On Mon, Jul 28, 2014 at 08:23:55PM +0400, Denis V. Lunev wrote:
> Parallels has released in the recent updates of Parallels Server 5/6
> new addition to his image format. Images with signature WithouFreSpacExt
> have offsets in the catalog coded not as offsets in sectors (multiple
> of 512 bytes) but offsets coded in blocks (i.e. header->tracks * 512)
>
> In this case all 64 bits of header->nb_sectors are used for image size.
>
> This patch implements support of this for qemu-img and also adds specific
> check for an incorrect image. Images with block size greater than
> INT_MAX/513 are not supported. The biggest available Parallels image
> cluster size in the field is 1 Mb. Thus this limit will not hurt
> anyone.
>
> Signed-off-by: Denis V. Lunev <d...@openvz.org>
> CC: Jeff Cody <jc...@redhat.com>
> CC: Kevin Wolf <kw...@redhat.com>
> CC: Stefan Hajnoczi <stefa...@redhat.com>
> ---
> block/parallels.c | 25 ++++++++++++++++++++-----
> 1 file changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 466705e..4414a9d 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -30,6 +30,7 @@
> /**************************************************************/
>
> #define HEADER_MAGIC "WithoutFreeSpace"
> +#define HEADER_MAGIC2 "WithouFreSpacExt"
> #define HEADER_VERSION 2
> #define HEADER_SIZE 64
>
> @@ -54,6 +55,8 @@ typedef struct BDRVParallelsState {
> 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)
> @@ -63,7 +66,8 @@ static int parallels_probe(const uint8_t *buf, int
> buf_size, const char *filenam
> if (buf_size < HEADER_SIZE)
> return 0;
>
> - if (!memcmp(ph->magic, HEADER_MAGIC, 16) &&
> + if ((!memcmp(ph->magic, HEADER_MAGIC, 16) ||
> + !memcmp(ph->magic, HEADER_MAGIC2, 16)) &&
> (le32_to_cpu(ph->version) == HEADER_VERSION))
> return 100;
>
> @@ -85,21 +89,31 @@ static int parallels_open(BlockDriverState *bs, QDict
> *options, int flags,
> 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)) {
> + 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;
> }
>
> - bs->total_sectors = 0xffffffff & le64_to_cpu(ph.nb_sectors);
> -
> 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) {
> @@ -139,7 +153,8 @@ static int64_t seek_to_sector(BlockDriverState *bs,
> int64_t sector_num)
> /* not allocated */
> if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))
> return -1;
> - return (uint64_t)(s->catalog_bitmap[index] + offset) * 512;
> + return
> + ((uint64_t)s->catalog_bitmap[index] * s->off_multiplier + offset) *
> 512;
This still does a cast to uint_64_t, instead of int64_t; not sure it
really matters in practice, as we should be safe now from exceeding an
int64_t value in the end result.
> }
>
> static int parallels_read(BlockDriverState *bs, int64_t sector_num,
> --
> 1.9.1
>
>
