1 /*
2  * Copyright (C) 2021 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 #pragma once
17 
18 #include <cstddef>
19 #include <cstdint>
20 #include <functional>
21 #include <future>
22 #include <mutex>
23 #include <string>
24 #include <vector>
25 
26 #include <json/json.h>
27 
28 #include "common/libs/fs/shared_fd.h"
29 
30 namespace cuttlefish {
31 
32 class VsockConnection {
33  public:
34   virtual ~VsockConnection();
35   virtual bool Connect(unsigned int port, unsigned int cid,
36                        std::optional<int> vhost_user_vsock_cid) = 0;
37   virtual void Disconnect();
38   std::future<bool> ConnectAsync(unsigned int port, unsigned int cid,
39                                  std::optional<int> vhost_user_vsock_cid);
40   void SetDisconnectCallback(std::function<void()> callback);
41 
42   bool IsConnected();
43   bool DataAvailable();
44   int32_t Read();
45   bool Read(std::vector<char>& data);
46   std::vector<char> Read(size_t size);
47   std::future<std::vector<char>> ReadAsync(size_t size);
48 
49   bool ReadMessage(std::vector<char>& data);
50   std::vector<char> ReadMessage();
51   std::future<std::vector<char>> ReadMessageAsync();
52   Json::Value ReadJsonMessage();
53   std::future<Json::Value> ReadJsonMessageAsync();
54 
55   bool Write(int32_t data);
56   bool Write(const char* data, unsigned int size);
57   bool Write(const std::vector<char>& data);
58   bool WriteMessage(const std::string& data);
59   bool WriteMessage(const std::vector<char>& data);
60   bool WriteMessage(const Json::Value& data);
61   bool WriteStrides(const char* data, unsigned int size,
62                     unsigned int num_strides, int stride_size);
63 
64  protected:
65   std::recursive_mutex read_mutex_;
66   std::recursive_mutex write_mutex_;
67   std::function<void()> disconnect_callback_;
68   SharedFD fd_;
69 };
70 
71 class VsockClientConnection : public VsockConnection {
72  public:
73   // the value of vhost_user_vsock_cid isn't actually used, it works like bool,
74   // so any value except nullopt means true
75   bool Connect(unsigned int port, unsigned int cid,
76                std::optional<int> vhost_user) override;
77 };
78 
79 class VsockServerConnection : public VsockConnection {
80  public:
81   virtual ~VsockServerConnection();
82   void ServerShutdown();
83   bool Connect(unsigned int port, unsigned int cid,
84                std::optional<int> vhost_user_vsock_cid) override;
85 
86  private:
87   SharedFD server_fd_;
88 };
89 
90 }  // namespace cuttlefish
91