lib: rework northbound RPC callback

Change input/output arguments of the RPC callback from lists of
(xpath/value) tuples to YANG data trees.

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>

7 files changed, 140 insertions, 100 deletions

diff --git a/lib/northbound.c b/lib/northbound.c
index 9a5d67cd1..57068cc4e 100644
--- a/lib/northbound.c
+++ b/lib/northbound.c
@@ -1820,14 +1820,11 @@ 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,
-		    size_t errmsg_len)
+		    const struct lyd_node *input, struct lyd_node *output,
+		    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;
diff --git a/lib/northbound.h b/lib/northbound.h
index 3bf1eacd6..34d17a587 100644
--- a/lib/northbound.h
+++ b/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. */
-	const struct list *input;
+	/* Read-only "input" tree of the RPC/action. */
+	const struct lyd_node *input;
 
-	/* List of output parameters to be populated by the callback. */
-	struct list *output;
+	/* The "output" tree of the RPC/action to be populated by the callback. */
+	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);
diff --git a/lib/northbound_cli.c b/lib/northbound_cli.c
index 8809ec2ad..5be64f013 100644
--- a/lib/northbound_cli.c
+++ b/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,
-	       struct list *output)
+int nb_cli_rpc_enqueue(struct vty *vty, const char *xpath, const char *value)
+{
+	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 +310,46 @@ 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);
+	}
+
+	/* 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;
diff --git a/lib/northbound_cli.h b/lib/northbound_cli.h
index 1a45794d4..4c8dc50bd 100644
--- a/lib/northbound_cli.h
+++ b/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
- *    List of 'yang_data' structures containing the RPC input parameters. It
- *    can be set to NULL when there are no input parameters.
- *
- * 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.
+ * output_p
+ *    A pointer to the libyang data node that will hold the output data tree.
+ *    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.
  *
  * Returns:
  *    CMD_SUCCESS on success, CMD_WARNING otherwise.
  */
-extern int nb_cli_rpc(struct vty *vty, const char *xpath, struct list *input,
-		      struct list *output);
+extern int nb_cli_rpc(struct vty *vty, const char *xpath,
+		      struct lyd_node **output_p);
 
 /*
  * Show CLI commands associated to the given YANG data node.
diff --git a/lib/northbound_grpc.cpp b/lib/northbound_grpc.cpp
index 795775258..612ec3981 100644
--- a/lib/northbound_grpc.cpp
+++ b/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 list *output_list;
-	struct listnode *node;
-	struct yang_data *data;
+	struct lyd_node *input_tree, *output_tree, *child;
 	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();
-	output_list = yang_data_list_new();
+	// Create input data tree.
+	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());
-		listnode_add(input_list, data);
+		err = lyd_new_path(input_tree, ly_native_ctx, pv.path().c_str(),
+				   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,
-			    sizeof(errmsg))
-	    != NB_OK) {
+	if (nb_callback_rpc(nb_node, xpath, input_tree, output_tree, errmsg,
+			    sizeof(errmsg)) != NB_OK) {
 		flog_warn(EC_LIB_NB_CB_RPC, "%s: rpc callback failed: %s",
 			  __func__, xpath);
-		list_delete(&input_list);
-		list_delete(&output_list);
+		lyd_free_tree(input_tree);
+		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_value(data->value);
+		pv->set_path(lyd_path(child, LYD_PATH_STD, path, sizeof(path)));
+		pv->set_value(yang_dnode_get_string(child, NULL));
 	}
 
 	// Release memory.
-	list_delete(&input_list);
-	list_delete(&output_list);
+	lyd_free_tree(input_tree);
+	lyd_free_tree(output_tree);
 
 	return grpc::Status::OK;
 }
diff --git a/lib/northbound_sysrepo.c b/lib/northbound_sysrepo.c
index 640334926..0ec7610a9 100644
--- a/lib/northbound_sysrepo.c
+++ b/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 size_t input_cnt, sr_event_t sr_ev,
-				uint32_t request_id, sr_val_t **sr_output,
-				size_t *sr_output_cnt, void *private_ctx)
+				const char *xpath, const struct lyd_node *input,
+				sr_event_t sr_ev, uint32_t request_id,
+				struct lyd_node *output, 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,
-			       NULL, 0, 0, &module->sr_subscription);
+	ret = sr_rpc_subscribe_tree(session, nb_node->xpath,
+				    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));
diff --git a/lib/vty.h b/lib/vty.h
index 0e0c92c33..a51cee76f 100644
--- a/lib/vty.h
+++ b/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];