MaxScale/server/core/modutil.c
VilhoRaatikka fca674b16a modutil.c: added modutil_reply_auth_error
mysql_backend.c:gw_change_user: instead of setting flags directly to replybuffer, set server command to backend's protocol object and reply the message directly to backend where flags are set and it is replied back to client.
2015-01-19 00:01:08 +02:00

674 lines
18 KiB
C

/*
* This file is distributed as part of MaxScale from MariaDB Corporation. 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 2014
*/
/**
* @file modutil.c - Implementation of useful routines for modules
*
* @verbatim
* Revision History
*
* Date Who Description
* 04/06/14 Mark Riddoch Initial implementation
* 24/10/14 Massimiliano Pinto Added modutil_send_mysql_err_packet, modutil_create_mysql_err_msg
*
* @endverbatim
*/
#include <buffer.h>
#include <string.h>
#include <mysql_client_server_protocol.h>
#include <modutil.h>
/** Defined in log_manager.cc */
extern int lm_enabled_logfiles_bitmask;
extern size_t log_ses_count[];
extern __thread log_info_t tls_log_info;
static void modutil_reply_routing_error(
DCB* backend_dcb,
int error,
char* state,
char* errstr,
uint32_t flags);
/**
* 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;
}
/**
* Calculate the length of MySQL packet and how much is missing from the GWBUF
* passed as parameter.
*
* This routine assumes that there is only one MySQL packet in the buffer.
*
* @param buf buffer list including the query, may consist of
* multiple buffers
* @param nbytes_missing pointer to missing bytecount
*
* @return the length of MySQL packet and writes missing bytecount to
* nbytes_missing.
*/
int modutil_MySQL_query_len(
GWBUF* buf,
int* nbytes_missing)
{
int len;
int buflen;
if (!modutil_is_SQL(buf))
{
len = 0;
goto retblock;
}
len = MYSQL_GET_PACKET_LEN((uint8_t *)GWBUF_DATA(buf));
*nbytes_missing = len-1;
buflen = gwbuf_length(buf);
*nbytes_missing -= buflen-5;
retblock:
return len;
}
/**
* 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;
addition->gwbuf_type = orig->gwbuf_type;
orig->next = addition;
}
return orig;
}
/**
* Extract the SQL from a COM_QUERY packet and return in a NULL terminated buffer.
* The buffer should be freed by the caller when it is no longer required.
*
* If the packet is not a COM_QUERY packet then the function will return NULL
*
* @param buf The buffer chain
* @return Null terminated string containing query text or NULL on error
*/
char *
modutil_get_SQL(GWBUF *buf)
{
unsigned int len, length;
unsigned char *ptr, *dptr, *rval = NULL;
if (!modutil_is_SQL(buf))
return rval;
ptr = GWBUF_DATA(buf);
length = *ptr++;
length += (*ptr++ << 8);
length += (*ptr++ << 16);
if ((rval = (char *)malloc(length + 1)) == NULL)
return NULL;
dptr = rval;
ptr += 2; // Skip sequence id and COM_QUERY byte
len = GWBUF_LENGTH(buf) - 5;
while (buf && length > 0)
{
int clen = length > len ? len : length;
memcpy(dptr, ptr, clen);
dptr += clen;
length -= clen;
buf = buf->next;
if (buf)
{
ptr = GWBUF_DATA(buf);
len = GWBUF_LENGTH(buf);
}
}
*dptr = 0;
return rval;
}
/**
* 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 = NULL;
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 (len < 1 || len > ~(size_t)0 - 1 || (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 (len < 1 || len > ~(size_t)0 - 1 || (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;
}
/**
* create a GWBUFF with a MySQL ERR packet
*
* @param packet_number MySQL protocol sequence number in the packet
* @param in_affected_rows MySQL affected rows
* @param mysql_errno The MySQL errno
* @param sqlstate_msg The MySQL State Message
* @param mysql_message The Error Message
* @return The allocated GWBUF or NULL on failure
*/
GWBUF *modutil_create_mysql_err_msg(
int packet_number,
int affected_rows,
int merrno,
const char *statemsg,
const char *msg)
{
uint8_t *outbuf = NULL;
uint32_t mysql_payload_size = 0;
uint8_t mysql_packet_header[4];
uint8_t *mysql_payload = NULL;
uint8_t field_count = 0;
uint8_t mysql_err[2];
uint8_t mysql_statemsg[6];
unsigned int mysql_errno = 0;
const char *mysql_error_msg = NULL;
const char *mysql_state = NULL;
GWBUF *errbuf = NULL;
if (statemsg == NULL || msg == NULL)
{
return NULL;
}
mysql_errno = (unsigned int)merrno;
mysql_error_msg = msg;
mysql_state = statemsg;
field_count = 0xff;
gw_mysql_set_byte2(mysql_err, mysql_errno);
mysql_statemsg[0]='#';
memcpy(mysql_statemsg+1, mysql_state, 5);
mysql_payload_size = sizeof(field_count) +
sizeof(mysql_err) +
sizeof(mysql_statemsg) +
strlen(mysql_error_msg);
/* allocate memory for packet header + payload */
errbuf = gwbuf_alloc(sizeof(mysql_packet_header) + mysql_payload_size);
ss_dassert(errbuf != NULL);
if (errbuf == NULL)
{
return NULL;
}
outbuf = GWBUF_DATA(errbuf);
/** write packet header and packet number */
gw_mysql_set_byte3(mysql_packet_header, mysql_payload_size);
mysql_packet_header[3] = packet_number;
/** write header */
memcpy(outbuf, mysql_packet_header, sizeof(mysql_packet_header));
mysql_payload = outbuf + sizeof(mysql_packet_header);
/** write field */
memcpy(mysql_payload, &field_count, sizeof(field_count));
mysql_payload = mysql_payload + sizeof(field_count);
/** write errno */
memcpy(mysql_payload, mysql_err, sizeof(mysql_err));
mysql_payload = mysql_payload + sizeof(mysql_err);
/** write sqlstate */
memcpy(mysql_payload, mysql_statemsg, sizeof(mysql_statemsg));
mysql_payload = mysql_payload + sizeof(mysql_statemsg);
/** write error message */
memcpy(mysql_payload, mysql_error_msg, strlen(mysql_error_msg));
return errbuf;
}
/**
* modutil_send_mysql_err_packet
*
* Send a MySQL protocol Generic ERR message, to the dcb
*
* @param dcb The DCB to send the packet
* @param packet_number MySQL protocol sequence number in the packet
* @param in_affected_rows MySQL affected rows
* @param mysql_errno The MySQL errno
* @param sqlstate_msg The MySQL State Message
* @param mysql_message The Error Message
* @return 0 for successful dcb write or 1 on failure
*
*/
int modutil_send_mysql_err_packet (
DCB *dcb,
int packet_number,
int in_affected_rows,
int mysql_errno,
const char *sqlstate_msg,
const char *mysql_message)
{
GWBUF* buf;
buf = modutil_create_mysql_err_msg(packet_number, in_affected_rows, mysql_errno, sqlstate_msg, mysql_message);
return dcb->func.write(dcb, buf);
}
/**
* Buffer contains at least one of the following:
* complete [complete] [partial] mysql packet
*
* return pointer to gwbuf containing a complete packet or
* NULL if no complete packet was found.
*/
GWBUF* modutil_get_next_MySQL_packet(
GWBUF** p_readbuf)
{
GWBUF* packetbuf;
GWBUF* readbuf;
size_t buflen;
size_t packetlen;
size_t totalbuflen;
uint8_t* data;
size_t nbytes_copied = 0;
uint8_t* target;
readbuf = *p_readbuf;
if (readbuf == NULL)
{
packetbuf = NULL;
goto return_packetbuf;
}
CHK_GWBUF(readbuf);
if (GWBUF_EMPTY(readbuf))
{
packetbuf = NULL;
goto return_packetbuf;
}
totalbuflen = gwbuf_length(readbuf);
data = (uint8_t *)GWBUF_DATA((readbuf));
packetlen = MYSQL_GET_PACKET_LEN(data)+4;
/** packet is incomplete */
if (packetlen > totalbuflen)
{
packetbuf = NULL;
goto return_packetbuf;
}
packetbuf = gwbuf_alloc(packetlen);
target = GWBUF_DATA(packetbuf);
packetbuf->gwbuf_type = readbuf->gwbuf_type; /*< Copy the type too */
/**
* Copy first MySQL packet to packetbuf and leave posible other
* packets to read buffer.
*/
while (nbytes_copied < packetlen && totalbuflen > 0)
{
uint8_t* src = GWBUF_DATA((*p_readbuf));
size_t bytestocopy;
buflen = GWBUF_LENGTH((*p_readbuf));
bytestocopy = MIN(buflen,packetlen-nbytes_copied);
memcpy(target+nbytes_copied, src, bytestocopy);
*p_readbuf = gwbuf_consume((*p_readbuf), bytestocopy);
totalbuflen = gwbuf_length((*p_readbuf));
nbytes_copied += bytestocopy;
}
ss_dassert(buflen == 0 || nbytes_copied == packetlen);
return_packetbuf:
return packetbuf;
}
/**
* Parse the buffer and split complete packets into individual buffers.
* Any partial packets are left in the old buffer.
* @param p_readbuf Buffer to split
* @return Head of the chain of complete packets
*/
GWBUF* modutil_get_complete_packets(GWBUF** p_readbuf)
{
GWBUF *buff = NULL, *packet = NULL;
while((packet = modutil_get_next_MySQL_packet(p_readbuf)) != NULL)
{
buff = gwbuf_append(buff,packet);
}
return buff;
}
/**
* Count the number of EOF, OK or ERR packets in the buffer. Only complete
* packets are inspected and the buffer is assumed to only contain whole packets.
* If partial packets are in the buffer, they are ingnored. The caller must handle the
* detection of partial packets in buffers.
* @param reply Buffer to use
* @param use_ok Whether the DEPRECATE_EOF flag is set
* @param n_found If there were previous packets found
* @return Number of EOF packets
*/
int
modutil_count_signal_packets(GWBUF *reply, int use_ok, int n_found)
{
unsigned char* ptr = (unsigned char*) reply->start;
unsigned char* end = (unsigned char*) reply->end;
unsigned char* prev = ptr;
int pktlen, eof = 0, err = 0;
int errlen = 0, eoflen = 0;
int iserr = 0, iseof = 0;
while(ptr < end)
{
pktlen = MYSQL_GET_PACKET_LEN(ptr) + 4;
if((iserr = PTR_IS_ERR(ptr)) || (iseof = PTR_IS_EOF(ptr)))
{
if(iserr)
{
err++;
errlen = pktlen;
}
else if(iseof)
{
eof++;
eoflen = pktlen;
}
}
if((ptr + pktlen) > end)
{
ptr = prev;
break;
}
prev = ptr;
ptr += pktlen;
}
/*
* If there were new EOF/ERR packets found, make sure that they are the last
* packet in the buffer.
*/
if((eof || err) && n_found)
{
if(err)
{
ptr -= errlen;
if(!PTR_IS_ERR(ptr))
err = 0;
}
else
{
ptr -= eoflen;
if(!PTR_IS_EOF(ptr))
eof = 0;
}
}
return(eof + err);
}
/**
* Create parse error and EPOLLIN event to event queue of the backend DCB.
* When event is notified the error message is processed as error reply and routed
* upstream to client.
*
* @param backend_dcb DCB where event is added
* @param errstr Plain-text string error
* @param flags GWBUF type flags
*/
void modutil_reply_parse_error(
DCB* backend_dcb,
char* errstr,
uint32_t flags)
{
CHK_DCB(backend_dcb);
modutil_reply_routing_error(backend_dcb, 1064, "42000", errstr, flags);
}
/**
* Create authentication error and EPOLLIN event to event queue of the backend DCB.
* When event is notified the error message is processed as error reply and routed
* upstream to client.
*
* @param backend_dcb DCB where event is added
* @param errstr Plain-text string error
* @param flags GWBUF type flags
*/
void modutil_reply_auth_error(
DCB* backend_dcb,
char* errstr,
uint32_t flags)
{
CHK_DCB(backend_dcb);
modutil_reply_routing_error(backend_dcb, 1045, "28000", errstr, flags);
}
/**
* Create error message and EPOLLIN event to event queue of the backend DCB.
* When event is notified the message is processed as error reply and routed
* upstream to client.
*
* @param backend_dcb DCB where event is added
* @param error SQL error number
* @param state SQL state
* @param errstr Plain-text string error
* @param flags GWBUF type flags
*/
static void modutil_reply_routing_error(
DCB* backend_dcb,
int error,
char* state,
char* errstr,
uint32_t flags)
{
GWBUF* buf;
CHK_DCB(backend_dcb);
buf = modutil_create_mysql_err_msg(1, 0, error, state, errstr);
free(errstr);
if (buf == NULL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Creating routing error message failed.")));
return;
}
/** Set flags that help router to process reply correctly */
gwbuf_set_type(buf, flags);
/** Create an incoming event for backend DCB */
poll_add_epollin_event_to_dcb(backend_dcb, buf);
return;
}