1 /* 2 * Copyright (c) 2003 Networks Associates Technology, Inc. 3 * All rights reserved. 4 * 5 * This software was developed for the FreeBSD Project by Marshall 6 * Kirk McKusick and Network Associates Laboratories, the Security 7 * Research Division of Network Associates, Inc. under DARPA/SPAWAR 8 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS 9 * research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $FreeBSD$ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/mount.h> 40 #include <sys/stat.h> 41 #include <ufs/ufs/ufsmount.h> 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <grp.h> 46 #include <limits.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <sysexits.h> 51 #include <unistd.h> 52 53 void usage(void); 54 55 int 56 main(int argc, char **argv) 57 { 58 char *dir, *cp, path[PATH_MAX]; 59 struct statfs stfsbuf; 60 struct ufs_args args; 61 struct group *grp; 62 struct stat stbuf; 63 int fd; 64 65 if (argc != 3) 66 usage(); 67 68 dir = argv[1]; 69 args.fspec = argv[2]; 70 71 /* 72 * Check that the user running this program has permission 73 * to create and remove a snapshot file from the directory 74 * in which they have requested to have it made. If the 75 * directory is sticky and not owned by the user, then they 76 * will not be able to remove the snapshot when they are 77 * done with it. 78 */ 79 if (strlen(args.fspec) >= PATH_MAX) 80 errx(1, "pathname too long %s", args.fspec); 81 cp = strrchr(args.fspec, '/'); 82 if (cp == NULL) { 83 strlcpy(path, ".", PATH_MAX); 84 } else if (cp == args.fspec) { 85 strlcpy(path, "/", PATH_MAX); 86 } else { 87 strlcpy(path, args.fspec, cp - args.fspec + 1); 88 } 89 if (statfs(path, &stfsbuf) < 0) 90 err(1, "%s", path); 91 if (stat(path, &stbuf) < 0) 92 err(1, "%s", path); 93 if (!S_ISDIR(stbuf.st_mode)) 94 errx(1, "%s: Not a directory", path); 95 if (access(path, W_OK) < 0) 96 err(1, "Lack write permission in %s", path); 97 if ((stbuf.st_mode & S_ISTXT) && stbuf.st_uid != getuid()) 98 errx(1, "Lack write permission in %s: Sticky bit set", path); 99 100 /* 101 * Having verified access to the directory in which the 102 * snapshot is to be built, proceed with creating it. 103 */ 104 if ((grp = getgrnam("operator")) == NULL) 105 errx(1, "Cannot retrieve operator gid"); 106 if (mount("ffs", dir, MNT_UPDATE | MNT_SNAPSHOT | stfsbuf.f_flags, 107 &args) < 0) 108 err(1, "Cannot create %s", args.fspec); 109 if ((fd = open(args.fspec, O_RDONLY)) < 0) 110 err(1, "Cannot open %s", args.fspec); 111 if (fstat(fd, &stbuf) != 0) 112 err(1, "Cannot stat %s", args.fspec); 113 if ((stbuf.st_flags & SF_SNAPSHOT) == 0) 114 errx(1, "File %s is not a snapshot", args.fspec); 115 if (fchown(fd, -1, grp->gr_gid) != 0) 116 err(1, "Cannot chown %s", args.fspec); 117 if (fchmod(fd, S_IRUSR | S_IRGRP) != 0) 118 err(1, "Cannot chmod %s", args.fspec); 119 120 exit(EXIT_SUCCESS); 121 } 122 123 void 124 usage() 125 { 126 127 fprintf(stderr, "usage: mksnap_ffs mountpoint snapshot_name\n"); 128 exit(EX_USAGE); 129 } 130