Generate /data/system/packages.list in the PackageManager

This file contains uid + debugFlag + dataPath information for
each non-system installed package. It is meant to be used later
from native code and thus needs to be considerably simpler to
parser than packages.xml.

The file should only be readable by non-system userIds, and its
format is essentially line-based with each line like:

  <pkgName> <uid> <debugFlag> <dataDir>

With:

  <pkgName>    as the package name
  <uid>        as the application-specific user id
  <debugFlag>  either 0 or 1. 1 if the package is debuggable
  <dataDir>    path to the package's data directory

We need the debug flag to allow 'run-as' to only allow
commands to be executed on debuggable packages, even on
production devices.

diff --git a/services/java/com/android/server/PackageManagerService.java b/services/java/com/android/server/PackageManagerService.java
index b1e5d32..10bf851 100644 (file)
--- a/services/java/com/android/server/PackageManagerService.java
+++ b/services/java/com/android/server/PackageManagerService.java
@@ -20,6 +20,7 @@ import com.android.internal.app.IMediaContainerService;
 import com.android.internal.app.ResolverActivity;
 import com.android.common.FastXmlSerializer;
 import com.android.common.XmlUtils;
+import com.android.server.JournaledFile;
 
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
@@ -6826,6 +6827,7 @@ class PackageManagerService extends IPackageManager.Stub {
     private static final class Settings {
         private final File mSettingsFilename;
         private final File mBackupSettingsFilename;
+        private final File mPackageListFilename;
         private final HashMap<String, PackageSetting> mPackages =
                 new HashMap<String, PackageSetting>();
         // List of replaced system applications
@@ -6907,6 +6909,7 @@ class PackageManagerService extends IPackageManager.Stub {
                     -1, -1);
             mSettingsFilename = new File(systemDir, "packages.xml");
             mBackupSettingsFilename = new File(systemDir, "packages-backup.xml");
+            mPackageListFilename = new File(systemDir, "packages.list");
         }
 
         PackageSetting getPackageLP(PackageParser.Package pkg, PackageSetting origPackage,
@@ -7446,7 +7449,7 @@ class PackageManagerService extends IPackageManager.Stub {
                         serializer.endTag(null, "cleaning-package");
                     }
                 }
-                
+
                 serializer.endTag(null, "packages");
 
                 serializer.endDocument();
@@ -7462,6 +7465,61 @@ class PackageManagerService extends IPackageManager.Stub {
                         |FileUtils.S_IRGRP|FileUtils.S_IWGRP
                         |FileUtils.S_IROTH,
                         -1, -1);
+
+                // Write package list file now, use a JournaledFile.
+                //
+                File tempFile = new File(mPackageListFilename.toString() + ".tmp");
+                JournaledFile journal = new JournaledFile(mPackageListFilename, tempFile);
+
+                str = new FileOutputStream(journal.chooseForWrite());
+                try {
+                    StringBuilder sb = new StringBuilder();
+                    for (PackageSetting pkg : mPackages.values()) {
+                        ApplicationInfo ai = pkg.pkg.applicationInfo;
+                        String  dataPath = ai.dataDir;
+                        boolean isDebug  = (ai.flags & ApplicationInfo.FLAG_DEBUGGABLE) != 0;
+
+                        // Avoid any application that has a space in its path
+                        // or that is handled by the system.
+                        if (dataPath.indexOf(" ") >= 0 || ai.uid <= Process.FIRST_APPLICATION_UID)
+                            continue;
+
+                        // we store on each line the following information for now:
+                        //
+                        // pkgName    - package name
+                        // userId     - application-specific user id
+                        // debugFlag  - 0 or 1 if the package is debuggable.
+                        // dataPath   - path to package's data path
+                        //
+                        // NOTE: We prefer not to expose all ApplicationInfo flags for now.
+                        //
+                        // DO NOT MODIFY THIS FORMAT UNLESS YOU CAN ALSO MODIFY ITS USERS
+                        // FROM NATIVE CODE. AT THE MOMENT, LOOK AT THE FOLLOWING SOURCES:
+                        //   system/core/run-as/run-as.c
+                        //
+                        sb.setLength(0);
+                        sb.append(ai.packageName);
+                        sb.append(" ");
+                        sb.append((int)ai.uid);
+                        sb.append(isDebug ? " 1 " : " 0 ");
+                        sb.append(dataPath);
+                        sb.append("\n");
+                        str.write(sb.toString().getBytes());
+                    }
+                    str.flush();
+                    str.close();
+                    journal.commit();
+                }
+                catch (Exception  e) {
+                    journal.rollback();
+                }
+
+                FileUtils.setPermissions(mPackageListFilename.toString(),
+                        FileUtils.S_IRUSR|FileUtils.S_IWUSR
+                        |FileUtils.S_IRGRP|FileUtils.S_IWGRP
+                        |FileUtils.S_IROTH,
+                        -1, -1);
+
                 return;
 
             } catch(XmlPullParserException e) {
@@ -7469,7 +7527,7 @@ class PackageManagerService extends IPackageManager.Stub {
             } catch(java.io.IOException e) {
                 Log.w(TAG, "Unable to write package manager settings, current changes will be lost at reboot", e);
             }
-            // Clean up partially written file
+            // Clean up partially written files
             if (mSettingsFilename.exists()) {
                 if (!mSettingsFilename.delete()) {
                     Log.i(TAG, "Failed to clean up mangled file: " + mSettingsFilename);