xref: /freebsd/sys/geom/label/g_label_iso9660.c (revision 97549c34ecaf74580941fdc9c5bd1050e4b1f6ce)
1 /*-
2  * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
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/label/g_label.h>
37 
38 #define G_LABEL_ISO9660_DIR	"iso9660"
39 
40 #define	ISO9660_MAGIC	"\x01" "CD001" "\x01\x00"
41 #define	ISO9660_OFFSET	0x8000
42 #define	VOLUME_LEN	32
43 
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 	if ((ISO9660_OFFSET % pp->sectorsize) != 0)
56 		return;
57 	sector = (char *)g_read_data(cp, ISO9660_OFFSET, pp->sectorsize,
58 	    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_dir = G_LABEL_ISO9660_DIR,
76 	.ld_enabled = 1
77 };
78 
79 G_LABEL_INIT(iso9660, g_label_iso9660, "Create device nodes for ISO9660 volume names");
80