NetBSD/sbin/mount_union/mount_union.c

167 lines
4.4 KiB
C

/* $NetBSD: mount_union.c,v 1.14 2005/02/05 15:14:25 xtraeme Exp $ */
/*
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1992, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)mount_union.c 8.6 (Berkeley) 4/26/95";
#else
__RCSID("$NetBSD: mount_union.c,v 1.14 2005/02/05 15:14:25 xtraeme Exp $");
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/mount.h>
#include <miscfs/union/union.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
#include <mntopts.h>
static const struct mntopt mopts[] = {
MOPT_STDOPTS,
MOPT_GETARGS,
{ NULL }
};
int mount_union(int argc, char **argv);
static int subdir(const char *, const char *);
static void usage(void);
#ifndef MOUNT_NOMAIN
int
main(int argc, char **argv)
{
return mount_union(argc, argv);
}
#endif
int
mount_union(int argc, char *argv[])
{
struct union_args args;
int ch, mntflags;
char target[MAXPATHLEN], canon_dir[MAXPATHLEN];
mntflags = 0;
args.mntflags = UNMNT_ABOVE;
while ((ch = getopt(argc, argv, "bo:r")) != -1)
switch (ch) {
case 'b':
args.mntflags &= ~UNMNT_OPMASK;
args.mntflags |= UNMNT_BELOW;
break;
case 'o':
getmntopts(optarg, mopts, &mntflags, 0);
break;
case 'r':
args.mntflags &= ~UNMNT_OPMASK;
args.mntflags |= UNMNT_REPLACE;
break;
case '?':
default:
usage();
/* NOTREACHED */
}
argc -= optind;
argv += optind;
if (argc != 2)
usage();
if (realpath(argv[0], target) == NULL) /* Check device path */
err(1, "realpath %s", argv[0]);
if (strncmp(argv[0], target, MAXPATHLEN)) {
warnx("\"%s\" is a relative path.", argv[0]);
warnx("using \"%s\" instead.", target);
}
if (realpath(argv[1], canon_dir) == NULL) /* Check mounton path */
err(1, "realpath %s", argv[1]);
if (strncmp(argv[1], canon_dir, MAXPATHLEN)) {
warnx("\"%s\" is a relative path.", argv[1]);
warnx("using \"%s\" instead.", canon_dir);
}
if (subdir(target, canon_dir) || subdir(canon_dir, target))
errx(1, "%s (%s) and %s are not distinct paths",
argv[0], target, canon_dir);
args.target = target;
if (mount(MOUNT_UNION, canon_dir, mntflags, &args))
err(1, "%s on %s", target, canon_dir);
if (mntflags & MNT_GETARGS) {
char buf[1024];
(void)snprintb(buf, sizeof(buf), UNMNT_BITS, args.mntflags);
printf("flags=%s\n", buf);
}
exit(0);
}
static int
subdir(const char *p, const char *dir)
{
int l;
l = strlen(dir);
if (l <= 1)
return (1);
if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0'))
return (1);
return (0);
}
static void
usage(void)
{
(void)fprintf(stderr,
"usage: mount_union [-br] [-o options] target_fs mount_point\n");
exit(1);
}