libyang-issue1.c

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <err.h>
#include <assert.h>
#include <arpa/inet.h>
#include <stdbool.h>

#include <libyang/libyang.h>

static struct ly_ctx *ctx;
static struct lyd_node *running, *candidate;

static void print(struct lyd_node *config)
{
	lyd_print_fd(2, config, LYD_JSON, LYP_FORMAT);
}

static void validate(struct lyd_node *config)
{
#if 0
	/*
	 * HACK: don't validate if only the top-level node is present.
	 */
	struct ly_set *set;

	set = lyd_find_path(candidate, "//*");
	if (set == NULL)
		errx(1, "lyd_find_path");

	if (set->number == 1)
		return;
#endif

	if (lyd_validate(&config, LYD_OPT_CONFIG, ctx) != 0)
		errx(1, "lyd_validate");
}

static void create_candidate(void)
{
	candidate = lyd_dup(running, 1);
	if (candidate == NULL)
		errx(1, "lyd_dup");
}

static void merge_candidate(void)
{
	lyd_free_withsiblings(running);
	running = candidate;
	candidate = NULL;
}

int main(int argc, char **argv)
{
	const struct lys_module *module;
	struct lyd_node *node;
	struct ly_set *set;
	const char *xpath_container = "/frr-ripd:ripd/instance";

	/* initialization */
	ctx = ly_ctx_new(NULL, 0);
	if (!ctx)
		errx(1, "ly_ctx_new");

	ly_ctx_set_searchdir(ctx, "/usr/local/share/yang/");
	module = lys_parse_path(ctx, "/usr/local/share/yang/frr-ripd.yang",
				LYS_IN_YANG);
	if (!module)
		errx(1, "lys_parse_path");

	running = lyd_new(NULL, module, "ripd");

	for (int i = 0; i < 2; i++) {
		printf("===========================================\n");
		printf("ADDING CONTAINER:\n");
		printf("===========================================\n");

		/* 1 - Create candidate config */
		create_candidate();

		/* 2 - Change candidate config - add presence container */
		ly_errno = 0;
		node = lyd_new_path(candidate, ctx, xpath_container, NULL, 0,
				    LYD_PATH_OPT_UPDATE);
		if (node == NULL && ly_errno)
			errx(1, "lyd_new_path");

		/*
		 * 3 - Validate candidate config
		 * 4 - Merge candidate into running
		 * 5 - Print running config
		 */
		validate(candidate);
		merge_candidate();
		print(running);

		printf("===========================================\n");
		printf("DELETING CONTAINER:\n");
		printf("===========================================\n");

		/* 1 - Create candidate config */
		create_candidate();

		/* 2 - Change candidate config - delete presence container */
		set = lyd_find_path(candidate, xpath_container);
		if (set == NULL)
			errx(1, "lyd_find_path");
		if (set->number != 1)
			errx(1, "couldn't find node");
		node = set->set.d[0];
		ly_set_free(set);
		lyd_free(node);

		/*
		 * 3 - Validate candidate config
		 * 4 - Merge candidate into running
		 * 5 - Print running config
		 */
		validate(candidate);
		merge_candidate();
		print(running);
	}

	/* cleanup */
	lyd_free_withsiblings(running);
	ly_ctx_remove_module(module, NULL);
	ly_ctx_destroy(ctx, NULL);

	return 0;
}