Add libconfig implementation and tests

[lttng-tools.git] / src / common / config / config.c

/*
 * Copyright (C) 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License, version 2 only, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#include <assert.h>
#include <config.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <common/defaults.h>
#include <common/error.h>
#include <common/macros.h>
#include <common/utils.h>

#include "config.h"

struct handler_filter_args {
	const char* section;
	config_entry_handler_cb handler;
	void *user_data;
};

const char * const config_str_yes = "yes";
const char * const config_str_true = "true";
const char * const config_str_on = "on";
const char * const config_str_no = "no";
const char * const config_str_false = "false";
const char * const config_str_off = "off";

static int config_entry_handler_filter(struct handler_filter_args *args,
		const char *section, const char *name, const char *value)
{
	int ret = 0;
	struct config_entry entry = { section, name, value };

	assert(args);

	if (!section || !name || !value) {
		ret = -EIO;
		goto end;
	}

	if (args->section) {
		if (strcmp(args->section, section)) {
			goto end;
		}
	}

	ret = args->handler(&entry, args->user_data);
end:
	return ret;
}

LTTNG_HIDDEN
int config_get_section_entries(const char *override_path, const char *section,
		config_entry_handler_cb handler, void *user_data)
{
	int ret = 0;
	FILE *config_file = NULL;
	struct handler_filter_args filter = { section, handler, user_data };

	if (override_path) {
		config_file = fopen(override_path, "r");
		if (config_file) {
			DBG("Loaded daemon configuration file at %s",
				override_path);
		} else {
			ERR("Failed to open daemon configuration file at %s",
				override_path);
			ret = -ENOENT;
			goto end;
		}
	} else {
		char *path = utils_get_home_dir();

		/* Try to open the user's daemon configuration file */
		if (path) {
			ret = asprintf(&path, DEFAULT_DAEMON_HOME_CONFIGPATH, path);
			if (ret < 0) {
				goto end;
			}

			ret = 0;
			config_file = fopen(path, "r");
			if (config_file) {
				DBG("Loaded daemon configuration file at %s", path);
			}

			free(path);
		}

		/* Try to open the system daemon configuration file */
		if (!config_file) {
			config_file = fopen(DEFAULT_DAEMON_HOME_CONFIGPATH, "r");
		}
	}

	if (!config_file) {
		DBG("No daemon configuration file found.");
		goto end;
	}

	ret = ini_parse_file(config_file,
			(ini_entry_handler) config_entry_handler_filter, (void *) &filter);

end:
	return ret;
}

LTTNG_HIDDEN
int config_parse_value(const char *value)
{
	int i, ret = 0;
	char *endptr, *lower_str;
	size_t len;
	unsigned long v;

	len = strlen(value);
	if (!len) {
		ret = -1;
		goto end;
	}

	v = strtoul(value, &endptr, 10);
	if (endptr != value) {
		ret = v;
		goto end;
	}

	lower_str = zmalloc(len + 1);
	if (!lower_str) {
		PERROR("zmalloc");
		ret = -errno;
		goto end;
	}

	for (i = 0; i < len; i++) {
		lower_str[i] = tolower(value[i]);
	}

	if (!strcmp(lower_str, config_str_yes) ||
		!strcmp(lower_str, config_str_true) ||
		!strcmp(lower_str, config_str_on)) {
		ret = 1;
	} else if (!strcmp(lower_str, config_str_no) ||
		!strcmp(lower_str, config_str_false) ||
		!strcmp(lower_str, config_str_off)) {
		ret = 0;
	} else {
		ret = -1;
	}

	free(lower_str);
end:
	return ret;
}