Redirection client support

include/ma_common.h

@@ -79,6 +79,7 @@ struct st_mysql_options_extension {
   char *proxy_header;
   size_t proxy_header_len;
   int (*io_wait)(my_socket handle, my_bool is_read, int timeout);
+  enable_redirect redirection_mode;
 };
 
 typedef struct st_connection_handler

include/mysql.h

@@ -245,7 +245,8 @@ extern const char *SQLSTATE_UNKNOWN;
     MARIADB_OPT_MULTI_STATEMENTS,
     MARIADB_OPT_INTERACTIVE,
     MARIADB_OPT_PROXY_HEADER,
-    MARIADB_OPT_IO_WAIT
+    MARIADB_OPT_IO_WAIT,
+    MARIADB_OPT_USE_REDIRECTION
   };
 
   enum mariadb_value {
@@ -302,6 +303,13 @@ extern const char *SQLSTATE_UNKNOWN;
     MYSQL_PROTOCOL_PIPE, MYSQL_PROTOCOL_MEMORY
   };
 
+  typedef enum mariadb_redirection_mode
+  {
+      REDIRECTION_OFF,
+      REDIRECTION_ON,
+      REDIRECTION_PREFERRED
+  } enable_redirect;
+
 struct st_mysql_options {
     unsigned int connect_timeout, read_timeout, write_timeout;
     unsigned int port, protocol;

libmariadb/mariadb_lib.c

@@ -3053,6 +3053,9 @@ mysql_optionsv(MYSQL *mysql,enum mysql_option option, ...)
       mysql->options.extension->connect_attrs_len= 0;
     }
     break;
+  case MARIADB_OPT_USE_REDIRECTION:
+    OPT_SET_EXTENDED_VALUE(&mysql->options, redirection_mode, *(enable_redirect*)arg1);
+    break;
   case MARIADB_OPT_CONNECTION_HANDLER:
     OPT_SET_EXTENDED_VALUE_STR(&mysql->options, connection_handler, (char *)arg1);
     break;
@@ -3416,6 +3419,9 @@ mysql_get_optionv(MYSQL *mysql, enum mysql_option option, void *arg, ...)
   case MYSQL_OPT_BIND:
     *((char **)arg)= mysql->options.bind_address;
     break;
+  case MARIADB_OPT_USE_REDIRECTION:
+    *((enable_redirect *)arg) = mysql->options.extension ? mysql->options.extension->redirection_mode : REDIRECTION_OFF;
+    break;
   case MARIADB_OPT_TLS_CIPHER_STRENGTH:
     *((unsigned int *)arg) = mysql->options.extension ? mysql->options.extension->tls_cipher_strength : 0;
     break;

plugins/connection/CMakeLists.txt

@@ -11,3 +11,11 @@ REGISTER_PLUGIN(TARGET replication
                 CONFIGURATIONS STATIC DYNAMIC OFF
                 DEFAULT OFF
                 SOURCES ${CC_SOURCE_DIR}/plugins/connection/replication.c)
+
+# Redirection
+REGISTER_PLUGIN(TARGET redirection
+                TYPE MARIADB_CLIENT_PLUGIN_CONNECTION
+                CONFIGURATIONS STATIC DYNAMIC OFF
+                DEFAULT DYNAMIC
+                SOURCES ${CC_SOURCE_DIR}/plugins/connection/redirection.c
+                ${CC_SOURCE_DIR}/plugins/connection/redirection_utility.c) 

plugins/connection/redirection.c

@@ -0,0 +1,114 @@
+/************************************************************************************
+	Copyright (C) 2020 MariaDB Corporation AB
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with this library; if not see <http://www.gnu.org/licenses>
+   or write to the Free Software Foundation, Inc.,
+   51 Franklin St., Fifth Floor, Boston, MA 02110, USA
+*************************************************************************************/
+/* MariaDB Connection plugin for redirection. */
+#include <ma_global.h>
+#include <ma_sys.h>
+#include <errmsg.h>
+#include <mysql.h>
+#include <mysql/client_plugin.h>
+#include <string.h>
+#include <ma_string.h>
+#include <ma_common.h>
+#include "redirection_utility.h"
+#ifndef WIN32
+#include <sys/time.h>
+#endif
+/* redirection function declaration */
+int redirection_init(char* errbuf, size_t buf_size, int argc, va_list argv);
+MYSQL* redirection_connect(
+	MYSQL* mysql,
+	const char* host,
+	const char* user,
+	const char* passwd,
+	const char* db,
+	unsigned int port,
+	const char* unix_socket,
+	unsigned long clientflag);
+void redirection_close(MYSQL* mysql);
+int redirection_set_connection(
+	MYSQL* mysql,
+	enum enum_server_command command,
+	const char* arg,
+	size_t length,
+	my_bool skipp_check,
+	void* opt_arg);
+
+#ifndef PLUGIN_DYNAMIC
+MARIADB_CONNECTION_PLUGIN redirection_client_plugin =
+#else
+MARIADB_CONNECTION_PLUGIN _mysql_client_plugin_declaration_ =
+#endif
+{
+  MARIADB_CLIENT_CONNECTION_PLUGIN,
+  MARIADB_CLIENT_CONNECTION_PLUGIN_INTERFACE_VERSION,
+  "redirection",
+  "Shihao Chen",
+  "MariaDB connection plugin for redirection",
+  {1, 0, 0},
+  "LGPL",
+  NULL,
+  redirection_init,
+  NULL,
+  NULL,
+  redirection_connect,
+  redirection_close,
+  NULL,
+  redirection_set_connection,
+  NULL,
+  NULL
+};
+
+int redirection_init(char* errbuf, size_t buf_size, int argc, va_list argv) {
+	return init_redirection_cache();
+}
+
+MYSQL* redirection_connect(MYSQL* mysql, const char* host, const char* user, const char* passwd,
+	const char* db, unsigned int port, const char* unix_socket, unsigned long clientflag)
+{
+	struct st_mariadb_api* libmariadb_api = mysql->methods->api;
+	if (libmariadb_api == NULL)
+	{
+		return NULL;
+	}
+
+	if (check_redirect(mysql, host, user, passwd, db, port, unix_socket, clientflag)) {
+		return mysql;
+	}
+
+	return redirect(mysql, host, user, passwd, db, port, unix_socket, clientflag);
+}
+
+void redirection_close(MYSQL* mysql)
+{
+	if (mysql != NULL)
+	{
+		mysql->extension->conn_hdlr->data = NULL;
+	}
+}
+
+int redirection_set_connection(
+	MYSQL* mysql,
+	enum enum_server_command command,
+	const char* arg,
+	size_t length,
+	my_bool skipp_check,
+	void* opt_arg)
+{
+	return 0;
+}