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MaxScale/query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc
Markus Mäkelä c96bd64aa8 Rename MODULE_INFO to MXS_MODULE 
The MODULE_INFO is now the main object which is used by modules to convey
information to the MaxScale core. The MXS_MODULE name is more apt as it
now contains the actual module definition.

The old MODULES structure was moved into load_utils.c as an internal
implementation and was renamed so that it is not confused with the new
MODULE structure.
2017-01-03 18:01:14 +02:00

2597 lines
71 KiB
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/**
* @section LICENCE
*
* This file is distributed as part of the MariaDB Corporation MaxScale. It is
* free software: you can redistribute it and/or modify it under
* the terms of the GNU General Public License as published by the
* Free Software Foundation, version 2.
*
* 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 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 Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*
* Copyright MariaDB Corporation Ab
*
* @file
*
*/
#define EMBEDDED_LIBRARY
#define MYSQL_YACC
#define MYSQL_LEX012
#define MYSQL_SERVER
#if defined(MYSQL_CLIENT)
#undef MYSQL_CLIENT
#endif
#include <my_config.h>
#include <mysql.h>
#include <my_sys.h>
#include <my_global.h>
#include <my_dbug.h>
#include <my_base.h>
#include <sql_list.h>
#include <mysqld_error.h>
#include <sql_class.h>
#include <sql_lex.h>
#include <embedded_priv.h>
#include <sql_class.h>
#include <sql_lex.h>
#include <sql_parse.h>
#include <errmsg.h>
#include <client_settings.h>
// In client_settings.h mysql_server_init and mysql_server_end are defined to
// mysql_client_plugin_init and mysql_client_plugin_deinit respectively.
// Those must be undefined, so that we here really call mysql_server_[init|end].
#undef mysql_server_init
#undef mysql_server_end
#include <set_var.h>
#include <strfunc.h>
#include <item_func.h>
#include <maxscale/debug.h>
#include <maxscale/log_manager.h>
#include <maxscale/query_classifier.h>
// <maxscale/protocol/mysql.h> assumes it is being compiled agains Connector-C,
// so we need to make certain Connector-C constants visible.
#define MYSQL_COM_QUIT COM_QUIT
#define MYSQL_COM_INIT_DB COM_INIT_DB
#define MYSQL_COM_CHANGE_USER COM_CHANGE_USER
#include <maxscale/protocol/mysql.h>
#include <maxscale/gwdirs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#define MYSQL_COM_QUERY_HEADER_SIZE 5 /*< 3 bytes size, 1 sequence, 1 command */
#define MAX_QUERYBUF_SIZE 2048
typedef struct parsing_info_st
{
#if defined(SS_DEBUG)
skygw_chk_t pi_chk_top;
#endif
void* pi_handle; /*< parsing info object pointer */
char* pi_query_plain_str; /*< query as plain string */
void (*pi_done_fp)(void *); /*< clean-up function for parsing info */
QC_FIELD_INFO* field_infos;
size_t field_infos_len;
size_t field_infos_capacity;
#if defined(SS_DEBUG)
skygw_chk_t pi_chk_tail;
#endif
} parsing_info_t;
#define QTYPE_LESS_RESTRICTIVE_THAN_WRITE(t) (t<QUERY_TYPE_WRITE ? true : false)
static THD* get_or_create_thd_for_parsing(MYSQL* mysql, char* query_str);
static unsigned long set_client_flags(MYSQL* mysql);
static bool create_parse_tree(THD* thd);
static uint32_t resolve_query_type(parsing_info_t*, THD* thd);
static bool skygw_stmt_causes_implicit_commit(LEX* lex, int* autocommit_stmt);
static int is_autocommit_stmt(LEX* lex);
static parsing_info_t* parsing_info_init(void (*donefun)(void *));
static void parsing_info_set_plain_str(void* ptr, char* str);
/** Free THD context and close MYSQL */
static void parsing_info_done(void* ptr);
static TABLE_LIST* skygw_get_affected_tables(void* lexptr);
static bool ensure_query_is_parsed(GWBUF* query);
static bool parse_query(GWBUF* querybuf);
static bool query_is_parsed(GWBUF* buf);
/**
* Ensures that the query is parsed. If it is not already parsed, it
* will be parsed.
*
* @return true if the query is parsed, false otherwise.
*/
bool ensure_query_is_parsed(GWBUF* query)
{
bool parsed = query_is_parsed(query);
if (!parsed)
{
parsed = parse_query(query);
if (!parsed)
{
MXS_ERROR("Unable to parse query, out of resources?");
}
}
return parsed;
}
qc_parse_result_t qc_parse(GWBUF* querybuf)
{
bool parsed = ensure_query_is_parsed(querybuf);
// Since the query is parsed using the same parser - subject to version
// differences between the embedded library and the server - either the
// query is valid and hence correctly parsed, or the query is invalid in
// which case the server will also consider it invalid and reject it. So,
// it's always ok to claim it has been parsed.
return parsed ? QC_QUERY_PARSED : QC_QUERY_INVALID;
}
uint32_t qc_get_type(GWBUF* querybuf)
{
MYSQL* mysql;
uint32_t qtype = QUERY_TYPE_UNKNOWN;
bool succp;
ss_info_dassert(querybuf != NULL, ("querybuf is NULL"));
if (querybuf == NULL)
{
succp = false;
goto retblock;
}
succp = ensure_query_is_parsed(querybuf);
/** Read thd pointer and resolve the query type with it. */
if (succp)
{
parsing_info_t* pi;
pi = (parsing_info_t*) gwbuf_get_buffer_object_data(querybuf,
GWBUF_PARSING_INFO);
if (pi != NULL)
{
mysql = (MYSQL *) pi->pi_handle;
/** Find out the query type */
if (mysql != NULL)
{
qtype = resolve_query_type(pi, (THD *) mysql->thd);
}
}
}
retblock:
return qtype;
}
/**
* Create parsing info and try to parse the query included in the query buffer.
* Store pointer to created parse_tree_t object to buffer.
*
* @param querybuf buffer including the query and possibly the parsing information
*
* @return true if succeed, false otherwise
*/
static bool parse_query(GWBUF* querybuf)
{
bool succp;
THD* thd;
uint8_t* data;
size_t len;
char* query_str = NULL;
parsing_info_t* pi;
CHK_GWBUF(querybuf);
/** Do not parse without releasing previous parse info first */
ss_dassert(!query_is_parsed(querybuf));
if (querybuf == NULL || query_is_parsed(querybuf))
{
MXS_ERROR("Query is NULL (%p) or query is already parsed.", querybuf);
return false;
}
/** Create parsing info */
pi = parsing_info_init(parsing_info_done);
if (pi == NULL)
{
MXS_ERROR("Parsing info initialization failed.");
succp = false;
goto retblock;
}
/** Extract query and copy it to different buffer */
data = (uint8_t*) GWBUF_DATA(querybuf);
len = MYSQL_GET_PACKET_LEN(data) - 1; /*< distract 1 for packet type byte */
if (len < 1 || len >= ~((size_t) 0) - 1 || (query_str = (char *) malloc(len + 1)) == NULL)
{
/** Free parsing info data */
MXS_ERROR("Length (%lu) is 0 or query string allocation failed (%p). Buffer is %lu bytes.",
len, query_str, GWBUF_LENGTH(querybuf));
parsing_info_done(pi);
succp = false;
goto retblock;
}
memcpy(query_str, &data[5], len);
memset(&query_str[len], 0, 1);
parsing_info_set_plain_str(pi, query_str);
/** Get one or create new THD object to be use in parsing */
thd = get_or_create_thd_for_parsing((MYSQL *) pi->pi_handle, query_str);
if (thd == NULL)
{
MXS_ERROR("THD creation failed.");
/** Free parsing info data */
parsing_info_done(pi);
succp = false;
goto retblock;
}
/**
* Create parse_tree inside thd.
* thd and lex are readable even if creating parse tree fails.
*/
create_parse_tree(thd);
/** Add complete parsing info struct to the query buffer */
gwbuf_add_buffer_object(querybuf,
GWBUF_PARSING_INFO,
(void *) pi,
parsing_info_done);
succp = true;
retblock:
return succp;
}
/**
* If buffer has non-NULL gwbuf_parsing_info it is parsed and it has parsing
* information included.
*
* @param buf buffer being examined
*
* @return true or false
*/
static bool query_is_parsed(GWBUF* buf)
{
CHK_GWBUF(buf);
return (buf != NULL && GWBUF_IS_PARSED(buf));
}
/**
* Create a thread context, thd, init embedded server, connect to it, and allocate
* query to thd.
*
* Parameters:
* @param mysql Database handle
*
* @param query_str Query in plain txt string
*
* @return Thread context pointer
*
*/
static THD* get_or_create_thd_for_parsing(MYSQL* mysql, char* query_str)
{
THD* thd = NULL;
unsigned long client_flags;
char* db = mysql->options.db;
bool failp = FALSE;
size_t query_len;
ss_info_dassert(mysql != NULL, ("mysql is NULL"));
ss_info_dassert(query_str != NULL, ("query_str is NULL"));
query_len = strlen(query_str);
client_flags = set_client_flags(mysql);
/** Get THD.
* NOTE: Instead of creating new every time, THD instance could
* be get from a pool of them.
*/
thd = (THD *) create_embedded_thd(client_flags);
if (thd == NULL)
{
MXS_ERROR("Failed to create thread context for parsing.");
goto return_thd;
}
mysql->thd = thd;
init_embedded_mysql(mysql, client_flags);
failp = check_embedded_connection(mysql, db);
if (failp)
{
MXS_ERROR("Call to check_embedded_connection failed.");
goto return_err_with_thd;
}
thd->clear_data_list();
/** Check that we are calling the client functions in right order */
if (mysql->status != MYSQL_STATUS_READY)
{
set_mysql_error(mysql, CR_COMMANDS_OUT_OF_SYNC, unknown_sqlstate);
MXS_ERROR("Invalid status %d in embedded server.",
mysql->status);
goto return_err_with_thd;
}
/** Clear result variables */
thd->current_stmt = NULL;
thd->store_globals();
/**
* We have to call free_old_query before we start to fill mysql->fields
* for new query. In the case of embedded server we collect field data
* during query execution (not during data retrieval as it is in remote
* client). So we have to call free_old_query here
*/
free_old_query(mysql);
thd->extra_length = query_len;
thd->extra_data = query_str;
alloc_query(thd, query_str, query_len);
goto return_thd;
return_err_with_thd:
(*mysql->methods->free_embedded_thd)(mysql);
thd = 0;
mysql->thd = 0;
return_thd:
return thd;
}
/**
* @node Set client flags. This is copied from libmysqld.c:mysql_real_connect
*
* Parameters:
* @param mysql - <usage>
* <description>
*
* @return
*
*
* @details (write detailed description here)
*
*/
static unsigned long set_client_flags(MYSQL* mysql)
{
unsigned long f = 0;
f |= mysql->options.client_flag;
/* Send client information for access check */
f |= CLIENT_CAPABILITIES;
if (f & CLIENT_MULTI_STATEMENTS)
{
f |= CLIENT_MULTI_RESULTS;
}
/**
* No compression in embedded as we don't send any data,
* and no pluggable auth, as we cannot do a client-server dialog
*/
f &= ~(CLIENT_COMPRESS | CLIENT_PLUGIN_AUTH);
if (mysql->options.db != NULL)
{
f |= CLIENT_CONNECT_WITH_DB;
}
return f;
}
static bool create_parse_tree(THD* thd)
{
Parser_state parser_state;
bool failp = FALSE;
const char* virtual_db = "skygw_virtual";
if (parser_state.init(thd, thd->query(), thd->query_length()))
{
failp = TRUE;
goto return_here;
}
thd->reset_for_next_command();
/**
* Set some database to thd so that parsing won't fail because of
* missing database. Then parse.
*/
failp = thd->set_db(virtual_db, strlen(virtual_db));
if (failp)
{
MXS_ERROR("Failed to set database in thread context.");
}
failp = parse_sql(thd, &parser_state, NULL);
if (failp)
{
MXS_DEBUG("%lu [readwritesplit:create_parse_tree] failed to "
"create parse tree.",
pthread_self());
}
return_here:
return failp;
}
/**
* Sniff whether the statement is
*
* SET ROLE ...
* SET NAMES ...
* SET PASSWORD ...
* SET CHARACTER ...
*
* Depending on what kind of SET statement it is, the parser of the embedded
* library creates instances of set_var_user, set_var, set_var_password,
* set_var_role, etc. that all are derived from set_var_base. However, there
* is no type-information available in set_var_base, which is the type of the
* instances when accessed from the lexer. Consequently, we cannot know what
* kind of statment it is based on that, only whether it is a system variable
* or not.
*
* Consequently, we just look at the string and deduce whether it is a
* set [ROLE|NAMES|PASSWORD|CHARACTER] statement.
*/
bool is_set_specific(const char* s)
{
bool rv = false;
// Remove space from the beginning.
while (isspace(*s))
{
++s;
}
const char* token = s;
// Find next non-space character.
while (!isspace(*s) && (*s != 0))
{
++s;
}
if (s - token == 3) // Might be "set"
{
if (strncasecmp(token, "set", 3) == 0)
{
// YES it was!
while (isspace(*s))
{
++s;
}
token = s;
while (!isspace(*s) && (*s != 0) && (*s != '='))
{
++s;
}
if (s - token == 4) // Might be "role"
{
if (strncasecmp(token, "role", 4) == 0)
{
// YES it was!
rv = true;
}
}
else if (s - token == 5) // Might be "names"
{
if (strncasecmp(token, "names", 5) == 0)
{
// YES it was!
rv = true;
}
}
else if (s - token == 8) // Might be "password
{
if (strncasecmp(token, "password", 8) == 0)
{
// YES it was!
rv = true;
}
}
else if (s - token == 9) // Might be "character"
{
if (strncasecmp(token, "character", 9) == 0)
{
// YES it was!
rv = true;
}
}
}
}
return rv;
}
/**
* Detect query type by examining parsed representation of it.
*
* @param pi The parsing info.
* @param thd MariaDB thread context.
*
* @return Copy of query type value.
*
*
* @details Query type is deduced by checking for certain properties
* of them. The order is essential. Some SQL commands have multiple
* flags set and changing the order in which flags are tested,
* the resulting type may be different.
*
*/
static uint32_t resolve_query_type(parsing_info_t *pi, THD* thd)
{
qc_query_type_t qtype = QUERY_TYPE_UNKNOWN;
uint32_t type = QUERY_TYPE_UNKNOWN;
int set_autocommit_stmt = -1; /*< -1 no, 0 disable, 1 enable */
LEX* lex;
Item* item;
/**
* By default, if sql_log_bin, that is, recording data modifications
* to binary log, is disabled, gateway treats operations normally.
* Effectively nothing is replicated.
* When force_data_modify_op_replication is TRUE, gateway distributes
* all write operations to all nodes.
*/
#if defined(NOT_IN_USE)
bool force_data_modify_op_replication;
force_data_modify_op_replication = FALSE;
#endif /* NOT_IN_USE */
ss_info_dassert(thd != NULL, ("thd is NULL\n"));
lex = thd->lex;
/** SELECT ..INTO variable|OUTFILE|DUMPFILE */
if (lex->result != NULL)
{
type = QUERY_TYPE_GSYSVAR_WRITE;
goto return_qtype;
}
if (skygw_stmt_causes_implicit_commit(lex, &set_autocommit_stmt))
{
if (MXS_LOG_PRIORITY_IS_ENABLED(LOG_INFO))
{
if (sql_command_flags[lex->sql_command] &
CF_IMPLICT_COMMIT_BEGIN)
{
MXS_INFO("Implicit COMMIT before executing the next command.");
}
else if (sql_command_flags[lex->sql_command] &
CF_IMPLICIT_COMMIT_END)
{
MXS_INFO("Implicit COMMIT after executing the next command.");
}
}
if (set_autocommit_stmt == 1)
{
type |= QUERY_TYPE_ENABLE_AUTOCOMMIT;
}
type |= QUERY_TYPE_COMMIT;
}
if (set_autocommit_stmt == 0)
{
if (MXS_LOG_PRIORITY_IS_ENABLED(LOG_INFO))
{
MXS_INFO("Disable autocommit : implicit START TRANSACTION"
" before executing the next command.");
}
type |= QUERY_TYPE_DISABLE_AUTOCOMMIT;
type |= QUERY_TYPE_BEGIN_TRX;
}
if (lex->option_type == OPT_GLOBAL)
{
/**
* SHOW syntax http://dev.mysql.com/doc/refman/5.6/en/show.html
*/
if (lex->sql_command == SQLCOM_SHOW_VARIABLES)
{
type |= QUERY_TYPE_GSYSVAR_READ;
}
/**
* SET syntax http://dev.mysql.com/doc/refman/5.6/en/set-statement.html
*/
else if (lex->sql_command == SQLCOM_SET_OPTION)
{
type |= QUERY_TYPE_GSYSVAR_WRITE;
}
/*
* SHOW GLOBAL STATUS - Route to master
*/
else if (lex->sql_command == SQLCOM_SHOW_STATUS)
{
type = QUERY_TYPE_WRITE;
}
/**
* REVOKE ALL, ASSIGN_TO_KEYCACHE,
* PRELOAD_KEYS, FLUSH, RESET, CREATE|ALTER|DROP SERVER
*/
else
{
type |= QUERY_TYPE_GSYSVAR_WRITE;
}
goto return_qtype;
}
else if (lex->option_type == OPT_SESSION)
{
/**
* SHOW syntax http://dev.mysql.com/doc/refman/5.6/en/show.html
*/
if (lex->sql_command == SQLCOM_SHOW_VARIABLES)
{
type |= QUERY_TYPE_SYSVAR_READ;
}
/**
* SET syntax http://dev.mysql.com/doc/refman/5.6/en/set-statement.html
*/
else if (lex->sql_command == SQLCOM_SET_OPTION)
{
/** Either user- or system variable write */
if (is_set_specific(pi->pi_query_plain_str))
{
type |= QUERY_TYPE_GSYSVAR_WRITE;
}
else
{
List_iterator<set_var_base> ilist(lex->var_list);
size_t n = 0;
while (set_var_base *var = ilist++)
{
if (var->is_system())
{
type |= QUERY_TYPE_GSYSVAR_WRITE;
}
else
{
type |= QUERY_TYPE_USERVAR_WRITE;
}
++n;
}
if (n == 0)
{
type |= QUERY_TYPE_GSYSVAR_WRITE;
}
}
}
goto return_qtype;
}
/**
* 1:ALTER TABLE, TRUNCATE, REPAIR, OPTIMIZE, ANALYZE, CHECK.
* 2:CREATE|ALTER|DROP|TRUNCATE|RENAME TABLE, LOAD, CREATE|DROP|ALTER DB,
* CREATE|DROP INDEX, CREATE|DROP VIEW, CREATE|DROP TRIGGER,
* CREATE|ALTER|DROP EVENT, UPDATE, INSERT, INSERT(SELECT),
* DELETE, REPLACE, REPLACE(SELECT), CREATE|RENAME|DROP USER,
* GRANT, REVOKE, OPTIMIZE, CREATE|ALTER|DROP FUNCTION|PROCEDURE,
* CREATE SPFUNCTION, INSTALL|UNINSTALL PLUGIN
*/
if (is_log_table_write_query(lex->sql_command) ||
is_update_query(lex->sql_command))
{
#if defined(NOT_IN_USE)
if (thd->variables.sql_log_bin == 0 &&
force_data_modify_op_replication)
{
/** Not replicated */
type |= QUERY_TYPE_SESSION_WRITE;
}
else
#endif /* NOT_IN_USE */
{
/** Written to binlog, that is, replicated except tmp tables */
type |= QUERY_TYPE_WRITE; /*< to master */
if (lex->sql_command == SQLCOM_CREATE_TABLE &&
(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE))
{
type |= QUERY_TYPE_CREATE_TMP_TABLE; /*< remember in router */
}
}
}
/** Try to catch session modifications here */
switch (lex->sql_command)
{
case SQLCOM_EMPTY_QUERY:
type |= QUERY_TYPE_READ;
break;
case SQLCOM_CHANGE_DB:
type |= QUERY_TYPE_SESSION_WRITE;
break;
case SQLCOM_DEALLOCATE_PREPARE:
type |= QUERY_TYPE_WRITE;
break;
case SQLCOM_SELECT:
case SQLCOM_SHOW_SLAVE_STAT:
type |= QUERY_TYPE_READ;
break;
case SQLCOM_CALL:
type |= QUERY_TYPE_WRITE;
break;
case SQLCOM_BEGIN:
type |= QUERY_TYPE_BEGIN_TRX;
if (lex->start_transaction_opt & MYSQL_START_TRANS_OPT_READ_WRITE)
{
type |= QUERY_TYPE_WRITE;
}
else if (lex->start_transaction_opt & MYSQL_START_TRANS_OPT_READ_ONLY)
{
type |= QUERY_TYPE_READ;
}
goto return_qtype;
break;
case SQLCOM_COMMIT:
type |= QUERY_TYPE_COMMIT;
goto return_qtype;
break;
case SQLCOM_ROLLBACK:
type |= QUERY_TYPE_ROLLBACK;
goto return_qtype;
break;
case SQLCOM_PREPARE:
type |= QUERY_TYPE_PREPARE_NAMED_STMT;
goto return_qtype;
break;
case SQLCOM_SHOW_DATABASES:
type |= QUERY_TYPE_SHOW_DATABASES;
goto return_qtype;
break;
case SQLCOM_SHOW_FIELDS:
type |= QUERY_TYPE_READ;
break;
case SQLCOM_SHOW_TABLES:
type |= QUERY_TYPE_SHOW_TABLES;
goto return_qtype;
break;
default:
type |= QUERY_TYPE_WRITE;
break;
}
#if defined(UPDATE_VAR_SUPPORT)
if (QTYPE_LESS_RESTRICTIVE_THAN_WRITE(type))
#endif
// TODO: This test is meaningless, since at this point
// TODO: qtype (not type) is QUERY_TYPE_UNKNOWN.
if (qc_query_is_type(qtype, QUERY_TYPE_UNKNOWN) ||
qc_query_is_type(qtype, QUERY_TYPE_LOCAL_READ) ||
qc_query_is_type(qtype, QUERY_TYPE_READ) ||
qc_query_is_type(qtype, QUERY_TYPE_USERVAR_READ) ||
qc_query_is_type(qtype, QUERY_TYPE_SYSVAR_READ) ||
qc_query_is_type(qtype, QUERY_TYPE_GSYSVAR_READ))
{
/**
* These values won't change qtype more restrictive than write.
* UDFs and procedures could possibly cause session-wide write,
* but unless their content is replicated this is a limitation
* of this implementation.
* In other words : UDFs and procedures are not allowed to
* perform writes which are not replicated but need to repeat
* in every node.
* It is not sure if such statements exist. vraa 25.10.13
*/
/**
* Search for system functions, UDFs and stored procedures.
*/
for (item = thd->free_list; item != NULL; item = item->next)
{
Item::Type itype;
itype = item->type();
MXS_DEBUG("%lu [resolve_query_type] Item %s:%s",
pthread_self(), item->name, STRITEMTYPE(itype));
if (itype == Item::SUBSELECT_ITEM)
{
continue;
}
else if (itype == Item::FUNC_ITEM)
{
int func_qtype = QUERY_TYPE_UNKNOWN;
/**
* Item types:
* FIELD_ITEM = 0, FUNC_ITEM,
* SUM_FUNC_ITEM, STRING_ITEM, INT_ITEM,
* REAL_ITEM, NULL_ITEM, VARBIN_ITEM,
* COPY_STR_ITEM, FIELD_AVG_ITEM,
* DEFAULT_VALUE_ITEM, PROC_ITEM,
* COND_ITEM, REF_ITEM, FIELD_STD_ITEM,
* FIELD_VARIANCE_ITEM,
* INSERT_VALUE_ITEM,
* SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM,
* TYPE_HOLDER, PARAM_ITEM,
* TRIGGER_FIELD_ITEM, DECIMAL_ITEM,
* XPATH_NODESET, XPATH_NODESET_CMP,
* VIEW_FIXER_ITEM,
* EXPR_CACHE_ITEM == 27
**/
Item_func::Functype ftype;
ftype = ((Item_func*) item)->functype();
/**
* Item_func types:
*
* UNKNOWN_FUNC = 0,EQ_FUNC, EQUAL_FUNC,
* NE_FUNC, LT_FUNC, LE_FUNC,
* GE_FUNC, GT_FUNC, FT_FUNC,
* LIKE_FUNC == 10, ISNULL_FUNC, ISNOTNULL_FUNC,
* COND_AND_FUNC, COND_OR_FUNC, XOR_FUNC,
* BETWEEN, IN_FUNC,
* MULT_EQUAL_FUNC, INTERVAL_FUNC,
* ISNOTNULLTEST_FUNC == 20,
* SP_EQUALS_FUNC, SP_DISJOINT_FUNC,
* SP_INTERSECTS_FUNC,
* SP_TOUCHES_FUNC, SP_CROSSES_FUNC,
* SP_WITHIN_FUNC, SP_CONTAINS_FUNC,
* SP_OVERLAPS_FUNC,
* SP_STARTPOINT, SP_ENDPOINT == 30,
* SP_EXTERIORRING, SP_POINTN, SP_GEOMETRYN,
* SP_INTERIORRINGN,NOT_FUNC, NOT_ALL_FUNC,
* NOW_FUNC, TRIG_COND_FUNC,
* SUSERVAR_FUNC, GUSERVAR_FUNC == 40,
* COLLATE_FUNC, EXTRACT_FUNC,
* CHAR_TYPECAST_FUNC,
* FUNC_SP, UDF_FUNC, NEG_FUNC,
* GSYSVAR_FUNC == 47
**/
switch (ftype)
{
case Item_func::FUNC_SP:
/**
* An unknown (for maxscale) function / sp
* belongs to this category.
*/
func_qtype |= QUERY_TYPE_WRITE;
MXS_DEBUG("%lu [resolve_query_type] "
"functype FUNC_SP, stored proc "
"or unknown function.",
pthread_self());
break;
case Item_func::UDF_FUNC:
func_qtype |= QUERY_TYPE_WRITE;
MXS_DEBUG("%lu [resolve_query_type] "
"functype UDF_FUNC, user-defined "
"function.",
pthread_self());
break;
case Item_func::NOW_FUNC:
// If this is part of a CREATE TABLE, then local read is not
// applicable.
if (lex->sql_command != SQLCOM_CREATE_TABLE)
{
func_qtype |= QUERY_TYPE_LOCAL_READ;
MXS_DEBUG("%lu [resolve_query_type] "
"functype NOW_FUNC, could be "
"executed in MaxScale.",
pthread_self());
}
break;
/** System session variable */
case Item_func::GSYSVAR_FUNC:
{
const char* name = item->name;
if (name &&
((strcasecmp(name, "@@last_insert_id") == 0) ||
(strcasecmp(name, "@@identity") == 0)))
{
func_qtype |= QUERY_TYPE_MASTER_READ;
}
else
{
func_qtype |= QUERY_TYPE_SYSVAR_READ;
}
MXS_DEBUG("%lu [resolve_query_type] "
"functype GSYSVAR_FUNC, system "
"variable read.",
pthread_self());
}
break;
/** User-defined variable read */
case Item_func::GUSERVAR_FUNC:
func_qtype |= QUERY_TYPE_USERVAR_READ;
MXS_DEBUG("%lu [resolve_query_type] "
"functype GUSERVAR_FUNC, user "
"variable read.",
pthread_self());
break;
/** User-defined variable modification */
case Item_func::SUSERVAR_FUNC:
func_qtype |= QUERY_TYPE_USERVAR_WRITE;
MXS_DEBUG("%lu [resolve_query_type] "
"functype SUSERVAR_FUNC, user "
"variable write.",
pthread_self());
break;
case Item_func::UNKNOWN_FUNC:
if (((Item_func*) item)->func_name() != NULL &&
strcmp((char*) ((Item_func*) item)->func_name(), "last_insert_id") == 0)
{
func_qtype |= QUERY_TYPE_MASTER_READ;
}
else
{
func_qtype |= QUERY_TYPE_READ;
}
/**
* Many built-in functions are of this
* type, for example, rand(), soundex(),
* repeat() .
*/
MXS_DEBUG("%lu [resolve_query_type] "
"functype UNKNOWN_FUNC, "
"typically some system function.",
pthread_self());
break;
default:
MXS_DEBUG("%lu [resolve_query_type] "
"Functype %d.",
pthread_self(),
ftype);
break;
} /**< switch */
/**< Set new query type */
type |= func_qtype;
}
#if defined(UPDATE_VAR_SUPPORT)
/**
* Write is as restrictive as it gets due functions,
* so break.
*/
if ((type & QUERY_TYPE_WRITE) == QUERY_TYPE_WRITE)
{
break;
}
#endif
} /**< for */
} /**< if */
return_qtype:
qtype = (qc_query_type_t) type;
return qtype;
}
/**
* Checks if statement causes implicit COMMIT.
* autocommit_stmt gets values 1, 0 or -1 if stmt is enable, disable or
* something else than autocommit.
*
* @param lex Parse tree
* @param autocommit_stmt memory address for autocommit status
*
* @return true if statement causes implicit commit and false otherwise
*/
static bool skygw_stmt_causes_implicit_commit(LEX* lex, int* autocommit_stmt)
{
bool succp;
if (!(sql_command_flags[lex->sql_command] & CF_AUTO_COMMIT_TRANS))
{
succp = false;
goto return_succp;
}
switch (lex->sql_command)
{
case SQLCOM_DROP_TABLE:
succp = !(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE);
break;
case SQLCOM_ALTER_TABLE:
case SQLCOM_CREATE_TABLE:
/* If CREATE TABLE of non-temporary table, do implicit commit */
succp = !(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE);
break;
case SQLCOM_SET_OPTION:
if ((*autocommit_stmt = is_autocommit_stmt(lex)) == 1)
{
succp = true;
}
else
{
succp = false;
}
break;
default:
succp = true;
break;
}
return_succp:
return succp;
}
/**
* Finds out if stmt is SET autocommit
* and if the new value matches with the enable_cmd argument.
*
* @param lex parse tree
*
* @return 1, 0, or -1 if command was:
* enable, disable, or not autocommit, respectively.
*/
static int is_autocommit_stmt(LEX* lex)
{
struct list_node* node;
set_var* setvar;
int rc = -1;
static char target[8]; /*< for converted string */
Item* item = NULL;
node = lex->var_list.first_node();
setvar = (set_var*) node->info;
if (setvar == NULL)
{
goto return_rc;
}
do /*< Search for the last occurrence of 'autocommit' */
{
if ((sys_var*) setvar->var == Sys_autocommit_ptr)
{
item = setvar->value;
}
node = node->next;
}
while ((setvar = (set_var*) node->info) != NULL);
if (item != NULL) /*< found autocommit command */
{
if (item->type() == Item::INT_ITEM) /*< '0' or '1' */
{
rc = item->val_int();
if (rc > 1 || rc < 0)
{
rc = -1;
}
}
else if (item->type() == Item::STRING_ITEM) /*< 'on' or 'off' */
{
String str(target, sizeof (target), system_charset_info);
String* res = item->val_str(&str);
if ((rc = find_type(&bool_typelib, res->ptr(), res->length(), false)))
{
ss_dassert(rc >= 0 && rc <= 2);
/**
* rc is the position of matchin string in
* typelib's value array.
* 1=OFF, 2=ON.
*/
rc -= 1;
}
}
}
return_rc:
return rc;
}
#if defined(NOT_USED)
char* qc_get_stmtname(GWBUF* buf)
{
MYSQL* mysql;
if (buf == NULL ||
buf->gwbuf_bufobj == NULL ||
buf->gwbuf_bufobj->bo_data == NULL ||
(mysql = (MYSQL *) ((parsing_info_t *) buf->gwbuf_bufobj->bo_data)->pi_handle) == NULL ||
mysql->thd == NULL ||
(THD *) (mysql->thd))->lex == NULL ||
(THD *) (mysql->thd))->lex->prepared_stmt_name == NULL)
{
return NULL;
}
return ((THD *) (mysql->thd))->lex->prepared_stmt_name.str;
}
#endif
/**
* Get the parsing info structure from a GWBUF
*
* @param querybuf A GWBUF
*
* @return The parsing info object, or NULL
*/
parsing_info_t* get_pinfo(GWBUF* querybuf)
{
parsing_info_t *pi = NULL;
if ((querybuf != NULL) && GWBUF_IS_PARSED(querybuf))
{
pi = (parsing_info_t *) gwbuf_get_buffer_object_data(querybuf, GWBUF_PARSING_INFO);
}
return pi;
}
LEX* get_lex(parsing_info_t* pi)
{
MYSQL* mysql = (MYSQL *) pi->pi_handle;
ss_dassert(mysql);
THD* thd = (THD *) mysql->thd;
ss_dassert(thd);
return thd->lex;
}
/**
* Get the parse tree from parsed querybuf.
* @param querybuf The parsed GWBUF
*
* @return Pointer to the LEX struct or NULL if an error occurred or the query
* was not parsed
*/
LEX* get_lex(GWBUF* querybuf)
{
LEX* lex = NULL;
parsing_info_t* pi = get_pinfo(querybuf);
if (pi)
{
MYSQL* mysql = (MYSQL *) pi->pi_handle;
ss_dassert(mysql);
THD* thd = (THD *) mysql->thd;
ss_dassert(thd);
lex = thd->lex;
}
return lex;
}
/**
* Finds the head of the list of tables affected by the current select statement.
* @param thd Pointer to a valid THD
* @return Pointer to the head of the TABLE_LIST chain or NULL in case of an error
*/
static TABLE_LIST* skygw_get_affected_tables(void* lexptr)
{
LEX* lex = (LEX*) lexptr;
if (lex == NULL || lex->current_select == NULL)
{
ss_dassert(lex != NULL && lex->current_select != NULL);
return NULL;
}
TABLE_LIST *tbl = lex->current_select->table_list.first;
if (tbl && tbl->schema_select_lex && tbl->schema_select_lex->table_list.elements &&
lex->sql_command != SQLCOM_SHOW_KEYS)
{
/**
* Some statements e.g. EXPLAIN or SHOW COLUMNS give `information_schema`
* as the underlying table and the table in the query is stored in
* @c schema_select_lex.
*
* SHOW [KEYS | INDEX] does the reverse so we need to skip the
* @c schema_select_lex when processing a SHOW [KEYS | INDEX] statement.
*/
tbl = tbl->schema_select_lex->table_list.first;
}
return tbl;
}
char** qc_get_table_names(GWBUF* querybuf, int* tblsize, bool fullnames)
{
LEX* lex;
TABLE_LIST* tbl;
int i = 0, currtblsz = 0;
char **tables = NULL, **tmp = NULL;
if (querybuf == NULL || tblsize == NULL)
{
goto retblock;
}
if (!ensure_query_is_parsed(querybuf))
{
goto retblock;
}
if ((lex = get_lex(querybuf)) == NULL)
{
goto retblock;
}
lex->current_select = lex->all_selects_list;
while (lex->current_select)
{
tbl = skygw_get_affected_tables(lex);
while (tbl)
{
if (i >= currtblsz)
{
tmp = (char**) malloc(sizeof (char*)*(currtblsz * 2 + 1));
if (tmp)
{
if (currtblsz > 0)
{
for (int x = 0; x < currtblsz; x++)
{
tmp[x] = tables[x];
}
free(tables);
}
tables = tmp;
currtblsz = currtblsz * 2 + 1;
}
}
if (tmp != NULL)
{
char *catnm = NULL;
if (fullnames)
{
if (tbl->db &&
(strcmp(tbl->db, "skygw_virtual") != 0) &&
(strcmp(tbl->table_name, "*") != 0))
{
catnm = (char*) calloc(strlen(tbl->db) +
strlen(tbl->table_name) +
2,
sizeof (char));
strcpy(catnm, tbl->db);
strcat(catnm, ".");
strcat(catnm, tbl->table_name);
}
}
if (catnm)
{
tables[i++] = catnm;
}
else
{
// Sometimes the tablename is "*"; we exclude that.
if (strcmp(tbl->table_name, "*") != 0)
{
tables[i++] = strdup(tbl->table_name);
}
}
tbl = tbl->next_local;
}
} /*< while (tbl) */
lex->current_select = lex->current_select->next_select_in_list();
} /*< while(lex->current_select) */
retblock:
*tblsize = i;
return tables;
}
char* qc_get_created_table_name(GWBUF* querybuf)
{
if (querybuf == NULL)
{
return NULL;
}
if (!ensure_query_is_parsed(querybuf))
{
return NULL;
}
char* table_name = NULL;
LEX* lex = get_lex(querybuf);
if (lex && (lex->sql_command == SQLCOM_CREATE_TABLE))
{
if (lex->create_last_non_select_table &&
lex->create_last_non_select_table->table_name)
{
table_name = strdup(lex->create_last_non_select_table->table_name);
}
}
return table_name;
}
bool qc_is_real_query(GWBUF* querybuf)
{
bool succp;
LEX* lex;
if (querybuf == NULL)
{
succp = false;
goto retblock;
}
if (!ensure_query_is_parsed(querybuf))
{
succp = false;
goto retblock;
}
if ((lex = get_lex(querybuf)) == NULL)
{
succp = false;
goto retblock;
}
switch (lex->sql_command)
{
case SQLCOM_SELECT:
succp = lex->all_selects_list->table_list.elements > 0;
goto retblock;
break;
case SQLCOM_UPDATE_MULTI:
case SQLCOM_UPDATE:
case SQLCOM_INSERT:
case SQLCOM_INSERT_SELECT:
case SQLCOM_DELETE:
case SQLCOM_DELETE_MULTI:
case SQLCOM_TRUNCATE:
case SQLCOM_REPLACE:
case SQLCOM_REPLACE_SELECT:
case SQLCOM_PREPARE:
case SQLCOM_EXECUTE:
succp = true;
goto retblock;
break;
default:
succp = false;
goto retblock;
break;
}
retblock:
return succp;
}
bool qc_is_drop_table_query(GWBUF* querybuf)
{
bool answer = false;
if (querybuf)
{
if (ensure_query_is_parsed(querybuf))
{
LEX* lex = get_lex(querybuf);
answer = lex && lex->sql_command == SQLCOM_DROP_TABLE;
}
}
return answer;
}
bool qc_query_has_clause(GWBUF* buf)
{
bool clause = false;
if (buf)
{
if (ensure_query_is_parsed(buf))
{
LEX* lex = get_lex(buf);
if (lex)
{
SELECT_LEX* current = lex->all_selects_list;
while (current && !clause)
{
if (current->where || current->having)
{
clause = true;
}
current = current->next_select_in_list();
}
}
}
}
return clause;
}
/**
* Create parsing information; initialize mysql handle, allocate parsing info
* struct and set handle and free function pointer to it.
*
* @param donefun pointer to free function
*
* @return pointer to parsing information
*/
static parsing_info_t* parsing_info_init(void (*donefun)(void *))
{
parsing_info_t* pi = NULL;
MYSQL* mysql;
const char* user = "skygw";
const char* db = "skygw";
ss_dassert(donefun != NULL);
/** Get server handle */
mysql = mysql_init(NULL);
if (mysql == NULL)
{
MXS_ERROR("Call to mysql_real_connect failed due %d, %s.",
mysql_errno(mysql),
mysql_error(mysql));
ss_dassert(mysql != NULL);
goto retblock;
}
/** Set methods and authentication to mysql */
mysql_options(mysql, MYSQL_READ_DEFAULT_GROUP, "libmysqld_skygw");
mysql_options(mysql, MYSQL_OPT_USE_EMBEDDED_CONNECTION, NULL);
mysql->methods = &embedded_methods;
mysql->user = my_strdup(user, MYF(0));
mysql->db = my_strdup(db, MYF(0));
mysql->passwd = NULL;
pi = (parsing_info_t*) calloc(1, sizeof (parsing_info_t));
if (pi == NULL)
{
mysql_close(mysql);
goto retblock;
}
#if defined(SS_DEBUG)
pi->pi_chk_top = CHK_NUM_PINFO;
pi->pi_chk_tail = CHK_NUM_PINFO;
#endif
/** Set handle and free function to parsing info struct */
pi->pi_handle = mysql;
pi->pi_done_fp = donefun;
retblock:
return pi;
}
/**
* Free function for parsing info. Called by gwbuf_free or in case initialization
* of parsing information fails.
*
* @param ptr Pointer to parsing information, cast required
*
* @return void
*
*/
static void parsing_info_done(void* ptr)
{
parsing_info_t* pi;
THD* thd;
if (ptr)
{
pi = (parsing_info_t *) ptr;
if (pi->pi_handle != NULL)
{
MYSQL* mysql = (MYSQL *) pi->pi_handle;
if (mysql->thd != NULL)
{
thd = (THD*) mysql->thd;
thd->end_statement();
(*mysql->methods->free_embedded_thd)(mysql);
mysql->thd = NULL;
}
mysql_close(mysql);
}
/** Free plain text query string */
if (pi->pi_query_plain_str != NULL)
{
free(pi->pi_query_plain_str);
}
for (size_t i = 0; i < pi->field_infos_len; ++i)
{
free(pi->field_infos[i].database);
free(pi->field_infos[i].table);
free(pi->field_infos[i].column);
}
free(pi->field_infos);
free(pi);
}
}
/**
* Add plain text query string to parsing info.
*
* @param ptr Pointer to parsing info struct, cast required
* @param str String to be added
*
* @return void
*/
static void parsing_info_set_plain_str(void* ptr, char* str)
{
parsing_info_t* pi = (parsing_info_t *) ptr;
CHK_PARSING_INFO(pi);
pi->pi_query_plain_str = str;
}
char** qc_get_database_names(GWBUF* querybuf, int* size)
{
LEX* lex;
TABLE_LIST* tbl;
char **databases = NULL, **tmp = NULL;
int currsz = 0, i = 0;
if (!querybuf)
{
goto retblock;
}
if (!ensure_query_is_parsed(querybuf))
{
goto retblock;
}
if ((lex = get_lex(querybuf)) == NULL)
{
goto retblock;
}
lex->current_select = lex->all_selects_list;
while (lex->current_select)
{
tbl = lex->current_select->table_list.first;
while (tbl)
{
if (lex->sql_command == SQLCOM_SHOW_FIELDS)
{
// If we are describing, we want the actual table, not the information_schema.
if (tbl->schema_select_lex)
{
tbl = tbl->schema_select_lex->table_list.first;
}
}
// The database is sometimes an empty string. So as not to return
// an array of empty strings, we need to check for that possibility.
if ((strcmp(tbl->db, "skygw_virtual") != 0) && (*tbl->db != 0))
{
if (i >= currsz)
{
tmp = (char**) realloc(databases,
sizeof (char*)*(currsz * 2 + 1));
if (tmp == NULL)
{
goto retblock;
}
databases = tmp;
currsz = currsz * 2 + 1;
}
databases[i++] = strdup(tbl->db);
}
tbl = tbl->next_local;
}
lex->current_select = lex->current_select->next_select_in_list();
}
retblock:
*size = i;
return databases;
}
qc_query_op_t qc_get_operation(GWBUF* querybuf)
{
qc_query_op_t operation = QUERY_OP_UNDEFINED;
if (querybuf)
{
if (ensure_query_is_parsed(querybuf))
{
LEX* lex = get_lex(querybuf);
if (lex)
{
switch (lex->sql_command)
{
case SQLCOM_SELECT:
operation = QUERY_OP_SELECT;
break;
case SQLCOM_CREATE_DB:
case SQLCOM_CREATE_EVENT:
case SQLCOM_CREATE_FUNCTION:
case SQLCOM_CREATE_INDEX:
case SQLCOM_CREATE_PROCEDURE:
case SQLCOM_CREATE_SERVER:
case SQLCOM_CREATE_SPFUNCTION:
case SQLCOM_CREATE_TABLE:
case SQLCOM_CREATE_TRIGGER:
case SQLCOM_CREATE_USER:
case SQLCOM_CREATE_VIEW:
operation = QUERY_OP_CREATE;
break;
case SQLCOM_ALTER_DB:
case SQLCOM_ALTER_DB_UPGRADE:
case SQLCOM_ALTER_EVENT:
case SQLCOM_ALTER_FUNCTION:
case SQLCOM_ALTER_PROCEDURE:
case SQLCOM_ALTER_SERVER:
case SQLCOM_ALTER_TABLE:
case SQLCOM_ALTER_TABLESPACE:
operation = QUERY_OP_ALTER;
break;
case SQLCOM_UPDATE:
case SQLCOM_UPDATE_MULTI:
operation = QUERY_OP_UPDATE;
break;
case SQLCOM_INSERT:
case SQLCOM_INSERT_SELECT:
case SQLCOM_REPLACE:
case SQLCOM_REPLACE_SELECT:
operation = QUERY_OP_INSERT;
break;
case SQLCOM_DELETE:
case SQLCOM_DELETE_MULTI:
operation = QUERY_OP_DELETE;
break;
case SQLCOM_TRUNCATE:
operation = QUERY_OP_TRUNCATE;
break;
case SQLCOM_DROP_DB:
case SQLCOM_DROP_EVENT:
case SQLCOM_DROP_FUNCTION:
case SQLCOM_DROP_INDEX:
case SQLCOM_DROP_PROCEDURE:
case SQLCOM_DROP_SERVER:
case SQLCOM_DROP_TABLE:
case SQLCOM_DROP_TRIGGER:
case SQLCOM_DROP_USER:
case SQLCOM_DROP_VIEW:
operation = QUERY_OP_DROP;
break;
case SQLCOM_CHANGE_DB:
operation = QUERY_OP_CHANGE_DB;
break;
case SQLCOM_LOAD:
operation = QUERY_OP_LOAD;
break;
case SQLCOM_GRANT:
operation = QUERY_OP_GRANT;
break;
case SQLCOM_REVOKE:
case SQLCOM_REVOKE_ALL:
operation = QUERY_OP_REVOKE;
break;
default:
operation = QUERY_OP_UNDEFINED;
}
}
}
}
return operation;
}
char* qc_get_prepare_name(GWBUF* stmt)
{
char* name = NULL;
if (stmt)
{
if (ensure_query_is_parsed(stmt))
{
LEX* lex = get_lex(stmt);
if ((lex->sql_command == SQLCOM_PREPARE) ||
(lex->sql_command == SQLCOM_EXECUTE) ||
(lex->sql_command == SQLCOM_DEALLOCATE_PREPARE))
{
name = (char*)malloc(lex->prepared_stmt_name.length + 1);
if (name)
{
memcpy(name, lex->prepared_stmt_name.str, lex->prepared_stmt_name.length);
name[lex->prepared_stmt_name.length] = 0;
}
}
}
}
return name;
}
qc_query_op_t qc_get_prepare_operation(GWBUF* stmt)
{
qc_query_op_t operation = QUERY_OP_UNDEFINED;
if (stmt)
{
if (ensure_query_is_parsed(stmt))
{
LEX* lex = get_lex(stmt);
if (lex->sql_command == SQLCOM_PREPARE)
{
// This is terriby inefficient, but as qc_mysqlembedded is not used
// for anything else but comparisons it is ok.
const char* prepare_str = lex->prepared_stmt_code.str;
size_t prepare_str_len = lex->prepared_stmt_code.length;
// MySQL does not parse e.g. "select * from x where ?=5". To work
// around that we'll replace all "?":s with "@a":s. We might replace
// something unnecessarily, but that won't hurt the classification.
size_t n_questions = 0;
const char* p = prepare_str;
while (p < prepare_str + prepare_str_len)
{
if (*p == '?')
{
++n_questions;
}
++p;
}
size_t payload_len = prepare_str_len + n_questions * 2 + 1;
size_t prepare_stmt_len = MYSQL_HEADER_LEN + payload_len;
GWBUF* prepare_stmt = gwbuf_alloc(prepare_stmt_len);
if (prepare_stmt)
{
// Encode the length of the payload in the 3 first bytes.
*((unsigned char*)GWBUF_DATA(prepare_stmt) + 0) = payload_len;
*((unsigned char*)GWBUF_DATA(prepare_stmt) + 1) = (payload_len >> 8);
*((unsigned char*)GWBUF_DATA(prepare_stmt) + 2) = (payload_len >> 16);
// Sequence id
*((unsigned char*)GWBUF_DATA(prepare_stmt) + 3) = 0x00;
// Payload, starts with command.
*((unsigned char*)GWBUF_DATA(prepare_stmt) + 4) = COM_QUERY;
// Is followed by the statement.
char *s = (char*)GWBUF_DATA(prepare_stmt) + 5;
p = prepare_str;
while (p < prepare_str + prepare_str_len)
{
switch (*p)
{
case '?':
*s++ = '@';
*s = 'a';
break;
default:
*s = *p;
}
++p;
++s;
}
operation = qc_get_operation(prepare_stmt);
gwbuf_free(prepare_stmt);
}
}
}
}
return operation;
}
static bool should_exclude(const char* name, List<Item>* excludep)
{
bool exclude = false;
List_iterator<Item> ilist(*excludep);
Item* exclude_item;
while (!exclude && (exclude_item = ilist++))
{
const char* exclude_name = exclude_item->name;
if (exclude_name && (strcasecmp(name, exclude_name) == 0))
{
exclude = true;
}
if (!exclude)
{
exclude_name = strrchr(exclude_item->full_name(), '.');
if (exclude_name)
{
++exclude_name; // Char after the '.'
if (strcasecmp(name, exclude_name) == 0)
{
exclude = true;
}
}
}
}
return exclude;
}
static void add_field_info(parsing_info_t* info,
const char* database,
const char* table,
const char* column,
uint32_t usage,
List<Item>* excludep)
{
ss_dassert(column);
QC_FIELD_INFO item = { (char*)database, (char*)table, (char*)column, usage };
size_t i;
for (i = 0; i < info->field_infos_len; ++i)
{
QC_FIELD_INFO* field_info = info->field_infos + i;
if (strcasecmp(item.column, field_info->column) == 0)
{
if (!item.table && !field_info->table)
{
ss_dassert(!item.database && !field_info->database);
break;
}
else if (item.table && field_info->table && (strcmp(item.table, field_info->table) == 0))
{
if (!item.database && !field_info->database)
{
break;
}
else if (item.database &&
field_info->database &&
(strcmp(item.database, field_info->database) == 0))
{
break;
}
}
}
}
QC_FIELD_INFO* field_infos = NULL;
if (i == info->field_infos_len) // If true, the field was not present already.
{
// If only a column is specified, but not a table or database and we
// have a list of expressions that should be excluded, we check if the column
// value is present in that list. This is in order to exclude the second "d" in
// a statement like "select a as d from x where d = 2".
if (!(column && !table && !database && excludep && should_exclude(column, excludep)))
{
if (info->field_infos_len < info->field_infos_capacity)
{
field_infos = info->field_infos;
}
else
{
size_t capacity = info->field_infos_capacity ? 2 * info->field_infos_capacity : 8;
field_infos = (QC_FIELD_INFO*)realloc(info->field_infos, capacity * sizeof(QC_FIELD_INFO));
if (field_infos)
{
info->field_infos = field_infos;
info->field_infos_capacity = capacity;
}
}
}
}
else
{
info->field_infos[i].usage |= usage;
}
// If field_infos is NULL, then the field was found and has already been noted.
if (field_infos)
{
item.database = item.database ? strdup(item.database) : NULL;
item.table = item.table ? strdup(item.table) : NULL;
ss_dassert(item.column);
item.column = strdup(item.column);
// We are happy if we at least could dup the column.
if (item.column)
{
field_infos[info->field_infos_len++] = item;
}
}
}
static void add_field_info(parsing_info_t* pi, Item_field* item, uint32_t usage, List<Item>* excludep)
{
const char* database = item->db_name;
const char* table = item->table_name;
const char* column = item->field_name;
LEX* lex = get_lex(pi);
switch (lex->sql_command)
{
case SQLCOM_SHOW_FIELDS:
if (!database)
{
database = "information_schema";
}
if (!table)
{
table = "COLUMNS";
}
break;
case SQLCOM_SHOW_KEYS:
if (!database)
{
database = "information_schema";
}
if (!table)
{
table = "STATISTICS";
}
break;
case SQLCOM_SHOW_STATUS:
if (!database)
{
database = "information_schema";
}
if (!table)
{
table = "SESSION_STATUS";
}
break;
case SQLCOM_SHOW_TABLES:
if (!database)
{
database = "information_schema";
}
if (!table)
{
table = "TABLE_NAMES";
}
break;
case SQLCOM_SHOW_TABLE_STATUS:
if (!database)
{
database = "information_schema";
}
if (!table)
{
table = "TABLES";
}
break;
case SQLCOM_SHOW_VARIABLES:
if (!database)
{
database = "information_schema";
}
if (!table)
{
table = "SESSION_STATUS";
}
break;
default:
break;
}
add_field_info(pi, database, table, column, usage, excludep);
}
static void add_field_info(parsing_info_t* pi, Item* item, uint32_t usage, List<Item>* excludep)
{
const char* database = NULL;
const char* table = NULL;
const char* column = item->name;
add_field_info(pi, database, table, column, usage, excludep);
}
typedef enum collect_source
{
COLLECT_SELECT,
COLLECT_WHERE,
COLLECT_HAVING,
COLLECT_GROUP_BY,
} collect_source_t;
static void update_field_infos(parsing_info_t* pi,
LEX* lex,
st_select_lex* select,
uint32_t usage,
List<Item>* excludep);
static void update_field_infos(parsing_info_t* pi,
collect_source_t source,
Item* item,
uint32_t usage,
List<Item>* excludep)
{
switch (item->type())
{
case Item::COND_ITEM:
{
Item_cond* cond_item = static_cast<Item_cond*>(item);
List_iterator<Item> ilist(*cond_item->argument_list());
while (Item *i = ilist++)
{
update_field_infos(pi, source, i, usage, excludep);
}
}
break;
case Item::FIELD_ITEM:
add_field_info(pi, static_cast<Item_field*>(item), usage, excludep);
break;
case Item::REF_ITEM:
{
if (source != COLLECT_SELECT)
{
Item_ref* ref_item = static_cast<Item_ref*>(item);
add_field_info(pi, item, usage, excludep);
size_t n_items = ref_item->cols();
for (size_t i = 0; i < n_items; ++i)
{
Item* reffed_item = ref_item->element_index(i);
if (reffed_item != ref_item)
{
update_field_infos(pi, source, ref_item->element_index(i), usage, excludep);
}
}
}
}
break;
case Item::ROW_ITEM:
{
Item_row* row_item = static_cast<Item_row*>(item);
size_t n_items = row_item->cols();
for (size_t i = 0; i < n_items; ++i)
{
update_field_infos(pi, source, row_item->element_index(i), usage, excludep);
}
}
break;
case Item::FUNC_ITEM:
case Item::SUM_FUNC_ITEM:
{
Item_func* func_item = static_cast<Item_func*>(item);
Item** items = func_item->arguments();
size_t n_items = func_item->argument_count();
for (size_t i = 0; i < n_items; ++i)
{
update_field_infos(pi, source, items[i], usage, excludep);
}
}
break;
case Item::SUBSELECT_ITEM:
{
Item_subselect* subselect_item = static_cast<Item_subselect*>(item);
switch (subselect_item->substype())
{
case Item_subselect::IN_SUBS:
case Item_subselect::ALL_SUBS:
case Item_subselect::ANY_SUBS:
{
Item_in_subselect* in_subselect_item = static_cast<Item_in_subselect*>(item);
#if (((MYSQL_VERSION_MAJOR == 5) &&\
((MYSQL_VERSION_MINOR > 5) ||\
((MYSQL_VERSION_MINOR == 5) && (MYSQL_VERSION_PATCH >= 48))\
)\
) ||\
(MYSQL_VERSION_MAJOR >= 10)\
)
if (in_subselect_item->left_expr_orig)
{
update_field_infos(pi, source,
in_subselect_item->left_expr_orig, usage, excludep);
}
st_select_lex* ssl = in_subselect_item->get_select_lex();
if (ssl)
{
uint32_t sub_usage = usage;
sub_usage &= ~QC_USED_IN_SELECT;
sub_usage |= QC_USED_IN_SUBSELECT;
update_field_infos(pi,
get_lex(pi),
ssl,
sub_usage,
excludep);
}
#else
#pragma message "Figure out what to do with versions < 5.5.48."
#endif
// TODO: Anything else that needs to be looked into?
}
break;
case Item_subselect::EXISTS_SUBS:
// TODO: Handle these explicitly as well.
break;
case Item_subselect::SINGLEROW_SUBS:
{
Item_singlerow_subselect* ss_item = static_cast<Item_singlerow_subselect*>(item);
st_select_lex *ssl = ss_item->get_select_lex();
usage &= ~QC_USED_IN_SELECT;
usage |= QC_USED_IN_SUBSELECT;
update_field_infos(pi, get_lex(pi), ssl, usage, excludep);
}
break;
case Item_subselect::UNKNOWN_SUBS:
default:
MXS_ERROR("Unknown subselect type: %d", subselect_item->substype());
break;
}
}
break;
default:
break;
}
}
static void update_field_infos(parsing_info_t* pi,
LEX* lex,
st_select_lex* select,
uint32_t usage,
List<Item>* excludep)
{
List_iterator<Item> ilist(select->item_list);
while (Item *item = ilist++)
{
update_field_infos(pi, COLLECT_SELECT, item, usage, NULL);
}
if (select->group_list.first)
{
ORDER* order = select->group_list.first;
while (order)
{
Item* item = *order->item;
update_field_infos(pi, COLLECT_GROUP_BY, item, QC_USED_IN_GROUP_BY,
&select->item_list);
order = order->next;
}
}
if (select->where)
{
update_field_infos(pi, COLLECT_WHERE,
select->where,
QC_USED_IN_WHERE,
&select->item_list);
}
#if defined(COLLECT_HAVING_AS_WELL)
// A HAVING clause can only refer to fields that already have been
// mentioned. Consequently, they need not be collected.
if (select->having)
{
update_field_infos(pi, COLLECT_HAVING,
select->having,
0,
&select->item_list);
}
#endif
TABLE_LIST* table_list = select->get_table_list();
if (table_list)
{
st_select_lex *sl = table_list->get_single_select();
if (sl)
{
// This is for "SELECT 1 FROM (SELECT ...)"
usage &= ~QC_USED_IN_SELECT;
usage |= QC_USED_IN_SUBSELECT;
update_field_infos(pi, get_lex(pi), sl, usage, excludep);
}
}
}
void qc_get_field_info(GWBUF* buf, const QC_FIELD_INFO** infos, size_t* n_infos)
{
if (!buf)
{
return;
}
if (!ensure_query_is_parsed(buf))
{
return;
}
parsing_info_t* pi = get_pinfo(buf);
ss_dassert(pi);
if (!pi->field_infos)
{
LEX* lex = get_lex(buf);
ss_dassert(lex);
if (!lex)
{
return;
}
uint32_t usage = 0;
switch (lex->sql_command)
{
case SQLCOM_UPDATE:
case SQLCOM_UPDATE_MULTI:
usage |= QC_USED_IN_SET;
break;
default:
usage |= QC_USED_IN_SELECT;
}
lex->current_select = &lex->select_lex;
update_field_infos(pi, lex, &lex->select_lex, usage, NULL);
List_iterator<Item> ilist(lex->value_list);
while (Item* item = ilist++)
{
update_field_infos(pi, COLLECT_SELECT, item, 0, NULL);
}
if ((lex->sql_command == SQLCOM_INSERT) ||
(lex->sql_command == SQLCOM_INSERT_SELECT) ||
(lex->sql_command == SQLCOM_REPLACE))
{
List_iterator<Item> ilist(lex->field_list);
while (Item *item = ilist++)
{
update_field_infos(pi, COLLECT_SELECT, item, 0, NULL);
}
if (lex->insert_list)
{
List_iterator<Item> ilist(*lex->insert_list);
while (Item *item = ilist++)
{
update_field_infos(pi, COLLECT_SELECT, item, 0, NULL);
}
}
}
if (lex->sql_command == SQLCOM_SET_OPTION)
{
#if defined(WAY_TO_DOWNCAST_SET_VAR_BASE_EXISTS)
// The list of set_var_base contains the value of variables.
// However, the actual type is a derived type of set_var_base
// and there is no information using which we could do the
// downcast...
List_iterator<set_var_base> ilist(lex->var_list);
while (set_var_base* var = ilist++)
{
// Is set_var_base a set_var, set_var_user, set_var_password
// set_var_role
...
}
#endif
// ...so, we will simply assume that any nested selects are
// from statements like "set @a:=(SELECT a from t1)".
usage &= ~QC_USED_IN_SELECT;
usage |= QC_USED_IN_SUBSELECT;
st_select_lex* select = lex->all_selects_list;
while (select)
{
if (select->nest_level != 0) // Not the top-level select.
{
update_field_infos(pi, lex, select, usage, NULL);
}
select = select->next_select_in_list();
}
}
}
*infos = pi->field_infos;
*n_infos = pi->field_infos_len;
}
namespace
{
// Do not change the order without making corresponding changes to IDX_... below.
const char* server_options[] =
{
"MariaDB Corporation MaxScale",
"--no-defaults",
"--datadir=",
"--language=",
"--skip-innodb",
"--default-storage-engine=myisam",
NULL
};
const int IDX_DATADIR = 2;
const int IDX_LANGUAGE = 3;
const int N_OPTIONS = (sizeof(server_options) / sizeof(server_options[0])) - 1;
const char* server_groups[] = {
"embedded",
"server",
"server",
"embedded",
"server",
"server",
NULL
};
const int OPTIONS_DATADIR_SIZE = 10 + PATH_MAX; // strlen("--datadir=");
const int OPTIONS_LANGUAGE_SIZE = 11 + PATH_MAX; // strlen("--language=");
char datadir_arg[OPTIONS_DATADIR_SIZE];
char language_arg[OPTIONS_LANGUAGE_SIZE];
void configure_options(const char* datadir, const char* langdir)
{
int rv;
rv = snprintf(datadir_arg, OPTIONS_DATADIR_SIZE, "--datadir=%s", datadir);
ss_dassert(rv < OPTIONS_DATADIR_SIZE); // Ensured by create_datadir().
server_options[IDX_DATADIR] = datadir_arg;
rv = sprintf(language_arg, "--language=%s", langdir);
ss_dassert(rv < OPTIONS_LANGUAGE_SIZE); // Ensured by qc_init().
server_options[IDX_LANGUAGE] = language_arg;
// To prevent warning of unused variable when built in release mode,
// when ss_dassert() turns into empty statement.
(void)rv;
}
}
bool qc_init(const char* args)
{
bool inited = false;
if (args)
{
MXS_WARNING("qc_mysqlembedded: '%s' provided as arguments, "
"even though no arguments are supported.", args);
}
if (strlen(get_langdir()) >= PATH_MAX)
{
fprintf(stderr, "MaxScale: error: Language path is too long: %s.", get_langdir());
}
else
{
configure_options(get_process_datadir(), get_langdir());
int argc = N_OPTIONS;
char** argv = const_cast<char**>(server_options);
char** groups = const_cast<char**>(server_groups);
int rc = mysql_library_init(argc, argv, groups);
if (rc != 0)
{
MXS_ERROR("mysql_library_init() failed. Error code: %d", rc);
}
else
{
#if MYSQL_VERSION_ID >= 100000
set_malloc_size_cb(NULL);
#endif
MXS_NOTICE("Query classifier initialized.");
inited = true;
}
}
return inited;
}
void qc_end(void)
{
mysql_library_end();
}
bool qc_thread_init(void)
{
bool inited = (mysql_thread_init() == 0);
if (!inited)
{
MXS_ERROR("mysql_thread_init() failed.");
}
return inited;
}
void qc_thread_end(void)
{
mysql_thread_end();
}
/**
* EXPORTS
*/
extern "C"
{
MXS_MODULE* MXS_CREATE_MODULE()
{
static QUERY_CLASSIFIER qc =
{
qc_init,
qc_end,
qc_thread_init,
qc_thread_end,
qc_parse,
qc_get_type,
qc_get_operation,
qc_get_created_table_name,
qc_is_drop_table_query,
qc_is_real_query,
qc_get_table_names,
NULL,
qc_query_has_clause,
qc_get_database_names,
qc_get_prepare_name,
qc_get_prepare_operation,
qc_get_field_info,
};
static MXS_MODULE info =
{
MXS_MODULE_API_QUERY_CLASSIFIER,
MXS_MODULE_IN_DEVELOPMENT,
QUERY_CLASSIFIER_VERSION,
"Query classifier based upon MySQL Embedded",
"V1.0.0",
&qc
};
return &info;
}
}
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