2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
7 * This software was developed for the FreeBSD Project by Marshall
8 * Kirk McKusick and Network Associates Laboratories, the Security
9 * Research Division of Network Associates, Inc. under DARPA/SPAWAR
10 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The names of the authors may not be used to endorse or promote
22 * products derived from this software without specific prior written
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 #include <sys/param.h>
41 #include <sys/mount.h>
43 #include <ufs/ufs/ufsmount.h>
60 errx(EX_USAGE, "usage: mksnap_ffs snapshot_name");
64 isdir(const char *path, struct stat *stbufp)
67 if (stat(path, stbufp) < 0)
69 if (!S_ISDIR(stbufp->st_mode))
75 issamefs(const char *path, struct statfs *stfsp)
77 struct statfs stfsbuf;
80 if (isdir(path, &stbuf) != 1)
82 if (statfs(path, &stfsbuf) < 0)
84 if (fsidcmp(&stfsbuf.f_fsid, &stfsp->f_fsid) != 0)
90 main(int argc, char **argv)
92 char errmsg[255], path[PATH_MAX];
94 struct statfs stfsbuf;
103 snapname = argv[2]; /* Old usage. */
108 * Check that the user running this program has permission
109 * to create and remove a snapshot file from the directory
110 * in which they have requested to have it made. If the
111 * directory is sticky and not owned by the user, then they
112 * will not be able to remove the snapshot when they are
115 if (strlen(snapname) >= PATH_MAX)
116 errx(1, "pathname too long %s", snapname);
117 cp = strrchr(snapname, '/');
119 strlcpy(path, ".", PATH_MAX);
120 } else if (cp == snapname) {
121 strlcpy(path, "/", PATH_MAX);
123 strlcpy(path, snapname, cp - snapname + 1);
125 if (statfs(path, &stfsbuf) < 0)
127 switch (isdir(path, &stbuf)) {
131 errx(1, "%s: Not a directory", path);
135 if (access(path, W_OK) < 0)
136 err(1, "Lack write permission in %s", path);
137 if ((stbuf.st_mode & S_ISTXT) && stbuf.st_uid != getuid())
138 errx(1, "Lack write permission in %s: Sticky bit set", path);
141 * Work around an issue when mksnap_ffs is started in chroot'ed
142 * environment and f_mntonname contains absolute path within
145 for (cp = stfsbuf.f_mntonname; issamefs(cp, &stfsbuf) != 1;
146 cp = strchrnul(cp + 1, '/')) {
148 errx(1, "%s: Not a mount point", stfsbuf.f_mntonname);
150 if (cp != stfsbuf.f_mntonname)
151 strlcpy(stfsbuf.f_mntonname, cp, sizeof(stfsbuf.f_mntonname));
154 * Having verified access to the directory in which the
155 * snapshot is to be built, proceed with creating it.
157 if ((grp = getgrnam("operator")) == NULL)
158 errx(1, "Cannot retrieve operator gid");
162 build_iovec(&iov, &iovlen, "fstype", "ffs", 4);
163 build_iovec(&iov, &iovlen, "from", snapname, (size_t)-1);
164 build_iovec(&iov, &iovlen, "fspath", stfsbuf.f_mntonname, (size_t)-1);
165 build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
166 build_iovec(&iov, &iovlen, "update", NULL, 0);
167 build_iovec(&iov, &iovlen, "snapshot", NULL, 0);
170 if (nmount(iov, iovlen, stfsbuf.f_flags) < 0) {
171 errmsg[sizeof(errmsg) - 1] = '\0';
172 err(1, "Cannot create snapshot %s%s%s", snapname,
173 *errmsg != '\0' ? ": " : "", errmsg);
175 if ((fd = open(snapname, O_RDONLY)) < 0)
176 err(1, "Cannot open %s", snapname);
177 if (fstat(fd, &stbuf) != 0)
178 err(1, "Cannot stat %s", snapname);
179 if ((stbuf.st_flags & SF_SNAPSHOT) == 0)
180 errx(1, "File %s is not a snapshot", snapname);
181 if (fchown(fd, -1, grp->gr_gid) != 0)
182 err(1, "Cannot chown %s", snapname);
183 if (fchmod(fd, S_IRUSR | S_IRGRP) != 0)
184 err(1, "Cannot chmod %s", snapname);