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Diffstat (limited to 'src/util/sock.h')
| -rw-r--r-- | src/util/sock.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/src/util/sock.h b/src/util/sock.h new file mode 100644 index 0000000000..59cc8c0b1d --- /dev/null +++ b/src/util/sock.h @@ -0,0 +1,185 @@ +// Copyright (c) 2020-2021 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_UTIL_SOCK_H +#define BITCOIN_UTIL_SOCK_H + +#include <compat.h> +#include <threadinterrupt.h> +#include <util/time.h> + +#include <chrono> +#include <string> + +/** + * Maximum time to wait for I/O readiness. + * It will take up until this time to break off in case of an interruption. + */ +static constexpr auto MAX_WAIT_FOR_IO = 1s; + +/** + * RAII helper class that manages a socket. Mimics `std::unique_ptr`, but instead of a pointer it + * contains a socket and closes it automatically when it goes out of scope. + */ +class Sock +{ +public: + /** + * Default constructor, creates an empty object that does nothing when destroyed. + */ + Sock(); + + /** + * Take ownership of an existent socket. + */ + explicit Sock(SOCKET s); + + /** + * Copy constructor, disabled because closing the same socket twice is undesirable. + */ + Sock(const Sock&) = delete; + + /** + * Move constructor, grab the socket from another object and close ours (if set). + */ + Sock(Sock&& other); + + /** + * Destructor, close the socket or do nothing if empty. + */ + virtual ~Sock(); + + /** + * Copy assignment operator, disabled because closing the same socket twice is undesirable. + */ + Sock& operator=(const Sock&) = delete; + + /** + * Move assignment operator, grab the socket from another object and close ours (if set). + */ + virtual Sock& operator=(Sock&& other); + + /** + * Get the value of the contained socket. + * @return socket or INVALID_SOCKET if empty + */ + [[nodiscard]] virtual SOCKET Get() const; + + /** + * Get the value of the contained socket and drop ownership. It will not be closed by the + * destructor after this call. + * @return socket or INVALID_SOCKET if empty + */ + virtual SOCKET Release(); + + /** + * Close if non-empty. + */ + virtual void Reset(); + + /** + * send(2) wrapper. Equivalent to `send(this->Get(), data, len, flags);`. Code that uses this + * wrapper can be unit tested if this method is overridden by a mock Sock implementation. + */ + [[nodiscard]] virtual ssize_t Send(const void* data, size_t len, int flags) const; + + /** + * recv(2) wrapper. Equivalent to `recv(this->Get(), buf, len, flags);`. Code that uses this + * wrapper can be unit tested if this method is overridden by a mock Sock implementation. + */ + [[nodiscard]] virtual ssize_t Recv(void* buf, size_t len, int flags) const; + + /** + * connect(2) wrapper. Equivalent to `connect(this->Get(), addr, addrlen)`. Code that uses this + * wrapper can be unit tested if this method is overridden by a mock Sock implementation. + */ + [[nodiscard]] virtual int Connect(const sockaddr* addr, socklen_t addr_len) const; + + /** + * getsockopt(2) wrapper. Equivalent to + * `getsockopt(this->Get(), level, opt_name, opt_val, opt_len)`. Code that uses this + * wrapper can be unit tested if this method is overridden by a mock Sock implementation. + */ + [[nodiscard]] virtual int GetSockOpt(int level, + int opt_name, + void* opt_val, + socklen_t* opt_len) const; + + using Event = uint8_t; + + /** + * If passed to `Wait()`, then it will wait for readiness to read from the socket. + */ + static constexpr Event RECV = 0b01; + + /** + * If passed to `Wait()`, then it will wait for readiness to send to the socket. + */ + static constexpr Event SEND = 0b10; + + /** + * Wait for readiness for input (recv) or output (send). + * @param[in] timeout Wait this much for at least one of the requested events to occur. + * @param[in] requested Wait for those events, bitwise-or of `RECV` and `SEND`. + * @param[out] occurred If not nullptr and `true` is returned, then upon return this + * indicates which of the requested events occurred. A timeout is indicated by return + * value of `true` and `occurred` being set to 0. + * @return true on success and false otherwise + */ + [[nodiscard]] virtual bool Wait(std::chrono::milliseconds timeout, + Event requested, + Event* occurred = nullptr) const; + + /* Higher level, convenience, methods. These may throw. */ + + /** + * Send the given data, retrying on transient errors. + * @param[in] data Data to send. + * @param[in] timeout Timeout for the entire operation. + * @param[in] interrupt If this is signaled then the operation is canceled. + * @throws std::runtime_error if the operation cannot be completed. In this case only some of + * the data will be written to the socket. + */ + virtual void SendComplete(const std::string& data, + std::chrono::milliseconds timeout, + CThreadInterrupt& interrupt) const; + + /** + * Read from socket until a terminator character is encountered. Will never consume bytes past + * the terminator from the socket. + * @param[in] terminator Character up to which to read from the socket. + * @param[in] timeout Timeout for the entire operation. + * @param[in] interrupt If this is signaled then the operation is canceled. + * @param[in] max_data The maximum amount of data (in bytes) to receive. If this many bytes + * are received and there is still no terminator, then this method will throw an exception. + * @return The data that has been read, without the terminating character. + * @throws std::runtime_error if the operation cannot be completed. In this case some bytes may + * have been consumed from the socket. + */ + [[nodiscard]] virtual std::string RecvUntilTerminator(uint8_t terminator, + std::chrono::milliseconds timeout, + CThreadInterrupt& interrupt, + size_t max_data) const; + + /** + * Check if still connected. + * @param[out] errmsg The error string, if the socket has been disconnected. + * @return true if connected + */ + [[nodiscard]] virtual bool IsConnected(std::string& errmsg) const; + +protected: + /** + * Contained socket. `INVALID_SOCKET` designates the object is empty. + */ + SOCKET m_socket; +}; + +/** Return readable error string for a network error code */ +std::string NetworkErrorString(int err); + +/** Close socket and set hSocket to INVALID_SOCKET */ +bool CloseSocket(SOCKET& hSocket); + +#endif // BITCOIN_UTIL_SOCK_H |