Files
EMS-ESP32/lib/uuid-telnet/src/uuid/telnet.h
2020-05-08 16:04:53 +02:00

442 lines
15 KiB
C++

/*
* uuid-telnet - Telnet service
* Copyright 2019 Simon Arlott
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef UUID_TELNET_H_
#define UUID_TELNET_H_
#include <Arduino.h>
#ifdef ARDUINO_ARCH_ESP8266
# include <ESP8266WiFi.h>
#else
# include <WiFi.h>
#endif
#include <WiFiUdp.h>
#include <functional>
#include <list>
#include <memory>
#include <string>
#include <vector>
#include <uuid/console.h>
namespace uuid {
/**
* Telnet service.
*
* - <a href="https://github.com/nomis/mcu-uuid-telnet/">Git Repository</a>
* - <a href="https://mcu-uuid-telnet.readthedocs.io/">Documentation</a>
*/
namespace telnet {
/**
* Stream wrapper that performs telnet protocol handling, option
* negotiation and output buffering.
*
* @since 0.1.0
*/
class TelnetStream: public ::Stream {
public:
/**
* Create a new telnet stream wrapper.
*
* @param[in] client Client connection.
* @since 0.1.0
*/
explicit TelnetStream(WiFiClient &client);
virtual ~TelnetStream() = default;
/**
* Perform initial negotiation.
*
* @since 0.1.0
*/
void start();
/**
* Check for available input.
*
* @return The number of bytes available to read.
* @since 0.1.0
*/
int available() override;
/**
* Read one byte from the available input.
*
* @return An unsigned char if input is available, otherwise -1.
* @since 0.1.0
*/
int read() override;
/**
* Read one byte from the available input without advancing to the
* next one.
*
* @return An unsigned char if input is available, otherwise -1.
* @since 0.1.0
*/
int peek() override;
/**
* Write one byte to the output stream.
*
* Disconnect the client if the socket buffer is full.
*
* @param[in] data Data to be output.
* @return The number of bytes that were output.
* @since 0.1.0
*/
size_t write(uint8_t data) override;
/**
* Write an array of bytes to the output stream.
*
* Disconnect the client if the socket buffer is full.
*
* @param[in] buffer Buffer to be output.
* @param[in] size Length of the buffer.
* @return The number of bytes that were output.
* @since 0.1.0
*/
size_t write(const uint8_t *buffer, size_t size) override;
/**
* Does nothing.
*
* This is a pure virtual function in Arduino's Stream class, which
* makes no sense because that class is for input and this is an
* output function. Later versions move it to Print as an empty
* virtual function so this is here for backward compatibility.
*
* @since 0.1.0
*/
void flush() override;
private:
static constexpr const unsigned char NUL = 0; /*!< No operation. @since 0.1.0 */
static constexpr const unsigned char BEL = 7; /*!< Produces an audible or visible signal. @since 0.1.0 */
static constexpr const unsigned char BS = 8; /*!< Moves the print head one character position towards the left margin. @since 0.1.0 */
static constexpr const unsigned char HT = 9; /*!< Moves the printer to the next horizontal tab stop. @since 0.1.0 */
static constexpr const unsigned char LF = 10; /*!< Line Feed. @since 0.1.0 */
static constexpr const unsigned char VT = 11; /*!< Moves the printer to the next vertical tab stop. @since 0.1.0 */
static constexpr const unsigned char FF = 12; /*!< Moves the printer to the top of the next page, keeping the same horizontal position. @since 0.1.0 */
static constexpr const unsigned char CR = 13; /*!< Carriage Return. @since 0.1.0 */
static constexpr const unsigned char SE = 240; /*!< End of sub-negotiation parameters. @since 0.1.0 */
static constexpr const unsigned char NOP = 241; /*!< No operation. @since 0.1.0 */
static constexpr const unsigned char DM = 242; /*!< The data stream portion of a Synch. @since 0.1.0 */
static constexpr const unsigned char BRK = 243; /*!< NVT character BRK. @since 0.1.0 */
static constexpr const unsigned char IP = 244; /*!< Interrupt Process function. @since 0.1.0 */
static constexpr const unsigned char AO = 245; /*!< Abort Output function. @since 0.1.0 */
static constexpr const unsigned char AYT = 246; /*!< Are You There function. @since 0.1.0 */
static constexpr const unsigned char EC = 247; /*!< Erase Character function. @since 0.1.0 */
static constexpr const unsigned char EL = 248; /*!< Erase Line function. @since 0.1.0 */
static constexpr const unsigned char GA = 249; /*!< Go Ahead signal. @since 0.1.0 */
static constexpr const unsigned char SB = 250; /*!< Sub-negotiation of the indicated option. @since 0.1.0 */
static constexpr const unsigned char WILL = 251; /*!< Indicates the desire to begin performing, or confirmation that you are now performing, the indicated option. @since 0.1.0 */
static constexpr const unsigned char WONT = 252; /*!< Indicates the refusal to perform, or continue performing, the indicated option. @since 0.1.0 */
static constexpr const unsigned char DO = 253; /*!< Indicates the request that the other party perform, or confirmation that you are expecting the other party to perform, the indicated option. @since 0.1.0 */
static constexpr const unsigned char DONT = 254; /*!< Indicates the demand that the other party stop performing, or confirmation that you are no longer expecting the other party to perform, the indicated option. @since 0.1.0 */
static constexpr const unsigned char IAC = 255; /*!< Interpret As Command escape character. @since 0.1.0 */
static constexpr const unsigned char OPT_BINARY = 0; /*!< Binary (8-bit) transmission mode. (RFC 856). @since 0.1.0 */
static constexpr const unsigned char OPT_ECHO = 1; /*!< Remote Echo (RFC 857). @since 0.1.0 */
static constexpr const unsigned char OPT_SGA = 3; /*!< Suppress Go Ahead (RFC 858). @since 0.1.0 */
static constexpr const size_t BUFFER_SIZE = 536; /*!< Output buffer size. @since 0.1.0 */
TelnetStream(const TelnetStream&) = delete;
TelnetStream& operator=(const TelnetStream&) = delete;
/**
* Directly check for available input.
*
* @return The number of bytes available to read.
* @since 0.1.0
*/
int raw_available();
/**
* Read one byte directly from the available input.
*
* @return An unsigned char if input is available, otherwise -1.
* @since 0.1.0
*/
int raw_read();
/**
* Flush output stream buffer.
*
* Disconnect the client if the socket buffer is full.
*
* @since 0.1.0
*/
void buffer_flush();
/**
* Write one byte directly to the output stream.
*
* Disconnect the client if the socket buffer is full.
*
* @param[in] data Data to be output.
* @return The number of bytes that were output.
* @since 0.1.0
*/
size_t raw_write(unsigned char data);
/**
* Write a vector of bytes directly to the output stream.
*
* Disconnect the client if the socket buffer is full.
*
* @param[in] data Data to be output.
* @return The number of bytes that were output.
* @since 0.1.0
*/
size_t raw_write(const std::vector<unsigned char> &data);
/**
* Write an array of bytes directly to the output stream.
*
* Disconnect the client if the socket buffer is full.
*
* @param[in] buffer Buffer to be output.
* @param[in] size Length of the buffer.
* @return The number of bytes that were output.
* @since 0.1.0
*/
size_t raw_write(const uint8_t *buffer, size_t size);
WiFiClient &client_; /*!< Client connection. @since 0.1.0 */
unsigned char previous_raw_in_ = 0; /*!< Previous raw character that was received. Used to detect commands. @since 0.1.0 */
bool sub_negotiation_ = false; /*!< Sub-negotiation mode. @since 0.1.0 */
unsigned char previous_in_ = 0; /*!< Previous character that was received. Used to detect CR NUL. @since 0.1.0 */
unsigned char previous_out_ = 0; /*!< Previous character that was sent. Used to insert NUL after CR without LF. @since 0.1.0 */
int peek_ = -1; /*!< Previously read data cached by peek(). @since 0.1.0 */
std::vector<char> output_buffer_; /*!< Buffer data to be output until a read function is called. @since 0.1.0 */
};
/**
* Provides access to a console shell as a telnet server.
*
* @since 0.1.0
*/
class TelnetService {
public:
static constexpr size_t MAX_CONNECTIONS = 3; /*!< Maximum number of concurrent open connections. @since 0.1.0 */
static constexpr uint16_t DEFAULT_PORT = 23; /*!< Default TCP port to listen on. @since 0.1.0 */
static constexpr unsigned long DEFAULT_IDLE_TIMEOUT = 600; /*!< Default initial idle timeout (in seconds). @since 0.1.0 */
static constexpr unsigned long DEFAULT_WRITE_TIMEOUT = 0; /*!< Default write timeout (in milliseconds). @ since 0.1.0 */
/**
* Function to handle the creation of a shell.
*
* @param[in] stream Stream for the telnet connection.
* @param[in] addr Remote IP address.
* @param[in] port Remote port.
* @since 0.1.0
*/
using shell_factory_function = std::function<std::shared_ptr<uuid::console::Shell>(Stream &stream, const IPAddress &addr, uint16_t port)>;
/**
* Create a new telnet service listening on the default port.
*
* @param[in] commands Commands available for execution in shells.
* @param[in] context Default context for shells.
* @param[in] flags Initial flags for shells.
* @since 0.1.0
*/
TelnetService(std::shared_ptr<uuid::console::Commands> commands, unsigned int context = 0, unsigned int flags = 0);
/**
* Create a new telnet service listening on a specific port.
*
* @param[in] port TCP listening port.
* @param[in] commands Commands available for execution in shells.
* @param[in] context Default context for shells.
* @param[in] flags Initial flags for shells.
* @since 0.1.0
*/
TelnetService(uint16_t port, std::shared_ptr<uuid::console::Commands> commands, unsigned int context = 0, unsigned int flags = 0);
/**
* Create a new telnet service listening on the default port.
*
* @param[in] shell_factory Function to create a shell for new connections.
* @since 0.1.0
*/
explicit TelnetService(shell_factory_function shell_factory);
/**
* Create a new telnet service listening on a specific port.
*
* @param[in] port TCP listening port.
* @param[in] shell_factory Function to create a shell for new connections.
* @since 0.1.0
*/
TelnetService(uint16_t port, shell_factory_function shell_factory);
~TelnetService() = default;
/**
* Start listening for connections on the configured port.
*
* @since 0.1.0
*/
void start();
/**
* Close all connections.
*
* The listening status is not affected.
*
* @since 0.1.0
*/
void close_all();
/**
* Stop listening for connections.
*
* Existing connections are not affected.
*
* @since 0.1.0
*/
void stop();
/**
* Get the maximum number of concurrent open connections.
*
* @return The maximum number of concurrent open connections.
* @since 0.1.0
*/
size_t maximum_connections() const;
/**
* Set the maximum number of concurrent open connections.
*
* Defaults to TelnetService::MAX_CONNECTIONS.
*
* @since 0.1.0
*/
void maximum_connections(size_t count);
/**
* Get the initial idle timeout for new connections.
*
* @return The initial idle timeout in seconds (or 0 for disabled).
* @since 0.1.0
*/
unsigned long initial_idle_timeout() const;
/**
* Set the initial idle timeout for new connections.
*
* Defaults to TelnetService::DEFAULT_IDLE_TIMEOUT.
*
* @param[in] timeout Idle timeout in seconds (or 0 to disable).
* @since 0.1.0
*/
void initial_idle_timeout(unsigned long timeout);
/**
* Get the default socket write timeout for new connections.
*
* @return The default socket write timeout in seconds (or 0 for
* platform default).
* @since 0.1.0
*/
unsigned long default_write_timeout() const;
/**
* Set the default socket write timeout for new connections.
*
* Defaults to TelnetService::DEFAULT_WRITE_TIMEOUT (platform
* default).
*
* @param[in] timeout Socket write timeout in seconds (or 0 for
* platform default).
* @since 0.1.0
*/
void default_write_timeout(unsigned long timeout);
/**
* Accept new connections.
*
* @since 0.1.0
*/
void loop();
private:
/**
* Telnet connection.
*
* Holds the client and stream instance for the lifetime of the shell.
*
* @since 0.1.0
*/
class Connection {
public:
/**
* Create a telnet connection shell.
*
* @param[in] shell_factory Function to create a shell for new connections.
* @param[in] client Client connection.
* @param[in] idle_timeout Idle timeout in seconds.
* @param[in] write_timeout Idle timeout in milliseconds.
* @since 0.1.0
*/
Connection(shell_factory_function &shell_factory, WiFiClient &&client, unsigned long idle_timeout, unsigned long write_timeout);
~Connection() = default;
/**
* Check if the shell is still active.
*
* @return Active status of the shell.
* @since 0.1.0
*/
bool active();
/**
* Stop the shell if the client is not connected.
*
* @return Active status of the shell.
* @since 0.1.0
*/
bool loop();
/**
* Stop the shell.
*
* @since 0.1.0
*/
void stop();
private:
Connection(const Connection&) = delete;
Connection& operator=(const Connection&) = delete;
WiFiClient client_; /*!< Client connection. @since 0.1.0 */
TelnetStream stream_; /*!< Telnet stream for the connection. @since 0.1.0 */
std::shared_ptr<uuid::console::Shell> shell_; /*!< Shell for connection. @since 0.1.0 */
IPAddress addr_; /*!< Remote address of connection. @since 0.1.0 */
uint16_t port_; /*!< Remote port of connection. @since 0.1.0 */
};
TelnetService(const TelnetService&) = delete;
TelnetService& operator=(const TelnetService&) = delete;
static uuid::log::Logger logger_; /*!< uuid::log::Logger instance for telnet services. @since 0.1.0 */
WiFiServer server_; /*!< TCP server. @since 0.1.0 */
size_t maximum_connections_ = MAX_CONNECTIONS; /*!< Maximum number of concurrent open connections. @since 0.1.0 */
std::list<Connection> connections_; /*!< Open connections. @since 0.1.0 */
shell_factory_function shell_factory_; /*!< Function to create a shell. @since 0.1.0 */
unsigned long initial_idle_timeout_ = DEFAULT_IDLE_TIMEOUT; /*!< Initial idle timeout (in seconds). @since 0.1.0 */
unsigned long write_timeout_ = DEFAULT_WRITE_TIMEOUT; /*!< Write timeout (in milliseconds). @since 0.1.0 */
};
} // namespace telnet
} // namespace uuid
#endif