Merge branch 'upstream-merge'
[qemu-kvm/markmc.git] / block / dmg.c
blob262560ffd371d5f5f8d389deacb6d73ffa6afaf6
1 /*
2 * QEMU Block driver for DMG images
4 * Copyright (c) 2004 Johannes E. Schindelin
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
24 #include "qemu-common.h"
25 #include "block_int.h"
26 #include "bswap.h"
27 #include "module.h"
28 #include <zlib.h>
30 typedef struct BDRVDMGState {
31 int fd;
33 /* each chunk contains a certain number of sectors,
34 * offsets[i] is the offset in the .dmg file,
35 * lengths[i] is the length of the compressed chunk,
36 * sectors[i] is the sector beginning at offsets[i],
37 * sectorcounts[i] is the number of sectors in that chunk,
38 * the sectors array is ordered
39 * 0<=i<n_chunks */
41 uint32_t n_chunks;
42 uint32_t* types;
43 uint64_t* offsets;
44 uint64_t* lengths;
45 uint64_t* sectors;
46 uint64_t* sectorcounts;
47 uint32_t current_chunk;
48 uint8_t *compressed_chunk;
49 uint8_t *uncompressed_chunk;
50 z_stream zstream;
51 } BDRVDMGState;
53 static int dmg_probe(const uint8_t *buf, int buf_size, const char *filename)
55 int len=strlen(filename);
56 if(len>4 && !strcmp(filename+len-4,".dmg"))
57 return 2;
58 return 0;
61 static off_t read_off(int fd)
63 uint64_t buffer;
64 if(read(fd,&buffer,8)<8)
65 return 0;
66 return be64_to_cpu(buffer);
69 static off_t read_uint32(int fd)
71 uint32_t buffer;
72 if(read(fd,&buffer,4)<4)
73 return 0;
74 return be32_to_cpu(buffer);
77 static int dmg_open(BlockDriverState *bs, const char *filename, int flags)
79 BDRVDMGState *s = bs->opaque;
80 off_t info_begin,info_end,last_in_offset,last_out_offset;
81 uint32_t count;
82 uint32_t max_compressed_size=1,max_sectors_per_chunk=1,i;
84 s->fd = open(filename, O_RDONLY | O_BINARY);
85 if (s->fd < 0)
86 return -errno;
87 bs->read_only = 1;
88 s->n_chunks = 0;
89 s->offsets = s->lengths = s->sectors = s->sectorcounts = NULL;
91 /* read offset of info blocks */
92 if(lseek(s->fd,-0x1d8,SEEK_END)<0) {
93 dmg_close:
94 close(s->fd);
95 /* open raw instead */
96 bs->drv=bdrv_find_format("raw");
97 return bs->drv->bdrv_open(bs, filename, flags);
99 info_begin=read_off(s->fd);
100 if(info_begin==0)
101 goto dmg_close;
102 if(lseek(s->fd,info_begin,SEEK_SET)<0)
103 goto dmg_close;
104 if(read_uint32(s->fd)!=0x100)
105 goto dmg_close;
106 if((count = read_uint32(s->fd))==0)
107 goto dmg_close;
108 info_end = info_begin+count;
109 if(lseek(s->fd,0xf8,SEEK_CUR)<0)
110 goto dmg_close;
112 /* read offsets */
113 last_in_offset = last_out_offset = 0;
114 while(lseek(s->fd,0,SEEK_CUR)<info_end) {
115 uint32_t type;
117 count = read_uint32(s->fd);
118 if(count==0)
119 goto dmg_close;
120 type = read_uint32(s->fd);
121 if(type!=0x6d697368 || count<244)
122 lseek(s->fd,count-4,SEEK_CUR);
123 else {
124 int new_size, chunk_count;
125 if(lseek(s->fd,200,SEEK_CUR)<0)
126 goto dmg_close;
127 chunk_count = (count-204)/40;
128 new_size = sizeof(uint64_t) * (s->n_chunks + chunk_count);
129 s->types = qemu_realloc(s->types, new_size/2);
130 s->offsets = qemu_realloc(s->offsets, new_size);
131 s->lengths = qemu_realloc(s->lengths, new_size);
132 s->sectors = qemu_realloc(s->sectors, new_size);
133 s->sectorcounts = qemu_realloc(s->sectorcounts, new_size);
135 for(i=s->n_chunks;i<s->n_chunks+chunk_count;i++) {
136 s->types[i] = read_uint32(s->fd);
137 if(s->types[i]!=0x80000005 && s->types[i]!=1 && s->types[i]!=2) {
138 if(s->types[i]==0xffffffff) {
139 last_in_offset = s->offsets[i-1]+s->lengths[i-1];
140 last_out_offset = s->sectors[i-1]+s->sectorcounts[i-1];
142 chunk_count--;
143 i--;
144 if(lseek(s->fd,36,SEEK_CUR)<0)
145 goto dmg_close;
146 continue;
148 read_uint32(s->fd);
149 s->sectors[i] = last_out_offset+read_off(s->fd);
150 s->sectorcounts[i] = read_off(s->fd);
151 s->offsets[i] = last_in_offset+read_off(s->fd);
152 s->lengths[i] = read_off(s->fd);
153 if(s->lengths[i]>max_compressed_size)
154 max_compressed_size = s->lengths[i];
155 if(s->sectorcounts[i]>max_sectors_per_chunk)
156 max_sectors_per_chunk = s->sectorcounts[i];
158 s->n_chunks+=chunk_count;
162 /* initialize zlib engine */
163 s->compressed_chunk = qemu_malloc(max_compressed_size+1);
164 s->uncompressed_chunk = qemu_malloc(512*max_sectors_per_chunk);
165 if(inflateInit(&s->zstream) != Z_OK)
166 goto dmg_close;
168 s->current_chunk = s->n_chunks;
170 return 0;
173 static inline int is_sector_in_chunk(BDRVDMGState* s,
174 uint32_t chunk_num,int sector_num)
176 if(chunk_num>=s->n_chunks || s->sectors[chunk_num]>sector_num ||
177 s->sectors[chunk_num]+s->sectorcounts[chunk_num]<=sector_num)
178 return 0;
179 else
180 return -1;
183 static inline uint32_t search_chunk(BDRVDMGState* s,int sector_num)
185 /* binary search */
186 uint32_t chunk1=0,chunk2=s->n_chunks,chunk3;
187 while(chunk1!=chunk2) {
188 chunk3 = (chunk1+chunk2)/2;
189 if(s->sectors[chunk3]>sector_num)
190 chunk2 = chunk3;
191 else if(s->sectors[chunk3]+s->sectorcounts[chunk3]>sector_num)
192 return chunk3;
193 else
194 chunk1 = chunk3;
196 return s->n_chunks; /* error */
199 static inline int dmg_read_chunk(BDRVDMGState *s,int sector_num)
201 if(!is_sector_in_chunk(s,s->current_chunk,sector_num)) {
202 int ret;
203 uint32_t chunk = search_chunk(s,sector_num);
205 if(chunk>=s->n_chunks)
206 return -1;
208 s->current_chunk = s->n_chunks;
209 switch(s->types[chunk]) {
210 case 0x80000005: { /* zlib compressed */
211 int i;
213 ret = lseek(s->fd, s->offsets[chunk], SEEK_SET);
214 if(ret<0)
215 return -1;
217 /* we need to buffer, because only the chunk as whole can be
218 * inflated. */
219 i=0;
220 do {
221 ret = read(s->fd, s->compressed_chunk+i, s->lengths[chunk]-i);
222 if(ret<0 && errno==EINTR)
223 ret=0;
224 i+=ret;
225 } while(ret>=0 && ret+i<s->lengths[chunk]);
227 if (ret != s->lengths[chunk])
228 return -1;
230 s->zstream.next_in = s->compressed_chunk;
231 s->zstream.avail_in = s->lengths[chunk];
232 s->zstream.next_out = s->uncompressed_chunk;
233 s->zstream.avail_out = 512*s->sectorcounts[chunk];
234 ret = inflateReset(&s->zstream);
235 if(ret != Z_OK)
236 return -1;
237 ret = inflate(&s->zstream, Z_FINISH);
238 if(ret != Z_STREAM_END || s->zstream.total_out != 512*s->sectorcounts[chunk])
239 return -1;
240 break; }
241 case 1: /* copy */
242 ret = read(s->fd, s->uncompressed_chunk, s->lengths[chunk]);
243 if (ret != s->lengths[chunk])
244 return -1;
245 break;
246 case 2: /* zero */
247 memset(s->uncompressed_chunk, 0, 512*s->sectorcounts[chunk]);
248 break;
250 s->current_chunk = chunk;
252 return 0;
255 static int dmg_read(BlockDriverState *bs, int64_t sector_num,
256 uint8_t *buf, int nb_sectors)
258 BDRVDMGState *s = bs->opaque;
259 int i;
261 for(i=0;i<nb_sectors;i++) {
262 uint32_t sector_offset_in_chunk;
263 if(dmg_read_chunk(s, sector_num+i) != 0)
264 return -1;
265 sector_offset_in_chunk = sector_num+i-s->sectors[s->current_chunk];
266 memcpy(buf+i*512,s->uncompressed_chunk+sector_offset_in_chunk*512,512);
268 return 0;
271 static void dmg_close(BlockDriverState *bs)
273 BDRVDMGState *s = bs->opaque;
274 close(s->fd);
275 if(s->n_chunks>0) {
276 free(s->types);
277 free(s->offsets);
278 free(s->lengths);
279 free(s->sectors);
280 free(s->sectorcounts);
282 free(s->compressed_chunk);
283 free(s->uncompressed_chunk);
284 inflateEnd(&s->zstream);
287 static BlockDriver bdrv_dmg = {
288 .format_name = "dmg",
289 .instance_size = sizeof(BDRVDMGState),
290 .bdrv_probe = dmg_probe,
291 .bdrv_open = dmg_open,
292 .bdrv_read = dmg_read,
293 .bdrv_close = dmg_close,
296 static void bdrv_dmg_init(void)
298 bdrv_register(&bdrv_dmg);
301 block_init(bdrv_dmg_init);