diff --git a/service/src/com/android/metrics/ConnectivitySampleMetricsHelper.java b/service/src/com/android/metrics/ConnectivitySampleMetricsHelper.java
new file mode 100644
index 0000000..93d1d5d
--- /dev/null
+++ b/service/src/com/android/metrics/ConnectivitySampleMetricsHelper.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2023 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.metrics;
+
+import android.annotation.NonNull;
+import android.app.StatsManager;
+import android.content.Context;
+import android.os.Handler;
+import android.util.Log;
+import android.util.StatsEvent;
+
+import com.android.modules.utils.HandlerExecutor;
+
+import java.util.List;
+import java.util.function.Supplier;
+
+/**
+ * A class to register, sample and send connectivity state metrics.
+ */
+public class ConnectivitySampleMetricsHelper implements StatsManager.StatsPullAtomCallback {
+    private static final String TAG = ConnectivitySampleMetricsHelper.class.getSimpleName();
+
+    final Supplier<StatsEvent> mDelegate;
+
+    /**
+     * Start collecting metrics.
+     * @param context some context to get services
+     * @param connectivityServiceHandler the connectivity service handler
+     * @param atomTag the tag to collect metrics from
+     * @param delegate a method returning data when called on the handler thread
+     */
+    // Unfortunately it seems essentially impossible to unit test this method. The only thing
+    // to test is that there is a call to setPullAtomCallback, but StatsManager is final and
+    // can't be mocked without mockito-extended. Using mockito-extended in FrameworksNetTests
+    // would have a very large impact on performance, while splitting the unit test for this
+    // class in a separate target would make testing very hard to manage. Therefore, there
+    // can unfortunately be no unit tests for this method, but at least it is very simple.
+    public static void start(@NonNull final Context context,
+            @NonNull final Handler connectivityServiceHandler,
+            final int atomTag,
+            @NonNull final Supplier<StatsEvent> delegate) {
+        final ConnectivitySampleMetricsHelper metrics =
+                new ConnectivitySampleMetricsHelper(delegate);
+        final StatsManager mgr = context.getSystemService(StatsManager.class);
+        if (null == mgr) return; // No metrics for you
+        mgr.setPullAtomCallback(atomTag, null /* metadata */,
+                new HandlerExecutor(connectivityServiceHandler), metrics);
+    }
+
+    public ConnectivitySampleMetricsHelper(@NonNull final Supplier<StatsEvent> delegate) {
+        mDelegate = delegate;
+    }
+
+    @Override
+    public int onPullAtom(final int atomTag, final List<StatsEvent> data) {
+        Log.d(TAG, "Sampling data for atom : " + atomTag);
+        data.add(mDelegate.get());
+        return StatsManager.PULL_SUCCESS;
+    }
+}
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 6770a8f..85507f6 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -77,6 +77,7 @@
 import static android.net.NetworkCapabilities.NET_CAPABILITY_OEM_PAID;
 import static android.net.NetworkCapabilities.NET_CAPABILITY_OEM_PRIVATE;
 import static android.net.NetworkCapabilities.NET_CAPABILITY_PARTIAL_CONNECTIVITY;
+import static android.net.NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED;
 import static android.net.NetworkCapabilities.NET_CAPABILITY_VALIDATED;
 import static android.net.NetworkCapabilities.NET_ENTERPRISE_ID_1;
 import static android.net.NetworkCapabilities.NET_ENTERPRISE_ID_5;
@@ -102,6 +103,7 @@
 import static com.android.net.module.util.PermissionUtils.enforceAnyPermissionOf;
 import static com.android.net.module.util.PermissionUtils.enforceNetworkStackPermission;
 import static com.android.net.module.util.PermissionUtils.enforceNetworkStackPermissionOr;
+import static com.android.server.ConnectivityStatsLog.CONNECTIVITY_STATE_SAMPLE;
 
 import static java.util.Map.Entry;
 
@@ -235,6 +237,9 @@
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
+import android.stats.connectivity.MeteredState;
+import android.stats.connectivity.RequestType;
+import android.stats.connectivity.ValidatedState;
 import android.sysprop.NetworkProperties;
 import android.system.ErrnoException;
 import android.telephony.TelephonyManager;
@@ -247,6 +252,7 @@
 import android.util.Range;
 import android.util.SparseArray;
 import android.util.SparseIntArray;
+import android.util.StatsEvent;
 
 import androidx.annotation.RequiresApi;
 
@@ -255,6 +261,16 @@
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.IndentingPrintWriter;
 import com.android.internal.util.MessageUtils;
+import com.android.metrics.ConnectionDurationForTransports;
+import com.android.metrics.ConnectionDurationPerTransports;
+import com.android.metrics.ConnectivitySampleMetricsHelper;
+import com.android.metrics.ConnectivityStateSample;
+import com.android.metrics.NetworkCountForTransports;
+import com.android.metrics.NetworkCountPerTransports;
+import com.android.metrics.NetworkDescription;
+import com.android.metrics.NetworkList;
+import com.android.metrics.NetworkRequestCount;
+import com.android.metrics.RequestCountForType;
 import com.android.modules.utils.BasicShellCommandHandler;
 import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
@@ -337,6 +353,7 @@
 import java.util.SortedSet;
 import java.util.StringJoiner;
 import java.util.TreeSet;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
@@ -2340,6 +2357,134 @@
         return out;
     }
 
+    // Because StatsEvent is not usable in tests (everything inside it is hidden), this
+    // method is used to convert a ConnectivityStateSample into a StatsEvent, so that tests
+    // can call sampleConnectivityState and make the checks on it.
+    @NonNull
+    private StatsEvent sampleConnectivityStateToStatsEvent() {
+        final ConnectivityStateSample sample = sampleConnectivityState();
+        return ConnectivityStatsLog.buildStatsEvent(
+                ConnectivityStatsLog.CONNECTIVITY_STATE_SAMPLE,
+                sample.getNetworkCountPerTransports().toByteArray(),
+                sample.getConnectionDurationPerTransports().toByteArray(),
+                sample.getNetworkRequestCount().toByteArray(),
+                sample.getNetworks().toByteArray());
+    }
+
+    /**
+     * Gather and return a snapshot of the current connectivity state, to be used as a sample.
+     *
+     * This is used for metrics. These snapshots will be sampled and constitute a base for
+     * statistics about connectivity state of devices.
+     */
+    @VisibleForTesting
+    @NonNull
+    public ConnectivityStateSample sampleConnectivityState() {
+        ensureRunningOnConnectivityServiceThread();
+        final ConnectivityStateSample.Builder builder = ConnectivityStateSample.newBuilder();
+        builder.setNetworkCountPerTransports(sampleNetworkCount(mNetworkAgentInfos));
+        builder.setConnectionDurationPerTransports(sampleConnectionDuration(mNetworkAgentInfos));
+        builder.setNetworkRequestCount(sampleNetworkRequestCount(mNetworkRequests.values()));
+        builder.setNetworks(sampleNetworks(mNetworkAgentInfos));
+        return builder.build();
+    }
+
+    private static NetworkCountPerTransports sampleNetworkCount(
+            @NonNull final ArraySet<NetworkAgentInfo> nais) {
+        final SparseIntArray countPerTransports = new SparseIntArray();
+        for (final NetworkAgentInfo nai : nais) {
+            int transports = (int) nai.networkCapabilities.getTransportTypesInternal();
+            countPerTransports.put(transports, 1 + countPerTransports.get(transports, 0));
+        }
+        final NetworkCountPerTransports.Builder builder = NetworkCountPerTransports.newBuilder();
+        for (int i = countPerTransports.size() - 1; i >= 0; --i) {
+            final NetworkCountForTransports.Builder c = NetworkCountForTransports.newBuilder();
+            c.setTransportTypes(countPerTransports.keyAt(i));
+            c.setNetworkCount(countPerTransports.valueAt(i));
+            builder.addNetworkCountForTransports(c);
+        }
+        return builder.build();
+    }
+
+    private static ConnectionDurationPerTransports sampleConnectionDuration(
+            @NonNull final ArraySet<NetworkAgentInfo> nais) {
+        final ConnectionDurationPerTransports.Builder builder =
+                ConnectionDurationPerTransports.newBuilder();
+        for (final NetworkAgentInfo nai : nais) {
+            final ConnectionDurationForTransports.Builder c =
+                    ConnectionDurationForTransports.newBuilder();
+            c.setTransportTypes((int) nai.networkCapabilities.getTransportTypesInternal());
+            final long durationMillis = SystemClock.elapsedRealtime() - nai.getConnectedTime();
+            final long millisPerSecond = TimeUnit.SECONDS.toMillis(1);
+            // Add millisPerSecond/2 to round up or down to the nearest value
+            c.setDurationSec((int) ((durationMillis + millisPerSecond / 2) / millisPerSecond));
+            builder.addConnectionDurationForTransports(c);
+        }
+        return builder.build();
+    }
+
+    private static NetworkRequestCount sampleNetworkRequestCount(
+            @NonNull final Collection<NetworkRequestInfo> nris) {
+        final NetworkRequestCount.Builder builder = NetworkRequestCount.newBuilder();
+        final SparseIntArray countPerType = new SparseIntArray();
+        for (final NetworkRequestInfo nri : nris) {
+            final int type;
+            if (Process.SYSTEM_UID == nri.mAsUid) {
+                // The request is filed "as" the system, so it's the system on its own behalf.
+                type = RequestType.RT_SYSTEM.getNumber();
+            } else if (Process.SYSTEM_UID == nri.mUid) {
+                // The request is filed by the system as some other app, so it's the system on
+                // behalf of an app.
+                type = RequestType.RT_SYSTEM_ON_BEHALF_OF_APP.getNumber();
+            } else {
+                // Not the system, so it's an app requesting on its own behalf.
+                type = RequestType.RT_APP.getNumber();
+            }
+            countPerType.put(type, countPerType.get(type, 0));
+        }
+        for (int i = countPerType.size() - 1; i >= 0; --i) {
+            final RequestCountForType.Builder r = RequestCountForType.newBuilder();
+            r.setRequestType(RequestType.forNumber(countPerType.keyAt(i)));
+            r.setRequestCount(countPerType.valueAt(i));
+            builder.addRequestCountForType(r);
+        }
+        return builder.build();
+    }
+
+    private static NetworkList sampleNetworks(@NonNull final ArraySet<NetworkAgentInfo> nais) {
+        final NetworkList.Builder builder = NetworkList.newBuilder();
+        for (final NetworkAgentInfo nai : nais) {
+            final NetworkCapabilities nc = nai.networkCapabilities;
+            final NetworkDescription.Builder d = NetworkDescription.newBuilder();
+            d.setTransportTypes((int) nc.getTransportTypesInternal());
+            final MeteredState meteredState;
+            if (nc.hasCapability(NET_CAPABILITY_TEMPORARILY_NOT_METERED)) {
+                meteredState = MeteredState.METERED_TEMPORARILY_UNMETERED;
+            } else if (nc.hasCapability(NET_CAPABILITY_NOT_METERED)) {
+                meteredState = MeteredState.METERED_NO;
+            } else {
+                meteredState = MeteredState.METERED_YES;
+            }
+            d.setMeteredState(meteredState);
+            final ValidatedState validatedState;
+            if (nc.hasCapability(NET_CAPABILITY_CAPTIVE_PORTAL)) {
+                validatedState = ValidatedState.VS_PORTAL;
+            } else if (nc.hasCapability(NET_CAPABILITY_PARTIAL_CONNECTIVITY)) {
+                validatedState = ValidatedState.VS_PARTIAL;
+            } else if (nc.hasCapability(NET_CAPABILITY_VALIDATED)) {
+                validatedState = ValidatedState.VS_VALID;
+            } else {
+                validatedState = ValidatedState.VS_INVALID;
+            }
+            d.setValidatedState(validatedState);
+            d.setScorePolicies(nai.getScore().getPoliciesInternal());
+            d.setCapabilities(nc.getCapabilitiesInternal());
+            d.setEnterpriseId(nc.getEnterpriseIdsInternal());
+            builder.addNetworkDescription(d);
+        }
+        return builder.build();
+    }
+
     @Override
     public boolean isNetworkSupported(int networkType) {
         enforceAccessPermission();
@@ -3453,6 +3598,8 @@
         if (mDeps.isAtLeastT()) {
             mBpfNetMaps.setPullAtomCallback(mContext);
         }
+        ConnectivitySampleMetricsHelper.start(mContext, mHandler,
+                CONNECTIVITY_STATE_SAMPLE, this::sampleConnectivityStateToStatsEvent);
         // Wait PermissionMonitor to finish the permission update. Then MultipathPolicyTracker won't
         // have permission problem. While CV#block() is unbounded in time and can in principle block
         // forever, this replaces a synchronous call to PermissionMonitor#startMonitoring, which
diff --git a/service/src/com/android/server/connectivity/FullScore.java b/service/src/com/android/server/connectivity/FullScore.java
index 87ae0c9..648f3bf 100644
--- a/service/src/com/android/server/connectivity/FullScore.java
+++ b/service/src/com/android/server/connectivity/FullScore.java
@@ -124,7 +124,7 @@
             new Class[]{FullScore.class, NetworkScore.class}, new String[]{"POLICY_"});
 
     @VisibleForTesting
-    static @NonNull String policyNameOf(final int policy) {
+    public static @NonNull String policyNameOf(final int policy) {
         final String name = sMessageNames.get(policy);
         if (name == null) {
             // Don't throw here because name might be null due to proguard stripping out the
@@ -304,6 +304,18 @@
     }
 
     /**
+     * Gets the policies as an long. Internal callers only.
+     *
+     * DO NOT USE if not immediately collapsing back into a scalar. Instead, use
+     * {@link #hasPolicy}.
+     * @return the internal, version-dependent int representing the policies.
+     * @hide
+     */
+    public long getPoliciesInternal() {
+        return mPolicies;
+    }
+
+    /**
      * @return whether this score has a particular policy.
      */
     @VisibleForTesting
diff --git a/service/src/com/android/server/connectivity/NetworkAgentInfo.java b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
index 845c04c..bdd841f 100644
--- a/service/src/com/android/server/connectivity/NetworkAgentInfo.java
+++ b/service/src/com/android/server/connectivity/NetworkAgentInfo.java
@@ -1105,6 +1105,11 @@
      *         already present.
      */
     public boolean addRequest(NetworkRequest networkRequest) {
+        if (mHandler.getLooper().getThread() != Thread.currentThread()) {
+            throw new IllegalStateException(
+                    "Not running on ConnectivityService thread: "
+                            + Thread.currentThread().getName());
+        }
         NetworkRequest existing = mNetworkRequests.get(networkRequest.requestId);
         if (existing == networkRequest) return false;
         if (existing != null) {
@@ -1123,6 +1128,11 @@
      * Remove the specified request from this network.
      */
     public void removeRequest(int requestId) {
+        if (mHandler.getLooper().getThread() != Thread.currentThread()) {
+            throw new IllegalStateException(
+                    "Not running on ConnectivityService thread: "
+                            + Thread.currentThread().getName());
+        }
         NetworkRequest existing = mNetworkRequests.get(requestId);
         if (existing == null) return;
         updateRequestCounts(REMOVE, existing);
@@ -1144,6 +1154,11 @@
      * network.
      */
     public NetworkRequest requestAt(int index) {
+        if (mHandler.getLooper().getThread() != Thread.currentThread()) {
+            throw new IllegalStateException(
+                    "Not running on ConnectivityService thread: "
+                            + Thread.currentThread().getName());
+        }
         return mNetworkRequests.valueAt(index);
     }
 
@@ -1174,6 +1189,11 @@
      * Returns the number of requests of any type currently satisfied by this network.
      */
     public int numNetworkRequests() {
+        if (mHandler.getLooper().getThread() != Thread.currentThread()) {
+            throw new IllegalStateException(
+                    "Not running on ConnectivityService thread: "
+                            + Thread.currentThread().getName());
+        }
         return mNetworkRequests.size();
     }