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      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_int.h"
     28 #include "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
     37 struct 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 } __attribute__((packed));
     47 
     48 typedef struct BDRVParallelsState {
     49 
     50     uint32_t *catalog_bitmap;
     51     int catalog_size;
     52 
     53     int tracks;
     54 } BDRVParallelsState;
     55 
     56 static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename)
     57 {
     58     const struct parallels_header *ph = (const void *)buf;
     59 
     60     if (buf_size < HEADER_SIZE)
     61 	return 0;
     62 
     63     if (!memcmp(ph->magic, HEADER_MAGIC, 16) &&
     64 	(le32_to_cpu(ph->version) == HEADER_VERSION))
     65 	return 100;
     66 
     67     return 0;
     68 }
     69 
     70 static int parallels_open(BlockDriverState *bs, int flags)
     71 {
     72     BDRVParallelsState *s = bs->opaque;
     73     int i;
     74     struct parallels_header ph;
     75 
     76     bs->read_only = 1; // no write support yet
     77 
     78     if (bdrv_pread(bs->file, 0, &ph, sizeof(ph)) != sizeof(ph))
     79         goto fail;
     80 
     81     if (memcmp(ph.magic, HEADER_MAGIC, 16) ||
     82 	(le32_to_cpu(ph.version) != HEADER_VERSION)) {
     83         goto fail;
     84     }
     85 
     86     bs->total_sectors = le32_to_cpu(ph.nb_sectors);
     87 
     88     s->tracks = le32_to_cpu(ph.tracks);
     89 
     90     s->catalog_size = le32_to_cpu(ph.catalog_entries);
     91     s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);
     92     if (bdrv_pread(bs->file, 64, s->catalog_bitmap, s->catalog_size * 4) !=
     93 	s->catalog_size * 4)
     94 	goto fail;
     95     for (i = 0; i < s->catalog_size; i++)
     96 	le32_to_cpus(&s->catalog_bitmap[i]);
     97 
     98     return 0;
     99 fail:
    100     if (s->catalog_bitmap)
    101 	qemu_free(s->catalog_bitmap);
    102     return -1;
    103 }
    104 
    105 static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
    106 {
    107     BDRVParallelsState *s = bs->opaque;
    108     uint32_t index, offset;
    109 
    110     index = sector_num / s->tracks;
    111     offset = sector_num % s->tracks;
    112 
    113     /* not allocated */
    114     if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0))
    115 	return -1;
    116     return (uint64_t)(s->catalog_bitmap[index] + offset) * 512;
    117 }
    118 
    119 static int parallels_read(BlockDriverState *bs, int64_t sector_num,
    120                     uint8_t *buf, int nb_sectors)
    121 {
    122     while (nb_sectors > 0) {
    123         int64_t position = seek_to_sector(bs, sector_num);
    124         if (position >= 0) {
    125             if (bdrv_pread(bs->file, position, buf, 512) != 512)
    126                 return -1;
    127         } else {
    128             memset(buf, 0, 512);
    129         }
    130         nb_sectors--;
    131         sector_num++;
    132         buf += 512;
    133     }
    134     return 0;
    135 }
    136 
    137 static void parallels_close(BlockDriverState *bs)
    138 {
    139     BDRVParallelsState *s = bs->opaque;
    140     qemu_free(s->catalog_bitmap);
    141 }
    142 
    143 static BlockDriver bdrv_parallels = {
    144     .format_name	= "parallels",
    145     .instance_size	= sizeof(BDRVParallelsState),
    146     .bdrv_probe		= parallels_probe,
    147     .bdrv_open		= parallels_open,
    148     .bdrv_read		= parallels_read,
    149     .bdrv_close		= parallels_close,
    150 };
    151 
    152 static void bdrv_parallels_init(void)
    153 {
    154     bdrv_register(&bdrv_parallels);
    155 }
    156 
    157 block_init(bdrv_parallels_init);
    158