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[Qemu-devel] [PULL 05/16] block/dmg: process a buffer instead of reading
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 05/16] block/dmg: process a buffer instead of reading ints |
Date: |
Fri, 16 Jan 2015 15:37:02 +0000 |
From: Peter Wu <address@hidden>
As the decoded plist XML is not a pointer in the file,
dmg_read_mish_block must be able to process a buffer instead of a file
pointer. Since the full buffer must be processed, let's change the
return value again to just a success flag.
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 | 60 ++++++++++++++++++++++++++++++------------------------------
1 file changed, 30 insertions(+), 30 deletions(-)
diff --git a/block/dmg.c b/block/dmg.c
index 04bae72..4f56227 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -100,6 +100,16 @@ static int read_uint32(BlockDriverState *bs, int64_t
offset, uint32_t *result)
return 0;
}
+static inline uint64_t buff_read_uint64(const uint8_t *buffer, int64_t offset)
+{
+ return be64_to_cpu(*(uint64_t *)&buffer[offset]);
+}
+
+static inline uint32_t buff_read_uint32(const uint8_t *buffer, int64_t offset)
+{
+ return be32_to_cpu(*(uint32_t *)&buffer[offset]);
+}
+
/* Increase max chunk sizes, if necessary. This function is used to calculate
* the buffer sizes needed for compressed/uncompressed chunk I/O.
*/
@@ -182,20 +192,16 @@ typedef struct DmgHeaderState {
uint32_t max_sectors_per_chunk;
} DmgHeaderState;
-static int dmg_read_mish_block(BlockDriverState *bs, DmgHeaderState *ds,
- int64_t offset, uint32_t count)
+static int dmg_read_mish_block(BDRVDMGState *s, DmgHeaderState *ds,
+ uint8_t *buffer, uint32_t count)
{
- BDRVDMGState *s = bs->opaque;
uint32_t type, i;
int ret;
size_t new_size;
uint32_t chunk_count;
+ int64_t offset = 0;
- ret = read_uint32(bs, offset, &type);
- if (ret < 0) {
- goto fail;
- }
-
+ type = buff_read_uint32(buffer, offset);
/* skip data that is not a valid MISH block (invalid magic or too small) */
if (type != 0x6d697368 || count < 244) {
/* assume success for now */
@@ -214,10 +220,7 @@ static int dmg_read_mish_block(BlockDriverState *bs,
DmgHeaderState *ds,
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;
- }
+ s->types[i] = buff_read_uint32(buffer, offset);
offset += 4;
if (s->types[i] != 0x80000005 && s->types[i] != 1 &&
s->types[i] != 2) {
@@ -233,17 +236,11 @@ static int dmg_read_mish_block(BlockDriverState *bs,
DmgHeaderState *ds,
}
offset += 4;
- ret = read_uint64(bs, offset, &s->sectors[i]);
- if (ret < 0) {
- goto fail;
- }
+ s->sectors[i] = buff_read_uint64(buffer, offset);
s->sectors[i] += ds->last_out_offset;
offset += 8;
- ret = read_uint64(bs, offset, &s->sectorcounts[i]);
- if (ret < 0) {
- goto fail;
- }
+ s->sectorcounts[i] = buff_read_uint64(buffer, offset);
offset += 8;
if (s->sectorcounts[i] > DMG_SECTORCOUNTS_MAX) {
@@ -254,17 +251,11 @@ static int dmg_read_mish_block(BlockDriverState *bs,
DmgHeaderState *ds,
goto fail;
}
- ret = read_uint64(bs, offset, &s->offsets[i]);
- if (ret < 0) {
- goto fail;
- }
+ s->offsets[i] = buff_read_uint64(buffer, offset);
s->offsets[i] += ds->last_in_offset;
offset += 8;
- ret = read_uint64(bs, offset, &s->lengths[i]);
- if (ret < 0) {
- goto fail;
- }
+ s->lengths[i] = buff_read_uint64(buffer, offset);
offset += 8;
if (s->lengths[i] > DMG_LENGTHS_MAX) {
@@ -288,8 +279,10 @@ fail:
static int dmg_read_resource_fork(BlockDriverState *bs, DmgHeaderState *ds,
uint64_t info_begin, uint64_t info_length)
{
+ BDRVDMGState *s = bs->opaque;
int ret;
uint32_t count, rsrc_data_offset;
+ uint8_t *buffer = NULL;
uint64_t info_end;
uint64_t offset;
@@ -330,16 +323,23 @@ static int dmg_read_resource_fork(BlockDriverState *bs,
DmgHeaderState *ds,
}
offset += 4;
- ret = dmg_read_mish_block(bs, ds, offset, count);
+ buffer = g_realloc(buffer, count);
+ ret = bdrv_pread(bs->file, offset, buffer, count);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = dmg_read_mish_block(s, ds, buffer, count);
if (ret < 0) {
goto fail;
}
/* advance offset by size of resource */
offset += count;
}
- return 0;
+ ret = 0;
fail:
+ g_free(buffer);
return ret;
}
--
2.1.0
- [Qemu-devel] [PULL 00/16] Block patches, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 01/16] block: add event when disk usage exceeds threshold, Stefan Hajnoczi, 2015/01/16
- [Qemu-devel] [PULL 02/16] block/dmg: properly detect the UDIF trailer, Stefan Hajnoczi, 2015/01/16
- [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 <=
- [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, 2015/01/16
- [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