LXR qemu/block/parallels.c

   1/*
   2 * Block driver for Parallels disk image format
   3 *
   4 * Copyright (c) 2007 Alex Beregszaszi
   5 *
   6 * This code is based on comparing different disk images created by Parallels.
   7 *
   8 * Permission is hereby granted, free of charge, to any person obtaining a copy
   9 * of this software and associated documentation files (the "Software"), to deal
  10 * in the Software without restriction, including without limitation the rights
  11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 * copies of the Software, and to permit persons to whom the Software is
  13 * furnished to do so, subject to the following conditions:
  14 *
  15 * The above copyright notice and this permission notice shall be included in
  16 * all copies or substantial portions of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24 * THE SOFTWARE.
  25 */
  26#include "qemu-common.h"
  27#include "block/block_int.h"
  28#include "qemu/module.h"
  29
  30/**************************************************************/
  31
  32#define HEADER_MAGIC "WithoutFreeSpace"
  33#define HEADER_VERSION 2
  34#define HEADER_SIZE 64
  35
  36// always little-endian
  37struct parallels_header {
  38    char magic[16]; // "WithoutFreeSpace"
  39    uint32_t version;
  40    uint32_t heads;
  41    uint32_t cylinders;
  42    uint32_t tracks;
  43    uint32_t catalog_entries;
  44    uint32_t nb_sectors;
  45    char padding[24];
  46} QEMU_PACKED;
  47
  48typedef struct BDRVParallelsState {
  49    CoMutex lock;
  50
  51    uint32_t *catalog_bitmap;
  52    int catalog_size;
  53
  54    int tracks;
  55} BDRVParallelsState;
  56
  57static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
  58{
  59    const struct parallels_header *ph = (const void *)buf;
  60
  61    if (buf_size < HEADER_SIZE)
  62        return 0;
  63
  64    if (!memcmp(ph->magic, HEADER_MAGIC, 16) &&
  65        (le32_to_cpu(ph->version) == HEADER_VERSION))
  66        return 100;
  67
  68    return 0;
  69}
  70
  71static int parallels_open(BlockDriverState *bs, QDict *options, int flags)
  72{
  73    BDRVParallelsState *s = bs->opaque;
  74    int i;
  75    struct parallels_header ph;
  76    int ret;
  77
  78    bs->read_only = 1; // no write support yet
  79
  80    ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph));
  81    if (ret < 0) {
  82        goto fail;
  83    }
  84
  85    if (memcmp(ph.magic, HEADER_MAGIC, 16) ||
  86        (le32_to_cpu(ph.version) != HEADER_VERSION)) {
  87        ret = -EMEDIUMTYPE;
  88        goto fail;
  89    }
  90
  91    bs->total_sectors = le32_to_cpu(ph.nb_sectors);
  92
  93    s->tracks = le32_to_cpu(ph.tracks);
  94
  95    s->catalog_size = le32_to_cpu(ph.catalog_entries);
  96    s->catalog_bitmap = g_malloc(s->catalog_size * 4);
  97
  98    ret = bdrv_pread(bs->file, 64, s->catalog_bitmap, s->catalog_size * 4);
  99    if (ret < 0) {
 100        goto fail;
 101    }
 102
 103    for (i = 0; i < s->catalog_size; i++)
 104        le32_to_cpus(&s->catalog_bitmap[i]);
 105
 106    qemu_co_mutex_init(&s->lock);
 107    return 0;
 108
 109fail:
 110    g_free(s->catalog_bitmap);
 111    return ret;
 112}
 113
 114static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
 115{
 116    BDRVParallelsState *s = bs->opaque;
 117    uint32_t index, offset;
 118
 119    index = sector_num / s->tracks;
 120    offset = sector_num % s->tracks;
 121
 122    /* not allocated */
 123    if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))
 124        return -1;
 125    return (uint64_t)(s->catalog_bitmap[index] + offset) * 512;
 126}
 127
 128static int parallels_read(BlockDriverState *bs, int64_t sector_num,
 129                    uint8_t *buf, int nb_sectors)
 130{
 131    while (nb_sectors > 0) {
 132        int64_t position = seek_to_sector(bs, sector_num);
 133        if (position >= 0) {
 134            if (bdrv_pread(bs->file, position, buf, 512) != 512)
 135                return -1;
 136        } else {
 137            memset(buf, 0, 512);
 138        }
 139        nb_sectors--;
 140        sector_num++;
 141        buf += 512;
 142    }
 143    return 0;
 144}
 145
 146static coroutine_fn int parallels_co_read(BlockDriverState *bs, int64_t sector_num,
 147                                          uint8_t *buf, int nb_sectors)
 148{
 149    int ret;
 150    BDRVParallelsState *s = bs->opaque;
 151    qemu_co_mutex_lock(&s->lock);
 152    ret = parallels_read(bs, sector_num, buf, nb_sectors);
 153    qemu_co_mutex_unlock(&s->lock);
 154    return ret;
 155}
 156
 157static void parallels_close(BlockDriverState *bs)
 158{
 159    BDRVParallelsState *s = bs->opaque;
 160    g_free(s->catalog_bitmap);
 161}
 162
 163static BlockDriver bdrv_parallels = {
 164    .format_name        = "parallels",
 165    .instance_size      = sizeof(BDRVParallelsState),
 166    .bdrv_probe         = parallels_probe,
 167    .bdrv_open          = parallels_open,
 168    .bdrv_read          = parallels_co_read,
 169    .bdrv_close         = parallels_close,
 170};
 171
 172static void bdrv_parallels_init(void)
 173{
 174    bdrv_register(&bdrv_parallels);
 175}
 176
 177block_init(bdrv_parallels_init);
 178