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