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1 #ifndef ANDROID_PDX_UDS_SERVICE_ENDPOINT_H_
2 #define ANDROID_PDX_UDS_SERVICE_ENDPOINT_H_
3 
4 #include <sys/stat.h>
5 #include <map>
6 #include <memory>
7 #include <mutex>
8 #include <string>
9 #include <unordered_map>
10 #include <utility>
11 #include <vector>
12 
13 #include <pdx/service.h>
14 #include <pdx/service_endpoint.h>
15 #include <uds/channel_event_set.h>
16 
17 namespace android {
18 namespace pdx {
19 namespace uds {
20 
21 class Endpoint : public pdx::Endpoint {
22  public:
23   enum {
24     kIpcTag = 0x00736674,  // 'uds'
25   };
26 
27   // Blocking modes for service endpoint. Controls whether the epoll set is in
28   // blocking mode or not for message receive.
29   enum {
30     kBlocking = true,
31     kNonBlocking = false,
32     kDefaultBlocking = kNonBlocking,
33   };
34 
35   enum : mode_t {
36     kDefaultMode = 0,
37   };
38 
39   ~Endpoint() override = default;
40 
GetIpcTag()41   uint32_t GetIpcTag() const override { return kIpcTag; }
42   Status<void> SetService(Service* service) override;
43   Status<void> SetChannel(int channel_id, Channel* channel) override;
44   Status<void> CloseChannel(int channel_id) override;
45   Status<void> ModifyChannelEvents(int channel_id, int clear_mask,
46                                    int set_mask) override;
47   Status<RemoteChannelHandle> PushChannel(Message* message, int flags,
48                                           Channel* channel,
49                                           int* channel_id) override;
50   Status<int> CheckChannel(const Message* message, ChannelReference ref,
51                            Channel** channel) override;
52   Status<void> MessageReceive(Message* message) override;
53   Status<void> MessageReply(Message* message, int return_code) override;
54   Status<void> MessageReplyFd(Message* message, unsigned int push_fd) override;
55   Status<void> MessageReplyChannelHandle(
56       Message* message, const LocalChannelHandle& handle) override;
57   Status<void> MessageReplyChannelHandle(
58       Message* message, const BorrowedChannelHandle& handle) override;
59   Status<void> MessageReplyChannelHandle(
60       Message* message, const RemoteChannelHandle& handle) override;
61   Status<size_t> ReadMessageData(Message* message, const iovec* vector,
62                                  size_t vector_length) override;
63   Status<size_t> WriteMessageData(Message* message, const iovec* vector,
64                                   size_t vector_length) override;
65   Status<FileReference> PushFileHandle(Message* message,
66                                        const LocalHandle& handle) override;
67   Status<FileReference> PushFileHandle(Message* message,
68                                        const BorrowedHandle& handle) override;
69   Status<FileReference> PushFileHandle(Message* message,
70                                        const RemoteHandle& handle) override;
71   Status<ChannelReference> PushChannelHandle(
72       Message* message, const LocalChannelHandle& handle) override;
73   Status<ChannelReference> PushChannelHandle(
74       Message* message, const BorrowedChannelHandle& handle) override;
75   Status<ChannelReference> PushChannelHandle(
76       Message* message, const RemoteChannelHandle& handle) override;
77   LocalHandle GetFileHandle(Message* message, FileReference ref) const override;
78   LocalChannelHandle GetChannelHandle(Message* message,
79                                       ChannelReference ref) const override;
80 
81   void* AllocateMessageState() override;
82   void FreeMessageState(void* state) override;
83 
84   Status<void> Cancel() override;
85 
86   // Open an endpoint at the given path.
87   // Second parameter is unused for UDS, but we have it here for compatibility
88   // in signature with servicefs::Endpoint::Create().
89   // This method uses |endpoint_path| as a relative path to endpoint socket
90   // created by init process.
91   static std::unique_ptr<Endpoint> Create(const std::string& endpoint_path,
92                                           mode_t /*unused_mode*/ = kDefaultMode,
93                                           bool blocking = kDefaultBlocking);
94 
95   // Helper method to create an endpoint at the given UDS socket path. This
96   // method physically creates and binds a socket at that path.
97   static std::unique_ptr<Endpoint> CreateAndBindSocket(
98       const std::string& endpoint_path, bool blocking = kDefaultBlocking);
99 
100   // Helper method to create an endpoint from an existing socket FD.
101   // Mostly helpful for tests.
102   static std::unique_ptr<Endpoint> CreateFromSocketFd(LocalHandle socket_fd);
103 
104   // Test helper method to register a new channel identified by |channel_fd|
105   // socket file descriptor.
106   Status<void> RegisterNewChannelForTests(LocalHandle channel_fd);
107 
epoll_fd()108   int epoll_fd() const override { return epoll_fd_.Get(); }
109 
110  private:
111   struct ChannelData {
112     LocalHandle data_fd;
113     ChannelEventSet event_set;
114     Channel* channel_state{nullptr};
115   };
116 
117   // This class must be instantiated using Create() static methods above.
118   Endpoint(const std::string& endpoint_path, bool blocking,
119            bool use_init_socket_fd = true);
120   Endpoint(LocalHandle socket_fd);
121 
122   void Init(LocalHandle socket_fd);
123 
124   Endpoint(const Endpoint&) = delete;
125   void operator=(const Endpoint&) = delete;
126 
GetNextAvailableMessageId()127   uint32_t GetNextAvailableMessageId() {
128     return next_message_id_.fetch_add(1, std::memory_order_relaxed);
129   }
130 
131   void BuildCloseMessage(int32_t channel_id, Message* message);
132 
133   Status<void> AcceptConnection(Message* message);
134   Status<void> ReceiveMessageForChannel(const BorrowedHandle& channel_fd,
135                                         Message* message);
136   Status<void> OnNewChannel(LocalHandle channel_fd);
137   Status<std::pair<int32_t, ChannelData*>> OnNewChannelLocked(
138       LocalHandle channel_fd, Channel* channel_state);
139   Status<void> CloseChannelLocked(int32_t channel_id);
140   Status<void> ReenableEpollEvent(const BorrowedHandle& channel_fd);
141   Channel* GetChannelState(int32_t channel_id);
142   BorrowedHandle GetChannelSocketFd(int32_t channel_id);
143   Status<std::pair<BorrowedHandle, BorrowedHandle>> GetChannelEventFd(
144       int32_t channel_id);
145   int32_t GetChannelId(const BorrowedHandle& channel_fd);
146   Status<void> CreateChannelSocketPair(LocalHandle* local_socket,
147                                        LocalHandle* remote_socket);
148 
149   std::string endpoint_path_;
150   bool is_blocking_;
151   LocalHandle socket_fd_;
152   LocalHandle cancel_event_fd_;
153   LocalHandle epoll_fd_;
154 
155   mutable std::mutex channel_mutex_;
156   std::map<int32_t, ChannelData> channels_;
157   std::map<int, int32_t> channel_fd_to_id_;
158   int32_t last_channel_id_{0};
159 
160   Service* service_{nullptr};
161   std::atomic<uint32_t> next_message_id_;
162 };
163 
164 }  // namespace uds
165 }  // namespace pdx
166 }  // namespace android
167 
168 #endif  // ANDROID_PDX_UDS_PDX_SERVICE_ENDPOINT_H_
169