HiddenApiLoggingApp/src/com/android/hiddenapiapp/Receiver.java

/*
 * Copyright (C) 2019 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.hiddenapiapp;

import android.app.StatsManager;
import android.app.StatsManager.StatsUnavailableException;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.provider.DeviceConfig;
import android.util.Log;
import java.util.Base64;

public class Receiver extends BroadcastReceiver {
  public static final String SET_RATE = "com.android.hiddenapiapp.SET_RATE";
  public static final String SET_CONFIG = "com.android.hiddenapiapp.SET_CONFIG";
  public static final String GET_DATA = "com.android.hiddenapiapp.GET_DATA";
  public static final String REMOVE_CONFIG = "com.android.hiddenapiapp.REMOVE_CONFIG";

  // ID of the config to be sent to statsd; this is an arbitrary value - but, obviously,
  // every config must have its own id (can be assigned either client or server side,
  // depending on use case)
  private static final long CONFIG_ID = 54321;
  private static final String TAG = "HiddenApiLogging";

  @Override
  public void onReceive(Context context, Intent intent) {
    StatsManager statsManager = (StatsManager) context.getSystemService(StatsManager.class);
    switch (intent.getAction()) {
      case SET_RATE:
        setLogRate(intent.getIntExtra("rate", 0));
        setResult(1, null, null);
        break;
      case SET_CONFIG:
        String config = intent.getStringExtra("config");
        if (setupConfig(Base64.getDecoder().decode(config), statsManager)) {
          setResult(1, null, null);
        } else {
          setResult(2, null, null);
        }
      case GET_DATA:
        // This is for demo purposes only; in real applications, this data would be accumulated
        // periodically in a buffer, and sent when the buffer fills up or otherwise convenient
        setResult(1, Base64.getEncoder().encodeToString(getData(statsManager)), null);
        break;
      case REMOVE_CONFIG:
        if (removeConfig(statsManager)) {
          setResult(1, null, null);
        } else {
          setResult(2, null, null);
        }
      default:
        setResult(2, null, null);
    }
  }

  private void setLogRate(int rate) {
    DeviceConfig.setProperty(
        "app_compat",
        "hidden_api_access_statslog_sampling_rate",
        new Integer(rate).toString(),
        false);
  }

  private boolean setupConfig(byte[] config, StatsManager statsManager) {
    if (statsManager == null) {
      return false;
    }
    try {
      statsManager.addConfig(CONFIG_ID, config);
      return true;
    } catch (StatsUnavailableException e) {
      Log.d(TAG, "Failed to send config to statsd");
      return false;
    }
  }

  private byte[] getData(StatsManager statsManager) {
    if (statsManager == null) {
      return null;
    }
    try {
      return statsManager.getReports(CONFIG_ID);
    } catch (StatsUnavailableException e) {
      return null;
    }
  }

  private boolean removeConfig(StatsManager statsManager) {
    if (statsManager == null) {
      return false;
    }
    try {
      statsManager.removeConfig(CONFIG_ID);
      statsManager = null;
      return true;
    } catch (StatsUnavailableException e) {
      Log.d(TAG, "Failed to remove config from statsd");
      return false;
    }
  }
}