/**
* Reset the session's internal counters.
* @param my_session Tee session
* @param buffer Buffer with the query of the main branch in it
* @return 1 on success, 0 on error
*/
int reset_session_state(TEE_SESSION* my_session, GWBUF* buffer)
{
if (gwbuf_length(buffer) < 5)
{
return 0;
}
unsigned char command = *((unsigned char*) buffer->start + 4);
switch (command)
{
case 0x1b:
my_session->client_multistatement = *((unsigned char*) buffer->start + 5);
MXS_INFO("tee: client %s multistatements",
my_session->client_multistatement ? "enabled" : "disabled");
case 0x03:
case 0x16:
case 0x17:
case 0x04:
case 0x0a:
memset(my_session->multipacket, (char) true, 2 * sizeof(bool));
break;
default:
memset(my_session->multipacket, (char) false, 2 * sizeof(bool));
break;
}
memset(my_session->replies, 0, 2 * sizeof(int));
memset(my_session->reply_packets, 0, 2 * sizeof(int));
memset(my_session->eof, 0, 2 * sizeof(int));
memset(my_session->waiting, 1, 2 * sizeof(bool));
my_session->command = command;
return 1;
}
/**
* Convert a chain of GWBUF structures into a single GWBUF structure
*
* @param orig The chain to convert
* @return The contiguous buffer
*/
GWBUF *
gwbuf_make_contiguous(GWBUF *orig)
{
GWBUF *newbuf;
char *ptr;
int len;
if (orig->next == NULL)
return orig;
if ((newbuf = gwbuf_alloc(gwbuf_length(orig))) != NULL)
{
newbuf->gwbuf_type = orig->gwbuf_type;
newbuf->hint = hint_dup(orig->hint);
ptr = GWBUF_DATA(newbuf);
while (orig)
{
len = GWBUF_LENGTH(orig);
memcpy(ptr, GWBUF_DATA(orig), len);
ptr += len;
orig = gwbuf_consume(orig, len);
}
}
return newbuf;
}
/**
* The routeQuery entry point. This is passed the query buffer
* to which the filter should be applied. Once applied the
* query should normally be passed to the downstream component
* (filter or router) in the filter chain.
*
* If my_session->residual is set then duplicate that many bytes
* and send them to the branch.
*
* If my_session->residual is zero then this must be a new request
* Extract the SQL text if possible, match against that text and forward
* the request. If the requets is not contained witin the packet we have
* then set my_session->residual to the number of outstanding bytes
*
* @param instance The filter instance data
* @param session The filter session
* @param queue The query data
*/
static int
routeQuery(FILTER *instance, void *session, GWBUF *queue)
{
TEE_INSTANCE *my_instance = (TEE_INSTANCE *)instance;
TEE_SESSION *my_session = (TEE_SESSION *)session;
char *ptr;
int rval;
GWBUF *buffer = NULL, *clone = NULL;
unsigned char command = gwbuf_length(queue) >= 5 ?
*((unsigned char*)queue->start + 4) : 1;
#ifdef SS_DEBUG
skygw_log_write(LOGFILE_TRACE,"Tee routeQuery: %d : %s",
atomic_add(&debug_seq,1),
((char*)queue->start + 5));
#endif
spinlock_acquire(&my_session->tee_lock);
if(!my_session->active)
{
skygw_log_write(LOGFILE_TRACE, "Tee: Received a reply when the session was closed.");
gwbuf_free(queue);
spinlock_release(&my_session->tee_lock);
return 0;
}
if(my_session->queue)
{
my_session->queue = gwbuf_append(my_session->queue,queue);
buffer = modutil_get_next_MySQL_packet(&my_session->queue);
}
else
{
buffer = modutil_get_next_MySQL_packet(&queue);
my_session->queue = queue;
}
if(buffer == NULL)
{
spinlock_release(&my_session->tee_lock);
return 1;
}
clone = clone_query(my_instance, my_session,buffer);
spinlock_release(&my_session->tee_lock);
/* Reset session state */
if(!reset_session_state(my_session,buffer))
return 0;
/** Route query downstream */
spinlock_acquire(&my_session->tee_lock);
rval = route_single_query(my_instance,my_session,buffer,clone);
spinlock_release(&my_session->tee_lock);
return rval;
}
/**
* Process a request packet from the slave server.
*
* The router can handle a limited subset of requests from the slave, these
* include a subset of general SQL queries, a slave registeration command and
* the binlog dump command.
*
* The strategy for responding to these commands is to use caches responses
* for the the same commands that have previously been made to the real master
* if this is possible, if it is not then the router itself will synthesize a
* response.
*
* @param router The router instance this defines the master for this replication chain
* @param slave The slave specific data
* @param queue The incoming request packet
*/
int
blr_slave_request(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue)
{
if (slave->state < 0 || slave->state > BLRS_MAXSTATE)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "Invalid slave state machine state (%d) for binlog router.",
slave->state)));
gwbuf_consume(queue, gwbuf_length(queue));
return 0;
}
slave->stats.n_requests++;
switch (MYSQL_COMMAND(queue))
{
case COM_QUERY:
return blr_slave_query(router, slave, queue);
break;
case COM_REGISTER_SLAVE:
return blr_slave_register(router, slave, queue);
break;
case COM_BINLOG_DUMP:
return blr_slave_binlog_dump(router, slave, queue);
break;
case COM_STATISTICS:
return blr_statistics(router, slave, queue);
break;
case COM_PING:
return blr_ping(router, slave, queue);
break;
case COM_QUIT:
LOGIF(LD, (skygw_log_write(LOGFILE_DEBUG,
"COM_QUIT received from slave with server_id %d",
slave->serverid)));
break;
default:
blr_send_custom_error(slave->dcb, 1, 0,
"MySQL command not supported by the binlog router.");
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"Unexpected MySQL Command (%d) received from slave",
MYSQL_COMMAND(queue))));
break;
}
return 0;
}
/**
* 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;
}
/**
* We have a registered slave that is behind the current leading edge of the
* binlog. We must replay the log entries to bring this node up to speed.
*
* There may be a large number of records to send to the slave, the process
* is triggered by the slave COM_BINLOG_DUMP message and all the events must
* be sent without receiving any new event. This measn there is no trigger into
* MaxScale other than this initial message. However, if we simply send all the
* events we end up with an extremely long write queue on the DCB and risk
* running the server out of resources.
*
* The slave catchup routine will send a burst of replication events per single
* call. The paramter "long" control the number of events in the burst. The
* short burst is intended to be used when the master receive an event and
* needs to put the slave into catchup mode. This prevents the slave taking
* too much tiem away from the thread that is processing the master events.
*
* At the end of the burst a fake EPOLLOUT event is added to the poll event
* queue. This ensures that the slave callback for processing DCB write drain
* will be called and future catchup requests will be handled on another thread.
*
* @param router The binlog router
* @param slave The slave that is behind
* @param large Send a long or short burst of events
* @return The number of bytes written
*/
int
blr_slave_catchup(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, bool large)
{
GWBUF *head, *record;
REP_HEADER hdr;
int written, rval = 1, burst;
int rotating;
unsigned long burst_size;
uint8_t *ptr;
if (large)
burst = router->long_burst;
else
burst = router->short_burst;
burst_size = router->burst_size;
spinlock_acquire(&slave->catch_lock);
if (slave->cstate & CS_BUSY)
{
spinlock_release(&slave->catch_lock);
return 0;
}
slave->cstate |= CS_BUSY;
spinlock_release(&slave->catch_lock);
if (slave->file == NULL)
{
rotating = router->rotating;
if ((slave->file = blr_open_binlog(router, slave->binlogfile)) == NULL)
{
if (rotating)
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
return rval;
}
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"blr_slave_catchup failed to open binlog file %s",
slave->binlogfile)));
slave->cstate &= ~CS_BUSY;
slave->state = BLRS_ERRORED;
dcb_close(slave->dcb);
return 0;
}
}
slave->stats.n_bursts++;
while (burst-- && burst_size > 0 &&
(record = blr_read_binlog(router, slave->file, slave->binlog_pos, &hdr)) != NULL)
{
head = gwbuf_alloc(5);
ptr = GWBUF_DATA(head);
encode_value(ptr, hdr.event_size + 1, 24);
ptr += 3;
*ptr++ = slave->seqno++;
*ptr++ = 0; // OK
head = gwbuf_append(head, record);
if (hdr.event_type == ROTATE_EVENT)
{
unsigned long beat1 = hkheartbeat;
blr_close_binlog(router, slave->file);
if (hkheartbeat - beat1 > 1) LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "blr_close_binlog took %d beats",
hkheartbeat - beat1)));
blr_slave_rotate(slave, GWBUF_DATA(record));
beat1 = hkheartbeat;
if ((slave->file = blr_open_binlog(router, slave->binlogfile)) == NULL)
{
if (rotating)
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
return rval;
}
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"blr_slave_catchup failed to open binlog file %s",
slave->binlogfile)));
slave->state = BLRS_ERRORED;
dcb_close(slave->dcb);
break;
}
if (hkheartbeat - beat1 > 1) LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "blr_open_binlog took %d beats",
hkheartbeat - beat1)));
}
slave->stats.n_bytes += gwbuf_length(head);
written = slave->dcb->func.write(slave->dcb, head);
if (written && hdr.event_type != ROTATE_EVENT)
{
slave->binlog_pos = hdr.next_pos;
}
rval = written;
slave->stats.n_events++;
burst_size -= hdr.event_size;
}
if (record == NULL)
slave->stats.n_failed_read++;
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
if (record)
{
slave->stats.n_flows++;
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
else if (slave->binlog_pos == router->binlog_position &&
strcmp(slave->binlogfile, router->binlog_name) == 0)
{
int state_change = 0;
spinlock_acquire(&router->binlog_lock);
spinlock_acquire(&slave->catch_lock);
/*
* Now check again since we hold the router->binlog_lock
* and slave->catch_lock.
*/
if (slave->binlog_pos != router->binlog_position ||
strcmp(slave->binlogfile, router->binlog_name) != 0)
{
slave->cstate &= ~CS_UPTODATE;
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
spinlock_release(&router->binlog_lock);
poll_fake_write_event(slave->dcb);
}
else
{
if ((slave->cstate & CS_UPTODATE) == 0)
{
slave->stats.n_upd++;
slave->cstate |= CS_UPTODATE;
spinlock_release(&slave->catch_lock);
spinlock_release(&router->binlog_lock);
state_change = 1;
}
}
if (state_change)
{
slave->stats.n_caughtup++;
if (slave->stats.n_caughtup == 1)
{
LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE,
"%s: Slave %s is up to date %s, %u.",
router->service->name,
slave->dcb->remote,
slave->binlogfile, slave->binlog_pos)));
}
else if ((slave->stats.n_caughtup % 50) == 0)
{
LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE,
"%s: Slave %s is up to date %s, %u.",
router->service->name,
slave->dcb->remote,
slave->binlogfile, slave->binlog_pos)));
}
}
}
else
{
if (slave->binlog_pos >= blr_file_size(slave->file)
&& router->rotating == 0
&& strcmp(router->binlog_name, slave->binlogfile) != 0
&& blr_master_connected(router))
{
/* We may have reached the end of file of a non-current
* binlog file.
*
* Note if the master is rotating there is a window during
* which the rotate event has been written to the old binlog
* but the new binlog file has not yet been created. Therefore
* we ignore these issues during the rotate processing.
*/
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Slave reached end of file for binlong file %s at %u "
"which is not the file currently being downloaded. "
"Master binlog is %s, %lu.",
slave->binlogfile, slave->binlog_pos,
router->binlog_name, router->binlog_position)));
if (blr_slave_fake_rotate(router, slave))
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
else
{
slave->state = BLRS_ERRORED;
dcb_close(slave->dcb);
}
}
else
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
}
return rval;
}
/**
* Read the backend server MySQL handshake
*
* @param conn MySQL protocol structure
* @return 0 on success, 1 on failure
*/
int gw_read_backend_handshake(MySQLProtocol *conn) {
GWBUF *head = NULL;
DCB *dcb = conn->owner_dcb;
int n = -1;
uint8_t *payload = NULL;
int h_len = 0;
int success = 0;
int packet_len = 0;
if ((n = dcb_read(dcb, &head)) != -1) {
if (head) {
payload = GWBUF_DATA(head);
h_len = gwbuf_length(head);
/*
* The mysql packets content starts at byte fifth
* just return with less bytes
*/
if (h_len <= 4) {
/* log error this exit point */
conn->state = MYSQL_AUTH_FAILED;
return 1;
}
//get mysql packet size, 3 bytes
packet_len = gw_mysql_get_byte3(payload);
if (h_len < (packet_len + 4)) {
/*
* data in buffer less than expected in the
* packet. Log error this exit point
*/
conn->state = MYSQL_AUTH_FAILED;
return 1;
}
// skip the 4 bytes header
payload += 4;
//Now decode mysql handshake
success = gw_decode_mysql_server_handshake(conn,
payload);
if (success < 0) {
/* MySQL handshake has not been properly decoded
* we cannot continue
* log error this exit point
*/
conn->state = MYSQL_AUTH_FAILED;
return 1;
}
conn->state = MYSQL_AUTH_SENT;
// consume all the data here
head = gwbuf_consume(head, GWBUF_LENGTH(head));
return 0;
}
}
// Nothing done here, log error this
return 1;
}
