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