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)
40 #define LDB_MODULE_PREFIX "modules:"
41 #define LDB_MODULE_PREFIX_LEN 8
43 void ldb_set_modules_dir(struct ldb_context *ldb, const char *path)
45 talloc_free(ldb->modules_dir);
46 ldb->modules_dir = talloc_strdup(ldb, path);
49 static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
54 trimmed = talloc_strdup(mem_ctx, string);
59 len = strlen(trimmed);
60 for (i = 0; trimmed[i] != '\0'; i++) {
65 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
74 /* modules are called in inverse order on the stack.
75 Lets place them as an admin would think the right order is.
76 Modules order is important */
77 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
79 char **modules = NULL;
84 /* spaces not admitted */
85 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
87 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
91 modules = talloc_realloc(mem_ctx, modules, char *, 2);
93 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
97 talloc_steal(modules, modstr);
100 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
101 while ((p = strrchr(modstr, ',')) != NULL) {
107 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
109 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
116 modules[i + 1] = NULL;
118 m = (const char **)modules;
123 static struct backends_list_entry {
124 struct ldb_backend_ops *ops;
125 struct backends_list_entry *prev, *next;
126 } *ldb_backends = NULL;
128 static struct ops_list_entry {
129 const struct ldb_module_ops *ops;
130 struct ops_list_entry *next;
131 } *registered_modules = NULL;
133 static const struct ldb_builtins {
134 const struct ldb_backend_ops *backend_ops;
135 const struct ldb_module_ops *module_ops;
138 static ldb_connect_fn ldb_find_backend(const char *url)
140 struct backends_list_entry *backend;
143 for (i = 0; builtins[i].backend_ops || builtins[i].module_ops; i++) {
144 if (builtins[i].backend_ops == NULL) continue;
146 if (strncmp(builtins[i].backend_ops->name, url,
147 strlen(builtins[i].backend_ops->name)) == 0) {
148 return builtins[i].backend_ops->connect_fn;
152 for (backend = ldb_backends; backend; backend = backend->next) {
153 if (strncmp(backend->ops->name, url,
154 strlen(backend->ops->name)) == 0) {
155 return backend->ops->connect_fn;
163 register a new ldb backend
165 int ldb_register_backend(const char *url_prefix, ldb_connect_fn connectfn)
167 struct ldb_backend_ops *backend;
168 struct backends_list_entry *entry;
170 backend = talloc(talloc_autofree_context(), struct ldb_backend_ops);
171 if (!backend) return LDB_ERR_OPERATIONS_ERROR;
173 entry = talloc(talloc_autofree_context(), struct backends_list_entry);
175 talloc_free(backend);
176 return LDB_ERR_OPERATIONS_ERROR;
179 if (ldb_find_backend(url_prefix)) {
183 /* Maybe check for duplicity here later on? */
185 backend->name = talloc_strdup(backend, url_prefix);
186 backend->connect_fn = connectfn;
187 entry->ops = backend;
188 DLIST_ADD(ldb_backends, entry);
194 Return the ldb module form of a database.
195 The URL can either be one of the following forms
199 flags is made up of LDB_FLG_*
201 the options are passed uninterpreted to the backend, and are
204 This allows modules to get at only the backend module, for example where a
205 module may wish to direct certain requests at a particular backend.
207 int ldb_connect_backend(struct ldb_context *ldb,
209 const char *options[],
210 struct ldb_module **backend_module)
216 if (strchr(url, ':') != NULL) {
217 backend = talloc_strndup(ldb, url, strchr(url, ':')-url);
220 backend = talloc_strdup(ldb, "tdb");
223 fn = ldb_find_backend(backend);
226 struct ldb_backend_ops *ops;
227 char *symbol_name = talloc_asprintf(ldb, "ldb_%s_backend_ops", backend);
228 if (symbol_name == NULL) {
229 return LDB_ERR_OPERATIONS_ERROR;
231 ops = ldb_dso_load_symbol(ldb, backend, symbol_name);
233 fn = ops->connect_fn;
235 talloc_free(symbol_name);
238 talloc_free(backend);
241 ldb_debug(ldb, LDB_DEBUG_FATAL,
242 "Unable to find backend for '%s'\n", url);
243 return LDB_ERR_OTHER;
246 ret = fn(ldb, url, ldb->flags, options, backend_module);
248 if (ret != LDB_SUCCESS) {
249 ldb_debug(ldb, LDB_DEBUG_ERROR,
250 "Failed to connect to '%s'\n", url);
256 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
258 struct ops_list_entry *e;
261 for (i = 0; builtins[i].backend_ops || builtins[i].module_ops; i++) {
262 if (builtins[i].module_ops == NULL) continue;
264 if (strcmp(builtins[i].module_ops->name, name) == 0)
265 return builtins[i].module_ops;
268 for (e = registered_modules; e; e = e->next) {
269 if (strcmp(e->ops->name, name) == 0)
277 int ldb_register_module(const struct ldb_module_ops *ops)
279 struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
281 if (ldb_find_module_ops(ops->name) != NULL)
288 entry->next = registered_modules;
289 registered_modules = entry;
294 void *ldb_dso_load_symbol(struct ldb_context *ldb, const char *name,
301 if (ldb->modules_dir == NULL)
304 path = talloc_asprintf(ldb, "%s/%s.%s", ldb->modules_dir, name,
307 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
309 handle = dlopen(path, RTLD_NOW);
310 if (handle == NULL) {
311 ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
315 sym = (int (*)(void))dlsym(handle, symbol);
318 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `%s' found in %s: %s\n", symbol, path, dlerror());
327 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
329 struct ldb_module *module;
334 for (i = 0; module_list[i] != NULL; i++) {
335 struct ldb_module *current;
336 const struct ldb_module_ops *ops;
338 ops = ldb_find_module_ops(module_list[i]);
340 char *symbol_name = talloc_asprintf(ldb, "ldb_%s_module_ops",
342 if (symbol_name == NULL) {
343 return LDB_ERR_OPERATIONS_ERROR;
345 ops = ldb_dso_load_symbol(ldb, module_list[i], symbol_name);
346 talloc_free(symbol_name);
350 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
355 current = talloc_zero(ldb, struct ldb_module);
356 if (current == NULL) {
357 return LDB_ERR_OPERATIONS_ERROR;
359 talloc_set_name(current, "ldb_module: %s", module_list[i]);
364 DLIST_ADD(module, current);
370 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
372 while (module && module->ops->init_context == NULL)
373 module = module->next;
375 /* init is different in that it is not an error if modules
376 * do not require initialization */
379 int ret = module->ops->init_context(module);
380 if (ret != LDB_SUCCESS) {
381 ldb_debug(ldb, LDB_DEBUG_FATAL, "module %s initialization failed\n", module->ops->name);
389 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
391 const char **modules = NULL;
394 TALLOC_CTX *mem_ctx = talloc_new(ldb);
396 return LDB_ERR_OPERATIONS_ERROR;
399 /* find out which modules we are requested to activate */
401 /* check if we have a custom module list passd as ldb option */
403 for (i = 0; options[i] != NULL; i++) {
404 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
405 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
410 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
411 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
412 const char * const attrs[] = { "@LIST" , NULL};
413 struct ldb_result *res = NULL;
414 struct ldb_dn *mods_dn;
416 mods_dn = ldb_dn_new(mem_ctx, ldb, "@MODULES");
417 if (mods_dn == NULL) {
418 talloc_free(mem_ctx);
422 ret = ldb_search_exp_fmt(ldb, mods_dn, &res, mods_dn, LDB_SCOPE_BASE, attrs, "@LIST=*");
424 if (ret == LDB_ERR_NO_SUCH_OBJECT) {
425 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
426 } else if (ret != LDB_SUCCESS) {
427 ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
428 talloc_free(mem_ctx);
431 const char *module_list;
432 if (res->count == 0) {
433 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
434 } else if (res->count > 1) {
435 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
436 talloc_free(mem_ctx);
439 module_list = ldb_msg_find_attr_as_string(res->msgs[0], "@LIST", NULL);
441 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db");
443 modules = ldb_modules_list_from_string(ldb, mem_ctx,
448 talloc_free(mods_dn);
451 if (modules != NULL) {
452 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
453 if (ret != LDB_SUCCESS) {
454 talloc_free(mem_ctx);
458 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database");
461 ret = ldb_init_module_chain(ldb, ldb->modules);
462 talloc_free(mem_ctx);
467 by using this we allow ldb modules to only implement the functions they care about,
468 which makes writing a module simpler, and makes it more likely to keep working
471 #define FIND_OP(module, op) do { \
472 struct ldb_context *ldb = module->ldb; \
473 module = module->next; \
474 while (module && module->ops->op == NULL) module = module->next; \
475 if (module == NULL) { \
476 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
477 return LDB_ERR_OPERATIONS_ERROR; \
483 helper functions to call the next module in chain
486 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
489 switch (request->operation) {
491 FIND_OP(module, search);
492 ret = module->ops->search(module, request);
495 FIND_OP(module, add);
496 ret = module->ops->add(module, request);
499 FIND_OP(module, modify);
500 ret = module->ops->modify(module, request);
503 FIND_OP(module, del);
504 ret = module->ops->del(module, request);
507 FIND_OP(module, rename);
508 ret = module->ops->rename(module, request);
511 FIND_OP(module, extended);
512 ret = module->ops->extended(module, request);
514 case LDB_SEQUENCE_NUMBER:
515 FIND_OP(module, sequence_number);
516 ret = module->ops->sequence_number(module, request);
519 FIND_OP(module, request);
520 ret = module->ops->request(module, request);
523 if (ret == LDB_SUCCESS) {
526 if (!ldb_errstring(module->ldb)) {
527 /* Set a default error string, to place the blame somewhere */
528 ldb_asprintf_errstring(module->ldb, "error in module %s: %s (%d)", module->ops->name, ldb_strerror(ret), ret);
533 int ldb_next_init(struct ldb_module *module)
535 module = module->next;
537 return ldb_init_module_chain(module->ldb, module);
540 int ldb_next_start_trans(struct ldb_module *module)
542 FIND_OP(module, start_transaction);
543 return module->ops->start_transaction(module);
546 int ldb_next_end_trans(struct ldb_module *module)
548 FIND_OP(module, end_transaction);
549 return module->ops->end_transaction(module);
552 int ldb_next_del_trans(struct ldb_module *module)
554 FIND_OP(module, del_transaction);
555 return module->ops->del_transaction(module);
558 #ifndef STATIC_LIBLDB_MODULES
561 #define LDAP_BACKEND LDB_BACKEND(ldap), LDB_BACKEND(ldapi), LDB_BACKEND(ldaps),
566 #ifdef HAVE_LDB_SQLITE3
567 #define SQLITE3_BACKEND LDB_BACKEND(sqlite3),
569 #define SQLITE3_BACKEND
572 #define STATIC_LIBLDB_MODULES \
576 LDB_MODULE(operational), \
577 LDB_MODULE(rdn_name), \
578 LDB_MODULE(paged_results), \
579 LDB_MODULE(server_sort), \
585 * this is a bit hacked, as STATIC_LIBLDB_MODULES contains ','
586 * between the elements and we want to autogenerate the
587 * extern struct declarations, so we do some hacks and let the
588 * ',' appear in an unused function prototype.
591 #define NULL LDB_MODULE(NULL),
593 #define LDB_BACKEND(name) \
595 extern const struct ldb_backend_ops ldb_ ## name ## _backend_ops;\
596 extern void ldb_noop ## name (int
597 #define LDB_MODULE(name) \
599 extern const struct ldb_module_ops ldb_ ## name ## _module_ops;\
600 extern void ldb_noop ## name (int
602 extern void ldb_start_noop(int,
603 STATIC_LIBLDB_MODULES
608 .backend_ops = (void *)0, \
609 .module_ops = (void *)0 \
613 #define LDB_BACKEND(name) { \
614 .backend_ops = &ldb_ ## name ## _backend_ops, \
615 .module_ops = (void *)0 \
618 #define LDB_MODULE(name) { \
619 .backend_ops = (void *)0, \
620 .module_ops = &ldb_ ## name ## _module_ops \
623 static const struct ldb_builtins builtins[] = {
624 STATIC_LIBLDB_MODULES