qemu/block-dmg.c
aurel32 e60f469ca8 Use C99 initializers for BlockDriver methods
Consistently use the C99 named initializer format for the BlockDriver
methods to make the method table more readable and more easily
extensible.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6768 c046a42c-6fe2-441c-8c8c-71466251a162
2009-03-07 22:00:29 +00:00

294 lines
8.2 KiB
C

/*
* QEMU Block driver for DMG images
*
* Copyright (c) 2004 Johannes E. Schindelin
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu-common.h"
#include "block_int.h"
#include "bswap.h"
#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,
* sectors[i] is the sector beginning at offsets[i],
* sectorcounts[i] is the number of sectors in that chunk,
* the sectors array is ordered
* 0<=i<n_chunks */
uint32_t n_chunks;
uint32_t* types;
uint64_t* offsets;
uint64_t* lengths;
uint64_t* sectors;
uint64_t* sectorcounts;
uint32_t current_chunk;
uint8_t *compressed_chunk;
uint8_t *uncompressed_chunk;
z_stream zstream;
} BDRVDMGState;
static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename)
{
int len=strlen(filename);
if(len>4 && !strcmp(filename+len-4,".dmg"))
return 2;
return 0;
}
static off_t read_off(int fd)
{
uint64_t buffer;
if(read(fd,&buffer,8)<8)
return 0;
return be64_to_cpu(buffer);
}
static off_t read_uint32(int fd)
{
uint32_t buffer;
if(read(fd,&buffer,4)<4)
return 0;
return be32_to_cpu(buffer);
}
static int dmg_open(BlockDriverState *bs, const char *filename, 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;
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_raw;
return bs->drv->bdrv_open(bs, filename, flags);
}
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;
/* read offsets */
last_in_offset = last_out_offset = 0;
while(lseek(s->fd,0,SEEK_CUR)<info_end) {
uint32_t type;
count = read_uint32(s->fd);
if(count==0)
goto dmg_close;
type = read_uint32(s->fd);
if(type!=0x6d697368 || count<244)
lseek(s->fd,count-4,SEEK_CUR);
else {
int new_size, chunk_count;
if(lseek(s->fd,200,SEEK_CUR)<0)
goto dmg_close;
chunk_count = (count-204)/40;
new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
s->types = qemu_realloc(s->types, new_size/2);
s->offsets = qemu_realloc(s->offsets, new_size);
s->lengths = qemu_realloc(s->lengths, new_size);
s->sectors = qemu_realloc(s->sectors, new_size);
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);
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];
last_out_offset = s->sectors[i-1]+s->sectorcounts[i-1];
}
chunk_count--;
i--;
if(lseek(s->fd,36,SEEK_CUR)<0)
goto dmg_close;
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);
if(s->lengths[i]>max_compressed_size)
max_compressed_size = s->lengths[i];
if(s->sectorcounts[i]>max_sectors_per_chunk)
max_sectors_per_chunk = s->sectorcounts[i];
}
s->n_chunks+=chunk_count;
}
}
/* initialize zlib engine */
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;
s->current_chunk = s->n_chunks;
return 0;
}
static inline int is_sector_in_chunk(BDRVDMGState* s,
uint32_t chunk_num,int sector_num)
{
if(chunk_num>=s->n_chunks || s->sectors[chunk_num]>sector_num ||
s->sectors[chunk_num]+s->sectorcounts[chunk_num]<=sector_num)
return 0;
else
return -1;
}
static inline uint32_t search_chunk(BDRVDMGState* s,int sector_num)
{
/* binary search */
uint32_t chunk1=0,chunk2=s->n_chunks,chunk3;
while(chunk1!=chunk2) {
chunk3 = (chunk1+chunk2)/2;
if(s->sectors[chunk3]>sector_num)
chunk2 = chunk3;
else if(s->sectors[chunk3]+s->sectorcounts[chunk3]>sector_num)
return chunk3;
else
chunk1 = chunk3;
}
return s->n_chunks; /* error */
}
static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
{
if(!is_sector_in_chunk(s,s->current_chunk,sector_num)) {
int ret;
uint32_t chunk = search_chunk(s,sector_num);
if(chunk>=s->n_chunks)
return -1;
s->current_chunk = s->n_chunks;
switch(s->types[chunk]) {
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);
if(ret<0 && errno==EINTR)
ret=0;
i+=ret;
} while(ret>=0 && ret+i<s->lengths[chunk]);
if (ret != s->lengths[chunk])
return -1;
s->zstream.next_in = s->compressed_chunk;
s->zstream.avail_in = s->lengths[chunk];
s->zstream.next_out = s->uncompressed_chunk;
s->zstream.avail_out = 512*s->sectorcounts[chunk];
ret = inflateReset(&s->zstream);
if(ret != Z_OK)
return -1;
ret = inflate(&s->zstream, Z_FINISH);
if(ret != Z_STREAM_END || s->zstream.total_out != 512*s->sectorcounts[chunk])
return -1;
break; }
case 1: /* copy */
ret = read(s->fd, s->uncompressed_chunk, s->lengths[chunk]);
if (ret != s->lengths[chunk])
return -1;
break;
case 2: /* zero */
memset(s->uncompressed_chunk, 0, 512*s->sectorcounts[chunk]);
break;
}
s->current_chunk = chunk;
}
return 0;
}
static int dmg_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BDRVDMGState *s = bs->opaque;
int i;
for(i=0;i<nb_sectors;i++) {
uint32_t sector_offset_in_chunk;
if(dmg_read_chunk(s, 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);
}
return 0;
}
static void dmg_close(BlockDriverState *bs)
{
BDRVDMGState *s = bs->opaque;
close(s->fd);
if(s->n_chunks>0) {
free(s->types);
free(s->offsets);
free(s->lengths);
free(s->sectors);
free(s->sectorcounts);
}
free(s->compressed_chunk);
free(s->uncompressed_chunk);
inflateEnd(&s->zstream);
}
BlockDriver bdrv_dmg = {
.format_name = "dmg",
.instance_size = sizeof(BDRVDMGState),
.bdrv_probe = dmg_probe,
.bdrv_open = dmg_open,
.bdrv_read = dmg_read,
.bdrv_close = dmg_close,
};