block/vhdx-endian.c

/*
 * Block driver for Hyper-V VHDX Images
 *
 * Copyright (c) 2013 Red Hat, Inc.,
 *
 * Authors:
 *  Jeff Cody <jcody@redhat.com>
 *
 *  This is based on the "VHDX Format Specification v1.00", published 8/25/2012
 *  by Microsoft:
 *      https://www.microsoft.com/en-us/download/details.aspx?id=34750
 *
 * This work is licensed under the terms of the GNU LGPL, version 2 or later.
 * See the COPYING.LIB file in the top-level directory.
 *
 */

#include "qemu/osdep.h"
#include "qemu-common.h"
#include "block/block_int.h"
#include "qemu/bswap.h"
#include "vhdx.h"

/*
 * All the VHDX formats on disk are little endian - the following
 * are helper import/export functions to correctly convert
 * endianness from disk read to native cpu format, and back again.
 */


/* VHDX File Header */


void vhdx_header_le_import(VHDXHeader *h)
{
    assert(h != NULL);

    h->signature = le32_to_cpu(h->signature);
    h->checksum = le32_to_cpu(h->checksum);
    h->sequence_number = le64_to_cpu(h->sequence_number);

    leguid_to_cpus(&h->file_write_guid);
    leguid_to_cpus(&h->data_write_guid);
    leguid_to_cpus(&h->log_guid);

    h->log_version = le16_to_cpu(h->log_version);
    h->version = le16_to_cpu(h->version);
    h->log_length = le32_to_cpu(h->log_length);
    h->log_offset = le64_to_cpu(h->log_offset);
}

void vhdx_header_le_export(VHDXHeader *orig_h, VHDXHeader *new_h)
{
    assert(orig_h != NULL);
    assert(new_h != NULL);

    new_h->signature       = cpu_to_le32(orig_h->signature);
    new_h->checksum        = cpu_to_le32(orig_h->checksum);
    new_h->sequence_number = cpu_to_le64(orig_h->sequence_number);

    new_h->file_write_guid = orig_h->file_write_guid;
    new_h->data_write_guid = orig_h->data_write_guid;
    new_h->log_guid        = orig_h->log_guid;

    cpu_to_leguids(&new_h->file_write_guid);
    cpu_to_leguids(&new_h->data_write_guid);
    cpu_to_leguids(&new_h->log_guid);

    new_h->log_version     = cpu_to_le16(orig_h->log_version);
    new_h->version         = cpu_to_le16(orig_h->version);
    new_h->log_length      = cpu_to_le32(orig_h->log_length);
    new_h->log_offset      = cpu_to_le64(orig_h->log_offset);
}


/* VHDX Log Headers */


void vhdx_log_desc_le_import(VHDXLogDescriptor *d)
{
    assert(d != NULL);

    d->signature = le32_to_cpu(d->signature);
    d->file_offset = le64_to_cpu(d->file_offset);
    d->sequence_number = le64_to_cpu(d->sequence_number);
}

void vhdx_log_desc_le_export(VHDXLogDescriptor *d)
{
    assert(d != NULL);

    d->signature = cpu_to_le32(d->signature);
    d->trailing_bytes = cpu_to_le32(d->trailing_bytes);
    d->leading_bytes = cpu_to_le64(d->leading_bytes);
    d->file_offset = cpu_to_le64(d->file_offset);
    d->sequence_number = cpu_to_le64(d->sequence_number);
}

void vhdx_log_data_le_import(VHDXLogDataSector *d)
{
    assert(d != NULL);

    d->data_signature = le32_to_cpu(d->data_signature);
    d->sequence_high = le32_to_cpu(d->sequence_high);
    d->sequence_low = le32_to_cpu(d->sequence_low);
}

void vhdx_log_data_le_export(VHDXLogDataSector *d)
{
    assert(d != NULL);

    d->data_signature = cpu_to_le32(d->data_signature);
    d->sequence_high = cpu_to_le32(d->sequence_high);
    d->sequence_low = cpu_to_le32(d->sequence_low);
}

void vhdx_log_entry_hdr_le_import(VHDXLogEntryHeader *hdr)
{
    assert(hdr != NULL);

    hdr->signature = le32_to_cpu(hdr->signature);
    hdr->checksum = le32_to_cpu(hdr->checksum);
    hdr->entry_length = le32_to_cpu(hdr->entry_length);
    hdr->tail = le32_to_cpu(hdr->tail);
    hdr->sequence_number = le64_to_cpu(hdr->sequence_number);
    hdr->descriptor_count = le32_to_cpu(hdr->descriptor_count);
    leguid_to_cpus(&hdr->log_guid);
    hdr->flushed_file_offset = le64_to_cpu(hdr->flushed_file_offset);
    hdr->last_file_offset = le64_to_cpu(hdr->last_file_offset);
}

void vhdx_log_entry_hdr_le_export(VHDXLogEntryHeader *hdr)
{
    assert(hdr != NULL);

    hdr->signature = cpu_to_le32(hdr->signature);
    hdr->checksum = cpu_to_le32(hdr->checksum);
    hdr->entry_length = cpu_to_le32(hdr->entry_length);
    hdr->tail = cpu_to_le32(hdr->tail);
    hdr->sequence_number = cpu_to_le64(hdr->sequence_number);
    hdr->descriptor_count = cpu_to_le32(hdr->descriptor_count);
    cpu_to_leguids(&hdr->log_guid);
    hdr->flushed_file_offset = cpu_to_le64(hdr->flushed_file_offset);
    hdr->last_file_offset = cpu_to_le64(hdr->last_file_offset);
}


/* Region table entries */
void vhdx_region_header_le_import(VHDXRegionTableHeader *hdr)
{
    assert(hdr != NULL);

    hdr->signature = le32_to_cpu(hdr->signature);
    hdr->checksum = le32_to_cpu(hdr->checksum);
    hdr->entry_count = le32_to_cpu(hdr->entry_count);
}

void vhdx_region_header_le_export(VHDXRegionTableHeader *hdr)
{
    assert(hdr != NULL);

    hdr->signature = cpu_to_le32(hdr->signature);
    hdr->checksum = cpu_to_le32(hdr->checksum);
    hdr->entry_count = cpu_to_le32(hdr->entry_count);
}

void vhdx_region_entry_le_import(VHDXRegionTableEntry *e)
{
    assert(e != NULL);

    leguid_to_cpus(&e->guid);
    e->file_offset = le64_to_cpu(e->file_offset);
    e->length = le32_to_cpu(e->length);
    e->data_bits = le32_to_cpu(e->data_bits);
}

void vhdx_region_entry_le_export(VHDXRegionTableEntry *e)
{
    assert(e != NULL);

    cpu_to_leguids(&e->guid);
    e->file_offset = cpu_to_le64(e->file_offset);
    e->length = cpu_to_le32(e->length);
    e->data_bits = cpu_to_le32(e->data_bits);
}


/* Metadata headers & table */
void vhdx_metadata_header_le_import(VHDXMetadataTableHeader *hdr)
{
    assert(hdr != NULL);

    hdr->signature = le64_to_cpu(hdr->signature);
    hdr->entry_count = le16_to_cpu(hdr->entry_count);
}

void vhdx_metadata_header_le_export(VHDXMetadataTableHeader *hdr)
{
    assert(hdr != NULL);

    hdr->signature = cpu_to_le64(hdr->signature);
    hdr->entry_count = cpu_to_le16(hdr->entry_count);
}

void vhdx_metadata_entry_le_import(VHDXMetadataTableEntry *e)
{
    assert(e != NULL);

    leguid_to_cpus(&e->item_id);
    e->offset = le32_to_cpu(e->offset);
    e->length = le32_to_cpu(e->length);
    e->data_bits = le32_to_cpu(e->data_bits);
}
void vhdx_metadata_entry_le_export(VHDXMetadataTableEntry *e)
{
    assert(e != NULL);

    cpu_to_leguids(&e->item_id);
    e->offset = cpu_to_le32(e->offset);
    e->length = cpu_to_le32(e->length);
    e->data_bits = cpu_to_le32(e->data_bits);
}