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      1 /*
      2  * Copyright (C) 2016 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 
     17 package com.android.server.om;
     18 
     19 import static com.android.server.om.OverlayManagerService.DEBUG;
     20 import static com.android.server.om.OverlayManagerService.TAG;
     21 
     22 import android.annotation.NonNull;
     23 import android.content.om.OverlayInfo;
     24 import android.content.pm.PackageInfo;
     25 import android.os.UserHandle;
     26 import android.util.Slog;
     27 
     28 import com.android.server.pm.Installer.InstallerException;
     29 import com.android.server.pm.Installer;
     30 
     31 import java.io.DataInputStream;
     32 import java.io.File;
     33 import java.io.FileInputStream;
     34 import java.io.IOException;
     35 
     36 /**
     37  * Handle the creation and deletion of idmap files.
     38  *
     39  * The actual work is performed by the idmap binary, launched through Installer
     40  * and installd.
     41  *
     42  * Note: this class is subclassed in the OMS unit tests, and hence not marked as final.
     43  */
     44 class IdmapManager {
     45     private final Installer mInstaller;
     46 
     47     IdmapManager(final Installer installer) {
     48         mInstaller = installer;
     49     }
     50 
     51     boolean createIdmap(@NonNull final PackageInfo targetPackage,
     52             @NonNull final PackageInfo overlayPackage, int userId) {
     53         // unused userId: see comment in OverlayManagerServiceImpl.removeIdmapIfPossible
     54         if (DEBUG) {
     55             Slog.d(TAG, "create idmap for " + targetPackage.packageName + " and "
     56                     + overlayPackage.packageName);
     57         }
     58         final int sharedGid = UserHandle.getSharedAppGid(targetPackage.applicationInfo.uid);
     59         final String targetPath = targetPackage.applicationInfo.getBaseCodePath();
     60         final String overlayPath = overlayPackage.applicationInfo.getBaseCodePath();
     61         try {
     62             mInstaller.idmap(targetPath, overlayPath, sharedGid);
     63         } catch (InstallerException e) {
     64             Slog.w(TAG, "failed to generate idmap for " + targetPath + " and "
     65                     + overlayPath + ": " + e.getMessage());
     66             return false;
     67         }
     68         return true;
     69     }
     70 
     71     boolean removeIdmap(@NonNull final OverlayInfo oi, final int userId) {
     72         // unused userId: see comment in OverlayManagerServiceImpl.removeIdmapIfPossible
     73         if (DEBUG) {
     74             Slog.d(TAG, "remove idmap for " + oi.baseCodePath);
     75         }
     76         try {
     77             mInstaller.removeIdmap(oi.baseCodePath);
     78         } catch (InstallerException e) {
     79             Slog.w(TAG, "failed to remove idmap for " + oi.baseCodePath + ": " + e.getMessage());
     80             return false;
     81         }
     82         return true;
     83     }
     84 
     85     boolean idmapExists(@NonNull final OverlayInfo oi) {
     86         // unused OverlayInfo.userId: see comment in OverlayManagerServiceImpl.removeIdmapIfPossible
     87         return new File(getIdmapPath(oi.baseCodePath)).isFile();
     88     }
     89 
     90     boolean idmapExists(@NonNull final PackageInfo overlayPackage, final int userId) {
     91         // unused userId: see comment in OverlayManagerServiceImpl.removeIdmapIfPossible
     92         return new File(getIdmapPath(overlayPackage.applicationInfo.getBaseCodePath())).isFile();
     93     }
     94 
     95     private String getIdmapPath(@NonNull final String baseCodePath) {
     96         final StringBuilder sb = new StringBuilder("/data/resource-cache/");
     97         sb.append(baseCodePath.substring(1).replace('/', '@'));
     98         sb.append("@idmap");
     99         return sb.toString();
    100     }
    101 }
    102