qemu/block/parallels.c

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/*
* 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_MAGIC2 "WithouFreSpacExt"
#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;
uint64_t nb_sectors;
uint32_t inuse;
uint32_t data_off;
char padding[12];
} QEMU_PACKED;
typedef struct BDRVParallelsState {
CoMutex lock;
uint32_t *catalog_bitmap;
unsigned int catalog_size;
unsigned int tracks;
unsigned int off_multiplier;
} 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) ||
!memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
(le32_to_cpu(ph->version) == HEADER_VERSION))
return 100;
return 0;
}
static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
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;
}
bs->total_sectors = le64_to_cpu(ph.nb_sectors);
if (le32_to_cpu(ph.version) != HEADER_VERSION) {
goto fail_format;
}
if (!memcmp(ph.magic, HEADER_MAGIC, 16)) {
s->off_multiplier = 1;
bs->total_sectors = 0xffffffff & bs->total_sectors;
} else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) {
s->off_multiplier = le32_to_cpu(ph.tracks);
} else {
goto fail_format;
}
s->tracks = le32_to_cpu(ph.tracks);
if (s->tracks == 0) {
error_setg(errp, "Invalid image: Zero sectors per track");
ret = -EINVAL;
goto fail;
}
if (s->tracks > INT32_MAX/513) {
error_setg(errp, "Invalid image: Too big cluster");
ret = -EFBIG;
goto fail;
}
s->catalog_size = le32_to_cpu(ph.catalog_entries);
if (s->catalog_size > INT_MAX / 4) {
error_setg(errp, "Catalog too large");
ret = -EFBIG;
goto fail;
}
s->catalog_bitmap = g_try_new(uint32_t, s->catalog_size);
if (s->catalog_size && s->catalog_bitmap == NULL) {
ret = -ENOMEM;
goto fail;
}
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_format:
error_setg(errp, "Image not in Parallels format");
ret = -EINVAL;
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] * s->off_multiplier + 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);