ifupdown-ng/cmd/ifparse.c

/*
 * cmd/ifparse.c
 * Purpose: Redisplay /e/n/i in alternative formats.
 *
 * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * This software is provided 'as is' and without any warranty, express or
 * implied.  In no event shall the authors be liable for any damages arising
 * from the use of this software.
 */

#define _GNU_SOURCE
#include <fnmatch.h>
#include <stdio.h>
#include <string.h>
#include <getopt.h>
#include "libifupdown/libifupdown.h"

#ifdef CONFIG_YAML
# include "libifupdown/yaml-base.h"
# include "libifupdown/yaml-writer.h"
#endif

#include "cmd/multicall.h"
#include "cmd/pretty-print-iface.h"

static bool show_all = false;
static bool allow_undefined = false;

static void
set_show_all(const char *arg)
{
	(void) arg;

	show_all = true;
}

static void
set_allow_undefined(const char *arg)
{
	(void) arg;

	allow_undefined = true;
}

static const char *output_fmt = "ifupdown";

static void
set_output_fmt(const char *arg)
{
	output_fmt = arg;
}

static struct if_option local_options[] = {
	{'F', "format", NULL, "output format to use", true, set_output_fmt},
	{'A', "all", NULL, "show all interfaces", false, set_show_all},
	{'U', "allow-undefined", NULL, "allow querying undefined (virtual) interfaces", false, set_allow_undefined},
};

static struct if_option_group local_option_group = {
	.desc = "Program-specific options",
	.group_size = ARRAY_SIZE(local_options),
	.group = local_options
};

#ifdef CONFIG_YAML
static void
prettyprint_interface_yaml(struct lif_interface *iface)
{
	struct lif_yaml_node doc = {};

	lif_yaml_document_init(&doc, "interfaces");

	struct lif_yaml_node *iface_node = lif_yaml_node_new_list(iface->ifname);
	lif_yaml_node_append_child(&doc, iface_node);

	if (iface->is_auto)
	{
		struct lif_yaml_node *iface_entry_node = lif_yaml_node_new_boolean("auto", true);
		lif_yaml_node_append_child(iface_node, iface_entry_node);
	}

	struct lif_node *iter;
	LIF_DICT_FOREACH(iter, &iface->vars)
	{
		struct lif_dict_entry *entry = iter->data;
		const char *value = entry->data;
		char addr_buf[512];

		if (!strcmp(entry->key, "address"))
		{
			struct lif_address *addr = entry->data;

			if (!lif_address_unparse(addr, addr_buf, sizeof addr_buf, true))
				continue;

			value = addr_buf;
		}

		struct lif_yaml_node *iface_entry_node = lif_yaml_node_new_string(entry->key, value);
		lif_yaml_node_append_child(iface_node, iface_entry_node);
	}

	lif_yaml_write(iface_node, stdout, true);
	lif_yaml_node_free(&doc);
}
#endif

struct prettyprint_impl_map {
	const char *name;
	void (*handle)(struct lif_interface *iface);
};

struct prettyprint_impl_map pp_impl_map[] = {
	{"ifupdown", prettyprint_interface_eni},
#ifdef CONFIG_YAML
	{"yaml-raw", prettyprint_interface_yaml},
#endif
};

static int
pp_impl_cmp(const void *a, const void *b)
{
	const char *key = a;
	const struct prettyprint_impl_map *impl = b;

	return strcmp(key, impl->name);
}

int
ifparse_main(int argc, char *argv[])
{
	struct lif_dict state = {};
	struct lif_dict collection = {};
	struct lif_interface_file_parse_state parse_state = {
		.collection = &collection,
	};

	lif_interface_collection_init(&collection);

	if (!lif_state_read_path(&state, exec_opts.state_file))
	{
		fprintf(stderr, "%s: could not parse %s\n", argv0, exec_opts.state_file);
		return EXIT_FAILURE;
	}

	if (!lif_interface_file_parse(&parse_state, exec_opts.interfaces_file))
	{
		fprintf(stderr, "%s: could not parse %s\n", argv0, exec_opts.interfaces_file);
		return EXIT_FAILURE;
	}

	if (match_opts.property == NULL && lif_lifecycle_count_rdepends(&exec_opts, &collection) == -1)
	{
		fprintf(stderr, "%s: could not validate dependency tree\n", argv0);
		return EXIT_FAILURE;
	}

	if (!lif_compat_apply(&collection))
	{
		fprintf(stderr, "%s: failed to apply compatibility glue\n", argv0);
		return EXIT_FAILURE;
	}

	struct prettyprint_impl_map *m = bsearch(output_fmt, pp_impl_map, ARRAY_SIZE(pp_impl_map), sizeof(*m), pp_impl_cmp);
	if (m == NULL)
	{
		fprintf(stderr, "%s: %s: output format not supported\n", argv0, output_fmt);
		return EXIT_FAILURE;
	}

	if (show_all)
	{
		struct lif_node *n;

		LIF_DICT_FOREACH(n, &collection)
		{
			struct lif_dict_entry *entry = n->data;

			m->handle(entry->data);
		}

		return EXIT_SUCCESS;
	}

	if (optind >= argc)
		generic_usage(self_applet, EXIT_FAILURE);

	int idx = optind;
	for (; idx < argc; idx++)
	{
		struct lif_dict_entry *entry = lif_dict_find(&collection, argv[idx]);
		struct lif_interface *iface = NULL;

		if (entry != NULL)
			iface = entry->data;

		if (entry == NULL && allow_undefined)
			iface = lif_interface_collection_find(&collection, argv[idx]);

		if (iface == NULL)
		{
			fprintf(stderr, "%s: unknown interface %s\n", argv0, argv[idx]);
			return EXIT_FAILURE;
		}

		m->handle(iface);
	}

	return EXIT_SUCCESS;
}

struct if_applet ifparse_applet = {
	.name = "ifparse",
	.desc = "redisplay interface configuration",
	.main = ifparse_main,
	.usage = "ifparse [options] <interfaces>\n  ifparse [options] --all",
	.manpage = "8 ifparse",
	.groups = { &global_option_group, &match_option_group, &exec_option_group, &local_option_group },
};