diff --git a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
index d5d71bc..f8aa69f 100644
--- a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
+++ b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
@@ -22,19 +22,24 @@
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.junit.Assume.assumeTrue;
 
 import android.net.MacAddress;
 import android.os.Build;
+import android.os.SystemClock;
 import android.system.ErrnoException;
 import android.system.Os;
 import android.system.OsConstants;
 import android.util.ArrayMap;
 
 import com.android.net.module.util.BpfMap;
+import com.android.net.module.util.SingleWriterBpfMap;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.DevSdkIgnoreRunner;
 
@@ -42,10 +47,18 @@
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
 
 import java.io.File;
 import java.net.InetAddress;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.NoSuchElementException;
+import java.util.Random;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 
@@ -61,6 +74,17 @@
 
     private BpfMap<TetherDownstream6Key, Tether6Value> mTestMap;
 
+    private final boolean mShouldTestSingleWriterMap;
+
+    @Parameterized.Parameters
+    public static Collection<Boolean> shouldTestSingleWriterMap() {
+        return Arrays.asList(true, false);
+    }
+
+    public BpfMapTest(boolean shouldTestSingleWriterMap) {
+        mShouldTestSingleWriterMap = shouldTestSingleWriterMap;
+    }
+
     @BeforeClass
     public static void setupOnce() {
         System.loadLibrary(getTetheringJniLibraryName());
@@ -82,11 +106,16 @@
         initTestMap();
     }
 
-    private void initTestMap() throws Exception {
-        mTestMap = new BpfMap<>(
-                TETHER_DOWNSTREAM6_FS_PATH,
-                TetherDownstream6Key.class, Tether6Value.class);
+    private BpfMap<TetherDownstream6Key, Tether6Value> openTestMap() throws Exception {
+        return mShouldTestSingleWriterMap
+                ? new SingleWriterBpfMap<>(TETHER_DOWNSTREAM6_FS_PATH, TetherDownstream6Key.class,
+                Tether6Value.class)
+                : new BpfMap<>(TETHER_DOWNSTREAM6_FS_PATH, TetherDownstream6Key.class,
+                        Tether6Value.class);
+    }
 
+    private void initTestMap() throws Exception {
+        mTestMap = openTestMap();
         mTestMap.forEach((key, value) -> {
             try {
                 assertTrue(mTestMap.deleteEntry(key));
@@ -357,6 +386,25 @@
     }
 
     @Test
+    public void testMapContentsCorrectOnOpen() throws Exception {
+        final BpfMap<TetherDownstream6Key, Tether6Value> map1, map2;
+
+        map1 = openTestMap();
+        map1.clear();
+        for (int i = 0; i < mTestData.size(); i++) {
+            map1.insertEntry(mTestData.keyAt(i), mTestData.valueAt(i));
+        }
+
+        // We can't close and reopen map1, because close does nothing. Open another map instead.
+        map2 = openTestMap();
+        for (int i = 0; i < mTestData.size(); i++) {
+            assertEquals(mTestData.valueAt(i), map2.getValue(mTestData.keyAt(i)));
+        }
+
+        map1.clear();
+    }
+
+    @Test
     public void testInsertOverflow() throws Exception {
         final ArrayMap<TetherDownstream6Key, Tether6Value> testData =
                 new ArrayMap<>();
@@ -396,8 +444,18 @@
         }
     }
 
-    private static int getNumOpenFds() {
-        return new File("/proc/" + Os.getpid() + "/fd").listFiles().length;
+    private static int getNumOpenBpfMapFds() throws Exception {
+        int numFds = 0;
+        File[] openFiles = new File("/proc/self/fd").listFiles();
+        for (int i = 0; i < openFiles.length; i++) {
+            final Path path = openFiles[i].toPath();
+            if (!Files.isSymbolicLink(path)) continue;
+            if ("anon_inode:bpf-map".equals(Files.readSymbolicLink(path).toString())) {
+                numFds++;
+            }
+        }
+        assertNotEquals("Couldn't find any BPF map fds opened by this process", 0, numFds);
+        return numFds;
     }
 
     @Test
@@ -406,7 +464,7 @@
         // cache, expect that the fd amount is not increased in the iterations.
         // See the comment of BpfMap#close.
         final int iterations = 1000;
-        final int before = getNumOpenFds();
+        final int before = getNumOpenBpfMapFds();
         for (int i = 0; i < iterations; i++) {
             try (BpfMap<TetherDownstream6Key, Tether6Value> map = new BpfMap<>(
                     TETHER_DOWNSTREAM6_FS_PATH,
@@ -414,15 +472,74 @@
                 // do nothing
             }
         }
-        final int after = getNumOpenFds();
+        final int after = getNumOpenBpfMapFds();
 
         // Check that the number of open fds is the same as before.
-        // If this exact match becomes flaky, we probably need to distinguish that fd is belong
-        // to "bpf-map".
-        // ex:
-        // $ adb shell ls -all /proc/16196/fd
-        // [..] network_stack 64 2022-07-26 22:01:02.300002956 +0800 749 -> anon_inode:bpf-map
-        // [..] network_stack 64 2022-07-26 22:01:02.188002956 +0800 75 -> anon_inode:[eventfd]
         assertEquals("Fd leak after " + iterations + " iterations: ", before, after);
     }
+
+    @Test
+    public void testNullKey() {
+        assertThrows(NullPointerException.class, () ->
+                mTestMap.insertOrReplaceEntry(null, mTestData.valueAt(0)));
+    }
+
+    private void runBenchmarkThread(BpfMap<TetherDownstream6Key, Tether6Value> map,
+            CompletableFuture<Integer> future, int runtimeMs) {
+        int numReads = 0;
+        final Random r = new Random();
+        final long start = SystemClock.elapsedRealtime();
+        final long stop = start + runtimeMs;
+        while (SystemClock.elapsedRealtime() < stop) {
+            try {
+                final Tether6Value v = map.getValue(mTestData.keyAt(r.nextInt(mTestData.size())));
+                assertNotNull(v);
+                numReads++;
+            } catch (Exception e) {
+                future.completeExceptionally(e);
+                return;
+            }
+        }
+        future.complete(numReads);
+    }
+
+    @Test
+    public void testSingleWriterCacheEffectiveness() throws Exception {
+        assumeTrue(mShouldTestSingleWriterMap);
+
+        // Ensure the map is not empty.
+        for (int i = 0; i < mTestData.size(); i++) {
+            mTestMap.insertEntry(mTestData.keyAt(i), mTestData.valueAt(i));
+        }
+
+        // Benchmark parameters.
+        final int timeoutMs = 5_000;  // Only hit if threads don't complete.
+        final int benchmarkTimeMs = 2_000;
+        final int minReads = 50;
+        // Local testing on cuttlefish suggests that caching is ~10x faster.
+        // Only require 3x to reduce test flakiness.
+        final int expectedSpeedup = 3;
+
+        final BpfMap cachedMap = new SingleWriterBpfMap(TETHER_DOWNSTREAM6_FS_PATH,
+                TetherDownstream6Key.class, Tether6Value.class);
+        final BpfMap uncachedMap = new BpfMap(TETHER_DOWNSTREAM6_FS_PATH,
+                TetherDownstream6Key.class, Tether6Value.class);
+
+        final CompletableFuture<Integer> cachedResult = new CompletableFuture<>();
+        final CompletableFuture<Integer> uncachedResult = new CompletableFuture<>();
+
+        new Thread(() -> runBenchmarkThread(uncachedMap, uncachedResult, benchmarkTimeMs)).start();
+        new Thread(() -> runBenchmarkThread(cachedMap, cachedResult, benchmarkTimeMs)).start();
+
+        final int cached = cachedResult.get(timeoutMs, TimeUnit.MILLISECONDS);
+        final int uncached = uncachedResult.get(timeoutMs, TimeUnit.MILLISECONDS);
+
+        // Uncomment to see benchmark results.
+        // fail("Cached " + cached + ", uncached " + uncached + ": " + cached / uncached  +"x");
+
+        assertTrue("Less than " + minReads + "cached reads observed", cached > minReads);
+        assertTrue("Less than " + minReads + "uncached reads observed", uncached > minReads);
+        assertTrue("Cached map not at least " + expectedSpeedup + "x faster",
+                cached > expectedSpeedup * uncached);
+    }
 }
diff --git a/framework/src/android/net/ConnectivityManager.java b/framework/src/android/net/ConnectivityManager.java
index 0b37fa5..4eaf973 100644
--- a/framework/src/android/net/ConnectivityManager.java
+++ b/framework/src/android/net/ConnectivityManager.java
@@ -28,6 +28,7 @@
 import android.annotation.CallbackExecutor;
 import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
+import android.annotation.LongDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.RequiresApi;
@@ -1207,6 +1208,16 @@
     })
     public @interface FirewallRule {}
 
+    /** @hide */
+    public static final long FEATURE_USE_DECLARED_METHODS_FOR_CALLBACKS = 1L;
+
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @LongDef(flag = true, prefix = "FEATURE_", value = {
+            FEATURE_USE_DECLARED_METHODS_FOR_CALLBACKS
+    })
+    public @interface ConnectivityManagerFeature {}
+
     /**
      * A kludge to facilitate static access where a Context pointer isn't available, like in the
      * case of the static set/getProcessDefaultNetwork methods and from the Network class.
@@ -1220,6 +1231,14 @@
     @GuardedBy("mTetheringEventCallbacks")
     private TetheringManager mTetheringManager;
 
+    private final Object mEnabledConnectivityManagerFeaturesLock = new Object();
+    // mEnabledConnectivityManagerFeatures is lazy-loaded in this ConnectivityManager instance, but
+    // fetched from ConnectivityService, where it is loaded in ConnectivityService startup, so it
+    // should have consistent values.
+    @GuardedBy("sEnabledConnectivityManagerFeaturesLock")
+    @ConnectivityManagerFeature
+    private Long mEnabledConnectivityManagerFeatures = null;
+
     private TetheringManager getTetheringManager() {
         synchronized (mTetheringEventCallbacks) {
             if (mTetheringManager == null) {
@@ -4529,6 +4548,20 @@
         return request;
     }
 
+    private boolean isFeatureEnabled(@ConnectivityManagerFeature long connectivityManagerFeature) {
+        synchronized (mEnabledConnectivityManagerFeaturesLock) {
+            if (mEnabledConnectivityManagerFeatures == null) {
+                try {
+                    mEnabledConnectivityManagerFeatures =
+                            mService.getEnabledConnectivityManagerFeatures();
+                } catch (RemoteException e) {
+                    e.rethrowFromSystemServer();
+                }
+            }
+            return (mEnabledConnectivityManagerFeatures & connectivityManagerFeature) != 0;
+        }
+    }
+
     private NetworkRequest sendRequestForNetwork(NetworkCapabilities need, NetworkCallback callback,
             int timeoutMs, NetworkRequest.Type reqType, int legacyType, CallbackHandler handler) {
         return sendRequestForNetwork(Process.INVALID_UID, need, callback, timeoutMs, reqType,
diff --git a/framework/src/android/net/IConnectivityManager.aidl b/framework/src/android/net/IConnectivityManager.aidl
index 55c7085..f9de8ed 100644
--- a/framework/src/android/net/IConnectivityManager.aidl
+++ b/framework/src/android/net/IConnectivityManager.aidl
@@ -259,4 +259,6 @@
     void setTestLowTcpPollingTimerForKeepalive(long timeMs);
 
     IBinder getRoutingCoordinatorService();
+
+    long getEnabledConnectivityManagerFeatures();
 }
diff --git a/framework/src/android/net/NetworkCapabilities.java b/framework/src/android/net/NetworkCapabilities.java
index 45efbfe..a5a6723 100644
--- a/framework/src/android/net/NetworkCapabilities.java
+++ b/framework/src/android/net/NetworkCapabilities.java
@@ -36,6 +36,7 @@
 import android.os.Process;
 import android.text.TextUtils;
 import android.util.ArraySet;
+import android.util.Log;
 import android.util.Range;
 
 import com.android.internal.annotations.VisibleForTesting;
@@ -843,7 +844,10 @@
         // If the given capability was previously added to the list of forbidden capabilities
         // then the capability will also be removed from the list of forbidden capabilities.
         // TODO: Add forbidden capabilities to the public API
-        checkValidCapability(capability);
+        if (!isValidCapability(capability)) {
+            Log.e(TAG, "addCapability is called with invalid capability: " + capability);
+            return this;
+        }
         mNetworkCapabilities |= 1L << capability;
         // remove from forbidden capability list
         mForbiddenNetworkCapabilities &= ~(1L << capability);
@@ -864,7 +868,10 @@
      * @hide
      */
     public void addForbiddenCapability(@NetCapability int capability) {
-        checkValidCapability(capability);
+        if (!isValidCapability(capability)) {
+            Log.e(TAG, "addForbiddenCapability is called with invalid capability: " + capability);
+            return;
+        }
         mForbiddenNetworkCapabilities |= 1L << capability;
         mNetworkCapabilities &= ~(1L << capability);  // remove from requested capabilities
     }
@@ -878,7 +885,10 @@
      * @hide
      */
     public @NonNull NetworkCapabilities removeCapability(@NetCapability int capability) {
-        checkValidCapability(capability);
+        if (!isValidCapability(capability)) {
+            Log.e(TAG, "removeCapability is called with invalid capability: " + capability);
+            return this;
+        }
         final long mask = ~(1L << capability);
         mNetworkCapabilities &= mask;
         return this;
@@ -893,7 +903,11 @@
      * @hide
      */
     public @NonNull NetworkCapabilities removeForbiddenCapability(@NetCapability int capability) {
-        checkValidCapability(capability);
+        if (!isValidCapability(capability)) {
+            Log.e(TAG,
+                    "removeForbiddenCapability is called with invalid capability: " + capability);
+            return this;
+        }
         mForbiddenNetworkCapabilities &= ~(1L << capability);
         return this;
     }
@@ -2632,12 +2646,6 @@
         return capability >= 0 && capability <= MAX_NET_CAPABILITY;
     }
 
-    private static void checkValidCapability(@NetworkCapabilities.NetCapability int capability) {
-        if (!isValidCapability(capability)) {
-            throw new IllegalArgumentException("NetworkCapability " + capability + " out of range");
-        }
-    }
-
     private static boolean isValidEnterpriseId(
             @NetworkCapabilities.EnterpriseId int enterpriseId) {
         return enterpriseId >= NET_ENTERPRISE_ID_1
diff --git a/service/ServiceConnectivityResources/res/values-ky/strings.xml b/service/ServiceConnectivityResources/res/values-ky/strings.xml
index 08ffd2a..398531a 100644
--- a/service/ServiceConnectivityResources/res/values-ky/strings.xml
+++ b/service/ServiceConnectivityResources/res/values-ky/strings.xml
@@ -26,7 +26,7 @@
     <string name="mobile_network_available_no_internet_detailed" msgid="5438738723127062816">"<xliff:g id="NETWORK_CARRIER">%1$s</xliff:g> трафиги түгөнгөн окшойт. Параметрлерди ачуу үчүн таптаңыз."</string>
     <string name="mobile_network_available_no_internet_detailed_unknown_carrier" msgid="5375681117265354337">"Трафик түгөнгөн окшойт. Параметрлерди ачуу үчүн таптаңыз."</string>
     <string name="wifi_no_internet" msgid="1326348603404555475">"<xliff:g id="NETWORK_SSID">%1$s</xliff:g> Интернетке туташуусу жок"</string>
-    <string name="wifi_no_internet_detailed" msgid="1746921096565304090">"Параметрлерди ачуу үчүн таптап коюңуз"</string>
+    <string name="wifi_no_internet_detailed" msgid="1746921096565304090">"Параметрлерди ачуу үчүн тийип коюңуз"</string>
     <string name="mobile_no_internet" msgid="4087718456753201450">"Мобилдик Интернет жок"</string>
     <string name="other_networks_no_internet" msgid="5693932964749676542">"Тармактын Интернет жок"</string>
     <string name="private_dns_broken_detailed" msgid="2677123850463207823">"Жеке DNS сервери жеткиликсиз"</string>
diff --git a/service/ServiceConnectivityResources/res/values-mn/strings.xml b/service/ServiceConnectivityResources/res/values-mn/strings.xml
index 2f13ef4..9af035b 100644
--- a/service/ServiceConnectivityResources/res/values-mn/strings.xml
+++ b/service/ServiceConnectivityResources/res/values-mn/strings.xml
@@ -27,7 +27,7 @@
     <string name="mobile_network_available_no_internet_detailed_unknown_carrier" msgid="5375681117265354337">"Таны дата дууссан байж магадгүй. Сонголтыг харахын тулд товшино уу."</string>
     <string name="wifi_no_internet" msgid="1326348603404555475">"<xliff:g id="NETWORK_SSID">%1$s</xliff:g>-д интернэтийн хандалт алга"</string>
     <string name="wifi_no_internet_detailed" msgid="1746921096565304090">"Сонголт хийхийн тулд товшино уу"</string>
-    <string name="mobile_no_internet" msgid="4087718456753201450">"Мобайл сүлжээнд интернэт хандалт байхгүй байна"</string>
+    <string name="mobile_no_internet" msgid="4087718456753201450">"Хөдөлгөөнт холбооны сүлжээнд интернэт хандалт байхгүй байна"</string>
     <string name="other_networks_no_internet" msgid="5693932964749676542">"Сүлжээнд интернэт хандалт байхгүй байна"</string>
     <string name="private_dns_broken_detailed" msgid="2677123850463207823">"Хувийн DNS серверт хандах боломжгүй байна"</string>
     <string name="network_partial_connectivity" msgid="5549503845834993258">"<xliff:g id="NETWORK_SSID">%1$s</xliff:g> зарим үйлчилгээнд хандах боломжгүй байна"</string>
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index 1047232..a30735a 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -72,6 +72,7 @@
 import com.android.net.module.util.BpfDump;
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.IBpfMap;
+import com.android.net.module.util.SingleWriterBpfMap;
 import com.android.net.module.util.Struct;
 import com.android.net.module.util.Struct.S32;
 import com.android.net.module.util.Struct.U32;
@@ -188,7 +189,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U32> getConfigurationMap() {
         try {
-            return new BpfMap<>(
+            return new SingleWriterBpfMap<>(
                     CONFIGURATION_MAP_PATH, S32.class, U32.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open netd configuration map", e);
@@ -198,7 +199,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, UidOwnerValue> getUidOwnerMap() {
         try {
-            return new BpfMap<>(
+            return new SingleWriterBpfMap<>(
                     UID_OWNER_MAP_PATH, S32.class, UidOwnerValue.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open uid owner map", e);
@@ -208,7 +209,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U8> getUidPermissionMap() {
         try {
-            return new BpfMap<>(
+            return new SingleWriterBpfMap<>(
                     UID_PERMISSION_MAP_PATH, S32.class, U8.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open uid permission map", e);
@@ -218,6 +219,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<CookieTagMapKey, CookieTagMapValue> getCookieTagMap() {
         try {
+            // Cannot use SingleWriterBpfMap because it's written by ClatCoordinator as well.
             return new BpfMap<>(COOKIE_TAG_MAP_PATH,
                     CookieTagMapKey.class, CookieTagMapValue.class);
         } catch (ErrnoException e) {
@@ -228,7 +230,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U8> getDataSaverEnabledMap() {
         try {
-            return new BpfMap<>(
+            return new SingleWriterBpfMap<>(
                     DATA_SAVER_ENABLED_MAP_PATH, S32.class, U8.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open data saver enabled map", e);
@@ -238,7 +240,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<IngressDiscardKey, IngressDiscardValue> getIngressDiscardMap() {
         try {
-            return new BpfMap<>(INGRESS_DISCARD_MAP_PATH,
+            return new SingleWriterBpfMap<>(INGRESS_DISCARD_MAP_PATH,
                     IngressDiscardKey.class, IngressDiscardValue.class);
         } catch (ErrnoException e) {
             throw new IllegalStateException("Cannot open ingress discard map", e);
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index bb77a9d..d3b7f79 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -489,6 +489,8 @@
     private final boolean mRequestRestrictedWifiEnabled;
     private final boolean mBackgroundFirewallChainEnabled;
 
+    private final boolean mUseDeclaredMethodsForCallbacksEnabled;
+
     /**
      * Uids ConnectivityService tracks blocked status of to send blocked status callbacks.
      * Key is uid based on mAsUid of registered networkRequestInfo
@@ -1850,6 +1852,8 @@
                 && mDeps.isFeatureEnabled(context, REQUEST_RESTRICTED_WIFI);
         mBackgroundFirewallChainEnabled = mDeps.isAtLeastV() && mDeps.isFeatureNotChickenedOut(
                 context, ConnectivityFlags.BACKGROUND_FIREWALL_CHAIN);
+        mUseDeclaredMethodsForCallbacksEnabled = mDeps.isFeatureEnabled(context,
+                ConnectivityFlags.USE_DECLARED_METHODS_FOR_CALLBACKS);
         mCarrierPrivilegeAuthenticator = mDeps.makeCarrierPrivilegeAuthenticator(
                 mContext, mTelephonyManager, mRequestRestrictedWifiEnabled,
                 this::handleUidCarrierPrivilegesLost, mHandler);
@@ -14045,4 +14049,16 @@
         enforceNetworkStackPermission(mContext);
         return mRoutingCoordinatorService;
     }
+
+    @Override
+    public long getEnabledConnectivityManagerFeatures() {
+        long features = 0;
+        // The bitmask must be built based on final properties initialized in the constructor, to
+        // ensure that it does not change over time and is always consistent between
+        // ConnectivityManager and ConnectivityService.
+        if (mUseDeclaredMethodsForCallbacksEnabled) {
+            features |= ConnectivityManager.FEATURE_USE_DECLARED_METHODS_FOR_CALLBACKS;
+        }
+        return features;
+    }
 }
diff --git a/service/src/com/android/server/connectivity/ConnectivityFlags.java b/service/src/com/android/server/connectivity/ConnectivityFlags.java
index 7ea7f95..1ee1ed7 100644
--- a/service/src/com/android/server/connectivity/ConnectivityFlags.java
+++ b/service/src/com/android/server/connectivity/ConnectivityFlags.java
@@ -46,6 +46,9 @@
 
     public static final String DELAY_DESTROY_SOCKETS = "delay_destroy_sockets";
 
+    public static final String USE_DECLARED_METHODS_FOR_CALLBACKS =
+            "use_declared_methods_for_callbacks";
+
     private boolean mNoRematchAllRequestsOnRegister;
 
     /**
diff --git a/staticlibs/Android.bp b/staticlibs/Android.bp
index ede6d3f..e2834b0 100644
--- a/staticlibs/Android.bp
+++ b/staticlibs/Android.bp
@@ -135,6 +135,7 @@
         "device/com/android/net/module/util/BpfUtils.java",
         "device/com/android/net/module/util/IBpfMap.java",
         "device/com/android/net/module/util/JniUtil.java",
+        "device/com/android/net/module/util/SingleWriterBpfMap.java",
         "device/com/android/net/module/util/TcUtils.java",
     ],
     sdk_version: "module_current",
diff --git a/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java b/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java
new file mode 100644
index 0000000..3eb59d8
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/SingleWriterBpfMap.java
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.net.module.util;
+
+import android.os.Build;
+import android.system.ErrnoException;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
+
+import java.util.HashMap;
+import java.util.NoSuchElementException;
+
+/**
+ * Subclass of BpfMap for maps that are only ever written by one userspace writer.
+ *
+ * This class stores all map data in a userspace HashMap in addition to in the BPF map. This makes
+ * reads (but not iterations) much faster because they do not require a system call or converting
+ * the raw map read to the Value struct. See, e.g., b/343166906 .
+ *
+ * Users of this class must ensure that no BPF program ever writes to the map, and that all
+ * userspace writes to the map occur through this object. Other userspace code may still read from
+ * the map; only writes are required to go through this object.
+ *
+ * Reads and writes to this object are thread-safe and internally synchronized. The read and write
+ * methods are synchronized to ensure that current writers always result in a consistent internal
+ * state (without synchronization, two concurrent writes might update the underlying map and the
+ * cache in the opposite order, resulting in the cache being out of sync with the map).
+ *
+ * getNextKey and iteration over the map are not synchronized or cached and always access the
+ * isunderlying map. The values returned by these calls may be temporarily out of sync with the
+ * values read and written through this object.
+ *
+ * TODO: consider caching reads on iterations as well. This is not trivial because the semantics for
+ * iterating BPF maps require passing in the previously-returned key, and Java iterators only
+ * support iterating from the beginning. It could be done by implementing forEach and possibly by
+ * making getFirstKey and getNextKey private (if no callers are using them). Because HashMap is not
+ * thread-safe, implementing forEach would require either making that method synchronized (and
+ * block reads and updates from other threads until iteration is complete) or switching the
+ * internal HashMap to ConcurrentHashMap.
+ *
+ * @param <K> the key of the map.
+ * @param <V> the value of the map.
+ */
+@RequiresApi(Build.VERSION_CODES.S)
+public class SingleWriterBpfMap<K extends Struct, V extends Struct> extends BpfMap<K, V> {
+    // HashMap instead of ArrayMap because it performs better on larger maps, and many maps used in
+    // our code can contain hundreds of items.
+    private final HashMap<K, V> mCache = new HashMap<>();
+
+    protected SingleWriterBpfMap(@NonNull final String path, final int flag, final Class<K> key,
+            final Class<V> value) throws ErrnoException, NullPointerException {
+        super(path, flag, key, value);
+
+        if (flag != BPF_F_RDWR) {
+            throw new IllegalArgumentException(
+                    "Using " + getClass().getName() + " for read-only maps does not make sense");
+        }
+
+        // Populate cache with the current map contents.
+        K currentKey = super.getFirstKey();
+        while (currentKey != null) {
+            mCache.put(currentKey, super.getValue(currentKey));
+            currentKey = super.getNextKey(currentKey);
+        }
+    }
+
+    public SingleWriterBpfMap(@NonNull final String path, final Class<K> key,
+            final Class<V> value) throws ErrnoException, NullPointerException {
+        this(path, BPF_F_RDWR, key, value);
+    }
+
+    @Override
+    public synchronized void updateEntry(K key, V value) throws ErrnoException {
+        super.updateEntry(key, value);
+        mCache.put(key, value);
+    }
+
+    @Override
+    public synchronized void insertEntry(K key, V value)
+            throws ErrnoException, IllegalStateException {
+        super.insertEntry(key, value);
+        mCache.put(key, value);
+    }
+
+    @Override
+    public synchronized void replaceEntry(K key, V value)
+            throws ErrnoException, NoSuchElementException {
+        super.replaceEntry(key, value);
+        mCache.put(key, value);
+    }
+
+    @Override
+    public synchronized boolean insertOrReplaceEntry(K key, V value) throws ErrnoException {
+        final boolean ret = super.insertOrReplaceEntry(key, value);
+        mCache.put(key, value);
+        return ret;
+    }
+
+    @Override
+    public synchronized boolean deleteEntry(K key) throws ErrnoException {
+        final boolean ret = super.deleteEntry(key);
+        mCache.remove(key);
+        return ret;
+    }
+
+    @Override
+    public synchronized boolean containsKey(@NonNull K key) throws ErrnoException {
+        return mCache.containsKey(key);
+    }
+
+    @Override
+    public synchronized V getValue(@NonNull K key) throws ErrnoException {
+        return mCache.get(key);
+    }
+}
diff --git a/tests/common/java/android/net/NetworkCapabilitiesTest.java b/tests/common/java/android/net/NetworkCapabilitiesTest.java
index 6eb56c7b..0f0e2f1 100644
--- a/tests/common/java/android/net/NetworkCapabilitiesTest.java
+++ b/tests/common/java/android/net/NetworkCapabilitiesTest.java
@@ -61,6 +61,7 @@
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI_AWARE;
 import static android.os.Process.INVALID_UID;
+
 import static com.android.modules.utils.build.SdkLevel.isAtLeastS;
 import static com.android.modules.utils.build.SdkLevel.isAtLeastT;
 import static com.android.modules.utils.build.SdkLevel.isAtLeastV;
@@ -68,6 +69,7 @@
 import static com.android.testutils.MiscAsserts.assertEmpty;
 import static com.android.testutils.MiscAsserts.assertThrows;
 import static com.android.testutils.ParcelUtils.assertParcelingIsLossless;
+
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -83,21 +85,25 @@
 import android.os.Build;
 import android.util.ArraySet;
 import android.util.Range;
+
 import androidx.test.filters.SmallTest;
+
 import com.android.testutils.CompatUtil;
 import com.android.testutils.ConnectivityModuleTest;
 import com.android.testutils.DevSdkIgnoreRule;
 import com.android.testutils.DevSdkIgnoreRule.IgnoreUpTo;
 import com.android.testutils.DevSdkIgnoreRunner;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Set;
+
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mockito;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+
 @SmallTest
 @RunWith(DevSdkIgnoreRunner.class)
 // NetworkCapabilities is only updatable on S+, and this test covers behavior which implementation
@@ -1465,4 +1471,26 @@
         assertEquals("-SUPL-VALIDATED-CAPTIVE_PORTAL+MMS+OEM_PAID",
                 nc1.describeCapsDifferencesFrom(nc2));
     }
+
+    @Test
+    public void testInvalidCapability() {
+        final int invalidCapability = Integer.MAX_VALUE;
+        // Passing invalid capability does not throw
+        final NetworkCapabilities nc1 = new NetworkCapabilities.Builder()
+                .addCapability(NET_CAPABILITY_INTERNET)
+                .addForbiddenCapability(NET_CAPABILITY_NOT_ROAMING)
+                .removeCapability(invalidCapability)
+                .removeForbiddenCapability(invalidCapability)
+                .addCapability(invalidCapability)
+                .addForbiddenCapability(invalidCapability)
+                .build();
+
+        final NetworkCapabilities nc2 = new NetworkCapabilities.Builder()
+                .addCapability(NET_CAPABILITY_INTERNET)
+                .addForbiddenCapability(NET_CAPABILITY_NOT_ROAMING)
+                .build();
+
+        // nc1 and nc2 are the same since invalid capability is ignored
+        assertEquals(nc1, nc2);
+    }
 }
diff --git a/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt b/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt
index 90fb7a9..0b6637d 100644
--- a/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt
+++ b/tests/cts/net/src/android/net/cts/ApfIntegrationTest.kt
@@ -55,6 +55,7 @@
 import com.android.compatibility.common.util.PropertyUtil.getVsrApiLevel
 import com.android.compatibility.common.util.SystemUtil.runShellCommand
 import com.android.compatibility.common.util.SystemUtil.runShellCommandOrThrow
+import com.android.compatibility.common.util.VsrTest
 import com.android.internal.util.HexDump
 import com.android.net.module.util.PacketReader
 import com.android.testutils.DevSdkIgnoreRule
@@ -300,6 +301,10 @@
         }
     }
 
+    @VsrTest(
+        requirements = ["VSR-5.3.12-001", "VSR-5.3.12-003", "VSR-5.3.12-004", "VSR-5.3.12-009",
+            "VSR-5.3.12-012"]
+    )
     @Test
     fun testApfCapabilities() {
         // APF became mandatory in Android 14 VSR.
@@ -350,6 +355,9 @@
         return HexDump.hexStringToByteArray(progHexString)
     }
 
+    @VsrTest(
+            requirements = ["VSR-5.3.12-007", "VSR-5.3.12-008", "VSR-5.3.12-010", "VSR-5.3.12-011"]
+    )
     @SkipPresubmit(reason = "This test takes longer than 1 minute, do not run it on presubmit.")
     // APF integration is mostly broken before V, only run the full read / write test on V+.
     @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
@@ -400,6 +408,7 @@
     }
 
     // APF integration is mostly broken before V
+    @VsrTest(requirements = ["VSR-5.3.12-002", "VSR-5.3.12-005"])
     @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
     @Test
     fun testDropPingReply() {
@@ -448,6 +457,7 @@
     fun clearApfMemory() = installProgram(ByteArray(caps.maximumApfProgramSize))
 
     // APF integration is mostly broken before V
+    @VsrTest(requirements = ["VSR-5.3.12-002", "VSR-5.3.12-005"])
     @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
     @Test
     fun testPrefilledMemorySlotsV4() {
@@ -503,6 +513,7 @@
     }
 
     // APF integration is mostly broken before V
+    @VsrTest(requirements = ["VSR-5.3.12-002", "VSR-5.3.12-005"])
     @IgnoreUpTo(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
     @Test
     fun testFilterAgeIncreasesBetweenPackets() {
diff --git a/tests/unit/java/com/android/server/ConnectivityServiceTest.java b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
index 44a8222..8526a9a 100755
--- a/tests/unit/java/com/android/server/ConnectivityServiceTest.java
+++ b/tests/unit/java/com/android/server/ConnectivityServiceTest.java
@@ -2178,9 +2178,8 @@
             switch (name) {
                 case ConnectivityFlags.NO_REMATCH_ALL_REQUESTS_ON_REGISTER:
                 case ConnectivityFlags.CARRIER_SERVICE_CHANGED_USE_CALLBACK:
-                    return true;
                 case ConnectivityFlags.REQUEST_RESTRICTED_WIFI:
-                    return true;
+                case ConnectivityFlags.USE_DECLARED_METHODS_FOR_CALLBACKS:
                 case KEY_DESTROY_FROZEN_SOCKETS_VERSION:
                     return true;
                 default:
diff --git a/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt b/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt
index 47a6763..ed72fd2 100644
--- a/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt
+++ b/tests/unit/java/com/android/server/connectivityservice/base/CSTest.kt
@@ -164,6 +164,7 @@
         it[ConnectivityFlags.INGRESS_TO_VPN_ADDRESS_FILTERING] = true
         it[ConnectivityFlags.BACKGROUND_FIREWALL_CHAIN] = true
         it[ConnectivityFlags.DELAY_DESTROY_SOCKETS] = true
+        it[ConnectivityFlags.USE_DECLARED_METHODS_FOR_CALLBACKS] = true
     }
     fun setFeatureEnabled(flag: String, enabled: Boolean) = enabledFeatures.set(flag, enabled)
 
diff --git a/thread/tests/cts/AndroidTest.xml b/thread/tests/cts/AndroidTest.xml
index ffc181c..6eda1e9 100644
--- a/thread/tests/cts/AndroidTest.xml
+++ b/thread/tests/cts/AndroidTest.xml
@@ -38,6 +38,11 @@
         <option name="mainline-module-package-name" value="com.google.android.tethering" />
     </object>
 
+    <object type="module_controller"
+            class="com.android.tradefed.testtype.suite.module.DeviceFeatureModuleController">
+        <option name="required-feature" value="android.hardware.thread_network" />
+    </object>
+
     <!-- Install test -->
     <target_preparer class="com.android.tradefed.targetprep.suite.SuiteApkInstaller">
         <option name="test-file-name" value="CtsThreadNetworkTestCases.apk" />
diff --git a/thread/tests/integration/AndroidTest.xml b/thread/tests/integration/AndroidTest.xml
index 152c1c3..8f98941 100644
--- a/thread/tests/integration/AndroidTest.xml
+++ b/thread/tests/integration/AndroidTest.xml
@@ -31,6 +31,11 @@
         <option name="mainline-module-package-name" value="com.google.android.tethering" />
     </object>
 
+    <object type="module_controller"
+            class="com.android.tradefed.testtype.suite.module.DeviceFeatureModuleController">
+        <option name="required-feature" value="android.hardware.thread_network" />
+    </object>
+
     <target_preparer class="com.android.tradefed.targetprep.RootTargetPreparer" />
 
     <!-- Install test -->
diff --git a/thread/tests/unit/AndroidTest.xml b/thread/tests/unit/AndroidTest.xml
index d16e423..58e9bdd 100644
--- a/thread/tests/unit/AndroidTest.xml
+++ b/thread/tests/unit/AndroidTest.xml
@@ -31,6 +31,11 @@
         <option name="mainline-module-package-name" value="com.google.android.tethering" />
     </object>
 
+    <object type="module_controller"
+            class="com.android.tradefed.testtype.suite.module.DeviceFeatureModuleController">
+        <option name="required-feature" value="android.hardware.thread_network" />
+    </object>
+
     <target_preparer class="com.android.tradefed.targetprep.suite.SuiteApkInstaller">
         <option name="test-file-name" value="ThreadNetworkUnitTests.apk" />
         <option name="check-min-sdk" value="true" />