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 <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <sysexits.h> 48 #include <unistd.h> 49 #include <grp.h> 50 #include <pwd.h> 51 52 #include "mntopts.h" 53 54 static int 55 subdir(const char *p, const char *dir) 56 { 57 int l; 58 59 l = strlen(dir); 60 if (l <= 1) 61 return (1); 62 63 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0')) 64 return (1); 65 66 return (0); 67 } 68 69 static void 70 usage(void) 71 { 72 (void)fprintf(stderr, 73 "usage: mount_unionfs [-o options] directory uniondir\n"); 74 exit(EX_USAGE); 75 } 76 77 static void 78 parse_gid(const char *s, char *buf, size_t bufsize) 79 { 80 struct group *gr; 81 char *inval; 82 83 if ((gr = getgrnam(s)) != NULL) 84 snprintf(buf, bufsize, "%d", gr->gr_gid); 85 else { 86 strtol(s, &inval, 10); 87 if (*inval != 0) { 88 errx(EX_NOUSER, "unknown group id: %s", s); 89 usage(); 90 } else { 91 strncpy(buf, s, bufsize); 92 } 93 } 94 } 95 96 static void 97 parse_uid(const char *s, char *buf, size_t bufsize) 98 { 99 struct passwd *pw; 100 char *inval; 101 102 if ((pw = getpwnam(s)) != NULL) 103 snprintf(buf, bufsize, "%d", pw->pw_uid); 104 else { 105 strtol(s, &inval, 10); 106 if (*inval != 0) { 107 errx(EX_NOUSER, "unknown user id: %s", s); 108 usage(); 109 } else { 110 strncpy(buf, s, bufsize); 111 } 112 } 113 } 114 115 int 116 main(int argc, char *argv[]) 117 { 118 struct iovec *iov; 119 int ch, iovlen; 120 char source [MAXPATHLEN], target[MAXPATHLEN], errmsg[255]; 121 char uid_str[20], gid_str[20]; 122 char fstype[] = "unionfs"; 123 char *p, *val; 124 125 iov = NULL; 126 iovlen = 0; 127 memset(errmsg, 0, sizeof(errmsg)); 128 129 while ((ch = getopt(argc, argv, "bo:")) != -1) { 130 switch (ch) { 131 case 'b': 132 printf("\n -b is deprecated. Use \"-o below\" instead\n"); 133 build_iovec(&iov, &iovlen, "below", NULL, 0); 134 break; 135 case 'o': 136 p = strchr(optarg, '='); 137 val = NULL; 138 if (p != NULL) { 139 *p = '\0'; 140 val = p + 1; 141 if (strcmp(optarg, "gid") == 0) { 142 parse_gid(val, gid_str, sizeof(gid_str)); 143 val = gid_str; 144 } 145 else if (strcmp(optarg, "uid") == 0) { 146 parse_uid(val, uid_str, sizeof(uid_str)); 147 val = uid_str; 148 } 149 } 150 build_iovec(&iov, &iovlen, optarg, val, (size_t)-1); 151 break; 152 case '?': 153 default: 154 usage(); 155 /* NOTREACHED */ 156 } 157 } 158 argc -= optind; 159 argv += optind; 160 161 if (argc != 2) 162 usage(); 163 164 /* resolve both target and source with realpath(3) */ 165 if (checkpath(argv[0], target) != 0) 166 err(EX_USAGE, "%s", target); 167 if (checkpath(argv[1], source) != 0) 168 err(EX_USAGE, "%s", source); 169 170 if (subdir(target, source) || subdir(source, target)) 171 errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths", 172 argv[0], target, argv[1], source); 173 174 build_iovec(&iov, &iovlen, "fstype", fstype, (size_t)-1); 175 build_iovec(&iov, &iovlen, "fspath", source, (size_t)-1); 176 build_iovec(&iov, &iovlen, "from", target, (size_t)-1); 177 build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg)); 178 179 if (nmount(iov, iovlen, 0)) 180 err(EX_OSERR, "%s: %s", source, errmsg); 181 exit(0); 182 } 183