Merge "Fix network usage stats on 464xlat tethered." into pi-dev

core/java/android/net/NetworkStats.java

@@ -31,6 +31,7 @@ import java.io.CharArrayWriter;
 import java.io.PrintWriter;
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Objects;
 
 /**
@@ -97,6 +98,11 @@ public class NetworkStats implements Parcelable {
     /** Denotes a request for stats at the interface and UID level. */
     public static final int STATS_PER_UID = 1;
 
+    private static final String CLATD_INTERFACE_PREFIX = "v4-";
+    // Delta between IPv4 header (20b) and IPv6 header (40b).
+    // Used for correct stats accounting on clatd interfaces.
+    private static final int IPV4V6_HEADER_DELTA = 20;
+
     // TODO: move fields to "mVariable" notation
 
     /**
@@ -758,6 +764,75 @@ public class NetworkStats implements Parcelable {
         return result;
     }
 
+    /**
+     * Calculate and apply adjustments to captured statistics for 464xlat traffic counted twice.
+     *
+     * <p>This mutates both base and stacked traffic stats, to account respectively for
+     * double-counted traffic and IPv4/IPv6 header size difference.
+     *
+     * <p>For 464xlat traffic, xt_qtaguid sees every IPv4 packet twice, once as a native IPv4
+     * packet on the stacked interface, and once as translated to an IPv6 packet on the
+     * base interface. For correct stats accounting on the base interface, every 464xlat
+     * packet needs to be subtracted from the root UID on the base interface both for tx
+     * and rx traffic (http://b/12249687, http:/b/33681750).
+     *
+     * <p>This method will behave fine if {@code stackedIfaces} is an non-synchronized but add-only
+     * {@code ConcurrentHashMap}
+     * @param baseTraffic Traffic on the base interfaces. Will be mutated.
+     * @param stackedTraffic Stats with traffic stacked on top of our ifaces. Will also be mutated.
+     * @param stackedIfaces Mapping ipv6if -> ipv4if interface where traffic is counted on both.
+     */
+    public static void apply464xlatAdjustments(NetworkStats baseTraffic,
+            NetworkStats stackedTraffic, Map<String, String> stackedIfaces) {
+        // Total 464xlat traffic to subtract from uid 0 on all base interfaces.
+        // stackedIfaces may grow afterwards, but NetworkStats will just be resized automatically.
+        final NetworkStats adjustments = new NetworkStats(0, stackedIfaces.size());
+
+        // For recycling
+        Entry entry = null;
+        Entry adjust = new NetworkStats.Entry(IFACE_ALL, 0, 0, 0, 0, 0, 0, 0L, 0L, 0L, 0L, 0L);
+
+        for (int i = 0; i < stackedTraffic.size; i++) {
+            entry = stackedTraffic.getValues(i, entry);
+            if (entry.iface == null || !entry.iface.startsWith(CLATD_INTERFACE_PREFIX)) {
+                continue;
+            }
+            final String baseIface = stackedIfaces.get(entry.iface);
+            if (baseIface == null) {
+                continue;
+            }
+            // Subtract any 464lat traffic seen for the root UID on the current base interface.
+            adjust.iface = baseIface;
+            adjust.rxBytes = -(entry.rxBytes + entry.rxPackets * IPV4V6_HEADER_DELTA);
+            adjust.txBytes = -(entry.txBytes + entry.txPackets * IPV4V6_HEADER_DELTA);
+            adjust.rxPackets = -entry.rxPackets;
+            adjust.txPackets = -entry.txPackets;
+            adjustments.combineValues(adjust);
+
+            // For 464xlat traffic, xt_qtaguid only counts the bytes of the native IPv4 packet sent
+            // on the stacked interface with prefix "v4-" and drops the IPv6 header size after
+            // unwrapping. To account correctly for on-the-wire traffic, add the 20 additional bytes
+            // difference for all packets (http://b/12249687, http:/b/33681750).
+            entry.rxBytes += entry.rxPackets * IPV4V6_HEADER_DELTA;
+            entry.txBytes += entry.txPackets * IPV4V6_HEADER_DELTA;
+            stackedTraffic.setValues(i, entry);
+        }
+
+        baseTraffic.combineAllValues(adjustments);
+    }
+
+    /**
+     * Calculate and apply adjustments to captured statistics for 464xlat traffic counted twice.
+     *
+     * <p>This mutates the object this method is called on. Equivalent to calling
+     * {@link #apply464xlatAdjustments(NetworkStats, NetworkStats, Map)} with {@code this} as
+     * base and stacked traffic.
+     * @param stackedIfaces Mapping ipv6if -> ipv4if interface where traffic is counted on both.
+     */
+    public void apply464xlatAdjustments(Map<String, String> stackedIfaces) {
+        apply464xlatAdjustments(this, this, stackedIfaces);
+    }
+
     /**
      * Return total statistics grouped by {@link #iface}; doesn't mutate the
      * original structure.

core/java/com/android/internal/net/NetworkStatsFactory.java

@@ -56,11 +56,6 @@ public class NetworkStatsFactory {
     private static final boolean USE_NATIVE_PARSING = true;
     private static final boolean SANITY_CHECK_NATIVE = false;
 
-    private static final String CLATD_INTERFACE_PREFIX = "v4-";
-    // Delta between IPv4 header (20b) and IPv6 header (40b).
-    // Used for correct stats accounting on clatd interfaces.
-    private static final int IPV4V6_HEADER_DELTA = 20;
-
     /** Path to {@code /proc/net/dev}. */
     private final File mStatsIfaceDev;
     /** Path to {@code /proc/net/xt_qtaguid/iface_stat_all}. */
@@ -96,7 +91,7 @@ public class NetworkStatsFactory {
      * {@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) {
+    public static String[] augmentWithStackedInterfaces(@Nullable String[] requiredIfaces) {
         if (requiredIfaces == NetworkStats.INTERFACES_ALL) {
             return null;
         }
@@ -118,6 +113,15 @@ public class NetworkStatsFactory {
         return relatedIfaces.toArray(outArray);
     }
 
+    /**
+     * Applies 464xlat adjustments with ifaces noted with {@link #noteStackedIface(String, String)}.
+     * @see NetworkStats#apply464xlatAdjustments(NetworkStats, NetworkStats, Map)
+     */
+    public static void apply464xlatAdjustments(NetworkStats baseTraffic,
+            NetworkStats stackedTraffic) {
+        NetworkStats.apply464xlatAdjustments(baseTraffic, stackedTraffic, sStackedIfaces);
+    }
+
     @VisibleForTesting
     public static void clearStackedIfaces() {
         sStackedIfaces.clear();
@@ -289,48 +293,10 @@ public class NetworkStatsFactory {
             NetworkStats lastStats) throws IOException {
         final NetworkStats stats =
               readNetworkStatsDetailInternal(limitUid, limitIfaces, limitTag, lastStats);
-        // Total 464xlat traffic to subtract from uid 0 on all base interfaces.
-        // 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
+        // No locking here: apply464xlatAdjustments behaves fine with an add-only ConcurrentHashMap.
-
+        // TODO: remove this and only apply adjustments in NetworkStatsService.
-        // For 464xlat traffic, xt_qtaguid sees every IPv4 packet twice, once as a native IPv4
+        stats.apply464xlatAdjustments(sStackedIfaces);
-        // packet on the stacked interface, and once as translated to an IPv6 packet on the
-        // base interface. For correct stats accounting on the base interface, every 464xlat
-        // packet needs to be subtracted from the root UID on the base interface both for tx
-        // and rx traffic (http://b/12249687, http:/b/33681750).
-        for (int i = 0; i < stats.size(); i++) {
-            entry = stats.getValues(i, entry);
-            if (entry.iface == null || !entry.iface.startsWith(CLATD_INTERFACE_PREFIX)) {
-                continue;
-            }
-            final String baseIface = sStackedIfaces.get(entry.iface);
-            if (baseIface == null) {
-                continue;
-            }
-
-            NetworkStats.Entry adjust =
-                    new NetworkStats.Entry(baseIface, 0, 0, 0, 0, 0, 0, 0L, 0L, 0L, 0L, 0L);
-            // Subtract any 464lat traffic seen for the root UID on the current base interface.
-            adjust.rxBytes -= (entry.rxBytes + entry.rxPackets * IPV4V6_HEADER_DELTA);
-            adjust.txBytes -= (entry.txBytes + entry.txPackets * IPV4V6_HEADER_DELTA);
-            adjust.rxPackets -= entry.rxPackets;
-            adjust.txPackets -= entry.txPackets;
-            adjustments.combineValues(adjust);
-
-            // For 464xlat traffic, xt_qtaguid only counts the bytes of the native IPv4 packet sent
-            // on the stacked interface with prefix "v4-" and drops the IPv6 header size after
-            // unwrapping. To account correctly for on-the-wire traffic, add the 20 additional bytes
-            // difference for all packets (http://b/12249687, http:/b/33681750).
-            entry.rxBytes = entry.rxPackets * IPV4V6_HEADER_DELTA;
-            entry.txBytes = entry.txPackets * IPV4V6_HEADER_DELTA;
-            entry.rxPackets = 0;
-            entry.txPackets = 0;
-            stats.combineValues(entry);
-        }
-
-        stats.combineAllValues(adjustments);
 
         return stats;
     }

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

@@ -148,7 +148,6 @@ 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
@@ -769,7 +768,7 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
     public NetworkStats getDetailedUidStats(String[] requiredIfaces) {
         try {
             final String[] ifacesToQuery =
-                    NetworkStatsFactory.augmentWithStackedInterfacesLocked(requiredIfaces);
+                    NetworkStatsFactory.augmentWithStackedInterfaces(requiredIfaces);
             return getNetworkStatsUidDetail(ifacesToQuery);
         } catch (RemoteException e) {
             Log.wtf(TAG, "Error compiling UID stats", e);
@@ -1527,12 +1526,14 @@ 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);
 
         // fold tethering stats and operations into uid snapshot
         final NetworkStats tetherSnapshot = getNetworkStatsTethering(STATS_PER_UID);
         tetherSnapshot.filter(UID_ALL, ifaces, TAG_ALL);
+        NetworkStatsFactory.apply464xlatAdjustments(uidSnapshot, tetherSnapshot);
         uidSnapshot.combineAllValues(tetherSnapshot);
 
         final TelephonyManager telephonyManager = (TelephonyManager) mContext.getSystemService(
@@ -1542,13 +1543,12 @@ public class NetworkStatsService extends INetworkStatsService.Stub {
         final NetworkStats vtStats = telephonyManager.getVtDataUsage(STATS_PER_UID);
         if (vtStats != null) {
             vtStats.filter(UID_ALL, ifaces, TAG_ALL);
+            NetworkStatsFactory.apply464xlatAdjustments(uidSnapshot, vtStats);
             uidSnapshot.combineAllValues(vtStats);
         }
 
         uidSnapshot.combineAllValues(mUidOperations);
 
-        // TODO: apply tethering & VC 464xlat adjustments here
-
         return uidSnapshot;
     }