229 lines
6.5 KiB
C
229 lines
6.5 KiB
C
/*
|
|
* This file is distributed as part of MaxScale from SkySQL. 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 SkySQL Ab 2014
|
|
*/
|
|
|
|
/**
|
|
* @file modutil.c - Implementation of useful routines for modules
|
|
*
|
|
* @verbatim
|
|
* Revision History
|
|
*
|
|
* Date Who Description
|
|
* 04/06/14 Mark Riddoch Initial implementation
|
|
*
|
|
* @endverbatim
|
|
*/
|
|
#include <buffer.h>
|
|
#include <string.h>
|
|
#include <mysql_client_server_protocol.h>
|
|
|
|
/**
|
|
* Check if a GWBUF structure is a MySQL COM_QUERY packet
|
|
*
|
|
* @param buf Buffer to check
|
|
* @return True if GWBUF is a COM_QUERY packet
|
|
*/
|
|
int
|
|
modutil_is_SQL(GWBUF *buf)
|
|
{
|
|
unsigned char *ptr;
|
|
|
|
if (GWBUF_LENGTH(buf) < 5)
|
|
return 0;
|
|
ptr = GWBUF_DATA(buf);
|
|
return ptr[4] == 0x03; // COM_QUERY
|
|
}
|
|
|
|
/**
|
|
* Extract the SQL portion of a COM_QUERY packet
|
|
*
|
|
* NB This sets *sql to point into the packet and does not
|
|
* allocate any new storage. The string pointed to by *sql is
|
|
* not NULL terminated.
|
|
*
|
|
* This routine is very simplistic and does not deal with SQL text
|
|
* that spans multiple buffers.
|
|
*
|
|
* The length returned is the complete length of the SQL, which may
|
|
* be larger than the amount of data in this packet.
|
|
*
|
|
* @param buf The packet buffer
|
|
* @param sql Pointer that is set to point at the SQL data
|
|
* @param length Length of the SQL query data
|
|
* @return True if the packet is a COM_QUERY packet
|
|
*/
|
|
int
|
|
modutil_extract_SQL(GWBUF *buf, char **sql, int *length)
|
|
{
|
|
unsigned char *ptr;
|
|
|
|
if (!modutil_is_SQL(buf))
|
|
return 0;
|
|
ptr = GWBUF_DATA(buf);
|
|
*length = *ptr++;
|
|
*length += (*ptr++ << 8);
|
|
*length += (*ptr++ << 16);
|
|
ptr += 2; // Skip sequence id and COM_QUERY byte
|
|
*length = *length - 1;
|
|
*sql = (char *)ptr;
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* Extract the SQL portion of a COM_QUERY packet
|
|
*
|
|
* NB This sets *sql to point into the packet and does not
|
|
* allocate any new storage. The string pointed to by *sql is
|
|
* not NULL terminated.
|
|
*
|
|
* The number of bytes pointed to *sql is returned in *length
|
|
*
|
|
* The remaining number of bytes required for the complete query string
|
|
* are returned in *residual
|
|
*
|
|
* @param buf The packet buffer
|
|
* @param sql Pointer that is set to point at the SQL data
|
|
* @param length Length of the SQL query data pointed to by sql
|
|
* @param residual Any remain part of the query in future packets
|
|
* @return True if the packet is a COM_QUERY packet
|
|
*/
|
|
int
|
|
modutil_MySQL_Query(GWBUF *buf, char **sql, int *length, int *residual)
|
|
{
|
|
unsigned char *ptr;
|
|
|
|
if (!modutil_is_SQL(buf))
|
|
return 0;
|
|
ptr = GWBUF_DATA(buf);
|
|
*residual = *ptr++;
|
|
*residual += (*ptr++ << 8);
|
|
*residual += (*ptr++ << 16);
|
|
ptr += 2; // Skip sequence id and COM_QUERY byte
|
|
*residual = *residual - 1;
|
|
*length = GWBUF_LENGTH(buf) - 5;
|
|
*residual -= *length;
|
|
*sql = (char *)ptr;
|
|
return 1;
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* Replace the contents of a GWBUF with the new SQL statement passed as a text string.
|
|
* The routine takes care of the modification needed to the MySQL packet,
|
|
* returning a GWBUF chain that can be used to send the data to a MySQL server
|
|
*
|
|
* @param orig The original request in a GWBUF
|
|
* @param sql The SQL text to replace in the packet
|
|
* @return A newly formed GWBUF containing the MySQL packet.
|
|
*/
|
|
GWBUF *
|
|
modutil_replace_SQL(GWBUF *orig, char *sql)
|
|
{
|
|
unsigned char *ptr;
|
|
int length, newlength;
|
|
GWBUF *addition;
|
|
|
|
if (!modutil_is_SQL(orig))
|
|
return NULL;
|
|
ptr = GWBUF_DATA(orig);
|
|
length = *ptr++;
|
|
length += (*ptr++ << 8);
|
|
length += (*ptr++ << 16);
|
|
ptr += 2; // Skip sequence id and COM_QUERY byte
|
|
|
|
newlength = strlen(sql);
|
|
if (length - 1 == newlength)
|
|
{
|
|
/* New SQL is the same length as old */
|
|
memcpy(ptr, sql, newlength);
|
|
}
|
|
else if (length - 1 > newlength)
|
|
{
|
|
/* New SQL is shorter */
|
|
memcpy(ptr, sql, newlength);
|
|
GWBUF_RTRIM(orig, (length - 1) - newlength);
|
|
}
|
|
else
|
|
{
|
|
memcpy(ptr, sql, length - 1);
|
|
addition = gwbuf_alloc(newlength - (length - 1));
|
|
memcpy(GWBUF_DATA(addition), &sql[length - 1], newlength - (length - 1));
|
|
ptr = GWBUF_DATA(orig);
|
|
*ptr++ = (newlength + 1) & 0xff;
|
|
*ptr++ = ((newlength + 1) >> 8) & 0xff;
|
|
*ptr++ = ((newlength + 1) >> 16) & 0xff;
|
|
orig->next = addition;
|
|
}
|
|
|
|
return orig;
|
|
}
|
|
|
|
/**
|
|
* Copy query string from GWBUF buffer to separate memory area.
|
|
*
|
|
* @param buf GWBUF buffer including the query
|
|
*
|
|
* @return Plain text query if the packet type is COM_QUERY. Otherwise return
|
|
* a string including the packet type.
|
|
*/
|
|
char *
|
|
modutil_get_query(GWBUF *buf)
|
|
{
|
|
uint8_t* packet;
|
|
mysql_server_cmd_t packet_type;
|
|
size_t len;
|
|
char* query_str;
|
|
|
|
packet = GWBUF_DATA(buf);
|
|
packet_type = packet[4];
|
|
|
|
switch (packet_type) {
|
|
case MYSQL_COM_QUIT:
|
|
len = strlen("[Quit msg]")+1;
|
|
if ((query_str = (char *)malloc(len+1)) == NULL)
|
|
{
|
|
goto retblock;
|
|
}
|
|
memcpy(query_str, "[Quit msg]", len);
|
|
memset(&query_str[len], 0, 1);
|
|
break;
|
|
|
|
case MYSQL_COM_QUERY:
|
|
len = MYSQL_GET_PACKET_LEN(packet)-1; /*< distract 1 for packet type byte */
|
|
if ((query_str = (char *)malloc(len+1)) == NULL)
|
|
{
|
|
goto retblock;
|
|
}
|
|
memcpy(query_str, &packet[5], len);
|
|
memset(&query_str[len], 0, 1);
|
|
break;
|
|
|
|
default:
|
|
len = strlen(STRPACKETTYPE(packet_type))+1;
|
|
if ((query_str = (char *)malloc(len+1)) == NULL)
|
|
{
|
|
goto retblock;
|
|
}
|
|
memcpy(query_str, STRPACKETTYPE(packet_type), len);
|
|
memset(&query_str[len], 0, 1);
|
|
break;
|
|
} /*< switch */
|
|
retblock:
|
|
return query_str;
|
|
}
|