[BOT.2] Create a coordinator and stats provider to provide tether stats
Make BPF tethering offload coordinator, BpfCoordinator,
registers a network stats provider, BpfTetherStatsProvider, and
provide the tethering stats from the BPF map.
Bug: 150736748
Test: new test BpfCoordinatorTest
Original-Change: https://android-review.googlesource.com/1256189
Merged-In: I22e71f87b67668f7e733e4f215d93bf5b2c9380d
Change-Id: I22e71f87b67668f7e733e4f215d93bf5b2c9380d
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 3fd9ee9..5f182a9 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -65,6 +65,7 @@
import com.android.internal.util.MessageUtils;
import com.android.internal.util.State;
import com.android.internal.util.StateMachine;
+import com.android.networkstack.tethering.BpfCoordinator;
import com.android.networkstack.tethering.PrivateAddressCoordinator;
import java.io.IOException;
@@ -225,6 +226,8 @@
private final SharedLog mLog;
private final INetd mNetd;
+ @NonNull
+ private final BpfCoordinator mBpfCoordinator;
private final Callback mCallback;
private final InterfaceController mInterfaceCtrl;
private final PrivateAddressCoordinator mPrivateAddressCoordinator;
@@ -314,11 +317,13 @@
// object. It helps to reduce the arguments of the constructor.
public IpServer(
String ifaceName, Looper looper, int interfaceType, SharedLog log,
- INetd netd, Callback callback, boolean usingLegacyDhcp, boolean usingBpfOffload,
+ INetd netd, @NonNull BpfCoordinator coordinator, Callback callback,
+ boolean usingLegacyDhcp, boolean usingBpfOffload,
PrivateAddressCoordinator addressCoordinator, Dependencies deps) {
super(ifaceName, looper);
mLog = log.forSubComponent(ifaceName);
mNetd = netd;
+ mBpfCoordinator = coordinator;
mCallback = callback;
mInterfaceCtrl = new InterfaceController(ifaceName, mNetd, mLog);
mIfaceName = ifaceName;
@@ -749,6 +754,14 @@
}
upstreamIfindex = mDeps.getIfindex(upstreamIface);
+
+ // Add upstream index to name mapping for the tether stats usage in the coordinator.
+ // Although this mapping could be added by both class Tethering and IpServer, adding
+ // mapping from IpServer guarantees that the mapping is added before the adding
+ // forwarding rules. That is because there are different state machines in both
+ // classes. It is hard to guarantee the link property update order between multiple
+ // state machines.
+ mBpfCoordinator.addUpstreamNameToLookupTable(upstreamIfindex, upstreamIface);
}
// If v6only is null, we pass in null to setRaParams(), which handles
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
new file mode 100644
index 0000000..0092eb7
--- /dev/null
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -0,0 +1,280 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.networkstack.tethering;
+
+import static android.net.NetworkStats.DEFAULT_NETWORK_NO;
+import static android.net.NetworkStats.METERED_NO;
+import static android.net.NetworkStats.ROAMING_NO;
+import static android.net.NetworkStats.SET_DEFAULT;
+import static android.net.NetworkStats.TAG_NONE;
+import static android.net.NetworkStats.UID_ALL;
+import static android.net.NetworkStats.UID_TETHERING;
+
+import android.app.usage.NetworkStatsManager;
+import android.net.INetd;
+import android.net.NetworkStats;
+import android.net.NetworkStats.Entry;
+import android.net.TetherStatsParcel;
+import android.net.netstats.provider.NetworkStatsProvider;
+import android.net.util.SharedLog;
+import android.net.util.TetheringUtils.ForwardedStats;
+import android.os.Handler;
+import android.os.RemoteException;
+import android.os.ServiceSpecificException;
+import android.util.Log;
+import android.util.SparseArray;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+/**
+ * This coordinator is responsible for providing BPF offload relevant functionality.
+ * - Get tethering stats.
+ *
+ * @hide
+ */
+public class BpfCoordinator {
+ private static final String TAG = BpfCoordinator.class.getSimpleName();
+ // TODO: Make it customizable.
+ private static final int DEFAULT_PERFORM_POLL_INTERVAL_MS = 5000;
+
+ private enum StatsType {
+ STATS_PER_IFACE,
+ STATS_PER_UID,
+ }
+
+ @NonNull
+ private final Handler mHandler;
+ @NonNull
+ private final INetd mNetd;
+ @NonNull
+ private final SharedLog mLog;
+ @NonNull
+ private final Dependencies mDeps;
+ @Nullable
+ private final BpfTetherStatsProvider mStatsProvider;
+ private boolean mStarted = false;
+
+ // Maps upstream interface index to offloaded traffic statistics.
+ // Always contains the latest total bytes/packets, since each upstream was started, received
+ // from the BPF maps for each interface.
+ private SparseArray<ForwardedStats> mStats = new SparseArray<>();
+
+ // Maps upstream interface index to interface names.
+ // Store all interface name since boot. Used for lookup what interface name it is from the
+ // tether stats got from netd because netd reports interface index to present an interface.
+ // TODO: Remove the unused interface name.
+ private SparseArray<String> mInterfaceNames = new SparseArray<>();
+
+ // Runnable that used by scheduling next polling of stats.
+ private final Runnable mScheduledPollingTask = () -> {
+ updateForwardedStatsFromNetd();
+ maybeSchedulePollingStats();
+ };
+
+ static class Dependencies {
+ int getPerformPollInterval() {
+ // TODO: Consider make this configurable.
+ return DEFAULT_PERFORM_POLL_INTERVAL_MS;
+ }
+ }
+
+ BpfCoordinator(@NonNull Handler handler, @NonNull INetd netd,
+ @NonNull NetworkStatsManager nsm, @NonNull SharedLog log, @NonNull Dependencies deps) {
+ mHandler = handler;
+ mNetd = netd;
+ mLog = log.forSubComponent(TAG);
+ BpfTetherStatsProvider provider = new BpfTetherStatsProvider();
+ try {
+ nsm.registerNetworkStatsProvider(getClass().getSimpleName(), provider);
+ } catch (RuntimeException e) {
+ // TODO: Perhaps not allow to use BPF offload because the reregistration failure
+ // implied that no data limit could be applies on a metered upstream if any.
+ Log.wtf(TAG, "Cannot register offload stats provider: " + e);
+ provider = null;
+ }
+ mStatsProvider = provider;
+ mDeps = deps;
+ }
+
+ /**
+ * Start BPF tethering offload stats polling when the first upstream is started.
+ * Note that this can be only called on handler thread.
+ * TODO: Perhaps check BPF support before starting.
+ * TODO: Start the stats polling only if there is any client on the downstream.
+ */
+ public void start() {
+ if (mStarted) return;
+
+ mStarted = true;
+ maybeSchedulePollingStats();
+
+ mLog.i("BPF tethering coordinator started");
+ }
+
+ /**
+ * Stop BPF tethering offload stats polling and cleanup upstream parameters.
+ * Note that this can be only called on handler thread.
+ */
+ public void stop() {
+ if (!mStarted) return;
+
+ // Stop scheduled polling tasks and poll the latest stats from BPF maps.
+ if (mHandler.hasCallbacks(mScheduledPollingTask)) {
+ mHandler.removeCallbacks(mScheduledPollingTask);
+ }
+ updateForwardedStatsFromNetd();
+
+ mStarted = false;
+
+ mLog.i("BPF tethering coordinator stopped");
+ }
+
+ /**
+ * Add upstream name to lookup table. The lookup table is used for tether stats interface name
+ * lookup because the netd only reports interface index in BPF tether stats but the service
+ * expects the interface name in NetworkStats object.
+ * Note that this can be only called on handler thread.
+ */
+ public void addUpstreamNameToLookupTable(int upstreamIfindex, String upstreamIface) {
+ if (upstreamIfindex == 0) return;
+
+ // The same interface index to name mapping may be added by different IpServer objects or
+ // re-added by reconnection on the same upstream interface. Ignore the duplicate one.
+ final String iface = mInterfaceNames.get(upstreamIfindex);
+ if (iface == null) {
+ mInterfaceNames.put(upstreamIfindex, upstreamIface);
+ } else if (iface != upstreamIface) {
+ Log.wtf(TAG, "The upstream interface name " + upstreamIface
+ + " is different from the existing interface name "
+ + iface + " for index " + upstreamIfindex);
+ }
+ }
+
+ /**
+ * A BPF tethering stats provider to provide network statistics to the system.
+ * Note that this class's data may only be accessed on the handler thread.
+ */
+ private class BpfTetherStatsProvider extends NetworkStatsProvider {
+ // The offloaded traffic statistics per interface that has not been reported since the
+ // last call to pushTetherStats. Only the interfaces that were ever tethering upstreams
+ // and has pending tether stats delta are included in this NetworkStats object.
+ private NetworkStats mIfaceStats = new NetworkStats(0L, 0);
+
+ // The same stats as above, but counts network stats per uid.
+ private NetworkStats mUidStats = new NetworkStats(0L, 0);
+
+ @Override
+ public void onRequestStatsUpdate(int token) {
+ mHandler.post(() -> pushTetherStats());
+ }
+
+ @Override
+ public void onSetAlert(long quotaBytes) {
+ // no-op
+ }
+
+ @Override
+ public void onSetLimit(@NonNull String iface, long quotaBytes) {
+ // no-op
+ }
+
+ private void pushTetherStats() {
+ try {
+ // The token is not used for now. See b/153606961.
+ notifyStatsUpdated(0 /* token */, mIfaceStats, mUidStats);
+
+ // Clear the accumulated tether stats delta after reported. Note that create a new
+ // empty object because NetworkStats#clear is @hide.
+ mIfaceStats = new NetworkStats(0L, 0);
+ mUidStats = new NetworkStats(0L, 0);
+ } catch (RuntimeException e) {
+ mLog.e("Cannot report network stats: ", e);
+ }
+ }
+
+ private void accumulateDiff(@NonNull NetworkStats ifaceDiff,
+ @NonNull NetworkStats uidDiff) {
+ mIfaceStats = mIfaceStats.add(ifaceDiff);
+ mUidStats = mUidStats.add(uidDiff);
+ }
+ }
+
+ @NonNull
+ private NetworkStats buildNetworkStats(@NonNull StatsType type, int ifIndex,
+ @NonNull ForwardedStats diff) {
+ NetworkStats stats = new NetworkStats(0L, 0);
+ final String iface = mInterfaceNames.get(ifIndex);
+ if (iface == null) {
+ // TODO: Use Log.wtf once the coordinator owns full control of tether stats from netd.
+ // For now, netd may add the empty stats for the upstream which is not monitored by
+ // the coordinator. Silently ignore it.
+ return stats;
+ }
+ final int uid = (type == StatsType.STATS_PER_UID) ? UID_TETHERING : UID_ALL;
+ // Note that the argument 'metered', 'roaming' and 'defaultNetwork' are not recorded for
+ // network stats snapshot. See NetworkStatsRecorder#recordSnapshotLocked.
+ return stats.addEntry(new Entry(iface, uid, SET_DEFAULT, TAG_NONE, METERED_NO,
+ ROAMING_NO, DEFAULT_NETWORK_NO, diff.rxBytes, diff.rxPackets,
+ diff.txBytes, diff.txPackets, 0L /* operations */));
+ }
+
+ private void updateForwardedStatsFromNetd() {
+ final TetherStatsParcel[] tetherStatsList;
+ try {
+ // The reported tether stats are total data usage for all currently-active upstream
+ // interfaces since tethering start.
+ tetherStatsList = mNetd.tetherOffloadGetStats();
+ } catch (RemoteException | ServiceSpecificException e) {
+ mLog.e("Problem fetching tethering stats: ", e);
+ return;
+ }
+
+ for (TetherStatsParcel tetherStats : tetherStatsList) {
+ final Integer ifIndex = tetherStats.ifIndex;
+ final ForwardedStats curr = new ForwardedStats(tetherStats);
+ final ForwardedStats base = mStats.get(ifIndex);
+ final ForwardedStats diff = (base != null) ? curr.subtract(base) : curr;
+
+ // Update the local cache for counting tether stats delta.
+ mStats.put(ifIndex, curr);
+
+ // Update the accumulated tether stats delta to the stats provider for the service
+ // querying.
+ if (mStatsProvider != null) {
+ try {
+ mStatsProvider.accumulateDiff(
+ buildNetworkStats(StatsType.STATS_PER_IFACE, ifIndex, diff),
+ buildNetworkStats(StatsType.STATS_PER_UID, ifIndex, diff));
+ } catch (ArrayIndexOutOfBoundsException e) {
+ Log.wtf("Fail to update the accumulated stats delta for interface index "
+ + ifIndex + " : ", e);
+ }
+ }
+ }
+ }
+
+ private void maybeSchedulePollingStats() {
+ if (!mStarted) return;
+
+ if (mHandler.hasCallbacks(mScheduledPollingTask)) {
+ mHandler.removeCallbacks(mScheduledPollingTask);
+ }
+
+ mHandler.postDelayed(mScheduledPollingTask, mDeps.getPerformPollInterval());
+ }
+}
diff --git a/Tethering/src/com/android/networkstack/tethering/Tethering.java b/Tethering/src/com/android/networkstack/tethering/Tethering.java
index 69eec8d..cfe9fea 100644
--- a/Tethering/src/com/android/networkstack/tethering/Tethering.java
+++ b/Tethering/src/com/android/networkstack/tethering/Tethering.java
@@ -232,6 +232,7 @@
private final TetheringThreadExecutor mExecutor;
private final TetheringNotificationUpdater mNotificationUpdater;
private final UserManager mUserManager;
+ private final BpfCoordinator mBpfCoordinator;
private final PrivateAddressCoordinator mPrivateAddressCoordinator;
private int mActiveDataSubId = INVALID_SUBSCRIPTION_ID;
// All the usage of mTetheringEventCallback should run in the same thread.
@@ -284,6 +285,8 @@
mUpstreamNetworkMonitor = mDeps.getUpstreamNetworkMonitor(mContext, mTetherMasterSM, mLog,
TetherMasterSM.EVENT_UPSTREAM_CALLBACK);
mForwardedDownstreams = new LinkedHashSet<>();
+ mBpfCoordinator = mDeps.getBpfCoordinator(
+ mHandler, mNetd, mLog, new BpfCoordinator.Dependencies());
IntentFilter filter = new IntentFilter();
filter.addAction(ACTION_CARRIER_CONFIG_CHANGED);
@@ -1704,6 +1707,9 @@
chooseUpstreamType(true);
mTryCell = false;
}
+
+ // TODO: Check the upstream interface if it is managed by BPF offload.
+ mBpfCoordinator.start();
}
@Override
@@ -1716,6 +1722,7 @@
mTetherUpstream = null;
reportUpstreamChanged(null);
}
+ mBpfCoordinator.stop();
}
private boolean updateUpstreamWanted() {
@@ -2341,7 +2348,7 @@
mLog.log("adding TetheringInterfaceStateMachine for: " + iface);
final TetherState tetherState = new TetherState(
- new IpServer(iface, mLooper, interfaceType, mLog, mNetd,
+ new IpServer(iface, mLooper, interfaceType, mLog, mNetd, mBpfCoordinator,
makeControlCallback(), mConfig.enableLegacyDhcpServer,
mConfig.enableBpfOffload, mPrivateAddressCoordinator,
mDeps.getIpServerDependencies()));
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java b/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java
index ce546c7..d637c86 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringDependencies.java
@@ -41,6 +41,17 @@
*/
public abstract class TetheringDependencies {
/**
+ * Get a reference to the BpfCoordinator to be used by tethering.
+ */
+ public @NonNull BpfCoordinator getBpfCoordinator(
+ @NonNull Handler handler, @NonNull INetd netd, @NonNull SharedLog log,
+ @NonNull BpfCoordinator.Dependencies deps) {
+ final NetworkStatsManager statsManager =
+ (NetworkStatsManager) getContext().getSystemService(Context.NETWORK_STATS_SERVICE);
+ return new BpfCoordinator(handler, netd, statsManager, log, deps);
+ }
+
+ /**
* Get a reference to the offload hardware interface to be used by tethering.
*/
public OffloadHardwareInterface getOffloadHardwareInterface(Handler h, SharedLog log) {
diff --git a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
index 0cda29a..433aacf 100644
--- a/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
+++ b/Tethering/tests/unit/src/android/net/ip/IpServerTest.java
@@ -87,6 +87,7 @@
import androidx.test.filters.SmallTest;
import androidx.test.runner.AndroidJUnit4;
+import com.android.networkstack.tethering.BpfCoordinator;
import com.android.networkstack.tethering.PrivateAddressCoordinator;
import org.junit.Before;
@@ -126,6 +127,7 @@
private final IpPrefix mBluetoothPrefix = new IpPrefix("192.168.44.0/24");
@Mock private INetd mNetd;
+ @Mock private BpfCoordinator mBpfCoordinator;
@Mock private IpServer.Callback mCallback;
@Mock private SharedLog mSharedLog;
@Mock private IDhcpServer mDhcpServer;
@@ -179,7 +181,7 @@
neighborCaptor.capture());
mIpServer = new IpServer(
- IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog, mNetd,
+ IFACE_NAME, mLooper.getLooper(), interfaceType, mSharedLog, mNetd, mBpfCoordinator,
mCallback, usingLegacyDhcp, usingBpfOffload, mAddressCoordinator, mDependencies);
mIpServer.start();
mNeighborEventConsumer = neighborCaptor.getValue();
@@ -222,8 +224,8 @@
when(mDependencies.getIpNeighborMonitor(any(), any(), any()))
.thenReturn(mIpNeighborMonitor);
mIpServer = new IpServer(IFACE_NAME, mLooper.getLooper(), TETHERING_BLUETOOTH, mSharedLog,
- mNetd, mCallback, false /* usingLegacyDhcp */, DEFAULT_USING_BPF_OFFLOAD,
- mAddressCoordinator, mDependencies);
+ mNetd, mBpfCoordinator, mCallback, false /* usingLegacyDhcp */,
+ DEFAULT_USING_BPF_OFFLOAD, mAddressCoordinator, mDependencies);
mIpServer.start();
mLooper.dispatchAll();
verify(mCallback).updateInterfaceState(
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
index bb65b18..8146a58 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/TetheringTest.java
@@ -203,6 +203,7 @@
@Mock private ConnectivityManager mCm;
@Mock private EthernetManager mEm;
@Mock private TetheringNotificationUpdater mNotificationUpdater;
+ @Mock private BpfCoordinator mBpfCoordinator;
private final MockIpServerDependencies mIpServerDependencies =
spy(new MockIpServerDependencies());
@@ -337,6 +338,12 @@
}
@Override
+ public BpfCoordinator getBpfCoordinator(Handler handler, INetd netd,
+ SharedLog log, BpfCoordinator.Dependencies deps) {
+ return mBpfCoordinator;
+ }
+
+ @Override
public OffloadHardwareInterface getOffloadHardwareInterface(Handler h, SharedLog log) {
return mOffloadHardwareInterface;
}