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_Unguarded();
43   bool IsConnected();
44   bool DataAvailable();
45   int32_t Read();
46   bool Read(std::vector<char>& data);
47   std::vector<char> Read(size_t size);
48   std::future<std::vector<char>> ReadAsync(size_t size);
49 
50   bool ReadMessage(std::vector<char>& data);
51   std::vector<char> ReadMessage();
52   std::future<std::vector<char>> ReadMessageAsync();
53   Json::Value ReadJsonMessage();
54   std::future<Json::Value> ReadJsonMessageAsync();
55 
56   bool Write(int32_t data);
57   bool Write(const char* data, unsigned int size);
58   bool Write(const std::vector<char>& data);
59   bool WriteMessage(const std::string& data);
60   bool WriteMessage(const std::vector<char>& data);
61   bool WriteMessage(const Json::Value& data);
62   bool WriteStrides(const char* data, unsigned int size,
63                     unsigned int num_strides, int stride_size);
64 
65  protected:
66   std::recursive_mutex read_mutex_;
67   std::recursive_mutex write_mutex_;
68   std::function<void()> disconnect_callback_;
69   SharedFD fd_;
70 };
71 
72 class VsockClientConnection : public VsockConnection {
73  public:
74   // the value of vhost_user_vsock_cid isn't actually used, it works like bool,
75   // so any value except nullopt means true
76   bool Connect(unsigned int port, unsigned int cid,
77                std::optional<int> vhost_user) override;
78 };
79 
80 class VsockServerConnection : public VsockConnection {
81  public:
82   virtual ~VsockServerConnection();
83   void ServerShutdown();
84   bool Connect(unsigned int port, unsigned int cid,
85                std::optional<int> vhost_user_vsock_cid) override;
86 
87  private:
88   SharedFD server_fd_;
89 };
90 
91 }  // namespace cuttlefish
92