From b59c829ff1da4594d42873d6b351e0f25e2fd5e1 Mon Sep 17 00:00:00 2001
From: Handa Wang <handaw@google.com>
Date: Mon, 28 Apr 2025 01:59:39 -0700
Subject: [PATCH] Ensure Thread network is never mDNS capable

Thread doesn't use mDNS and we should prevent NsdService from sending any mDNS traffic to Thread.

Bug: 414258735
Test: CI
Flag: EXEMPT bugfix
Change-Id: I62299769cd44d2984b81b273adea7ce459d3d773
---
 .../server/connectivity/mdns/MdnsSocketProvider.java |  4 +++-
 .../connectivity/mdns/MdnsSocketProviderTest.java    | 12 ++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java b/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
index d91bd112b3..49e4e28d32 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsSocketProvider.java
@@ -17,6 +17,7 @@
 package com.android.server.connectivity.mdns;
 
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
+import static android.net.NetworkCapabilities.TRANSPORT_THREAD;
 import static android.net.NetworkCapabilities.TRANSPORT_VPN;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
 
@@ -561,8 +562,9 @@ public class MdnsSocketProvider {
     private boolean isMdnsCapableInterface(
             @NonNull NetworkInterfaceWrapper iface, @NonNull int[] transports) {
         try {
-            // Never try mDNS on cellular, or on interfaces with incompatible flags
+            // Never try mDNS on cellular, on Thread, or on interfaces with incompatible flags
             if (CollectionUtils.contains(transports, TRANSPORT_CELLULAR)
+                    || CollectionUtils.contains(transports, TRANSPORT_THREAD)
                     || iface.isLoopback()
                     || iface.isVirtual()
                     || !iface.isUp()) {
diff --git a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
index f763bae09a..6bcc4ed442 100644
--- a/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
+++ b/tests/unit/java/com/android/server/connectivity/mdns/MdnsSocketProviderTest.java
@@ -18,6 +18,7 @@ package com.android.server.connectivity.mdns;
 
 import static android.net.NetworkCapabilities.TRANSPORT_BLUETOOTH;
 import static android.net.NetworkCapabilities.TRANSPORT_CELLULAR;
+import static android.net.NetworkCapabilities.TRANSPORT_THREAD;
 import static android.net.NetworkCapabilities.TRANSPORT_VPN;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
 
@@ -596,6 +597,17 @@ public class MdnsSocketProviderTest {
         testCallback.expectedNoCallback();
     }
 
+    @Test
+    public void testNoSocketCreatedForThread() {
+        startMonitoringSockets();
+
+        final TestSocketCallback testCallback = new TestSocketCallback();
+        runOnHandler(() -> mSocketProvider.requestSocket(TEST_NETWORK, testCallback));
+
+        postNetworkAvailable(TRANSPORT_THREAD);
+        testCallback.expectedNoCallback();
+    }
+
     @Test
     public void testNoSocketCreatedForNonMulticastInterface() throws Exception {
         doReturn(false).when(mTestNetworkIfaceWrapper).supportsMulticast();