Class: IPHandling

Inherits:
Object
  • Object
show all
Defined in:
lib/ip2cidr/iphandling.rb

Instance Method Summary collapse

Instance Method Details

#iprange_to_cidr(startip, endip) ⇒ Object

iprange_to_cidr Return a list of cidr addresses given a range of ip addresses.

Raises:

  • (ArgumentError) 


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# File 'lib/ip2cidr/iphandling.rb', line 30

def iprange_to_cidr(startip, endip)
  cidr2mask = [0x00000000, 0x80000000, 0xC0000000, 
               0xE0000000, 0xF0000000, 0xF8000000, 
               0xFC000000, 0xFE000000, 0xFF000000, 
               0xFF800000, 0xFFC00000, 0xFFE00000, 
               0xFFF00000, 0xFFF80000, 0xFFFC0000, 
               0xFFFE0000, 0xFFFF0000, 0xFFFF8000, 
               0xFFFFC000, 0xFFFFE000, 0xFFFFF000, 
               0xFFFFF800, 0xFFFFFC00, 0xFFFFFE00, 
               0xFFFFFF00, 0xFFFFFF80, 0xFFFFFFC0, 
               0xFFFFFFE0, 0xFFFFFFF0, 0xFFFFFFF8, 
               0xFFFFFFFC, 0xFFFFFFFE, 0xFFFFFFFF]
  startaddr =  ipstring_to_long(startip)
  endaddr = ipstring_to_long (endip)

  # Check if Ending IP Address is greater than Starting IP Address

  raise ArgumentError, 'Starting IP must be less than the end IP' unless startaddr < endaddr

  cidrlist = Array.new

  while endaddr >= startaddr
    maxsize = 32
    while maxsize > 0
      mask = cidr2mask[maxsize - 1]
      maskedbase = startaddr & mask

      break if maskedbase != startaddr

      maxsize -= 1
    end

    x = Math.log(endaddr - startaddr + 1) / Math.log(2)
    maxdiff = 32 - x.floor
    maxsize = maxdiff if maxsize < maxdiff

    cidrlist.push(long_to_ipstring(startaddr) + "/" + maxsize.to_s)
    startaddr += 2**(32 - maxsize)
  end

  return cidrlist
end

#ipstring_to_long(ipstring) ⇒ Object

ipstring_to_long Convert an ip address in string format to integer.



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# File 'lib/ip2cidr/iphandling.rb', line 4

def ipstring_to_long(ipstring)
  ipstring = ipstring.split(".")
  longip = Array.new(4)
  for i in 0..3
    longip[i] = ipstring[i].to_i
  end

  #return longip

  return (longip[0] << 24) + (longip[1] << 16) + 
         (longip[2] << 8) + longip[3]
end

#long_to_ipstring(longip) ⇒ Object

long_to_ipstring Convert an ip address in integer format to string.



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# File 'lib/ip2cidr/iphandling.rb', line 18

def long_to_ipstring(longip)
  ipstring = ""
  ipstring = (longip >> 24).to_s + "." + 
             ((longip & 0x00FFFFFF)>> 16).to_s + "." + 
             ((longip & 0x0000FFFF) >> 8).to_s + "." + 
             (longip & 0x000000FF).to_s
  return ipstring
end