feat: Add first poc

package.json

@@ -4,9 +4,12 @@
     "dev": "bun run --hot src/index.ts"
   },
   "dependencies": {
-    "hono": "^4.6.9"
+    "hono": "^4.6.9",
+    "id": "^0.0.0",
+    "zod": "^3.23.8"
   },
   "devDependencies": {
-    "@types/bun": "latest"
+    "@types/bun": "latest",
+    "@types/ip": "^1.1.3"
   }
 }

src/index.ts

@@ -1,9 +1,19 @@
 import { Hono } from 'hono'
+import {getConnInfo} from "hono/bun"
+import connectToAddress from './utils/connect-to-address'
 
 const app = new Hono()
 
-app.get('/', (c) => {
-  return c.text('Hello Hono!')
+app.get('/:port', async context => {
+  const port = Number(context.req.param("port"))
+  const info = getConnInfo(context)
+  const ipAddress = info.remote.address!
+
+  const result = await connectToAddress(ipAddress, port)
+
+  return context.json({
+    isOpen: result.isOpen
+  })
 })
 
 export default app

src/routes/port.ts

@@ -0,0 +1,33 @@
+import { Hono } from "hono";
+import { getConnInfo } from "hono/bun";
+import connectToAddress from "../utils/connect-to-address";
+import { z } from "zod";
+import * as IP from "ip"
+
+export const portRoute = new Hono();
+
+const schema = z.object({
+  ip: z.string().refine(ip => !IP.isPublic(ip), "This IP address is not valid"),
+  port: z.coerce.number().min(1).max(2**16 - 1),
+});
+
+portRoute.get("/:port", async context => {
+  const info = getConnInfo(context)
+  const rawData = {
+    ip: info.remote.address || "",
+    port: context.req.param("port"),
+  };
+  const parsedData = schema.safeParse(rawData);
+
+  if (!parsedData.success) {
+    return context.json({ error: parsedData.error }, 401);
+  }
+
+  const { ip, port } = parsedData.data;
+
+  const result = await connectToAddress(ip, port)
+
+  return context.json({
+    isOpen: result.isOpen
+  })
+});

src/utils/connect-to-address.ts

@@ -0,0 +1,43 @@
+export interface ConnectionResult {
+  isOpen: boolean
+}
+
+const TIMEOUT = 5
+
+export default function connectToAddress(address: string, port: number): Promise<ConnectionResult> {
+  return new Promise<ConnectionResult>(async (resolve) => {
+    const socket = await Bun.connect({
+      hostname: address,
+      port: port,
+
+      socket: {
+        open(socket) {
+          socket.end()
+          resolve({
+            isOpen: true
+          })
+        },
+        data() {
+        },
+        connectError() {
+          resolve({
+            isOpen: false
+          })
+        },
+        error(socket) {
+          socket.end()
+          resolve({
+            isOpen: false
+          })
+        },
+        timeout() {
+          resolve({
+            isOpen: false
+          })
+        },
+      }
+    })
+
+    socket.timeout(TIMEOUT)
+  })
+}