xref: /freebsd/usr.sbin/fstyp/fstyp.c (revision c14a5a8800a0f7a007f8cd197b4cad4d26a78f8c)
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 #include <iconv.h>
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 static struct {
60 	const char	*name;
61 	fstyp_function	function;
62 	bool		unmountable;
63 	char		*precache_encoding;
64 } fstypes[] = {
65 	{ "cd9660", &fstyp_cd9660, false, NULL },
66 	{ "exfat", &fstyp_exfat, false, EXFAT_ENC },
67 	{ "ext2fs", &fstyp_ext2fs, false, NULL },
68 	{ "geli", &fstyp_geli, true, NULL },
69 	{ "msdosfs", &fstyp_msdosfs, false, NULL },
70 	{ "ntfs", &fstyp_ntfs, false, NULL },
71 	{ "ufs", &fstyp_ufs, false, NULL },
72 #ifdef HAVE_ZFS
73 	{ "zfs", &fstyp_zfs, true, NULL },
74 #endif
75 	{ NULL, NULL, NULL, NULL }
76 };
77 
78 void *
79 read_buf(FILE *fp, off_t off, size_t len)
80 {
81 	int error;
82 	size_t nread;
83 	void *buf;
84 
85 	error = fseek(fp, off, SEEK_SET);
86 	if (error != 0) {
87 		warn("cannot seek to %jd", (uintmax_t)off);
88 		return (NULL);
89 	}
90 
91 	buf = malloc(len);
92 	if (buf == NULL) {
93 		warn("cannot malloc %zd bytes of memory", len);
94 		return (NULL);
95 	}
96 
97 	nread = fread(buf, len, 1, fp);
98 	if (nread != 1) {
99 		free(buf);
100 		if (feof(fp) == 0)
101 			warn("fread");
102 		return (NULL);
103 	}
104 
105 	return (buf);
106 }
107 
108 char *
109 checked_strdup(const char *s)
110 {
111 	char *c;
112 
113 	c = strdup(s);
114 	if (c == NULL)
115 		err(1, "strdup");
116 	return (c);
117 }
118 
119 void
120 rtrim(char *label, size_t size)
121 {
122 	ptrdiff_t i;
123 
124 	for (i = size - 1; i >= 0; i--) {
125 		if (label[i] == '\0')
126 			continue;
127 		else if (label[i] == ' ')
128 			label[i] = '\0';
129 		else
130 			break;
131 	}
132 }
133 
134 static void
135 usage(void)
136 {
137 
138 	fprintf(stderr, "usage: fstyp [-l] [-s] [-u] special\n");
139 	exit(1);
140 }
141 
142 static void
143 type_check(const char *path, FILE *fp)
144 {
145 	int error, fd;
146 	off_t mediasize;
147 	struct stat sb;
148 
149 	fd = fileno(fp);
150 
151 	error = fstat(fd, &sb);
152 	if (error != 0)
153 		err(1, "%s: fstat", path);
154 
155 	if (S_ISREG(sb.st_mode))
156 		return;
157 
158 	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
159 	if (error != 0)
160 		errx(1, "%s: not a disk", path);
161 }
162 
163 int
164 main(int argc, char **argv)
165 {
166 	int ch, error, i, nbytes;
167 	bool ignore_type = false, show_unmountable = false;
168 	char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
169 	char *path;
170 	FILE *fp;
171 	fstyp_function fstyp_f;
172 
173 	while ((ch = getopt(argc, argv, "lsu")) != -1) {
174 		switch (ch) {
175 		case 'l':
176 			show_label = true;
177 			break;
178 		case 's':
179 			ignore_type = true;
180 			break;
181 		case 'u':
182 			show_unmountable = true;
183 			break;
184 		default:
185 			usage();
186 		}
187 	}
188 
189 	argc -= optind;
190 	argv += optind;
191 	if (argc != 1)
192 		usage();
193 
194 	path = argv[0];
195 
196 	if (setlocale(LC_CTYPE, "") == NULL)
197 		err(1, "setlocale");
198 	caph_cache_catpages();
199 
200 	/* Cache iconv conversion data before entering capability mode. */
201 	if (show_label) {
202 		for (i = 0; i < nitems(fstypes); i++) {
203 			iconv_t cd;
204 
205 			if (fstypes[i].precache_encoding == NULL)
206 				continue;
207 			cd = iconv_open("", fstypes[i].precache_encoding);
208 			if (cd == (iconv_t)-1)
209 				err(1, "%s: iconv_open %s", fstypes[i].name,
210 				    fstypes[i].precache_encoding);
211 			/* Iconv keeps a small cache of unused encodings. */
212 			iconv_close(cd);
213 		}
214 	}
215 
216 	fp = fopen(path, "r");
217 	if (fp == NULL)
218 		err(1, "%s", path);
219 
220 	if (caph_enter() < 0)
221 		err(1, "cap_enter");
222 
223 	if (ignore_type == false)
224 		type_check(path, fp);
225 
226 	memset(label, '\0', sizeof(label));
227 
228 	for (i = 0;; i++) {
229 		if (show_unmountable == false && fstypes[i].unmountable == true)
230 			continue;
231 		fstyp_f = fstypes[i].function;
232 		if (fstyp_f == NULL)
233 			break;
234 
235 		error = fstyp_f(fp, label, sizeof(label));
236 		if (error == 0)
237 			break;
238 	}
239 
240 	if (fstypes[i].name == NULL) {
241 		warnx("%s: filesystem not recognized", path);
242 		return (1);
243 	}
244 
245 	if (show_label && label[0] != '\0') {
246 		/*
247 		 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
248 		 *      encodes spaces.
249 		 */
250 		nbytes = strsnvis(strvised, sizeof(strvised), label,
251 		    VIS_GLOB | VIS_NL, "\"'$");
252 		if (nbytes == -1)
253 			err(1, "strsnvis");
254 
255 		printf("%s %s\n", fstypes[i].name, strvised);
256 	} else {
257 		printf("%s\n", fstypes[i].name);
258 	}
259 
260 	return (0);
261 }
262