commit 80c9f6f35f26db3caed5ba224d2ec3935c8ce0eb
author Ken Chen <cken@google.com> Wed Nov 15 18:24:54 2023 +0800
committer Ken Chen <cken@google.com> Wed Dec 27 13:54:50 2023 +0000
tree de2ac88fa293f837cf8ce858f0a893a363b1425b
parent 81e643929852ff3d60a4d0cd306ed3bfb47a4e97

Stop registering native mdns service

NsdService switched from Netd native solution to Java solution on
Android U. MDNS service provided by Netd will be removed from Android V.

1. Stop registering native mdns service from V.
2. Stop startDaemon() in NsdManager from V.
3. As a double safety, return early in NsdService methods that call the
   native mdns service when platform version is V+.
4. Modify NsdManagerTest to cover V+ behavior.

Bug: 298594687
Test: Build. Presubmit.
Change-Id: Ifdac8f7a44aa57d93d453ba482ec473a2b531452

service-t/src/com/android/server/NsdService.java

diff --git a/service-t/src/com/android/server/NsdService.java b/service-t/src/com/android/server/NsdService.java
index cc9d53d..76481c8 100644
--- a/service-t/src/com/android/server/NsdService.java
+++ b/service-t/src/com/android/server/NsdService.java
@@ -199,7 +199,8 @@
 
     private final Context mContext;
     private final NsdStateMachine mNsdStateMachine;
-    private final MDnsManager mMDnsManager;
+    // It can be null on V+ device since mdns native service provided by netd is removed.
+    private final @Nullable MDnsManager mMDnsManager;
     private final MDnsEventCallback mMDnsEventCallback;
     @NonNull
     private final Dependencies mDeps;
@@ -541,6 +542,11 @@
         }
 
         private void maybeStartDaemon() {
+            if (mMDnsManager == null) {
+                Log.wtf(TAG, "maybeStartDaemon: mMDnsManager is null");
+                return;
+            }
+
             if (mIsDaemonStarted) {
                 if (DBG) Log.d(TAG, "Daemon is already started.");
                 return;
@@ -553,6 +559,11 @@
         }
 
         private void maybeStopDaemon() {
+            if (mMDnsManager == null) {
+                Log.wtf(TAG, "maybeStopDaemon: mMDnsManager is null");
+                return;
+            }
+
             if (!mIsDaemonStarted) {
                 if (DBG) Log.d(TAG, "Daemon has not been started.");
                 return;
@@ -1698,7 +1709,8 @@
         mContext = ctx;
         mNsdStateMachine = new NsdStateMachine(TAG, handler);
         mNsdStateMachine.start();
-        mMDnsManager = ctx.getSystemService(MDnsManager.class);
+        // It can fail on V+ device since mdns native service provided by netd is removed.
+        mMDnsManager = SdkLevel.isAtLeastV() ? null : ctx.getSystemService(MDnsManager.class);
         mMDnsEventCallback = new MDnsEventCallback(mNsdStateMachine);
         mDeps = deps;
 
@@ -2235,6 +2247,11 @@
     }
 
     private boolean registerService(int transactionId, NsdServiceInfo service) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "registerService: mMDnsManager is null");
+            return false;
+        }
+
         if (DBG) {
             Log.d(TAG, "registerService: " + transactionId + " " + service);
         }
@@ -2252,10 +2269,19 @@
     }
 
     private boolean unregisterService(int transactionId) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "unregisterService: mMDnsManager is null");
+            return false;
+        }
         return mMDnsManager.stopOperation(transactionId);
     }
 
     private boolean discoverServices(int transactionId, NsdServiceInfo serviceInfo) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "discoverServices: mMDnsManager is null");
+            return false;
+        }
+
         final String type = serviceInfo.getServiceType();
         final int discoverInterface = getNetworkInterfaceIndex(serviceInfo);
         if (serviceInfo.getNetwork() != null && discoverInterface == IFACE_IDX_ANY) {
@@ -2266,10 +2292,18 @@
     }
 
     private boolean stopServiceDiscovery(int transactionId) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "stopServiceDiscovery: mMDnsManager is null");
+            return false;
+        }
         return mMDnsManager.stopOperation(transactionId);
     }
 
     private boolean resolveService(int transactionId, NsdServiceInfo service) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "resolveService: mMDnsManager is null");
+            return false;
+        }
         final String name = service.getServiceName();
         final String type = service.getServiceType();
         final int resolveInterface = getNetworkInterfaceIndex(service);
@@ -2343,14 +2377,26 @@
     }
 
     private boolean stopResolveService(int transactionId) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "stopResolveService: mMDnsManager is null");
+            return false;
+        }
         return mMDnsManager.stopOperation(transactionId);
     }
 
     private boolean getAddrInfo(int transactionId, String hostname, int interfaceIdx) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "getAddrInfo: mMDnsManager is null");
+            return false;
+        }
         return mMDnsManager.getServiceAddress(transactionId, hostname, interfaceIdx);
     }
 
     private boolean stopGetAddrInfo(int transactionId) {
+        if (mMDnsManager == null) {
+            Log.wtf(TAG, "stopGetAddrInfo: mMDnsManager is null");
+            return false;
+        }
         return mMDnsManager.stopOperation(transactionId);
     }