String)
        raise ArgumentError, "Expected String, but #{eui.class} provided."
    end

    # create local copy & validate
    eui = eui.dup
    NetAddr.validate_eui(eui)

    # remove formatting characters
    eui.gsub!(/[\.\:\-]/, '')

    if (eui.length == 12)
        eui = NetAddr::EUI48.new(eui)
    else
        eui = NetAddr::EUI64.new(eui)
    end

    return(eui)
end

Instance Method Details

#address(options = nil) ⇒ Object

Synopsis

Returns EUI address. The default address format is xxxx.xxxx.xxxx

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.address(:Delimiter => ‘-’) => “aa-bb-cc-dd-ee-ff” addr.address(:Delimiter => ‘:’) => “aa:bb:cc:dd:ee:ff”

Arguments:

  • options = Hash with the following fields:

    :Delimiter -- delimitation character. valid values are (- : .)

Returns:

  • String



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# File 'lib/eui.rb', line 115

def address(options=nil)
    known_args = [:Delimiter]
    delimiter = '-'

    if (options)
        if (!options.kind_of? Hash)
            raise ArgumentError, "Expected Hash, but #{options.class} provided."
        end
        NetAddr.validate_args(options.keys,known_args)

        if (options.has_key?(:Delimiter))
            delimiter = options[:Delimiter]
            delimiter = '-' if (delimiter != ':' && delimiter != '.')
        end
    end

    if (delimiter == '-' || delimiter == ':')
        addr = octets.join(delimiter)
    elsif (delimiter == '.')
        addr = octets.each_slice(2).to_a.map(&:join).join('.')
    end

    return(addr)
end

#ei(options = nil) ⇒ Object

Synopsis

Returns Extended Identifier portion of an EUI address (the vendor assigned ID). The default address format is xx-xx-xx

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.ei(:Delimiter => ‘-’) => “dd-ee-ff”

Arguments:

  • options = Hash with the following fields:

    :Delimiter -- delimitation character. valid values are (-, and :)

Returns:

  • String



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# File 'lib/eui.rb', line 155

def ei(options=nil)
    known_args = [:Delimiter]
    delimiter = '-'

    if (options)
        if (!options.kind_of? Hash)
            raise ArgumentError, "Expected Hash, but #{options.class} provided."
        end
        NetAddr.validate_args(options.keys,known_args)

        if (options.has_key?(:Delimiter))
            if (options[:Delimiter] == ':')
                delimiter = options[:Delimiter]
            end
        end
    end

    if ( self.kind_of?(NetAddr::EUI48) )
        ei = octets[3..5].join(delimiter)
    else
        ei = octets[3..7].join(delimiter)
    end

    return(ei)
end

#link_local(options = nil) ⇒ Object

Synopsis

Provide an IPv6 Link Local address based on the current EUI address.

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.link_local() => “fe80:0000:0000:0000:aabb:ccff:fedd:eeff”

Arguments:

  • options = Hash with the following fields:

    :Short -- if true, return IPv6 addresses in short-hand notation
:Objectify -- if true, return CIDR objects

Returns:

  • CIDR address String or an NetAddr::CIDR object



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# File 'lib/eui.rb', line 196

def link_local(options=nil)
    return( self.to_ipv6('fe80::/64', options) )
end

#oui(options = nil) ⇒ Object

Synopsis

Returns Organizationally Unique Identifier portion of an EUI address (the vendor ID). The default address format is xx-xx-xx.

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.oui(:Delimiter => ‘-’) => “aa-bb-cc”

Arguments:

  • options = Hash with the following fields:

    :Delimiter -- delimitation character. valid values are (-, and :)

Returns:

  • String



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# File 'lib/eui.rb', line 215

def oui(options=nil)
    known_args = [:Delimiter]
    delimiter = '-'

    if (options)
        if (!options.kind_of? Hash)
            raise ArgumentError, "Expected Hash, but #{options.class} provided."
        end
        NetAddr.validate_args(options.keys,known_args)

        if (options.has_key?(:Delimiter))
            if (options[:Delimiter] == ':')
                delimiter = options[:Delimiter]
            end
        end
    end
    oui = octets[0..2].join(delimiter)

    return(oui)
end

#to_i ⇒ Object

Synopsis

Returns the EUI as an Integer.

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.to_i => 187723572702975

Arguments:

  • none

Returns:

  • Integer



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# File 'lib/eui.rb', line 249

def to_i()
    return(@eui_i)
end

#to_ipv6(cidr, options = nil) ⇒ Object

Synopsis

Given a valid IPv6 subnet, return an IPv6 address based on the current EUI.

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.to_ipv6(‘3ffe::/64’) => “3ffe:0000:0000:0000:a8bb:ccff:fedd:eeff”

Arguments:

  • options = Hash with the following fields:

    :Short -- if true, return IPv6 addresses in short-hand notation
:Objectify -- if true, return CIDR objects

Returns:

  • IPv6 address String or an NetAddr::CIDRv6 object



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# File 'lib/eui.rb', line 268

def to_ipv6(cidr, options=nil)
    known_args = [:Short, :Objectify]
    objectify = false
    short = false

    if ( !cidr.kind_of?(NetAddr::CIDR) )
        begin
            cidr = NetAddr::CIDR.create(cidr)
        rescue Exception => error
            raise ArgumentError, "CIDR raised the following errors: #{error}"
        end
    elsif (cidr.kind_of?(NetAddr::CIDRv4)  )
        raise ArgumentError, "Expected CIDRv6, but #{cidr.class} provided."
    end

    if (cidr.bits > 64)
        raise ValidationError, "Prefix length of provided CIDR must be /64 or less but was #{cidr.netmask}."
    end

    if (options)
        if (!options.kind_of? Hash)
            raise ArgumentError, "Expected Hash, but #{options.class} provided."
        end
        NetAddr.validate_args(options.keys,known_args)

        if (options.has_key?(:Objectify) && options[:Objectify] == true)
            objectify = true
        end

        if (options.has_key?(:Short) && options[:Short] == true)
            short = true
        end
    end

    # get integer equiv of addr. conver eui48 to eui64 if needed
    if ( self.kind_of?(NetAddr::EUI48) )
        eui_i = self.to_eui64.to_i
    else
        eui_i = self.to_i
    end
  
    # toggle u/l bit
    eui_i = eui_i ^ 0x0200000000000000

    # create ipv6 address
    ipv6 = cidr.to_i | eui_i

    if (!objectify)
        ipv6 = NetAddr.i_to_ip(ipv6, :Version => 6)
        ipv6 = NetAddr.shorten(ipv6) if (short)
    else
        ipv6 = NetAddr::CIDRv6.new(ipv6)
    end

    return(ipv6)
end

#to_s ⇒ Object

Synopsis

Returns the EUI as an unformatted String.

Example: addr = NetAddr::EUI.create(‘aabb.ccdd.eeff’) addr.to_s => “aabbccddeeff”

Arguments:

  • none

Returns:

  • String



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# File 'lib/eui.rb', line 338

def to_s()
    return(@eui)
end