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MaxScale/server/modules/protocol/MySQL/mariadbbackend/mysql_backend.cc
Johan Wikman cc0299aee6 Update change date of 2.3
2018-06-25 10:07:52 +03:00

2214 lines
70 KiB
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/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
*
* Change Date: 2022-01-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
#define MXS_MODULE_NAME "mariadbbackend"
#include <maxscale/alloc.h>
#include <maxscale/limits.h>
#include <maxscale/log_manager.h>
#include <maxscale/modinfo.h>
#include <maxscale/modutil.h>
#include <maxscale/poll.h>
#include <maxscale/protocol.h>
#include <maxscale/protocol/mysql.h>
#include <maxscale/router.h>
#include <maxscale/server.hh>
#include <maxscale/utils.h>
/*
* MySQL Protocol module for handling the protocol between the gateway
* and the backend MySQL database.
*/
static int gw_create_backend_connection(DCB *backend, SERVER *server, MXS_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, GWBUF *buffer);
static void backend_set_delayqueue(DCB *dcb, GWBUF *queue);
static int gw_change_user(DCB *backend_dcb, SERVER *server, MXS_SESSION *in_session, GWBUF *queue);
static char *gw_backend_default_auth();
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);
static bool sescmd_response_complete(DCB* dcb);
static void gw_reply_on_error(DCB *dcb, mxs_auth_state_t state);
static int gw_read_and_write(DCB *dcb);
static int gw_do_connect_to_backend(char *host, int port, int *fd);
static void inline close_socket(int socket);
static GWBUF *gw_create_change_user_packet(MYSQL_session* mses,
MySQLProtocol* protocol);
static int gw_send_change_user_to_backend(char *dbname,
char *user,
uint8_t *passwd,
MySQLProtocol *conn);
static void gw_send_proxy_protocol_header(DCB *backend_dcb);
static bool get_ip_string_and_port(struct sockaddr_storage *sa, char *ip, int iplen,
in_port_t *port_out);
static bool gw_connection_established(DCB* dcb);
json_t* gw_json_diagnostics(DCB* dcb);
extern "C"
{
/*
* 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
*/
MXS_MODULE* MXS_CREATE_MODULE()
{
static MXS_PROTOCOL 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 */
gw_backend_default_auth, /* Default authenticator */
NULL, /* Connection limit reached */
gw_connection_established,
gw_json_diagnostics,
};
static MXS_MODULE info =
{
MXS_MODULE_API_PROTOCOL,
MXS_MODULE_GA,
MXS_PROTOCOL_VERSION,
"The MySQL to backend server protocol",
"V2.0.0",
MXS_NO_MODULE_CAPABILITIES,
&MyObject,
NULL, /* Process init. */
NULL, /* Process finish. */
NULL, /* Thread init. */
NULL, /* Thread finish. */
{
{MXS_END_MODULE_PARAMS}
}
};
return &info;
}
}
/**
* The default authenticator name for this protocol
*
* This is not used for a backend protocol, it is for client authentication.
*
* @return name of authenticator
*/
static char *gw_backend_default_auth()
{
return const_cast<char*>("MySQLBackendAuth");
}
/*lint +e14 */
/*******************************************************************************
*******************************************************************************
*
* API Entry Point - Connect
*
* This is the first entry point that will be called in the life of a backend
* (database) connection. It creates a protocol data structure and attempts
* to open a non-blocking socket to the database. If it succeeds, the
* protocol_auth_state will become MYSQL_CONNECTED.
*
*******************************************************************************
******************************************************************************/
/*
* 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,
MXS_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)
{
MXS_ERROR("Failed to create protocol object for backend connection.");
goto return_fd;
}
/** Copy client flags to backend protocol */
if (backend_dcb->session->client_dcb->protocol)
{
MySQLProtocol *client = (MySQLProtocol*)backend_dcb->session->client_dcb->protocol;
protocol->client_capabilities = client->client_capabilities;
protocol->charset = client->charset;
protocol->extra_capabilities = client->extra_capabilities;
}
else
{
protocol->client_capabilities = (int)GW_MYSQL_CAPABILITIES_CLIENT;
protocol->charset = 0x08;
}
/*< if succeed, fd > 0, -1 otherwise */
/* TODO: Better if function returned a protocol auth state */
rv = gw_do_connect_to_backend(server->address, 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 = MXS_AUTH_STATE_CONNECTED;
MXS_DEBUG("Established "
"connection to %s:%i, protocol fd %d client "
"fd %d.",
server->address,
server->port,
protocol->fd,
session->client_dcb->fd);
if (server->proxy_protocol)
{
gw_send_proxy_protocol_header(backend_dcb);
}
break;
case 1:
/* The state MYSQL_PENDING_CONNECT is likely to be transitory, */
/* as it means the calls have been successful but the connection */
/* has not yet completed and the calls are non-blocking. */
ss_dassert(fd > 0);
protocol->protocol_auth_state = MXS_AUTH_STATE_PENDING_CONNECT;
protocol->fd = fd;
MXS_DEBUG("Connection "
"pending to %s:%i, protocol fd %d client fd %d.",
server->address,
server->port,
protocol->fd,
session->client_dcb->fd);
break;
default:
/* Failure - the state reverts to its initial value */
ss_dassert(fd == -1);
ss_dassert(protocol->protocol_auth_state == MXS_AUTH_STATE_INIT);
break;
} /*< switch */
return_fd:
return fd;
}
/**
* gw_do_connect_to_backend
*
* This routine creates socket and connects to a backend server.
* Connect it non-blocking operation. If connect fails, socket is closed.
*
* @param host The host to connect to
* @param port The host TCP/IP port
* @param *fd where connected fd is copied
* @return 0/1 on success and -1 on failure
* If successful, fd has file descriptor to socket which is connected to
* backend server. In failure, fd == -1 and socket is closed.
*
*/
static int gw_do_connect_to_backend(char *host, int port, int *fd)
{
struct sockaddr_storage serv_addr = {};
int rv = -1;
/* prepare for connect */
int so = open_network_socket(MXS_SOCKET_NETWORK, &serv_addr, host, port);
if (so == -1)
{
MXS_ERROR("Establishing connection to backend server [%s]:%d failed.", host, port);
return rv;
}
rv = connect(so, (struct sockaddr *)&serv_addr, sizeof(serv_addr));
if (rv != 0)
{
if (errno == EINPROGRESS)
{
rv = 1;
}
else
{
MXS_ERROR("Failed to connect backend server [%s]:%d due to: %d, %s.",
host, port, errno, mxs_strerror(errno));
close(so);
return rv;
}
}
*fd = so;
MXS_DEBUG("Connected to backend server [%s]:%d, fd %d.", host, port, so);
return rv;
}
/**
* @brief Check if the response contain an error
*
* @param buffer Buffer with a complete response
* @return True if the reponse contains an MySQL error packet
*/
bool is_error_response(GWBUF *buffer)
{
uint8_t cmd;
return gwbuf_copy_data(buffer, MYSQL_HEADER_LEN, 1, &cmd) && cmd == MYSQL_REPLY_ERR;
}
/**
* @brief Log handshake failure
*
* @param dcb Backend DCB where authentication failed
* @param buffer Buffer containing the response from the backend
*/
static void handle_error_response(DCB *dcb, GWBUF *buffer)
{
uint8_t *data = (uint8_t*)GWBUF_DATA(buffer);
size_t len = MYSQL_GET_PAYLOAD_LEN(data);
uint16_t errcode = MYSQL_GET_ERRCODE(data);
char bufstr[len];
memcpy(bufstr, data + 7, len - 3);
bufstr[len - 3] = '\0';
MXS_ERROR("Invalid authentication message from backend '%s'. Error code: %d, "
"Msg : %s", dcb->server->name, errcode, bufstr);
/** If the error is ER_HOST_IS_BLOCKED put the server into maintenace mode.
* This will prevent repeated authentication failures. */
if (errcode == ER_HOST_IS_BLOCKED)
{
MXS_ERROR("Server %s has been put into maintenance mode due "
"to the server blocking connections from MaxScale. "
"Run 'mysqladmin -h %s -P %d flush-hosts' on this "
"server before taking this server out of maintenance "
"mode.", dcb->server->name,
dcb->server->address, dcb->server->port);
mxs::server_set_status(dcb->server, SERVER_MAINT, NULL);
}
else if (errcode == ER_ACCESS_DENIED_ERROR ||
errcode == ER_DBACCESS_DENIED_ERROR ||
errcode == ER_ACCESS_DENIED_NO_PASSWORD_ERROR)
{
if (dcb->session->state != SESSION_STATE_DUMMY)
{
// Authentication failed, reload users
service_refresh_users(dcb->service);
}
}
}
/**
* @brief Handle the server's response packet
*
* This function reads the server's response packet and does the final step of
* the authentication.
*
* @param dcb Backend DCB
* @param buffer Buffer containing the server's complete handshake
* @return MXS_AUTH_STATE_HANDSHAKE_FAILED on failure.
*/
mxs_auth_state_t handle_server_response(DCB *dcb, GWBUF *buffer)
{
MySQLProtocol *proto = (MySQLProtocol*)dcb->protocol;
mxs_auth_state_t rval = proto->protocol_auth_state == MXS_AUTH_STATE_CONNECTED ?
MXS_AUTH_STATE_HANDSHAKE_FAILED : MXS_AUTH_STATE_FAILED;
if (dcb->authfunc.extract(dcb, buffer))
{
switch (dcb->authfunc.authenticate(dcb))
{
case MXS_AUTH_INCOMPLETE:
case MXS_AUTH_SSL_INCOMPLETE:
rval = MXS_AUTH_STATE_RESPONSE_SENT;
break;
case MXS_AUTH_SUCCEEDED:
rval = MXS_AUTH_STATE_COMPLETE;
default:
break;
}
}
return rval;
}
/**
* @brief Prepare protocol for a write
*
* This prepares both the buffer and the protocol itself for writing a query
* to the backend.
*
* @param dcb The backend DCB to write to
* @param buffer Buffer that will be written
*/
static inline void prepare_for_write(DCB *dcb, GWBUF *buffer)
{
MySQLProtocol *proto = (MySQLProtocol*)dcb->protocol;
/**
* The DCB's session is set to the dummy session when it is put into the
* persistent connection pool. If this is not the dummy session, track
* the current command being executed.
*/
if (!session_is_dummy(dcb->session))
{
uint64_t capabilities = service_get_capabilities(dcb->session->service);
/**
* Copy the current command being executed to this backend. For statement
* based routers, this is tracked by using the current command being executed.
* For routers that stream data, the client protocol command tracking data
* is used which does not guarantee that the correct command is tracked if
* something queues commands internally.
*/
if (rcap_type_required(capabilities, RCAP_TYPE_STMT_INPUT))
{
uint8_t* data = GWBUF_DATA(buffer);
if (!proto->large_query)
{
proto->current_command = (mxs_mysql_cmd_t)MYSQL_GET_COMMAND(data);
}
/**
* If the buffer contains a large query, we have to skip the command
* byte extraction for the next packet. This way current_command always
* contains the latest command executed on this backend.
*/
proto->large_query = MYSQL_GET_PAYLOAD_LEN(data) == MYSQL_PACKET_LENGTH_MAX;
}
else if (dcb->session->client_dcb && dcb->session->client_dcb->protocol)
{
MySQLProtocol *client_proto = (MySQLProtocol*)dcb->session->client_dcb->protocol;
proto->current_command = client_proto->current_command;
}
}
if (GWBUF_IS_TYPE_SESCMD(buffer))
{
mxs_mysql_cmd_t cmd = static_cast<mxs_mysql_cmd_t>(mxs_mysql_get_command(buffer));
protocol_add_srv_command(proto, cmd);
}
if (GWBUF_SHOULD_COLLECT_RESULT(buffer))
{
proto->collect_result = true;
}
}
/*******************************************************************************
*******************************************************************************
*
* API Entry Point - Read
*
* When the polling mechanism finds that new incoming data is available for
* a backend connection, it will call this entry point, passing the relevant
* DCB.
*
* The first time through, it is expected that protocol_auth_state will be
* MYSQL_CONNECTED and an attempt will be made to send authentication data
* to the backend server. The state may progress to MYSQL_AUTH_REC although
* for an SSL connection this will not happen straight away, and the state
* will remain MYSQL_CONNECTED.
*
* When the connection is fully established, it is expected that the state
* will be MYSQL_IDLE and the information read from the backend will be
* transferred to the client (front end).
*
*******************************************************************************
******************************************************************************/
/**
* 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)
{
CHK_DCB(dcb);
if (dcb->persistentstart)
{
/** If a DCB gets a read event when it's in the persistent pool, it is
* treated as if it were an error. */
dcb->dcb_errhandle_called = true;
return 0;
}
if (dcb->session == NULL ||
dcb->session->state == SESSION_STATE_DUMMY)
{
return 0;
}
CHK_SESSION(dcb->session);
MySQLProtocol *proto = (MySQLProtocol *)dcb->protocol;
CHK_PROTOCOL(proto);
MXS_DEBUG("Read dcb %p fd %d protocol state %d, %s.", dcb, dcb->fd,
proto->protocol_auth_state, STRPROTOCOLSTATE(proto->protocol_auth_state));
int rc = 0;
if (proto->protocol_auth_state == MXS_AUTH_STATE_COMPLETE)
{
rc = gw_read_and_write(dcb);
}
else
{
GWBUF *readbuf = NULL;
if (!read_complete_packet(dcb, &readbuf))
{
proto->protocol_auth_state = MXS_AUTH_STATE_FAILED;
gw_reply_on_error(dcb, proto->protocol_auth_state);
}
else if (readbuf)
{
/** We have a complete response from the server */
/** TODO: add support for non-contiguous responses */
readbuf = gwbuf_make_contiguous(readbuf);
MXS_ABORT_IF_NULL(readbuf);
if (is_error_response(readbuf))
{
/** The server responded with an error */
proto->protocol_auth_state = MXS_AUTH_STATE_FAILED;
handle_error_response(dcb, readbuf);
}
if (proto->protocol_auth_state == MXS_AUTH_STATE_CONNECTED)
{
mxs_auth_state_t state = MXS_AUTH_STATE_FAILED;
/** Read the server handshake and send the standard response */
if (gw_read_backend_handshake(dcb, readbuf))
{
state = gw_send_backend_auth(dcb);
}
proto->protocol_auth_state = state;
}
else if (proto->protocol_auth_state == MXS_AUTH_STATE_RESPONSE_SENT)
{
/** Read the message from the server. This will be the first
* packet that can contain authenticator specific data from the
* backend server. For 'mysql_native_password' it'll be an OK
* packet */
proto->protocol_auth_state = handle_server_response(dcb, readbuf);
}
if (proto->protocol_auth_state == MXS_AUTH_STATE_COMPLETE)
{
/** Authentication completed successfully */
GWBUF *localq = dcb->delayq;
dcb->delayq = NULL;
if (localq)
{
/** Send the queued commands to the backend */
prepare_for_write(dcb, localq);
rc = backend_write_delayqueue(dcb, localq);
}
}
else if (proto->protocol_auth_state == MXS_AUTH_STATE_FAILED ||
proto->protocol_auth_state == MXS_AUTH_STATE_HANDSHAKE_FAILED)
{
/** Authentication failed */
gw_reply_on_error(dcb, proto->protocol_auth_state);
}
gwbuf_free(readbuf);
}
else if (proto->protocol_auth_state == MXS_AUTH_STATE_CONNECTED &&
dcb->ssl_state == SSL_ESTABLISHED)
{
proto->protocol_auth_state = gw_send_backend_auth(dcb);
}
}
return rc;
}
static void do_handle_error(DCB *dcb, mxs_error_action_t action, const char *errmsg)
{
bool succp = true;
MXS_SESSION *session = dcb->session;
if (!dcb->dcb_errhandle_called)
{
GWBUF *errbuf = mysql_create_custom_error(1, 0, errmsg);
MXS_ROUTER_SESSION *rsession = static_cast<MXS_ROUTER_SESSION*>(session->router_session);
MXS_ROUTER_OBJECT *router = session->service->router;
MXS_ROUTER *router_instance = session->service->router_instance;
router->handleError(router_instance, rsession, errbuf,
dcb, action, &succp);
gwbuf_free(errbuf);
dcb->dcb_errhandle_called = true;
}
/**
* 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)
{
session->close_reason = SESSION_CLOSE_HANDLEERROR_FAILED;
poll_fake_hangup_event(session->client_dcb);
}
}
/**
* @brief Authentication of backend - read the reply, or handle an error
*
* @param dcb Descriptor control block for backend server
* @param local_session The current MySQL session data structure
* @return
*/
static void gw_reply_on_error(DCB *dcb, mxs_auth_state_t state)
{
MXS_SESSION *session = dcb->session;
CHK_SESSION(session);
do_handle_error(dcb, ERRACT_REPLY_CLIENT,
"Authentication with backend failed. Session will be closed.");
}
/**
* @brief Check if a reply can be routed to the client
*
* @param Backend DCB
* @return True if session is ready for reply routing
*/
static inline bool session_ok_to_route(DCB *dcb)
{
bool rval = false;
if (dcb->session->state == SESSION_STATE_ROUTER_READY &&
dcb->session->client_dcb != NULL &&
dcb->session->client_dcb->state == DCB_STATE_POLLING &&
(dcb->session->router_session ||
service_get_capabilities(dcb->session->service) & RCAP_TYPE_NO_RSESSION))
{
MySQLProtocol *client_protocol = (MySQLProtocol *)dcb->session->client_dcb->protocol;
if (client_protocol)
{
CHK_PROTOCOL(client_protocol);
if (client_protocol->protocol_auth_state == MXS_AUTH_STATE_COMPLETE)
{
rval = true;
}
}
else if (dcb->session->client_dcb->dcb_role == DCB_ROLE_INTERNAL)
{
rval = true;
}
}
return rval;
}
static inline bool expecting_resultset(MySQLProtocol *proto)
{
return proto->current_command == MXS_COM_QUERY ||
proto->current_command == MXS_COM_STMT_FETCH;
}
static inline bool expecting_ps_response(MySQLProtocol *proto)
{
return proto->current_command == MXS_COM_STMT_PREPARE;
}
static inline bool complete_ps_response(GWBUF *buffer)
{
ss_dassert(GWBUF_IS_CONTIGUOUS(buffer));
MXS_PS_RESPONSE resp;
bool rval = false;
if (mxs_mysql_extract_ps_response(buffer, &resp))
{
int expected_eof = 0;
if (resp.columns > 0)
{
expected_eof++;
}
if (resp.parameters > 0)
{
expected_eof++;
}
bool more;
int n_eof = modutil_count_signal_packets(buffer, 0, &more, NULL);
MXS_DEBUG("Expecting %u EOF, have %u", n_eof, expected_eof);
rval = n_eof == expected_eof;
}
return rval;
}
static inline bool collecting_resultset(MySQLProtocol *proto, uint64_t capabilities)
{
return rcap_type_required(capabilities, RCAP_TYPE_RESULTSET_OUTPUT) ||
proto->collect_result;
}
/**
* Helpers for checking OK and ERR packets specific to COM_CHANGE_USER
*/
static inline bool not_ok_packet(const GWBUF* buffer)
{
uint8_t* data = GWBUF_DATA(buffer);
return data[4] != MYSQL_REPLY_OK ||
// Should be more than 7 bytes of payload
gw_mysql_get_byte3(data) < MYSQL_OK_PACKET_MIN_LEN - MYSQL_HEADER_LEN ||
// Should have no affected rows
data[5] != 0 ||
// Should not generate an insert ID
data[6] != 0;
}
static inline bool not_err_packet(const GWBUF* buffer)
{
return GWBUF_DATA(buffer)[4] != MYSQL_REPLY_ERR;
}
static inline bool auth_change_requested(GWBUF* buf)
{
return mxs_mysql_get_command(buf) == MYSQL_REPLY_AUTHSWITCHREQUEST &&
gwbuf_length(buf) > MYSQL_EOF_PACKET_LEN;
}
static bool handle_auth_change_response(GWBUF* reply, MySQLProtocol* proto, DCB* dcb)
{
bool rval = false;
if (strcmp((char*)GWBUF_DATA(reply) + 5, DEFAULT_MYSQL_AUTH_PLUGIN) == 0)
{
/**
* The server requested a change of authentication methods.
* If we're changing the authentication method to the same one we
* are using now, it means that the server is simply generating
* a new scramble for the re-authentication process.
*/
// Load the new scramble into the protocol...
gwbuf_copy_data(reply, 5 + strlen(DEFAULT_MYSQL_AUTH_PLUGIN) + 1,
GW_MYSQL_SCRAMBLE_SIZE, proto->scramble);
/// ... and use it to send the encrypted password to the server
rval = send_mysql_native_password_response(dcb);
}
return rval;
}
/**
* @brief With authentication completed, read new data and write to backend
*
* @param dcb Descriptor control block for backend server
* @param local_session Current MySQL session data structure
* @return 0 is fail, 1 is success
*/
static int
gw_read_and_write(DCB *dcb)
{
GWBUF *read_buffer = NULL;
MXS_SESSION *session = dcb->session;
int nbytes_read;
int return_code = 0;
CHK_SESSION(session);
/* read available backend data */
return_code = dcb_read(dcb, &read_buffer, 0);
if (return_code < 0)
{
do_handle_error(dcb, ERRACT_NEW_CONNECTION, "Read from backend failed");
return 0;
}
nbytes_read = gwbuf_length(read_buffer);
if (nbytes_read == 0)
{
ss_dassert(read_buffer == NULL);
return return_code;
}
else
{
ss_dassert(read_buffer != NULL);
}
/** Ask what type of output the router/filter chain expects */
uint64_t capabilities = service_get_capabilities(session->service);
bool result_collected = false;
MySQLProtocol *proto = (MySQLProtocol *)dcb->protocol;
if (rcap_type_required(capabilities, RCAP_TYPE_PACKET_OUTPUT) ||
rcap_type_required(capabilities, RCAP_TYPE_CONTIGUOUS_OUTPUT) ||
proto->collect_result ||
proto->ignore_replies != 0)
{
GWBUF *tmp = modutil_get_complete_packets(&read_buffer);
/* Put any residue into the read queue */
dcb_readq_set(dcb, read_buffer);
if (tmp == NULL)
{
/** No complete packets */
return 0;
}
/** Get sesion track info from ok packet and save it to gwbuf properties.
*
* The OK packets sent in response to COM_STMT_PREPARE are of a different
* format so we need to detect and skip them. */
if (rcap_type_required(capabilities, RCAP_TYPE_SESSION_STATE_TRACKING) &&
!expecting_ps_response(proto))
{
mxs_mysql_get_session_track_info(tmp, proto);
}
read_buffer = tmp;
if (rcap_type_required(capabilities, RCAP_TYPE_CONTIGUOUS_OUTPUT) ||
proto->collect_result ||
proto->ignore_replies != 0)
{
if ((tmp = gwbuf_make_contiguous(read_buffer)))
{
read_buffer = tmp;
}
else
{
/** Failed to make the buffer contiguous */
gwbuf_free(read_buffer);
poll_fake_hangup_event(dcb);
return 0;
}
if (collecting_resultset(proto, capabilities))
{
if (expecting_resultset(proto))
{
if (mxs_mysql_is_result_set(read_buffer))
{
bool more = false;
if (modutil_count_signal_packets(read_buffer, 0, &more, NULL) != 2)
{
dcb_readq_prepend(dcb, read_buffer);
return 0;
}
}
// Collected the complete result
proto->collect_result = false;
result_collected = true;
}
else if (expecting_ps_response(proto) &&
mxs_mysql_is_prep_stmt_ok(read_buffer))
{
if (!complete_ps_response(read_buffer))
{
dcb_readq_prepend(dcb, read_buffer);
return 0;
}
// Collected the complete result
proto->collect_result = false;
result_collected = true;
}
}
}
}
if (proto->changing_user)
{
if (auth_change_requested(read_buffer) &&
handle_auth_change_response(read_buffer, proto, dcb))
{
return 0;
}
else
{
/**
* The client protocol always requests an authentication method
* switch to the same plugin to be compatible with most connectors.
*
* To prevent packet sequence number mismatch, always return a sequence
* of 3 for the final response to a COM_CHANGE_USER.
*/
GWBUF_DATA(read_buffer)[3] = 0x3;
proto->changing_user = false;
}
}
if (proto->ignore_replies > 0)
{
/** The reply to a COM_CHANGE_USER is in packet */
GWBUF *query = proto->stored_query;
proto->stored_query = NULL;
proto->ignore_replies--;
ss_dassert(proto->ignore_replies >= 0);
GWBUF* reply = modutil_get_next_MySQL_packet(&read_buffer);
while (read_buffer)
{
/** Skip to the last packet if we get more than one */
gwbuf_free(reply);
reply = modutil_get_next_MySQL_packet(&read_buffer);
}
ss_dassert(reply);
ss_dassert(!read_buffer);
uint8_t result = MYSQL_GET_COMMAND(GWBUF_DATA(reply));
int rval = 0;
if (result == MYSQL_REPLY_OK)
{
MXS_INFO("Response to COM_CHANGE_USER is OK, writing stored query");
rval = query ? dcb->func.write(dcb, query) : 1;
}
else if (auth_change_requested(reply))
{
if (handle_auth_change_response(reply, proto, dcb))
{
/** Store the query until we know the result of the authentication
* method switch. */
proto->stored_query = query;
proto->ignore_replies++;
gwbuf_free(reply);
return rval;
}
else
{
/** The server requested a change to something other than
* the default auth plugin */
gwbuf_free(query);
poll_fake_hangup_event(dcb);
// TODO: Use the authenticators to handle COM_CHANGE_USER responses
MXS_ERROR("Received AuthSwitchRequest to '%s' when '%s' was expected",
(char*)GWBUF_DATA(reply) + 5, DEFAULT_MYSQL_AUTH_PLUGIN);
}
}
else
{
/**
* The ignorable command failed when we had a queued query from the
* client. Generate a fake hangup event to close the DCB and send
* an error to the client.
*/
if (result == MYSQL_REPLY_ERR)
{
/** The COM_CHANGE USER failed, generate a fake hangup event to
* close the DCB and send an error to the client. */
handle_error_response(dcb, reply);
}
else
{
/** This should never happen */
MXS_ERROR("Unknown response to COM_CHANGE_USER (0x%02hhx), "
"closing connection", result);
}
gwbuf_free(query);
poll_fake_hangup_event(dcb);
}
gwbuf_free(reply);
return rval;
}
do
{
GWBUF *stmt = NULL;
/**
* If protocol has session command set, concatenate whole
* response into one buffer.
*/
if (protocol_get_srv_command((MySQLProtocol *)dcb->protocol, true) != MXS_COM_UNDEFINED)
{
if (result_collected)
{
/** The result set or PS response was collected, we know it's complete */
stmt = read_buffer;
read_buffer = NULL;
gwbuf_set_type(stmt, GWBUF_TYPE_RESPONSE_END | GWBUF_TYPE_SESCMD_RESPONSE);
}
else
{
stmt = process_response_data(dcb, &read_buffer, gwbuf_length(read_buffer));
/**
* Received incomplete response to session command.
* Store it to readqueue and return.
*/
if (!sescmd_response_complete(dcb))
{
stmt = gwbuf_append(stmt, read_buffer);
dcb_readq_prepend(dcb, stmt);
return 0;
}
}
if (!stmt)
{
MXS_ERROR("Read buffer unexpectedly null, even though response "
"not marked as complete. User: %s", dcb->session->client_dcb->user);
return 0;
}
}
else if (rcap_type_required(capabilities, RCAP_TYPE_STMT_OUTPUT) &&
!rcap_type_required(capabilities, RCAP_TYPE_RESULTSET_OUTPUT) &&
!result_collected)
{
stmt = modutil_get_next_MySQL_packet(&read_buffer);
if (!GWBUF_IS_CONTIGUOUS(stmt))
{
// Make sure the buffer is contiguous
stmt = gwbuf_make_contiguous(stmt);
}
}
else
{
stmt = read_buffer;
read_buffer = NULL;
}
if (session_ok_to_route(dcb))
{
if (result_collected)
{
// Mark that this is a buffer containing a collected result
gwbuf_set_type(stmt, GWBUF_TYPE_RESULT);
}
session->service->router->clientReply(session->service->router_instance,
session->router_session,
stmt, dcb);
return_code = 1;
}
else /*< session is closing; replying to client isn't possible */
{
gwbuf_free(stmt);
}
}
while (read_buffer);
return return_code;
}
/*
* 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 = 1;
if (dcb->state != DCB_STATE_POLLING)
{
/** Don't write to backend if backend_dcb is not in poll set anymore */
uint8_t* data = NULL;
bool com_quit = false;
if (dcb->writeq)
{
data = (uint8_t *) GWBUF_DATA(dcb->writeq);
com_quit = MYSQL_IS_COM_QUIT(data);
}
if (data)
{
rc = 0;
if (!com_quit)
{
mysql_send_custom_error(dcb->session->client_dcb, 1, 0,
"Writing to backend failed due invalid Maxscale state.");
MXS_ERROR("Attempt to write buffered data to backend "
"failed due internal inconsistent state: %s",
STRDCBSTATE(dcb->state));
}
}
else
{
MXS_DEBUG("Dcb %p in state %s but there's nothing to write either.",
dcb, STRDCBSTATE(dcb->state));
}
}
else
{
MySQLProtocol *backend_protocol = (MySQLProtocol*)dcb->protocol;
if (backend_protocol->protocol_auth_state == MXS_AUTH_STATE_PENDING_CONNECT)
{
backend_protocol->protocol_auth_state = MXS_AUTH_STATE_CONNECTED;
if (dcb->server->proxy_protocol)
{
gw_send_proxy_protocol_header(dcb);
}
}
else
{
dcb_drain_writeq(dcb);
}
MXS_DEBUG("wrote to dcb %p fd %d, return %d", 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 = static_cast<MySQLProtocol*>(dcb->protocol);
int rc = 0;
CHK_DCB(dcb);
if (dcb->was_persistent)
{
ss_dassert(!dcb->fakeq);
ss_dassert(!dcb->readq);
ss_dassert(!dcb->delayq);
ss_dassert(!dcb->writeq);
ss_dassert(dcb->persistentstart == 0);
dcb->was_persistent = false;
ss_dassert(backend_protocol->ignore_replies >= 0);
backend_protocol->ignore_replies = 0;
if (dcb->state != DCB_STATE_POLLING ||
backend_protocol->protocol_auth_state != MXS_AUTH_STATE_COMPLETE)
{
MXS_INFO("DCB and protocol state do not qualify for pooling: %s, %s",
STRDCBSTATE(dcb->state),
STRPROTOCOLSTATE(backend_protocol->protocol_auth_state));
gwbuf_free(queue);
return 0;
}
/**
* This is a DCB that was just taken out of the persistent connection pool.
* We need to sent a COM_CHANGE_USER query to the backend to reset the
* session state.
*/
if (backend_protocol->stored_query)
{
/** It is possible that the client DCB is closed before the COM_CHANGE_USER
* response is received. */
gwbuf_free(backend_protocol->stored_query);
}
if (MYSQL_IS_COM_QUIT(GWBUF_DATA(queue)))
{
/** The connection is being closed before the first write to this
* backend was done. The COM_QUIT is ignored and the DCB will be put
* back into the pool once it's closed. */
MXS_INFO("COM_QUIT received as the first write, ignoring and "
"sending the DCB back to the pool.");
gwbuf_free(queue);
return 1;
}
GWBUF *buf = gw_create_change_user_packet(static_cast<MYSQL_session*>(dcb->session->client_dcb->data),
static_cast<MySQLProtocol*>(dcb->protocol));
int rc = 0;
if (dcb_write(dcb, buf))
{
MXS_INFO("Sent COM_CHANGE_USER");
backend_protocol->ignore_replies++;
backend_protocol->stored_query = queue;
rc = 1;
}
else
{
gwbuf_free(queue);
}
return rc;
}
else if (backend_protocol->ignore_replies > 0)
{
if (MYSQL_IS_COM_QUIT((uint8_t*)GWBUF_DATA(queue)))
{
/** The COM_CHANGE_USER was already sent but the session is already
* closing. */
MXS_INFO("COM_QUIT received while COM_CHANGE_USER is in progress, closing pooled connection");
gwbuf_free(queue);
poll_fake_hangup_event(dcb);
rc = 0;
}
else
{
/**
* We're still waiting on the reply to the COM_CHANGE_USER, append the
* buffer to the stored query. This is possible if the client sends
* BLOB data on the first command or is sending multiple COM_QUERY
* packets at one time.
*/
MXS_INFO("COM_CHANGE_USER in progress, appending query to queue");
backend_protocol->stored_query = gwbuf_append(backend_protocol->stored_query, queue);
rc = 1;
}
return rc;
}
/**
* 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 MXS_AUTH_STATE_HANDSHAKE_FAILED:
case MXS_AUTH_STATE_FAILED:
if (dcb->session->state != SESSION_STATE_STOPPING)
{
MXS_ERROR("Unable to write to backend '%s' due to "
"%s failure. Server in state %s.",
dcb->server->name,
backend_protocol->protocol_auth_state == MXS_AUTH_STATE_HANDSHAKE_FAILED ?
"handshake" : "authentication",
STRSRVSTATUS(dcb->server));
}
gwbuf_free(queue);
rc = 0;
break;
case MXS_AUTH_STATE_COMPLETE:
{
uint8_t* ptr = GWBUF_DATA(queue);
mxs_mysql_cmd_t cmd = static_cast<mxs_mysql_cmd_t>(mxs_mysql_get_command(queue));
MXS_DEBUG("write to dcb %p fd %d protocol state %s.",
dcb, dcb->fd, STRPROTOCOLSTATE(backend_protocol->protocol_auth_state));
prepare_for_write(dcb, queue);
if (cmd == MXS_COM_QUIT && dcb->server->persistpoolmax)
{
/** We need to keep the pooled connections alive so we just ignore the COM_QUIT packet */
gwbuf_free(queue);
rc = 1;
}
else
{
if (GWBUF_IS_IGNORABLE(queue))
{
/** The response to this command should be ignored */
backend_protocol->ignore_replies++;
ss_dassert(backend_protocol->ignore_replies > 0);
}
/** Write to backend */
rc = dcb_write(dcb, queue);
}
}
break;
default:
{
MXS_DEBUG("delayed write to dcb %p fd %d protocol state %s.",
dcb, dcb->fd, STRPROTOCOLSTATE(backend_protocol->protocol_auth_state));
/** Store data until authentication is complete */
prepare_for_write(dcb, queue);
backend_set_delayqueue(dcb, queue);
rc = 1;
}
break;
}
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)
{
CHK_DCB(dcb);
MXS_SESSION *session = dcb->session;
CHK_SESSION(session);
if (session->state == SESSION_STATE_DUMMY)
{
if (dcb->persistentstart == 0)
{
/** Not a persistent connection, something is wrong. */
MXS_ERROR("EPOLLERR event on a non-persistent DCB with no session. "
"Closing connection.");
}
dcb_close(dcb);
}
else if (dcb->state != DCB_STATE_POLLING || session->state != SESSION_STATE_ROUTER_READY)
{
int error;
int len = sizeof(error);
if (getsockopt(dcb->fd, SOL_SOCKET, SO_ERROR, &error, (socklen_t *) & len) == 0 && error != 0)
{
if (dcb->state != DCB_STATE_POLLING)
{
MXS_ERROR("DCB in state %s got error '%s'.", STRDCBSTATE(dcb->state),
mxs_strerror(errno));
}
else
{
MXS_ERROR("Error '%s' in session that is not ready for routing.",
mxs_strerror(errno));
}
}
}
else
{
do_handle_error(dcb, ERRACT_NEW_CONNECTION, "Lost connection to backend server.");
}
return 1;
}
/**
* 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)
{
CHK_DCB(dcb);
MXS_SESSION *session = dcb->session;
CHK_SESSION(session);
if (dcb->persistentstart)
{
dcb->dcb_errhandle_called = true;
}
else if (session->state != SESSION_STATE_ROUTER_READY)
{
int error;
int len = sizeof(error);
if (getsockopt(dcb->fd, SOL_SOCKET, SO_ERROR, &error, (socklen_t *) & len) == 0)
{
if (error != 0 && session->state != SESSION_STATE_STOPPING)
{
MXS_ERROR("Hangup in session that is not ready for routing, "
"Error reported is '%s'.",
mxs_strerror(errno));
}
}
}
else
{
do_handle_error(dcb, ERRACT_NEW_CONNECTION, "Lost connection to backend server.");
}
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)
{
CHK_DCB(dcb);
ss_dassert(dcb->session);
/** Send COM_QUIT to the backend being closed */
GWBUF* quitbuf = mysql_create_com_quit(NULL, 0);
mysql_send_com_quit(dcb, 0, quitbuf);
/** Free protocol data */
mysql_protocol_done(dcb);
MXS_SESSION* session = dcb->session;
CHK_SESSION(session);
/**
* If session state is SESSION_STATE_STOPPING, start closing client session.
* Otherwise only this backend connection is closed.
*/
if (session->client_dcb &&
session->state == SESSION_STATE_STOPPING &&
session->client_dcb->state == DCB_STATE_POLLING)
{
poll_fake_hangup_event(session->client_dcb);
}
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)
{
/* Append data */
dcb->delayq = gwbuf_append(dcb->delayq, queue);
}
/**
* 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 *buffer)
{
ss_dassert(buffer);
ss_dassert(dcb->persistentstart == 0);
ss_dassert(!dcb->was_persistent);
if (MYSQL_IS_CHANGE_USER(((uint8_t *)GWBUF_DATA(buffer))))
{
/** Recreate the COM_CHANGE_USER packet with the scramble the backend sent to us */
MYSQL_session mses;
gw_get_shared_session_auth_info(dcb, &mses);
gwbuf_free(buffer);
buffer = gw_create_change_user_packet(&mses, static_cast<MySQLProtocol*>(dcb->protocol));
}
int rc = 1;
if (MYSQL_IS_COM_QUIT(((uint8_t*)GWBUF_DATA(buffer))) && dcb->server->persistpoolmax)
{
/** We need to keep the pooled connections alive so we just ignore the COM_QUIT packet */
gwbuf_free(buffer);
rc = 1;
}
else
{
rc = dcb_write(dcb, buffer);
}
if (rc == 0)
{
do_handle_error(dcb, ERRACT_NEW_CONNECTION, "Lost connection to backend server.");
}
return rc;
}
/**
* This routine handles the COM_CHANGE_USER command
*
* TODO: Move this into the authenticators
*
* @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,
MXS_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_dcb->data;
backend_protocol = static_cast<MySQLProtocol*>(backend->protocol);
client_protocol = static_cast<MySQLProtocol*>(in_session->client_dcb->protocol);
/* now get the user, after 4 bytes header and 1 byte command */
client_auth_packet += 5;
size_t len = strlen((char *)client_auth_packet);
if (len > MYSQL_USER_MAXLEN)
{
MXS_ERROR("Client sent user name \"%s\",which is %lu characters long, "
"while a maximum length of %d is allowed. Cutting trailing "
"characters.", (char*)client_auth_packet, len, MYSQL_USER_MAXLEN);
}
strncpy(username, (char *)client_auth_packet, MYSQL_USER_MAXLEN);
username[MYSQL_USER_MAXLEN] = 0;
client_auth_packet += (len + 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 *)MXS_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 */
len = strlen((char *)client_auth_packet);
if (len > MYSQL_DATABASE_MAXLEN)
{
MXS_ERROR("Client sent database name \"%s\", which is %lu characters long, "
"while a maximum length of %d is allowed. Cutting trailing "
"characters.", (char*)client_auth_packet, len, MYSQL_DATABASE_MAXLEN);
}
strncpy(database, (char *)client_auth_packet, MYSQL_DATABASE_MAXLEN);
database[MYSQL_DATABASE_MAXLEN] = 0;
client_auth_packet += (len + 1);
if (*client_auth_packet)
{
memcpy(&backend_protocol->charset, client_auth_packet, sizeof(int));
}
/* save current_database name */
strcpy(current_database, current_session->db);
/*
* 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.
*/
*current_session->db = 0;
/*
* Decode the token and check the password.
* Note: if auth_token_len == 0 && auth_token == NULL, user is without password
*/
DCB *dcb = backend->session->client_dcb;
if (dcb->authfunc.reauthenticate == NULL)
{
/** Authenticator does not support reauthentication */
rv = 0;
goto retblock;
}
auth_ret = dcb->authfunc.reauthenticate(dcb, username,
auth_token, auth_token_len,
client_protocol->scramble,
sizeof(client_protocol->scramble),
client_sha1, sizeof(client_sha1));
strcpy(current_session->db, current_database);
if (auth_ret != 0)
{
if (service_refresh_users(backend->session->client_dcb->service) == 0)
{
/* Try authentication again with new repository data */
/* Note: if no auth client authentication will fail */
*current_session->db = 0;
auth_ret = dcb->authfunc.reauthenticate(dcb, username,
auth_token, auth_token_len,
client_protocol->scramble,
sizeof(client_protocol->scramble),
client_sha1, sizeof(client_sha1));
strcpy(current_session->db, current_database);
}
}
MXS_FREE(auth_token);
if (auth_ret != 0)
{
bool password_set = false;
char *message = NULL;
if (auth_token_len > 0)
{
// If the length of the authentication token is non-0, then
// it means that the client provided a password.
password_set = true;
}
/**
* 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_dcb->remote,
password_set,
NULL,
auth_ret);
if (message == NULL)
{
MXS_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,
MXS_COM_CHANGE_USER);
modutil_reply_auth_error(backend, message, 0);
rv = 1;
}
else
{
/** This assumes that authentication will succeed. If authentication fails,
* the internal session will represent the wrong user. This is wrong and
* a check whether the COM_CHANGE_USER succeeded should be done in the
* backend protocol reply handling.
*
* For the time being, it is simpler to assume a COM_CHANGE_USER will always
* succeed if the authentication in MaxScale is successful. In practice this
* might not be true but these cases are handled by the router modules
* and the servers that fail to execute the COM_CHANGE_USER are discarded. */
strcpy(current_session->user, username);
strcpy(current_session->db, database);
memcpy(current_session->client_sha1, client_sha1, sizeof(current_session->client_sha1));
rv = gw_send_change_user_to_backend(database, username, client_sha1, backend_protocol);
}
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 */
int nbytes_left = 0; /*< nbytes to be read for the packet */
MySQLProtocol* p;
GWBUF* outbuf = NULL;
int initial_packets = npackets_left;
int initial_bytes = nbytes_left;
/** Get command which was stored in gw_MySQLWrite_backend */
p = DCB_PROTOCOL(dcb, MySQLProtocol);
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)
{
mxs_mysql_cmd_t srvcmd;
bool succp;
srvcmd = protocol_get_srv_command(p, false);
MXS_DEBUG("Read command %s for DCB %p fd %d.", STRPACKETTYPE(srvcmd), dcb, dcb->fd);
/**
* Read values from protocol structure, fails if values are
* uninitialized.
*/
if (npackets_left == 0)
{
size_t bytes; // nbytes_left is int, but the type must be size_t.
succp = protocol_get_response_status(p, &npackets_left, &bytes);
nbytes_left = bytes;
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, &bytes);
nbytes_left = bytes;
}
initial_packets = npackets_left;
initial_bytes = nbytes_left;
}
/** Only session commands with responses should be processed */
ss_dassert(npackets_left > 0);
/** Read incomplete packet. */
if ((int)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 ((int)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;
}
/**
* Buffer contains more data than we need. Split the complete packet and
* the extra data into two separate buffers.
*/
else
{
ss_dassert((int)nbytes_left < nbytes_to_process);
ss_dassert(nbytes_left > 0);
ss_dassert(npackets_left > 0);
outbuf = gwbuf_append(outbuf, gwbuf_split(readbuf, nbytes_left));
nbytes_to_process -= nbytes_left;
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);
/** Ignore the rest of the response */
nbytes_to_process = 0;
}
/** Read next packet */
else
{
uint8_t* data;
/** Read next packet length if there is at least
* three bytes left. If there is less than three
* bytes in the buffer or it is NULL, we need to
wait for more data from the backend server.*/
if (*readbuf == NULL || gwbuf_length(*readbuf) < 3)
{
MXS_DEBUG("[%s] Read %d packets. Waiting for %d more "
"packets for a total of %d packets.", __FUNCTION__,
initial_packets - npackets_left,
npackets_left, initial_packets);
/** Store the already read data into the readqueue of the DCB
* and restore the response status to the initial number of packets */
dcb_readq_prepend(dcb, outbuf);
protocol_set_response_status(p, initial_packets, initial_bytes);
return NULL;
}
uint8_t packet_len[3];
gwbuf_copy_data(*readbuf, 0, 3, packet_len);
nbytes_left = gw_mysql_get_byte3(packet_len) + 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;
size_t nbytes_left;
MySQLProtocol* p;
bool succp;
p = DCB_PROTOCOL(dcb, MySQLProtocol);
CHK_PROTOCOL(p);
protocol_get_response_status(p, &npackets_left, &nbytes_left);
if (npackets_left == 0)
{
succp = true;
}
else
{
succp = false;
}
return succp;
}
/**
* Create COM_CHANGE_USER packet and store it to GWBUF
*
* @param mses MySQL session
* @param protocol protocol structure of the backend
*
* @return GWBUF buffer consisting of COM_CHANGE_USER packet
*
* @note the function doesn't fail
*/
static GWBUF *
gw_create_change_user_packet(MYSQL_session* mses,
MySQLProtocol* protocol)
{
char* db;
char* user;
uint8_t* pwd;
GWBUF* buffer;
uint8_t* payload = NULL;
uint8_t* payload_start = NULL;
long bytes;
char dbpass[MYSQL_USER_MAXLEN + 1] = "";
char* curr_db = NULL;
uint8_t* curr_passwd = NULL;
unsigned int charset;
db = mses->db;
user = mses->user;
pwd = mses->client_sha1;
if (strlen(db) > 0)
{
curr_db = db;
}
if (memcmp(pwd, null_client_sha1, MYSQL_SCRAMBLE_LEN))
{
curr_passwd = pwd;
}
/* get charset the client sent and use it for connection auth */
charset = protocol->charset;
/**
* Protocol MySQL COM_CHANGE_USER for CLIENT_PROTOCOL_41
* 1 byte COMMAND
*/
bytes = 1;
/** add the user and a terminating char */
bytes += strlen(user);
bytes++;
/**
* next will be + 1 (scramble_len) + 20 (fixed_scramble) +
* (db + NULL term) + 2 bytes charset
*/
if (curr_passwd != NULL)
{
bytes += GW_MYSQL_SCRAMBLE_SIZE;
}
/** 1 byte for scramble_len */
bytes++;
/** db name and terminating char */
if (curr_db != NULL)
{
bytes += strlen(curr_db);
}
bytes++;
/** the charset */
bytes += 2;
bytes += strlen("mysql_native_password");
bytes++;
/** the packet header */
bytes += 4;
buffer = gwbuf_alloc(bytes);
/**
* Set correct type to GWBUF so that it will be handled like session
* commands
*/
buffer->gwbuf_type = GWBUF_TYPE_SESCMD;
payload = GWBUF_DATA(buffer);
memset(payload, '\0', bytes);
payload_start = payload;
/** set packet number to 0 */
payload[3] = 0x00;
payload += 4;
/** set the command COM_CHANGE_USER 0x11 */
payload[0] = 0x11;
payload++;
memcpy(payload, user, strlen(user));
payload += strlen(user);
payload++;
if (curr_passwd != NULL)
{
uint8_t hash1[GW_MYSQL_SCRAMBLE_SIZE] = "";
uint8_t hash2[GW_MYSQL_SCRAMBLE_SIZE] = "";
uint8_t new_sha[GW_MYSQL_SCRAMBLE_SIZE] = "";
uint8_t client_scramble[GW_MYSQL_SCRAMBLE_SIZE];
/** hash1 is the function input, SHA1(real_password) */
memcpy(hash1, pwd, GW_MYSQL_SCRAMBLE_SIZE);
/**
* hash2 is the SHA1(input data), where
* input_data = SHA1(real_password)
*/
gw_sha1_str(hash1, GW_MYSQL_SCRAMBLE_SIZE, hash2);
/** dbpass is the HEX form of SHA1(SHA1(real_password)) */
gw_bin2hex(dbpass, hash2, GW_MYSQL_SCRAMBLE_SIZE);
/** new_sha is the SHA1(CONCAT(scramble, hash2) */
gw_sha1_2_str(protocol->scramble,
GW_MYSQL_SCRAMBLE_SIZE,
hash2,
GW_MYSQL_SCRAMBLE_SIZE,
new_sha);
/** compute the xor in client_scramble */
gw_str_xor(client_scramble,
new_sha, hash1,
GW_MYSQL_SCRAMBLE_SIZE);
/** set the auth-length */
*payload = GW_MYSQL_SCRAMBLE_SIZE;
payload++;
/**
* copy the 20 bytes scramble data after
* packet_buffer + 36 + user + NULL + 1 (byte of auth-length)
*/
memcpy(payload, client_scramble, GW_MYSQL_SCRAMBLE_SIZE);
payload += GW_MYSQL_SCRAMBLE_SIZE;
}
else
{
/** skip the auth-length and leave the byte as NULL */
payload++;
}
/** if the db is not NULL append it */
if (curr_db != NULL)
{
memcpy(payload, curr_db, strlen(curr_db));
payload += strlen(curr_db);
}
payload++;
/** set the charset, 2 bytes */
*payload = charset;
payload++;
*payload = '\x00';
payload++;
memcpy(payload, "mysql_native_password", strlen("mysql_native_password"));
/* Following needed if more to be added */
/* payload += strlen("mysql_native_password"); */
/** put here the paylod size: bytes to write - 4 bytes packet header */
gw_mysql_set_byte3(payload_start, (bytes - 4));
return buffer;
}
/**
* Write a MySQL CHANGE_USER packet to backend server
*
* @param conn MySQL protocol structure
* @param dbname The selected database
* @param user The selected user
* @param passwd The SHA1(real_password)
* @return 1 on success, 0 on failure
*/
static int
gw_send_change_user_to_backend(char *dbname,
char *user,
uint8_t *passwd,
MySQLProtocol *conn)
{
GWBUF *buffer;
int rc;
MYSQL_session* mses;
mses = (MYSQL_session*)conn->owner_dcb->session->client_dcb->data;
buffer = gw_create_change_user_packet(mses, conn);
rc = conn->owner_dcb->func.write(conn->owner_dcb, buffer);
if (rc != 0)
{
conn->changing_user = true;
rc = 1;
}
return rc;
}
/* Send proxy protocol header. See
* http://www.haproxy.org/download/1.8/doc/proxy-protocol.txt
* for more information. Currently only supports the text version (v1) of
* the protocol. Binary version may be added when the feature has been confirmed
* to work.
*
* @param backend_dcb The target dcb.
*/
static void gw_send_proxy_protocol_header(DCB *backend_dcb)
{
// TODO: Add support for chained proxies. Requires reading the client header.
const DCB *client_dcb = backend_dcb->session->client_dcb;
const int client_fd = client_dcb->fd;
const sa_family_t family = client_dcb->ip.ss_family;
const char *family_str = NULL;
struct sockaddr_storage sa_peer;
struct sockaddr_storage sa_local;
socklen_t sa_peer_len = sizeof(sa_peer);
socklen_t sa_local_len = sizeof(sa_local);
/* Fill in peer's socket address. */
if (getpeername(client_fd, (struct sockaddr *)&sa_peer, &sa_peer_len) == -1)
{
MXS_ERROR("'%s' failed on file descriptor '%d'.", "getpeername()", client_fd);
return;
}
/* Fill in this socket's local address. */
if (getsockname(client_fd, (struct sockaddr *)&sa_local, &sa_local_len) == -1)
{
MXS_ERROR("'%s' failed on file descriptor '%d'.", "getsockname()", client_fd);
return;
}
ss_dassert(sa_peer.ss_family == sa_local.ss_family);
char peer_ip[INET6_ADDRSTRLEN];
char maxscale_ip[INET6_ADDRSTRLEN];
in_port_t peer_port;
in_port_t maxscale_port;
if (!get_ip_string_and_port(&sa_peer, peer_ip, sizeof(peer_ip), &peer_port) ||
!get_ip_string_and_port(&sa_local, maxscale_ip, sizeof(maxscale_ip), &maxscale_port))
{
MXS_ERROR("Could not convert network address to string form.");
return;
}
switch (family)
{
case AF_INET:
family_str = "TCP4";
break;
case AF_INET6:
family_str = "TCP6";
break;
default:
family_str = "UNKNOWN";
break;
}
int rval;
char proxy_header[108]; // 108 is the worst-case length
if (family == AF_INET || family == AF_INET6)
{
rval = snprintf(proxy_header, sizeof(proxy_header), "PROXY %s %s %s %d %d\r\n",
family_str, peer_ip, maxscale_ip, peer_port, maxscale_port);
}
else
{
rval = snprintf(proxy_header, sizeof(proxy_header), "PROXY %s\r\n", family_str);
}
if (rval < 0 || rval >= (int)sizeof(proxy_header))
{
MXS_ERROR("Proxy header printing error, produced '%s'.", proxy_header);
return;
}
GWBUF *headerbuf = gwbuf_alloc_and_load(strlen(proxy_header), proxy_header);
if (headerbuf)
{
MXS_INFO("Sending proxy-protocol header '%s' to backend %s.", proxy_header,
backend_dcb->server->name);
if (!dcb_write(backend_dcb, headerbuf))
{
gwbuf_free(headerbuf);
}
}
return;
}
/* Read IP and port from socket address structure, return IP as string and port
* as host byte order integer.
*
* @param sa A sockaddr_storage containing either an IPv4 or v6 address
* @param ip Pointer to output array
* @param iplen Output array length
* @param port_out Port number output
*/
static bool get_ip_string_and_port(struct sockaddr_storage *sa,
char *ip, int iplen, in_port_t *port_out)
{
bool success = false;
in_port_t port;
switch (sa->ss_family)
{
case AF_INET:
{
struct sockaddr_in *sock_info = (struct sockaddr_in *)sa;
struct in_addr *addr = &(sock_info->sin_addr);
success = (inet_ntop(AF_INET, addr, ip, iplen) != NULL);
port = ntohs(sock_info->sin_port);
}
break;
case AF_INET6:
{
struct sockaddr_in6 *sock_info = (struct sockaddr_in6 *)sa;
struct in6_addr *addr = &(sock_info->sin6_addr);
success = (inet_ntop(AF_INET6, addr, ip, iplen) != NULL);
port = ntohs(sock_info->sin6_port);
}
break;
}
if (success)
{
*port_out = port;
}
return success;
}
static bool gw_connection_established(DCB* dcb)
{
MySQLProtocol *proto = (MySQLProtocol*)dcb->protocol;
return
proto->protocol_auth_state == MXS_AUTH_STATE_COMPLETE &&
(proto->ignore_replies == 0)
&& !proto->stored_query;
}
json_t* gw_json_diagnostics(DCB* dcb)
{
MySQLProtocol* proto = static_cast<MySQLProtocol*>(dcb->protocol);
json_t* obj = json_object();
json_object_set_new(obj, "connection_id", json_integer(proto->thread_id));
return obj;
}
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