vmxnet3: Use common MAC address tracing macros
[qemu.git] / block / dmg.c
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 "qemu-common.h"
27 #include "block/block_int.h"
28 #include "qemu/bswap.h"
29 #include "qemu/error-report.h"
30 #include "qemu/module.h"
31 #include <zlib.h>
32 #ifdef CONFIG_BZIP2
33 #include <bzlib.h>
34 #endif
35 #include <glib.h>
36
37 enum {
38 /* Limit chunk sizes to prevent unreasonable amounts of memory being used
39 * or truncating when converting to 32-bit types
40 */
41 DMG_LENGTHS_MAX = 64 * 1024 * 1024, /* 64 MB */
42 DMG_SECTORCOUNTS_MAX = DMG_LENGTHS_MAX / 512,
43 };
44
45 typedef struct BDRVDMGState {
46 CoMutex lock;
47 /* each chunk contains a certain number of sectors,
48 * offsets[i] is the offset in the .dmg file,
49 * lengths[i] is the length of the compressed chunk,
50 * sectors[i] is the sector beginning at offsets[i],
51 * sectorcounts[i] is the number of sectors in that chunk,
52 * the sectors array is ordered
53 * 0<=i<n_chunks */
54
55 uint32_t n_chunks;
56 uint32_t* types;
57 uint64_t* offsets;
58 uint64_t* lengths;
59 uint64_t* sectors;
60 uint64_t* sectorcounts;
61 uint32_t current_chunk;
62 uint8_t *compressed_chunk;
63 uint8_t *uncompressed_chunk;
64 z_stream zstream;
65 #ifdef CONFIG_BZIP2
66 bz_stream bzstream;
67 #endif
68 } BDRVDMGState;
69
70 static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename)
71 {
72 int len;
73
74 if (!filename) {
75 return 0;
76 }
77
78 len = strlen(filename);
79 if (len > 4 && !strcmp(filename + len - 4, ".dmg")) {
80 return 2;
81 }
82 return 0;
83 }
84
85 static int read_uint64(BlockDriverState *bs, int64_t offset, uint64_t *result)
86 {
87 uint64_t buffer;
88 int ret;
89
90 ret = bdrv_pread(bs->file->bs, offset, &buffer, 8);
91 if (ret < 0) {
92 return ret;
93 }
94
95 *result = be64_to_cpu(buffer);
96 return 0;
97 }
98
99 static int read_uint32(BlockDriverState *bs, int64_t offset, uint32_t *result)
100 {
101 uint32_t buffer;
102 int ret;
103
104 ret = bdrv_pread(bs->file->bs, offset, &buffer, 4);
105 if (ret < 0) {
106 return ret;
107 }
108
109 *result = be32_to_cpu(buffer);
110 return 0;
111 }
112
113 static inline uint64_t buff_read_uint64(const uint8_t *buffer, int64_t offset)
114 {
115 return be64_to_cpu(*(uint64_t *)&buffer[offset]);
116 }
117
118 static inline uint32_t buff_read_uint32(const uint8_t *buffer, int64_t offset)
119 {
120 return be32_to_cpu(*(uint32_t *)&buffer[offset]);
121 }
122
123 /* Increase max chunk sizes, if necessary. This function is used to calculate
124 * the buffer sizes needed for compressed/uncompressed chunk I/O.
125 */
126 static void update_max_chunk_size(BDRVDMGState *s, uint32_t chunk,
127 uint32_t *max_compressed_size,
128 uint32_t *max_sectors_per_chunk)
129 {
130 uint32_t compressed_size = 0;
131 uint32_t uncompressed_sectors = 0;
132
133 switch (s->types[chunk]) {
134 case 0x80000005: /* zlib compressed */
135 case 0x80000006: /* bzip2 compressed */
136 compressed_size = s->lengths[chunk];
137 uncompressed_sectors = s->sectorcounts[chunk];
138 break;
139 case 1: /* copy */
140 uncompressed_sectors = (s->lengths[chunk] + 511) / 512;
141 break;
142 case 2: /* zero */
143 /* as the all-zeroes block may be large, it is treated specially: the
144 * sector is not copied from a large buffer, a simple memset is used
145 * instead. Therefore uncompressed_sectors does not need to be set. */
146 break;
147 }
148
149 if (compressed_size > *max_compressed_size) {
150 *max_compressed_size = compressed_size;
151 }
152 if (uncompressed_sectors > *max_sectors_per_chunk) {
153 *max_sectors_per_chunk = uncompressed_sectors;
154 }
155 }
156
157 static int64_t dmg_find_koly_offset(BlockDriverState *file_bs, Error **errp)
158 {
159 int64_t length;
160 int64_t offset = 0;
161 uint8_t buffer[515];
162 int i, ret;
163
164 /* bdrv_getlength returns a multiple of block size (512), rounded up. Since
165 * dmg images can have odd sizes, try to look for the "koly" magic which
166 * marks the begin of the UDIF trailer (512 bytes). This magic can be found
167 * in the last 511 bytes of the second-last sector or the first 4 bytes of
168 * the last sector (search space: 515 bytes) */
169 length = bdrv_getlength(file_bs);
170 if (length < 0) {
171 error_setg_errno(errp, -length,
172 "Failed to get file size while reading UDIF trailer");
173 return length;
174 } else if (length < 512) {
175 error_setg(errp, "dmg file must be at least 512 bytes long");
176 return -EINVAL;
177 }
178 if (length > 511 + 512) {
179 offset = length - 511 - 512;
180 }
181 length = length < 515 ? length : 515;
182 ret = bdrv_pread(file_bs, offset, buffer, length);
183 if (ret < 0) {
184 error_setg_errno(errp, -ret, "Failed while reading UDIF trailer");
185 return ret;
186 }
187 for (i = 0; i < length - 3; i++) {
188 if (buffer[i] == 'k' && buffer[i+1] == 'o' &&
189 buffer[i+2] == 'l' && buffer[i+3] == 'y') {
190 return offset + i;
191 }
192 }
193 error_setg(errp, "Could not locate UDIF trailer in dmg file");
194 return -EINVAL;
195 }
196
197 /* used when building the sector table */
198 typedef struct DmgHeaderState {
199 /* used internally by dmg_read_mish_block to remember offsets of blocks
200 * across calls */
201 uint64_t data_fork_offset;
202 /* exported for dmg_open */
203 uint32_t max_compressed_size;
204 uint32_t max_sectors_per_chunk;
205 } DmgHeaderState;
206
207 static bool dmg_is_known_block_type(uint32_t entry_type)
208 {
209 switch (entry_type) {
210 case 0x00000001: /* uncompressed */
211 case 0x00000002: /* zeroes */
212 case 0x80000005: /* zlib */
213 #ifdef CONFIG_BZIP2
214 case 0x80000006: /* bzip2 */
215 #endif
216 return true;
217 default:
218 return false;
219 }
220 }
221
222 static int dmg_read_mish_block(BDRVDMGState *s, DmgHeaderState *ds,
223 uint8_t *buffer, uint32_t count)
224 {
225 uint32_t type, i;
226 int ret;
227 size_t new_size;
228 uint32_t chunk_count;
229 int64_t offset = 0;
230 uint64_t data_offset;
231 uint64_t in_offset = ds->data_fork_offset;
232 uint64_t out_offset;
233
234 type = buff_read_uint32(buffer, offset);
235 /* skip data that is not a valid MISH block (invalid magic or too small) */
236 if (type != 0x6d697368 || count < 244) {
237 /* assume success for now */
238 return 0;
239 }
240
241 /* chunk offsets are relative to this sector number */
242 out_offset = buff_read_uint64(buffer, offset + 8);
243
244 /* location in data fork for (compressed) blob (in bytes) */
245 data_offset = buff_read_uint64(buffer, offset + 0x18);
246 in_offset += data_offset;
247
248 /* move to begin of chunk entries */
249 offset += 204;
250
251 chunk_count = (count - 204) / 40;
252 new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
253 s->types = g_realloc(s->types, new_size / 2);
254 s->offsets = g_realloc(s->offsets, new_size);
255 s->lengths = g_realloc(s->lengths, new_size);
256 s->sectors = g_realloc(s->sectors, new_size);
257 s->sectorcounts = g_realloc(s->sectorcounts, new_size);
258
259 for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) {
260 s->types[i] = buff_read_uint32(buffer, offset);
261 if (!dmg_is_known_block_type(s->types[i])) {
262 chunk_count--;
263 i--;
264 offset += 40;
265 continue;
266 }
267
268 /* sector number */
269 s->sectors[i] = buff_read_uint64(buffer, offset + 8);
270 s->sectors[i] += out_offset;
271
272 /* sector count */
273 s->sectorcounts[i] = buff_read_uint64(buffer, offset + 0x10);
274
275 /* all-zeroes sector (type 2) does not need to be "uncompressed" and can
276 * therefore be unbounded. */
277 if (s->types[i] != 2 && s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) {
278 error_report("sector count %" PRIu64 " for chunk %" PRIu32
279 " is larger than max (%u)",
280 s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX);
281 ret = -EINVAL;
282 goto fail;
283 }
284
285 /* offset in (compressed) data fork */
286 s->offsets[i] = buff_read_uint64(buffer, offset + 0x18);
287 s->offsets[i] += in_offset;
288
289 /* length in (compressed) data fork */
290 s->lengths[i] = buff_read_uint64(buffer, offset + 0x20);
291
292 if (s->lengths[i] > DMG_LENGTHS_MAX) {
293 error_report("length %" PRIu64 " for chunk %" PRIu32
294 " is larger than max (%u)",
295 s->lengths[i], i, DMG_LENGTHS_MAX);
296 ret = -EINVAL;
297 goto fail;
298 }
299
300 update_max_chunk_size(s, i, &ds->max_compressed_size,
301 &ds->max_sectors_per_chunk);
302 offset += 40;
303 }
304 s->n_chunks += chunk_count;
305 return 0;
306
307 fail:
308 return ret;
309 }
310
311 static int dmg_read_resource_fork(BlockDriverState *bs, DmgHeaderState *ds,
312 uint64_t info_begin, uint64_t info_length)
313 {
314 BDRVDMGState *s = bs->opaque;
315 int ret;
316 uint32_t count, rsrc_data_offset;
317 uint8_t *buffer = NULL;
318 uint64_t info_end;
319 uint64_t offset;
320
321 /* read offset from begin of resource fork (info_begin) to resource data */
322 ret = read_uint32(bs, info_begin, &rsrc_data_offset);
323 if (ret < 0) {
324 goto fail;
325 } else if (rsrc_data_offset > info_length) {
326 ret = -EINVAL;
327 goto fail;
328 }
329
330 /* read length of resource data */
331 ret = read_uint32(bs, info_begin + 8, &count);
332 if (ret < 0) {
333 goto fail;
334 } else if (count == 0 || rsrc_data_offset + count > info_length) {
335 ret = -EINVAL;
336 goto fail;
337 }
338
339 /* begin of resource data (consisting of one or more resources) */
340 offset = info_begin + rsrc_data_offset;
341
342 /* end of resource data (there is possibly a following resource map
343 * which will be ignored). */
344 info_end = offset + count;
345
346 /* read offsets (mish blocks) from one or more resources in resource data */
347 while (offset < info_end) {
348 /* size of following resource */
349 ret = read_uint32(bs, offset, &count);
350 if (ret < 0) {
351 goto fail;
352 } else if (count == 0 || count > info_end - offset) {
353 ret = -EINVAL;
354 goto fail;
355 }
356 offset += 4;
357
358 buffer = g_realloc(buffer, count);
359 ret = bdrv_pread(bs->file->bs, offset, buffer, count);
360 if (ret < 0) {
361 goto fail;
362 }
363
364 ret = dmg_read_mish_block(s, ds, buffer, count);
365 if (ret < 0) {
366 goto fail;
367 }
368 /* advance offset by size of resource */
369 offset += count;
370 }
371 ret = 0;
372
373 fail:
374 g_free(buffer);
375 return ret;
376 }
377
378 static int dmg_read_plist_xml(BlockDriverState *bs, DmgHeaderState *ds,
379 uint64_t info_begin, uint64_t info_length)
380 {
381 BDRVDMGState *s = bs->opaque;
382 int ret;
383 uint8_t *buffer = NULL;
384 char *data_begin, *data_end;
385
386 /* Have at least some length to avoid NULL for g_malloc. Attempt to set a
387 * safe upper cap on the data length. A test sample had a XML length of
388 * about 1 MiB. */
389 if (info_length == 0 || info_length > 16 * 1024 * 1024) {
390 ret = -EINVAL;
391 goto fail;
392 }
393
394 buffer = g_malloc(info_length + 1);
395 buffer[info_length] = '\0';
396 ret = bdrv_pread(bs->file->bs, info_begin, buffer, info_length);
397 if (ret != info_length) {
398 ret = -EINVAL;
399 goto fail;
400 }
401
402 /* look for <data>...</data>. The data is 284 (0x11c) bytes after base64
403 * decode. The actual data element has 431 (0x1af) bytes which includes tabs
404 * and line feeds. */
405 data_end = (char *)buffer;
406 while ((data_begin = strstr(data_end, "<data>")) != NULL) {
407 guchar *mish;
408 gsize out_len = 0;
409
410 data_begin += 6;
411 data_end = strstr(data_begin, "</data>");
412 /* malformed XML? */
413 if (data_end == NULL) {
414 ret = -EINVAL;
415 goto fail;
416 }
417 *data_end++ = '\0';
418 mish = g_base64_decode(data_begin, &out_len);
419 ret = dmg_read_mish_block(s, ds, mish, (uint32_t)out_len);
420 g_free(mish);
421 if (ret < 0) {
422 goto fail;
423 }
424 }
425 ret = 0;
426
427 fail:
428 g_free(buffer);
429 return ret;
430 }
431
432 static int dmg_open(BlockDriverState *bs, QDict *options, int flags,
433 Error **errp)
434 {
435 BDRVDMGState *s = bs->opaque;
436 DmgHeaderState ds;
437 uint64_t rsrc_fork_offset, rsrc_fork_length;
438 uint64_t plist_xml_offset, plist_xml_length;
439 int64_t offset;
440 int ret;
441
442 bs->read_only = 1;
443 bs->request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O supported */
444
445 s->n_chunks = 0;
446 s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
447 /* used by dmg_read_mish_block to keep track of the current I/O position */
448 ds.data_fork_offset = 0;
449 ds.max_compressed_size = 1;
450 ds.max_sectors_per_chunk = 1;
451
452 /* locate the UDIF trailer */
453 offset = dmg_find_koly_offset(bs->file->bs, errp);
454 if (offset < 0) {
455 ret = offset;
456 goto fail;
457 }
458
459 /* offset of data fork (DataForkOffset) */
460 ret = read_uint64(bs, offset + 0x18, &ds.data_fork_offset);
461 if (ret < 0) {
462 goto fail;
463 } else if (ds.data_fork_offset > offset) {
464 ret = -EINVAL;
465 goto fail;
466 }
467
468 /* offset of resource fork (RsrcForkOffset) */
469 ret = read_uint64(bs, offset + 0x28, &rsrc_fork_offset);
470 if (ret < 0) {
471 goto fail;
472 }
473 ret = read_uint64(bs, offset + 0x30, &rsrc_fork_length);
474 if (ret < 0) {
475 goto fail;
476 }
477 if (rsrc_fork_offset >= offset ||
478 rsrc_fork_length > offset - rsrc_fork_offset) {
479 ret = -EINVAL;
480 goto fail;
481 }
482 /* offset of property list (XMLOffset) */
483 ret = read_uint64(bs, offset + 0xd8, &plist_xml_offset);
484 if (ret < 0) {
485 goto fail;
486 }
487 ret = read_uint64(bs, offset + 0xe0, &plist_xml_length);
488 if (ret < 0) {
489 goto fail;
490 }
491 if (plist_xml_offset >= offset ||
492 plist_xml_length > offset - plist_xml_offset) {
493 ret = -EINVAL;
494 goto fail;
495 }
496 ret = read_uint64(bs, offset + 0x1ec, (uint64_t *)&bs->total_sectors);
497 if (ret < 0) {
498 goto fail;
499 }
500 if (bs->total_sectors < 0) {
501 ret = -EINVAL;
502 goto fail;
503 }
504 if (rsrc_fork_length != 0) {
505 ret = dmg_read_resource_fork(bs, &ds,
506 rsrc_fork_offset, rsrc_fork_length);
507 if (ret < 0) {
508 goto fail;
509 }
510 } else if (plist_xml_length != 0) {
511 ret = dmg_read_plist_xml(bs, &ds, plist_xml_offset, plist_xml_length);
512 if (ret < 0) {
513 goto fail;
514 }
515 } else {
516 ret = -EINVAL;
517 goto fail;
518 }
519
520 /* initialize zlib engine */
521 s->compressed_chunk = qemu_try_blockalign(bs->file->bs,
522 ds.max_compressed_size + 1);
523 s->uncompressed_chunk = qemu_try_blockalign(bs->file->bs,
524 512 * ds.max_sectors_per_chunk);
525 if (s->compressed_chunk == NULL || s->uncompressed_chunk == NULL) {
526 ret = -ENOMEM;
527 goto fail;
528 }
529
530 if (inflateInit(&s->zstream) != Z_OK) {
531 ret = -EINVAL;
532 goto fail;
533 }
534
535 s->current_chunk = s->n_chunks;
536
537 qemu_co_mutex_init(&s->lock);
538 return 0;
539
540 fail:
541 g_free(s->types);
542 g_free(s->offsets);
543 g_free(s->lengths);
544 g_free(s->sectors);
545 g_free(s->sectorcounts);
546 qemu_vfree(s->compressed_chunk);
547 qemu_vfree(s->uncompressed_chunk);
548 return ret;
549 }
550
551 static inline int is_sector_in_chunk(BDRVDMGState* s,
552 uint32_t chunk_num, uint64_t sector_num)
553 {
554 if (chunk_num >= s->n_chunks || s->sectors[chunk_num] > sector_num ||
555 s->sectors[chunk_num] + s->sectorcounts[chunk_num] <= sector_num) {
556 return 0;
557 } else {
558 return -1;
559 }
560 }
561
562 static inline uint32_t search_chunk(BDRVDMGState *s, uint64_t sector_num)
563 {
564 /* binary search */
565 uint32_t chunk1 = 0, chunk2 = s->n_chunks, chunk3;
566 while (chunk1 != chunk2) {
567 chunk3 = (chunk1 + chunk2) / 2;
568 if (s->sectors[chunk3] > sector_num) {
569 chunk2 = chunk3;
570 } else if (s->sectors[chunk3] + s->sectorcounts[chunk3] > sector_num) {
571 return chunk3;
572 } else {
573 chunk1 = chunk3;
574 }
575 }
576 return s->n_chunks; /* error */
577 }
578
579 static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
580 {
581 BDRVDMGState *s = bs->opaque;
582
583 if (!is_sector_in_chunk(s, s->current_chunk, sector_num)) {
584 int ret;
585 uint32_t chunk = search_chunk(s, sector_num);
586 #ifdef CONFIG_BZIP2
587 uint64_t total_out;
588 #endif
589
590 if (chunk >= s->n_chunks) {
591 return -1;
592 }
593
594 s->current_chunk = s->n_chunks;
595 switch (s->types[chunk]) { /* block entry type */
596 case 0x80000005: { /* zlib compressed */
597 /* we need to buffer, because only the chunk as whole can be
598 * inflated. */
599 ret = bdrv_pread(bs->file->bs, s->offsets[chunk],
600 s->compressed_chunk, s->lengths[chunk]);
601 if (ret != s->lengths[chunk]) {
602 return -1;
603 }
604
605 s->zstream.next_in = s->compressed_chunk;
606 s->zstream.avail_in = s->lengths[chunk];
607 s->zstream.next_out = s->uncompressed_chunk;
608 s->zstream.avail_out = 512 * s->sectorcounts[chunk];
609 ret = inflateReset(&s->zstream);
610 if (ret != Z_OK) {
611 return -1;
612 }
613 ret = inflate(&s->zstream, Z_FINISH);
614 if (ret != Z_STREAM_END ||
615 s->zstream.total_out != 512 * s->sectorcounts[chunk]) {
616 return -1;
617 }
618 break; }
619 #ifdef CONFIG_BZIP2
620 case 0x80000006: /* bzip2 compressed */
621 /* we need to buffer, because only the chunk as whole can be
622 * inflated. */
623 ret = bdrv_pread(bs->file->bs, s->offsets[chunk],
624 s->compressed_chunk, s->lengths[chunk]);
625 if (ret != s->lengths[chunk]) {
626 return -1;
627 }
628
629 ret = BZ2_bzDecompressInit(&s->bzstream, 0, 0);
630 if (ret != BZ_OK) {
631 return -1;
632 }
633 s->bzstream.next_in = (char *)s->compressed_chunk;
634 s->bzstream.avail_in = (unsigned int) s->lengths[chunk];
635 s->bzstream.next_out = (char *)s->uncompressed_chunk;
636 s->bzstream.avail_out = (unsigned int) 512 * s->sectorcounts[chunk];
637 ret = BZ2_bzDecompress(&s->bzstream);
638 total_out = ((uint64_t)s->bzstream.total_out_hi32 << 32) +
639 s->bzstream.total_out_lo32;
640 BZ2_bzDecompressEnd(&s->bzstream);
641 if (ret != BZ_STREAM_END ||
642 total_out != 512 * s->sectorcounts[chunk]) {
643 return -1;
644 }
645 break;
646 #endif /* CONFIG_BZIP2 */
647 case 1: /* copy */
648 ret = bdrv_pread(bs->file->bs, s->offsets[chunk],
649 s->uncompressed_chunk, s->lengths[chunk]);
650 if (ret != s->lengths[chunk]) {
651 return -1;
652 }
653 break;
654 case 2: /* zero */
655 /* see dmg_read, it is treated specially. No buffer needs to be
656 * pre-filled, the zeroes can be set directly. */
657 break;
658 }
659 s->current_chunk = chunk;
660 }
661 return 0;
662 }
663
664 static int coroutine_fn
665 dmg_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
666 QEMUIOVector *qiov, int flags)
667 {
668 BDRVDMGState *s = bs->opaque;
669 uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
670 int nb_sectors = bytes >> BDRV_SECTOR_BITS;
671 int ret, i;
672
673 assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
674 assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
675
676 qemu_co_mutex_lock(&s->lock);
677
678 for (i = 0; i < nb_sectors; i++) {
679 uint32_t sector_offset_in_chunk;
680 void *data;
681
682 if (dmg_read_chunk(bs, sector_num + i) != 0) {
683 ret = -EIO;
684 goto fail;
685 }
686 /* Special case: current chunk is all zeroes. Do not perform a memcpy as
687 * s->uncompressed_chunk may be too small to cover the large all-zeroes
688 * section. dmg_read_chunk is called to find s->current_chunk */
689 if (s->types[s->current_chunk] == 2) { /* all zeroes block entry */
690 qemu_iovec_memset(qiov, i * 512, 0, 512);
691 continue;
692 }
693 sector_offset_in_chunk = sector_num + i - s->sectors[s->current_chunk];
694 data = s->uncompressed_chunk + sector_offset_in_chunk * 512;
695 qemu_iovec_from_buf(qiov, i * 512, data, 512);
696 }
697
698 ret = 0;
699 fail:
700 qemu_co_mutex_unlock(&s->lock);
701 return ret;
702 }
703
704 static void dmg_close(BlockDriverState *bs)
705 {
706 BDRVDMGState *s = bs->opaque;
707
708 g_free(s->types);
709 g_free(s->offsets);
710 g_free(s->lengths);
711 g_free(s->sectors);
712 g_free(s->sectorcounts);
713 qemu_vfree(s->compressed_chunk);
714 qemu_vfree(s->uncompressed_chunk);
715
716 inflateEnd(&s->zstream);
717 }
718
719 static BlockDriver bdrv_dmg = {
720 .format_name = "dmg",
721 .instance_size = sizeof(BDRVDMGState),
722 .bdrv_probe = dmg_probe,
723 .bdrv_open = dmg_open,
724 .bdrv_co_preadv = dmg_co_preadv,
725 .bdrv_close = dmg_close,
726 };
727
728 static void bdrv_dmg_init(void)
729 {
730 bdrv_register(&bdrv_dmg);
731 }
732
733 block_init(bdrv_dmg_init);