/** * @description MeshCentral Mesh Agent Local Scanner * @author Ylian Saint-Hilaire * @copyright Intel Corporation 2018-2021 * @license Apache-2.0 * @version v0.0.1 */ /*jslint node: true */ /*jshint node: true */ /*jshint strict:false */ /*jshint -W097 */ /*jshint esversion: 6 */ "use strict"; // Construct a Mesh Scanner object // TODO: We need once "server4" and "server6" per interface, or change the default multicast interface as we send. module.exports.CreateMeshScanner = function (parent) { var obj = {}; obj.parent = parent; obj.dgram = require('dgram'); obj.common = require('./common.js'); obj.servers4 = {}; obj.servers6 = {}; obj.mainTimer = null; const periodicScanTime = (60000 * 20); // Interval between scans, 20 minutes. const membershipIPv4 = '239.255.255.235'; const membershipIPv6 = 'FF02:0:0:0:0:0:0:FE'; obj.agentCertificateHashHex = parent.certificateOperations.forge.pki.getPublicKeyFingerprint(parent.certificateOperations.forge.pki.certificateFromPem(parent.certificates.agent.cert).publicKey, { md: parent.certificateOperations.forge.md.sha384.create(), encoding: 'hex' }).toUpperCase(); obj.error = 0; obj.pendingOutboundPackets = []; obj.pendingOutboundTimer = null; // Setup the multicast key if present if ((typeof obj.parent.args.localdiscovery == 'object') && (typeof obj.parent.args.localdiscovery.key == 'string') && (obj.parent.args.localdiscovery.key.length > 0)) { obj.multicastKey = parent.crypto.createHash('sha384').update(obj.parent.args.localdiscovery.key).digest('raw').slice(0, 32); } // Encrypt UDP packet function encryptPacket(plainPacket) { if (obj.multicastKey == null) { return plainPacket; } const iv = parent.crypto.randomBytes(16), aes = parent.crypto.createCipheriv('aes-256-cbc', obj.multicastKey, iv); var ciphertext = aes.update(plainPacket); return Buffer.concat([iv, ciphertext, aes.final()]); } // Decrypt UDP packet function decryptPacket(packet) { if (obj.multicastKey == null) { return packet; } if (packet.length < 17) { return null; } try { const iv = packet.slice(0, 16), data = packet.slice(16); const aes = parent.crypto.createDecipheriv('aes-256-cbc', obj.multicastKey, iv); var plaintextBytes = Buffer.from(aes.update(data)); return Buffer.concat([plaintextBytes, aes.final()]); } catch (ex) { return null; } } // Get a list of IPv4 and IPv6 interface addresses function getInterfaceList() { var i; var ipv4 = ['*'], ipv6 = ['*']; // Bind to IN_ADDR_ANY always var interfaces = require('os').networkInterfaces(); for (i in interfaces) { var xinterface = interfaces[i]; for (var j in xinterface) { var interface2 = xinterface[j]; if ((interface2.mac != '00:00:00:00:00:00') && (interface2.internal == false)) { if (interface2.family == 'IPv4') { ipv4.push(interface2.address); } if (interface2.family == 'IPv6') { ipv6.push(interface2.address + '%' + i); } } } } return { ipv4: ipv4, ipv6: ipv6 }; } // Setup all IPv4 and IPv6 servers function setupServers() { var addresses = getInterfaceList(), i, localAddress, bindOptions; for (i in obj.servers4) { obj.servers4[i].xxclear = true; } for (i in obj.servers6) { obj.servers6[i].xxclear = true; } for (i in addresses.ipv4) { localAddress = addresses.ipv4[i]; if (obj.servers4[localAddress] != null) { // Server already exists obj.servers4[localAddress].xxclear = false; } else { // Create a new IPv4 server try { var server4 = obj.dgram.createSocket({ type: 'udp4', reuseAddr: true }); server4.xxclear = false; server4.xxtype = 4; server4.xxlocal = localAddress; server4.on('error', function (err) { /*if (this.xxlocal == '*') { console.log("ERROR: Server port 16989 not available, check if server is running twice."); } this.close(); delete obj.servers6[this.xxlocal];*/ }); bindOptions = { port: 16989, exclusive: true }; if (server4.xxlocal != '*') { bindOptions.address = server4.xxlocal; } server4.bind(bindOptions, function () { try { var doscan = true; try { this.setBroadcast(true); this.setMulticastTTL(128); this.addMembership(membershipIPv4, this.xxlocal); } catch (e) { doscan = false; } this.on('error', function (error) { /*console.log('Error: ' + error);*/ }); this.on('message', function (msg, info) { onUdpPacket(msg, info, this); }); if (doscan == true) { obj.performScan(this); obj.performScan(this); } } catch (e) { console.log(e); } }); obj.servers4[localAddress] = server4; } catch (e) { console.log(e); } } } for (i in addresses.ipv6) { localAddress = addresses.ipv6[i]; if (obj.servers6[localAddress] != null) { // Server already exists obj.servers6[localAddress].xxclear = false; } else { // Create a new IPv6 server try { var server6 = obj.dgram.createSocket({ type: 'udp6', reuseAddr: true }); server6.xxclear = false; server6.xxtype = 6; server6.xxlocal = localAddress; server6.on('error', function (err) { /*this.close(); delete obj.servers6[this.xxlocal];*/ }); bindOptions = { port: 16989, exclusive: true }; if (server6.xxlocal != '*') { bindOptions.address = server6.xxlocal; } server6.bind(bindOptions, function () { try { var doscan = true; try { this.setBroadcast(true); this.setMulticastTTL(128); this.addMembership(membershipIPv6, this.xxlocal); } catch (e) { doscan = false; } this.on('error', function (error) { console.log('Error: ' + error); }); this.on('message', function (msg, info) { onUdpPacket(msg, info, this); }); if (doscan == true) { obj.performScan(this); obj.performScan(this); } } catch (e) { console.log(e); } }); obj.servers6[localAddress] = server6; } catch (e) { console.log(e); } } } for (i in obj.servers4) { if (obj.servers4[i].xxclear == true) { obj.servers4[i].close(); delete obj.servers4[i]; } } for (i in obj.servers6) { if (obj.servers6[i].xxclear == true) { obj.servers6[i].close(); delete obj.servers6[i]; } } } // Clear all IPv4 and IPv6 servers function clearServers() { var i; for (i in obj.servers4) { obj.servers4[i].close(); delete obj.servers4[i]; } for (i in obj.servers6) { obj.servers6[i].close(); delete obj.servers6[i]; } } // Start scanning for local network Mesh Agents obj.start = function () { if (obj.server4 != null) return; // Setup the local discovery values var name = 'MeshCentral'; var info = ''; try { if ((typeof obj.parent.config.domains[''].title == 'string') && (obj.parent.config.domains[''].title.length > 0)) { name = obj.parent.config.domains[''].title; info = ''; try { if ((typeof obj.parent.config.domains[''].title2 == 'string') && (obj.parent.config.domains[''].title2.length > 0)) { info = obj.parent.config.domains[''].title2; } } catch (ex) { } } } catch (ex) { } try { if ((typeof obj.parent.args.localdiscovery.name == 'string') && (obj.parent.args.localdiscovery.name.length > 0)) { name = obj.parent.args.localdiscovery.name; info = ''; try { if ((typeof obj.parent.args.localdiscovery.info == 'string') && (obj.parent.args.localdiscovery.info.length > 0)) { info = obj.parent.args.localdiscovery.info; } } catch (ex) { } } } catch (ex) { } if (info == '') { info = parent.certificates.CommonName; } // Figure out the correct websocket port var port = (parent.args.aliasport)?parent.args.aliasport:parent.args.port; // Build the IPv4 response var url = 'wss://%s:' + port + '/agent.ashx'; obj.multicastPacket4 = Buffer.from("MeshCentral2|" + obj.agentCertificateHashHex + '|' + url, 'ascii'); if (parent.certificates.CommonName.indexOf('.') != -1) { url = 'wss://' + parent.certificates.CommonName + ':' + port + '/agent.ashx'; } obj.multicastPacket4x = Buffer.from("MeshCentral2|" + obj.agentCertificateHashHex + '|' + url + '|' + name + '|' + info, 'ascii'); // Build the IPv6 response url = 'wss://[%s]:' + port + '/agent.ashx'; obj.multicastPacket6 = Buffer.from("MeshCentral2|" + obj.agentCertificateHashHex + '|' + url, 'ascii'); if (parent.certificates.CommonName.indexOf('.') != -1) { url = 'wss://' + parent.certificates.CommonName + ':' + port + '/agent.ashx'; } obj.multicastPacket6x = Buffer.from("MeshCentral2|" + obj.agentCertificateHashHex + '|' + url + '|' + name + '|' + info, 'ascii'); setupServers(); obj.mainTimer = setInterval(obj.performScan, periodicScanTime); return obj; }; // Stop scanning for local network Mesh Agents obj.stop = function () { if (obj.mainTimer != null) { clearInterval(obj.mainTimer); obj.mainTimer = null; } clearServers(); }; // Look for all Mesh Agents that may be locally reachable, indicating the presense of this server. obj.performScan = function (server) { var i; if (server != null) { if (server.xxtype == 4) { var p = encryptPacket(obj.multicastPacket4); try { server.send(p, 0, p.length, 16990, membershipIPv4); } catch (e) { } } if (server.xxtype == 6) { var p = encryptPacket(obj.multicastPacket6); try { server.send(p, 0, p.length, 16990, membershipIPv6); } catch (e) { } } if ((server.xxtype == 4) && (server.xxlocal == '*')) { var p = encryptPacket(obj.multicastPacket4); try { server.send(p, 0, p.length, 16990, '127.0.0.1'); } catch (e) { } try { server.send(p, 0, p.length, 16990, '255.255.255.255'); } catch (e) { } } if ((server.xxtype == 6) && (server.xxlocal == '*')) { var p = encryptPacket(obj.multicastPacket6); try { server.send(p, 0, p.length, 16990, '::1'); } catch (e) { } } } else { for (i in obj.servers4) { var p = encryptPacket(obj.multicastPacket4); try { obj.servers4[i].send(p, 0, p.length, 16990, membershipIPv4); } catch (e) { } } for (i in obj.servers6) { var p = encryptPacket(obj.multicastPacket6); try { obj.servers6[i].send(p, 0, p.length, 16990, membershipIPv6); } catch (e) { } } setupServers(); // Check if any network interfaces where added or removed } }; // Called when a UDP packet is received from an agent. function onUdpPacket(msg, info, server) { // Decrypt the packet if needed if ((msg = decryptPacket(msg)) == null) return; //console.log('Received ' + msg.length + ' bytes from ' + info.address + ':' + info.port + ', on interface: ' + server.xxlocal + '.'); if ((msg.length == 96) && (msg.toString('ascii') == obj.agentCertificateHashHex)) { if (server.xxtype == 4) { var p = encryptPacket(obj.multicastPacket4); try { server.send(p, 0, p.length, info.port, info.address); } catch (e) { } } if (server.xxtype == 6) { var p = encryptPacket(obj.multicastPacket6); try { server.send(p, 0, p.length, info.port, info.address); } catch (e) { } } } else if (msg.toString('ascii') == 'MeshServerScan') { if (server.xxtype == 4) { var p = encryptPacket(obj.multicastPacket4x); try { server.send(p, 0, p.length, info.port, info.address); } catch (e) { } } if (server.xxtype == 6) { var p = encryptPacket(obj.multicastPacket6x); try { server.send(p, 0, p.length, info.port, info.address); } catch (e) { } } } } // Send the next packet in the pending list, stop the timer if we are done. function sendPendingPacket() { if (obj.pendingOutboundPackets.length == 0) { if (obj.pendingOutboundTimer != null) { clearInterval(obj.pendingOutboundTimer); obj.pendingOutboundTimer = null; } return; } var packet = obj.pendingOutboundPackets.shift(); if (packet != null) { packet[0].send(packet[1], 0, packet[1].length, packet[2], packet[3]); } } // As a side job, we also send server wake-on-lan packets obj.wakeOnLan = function (macs, host) { var i, j, futureTime = 0; for (i in macs) { var mac = macs[i].split(':').join(''); var hexpacket = 'FFFFFFFFFFFF'; for (j = 0; j < 16; j++) { hexpacket += mac; } var wakepacket = Buffer.from(hexpacket, 'hex'); // Add all wake packets to the pending list for (var k = 0; k < 5; k++) { for (j in obj.servers4) { obj.pendingOutboundPackets.push([obj.servers4[j], wakepacket, 7, '255.255.255.255']); // IPv4 Broadcast obj.pendingOutboundPackets.push([obj.servers4[j], wakepacket, 16990, membershipIPv4]); // IPv4 Multicast if (host != null) { obj.pendingOutboundPackets.push([obj.servers4[j], wakepacket, 7, host]); } // IPv4 Directed } for (j in obj.servers6) { obj.pendingOutboundPackets.push([obj.servers6[j], wakepacket, 16990, membershipIPv6]); // IPv6 Multicast } } // Send each packet at 10ms interval // This packet spacing is absolutly required, otherwise the outbound buffer gets filled up and packets get lost which often causes the machine not to wake. if (obj.pendingOutboundTimer == null) { obj.pendingOutboundTimer = setInterval(sendPendingPacket, 10); } } }; return obj; };