/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Marshall
* Kirk McKusick and Network Associates Laboratories, the Security
* Research Division of Network Associates, Inc. under DARPA/SPAWAR
* contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
* research program.
*
* 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. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <mntopts.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
static void
usage(void)
{
errx(EX_USAGE, "usage: mksnap_ffs snapshot_name");
}
static int
isdir(const char *path, struct stat *stbufp)
{
if (stat(path, stbufp) < 0)
return (-1);
if (!S_ISDIR(stbufp->st_mode))
return (0);
return (1);
}
static int
issamefs(const char *path, struct statfs *stfsp)
{
struct statfs stfsbuf;
struct stat stbuf;
if (isdir(path, &stbuf) != 1)
return (-1);
if (statfs(path, &stfsbuf) < 0)
return (-1);
if (fsidcmp(&stfsbuf.f_fsid, &stfsp->f_fsid) != 0)
return (0);
return (1);
}
int
main(int argc, char **argv)
{
char errmsg[255], path[PATH_MAX];
char *cp, *snapname;
struct statfs stfsbuf;
struct group *grp;
struct stat stbuf;
struct iovec *iov;
int fd, iovlen;
if (argc == 2)
snapname = argv[1];
else if (argc == 3)
snapname = argv[2]; /* Old usage. */
else
usage();
/*
* Check that the user running this program has permission
* to create and remove a snapshot file from the directory
* in which they have requested to have it made. If the
* directory is sticky and not owned by the user, then they
* will not be able to remove the snapshot when they are
* done with it.
*/
if (strlen(snapname) >= PATH_MAX)
errx(1, "pathname too long %s", snapname);
cp = strrchr(snapname, '/');
if (cp == NULL) {
strlcpy(path, ".", PATH_MAX);
} else if (cp == snapname) {
strlcpy(path, "/", PATH_MAX);
} else {
strlcpy(path, snapname, cp - snapname + 1);
}
if (statfs(path, &stfsbuf) < 0)
err(1, "%s", path);
switch (isdir(path, &stbuf)) {
case -1:
err(1, "%s", path);
case 0:
errx(1, "%s: Not a directory", path);
default:
break;
}
if (access(path, W_OK) < 0)
err(1, "Lack write permission in %s", path);
if ((stbuf.st_mode & S_ISTXT) && stbuf.st_uid != getuid())
errx(1, "Lack write permission in %s: Sticky bit set", path);
/*
* Work around an issue when mksnap_ffs is started in chroot'ed
* environment and f_mntonname contains absolute path within
* real root.
*/
for (cp = stfsbuf.f_mntonname; issamefs(cp, &stfsbuf) != 1;
cp = strchrnul(cp + 1, '/')) {
if (cp[0] == '\0')
errx(1, "%s: Not a mount point", stfsbuf.f_mntonname);
}
if (cp != stfsbuf.f_mntonname)
strlcpy(stfsbuf.f_mntonname, cp, sizeof(stfsbuf.f_mntonname));
/*
* Having verified access to the directory in which the
* snapshot is to be built, proceed with creating it.
*/
if ((grp = getgrnam("operator")) == NULL)
errx(1, "Cannot retrieve operator gid");
iov = NULL;
iovlen = 0;
build_iovec(&iov, &iovlen, "fstype", "ffs", 4);
build_iovec(&iov, &iovlen, "from", snapname, (size_t)-1);
build_iovec(&iov, &iovlen, "fspath", stfsbuf.f_mntonname, (size_t)-1);
build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
build_iovec(&iov, &iovlen, "update", NULL, 0);
build_iovec(&iov, &iovlen, "snapshot", NULL, 0);
*errmsg = '\0';
if (nmount(iov, iovlen, stfsbuf.f_flags) < 0) {
errmsg[sizeof(errmsg) - 1] = '\0';
err(1, "Cannot create snapshot %s%s%s", snapname,
*errmsg != '\0' ? ": " : "", errmsg);
}
if ((fd = open(snapname, O_RDONLY)) < 0)
err(1, "Cannot open %s", snapname);
if (fstat(fd, &stbuf) != 0)
err(1, "Cannot stat %s", snapname);
if ((stbuf.st_flags & SF_SNAPSHOT) == 0)
errx(1, "File %s is not a snapshot", snapname);
if (fchown(fd, -1, grp->gr_gid) != 0)
err(1, "Cannot chown %s", snapname);
if (fchmod(fd, S_IRUSR | S_IRGRP) != 0)
err(1, "Cannot chmod %s", snapname);
exit(EXIT_SUCCESS);
}
