1 /*
2  * Copyright (C) 2020 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 #pragma once
18 
19 #include <android-base/macros.h>
20 #include <android/hardware/automotive/can/1.0/ICanBus.h>
21 #include <libprotocan/MessageCounter.h>
22 #include <libprotocan/MessageDef.h>
23 #include <utils/Mutex.h>
24 
25 #include <mutex>
26 #include <queue>
27 
28 namespace android::hardware::automotive::protocan {
29 
30 class MessageInjectorManager;
31 
32 /**
33  * Injects CAN messages with a counter to an existing system.
34  *
35  * This class is NOT meant to use in production - there should be no need to inject counted CAN
36  * messages where the other sender is also broadcasting them. If this is the case, it may be a sign
37  * your CAN network needs a redesign. This tool is intended for use for testing and demo purposes.
38  */
39 class MessageInjector {
40  public:
41   MessageInjector(MessageDef msgDef, std::optional<std::chrono::milliseconds> interMessageDelay);
42 
43   void inject(const can::V1_0::CanMessage& msg);
44   void inject(const std::initializer_list<can::V1_0::CanMessage> msgs);
45 
46  private:
47   const MessageDef kMsgDef;
48   const std::optional<std::chrono::milliseconds> kInterMessageDelay;
49   MessageCounter mCounter;
50 
51   mutable std::mutex mMessagesGuard;
52   std::queue<can::V1_0::CanMessage> mMessages GUARDED_BY(mMessagesGuard);
53 
54   void onReceive(can::V1_0::ICanBus& bus, const can::V1_0::CanMessage& msg);
55   void processQueueLocked(can::V1_0::ICanBus& bus);
56 
57   friend class MessageInjectorManager;
58 
59   DISALLOW_COPY_AND_ASSIGN(MessageInjector);
60 };
61 
62 /**
63  * Routes intercepted messages to MessageInjector instances configured to handle specific CAN
64  * message (CAN message ID). Intercepted messages from other nodes in CAN network are used to read
65  * current counter value in order to spoof the next packet.
66  */
67 class MessageInjectorManager {
68  public:
69   MessageInjectorManager(std::initializer_list<std::shared_ptr<MessageInjector>> injectors);
70 
71   void onReceive(sp<can::V1_0::ICanBus> bus, const can::V1_0::CanMessage& msg);
72 
73  private:
74   std::map<can::V1_0::CanMessageId, std::shared_ptr<MessageInjector>> mInjectors;
75 
76   DISALLOW_COPY_AND_ASSIGN(MessageInjectorManager);
77 };
78 
79 }  // namespace android::hardware::automotive::protocan
80