1 /*
2  * Copyright (C) 2017 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 package android.app.slice;
17 
18 import static android.app.slice.Slice.SUBTYPE_COLOR;
19 
20 import android.annotation.NonNull;
21 import android.app.PendingIntent;
22 import android.content.ComponentName;
23 import android.content.ContentProvider;
24 import android.content.ContentResolver;
25 import android.content.ContentValues;
26 import android.content.Context;
27 import android.content.Intent;
28 import android.content.IntentFilter;
29 import android.content.pm.PackageManager;
30 import android.content.pm.PackageManager.NameNotFoundException;
31 import android.content.pm.ProviderInfo;
32 import android.database.ContentObserver;
33 import android.database.Cursor;
34 import android.graphics.drawable.Icon;
35 import android.net.Uri;
36 import android.os.Binder;
37 import android.os.Bundle;
38 import android.os.CancellationSignal;
39 import android.os.Handler;
40 import android.os.Process;
41 import android.os.StrictMode;
42 import android.os.StrictMode.ThreadPolicy;
43 import android.util.ArraySet;
44 import android.util.Log;
45 import android.util.TypedValue;
46 import android.view.ContextThemeWrapper;
47 
48 import java.util.ArrayList;
49 import java.util.Arrays;
50 import java.util.Collection;
51 import java.util.Collections;
52 import java.util.List;
53 import java.util.Set;
54 
55 /**
56  * A SliceProvider allows an app to provide content to be displayed in system spaces. This content
57  * is templated and can contain actions, and the behavior of how it is surfaced is specific to the
58  * system surface.
59  * <p>
60  * Slices are not currently live content. They are bound once and shown to the user. If the content
61  * changes due to a callback from user interaction, then
62  * {@link ContentResolver#notifyChange(Uri, ContentObserver)} should be used to notify the system.
63  * </p>
64  * <p>
65  * The provider needs to be declared in the manifest to provide the authority for the app. The
66  * authority for most slices is expected to match the package of the application.
67  * </p>
68  *
69  * <pre class="prettyprint">
70  * {@literal
71  * <provider
72  *     android:name="com.example.mypkg.MySliceProvider"
73  *     android:authorities="com.example.mypkg" />}
74  * </pre>
75  * <p>
76  * Slices can be identified by a Uri or by an Intent. To link an Intent with a slice, the provider
77  * must have an {@link IntentFilter} matching the slice intent. When a slice is being requested via
78  * an intent, {@link #onMapIntentToUri(Intent)} can be called and is expected to return an
79  * appropriate Uri representing the slice.
80  *
81  * <pre class="prettyprint">
82  * {@literal
83  * <provider
84  *     android:name="com.example.mypkg.MySliceProvider"
85  *     android:authorities="com.example.mypkg">
86  *     <intent-filter>
87  *         <action android:name="com.example.mypkg.intent.action.MY_SLICE_INTENT" />
88  *         <category android:name="android.app.slice.category.SLICE" />
89  *     </intent-filter>
90  * </provider>}
91  * </pre>
92  *
93  * @see Slice
94  * @deprecated Slice framework has been deprecated, it will not receive any updates from
95  *          {@link android.os.Build.VANILLA_ICE_CREAM} and forward. If you are looking for a
96  *          framework that sends displayable data from one app to another, consider using
97  *          {@link android.app.appsearch.AppSearchManager}.
98  */
99 @Deprecated
100 public abstract class SliceProvider extends ContentProvider {
101     /**
102      * This is the Android platform's MIME type for a URI
103      * containing a slice implemented through {@link SliceProvider}.
104      */
105     public static final String SLICE_TYPE = "vnd.android.slice";
106 
107     private static final String TAG = "SliceProvider";
108     /**
109      * @hide
110      */
111     public static final String EXTRA_BIND_URI = "slice_uri";
112     /**
113      * @hide
114      */
115     public static final String EXTRA_SUPPORTED_SPECS = "supported_specs";
116     /**
117      * @hide
118      */
119     public static final String METHOD_SLICE = "bind_slice";
120     /**
121      * @hide
122      */
123     public static final String METHOD_MAP_INTENT = "map_slice";
124     /**
125      * @hide
126      */
127     public static final String METHOD_MAP_ONLY_INTENT = "map_only";
128     /**
129      * @hide
130      */
131     public static final String METHOD_PIN = "pin";
132     /**
133      * @hide
134      */
135     public static final String METHOD_UNPIN = "unpin";
136     /**
137      * @hide
138      */
139     public static final String METHOD_GET_DESCENDANTS = "get_descendants";
140     /**
141      * @hide
142      */
143     public static final String METHOD_GET_PERMISSIONS = "get_permissions";
144     /**
145      * @hide
146      */
147     public static final String EXTRA_INTENT = "slice_intent";
148     /**
149      * @hide
150      */
151     public static final String EXTRA_SLICE = "slice";
152     /**
153      * @hide
154      */
155     public static final String EXTRA_SLICE_DESCENDANTS = "slice_descendants";
156     /**
157      * @hide
158      */
159     public static final String EXTRA_PKG = "pkg";
160     /**
161      * @hide
162      */
163     public static final String EXTRA_RESULT = "result";
164 
165     private static final boolean DEBUG = false;
166 
167     private static final long SLICE_BIND_ANR = 2000;
168     private final String[] mAutoGrantPermissions;
169 
170     private String mCallback;
171     private SliceManager mSliceManager;
172 
173     /**
174      * A version of constructing a SliceProvider that allows autogranting slice permissions
175      * to apps that hold specific platform permissions.
176      * <p>
177      * When an app tries to bind a slice from this provider that it does not have access to,
178      * This provider will check if the caller holds permissions to any of the autoGrantPermissions
179      * specified, if they do they will be granted persisted uri access to all slices of this
180      * provider.
181      *
182      * @param autoGrantPermissions List of permissions that holders are auto-granted access
183      *                             to slices.
184      */
SliceProvider(@onNull String... autoGrantPermissions)185     public SliceProvider(@NonNull String... autoGrantPermissions) {
186         mAutoGrantPermissions = autoGrantPermissions;
187     }
188 
SliceProvider()189     public SliceProvider() {
190         mAutoGrantPermissions = new String[0];
191     }
192 
193     @Override
attachInfo(Context context, ProviderInfo info)194     public void attachInfo(Context context, ProviderInfo info) {
195         super.attachInfo(context, info);
196         mSliceManager = context.getSystemService(SliceManager.class);
197     }
198 
199     /**
200      * Implemented to create a slice.
201      * <p>
202      * onBindSlice should return as quickly as possible so that the UI tied
203      * to this slice can be responsive. No network or other IO will be allowed
204      * during onBindSlice. Any loading that needs to be done should happen
205      * in the background with a call to {@link ContentResolver#notifyChange(Uri, ContentObserver)}
206      * when the app is ready to provide the complete data in onBindSlice.
207      * <p>
208      * The slice returned should have a spec that is compatible with one of
209      * the supported specs.
210      *
211      * @param sliceUri Uri to bind.
212      * @param supportedSpecs List of supported specs.
213      * @see Slice
214      * @see Slice#HINT_PARTIAL
215      */
onBindSlice(Uri sliceUri, Set<SliceSpec> supportedSpecs)216     public Slice onBindSlice(Uri sliceUri, Set<SliceSpec> supportedSpecs) {
217         return null;
218     }
219 
220     /**
221      * Called to inform an app that a slice has been pinned.
222      * <p>
223      * Pinning is a way that slice hosts use to notify apps of which slices
224      * they care about updates for. When a slice is pinned the content is
225      * expected to be relatively fresh and kept up to date.
226      * <p>
227      * Being pinned does not provide any escalated privileges for the slice
228      * provider. So apps should do things such as turn on syncing or schedule
229      * a job in response to a onSlicePinned.
230      * <p>
231      * Pinned state is not persisted through a reboot, and apps can expect a
232      * new call to onSlicePinned for any slices that should remain pinned
233      * after a reboot occurs.
234      *
235      * @param sliceUri The uri of the slice being unpinned.
236      * @see #onSliceUnpinned(Uri)
237      */
onSlicePinned(Uri sliceUri)238     public void onSlicePinned(Uri sliceUri) {
239     }
240 
241     /**
242      * Called to inform an app that a slices is no longer pinned.
243      * <p>
244      * This means that no other apps on the device care about updates to this
245      * slice anymore and therefore it is not important to be updated. Any syncs
246      * or jobs related to this slice should be cancelled.
247      * @see #onSlicePinned(Uri)
248      */
onSliceUnpinned(Uri sliceUri)249     public void onSliceUnpinned(Uri sliceUri) {
250     }
251 
252     /**
253      * Obtains a list of slices that are descendants of the specified Uri.
254      * <p>
255      * Implementing this is optional for a SliceProvider, but does provide a good
256      * discovery mechanism for finding slice Uris.
257      *
258      * @param uri The uri to look for descendants under.
259      * @return All slices within the space.
260      * @see SliceManager#getSliceDescendants(Uri)
261      */
onGetSliceDescendants(@onNull Uri uri)262     public @NonNull Collection<Uri> onGetSliceDescendants(@NonNull Uri uri) {
263         return Collections.emptyList();
264     }
265 
266     /**
267      * This method must be overridden if an {@link IntentFilter} is specified on the SliceProvider.
268      * In that case, this method can be called and is expected to return a non-null Uri representing
269      * a slice. Otherwise this will throw {@link UnsupportedOperationException}.
270      *
271      * Any intent filter added to a slice provider should also contain
272      * {@link SliceManager#CATEGORY_SLICE}, because otherwise it will not be detected by
273      * {@link SliceManager#mapIntentToUri(Intent)}.
274      *
275      * @return Uri representing the slice associated with the provided intent.
276      * @see Slice
277      * @see SliceManager#mapIntentToUri(Intent)
278      */
onMapIntentToUri(Intent intent)279     public @NonNull Uri onMapIntentToUri(Intent intent) {
280         throw new UnsupportedOperationException(
281                 "This provider has not implemented intent to uri mapping");
282     }
283 
284     /**
285      * Called when an app requests a slice it does not have write permission
286      * to the uri for.
287      * <p>
288      * The return value will be the action on a slice that prompts the user that
289      * the calling app wants to show slices from this app. The default implementation
290      * launches a dialog that allows the user to grant access to this slice. Apps
291      * that do not want to allow this user grant, can override this and instead
292      * launch their own dialog with different behavior.
293      *
294      * @param sliceUri the Uri of the slice attempting to be bound.
295      * @see #getCallingPackage()
296      */
onCreatePermissionRequest(Uri sliceUri)297     public @NonNull PendingIntent onCreatePermissionRequest(Uri sliceUri) {
298         return createPermissionPendingIntent(getContext(), sliceUri, getCallingPackage());
299     }
300 
301     @Override
update(Uri uri, ContentValues values, String selection, String[] selectionArgs)302     public final int update(Uri uri, ContentValues values, String selection,
303             String[] selectionArgs) {
304         if (DEBUG) Log.d(TAG, "update " + uri);
305         return 0;
306     }
307 
308     @Override
delete(Uri uri, String selection, String[] selectionArgs)309     public final int delete(Uri uri, String selection, String[] selectionArgs) {
310         if (DEBUG) Log.d(TAG, "delete " + uri);
311         return 0;
312     }
313 
314     @Override
query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)315     public final Cursor query(Uri uri, String[] projection, String selection,
316             String[] selectionArgs, String sortOrder) {
317         if (DEBUG) Log.d(TAG, "query " + uri);
318         return null;
319     }
320 
321     @Override
query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder, CancellationSignal cancellationSignal)322     public final Cursor query(Uri uri, String[] projection, String selection, String[]
323             selectionArgs, String sortOrder, CancellationSignal cancellationSignal) {
324         if (DEBUG) Log.d(TAG, "query " + uri);
325         return null;
326     }
327 
328     @Override
query(Uri uri, String[] projection, Bundle queryArgs, CancellationSignal cancellationSignal)329     public final Cursor query(Uri uri, String[] projection, Bundle queryArgs,
330             CancellationSignal cancellationSignal) {
331         if (DEBUG) Log.d(TAG, "query " + uri);
332         return null;
333     }
334 
335     @Override
insert(Uri uri, ContentValues values)336     public final Uri insert(Uri uri, ContentValues values) {
337         if (DEBUG) Log.d(TAG, "insert " + uri);
338         return null;
339     }
340 
341     @Override
getType(Uri uri)342     public final String getType(Uri uri) {
343         if (DEBUG) Log.d(TAG, "getType " + uri);
344         return SLICE_TYPE;
345     }
346 
347     @Override
call(String method, String arg, Bundle extras)348     public Bundle call(String method, String arg, Bundle extras) {
349         if (method.equals(METHOD_SLICE)) {
350             Uri uri = getUriWithoutUserId(validateIncomingUriOrNull(
351                     extras.getParcelable(EXTRA_BIND_URI, android.net.Uri.class)));
352             List<SliceSpec> supportedSpecs = extras.getParcelableArrayList(EXTRA_SUPPORTED_SPECS, android.app.slice.SliceSpec.class);
353 
354             String callingPackage = getCallingPackage();
355             int callingUid = Binder.getCallingUid();
356             int callingPid = Binder.getCallingPid();
357 
358             Slice s = handleBindSlice(uri, supportedSpecs, callingPackage, callingUid, callingPid);
359             Bundle b = new Bundle();
360             b.putParcelable(EXTRA_SLICE, s);
361             return b;
362         } else if (method.equals(METHOD_MAP_INTENT)) {
363             Intent intent = extras.getParcelable(EXTRA_INTENT, android.content.Intent.class);
364             if (intent == null) return null;
365             Uri uri = validateIncomingUriOrNull(onMapIntentToUri(intent));
366             List<SliceSpec> supportedSpecs = extras.getParcelableArrayList(EXTRA_SUPPORTED_SPECS, android.app.slice.SliceSpec.class);
367             Bundle b = new Bundle();
368             if (uri != null) {
369                 Slice s = handleBindSlice(uri, supportedSpecs, getCallingPackage(),
370                         Binder.getCallingUid(), Binder.getCallingPid());
371                 b.putParcelable(EXTRA_SLICE, s);
372             } else {
373                 b.putParcelable(EXTRA_SLICE, null);
374             }
375             return b;
376         } else if (method.equals(METHOD_MAP_ONLY_INTENT)) {
377             Intent intent = extras.getParcelable(EXTRA_INTENT, android.content.Intent.class);
378             if (intent == null) return null;
379             Uri uri = validateIncomingUriOrNull(onMapIntentToUri(intent));
380             Bundle b = new Bundle();
381             b.putParcelable(EXTRA_SLICE, uri);
382             return b;
383         } else if (method.equals(METHOD_PIN)) {
384             Uri uri = getUriWithoutUserId(validateIncomingUriOrNull(
385                     extras.getParcelable(EXTRA_BIND_URI, android.net.Uri.class)));
386             if (Binder.getCallingUid() != Process.SYSTEM_UID) {
387                 throw new SecurityException("Only the system can pin/unpin slices");
388             }
389             handlePinSlice(uri);
390         } else if (method.equals(METHOD_UNPIN)) {
391             Uri uri = getUriWithoutUserId(validateIncomingUriOrNull(
392                     extras.getParcelable(EXTRA_BIND_URI, android.net.Uri.class)));
393             if (Binder.getCallingUid() != Process.SYSTEM_UID) {
394                 throw new SecurityException("Only the system can pin/unpin slices");
395             }
396             handleUnpinSlice(uri);
397         } else if (method.equals(METHOD_GET_DESCENDANTS)) {
398             Uri uri = getUriWithoutUserId(
399                     validateIncomingUriOrNull(extras.getParcelable(EXTRA_BIND_URI, android.net.Uri.class)));
400             Bundle b = new Bundle();
401             b.putParcelableArrayList(EXTRA_SLICE_DESCENDANTS,
402                     new ArrayList<>(handleGetDescendants(uri)));
403             return b;
404         } else if (method.equals(METHOD_GET_PERMISSIONS)) {
405             if (Binder.getCallingUid() != Process.SYSTEM_UID) {
406                 throw new SecurityException("Only the system can get permissions");
407             }
408             Bundle b = new Bundle();
409             b.putStringArray(EXTRA_RESULT, mAutoGrantPermissions);
410             return b;
411         }
412         return super.call(method, arg, extras);
413     }
414 
validateIncomingUriOrNull(Uri uri)415     private Uri validateIncomingUriOrNull(Uri uri) {
416         return uri == null ? null : validateIncomingUri(uri);
417     }
418 
handleGetDescendants(Uri uri)419     private Collection<Uri> handleGetDescendants(Uri uri) {
420         mCallback = "onGetSliceDescendants";
421         return onGetSliceDescendants(uri);
422     }
423 
handlePinSlice(Uri sliceUri)424     private void handlePinSlice(Uri sliceUri) {
425         mCallback = "onSlicePinned";
426         Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
427         try {
428             onSlicePinned(sliceUri);
429         } finally {
430             Handler.getMain().removeCallbacks(mAnr);
431         }
432     }
433 
handleUnpinSlice(Uri sliceUri)434     private void handleUnpinSlice(Uri sliceUri) {
435         mCallback = "onSliceUnpinned";
436         Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
437         try {
438             onSliceUnpinned(sliceUri);
439         } finally {
440             Handler.getMain().removeCallbacks(mAnr);
441         }
442     }
443 
handleBindSlice(Uri sliceUri, List<SliceSpec> supportedSpecs, String callingPkg, int callingUid, int callingPid)444     private Slice handleBindSlice(Uri sliceUri, List<SliceSpec> supportedSpecs,
445             String callingPkg, int callingUid, int callingPid) {
446         // This can be removed once Slice#bindSlice is removed and everyone is using
447         // SliceManager#bindSlice.
448         String pkg = callingPkg != null ? callingPkg
449                 : getContext().getPackageManager().getNameForUid(callingUid);
450         try {
451             mSliceManager.enforceSlicePermission(sliceUri, callingPid, callingUid,
452                     mAutoGrantPermissions);
453         } catch (SecurityException e) {
454             return createPermissionSlice(getContext(), sliceUri, pkg);
455         }
456         mCallback = "onBindSlice";
457         Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
458         try {
459             return onBindSliceStrict(sliceUri, supportedSpecs);
460         } finally {
461             Handler.getMain().removeCallbacks(mAnr);
462         }
463     }
464 
465     /**
466      * @hide
467      */
createPermissionSlice(Context context, Uri sliceUri, String callingPackage)468     public Slice createPermissionSlice(Context context, Uri sliceUri,
469             String callingPackage) {
470         PendingIntent action;
471         mCallback = "onCreatePermissionRequest";
472         Handler.getMain().postDelayed(mAnr, SLICE_BIND_ANR);
473         try {
474             action = onCreatePermissionRequest(sliceUri);
475         } finally {
476             Handler.getMain().removeCallbacks(mAnr);
477         }
478         Slice.Builder parent = new Slice.Builder(sliceUri, null);
479         Slice.Builder childAction = new Slice.Builder(parent)
480                 .addIcon(Icon.createWithResource(context,
481                         com.android.internal.R.drawable.ic_permission), null,
482                         Collections.emptyList())
483                 .addHints(Arrays.asList(Slice.HINT_TITLE, Slice.HINT_SHORTCUT))
484                 .addAction(action, new Slice.Builder(parent).build(), null);
485 
486         TypedValue tv = new TypedValue();
487         new ContextThemeWrapper(context, android.R.style.Theme_DeviceDefault_Light)
488                 .getTheme().resolveAttribute(android.R.attr.colorAccent, tv, true);
489         int deviceDefaultAccent = tv.data;
490 
491         Uri subSliceUri = sliceUri.buildUpon().appendPath("permission").build();
492         Slice.Builder subSlice = new Slice.Builder(subSliceUri, null)
493                 .addIcon(Icon.createWithResource(context,
494                         com.android.internal.R.drawable.ic_arrow_forward), null,
495                         Collections.emptyList())
496                 .addText(getPermissionString(context, callingPackage), null,
497                         Collections.emptyList())
498                 .addInt(deviceDefaultAccent, SUBTYPE_COLOR,
499                         Collections.emptyList())
500                 .addSubSlice(childAction.build(), null);
501         parent.addSubSlice(subSlice.build(), null);
502         return parent.addHints(Arrays.asList(Slice.HINT_PERMISSION_REQUEST)).build();
503     }
504 
505     /**
506      * @hide
507      */
createPermissionPendingIntent(Context context, Uri sliceUri, String callingPackage)508     public static PendingIntent createPermissionPendingIntent(Context context, Uri sliceUri,
509             String callingPackage) {
510         return PendingIntent.getActivity(context, 0,
511                 createPermissionIntent(context, sliceUri, callingPackage),
512                 PendingIntent.FLAG_IMMUTABLE);
513     }
514 
515     /**
516      * @hide
517      */
createPermissionIntent(Context context, Uri sliceUri, String callingPackage)518     public static Intent createPermissionIntent(Context context, Uri sliceUri,
519             String callingPackage) {
520         Intent intent = new Intent(SliceManager.ACTION_REQUEST_SLICE_PERMISSION);
521         intent.setComponent(ComponentName.unflattenFromString(context.getResources().getString(
522                 com.android.internal.R.string.config_slicePermissionComponent)));
523         intent.putExtra(EXTRA_BIND_URI, sliceUri);
524         intent.putExtra(EXTRA_PKG, callingPackage);
525         // Unique pending intent.
526         intent.setData(sliceUri.buildUpon().appendQueryParameter("package", callingPackage)
527                 .build());
528         return intent;
529     }
530 
531     /**
532      * @hide
533      */
getPermissionString(Context context, String callingPackage)534     public static CharSequence getPermissionString(Context context, String callingPackage) {
535         PackageManager pm = context.getPackageManager();
536         try {
537             return context.getString(
538                     com.android.internal.R.string.slices_permission_request,
539                     pm.getApplicationInfo(callingPackage, 0).loadLabel(pm),
540                     context.getApplicationInfo().loadLabel(pm));
541         } catch (NameNotFoundException e) {
542             // This shouldn't be possible since the caller is verified.
543             throw new RuntimeException("Unknown calling app", e);
544         }
545     }
546 
onBindSliceStrict(Uri sliceUri, List<SliceSpec> supportedSpecs)547     private Slice onBindSliceStrict(Uri sliceUri, List<SliceSpec> supportedSpecs) {
548         ThreadPolicy oldPolicy = StrictMode.getThreadPolicy();
549         try {
550             StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
551                     .detectAll()
552                     .penaltyDeath()
553                     .build());
554             return onBindSlice(sliceUri, new ArraySet<>(supportedSpecs));
555         } finally {
556             StrictMode.setThreadPolicy(oldPolicy);
557         }
558     }
559 
560     private final Runnable mAnr = () -> {
561         Process.sendSignal(Process.myPid(), Process.SIGNAL_QUIT);
562         Log.wtf(TAG, "Timed out while handling slice callback " + mCallback);
563     };
564 }
565