1 /*
2  * volume_id - reads filesystem label and uuid
3  *
4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
5  *
6  *	This library is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU Lesser General Public
8  *	License as published by the Free Software Foundation; either
9  *	version 2.1 of the License, or (at your option) any later version.
10  *
11  *	This library is distributed in the hope that it will be useful,
12  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  *	Lesser General Public License for more details.
15  *
16  *	You should have received a copy of the GNU Lesser General Public
17  *	License along with this library; if not, write to the Free Software
18  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  */
20 //config:config FEATURE_VOLUMEID_ISO9660
21 //config:	bool "iso9660 filesystem"
22 //config:	default y
23 //config:	depends on VOLUMEID
24 
25 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_ISO9660) += iso9660.o
26 
27 #include "volume_id_internal.h"
28 
29 #define ISO_SUPERBLOCK_OFFSET		0x8000
30 #define ISO_SECTOR_SIZE			0x800
31 #define ISO_VD_OFFSET			(ISO_SUPERBLOCK_OFFSET + ISO_SECTOR_SIZE)
32 #define ISO_VD_PRIMARY			0x1
33 #define ISO_VD_SUPPLEMENTARY		0x2
34 #define ISO_VD_END			0xff
35 #define ISO_VD_MAX			16
36 
37 struct iso_volume_descriptor {
38 	uint8_t		vd_type;
39 	uint8_t		vd_id[5];
40 	uint8_t		vd_version;
41 	uint8_t		flags;
42 	uint8_t		system_id[32];
43 	uint8_t		volume_id[32];
44 	uint8_t		unused[8];
45 	uint8_t		space_size[8];
46 	uint8_t		escape_sequences[8];
47 } PACKED;
48 
49 struct high_sierra_volume_descriptor {
50 	uint8_t		foo[8];
51 	uint8_t		type;
52 	uint8_t		id[4];
53 	uint8_t		version;
54 } PACKED;
55 
volume_id_probe_iso9660(struct volume_id * id)56 int FAST_FUNC volume_id_probe_iso9660(struct volume_id *id /*,uint64_t off*/)
57 {
58 #define off ((uint64_t)0)
59 	uint8_t *buf;
60 	struct iso_volume_descriptor *is;
61 	struct high_sierra_volume_descriptor *hs;
62 
63 	dbg("probing at offset 0x%llx", (unsigned long long) off);
64 
65 	buf = volume_id_get_buffer(id, off + ISO_SUPERBLOCK_OFFSET, 0x200);
66 	if (buf == NULL)
67 		return -1;
68 
69 	is = (struct iso_volume_descriptor *) buf;
70 
71 	if (memcmp(is->vd_id, "CD001", 5) == 0) {
72 		int vd_offset;
73 		int i;
74 
75 		dbg("read label from PVD");
76 //		volume_id_set_label_raw(id, is->volume_id, 32);
77 		volume_id_set_label_string(id, is->volume_id, 32);
78 
79 		dbg("looking for SVDs");
80 		vd_offset = ISO_VD_OFFSET;
81 		for (i = 0; i < ISO_VD_MAX; i++) {
82 			uint8_t svd_label[64];
83 
84 			is = volume_id_get_buffer(id, off + vd_offset, 0x200);
85 			if (is == NULL || is->vd_type == ISO_VD_END)
86 				break;
87 			if (is->vd_type != ISO_VD_SUPPLEMENTARY)
88 				continue;
89 
90 			dbg("found SVD at offset 0x%llx", (unsigned long long) (off + vd_offset));
91 			if (memcmp(is->escape_sequences, "%/@", 3) == 0
92 			 || memcmp(is->escape_sequences, "%/C", 3) == 0
93 			 || memcmp(is->escape_sequences, "%/E", 3) == 0
94 			) {
95 				dbg("Joliet extension found");
96 				volume_id_set_unicode16((char *)svd_label, sizeof(svd_label), is->volume_id, BE, 32);
97 				if (memcmp(id->label, svd_label, 16) == 0) {
98 					dbg("SVD label is identical, use the possibly longer PVD one");
99 					break;
100 				}
101 
102 //				volume_id_set_label_raw(id, is->volume_id, 32);
103 				volume_id_set_label_string(id, svd_label, 32);
104 //				strcpy(id->type_version, "Joliet Extension");
105 				goto found;
106 			}
107 			vd_offset += ISO_SECTOR_SIZE;
108 		}
109 		goto found;
110 	}
111 
112 	hs = (struct high_sierra_volume_descriptor *) buf;
113 
114 	if (memcmp(hs->id, "CDROM", 5) == 0) {
115 //		strcpy(id->type_version, "High Sierra");
116 		goto found;
117 	}
118 
119 	return -1;
120 
121  found:
122 //	volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
123 	IF_FEATURE_BLKID_TYPE(id->type = "iso9660";)
124 
125 	return 0;
126 }
127