1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2014 The FreeBSD Foundation
5 *
6 * This software was developed by Edward Tomasz Napierala under sponsorship
7 * from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 */
31
32 #include <sys/capsicum.h>
33 #include <sys/disk.h>
34 #include <sys/ioctl.h>
35 #include <sys/stat.h>
36 #include <capsicum_helpers.h>
37 #include <err.h>
38 #include <errno.h>
39 #ifdef WITH_ICONV
40 #include <iconv.h>
41 #endif
42 #include <locale.h>
43 #include <stdbool.h>
44 #include <stddef.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <vis.h>
50
51 #include "fstyp.h"
52
53 #define LABEL_LEN 256
54
55 bool show_label = false;
56
57 typedef int (*fstyp_function)(FILE *, char *, size_t);
58
59 /*
60 * The ordering of fstypes[] is not arbitrary.
61 *
62 * fstyp checks the existence of a file system header to determine the
63 * type of file system on a given device. For different file systems,
64 * these headers reside at different offsets within the device.
65 *
66 * For example, the header for an MS-DOS file system begins at offset 0,
67 * whereas a header for UFS *normally* begins at offset 64k. If a device
68 * was constructed as MS-DOS and then repurposed as UFS (via newfs), it
69 * is possible the MS-DOS header will still be intact. To prevent
70 * misidentifying the file system, it is desirable to check the header
71 * with the largest offset first (i.e., UFS before MS-DOS).
72 */
73 static struct {
74 const char *name;
75 fstyp_function function;
76 bool unmountable;
77 const char *precache_encoding;
78 } fstypes[] = {
79 /* last sector of geli device */
80 { "geli", &fstyp_geli, true, NULL },
81 /*
82 * ufs headers have four different areas, searched in this order:
83 * offsets: 64k, 8k, 0k, 256k + 8192 bytes
84 */
85 { "ufs", &fstyp_ufs, false, NULL },
86 /* offset 32768 + 512 bytes */
87 { "cd9660", &fstyp_cd9660, false, NULL },
88 /* offset 1024 + 512 bytes */
89 { "hfs+", &fstyp_hfsp, false, NULL },
90 /* offset 1024 + 512 bytes */
91 { "ext2fs", &fstyp_ext2fs, false, NULL },
92 /* offset 512 + 36 bytes */
93 { "befs", &fstyp_befs, false, NULL },
94 /* offset 0 + 40 bytes */
95 { "apfs", &fstyp_apfs, true, NULL },
96 /* offset 0 + 512 bytes (for initial signature check) */
97 { "exfat", &fstyp_exfat, false, EXFAT_ENC },
98 /* offset 0 + 1928 bytes */
99 { "hammer", &fstyp_hammer, true, NULL },
100 /* offset 0 + 65536 bytes (for initial signature check) */
101 { "hammer2", &fstyp_hammer2, true, NULL },
102 /* offset 0 + 512 bytes (for initial signature check) */
103 { "msdosfs", &fstyp_msdosfs, false, NULL },
104 /* offset 0 + 512 bytes (for initial signature check) */
105 { "ntfs", &fstyp_ntfs, false, NTFS_ENC },
106 #ifdef HAVE_ZFS
107 /* offset 0 + 256k */
108 { "zfs", &fstyp_zfs, true, NULL },
109 #endif
110 { NULL, NULL, NULL, NULL }
111 };
112
113 void *
read_buf(FILE * fp,off_t off,size_t len)114 read_buf(FILE *fp, off_t off, size_t len)
115 {
116 int error;
117 size_t nread;
118 void *buf;
119
120 error = fseek(fp, off, SEEK_SET);
121 if (error != 0) {
122 warn("cannot seek to %jd", (uintmax_t)off);
123 return (NULL);
124 }
125
126 buf = malloc(len);
127 if (buf == NULL) {
128 warn("cannot malloc %zd bytes of memory", len);
129 return (NULL);
130 }
131
132 nread = fread(buf, len, 1, fp);
133 if (nread != 1) {
134 free(buf);
135 if (feof(fp) == 0)
136 warn("fread");
137 return (NULL);
138 }
139
140 return (buf);
141 }
142
143 char *
checked_strdup(const char * s)144 checked_strdup(const char *s)
145 {
146 char *c;
147
148 c = strdup(s);
149 if (c == NULL)
150 err(1, "strdup");
151 return (c);
152 }
153
154 void
rtrim(char * label,size_t size)155 rtrim(char *label, size_t size)
156 {
157 ptrdiff_t i;
158
159 for (i = size - 1; i >= 0; i--) {
160 if (label[i] == '\0')
161 continue;
162 else if (label[i] == ' ')
163 label[i] = '\0';
164 else
165 break;
166 }
167 }
168
169 static void
usage(void)170 usage(void)
171 {
172
173 fprintf(stderr, "usage: fstyp [-l] [-s] [-u] special\n");
174 exit(1);
175 }
176
177 static void
type_check(const char * path,FILE * fp)178 type_check(const char *path, FILE *fp)
179 {
180 int error, fd;
181 off_t mediasize;
182 struct stat sb;
183
184 fd = fileno(fp);
185
186 error = fstat(fd, &sb);
187 if (error != 0)
188 err(1, "%s: fstat", path);
189
190 if (S_ISREG(sb.st_mode))
191 return;
192
193 error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
194 if (error != 0)
195 errx(1, "%s: not a disk", path);
196 }
197
198 int
main(int argc,char ** argv)199 main(int argc, char **argv)
200 {
201 int ch, error, i, nbytes;
202 bool ignore_type = false, show_unmountable = false;
203 char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
204 char *path;
205 FILE *fp;
206 fstyp_function fstyp_f;
207
208 while ((ch = getopt(argc, argv, "lsu")) != -1) {
209 switch (ch) {
210 case 'l':
211 show_label = true;
212 break;
213 case 's':
214 ignore_type = true;
215 break;
216 case 'u':
217 show_unmountable = true;
218 break;
219 default:
220 usage();
221 }
222 }
223
224 argc -= optind;
225 argv += optind;
226 if (argc != 1)
227 usage();
228
229 path = argv[0];
230
231 if (setlocale(LC_CTYPE, "") == NULL)
232 err(1, "setlocale");
233 caph_cache_catpages();
234
235 #ifdef WITH_ICONV
236 /* Cache iconv conversion data before entering capability mode. */
237 if (show_label) {
238 for (i = 0; i < (int)nitems(fstypes); i++) {
239 iconv_t cd;
240
241 if (fstypes[i].precache_encoding == NULL)
242 continue;
243 cd = iconv_open("", fstypes[i].precache_encoding);
244 if (cd == (iconv_t)-1)
245 err(1, "%s: iconv_open %s", fstypes[i].name,
246 fstypes[i].precache_encoding);
247 /* Iconv keeps a small cache of unused encodings. */
248 iconv_close(cd);
249 }
250 }
251 #endif
252
253 fp = fopen(path, "r");
254 if (fp == NULL)
255 err(1, "%s", path);
256
257 if (caph_enter() < 0)
258 err(1, "cap_enter");
259
260 if (ignore_type == false)
261 type_check(path, fp);
262
263 memset(label, '\0', sizeof(label));
264
265 for (i = 0;; i++) {
266 if (show_unmountable == false && fstypes[i].unmountable == true)
267 continue;
268 fstyp_f = fstypes[i].function;
269 if (fstyp_f == NULL)
270 break;
271
272 error = fstyp_f(fp, label, sizeof(label));
273 if (error == 0)
274 break;
275 }
276
277 if (fstypes[i].name == NULL) {
278 warnx("%s: filesystem not recognized", path);
279 return (1);
280 }
281
282 if (show_label && label[0] != '\0') {
283 /*
284 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
285 * encodes spaces.
286 */
287 nbytes = strsnvis(strvised, sizeof(strvised), label,
288 VIS_GLOB | VIS_NL, "\"'$");
289 if (nbytes == -1)
290 err(1, "strsnvis");
291
292 printf("%s %s\n", fstypes[i].name, strvised);
293 } else {
294 printf("%s\n", fstypes[i].name);
295 }
296
297 return (0);
298 }
299