Merge pull request #15594 from idryzhov/mgmt-rpc

mgmtd: implement YANG RPC/action support

lib/mgmt.proto

@@ -79,6 +79,7 @@ message BeSubscribeReq {
   repeated string config_xpaths = 2;
   repeated string oper_xpaths = 3;
   repeated string notif_xpaths = 4;
+  repeated string rpc_xpaths = 5;
 }
 
 message BeSubscribeReply {

lib/mgmt_be_client.c

@@ -915,6 +915,143 @@ static void be_client_handle_get_tree(struct mgmt_be_client *client,
 		   be_client_send_tree_data_batch, args);
 }
 
+static void be_client_send_rpc_reply(struct mgmt_be_client *client,
+				     uint64_t txn_id, uint64_t req_id,
+				     uint8_t result_type,
+				     struct lyd_node *output)
+{
+	struct mgmt_msg_rpc_reply *rpc_reply_msg;
+	uint8_t **darrp;
+	LY_ERR err;
+	int ret = NB_OK;
+
+	rpc_reply_msg = mgmt_msg_native_alloc_msg(struct mgmt_msg_rpc_reply, 0,
+						  MTYPE_MSG_NATIVE_RPC_REPLY);
+	rpc_reply_msg->refer_id = txn_id;
+	rpc_reply_msg->req_id = req_id;
+	rpc_reply_msg->code = MGMT_MSG_CODE_RPC_REPLY;
+	rpc_reply_msg->result_type = result_type;
+
+	if (output) {
+		darrp = mgmt_msg_native_get_darrp(rpc_reply_msg);
+		err = yang_print_tree_append(darrp, output, result_type,
+					     LYD_PRINT_SHRINK);
+		lyd_free_all(output);
+		if (err) {
+			ret = NB_ERR;
+			goto done;
+		}
+	}
+
+	(void)be_client_send_native_msg(client, rpc_reply_msg,
+					mgmt_msg_native_get_msg_len(
+						rpc_reply_msg),
+					false);
+done:
+	mgmt_msg_native_free_msg(rpc_reply_msg);
+	if (ret != NB_OK)
+		be_client_send_error(client, txn_id, req_id, false, -EINVAL,
+				     "Can't format RPC reply");
+}
+
+/*
+ * Process the RPC request.
+ */
+static void be_client_handle_rpc(struct mgmt_be_client *client, uint64_t txn_id,
+				 void *msgbuf, size_t msg_len)
+{
+	struct mgmt_msg_rpc *rpc_msg = msgbuf;
+	struct nb_node *nb_node;
+	struct lyd_node *input, *output;
+	const char *xpath;
+	const char *data;
+	char errmsg[BUFSIZ] = { 0 };
+	LY_ERR err;
+	int ret;
+
+	debug_be_client("Received RPC request for client %s txn-id %" PRIu64
+			" req-id %" PRIu64,
+			client->name, txn_id, rpc_msg->req_id);
+
+	xpath = mgmt_msg_native_xpath_data_decode(rpc_msg, msg_len, data);
+	if (!xpath) {
+		be_client_send_error(client, txn_id, rpc_msg->req_id, false,
+				     -EINVAL, "Corrupt RPC message");
+		return;
+	}
+
+	nb_node = nb_node_find(xpath);
+	if (!nb_node) {
+		be_client_send_error(client, txn_id, rpc_msg->req_id, false,
+				     -EINVAL, "No schema found for RPC: %s",
+				     xpath);
+		return;
+	}
+
+	if (!nb_node->cbs.rpc) {
+		be_client_send_error(client, txn_id, rpc_msg->req_id, false,
+				     -EINVAL, "No RPC callback for: %s", xpath);
+		return;
+	}
+
+	if (data) {
+		err = yang_parse_rpc(xpath, rpc_msg->request_type, data, false,
+				     &input);
+		if (err) {
+			be_client_send_error(client, txn_id, rpc_msg->req_id,
+					     false, -EINVAL,
+					     "Can't parse RPC data for: %s",
+					     xpath);
+			return;
+		}
+	} else {
+		/*
+		 * If there's no input data, create an empty input container.
+		 * It is especially needed for actions, because their parents
+		 * may hold necessary information.
+		 */
+		err = lyd_new_path2(NULL, ly_native_ctx, xpath, NULL, 0, 0, 0,
+				    NULL, &input);
+		if (err) {
+			be_client_send_error(client, txn_id, rpc_msg->req_id,
+					     false, -EINVAL,
+					     "Can't create input node for RPC: %s",
+					     xpath);
+			return;
+		}
+	}
+
+	err = lyd_new_path2(NULL, ly_native_ctx, xpath, NULL, 0, 0, 0, NULL,
+			    &output);
+	if (err) {
+		lyd_free_all(input);
+		be_client_send_error(client, txn_id, rpc_msg->req_id, false,
+				     -EINVAL,
+				     "Can't create output node for RPC: %s",
+				     xpath);
+		return;
+	}
+
+	ret = nb_callback_rpc(nb_node, xpath, input, output, errmsg,
+			      sizeof(errmsg));
+	if (ret != NB_OK) {
+		lyd_free_all(input);
+		lyd_free_all(output);
+		be_client_send_error(client, txn_id, rpc_msg->req_id, false,
+				     -EINVAL, "%s", errmsg);
+		return;
+	}
+
+	lyd_free_all(input);
+	if (!lyd_child(output)) {
+		lyd_free_all(output);
+		output = NULL;
+	}
+
+	be_client_send_rpc_reply(client, txn_id, rpc_msg->req_id,
+				 rpc_msg->request_type, output);
+}
+
 /*
  * Process the notification.
  */
@@ -975,6 +1112,9 @@ static void be_client_handle_native_msg(struct mgmt_be_client *client,
 	case MGMT_MSG_CODE_GET_TREE:
 		be_client_handle_get_tree(client, txn_id, msg, msg_len);
 		break;
+	case MGMT_MSG_CODE_RPC:
+		be_client_handle_rpc(client, txn_id, msg, msg_len);
+		break;
 	case MGMT_MSG_CODE_NOTIFY:
 		be_client_handle_notify(client, msg, msg_len);
 		break;
@@ -1040,6 +1180,9 @@ int mgmt_be_send_subscr_req(struct mgmt_be_client *client_ctx,
 	subscr_req.n_notif_xpaths = client_ctx->cbs.nnotif_xpaths;
 	subscr_req.notif_xpaths = (char **)client_ctx->cbs.notif_xpaths;
 
+	subscr_req.n_rpc_xpaths = client_ctx->cbs.nrpc_xpaths;
+	subscr_req.rpc_xpaths = (char **)client_ctx->cbs.rpc_xpaths;
+
 	mgmtd__be_message__init(&be_msg);
 	be_msg.message_case = MGMTD__BE_MESSAGE__MESSAGE_SUBSCR_REQ;
 	be_msg.subscr_req = &subscr_req;

lib/mgmt_be_client.h

@@ -75,6 +75,8 @@ struct mgmt_be_client_cbs {
 
 	const char **notif_xpaths;
 	uint nnotif_xpaths;
+	const char **rpc_xpaths;
+	uint nrpc_xpaths;
 };
 
 /***************************************************************

lib/mgmt_fe_client.c

@@ -360,6 +360,33 @@ int mgmt_fe_send_edit_req(struct mgmt_fe_client *client, uint64_t session_id,
 	return ret;
 }
 
+int mgmt_fe_send_rpc_req(struct mgmt_fe_client *client, uint64_t session_id,
+			 uint64_t req_id, LYD_FORMAT request_type,
+			 const char *xpath, const char *data)
+{
+	struct mgmt_msg_rpc *msg;
+	int ret;
+
+	msg = mgmt_msg_native_alloc_msg(struct mgmt_msg_rpc, 0,
+					MTYPE_MSG_NATIVE_RPC);
+	msg->refer_id = session_id;
+	msg->req_id = req_id;
+	msg->code = MGMT_MSG_CODE_RPC;
+	msg->request_type = request_type;
+
+	mgmt_msg_native_xpath_encode(msg, xpath);
+	if (data)
+		mgmt_msg_native_append(msg, data, strlen(data) + 1);
+
+	debug_fe_client("Sending RPC_REQ session-id %" PRIu64 " req-id %" PRIu64
+			" xpath: %s",
+			session_id, req_id, xpath);
+
+	ret = mgmt_msg_native_send_msg(&client->client.conn, msg, false);
+	mgmt_msg_native_free_msg(msg);
+	return ret;
+}
+
 static int mgmt_fe_client_handle_msg(struct mgmt_fe_client *client,
 				     Mgmtd__FeMessage *fe_msg)
 {
@@ -534,6 +561,7 @@ static void fe_client_handle_native_msg(struct mgmt_fe_client *client,
 	struct mgmt_msg_notify_data *notify_msg;
 	struct mgmt_msg_tree_data *tree_msg;
 	struct mgmt_msg_edit_reply *edit_msg;
+	struct mgmt_msg_rpc_reply *rpc_msg;
 	struct mgmt_msg_error *err_msg;
 	const char *xpath = NULL;
 	const char *data = NULL;
@@ -608,6 +636,23 @@ static void fe_client_handle_native_msg(struct mgmt_fe_client *client,
 						 session->user_ctx, msg->req_id,
 						 xpath);
 		break;
+	case MGMT_MSG_CODE_RPC_REPLY:
+		if (!session->client->cbs.rpc_notify)
+			return;
+
+		rpc_msg = (typeof(rpc_msg))msg;
+		if (msg_len < sizeof(*rpc_msg)) {
+			log_err_fe_client("Corrupt rpc-reply msg recv");
+			return;
+		}
+		dlen = msg_len - sizeof(*rpc_msg);
+
+		session->client->cbs.rpc_notify(client, client->user_data,
+						session->client_id,
+						msg->refer_id,
+						session->user_ctx, msg->req_id,
+						dlen ? rpc_msg->data : NULL);
+		break;
 	case MGMT_MSG_CODE_NOTIFY:
 		if (!session->client->cbs.async_notification)
 			return;

lib/mgmt_fe_client.h

@@ -120,6 +120,12 @@ struct mgmt_fe_client_cbs {
 			   uintptr_t session_ctx, uint64_t req_id,
 			   const char *xpath);
 
+	/* Called when RPC result is returned */
+	int (*rpc_notify)(struct mgmt_fe_client *client, uintptr_t user_data,
+			  uint64_t client_id, uint64_t session_id,
+			  uintptr_t session_ctx, uint64_t req_id,
+			  const char *result);
+
 	/* Called with asynchronous notifications from backends */
 	int (*async_notification)(struct mgmt_fe_client *client,
 				  uintptr_t user_data, uint64_t client_id,
@@ -454,6 +460,35 @@ extern int mgmt_fe_send_edit_req(struct mgmt_fe_client *client,
 				 uint8_t flags, uint8_t operation,
 				 const char *xpath, const char *data);
 
+/*
+ * Send RPC request to MGMTD daemon.
+ *
+ * client
+ *    Client object.
+ *
+ * session_id
+ *    Client session ID.
+ *
+ * req_id
+ *    Client request ID.
+ *
+ * result_type
+ *    The LYD_FORMAT of the result.
+ *
+ * xpath
+ *    the xpath of the RPC.
+ *
+ * data
+ *    the data tree.
+ *
+ * Returns:
+ *    0 on success, otherwise msg_conn_send_msg() return values.
+ */
+extern int mgmt_fe_send_rpc_req(struct mgmt_fe_client *client,
+				uint64_t session_id, uint64_t req_id,
+				LYD_FORMAT request_type, const char *xpath,
+				const char *data);
+
 /*
  * Destroy library and cleanup everything.
  */

lib/mgmt_msg_native.c

@@ -16,6 +16,8 @@ DEFINE_MTYPE(MSG_NATIVE, MSG_NATIVE_GET_DATA, "native get data msg");
 DEFINE_MTYPE(MSG_NATIVE, MSG_NATIVE_NOTIFY, "native get data msg");
 DEFINE_MTYPE(MSG_NATIVE, MSG_NATIVE_EDIT, "native edit msg");
 DEFINE_MTYPE(MSG_NATIVE, MSG_NATIVE_EDIT_REPLY, "native edit reply msg");
+DEFINE_MTYPE(MSG_NATIVE, MSG_NATIVE_RPC, "native RPC msg");
+DEFINE_MTYPE(MSG_NATIVE, MSG_NATIVE_RPC_REPLY, "native RPC reply msg");
 
 int vmgmt_msg_native_send_error(struct msg_conn *conn, uint64_t sess_or_txn_id,
 				uint64_t req_id, bool short_circuit_ok,

lib/mgmt_msg_native.h

@@ -152,6 +152,8 @@ DECLARE_MTYPE(MSG_NATIVE_GET_DATA);
 DECLARE_MTYPE(MSG_NATIVE_NOTIFY);
 DECLARE_MTYPE(MSG_NATIVE_EDIT);
 DECLARE_MTYPE(MSG_NATIVE_EDIT_REPLY);
+DECLARE_MTYPE(MSG_NATIVE_RPC);
+DECLARE_MTYPE(MSG_NATIVE_RPC_REPLY);
 
 /*
  * Native message codes
@@ -163,6 +165,8 @@ DECLARE_MTYPE(MSG_NATIVE_EDIT_REPLY);
 #define MGMT_MSG_CODE_NOTIFY	4
 #define MGMT_MSG_CODE_EDIT	 5
 #define MGMT_MSG_CODE_EDIT_REPLY 6
+#define MGMT_MSG_CODE_RPC	 7
+#define MGMT_MSG_CODE_RPC_REPLY	 8
 
 /*
  * Datastores
@@ -377,6 +381,42 @@ _Static_assert(sizeof(struct mgmt_msg_edit_reply) ==
 		       offsetof(struct mgmt_msg_edit_reply, data),
 	       "Size mismatch");
 
+/**
+ * struct mgmt_msg_rpc - RPC/action request.
+ *
+ * @request_type: ``LYD_FORMAT`` for the @data.
+ * @data: the xpath followed by the tree data for the operation.
+ */
+struct mgmt_msg_rpc {
+	struct mgmt_msg_header;
+	uint8_t request_type;
+	uint8_t resv2[7];
+
+	alignas(8) char data[];
+};
+
+_Static_assert(sizeof(struct mgmt_msg_rpc) ==
+		       offsetof(struct mgmt_msg_rpc, data),
+	       "Size mismatch");
+
+/**
+ * struct mgmt_msg_rpc_reply - RPC/action reply.
+ *
+ * @result_type: ``LYD_FORMAT`` for the @data.
+ * @data: the tree data for the reply.
+ */
+struct mgmt_msg_rpc_reply {
+	struct mgmt_msg_header;
+	uint8_t result_type;
+	uint8_t resv2[7];
+
+	alignas(8) char data[];
+};
+
+_Static_assert(sizeof(struct mgmt_msg_rpc_reply) ==
+		       offsetof(struct mgmt_msg_rpc_reply, data),
+	       "Size mismatch");
+
 /*
  * Validate that the message ends in a NUL terminating byte
  */
@@ -569,7 +609,10 @@ extern int vmgmt_msg_native_send_error(struct msg_conn *conn,
 		const char *__s = NULL;                                        \
 		if (msg->vsplit && msg->vsplit <= __len &&                     \
 		    msg->data[msg->vsplit - 1] == 0) {                         \
-			(__data) = msg->data + msg->vsplit;                    \
+			if (msg->vsplit < __len)                               \
+				(__data) = msg->data + msg->vsplit;            \
+			else                                                   \
+				(__data) = NULL;                               \
 			__s = msg->data;                                       \
 		}                                                              \
 		__s;                                                           \

lib/northbound.c

@@ -932,14 +932,22 @@ static int nb_candidate_edit_tree_add(struct nb_config *candidate,
 		/* if replace failed, restore the original node */
 		if (existing) {
 			if (root) {
+				/* Restoring the whole config. */
 				candidate->dnode = existing;
+			} else if (ex_parent) {
+				/*
+				 * Restoring a nested node. Insert it as a
+				 * child.
+				 */
+				lyd_insert_child(ex_parent, existing);
 			} else {
-				if (ex_parent)
+				/*
-					lyd_insert_child(ex_parent, existing);
+				 * Restoring a top-level node. Insert it as a
-				else
+				 * sibling to candidate->dnode to make sure
-					lyd_insert_sibling(candidate->dnode,
+				 * the linkage is correct.
-							   existing,
+				 */
-							   &candidate->dnode);
+				lyd_insert_sibling(candidate->dnode, existing,
+						   &candidate->dnode);
 			}
 		}
 		yang_print_errors(ly_native_ctx, errmsg, errmsg_len);
@@ -1820,14 +1828,11 @@ const void *nb_callback_lookup_next(const struct nb_node *nb_node,
 }
 
 int nb_callback_rpc(const struct nb_node *nb_node, const char *xpath,
-		    const struct list *input, struct list *output, char *errmsg,
+		    const struct lyd_node *input, struct lyd_node *output,
-		    size_t errmsg_len)
+		    char *errmsg, size_t errmsg_len)
 {
 	struct nb_cb_rpc_args args = {};
 
-	if (CHECK_FLAG(nb_node->flags, F_NB_NODE_IGNORE_CFG_CBS))
-		return 0;
-
 	DEBUGD(&nb_dbg_cbs_rpc, "northbound RPC: %s", xpath);
 
 	args.xpath = xpath;

lib/northbound.h

@@ -274,11 +274,11 @@ struct nb_cb_rpc_args {
 	/* XPath of the YANG RPC or action. */
 	const char *xpath;
 
-	/* Read-only list of input parameters. */
+	/* Read-only "input" tree of the RPC/action. */
-	const struct list *input;
+	const struct lyd_node *input;
 
-	/* List of output parameters to be populated by the callback. */
+	/* The "output" tree of the RPC/action to be populated by the callback. */
-	struct list *output;
+	struct lyd_node *output;
 
 	/* Buffer to store human-readable error message in case of error. */
 	char *errmsg;
@@ -833,7 +833,7 @@ extern const void *nb_callback_lookup_next(const struct nb_node *nb_node,
 					   const void *parent_list_entry,
 					   const struct yang_list_keys *keys);
 extern int nb_callback_rpc(const struct nb_node *nb_node, const char *xpath,
-			   const struct list *input, struct list *output,
+			   const struct lyd_node *input, struct lyd_node *output,
 			   char *errmsg, size_t errmsg_len);
 extern void nb_callback_notify(const struct nb_node *nb_node, const char *xpath,
 			       struct lyd_node *dnode);

lib/northbound_cli.c

@@ -275,10 +275,31 @@ int nb_cli_apply_changes_clear_pending(struct vty *vty,
 	return nb_cli_apply_changes_internal(vty, xpath_base_abs, true);
 }
 
-int nb_cli_rpc(struct vty *vty, const char *xpath, struct list *input,
+int nb_cli_rpc_enqueue(struct vty *vty, const char *xpath, const char *value)
-	       struct list *output)
+{
+	struct nb_cfg_change *param;
+
+	if (vty->num_rpc_params == VTY_MAXCFGCHANGES) {
+		/* Not expected to happen. */
+		vty_out(vty,
+			"%% Exceeded the maximum number of params (%u) for a single command\n\n",
+			VTY_MAXCFGCHANGES);
+		return CMD_WARNING;
+	}
+
+	param = &vty->rpc_params[vty->num_rpc_params++];
+	strlcpy(param->xpath, xpath, sizeof(param->xpath));
+	param->value = value;
+
+	return CMD_SUCCESS;
+}
+
+int nb_cli_rpc(struct vty *vty, const char *xpath, struct lyd_node **output_p)
 {
 	struct nb_node *nb_node;
+	struct lyd_node *input = NULL;
+	struct lyd_node *output = NULL;
+	LY_ERR err;
 	int ret;
 	char errmsg[BUFSIZ] = {0};
 
@@ -289,12 +310,62 @@ int nb_cli_rpc(struct vty *vty, const char *xpath, struct list *input,
 		return CMD_WARNING;
 	}
 
+	/* create input tree */
+	err = lyd_new_path2(NULL, ly_native_ctx, xpath, NULL, 0, 0, 0, NULL,
+			    &input);
+	assert(err == LY_SUCCESS);
+
+	for (size_t i = 0; i < vty->num_rpc_params; i++) {
+		err = lyd_new_path(input, ly_native_ctx,
+				   vty->rpc_params[i].xpath,
+				   vty->rpc_params[i].value, 0, NULL);
+		assert(err == LY_SUCCESS);
+	}
+
+	if (vty_mgmt_fe_enabled()) {
+		char *data = NULL;
+
+		err = lyd_print_mem(&data, input, LYD_JSON, LYD_PRINT_SHRINK);
+		assert(err == LY_SUCCESS);
+
+		ret = vty_mgmt_send_rpc_req(vty, LYD_JSON, xpath, data);
+
+		free(data);
+		lyd_free_all(input);
+
+		if (ret < 0)
+			return CMD_WARNING;
+		return CMD_SUCCESS;
+	}
+
+	/* validate input tree to create implicit defaults */
+	err = lyd_validate_op(input, NULL, LYD_TYPE_RPC_YANG, NULL);
+	assert(err == LY_SUCCESS);
+
+	/* create output tree root for population in the callback */
+	err = lyd_new_path2(NULL, ly_native_ctx, xpath, NULL, 0, 0, 0, NULL,
+			    &output);
+	assert(err == LY_SUCCESS);
+
 	ret = nb_callback_rpc(nb_node, xpath, input, output, errmsg,
 			      sizeof(errmsg));
+
+	/* validate output tree to create implicit defaults */
+	err = lyd_validate_op(output, NULL, LYD_TYPE_REPLY_YANG, NULL);
+	assert(err == LY_SUCCESS);
+
+	lyd_free_all(input);
+	vty->num_rpc_params = 0;
+
 	switch (ret) {
 	case NB_OK:
+		if (output_p)
+			*output_p = output;
+		else
+			lyd_free_all(output);
 		return CMD_SUCCESS;
 	default:
+		lyd_free_all(output);
 		if (strlen(errmsg))
 			vty_show_nb_errors(vty, ret, errmsg);
 		return CMD_WARNING;

lib/northbound_cli.h

@@ -80,7 +80,23 @@ extern int nb_cli_apply_changes(struct vty *vty, const char *xpath_base_fmt,
 				...) PRINTFRR(2, 3);
 
 /*
- * Execute a YANG RPC or Action.
+ * Add an input child node for an RPC or an action.
+ *
+ * vty
+ *    The vty context.
+ *
+ * xpath
+ *    XPath of the child being added, relative to the input container.
+ *
+ * value
+ *    Value of the child being added. Can be NULL for containers and leafs of
+ *    type 'empty'.
+ */
+extern int nb_cli_rpc_enqueue(struct vty *vty, const char *xpath,
+			      const char *value);
+
+/*
+ * Execute a YANG RPC or Action using the enqueued input parameters.
  *
  * vty
  *    The vty terminal to dump any error.
@@ -88,20 +104,16 @@ extern int nb_cli_apply_changes(struct vty *vty, const char *xpath_base_fmt,
  * xpath
  *    XPath of the YANG RPC or Action node.
  *
- * input
+ * output_p
- *    List of 'yang_data' structures containing the RPC input parameters. It
+ *    A pointer to the libyang data node that will hold the output data tree.
- *    can be set to NULL when there are no input parameters.
+ *    It can be set to NULL if the caller is not interested in processing the
- *
+ *    output. The caller is responsible for freeing the output data tree.
- * output
- *    List of 'yang_data' structures used to retrieve the RPC output parameters.
- *    It can be set to NULL when it's known that the given YANG RPC or Action
- *    doesn't have any output parameters.
  *
  * Returns:
  *    CMD_SUCCESS on success, CMD_WARNING otherwise.
  */
-extern int nb_cli_rpc(struct vty *vty, const char *xpath, struct list *input,
+extern int nb_cli_rpc(struct vty *vty, const char *xpath,
-		      struct list *output);
+		      struct lyd_node **output_p);
 
 /*
  * Show CLI commands associated to the given YANG data node.

lib/northbound_grpc.cpp

@@ -1011,12 +1011,11 @@ grpc::Status HandleUnaryExecute(
 	grpc_debug("%s: entered", __func__);
 
 	struct nb_node *nb_node;
-	struct list *input_list;
+	struct lyd_node *input_tree, *output_tree, *child;
-	struct list *output_list;
-	struct listnode *node;
-	struct yang_data *data;
 	const char *xpath;
 	char errmsg[BUFSIZ] = {0};
+	char path[XPATH_MAXLEN];
+	LY_ERR err;
 
 	// Request: string path = 1;
 	xpath = tag->request.path().c_str();
@@ -1032,40 +1031,66 @@ grpc::Status HandleUnaryExecute(
 		return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
 				    "Unknown data path");
 
-	input_list = yang_data_list_new();
+	// Create input data tree.
-	output_list = yang_data_list_new();
+	err = lyd_new_path2(NULL, ly_native_ctx, xpath, NULL, 0,
+			    (LYD_ANYDATA_VALUETYPE)0, 0, NULL, &input_tree);
+	if (err != LY_SUCCESS) {
+		return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
+				    "Invalid data path");
+	}
 
 	// Read input parameters.
 	auto input = tag->request.input();
 	for (const frr::PathValue &pv : input) {
 		// Request: repeated PathValue input = 2;
-		data = yang_data_new(pv.path().c_str(), pv.value().c_str());
+		err = lyd_new_path(input_tree, ly_native_ctx, pv.path().c_str(),
-		listnode_add(input_list, data);
+				   pv.value().c_str(), 0, NULL);
+		if (err != LY_SUCCESS) {
+			lyd_free_tree(input_tree);
+			return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
+					    "Invalid input data");
+		}
+	}
+
+	// Validate input data.
+	err = lyd_validate_op(input_tree, NULL, LYD_TYPE_RPC_YANG, NULL);
+	if (err != LY_SUCCESS) {
+		lyd_free_tree(input_tree);
+		return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
+				    "Invalid input data");
+	}
+
+	// Create output data tree.
+	err = lyd_new_path2(NULL, ly_native_ctx, xpath, NULL, 0,
+			    (LYD_ANYDATA_VALUETYPE)0, 0, NULL, &output_tree);
+	if (err != LY_SUCCESS) {
+		lyd_free_tree(input_tree);
+		return grpc::Status(grpc::StatusCode::INVALID_ARGUMENT,
+				    "Invalid data path");
 	}
 
 	// Execute callback registered for this XPath.
-	if (nb_callback_rpc(nb_node, xpath, input_list, output_list, errmsg,
+	if (nb_callback_rpc(nb_node, xpath, input_tree, output_tree, errmsg,
-			    sizeof(errmsg))
+			    sizeof(errmsg)) != NB_OK) {
-	    != NB_OK) {
 		flog_warn(EC_LIB_NB_CB_RPC, "%s: rpc callback failed: %s",
 			  __func__, xpath);
-		list_delete(&input_list);
+		lyd_free_tree(input_tree);
-		list_delete(&output_list);
+		lyd_free_tree(output_tree);
 
 		return grpc::Status(grpc::StatusCode::INTERNAL, "RPC failed");
 	}
 
 	// Process output parameters.
-	for (ALL_LIST_ELEMENTS_RO(output_list, node, data)) {
+	LY_LIST_FOR (lyd_child(output_tree), child) {
 		// Response: repeated PathValue output = 1;
 		frr::PathValue *pv = tag->response.add_output();
-		pv->set_path(data->xpath);
+		pv->set_path(lyd_path(child, LYD_PATH_STD, path, sizeof(path)));
-		pv->set_value(data->value);
+		pv->set_value(yang_dnode_get_string(child, NULL));
 	}
 
 	// Release memory.
-	list_delete(&input_list);
+	lyd_free_tree(input_tree);
-	list_delete(&output_list);
+	lyd_free_tree(output_tree);
 
 	return grpc::Status::OK;
 }

lib/northbound_sysrepo.c

@@ -377,16 +377,11 @@ static int frr_sr_state_cb(sr_session_ctx_t *session, uint32_t sub_id,
 	return SR_ERR_OK;
 }
 static int frr_sr_config_rpc_cb(sr_session_ctx_t *session, uint32_t sub_id,
-				const char *xpath, const sr_val_t *sr_input,
+				const char *xpath, const struct lyd_node *input,
-				const size_t input_cnt, sr_event_t sr_ev,
+				sr_event_t sr_ev, uint32_t request_id,
-				uint32_t request_id, sr_val_t **sr_output,
+				struct lyd_node *output, void *private_ctx)
-				size_t *sr_output_cnt, void *private_ctx)
 {
 	struct nb_node *nb_node;
-	struct list *input;
-	struct list *output;
-	struct yang_data *data;
-	size_t cb_output_cnt;
 	int ret = SR_ERR_OK;
 	char errmsg[BUFSIZ] = {0};
 
@@ -397,19 +392,6 @@ static int frr_sr_config_rpc_cb(sr_session_ctx_t *session, uint32_t sub_id,
 		return SR_ERR_INTERNAL;
 	}
 
-	input = yang_data_list_new();
-	output = yang_data_list_new();
-
-	/* Process input. */
-	for (size_t i = 0; i < input_cnt; i++) {
-		char value_str[YANG_VALUE_MAXLEN];
-
-		sr_val_to_buff(&sr_input[i], value_str, sizeof(value_str));
-
-		data = yang_data_new(xpath, value_str);
-		listnode_add(input, data);
-	}
-
 	/* Execute callback registered for this XPath. */
 	if (nb_callback_rpc(nb_node, xpath, input, output, errmsg,
 			    sizeof(errmsg))
@@ -417,44 +399,8 @@ static int frr_sr_config_rpc_cb(sr_session_ctx_t *session, uint32_t sub_id,
 		flog_warn(EC_LIB_NB_CB_RPC, "%s: rpc callback failed: %s",
 			  __func__, xpath);
 		ret = SR_ERR_OPERATION_FAILED;
-		goto exit;
 	}
 
-	/* Process output. */
-	if (listcount(output) > 0) {
-		sr_val_t *values = NULL;
-		struct listnode *node;
-		int i = 0;
-
-		cb_output_cnt = listcount(output);
-		ret = sr_new_values(cb_output_cnt, &values);
-		if (ret != SR_ERR_OK) {
-			flog_err(EC_LIB_LIBSYSREPO, "%s: sr_new_values(): %s",
-				 __func__, sr_strerror(ret));
-			goto exit;
-		}
-
-		for (ALL_LIST_ELEMENTS_RO(output, node, data)) {
-			if (yang_data_frr2sr(data, &values[i++]) != 0) {
-				flog_err(
-					EC_LIB_SYSREPO_DATA_CONVERT,
-					"%s: failed to convert data to Sysrepo format",
-					__func__);
-				ret = SR_ERR_INTERNAL;
-				sr_free_values(values, cb_output_cnt);
-				goto exit;
-			}
-		}
-
-		*sr_output = values;
-		*sr_output_cnt = cb_output_cnt;
-	}
-
-exit:
-	/* Release memory. */
-	list_delete(&input);
-	list_delete(&output);
-
 	return ret;
 }
 
@@ -579,8 +525,9 @@ static int frr_sr_subscribe_rpc(const struct lysc_node *snode, void *arg)
 	DEBUGD(&nb_dbg_client_sysrepo, "sysrepo: providing RPC to '%s'",
 	       nb_node->xpath);
 
-	ret = sr_rpc_subscribe(session, nb_node->xpath, frr_sr_config_rpc_cb,
+	ret = sr_rpc_subscribe_tree(session, nb_node->xpath,
-			       NULL, 0, 0, &module->sr_subscription);
+				    frr_sr_config_rpc_cb, NULL, 0, 0,
+				    &module->sr_subscription);
 	if (ret != SR_ERR_OK)
 		flog_err(EC_LIB_LIBSYSREPO, "sr_rpc_subscribe(): %s",
 			 sr_strerror(ret));

lib/vty.c

@@ -3843,6 +3843,26 @@ static int vty_mgmt_edit_result_notified(struct mgmt_fe_client *client,
 	return 0;
 }
 
+static int vty_mgmt_rpc_result_notified(struct mgmt_fe_client *client,
+					uintptr_t user_data, uint64_t client_id,
+					uint64_t session_id,
+					uintptr_t session_ctx, uint64_t req_id,
+					const char *result)
+{
+	struct vty *vty = (struct vty *)session_ctx;
+
+	debug_fe_client("RPC request for client 0x%" PRIx64 " req-id %" PRIu64
+			" was successful",
+			client_id, req_id);
+
+	if (result)
+		vty_out(vty, "%s\n", result);
+
+	vty_mgmt_resume_response(vty, CMD_SUCCESS);
+
+	return 0;
+}
+
 static int vty_mgmt_error_notified(struct mgmt_fe_client *client,
 				   uintptr_t user_data, uint64_t client_id,
 				   uint64_t session_id, uintptr_t session_ctx,
@@ -3885,6 +3905,7 @@ static struct mgmt_fe_client_cbs mgmt_cbs = {
 	.get_data_notify = vty_mgmt_get_data_result_notified,
 	.get_tree_notify = vty_mgmt_get_tree_result_notified,
 	.edit_notify = vty_mgmt_edit_result_notified,
+	.rpc_notify = vty_mgmt_rpc_result_notified,
 	.error_notify = vty_mgmt_error_notified,
 
 };
@@ -4162,6 +4183,25 @@ int vty_mgmt_send_edit_req(struct vty *vty, uint8_t datastore,
 	return 0;
 }
 
+int vty_mgmt_send_rpc_req(struct vty *vty, LYD_FORMAT request_type,
+			  const char *xpath, const char *data)
+{
+	vty->mgmt_req_id++;
+
+	if (mgmt_fe_send_rpc_req(mgmt_fe_client, vty->mgmt_session_id,
+				 vty->mgmt_req_id, request_type, xpath, data)) {
+		zlog_err("Failed to send RPC to MGMTD session-id: %" PRIu64
+			 " req-id %" PRIu64 ".",
+			 vty->mgmt_session_id, vty->mgmt_req_id);
+		vty_out(vty, "Failed to send RPC to MGMTD!\n");
+		return -1;
+	}
+
+	vty->mgmt_req_pending_cmd = "MESSAGE_RPC_REQ";
+
+	return 0;
+}
+
 /* Install vty's own commands like `who' command. */
 void vty_init(struct event_loop *master_thread, bool do_command_logging)
 {

lib/vty.h

@@ -122,6 +122,10 @@ struct vty {
 	size_t num_cfg_changes;
 	struct nb_cfg_change cfg_changes[VTY_MAXCFGCHANGES];
 
+	/* Input parameters */
+	size_t num_rpc_params;
+	struct nb_cfg_change rpc_params[VTY_MAXCFGCHANGES];
+
 	/* XPath of the current node */
 	int xpath_index;
 	char xpath[VTY_MAXDEPTH][XPATH_MAXLEN];
@@ -423,6 +427,8 @@ extern int vty_mgmt_send_edit_req(struct vty *vty, uint8_t datastore,
 				  LYD_FORMAT request_type, uint8_t flags,
 				  uint8_t operation, const char *xpath,
 				  const char *data);
+extern int vty_mgmt_send_rpc_req(struct vty *vty, LYD_FORMAT request_type,
+				 const char *xpath, const char *data);
 extern int vty_mgmt_send_lockds_req(struct vty *vty, Mgmtd__DatastoreId ds_id,
 				    bool lock, bool scok);
 extern void vty_mgmt_resume_response(struct vty *vty, int ret);

lib/yang.c

@@ -653,6 +653,16 @@ void yang_dnode_free(struct lyd_node *dnode)
 	lyd_free_all(dnode);
 }
 
+void yang_dnode_rpc_output_add(struct lyd_node *output, const char *xpath,
+			       const char *value)
+{
+	LY_ERR err;
+
+	err = lyd_new_path(output, ly_native_ctx, xpath, value,
+			   LYD_NEW_PATH_OUTPUT | LYD_NEW_PATH_UPDATE, NULL);
+	assert(err == LY_SUCCESS);
+}
+
 struct yang_data *yang_data_new(const char *xpath, const char *value)
 {
 	struct yang_data *data;
@@ -764,6 +774,63 @@ LY_ERR yang_parse_notification(const char *xpath, LYD_FORMAT format,
 	return LY_SUCCESS;
 }
 
+LY_ERR yang_parse_rpc(const char *xpath, LYD_FORMAT format, const char *data,
+		      bool reply, struct lyd_node **rpc)
+{
+	const struct lysc_node *snode;
+	struct lyd_node *parent = NULL;
+	struct ly_in *in = NULL;
+	LY_ERR err;
+
+	snode = lys_find_path(ly_native_ctx, NULL, xpath, 0);
+	if (!snode) {
+		zlog_err("Failed to find RPC/action schema node: %s", xpath);
+		return LY_ENOTFOUND;
+	}
+
+	/* If it's an action, create its parent */
+	if (snode->nodetype == LYS_ACTION) {
+		char *parent_xpath = XSTRDUP(MTYPE_TMP, xpath);
+
+		if (yang_xpath_pop_node(parent_xpath) != NB_OK) {
+			XFREE(MTYPE_TMP, parent_xpath);
+			zlog_err("Invalid action xpath: %s", xpath);
+			return LY_EINVAL;
+		}
+
+		err = lyd_new_path2(NULL, ly_native_ctx, parent_xpath, NULL, 0,
+				    0, 0, NULL, &parent);
+		XFREE(MTYPE_TMP, parent_xpath);
+		if (err) {
+			zlog_err("Failed to create parent node for action: %s",
+				 ly_last_errmsg());
+			return err;
+		}
+	} else if (snode->nodetype != LYS_RPC) {
+		zlog_err("Schema node is not an RPC/action: %s", xpath);
+		return LY_EINVAL;
+	}
+
+	err = ly_in_new_memory(data, &in);
+	if (err) {
+		lyd_free_all(parent);
+		zlog_err("Failed to initialize ly_in: %s", ly_last_errmsg());
+		return err;
+	}
+
+	err = lyd_parse_op(ly_native_ctx, parent, in, format,
+			   reply ? LYD_TYPE_REPLY_YANG : LYD_TYPE_RPC_YANG,
+			   NULL, rpc);
+	ly_in_free(in, 0);
+	if (err) {
+		lyd_free_all(parent);
+		zlog_err("Failed to parse RPC/action: %s", ly_last_errmsg());
+		return err;
+	}
+
+	return LY_SUCCESS;
+}
+
 static ssize_t yang_print_darr(void *arg, const void *buf, size_t count)
 {
 	uint8_t *dst = darr_append_n(*(uint8_t **)arg, count);

lib/yang.h

@@ -535,6 +535,21 @@ extern struct lyd_node *yang_dnode_dup(const struct lyd_node *dnode);
  */
 extern void yang_dnode_free(struct lyd_node *dnode);
 
+/*
+ * Add a libyang data node to an RPC/action output container.
+ *
+ * output
+ *    RPC/action output container.
+ *
+ * xpath
+ *    XPath of the data node to add, relative to the output container.
+ *
+ * value
+ *    String representing the value of the data node.
+ */
+extern void yang_dnode_rpc_output_add(struct lyd_node *output,
+				      const char *xpath, const char *value);
+
 /*
  * Create a new yang_data structure.
  *
@@ -619,6 +634,25 @@ extern void yang_debugging_set(bool enable);
 extern LY_ERR yang_parse_notification(const char *xpath, LYD_FORMAT format,
 				      const char *data, struct lyd_node **notif);
 
+/*
+ * Parse a YANG RPC.
+ *
+ * Args:
+ *	xpath: xpath of an RPC/action.
+ *	format: LYD_FORMAT of input data.
+ *	data: input data.
+ *	reply: true if the data represents a reply to an RPC/action.
+ *	rpc: pointer to the libyang data tree to store the parsed RPC/action.
+ *	     If data represents an action, the pointer to the action node is
+ *	     still returned, but it's part of the full data tree with all its
+ *	     parents.
+ *
+ * Returns:
+ *	LY_ERR from underlying calls.
+ */
+LY_ERR yang_parse_rpc(const char *xpath, LYD_FORMAT format, const char *data,
+		      bool reply, struct lyd_node **rpc);
+
 /*
  * "Print" the yang tree in `root` into dynamic sized array.
  *

mgmtd/mgmt_be_adapter.c

@@ -98,6 +98,10 @@ static const char *const ripd_oper_xpaths[] = {
 	"/ietf-key-chain:key-chains",
 	NULL,
 };
+static const char *const ripd_rpc_xpaths[] = {
+	"/frr-ripd",
+	NULL,
+};
 #endif
 
 #if HAVE_RIPNGD
@@ -113,6 +117,10 @@ static const char *const ripngd_oper_xpaths[] = {
 	"/frr-ripngd:ripngd",
 	NULL,
 };
+static const char *const ripngd_rpc_xpaths[] = {
+	"/frr-ripngd",
+	NULL,
+};
 #endif
 
 #if HAVE_STATICD
@@ -147,6 +155,15 @@ static const char *const *be_client_oper_xpaths[MGMTD_BE_CLIENT_ID_MAX] = {
 	[MGMTD_BE_CLIENT_ID_ZEBRA] = zebra_oper_xpaths,
 };
 
+static const char *const *be_client_rpc_xpaths[MGMTD_BE_CLIENT_ID_MAX] = {
+#ifdef HAVE_RIPD
+	[MGMTD_BE_CLIENT_ID_RIPD] = ripd_rpc_xpaths,
+#endif
+#ifdef HAVE_RIPNGD
+	[MGMTD_BE_CLIENT_ID_RIPNGD] = ripngd_rpc_xpaths,
+#endif
+};
+
 /*
  * We would like to have a better ADT than one with O(n) comparisons
  *
@@ -159,6 +176,7 @@ static const char *const *be_client_oper_xpaths[MGMTD_BE_CLIENT_ID_MAX] = {
 static struct mgmt_be_xpath_map *be_cfg_xpath_map;
 static struct mgmt_be_xpath_map *be_oper_xpath_map;
 static struct mgmt_be_xpath_map *be_notif_xpath_map;
+static struct mgmt_be_xpath_map *be_rpc_xpath_map;
 
 static struct event_loop *mgmt_loop;
 static struct msg_server mgmt_be_server = {.fd = -1};
@@ -173,8 +191,8 @@ static struct mgmt_be_client_adapter
 static void
 mgmt_be_adapter_sched_init_event(struct mgmt_be_client_adapter *adapter);
 
-static bool be_is_client_interested(const char *xpath,
+static bool be_is_client_interested(const char *xpath, enum mgmt_be_client_id id,
-				    enum mgmt_be_client_id id, bool config);
+				    enum mgmt_be_xpath_subscr_type type);
 
 const char *mgmt_be_client_id2name(enum mgmt_be_client_id id)
 {
@@ -223,16 +241,25 @@ mgmt_be_find_adapter_by_name(const char *name)
 }
 
 static void mgmt_register_client_xpath(enum mgmt_be_client_id id,
-				       const char *xpath, bool config, bool oper)
+				       const char *xpath,
+				       enum mgmt_be_xpath_subscr_type type)
 {
 	struct mgmt_be_xpath_map **maps, *map;
 
-	if (config)
+	switch (type) {
+	case MGMT_BE_XPATH_SUBSCR_TYPE_CFG:
 		maps = &be_cfg_xpath_map;
-	else if (oper)
+		break;
+	case MGMT_BE_XPATH_SUBSCR_TYPE_OPER:
 		maps = &be_oper_xpath_map;
-	else
+		break;
+	case MGMT_BE_XPATH_SUBSCR_TYPE_NOTIF:
 		maps = &be_notif_xpath_map;
+		break;
+	case MGMT_BE_XPATH_SUBSCR_TYPE_RPC:
+		maps = &be_rpc_xpath_map;
+		break;
+	}
 
 	darr_foreach_p (*maps, map) {
 		if (!strcmp(xpath, map->xpath_prefix)) {
@@ -260,18 +287,28 @@ static void mgmt_be_xpath_map_init(void)
 		/* Initialize the common config init map */
 		for (init = be_client_config_xpaths[id]; init && *init; init++) {
 			__dbg(" - CFG XPATH: '%s'", *init);
-			mgmt_register_client_xpath(id, *init, true, false);
+			mgmt_register_client_xpath(id, *init,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_CFG);
 		}
 
 		/* Initialize the common oper init map */
 		for (init = be_client_oper_xpaths[id]; init && *init; init++) {
 			__dbg(" - OPER XPATH: '%s'", *init);
-			mgmt_register_client_xpath(id, *init, false, true);
+			mgmt_register_client_xpath(id, *init,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_OPER);
+		}
+
+		/* Initialize the common RPC init map */
+		for (init = be_client_rpc_xpaths[id]; init && *init; init++) {
+			__dbg(" - RPC XPATH: '%s'", *init);
+			mgmt_register_client_xpath(id, *init,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_RPC);
 		}
 	}
 
 	__dbg("Total Cfg XPath Maps: %u", darr_len(be_cfg_xpath_map));
 	__dbg("Total Oper XPath Maps: %u", darr_len(be_oper_xpath_map));
+	__dbg("Total RPC XPath Maps: %u", darr_len(be_rpc_xpath_map));
 }
 
 static void mgmt_be_xpath_map_cleanup(void)
@@ -289,6 +326,10 @@ static void mgmt_be_xpath_map_cleanup(void)
 	darr_foreach_p (be_notif_xpath_map, map)
 		XFREE(MTYPE_MGMTD_XPATH, map->xpath_prefix);
 	darr_free(be_notif_xpath_map);
+
+	darr_foreach_p (be_rpc_xpath_map, map)
+		XFREE(MTYPE_MGMTD_XPATH, map->xpath_prefix);
+	darr_free(be_rpc_xpath_map);
 }
 
 
@@ -405,11 +446,12 @@ mgmt_be_adapter_handle_msg(struct mgmt_be_client_adapter *adapter,
 	 */
 	switch ((int)be_msg->message_case) {
 	case MGMTD__BE_MESSAGE__MESSAGE_SUBSCR_REQ:
-		__dbg("Got SUBSCR_REQ from '%s' to register xpaths config: %zu oper: %zu notif: %zu",
+		__dbg("Got SUBSCR_REQ from '%s' to register xpaths config: %zu oper: %zu notif: %zu rpc: %zu",
 		      be_msg->subscr_req->client_name,
 		      be_msg->subscr_req->n_config_xpaths,
 		      be_msg->subscr_req->n_oper_xpaths,
-		      be_msg->subscr_req->n_notif_xpaths);
+		      be_msg->subscr_req->n_notif_xpaths,
+		      be_msg->subscr_req->n_rpc_xpaths);
 
 		if (strlen(be_msg->subscr_req->client_name)) {
 			strlcpy(adapter->name, be_msg->subscr_req->client_name,
@@ -432,22 +474,29 @@ mgmt_be_adapter_handle_msg(struct mgmt_be_client_adapter *adapter,
 		num = be_msg->subscr_req->n_config_xpaths;
 		for (i = 0; i < num; i++) {
 			xpath = be_msg->subscr_req->config_xpaths[i];
-			mgmt_register_client_xpath(adapter->id, xpath, true,
+			mgmt_register_client_xpath(adapter->id, xpath,
-						   false);
+						   MGMT_BE_XPATH_SUBSCR_TYPE_CFG);
 		}
 
 		num = be_msg->subscr_req->n_oper_xpaths;
 		for (i = 0; i < num; i++) {
 			xpath = be_msg->subscr_req->oper_xpaths[i];
-			mgmt_register_client_xpath(adapter->id, xpath, false,
+			mgmt_register_client_xpath(adapter->id, xpath,
-						   true);
+						   MGMT_BE_XPATH_SUBSCR_TYPE_OPER);
 		}
 
 		num = be_msg->subscr_req->n_notif_xpaths;
 		for (i = 0; i < num; i++) {
 			xpath = be_msg->subscr_req->notif_xpaths[i];
-			mgmt_register_client_xpath(adapter->id, xpath, false,
+			mgmt_register_client_xpath(adapter->id, xpath,
-						   false);
+						   MGMT_BE_XPATH_SUBSCR_TYPE_NOTIF);
+		}
+
+		num = be_msg->subscr_req->n_rpc_xpaths;
+		for (i = 0; i < num; i++) {
+			xpath = be_msg->subscr_req->rpc_xpaths[i];
+			mgmt_register_client_xpath(adapter->id, xpath,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_RPC);
 		}
 
 		mgmt_be_send_subscr_reply(adapter, true);
@@ -638,6 +687,7 @@ static void be_adapter_handle_native_msg(struct mgmt_be_client_adapter *adapter,
 {
 	struct mgmt_msg_notify_data *notify_msg;
 	struct mgmt_msg_tree_data *tree_msg;
+	struct mgmt_msg_rpc_reply *rpc_msg;
 	struct mgmt_msg_error *error_msg;
 
 	/* get the transaction */
@@ -662,6 +712,15 @@ static void be_adapter_handle_native_msg(struct mgmt_be_client_adapter *adapter,
 		/* Forward the reply to the txn module */
 		mgmt_txn_notify_tree_data_reply(adapter, tree_msg, msg_len);
 		break;
+	case MGMT_MSG_CODE_RPC_REPLY:
+		/* RPC reply from a backend client */
+		rpc_msg = (typeof(rpc_msg))msg;
+		__dbg("Got RPC_REPLY from '%s' txn-id %" PRIx64, adapter->name,
+		      msg->refer_id);
+
+		/* Forward the reply to the txn module */
+		mgmt_txn_notify_rpc_reply(adapter, rpc_msg, msg_len);
+		break;
 	case MGMT_MSG_CODE_NOTIFY:
 		notify_msg = (typeof(notify_msg))msg;
 		__dbg("Got NOTIFY from '%s'", adapter->name);
@@ -882,7 +941,8 @@ void mgmt_be_get_adapter_config(struct mgmt_be_client_adapter *adapter,
 				goto walk_cont;
 
 			xpath = lyd_path(dnode, LYD_PATH_STD, NULL, 0);
-			if (be_is_client_interested(xpath, adapter->id, true))
+			if (be_is_client_interested(xpath, adapter->id,
+						    MGMT_BE_XPATH_SUBSCR_TYPE_CFG))
 				nb_config_diff_add_change(*changes, NB_CB_CREATE, &seq, dnode);
 			else
 				LYD_TREE_DFS_continue = 1; /* skip any subtree */
@@ -893,13 +953,27 @@ void mgmt_be_get_adapter_config(struct mgmt_be_client_adapter *adapter,
 	}
 }
 
-uint64_t mgmt_be_interested_clients(const char *xpath, bool config)
+uint64_t mgmt_be_interested_clients(const char *xpath,
+				    enum mgmt_be_xpath_subscr_type type)
 {
-	struct mgmt_be_xpath_map *maps, *map;
+	struct mgmt_be_xpath_map *maps = NULL, *map;
 	enum mgmt_be_client_id id;
 	uint64_t clients;
 
-	maps = config ? be_cfg_xpath_map : be_oper_xpath_map;
+	switch (type) {
+	case MGMT_BE_XPATH_SUBSCR_TYPE_CFG:
+		maps = be_cfg_xpath_map;
+		break;
+	case MGMT_BE_XPATH_SUBSCR_TYPE_OPER:
+		maps = be_oper_xpath_map;
+		break;
+	case MGMT_BE_XPATH_SUBSCR_TYPE_NOTIF:
+		maps = be_notif_xpath_map;
+		break;
+	case MGMT_BE_XPATH_SUBSCR_TYPE_RPC:
+		maps = be_rpc_xpath_map;
+		break;
+	}
 
 	clients = 0;
 
@@ -928,8 +1002,8 @@ uint64_t mgmt_be_interested_clients(const char *xpath, bool config)
  * Returns:
  *     Interested or not.
  */
-static bool be_is_client_interested(const char *xpath,
+static bool be_is_client_interested(const char *xpath, enum mgmt_be_client_id id,
-				    enum mgmt_be_client_id id, bool config)
+				    enum mgmt_be_xpath_subscr_type type)
 {
 	uint64_t clients;
 
@@ -938,7 +1012,7 @@ static bool be_is_client_interested(const char *xpath,
 	__dbg("Checking client: %s for xpath: '%s'", mgmt_be_client_id2name(id),
 	      xpath);
 
-	clients = mgmt_be_interested_clients(xpath, config);
+	clients = mgmt_be_interested_clients(xpath, type);
 	if (IS_IDBIT_SET(clients, id)) {
 		__dbg("client: %s: interested", mgmt_be_client_id2name(id));
 		return true;
@@ -998,23 +1072,32 @@ void mgmt_be_xpath_register_write(struct vty *vty)
 		darr_len(be_oper_xpath_map));
 	darr_foreach_p (be_oper_xpath_map, map)
 		be_show_xpath_register(vty, map);
+
+	vty_out(vty, "\nMGMTD Backend RPC XPath Registry: Count: %u\n",
+		darr_len(be_rpc_xpath_map));
+	darr_foreach_p (be_rpc_xpath_map, map)
+		be_show_xpath_register(vty, map);
 }
 
 void mgmt_be_show_xpath_registries(struct vty *vty, const char *xpath)
 {
 	enum mgmt_be_client_id id;
 	struct mgmt_be_client_adapter *adapter;
-	uint64_t cclients, oclients, combined;
+	uint64_t cclients, oclients, rclients, combined;
 
-	cclients = mgmt_be_interested_clients(xpath, true);
+	cclients = mgmt_be_interested_clients(xpath,
-	oclients = mgmt_be_interested_clients(xpath, false);
+					      MGMT_BE_XPATH_SUBSCR_TYPE_CFG);
+	oclients = mgmt_be_interested_clients(xpath,
+					      MGMT_BE_XPATH_SUBSCR_TYPE_OPER);
+	rclients = mgmt_be_interested_clients(xpath,
+					      MGMT_BE_XPATH_SUBSCR_TYPE_RPC);
 	combined = cclients | oclients;
 
 	vty_out(vty, "XPath: '%s'\n", xpath);
 	FOREACH_BE_CLIENT_BITS (id, combined) {
-		vty_out(vty, "  -- Client: '%s'\tconfig:%d oper:%d\n",
+		vty_out(vty, "  -- Client: '%s'\tconfig:%d oper:%d rpc:%d\n",
 			mgmt_be_client_id2name(id), IS_IDBIT_SET(cclients, id),
-			IS_IDBIT_SET(oclients, id));
+			IS_IDBIT_SET(oclients, id), IS_IDBIT_SET(rclients, id));
 		adapter = mgmt_be_get_adapter_by_id(id);
 		if (adapter)
 			vty_out(vty, "    -- Adapter: %p\n", adapter);

mgmtd/mgmt_be_adapter.h

@@ -235,15 +235,23 @@ extern void mgmt_be_xpath_register_write(struct vty *vty);
  */
 extern int mgmt_be_send_native(enum mgmt_be_client_id id, void *msg);
 
+enum mgmt_be_xpath_subscr_type {
+	MGMT_BE_XPATH_SUBSCR_TYPE_CFG,
+	MGMT_BE_XPATH_SUBSCR_TYPE_OPER,
+	MGMT_BE_XPATH_SUBSCR_TYPE_NOTIF,
+	MGMT_BE_XPATH_SUBSCR_TYPE_RPC,
+};
+
 /**
  * Lookup the clients which are subscribed to a given `xpath`
  * and the way they are subscribed.
  *
  * Args:
  *     xpath - the xpath to check for subscription information.
- *     config - true for config interest false for oper interest.
+ *     type - type of subscription to check for.
  */
-extern uint64_t mgmt_be_interested_clients(const char *xpath, bool config);
+extern uint64_t mgmt_be_interested_clients(const char *xpath,
+					   enum mgmt_be_xpath_subscr_type type);
 
 /**
  * mgmt_fe_adapter_send_notify() - notify FE clients of a notification.

mgmtd/mgmt_fe_adapter.c

@@ -1101,6 +1101,47 @@ done:
 	return ret;
 }
 
+static int fe_adapter_send_rpc_reply(struct mgmt_fe_session_ctx *session,
+				     uint64_t req_id, uint8_t result_type,
+				     const struct lyd_node *result)
+{
+	struct mgmt_msg_rpc_reply *msg;
+	uint8_t **darrp = NULL;
+	int ret;
+
+	msg = mgmt_msg_native_alloc_msg(struct mgmt_msg_rpc_reply, 0,
+					MTYPE_MSG_NATIVE_RPC_REPLY);
+	msg->refer_id = session->session_id;
+	msg->req_id = req_id;
+	msg->code = MGMT_MSG_CODE_RPC_REPLY;
+	msg->result_type = result_type;
+
+	if (result) {
+		darrp = mgmt_msg_native_get_darrp(msg);
+		ret = yang_print_tree_append(darrp, result, result_type, 0);
+		if (ret != LY_SUCCESS) {
+			__log_err("Error building rpc-reply result for client %s session-id %" PRIu64
+				  " req-id %" PRIu64 " result type %u",
+				  session->adapter->name, session->session_id,
+				  req_id, result_type);
+			goto done;
+		}
+	}
+
+	__dbg("Sending rpc-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));
+
+	ret = fe_adapter_send_native_msg(session->adapter, msg,
+					 mgmt_msg_native_get_msg_len(msg),
+					 false);
+done:
+	mgmt_msg_native_free_msg(msg);
+
+	return ret;
+}
+
 static int fe_adapter_send_edit_reply(struct mgmt_fe_session_ctx *session,
 				      uint64_t req_id, const char *xpath)
 {
@@ -1215,7 +1256,8 @@ static void fe_adapter_handle_get_data(struct mgmt_fe_session_ctx *session,
 	}
 	darr_free(snodes);
 
-	clients = mgmt_be_interested_clients(msg->xpath, false);
+	clients = mgmt_be_interested_clients(msg->xpath,
+					     MGMT_BE_XPATH_SUBSCR_TYPE_OPER);
 	if (!clients && !CHECK_FLAG(msg->flags, GET_DATA_FLAG_CONFIG)) {
 		__dbg("No backends provide xpath: %s for txn-id: %" PRIu64
 		      " session-id: %" PRIu64,
@@ -1270,7 +1312,7 @@ static void fe_adapter_handle_edit(struct mgmt_fe_session_ctx *session,
 	}
 
 	xpath = mgmt_msg_native_xpath_data_decode(msg, msg_len, data);
-	if (!xpath || !data) {
+	if (!xpath) {
 		fe_adapter_send_error(session, msg->req_id, false, -EINVAL,
 				      "Invalid message");
 		return;
@@ -1359,6 +1401,96 @@ static void fe_adapter_handle_edit(struct mgmt_fe_session_ctx *session,
 	}
 }
 
+/**
+ * fe_adapter_handle_rpc() - Handle an RPC message from an FE client.
+ * @session: the client session.
+ * @msg_raw: the message data.
+ * @msg_len: the length of the message data.
+ */
+static void fe_adapter_handle_rpc(struct mgmt_fe_session_ctx *session,
+				  void *__msg, size_t msg_len)
+{
+	struct mgmt_msg_rpc *msg = __msg;
+	const struct lysc_node *snode;
+	const char *xpath, *data;
+	uint64_t req_id = msg->req_id;
+	uint64_t clients;
+	int ret;
+
+	__dbg("Received RPC request from client %s for session-id %" PRIu64
+	      " req-id %" PRIu64,
+	      session->adapter->name, session->session_id, msg->req_id);
+
+	xpath = mgmt_msg_native_xpath_data_decode(msg, msg_len, data);
+	if (!xpath) {
+		fe_adapter_send_error(session, req_id, false, -EINVAL,
+				      "Invalid message");
+		return;
+	}
+
+	if (session->txn_id != MGMTD_TXN_ID_NONE) {
+		fe_adapter_send_error(session, req_id, false, -EINPROGRESS,
+				      "Transaction in progress txn-id: %" PRIu64
+				      " for session-id: %" PRIu64,
+				      session->txn_id, session->session_id);
+		return;
+	}
+
+	snode = lys_find_path(ly_native_ctx, NULL, xpath, 0);
+	if (!snode) {
+		fe_adapter_send_error(session, req_id, false, -ENOENT,
+				      "No such path: %s", xpath);
+		return;
+	}
+
+	if (snode->nodetype == LYS_RPC)
+		clients =
+			mgmt_be_interested_clients(xpath,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_RPC);
+	else if (snode->nodetype == LYS_ACTION)
+		clients =
+			mgmt_be_interested_clients(xpath,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_CFG);
+	else {
+		fe_adapter_send_error(session, req_id, false, -EINVAL,
+				      "Not an RPC or action path: %s", xpath);
+		return;
+	}
+
+	if (!clients) {
+		__dbg("No backends implement xpath: %s for txn-id: %" PRIu64
+		      " session-id: %" PRIu64,
+		      xpath, session->txn_id, session->session_id);
+
+		fe_adapter_send_error(session, req_id, false, -ENOENT,
+				      "No backends implement xpath: %s", xpath);
+		return;
+	}
+
+	/* Start a RPC Transaction */
+	session->txn_id = mgmt_create_txn(session->session_id,
+					  MGMTD_TXN_TYPE_RPC);
+	if (session->txn_id == MGMTD_SESSION_ID_NONE) {
+		fe_adapter_send_error(session, req_id, false, -EINPROGRESS,
+				      "Failed to create an RPC transaction");
+		return;
+	}
+
+	__dbg("Created new rpc txn-id: %" PRIu64 " for session-id: %" PRIu64,
+	      session->txn_id, session->session_id);
+
+	/* Create an RPC request under the transaction */
+	ret = mgmt_txn_send_rpc(session->txn_id, req_id, clients,
+				msg->request_type, xpath, data,
+				mgmt_msg_native_data_len_decode(msg, msg_len));
+	if (ret) {
+		/* destroy the just created txn */
+		mgmt_destroy_txn(&session->txn_id);
+		fe_adapter_send_error(session, req_id, false, -EINPROGRESS,
+				      "Failed to create an RPC transaction");
+	}
+}
+
 /**
  * Handle a native encoded message from the FE client.
  */
@@ -1383,6 +1515,9 @@ static void fe_adapter_handle_native_msg(struct mgmt_fe_client_adapter *adapter,
 	case MGMT_MSG_CODE_EDIT:
 		fe_adapter_handle_edit(session, msg, msg_len);
 		break;
+	case MGMT_MSG_CODE_RPC:
+		fe_adapter_handle_rpc(session, msg, msg_len);
+		break;
 	default:
 		__log_err("unknown native message session-id %" PRIu64
 			  " req-id %" PRIu64 " code %u to FE adapter %s",
@@ -1622,6 +1757,24 @@ int mgmt_fe_adapter_send_tree_data(uint64_t session_id, uint64_t txn_id,
 	return ret;
 }
 
+int mgmt_fe_adapter_send_rpc_reply(uint64_t session_id, uint64_t txn_id,
+				   uint64_t req_id, LYD_FORMAT result_type,
+				   const struct lyd_node *result)
+{
+	struct mgmt_fe_session_ctx *session;
+	int ret;
+
+	session = mgmt_session_id2ctx(session_id);
+	if (!session || session->txn_id != txn_id)
+		return -1;
+
+	ret = fe_adapter_send_rpc_reply(session, req_id, result_type, result);
+
+	mgmt_destroy_txn(&session->txn_id);
+
+	return ret;
+}
+
 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,

mgmtd/mgmt_fe_adapter.h

@@ -162,6 +162,26 @@ mgmt_fe_adapter_send_tree_data(uint64_t session_id, uint64_t txn_id,
 			       uint32_t wd_options, const struct lyd_node *tree,
 			       int partial_error, bool short_circuit_ok);
 
+/**
+ * Send RPC reply back to client.
+ *
+ * This also cleans up and frees the transaction.
+ *
+ * Args:
+ *	session_id: the session.
+ *	txn_id: the txn_id this data pertains to
+ *	req_id: the req id for the rpc message
+ *	result_type: the format of the result data.
+ *	result: the results.
+ *
+ * Return:
+ *	the return value from the underlying send function.
+ */
+extern int mgmt_fe_adapter_send_rpc_reply(uint64_t session_id, uint64_t txn_id,
+					  uint64_t req_id,
+					  LYD_FORMAT result_type,
+					  const struct lyd_node *result);
+
 /**
  * Send edit reply back to client. If error is not 0, a native error is sent.
  *

mgmtd/mgmt_memory.c

@@ -20,6 +20,7 @@
 DEFINE_MGROUP(MGMTD, "mgmt");
 DEFINE_MTYPE(MGMTD, MGMTD, "instance");
 DEFINE_MTYPE(MGMTD, MGMTD_XPATH, "xpath regex");
+DEFINE_MTYPE(MGMTD, MGMTD_ERR, "error");
 DEFINE_MTYPE(MGMTD, MGMTD_BE_ADPATER, "backend adapter");
 DEFINE_MTYPE(MGMTD, MGMTD_FE_ADPATER, "frontend adapter");
 DEFINE_MTYPE(MGMTD, MGMTD_FE_SESSION, "frontend session");
@@ -30,5 +31,6 @@ DEFINE_MTYPE(MGMTD, MGMTD_TXN_COMMCFG_REQ, "txn commit-config requests");
 DEFINE_MTYPE(MGMTD, MGMTD_TXN_GETDATA_REQ, "txn get-data requests");
 DEFINE_MTYPE(MGMTD, MGMTD_TXN_GETDATA_REPLY, "txn get-data replies");
 DEFINE_MTYPE(MGMTD, MGMTD_TXN_GETTREE_REQ, "txn get-tree requests");
+DEFINE_MTYPE(MGMTD, MGMTD_TXN_RPC_REQ, "txn rpc requests");
 DEFINE_MTYPE(MGMTD, MGMTD_TXN_CFG_BATCH, "txn config batches");
 DEFINE_MTYPE(MGMTD, MGMTD_CMT_INFO, "commit info");

mgmtd/mgmt_memory.h

@@ -14,6 +14,7 @@
 DECLARE_MGROUP(MGMTD);
 DECLARE_MTYPE(MGMTD);
 DECLARE_MTYPE(MGMTD_XPATH);
+DECLARE_MTYPE(MGMTD_ERR);
 DECLARE_MTYPE(MGMTD_BE_ADPATER);
 DECLARE_MTYPE(MGMTD_FE_ADPATER);
 DECLARE_MTYPE(MGMTD_FE_SESSION);
@@ -24,6 +25,7 @@ DECLARE_MTYPE(MGMTD_TXN_COMMCFG_REQ);
 DECLARE_MTYPE(MGMTD_TXN_GETDATA_REQ);
 DECLARE_MTYPE(MGMTD_TXN_GETDATA_REPLY);
 DECLARE_MTYPE(MGMTD_TXN_GETTREE_REQ);
+DECLARE_MTYPE(MGMTD_TXN_RPC_REQ);
 DECLARE_MTYPE(MGMTD_TXN_CFG_BATCH);
 DECLARE_MTYPE(MGMTD_BE_ADAPTER_MSG_BUF);
 DECLARE_MTYPE(MGMTD_CMT_INFO);

mgmtd/mgmt_testc.c

@@ -18,6 +18,7 @@
 /* ---------------- */
 
 static void async_notification(struct nb_cb_notify_args *args);
+static int rpc_callback(struct nb_cb_rpc_args *args);
 
 static void sigusr1(void);
 static void sigint(void);
@@ -86,6 +87,10 @@ static const struct frr_yang_module_info frr_ripd_info = {
 			.xpath = "/frr-ripd:authentication-failure",
 			.cbs.notify = async_notification,
 		},
+		{
+			.xpath = "/frr-ripd:clear-rip-route",
+			.cbs.rpc = rpc_callback,
+		},
 		{
 			.xpath = NULL,
 		}
@@ -113,6 +118,7 @@ FRR_DAEMON_INFO(mgmtd_testc, MGMTD_TESTC,
 /* clang-format on */
 
 const char **__notif_xpaths;
+const char **__rpc_xpaths;
 
 struct mgmt_be_client_cbs __client_cbs = {};
 struct event *event_timeout;
@@ -134,6 +140,7 @@ static void quit(int exit_code)
 {
 	EVENT_OFF(event_timeout);
 	darr_free(__client_cbs.notif_xpaths);
+	darr_free(__client_cbs.rpc_xpaths);
 
 	frr_fini();
 
@@ -152,6 +159,12 @@ static void timeout(struct event *event)
 	quit(1);
 }
 
+static void success(struct event *event)
+{
+	zlog_notice("Success, exiting");
+	quit(0);
+}
+
 static void async_notification(struct nb_cb_notify_args *args)
 {
 	zlog_notice("Received YANG notification");
@@ -163,6 +176,23 @@ static void async_notification(struct nb_cb_notify_args *args)
 		quit(0);
 }
 
+static int rpc_callback(struct nb_cb_rpc_args *args)
+{
+	const char *vrf = NULL;
+
+	zlog_notice("Received YANG RPC");
+
+	if (yang_dnode_exists(args->input, "vrf"))
+		vrf = yang_dnode_get_string(args->input, "vrf");
+
+	printf("{\"frr-ripd:clear-rip-route\": {\"vrf\": \"%s\"}}\n", vrf);
+
+	event_cancel(&event_timeout);
+	event_add_timer(master, success, NULL, 1, NULL);
+
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	int f_listen = 0;
@@ -217,6 +247,10 @@ int main(int argc, char **argv)
 		__client_cbs.nnotif_xpaths = darr_len(__notif_xpaths);
 	}
 
+	darr_push(__rpc_xpaths, "/frr-ripd:clear-rip-route");
+	__client_cbs.rpc_xpaths = __rpc_xpaths;
+	__client_cbs.nrpc_xpaths = darr_len(__rpc_xpaths);
+
 	mgmt_be_client = mgmt_be_client_create("mgmtd-testc", &__client_cbs, 0,
 					       master);
 

mgmtd/mgmt_txn.c

@@ -29,6 +29,7 @@ enum mgmt_txn_event {
 	MGMTD_TXN_PROC_COMMITCFG,
 	MGMTD_TXN_PROC_GETCFG,
 	MGMTD_TXN_PROC_GETTREE,
+	MGMTD_TXN_PROC_RPC,
 	MGMTD_TXN_COMMITCFG_TIMEOUT,
 };
 
@@ -188,6 +189,15 @@ struct txn_req_get_tree {
 	struct lyd_node *client_results; /* result tree from clients */
 };
 
+struct txn_req_rpc {
+	char *xpath;	       /* xpath of rpc/action to invoke */
+	uint64_t sent_clients; /* Bitmask of clients sent req to */
+	uint64_t recv_clients; /* Bitmask of clients recv reply from */
+	uint8_t result_type;   /* LYD_FORMAT for results */
+	char *errstr;	       /* error string */
+	struct lyd_node *client_results; /* result tree from clients */
+};
+
 struct mgmt_txn_req {
 	struct mgmt_txn_ctx *txn;
 	enum mgmt_txn_event req_event;
@@ -196,6 +206,7 @@ struct mgmt_txn_req {
 		struct mgmt_set_cfg_req *set_cfg;
 		struct mgmt_get_data_req *get_data;
 		struct txn_req_get_tree *get_tree;
+		struct txn_req_rpc *rpc;
 		struct mgmt_commit_cfg_req commit_cfg;
 	} req;
 
@@ -221,6 +232,7 @@ struct mgmt_txn_ctx {
 	struct event *proc_get_tree;
 	struct event *comm_cfg_timeout;
 	struct event *get_tree_timeout;
+	struct event *rpc_timeout;
 	struct event *clnup;
 
 	/* List of backend adapters involved in this transaction */
@@ -252,6 +264,10 @@ struct mgmt_txn_ctx {
 	 * List of pending get-tree requests.
 	 */
 	struct mgmt_txn_reqs_head get_tree_reqs;
+	/*
+	 * List of pending rpc requests.
+	 */
+	struct mgmt_txn_reqs_head rpc_reqs;
 	/*
 	 * There will always be one commit-config allowed for a given
 	 * transaction/session. No need to maintain lists for it.
@@ -416,6 +432,15 @@ static struct mgmt_txn_req *mgmt_txn_req_alloc(struct mgmt_txn_ctx *txn,
 		      " session-id: %" PRIu64,
 		      txn_req->req_id, txn->txn_id, txn->session_id);
 		break;
+	case MGMTD_TXN_PROC_RPC:
+		txn_req->req.rpc = XCALLOC(MTYPE_MGMTD_TXN_RPC_REQ,
+					   sizeof(struct txn_req_rpc));
+		assert(txn_req->req.rpc);
+		mgmt_txn_reqs_add_tail(&txn->rpc_reqs, txn_req);
+		__dbg("Added a new RPC req-id: %" PRIu64 " txn-id: %" PRIu64
+		      " session-id: %" PRIu64,
+		      txn_req->req_id, txn->txn_id, txn->session_id);
+		break;
 	case MGMTD_TXN_COMMITCFG_TIMEOUT:
 		break;
 	}
@@ -506,6 +531,15 @@ static void mgmt_txn_req_free(struct mgmt_txn_req **txn_req)
 		XFREE(MTYPE_MGMTD_XPATH, (*txn_req)->req.get_tree->xpath);
 		XFREE(MTYPE_MGMTD_TXN_GETTREE_REQ, (*txn_req)->req.get_tree);
 		break;
+	case MGMTD_TXN_PROC_RPC:
+		__dbg("Deleting RPC req-id: %" PRIu64 " txn-id: %" PRIu64,
+		      (*txn_req)->req_id, (*txn_req)->txn->txn_id);
+		req_list = &(*txn_req)->txn->rpc_reqs;
+		lyd_free_all((*txn_req)->req.rpc->client_results);
+		XFREE(MTYPE_MGMTD_ERR, (*txn_req)->req.rpc->errstr);
+		XFREE(MTYPE_MGMTD_XPATH, (*txn_req)->req.rpc->xpath);
+		XFREE(MTYPE_MGMTD_TXN_RPC_REQ, (*txn_req)->req.rpc);
+		break;
 	case MGMTD_TXN_COMMITCFG_TIMEOUT:
 		break;
 	}
@@ -880,7 +914,9 @@ static int mgmt_txn_create_config_batches(struct mgmt_txn_req *txn_req,
 
 		__dbg("XPATH: %s, Value: '%s'", xpath, value ? value : "NIL");
 
-		clients = mgmt_be_interested_clients(xpath, true);
+		clients =
+			mgmt_be_interested_clients(xpath,
+						   MGMT_BE_XPATH_SUBSCR_TYPE_CFG);
 
 		chg_clients = 0;
 
@@ -1306,6 +1342,33 @@ static int txn_get_tree_data_done(struct mgmt_txn_ctx *txn,
 	return ret;
 }
 
+static int txn_rpc_done(struct mgmt_txn_ctx *txn, struct mgmt_txn_req *txn_req)
+{
+	struct txn_req_rpc *rpc = txn_req->req.rpc;
+	uint64_t req_id = txn_req->req_id;
+
+	/* cancel timer and send reply onward */
+	EVENT_OFF(txn->rpc_timeout);
+
+	if (rpc->errstr)
+		mgmt_fe_adapter_txn_error(txn->txn_id, req_id, false, -1,
+					  rpc->errstr);
+	else if (mgmt_fe_adapter_send_rpc_reply(txn->session_id, txn->txn_id,
+						req_id, rpc->result_type,
+						rpc->client_results)) {
+		__log_err("Error sending the results of RPC for txn-id %" PRIu64
+			  " req_id %" PRIu64 " to requested type %u",
+			  txn->txn_id, req_id, rpc->result_type);
+
+		(void)mgmt_fe_adapter_txn_error(txn->txn_id, req_id, false, -1,
+						"Error converting results of RPC");
+	}
+
+	/* we're done with the request */
+	mgmt_txn_req_free(&txn_req);
+
+	return 0;
+}
 
 static void txn_get_tree_timeout(struct event *thread)
 {
@@ -1333,6 +1396,31 @@ static void txn_get_tree_timeout(struct event *thread)
 	txn_get_tree_data_done(txn, txn_req);
 }
 
+static void txn_rpc_timeout(struct event *thread)
+{
+	struct mgmt_txn_ctx *txn;
+	struct mgmt_txn_req *txn_req;
+
+	txn_req = (struct mgmt_txn_req *)EVENT_ARG(thread);
+	txn = txn_req->txn;
+
+	assert(txn);
+	assert(txn->type == MGMTD_TXN_TYPE_RPC);
+
+	__log_err("Backend timeout txn-id: %" PRIu64 " ending rpc", txn->txn_id);
+
+	/*
+	 * Send a get-tree data reply.
+	 *
+	 * NOTE: The transaction cleanup will be triggered from Front-end
+	 * adapter.
+	 */
+
+	txn_req->req.rpc->errstr =
+		XSTRDUP(MTYPE_MGMTD_ERR, "Operation on the backend timed-out");
+	txn_rpc_done(txn, txn_req);
+}
+
 /*
  * Send CFG_APPLY_REQs to all the backend client.
  *
@@ -1516,6 +1604,7 @@ static void mgmt_txn_send_getcfg_reply_data(struct mgmt_txn_req *txn_req,
 	case MGMTD_TXN_PROC_SETCFG:
 	case MGMTD_TXN_PROC_COMMITCFG:
 	case MGMTD_TXN_PROC_GETTREE:
+	case MGMTD_TXN_PROC_RPC:
 	case MGMTD_TXN_COMMITCFG_TIMEOUT:
 		__log_err("Invalid Txn-Req-Event %u", txn_req->req_event);
 		break;
@@ -1721,6 +1810,7 @@ static struct mgmt_txn_ctx *mgmt_txn_create_new(uint64_t session_id,
 		mgmt_txn_reqs_init(&txn->set_cfg_reqs);
 		mgmt_txn_reqs_init(&txn->get_cfg_reqs);
 		mgmt_txn_reqs_init(&txn->get_tree_reqs);
+		mgmt_txn_reqs_init(&txn->rpc_reqs);
 		txn->commit_cfg_req = NULL;
 		txn->refcount = 0;
 		if (!mgmt_txn_mm->next_txn_id)
@@ -1890,6 +1980,7 @@ static void mgmt_txn_register_event(struct mgmt_txn_ctx *txn,
 				&txn->comm_cfg_timeout);
 		break;
 	case MGMTD_TXN_PROC_GETTREE:
+	case MGMTD_TXN_PROC_RPC:
 		assert(!"code bug do not register this event");
 		break;
 	}
@@ -2496,6 +2587,64 @@ reply:
 	return 0;
 }
 
+int mgmt_txn_send_rpc(uint64_t txn_id, uint64_t req_id, uint64_t clients,
+		      LYD_FORMAT result_type, const char *xpath,
+		      const char *data, size_t data_len)
+{
+	struct mgmt_txn_ctx *txn;
+	struct mgmt_txn_req *txn_req;
+	struct mgmt_msg_rpc *msg;
+	struct txn_req_rpc *rpc;
+	uint64_t id;
+	int ret;
+
+	txn = mgmt_txn_id2ctx(txn_id);
+	if (!txn)
+		return -1;
+
+	txn_req = mgmt_txn_req_alloc(txn, req_id, MGMTD_TXN_PROC_RPC);
+	rpc = txn_req->req.rpc;
+	rpc->xpath = XSTRDUP(MTYPE_MGMTD_XPATH, xpath);
+	rpc->result_type = result_type;
+
+	msg = mgmt_msg_native_alloc_msg(struct mgmt_msg_rpc, 0,
+					MTYPE_MSG_NATIVE_RPC);
+	msg->refer_id = txn_id;
+	msg->req_id = req_id;
+	msg->code = MGMT_MSG_CODE_RPC;
+	msg->request_type = result_type;
+
+	mgmt_msg_native_xpath_encode(msg, xpath);
+	if (data)
+		mgmt_msg_native_append(msg, data, data_len);
+
+	assert(clients);
+	FOREACH_BE_CLIENT_BITS (id, clients) {
+		ret = mgmt_be_send_native(id, msg);
+		if (ret) {
+			__log_err("Could not send rpc message to backend client %s",
+				  mgmt_be_client_id2name(id));
+			continue;
+		}
+
+		__dbg("Sent rpc req to backend client %s",
+		      mgmt_be_client_id2name(id));
+
+		/* record that we sent the request to the client */
+		rpc->sent_clients |= (1u << id);
+	}
+
+	mgmt_msg_native_free_msg(msg);
+
+	if (!rpc->sent_clients)
+		return txn_rpc_done(txn, txn_req);
+
+	event_add_timer(mgmt_txn_tm, txn_rpc_timeout, txn_req,
+			MGMTD_TXN_RPC_MAX_DELAY_SEC, &txn->rpc_timeout);
+
+	return 0;
+}
+
 /*
  * Error reply from the backend client.
  */
@@ -2506,6 +2655,7 @@ int mgmt_txn_notify_error(struct mgmt_be_client_adapter *adapter,
 	enum mgmt_be_client_id id = adapter->id;
 	struct mgmt_txn_ctx *txn = mgmt_txn_id2ctx(txn_id);
 	struct txn_req_get_tree *get_tree;
+	struct txn_req_rpc *rpc;
 	struct mgmt_txn_req *txn_req;
 
 	if (!txn) {
@@ -2518,6 +2668,10 @@ int mgmt_txn_notify_error(struct mgmt_be_client_adapter *adapter,
 	FOREACH_TXN_REQ_IN_LIST (&txn->get_tree_reqs, txn_req)
 		if (txn_req->req_id == req_id)
 			break;
+	if (!txn_req)
+		FOREACH_TXN_REQ_IN_LIST (&txn->rpc_reqs, txn_req)
+			if (txn_req->req_id == req_id)
+				break;
 	if (!txn_req) {
 		__log_err("Error reply from %s for txn-id %" PRIu64
 			  " cannot find req_id %" PRIu64,
@@ -2538,6 +2692,15 @@ int mgmt_txn_notify_error(struct mgmt_be_client_adapter *adapter,
 		if (get_tree->recv_clients != get_tree->sent_clients)
 			return 0;
 		return txn_get_tree_data_done(txn, txn_req);
+	case MGMTD_TXN_PROC_RPC:
+		rpc = txn_req->req.rpc;
+		rpc->recv_clients |= (1u << id);
+		rpc->errstr = XSTRDUP(MTYPE_MGMTD_ERR, errstr);
+
+		/* check if done yet */
+		if (rpc->recv_clients != rpc->sent_clients)
+			return 0;
+		return txn_rpc_done(txn, txn_req);
 
 	/* non-native message events */
 	case MGMTD_TXN_PROC_SETCFG:
@@ -2625,6 +2788,64 @@ int mgmt_txn_notify_tree_data_reply(struct mgmt_be_client_adapter *adapter,
 	return txn_get_tree_data_done(txn, txn_req);
 }
 
+int mgmt_txn_notify_rpc_reply(struct mgmt_be_client_adapter *adapter,
+			      struct mgmt_msg_rpc_reply *reply_msg,
+			      size_t msg_len)
+{
+	uint64_t txn_id = reply_msg->refer_id;
+	uint64_t req_id = reply_msg->req_id;
+	enum mgmt_be_client_id id = adapter->id;
+	struct mgmt_txn_ctx *txn = mgmt_txn_id2ctx(txn_id);
+	struct mgmt_txn_req *txn_req;
+	struct txn_req_rpc *rpc;
+	size_t data_len = msg_len - sizeof(*reply_msg);
+	LY_ERR err;
+
+	if (!txn) {
+		__log_err("RPC reply from %s for a missing txn-id %" PRIu64,
+			  adapter->name, txn_id);
+		return -1;
+	}
+
+	/* Find the request. */
+	FOREACH_TXN_REQ_IN_LIST (&txn->rpc_reqs, txn_req)
+		if (txn_req->req_id == req_id)
+			break;
+	if (!txn_req) {
+		__log_err("RPC reply from %s for txn-id %" PRIu64
+			  " missing req_id %" PRIu64,
+			  adapter->name, txn_id, req_id);
+		return -1;
+	}
+
+	rpc = txn_req->req.rpc;
+
+	/* we don't expect more than one daemon to provide output for an RPC */
+	if (!rpc->client_results && data_len > 0) {
+		err = yang_parse_rpc(rpc->xpath, reply_msg->result_type,
+				     reply_msg->data, true,
+				     &rpc->client_results);
+		if (err) {
+			__log_err("RPC reply from %s for txn-id %" PRIu64
+				  " req_id %" PRIu64
+				  " error parsing result of type %u",
+				  adapter->name, txn_id, req_id,
+				  reply_msg->result_type);
+			rpc->errstr =
+				XSTRDUP(MTYPE_MGMTD_ERR,
+					"Cannot parse result from the backend");
+		}
+	}
+
+	rpc->recv_clients |= (1u << id);
+
+	/* check if done yet */
+	if (rpc->recv_clients != rpc->sent_clients)
+		return 0;
+
+	return txn_rpc_done(txn, txn_req);
+}
+
 void mgmt_txn_status_write(struct vty *vty)
 {
 	struct mgmt_txn_ctx *txn;

mgmtd/mgmt_txn.h

@@ -21,6 +21,7 @@
 
 #define MGMTD_TXN_CFG_COMMIT_MAX_DELAY_SEC 600
 #define MGMTD_TXN_GET_TREE_MAX_DELAY_SEC   600
+#define MGMTD_TXN_RPC_MAX_DELAY_SEC	   60
 
 #define MGMTD_TXN_CLEANUP_DELAY_USEC 10
 
@@ -48,7 +49,8 @@ struct mgmt_edit_req;
 enum mgmt_txn_type {
 	MGMTD_TXN_TYPE_NONE = 0,
 	MGMTD_TXN_TYPE_CONFIG,
-	MGMTD_TXN_TYPE_SHOW
+	MGMTD_TXN_TYPE_SHOW,
+	MGMTD_TXN_TYPE_RPC,
 };
 
 static inline const char *mgmt_txn_type2str(enum mgmt_txn_type type)
@@ -60,6 +62,8 @@ static inline const char *mgmt_txn_type2str(enum mgmt_txn_type type)
 		return "CONFIG";
 	case MGMTD_TXN_TYPE_SHOW:
 		return "SHOW";
+	case MGMTD_TXN_TYPE_RPC:
+		return "RPC";
 	}
 
 	return "Unknown";
@@ -246,6 +250,25 @@ mgmt_txn_send_edit(uint64_t txn_id, uint64_t req_id, Mgmtd__DatastoreId ds_id,
 		   LYD_FORMAT request_type, uint8_t flags, uint8_t operation,
 		   const char *xpath, const char *data);
 
+/**
+ * Send RPC request.
+ *
+ * Args:
+ *	txn_id: Transaction identifier.
+ *	req_id: FE client request identifier.
+ *	clients: Bitmask of clients to send RPC to.
+ *	result_type: LYD_FORMAT result format.
+ *	xpath: The xpath of the RPC.
+ *	data: The input parameters data tree.
+ *	data_len: The length of the input parameters data.
+ *
+ * Return:
+ *	0 on success.
+ */
+extern int mgmt_txn_send_rpc(uint64_t txn_id, uint64_t req_id, uint64_t clients,
+			     LYD_FORMAT result_type, const char *xpath,
+			     const char *data, size_t data_len);
+
 /*
  * Notifiy backend adapter on connection.
  */
@@ -312,6 +335,18 @@ extern int mgmt_txn_notify_tree_data_reply(struct mgmt_be_client_adapter *adapte
 					   struct mgmt_msg_tree_data *data_msg,
 					   size_t msg_len);
 
+/**
+ * Process a reply from a backend client to our RPC request
+ *
+ * Args:
+ *	adapter: The adapter that received the result.
+ *	reply_msg: The message from the backend.
+ *	msg_len: Total length of the message.
+ */
+extern int mgmt_txn_notify_rpc_reply(struct mgmt_be_client_adapter *adapter,
+				     struct mgmt_msg_rpc_reply *reply_msg,
+				     size_t msg_len);
+
 /*
  * Dump transaction status to vty.
  */

mgmtd/mgmt_vty.c

@@ -296,6 +296,21 @@ DEFPY(mgmt_edit, mgmt_edit_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFPY(mgmt_rpc, mgmt_rpc_cmd,
+      "mgmt rpc XPATH [json|xml]$fmt [DATA]",
+      MGMTD_STR
+      "Invoke RPC\n"
+      "XPath expression specifying the YANG data path\n"
+      "JSON input format (default)\n"
+      "XML input format\n"
+      "Input data tree\n")
+{
+	LYD_FORMAT format = (fmt && fmt[0] == 'x') ? LYD_XML : LYD_JSON;
+
+	vty_mgmt_send_rpc_req(vty, format, xpath, data);
+	return CMD_SUCCESS;
+}
+
 DEFPY(show_mgmt_get_config, show_mgmt_get_config_cmd,
       "show mgmt get-config [candidate|operational|running]$dsname WORD$path",
       SHOW_STR MGMTD_STR
@@ -702,6 +717,7 @@ void mgmt_vty_init(void)
 	install_element(CONFIG_NODE, &mgmt_remove_config_data_cmd);
 	install_element(CONFIG_NODE, &mgmt_replace_config_data_cmd);
 	install_element(CONFIG_NODE, &mgmt_edit_cmd);
+	install_element(CONFIG_NODE, &mgmt_rpc_cmd);
 	install_element(CONFIG_NODE, &mgmt_load_config_cmd);
 	install_element(CONFIG_NODE, &mgmt_save_config_cmd);
 	install_element(CONFIG_NODE, &mgmt_rollback_cmd);

ripd/rip_cli.c

@@ -1233,6 +1233,23 @@ DEFPY_YANG(no_rip_distribute_list_prefix,
 	return nb_cli_apply_changes(vty, NULL);
 }
 
+/*
+ * XPath: /frr-ripd:clear-rip-route
+ */
+DEFPY_YANG (clear_ip_rip,
+       clear_ip_rip_cmd,
+       "clear ip rip [vrf WORD]",
+       CLEAR_STR
+       IP_STR
+       "Clear IP RIP database\n"
+       VRF_CMD_HELP_STR)
+{
+	if (vrf)
+		nb_cli_rpc_enqueue(vty, "vrf", vrf);
+
+	return nb_cli_rpc(vty, "/frr-ripd:clear-rip-route", NULL);
+}
+
 /* RIP node structure. */
 static struct cmd_node rip_node = {
 	.name = "rip",
@@ -1295,6 +1312,8 @@ void rip_cli_init(void)
 	install_element(INTERFACE_NODE, &ip_rip_bfd_profile_cmd);
 	install_element(INTERFACE_NODE, &no_ip_rip_bfd_profile_cmd);
 
+	install_element(ENABLE_NODE, &clear_ip_rip_cmd);
+
 	if_rmap_init(RIP_NODE);
 }
 /* clang-format off */

ripd/rip_nb_rpcs.c

@@ -68,12 +68,11 @@ static void clear_rip_route(struct rip *rip)
 int clear_rip_route_rpc(struct nb_cb_rpc_args *args)
 {
 	struct rip *rip;
-	struct yang_data *yang_vrf;
 
-	yang_vrf = yang_data_list_find(args->input, "%s/%s", args->xpath,
+	if (args->input && yang_dnode_exists(args->input, "vrf")) {
-				       "input/vrf");
+		const char *name = yang_dnode_get_string(args->input, "vrf");
-	if (yang_vrf) {
+
-		rip = rip_lookup_by_vrf_name(yang_vrf->value);
+		rip = rip_lookup_by_vrf_name(name);
 		if (rip)
 			clear_rip_route(rip);
 	} else {

ripd/ripd.c

@@ -3254,38 +3254,6 @@ DEFUN (show_ip_rip_status,
 	return CMD_SUCCESS;
 }
 
-#include "ripd/ripd_clippy.c"
-
-/*
- * XPath: /frr-ripd:clear-rip-route
- */
-DEFPY_YANG (clear_ip_rip,
-       clear_ip_rip_cmd,
-       "clear ip rip [vrf WORD]",
-       CLEAR_STR
-       IP_STR
-       "Clear IP RIP database\n"
-       VRF_CMD_HELP_STR)
-{
-	struct list *input;
-	int ret;
-
-	input = list_new();
-	if (vrf) {
-		struct yang_data *yang_vrf;
-
-		yang_vrf = yang_data_new("/frr-ripd:clear-rip-route/input/vrf",
-					 vrf);
-		listnode_add(input, yang_vrf);
-	}
-
-	ret = nb_cli_rpc(vty, "/frr-ripd:clear-rip-route", input, NULL);
-
-	list_delete(&input);
-
-	return ret;
-}
-
 /* Distribute-list update functions. */
 static void rip_distribute_update(struct distribute_ctx *ctx,
 				  struct distribute *dist)
@@ -3660,7 +3628,6 @@ void rip_init(void)
 	/* Install rip commands. */
 	install_element(VIEW_NODE, &show_ip_rip_cmd);
 	install_element(VIEW_NODE, &show_ip_rip_status_cmd);
-	install_element(ENABLE_NODE, &clear_ip_rip_cmd);
 
 	/* Debug related init. */
 	rip_debug_init();

ripd/subdir.am

@@ -33,7 +33,6 @@ ripd_ripd_SOURCES = \
 clippy_scan += \
 	ripd/rip_bfd.c \
 	ripd/rip_cli.c \
-	ripd/ripd.c \
 	# end
 
 noinst_HEADERS += \

ripngd/ripng_cli.c

@@ -624,6 +624,23 @@ DEFPY_YANG(no_ripng_ipv6_distribute_list_prefix,
 	return nb_cli_apply_changes(vty, NULL);
 }
 
+/*
+ * XPath: /frr-ripngd:clear-ripng-route
+ */
+DEFPY_YANG (clear_ipv6_rip,
+       clear_ipv6_rip_cmd,
+       "clear ipv6 ripng [vrf WORD]",
+       CLEAR_STR
+       IPV6_STR
+       "Clear IPv6 RIP database\n"
+       VRF_CMD_HELP_STR)
+{
+	if (vrf)
+		nb_cli_rpc_enqueue(vty, "vrf", vrf);
+
+	return nb_cli_rpc(vty, "/frr-ripngd:clear-ripng-route", NULL);
+}
+
 /* RIPng node structure. */
 static struct cmd_node cmd_ripng_node = {
 	.name = "ripng",
@@ -663,6 +680,8 @@ void ripng_cli_init(void)
 
 	install_element(INTERFACE_NODE, &ipv6_ripng_split_horizon_cmd);
 
+	install_element(ENABLE_NODE, &clear_ipv6_rip_cmd);
+
 	if_rmap_init(RIPNG_NODE);
 }
 

ripngd/ripng_nb_rpcs.c

@@ -70,12 +70,11 @@ static void clear_ripng_route(struct ripng *ripng)
 int clear_ripng_route_rpc(struct nb_cb_rpc_args *args)
 {
 	struct ripng *ripng;
-	struct yang_data *yang_vrf;
 
-	yang_vrf = yang_data_list_find(args->input, "%s/%s", args->xpath,
+	if (args->input && yang_dnode_exists(args->input, "vrf")) {
-				       "input/vrf");
+		const char *name = yang_dnode_get_string(args->input, "vrf");
-	if (yang_vrf) {
+
-		ripng = ripng_lookup_by_vrf_name(yang_vrf->value);
+		ripng = ripng_lookup_by_vrf_name(name);
 		if (ripng)
 			clear_ripng_route(ripng);
 	} else {

ripngd/ripngd.c

@@ -2231,38 +2231,6 @@ DEFUN (show_ipv6_ripng_status,
 	return CMD_SUCCESS;
 }
 
-#include "ripngd/ripngd_clippy.c"
-
-/*
- * XPath: /frr-ripngd:clear-ripng-route
- */
-DEFPY_YANG (clear_ipv6_rip,
-       clear_ipv6_rip_cmd,
-       "clear ipv6 ripng [vrf WORD]",
-       CLEAR_STR
-       IPV6_STR
-       "Clear IPv6 RIP database\n"
-       VRF_CMD_HELP_STR)
-{
-	struct list *input;
-	int ret;
-
-	input = list_new();
-	if (vrf) {
-		struct yang_data *yang_vrf;
-
-		yang_vrf = yang_data_new(
-			"/frr-ripngd:clear-ripng-route/input/vrf", vrf);
-		listnode_add(input, yang_vrf);
-	}
-
-	ret = nb_cli_rpc(vty, "/frr-ripngd:clear-ripng-route", input, NULL);
-
-	list_delete(&input);
-
-	return ret;
-}
-
 /* Update ECMP routes to zebra when ECMP is disabled. */
 void ripng_ecmp_disable(struct ripng *ripng)
 {
@@ -2680,7 +2648,6 @@ void ripng_init(void)
 	/* Install ripng commands. */
 	install_element(VIEW_NODE, &show_ipv6_ripng_cmd);
 	install_element(VIEW_NODE, &show_ipv6_ripng_status_cmd);
-	install_element(ENABLE_NODE, &clear_ipv6_rip_cmd);
 
 	ripng_if_init();
 	ripng_debug_init();

ripngd/subdir.am

@@ -27,7 +27,6 @@ ripngd_ripngd_SOURCES = \
 
 clippy_scan += \
 	ripngd/ripng_cli.c \
-	ripngd/ripngd.c \
 	# end
 
 noinst_HEADERS += \

tests/lib/northbound/test_oper_data.c

@@ -14,6 +14,7 @@
 #include "lib_vty.h"
 #include "log.h"
 #include "northbound.h"
+#include "northbound_cli.h"
 
 static struct event_loop *master;
 
@@ -200,6 +201,19 @@ static struct yang_data *frr_test_module_vrfs_vrf_routes_route_active_get_elem(
 	return NULL;
 }
 
+/*
+ * XPath: /frr-test-module:frr-test-module/vrfs/vrf/ping
+ */
+static int frr_test_module_vrfs_vrf_ping(struct nb_cb_rpc_args *args)
+{
+	const char *vrf = yang_dnode_get_string(args->input, "../name");
+	const char *data = yang_dnode_get_string(args->input, "data");
+
+	yang_dnode_rpc_output_add(args->output, "vrf", vrf);
+	yang_dnode_rpc_output_add(args->output, "data-out", data);
+
+	return NB_OK;
+}
 
 /*
  * XPath: /frr-test-module:frr-test-module/c1value
@@ -262,6 +276,10 @@ const struct frr_yang_module_info frr_test_module_info = {
 			.xpath = "/frr-test-module:frr-test-module/vrfs/vrf/routes/route/active",
 			.cbs.get_elem = frr_test_module_vrfs_vrf_routes_route_active_get_elem,
 		},
+		{
+			.xpath = "/frr-test-module:frr-test-module/vrfs/vrf/ping",
+			.cbs.rpc = frr_test_module_vrfs_vrf_ping,
+		},
 		{
 			.xpath = "/frr-test-module:frr-test-module/c1value",
 			.cbs.get_elem = frr_test_module_c1value_get_elem,
@@ -277,6 +295,33 @@ const struct frr_yang_module_info frr_test_module_info = {
 };
 /* clang-format on */
 
+DEFUN(test_rpc, test_rpc_cmd, "test rpc",
+      "Test\n"
+      "RPC\n")
+{
+	struct lyd_node *output = NULL;
+	char xpath[XPATH_MAXLEN];
+	int ret;
+
+	snprintf(xpath, sizeof(xpath),
+		 "/frr-test-module:frr-test-module/vrfs/vrf[name='testname']/ping");
+
+	nb_cli_rpc_enqueue(vty, "data", "testdata");
+
+	ret = nb_cli_rpc(vty, xpath, &output);
+	if (ret != CMD_SUCCESS) {
+		vty_out(vty, "RPC failed\n");
+		return ret;
+	}
+
+	vty_out(vty, "vrf %s data %s\n", yang_dnode_get_string(output, "vrf"),
+		yang_dnode_get_string(output, "data-out"));
+
+	yang_dnode_free(output);
+
+	return CMD_SUCCESS;
+}
+
 static const struct frr_yang_module_info *const modules[] = {
 	&frr_test_module_info,
 };
@@ -416,6 +461,8 @@ int main(int argc, char **argv)
 	lib_cmd_init();
 	nb_init(master, modules, array_size(modules), false);
 
+	install_element(ENABLE_NODE, &test_rpc_cmd);
+
 	/* Create artificial data. */
 	create_data(num_vrfs, num_interfaces, num_routes);
 

tests/lib/northbound/test_oper_data.in

@@ -1 +1,2 @@
 show yang operational-data /frr-test-module:frr-test-module
+test rpc

tests/lib/northbound/test_oper_data.refout

@@ -119,5 +119,7 @@ test# show yang operational-data /frr-test-module:frr-test-module
     }
   }
 }
+test# test rpc
+vrf testname data testdata
 test# 
 end.

tests/topotests/mgmt_rpc/test_rpc.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 eval: (blacken-mode 1) -*-
+# SPDX-License-Identifier: ISC
+#
+# March 21 2024, Igor Ryzhov <iryzhov@nfware.com>
+#
+# Copyright (c) 2024, NFWare Inc.
+#
+
+"""
+Test YANG Notifications
+"""
+import json
+import os
+import threading
+
+import pytest
+from lib.topogen import Topogen
+from lib.topotest import json_cmp
+
+pytestmark = [pytest.mark.ripd, pytest.mark.mgmtd]
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+
+
+@pytest.fixture(scope="module")
+def tgen(request):
+    "Setup/Teardown the environment and provide tgen argument to tests"
+
+    topodef = {"s1": ("r1",)}
+
+    tgen = Topogen(topodef, request.module.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+    for rname, router in router_list.items():
+        router.load_frr_config("frr.conf")
+
+    tgen.start_router()
+    yield tgen
+    tgen.stop_topology()
+
+
+def test_backend_rpc(tgen):
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"]
+
+    be_client_path = "/usr/lib/frr/mgmtd_testc"
+    rc, _, _ = r1.net.cmd_status(be_client_path + " --help")
+
+    if rc:
+        pytest.skip("No mgmtd_testc")
+
+    out = []
+
+    def run_testc():
+        output = r1.net.cmd_raises(
+            be_client_path + " --timeout 10 --log file:mgmt_testc.log"
+        )
+        out.append(json.loads(output))
+
+    t = threading.Thread(target=run_testc)
+    t.start()
+
+    r1.vtysh_cmd("clear ip rip vrf testname")
+
+    t.join()
+
+    jsout = out[0]
+
+    expected = {"frr-ripd:clear-rip-route": {"vrf": "testname"}}
+    result = json_cmp(jsout, expected)
+    assert result is None

yang/frr-test-module.yang

@@ -80,6 +80,23 @@ module frr-test-module {
             }
           }
         }
+        action ping {
+          input {
+            leaf data {
+              type string;
+            }
+          }
+          output {
+            leaf vrf {
+              type string;
+            }
+            // can't use the same name in input and output
+            // because of a bug in libyang < 2.1.148
+            leaf data-out {
+              type string;
+            }
+          }
+        }
       }
     }
     choice achoice {

zebra/zebra_nb_rpcs.c

@@ -20,48 +20,30 @@ int clear_evpn_dup_addr_rpc(struct nb_cb_rpc_args *args)
 {
 	struct zebra_vrf *zvrf;
 	int ret = NB_OK;
-	struct yang_data *yang_dup_choice = NULL, *yang_dup_vni = NULL,
-			 *yang_dup_ip = NULL, *yang_dup_mac = NULL;
-
-	yang_dup_choice = yang_data_list_find(args->input, "%s/%s", args->xpath,
-					      "input/clear-dup-choice");
 
 	zvrf = zebra_vrf_get_evpn();
 
-	if (yang_dup_choice
+	if (yang_dnode_exists(args->input, "all-vnis")) {
-	    && strcmp(yang_dup_choice->value, "all-case") == 0) {
 		zebra_vxlan_clear_dup_detect_vni_all(zvrf);
 	} else {
-		vni_t vni;
+		vni_t vni = yang_dnode_get_uint32(args->input, "vni-id");
 		struct ipaddr host_ip = {.ipa_type = IPADDR_NONE};
 		struct ethaddr mac;
 
-		yang_dup_vni = yang_data_list_find(
+		if (yang_dnode_exists(args->input, "mac-addr")) {
-			args->input, "%s/%s", args->xpath,
+			yang_dnode_get_mac(&mac, args->input, "mac-addr");
-			"input/clear-dup-choice/single-case/vni-id");
+			ret = zebra_vxlan_clear_dup_detect_vni_mac(zvrf, vni,
-		if (yang_dup_vni) {
+								   &mac,
-			vni = yang_str2uint32(yang_dup_vni->value);
+								   args->errmsg,
-
+								   args->errmsg_len);
-			yang_dup_mac = yang_data_list_find(
+		} else if (yang_dnode_exists(args->input, "vni-ipaddr")) {
-				args->input, "%s/%s", args->xpath,
+			yang_dnode_get_ip(&host_ip, args->input, "vni-ipaddr");
-				"input/clear-dup-choice/single-case/vni-id/mac-addr");
+			ret = zebra_vxlan_clear_dup_detect_vni_ip(zvrf, vni,
-			yang_dup_ip = yang_data_list_find(
+								  &host_ip,
-				args->input, "%s/%s", args->xpath,
+								  args->errmsg,
-				"input/clear-dup-choice/single-case/vni-id/vni-ipaddr");
+								  args->errmsg_len);
-
+		} else {
-			if (yang_dup_mac) {
+			ret = zebra_vxlan_clear_dup_detect_vni(zvrf, vni);
-				yang_str2mac(yang_dup_mac->value, &mac);
-				ret = zebra_vxlan_clear_dup_detect_vni_mac(
-					zvrf, vni, &mac, args->errmsg,
-					args->errmsg_len);
-			} else if (yang_dup_ip) {
-				yang_str2ip(yang_dup_ip->value, &host_ip);
-				ret = zebra_vxlan_clear_dup_detect_vni_ip(
-					zvrf, vni, &host_ip, args->errmsg,
-					args->errmsg_len);
-			} else
-				ret = zebra_vxlan_clear_dup_detect_vni(zvrf,
-								       vni);
 		}
 	}
 	if (ret < 0)

zebra/zebra_vty.c

@@ -3553,56 +3553,17 @@ DEFPY (clear_evpn_dup_addr,
        "IPv4 address\n"
        "IPv6 address\n")
 {
-	struct ipaddr host_ip = {.ipa_type = IPADDR_NONE };
-	int ret = CMD_SUCCESS;
-	struct list *input;
-	struct yang_data *yang_dup = NULL, *yang_dup_ip = NULL,
-			 *yang_dup_mac = NULL;
-
-	input = list_new();
-
 	if (!vni_str) {
-		yang_dup = yang_data_new(
+		nb_cli_rpc_enqueue(vty, "all-vnis", NULL);
-			"/frr-zebra:clear-evpn-dup-addr/input/clear-dup-choice",
-			"all-case");
 	} else {
-		yang_dup = yang_data_new_uint32(
+		nb_cli_rpc_enqueue(vty, "vni-id", vni_str);
-			"/frr-zebra:clear-evpn-dup-addr/input/clear-dup-choice/single-case/vni-id",
+		if (mac_str)
-			vni);
+			nb_cli_rpc_enqueue(vty, "mac-addr", mac_str);
-		if (!is_zero_mac(&mac->eth_addr)) {
+		else if (ip_str)
-			yang_dup_mac = yang_data_new_mac(
+			nb_cli_rpc_enqueue(vty, "vni-ipaddr", ip_str);
-				"/frr-zebra:clear-evpn-dup-addr/input/clear-dup-choice/single-case/vni-id/mac-addr",
-				&mac->eth_addr);
-			if (yang_dup_mac)
-				listnode_add(input, yang_dup_mac);
-		} else if (ip) {
-			if (sockunion_family(ip) == AF_INET) {
-				host_ip.ipa_type = IPADDR_V4;
-				host_ip.ipaddr_v4.s_addr = sockunion2ip(ip);
-			} else {
-				host_ip.ipa_type = IPADDR_V6;
-				memcpy(&host_ip.ipaddr_v6, &ip->sin6.sin6_addr,
-				       sizeof(struct in6_addr));
-			}
-
-			yang_dup_ip = yang_data_new_ip(
-				"/frr-zebra:clear-evpn-dup-addr/input/clear-dup-choice/single-case/vni-id/vni-ipaddr",
-				&host_ip);
-
-			if (yang_dup_ip)
-				listnode_add(input, yang_dup_ip);
-		}
 	}
 
-	if (yang_dup) {
+	return nb_cli_rpc(vty, "/frr-zebra:clear-evpn-dup-addr", NULL);
-		listnode_add(input, yang_dup);
-		ret = nb_cli_rpc(vty, "/frr-zebra:clear-evpn-dup-addr", input,
-				 NULL);
-	}
-
-	list_delete(&input);
-
-	return ret;
 }
 
 DEFPY_HIDDEN (evpn_accept_bgp_seq,