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/*
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* Block driver for the QCOW format
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*
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* Copyright (c) 2004 Fabrice Bellard
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "vl.h" |
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#include "block_int.h" |
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#include <zlib.h> |
27 |
#include "aes.h" |
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|
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/**************************************************************/
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/* QEMU COW block driver with compression and encryption support */
|
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|
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#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) |
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#define QCOW_VERSION 1 |
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|
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#define QCOW_CRYPT_NONE 0 |
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#define QCOW_CRYPT_AES 1 |
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|
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#define QCOW_OFLAG_COMPRESSED (1LL << 63) |
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|
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typedef struct QCowHeader { |
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uint32_t magic; |
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uint32_t version; |
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uint64_t backing_file_offset; |
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uint32_t backing_file_size; |
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uint32_t mtime; |
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uint64_t size; /* in bytes */
|
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uint8_t cluster_bits; |
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uint8_t l2_bits; |
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uint32_t crypt_method; |
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uint64_t l1_table_offset; |
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} QCowHeader; |
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|
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#define L2_CACHE_SIZE 16 |
54 |
|
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typedef struct BDRVQcowState { |
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int fd;
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int cluster_bits;
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int cluster_size;
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int cluster_sectors;
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int l2_bits;
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int l2_size;
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int l1_size;
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uint64_t cluster_offset_mask; |
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uint64_t l1_table_offset; |
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uint64_t *l1_table; |
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uint64_t *l2_cache; |
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uint64_t l2_cache_offsets[L2_CACHE_SIZE]; |
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uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
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uint8_t *cluster_cache; |
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uint8_t *cluster_data; |
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uint64_t cluster_cache_offset; |
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uint32_t crypt_method; /* current crypt method, 0 if no key yet */
|
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uint32_t crypt_method_header; |
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AES_KEY aes_encrypt_key; |
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AES_KEY aes_decrypt_key; |
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} BDRVQcowState; |
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|
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static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset); |
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|
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static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename) |
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{ |
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const QCowHeader *cow_header = (const void *)buf; |
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|
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if (buf_size >= sizeof(QCowHeader) && |
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be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
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be32_to_cpu(cow_header->version) == QCOW_VERSION) |
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return 100; |
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else
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return 0; |
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} |
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|
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static int qcow_open(BlockDriverState *bs, const char *filename) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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int fd, len, i, shift;
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QCowHeader header; |
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|
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fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE); |
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if (fd < 0) { |
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fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); |
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if (fd < 0) |
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return -1; |
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} |
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s->fd = fd; |
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if (read(fd, &header, sizeof(header)) != sizeof(header)) |
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goto fail;
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be32_to_cpus(&header.magic); |
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be32_to_cpus(&header.version); |
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be64_to_cpus(&header.backing_file_offset); |
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be32_to_cpus(&header.backing_file_size); |
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be32_to_cpus(&header.mtime); |
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be64_to_cpus(&header.size); |
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be32_to_cpus(&header.crypt_method); |
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be64_to_cpus(&header.l1_table_offset); |
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|
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if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
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goto fail;
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if (header.size <= 1 || header.cluster_bits < 9) |
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goto fail;
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if (header.crypt_method > QCOW_CRYPT_AES)
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goto fail;
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s->crypt_method_header = header.crypt_method; |
123 |
if (s->crypt_method_header)
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bs->encrypted = 1;
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s->cluster_bits = header.cluster_bits; |
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s->cluster_size = 1 << s->cluster_bits;
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s->cluster_sectors = 1 << (s->cluster_bits - 9); |
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s->l2_bits = header.l2_bits; |
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s->l2_size = 1 << s->l2_bits;
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bs->total_sectors = header.size / 512;
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s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1; |
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|
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/* read the level 1 table */
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shift = s->cluster_bits + s->l2_bits; |
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s->l1_size = (header.size + (1LL << shift) - 1) >> shift; |
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|
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s->l1_table_offset = header.l1_table_offset; |
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s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
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if (!s->l1_table)
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goto fail;
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lseek(fd, s->l1_table_offset, SEEK_SET); |
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if (read(fd, s->l1_table, s->l1_size * sizeof(uint64_t)) != |
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s->l1_size * sizeof(uint64_t))
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goto fail;
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for(i = 0;i < s->l1_size; i++) { |
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be64_to_cpus(&s->l1_table[i]); |
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} |
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/* alloc L2 cache */
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s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
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if (!s->l2_cache)
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goto fail;
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s->cluster_cache = qemu_malloc(s->cluster_size); |
153 |
if (!s->cluster_cache)
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goto fail;
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s->cluster_data = qemu_malloc(s->cluster_size); |
156 |
if (!s->cluster_data)
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goto fail;
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s->cluster_cache_offset = -1;
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|
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/* read the backing file name */
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if (header.backing_file_offset != 0) { |
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len = header.backing_file_size; |
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if (len > 1023) |
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len = 1023;
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lseek(fd, header.backing_file_offset, SEEK_SET); |
166 |
if (read(fd, bs->backing_file, len) != len)
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goto fail;
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bs->backing_file[len] = '\0';
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} |
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return 0; |
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fail:
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qemu_free(s->l1_table); |
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qemu_free(s->l2_cache); |
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qemu_free(s->cluster_cache); |
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qemu_free(s->cluster_data); |
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close(fd); |
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return -1; |
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} |
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static int qcow_set_key(BlockDriverState *bs, const char *key) |
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{ |
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BDRVQcowState *s = bs->opaque; |
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uint8_t keybuf[16];
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int len, i;
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memset(keybuf, 0, 16); |
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len = strlen(key); |
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if (len > 16) |
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len = 16;
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/* XXX: we could compress the chars to 7 bits to increase
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entropy */
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for(i = 0;i < len;i++) { |
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keybuf[i] = key[i]; |
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} |
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s->crypt_method = s->crypt_method_header; |
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|
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if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
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return -1; |
200 |
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
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return -1; |
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#if 0
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/* test */
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{
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uint8_t in[16];
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uint8_t out[16];
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uint8_t tmp[16];
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for(i=0;i<16;i++)
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in[i] = i;
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AES_encrypt(in, tmp, &s->aes_encrypt_key);
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AES_decrypt(tmp, out, &s->aes_decrypt_key);
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for(i = 0; i < 16; i++)
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printf(" %02x", tmp[i]);
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printf("\n");
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for(i = 0; i < 16; i++)
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printf(" %02x", out[i]);
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printf("\n");
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}
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#endif
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return 0; |
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} |
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/* The crypt function is compatible with the linux cryptoloop
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algorithm for < 4 GB images. NOTE: out_buf == in_buf is
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supported */
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static void encrypt_sectors(BDRVQcowState *s, int64_t sector_num, |
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uint8_t *out_buf, const uint8_t *in_buf,
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int nb_sectors, int enc, |
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const AES_KEY *key)
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{ |
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union {
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uint64_t ll[2];
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uint8_t b[16];
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} ivec; |
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int i;
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|
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for(i = 0; i < nb_sectors; i++) { |
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ivec.ll[0] = cpu_to_le64(sector_num);
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ivec.ll[1] = 0; |
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AES_cbc_encrypt(in_buf, out_buf, 512, key,
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ivec.b, enc); |
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sector_num++; |
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in_buf += 512;
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out_buf += 512;
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} |
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} |
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|
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/* 'allocate' is:
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*
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* 0 to not allocate.
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*
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* 1 to allocate a normal cluster (for sector indexes 'n_start' to
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* 'n_end')
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*
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* 2 to allocate a compressed cluster of size
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* 'compressed_size'. 'compressed_size' must be > 0 and <
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* cluster_size
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*
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* return 0 if not allocated.
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*/
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static uint64_t get_cluster_offset(BlockDriverState *bs,
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uint64_t offset, int allocate,
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int compressed_size,
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int n_start, int n_end) |
265 |
{ |
266 |
BDRVQcowState *s = bs->opaque; |
267 |
int min_index, i, j, l1_index, l2_index;
|
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uint64_t l2_offset, *l2_table, cluster_offset, tmp; |
269 |
uint32_t min_count; |
270 |
int new_l2_table;
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271 |
|
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l1_index = offset >> (s->l2_bits + s->cluster_bits); |
273 |
l2_offset = s->l1_table[l1_index]; |
274 |
new_l2_table = 0;
|
275 |
if (!l2_offset) {
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276 |
if (!allocate)
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277 |
return 0; |
278 |
/* allocate a new l2 entry */
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279 |
l2_offset = lseek(s->fd, 0, SEEK_END);
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280 |
/* round to cluster size */
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281 |
l2_offset = (l2_offset + s->cluster_size - 1) & ~(s->cluster_size - 1); |
282 |
/* update the L1 entry */
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283 |
s->l1_table[l1_index] = l2_offset; |
284 |
tmp = cpu_to_be64(l2_offset); |
285 |
lseek(s->fd, s->l1_table_offset + l1_index * sizeof(tmp), SEEK_SET);
|
286 |
if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp)) |
287 |
return 0; |
288 |
new_l2_table = 1;
|
289 |
} |
290 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
291 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
292 |
/* increment the hit count */
|
293 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
294 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
295 |
s->l2_cache_counts[j] >>= 1;
|
296 |
} |
297 |
} |
298 |
l2_table = s->l2_cache + (i << s->l2_bits); |
299 |
goto found;
|
300 |
} |
301 |
} |
302 |
/* not found: load a new entry in the least used one */
|
303 |
min_index = 0;
|
304 |
min_count = 0xffffffff;
|
305 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
306 |
if (s->l2_cache_counts[i] < min_count) {
|
307 |
min_count = s->l2_cache_counts[i]; |
308 |
min_index = i; |
309 |
} |
310 |
} |
311 |
l2_table = s->l2_cache + (min_index << s->l2_bits); |
312 |
lseek(s->fd, l2_offset, SEEK_SET); |
313 |
if (new_l2_table) {
|
314 |
memset(l2_table, 0, s->l2_size * sizeof(uint64_t)); |
315 |
if (write(s->fd, l2_table, s->l2_size * sizeof(uint64_t)) != |
316 |
s->l2_size * sizeof(uint64_t))
|
317 |
return 0; |
318 |
} else {
|
319 |
if (read(s->fd, l2_table, s->l2_size * sizeof(uint64_t)) != |
320 |
s->l2_size * sizeof(uint64_t))
|
321 |
return 0; |
322 |
} |
323 |
s->l2_cache_offsets[min_index] = l2_offset; |
324 |
s->l2_cache_counts[min_index] = 1;
|
325 |
found:
|
326 |
l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
|
327 |
cluster_offset = be64_to_cpu(l2_table[l2_index]); |
328 |
if (!cluster_offset ||
|
329 |
((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
|
330 |
if (!allocate)
|
331 |
return 0; |
332 |
/* allocate a new cluster */
|
333 |
if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
|
334 |
(n_end - n_start) < s->cluster_sectors) { |
335 |
/* if the cluster is already compressed, we must
|
336 |
decompress it in the case it is not completely
|
337 |
overwritten */
|
338 |
if (decompress_cluster(s, cluster_offset) < 0) |
339 |
return 0; |
340 |
cluster_offset = lseek(s->fd, 0, SEEK_END);
|
341 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
342 |
~(s->cluster_size - 1);
|
343 |
/* write the cluster content */
|
344 |
lseek(s->fd, cluster_offset, SEEK_SET); |
345 |
if (write(s->fd, s->cluster_cache, s->cluster_size) !=
|
346 |
s->cluster_size) |
347 |
return -1; |
348 |
} else {
|
349 |
cluster_offset = lseek(s->fd, 0, SEEK_END);
|
350 |
if (allocate == 1) { |
351 |
/* round to cluster size */
|
352 |
cluster_offset = (cluster_offset + s->cluster_size - 1) &
|
353 |
~(s->cluster_size - 1);
|
354 |
ftruncate(s->fd, cluster_offset + s->cluster_size); |
355 |
/* if encrypted, we must initialize the cluster
|
356 |
content which won't be written */
|
357 |
if (s->crypt_method &&
|
358 |
(n_end - n_start) < s->cluster_sectors) { |
359 |
uint64_t start_sect; |
360 |
start_sect = (offset & ~(s->cluster_size - 1)) >> 9; |
361 |
memset(s->cluster_data + 512, 0xaa, 512); |
362 |
for(i = 0; i < s->cluster_sectors; i++) { |
363 |
if (i < n_start || i >= n_end) {
|
364 |
encrypt_sectors(s, start_sect + i, |
365 |
s->cluster_data, |
366 |
s->cluster_data + 512, 1, 1, |
367 |
&s->aes_encrypt_key); |
368 |
lseek(s->fd, cluster_offset + i * 512, SEEK_SET);
|
369 |
if (write(s->fd, s->cluster_data, 512) != 512) |
370 |
return -1; |
371 |
} |
372 |
} |
373 |
} |
374 |
} else {
|
375 |
cluster_offset |= QCOW_OFLAG_COMPRESSED | |
376 |
(uint64_t)compressed_size << (63 - s->cluster_bits);
|
377 |
} |
378 |
} |
379 |
/* update L2 table */
|
380 |
tmp = cpu_to_be64(cluster_offset); |
381 |
l2_table[l2_index] = tmp; |
382 |
lseek(s->fd, l2_offset + l2_index * sizeof(tmp), SEEK_SET);
|
383 |
if (write(s->fd, &tmp, sizeof(tmp)) != sizeof(tmp)) |
384 |
return 0; |
385 |
} |
386 |
return cluster_offset;
|
387 |
} |
388 |
|
389 |
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num, |
390 |
int nb_sectors, int *pnum) |
391 |
{ |
392 |
BDRVQcowState *s = bs->opaque; |
393 |
int index_in_cluster, n;
|
394 |
uint64_t cluster_offset; |
395 |
|
396 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
397 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
398 |
n = s->cluster_sectors - index_in_cluster; |
399 |
if (n > nb_sectors)
|
400 |
n = nb_sectors; |
401 |
*pnum = n; |
402 |
return (cluster_offset != 0); |
403 |
} |
404 |
|
405 |
static int decompress_buffer(uint8_t *out_buf, int out_buf_size, |
406 |
const uint8_t *buf, int buf_size) |
407 |
{ |
408 |
z_stream strm1, *strm = &strm1; |
409 |
int ret, out_len;
|
410 |
|
411 |
memset(strm, 0, sizeof(*strm)); |
412 |
|
413 |
strm->next_in = (uint8_t *)buf; |
414 |
strm->avail_in = buf_size; |
415 |
strm->next_out = out_buf; |
416 |
strm->avail_out = out_buf_size; |
417 |
|
418 |
ret = inflateInit2(strm, -12);
|
419 |
if (ret != Z_OK)
|
420 |
return -1; |
421 |
ret = inflate(strm, Z_FINISH); |
422 |
out_len = strm->next_out - out_buf; |
423 |
if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
|
424 |
out_len != out_buf_size) { |
425 |
inflateEnd(strm); |
426 |
return -1; |
427 |
} |
428 |
inflateEnd(strm); |
429 |
return 0; |
430 |
} |
431 |
|
432 |
static int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset) |
433 |
{ |
434 |
int ret, csize;
|
435 |
uint64_t coffset; |
436 |
|
437 |
coffset = cluster_offset & s->cluster_offset_mask; |
438 |
if (s->cluster_cache_offset != coffset) {
|
439 |
csize = cluster_offset >> (63 - s->cluster_bits);
|
440 |
csize &= (s->cluster_size - 1);
|
441 |
lseek(s->fd, coffset, SEEK_SET); |
442 |
ret = read(s->fd, s->cluster_data, csize); |
443 |
if (ret != csize)
|
444 |
return -1; |
445 |
if (decompress_buffer(s->cluster_cache, s->cluster_size,
|
446 |
s->cluster_data, csize) < 0) {
|
447 |
return -1; |
448 |
} |
449 |
s->cluster_cache_offset = coffset; |
450 |
} |
451 |
return 0; |
452 |
} |
453 |
|
454 |
static int qcow_read(BlockDriverState *bs, int64_t sector_num, |
455 |
uint8_t *buf, int nb_sectors)
|
456 |
{ |
457 |
BDRVQcowState *s = bs->opaque; |
458 |
int ret, index_in_cluster, n;
|
459 |
uint64_t cluster_offset; |
460 |
|
461 |
while (nb_sectors > 0) { |
462 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 0, 0, 0, 0); |
463 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
464 |
n = s->cluster_sectors - index_in_cluster; |
465 |
if (n > nb_sectors)
|
466 |
n = nb_sectors; |
467 |
if (!cluster_offset) {
|
468 |
memset(buf, 0, 512 * n); |
469 |
} else if (cluster_offset & QCOW_OFLAG_COMPRESSED) { |
470 |
if (decompress_cluster(s, cluster_offset) < 0) |
471 |
return -1; |
472 |
memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n); |
473 |
} else {
|
474 |
lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
|
475 |
ret = read(s->fd, buf, n * 512);
|
476 |
if (ret != n * 512) |
477 |
return -1; |
478 |
if (s->crypt_method) {
|
479 |
encrypt_sectors(s, sector_num, buf, buf, n, 0,
|
480 |
&s->aes_decrypt_key); |
481 |
} |
482 |
} |
483 |
nb_sectors -= n; |
484 |
sector_num += n; |
485 |
buf += n * 512;
|
486 |
} |
487 |
return 0; |
488 |
} |
489 |
|
490 |
static int qcow_write(BlockDriverState *bs, int64_t sector_num, |
491 |
const uint8_t *buf, int nb_sectors) |
492 |
{ |
493 |
BDRVQcowState *s = bs->opaque; |
494 |
int ret, index_in_cluster, n;
|
495 |
uint64_t cluster_offset; |
496 |
|
497 |
while (nb_sectors > 0) { |
498 |
index_in_cluster = sector_num & (s->cluster_sectors - 1);
|
499 |
n = s->cluster_sectors - index_in_cluster; |
500 |
if (n > nb_sectors)
|
501 |
n = nb_sectors; |
502 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 1, 0, |
503 |
index_in_cluster, |
504 |
index_in_cluster + n); |
505 |
if (!cluster_offset)
|
506 |
return -1; |
507 |
lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
|
508 |
if (s->crypt_method) {
|
509 |
encrypt_sectors(s, sector_num, s->cluster_data, buf, n, 1,
|
510 |
&s->aes_encrypt_key); |
511 |
ret = write(s->fd, s->cluster_data, n * 512);
|
512 |
} else {
|
513 |
ret = write(s->fd, buf, n * 512);
|
514 |
} |
515 |
if (ret != n * 512) |
516 |
return -1; |
517 |
nb_sectors -= n; |
518 |
sector_num += n; |
519 |
buf += n * 512;
|
520 |
} |
521 |
s->cluster_cache_offset = -1; /* disable compressed cache */ |
522 |
return 0; |
523 |
} |
524 |
|
525 |
static void qcow_close(BlockDriverState *bs) |
526 |
{ |
527 |
BDRVQcowState *s = bs->opaque; |
528 |
qemu_free(s->l1_table); |
529 |
qemu_free(s->l2_cache); |
530 |
qemu_free(s->cluster_cache); |
531 |
qemu_free(s->cluster_data); |
532 |
close(s->fd); |
533 |
} |
534 |
|
535 |
static int qcow_create(const char *filename, int64_t total_size, |
536 |
const char *backing_file, int flags) |
537 |
{ |
538 |
int fd, header_size, backing_filename_len, l1_size, i, shift;
|
539 |
QCowHeader header; |
540 |
char backing_filename[1024]; |
541 |
uint64_t tmp; |
542 |
struct stat st;
|
543 |
|
544 |
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE, |
545 |
0644);
|
546 |
if (fd < 0) |
547 |
return -1; |
548 |
memset(&header, 0, sizeof(header)); |
549 |
header.magic = cpu_to_be32(QCOW_MAGIC); |
550 |
header.version = cpu_to_be32(QCOW_VERSION); |
551 |
header.size = cpu_to_be64(total_size * 512);
|
552 |
header_size = sizeof(header);
|
553 |
backing_filename_len = 0;
|
554 |
if (backing_file) {
|
555 |
if (strcmp(backing_file, "fat:")) { |
556 |
const char *p; |
557 |
/* XXX: this is a hack: we do not attempt to check for URL
|
558 |
like syntax */
|
559 |
p = strchr(backing_file, ':');
|
560 |
if (p && (p - backing_file) >= 2) { |
561 |
/* URL like but exclude "c:" like filenames */
|
562 |
pstrcpy(backing_filename, sizeof(backing_filename),
|
563 |
backing_file); |
564 |
} else {
|
565 |
realpath(backing_file, backing_filename); |
566 |
if (stat(backing_filename, &st) != 0) { |
567 |
return -1; |
568 |
} |
569 |
} |
570 |
header.backing_file_offset = cpu_to_be64(header_size); |
571 |
backing_filename_len = strlen(backing_filename); |
572 |
header.backing_file_size = cpu_to_be32(backing_filename_len); |
573 |
header_size += backing_filename_len; |
574 |
} else
|
575 |
backing_file = NULL;
|
576 |
header.mtime = cpu_to_be32(st.st_mtime); |
577 |
header.cluster_bits = 9; /* 512 byte cluster to avoid copying |
578 |
unmodifyed sectors */
|
579 |
header.l2_bits = 12; /* 32 KB L2 tables */ |
580 |
} else {
|
581 |
header.cluster_bits = 12; /* 4 KB clusters */ |
582 |
header.l2_bits = 9; /* 4 KB L2 tables */ |
583 |
} |
584 |
header_size = (header_size + 7) & ~7; |
585 |
shift = header.cluster_bits + header.l2_bits; |
586 |
l1_size = ((total_size * 512) + (1LL << shift) - 1) >> shift; |
587 |
|
588 |
header.l1_table_offset = cpu_to_be64(header_size); |
589 |
if (flags) {
|
590 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
591 |
} else {
|
592 |
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE); |
593 |
} |
594 |
|
595 |
/* write all the data */
|
596 |
write(fd, &header, sizeof(header));
|
597 |
if (backing_file) {
|
598 |
write(fd, backing_filename, backing_filename_len); |
599 |
} |
600 |
lseek(fd, header_size, SEEK_SET); |
601 |
tmp = 0;
|
602 |
for(i = 0;i < l1_size; i++) { |
603 |
write(fd, &tmp, sizeof(tmp));
|
604 |
} |
605 |
close(fd); |
606 |
return 0; |
607 |
} |
608 |
|
609 |
int qcow_make_empty(BlockDriverState *bs)
|
610 |
{ |
611 |
BDRVQcowState *s = bs->opaque; |
612 |
uint32_t l1_length = s->l1_size * sizeof(uint64_t);
|
613 |
|
614 |
memset(s->l1_table, 0, l1_length);
|
615 |
lseek(s->fd, s->l1_table_offset, SEEK_SET); |
616 |
if (write(s->fd, s->l1_table, l1_length) < 0) |
617 |
return -1; |
618 |
ftruncate(s->fd, s->l1_table_offset + l1_length); |
619 |
|
620 |
memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t)); |
621 |
memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t)); |
622 |
memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t)); |
623 |
|
624 |
return 0; |
625 |
} |
626 |
|
627 |
int qcow_get_cluster_size(BlockDriverState *bs)
|
628 |
{ |
629 |
BDRVQcowState *s = bs->opaque; |
630 |
if (bs->drv != &bdrv_qcow)
|
631 |
return -1; |
632 |
return s->cluster_size;
|
633 |
} |
634 |
|
635 |
/* XXX: put compressed sectors first, then all the cluster aligned
|
636 |
tables to avoid losing bytes in alignment */
|
637 |
int qcow_compress_cluster(BlockDriverState *bs, int64_t sector_num,
|
638 |
const uint8_t *buf)
|
639 |
{ |
640 |
BDRVQcowState *s = bs->opaque; |
641 |
z_stream strm; |
642 |
int ret, out_len;
|
643 |
uint8_t *out_buf; |
644 |
uint64_t cluster_offset; |
645 |
|
646 |
if (bs->drv != &bdrv_qcow)
|
647 |
return -1; |
648 |
|
649 |
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
650 |
if (!out_buf)
|
651 |
return -1; |
652 |
|
653 |
/* best compression, small window, no zlib header */
|
654 |
memset(&strm, 0, sizeof(strm)); |
655 |
ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
656 |
Z_DEFLATED, -12,
|
657 |
9, Z_DEFAULT_STRATEGY);
|
658 |
if (ret != 0) { |
659 |
qemu_free(out_buf); |
660 |
return -1; |
661 |
} |
662 |
|
663 |
strm.avail_in = s->cluster_size; |
664 |
strm.next_in = (uint8_t *)buf; |
665 |
strm.avail_out = s->cluster_size; |
666 |
strm.next_out = out_buf; |
667 |
|
668 |
ret = deflate(&strm, Z_FINISH); |
669 |
if (ret != Z_STREAM_END && ret != Z_OK) {
|
670 |
qemu_free(out_buf); |
671 |
deflateEnd(&strm); |
672 |
return -1; |
673 |
} |
674 |
out_len = strm.next_out - out_buf; |
675 |
|
676 |
deflateEnd(&strm); |
677 |
|
678 |
if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
|
679 |
/* could not compress: write normal cluster */
|
680 |
qcow_write(bs, sector_num, buf, s->cluster_sectors); |
681 |
} else {
|
682 |
cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, |
683 |
out_len, 0, 0); |
684 |
cluster_offset &= s->cluster_offset_mask; |
685 |
lseek(s->fd, cluster_offset, SEEK_SET); |
686 |
if (write(s->fd, out_buf, out_len) != out_len) {
|
687 |
qemu_free(out_buf); |
688 |
return -1; |
689 |
} |
690 |
} |
691 |
|
692 |
qemu_free(out_buf); |
693 |
return 0; |
694 |
} |
695 |
|
696 |
BlockDriver bdrv_qcow = { |
697 |
"qcow",
|
698 |
sizeof(BDRVQcowState),
|
699 |
qcow_probe, |
700 |
qcow_open, |
701 |
qcow_read, |
702 |
qcow_write, |
703 |
qcow_close, |
704 |
qcow_create, |
705 |
qcow_is_allocated, |
706 |
qcow_set_key, |
707 |
qcow_make_empty |
708 |
}; |
709 |
|
710 |
|