Class: IpMask

Inherits:
Object
  • Object
show all
Defined in:
lib/cf_factory/help/ip_mask.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ip_mask, bits = 32) ⇒ IpMask

if one parameter specified, means it’s not a range, it’s one address



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# File 'lib/cf_factory/help/ip_mask.rb', line 4

def initialize(ip_mask, bits = 32) #if one parameter specified, means it's not a range, it's one address
  @ip_mask = ip_mask
  @bits = bits.to_i
end

Instance Attribute Details

#bits ⇒ Object (readonly)

Returns the value of attribute bits.



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# File 'lib/cf_factory/help/ip_mask.rb', line 2

def bits
  @bits
end

#ip_mask ⇒ Object (readonly)

Returns the value of attribute ip_mask.



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# File 'lib/cf_factory/help/ip_mask.rb', line 2

def ip_mask
  @ip_mask
end

Class Method Details

.create(ip_mask, bits = 32) ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 9

def self.create(ip_mask, bits = 32)
  cleaned = IpMask.new(ip_mask, bits)
  cleaned.clean_mask()
end

.create_from_cidr(cidr) ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 14

def self.create_from_cidr(cidr)
  #ip  = cidr.split("/")[0].split(".")
  #bits  = cidr.split("/")[1].to_i
  ip = cidr.split("/")[0]
  bits = cidr.split("/")[1]
  IpMask.new(ip, bits)
end

.create_from_num(number, bits) ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 22

def self.create_from_num(number, bits)
  ip_bytes = []
  3.downto(0) {|i|
    div = 256 ** i
    b = number/div.to_i
    ip_bytes << b.to_i
    number = number % div
  }
  ip_bytes
  IpMask.new(ip_bytes.join("."), bits)
end

Instance Method Details

#==(comp) ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 160

def ==(comp)
  puts "comp = #{comp.class} #{comp.inspect}"
  self.ip_mask == comp.ip_mask && self.bits == comp.bits
end

#are_all_in_range?(ip_mask) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cf_factory/help/ip_mask.rb', line 148

def are_all_in_range?(ip_mask)
  #puts "check for #{ip_mask}"
  return false if ip_mask.bits < self.bits
  #
  comp_ip = ip_mask.to_num
  ip_base_num = self.to_num
  ip_bits_num = self.to_mask
  ip_clean = ip_base_num & ip_bits_num
  #puts "comp = #{(comp_ip & ip_bits_num)} ip_clean = #{ip_clean} (ip_bits_num = #{ip_bits_num})"
  (comp_ip & ip_bits_num) == ip_clean
end

#clean_mask ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 75

def clean_mask
  ip_base_num = self.to_num
  ip_bits_num = self.to_mask()
  clean_mask = ip_base_num & ip_bits_num
  #puts "clean_mask = #{clean_mask}"
  IpMask.create_from_num(clean_mask,@bits)
end

#divide(number_of_addresses) ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 88

def divide(number_of_addresses)
  possible_ranges = []
  bits_to_move = (Math.log(number_of_addresses+1)/Math.log(2)).to_i
  puts "asked to allocate #{number_of_addresses}; that corresponds to #{bits_to_move} bits"
  puts "#{self.free()} are free"
  max_subnets = self.free()/number_of_addresses
  puts "given that every subnet should have #{number_of_addresses} addresses, there is currently space for #{max_subnets}"
  0.upto(max_subnets-1) {|i|
    num = self.to_num()
    num += i*number_of_addresses
    possible_range = IpMask.create_from_num(num, 32 - bits_to_move)
    possible_ranges << possible_range
    puts "possible range: #{possible_range}"
  }
  possible_ranges
end

#divide_individually(array_with_number_of_addresses) ⇒ Object

Takes an array of IP-Address-Numbers into account and allocates corresponding IP address ranges



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# File 'lib/cf_factory/help/ip_mask.rb', line 106

def divide_individually(array_with_number_of_addresses)
  possible_ranges = []
  num = self.to_num()
  bits_to_move = 32 - @bits
  remaining_addresses = self.free
  array_with_number_of_addresses.each() {|number_of_addresses_for_subnet|
    if (2 ** bits_to_move) < number_of_addresses_for_subnet
      puts "WARNING: could not allocate #{number_of_addresses_for_subnet} anymore (max #{(2 ** bits_to_move)})"
      next
    end        
    bits_to_move = [(Math.log(number_of_addresses_for_subnet+1)/Math.log(2)).to_i, bits_to_move].min      
    possible_range = IpMask.create_from_num(num, 32 - bits_to_move)
    unless self.are_all_in_range?(possible_range)
      puts "WARNING: the selected range '#{possible_range}' is outside the base range"
      next
    end
    num += number_of_addresses_for_subnet
    puts "[alloc #{number_of_addresses_for_subnet}] \tpossible range: #{possible_range}"
    possible_ranges << possible_range
    remaining_addresses -= (2 ** bits_to_move)
    #puts "[to allocate = #{number_of_addresses_for_subnet}] => free = #{possible_range.free}"
  }
  possible_ranges
end

#free ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 55

def free()
  (2 ** 32) / used()
end

#generate_free ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 63

def generate_free()
  self.to_num()
end

#is_clean? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cf_factory/help/ip_mask.rb', line 83

def is_clean?
  comp = self.clean_mask
  return self.ip_mask != comp.ip_mask
end

#is_in_range?(ip_address) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cf_factory/help/ip_mask.rb', line 131

def is_in_range?(ip_address)
  comp_mask = IpMask.new(ip_address)
  # transform ip address string to numerical values for bitwise operations
  comp_ip = comp_mask.to_num
  #puts "ip_address checked = #{comp_ip.to_s(2)}"
  ip_base_num = self.to_num
  #puts "range_mask         = #{ip_base_num.to_s(2)}"
  ip_bits_num = self.to_mask
  #puts "bit_mask           = #{ip_bits_num.to_s(2)}"
  # perform an AND operation to get rid of the bits in the mask that don't count
  clean_mask = ip_base_num & ip_bits_num
  #puts "cleaned range_mask = #{ip_base_num.to_s(2)}"
  # the ip address belongs to the range, when an AND with the bitmask equals the cleaned mask
  #puts "(ip_address&bits   = #{(comp_ip & ip_bits_num).to_s(2)}"
  (comp_ip & ip_bits_num) == clean_mask
end

#to_bit_string ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 49

def to_bit_string    
  bit_string = ("1"*@bits+"0"*(32-@bits))
  #puts "#{bit_string}"
  bit_string
end

#to_mask ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 44

def to_mask
  bit_string = self.to_bit_string 
  r = bit_string.to_i(2)
end

#to_num ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 34

def to_num
  sum = 0
  exp = 3
  @ip_mask.split(".").each() {|ip|
    sum += ip.to_i * (256 ** exp)
    exp -= 1
  }
  sum
end

#to_s ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 67

def to_s
  if @bits.to_i == 32
    "#{@ip_mask}"
  else
    "#{@ip_mask}/#{@bits}"
  end
end

#used ⇒ Object 



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# File 'lib/cf_factory/help/ip_mask.rb', line 59

def used()
  2 ** @bits 
end