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1.1 root 1: /*
2: * QEMU Block driver for CLOOP images
3: *
4: * Copyright (c) 2004 Johannes E. Schindelin
5: *
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: */
24: #include "qemu-common.h"
25: #include "block_int.h"
26: #include "module.h"
27: #include <zlib.h>
28:
29: typedef struct BDRVCloopState {
1.1.1.3 ! root 30: CoMutex lock;
1.1 root 31: uint32_t block_size;
32: uint32_t n_blocks;
1.1.1.3 ! root 33: uint64_t *offsets;
1.1 root 34: uint32_t sectors_per_block;
35: uint32_t current_block;
36: uint8_t *compressed_block;
37: uint8_t *uncompressed_block;
38: z_stream zstream;
39: } BDRVCloopState;
40:
41: static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename)
42: {
1.1.1.3 ! root 43: const char *magic_version_2_0 = "#!/bin/sh\n"
! 44: "#V2.0 Format\n"
! 45: "modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n";
! 46: int length = strlen(magic_version_2_0);
! 47: if (length > buf_size) {
! 48: length = buf_size;
! 49: }
! 50: if (!memcmp(magic_version_2_0, buf, length)) {
! 51: return 2;
! 52: }
1.1 root 53: return 0;
54: }
55:
1.1.1.2 root 56: static int cloop_open(BlockDriverState *bs, int flags)
1.1 root 57: {
58: BDRVCloopState *s = bs->opaque;
1.1.1.3 ! root 59: uint32_t offsets_size, max_compressed_block_size = 1, i;
1.1 root 60:
61: bs->read_only = 1;
62:
63: /* read header */
1.1.1.2 root 64: if (bdrv_pread(bs->file, 128, &s->block_size, 4) < 4) {
65: goto cloop_close;
1.1 root 66: }
1.1.1.2 root 67: s->block_size = be32_to_cpu(s->block_size);
68:
69: if (bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4) < 4) {
70: goto cloop_close;
71: }
72: s->n_blocks = be32_to_cpu(s->n_blocks);
1.1 root 73:
74: /* read offsets */
1.1.1.2 root 75: offsets_size = s->n_blocks * sizeof(uint64_t);
1.1.1.3 ! root 76: s->offsets = g_malloc(offsets_size);
1.1.1.2 root 77: if (bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size) <
78: offsets_size) {
1.1.1.3 ! root 79: goto cloop_close;
1.1.1.2 root 80: }
1.1 root 81: for(i=0;i<s->n_blocks;i++) {
1.1.1.3 ! root 82: s->offsets[i] = be64_to_cpu(s->offsets[i]);
! 83: if (i > 0) {
! 84: uint32_t size = s->offsets[i] - s->offsets[i - 1];
! 85: if (size > max_compressed_block_size) {
! 86: max_compressed_block_size = size;
! 87: }
! 88: }
1.1 root 89: }
90:
91: /* initialize zlib engine */
1.1.1.3 ! root 92: s->compressed_block = g_malloc(max_compressed_block_size + 1);
! 93: s->uncompressed_block = g_malloc(s->block_size);
! 94: if (inflateInit(&s->zstream) != Z_OK) {
! 95: goto cloop_close;
! 96: }
! 97: s->current_block = s->n_blocks;
1.1 root 98:
99: s->sectors_per_block = s->block_size/512;
1.1.1.3 ! root 100: bs->total_sectors = s->n_blocks * s->sectors_per_block;
! 101: qemu_co_mutex_init(&s->lock);
1.1 root 102: return 0;
1.1.1.2 root 103:
104: cloop_close:
105: return -1;
1.1 root 106: }
107:
1.1.1.2 root 108: static inline int cloop_read_block(BlockDriverState *bs, int block_num)
1.1 root 109: {
1.1.1.2 root 110: BDRVCloopState *s = bs->opaque;
111:
1.1.1.3 ! root 112: if (s->current_block != block_num) {
! 113: int ret;
! 114: uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num];
1.1 root 115:
1.1.1.2 root 116: ret = bdrv_pread(bs->file, s->offsets[block_num], s->compressed_block,
117: bytes);
1.1.1.3 ! root 118: if (ret != bytes) {
1.1 root 119: return -1;
1.1.1.3 ! root 120: }
1.1 root 121:
1.1.1.3 ! root 122: s->zstream.next_in = s->compressed_block;
! 123: s->zstream.avail_in = bytes;
! 124: s->zstream.next_out = s->uncompressed_block;
! 125: s->zstream.avail_out = s->block_size;
! 126: ret = inflateReset(&s->zstream);
! 127: if (ret != Z_OK) {
! 128: return -1;
! 129: }
! 130: ret = inflate(&s->zstream, Z_FINISH);
! 131: if (ret != Z_STREAM_END || s->zstream.total_out != s->block_size) {
! 132: return -1;
! 133: }
1.1 root 134:
1.1.1.3 ! root 135: s->current_block = block_num;
1.1 root 136: }
137: return 0;
138: }
139:
140: static int cloop_read(BlockDriverState *bs, int64_t sector_num,
141: uint8_t *buf, int nb_sectors)
142: {
143: BDRVCloopState *s = bs->opaque;
144: int i;
145:
1.1.1.3 ! root 146: for (i = 0; i < nb_sectors; i++) {
! 147: uint32_t sector_offset_in_block =
! 148: ((sector_num + i) % s->sectors_per_block),
! 149: block_num = (sector_num + i) / s->sectors_per_block;
! 150: if (cloop_read_block(bs, block_num) != 0) {
! 151: return -1;
! 152: }
! 153: memcpy(buf + i * 512,
! 154: s->uncompressed_block + sector_offset_in_block * 512, 512);
1.1 root 155: }
156: return 0;
157: }
158:
1.1.1.3 ! root 159: static coroutine_fn int cloop_co_read(BlockDriverState *bs, int64_t sector_num,
! 160: uint8_t *buf, int nb_sectors)
! 161: {
! 162: int ret;
! 163: BDRVCloopState *s = bs->opaque;
! 164: qemu_co_mutex_lock(&s->lock);
! 165: ret = cloop_read(bs, sector_num, buf, nb_sectors);
! 166: qemu_co_mutex_unlock(&s->lock);
! 167: return ret;
! 168: }
! 169:
1.1 root 170: static void cloop_close(BlockDriverState *bs)
171: {
172: BDRVCloopState *s = bs->opaque;
1.1.1.3 ! root 173: if (s->n_blocks > 0) {
! 174: g_free(s->offsets);
! 175: }
! 176: g_free(s->compressed_block);
! 177: g_free(s->uncompressed_block);
1.1 root 178: inflateEnd(&s->zstream);
179: }
180:
181: static BlockDriver bdrv_cloop = {
1.1.1.3 ! root 182: .format_name = "cloop",
! 183: .instance_size = sizeof(BDRVCloopState),
! 184: .bdrv_probe = cloop_probe,
! 185: .bdrv_open = cloop_open,
! 186: .bdrv_read = cloop_co_read,
! 187: .bdrv_close = cloop_close,
1.1 root 188: };
189:
190: static void bdrv_cloop_init(void)
191: {
192: bdrv_register(&bdrv_cloop);
193: }
194:
195: block_init(bdrv_cloop_init);
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