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/*
* QEMU Block driver for CLOOP 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 "vl.h"
#include "block_int.h"
#include <zlib.h>
typedef struct BDRVCloopState {
int fd;
uint32_t block_size;
uint32_t n_blocks;
uint64_t* offsets;
uint32_t sectors_per_block;
uint32_t current_block;
char* compressed_block;
char* uncompressed_block;
z_stream zstream;
} BDRVCloopState;
static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
{
const char* magic_version_2_0="#!/bin/sh\n"
"#V2.0 Format\n"
"modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n";
int length=strlen(magic_version_2_0);
if(length>buf_size)
length=buf_size;
if(!memcmp(magic_version_2_0,buf,length))
return 2;
return 0;
}
static int cloop_open(BlockDriverState *bs, const char *filename)
{
BDRVCloopState *s = bs->opaque;
uint32_t offsets_size,max_compressed_block_size=1,i;
s->fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
if (s->fd < 0)
return -1;
bs->read_only = 1;
/* read header */
if(lseek(s->fd,128,SEEK_SET)<0) {
cloop_close:
close(s->fd);
return -1;
}
if(read(s->fd,&s->block_size,4)<4)
goto cloop_close;
s->block_size=be32_to_cpu(s->block_size);
if(read(s->fd,&s->n_blocks,4)<4)
goto cloop_close;
s->n_blocks=be32_to_cpu(s->n_blocks);
/* read offsets */
offsets_size=s->n_blocks*sizeof(uint64_t);
if(!(s->offsets=(uint64_t*)malloc(offsets_size)))
goto cloop_close;
if(read(s->fd,s->offsets,offsets_size)<offsets_size)
goto cloop_close;
for(i=0;i<s->n_blocks;i++) {
s->offsets[i]=be64_to_cpu(s->offsets[i]);
if(i>0) {
uint32_t size=s->offsets[i]-s->offsets[i-1];
if(size>max_compressed_block_size)
max_compressed_block_size=size;
}
}
/* initialize zlib engine */
if(!(s->compressed_block=(char*)malloc(max_compressed_block_size+1)))
goto cloop_close;
if(!(s->uncompressed_block=(char*)malloc(s->block_size)))
goto cloop_close;
if(inflateInit(&s->zstream) != Z_OK)
goto cloop_close;
s->current_block=s->n_blocks;
s->sectors_per_block = s->block_size/512;
bs->total_sectors = s->n_blocks*s->sectors_per_block;
return 0;
}
static inline int cloop_read_block(BDRVCloopState *s,int block_num)
{
if(s->current_block != block_num) {
int ret;
uint32_t bytes = s->offsets[block_num+1]-s->offsets[block_num];
lseek(s->fd, s->offsets[block_num], SEEK_SET);
ret = read(s->fd, s->compressed_block, bytes);
if (ret != bytes)
return -1;
s->zstream.next_in = s->compressed_block;
s->zstream.avail_in = bytes;
s->zstream.next_out = s->uncompressed_block;
s->zstream.avail_out = s->block_size;
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 != s->block_size)
return -1;
s->current_block = block_num;
}
return 0;
}
static int cloop_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
BDRVCloopState *s = bs->opaque;
int i;
for(i=0;i<nb_sectors;i++) {
uint32_t sector_offset_in_block=((sector_num+i)%s->sectors_per_block),
block_num=(sector_num+i)/s->sectors_per_block;
if(cloop_read_block(s, block_num) != 0)
return -1;
memcpy(buf+i*512,s->uncompressed_block+sector_offset_in_block*512,512);
}
return 0;
}
static void cloop_close(BlockDriverState *bs)
{
BDRVCloopState *s = bs->opaque;
close(s->fd);
if(s->n_blocks>0)
free(s->offsets);
free(s->compressed_block);
free(s->uncompressed_block);
inflateEnd(&s->zstream);
}
BlockDriver bdrv_cloop = {
"cloop",
sizeof(BDRVCloopState),
cloop_probe,
cloop_open,
cloop_read,
NULL,
cloop_close,
};
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