state: Report device MAC address to the API

When reporting device information, send the MAC address of any
interfaces on the system. Also expose in the Supervisor API at
the route GET /v1/device.

Change-type: patch
Signed-off-by: Rich Bayliss <rich@balena.io>

docs/API.md

@@ -327,6 +327,7 @@ The state is a JSON object that contains some or all of the following:
 * `api_port`: Port on which the supervisor is listening.
 * `commit`: Hash of the current commit of the application that is running.
 * `ip_address`: Space-separated list of IP addresses of the device.
+* `mac_address`: Space-seperated list of MAC addresses of the device.
 * `status`: Status of the device regarding the app, as a string, i.e. "Stopping", "Starting", "Downloading", "Installing", "Idle".
 * `download_progress`: Amount of the application image that has been downloaded, expressed as a percentage. If the update has already been downloaded, this will be `null`.
 * `os_version`: Version of the host OS running on the device.
@@ -1243,4 +1244,4 @@ $ curl -X POST -H "Content-Type: application/json" --data '{"follow":true,"all":
 ```
 
 An example project using this endpoint can be found
-[in this repository](https://github.com/balena-io-playground/device-cloud-logging).
+[in this repository](https://github.com/balena-io-playground/device-cloud-logging).

src/config/functions.ts

@@ -8,6 +8,7 @@ import supervisorVersion = require('../lib/supervisor-version');
 import * as config from '.';
 import * as constants from '../lib/constants';
 import * as osRelease from '../lib/os-release';
+import * as macAddress from '../lib/mac-address';
 import log from '../lib/supervisor-console';
 
 export const fnSchema = {
@@ -34,6 +35,9 @@ export const fnSchema = {
 	osVariant: () => {
 		return osRelease.getOSVariant(constants.hostOSVersionPath);
 	},
+	macAddress: () => {
+		return macAddress.getAll(constants.macAddressPath);
+	},
 	deviceArch: async () => {
 		try {
 			// FIXME: We should be mounting the following file into the supervisor from the

src/config/schema-type.ts

@@ -192,6 +192,10 @@ export const schemaTypes = {
 		type: t.union([t.string, NullOrUndefined]),
 		default: t.never,
 	},
+	macAddress: {
+		type: t.union([t.string, NullOrUndefined]),
+		default: t.never,
+	},
 	provisioningOptions: {
 		type: t.interface({
 			// These types are taken from the types of the individual

src/device-state.ts

@@ -143,6 +143,7 @@ function createDeviceStateRouter(deviceState: DeviceState) {
 				'api_port',
 				'ip_address',
 				'os_version',
+				'mac_address',
 				'supervisor_version',
 				'update_pending',
 				'update_failed',
@@ -315,6 +316,7 @@ export class DeviceState extends (EventEmitter as new () => DeviceStateEventEmit
 			'apiSecret',
 			'osVersion',
 			'osVariant',
+			'macAddress',
 			'version',
 			'provisioned',
 			'apiEndpoint',
@@ -339,6 +341,7 @@ export class DeviceState extends (EventEmitter as new () => DeviceStateEventEmit
 			api_secret: conf.apiSecret,
 			os_version: conf.osVersion,
 			os_variant: conf.osVariant,
+			mac_address: conf.macAddress,
 			supervisor_version: conf.version,
 			provisioning_progress: null,
 			provisioning_state: '',
@@ -393,8 +396,10 @@ export class DeviceState extends (EventEmitter as new () => DeviceStateEventEmit
 		log.debug('Starting periodic check for IP addresses');
 
 		await network.startIPAddressUpdate()(async (addresses) => {
+			const macAddress = await config.get('macAddress');
 			await this.reportCurrentState({
 				ip_address: addresses.join(' '),
+				mac_address: macAddress,
 			});
 		}, constants.ipAddressUpdateInterval);
 	}

src/lib/constants.ts

@@ -21,6 +21,9 @@ const constants = {
 	hostOSVersionPath:
 		checkString(process.env.HOST_OS_VERSION_PATH) ||
 		`${rootMountPoint}/etc/os-release`,
+	macAddressPath:
+		checkString(process.env.MAC_ADDRESS_PATH) ||
+		`${rootMountPoint}/sys/class/net`,
 	privateAppEnvVars: [
 		'RESIN_SUPERVISOR_API_KEY',
 		'RESIN_API_KEY',

src/lib/mac-address.ts

@@ -0,0 +1,57 @@
+import * as _ from 'lodash';
+import { promises as fs, exists } from 'mz/fs';
+import * as path from 'path';
+
+import log from './supervisor-console';
+import { shouldReportInterface } from '../network';
+
+import TypedError = require('typed-error');
+export class MacAddressError extends TypedError {}
+
+export async function getAll(sysClassNet: string): Promise<string | undefined> {
+	try {
+		// read the directories in the sysfs...
+		const interfaces = await fs.readdir(sysClassNet);
+
+		return _(
+			await Promise.all(
+				interfaces.map(async (intf) => {
+					try {
+						const [addressFile, typeFile, masterFile] = [
+							'address',
+							'type',
+							'master',
+						].map((f) => path.join(sysClassNet, intf, f));
+
+						const [intfType, intfHasMaster] = await Promise.all([
+							fs.readFile(typeFile, 'utf8'),
+							exists(masterFile),
+						]);
+
+						// check if we should report this interface at all, or if it is physical interface, or if the interface has a master interface (i.e. it's not the root interface)
+						if (
+							!shouldReportInterface(intf) ||
+							intfType.trim() !== '1' ||
+							intfHasMaster
+						) {
+							// we shouldn't report this MAC address
+							return '';
+						}
+
+						const addr = await fs.readFile(addressFile, 'utf8');
+						return addr.split('\n')[0]?.trim()?.toUpperCase() ?? '';
+					} catch (err) {
+						log.warn('Error reading MAC address for interface', intf, err);
+						return '';
+					}
+				}),
+			),
+		)
+			.filter((addr) => addr !== '')
+			.uniq()
+			.join(' ');
+	} catch (err) {
+		log.error(new MacAddressError(`Unable to acquire MAC address: ${err}`));
+		return;
+	}
+}

src/network.ts

@@ -115,6 +115,9 @@ export const connectivityCheckEnabled = Bluebird.method(
 );
 
 const IP_REGEX = /^(?:balena|docker|rce|tun)[0-9]+|tun[0-9]+|resin-vpn|lo|resin-dns|supervisor0|balena-redsocks|resin-redsocks|br-[0-9a-f]{12}$/;
+
+export const shouldReportInterface = (intf: string) => !IP_REGEX.test(intf);
+
 export function getIPAddresses(): string[] {
 	// We get IP addresses but ignore:
 	// - docker and balena bridges (docker0, docker1, balena0, etc)
@@ -126,10 +129,12 @@ export function getIPAddresses(): string[] {
 	// - the docker network for the supervisor API (supervisor0)
 	// - custom docker network bridges (br- + 12 hex characters)
 	return _(os.networkInterfaces())
-		.omitBy((_interfaceFields, interfaceName) => IP_REGEX.test(interfaceName))
+		.filter((_interfaceFields, interfaceName) =>
+			shouldReportInterface(interfaceName),
+		)
 		.flatMap((validInterfaces) => {
 			return _(validInterfaces)
-				.pickBy({ family: 'IPv4' })
+				.pickBy({ family: 'IPv4', internal: false })
 				.map('address')
 				.value();
 		})

src/types/state.ts

@@ -21,6 +21,7 @@ export type DeviceReportFields = Partial<{
 	update_downloaded: boolean;
 	is_on__commit: string;
 	logs_channel: null;
+	mac_address: string | null;
 }>;
 
 export interface DeviceStatus {

test/18-startup.spec.ts

@@ -7,9 +7,11 @@ import * as constants from '../src/lib/constants';
 import { docker } from '../src/lib/docker-utils';
 import { Supervisor } from '../src/supervisor';
 import { expect } from './lib/chai-config';
+import _ = require('lodash');
 
 describe('Startup', () => {
 	let initClientStub: SinonStub;
+	let reportCurrentStateStub: SinonStub;
 	let startStub: SinonStub;
 	let vpnStatusPathStub: SinonStub;
 	let appManagerStub: SinonStub;
@@ -20,6 +22,10 @@ describe('Startup', () => {
 		initClientStub = stub(APIBinder.prototype as any, 'initClient').returns(
 			Promise.resolve(),
 		);
+		reportCurrentStateStub = stub(
+			DeviceState.prototype as any,
+			'reportCurrentState',
+		).resolves();
 		startStub = stub(APIBinder.prototype as any, 'start').returns(
 			Promise.resolve(),
 		);
@@ -40,6 +46,7 @@ describe('Startup', () => {
 		vpnStatusPathStub.restore();
 		deviceStateStub.restore();
 		dockerStub.restore();
+		reportCurrentStateStub.restore();
 	});
 
 	it('should startup correctly', async () => {
@@ -52,5 +59,20 @@ describe('Startup', () => {
 		expect(anySupervisor.logger).to.not.be.null;
 		expect(anySupervisor.deviceState).to.not.be.null;
 		expect(anySupervisor.apiBinder).to.not.be.null;
+
+		let macAddresses: string[] = [];
+		reportCurrentStateStub.getCalls().forEach((call) => {
+			const m: string = call.args[0]['mac_address'];
+			if (!m) {
+				return;
+			}
+
+			macAddresses = _.union(macAddresses, m.split(' '));
+		});
+
+		const allMacAddresses = macAddresses.join(' ');
+
+		expect(allMacAddresses).to.have.length.greaterThan(0);
+		expect(allMacAddresses).to.not.contain('NO:');
 	});
 });

test/21-supervisor-api.spec.ts

@@ -113,6 +113,17 @@ describe('SupervisorAPI', () => {
 			});
 		});
 		// TODO: add tests for V1 endpoints
+		describe('GET /v1/device', () => {
+			it('returns MAC address', async () => {
+				const response = await request
+					.get('/v1/device')
+					.set('Accept', 'application/json')
+					.set('Authorization', `Bearer ${VALID_SECRET}`)
+					.expect(200);
+
+				expect(response.body).to.have.property('mac_address').that.is.not.empty;
+			});
+		});
 	});
 
 	describe('V2 endpoints', () => {

test/data/sys/class/net/balena0/address

@@ -0,0 +1 @@
+NO:NO:NO:NO:NO:NO

test/data/sys/class/net/balena0/type

@@ -0,0 +1 @@
+1

test/data/sys/class/net/enp0s3/address

@@ -0,0 +1 @@
+00:11:22:33:44:55

test/data/sys/class/net/enp0s3/type

@@ -0,0 +1 @@
+1

test/data/sys/class/net/enp0s4/address

@@ -0,0 +1 @@
+66:77:88:99:AA:BB

test/data/sys/class/net/enp0s4/type

@@ -0,0 +1 @@
+1

test/data/sys/class/net/master0/address

@@ -0,0 +1 @@
+NO:NO:NO:NO:NO:NO

test/data/sys/class/net/master0/type

@@ -0,0 +1 @@
+1

test/data/sys/class/net/sit0/address

@@ -0,0 +1 @@
+NO:NO:NO:NO:NO:NO

test/data/sys/class/net/sit0/type

@@ -0,0 +1 @@
+2

test/lib/mocked-device-api.ts

@@ -75,9 +75,15 @@ async function create(): Promise<SupervisorAPI> {
 	});
 	// Create SupervisorAPI
 	const api = new SupervisorAPI({
-		routers: [buildRoutes(appManager)],
+		routers: [deviceState.router, buildRoutes(appManager)],
 		healthchecks: [deviceState.healthcheck, apiBinder.healthcheck],
 	});
+
+	const macAddress = await config.get('macAddress');
+	deviceState.reportCurrentState({
+		mac_address: macAddress,
+	});
+
 	// Return SupervisorAPI that is not listening yet
 	return api;
 }