feat(udp,http3): add UDP datagram handler relay support and stream HTTP/3 request bodies to backends

test/test.udp-forwarding.ts

@@ -0,0 +1,142 @@
+import { expect, tap } from '@git.zone/tstest/tapbundle';
+import * as dgram from 'dgram';
+import { SmartProxy } from '../ts/index.js';
+import { findFreePorts, assertPortsFree } from './helpers/port-allocator.js';
+
+let smartProxy: SmartProxy;
+let backendServer: dgram.Socket;
+let PROXY_PORT: number;
+let BACKEND_PORT: number;
+
+// Helper: send a single UDP datagram and wait for a response
+function sendDatagram(port: number, msg: string, timeoutMs = 5000): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const client = dgram.createSocket('udp4');
+    const timeout = setTimeout(() => {
+      client.close();
+      reject(new Error(`UDP response timeout after ${timeoutMs}ms`));
+    }, timeoutMs);
+    client.send(Buffer.from(msg), port, '127.0.0.1');
+    client.on('message', (data) => {
+      clearTimeout(timeout);
+      client.close();
+      resolve(data.toString());
+    });
+    client.on('error', (err) => {
+      clearTimeout(timeout);
+      client.close();
+      reject(err);
+    });
+  });
+}
+
+// Helper: create a UDP echo server
+function createUdpEchoServer(port: number): Promise<dgram.Socket> {
+  return new Promise((resolve) => {
+    const server = dgram.createSocket('udp4');
+    server.on('message', (msg, rinfo) => {
+      server.send(Buffer.from(`Echo: ${msg.toString()}`), rinfo.port, rinfo.address);
+    });
+    server.bind(port, '127.0.0.1', () => resolve(server));
+  });
+}
+
+tap.test('setup: start UDP echo server and SmartProxy', async () => {
+  [PROXY_PORT, BACKEND_PORT] = await findFreePorts(2);
+
+  // Start backend UDP echo server
+  backendServer = await createUdpEchoServer(BACKEND_PORT);
+
+  // Start SmartProxy with a UDP forwarding route
+  smartProxy = new SmartProxy({
+    routes: [
+      {
+        name: 'udp-forward-test',
+        match: {
+          ports: PROXY_PORT,
+          transport: 'udp' as const,
+        },
+        action: {
+          type: 'forward',
+          targets: [{ host: '127.0.0.1', port: BACKEND_PORT }],
+          udp: {
+            sessionTimeout: 5000,
+          },
+        },
+      },
+    ],
+    defaults: {
+      security: {
+        ipAllowList: ['127.0.0.1', '::1', '::ffff:127.0.0.1'],
+      },
+    },
+  });
+
+  await smartProxy.start();
+});
+
+tap.test('UDP forwarding: basic datagram round-trip', async () => {
+  const response = await sendDatagram(PROXY_PORT, 'Hello UDP');
+  expect(response).toEqual('Echo: Hello UDP');
+});
+
+tap.test('UDP forwarding: multiple datagrams same session', async () => {
+  // Use a single client socket for session reuse
+  const client = dgram.createSocket('udp4');
+  const responses: string[] = [];
+
+  const done = new Promise<void>((resolve, reject) => {
+    const timeout = setTimeout(() => {
+      client.close();
+      reject(new Error('Timeout waiting for 3 responses'));
+    }, 5000);
+
+    client.on('message', (data) => {
+      responses.push(data.toString());
+      if (responses.length === 3) {
+        clearTimeout(timeout);
+        client.close();
+        resolve();
+      }
+    });
+    client.on('error', (err) => {
+      clearTimeout(timeout);
+      client.close();
+      reject(err);
+    });
+  });
+
+  client.send(Buffer.from('msg1'), PROXY_PORT, '127.0.0.1');
+  client.send(Buffer.from('msg2'), PROXY_PORT, '127.0.0.1');
+  client.send(Buffer.from('msg3'), PROXY_PORT, '127.0.0.1');
+
+  await done;
+
+  expect(responses).toContain('Echo: msg1');
+  expect(responses).toContain('Echo: msg2');
+  expect(responses).toContain('Echo: msg3');
+});
+
+tap.test('UDP forwarding: multiple clients', async () => {
+  const [resp1, resp2] = await Promise.all([
+    sendDatagram(PROXY_PORT, 'client1'),
+    sendDatagram(PROXY_PORT, 'client2'),
+  ]);
+
+  expect(resp1).toEqual('Echo: client1');
+  expect(resp2).toEqual('Echo: client2');
+});
+
+tap.test('UDP forwarding: large datagram (1400 bytes)', async () => {
+  const payload = 'X'.repeat(1400);
+  const response = await sendDatagram(PROXY_PORT, payload);
+  expect(response).toEqual(`Echo: ${payload}`);
+});
+
+tap.test('cleanup: stop SmartProxy and backend', async () => {
+  await smartProxy.stop();
+  await new Promise<void>((resolve) => backendServer.close(() => resolve()));
+  await assertPortsFree([PROXY_PORT, BACKEND_PORT]);
+});
+
+export default tap.start();