Inet.coffee

inet.coffee

IP_ADDRESS_REGEX = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/
CIDR_ADDRESS_REGEX =  /^(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\/(\d{1,2})$/


class @Inet

  constructor: (ipAddress)->
    if typeof ipAddress == 'number'
      @ipAddressNumber = ipAddress
      @ipAddress = Inet.numberToAddress(ipAddress)
    else
      @ipAddress = ipAddress
      @ipAddressNumber = Inet.addressToNumber(ipAddress)

  isInSubNet: (subnetCidr) ->
    {ipAddressNumber: subNetAddress, mask: mask} = Inet.subNetToNumberAndMask(subnetCidr)
    return (@ipAddressNumber & mask) == (subNetAddress & mask)

  isPrivateAddress: ()->
    @isInSubNet('127.0.0.1/0') or @isInSubNet('10.0.0.0/24') or @isInSubNet('172.16.0.0/20') or @isInSubNet('192.168.0.0/16')

  @addressToNumber: (ipAddress)->
    components = ipAddress.match(IP_ADDRESS_REGEX)
    unless components?
      throw new Error("Not a valid IPv4 Address '#{ipAddress}'")

    components.shift() #destroy first entry

    ipAddressNumber = 0
    multiplicand = 1
    for component in components
      ipAddressNumber += parseInt(component) * multiplicand
      multiplicand *= 256
    return ipAddressNumber


  @numberToAddress: (ipAddressNumber)->
    components = []
    for i in [3...0]
      components[i] = (ipAddressNumber % 256).toFixed(0)
      ipAddressNumber = Math.floor(ipAddressNumber / 256)
    return components.join('.')

  @subNetToNumberAndMask: (subnetCidr)->
    matches = subnetCidr.match(CIDR_ADDRESS_REGEX)
    unless matches?
      throw new Error("Not a valid IPv4 CIDR Notation '#{subnetCidr}'")

    [tmp, ipAddress, prefixSize] = matches

    return {
      ipAddressNumber: Inet.addressToNumber(ipAddress),
      mask: Inet.prefixSizeToMask(prefixSize)
    }

  @prefixSizeToMask: (prefixSize)->
    return ((1 << (32 - prefixSize)) - 1) ^ 0xFFFFFFFF