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)
41 #define LDB_MODULE_PREFIX "modules:"
42 #define LDB_MODULE_PREFIX_LEN 8
44 void ldb_set_modules_dir(struct ldb_context *ldb, const char *path)
46 talloc_free(ldb->modules_dir);
47 ldb->modules_dir = talloc_strdup(ldb, path);
50 static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
55 trimmed = talloc_strdup(mem_ctx, string);
60 len = strlen(trimmed);
61 for (i = 0; trimmed[i] != '\0'; i++) {
66 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
75 /* modules are called in inverse order on the stack.
76 Lets place them as an admin would think the right order is.
77 Modules order is important */
78 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
80 char **modules = NULL;
85 /* spaces not admitted */
86 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
88 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
92 modules = talloc_realloc(mem_ctx, modules, char *, 2);
94 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
98 talloc_steal(modules, modstr);
101 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
102 while ((p = strrchr(modstr, ',')) != NULL) {
108 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
110 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
117 modules[i + 1] = NULL;
119 m = (const char **)modules;
124 static struct ops_list_entry {
125 const struct ldb_module_ops *ops;
126 struct ops_list_entry *next;
127 } *registered_modules = NULL;
129 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
131 struct ops_list_entry *e;
133 for (e = registered_modules; e; e = e->next) {
134 if (strcmp(e->ops->name, name) == 0)
141 #ifndef STATIC_LIBLDB_MODULES
144 #define LDAP_INIT ldb_ldap_init,
149 #ifdef HAVE_LDB_SQLITE3
150 #define SQLITE3_INIT ldb_sqlite3_init,
155 #define STATIC_LIBLDB_MODULES \
159 ldb_operational_init, \
161 ldb_paged_results_init, \
167 int ldb_global_init(void)
169 int (*static_init_fns[])(void) = { STATIC_LIBLDB_MODULES };
171 static int initialized = 0;
179 for (i = 0; static_init_fns[i]; i++) {
180 if (static_init_fns[i]() == -1)
187 int ldb_register_module(const struct ldb_module_ops *ops)
189 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
191 if (ldb_find_module_ops(ops->name) != NULL)
198 entry->next = registered_modules;
199 registered_modules = entry;
204 void *ldb_dso_load_symbol(struct ldb_context *ldb, const char *name,
211 if (ldb->modules_dir == NULL)
214 path = talloc_asprintf(ldb, "%s/%s.%s", ldb->modules_dir, name,
217 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
219 handle = dlopen(path, RTLD_NOW);
220 if (handle == NULL) {
221 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
225 sym = (int (*)(void))dlsym(handle, symbol);
228 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `%s' found in %s: %s\n", symbol, path, dlerror());
237 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
239 struct ldb_module *module;
244 for (i = 0; module_list[i] != NULL; i++) {
245 struct ldb_module *current;
246 const struct ldb_module_ops *ops;
248 ops = ldb_find_module_ops(module_list[i]);
250 int (*init_fn) (void);
252 init_fn = ldb_dso_load_symbol(ldb, module_list[i],
254 if (init_fn != NULL && init_fn() == 0) {
255 ops = ldb_find_module_ops(module_list[i]);
260 ops = ldb_dso_load_symbol(ldb, module_list[i],
265 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
270 current = talloc_zero(ldb, struct ldb_module);
271 if (current == NULL) {
272 return LDB_ERR_OPERATIONS_ERROR;
274 talloc_set_name(current, "ldb_module: %s", module_list[i]);
279 DLIST_ADD(module, current);
285 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
287 while (module && module->ops->init_context == NULL)
288 module = module->next;
290 /* init is different in that it is not an error if modules
291 * do not require initialization */
294 int ret = module->ops->init_context(module);
295 if (ret != LDB_SUCCESS) {
296 ldb_debug(ldb, LDB_DEBUG_FATAL, "module %s initialization failed\n", module->ops->name);
304 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
306 const char **modules = NULL;
309 TALLOC_CTX *mem_ctx = talloc_new(ldb);
311 return LDB_ERR_OPERATIONS_ERROR;
314 /* find out which modules we are requested to activate */
316 /* check if we have a custom module list passd as ldb option */
318 for (i = 0; options[i] != NULL; i++) {
319 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
320 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
325 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
326 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
327 const char * const attrs[] = { "@LIST" , NULL};
328 struct ldb_result *res = NULL;
329 struct ldb_dn *mods_dn;
331 mods_dn = ldb_dn_new(mem_ctx, ldb, "@MODULES");
332 if (mods_dn == NULL) {
333 talloc_free(mem_ctx);
337 ret = ldb_search_exp_fmt(ldb, mods_dn, &res, mods_dn, LDB_SCOPE_BASE, attrs, "@LIST=*");
339 if (ret == LDB_ERR_NO_SUCH_OBJECT) {
340 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
341 } else if (ret != LDB_SUCCESS) {
342 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
343 talloc_free(mem_ctx);
346 const char *module_list;
347 if (res->count == 0) {
348 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
349 } else if (res->count > 1) {
350 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
351 talloc_free(mem_ctx);
354 module_list = ldb_msg_find_attr_as_string(res->msgs[0], "@LIST", NULL);
356 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
358 modules = ldb_modules_list_from_string(ldb, mem_ctx,
363 talloc_free(mods_dn);
366 if (modules != NULL) {
367 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
368 if (ret != LDB_SUCCESS) {
369 talloc_free(mem_ctx);
373 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database");
376 ret = ldb_init_module_chain(ldb, ldb->modules);
377 talloc_free(mem_ctx);
382 by using this we allow ldb modules to only implement the functions they care about,
383 which makes writing a module simpler, and makes it more likely to keep working
386 #define FIND_OP(module, op) do { \
387 struct ldb_context *ldb = module->ldb; \
388 module = module->next; \
389 while (module && module->ops->op == NULL) module = module->next; \
390 if (module == NULL) { \
391 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
392 return LDB_ERR_OPERATIONS_ERROR; \
398 helper functions to call the next module in chain
401 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
404 switch (request->operation) {
406 FIND_OP(module, search);
407 ret = module->ops->search(module, request);
410 FIND_OP(module, add);
411 ret = module->ops->add(module, request);
414 FIND_OP(module, modify);
415 ret = module->ops->modify(module, request);
418 FIND_OP(module, del);
419 ret = module->ops->del(module, request);
422 FIND_OP(module, rename);
423 ret = module->ops->rename(module, request);
426 FIND_OP(module, extended);
427 ret = module->ops->extended(module, request);
429 case LDB_SEQUENCE_NUMBER:
430 FIND_OP(module, sequence_number);
431 ret = module->ops->sequence_number(module, request);
434 FIND_OP(module, request);
435 ret = module->ops->request(module, request);
438 if (ret == LDB_SUCCESS) {
441 if (!ldb_errstring(module->ldb)) {
442 /* Set a default error string, to place the blame somewhere */
443 ldb_asprintf_errstring(module->ldb, "error in module %s: %s (%d)", module->ops->name, ldb_strerror(ret), ret);
448 int ldb_next_init(struct ldb_module *module)
450 module = module->next;
452 return ldb_init_module_chain(module->ldb, module);
455 int ldb_next_start_trans(struct ldb_module *module)
457 FIND_OP(module, start_transaction);
458 return module->ops->start_transaction(module);
461 int ldb_next_end_trans(struct ldb_module *module)
463 FIND_OP(module, end_transaction);
464 return module->ops->end_transaction(module);
467 int ldb_next_del_trans(struct ldb_module *module)
469 FIND_OP(module, del_transaction);
470 return module->ops->del_transaction(module);