Archipelago » qemu

/*

 * 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_int.h"

#include "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];

} __attribute__((packed));

typedef struct BDRVParallelsState {

    int fd;

    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, const char *filename, int flags)

{

    BDRVParallelsState *s = bs->opaque;

    int fd, i;

    struct parallels_header ph;

    fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);

    if (fd < 0) {

        fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);

        if (fd < 0)

            return -1;

    }

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

    s->fd = fd;

    if (read(fd, &ph, sizeof(ph)) != sizeof(ph))

        goto fail;

    if (memcmp(ph.magic, HEADER_MAGIC, 16) ||

        (le32_to_cpu(ph.version) != HEADER_VERSION)) {

        goto fail;

    }

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

    if (lseek(s->fd, 64, SEEK_SET) != 64)

        goto fail;

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

    s->catalog_size = le32_to_cpu(ph.catalog_entries);

    s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);

    if (read(s->fd, s->catalog_bitmap, s->catalog_size * 4) !=

        s->catalog_size * 4)

        goto fail;

    for (i = 0; i < s->catalog_size; i++)

        le32_to_cpus(&s->catalog_bitmap[i]);

    return 0;

fail:

    if (s->catalog_bitmap)

        qemu_free(s->catalog_bitmap);

    close(fd);

    return -1;

}

static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)

{

    BDRVParallelsState *s = bs->opaque;

    uint32_t index, offset;

    uint64_t position;

    index = sector_num / s->tracks;

    offset = sector_num % s->tracks;

    // not allocated

    if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))

        return -1;

    position = (uint64_t)(s->catalog_bitmap[index] + offset) * 512;

//    fprintf(stderr, "sector: %llx index=%x offset=%x pointer=%x position=%x\n",

//        sector_num, index, offset, s->catalog_bitmap[index], position);

    if (lseek(s->fd, position, SEEK_SET) != position)

        return -1;

    return 0;

}

static int parallels_read(BlockDriverState *bs, int64_t sector_num,

                    uint8_t *buf, int nb_sectors)

{

    BDRVParallelsState *s = bs->opaque;

    while (nb_sectors > 0) {

        if (!seek_to_sector(bs, sector_num)) {

            if (read(s->fd, buf, 512) != 512)

                return -1;

        } else

            memset(buf, 0, 512);

        nb_sectors--;

        sector_num++;

        buf += 512;

    }

    return 0;

}

static void parallels_close(BlockDriverState *bs)

{

    BDRVParallelsState *s = bs->opaque;

    qemu_free(s->catalog_bitmap);

    close(s->fd);

}

static BlockDriver bdrv_parallels = {

    .format_name        = "parallels",

    .instance_size        = sizeof(BDRVParallelsState),

    .bdrv_probe                = parallels_probe,

    .bdrv_open                = parallels_open,

    .bdrv_read                = parallels_read,

    .bdrv_close                = parallels_close,

};

static void bdrv_parallels_init(void)

{

    bdrv_register(&bdrv_parallels);

}

block_init(bdrv_parallels_init);