xref: /netbsd-src/sys/modules/examples/fopsmapper/cmd_mapper.c (revision 212c9b3b52d0f45cb4a5c673ffdad2160584d688)
1*212c9b3bSriastradh /*	$NetBSD: cmd_mapper.c,v 1.3 2024/04/17 18:10:27 riastradh Exp $	*/
22c306a0eSkamil 
32c306a0eSkamil /*-
42c306a0eSkamil  * Copyright (c) 2020 The NetBSD Foundation, Inc.
52c306a0eSkamil  * All rights reserved.
62c306a0eSkamil  *
72c306a0eSkamil  * Redistribution and use in source and binary forms, with or without
82c306a0eSkamil  * modification, are permitted provided that the following conditions
92c306a0eSkamil  * are met:
102c306a0eSkamil  * 1. Redistributions of source code must retain the above copyright
112c306a0eSkamil  *    notice, this list of conditions and the following disclaimer.
122c306a0eSkamil  * 2. Redistributions in binary form must reproduce the above copyright
132c306a0eSkamil  *    notice, this list of conditions and the following disclaimer in the
142c306a0eSkamil  *    documentation and/or other materials provided with the distribution.
152c306a0eSkamil  *
162c306a0eSkamil  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
172c306a0eSkamil  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
182c306a0eSkamil  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
192c306a0eSkamil  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
202c306a0eSkamil  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
212c306a0eSkamil  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
222c306a0eSkamil  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
232c306a0eSkamil  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
242c306a0eSkamil  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
252c306a0eSkamil  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
262c306a0eSkamil  * POSSIBILITY OF SUCH DAMAGE.
272c306a0eSkamil  */
282c306a0eSkamil 
292c306a0eSkamil #include <sys/cdefs.h>
30*212c9b3bSriastradh __RCSID("$NetBSD: cmd_mapper.c,v 1.3 2024/04/17 18:10:27 riastradh Exp $");
312c306a0eSkamil 
322c306a0eSkamil #include <sys/mman.h>
332c306a0eSkamil 
342c306a0eSkamil #include <err.h>
352c306a0eSkamil #include <fcntl.h>
362c306a0eSkamil #include <stdio.h>
372c306a0eSkamil #include <stdlib.h>
382c306a0eSkamil #include <unistd.h>
392c306a0eSkamil 
402c306a0eSkamil #define	_PATH_DEV_MAPPER	"/dev/fopsmapper"
412c306a0eSkamil 
main(int argc,char ** argv)422c306a0eSkamil int main(int argc, char **argv)
432c306a0eSkamil {
442c306a0eSkamil 	int devfd;
452c306a0eSkamil 	char *map = NULL;
462c306a0eSkamil 
472c306a0eSkamil 	if ((devfd = open(_PATH_DEV_MAPPER, O_RDONLY)) == -1)
482c306a0eSkamil 		err(EXIT_FAILURE, "Cannot open %s", _PATH_DEV_MAPPER);
492c306a0eSkamil 
50*212c9b3bSriastradh 	map = mmap(0, sysconf(_SC_PAGESIZE), PROT_READ, MAP_SHARED, devfd, 0);
512c306a0eSkamil 	if (map == MAP_FAILED)
522c306a0eSkamil 		err(EXIT_FAILURE, "Mapping failed");
532c306a0eSkamil 
542c306a0eSkamil 	printf("Message from device: %s\n", map);
552c306a0eSkamil 
562c306a0eSkamil 	if (munmap(map, sysconf(_SC_PAGESIZE)) == -1)
572c306a0eSkamil 		err(EXIT_FAILURE, "Unmap failed");
582c306a0eSkamil 
592c306a0eSkamil 	if (close(devfd) == -1)
602c306a0eSkamil 		err(EXIT_FAILURE, "Cannot close %s", _PATH_DEV_MAPPER);
612c306a0eSkamil 
622c306a0eSkamil 	return EXIT_SUCCESS;
632c306a0eSkamil }
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