Files
Aaru/Aaru.Images/WCDiskImage/Read.cs

345 lines
13 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Read.cs
// Author(s) : Michael Drüing <michael@drueing.de>
//
// Component : Disk image plugins.
//
// --[ Description ] ----------------------------------------------------------
//
// Reads d2f 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 © 2018-2025 Michael Drüing
// Copyright © 2011-2025 Natalia Portillo
// ****************************************************************************/
using System;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Text;
using Aaru.Checksums;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;
using Aaru.Logging;
namespace Aaru.Images;
[SuppressMessage("ReSharper", "UnusedType.Global")]
public sealed partial class WCDiskImage
{
#region IMediaImage Members
/// <inheritdoc />
public ErrorNumber Open(IFilter imageFilter)
{
string comments = string.Empty;
Stream stream = imageFilter.GetDataForkStream();
stream.Seek(0, SeekOrigin.Begin);
var header = new byte[32];
stream.EnsureRead(header, 0, 32);
FileHeader fheader = Marshal.ByteArrayToStructureLittleEndian<FileHeader>(header);
AaruLogging.Debug(MODULE_NAME,
Localization.Detected_WC_DISK_IMAGE_with_0_heads_1_tracks_and_2_sectors_per_track,
fheader.heads,
fheader.cylinders,
fheader.sectorsPerTrack);
_imageInfo.Cylinders = fheader.cylinders;
_imageInfo.SectorsPerTrack = fheader.sectorsPerTrack;
_imageInfo.SectorSize = 512; // only 512 bytes per sector supported
_imageInfo.Heads = fheader.heads;
_imageInfo.Sectors = _imageInfo.Heads * _imageInfo.Cylinders * _imageInfo.SectorsPerTrack;
_imageInfo.ImageSize = _imageInfo.Sectors * _imageInfo.SectorSize;
_imageInfo.MetadataMediaType = MetadataMediaType.BlockMedia;
_imageInfo.CreationTime = imageFilter.CreationTime;
_imageInfo.LastModificationTime = imageFilter.LastWriteTime;
_imageInfo.MediaTitle = Path.GetFileNameWithoutExtension(imageFilter.Filename);
_imageInfo.MediaType = Geometry.GetMediaType(((ushort)_imageInfo.Cylinders, (byte)_imageInfo.Heads,
(ushort)_imageInfo.SectorsPerTrack, 512, MediaEncoding.MFM,
false));
/* buffer the entire disk in memory */
for(var cyl = 0; cyl < _imageInfo.Cylinders; cyl++)
{
for(var head = 0; head < _imageInfo.Heads; head++)
{
ErrorNumber errno = ReadTrack(stream, cyl, head);
if(errno != ErrorNumber.NoError) return errno;
}
}
/* if there are extra tracks, read them as well */
if(fheader.extraTracks[0] == 1)
{
AaruLogging.Debug(MODULE_NAME, Localization.Extra_track_1_head_0_present_reading);
ReadTrack(stream, (int)_imageInfo.Cylinders, 0);
}
if(fheader.extraTracks[1] == 1)
{
AaruLogging.Debug(MODULE_NAME, Localization.Extra_track_1_head_1_present_reading);
ReadTrack(stream, (int)_imageInfo.Cylinders, 1);
}
if(fheader.extraTracks[2] == 1)
{
AaruLogging.Debug(MODULE_NAME, Localization.Extra_track_2_head_0_present_reading);
ReadTrack(stream, (int)_imageInfo.Cylinders + 1, 0);
}
if(fheader.extraTracks[3] == 1)
{
AaruLogging.Debug(MODULE_NAME, Localization.Extra_track_2_head_1_present_reading);
ReadTrack(stream, (int)_imageInfo.Cylinders + 1, 1);
}
/* adjust number of cylinders */
if(fheader.extraTracks[0] == 1 || fheader.extraTracks[1] == 1) _imageInfo.Cylinders++;
if(fheader.extraTracks[2] == 1 || fheader.extraTracks[3] == 1) _imageInfo.Cylinders++;
/* read the comment and directory data if present */
if(fheader.extraFlags.HasFlag(ExtraFlag.Comment))
{
AaruLogging.Debug(MODULE_NAME, Localization.Comment_present_reading);
var sheaderBuffer = new byte[6];
stream.EnsureRead(sheaderBuffer, 0, 6);
SectorHeader sheader = Marshal.ByteArrayToStructureLittleEndian<SectorHeader>(sheaderBuffer);
if(sheader.flag != SectorFlag.Comment)
{
AaruLogging.Error(string.Format(Localization.Invalid_sector_type_0_encountered,
sheader.flag.ToString()));
return ErrorNumber.InvalidArgument;
}
var comm = new byte[sheader.crc];
stream.EnsureRead(comm, 0, sheader.crc);
comments += Encoding.ASCII.GetString(comm) + Environment.NewLine;
}
if(fheader.extraFlags.HasFlag(ExtraFlag.Directory))
{
AaruLogging.Debug(MODULE_NAME, Localization.Directory_listing_present_reading);
var sheaderBuffer = new byte[6];
stream.EnsureRead(sheaderBuffer, 0, 6);
SectorHeader sheader = Marshal.ByteArrayToStructureLittleEndian<SectorHeader>(sheaderBuffer);
if(sheader.flag != SectorFlag.Directory)
{
AaruLogging.Error(string.Format(Localization.Invalid_sector_type_0_encountered,
sheader.flag.ToString()));
return ErrorNumber.InvalidArgument;
}
var dir = new byte[sheader.crc];
stream.EnsureRead(dir, 0, sheader.crc);
comments += Encoding.ASCII.GetString(dir);
}
if(comments.Length > 0) _imageInfo.Comments = comments;
// save some variables for later use
_fileHeader = fheader;
_wcImageFilter = imageFilter;
return ErrorNumber.InvalidArgument;
}
/// <inheritdoc />
public ErrorNumber ReadSector(ulong sectorAddress, bool negative, out byte[] buffer, out SectorStatus sectorStatus)
{
sectorStatus = SectorStatus.NotDumped;
buffer = null;
if(negative) return ErrorNumber.NotSupported;
int sectorNumber = (int)(sectorAddress % _imageInfo.SectorsPerTrack) + 1;
var trackNumber = (int)(sectorAddress / _imageInfo.SectorsPerTrack);
int headNumber = _imageInfo.Heads > 1 ? trackNumber % 2 : 0;
int cylinderNumber = _imageInfo.Heads > 1 ? trackNumber / 2 : trackNumber;
if(_badSectors[(cylinderNumber, headNumber, sectorNumber)])
{
AaruLogging.Debug(MODULE_NAME,
Localization.reading_bad_sector_0_1_2_3,
sectorAddress,
cylinderNumber,
headNumber,
sectorNumber);
/* if we have sector data, return that */
if(_sectorCache.ContainsKey((cylinderNumber, headNumber, sectorNumber)))
{
buffer = _sectorCache[(cylinderNumber, headNumber, sectorNumber)];
sectorStatus = SectorStatus.Errored;
return ErrorNumber.NoError;
}
/* otherwise, return an empty sector */
buffer = new byte[512];
sectorStatus = SectorStatus.Errored;
return ErrorNumber.NoError;
}
sectorStatus = SectorStatus.Dumped;
buffer = _sectorCache[(cylinderNumber, headNumber, sectorNumber)];
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber ReadSectors(ulong sectorAddress, bool negative, uint length, out byte[] buffer,
out SectorStatus[] sectorStatus)
{
buffer = null;
sectorStatus = null;
if(negative) return ErrorNumber.NotSupported;
if(sectorAddress > _imageInfo.Sectors - 1) return ErrorNumber.OutOfRange;
if(sectorAddress + length > _imageInfo.Sectors) return ErrorNumber.OutOfRange;
var ms = new MemoryStream();
sectorStatus = new SectorStatus[length];
for(uint i = 0; i < length; i++)
{
ErrorNumber errno = ReadSector(sectorAddress + i, false, out byte[] sector, out SectorStatus status);
if(errno != ErrorNumber.NoError) return errno;
ms.Write(sector, 0, sector.Length);
sectorStatus[i] = status;
}
buffer = ms.ToArray();
return ErrorNumber.NoError;
}
#endregion
/// <summary>Read a whole track and cache it</summary>
/// <param name="stream">The stream to read from</param>
/// <param name="cyl">The cylinder number of the track being read.</param>
/// <param name="head">The head number of the track being read.</param>
ErrorNumber ReadTrack(Stream stream, int cyl, int head)
{
for(var sect = 1; sect < _imageInfo.SectorsPerTrack + 1; sect++)
{
/* read the sector header */
var sheaderBuffer = new byte[6];
stream.EnsureRead(sheaderBuffer, 0, 6);
SectorHeader sheader = Marshal.ByteArrayToStructureLittleEndian<SectorHeader>(sheaderBuffer);
/* validate the sector header */
if(sheader.cylinder != cyl || sheader.head != head || sheader.sector != sect)
{
AaruLogging.Error(string.Format(Localization
.Unexpected_sector_encountered_Found_CHS_0_1_2_but_expected_3_4_5,
sheader.cylinder,
sheader.head,
sheader.sector,
cyl,
head,
sect));
return ErrorNumber.InvalidArgument;
}
var sectorData = new byte[512];
/* read the sector data */
switch(sheader.flag)
{
case SectorFlag.Normal: /* read a normal sector and store it in cache */
stream.EnsureRead(sectorData, 0, 512);
_sectorCache[(cyl, head, sect)] = sectorData;
CRC16IbmContext.Data(sectorData, 512, out byte[] crc);
var calculatedCRC = (short)(256 * crc[0] | crc[1]);
/*
AaruLogging.DebugWriteLine(MODULE_NAME, "CHS {0},{1},{2}: Regular sector, stored CRC=0x{3:x4}, calculated CRC=0x{4:x4}",
cyl, head, sect, sheader.crc, 256 * crc[0] + crc[1]);
*/
_badSectors[(cyl, head, sect)] = sheader.crc != calculatedCRC;
if(calculatedCRC != sheader.crc)
{
AaruLogging.Debug(MODULE_NAME,
Localization.CHS_0_1_2_CRC_mismatch_stored_CRC_3_X4_calculated_CRC_4_X4,
cyl,
head,
sect,
sheader.crc,
calculatedCRC);
}
break;
case SectorFlag.BadSector:
/*
AaruLogging.DebugWriteLine(MODULE_NAME, "CHS {0},{1},{2}: Bad sector",
cyl, head, sect);
*/
_badSectors[(cyl, head, sect)] = true;
break;
case SectorFlag.RepeatByte:
/*
AaruLogging.DebugWriteLine(MODULE_NAME, "CHS {0},{1},{2}: RepeatByte sector, fill byte 0x{0:x2}",
cyl, head, sect, sheader.crc & 0xff);
*/
for(var i = 0; i < 512; i++) sectorData[i] = (byte)(sheader.crc & 0xff);
_sectorCache[(cyl, head, sect)] = sectorData;
_badSectors[(cyl, head, sect)] = false;
break;
default:
AaruLogging.Error(string.Format(Localization.Invalid_sector_type_0_encountered,
sheader.flag.ToString()));
return ErrorNumber.InvalidArgument;
}
}
return ErrorNumber.NoError;
}
}