dmg.c (24680B)
1 /* 2 * QEMU Block driver for DMG images 3 * 4 * Copyright (c) 2004 Johannes E. Schindelin 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "qemu/osdep.h" 25 #include "qapi/error.h" 26 #include "block/block_int.h" 27 #include "qemu/bswap.h" 28 #include "qemu/error-report.h" 29 #include "qemu/module.h" 30 #include "qemu/memalign.h" 31 #include "dmg.h" 32 33 int (*dmg_uncompress_bz2)(char *next_in, unsigned int avail_in, 34 char *next_out, unsigned int avail_out); 35 36 int (*dmg_uncompress_lzfse)(char *next_in, unsigned int avail_in, 37 char *next_out, unsigned int avail_out); 38 39 enum { 40 /* Limit chunk sizes to prevent unreasonable amounts of memory being used 41 * or truncating when converting to 32-bit types 42 */ 43 DMG_LENGTHS_MAX = 64 * 1024 * 1024, /* 64 MB */ 44 DMG_SECTORCOUNTS_MAX = DMG_LENGTHS_MAX / 512, 45 }; 46 47 enum { 48 /* DMG Block Type */ 49 UDZE = 0, /* Zeroes */ 50 UDRW, /* RAW type */ 51 UDIG, /* Ignore */ 52 UDCO = 0x80000004, 53 UDZO, 54 UDBZ, 55 ULFO, 56 UDCM = 0x7ffffffe, /* Comments */ 57 UDLE = 0xffffffff /* Last Entry */ 58 }; 59 60 static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename) 61 { 62 int len; 63 64 if (!filename) { 65 return 0; 66 } 67 68 len = strlen(filename); 69 if (len > 4 && !strcmp(filename + len - 4, ".dmg")) { 70 return 2; 71 } 72 return 0; 73 } 74 75 static int read_uint64(BlockDriverState *bs, int64_t offset, uint64_t *result) 76 { 77 uint64_t buffer; 78 int ret; 79 80 ret = bdrv_pread(bs->file, offset, 8, &buffer, 0); 81 if (ret < 0) { 82 return ret; 83 } 84 85 *result = be64_to_cpu(buffer); 86 return 0; 87 } 88 89 static int read_uint32(BlockDriverState *bs, int64_t offset, uint32_t *result) 90 { 91 uint32_t buffer; 92 int ret; 93 94 ret = bdrv_pread(bs->file, offset, 4, &buffer, 0); 95 if (ret < 0) { 96 return ret; 97 } 98 99 *result = be32_to_cpu(buffer); 100 return 0; 101 } 102 103 static inline uint64_t buff_read_uint64(const uint8_t *buffer, int64_t offset) 104 { 105 return be64_to_cpu(*(uint64_t *)&buffer[offset]); 106 } 107 108 static inline uint32_t buff_read_uint32(const uint8_t *buffer, int64_t offset) 109 { 110 return be32_to_cpu(*(uint32_t *)&buffer[offset]); 111 } 112 113 /* Increase max chunk sizes, if necessary. This function is used to calculate 114 * the buffer sizes needed for compressed/uncompressed chunk I/O. 115 */ 116 static void update_max_chunk_size(BDRVDMGState *s, uint32_t chunk, 117 uint32_t *max_compressed_size, 118 uint32_t *max_sectors_per_chunk) 119 { 120 uint32_t compressed_size = 0; 121 uint32_t uncompressed_sectors = 0; 122 123 switch (s->types[chunk]) { 124 case UDZO: /* zlib compressed */ 125 case UDBZ: /* bzip2 compressed */ 126 case ULFO: /* lzfse compressed */ 127 compressed_size = s->lengths[chunk]; 128 uncompressed_sectors = s->sectorcounts[chunk]; 129 break; 130 case UDRW: /* copy */ 131 uncompressed_sectors = DIV_ROUND_UP(s->lengths[chunk], 512); 132 break; 133 case UDZE: /* zero */ 134 case UDIG: /* ignore */ 135 /* as the all-zeroes block may be large, it is treated specially: the 136 * sector is not copied from a large buffer, a simple memset is used 137 * instead. Therefore uncompressed_sectors does not need to be set. */ 138 break; 139 } 140 141 if (compressed_size > *max_compressed_size) { 142 *max_compressed_size = compressed_size; 143 } 144 if (uncompressed_sectors > *max_sectors_per_chunk) { 145 *max_sectors_per_chunk = uncompressed_sectors; 146 } 147 } 148 149 static int64_t dmg_find_koly_offset(BdrvChild *file, Error **errp) 150 { 151 BlockDriverState *file_bs = file->bs; 152 int64_t length; 153 int64_t offset = 0; 154 uint8_t buffer[515]; 155 int i, ret; 156 157 /* bdrv_getlength returns a multiple of block size (512), rounded up. Since 158 * dmg images can have odd sizes, try to look for the "koly" magic which 159 * marks the begin of the UDIF trailer (512 bytes). This magic can be found 160 * in the last 511 bytes of the second-last sector or the first 4 bytes of 161 * the last sector (search space: 515 bytes) */ 162 length = bdrv_getlength(file_bs); 163 if (length < 0) { 164 error_setg_errno(errp, -length, 165 "Failed to get file size while reading UDIF trailer"); 166 return length; 167 } else if (length < 512) { 168 error_setg(errp, "dmg file must be at least 512 bytes long"); 169 return -EINVAL; 170 } 171 if (length > 511 + 512) { 172 offset = length - 511 - 512; 173 } 174 length = length < 515 ? length : 515; 175 ret = bdrv_pread(file, offset, length, buffer, 0); 176 if (ret < 0) { 177 error_setg_errno(errp, -ret, "Failed while reading UDIF trailer"); 178 return ret; 179 } 180 for (i = 0; i < length - 3; i++) { 181 if (buffer[i] == 'k' && buffer[i+1] == 'o' && 182 buffer[i+2] == 'l' && buffer[i+3] == 'y') { 183 return offset + i; 184 } 185 } 186 error_setg(errp, "Could not locate UDIF trailer in dmg file"); 187 return -EINVAL; 188 } 189 190 /* used when building the sector table */ 191 typedef struct DmgHeaderState { 192 /* used internally by dmg_read_mish_block to remember offsets of blocks 193 * across calls */ 194 uint64_t data_fork_offset; 195 /* exported for dmg_open */ 196 uint32_t max_compressed_size; 197 uint32_t max_sectors_per_chunk; 198 } DmgHeaderState; 199 200 static bool dmg_is_known_block_type(uint32_t entry_type) 201 { 202 switch (entry_type) { 203 case UDZE: /* zeros */ 204 case UDRW: /* uncompressed */ 205 case UDIG: /* ignore */ 206 case UDZO: /* zlib */ 207 return true; 208 case UDBZ: /* bzip2 */ 209 return !!dmg_uncompress_bz2; 210 case ULFO: /* lzfse */ 211 return !!dmg_uncompress_lzfse; 212 default: 213 return false; 214 } 215 } 216 217 static int dmg_read_mish_block(BDRVDMGState *s, DmgHeaderState *ds, 218 uint8_t *buffer, uint32_t count) 219 { 220 uint32_t type, i; 221 int ret; 222 size_t new_size; 223 uint32_t chunk_count; 224 int64_t offset = 0; 225 uint64_t data_offset; 226 uint64_t in_offset = ds->data_fork_offset; 227 uint64_t out_offset; 228 229 type = buff_read_uint32(buffer, offset); 230 /* skip data that is not a valid MISH block (invalid magic or too small) */ 231 if (type != 0x6d697368 || count < 244) { 232 /* assume success for now */ 233 return 0; 234 } 235 236 /* chunk offsets are relative to this sector number */ 237 out_offset = buff_read_uint64(buffer, offset + 8); 238 239 /* location in data fork for (compressed) blob (in bytes) */ 240 data_offset = buff_read_uint64(buffer, offset + 0x18); 241 in_offset += data_offset; 242 243 /* move to begin of chunk entries */ 244 offset += 204; 245 246 chunk_count = (count - 204) / 40; 247 new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count); 248 s->types = g_realloc(s->types, new_size / 2); 249 s->offsets = g_realloc(s->offsets, new_size); 250 s->lengths = g_realloc(s->lengths, new_size); 251 s->sectors = g_realloc(s->sectors, new_size); 252 s->sectorcounts = g_realloc(s->sectorcounts, new_size); 253 254 for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) { 255 s->types[i] = buff_read_uint32(buffer, offset); 256 if (!dmg_is_known_block_type(s->types[i])) { 257 switch (s->types[i]) { 258 case UDBZ: 259 warn_report_once("dmg-bzip2 module is missing, accessing bzip2 " 260 "compressed blocks will result in I/O errors"); 261 break; 262 case ULFO: 263 warn_report_once("dmg-lzfse module is missing, accessing lzfse " 264 "compressed blocks will result in I/O errors"); 265 break; 266 case UDCM: 267 case UDLE: 268 /* Comments and last entry can be ignored without problems */ 269 break; 270 default: 271 warn_report_once("Image contains chunks of unknown type %x, " 272 "accessing them will result in I/O errors", 273 s->types[i]); 274 break; 275 } 276 chunk_count--; 277 i--; 278 offset += 40; 279 continue; 280 } 281 282 /* sector number */ 283 s->sectors[i] = buff_read_uint64(buffer, offset + 8); 284 s->sectors[i] += out_offset; 285 286 /* sector count */ 287 s->sectorcounts[i] = buff_read_uint64(buffer, offset + 0x10); 288 289 /* all-zeroes sector (type UDZE and UDIG) does not need to be 290 * "uncompressed" and can therefore be unbounded. */ 291 if (s->types[i] != UDZE && s->types[i] != UDIG 292 && s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) { 293 error_report("sector count %" PRIu64 " for chunk %" PRIu32 294 " is larger than max (%u)", 295 s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX); 296 ret = -EINVAL; 297 goto fail; 298 } 299 300 /* offset in (compressed) data fork */ 301 s->offsets[i] = buff_read_uint64(buffer, offset + 0x18); 302 s->offsets[i] += in_offset; 303 304 /* length in (compressed) data fork */ 305 s->lengths[i] = buff_read_uint64(buffer, offset + 0x20); 306 307 if (s->lengths[i] > DMG_LENGTHS_MAX) { 308 error_report("length %" PRIu64 " for chunk %" PRIu32 309 " is larger than max (%u)", 310 s->lengths[i], i, DMG_LENGTHS_MAX); 311 ret = -EINVAL; 312 goto fail; 313 } 314 315 update_max_chunk_size(s, i, &ds->max_compressed_size, 316 &ds->max_sectors_per_chunk); 317 offset += 40; 318 } 319 s->n_chunks += chunk_count; 320 return 0; 321 322 fail: 323 return ret; 324 } 325 326 static int dmg_read_resource_fork(BlockDriverState *bs, DmgHeaderState *ds, 327 uint64_t info_begin, uint64_t info_length) 328 { 329 BDRVDMGState *s = bs->opaque; 330 int ret; 331 uint32_t count, rsrc_data_offset; 332 uint8_t *buffer = NULL; 333 uint64_t info_end; 334 uint64_t offset; 335 336 /* read offset from begin of resource fork (info_begin) to resource data */ 337 ret = read_uint32(bs, info_begin, &rsrc_data_offset); 338 if (ret < 0) { 339 goto fail; 340 } else if (rsrc_data_offset > info_length) { 341 ret = -EINVAL; 342 goto fail; 343 } 344 345 /* read length of resource data */ 346 ret = read_uint32(bs, info_begin + 8, &count); 347 if (ret < 0) { 348 goto fail; 349 } else if (count == 0 || rsrc_data_offset + count > info_length) { 350 ret = -EINVAL; 351 goto fail; 352 } 353 354 /* begin of resource data (consisting of one or more resources) */ 355 offset = info_begin + rsrc_data_offset; 356 357 /* end of resource data (there is possibly a following resource map 358 * which will be ignored). */ 359 info_end = offset + count; 360 361 /* read offsets (mish blocks) from one or more resources in resource data */ 362 while (offset < info_end) { 363 /* size of following resource */ 364 ret = read_uint32(bs, offset, &count); 365 if (ret < 0) { 366 goto fail; 367 } else if (count == 0 || count > info_end - offset) { 368 ret = -EINVAL; 369 goto fail; 370 } 371 offset += 4; 372 373 buffer = g_realloc(buffer, count); 374 ret = bdrv_pread(bs->file, offset, count, buffer, 0); 375 if (ret < 0) { 376 goto fail; 377 } 378 379 ret = dmg_read_mish_block(s, ds, buffer, count); 380 if (ret < 0) { 381 goto fail; 382 } 383 /* advance offset by size of resource */ 384 offset += count; 385 } 386 ret = 0; 387 388 fail: 389 g_free(buffer); 390 return ret; 391 } 392 393 static int dmg_read_plist_xml(BlockDriverState *bs, DmgHeaderState *ds, 394 uint64_t info_begin, uint64_t info_length) 395 { 396 BDRVDMGState *s = bs->opaque; 397 int ret; 398 uint8_t *buffer = NULL; 399 char *data_begin, *data_end; 400 401 /* Have at least some length to avoid NULL for g_malloc. Attempt to set a 402 * safe upper cap on the data length. A test sample had a XML length of 403 * about 1 MiB. */ 404 if (info_length == 0 || info_length > 16 * 1024 * 1024) { 405 ret = -EINVAL; 406 goto fail; 407 } 408 409 buffer = g_malloc(info_length + 1); 410 buffer[info_length] = '\0'; 411 ret = bdrv_pread(bs->file, info_begin, info_length, buffer, 0); 412 if (ret < 0) { 413 ret = -EINVAL; 414 goto fail; 415 } 416 417 /* look for <data>...</data>. The data is 284 (0x11c) bytes after base64 418 * decode. The actual data element has 431 (0x1af) bytes which includes tabs 419 * and line feeds. */ 420 data_end = (char *)buffer; 421 while ((data_begin = strstr(data_end, "<data>")) != NULL) { 422 guchar *mish; 423 gsize out_len = 0; 424 425 data_begin += 6; 426 data_end = strstr(data_begin, "</data>"); 427 /* malformed XML? */ 428 if (data_end == NULL) { 429 ret = -EINVAL; 430 goto fail; 431 } 432 *data_end++ = '\0'; 433 mish = g_base64_decode(data_begin, &out_len); 434 ret = dmg_read_mish_block(s, ds, mish, (uint32_t)out_len); 435 g_free(mish); 436 if (ret < 0) { 437 goto fail; 438 } 439 } 440 ret = 0; 441 442 fail: 443 g_free(buffer); 444 return ret; 445 } 446 447 static int dmg_open(BlockDriverState *bs, QDict *options, int flags, 448 Error **errp) 449 { 450 BDRVDMGState *s = bs->opaque; 451 DmgHeaderState ds; 452 uint64_t rsrc_fork_offset, rsrc_fork_length; 453 uint64_t plist_xml_offset, plist_xml_length; 454 int64_t offset; 455 int ret; 456 457 ret = bdrv_apply_auto_read_only(bs, NULL, errp); 458 if (ret < 0) { 459 return ret; 460 } 461 462 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 463 if (ret < 0) { 464 return ret; 465 } 466 /* 467 * NB: if uncompress submodules are absent, 468 * ie block_module_load return value == 0, the function pointers 469 * dmg_uncompress_bz2 and dmg_uncompress_lzfse will be NULL. 470 */ 471 if (block_module_load("dmg-bz2", errp) < 0) { 472 return -EINVAL; 473 } 474 if (block_module_load("dmg-lzfse", errp) < 0) { 475 return -EINVAL; 476 } 477 478 s->n_chunks = 0; 479 s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL; 480 /* used by dmg_read_mish_block to keep track of the current I/O position */ 481 ds.data_fork_offset = 0; 482 ds.max_compressed_size = 1; 483 ds.max_sectors_per_chunk = 1; 484 485 /* locate the UDIF trailer */ 486 offset = dmg_find_koly_offset(bs->file, errp); 487 if (offset < 0) { 488 ret = offset; 489 goto fail; 490 } 491 492 /* offset of data fork (DataForkOffset) */ 493 ret = read_uint64(bs, offset + 0x18, &ds.data_fork_offset); 494 if (ret < 0) { 495 goto fail; 496 } else if (ds.data_fork_offset > offset) { 497 ret = -EINVAL; 498 goto fail; 499 } 500 501 /* offset of resource fork (RsrcForkOffset) */ 502 ret = read_uint64(bs, offset + 0x28, &rsrc_fork_offset); 503 if (ret < 0) { 504 goto fail; 505 } 506 ret = read_uint64(bs, offset + 0x30, &rsrc_fork_length); 507 if (ret < 0) { 508 goto fail; 509 } 510 if (rsrc_fork_offset >= offset || 511 rsrc_fork_length > offset - rsrc_fork_offset) { 512 ret = -EINVAL; 513 goto fail; 514 } 515 /* offset of property list (XMLOffset) */ 516 ret = read_uint64(bs, offset + 0xd8, &plist_xml_offset); 517 if (ret < 0) { 518 goto fail; 519 } 520 ret = read_uint64(bs, offset + 0xe0, &plist_xml_length); 521 if (ret < 0) { 522 goto fail; 523 } 524 if (plist_xml_offset >= offset || 525 plist_xml_length > offset - plist_xml_offset) { 526 ret = -EINVAL; 527 goto fail; 528 } 529 ret = read_uint64(bs, offset + 0x1ec, (uint64_t *)&bs->total_sectors); 530 if (ret < 0) { 531 goto fail; 532 } 533 if (bs->total_sectors < 0) { 534 ret = -EINVAL; 535 goto fail; 536 } 537 if (rsrc_fork_length != 0) { 538 ret = dmg_read_resource_fork(bs, &ds, 539 rsrc_fork_offset, rsrc_fork_length); 540 if (ret < 0) { 541 goto fail; 542 } 543 } else if (plist_xml_length != 0) { 544 ret = dmg_read_plist_xml(bs, &ds, plist_xml_offset, plist_xml_length); 545 if (ret < 0) { 546 goto fail; 547 } 548 } else { 549 ret = -EINVAL; 550 goto fail; 551 } 552 553 /* initialize zlib engine */ 554 s->compressed_chunk = qemu_try_blockalign(bs->file->bs, 555 ds.max_compressed_size + 1); 556 s->uncompressed_chunk = qemu_try_blockalign(bs->file->bs, 557 512 * ds.max_sectors_per_chunk); 558 if (s->compressed_chunk == NULL || s->uncompressed_chunk == NULL) { 559 ret = -ENOMEM; 560 goto fail; 561 } 562 563 if (inflateInit(&s->zstream) != Z_OK) { 564 ret = -EINVAL; 565 goto fail; 566 } 567 568 s->current_chunk = s->n_chunks; 569 570 qemu_co_mutex_init(&s->lock); 571 return 0; 572 573 fail: 574 g_free(s->types); 575 g_free(s->offsets); 576 g_free(s->lengths); 577 g_free(s->sectors); 578 g_free(s->sectorcounts); 579 qemu_vfree(s->compressed_chunk); 580 qemu_vfree(s->uncompressed_chunk); 581 return ret; 582 } 583 584 static void dmg_refresh_limits(BlockDriverState *bs, Error **errp) 585 { 586 bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ 587 } 588 589 static inline int is_sector_in_chunk(BDRVDMGState *s, 590 uint32_t chunk_num, uint64_t sector_num) 591 { 592 if (chunk_num >= s->n_chunks || s->sectors[chunk_num] > sector_num || 593 s->sectors[chunk_num] + s->sectorcounts[chunk_num] <= sector_num) { 594 return 0; 595 } else { 596 return -1; 597 } 598 } 599 600 static inline uint32_t search_chunk(BDRVDMGState *s, uint64_t sector_num) 601 { 602 /* binary search */ 603 uint32_t chunk1 = 0, chunk2 = s->n_chunks, chunk3; 604 while (chunk1 <= chunk2) { 605 chunk3 = (chunk1 + chunk2) / 2; 606 if (s->sectors[chunk3] > sector_num) { 607 if (chunk3 == 0) { 608 goto err; 609 } 610 chunk2 = chunk3 - 1; 611 } else if (s->sectors[chunk3] + s->sectorcounts[chunk3] > sector_num) { 612 return chunk3; 613 } else { 614 chunk1 = chunk3 + 1; 615 } 616 } 617 err: 618 return s->n_chunks; /* error */ 619 } 620 621 static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num) 622 { 623 BDRVDMGState *s = bs->opaque; 624 625 if (!is_sector_in_chunk(s, s->current_chunk, sector_num)) { 626 int ret; 627 uint32_t chunk = search_chunk(s, sector_num); 628 629 if (chunk >= s->n_chunks) { 630 return -1; 631 } 632 633 s->current_chunk = s->n_chunks; 634 switch (s->types[chunk]) { /* block entry type */ 635 case UDZO: { /* zlib compressed */ 636 /* we need to buffer, because only the chunk as whole can be 637 * inflated. */ 638 ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], 639 s->compressed_chunk, 0); 640 if (ret < 0) { 641 return -1; 642 } 643 644 s->zstream.next_in = s->compressed_chunk; 645 s->zstream.avail_in = s->lengths[chunk]; 646 s->zstream.next_out = s->uncompressed_chunk; 647 s->zstream.avail_out = 512 * s->sectorcounts[chunk]; 648 ret = inflateReset(&s->zstream); 649 if (ret != Z_OK) { 650 return -1; 651 } 652 ret = inflate(&s->zstream, Z_FINISH); 653 if (ret != Z_STREAM_END || 654 s->zstream.total_out != 512 * s->sectorcounts[chunk]) { 655 return -1; 656 } 657 break; } 658 case UDBZ: /* bzip2 compressed */ 659 if (!dmg_uncompress_bz2) { 660 break; 661 } 662 /* we need to buffer, because only the chunk as whole can be 663 * inflated. */ 664 ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], 665 s->compressed_chunk, 0); 666 if (ret < 0) { 667 return -1; 668 } 669 670 ret = dmg_uncompress_bz2((char *)s->compressed_chunk, 671 (unsigned int) s->lengths[chunk], 672 (char *)s->uncompressed_chunk, 673 (unsigned int) 674 (512 * s->sectorcounts[chunk])); 675 if (ret < 0) { 676 return ret; 677 } 678 break; 679 case ULFO: 680 if (!dmg_uncompress_lzfse) { 681 break; 682 } 683 /* we need to buffer, because only the chunk as whole can be 684 * inflated. */ 685 ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], 686 s->compressed_chunk, 0); 687 if (ret < 0) { 688 return -1; 689 } 690 691 ret = dmg_uncompress_lzfse((char *)s->compressed_chunk, 692 (unsigned int) s->lengths[chunk], 693 (char *)s->uncompressed_chunk, 694 (unsigned int) 695 (512 * s->sectorcounts[chunk])); 696 if (ret < 0) { 697 return ret; 698 } 699 break; 700 case UDRW: /* copy */ 701 ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk], 702 s->uncompressed_chunk, 0); 703 if (ret < 0) { 704 return -1; 705 } 706 break; 707 case UDZE: /* zeros */ 708 case UDIG: /* ignore */ 709 /* see dmg_read, it is treated specially. No buffer needs to be 710 * pre-filled, the zeroes can be set directly. */ 711 break; 712 } 713 s->current_chunk = chunk; 714 } 715 return 0; 716 } 717 718 static int coroutine_fn 719 dmg_co_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes, 720 QEMUIOVector *qiov, BdrvRequestFlags flags) 721 { 722 BDRVDMGState *s = bs->opaque; 723 uint64_t sector_num = offset >> BDRV_SECTOR_BITS; 724 int nb_sectors = bytes >> BDRV_SECTOR_BITS; 725 int ret, i; 726 727 assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)); 728 assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE)); 729 730 qemu_co_mutex_lock(&s->lock); 731 732 for (i = 0; i < nb_sectors; i++) { 733 uint32_t sector_offset_in_chunk; 734 void *data; 735 736 if (dmg_read_chunk(bs, sector_num + i) != 0) { 737 ret = -EIO; 738 goto fail; 739 } 740 /* Special case: current chunk is all zeroes. Do not perform a memcpy as 741 * s->uncompressed_chunk may be too small to cover the large all-zeroes 742 * section. dmg_read_chunk is called to find s->current_chunk */ 743 if (s->types[s->current_chunk] == UDZE 744 || s->types[s->current_chunk] == UDIG) { /* all zeroes block entry */ 745 qemu_iovec_memset(qiov, i * 512, 0, 512); 746 continue; 747 } 748 sector_offset_in_chunk = sector_num + i - s->sectors[s->current_chunk]; 749 data = s->uncompressed_chunk + sector_offset_in_chunk * 512; 750 qemu_iovec_from_buf(qiov, i * 512, data, 512); 751 } 752 753 ret = 0; 754 fail: 755 qemu_co_mutex_unlock(&s->lock); 756 return ret; 757 } 758 759 static void dmg_close(BlockDriverState *bs) 760 { 761 BDRVDMGState *s = bs->opaque; 762 763 g_free(s->types); 764 g_free(s->offsets); 765 g_free(s->lengths); 766 g_free(s->sectors); 767 g_free(s->sectorcounts); 768 qemu_vfree(s->compressed_chunk); 769 qemu_vfree(s->uncompressed_chunk); 770 771 inflateEnd(&s->zstream); 772 } 773 774 static BlockDriver bdrv_dmg = { 775 .format_name = "dmg", 776 .instance_size = sizeof(BDRVDMGState), 777 .bdrv_probe = dmg_probe, 778 .bdrv_open = dmg_open, 779 .bdrv_refresh_limits = dmg_refresh_limits, 780 .bdrv_child_perm = bdrv_default_perms, 781 .bdrv_co_preadv = dmg_co_preadv, 782 .bdrv_close = dmg_close, 783 .is_format = true, 784 }; 785 786 static void bdrv_dmg_init(void) 787 { 788 bdrv_register(&bdrv_dmg); 789 } 790 791 block_init(bdrv_dmg_init);