xref: /freebsd/sys/geom/label/g_label_iso9660.c (revision 9768746ba83efa02837c5b9c66348db6e900208f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5  * All rights reserved.
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 AUTHORS 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 AUTHORS 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 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 
37 #include <geom/geom.h>
38 #include <geom/geom_dbg.h>
39 #include <geom/label/g_label.h>
40 
41 #define	ISO9660_MAGIC	"\x01" "CD001" "\x01\x00"
42 #define	ISO9660_OFFSET	0x8000
43 #define	VOLUME_LEN	32
44 
45 static void
46 g_label_iso9660_taste(struct g_consumer *cp, char *label, size_t size)
47 {
48 	struct g_provider *pp;
49 	char *sector, *volume;
50 
51 	g_topology_assert_not();
52 	pp = cp->provider;
53 	label[0] = '\0';
54 
55 	KASSERT(pp->sectorsize != 0, ("Tasting a disk with 0 sectorsize"));
56 	if (pp->sectorsize < 0x28 + VOLUME_LEN)
57 		return;
58 	if ((ISO9660_OFFSET % pp->sectorsize) != 0)
59 		return;
60 	sector = g_read_data(cp, ISO9660_OFFSET, pp->sectorsize, NULL);
61 	if (sector == NULL)
62 		return;
63 	if (bcmp(sector, ISO9660_MAGIC, sizeof(ISO9660_MAGIC) - 1) != 0) {
64 		g_free(sector);
65 		return;
66 	}
67 	G_LABEL_DEBUG(1, "ISO9660 file system detected on %s.", pp->name);
68 	volume = sector + 0x28;
69 	bzero(label, size);
70 	strlcpy(label, volume, MIN(size, VOLUME_LEN));
71 	g_free(sector);
72 	g_label_rtrim(label, size);
73 }
74 
75 struct g_label_desc g_label_iso9660 = {
76 	.ld_taste = g_label_iso9660_taste,
77 	.ld_dirprefix = "iso9660/",
78 	.ld_enabled = 1
79 };
80 
81 G_LABEL_INIT(iso9660, g_label_iso9660, "Create device nodes for ISO9660 volume names");
82