[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 11/16] block/dmg: factor out block type check
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 11/16] block/dmg: factor out block type check |
Date: |
Fri, 16 Jan 2015 15:37:08 +0000 |
From: Peter Wu <address@hidden>
In preparation for adding bzip2 support, split the type check into a
separate function. Make all offsets relative to the begin of a chunk
such that it is easier to recognize the position without having to
add up all offsets. Some comments are added to describe the fields.
There is no functional change.
Signed-off-by: Peter Wu <address@hidden>
Reviewed-by: John Snow <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
block/dmg.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)
diff --git a/block/dmg.c b/block/dmg.c
index 0f278c8..2bb7078 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -192,6 +192,18 @@ typedef struct DmgHeaderState {
uint32_t max_sectors_per_chunk;
} DmgHeaderState;
+static bool dmg_is_known_block_type(uint32_t entry_type)
+{
+ switch (entry_type) {
+ case 0x00000001: /* uncompressed */
+ case 0x00000002: /* zeroes */
+ case 0x80000005: /* zlib */
+ return true;
+ default:
+ return false;
+ }
+}
+
static int dmg_read_mish_block(BDRVDMGState *s, DmgHeaderState *ds,
uint8_t *buffer, uint32_t count)
{
@@ -231,22 +243,19 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
for (i = s->n_chunks; i < s->n_chunks + chunk_count; i++) {
s->types[i] = buff_read_uint32(buffer, offset);
- offset += 4;
- if (s->types[i] != 0x80000005 && s->types[i] != 1 &&
- s->types[i] != 2) {
+ if (!dmg_is_known_block_type(s->types[i])) {
chunk_count--;
i--;
- offset += 36;
+ offset += 40;
continue;
}
- offset += 4;
- s->sectors[i] = buff_read_uint64(buffer, offset);
+ /* sector number */
+ s->sectors[i] = buff_read_uint64(buffer, offset + 8);
s->sectors[i] += out_offset;
- offset += 8;
- s->sectorcounts[i] = buff_read_uint64(buffer, offset);
- offset += 8;
+ /* sector count */
+ s->sectorcounts[i] = buff_read_uint64(buffer, offset + 0x10);
if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) {
error_report("sector count %" PRIu64 " for chunk %" PRIu32
@@ -256,12 +265,12 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
goto fail;
}
- s->offsets[i] = buff_read_uint64(buffer, offset);
+ /* offset in (compressed) data fork */
+ s->offsets[i] = buff_read_uint64(buffer, offset + 0x18);
s->offsets[i] += in_offset;
- offset += 8;
- s->lengths[i] = buff_read_uint64(buffer, offset);
- offset += 8;
+ /* length in (compressed) data fork */
+ s->lengths[i] = buff_read_uint64(buffer, offset + 0x20);
if (s->lengths[i] > DMG_LENGTHS_MAX) {
error_report("length %" PRIu64 " for chunk %" PRIu32
@@ -273,6 +282,7 @@ static int dmg_read_mish_block(BDRVDMGState *s,
DmgHeaderState *ds,
update_max_chunk_size(s, i, &ds->max_compressed_size,
&ds->max_sectors_per_chunk);
+ offset += 40;
}
s->n_chunks += chunk_count;
return 0;
--
2.1.0
- [Qemu-devel] [PULL 03/16] block/dmg: extract mish block decoding functionality, (continued)
- [Qemu-devel] [PULL 03/16] block/dmg: extract mish block decoding functionality, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 04/16] block/dmg: extract processing of resource forks, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 07/16] block/dmg: process XML plists, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 05/16] block/dmg: process a buffer instead of reading ints, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 06/16] block/dmg: validate chunk size to avoid overflow, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 10/16] block/dmg: use SectorNumber from BLKX header, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 08/16] block/dmg: set virtual size to a non-zero value, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 12/16] block/dmg: support bzip2 block entry types, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 09/16] block/dmg: fix sector data offset calculation, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 14/16] qed: check for header size overflow, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 11/16] block/dmg: factor out block type check,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL 15/16] qemu-iotests: add 116 invalid QED input file tests, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 13/16] block/dmg: improve zeroes handling, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 16/16] qemu-iotests: Fix supported_oses check, Stefan Hajnoczi, 2015/01/16
- Re: [Qemu-devel] [PULL 00/16] Block patches, Peter Maydell, 2015/01/16