Prevent users from mounting USB, if restricted.

Bug: 13585295

Change-Id: I6b7905fad06bf2e1d4dd629a266280ddff9b3121

2 files changed, 22 insertions, 1 deletions

diff --git a/services/usb/java/com/android/server/usb/UsbDeviceManager.java b/services/usb/java/com/android/server/usb/UsbDeviceManager.java
index 6822ee3..5233297 100644
--- a/services/usb/java/com/android/server/usb/UsbDeviceManager.java
+++ b/services/usb/java/com/android/server/usb/UsbDeviceManager.java
@@ -39,6 +39,7 @@ import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.os.UEventObserver;
 import android.os.UserHandle;
+import android.os.UserManager;
 import android.os.storage.StorageManager;
 import android.os.storage.StorageVolume;
 import android.provider.Settings;
@@ -655,6 +656,17 @@ public class UsbDeviceManager {
                     }
                     break;
                 case MSG_USER_SWITCHED: {
+                    mCurrentUser = msg.arg1;
+
+                    UserManager userManager =
+                            (UserManager) mContext.getSystemService(Context.USER_SERVICE);
+                    if (userManager.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {
+                        Slog.v(TAG, "Switched to user with DISALLOW_USB_FILE_TRANSFER restriction;"
+                                + " disabling USB.");
+                        setUsbConfig("none");
+                        break;
+                    }
+
                     final boolean mtpActive =
                             containsFunction(mCurrentFunctions, UsbManager.USB_FUNCTION_MTP)
                             || containsFunction(mCurrentFunctions, UsbManager.USB_FUNCTION_PTP);
@@ -663,7 +675,6 @@ public class UsbDeviceManager {
                         setUsbConfig("none");
                         setUsbConfig(mCurrentFunctions);
                     }
-                    mCurrentUser = msg.arg1;
                     break;
                 }
             }
diff --git a/services/usb/java/com/android/server/usb/UsbService.java b/services/usb/java/com/android/server/usb/UsbService.java
index b6ae192..fd83f92 100644
--- a/services/usb/java/com/android/server/usb/UsbService.java
+++ b/services/usb/java/com/android/server/usb/UsbService.java
@@ -28,6 +28,7 @@ import android.hardware.usb.UsbDevice;
 import android.os.Bundle;
 import android.os.ParcelFileDescriptor;
 import android.os.UserHandle;
+import android.os.UserManager;
 import android.util.SparseArray;
 
 import com.android.internal.annotations.GuardedBy;
@@ -248,6 +249,15 @@ public class UsbService extends IUsbManager.Stub {
     @Override
     public void setCurrentFunction(String function, boolean makeDefault) {
         mContext.enforceCallingOrSelfPermission(android.Manifest.permission.MANAGE_USB, null);
+
+        // If attempt to change USB function while file transfer is restricted, ensure that
+        // the current function is set to "none", and return.
+        UserManager userManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
+        if (userManager.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {
+            if (mDeviceManager != null) mDeviceManager.setCurrentFunctions("none", false);
+            return;
+        }
+
         if (mDeviceManager != null) {
             mDeviceManager.setCurrentFunctions(function, makeDefault);
         } else {