Reroute Uri conversions though MediaProvider.

Upcoming changes will prevent apps from reading "_data" columns
directly, which is required to convert between DocumentsProvider and
MediaProvider Uris.  To solve this, delegate the call() through
MediaProvider, where it can perform the "_data" lookup on behalf
of the caller.

Also add new getMediaUri() call to offer symmetry.

Bug: 111960973, 117627072, 110961701
Test: atest android.provider.cts.MediaStoreUiTest
Change-Id: I53c640704d86047d7a4bf1702aca027873395abf

5 files changed, 80 insertions, 72 deletions

diff --git a/api/current.txt b/api/current.txt
index 1c3ee82dbba0..7f356af4bf2f 100755
--- a/api/current.txt
+++ b/api/current.txt
@@ -36791,6 +36791,7 @@ package android.provider {
     ctor public MediaStore();
     method public static android.net.Uri getDocumentUri(android.content.Context, android.net.Uri);
     method public static android.net.Uri getMediaScannerUri();
+    method public static android.net.Uri getMediaUri(android.content.Context, android.net.Uri);
     method public static java.lang.String getVersion(android.content.Context);
     field public static final java.lang.String ACTION_IMAGE_CAPTURE = "android.media.action.IMAGE_CAPTURE";
     field public static final java.lang.String ACTION_IMAGE_CAPTURE_SECURE = "android.media.action.IMAGE_CAPTURE_SECURE";
diff --git a/core/java/android/provider/DocumentsContract.java b/core/java/android/provider/DocumentsContract.java
index 954d18abc6e1..67e52aad9206 100644
--- a/core/java/android/provider/DocumentsContract.java
+++ b/core/java/android/provider/DocumentsContract.java
@@ -731,6 +731,8 @@ public final class DocumentsContract {
     public static final String EXTRA_PARENT_URI = "parentUri";
     /** {@hide} */
     public static final String EXTRA_URI = "uri";
+    /** {@hide} */
+    public static final String EXTRA_URI_PERMISSIONS = "uriPermissions";
 
     /**
      * @see #createWebLinkIntent(ContentResolver, Uri, Bundle)
diff --git a/core/java/android/provider/MediaStore.java b/core/java/android/provider/MediaStore.java
index f5660b950c0a..57f33f02ac42 100644
--- a/core/java/android/provider/MediaStore.java
+++ b/core/java/android/provider/MediaStore.java
@@ -46,9 +46,6 @@ import android.util.Log;
 
 import com.android.internal.annotations.GuardedBy;
 
-import libcore.io.IoUtils;
-
-import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
@@ -82,6 +79,11 @@ public final class MediaStore {
      */
     public static final String RETRANSLATE_CALL = "update_titles";
 
+    /** {@hide} */
+    public static final String GET_DOCUMENT_URI_CALL = "get_document_uri";
+    /** {@hide} */
+    public static final String GET_MEDIA_URI_CALL = "get_media_uri";
+
     /**
      * This is for internal use by the media scanner only.
      * Name of the (optional) Uri parameter that determines whether to skip deleting
@@ -2275,84 +2277,62 @@ public final class MediaStore {
     }
 
     /**
-     * Gets a URI backed by a {@link DocumentsProvider} that points to the same media
-     * file as the specified mediaUri. This allows apps who have permissions to access
-     * media files in Storage Access Framework to perform file operations through that
-     * on media files.
+     * Return a {@link DocumentsProvider} Uri that is an equivalent to the given
+     * {@link MediaStore} Uri.
      * <p>
-     * Note: this method doesn't grant any URI permission. Callers need to obtain
-     * permission before calling this method. One way to obtain permission is through
-     * a 3-step process:
-     * <ol>
-     *     <li>Call {@link android.os.storage.StorageManager#getStorageVolume(File)} to
-     *     obtain the {@link android.os.storage.StorageVolume} of a media file;</li>
+     * This allows apps with Storage Access Framework permissions to convert
+     * between {@link MediaStore} and {@link DocumentsProvider} Uris that refer
+     * to the same underlying item. Note that this method doesn't grant any new
+     * permissions; callers must already hold permissions obtained with
+     * {@link Intent#ACTION_OPEN_DOCUMENT} or related APIs.
      *
-     *     <li>Invoke the intent returned by
-     *     {@link android.os.storage.StorageVolume#createAccessIntent(String)} to
-     *     obtain the access of the volume or one of its specific subdirectories;</li>
-     *
-     *     <li>Check whether permission is granted and take persistent permission.</li>
-     * </ol>
-     * @param mediaUri the media URI which document URI is requested
-     * @return the document URI
+     * @param mediaUri The {@link MediaStore} Uri to convert.
+     * @return An equivalent {@link DocumentsProvider} Uri. Returns {@code null}
+     *         if no equivalent was found.
+     * @see #getMediaUri(Context, Uri)
      */
     public static Uri getDocumentUri(Context context, Uri mediaUri) {
+        final ContentResolver resolver = context.getContentResolver();
+        final List<UriPermission> uriPermissions = resolver.getPersistedUriPermissions();
 
-        try {
-            final ContentResolver resolver = context.getContentResolver();
-
-            final String path = getFilePath(resolver, mediaUri);
-            final List<UriPermission> uriPermissions = resolver.getPersistedUriPermissions();
-
-            return getDocumentUri(resolver, path, uriPermissions);
+        try (ContentProviderClient client = resolver.acquireContentProviderClient(AUTHORITY)) {
+            final Bundle in = new Bundle();
+            in.putParcelable(DocumentsContract.EXTRA_URI, mediaUri);
+            in.putParcelableList(DocumentsContract.EXTRA_URI_PERMISSIONS, uriPermissions);
+            final Bundle out = client.call(GET_DOCUMENT_URI_CALL, null, in);
+            return out.getParcelable(DocumentsContract.EXTRA_URI);
         } catch (RemoteException e) {
             throw e.rethrowAsRuntimeException();
         }
     }
 
-    private static String getFilePath(ContentResolver resolver, Uri mediaUri)
-            throws RemoteException {
-
-        try (ContentProviderClient client =
-                     resolver.acquireUnstableContentProviderClient(AUTHORITY)) {
-            final Cursor c = client.query(
-                    mediaUri,
-                    new String[]{ MediaColumns.DATA },
-                    null, /* selection */
-                    null, /* selectionArg */
-                    null /* sortOrder */);
-
-            final String path;
-            try {
-                if (c.getCount() == 0) {
-                    throw new IllegalStateException("Not found media file under URI: " + mediaUri);
-                }
-
-                if (!c.moveToFirst()) {
-                    throw new IllegalStateException("Failed to move cursor to the first item.");
-                }
-
-                path = c.getString(0);
-            } finally {
-                IoUtils.closeQuietly(c);
-            }
-
-            return path;
-        }
-    }
-
-    private static Uri getDocumentUri(
-            ContentResolver resolver, String path, List<UriPermission> uriPermissions)
-            throws RemoteException {
+    /**
+     * Return a {@link MediaStore} Uri that is an equivalent to the given
+     * {@link DocumentsProvider} Uri.
+     * <p>
+     * This allows apps with Storage Access Framework permissions to convert
+     * between {@link MediaStore} and {@link DocumentsProvider} Uris that refer
+     * to the same underlying item. Note that this method doesn't grant any new
+     * permissions; callers must already hold permissions obtained with
+     * {@link Intent#ACTION_OPEN_DOCUMENT} or related APIs.
+     *
+     * @param documentUri The {@link DocumentsProvider} Uri to convert.
+     * @return An equivalent {@link MediaStore} Uri. Returns {@code null} if no
+     *         equivalent was found.
+     * @see #getDocumentUri(Context, Uri)
+     */
+    public static Uri getMediaUri(Context context, Uri documentUri) {
+        final ContentResolver resolver = context.getContentResolver();
+        final List<UriPermission> uriPermissions = resolver.getPersistedUriPermissions();
 
-        try (ContentProviderClient client = resolver.acquireUnstableContentProviderClient(
-                DocumentsContract.EXTERNAL_STORAGE_PROVIDER_AUTHORITY)) {
+        try (ContentProviderClient client = resolver.acquireContentProviderClient(AUTHORITY)) {
             final Bundle in = new Bundle();
-            in.putParcelableList(
-                    DocumentsContract.EXTERNAL_STORAGE_PROVIDER_AUTHORITY + ".extra.uriPermissions",
-                    uriPermissions);
-            final Bundle out = client.call("getDocumentId", path, in);
+            in.putParcelable(DocumentsContract.EXTRA_URI, documentUri);
+            in.putParcelableList(DocumentsContract.EXTRA_URI_PERMISSIONS, uriPermissions);
+            final Bundle out = client.call(GET_MEDIA_URI_CALL, null, in);
             return out.getParcelable(DocumentsContract.EXTRA_URI);
+        } catch (RemoteException e) {
+            throw e.rethrowAsRuntimeException();
         }
     }
 }
diff --git a/packages/ExternalStorageProvider/AndroidManifest.xml b/packages/ExternalStorageProvider/AndroidManifest.xml
index 1072f95371a0..484dbccca9a8 100644
--- a/packages/ExternalStorageProvider/AndroidManifest.xml
+++ b/packages/ExternalStorageProvider/AndroidManifest.xml
@@ -17,6 +17,10 @@
             <intent-filter>
                 <action android:name="android.content.action.DOCUMENTS_PROVIDER" />
             </intent-filter>
+            <!-- Stub that allows MediaProvider to make incoming calls -->
+            <path-permission
+                android:path="/media_internal"
+                android:permission="android.permission.WRITE_MEDIA_STORAGE" />
         </provider>
 
         <receiver android:name=".MountReceiver">
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index 62207c5517ec..4e52ff6d016c 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -37,6 +37,7 @@ import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
 import android.provider.DocumentsContract.Path;
 import android.provider.DocumentsContract.Root;
+import android.provider.MediaStore;
 import android.provider.Settings;
 import android.system.ErrnoException;
 import android.system.Os;
@@ -606,11 +607,16 @@ public class ExternalStorageProvider extends FileSystemProvider {
                     }
                     break;
                 }
-                case "getDocumentId": {
-                    final String path = arg;
-                    final List<UriPermission> accessUriPermissions =
-                            extras.getParcelableArrayList(AUTHORITY + ".extra.uriPermissions");
+                case MediaStore.GET_DOCUMENT_URI_CALL: {
+                    // All callers must go through MediaProvider
+                    getContext().enforceCallingPermission(
+                            android.Manifest.permission.WRITE_MEDIA_STORAGE, TAG);
+
+                    final Uri fileUri = extras.getParcelable(DocumentsContract.EXTRA_URI);
+                    final List<UriPermission> accessUriPermissions = extras
+                            .getParcelableArrayList(DocumentsContract.EXTRA_URI_PERMISSIONS);
 
+                    final String path = fileUri.getPath();
                     try {
                         final Bundle out = new Bundle();
                         final Uri uri = getDocumentUri(path, accessUriPermissions);
@@ -619,7 +625,22 @@ public class ExternalStorageProvider extends FileSystemProvider {
                     } catch (FileNotFoundException e) {
                         throw new IllegalStateException("File in " + path + " is not found.", e);
                     }
+                }
+                case MediaStore.GET_MEDIA_URI_CALL: {
+                    // All callers must go through MediaProvider
+                    getContext().enforceCallingPermission(
+                            android.Manifest.permission.WRITE_MEDIA_STORAGE, TAG);
 
+                    final Uri documentUri = extras.getParcelable(DocumentsContract.EXTRA_URI);
+                    final String docId = DocumentsContract.getDocumentId(documentUri);
+                    try {
+                        final Bundle out = new Bundle();
+                        final Uri uri = Uri.fromFile(getFileForDocId(docId));
+                        out.putParcelable(DocumentsContract.EXTRA_URI, uri);
+                        return out;
+                    } catch (FileNotFoundException e) {
+                        throw new IllegalStateException(e);
+                    }
                 }
                 default:
                     Log.w(TAG, "unknown method passed to call(): " + method);