cmd_mapper.c revision 1.1 
1/*	$NetBSD: cmd_mapper.c,v 1.1 2020/04/01 01:57:20 kamil Exp $	*/
2
3/*-
4 * Copyright (c) 2020 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__RCSID("$NetBSD");
31
32#include <sys/mman.h>
33
34#include <err.h>
35#include <fcntl.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <unistd.h>
39
40#define _PATH_DEV_MAPPER "/dev/fopsmapper"
41
42int main(int argc, char **argv)
43{
44	int devfd;
45	char *map = NULL;
46
47	if ((devfd = open(_PATH_DEV_MAPPER, O_RDONLY)) == -1)
48		err(EXIT_FAILURE, "Cannot open %s", _PATH_DEV_MAPPER);
49
50	map = (char *)(mmap(0, sysconf(_SC_PAGESIZE), PROT_READ, MAP_SHARED,
51				devfd, 0));
52	if (map == MAP_FAILED)
53		err(EXIT_FAILURE, "Mapping failed");
54
55	printf("Message from device: %s\n",map);
56
57	if (munmap(map, sysconf(_SC_PAGESIZE)) == -1)
58		err(EXIT_FAILURE, "Unmap failed");
59
60	if (close(devfd) == -1)
61		err(EXIT_FAILURE, "Cannot close %s", _PATH_DEV_MAPPER);
62
63	return EXIT_SUCCESS;
64}
65