[NFCT.TETHER.14] Clear the BPF maps in BpfCoordinator ctor am: 499d3cac73 am: 129077bd58

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1623669

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I6d09c8f877c717670cf2e1462ec0146b1a0106dd

Tethering/apishim/31/com/android/networkstack/tethering/apishim/api31/BpfCoordinatorShimImpl.java

@@ -84,12 +84,46 @@ public class BpfCoordinatorShimImpl
 
     public BpfCoordinatorShimImpl(@NonNull final Dependencies deps) {
         mLog = deps.getSharedLog().forSubComponent(TAG);
+
         mBpfDownstream4Map = deps.getBpfDownstream4Map();
         mBpfUpstream4Map = deps.getBpfUpstream4Map();
         mBpfDownstream6Map = deps.getBpfDownstream6Map();
         mBpfUpstream6Map = deps.getBpfUpstream6Map();
         mBpfStatsMap = deps.getBpfStatsMap();
         mBpfLimitMap = deps.getBpfLimitMap();
+
+        // Clear the stubs of the maps for handling the system service crash if any.
+        // Doesn't throw the exception and clear the stubs as many as possible.
+        try {
+            if (mBpfDownstream4Map != null) mBpfDownstream4Map.clear();
+        } catch (ErrnoException e) {
+            mLog.e("Could not clear mBpfDownstream4Map: " + e);
+        }
+        try {
+            if (mBpfUpstream4Map != null) mBpfUpstream4Map.clear();
+        } catch (ErrnoException e) {
+            mLog.e("Could not clear mBpfUpstream4Map: " + e);
+        }
+        try {
+            if (mBpfDownstream6Map != null) mBpfDownstream6Map.clear();
+        } catch (ErrnoException e) {
+            mLog.e("Could not clear mBpfDownstream6Map: " + e);
+        }
+        try {
+            if (mBpfUpstream6Map != null) mBpfUpstream6Map.clear();
+        } catch (ErrnoException e) {
+            mLog.e("Could not clear mBpfUpstream6Map: " + e);
+        }
+        try {
+            if (mBpfStatsMap != null) mBpfStatsMap.clear();
+        } catch (ErrnoException e) {
+            mLog.e("Could not clear mBpfStatsMap: " + e);
+        }
+        try {
+            if (mBpfLimitMap != null) mBpfLimitMap.clear();
+        } catch (ErrnoException e) {
+            mLog.e("Could not clear mBpfLimitMap: " + e);
+        }
     }
 
     @Override

Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java

@@ -224,6 +224,7 @@ public class BpfCoordinator {
         maybeSchedulePollingStats();
     };
 
+    // TODO: add BpfMap<TetherDownstream64Key, TetherDownstream64Value> retrieving function.
     @VisibleForTesting
     public abstract static class Dependencies {
         /** Get handler. */

Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java

@@ -150,6 +150,12 @@ public class BpfCoordinatorTest {
             // BpfMap#getValue treats that the entry is not found as no error.
             return mMap.get(key);
         }
+
+        @Override
+        public void clear() throws ErrnoException {
+            // TODO: consider using mocked #getFirstKey and #deleteEntry to implement.
+            mMap.clear();
+        }
     };
 
     @Mock private NetworkStatsManager mStatsManager;
@@ -986,6 +992,24 @@ public class BpfCoordinatorTest {
         checkBpfDisabled();
     }
 
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.R)
+    public void testBpfDisabledbyNoBpfDownstream4Map() throws Exception {
+        setupFunctioningNetdInterface();
+        doReturn(null).when(mDeps).getBpfDownstream4Map();
+
+        checkBpfDisabled();
+    }
+
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.R)
+    public void testBpfDisabledbyNoBpfUpstream4Map() throws Exception {
+        setupFunctioningNetdInterface();
+        doReturn(null).when(mDeps).getBpfUpstream4Map();
+
+        checkBpfDisabled();
+    }
+
     @Test
     @IgnoreUpTo(Build.VERSION_CODES.R)
     public void testBpfDisabledbyNoBpfStatsMap() throws Exception {
@@ -1004,6 +1028,20 @@ public class BpfCoordinatorTest {
         checkBpfDisabled();
     }
 
+    @Test
+    @IgnoreUpTo(Build.VERSION_CODES.R)
+    public void testBpfMapClear() throws Exception {
+        setupFunctioningNetdInterface();
+
+        final BpfCoordinator coordinator = makeBpfCoordinator();
+        verify(mBpfDownstream4Map).clear();
+        verify(mBpfUpstream4Map).clear();
+        verify(mBpfDownstream6Map).clear();
+        verify(mBpfUpstream6Map).clear();
+        verify(mBpfStatsMap).clear();
+        verify(mBpfLimitMap).clear();
+    }
+
     @Test
     public void testTetheringConfigSetPollingInterval() throws Exception {
         setupFunctioningNetdInterface();