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      1 /*
      2  * Copyright (C) 2012 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 
     18 package com.android.server.location;
     19 
     20 import android.content.Context;
     21 import android.database.ContentObserver;
     22 import android.os.Handler;
     23 import android.os.UserHandle;
     24 import android.provider.Settings;
     25 import android.util.Log;
     26 import android.util.Slog;
     27 
     28 import com.android.server.LocationManagerService;
     29 
     30 import java.io.PrintWriter;
     31 import java.util.ArrayList;
     32 import java.util.Arrays;
     33 
     34 /**
     35  * Allows applications to be blacklisted from location updates at run-time.
     36  *
     37  * This is a silent blacklist. Applications can still call Location Manager
     38  * API's, but they just won't receive any locations.
     39  */
     40 public final class LocationBlacklist extends ContentObserver {
     41     private static final String TAG = "LocationBlacklist";
     42     private static final boolean D = LocationManagerService.D;
     43     private static final String BLACKLIST_CONFIG_NAME = "locationPackagePrefixBlacklist";
     44     private static final String WHITELIST_CONFIG_NAME = "locationPackagePrefixWhitelist";
     45 
     46     private final Context mContext;
     47     private final Object mLock = new Object();
     48 
     49     // all fields below synchronized on mLock
     50     private String[] mWhitelist = new String[0];
     51     private String[] mBlacklist = new String[0];
     52 
     53     private int mCurrentUserId = UserHandle.USER_SYSTEM;
     54 
     55     public LocationBlacklist(Context context, Handler handler) {
     56         super(handler);
     57         mContext = context;
     58     }
     59 
     60     public void init() {
     61         mContext.getContentResolver().registerContentObserver(Settings.Secure.getUriFor(
     62                 BLACKLIST_CONFIG_NAME), false, this, UserHandle.USER_ALL);
     63 //        mContext.getContentResolver().registerContentObserver(Settings.Secure.getUriFor(
     64 //                WHITELIST_CONFIG_NAME), false, this, UserHandle.USER_ALL);
     65         reloadBlacklist();
     66     }
     67 
     68     private void reloadBlacklistLocked() {
     69         mWhitelist = getStringArrayLocked(WHITELIST_CONFIG_NAME);
     70         if (D) Slog.d(TAG, "whitelist: " + Arrays.toString(mWhitelist));
     71         mBlacklist = getStringArrayLocked(BLACKLIST_CONFIG_NAME);
     72         if (D) Slog.d(TAG, "blacklist: " + Arrays.toString(mBlacklist));
     73     }
     74 
     75     private void reloadBlacklist() {
     76         synchronized (mLock) {
     77             reloadBlacklistLocked();
     78         }
     79     }
     80 
     81     /**
     82      * Return true if in blacklist
     83      * (package name matches blacklist, and does not match whitelist)
     84      */
     85     public boolean isBlacklisted(String packageName) {
     86         synchronized (mLock) {
     87             for (String black : mBlacklist) {
     88                 if (packageName.startsWith(black)) {
     89                     if (inWhitelist(packageName)) {
     90                         continue;
     91                     } else {
     92                         if (D) Log.d(TAG, "dropping location (blacklisted): "
     93                                 + packageName + " matches " + black);
     94                         return true;
     95                     }
     96                 }
     97             }
     98         }
     99         return false;
    100     }
    101 
    102     /**
    103      * Return true if any of packages are in whitelist
    104      */
    105     private boolean inWhitelist(String pkg) {
    106         synchronized (mLock) {
    107             for (String white : mWhitelist) {
    108                 if (pkg.startsWith(white)) return true;
    109             }
    110         }
    111         return false;
    112     }
    113 
    114     @Override
    115     public void onChange(boolean selfChange) {
    116         reloadBlacklist();
    117     }
    118 
    119     public void switchUser(int userId) {
    120         synchronized(mLock) {
    121             mCurrentUserId = userId;
    122             reloadBlacklistLocked();
    123         }
    124     }
    125 
    126     private String[] getStringArrayLocked(String key) {
    127         String flatString;
    128         synchronized(mLock) {
    129             flatString = Settings.Secure.getStringForUser(mContext.getContentResolver(), key,
    130                     mCurrentUserId);
    131         }
    132         if (flatString == null) {
    133             return new String[0];
    134         }
    135         String[] splitStrings = flatString.split(",");
    136         ArrayList<String> result = new ArrayList<String>();
    137         for (String pkg : splitStrings) {
    138             pkg = pkg.trim();
    139             if (pkg.isEmpty()) {
    140                 continue;
    141             }
    142             result.add(pkg);
    143         }
    144         return result.toArray(new String[result.size()]);
    145     }
    146 
    147     public void dump(PrintWriter pw) {
    148         pw.println("mWhitelist=" + Arrays.toString(mWhitelist) + " mBlacklist=" +
    149                 Arrays.toString(mBlacklist));
    150     }
    151 }
    152