am 5c8e1a6e: Merge "Allow PMS to restorecon directories under /data."

* commit '5c8e1a6ed4b7e12632c7c82b94e1909ae82b0706':
  Allow PMS to restorecon directories under /data.

3 files changed, 108 insertions, 0 deletions

diff --git a/services/java/com/android/server/pm/Installer.java b/services/java/com/android/server/pm/Installer.java
index 54acda2a7dba..4b087ccdd8b3 100644
--- a/services/java/com/android/server/pm/Installer.java
+++ b/services/java/com/android/server/pm/Installer.java
@@ -396,4 +396,8 @@ public final class Installer {
 
         return execute(builder.toString());
     }
+
+    public boolean restoreconData() {
+        return (execute("restorecondata") == 0);
+    }
 }
diff --git a/services/java/com/android/server/pm/PackageManagerService.java b/services/java/com/android/server/pm/PackageManagerService.java
index 1bac1db4bd7b..5dded5773067 100755
--- a/services/java/com/android/server/pm/PackageManagerService.java
+++ b/services/java/com/android/server/pm/PackageManagerService.java
@@ -1486,6 +1486,13 @@ public class PackageManagerService extends IPackageManager.Stub {
             // can downgrade to reader
             mSettings.writeLPr();
 
+            if (SELinuxMMAC.shouldRestorecon()) {
+                Slog.i(TAG, "Relabeling of /data/data and /data/user issued.");
+                if (mInstaller.restoreconData()) {
+                    SELinuxMMAC.setRestoreconDone();
+                }
+            }
+
             EventLog.writeEvent(EventLogTags.BOOT_PROGRESS_PMS_READY,
                     SystemClock.uptimeMillis());
 
diff --git a/services/java/com/android/server/pm/SELinuxMMAC.java b/services/java/com/android/server/pm/SELinuxMMAC.java
index 1d68afa546e8..91de6d80ca8b 100644
--- a/services/java/com/android/server/pm/SELinuxMMAC.java
+++ b/services/java/com/android/server/pm/SELinuxMMAC.java
@@ -25,11 +25,16 @@ import android.util.Xml;
 
 import com.android.internal.util.XmlUtils;
 
+import libcore.io.IoUtils;
+
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
 import java.io.FileReader;
 import java.io.IOException;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
 import java.util.HashMap;
 
@@ -60,6 +65,13 @@ public final class SELinuxMMAC {
         new File(Environment.getRootDirectory(), "etc/security/mac_permissions.xml"),
         null};
 
+    // Location of seapp_contexts policy file.
+    private static final String SEAPP_CONTEXTS_FILE = "/seapp_contexts";
+
+    // Stores the hash of the last used seapp_contexts file.
+    private static final String SEAPP_HASH_FILE =
+            Environment.getDataDirectory().toString() + "/system/seapp_hash";
+
     // Signature policy stanzas
     static class Policy {
         private String seinfo;
@@ -391,4 +403,89 @@ public final class SELinuxMMAC {
 
         return (sDefaultSeinfo != null);
     }
+
+    /**
+     * Determines if a recursive restorecon on /data/data and /data/user is needed.
+     * It does this by comparing the SHA-1 of the seapp_contexts file against the
+     * stored hash at /data/system/seapp_hash.
+     *
+     * @return Returns true if the restorecon should occur or false otherwise.
+     */
+    public static boolean shouldRestorecon() {
+        // Any error with the seapp_contexts file should be fatal
+        byte[] currentHash = null;
+        try {
+            currentHash = returnHash(SEAPP_CONTEXTS_FILE);
+        } catch (IOException ioe) {
+            Slog.e(TAG, "Error with hashing seapp_contexts.", ioe);
+            return false;
+        }
+
+        // Push past any error with the stored hash file
+        byte[] storedHash = null;
+        try {
+            storedHash = IoUtils.readFileAsByteArray(SEAPP_HASH_FILE);
+        } catch (IOException ioe) {
+            Slog.e(TAG, "Error opening " + SEAPP_HASH_FILE + ". Assuming first boot.", ioe);
+        }
+
+        return (storedHash == null || !MessageDigest.isEqual(storedHash, currentHash));
+    }
+
+    /**
+     * Stores the SHA-1 of the seapp_contexts to /data/system/seapp_hash.
+     */
+    public static void setRestoreconDone() {
+        try {
+            final byte[] currentHash = returnHash(SEAPP_CONTEXTS_FILE);
+            dumpHash(new File(SEAPP_HASH_FILE), currentHash);
+        } catch (IOException ioe) {
+            Slog.e(TAG, "Error with saving hash to " + SEAPP_HASH_FILE, ioe);
+        }
+    }
+
+    /**
+     * Dump the contents of a byte array to a specified file.
+     *
+     * @param file The file that receives the byte array content.
+     * @param content A byte array that will be written to the specified file.
+     * @throws IOException if any failed I/O operation occured.
+     *         Included is the failure to atomically rename the tmp
+     *         file used in the process.
+     */
+    private static void dumpHash(File file, byte[] content) throws IOException {
+        FileOutputStream fos = null;
+        File tmp = null;
+        try {
+            tmp = File.createTempFile("seapp_hash", ".journal", file.getParentFile());
+            tmp.setReadable(true);
+            fos = new FileOutputStream(tmp);
+            fos.write(content);
+            fos.getFD().sync();
+            if (!tmp.renameTo(file)) {
+                throw new IOException("Failure renaming " + file.getCanonicalPath());
+            }
+        } finally {
+            if (tmp != null) {
+                tmp.delete();
+            }
+            IoUtils.closeQuietly(fos);
+        }
+    }
+
+    /**
+     * Return the SHA-1 of a file.
+     *
+     * @param file The path to the file given as a string.
+     * @return Returns the SHA-1 of the file as a byte array.
+     * @throws IOException if any failed I/O operations occured.
+     */
+    private static byte[] returnHash(String file) throws IOException {
+        try {
+            final byte[] contents = IoUtils.readFileAsByteArray(file);
+            return MessageDigest.getInstance("SHA-1").digest(contents);
+        } catch (NoSuchAlgorithmException nsae) {
+            throw new RuntimeException(nsae);  // impossible
+        }
+    }
 }