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      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 
     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