/* Copyright (c) 2015, 2024, 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 designed to work 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 either included with the program or referenced in the documentation. 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 Server session service implementation. For more information please check the function comments. */ #include #include #include "my_dbug.h" /* service_srv_session.h should not be first to be included as it will include - include/mysql/service_srv_session.h - include/mysql/plugin.h - include/mysql/services.h - include/mysql/service_command.h which in turn will need MYSQL_SESSION but won't see it, as it will be declared after the includes. */ #include "mysql/service_srv_session.h" #include "mysqld_error.h" #include "sql/conn_handler/connection_handler_manager.h" #include "sql/current_thd.h" // current_thd #include "sql/derror.h" // ER_DEFAULT #include "sql/mysqld.h" // SERVER_OPERATING #include "sql/server_component/mysql_admin_session_imp.h" /* mysql_component_mysql_admin_session_imp */ #include "sql/sql_class.h" #include "sql/srv_session.h" /** Initializes physical thread to use with session service. @return 0 success 1 failure */ int srv_session_init_thread(const void *plugin) { return Srv_session::init_thread(plugin); } /** Deinitializes physical thread to use with session service */ void srv_session_deinit_thread() { Srv_session::deinit_thread(); } /** Opens server session @param error_cb Default completion callback @param plugin_ctx Plugin's context, opaque pointer that would be provided to callbacks. Might be NULL. @param ignore_max_connection_limit true if the session is exempted @return handler of session on success NULL on failure */ Srv_session *srv_session_open_internal(srv_session_error_cb error_cb, void *plugin_ctx, bool ignore_max_connection_limit) { DBUG_TRACE; if (!srv_session_server_is_available()) { if (error_cb) error_cb(plugin_ctx, ER_SERVER_ISNT_AVAILABLE, ER_DEFAULT(ER_SERVER_ISNT_AVAILABLE)); return nullptr; } bool simulate_reach_max_connections = false; DBUG_EXECUTE_IF("simulate_reach_max_connections", simulate_reach_max_connections = true;); Connection_handler_manager *conn_manager = Connection_handler_manager::get_instance(); if (simulate_reach_max_connections || !conn_manager->check_and_incr_conn_count(ignore_max_connection_limit)) { if (error_cb) error_cb(plugin_ctx, ER_CON_COUNT_ERROR, ER_DEFAULT(ER_CON_COUNT_ERROR)); return nullptr; } Srv_session *session = nullptr; try { session = new Srv_session(error_cb, plugin_ctx); } catch (...) { DBUG_PRINT("error", ("Can't allocate a Srv_session object")); connection_errors_internal++; if (error_cb) error_cb(plugin_ctx, ER_OUT_OF_RESOURCES, ER_DEFAULT(ER_OUT_OF_RESOURCES)); return nullptr; } THD *current = current_thd; THD *stack_thd = session->get_thd(); session->get_thd()->thread_stack = reinterpret_cast(&stack_thd); session->get_thd()->store_globals(); const bool result = session->open(); session->get_thd()->restore_globals(); if (result) { delete session; session = nullptr; } if (current) current->store_globals(); return session; } /** Opens server session @return handler of session on success NULL on failure */ Srv_session *srv_session_open(srv_session_error_cb error_cb, void *plugin_ctx) { DBUG_TRACE; return srv_session_open_internal(error_cb, plugin_ctx, false); } /** Opens server admin session @param error_cb Default completion callback @param ctx Plugin's context, opaque pointer that would be provided to callbacks. Might be NULL. @sa srv_session_open_internal @return handler of session on success NULL on failure */ DEFINE_METHOD(MYSQL_SESSION, mysql_component_mysql_admin_session_imp::open, (srv_session_error_cb error_cb, void *ctx)) { DBUG_TRACE; return srv_session_open_internal(error_cb, ctx, true); } /** Detaches a session from current physical thread. @param session Session handle to detach @returns 0 success 1 failure */ int srv_session_detach(Srv_session *session) { DBUG_TRACE; if (!session || !Srv_session::is_valid(session)) { DBUG_PRINT("error", ("Session is not valid")); return true; } return session->detach(); } /** Closes a session. @param session Session handle to close @returns 0 Session successfully closed 1 Session wasn't found or key doesn't match */ int srv_session_close(Srv_session *session) { DBUG_TRACE; if (!session || !Srv_session::is_valid(session)) { DBUG_PRINT("error", ("Session is not valid")); return 1; } session->close(); delete session; /* Here we don't need to reattach the previous session, as the next function (run_command() for example) will attach to whatever is needed. */ return 0; } /** Returns if the server is available (not booting or shutting down) @return 0 not available 1 available */ int srv_session_server_is_available() { return get_server_state() == SERVER_OPERATING; } /** Attaches a session to current srv_session physical thread. @returns 0 success 1 failure */ int srv_session_attach(MYSQL_SESSION session, MYSQL_THD *ret_previous_thd) { DBUG_TRACE; if (!Srv_session::is_srv_session_thread()) { DBUG_PRINT("error", ("Thread can't be used with srv_session API")); return 1; } if (!session || !Srv_session::is_valid(session)) { DBUG_PRINT("error", ("Session is not valid")); return 1; } if (ret_previous_thd) *ret_previous_thd = current_thd; return session->attach(); }