+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2015 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <zlib.h>
-
-#include "util.h"
-#include "sparse-endian.h"
-#include "qcow2-util.h"
-#include "btrfs-util.h"
-
-#define QCOW2_MAGIC 0x514649fb
-
-#define QCOW2_COPIED (1ULL << 63)
-#define QCOW2_COMPRESSED (1ULL << 62)
-#define QCOW2_ZERO (1ULL << 0)
-
-typedef struct _packed_ Header {
- be32_t magic;
- be32_t version;
-
- be64_t backing_file_offset;
- be32_t backing_file_size;
-
- be32_t cluster_bits;
- be64_t size;
- be32_t crypt_method;
-
- be32_t l1_size;
- be64_t l1_table_offset;
-
- be64_t refcount_table_offset;
- be32_t refcount_table_clusters;
-
- be32_t nb_snapshots;
- be64_t snapshots_offset;
-
- /* The remainder is only present on QCOW3 */
- be64_t incompatible_features;
- be64_t compatible_features;
- be64_t autoclear_features;
-
- be32_t refcount_order;
- be32_t header_length;
-} Header;
-
-#define HEADER_MAGIC(header) be32toh((header)->magic)
-#define HEADER_VERSION(header) be32toh((header)->version)
-#define HEADER_CLUSTER_BITS(header) be32toh((header)->cluster_bits)
-#define HEADER_CLUSTER_SIZE(header) (1ULL << HEADER_CLUSTER_BITS(header))
-#define HEADER_L2_BITS(header) (HEADER_CLUSTER_BITS(header) - 3)
-#define HEADER_SIZE(header) be64toh((header)->size)
-#define HEADER_CRYPT_METHOD(header) be32toh((header)->crypt_method)
-#define HEADER_L1_SIZE(header) be32toh((header)->l1_size)
-#define HEADER_L2_SIZE(header) (HEADER_CLUSTER_SIZE(header)/sizeof(uint64_t))
-#define HEADER_L1_TABLE_OFFSET(header) be64toh((header)->l1_table_offset)
-
-static uint32_t HEADER_HEADER_LENGTH(const Header *h) {
- if (HEADER_VERSION(h) < 3)
- return offsetof(Header, incompatible_features);
-
- return be32toh(h->header_length);
-}
-
-static int copy_cluster(
- int sfd, uint64_t soffset,
- int dfd, uint64_t doffset,
- uint64_t cluster_size,
- void *buffer) {
-
- ssize_t l;
- int r;
-
- r = btrfs_clone_range(sfd, soffset, dfd, doffset, cluster_size);
- if (r >= 0)
- return r;
-
- l = pread(sfd, buffer, cluster_size, soffset);
- if (l < 0)
- return -errno;
- if ((uint64_t) l != cluster_size)
- return -EIO;
-
- l = pwrite(dfd, buffer, cluster_size, doffset);
- if (l < 0)
- return -errno;
- if ((uint64_t) l != cluster_size)
- return -EIO;
-
- return 0;
-}
-
-static int decompress_cluster(
- int sfd, uint64_t soffset,
- int dfd, uint64_t doffset,
- uint64_t compressed_size,
- uint64_t cluster_size,
- void *buffer1,
- void *buffer2) {
-
- _cleanup_free_ void *large_buffer = NULL;
- z_stream s = {};
- uint64_t sz;
- ssize_t l;
- int r;
-
- if (compressed_size > cluster_size) {
- /* The usual cluster buffer doesn't suffice, let's
- * allocate a larger one, temporarily */
-
- large_buffer = malloc(compressed_size);
- if (!large_buffer)
- return -ENOMEM;
-
- buffer1 = large_buffer;
- }
-
- l = pread(sfd, buffer1, compressed_size, soffset);
- if (l < 0)
- return -errno;
- if ((uint64_t) l != compressed_size)
- return -EIO;
-
- s.next_in = buffer1;
- s.avail_in = compressed_size;
- s.next_out = buffer2;
- s.avail_out = cluster_size;
-
- r = inflateInit2(&s, -12);
- if (r != Z_OK)
- return -EIO;
-
- r = inflate(&s, Z_FINISH);
- sz = (uint8_t*) s.next_out - (uint8_t*) buffer2;
- inflateEnd(&s);
- if (r != Z_STREAM_END || sz != cluster_size)
- return -EIO;
-
- l = pwrite(dfd, buffer2, cluster_size, doffset);
- if (l < 0)
- return -errno;
- if ((uint64_t) l != cluster_size)
- return -EIO;
-
- return 0;
-}
-
-static int normalize_offset(
- const Header *header,
- uint64_t p,
- uint64_t *ret,
- bool *compressed,
- uint64_t *compressed_size) {
-
- uint64_t q;
-
- q = be64toh(p);
-
- if (q & QCOW2_COMPRESSED) {
- uint64_t sz, csize_shift, csize_mask;
-
- if (!compressed)
- return -EOPNOTSUPP;
-
- csize_shift = 64 - 2 - (HEADER_CLUSTER_BITS(header) - 8);
- csize_mask = (1ULL << (HEADER_CLUSTER_BITS(header) - 8)) - 1;
- sz = (((q >> csize_shift) & csize_mask) + 1) * 512 - (q & 511);
- q &= ((1ULL << csize_shift) - 1);
-
- if (compressed_size)
- *compressed_size = sz;
-
- *compressed = true;
-
- } else {
- if (compressed) {
- *compressed = false;
- *compressed_size = 0;
- }
-
- if (q & QCOW2_ZERO) {
- /* We make no distinction between zero blocks and holes */
- *ret = 0;
- return 0;
- }
-
- q &= ~QCOW2_COPIED;
- }
-
- *ret = q;
- return q > 0; /* returns positive if not a hole */
-}
-
-static int verify_header(const Header *header) {
- assert(header);
-
- if (HEADER_MAGIC(header) != QCOW2_MAGIC)
- return -EBADMSG;
-
- if (HEADER_VERSION(header) != 2 &&
- HEADER_VERSION(header) != 3)
- return -EOPNOTSUPP;
-
- if (HEADER_CRYPT_METHOD(header) != 0)
- return -EOPNOTSUPP;
-
- if (HEADER_CLUSTER_BITS(header) < 9) /* 512K */
- return -EBADMSG;
-
- if (HEADER_CLUSTER_BITS(header) > 21) /* 2MB */
- return -EBADMSG;
-
- if (HEADER_SIZE(header) % HEADER_CLUSTER_SIZE(header) != 0)
- return -EBADMSG;
-
- if (HEADER_L1_SIZE(header) > 32*1024*1024) /* 32MB */
- return -EBADMSG;
-
- if (HEADER_VERSION(header) == 3) {
-
- if (header->incompatible_features != 0)
- return -EOPNOTSUPP;
-
- if (HEADER_HEADER_LENGTH(header) < sizeof(Header))
- return -EBADMSG;
- }
-
- return 0;
-}
-
-int qcow2_convert(int qcow2_fd, int raw_fd) {
- _cleanup_free_ void *buffer1 = NULL, *buffer2 = NULL;
- _cleanup_free_ be64_t *l1_table = NULL, *l2_table = NULL;
- uint64_t sz, i;
- Header header;
- ssize_t l;
- int r;
-
- l = pread(qcow2_fd, &header, sizeof(header), 0);
- if (l < 0)
- return -errno;
- if (l != sizeof(header))
- return -EIO;
-
- r = verify_header(&header);
- if (r < 0)
- return r;
-
- l1_table = new(be64_t, HEADER_L1_SIZE(&header));
- if (!l1_table)
- return -ENOMEM;
-
- l2_table = malloc(HEADER_CLUSTER_SIZE(&header));
- if (!l2_table)
- return -ENOMEM;
-
- buffer1 = malloc(HEADER_CLUSTER_SIZE(&header));
- if (!buffer1)
- return -ENOMEM;
-
- buffer2 = malloc(HEADER_CLUSTER_SIZE(&header));
- if (!buffer2)
- return -ENOMEM;
-
- /* Empty the file if it exists, we rely on zero bits */
- if (ftruncate(raw_fd, 0) < 0)
- return -errno;
-
- if (ftruncate(raw_fd, HEADER_SIZE(&header)) < 0)
- return -errno;
-
- sz = sizeof(uint64_t) * HEADER_L1_SIZE(&header);
- l = pread(qcow2_fd, l1_table, sz, HEADER_L1_TABLE_OFFSET(&header));
- if (l < 0)
- return -errno;
- if ((uint64_t) l != sz)
- return -EIO;
-
- for (i = 0; i < HEADER_L1_SIZE(&header); i ++) {
- uint64_t l2_begin, j;
-
- r = normalize_offset(&header, l1_table[i], &l2_begin, NULL, NULL);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- l = pread(qcow2_fd, l2_table, HEADER_CLUSTER_SIZE(&header), l2_begin);
- if (l < 0)
- return -errno;
- if ((uint64_t) l != HEADER_CLUSTER_SIZE(&header))
- return -EIO;
-
- for (j = 0; j < HEADER_L2_SIZE(&header); j++) {
- uint64_t data_begin, p, compressed_size;
- bool compressed;
-
- p = ((i << HEADER_L2_BITS(&header)) + j) << HEADER_CLUSTER_BITS(&header);
-
- r = normalize_offset(&header, l2_table[j], &data_begin, &compressed, &compressed_size);
- if (r < 0)
- return r;
- if (r == 0)
- continue;
-
- if (compressed)
- r = decompress_cluster(
- qcow2_fd, data_begin,
- raw_fd, p,
- compressed_size, HEADER_CLUSTER_SIZE(&header),
- buffer1, buffer2);
- else
- r = copy_cluster(
- qcow2_fd, data_begin,
- raw_fd, p,
- HEADER_CLUSTER_SIZE(&header), buffer1);
- if (r < 0)
- return r;
- }
- }
-
- return 0;
-}
-
-int qcow2_detect(int fd) {
- be32_t id;
- ssize_t l;
-
- l = pread(fd, &id, sizeof(id), 0);
- if (l < 0)
- return -errno;
- if (l != sizeof(id))
- return -EIO;
-
- return htobe32(QCOW2_MAGIC) == id;
-}
~ianmdlvl / elogind.git / blobdiff