limit connections (#18355)

limit background connections

app/scripts/background.js

@@ -32,6 +32,7 @@ import {
 import { checkForLastErrorAndLog } from '../../shared/modules/browser-runtime.utils';
 import { isManifestV3 } from '../../shared/modules/mv3.utils';
 import { maskObject } from '../../shared/modules/object.utils';
+import { getEnvironmentType, deferredPromise, getPlatform } from './lib/util';
 import migrations from './migrations';
 import Migrator from './lib/migrator';
 import ExtensionPlatform from './platforms/extension';
@@ -50,7 +51,6 @@ import rawFirstTimeState from './first-time-state';
 import getFirstPreferredLangCode from './lib/get-first-preferred-lang-code';
 import getObjStructure from './lib/getObjStructure';
 import setupEnsIpfsResolver from './lib/ens-ipfs/setup';
-import { deferredPromise, getPlatform } from './lib/util';
 
 /* eslint-enable import/first */
 
@@ -84,6 +84,7 @@ let popupIsOpen = false;
 let notificationIsOpen = false;
 let uiIsTriggering = false;
 const openMetamaskTabsIDs = {};
+const openMetamaskConnections = new Map();
 const requestAccountTabIds = {};
 let controller;
 
@@ -184,10 +185,28 @@ let connectExternal;
 browser.runtime.onConnect.addListener(async (...args) => {
   // Queue up connection attempts here, waiting until after initialization
   await isInitialized;
+  const remotePort = args[0];
+  const { sender } = remotePort;
 
-  // This is set in `setupController`, which is called as part of initialization
-  connectRemote(...args);
+  const url = sender?.url;
+  const detectedProcessName = url ? getEnvironmentType(url) : '';
+
+  const connectionId = generateConnectionId(remotePort, detectedProcessName);
+  const openConnections = openMetamaskConnections.get(connectionId) || 0;
+
+  if (
+    openConnections === 0 ||
+    (detectedProcessName === 'background' && openConnections < 2)
+    // 2 background connections are allowed, one for phishing warning page and one for the ledger bridge keyring
+  ) {
+    // This is set in `setupController`, which is called as part of initialization
+    connectRemote(...args);
+    openMetamaskConnections.set(connectionId, openConnections + 1);
+  } else {
+    throw new Error('CONNECTION_ALREADY_EXISTS');
+  }
 });
+
 browser.runtime.onConnectExternal.addListener(async (...args) => {
   // Queue up connection attempts here, waiting until after initialization
   await isInitialized;
@@ -416,6 +435,21 @@ export async function loadStateFromPersistence() {
   return versionedData.data;
 }
 
+function generateConnectionId(remotePort, detectedProcessName) {
+  const { sender } = remotePort;
+  const id = sender?.tab ? sender.tab.id : sender?.id;
+  if (!id || !detectedProcessName) {
+    console.error(
+      'Must provide id and detectedProcessName to generate connection id.',
+      id,
+      detectedProcessName,
+    ); // eslint-disable-line no-console
+    throw new Error(
+      'Must provide id and detectedProcessName to generate connection id.',
+    );
+  }
+  return `${id}-${detectedProcessName}`;
+}
 /**
  * Initializes the MetaMask Controller with any initial state and default language.
  * Configures platform-specific error reporting strategy.
@@ -570,7 +604,6 @@ export function setupController(
       // communication with popup
       controller.isClientOpen = true;
       controller.setupTrustedCommunication(portStream, remotePort.sender);
-
       if (isManifestV3) {
         // If we get a WORKER_KEEP_ALIVE message, we respond with an ACK
         remotePort.onMessage.addListener((message) => {
@@ -585,9 +618,11 @@ export function setupController(
         });
       }
 
+      const connectionId = generateConnectionId(remotePort, processName);
       if (processName === ENVIRONMENT_TYPE_POPUP) {
         popupIsOpen = true;
         endOfStream(portStream, () => {
+          openMetamaskConnections.set(connectionId, 0);
           popupIsOpen = false;
           const isClientOpen = isClientOpenStatus();
           controller.isClientOpen = isClientOpen;
@@ -597,8 +632,8 @@ export function setupController(
 
       if (processName === ENVIRONMENT_TYPE_NOTIFICATION) {
         notificationIsOpen = true;
-
         endOfStream(portStream, () => {
+          openMetamaskConnections.set(connectionId, 0);
           notificationIsOpen = false;
           const isClientOpen = isClientOpenStatus();
           controller.isClientOpen = isClientOpen;
@@ -614,6 +649,7 @@ export function setupController(
         openMetamaskTabsIDs[tabId] = true;
 
         endOfStream(portStream, () => {
+          openMetamaskConnections.set(connectionId, 0);
           delete openMetamaskTabsIDs[tabId];
           const isClientOpen = isClientOpenStatus();
           controller.isClientOpen = isClientOpen;