1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.internal.car;
18 
19 import android.content.ComponentName;
20 import android.content.Context;
21 import android.content.Intent;
22 import android.content.ServiceConnection;
23 import android.os.Binder;
24 import android.os.IBinder;
25 import android.os.Parcel;
26 import android.os.RemoteException;
27 import android.os.UserHandle;
28 import android.util.Slog;
29 
30 import com.android.server.SystemService;
31 import com.android.internal.car.ICarServiceHelper;
32 
33 /**
34  * System service side companion service for CarService.
35  * Starts car service and provide necessary API for CarService. Only for car product.
36  */
37 public class CarServiceHelperService extends SystemService {
38     private static final String TAG = "CarServiceHelper";
39     private static final String CAR_SERVICE_INTERFACE = "android.car.ICar";
40     private final ICarServiceHelperImpl mHelper = new ICarServiceHelperImpl();
41     private final Context mContext;
42     private IBinder mCarService;
43     private final ServiceConnection mCarServiceConnection = new ServiceConnection() {
44 
45         @Override
46         public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
47             Slog.i(TAG, "**CarService connected**");
48             mCarService = iBinder;
49             // Cannot depend on ICar which is defined in CarService, so handle binder call directly
50             // instead.
51             // void setCarServiceHelper(in IBinder helper)
52             Parcel data = Parcel.obtain();
53             data.writeInterfaceToken(CAR_SERVICE_INTERFACE);
54             data.writeStrongBinder(mHelper.asBinder());
55             try {
56                 mCarService.transact(IBinder.FIRST_CALL_TRANSACTION, // setCarServiceHelper
57                         data, null, Binder.FLAG_ONEWAY);
58             } catch (RemoteException e) {
59                 Slog.w(TAG, "RemoteException from car service", e);
60                 handleCarServiceCrash();
61             }
62         }
63 
64         @Override
65         public void onServiceDisconnected(ComponentName componentName) {
66             handleCarServiceCrash();
67         }
68     };
69 
CarServiceHelperService(Context context)70     public CarServiceHelperService(Context context) {
71         super(context);
72         mContext = context;
73     }
74 
75     @Override
onStart()76     public void onStart() {
77         Intent intent = new Intent();
78         intent.setPackage("com.android.car");
79         intent.setAction(CAR_SERVICE_INTERFACE);
80         if (!getContext().bindServiceAsUser(intent, mCarServiceConnection, Context.BIND_AUTO_CREATE,
81                 UserHandle.SYSTEM)) {
82             Slog.wtf(TAG, "cannot start car service");
83         }
84         System.loadLibrary("car-framework-service-jni");
85     }
86 
handleCarServiceCrash()87     private void handleCarServiceCrash() {
88         //TODO define recovery bahavior
89     }
90 
nativeForceSuspend(int timeoutMs)91     private static native int nativeForceSuspend(int timeoutMs);
92 
93     private class ICarServiceHelperImpl extends ICarServiceHelper.Stub {
94        /**
95          * Force device to suspend
96          *
97          * @param timeoutMs
98          */
99         @Override // Binder call
forceSuspend(int timeoutMs)100         public int forceSuspend(int timeoutMs) {
101             int retVal;
102             mContext.enforceCallingOrSelfPermission(android.Manifest.permission.DEVICE_POWER, null);
103             final long ident = Binder.clearCallingIdentity();
104             try {
105                 retVal = nativeForceSuspend(timeoutMs);
106             } finally {
107                 Binder.restoreCallingIdentity(ident);
108             }
109             return retVal;
110         }
111     }
112 }
113