client_plugin.h

Go to the documentation of this file.

#ifndef MYSQL_CLIENT_PLUGIN_INCLUDED
/* Copyright (c) 2010, 2023, Oracle and/or its affiliates.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.
 
   Without limiting anything contained in the foregoing, this file,
   which is part of C Driver for MySQL (Connector/C), is also subject to the
   Universal FOSS Exception, version 1.0, a copy of which can be found at
   http://oss.oracle.com/licenses/universal-foss-exception.
 
   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, version 2.0, for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
/**
  @file include/mysql/client_plugin.h
  MySQL Client Plugin API.
  This file defines the API for plugins that work on the client side
*/
#define MYSQL_CLIENT_PLUGIN_INCLUDED
 
#ifndef MYSQL_ABI_CHECK
#include <stdarg.h>
#include <stdlib.h>
#endif
 
/*
  On Windows, exports from DLL need to be declared.
  Also, plugin needs to be declared as extern "C" because MSVC
  unlike other compilers, uses C++ mangling for variables not only
  for functions.
*/
 
#if defined(_MSC_VER)
#if defined(MYSQL_DYNAMIC_CLIENT_PLUGIN)
#ifdef __cplusplus
#define MYSQL_CLIENT_PLUGIN_EXPORT extern "C" __declspec(dllexport)
#else
#define MYSQL_CLIENT_PLUGIN_EXPORT __declspec(dllexport)
#endif
#else /* MYSQL_DYNAMIC_CLIENT_PLUGIN */
#ifdef __cplusplus
#define MYSQL_CLIENT_PLUGIN_EXPORT extern "C"
#else
#define MYSQL_CLIENT_PLUGIN_EXPORT
#endif
#endif /*MYSQL_DYNAMIC_CLIENT_PLUGIN */
#else  /*_MSC_VER */
 
#if defined(MYSQL_DYNAMIC_CLIENT_PLUGIN)
#define MYSQL_CLIENT_PLUGIN_EXPORT MY_ATTRIBUTE((visibility("default")))
#else
#define MYSQL_CLIENT_PLUGIN_EXPORT
#endif
 
#endif
 
#ifdef __cplusplus
extern "C" {
#endif
 
/* known plugin types */
#define MYSQL_CLIENT_reserved1 0
#define MYSQL_CLIENT_reserved2 1
#define MYSQL_CLIENT_AUTHENTICATION_PLUGIN 2
#define MYSQL_CLIENT_TRACE_PLUGIN 3
#define MYSQL_CLIENT_TELEMETRY_PLUGIN 4
 
#define MYSQL_CLIENT_AUTHENTICATION_PLUGIN_INTERFACE_VERSION 0x0200
#define MYSQL_CLIENT_TRACE_PLUGIN_INTERFACE_VERSION 0x0200
#define MYSQL_CLIENT_TELEMETRY_PLUGIN_INTERFACE_VERSION 0x0200
 
#define MYSQL_CLIENT_MAX_PLUGINS 5
 
#define MYSQL_CLIENT_PLUGIN_AUTHOR_ORACLE "Oracle Corporation"
 
#define mysql_declare_client_plugin(X)                  \
  MYSQL_CLIENT_PLUGIN_EXPORT st_mysql_client_plugin_##X \
      _mysql_client_plugin_declaration_ = {             \
          MYSQL_CLIENT_##X##_PLUGIN,                    \
          MYSQL_CLIENT_##X##_PLUGIN_INTERFACE_VERSION,
#define mysql_end_client_plugin }
 
/* generic plugin header structure */
#define MYSQL_CLIENT_PLUGIN_HEADER                  \
  int type;                                         \
  unsigned int interface_version;                   \
  const char *name;                                 \
  const char *author;                               \
  const char *desc;                                 \
  unsigned int version[3];                          \
  const char *license;                              \
  void *mysql_api;                                  \
  int (*init)(char *, size_t, int, va_list);        \
  int (*deinit)(void);                              \
  int (*options)(const char *option, const void *); \
  int (*get_options)(const char *option, void *);
 
struct st_mysql_client_plugin {
  MYSQL_CLIENT_PLUGIN_HEADER
};
 
struct MYSQL;
 
/******** authentication plugin specific declarations *********/
#include "plugin_auth_common.h"
 
struct auth_plugin_t {
  MYSQL_CLIENT_PLUGIN_HEADER
  int (*authenticate_user)(MYSQL_PLUGIN_VIO *vio, struct MYSQL *mysql);
  enum net_async_status (*authenticate_user_nonblocking)(MYSQL_PLUGIN_VIO *vio,
                                                         struct MYSQL *mysql,
                                                         int *result);
};
 
// Needed for the mysql_declare_client_plugin() macro. Do not use elsewhere.
typedef struct auth_plugin_t st_mysql_client_plugin_AUTHENTICATION;
 
/******** using plugins ************/
 
/**
  loads a plugin and initializes it
 
  @param mysql  MYSQL structure.
  @param name   a name of the plugin to load
  @param type   type of plugin that should be loaded, -1 to disable type check
  @param argc   number of arguments to pass to the plugin initialization
                function
  @param ...    arguments for the plugin initialization function
 
  @retval
  a pointer to the loaded plugin, or NULL in case of a failure
*/
struct st_mysql_client_plugin *mysql_load_plugin(struct MYSQL *mysql,
                                                 const char *name, int type,
                                                 int argc, ...);
 
/**
  loads a plugin and initializes it, taking va_list as an argument
 
  This is the same as mysql_load_plugin, but take va_list instead of
  a list of arguments.
 
  @param mysql  MYSQL structure.
  @param name   a name of the plugin to load
  @param type   type of plugin that should be loaded, -1 to disable type check
  @param argc   number of arguments to pass to the plugin initialization
                function
  @param args   arguments for the plugin initialization function
 
  @retval
  a pointer to the loaded plugin, or NULL in case of a failure
*/
struct st_mysql_client_plugin *mysql_load_plugin_v(struct MYSQL *mysql,
                                                   const char *name, int type,
                                                   int argc, va_list args);
 
/**
  finds an already loaded plugin by name, or loads it, if necessary
 
  @param mysql  MYSQL structure.
  @param name   a name of the plugin to load
  @param type   type of plugin that should be loaded
 
  @retval
  a pointer to the plugin, or NULL in case of a failure
*/
struct st_mysql_client_plugin *mysql_client_find_plugin(struct MYSQL *mysql,
                                                        const char *name,
                                                        int type);
 
/**
  adds a plugin structure to the list of loaded plugins
 
  This is useful if an application has the necessary functionality
  (for example, a special load data handler) statically linked into
  the application binary. It can use this function to register the plugin
  directly, avoiding the need to factor it out into a shared object.
 
  @param mysql  MYSQL structure. It is only used for error reporting
  @param plugin an st_mysql_client_plugin structure to register
 
  @retval
  a pointer to the plugin, or NULL in case of a failure
*/
struct st_mysql_client_plugin *mysql_client_register_plugin(
    struct MYSQL *mysql, struct st_mysql_client_plugin *plugin);
 
/**
  set plugin options
 
  Can be used to set extra options and affect behavior for a plugin.
  This function may be called multiple times to set several options
 
  @param plugin an st_mysql_client_plugin structure
  @param option a string which specifies the option to set
  @param value  value for the option.
 
  @retval 0 on success, 1 in case of failure
**/
int mysql_plugin_options(struct st_mysql_client_plugin *plugin,
                         const char *option, const void *value);
 
/**
  get plugin options
 
  Can be used to get options from a plugin.
  This function may be called multiple times to get several options
 
  @param plugin an st_mysql_client_plugin structure
  @param option a string which specifies the option to get
  @param[out] value  value for the option.
 
  @retval 0 on success, 1 in case of failure
**/
int mysql_plugin_get_option(struct st_mysql_client_plugin *plugin,
                            const char *option, void *value);
 
#ifdef __cplusplus
}
#endif
 
#endif