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_MAGIC2 "WithouFreSpacExt" 34 #define HEADER_VERSION 2 35 #define HEADER_SIZE 64 36 37 // always little-endian 38 struct parallels_header { 39 char magic[16]; // "WithoutFreeSpace" 40 uint32_t version; 41 uint32_t heads; 42 uint32_t cylinders; 43 uint32_t tracks; 44 uint32_t catalog_entries; 45 uint64_t nb_sectors; 46 uint32_t inuse; 47 uint32_t data_off; 48 char padding[12]; 49 } QEMU_PACKED; 50 51 typedef struct BDRVParallelsState { 52 CoMutex lock; 53 54 uint32_t *catalog_bitmap; 55 unsigned int catalog_size; 56 57 unsigned int tracks; 58 59 unsigned int off_multiplier; 60 } BDRVParallelsState; 61 62 static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename) 63 { 64 const struct parallels_header *ph = (const void *)buf; 65 66 if (buf_size < HEADER_SIZE) 67 return 0; 68 69 if ((!memcmp(ph->magic, HEADER_MAGIC, 16) || 70 !memcmp(ph->magic, HEADER_MAGIC2, 16)) && 71 (le32_to_cpu(ph->version) == HEADER_VERSION)) 72 return 100; 73 74 return 0; 75 } 76 77 static int parallels_open(BlockDriverState *bs, QDict *options, int flags, 78 Error **errp) 79 { 80 BDRVParallelsState *s = bs->opaque; 81 int i; 82 struct parallels_header ph; 83 int ret; 84 85 bs->read_only = 1; // no write support yet 86 87 ret = bdrv_pread(bs->file, 0, &ph, sizeof(ph)); 88 if (ret < 0) { 89 goto fail; 90 } 91 92 bs->total_sectors = le64_to_cpu(ph.nb_sectors); 93 94 if (le32_to_cpu(ph.version) != HEADER_VERSION) { 95 goto fail_format; 96 } 97 if (!memcmp(ph.magic, HEADER_MAGIC, 16)) { 98 s->off_multiplier = 1; 99 bs->total_sectors = 0xffffffff & bs->total_sectors; 100 } else if (!memcmp(ph.magic, HEADER_MAGIC2, 16)) { 101 s->off_multiplier = le32_to_cpu(ph.tracks); 102 } else { 103 goto fail_format; 104 } 105 106 s->tracks = le32_to_cpu(ph.tracks); 107 if (s->tracks == 0) { 108 error_setg(errp, "Invalid image: Zero sectors per track"); 109 ret = -EINVAL; 110 goto fail; 111 } 112 if (s->tracks > INT32_MAX/513) { 113 error_setg(errp, "Invalid image: Too big cluster"); 114 ret = -EFBIG; 115 goto fail; 116 } 117 118 s->catalog_size = le32_to_cpu(ph.catalog_entries); 119 if (s->catalog_size > INT_MAX / 4) { 120 error_setg(errp, "Catalog too large"); 121 ret = -EFBIG; 122 goto fail; 123 } 124 s->catalog_bitmap = g_try_new(uint32_t, s->catalog_size); 125 if (s->catalog_size && s->catalog_bitmap == NULL) { 126 ret = -ENOMEM; 127 goto fail; 128 } 129 130 ret = bdrv_pread(bs->file, 64, s->catalog_bitmap, s->catalog_size * 4); 131 if (ret < 0) { 132 goto fail; 133 } 134 135 for (i = 0; i < s->catalog_size; i++) 136 le32_to_cpus(&s->catalog_bitmap[i]); 137 138 qemu_co_mutex_init(&s->lock); 139 return 0; 140 141 fail_format: 142 error_setg(errp, "Image not in Parallels format"); 143 ret = -EINVAL; 144 fail: 145 g_free(s->catalog_bitmap); 146 return ret; 147 } 148 149 static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num) 150 { 151 BDRVParallelsState *s = bs->opaque; 152 uint32_t index, offset; 153 154 index = sector_num / s->tracks; 155 offset = sector_num % s->tracks; 156 157 /* not allocated */ 158 if ((index > s->catalog_size) || (s->catalog_bitmap[index] == 0)) 159 return -1; 160 return 161 ((uint64_t)s->catalog_bitmap[index] * s->off_multiplier + offset) * 512; 162 } 163 164 static int parallels_read(BlockDriverState *bs, int64_t sector_num, 165 uint8_t *buf, int nb_sectors) 166 { 167 while (nb_sectors > 0) { 168 int64_t position = seek_to_sector(bs, sector_num); 169 if (position >= 0) { 170 if (bdrv_pread(bs->file, position, buf, 512) != 512) 171 return -1; 172 } else { 173 memset(buf, 0, 512); 174 } 175 nb_sectors--; 176 sector_num++; 177 buf += 512; 178 } 179 return 0; 180 } 181 182 static coroutine_fn int parallels_co_read(BlockDriverState *bs, int64_t sector_num, 183 uint8_t *buf, int nb_sectors) 184 { 185 int ret; 186 BDRVParallelsState *s = bs->opaque; 187 qemu_co_mutex_lock(&s->lock); 188 ret = parallels_read(bs, sector_num, buf, nb_sectors); 189 qemu_co_mutex_unlock(&s->lock); 190 return ret; 191 } 192 193 static void parallels_close(BlockDriverState *bs) 194 { 195 BDRVParallelsState *s = bs->opaque; 196 g_free(s->catalog_bitmap); 197 } 198 199 static BlockDriver bdrv_parallels = { 200 .format_name = "parallels", 201 .instance_size = sizeof(BDRVParallelsState), 202 .bdrv_probe = parallels_probe, 203 .bdrv_open = parallels_open, 204 .bdrv_read = parallels_co_read, 205 .bdrv_close = parallels_close, 206 }; 207 208 static void bdrv_parallels_init(void) 209 { 210 bdrv_register(&bdrv_parallels); 211 } 212 213 block_init(bdrv_parallels_init); 214