mysql_com.h

/* Copyright (c) 2000, 2025, 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.

 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_com.h
 Common definition between mysql server & client.
*/

#ifndef_mysql_com_h
#define_mysql_com_h

#ifndefMYSQL_ABI_CHECK
#include<stdbool.h>
#include<stdint.h>
#endif

#include"my_command.h"
#include"my_compress.h"

/*
 We need a definition for my_socket. On the client, <mysql.h> already provides
 it, but on the server side, we need to get it from a header.
*/
#ifndefmy_socket_defined
#include"my_io.h"
#include"mysql/components/services/bits/my_io_bits.h"
#endif

#ifndefMYSQL_ABI_CHECK
#include<stdbool.h>
#endif

#defineSYSTEM_CHARSET_MBMAXLEN 3
#defineFILENAME_CHARSET_MBMAXLEN 5
#defineNAME_CHAR_LEN 64 /**< Field/table name length */
#definePARTITION_EXPR_CHAR_LEN \
 2048 /**< Maximum expression length in chars \
 */
#defineUSERNAME_CHAR_LENGTH 32
#defineUSERNAME_CHAR_LENGTH_STR "32"
#ifndefNAME_LEN
#defineNAME_LEN (NAME_CHAR_LEN * SYSTEM_CHARSET_MBMAXLEN)
#endif
#defineUSERNAME_LENGTH (USERNAME_CHAR_LENGTH * SYSTEM_CHARSET_MBMAXLEN)
#defineCONNECT_STRING_MAXLEN 1024

#defineMYSQL_AUTODETECT_CHARSET_NAME "auto"

#defineSERVER_VERSION_LENGTH 60
#defineSQLSTATE_LENGTH 5

/*
 In FIDO terminology, relying party is the server where required services are
 running. Relying party ID is unique name given to server.
*/
#defineRELYING_PARTY_ID_LENGTH 255

/* Length of random salt sent during fido registration */
#defineCHALLENGE_LENGTH 32

/* Maximum authentication factors server supports */
#defineMAX_AUTH_FACTORS 3
/**
 Maximum length of comments

 pre 5.6: 60 characters
*/
#defineTABLE_COMMENT_INLINE_MAXLEN 180
#defineTABLE_COMMENT_MAXLEN 2048
#defineCOLUMN_COMMENT_MAXLEN 1024
#defineINDEX_COMMENT_MAXLEN 1024
#defineTABLE_PARTITION_COMMENT_MAXLEN 1024
#defineTABLESPACE_COMMENT_MAXLEN 2048

/**
 Maximum length of protocol packet.
 @ref page_protocol_basic_ok_packet length limit also restricted to this value
 as any length greater than this value will have first byte of
 @ref page_protocol_basic_ok_packet to be 254 thus does not
 provide a means to identify if this is @ref page_protocol_basic_ok_packet or
 @ref page_protocol_basic_eof_packet.
*/
#defineMAX_PACKET_LENGTH (256L * 256L * 256L - 1)

#defineLOCAL_HOST "localhost"
#defineLOCAL_HOST_NAMEDPIPE "."

#if defined(_WIN32)
#defineMYSQL_NAMEDPIPE "MySQL"
#defineMYSQL_SERVICENAME "MySQL"
#endif/* _WIN32 */

/** The length of the header part for each generated column in the .frm file.*/
#defineFRM_GCOL_HEADER_SIZE 4
/**
 Maximum length of the expression statement defined for generated columns.
*/
#defineGENERATED_COLUMN_EXPRESSION_MAXLEN 65535 - FRM_GCOL_HEADER_SIZE
/**
 Length of random string sent by server on handshake; this is also length of
 obfuscated password, received from client
*/
#defineSCRAMBLE_LENGTH 20
#defineAUTH_PLUGIN_DATA_PART_1_LENGTH 8
/** length of password stored in the db: new passwords are preceded with '*'*/
#defineSCRAMBLED_PASSWORD_CHAR_LENGTH (SCRAMBLE_LENGTH * 2 + 1)

/**
 @defgroup group_cs_column_definition_flags Column Definition Flags
 @ingroup group_cs

 @brief Values for the flags bitmask used by ::Send_field:flags

 Currently need to fit into 32 bits.

 Each bit represents an optional feature of the protocol.

 Both the client and the server are sending these.

 The intersection of the two determines what optional parts of the
 protocol will be used.
*/

/**
 @addtogroup group_cs_column_definition_flags
 @{
*/

#defineNOT_NULL_FLAG 1 /**< Field can't be NULL */
#definePRI_KEY_FLAG 2 /**< Field is part of a primary key */
#defineUNIQUE_KEY_FLAG 4 /**< Field is part of a unique key */
#defineMULTIPLE_KEY_FLAG 8 /**< Field is part of a key */
#defineBLOB_FLAG 16 /**< Field is a blob */
#defineUNSIGNED_FLAG 32 /**< Field is unsigned */
#defineZEROFILL_FLAG 64 /**< Field is zerofill */
#defineBINARY_FLAG 128 /**< Field is binary */

/* The following are only sent to new clients */
#defineENUM_FLAG 256 /**< field is an enum */
#defineAUTO_INCREMENT_FLAG 512 /**< field is a autoincrement field */
#defineTIMESTAMP_FLAG 1024 /**< Field is a timestamp */
#defineSET_FLAG 2048 /**< field is a set */
#defineNO_DEFAULT_VALUE_FLAG 4096 /**< Field doesn't have default value */
#defineON_UPDATE_NOW_FLAG 8192 /**< Field is set to NOW on UPDATE */
#definePART_KEY_FLAG 16384 /**< Intern; Part of some key */
#defineNUM_FLAG 32768 /**< Field is num (for clients) */
#defineUNIQUE_FLAG 65536 /**< Intern: Used by sql_yacc */
#defineBINCMP_FLAG 131072 /**< Intern: Used by sql_yacc */
#defineGET_FIXED_FIELDS_FLAG \
 (1 << 18) /**< Used to get fields in item tree \
 */
#defineFIELD_IN_PART_FUNC_FLAG (1 << 19) /**< Field part of partition func */
/**
 Intern: Field in TABLE object for new version of altered table,
 which participates in a newly added index.
*/
#defineFIELD_IN_ADD_INDEX (1 << 20)
#defineFIELD_IS_RENAMED (1 << 21) /**< Intern: Field is being renamed */
#defineFIELD_FLAGS_STORAGE_MEDIA 22 /**< Field storage media, bit 22-23 */
#defineFIELD_FLAGS_STORAGE_MEDIA_MASK (3 << FIELD_FLAGS_STORAGE_MEDIA)
#defineFIELD_FLAGS_COLUMN_FORMAT 24 /**< Field column format, bit 24-25 */
#defineFIELD_FLAGS_COLUMN_FORMAT_MASK (3 << FIELD_FLAGS_COLUMN_FORMAT)
#defineFIELD_IS_DROPPED (1 << 26) /**< Intern: Field is being dropped */
#defineEXPLICIT_NULL_FLAG \
 (1 << 27) /**< Field is explicitly specified as \
 NULL by the user */
#defineGROUP_FLAG \
 (1 << 28) /**< Intern: Group field. Transient use in \
 create_tmp_table */

/** Field will not be loaded in secondary engine. */
#defineNOT_SECONDARY_FLAG (1 << 29)
/** Field is explicitly marked as invisible by the user. */
#defineFIELD_IS_INVISIBLE (1 << 30)

/** @}*/

/**
 @defgroup group_cs_com_refresh_flags COM_REFRESH Flags
 @ingroup group_cs

 @brief Values for the `sub_command` in ::COM_REFRESH

 Currently the protocol carries only 8 bits of these flags.

 The rest (8-end) are used only internally in the server.
*/

/**
 @addtogroup group_cs_com_refresh_flags
 @{
*/

#defineREFRESH_GRANT 1 /**< Refresh grant tables, FLUSH PRIVILEGES */
#defineREFRESH_LOG 2 /**< Start on new log file, FLUSH LOGS */
#defineREFRESH_TABLES 4 /**< close all tables, FLUSH TABLES */
#defineUNUSED_8 \
 8 /**< Previously REFRESH_HOSTS but not used anymore. Use TRUNCATE TABLE \
 performance_schema.host_cache instead */
#defineREFRESH_STATUS 16 /**< Flush status variables, FLUSH STATUS */
#defineUNUSED_32 32 /**< Removed. Used to be flush thread cache */
#defineREFRESH_REPLICA \
 64 /**< Reset source info and restart replica \
 thread, RESET REPLICA */

#defineREFRESH_SOURCE \
 128 /**< Remove all bin logs in the index \
 and truncate the index. Also resets \
 GTID information. Command: \
 RESET BINARY LOGS AND GTIDS */

#defineREFRESH_ERROR_LOG 256 /**< Rotate only the error log */
#defineREFRESH_ENGINE_LOG 512 /**< Flush all storage engine logs */
#defineREFRESH_BINARY_LOG 1024 /**< Flush the binary log */
#defineREFRESH_RELAY_LOG 2048 /**< Flush the relay log */
#defineREFRESH_GENERAL_LOG 4096 /**< Flush the general log */
#defineREFRESH_SLOW_LOG 8192 /**< Flush the slow query log */
#defineREFRESH_READ_LOCK 16384 /**< Lock tables for read. */
/**
 Wait for an impending flush before closing the tables.

 @sa REFRESH_READ_LOCK, handle_reload_request, close_cached_tables
*/
#defineREFRESH_FAST 32768
#defineREFRESH_USER_RESOURCES \
 0x80000L /** FLUSH RESOURCES. @sa ::reset_mqh \
 */
#defineREFRESH_FOR_EXPORT 0x100000L /** FLUSH TABLES ... FOR EXPORT */
#defineREFRESH_OPTIMIZER_COSTS 0x200000L /** FLUSH OPTIMIZER_COSTS */
#defineREFRESH_PERSIST 0x400000L /** RESET PERSIST */

/** @}*/

/**
 @defgroup group_cs_capabilities_flags Capabilities Flags
 @ingroup group_cs

 @brief Values for the capabilities flag bitmask used by the MySQL protocol

 Currently need to fit into 32 bits.

 Each bit represents an optional feature of the protocol.

 Both the client and the server are sending these.

 The intersection of the two determines whast optional parts of the
 protocol will be used.
*/

/**
 @addtogroup group_cs_capabilities_flags
 @{
*/

/**
 Use the improved version of Old Password Authentication.

 Not used.

 @note Assumed to be set since 4.1.1.
*/
#defineCLIENT_LONG_PASSWORD 1
/**
 Send found rows instead of affected rows in @ref
 page_protocol_basic_eof_packet
*/
#defineCLIENT_FOUND_ROWS 2
/**
 @brief Get all column flags

 Longer flags in Protocol::ColumnDefinition320.

 @todo Reference Protocol::ColumnDefinition320

 Server
 ------

 Supports longer flags.

 Client
 ------

 Expects longer flags.
*/
#defineCLIENT_LONG_FLAG 4
/**
 Database (schema) name can be specified on connect in Handshake Response
 Packet.

 @todo Reference Handshake Response Packet.

 Server
 ------

 Supports schema-name in Handshake Response Packet.

 Client
 ------

 Handshake Response Packet contains a schema-name.

 @sa send_client_reply_packet()
*/
#defineCLIENT_CONNECT_WITH_DB 8
#defineCLIENT_NO_SCHEMA \
 16 /**< DEPRECATED: Don't allow database.table.column */
/**
 Compression protocol supported.

 @todo Reference Compression

 Server
 ------

 Supports compression.

 Client
 ------

 Switches to Compression compressed protocol after successful authentication.
*/
#defineCLIENT_COMPRESS 32
/**
 Special handling of ODBC behavior.

 @note No special behavior since 3.22.
*/
#defineCLIENT_ODBC 64
/**
 Can use LOAD DATA LOCAL.

 Server
 ------

 Enables the LOCAL INFILE request of LOAD DATA|XML.

 Client
 ------

 Will handle LOCAL INFILE request.
*/
#defineCLIENT_LOCAL_FILES 128
/**
 Ignore spaces before '('

 Server
 ------

 Parser can ignore spaces before '('.

 Client
 ------

 Let the parser ignore spaces before '('.
*/
#defineCLIENT_IGNORE_SPACE 256
/**
 New 4.1 protocol

 @todo Reference the new 4.1 protocol

 Server
 ------

 Supports the 4.1 protocol.

 Client
 ------

 Uses the 4.1 protocol.

 @note this value was CLIENT_CHANGE_USER in 3.22, unused in 4.0
*/
#defineCLIENT_PROTOCOL_41 512
/**
 This is an interactive client

 Use @ref System_variables::net_wait_timeout
 versus @ref System_variables::net_interactive_timeout.

 Server
 ------

 Supports interactive and noninteractive clients.

 Client
 ------

 Client is interactive.

 @sa mysql_real_connect()
*/
#defineCLIENT_INTERACTIVE 1024
/**
 Use SSL encryption for the session

 @todo Reference SSL

 Server
 ------

 Supports SSL

 Client
 ------

 Switch to SSL after sending the capability-flags.
*/
#defineCLIENT_SSL 2048
/**
 Client only flag. Not used.

 Client
 ------

 Do not issue SIGPIPE if network failures occur (libmysqlclient only).

 @sa mysql_real_connect()
*/
#defineCLIENT_IGNORE_SIGPIPE 4096
/**
 Client knows about transactions

 Server
 ------

 Can send status flags in @ref page_protocol_basic_ok_packet /
 @ref page_protocol_basic_eof_packet.

 Client
 ------

 Expects status flags in @ref page_protocol_basic_ok_packet /
 @ref page_protocol_basic_eof_packet.

 @note This flag is optional in 3.23, but always set by the server since 4.0.
 @sa send_server_handshake_packet(), parse_client_handshake_packet(),
 net_send_ok(), net_send_eof()
*/
#defineCLIENT_TRANSACTIONS 8192
#defineCLIENT_RESERVED 16384 /**< DEPRECATED: Old flag for 4.1 protocol */
#defineCLIENT_RESERVED2 \
 32768 /**< DEPRECATED: Old flag for 4.1 authentication \
 CLIENT_SECURE_CONNECTION */
/**
 Enable/disable multi-stmt support

 Also sets @ref CLIENT_MULTI_RESULTS. Currently not checked anywhere.

 Server
 ------

 Can handle multiple statements per COM_QUERY and COM_STMT_PREPARE.

 Client
 -------

 May send multiple statements per COM_QUERY and COM_STMT_PREPARE.

 @note Was named ::CLIENT_MULTI_QUERIES in 4.1.0, renamed later.

 Requires
 --------

 ::CLIENT_PROTOCOL_41

 @todo Reference COM_QUERY and COM_STMT_PREPARE
*/
#defineCLIENT_MULTI_STATEMENTS (1UL << 16)
/**
 Enable/disable multi-results

 Server
 ------

 Can send multiple resultsets for COM_QUERY.
 Error if the server needs to send them and client
 does not support them.

 Client
 -------

 Can handle multiple resultsets for COM_QUERY.

 Requires
 --------

 ::CLIENT_PROTOCOL_41

 @sa mysql_execute_command(), sp_head::MULTI_RESULTS
*/
#defineCLIENT_MULTI_RESULTS (1UL << 17)
/**
 Multi-results and OUT parameters in PS-protocol.

 Server
 ------

 Can send multiple resultsets for COM_STMT_EXECUTE.

 Client
 ------

 Can handle multiple resultsets for COM_STMT_EXECUTE.

 Requires
 --------

 ::CLIENT_PROTOCOL_41

 @todo Reference COM_STMT_EXECUTE and PS-protocol

 @sa Protocol_binary::send_out_parameters
*/
#defineCLIENT_PS_MULTI_RESULTS (1UL << 18)

/**
 Client supports plugin authentication

 Server
 ------

 Sends extra data in Initial Handshake Packet and supports the pluggable
 authentication protocol.

 Client
 ------

 Supports authentication plugins.

 Requires
 --------

 ::CLIENT_PROTOCOL_41

 @todo Reference plugin authentication, Initial Handshake Packet,
 Authentication plugins

 @sa send_change_user_packet(), send_client_reply_packet(), run_plugin_auth(),
 parse_com_change_user_packet(), parse_client_handshake_packet()
*/
#defineCLIENT_PLUGIN_AUTH (1UL << 19)
/**
 Client supports connection attributes

 Server
 ------

 Permits connection attributes in Protocol::HandshakeResponse41.

 Client
 ------

 Sends connection attributes in Protocol::HandshakeResponse41.

 @todo Reference Protocol::HandshakeResponse41

 @sa send_client_connect_attrs(), read_client_connect_attrs()
*/
#defineCLIENT_CONNECT_ATTRS (1UL << 20)

/**
 Enable authentication response packet to be larger than 255 bytes.

 When the ability to change default plugin require that the initial password
 field in the Protocol::HandshakeResponse41 paclet can be of arbitrary size.
 However, the 4.1 client-server protocol limits the length of the
 auth-data-field sent from client to server to 255 bytes.
 The solution is to change the type of the field to a true length encoded
 string and indicate the protocol change
 with this client capability flag.

 Server
 ------

 Understands length-encoded integer for auth response data in
 Protocol::HandshakeResponse41.

 Client
 ------

 Length of auth response data in Protocol::HandshakeResponse41
 is a length-encoded integer.

 @todo Reference Protocol::HandshakeResponse41

 @note The flag was introduced in 5.6.6, but had the wrong value.

 @sa send_client_reply_packet(), parse_client_handshake_packet(),
 get_56_lenc_string(), get_41_lenc_string()
*/
#defineCLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA (1UL << 21)

/**
 Don't close the connection for a user account with expired password.

 Server
 ------

 Announces support for expired password extension.

 Client
 ------

 Can handle expired passwords.

 @todo Reference expired password

 @sa MYSQL_OPT_CAN_HANDLE_EXPIRED_PASSWORDS, disconnect_on_expired_password
 ACL_USER::password_expired, check_password_lifetime(), acl_authenticate()
*/
#defineCLIENT_CAN_HANDLE_EXPIRED_PASSWORDS (1UL << 22)

/**
 Capable of handling server state change information. Its a hint to the
 server to include the state change information in
 @ref page_protocol_basic_ok_packet.

 Server
 ------
 Can set ::SERVER_SESSION_STATE_CHANGED in the ::SERVER_STATUS_flags_enum
 and send @ref sect_protocol_basic_ok_packet_sessinfo in a
 @ref page_protocol_basic_ok_packet.

 Client
 ------

 Expects the server to send @ref sect_protocol_basic_ok_packet_sessinfo in
 a @ref page_protocol_basic_ok_packet.

 @sa enum_session_state_type, read_ok_ex(), net_send_ok(), Session_tracker,
 State_tracker
*/
#defineCLIENT_SESSION_TRACK (1UL << 23)
/**
 Client no longer needs @ref page_protocol_basic_eof_packet and will
 use @ref page_protocol_basic_ok_packet instead.
 @sa net_send_ok()

 Server
 ------

 Can send OK after a Text Resultset.

 Client
 ------

 Expects an @ref page_protocol_basic_ok_packet (instead of
 @ref page_protocol_basic_eof_packet) after the resultset rows of a
 Text Resultset.

 Background
 ----------

 To support ::CLIENT_SESSION_TRACK, additional information must be sent after
 all successful commands. Although the @ref page_protocol_basic_ok_packet is
 extensible, the @ref page_protocol_basic_eof_packet is not due to the overlap
 of its bytes with the content of the Text Resultset Row.

 Therefore, the @ref page_protocol_basic_eof_packet in the
 Text Resultset is replaced with an @ref page_protocol_basic_ok_packet.
 @ref page_protocol_basic_eof_packet is deprecated as of MySQL 5.7.5.

 @todo Reference Text Resultset

 @sa cli_safe_read_with_ok(), read_ok_ex(), net_send_ok(), net_send_eof()
*/
#defineCLIENT_DEPRECATE_EOF (1UL << 24)

/**
 The client can handle optional metadata information in the resultset.
*/
#defineCLIENT_OPTIONAL_RESULTSET_METADATA (1UL << 25)

/**
 Compression protocol extended to support zstd compression method

 This capability flag is used to send zstd compression level between
 client and server provided both client and server are enabled with
 this flag.

 Server
 ------
 Server sets this flag when global variable protocol-compression-algorithms
 has zstd in its list of supported values.

 Client
 ------
 Client sets this flag when it is configured to use zstd compression method.

*/
#defineCLIENT_ZSTD_COMPRESSION_ALGORITHM (1UL << 26)

/**
 Support optional extension for query parameters into the @ref
 page_protocol_com_query and @ref page_protocol_com_stmt_execute packets.

 Server
 ------

 Expects an optional part containing the query parameter set(s). Executes the
 query for each set of parameters or returns an error if more than 1 set of
 parameters is sent and the server can't execute it.

 Client
 ------

 Can send the optional part containing the query parameter set(s).
*/
#defineCLIENT_QUERY_ATTRIBUTES (1UL << 27)

/**
 Support Multi factor authentication.

 Server
 ------
 Server sends AuthNextFactor packet after every nth factor authentication
 method succeeds, except the last factor authentication.

 Client
 ------
 Client reads AuthNextFactor packet sent by server and initiates next factor
 authentication method.
*/
#defineMULTI_FACTOR_AUTHENTICATION (1UL << 28)

/**
 This flag will be reserved to extend the 32bit capabilities structure to
 64bits.
*/
#defineCLIENT_CAPABILITY_EXTENSION (1UL << 29)

/**
 Verify server certificate.

 Client only flag.

 @deprecated in favor of --ssl-mode.
*/
#defineCLIENT_SSL_VERIFY_SERVER_CERT (1UL << 30)

/**
 Don't reset the options after an unsuccessful connect

 Client only flag.

 Typically passed via ::mysql_real_connect() 's client_flag parameter.

 @sa mysql_real_connect()
*/
#defineCLIENT_REMEMBER_OPTIONS (1UL << 31)
/** @}*/

/** a compatibility alias for CLIENT_COMPRESS */
#defineCAN_CLIENT_COMPRESS CLIENT_COMPRESS

/** Gather all possible capabilities (flags) supported by the server */
#defineCLIENT_ALL_FLAGS \
 (CLIENT_LONG_PASSWORD | CLIENT_FOUND_ROWS | CLIENT_LONG_FLAG | \
 CLIENT_CONNECT_WITH_DB | CLIENT_NO_SCHEMA | CLIENT_COMPRESS | CLIENT_ODBC | \
 CLIENT_LOCAL_FILES | CLIENT_IGNORE_SPACE | CLIENT_PROTOCOL_41 | \
 CLIENT_INTERACTIVE | CLIENT_SSL | CLIENT_IGNORE_SIGPIPE | \
 CLIENT_TRANSACTIONS | CLIENT_RESERVED | CLIENT_RESERVED2 | \
 CLIENT_MULTI_STATEMENTS | CLIENT_MULTI_RESULTS | CLIENT_PS_MULTI_RESULTS | \
 CLIENT_SSL_VERIFY_SERVER_CERT | CLIENT_REMEMBER_OPTIONS | \
 CLIENT_PLUGIN_AUTH | CLIENT_CONNECT_ATTRS | \
 CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA | \
 CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS | CLIENT_SESSION_TRACK | \
 CLIENT_DEPRECATE_EOF | CLIENT_OPTIONAL_RESULTSET_METADATA | \
 CLIENT_ZSTD_COMPRESSION_ALGORITHM | CLIENT_QUERY_ATTRIBUTES | \
 MULTI_FACTOR_AUTHENTICATION)

/**
 Switch off from ::CLIENT_ALL_FLAGS the flags that are optional and
 depending on build flags.
 If any of the optional flags is supported by the build it will be switched
 on before sending to the client during the connection handshake.
*/
#defineCLIENT_BASIC_FLAGS \
 (CLIENT_ALL_FLAGS & \
 ~(CLIENT_SSL | CLIENT_COMPRESS | CLIENT_SSL_VERIFY_SERVER_CERT | \
 CLIENT_ZSTD_COMPRESSION_ALGORITHM))

/** The status flags are a bit-field */
enumSERVER_STATUS_flags_enum {
/**
 Is raised when a multi-statement transaction
 has been started, either explicitly, by means
 of BEGIN or COMMIT AND CHAIN, or
 implicitly, by the first transactional
 statement, when autocommit=off.
 */
SERVER_STATUS_IN_TRANS=1,
SERVER_STATUS_AUTOCOMMIT=2, /**< Server in auto_commit mode */
SERVER_MORE_RESULTS_EXISTS=8, /**< Multi query - next query exists */
SERVER_QUERY_NO_GOOD_INDEX_USED=16,
SERVER_QUERY_NO_INDEX_USED=32,
/**
 The server was able to fulfill the clients request and opened a
 read-only non-scrollable cursor for a query. This flag comes
 in reply to COM_STMT_EXECUTE and COM_STMT_FETCH commands.
 Used by Binary Protocol Resultset to signal that COM_STMT_FETCH
 must be used to fetch the row-data.
 @todo Refify "Binary Protocol Resultset" and "COM_STMT_FETCH".
 */
SERVER_STATUS_CURSOR_EXISTS=64,
/**
 This flag is sent when a read-only cursor is exhausted, in reply to
 COM_STMT_FETCH command.
 */
SERVER_STATUS_LAST_ROW_SENT=128,
SERVER_STATUS_DB_DROPPED=256, /**< A database was dropped */
SERVER_STATUS_NO_BACKSLASH_ESCAPES=512,
/**
 Sent to the client if after a prepared statement reprepare
 we discovered that the new statement returns a different
 number of result set columns.
 */
SERVER_STATUS_METADATA_CHANGED=1024,
SERVER_QUERY_WAS_SLOW=2048,
/**
 To mark ResultSet containing output parameter values.
 */
SERVER_PS_OUT_PARAMS=4096,

/**
 Set at the same time as SERVER_STATUS_IN_TRANS if the started
 multi-statement transaction is a read-only transaction. Cleared
 when the transaction commits or aborts. Since this flag is sent
 to clients in OK and EOF packets, the flag indicates the
 transaction status at the end of command execution.
 */
SERVER_STATUS_IN_TRANS_READONLY=8192,

/**
 This status flag, when on, implies that one of the state information has
 changed on the server because of the execution of the last statement.
 */
SERVER_SESSION_STATE_CHANGED= (1UL << 14)
};

/**
 Server status flags that must be cleared when starting
 execution of a new SQL statement.
 Flags from this set are only added to the
 current server status by the execution engine, but
 never removed -- the execution engine expects them
 to disappear automagically by the next command.
*/
#defineSERVER_STATUS_CLEAR_SET \
 (SERVER_QUERY_NO_GOOD_INDEX_USED | SERVER_QUERY_NO_INDEX_USED | \
 SERVER_MORE_RESULTS_EXISTS | SERVER_STATUS_METADATA_CHANGED | \
 SERVER_QUERY_WAS_SLOW | SERVER_STATUS_DB_DROPPED | \
 SERVER_STATUS_CURSOR_EXISTS | SERVER_STATUS_LAST_ROW_SENT | \
 SERVER_SESSION_STATE_CHANGED)

/** Max length of a error message. Should be kept in sync with ::ERRMSGSIZE. */
#defineMYSQL_ERRMSG_SIZE 512
#defineNET_READ_TIMEOUT 30 /**< Timeout on read */
#defineNET_WRITE_TIMEOUT 60 /**< Timeout on write */
#defineNET_WAIT_TIMEOUT 8 * 60 * 60 /**< Wait for new query */

/**
 Flag used by the parser. Kill only the query and not the connection.

 @sa SQLCOM_KILL, sql_kill(), LEX::type
*/
#defineONLY_KILL_QUERY 1

#ifndefMYSQL_VIO
structVio;
#defineMYSQL_VIO struct Vio *
#endif

#defineMAX_TINYINT_WIDTH 3 /**< Max width for a TINY w.o. sign */
#defineMAX_SMALLINT_WIDTH 5 /**< Max width for a SHORT w.o. sign */
#defineMAX_MEDIUMINT_WIDTH 8 /**< Max width for a INT24 w.o. sign */
#defineMAX_INT_WIDTH 10 /**< Max width for a LONG w.o. sign */
#defineMAX_BIGINT_WIDTH 20 /**< Max width for a LONGLONG */
/// Max width for a CHAR column, in number of characters
#defineMAX_CHAR_WIDTH 255
/// Default width for blob in bytes @todo - align this with sizes from field.h
#defineMAX_BLOB_WIDTH 16777216

#defineNET_ERROR_UNSET 0 /**< No error has occurred yet */
#defineNET_ERROR_SOCKET_RECOVERABLE 1 /**< Socket still usable */
#defineNET_ERROR_SOCKET_UNUSABLE 2 /**< Do not use the socket */
#defineNET_ERROR_SOCKET_NOT_READABLE 3 /**< Try write and close socket */
#defineNET_ERROR_SOCKET_NOT_WRITABLE 4 /**< Try read and close socket */

typedefstructNET {
MYSQL_VIOvio;
unsigned char*buff, *buff_end, *write_pos, *read_pos;
my_socketfd; /* For Perl DBI/dbd */
/**
 Set if we are doing several queries in one
 command ( as in LOAD TABLE ... FROM MASTER ),
 and do not want to confuse the client with OK at the wrong time
 */
unsigned longremain_in_buf, length, buf_length, where_b;
unsigned longmax_packet, max_packet_size;
unsigned intpkt_nr, compress_pkt_nr;
unsigned intwrite_timeout, read_timeout, retry_count;
intfcntl;
unsigned int*return_status;
unsigned charreading_or_writing;
unsigned charsave_char;
boolcompress;
unsigned intlast_errno;
unsigned charerror;
/** Client library error message buffer. Actually belongs to struct MYSQL. */
charlast_error[MYSQL_ERRMSG_SIZE];
/** Client library sqlstate buffer. Set along with the error message. */
charsqlstate[SQLSTATE_LENGTH+1];
/**
 Extension pointer, for the caller private use.
 Any program linking with the networking library can use this pointer,
 which is handy when private connection specific data needs to be
 maintained.
 The mysqld server process uses this pointer internally,
 to maintain the server internal instrumentation for the connection.
 */
void*extension;
} NET;

#definepacket_error (~(unsigned long)0)

/**
 @addtogroup group_cs_backward_compatibility Backward compatibility
 @ingroup group_cs
 @{
*/
#defineCLIENT_MULTI_QUERIES CLIENT_MULTI_STATEMENTS
#defineFIELD_TYPE_DECIMAL MYSQL_TYPE_DECIMAL
#defineFIELD_TYPE_NEWDECIMAL MYSQL_TYPE_NEWDECIMAL
#defineFIELD_TYPE_TINY MYSQL_TYPE_TINY
#defineFIELD_TYPE_SHORT MYSQL_TYPE_SHORT
#defineFIELD_TYPE_LONG MYSQL_TYPE_LONG
#defineFIELD_TYPE_FLOAT MYSQL_TYPE_FLOAT
#defineFIELD_TYPE_DOUBLE MYSQL_TYPE_DOUBLE
#defineFIELD_TYPE_NULL MYSQL_TYPE_NULL
#defineFIELD_TYPE_TIMESTAMP MYSQL_TYPE_TIMESTAMP
#defineFIELD_TYPE_LONGLONG MYSQL_TYPE_LONGLONG
#defineFIELD_TYPE_INT24 MYSQL_TYPE_INT24
#defineFIELD_TYPE_DATE MYSQL_TYPE_DATE
#defineFIELD_TYPE_TIME MYSQL_TYPE_TIME
#defineFIELD_TYPE_DATETIME MYSQL_TYPE_DATETIME
#defineFIELD_TYPE_YEAR MYSQL_TYPE_YEAR
#defineFIELD_TYPE_NEWDATE MYSQL_TYPE_NEWDATE
#defineFIELD_TYPE_ENUM MYSQL_TYPE_ENUM
#defineFIELD_TYPE_SET MYSQL_TYPE_SET
#defineFIELD_TYPE_TINY_BLOB MYSQL_TYPE_TINY_BLOB
#defineFIELD_TYPE_MEDIUM_BLOB MYSQL_TYPE_MEDIUM_BLOB
#defineFIELD_TYPE_LONG_BLOB MYSQL_TYPE_LONG_BLOB
#defineFIELD_TYPE_BLOB MYSQL_TYPE_BLOB
#defineFIELD_TYPE_VAR_STRING MYSQL_TYPE_VAR_STRING
#defineFIELD_TYPE_STRING MYSQL_TYPE_STRING
#defineFIELD_TYPE_CHAR MYSQL_TYPE_TINY
#defineFIELD_TYPE_INTERVAL MYSQL_TYPE_ENUM
#defineFIELD_TYPE_GEOMETRY MYSQL_TYPE_GEOMETRY
#defineFIELD_TYPE_BIT MYSQL_TYPE_BIT
/** @}*/

/**
 @addtogroup group_cs_shutdown_kill_constants Shutdown/kill enums and constants
 @ingroup group_cs

 @sa THD::is_killable
 @{
*/
#defineMYSQL_SHUTDOWN_KILLABLE_CONNECT (unsigned char)(1 << 0)
#defineMYSQL_SHUTDOWN_KILLABLE_TRANS (unsigned char)(1 << 1)
#defineMYSQL_SHUTDOWN_KILLABLE_LOCK_TABLE (unsigned char)(1 << 2)
#defineMYSQL_SHUTDOWN_KILLABLE_UPDATE (unsigned char)(1 << 3)