1 /*
2  * Copyright (C) 2010 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 android.mtp;
18 
19 import android.content.Context;
20 import android.content.SharedPreferences;
21 
22 import com.android.internal.util.Preconditions;
23 
24 import libcore.util.HexEncoding;
25 
26 import java.io.FileDescriptor;
27 import java.util.Random;
28 
29 /**
30  * Java wrapper for MTP/PTP support as USB responder.
31  * {@hide}
32  */
33 public class MtpServer implements Runnable {
34 
35     private long mNativeContext; // accessed by native methods
36     private final MtpDatabase mDatabase;
37     private final Runnable mOnTerminate;
38     private final Context mContext;
39 
40 // It requires "exactly 32 characters, including any leading 0s" in MTP spec
41 // (5.1.1.14 Serial Number)
42     private static final int sID_LEN_BYTES = 16;
43     private static final int sID_LEN_STR = (sID_LEN_BYTES * 2);
44 
45     static {
46         System.loadLibrary("media_jni");
47     }
48 
MtpServer( MtpDatabase database, FileDescriptor controlFd, boolean usePtp, Runnable onTerminate, String deviceInfoManufacturer, String deviceInfoModel, String deviceInfoDeviceVersion)49     public MtpServer(
50             MtpDatabase database,
51             FileDescriptor controlFd,
52             boolean usePtp,
53             Runnable onTerminate,
54             String deviceInfoManufacturer,
55             String deviceInfoModel,
56             String deviceInfoDeviceVersion) {
57         mDatabase = Preconditions.checkNotNull(database);
58         mOnTerminate = Preconditions.checkNotNull(onTerminate);
59         mContext = mDatabase.getContext();
60 
61         final String strID_PREFS_NAME = "mtp-cfg";
62         final String strID_PREFS_KEY = "mtp-id";
63         String strRandomId = null;
64         String deviceInfoSerialNumber;
65 
66         SharedPreferences sharedPref =
67                 mContext.getSharedPreferences(strID_PREFS_NAME, Context.MODE_PRIVATE);
68         if (sharedPref.contains(strID_PREFS_KEY)) {
69             strRandomId = sharedPref.getString(strID_PREFS_KEY, null);
70 
71             // Check for format consistence (regenerate upon corruption)
72             if (strRandomId.length() != sID_LEN_STR) {
73                 strRandomId = null;
74             } else {
75                 // Only accept hex digit
76                 for (int ii = 0; ii < strRandomId.length(); ii++)
77                     if (Character.digit(strRandomId.charAt(ii), 16) == -1) {
78                         strRandomId = null;
79                         break;
80                     }
81             }
82         }
83 
84         if (strRandomId == null) {
85             strRandomId = getRandId();
86             sharedPref.edit().putString(strID_PREFS_KEY, strRandomId).apply();
87         }
88 
89         deviceInfoSerialNumber = strRandomId;
90 
91         native_setup(
92                 database,
93                 controlFd,
94                 usePtp,
95                 deviceInfoManufacturer,
96                 deviceInfoModel,
97                 deviceInfoDeviceVersion,
98                 deviceInfoSerialNumber);
99         database.setServer(this);
100     }
101 
getRandId()102     private String getRandId() {
103         Random randomVal = new Random();
104         byte[] randomBytes = new byte[sID_LEN_BYTES];
105 
106         randomVal.nextBytes(randomBytes);
107         return HexEncoding.encodeToString(randomBytes);
108     }
109 
start()110     public void start() {
111         Thread thread = new Thread(this, "MtpServer");
112         thread.start();
113     }
114 
115     @Override
run()116     public void run() {
117         native_run();
118         native_cleanup();
119         mDatabase.close();
120         mOnTerminate.run();
121     }
122 
sendObjectAdded(int handle)123     public void sendObjectAdded(int handle) {
124         native_send_object_added(handle);
125     }
126 
sendObjectRemoved(int handle)127     public void sendObjectRemoved(int handle) {
128         native_send_object_removed(handle);
129     }
130 
sendObjectInfoChanged(int handle)131     public void sendObjectInfoChanged(int handle) {
132         native_send_object_info_changed(handle);
133     }
134 
sendDevicePropertyChanged(int property)135     public void sendDevicePropertyChanged(int property) {
136         native_send_device_property_changed(property);
137     }
138 
addStorage(MtpStorage storage)139     public void addStorage(MtpStorage storage) {
140         native_add_storage(storage);
141     }
142 
removeStorage(MtpStorage storage)143     public void removeStorage(MtpStorage storage) {
144         native_remove_storage(storage.getStorageId());
145     }
146 
configure(boolean usePtp)147     public static void configure(boolean usePtp) {
148         native_configure(usePtp);
149     }
150 
native_configure(boolean usePtp)151     public static native final void native_configure(boolean usePtp);
native_setup( MtpDatabase database, FileDescriptor controlFd, boolean usePtp, String deviceInfoManufacturer, String deviceInfoModel, String deviceInfoDeviceVersion, String deviceInfoSerialNumber)152     private native final void native_setup(
153             MtpDatabase database,
154             FileDescriptor controlFd,
155             boolean usePtp,
156             String deviceInfoManufacturer,
157             String deviceInfoModel,
158             String deviceInfoDeviceVersion,
159             String deviceInfoSerialNumber);
native_run()160     private native final void native_run();
native_cleanup()161     private native final void native_cleanup();
native_send_object_added(int handle)162     private native final void native_send_object_added(int handle);
native_send_object_removed(int handle)163     private native final void native_send_object_removed(int handle);
native_send_object_info_changed(int handle)164     private native final void native_send_object_info_changed(int handle);
native_send_device_property_changed(int property)165     private native final void native_send_device_property_changed(int property);
native_add_storage(MtpStorage storage)166     private native final void native_add_storage(MtpStorage storage);
native_remove_storage(int storageId)167     private native final void native_remove_storage(int storageId);
168 }
169