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78bb7cc600a256a0ece8844745cbcd91a8f730b8
mariadb/sql/sql_connect.cc
Tatjana Azundris Nuernberg 8248f5f71a manual up-merge of Bug#11755281
2012-01-02 06:50:05 +00:00

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/*
Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
This program 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 of the License.
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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
Functions to autenticate and handle reqests for a connection
*/
#include "my_global.h"
#include "sql_priv.h"
#ifndef __WIN__
#include <netdb.h> // getservbyname, servent
#endif
#include "sql_audit.h"
#include "sql_connect.h"
#include "my_global.h"
#include "probes_mysql.h"
#include "unireg.h" // REQUIRED: for other includes
#include "sql_parse.h" // sql_command_flags,
// execute_init_command,
// do_command
#include "sql_db.h" // mysql_change_db
#include "hostname.h" // inc_host_errors, ip_to_hostname,
// reset_host_errors
#include "sql_acl.h" // acl_getroot, NO_ACCESS, SUPER_ACL
#include "sql_callback.h"
#if defined(HAVE_OPENSSL) && !defined(EMBEDDED_LIBRARY)
/*
Without SSL the handshake consists of one packet. This packet
has both client capabilites and scrambled password.
With SSL the handshake might consist of two packets. If the first
packet (client capabilities) has CLIENT_SSL flag set, we have to
switch to SSL and read the second packet. The scrambled password
is in the second packet and client_capabilites field will be ignored.
Maybe it is better to accept flags other than CLIENT_SSL from the
second packet?
*/
#define SSL_HANDSHAKE_SIZE 2
#define NORMAL_HANDSHAKE_SIZE 6
#define MIN_HANDSHAKE_SIZE 2
#else
#define MIN_HANDSHAKE_SIZE 6
#endif /* HAVE_OPENSSL && !EMBEDDED_LIBRARY */
/*
Get structure for logging connection data for the current user
*/
#ifndef NO_EMBEDDED_ACCESS_CHECKS
static HASH hash_user_connections;
int get_or_create_user_conn(THD *thd, const char *user,
const char *host,
const USER_RESOURCES *mqh)
{
int return_val= 0;
size_t temp_len, user_len;
char temp_user[USER_HOST_BUFF_SIZE];
struct user_conn *uc;
DBUG_ASSERT(user != 0);
DBUG_ASSERT(host != 0);
user_len= strlen(user);
temp_len= (strmov(strmov(temp_user, user)+1, host) - temp_user)+1;
mysql_mutex_lock(&LOCK_user_conn);
if (!(uc = (struct user_conn *) my_hash_search(&hash_user_connections,
(uchar*) temp_user, temp_len)))
{
/* First connection for user; Create a user connection object */
if (!(uc= ((struct user_conn*)
my_malloc(sizeof(struct user_conn) + temp_len+1,
MYF(MY_WME)))))
{
/* MY_WME ensures an error is set in THD. */
return_val= 1;
goto end;
}
uc->user=(char*) (uc+1);
memcpy(uc->user,temp_user,temp_len+1);
uc->host= uc->user + user_len + 1;
uc->len= temp_len;
uc->connections= uc->questions= uc->updates= uc->conn_per_hour= 0;
uc->user_resources= *mqh;
uc->reset_utime= thd->thr_create_utime;
if (my_hash_insert(&hash_user_connections, (uchar*) uc))
{
/* The only possible error is out of memory, MY_WME sets an error. */
my_free(uc);
return_val= 1;
goto end;
}
}
thd->user_connect=uc;
uc->connections++;
end:
mysql_mutex_unlock(&LOCK_user_conn);
return return_val;
}
/*
check if user has already too many connections
SYNOPSIS
check_for_max_user_connections()
thd Thread handle
uc User connect object
NOTES
If check fails, we decrease user connection count, which means one
shouldn't call decrease_user_connections() after this function.
RETURN
0 ok
1 error
*/
int check_for_max_user_connections(THD *thd, USER_CONN *uc)
{
int error=0;
DBUG_ENTER("check_for_max_user_connections");
mysql_mutex_lock(&LOCK_user_conn);
if (global_system_variables.max_user_connections &&
!uc->user_resources.user_conn &&
global_system_variables.max_user_connections < (uint) uc->connections)
{
my_error(ER_TOO_MANY_USER_CONNECTIONS, MYF(0), uc->user);
error=1;
goto end;
}
time_out_user_resource_limits(thd, uc);
if (uc->user_resources.user_conn &&
uc->user_resources.user_conn < uc->connections)
{
my_error(ER_USER_LIMIT_REACHED, MYF(0), uc->user,
"max_user_connections",
(long) uc->user_resources.user_conn);
error= 1;
goto end;
}
if (uc->user_resources.conn_per_hour &&
uc->user_resources.conn_per_hour <= uc->conn_per_hour)
{
my_error(ER_USER_LIMIT_REACHED, MYF(0), uc->user,
"max_connections_per_hour",
(long) uc->user_resources.conn_per_hour);
error=1;
goto end;
}
uc->conn_per_hour++;
end:
if (error)
{
uc->connections--; // no need for decrease_user_connections() here
/*
The thread may returned back to the pool and assigned to a user
that doesn't have a limit. Ensure the user is not using resources
of someone else.
*/
thd->user_connect= NULL;
}
mysql_mutex_unlock(&LOCK_user_conn);
DBUG_RETURN(error);
}
/*
Decrease user connection count
SYNOPSIS
decrease_user_connections()
uc User connection object
NOTES
If there is a n user connection object for a connection
(which only happens if 'max_user_connections' is defined or
if someone has created a resource grant for a user), then
the connection count is always incremented on connect.
The user connect object is not freed if some users has
'max connections per hour' defined as we need to be able to hold
count over the lifetime of the connection.
*/
void decrease_user_connections(USER_CONN *uc)
{
DBUG_ENTER("decrease_user_connections");
mysql_mutex_lock(&LOCK_user_conn);
DBUG_ASSERT(uc->connections);
if (!--uc->connections && !mqh_used)
{
/* Last connection for user; Delete it */
(void) my_hash_delete(&hash_user_connections,(uchar*) uc);
}
mysql_mutex_unlock(&LOCK_user_conn);
DBUG_VOID_RETURN;
}
/*
Reset per-hour user resource limits when it has been more than
an hour since they were last checked
SYNOPSIS:
time_out_user_resource_limits()
thd Thread handler
uc User connection details
NOTE:
This assumes that the LOCK_user_conn mutex has been acquired, so it is
safe to test and modify members of the USER_CONN structure.
*/
void time_out_user_resource_limits(THD *thd, USER_CONN *uc)
{
ulonglong check_time= thd->start_utime;
DBUG_ENTER("time_out_user_resource_limits");
/* If more than a hour since last check, reset resource checking */
if (check_time - uc->reset_utime >= LL(3600000000))
{
uc->questions=1;
uc->updates=0;
uc->conn_per_hour=0;
uc->reset_utime= check_time;
}
DBUG_VOID_RETURN;
}
/*
Check if maximum queries per hour limit has been reached
returns 0 if OK.
*/
bool check_mqh(THD *thd, uint check_command)
{
bool error= 0;
USER_CONN *uc=thd->user_connect;
DBUG_ENTER("check_mqh");
DBUG_ASSERT(uc != 0);
mysql_mutex_lock(&LOCK_user_conn);
time_out_user_resource_limits(thd, uc);
/* Check that we have not done too many questions / hour */
if (uc->user_resources.questions &&
uc->questions++ >= uc->user_resources.questions)
{
my_error(ER_USER_LIMIT_REACHED, MYF(0), uc->user, "max_questions",
(long) uc->user_resources.questions);
error=1;
goto end;
}
if (check_command < (uint) SQLCOM_END)
{
/* Check that we have not done too many updates / hour */
if (uc->user_resources.updates &&
(sql_command_flags[check_command] & CF_CHANGES_DATA) &&
uc->updates++ >= uc->user_resources.updates)
{
my_error(ER_USER_LIMIT_REACHED, MYF(0), uc->user, "max_updates",
(long) uc->user_resources.updates);
error=1;
goto end;
}
}
end:
mysql_mutex_unlock(&LOCK_user_conn);
DBUG_RETURN(error);
}
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
/*
Check for maximum allowable user connections, if the mysqld server is
started with corresponding variable that is greater then 0.
*/
extern "C" uchar *get_key_conn(user_conn *buff, size_t *length,
my_bool not_used __attribute__((unused)))
{
*length= buff->len;
return (uchar*) buff->user;
}
extern "C" void free_user(struct user_conn *uc)
{
my_free(uc);
}
void init_max_user_conn(void)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
(void)
my_hash_init(&hash_user_connections,system_charset_info,max_connections,
0,0, (my_hash_get_key) get_key_conn,
(my_hash_free_key) free_user, 0);
#endif
}
void free_max_user_conn(void)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
my_hash_free(&hash_user_connections);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
}
void reset_mqh(LEX_USER *lu, bool get_them= 0)
{
#ifndef NO_EMBEDDED_ACCESS_CHECKS
mysql_mutex_lock(&LOCK_user_conn);
if (lu) // for GRANT
{
USER_CONN *uc;
uint temp_len=lu->user.length+lu->host.length+2;
char temp_user[USER_HOST_BUFF_SIZE];
memcpy(temp_user,lu->user.str,lu->user.length);
memcpy(temp_user+lu->user.length+1,lu->host.str,lu->host.length);
temp_user[lu->user.length]='\0'; temp_user[temp_len-1]=0;
if ((uc = (struct user_conn *) my_hash_search(&hash_user_connections,
(uchar*) temp_user,
temp_len)))
{
uc->questions=0;
get_mqh(temp_user,&temp_user[lu->user.length+1],uc);
uc->updates=0;
uc->conn_per_hour=0;
}
}
else
{
/* for FLUSH PRIVILEGES and FLUSH USER_RESOURCES */
for (uint idx=0;idx < hash_user_connections.records; idx++)
{
USER_CONN *uc=(struct user_conn *)
my_hash_element(&hash_user_connections, idx);
if (get_them)
get_mqh(uc->user,uc->host,uc);
uc->questions=0;
uc->updates=0;
uc->conn_per_hour=0;
}
}
mysql_mutex_unlock(&LOCK_user_conn);
#endif /* NO_EMBEDDED_ACCESS_CHECKS */
}
/**
Set thread character set variables from the given ID
@param thd thread handle
@param cs_number character set and collation ID
@retval 0 OK; character_set_client, collation_connection and
character_set_results are set to the new value,
or to the default global values.
@retval 1 error, e.g. the given ID is not supported by parser.
Corresponding SQL error is sent.
*/
bool thd_init_client_charset(THD *thd, uint cs_number)
{
CHARSET_INFO *cs;
/*
Use server character set and collation if
- opt_character_set_client_handshake is not set
- client has not specified a character set
- client character set is the same as the servers
- client character set doesn't exists in server
*/
if (!opt_character_set_client_handshake ||
!(cs= get_charset(cs_number, MYF(0))) ||
!my_strcasecmp(&my_charset_latin1,
global_system_variables.character_set_client->name,
cs->name))
{
thd->variables.character_set_client=
global_system_variables.character_set_client;
thd->variables.collation_connection=
global_system_variables.collation_connection;
thd->variables.character_set_results=
global_system_variables.character_set_results;
}
else
{
if (!is_supported_parser_charset(cs))
{
/* Disallow non-supported parser character sets: UCS2, UTF16, UTF32 */
my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), "character_set_client",
cs->csname);
return true;
}
thd->variables.character_set_results=
thd->variables.collation_connection=
thd->variables.character_set_client= cs;
}
return false;
}
/*
Initialize connection threads
*/
bool init_new_connection_handler_thread()
{
pthread_detach_this_thread();
if (my_thread_init())
return 1;
return 0;
}
#ifndef EMBEDDED_LIBRARY
/*
Perform handshake, authorize client and update thd ACL variables.
SYNOPSIS
check_connection()
thd thread handle
RETURN
0 success, thd is updated.
1 error
*/
static int check_connection(THD *thd)
{
uint connect_errors= 0;
NET *net= &thd->net;
DBUG_PRINT("info",
("New connection received on %s", vio_description(net->vio)));
#ifdef SIGNAL_WITH_VIO_CLOSE
thd->set_active_vio(net->vio);
#endif
if (!thd->main_security_ctx.host) // If TCP/IP connection
{
char ip[NI_MAXHOST];
if (vio_peer_addr(net->vio, ip, &thd->peer_port, NI_MAXHOST))
{
my_error(ER_BAD_HOST_ERROR, MYF(0));
return 1;
}
if (!(thd->main_security_ctx.ip= my_strdup(ip,MYF(MY_WME))))
return 1; /* The error is set by my_strdup(). */
thd->main_security_ctx.host_or_ip= thd->main_security_ctx.ip;
if (!(specialflag & SPECIAL_NO_RESOLVE))
{
if (ip_to_hostname(&net->vio->remote, thd->main_security_ctx.ip,
&thd->main_security_ctx.host, &connect_errors))
{
my_error(ER_BAD_HOST_ERROR, MYF(0));
return 1;
}
/* Cut very long hostnames to avoid possible overflows */
if (thd->main_security_ctx.host)
{
if (thd->main_security_ctx.host != my_localhost)
thd->main_security_ctx.host[min(strlen(thd->main_security_ctx.host),
HOSTNAME_LENGTH)]= 0;
thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;
}
if (connect_errors > max_connect_errors)
{
my_error(ER_HOST_IS_BLOCKED, MYF(0), thd->main_security_ctx.host_or_ip);
return 1;
}
}
DBUG_PRINT("info",("Host: %s ip: %s",
(thd->main_security_ctx.host ?
thd->main_security_ctx.host : "unknown host"),
(thd->main_security_ctx.ip ?
thd->main_security_ctx.ip : "unknown ip")));
if (acl_check_host(thd->main_security_ctx.host, thd->main_security_ctx.ip))
{
my_error(ER_HOST_NOT_PRIVILEGED, MYF(0),
thd->main_security_ctx.host_or_ip);
return 1;
}
}
else /* Hostname given means that the connection was on a socket */
{
DBUG_PRINT("info",("Host: %s", thd->main_security_ctx.host));
thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;
thd->main_security_ctx.ip= 0;
/* Reset sin_addr */
bzero((char*) &net->vio->remote, sizeof(net->vio->remote));
}
vio_keepalive(net->vio, TRUE);
if (thd->packet.alloc(thd->variables.net_buffer_length))
return 1; /* The error is set by alloc(). */
return acl_authenticate(thd, connect_errors, 0);
}
/*
Setup thread to be used with the current thread
SYNOPSIS
bool setup_connection_thread_globals()
thd Thread/connection handler
RETURN
0 ok
1 Error (out of memory)
In this case we will close the connection and increment status
*/
bool setup_connection_thread_globals(THD *thd)
{
if (thd->store_globals())
{
close_connection(thd, ER_OUT_OF_RESOURCES);
statistic_increment(aborted_connects,&LOCK_status);
MYSQL_CALLBACK(thread_scheduler, end_thread, (thd, 0));
return 1; // Error
}
return 0;
}
/*
Autenticate user, with error reporting
SYNOPSIS
login_connection()
thd Thread handler
NOTES
Connection is not closed in case of errors
RETURN
0 ok
1 error
*/
bool login_connection(THD *thd)
{
NET *net= &thd->net;
int error;
DBUG_ENTER("login_connection");
DBUG_PRINT("info", ("login_connection called by thread %lu",
thd->thread_id));
/* Use "connect_timeout" value during connection phase */
my_net_set_read_timeout(net, connect_timeout);
my_net_set_write_timeout(net, connect_timeout);
error= check_connection(thd);
thd->protocol->end_statement();
if (error)
{ // Wrong permissions
#ifdef _WIN32
if (vio_type(net->vio) == VIO_TYPE_NAMEDPIPE)
my_sleep(1000); /* must wait after eof() */
#endif
statistic_increment(aborted_connects,&LOCK_status);
DBUG_RETURN(1);
}
/* Connect completed, set read/write timeouts back to default */
my_net_set_read_timeout(net, thd->variables.net_read_timeout);
my_net_set_write_timeout(net, thd->variables.net_write_timeout);
DBUG_RETURN(0);
}
/*
Close an established connection
NOTES
This mainly updates status variables
*/
void end_connection(THD *thd)
{
NET *net= &thd->net;
plugin_thdvar_cleanup(thd);
if (thd->user_connect)
{
decrease_user_connections(thd->user_connect);
/*
The thread may returned back to the pool and assigned to a user
that doesn't have a limit. Ensure the user is not using resources
of someone else.
*/
thd->user_connect= NULL;
}
if (thd->killed || (net->error && net->vio != 0))
{
statistic_increment(aborted_threads,&LOCK_status);
}
if (net->error && net->vio != 0)
{
if (!thd->killed && thd->variables.log_warnings > 1)
{
Security_context *sctx= thd->security_ctx;
sql_print_warning(ER(ER_NEW_ABORTING_CONNECTION),
thd->thread_id,(thd->db ? thd->db : "unconnected"),
sctx->user ? sctx->user : "unauthenticated",
sctx->host_or_ip,
(thd->stmt_da->is_error() ? thd->stmt_da->message() :
ER(ER_UNKNOWN_ERROR)));
}
}
}
/*
Initialize THD to handle queries
*/
void prepare_new_connection_state(THD* thd)
{
Security_context *sctx= thd->security_ctx;
if (thd->client_capabilities & CLIENT_COMPRESS)
thd->net.compress=1; // Use compression
/*
Much of this is duplicated in create_embedded_thd() for the
embedded server library.
TODO: refactor this to avoid code duplication there
*/
thd->proc_info= 0;
thd->command= COM_SLEEP;
thd->set_time();
thd->init_for_queries();
if (opt_init_connect.length && !(sctx->master_access & SUPER_ACL))
{
execute_init_command(thd, &opt_init_connect, &LOCK_sys_init_connect);
if (thd->is_error())
{
ulong packet_length;
NET *net= &thd->net;
sql_print_warning(ER(ER_NEW_ABORTING_CONNECTION),
thd->thread_id,
thd->db ? thd->db : "unconnected",
sctx->user ? sctx->user : "unauthenticated",
sctx->host_or_ip, "init_connect command failed");
sql_print_warning("%s", thd->stmt_da->message());
thd->lex->current_select= 0;
my_net_set_read_timeout(net, thd->variables.net_wait_timeout);
thd->clear_error();
net_new_transaction(net);
packet_length= my_net_read(net);
/*
If my_net_read() failed, my_error() has been already called,
and the main Diagnostics Area contains an error condition.
*/
if (packet_length != packet_error)
my_error(ER_NEW_ABORTING_CONNECTION, MYF(0),
thd->thread_id,
thd->db ? thd->db : "unconnected",
sctx->user ? sctx->user : "unauthenticated",
sctx->host_or_ip, "init_connect command failed");
thd->server_status&= ~SERVER_STATUS_CLEAR_SET;
thd->protocol->end_statement();
thd->killed = THD::KILL_CONNECTION;
return;
}
thd->proc_info=0;
thd->set_time();
thd->init_for_queries();
}
}
/*
Thread handler for a connection
SYNOPSIS
handle_one_connection()
arg Connection object (THD)
IMPLEMENTATION
This function (normally) does the following:
- Initialize thread
- Initialize THD to be used with this thread
- Authenticate user
- Execute all queries sent on the connection
- Take connection down
- End thread / Handle next connection using thread from thread cache
*/
pthread_handler_t handle_one_connection(void *arg)
{
THD *thd= (THD*) arg;
mysql_thread_set_psi_id(thd->thread_id);
do_handle_one_connection(thd);
return 0;
}
bool thd_prepare_connection(THD *thd)
{
bool rc;
lex_start(thd);
rc= login_connection(thd);
MYSQL_AUDIT_NOTIFY_CONNECTION_CONNECT(thd);
if (rc)
return rc;
MYSQL_CONNECTION_START(thd->thread_id, &thd->security_ctx->priv_user[0],
(char *) thd->security_ctx->host_or_ip);
prepare_new_connection_state(thd);
return FALSE;
}
bool thd_is_connection_alive(THD *thd)
{
NET *net= &thd->net;
if (!net->error &&
net->vio != 0 &&
!(thd->killed == THD::KILL_CONNECTION))
return TRUE;
return FALSE;
}
void do_handle_one_connection(THD *thd_arg)
{
THD *thd= thd_arg;
thd->thr_create_utime= my_micro_time();
if (MYSQL_CALLBACK_ELSE(thread_scheduler, init_new_connection_thread, (), 0))
{
close_connection(thd, ER_OUT_OF_RESOURCES);
statistic_increment(aborted_connects,&LOCK_status);
MYSQL_CALLBACK(thread_scheduler, end_thread, (thd, 0));
return;
}
/*
If a thread was created to handle this connection:
increment slow_launch_threads counter if it took more than
slow_launch_time seconds to create the thread.
*/
if (thd->prior_thr_create_utime)
{
ulong launch_time= (ulong) (thd->thr_create_utime -
thd->prior_thr_create_utime);
if (launch_time >= slow_launch_time*1000000L)
statistic_increment(slow_launch_threads, &LOCK_status);
thd->prior_thr_create_utime= 0;
}
/*
handle_one_connection() is normally the only way a thread would
start and would always be on the very high end of the stack ,
therefore, the thread stack always starts at the address of the
first local variable of handle_one_connection, which is thd. We
need to know the start of the stack so that we could check for
stack overruns.
*/
thd->thread_stack= (char*) &thd;
if (setup_connection_thread_globals(thd))
return;
for (;;)
{
bool rc;
rc= thd_prepare_connection(thd);
if (rc)
goto end_thread;
while (thd_is_connection_alive(thd))
{
mysql_audit_release(thd);
if (do_command(thd))
break;
}
end_connection(thd);
end_thread:
close_connection(thd);
if (MYSQL_CALLBACK_ELSE(thread_scheduler, end_thread, (thd, 1), 0))
return; // Probably no-threads
/*
If end_thread() returns, we are either running with
thread-handler=no-threads or this thread has been schedule to
handle the next connection.
*/
thd= current_thd;
thd->thread_stack= (char*) &thd;
}
}
#endif /* EMBEDDED_LIBRARY */
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