Add method to NetworkStatsService for UID stats.

Useful for clients such as BatteryStats which currently rely
on NetworkStatsFactory. Data at that stage is incomplete as
it does not account for tethering, VT data and corresponding
464xlat corrections.

Test: runtest frameworks-net, CTS tests pass.
Bug: b/72107146
Merged-In: I31c5b9b4a7c6e72910152415894a137f000a5858
Merged-In: I2527d95000c7500c824ede70f87ecb38e21ed323
(cherry picked from aosp 088ff6824f13145ea52207bdead0d7e454a6f3ce)

Change-Id: Ie80f1bb21124241f3414f9be77aceac9a44ec6d1

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();
 

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;
+        setValues(size, entry);
-        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;
         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);

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.Arrays;
-import java.util.Objects;
+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.
+    // TODO: only do adjustments in NetworkStatsService and remove this.
-    @GuardedBy("sStackedIfaces")
+    /**
-    private static final ArrayMap<String, String> sStackedIfaces = new ArrayMap<>();
+     * (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 (stackedIface != null && baseIface != null) {
-            if (baseIface != null) {
+            sStackedIfaces.put(stackedIface, baseIface);
-                sStackedIfaces.put(stackedIface, baseIface);
+        }
-            } else {
+    }
-                sStackedIfaces.remove(stackedIface);
+
+    /**
+     * 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;
             }

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 {
+    private NetworkStats getNetworkStatsUidDetail(String[] ifaces)
-        final NetworkStats uidSnapshot = mNetworkManager.getNetworkStatsUidDetail(UID_ALL);
+            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;
     }