5 Copyright (C) Simo Sorce 2004
7 ** NOTE! The following LGPL license applies to the ldb
8 ** library. This does NOT imply that all of Samba is released
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.
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.
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/>.
28 * Component: ldb modules core
30 * Description: core modules routines
35 #include "ldb_includes.h"
37 #if (_SAMBA_BUILD_ >= 4)
40 #include "dynconfig.h"
43 #define LDB_MODULE_PREFIX "modules:"
44 #define LDB_MODULE_PREFIX_LEN 8
46 static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
51 trimmed = talloc_strdup(mem_ctx, string);
56 len = strlen(trimmed);
57 for (i = 0; trimmed[i] != '\0'; i++) {
62 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
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 */
74 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
76 char **modules = NULL;
81 /* spaces not admitted */
82 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
84 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
88 modules = talloc_realloc(mem_ctx, modules, char *, 2);
90 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
94 talloc_steal(modules, modstr);
97 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
98 while ((p = strrchr(modstr, ',')) != NULL) {
104 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
106 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
113 modules[i + 1] = NULL;
115 m = (const char **)modules;
120 static struct ops_list_entry {
121 const struct ldb_module_ops *ops;
122 struct ops_list_entry *next;
123 } *registered_modules = NULL;
125 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
127 struct ops_list_entry *e;
129 for (e = registered_modules; e; e = e->next) {
130 if (strcmp(e->ops->name, name) == 0)
137 #ifndef STATIC_LIBLDB_MODULES
140 #define LDAP_INIT ldb_ldap_init,
145 #ifdef HAVE_LDB_SQLITE3
146 #define SQLITE3_INIT ldb_sqlite3_init,
151 #define STATIC_LIBLDB_MODULES \
156 ldb_operational_init, \
158 ldb_objectclass_init, \
159 ldb_paged_results_init, \
166 int ldb_global_init(void)
168 static int (*static_init_fns[])(void) = STATIC_LIBLDB_MODULES;
170 static int initialized = 0;
178 for (i = 0; static_init_fns[i]; i++) {
179 if (static_init_fns[i]() == -1)
186 int ldb_register_module(const struct ldb_module_ops *ops)
188 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
190 if (ldb_find_module_ops(ops->name) != NULL)
197 entry->next = registered_modules;
198 registered_modules = entry;
203 int ldb_try_load_dso(struct ldb_context *ldb, const char *name)
207 int (*init_fn) (void);
210 if (getenv("LD_LDB_MODULE_PATH") != NULL) {
211 modulesdir = talloc_strdup(ldb, getenv("LD_LDB_MODULE_PATH"));
214 modulesdir = talloc_asprintf(ldb, "%s/ldb", dyn_MODULESDIR);
216 modulesdir = talloc_strdup(ldb, MODULESDIR);
220 path = talloc_asprintf(ldb, "%s/%s.%s", modulesdir, name, SHLIBEXT);
222 talloc_free(modulesdir);
224 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
226 handle = dlopen(path, RTLD_NOW);
227 if (handle == NULL) {
228 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
232 init_fn = (int (*)(void))dlsym(handle, "init_module");
234 if (init_fn == NULL) {
235 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `init_module' found in %s: %s\n", path, dlerror());
244 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
246 struct ldb_module *module;
251 for (i = 0; module_list[i] != NULL; i++) {
252 struct ldb_module *current;
253 const struct ldb_module_ops *ops;
255 ops = ldb_find_module_ops(module_list[i]);
257 if (ldb_try_load_dso(ldb, module_list[i]) == 0) {
258 ops = ldb_find_module_ops(module_list[i]);
263 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
268 current = talloc_zero(ldb, struct ldb_module);
269 if (current == NULL) {
270 return LDB_ERR_OPERATIONS_ERROR;
272 talloc_set_name(current, "ldb_module: %s", module_list[i]);
277 DLIST_ADD(module, current);
283 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
285 while (module && module->ops->init_context == NULL)
286 module = module->next;
288 if (module && module->ops->init_context &&
289 module->ops->init_context(module) != LDB_SUCCESS) {
290 ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n");
291 return LDB_ERR_OPERATIONS_ERROR;
297 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
299 const char **modules = NULL;
302 TALLOC_CTX *mem_ctx = talloc_new(ldb);
304 return LDB_ERR_OPERATIONS_ERROR;
307 /* find out which modules we are requested to activate */
309 /* check if we have a custom module list passd as ldb option */
311 for (i = 0; options[i] != NULL; i++) {
312 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
313 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
318 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
319 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
320 const char * const attrs[] = { "@LIST" , NULL};
321 struct ldb_result *res = NULL;
322 struct ldb_dn *mods_dn;
324 mods_dn = ldb_dn_new(mem_ctx, ldb, "@MODULES");
325 if (mods_dn == NULL) {
326 talloc_free(mem_ctx);
330 ret = ldb_search(ldb, mods_dn, LDB_SCOPE_BASE, "", attrs, &res);
331 talloc_steal(mods_dn, res);
332 if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) {
333 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n");
335 if (ret != LDB_SUCCESS) {
336 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
337 talloc_free(mem_ctx);
340 if (res->count > 1) {
341 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
342 talloc_free(mem_ctx);
346 modules = ldb_modules_list_from_string(ldb, mem_ctx,
347 (const char *)res->msgs[0]->elements[0].values[0].data);
351 talloc_free(mods_dn);
354 if (modules != NULL) {
355 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
356 talloc_free(modules);
357 if (ret != LDB_SUCCESS) {
361 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database\n");
364 return ldb_init_module_chain(ldb, ldb->modules);
368 by using this we allow ldb modules to only implement the functions they care about,
369 which makes writing a module simpler, and makes it more likely to keep working
372 #define FIND_OP(module, op) do { \
373 struct ldb_context *ldb = module->ldb; \
374 module = module->next; \
375 while (module && module->ops->op == NULL) module = module->next; \
376 if (module == NULL) { \
377 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
378 return LDB_ERR_OPERATIONS_ERROR; \
384 helper functions to call the next module in chain
387 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
390 switch (request->operation) {
392 FIND_OP(module, search);
393 ret = module->ops->search(module, request);
396 FIND_OP(module, add);
397 ret = module->ops->add(module, request);
400 FIND_OP(module, modify);
401 ret = module->ops->modify(module, request);
404 FIND_OP(module, del);
405 ret = module->ops->del(module, request);
408 FIND_OP(module, rename);
409 ret = module->ops->rename(module, request);
412 FIND_OP(module, extended);
413 ret = module->ops->extended(module, request);
415 case LDB_SEQUENCE_NUMBER:
416 FIND_OP(module, sequence_number);
417 ret = module->ops->sequence_number(module, request);
420 FIND_OP(module, request);
421 ret = module->ops->request(module, request);
424 if (ret == LDB_SUCCESS) {
427 if (!ldb_errstring(module->ldb)) {
428 /* Set a default error string, to place the blame somewhere */
429 ldb_asprintf_errstring(module->ldb, "error in module %s: %s (%d)", module->ops->name, ldb_strerror(ret), ret);
434 int ldb_next_init(struct ldb_module *module)
436 /* init is different in that it is not an error if modules
437 * do not require initialization */
439 module = module->next;
441 while (module && module->ops->init_context == NULL)
442 module = module->next;
447 return module->ops->init_context(module);
450 int ldb_next_start_trans(struct ldb_module *module)
452 FIND_OP(module, start_transaction);
453 return module->ops->start_transaction(module);
456 int ldb_next_end_trans(struct ldb_module *module)
458 FIND_OP(module, end_transaction);
459 return module->ops->end_transaction(module);
462 int ldb_next_del_trans(struct ldb_module *module)
464 FIND_OP(module, del_transaction);
465 return module->ops->del_transaction(module);