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-rw-r--r--block/dmg.c121
1 files changed, 66 insertions, 55 deletions
diff --git a/block/dmg.c b/block/dmg.c
index 262560f..a3c815b 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -28,8 +28,6 @@
#include <zlib.h>
typedef struct BDRVDMGState {
- int fd;
-
/* each chunk contains a certain number of sectors,
* offsets[i] is the offset in the .dmg file,
* lengths[i] is the length of the compressed chunk,
@@ -58,72 +56,75 @@ static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename)
return 0;
}
-static off_t read_off(int fd)
+static off_t read_off(BlockDriverState *bs, int64_t offset)
{
uint64_t buffer;
- if(read(fd,&buffer,8)<8)
+ if (bdrv_pread(bs->file, offset, &buffer, 8) < 8)
return 0;
return be64_to_cpu(buffer);
}
-static off_t read_uint32(int fd)
+static off_t read_uint32(BlockDriverState *bs, int64_t offset)
{
uint32_t buffer;
- if(read(fd,&buffer,4)<4)
+ if (bdrv_pread(bs->file, offset, &buffer, 4) < 4)
return 0;
return be32_to_cpu(buffer);
}
-static int dmg_open(BlockDriverState *bs, const char *filename, int flags)
+static int dmg_open(BlockDriverState *bs, int flags)
{
BDRVDMGState *s = bs->opaque;
off_t info_begin,info_end,last_in_offset,last_out_offset;
uint32_t count;
uint32_t max_compressed_size=1,max_sectors_per_chunk=1,i;
+ int64_t offset;
- s->fd = open(filename, O_RDONLY | O_BINARY);
- if (s->fd < 0)
- return -errno;
bs->read_only = 1;
s->n_chunks = 0;
s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
/* read offset of info blocks */
- if(lseek(s->fd,-0x1d8,SEEK_END)<0) {
-dmg_close:
- close(s->fd);
- /* open raw instead */
- bs->drv=bdrv_find_format("raw");
- return bs->drv->bdrv_open(bs, filename, flags);
+ offset = bdrv_getlength(bs->file);
+ if (offset < 0) {
+ goto fail;
+ }
+ offset -= 0x1d8;
+
+ info_begin = read_off(bs, offset);
+ if (info_begin == 0) {
+ goto fail;
+ }
+
+ if (read_uint32(bs, info_begin) != 0x100) {
+ goto fail;
}
- info_begin=read_off(s->fd);
- if(info_begin==0)
- goto dmg_close;
- if(lseek(s->fd,info_begin,SEEK_SET)<0)
- goto dmg_close;
- if(read_uint32(s->fd)!=0x100)
- goto dmg_close;
- if((count = read_uint32(s->fd))==0)
- goto dmg_close;
- info_end = info_begin+count;
- if(lseek(s->fd,0xf8,SEEK_CUR)<0)
- goto dmg_close;
+
+ count = read_uint32(bs, info_begin + 4);
+ if (count == 0) {
+ goto fail;
+ }
+ info_end = info_begin + count;
+
+ offset = info_begin + 0x100;
/* read offsets */
last_in_offset = last_out_offset = 0;
- while(lseek(s->fd,0,SEEK_CUR)<info_end) {
+ while (offset < info_end) {
uint32_t type;
- count = read_uint32(s->fd);
+ count = read_uint32(bs, offset);
if(count==0)
- goto dmg_close;
- type = read_uint32(s->fd);
- if(type!=0x6d697368 || count<244)
- lseek(s->fd,count-4,SEEK_CUR);
- else {
+ goto fail;
+ offset += 4;
+
+ type = read_uint32(bs, offset);
+ if (type == 0x6d697368 && count >= 244) {
int new_size, chunk_count;
- if(lseek(s->fd,200,SEEK_CUR)<0)
- goto dmg_close;
+
+ offset += 4;
+ offset += 200;
+
chunk_count = (count-204)/40;
new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
s->types = qemu_realloc(s->types, new_size/2);
@@ -133,7 +134,8 @@ dmg_close:
s->sectorcounts = qemu_realloc(s->sectorcounts, new_size);
for(i=s->n_chunks;i<s->n_chunks+chunk_count;i++) {
- s->types[i] = read_uint32(s->fd);
+ s->types[i] = read_uint32(bs, offset);
+ offset += 4;
if(s->types[i]!=0x80000005 && s->types[i]!=1 && s->types[i]!=2) {
if(s->types[i]==0xffffffff) {
last_in_offset = s->offsets[i-1]+s->lengths[i-1];
@@ -141,15 +143,23 @@ dmg_close:
}
chunk_count--;
i--;
- if(lseek(s->fd,36,SEEK_CUR)<0)
- goto dmg_close;
+ offset += 36;
continue;
}
- read_uint32(s->fd);
- s->sectors[i] = last_out_offset+read_off(s->fd);
- s->sectorcounts[i] = read_off(s->fd);
- s->offsets[i] = last_in_offset+read_off(s->fd);
- s->lengths[i] = read_off(s->fd);
+ offset += 4;
+
+ s->sectors[i] = last_out_offset+read_off(bs, offset);
+ offset += 8;
+
+ s->sectorcounts[i] = read_off(bs, offset);
+ offset += 8;
+
+ s->offsets[i] = last_in_offset+read_off(bs, offset);
+ offset += 8;
+
+ s->lengths[i] = read_off(bs, offset);
+ offset += 8;
+
if(s->lengths[i]>max_compressed_size)
max_compressed_size = s->lengths[i];
if(s->sectorcounts[i]>max_sectors_per_chunk)
@@ -163,11 +173,13 @@ dmg_close:
s->compressed_chunk = qemu_malloc(max_compressed_size+1);
s->uncompressed_chunk = qemu_malloc(512*max_sectors_per_chunk);
if(inflateInit(&s->zstream) != Z_OK)
- goto dmg_close;
+ goto fail;
s->current_chunk = s->n_chunks;
return 0;
+fail:
+ return -1;
}
static inline int is_sector_in_chunk(BDRVDMGState* s,
@@ -196,8 +208,10 @@ static inline uint32_t search_chunk(BDRVDMGState* s,int sector_num)
return s->n_chunks; /* error */
}
-static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
+static inline int dmg_read_chunk(BlockDriverState *bs, int sector_num)
{
+ BDRVDMGState *s = bs->opaque;
+
if(!is_sector_in_chunk(s,s->current_chunk,sector_num)) {
int ret;
uint32_t chunk = search_chunk(s,sector_num);
@@ -210,15 +224,12 @@ static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
case 0x80000005: { /* zlib compressed */
int i;
- ret = lseek(s->fd, s->offsets[chunk], SEEK_SET);
- if(ret<0)
- return -1;
-
/* we need to buffer, because only the chunk as whole can be
* inflated. */
i=0;
do {
- ret = read(s->fd, s->compressed_chunk+i, s->lengths[chunk]-i);
+ ret = bdrv_pread(bs->file, s->offsets[chunk] + i,
+ s->compressed_chunk+i, s->lengths[chunk]-i);
if(ret<0 && errno==EINTR)
ret=0;
i+=ret;
@@ -239,7 +250,8 @@ static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
return -1;
break; }
case 1: /* copy */
- ret = read(s->fd, s->uncompressed_chunk, s->lengths[chunk]);
+ ret = bdrv_pread(bs->file, s->offsets[chunk],
+ s->uncompressed_chunk, s->lengths[chunk]);
if (ret != s->lengths[chunk])
return -1;
break;
@@ -260,7 +272,7 @@ static int dmg_read(BlockDriverState *bs, int64_t sector_num,
for(i=0;i<nb_sectors;i++) {
uint32_t sector_offset_in_chunk;
- if(dmg_read_chunk(s, sector_num+i) != 0)
+ if(dmg_read_chunk(bs, sector_num+i) != 0)
return -1;
sector_offset_in_chunk = sector_num+i-s->sectors[s->current_chunk];
memcpy(buf+i*512,s->uncompressed_chunk+sector_offset_in_chunk*512,512);
@@ -271,7 +283,6 @@ static int dmg_read(BlockDriverState *bs, int64_t sector_num,
static void dmg_close(BlockDriverState *bs)
{
BDRVDMGState *s = bs->opaque;
- close(s->fd);
if(s->n_chunks>0) {
free(s->types);
free(s->offsets);
generated by cgit v1.1 at 2024-05-18 22:42:25 +0000