ip-subnet/lib/cidr.js

A library of IP Subnetting utility functions

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.CIDR = void 0;
const ip_1 = require("./ip");
class CIDR {
    constructor(networkAddress, prefixLength) {
        if (prefixLength > 0 && prefixLength <= 32) {
            this._prefixLength = prefixLength;
            this._netMask = this.calculateNetMask(prefixLength);
            this._networkAddress = networkAddress.getNetworkAddress(this._netMask);
        }
        else {
            throw new Error(`Invalid prefix length: ${prefixLength}. It should be between 0-32`);
        }
    }
    toString() {
        return `${this.networkAddress}/${this.prefixLength}`;
    }
    calculateOctetMask(bitsUsed) {
        let octetMask = 0;
        if (bitsUsed !== 0) {
            for (let i = 1; i <= bitsUsed; i++) {
                octetMask += Math.pow(2, 8 - i);
            }
        }
        return octetMask;
    }
    calculateNetMask(prefixLength) {
        const netMask = [];
        for (let i = 0; i < 4; i++) {
            let bitsUsed = 8;
            if (prefixLength === 0) {
                netMask.push(0);
                continue;
            }
            if (this._prefixLength < 8) {
                bitsUsed = prefixLength;
            }
            netMask.push(this.calculateOctetMask(bitsUsed));
            prefixLength -= bitsUsed;
        }
        return new ip_1.IP(netMask.join('.'));
    }
    get netMask() {
        return this._netMask;
    }
    get networkAddress() {
        return this._networkAddress;
    }
    get prefixLength() {
        return this._prefixLength;
    }
    static parse(cidr) {
        const c = cidr.split('/');
        const prefixLength = +c[1];
        const ipAddress = new ip_1.IP(c[0]);
        if (c.length !== 2 || isNaN(prefixLength) || prefixLength < 0 || prefixLength > 32) {
            throw new Error(`Invalid CIDR: ${cidr}`);
        }
        return new CIDR(ipAddress, prefixLength);
    }
}
exports.CIDR = CIDR;