source4/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 LDB_SUCCESS;
 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 = talloc(ltdb, struct ldb_message);
 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 = talloc_zero(ltdb->cache, struct ldb_message);
 291                 ltdb->cache->attributes = talloc_zero(ltdb->cache, struct ldb_message);
 292                 if (ltdb->cache->indexlist == NULL ||
 293                     ltdb->cache->attributes == NULL) {
 294                         goto failed;
 295                 }
 296         }
 297
 298         baseinfo = talloc(ltdb->cache, struct ldb_message);
 299         if (baseinfo == NULL) goto failed;
 300
 301         baseinfo_dn = ldb_dn_new(module, 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                 if (ltdb_baseinfo_init(module) != LDB_SUCCESS) {
 312                         goto failed;
 313                 }
 314                 if (ltdb_search_dn1(module, baseinfo_dn, baseinfo) != LDB_SUCCESS) {
 315                         goto failed;
 316                 }
 317         }
 318
 319         ltdb->tdb_seqnum = tdb_get_seqnum(ltdb->tdb);
 320
 321         /* if the current internal sequence number is the same as the one
 322            in the database then assume the rest of the cache is OK */
 323         seq = ldb_msg_find_attr_as_uint64(baseinfo, LTDB_SEQUENCE_NUMBER, 0);
 324         if (seq == ltdb->sequence_number) {
 325                 goto done;
 326         }
 327         ltdb->sequence_number = seq;
 328
 329         /* Read an interpret database options */
 330         options = talloc(ltdb->cache, struct ldb_message);
 331         if (options == NULL) goto failed;
 332
 333         options_dn = ldb_dn_new(options, ldb, LTDB_OPTIONS);
 334         if (options_dn == NULL) goto failed;
 335
 336         r= ltdb_search_dn1(module, options_dn, options);
 337         if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
 338                 goto failed;
 339         }
 340
 341         /* set flag for checking base DN on searches */
 342         if (r == LDB_SUCCESS) {
 343                 ltdb->check_base = ldb_msg_find_attr_as_bool(options, LTDB_CHECK_BASE, false);
 344         } else {
 345                 ltdb->check_base = false;
 346         }
 347
 348         talloc_free(ltdb->cache->last_attribute.name);
 349         memset(&ltdb->cache->last_attribute, 0, sizeof(ltdb->cache->last_attribute));
 350
 351         ltdb_attributes_unload(module);
 352
 353         talloc_free(ltdb->cache->indexlist);
 354
 355         ltdb->cache->indexlist = talloc_zero(ltdb->cache, struct ldb_message);
 356         ltdb->cache->attributes = talloc_zero(ltdb->cache, struct ldb_message);
 357         if (ltdb->cache->indexlist == NULL ||
 358             ltdb->cache->attributes == NULL) {
 359                 goto failed;
 360         }
 361         ltdb->cache->one_level_indexes = false;
 362         ltdb->cache->attribute_indexes = false;
 363
 364         indexlist_dn = ldb_dn_new(module, ldb, LTDB_INDEXLIST);
 365         if (indexlist_dn == NULL) goto failed;
 366
 367         r = ltdb_search_dn1(module, indexlist_dn, ltdb->cache->indexlist);
 368         if (r != LDB_SUCCESS && r != LDB_ERR_NO_SUCH_OBJECT) {
 369                 goto failed;
 370         }
 371
 372         if (ldb_msg_find_element(ltdb->cache->indexlist, LTDB_IDXONE) != NULL) {
 373                 ltdb->cache->one_level_indexes = true;
 374         }
 375         if (ldb_msg_find_element(ltdb->cache->indexlist, LTDB_IDXATTR) != NULL) {
 376                 ltdb->cache->attribute_indexes = true;
 377         }
 378
 379         if (ltdb_attributes_load(module) == -1) {
 380                 goto failed;
 381         }
 382
 383 done:
 384         talloc_free(options);
 385         talloc_free(baseinfo);
 386         talloc_free(baseinfo_dn);
 387         talloc_free(indexlist_dn);
 388         return 0;
 389
 390 failed:
 391         talloc_free(options);
 392         talloc_free(baseinfo);
 393         talloc_free(baseinfo_dn);
 394         talloc_free(indexlist_dn);
 395         return -1;
 396 }
 397
 398
 399 /*
 400   increase the sequence number to indicate a database change
 401 */
 402 int ltdb_increase_sequence_number(struct ldb_module *module)
 403 {
 404         struct ldb_context *ldb;
 405         void *data = ldb_module_get_private(module);
 406         struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
 407         struct ldb_message *msg;
 408         struct ldb_message_element el[2];
 409         struct ldb_val val;
 410         struct ldb_val val_time;
 411         time_t t = time(NULL);
 412         char *s = NULL;
 413         int ret;
 414
 415         ldb = ldb_module_get_ctx(module);
 416
 417         msg = talloc(ltdb, struct ldb_message);
 418         if (msg == NULL) {
 419                 errno = ENOMEM;
 420                 return LDB_ERR_OPERATIONS_ERROR;
 421         }
 422
 423         s = talloc_asprintf(msg, "%llu", ltdb->sequence_number+1);
 424         if (!s) {
 425                 errno = ENOMEM;
 426                 return LDB_ERR_OPERATIONS_ERROR;
 427         }
 428
 429         msg->num_elements = ARRAY_SIZE(el);
 430         msg->elements = el;
 431         msg->dn = ldb_dn_new(msg, ldb, LTDB_BASEINFO);
 432         if (msg->dn == NULL) {
 433                 talloc_free(msg);
 434                 errno = ENOMEM;
 435                 return LDB_ERR_OPERATIONS_ERROR;
 436         }
 437         el[0].name = talloc_strdup(msg, LTDB_SEQUENCE_NUMBER);
 438         if (el[0].name == NULL) {
 439                 talloc_free(msg);
 440                 errno = ENOMEM;
 441                 return LDB_ERR_OPERATIONS_ERROR;
 442         }
 443         el[0].values = &val;
 444         el[0].num_values = 1;
 445         el[0].flags = LDB_FLAG_MOD_REPLACE;
 446         val.data = (uint8_t *)s;
 447         val.length = strlen(s);
 448
 449         el[1].name = talloc_strdup(msg, LTDB_MOD_TIMESTAMP);
 450         if (el[1].name == NULL) {
 451                 talloc_free(msg);
 452                 errno = ENOMEM;
 453                 return LDB_ERR_OPERATIONS_ERROR;
 454         }
 455         el[1].values = &val_time;
 456         el[1].num_values = 1;
 457         el[1].flags = LDB_FLAG_MOD_REPLACE;
 458
 459         s = ldb_timestring(msg, t);
 460         if (s == NULL) {
 461                 return LDB_ERR_OPERATIONS_ERROR;
 462         }
 463
 464         val_time.data = (uint8_t *)s;
 465         val_time.length = strlen(s);
 466
 467         ret = ltdb_modify_internal(module, msg, NULL);
 468
 469         talloc_free(msg);
 470
 471         if (ret == LDB_SUCCESS) {
 472                 ltdb->sequence_number += 1;
 473         }
 474
 475         /* updating the tdb_seqnum here avoids us reloading the cache
 476            records due to our own modification */
 477         ltdb->tdb_seqnum = tdb_get_seqnum(ltdb->tdb);
 478
 479         return ret;
 480 }
 481
 482 int ltdb_check_at_attributes_values(const struct ldb_val *value)
 483 {
 484         unsigned int i;
 485
 486         for (i = 0; ltdb_valid_attr_flags[i].name != NULL; i++) {
 487                 if ((strcmp(ltdb_valid_attr_flags[i].name, (char *)value->data) == 0)) {
 488                         return 0;
 489                 }
 490         }
 491
 492         return -1;
 493 }
 494