1 /* $NetBSD: cmd_mapper.c,v 1.3 2024/04/17 18:10:27 riastradh 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: cmd_mapper.c,v 1.3 2024/04/17 18:10:27 riastradh Exp $");
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
main(int argc,char ** argv)42 int 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 = mmap(0, sysconf(_SC_PAGESIZE), PROT_READ, MAP_SHARED, devfd, 0);
51 if (map == MAP_FAILED)
52 err(EXIT_FAILURE, "Mapping failed");
53
54 printf("Message from device: %s\n", map);
55
56 if (munmap(map, sysconf(_SC_PAGESIZE)) == -1)
57 err(EXIT_FAILURE, "Unmap failed");
58
59 if (close(devfd) == -1)
60 err(EXIT_FAILURE, "Cannot close %s", _PATH_DEV_MAPPER);
61
62 return EXIT_SUCCESS;
63 }
64