Merge changes Ieb8645ac,I6466ec14,I87deb82b,I995b108e,Ib6521459 am: f4c10e8bc2

am: 48f59a0fdf

Change-Id: I960e94b03b29282ae2b03f78a19ed2692bd88e05

core/java/android/net/INetworkStatsService.aidl

@@ -66,7 +66,6 @@ interface INetworkStatsService {
     /** Force update of ifaces. */
     void forceUpdateIfaces(
          in Network[] defaultNetworks,
-         in VpnInfo[] vpnArray,
          in NetworkState[] networkStates,
          in String activeIface);
     /** Force update of statistics. */

core/java/android/net/NetworkStats.java

@@ -18,11 +18,11 @@ package android.net;
 
 import static android.os.Process.CLAT_UID;
 
+import android.annotation.NonNull;
 import android.annotation.UnsupportedAppUsage;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.SystemClock;
-import android.util.Slog;
 import android.util.SparseBooleanArray;
 
 import com.android.internal.annotations.VisibleForTesting;
@@ -36,6 +36,7 @@ import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Objects;
+import java.util.function.Predicate;
 
 /**
  * Collection of active network statistics. Can contain summary details across
@@ -993,23 +994,33 @@ public class NetworkStats implements Parcelable {
         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);
-            final boolean matches =
+            if (predicate.test(entry)) {
-                    (limitUid == UID_ALL || limitUid == entry.uid)
+                if (nextOutputEntry != i) {
-                    && (limitTag == TAG_ALL || limitTag == entry.tag)
+                    setValues(nextOutputEntry, entry);
-                    && (limitIfaces == INTERFACES_ALL
+                }
-                            || ArrayUtils.contains(limitIfaces, entry.iface));
-
-            if (matches) {
-                setValues(nextOutputEntry, entry);
                 nextOutputEntry++;
             }
         }
-
         size = nextOutputEntry;
     }
 
@@ -1175,133 +1186,221 @@ public class NetworkStats implements Parcelable {
     /**
      * VPN accounting. Move some VPN's underlying traffic to other UIDs that use tun0 iface.
      *
-     * This method should only be called on delta NetworkStats. Do not call this method on a
+     * <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
+     * snapshot {@link NetworkStats} object because the tunUid and/or the underlyingIface may change
-     * change over time.
+     * over time.
      *
-     * This method performs adjustments for one active VPN package and one VPN iface at a time.
+     * <p>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 underlyingIface the primary underlying network iface used by the VPN application
+     * @param underlyingIfaces underlying network ifaces used by the VPN application
-     * @return true if it successfully adjusts the accounting for VPN, false otherwise
      */
-    public boolean migrateTun(int tunUid, String tunIface, String underlyingIface) {
+    public void migrateTun(int tunUid, @NonNull String tunIface,
-        Entry tunIfaceTotal = new Entry();
+            @NonNull String[] underlyingIfaces) {
-        Entry underlyingIfaceTotal = new Entry();
+        // 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();
 
-        tunAdjustmentInit(tunUid, tunIface, underlyingIface, tunIfaceTotal, underlyingIfaceTotal);
+        for (int i = 0; i < perInterfaceTotal.length; i++) {
+            perInterfaceTotal[i] = new Entry();
+        }
 
-        // If tunIface < underlyingIface, it leaves the overhead traffic in the VPN app.
+        tunAdjustmentInit(tunUid, tunIface, underlyingIfaces, tunIfaceTotal, perInterfaceTotal,
-        // If tunIface > underlyingIface, the VPN app doesn't get credit for data compression.
+                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.
         // Negative stats should be avoided.
-        Entry pool = tunGetPool(tunIfaceTotal, underlyingIfaceTotal);
+        final Entry[] moved =
-        if (pool.isEmpty()) {
+                addTrafficToApplications(tunUid, tunIface, underlyingIfaces, tunIfaceTotal,
-            return true;
+                        perInterfaceTotal, underlyingIfacesTotal);
-        }
+        deductTrafficFromVpnApp(tunUid, underlyingIfaces, moved);
-        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.
      *
-     * This is the first pass iteration which does the following work:
+     * <p>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).
+     * <ul>
-     * (2) Adds up all the traffic through tun0 excluding traffic from the vpn app itself.
+     *   <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}
      */
-    private void tunAdjustmentInit(int tunUid, String tunIface, String underlyingIface,
+    private void tunAdjustmentInit(int tunUid, @NonNull String tunIface,
-            Entry tunIfaceTotal, Entry underlyingIfaceTotal) {
+            @NonNull String[] underlyingIfaces, @NonNull Entry tunIfaceTotal,
-        Entry recycle = new Entry();
+            @NonNull Entry[] perInterfaceTotal, @NonNull Entry underlyingIfacesTotal) {
+        final 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) {
-            if (recycle.uid == tunUid && recycle.tag == TAG_NONE
+                // TODO(b/123666283): Take all tags for tunUid into account.
-                    && Objects.equals(underlyingIface, recycle.iface)) {
+                continue;
-                underlyingIfaceTotal.add(recycle);
             }
 
-            if (recycle.uid != tunUid && recycle.tag == TAG_NONE
+            if (recycle.uid == tunUid) {
-                    && Objects.equals(tunIface, recycle.iface)) {
+                // 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)) {
                 // Add up all tunIface traffic excluding traffic from the vpn app itself.
                 tunIfaceTotal.add(recycle);
             }
         }
     }
 
-    private static Entry tunGetPool(Entry tunIfaceTotal, Entry underlyingIfaceTotal) {
+    /**
-        Entry pool = new Entry();
+     * Distributes traffic across apps that are using given {@code tunIface}, and returns the total
-        pool.rxBytes = Math.min(tunIfaceTotal.rxBytes, underlyingIfaceTotal.rxBytes);
+     * traffic that should be moved off of {@code tunUid} grouped by {@code underlyingIfaces}.
-        pool.rxPackets = Math.min(tunIfaceTotal.rxPackets, underlyingIfaceTotal.rxPackets);
+     *
-        pool.txBytes = Math.min(tunIfaceTotal.txBytes, underlyingIfaceTotal.txBytes);
+     * @param tunUid uid of the VPN application
-        pool.txPackets = Math.min(tunIfaceTotal.txPackets, underlyingIfaceTotal.txPackets);
+     * @param tunIface iface of the vpn tunnel
-        pool.operations = Math.min(tunIfaceTotal.operations, underlyingIfaceTotal.operations);
+     * @param underlyingIfaces underlying network ifaces used by the VPN application
-        return pool;
+     * @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 Entry addTrafficToApplications(int tunUid, String tunIface, String underlyingIface,
+        final Entry tmpEntry = new Entry();
-            Entry tunIfaceTotal, Entry pool) {
+        final int origSize = size;
-        Entry moved = new Entry();
+        for (int i = 0; i < origSize; i++) {
-        Entry tmpEntry = new Entry();
+            if (!Objects.equals(iface[i], tunIface)) {
-        tmpEntry.iface = underlyingIface;
+                // Consider only entries that go onto the VPN interface.
-        for (int i = 0; i < size; i++) {
+                continue;
-            // the vpn app is excluded from the redistribution but all moved traffic will be
+            }
-            // deducted from the vpn app (see deductTrafficFromVpnApp below).
+            if (uid[i] == tunUid) {
-            if (Objects.equals(iface[i], tunIface) && uid[i] != tunUid) {
+                // Exclude VPN app from the redistribution, as it can choose to create packet
-                if (tunIfaceTotal.rxBytes > 0) {
+                // streams by writing to itself.
-                    tmpEntry.rxBytes = pool.rxBytes * rxBytes[i] / tunIfaceTotal.rxBytes;
+                continue;
-                } else {
+            }
-                    tmpEntry.rxBytes = 0;
+            tmpEntry.uid = uid[i];
-                }
+            tmpEntry.tag = tag[i];
-                if (tunIfaceTotal.rxPackets > 0) {
+            tmpEntry.metered = metered[i];
-                    tmpEntry.rxPackets = pool.rxPackets * rxPackets[i] / tunIfaceTotal.rxPackets;
+            tmpEntry.roaming = roaming[i];
-                } else {
+            tmpEntry.defaultNetwork = defaultNetwork[i];
-                    tmpEntry.rxPackets = 0;
+
-                }
+            // In a first pass, compute this entry's total share of data across all
-                if (tunIfaceTotal.txBytes > 0) {
+            // underlyingIfaces. This is computed on the basis of the share of this entry's usage
-                    tmpEntry.txBytes = pool.txBytes * txBytes[i] / tunIfaceTotal.txBytes;
+            // over tunIface.
-                } else {
+            // TODO: Consider refactoring first pass into a separate helper method.
-                    tmpEntry.txBytes = 0;
+            long totalRxBytes = 0;
-                }
+            if (tunIfaceTotal.rxBytes > 0) {
-                if (tunIfaceTotal.txPackets > 0) {
+                // Note - The multiplication below should not overflow since NetworkStatsService
-                    tmpEntry.txPackets = pool.txPackets * txPackets[i] / tunIfaceTotal.txPackets;
+                // processes this every time device has transmitted/received amount equivalent to
-                } else {
+                // global threshold alert (~ 2MB) across all interfaces.
-                    tmpEntry.txPackets = 0;
+                final long rxBytesAcrossUnderlyingIfaces =
-                }
+                        underlyingIfacesTotal.rxBytes * rxBytes[i] / tunIfaceTotal.rxBytes;
-                if (tunIfaceTotal.operations > 0) {
+                // app must not be blamed for more than it consumed on tunIface
-                    tmpEntry.operations =
+                totalRxBytes = Math.min(rxBytes[i], rxBytesAcrossUnderlyingIfaces);
-                            pool.operations * operations[i] / tunIfaceTotal.operations;
+            }
-                } else {
+            long totalRxPackets = 0;
-                    tmpEntry.operations = 0;
+            if (tunIfaceTotal.rxPackets > 0) {
-                }
+                final long rxPacketsAcrossUnderlyingIfaces =
-                tmpEntry.uid = uid[i];
+                        underlyingIfacesTotal.rxPackets * rxPackets[i] / tunIfaceTotal.rxPackets;
-                tmpEntry.tag = tag[i];
+                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];
-                tmpEntry.metered = metered[i];
+                if (underlyingIfacesTotal.rxBytes > 0) {
-                tmpEntry.roaming = roaming[i];
+                    tmpEntry.rxBytes =
-                tmpEntry.defaultNetwork = defaultNetwork[i];
+                            totalRxBytes
+                                    * perInterfaceTotal[j].rxBytes
+                                    / underlyingIfacesTotal.rxBytes;
+                }
+                tmpEntry.rxPackets = 0;
+                if (underlyingIfacesTotal.rxPackets > 0) {
+                    tmpEntry.rxPackets =
+                            totalRxPackets
+                                    * perInterfaceTotal[j].rxPackets
+                                    / underlyingIfacesTotal.rxPackets;
+                }
+                tmpEntry.txBytes = 0;
+                if (underlyingIfacesTotal.txBytes > 0) {
+                    tmpEntry.txBytes =
+                            totalTxBytes
+                                    * perInterfaceTotal[j].txBytes
+                                    / underlyingIfacesTotal.txBytes;
+                }
+                tmpEntry.txPackets = 0;
+                if (underlyingIfacesTotal.txPackets > 0) {
+                    tmpEntry.txPackets =
+                            totalTxPackets
+                                    * perInterfaceTotal[j].txPackets
+                                    / underlyingIfacesTotal.txPackets;
+                }
+                tmpEntry.operations = 0;
+                if (underlyingIfacesTotal.operations > 0) {
+                    tmpEntry.operations =
+                            totalOperations
+                                    * perInterfaceTotal[j].operations
+                                    / underlyingIfacesTotal.operations;
+                }
+                // tmpEntry now contains the migrated data of the i-th entry for the j-th underlying
+                // interface. Add that data usage to this object.
                 combineValues(tmpEntry);
                 if (tag[i] == TAG_NONE) {
-                    moved.add(tmpEntry);
+                    // Add the migrated data to moved so it is deducted from the VPN app later.
+                    moved[j].add(tmpEntry);
                     // Add debug info
                     tmpEntry.set = SET_DBG_VPN_IN;
                     combineValues(tmpEntry);
@@ -1311,38 +1410,45 @@ public class NetworkStats implements Parcelable {
         return moved;
     }
 
-    private void deductTrafficFromVpnApp(int tunUid, String underlyingIface, Entry moved) {
+    private void deductTrafficFromVpnApp(
-        // Add debug info
+            int tunUid,
-        moved.uid = tunUid;
+            @NonNull String[] underlyingIfaces,
-        moved.set = SET_DBG_VPN_OUT;
+            @NonNull Entry[] moved) {
-        moved.tag = TAG_NONE;
+        for (int i = 0; i < underlyingIfaces.length; i++) {
-        moved.iface = underlyingIface;
+            moved[i].uid = tunUid;
-        moved.metered = METERED_ALL;
+            // Add debug info
-        moved.roaming = ROAMING_ALL;
+            moved[i].set = SET_DBG_VPN_OUT;
-        moved.defaultNetwork = DEFAULT_NETWORK_ALL;
+            moved[i].tag = TAG_NONE;
-        combineValues(moved);
+            moved[i].iface = underlyingIfaces[i];
+            moved[i].metered = METERED_ALL;
+            moved[i].roaming = ROAMING_ALL;
+            moved[i].defaultNetwork = DEFAULT_NETWORK_ALL;
+            combineValues(moved[i]);
 
-        // Caveat: if the vpn software uses tag, the total tagged traffic may be greater than
+            // Caveat: if the vpn software uses tag, the total tagged traffic may be greater than
-        // the TAG_NONE traffic.
+            // the TAG_NONE traffic.
-        //
+            //
-        // Relies on the fact that the underlying traffic only has state ROAMING_NO and METERED_NO,
+            // Relies on the fact that the underlying traffic only has state ROAMING_NO and
-        // which should be the case as it comes directly from the /proc file. We only blend in the
+            // METERED_NO, which should be the case as it comes directly from the /proc file.
-        // roaming data after applying these adjustments, by checking the NetworkIdentity of the
+            // We only blend in the roaming data after applying these adjustments, by checking the
-        // underlying iface.
+            // NetworkIdentity of the underlying iface.
-        int idxVpnBackground = findIndex(underlyingIface, tunUid, SET_DEFAULT, TAG_NONE,
+            final int idxVpnBackground = findIndex(underlyingIfaces[i], tunUid, SET_DEFAULT,
-                METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
+                            TAG_NONE, METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
-        if (idxVpnBackground != -1) {
+            if (idxVpnBackground != -1) {
-            tunSubtract(idxVpnBackground, this, moved);
+                // Note - tunSubtract also updates moved[i]; whatever traffic that's left is removed
-        }
+                // from foreground usage.
+                tunSubtract(idxVpnBackground, this, moved[i]);
+            }
 
-        int idxVpnForeground = findIndex(underlyingIface, tunUid, SET_FOREGROUND, TAG_NONE,
+            final int idxVpnForeground = findIndex(underlyingIfaces[i], tunUid, SET_FOREGROUND,
-                METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
+                            TAG_NONE, METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO);
-        if (idxVpnForeground != -1) {
+            if (idxVpnForeground != -1) {
-            tunSubtract(idxVpnForeground, this, moved);
+                tunSubtract(idxVpnForeground, this, moved[i]);
+            }
         }
     }
 
-    private static void tunSubtract(int i, NetworkStats left, Entry right) {
+    private static void tunSubtract(int i, @NonNull NetworkStats left, @NonNull Entry right) {
         long rxBytes = Math.min(left.rxBytes[i], right.rxBytes);
         left.rxBytes[i] -= rxBytes;
         right.rxBytes -= rxBytes;

services/core/java/com/android/server/net/NetworkStatsFactory.java

@@ -16,6 +16,7 @@
 
 package com.android.server.net;
 
+import static android.net.NetworkStats.INTERFACES_ALL;
 import static android.net.NetworkStats.SET_ALL;
 import static android.net.NetworkStats.TAG_ALL;
 import static android.net.NetworkStats.TAG_NONE;
@@ -33,6 +34,7 @@ import android.os.SystemClock;
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.net.VpnInfo;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.ProcFileReader;
 
@@ -70,11 +72,25 @@ public class NetworkStatsFactory {
 
     private INetd mNetdService;
 
-    // A persistent Snapshot since device start for eBPF stats
+    /**
-    @GuardedBy("mPersistSnapshot")
+     * Guards persistent data access in this class
-    private final NetworkStats mPersistSnapshot;
+     *
+     * <p>In order to prevent deadlocks, critical sections protected by this lock SHALL NOT call out
+     * to other code that will acquire other locks within the system server. See b/134244752.
+     */
+    private static final Object sPersistentDataLock = new Object();
+
+    /** Set containing info about active VPNs and their underlying networks. */
+    private static volatile VpnInfo[] sVpnInfos = new VpnInfo[0];
+
+    // A persistent snapshot of cumulative stats since device start
+    @GuardedBy("sPersistentDataLock")
+    private NetworkStats mPersistSnapshot;
+
+    // The persistent snapshot of tun and 464xlat adjusted stats since device start
+    @GuardedBy("sPersistentDataLock")
+    private NetworkStats mTunAnd464xlatAdjustedStats;
 
-    // TODO: only do adjustments in NetworkStatsService and remove this.
     /**
      * (Stacked interface) -> (base interface) association for all connected ifaces since boot.
      *
@@ -90,6 +106,24 @@ public class NetworkStatsFactory {
         }
     }
 
+    /**
+     * Set active VPN information for data usage migration purposes
+     *
+     * <p>Traffic on TUN-based VPNs inherently all appear to be originated from the VPN providing
+     * app's UID. This method is used to support migration of VPN data usage, ensuring data is
+     * accurately billed to the real owner of the traffic.
+     *
+     * @param vpnArray The snapshot of the currently-running VPNs.
+     */
+    public static void updateVpnInfos(VpnInfo[] vpnArray) {
+        sVpnInfos = vpnArray.clone();
+    }
+
+    @VisibleForTesting
+    public static VpnInfo[] getVpnInfos() {
+        return sVpnInfos.clone();
+    }
+
     /**
      * Get a set of interfaces containing specified ifaces and stacked interfaces.
      *
@@ -146,6 +180,7 @@ public class NetworkStatsFactory {
         mStatsXtUid = new File(procRoot, "net/xt_qtaguid/stats");
         mUseBpfStats = useBpfStats;
         mPersistSnapshot = new NetworkStats(SystemClock.elapsedRealtime(), -1);
+        mTunAnd464xlatAdjustedStats = new NetworkStats(SystemClock.elapsedRealtime(), -1);
     }
 
     public NetworkStats readBpfNetworkStatsDev() throws IOException {
@@ -264,22 +299,24 @@ public class NetworkStatsFactory {
     }
 
     public NetworkStats readNetworkStatsDetail() throws IOException {
-        return readNetworkStatsDetail(UID_ALL, null, TAG_ALL, null);
+        return readNetworkStatsDetail(UID_ALL, INTERFACES_ALL, TAG_ALL);
     }
 
-    public NetworkStats readNetworkStatsDetail(int limitUid, String[] limitIfaces, int limitTag,
+    /**
-            NetworkStats lastStats) throws IOException {
+     * Reads the detailed UID stats based on the provided parameters
-        final NetworkStats stats =
+     *
-              readNetworkStatsDetailInternal(limitUid, limitIfaces, limitTag, lastStats);
+     * @param limitUid the UID to limit this query to
-
+     * @param limitIfaces the interfaces to limit this query to. Use {@link
-        // No locking here: apply464xlatAdjustments behaves fine with an add-only ConcurrentHashMap.
+     *     NetworkStats.INTERFACES_ALL} to select all interfaces
-        // TODO: remove this and only apply adjustments in NetworkStatsService.
+     * @param limitTag the tags to limit this query to
-        stats.apply464xlatAdjustments(sStackedIfaces, mUseBpfStats);
+     * @return the NetworkStats instance containing network statistics at the present time.
-
+     */
-        return stats;
+    public NetworkStats readNetworkStatsDetail(
+            int limitUid, @Nullable String[] limitIfaces, int limitTag) throws IOException {
+        return readNetworkStatsDetailInternal(limitUid, limitIfaces, limitTag);
     }
 
-    @GuardedBy("mPersistSnapshot")
+    @GuardedBy("sPersistentDataLock")
     private void requestSwapActiveStatsMapLocked() throws RemoteException {
         // Ask netd to do a active map stats swap. When the binder call successfully returns,
         // the system server should be able to safely read and clean the inactive map
@@ -292,19 +329,20 @@ public class NetworkStatsFactory {
         }
     }
 
-    // TODO: delete the lastStats parameter
+    private NetworkStats readNetworkStatsDetailInternal(
-    private NetworkStats readNetworkStatsDetailInternal(int limitUid, String[] limitIfaces,
+            int limitUid, String[] limitIfaces, int limitTag) throws IOException {
-            int limitTag, NetworkStats lastStats) throws IOException {
+        // In order to prevent deadlocks, anything protected by this lock MUST NOT call out to other
-        if (USE_NATIVE_PARSING) {
+        // code that will acquire other locks within the system server. See b/134244752.
-            final NetworkStats stats;
+        synchronized (sPersistentDataLock) {
-            if (lastStats != null) {
+            // Take a reference. If this gets swapped out, we still have the old reference.
-                stats = lastStats;
+            final VpnInfo[] vpnArray = sVpnInfos;
-                stats.setElapsedRealtime(SystemClock.elapsedRealtime());
+            // Take a defensive copy. mPersistSnapshot is mutated in some cases below
-            } else {
+            final NetworkStats prev = mPersistSnapshot.clone();
-                stats = new NetworkStats(SystemClock.elapsedRealtime(), -1);
+
-            }
+            if (USE_NATIVE_PARSING) {
-            if (mUseBpfStats) {
+                final NetworkStats stats =
-                synchronized (mPersistSnapshot) {
+                        new NetworkStats(SystemClock.elapsedRealtime(), 0 /* initialSize */);
+                if (mUseBpfStats) {
                     try {
                         requestSwapActiveStatsMapLocked();
                     } catch (RemoteException e) {
@@ -313,32 +351,66 @@ public class NetworkStatsFactory {
                     // Stats are always read from the inactive map, so they must be read after the
                     // swap
                     if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), UID_ALL,
-                            null, TAG_ALL, mUseBpfStats) != 0) {
+                            INTERFACES_ALL, TAG_ALL, mUseBpfStats) != 0) {
                         throw new IOException("Failed to parse network stats");
                     }
+
+                    // BPF stats are incremental; fold into mPersistSnapshot.
                     mPersistSnapshot.setElapsedRealtime(stats.getElapsedRealtime());
                     mPersistSnapshot.combineAllValues(stats);
-                    NetworkStats result = mPersistSnapshot.clone();
+                } else {
-                    result.filter(limitUid, limitIfaces, limitTag);
+                    if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), UID_ALL,
-                    return result;
+                            INTERFACES_ALL, TAG_ALL, mUseBpfStats) != 0) {
+                        throw new IOException("Failed to parse network stats");
+                    }
+                    if (SANITY_CHECK_NATIVE) {
+                        final NetworkStats javaStats = javaReadNetworkStatsDetail(mStatsXtUid,
+                                UID_ALL, INTERFACES_ALL, TAG_ALL);
+                        assertEquals(javaStats, stats);
+                    }
+
+                    mPersistSnapshot = stats;
                 }
             } else {
-                if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), limitUid,
+                mPersistSnapshot = javaReadNetworkStatsDetail(mStatsXtUid, UID_ALL, INTERFACES_ALL,
-                        limitIfaces, limitTag, mUseBpfStats) != 0) {
+                        TAG_ALL);
-                    throw new IOException("Failed to parse network stats");
-                }
-                if (SANITY_CHECK_NATIVE) {
-                    final NetworkStats javaStats = javaReadNetworkStatsDetail(mStatsXtUid, limitUid,
-                            limitIfaces, limitTag);
-                    assertEquals(javaStats, stats);
-                }
-                return stats;
             }
-        } else {
+
-            return javaReadNetworkStatsDetail(mStatsXtUid, limitUid, limitIfaces, limitTag);
+            NetworkStats adjustedStats = adjustForTunAnd464Xlat(mPersistSnapshot, prev, vpnArray);
+
+            // Filter return values
+            adjustedStats.filter(limitUid, limitIfaces, limitTag);
+            return adjustedStats;
         }
     }
 
+    @GuardedBy("sPersistentDataLock")
+    private NetworkStats adjustForTunAnd464Xlat(
+            NetworkStats uidDetailStats, NetworkStats previousStats, VpnInfo[] vpnArray) {
+        // Calculate delta from last snapshot
+        final NetworkStats delta = uidDetailStats.subtract(previousStats);
+
+        // Apply 464xlat adjustments before VPN adjustments. If VPNs are using v4 on a v6 only
+        // network, the overhead is their fault.
+        // No locking here: apply464xlatAdjustments behaves fine with an add-only
+        // ConcurrentHashMap.
+        delta.apply464xlatAdjustments(sStackedIfaces, mUseBpfStats);
+
+        // Migrate data usage over a VPN to the TUN network.
+        for (VpnInfo info : vpnArray) {
+            delta.migrateTun(info.ownerUid, info.vpnIface, info.underlyingIfaces);
+        }
+
+        // Filter out debug entries as that may lead to over counting.
+        delta.filterDebugEntries();
+
+        // Update mTunAnd464xlatAdjustedStats with migrated delta.
+        mTunAnd464xlatAdjustedStats.combineAllValues(delta);
+        mTunAnd464xlatAdjustedStats.setElapsedRealtime(uidDetailStats.getElapsedRealtime());
+
+        return mTunAnd464xlatAdjustedStats.clone();
+    }
+
     /**
      * Parse and return {@link NetworkStats} with UID-level details. Values are
      * expected to monotonically increase since device boot.

services/core/java/com/android/server/net/NetworkStatsObservers.java

@@ -39,7 +39,6 @@ import android.util.Slog;
 import android.util.SparseArray;
 
 import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.net.VpnInfo;
 
 import java.util.concurrent.atomic.AtomicInteger;
 
@@ -104,9 +103,9 @@ class NetworkStatsObservers {
     public void updateStats(NetworkStats xtSnapshot, NetworkStats uidSnapshot,
                 ArrayMap<String, NetworkIdentitySet> activeIfaces,
                 ArrayMap<String, NetworkIdentitySet> activeUidIfaces,
-                VpnInfo[] vpnArray, long currentTime) {
+                long currentTime) {
         StatsContext statsContext = new StatsContext(xtSnapshot, uidSnapshot, activeIfaces,
-                activeUidIfaces, vpnArray, currentTime);
+                activeUidIfaces, currentTime);
         getHandler().sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATS, statsContext));
     }
 
@@ -354,7 +353,7 @@ class NetworkStatsObservers {
             // thread will update it. We pass a null VPN array because usage is aggregated by uid
             // for this snapshot, so VPN traffic can't be reattributed to responsible apps.
             mRecorder.recordSnapshotLocked(statsContext.mXtSnapshot, statsContext.mActiveIfaces,
-                    null /* vpnArray */, statsContext.mCurrentTime);
+                    statsContext.mCurrentTime);
         }
 
         /**
@@ -396,7 +395,7 @@ class NetworkStatsObservers {
             // thread will update it. We pass the VPN info so VPN traffic is reattributed to
             // responsible apps.
             mRecorder.recordSnapshotLocked(statsContext.mUidSnapshot, statsContext.mActiveUidIfaces,
-                    statsContext.mVpnArray, statsContext.mCurrentTime);
+                    statsContext.mCurrentTime);
         }
 
         /**
@@ -427,18 +426,16 @@ class NetworkStatsObservers {
         NetworkStats mUidSnapshot;
         ArrayMap<String, NetworkIdentitySet> mActiveIfaces;
         ArrayMap<String, NetworkIdentitySet> mActiveUidIfaces;
-        VpnInfo[] mVpnArray;
         long mCurrentTime;
 
         StatsContext(NetworkStats xtSnapshot, NetworkStats uidSnapshot,
                 ArrayMap<String, NetworkIdentitySet> activeIfaces,
                 ArrayMap<String, NetworkIdentitySet> activeUidIfaces,
-                VpnInfo[] vpnArray, long currentTime) {
+                long currentTime) {
             mXtSnapshot = xtSnapshot;
             mUidSnapshot = uidSnapshot;
             mActiveIfaces = activeIfaces;
             mActiveUidIfaces = activeUidIfaces;
-            mVpnArray = vpnArray;
             mCurrentTime = currentTime;
         }
     }

services/core/java/com/android/server/net/NetworkStatsRecorder.java

@@ -23,7 +23,6 @@ import static android.text.format.DateUtils.YEAR_IN_MILLIS;
 
 import static com.android.internal.util.Preconditions.checkNotNull;
 
-import android.annotation.Nullable;
 import android.net.NetworkStats;
 import android.net.NetworkStats.NonMonotonicObserver;
 import android.net.NetworkStatsHistory;
@@ -37,14 +36,13 @@ import android.util.MathUtils;
 import android.util.Slog;
 import android.util.proto.ProtoOutputStream;
 
-import com.android.internal.net.VpnInfo;
 import com.android.internal.util.FileRotator;
 import com.android.internal.util.IndentingPrintWriter;
 
-import libcore.io.IoUtils;
-
 import com.google.android.collect.Sets;
 
+import libcore.io.IoUtils;
+
 import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
 import java.io.File;
@@ -202,18 +200,12 @@ public class NetworkStatsRecorder {
     }
 
     /**
-     * Record any delta that occurred since last {@link NetworkStats} snapshot,
+     * Record any delta that occurred since last {@link NetworkStats} snapshot, using the given
-     * using the given {@link Map} to identify network interfaces. First
+     * {@link Map} to identify network interfaces. First snapshot is considered bootstrap, and is
-     * snapshot is considered bootstrap, and is not counted as delta.
+     * not counted as delta.
-     *
-     * @param vpnArray Optional info about the currently active VPN, if any. This is used to
-     *                 redistribute traffic from the VPN app to the underlying responsible apps.
-     *                 This should always be set to null if the provided snapshot is aggregated
-     *                 across all UIDs (e.g. contains UID_ALL buckets), regardless of VPN state.
      */
     public void recordSnapshotLocked(NetworkStats snapshot,
-            Map<String, NetworkIdentitySet> ifaceIdent, @Nullable VpnInfo[] vpnArray,
+            Map<String, NetworkIdentitySet> ifaceIdent, long currentTimeMillis) {
-            long currentTimeMillis) {
         final HashSet<String> unknownIfaces = Sets.newHashSet();
 
         // skip recording when snapshot missing
@@ -232,12 +224,6 @@ public class NetworkStatsRecorder {
         final long end = currentTimeMillis;
         final long start = end - delta.getElapsedRealtime();
 
-        if (vpnArray != null) {
-            for (VpnInfo info : vpnArray) {
-                delta.migrateTun(info.ownerUid, info.vpnIface, info.primaryUnderlyingIface);
-            }
-        }
-
         NetworkStats.Entry entry = null;
         for (int i = 0; i < delta.size(); i++) {
             entry = delta.getValues(i, entry);

services/core/java/com/android/server/net/NetworkStatsService.java

@@ -131,7 +131,6 @@ import android.util.proto.ProtoOutputStream;
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.net.VpnInfo;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.DumpUtils;
 import com.android.internal.util.FileRotator;
@@ -267,10 +266,6 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     @GuardedBy("mStatsLock")
     private Network[] mDefaultNetworks = new Network[0];
 
-    /** Set containing info about active VPNs and their underlying networks. */
-    @GuardedBy("mStatsLock")
-    private VpnInfo[] mVpnInfos = new VpnInfo[0];
-
     private final DropBoxNonMonotonicObserver mNonMonotonicObserver =
             new DropBoxNonMonotonicObserver();
 
@@ -864,7 +859,6 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     @Override
     public void forceUpdateIfaces(
             Network[] defaultNetworks,
-            VpnInfo[] vpnArray,
             NetworkState[] networkStates,
             String activeIface) {
         checkNetworkStackPermission(mContext);
@@ -872,7 +866,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
 
         final long token = Binder.clearCallingIdentity();
         try {
-            updateIfaces(defaultNetworks, vpnArray, networkStates, activeIface);
+            updateIfaces(defaultNetworks, networkStates, activeIface);
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -1138,13 +1132,11 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
 
     private void updateIfaces(
             Network[] defaultNetworks,
-            VpnInfo[] vpnArray,
             NetworkState[] networkStates,
             String activeIface) {
         synchronized (mStatsLock) {
             mWakeLock.acquire();
             try {
-                mVpnInfos = vpnArray;
                 mActiveIface = activeIface;
                 updateIfacesLocked(defaultNetworks, networkStates);
             } finally {
@@ -1154,10 +1146,9 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     }
 
     /**
-     * Inspect all current {@link NetworkState} to derive mapping from {@code
+     * Inspect all current {@link NetworkState} to derive mapping from {@code iface} to {@link
-     * iface} to {@link NetworkStatsHistory}. When multiple {@link NetworkInfo}
+     * NetworkStatsHistory}. When multiple {@link NetworkInfo} are active on a single {@code iface},
-     * are active on a single {@code iface}, they are combined under a single
+     * they are combined under a single {@link NetworkIdentitySet}.
-     * {@link NetworkIdentitySet}.
      */
     @GuardedBy("mStatsLock")
     private void updateIfacesLocked(Network[] defaultNetworks, NetworkState[] states) {
@@ -1274,27 +1265,24 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         // For xt/dev, we pass a null VPN array because usage is aggregated by UID, so VPN traffic
         // can't be reattributed to responsible apps.
         Trace.traceBegin(TRACE_TAG_NETWORK, "recordDev");
-        mDevRecorder.recordSnapshotLocked(
+        mDevRecorder.recordSnapshotLocked(devSnapshot, mActiveIfaces, currentTime);
-                devSnapshot, mActiveIfaces, null /* vpnArray */, currentTime);
         Trace.traceEnd(TRACE_TAG_NETWORK);
         Trace.traceBegin(TRACE_TAG_NETWORK, "recordXt");
-        mXtRecorder.recordSnapshotLocked(
+        mXtRecorder.recordSnapshotLocked(xtSnapshot, mActiveIfaces, currentTime);
-                xtSnapshot, mActiveIfaces, null /* vpnArray */, currentTime);
         Trace.traceEnd(TRACE_TAG_NETWORK);
 
         // For per-UID stats, pass the VPN info so VPN traffic is reattributed to responsible apps.
-        VpnInfo[] vpnArray = mVpnInfos;
         Trace.traceBegin(TRACE_TAG_NETWORK, "recordUid");
-        mUidRecorder.recordSnapshotLocked(uidSnapshot, mActiveUidIfaces, vpnArray, currentTime);
+        mUidRecorder.recordSnapshotLocked(uidSnapshot, mActiveUidIfaces, currentTime);
         Trace.traceEnd(TRACE_TAG_NETWORK);
         Trace.traceBegin(TRACE_TAG_NETWORK, "recordUidTag");
-        mUidTagRecorder.recordSnapshotLocked(uidSnapshot, mActiveUidIfaces, vpnArray, currentTime);
+        mUidTagRecorder.recordSnapshotLocked(uidSnapshot, mActiveUidIfaces, currentTime);
         Trace.traceEnd(TRACE_TAG_NETWORK);
 
         // We need to make copies of member fields that are sent to the observer to avoid
         // a race condition between the service handler thread and the observer's
         mStatsObservers.updateStats(xtSnapshot, uidSnapshot, new ArrayMap<>(mActiveIfaces),
-                new ArrayMap<>(mActiveUidIfaces), vpnArray, currentTime);
+                new ArrayMap<>(mActiveUidIfaces), currentTime);
     }
 
     /**
@@ -1667,8 +1655,6 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
      */
     private NetworkStats getNetworkStatsUidDetail(String[] ifaces)
             throws RemoteException {
-
-        // TODO: remove 464xlat adjustments from NetworkStatsFactory and apply all at once here.
         final NetworkStats uidSnapshot = mNetworkManager.getNetworkStatsUidDetail(UID_ALL,
                 ifaces);