xref: /freebsd/usr.sbin/fstyp/fstyp.c (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
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/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/capsicum.h>
34 #include <sys/disk.h>
35 #include <sys/ioctl.h>
36 #include <sys/stat.h>
37 #include <capsicum_helpers.h>
38 #include <err.h>
39 #include <errno.h>
40 #ifdef WITH_ICONV
41 #include <iconv.h>
42 #endif
43 #include <locale.h>
44 #include <stdbool.h>
45 #include <stddef.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <vis.h>
51 
52 #include "fstyp.h"
53 
54 #define	LABEL_LEN	256
55 
56 bool show_label = false;
57 
58 typedef int (*fstyp_function)(FILE *, char *, size_t);
59 
60 static struct {
61 	const char	*name;
62 	fstyp_function	function;
63 	bool		unmountable;
64 	char		*precache_encoding;
65 } fstypes[] = {
66 	{ "apfs", &fstyp_apfs, true, NULL },
67 	{ "cd9660", &fstyp_cd9660, false, NULL },
68 	{ "exfat", &fstyp_exfat, false, EXFAT_ENC },
69 	{ "ext2fs", &fstyp_ext2fs, false, NULL },
70 	{ "geli", &fstyp_geli, true, NULL },
71 	{ "hammer", &fstyp_hammer, true, NULL },
72 	{ "hammer2", &fstyp_hammer2, true, NULL },
73 	{ "hfs+", &fstyp_hfsp, false, NULL },
74 	{ "msdosfs", &fstyp_msdosfs, false, NULL },
75 	{ "ntfs", &fstyp_ntfs, false, NTFS_ENC },
76 	{ "ufs", &fstyp_ufs, false, NULL },
77 #ifdef HAVE_ZFS
78 	{ "zfs", &fstyp_zfs, true, NULL },
79 #endif
80 	{ NULL, NULL, NULL, NULL }
81 };
82 
83 void *
84 read_buf(FILE *fp, off_t off, size_t len)
85 {
86 	int error;
87 	size_t nread;
88 	void *buf;
89 
90 	error = fseek(fp, off, SEEK_SET);
91 	if (error != 0) {
92 		warn("cannot seek to %jd", (uintmax_t)off);
93 		return (NULL);
94 	}
95 
96 	buf = malloc(len);
97 	if (buf == NULL) {
98 		warn("cannot malloc %zd bytes of memory", len);
99 		return (NULL);
100 	}
101 
102 	nread = fread(buf, len, 1, fp);
103 	if (nread != 1) {
104 		free(buf);
105 		if (feof(fp) == 0)
106 			warn("fread");
107 		return (NULL);
108 	}
109 
110 	return (buf);
111 }
112 
113 char *
114 checked_strdup(const char *s)
115 {
116 	char *c;
117 
118 	c = strdup(s);
119 	if (c == NULL)
120 		err(1, "strdup");
121 	return (c);
122 }
123 
124 void
125 rtrim(char *label, size_t size)
126 {
127 	ptrdiff_t i;
128 
129 	for (i = size - 1; i >= 0; i--) {
130 		if (label[i] == '\0')
131 			continue;
132 		else if (label[i] == ' ')
133 			label[i] = '\0';
134 		else
135 			break;
136 	}
137 }
138 
139 static void
140 usage(void)
141 {
142 
143 	fprintf(stderr, "usage: fstyp [-l] [-s] [-u] special\n");
144 	exit(1);
145 }
146 
147 static void
148 type_check(const char *path, FILE *fp)
149 {
150 	int error, fd;
151 	off_t mediasize;
152 	struct stat sb;
153 
154 	fd = fileno(fp);
155 
156 	error = fstat(fd, &sb);
157 	if (error != 0)
158 		err(1, "%s: fstat", path);
159 
160 	if (S_ISREG(sb.st_mode))
161 		return;
162 
163 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
164 	if (error != 0)
165 		errx(1, "%s: not a disk", path);
166 }
167 
168 int
169 main(int argc, char **argv)
170 {
171 	int ch, error, i, nbytes;
172 	bool ignore_type = false, show_unmountable = false;
173 	char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
174 	char *path;
175 	FILE *fp;
176 	fstyp_function fstyp_f;
177 
178 	while ((ch = getopt(argc, argv, "lsu")) != -1) {
179 		switch (ch) {
180 		case 'l':
181 			show_label = true;
182 			break;
183 		case 's':
184 			ignore_type = true;
185 			break;
186 		case 'u':
187 			show_unmountable = true;
188 			break;
189 		default:
190 			usage();
191 		}
192 	}
193 
194 	argc -= optind;
195 	argv += optind;
196 	if (argc != 1)
197 		usage();
198 
199 	path = argv[0];
200 
201 	if (setlocale(LC_CTYPE, "") == NULL)
202 		err(1, "setlocale");
203 	caph_cache_catpages();
204 
205 #ifdef WITH_ICONV
206 	/* Cache iconv conversion data before entering capability mode. */
207 	if (show_label) {
208 		for (i = 0; i < nitems(fstypes); i++) {
209 			iconv_t cd;
210 
211 			if (fstypes[i].precache_encoding == NULL)
212 				continue;
213 			cd = iconv_open("", fstypes[i].precache_encoding);
214 			if (cd == (iconv_t)-1)
215 				err(1, "%s: iconv_open %s", fstypes[i].name,
216 				    fstypes[i].precache_encoding);
217 			/* Iconv keeps a small cache of unused encodings. */
218 			iconv_close(cd);
219 		}
220 	}
221 #endif
222 
223 	fp = fopen(path, "r");
224 	if (fp == NULL)
225 		err(1, "%s", path);
226 
227 	if (caph_enter() < 0)
228 		err(1, "cap_enter");
229 
230 	if (ignore_type == false)
231 		type_check(path, fp);
232 
233 	memset(label, '\0', sizeof(label));
234 
235 	for (i = 0;; i++) {
236 		if (show_unmountable == false && fstypes[i].unmountable == true)
237 			continue;
238 		fstyp_f = fstypes[i].function;
239 		if (fstyp_f == NULL)
240 			break;
241 
242 		error = fstyp_f(fp, label, sizeof(label));
243 		if (error == 0)
244 			break;
245 	}
246 
247 	if (fstypes[i].name == NULL) {
248 		warnx("%s: filesystem not recognized", path);
249 		return (1);
250 	}
251 
252 	if (show_label && label[0] != '\0') {
253 		/*
254 		 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
255 		 *      encodes spaces.
256 		 */
257 		nbytes = strsnvis(strvised, sizeof(strvised), label,
258 		    VIS_GLOB | VIS_NL, "\"'$");
259 		if (nbytes == -1)
260 			err(1, "strsnvis");
261 
262 		printf("%s %s\n", fstypes[i].name, strvised);
263 	} else {
264 		printf("%s\n", fstypes[i].name);
265 	}
266 
267 	return (0);
268 }
269