MaxScale/server/modules/protocol/mysql_backend.c
2015-03-23 11:55:03 +02:00

1642 lines
58 KiB
C

/*
* 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 2013-2014
*/
#include "mysql_client_server_protocol.h"
#include <skygw_types.h>
#include <skygw_utils.h>
#include <log_manager.h>
#include <modutil.h>
/*
* MySQL Protocol module for handling the protocol between the gateway
* and the backend MySQL database.
*
* Revision History
* Date Who Description
* 14/06/2013 Mark Riddoch Initial version
* 17/06/2013 Massimiliano Pinto Added MaxScale To Backends routines
* 01/07/2013 Massimiliano Pinto Put Log Manager example code behind SS_DEBUG macros.
* 03/07/2013 Massimiliano Pinto Added delayq for incoming data before mysql connection
* 04/07/2013 Massimiliano Pinto Added asyncrhronous MySQL protocol connection to backend
* 05/07/2013 Massimiliano Pinto Added closeSession if backend auth fails
* 12/07/2013 Massimiliano Pinto Added Mysql Change User via dcb->func.auth()
* 15/07/2013 Massimiliano Pinto Added Mysql session change via dcb->func.session()
* 17/07/2013 Massimiliano Pinto Added dcb->command update from gwbuf->command for proper routing
server replies to client via router->clientReply
* 04/09/2013 Massimiliano Pinto Added dcb->session and dcb->session->client checks for NULL
* 12/09/2013 Massimiliano Pinto Added checks in gw_read_backend_event() for gw_read_backend_handshake
* 27/09/2013 Massimiliano Pinto Changed in gw_read_backend_event the check for dcb_read(), now is if rc < 0
* 24/10/2014 Massimiliano Pinto Added Mysql user@host @db authentication support
* 10/11/2014 Massimiliano Pinto Client charset is passed to backend
*
*/
#include <modinfo.h>
MODULE_INFO info = {
MODULE_API_PROTOCOL,
MODULE_GA,
GWPROTOCOL_VERSION,
"The MySQL to backend server protocol"
};
/** 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 char *version_str = "V2.0.0";
static int gw_create_backend_connection(DCB *backend, SERVER *server, SESSION *in_session);
static int gw_read_backend_event(DCB* dcb);
static int gw_write_backend_event(DCB *dcb);
static int gw_MySQLWrite_backend(DCB *dcb, GWBUF *queue);
static int gw_error_backend_event(DCB *dcb);
static int gw_backend_close(DCB *dcb);
static int gw_backend_hangup(DCB *dcb);
static int backend_write_delayqueue(DCB *dcb);
static void backend_set_delayqueue(DCB *dcb, GWBUF *queue);
static int gw_change_user(DCB *backend_dcb, SERVER *server, SESSION *in_session, GWBUF *queue);
static GWBUF* process_response_data (DCB* dcb, GWBUF* readbuf, int nbytes_to_process);
extern char* create_auth_failed_msg( GWBUF* readbuf, char* hostaddr, uint8_t* sha1);
extern char* create_auth_fail_str(char *username, char *hostaddr, char *sha1, char *db);
static bool sescmd_response_complete(DCB* dcb);
#if defined(NOT_USED)
static int gw_session(DCB *backend_dcb, void *data);
#endif
static MYSQL_session* gw_get_shared_session_auth_info(DCB* dcb);
static GWPROTOCOL MyObject = {
gw_read_backend_event, /* Read - EPOLLIN handler */
gw_MySQLWrite_backend, /* Write - data from gateway */
gw_write_backend_event, /* WriteReady - EPOLLOUT handler */
gw_error_backend_event, /* Error - EPOLLERR handler */
gw_backend_hangup, /* HangUp - EPOLLHUP handler */
NULL, /* Accept */
gw_create_backend_connection, /* Connect */
gw_backend_close, /* Close */
NULL, /* Listen */
gw_change_user, /* Authentication */
NULL /* Session */
};
/*
* Implementation of the mandatory version entry point
*
* @return version string of the module
*/
char *
version()
{
return version_str;
}
/*
* The module initialisation routine, called when the module
* is first loaded.
*/
void
ModuleInit()
{
}
/*
* The module entry point routine. It is this routine that
* must populate the structure that is referred to as the
* "module object", this is a structure with the set of
* external entry points for this module.
*
* @return The module object
*/
GWPROTOCOL *
GetModuleObject()
{
return &MyObject;
}
static MYSQL_session* gw_get_shared_session_auth_info(
DCB* dcb)
{
MYSQL_session* auth_info = NULL;
CHK_DCB(dcb);
CHK_SESSION(dcb->session);
spinlock_acquire(&dcb->session->ses_lock);
if (dcb->session->state != SESSION_STATE_ALLOC) {
auth_info = dcb->session->data;
} else {
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"%lu [gw_get_shared_session_auth_info] Couldn't get "
"session authentication info. Session in a wrong state %d.",
pthread_self(),
dcb->session->state)));
}
spinlock_release(&dcb->session->ses_lock);
return auth_info;
}
/**
* Backend Read Event for EPOLLIN on the MySQL backend protocol module
* @param dcb The backend Descriptor Control Block
* @return 1 on operation, 0 for no action
*/
static int gw_read_backend_event(DCB *dcb) {
MySQLProtocol *client_protocol = NULL;
MySQLProtocol *backend_protocol = NULL;
MYSQL_session *current_session = NULL;
int rc = 0;
CHK_DCB(dcb);
CHK_SESSION(dcb->session);
/*< return only with complete session */
current_session = gw_get_shared_session_auth_info(dcb);
ss_dassert(current_session != NULL);
backend_protocol = (MySQLProtocol *) dcb->protocol;
CHK_PROTOCOL(backend_protocol);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] Read dcb %p fd %d protocol "
"state %d, %s.",
pthread_self(),
dcb,
dcb->fd,
backend_protocol->protocol_auth_state,
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state))));
/* backend is connected:
*
* 1. read server handshake
* 2. if (success) write auth request
* 3. and return
*/
/*<
* If starting to auhenticate with backend server, lock dcb
* to prevent overlapping processing of auth messages.
*/
if (backend_protocol->protocol_auth_state == MYSQL_CONNECTED)
{
spinlock_acquire(&dcb->authlock);
backend_protocol = (MySQLProtocol *) dcb->protocol;
CHK_PROTOCOL(backend_protocol);
if (backend_protocol->protocol_auth_state == MYSQL_CONNECTED)
{
/** Read cached backend handshake */
if (gw_read_backend_handshake(backend_protocol) != 0)
{
backend_protocol->protocol_auth_state = MYSQL_HANDSHAKE_FAILED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] after "
"gw_read_backend_handshake, fd %d, "
"state = MYSQL_HANDSHAKE_FAILED.",
pthread_self(),
backend_protocol->owner_dcb->fd)));
}
else
{
/**
* Decode password and send the auth credentials
* to backend.
*/
if (gw_send_authentication_to_backend(
current_session->db,
current_session->user,
current_session->client_sha1,
backend_protocol) != 0)
{
backend_protocol->protocol_auth_state = MYSQL_AUTH_FAILED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] after "
"gw_send_authentication_to_backend "
"fd %d, state = MYSQL_AUTH_FAILED.",
pthread_self(),
backend_protocol->owner_dcb->fd)));
}
else
{
backend_protocol->protocol_auth_state = MYSQL_AUTH_RECV;
}
}
}
spinlock_release(&dcb->authlock);
} /*< backend_protocol->protocol_auth_state == MYSQL_CONNECTED */
/*
* Now:
* -- check the authentication reply from backend
* OR
* -- handle a previous handshake error
*/
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_RECV ||
backend_protocol->protocol_auth_state == MYSQL_HANDSHAKE_FAILED ||
backend_protocol->protocol_auth_state == MYSQL_AUTH_FAILED)
{
spinlock_acquire(&dcb->authlock);
backend_protocol = (MySQLProtocol *) dcb->protocol;
CHK_PROTOCOL(backend_protocol);
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_RECV ||
backend_protocol->protocol_auth_state == MYSQL_HANDSHAKE_FAILED ||
backend_protocol->protocol_auth_state == MYSQL_AUTH_FAILED)
{
ROUTER_OBJECT *router = NULL;
ROUTER *router_instance = NULL;
void *rsession = NULL;
SESSION *session = dcb->session;
int receive_rc = 0;
CHK_SESSION(session);
if (session == NULL)
{
rc = 0;
goto return_with_lock;
}
router = session->service->router;
router_instance = session->service->router_instance;
rsession = session->router_session;
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_RECV)
{
/**
* Read backend's reply to authentication message
*/
receive_rc =
gw_receive_backend_auth(backend_protocol);
switch (receive_rc) {
case -1:
backend_protocol->protocol_auth_state = MYSQL_AUTH_FAILED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] after "
"gw_receive_backend_authentication "
"fd %d, state = MYSQL_AUTH_FAILED.",
pthread_self(),
backend_protocol->owner_dcb->fd)));
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Backend server didn't "
"accept authentication for user "
"%s.",
current_session->user)));
break;
case 1:
backend_protocol->protocol_auth_state = MYSQL_IDLE;
LOGIF(LD, (skygw_log_write_flush(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"gw_receive_backend_auth succeed. "
"dcb %p fd %d, user %s.",
pthread_self(),
dcb,
dcb->fd,
current_session->user)));
break;
default:
ss_dassert(receive_rc == 0);
LOGIF(LD, (skygw_log_write_flush(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"gw_receive_backend_auth read "
"successfully "
"nothing. dcb %p fd %d, user %s.",
pthread_self(),
dcb,
dcb->fd,
current_session->user)));
rc = 0;
goto return_with_lock;
break;
} /* switch */
}
if (backend_protocol->protocol_auth_state == MYSQL_AUTH_FAILED ||
backend_protocol->protocol_auth_state == MYSQL_HANDSHAKE_FAILED)
{
GWBUF* errbuf;
bool succp;
/**
* protocol state won't change anymore,
* lock can be freed
*/
spinlock_release(&dcb->authlock);
spinlock_acquire(&dcb->delayqlock);
if (dcb->delayq != NULL)
{
while ((dcb->delayq = gwbuf_consume(
dcb->delayq,
GWBUF_LENGTH(dcb->delayq))) != NULL);
}
spinlock_release(&dcb->delayqlock);
/* try reload users' table for next connection */
if (backend_protocol->protocol_auth_state ==
MYSQL_AUTH_FAILED)
{
service_refresh_users(dcb->session->service);
}
#if defined(SS_DEBUG)
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"calling handleError. Backend "
"DCB %p, session %p",
pthread_self(),
dcb,
dcb->session)));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Authentication with backend failed. "
"Session will be closed.");
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_REPLY_CLIENT,
&succp);
gwbuf_free(errbuf);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"after calling handleError. Backend "
"DCB %p, session %p",
pthread_self(),
dcb,
dcb->session)));
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
ss_dassert(dcb->dcb_errhandle_called);
dcb_close(dcb);
rc = 1;
goto return_rc;
}
else
{
ss_dassert(backend_protocol->protocol_auth_state == MYSQL_IDLE);
LOGIF(LD, (skygw_log_write_flush(
LOGFILE_DEBUG,
"%lu [gw_read_backend_event] "
"gw_receive_backend_auth succeed. Fd %d, "
"user %s.",
pthread_self(),
dcb->fd,
current_session->user)));
/* check the delay queue and flush the data */
if (dcb->delayq)
{
rc = backend_write_delayqueue(dcb);
goto return_with_lock;
}
}
} /* MYSQL_AUTH_RECV || MYSQL_AUTH_FAILED */
spinlock_release(&dcb->authlock);
} /* MYSQL_AUTH_RECV || MYSQL_AUTH_FAILED || MYSQL_HANDSHAKE_FAILED */
/* reading MySQL command output from backend and writing to the client */
{
GWBUF *read_buffer = NULL;
ROUTER_OBJECT *router = NULL;
ROUTER *router_instance = NULL;
SESSION *session = dcb->session;
int nbytes_read = 0;
CHK_SESSION(session);
router = session->service->router;
router_instance = session->service->router_instance;
/* read available backend data */
rc = dcb_read(dcb, &read_buffer);
if (rc < 0)
{
GWBUF* errbuf;
bool succp;
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend read error handling #2.")));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Read from backend failed");
router->handleError(
router_instance,
session->router_session,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
gwbuf_free(errbuf);
if (!succp)
{
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
ss_dassert(dcb->dcb_errhandle_called);
dcb_close(dcb);
rc = 0;
goto return_rc;
}
nbytes_read = gwbuf_length(read_buffer);
if (nbytes_read == 0 && dcb->dcb_readqueue == NULL)
{
goto return_rc;
}
else
{
ss_dassert(read_buffer != NULL || dcb->dcb_readqueue != NULL);
}
if(dcb->dcb_readqueue)
{
read_buffer = gwbuf_append(dcb->dcb_readqueue,read_buffer);
}
nbytes_read = gwbuf_length(read_buffer);
if (nbytes_read < 3)
{
dcb->dcb_readqueue = read_buffer;
rc = 0;
goto return_rc;
}
{
GWBUF *tmp = modutil_get_complete_packets(&read_buffer);
if(tmp == NULL)
{
/** No complete packets */
dcb->dcb_readqueue = read_buffer;
rc = 0;
goto return_rc;
}
dcb->dcb_readqueue = read_buffer;
read_buffer = tmp;
}
/**
* If protocol has session command set, concatenate whole
* response into one buffer.
*/
if (protocol_get_srv_command((MySQLProtocol *)dcb->protocol, false) !=
MYSQL_COM_UNDEFINED)
{
read_buffer = process_response_data(dcb, read_buffer, nbytes_read);
/**
* Received incomplete response to session command.
* Store it to readqueue and return.
*/
if (!sescmd_response_complete(dcb))
{
rc = 0;
goto return_rc;
}
}
/**
* Check that session is operable, and that client DCB is
* still listening the socket for replies.
*/
if (dcb->session->state == SESSION_STATE_ROUTER_READY &&
dcb->session->client != NULL &&
dcb->session->client->state == DCB_STATE_POLLING)
{
client_protocol = SESSION_PROTOCOL(dcb->session,
MySQLProtocol);
if (client_protocol != NULL)
{
CHK_PROTOCOL(client_protocol);
if (client_protocol->protocol_auth_state ==
MYSQL_IDLE)
{
gwbuf_set_type(read_buffer, GWBUF_TYPE_MYSQL);
router->clientReply(
router_instance,
session->router_session,
read_buffer,
dcb);
rc = 1;
}
goto return_rc;
}
else if (dcb->session->client->dcb_role == DCB_ROLE_INTERNAL)
{
gwbuf_set_type(read_buffer, GWBUF_TYPE_MYSQL);
router->clientReply(router_instance, session->router_session, read_buffer, dcb);
rc = 1;
}
}
else /*< session is closing; replying to client isn't possible */
{
gwbuf_free(read_buffer);
}
}
return_rc:
return rc;
return_with_lock:
spinlock_release(&dcb->authlock);
goto return_rc;
}
/*
* EPOLLOUT handler for the MySQL Backend protocol module.
*
* @param dcb The descriptor control block
* @return 1 in success, 0 in case of failure,
*/
static int gw_write_backend_event(DCB *dcb) {
int rc = 0;
MySQLProtocol *backend_protocol = dcb->protocol;
/*<
* Don't write to backend if backend_dcb is not in poll set anymore.
*/
if (dcb->state != DCB_STATE_POLLING) {
uint8_t* data;
if (dcb->writeq != NULL)
{
data = (uint8_t *)GWBUF_DATA(dcb->writeq);
if(dcb->session->client == NULL)
{
rc = 0;
}
else if (!(MYSQL_IS_COM_QUIT(data)))
{
/*< vraa : errorHandle */
mysql_send_custom_error(
dcb->session->client,
1,
0,
"Writing to backend failed due invalid Maxscale "
"state.");
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_write_backend_event] Write to backend "
"dcb %p fd %d "
"failed due invalid state %s.",
pthread_self(),
dcb,
dcb->fd,
STRDCBSTATE(dcb->state))));
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Attempt to write buffered data to backend "
"failed "
"due internal inconsistent state.")));
rc = 0;
}
}
else
{
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_write_backend_event] Dcb %p in state %s "
"but there's nothing to write either.",
pthread_self(),
dcb,
STRDCBSTATE(dcb->state))));
rc = 1;
}
goto return_rc;
}
if (backend_protocol->protocol_auth_state == MYSQL_PENDING_CONNECT) {
backend_protocol->protocol_auth_state = MYSQL_CONNECTED;
rc = 1;
goto return_rc;
}
dcb_drain_writeq(dcb);
rc = 1;
return_rc:
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_write_backend_event] "
"wrote to dcb %p fd %d, return %d",
pthread_self(),
dcb,
dcb->fd,
rc)));
return rc;
}
/*
* Write function for backend DCB. Store command to protocol.
*
* @param dcb The DCB of the backend
* @param queue Queue of buffers to write
* @return 0 on failure, 1 on success
*/
static int
gw_MySQLWrite_backend(DCB *dcb, GWBUF *queue)
{
MySQLProtocol *backend_protocol = dcb->protocol;
int rc = 0;
spinlock_acquire(&dcb->authlock);
/**
* Pick action according to state of protocol.
* If auth failed, return value is 0, write and buffered write
* return 1.
*/
switch (backend_protocol->protocol_auth_state) {
case MYSQL_HANDSHAKE_FAILED:
case MYSQL_AUTH_FAILED:
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Unable to write to backend due to "
"authentication failure.")));
/** Consume query buffer */
while ((queue = gwbuf_consume(
queue,
GWBUF_LENGTH(queue))) != NULL);
rc = 0;
spinlock_release(&dcb->authlock);
goto return_rc;
break;
case MYSQL_IDLE:
{
uint8_t* ptr = GWBUF_DATA(queue);
int cmd = MYSQL_GET_COMMAND(ptr);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_MySQLWrite_backend] write to dcb %p "
"fd %d protocol state %s.",
pthread_self(),
dcb,
dcb->fd,
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state))));
spinlock_release(&dcb->authlock);
/**
* Statement type is used in readwrite split router.
* Command is *not* set for readconn router.
*
* Server commands are stored to MySQLProtocol structure
* if buffer always includes a single statement.
*/
if (GWBUF_IS_TYPE_SINGLE_STMT(queue) &&
GWBUF_IS_TYPE_SESCMD(queue))
{
/** Record the command to backend's protocol */
protocol_add_srv_command(backend_protocol, cmd);
}
/** Write to backend */
rc = dcb_write(dcb, queue);
goto return_rc;
break;
}
default:
{
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_MySQLWrite_backend] delayed write to "
"dcb %p fd %d protocol state %s.",
pthread_self(),
dcb,
dcb->fd,
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state))));
/**
* In case of session commands, store command to DCB's
* protocol struct.
*/
if (GWBUF_IS_TYPE_SINGLE_STMT(queue) &&
GWBUF_IS_TYPE_SESCMD(queue))
{
uint8_t* ptr = GWBUF_DATA(queue);
int cmd = MYSQL_GET_COMMAND(ptr);
/** Record the command to backend's protocol */
protocol_add_srv_command(backend_protocol, cmd);
}
/*<
* Now put the incoming data to the delay queue unless backend is
* connected with auth ok
*/
backend_set_delayqueue(dcb, queue);
spinlock_release(&dcb->authlock);
rc = 1;
goto return_rc;
break;
}
}
return_rc:
return rc;
}
/**
* Error event handler.
* Create error message, pass it to router's error handler and if error
* handler fails in providing enough backend servers, mark session being
* closed and call DCB close function which triggers closing router session
* and related backends (if any exists.
*/
static int gw_error_backend_event(DCB *dcb)
{
SESSION* session;
void* rsession;
ROUTER_OBJECT* router;
ROUTER* router_instance;
GWBUF* errbuf;
bool succp;
session_state_t ses_state;
CHK_DCB(dcb);
session = dcb->session;
CHK_SESSION(session);
rsession = session->router_session;
router = session->service->router;
router_instance = session->service->router_instance;
/**
* Avoid running redundant error handling procedure.
* dcb_close is already called for the DCB. Thus, either connection is
* closed by router and COM_QUIT sent or there was an error which
* have already been handled.
*/
if (dcb->state != DCB_STATE_POLLING)
{
int error, len;
char buf[100];
len = sizeof(error);
if (getsockopt(dcb->fd, SOL_SOCKET, SO_ERROR, &error, (socklen_t *)&len) == 0)
{
if (error != 0)
{
strerror_r(error, buf, 100);
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"DCB in state %s got error '%s'.",
STRDCBSTATE(dcb->state),
buf)));
}
}
return 1;
}
errbuf = mysql_create_custom_error(
1,
0,
"Lost connection to backend server.");
spinlock_acquire(&session->ses_lock);
ses_state = session->state;
spinlock_release(&session->ses_lock);
/**
* Session might be initialized when DCB already is in the poll set.
* Thus hangup can occur in the middle of session initialization.
* Only complete and successfully initialized sessions allow for
* calling error handler.
*/
while (ses_state == SESSION_STATE_READY)
{
spinlock_acquire(&session->ses_lock);
ses_state = session->state;
spinlock_release(&session->ses_lock);
}
if (ses_state != SESSION_STATE_ROUTER_READY)
{
int error, len;
char buf[100];
len = sizeof(error);
if (getsockopt(dcb->fd, SOL_SOCKET, SO_ERROR, &error, (socklen_t *)&len) == 0)
{
if (error != 0)
{
strerror_r(error, buf, 100);
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error '%s' in session that is not ready for routing.",
buf)));
}
}
gwbuf_free(errbuf);
goto retblock;
}
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend error event handling.")));
#endif
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
gwbuf_free(errbuf);
/**
* If error handler fails it means that routing session can't continue
* and it must be closed. In success, only this DCB is closed.
*/
if (!succp)
{
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
ss_dassert(dcb->dcb_errhandle_called);
dcb_close(dcb);
retblock:
return 1;
}
/*
* Create a new backend connection.
*
* This routine will connect to a backend server and it is called by dbc_connect
* in router->newSession
*
* @param backend_dcb, in, out, use - backend DCB allocated from dcb_connect
* @param server, in, use - server to connect to
* @param session, in use - current session from client DCB
* @return 0/1 on Success and -1 on Failure.
* If succesful, returns positive fd to socket which is connected to
* backend server. Positive fd is copied to protocol and to dcb.
* If fails, fd == -1 and socket is closed.
*/
static int gw_create_backend_connection(
DCB *backend_dcb,
SERVER *server,
SESSION *session)
{
MySQLProtocol *protocol = NULL;
int rv = -1;
int fd = -1;
protocol = mysql_protocol_init(backend_dcb, -1);
ss_dassert(protocol != NULL);
if (protocol == NULL) {
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Failed to create "
"protocol object for backend connection.",
pthread_self())));
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error: Failed to create "
"protocol object for backend connection.")));
goto return_fd;
}
/** Copy client flags to backend protocol */
if (backend_dcb->session->client->protocol)
{
/** Copy client flags to backend protocol */
protocol->client_capabilities =
((MySQLProtocol *)(backend_dcb->session->client->protocol))->client_capabilities;
/** Copy client charset to backend protocol */
protocol->charset =
((MySQLProtocol *)(backend_dcb->session->client->protocol))->charset;
}
else
{
protocol->client_capabilities = GW_MYSQL_CAPABILITIES_CLIENT;
protocol->charset = 0x08;
}
/*< if succeed, fd > 0, -1 otherwise */
rv = gw_do_connect_to_backend(server->name, server->port, &fd);
/*< Assign protocol with backend_dcb */
backend_dcb->protocol = protocol;
/*< Set protocol state */
switch (rv) {
case 0:
ss_dassert(fd > 0);
protocol->fd = fd;
protocol->protocol_auth_state = MYSQL_CONNECTED;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Established "
"connection to %s:%i, protocol fd %d client "
"fd %d.",
pthread_self(),
server->name,
server->port,
protocol->fd,
session->client->fd)));
break;
case 1:
ss_dassert(fd > 0);
protocol->protocol_auth_state = MYSQL_PENDING_CONNECT;
protocol->fd = fd;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Connection "
"pending to %s:%i, protocol fd %d client fd %d.",
pthread_self(),
server->name,
server->port,
protocol->fd,
session->client->fd)));
break;
default:
ss_dassert(fd == -1);
ss_dassert(protocol->protocol_auth_state == MYSQL_ALLOC);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [gw_create_backend_connection] Connection "
"failed to %s:%i, protocol fd %d client fd %d.",
pthread_self(),
server->name,
server->port,
protocol->fd,
session->client->fd)));
break;
} /*< switch */
return_fd:
return fd;
}
/**
* Error event handler.
* Create error message, pass it to router's error handler and if error
* handler fails in providing enough backend servers, mark session being
* closed and call DCB close function which triggers closing router session
* and related backends (if any exists.
*
* @param dcb The current Backend DCB
* @return 1 always
*/
static int
gw_backend_hangup(DCB *dcb)
{
SESSION* session;
void* rsession;
ROUTER_OBJECT* router;
ROUTER* router_instance;
bool succp;
GWBUF* errbuf;
session_state_t ses_state;
CHK_DCB(dcb);
session = dcb->session;
CHK_SESSION(session);
rsession = session->router_session;
router = session->service->router;
router_instance = session->service->router_instance;
errbuf = mysql_create_custom_error(
1,
0,
"Lost connection to backend server.");
spinlock_acquire(&session->ses_lock);
ses_state = session->state;
spinlock_release(&session->ses_lock);
/**
* Session might be initialized when DCB already is in the poll set.
* Thus hangup can occur in the middle of session initialization.
* Only complete and successfully initialized sessions allow for
* calling error handler.
*/
while (ses_state == SESSION_STATE_READY)
{
spinlock_acquire(&session->ses_lock);
ses_state = session->state;
spinlock_release(&session->ses_lock);
}
if (ses_state != SESSION_STATE_ROUTER_READY)
{
int error, len;
char buf[100];
len = sizeof(error);
if (getsockopt(dcb->fd, SOL_SOCKET, SO_ERROR, &error, (socklen_t *)&len) == 0)
{
if (error != 0)
{
strerror_r(error, buf, 100);
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Hangup in session that is not ready for routing, "
"Error reported is '%s'.",
buf)));
}
}
gwbuf_free(errbuf);
goto retblock;
}
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend hangup error handling.")));
#endif
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
gwbuf_free(errbuf);
/** There are no required backends available, close session. */
if (!succp)
{
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend hangup -> closing session.")));
#endif
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
}
ss_dassert(dcb->dcb_errhandle_called);
dcb_close(dcb);
retblock:
return 1;
}
/**
* Send COM_QUIT to backend so that it can be closed.
* @param dcb The current Backend DCB
* @return 1 always
*/
static int
gw_backend_close(DCB *dcb)
{
DCB* client_dcb;
SESSION* session;
GWBUF* quitbuf;
CHK_DCB(dcb);
session = dcb->session;
CHK_SESSION(session);
LOGIF(LD, (skygw_log_write(LOGFILE_DEBUG,
"%lu [gw_backend_close]",
pthread_self())));
quitbuf = mysql_create_com_quit(NULL, 0);
gwbuf_set_type(quitbuf, GWBUF_TYPE_MYSQL);
/** Send COM_QUIT to the backend being closed */
mysql_send_com_quit(dcb, 0, quitbuf);
mysql_protocol_done(dcb);
/**
* The lock is needed only to protect the read of session->state and
* session->client values. Client's state may change by other thread
* but client's close and adding client's DCB to zombies list is executed
* only if client's DCB's state does _not_ change in parallel.
*/
spinlock_acquire(&session->ses_lock);
/**
* If session->state is STOPPING, start closing client session.
* Otherwise only this backend connection is closed.
*/
if (session != NULL &&
session->state == SESSION_STATE_STOPPING &&
session->client != NULL)
{
if (session->client->state == DCB_STATE_POLLING)
{
spinlock_release(&session->ses_lock);
/** Close client DCB */
dcb_close(session->client);
}
else
{
spinlock_release(&session->ses_lock);
}
}
else
{
spinlock_release(&session->ses_lock);
}
return 1;
}
/**
* This routine put into the delay queue the input queue
* The input is what backend DCB is receiving
* The routine is called from func.write() when mysql backend connection
* is not yet complete buu there are inout data from client
*
* @param dcb The current backend DCB
* @param queue Input data in the GWBUF struct
*/
static void backend_set_delayqueue(DCB *dcb, GWBUF *queue) {
spinlock_acquire(&dcb->delayqlock);
if (dcb->delayq) {
/* Append data */
dcb->delayq = gwbuf_append(dcb->delayq, queue);
} else {
if (queue != NULL) {
/* create the delay queue */
dcb->delayq = queue;
}
}
spinlock_release(&dcb->delayqlock);
}
/**
* This routine writes the delayq via dcb_write
* The dcb->delayq contains data received from the client before
* mysql backend authentication succeded
*
* @param dcb The current backend DCB
* @return The dcb_write status
*/
static int backend_write_delayqueue(DCB *dcb)
{
GWBUF *localq = NULL;
int rc;
spinlock_acquire(&dcb->delayqlock);
if (dcb->delayq == NULL)
{
spinlock_release(&dcb->delayqlock);
rc = 1;
}
else
{
localq = dcb->delayq;
dcb->delayq = NULL;
spinlock_release(&dcb->delayqlock);
if (MYSQL_IS_CHANGE_USER(((uint8_t *)GWBUF_DATA(localq))))
{
MYSQL_session* mses;
GWBUF* new_packet;
mses = (MYSQL_session *)dcb->session->client->data;
new_packet = gw_create_change_user_packet(
mses,
(MySQLProtocol *)dcb->protocol);
/**
* Remove previous packet which lacks scramble
* and append the new.
*/
localq = gwbuf_consume(localq, GWBUF_LENGTH(localq));
localq = gwbuf_append(localq, new_packet);
}
rc = dcb_write(dcb, localq);
}
if (rc == 0)
{
GWBUF* errbuf;
bool succp;
ROUTER_OBJECT *router = NULL;
ROUTER *router_instance = NULL;
void *rsession = NULL;
SESSION *session = dcb->session;
CHK_SESSION(session);
if (session != NULL)
{
router = session->service->router;
router_instance = session->service->router_instance;
rsession = session->router_session;
#if defined(SS_DEBUG)
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Backend write delayqueue error handling.")));
#endif
errbuf = mysql_create_custom_error(
1,
0,
"Failed to write buffered data to back-end server. "
"Buffer was empty or back-end was disconnected during "
"operation. Attempting to find a new backend.");
router->handleError(router_instance,
rsession,
errbuf,
dcb,
ERRACT_NEW_CONNECTION,
&succp);
gwbuf_free(errbuf);
if (!succp)
{
spinlock_acquire(&session->ses_lock);
session->state = SESSION_STATE_STOPPING;
spinlock_release(&session->ses_lock);
ss_dassert(dcb->dcb_errhandle_called);
dcb_close(dcb);
}
}
}
return rc;
}
/**
* This routine handles the COM_CHANGE_USER command
*
* @param dcb The current backend DCB
* @param server The backend server pointer
* @param in_session The current session data (MYSQL_session)
* @param queue The GWBUF containing the COM_CHANGE_USER receveid
* @return 1 on success and 0 on failure
*/
static int gw_change_user(
DCB *backend,
SERVER *server,
SESSION *in_session,
GWBUF *queue)
{
MYSQL_session *current_session = NULL;
MySQLProtocol *backend_protocol = NULL;
MySQLProtocol *client_protocol = NULL;
char username[MYSQL_USER_MAXLEN+1]="";
char database[MYSQL_DATABASE_MAXLEN+1]="";
char current_database[MYSQL_DATABASE_MAXLEN+1]="";
uint8_t client_sha1[MYSQL_SCRAMBLE_LEN]="";
uint8_t *client_auth_packet = GWBUF_DATA(queue);
unsigned int auth_token_len = 0;
uint8_t *auth_token = NULL;
int rv = -1;
int auth_ret = 1;
current_session = (MYSQL_session *)in_session->client->data;
backend_protocol = backend->protocol;
client_protocol = in_session->client->protocol;
/* now get the user, after 4 bytes header and 1 byte command */
client_auth_packet += 5;
strncpy(username, (char *)client_auth_packet,MYSQL_USER_MAXLEN);
client_auth_packet += strlen(username) + 1;
/* get the auth token len */
memcpy(&auth_token_len, client_auth_packet, 1);
client_auth_packet++;
/* allocate memory for token only if auth_token_len > 0 */
if (auth_token_len > 0) {
auth_token = (uint8_t *)malloc(auth_token_len);
ss_dassert(auth_token != NULL);
if (auth_token == NULL)
return rv;
memcpy(auth_token, client_auth_packet, auth_token_len);
client_auth_packet += auth_token_len;
}
/* get new database name */
strncpy(database, (char *)client_auth_packet,MYSQL_DATABASE_MAXLEN);
/* get character set */
if (strlen(database)) {
client_auth_packet += strlen(database) + 1;
} else {
client_auth_packet++;
}
if (client_auth_packet && *client_auth_packet)
memcpy(&backend_protocol->charset, client_auth_packet, sizeof(int));
/* save current_database name */
strncpy(current_database, current_session->db,MYSQL_DATABASE_MAXLEN);
/*
* Now clear database name in dcb as we don't do local authentication on db name for change user.
* Local authentication only for user@host and if successful the database name change is sent to backend.
*/
strcpy(current_session->db, "");
/*
* decode the token and check the password.
* Note: if auth_token_len == 0 && auth_token == NULL, user is without password
*/
auth_ret = gw_check_mysql_scramble_data(backend->session->client,
auth_token,
auth_token_len,
client_protocol->scramble,
sizeof(client_protocol->scramble),
username,
client_sha1);
if (auth_ret != 0) {
if (!service_refresh_users(backend->session->client->service)) {
/* Try authentication again with new repository data */
/* Note: if no auth client authentication will fail */
auth_ret = gw_check_mysql_scramble_data(
backend->session->client,
auth_token, auth_token_len,
client_protocol->scramble,
sizeof(client_protocol->scramble),
username,
client_sha1);
}
}
/* copy back current datbase to client session */
strcpy(current_session->db, current_database);
/* let's free the auth_token now */
if (auth_token)
free(auth_token);
if (auth_ret != 0) {
char *password_set = NULL;
char *message = NULL;
GWBUF* buf;
if (auth_token_len > 0)
password_set = (char *)client_sha1;
else
password_set = "";
/**
* Create an error message and make it look like legit reply
* from backend server. Then make it look like an incoming event
* so that thread gets new task of it, calls clientReply
* which filters out duplicate errors from same cause and forward
* reply to the client.
*/
message = create_auth_fail_str(username,
backend->session->client->remote,
password_set,
"");
if (message == NULL)
{
LOGIF(LE, (skygw_log_write_flush(
LOGFILE_ERROR,
"Error : Creating error message failed.")));
rv = 0;
goto retblock;
}
/**
* Add command to backend's protocol, create artificial reply
* packet and add it to client's read buffer.
*/
protocol_add_srv_command((MySQLProtocol*)backend->protocol,
MYSQL_COM_CHANGE_USER);
modutil_reply_auth_error(backend, message, 0);
rv = 1;
} else {
rv = gw_send_change_user_to_backend(database, username, client_sha1, backend_protocol);
/*
* Now copy new data into user session
*/
strcpy(current_session->user, username);
strcpy(current_session->db, database);
memcpy(current_session->client_sha1, client_sha1, sizeof(current_session->client_sha1));
}
retblock:
gwbuf_free(queue);
return rv;
}
/**
* Move packets or parts of packets from readbuf to outbuf as the packet headers
* and lengths have been noticed and counted.
* Session commands need to be marked so that they can be handled properly in
* the router's clientReply.
*
* @param dcb Backend's DCB where data was read from
* @param readbuf GWBUF where data was read to
* @param nbytes_to_process Number of bytes that has been read and need to be processed
*
* @return GWBUF which includes complete MySQL packet
*/
static GWBUF* process_response_data (
DCB* dcb,
GWBUF* readbuf,
int nbytes_to_process)
{
int npackets_left = 0; /*< response's packet count */
ssize_t nbytes_left = 0; /*< nbytes to be read for the packet */
MySQLProtocol* p;
GWBUF* outbuf = NULL;
/** Get command which was stored in gw_MySQLWrite_backend */
p = DCB_PROTOCOL(dcb, MySQLProtocol);
if (!DCB_IS_CLONE(dcb)) CHK_PROTOCOL(p);
/** All buffers processed here are sescmd responses */
gwbuf_set_type(readbuf, GWBUF_TYPE_SESCMD_RESPONSE);
/**
* Now it is known how many packets there should be and how much
* is read earlier.
*/
while (nbytes_to_process != 0)
{
mysql_server_cmd_t srvcmd;
bool succp;
srvcmd = protocol_get_srv_command(p, false);
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [process_response_data] Read command %s for DCB %p fd %d.",
pthread_self(),
STRPACKETTYPE(srvcmd),
dcb,
dcb->fd)));
/**
* Read values from protocol structure, fails if values are
* uninitialized.
*/
if (npackets_left == 0)
{
succp = protocol_get_response_status(p, &npackets_left, &nbytes_left);
if (!succp || npackets_left == 0)
{
/**
* Examine command type and the readbuf. Conclude response
* packet count from the command type or from the first
* packet content. Fails if read buffer doesn't include
* enough data to read the packet length.
*/
init_response_status(readbuf, srvcmd, &npackets_left, &nbytes_left);
}
}
/** Only session commands with responses should be processed */
ss_dassert(npackets_left > 0);
/** Read incomplete packet. */
if (nbytes_left > nbytes_to_process)
{
/** Includes length info so it can be processed */
if (nbytes_to_process >= 5)
{
/** discard source buffer */
readbuf = gwbuf_consume(readbuf, GWBUF_LENGTH(readbuf));
nbytes_left -= nbytes_to_process;
}
nbytes_to_process = 0;
}
/** Packet was read. All bytes belonged to the last packet. */
else if (nbytes_left == nbytes_to_process)
{
nbytes_left = 0;
nbytes_to_process = 0;
ss_dassert(npackets_left > 0);
npackets_left -= 1;
outbuf = gwbuf_append(outbuf, readbuf);
readbuf = NULL;
}
/**
* Packet was read. There should be more since bytes were
* left over.
* Move the next packet to its own buffer and add that next
* to the prev packet's buffer.
*/
else /*< nbytes_left < nbytes_to_process */
{
ss_dassert(nbytes_left >= 0);
nbytes_to_process -= nbytes_left;
/** Move the prefix of the buffer to outbuf from redbuf */
outbuf = gwbuf_append(outbuf,
gwbuf_clone_portion(readbuf, 0, (size_t)nbytes_left));
readbuf = gwbuf_consume(readbuf, (size_t)nbytes_left);
ss_dassert(npackets_left > 0);
npackets_left -= 1;
nbytes_left = 0;
}
/** Store new status to protocol structure */
protocol_set_response_status(p, npackets_left, nbytes_left);
/** A complete packet was read */
if (nbytes_left == 0)
{
/** No more packets in this response */
if (npackets_left == 0 && outbuf != NULL)
{
GWBUF* b = outbuf;
while (b->next != NULL)
{
b = b->next;
}
/** Mark last as end of response */
gwbuf_set_type(b, GWBUF_TYPE_RESPONSE_END);
/** Archive the command */
protocol_archive_srv_command(p);
}
/** Read next packet */
else
{
uint8_t* data;
/** Read next packet length */
data = GWBUF_DATA(readbuf);
nbytes_left = MYSQL_GET_PACKET_LEN(data)+MYSQL_HEADER_LEN;
/** Store new status to protocol structure */
protocol_set_response_status(p, npackets_left, nbytes_left);
}
}
}
return outbuf;
}
static bool sescmd_response_complete(
DCB* dcb)
{
int npackets_left;
ssize_t nbytes_left;
MySQLProtocol* p;
bool succp;
p = DCB_PROTOCOL(dcb, MySQLProtocol);
if (!DCB_IS_CLONE(dcb)) CHK_PROTOCOL(p);
protocol_get_response_status(p, &npackets_left, &nbytes_left);
if (npackets_left == 0)
{
succp = true;
}
else
{
succp = false;
}
return succp;
}