1/*
2 * volume_id - reads filesystem label and uuid
3 *
4 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
5 *
6 *	This program is free software; you can redistribute it and/or modify it
7 *	under the terms of the GNU General Public License as published by the
8 *	Free Software Foundation version 2 of the License.
9 */
10
11#ifndef _GNU_SOURCE
12#define _GNU_SOURCE 1
13#endif
14
15#ifdef HAVE_CONFIG_H
16#  include <config.h>
17#endif
18
19#include <stdio.h>
20#include <stdlib.h>
21#include <unistd.h>
22#include <string.h>
23#include <errno.h>
24#include <ctype.h>
25
26#include "libvolume_id.h"
27#include "util.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
37struct iso_volume_descriptor {
38	uint8_t		type;
39	uint8_t		id[5];
40	uint8_t		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
49struct high_sierra_volume_descriptor {
50	uint8_t		foo[8];
51	uint8_t		type;
52	uint8_t		id[5];
53	uint8_t		version;
54} PACKED;
55
56int volume_id_probe_iso9660(struct volume_id *id, uint64_t off, uint64_t size)
57{
58	uint8_t *buf;
59	struct iso_volume_descriptor *is;
60	struct high_sierra_volume_descriptor *hs;
61
62	info("probing at offset 0x%llx", (unsigned long long) off);
63
64	buf = volume_id_get_buffer(id, off + ISO_SUPERBLOCK_OFFSET, 0x200);
65	if (buf == NULL)
66		return -1;
67
68	is = (struct iso_volume_descriptor *) buf;
69
70	if (memcmp(is->id, "CD001", 5) == 0) {
71		int vd_offset;
72		int i;
73
74		dbg("read label from PVD");
75		volume_id_set_label_raw(id, is->volume_id, 32);
76		volume_id_set_label_string(id, is->volume_id, 32);
77
78		dbg("looking for SVDs");
79		vd_offset = ISO_VD_OFFSET;
80		for (i = 0; i < ISO_VD_MAX; i++) {
81			uint8_t svd_label[64];
82
83			is = (struct iso_volume_descriptor *) volume_id_get_buffer(id, off + vd_offset, 0x200);
84			if (is == NULL || is->type == ISO_VD_END)
85				break;
86			if (is->type != ISO_VD_SUPPLEMENTARY)
87				continue;
88
89			dbg("found SVD at offset 0x%llx", (unsigned long long) (off + vd_offset));
90			if (memcmp(is->escape_sequences, "%/@", 3) == 0||
91			    memcmp(is->escape_sequences, "%/C", 3) == 0||
92			    memcmp(is->escape_sequences, "%/E", 3) == 0) {
93				dbg("Joliet extension found");
94				volume_id_set_unicode16(svd_label, sizeof(svd_label), is->volume_id, BE, 32);
95				if (memcmp(id->label, svd_label, 16) == 0) {
96					dbg("SVD label is identical, use the possibly longer PVD one");
97					break;
98				}
99
100				volume_id_set_label_raw(id, is->volume_id, 32);
101				volume_id_set_label_string(id, svd_label, 32);
102				strcpy(id->type_version, "Joliet Extension");
103				goto found;
104			}
105			vd_offset += ISO_SECTOR_SIZE;
106		}
107		goto found;
108	}
109
110	hs = (struct high_sierra_volume_descriptor *) buf;
111
112	if (memcmp(hs->id, "CDROM", 5) == 0) {
113		strcpy(id->type_version, "High Sierra");
114		goto found;
115	}
116
117	return -1;
118
119found:
120	volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
121	id->type = "iso9660";
122
123	return 0;
124}
125