xref: /freebsd/usr.sbin/fstyp/fstyp.c (revision 94cba8034ba53725c225c85e35724f0c2b13cea5)
1 /*-
2  * Copyright (c) 2014 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/capsicum.h>
35 #include <sys/disk.h>
36 #include <sys/ioctl.h>
37 #include <sys/stat.h>
38 #include <capsicum_helpers.h>
39 #include <err.h>
40 #include <errno.h>
41 #ifdef WITH_ICONV
42 #include <iconv.h>
43 #endif
44 #include <locale.h>
45 #include <stdbool.h>
46 #include <stddef.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <vis.h>
52 
53 #include "fstyp.h"
54 
55 #define	LABEL_LEN	256
56 
57 bool show_label = false;
58 
59 typedef int (*fstyp_function)(FILE *, char *, size_t);
60 
61 static struct {
62 	const char	*name;
63 	fstyp_function	function;
64 	bool		unmountable;
65 	char		*precache_encoding;
66 } fstypes[] = {
67 	{ "apfs", &fstyp_apfs, true, NULL },
68 	{ "cd9660", &fstyp_cd9660, false, NULL },
69 	{ "exfat", &fstyp_exfat, false, EXFAT_ENC },
70 	{ "ext2fs", &fstyp_ext2fs, false, NULL },
71 	{ "geli", &fstyp_geli, true, NULL },
72 	{ "hammer", &fstyp_hammer, true, NULL },
73 	{ "hammer2", &fstyp_hammer2, true, NULL },
74 	{ "hfs+", &fstyp_hfsp, false, NULL },
75 	{ "msdosfs", &fstyp_msdosfs, false, NULL },
76 	{ "ntfs", &fstyp_ntfs, false, NTFS_ENC },
77 	{ "ufs", &fstyp_ufs, false, NULL },
78 #ifdef HAVE_ZFS
79 	{ "zfs", &fstyp_zfs, true, NULL },
80 #endif
81 	{ NULL, NULL, NULL, NULL }
82 };
83 
84 void *
85 read_buf(FILE *fp, off_t off, size_t len)
86 {
87 	int error;
88 	size_t nread;
89 	void *buf;
90 
91 	error = fseek(fp, off, SEEK_SET);
92 	if (error != 0) {
93 		warn("cannot seek to %jd", (uintmax_t)off);
94 		return (NULL);
95 	}
96 
97 	buf = malloc(len);
98 	if (buf == NULL) {
99 		warn("cannot malloc %zd bytes of memory", len);
100 		return (NULL);
101 	}
102 
103 	nread = fread(buf, len, 1, fp);
104 	if (nread != 1) {
105 		free(buf);
106 		if (feof(fp) == 0)
107 			warn("fread");
108 		return (NULL);
109 	}
110 
111 	return (buf);
112 }
113 
114 char *
115 checked_strdup(const char *s)
116 {
117 	char *c;
118 
119 	c = strdup(s);
120 	if (c == NULL)
121 		err(1, "strdup");
122 	return (c);
123 }
124 
125 void
126 rtrim(char *label, size_t size)
127 {
128 	ptrdiff_t i;
129 
130 	for (i = size - 1; i >= 0; i--) {
131 		if (label[i] == '\0')
132 			continue;
133 		else if (label[i] == ' ')
134 			label[i] = '\0';
135 		else
136 			break;
137 	}
138 }
139 
140 static void
141 usage(void)
142 {
143 
144 	fprintf(stderr, "usage: fstyp [-l] [-s] [-u] special\n");
145 	exit(1);
146 }
147 
148 static void
149 type_check(const char *path, FILE *fp)
150 {
151 	int error, fd;
152 	off_t mediasize;
153 	struct stat sb;
154 
155 	fd = fileno(fp);
156 
157 	error = fstat(fd, &sb);
158 	if (error != 0)
159 		err(1, "%s: fstat", path);
160 
161 	if (S_ISREG(sb.st_mode))
162 		return;
163 
164 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
165 	if (error != 0)
166 		errx(1, "%s: not a disk", path);
167 }
168 
169 int
170 main(int argc, char **argv)
171 {
172 	int ch, error, i, nbytes;
173 	bool ignore_type = false, show_unmountable = false;
174 	char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
175 	char *path;
176 	FILE *fp;
177 	fstyp_function fstyp_f;
178 
179 	while ((ch = getopt(argc, argv, "lsu")) != -1) {
180 		switch (ch) {
181 		case 'l':
182 			show_label = true;
183 			break;
184 		case 's':
185 			ignore_type = true;
186 			break;
187 		case 'u':
188 			show_unmountable = true;
189 			break;
190 		default:
191 			usage();
192 		}
193 	}
194 
195 	argc -= optind;
196 	argv += optind;
197 	if (argc != 1)
198 		usage();
199 
200 	path = argv[0];
201 
202 	if (setlocale(LC_CTYPE, "") == NULL)
203 		err(1, "setlocale");
204 	caph_cache_catpages();
205 
206 #ifdef WITH_ICONV
207 	/* Cache iconv conversion data before entering capability mode. */
208 	if (show_label) {
209 		for (i = 0; i < nitems(fstypes); i++) {
210 			iconv_t cd;
211 
212 			if (fstypes[i].precache_encoding == NULL)
213 				continue;
214 			cd = iconv_open("", fstypes[i].precache_encoding);
215 			if (cd == (iconv_t)-1)
216 				err(1, "%s: iconv_open %s", fstypes[i].name,
217 				    fstypes[i].precache_encoding);
218 			/* Iconv keeps a small cache of unused encodings. */
219 			iconv_close(cd);
220 		}
221 	}
222 #endif
223 
224 	fp = fopen(path, "r");
225 	if (fp == NULL)
226 		err(1, "%s", path);
227 
228 	if (caph_enter() < 0)
229 		err(1, "cap_enter");
230 
231 	if (ignore_type == false)
232 		type_check(path, fp);
233 
234 	memset(label, '\0', sizeof(label));
235 
236 	for (i = 0;; i++) {
237 		if (show_unmountable == false && fstypes[i].unmountable == true)
238 			continue;
239 		fstyp_f = fstypes[i].function;
240 		if (fstyp_f == NULL)
241 			break;
242 
243 		error = fstyp_f(fp, label, sizeof(label));
244 		if (error == 0)
245 			break;
246 	}
247 
248 	if (fstypes[i].name == NULL) {
249 		warnx("%s: filesystem not recognized", path);
250 		return (1);
251 	}
252 
253 	if (show_label && label[0] != '\0') {
254 		/*
255 		 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
256 		 *      encodes spaces.
257 		 */
258 		nbytes = strsnvis(strvised, sizeof(strvised), label,
259 		    VIS_GLOB | VIS_NL, "\"'$");
260 		if (nbytes == -1)
261 			err(1, "strsnvis");
262 
263 		printf("%s %s\n", fstypes[i].name, strvised);
264 	} else {
265 		printf("%s\n", fstypes[i].name);
266 	}
267 
268 	return (0);
269 }
270