api: move itunnel handlers to separate file

api/src/core/itunnel.js

@@ -0,0 +1,61 @@
+import stream from "../stream/stream.js";
+import { getInternalTunnel } from "../stream/manage.js";
+import { setTunnelPort } from "../config.js";
+import { Green } from "../misc/console-text.js";
+import express from "express";
+
+const validateTunnel = (req, res) => {
+    if (!req.ip.endsWith('127.0.0.1')) {
+        res.sendStatus(403);
+        return;
+    }
+
+    if (String(req.query.id).length !== 21) {
+        res.sendStatus(400);
+        return;
+    }
+
+    const streamInfo = getInternalTunnel(req.query.id);
+    if (!streamInfo) {
+        res.sendStatus(404);
+        return;
+    }
+
+    return streamInfo;
+}
+
+const streamTunnel = (req, res) => {
+    const streamInfo = validateTunnel(req, res);
+    if (!streamInfo) {
+        return;
+    }
+
+    streamInfo.headers = new Map([
+        ...(streamInfo.headers || []),
+        ...Object.entries(req.headers)
+    ]);
+
+    return stream(res, { type: 'internal', ...streamInfo });
+}
+
+export const setupTunnelHandler = () => {
+    const tunnelHandler = express();
+
+    tunnelHandler.get('/itunnel', streamTunnel);
+
+    // fallback
+    tunnelHandler.use((_, res) => res.sendStatus(400));
+    // error handler
+    tunnelHandler.use((_, __, res, ____) => res.socket.end());
+
+
+    const server = tunnelHandler.listen({
+        port: 0,
+        host: '127.0.0.1',
+        exclusive: true
+    }, () => {
+        const { port } = server.address();
+        console.log(`${Green('[✓]')} internal tunnel handler running on 127.0.0.1:${port}`);
+        setTunnelPort(port);
+    });
+}