diff options
| -rw-r--r-- | block/dmg.c | 228 |
1 files changed, 133 insertions, 95 deletions
diff --git a/block/dmg.c b/block/dmg.c index cdad28f..c571ac9 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -171,19 +171,138 @@ static int64_t dmg_find_koly_offset(BlockDriverState *file_bs, Error **errp) return -EINVAL; } +/* used when building the sector table */ +typedef struct DmgHeaderState { + /* used internally by dmg_read_mish_block to remember offsets of blocks + * across calls */ + uint64_t last_in_offset; + uint64_t last_out_offset; + /* exported for dmg_open */ + uint32_t max_compressed_size; + uint32_t max_sectors_per_chunk; +} DmgHeaderState; + +static int dmg_read_mish_block(BlockDriverState *bs, DmgHeaderState *ds, + int64_t offset, uint32_t count) +{ + BDRVDMGState *s = bs->opaque; + uint32_t type, i; + int ret; + size_t new_size; + uint32_t chunk_count; + + ret = read_uint32(bs, offset, &type); + if (ret < 0) { + goto fail; + } + + /* skip data that is not a valid MISH block (invalid magic or too small) */ + if (type != 0x6d697368 || count < 244) { + /* assume success for now */ + return 0; + } + + offset += 4; + offset += 200; + + chunk_count = (count - 204) / 40; + new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count); + s->types = g_realloc(s->types, new_size / 2); + s->offsets = g_realloc(s->offsets, new_size); + s->lengths = g_realloc(s->lengths, new_size); + s->sectors = g_realloc(s->sectors, new_size); + s->sectorcounts = g_realloc(s->sectorcounts, new_size); + + for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) { + ret = read_uint32(bs, offset, &s->types[i]); + if (ret < 0) { + goto fail; + } + offset += 4; + if (s->types[i] != 0x80000005 && s->types[i] != 1 && + s->types[i] != 2) { + if (s->types[i] == 0xffffffff && i > 0) { + ds->last_in_offset = s->offsets[i - 1] + s->lengths[i - 1]; + ds->last_out_offset = s->sectors[i - 1] + + s->sectorcounts[i - 1]; + } + chunk_count--; + i--; + offset += 36; + continue; + } + offset += 4; + + ret = read_uint64(bs, offset, &s->sectors[i]); + if (ret < 0) { + goto fail; + } + s->sectors[i] += ds->last_out_offset; + offset += 8; + + ret = read_uint64(bs, offset, &s->sectorcounts[i]); + if (ret < 0) { + goto fail; + } + offset += 8; + + if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) { + error_report("sector count %" PRIu64 " for chunk %" PRIu32 + " is larger than max (%u)", + s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX); + ret = -EINVAL; + goto fail; + } + + ret = read_uint64(bs, offset, &s->offsets[i]); + if (ret < 0) { + goto fail; + } + s->offsets[i] += ds->last_in_offset; + offset += 8; + + ret = read_uint64(bs, offset, &s->lengths[i]); + if (ret < 0) { + goto fail; + } + offset += 8; + + if (s->lengths[i] > DMG_LENGTHS_MAX) { + error_report("length %" PRIu64 " for chunk %" PRIu32 + " is larger than max (%u)", + s->lengths[i], i, DMG_LENGTHS_MAX); + ret = -EINVAL; + goto fail; + } + + update_max_chunk_size(s, i, &ds->max_compressed_size, + &ds->max_sectors_per_chunk); + } + s->n_chunks += chunk_count; + return 0; + +fail: + return ret; +} + static int dmg_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVDMGState *s = bs->opaque; - uint64_t info_begin, info_end, last_in_offset, last_out_offset; - uint32_t count, tmp; - uint32_t max_compressed_size = 1, max_sectors_per_chunk = 1, i; + DmgHeaderState ds; + uint64_t info_begin, info_end; + uint32_t count, rsrc_data_offset; int64_t offset; int ret; bs->read_only = 1; s->n_chunks = 0; s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL; + /* used by dmg_read_mish_block to keep track of the current I/O position */ + ds.last_in_offset = 0; + ds.last_out_offset = 0; + ds.max_compressed_size = 1; + ds.max_sectors_per_chunk = 1; /* locate the UDIF trailer */ offset = dmg_find_koly_offset(bs->file, errp); @@ -200,10 +319,10 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - ret = read_uint32(bs, info_begin, &tmp); + ret = read_uint32(bs, info_begin, &rsrc_data_offset); if (ret < 0) { goto fail; - } else if (tmp != 0x100) { + } else if (rsrc_data_offset != 0x100) { ret = -EINVAL; goto fail; } @@ -215,15 +334,15 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; goto fail; } + /* end of resource data, ignoring the following resource map */ info_end = info_begin + count; + /* begin of resource data (consisting of one or more resources) */ offset = info_begin + 0x100; - /* read offsets */ - last_in_offset = last_out_offset = 0; + /* read offsets (mish blocks) from one or more resources in resource data */ while (offset < info_end) { - uint32_t type; - + /* size of following resource */ ret = read_uint32(bs, offset, &count); if (ret < 0) { goto fail; @@ -233,100 +352,19 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, } offset += 4; - ret = read_uint32(bs, offset, &type); + ret = dmg_read_mish_block(bs, &ds, offset, count); if (ret < 0) { goto fail; } - - if (type == 0x6d697368 && count >= 244) { - size_t new_size; - uint32_t chunk_count; - - offset += 4; - offset += 200; - - chunk_count = (count - 204) / 40; - new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count); - s->types = g_realloc(s->types, new_size / 2); - s->offsets = g_realloc(s->offsets, new_size); - s->lengths = g_realloc(s->lengths, new_size); - s->sectors = g_realloc(s->sectors, new_size); - s->sectorcounts = g_realloc(s->sectorcounts, new_size); - - for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) { - ret = read_uint32(bs, offset, &s->types[i]); - if (ret < 0) { - goto fail; - } - offset += 4; - if (s->types[i] != 0x80000005 && s->types[i] != 1 && - s->types[i] != 2) { - if (s->types[i] == 0xffffffff && i > 0) { - last_in_offset = s->offsets[i - 1] + s->lengths[i - 1]; - last_out_offset = s->sectors[i - 1] + - s->sectorcounts[i - 1]; - } - chunk_count--; - i--; - offset += 36; - continue; - } - offset += 4; - - ret = read_uint64(bs, offset, &s->sectors[i]); - if (ret < 0) { - goto fail; - } - s->sectors[i] += last_out_offset; - offset += 8; - - ret = read_uint64(bs, offset, &s->sectorcounts[i]); - if (ret < 0) { - goto fail; - } - offset += 8; - - if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) { - error_report("sector count %" PRIu64 " for chunk %" PRIu32 - " is larger than max (%u)", - s->sectorcounts[i], i, DMG_SECTORCOUNTS_MAX); - ret = -EINVAL; - goto fail; - } - - ret = read_uint64(bs, offset, &s->offsets[i]); - if (ret < 0) { - goto fail; - } - s->offsets[i] += last_in_offset; - offset += 8; - - ret = read_uint64(bs, offset, &s->lengths[i]); - if (ret < 0) { - goto fail; - } - offset += 8; - - if (s->lengths[i] > DMG_LENGTHS_MAX) { - error_report("length %" PRIu64 " for chunk %" PRIu32 - " is larger than max (%u)", - s->lengths[i], i, DMG_LENGTHS_MAX); - ret = -EINVAL; - goto fail; - } - - update_max_chunk_size(s, i, &max_compressed_size, - &max_sectors_per_chunk); - } - s->n_chunks += chunk_count; - } + /* advance offset by size of resource */ + offset += count; } /* initialize zlib engine */ s->compressed_chunk = qemu_try_blockalign(bs->file, - max_compressed_size + 1); + ds.max_compressed_size + 1); s->uncompressed_chunk = qemu_try_blockalign(bs->file, - 512 * max_sectors_per_chunk); + 512 * ds.max_sectors_per_chunk); if (s->compressed_chunk == NULL || s->uncompressed_chunk == NULL) { ret = -ENOMEM; goto fail; 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