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 <[email protected]>, ONGS Inc.
7 * Copyright (c) 2006 Daichi Goto <[email protected]>
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 #ifndef lint
39 static const char copyright[] =
40 "@(#) Copyright (c) 1992, 1993, 1994\n\
41 The Regents of the University of California. All rights reserved.\n";
42 #endif /* not lint */
43
44 #ifndef lint
45 #if 0
46 static char sccsid[] = "@(#)mount_union.c 8.5 (Berkeley) 3/27/94";
47 #else
48 static const char rcsid[] =
49 "$FreeBSD$";
50 #endif
51 #endif /* not lint */
52
53 #include <sys/param.h>
54 #include <sys/mount.h>
55 #include <sys/uio.h>
56 #include <sys/errno.h>
57
58 #include <err.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <sysexits.h>
63 #include <unistd.h>
64 #include <grp.h>
65 #include <pwd.h>
66
67 #include "mntopts.h"
68
69 static int
subdir(const char * p,const char * dir)70 subdir(const char *p, const char *dir)
71 {
72 int l;
73
74 l = strlen(dir);
75 if (l <= 1)
76 return (1);
77
78 if ((strncmp(p, dir, l) == 0) && (p[l] == '/' || p[l] == '\0'))
79 return (1);
80
81 return (0);
82 }
83
84 static void
usage(void)85 usage(void)
86 {
87 (void)fprintf(stderr,
88 "usage: mount_unionfs [-o options] directory uniondir\n");
89 exit(EX_USAGE);
90 }
91
92 static void
parse_gid(const char * s,char * buf,size_t bufsize)93 parse_gid(const char *s, char *buf, size_t bufsize)
94 {
95 struct group *gr;
96 char *inval;
97
98 if ((gr = getgrnam(s)) != NULL)
99 snprintf(buf, bufsize, "%d", gr->gr_gid);
100 else {
101 strtol(s, &inval, 10);
102 if (*inval != 0) {
103 errx(EX_NOUSER, "unknown group id: %s", s);
104 usage();
105 } else {
106 strncpy(buf, s, bufsize);
107 }
108 }
109 }
110
111 static void
parse_uid(const char * s,char * buf,size_t bufsize)112 parse_uid(const char *s, char *buf, size_t bufsize)
113 {
114 struct passwd *pw;
115 char *inval;
116
117 if ((pw = getpwnam(s)) != NULL)
118 snprintf(buf, bufsize, "%d", pw->pw_uid);
119 else {
120 strtol(s, &inval, 10);
121 if (*inval != 0) {
122 errx(EX_NOUSER, "unknown user id: %s", s);
123 usage();
124 } else {
125 strncpy(buf, s, bufsize);
126 }
127 }
128 }
129
130 int
main(int argc,char * argv[])131 main(int argc, char *argv[])
132 {
133 struct iovec *iov;
134 int ch, iovlen;
135 char source [MAXPATHLEN], target[MAXPATHLEN], errmsg[255];
136 char uid_str[20], gid_str[20];
137 char fstype[] = "unionfs";
138 char *p, *val;
139
140 iov = NULL;
141 iovlen = 0;
142 memset(errmsg, 0, sizeof(errmsg));
143
144 while ((ch = getopt(argc, argv, "bo:")) != -1) {
145 switch (ch) {
146 case 'b':
147 printf("\n -b is deprecated. Use \"-o below\" instead\n");
148 build_iovec(&iov, &iovlen, "below", NULL, 0);
149 break;
150 case 'o':
151 p = strchr(optarg, '=');
152 val = NULL;
153 if (p != NULL) {
154 *p = '\0';
155 val = p + 1;
156 if (strcmp(optarg, "gid") == 0) {
157 parse_gid(val, gid_str, sizeof(gid_str));
158 val = gid_str;
159 }
160 else if (strcmp(optarg, "uid") == 0) {
161 parse_uid(val, uid_str, sizeof(uid_str));
162 val = uid_str;
163 }
164 }
165 build_iovec(&iov, &iovlen, optarg, val, (size_t)-1);
166 break;
167 case '?':
168 default:
169 usage();
170 /* NOTREACHED */
171 }
172 }
173 argc -= optind;
174 argv += optind;
175
176 if (argc != 2)
177 usage();
178
179 /* resolve both target and source with realpath(3) */
180 if (checkpath(argv[0], target) != 0)
181 err(EX_USAGE, "%s", target);
182 if (checkpath(argv[1], source) != 0)
183 err(EX_USAGE, "%s", source);
184
185 if (subdir(target, source) || subdir(source, target))
186 errx(EX_USAGE, "%s (%s) and %s (%s) are not distinct paths",
187 argv[0], target, argv[1], source);
188
189 build_iovec(&iov, &iovlen, "fstype", fstype, (size_t)-1);
190 build_iovec(&iov, &iovlen, "fspath", source, (size_t)-1);
191 build_iovec(&iov, &iovlen, "from", target, (size_t)-1);
192 build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
193
194 if (nmount(iov, iovlen, 0))
195 err(EX_OSERR, "%s: %s", source, errmsg);
196 exit(0);
197 }
198