Merge history of ConnectivityT

Renamed files/directories:
ConnectivityT/service/Android.bp --> service-t/Sources.bp
ConnectivityT/framework-t/Android.bp --> framework-t/Sources.bp
ConnectivityT/framework-t/aidl-export --> framework/aidl-export
ConnectivityT/service --> service-t
ConnectivityT/framework-t --> framework-t
ConnectivityT/tests --> tests
ConnectivityT/OWNERS --> (removed)

BUG: 222234190
TEST: TH
Ignore-AOSP-First: Move with history done per-branch
Merged-In: I81893df9f327abb84f1561b2b33027a2d23a4d65
Merged-In: I67c703e3f7aa9d5787f032a79ed62e45412baf4f
Change-Id: I27a91f1a94f9d807f92762436f533c4b0d0114d5

service-t/src/com/android/server/INativeDaemonConnectorCallbacks.java

@@ -0,0 +1,25 @@
+
+/*
+ * Copyright (C) 2007 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.server;
+
+interface INativeDaemonConnectorCallbacks {
+
+    void onDaemonConnected();
+    boolean onCheckHoldWakeLock(int code);
+    boolean onEvent(int code, String raw, String[] cooked);
+}

service-t/src/com/android/server/NativeDaemonConnector.java

@@ -0,0 +1,704 @@
+/*
+ * Copyright (C) 2007 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.server;
+
+import android.net.LocalSocket;
+import android.net.LocalSocketAddress;
+import android.os.Build;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Looper;
+import android.os.Message;
+import android.os.PowerManager;
+import android.os.SystemClock;
+import android.util.LocalLog;
+import android.util.Log;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.Objects;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Generic connector class for interfacing with a native daemon which uses the
+ * {@code libsysutils} FrameworkListener protocol.
+ */
+final class NativeDaemonConnector implements Runnable, Handler.Callback {
+    private final static boolean VDBG = false;
+
+    private final String TAG;
+
+    private String mSocket;
+    private OutputStream mOutputStream;
+    private LocalLog mLocalLog;
+
+    private volatile boolean mDebug = false;
+    private volatile Object mWarnIfHeld;
+
+    private final ResponseQueue mResponseQueue;
+
+    private final PowerManager.WakeLock mWakeLock;
+
+    private final Looper mLooper;
+
+    private INativeDaemonConnectorCallbacks mCallbacks;
+    private Handler mCallbackHandler;
+
+    private AtomicInteger mSequenceNumber;
+
+    private static final long DEFAULT_TIMEOUT = 1 * 60 * 1000; /* 1 minute */
+    private static final long WARN_EXECUTE_DELAY_MS = 500; /* .5 sec */
+
+    /** Lock held whenever communicating with native daemon. */
+    private final Object mDaemonLock = new Object();
+
+    private final int BUFFER_SIZE = 4096;
+
+    NativeDaemonConnector(INativeDaemonConnectorCallbacks callbacks, String socket,
+            int responseQueueSize, String logTag, int maxLogSize, PowerManager.WakeLock wl) {
+        mCallbacks = callbacks;
+        mSocket = socket;
+        mResponseQueue = new ResponseQueue(responseQueueSize);
+        mWakeLock = wl;
+        if (mWakeLock != null) {
+            mWakeLock.setReferenceCounted(true);
+        }
+        mSequenceNumber = new AtomicInteger(0);
+        TAG = logTag != null ? logTag : "NativeDaemonConnector";
+        mLocalLog = new LocalLog(maxLogSize);
+        final HandlerThread thread = new HandlerThread(TAG);
+        thread.start();
+        mLooper = thread.getLooper();
+    }
+
+    /**
+     * Enable Set debugging mode, which causes messages to also be written to both
+     * {@link Log} in addition to internal log.
+     */
+    public void setDebug(boolean debug) {
+        mDebug = debug;
+    }
+
+    /**
+     * Like SystemClock.uptimeMillis, except truncated to an int so it will fit in a message arg.
+     * Inaccurate across 49.7 days of uptime, but only used for debugging.
+     */
+    private int uptimeMillisInt() {
+        return (int) SystemClock.uptimeMillis() & Integer.MAX_VALUE;
+    }
+
+    /**
+     * Yell loudly if someone tries making future {@link #execute(Command)}
+     * calls while holding a lock on the given object.
+     */
+    public void setWarnIfHeld(Object warnIfHeld) {
+        if (mWarnIfHeld != null) {
+            throw new IllegalStateException("warnIfHeld is already set.");
+        }
+        mWarnIfHeld = Objects.requireNonNull(warnIfHeld);
+    }
+
+    @Override
+    public void run() {
+        mCallbackHandler = new Handler(mLooper, this);
+
+        while (true) {
+            try {
+                listenToSocket();
+            } catch (Exception e) {
+                loge("Error in NativeDaemonConnector: " + e);
+                SystemClock.sleep(5000);
+            }
+        }
+    }
+
+    @Override
+    public boolean handleMessage(Message msg) {
+        final String event = (String) msg.obj;
+        final int start = uptimeMillisInt();
+        final int sent = msg.arg1;
+        try {
+            if (!mCallbacks.onEvent(msg.what, event, NativeDaemonEvent.unescapeArgs(event))) {
+                log(String.format("Unhandled event '%s'", event));
+            }
+        } catch (Exception e) {
+            loge("Error handling '" + event + "': " + e);
+        } finally {
+            if (mCallbacks.onCheckHoldWakeLock(msg.what) && mWakeLock != null) {
+                mWakeLock.release();
+            }
+            final int end = uptimeMillisInt();
+            if (start > sent && start - sent > WARN_EXECUTE_DELAY_MS) {
+                loge(String.format("NDC event {%s} processed too late: %dms", event, start - sent));
+            }
+            if (end > start && end - start > WARN_EXECUTE_DELAY_MS) {
+                loge(String.format("NDC event {%s} took too long: %dms", event, end - start));
+            }
+        }
+        return true;
+    }
+
+    private LocalSocketAddress determineSocketAddress() {
+        // If we're testing, set up a socket in a namespace that's accessible to test code.
+        // In order to ensure that unprivileged apps aren't able to impersonate native daemons on
+        // production devices, even if said native daemons ill-advisedly pick a socket name that
+        // starts with __test__, only allow this on debug builds.
+        if (mSocket.startsWith("__test__") && Build.isDebuggable()) {
+            return new LocalSocketAddress(mSocket);
+        } else {
+            return new LocalSocketAddress(mSocket, LocalSocketAddress.Namespace.RESERVED);
+        }
+    }
+
+    private void listenToSocket() throws IOException {
+        LocalSocket socket = null;
+
+        try {
+            socket = new LocalSocket();
+            LocalSocketAddress address = determineSocketAddress();
+
+            socket.connect(address);
+
+            InputStream inputStream = socket.getInputStream();
+            synchronized (mDaemonLock) {
+                mOutputStream = socket.getOutputStream();
+            }
+
+            mCallbacks.onDaemonConnected();
+
+            FileDescriptor[] fdList = null;
+            byte[] buffer = new byte[BUFFER_SIZE];
+            int start = 0;
+
+            while (true) {
+                int count = inputStream.read(buffer, start, BUFFER_SIZE - start);
+                if (count < 0) {
+                    loge("got " + count + " reading with start = " + start);
+                    break;
+                }
+                fdList = socket.getAncillaryFileDescriptors();
+
+                // Add our starting point to the count and reset the start.
+                count += start;
+                start = 0;
+
+                for (int i = 0; i < count; i++) {
+                    if (buffer[i] == 0) {
+                        // Note - do not log this raw message since it may contain
+                        // sensitive data
+                        final String rawEvent = new String(
+                                buffer, start, i - start, StandardCharsets.UTF_8);
+
+                        boolean releaseWl = false;
+                        try {
+                            final NativeDaemonEvent event =
+                                    NativeDaemonEvent.parseRawEvent(rawEvent, fdList);
+
+                            log("RCV <- {" + event + "}");
+
+                            if (event.isClassUnsolicited()) {
+                                // TODO: migrate to sending NativeDaemonEvent instances
+                                if (mCallbacks.onCheckHoldWakeLock(event.getCode())
+                                        && mWakeLock != null) {
+                                    mWakeLock.acquire();
+                                    releaseWl = true;
+                                }
+                                Message msg = mCallbackHandler.obtainMessage(
+                                        event.getCode(), uptimeMillisInt(), 0, event.getRawEvent());
+                                if (mCallbackHandler.sendMessage(msg)) {
+                                    releaseWl = false;
+                                }
+                            } else {
+                                mResponseQueue.add(event.getCmdNumber(), event);
+                            }
+                        } catch (IllegalArgumentException e) {
+                            log("Problem parsing message " + e);
+                        } finally {
+                            if (releaseWl) {
+                                mWakeLock.release();
+                            }
+                        }
+
+                        start = i + 1;
+                    }
+                }
+
+                if (start == 0) {
+                    log("RCV incomplete");
+                }
+
+                // We should end at the amount we read. If not, compact then
+                // buffer and read again.
+                if (start != count) {
+                    final int remaining = BUFFER_SIZE - start;
+                    System.arraycopy(buffer, start, buffer, 0, remaining);
+                    start = remaining;
+                } else {
+                    start = 0;
+                }
+            }
+        } catch (IOException ex) {
+            loge("Communications error: " + ex);
+            throw ex;
+        } finally {
+            synchronized (mDaemonLock) {
+                if (mOutputStream != null) {
+                    try {
+                        loge("closing stream for " + mSocket);
+                        mOutputStream.close();
+                    } catch (IOException e) {
+                        loge("Failed closing output stream: " + e);
+                    }
+                    mOutputStream = null;
+                }
+            }
+
+            try {
+                if (socket != null) {
+                    socket.close();
+                }
+            } catch (IOException ex) {
+                loge("Failed closing socket: " + ex);
+            }
+        }
+    }
+
+    /**
+     * Wrapper around argument that indicates it's sensitive and shouldn't be
+     * logged.
+     */
+    public static class SensitiveArg {
+        private final Object mArg;
+
+        public SensitiveArg(Object arg) {
+            mArg = arg;
+        }
+
+        @Override
+        public String toString() {
+            return String.valueOf(mArg);
+        }
+    }
+
+    /**
+     * Make command for daemon, escaping arguments as needed.
+     */
+    @VisibleForTesting
+    static void makeCommand(StringBuilder rawBuilder, StringBuilder logBuilder, int sequenceNumber,
+            String cmd, Object... args) {
+        if (cmd.indexOf('\0') >= 0) {
+            throw new IllegalArgumentException("Unexpected command: " + cmd);
+        }
+        if (cmd.indexOf(' ') >= 0) {
+            throw new IllegalArgumentException("Arguments must be separate from command");
+        }
+
+        rawBuilder.append(sequenceNumber).append(' ').append(cmd);
+        logBuilder.append(sequenceNumber).append(' ').append(cmd);
+        for (Object arg : args) {
+            final String argString = String.valueOf(arg);
+            if (argString.indexOf('\0') >= 0) {
+                throw new IllegalArgumentException("Unexpected argument: " + arg);
+            }
+
+            rawBuilder.append(' ');
+            logBuilder.append(' ');
+
+            appendEscaped(rawBuilder, argString);
+            if (arg instanceof SensitiveArg) {
+                logBuilder.append("[scrubbed]");
+            } else {
+                appendEscaped(logBuilder, argString);
+            }
+        }
+
+        rawBuilder.append('\0');
+    }
+
+    /**
+     * Method that waits until all asychronous notifications sent by the native daemon have
+     * been processed. This method must not be called on the notification thread or an
+     * exception will be thrown.
+     */
+    public void waitForCallbacks() {
+        if (Thread.currentThread() == mLooper.getThread()) {
+            throw new IllegalStateException("Must not call this method on callback thread");
+        }
+
+        final CountDownLatch latch = new CountDownLatch(1);
+        mCallbackHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                latch.countDown();
+            }
+        });
+        try {
+            latch.await();
+        } catch (InterruptedException e) {
+            Log.wtf(TAG, "Interrupted while waiting for unsolicited response handling", e);
+        }
+    }
+
+    /**
+     * Issue the given command to the native daemon and return a single expected
+     * response.
+     *
+     * @throws NativeDaemonConnectorException when problem communicating with
+     *             native daemon, or if the response matches
+     *             {@link NativeDaemonEvent#isClassClientError()} or
+     *             {@link NativeDaemonEvent#isClassServerError()}.
+     */
+    public NativeDaemonEvent execute(Command cmd) throws NativeDaemonConnectorException {
+        return execute(cmd.mCmd, cmd.mArguments.toArray());
+    }
+
+    /**
+     * Issue the given command to the native daemon and return a single expected
+     * response. Any arguments must be separated from base command so they can
+     * be properly escaped.
+     *
+     * @throws NativeDaemonConnectorException when problem communicating with
+     *             native daemon, or if the response matches
+     *             {@link NativeDaemonEvent#isClassClientError()} or
+     *             {@link NativeDaemonEvent#isClassServerError()}.
+     */
+    public NativeDaemonEvent execute(String cmd, Object... args)
+            throws NativeDaemonConnectorException {
+        return execute(DEFAULT_TIMEOUT, cmd, args);
+    }
+
+    public NativeDaemonEvent execute(long timeoutMs, String cmd, Object... args)
+            throws NativeDaemonConnectorException {
+        final NativeDaemonEvent[] events = executeForList(timeoutMs, cmd, args);
+        if (events.length != 1) {
+            throw new NativeDaemonConnectorException(
+                    "Expected exactly one response, but received " + events.length);
+        }
+        return events[0];
+    }
+
+    /**
+     * Issue the given command to the native daemon and return any
+     * {@link NativeDaemonEvent#isClassContinue()} responses, including the
+     * final terminal response.
+     *
+     * @throws NativeDaemonConnectorException when problem communicating with
+     *             native daemon, or if the response matches
+     *             {@link NativeDaemonEvent#isClassClientError()} or
+     *             {@link NativeDaemonEvent#isClassServerError()}.
+     */
+    public NativeDaemonEvent[] executeForList(Command cmd) throws NativeDaemonConnectorException {
+        return executeForList(cmd.mCmd, cmd.mArguments.toArray());
+    }
+
+    /**
+     * Issue the given command to the native daemon and return any
+     * {@link NativeDaemonEvent#isClassContinue()} responses, including the
+     * final terminal response. Any arguments must be separated from base
+     * command so they can be properly escaped.
+     *
+     * @throws NativeDaemonConnectorException when problem communicating with
+     *             native daemon, or if the response matches
+     *             {@link NativeDaemonEvent#isClassClientError()} or
+     *             {@link NativeDaemonEvent#isClassServerError()}.
+     */
+    public NativeDaemonEvent[] executeForList(String cmd, Object... args)
+            throws NativeDaemonConnectorException {
+        return executeForList(DEFAULT_TIMEOUT, cmd, args);
+    }
+
+    /**
+     * Issue the given command to the native daemon and return any {@linke
+     * NativeDaemonEvent@isClassContinue()} responses, including the final
+     * terminal response. Note that the timeout does not count time in deep
+     * sleep. Any arguments must be separated from base command so they can be
+     * properly escaped.
+     *
+     * @throws NativeDaemonConnectorException when problem communicating with
+     *             native daemon, or if the response matches
+     *             {@link NativeDaemonEvent#isClassClientError()} or
+     *             {@link NativeDaemonEvent#isClassServerError()}.
+     */
+    public NativeDaemonEvent[] executeForList(long timeoutMs, String cmd, Object... args)
+            throws NativeDaemonConnectorException {
+        if (mWarnIfHeld != null && Thread.holdsLock(mWarnIfHeld)) {
+            Log.wtf(TAG, "Calling thread " + Thread.currentThread().getName() + " is holding 0x"
+                    + Integer.toHexString(System.identityHashCode(mWarnIfHeld)), new Throwable());
+        }
+
+        final long startTime = SystemClock.elapsedRealtime();
+
+        final ArrayList<NativeDaemonEvent> events = new ArrayList<>();
+
+        final StringBuilder rawBuilder = new StringBuilder();
+        final StringBuilder logBuilder = new StringBuilder();
+        final int sequenceNumber = mSequenceNumber.incrementAndGet();
+
+        makeCommand(rawBuilder, logBuilder, sequenceNumber, cmd, args);
+
+        final String rawCmd = rawBuilder.toString();
+        final String logCmd = logBuilder.toString();
+
+        log("SND -> {" + logCmd + "}");
+
+        synchronized (mDaemonLock) {
+            if (mOutputStream == null) {
+                throw new NativeDaemonConnectorException("missing output stream");
+            } else {
+                try {
+                    mOutputStream.write(rawCmd.getBytes(StandardCharsets.UTF_8));
+                } catch (IOException e) {
+                    throw new NativeDaemonConnectorException("problem sending command", e);
+                }
+            }
+        }
+
+        NativeDaemonEvent event = null;
+        do {
+            event = mResponseQueue.remove(sequenceNumber, timeoutMs, logCmd);
+            if (event == null) {
+                loge("timed-out waiting for response to " + logCmd);
+                throw new NativeDaemonTimeoutException(logCmd, event);
+            }
+            if (VDBG) log("RMV <- {" + event + "}");
+            events.add(event);
+        } while (event.isClassContinue());
+
+        final long endTime = SystemClock.elapsedRealtime();
+        if (endTime - startTime > WARN_EXECUTE_DELAY_MS) {
+            loge("NDC Command {" + logCmd + "} took too long (" + (endTime - startTime) + "ms)");
+        }
+
+        if (event.isClassClientError()) {
+            throw new NativeDaemonArgumentException(logCmd, event);
+        }
+        if (event.isClassServerError()) {
+            throw new NativeDaemonFailureException(logCmd, event);
+        }
+
+        return events.toArray(new NativeDaemonEvent[events.size()]);
+    }
+
+    /**
+     * Append the given argument to {@link StringBuilder}, escaping as needed,
+     * and surrounding with quotes when it contains spaces.
+     */
+    @VisibleForTesting
+    static void appendEscaped(StringBuilder builder, String arg) {
+        final boolean hasSpaces = arg.indexOf(' ') >= 0;
+        if (hasSpaces) {
+            builder.append('"');
+        }
+
+        final int length = arg.length();
+        for (int i = 0; i < length; i++) {
+            final char c = arg.charAt(i);
+
+            if (c == '"') {
+                builder.append("\\\"");
+            } else if (c == '\\') {
+                builder.append("\\\\");
+            } else {
+                builder.append(c);
+            }
+        }
+
+        if (hasSpaces) {
+            builder.append('"');
+        }
+    }
+
+    private static class NativeDaemonArgumentException extends NativeDaemonConnectorException {
+        public NativeDaemonArgumentException(String command, NativeDaemonEvent event) {
+            super(command, event);
+        }
+
+        @Override
+        public IllegalArgumentException rethrowAsParcelableException() {
+            throw new IllegalArgumentException(getMessage(), this);
+        }
+    }
+
+    private static class NativeDaemonFailureException extends NativeDaemonConnectorException {
+        public NativeDaemonFailureException(String command, NativeDaemonEvent event) {
+            super(command, event);
+        }
+    }
+
+    /**
+     * Command builder that handles argument list building. Any arguments must
+     * be separated from base command so they can be properly escaped.
+     */
+    public static class Command {
+        private String mCmd;
+        private ArrayList<Object> mArguments = new ArrayList<>();
+
+        public Command(String cmd, Object... args) {
+            mCmd = cmd;
+            for (Object arg : args) {
+                appendArg(arg);
+            }
+        }
+
+        public Command appendArg(Object arg) {
+            mArguments.add(arg);
+            return this;
+        }
+    }
+
+    public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
+        mLocalLog.dump(fd, pw, args);
+        pw.println();
+        mResponseQueue.dump(fd, pw, args);
+    }
+
+    private void log(String logstring) {
+        if (mDebug) Log.d(TAG, logstring);
+        mLocalLog.log(logstring);
+    }
+
+    private void loge(String logstring) {
+        Log.e(TAG, logstring);
+        mLocalLog.log(logstring);
+    }
+
+    private static class ResponseQueue {
+
+        private static class PendingCmd {
+            public final int cmdNum;
+            public final String logCmd;
+
+            public BlockingQueue<NativeDaemonEvent> responses =
+                    new ArrayBlockingQueue<NativeDaemonEvent>(10);
+
+            // The availableResponseCount member is used to track when we can remove this
+            // instance from the ResponseQueue.
+            // This is used under the protection of a sync of the mPendingCmds object.
+            // A positive value means we've had more writers retreive this object while
+            // a negative value means we've had more readers.  When we've had an equal number
+            // (it goes to zero) we can remove this object from the mPendingCmds list.
+            // Note that we may have more responses for this command (and more readers
+            // coming), but that would result in a new PendingCmd instance being created
+            // and added with the same cmdNum.
+            // Also note that when this goes to zero it just means a parity of readers and
+            // writers have retrieved this object - not that they are done using it.  The
+            // responses queue may well have more responses yet to be read or may get more
+            // responses added to it.  But all those readers/writers have retreived and
+            // hold references to this instance already so it can be removed from
+            // mPendingCmds queue.
+            public int availableResponseCount;
+
+            public PendingCmd(int cmdNum, String logCmd) {
+                this.cmdNum = cmdNum;
+                this.logCmd = logCmd;
+            }
+        }
+
+        private final LinkedList<PendingCmd> mPendingCmds;
+        private int mMaxCount;
+
+        ResponseQueue(int maxCount) {
+            mPendingCmds = new LinkedList<PendingCmd>();
+            mMaxCount = maxCount;
+        }
+
+        public void add(int cmdNum, NativeDaemonEvent response) {
+            PendingCmd found = null;
+            synchronized (mPendingCmds) {
+                for (PendingCmd pendingCmd : mPendingCmds) {
+                    if (pendingCmd.cmdNum == cmdNum) {
+                        found = pendingCmd;
+                        break;
+                    }
+                }
+                if (found == null) {
+                    // didn't find it - make sure our queue isn't too big before adding
+                    while (mPendingCmds.size() >= mMaxCount) {
+                        Log.e("NativeDaemonConnector.ResponseQueue",
+                                "more buffered than allowed: " + mPendingCmds.size() +
+                                " >= " + mMaxCount);
+                        // let any waiter timeout waiting for this
+                        PendingCmd pendingCmd = mPendingCmds.remove();
+                        Log.e("NativeDaemonConnector.ResponseQueue",
+                                "Removing request: " + pendingCmd.logCmd + " (" +
+                                pendingCmd.cmdNum + ")");
+                    }
+                    found = new PendingCmd(cmdNum, null);
+                    mPendingCmds.add(found);
+                }
+                found.availableResponseCount++;
+                // if a matching remove call has already retrieved this we can remove this
+                // instance from our list
+                if (found.availableResponseCount == 0) mPendingCmds.remove(found);
+            }
+            try {
+                found.responses.put(response);
+            } catch (InterruptedException e) { }
+        }
+
+        // note that the timeout does not count time in deep sleep.  If you don't want
+        // the device to sleep, hold a wakelock
+        public NativeDaemonEvent remove(int cmdNum, long timeoutMs, String logCmd) {
+            PendingCmd found = null;
+            synchronized (mPendingCmds) {
+                for (PendingCmd pendingCmd : mPendingCmds) {
+                    if (pendingCmd.cmdNum == cmdNum) {
+                        found = pendingCmd;
+                        break;
+                    }
+                }
+                if (found == null) {
+                    found = new PendingCmd(cmdNum, logCmd);
+                    mPendingCmds.add(found);
+                }
+                found.availableResponseCount--;
+                // if a matching add call has already retrieved this we can remove this
+                // instance from our list
+                if (found.availableResponseCount == 0) mPendingCmds.remove(found);
+            }
+            NativeDaemonEvent result = null;
+            try {
+                result = found.responses.poll(timeoutMs, TimeUnit.MILLISECONDS);
+            } catch (InterruptedException e) {}
+            if (result == null) {
+                Log.e("NativeDaemonConnector.ResponseQueue", "Timeout waiting for response");
+            }
+            return result;
+        }
+
+        public void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
+            pw.println("Pending requests:");
+            synchronized (mPendingCmds) {
+                for (PendingCmd pendingCmd : mPendingCmds) {
+                    pw.println("  Cmd " + pendingCmd.cmdNum + " - " + pendingCmd.logCmd);
+                }
+            }
+        }
+    }
+}

service-t/src/com/android/server/NativeDaemonConnectorException.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2006 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.server;
+
+import android.os.Parcel;
+
+/**
+ * An exception that indicates there was an error with a
+ * {@link NativeDaemonConnector} operation.
+ */
+public class NativeDaemonConnectorException extends Exception {
+    private String mCmd;
+    private NativeDaemonEvent mEvent;
+
+    public NativeDaemonConnectorException(String detailMessage) {
+        super(detailMessage);
+    }
+
+    public NativeDaemonConnectorException(String detailMessage, Throwable throwable) {
+        super(detailMessage, throwable);
+    }
+
+    public NativeDaemonConnectorException(String cmd, NativeDaemonEvent event) {
+        super("command '" + cmd + "' failed with '" + event + "'");
+        mCmd = cmd;
+        mEvent = event;
+    }
+
+    public int getCode() {
+        return mEvent != null ? mEvent.getCode() : -1;
+    }
+
+    public String getCmd() {
+        return mCmd;
+    }
+
+    /**
+     * Rethrow as a {@link RuntimeException} subclass that is handled by
+     * {@link Parcel#writeException(Exception)}.
+     */
+    public IllegalArgumentException rethrowAsParcelableException() {
+        throw new IllegalStateException(getMessage(), this);
+    }
+}

service-t/src/com/android/server/NativeDaemonEvent.java

@@ -0,0 +1,267 @@
+/*
+ * Copyright (C) 2011 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.server;
+
+import android.util.Log;
+
+import java.io.FileDescriptor;
+import java.util.ArrayList;
+
+/**
+ * Parsed event from native side of {@link NativeDaemonConnector}.
+ */
+public class NativeDaemonEvent {
+
+    // TODO: keep class ranges in sync with ResponseCode.h
+    // TODO: swap client and server error ranges to roughly mirror HTTP spec
+
+    private final int mCmdNumber;
+    private final int mCode;
+    private final String mMessage;
+    private final String mRawEvent;
+    private final String mLogMessage;
+    private String[] mParsed;
+    private FileDescriptor[] mFdList;
+
+    private NativeDaemonEvent(int cmdNumber, int code, String message,
+                              String rawEvent, String logMessage, FileDescriptor[] fdList) {
+        mCmdNumber = cmdNumber;
+        mCode = code;
+        mMessage = message;
+        mRawEvent = rawEvent;
+        mLogMessage = logMessage;
+        mParsed = null;
+        mFdList = fdList;
+    }
+
+    static public final String SENSITIVE_MARKER = "{{sensitive}}";
+
+    public int getCmdNumber() {
+        return mCmdNumber;
+    }
+
+    public int getCode() {
+        return mCode;
+    }
+
+    public String getMessage() {
+        return mMessage;
+    }
+
+    public FileDescriptor[] getFileDescriptors() {
+        return mFdList;
+    }
+
+    @Deprecated
+    public String getRawEvent() {
+        return mRawEvent;
+    }
+
+    @Override
+    public String toString() {
+        return mLogMessage;
+    }
+
+    /**
+     * Test if event represents a partial response which is continued in
+     * additional subsequent events.
+     */
+    public boolean isClassContinue() {
+        return mCode >= 100 && mCode < 200;
+    }
+
+    /**
+     * Test if event represents a command success.
+     */
+    public boolean isClassOk() {
+        return mCode >= 200 && mCode < 300;
+    }
+
+    /**
+     * Test if event represents a remote native daemon error.
+     */
+    public boolean isClassServerError() {
+        return mCode >= 400 && mCode < 500;
+    }
+
+    /**
+     * Test if event represents a command syntax or argument error.
+     */
+    public boolean isClassClientError() {
+        return mCode >= 500 && mCode < 600;
+    }
+
+    /**
+     * Test if event represents an unsolicited event from native daemon.
+     */
+    public boolean isClassUnsolicited() {
+        return isClassUnsolicited(mCode);
+    }
+
+    private static boolean isClassUnsolicited(int code) {
+        return code >= 600 && code < 700;
+    }
+
+    /**
+     * Verify this event matches the given code.
+     *
+     * @throws IllegalStateException if {@link #getCode()} doesn't match.
+     */
+    public void checkCode(int code) {
+        if (mCode != code) {
+            throw new IllegalStateException("Expected " + code + " but was: " + this);
+        }
+    }
+
+    /**
+     * Parse the given raw event into {@link NativeDaemonEvent} instance.
+     *
+     * @throws IllegalArgumentException when line doesn't match format expected
+     *             from native side.
+     */
+    public static NativeDaemonEvent parseRawEvent(String rawEvent, FileDescriptor[] fdList) {
+        final String[] parsed = rawEvent.split(" ");
+        if (parsed.length < 2) {
+            throw new IllegalArgumentException("Insufficient arguments");
+        }
+
+        int skiplength = 0;
+
+        final int code;
+        try {
+            code = Integer.parseInt(parsed[0]);
+            skiplength = parsed[0].length() + 1;
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException("problem parsing code", e);
+        }
+
+        int cmdNumber = -1;
+        if (isClassUnsolicited(code) == false) {
+            if (parsed.length < 3) {
+                throw new IllegalArgumentException("Insufficient arguemnts");
+            }
+            try {
+                cmdNumber = Integer.parseInt(parsed[1]);
+                skiplength += parsed[1].length() + 1;
+            } catch (NumberFormatException e) {
+                throw new IllegalArgumentException("problem parsing cmdNumber", e);
+            }
+        }
+
+        String logMessage = rawEvent;
+        if (parsed.length > 2 && parsed[2].equals(SENSITIVE_MARKER)) {
+            skiplength += parsed[2].length() + 1;
+            logMessage = parsed[0] + " " + parsed[1] + " {}";
+        }
+
+        final String message = rawEvent.substring(skiplength);
+
+        return new NativeDaemonEvent(cmdNumber, code, message, rawEvent, logMessage, fdList);
+    }
+
+    /**
+     * Filter the given {@link NativeDaemonEvent} list, returning
+     * {@link #getMessage()} for any events matching the requested code.
+     */
+    public static String[] filterMessageList(NativeDaemonEvent[] events, int matchCode) {
+        final ArrayList<String> result = new ArrayList<>();
+        for (NativeDaemonEvent event : events) {
+            if (event.getCode() == matchCode) {
+                result.add(event.getMessage());
+            }
+        }
+        return result.toArray(new String[result.size()]);
+    }
+
+    /**
+     * Find the Nth field of the event.
+     *
+     * This ignores and code or cmdNum, the first return value is given for N=0.
+     * Also understands "\"quoted\" multiword responses" and tries them as a single field
+     */
+    public String getField(int n) {
+        if (mParsed == null) {
+            mParsed = unescapeArgs(mRawEvent);
+        }
+        n += 2; // skip code and command#
+        if (n > mParsed.length) return null;
+            return mParsed[n];
+        }
+
+    public static String[] unescapeArgs(String rawEvent) {
+        final boolean DEBUG_ROUTINE = false;
+        final String LOGTAG = "unescapeArgs";
+        final ArrayList<String> parsed = new ArrayList<String>();
+        final int length = rawEvent.length();
+        int current = 0;
+        int wordEnd = -1;
+        boolean quoted = false;
+
+        if (DEBUG_ROUTINE) Log.e(LOGTAG, "parsing '" + rawEvent + "'");
+        if (rawEvent.charAt(current) == '\"') {
+            quoted = true;
+            current++;
+        }
+        while (current < length) {
+            // find the end of the word
+            char terminator = quoted ? '\"' : ' ';
+            wordEnd = current;
+            while (wordEnd < length && rawEvent.charAt(wordEnd) != terminator) {
+                if (rawEvent.charAt(wordEnd) == '\\') {
+                    // skip the escaped char
+                    ++wordEnd;
+                }
+                ++wordEnd;
+            }
+            if (wordEnd > length) wordEnd = length;
+            String word = rawEvent.substring(current, wordEnd);
+            current += word.length();
+            if (!quoted) {
+                word = word.trim();
+            } else {
+                current++;  // skip the trailing quote
+            }
+            // unescape stuff within the word
+            word = word.replace("\\\\", "\\");
+            word = word.replace("\\\"", "\"");
+
+            if (DEBUG_ROUTINE) Log.e(LOGTAG, "found '" + word + "'");
+            parsed.add(word);
+
+            // find the beginning of the next word - either of these options
+            int nextSpace = rawEvent.indexOf(' ', current);
+            int nextQuote = rawEvent.indexOf(" \"", current);
+            if (DEBUG_ROUTINE) {
+                Log.e(LOGTAG, "nextSpace=" + nextSpace + ", nextQuote=" + nextQuote);
+            }
+            if (nextQuote > -1 && nextQuote <= nextSpace) {
+                quoted = true;
+                current = nextQuote + 2;
+            } else {
+                quoted = false;
+                if (nextSpace > -1) {
+                    current = nextSpace + 1;
+                }
+            } // else we just start the next word after the current and read til the end
+            if (DEBUG_ROUTINE) {
+                Log.e(LOGTAG, "next loop - current=" + current
+                        + ", length=" + length + ", quoted=" + quoted);
+            }
+        }
+        return parsed.toArray(new String[parsed.size()]);
+    }
+}

service-t/src/com/android/server/NativeDaemonTimeoutException.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2015 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.server;
+
+/**
+ * An exception that indicates there was a timeout with a
+ * {@link NativeDaemonConnector} operation.
+ */
+public class NativeDaemonTimeoutException extends NativeDaemonConnectorException {
+    public NativeDaemonTimeoutException(String command, NativeDaemonEvent event) {
+        super(command, event);
+    }
+}
+

service-t/src/com/android/server/net/BpfInterfaceMapUpdater.java

@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import android.content.Context;
+import android.net.INetd;
+import android.os.Handler;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.os.ServiceSpecificException;
+import android.system.ErrnoException;
+import android.util.Log;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.net.module.util.BaseNetdUnsolicitedEventListener;
+import com.android.net.module.util.BpfMap;
+import com.android.net.module.util.IBpfMap;
+import com.android.net.module.util.InterfaceParams;
+import com.android.net.module.util.Struct.U32;
+
+/**
+ * Monitor interface added (without removed) and right interface name and its index to bpf map.
+ */
+public class BpfInterfaceMapUpdater {
+    private static final String TAG = BpfInterfaceMapUpdater.class.getSimpleName();
+    // This is current path but may be changed soon.
+    private static final String IFACE_INDEX_NAME_MAP_PATH =
+            "/sys/fs/bpf/map_netd_iface_index_name_map";
+    private final IBpfMap<U32, InterfaceMapValue> mBpfMap;
+    private final INetd mNetd;
+    private final Handler mHandler;
+    private final Dependencies mDeps;
+
+    public BpfInterfaceMapUpdater(Context ctx, Handler handler) {
+        this(ctx, handler, new Dependencies());
+    }
+
+    @VisibleForTesting
+    public BpfInterfaceMapUpdater(Context ctx, Handler handler, Dependencies deps) {
+        mDeps = deps;
+        mBpfMap = deps.getInterfaceMap();
+        mNetd = deps.getINetd(ctx);
+        mHandler = handler;
+    }
+
+    /**
+     * Dependencies of BpfInerfaceMapUpdater, for injection in tests.
+     */
+    @VisibleForTesting
+    public static class Dependencies {
+        /** Create BpfMap for updating interface and index mapping. */
+        public IBpfMap<U32, InterfaceMapValue> getInterfaceMap() {
+            try {
+                return new BpfMap<>(IFACE_INDEX_NAME_MAP_PATH, BpfMap.BPF_F_RDWR,
+                    U32.class, InterfaceMapValue.class);
+            } catch (ErrnoException e) {
+                Log.e(TAG, "Cannot create interface map: " + e);
+                return null;
+            }
+        }
+
+        /** Get InterfaceParams for giving interface name. */
+        public InterfaceParams getInterfaceParams(String ifaceName) {
+            return InterfaceParams.getByName(ifaceName);
+        }
+
+        /** Get INetd binder object. */
+        public INetd getINetd(Context ctx) {
+            return INetd.Stub.asInterface((IBinder) ctx.getSystemService(Context.NETD_SERVICE));
+        }
+    }
+
+    /**
+     * Start listening interface update event.
+     * Query current interface names before listening.
+     */
+    public void start() {
+        mHandler.post(() -> {
+            if (mBpfMap == null) {
+                Log.wtf(TAG, "Fail to start: Null bpf map");
+                return;
+            }
+
+            try {
+                // TODO: use a NetlinkMonitor and listen for RTM_NEWLINK messages instead.
+                mNetd.registerUnsolicitedEventListener(new InterfaceChangeObserver());
+            } catch (RemoteException e) {
+                Log.wtf(TAG, "Unable to register netd UnsolicitedEventListener, " + e);
+            }
+
+            final String[] ifaces;
+            try {
+                // TODO: use a netlink dump to get the current interface list.
+                ifaces = mNetd.interfaceGetList();
+            } catch (RemoteException | ServiceSpecificException e) {
+                Log.wtf(TAG, "Unable to query interface names by netd, " + e);
+                return;
+            }
+
+            for (String ifaceName : ifaces) {
+                addInterface(ifaceName);
+            }
+        });
+    }
+
+    private void addInterface(String ifaceName) {
+        final InterfaceParams iface = mDeps.getInterfaceParams(ifaceName);
+        if (iface == null) {
+            Log.e(TAG, "Unable to get InterfaceParams for " + ifaceName);
+            return;
+        }
+
+        try {
+            mBpfMap.updateEntry(new U32(iface.index), new InterfaceMapValue(ifaceName));
+        } catch (ErrnoException e) {
+            Log.e(TAG, "Unable to update entry for " + ifaceName + ", " + e);
+        }
+    }
+
+    private class InterfaceChangeObserver extends BaseNetdUnsolicitedEventListener {
+        @Override
+        public void onInterfaceAdded(String ifName) {
+            mHandler.post(() -> addInterface(ifName));
+        }
+    }
+}

service-t/src/com/android/server/net/CookieTagMapKey.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * Key for cookie tag map.
+ */
+public class CookieTagMapKey extends Struct {
+    @Field(order = 0, type = Type.S64)
+    public final long socketCookie;
+
+    public CookieTagMapKey(final long socketCookie) {
+        this.socketCookie = socketCookie;
+    }
+}

service-t/src/com/android/server/net/CookieTagMapValue.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * Value for cookie tag map.
+ */
+public class CookieTagMapValue extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long uid;
+
+    @Field(order = 1, type = Type.U32)
+    public final long tag;
+
+    public CookieTagMapValue(final long uid, final long tag) {
+        this.uid = uid;
+        this.tag = tag;
+    }
+}

service-t/src/com/android/server/net/DelayedDiskWrite.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2014 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.server.net;
+
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.io.BufferedOutputStream;
+import java.io.DataOutputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+/**
+ * This class provides APIs to do a delayed data write to a given {@link OutputStream}.
+ */
+public class DelayedDiskWrite {
+    private static final String TAG = "DelayedDiskWrite";
+
+    private HandlerThread mDiskWriteHandlerThread;
+    private Handler mDiskWriteHandler;
+    /* Tracks multiple writes on the same thread */
+    private int mWriteSequence = 0;
+
+    /**
+     * Used to do a delayed data write to a given {@link OutputStream}.
+     */
+    public interface Writer {
+        /**
+         * write data to a given {@link OutputStream}.
+         */
+        void onWriteCalled(DataOutputStream out) throws IOException;
+    }
+
+    /**
+     * Do a delayed data write to a given output stream opened from filePath.
+     */
+    public void write(final String filePath, final Writer w) {
+        write(filePath, w, true);
+    }
+
+    /**
+     * Do a delayed data write to a given output stream opened from filePath.
+     */
+    public void write(final String filePath, final Writer w, final boolean open) {
+        if (TextUtils.isEmpty(filePath)) {
+            throw new IllegalArgumentException("empty file path");
+        }
+
+        /* Do a delayed write to disk on a separate handler thread */
+        synchronized (this) {
+            if (++mWriteSequence == 1) {
+                mDiskWriteHandlerThread = new HandlerThread("DelayedDiskWriteThread");
+                mDiskWriteHandlerThread.start();
+                mDiskWriteHandler = new Handler(mDiskWriteHandlerThread.getLooper());
+            }
+        }
+
+        mDiskWriteHandler.post(new Runnable() {
+            @Override
+            public void run() {
+                doWrite(filePath, w, open);
+            }
+        });
+    }
+
+    private void doWrite(String filePath, Writer w, boolean open) {
+        DataOutputStream out = null;
+        try {
+            if (open) {
+                out = new DataOutputStream(new BufferedOutputStream(
+                        new FileOutputStream(filePath)));
+            }
+            w.onWriteCalled(out);
+        } catch (IOException e) {
+            loge("Error writing data file " + filePath);
+        } finally {
+            if (out != null) {
+                try {
+                    out.close();
+                } catch (Exception e) { }
+            }
+
+            // Quit if no more writes sent
+            synchronized (this) {
+                if (--mWriteSequence == 0) {
+                    mDiskWriteHandler.getLooper().quit();
+                    mDiskWriteHandler = null;
+                    mDiskWriteHandlerThread = null;
+                }
+            }
+        }
+    }
+
+    private void loge(String s) {
+        Log.e(TAG, s);
+    }
+}
+

service-t/src/com/android/server/net/InterfaceMapValue.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * The value of bpf interface index map which is used for NetworkStatsService.
+ */
+public class InterfaceMapValue extends Struct {
+    @Field(order = 0, type = Type.ByteArray, arraysize = 16)
+    public final byte[] interfaceName;
+
+    public InterfaceMapValue(String iface) {
+        final byte[] ifaceArray = iface.getBytes();
+        interfaceName = new byte[16];
+        // All array bytes after the interface name, if any, must be 0.
+        System.arraycopy(ifaceArray, 0, interfaceName, 0, ifaceArray.length);
+    }
+}

service-t/src/com/android/server/net/IpConfigStore.java

@@ -0,0 +1,449 @@
+/*
+ * Copyright (C) 2014 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.server.net;
+
+import android.net.InetAddresses;
+import android.net.IpConfiguration;
+import android.net.IpConfiguration.IpAssignment;
+import android.net.IpConfiguration.ProxySettings;
+import android.net.LinkAddress;
+import android.net.ProxyInfo;
+import android.net.StaticIpConfiguration;
+import android.net.Uri;
+import android.util.ArrayMap;
+import android.util.Log;
+import android.util.SparseArray;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.net.module.util.ProxyUtils;
+
+import java.io.BufferedInputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.EOFException;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This class provides an API to store and manage L3 network IP configuration.
+ */
+public class IpConfigStore {
+    private static final String TAG = "IpConfigStore";
+    private static final boolean DBG = false;
+
+    protected final DelayedDiskWrite mWriter;
+
+    /* IP and proxy configuration keys */
+    protected static final String ID_KEY = "id";
+    protected static final String IP_ASSIGNMENT_KEY = "ipAssignment";
+    protected static final String LINK_ADDRESS_KEY = "linkAddress";
+    protected static final String GATEWAY_KEY = "gateway";
+    protected static final String DNS_KEY = "dns";
+    protected static final String PROXY_SETTINGS_KEY = "proxySettings";
+    protected static final String PROXY_HOST_KEY = "proxyHost";
+    protected static final String PROXY_PORT_KEY = "proxyPort";
+    protected static final String PROXY_PAC_FILE = "proxyPac";
+    protected static final String EXCLUSION_LIST_KEY = "exclusionList";
+    protected static final String EOS = "eos";
+
+    protected static final int IPCONFIG_FILE_VERSION = 3;
+
+    public IpConfigStore(DelayedDiskWrite writer) {
+        mWriter = writer;
+    }
+
+    public IpConfigStore() {
+        this(new DelayedDiskWrite());
+    }
+
+    private static boolean writeConfig(DataOutputStream out, String configKey,
+            IpConfiguration config) throws IOException {
+        return writeConfig(out, configKey, config, IPCONFIG_FILE_VERSION);
+    }
+
+    /**
+     *  Write the IP configuration with the given parameters to {@link DataOutputStream}.
+     */
+    @VisibleForTesting
+    public static boolean writeConfig(DataOutputStream out, String configKey,
+                                IpConfiguration config, int version) throws IOException {
+        boolean written = false;
+
+        try {
+            switch (config.getIpAssignment()) {
+                case STATIC:
+                    out.writeUTF(IP_ASSIGNMENT_KEY);
+                    out.writeUTF(config.getIpAssignment().toString());
+                    StaticIpConfiguration staticIpConfiguration = config.getStaticIpConfiguration();
+                    if (staticIpConfiguration != null) {
+                        if (staticIpConfiguration.getIpAddress() != null) {
+                            LinkAddress ipAddress = staticIpConfiguration.getIpAddress();
+                            out.writeUTF(LINK_ADDRESS_KEY);
+                            out.writeUTF(ipAddress.getAddress().getHostAddress());
+                            out.writeInt(ipAddress.getPrefixLength());
+                        }
+                        if (staticIpConfiguration.getGateway() != null) {
+                            out.writeUTF(GATEWAY_KEY);
+                            out.writeInt(0);  // Default route.
+                            out.writeInt(1);  // Have a gateway.
+                            out.writeUTF(staticIpConfiguration.getGateway().getHostAddress());
+                        }
+                        for (InetAddress inetAddr : staticIpConfiguration.getDnsServers()) {
+                            out.writeUTF(DNS_KEY);
+                            out.writeUTF(inetAddr.getHostAddress());
+                        }
+                    }
+                    written = true;
+                    break;
+                case DHCP:
+                    out.writeUTF(IP_ASSIGNMENT_KEY);
+                    out.writeUTF(config.getIpAssignment().toString());
+                    written = true;
+                    break;
+                case UNASSIGNED:
+                /* Ignore */
+                    break;
+                default:
+                    loge("Ignore invalid ip assignment while writing");
+                    break;
+            }
+
+            switch (config.getProxySettings()) {
+                case STATIC:
+                    ProxyInfo proxyProperties = config.getHttpProxy();
+                    String exclusionList = ProxyUtils.exclusionListAsString(
+                            proxyProperties.getExclusionList());
+                    out.writeUTF(PROXY_SETTINGS_KEY);
+                    out.writeUTF(config.getProxySettings().toString());
+                    out.writeUTF(PROXY_HOST_KEY);
+                    out.writeUTF(proxyProperties.getHost());
+                    out.writeUTF(PROXY_PORT_KEY);
+                    out.writeInt(proxyProperties.getPort());
+                    if (exclusionList != null) {
+                        out.writeUTF(EXCLUSION_LIST_KEY);
+                        out.writeUTF(exclusionList);
+                    }
+                    written = true;
+                    break;
+                case PAC:
+                    ProxyInfo proxyPacProperties = config.getHttpProxy();
+                    out.writeUTF(PROXY_SETTINGS_KEY);
+                    out.writeUTF(config.getProxySettings().toString());
+                    out.writeUTF(PROXY_PAC_FILE);
+                    out.writeUTF(proxyPacProperties.getPacFileUrl().toString());
+                    written = true;
+                    break;
+                case NONE:
+                    out.writeUTF(PROXY_SETTINGS_KEY);
+                    out.writeUTF(config.getProxySettings().toString());
+                    written = true;
+                    break;
+                case UNASSIGNED:
+                    /* Ignore */
+                    break;
+                default:
+                    loge("Ignore invalid proxy settings while writing");
+                    break;
+            }
+
+            if (written) {
+                out.writeUTF(ID_KEY);
+                if (version < 3) {
+                    out.writeInt(Integer.valueOf(configKey));
+                } else {
+                    out.writeUTF(configKey);
+                }
+            }
+        } catch (NullPointerException e) {
+            loge("Failure in writing " + config + e);
+        }
+        out.writeUTF(EOS);
+
+        return written;
+    }
+
+    /**
+     * @deprecated use {@link #writeIpConfigurations(String, ArrayMap)} instead.
+     * New method uses string as network identifier which could be interface name or MAC address or
+     * other token.
+     */
+    @Deprecated
+    public void writeIpAndProxyConfigurationsToFile(String filePath,
+                                              final SparseArray<IpConfiguration> networks) {
+        mWriter.write(filePath, out -> {
+            out.writeInt(IPCONFIG_FILE_VERSION);
+            for (int i = 0; i < networks.size(); i++) {
+                writeConfig(out, String.valueOf(networks.keyAt(i)), networks.valueAt(i));
+            }
+        });
+    }
+
+    /**
+     *  Write the IP configuration associated to the target networks to the destination path.
+     */
+    public void writeIpConfigurations(String filePath,
+                                      ArrayMap<String, IpConfiguration> networks) {
+        mWriter.write(filePath, out -> {
+            out.writeInt(IPCONFIG_FILE_VERSION);
+            for (int i = 0; i < networks.size(); i++) {
+                writeConfig(out, networks.keyAt(i), networks.valueAt(i));
+            }
+        });
+    }
+
+    /**
+     * Read the IP configuration from the destination path to {@link BufferedInputStream}.
+     */
+    public static ArrayMap<String, IpConfiguration> readIpConfigurations(String filePath) {
+        BufferedInputStream bufferedInputStream;
+        try {
+            bufferedInputStream = new BufferedInputStream(new FileInputStream(filePath));
+        } catch (FileNotFoundException e) {
+            // Return an empty array here because callers expect an empty array when the file is
+            // not present.
+            loge("Error opening configuration file: " + e);
+            return new ArrayMap<>(0);
+        }
+        return readIpConfigurations(bufferedInputStream);
+    }
+
+    /** @deprecated use {@link #readIpConfigurations(String)} */
+    @Deprecated
+    public static SparseArray<IpConfiguration> readIpAndProxyConfigurations(String filePath) {
+        BufferedInputStream bufferedInputStream;
+        try {
+            bufferedInputStream = new BufferedInputStream(new FileInputStream(filePath));
+        } catch (FileNotFoundException e) {
+            // Return an empty array here because callers expect an empty array when the file is
+            // not present.
+            loge("Error opening configuration file: " + e);
+            return new SparseArray<>();
+        }
+        return readIpAndProxyConfigurations(bufferedInputStream);
+    }
+
+    /** @deprecated use {@link #readIpConfigurations(InputStream)} */
+    @Deprecated
+    public static SparseArray<IpConfiguration> readIpAndProxyConfigurations(
+            InputStream inputStream) {
+        ArrayMap<String, IpConfiguration> networks = readIpConfigurations(inputStream);
+        if (networks == null) {
+            return null;
+        }
+
+        SparseArray<IpConfiguration> networksById = new SparseArray<>();
+        for (int i = 0; i < networks.size(); i++) {
+            int id = Integer.valueOf(networks.keyAt(i));
+            networksById.put(id, networks.valueAt(i));
+        }
+
+        return networksById;
+    }
+
+    /** Returns a map of network identity token and {@link IpConfiguration}. */
+    public static ArrayMap<String, IpConfiguration> readIpConfigurations(
+            InputStream inputStream) {
+        ArrayMap<String, IpConfiguration> networks = new ArrayMap<>();
+        DataInputStream in = null;
+        try {
+            in = new DataInputStream(inputStream);
+
+            int version = in.readInt();
+            if (version != 3 && version != 2 && version != 1) {
+                loge("Bad version on IP configuration file, ignore read");
+                return null;
+            }
+
+            while (true) {
+                String uniqueToken = null;
+                // Default is DHCP with no proxy
+                IpAssignment ipAssignment = IpAssignment.DHCP;
+                ProxySettings proxySettings = ProxySettings.NONE;
+                StaticIpConfiguration staticIpConfiguration = new StaticIpConfiguration();
+                LinkAddress linkAddress = null;
+                InetAddress gatewayAddress = null;
+                String proxyHost = null;
+                String pacFileUrl = null;
+                int proxyPort = -1;
+                String exclusionList = null;
+                String key;
+                final List<InetAddress> dnsServers = new ArrayList<>();
+
+                do {
+                    key = in.readUTF();
+                    try {
+                        if (key.equals(ID_KEY)) {
+                            if (version < 3) {
+                                int id = in.readInt();
+                                uniqueToken = String.valueOf(id);
+                            } else {
+                                uniqueToken = in.readUTF();
+                            }
+                        } else if (key.equals(IP_ASSIGNMENT_KEY)) {
+                            ipAssignment = IpAssignment.valueOf(in.readUTF());
+                        } else if (key.equals(LINK_ADDRESS_KEY)) {
+                            LinkAddress parsedLinkAddress =
+                                    new LinkAddress(
+                                            InetAddresses.parseNumericAddress(in.readUTF()),
+                                            in.readInt());
+                            if (parsedLinkAddress.getAddress() instanceof Inet4Address
+                                    && linkAddress == null) {
+                                linkAddress = parsedLinkAddress;
+                            } else {
+                                loge("Non-IPv4 or duplicate address: " + parsedLinkAddress);
+                            }
+                        } else if (key.equals(GATEWAY_KEY)) {
+                            LinkAddress dest = null;
+                            InetAddress gateway = null;
+                            if (version == 1) {
+                                // only supported default gateways - leave the dest/prefix empty
+                                gateway = InetAddresses.parseNumericAddress(in.readUTF());
+                                if (gatewayAddress == null) {
+                                    gatewayAddress = gateway;
+                                } else {
+                                    loge("Duplicate gateway: " + gateway.getHostAddress());
+                                }
+                            } else {
+                                if (in.readInt() == 1) {
+                                    dest =
+                                            new LinkAddress(
+                                                    InetAddresses.parseNumericAddress(in.readUTF()),
+                                                    in.readInt());
+                                }
+                                if (in.readInt() == 1) {
+                                    gateway = InetAddresses.parseNumericAddress(in.readUTF());
+                                }
+                                // If the destination is a default IPv4 route, use the gateway
+                                // address unless already set. If there is no destination, assume
+                                // it is default route and use the gateway address in all cases.
+                                if (dest == null) {
+                                    gatewayAddress = gateway;
+                                } else if (dest.getAddress() instanceof Inet4Address
+                                        && dest.getPrefixLength() == 0 && gatewayAddress == null) {
+                                    gatewayAddress = gateway;
+                                } else {
+                                    loge("Non-IPv4 default or duplicate route: "
+                                            + dest.getAddress());
+                                }
+                            }
+                        } else if (key.equals(DNS_KEY)) {
+                            dnsServers.add(InetAddresses.parseNumericAddress(in.readUTF()));
+                        } else if (key.equals(PROXY_SETTINGS_KEY)) {
+                            proxySettings = ProxySettings.valueOf(in.readUTF());
+                        } else if (key.equals(PROXY_HOST_KEY)) {
+                            proxyHost = in.readUTF();
+                        } else if (key.equals(PROXY_PORT_KEY)) {
+                            proxyPort = in.readInt();
+                        } else if (key.equals(PROXY_PAC_FILE)) {
+                            pacFileUrl = in.readUTF();
+                        } else if (key.equals(EXCLUSION_LIST_KEY)) {
+                            exclusionList = in.readUTF();
+                        } else if (key.equals(EOS)) {
+                            break;
+                        } else {
+                            loge("Ignore unknown key " + key + "while reading");
+                        }
+                    } catch (IllegalArgumentException e) {
+                        loge("Ignore invalid address while reading" + e);
+                    }
+                } while (true);
+
+                staticIpConfiguration = new StaticIpConfiguration.Builder()
+                    .setIpAddress(linkAddress)
+                    .setGateway(gatewayAddress)
+                    .setDnsServers(dnsServers)
+                    .build();
+
+                if (uniqueToken != null) {
+                    IpConfiguration config = new IpConfiguration();
+                    networks.put(uniqueToken, config);
+
+                    switch (ipAssignment) {
+                        case STATIC:
+                            config.setStaticIpConfiguration(staticIpConfiguration);
+                            config.setIpAssignment(ipAssignment);
+                            break;
+                        case DHCP:
+                            config.setIpAssignment(ipAssignment);
+                            break;
+                        case UNASSIGNED:
+                            loge("BUG: Found UNASSIGNED IP on file, use DHCP");
+                            config.setIpAssignment(IpAssignment.DHCP);
+                            break;
+                        default:
+                            loge("Ignore invalid ip assignment while reading.");
+                            config.setIpAssignment(IpAssignment.UNASSIGNED);
+                            break;
+                    }
+
+                    switch (proxySettings) {
+                        case STATIC:
+                            ProxyInfo proxyInfo = ProxyInfo.buildDirectProxy(proxyHost, proxyPort,
+                                    ProxyUtils.exclusionStringAsList(exclusionList));
+                            config.setProxySettings(proxySettings);
+                            config.setHttpProxy(proxyInfo);
+                            break;
+                        case PAC:
+                            ProxyInfo proxyPacProperties =
+                                    ProxyInfo.buildPacProxy(Uri.parse(pacFileUrl));
+                            config.setProxySettings(proxySettings);
+                            config.setHttpProxy(proxyPacProperties);
+                            break;
+                        case NONE:
+                            config.setProxySettings(proxySettings);
+                            break;
+                        case UNASSIGNED:
+                            loge("BUG: Found UNASSIGNED proxy on file, use NONE");
+                            config.setProxySettings(ProxySettings.NONE);
+                            break;
+                        default:
+                            loge("Ignore invalid proxy settings while reading");
+                            config.setProxySettings(ProxySettings.UNASSIGNED);
+                            break;
+                    }
+                } else {
+                    if (DBG) log("Missing id while parsing configuration");
+                }
+            }
+        } catch (EOFException ignore) {
+        } catch (IOException e) {
+            loge("Error parsing configuration: " + e);
+        } finally {
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (Exception e) { }
+            }
+        }
+
+        return networks;
+    }
+
+    protected static void loge(String s) {
+        Log.e(TAG, s);
+    }
+
+    protected static void log(String s) {
+        Log.d(TAG, s);
+    }
+}

service-t/src/com/android/server/net/NetworkStatsFactory.java

@@ -0,0 +1,505 @@
+/*
+ * Copyright (C) 2011 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.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;
+import static android.net.NetworkStats.UID_ALL;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.net.NetworkStats;
+import android.net.UnderlyingNetworkInfo;
+import android.os.ServiceSpecificException;
+import android.os.StrictMode;
+import android.os.SystemClock;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.ProcFileReader;
+import com.android.net.module.util.CollectionUtils;
+import com.android.server.BpfNetMaps;
+
+import libcore.io.IoUtils;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.net.ProtocolException;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Creates {@link NetworkStats} instances by parsing various {@code /proc/}
+ * files as needed.
+ *
+ * @hide
+ */
+public class NetworkStatsFactory {
+    static {
+        System.loadLibrary("service-connectivity");
+    }
+
+    private static final String TAG = "NetworkStatsFactory";
+
+    private static final boolean USE_NATIVE_PARSING = true;
+    private static final boolean VALIDATE_NATIVE_STATS = false;
+
+    /** Path to {@code /proc/net/xt_qtaguid/iface_stat_all}. */
+    private final File mStatsXtIfaceAll;
+    /** Path to {@code /proc/net/xt_qtaguid/iface_stat_fmt}. */
+    private final File mStatsXtIfaceFmt;
+    /** Path to {@code /proc/net/xt_qtaguid/stats}. */
+    private final File mStatsXtUid;
+
+    private final boolean mUseBpfStats;
+
+    private final Context mContext;
+
+    private final BpfNetMaps mBpfNetMaps;
+
+    /**
+     * Guards persistent data access in this class
+     *
+     * <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 final Object mPersistentDataLock = new Object();
+
+    /** Set containing info about active VPNs and their underlying networks. */
+    private volatile UnderlyingNetworkInfo[] mUnderlyingNetworkInfos = new UnderlyingNetworkInfo[0];
+
+    // A persistent snapshot of cumulative stats since device start
+    @GuardedBy("mPersistentDataLock")
+    private NetworkStats mPersistSnapshot;
+
+    // The persistent snapshot of tun and 464xlat adjusted stats since device start
+    @GuardedBy("mPersistentDataLock")
+    private NetworkStats mTunAnd464xlatAdjustedStats;
+
+    /**
+     * (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 final ConcurrentHashMap<String, String> mStackedIfaces
+            = new ConcurrentHashMap<>();
+
+    /** Informs the factory of a new stacked interface. */
+    public void noteStackedIface(String stackedIface, String baseIface) {
+        if (stackedIface != null && baseIface != null) {
+            mStackedIfaces.put(stackedIface, baseIface);
+        }
+    }
+
+    /**
+     * 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 void updateUnderlyingNetworkInfos(UnderlyingNetworkInfo[] vpnArray) {
+        mUnderlyingNetworkInfos = vpnArray.clone();
+    }
+
+    /**
+     * 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 String[] augmentWithStackedInterfaces(@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 : mStackedIfaces.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);
+    }
+
+    /**
+     * Applies 464xlat adjustments with ifaces noted with {@link #noteStackedIface(String, String)}.
+     * @see NetworkStats#apply464xlatAdjustments(NetworkStats, NetworkStats, Map)
+     */
+    public void apply464xlatAdjustments(NetworkStats baseTraffic, NetworkStats stackedTraffic) {
+        NetworkStats.apply464xlatAdjustments(baseTraffic, stackedTraffic, mStackedIfaces);
+    }
+
+    public NetworkStatsFactory(@NonNull Context ctx) {
+        this(ctx, new File("/proc/"), true);
+    }
+
+    @VisibleForTesting
+    public NetworkStatsFactory(@NonNull Context ctx, File procRoot, boolean useBpfStats) {
+        mStatsXtIfaceAll = new File(procRoot, "net/xt_qtaguid/iface_stat_all");
+        mStatsXtIfaceFmt = new File(procRoot, "net/xt_qtaguid/iface_stat_fmt");
+        mStatsXtUid = new File(procRoot, "net/xt_qtaguid/stats");
+        mUseBpfStats = useBpfStats;
+        mBpfNetMaps = new BpfNetMaps();
+        synchronized (mPersistentDataLock) {
+            mPersistSnapshot = new NetworkStats(SystemClock.elapsedRealtime(), -1);
+            mTunAnd464xlatAdjustedStats = new NetworkStats(SystemClock.elapsedRealtime(), -1);
+        }
+        mContext = ctx;
+    }
+
+    public NetworkStats readBpfNetworkStatsDev() throws IOException {
+        final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 6);
+        if (nativeReadNetworkStatsDev(stats) != 0) {
+            throw new IOException("Failed to parse bpf iface stats");
+        }
+        return stats;
+    }
+
+    /**
+     * Parse and return interface-level summary {@link NetworkStats} measured
+     * using {@code /proc/net/dev} style hooks, which may include non IP layer
+     * traffic. Values monotonically increase since device boot, and may include
+     * details about inactive interfaces.
+     *
+     * @throws IllegalStateException when problem parsing stats.
+     */
+    public NetworkStats readNetworkStatsSummaryDev() throws IOException {
+
+        // Return xt_bpf stats if switched to bpf module.
+        if (mUseBpfStats)
+            return readBpfNetworkStatsDev();
+
+        final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
+
+        final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 6);
+        final NetworkStats.Entry entry = new NetworkStats.Entry();
+
+        ProcFileReader reader = null;
+        try {
+            reader = new ProcFileReader(new FileInputStream(mStatsXtIfaceAll));
+
+            while (reader.hasMoreData()) {
+                entry.iface = reader.nextString();
+                entry.uid = UID_ALL;
+                entry.set = SET_ALL;
+                entry.tag = TAG_NONE;
+
+                final boolean active = reader.nextInt() != 0;
+
+                // always include snapshot values
+                entry.rxBytes = reader.nextLong();
+                entry.rxPackets = reader.nextLong();
+                entry.txBytes = reader.nextLong();
+                entry.txPackets = reader.nextLong();
+
+                // fold in active numbers, but only when active
+                if (active) {
+                    entry.rxBytes += reader.nextLong();
+                    entry.rxPackets += reader.nextLong();
+                    entry.txBytes += reader.nextLong();
+                    entry.txPackets += reader.nextLong();
+                }
+
+                stats.insertEntry(entry);
+                reader.finishLine();
+            }
+        } catch (NullPointerException|NumberFormatException e) {
+            throw protocolExceptionWithCause("problem parsing stats", e);
+        } finally {
+            IoUtils.closeQuietly(reader);
+            StrictMode.setThreadPolicy(savedPolicy);
+        }
+        return stats;
+    }
+
+    /**
+     * Parse and return interface-level summary {@link NetworkStats}. Designed
+     * to return only IP layer traffic. Values monotonically increase since
+     * device boot, and may include details about inactive interfaces.
+     *
+     * @throws IllegalStateException when problem parsing stats.
+     */
+    public NetworkStats readNetworkStatsSummaryXt() throws IOException {
+
+        // Return xt_bpf stats if qtaguid  module is replaced.
+        if (mUseBpfStats)
+            return readBpfNetworkStatsDev();
+
+        final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
+
+        // return null when kernel doesn't support
+        if (!mStatsXtIfaceFmt.exists()) return null;
+
+        final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 6);
+        final NetworkStats.Entry entry = new NetworkStats.Entry();
+
+        ProcFileReader reader = null;
+        try {
+            // open and consume header line
+            reader = new ProcFileReader(new FileInputStream(mStatsXtIfaceFmt));
+            reader.finishLine();
+
+            while (reader.hasMoreData()) {
+                entry.iface = reader.nextString();
+                entry.uid = UID_ALL;
+                entry.set = SET_ALL;
+                entry.tag = TAG_NONE;
+
+                entry.rxBytes = reader.nextLong();
+                entry.rxPackets = reader.nextLong();
+                entry.txBytes = reader.nextLong();
+                entry.txPackets = reader.nextLong();
+
+                stats.insertEntry(entry);
+                reader.finishLine();
+            }
+        } catch (NullPointerException|NumberFormatException e) {
+            throw protocolExceptionWithCause("problem parsing stats", e);
+        } finally {
+            IoUtils.closeQuietly(reader);
+            StrictMode.setThreadPolicy(savedPolicy);
+        }
+        return stats;
+    }
+
+    public NetworkStats readNetworkStatsDetail() throws IOException {
+        return readNetworkStatsDetail(UID_ALL, INTERFACES_ALL, TAG_ALL);
+    }
+
+    @GuardedBy("mPersistentDataLock")
+    private void requestSwapActiveStatsMapLocked() throws IOException {
+        try {
+            // Do a active map stats swap. Once the swap completes, this code
+            // can read and clean the inactive map without races.
+            mBpfNetMaps.swapActiveStatsMap();
+        } catch (ServiceSpecificException e) {
+            throw new IOException(e);
+        }
+    }
+
+    /**
+     * Reads the detailed UID stats based on the provided parameters
+     *
+     * @param limitUid the UID to limit this query to
+     * @param limitIfaces the interfaces to limit this query to. Use {@link
+     *     NetworkStats.INTERFACES_ALL} to select all interfaces
+     * @param limitTag the tags to limit this query to
+     * @return the NetworkStats instance containing network statistics at the present time.
+     */
+    public NetworkStats readNetworkStatsDetail(
+            int limitUid, String[] limitIfaces, int limitTag) throws IOException {
+        // In order to prevent deadlocks, anything protected by this lock MUST NOT call out to other
+        // code that will acquire other locks within the system server. See b/134244752.
+        synchronized (mPersistentDataLock) {
+            // Take a reference. If this gets swapped out, we still have the old reference.
+            final UnderlyingNetworkInfo[] vpnArray = mUnderlyingNetworkInfos;
+            // Take a defensive copy. mPersistSnapshot is mutated in some cases below
+            final NetworkStats prev = mPersistSnapshot.clone();
+
+            if (USE_NATIVE_PARSING) {
+                final NetworkStats stats =
+                        new NetworkStats(SystemClock.elapsedRealtime(), 0 /* initialSize */);
+                if (mUseBpfStats) {
+                    requestSwapActiveStatsMapLocked();
+                    // Stats are always read from the inactive map, so they must be read after the
+                    // swap
+                    if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), UID_ALL,
+                            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);
+                } else {
+                    if (nativeReadNetworkStatsDetail(stats, mStatsXtUid.getAbsolutePath(), UID_ALL,
+                            INTERFACES_ALL, TAG_ALL, mUseBpfStats) != 0) {
+                        throw new IOException("Failed to parse network stats");
+                    }
+                    if (VALIDATE_NATIVE_STATS) {
+                        final NetworkStats javaStats = javaReadNetworkStatsDetail(mStatsXtUid,
+                                UID_ALL, INTERFACES_ALL, TAG_ALL);
+                        assertEquals(javaStats, stats);
+                    }
+
+                    mPersistSnapshot = stats;
+                }
+            } else {
+                mPersistSnapshot = javaReadNetworkStatsDetail(mStatsXtUid, UID_ALL, INTERFACES_ALL,
+                        TAG_ALL);
+            }
+
+            NetworkStats adjustedStats = adjustForTunAnd464Xlat(mPersistSnapshot, prev, vpnArray);
+
+            // Filter return values
+            adjustedStats.filter(limitUid, limitIfaces, limitTag);
+            return adjustedStats;
+        }
+    }
+
+    @GuardedBy("mPersistentDataLock")
+    private NetworkStats adjustForTunAnd464Xlat(NetworkStats uidDetailStats,
+            NetworkStats previousStats, UnderlyingNetworkInfo[] 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(mStackedIfaces);
+
+        // Migrate data usage over a VPN to the TUN network.
+        for (UnderlyingNetworkInfo info : vpnArray) {
+            delta.migrateTun(info.getOwnerUid(), info.getInterface(),
+                    info.getUnderlyingInterfaces());
+            // 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.
+     */
+    @VisibleForTesting
+    public static NetworkStats javaReadNetworkStatsDetail(File detailPath, int limitUid,
+            String[] limitIfaces, int limitTag)
+            throws IOException {
+        final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
+
+        final NetworkStats stats = new NetworkStats(SystemClock.elapsedRealtime(), 24);
+        final NetworkStats.Entry entry = new NetworkStats.Entry();
+
+        int idx = 1;
+        int lastIdx = 1;
+
+        ProcFileReader reader = null;
+        try {
+            // open and consume header line
+            reader = new ProcFileReader(new FileInputStream(detailPath));
+            reader.finishLine();
+
+            while (reader.hasMoreData()) {
+                idx = reader.nextInt();
+                if (idx != lastIdx + 1) {
+                    throw new ProtocolException(
+                            "inconsistent idx=" + idx + " after lastIdx=" + lastIdx);
+                }
+                lastIdx = idx;
+
+                entry.iface = reader.nextString();
+                entry.tag = kernelToTag(reader.nextString());
+                entry.uid = reader.nextInt();
+                entry.set = reader.nextInt();
+                entry.rxBytes = reader.nextLong();
+                entry.rxPackets = reader.nextLong();
+                entry.txBytes = reader.nextLong();
+                entry.txPackets = reader.nextLong();
+
+                if ((limitIfaces == null || CollectionUtils.contains(limitIfaces, entry.iface))
+                        && (limitUid == UID_ALL || limitUid == entry.uid)
+                        && (limitTag == TAG_ALL || limitTag == entry.tag)) {
+                    stats.insertEntry(entry);
+                }
+
+                reader.finishLine();
+            }
+        } catch (NullPointerException|NumberFormatException e) {
+            throw protocolExceptionWithCause("problem parsing idx " + idx, e);
+        } finally {
+            IoUtils.closeQuietly(reader);
+            StrictMode.setThreadPolicy(savedPolicy);
+        }
+
+        return stats;
+    }
+
+    public void assertEquals(NetworkStats expected, NetworkStats actual) {
+        if (expected.size() != actual.size()) {
+            throw new AssertionError(
+                    "Expected size " + expected.size() + ", actual size " + actual.size());
+        }
+
+        NetworkStats.Entry expectedRow = null;
+        NetworkStats.Entry actualRow = null;
+        for (int i = 0; i < expected.size(); i++) {
+            expectedRow = expected.getValues(i, expectedRow);
+            actualRow = actual.getValues(i, actualRow);
+            if (!expectedRow.equals(actualRow)) {
+                throw new AssertionError(
+                        "Expected row " + i + ": " + expectedRow + ", actual row " + actualRow);
+            }
+        }
+    }
+
+    /**
+     * Convert {@code /proc/} tag format to {@link Integer}. Assumes incoming
+     * format like {@code 0x7fffffff00000000}.
+     */
+    public static int kernelToTag(String string) {
+        int length = string.length();
+        if (length > 10) {
+            return Long.decode(string.substring(0, length - 8)).intValue();
+        } else {
+            return 0;
+        }
+    }
+
+    /**
+     * Parse statistics from file into given {@link NetworkStats} object. Values
+     * are expected to monotonically increase since device boot.
+     */
+    @VisibleForTesting
+    public static native int nativeReadNetworkStatsDetail(NetworkStats stats, String path,
+        int limitUid, String[] limitIfaces, int limitTag, boolean useBpfStats);
+
+    @VisibleForTesting
+    public static native int nativeReadNetworkStatsDev(NetworkStats stats);
+
+    private static ProtocolException protocolExceptionWithCause(String message, Throwable cause) {
+        ProtocolException pe = new ProtocolException(message);
+        pe.initCause(cause);
+        return pe;
+    }
+}

service-t/src/com/android/server/net/NetworkStatsObservers.java

@@ -0,0 +1,451 @@
+/*
+ * Copyright (C) 2016 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.server.net;
+
+import static android.app.usage.NetworkStatsManager.MIN_THRESHOLD_BYTES;
+
+import android.app.usage.NetworkStatsManager;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.net.DataUsageRequest;
+import android.net.NetworkIdentitySet;
+import android.net.NetworkStack;
+import android.net.NetworkStats;
+import android.net.NetworkStatsAccess;
+import android.net.NetworkStatsCollection;
+import android.net.NetworkStatsHistory;
+import android.net.NetworkTemplate;
+import android.net.netstats.IUsageCallback;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.IBinder;
+import android.os.Looper;
+import android.os.Message;
+import android.os.Process;
+import android.os.RemoteException;
+import android.util.ArrayMap;
+import android.util.Log;
+import android.util.SparseArray;
+
+import com.android.internal.annotations.VisibleForTesting;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Manages observers of {@link NetworkStats}. Allows observers to be notified when
+ * data usage has been reported in {@link NetworkStatsService}. An observer can set
+ * a threshold of how much data it cares about to be notified.
+ */
+class NetworkStatsObservers {
+    private static final String TAG = "NetworkStatsObservers";
+    private static final boolean LOGV = false;
+
+    private static final int MSG_REGISTER = 1;
+    private static final int MSG_UNREGISTER = 2;
+    private static final int MSG_UPDATE_STATS = 3;
+
+    // All access to this map must be done from the handler thread.
+    // indexed by DataUsageRequest#requestId
+    private final SparseArray<RequestInfo> mDataUsageRequests = new SparseArray<>();
+
+    // Sequence number of DataUsageRequests
+    private final AtomicInteger mNextDataUsageRequestId = new AtomicInteger();
+
+    // Lazily instantiated when an observer is registered.
+    private volatile Handler mHandler;
+
+    /**
+     * Creates a wrapper that contains the caller context and a normalized request.
+     * The request should be returned to the caller app, and the wrapper should be sent to this
+     * object through #addObserver by the service handler.
+     *
+     * <p>It will register the observer asynchronously, so it is safe to call from any thread.
+     *
+     * @return the normalized request wrapped within {@link RequestInfo}.
+     */
+    public DataUsageRequest register(Context context, DataUsageRequest inputRequest,
+            IUsageCallback callback, int callingUid, @NetworkStatsAccess.Level int accessLevel) {
+        DataUsageRequest request = buildRequest(context, inputRequest, callingUid);
+        RequestInfo requestInfo = buildRequestInfo(request, callback, callingUid,
+                accessLevel);
+
+        if (LOGV) Log.v(TAG, "Registering observer for " + request);
+        getHandler().sendMessage(mHandler.obtainMessage(MSG_REGISTER, requestInfo));
+        return request;
+    }
+
+    /**
+     * Unregister a data usage observer.
+     *
+     * <p>It will unregister the observer asynchronously, so it is safe to call from any thread.
+     */
+    public void unregister(DataUsageRequest request, int callingUid) {
+        getHandler().sendMessage(mHandler.obtainMessage(MSG_UNREGISTER, callingUid, 0 /* ignore */,
+                request));
+    }
+
+    /**
+     * Updates data usage statistics of registered observers and notifies if limits are reached.
+     *
+     * <p>It will update stats asynchronously, so it is safe to call from any thread.
+     */
+    public void updateStats(NetworkStats xtSnapshot, NetworkStats uidSnapshot,
+                ArrayMap<String, NetworkIdentitySet> activeIfaces,
+                ArrayMap<String, NetworkIdentitySet> activeUidIfaces,
+                long currentTime) {
+        StatsContext statsContext = new StatsContext(xtSnapshot, uidSnapshot, activeIfaces,
+                activeUidIfaces, currentTime);
+        getHandler().sendMessage(mHandler.obtainMessage(MSG_UPDATE_STATS, statsContext));
+    }
+
+    private Handler getHandler() {
+        if (mHandler == null) {
+            synchronized (this) {
+                if (mHandler == null) {
+                    if (LOGV) Log.v(TAG, "Creating handler");
+                    mHandler = new Handler(getHandlerLooperLocked(), mHandlerCallback);
+                }
+            }
+        }
+        return mHandler;
+    }
+
+    @VisibleForTesting
+    protected Looper getHandlerLooperLocked() {
+        HandlerThread handlerThread = new HandlerThread(TAG);
+        handlerThread.start();
+        return handlerThread.getLooper();
+    }
+
+    private Handler.Callback mHandlerCallback = new Handler.Callback() {
+        @Override
+        public boolean handleMessage(Message msg) {
+            switch (msg.what) {
+                case MSG_REGISTER: {
+                    handleRegister((RequestInfo) msg.obj);
+                    return true;
+                }
+                case MSG_UNREGISTER: {
+                    handleUnregister((DataUsageRequest) msg.obj, msg.arg1 /* callingUid */);
+                    return true;
+                }
+                case MSG_UPDATE_STATS: {
+                    handleUpdateStats((StatsContext) msg.obj);
+                    return true;
+                }
+                default: {
+                    return false;
+                }
+            }
+        }
+    };
+
+    /**
+     * Adds a {@link RequestInfo} as an observer.
+     * Should only be called from the handler thread otherwise there will be a race condition
+     * on mDataUsageRequests.
+     */
+    private void handleRegister(RequestInfo requestInfo) {
+        mDataUsageRequests.put(requestInfo.mRequest.requestId, requestInfo);
+    }
+
+    /**
+     * Removes a {@link DataUsageRequest} if the calling uid is authorized.
+     * Should only be called from the handler thread otherwise there will be a race condition
+     * on mDataUsageRequests.
+     */
+    private void handleUnregister(DataUsageRequest request, int callingUid) {
+        RequestInfo requestInfo;
+        requestInfo = mDataUsageRequests.get(request.requestId);
+        if (requestInfo == null) {
+            if (LOGV) Log.v(TAG, "Trying to unregister unknown request " + request);
+            return;
+        }
+        if (Process.SYSTEM_UID != callingUid && requestInfo.mCallingUid != callingUid) {
+            Log.w(TAG, "Caller uid " + callingUid + " is not owner of " + request);
+            return;
+        }
+
+        if (LOGV) Log.v(TAG, "Unregistering " + request);
+        mDataUsageRequests.remove(request.requestId);
+        requestInfo.unlinkDeathRecipient();
+        requestInfo.callCallback(NetworkStatsManager.CALLBACK_RELEASED);
+    }
+
+    private void handleUpdateStats(StatsContext statsContext) {
+        if (mDataUsageRequests.size() == 0) {
+            return;
+        }
+
+        for (int i = 0; i < mDataUsageRequests.size(); i++) {
+            RequestInfo requestInfo = mDataUsageRequests.valueAt(i);
+            requestInfo.updateStats(statsContext);
+        }
+    }
+
+    private DataUsageRequest buildRequest(Context context, DataUsageRequest request,
+                int callingUid) {
+        // For non-NETWORK_STACK permission uid, cap the minimum threshold to a safe default to
+        // avoid too many callbacks.
+        final long thresholdInBytes = (context.checkPermission(
+                NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK, Process.myPid(), callingUid)
+                == PackageManager.PERMISSION_GRANTED ? request.thresholdInBytes
+                : Math.max(MIN_THRESHOLD_BYTES, request.thresholdInBytes));
+        if (thresholdInBytes > request.thresholdInBytes) {
+            Log.w(TAG, "Threshold was too low for " + request
+                    + ". Overriding to a safer default of " + thresholdInBytes + " bytes");
+        }
+        return new DataUsageRequest(mNextDataUsageRequestId.incrementAndGet(),
+                request.template, thresholdInBytes);
+    }
+
+    private RequestInfo buildRequestInfo(DataUsageRequest request, IUsageCallback callback,
+            int callingUid, @NetworkStatsAccess.Level int accessLevel) {
+        if (accessLevel <= NetworkStatsAccess.Level.USER) {
+            return new UserUsageRequestInfo(this, request, callback, callingUid,
+                    accessLevel);
+        } else {
+            // Safety check in case a new access level is added and we forgot to update this
+            if (accessLevel < NetworkStatsAccess.Level.DEVICESUMMARY) {
+                throw new IllegalArgumentException(
+                        "accessLevel " + accessLevel + " is less than DEVICESUMMARY.");
+            }
+            return new NetworkUsageRequestInfo(this, request, callback, callingUid,
+                    accessLevel);
+        }
+    }
+
+    /**
+     * Tracks information relevant to a data usage observer.
+     * It will notice when the calling process dies so we can self-expire.
+     */
+    private abstract static class RequestInfo implements IBinder.DeathRecipient {
+        private final NetworkStatsObservers mStatsObserver;
+        protected final DataUsageRequest mRequest;
+        private final IUsageCallback mCallback;
+        protected final int mCallingUid;
+        protected final @NetworkStatsAccess.Level int mAccessLevel;
+        protected NetworkStatsRecorder mRecorder;
+        protected NetworkStatsCollection mCollection;
+
+        RequestInfo(NetworkStatsObservers statsObserver, DataUsageRequest request,
+                IUsageCallback callback, int callingUid,
+                    @NetworkStatsAccess.Level int accessLevel) {
+            mStatsObserver = statsObserver;
+            mRequest = request;
+            mCallback = callback;
+            mCallingUid = callingUid;
+            mAccessLevel = accessLevel;
+
+            try {
+                mCallback.asBinder().linkToDeath(this, 0);
+            } catch (RemoteException e) {
+                binderDied();
+            }
+        }
+
+        @Override
+        public void binderDied() {
+            if (LOGV) {
+                Log.v(TAG, "RequestInfo binderDied(" + mRequest + ", " + mCallback + ")");
+            }
+            mStatsObserver.unregister(mRequest, Process.SYSTEM_UID);
+            callCallback(NetworkStatsManager.CALLBACK_RELEASED);
+        }
+
+        @Override
+        public String toString() {
+            return "RequestInfo from uid:" + mCallingUid
+                    + " for " + mRequest + " accessLevel:" + mAccessLevel;
+        }
+
+        private void unlinkDeathRecipient() {
+            mCallback.asBinder().unlinkToDeath(this, 0);
+        }
+
+        /**
+         * Update stats given the samples and interface to identity mappings.
+         */
+        private void updateStats(StatsContext statsContext) {
+            if (mRecorder == null) {
+                // First run; establish baseline stats
+                resetRecorder();
+                recordSample(statsContext);
+                return;
+            }
+            recordSample(statsContext);
+
+            if (checkStats()) {
+                resetRecorder();
+                callCallback(NetworkStatsManager.CALLBACK_LIMIT_REACHED);
+            }
+        }
+
+        private void callCallback(int callbackType) {
+            try {
+                if (LOGV) {
+                    Log.v(TAG, "sending notification " + callbackTypeToName(callbackType)
+                            + " for " + mRequest);
+                }
+                switch (callbackType) {
+                    case NetworkStatsManager.CALLBACK_LIMIT_REACHED:
+                        mCallback.onThresholdReached(mRequest);
+                        break;
+                    case NetworkStatsManager.CALLBACK_RELEASED:
+                        mCallback.onCallbackReleased(mRequest);
+                        break;
+                }
+            } catch (RemoteException e) {
+                // May occur naturally in the race of binder death.
+                Log.w(TAG, "RemoteException caught trying to send a callback msg for " + mRequest);
+            }
+        }
+
+        private void resetRecorder() {
+            mRecorder = new NetworkStatsRecorder();
+            mCollection = mRecorder.getSinceBoot();
+        }
+
+        protected abstract boolean checkStats();
+
+        protected abstract void recordSample(StatsContext statsContext);
+
+        private String callbackTypeToName(int callbackType) {
+            switch (callbackType) {
+                case NetworkStatsManager.CALLBACK_LIMIT_REACHED:
+                    return "LIMIT_REACHED";
+                case NetworkStatsManager.CALLBACK_RELEASED:
+                    return "RELEASED";
+                default:
+                    return "UNKNOWN";
+            }
+        }
+    }
+
+    private static class NetworkUsageRequestInfo extends RequestInfo {
+        NetworkUsageRequestInfo(NetworkStatsObservers statsObserver, DataUsageRequest request,
+                IUsageCallback callback, int callingUid,
+                    @NetworkStatsAccess.Level int accessLevel) {
+            super(statsObserver, request, callback, callingUid, accessLevel);
+        }
+
+        @Override
+        protected boolean checkStats() {
+            long bytesSoFar = getTotalBytesForNetwork(mRequest.template);
+            if (LOGV) {
+                Log.v(TAG, bytesSoFar + " bytes so far since notification for "
+                        + mRequest.template);
+            }
+            if (bytesSoFar > mRequest.thresholdInBytes) {
+                return true;
+            }
+            return false;
+        }
+
+        @Override
+        protected void recordSample(StatsContext statsContext) {
+            // Recorder does not need to be locked in this context since only the handler
+            // 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,
+                    statsContext.mCurrentTime);
+        }
+
+        /**
+         * Reads stats matching the given template. {@link NetworkStatsCollection} will aggregate
+         * over all buckets, which in this case should be only one since we built it big enough
+         * that it will outlive the caller. If it doesn't, then there will be multiple buckets.
+         */
+        private long getTotalBytesForNetwork(NetworkTemplate template) {
+            NetworkStats stats = mCollection.getSummary(template,
+                    Long.MIN_VALUE /* start */, Long.MAX_VALUE /* end */,
+                    mAccessLevel, mCallingUid);
+            return stats.getTotalBytes();
+        }
+    }
+
+    private static class UserUsageRequestInfo extends RequestInfo {
+        UserUsageRequestInfo(NetworkStatsObservers statsObserver, DataUsageRequest request,
+                    IUsageCallback callback, int callingUid,
+                    @NetworkStatsAccess.Level int accessLevel) {
+            super(statsObserver, request, callback, callingUid, accessLevel);
+        }
+
+        @Override
+        protected boolean checkStats() {
+            int[] uidsToMonitor = mCollection.getRelevantUids(mAccessLevel, mCallingUid);
+
+            for (int i = 0; i < uidsToMonitor.length; i++) {
+                long bytesSoFar = getTotalBytesForNetworkUid(mRequest.template, uidsToMonitor[i]);
+                if (bytesSoFar > mRequest.thresholdInBytes) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        @Override
+        protected void recordSample(StatsContext statsContext) {
+            // Recorder does not need to be locked in this context since only the handler
+            // thread will update it. We pass the VPN info so VPN traffic is reattributed to
+            // responsible apps.
+            mRecorder.recordSnapshotLocked(statsContext.mUidSnapshot, statsContext.mActiveUidIfaces,
+                    statsContext.mCurrentTime);
+        }
+
+        /**
+         * Reads all stats matching the given template and uid. Ther history will likely only
+         * contain one bucket per ident since we build it big enough that it will outlive the
+         * caller lifetime.
+         */
+        private long getTotalBytesForNetworkUid(NetworkTemplate template, int uid) {
+            try {
+                NetworkStatsHistory history = mCollection.getHistory(template, null, uid,
+                        NetworkStats.SET_ALL, NetworkStats.TAG_NONE,
+                        NetworkStatsHistory.FIELD_ALL,
+                        Long.MIN_VALUE /* start */, Long.MAX_VALUE /* end */,
+                        mAccessLevel, mCallingUid);
+                return history.getTotalBytes();
+            } catch (SecurityException e) {
+                if (LOGV) {
+                    Log.w(TAG, "CallerUid " + mCallingUid + " may have lost access to uid "
+                            + uid);
+                }
+                return 0;
+            }
+        }
+    }
+
+    private static class StatsContext {
+        NetworkStats mXtSnapshot;
+        NetworkStats mUidSnapshot;
+        ArrayMap<String, NetworkIdentitySet> mActiveIfaces;
+        ArrayMap<String, NetworkIdentitySet> mActiveUidIfaces;
+        long mCurrentTime;
+
+        StatsContext(NetworkStats xtSnapshot, NetworkStats uidSnapshot,
+                ArrayMap<String, NetworkIdentitySet> activeIfaces,
+                ArrayMap<String, NetworkIdentitySet> activeUidIfaces,
+                long currentTime) {
+            mXtSnapshot = xtSnapshot;
+            mUidSnapshot = uidSnapshot;
+            mActiveIfaces = activeIfaces;
+            mActiveUidIfaces = activeUidIfaces;
+            mCurrentTime = currentTime;
+        }
+    }
+}

service-t/src/com/android/server/net/NetworkStatsRecorder.java

@@ -0,0 +1,507 @@
+/*
+ * Copyright (C) 2012 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.server.net;
+
+import static android.net.NetworkStats.TAG_NONE;
+import static android.net.TrafficStats.KB_IN_BYTES;
+import static android.net.TrafficStats.MB_IN_BYTES;
+import static android.text.format.DateUtils.YEAR_IN_MILLIS;
+
+import android.net.NetworkIdentitySet;
+import android.net.NetworkStats;
+import android.net.NetworkStats.NonMonotonicObserver;
+import android.net.NetworkStatsAccess;
+import android.net.NetworkStatsCollection;
+import android.net.NetworkStatsHistory;
+import android.net.NetworkTemplate;
+import android.net.TrafficStats;
+import android.os.Binder;
+import android.os.DropBoxManager;
+import android.service.NetworkStatsRecorderProto;
+import android.util.IndentingPrintWriter;
+import android.util.Log;
+import android.util.proto.ProtoOutputStream;
+
+import com.android.internal.util.FileRotator;
+import com.android.net.module.util.NetworkStatsUtils;
+
+import libcore.io.IoUtils;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.PrintWriter;
+import java.lang.ref.WeakReference;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * Logic to record deltas between periodic {@link NetworkStats} snapshots into
+ * {@link NetworkStatsHistory} that belong to {@link NetworkStatsCollection}.
+ * Keeps pending changes in memory until they pass a specific threshold, in
+ * bytes. Uses {@link FileRotator} for persistence logic if present.
+ * <p>
+ * Not inherently thread safe.
+ */
+public class NetworkStatsRecorder {
+    private static final String TAG = "NetworkStatsRecorder";
+    private static final boolean LOGD = false;
+    private static final boolean LOGV = false;
+
+    private static final String TAG_NETSTATS_DUMP = "netstats_dump";
+
+    /** Dump before deleting in {@link #recoverFromWtf()}. */
+    private static final boolean DUMP_BEFORE_DELETE = true;
+
+    private final FileRotator mRotator;
+    private final NonMonotonicObserver<String> mObserver;
+    private final DropBoxManager mDropBox;
+    private final String mCookie;
+
+    private final long mBucketDuration;
+    private final boolean mOnlyTags;
+
+    private long mPersistThresholdBytes = 2 * MB_IN_BYTES;
+    private NetworkStats mLastSnapshot;
+
+    private final NetworkStatsCollection mPending;
+    private final NetworkStatsCollection mSinceBoot;
+
+    private final CombiningRewriter mPendingRewriter;
+
+    private WeakReference<NetworkStatsCollection> mComplete;
+
+    /**
+     * Non-persisted recorder, with only one bucket. Used by {@link NetworkStatsObservers}.
+     */
+    public NetworkStatsRecorder() {
+        mRotator = null;
+        mObserver = null;
+        mDropBox = null;
+        mCookie = null;
+
+        // set the bucket big enough to have all data in one bucket, but allow some
+        // slack to avoid overflow
+        mBucketDuration = YEAR_IN_MILLIS;
+        mOnlyTags = false;
+
+        mPending = null;
+        mSinceBoot = new NetworkStatsCollection(mBucketDuration);
+
+        mPendingRewriter = null;
+    }
+
+    /**
+     * Persisted recorder.
+     */
+    public NetworkStatsRecorder(FileRotator rotator, NonMonotonicObserver<String> observer,
+            DropBoxManager dropBox, String cookie, long bucketDuration, boolean onlyTags) {
+        mRotator = Objects.requireNonNull(rotator, "missing FileRotator");
+        mObserver = Objects.requireNonNull(observer, "missing NonMonotonicObserver");
+        mDropBox = Objects.requireNonNull(dropBox, "missing DropBoxManager");
+        mCookie = cookie;
+
+        mBucketDuration = bucketDuration;
+        mOnlyTags = onlyTags;
+
+        mPending = new NetworkStatsCollection(bucketDuration);
+        mSinceBoot = new NetworkStatsCollection(bucketDuration);
+
+        mPendingRewriter = new CombiningRewriter(mPending);
+    }
+
+    public void setPersistThreshold(long thresholdBytes) {
+        if (LOGV) Log.v(TAG, "setPersistThreshold() with " + thresholdBytes);
+        mPersistThresholdBytes = NetworkStatsUtils.constrain(
+                thresholdBytes, 1 * KB_IN_BYTES, 100 * MB_IN_BYTES);
+    }
+
+    public void resetLocked() {
+        mLastSnapshot = null;
+        if (mPending != null) {
+            mPending.reset();
+        }
+        if (mSinceBoot != null) {
+            mSinceBoot.reset();
+        }
+        if (mComplete != null) {
+            mComplete.clear();
+        }
+    }
+
+    public NetworkStats.Entry getTotalSinceBootLocked(NetworkTemplate template) {
+        return mSinceBoot.getSummary(template, Long.MIN_VALUE, Long.MAX_VALUE,
+                NetworkStatsAccess.Level.DEVICE, Binder.getCallingUid()).getTotal(null);
+    }
+
+    public NetworkStatsCollection getSinceBoot() {
+        return mSinceBoot;
+    }
+
+    /**
+     * Load complete history represented by {@link FileRotator}. Caches
+     * internally as a {@link WeakReference}, and updated with future
+     * {@link #recordSnapshotLocked(NetworkStats, Map, long)} snapshots as long
+     * as reference is valid.
+     */
+    public NetworkStatsCollection getOrLoadCompleteLocked() {
+        Objects.requireNonNull(mRotator, "missing FileRotator");
+        NetworkStatsCollection res = mComplete != null ? mComplete.get() : null;
+        if (res == null) {
+            res = loadLocked(Long.MIN_VALUE, Long.MAX_VALUE);
+            mComplete = new WeakReference<NetworkStatsCollection>(res);
+        }
+        return res;
+    }
+
+    public NetworkStatsCollection getOrLoadPartialLocked(long start, long end) {
+        Objects.requireNonNull(mRotator, "missing FileRotator");
+        NetworkStatsCollection res = mComplete != null ? mComplete.get() : null;
+        if (res == null) {
+            res = loadLocked(start, end);
+        }
+        return res;
+    }
+
+    private NetworkStatsCollection loadLocked(long start, long end) {
+        if (LOGD) Log.d(TAG, "loadLocked() reading from disk for " + mCookie);
+        final NetworkStatsCollection res = new NetworkStatsCollection(mBucketDuration);
+        try {
+            mRotator.readMatching(res, start, end);
+            res.recordCollection(mPending);
+        } catch (IOException e) {
+            Log.wtf(TAG, "problem completely reading network stats", e);
+            recoverFromWtf();
+        } catch (OutOfMemoryError e) {
+            Log.wtf(TAG, "problem completely reading network stats", e);
+            recoverFromWtf();
+        }
+        return res;
+    }
+
+    /**
+     * Record any delta that occurred since last {@link NetworkStats} snapshot, using the given
+     * {@link Map} to identify network interfaces. First snapshot is considered bootstrap, and is
+     * not counted as delta.
+     */
+    public void recordSnapshotLocked(NetworkStats snapshot,
+            Map<String, NetworkIdentitySet> ifaceIdent, long currentTimeMillis) {
+        final HashSet<String> unknownIfaces = new HashSet<>();
+
+        // skip recording when snapshot missing
+        if (snapshot == null) return;
+
+        // assume first snapshot is bootstrap and don't record
+        if (mLastSnapshot == null) {
+            mLastSnapshot = snapshot;
+            return;
+        }
+
+        final NetworkStatsCollection complete = mComplete != null ? mComplete.get() : null;
+
+        final NetworkStats delta = NetworkStats.subtract(
+                snapshot, mLastSnapshot, mObserver, mCookie);
+        final long end = currentTimeMillis;
+        final long start = end - delta.getElapsedRealtime();
+
+        NetworkStats.Entry entry = null;
+        for (int i = 0; i < delta.size(); i++) {
+            entry = delta.getValues(i, entry);
+
+            // As a last-ditch check, report any negative values and
+            // clamp them so recording below doesn't croak.
+            if (entry.isNegative()) {
+                if (mObserver != null) {
+                    mObserver.foundNonMonotonic(delta, i, mCookie);
+                }
+                entry.rxBytes = Math.max(entry.rxBytes, 0);
+                entry.rxPackets = Math.max(entry.rxPackets, 0);
+                entry.txBytes = Math.max(entry.txBytes, 0);
+                entry.txPackets = Math.max(entry.txPackets, 0);
+                entry.operations = Math.max(entry.operations, 0);
+            }
+
+            final NetworkIdentitySet ident = ifaceIdent.get(entry.iface);
+            if (ident == null) {
+                unknownIfaces.add(entry.iface);
+                continue;
+            }
+
+            // skip when no delta occurred
+            if (entry.isEmpty()) continue;
+
+            // only record tag data when requested
+            if ((entry.tag == TAG_NONE) != mOnlyTags) {
+                if (mPending != null) {
+                    mPending.recordData(ident, entry.uid, entry.set, entry.tag, start, end, entry);
+                }
+
+                // also record against boot stats when present
+                if (mSinceBoot != null) {
+                    mSinceBoot.recordData(ident, entry.uid, entry.set, entry.tag, start, end, entry);
+                }
+
+                // also record against complete dataset when present
+                if (complete != null) {
+                    complete.recordData(ident, entry.uid, entry.set, entry.tag, start, end, entry);
+                }
+            }
+        }
+
+        mLastSnapshot = snapshot;
+
+        if (LOGV && unknownIfaces.size() > 0) {
+            Log.w(TAG, "unknown interfaces " + unknownIfaces + ", ignoring those stats");
+        }
+    }
+
+    /**
+     * Consider persisting any pending deltas, if they are beyond
+     * {@link #mPersistThresholdBytes}.
+     */
+    public void maybePersistLocked(long currentTimeMillis) {
+        Objects.requireNonNull(mRotator, "missing FileRotator");
+        final long pendingBytes = mPending.getTotalBytes();
+        if (pendingBytes >= mPersistThresholdBytes) {
+            forcePersistLocked(currentTimeMillis);
+        } else {
+            mRotator.maybeRotate(currentTimeMillis);
+        }
+    }
+
+    /**
+     * Force persisting any pending deltas.
+     */
+    public void forcePersistLocked(long currentTimeMillis) {
+        Objects.requireNonNull(mRotator, "missing FileRotator");
+        if (mPending.isDirty()) {
+            if (LOGD) Log.d(TAG, "forcePersistLocked() writing for " + mCookie);
+            try {
+                mRotator.rewriteActive(mPendingRewriter, currentTimeMillis);
+                mRotator.maybeRotate(currentTimeMillis);
+                mPending.reset();
+            } catch (IOException e) {
+                Log.wtf(TAG, "problem persisting pending stats", e);
+                recoverFromWtf();
+            } catch (OutOfMemoryError e) {
+                Log.wtf(TAG, "problem persisting pending stats", e);
+                recoverFromWtf();
+            }
+        }
+    }
+
+    /**
+     * Remove the given UID from all {@link FileRotator} history, migrating it
+     * to {@link TrafficStats#UID_REMOVED}.
+     */
+    public void removeUidsLocked(int[] uids) {
+        if (mRotator != null) {
+            try {
+                // Rewrite all persisted data to migrate UID stats
+                mRotator.rewriteAll(new RemoveUidRewriter(mBucketDuration, uids));
+            } catch (IOException e) {
+                Log.wtf(TAG, "problem removing UIDs " + Arrays.toString(uids), e);
+                recoverFromWtf();
+            } catch (OutOfMemoryError e) {
+                Log.wtf(TAG, "problem removing UIDs " + Arrays.toString(uids), e);
+                recoverFromWtf();
+            }
+        }
+
+        // Remove any pending stats
+        if (mPending != null) {
+            mPending.removeUids(uids);
+        }
+        if (mSinceBoot != null) {
+            mSinceBoot.removeUids(uids);
+        }
+
+        // Clear UID from current stats snapshot
+        if (mLastSnapshot != null) {
+            mLastSnapshot.removeUids(uids);
+        }
+
+        final NetworkStatsCollection complete = mComplete != null ? mComplete.get() : null;
+        if (complete != null) {
+            complete.removeUids(uids);
+        }
+    }
+
+    /**
+     * Rewriter that will combine current {@link NetworkStatsCollection} values
+     * with anything read from disk, and write combined set to disk. Clears the
+     * original {@link NetworkStatsCollection} when finished writing.
+     */
+    private static class CombiningRewriter implements FileRotator.Rewriter {
+        private final NetworkStatsCollection mCollection;
+
+        public CombiningRewriter(NetworkStatsCollection collection) {
+            mCollection = Objects.requireNonNull(collection, "missing NetworkStatsCollection");
+        }
+
+        @Override
+        public void reset() {
+            // ignored
+        }
+
+        @Override
+        public void read(InputStream in) throws IOException {
+            mCollection.read(in);
+        }
+
+        @Override
+        public boolean shouldWrite() {
+            return true;
+        }
+
+        @Override
+        public void write(OutputStream out) throws IOException {
+            mCollection.write(out);
+            mCollection.reset();
+        }
+    }
+
+    /**
+     * Rewriter that will remove any {@link NetworkStatsHistory} attributed to
+     * the requested UID, only writing data back when modified.
+     */
+    public static class RemoveUidRewriter implements FileRotator.Rewriter {
+        private final NetworkStatsCollection mTemp;
+        private final int[] mUids;
+
+        public RemoveUidRewriter(long bucketDuration, int[] uids) {
+            mTemp = new NetworkStatsCollection(bucketDuration);
+            mUids = uids;
+        }
+
+        @Override
+        public void reset() {
+            mTemp.reset();
+        }
+
+        @Override
+        public void read(InputStream in) throws IOException {
+            mTemp.read(in);
+            mTemp.clearDirty();
+            mTemp.removeUids(mUids);
+        }
+
+        @Override
+        public boolean shouldWrite() {
+            return mTemp.isDirty();
+        }
+
+        @Override
+        public void write(OutputStream out) throws IOException {
+            mTemp.write(out);
+        }
+    }
+
+    public void importLegacyNetworkLocked(File file) throws IOException {
+        Objects.requireNonNull(mRotator, "missing FileRotator");
+
+        // legacy file still exists; start empty to avoid double importing
+        mRotator.deleteAll();
+
+        final NetworkStatsCollection collection = new NetworkStatsCollection(mBucketDuration);
+        collection.readLegacyNetwork(file);
+
+        final long startMillis = collection.getStartMillis();
+        final long endMillis = collection.getEndMillis();
+
+        if (!collection.isEmpty()) {
+            // process legacy data, creating active file at starting time, then
+            // using end time to possibly trigger rotation.
+            mRotator.rewriteActive(new CombiningRewriter(collection), startMillis);
+            mRotator.maybeRotate(endMillis);
+        }
+    }
+
+    public void importLegacyUidLocked(File file) throws IOException {
+        Objects.requireNonNull(mRotator, "missing FileRotator");
+
+        // legacy file still exists; start empty to avoid double importing
+        mRotator.deleteAll();
+
+        final NetworkStatsCollection collection = new NetworkStatsCollection(mBucketDuration);
+        collection.readLegacyUid(file, mOnlyTags);
+
+        final long startMillis = collection.getStartMillis();
+        final long endMillis = collection.getEndMillis();
+
+        if (!collection.isEmpty()) {
+            // process legacy data, creating active file at starting time, then
+            // using end time to possibly trigger rotation.
+            mRotator.rewriteActive(new CombiningRewriter(collection), startMillis);
+            mRotator.maybeRotate(endMillis);
+        }
+    }
+
+    public void dumpLocked(IndentingPrintWriter pw, boolean fullHistory) {
+        if (mPending != null) {
+            pw.print("Pending bytes: "); pw.println(mPending.getTotalBytes());
+        }
+        if (fullHistory) {
+            pw.println("Complete history:");
+            getOrLoadCompleteLocked().dump(pw);
+        } else {
+            pw.println("History since boot:");
+            mSinceBoot.dump(pw);
+        }
+    }
+
+    public void dumpDebugLocked(ProtoOutputStream proto, long tag) {
+        final long start = proto.start(tag);
+        if (mPending != null) {
+            proto.write(NetworkStatsRecorderProto.PENDING_TOTAL_BYTES,
+                    mPending.getTotalBytes());
+        }
+        getOrLoadCompleteLocked().dumpDebug(proto,
+                NetworkStatsRecorderProto.COMPLETE_HISTORY);
+        proto.end(start);
+    }
+
+    public void dumpCheckin(PrintWriter pw, long start, long end) {
+        // Only load and dump stats from the requested window
+        getOrLoadPartialLocked(start, end).dumpCheckin(pw, start, end);
+    }
+
+    /**
+     * Recover from {@link FileRotator} failure by dumping state to
+     * {@link DropBoxManager} and deleting contents.
+     */
+    private void recoverFromWtf() {
+        if (DUMP_BEFORE_DELETE) {
+            final ByteArrayOutputStream os = new ByteArrayOutputStream();
+            try {
+                mRotator.dumpAll(os);
+            } catch (IOException e) {
+                // ignore partial contents
+                os.reset();
+            } finally {
+                IoUtils.closeQuietly(os);
+            }
+            mDropBox.addData(TAG_NETSTATS_DUMP, os.toByteArray(), 0);
+        }
+
+        mRotator.deleteAll();
+    }
+}

service-t/src/com/android/server/net/NetworkStatsSubscriptionsMonitor.java

@@ -0,0 +1,246 @@
+/*
+ * 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.server.net;
+
+import static android.app.usage.NetworkStatsManager.NETWORK_TYPE_5G_NSA;
+import static android.app.usage.NetworkStatsManager.getCollapsedRatType;
+import static android.telephony.TelephonyDisplayInfo.OVERRIDE_NETWORK_TYPE_NR_ADVANCED;
+import static android.telephony.TelephonyDisplayInfo.OVERRIDE_NETWORK_TYPE_NR_NSA;
+import static android.telephony.TelephonyManager.NETWORK_TYPE_LTE;
+
+import android.annotation.NonNull;
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.os.Build;
+import android.telephony.SubscriptionManager;
+import android.telephony.TelephonyCallback;
+import android.telephony.TelephonyDisplayInfo;
+import android.telephony.TelephonyManager;
+import android.text.TextUtils;
+import android.util.Log;
+import android.util.Pair;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.net.module.util.CollectionUtils;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Executor;
+
+/**
+ * Helper class that watches for events that are triggered per subscription.
+ */
+@TargetApi(Build.VERSION_CODES.TIRAMISU)
+public class NetworkStatsSubscriptionsMonitor extends
+        SubscriptionManager.OnSubscriptionsChangedListener {
+
+    /**
+     * Interface that this monitor uses to delegate event handling to NetworkStatsService.
+     */
+    public interface Delegate {
+        /**
+         * Notify that the collapsed RAT type has been changed for any subscription. The method
+         * will also be triggered for any existing sub when start and stop monitoring.
+         *
+         * @param subscriberId IMSI of the subscription.
+         * @param collapsedRatType collapsed RAT type.
+         *                     @see android.app.usage.NetworkStatsManager#getCollapsedRatType(int).
+         */
+        void onCollapsedRatTypeChanged(@NonNull String subscriberId, int collapsedRatType);
+    }
+    private final Delegate mDelegate;
+
+    /**
+     * Receivers that watches for {@link TelephonyDisplayInfo} changes for each subscription, to
+     * monitor the transitioning between Radio Access Technology(RAT) types for each sub.
+     */
+    @NonNull
+    private final CopyOnWriteArrayList<RatTypeListener> mRatListeners =
+            new CopyOnWriteArrayList<>();
+
+    @NonNull
+    private final SubscriptionManager mSubscriptionManager;
+    @NonNull
+    private final TelephonyManager mTeleManager;
+
+    @NonNull
+    private final Executor mExecutor;
+
+    NetworkStatsSubscriptionsMonitor(@NonNull Context context,
+            @NonNull Executor executor, @NonNull Delegate delegate) {
+        super();
+        mSubscriptionManager = (SubscriptionManager) context.getSystemService(
+                Context.TELEPHONY_SUBSCRIPTION_SERVICE);
+        mTeleManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
+        mExecutor = executor;
+        mDelegate = delegate;
+    }
+
+    @Override
+    public void onSubscriptionsChanged() {
+        // Collect active subId list, hidden subId such as opportunistic subscriptions are
+        // also needed to track CBRS.
+        final List<Integer> newSubs = getActiveSubIdList(mSubscriptionManager);
+
+        // IMSI is needed for every newly added sub. Listener stores subscriberId into it to
+        // prevent binder call to telephony when querying RAT. Keep listener registration with empty
+        // IMSI is meaningless since the RAT type changed is ambiguous for multi-SIM if reported
+        // with empty IMSI. So filter the subs w/o a valid IMSI to prevent such registration.
+        final List<Pair<Integer, String>> filteredNewSubs = new ArrayList<>();
+        for (final int subId : newSubs) {
+            final String subscriberId =
+                    mTeleManager.createForSubscriptionId(subId).getSubscriberId();
+            if (!TextUtils.isEmpty(subscriberId)) {
+                filteredNewSubs.add(new Pair(subId, subscriberId));
+            }
+        }
+
+        for (final Pair<Integer, String> sub : filteredNewSubs) {
+            // Fully match listener with subId and IMSI, since in some rare cases, IMSI might be
+            // suddenly change regardless of subId, such as switch IMSI feature in modem side.
+            // If that happens, register new listener with new IMSI and remove old one later.
+            if (CollectionUtils.any(mRatListeners, it -> it.equalsKey(sub.first, sub.second))) {
+                continue;
+            }
+
+            final RatTypeListener listener = new RatTypeListener(this, sub.first, sub.second);
+            mRatListeners.add(listener);
+
+            // Register listener to the telephony manager that associated with specific sub.
+            mTeleManager.createForSubscriptionId(sub.first)
+                    .registerTelephonyCallback(mExecutor, listener);
+            Log.d(NetworkStatsService.TAG, "RAT type listener registered for sub " + sub.first);
+        }
+
+        for (final RatTypeListener listener : new ArrayList<>(mRatListeners)) {
+            // If there is no subId and IMSI matched the listener, removes it.
+            if (!CollectionUtils.any(filteredNewSubs,
+                    it -> listener.equalsKey(it.first, it.second))) {
+                handleRemoveRatTypeListener(listener);
+            }
+        }
+    }
+
+    @NonNull
+    private List<Integer> getActiveSubIdList(@NonNull SubscriptionManager subscriptionManager) {
+        final ArrayList<Integer> ret = new ArrayList<>();
+        final int[] ids = subscriptionManager.getCompleteActiveSubscriptionIdList();
+        for (int id : ids) ret.add(id);
+        return ret;
+    }
+
+    /**
+     * Get a collapsed RatType for the given subscriberId.
+     *
+     * @param subscriberId the target subscriberId
+     * @return collapsed RatType for the given subscriberId
+     */
+    public int getRatTypeForSubscriberId(@NonNull String subscriberId) {
+        final int index = CollectionUtils.indexOf(mRatListeners,
+                it -> TextUtils.equals(subscriberId, it.mSubscriberId));
+        return index != -1 ? mRatListeners.get(index).mLastCollapsedRatType
+                : TelephonyManager.NETWORK_TYPE_UNKNOWN;
+    }
+
+    /**
+     * Start monitoring events that triggered per subscription.
+     */
+    public void start() {
+        mSubscriptionManager.addOnSubscriptionsChangedListener(mExecutor, this);
+    }
+
+    /**
+     * Unregister subscription changes and all listeners for each subscription.
+     */
+    public void stop() {
+        mSubscriptionManager.removeOnSubscriptionsChangedListener(this);
+
+        for (final RatTypeListener listener : new ArrayList<>(mRatListeners)) {
+            handleRemoveRatTypeListener(listener);
+        }
+    }
+
+    private void handleRemoveRatTypeListener(@NonNull RatTypeListener listener) {
+        mTeleManager.createForSubscriptionId(listener.mSubId)
+                .unregisterTelephonyCallback(listener);
+        Log.d(NetworkStatsService.TAG, "RAT type listener unregistered for sub " + listener.mSubId);
+        mRatListeners.remove(listener);
+
+        // Removal of subscriptions doesn't generate RAT changed event, fire it for every
+        // RatTypeListener.
+        mDelegate.onCollapsedRatTypeChanged(
+                listener.mSubscriberId, TelephonyManager.NETWORK_TYPE_UNKNOWN);
+    }
+
+    static class RatTypeListener extends TelephonyCallback
+            implements TelephonyCallback.DisplayInfoListener {
+        // Unique id for the subscription. See {@link SubscriptionInfo#getSubscriptionId}.
+        @NonNull
+        private final int mSubId;
+
+        // IMSI to identifying the corresponding network from {@link NetworkState}.
+        // See {@link TelephonyManager#getSubscriberId}.
+        @NonNull
+        private final String mSubscriberId;
+
+        private volatile int mLastCollapsedRatType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
+        @NonNull
+        private final NetworkStatsSubscriptionsMonitor mMonitor;
+
+        RatTypeListener(@NonNull NetworkStatsSubscriptionsMonitor monitor, int subId,
+                @NonNull String subscriberId) {
+            mSubId = subId;
+            mSubscriberId = subscriberId;
+            mMonitor = monitor;
+        }
+
+        @Override
+        public void onDisplayInfoChanged(TelephonyDisplayInfo displayInfo) {
+            // In 5G SA (Stand Alone) mode, the primary cell itself will be 5G hence telephony
+            // would report RAT = 5G_NR.
+            // However, in 5G NSA (Non Stand Alone) mode, the primary cell is still LTE and
+            // network allocates a secondary 5G cell so telephony reports RAT = LTE along with
+            // NR state as connected. In such case, attributes the data usage to NR.
+            // See b/160727498.
+            final boolean is5GNsa = displayInfo.getNetworkType() == NETWORK_TYPE_LTE
+                    && (displayInfo.getOverrideNetworkType() == OVERRIDE_NETWORK_TYPE_NR_NSA
+                    || displayInfo.getOverrideNetworkType() == OVERRIDE_NETWORK_TYPE_NR_ADVANCED);
+
+            final int networkType =
+                    (is5GNsa ? NETWORK_TYPE_5G_NSA : displayInfo.getNetworkType());
+            final int collapsedRatType = getCollapsedRatType(networkType);
+            if (collapsedRatType == mLastCollapsedRatType) return;
+
+            if (NetworkStatsService.LOGD) {
+                Log.d(NetworkStatsService.TAG, "subtype changed for sub(" + mSubId + "): "
+                        + mLastCollapsedRatType + " -> " + collapsedRatType);
+            }
+            mLastCollapsedRatType = collapsedRatType;
+            mMonitor.mDelegate.onCollapsedRatTypeChanged(mSubscriberId, mLastCollapsedRatType);
+        }
+
+        @VisibleForTesting
+        public int getSubId() {
+            return mSubId;
+        }
+
+        boolean equalsKey(int subId, @NonNull String subscriberId) {
+            return mSubId == subId && TextUtils.equals(mSubscriberId, subscriberId);
+        }
+    }
+}

service-t/src/com/android/server/net/StatsMapKey.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * Key for both stats maps.
+ */
+public class StatsMapKey extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long uid;
+
+    @Field(order = 1, type = Type.U32)
+    public final long tag;
+
+    @Field(order = 2, type = Type.U32)
+    public final long counterSet;
+
+    @Field(order = 3, type = Type.U32)
+    public final long ifaceIndex;
+
+    public StatsMapKey(final long uid, final long tag, final long counterSet,
+            final long ifaceIndex) {
+        this.uid = uid;
+        this.tag = tag;
+        this.counterSet = counterSet;
+        this.ifaceIndex = ifaceIndex;
+    }
+}

service-t/src/com/android/server/net/StatsMapValue.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * Value used for both stats maps and uid stats map.
+ */
+public class StatsMapValue extends Struct {
+    @Field(order = 0, type = Type.U63)
+    public final long rxPackets;
+
+    @Field(order = 1, type = Type.U63)
+    public final long rxBytes;
+
+    @Field(order = 2, type = Type.U63)
+    public final long txPackets;
+
+    @Field(order = 3, type = Type.U63)
+    public final long txBytes;
+
+    public StatsMapValue(final long rxPackets, final long rxBytes, final long txPackets,
+            final long txBytes) {
+        this.rxPackets = rxPackets;
+        this.rxBytes = rxBytes;
+        this.txPackets = txPackets;
+        this.txBytes = txBytes;
+    }
+}

service-t/src/com/android/server/net/UidStatsMapKey.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2022 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.server.net;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+/**
+ * Key for uid stats map.
+ */
+public class UidStatsMapKey extends Struct {
+    @Field(order = 0, type = Type.U32)
+    public final long uid;
+
+    public UidStatsMapKey(final long uid) {
+        this.uid = uid;
+    }
+}