1 files changed, 442 insertions, 0 deletions
diff --git a/source3/lib/ldb/common/ldb_modules.c b/source3/lib/ldb/common/ldb_modules.c
new file mode 100644
index 0000000000..06a8a4bcf6
--- /dev/null
+++ b/source3/lib/ldb/common/ldb_modules.c
@@ -0,0 +1,442 @@
+
+/* 
+   ldb database library
+
+   Copyright (C) Simo Sorce  2004
+
+     ** NOTE! The following LGPL license applies to the ldb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+   
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb modules core
+ *
+ *  Description: core modules routines
+ *
+ *  Author: Simo Sorce
+ */
+
+#include "includes.h"
+#include "ldb/include/includes.h"
+
+#if (_SAMBA_BUILD_ >= 4)
+#include "build.h"
+#include "dynconfig.h"
+#endif
+
+#define LDB_MODULE_PREFIX	"modules:"
+#define LDB_MODULE_PREFIX_LEN	8
+
+static char *talloc_strdup_no_spaces(struct ldb_context *ldb, const char *string)
+{
+	int i, len;
+	char *trimmed;
+
+	trimmed = talloc_strdup(ldb, string);
+	if (!trimmed) {
+		ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in talloc_strdup_trim_spaces()\n");
+		return NULL;
+	}
+
+	len = strlen(trimmed);
+	for (i = 0; trimmed[i] != '\0'; i++) {
+		switch (trimmed[i]) {
+		case ' ':
+		case '\t':
+		case '\n':
+			memmove(&trimmed[i], &trimmed[i + 1], len -i -1);
+			break;
+		}
+	}
+
+	return trimmed;
+}
+
+
+/* modules are called in inverse order on the stack.
+   Lets place them as an admin would think the right order is.
+   Modules order is important */
+const char **ldb_modules_list_from_string(struct ldb_context *ldb, TALLOC_CTX *mem_ctx, const char *string)
+{
+	char **modules = NULL;
+	const char **m;
+	char *modstr, *p;
+	int i;
+
+	/* spaces not admitted */
+	modstr = talloc_strdup_no_spaces(mem_ctx, string);
+	if ( ! modstr) {
+		return NULL;
+	}
+
+	modules = talloc_realloc(mem_ctx, modules, char *, 2);
+	if ( ! modules ) {
+		ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
+		talloc_free(modstr);
+		return NULL;
+	}
+	talloc_steal(modules, modstr);
+
+	i = 0;
+	/* The str*r*chr walks backwards:  This is how we get the inverse order mentioned above */
+	while ((p = strrchr(modstr, ',')) != NULL) {
+		*p = '\0';
+		p++;
+		modules[i] = p;
+
+		i++;
+		modules = talloc_realloc(mem_ctx, modules, char *, i + 2);
+		if ( ! modules ) {
+			ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_modules_list_from_string()\n");
+			return NULL;
+		}
+
+	}
+	modules[i] = modstr;
+
+	modules[i + 1] = NULL;
+
+	m = (const char **)modules;
+
+	return m;
+}
+
+static struct ops_list_entry {
+	const struct ldb_module_ops *ops;
+	struct ops_list_entry *next;	
+} *registered_modules = NULL;
+
+static const struct ldb_module_ops *ldb_find_module_ops(const char *name)
+{
+	struct ops_list_entry *e;
+ 
+	for (e = registered_modules; e; e = e->next) {
+ 		if (strcmp(e->ops->name, name) == 0) 
+			return e->ops;
+	}
+
+	return NULL;
+}
+
+#ifndef STATIC_ldb_MODULES
+
+#ifdef HAVE_LDAP
+#define LDAP_INIT ldb_ldap_init,
+#else
+#define LDAP_INIT
+#endif
+
+#ifdef HAVE_SQLITE3
+#define SQLITE3_INIT ldb_sqlite3_init,
+#else
+#define SQLITE3_INIT
+#endif
+
+#define STATIC_ldb_MODULES \
+	{	\
+		LDAP_INIT \
+		SQLITE3_INIT \
+		ldb_tdb_init, 	\
+		ldb_schema_init,	\
+		ldb_operational_init,	\
+		ldb_rdn_name_init,	\
+		ldb_objectclass_init,	\
+		ldb_paged_results_init,	\
+		ldb_sort_init,		\
+		NULL			\
+	}
+#endif
+
+int ldb_global_init(void)
+{
+	static int (*static_init_fns[])(void) = STATIC_ldb_MODULES;
+
+	static int initialized = 0;
+	int ret = 0, i;
+
+	if (initialized) 
+		return 0;
+
+	initialized = 1;
+	
+	for (i = 0; static_init_fns[i]; i++) {
+		if (static_init_fns[i]() == -1)
+			ret = -1;
+	}
+
+	return ret;
+}
+
+int ldb_register_module(const struct ldb_module_ops *ops)
+{
+	struct ops_list_entry *entry = talloc(talloc_autofree_context(), struct ops_list_entry);
+
+	if (ldb_find_module_ops(ops->name) != NULL)
+		return -1;
+
+	if (entry == NULL)
+		return -1;
+
+	entry->ops = ops;
+	entry->next = registered_modules;
+	registered_modules = entry;
+
+	return 0;
+}
+
+int ldb_try_load_dso(struct ldb_context *ldb, const char *name)
+{
+	char *path;
+	void *handle;
+	int (*init_fn) (void);
+
+#ifdef HAVE_DLOPEN
+#ifdef _SAMBA_BUILD_
+	path = talloc_asprintf(ldb, "%s/ldb/%s.%s", dyn_MODULESDIR, name, dyn_SHLIBEXT);
+#else
+	path = talloc_asprintf(ldb, "%s/%s.%s", MODULESDIR, name, SHLIBEXT);
+#endif
+
+	ldb_debug(ldb, LDB_DEBUG_TRACE, "trying to load %s from %s\n", name, path);
+
+	handle = dlopen(path, 0);
+	if (handle == NULL) {
+		ldb_debug(ldb, LDB_DEBUG_WARNING, "unable to load %s from %s: %s\n", name, path, dlerror());
+		return -1;
+	}
+
+	init_fn = (int (*)(void))dlsym(handle, "init_module");
+
+	if (init_fn == NULL) {
+		ldb_debug(ldb, LDB_DEBUG_ERROR, "no symbol `init_module' found in %s: %s\n", path, dlerror());
+		return -1;
+	}
+
+	talloc_free(path);
+
+	return init_fn();
+#else
+	ldb_debug(ldb, LDB_DEBUG_TRACE, "no dlopen() - not trying to load %s module\n", name);
+	return -1;
+#endif
+}
+
+int ldb_load_modules_list(struct ldb_context *ldb, const char **module_list, struct ldb_module *backend, struct ldb_module **out)
+{
+	struct ldb_module *module;
+	int i;
+	
+	module = backend;
+
+	for (i = 0; module_list[i] != NULL; i++) {
+		struct ldb_module *current;
+		const struct ldb_module_ops *ops;
+		
+		ops = ldb_find_module_ops(module_list[i]);
+		if (ops == NULL) {
+			if (ldb_try_load_dso(ldb, module_list[i]) == 0) {
+				ops = ldb_find_module_ops(module_list[i]);
+			}
+		}
+		
+		if (ops == NULL) {
+			ldb_debug(ldb, LDB_DEBUG_WARNING, "WARNING: Module [%s] not found\n", 
+				  module_list[i]);
+			continue;
+		}
+		
+		current = talloc_zero(ldb, struct ldb_module);
+		if (current == NULL) {
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		
+		current->ldb = ldb;
+		current->ops = ops;
+		
+		DLIST_ADD(module, current);
+	}
+	*out = module;
+	return LDB_SUCCESS;
+}
+
+int ldb_init_module_chain(struct ldb_context *ldb, struct ldb_module *module) 
+{
+	while (module && module->ops->init_context == NULL) 
+		module = module->next;
+
+	if (module && module->ops->init_context &&
+		module->ops->init_context(module) != LDB_SUCCESS) {
+		ldb_debug(ldb, LDB_DEBUG_FATAL, "module initialization failed\n");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	return LDB_SUCCESS;
+}
+
+int ldb_load_modules(struct ldb_context *ldb, const char *options[])
+{
+	const char **modules = NULL;
+	int i;
+	int ret;
+	TALLOC_CTX *mem_ctx = talloc_new(ldb);
+	if (!mem_ctx) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/* find out which modules we are requested to activate */
+
+	/* check if we have a custom module list passd as ldb option */
+	if (options) {
+		for (i = 0; options[i] != NULL; i++) {
+			if (strncmp(options[i], LDB_MODULE_PREFIX, LDB_MODULE_PREFIX_LEN) == 0) {
+				modules = ldb_modules_list_from_string(ldb, mem_ctx, &options[i][LDB_MODULE_PREFIX_LEN]);
+			}
+		}
+	}
+
+	/* if not overloaded by options and the backend is not ldap try to load the modules list from ldb */
+	if ((modules == NULL) && (strcmp("ldap", ldb->modules->ops->name) != 0)) { 
+		const char * const attrs[] = { "@LIST" , NULL};
+		struct ldb_result *res = NULL;
+		struct ldb_dn *mods_dn;
+
+		mods_dn = ldb_dn_explode(mem_ctx, "@MODULES");
+		if (mods_dn == NULL) {
+			talloc_free(mem_ctx);
+			return -1;
+		}
+
+		ret = ldb_search(ldb, mods_dn, LDB_SCOPE_BASE, "", attrs, &res);
+		if (res) talloc_steal(mods_dn, res);
+		if (ret == LDB_SUCCESS && (res->count == 0 || res->msgs[0]->num_elements == 0)) {
+			ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n");
+		} else {
+			if (ret != LDB_SUCCESS) {
+				ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
+				talloc_free(mem_ctx);
+				return -1;
+			}
+			if (res->count > 1) {
+				ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found (%d), bailing out\n", res->count);
+				talloc_free(mem_ctx);
+				return -1;
+			}
+
+			modules = ldb_modules_list_from_string(ldb, mem_ctx,
+							       (const char *)res->msgs[0]->elements[0].values[0].data);
+
+		}
+
+		talloc_free(mods_dn);
+	}
+
+	if (modules != NULL) {
+		ret = ldb_load_modules_list(ldb, modules, ldb->modules, &ldb->modules);
+		talloc_free(modules);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	} else {
+		ldb_debug(ldb, LDB_DEBUG_TRACE, "No modules specified for this database\n");
+	}
+
+	return ldb_init_module_chain(ldb, ldb->modules);
+}
+
+/*
+  by using this we allow ldb modules to only implement the functions they care about,
+  which makes writing a module simpler, and makes it more likely to keep working
+  when ldb is extended
+*/
+#define FIND_OP(module, op) do { \
+	struct ldb_context *ldb = module->ldb; \
+	module = module->next; \
+	while (module && module->ops->op == NULL) module = module->next; \
+	if (module == NULL) { \
+		ldb_asprintf_errstring(ldb, "Unable to find backend operation for " #op ); \
+		return LDB_ERR_OPERATIONS_ERROR;	\
+	}						\
+} while (0)
+
+
+/*
+   helper functions to call the next module in chain
+*/
+
+int ldb_next_request(struct ldb_module *module, struct ldb_request *request)
+{
+	switch (request->operation) {
+	case LDB_SEARCH:
+		FIND_OP(module, search);
+		return module->ops->search(module, request);
+	case LDB_ADD:
+		FIND_OP(module, add);
+		return module->ops->add(module, request);
+	case LDB_MODIFY:
+		FIND_OP(module, modify);
+		return module->ops->modify(module, request);
+	case LDB_DELETE:
+		FIND_OP(module, del);
+		return module->ops->del(module, request);
+	case LDB_RENAME:
+		FIND_OP(module, rename);
+		return module->ops->rename(module, request);
+	case LDB_SEQUENCE_NUMBER:
+		FIND_OP(module, sequence_number);
+		return module->ops->sequence_number(module, request);
+	default:
+		FIND_OP(module, request);
+		return module->ops->request(module, request);
+	}
+}
+
+int ldb_next_init(struct ldb_module *module)
+{
+	/* init is different in that it is not an error if modules
+	 * do not require initialization */
+
+	module = module->next;
+
+	while (module && module->ops->init_context == NULL) 
+		module = module->next;
+
+	if (module == NULL) 
+		return LDB_SUCCESS;
+
+	return module->ops->init_context(module);
+}
+
+int ldb_next_start_trans(struct ldb_module *module)
+{
+	FIND_OP(module, start_transaction);
+	return module->ops->start_transaction(module);
+}
+
+int ldb_next_end_trans(struct ldb_module *module)
+{
+	FIND_OP(module, end_transaction);
+	return module->ops->end_transaction(module);
+}
+
+int ldb_next_del_trans(struct ldb_module *module)
+{
+	FIND_OP(module, del_transaction);
+	return module->ops->del_transaction(module);
+}