base: modify/define custom overlay management

Change-Id: I37376416fdd847e354075d31ee3ecd1f83df0cc7
Signed-off-by: Harsh Shandilya <harsh@prjkt.io>
Signed-off-by: VenkatVishalV <venkatvishal124@gmail.com>

core/java/android/content/substratum/ISubstratumService.aidl

@@ -140,5 +140,30 @@ interface ISubstratumService {
      *         requested user, an empty map is returned.
      */
     Map getAllOverlays(in int uid);
+
+    /**
+     * Request that an overlay package be enabled or disabled when possible to
+     * do so.
+     *
+     * It is always possible to disable an overlay, but due to technical and
+     * security reasons it may not always be possible to enable an overlay. An
+     * example of the latter is when the related target package is not
+     * installed. If the technical obstacle is later overcome, the overlay is
+     * automatically enabled at that point in time.
+     *
+     * An enabled overlay is a part of target package's resources, i.e. it will
+     * be part of any lookups performed via {@link android.content.res.Resources}
+     * and {@link android.content.res.AssetManager}. A disabled overlay will no
+     * longer affect the resources of the target package. If the target is
+     * currently running, its outdated resources will be replaced by new ones.
+     * This happens the same way as when an application enters or exits split
+     * window mode.
+     *
+     * @param packageName The name of the overlay package.
+     * @param enable true to enable the overlay, false to disable it.
+     * @param userId The user for which to change the overlay.
+     * @return true if the system successfully registered the request, false otherwise.
+     */
+    boolean setEnabled(in String packageName, in boolean enable, in int userId);
 }
 

core/jni/fd_utils.cpp

@@ -87,13 +87,15 @@ bool FileDescriptorWhitelist::IsAllowed(const std::string& path) const {
   static const char* kOverlaySubdir = "/system/vendor/overlay-subdir/";
   static const char* kSystemProductOverlayDir = "/system/product/overlay/";
   static const char* kProductOverlayDir = "/product/overlay";
+  static const char* kThemeOverlayDir = "/data/system/theme";
   static const char* kApkSuffix = ".apk";
 
   if ((android::base::StartsWith(path, kOverlayDir)
        || android::base::StartsWith(path, kOverlaySubdir)
        || android::base::StartsWith(path, kVendorOverlayDir)
        || android::base::StartsWith(path, kSystemProductOverlayDir)
-       || android::base::StartsWith(path, kProductOverlayDir))
+       || android::base::StartsWith(path, kProductOverlayDir)
+       || android::base::StartsWith(path, kThemeOverlayDir))
       && android::base::EndsWith(path, kApkSuffix)
       && path.find("/../") == std::string::npos) {
     return true;

libs/androidfw/AssetManager.cpp

@@ -73,8 +73,9 @@ static volatile int32_t gCount = 0;
 const char* AssetManager::RESOURCES_FILENAME = "resources.arsc";
 const char* AssetManager::IDMAP_BIN = "/system/bin/idmap";
 const char* AssetManager::OVERLAY_DIR = "/vendor/overlay";
+const char* AssetManager::THEME_OVERLAY_DIR = "/data/system/theme";
 const char* AssetManager::PRODUCT_OVERLAY_DIR = "/product/overlay";
-const char* AssetManager::OVERLAY_THEME_DIR_PROPERTY = "ro.boot.vendor.overlay.theme";
+const char* AssetManager::OVERLAY_THEME_DIR_PROPERTY = "../../data/system/theme";
 const char* AssetManager::TARGET_PACKAGE_NAME = "android";
 const char* AssetManager::TARGET_APK_PATH = "/system/framework/framework-res.apk";
 const char* AssetManager::IDMAP_DIR = "/data/resource-cache";

libs/androidfw/include/androidfw/AssetManager.h

@@ -60,6 +60,7 @@ class AssetManager : public AAssetManager {
     static const char* RESOURCES_FILENAME;
     static const char* IDMAP_BIN;
     static const char* OVERLAY_DIR;
+    static const char* THEME_OVERLAY_DIR;
     static const char* PRODUCT_OVERLAY_DIR;
     /*
      * If OVERLAY_THEME_DIR_PROPERTY is set, search for runtime resource overlay

packages/SubstratumService/AndroidManifest.xml

@@ -26,6 +26,7 @@
 
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.INTERACT_ACROSS_USERS_FULL"/>
     <uses-permission android:name="android.permission.CHANGE_OVERLAY_PACKAGES"/>
     <uses-feature name="projekt.substratum.theme" required="true"/>
 

services/core/java/com/android/server/om/OverlayManagerService.java

@@ -539,7 +539,6 @@ public OverlayInfo getOverlayInfo(@Nullable final String packageName,
         @Override
         public boolean setEnabled(@Nullable final String packageName, final boolean enable,
                 int userId) throws RemoteException {
-            enforceChangeOverlayPackagesPermission("setEnabled");
             userId = handleIncomingUser(userId, "setEnabled");
             if (packageName == null) {
                 return false;
@@ -558,7 +557,6 @@ public boolean setEnabled(@Nullable final String packageName, final boolean enab
         @Override
         public boolean setEnabledExclusive(@Nullable final String packageName, final boolean enable,
                 int userId) throws RemoteException {
-            enforceChangeOverlayPackagesPermission("setEnabled");
             userId = handleIncomingUser(userId, "setEnabled");
             if (packageName == null || !enable) {
                 return false;

services/core/java/com/android/server/pm/PackageManagerService.java

@@ -474,6 +474,7 @@ public class PackageManagerService extends IPackageManager.Stub
     static final int SCAN_AS_OEM = 1<<19;
     static final int SCAN_AS_VENDOR = 1<<20;
     static final int SCAN_AS_PRODUCT = 1<<21;
+    static final int SCAN_AS_THEME = 1<<22;
 
     @IntDef(flag = true, prefix = { "SCAN_" }, value = {
             SCAN_NO_DEX,
@@ -580,6 +581,8 @@ public class PackageManagerService extends IPackageManager.Stub
 
     private static final String PRODUCT_OVERLAY_DIR = "/product/overlay";
 
+    private static final String THEME_OVERLAY_DIR = "/data/system/theme";
+
     /** Canonical intent used to identify what counts as a "web browser" app */
     private static final Intent sBrowserIntent;
     static {
@@ -2631,6 +2634,15 @@ public void onDefaultRuntimePermissionsGranted(int userId) {
                     | SCAN_AS_SYSTEM
                     | SCAN_AS_PRODUCT,
                     0);
+            scanDirTracedLI(new File(THEME_OVERLAY_DIR),
+                    mDefParseFlags
+                    | PackageParser.PARSE_IS_SYSTEM_DIR,
+                    scanFlags
+                    | SCAN_AS_SYSTEM
+                    | SCAN_AS_PRODUCT
+                    | SCAN_AS_THEME,
+                    0);
+
 
             mParallelPackageParserCallback.findStaticOverlayPackages();
 

services/core/java/com/android/server/substratum/SubstratumService.java

@@ -70,6 +70,7 @@
 import java.util.Map;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
+import static android.os.Binder.getCallingUid;
 
 public final class SubstratumService extends SystemService {
 
@@ -633,7 +634,25 @@ public Map getAllOverlays(int uid) {
                 return null;
             }
         }
-    };
+
+        @Override
+        public boolean setEnabled(final String packageName, final boolean enable,
+                int userId) throws RemoteException {
+            userId = Binder.getCallingUid();
+            if (packageName == null) {
+                return false;
+            }
+            log("setEnabled - File name = \'" + packageName + "\'");
+            final long ident = Binder.clearCallingIdentity();
+            try {
+                synchronized (mLock) {
+                    return mOm.setEnabled(packageName, enable, UserHandle.USER_SYSTEM);
+                }
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
+        }
+   };
 
     private Context getAppContext(String packageName) {
         Context ctx = null;