1 /* $OpenBSD: mount_tmpfs.c,v 1.8 2022/12/04 23:50:47 cheloha 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/types.h>
35 #include <sys/mount.h>
36 #include <sys/stat.h>
37
38 #include <ctype.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <grp.h>
42 #include <mntopts.h>
43 #include <pwd.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <limits.h>
49 #include <util.h>
50
51 #include "mount_tmpfs.h"
52
53 /* --------------------------------------------------------------------- */
54
55 static const struct mntopt mopts[] = {
56 MOPT_STDOPTS,
57 MOPT_WXALLOWED,
58 MOPT_UPDATE,
59 { NULL },
60 };
61
62 /* --------------------------------------------------------------------- */
63
64 static void usage(void) __dead;
65 static uid_t a_uid(const char *);
66 static gid_t a_gid(const char *);
67 static uid_t a_gid(const char *);
68 static int a_num(const char *, const char *);
69 static mode_t a_mask(const char *);
70 static void pathadj(const char *, char *);
71
72 /* --------------------------------------------------------------------- */
73
74 void
mount_tmpfs_parseargs(int argc,char * argv[],struct tmpfs_args * args,int * mntflags,char * canon_dev,char * canon_dir)75 mount_tmpfs_parseargs(int argc, char *argv[],
76 struct tmpfs_args *args, int *mntflags,
77 char *canon_dev, char *canon_dir)
78 {
79 int gidset, modeset, uidset; /* Ought to be 'bool'. */
80 int ch;
81 gid_t gid;
82 uid_t uid;
83 mode_t mode;
84 int64_t tmpnumber;
85 struct stat sb;
86
87 /* Set default values for mount point arguments. */
88 memset(args, 0, sizeof(*args));
89 args->ta_version = TMPFS_ARGS_VERSION;
90 args->ta_size_max = 0;
91 args->ta_nodes_max = 0;
92 *mntflags = 0;
93
94 gidset = 0; gid = 0;
95 uidset = 0; uid = 0;
96 modeset = 0; mode = 0;
97
98 optind = optreset = 1;
99 while ((ch = getopt(argc, argv, "g:m:n:o:s:u:")) != -1 ) {
100 switch (ch) {
101 case 'g':
102 gid = a_gid(optarg);
103 gidset = 1;
104 break;
105
106 case 'm':
107 mode = a_mask(optarg);
108 modeset = 1;
109 break;
110
111 case 'n':
112
113 if (scan_scaled(optarg, &tmpnumber) == -1)
114 err(EXIT_FAILURE, "failed to parse nodes `%s'",
115 optarg);
116 args->ta_nodes_max = tmpnumber;
117 break;
118
119 case 'o':
120 getmntopts(optarg, mopts, mntflags);
121 break;
122
123 case 's':
124 if (scan_scaled(optarg, &tmpnumber) == -1)
125 err(EXIT_FAILURE, "failed to parse size `%s'",
126 optarg);
127 args->ta_size_max = tmpnumber;
128 break;
129
130 case 'u':
131 uid = a_uid(optarg);
132 uidset = 1;
133 break;
134
135 default:
136 usage();
137 }
138 }
139 argc -= optind;
140 argv += optind;
141
142 if (argc != 2)
143 usage();
144
145 strlcpy(canon_dev, argv[0], PATH_MAX);
146 pathadj(argv[1], canon_dir);
147
148 if (stat(canon_dir, &sb) == -1)
149 err(EXIT_FAILURE, "cannot stat `%s'", canon_dir);
150
151 args->ta_root_uid = uidset ? uid : sb.st_uid;
152 args->ta_root_gid = gidset ? gid : sb.st_gid;
153 args->ta_root_mode = modeset ? mode : sb.st_mode;
154 }
155
156 /* --------------------------------------------------------------------- */
157
158 static void
usage(void)159 usage(void)
160 {
161 extern char *__progname;
162 (void)fprintf(stderr,
163 "usage: %s [-g group] [-m mode] [-n nodes] [-o options] [-s size]\n"
164 " [-u user] tmpfs mount_point\n", __progname);
165 exit(1);
166 }
167
168 /* --------------------------------------------------------------------- */
169
170 int
mount_tmpfs(int argc,char * argv[])171 mount_tmpfs(int argc, char *argv[])
172 {
173 struct tmpfs_args args;
174 char canon_dev[PATH_MAX], canon_dir[PATH_MAX];
175 int mntflags;
176
177 mount_tmpfs_parseargs(argc, argv, &args, &mntflags,
178 canon_dev, canon_dir);
179
180 if (mount(MOUNT_TMPFS, canon_dir, mntflags, &args) == -1)
181 err(EXIT_FAILURE, "tmpfs on %s", canon_dir);
182
183 return EXIT_SUCCESS;
184 }
185
186 int
main(int argc,char * argv[])187 main(int argc, char *argv[])
188 {
189
190 /* setprogname(argv[0]); */
191 return mount_tmpfs(argc, argv);
192 }
193
194 static uid_t
a_uid(const char * s)195 a_uid(const char *s)
196 {
197 struct passwd *pw;
198
199 if ((pw = getpwnam(s)) != NULL)
200 return pw->pw_uid;
201 return a_num(s, "user");
202 }
203
204 static gid_t
a_gid(const char * s)205 a_gid(const char *s)
206 {
207 struct group *gr;
208
209 if ((gr = getgrnam(s)) != NULL)
210 return gr->gr_gid;
211 return a_num(s, "group");
212 }
213
214 static int
a_num(const char * s,const char * id_type)215 a_num(const char *s, const char *id_type)
216 {
217 int id;
218 char *ep;
219
220 id = strtol(s, &ep, 0);
221 if (*ep || s == ep || id < 0)
222 errx(1, "unknown %s id: %s", id_type, s);
223 return id;
224 }
225
226 static mode_t
a_mask(const char * s)227 a_mask(const char *s)
228 {
229 int rv;
230 char *ep;
231
232 rv = strtol(s, &ep, 8);
233 if (s == ep || *ep || rv < 0)
234 errx(1, "invalid file mode: %s", s);
235 return rv;
236 }
237
238 static void
pathadj(const char * input,char * adjusted)239 pathadj(const char *input, char *adjusted)
240 {
241
242 if (realpath(input, adjusted) == NULL)
243 err(1, "realpath %s", input);
244 if (strncmp(input, adjusted, PATH_MAX)) {
245 warnx("\"%s\" is a relative path.", input);
246 warnx("using \"%s\" instead.", adjusted);
247 }
248 }
249