xref: /freebsd/sys/geom/label/g_label_iso9660.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/malloc.h>
34 
35 #include <geom/geom.h>
36 #include <geom/geom_dbg.h>
37 #include <geom/label/g_label.h>
38 
39 #define	ISO9660_MAGIC	"\x01" "CD001" "\x01\x00"
40 #define	ISO9660_OFFSET	0x8000
41 #define	VOLUME_LEN	32
42 
43 static void
44 g_label_iso9660_taste(struct g_consumer *cp, char *label, size_t size)
45 {
46 	struct g_provider *pp;
47 	char *sector, *volume;
48 
49 	g_topology_assert_not();
50 	pp = cp->provider;
51 	label[0] = '\0';
52 
53 	KASSERT(pp->sectorsize != 0, ("Tasting a disk with 0 sectorsize"));
54 	if (pp->sectorsize < 0x28 + VOLUME_LEN)
55 		return;
56 	if ((ISO9660_OFFSET % pp->sectorsize) != 0)
57 		return;
58 	sector = g_read_data(cp, ISO9660_OFFSET, pp->sectorsize, NULL);
59 	if (sector == NULL)
60 		return;
61 	if (bcmp(sector, ISO9660_MAGIC, sizeof(ISO9660_MAGIC) - 1) != 0) {
62 		g_free(sector);
63 		return;
64 	}
65 	G_LABEL_DEBUG(1, "ISO9660 file system detected on %s.", pp->name);
66 	volume = sector + 0x28;
67 	bzero(label, size);
68 	strlcpy(label, volume, MIN(size, VOLUME_LEN));
69 	g_free(sector);
70 	g_label_rtrim(label, size);
71 }
72 
73 struct g_label_desc g_label_iso9660 = {
74 	.ld_taste = g_label_iso9660_taste,
75 	.ld_dirprefix = "iso9660/",
76 	.ld_enabled = 1
77 };
78 
79 G_LABEL_INIT(iso9660, g_label_iso9660, "Create device nodes for ISO9660 volume names");
80