| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| #pragma once |
| |
| #include <android-base/unique_fd.h> |
| #include <binder/IBinder.h> |
| #include <binder/RpcAddress.h> |
| #include <utils/Errors.h> |
| #include <utils/RefBase.h> |
| |
| #include <optional> |
| #include <vector> |
| |
| // WARNING: This is a feature which is still in development, and it is subject |
| // to radical change. Any production use of this may subject your code to any |
| // number of problems. |
| |
| namespace android { |
| |
| class Parcel; |
| class RpcServer; |
| class RpcState; |
| |
| /** |
| * This represents a multi-threaded/multi-socket connection between a client |
| * and a server. |
| */ |
| class RpcConnection final : public virtual RefBase { |
| public: |
| static sp<RpcConnection> make(); |
| |
| /** |
| * This represents a connection for responses, e.g.: |
| * |
| * process A serves binder a |
| * process B opens a connection to process A |
| * process B makes binder b and sends it to A |
| * A uses this 'back connection' to send things back to B |
| * |
| * This should be called once, and then a call should be made to join per |
| * connection thread. |
| */ |
| [[nodiscard]] bool setupUnixDomainServer(const char* path); |
| |
| /** |
| * This should be called once per thread, matching 'join' in the remote |
| * process. |
| */ |
| [[nodiscard]] bool addUnixDomainClient(const char* path); |
| |
| #ifdef __BIONIC__ |
| /** |
| * Creates an RPC server at the current port. |
| */ |
| [[nodiscard]] bool setupVsockServer(unsigned int port); |
| |
| /** |
| * Connects to an RPC server at the CVD & port. |
| */ |
| [[nodiscard]] bool addVsockClient(unsigned int cvd, unsigned int port); |
| #endif // __BIONIC__ |
| |
| /** |
| * Creates an RPC server at the current port using IPv4. |
| * |
| * TODO(b/182914638): IPv6 support |
| * |
| * Set |port| to 0 to pick an ephemeral port; see discussion of |
| * /proc/sys/net/ipv4/ip_local_port_range in ip(7). In this case, |assignedPort| |
| * will be set to the picked port number, if it is not null. |
| */ |
| [[nodiscard]] bool setupInetServer(unsigned int port, unsigned int* assignedPort); |
| |
| /** |
| * Connects to an RPC server at the given address and port. |
| */ |
| [[nodiscard]] bool addInetClient(const char* addr, unsigned int port); |
| |
| /** |
| * For debugging! |
| * |
| * Sets up an empty socket. All queries to this socket which require a |
| * response will never be satisfied. All data sent here will be |
| * unceremoniously cast down the bottomless pit, /dev/null. |
| */ |
| [[nodiscard]] bool addNullDebuggingClient(); |
| |
| /** |
| * Query the other side of the connection for the root object hosted by that |
| * process's RpcServer (if one exists) |
| */ |
| sp<IBinder> getRootObject(); |
| |
| [[nodiscard]] status_t transact(const RpcAddress& address, uint32_t code, const Parcel& data, |
| Parcel* reply, uint32_t flags); |
| [[nodiscard]] status_t sendDecStrong(const RpcAddress& address); |
| |
| /** |
| * Adds a server thread accepting connections. Must be called after |
| * setup*Server. |
| */ |
| void join(); |
| |
| ~RpcConnection(); |
| |
| void setForServer(const wp<RpcServer>& server); |
| wp<RpcServer> server(); |
| |
| // internal only |
| const std::unique_ptr<RpcState>& state() { return mState; } |
| |
| class SocketAddress { |
| public: |
| virtual ~SocketAddress(); |
| virtual std::string toString() const = 0; |
| virtual const sockaddr* addr() const = 0; |
| virtual size_t addrSize() const = 0; |
| }; |
| |
| private: |
| friend sp<RpcConnection>; |
| RpcConnection(); |
| |
| struct ConnectionSocket : public RefBase { |
| base::unique_fd fd; |
| |
| // whether this or another thread is currently using this fd to make |
| // or receive transactions. |
| std::optional<pid_t> exclusiveTid; |
| }; |
| |
| bool setupSocketServer(const SocketAddress& address); |
| bool addSocketClient(const SocketAddress& address); |
| void addClient(base::unique_fd&& fd); |
| sp<ConnectionSocket> assignServerToThisThread(base::unique_fd&& fd); |
| bool removeServerSocket(const sp<ConnectionSocket>& socket); |
| |
| enum class SocketUse { |
| CLIENT, |
| CLIENT_ASYNC, |
| CLIENT_REFCOUNT, |
| }; |
| |
| // RAII object for connection socket |
| class ExclusiveSocket { |
| public: |
| explicit ExclusiveSocket(const sp<RpcConnection>& connection, SocketUse use); |
| ~ExclusiveSocket(); |
| const base::unique_fd& fd() { return mSocket->fd; } |
| |
| private: |
| static void findSocket(pid_t tid, sp<ConnectionSocket>* exclusive, |
| sp<ConnectionSocket>* available, |
| std::vector<sp<ConnectionSocket>>& sockets, size_t socketsIndexHint); |
| |
| sp<RpcConnection> mConnection; // avoid deallocation |
| sp<ConnectionSocket> mSocket; |
| |
| // whether this is being used for a nested transaction (being on the same |
| // thread guarantees we won't write in the middle of a message, the way |
| // the wire protocol is constructed guarantees this is safe). |
| bool mReentrant = false; |
| }; |
| |
| // On the other side of a connection, for each of mClients here, there should |
| // be one of mServers on the other side (and vice versa). |
| // |
| // For the simplest connection, a single server with one client, you would |
| // have: |
| // - the server has a single 'mServers' and a thread listening on this |
| // - the client has a single 'mClients' and makes calls to this |
| // - here, when the client makes a call, the server can call back into it |
| // (nested calls), but outside of this, the client will only ever read |
| // calls from the server when it makes a call itself. |
| // |
| // For a more complicated case, the client might itself open up a thread to |
| // serve calls to the server at all times (e.g. if it hosts a callback) |
| |
| wp<RpcServer> mForServer; // maybe null, for client connections |
| |
| std::unique_ptr<RpcState> mState; |
| |
| base::unique_fd mServer; // socket we are accepting connections on |
| |
| std::mutex mSocketMutex; // for all below |
| std::condition_variable mSocketCv; // for mWaitingThreads |
| size_t mWaitingThreads = 0; |
| size_t mClientsOffset = 0; // hint index into clients, ++ when sending an async transaction |
| std::vector<sp<ConnectionSocket>> mClients; |
| std::vector<sp<ConnectionSocket>> mServers; |
| }; |
| |
| } // namespace android |