node-red-contrib-knx-ultimate/KNXEngine/util/ipAddressHelper.js

Control your KNX intallation via Node-Red! Single Node KNX IN/OUT with optional ETS group address importer. Easy to use and highly configurable.

// Helper for ipaddresses
const knxLog = require('../KnxLog');
const os = require('os');

//#region  "GET LOCAL INTERFACE PROPERTIES"
function getIPv4Interfaces () {
    // get the local address of the IPv4 interface we're going to use
    let candidateInterfaces = {}
    let interfaces = os.networkInterfaces()
    for (let iface in interfaces) {
        for (let key in interfaces[iface]) {
            let intf = interfaces[iface][key]
            // 11/05/2022 Fixed a breaking change introduced by node 18 (https://nodejs.org/api/os.html#osnetworkinterfaces)
            // In Node < 18, intf.family is a string "IPv4" or "IPv6", from node 18, is an integer, for example 4.
            try {
                knxLog.get().debug('ipAddressHelper.js: parsing interface: %s (%j)', iface, intf);
                if (intf.family !== undefined && intf.family.toString().includes("4") && !intf.internal) { 
                    knxLog.get().trace('ipAddressHelper.js: Found suitable interface: %s (%j)', iface, intf);
                    candidateInterfaces[iface] = intf
                } else {
                    knxLog.get().trace('ipAddressHelper.js: Found NOT suitable interface: %s (%j)', iface, intf);
                }    
            } catch (error) {
                knxLog.get().error("ipAddressHelper.js: getIPv4Interfaces: error parsing the interface %s (%j)", iface, intf);
            }            
        }
    }

    return candidateInterfaces
}

exports.getLocalAddress = function (_interface = "") {
    knxLog.get().trace("ipAddressHelper.js: getLocalAddress: getting interfaces");
    let candidateInterfaces = getIPv4Interfaces();
    // if user has declared a desired interface then use it
    if (_interface !== "") {
        if (!candidateInterfaces.hasOwnProperty(_interface)) {
            knxLog.get().error("ipAddressHelper.js: exports.getLocalAddress: Interface " + _interface + " not found or has no useful IPv4 address!");
            throw Error('Interface ' + _interface + ' not found or has no useful IPv4 address!');
        } else {
            return candidateInterfaces[_interface].address
        }
    }

    // just return the first available IPv4 non-loopback interface
    if (Object.keys(candidateInterfaces).length > 0) {
        return candidateInterfaces[Object.keys(candidateInterfaces)[0]].address
    }
    // no local IpV4 interfaces?
    throw Error('No valid IPv4 interfaces detected')
}
//#endregion