Do not access MTP devices when disabled.

am: 5201f1e61c

Change-Id: I9aa036678f2677054666b137533e61eaeac88159

core/java/android/hardware/usb/UsbDeviceConnection.java

@@ -16,8 +16,10 @@
 
 package android.hardware.usb;
 
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
 import android.os.ParcelFileDescriptor;
-
 import java.io.FileDescriptor;
 
 
@@ -31,6 +33,8 @@ public class UsbDeviceConnection {
 
     private final UsbDevice mDevice;
 
+    private Context mContext;
+
     // used by the JNI code
     private long mNativeContext;
 
@@ -42,10 +46,21 @@ public class UsbDeviceConnection {
         mDevice = device;
     }
 
-    /* package */ boolean open(String name, ParcelFileDescriptor pfd) {
+    /* package */ boolean open(String name, ParcelFileDescriptor pfd,  @NonNull Context context) {
+        mContext = context.getApplicationContext();
+
         return native_open(name, pfd.getFileDescriptor());
     }
 
+    /**
+     * @return The application context the connection was created for.
+     *
+     * @hide
+     */
+    public @Nullable Context getContext() {
+        return mContext;
+    }
+
     /**
      * Releases all system resources related to the device.
      * Once the object is closed it cannot be used again.

core/java/android/hardware/usb/UsbManager.java

@@ -330,7 +330,7 @@ public class UsbManager {
             ParcelFileDescriptor pfd = mService.openDevice(deviceName);
             if (pfd != null) {
                 UsbDeviceConnection connection = new UsbDeviceConnection(device);
-                boolean result = connection.open(deviceName, pfd);
+                boolean result = connection.open(deviceName, pfd, mContext);
                 pfd.close();
                 if (result) {
                     return connection;

media/java/android/mtp/MtpDevice.java

@@ -18,11 +18,13 @@ package android.mtp;
 
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.content.Context;
 import android.hardware.usb.UsbDevice;
 import android.hardware.usb.UsbDeviceConnection;
 import android.os.CancellationSignal;
 import android.os.ParcelFileDescriptor;
 
+import android.os.UserManager;
 import com.android.internal.util.Preconditions;
 
 import java.io.IOException;
@@ -62,7 +64,17 @@ public final class MtpDevice {
      * @return true if the device was successfully opened.
      */
     public boolean open(UsbDeviceConnection connection) {
-        boolean result = native_open(mDevice.getDeviceName(), connection.getFileDescriptor());
+        boolean result = false;
+
+        Context context = connection.getContext();
+        if (context != null) {
+            UserManager userManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
+
+            if (!userManager.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {
+                result = native_open(mDevice.getDeviceName(), connection.getFileDescriptor());
+            }
+        }
+
         if (!result) {
             connection.close();
         }

services/core/java/com/android/server/MountService.java

@@ -1437,13 +1437,22 @@ class MountService extends IMountService.Stub
      * Decide if volume is mountable per device policies.
      */
     private boolean isMountDisallowed(VolumeInfo vol) {
-        if (vol.type == VolumeInfo.TYPE_PUBLIC || vol.type == VolumeInfo.TYPE_PRIVATE) {
-            final UserManager userManager = mContext.getSystemService(UserManager.class);
-            return userManager.hasUserRestriction(UserManager.DISALLOW_MOUNT_PHYSICAL_MEDIA,
+        UserManager userManager = mContext.getSystemService(UserManager.class);
+
+        boolean isUsbRestricted = false;
+        if (vol.disk != null && vol.disk.isUsb()) {
+            isUsbRestricted = userManager.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER,
                     Binder.getCallingUserHandle());
-        } else {
-            return false;
         }
+
+        boolean isTypeRestricted = false;
+        if (vol.type == VolumeInfo.TYPE_PUBLIC || vol.type == VolumeInfo.TYPE_PRIVATE) {
+            isTypeRestricted = userManager
+                    .hasUserRestriction(UserManager.DISALLOW_MOUNT_PHYSICAL_MEDIA,
+                    Binder.getCallingUserHandle());
+        }
+
+        return isUsbRestricted || isTypeRestricted;
     }
 
     private void enforceAdminUser() {