aboutsummaryrefslogtreecommitdiff
path: root/block/parallels.c
blob: 8688f6ca4c1654b43dd75eeefa50d4f0b1aa61e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 * Block driver for Parallels disk image format
 *
 * Copyright (c) 2007 Alex Beregszaszi
 *
 * This code is based on comparing different disk images created by Parallels.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "qemu-common.h"
#include "block/block_int.h"
#include "qemu/module.h"

/**************************************************************/

#define HEADER_MAGIC "WithoutFreeSpace"
#define HEADER_VERSION 2
#define HEADER_SIZE 64

// always little-endian
struct parallels_header {
    char magic[16]; // "WithoutFreeSpace"
    uint32_t version;
    uint32_t heads;
    uint32_t cylinders;
    uint32_t tracks;
    uint32_t catalog_entries;
    uint32_t nb_sectors;
    char padding[24];
} QEMU_PACKED;

typedef struct BDRVParallelsState {
    CoMutex lock;

    uint32_t *catalog_bitmap;
    int catalog_size;

    int tracks;
} BDRVParallelsState;

static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
{
    const struct parallels_header *ph = (const void *)buf;

    if (buf_size < HEADER_SIZE)
	return 0;

    if (!memcmp(ph->magic, HEADER_MAGIC, 16) &&
	(le32_to_cpu(ph->version) == HEADER_VERSION))
	return 100;

    return 0;
}

static int parallels_open(BlockDriverState *bs, int flags)
{
    BDRVParallelsState *s = bs->opaque;
    int i;
    struct parallels_header ph;
    int ret;

    bs->read_only = 1; // no write support yet

    ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
    if (ret < 0) {
        goto fail;
    }

    if (memcmp(ph.magic, HEADER_MAGIC, 16) ||
        (le32_to_cpu(ph.version) != HEADER_VERSION)) {
        ret = -EMEDIUMTYPE;
        goto fail;
    }

    bs->total_sectors = le32_to_cpu(ph.nb_sectors);

    s->tracks = le32_to_cpu(ph.tracks);

    s->catalog_size = le32_to_cpu(ph.catalog_entries);
    s->catalog_bitmap = g_malloc(s->catalog_size * 4);

    ret = bdrv_pread(bs->file, 64, s->catalog_bitmap, s->catalog_size * 4);
    if (ret < 0) {
        goto fail;
    }

    for (i = 0; i < s->catalog_size; i++)
	le32_to_cpus(&s->catalog_bitmap[i]);

    qemu_co_mutex_init(&s->lock);
    return 0;

fail:
    g_free(s->catalog_bitmap);
    return ret;
}

static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
{
    BDRVParallelsState *s = bs->opaque;
    uint32_t index, offset;

    index = sector_num / s->tracks;
    offset = sector_num % s->tracks;

    /* not allocated */
    if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))
	return -1;
    return (uint64_t)(s->catalog_bitmap[index] + offset) * 512;
}

static int parallels_read(BlockDriverState *bs, int64_t sector_num,
                    uint8_t *buf, int nb_sectors)
{
    while (nb_sectors > 0) {
        int64_t position = seek_to_sector(bs, sector_num);
        if (position >= 0) {
            if (bdrv_pread(bs->file, position, buf, 512) != 512)
                return -1;
        } else {
            memset(buf, 0, 512);
        }
        nb_sectors--;
        sector_num++;
        buf += 512;
    }
    return 0;
}

static coroutine_fn int parallels_co_read(BlockDriverState *bs, int64_t sector_num,
                                          uint8_t *buf, int nb_sectors)
{
    int ret;
    BDRVParallelsState *s = bs->opaque;
    qemu_co_mutex_lock(&s->lock);
    ret = parallels_read(bs, sector_num, buf, nb_sectors);
    qemu_co_mutex_unlock(&s->lock);
    return ret;
}

static void parallels_close(BlockDriverState *bs)
{
    BDRVParallelsState *s = bs->opaque;
    g_free(s->catalog_bitmap);
}

static BlockDriver bdrv_parallels = {
    .format_name	= "parallels",
    .instance_size	= sizeof(BDRVParallelsState),
    .bdrv_probe		= parallels_probe,
    .bdrv_open		= parallels_open,
    .bdrv_read          = parallels_co_read,
    .bdrv_close		= parallels_close,
};

static void bdrv_parallels_init(void)
{
    bdrv_register(&bdrv_parallels);
}

block_init(bdrv_parallels_init);