freebsd-dev/sbin/mount_unionfs/mount_unionfs.c
2007-02-13 05:39:38 +00:00

195 lines
5.2 KiB
C

/*-
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California.
* Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
* Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
* 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.
* 4. 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.
*/
#ifndef lint
static const char 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 8.5 (Berkeley) 3/27/94";
#else
static const char rcsid[] =
"$FreeBSD$";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/uio.h>
#include <sys/errno.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <grp.h>
#include <pwd.h>
#include "mntopts.h"
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_unionfs [-o options] directory uniondir\n");
exit(EX_USAGE);
}
static void
parse_gid(const char *s, char *buf, size_t bufsize)
{
struct group *gr;
char *inval;
if ((gr = getgrnam(s)) != NULL)
snprintf(buf, bufsize, "%d", gr->gr_gid);
else {
strtol(s, &inval, 10);
if (*inval != 0) {
errx(EX_NOUSER, "unknown group id: %s", s);
usage();
} else {
strncpy(buf, s, bufsize);
}
}
}
static void
parse_uid(const char *s, char *buf, size_t bufsize)
{
struct passwd *pw;
char *inval;
if ((pw = getpwnam(s)) != NULL)
snprintf(buf, bufsize, "%d", pw->pw_uid);
else {
strtol(s, &inval, 10);
if (*inval != 0) {
errx(EX_NOUSER, "unknown user id: %s", s);
usage();
} else {
strncpy(buf, s, bufsize);
}
}
}
int
main(int argc, char *argv[])
{
struct iovec *iov;
int ch, mntflags, iovlen;
char source [MAXPATHLEN], target[MAXPATHLEN], errmsg[255];
char uid_str[20], gid_str[20];
char fstype[] = "unionfs";
char *p, *val;
iov = NULL;
iovlen = 0;
mntflags = 0;
memset(errmsg, 0, sizeof(errmsg));
while ((ch = getopt(argc, argv, "bo:")) != -1) {
switch (ch) {
case 'b':
printf("\n -b is deprecated. Use \"-o below\" instead\n");
build_iovec(&iov, &iovlen, "below", NULL, 0);
break;
case 'o':
p = strchr(optarg, '=');
val = NULL;
if (p != NULL) {
*p = '\0';
val = p + 1;
if (strcmp(optarg, "gid") == 0) {
parse_gid(val, gid_str, sizeof(gid_str));
val = gid_str;
}
else if (strcmp(optarg, "uid") == 0) {
parse_uid(val, uid_str, sizeof(uid_str));
val = uid_str;
}
}
build_iovec(&iov, &iovlen, optarg, val, (size_t)-1);
break;
case '?':
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
if (argc != 2)
usage();
/* resolve both target and source with realpath(3) */
(void)checkpath(argv[0], target);
(void)checkpath(argv[1], source);
if (subdir(target, source) || subdir(source, target))
errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths",
argv[0], target, argv[1], source);
build_iovec(&iov, &iovlen, "fstype", fstype, (size_t)-1);
build_iovec(&iov, &iovlen, "fspath", source, (size_t)-1);
build_iovec(&iov, &iovlen, "from", target, (size_t)-1);
build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
if (nmount(iov, iovlen, mntflags))
err(EX_OSERR, "%s: %s", source, errmsg);
exit(0);
}