--- /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 "module.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_find_format("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);
+}
+
+static 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,
+};
+
+static void bdrv_dmg_init(void)
+{
+ bdrv_register(&bdrv_dmg);
+}
+
+block_init(bdrv_dmg_init);
projects / qemu / blobdiff