/*

 * libcryptsetup API log example

 *

 * Copyright (C) 2011-2020 Red Hat, Inc. All rights reserved.

 *

 * This file is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This file 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this file; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include <stdio.h>

#include <sys/types.h>

#include <syslog.h>

#include <unistd.h>

#include <libcryptsetup.h>

/*

 * This is an example of crypt_set_log_callback API callback.

 *

 */

static void simple_syslog_wrapper(int level, const char *msg, void *usrptr)

{

	const char *prefix = (const char *)usrptr;

	int priority;

	switch(level) {

		case CRYPT_LOG_NORMAL:  priority = LOG_NOTICE; break;

		case CRYPT_LOG_ERROR:   priority = LOG_ERR;    break;

		case CRYPT_LOG_VERBOSE: priority = LOG_INFO;   break;

		case CRYPT_LOG_DEBUG:   priority = LOG_DEBUG;  break;

		default:

			fprintf(stderr, "Unsupported log level requested!\n");

			return;

	}

	if (prefix)

		syslog(priority, "%s:%s", prefix, msg);

	else

		syslog(priority, "%s", msg);

}

int main(void)

{

	struct crypt_device *cd;

	char usrprefix[] = "cslog_example";

	int r;

	if (geteuid()) {

		printf("Using of libcryptsetup requires super user privileges.\n");

		return 1;

	}

	openlog("cryptsetup", LOG_CONS | LOG_PID, LOG_USER);

	/* Initialize empty crypt device context */

	r = crypt_init(&cd, NULL);

	if (r < 0) {

		printf("crypt_init() failed.\n");

		return 2;

	}

	/* crypt_set_log_callback() - register a log callback for crypt context */

	crypt_set_log_callback(cd, &simple_syslog_wrapper, (void *)usrprefix);

	/* send messages ithrough the crypt_log() interface */

	crypt_log(cd, CRYPT_LOG_NORMAL, "This is normal log message");

	crypt_log(cd, CRYPT_LOG_ERROR, "This is error log message");

	crypt_log(cd, CRYPT_LOG_VERBOSE, "This is verbose log message");

	crypt_log(cd, CRYPT_LOG_DEBUG, "This is debug message");

	/* release crypt context */

	crypt_free(cd);

	/* Initialize default (global) log callback */

	crypt_set_log_callback(NULL, &simple_syslog_wrapper, NULL);

	crypt_log(NULL, CRYPT_LOG_NORMAL, "This is normal log message");

	crypt_log(NULL, CRYPT_LOG_ERROR, "This is error log message");

	crypt_log(NULL, CRYPT_LOG_VERBOSE, "This is verbose log message");

	crypt_log(NULL, CRYPT_LOG_DEBUG, "This is debug message");

	closelog();

	return 0;

}