4 Copyright (C) Simo Sorce 2004
6 ** NOTE! The following LGPL license applies to the ldb
7 ** library. This does NOT imply that all of Samba is released
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.
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.
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/>.
27 * Component: ldb modules core
29 * Description: core modules routines
34 #include "ldb_includes.h"
36 #if (_SAMBA_BUILD_ >= 4)
39 #include "dynconfig.h"
42 #define LDB_MODULE_PREFIX "modules:"
43 #define LDB_MODULE_PREFIX_LEN 8
45 void ldb_set_modules_dir(struct ldb_context *ldb, const char *path)
47 talloc_free(ldb->modules_dir);
48 ldb->modules_dir = talloc_strdup(ldb, path);
51 static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
56 trimmed = talloc_strdup(mem_ctx, string);
61 len = strlen(trimmed);
62 for (i = 0; trimmed[i] != '\0'; i++) {
67 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
76 /* modules are called in inverse order on the stack.
77 Lets place them as an admin would think the right order is.
78 Modules order is important */
79 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
81 char **modules = NULL;
86 /* spaces not admitted */
87 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
89 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
93 modules = talloc_realloc(mem_ctx, modules, char *, 2);
95 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
99 talloc_steal(modules, modstr);
102 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
103 while ((p = strrchr(modstr, ',')) != NULL) {
109 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
111 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
118 modules[i + 1] = NULL;
120 m = (const char **)modules;
125 static struct ops_list_entry {
126 const struct ldb_module_ops *ops;
127 struct ops_list_entry *next;
128 } *registered_modules = NULL;
130 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
132 struct ops_list_entry *e;
134 for (e = registered_modules; e; e = e->next) {
135 if (strcmp(e->ops->name, name) == 0)
142 #ifndef STATIC_LIBLDB_MODULES
145 #define LDAP_INIT ldb_ldap_init,
150 #ifdef HAVE_LDB_SQLITE3
151 #define SQLITE3_INIT ldb_sqlite3_init,
156 #define STATIC_LIBLDB_MODULES \
161 ldb_operational_init, \
163 ldb_paged_results_init, \
170 int ldb_global_init(void)
172 static int (*static_init_fns[])(void) = STATIC_LIBLDB_MODULES;
174 static int initialized = 0;
182 for (i = 0; static_init_fns[i]; i++) {
183 if (static_init_fns[i]() == -1)
190 int ldb_register_module(const struct ldb_module_ops *ops)
192 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
194 if (ldb_find_module_ops(ops->name) != NULL)
201 entry->next = registered_modules;
202 registered_modules = entry;
207 int ldb_try_load_dso(struct ldb_context *ldb, const char *name)
211 int (*init_fn) (void);
213 if (ldb->modules_dir == NULL)
216 path = talloc_asprintf(ldb, "%s/%s.%s", ldb->modules_dir, name,
219 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
221 handle = dlopen(path, RTLD_NOW);
222 if (handle == NULL) {
223 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
227 init_fn = (int (*)(void))dlsym(handle, "init_module");
229 if (init_fn == NULL) {
230 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `init_module' found in %s: %s\n", path, dlerror());
239 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
241 struct ldb_module *module;
246 for (i = 0; module_list[i] != NULL; i++) {
247 struct ldb_module *current;
248 const struct ldb_module_ops *ops;
250 ops = ldb_find_module_ops(module_list[i]);
252 if (ldb_try_load_dso(ldb, module_list[i]) == 0) {
253 ops = ldb_find_module_ops(module_list[i]);
258 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
263 current = talloc_zero(ldb, struct ldb_module);
264 if (current == NULL) {
265 return LDB_ERR_OPERATIONS_ERROR;
267 talloc_set_name(current, "ldb_module: %s", module_list[i]);
272 DLIST_ADD(module, current);
278 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
280 while (module && module->ops->init_context == NULL)
281 module = module->next;
283 if (module && module->ops->init_context &&
284 module->ops->init_context(module) != LDB_SUCCESS) {
285 ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n");
286 return LDB_ERR_OPERATIONS_ERROR;
292 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
294 const char **modules = NULL;
297 TALLOC_CTX *mem_ctx = talloc_new(ldb);
299 return LDB_ERR_OPERATIONS_ERROR;
302 /* find out which modules we are requested to activate */
304 /* check if we have a custom module list passd as ldb option */
306 for (i = 0; options[i] != NULL; i++) {
307 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
308 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
313 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
314 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
315 const char * const attrs[] = { "@LIST" , NULL};
316 struct ldb_result *res = NULL;
317 struct ldb_dn *mods_dn;
319 mods_dn = ldb_dn_new(mem_ctx, ldb, "@MODULES");
320 if (mods_dn == NULL) {
321 talloc_free(mem_ctx);
325 ret = ldb_search(ldb, mods_dn, LDB_SCOPE_BASE, "", attrs, &res);
326 talloc_steal(mods_dn, res);
327 if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) {
328 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
330 if (ret != LDB_SUCCESS) {
331 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
332 talloc_free(mem_ctx);
335 if (res->count > 1) {
336 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
337 talloc_free(mem_ctx);
341 modules = ldb_modules_list_from_string(ldb, mem_ctx,
342 (const char *)res->msgs[0]->elements[0].values[0].data);
346 talloc_free(mods_dn);
349 if (modules != NULL) {
350 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
351 talloc_free(modules);
352 if (ret != LDB_SUCCESS) {
356 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database");
359 return ldb_init_module_chain(ldb, ldb->modules);
363 by using this we allow ldb modules to only implement the functions they care about,
364 which makes writing a module simpler, and makes it more likely to keep working
367 #define FIND_OP(module, op) do { \
368 struct ldb_context *ldb = module->ldb; \
369 module = module->next; \
370 while (module && module->ops->op == NULL) module = module->next; \
371 if (module == NULL) { \
372 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
373 return LDB_ERR_OPERATIONS_ERROR; \
379 helper functions to call the next module in chain
382 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
385 switch (request->operation) {
387 FIND_OP(module, search);
388 ret = module->ops->search(module, request);
391 FIND_OP(module, add);
392 ret = module->ops->add(module, request);
395 FIND_OP(module, modify);
396 ret = module->ops->modify(module, request);
399 FIND_OP(module, del);
400 ret = module->ops->del(module, request);
403 FIND_OP(module, rename);
404 ret = module->ops->rename(module, request);
407 FIND_OP(module, extended);
408 ret = module->ops->extended(module, request);
410 case LDB_SEQUENCE_NUMBER:
411 FIND_OP(module, sequence_number);
412 ret = module->ops->sequence_number(module, request);
415 FIND_OP(module, request);
416 ret = module->ops->request(module, request);
419 if (ret == LDB_SUCCESS) {
422 if (!ldb_errstring(module->ldb)) {
423 /* Set a default error string, to place the blame somewhere */
424 ldb_asprintf_errstring(module->ldb, "error in module %s: %s (%d)", module->ops->name, ldb_strerror(ret), ret);
429 int ldb_next_init(struct ldb_module *module)
431 /* init is different in that it is not an error if modules
432 * do not require initialization */
434 module = module->next;
436 while (module && module->ops->init_context == NULL)
437 module = module->next;
442 return module->ops->init_context(module);
445 int ldb_next_start_trans(struct ldb_module *module)
447 FIND_OP(module, start_transaction);
448 return module->ops->start_transaction(module);
451 int ldb_next_end_trans(struct ldb_module *module)
453 FIND_OP(module, end_transaction);
454 return module->ops->end_transaction(module);
457 int ldb_next_del_trans(struct ldb_module *module)
459 FIND_OP(module, del_transaction);
460 return module->ops->del_transaction(module);