| /* |
| * 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.connectivity; |
| |
| import android.content.Context; |
| import android.net.ConnectivityMetricsEvent; |
| import android.net.IIpConnectivityMetrics; |
| import android.net.INetdEventCallback; |
| import android.net.metrics.ApfProgramEvent; |
| import android.net.metrics.IpConnectivityLog; |
| import android.os.Binder; |
| import android.os.IBinder; |
| import android.os.Parcelable; |
| import android.os.Process; |
| import android.provider.Settings; |
| import android.text.TextUtils; |
| import android.text.format.DateUtils; |
| import android.util.ArrayMap; |
| import android.util.Base64; |
| import android.util.Log; |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.TokenBucket; |
| import com.android.server.SystemService; |
| import java.io.FileDescriptor; |
| import java.io.IOException; |
| import java.io.PrintWriter; |
| import java.util.ArrayList; |
| import java.util.function.ToIntFunction; |
| |
| import static com.android.server.connectivity.metrics.IpConnectivityLogClass.IpConnectivityEvent; |
| |
| /** {@hide} */ |
| final public class IpConnectivityMetrics extends SystemService { |
| private static final String TAG = IpConnectivityMetrics.class.getSimpleName(); |
| private static final boolean DBG = false; |
| |
| // The logical version numbers of ipconnectivity.proto, corresponding to the |
| // "version" field of IpConnectivityLog. |
| private static final int NYC = 0; |
| private static final int NYC_MR1 = 1; |
| private static final int NYC_MR2 = 2; |
| public static final int VERSION = NYC_MR2; |
| |
| private static final String SERVICE_NAME = IpConnectivityLog.SERVICE_NAME; |
| |
| // Default size of the event buffer. Once the buffer is full, incoming events are dropped. |
| private static final int DEFAULT_BUFFER_SIZE = 2000; |
| // Maximum size of the event buffer. |
| private static final int MAXIMUM_BUFFER_SIZE = DEFAULT_BUFFER_SIZE * 10; |
| |
| private static final int ERROR_RATE_LIMITED = -1; |
| |
| // Lock ensuring that concurrent manipulations of the event buffer are correct. |
| // There are three concurrent operations to synchronize: |
| // - appending events to the buffer. |
| // - iterating throught the buffer. |
| // - flushing the buffer content and replacing it by a new buffer. |
| private final Object mLock = new Object(); |
| |
| @VisibleForTesting |
| public final Impl impl = new Impl(); |
| private NetdEventListenerService mNetdListener; |
| |
| @GuardedBy("mLock") |
| private ArrayList<ConnectivityMetricsEvent> mBuffer; |
| @GuardedBy("mLock") |
| private int mDropped; |
| @GuardedBy("mLock") |
| private int mCapacity; |
| @GuardedBy("mLock") |
| private final ArrayMap<Class<?>, TokenBucket> mBuckets = makeRateLimitingBuckets(); |
| |
| private final ToIntFunction<Context> mCapacityGetter; |
| |
| public IpConnectivityMetrics(Context ctx, ToIntFunction<Context> capacityGetter) { |
| super(ctx); |
| mCapacityGetter = capacityGetter; |
| initBuffer(); |
| } |
| |
| public IpConnectivityMetrics(Context ctx) { |
| this(ctx, READ_BUFFER_SIZE); |
| } |
| |
| @Override |
| public void onStart() { |
| if (DBG) Log.d(TAG, "onStart"); |
| } |
| |
| @Override |
| public void onBootPhase(int phase) { |
| if (phase == SystemService.PHASE_SYSTEM_SERVICES_READY) { |
| if (DBG) Log.d(TAG, "onBootPhase"); |
| mNetdListener = new NetdEventListenerService(getContext()); |
| |
| publishBinderService(SERVICE_NAME, impl); |
| publishBinderService(mNetdListener.SERVICE_NAME, mNetdListener); |
| } |
| } |
| |
| @VisibleForTesting |
| public int bufferCapacity() { |
| return mCapacityGetter.applyAsInt(getContext()); |
| } |
| |
| private void initBuffer() { |
| synchronized (mLock) { |
| mDropped = 0; |
| mCapacity = bufferCapacity(); |
| mBuffer = new ArrayList<>(mCapacity); |
| } |
| } |
| |
| private int append(ConnectivityMetricsEvent event) { |
| if (DBG) Log.d(TAG, "logEvent: " + event); |
| synchronized (mLock) { |
| final int left = mCapacity - mBuffer.size(); |
| if (event == null) { |
| return left; |
| } |
| if (isRateLimited(event)) { |
| // Do not count as a dropped event. TODO: consider adding separate counter |
| return ERROR_RATE_LIMITED; |
| } |
| if (left == 0) { |
| mDropped++; |
| return 0; |
| } |
| mBuffer.add(event); |
| return left - 1; |
| } |
| } |
| |
| private boolean isRateLimited(ConnectivityMetricsEvent event) { |
| TokenBucket tb = mBuckets.get(event.data.getClass()); |
| return (tb != null) && !tb.get(); |
| } |
| |
| private String flushEncodedOutput() { |
| final ArrayList<ConnectivityMetricsEvent> events; |
| final int dropped; |
| synchronized (mLock) { |
| events = mBuffer; |
| dropped = mDropped; |
| initBuffer(); |
| } |
| |
| final byte[] data; |
| try { |
| data = IpConnectivityEventBuilder.serialize(dropped, events); |
| } catch (IOException e) { |
| Log.e(TAG, "could not serialize events", e); |
| return ""; |
| } |
| |
| return Base64.encodeToString(data, Base64.DEFAULT); |
| } |
| |
| /** |
| * Clears the event buffer and prints its content as a protobuf serialized byte array |
| * inside a base64 encoded string. |
| */ |
| private void cmdFlush(FileDescriptor fd, PrintWriter pw, String[] args) { |
| pw.print(flushEncodedOutput()); |
| } |
| |
| /** |
| * Prints the content of the event buffer, either using the events ASCII representation |
| * or using protobuf text format. |
| */ |
| private void cmdList(FileDescriptor fd, PrintWriter pw, String[] args) { |
| final ArrayList<ConnectivityMetricsEvent> events; |
| synchronized (mLock) { |
| events = new ArrayList(mBuffer); |
| } |
| |
| if (args.length > 1 && args[1].equals("proto")) { |
| for (IpConnectivityEvent ev : IpConnectivityEventBuilder.toProto(events)) { |
| pw.print(ev.toString()); |
| } |
| return; |
| } |
| |
| for (ConnectivityMetricsEvent ev : events) { |
| pw.println(ev.toString()); |
| } |
| } |
| |
| private void cmdStats(FileDescriptor fd, PrintWriter pw, String[] args) { |
| synchronized (mLock) { |
| pw.println("Buffered events: " + mBuffer.size()); |
| pw.println("Buffer capacity: " + mCapacity); |
| pw.println("Dropped events: " + mDropped); |
| } |
| if (mNetdListener != null) { |
| mNetdListener.dump(pw); |
| } |
| } |
| |
| private void cmdDefault(FileDescriptor fd, PrintWriter pw, String[] args) { |
| if (args.length == 0) { |
| pw.println("No command"); |
| return; |
| } |
| pw.println("Unknown command " + TextUtils.join(" ", args)); |
| } |
| |
| public final class Impl extends IIpConnectivityMetrics.Stub { |
| static final String CMD_FLUSH = "flush"; |
| static final String CMD_LIST = "list"; |
| static final String CMD_STATS = "stats"; |
| static final String CMD_DUMPSYS = "-a"; // dumpsys.cpp dumps services with "-a" as arguments |
| static final String CMD_DEFAULT = CMD_STATS; |
| |
| @Override |
| public int logEvent(ConnectivityMetricsEvent event) { |
| enforceConnectivityInternalPermission(); |
| return append(event); |
| } |
| |
| @Override |
| public void dump(FileDescriptor fd, PrintWriter pw, String[] args) { |
| enforceDumpPermission(); |
| if (DBG) Log.d(TAG, "dumpsys " + TextUtils.join(" ", args)); |
| final String cmd = (args.length > 0) ? args[0] : CMD_DEFAULT; |
| switch (cmd) { |
| case CMD_FLUSH: |
| cmdFlush(fd, pw, args); |
| return; |
| case CMD_DUMPSYS: |
| // Fallthrough to CMD_LIST when dumpsys.cpp dumps services states (bug reports) |
| case CMD_LIST: |
| cmdList(fd, pw, args); |
| return; |
| case CMD_STATS: |
| cmdStats(fd, pw, args); |
| return; |
| default: |
| cmdDefault(fd, pw, args); |
| } |
| } |
| |
| private void enforceConnectivityInternalPermission() { |
| enforcePermission(android.Manifest.permission.CONNECTIVITY_INTERNAL); |
| } |
| |
| private void enforceDumpPermission() { |
| enforcePermission(android.Manifest.permission.DUMP); |
| } |
| |
| private void enforcePermission(String what) { |
| getContext().enforceCallingOrSelfPermission(what, "IpConnectivityMetrics"); |
| } |
| |
| private void enforceNetdEventListeningPermission() { |
| final int uid = Binder.getCallingUid(); |
| if (uid != Process.SYSTEM_UID) { |
| throw new SecurityException(String.format("Uid %d has no permission to listen for" |
| + " netd events.", uid)); |
| } |
| } |
| |
| @Override |
| public boolean registerNetdEventCallback(INetdEventCallback callback) { |
| enforceNetdEventListeningPermission(); |
| if (mNetdListener == null) { |
| return false; |
| } |
| return mNetdListener.registerNetdEventCallback(callback); |
| } |
| |
| @Override |
| public boolean unregisterNetdEventCallback() { |
| enforceNetdEventListeningPermission(); |
| if (mNetdListener == null) { |
| // if the service is null, we aren't registered anyway |
| return true; |
| } |
| return mNetdListener.unregisterNetdEventCallback(); |
| } |
| }; |
| |
| private static final ToIntFunction<Context> READ_BUFFER_SIZE = (ctx) -> { |
| int size = Settings.Global.getInt(ctx.getContentResolver(), |
| Settings.Global.CONNECTIVITY_METRICS_BUFFER_SIZE, DEFAULT_BUFFER_SIZE); |
| if (size <= 0) { |
| return DEFAULT_BUFFER_SIZE; |
| } |
| return Math.min(size, MAXIMUM_BUFFER_SIZE); |
| }; |
| |
| private static ArrayMap<Class<?>, TokenBucket> makeRateLimitingBuckets() { |
| ArrayMap<Class<?>, TokenBucket> map = new ArrayMap<>(); |
| // one token every minute, 50 tokens max: burst of ~50 events every hour. |
| map.put(ApfProgramEvent.class, new TokenBucket((int)DateUtils.MINUTE_IN_MILLIS, 50)); |
| return map; |
| } |
| } |