--- /dev/null
+/*
+ ldb database library
+
+ Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
+
+ ** 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: objectClass sorting module
+ *
+ * Description: sort the objectClass attribute into the class hierarchy
+ *
+ * Author: Andrew Bartlett
+ */
+
+#include "includes.h"
+#include "ldb/include/ldb.h"
+#include "ldb/include/ldb_private.h"
+#include "ldb/include/ldb_errors.h"
+#include "ldb/include/dlinklist.h"
+
+/* It turns out the MMC assumes that the last objectClass in the list
+ * is the most specific subclass. As such, we must sort the list,
+ * according to the schema.
+ *
+ * For performance, we do this on the add/modify, not on the search
+ *
+ * We perform the original add/modify, then search for that is now in
+ * the objectClass list. We can then then replace that with the new
+ * sorted list. The backend is expected to preserve ordering for
+ * subsequent searches.
+ *
+ * We are in a transaction, so this is all perfectly safe...
+ */
+
+static int objectclass_handle(struct ldb_module *module, struct ldb_request *req, const struct ldb_message *msg)
+{
+ TALLOC_CTX *mem_ctx;
+ int ret;
+ struct ldb_request search_request;
+ struct ldb_request modify_request;
+ struct ldb_message *modify_msg;
+ struct ldb_result *res;
+ const char *attrs[] = { "objectClass", NULL };
+ struct class_list {
+ struct class_list *prev, *next;
+ const char *objectclass;
+ };
+ struct class_list *sorted = NULL, *parent_class = NULL,
+ *subclass = NULL, *unsorted = NULL, *current, *poss_subclass;
+ int i;
+ int layer;
+
+ struct ldb_message_element *objectclass_element;
+
+ ldb_debug(module->ldb, LDB_DEBUG_TRACE, "objectclass_handle\n");
+
+ if (ldb_dn_is_special(msg->dn)) { /* do not manipulate our control entries */
+ return ldb_next_request(module, req);
+ }
+
+ ret = ldb_next_request(module, req);
+
+ if (ret) {
+ return ret;
+ }
+
+ if (ldb_msg_find_element(msg, "objectClass") == NULL ) {
+ /* No sign of the objectClass: no change, nothing to see here */
+ return ret;
+ }
+
+ /* Thanks to transactions: Now do a search, find the full list
+ * of objectClasses and do the sort */
+
+ search_request.operation = LDB_REQ_SEARCH;
+ search_request.op.search.base = msg->dn;
+ search_request.op.search.scope = LDB_SCOPE_BASE;
+ search_request.op.search.tree = ldb_parse_tree(module->ldb, NULL);
+ search_request.op.search.attrs = attrs;
+
+ ret = ldb_next_request(module, &search_request);
+ if (ret) {
+ return ret;
+ }
+
+ mem_ctx = talloc_new(module);
+ if (!mem_ctx) {
+ return LDB_ERR_OPERATIONS_ERROR;
+ }
+
+ res = search_request.op.search.res;
+ talloc_steal(mem_ctx, res);
+ if (res->count != 1) {
+ ldb_set_errstring(module,
+ talloc_asprintf(mem_ctx, "objectClass_handle: "
+ "search for %s found %d != 1 objects, for entry we just added/modified",
+ ldb_dn_linearize(mem_ctx, msg->dn),
+ res->count));
+ /* What happened? The above add/modify worked... */
+ talloc_free(mem_ctx);
+ return LDB_ERR_NO_SUCH_OBJECT;
+ }
+
+ /* This is now the objectClass list from the database */
+ objectclass_element = ldb_msg_find_element(res->msgs[0], "objectClass");
+ if (!objectclass_element) {
+ /* Perhaps the above was a remove? Move along now, nothing to see here */
+ talloc_free(mem_ctx);
+ return LDB_SUCCESS;
+ }
+
+ /* DESIGN:
+ *
+ * We work on 4 different 'bins' (implemented here as linked lists):
+ *
+ * * sorted: the eventual list, in the order we wish to push
+ * into the database. This is the only ordered list.
+ *
+ * * parent_class: The current parent class 'bin' we are
+ * trying to find subclasses for
+ *
+ * * subclass: The subclasses we have found so far
+ *
+ * * unsorted: The remaining objectClasses
+ *
+ * The process is a matter of filtering objectClasses up from
+ * unsorted into sorted. Order is irrelevent in the later 3 'bins'.
+ *
+ * We start with 'top' (found and promoted to parent_class
+ * initially). Then we find (in unsorted) all the direct
+ * subclasses of 'top'. parent_classes is concatenated onto
+ * the end of 'sorted', and subclass becomes the list in
+ * parent_class.
+ *
+ * We then repeat, until we find no more subclasses. Any left
+ * over classes are added to the end.
+ *
+ */
+
+ /* Firstly, dump all the objectClass elements into the
+ * unsorted bin, except for 'top', which is special */
+ for (i=0; i < objectclass_element->num_values; i++) {
+ current = talloc(mem_ctx, struct class_list);
+ if (!current) {
+ talloc_free(mem_ctx);
+ return LDB_ERR_OPERATIONS_ERROR;
+ }
+ current->objectclass = (const char *)objectclass_element->values[i].data;
+
+ /* this is the root of the tree. We will start
+ * looking for subclasses from here */
+ if (ldb_attr_cmp("top", current->objectclass) == 0) {
+ DLIST_ADD(parent_class, current);
+ } else {
+ DLIST_ADD(unsorted, current);
+ }
+ }
+
+ /* DEBUGGING aid: how many layers are we down now? */
+ layer = 0;
+ do {
+ layer++;
+ /* Find all the subclasses of classes in the
+ * parent_classes. Push them onto the subclass list */
+
+ /* Ensure we don't bother if there are no unsorted entries left */
+ for (current = parent_class; unsorted && current; current = current->next) {
+ const char **subclasses = ldb_subclass_list(module->ldb, current->objectclass);
+
+ /* Walk the list of possible subclasses in unsorted */
+ for (poss_subclass = unsorted; poss_subclass; ) {
+ struct class_list *next;
+
+ /* Save the next pointer, as the DLIST_ macros will change poss_subclass->next */
+ next = poss_subclass->next;
+
+ for (i = 0; subclasses && subclasses[i]; i++) {
+ if (ldb_attr_cmp(poss_subclass->objectclass, subclasses[i]) == 0) {
+ DLIST_REMOVE(unsorted, poss_subclass);
+ DLIST_ADD(subclass, poss_subclass);
+
+ break;
+ }
+ }
+ poss_subclass = next;
+ }
+ }
+
+ /* Now push the parent_classes as sorted, we are done with
+ these. Add to the END of the list by concatenation */
+ DLIST_CONCATENATE(sorted, parent_class, struct class_list *);
+
+ /* and now find subclasses of these */
+ parent_class = subclass;
+ subclass = NULL;
+
+ /* If we didn't find any subclasses we will fall out
+ * the bottom here */
+ } while (parent_class);
+
+ /* This shouldn't happen, and would break MMC, but we can't
+ * afford to loose objectClasses. Perhaps there was no 'top',
+ * or some other schema error?
+ *
+ * Detecting schema errors is the job of the schema module, so
+ * at this layer we just try not to loose data
+ */
+ DLIST_CONCATENATE(sorted, unsorted, struct class_list *);
+
+ modify_msg = ldb_msg_new(mem_ctx);
+ if (!modify_msg) {
+ talloc_free(mem_ctx);
+ return LDB_ERR_OPERATIONS_ERROR;
+ }
+ modify_msg->dn = talloc_reference(modify_msg, msg->dn);
+
+ /* We must completely replace the existing objectClass entry.
+ * We could do a constrained add/del, but we are meant to be
+ * in a transaction... */
+
+ ret = ldb_msg_add_empty(modify_msg, "objectClass", LDB_FLAG_MOD_REPLACE);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(mem_ctx);
+ return ret;
+ }
+
+ /* Move from the linked list back into an ldb msg */
+ for (current = sorted; current; current = current->next) {
+ ret = ldb_msg_add_string(modify_msg, "objectClass", current->objectclass);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(mem_ctx);
+ return ret;
+ }
+ }
+
+ ret = ldb_msg_sanity_check(modify_msg);
+ if (ret != LDB_SUCCESS) {
+ talloc_free(mem_ctx);
+ return ret;
+ }
+
+ modify_request.operation = LDB_REQ_MODIFY;
+ modify_request.op.mod.message = modify_msg;
+
+ /* And now push the write into the database */
+ ret = ldb_next_request(module, &modify_request);
+
+ talloc_free(mem_ctx);
+ return ret;
+}
+
+static int objectclass_request(struct ldb_module *module, struct ldb_request *req)
+{
+ switch (req->operation) {
+
+ /* only care about add and modify requests */
+ case LDB_REQ_ADD:
+ return objectclass_handle(module, req, req->op.add.message);
+
+ case LDB_REQ_MODIFY:
+ return objectclass_handle(module, req, req->op.mod.message);
+
+ default:
+ return ldb_next_request(module, req);
+
+ }
+}
+
+static const struct ldb_module_ops objectclass_ops = {
+ .name = "objectclass",
+ .request = objectclass_request,
+};
+
+#ifdef HAVE_DLOPEN_DISABLED
+struct ldb_module *init_module(struct ldb_context *ldb, const char *options[])
+#else
+struct ldb_module *objectclass_module_init(struct ldb_context *ldb, const char *options[])
+#endif
+{
+ struct ldb_module *ctx;
+
+ ctx = talloc(ldb, struct ldb_module);
+ if (!ctx)
+ return NULL;
+
+ ctx->private_data = NULL;
+
+ ctx->ldb = ldb;
+ ctx->prev = ctx->next = NULL;
+ ctx->ops = &objectclass_ops;
+
+ return ctx;
+}
git.samba.org / kai / samba-autobuild / .git / commitdiff