balena-supervisor/test/34-firewall.spec.ts

import _ = require('lodash');
import { expect } from 'chai';

import * as Docker from 'dockerode';
import { docker } from '../src/lib/docker-utils';
import * as sinon from 'sinon';

import * as config from '../src/config';
import * as firewall from '../src/lib/firewall';
import * as logger from '../src/logger';
import * as iptablesMock from './lib/mocked-iptables';
import * as targetStateCache from '../src/device-state/target-state-cache';

import constants = require('../src/lib/constants');
import { RuleAction, Rule } from '../src/lib/iptables';
import { log } from '../src/lib/supervisor-console';

describe('Host Firewall', function () {
	const dockerStubs: Dictionary<sinon.SinonStub> = {};
	let loggerSpy: sinon.SinonSpy;
	let logSpy: sinon.SinonSpy;

	let apiEndpoint: string;
	let listenPort: number;

	before(async () => {
		// spy the logs...
		loggerSpy = sinon.spy(logger, 'logSystemMessage');
		logSpy = sinon.spy(log, 'error');

		// stub the docker calls...
		dockerStubs.listContainers = sinon
			.stub(docker, 'listContainers')
			.resolves([]);
		dockerStubs.listImages = sinon.stub(docker, 'listImages').resolves([]);
		dockerStubs.getImage = sinon.stub(docker, 'getImage').returns({
			id: 'abcde',
			inspect: async () => {
				return {};
			},
		} as Docker.Image);

		await targetStateCache.initialized;
		await firewall.initialised;

		apiEndpoint = await config.get('apiEndpoint');
		listenPort = await config.get('listenPort');
	});

	after(async () => {
		for (const stub of _.values(dockerStubs)) {
			stub.restore();
		}
		loggerSpy.restore();
		logSpy.restore();
	});

	describe('Basic On/Off operation', () => {
		it('should confirm the `changed` event is handled', async function () {
			await iptablesMock.whilstMocked(async ({ hasAppliedRules }) => {
				const changedSpy = sinon.spy();
				config.on('change', changedSpy);

				// set the firewall to be in off mode...
				await config.set({ firewallMode: 'off' });
				await hasAppliedRules;

				// check it fired the events correctly...
				expect(changedSpy.called).to.be.true;
				expect(changedSpy.calledWith({ firewallMode: 'off' })).to.be.true;
			});
		});

		it('should handle the HOST_FIREWALL_MODE configuration value: invalid', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the firewall to be in off mode...
					await config.set({ firewallMode: 'invalid' });
					await hasAppliedRules;

					// expect that we jump to the firewall chain...
					expectRule({
						target: 'BALENA-FIREWALL',
						chain: 'INPUT',
						family: 4,
					});

					// expect to return...
					expectRule({
						chain: 'BALENA-FIREWALL',
						target: 'RETURN',
						family: 4,
					});
				},
			);
		});

		it('should respect the HOST_FIREWALL_MODE configuration value: off', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the firewall to be in off mode...
					await config.set({ firewallMode: 'off' });
					await hasAppliedRules;

					// expect that we jump to the firewall chain...
					expectRule({
						action: RuleAction.Append,
						target: 'BALENA-FIREWALL',
						chain: 'INPUT',
						family: 4,
					});

					// expect to return...
					const returnRuleIdx = expectRule({
						table: 'filter',
						chain: 'BALENA-FIREWALL',
						target: 'RETURN',
						family: 4,
					});

					// ... just before we reject everything
					const rejectRuleIdx = expectRule({
						chain: 'BALENA-FIREWALL',
						target: 'REJECT',
						matches: iptablesMock.RuleProperty.NotSet,
						family: 4,
					});

					expect(returnRuleIdx).to.be.lessThan(rejectRuleIdx);
				},
			);
		});

		it('should respect the HOST_FIREWALL_MODE configuration value: on', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule, expectNoRule }) => {
					// set the firewall to be in auto mode...
					await config.set({ firewallMode: 'on' });
					await hasAppliedRules;

					// expect that we jump to the firewall chain...
					expectRule({
						action: RuleAction.Append,
						target: 'BALENA-FIREWALL',
						chain: 'INPUT',
						family: 4,
					});

					// expect to not return for any reason...
					expectNoRule({
						chain: 'BALENA-FIREWALL',
						target: 'RETURN',
					});
				},
			);
		});

		it('should respect the HOST_FIREWALL_MODE configuration value: auto (no services in host-network)', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					await targetStateCache.setTargetApps([
						{
							appId: 2,
							commit: 'abcdef2',
							name: 'test-app2',
							source: apiEndpoint,
							releaseId: 1232,
							services: JSON.stringify([
								{
									serviceName: 'test-service',
									image: 'test-image',
									imageId: 5,
									environment: {
										TEST_VAR: 'test-string',
									},
									tty: true,
									appId: 2,
									releaseId: 1232,
									serviceId: 567,
									commit: 'abcdef2',
								},
							]),
							networks: '[]',
							volumes: '[]',
						},
					]);

					// set the firewall to be in auto mode...
					await config.set({ firewallMode: 'auto' });
					await hasAppliedRules;

					// expect that we jump to the firewall chain...
					expectRule({
						action: RuleAction.Append,
						target: 'BALENA-FIREWALL',
						chain: 'INPUT',
						family: 4,
					});

					// expect to return...
					expectRule({
						chain: 'BALENA-FIREWALL',
						target: 'RETURN',
						family: 4,
					});
				},
			);
		});

		it('should respect the HOST_FIREWALL_MODE configuration value: auto (service in host-network)', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule, expectNoRule }) => {
					await targetStateCache.setTargetApps([
						{
							appId: 2,
							commit: 'abcdef2',
							name: 'test-app2',
							source: apiEndpoint,
							releaseId: 1232,
							services: JSON.stringify([
								{
									serviceName: 'test-service',
									networkMode: 'host',
									image: 'test-image',
									imageId: 5,
									environment: {
										TEST_VAR: 'test-string',
									},
									tty: true,
									appId: 2,
									releaseId: 1232,
									serviceId: 567,
									commit: 'abcdef2',
								},
							]),
							networks: '[]',
							volumes: '[]',
						},
					]);

					// set the firewall to be in auto mode...
					await config.set({ firewallMode: 'auto' });
					await hasAppliedRules;

					// expect that we jump to the firewall chain...
					expectRule({
						action: RuleAction.Append,
						target: 'BALENA-FIREWALL',
						chain: 'INPUT',
						family: 4,
					});

					// expect to return...
					expectNoRule({
						chain: 'BALENA-FIREWALL',
						target: 'RETURN',
						family: 4,
					});
				},
			);
		});

		it('should catch errors when rule changes fail', async () => {
			await iptablesMock.whilstMocked(async ({ hasAppliedRules }) => {
				// clear the spies...
				loggerSpy.resetHistory();
				logSpy.resetHistory();

				// set the firewall to be in off mode...
				await config.set({ firewallMode: 'off' });
				await hasAppliedRules;

				// should have caught the error and logged it
				expect(logSpy.calledWith('Error applying firewall mode')).to.be.true;
				expect(loggerSpy.called).to.be.true;
			}, iptablesMock.realRuleAdaptor);
		});
	});

	describe('Service rules', () => {
		const rejectAllRule = {
			target: 'REJECT',
			chain: 'BALENA-FIREWALL',
			matches: iptablesMock.RuleProperty.NotSet,
		};

		const checkForRules = (
			rules: Array<iptablesMock.Testable<Rule>> | iptablesMock.Testable<Rule>,
			expectRule: (rule: iptablesMock.Testable<Rule>) => number,
		) => {
			rules = _.castArray(rules);
			rules.forEach((rule) => {
				const ruleIdx = expectRule(rule);

				// make sure we reject AFTER the rule...
				const rejectAllRuleIdx = expectRule(rejectAllRule);
				expect(ruleIdx).is.lessThan(rejectAllRuleIdx);
			});
		};

		it('should have a rule to allow DNS traffic from the balena0 interface', async () => {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the firewall to be on...
					await config.set({ firewallMode: 'on' });
					await hasAppliedRules;

					[4, 6].forEach((family: 4 | 6) => {
						// expect that we have a rule to allow DNS access...
						checkForRules(
							{
								family,
								target: 'ACCEPT',
								chain: 'BALENA-FIREWALL',
								proto: 'udp',
								matches: ['--dport 53', '-i balena0'],
							},
							expectRule,
						);
					});
				},
			);
		});

		it('should have a rule to allow SSH traffic any interface', async () => {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the firewall to be on...
					await config.set({ firewallMode: 'on' });
					await hasAppliedRules;

					[4, 6].forEach((family: 4 | 6) => {
						// expect that we have a rule to allow SSH access...
						checkForRules(
							{
								family,
								target: 'ACCEPT',
								chain: 'BALENA-FIREWALL',
								proto: 'tcp',
								matches: ['--dport 22222'],
							},
							expectRule,
						);
					});
				},
			);
		});

		it('should have a rule to allow Multicast traffic any interface', async () => {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the firewall to be on...
					await config.set({ firewallMode: 'on' });
					await hasAppliedRules;

					[4, 6].forEach((family: 4 | 6) => {
						// expect that we have a rule to allow multicast...
						checkForRules(
							{
								family,
								target: 'ACCEPT',
								chain: 'BALENA-FIREWALL',
								matches: ['-m addrtype', '--dst-type MULTICAST'],
							},
							expectRule,
						);
					});
				},
			);
		});

		it('should have a rule to allow balenaEngine traffic any interface', async () => {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the firewall to be on...
					await config.set({ firewallMode: 'on' });
					await hasAppliedRules;

					[4, 6].forEach((family: 4 | 6) => {
						// expect that we have a rule to allow balenaEngine access...
						checkForRules(
							{
								family,
								target: 'ACCEPT',
								chain: 'BALENA-FIREWALL',
								proto: 'tcp',
								matches: ['--dport 2375'],
							},
							expectRule,
						);
					});
				},
			);
		});
	});

	describe('Supervisor API access', () => {
		it('should allow access in localmode', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule }) => {
					// set the device to be in local mode...
					await config.set({ localMode: true });
					await hasAppliedRules;

					[4, 6].forEach((family: 4 | 6) => {
						// make sure we have a rule to allow traffic on ANY interface
						const allowRuleIdx = expectRule({
							proto: 'tcp',
							matches: [`--dport ${listenPort}`],
							target: 'ACCEPT',
							chain: 'BALENA-FIREWALL',
							table: 'filter',
							family,
						});

						// make sure we have a rule to block traffic on ANY interface also
						const rejectRuleIdx = expectRule({
							proto: 'tcp',
							matches: [`--dport ${listenPort}`],
							target: 'REJECT',
							chain: 'BALENA-FIREWALL',
							table: 'filter',
							family,
						});

						// we should always reject AFTER we allow
						expect(allowRuleIdx).to.be.lessThan(rejectRuleIdx);
					});
				},
			);
		});

		it('should allow limited access in non-localmode', async function () {
			await iptablesMock.whilstMocked(
				async ({ hasAppliedRules, expectRule, expectNoRule }) => {
					// set the device to be in local mode...
					await config.set({ localMode: false });
					await hasAppliedRules;

					// ensure we have no unrestricted rule...
					expectNoRule({
						chain: 'BALENA-FIREWALL',
						proto: 'tcp',
						matches: [`--dport ${listenPort}`],
						target: 'ACCEPT',
						family: 4,
					});

					// ensure we do have a restricted rule for each interface...
					let allowRuleIdx = -1;
					constants.allowedInterfaces.forEach((intf) => {
						[4, 6].forEach((family: 4 | 6) => {
							allowRuleIdx = expectRule({
								chain: 'BALENA-FIREWALL',
								proto: 'tcp',
								matches: [`--dport ${listenPort}`, `-i ${intf}`],
								target: 'ACCEPT',
								family,
							});
						});
					});

					// make sure we have a rule to block traffic on ANY interface also
					const rejectRuleIdx = expectRule({
						proto: 'tcp',
						matches: [`--dport ${listenPort}`],
						target: 'REJECT',
						chain: 'BALENA-FIREWALL',
						table: 'filter',
					});

					// we should always reject AFTER we allow
					expect(allowRuleIdx).to.be.lessThan(rejectRuleIdx);
				},
			);
		});
	});
});