Report FBE through a feature string.

Since devices can be converted to enable/disable FBE across a
factory reset, we offer to add the features dynamically depending
on device status.

Bug: 26808417
Change-Id: I905140ba500a5e69756b547f2b1d6167b9a37dc6

4 files changed, 42 insertions, 13 deletions

diff --git a/core/java/android/content/pm/PackageManager.java b/core/java/android/content/pm/PackageManager.java
index 476dc46a2118..aaa02bd9ce8e 100644
--- a/core/java/android/content/pm/PackageManager.java
+++ b/core/java/android/content/pm/PackageManager.java
@@ -2017,6 +2017,11 @@ public abstract class PackageManager {
     public static final String FEATURE_SECURELY_REMOVES_USERS
             = "android.software.securely_removes_users";
 
+    /** {@hide} */
+    @SdkConstant(SdkConstantType.FEATURE)
+    public static final String FEATURE_FILE_BASED_ENCRYPTION
+            = "android.software.file_based_encryption";
+
     /**
      * Feature for {@link #getSystemAvailableFeatures} and {@link #hasSystemFeature}:
      * The device has a full implementation of the android.webkit.* APIs. Devices
diff --git a/services/core/java/com/android/server/DiskStatsService.java b/services/core/java/com/android/server/DiskStatsService.java
index bc12fc5c44e0..93131488f509 100644
--- a/services/core/java/com/android/server/DiskStatsService.java
+++ b/services/core/java/com/android/server/DiskStatsService.java
@@ -21,6 +21,7 @@ import android.os.Binder;
 import android.os.Environment;
 import android.os.StatFs;
 import android.os.SystemClock;
+import android.os.storage.StorageManager;
 
 import java.io.File;
 import java.io.FileDescriptor;
@@ -79,6 +80,10 @@ public class DiskStatsService extends Binder {
         reportFreeSpace(Environment.getDownloadCacheDirectory(), "Cache", pw);
         reportFreeSpace(new File("/system"), "System", pw);
 
+        if (StorageManager.isNativeFileBasedEncryptionEnabled()) {
+            pw.println("File-based Encryption: true");
+        }
+
         // TODO: Read /proc/yaffs and report interesting values;
         // add configurable (through args) performance test parameters.
     }
diff --git a/services/core/java/com/android/server/SystemConfig.java b/services/core/java/com/android/server/SystemConfig.java
index 4dc46ac63643..5aba22d5c4c7 100644
--- a/services/core/java/com/android/server/SystemConfig.java
+++ b/services/core/java/com/android/server/SystemConfig.java
@@ -16,20 +16,24 @@
 
 package com.android.server;
 
+import static com.android.internal.util.ArrayUtils.appendInt;
+
 import android.app.ActivityManager;
 import android.content.pm.FeatureInfo;
-import android.os.*;
+import android.content.pm.PackageManager;
+import android.os.Environment;
 import android.os.Process;
+import android.os.storage.StorageManager;
 import android.util.ArrayMap;
 import android.util.ArraySet;
 import android.util.Slog;
 import android.util.SparseArray;
 import android.util.Xml;
 
-import libcore.io.IoUtils;
-
 import com.android.internal.util.XmlUtils;
 
+import libcore.io.IoUtils;
+
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 
@@ -38,8 +42,6 @@ import java.io.FileNotFoundException;
 import java.io.FileReader;
 import java.io.IOException;
 
-import static com.android.internal.util.ArrayUtils.appendInt;
-
 /**
  * Loads global system configuration info.
  */
@@ -351,10 +353,7 @@ public class SystemConfig {
                         Slog.w(TAG, "<feature> without name in " + permFile + " at "
                                 + parser.getPositionDescription());
                     } else if (allowed) {
-                        //Log.i(TAG, "Got feature " + fname);
-                        FeatureInfo fi = new FeatureInfo();
-                        fi.name = fname;
-                        mAvailableFeatures.put(fname, fi);
+                        addFeature(fname);
                     }
                     XmlUtils.skipCurrentTag(parser);
                     continue;
@@ -443,10 +442,29 @@ public class SystemConfig {
             IoUtils.closeQuietly(permReader);
         }
 
-        for (String fname : mUnavailableFeatures) {
-            if (mAvailableFeatures.remove(fname) != null) {
-                Slog.d(TAG, "Removed unavailable feature " + fname);
-            }
+        // Some devices can be field-converted to FBE, so offer to splice in
+        // those features if not already defined by the static config
+        if (StorageManager.isNativeFileBasedEncryptionEnabled()) {
+            addFeature(PackageManager.FEATURE_FILE_BASED_ENCRYPTION);
+            addFeature(PackageManager.FEATURE_SECURELY_REMOVES_USERS);
+        }
+
+        for (String featureName : mUnavailableFeatures) {
+            removeFeature(featureName);
+        }
+    }
+
+    private void addFeature(String featureName) {
+        if (!mAvailableFeatures.containsKey(featureName)) {
+            final FeatureInfo fi = new FeatureInfo();
+            fi.name = featureName;
+            mAvailableFeatures.put(featureName, fi);
+        }
+    }
+
+    private void removeFeature(String featureName) {
+        if (mAvailableFeatures.remove(featureName) != null) {
+            Slog.d(TAG, "Removed unavailable feature " + featureName);
         }
     }
 
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index d11da792e9d6..c3f20eb8afe1 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -76,6 +76,7 @@ import static android.os.Process.SYSTEM_UID;
 import static android.os.Trace.TRACE_TAG_PACKAGE_MANAGER;
 import static android.system.OsConstants.O_CREAT;
 import static android.system.OsConstants.O_RDWR;
+
 import static com.android.internal.app.IntentForwarderActivity.FORWARD_INTENT_TO_MANAGED_PROFILE;
 import static com.android.internal.app.IntentForwarderActivity.FORWARD_INTENT_TO_PARENT;
 import static com.android.internal.content.NativeLibraryHelper.LIB64_DIR_NAME;