| /* |
| * QEMU Block driver for CLOOP 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/osdep.h" |
| #include "qapi/error.h" |
| #include "qemu/error-report.h" |
| #include "block/block_int.h" |
| #include "qemu/module.h" |
| #include "qemu/bswap.h" |
| #include <zlib.h> |
| |
| /* Maximum compressed block size */ |
| #define MAX_BLOCK_SIZE (64 * 1024 * 1024) |
| |
| typedef struct BDRVCloopState { |
| CoMutex lock; |
| uint32_t block_size; |
| uint32_t n_blocks; |
| uint64_t *offsets; |
| uint32_t sectors_per_block; |
| uint32_t current_block; |
| uint8_t *compressed_block; |
| uint8_t *uncompressed_block; |
| z_stream zstream; |
| } BDRVCloopState; |
| |
| static int cloop_probe(const uint8_t *buf, int buf_size, const char *filename) |
| { |
| const char *magic_version_2_0 = "#!/bin/sh\n" |
| "#V2.0 Format\n" |
| "modprobe cloop file=$0 && mount -r -t iso9660 /dev/cloop $1\n"; |
| int length = strlen(magic_version_2_0); |
| if (length > buf_size) { |
| length = buf_size; |
| } |
| if (!memcmp(magic_version_2_0, buf, length)) { |
| return 2; |
| } |
| return 0; |
| } |
| |
| static int cloop_open(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp) |
| { |
| BDRVCloopState *s = bs->opaque; |
| uint32_t offsets_size, max_compressed_block_size = 1, i; |
| int ret; |
| |
| ret = bdrv_apply_auto_read_only(bs, NULL, errp); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 0, |
| false, errp); |
| if (!bs->file) { |
| return -EINVAL; |
| } |
| |
| /* read header */ |
| ret = bdrv_pread(bs->file, 128, &s->block_size, 4); |
| if (ret < 0) { |
| return ret; |
| } |
| s->block_size = be32_to_cpu(s->block_size); |
| if (s->block_size % 512) { |
| error_setg(errp, "block_size %" PRIu32 " must be a multiple of 512", |
| s->block_size); |
| return -EINVAL; |
| } |
| if (s->block_size == 0) { |
| error_setg(errp, "block_size cannot be zero"); |
| return -EINVAL; |
| } |
| |
| /* cloop's create_compressed_fs.c warns about block sizes beyond 256 KB but |
| * we can accept more. Prevent ridiculous values like 4 GB - 1 since we |
| * need a buffer this big. |
| */ |
| if (s->block_size > MAX_BLOCK_SIZE) { |
| error_setg(errp, "block_size %" PRIu32 " must be %u MB or less", |
| s->block_size, |
| MAX_BLOCK_SIZE / (1024 * 1024)); |
| return -EINVAL; |
| } |
| |
| ret = bdrv_pread(bs->file, 128 + 4, &s->n_blocks, 4); |
| if (ret < 0) { |
| return ret; |
| } |
| s->n_blocks = be32_to_cpu(s->n_blocks); |
| |
| /* read offsets */ |
| if (s->n_blocks > (UINT32_MAX - 1) / sizeof(uint64_t)) { |
| /* Prevent integer overflow */ |
| error_setg(errp, "n_blocks %" PRIu32 " must be %zu or less", |
| s->n_blocks, |
| (UINT32_MAX - 1) / sizeof(uint64_t)); |
| return -EINVAL; |
| } |
| offsets_size = (s->n_blocks + 1) * sizeof(uint64_t); |
| if (offsets_size > 512 * 1024 * 1024) { |
| /* Prevent ridiculous offsets_size which causes memory allocation to |
| * fail or overflows bdrv_pread() size. In practice the 512 MB |
| * offsets[] limit supports 16 TB images at 256 KB block size. |
| */ |
| error_setg(errp, "image requires too many offsets, " |
| "try increasing block size"); |
| return -EINVAL; |
| } |
| |
| s->offsets = g_try_malloc(offsets_size); |
| if (s->offsets == NULL) { |
| error_setg(errp, "Could not allocate offsets table"); |
| return -ENOMEM; |
| } |
| |
| ret = bdrv_pread(bs->file, 128 + 4 + 4, s->offsets, offsets_size); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| for (i = 0; i < s->n_blocks + 1; i++) { |
| uint64_t size; |
| |
| s->offsets[i] = be64_to_cpu(s->offsets[i]); |
| if (i == 0) { |
| continue; |
| } |
| |
| if (s->offsets[i] < s->offsets[i - 1]) { |
| error_setg(errp, "offsets not monotonically increasing at " |
| "index %" PRIu32 ", image file is corrupt", i); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| size = s->offsets[i] - s->offsets[i - 1]; |
| |
| /* Compressed blocks should be smaller than the uncompressed block size |
| * but maybe compression performed poorly so the compressed block is |
| * actually bigger. Clamp down on unrealistic values to prevent |
| * ridiculous s->compressed_block allocation. |
| */ |
| if (size > 2 * MAX_BLOCK_SIZE) { |
| error_setg(errp, "invalid compressed block size at index %" PRIu32 |
| ", image file is corrupt", i); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (size > max_compressed_block_size) { |
| max_compressed_block_size = size; |
| } |
| } |
| |
| /* initialize zlib engine */ |
| s->compressed_block = g_try_malloc(max_compressed_block_size + 1); |
| if (s->compressed_block == NULL) { |
| error_setg(errp, "Could not allocate compressed_block"); |
| ret = -ENOMEM; |
| goto fail; |
| } |
| |
| s->uncompressed_block = g_try_malloc(s->block_size); |
| if (s->uncompressed_block == NULL) { |
| error_setg(errp, "Could not allocate uncompressed_block"); |
| ret = -ENOMEM; |
| goto fail; |
| } |
| |
| if (inflateInit(&s->zstream) != Z_OK) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| s->current_block = s->n_blocks; |
| |
| s->sectors_per_block = s->block_size/512; |
| bs->total_sectors = s->n_blocks * s->sectors_per_block; |
| qemu_co_mutex_init(&s->lock); |
| return 0; |
| |
| fail: |
| g_free(s->offsets); |
| g_free(s->compressed_block); |
| g_free(s->uncompressed_block); |
| return ret; |
| } |
| |
| static void cloop_refresh_limits(BlockDriverState *bs, Error **errp) |
| { |
| bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */ |
| } |
| |
| static inline int cloop_read_block(BlockDriverState *bs, int block_num) |
| { |
| BDRVCloopState *s = bs->opaque; |
| |
| if (s->current_block != block_num) { |
| int ret; |
| uint32_t bytes = s->offsets[block_num + 1] - s->offsets[block_num]; |
| |
| ret = bdrv_pread(bs->file, s->offsets[block_num], |
| s->compressed_block, bytes); |
| if (ret != bytes) { |
| return -1; |
| } |
| |
| s->zstream.next_in = s->compressed_block; |
| s->zstream.avail_in = bytes; |
| s->zstream.next_out = s->uncompressed_block; |
| s->zstream.avail_out = s->block_size; |
| 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 != s->block_size) { |
| return -1; |
| } |
| |
| s->current_block = block_num; |
| } |
| return 0; |
| } |
| |
| static int coroutine_fn |
| cloop_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, int flags) |
| { |
| BDRVCloopState *s = bs->opaque; |
| uint64_t sector_num = offset >> BDRV_SECTOR_BITS; |
| int nb_sectors = bytes >> BDRV_SECTOR_BITS; |
| int ret, i; |
| |
| assert(QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)); |
| assert(QEMU_IS_ALIGNED(bytes, BDRV_SECTOR_SIZE)); |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| for (i = 0; i < nb_sectors; i++) { |
| void *data; |
| uint32_t sector_offset_in_block = |
| ((sector_num + i) % s->sectors_per_block), |
| block_num = (sector_num + i) / s->sectors_per_block; |
| if (cloop_read_block(bs, block_num) != 0) { |
| ret = -EIO; |
| goto fail; |
| } |
| |
| data = s->uncompressed_block + sector_offset_in_block * 512; |
| qemu_iovec_from_buf(qiov, i * 512, data, 512); |
| } |
| |
| ret = 0; |
| fail: |
| qemu_co_mutex_unlock(&s->lock); |
| |
| return ret; |
| } |
| |
| static void cloop_close(BlockDriverState *bs) |
| { |
| BDRVCloopState *s = bs->opaque; |
| g_free(s->offsets); |
| g_free(s->compressed_block); |
| g_free(s->uncompressed_block); |
| inflateEnd(&s->zstream); |
| } |
| |
| static BlockDriver bdrv_cloop = { |
| .format_name = "cloop", |
| .instance_size = sizeof(BDRVCloopState), |
| .bdrv_probe = cloop_probe, |
| .bdrv_open = cloop_open, |
| .bdrv_child_perm = bdrv_format_default_perms, |
| .bdrv_refresh_limits = cloop_refresh_limits, |
| .bdrv_co_preadv = cloop_co_preadv, |
| .bdrv_close = cloop_close, |
| .is_format = true, |
| }; |
| |
| static void bdrv_cloop_init(void) |
| { |
| bdrv_register(&bdrv_cloop); |
| } |
| |
| block_init(bdrv_cloop_init); |