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