xref: /freebsd/sbin/mksnap_ffs/mksnap_ffs.c (revision d62e00647350b65196c9a32d7cf8d3d57ae964e8)
1d35ae777SKirk McKusick /*
2d35ae777SKirk McKusick  * Copyright (c) 2003 Networks Associates Technology, Inc.
3d35ae777SKirk McKusick  * All rights reserved.
4d35ae777SKirk McKusick  *
5d35ae777SKirk McKusick  * This software was developed for the FreeBSD Project by Marshall
6d35ae777SKirk McKusick  * Kirk McKusick and Network Associates Laboratories, the Security
7d35ae777SKirk McKusick  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
8d35ae777SKirk McKusick  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
9d35ae777SKirk McKusick  * research program.
10d35ae777SKirk McKusick  *
11d35ae777SKirk McKusick  * Redistribution and use in source and binary forms, with or without
12d35ae777SKirk McKusick  * modification, are permitted provided that the following conditions
13d35ae777SKirk McKusick  * are met:
14d35ae777SKirk McKusick  * 1. Redistributions of source code must retain the above copyright
15d35ae777SKirk McKusick  *    notice, this list of conditions and the following disclaimer.
16d35ae777SKirk McKusick  * 2. Redistributions in binary form must reproduce the above copyright
17d35ae777SKirk McKusick  *    notice, this list of conditions and the following disclaimer in the
18d35ae777SKirk McKusick  *    documentation and/or other materials provided with the distribution.
19d35ae777SKirk McKusick  * 3. The names of the authors may not be used to endorse or promote
20d35ae777SKirk McKusick  *    products derived from this software without specific prior written
21d35ae777SKirk McKusick  *    permission.
22d35ae777SKirk McKusick  *
23d35ae777SKirk McKusick  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24d35ae777SKirk McKusick  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25d35ae777SKirk McKusick  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26d35ae777SKirk McKusick  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27d35ae777SKirk McKusick  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28d35ae777SKirk McKusick  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29d35ae777SKirk McKusick  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30d35ae777SKirk McKusick  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31d35ae777SKirk McKusick  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32d35ae777SKirk McKusick  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33d35ae777SKirk McKusick  * SUCH DAMAGE.
34d35ae777SKirk McKusick  *
35d35ae777SKirk McKusick  * $FreeBSD$
36d35ae777SKirk McKusick  */
37d35ae777SKirk McKusick 
38d35ae777SKirk McKusick #include <sys/param.h>
39d35ae777SKirk McKusick #include <sys/mount.h>
40d35ae777SKirk McKusick #include <sys/stat.h>
41d35ae777SKirk McKusick #include <ufs/ufs/ufsmount.h>
42d35ae777SKirk McKusick #include <err.h>
43d35ae777SKirk McKusick #include <errno.h>
446d540f81SKirk McKusick #include <fcntl.h>
45d35ae777SKirk McKusick #include <grp.h>
46d62e0064SKirk McKusick #include <limits.h>
47d35ae777SKirk McKusick #include <stdio.h>
48d35ae777SKirk McKusick #include <stdlib.h>
49d35ae777SKirk McKusick #include <string.h>
50d35ae777SKirk McKusick #include <sysexits.h>
51d35ae777SKirk McKusick #include <unistd.h>
52d35ae777SKirk McKusick 
5391b6ac7cSTom Rhodes void usage(void);
5491b6ac7cSTom Rhodes 
55d35ae777SKirk McKusick int
56d35ae777SKirk McKusick main(int argc, char **argv)
57d35ae777SKirk McKusick {
58d62e0064SKirk McKusick 	char *dir, *cp, path[PATH_MAX];
59d35ae777SKirk McKusick 	struct ufs_args args;
60d35ae777SKirk McKusick 	struct group *grp;
616d540f81SKirk McKusick 	struct stat stbuf;
626d540f81SKirk McKusick 	int fd;
63d35ae777SKirk McKusick 
64d35ae777SKirk McKusick 	if (argc != 3)
65d35ae777SKirk McKusick 		usage();
66d35ae777SKirk McKusick 
67d35ae777SKirk McKusick 	dir = argv[1];
68d35ae777SKirk McKusick 	args.fspec = argv[2];
69d35ae777SKirk McKusick 
70d62e0064SKirk McKusick 	/*
71d62e0064SKirk McKusick 	 * Check that the user running this program has permission
72d62e0064SKirk McKusick 	 * to create and remove a snapshot file from the directory
73d62e0064SKirk McKusick 	 * in which they have requested to have it made. If the
74d62e0064SKirk McKusick 	 * directory is sticky and not owned by the user, then they
75d62e0064SKirk McKusick 	 * will not be able to remove the snapshot when they are
76d62e0064SKirk McKusick 	 * done with it.
77d62e0064SKirk McKusick 	 */
78d62e0064SKirk McKusick 	if (strlen(args.fspec) >= PATH_MAX)
79d62e0064SKirk McKusick 		errx(1, "pathname too long %s", args.fspec);
80d62e0064SKirk McKusick 	cp = strrchr(args.fspec, '/');
81d62e0064SKirk McKusick 	if (cp == NULL) {
82d62e0064SKirk McKusick 		strlcpy(path, ".", PATH_MAX);
83d62e0064SKirk McKusick 	} else if (cp == args.fspec) {
84d62e0064SKirk McKusick 		strlcpy(path, "/", PATH_MAX);
85d62e0064SKirk McKusick 	} else {
86d62e0064SKirk McKusick 		strlcpy(path, args.fspec, cp - args.fspec + 1);
87d62e0064SKirk McKusick 	}
88d62e0064SKirk McKusick 	if (stat(path, &stbuf) < 0)
89d62e0064SKirk McKusick 		err(1, "%s", path);
90d62e0064SKirk McKusick 	if (!S_ISDIR(stbuf.st_mode))
91d62e0064SKirk McKusick 		errx(1, "%s: Not a directory", path);
92d62e0064SKirk McKusick 	if (access(path, W_OK) < 0)
93d62e0064SKirk McKusick 		err(1, "Lack write permission in %s", path);
94d62e0064SKirk McKusick 	if ((stbuf.st_mode & S_ISTXT) && stbuf.st_uid != getuid())
95d62e0064SKirk McKusick 		errx(1, "Lack write permission in %s: Sticky bit set", path);
96d62e0064SKirk McKusick 
97d62e0064SKirk McKusick 	/*
98d62e0064SKirk McKusick 	 * Having verified access to the directory in which the
99d62e0064SKirk McKusick 	 * snapshot is to be built, proceed with creating it.
100d62e0064SKirk McKusick 	 */
101d35ae777SKirk McKusick 	if ((grp = getgrnam("operator")) == NULL)
102d35ae777SKirk McKusick 		errx(1, "Cannot retrieve operator gid");
103d35ae777SKirk McKusick 	if (mount("ffs", dir, MNT_UPDATE | MNT_SNAPSHOT, &args) < 0)
104d35ae777SKirk McKusick 		err(1, "Cannot create %s", args.fspec);
1056d540f81SKirk McKusick 	if ((fd = open(args.fspec, O_RDONLY)) < 0)
1066d540f81SKirk McKusick 		err(1, "Cannot open %s", args.fspec);
1076d540f81SKirk McKusick 	if (fstat(fd, &stbuf) != 0)
1086d540f81SKirk McKusick 		err(1, "Cannot stat %s", args.fspec);
1096d540f81SKirk McKusick 	if ((stbuf.st_flags & SF_SNAPSHOT) == 0)
1106d540f81SKirk McKusick 		errx(1, "File %s is not a snapshot", args.fspec);
1116d540f81SKirk McKusick 	if (fchown(fd, -1, grp->gr_gid) != 0)
112d35ae777SKirk McKusick 		err(1, "Cannot chown %s", args.fspec);
1136d540f81SKirk McKusick 	if (fchmod(fd, S_IRUSR | S_IRGRP) != 0)
114d35ae777SKirk McKusick 		err(1, "Cannot chmod %s", args.fspec);
115d35ae777SKirk McKusick 
116d35ae777SKirk McKusick 	exit(EXIT_SUCCESS);
117d35ae777SKirk McKusick }
118201747dfSTom Rhodes 
119201747dfSTom Rhodes void
120201747dfSTom Rhodes usage()
121201747dfSTom Rhodes {
122201747dfSTom Rhodes 
123201747dfSTom Rhodes 	fprintf(stderr, "usage: mksnap_ffs mountpoint snapshot_name\n");
124201747dfSTom Rhodes 	exit(EX_USAGE);
125201747dfSTom Rhodes }
126