mysql_optionsv - Man Page

Name

mysql_optionsv - Used to set extra connect options and affect behavior of a connection

Synopsis

#include <mysql.h>

int mysql_optionsv(MYSQL * mysql,
                   enum mysql_option,
                   const void * arg,
                   ...);

Description

Used to set extra connect options and affect behavior for a connection. This function may be called multiple times to set several options. mysql_optionsv() should be called after mysql_init(3).

Options

The following table shows which variable type to use for each option.

• MYSQL_OPT_SSL_ENFORCE

Enable or disable TLS. This option can be used to enable TLS without having to provide TLS certificates, keys or CAs.

Note: currenty this does not enforce TLS like the option name would suggest. If the server does not support TLS, the protocol will fall back to unencrypted communication. To enforce the use of TLS, use MYSQL_OPT_SSL_VERIFY_SERVER_CERT instead.

• MYSQL_INIT_COMMAND

Command(s) which will be executed when connecting and reconnecting to the server.

• MYSQL_OPT_COMPRESS

Use the compressed protocol for client server communication. If the server doesn’t support compressed protocol, the default protocol will be used.

• MYSQL_OPT_CONNECT_TIMEOUT

Connect timeout in seconds. This value will be passed as an unsigned ##int## parameter.

• MYSQL_OPT_LOCAL_INFILE

Enable or disable the use of LOAD DATA LOCAL INFILE

• MYSQL_OPT_NAMED_PIPE

For Windows operating systems only: Use named pipes for client/server communication.

• MYSQL_PROGRESS_CALLBACK

Specifies a callback function which will be able to visualize the progress of certain long running statements (i.e. LOAD DATA LOCAL INFILE or ALTER TABLE). The callback function must be defined as followed:

static void report_progress(const MYSQL *mysql __attribute__((unused)),
                            uint stage, uint max_stage,
                            double progress __attribute__((unused)),
                            const char *proc_info __attribute__((unused)),
                            uint proc_info_length __attribute__((unused)))

• MYSQL_OPT_PROTOCOL

Specify the type of client/server protocol. Possible values are: MYSQL_PROTOCOL_TCP, MYSQL_PROTOCOL_SOCKET, MYSQL_PROTOCOL_PIPE and MYSQL_PROTOCOL_MEMORY.

• MYSQL_OPT_RECONNECT

Enable or disable automatic reconnect.

• MYSQL_OPT_READ_TIMEOUT

Specifies the timeout in seconds for reading packets from the server.

• MYSQL_OPT_WRITE_TIMEOUT

Specifies the timeout in seconds for sending packets to the server.

• MYSQL_READ_DEFAULT_FILE

Read options from the specified configuration file. If an empty string is passed, the default configuration files (such as /etc/my.cnf, /etc/mysql/my.cnf) will be read. By default, configuration files are not processed unless this option is specified.

• MYSQL_READ_DEFAULT_GROUP Read options from the specified group within the default configuration file or the file specified by MYSQL_READ_DEFAULT_FILE. Passing an empty string will result in all sections being processed. If no specific file is provided via MYSQL_READ_DEFAULT_FILE, all available default configuration files will be considered.

  Note: In addition to a specified group the following groups will be always processed:

  • [client]
  • [client-server]
  • [client-mariadb]
• MYSQL_REPORT_DATA_TRUNCATION

Enable or disable reporting data truncation errors for prepared statements.

• MYSQL_OPT_BIND

Specify the network interface from which to connect to MariaDB Server.

• MYSQL_PLUGIN_DIR

Specify the location of client plugins.

• MYSQL_OPT_NONBLOCK

Specify stack size for non blocking operations. The argument for MYSQL_OPT_NONBLOCK is the size of the stack used to save the state of a non-blocking operation while it is waiting for I/O and the application is doing other processing. Normally, applications will not have to change this, and it can be passed as zero to use the default value.

• MYSQL_OPT_NET_BUFFER_LENGTH

Initial network buffer size in bytes. The default value is 16777216 (16MiB).

• MYSQL_OPT_MAX_ALLOWED_PACKET

Maximum allowed packet length. The default value is 1073741824 (1GiB) on the client side. If the limit is exceeded by a packet sent by the server, an error is generated.

• MARIADB_OPT_CONNECTION_HANDLER

Specify the name of a connection handler plugin.

• MARIADB_OPT_USERDATA

Bundle user data to the current connection, e.g. for use in connection handler plugins. This option requires 4 parameters: connection, option, key and value:

mysql_optionsv(mysql, MARIADB_OPT_USERDATA, (void *)"my_key", (void *)value);

• MARIADB_OPT_CONNECTION_READ_ONLY

This option is used by connection handler plugins and indicates that the current connection will be used for read operations only.

• MYSQL_OPT_CAN_HANDLE_EXPIRED_PASSWORDS

If this option is set, the client indicates that it will be able to handle expired passwords by setting the CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS capability flag. If the password has expired and CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS is set, the server will not return an error when connecting, but put the connection in sandbox mode, where all commands will return error 1820 (ER_MUST_CHANGE_PASSWORD) unless a new password was set. This option was added in MariaDB Connector/C 3.0.4

• MARIADB_OPT_STATUS_CALLBACK

Specifies a callback function which will be called whenever the server status changes or the server sent session_track information to the client:

mysql_optionsv(mysql, MARIADB_OPT_STATUS_CALLBACK, function, data)

The callback function must be defined as follows:

    void status_callback(void *data, enum enum_mariadb_status_info type, ..)

Parameters:

    - data  Pointer passed with registration of callback function
            (usually a connection handle)
    - type  Information type  STATUS_TYPE or SESSION_TRACK_TYPE

Variadic Parameters:

 if (type == STATUS_TYPE):
    - server status (unsigned int)

 if (type == SESSION_TRACK_TYPE)
    - enum enum_session_state_type track_type - session track type

    if (track_type == SESSION_TRACK_SYSTEM_VARIABLES)
      - MARIADB_CONST_STRING *key
      - MARIADB_CONST_STRING *value

    else
      - MARIADB_CONST_STRING *value

` Note: Specifying a callback function overwrites the internal session tracking function, so API functions mysql_session_track_get_first()/next() can’t be used.

An example can be found in unittest/libmariadb/connection.c (test_status_callback)

Addid in version 3.3.2

• MARIADB_OPT_SKIP_READ_RESPONSE

Don’t read response packets in binary protocol.

Added in version 3.1.13

Replication/Binlog API options

• MARIADB_OPT_RPL_REGISTER_REPLICA

Specifies host name and port for Binlog/API. When this option was set, rpl_open() will register replica with server_id, host and port to the connected server. This information can be retrieved by SHOW SLAVE STATUS command. This option was added in version 3.3.1

TLS/SSL and Security options

• MYSQL_OPT_SSL_KEY

Specify the name of a key for a secure connection. If the key is protected with a passphrase, the passphrase needs to be specified with MARIADB_OPT_PASSPHRASE option.

• MYSQL_OPT_SSL_CERT

Specify the name of a certificate for a secure connection.

• MYSQL_OPT_SSL_CA

Specify the name of a file which contains one or more trusted CAs.

• MYSQL_OPT_SSL_CAPATH

Specify the path which contains trusted CAs.

• MYSQL_OPT_SSL_CIPHER

Specify one or more (SSLv3, TLSv1.0 or TLSv1.2) cipher suites for TLS encryption. Even if Connector/C supports TLSv1.3 protocol, it is not possible yet to specify TLSv1.3 cipher suites.

• MYSQL_OPT_SSL_CRL

Specify a file with a certificate revocation list.

• MYSQL_OPT_SSL_CRLPATH

Specify a directory with contains files with certificate revocation lists.

• MARIADB_OPT_SSL_FP

Specify the fingerprint hash of a server certificate for validation during the TLS handshake. For versions prior to 3.4.0 the hash is a SHA1 hash, for versions 3.4.0 and newer SHA256,SHA384 or SHA512.

• MARIADB_OPT_SSL_FP_LIST

Specify a file which contains one or more fingerprint hashes of server certificates for validation during the TLS handshake. For versions prior to 3.4.0 the hash is a SHA1 hash, for versions 3.4.0 and newer SHA256,SHA384 or SHA512.

• MARIADB_OPT_SSL_PASPHRASE

Specify a passphrase for a passphrase protected client key.

• MYSQL_OPT_SSL_VERIFY_SERVER_CERT

Enable (or disable) the verification of the host name against common name (CN) of the server’s host certificate.

• MYSQL_SERVER_PUBLIC_KEY

Specifies the name of the file which contains the RSA public key of the database server. The format of this file must be in PEM format. This option is used by the caching_sha2_password plugin and was added in Connector/C 3.1.0

• MARIADB_OPT_TLS_CIPHER_STRENGTH

This option is not in use anymore.

• MARIADB_OPT_RESTRICTED_AUTH

Specifies one or more comma separated authentication plugins which are allowed for authentication. If the database server asks for an authentication plugin not listed in this option, MariaDB Connector/C will return an error. This option was added in MariaDB Connector/C 3.3.0

Proxy settings

As per the proxy protocol specification, the connecting client can prefix its first packet with a proxy protocol header. The server will parse the header and assume the client’s IP address is the one set in the proxy header. * MARIADB_OPT_PROXY_HEADER - specifies the proxy header which will be prefixed to the first packet. Parameters are void * for the prefix buffer and size_t for length of the buffer:

const char *hdr="PROXY TCP4 192.168.0.1 192.168.0.11 56324 443\r\n";
mysql_optionsv(mysql, MARIADB_OPT_PROXY_HEADER, hdr,  strlen(hdr));

Connection Attributes

Connection attributes are stored in the session_connect_attrs and session_account_connect_attrsPerformance Schema tables. By default, MariaDB Connector/C sends the following connection attributes to the server: * _client_name: always “libmariadb” * _client_version: version of MariaDB Connector/C * _os: operation system * _pid: process id * _platform: e.g. x86 or x64 * _server_host: the host name (as specified in mysql_real_connect). This attribute was added in Connector/C 3.0.5

Note: If the Performance Schema is disabled, connection attributes will not be stored on server.

• MYSQL_OPT_CONNECT_ATTR_DELETE

Deletes a connection attribute for the given key.

• MYSQL_OPT_CONNECT_ATTR_ADD

Adds a key/value pair to connection attributes. The total length of the stored connection attributes is limited to a maximum of 65535 bytes.

• MYSQL_OPT_CONNECT_ATTR_RESET

Clears the current list of connection attributes.

See Also

mysql_init(3) mysql_real_connect(3)