| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.server.usb; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.content.Context; |
| import android.content.pm.PackageInfo; |
| import android.content.pm.PackageManager; |
| import android.hardware.usb.IUsbSerialReader; |
| import android.hardware.usb.UsbAccessory; |
| import android.hardware.usb.UsbDevice; |
| import android.os.Binder; |
| import android.os.Build; |
| import android.os.Process; |
| import android.os.RemoteException; |
| import android.os.UserHandle; |
| |
| import com.android.internal.util.ArrayUtils; |
| |
| /** |
| * Allows an app to read the serial number of the {@link UsbDevice}/{@link UsbAccessory} only if |
| * the app has got the permission to do so. |
| */ |
| class UsbSerialReader extends IUsbSerialReader.Stub { |
| private final @Nullable String mSerialNumber; |
| private final @NonNull Context mContext; |
| private final @NonNull UsbPermissionManager mPermissionManager; |
| |
| private Object mDevice; |
| |
| /** |
| * Create an new {@link UsbSerialReader}. It is mandatory to call {@link #setDevice(Object)} |
| * immediately after this. |
| * |
| * @param context A context to be used by the reader |
| * @param settingsManager The USB settings manager |
| * @param serialNumber The serial number that might be read |
| */ |
| UsbSerialReader(@NonNull Context context, @NonNull UsbPermissionManager permissionManager, |
| @Nullable String serialNumber) { |
| mContext = context; |
| mPermissionManager = permissionManager; |
| mSerialNumber = serialNumber; |
| } |
| |
| /** |
| * Set the {@link UsbDevice}/{@link UsbAccessory} the serial number belongs to |
| * |
| * @param device The device/accessory |
| */ |
| public void setDevice(@NonNull Object device) { |
| mDevice = device; |
| } |
| |
| @Override |
| public String getSerial(String packageName) throws RemoteException { |
| int pid = Binder.getCallingPid(); |
| int uid = Binder.getCallingUid(); |
| |
| if (uid != Process.SYSTEM_UID) { |
| enforcePackageBelongsToUid(uid, packageName); |
| |
| UserHandle user = Binder.getCallingUserHandle(); |
| int packageTargetSdkVersion; |
| long token = Binder.clearCallingIdentity(); |
| try { |
| PackageInfo pkg; |
| try { |
| pkg = mContext.getPackageManager() |
| .getPackageInfoAsUser(packageName, 0, user.getIdentifier()); |
| } catch (PackageManager.NameNotFoundException e) { |
| throw new RemoteException("package " + packageName + " cannot be found"); |
| } |
| packageTargetSdkVersion = pkg.applicationInfo.targetSdkVersion; |
| |
| if (packageTargetSdkVersion >= Build.VERSION_CODES.Q) { |
| if (mContext.checkPermission(android.Manifest.permission.MANAGE_USB, pid, uid) |
| == PackageManager.PERMISSION_DENIED) { |
| |
| int userId = UserHandle.getUserId(uid); |
| if (mDevice instanceof UsbDevice) { |
| mPermissionManager.getPermissionsForUser(userId) |
| .checkPermission((UsbDevice) mDevice, packageName, pid, uid); |
| } else { |
| mPermissionManager.getPermissionsForUser(userId) |
| .checkPermission((UsbAccessory) mDevice, uid); |
| } |
| } |
| } |
| } finally { |
| Binder.restoreCallingIdentity(token); |
| } |
| } |
| |
| return mSerialNumber; |
| } |
| |
| private void enforcePackageBelongsToUid(int uid, @NonNull String packageName) { |
| String[] packages = mContext.getPackageManager().getPackagesForUid(uid); |
| |
| if (!ArrayUtils.contains(packages, packageName)) { |
| throw new IllegalArgumentException(packageName + " does to belong to the " + uid); |
| } |
| } |
| } |