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Commit | Line | Data |
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3c56521b | 1 | /* |
585d0ed9 | 2 | * QEMU Block driver for CLOOP images |
5fafdf24 | 3 | * |
3c56521b | 4 | * Copyright (c) 2004 Johannes E. Schindelin |
5fafdf24 | 5 | * |
3c56521b FB |
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: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
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. | |
23 | */ | |
80c71a24 | 24 | #include "qemu/osdep.h" |
da34e65c | 25 | #include "qapi/error.h" |
faf07963 | 26 | #include "qemu-common.h" |
737e150e | 27 | #include "block/block_int.h" |
1de7afc9 | 28 | #include "qemu/module.h" |
3c56521b FB |
29 | #include <zlib.h> |
30 | ||
d65f97a8 SH |
31 | /* Maximum compressed block size */ |
32 | #define MAX_BLOCK_SIZE (64 * 1024 * 1024) | |
33 | ||
3c56521b | 34 | typedef struct BDRVCloopState { |
848c66e8 | 35 | CoMutex lock; |
3c56521b FB |
36 | uint32_t block_size; |
37 | uint32_t n_blocks; | |
5b47b7c3 | 38 | uint64_t *offsets; |
3c56521b FB |
39 | uint32_t sectors_per_block; |
40 | uint32_t current_block; | |
28a5c9c8 FB |
41 | uint8_t *compressed_block; |
42 | uint8_t *uncompressed_block; | |
3c56521b FB |
43 | z_stream zstream; |
44 | } BDRVCloopState; | |
45 | ||
46 | static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename) | |
47 | { | |
5b47b7c3 DXW |
48 | const char *magic_version_2_0 = "#!/bin/sh\n" |
49 | "#V2.0 Format\n" | |
50 | "modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n"; | |
51 | int length = strlen(magic_version_2_0); | |
52 | if (length > buf_size) { | |
53 | length = buf_size; | |
54 | } | |
55 | if (!memcmp(magic_version_2_0, buf, length)) { | |
56 | return 2; | |
57 | } | |
3c56521b FB |
58 | return 0; |
59 | } | |
60 | ||
015a1036 HR |
61 | static int cloop_open(BlockDriverState *bs, QDict *options, int flags, |
62 | Error **errp) | |
3c56521b FB |
63 | { |
64 | BDRVCloopState *s = bs->opaque; | |
5b47b7c3 | 65 | uint32_t offsets_size, max_compressed_block_size = 1, i; |
1a60657f | 66 | int ret; |
3c56521b | 67 | |
3c56521b FB |
68 | bs->read_only = 1; |
69 | ||
70 | /* read header */ | |
9a4f4c31 | 71 | ret = bdrv_pread(bs->file->bs, 128, &s->block_size, 4); |
1a60657f KW |
72 | if (ret < 0) { |
73 | return ret; | |
3c56521b | 74 | } |
c94304be | 75 | s->block_size = be32_to_cpu(s->block_size); |
d65f97a8 | 76 | if (s->block_size % 512) { |
370e6816 | 77 | error_setg(errp, "block_size %" PRIu32 " must be a multiple of 512", |
d65f97a8 SH |
78 | s->block_size); |
79 | return -EINVAL; | |
80 | } | |
81 | if (s->block_size == 0) { | |
82 | error_setg(errp, "block_size cannot be zero"); | |
83 | return -EINVAL; | |
84 | } | |
85 | ||
86 | /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but | |
87 | * we can accept more. Prevent ridiculous values like 4 GB - 1 since we | |
88 | * need a buffer this big. | |
89 | */ | |
90 | if (s->block_size > MAX_BLOCK_SIZE) { | |
370e6816 | 91 | error_setg(errp, "block_size %" PRIu32 " must be %u MB or less", |
d65f97a8 SH |
92 | s->block_size, |
93 | MAX_BLOCK_SIZE / (1024 * 1024)); | |
94 | return -EINVAL; | |
95 | } | |
c94304be | 96 | |
9a4f4c31 | 97 | ret = bdrv_pread(bs->file->bs, 128 + 4, &s->n_blocks, 4); |
1a60657f KW |
98 | if (ret < 0) { |
99 | return ret; | |
c94304be CH |
100 | } |
101 | s->n_blocks = be32_to_cpu(s->n_blocks); | |
3c56521b FB |
102 | |
103 | /* read offsets */ | |
42d43d35 | 104 | if (s->n_blocks > (UINT32_MAX - 1) / sizeof(uint64_t)) { |
509a41ba | 105 | /* Prevent integer overflow */ |
370e6816 | 106 | error_setg(errp, "n_blocks %" PRIu32 " must be %zu or less", |
509a41ba | 107 | s->n_blocks, |
42d43d35 | 108 | (UINT32_MAX - 1) / sizeof(uint64_t)); |
509a41ba SH |
109 | return -EINVAL; |
110 | } | |
42d43d35 | 111 | offsets_size = (s->n_blocks + 1) * sizeof(uint64_t); |
7b103b36 SH |
112 | if (offsets_size > 512 * 1024 * 1024) { |
113 | /* Prevent ridiculous offsets_size which causes memory allocation to | |
114 | * fail or overflows bdrv_pread() size. In practice the 512 MB | |
115 | * offsets[] limit supports 16 TB images at 256 KB block size. | |
116 | */ | |
117 | error_setg(errp, "image requires too many offsets, " | |
118 | "try increasing block size"); | |
119 | return -EINVAL; | |
120 | } | |
4ae7a52e KW |
121 | |
122 | s->offsets = g_try_malloc(offsets_size); | |
123 | if (s->offsets == NULL) { | |
124 | error_setg(errp, "Could not allocate offsets table"); | |
125 | return -ENOMEM; | |
126 | } | |
1a60657f | 127 | |
9a4f4c31 | 128 | ret = bdrv_pread(bs->file->bs, 128 + 4 + 4, s->offsets, offsets_size); |
1a60657f KW |
129 | if (ret < 0) { |
130 | goto fail; | |
c94304be | 131 | } |
1a60657f | 132 | |
42d43d35 | 133 | for (i = 0; i < s->n_blocks + 1; i++) { |
f56b9bc3 SH |
134 | uint64_t size; |
135 | ||
5b47b7c3 | 136 | s->offsets[i] = be64_to_cpu(s->offsets[i]); |
f56b9bc3 SH |
137 | if (i == 0) { |
138 | continue; | |
139 | } | |
140 | ||
141 | if (s->offsets[i] < s->offsets[i - 1]) { | |
142 | error_setg(errp, "offsets not monotonically increasing at " | |
370e6816 | 143 | "index %" PRIu32 ", image file is corrupt", i); |
f56b9bc3 SH |
144 | ret = -EINVAL; |
145 | goto fail; | |
146 | } | |
147 | ||
148 | size = s->offsets[i] - s->offsets[i - 1]; | |
149 | ||
150 | /* Compressed blocks should be smaller than the uncompressed block size | |
151 | * but maybe compression performed poorly so the compressed block is | |
152 | * actually bigger. Clamp down on unrealistic values to prevent | |
153 | * ridiculous s->compressed_block allocation. | |
154 | */ | |
155 | if (size > 2 * MAX_BLOCK_SIZE) { | |
370e6816 SH |
156 | error_setg(errp, "invalid compressed block size at index %" PRIu32 |
157 | ", image file is corrupt", i); | |
f56b9bc3 SH |
158 | ret = -EINVAL; |
159 | goto fail; | |
160 | } | |
161 | ||
162 | if (size > max_compressed_block_size) { | |
163 | max_compressed_block_size = size; | |
5b47b7c3 | 164 | } |
3c56521b FB |
165 | } |
166 | ||
167 | /* initialize zlib engine */ | |
4ae7a52e KW |
168 | s->compressed_block = g_try_malloc(max_compressed_block_size + 1); |
169 | if (s->compressed_block == NULL) { | |
170 | error_setg(errp, "Could not allocate compressed_block"); | |
171 | ret = -ENOMEM; | |
172 | goto fail; | |
173 | } | |
174 | ||
175 | s->uncompressed_block = g_try_malloc(s->block_size); | |
176 | if (s->uncompressed_block == NULL) { | |
177 | error_setg(errp, "Could not allocate uncompressed_block"); | |
178 | ret = -ENOMEM; | |
179 | goto fail; | |
180 | } | |
181 | ||
5b47b7c3 | 182 | if (inflateInit(&s->zstream) != Z_OK) { |
1a60657f KW |
183 | ret = -EINVAL; |
184 | goto fail; | |
5b47b7c3 DXW |
185 | } |
186 | s->current_block = s->n_blocks; | |
3b46e624 | 187 | |
3c56521b | 188 | s->sectors_per_block = s->block_size/512; |
5b47b7c3 | 189 | bs->total_sectors = s->n_blocks * s->sectors_per_block; |
848c66e8 | 190 | qemu_co_mutex_init(&s->lock); |
3c56521b | 191 | return 0; |
c94304be | 192 | |
1a60657f KW |
193 | fail: |
194 | g_free(s->offsets); | |
195 | g_free(s->compressed_block); | |
196 | g_free(s->uncompressed_block); | |
197 | return ret; | |
3c56521b FB |
198 | } |
199 | ||
20be49e4 | 200 | static inline int cloop_read_block(BlockDriverState *bs, int block_num) |
3c56521b | 201 | { |
20be49e4 CH |
202 | BDRVCloopState *s = bs->opaque; |
203 | ||
5b47b7c3 DXW |
204 | if (s->current_block != block_num) { |
205 | int ret; | |
206 | uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num]; | |
3b46e624 | 207 | |
9a4f4c31 KW |
208 | ret = bdrv_pread(bs->file->bs, s->offsets[block_num], |
209 | s->compressed_block, bytes); | |
5b47b7c3 | 210 | if (ret != bytes) { |
3c56521b | 211 | return -1; |
5b47b7c3 DXW |
212 | } |
213 | ||
214 | s->zstream.next_in = s->compressed_block; | |
215 | s->zstream.avail_in = bytes; | |
216 | s->zstream.next_out = s->uncompressed_block; | |
217 | s->zstream.avail_out = s->block_size; | |
218 | ret = inflateReset(&s->zstream); | |
219 | if (ret != Z_OK) { | |
220 | return -1; | |
221 | } | |
222 | ret = inflate(&s->zstream, Z_FINISH); | |
223 | if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) { | |
224 | return -1; | |
225 | } | |
5fafdf24 | 226 | |
5b47b7c3 | 227 | s->current_block = block_num; |
3c56521b FB |
228 | } |
229 | return 0; | |
230 | } | |
231 | ||
5fafdf24 | 232 | static int cloop_read(BlockDriverState *bs, int64_t sector_num, |
3c56521b FB |
233 | uint8_t *buf, int nb_sectors) |
234 | { | |
235 | BDRVCloopState *s = bs->opaque; | |
236 | int i; | |
237 | ||
5b47b7c3 DXW |
238 | for (i = 0; i < nb_sectors; i++) { |
239 | uint32_t sector_offset_in_block = | |
240 | ((sector_num + i) % s->sectors_per_block), | |
241 | block_num = (sector_num + i) / s->sectors_per_block; | |
242 | if (cloop_read_block(bs, block_num) != 0) { | |
243 | return -1; | |
244 | } | |
245 | memcpy(buf + i * 512, | |
246 | s->uncompressed_block + sector_offset_in_block * 512, 512); | |
3c56521b FB |
247 | } |
248 | return 0; | |
249 | } | |
250 | ||
2914caa0 PB |
251 | static coroutine_fn int cloop_co_read(BlockDriverState *bs, int64_t sector_num, |
252 | uint8_t *buf, int nb_sectors) | |
253 | { | |
254 | int ret; | |
255 | BDRVCloopState *s = bs->opaque; | |
256 | qemu_co_mutex_lock(&s->lock); | |
257 | ret = cloop_read(bs, sector_num, buf, nb_sectors); | |
258 | qemu_co_mutex_unlock(&s->lock); | |
259 | return ret; | |
260 | } | |
261 | ||
3c56521b FB |
262 | static void cloop_close(BlockDriverState *bs) |
263 | { | |
264 | BDRVCloopState *s = bs->opaque; | |
42d43d35 | 265 | g_free(s->offsets); |
756f51e4 DXW |
266 | g_free(s->compressed_block); |
267 | g_free(s->uncompressed_block); | |
3c56521b FB |
268 | inflateEnd(&s->zstream); |
269 | } | |
270 | ||
5efa9d5a | 271 | static BlockDriver bdrv_cloop = { |
5b47b7c3 DXW |
272 | .format_name = "cloop", |
273 | .instance_size = sizeof(BDRVCloopState), | |
274 | .bdrv_probe = cloop_probe, | |
275 | .bdrv_open = cloop_open, | |
276 | .bdrv_read = cloop_co_read, | |
277 | .bdrv_close = cloop_close, | |
3c56521b | 278 | }; |
5efa9d5a AL |
279 | |
280 | static void bdrv_cloop_init(void) | |
281 | { | |
282 | bdrv_register(&bdrv_cloop); | |
283 | } | |
284 | ||
285 | block_init(bdrv_cloop_init); |