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, write to the Free Software
23 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 * Component: ldb modules core
31 * Description: core modules routines
37 #include "ldb/include/includes.h"
39 #if (_SAMBA_BUILD_ >= 4)
41 #include "dynconfig.h"
44 #define LDB_MODULE_PREFIX "modules:"
45 #define LDB_MODULE_PREFIX_LEN 8
47 static char *ldb_modules_strdup_no_spaces(TALLOC_CTX *mem_ctx, const char *string)
52 trimmed = talloc_strdup(mem_ctx, string);
57 len = strlen(trimmed);
58 for (i = 0; trimmed[i] != '\0'; i++) {
63 memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
72 /* modules are called in inverse order on the stack.
73 Lets place them as an admin would think the right order is.
74 Modules order is important */
75 const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
77 char **modules = NULL;
82 /* spaces not admitted */
83 modstr = ldb_modules_strdup_no_spaces(mem_ctx, string);
85 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_strdup_no_spaces()\n");
89 modules = talloc_realloc(mem_ctx, modules, char *, 2);
91 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
95 talloc_steal(modules, modstr);
98 /* The str*r*chr walks backwards: This is how we get the inverse order mentioned above */
99 while ((p = strrchr(modstr, ',')) != NULL) {
105 modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
107 ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
114 modules[i + 1] = NULL;
116 m = (const char **)modules;
121 static struct ops_list_entry {
122 const struct ldb_module_ops *ops;
123 struct ops_list_entry *next;
124 } *registered_modules = NULL;
126 static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
128 struct ops_list_entry *e;
130 for (e = registered_modules; e; e = e->next) {
131 if (strcmp(e->ops->name, name) == 0)
138 #ifndef STATIC_ldb_MODULES
141 #define LDAP_INIT ldb_ldap_init,
146 #ifdef HAVE_LDB_SQLITE3
147 #define SQLITE3_INIT ldb_sqlite3_init,
152 #define STATIC_ldb_MODULES \
157 ldb_operational_init, \
159 ldb_objectclass_init, \
160 ldb_paged_results_init, \
167 int ldb_global_init(void)
169 static int (*static_init_fns[])(void) = STATIC_ldb_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 int ldb_try_load_dso(struct ldb_context *ldb, const char *name)
208 int (*init_fn) (void);
212 if (getenv("LD_LDB_MODULE_PATH") != NULL) {
213 modulesdir = talloc_strdup(ldb, getenv("LD_LDB_MODULE_PATH"));
216 modulesdir = talloc_asprintf(ldb, "%s/ldb", dyn_MODULESDIR);
218 modulesdir = talloc_strdup(ldb, MODULESDIR);
222 path = talloc_asprintf(ldb, "%s/%s.%s", modulesdir, name, SHLIBEXT);
224 talloc_free(modulesdir);
226 ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
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());
234 init_fn = (int (*)(void))dlsym(handle, "init_module");
236 if (init_fn == NULL) {
237 ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `init_module' found in %s: %s\n", path, dlerror());
245 ldb_debug(ldb, LDB_DEBUG_TRACE, "no dlopen() - not trying to load %s module\n", name);
250 int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
252 struct ldb_module *module;
257 for (i = 0; module_list[i] != NULL; i++) {
258 struct ldb_module *current;
259 const struct ldb_module_ops *ops;
261 ops = ldb_find_module_ops(module_list[i]);
263 if (ldb_try_load_dso(ldb, module_list[i]) == 0) {
264 ops = ldb_find_module_ops(module_list[i]);
269 ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n",
274 current = talloc_zero(ldb, struct ldb_module);
275 if (current == NULL) {
276 return LDB_ERR_OPERATIONS_ERROR;
278 talloc_set_name(current, "ldb_module: %s", module_list[i]);
283 DLIST_ADD(module, current);
289 int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module)
291 while (module && module->ops->init_context == NULL)
292 module = module->next;
294 if (module && module->ops->init_context &&
295 module->ops->init_context(module) != LDB_SUCCESS) {
296 ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n");
297 return LDB_ERR_OPERATIONS_ERROR;
303 int ldb_load_modules(struct ldb_context *ldb, const char *options[])
305 const char **modules = NULL;
308 TALLOC_CTX *mem_ctx = talloc_new(ldb);
310 return LDB_ERR_OPERATIONS_ERROR;
313 /* find out which modules we are requested to activate */
315 /* check if we have a custom module list passd as ldb option */
317 for (i = 0; options[i] != NULL; i++) {
318 if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
319 modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
324 /* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
325 if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) {
326 const char * const attrs[] = { "@LIST" , NULL};
327 struct ldb_result *res = NULL;
328 struct ldb_dn *mods_dn;
330 mods_dn = ldb_dn_explode(mem_ctx, "@MODULES");
331 if (mods_dn == NULL) {
332 talloc_free(mem_ctx);
336 ret = ldb_search(ldb, mods_dn, LDB_SCOPE_BASE, "", attrs, &res);
337 talloc_steal(mods_dn, res);
338 if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) {
339 ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n");
341 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 if (res->count > 1) {
347 ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
348 talloc_free(mem_ctx);
352 modules = ldb_modules_list_from_string(ldb, mem_ctx,
353 (const char *)res->msgs[0]->elements[0].values[0].data);
357 talloc_free(mods_dn);
360 if (modules != NULL) {
361 ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
362 talloc_free(modules);
363 if (ret != LDB_SUCCESS) {
367 ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database\n");
370 return ldb_init_module_chain(ldb, ldb->modules);
374 by using this we allow ldb modules to only implement the functions they care about,
375 which makes writing a module simpler, and makes it more likely to keep working
378 #define FIND_OP(module, op) do { \
379 struct ldb_context *ldb = module->ldb; \
380 module = module->next; \
381 while (module && module->ops->op == NULL) module = module->next; \
382 if (module == NULL) { \
383 ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
384 return LDB_ERR_OPERATIONS_ERROR; \
390 helper functions to call the next module in chain
393 int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
395 switch (request->operation) {
397 FIND_OP(module, search);
398 return module->ops->search(module, request);
400 FIND_OP(module, add);
401 return module->ops->add(module, request);
403 FIND_OP(module, modify);
404 return module->ops->modify(module, request);
406 FIND_OP(module, del);
407 return module->ops->del(module, request);
409 FIND_OP(module, rename);
410 return module->ops->rename(module, request);
411 case LDB_SEQUENCE_NUMBER:
412 FIND_OP(module, sequence_number);
413 return module->ops->sequence_number(module, request);
415 FIND_OP(module, request);
416 return module->ops->request(module, request);
420 int ldb_next_init(struct ldb_module *module)
422 /* init is different in that it is not an error if modules
423 * do not require initialization */
425 module = module->next;
427 while (module && module->ops->init_context == NULL)
428 module = module->next;
433 return module->ops->init_context(module);
436 int ldb_next_start_trans(struct ldb_module *module)
438 FIND_OP(module, start_transaction);
439 return module->ops->start_transaction(module);
442 int ldb_next_end_trans(struct ldb_module *module)
444 FIND_OP(module, end_transaction);
445 return module->ops->end_transaction(module);
448 int ldb_next_del_trans(struct ldb_module *module)
450 FIND_OP(module, del_transaction);
451 return module->ops->del_transaction(module);