d62e006473
remove a snapshot file from the directory in which they have requested to have it made. If they do not have write permission in the directory or 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.
126 lines
4.1 KiB
C
126 lines
4.1 KiB
C
/*
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* Copyright (c) 2003 Networks Associates Technology, Inc.
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* All rights reserved.
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*
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* This software was developed for the FreeBSD Project by Marshall
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* Kirk McKusick and Network Associates Laboratories, the Security
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* Research Division of Network Associates, Inc. under DARPA/SPAWAR
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* contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
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* research program.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The names of the authors may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/mount.h>
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#include <sys/stat.h>
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#include <ufs/ufs/ufsmount.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <grp.h>
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sysexits.h>
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#include <unistd.h>
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void usage(void);
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int
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main(int argc, char **argv)
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{
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char *dir, *cp, path[PATH_MAX];
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struct ufs_args args;
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struct group *grp;
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struct stat stbuf;
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int fd;
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if (argc != 3)
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usage();
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dir = argv[1];
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args.fspec = argv[2];
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/*
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* Check that the user running this program has permission
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* to create and remove a snapshot file from the directory
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* in which they have requested to have it made. If the
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* directory is sticky and not owned by the user, then they
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* will not be able to remove the snapshot when they are
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* done with it.
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*/
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if (strlen(args.fspec) >= PATH_MAX)
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errx(1, "pathname too long %s", args.fspec);
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cp = strrchr(args.fspec, '/');
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if (cp == NULL) {
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strlcpy(path, ".", PATH_MAX);
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} else if (cp == args.fspec) {
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strlcpy(path, "/", PATH_MAX);
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} else {
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strlcpy(path, args.fspec, cp - args.fspec + 1);
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}
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if (stat(path, &stbuf) < 0)
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err(1, "%s", path);
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if (!S_ISDIR(stbuf.st_mode))
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errx(1, "%s: Not a directory", path);
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if (access(path, W_OK) < 0)
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err(1, "Lack write permission in %s", path);
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if ((stbuf.st_mode & S_ISTXT) && stbuf.st_uid != getuid())
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errx(1, "Lack write permission in %s: Sticky bit set", path);
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/*
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* Having verified access to the directory in which the
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* snapshot is to be built, proceed with creating it.
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*/
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if ((grp = getgrnam("operator")) == NULL)
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errx(1, "Cannot retrieve operator gid");
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if (mount("ffs", dir, MNT_UPDATE | MNT_SNAPSHOT, &args) < 0)
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err(1, "Cannot create %s", args.fspec);
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if ((fd = open(args.fspec, O_RDONLY)) < 0)
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err(1, "Cannot open %s", args.fspec);
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if (fstat(fd, &stbuf) != 0)
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err(1, "Cannot stat %s", args.fspec);
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if ((stbuf.st_flags & SF_SNAPSHOT) == 0)
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errx(1, "File %s is not a snapshot", args.fspec);
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if (fchown(fd, -1, grp->gr_gid) != 0)
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err(1, "Cannot chown %s", args.fspec);
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if (fchmod(fd, S_IRUSR | S_IRGRP) != 0)
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err(1, "Cannot chmod %s", args.fspec);
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exit(EXIT_SUCCESS);
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}
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void
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usage()
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{
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fprintf(stderr, "usage: mksnap_ffs mountpoint snapshot_name\n");
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exit(EX_USAGE);
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}
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