diff --git a/core/java/android/net/INetworkStatsService.aidl b/core/java/android/net/INetworkStatsService.aidl
index 381cfb61de..8e6f272388 100644
--- a/core/java/android/net/INetworkStatsService.aidl
+++ b/core/java/android/net/INetworkStatsService.aidl
@@ -41,6 +41,16 @@ interface INetworkStatsService {
 
     /** Return data layer snapshot of UID network usage. */
     NetworkStats getDataLayerSnapshotForUid(int uid);
+
+    /** Get a detailed snapshot of stats since boot for all UIDs.
+    *
+    * <p>Results will not always be limited to stats on requiredIfaces when specified: stats for
+    * interfaces stacked on the specified interfaces, or for interfaces on which the specified
+    * interfaces are stacked on, will also be included.
+    * @param requiredIfaces Interface names to get data for, or {@link NetworkStats#INTERFACES_ALL}.
+    */
+    NetworkStats getDetailedUidStats(in String[] requiredIfaces);
+
     /** Return set of any ifaces associated with mobile networks since boot. */
     String[] getMobileIfaces();
 
diff --git a/core/java/android/net/NetworkStats.java b/core/java/android/net/NetworkStats.java
index 16fb858a58..292bf8e196 100644
--- a/core/java/android/net/NetworkStats.java
+++ b/core/java/android/net/NetworkStats.java
@@ -64,6 +64,9 @@ public class NetworkStats implements Parcelable {
     /** Debug {@link #set} value when the VPN stats are moved out of a vpn UID. */
     public static final int SET_DBG_VPN_OUT = 1002;
 
+    /** Include all interfaces when filtering */
+    public static final String[] INTERFACES_ALL = null;
+
     /** {@link #tag} value for total data across all tags. */
     // TODO: Rename TAG_NONE to TAG_ALL.
     public static final int TAG_NONE = 0;
@@ -366,23 +369,27 @@ public class NetworkStats implements Parcelable {
             capacity = newLength;
         }
 
-        iface[size] = entry.iface;
-        uid[size] = entry.uid;
-        set[size] = entry.set;
-        tag[size] = entry.tag;
-        metered[size] = entry.metered;
-        roaming[size] = entry.roaming;
-        defaultNetwork[size] = entry.defaultNetwork;
-        rxBytes[size] = entry.rxBytes;
-        rxPackets[size] = entry.rxPackets;
-        txBytes[size] = entry.txBytes;
-        txPackets[size] = entry.txPackets;
-        operations[size] = entry.operations;
+        setValues(size, entry);
         size++;
 
         return this;
     }
 
+    private void setValues(int i, Entry entry) {
+        iface[i] = entry.iface;
+        uid[i] = entry.uid;
+        set[i] = entry.set;
+        tag[i] = entry.tag;
+        metered[i] = entry.metered;
+        roaming[i] = entry.roaming;
+        defaultNetwork[i] = entry.defaultNetwork;
+        rxBytes[i] = entry.rxBytes;
+        rxPackets[i] = entry.rxPackets;
+        txBytes[i] = entry.txBytes;
+        txPackets[i] = entry.txPackets;
+        operations[i] = entry.operations;
+    }
+
     /**
      * Return specific stats entry.
      */
@@ -831,6 +838,39 @@ public class NetworkStats implements Parcelable {
         return stats;
     }
 
+    /**
+     * Only keep entries that match all specified filters.
+     *
+     * <p>This mutates the original structure in place. After this method is called,
+     * size is the number of matching entries, and capacity is the previous capacity.
+     * @param limitUid UID to filter for, or {@link #UID_ALL}.
+     * @param limitIfaces Interfaces to filter for, or {@link #INTERFACES_ALL}.
+     * @param limitTag Tag to filter for, or {@link #TAG_ALL}.
+     */
+    public void filter(int limitUid, String[] limitIfaces, int limitTag) {
+        if (limitUid == UID_ALL && limitTag == TAG_ALL && limitIfaces == INTERFACES_ALL) {
+            return;
+        }
+
+        Entry entry = new Entry();
+        int nextOutputEntry = 0;
+        for (int i = 0; i < size; i++) {
+            entry = getValues(i, entry);
+            final boolean matches =
+                    (limitUid == UID_ALL || limitUid == entry.uid)
+                    && (limitTag == TAG_ALL || limitTag == entry.tag)
+                    && (limitIfaces == INTERFACES_ALL
+                            || ArrayUtils.contains(limitIfaces, entry.iface));
+
+            if (matches) {
+                setValues(nextOutputEntry, entry);
+                nextOutputEntry++;
+            }
+        }
+
+        size = nextOutputEntry;
+    }
+
     public void dump(String prefix, PrintWriter pw) {
         pw.print(prefix);
         pw.print("NetworkStats: elapsedRealtime="); pw.println(elapsedRealtime);
diff --git a/core/java/com/android/internal/net/NetworkStatsFactory.java b/core/java/com/android/internal/net/NetworkStatsFactory.java
index 43abadec0d..0cf5375076 100644
--- a/core/java/com/android/internal/net/NetworkStatsFactory.java
+++ b/core/java/com/android/internal/net/NetworkStatsFactory.java
@@ -22,16 +22,14 @@ import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
 import static com.android.server.NetworkManagementSocketTagger.kernelToTag;
 
+import android.annotation.Nullable;
 import android.net.NetworkStats;
 import android.os.StrictMode;
 import android.os.SystemClock;
-import android.util.ArrayMap;
 
-import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.ProcFileReader;
-import com.google.android.collect.Lists;
 
 import libcore.io.IoUtils;
 
@@ -41,8 +39,10 @@ import java.io.FileInputStream;
 import java.io.FileReader;
 import java.io.IOException;
 import java.net.ProtocolException;
-import java.util.ArrayList;
-import java.util.Objects;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Creates {@link NetworkStats} instances by parsing various {@code /proc/}
@@ -72,18 +72,55 @@ public class NetworkStatsFactory {
 
     private boolean mUseBpfStats;
 
-    // TODO: to improve testability and avoid global state, do not use a static variable.
-    @GuardedBy("sStackedIfaces")
-    private static final ArrayMap<String, String> sStackedIfaces = new ArrayMap<>();
+    // TODO: only do adjustments in NetworkStatsService and remove this.
+    /**
+     * (Stacked interface) -> (base interface) association for all connected ifaces since boot.
+     *
+     * Because counters must never roll backwards, once a given interface is stacked on top of an
+     * underlying interface, the stacked interface can never be stacked on top of
+     * another interface. */
+    private static final ConcurrentHashMap<String, String> sStackedIfaces
+            = new ConcurrentHashMap<>();
 
     public static void noteStackedIface(String stackedIface, String baseIface) {
-        synchronized (sStackedIfaces) {
-            if (baseIface != null) {
-                sStackedIfaces.put(stackedIface, baseIface);
-            } else {
-                sStackedIfaces.remove(stackedIface);
+        if (stackedIface != null && baseIface != null) {
+            sStackedIfaces.put(stackedIface, baseIface);
+        }
+    }
+
+    /**
+     * Get a set of interfaces containing specified ifaces and stacked interfaces.
+     *
+     * <p>The added stacked interfaces are ifaces stacked on top of the specified ones, or ifaces
+     * on which the specified ones are stacked. Stacked interfaces are those noted with
+     * {@link #noteStackedIface(String, String)}, but only interfaces noted before this method
+     * is called are guaranteed to be included.
+     */
+    public static String[] augmentWithStackedInterfacesLocked(@Nullable String[] requiredIfaces) {
+        if (requiredIfaces == NetworkStats.INTERFACES_ALL) {
+            return null;
+        }
+
+        HashSet<String> relatedIfaces = new HashSet<>(Arrays.asList(requiredIfaces));
+        // ConcurrentHashMap's EntrySet iterators are "guaranteed to traverse
+        // elements as they existed upon construction exactly once, and may
+        // (but are not guaranteed to) reflect any modifications subsequent to construction".
+        // This is enough here.
+        for (Map.Entry<String, String> entry : sStackedIfaces.entrySet()) {
+            if (relatedIfaces.contains(entry.getKey())) {
+                relatedIfaces.add(entry.getValue());
+            } else if (relatedIfaces.contains(entry.getValue())) {
+                relatedIfaces.add(entry.getKey());
             }
         }
+
+        String[] outArray = new String[relatedIfaces.size()];
+        return relatedIfaces.toArray(outArray);
+    }
+
+    @VisibleForTesting
+    public static void clearStackedIfaces() {
+        sStackedIfaces.clear();
     }
 
     public NetworkStatsFactory() {
@@ -252,12 +289,9 @@ public class NetworkStatsFactory {
             NetworkStats lastStats) throws IOException {
         final NetworkStats stats =
               readNetworkStatsDetailInternal(limitUid, limitIfaces, limitTag, lastStats);
-        final ArrayMap<String, String> stackedIfaces;
-        synchronized (sStackedIfaces) {
-            stackedIfaces = new ArrayMap<>(sStackedIfaces);
-        }
         // Total 464xlat traffic to subtract from uid 0 on all base interfaces.
-        final NetworkStats adjustments = new NetworkStats(0, stackedIfaces.size());
+        // sStackedIfaces may grow afterwards, but NetworkStats will just be resized automatically.
+        final NetworkStats adjustments = new NetworkStats(0, sStackedIfaces.size());
 
         NetworkStats.Entry entry = null; // For recycling
 
@@ -271,7 +305,7 @@ public class NetworkStatsFactory {
             if (entry.iface == null || !entry.iface.startsWith(CLATD_INTERFACE_PREFIX)) {
                 continue;
             }
-            final String baseIface = stackedIfaces.get(entry.iface);
+            final String baseIface = sStackedIfaces.get(entry.iface);
             if (baseIface == null) {
                 continue;
             }
diff --git a/services/core/java/com/android/server/net/NetworkStatsService.java b/services/core/java/com/android/server/net/NetworkStatsService.java
index 93c04fe206..57828ca5dc 100644
--- a/services/core/java/com/android/server/net/NetworkStatsService.java
+++ b/services/core/java/com/android/server/net/NetworkStatsService.java
@@ -27,6 +27,7 @@ import static android.net.ConnectivityManager.ACTION_TETHER_STATE_CHANGED;
 import static android.net.ConnectivityManager.isNetworkTypeMobile;
 import static android.net.NetworkStats.DEFAULT_NETWORK_ALL;
 import static android.net.NetworkStats.IFACE_ALL;
+import static android.net.NetworkStats.INTERFACES_ALL;
 import static android.net.NetworkStats.METERED_ALL;
 import static android.net.NetworkStats.ROAMING_ALL;
 import static android.net.NetworkStats.SET_ALL;
@@ -34,6 +35,7 @@ import static android.net.NetworkStats.SET_DEFAULT;
 import static android.net.NetworkStats.SET_FOREGROUND;
 import static android.net.NetworkStats.STATS_PER_IFACE;
 import static android.net.NetworkStats.STATS_PER_UID;
+import static android.net.NetworkStats.TAG_ALL;
 import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
 import static android.net.NetworkStatsHistory.FIELD_ALL;
@@ -127,6 +129,7 @@ import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.net.NetworkStatsFactory;
 import com.android.internal.net.VpnInfo;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.DumpUtils;
@@ -145,6 +148,7 @@ import java.time.ZoneOffset;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Collect and persist detailed network statistics, and provide this data to
@@ -739,7 +743,8 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         final long token = Binder.clearCallingIdentity();
         final NetworkStats networkLayer;
         try {
-            networkLayer = mNetworkManager.getNetworkStatsUidDetail(uid);
+            networkLayer = mNetworkManager.getNetworkStatsUidDetail(uid,
+                    NetworkStats.INTERFACES_ALL);
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -760,6 +765,18 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         return dataLayer;
     }
 
+    @Override
+    public NetworkStats getDetailedUidStats(String[] requiredIfaces) {
+        try {
+            final String[] ifacesToQuery =
+                    NetworkStatsFactory.augmentWithStackedInterfacesLocked(requiredIfaces);
+            return getNetworkStatsUidDetail(ifacesToQuery);
+        } catch (RemoteException e) {
+            Log.wtf(TAG, "Error compiling UID stats", e);
+            return new NetworkStats(0L, 0);
+        }
+    }
+
     @Override
     public String[] getMobileIfaces() {
         return mMobileIfaces;
@@ -1119,6 +1136,8 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
                         if (isMobile) {
                             mobileIfaces.add(stackedIface);
                         }
+
+                        NetworkStatsFactory.noteStackedIface(stackedIface, baseIface);
                     }
                 }
             }
@@ -1141,7 +1160,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     private void recordSnapshotLocked(long currentTime) throws RemoteException {
         // snapshot and record current counters; read UID stats first to
         // avoid over counting dev stats.
-        final NetworkStats uidSnapshot = getNetworkStatsUidDetail();
+        final NetworkStats uidSnapshot = getNetworkStatsUidDetail(INTERFACES_ALL);
         final NetworkStats xtSnapshot = getNetworkStatsXt();
         final NetworkStats devSnapshot = mNetworkManager.getNetworkStatsSummaryDev();
 
@@ -1501,12 +1520,19 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
      * Return snapshot of current UID statistics, including any
      * {@link TrafficStats#UID_TETHERING}, video calling data usage, and {@link #mUidOperations}
      * values.
+     *
+     * @param ifaces A list of interfaces the stats should be restricted to, or
+     *               {@link NetworkStats#INTERFACES_ALL}.
      */
-    private NetworkStats getNetworkStatsUidDetail() throws RemoteException {
-        final NetworkStats uidSnapshot = mNetworkManager.getNetworkStatsUidDetail(UID_ALL);
+    private NetworkStats getNetworkStatsUidDetail(String[] ifaces)
+            throws RemoteException {
+
+        final NetworkStats uidSnapshot = mNetworkManager.getNetworkStatsUidDetail(UID_ALL,
+                ifaces);
 
         // fold tethering stats and operations into uid snapshot
         final NetworkStats tetherSnapshot = getNetworkStatsTethering(STATS_PER_UID);
+        tetherSnapshot.filter(UID_ALL, ifaces, TAG_ALL);
         uidSnapshot.combineAllValues(tetherSnapshot);
 
         final TelephonyManager telephonyManager = (TelephonyManager) mContext.getSystemService(
@@ -1515,10 +1541,14 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         // fold video calling data usage stats into uid snapshot
         final NetworkStats vtStats = telephonyManager.getVtDataUsage(STATS_PER_UID);
         if (vtStats != null) {
+            vtStats.filter(UID_ALL, ifaces, TAG_ALL);
             uidSnapshot.combineAllValues(vtStats);
         }
+
         uidSnapshot.combineAllValues(mUidOperations);
 
+        // TODO: apply tethering & VC 464xlat adjustments here
+
         return uidSnapshot;
     }