Fix network usage stats on 464xlat tethered. (9fb55e4f) · Commits · e / os / android_frameworks_base

core/java/android/net/NetworkStats.java

+75 −0

Original line number	Diff line number	Diff line
		@@ -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

		/**
		@@ -751,6 +757,75 @@ 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

+13 −47

Original line number	Diff line number	Diff line
		@@ -54,11 +54,6 @@ 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}. */
		@@ -94,7 +89,7 @@ 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;
		}
		@@ -116,6 +111,15 @@ 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();
		@@ -287,48 +291,10 @@ 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

		// 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).
		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);

		// No locking here: apply464xlatAdjustments behaves fine with an add-only ConcurrentHashMap.
		// TODO: remove this and only apply adjustments in NetworkStatsService.
		stats.apply464xlatAdjustments(sStackedIfaces);

		return stats;
		}

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

+4 −4

Original line number	Diff line number	Diff line
		@@ -146,7 +146,6 @@ import java.io.PrintWriter;
		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
		@@ -756,7 +755,7 @@ 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);
		@@ -1490,12 +1489,14 @@ 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(
		@@ -1505,13 +1506,12 @@ 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;
		}

tests/net/java/android/net/NetworkStatsTest.java

+84 −0

Original line number	Diff line number	Diff line
		@@ -39,8 +39,10 @@ import static org.junit.Assert.assertEquals;
		import static org.junit.Assert.assertTrue;
		import static org.junit.Assert.fail;

		import android.os.Process;
		import android.support.test.runner.AndroidJUnit4;
		import android.support.test.filters.SmallTest;
		import android.util.ArrayMap;

		import com.google.android.collect.Sets;

		@@ -773,6 +775,88 @@ public class NetworkStatsTest {
		assertEquals(entry2, stats.getValues(1, null));
		}

		@Test
		public void testApply464xlatAdjustments() {
		final String v4Iface = "v4-wlan0";
		final String baseIface = "wlan0";
		final String otherIface = "other";
		final int appUid = 10001;
		final int rootUid = Process.ROOT_UID;
		ArrayMap<String, String> stackedIface = new ArrayMap<>();
		stackedIface.put(v4Iface, baseIface);

		NetworkStats.Entry otherEntry = new NetworkStats.Entry(
		otherIface, appUid, SET_DEFAULT, TAG_NONE,
		2600 /* rxBytes */,
		2 /* rxPackets */,
		3800 /* txBytes */,
		3 /* txPackets */,
		0 /* operations */);

		NetworkStats stats = new NetworkStats(TEST_START, 3)
		.addValues(v4Iface, appUid, SET_DEFAULT, TAG_NONE,
		30501490 /* rxBytes */,
		22401 /* rxPackets */,
		876235 /* txBytes */,
		13805 /* txPackets */,
		0 /* operations */)
		.addValues(baseIface, rootUid, SET_DEFAULT, TAG_NONE,
		31113087,
		22588,
		1169942,
		13902,
		0)
		.addValues(otherEntry);

		stats.apply464xlatAdjustments(stackedIface);

		assertEquals(3, stats.size());
		assertValues(stats, 0, v4Iface, appUid, SET_DEFAULT, TAG_NONE,
		METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO,
		30949510,
		22401,
		1152335,
		13805,
		0);
		assertValues(stats, 1, baseIface, 0, SET_DEFAULT, TAG_NONE,
		METERED_NO, ROAMING_NO, DEFAULT_NETWORK_NO,
		163577,
		187,
		17607,
		97,
		0);
		assertEquals(otherEntry, stats.getValues(2, null));
		}

		@Test
		public void testApply464xlatAdjustments_noStackedIface() {
		NetworkStats.Entry firstEntry = new NetworkStats.Entry(
		"if1", 10002, SET_DEFAULT, TAG_NONE,
		2600 /* rxBytes */,
		2 /* rxPackets */,
		3800 /* txBytes */,
		3 /* txPackets */,
		0 /* operations */);
		NetworkStats.Entry secondEntry = new NetworkStats.Entry(
		"if2", 10002, SET_DEFAULT, TAG_NONE,
		5000 /* rxBytes */,
		3 /* rxPackets */,
		6000 /* txBytes */,
		4 /* txPackets */,
		0 /* operations */);

		NetworkStats stats = new NetworkStats(TEST_START, 2)
		.addValues(firstEntry)
		.addValues(secondEntry);

		// Empty map: no adjustment
		stats.apply464xlatAdjustments(new ArrayMap<>());

		assertEquals(2, stats.size());
		assertEquals(firstEntry, stats.getValues(0, null));
		assertEquals(secondEntry, stats.getValues(1, null));
		}

		private static void assertContains(NetworkStats stats, String iface, int uid, int set,
		int tag, int metered, int roaming, int defaultNetwork, long rxBytes, long rxPackets,
		long txBytes, long txPackets, long operations) {