lib/ldb/ldb_tdb/ldb_cache.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Andrew Tridgell  2004
   5
   6      ** NOTE! The following LGPL license applies to the ldb
   7      ** library. This does NOT imply that all of Samba is released
   8      ** under the LGPL
   9
  10    This library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 3 of the License, or (at your option) any later version.
  14
  15    This library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 /*
  25  *  Name: ldb
  26  *
  27  *  Component: ldb tdb cache functions
  28  *
  29  *  Description: cache special records in a ldb/tdb
  30  *
  31  *  Author: Andrew Tridgell
  32  */
  33
  34 #include "ldb_tdb.h"
  35 #include "ldb_private.h"
  36
  37 #define LTDB_FLAG_CASE_INSENSITIVE (1<<0)
  38 #define LTDB_FLAG_INTEGER          (1<<1)
  39 #define LTDB_FLAG_HIDDEN           (1<<2)
  40
  41 /* valid attribute flags */
  42 static const struct {
  43         const char *name;
  44         int value;
  45 } ltdb_valid_attr_flags[] = {
  46         { "CASE_INSENSITIVE", LTDB_FLAG_CASE_INSENSITIVE },
  47         { "INTEGER", LTDB_FLAG_INTEGER },
  48         { "HIDDEN", LTDB_FLAG_HIDDEN },
  49         { "NONE", 0 },
  50         { NULL, 0 }
  51 };
  52
  53
  54 /*
  55   de-register any special handlers for @ATTRIBUTES
  56 */
  57 static void ltdb_attributes_unload(struct ldb_module *module)
  58 {
  59         struct ldb_context *ldb;
  60         void *data = ldb_module_get_private(module);
  61         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
  62         struct ldb_message *msg;
  63         unsigned int i;
  64
  65         ldb = ldb_module_get_ctx(module);
  66
  67         if (ltdb->cache->attributes == NULL) {
  68                 /* no previously loaded attributes */
  69                 return;
  70         }
  71
  72         msg = ltdb->cache->attributes;
  73         for (i=0;i<msg->num_elements;i++) {
  74                 ldb_schema_attribute_remove(ldb, msg->elements[i].name);
  75         }
  76
  77         talloc_free(ltdb->cache->attributes);
  78         ltdb->cache->attributes = NULL;
  79 }
  80
  81 /*
  82   add up the attrib flags for a @ATTRIBUTES element
  83 */
  84 static int ltdb_attributes_flags(struct ldb_message_element *el, unsigned *v)
  85 {
  86         unsigned int i;
  87         unsigned value = 0;
  88         for (i=0;i<el->num_values;i++) {
  89                 unsigned int j;
  90                 for (j=0;ltdb_valid_attr_flags[j].name;j++) {
  91                         if (strcmp(ltdb_valid_attr_flags[j].name,
  92                                    (char *)el->values[i].data) == 0) {
  93                                 value |= ltdb_valid_attr_flags[j].value;
  94                                 break;
  95                         }
  96                 }
  97                 if (ltdb_valid_attr_flags[j].name == NULL) {
  98                         return -1;
  99                 }
 100         }
 101         *v = value;
 102         return 0;
 103 }
 104
 105 /*
 106   register any special handlers from @ATTRIBUTES
 107 */
 108 static int ltdb_attributes_load(struct ldb_module *module)
 109 {
 110         struct ldb_context *ldb;
 111         void *data = ldb_module_get_private(module);
 112         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 113         struct ldb_message *msg = ltdb->cache->attributes;
 114         struct ldb_dn *dn;
 115         unsigned int i;
 116         int r;
 117
 118         ldb = ldb_module_get_ctx(module);
 119
 120         if (ldb->schema.attribute_handler_override) {
 121                 /* we skip loading the @ATTRIBUTES record when a module is supplying
 122                    its own attribute handling */
 123                 return 0;
 124         }
 125
 126         dn = ldb_dn_new(module, ldb, LTDB_ATTRIBUTES);
 127         if (dn == NULL) goto failed;
 128
 129         r = ltdb_search_dn1(module, dn, msg);
 130         talloc_free(dn);
 131         if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
 132                 goto failed;
 133         }
 134         if (r == LDB_ERR_NO_SUCH_OBJECT) {
 135                 return 0;
 136         }
 137         /* mapping these flags onto ldap 'syntaxes' isn't strictly correct,
 138            but its close enough for now */
 139         for (i=0;i<msg->num_elements;i++) {
 140                 unsigned flags;
 141                 const char *syntax;
 142                 const struct ldb_schema_syntax *s;
 143
 144                 if (ltdb_attributes_flags(&msg->elements[i], &flags) != 0) {
 145                         ldb_debug(ldb, LDB_DEBUG_ERROR, "Invalid @ATTRIBUTES element for '%s'", msg->elements[i].name);
 146                         goto failed;
 147                 }
 148                 switch (flags & ~LTDB_FLAG_HIDDEN) {
 149                 case 0:
 150                         syntax = LDB_SYNTAX_OCTET_STRING;
 151                         break;
 152                 case LTDB_FLAG_CASE_INSENSITIVE:
 153                         syntax = LDB_SYNTAX_DIRECTORY_STRING;
 154                         break;
 155                 case LTDB_FLAG_INTEGER:
 156                         syntax = LDB_SYNTAX_INTEGER;
 157                         break;
 158                 default:
 159                         ldb_debug(ldb, LDB_DEBUG_ERROR,
 160                                   "Invalid flag combination 0x%x for '%s' in @ATTRIBUTES",
 161                                   flags, msg->elements[i].name);
 162                         goto failed;
 163                 }
 164
 165                 s = ldb_standard_syntax_by_name(ldb, syntax);
 166                 if (s == NULL) {
 167                         ldb_debug(ldb, LDB_DEBUG_ERROR,
 168                                   "Invalid attribute syntax '%s' for '%s' in @ATTRIBUTES",
 169                                   syntax, msg->elements[i].name);
 170                         goto failed;
 171                 }
 172
 173                 flags |= LDB_ATTR_FLAG_ALLOCATED;
 174                 if (ldb_schema_attribute_add_with_syntax(ldb, msg->elements[i].name, flags, s) != 0) {
 175                         goto failed;
 176                 }
 177         }
 178
 179         return 0;
 180 failed:
 181         return -1;
 182 }
 183
 184
 185 /*
 186   initialise the baseinfo record
 187 */
 188 static int ltdb_baseinfo_init(struct ldb_module *module)
 189 {
 190         struct ldb_context *ldb;
 191         void *data = ldb_module_get_private(module);
 192         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 193         struct ldb_message *msg;
 194         struct ldb_message_element el;
 195         struct ldb_val val;
 196         int ret;
 197         /* the initial sequence number must be different from the one
 198            set in ltdb_cache_free(). Thanks to Jon for pointing this
 199            out. */
 200         const char *initial_sequence_number = "1";
 201
 202         ldb = ldb_module_get_ctx(module);
 203
 204         ltdb->sequence_number = atof(initial_sequence_number);
 205
 206         msg = ldb_msg_new(ltdb);
 207         if (msg == NULL) {
 208                 goto failed;
 209         }
 210
 211         msg->num_elements = 1;
 212         msg->elements = &el;
 213         msg->dn = ldb_dn_new(msg, ldb, LTDB_BASEINFO);
 214         if (!msg->dn) {
 215                 goto failed;
 216         }
 217         el.name = talloc_strdup(msg, LTDB_SEQUENCE_NUMBER);
 218         if (!el.name) {
 219                 goto failed;
 220         }
 221         el.values = &val;
 222         el.num_values = 1;
 223         el.flags = 0;
 224         val.data = (uint8_t *)talloc_strdup(msg, initial_sequence_number);
 225         if (!val.data) {
 226                 goto failed;
 227         }
 228         val.length = 1;
 229
 230         ret = ltdb_store(module, msg, TDB_INSERT);
 231
 232         talloc_free(msg);
 233
 234         return ret;
 235
 236 failed:
 237         talloc_free(msg);
 238         errno = ENOMEM;
 239         return LDB_ERR_OPERATIONS_ERROR;
 240 }
 241
 242 /*
 243   free any cache records
 244  */
 245 static void ltdb_cache_free(struct ldb_module *module)
 246 {
 247         void *data = ldb_module_get_private(module);
 248         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 249
 250         ltdb->sequence_number = 0;
 251         talloc_free(ltdb->cache);
 252         ltdb->cache = NULL;
 253 }
 254
 255 /*
 256   force a cache reload
 257 */
 258 int ltdb_cache_reload(struct ldb_module *module)
 259 {
 260         ltdb_attributes_unload(module);
 261         ltdb_cache_free(module);
 262         return ltdb_cache_load(module);
 263 }
 264
 265 /*
 266   load the cache records
 267 */
 268 int ltdb_cache_load(struct ldb_module *module)
 269 {
 270         struct ldb_context *ldb;
 271         void *data = ldb_module_get_private(module);
 272         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 273         struct ldb_dn *baseinfo_dn = NULL, *options_dn = NULL;
 274         struct ldb_dn *indexlist_dn = NULL;
 275         uint64_t seq;
 276         struct ldb_message *baseinfo = NULL, *options = NULL;
 277         int r;
 278
 279         ldb = ldb_module_get_ctx(module);
 280
 281         /* a very fast check to avoid extra database reads */
 282         if (ltdb->cache != NULL &&
 283             tdb_get_seqnum(ltdb->tdb) == ltdb->tdb_seqnum) {
 284                 return 0;
 285         }
 286
 287         if (ltdb->cache == NULL) {
 288                 ltdb->cache = talloc_zero(ltdb, struct ltdb_cache);
 289                 if (ltdb->cache == NULL) goto failed;
 290                 ltdb->cache->indexlist = ldb_msg_new(ltdb->cache);
 291                 ltdb->cache->attributes = ldb_msg_new(ltdb->cache);
 292                 if (ltdb->cache->indexlist == NULL ||
 293                     ltdb->cache->attributes == NULL) {
 294                         goto failed;
 295                 }
 296         }
 297
 298         baseinfo = ldb_msg_new(ltdb->cache);
 299         if (baseinfo == NULL) goto failed;
 300
 301         baseinfo_dn = ldb_dn_new(baseinfo, ldb, LTDB_BASEINFO);
 302         if (baseinfo_dn == NULL) goto failed;
 303
 304         r= ltdb_search_dn1(module, baseinfo_dn, baseinfo);
 305         if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
 306                 goto failed;
 307         }
 308
 309         /* possibly initialise the baseinfo */
 310         if (r == LDB_ERR_NO_SUCH_OBJECT) {
 311
 312                 if (tdb_transaction_start(ltdb->tdb) != 0) {
 313                         goto failed;
 314                 }
 315
 316                 /* error handling for ltdb_baseinfo_init() is by
 317                    looking for the record again. */
 318                 ltdb_baseinfo_init(module);
 319
 320                 tdb_transaction_commit(ltdb->tdb);
 321
 322                 if (ltdb_search_dn1(module, baseinfo_dn, baseinfo) != LDB_SUCCESS) {
 323                         goto failed;
 324                 }
 325         }
 326
 327         ltdb->tdb_seqnum = tdb_get_seqnum(ltdb->tdb);
 328
 329         /* if the current internal sequence number is the same as the one
 330            in the database then assume the rest of the cache is OK */
 331         seq = ldb_msg_find_attr_as_uint64(baseinfo, LTDB_SEQUENCE_NUMBER, 0);
 332         if (seq == ltdb->sequence_number) {
 333                 goto done;
 334         }
 335         ltdb->sequence_number = seq;
 336
 337         /* Read an interpret database options */
 338         options = ldb_msg_new(ltdb->cache);
 339         if (options == NULL) goto failed;
 340
 341         options_dn = ldb_dn_new(options, ldb, LTDB_OPTIONS);
 342         if (options_dn == NULL) goto failed;
 343
 344         r= ltdb_search_dn1(module, options_dn, options);
 345         if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
 346                 goto failed;
 347         }
 348
 349         /* set flags if they do exist */
 350         if (r == LDB_SUCCESS) {
 351                 ltdb->check_base = ldb_msg_find_attr_as_bool(options,
 352                                                              LTDB_CHECK_BASE,
 353                                                              false);
 354                 ltdb->disallow_dn_filter = ldb_msg_find_attr_as_bool(options,
 355                                                                      LTDB_DISALLOW_DN_FILTER,
 356                                                                      false);
 357         } else {
 358                 ltdb->check_base = false;
 359                 ltdb->disallow_dn_filter = false;
 360         }
 361
 362         talloc_free(ltdb->cache->indexlist);
 363         ltdb_attributes_unload(module); /* calls internally "talloc_free" */
 364
 365         ltdb->cache->indexlist = ldb_msg_new(ltdb->cache);
 366         ltdb->cache->attributes = ldb_msg_new(ltdb->cache);
 367         if (ltdb->cache->indexlist == NULL ||
 368             ltdb->cache->attributes == NULL) {
 369                 goto failed;
 370         }
 371         ltdb->cache->one_level_indexes = false;
 372         ltdb->cache->attribute_indexes = false;
 373
 374         indexlist_dn = ldb_dn_new(module, ldb, LTDB_INDEXLIST);
 375         if (indexlist_dn == NULL) goto failed;
 376
 377         r = ltdb_search_dn1(module, indexlist_dn, ltdb->cache->indexlist);
 378         if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
 379                 goto failed;
 380         }
 381
 382         if (ldb_msg_find_element(ltdb->cache->indexlist, LTDB_IDXONE) != NULL) {
 383                 ltdb->cache->one_level_indexes = true;
 384         }
 385         if (ldb_msg_find_element(ltdb->cache->indexlist, LTDB_IDXATTR) != NULL) {
 386                 ltdb->cache->attribute_indexes = true;
 387         }
 388
 389         if (ltdb_attributes_load(module) == -1) {
 390                 goto failed;
 391         }
 392
 393 done:
 394         talloc_free(options);
 395         talloc_free(baseinfo);
 396         talloc_free(indexlist_dn);
 397         return 0;
 398
 399 failed:
 400         talloc_free(options);
 401         talloc_free(baseinfo);
 402         talloc_free(indexlist_dn);
 403         return -1;
 404 }
 405
 406
 407 /*
 408   increase the sequence number to indicate a database change
 409 */
 410 int ltdb_increase_sequence_number(struct ldb_module *module)
 411 {
 412         struct ldb_context *ldb;
 413         void *data = ldb_module_get_private(module);
 414         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 415         struct ldb_message *msg;
 416         struct ldb_message_element el[2];
 417         struct ldb_val val;
 418         struct ldb_val val_time;
 419         time_t t = time(NULL);
 420         char *s = NULL;
 421         int ret;
 422
 423         ldb = ldb_module_get_ctx(module);
 424
 425         msg = ldb_msg_new(ltdb);
 426         if (msg == NULL) {
 427                 errno = ENOMEM;
 428                 return LDB_ERR_OPERATIONS_ERROR;
 429         }
 430
 431         s = talloc_asprintf(msg, "%llu", ltdb->sequence_number+1);
 432         if (!s) {
 433                 talloc_free(msg);
 434                 errno = ENOMEM;
 435                 return LDB_ERR_OPERATIONS_ERROR;
 436         }
 437
 438         msg->num_elements = ARRAY_SIZE(el);
 439         msg->elements = el;
 440         msg->dn = ldb_dn_new(msg, ldb, LTDB_BASEINFO);
 441         if (msg->dn == NULL) {
 442                 talloc_free(msg);
 443                 errno = ENOMEM;
 444                 return LDB_ERR_OPERATIONS_ERROR;
 445         }
 446         el[0].name = talloc_strdup(msg, LTDB_SEQUENCE_NUMBER);
 447         if (el[0].name == NULL) {
 448                 talloc_free(msg);
 449                 errno = ENOMEM;
 450                 return LDB_ERR_OPERATIONS_ERROR;
 451         }
 452         el[0].values = &val;
 453         el[0].num_values = 1;
 454         el[0].flags = LDB_FLAG_MOD_REPLACE;
 455         val.data = (uint8_t *)s;
 456         val.length = strlen(s);
 457
 458         el[1].name = talloc_strdup(msg, LTDB_MOD_TIMESTAMP);
 459         if (el[1].name == NULL) {
 460                 talloc_free(msg);
 461                 errno = ENOMEM;
 462                 return LDB_ERR_OPERATIONS_ERROR;
 463         }
 464         el[1].values = &val_time;
 465         el[1].num_values = 1;
 466         el[1].flags = LDB_FLAG_MOD_REPLACE;
 467
 468         s = ldb_timestring(msg, t);
 469         if (s == NULL) {
 470                 talloc_free(msg);
 471                 return LDB_ERR_OPERATIONS_ERROR;
 472         }
 473
 474         val_time.data = (uint8_t *)s;
 475         val_time.length = strlen(s);
 476
 477         ret = ltdb_modify_internal(module, msg, NULL);
 478
 479         talloc_free(msg);
 480
 481         if (ret == LDB_SUCCESS) {
 482                 ltdb->sequence_number += 1;
 483         }
 484
 485         /* updating the tdb_seqnum here avoids us reloading the cache
 486            records due to our own modification */
 487         ltdb->tdb_seqnum = tdb_get_seqnum(ltdb->tdb);
 488
 489         return ret;
 490 }
 491
 492 int ltdb_check_at_attributes_values(const struct ldb_val *value)
 493 {
 494         unsigned int i;
 495
 496         for (i = 0; ltdb_valid_attr_flags[i].name != NULL; i++) {
 497                 if ((strcmp(ltdb_valid_attr_flags[i].name, (char *)value->data) == 0)) {
 498                         return 0;
 499                 }
 500         }
 501
 502         return -1;
 503 }
 504