xref: /freebsd/sbin/mount_nullfs/mount_nullfs.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #ifndef lint
36 static const char copyright[] =
37 "@(#) Copyright (c) 1992, 1993, 1994\n\
38 	The Regents of the University of California.  All rights reserved.\n";
39 #endif /* not lint */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)mount_null.c	8.6 (Berkeley) 4/26/95";
44 #endif
45 static const char rcsid[] =
46   "$FreeBSD$";
47 #endif /* not lint */
48 
49 #include <sys/param.h>
50 #include <sys/mount.h>
51 #include <sys/uio.h>
52 
53 #include <err.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <sysexits.h>
58 #include <unistd.h>
59 
60 #include "mntopts.h"
61 
62 static void	usage(void) __dead2;
63 
64 int
65 main(int argc, char *argv[])
66 {
67 	struct iovec *iov;
68 	char *p, *val;
69 	char mountpoint[MAXPATHLEN];
70 	char target[MAXPATHLEN];
71 	char errmsg[255];
72 	int ch, iovlen;
73 	char nullfs[] = "nullfs";
74 
75 	iov = NULL;
76 	iovlen = 0;
77 	errmsg[0] = '\0';
78 	while ((ch = getopt(argc, argv, "o:")) != -1)
79 		switch(ch) {
80 		case 'o':
81 			val = strdup("");
82 			p = strchr(optarg, '=');
83 			if (p != NULL) {
84 				free(val);
85 				*p = '\0';
86 				val = p + 1;
87 			}
88 			build_iovec(&iov, &iovlen, optarg, val, (size_t)-1);
89 			break;
90 		case '?':
91 		default:
92 			usage();
93 		}
94 	argc -= optind;
95 	argv += optind;
96 
97 	if (argc != 2)
98 		usage();
99 
100 	/* resolve target and mountpoint with realpath(3) */
101 	if (checkpath(argv[0], target) != 0)
102 		err(EX_USAGE, "%s", target);
103 	if (checkpath(argv[1], mountpoint) != 0)
104 		err(EX_USAGE, "%s", mountpoint);
105 
106 	build_iovec(&iov, &iovlen, "fstype", nullfs, (size_t)-1);
107 	build_iovec(&iov, &iovlen, "fspath", mountpoint, (size_t)-1);
108 	build_iovec(&iov, &iovlen, "target", target, (size_t)-1);
109 	build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
110 	if (nmount(iov, iovlen, 0) < 0) {
111 		if (errmsg[0] != 0)
112 			err(1, "%s: %s", mountpoint, errmsg);
113 		else
114 			err(1, "%s", mountpoint);
115 	}
116 	exit(0);
117 }
118 
119 static void
120 usage(void)
121 {
122 	(void)fprintf(stderr,
123 		"usage: mount_nullfs [-o options] target mount-point\n");
124 	exit(1);
125 }
126