Class: NetAddr::Mask128

Inherits:
Object
  • Object
show all
Defined in:
lib/mask128.rb

Overview

Mask128 represents a 128-bit netmask.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(prefix_len) ⇒ Mask128

Create a Mask128 from an Integer prefix length. Valid values are 0-128. Throws ValidationError on error.



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# File 'lib/mask128.rb', line 13

def initialize(prefix_len)
	if (!prefix_len.kind_of?(Integer))
		raise ValidationError, "Expected an Integer for 'prefix_len' but got a #{prefix_len.class}."
	elsif ( (prefix_len < 0) || (prefix_len > 128) )
		raise ValidationError, "#{prefix_len} must be in the range of 0-128."
	end
	@prefix_len = prefix_len
	@mask = NetAddr::F128 ^ (NetAddr::F128 >> @prefix_len)
end

Instance Attribute Details

#mask ⇒ Object (readonly)

mask is the Integer representation of this netmask



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# File 'lib/mask128.rb', line 6

def mask
  @mask
end

#prefix_len ⇒ Object (readonly)

prefix_len is the Integer prefix length of this netmask



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# File 'lib/mask128.rb', line 9

def prefix_len
  @prefix_len
end

Class Method Details

.parse(mask) ⇒ Object

parse will create an Mask128 from its string representation. arguments:

  • mask - String representing an netmask (ie. “/64”).

Throws ValidationError on error.



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# File 'lib/mask128.rb', line 28

def Mask128.parse(mask)
	mask = mask.strip
	if (mask.start_with?("/")) # cidr format
		mask = mask[1..-1] # remove "/"
	end
	return Mask128.new(Integer(mask))
rescue ArgumentError
	raise ValidationError, "#{mask} is not valid integer."
end

Instance Method Details

#cmp(other) ⇒ Object

cmp compares equality with another Mask128. Return:

  • 1 if this Mask128 is larger in capacity

  • 0 if the two are equal

  • -1 if this Mask128 is smaller in capacity



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# File 'lib/mask128.rb', line 42

def cmp(other)
	if (!other.kind_of?(Mask128))
		raise ArgumentError, "Expected an Mask128 object for 'other' but got a #{other.class}."
	end
	if (self.prefix_len < other.prefix_len)
		return 1
	elsif (self.prefix_len > other.prefix_len)
		return -1
	end
	return 0
end

#len ⇒ Object

len returns the number of IP addresses in this network. This is only useful if you have a subnet smaller than a /64 as it will always return 0 for prefixes <= 64.



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# File 'lib/mask128.rb', line 56

def len()
	if (self.prefix_len <= 64)
		return 0
	end
	return (self.mask ^ NetAddr::F128) + 1 # bit flip the netmask and add 1
end

#to_s ⇒ Object

to_s returns the Mask128 as a String



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# File 'lib/mask128.rb', line 64

def to_s()
	return "/#{@prefix_len}"
end