Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 334 insertions, 0 deletions

diff --git a/src/import/qcow2-util.c b/src/import/qcow2-util.c
new file mode 100644
index 0000000..e927b60
--- /dev/null
+++ b/src/import/qcow2-util.c
@@ -0,0 +1,334 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <zlib.h>
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "qcow2-util.h"
+#include "sparse-endian.h"
+#include "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 (!IN_SET(HEADER_VERSION(header), 2, 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;
+}