s4:samldb/objectclass_attrs LDB modules - move "description" logic from "objectclass_attrs" into "samldb"

This according to an answer from dochelp is SAM specific behaviour.

1 files changed, 81 insertions, 0 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c
index 0cd8bc9bcc..4b8a303753 100644
--- a/source4/dsdb/samdb/ldb_modules/samldb.c
+++ b/source4/dsdb/samdb/ldb_modules/samldb.c
@@ -1496,6 +1496,79 @@ static int samldb_member_check(struct samldb_ctx *ac)
 		}
 	}
 
+	talloc_free(res);
+
+	return LDB_SUCCESS;
+}
+
+/* SAM objects have special rules regarding the "description" attribute on
+ * modify operations. */
+static int samldb_description_check(struct samldb_ctx *ac)
+{
+	struct ldb_context *ldb = ldb_module_get_ctx(ac->module);
+	const char * const attrs[] = { "objectClass", "description", NULL };
+	struct ldb_message_element *el;
+	struct ldb_result *res;
+	unsigned int i;
+	int ret;
+
+	/* Fetch informations from the existing object */
+
+	ret = ldb_search(ldb, ac, &res, ac->msg->dn, LDB_SCOPE_BASE, attrs,
+			 NULL);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	if (res->count != 1) {
+		return ldb_operr(ldb);
+	}
+
+	/* if it's not a SAM object then please skip the constraints */
+	if ((samdb_find_attribute(ldb, res->msgs[0], "objectClass",
+				  "group") == NULL) &&
+	    (samdb_find_attribute(ldb, res->msgs[0], "objectClass",
+				  "samDomain") == NULL) &&
+	    (samdb_find_attribute(ldb, res->msgs[0], "objectClass",
+				  "samServer") == NULL) &&
+	    (samdb_find_attribute(ldb, res->msgs[0], "objectClass",
+				  "user") == NULL)) {
+		talloc_free(res);
+		return LDB_SUCCESS;
+	}
+
+	/* We've to walk over all modification entries and consider the
+	 * "description" ones. */
+	for (i = 0; i < ac->msg->num_elements; i++) {
+		if (ldb_attr_cmp(ac->msg->elements[i].name,
+				 "description") != 0) {
+			continue;
+		}
+
+		el = &ac->msg->elements[i];
+
+		/* Multi-valued add or replace operations are always denied */
+		if ((LDB_FLAG_MOD_TYPE(el->flags) != LDB_FLAG_MOD_DELETE) &&
+		    (el->num_values > 1)) {
+			ldb_asprintf_errstring(ldb,
+					       "samldb: Description on SAM entry '%s' is changed using a multi-valued add or replace operation!",
+					       ldb_dn_get_linearized(ac->msg->dn));
+			return LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
+		}
+
+		/* Add operations are only allowed if no value exists */
+		if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_ADD) {
+			if (ldb_msg_find_element(res->msgs[0], "description")
+								!= NULL) {
+				ldb_asprintf_errstring(ldb,
+						       "samldb: Description on SAM entry '%s' is changed using an add operation while a value already exists!",
+						       ldb_dn_get_linearized(ac->msg->dn));
+				return LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
+			}
+		}
+	}
+
+	talloc_free(res);
+
 	return LDB_SUCCESS;
 }
 
@@ -1894,6 +1967,14 @@ static int samldb_modify(struct ldb_module *module, struct ldb_request *req)
 		}
 	}
 
+	el = ldb_msg_find_element(ac->msg, "description");
+	if (el != NULL) {
+		ret = samldb_description_check(ac);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	}
+
 	el = ldb_msg_find_element(ac->msg, "dNSHostName");
 	el2 = ldb_msg_find_element(ac->msg, "sAMAccountName");
 	if ((el != NULL) || (el2 != NULL)) {