Security checks

src/extension.ts

@@ -1,6 +1,9 @@
 import * as vscode from "vscode";
 import { currentRun, startRun, stopRun } from "./run";
 import { startServer, stopServer } from "./server";
+import os from "os";
+import { exec } from "child_process";
+import net from "net";
 
 export function activate(context: vscode.ExtensionContext) {
   const config = vscode.workspace.getConfiguration("devrun");
@@ -50,14 +53,99 @@ export function activate(context: vscode.ExtensionContext) {
   );
   console.log("dev-run Activated");
 
+  // Security check - Make sure there aren't any malicious servers currently running
   const autoStart = config.get<boolean>("autoStartServer");
 
+  canConnect(63780)
+    .then((canConnect) => {
+      if (canConnect) {
+        console.error(
+          "Unable to start due to another process listening on port 63780",
+        );
+
+        console.error("Possible malicious dev-run instance running");
+
+        vscode.window
+          .showErrorMessage(
+            "Possible malicious dev-run instance running",
+            "Kill the process listening on port 63780",
+          )
+          .then(async (response) => {
+            if (!response) return;
+
+            if (response === "Kill the process listening on port 63780") {
+              await killProcessOnPort(63780);
+
               if (autoStart) {
                 startServer(statusBarItem);
                 console.log("dev-run server auto started!");
               }
+            }
+          });
+
+        return;
+      }
+
+      if (autoStart) {
+        startServer(statusBarItem);
+        console.log("dev-run server auto started!");
+      }
+    })
+    .catch(() => {});
 }
 
 export function deactivate() {
   stopRun();
 }
+
+export function canConnect(
+  port: number,
+  host = "127.0.0.1",
+  timeout = 1000,
+): Promise<boolean> {
+  return new Promise((resolve) => {
+    const socket = new net.Socket();
+
+    socket.setTimeout(timeout);
+
+    socket.once("connect", () => {
+      socket.destroy();
+      resolve(true);
+    });
+
+    socket.once("timeout", () => {
+      socket.destroy();
+      resolve(false);
+    });
+
+    socket.once("error", () => {
+      resolve(false);
+    });
+
+    socket.connect(port, host);
+  });
+}
+
+export function killProcessOnPort(port: number): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const platform = os.platform();
+
+    let cmd: string;
+
+    if (platform === "win32") {
+      // Windows
+      cmd = `for /f "tokens=5" %a in ('netstat -ano ^| findstr :${port}') do taskkill /PID %a /F`;
+    } else {
+      // macOS / Linux
+      cmd = `lsof -ti tcp:${port} | xargs kill -9`;
+    }
+
+    exec(cmd, (error) => {
+      if (error) {
+        resolve();
+      } else {
+        resolve();
+      }
+    });
+  });
+}