From de4e90a6bdc7b038d327bd0ebda6bb92f496220b Mon Sep 17 00:00:00 2001
From: Abhijeet Kaur <abkaur@google.com>
Date: Thu, 14 May 2020 11:44:15 +0100
Subject: [PATCH] Allow ExternalStorageProvider to access all Android/ dirs

In Scoped Storage world, access to "Android/data" style directories are
hidden for privacy reasons. Files Activity by DocsUI calls
ExternalStorageProvider in managed mode. Allow ExternalStorageProvider
to show these hidden files when in manage mode.

Bug: 150366834
Test: Android/data and Android/obb dirs are not visible in DocsUI Picker
      view (triggered from StorageTestApp or Gmail)
Test: Android/data and Android/obb dirs are accessible from DocsUI Files
      view (triggered from Settings). Android/data shows package dirs.
      Manually adb push video to /obb is accessible.

Change-Id: I2423d8fa695c68a56d630353317b98ff3bb7ad34
---
 .../android/server/StorageManagerService.java | 30 ++++++++++++-------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/services/core/java/com/android/server/StorageManagerService.java b/services/core/java/com/android/server/StorageManagerService.java
index 43ed8538fb0cf..e2a0c29dbf016 100644
--- a/services/core/java/com/android/server/StorageManagerService.java
+++ b/services/core/java/com/android/server/StorageManagerService.java
@@ -121,6 +121,7 @@ import android.os.storage.StorageVolume;
 import android.os.storage.VolumeInfo;
 import android.os.storage.VolumeRecord;
 import android.provider.DeviceConfig;
+import android.provider.DocumentsContract;
 import android.provider.Downloads;
 import android.provider.MediaStore;
 import android.provider.Settings;
@@ -432,6 +433,8 @@ class StorageManagerService extends IStorageManager.Stub
 
     private volatile int mDownloadsAuthorityAppId = -1;
 
+    private volatile int mExternalStorageAuthorityAppId = -1;
+
     private volatile int mCurrentUserId = UserHandle.USER_SYSTEM;
 
     private final Installer mInstaller;
@@ -1923,24 +1926,22 @@ class StorageManagerService extends IStorageManager.Stub
         mIAppOpsService = IAppOpsService.Stub.asInterface(
                 ServiceManager.getService(Context.APP_OPS_SERVICE));
 
-        ProviderInfo provider = mPmInternal.resolveContentProvider(
-                MediaStore.AUTHORITY, PackageManager.MATCH_DIRECT_BOOT_AWARE
-                | PackageManager.MATCH_DIRECT_BOOT_UNAWARE,
-                UserHandle.getUserId(UserHandle.USER_SYSTEM));
+        ProviderInfo provider = getProviderInfo(MediaStore.AUTHORITY);
         if (provider != null) {
             mMediaStoreAuthorityAppId = UserHandle.getAppId(provider.applicationInfo.uid);
             sMediaStoreAuthorityProcessName = provider.applicationInfo.processName;
         }
 
-        provider = mPmInternal.resolveContentProvider(
-                Downloads.Impl.AUTHORITY, PackageManager.MATCH_DIRECT_BOOT_AWARE
-                        | PackageManager.MATCH_DIRECT_BOOT_UNAWARE,
-                UserHandle.getUserId(UserHandle.USER_SYSTEM));
-
+        provider = getProviderInfo(Downloads.Impl.AUTHORITY);
         if (provider != null) {
             mDownloadsAuthorityAppId = UserHandle.getAppId(provider.applicationInfo.uid);
         }
 
+        provider = getProviderInfo(DocumentsContract.EXTERNAL_STORAGE_PROVIDER_AUTHORITY);
+        if (provider != null) {
+            mExternalStorageAuthorityAppId = UserHandle.getAppId(provider.applicationInfo.uid);
+        }
+
         if (!mIsFuseEnabled) {
             try {
                 mIAppOpsService.startWatchingMode(OP_REQUEST_INSTALL_PACKAGES, null,
@@ -1951,6 +1952,13 @@ class StorageManagerService extends IStorageManager.Stub
         }
     }
 
+    private ProviderInfo getProviderInfo(String authority) {
+        return mPmInternal.resolveContentProvider(
+                authority, PackageManager.MATCH_DIRECT_BOOT_AWARE
+                        | PackageManager.MATCH_DIRECT_BOOT_UNAWARE,
+                UserHandle.getUserId(UserHandle.USER_SYSTEM));
+    }
+
     private void updateLegacyStorageApps(String packageName, int uid, boolean hasLegacy) {
         synchronized (mLock) {
             if (hasLegacy) {
@@ -4191,9 +4199,11 @@ class StorageManagerService extends IStorageManager.Stub
                 return Zygote.MOUNT_EXTERNAL_PASS_THROUGH;
             }
 
-            if (mIsFuseEnabled && mDownloadsAuthorityAppId == UserHandle.getAppId(uid)) {
+            if (mIsFuseEnabled && (mDownloadsAuthorityAppId == UserHandle.getAppId(uid)
+                    || mExternalStorageAuthorityAppId == UserHandle.getAppId(uid))) {
                 // DownloadManager can write in app-private directories on behalf of apps;
                 // give it write access to Android/
+                // ExternalStorageProvider can access Android/{data,obb} dirs in managed mode
                 return Zygote.MOUNT_EXTERNAL_ANDROID_WRITABLE;
             }