cidrhelper.js

// 2018.12.03 Atienza, Chris

// Given a slash specified network (ie: 10.1.1.1/24) returns the low and hi IPs in the defined range
// does not exclude any special reserved addresses
function _cidrToRange(cidr) {
    var range = [2];
    cidr = cidr.split('/');
    var cidr_1 = parseInt(cidr[1])
    range[0] = long2ip((ip2long(cidr[0])) & ((-1 << (32 - cidr_1))));
    start = ip2long(range[0])
    range[1] = long2ip(start + Math.pow(2, (32 - cidr_1)) - 1);
    return range;
} // cidrToRange

function calculateCidrRange(range, bits) {
    if (!bits)
        bits = 32;
    //var [range, bits = 32] = cidr.split('/');
    //var mask = ~(2 ** (32 - bits) - 1);
    var mask1 = ~(Math.pow(2 ^ (32 - bits)) - 1);
    var mask2 = (Math.pow(2 ^ (32 - bits)) - 1);
    return [long2ip(ip2long(range) & mask1), long2ip(ip2long(range) | mask2)];
} // calculateCidrRange

// Converts an Internet standard dotted format string into an IPv4 Internet network address (long)
// *     example : long2ip( '192.0.34.166' );
// *     returns : 3221234342
function ip2long(ip) {
    return ip.split('.').reduce(function (ipInt, octet) { return (ipInt << 8) + parseInt(octet, 10) }, 0) >>> 0;
} // ip2long

// Converts an IPv4 Internet network address into a string in Internet standard dotted format
// *     example : long2ip( 3221234342 );
// *     returns : '192.0.34.166'
function long2ip(ipInt) {
    return ((ipInt >>> 24) + '.' + (ipInt >> 16 & 255) + '.' + (ipInt >> 8 & 255) + '.' + (ipInt & 255));
} // long2ip

// redo below here... this is lazy/brute-force... but it does work
// Converts an Internet standard dotted formart mask into the cidr 'slash' value
// *    example: mask2cidr("255.255.255.0")
// *    returns: "/24"
function mask2cidr(mask) {
    switch (mask) {
        case "0.0.0.0":
            return ret_mask = "/0";
        case "128.0.0.0":
            return ret_mask = "/1";
        case "192.0.0.0":
            return ret_mask = "/2";
        case "224.0.0.0":
            return ret_mask = "/3";
        case "240.0.0.0":
            return ret_mask = "/4";
        case "248.0.0.0":
            return ret_mask = "/5";
        case "252.0.0.0":
            return ret_mask = "/6";
        case "254.0.0.0":
            return ret_mask = "/7";
        case "255.0.0.0":
            return ret_mask = "/8";
        case "255.128.0.0":
            return ret_mask = "/9";
        case "255.192.0.0":
            return ret_mask = "/10";
        case "255.224.0.0":
            return ret_mask = "/11";
        case "255.240.0.0":
            return ret_mask = "/12";
        case "255.248.0.0":
            return ret_mask = "/13";
        case "255.252.0.0":
            return ret_mask = "/14";
        case "255.254.0.0":
            return ret_mask = "/15";
        case "255.255.0.0":
            return ret_mask = "/16";
        case "255.255.128.0":
            return ret_mask = "/17";
        case "255.255.192.0":
            return ret_mask = "/18";
        case "255.255.224.0":
            return ret_mask = "/19";
        case "255.255.240.0":
            return ret_mask = "/20";
        case "255.255.248.0":
            return ret_mask = "/21";
        case "255.255.252.0":
            return ret_mask = "/22";
        case "255.255.254.0":
            return ret_mask = "/23";
        case "255.255.255.0":
            return ret_mask = "/24";
        case "255.255.255.128":
            return ret_mask = "/25";
        case "255.255.255.192":
            return ret_mask = "/26";
        case "255.255.255.224":
            return ret_mask = "/27";
        case "255.255.255.240":
            return ret_mask = "/28";
        case "255.255.255.248":
            return ret_mask = "/29";
        case "255.255.255.252":
            return ret_mask = "/30";
        case "255.255.255.254":
            return ret_mask = "/31";
        case "255.255.255.255":
            return ret_mask = ""
    }
} // mask2cidr

// redo below here... this is lazy/brute-force... but it does work
// Converts a cidr 'slash' value into an Internet standard dotted formart mask
// *    example: cidr2mask("/24")
// *    returns: "255.255.255.0"
function cidr2mask(cidr) {
    switch (cidr) {
        case "/0":
            return "0.0.0.0";
        case "/1":
            return "128.0.0.0";
        case "/2":
            return "192.0.0.0";
        case "/3":
            return "224.0.0.0";
        case "/4":
            return "240.0.0.0";
        case "/5":
            return "248.0.0.0";
        case "/6":
            return "252.0.0.0";
        case "/7":
            return "254.0.0.0";
        case "/8":
            return "255.0.0.0";
        case "/9":
            return "255.128.0.0";
        case "/10":
            return "255.192.0.0";
        case "/11":
            return "255.224.0.0";
        case "/12":
            return "255.240.0.0";
        case "/13":
            return "255.248.0.0";
        case "/14":
            return "255.252.0.0";
        case "/15":
            return "255.254.0.0";
        case "/16":
            return "255.255.0.0";
        case "/17":
            return "255.255.128.0";
        case "/18":
            return "255.255.192.0";
        case "/19":
            return "255.255.224.0";
        case "/20":
            return "255.255.240.0";
        case "/21":
            return "255.255.248.0";
        case "/22":
            return "255.255.252.0";
        case "/23":
            return "255.255.254.0";
        case "/24":
            return "255.255.255.0";
        case "/25":
            return "255.255.255.128";
        case "/26":
            return "255.255.255.192";
        case "/27":
            return "255.255.255.224";
        case "/28":
            return "255.255.255.240";
        case "/29":
            return "255.255.255.248";
        case "/30":
            return "255.255.255.252";
        case "/31":
            return "255.255.255.254";
        case "":
            return "255.255.255.255";
    }
} // cidr2mask