| /* |
| * Copyright (C) 2021 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. |
| */ |
| |
| // Wraps the transport layer of RPC. Implementation may use plain sockets or TLS. |
| |
| #pragma once |
| |
| #include <functional> |
| #include <memory> |
| #include <optional> |
| #include <string> |
| #include <variant> |
| #include <vector> |
| |
| #include <android-base/function_ref.h> |
| #include <android-base/unique_fd.h> |
| #include <utils/Errors.h> |
| |
| #include <binder/RpcCertificateFormat.h> |
| #include <binder/RpcThreads.h> |
| |
| #include <sys/uio.h> |
| |
| namespace android { |
| |
| class FdTrigger; |
| struct RpcTransportFd; |
| |
| // Represents a socket connection. |
| // No thread-safety is guaranteed for these APIs. |
| class RpcTransport { |
| public: |
| virtual ~RpcTransport() = default; |
| |
| /** |
| * Poll the transport to check whether there is any data ready to read. |
| * |
| * Return: |
| * OK - There is data available on this transport |
| * WOULDBLOCK - No data is available |
| * error - any other error |
| */ |
| [[nodiscard]] virtual status_t pollRead(void) = 0; |
| |
| /** |
| * Read (or write), but allow to be interrupted by a trigger. |
| * |
| * iovs - array of iovecs to perform the operation on. The elements |
| * of the array may be modified by this method. |
| * |
| * altPoll - function to be called instead of polling, when needing to wait |
| * to read/write data. If this returns an error, that error is returned from |
| * this function. |
| * |
| * ancillaryFds - FDs to be sent via UNIX domain dockets or Trusty IPC. When |
| * reading, if `ancillaryFds` is null, any received FDs will be silently |
| * dropped and closed (by the OS). Appended values will always be unique_fd, |
| * the variant type is used to avoid extra copies elsewhere. |
| * |
| * Return: |
| * OK - succeeded in completely processing 'size' |
| * error - interrupted (failure or trigger) |
| */ |
| [[nodiscard]] virtual status_t interruptableWriteFully( |
| FdTrigger *fdTrigger, iovec *iovs, int niovs, |
| const std::optional<android::base::function_ref<status_t()>> &altPoll, |
| const std::vector<std::variant<base::unique_fd, base::borrowed_fd>> *ancillaryFds) = 0; |
| [[nodiscard]] virtual status_t interruptableReadFully( |
| FdTrigger *fdTrigger, iovec *iovs, int niovs, |
| const std::optional<android::base::function_ref<status_t()>> &altPoll, |
| std::vector<std::variant<base::unique_fd, base::borrowed_fd>> *ancillaryFds) = 0; |
| |
| /** |
| * Check whether any threads are blocked while polling the transport |
| * for read operations |
| * Return: |
| * True - Specifies that there is active polling on transport. |
| * False - No active polling on transport |
| */ |
| [[nodiscard]] virtual bool isWaiting() = 0; |
| |
| protected: |
| RpcTransport() = default; |
| }; |
| |
| // Represents the context that generates the socket connection. |
| // All APIs are thread-safe. See RpcTransportCtxRaw and RpcTransportCtxTls for details. |
| class RpcTransportCtx { |
| public: |
| virtual ~RpcTransportCtx() = default; |
| |
| // Create a new RpcTransport object. |
| // |
| // Implementation details: for TLS, this function may incur I/O. |fdTrigger| may be used |
| // to interrupt I/O. This function blocks until handshake is finished. |
| [[nodiscard]] virtual std::unique_ptr<RpcTransport> newTransport( |
| android::RpcTransportFd fd, FdTrigger *fdTrigger) const = 0; |
| |
| // Return the preconfigured certificate of this context. |
| // |
| // Implementation details: |
| // - For raw sockets, this always returns empty string. |
| // - For TLS, this returns the certificate. See RpcTransportTls for details. |
| [[nodiscard]] virtual std::vector<uint8_t> getCertificate( |
| RpcCertificateFormat format) const = 0; |
| |
| protected: |
| RpcTransportCtx() = default; |
| }; |
| |
| // A factory class that generates RpcTransportCtx. |
| // All APIs are thread-safe. |
| class RpcTransportCtxFactory { |
| public: |
| virtual ~RpcTransportCtxFactory() = default; |
| // Creates server context. |
| [[nodiscard]] virtual std::unique_ptr<RpcTransportCtx> newServerCtx() const = 0; |
| |
| // Creates client context. |
| [[nodiscard]] virtual std::unique_ptr<RpcTransportCtx> newClientCtx() const = 0; |
| |
| // Return a short description of this transport (e.g. "raw"). For logging / debugging / testing |
| // only. |
| [[nodiscard]] virtual const char *toCString() const = 0; |
| |
| protected: |
| RpcTransportCtxFactory() = default; |
| }; |
| |
| struct RpcTransportFd { |
| private: |
| mutable bool isPolling{false}; |
| |
| void setPollingState(bool state) const { isPolling = state; } |
| |
| public: |
| base::unique_fd fd; |
| |
| RpcTransportFd() = default; |
| explicit RpcTransportFd(base::unique_fd &&descriptor) |
| : isPolling(false), fd(std::move(descriptor)) {} |
| |
| RpcTransportFd(RpcTransportFd &&transportFd) noexcept |
| : isPolling(transportFd.isPolling), fd(std::move(transportFd.fd)) {} |
| |
| RpcTransportFd &operator=(RpcTransportFd &&transportFd) noexcept { |
| fd = std::move(transportFd.fd); |
| isPolling = transportFd.isPolling; |
| return *this; |
| } |
| |
| RpcTransportFd &operator=(base::unique_fd &&descriptor) noexcept { |
| fd = std::move(descriptor); |
| isPolling = false; |
| return *this; |
| } |
| |
| bool isInPollingState() const { return isPolling; } |
| friend class FdTrigger; |
| }; |
| |
| } // namespace android |