Files
Aaru.Server/DiscImageChef.DiscImages/QCOW.cs

651 lines
22 KiB
C#

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename : QCOW.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Disc image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Manages QEMU Copy-On-Write disk images.
//
// --[ License ] --------------------------------------------------------------
//
// This library 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.
//
// This library 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 this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2017 Natalia Portillo
// ****************************************************************************/
using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using DiscImageChef.CommonTypes;
using DiscImageChef.Console;
using DiscImageChef.Filters;
using SharpCompress.Compressors;
using SharpCompress.Compressors.Deflate;
namespace DiscImageChef.ImagePlugins
{
class QCOW : ImagePlugin
{
#region Internal constants
/// <summary>
/// Magic number: 'Q', 'F', 'I', 0xFB
/// </summary>
const uint QCowMagic = 0x514649FB;
const uint QCowVersion = 1;
const uint QCowEncryptionNone = 0;
const uint QCowEncryptionAES = 1;
const ulong QCowCompressed = 0x8000000000000000;
const int MaxCacheSize = 16777216;
#endregion
#region Internal Structures
/// <summary>
/// QCOW header, big-endian
/// </summary>
[StructLayout(LayoutKind.Sequential, Pack = 1)]
struct QCowHeader
{
/// <summary>
/// <see cref="QCowMagic"/>
/// </summary>
public uint magic;
/// <summary>
/// Must be 1
/// </summary>
public uint version;
/// <summary>
/// Offset inside file to string containing backing file
/// </summary>
public ulong backing_file_offset;
/// <summary>
/// Size of <see cref="backing_file_offset"/>
/// </summary>
public uint backing_file_size;
/// <summary>
/// Modification time
/// </summary>
public uint mtime;
/// <summary>
/// Size in bytes
/// </summary>
public ulong size;
/// <summary>
/// Cluster bits
/// </summary>
public byte cluster_bits;
/// <summary>
/// L2 table bits
/// </summary>
public byte l2_bits;
/// <summary>
/// Padding
/// </summary>
public ushort padding;
/// <summary>
/// Encryption method
/// </summary>
public uint crypt_method;
/// <summary>
/// Offset to L1 table
/// </summary>
public ulong l1_table_offset;
}
#endregion
QCowHeader qHdr;
int clusterSize;
int clusterSectors;
uint l1Size;
int l2Size;
ulong[] l1Table;
ulong l1Mask;
int l1Shift;
ulong l2Mask;
ulong sectorMask;
Dictionary<ulong, byte[]> sectorCache;
Dictionary<ulong, byte[]> clusterCache;
Dictionary<ulong, ulong[]> l2TableCache;
int maxCachedSectors = MaxCacheSize / 512;
int maxL2TableCache;
int maxClusterCache;
Stream imageStream;
public QCOW()
{
Name = "QEMU Copy-On-Write disk image";
PluginUUID = new Guid("A5C35765-9FE2-469D-BBBF-ACDEBDB7B954");
ImageInfo = new ImageInfo();
ImageInfo.readableSectorTags = new List<SectorTagType>();
ImageInfo.readableMediaTags = new List<MediaTagType>();
ImageInfo.imageHasPartitions = false;
ImageInfo.imageHasSessions = false;
ImageInfo.imageVersion = "1";
ImageInfo.imageApplication = "QEMU";
ImageInfo.imageApplicationVersion = null;
ImageInfo.imageCreator = null;
ImageInfo.imageComments = null;
ImageInfo.mediaManufacturer = null;
ImageInfo.mediaModel = null;
ImageInfo.mediaSerialNumber = null;
ImageInfo.mediaBarcode = null;
ImageInfo.mediaPartNumber = null;
ImageInfo.mediaSequence = 0;
ImageInfo.lastMediaSequence = 0;
ImageInfo.driveManufacturer = null;
ImageInfo.driveModel = null;
ImageInfo.driveSerialNumber = null;
ImageInfo.driveFirmwareRevision = null;
}
public override bool IdentifyImage(Filter imageFilter)
{
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
if(stream.Length < 512)
return false;
byte[] qHdr_b = new byte[48];
stream.Read(qHdr_b, 0, 48);
qHdr = BigEndianMarshal.ByteArrayToStructureBigEndian<QCowHeader>(qHdr_b);
return qHdr.magic == QCowMagic && qHdr.version == QCowVersion;
}
public override bool OpenImage(Filter imageFilter)
{
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
if(stream.Length < 512)
return false;
byte[] qHdr_b = new byte[48];
stream.Read(qHdr_b, 0, 48);
qHdr = BigEndianMarshal.ByteArrayToStructureBigEndian<QCowHeader>(qHdr_b);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.magic = 0x{0:X8}", qHdr.magic);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.version = {0}", qHdr.version);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.backing_file_offset = {0}", qHdr.backing_file_offset);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.backing_file_size = {0}", qHdr.backing_file_size);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.mtime = {0}", qHdr.mtime);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.size = {0}", qHdr.size);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.cluster_bits = {0}", qHdr.cluster_bits);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l2_bits = {0}", qHdr.l2_bits);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.padding = {0}", qHdr.padding);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.crypt_method = {0}", qHdr.crypt_method);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l1_table_offset = {0}", qHdr.l1_table_offset);
if(qHdr.size <= 1)
throw new ArgumentOutOfRangeException(nameof(qHdr.size), "Image size is too small");
if(qHdr.cluster_bits < 9 || qHdr.cluster_bits > 16)
throw new ArgumentOutOfRangeException(nameof(qHdr.cluster_bits), "Cluster size must be between 512 bytes and 64 Kbytes");
if(qHdr.l2_bits < 9 - 3 || qHdr.l2_bits > 16 - 3)
throw new ArgumentOutOfRangeException(nameof(qHdr.l2_bits), "L2 size must be between 512 bytes and 64 Kbytes");
if(qHdr.crypt_method > QCowEncryptionAES)
throw new ArgumentOutOfRangeException(nameof(qHdr.crypt_method), "Invalid encryption method");
if(qHdr.crypt_method > QCowEncryptionNone)
throw new NotImplementedException("AES encrypted images not yet supported");
if(qHdr.backing_file_offset != 0)
throw new NotImplementedException("Differencing images not yet supported");
int shift = qHdr.cluster_bits + qHdr.l2_bits;
if(qHdr.size > ulong.MaxValue - (ulong)(1 << shift))
throw new ArgumentOutOfRangeException(nameof(qHdr.size), "Image is too large");
clusterSize = 1 << qHdr.cluster_bits;
clusterSectors = 1 << (qHdr.cluster_bits - 9);
l1Size = (uint)((qHdr.size + (ulong)(1 << shift) - 1) >> shift);
l2Size = 1 << qHdr.l2_bits;
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.clusterSize = {0}", clusterSize);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.clusterSectors = {0}", clusterSectors);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l1Size = {0}", l1Size);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l2Size = {0}", l2Size);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.sectors = {0}", ImageInfo.sectors);
BigEndianBitConverter.IsLittleEndian = BitConverter.IsLittleEndian;
byte[] l1Table_b = new byte[l1Size * 8];
stream.Seek((long)qHdr.l1_table_offset, SeekOrigin.Begin);
stream.Read(l1Table_b, 0, (int)l1Size * 8);
l1Table = new ulong[l1Size];
DicConsole.DebugWriteLine("QCOW plugin", "Reading L1 table");
for(long i = 0; i < l1Table.LongLength; i++)
l1Table[i] = BigEndianBitConverter.ToUInt64(l1Table_b, (int)(i * 8));
l1Mask = 0;
int c = 0;
l1Shift = qHdr.l2_bits + qHdr.cluster_bits;
for(int i = 0; i < 64; i++)
{
l1Mask <<= 1;
if(c < 64 - l1Shift)
{
l1Mask += 1;
c++;
}
}
l2Mask = 0;
for(int i = 0; i < qHdr.l2_bits; i++)
l2Mask = (l2Mask << 1) + 1;
l2Mask <<= qHdr.cluster_bits;
sectorMask = 0;
for(int i = 0; i < qHdr.cluster_bits; i++)
sectorMask = (sectorMask << 1) + 1;
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l1Mask = {0:X}", l1Mask);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l1Shift = {0}", l1Shift);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.l2Mask = {0:X}", l2Mask);
DicConsole.DebugWriteLine("QCOW plugin", "qHdr.sectorMask = {0:X}", sectorMask);
maxL2TableCache = MaxCacheSize / (l2Size * 8);
maxClusterCache = MaxCacheSize / clusterSize;
imageStream = stream;
sectorCache = new Dictionary<ulong, byte[]>();
l2TableCache = new Dictionary<ulong, ulong[]>();
clusterCache = new Dictionary<ulong, byte[]>();
ImageInfo.imageCreationTime = imageFilter.GetCreationTime();
if(qHdr.mtime > 0)
ImageInfo.imageLastModificationTime = DateHandlers.UNIXUnsignedToDateTime(qHdr.mtime);
else
ImageInfo.imageLastModificationTime = imageFilter.GetLastWriteTime();
ImageInfo.imageName = Path.GetFileNameWithoutExtension(imageFilter.GetFilename());
ImageInfo.sectors = qHdr.size / 512;
ImageInfo.sectorSize = 512;
ImageInfo.xmlMediaType = XmlMediaType.BlockMedia;
ImageInfo.mediaType = MediaType.GENERIC_HDD;
ImageInfo.imageSize = qHdr.size;
return true;
}
public override byte[] ReadSector(ulong sectorAddress)
{
if(sectorAddress > ImageInfo.sectors - 1)
throw new ArgumentOutOfRangeException(nameof(sectorAddress), string.Format("Sector address {0} not found", sectorAddress));
byte[] sector;
// Check cache
if(sectorCache.TryGetValue(sectorAddress, out sector))
return sector;
ulong byteAddress = sectorAddress * 512;
ulong l1Off = (byteAddress & l1Mask) >> l1Shift;
if((long)l1Off >= l1Table.LongLength)
throw new ArgumentOutOfRangeException(nameof(l1Off), string.Format("Trying to read past L1 table, position {0} of a max {1}", l1Off, l1Table.LongLength));
// TODO: Implement differential images
if(l1Table[l1Off] == 0)
return new byte[512];
ulong[] l2Table;
if(!l2TableCache.TryGetValue(l1Off, out l2Table))
{
l2Table = new ulong[l2Size];
imageStream.Seek((long)l1Table[l1Off], SeekOrigin.Begin);
byte[] l2Table_b = new byte[l2Size * 8];
imageStream.Read(l2Table_b, 0, l2Size * 8);
DicConsole.DebugWriteLine("QCOW plugin", "Reading L2 table #{0}", l1Off);
for(long i = 0; i < l2Table.LongLength; i++)
l2Table[i] = BigEndianBitConverter.ToUInt64(l2Table_b, (int)(i * 8));
if(l2TableCache.Count >= maxL2TableCache)
l2TableCache.Clear();
l2TableCache.Add(l1Off, l2Table);
}
ulong l2Off = (byteAddress & l2Mask) >> qHdr.cluster_bits;
ulong offset = l2Table[l2Off];
sector = new byte[512];
if(offset != 0)
{
byte[] cluster;
if(!clusterCache.TryGetValue(offset, out cluster))
{
if((offset & QCowCompressed) == QCowCompressed)
{
ulong compSizeMask = 0;
ulong offMask = 0;
compSizeMask = (ulong)(1 << qHdr.cluster_bits) - 1;
compSizeMask <<= 63 - qHdr.cluster_bits;
offMask = (~compSizeMask) ^ QCowCompressed;
ulong realOff = offset & offMask;
ulong compSize = (offset & compSizeMask) >> (63 - qHdr.cluster_bits);
byte[] zCluster = new byte[compSize];
imageStream.Seek((long)realOff, SeekOrigin.Begin);
imageStream.Read(zCluster, 0, (int)compSize);
DeflateStream zStream = new DeflateStream(new MemoryStream(zCluster), CompressionMode.Decompress);
cluster = new byte[clusterSize];
int read = zStream.Read(cluster, 0, clusterSize);
if(read != clusterSize)
throw new IOException(string.Format("Unable to decompress cluster, expected {0} bytes got {1}", clusterSize, read));
}
else
{
cluster = new byte[clusterSize];
imageStream.Seek((long)offset, SeekOrigin.Begin);
imageStream.Read(cluster, 0, clusterSize);
}
if(clusterCache.Count >= maxClusterCache)
clusterCache.Clear();
clusterCache.Add(offset, cluster);
}
Array.Copy(cluster, (int)(byteAddress & sectorMask), sector, 0, 512);
}
if(sectorCache.Count >= maxCachedSectors)
sectorCache.Clear();
sectorCache.Add(sectorAddress, sector);
return sector;
}
public override byte[] ReadSectors(ulong sectorAddress, uint length)
{
if(sectorAddress > ImageInfo.sectors - 1)
throw new ArgumentOutOfRangeException(nameof(sectorAddress), string.Format("Sector address {0} not found", sectorAddress));
if(sectorAddress + length > ImageInfo.sectors)
throw new ArgumentOutOfRangeException(nameof(length), "Requested more sectors than available");
MemoryStream ms = new MemoryStream();
for(uint i = 0; i < length; i++)
{
byte[] sector = ReadSector(sectorAddress + i);
ms.Write(sector, 0, sector.Length);
}
return ms.ToArray();
}
public override bool ImageHasPartitions()
{
return false;
}
public override ulong GetImageSize()
{
return ImageInfo.imageSize;
}
public override ulong GetSectors()
{
return ImageInfo.sectors;
}
public override uint GetSectorSize()
{
return ImageInfo.sectorSize;
}
public override string GetImageFormat()
{
return "QEMU Copy-On-Write";
}
public override string GetImageVersion()
{
return ImageInfo.imageVersion;
}
public override string GetImageApplication()
{
return ImageInfo.imageApplication;
}
public override string GetImageApplicationVersion()
{
return ImageInfo.imageApplicationVersion;
}
public override string GetImageCreator()
{
return ImageInfo.imageCreator;
}
public override DateTime GetImageCreationTime()
{
return ImageInfo.imageCreationTime;
}
public override DateTime GetImageLastModificationTime()
{
return ImageInfo.imageLastModificationTime;
}
public override string GetImageName()
{
return ImageInfo.imageName;
}
public override string GetImageComments()
{
return ImageInfo.imageComments;
}
public override MediaType GetMediaType()
{
return ImageInfo.mediaType;
}
#region Unsupported features
public override byte[] ReadSectorTag(ulong sectorAddress, SectorTagType tag)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorsTag(ulong sectorAddress, uint length, SectorTagType tag)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadDiskTag(MediaTagType tag)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSector(ulong sectorAddress, uint track)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorTag(ulong sectorAddress, uint track, SectorTagType tag)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectors(ulong sectorAddress, uint length, uint track)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorsTag(ulong sectorAddress, uint length, uint track, SectorTagType tag)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorLong(ulong sectorAddress)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorLong(ulong sectorAddress, uint track)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorsLong(ulong sectorAddress, uint length)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override byte[] ReadSectorsLong(ulong sectorAddress, uint length, uint track)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override string GetMediaManufacturer()
{
return null;
}
public override string GetMediaModel()
{
return null;
}
public override string GetMediaSerialNumber()
{
return null;
}
public override string GetMediaBarcode()
{
return null;
}
public override string GetMediaPartNumber()
{
return null;
}
public override int GetMediaSequence()
{
return 0;
}
public override int GetLastDiskSequence()
{
return 0;
}
public override string GetDriveManufacturer()
{
return null;
}
public override string GetDriveModel()
{
return null;
}
public override string GetDriveSerialNumber()
{
return null;
}
public override List<Partition> GetPartitions()
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override List<Track> GetTracks()
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override List<Track> GetSessionTracks(Session session)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override List<Track> GetSessionTracks(ushort session)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override List<Session> GetSessions()
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override bool? VerifySector(ulong sectorAddress)
{
return null;
}
public override bool? VerifySector(ulong sectorAddress, uint track)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override bool? VerifySectors(ulong sectorAddress, uint length, out List<ulong> FailingLBAs, out List<ulong> UnknownLBAs)
{
FailingLBAs = new List<ulong>();
UnknownLBAs = new List<ulong>();
for(ulong i = 0; i < ImageInfo.sectors; i++)
UnknownLBAs.Add(i);
return null;
}
public override bool? VerifySectors(ulong sectorAddress, uint length, uint track, out List<ulong> FailingLBAs, out List<ulong> UnknownLBAs)
{
throw new FeatureUnsupportedImageException("Feature not supported by image format");
}
public override bool? VerifyMediaImage()
{
return null;
}
#endregion
}
}