s4:samldb LDB module - simplify/unify the message handling on add and modify operations

- Perform only shallow copies (should be enough)
- Perform only one copy per operation (also on modifications)
- Build a new request on modify operations if needed ("modified" flag) - this
  makes it look cleaner
- Fix an important bug: the "el" pointers could have changed after
  modifications. Therefore we have to refresh them on the FLAG_DELETE checks

Autobuild-User: Matthias Dieter Wallnöfer <mdw@samba.org>
Autobuild-Date: Tue Oct  5 09:24:57 UTC 2010 on sn-devel-104

1 files changed, 54 insertions, 28 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/samldb.c b/source4/dsdb/samdb/ldb_modules/samldb.c
index 0e4d852d15..f3a9e08e72 100644
--- a/source4/dsdb/samdb/ldb_modules/samldb.c
+++ b/source4/dsdb/samdb/ldb_modules/samldb.c
@@ -1093,11 +1093,11 @@ static int samldb_add(struct ldb_module *module, struct ldb_request *req)
 	}
 
 	/* build the new msg */
-	ac->msg = ldb_msg_copy(ac, ac->req->op.add.message);
-	if (!ac->msg) {
+	ac->msg = ldb_msg_copy_shallow(ac, req->op.add.message);
+	if (ac->msg == NULL) {
 		talloc_free(ac);
 		ldb_debug(ldb, LDB_DEBUG_FATAL,
-			  "samldb_add: ldb_msg_copy failed!\n");
+			  "samldb_add: ldb_msg_copy_shallow failed!\n");
 		return ldb_operr(ldb);
 	}
 
@@ -1151,8 +1151,8 @@ static int samldb_modify(struct ldb_module *module, struct ldb_request *req)
 {
 	struct ldb_context *ldb;
 	struct samldb_ctx *ac;
-	struct ldb_message *msg;
 	struct ldb_message_element *el, *el2;
+	bool modified = false;
 	int ret;
 	uint32_t account_type;
 
@@ -1182,101 +1182,127 @@ static int samldb_modify(struct ldb_module *module, struct ldb_request *req)
 		return ldb_operr(ldb);
 	}
 
-	/* TODO: do not modify original request, create a new one */
+	/* build the new msg */
+	ac->msg = ldb_msg_copy_shallow(ac, req->op.mod.message);
+	if (ac->msg == NULL) {
+		talloc_free(ac);
+		ldb_debug(ldb, LDB_DEBUG_FATAL,
+			  "samldb_modify: ldb_msg_copy_shallow failed!\n");
+		return ldb_operr(ldb);
+	}
 
-	el = ldb_msg_find_element(req->op.mod.message, "groupType");
+	el = ldb_msg_find_element(ac->msg, "groupType");
 	if (el && (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_REPLACE) && el->num_values == 1) {
 		uint32_t group_type;
 
-		req->op.mod.message = msg = ldb_msg_copy_shallow(req,
-			req->op.mod.message);
+		modified = true;
 
 		group_type = strtoul((const char *)el->values[0].data, NULL, 0);
 		account_type =  ds_gtype2atype(group_type);
-		ret = samdb_msg_add_uint(ldb, msg, msg,
+		ret = samdb_msg_add_uint(ldb, ac->msg, ac->msg,
 					 "sAMAccountType",
 					 account_type);
 		if (ret != LDB_SUCCESS) {
 			return ret;
 		}
-		el2 = ldb_msg_find_element(msg, "sAMAccountType");
+		el2 = ldb_msg_find_element(ac->msg, "sAMAccountType");
 		el2->flags = LDB_FLAG_MOD_REPLACE;
 	}
+	el = ldb_msg_find_element(ac->msg, "groupType");
 	if (el && (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_DELETE)) {
 		return LDB_ERR_UNWILLING_TO_PERFORM;
 	}
 
-	el = ldb_msg_find_element(req->op.mod.message, "primaryGroupID");
+	el = ldb_msg_find_element(ac->msg, "primaryGroupID");
 	if (el && (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_REPLACE) && el->num_values == 1) {
-		req->op.mod.message = ac->msg = ldb_msg_copy_shallow(req,
-			req->op.mod.message);
+		modified = true;
 
 		ret = samldb_prim_group_change(ac);
 		if (ret != LDB_SUCCESS) {
 			return ret;
 		}
 	}
+	el = ldb_msg_find_element(ac->msg, "primaryGroupID");
 	if (el && (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_DELETE)) {
 		return LDB_ERR_UNWILLING_TO_PERFORM;
 	}
 
-	el = ldb_msg_find_element(req->op.mod.message, "userAccountControl");
+	el = ldb_msg_find_element(ac->msg, "userAccountControl");
 	if (el && (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_REPLACE) && el->num_values == 1) {
 		uint32_t user_account_control;
 
-		req->op.mod.message = msg = ldb_msg_copy_shallow(req,
-			req->op.mod.message);
+		modified = true;
 
 		user_account_control = strtoul((const char *)el->values[0].data,
 			NULL, 0);
 		account_type = ds_uf2atype(user_account_control);
-		ret = samdb_msg_add_uint(ldb, msg, msg,
+		ret = samdb_msg_add_uint(ldb, ac->msg, ac->msg,
 					 "sAMAccountType",
 					 account_type);
 		if (ret != LDB_SUCCESS) {
 			return ret;
 		}
-		el2 = ldb_msg_find_element(msg, "sAMAccountType");
+		el2 = ldb_msg_find_element(ac->msg, "sAMAccountType");
 		el2->flags = LDB_FLAG_MOD_REPLACE;
 
 		if (user_account_control & (UF_SERVER_TRUST_ACCOUNT | UF_PARTIAL_SECRETS_ACCOUNT)) {
-			ret = samdb_msg_add_string(ldb, msg, msg,
-						   "isCriticalSystemObject", "TRUE");
+			ret = samdb_msg_add_string(ldb, ac->msg, ac->msg,
+						   "isCriticalSystemObject",
+						   "TRUE");
 			if (ret != LDB_SUCCESS) {
 				return ret;
 			}
-			el2 = ldb_msg_find_element(msg, "isCriticalSystemObject");
+			el2 = ldb_msg_find_element(ac->msg,
+						   "isCriticalSystemObject");
 			el2->flags = LDB_FLAG_MOD_REPLACE;
 		}
 
-		if (!ldb_msg_find_element(msg, "primaryGroupID")) {
+		if (!ldb_msg_find_element(ac->msg, "primaryGroupID")) {
 			uint32_t rid = ds_uf2prim_group_rid(user_account_control);
 
-			ret = samdb_msg_add_uint(ldb, msg, msg,
+			ret = samdb_msg_add_uint(ldb, ac->msg, ac->msg,
 						 "primaryGroupID", rid);
 			if (ret != LDB_SUCCESS) {
 				return ret;
 			}
-			el2 = ldb_msg_find_element(msg,
+			el2 = ldb_msg_find_element(ac->msg,
 						   "primaryGroupID");
 			el2->flags = LDB_FLAG_MOD_REPLACE;
 		}
 	}
+	el = ldb_msg_find_element(ac->msg, "userAccountControl");
 	if (el && (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_DELETE)) {
 		return LDB_ERR_UNWILLING_TO_PERFORM;
 	}
 
-	el = ldb_msg_find_element(req->op.mod.message, "member");
+	el = ldb_msg_find_element(ac->msg, "member");
 	if (el && el->flags & (LDB_FLAG_MOD_ADD|LDB_FLAG_MOD_REPLACE) && el->num_values == 1) {
-		req->op.mod.message = ac->msg = ldb_msg_copy_shallow(req,
-			req->op.mod.message);
-
 		ret = samldb_member_check(ac);
 		if (ret != LDB_SUCCESS) {
 			return ret;
 		}
 	}
 
+	if (modified) {
+		struct ldb_request *child_req;
+
+		/* Now perform the real modifications as a child request */
+		ret = ldb_build_mod_req(&child_req, ldb, ac,
+					ac->msg,
+					req->controls,
+					req, dsdb_next_callback,
+					req);
+		LDB_REQ_SET_LOCATION(child_req);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+
+		return ldb_next_request(module, child_req);
+	}
+
+	talloc_free(ac);
+
+	/* no change which interests us, go on */
 	return ldb_next_request(module, req);
 }