diff options
author | Peter Wu <peter@lekensteyn.nl> | 2014-12-27 11:38:14 +0100 |
---|---|---|
committer | Peter Wu <peter@lekensteyn.nl> | 2014-12-27 15:39:52 +0100 |
commit | 581ef15e3e5512727242786b2ac4a6f8654ad688 (patch) | |
tree | 89b3a32feb6e888ced41ce1c3846a69ff3f90dd0 | |
parent | c8f5a654dd99cdbdeba271dcf28d2f72a9a03ec5 (diff) | |
download | qemu-581ef15e3e5512727242786b2ac4a6f8654ad688.tar.gz |
block/dmg: fix sector data offset calculation
This patch addresses two issues:
- The data fork offset was not taken into account, resulting in failure
to read an InstallESD.dmg file (5164763151 bytes) which had a
non-zero DataForkOffset field.
- The offset of the previous block ("partition") was unconditionally
added to the current block because older files would start the input
offset of a new block at zero. Newer files (including vlc-2.1.5.dmg,
tuxpaint-0.9.15-macosx.dmg and OS X Yosemite [MAS].dmg) failed in
reads because these files have a continuous input offset.
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
-rw-r--r-- | block/dmg.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/block/dmg.c b/block/dmg.c index 984997f0d9..93b597f21e 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -179,6 +179,7 @@ static int64_t dmg_find_koly_offset(BlockDriverState *file_bs) typedef struct DmgHeaderState { /* used internally by dmg_read_mish_block to remember offsets of blocks * across calls */ + uint64_t data_fork_offset; uint64_t last_in_offset; uint64_t last_out_offset; /* exported for dmg_open */ @@ -194,6 +195,7 @@ static int dmg_read_mish_block(BDRVDMGState *s, DmgHeaderState *ds, size_t new_size; uint32_t chunk_count; int64_t offset = 0; + uint64_t in_offset = ds->data_fork_offset; type = buff_read_uint32(buffer, offset); /* skip data that is not a valid MISH block (invalid magic or too small) */ @@ -246,7 +248,12 @@ static int dmg_read_mish_block(BDRVDMGState *s, DmgHeaderState *ds, } s->offsets[i] = buff_read_uint64(buffer, offset); - s->offsets[i] += ds->last_in_offset; + /* If this offset is below the previous chunk end, then assume that all + * following offsets are after the previous chunks. */ + if (s->offsets[i] + in_offset < ds->last_in_offset) { + in_offset = ds->last_in_offset; + } + s->offsets[i] += in_offset; offset += 8; s->lengths[i] = buff_read_uint64(buffer, offset); @@ -400,6 +407,7 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, bs->read_only = 1; s->n_chunks = 0; s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL; + ds.data_fork_offset = 0; ds.last_in_offset = 0; ds.last_out_offset = 0; ds.max_compressed_size = 1; @@ -412,6 +420,12 @@ static int dmg_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } + /* offset of data fork (DataForkOffset) */ + ret = read_uint64(bs, offset + 0x18, &ds.data_fork_offset); + if (ret < 0) { + goto fail; + } + /* offset of resource fork (RsrcForkOffset) */ ret = read_uint64(bs, offset + 0x28, &rsrc_fork_offset); if (ret < 0) { |