1
2 /* $NetBSD: mount_tmpfs.c,v 1.29 2016/02/21 22:51:30 christos 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 #ifndef lint
36 __RCSID("$NetBSD: mount_tmpfs.c,v 1.29 2016/02/21 22:51:30 christos Exp $");
37 #endif /* not lint */
38
39 #include <sys/param.h>
40 #include <sys/mount.h>
41 #include <sys/stat.h>
42 #include <sys/sysctl.h>
43
44 #include <fs/tmpfs/tmpfs_args.h>
45
46 #include <ctype.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <grp.h>
50 #include <mntopts.h>
51 #include <pwd.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56
57 #include "mountprog.h"
58 #include "mount_tmpfs.h"
59
60 /* --------------------------------------------------------------------- */
61
62 static const struct mntopt mopts[] = {
63 MOPT_UPDATE,
64 MOPT_STDOPTS,
65 MOPT_GETARGS,
66 MOPT_NOATIME,
67 MOPT_RELATIME,
68 MOPT_NULL,
69 };
70
71 /* --------------------------------------------------------------------- */
72
73 static void usage(void) __dead;
74 static int64_t ram_fract(const char *arg);
75 static int64_t ram_percent(const char *arg);
76 static int64_t ram_factor(float f);
77
78 /* --------------------------------------------------------------------- */
79
80 /* return f * available system ram */
81 static int64_t
ram_factor(float f)82 ram_factor(float f)
83 {
84 uint64_t ram;
85 size_t len;
86
87 len = sizeof(ram);
88 if (sysctlbyname("hw.physmem64", &ram, &len, NULL, 0))
89 err(EXIT_FAILURE, "can't get \"hw.physmem64\"");
90
91 return (int64_t)((float)ram * f);
92 }
93
94 /* return fraction of available ram given by arg */
95 static int64_t
ram_fract(const char * arg)96 ram_fract(const char *arg)
97 {
98 char *endp;
99 float f;
100
101 f = strtof(arg, &endp);
102 if (endp && *endp != 0)
103 errx(EXIT_FAILURE, "syntax error in ram fraction: ram/%s"
104 " at %s", arg, endp);
105 if (f <= 0.0f)
106 errx(EXIT_FAILURE, "ram fraction must be a positive number:"
107 " ram/%s", arg);
108
109 return ram_factor(1.0f/f);
110 }
111
112 /* --------------------------------------------------------------------- */
113
114 /* return percentage of available ram given by arg */
115 static int64_t
ram_percent(const char * arg)116 ram_percent(const char *arg)
117 {
118 char *endp;
119 float f;
120
121 f = strtof(arg, &endp);
122 if (endp && *endp != 0)
123 errx(EXIT_FAILURE, "syntax error in ram percentage: ram%%%s"
124 " at %s", arg, endp);
125 if (f <= 0.0f || f >= 100.0f)
126 errx(EXIT_FAILURE, "ram percentage must be a between 0 and 100"
127 " ram%%%s", arg);
128
129 return ram_factor(f/100.0f);
130 }
131
132 /* --------------------------------------------------------------------- */
133
134 void
mount_tmpfs_parseargs(int argc,char * argv[],struct tmpfs_args * args,int * mntflags,char * canon_dev,char * canon_dir)135 mount_tmpfs_parseargs(int argc, char *argv[],
136 struct tmpfs_args *args, int *mntflags,
137 char *canon_dev, char *canon_dir)
138 {
139 int gidset, modeset, uidset; /* Ought to be 'bool'. */
140 int ch;
141 gid_t gid;
142 uid_t uid;
143 mode_t mode;
144 int64_t tmpnumber;
145 mntoptparse_t mp;
146 struct stat sb;
147
148 /* Set default values for mount point arguments. */
149 memset(args, 0, sizeof(*args));
150 args->ta_version = TMPFS_ARGS_VERSION;
151 args->ta_size_max = 0;
152 args->ta_nodes_max = 0;
153 *mntflags = 0;
154
155 gidset = 0; gid = 0;
156 uidset = 0; uid = 0;
157 modeset = 0; mode = 0;
158
159 optind = optreset = 1;
160 while ((ch = getopt(argc, argv, "g:m:n:o:s:u:")) != -1 ) {
161 switch (ch) {
162 case 'g':
163 gid = a_gid(optarg);
164 gidset = 1;
165 break;
166
167 case 'm':
168 mode = a_mask(optarg);
169 modeset = 1;
170 break;
171
172 case 'n':
173 if (dehumanize_number(optarg, &tmpnumber) == -1)
174 err(EXIT_FAILURE, "failed to parse nodes `%s'",
175 optarg);
176 args->ta_nodes_max = tmpnumber;
177 break;
178
179 case 'o':
180 mp = getmntopts(optarg, mopts, mntflags, 0);
181 if (mp == NULL)
182 err(EXIT_FAILURE, "getmntopts");
183 freemntopts(mp);
184 break;
185
186 case 's':
187 if (strncmp(optarg, "ram/", 4) == 0)
188 tmpnumber = ram_fract(optarg+4);
189 else if (strncmp(optarg, "ram%", 4) == 0)
190 tmpnumber = ram_percent(optarg+4);
191 else if (dehumanize_number(optarg, &tmpnumber) == -1)
192 err(EXIT_FAILURE, "failed to parse size `%s'",
193 optarg);
194 args->ta_size_max = tmpnumber;
195 break;
196
197 case 'u':
198 uid = a_uid(optarg);
199 uidset = 1;
200 break;
201
202 case '?':
203 default:
204 usage();
205 }
206 }
207 argc -= optind;
208 argv += optind;
209
210 if (argc != 2)
211 usage();
212
213 strlcpy(canon_dev, argv[0], MAXPATHLEN);
214 pathadj(argv[1], canon_dir);
215
216 if (stat(canon_dir, &sb) == -1)
217 err(EXIT_FAILURE, "cannot stat `%s'", canon_dir);
218
219 args->ta_root_uid = uidset ? uid : sb.st_uid;
220 args->ta_root_gid = gidset ? gid : sb.st_gid;
221 args->ta_root_mode = modeset ? mode : sb.st_mode;
222 }
223
224 /* --------------------------------------------------------------------- */
225
226 static void
usage(void)227 usage(void)
228 {
229 (void)fprintf(stderr,
230 "usage: %s [-g group] [-m mode] [-n nodes] [-o options] [-s size]\n"
231 " [-u user] tmpfs mount_point\n", getprogname());
232 exit(1);
233 }
234
235 /* --------------------------------------------------------------------- */
236
237 int
mount_tmpfs(int argc,char * argv[])238 mount_tmpfs(int argc, char *argv[])
239 {
240 struct tmpfs_args args;
241 char canon_dev[MAXPATHLEN], canon_dir[MAXPATHLEN];
242 int mntflags;
243
244 mount_tmpfs_parseargs(argc, argv, &args, &mntflags,
245 canon_dev, canon_dir);
246
247 if (mount(MOUNT_TMPFS, canon_dir, mntflags, &args, sizeof args) == -1)
248 err(EXIT_FAILURE, "tmpfs on %s", canon_dir);
249
250 if (mntflags & MNT_GETARGS) {
251 struct passwd *pw;
252 struct group *gr;
253
254 (void)printf("version=%d, ", args.ta_version);
255 (void)printf("size_max=%" PRIuMAX ", ",
256 (uintmax_t)args.ta_size_max);
257 (void)printf("nodes_max=%" PRIuMAX ", ",
258 (uintmax_t)args.ta_nodes_max);
259
260 pw = getpwuid(args.ta_root_uid);
261 if (pw == NULL)
262 (void)printf("root_uid=%" PRIuMAX ", ",
263 (uintmax_t)args.ta_root_uid);
264 else
265 (void)printf("root_uid=%s, ", pw->pw_name);
266
267 gr = getgrgid(args.ta_root_gid);
268 if (gr == NULL)
269 (void)printf("root_gid=%" PRIuMAX ", ",
270 (uintmax_t)args.ta_root_gid);
271 else
272 (void)printf("root_gid=%s, ", gr->gr_name);
273
274 (void)printf("root_mode=%o\n", args.ta_root_mode);
275 }
276
277 return EXIT_SUCCESS;
278 }
279
280 #ifndef MOUNT_NOMAIN
281 int
main(int argc,char * argv[])282 main(int argc, char *argv[])
283 {
284
285 setprogname(argv[0]);
286 return mount_tmpfs(argc, argv);
287 }
288 #endif
289