[automerger skipped] DO NOT MERGE - Merge Pie Bonito/Sargo into master. am: e963030676 -s ours
am: bd1a8961e2 -s ours
am skip reason: subject contains skip directive

Change-Id: I862d40111b2e525e5838bf09e169c8c3f416633b
diff --git a/core/java/android/net/DataUsageRequest.java b/core/java/android/net/DataUsageRequest.java
index ac9a5a3..0ac8f7e 100644
--- a/core/java/android/net/DataUsageRequest.java
+++ b/core/java/android/net/DataUsageRequest.java
@@ -69,7 +69,7 @@
         dest.writeLong(thresholdInBytes);
     }
 
-    public static final Creator<DataUsageRequest> CREATOR =
+    public static final @android.annotation.NonNull Creator<DataUsageRequest> CREATOR =
             new Creator<DataUsageRequest>() {
                 @Override
                 public DataUsageRequest createFromParcel(Parcel in) {
diff --git a/core/java/android/net/IpSecAlgorithm.java b/core/java/android/net/IpSecAlgorithm.java
index 8034bb6..38d9883 100644
--- a/core/java/android/net/IpSecAlgorithm.java
+++ b/core/java/android/net/IpSecAlgorithm.java
@@ -191,7 +191,7 @@
     }
 
     /** Parcelable Creator */
-    public static final Parcelable.Creator<IpSecAlgorithm> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<IpSecAlgorithm> CREATOR =
             new Parcelable.Creator<IpSecAlgorithm>() {
                 public IpSecAlgorithm createFromParcel(Parcel in) {
                     final String name = in.readString();
diff --git a/core/java/android/net/IpSecConfig.java b/core/java/android/net/IpSecConfig.java
index 3552655..a64014f 100644
--- a/core/java/android/net/IpSecConfig.java
+++ b/core/java/android/net/IpSecConfig.java
@@ -322,7 +322,7 @@
         return strBuilder.toString();
     }
 
-    public static final Parcelable.Creator<IpSecConfig> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<IpSecConfig> CREATOR =
             new Parcelable.Creator<IpSecConfig>() {
                 public IpSecConfig createFromParcel(Parcel in) {
                     return new IpSecConfig(in);
diff --git a/core/java/android/net/IpSecManager.java b/core/java/android/net/IpSecManager.java
index 889e9bc..83813da 100644
--- a/core/java/android/net/IpSecManager.java
+++ b/core/java/android/net/IpSecManager.java
@@ -19,10 +19,13 @@
 
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.RequiresFeature;
 import android.annotation.RequiresPermission;
+import android.annotation.SystemApi;
 import android.annotation.SystemService;
 import android.annotation.TestApi;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.os.Binder;
 import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
@@ -720,6 +723,7 @@
      * to create Network objects which are accessible to the Android system.
      * @hide
      */
+    @SystemApi
     public static final class IpSecTunnelInterface implements AutoCloseable {
         private final String mOpPackageName;
         private final IIpSecService mService;
@@ -746,6 +750,8 @@
          * @param prefixLen length of the InetAddress prefix
          * @hide
          */
+        @SystemApi
+        @RequiresFeature(PackageManager.FEATURE_IPSEC_TUNNELS)
         @RequiresPermission(android.Manifest.permission.MANAGE_IPSEC_TUNNELS)
         public void addAddress(@NonNull InetAddress address, int prefixLen) throws IOException {
             try {
@@ -767,6 +773,8 @@
          * @param prefixLen length of the InetAddress prefix
          * @hide
          */
+        @SystemApi
+        @RequiresFeature(PackageManager.FEATURE_IPSEC_TUNNELS)
         @RequiresPermission(android.Manifest.permission.MANAGE_IPSEC_TUNNELS)
         public void removeAddress(@NonNull InetAddress address, int prefixLen) throws IOException {
             try {
@@ -880,7 +888,9 @@
      * @throws ResourceUnavailableException indicating that too many encapsulation sockets are open
      * @hide
      */
+    @SystemApi
     @NonNull
+    @RequiresFeature(PackageManager.FEATURE_IPSEC_TUNNELS)
     @RequiresPermission(android.Manifest.permission.MANAGE_IPSEC_TUNNELS)
     public IpSecTunnelInterface createIpSecTunnelInterface(@NonNull InetAddress localAddress,
             @NonNull InetAddress remoteAddress, @NonNull Network underlyingNetwork)
@@ -910,6 +920,8 @@
      *         layer failure.
      * @hide
      */
+    @SystemApi
+    @RequiresFeature(PackageManager.FEATURE_IPSEC_TUNNELS)
     @RequiresPermission(android.Manifest.permission.MANAGE_IPSEC_TUNNELS)
     public void applyTunnelModeTransform(@NonNull IpSecTunnelInterface tunnel,
             @PolicyDirection int direction, @NonNull IpSecTransform transform) throws IOException {
diff --git a/core/java/android/net/IpSecSpiResponse.java b/core/java/android/net/IpSecSpiResponse.java
index 71dfa03..f99e570 100644
--- a/core/java/android/net/IpSecSpiResponse.java
+++ b/core/java/android/net/IpSecSpiResponse.java
@@ -65,7 +65,7 @@
         spi = in.readInt();
     }
 
-    public static final Parcelable.Creator<IpSecSpiResponse> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<IpSecSpiResponse> CREATOR =
             new Parcelable.Creator<IpSecSpiResponse>() {
                 public IpSecSpiResponse createFromParcel(Parcel in) {
                     return new IpSecSpiResponse(in);
diff --git a/core/java/android/net/IpSecTransform.java b/core/java/android/net/IpSecTransform.java
index a12df28..36111f2 100644
--- a/core/java/android/net/IpSecTransform.java
+++ b/core/java/android/net/IpSecTransform.java
@@ -21,8 +21,11 @@
 
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.RequiresFeature;
 import android.annotation.RequiresPermission;
+import android.annotation.SystemApi;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.IBinder;
@@ -480,7 +483,9 @@
          * @throws IOException indicating other errors
          * @hide
          */
+        @SystemApi
         @NonNull
+        @RequiresFeature(PackageManager.FEATURE_IPSEC_TUNNELS)
         @RequiresPermission(android.Manifest.permission.MANAGE_IPSEC_TUNNELS)
         public IpSecTransform buildTunnelModeTransform(
                 @NonNull InetAddress sourceAddress,
diff --git a/core/java/android/net/IpSecTransformResponse.java b/core/java/android/net/IpSecTransformResponse.java
index cfc1762..a384889 100644
--- a/core/java/android/net/IpSecTransformResponse.java
+++ b/core/java/android/net/IpSecTransformResponse.java
@@ -60,7 +60,7 @@
         resourceId = in.readInt();
     }
 
-    public static final Parcelable.Creator<IpSecTransformResponse> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<IpSecTransformResponse> CREATOR =
             new Parcelable.Creator<IpSecTransformResponse>() {
                 public IpSecTransformResponse createFromParcel(Parcel in) {
                     return new IpSecTransformResponse(in);
diff --git a/core/java/android/net/IpSecTunnelInterfaceResponse.java b/core/java/android/net/IpSecTunnelInterfaceResponse.java
index c23d831..e3411e0 100644
--- a/core/java/android/net/IpSecTunnelInterfaceResponse.java
+++ b/core/java/android/net/IpSecTunnelInterfaceResponse.java
@@ -65,7 +65,7 @@
         interfaceName = in.readString();
     }
 
-    public static final Parcelable.Creator<IpSecTunnelInterfaceResponse> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<IpSecTunnelInterfaceResponse> CREATOR =
             new Parcelable.Creator<IpSecTunnelInterfaceResponse>() {
                 public IpSecTunnelInterfaceResponse createFromParcel(Parcel in) {
                     return new IpSecTunnelInterfaceResponse(in);
diff --git a/core/java/android/net/IpSecUdpEncapResponse.java b/core/java/android/net/IpSecUdpEncapResponse.java
index 4679267..4e7ba9b 100644
--- a/core/java/android/net/IpSecUdpEncapResponse.java
+++ b/core/java/android/net/IpSecUdpEncapResponse.java
@@ -83,7 +83,7 @@
         fileDescriptor = in.readParcelable(ParcelFileDescriptor.class.getClassLoader());
     }
 
-    public static final Parcelable.Creator<IpSecUdpEncapResponse> CREATOR =
+    public static final @android.annotation.NonNull Parcelable.Creator<IpSecUdpEncapResponse> CREATOR =
             new Parcelable.Creator<IpSecUdpEncapResponse>() {
                 public IpSecUdpEncapResponse createFromParcel(Parcel in) {
                     return new IpSecUdpEncapResponse(in);
diff --git a/core/java/android/net/NetworkStats.java b/core/java/android/net/NetworkStats.java
index 27e0414..e892b65 100644
--- a/core/java/android/net/NetworkStats.java
+++ b/core/java/android/net/NetworkStats.java
@@ -18,7 +18,6 @@
 
 import static android.os.Process.CLAT_UID;
 
-import android.annotation.NonNull;
 import android.annotation.UnsupportedAppUsage;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -34,7 +33,6 @@
 import java.io.CharArrayWriter;
 import java.io.PrintWriter;
 import java.util.Arrays;
-import java.util.function.Predicate;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Objects;
@@ -995,33 +993,23 @@
         if (limitUid == UID_ALL && limitTag == TAG_ALL && limitIfaces == INTERFACES_ALL) {
             return;
         }
-        filter(e -> (limitUid == UID_ALL || limitUid == e.uid)
-            && (limitTag == TAG_ALL || limitTag == e.tag)
-            && (limitIfaces == INTERFACES_ALL
-                    || ArrayUtils.contains(limitIfaces, e.iface)));
-    }
 
-    /**
-     * Only keep entries with {@link #set} value less than {@link #SET_DEBUG_START}.
-     *
-     * <p>This mutates the original structure in place.
-     */
-    public void filterDebugEntries() {
-        filter(e -> e.set < SET_DEBUG_START);
-    }
-
-    private void filter(Predicate<Entry> predicate) {
         Entry entry = new Entry();
         int nextOutputEntry = 0;
         for (int i = 0; i < size; i++) {
             entry = getValues(i, entry);
-            if (predicate.test(entry)) {
-                if (nextOutputEntry != i) {
-                    setValues(nextOutputEntry, 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;
     }
 
@@ -1165,7 +1153,7 @@
     }
 
     @UnsupportedAppUsage
-    public static final Creator<NetworkStats> CREATOR = new Creator<NetworkStats>() {
+    public static final @android.annotation.NonNull Creator<NetworkStats> CREATOR = new Creator<NetworkStats>() {
         @Override
         public NetworkStats createFromParcel(Parcel in) {
             return new NetworkStats(in);
@@ -1187,217 +1175,133 @@
     /**
      * VPN accounting. Move some VPN's underlying traffic to other UIDs that use tun0 iface.
      *
-     * <p>This method should only be called on delta NetworkStats. Do not call this method on a
-     * snapshot {@link NetworkStats} object because the tunUid and/or the underlyingIface may change
-     * over time.
+     * This method should only be called on delta NetworkStats. Do not call this method on a
+     * snapshot {@link NetworkStats} object because the tunUid and/or the underlyingIface may
+     * change over time.
      *
-     * <p>This method performs adjustments for one active VPN package and one VPN iface at a time.
+     * This method performs adjustments for one active VPN package and one VPN iface at a time.
+     *
+     * It is possible for the VPN software to use multiple underlying networks. This method
+     * only migrates traffic for the primary underlying network.
      *
      * @param tunUid uid of the VPN application
      * @param tunIface iface of the vpn tunnel
-     * @param underlyingIfaces underlying network ifaces used by the VPN application
+     * @param underlyingIface the primary underlying network iface used by the VPN application
+     * @return true if it successfully adjusts the accounting for VPN, false otherwise
      */
-    public void migrateTun(int tunUid, @NonNull String tunIface,
-            @NonNull String[] underlyingIfaces) {
-        // Combined usage by all apps using VPN.
-        final Entry tunIfaceTotal = new Entry();
-        // Usage by VPN, grouped by its {@code underlyingIfaces}.
-        final Entry[] perInterfaceTotal = new Entry[underlyingIfaces.length];
-        // Usage by VPN, summed across all its {@code underlyingIfaces}.
-        final Entry underlyingIfacesTotal = new Entry();
+    public boolean migrateTun(int tunUid, String tunIface, String underlyingIface) {
+        Entry tunIfaceTotal = new Entry();
+        Entry underlyingIfaceTotal = new Entry();
 
-        for (int i = 0; i < perInterfaceTotal.length; i++) {
-            perInterfaceTotal[i] = new Entry();
-        }
+        tunAdjustmentInit(tunUid, tunIface, underlyingIface, tunIfaceTotal, underlyingIfaceTotal);
 
-        tunAdjustmentInit(tunUid, tunIface, underlyingIfaces, tunIfaceTotal, perInterfaceTotal,
-                underlyingIfacesTotal);
-
-        // If tunIface < underlyingIfacesTotal, it leaves the overhead traffic in the VPN app.
-        // If tunIface > underlyingIfacesTotal, the VPN app doesn't get credit for data compression.
+        // If tunIface < underlyingIface, it leaves the overhead traffic in the VPN app.
+        // If tunIface > underlyingIface, the VPN app doesn't get credit for data compression.
         // Negative stats should be avoided.
-        final Entry[] moved =
-                addTrafficToApplications(tunUid, tunIface, underlyingIfaces, tunIfaceTotal,
-                        perInterfaceTotal, underlyingIfacesTotal);
-        deductTrafficFromVpnApp(tunUid, underlyingIfaces, moved);
+        Entry pool = tunGetPool(tunIfaceTotal, underlyingIfaceTotal);
+        if (pool.isEmpty()) {
+            return true;
+        }
+        Entry moved =
+                addTrafficToApplications(tunUid, tunIface, underlyingIface, tunIfaceTotal, pool);
+        deductTrafficFromVpnApp(tunUid, underlyingIface, moved);
+
+        if (!moved.isEmpty()) {
+            Slog.wtf(TAG, "Failed to deduct underlying network traffic from VPN package. Moved="
+                    + moved);
+            return false;
+        }
+        return true;
     }
 
     /**
      * Initializes the data used by the migrateTun() method.
      *
-     * <p>This is the first pass iteration which does the following work:
-     *
-     * <ul>
-     *   <li>Adds up all the traffic through the tunUid's underlyingIfaces (both foreground and
-     *       background).
-     *   <li>Adds up all the traffic through tun0 excluding traffic from the vpn app itself.
-     * </ul>
-     *
-     * @param tunUid uid of the VPN application
-     * @param tunIface iface of the vpn tunnel
-     * @param underlyingIfaces underlying network ifaces used by the VPN application
-     * @param tunIfaceTotal output parameter; combined data usage by all apps using VPN
-     * @param perInterfaceTotal output parameter; data usage by VPN app, grouped by its {@code
-     *     underlyingIfaces}
-     * @param underlyingIfacesTotal output parameter; data usage by VPN, summed across all of its
-     *     {@code underlyingIfaces}
+     * This is the first pass iteration which does the following work:
+     * (1) Adds up all the traffic through the tunUid's underlyingIface
+     *     (both foreground and background).
+     * (2) Adds up all the traffic through tun0 excluding traffic from the vpn app itself.
      */
-    private void tunAdjustmentInit(int tunUid, @NonNull String tunIface,
-            @NonNull String[] underlyingIfaces, @NonNull Entry tunIfaceTotal,
-            @NonNull Entry[] perInterfaceTotal, @NonNull Entry underlyingIfacesTotal) {
-        final Entry recycle = new Entry();
+    private void tunAdjustmentInit(int tunUid, String tunIface, String underlyingIface,
+            Entry tunIfaceTotal, Entry underlyingIfaceTotal) {
+        Entry recycle = new Entry();
         for (int i = 0; i < size; i++) {
             getValues(i, recycle);
             if (recycle.uid == UID_ALL) {
                 throw new IllegalStateException(
                         "Cannot adjust VPN accounting on an iface aggregated NetworkStats.");
-            }
-            if (recycle.set == SET_DBG_VPN_IN || recycle.set == SET_DBG_VPN_OUT) {
+            } if (recycle.set == SET_DBG_VPN_IN || recycle.set == SET_DBG_VPN_OUT) {
                 throw new IllegalStateException(
                         "Cannot adjust VPN accounting on a NetworkStats containing SET_DBG_VPN_*");
             }
-            if (recycle.tag != TAG_NONE) {
-                // TODO(b/123666283): Take all tags for tunUid into account.
-                continue;
+
+            if (recycle.uid == tunUid && recycle.tag == TAG_NONE
+                    && Objects.equals(underlyingIface, recycle.iface)) {
+                underlyingIfaceTotal.add(recycle);
             }
 
-            if (recycle.uid == tunUid) {
-                // Add up traffic through tunUid's underlying interfaces.
-                for (int j = 0; j < underlyingIfaces.length; j++) {
-                    if (Objects.equals(underlyingIfaces[j], recycle.iface)) {
-                        perInterfaceTotal[j].add(recycle);
-                        underlyingIfacesTotal.add(recycle);
-                        break;
-                    }
-                }
-            } else if (tunIface.equals(recycle.iface)) {
+            if (recycle.uid != tunUid && recycle.tag == TAG_NONE
+                    && Objects.equals(tunIface, recycle.iface)) {
                 // Add up all tunIface traffic excluding traffic from the vpn app itself.
                 tunIfaceTotal.add(recycle);
             }
         }
     }
 
-    /**
-     * Distributes traffic across apps that are using given {@code tunIface}, and returns the total
-     * traffic that should be moved off of {@code tunUid} grouped by {@code underlyingIfaces}.
-     *
-     * @param tunUid uid of the VPN application
-     * @param tunIface iface of the vpn tunnel
-     * @param underlyingIfaces underlying network ifaces used by the VPN application
-     * @param tunIfaceTotal combined data usage across all apps using {@code tunIface}
-     * @param perInterfaceTotal data usage by VPN app, grouped by its {@code underlyingIfaces}
-     * @param underlyingIfacesTotal data usage by VPN, summed across all of its {@code
-     *     underlyingIfaces}
-     */
-    private Entry[] addTrafficToApplications(int tunUid, @NonNull String tunIface,
-            @NonNull String[] underlyingIfaces, @NonNull Entry tunIfaceTotal,
-            @NonNull Entry[] perInterfaceTotal, @NonNull Entry underlyingIfacesTotal) {
-        // Traffic that should be moved off of each underlying interface for tunUid (see
-        // deductTrafficFromVpnApp below).
-        final Entry[] moved = new Entry[underlyingIfaces.length];
-        for (int i = 0; i < underlyingIfaces.length; i++) {
-            moved[i] = new Entry();
-        }
+    private static Entry tunGetPool(Entry tunIfaceTotal, Entry underlyingIfaceTotal) {
+        Entry pool = new Entry();
+        pool.rxBytes = Math.min(tunIfaceTotal.rxBytes, underlyingIfaceTotal.rxBytes);
+        pool.rxPackets = Math.min(tunIfaceTotal.rxPackets, underlyingIfaceTotal.rxPackets);
+        pool.txBytes = Math.min(tunIfaceTotal.txBytes, underlyingIfaceTotal.txBytes);
+        pool.txPackets = Math.min(tunIfaceTotal.txPackets, underlyingIfaceTotal.txPackets);
+        pool.operations = Math.min(tunIfaceTotal.operations, underlyingIfaceTotal.operations);
+        return pool;
+    }
 
-        final Entry tmpEntry = new Entry();
+    private Entry addTrafficToApplications(int tunUid, String tunIface, String underlyingIface,
+            Entry tunIfaceTotal, Entry pool) {
+        Entry moved = new Entry();
+        Entry tmpEntry = new Entry();
+        tmpEntry.iface = underlyingIface;
         for (int i = 0; i < size; i++) {
-            if (!Objects.equals(iface[i], tunIface)) {
-                // Consider only entries that go onto the VPN interface.
-                continue;
-            }
-            if (uid[i] == tunUid) {
-                // Exclude VPN app from the redistribution, as it can choose to create packet
-                // streams by writing to itself.
-                continue;
-            }
-            tmpEntry.uid = uid[i];
-            tmpEntry.tag = tag[i];
-            tmpEntry.metered = metered[i];
-            tmpEntry.roaming = roaming[i];
-            tmpEntry.defaultNetwork = defaultNetwork[i];
-
-            // In a first pass, compute each UID's total share of data across all underlyingIfaces.
-            // This is computed on the basis of the share of each UID's usage over tunIface.
-            // TODO: Consider refactoring first pass into a separate helper method.
-            long totalRxBytes = 0;
-            if (tunIfaceTotal.rxBytes > 0) {
-                // Note - The multiplication below should not overflow since NetworkStatsService
-                // processes this every time device has transmitted/received amount equivalent to
-                // global threshold alert (~ 2MB) across all interfaces.
-                final long rxBytesAcrossUnderlyingIfaces =
-                        underlyingIfacesTotal.rxBytes * rxBytes[i] / tunIfaceTotal.rxBytes;
-                // app must not be blamed for more than it consumed on tunIface
-                totalRxBytes = Math.min(rxBytes[i], rxBytesAcrossUnderlyingIfaces);
-            }
-            long totalRxPackets = 0;
-            if (tunIfaceTotal.rxPackets > 0) {
-                final long rxPacketsAcrossUnderlyingIfaces =
-                        underlyingIfacesTotal.rxPackets * rxPackets[i] / tunIfaceTotal.rxPackets;
-                totalRxPackets = Math.min(rxPackets[i], rxPacketsAcrossUnderlyingIfaces);
-            }
-            long totalTxBytes = 0;
-            if (tunIfaceTotal.txBytes > 0) {
-                final long txBytesAcrossUnderlyingIfaces =
-                        underlyingIfacesTotal.txBytes * txBytes[i] / tunIfaceTotal.txBytes;
-                totalTxBytes = Math.min(txBytes[i], txBytesAcrossUnderlyingIfaces);
-            }
-            long totalTxPackets = 0;
-            if (tunIfaceTotal.txPackets > 0) {
-                final long txPacketsAcrossUnderlyingIfaces =
-                        underlyingIfacesTotal.txPackets * txPackets[i] / tunIfaceTotal.txPackets;
-                totalTxPackets = Math.min(txPackets[i], txPacketsAcrossUnderlyingIfaces);
-            }
-            long totalOperations = 0;
-            if (tunIfaceTotal.operations > 0) {
-                final long operationsAcrossUnderlyingIfaces =
-                        underlyingIfacesTotal.operations * operations[i] / tunIfaceTotal.operations;
-                totalOperations = Math.min(operations[i], operationsAcrossUnderlyingIfaces);
-            }
-            // In a second pass, distribute these values across interfaces in the proportion that
-            // each interface represents of the total traffic of the underlying interfaces.
-            for (int j = 0; j < underlyingIfaces.length; j++) {
-                tmpEntry.iface = underlyingIfaces[j];
-                tmpEntry.rxBytes = 0;
-                // Reset 'set' to correct value since it gets updated when adding debug info below.
-                tmpEntry.set = set[i];
-                if (underlyingIfacesTotal.rxBytes > 0) {
-                    tmpEntry.rxBytes =
-                            totalRxBytes
-                                    * perInterfaceTotal[j].rxBytes
-                                    / underlyingIfacesTotal.rxBytes;
+            // the vpn app is excluded from the redistribution but all moved traffic will be
+            // deducted from the vpn app (see deductTrafficFromVpnApp below).
+            if (Objects.equals(iface[i], tunIface) && uid[i] != tunUid) {
+                if (tunIfaceTotal.rxBytes > 0) {
+                    tmpEntry.rxBytes = pool.rxBytes * rxBytes[i] / tunIfaceTotal.rxBytes;
+                } else {
+                    tmpEntry.rxBytes = 0;
                 }
-                tmpEntry.rxPackets = 0;
-                if (underlyingIfacesTotal.rxPackets > 0) {
-                    tmpEntry.rxPackets =
-                            totalRxPackets
-                                    * perInterfaceTotal[j].rxPackets
-                                    / underlyingIfacesTotal.rxPackets;
+                if (tunIfaceTotal.rxPackets > 0) {
+                    tmpEntry.rxPackets = pool.rxPackets * rxPackets[i] / tunIfaceTotal.rxPackets;
+                } else {
+                    tmpEntry.rxPackets = 0;
                 }
-                tmpEntry.txBytes = 0;
-                if (underlyingIfacesTotal.txBytes > 0) {
-                    tmpEntry.txBytes =
-                            totalTxBytes
-                                    * perInterfaceTotal[j].txBytes
-                                    / underlyingIfacesTotal.txBytes;
+                if (tunIfaceTotal.txBytes > 0) {
+                    tmpEntry.txBytes = pool.txBytes * txBytes[i] / tunIfaceTotal.txBytes;
+                } else {
+                    tmpEntry.txBytes = 0;
                 }
-                tmpEntry.txPackets = 0;
-                if (underlyingIfacesTotal.txPackets > 0) {
-                    tmpEntry.txPackets =
-                            totalTxPackets
-                                    * perInterfaceTotal[j].txPackets
-                                    / underlyingIfacesTotal.txPackets;
+                if (tunIfaceTotal.txPackets > 0) {
+                    tmpEntry.txPackets = pool.txPackets * txPackets[i] / tunIfaceTotal.txPackets;
+                } else {
+                    tmpEntry.txPackets = 0;
                 }
-                tmpEntry.operations = 0;
-                if (underlyingIfacesTotal.operations > 0) {
+                if (tunIfaceTotal.operations > 0) {
                     tmpEntry.operations =
-                            totalOperations
-                                    * perInterfaceTotal[j].operations
-                                    / underlyingIfacesTotal.operations;
+                            pool.operations * operations[i] / tunIfaceTotal.operations;
+                } else {
+                    tmpEntry.operations = 0;
                 }
-
+                tmpEntry.uid = uid[i];
+                tmpEntry.tag = tag[i];
+                tmpEntry.set = set[i];
+                tmpEntry.metered = metered[i];
+                tmpEntry.roaming = roaming[i];
+                tmpEntry.defaultNetwork = defaultNetwork[i];
                 combineValues(tmpEntry);
                 if (tag[i] == TAG_NONE) {
-                    moved[j].add(tmpEntry);
+                    moved.add(tmpEntry);
                     // Add debug info
                     tmpEntry.set = SET_DBG_VPN_IN;
                     combineValues(tmpEntry);
@@ -1407,45 +1311,38 @@
         return moved;
     }
 
-    private void deductTrafficFromVpnApp(
-            int tunUid,
-            @NonNull String[] underlyingIfaces,
-            @NonNull Entry[] moved) {
-        for (int i = 0; i < underlyingIfaces.length; i++) {
-            // Add debug info
-            moved[i].uid = tunUid;
-            moved[i].set = SET_DBG_VPN_OUT;
-            moved[i].tag = TAG_NONE;
-            moved[i].iface = underlyingIfaces[i];
-            moved[i].metered = METERED_ALL;
-            moved[i].roaming = ROAMING_ALL;
-            moved[i].defaultNetwork = DEFAULT_NETWORK_ALL;
-            combineValues(moved[i]);
+    private void deductTrafficFromVpnApp(int tunUid, String underlyingIface, Entry moved) {
+        // Add debug info
+        moved.uid = tunUid;
+        moved.set = SET_DBG_VPN_OUT;
+        moved.tag = TAG_NONE;
+        moved.iface = underlyingIface;
+        moved.metered = METERED_ALL;
+        moved.roaming = ROAMING_ALL;
+        moved.defaultNetwork = DEFAULT_NETWORK_ALL;
+        combineValues(moved);
 
-            // Caveat: if the vpn software uses tag, the total tagged traffic may be greater than
-            // the TAG_NONE traffic.
-            //
-            // Relies on the fact that the underlying traffic only has state ROAMING_NO and
-            // METERED_NO, which should be the case as it comes directly from the /proc file.
-            // We only blend in the roaming data after applying these adjustments, by checking the
-            // NetworkIdentity of the underlying iface.
-            final int idxVpnBackground = findIndex(underlyingIfaces[i], tunUid, SET_DEFAULT,
-                            TAG_NONE, METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
-            if (idxVpnBackground != -1) {
-                // Note - tunSubtract also updates moved[i]; whatever traffic that's left is removed
-                // from foreground usage.
-                tunSubtract(idxVpnBackground, this, moved[i]);
-            }
+        // Caveat: if the vpn software uses tag, the total tagged traffic may be greater than
+        // the TAG_NONE traffic.
+        //
+        // Relies on the fact that the underlying traffic only has state ROAMING_NO and METERED_NO,
+        // which should be the case as it comes directly from the /proc file. We only blend in the
+        // roaming data after applying these adjustments, by checking the NetworkIdentity of the
+        // underlying iface.
+        int idxVpnBackground = findIndex(underlyingIface, tunUid, SET_DEFAULT, TAG_NONE,
+                METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
+        if (idxVpnBackground != -1) {
+            tunSubtract(idxVpnBackground, this, moved);
+        }
 
-            final int idxVpnForeground = findIndex(underlyingIfaces[i], tunUid, SET_FOREGROUND,
-                            TAG_NONE, METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
-            if (idxVpnForeground != -1) {
-                tunSubtract(idxVpnForeground, this, moved[i]);
-            }
+        int idxVpnForeground = findIndex(underlyingIface, tunUid, SET_FOREGROUND, TAG_NONE,
+                METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
+        if (idxVpnForeground != -1) {
+            tunSubtract(idxVpnForeground, this, moved);
         }
     }
 
-    private static void tunSubtract(int i, @NonNull NetworkStats left, @NonNull Entry right) {
+    private static void tunSubtract(int i, NetworkStats left, Entry right) {
         long rxBytes = Math.min(left.rxBytes[i], right.rxBytes);
         left.rxBytes[i] -= rxBytes;
         right.rxBytes -= rxBytes;
diff --git a/core/java/android/net/NetworkStatsHistory.java b/core/java/android/net/NetworkStatsHistory.java
index d53e032..f61260e 100644
--- a/core/java/android/net/NetworkStatsHistory.java
+++ b/core/java/android/net/NetworkStatsHistory.java
@@ -719,7 +719,7 @@
     }
 
     @UnsupportedAppUsage
-    public static final Creator<NetworkStatsHistory> CREATOR = new Creator<NetworkStatsHistory>() {
+    public static final @android.annotation.NonNull Creator<NetworkStatsHistory> CREATOR = new Creator<NetworkStatsHistory>() {
         @Override
         public NetworkStatsHistory createFromParcel(Parcel in) {
             return new NetworkStatsHistory(in);
diff --git a/core/java/android/net/NetworkTemplate.java b/core/java/android/net/NetworkTemplate.java
index 60ae352..ae421a4 100644
--- a/core/java/android/net/NetworkTemplate.java
+++ b/core/java/android/net/NetworkTemplate.java
@@ -495,7 +495,7 @@
     }
 
     @UnsupportedAppUsage
-    public static final Creator<NetworkTemplate> CREATOR = new Creator<NetworkTemplate>() {
+    public static final @android.annotation.NonNull Creator<NetworkTemplate> CREATOR = new Creator<NetworkTemplate>() {
         @Override
         public NetworkTemplate createFromParcel(Parcel in) {
             return new NetworkTemplate(in);
diff --git a/core/java/android/net/nsd/NsdServiceInfo.java b/core/java/android/net/nsd/NsdServiceInfo.java
index 9ba17ed..459b140 100644
--- a/core/java/android/net/nsd/NsdServiceInfo.java
+++ b/core/java/android/net/nsd/NsdServiceInfo.java
@@ -355,7 +355,7 @@
     }
 
     /** Implement the Parcelable interface */
-    public static final Creator<NsdServiceInfo> CREATOR =
+    public static final @android.annotation.NonNull Creator<NsdServiceInfo> CREATOR =
         new Creator<NsdServiceInfo>() {
             public NsdServiceInfo createFromParcel(Parcel in) {
                 NsdServiceInfo info = new NsdServiceInfo();
diff --git a/services/core/java/com/android/server/IpSecService.java b/services/core/java/com/android/server/IpSecService.java
index c1f5255..b413d8f 100644
--- a/services/core/java/com/android/server/IpSecService.java
+++ b/services/core/java/com/android/server/IpSecService.java
@@ -1369,7 +1369,7 @@
     public synchronized IpSecTunnelInterfaceResponse createTunnelInterface(
             String localAddr, String remoteAddr, Network underlyingNetwork, IBinder binder,
             String callingPackage) {
-        enforceTunnelPermissions(callingPackage);
+        enforceTunnelFeatureAndPermissions(callingPackage);
         checkNotNull(binder, "Null Binder passed to createTunnelInterface");
         checkNotNull(underlyingNetwork, "No underlying network was specified");
         checkInetAddress(localAddr);
@@ -1455,7 +1455,7 @@
     @Override
     public synchronized void addAddressToTunnelInterface(
             int tunnelResourceId, LinkAddress localAddr, String callingPackage) {
-        enforceTunnelPermissions(callingPackage);
+        enforceTunnelFeatureAndPermissions(callingPackage);
         UserRecord userRecord = mUserResourceTracker.getUserRecord(Binder.getCallingUid());
 
         // Get tunnelInterface record; if no such interface is found, will throw
@@ -1484,7 +1484,7 @@
     @Override
     public synchronized void removeAddressFromTunnelInterface(
             int tunnelResourceId, LinkAddress localAddr, String callingPackage) {
-        enforceTunnelPermissions(callingPackage);
+        enforceTunnelFeatureAndPermissions(callingPackage);
 
         UserRecord userRecord = mUserResourceTracker.getUserRecord(Binder.getCallingUid());
         // Get tunnelInterface record; if no such interface is found, will throw
@@ -1513,7 +1513,7 @@
     @Override
     public synchronized void deleteTunnelInterface(
             int resourceId, String callingPackage) throws RemoteException {
-        enforceTunnelPermissions(callingPackage);
+        enforceTunnelFeatureAndPermissions(callingPackage);
         UserRecord userRecord = mUserResourceTracker.getUserRecord(Binder.getCallingUid());
         releaseResource(userRecord.mTunnelInterfaceRecords, resourceId);
     }
@@ -1642,7 +1642,12 @@
 
     private static final String TUNNEL_OP = AppOpsManager.OPSTR_MANAGE_IPSEC_TUNNELS;
 
-    private void enforceTunnelPermissions(String callingPackage) {
+    private void enforceTunnelFeatureAndPermissions(String callingPackage) {
+        if (!mContext.getPackageManager().hasSystemFeature(PackageManager.FEATURE_IPSEC_TUNNELS)) {
+            throw new UnsupportedOperationException(
+                    "IPsec Tunnel Mode requires PackageManager.FEATURE_IPSEC_TUNNELS");
+        }
+
         checkNotNull(callingPackage, "Null calling package cannot create IpSec tunnels");
         switch (getAppOpsManager().noteOp(TUNNEL_OP, Binder.getCallingUid(), callingPackage)) {
             case AppOpsManager.MODE_DEFAULT:
@@ -1714,7 +1719,7 @@
             IpSecConfig c, IBinder binder, String callingPackage) throws RemoteException {
         checkNotNull(c);
         if (c.getMode() == IpSecTransform.MODE_TUNNEL) {
-            enforceTunnelPermissions(callingPackage);
+            enforceTunnelFeatureAndPermissions(callingPackage);
         }
         checkIpSecConfig(c);
         checkNotNull(binder, "Null Binder passed to createTransform");
@@ -1822,7 +1827,7 @@
     public synchronized void applyTunnelModeTransform(
             int tunnelResourceId, int direction,
             int transformResourceId, String callingPackage) throws RemoteException {
-        enforceTunnelPermissions(callingPackage);
+        enforceTunnelFeatureAndPermissions(callingPackage);
         checkDirection(direction);
 
         int callingUid = Binder.getCallingUid();
diff --git a/services/core/java/com/android/server/net/NetworkStatsFactory.java b/services/core/java/com/android/server/net/NetworkStatsFactory.java
index 2e64965..69efd02 100644
--- a/services/core/java/com/android/server/net/NetworkStatsFactory.java
+++ b/services/core/java/com/android/server/net/NetworkStatsFactory.java
@@ -263,11 +263,6 @@
         return stats;
     }
 
-    /**
-     * @deprecated Use NetworkStatsService#getDetailedUidStats which also accounts for
-     * VPN traffic
-     */
-    @Deprecated
     public NetworkStats readNetworkStatsDetail() throws IOException {
         return readNetworkStatsDetail(UID_ALL, null, TAG_ALL, null);
     }
diff --git a/services/core/java/com/android/server/net/NetworkStatsRecorder.java b/services/core/java/com/android/server/net/NetworkStatsRecorder.java
index bdff500..a2e7e0c 100644
--- a/services/core/java/com/android/server/net/NetworkStatsRecorder.java
+++ b/services/core/java/com/android/server/net/NetworkStatsRecorder.java
@@ -41,10 +41,10 @@
 import com.android.internal.util.FileRotator;
 import com.android.internal.util.IndentingPrintWriter;
 
-import com.google.android.collect.Sets;
-
 import libcore.io.IoUtils;
 
+import com.google.android.collect.Sets;
+
 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
 import java.io.File;
@@ -234,7 +234,7 @@
 
         if (vpnArray != null) {
             for (VpnInfo info : vpnArray) {
-                delta.migrateTun(info.ownerUid, info.vpnIface, info.underlyingIfaces);
+                delta.migrateTun(info.ownerUid, info.vpnIface, info.primaryUnderlyingIface);
             }
         }
 
diff --git a/services/core/java/com/android/server/net/NetworkStatsService.java b/services/core/java/com/android/server/net/NetworkStatsService.java
index 484efd6..f34ace5 100644
--- a/services/core/java/com/android/server/net/NetworkStatsService.java
+++ b/services/core/java/com/android/server/net/NetworkStatsService.java
@@ -105,6 +105,7 @@
 import android.os.HandlerThread;
 import android.os.IBinder;
 import android.os.INetworkManagementService;
+import android.os.Looper;
 import android.os.Message;
 import android.os.Messenger;
 import android.os.PowerManager;
@@ -292,22 +293,6 @@
     /** Data layer operation counters for splicing into other structures. */
     private NetworkStats mUidOperations = new NetworkStats(0L, 10);
 
-    /**
-     * Snapshot containing most recent network stats for all UIDs across all interfaces and tags
-     * since boot.
-     *
-     * <p>Maintains migrated VPN stats which are result of performing TUN migration on {@link
-     * #mLastUidDetailSnapshot}.
-     */
-    @GuardedBy("mStatsLock")
-    private NetworkStats mTunAdjustedStats;
-    /**
-     * Used by {@link #mTunAdjustedStats} to migrate VPN traffic over delta between this snapshot
-     * and latest snapshot.
-     */
-    @GuardedBy("mStatsLock")
-    private NetworkStats mLastUidDetailSnapshot;
-
     /** Must be set in factory by calling #setHandler. */
     private Handler mHandler;
     private Handler.Callback mHandlerCallback;
@@ -341,6 +326,12 @@
                 Clock.systemUTC());
     }
 
+    private static final class NetworkStatsHandler extends Handler {
+        NetworkStatsHandler(Looper looper, Handler.Callback callback) {
+            super(looper, callback);
+        }
+    }
+
     public static NetworkStatsService create(Context context,
                 INetworkManagementService networkManager) {
         AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
@@ -357,7 +348,7 @@
         HandlerThread handlerThread = new HandlerThread(TAG);
         Handler.Callback callback = new HandlerCallback(service);
         handlerThread.start();
-        Handler handler = new Handler(handlerThread.getLooper(), callback);
+        Handler handler = new NetworkStatsHandler(handlerThread.getLooper(), callback);
         service.setHandler(handler, callback);
         return service;
     }
@@ -821,39 +812,15 @@
     @Override
     public NetworkStats getDetailedUidStats(String[] requiredIfaces) {
         try {
-            // Get the latest snapshot from NetworkStatsFactory.
-            // TODO: Querying for INTERFACES_ALL may incur performance penalty. Consider restricting
-            // this to limited set of ifaces.
-            NetworkStats uidDetailStats = getNetworkStatsUidDetail(INTERFACES_ALL);
-
-            // Migrate traffic from VPN UID over delta and update mTunAdjustedStats.
-            NetworkStats result;
-            synchronized (mStatsLock) {
-                migrateTunTraffic(uidDetailStats, mVpnInfos);
-                result = mTunAdjustedStats.clone();
-            }
-
-            // Apply filter based on ifacesToQuery.
             final String[] ifacesToQuery =
                     NetworkStatsFactory.augmentWithStackedInterfaces(requiredIfaces);
-            result.filter(UID_ALL, ifacesToQuery, TAG_ALL);
-            return result;
+            return getNetworkStatsUidDetail(ifacesToQuery);
         } catch (RemoteException e) {
             Log.wtf(TAG, "Error compiling UID stats", e);
             return new NetworkStats(0L, 0);
         }
     }
 
-    @VisibleForTesting
-    NetworkStats getTunAdjustedStats() {
-        synchronized (mStatsLock) {
-            if (mTunAdjustedStats == null) {
-                return null;
-            }
-            return mTunAdjustedStats.clone();
-        }
-    }
-
     @Override
     public String[] getMobileIfaces() {
         return mMobileIfaces;
@@ -1328,34 +1295,6 @@
         // a race condition between the service handler thread and the observer's
         mStatsObservers.updateStats(xtSnapshot, uidSnapshot, new ArrayMap<>(mActiveIfaces),
                 new ArrayMap<>(mActiveUidIfaces), vpnArray, currentTime);
-
-        migrateTunTraffic(uidSnapshot, vpnArray);
-    }
-
-    /**
-     * Updates {@link #mTunAdjustedStats} with the delta containing traffic migrated off of VPNs.
-     */
-    @GuardedBy("mStatsLock")
-    private void migrateTunTraffic(NetworkStats uidDetailStats, VpnInfo[] vpnInfoArray) {
-        if (mTunAdjustedStats == null) {
-            // Either device booted or system server restarted, hence traffic cannot be migrated
-            // correctly without knowing the past state of VPN's underlying networks.
-            mTunAdjustedStats = uidDetailStats;
-            mLastUidDetailSnapshot = uidDetailStats;
-            return;
-        }
-        // Migrate delta traffic from VPN to other apps.
-        NetworkStats delta = uidDetailStats.subtract(mLastUidDetailSnapshot);
-        for (VpnInfo info : vpnInfoArray) {
-            delta.migrateTun(info.ownerUid, info.vpnIface, info.underlyingIfaces);
-        }
-        // Filter out debug entries as that may lead to over counting.
-        delta.filterDebugEntries();
-        // Update #mTunAdjustedStats with migrated delta.
-        mTunAdjustedStats.combineAllValues(delta);
-        mTunAdjustedStats.setElapsedRealtime(uidDetailStats.getElapsedRealtime());
-        // Update last snapshot.
-        mLastUidDetailSnapshot = uidDetailStats;
     }
 
     /**