1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992, 1993, 1994 5 * The Regents of the University of California. 6 * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc. 7 * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org> 8 * All rights reserved. 9 * 10 * This code is derived from software donated to Berkeley by 11 * Jan-Simon Pendry. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 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. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 35 * SUCH DAMAGE. 36 */ 37 38 #include <sys/param.h> 39 #include <sys/mount.h> 40 #include <sys/uio.h> 41 #include <sys/errno.h> 42 43 #include <err.h> 44 #include <mntopts.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <sysexits.h> 49 #include <unistd.h> 50 #include <grp.h> 51 #include <pwd.h> 52 53 static int 54 subdir(const char *p, const char *dir) 55 { 56 int l; 57 58 l = strlen(dir); 59 if (l <= 1) 60 return (1); 61 62 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 63 return (1); 64 65 return (0); 66 } 67 68 static void 69 usage(void) 70 { 71 (void)fprintf(stderr, 72 "usage: mount_unionfs [-o options] directory uniondir\n"); 73 exit(EX_USAGE); 74 } 75 76 static void 77 parse_gid(const char *s, char *buf, size_t bufsize) 78 { 79 struct group *gr; 80 char *inval; 81 82 if ((gr = getgrnam(s)) != NULL) 83 snprintf(buf, bufsize, "%d", gr->gr_gid); 84 else { 85 strtol(s, &inval, 10); 86 if (*inval != 0) { 87 errx(EX_NOUSER, "unknown group id: %s", s); 88 usage(); 89 } else { 90 strncpy(buf, s, bufsize); 91 } 92 } 93 } 94 95 static void 96 parse_uid(const char *s, char *buf, size_t bufsize) 97 { 98 struct passwd *pw; 99 char *inval; 100 101 if ((pw = getpwnam(s)) != NULL) 102 snprintf(buf, bufsize, "%d", pw->pw_uid); 103 else { 104 strtol(s, &inval, 10); 105 if (*inval != 0) { 106 errx(EX_NOUSER, "unknown user id: %s", s); 107 usage(); 108 } else { 109 strncpy(buf, s, bufsize); 110 } 111 } 112 } 113 114 int 115 main(int argc, char *argv[]) 116 { 117 struct iovec *iov; 118 int ch, iovlen; 119 char source [MAXPATHLEN], target[MAXPATHLEN], errmsg[255]; 120 char uid_str[20], gid_str[20]; 121 char fstype[] = "unionfs"; 122 char *p, *val; 123 124 iov = NULL; 125 iovlen = 0; 126 memset(errmsg, 0, sizeof(errmsg)); 127 128 while ((ch = getopt(argc, argv, "bo:")) != -1) { 129 switch (ch) { 130 case 'b': 131 printf("\n -b is deprecated. Use \"-o below\" instead\n"); 132 build_iovec(&iov, &iovlen, "below", NULL, 0); 133 break; 134 case 'o': 135 p = strchr(optarg, '='); 136 val = NULL; 137 if (p != NULL) { 138 *p = '\0'; 139 val = p + 1; 140 if (strcmp(optarg, "gid") == 0) { 141 parse_gid(val, gid_str, sizeof(gid_str)); 142 val = gid_str; 143 } 144 else if (strcmp(optarg, "uid") == 0) { 145 parse_uid(val, uid_str, sizeof(uid_str)); 146 val = uid_str; 147 } 148 } 149 build_iovec(&iov, &iovlen, optarg, val, (size_t)-1); 150 break; 151 case '?': 152 default: 153 usage(); 154 /* NOTREACHED */ 155 } 156 } 157 argc -= optind; 158 argv += optind; 159 160 if (argc != 2) 161 usage(); 162 163 /* resolve both target and source with realpath(3) */ 164 if (checkpath(argv[0], target) != 0) 165 err(EX_USAGE, "%s", target); 166 if (checkpath(argv[1], source) != 0) 167 err(EX_USAGE, "%s", source); 168 169 if (subdir(target, source) || subdir(source, target)) 170 errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths", 171 argv[0], target, argv[1], source); 172 173 build_iovec(&iov, &iovlen, "fstype", fstype, (size_t)-1); 174 build_iovec(&iov, &iovlen, "fspath", source, (size_t)-1); 175 build_iovec(&iov, &iovlen, "from", target, (size_t)-1); 176 build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg)); 177 178 if (nmount(iov, iovlen, 0)) 179 err(EX_OSERR, "%s: %s", source, errmsg); 180 exit(0); 181 } 182