r16028: Re-add the objectclass module, in the new async scheme.

Add a test to show that we need this, and to prove it works (for add
at least).

Andrew Bartlett
(This used to be commit f72079029abb594677bf8c2b63e40c07e910004f)

1 files changed, 342 insertions, 98 deletions

diff --git a/source4/lib/ldb/modules/objectclass.c b/source4/lib/ldb/modules/objectclass.c
index a9c51341a8..4423f82aed 100644
--- a/source4/lib/ldb/modules/objectclass.c
+++ b/source4/lib/ldb/modules/objectclass.c
@@ -1,7 +1,8 @@
 /* 
    ldb database library
 
-   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
+   Copyright (C) Simo Sorce  2006
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2006
 
      ** NOTE! The following LGPL license applies to the ldb
      ** library. This does NOT imply that all of Samba is released
@@ -35,98 +36,256 @@
 #include "includes.h"
 #include "ldb/include/includes.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...
- */
+struct oc_async_context {
+
+	enum oc_step {OC_DO_REQ, OC_SEARCH_SELF, OC_DO_MOD} step;
+
+	struct ldb_module *module;
+	struct ldb_request *orig_req;
+
+	struct ldb_request *down_req;
+
+	struct ldb_request *search_req;
+	struct ldb_async_result *search_res;
+
+	struct ldb_request *mod_req;
+};
 
-static int objectclass_handle(struct ldb_module *module, struct ldb_request *req, const struct ldb_message *msg)
+static struct ldb_async_handle *oc_init_handle(struct ldb_request *req, struct ldb_module *module)
 {
-	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 oc_async_context *ac;
+	struct ldb_async_handle *h;
 
-	struct ldb_message_element *objectclass_element;
+	h = talloc_zero(req, struct ldb_async_handle);
+	if (h == NULL) {
+		ldb_set_errstring(module->ldb, talloc_asprintf(module, "Out of Memory"));
+		return NULL;
+	}
+
+	h->module = module;
+
+	ac = talloc_zero(h, struct oc_async_context);
+	if (ac == NULL) {
+		ldb_set_errstring(module->ldb, talloc_asprintf(module, "Out of Memory"));
+		talloc_free(h);
+		return NULL;
+	}
+
+	h->private_data = (void *)ac;
+
+	h->state = LDB_ASYNC_INIT;
+	h->status = LDB_SUCCESS;
+
+	ac->module = module;
+	ac->orig_req = req;
+
+	return h;
+}
+
+static int objectclass_add(struct ldb_module *module, struct ldb_request *req)
+{
+	struct ldb_async_handle *h;
+	struct oc_async_context *ac;
+	struct ldb_message_element *objectClassAttr;
 
-	ldb_debug(module->ldb, LDB_DEBUG_TRACE, "objectclass_handle\n");
+	ldb_debug(module->ldb, LDB_DEBUG_TRACE, "objectclass_add\n");
 
-	if (ldb_dn_is_special(msg->dn)) { /* do not manipulate our control entries */
+	if (ldb_dn_is_special(req->op.add.message->dn)) { /* do not manipulate our control entries */
 		return ldb_next_request(module, req);
 	}
+	
+	objectClassAttr = ldb_msg_find_element(req->op.add.message, "objectClass");
+
+	/* If no part of this touches the objectClass, then we don't
+	 * need to make any changes.  */
+	/* If the only operation is the deletion of the objectClass then go on */
+	if (!objectClassAttr) {
+		ldb_set_errstring(module->ldb, talloc_asprintf(ac, "Object class violation: no objectClass present"));
+		return LDB_ERR_OBJECT_CLASS_VIOLATION;
+	}
+
+	h = oc_init_handle(req, module);
+	if (!h) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ac = talloc_get_type(h->private_data, struct oc_async_context);
 
-	ret = ldb_next_request(module, req);
+	/* return or own handle to deal with this call */
+	req->async.handle = h;
 
-	if (ret) {
-		return ret;
+	/* prepare the first operation */
+	ac->down_req = talloc_zero(ac, struct ldb_request);
+	if (ac->down_req == NULL) {
+		ldb_set_errstring(module->ldb, talloc_asprintf(module->ldb, "Out of memory!"));
+		return LDB_ERR_OPERATIONS_ERROR;
 	}
 
-	if (ldb_msg_find_element(msg, "objectClass") == NULL ) {
-		/* No sign of the objectClass:  no change, nothing to see here */
-		return ret;
+	*(ac->down_req) = *req; /* copy the request */
+
+	ac->down_req->async.context = NULL;
+	ac->down_req->async.callback = NULL;
+
+	ac->step = OC_DO_REQ;
+
+	return ldb_next_request(module, ac->down_req);
+}
+
+static int objectclass_modify(struct ldb_module *module, struct ldb_request *req)
+{
+	struct ldb_async_handle *h;
+	struct oc_async_context *ac;
+	struct ldb_message_element *objectClassAttr;
+
+	ldb_debug(module->ldb, LDB_DEBUG_TRACE, "objectclass_modify\n");
+
+	if (ldb_dn_is_special(req->op.mod.message->dn)) { /* do not manipulate our control entries */
+		return ldb_next_request(module, req);
 	}
+	
+	objectClassAttr = ldb_msg_find_element(req->op.mod.message, "objectClass");
 
-	/* Thanks to transactions: Now do a search, find the full list
-	 * of objectClasses and do the sort */
+	/* If no part of this touches the objectClass, then we don't
+	 * need to make any changes.  */
+	/* If the only operation is the deletion of the objectClass then go on */
+	if (!objectClassAttr) {
+		return ldb_next_request(module, req);
+	}
 
-	mem_ctx = talloc_new(module);
-	if (!mem_ctx) {
+	h = oc_init_handle(req, module);
+	if (!h) {
 		return LDB_ERR_OPERATIONS_ERROR;
 	}
+	ac = talloc_get_type(h->private_data, struct oc_async_context);
 
-	search_request = talloc(mem_ctx, struct ldb_request);
-	if (!search_request) {
-		talloc_free(mem_ctx);
+	/* return or own handle to deal with this call */
+	req->async.handle = h;
+
+	/* prepare the first operation */
+	ac->down_req = talloc_zero(ac, struct ldb_request);
+	if (ac->down_req == NULL) {
+		ldb_set_errstring(module->ldb, talloc_asprintf(module->ldb, "Out of memory!"));
 		return LDB_ERR_OPERATIONS_ERROR;
 	}
 
-	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;
-	search_request->controls = NULL;
+	*(ac->down_req) = *req; /* copy the request */
 
-	ret = ldb_next_request(module, search_request);
-	if (ret) {
-		return ret;
+	ac->down_req->async.context = NULL;
+	ac->down_req->async.callback = NULL;
+
+	ac->step = OC_DO_REQ;
+
+	return ldb_next_request(module, ac->down_req);
+}
+
+static int get_self_callback(struct ldb_context *ldb, void *context, struct ldb_async_result *ares)
+{
+	struct oc_async_context *ac;
+
+	if (!context || !ares) {
+		ldb_set_errstring(ldb, talloc_asprintf(ldb, "NULL Context or Result in callback"));
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac = talloc_get_type(context, struct oc_async_context);
+
+	/* we are interested only in the single reply (base search) we receive here */
+	if (ares->type == LDB_REPLY_ENTRY) {
+		if (ac->search_res != NULL) {
+			ldb_set_errstring(ldb, talloc_asprintf(ldb, "Too many results"));
+			talloc_free(ares);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+
+		ac->search_res = talloc_steal(ac, ares);
+	} else {
+		talloc_free(ares);
+	}
+
+	return LDB_SUCCESS;
+}
+
+static int objectclass_search_self(struct ldb_async_handle *h) {
+
+	struct oc_async_context *ac;
+	static const char * const attrs[] = { "objectClass", NULL };
+
+	ac = talloc_get_type(h->private_data, struct oc_async_context);
+
+	/* prepare the search operation */
+	ac->search_req = talloc_zero(ac, struct ldb_request);
+	if (ac->search_req == NULL) {
+		ldb_debug(ac->module->ldb, LDB_DEBUG_ERROR, "Out of Memory!\n");
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac->search_req->operation = LDB_SEARCH;
+	ac->search_req->op.search.base = ac->orig_req->op.mod.message->dn;
+	ac->search_req->op.search.scope = LDB_SCOPE_BASE;
+	ac->search_req->op.search.tree = ldb_parse_tree(ac->module->ldb, NULL);
+	if (ac->search_req->op.search.tree == NULL) {
+		ldb_set_errstring(ac->module->ldb, talloc_asprintf(ac, "objectclass: Internal error producing null search"));
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	ac->search_req->op.search.attrs = attrs;
+	ac->search_req->controls = NULL;
+	ac->search_req->async.context = ac;
+	ac->search_req->async.callback = get_self_callback;
+	ac->search_req->async.timeout = ac->orig_req->async.timeout;
+
+	ac->step = OC_SEARCH_SELF;
+
+	return ldb_next_request(ac->module, ac->search_req);
+}
+
+static int objectclass_do_mod(struct ldb_async_handle *h) {
+
+	struct oc_async_context *ac;
+	struct ldb_message_element *objectclass_element;
+	struct ldb_message *msg;
+	TALLOC_CTX *mem_ctx;
+	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;
+	int ret;
+      
+	ac = talloc_get_type(h->private_data, struct oc_async_context);
+
+	mem_ctx = talloc_new(ac);
+	if (mem_ctx == NULL) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	ac->mod_req = talloc(ac, struct ldb_request);
+	if (ac->mod_req == NULL) {
+		talloc_free(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->ldb, 
-				  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... */
+	ac->mod_req->operation = LDB_MODIFY;
+	ac->mod_req->controls = NULL;
+	ac->mod_req->async.context = ac;
+	ac->mod_req->async.callback = NULL;
+	ac->mod_req->async.timeout = ac->orig_req->async.timeout;
+	
+	/* use a new message structure */
+	ac->mod_req->op.mod.message = msg = ldb_msg_new(ac->mod_req);
+	if (msg == NULL) {
+		ldb_set_errstring(ac->module->ldb, talloc_asprintf(ac, "objectclass: could not create new modify msg"));
 		talloc_free(mem_ctx);
-		return LDB_ERR_NO_SUCH_OBJECT;
+		return LDB_ERR_OPERATIONS_ERROR;
 	}
 
+	/* modify dn */
+	msg->dn = ac->orig_req->op.mod.message->dn;
+
 	/* This is now the objectClass list from the database */
-	objectclass_element = ldb_msg_find_element(res->msgs[0], "objectClass");
+	objectclass_element = ldb_msg_find_element(ac->search_res->message, 
+						   "objectClass");
 	if (!objectclass_element) {
 		/* Perhaps the above was a remove?  Move along now, nothing to see here */
 		talloc_free(mem_ctx);
@@ -166,6 +325,7 @@ static int objectclass_handle(struct ldb_module *module, struct ldb_request *req
 	for (i=0; i < objectclass_element->num_values; i++) {
 		current = talloc(mem_ctx, struct class_list);
 		if (!current) {
+			ldb_set_errstring(ac->module->ldb, talloc_asprintf(ac, "objectclass: out of memory allocating objectclass list"));
 			talloc_free(mem_ctx);
 			return LDB_ERR_OPERATIONS_ERROR;
 		}
@@ -189,7 +349,7 @@ static int objectclass_handle(struct ldb_module *module, struct ldb_request *req
 
 		/* 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);
+			const char **subclasses = ldb_subclass_list(ac->module->ldb, current->objectclass);
 
 			/* Walk the list of possible subclasses in unsorted */
 			for (poss_subclass = unsorted; poss_subclass; ) {
@@ -231,78 +391,162 @@ static int objectclass_handle(struct ldb_module *module, struct ldb_request *req
  	 */
 	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);
+	ret = ldb_msg_add_empty(msg, "objectClass", LDB_FLAG_MOD_REPLACE);
 	if (ret != LDB_SUCCESS) {
+		ldb_set_errstring(ac->module->ldb, talloc_asprintf(ac, "objectclass: could not clear objectclass in modify msg"));
 		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);
+		ret = ldb_msg_add_string(msg, "objectClass", current->objectclass);
 		if (ret != LDB_SUCCESS) {
+			ldb_set_errstring(ac->module->ldb, talloc_asprintf(ac, "objectclass: could not re-add sorted objectclass to modify msg"));
 			talloc_free(mem_ctx);
 			return ret;
 		}
 	}
 
-	ret = ldb_msg_sanity_check(modify_msg);
+	ret = ldb_msg_sanity_check(msg);
 	if (ret != LDB_SUCCESS) {
 		talloc_free(mem_ctx);
 		return ret;
 	}
 
-	modify_request = talloc(mem_ctx, struct ldb_request);
-	if (!modify_request) {
-		talloc_free(mem_ctx);
+
+	h->state = LDB_ASYNC_INIT;
+	h->status = LDB_SUCCESS;
+
+	ac->step = OC_DO_MOD;
+
+	talloc_free(mem_ctx);
+	/* perform the search */
+	return ldb_next_request(ac->module, ac->mod_req);
+}
+
+static int oc_async_wait(struct ldb_async_handle *handle) {
+	struct oc_async_context *ac;
+	int ret;
+    
+	if (!handle || !handle->private_data) {
 		return LDB_ERR_OPERATIONS_ERROR;
 	}
 
-	modify_request->operation = LDB_REQ_MODIFY;
-	modify_request->op.mod.message = modify_msg;
-	modify_request->controls = NULL;
+	if (handle->state == LDB_ASYNC_DONE) {
+		return handle->status;
+	}
 
-	/* And now push the write into the database */
-	ret = ldb_next_request(module, modify_request);
-	
-	talloc_free(mem_ctx);
+	handle->state = LDB_ASYNC_PENDING;
+	handle->status = LDB_SUCCESS;
+
+	ac = talloc_get_type(handle->private_data, struct oc_async_context);
+
+	switch (ac->step) {
+	case OC_DO_REQ:
+		ret = ldb_async_wait(ac->down_req->async.handle, LDB_WAIT_NONE);
+
+		if (ret != LDB_SUCCESS) {
+			handle->status = ret;
+			goto done;
+		}
+		if (ac->down_req->async.handle->status != LDB_SUCCESS) {
+			handle->status = ac->down_req->async.handle->status;
+			goto done;
+		}
+
+		if (ac->down_req->async.handle->state != LDB_ASYNC_DONE) {
+			return LDB_SUCCESS;
+		}
+
+		/* mods done, go on */
+		return objectclass_search_self(handle);
+
+	case OC_SEARCH_SELF:
+		ret = ldb_async_wait(ac->search_req->async.handle, LDB_WAIT_NONE);
+
+		if (ret != LDB_SUCCESS) {
+			handle->status = ret;
+			goto done;
+		}
+		if (ac->search_req->async.handle->status != LDB_SUCCESS) {
+			handle->status = ac->search_req->async.handle->status;
+			goto done;
+		}
+
+		if (ac->search_req->async.handle->state != LDB_ASYNC_DONE) {
+			return LDB_SUCCESS;
+		}
+
+		/* self search done, go on */
+		return objectclass_do_mod(handle);
+
+	case OC_DO_MOD:
+		ret = ldb_async_wait(ac->mod_req->async.handle, LDB_WAIT_NONE);
+
+		if (ret != LDB_SUCCESS) {
+			handle->status = ret;
+			goto done;
+		}
+		if (ac->mod_req->async.handle->status != LDB_SUCCESS) {
+			handle->status = ac->mod_req->async.handle->status;
+			goto done;
+		}
+
+		if (ac->mod_req->async.handle->state != LDB_ASYNC_DONE) {
+			return LDB_SUCCESS;
+		}
+
+		break;
+		
+	default:
+		ret = LDB_ERR_OPERATIONS_ERROR;
+		goto done;
+	}
+
+	ret = LDB_SUCCESS;
+
+done:
+	handle->state = LDB_ASYNC_DONE;
 	return ret;
 }
 
-static int objectclass_request(struct ldb_module *module, struct ldb_request *req)
-{
-	switch (req->operation) {
+static int oc_async_wait_all(struct ldb_async_handle *handle) {
 
-		/* only care about add and modify requests */
-	case LDB_REQ_ADD:
-		return objectclass_handle(module, req, req->op.add.message);
+	int ret;
 
-	case LDB_REQ_MODIFY:
-		return objectclass_handle(module, req, req->op.mod.message);
+	while (handle->state != LDB_ASYNC_DONE) {
+		ret = oc_async_wait(handle);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+	}
 
-	default:
-		return ldb_next_request(module, req);
+	return handle->status;
+}
 
+static int objectclass_async_wait(struct ldb_async_handle *handle, enum ldb_async_wait_type type)
+{
+	if (type == LDB_WAIT_ALL) {
+		return oc_async_wait_all(handle);
+	} else {
+		return oc_async_wait(handle);
 	}
 }
 
 static const struct ldb_module_ops objectclass_ops = {
 	.name		   = "objectclass",
-	.request      	   = objectclass_request,
+	.add           = objectclass_add,
+	.modify        = objectclass_modify,
+	.async_wait    = objectclass_async_wait
 };
 
 int ldb_objectclass_init(void)
 {
 	return ldb_register_module(&objectclass_ops);
 }
+