1 2/* 3 ldb database library 4 5 Copyright (C) Simo Sorce 2004 6 7 ** NOTE! The following LGPL license applies to the ldb 8 ** library. This does NOT imply that all of Samba is released 9 ** under the LGPL 10 11 This library is free software; you can redistribute it and/or 12 modify it under the terms of the GNU Lesser General Public 13 License as published by the Free Software Foundation; either 14 version 3 of the License, or (at your option) any later version. 15 16 This library is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 Lesser General Public License for more details. 20 21 You should have received a copy of the GNU Lesser General Public 22 License along with this library; if not, see <http://www.gnu.org/licenses/>. 23*/ 24 25/* 26 * Name: ldb 27 * 28 * Component: ldb modules core 29 * 30 * Description: core modules routines 31 * 32 * Author: Simo Sorce 33 */ 34 35#include "includes.h" 36#include "ldb/include/includes.h" 37 38#if (_SAMBA_BUILD_ >= 4) 39#include "build.h" 40#include "dynconfig.h" 41#endif 42 43#define LDB_MODULE_PREFIX "modules:" 44#define LDB_MODULE_PREFIX_LEN 8 45 46static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string) 47{ 48 int i, len; 49 char *trimmed; 50 51 trimmed = talloc_strdup(mem_ctx, string); 52 if (!trimmed) { 53 return NULL; 54 } 55 56 len = strlen(trimmed); 57 for (i = 0; trimmed[i] != '\0'; i++) { 58 switch (trimmed[i]) { 59 case ' ': 60 case '\t': 61 case '\n': 62 memmove(&trimmed[i], &trimmed[i + 1], len -i -1); 63 break; 64 } 65 } 66 67 return trimmed; 68} 69 70 71/* modules are called in inverse order on the stack. 72 Lets place them as an admin would think the right order is. 73 Modules order is important */ 74const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string) 75{ 76 char **modules = NULL; 77 const char **m; 78 char *modstr, *p; 79 int i; 80 81 /* spaces not admitted */ 82 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string); 83 if ( ! modstr) { 84 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n"); 85 return NULL; 86 } 87 88 modules = talloc_realloc(mem_ctx, modules, char *, 2); 89 if ( ! modules ) { 90 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n"); 91 talloc_free(modstr); 92 return NULL; 93 } 94 talloc_steal(modules, modstr); 95 96 i = 0; 97 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */ 98 while ((p = strrchr(modstr, ',')) != NULL) { 99 *p = '\0'; 100 p++; 101 modules[i] = p; 102 103 i++; 104 modules = talloc_realloc(mem_ctx, modules, char *, i + 2); 105 if ( ! modules ) { 106 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n"); 107 return NULL; 108 } 109 110 } 111 modules[i] = modstr; 112 113 modules[i + 1] = NULL; 114 115 m = (const char **)modules; 116 117 return m; 118} 119 120static struct ops_list_entry { 121 const struct ldb_module_ops *ops; 122 struct ops_list_entry *next; 123} *registered_modules = NULL; 124 125static const struct ldb_module_ops *ldb_find_module_ops(const char *name) 126{ 127 struct ops_list_entry *e; 128 129 for (e = registered_modules; e; e = e->next) { 130 if (strcmp(e->ops->name, name) == 0) 131 return e->ops; 132 } 133 134 return NULL; 135} 136 137#ifndef STATIC_ldb_MODULES 138 139#ifdef HAVE_LDB_LDAP 140#define LDAP_INIT ldb_ldap_init, 141#else 142#define LDAP_INIT 143#endif 144 145#ifdef HAVE_LDB_SQLITE3 146#define SQLITE3_INIT ldb_sqlite3_init, 147#else 148#define SQLITE3_INIT 149#endif 150 151#define STATIC_ldb_MODULES \ 152 { \ 153 LDAP_INIT \ 154 SQLITE3_INIT \ 155 ldb_tdb_init, \ 156 ldb_operational_init, \ 157 ldb_rdn_name_init, \ 158 ldb_objectclass_init, \ 159 ldb_paged_results_init, \ 160 ldb_sort_init, \ 161 ldb_asq_init, \ 162 NULL \ 163 } 164#endif 165 166int ldb_global_init(void) 167{ 168 static int (*static_init_fns[])(void) = STATIC_ldb_MODULES; 169 170 static int initialized = 0; 171 int ret = 0, i; 172 173 if (initialized) 174 return 0; 175 176 initialized = 1; 177 178 for (i = 0; static_init_fns[i]; i++) { 179 if (static_init_fns[i]() == -1) 180 ret = -1; 181 } 182 183 return ret; 184} 185 186int ldb_register_module(const struct ldb_module_ops *ops) 187{ 188 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry); 189 190 if (ldb_find_module_ops(ops->name) != NULL) 191 return -1; 192 193 if (entry == NULL) 194 return -1; 195 196 entry->ops = ops; 197 entry->next = registered_modules; 198 registered_modules = entry; 199 200 return 0; 201} 202 203int ldb_try_load_dso(struct ldb_context *ldb, const char *name) 204{ 205 char *path; 206 void *handle; 207 int (*init_fn) (void); 208 char *modulesdir; 209 int ret; 210 211#ifdef HAVE_DLOPEN 212 if (getenv("LD_LDB_MODULE_PATH") != NULL) { 213 modulesdir = talloc_strdup(ldb, getenv("LD_LDB_MODULE_PATH")); 214 } else { 215#ifdef _SAMBA_BUILD_ 216 modulesdir = talloc_asprintf(ldb, "%s/ldb", get_dyn_LIBDIR()); 217#else 218 modulesdir = talloc_strdup(ldb, MODULESDIR); 219#endif 220 } 221 222 path = talloc_asprintf(ldb, "%s/%s.%s", modulesdir, name, SHLIBEXT); 223 224 talloc_free(modulesdir); 225 226 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path); 227 228 handle = dlopen(path, RTLD_NOW); 229 if (handle == NULL) { 230 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror()); 231 return -1; 232 } 233 234 init_fn = (int (*)(void))dlsym(handle, "init_samba_module"); 235 236 if (init_fn == NULL) { 237 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol " 238 "`init_samba_module' found in %s: %s\n", path, 239 dlerror()); 240 dlclose(handle); 241 return -1; 242 } 243 244 talloc_free(path); 245 246 ret = init_fn(); 247 if (ret == -1) { 248 dlclose(handle); 249 } 250 return ret; 251#else 252 ldb_debug(ldb, LDB_DEBUG_TRACE, "no dlopen() - not trying to load %s module\n", name); 253 return -1; 254#endif 255} 256 257int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out) 258{ 259 struct ldb_module *module; 260 int i; 261 262 module = backend; 263 264 for (i = 0; module_list[i] != NULL; i++) { 265 struct ldb_module *current; 266 const struct ldb_module_ops *ops; 267 268 ops = ldb_find_module_ops(module_list[i]); 269 if (ops == NULL) { 270 if (ldb_try_load_dso(ldb, module_list[i]) == 0) { 271 ops = ldb_find_module_ops(module_list[i]); 272 } 273 } 274 275 if (ops == NULL) { 276 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n", 277 module_list[i]); 278 continue; 279 } 280 281 current = talloc_zero(ldb, struct ldb_module); 282 if (current == NULL) { 283 return LDB_ERR_OPERATIONS_ERROR; 284 } 285 talloc_set_name(current, "ldb_module: %s", module_list[i]); 286 287 current->ldb = ldb; 288 current->ops = ops; 289 290 DLIST_ADD(module, current); 291 } 292 *out = module; 293 return LDB_SUCCESS; 294} 295 296int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module) 297{ 298 while (module && module->ops->init_context == NULL) 299 module = module->next; 300 301 if (module && module->ops->init_context && 302 module->ops->init_context(module) != LDB_SUCCESS) { 303 ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n"); 304 return LDB_ERR_OPERATIONS_ERROR; 305 } 306 307 return LDB_SUCCESS; 308} 309 310int ldb_load_modules(struct ldb_context *ldb, const char *options[]) 311{ 312 const char **modules = NULL; 313 int i; 314 int ret; 315 TALLOC_CTX *mem_ctx = talloc_new(ldb); 316 if (!mem_ctx) { 317 return LDB_ERR_OPERATIONS_ERROR; 318 } 319 320 /* find out which modules we are requested to activate */ 321 322 /* check if we have a custom module list passd as ldb option */ 323 if (options) { 324 for (i = 0; options[i] != NULL; i++) { 325 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) { 326 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]); 327 } 328 } 329 } 330 331 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */ 332 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) { 333 const char * const attrs[] = { "@LIST" , NULL}; 334 struct ldb_result *res = NULL; 335 struct ldb_dn *mods_dn; 336 337 mods_dn = ldb_dn_explode(mem_ctx, "@MODULES"); 338 if (mods_dn == NULL) { 339 talloc_free(mem_ctx); 340 return -1; 341 } 342 343 ret = ldb_search(ldb, ldb, &res, mods_dn, LDB_SCOPE_BASE, attrs, ""); 344 talloc_steal(mods_dn, res); 345 if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) { 346 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n"); 347 } else { 348 if (ret != LDB_SUCCESS) { 349 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb)); 350 talloc_free(mem_ctx); 351 return -1; 352 } 353 if (res->count > 1) { 354 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count); 355 talloc_free(mem_ctx); 356 return -1; 357 } 358 359 modules = ldb_modules_list_from_string(ldb, mem_ctx, 360 (const char *)res->msgs[0]->elements[0].values[0].data); 361 362 } 363 364 talloc_free(mods_dn); 365 } 366 367 if (modules != NULL) { 368 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules); 369 talloc_free(modules); 370 if (ret != LDB_SUCCESS) { 371 return ret; 372 } 373 } else { 374 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database\n"); 375 } 376 377 return ldb_init_module_chain(ldb, ldb->modules); 378} 379 380/* 381 by using this we allow ldb modules to only implement the functions they care about, 382 which makes writing a module simpler, and makes it more likely to keep working 383 when ldb is extended 384*/ 385#define FIND_OP(module, op) do { \ 386 struct ldb_context *ldb = module->ldb; \ 387 module = module->next; \ 388 while (module && module->ops->op == NULL) module = module->next; \ 389 if (module == NULL) { \ 390 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \ 391 return LDB_ERR_OPERATIONS_ERROR; \ 392 } \ 393} while (0) 394 395 396/* 397 helper functions to call the next module in chain 398*/ 399 400int ldb_next_request(struct ldb_module *module, struct ldb_request *request) 401{ 402 switch (request->operation) { 403 case LDB_SEARCH: 404 FIND_OP(module, search); 405 return module->ops->search(module, request); 406 case LDB_ADD: 407 FIND_OP(module, add); 408 return module->ops->add(module, request); 409 case LDB_MODIFY: 410 FIND_OP(module, modify); 411 return module->ops->modify(module, request); 412 case LDB_DELETE: 413 FIND_OP(module, del); 414 return module->ops->del(module, request); 415 case LDB_RENAME: 416 FIND_OP(module, rename); 417 return module->ops->rename(module, request); 418 case LDB_SEQUENCE_NUMBER: 419 FIND_OP(module, sequence_number); 420 return module->ops->sequence_number(module, request); 421 default: 422 FIND_OP(module, request); 423 return module->ops->request(module, request); 424 } 425} 426 427int ldb_next_init(struct ldb_module *module) 428{ 429 /* init is different in that it is not an error if modules 430 * do not require initialization */ 431 432 module = module->next; 433 434 while (module && module->ops->init_context == NULL) 435 module = module->next; 436 437 if (module == NULL) 438 return LDB_SUCCESS; 439 440 return module->ops->init_context(module); 441} 442 443int ldb_next_start_trans(struct ldb_module *module) 444{ 445 FIND_OP(module, start_transaction); 446 return module->ops->start_transaction(module); 447} 448 449int ldb_next_end_trans(struct ldb_module *module) 450{ 451 FIND_OP(module, end_transaction); 452 return module->ops->end_transaction(module); 453} 454 455int ldb_next_del_trans(struct ldb_module *module) 456{ 457 FIND_OP(module, del_transaction); 458 return module->ops->del_transaction(module); 459} 460