lib: mgmtd: add changed and created to edit-reply msg

- This is used for various return values in RESTCONF

Signed-off-by: Christian Hopps <chopps@labn.net>

lib/mgmt_msg_native.h

@@ -383,11 +383,18 @@ _Static_assert(sizeof(struct mgmt_msg_edit) ==
 /**
  * struct mgmt_msg_edit_reply - frontend edit reply.
  *
- * @data: the xpath of the data node that was created.
+ * @changed: If true then changes in datastore resulted.
+ * @created: If true then object was newly created (non-existing before)
+ * @data: @vsplit values, second value may be zero len.
+ * @data: [0] the xpath of the data node that was created.
+ * @data: [1] Possible structured data to pass back to client (e.g., non-"error"
+ *        yang modeled error data).
  */
 struct mgmt_msg_edit_reply {
 	struct mgmt_msg_header;
-	uint8_t resv2[8];
+	uint8_t changed;
+	uint8_t created;
+	uint8_t resv2[6];
 
 	alignas(8) char data[];
 };

lib/northbound.c

@@ -816,8 +816,9 @@ int nb_candidate_edit(struct nb_config *candidate, const struct nb_node *nb_node
 static int nb_candidate_edit_tree_add(struct nb_config *candidate,
 				      enum nb_operation operation,
 				      LYD_FORMAT format, const char *xpath,
-				      const char *data, char *xpath_created,
-				      char *errmsg, size_t errmsg_len)
+				      const char *data, bool *created,
+				      char *xpath_created, char *errmsg,
+				      size_t errmsg_len)
 {
 	struct lyd_node *tree = NULL;
 	struct lyd_node *parent = NULL;
@@ -897,10 +898,18 @@ static int nb_candidate_edit_tree_add(struct nb_config *candidate,
 	}
 
 	/* check if the node already exists in candidate */
-	if (operation == NB_OP_CREATE_EXCL || operation == NB_OP_REPLACE) {
+	if (operation == NB_OP_CREATE || operation == NB_OP_MODIFY)
+		existing = yang_dnode_get(candidate->dnode, xpath_created);
+	else if (operation == NB_OP_CREATE_EXCL || operation == NB_OP_REPLACE) {
 		existing = yang_dnode_get(candidate->dnode, xpath_created);
 
 		/* if the existing node is implicit default, ignore */
+		/* Q: Is this correct for CREATE_EXCL which is supposed to error
+		 * if the resouurce already exists? This is used by RESTCONF
+		 * when processing the POST command, for example. RFC8040
+		 * doesn't say POST fails if resource exists "unless it was a
+		 * default".
+		 */
 		if (existing && (existing->flags & LYD_DEFAULT))
 			existing = NULL;
 
@@ -930,7 +939,7 @@ static int nb_candidate_edit_tree_add(struct nb_config *candidate,
 				 LYD_MERGE_DESTRUCT | LYD_MERGE_WITH_FLAGS);
 	if (err) {
 		/* if replace failed, restore the original node */
-		if (existing) {
+		if (existing && operation == NB_OP_REPLACE) {
 			if (root) {
 				/* Restoring the whole config. */
 				candidate->dnode = existing;
@@ -954,6 +963,8 @@ static int nb_candidate_edit_tree_add(struct nb_config *candidate,
 		ret = NB_ERR;
 		goto done;
 	} else {
+		if (!existing)
+			*created = true;
 		/*
 		 * Free existing node after replace.
 		 * We're using `lyd_free_siblings` here to free the whole
@@ -961,7 +972,7 @@ static int nb_candidate_edit_tree_add(struct nb_config *candidate,
 		 * siblings if it wasn't root, because the existing node
 		 * was unlinked from the tree.
 		 */
-		if (existing)
+		if (existing && operation == NB_OP_REPLACE)
 			lyd_free_siblings(existing);
 
 		tree = NULL; /* LYD_MERGE_DESTRUCT deleted the tree */
@@ -1011,7 +1022,7 @@ static int nb_candidate_edit_tree_del(struct nb_config *candidate,
 
 int nb_candidate_edit_tree(struct nb_config *candidate,
 			   enum nb_operation operation, LYD_FORMAT format,
-			   const char *xpath, const char *data,
+			   const char *xpath, const char *data, bool *created,
 			   char *xpath_created, char *errmsg, size_t errmsg_len)
 {
 	int ret = NB_ERR;
@@ -1022,8 +1033,9 @@ int nb_candidate_edit_tree(struct nb_config *candidate,
 	case NB_OP_MODIFY:
 	case NB_OP_REPLACE:
 		ret = nb_candidate_edit_tree_add(candidate, operation, format,
-						 xpath, data, xpath_created,
-						 errmsg, errmsg_len);
+						 xpath, data, created,
+						 xpath_created, errmsg,
+						 errmsg_len);
 		break;
 	case NB_OP_DESTROY:
 	case NB_OP_DELETE:

lib/northbound.h

@@ -1016,6 +1016,9 @@ extern int nb_candidate_edit(struct nb_config *candidate,
  * data
  *    New data tree for the node.
  *
+ * created
+ *    OUT param set accordingly if a node was created or just updated
+ *
  * xpath_created
  *    XPath of the created node if operation is "create".
  *
@@ -1030,9 +1033,9 @@ extern int nb_candidate_edit(struct nb_config *candidate,
  *    - NB_ERR for other errors.
  */
 extern int nb_candidate_edit_tree(struct nb_config *candidate,
-				  enum nb_operation operation,
-				  LYD_FORMAT format, const char *xpath,
-				  const char *data, char *xpath_created,
+				  enum nb_operation operation, LYD_FORMAT format,
+				  const char *xpath, const char *data,
+				  bool *created, char *xpath_created,
 				  char *errmsg, size_t errmsg_len);
 
 /*

mgmtd/mgmt_fe_adapter.c

@@ -1164,7 +1164,9 @@ done:
 }
 
 static int fe_adapter_send_edit_reply(struct mgmt_fe_session_ctx *session,
-				      uint64_t req_id, const char *xpath)
+				      uint64_t req_id, bool changed,
+				      bool created, const char *xpath,
+				      const char *data)
 {
 	struct mgmt_msg_edit_reply *msg;
 	int ret;
@@ -1173,14 +1175,19 @@ static int fe_adapter_send_edit_reply(struct mgmt_fe_session_ctx *session,
 					MTYPE_MSG_NATIVE_EDIT_REPLY);
 	msg->refer_id = session->session_id;
 	msg->req_id = req_id;
+	msg->changed = changed;
+	msg->created = created;
 	msg->code = MGMT_MSG_CODE_EDIT_REPLY;
 
 	mgmt_msg_native_xpath_encode(msg, xpath);
 
+	if (data)
+		mgmt_msg_native_append(msg, data, strlen(data) + 1);
+
 	__dbg("Sending edit-reply from adapter %s to session-id %" PRIu64
-	      " req-id %" PRIu64 " len %u",
-	      session->adapter->name, session->session_id, req_id,
-	      mgmt_msg_native_get_msg_len(msg));
+	      " req-id %" PRIu64 " changed %u created %u len %u",
+	      session->adapter->name, session->session_id, req_id, changed,
+	      created, mgmt_msg_native_get_msg_len(msg));
 
 	ret = fe_adapter_send_native_msg(session->adapter, msg,
 					 mgmt_msg_native_get_msg_len(msg),
@@ -1977,8 +1984,8 @@ int mgmt_fe_adapter_send_rpc_reply(uint64_t session_id, uint64_t txn_id,
 
 int mgmt_fe_adapter_send_edit_reply(uint64_t session_id, uint64_t txn_id,
 				    uint64_t req_id, bool unlock, bool commit,
-				    const char *xpath, int16_t error,
-				    const char *errstr)
+				    bool created, const char *xpath,
+				    int16_t error, const char *errstr)
 {
 	struct mgmt_fe_session_ctx *session;
 	Mgmtd__DatastoreId ds_id, rds_id;
@@ -2009,11 +2016,12 @@ int mgmt_fe_adapter_send_edit_reply(uint64_t session_id, uint64_t txn_id,
 		}
 	}
 
-	if (error)
+	if (error != 0 && error != -EALREADY)
 		ret = fe_adapter_send_error(session, req_id, false, error, "%s",
 					    errstr);
 	else
-		ret = fe_adapter_send_edit_reply(session, req_id, xpath);
+		ret = fe_adapter_send_edit_reply(session, req_id, created,
+						 !error, xpath, errstr);
 
 	if (session->cfg_txn_id != MGMTD_TXN_ID_NONE && !commit)
 		mgmt_destroy_txn(&session->cfg_txn_id);

mgmtd/mgmt_fe_adapter.h

@@ -193,14 +193,16 @@ extern int mgmt_fe_adapter_send_rpc_reply(uint64_t session_id, uint64_t txn_id,
  *     req_id: the req id for the edit message
  *     unlock: implicit-lock flag was set in the request
  *     commit: implicit-commit flag was set in the request
- *     xpath: the xpath of the data node that was created
+ *     created: true if the node was just created
+ *     xpath: the xpath of the data node that was created/updated
  *     error: >0 LY_ERR, < 0 -errno
  *     errstr: the error string, if error is non-zero
  */
 extern int mgmt_fe_adapter_send_edit_reply(uint64_t session_id, uint64_t txn_id,
 					   uint64_t req_id, bool unlock,
-					   bool commit, const char *xpath,
-					   int16_t error, const char *errstr);
+					   bool commit, bool created,
+					   const char *xpath, int16_t error,
+					   const char *errstr);
 
 /**
  * Send an error back to the FE client using native messaging.

mgmtd/mgmt_txn.c

@@ -94,6 +94,7 @@ DECLARE_LIST(mgmt_txn_batches, struct mgmt_txn_be_cfg_batch, list_linkage);
 
 struct mgmt_edit_req {
 	char xpath_created[XPATH_MAXLEN];
+	bool created;
 	bool unlock;
 };
 
@@ -741,6 +742,8 @@ static int mgmt_txn_send_commit_cfg_reply(struct mgmt_txn_ctx *txn,
 					    txn->commit_cfg_req->req.commit_cfg
 						    .edit->unlock,
 					    true,
+					    txn->commit_cfg_req->req.commit_cfg
+						    .edit->created,
 					    txn->commit_cfg_req->req.commit_cfg
 						    .edit->xpath_created,
 					    success ? 0 : -1,
@@ -2566,8 +2569,8 @@ int mgmt_txn_send_edit(uint64_t txn_id, uint64_t req_id,
 	assert(nb_config);
 
 	ret = nb_candidate_edit_tree(nb_config, operation, request_type, xpath,
-				     data, edit->xpath_created, errstr,
-				     sizeof(errstr));
+				     data, &edit->created, edit->xpath_created,
+				     errstr, sizeof(errstr));
 	if (ret)
 		goto reply;
 
@@ -2581,7 +2584,8 @@ int mgmt_txn_send_edit(uint64_t txn_id, uint64_t req_id,
 	}
 reply:
 	mgmt_fe_adapter_send_edit_reply(txn->session_id, txn->txn_id, req_id,
-					unlock, commit, edit->xpath_created,
+					unlock, commit, edit->created,
+					edit->xpath_created,
 					errno_from_nb_error(ret), errstr);
 
 	XFREE(MTYPE_MGMTD_TXN_REQ, edit);