Add Harbor Gateway auto-detection for client routing

test/server/gateway-presence.test.js

@@ -0,0 +1,109 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+
+import {
+  buildGatewayPresence,
+  createGatewayAutoState,
+  nextGatewayAutoState,
+  probeGatewayPresence,
+  readHostNetworkState,
+  verifyGatewayPresence,
+} from '../../src/server/gatewayPresence.js';
+
+const subscriptionUrl = 'https://subscription.example/0123456789abcdef0123456789abcdef';
+const nonce = '0123456789abcdef0123456789abcdef';
+
+test('Gateway presence is authenticated by the shared subscription secret', async () => {
+  const payload = buildGatewayPresence({
+    appMode: 'gateway',
+    subscriptionUrl,
+    gatewayId: 'gateway-1',
+    nonce,
+  });
+
+  assert.equal(verifyGatewayPresence(payload, { subscriptionUrl, nonce }), true);
+  assert.equal(verifyGatewayPresence(payload, {
+    subscriptionUrl: 'https://subscription.example/fedcba9876543210fedcba9876543210',
+    nonce,
+  }), false);
+
+  const result = await probeGatewayPresence({
+    gateway: '192.168.50.111',
+    subscriptionUrl,
+    nonce,
+    fetchImpl: async (url) => {
+      assert.equal(
+        url,
+        `http://192.168.50.111:3456/api/gateway-presence?nonce=${nonce}`,
+      );
+      return { ok: true, json: async () => payload };
+    },
+  });
+  assert.deepEqual(result, { gatewayId: 'gateway-1' });
+
+  assert.equal(buildGatewayPresence({
+    appMode: 'gateway',
+    subscriptionUrl: 'https://subscription.example/public-feed',
+    gatewayId: 'gateway-1',
+    nonce,
+  }).available, false);
+
+  const sharedPublicValue = 'https://public.example/sing-box-configuration-v1';
+  const firstUrl = `${subscriptionUrl}?redirect=${encodeURIComponent(sharedPublicValue)}`;
+  const secondUrl = `https://subscription.example/fedcba9876543210fedcba9876543210?redirect=${encodeURIComponent(sharedPublicValue)}`;
+  const firstPayload = buildGatewayPresence({
+    appMode: 'gateway',
+    subscriptionUrl: firstUrl,
+    gatewayId: 'gateway-1',
+    nonce,
+  });
+  assert.equal(verifyGatewayPresence(firstPayload, {
+    subscriptionUrl: secondUrl,
+    nonce,
+  }), false);
+});
+
+test('host route freshness and Gateway failures drive a safe automatic fallback', () => {
+  const now = Date.now();
+  const statePath = path.join(fs.mkdtempSync(path.join(os.tmpdir(), 'harbor-route-')), 'network.json');
+  fs.writeFileSync(statePath, JSON.stringify({
+    gateway: '192.168.50.111',
+    interface: 'en0',
+    mac: 'aa:bb:cc:dd:ee:ff',
+    observedAt: new Date(now).toISOString(),
+  }));
+  const network = readHostNetworkState(statePath, { now });
+  assert.equal(network.gateway, '192.168.50.111');
+
+  let state = nextGatewayAutoState(createGatewayAutoState(), {
+    network,
+    verifiedGateway: { gatewayId: 'gateway-1' },
+  });
+  assert.equal(state.mode, 'gateway-direct');
+
+  state = nextGatewayAutoState(state, { network });
+  state = nextGatewayAutoState(state, { network });
+  assert.equal(state.mode, 'gateway-direct');
+  state = nextGatewayAutoState(state, { network });
+  assert.equal(state.mode, 'local-vpn');
+
+  const newNetwork = { ...network, mac: '11:22:33:44:55:66' };
+  state = nextGatewayAutoState(nextGatewayAutoState(createGatewayAutoState(), {
+    network,
+    verifiedGateway: { gatewayId: 'gateway-1' },
+  }), { network: newNetwork });
+  assert.equal(state.mode, 'local-vpn');
+
+  assert.equal(readHostNetworkState(statePath, { now: now + 16_000 }), null);
+
+  fs.writeFileSync(statePath, JSON.stringify({
+    gateway: '192.168.50.111',
+    interface: 'en0',
+    mac: '',
+    observedAt: new Date(now).toISOString(),
+  }));
+  assert.equal(readHostNetworkState(statePath, { now }), null);
+});