1 /*
2  * Copyright (C) 2014 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 package android.net;
18 
19 import android.Manifest;
20 import android.annotation.SdkConstant;
21 import android.annotation.SdkConstant.SdkConstantType;
22 import android.annotation.SystemApi;
23 import android.content.Context;
24 import android.content.Intent;
25 import android.net.NetworkScorerAppManager.NetworkScorerAppData;
26 import android.os.IBinder;
27 import android.os.RemoteException;
28 import android.os.ServiceManager;
29 import android.os.UserHandle;
30 
31 /**
32  * Class that manages communication between network subsystems and a network scorer.
33  *
34  * <p>You can get an instance of this class by calling
35  * {@link android.content.Context#getSystemService(String)}:
36  *
37  * <pre>NetworkScoreManager manager =
38  *     (NetworkScoreManager) getSystemService(Context.NETWORK_SCORE_SERVICE)</pre>
39  *
40  * <p>A network scorer is any application which:
41  * <ul>
42  * <li>Declares the {@link android.Manifest.permission#SCORE_NETWORKS} permission.
43  * <li>Includes a receiver for {@link #ACTION_SCORE_NETWORKS} guarded by the
44  *     {@link android.Manifest.permission#BROADCAST_NETWORK_PRIVILEGED} permission which scores
45  *     networks and (eventually) calls {@link #updateScores} with the results. If this receiver
46  *     specifies an android:label attribute, this label will be used when referring to the
47  *     application throughout system settings; otherwise, the application label will be used.
48  * </ul>
49  *
50  * <p>The system keeps track of an active scorer application; at any time, only this application
51  * will receive {@link #ACTION_SCORE_NETWORKS} broadcasts and will be permitted to call
52  * {@link #updateScores}. Applications may determine the current active scorer with
53  * {@link #getActiveScorerPackage()} and request to change the active scorer by sending an
54  * {@link #ACTION_CHANGE_ACTIVE} broadcast with another scorer.
55  *
56  * @hide
57  */
58 @SystemApi
59 public class NetworkScoreManager {
60     /**
61      * Activity action: ask the user to change the active network scorer. This will show a dialog
62      * that asks the user whether they want to replace the current active scorer with the one
63      * specified in {@link #EXTRA_PACKAGE_NAME}. The activity will finish with RESULT_OK if the
64      * active scorer was changed or RESULT_CANCELED if it failed for any reason.
65      */
66     @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
67     public static final String ACTION_CHANGE_ACTIVE = "android.net.scoring.CHANGE_ACTIVE";
68 
69     /**
70      * Extra used with {@link #ACTION_CHANGE_ACTIVE} to specify the new scorer package. Set with
71      * {@link android.content.Intent#putExtra(String, String)}.
72      */
73     public static final String EXTRA_PACKAGE_NAME = "packageName";
74 
75     /**
76      * Broadcast action: new network scores are being requested. This intent will only be delivered
77      * to the current active scorer app. That app is responsible for scoring the networks and
78      * calling {@link #updateScores} when complete. The networks to score are specified in
79      * {@link #EXTRA_NETWORKS_TO_SCORE}, and will generally consist of all networks which have been
80      * configured by the user as well as any open networks.
81      *
82      * <p class="note">This is a protected intent that can only be sent by the system.
83      */
84     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
85     public static final String ACTION_SCORE_NETWORKS = "android.net.scoring.SCORE_NETWORKS";
86 
87     /**
88      * Extra used with {@link #ACTION_SCORE_NETWORKS} to specify the networks to be scored, as an
89      * array of {@link NetworkKey}s. Can be obtained with
90      * {@link android.content.Intent#getParcelableArrayExtra(String)}}.
91      */
92     public static final String EXTRA_NETWORKS_TO_SCORE = "networksToScore";
93 
94     /**
95      * Activity action: launch a custom activity for configuring a scorer before enabling it.
96      * Scorer applications may choose to specify an activity for this action, in which case the
97      * framework will launch that activity which should return RESULT_OK if scoring was enabled.
98      *
99      * <p>If no activity is included in a scorer which implements this action, the system dialog for
100      * selecting a scorer will be shown instead.
101      */
102     @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
103     public static final String ACTION_CUSTOM_ENABLE = "android.net.scoring.CUSTOM_ENABLE";
104 
105     /**
106      * Broadcast action: the active scorer has been changed. Scorer apps may listen to this to
107      * perform initialization once selected as the active scorer, or clean up unneeded resources
108      * if another scorer has been selected. This is an explicit broadcast only sent to the
109      * previous scorer and new scorer. Note that it is unnecessary to clear existing scores as
110      * this is handled by the system.
111      *
112      * <p>The new scorer will be specified in {@link #EXTRA_NEW_SCORER}.
113      *
114      * <p class="note">This is a protected intent that can only be sent by the system.
115      */
116     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
117     public static final String ACTION_SCORER_CHANGED = "android.net.scoring.SCORER_CHANGED";
118 
119     /**
120      * Extra used with {@link #ACTION_SCORER_CHANGED} to specify the newly selected scorer's package
121      * name. Will be null if scoring was disabled. Can be obtained with
122      * {@link android.content.Intent#getStringExtra(String)}.
123      */
124     public static final String EXTRA_NEW_SCORER = "newScorer";
125 
126     private final Context mContext;
127     private final INetworkScoreService mService;
128 
129     /** @hide */
NetworkScoreManager(Context context)130     public NetworkScoreManager(Context context) {
131         mContext = context;
132         IBinder iBinder = ServiceManager.getService(Context.NETWORK_SCORE_SERVICE);
133         mService = INetworkScoreService.Stub.asInterface(iBinder);
134     }
135 
136     /**
137      * Obtain the package name of the current active network scorer.
138      *
139      * <p>At any time, only one scorer application will receive {@link #ACTION_SCORE_NETWORKS}
140      * broadcasts and be allowed to call {@link #updateScores}. Applications may use this method to
141      * determine the current scorer and offer the user the ability to select a different scorer via
142      * the {@link #ACTION_CHANGE_ACTIVE} intent.
143      * @return the full package name of the current active scorer, or null if there is no active
144      *         scorer.
145      */
getActiveScorerPackage()146     public String getActiveScorerPackage() {
147         NetworkScorerAppData app = NetworkScorerAppManager.getActiveScorer(mContext);
148         if (app == null) {
149             return null;
150         }
151         return app.mPackageName;
152     }
153 
154     /**
155      * Update network scores.
156      *
157      * <p>This may be called at any time to re-score active networks. Scores will generally be
158      * updated quickly, but if this method is called too frequently, the scores may be held and
159      * applied at a later time.
160      *
161      * @param networks the networks which have been scored by the scorer.
162      * @return whether the update was successful.
163      * @throws SecurityException if the caller is not the active scorer.
164      */
updateScores(ScoredNetwork[] networks)165     public boolean updateScores(ScoredNetwork[] networks) throws SecurityException {
166         try {
167             return mService.updateScores(networks);
168         } catch (RemoteException e) {
169             throw e.rethrowFromSystemServer();
170         }
171     }
172 
173     /**
174      * Clear network scores.
175      *
176      * <p>Should be called when all scores need to be invalidated, i.e. because the scoring
177      * algorithm has changed and old scores can no longer be compared to future scores.
178      *
179      * <p>Note that scores will be cleared automatically when the active scorer changes, as scores
180      * from one scorer cannot be compared to those from another scorer.
181      *
182      * @return whether the clear was successful.
183      * @throws SecurityException if the caller is not the active scorer or privileged.
184      */
clearScores()185     public boolean clearScores() throws SecurityException {
186         try {
187             return mService.clearScores();
188         } catch (RemoteException e) {
189             throw e.rethrowFromSystemServer();
190         }
191     }
192 
193     /**
194      * Set the active scorer to a new package and clear existing scores.
195      *
196      * <p>Should never be called directly without obtaining user consent. This can be done by using
197      * the {@link #ACTION_CHANGE_ACTIVE} broadcast, or using a custom configuration activity.
198      *
199      * @return true if the operation succeeded, or false if the new package is not a valid scorer.
200      * @throws SecurityException if the caller does not hold the
201      *         {@link android.Manifest.permission#SCORE_NETWORKS} permission.
202      * @hide
203      */
204     @SystemApi
setActiveScorer(String packageName)205     public boolean setActiveScorer(String packageName) throws SecurityException {
206         try {
207             return mService.setActiveScorer(packageName);
208         } catch (RemoteException e) {
209             throw e.rethrowFromSystemServer();
210         }
211     }
212 
213     /**
214      * Turn off network scoring.
215      *
216      * <p>May only be called by the current scorer app, or the system.
217      *
218      * @throws SecurityException if the caller is neither the active scorer nor the system.
219      */
disableScoring()220     public void disableScoring() throws SecurityException {
221         try {
222             mService.disableScoring();
223         } catch (RemoteException e) {
224             throw e.rethrowFromSystemServer();
225         }
226     }
227 
228     /**
229      * Request scoring for networks.
230      *
231      * <p>Note that this is just a helper method to assemble the broadcast, and will run in the
232      * calling process.
233      *
234      * @return true if the broadcast was sent, or false if there is no active scorer.
235      * @throws SecurityException if the caller does not hold the
236      *         {@link android.Manifest.permission#BROADCAST_NETWORK_PRIVILEGED} permission.
237      * @hide
238      */
requestScores(NetworkKey[] networks)239     public boolean requestScores(NetworkKey[] networks) throws SecurityException {
240         String activeScorer = getActiveScorerPackage();
241         if (activeScorer == null) {
242             return false;
243         }
244         Intent intent = new Intent(ACTION_SCORE_NETWORKS);
245         intent.setPackage(activeScorer);
246         intent.setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
247         intent.putExtra(EXTRA_NETWORKS_TO_SCORE, networks);
248         // A scorer should never become active if its package doesn't hold SCORE_NETWORKS, but
249         // ensure the package still holds it to be extra safe.
250         // TODO: http://b/23422763
251         mContext.sendBroadcastAsUser(intent, UserHandle.SYSTEM, Manifest.permission.SCORE_NETWORKS);
252         return true;
253     }
254 
255     /**
256      * Register a network score cache.
257      *
258      * @param networkType the type of network this cache can handle. See {@link NetworkKey#type}.
259      * @param scoreCache implementation of {@link INetworkScoreCache} to store the scores.
260      * @throws SecurityException if the caller does not hold the
261      *         {@link android.Manifest.permission#BROADCAST_NETWORK_PRIVILEGED} permission.
262      * @throws IllegalArgumentException if a score cache is already registered for this type.
263      * @hide
264      */
registerNetworkScoreCache(int networkType, INetworkScoreCache scoreCache)265     public void registerNetworkScoreCache(int networkType, INetworkScoreCache scoreCache) {
266         try {
267             mService.registerNetworkScoreCache(networkType, scoreCache);
268         } catch (RemoteException e) {
269             throw e.rethrowFromSystemServer();
270         }
271     }
272 }
273