xref: /openbsd/sbin/mount_tmpfs/mount_tmpfs.c (revision 91f110e0)
1 /*	$OpenBSD: mount_tmpfs.c,v 1.4 2014/01/21 21:58:27 jsg Exp $	*/
2 /*	$NetBSD: mount_tmpfs.c,v 1.24 2008/08/05 20:57:45 pooka Exp $	*/
3 
4 /*
5  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
10  * 2005 program.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 #if 0
36 __RCSID("$NetBSD: mount_tmpfs.c,v 1.24 2008/08/05 20:57:45 pooka Exp $");
37 #endif
38 
39 #include <sys/param.h>
40 #include <sys/mount.h>
41 #include <sys/stat.h>
42 
43 #include <ctype.h>
44 #include <err.h>
45 #include <errno.h>
46 #include <grp.h>
47 #include <mntopts.h>
48 #include <pwd.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <util.h>
54 
55 #include "mount_tmpfs.h"
56 
57 /* --------------------------------------------------------------------- */
58 
59 static const struct mntopt mopts[] = {
60 	MOPT_STDOPTS,
61 	MOPT_UPDATE,
62 	{ NULL },
63 };
64 
65 /* --------------------------------------------------------------------- */
66 
67 static void	usage(void) __dead;
68 static uid_t	a_uid(const char *);
69 static gid_t	a_gid(const char *);
70 static uid_t	a_gid(const char *);
71 static int	a_num(const char *, const char *);
72 static mode_t	a_mask(const char *);
73 static void	pathadj(const char *, char *);
74 
75 /* --------------------------------------------------------------------- */
76 
77 void
78 mount_tmpfs_parseargs(int argc, char *argv[],
79 	struct tmpfs_args *args, int *mntflags,
80 	char *canon_dev, char *canon_dir)
81 {
82 	int gidset, modeset, uidset; /* Ought to be 'bool'. */
83 	int ch;
84 	gid_t gid;
85 	uid_t uid;
86 	mode_t mode;
87 	int64_t tmpnumber;
88 	struct stat sb;
89 
90 	/* Set default values for mount point arguments. */
91 	memset(args, 0, sizeof(*args));
92 	args->ta_version = TMPFS_ARGS_VERSION;
93 	args->ta_size_max = 0;
94 	args->ta_nodes_max = 0;
95 	*mntflags = 0;
96 
97 	gidset = 0; gid = 0;
98 	uidset = 0; uid = 0;
99 	modeset = 0; mode = 0;
100 
101 	optind = optreset = 1;
102 	while ((ch = getopt(argc, argv, "g:m:n:o:s:u:")) != -1 ) {
103 		switch (ch) {
104 		case 'g':
105 			gid = a_gid(optarg);
106 			gidset = 1;
107 			break;
108 
109 		case 'm':
110 			mode = a_mask(optarg);
111 			modeset = 1;
112 			break;
113 
114 		case 'n':
115 
116 			if (scan_scaled(optarg, &tmpnumber) == -1)
117 				err(EXIT_FAILURE, "failed to parse nodes `%s'",
118 				    optarg);
119 			args->ta_nodes_max = tmpnumber;
120 			break;
121 
122 		case 'o':
123 			getmntopts(optarg, mopts, mntflags);
124 			break;
125 
126 		case 's':
127 			if (scan_scaled(optarg, &tmpnumber) == -1)
128 				err(EXIT_FAILURE, "failed to parse size `%s'",
129 				    optarg);
130 			args->ta_size_max = tmpnumber;
131 			break;
132 
133 		case 'u':
134 			uid = a_uid(optarg);
135 			uidset = 1;
136 			break;
137 
138 		case '?':
139 		default:
140 			usage();
141 		}
142 	}
143 	argc -= optind;
144 	argv += optind;
145 
146 	if (argc != 2)
147 		usage();
148 
149 	strlcpy(canon_dev, argv[0], MAXPATHLEN);
150 	pathadj(argv[1], canon_dir);
151 
152 	if (stat(canon_dir, &sb) == -1)
153 		err(EXIT_FAILURE, "cannot stat `%s'", canon_dir);
154 
155 	args->ta_root_uid = uidset ? uid : sb.st_uid;
156 	args->ta_root_gid = gidset ? gid : sb.st_gid;
157 	args->ta_root_mode = modeset ? mode : sb.st_mode;
158 }
159 
160 /* --------------------------------------------------------------------- */
161 
162 static void
163 usage(void)
164 {
165 	extern char *__progname;
166 	(void)fprintf(stderr,
167 	    "usage: %s [-g group] [-m mode] [-n nodes] [-o options] [-s size]\n"
168 	    "           [-u user] tmpfs mount_point\n", __progname);
169 	exit(1);
170 }
171 
172 /* --------------------------------------------------------------------- */
173 
174 int
175 mount_tmpfs(int argc, char *argv[])
176 {
177 	struct tmpfs_args args;
178 	char canon_dev[MAXPATHLEN], canon_dir[MAXPATHLEN];
179 	int mntflags;
180 
181 	mount_tmpfs_parseargs(argc, argv, &args, &mntflags,
182 	    canon_dev, canon_dir);
183 
184 	if (mount(MOUNT_TMPFS, canon_dir, mntflags, &args) == -1)
185 		err(EXIT_FAILURE, "tmpfs on %s", canon_dir);
186 
187 	return EXIT_SUCCESS;
188 }
189 
190 int
191 main(int argc, char *argv[])
192 {
193 
194 	/* setprogname(argv[0]); */
195 	return mount_tmpfs(argc, argv);
196 }
197 
198 static uid_t
199 a_uid(const char *s)
200 {
201 	struct passwd *pw;
202 
203 	if ((pw = getpwnam(s)) != NULL)
204 		return pw->pw_uid;
205 	return a_num(s, "user");
206 }
207 
208 static gid_t
209 a_gid(const char *s)
210 {
211 	struct group *gr;
212 
213 	if ((gr = getgrnam(s)) != NULL)
214 		return gr->gr_gid;
215 	return a_num(s, "group");
216 }
217 
218 static int
219 a_num(const char *s, const char *id_type)
220 {
221 	int id;
222 	char *ep;
223 
224 	id = strtol(s, &ep, 0);
225 	if (*ep || s == ep || id < 0)
226 		errx(1, "unknown %s id: %s", id_type, s);
227 	return id;
228 }
229 
230 static mode_t
231 a_mask(const char *s)
232 {
233 	int rv;
234 	char *ep;
235 
236 	rv = strtol(s, &ep, 8);
237 	if (s == ep || *ep || rv < 0)
238 		errx(1, "invalid file mode: %s", s);
239 	return rv;
240 }
241 
242 static void
243 pathadj(const char *input, char *adjusted)
244 {
245 
246 	if (realpath(input, adjusted) == NULL)
247 		warn("Warning: realpath %s", input);
248 	if (strncmp(input, adjusted, MAXPATHLEN)) {
249 		warnx("\"%s\" is a non-resolved or relative path.", input);
250 		warnx("using \"%s\" instead.", adjusted);
251 	}
252 }
253