Add flag to test BpfNetMaps refactoring

Following CLs will switch previous codepath (JNI) and new codepath
(Java) for bpf map operations based on this flag.

Bug: 217624062
Test: atest BpfNetMapsTest
Change-Id: I74f10d5c97390993acea110f6528ef8980bb2aa4

service-t/src/com/android/server/net/NetworkStatsFactory.java

@@ -164,7 +164,7 @@ public class NetworkStatsFactory {
     }
 
     public NetworkStatsFactory(@NonNull Context ctx) {
-        this(ctx, new File("/proc/"), true, new BpfNetMaps());
+        this(ctx, new File("/proc/"), true, new BpfNetMaps(ctx));
     }
 
     @VisibleForTesting

service/src/com/android/server/BpfNetMaps.java

@@ -31,9 +31,11 @@ import static android.system.OsConstants.ENODEV;
 import static android.system.OsConstants.ENOENT;
 import static android.system.OsConstants.EOPNOTSUPP;
 
+import android.content.Context;
 import android.net.INetd;
 import android.os.RemoteException;
 import android.os.ServiceSpecificException;
+import android.provider.DeviceConfig;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.util.Log;
@@ -42,6 +44,7 @@ import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.BpfMap;
+import com.android.net.module.util.DeviceConfigUtils;
 import com.android.net.module.util.Struct.U32;
 
 import java.io.FileDescriptor;
@@ -70,6 +73,10 @@ public class BpfNetMaps {
     // Use legacy netd for releases before T.
     private static boolean sInitialized = false;
 
+    private static Boolean sEnableJavaBpfMap = null;
+    private static final String BPF_NET_MAPS_ENABLE_JAVA_BPF_MAP =
+            "bpf_net_maps_enable_java_bpf_map";
+
     // Lock for sConfigurationMap entry for UID_RULES_CONFIGURATION_KEY.
     // This entry is not accessed by others.
     // BpfNetMaps acquires this lock while sequence of read, modify, and write.
@@ -100,6 +107,14 @@ public class BpfNetMaps {
     @VisibleForTesting public static final long OEM_DENY_3_MATCH = (1 << 11);
     // LINT.ThenChange(packages/modules/Connectivity/bpf_progs/bpf_shared.h)
 
+    /**
+     * Set sEnableJavaBpfMap for test.
+     */
+    @VisibleForTesting
+    public static void setEnableJavaBpfMapForTest(boolean enable) {
+        sEnableJavaBpfMap = enable;
+    }
+
     /**
      * Set configurationMap for test.
      */
@@ -147,8 +162,15 @@ public class BpfNetMaps {
      * Initializes the class if it is not already initialized. This method will open maps but not
      * cause any other effects. This method may be called multiple times on any thread.
      */
-    private static synchronized void ensureInitialized() {
+    private static synchronized void ensureInitialized(final Context context) {
         if (sInitialized) return;
+        if (sEnableJavaBpfMap == null) {
+            sEnableJavaBpfMap = DeviceConfigUtils.isFeatureEnabled(context,
+                    DeviceConfig.NAMESPACE_TETHERING, BPF_NET_MAPS_ENABLE_JAVA_BPF_MAP,
+                    SdkLevel.isAtLeastU() /* defaultValue */);
+        }
+        Log.d(TAG, "BpfNetMaps is initialized with sEnableJavaBpfMap=" + sEnableJavaBpfMap);
+
         setBpfMaps();
         native_init();
         sInitialized = true;
@@ -168,20 +190,20 @@ public class BpfNetMaps {
     }
 
     /** Constructor used after T that doesn't need to use netd anymore. */
-    public BpfNetMaps() {
+    public BpfNetMaps(final Context context) {
-        this(null);
+        this(context, null);
 
         if (PRE_T) throw new IllegalArgumentException("BpfNetMaps need to use netd before T");
     }
 
-    public BpfNetMaps(final INetd netd) {
+    public BpfNetMaps(final Context context, final INetd netd) {
-        this(netd, new Dependencies());
+        this(context, netd, new Dependencies());
     }
 
     @VisibleForTesting
-    public BpfNetMaps(final INetd netd, final Dependencies deps) {
+    public BpfNetMaps(final Context context, final INetd netd, final Dependencies deps) {
         if (!PRE_T) {
-            ensureInitialized();
+            ensureInitialized(context);
         }
         mNetd = netd;
         mDeps = deps;

service/src/com/android/server/ConnectivityService.java

@@ -1399,8 +1399,8 @@ public class ConnectivityService extends IConnectivityManager.Stub
          * @param netd
          * @return BpfNetMaps implementation.
          */
-        public BpfNetMaps getBpfNetMaps(INetd netd) {
+        public BpfNetMaps getBpfNetMaps(Context context, INetd netd) {
-            return new BpfNetMaps(netd);
+            return new BpfNetMaps(context, netd);
         }
 
         /**
@@ -1529,7 +1529,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
         mProxyTracker = mDeps.makeProxyTracker(mContext, mHandler);
 
         mNetd = netd;
-        mBpfNetMaps = mDeps.getBpfNetMaps(netd);
+        mBpfNetMaps = mDeps.getBpfNetMaps(mContext, netd);
         mTelephonyManager = (TelephonyManager) mContext.getSystemService(Context.TELEPHONY_SERVICE);
         mAppOpsManager = (AppOpsManager) mContext.getSystemService(Context.APP_OPS_SERVICE);
         mLocationPermissionChecker = mDeps.makeLocationPermissionChecker(mContext);

tests/integration/src/com/android/server/net/integrationtests/ConnectivityServiceIntegrationTest.kt

@@ -209,7 +209,7 @@ class ConnectivityServiceIntegrationTest {
         doReturn(mock(ProxyTracker::class.java)).`when`(deps).makeProxyTracker(any(), any())
         doReturn(mock(MockableSystemProperties::class.java)).`when`(deps).systemProperties
         doReturn(TestNetIdManager()).`when`(deps).makeNetIdManager()
-        doReturn(mock(BpfNetMaps::class.java)).`when`(deps).getBpfNetMaps(any())
+        doReturn(mock(BpfNetMaps::class.java)).`when`(deps).getBpfNetMaps(any(), any())
         doAnswer { inv ->
             object : MultinetworkPolicyTracker(inv.getArgument(0), inv.getArgument(1),
                     inv.getArgument(2)) {

tests/unit/java/com/android/server/BpfNetMapsTest.java

@@ -46,6 +46,7 @@ import static org.junit.Assume.assumeFalse;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.verify;
 
+import android.content.Context;
 import android.net.INetd;
 import android.os.Build;
 import android.os.ServiceSpecificException;
@@ -102,6 +103,7 @@ public final class BpfNetMapsTest {
 
     @Mock INetd mNetd;
     @Mock BpfNetMaps.Dependencies mDeps;
+    @Mock Context mContext;
     private final BpfMap<U32, U32> mConfigurationMap = new TestBpfMap<>(U32.class, U32.class);
     private final BpfMap<U32, UidOwnerValue> mUidOwnerMap =
             new TestBpfMap<>(U32.class, UidOwnerValue.class);
@@ -110,9 +112,10 @@ public final class BpfNetMapsTest {
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
         doReturn(TEST_IF_INDEX).when(mDeps).getIfIndex(TEST_IF_NAME);
+        BpfNetMaps.setEnableJavaBpfMapForTest(true /* enable */);
         BpfNetMaps.setConfigurationMapForTest(mConfigurationMap);
         BpfNetMaps.setUidOwnerMapForTest(mUidOwnerMap);
-        mBpfNetMaps = new BpfNetMaps(mNetd, mDeps);
+        mBpfNetMaps = new BpfNetMaps(mContext, mNetd, mDeps);
     }
 
     @Test

tests/unit/java/com/android/server/ConnectivityServiceTest.java

@@ -2061,7 +2061,7 @@ public class ConnectivityServiceTest {
         }
 
         @Override
-        public BpfNetMaps getBpfNetMaps(INetd netd) {
+        public BpfNetMaps getBpfNetMaps(Context context, INetd netd) {
             return mBpfNetMaps;
         }