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
subdir(const char * p,const char * dir)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
usage(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
parse_gid(const char * s,char * buf,size_t bufsize)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
parse_uid(const char * s,char * buf,size_t bufsize)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
main(int argc,char * argv[])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