+++ /dev/null
-/*
- * 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,
-};
projects / qemu / blobdiff