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 #ifndef android_hardware_automotive_vehicle_V2_0_impl_SocketComm_H_
18 #define android_hardware_automotive_vehicle_V2_0_impl_SocketComm_H_
19 
20 #include <mutex>
21 #include <thread>
22 #include <vector>
23 #include "CommConn.h"
24 
25 namespace android {
26 namespace hardware {
27 namespace automotive {
28 namespace vehicle {
29 namespace V2_0 {
30 
31 namespace impl {
32 
33 class SocketConn;
34 
35 /**
36  * SocketComm opens a socket, and listens for connections from clients. Typically the client will be
37  * adb's TCP port-forwarding to enable a host PC to connect to the VehicleHAL.
38  */
39 class SocketComm {
40    public:
41     SocketComm(MessageProcessor* messageProcessor);
42     virtual ~SocketComm();
43 
44     void start();
45     void stop();
46 
47     /**
48      * Serialized and send the given message to all connected clients.
49      */
50     void sendMessage(vhal_proto::EmulatorMessage const& msg);
51 
52    private:
53     int mListenFd;
54     std::unique_ptr<std::thread> mListenThread;
55     std::vector<std::unique_ptr<SocketConn>> mOpenConnections;
56     MessageProcessor* mMessageProcessor;
57     std::mutex mMutex;
58 
59     /**
60      * Opens the socket and begins listening.
61      *
62      * @return bool Returns true on success.
63      */
64     bool listen();
65 
66     /**
67      * Blocks and waits for a connection from a client, returns a new SocketConn with the connection
68      * or null, if the connection has been closed.
69      *
70      * @return int Returns fd or socket number if connection is successful.
71      *              Otherwise, returns -1 if no connection is availble.
72      */
73     SocketConn* accept();
74 
75     void listenThread();
76 
77     void removeClosedConnections();
78 };
79 
80 /**
81  * SocketConn represents a single connection to a client.
82  */
83 class SocketConn : public CommConn {
84    public:
85     SocketConn(MessageProcessor* messageProcessor, int sfd);
86     virtual ~SocketConn() = default;
87 
88     /**
89      * Blocking call to read data from the connection.
90      *
91      * @return std::vector<uint8_t> Serialized protobuf data received from emulator.  This will be
92      *              an empty vector if the connection was closed or some other error occurred.
93      */
94     std::vector<uint8_t> read() override;
95 
96     /**
97      * Closes a connection if it is open.
98      */
99     void stop() override;
100 
101     /**
102      * Transmits a string of data to the emulator.
103      *
104      * @param data Serialized protobuf data to transmit.
105      *
106      * @return int Number of bytes transmitted, or -1 if failed.
107      */
108     int write(const std::vector<uint8_t>& data) override;
109 
isOpen()110     inline bool isOpen() override { return mSockFd > 0; }
111 
112    private:
113     int mSockFd;
114 };
115 
116 }  // impl
117 
118 }  // namespace V2_0
119 }  // namespace vehicle
120 }  // namespace automotive
121 }  // namespace hardware
122 }  // namespace android
123 
124 
125 #endif  // android_hardware_automotive_vehicle_V2_0_impl_SocketComm_H_
126