/* * 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 "qemu-common.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; uint8_t *compressed_block; uint8_t *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, int flags) { BDRVCloopState *s = bs->opaque; uint32_t offsets_size,max_compressed_block_size=1,i; s->fd = open(filename, O_RDONLY | O_BINARY); if (s->fd < 0) return -errno; 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); s->offsets=(uint64_t*)qemu_malloc(offsets_size); 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 */ s->compressed_block = qemu_malloc(max_compressed_block_size+1); s->uncompressed_block = qemu_malloc(s->block_size); 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 = { .format_name = "cloop", .instance_size = sizeof(BDRVCloopState), .bdrv_probe = cloop_probe, .bdrv_open = cloop_open, .bdrv_read = cloop_read, .bdrv_close = cloop_close, };