fstyp.c revision 277434 
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: stable/10/usr.sbin/fstyp/fstyp.c 277434 2015-01-20 20:39:29Z trasz $");
33
34#include <sys/capability.h>
35#include <sys/disk.h>
36#include <sys/ioctl.h>
37#include <sys/stat.h>
38#include <err.h>
39#include <errno.h>
40#include <stdbool.h>
41#include <stdint.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include <unistd.h>
46#include <vis.h>
47
48#include "fstyp.h"
49
50#define	LABEL_LEN	256
51
52typedef int (*fstyp_function)(FILE *, char *, size_t);
53
54static struct {
55	const char	*name;
56	fstyp_function	function;
57} fstypes[] = {
58	{ "cd9660", &fstyp_cd9660 },
59	{ "ext2fs", &fstyp_ext2fs },
60	{ "msdosfs", &fstyp_msdosfs },
61	{ "ntfs", &fstyp_ntfs },
62	{ "ufs", &fstyp_ufs },
63	{ NULL, NULL }
64};
65
66void *
67read_buf(FILE *fp, off_t off, size_t len)
68{
69	int error;
70	size_t nread;
71	void *buf;
72
73	error = fseek(fp, off, SEEK_SET);
74	if (error != 0) {
75		warn("cannot seek to %jd", (uintmax_t)off);
76		return (NULL);
77	}
78
79	buf = malloc(len);
80	if (buf == 0) {
81		warn("cannot malloc %zd bytes of memory", len);
82		return (NULL);
83	}
84
85	nread = fread(buf, len, 1, fp);
86	if (nread != 1) {
87		free(buf);
88		if (feof(fp) == 0)
89			warn("fread");
90		return (NULL);
91	}
92
93	return (buf);
94}
95
96char *
97checked_strdup(const char *s)
98{
99	char *c;
100
101	c = strdup(s);
102	if (c == NULL)
103		err(1, "strdup");
104	return (c);
105}
106
107static void
108usage(void)
109{
110
111	fprintf(stderr, "usage: fstyp [-l][-s] special\n");
112	exit(1);
113}
114
115static void
116type_check(const char *path, FILE *fp)
117{
118	int error, fd;
119	off_t mediasize;
120	struct stat sb;
121
122	fd = fileno(fp);
123
124	error = fstat(fd, &sb);
125	if (error != 0)
126		err(1, "%s: fstat", path);
127
128	if (S_ISREG(sb.st_mode))
129		return;
130
131	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
132	if (error != 0)
133		errx(1, "%s: not a disk", path);
134}
135
136int
137main(int argc, char **argv)
138{
139	int ch, error, i, nbytes;
140	bool ignore_type = false, show_label = false;
141	char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
142	char *path;
143	FILE *fp;
144	fstyp_function fstyp_f;
145
146	while ((ch = getopt(argc, argv, "ls")) != -1) {
147		switch (ch) {
148		case 'l':
149			show_label = true;
150			break;
151		case 's':
152			ignore_type = true;
153			break;
154		default:
155			usage();
156		}
157	}
158
159	argc -= optind;
160	argv += optind;
161	if (argc != 1)
162		usage();
163
164	path = argv[0];
165
166	fp = fopen(path, "r");
167	if (fp == NULL)
168		err(1, "%s", path);
169
170	error = cap_enter();
171	if (error != 0 && errno != ENOSYS)
172		err(1, "cap_enter");
173
174	if (ignore_type == false)
175		type_check(path, fp);
176
177	memset(label, '\0', sizeof(label));
178
179	for (i = 0;; i++) {
180		fstyp_f = fstypes[i].function;
181		if (fstyp_f == NULL)
182			break;
183
184		error = fstyp_f(fp, label, sizeof(label));
185		if (error == 0)
186			break;
187	}
188
189	if (fstypes[i].name == NULL) {
190		warnx("%s: filesystem not recognized", path);
191		return (1);
192	}
193
194	if (show_label && label[0] != '\0') {
195		/*
196		 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
197		 *      encodes spaces.
198		 */
199		nbytes = strsnvis(strvised, sizeof(strvised), label,
200		    VIS_GLOB | VIS_NL, "\"'$");
201		if (nbytes == -1)
202			err(1, "strsnvis");
203
204		printf("%s %s\n", fstypes[i].name, strvised);
205	} else {
206		printf("%s\n", fstypes[i].name);
207	}
208
209	return (0);
210}
211