Add hidden APIs to query and delete shared blobs.

Bug: 150804006
Test: atest --test-mapping apex/blobstore
Change-Id: Ia445715879c1b6ec74c2a2ee9d2ff0eb1f4ee72b

3 files changed, 130 insertions, 26 deletions

diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java b/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
index dab4797b313f..970766d2c8a6 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobMetadata.java
@@ -15,7 +15,6 @@
  */
 package com.android.server.blob;
 
-import static android.app.blob.BlobStoreManager.DESC_RES_TYPE_STRING;
 import static android.app.blob.XmlTags.ATTR_DESCRIPTION;
 import static android.app.blob.XmlTags.ATTR_DESCRIPTION_RES_NAME;
 import static android.app.blob.XmlTags.ATTR_EXPIRY_TIME;
@@ -30,16 +29,16 @@ import static android.app.blob.XmlTags.TAG_LEASEE;
 import static android.os.Process.INVALID_UID;
 import static android.system.OsConstants.O_RDONLY;
 
-import static com.android.server.blob.BlobStoreConfig.LOGV;
 import static com.android.server.blob.BlobStoreConfig.TAG;
 import static com.android.server.blob.BlobStoreConfig.XML_VERSION_ADD_DESC_RES_NAME;
 import static com.android.server.blob.BlobStoreConfig.XML_VERSION_ADD_STRING_DESC;
+import static com.android.server.blob.BlobStoreUtils.getDescriptionResourceId;
+import static com.android.server.blob.BlobStoreUtils.getPackageResources;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.app.blob.BlobHandle;
 import android.content.Context;
-import android.content.pm.PackageManager;
 import android.content.res.ResourceId;
 import android.content.res.Resources;
 import android.os.ParcelFileDescriptor;
@@ -65,6 +64,7 @@ import java.io.File;
 import java.io.FileDescriptor;
 import java.io.IOException;
 import java.util.Objects;
+import java.util.function.Consumer;
 
 class BlobMetadata {
     private final Object mMetadataLock = new Object();
@@ -281,6 +281,10 @@ class BlobMetadata {
         return false;
     }
 
+    void forEachLeasee(Consumer<Leasee> consumer) {
+        mLeasees.forEach(consumer);
+    }
+
     File getBlobFile() {
         if (mBlobFile == null) {
             mBlobFile = BlobStoreConfig.getBlobFile(mBlobId);
@@ -506,16 +510,9 @@ class BlobMetadata {
             if (resources == null) {
                 return null;
             }
-            try {
-                final int resId = resources.getIdentifier(descriptionResEntryName,
-                        DESC_RES_TYPE_STRING, packageName);
-                return resId <= 0 ? null : resources.getString(resId);
-            } catch (Resources.NotFoundException e) {
-                if (LOGV) {
-                    Slog.w(TAG, "Description resource not found", e);
-                }
-                return null;
-            }
+            final int resId = getDescriptionResourceId(resources, descriptionResEntryName,
+                    packageName);
+            return resId == Resources.ID_NULL ? null : resources.getString(resId);
         }
 
         @Nullable
@@ -546,19 +543,6 @@ class BlobMetadata {
             return desc == null ? "<none>" : desc;
         }
 
-        @Nullable
-        private static Resources getPackageResources(@NonNull Context context,
-                @NonNull String packageName, int userId) {
-            try {
-                return context.getPackageManager()
-                        .getResourcesForApplicationAsUser(packageName, userId);
-            } catch (PackageManager.NameNotFoundException e) {
-                Slog.d(TAG, "Unknown package in user " + userId + ": "
-                        + packageName, e);
-                return null;
-            }
-        }
-
         void writeToXml(@NonNull XmlSerializer out) throws IOException {
             XmlUtils.writeStringAttribute(out, ATTR_PACKAGE, packageName);
             XmlUtils.writeIntAttribute(out, ATTR_UID, uid);
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java b/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
index 96f7b7aee165..ed3dda44e131 100644
--- a/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobStoreManagerService.java
@@ -36,6 +36,8 @@ import static com.android.server.blob.BlobStoreSession.STATE_COMMITTED;
 import static com.android.server.blob.BlobStoreSession.STATE_VERIFIED_INVALID;
 import static com.android.server.blob.BlobStoreSession.STATE_VERIFIED_VALID;
 import static com.android.server.blob.BlobStoreSession.stateToString;
+import static com.android.server.blob.BlobStoreUtils.getDescriptionResourceId;
+import static com.android.server.blob.BlobStoreUtils.getPackageResources;
 
 import android.annotation.CurrentTimeSecondsLong;
 import android.annotation.IdRes;
@@ -43,7 +45,9 @@ import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.UserIdInt;
+import android.app.blob.AccessorInfo;
 import android.app.blob.BlobHandle;
+import android.app.blob.BlobInfo;
 import android.app.blob.IBlobStoreManager;
 import android.app.blob.IBlobStoreSession;
 import android.content.BroadcastReceiver;
@@ -100,6 +104,7 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.lang.ref.WeakReference;
 import java.nio.charset.StandardCharsets;
 import java.security.SecureRandom;
 import java.util.ArrayList;
@@ -110,6 +115,7 @@ import java.util.Random;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.Consumer;
+import java.util.function.Function;
 
 /**
  * Service responsible for maintaining and facilitating access to data blobs published by apps.
@@ -434,6 +440,48 @@ public class BlobStoreManagerService extends SystemService {
         }
     }
 
+    private List<BlobInfo> queryBlobsForUserInternal(int userId) {
+        final ArrayList<BlobInfo> blobInfos = new ArrayList<>();
+        synchronized (mBlobsLock) {
+            final ArrayMap<String, WeakReference<Resources>> resources = new ArrayMap<>();
+            final Function<String, Resources> resourcesGetter = (packageName) -> {
+                final WeakReference<Resources> resourcesRef = resources.get(packageName);
+                Resources packageResources = resourcesRef == null ? null : resourcesRef.get();
+                if (packageResources == null) {
+                    packageResources = getPackageResources(mContext, packageName, userId);
+                    resources.put(packageName, new WeakReference<>(packageResources));
+                }
+                return packageResources;
+            };
+            getUserBlobsLocked(userId).forEach((blobHandle, blobMetadata) -> {
+                final ArrayList<AccessorInfo> accessorInfos = new ArrayList<>();
+                blobMetadata.forEachLeasee(leasee -> {
+                    final int descriptionResId = leasee.descriptionResEntryName == null
+                            ? Resources.ID_NULL
+                            : getDescriptionResourceId(resourcesGetter.apply(leasee.packageName),
+                                    leasee.descriptionResEntryName, leasee.packageName);
+                    accessorInfos.add(new AccessorInfo(leasee.packageName, leasee.expiryTimeMillis,
+                            descriptionResId, leasee.description));
+                });
+                blobInfos.add(new BlobInfo(blobMetadata.getBlobId(),
+                        blobHandle.getExpiryTimeMillis(), blobHandle.getLabel(), accessorInfos));
+            });
+        }
+        return blobInfos;
+    }
+
+    private void deleteBlobInternal(long blobId, int callingUid) {
+        synchronized (mBlobsLock) {
+            final ArrayMap<BlobHandle, BlobMetadata> userBlobs = getUserBlobsLocked(
+                    UserHandle.getUserId(callingUid));
+            userBlobs.entrySet().removeIf(entry -> {
+                final BlobMetadata blobMetadata = entry.getValue();
+                return blobMetadata.getBlobId() == blobId;
+            });
+            writeBlobsInfoAsync();
+        }
+    }
+
     private void verifyCallingPackage(int callingUid, String callingPackage) {
         if (mPackageManagerInternal.getPackageUid(
                 callingPackage, 0, UserHandle.getUserId(callingUid)) != callingUid) {
@@ -1250,6 +1298,28 @@ public class BlobStoreManagerService extends SystemService {
         }
 
         @Override
+        @NonNull
+        public List<BlobInfo> queryBlobsForUser(@UserIdInt int userId) {
+            if (Binder.getCallingUid() != Process.SYSTEM_UID) {
+                throw new SecurityException("Only system uid is allowed to call "
+                        + "queryBlobsForUser()");
+            }
+
+            return queryBlobsForUserInternal(userId);
+        }
+
+        @Override
+        public void deleteBlob(long blobId) {
+            final int callingUid = Binder.getCallingUid();
+            if (callingUid != Process.SYSTEM_UID) {
+                throw new SecurityException("Only system uid is allowed to call "
+                        + "deleteBlob()");
+            }
+
+            deleteBlobInternal(blobId, callingUid);
+        }
+
+        @Override
         public void dump(@NonNull FileDescriptor fd, @NonNull PrintWriter writer,
                 @Nullable String[] args) {
             // TODO: add proto-based version of this.
diff --git a/apex/blobstore/service/java/com/android/server/blob/BlobStoreUtils.java b/apex/blobstore/service/java/com/android/server/blob/BlobStoreUtils.java
new file mode 100644
index 000000000000..6af540acd6a4
--- /dev/null
+++ b/apex/blobstore/service/java/com/android/server/blob/BlobStoreUtils.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2020 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.server.blob;
+
+import static com.android.server.blob.BlobStoreConfig.TAG;
+
+import android.annotation.IdRes;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.content.res.Resources;
+import android.util.Slog;
+
+class BlobStoreUtils {
+    private static final String DESC_RES_TYPE_STRING = "string";
+
+    @Nullable
+    static Resources getPackageResources(@NonNull Context context,
+            @NonNull String packageName, int userId) {
+        try {
+            return context.getPackageManager()
+                    .getResourcesForApplicationAsUser(packageName, userId);
+        } catch (PackageManager.NameNotFoundException e) {
+            Slog.d(TAG, "Unknown package in user " + userId + ": "
+                    + packageName, e);
+            return null;
+        }
+    }
+
+    @IdRes
+    static int getDescriptionResourceId(@NonNull Resources resources,
+            @NonNull String resourceEntryName, @NonNull String packageName) {
+        return resources.getIdentifier(resourceEntryName, DESC_RES_TYPE_STRING, packageName);
+    }
+}