Files
Aaru/Aaru.Filesystems/UCSDPascal/Super.cs

341 lines
13 KiB
C#

// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Super.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : U.C.S.D. Pascal filesystem plugin.
//
// --[ Description ] ----------------------------------------------------------
//
// Handles mounting and umounting the U.C.S.D. Pascal filesystem.
//
// --[ 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 © 2011-2026 Natalia Portillo
// ****************************************************************************/
using System.Collections.Generic;
using Aaru.CommonTypes.AaruMetadata;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Interfaces;
using Aaru.Helpers;
using Aaru.Logging;
using Claunia.Encoding;
using Encoding = System.Text.Encoding;
using FileSystemInfo = Aaru.CommonTypes.Structs.FileSystemInfo;
using Marshal = Aaru.Helpers.Marshal;
using Partition = Aaru.CommonTypes.Partition;
namespace Aaru.Filesystems;
// Information from Call-A.P.P.L.E. Pascal Disk Directory Structure
public sealed partial class PascalPlugin
{
#region IReadOnlyFilesystem Members
/// <inheritdoc />
public ErrorNumber Mount(IMediaImage imagePlugin, Partition partition, Encoding encoding,
Dictionary<string, string> options, string @namespace)
{
_device = imagePlugin;
_encoding = encoding ?? new Apple2();
options ??= GetDefaultOptions();
if(options.TryGetValue("debug", out string debugString)) bool.TryParse(debugString, out _debug);
if(options.TryGetValue("decode_text", out string decodeTextString))
bool.TryParse(decodeTextString, out _decodeText);
if(_device.Info.Sectors < 3) return ErrorNumber.InvalidArgument;
_multiplier = (uint)(imagePlugin.Info.SectorSize == 256 ? 2 : 1);
// Blocks 0 and 1 are boot code
ErrorNumber errno = _device.ReadSectors(_multiplier * 2, false, _multiplier, out _catalogBlocks, out _);
if(errno != ErrorNumber.NoError) return errno;
// Try little endian first (Apple II), then big endian (other platforms)
_bigEndian = false;
PascalVolumeEntry volEntry = Marshal.ByteArrayToStructureLittleEndian<PascalVolumeEntry>(_catalogBlocks);
if(!IsValidVolumeEntry(volEntry))
{
_bigEndian = true;
volEntry = Marshal.ByteArrayToStructureBigEndian<PascalVolumeEntry>(_catalogBlocks);
if(!IsValidVolumeEntry(volEntry)) return ErrorNumber.InvalidArgument;
}
_mountedVolEntry = volEntry;
if(_mountedVolEntry.FirstBlock != 0 ||
_mountedVolEntry.LastBlock <= _mountedVolEntry.FirstBlock ||
(ulong)_mountedVolEntry.LastBlock > _device.Info.Sectors / _multiplier - 2 ||
_mountedVolEntry.EntryType != PascalFileKind.Volume && _mountedVolEntry.EntryType != PascalFileKind.Secure ||
_mountedVolEntry.VolumeName[0] > 7 ||
_mountedVolEntry.Blocks < 0 ||
(ulong)_mountedVolEntry.Blocks != _device.Info.Sectors / _multiplier ||
_mountedVolEntry.Files < 0)
return ErrorNumber.InvalidArgument;
errno = _device.ReadSectors(_multiplier * 2,
false,
(uint)(_mountedVolEntry.LastBlock - _mountedVolEntry.FirstBlock - 2) * _multiplier,
out _catalogBlocks,
out _);
if(errno != ErrorNumber.NoError) return errno;
const int entrySize = 26;
int offset = entrySize; // Skip first entry (volume entry)
_fileEntries = [];
while(offset + entrySize <= _catalogBlocks.Length)
{
PascalFileEntry entry = _bigEndian
? Marshal.ByteArrayToStructureBigEndian<PascalFileEntry>(_catalogBlocks,
offset,
entrySize)
: Marshal.ByteArrayToStructureLittleEndian<PascalFileEntry>(_catalogBlocks,
offset,
entrySize);
if(entry.Filename?[0] <= 15 && entry.Filename?[0] > 0) _fileEntries.Add(entry);
offset += entrySize;
}
// Validate filesystem consistency
ValidateFilesystem();
errno = _device.ReadSectors(0, false, 2 * _multiplier, out _bootBlocks, out _);
if(errno != ErrorNumber.NoError) return errno;
Metadata = new FileSystem
{
Bootable = !ArrayHelpers.ArrayIsNullOrEmpty(_bootBlocks),
Clusters = (ulong)_mountedVolEntry.Blocks,
ClusterSize = _device.Info.SectorSize,
Files = (ulong)_mountedVolEntry.Files,
Type = FS_TYPE,
VolumeName = StringHandlers.PascalToString(_mountedVolEntry.VolumeName, _encoding)
};
_mounted = true;
return ErrorNumber.NoError;
}
/// <summary>Checks if a volume entry is valid</summary>
/// <param name="volEntry">Volume entry to validate</param>
/// <returns>True if the volume entry appears valid</returns>
bool IsValidVolumeEntry(PascalVolumeEntry volEntry)
{
// First block is always 0
if(volEntry.FirstBlock != 0) return false;
// Last volume record block must be after first block, and before end of device
if(volEntry.LastBlock <= volEntry.FirstBlock ||
(ulong)volEntry.LastBlock > _device.Info.Sectors / _multiplier - 2)
return false;
// Volume record entry type must be volume or secure
if(volEntry.EntryType != PascalFileKind.Volume && volEntry.EntryType != PascalFileKind.Secure) return false;
// Volume name is max 7 characters
if(volEntry.VolumeName?[0] > 7) return false;
// Volume blocks is equal to volume sectors
if(volEntry.Blocks < 0 || (ulong)volEntry.Blocks != _device.Info.Sectors / _multiplier) return false;
// There can be not less than zero files
return volEntry.Files >= 0;
}
/// <summary>Validates filesystem consistency and logs any issues found</summary>
void ValidateFilesystem()
{
var errorCount = 0;
// Check 1: File count matches volume header
if(_fileEntries.Count != _mountedVolEntry.Files)
{
AaruLogging.Error("File count mismatch: volume header says {0} files, but found {1} directory entries",
_mountedVolEntry.Files,
_fileEntries.Count);
errorCount++;
}
if(_fileEntries.Count == 0)
{
if(errorCount > 0) AaruLogging.Error("Filesystem validation completed with {0} issue(s)", errorCount);
return;
}
// Check 2: Files are in block order
for(var i = 1; i < _fileEntries.Count; i++)
{
if(_fileEntries[i - 1].LastBlock > _fileEntries[i].FirstBlock)
{
AaruLogging.Error("Directory entries not in block order: '{0}' (ends at block {1}) comes before '{2}' (starts at block {3})",
StringHandlers.PascalToString(_fileEntries[i - 1].Filename, _encoding),
_fileEntries[i - 1].LastBlock,
StringHandlers.PascalToString(_fileEntries[i].Filename, _encoding),
_fileEntries[i].FirstBlock);
errorCount++;
break; // Only report once
}
}
// Check 3: No block overlaps - first file must start after directory
int expectedFirstBlock = _mountedVolEntry.LastBlock;
foreach(PascalFileEntry entry in _fileEntries)
{
string fileName = StringHandlers.PascalToString(entry.Filename, _encoding);
// File starts before expected position (overlap with previous file or directory)
if(entry.FirstBlock < expectedFirstBlock)
{
AaruLogging.Error("File '{0}' starts at block {1}, but expected block {2} or later (block overlap detected)",
fileName,
entry.FirstBlock,
expectedFirstBlock);
errorCount++;
}
// File ends before it starts (invalid)
if(entry.LastBlock <= entry.FirstBlock)
{
AaruLogging.Error("File '{0}' has invalid block range: FirstBlock={1}, LastBlock={2}",
fileName,
entry.FirstBlock,
entry.LastBlock);
errorCount++;
continue;
}
// File extends beyond end of volume
if(entry.LastBlock > _mountedVolEntry.Blocks)
{
AaruLogging.Error("File '{0}' extends beyond end of volume: LastBlock={1}, VolumeBlocks={2}",
fileName,
entry.LastBlock,
_mountedVolEntry.Blocks);
errorCount++;
}
// Validate LastBytes field (should be 1-512)
if(entry.LastBytes <= 0 || entry.LastBytes > 512)
{
AaruLogging.Error("File '{0}' has invalid LastBytes value: {1} (expected 1-512)",
fileName,
entry.LastBytes);
errorCount++;
}
// Validate file type
if(entry.EntryType < PascalFileKind.Bad || entry.EntryType > PascalFileKind.Secure)
{
AaruLogging.Error("File '{0}' has invalid file type: {1}", fileName, (int)entry.EntryType);
errorCount++;
}
// Validate filename length
if(entry.Filename[0] == 0 || entry.Filename[0] > 15)
{
AaruLogging.Error("File '{0}' has invalid filename length: {1} (expected 1-15)",
fileName,
entry.Filename[0]);
errorCount++;
}
// Update expected first block for next file
expectedFirstBlock = entry.LastBlock;
}
// Check 4: Last file doesn't extend beyond volume
if(_fileEntries.Count > 0)
{
PascalFileEntry lastEntry = _fileEntries[^1];
if(lastEntry.LastBlock > _mountedVolEntry.Blocks)
{
AaruLogging.Error("Last file '{0}' extends beyond volume: ends at block {1}, volume has {2} blocks",
StringHandlers.PascalToString(lastEntry.Filename, _encoding),
lastEntry.LastBlock,
_mountedVolEntry.Blocks);
errorCount++;
}
}
if(errorCount > 0)
AaruLogging.Error("Filesystem validation completed with {0} issue(s)", errorCount);
else
AaruLogging.Debug(MODULE_NAME, "Filesystem validation passed");
}
/// <inheritdoc />
public ErrorNumber Unmount()
{
_mounted = false;
_fileEntries = null;
return ErrorNumber.NoError;
}
/// <inheritdoc />
public ErrorNumber StatFs(out FileSystemInfo stat)
{
stat = new FileSystemInfo
{
Blocks = (ulong)_mountedVolEntry.Blocks,
FilenameLength = 16,
Files = (ulong)_mountedVolEntry.Files,
FreeBlocks = 0,
PluginId = Id,
Type = FS_TYPE
};
stat.FreeBlocks = (ulong)(_mountedVolEntry.Blocks - (_mountedVolEntry.LastBlock - _mountedVolEntry.FirstBlock));
foreach(PascalFileEntry entry in _fileEntries) stat.FreeBlocks -= (ulong)(entry.LastBlock - entry.FirstBlock);
return ErrorNumber.NoError;
}
#endregion
}