~drizzle-trunk/drizzle/development

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
/* Copyright (C) 2007 MySQL AB

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


/*
  Functions to autenticate and handle reqests for a connection
*/

#include "mysql_priv.h"

#define MIN_HANDSHAKE_SIZE      6

/*
  Get structure for logging connection data for the current user
*/

char *ip_to_hostname(struct sockaddr_storage *in, int addrLen)
{
  char *name;

  int gxi_error;
  char hostname_buff[NI_MAXHOST];

  /* Historical comparison for 127.0.0.1 */
  gxi_error= getnameinfo((struct sockaddr *)in, addrLen,
                         hostname_buff, NI_MAXHOST,
                         NULL, 0, NI_NUMERICHOST);
  if (gxi_error)
  {
    return NULL;
  }

  if (!(name= my_strdup(hostname_buff, MYF(0))))
  {
    return NULL;
  }

  return NULL;
}

/**
  Check if user exist and password supplied is correct.

  @param  thd         thread handle, thd->security_ctx->{host,user,ip} are used
  @param  command     originator of the check: now check_user is called
                      during connect and change user procedures; used for
                      logging.
  @param  passwd      scrambled password received from client
  @param  passwd_len  length of scrambled password
  @param  db          database name to connect to, may be NULL
  @param  check_count true if establishing a new connection. In this case
                      check that we have not exceeded the global
                      max_connections limist

  @note Host, user and passwd may point to communication buffer.
  Current implementation does not depend on that, but future changes
  should be done with this in mind; 'thd' is INOUT, all other params
  are 'IN'.

  @retval  0  OK; thd->security_ctx->user/master_access/priv_user/db_access and
              thd->db are updated; OK is sent to the client.
  @retval  1  error, e.g. access denied or handshake error, not sent to
              the client. A message is pushed into the error stack.
*/

int
check_user(THD *thd, enum enum_server_command command,
           const char *passwd __attribute__((__unused__)),
           uint passwd_len, const char *db,
           bool check_count)
{
  LEX_STRING db_str= { (char *) db, db ? strlen(db) : 0 };

  /*
    Clear thd->db as it points to something, that will be freed when
    connection is closed. We don't want to accidentally free a wrong
    pointer if connect failed. Also in case of 'CHANGE USER' failure,
    current database will be switched to 'no database selected'.
  */
  thd->reset_db(NULL, 0);

  my_bool opt_secure_auth_local;
  pthread_mutex_lock(&LOCK_global_system_variables);
  opt_secure_auth_local= opt_secure_auth;
  pthread_mutex_unlock(&LOCK_global_system_variables);

  /*
    If the server is running in secure auth mode, short scrambles are 
    forbidden.
  */
  if (opt_secure_auth_local && passwd_len == SCRAMBLE_LENGTH_323)
  {
    my_error(ER_NOT_SUPPORTED_AUTH_MODE, MYF(0));
    general_log_print(thd, COM_CONNECT, ER(ER_NOT_SUPPORTED_AUTH_MODE));
    return(1);
  }
  if (passwd_len != 0 &&
      passwd_len != SCRAMBLE_LENGTH &&
      passwd_len != SCRAMBLE_LENGTH_323)
  {
    my_error(ER_HANDSHAKE_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);
    return(1);
  }

  USER_RESOURCES ur;
  thd->security_ctx->skip_grants();
  memset(&ur, 0, sizeof(USER_RESOURCES));

  if (check_count)
  {
    pthread_mutex_lock(&LOCK_connection_count);
    bool count_ok= connection_count <= max_connections;
    VOID(pthread_mutex_unlock(&LOCK_connection_count));

    if (!count_ok)
    {                                         // too many connections
      my_error(ER_CON_COUNT_ERROR, MYF(0));
      return(1);
    }
  }

  /*
    Log the command before authentication checks, so that the user can
    check the log for the tried login tried and also to detect
    break-in attempts.
  */
  general_log_print(thd, command,
                    (thd->main_security_ctx.priv_user ==
                     thd->main_security_ctx.user ?
                     (char*) "%s@%s on %s" :
                     (char*) "%s@%s as anonymous on %s"),
                    thd->main_security_ctx.user,
                    thd->main_security_ctx.host_or_ip,
                    db ? db : (char*) "");

  /*
    This is the default access rights for the current database.  It's
    set to 0 here because we don't have an active database yet (and we
    may not have an active database to set.
  */
  thd->main_security_ctx.db_access=0;

  /* Change database if necessary */
  if (db && db[0])
  {
    if (mysql_change_db(thd, &db_str, false))
    {
      /* mysql_change_db() has pushed the error message. */
      return(1);
    }
  }
  my_ok(thd);
  thd->password= test(passwd_len);          // remember for error messages 
  /* Ready to handle queries */
  return(0);
}


/*
  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((char*) uc,MYF(0));
}

void thd_init_client_charset(THD *thd, uint cs_number)
{
  /*
   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 ||
      !(thd->variables.character_set_client= get_charset(cs_number, MYF(0))) ||
      !my_strcasecmp(&my_charset_latin1,
                     global_system_variables.character_set_client->name,
                     thd->variables.character_set_client->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
  {
    thd->variables.character_set_results=
      thd->variables.collation_connection= 
      thd->variables.character_set_client;
  }
}


/*
  Initialize connection threads
*/

bool init_new_connection_handler_thread()
{
  pthread_detach_this_thread();
  /* Win32 calls this in pthread_create */
  if (my_thread_init())
    return 1;
  return 0;
}

/*
  Perform handshake, authorize client and update thd ACL variables.

  SYNOPSIS
    check_connection()
    thd  thread handle

  RETURN
     0  success, OK is sent to user, thd is updated.
    -1  error, which is sent to user
   > 0  error code (not sent to user)
*/

static int check_connection(THD *thd)
{
  NET *net= &thd->net;
  ulong pkt_len= 0;
  char *end;

#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), thd->main_security_ctx.host_or_ip);
      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;
    thd->main_security_ctx.host= ip_to_hostname(&net->vio->remote, 
                                                net->vio->addrLen);
    thd->main_security_ctx.host_or_ip= thd->main_security_ctx.host;
  }
  else /* Hostname given means that the connection was on a socket */
  {
    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);
  
  ulong server_capabilites;
  {
    /* buff[] needs to big enough to hold the server_version variable */
    char buff[SERVER_VERSION_LENGTH + SCRAMBLE_LENGTH + 64];
    server_capabilites= CLIENT_BASIC_FLAGS;

    if (opt_using_transactions)
      server_capabilites|= CLIENT_TRANSACTIONS;
#ifdef HAVE_COMPRESS
    server_capabilites|= CLIENT_COMPRESS;
#endif /* HAVE_COMPRESS */

    end= strnmov(buff, server_version, SERVER_VERSION_LENGTH) + 1;
    int4store((uchar*) end, thd->thread_id);
    end+= 4;
    /*
      So as check_connection is the only entry point to authorization
      procedure, scramble is set here. This gives us new scramble for
      each handshake.
    */
    create_random_string(thd->scramble, SCRAMBLE_LENGTH, &thd->rand);
    /*
      Old clients does not understand long scrambles, but can ignore packet
      tail: that's why first part of the scramble is placed here, and second
      part at the end of packet.
    */
    end= strmake(end, thd->scramble, SCRAMBLE_LENGTH_323) + 1;
   
    int2store(end, server_capabilites);
    /* write server characteristics: up to 16 bytes allowed */
    end[2]=(char) default_charset_info->number;
    int2store(end+3, thd->server_status);
    bzero(end+5, 13);
    end+= 18;
    /* write scramble tail */
    end= strmake(end, thd->scramble + SCRAMBLE_LENGTH_323, 
                 SCRAMBLE_LENGTH - SCRAMBLE_LENGTH_323) + 1;

    /* At this point we write connection message and read reply */
    if (net_write_command(net, (uchar) protocol_version, (uchar*) "", 0,
                          (uchar*) buff, (size_t) (end-buff)) ||
	(pkt_len= my_net_read(net)) == packet_error ||
	pkt_len < MIN_HANDSHAKE_SIZE)
    {
      my_error(ER_HANDSHAKE_ERROR, MYF(0),
               thd->main_security_ctx.host_or_ip);
      return 1;
    }
  }
#ifdef _CUSTOMCONFIG_
#include "_cust_sql_parse.h"
#endif
  if (thd->packet.alloc(thd->variables.net_buffer_length))
    return 1; /* The error is set by alloc(). */

  thd->client_capabilities= uint2korr(net->read_pos);
  if (thd->client_capabilities & CLIENT_PROTOCOL_41)
  {
    thd->client_capabilities|= ((ulong) uint2korr(net->read_pos+2)) << 16;
    thd->max_client_packet_length= uint4korr(net->read_pos+4);
    thd_init_client_charset(thd, (uint) net->read_pos[8]);
    thd->update_charset();
    end= (char*) net->read_pos+32;
  }
  else
  {
    thd->max_client_packet_length= uint3korr(net->read_pos+2);
    end= (char*) net->read_pos+5;
  }
  /*
    Disable those bits which are not supported by the server.
    This is a precautionary measure, if the client lies. See Bug#27944.
  */
  thd->client_capabilities&= server_capabilites;

  if (thd->client_capabilities & CLIENT_IGNORE_SPACE)
    thd->variables.sql_mode|= MODE_IGNORE_SPACE;

  if (end >= (char*) net->read_pos+ pkt_len +2)
  {

    my_error(ER_HANDSHAKE_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);
    return 1;
  }

  if (thd->client_capabilities & CLIENT_INTERACTIVE)
    thd->variables.net_wait_timeout= thd->variables.net_interactive_timeout;
  if ((thd->client_capabilities & CLIENT_TRANSACTIONS) &&
      opt_using_transactions)
    net->return_status= &thd->server_status;

  char *user= end;
  char *passwd= strend(user)+1;
  uint user_len= passwd - user - 1;
  char *db= passwd;
  char db_buff[NAME_LEN + 1];           // buffer to store db in utf8
  char user_buff[USERNAME_LENGTH + 1];	// buffer to store user in utf8
  uint dummy_errors;

  /*
    Old clients send null-terminated string as password; new clients send
    the size (1 byte) + string (not null-terminated). Hence in case of empty
    password both send '\0'.

    This strlen() can't be easily deleted without changing protocol.

    Cast *passwd to an unsigned char, so that it doesn't extend the sign for
    *passwd > 127 and become 2**32-127+ after casting to uint.
  */
  uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ?
    (uchar)(*passwd++) : strlen(passwd);
  db= thd->client_capabilities & CLIENT_CONNECT_WITH_DB ?
    db + passwd_len + 1 : 0;
  /* strlen() can't be easily deleted without changing protocol */
  uint db_len= db ? strlen(db) : 0;

  if (passwd + passwd_len + db_len > (char *)net->read_pos + pkt_len)
  {
    my_error(ER_HANDSHAKE_ERROR, MYF(0), thd->main_security_ctx.host_or_ip);
    return 1;
  }

  /* Since 4.1 all database names are stored in utf8 */
  if (db)
  {
    db_buff[copy_and_convert(db_buff, sizeof(db_buff)-1,
                             system_charset_info,
                             db, db_len,
                             thd->charset(), &dummy_errors)]= 0;
    db= db_buff;
  }

  user_buff[user_len= copy_and_convert(user_buff, sizeof(user_buff)-1,
                                       system_charset_info, user, user_len,
                                       thd->charset(), &dummy_errors)]= '\0';
  user= user_buff;

  /* If username starts and ends in "'", chop them off */
  if (user_len > 1 && user[0] == '\'' && user[user_len - 1] == '\'')
  {
    user[user_len-1]= 0;
    user++;
    user_len-= 2;
  }

  if (thd->main_security_ctx.user)
    x_free(thd->main_security_ctx.user);
  if (!(thd->main_security_ctx.user= my_strdup(user, MYF(MY_WME))))
    return 1; /* The error is set by my_strdup(). */
  return check_user(thd, COM_CONNECT, passwd, passwd_len, db, true);
}


/*
  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, 1);
    statistic_increment(aborted_connects,&LOCK_status);
    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;

  /* Use "connect_timeout" value during connection phase */
  my_net_set_read_timeout(net, connect_timeout);
  my_net_set_write_timeout(net, connect_timeout);
  
  lex_start(thd);

  error= check_connection(thd);
  net_end_statement(thd);

  if (error)
  {						// Wrong permissions
    statistic_increment(aborted_connects,&LOCK_status);
    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);
  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->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->main_da.is_error() ? thd->main_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->variables.max_join_size == HA_POS_ERROR)
    thd->options |= OPTION_BIG_SELECTS;
  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->version= refresh_version;
  thd->proc_info= 0;
  thd->command= COM_SLEEP;
  thd->set_time();
  thd->init_for_queries();

  /* In the past this would only run of the user did not have SUPER_ACL */
  if (sys_init_connect.value_length)
  {
    execute_init_command(thd, &sys_init_connect, &LOCK_sys_init_connect);
    if (thd->is_error())
    {
      thd->killed= THD::KILL_CONNECTION;
      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->main_da.message());
    }
    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;
  ulong launch_time= (ulong) ((thd->thr_create_utime= my_micro_time()) -
                              thd->connect_utime);

  if (thread_scheduler.init_new_connection_thread())
  {
    close_connection(thd, ER_OUT_OF_RESOURCES, 1);
    statistic_increment(aborted_connects,&LOCK_status);
    thread_scheduler.end_thread(thd,0);
    return 0;
  }
  if (launch_time >= slow_launch_time*1000000L)
    statistic_increment(slow_launch_threads,&LOCK_status);

  /*
    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 0;

  for (;;)
  {
    NET *net= &thd->net;

    if (login_connection(thd))
      goto end_thread;

    prepare_new_connection_state(thd);

    while (!net->error && net->vio != 0 &&
           !(thd->killed == THD::KILL_CONNECTION))
    {
      if (do_command(thd))
	break;
    }
    end_connection(thd);
   
end_thread:
    close_connection(thd, 0, 1);
    if (thread_scheduler.end_thread(thd,1))
      return 0;                                 // 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;
  }
}