[NTFS] Add support for analyze command

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2026-04-10 21:25:08 +01:00
parent 476ae51494
commit 431b252d94

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// /***************************************************************************
// Aaru Data Preservation Suite
// ----------------------------------------------------------------------------
//
// Filename : Analyze.cs
// Author(s) : Natalia Portillo <claunia@claunia.com>
//
// Component : Microsoft NT File System plugin.
//
// --[ 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;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Aaru.CommonTypes;
using Aaru.CommonTypes.Enums;
using Aaru.CommonTypes.Structs;
namespace Aaru.Filesystems;
/// <inheritdoc />
public sealed partial class NTFS
{
#region IReadOnlyFilesystem Members
/// <inheritdoc />
public ErrorNumber GetFilesWithAffectedSectors(IEnumerable<(ulong Start, ulong End)> sectorExtents,
out List<FileSectorInfo> files,
InitProgressHandler initProgress = null,
UpdateProgressHandler updateProgress = null,
PulseProgressHandler pulseProgress = null,
EndProgressHandler endProgress = null)
{
files = [];
if(!_mounted) return ErrorNumber.AccessDenied;
if(sectorExtents is null) return ErrorNumber.InvalidArgument;
List<(ulong Start, ulong End)> normalizedExtents = NormalizeAnalyzeExtents(sectorExtents);
if(normalizedExtents.Count == 0) return ErrorNumber.NoError;
try
{
initProgress?.Invoke();
return TraverseDirectoryForAffectedSectors("/",
(uint)SystemFileNumber.Root,
normalizedExtents,
files,
updateProgress,
pulseProgress);
}
finally
{
endProgress?.Invoke();
}
}
#endregion
ErrorNumber TraverseDirectoryForAffectedSectors(string path, uint directoryMftRecordNumber,
List<(ulong Start, ulong End)> sectorExtents,
List<FileSectorInfo> files, UpdateProgressHandler updateProgress,
PulseProgressHandler pulseProgress)
{
pulseProgress?.Invoke(path);
Dictionary<string, ulong> directoryEntries;
if(directoryMftRecordNumber == (uint)SystemFileNumber.Root)
directoryEntries = new Dictionary<string, ulong>(_rootDirectoryCache, StringComparer.OrdinalIgnoreCase);
else
{
ErrorNumber errno = ReadDirectoryEntries(directoryMftRecordNumber, out directoryEntries);
if(errno != ErrorNumber.NoError) return errno;
}
KeyValuePair<string, ulong>[] orderedEntries = directoryEntries
.Where(static entry => !string.IsNullOrWhiteSpace(entry.Key))
.OrderBy(static entry => entry.Key,
StringComparer.OrdinalIgnoreCase)
.ToArray();
long maximum = orderedEntries.Length > 0 ? orderedEntries.Length : 1;
for(var i = 0; i < orderedEntries.Length; i++)
{
string entryPath = path == "/" ? "/" + orderedEntries[i].Key : path + "/" + orderedEntries[i].Key;
updateProgress?.Invoke(entryPath, i + 1, maximum);
var childMftRecordNumber = (uint)(orderedEntries[i].Value & 0x0000FFFFFFFFFFFF);
ErrorNumber errno = ReadMftRecord(childMftRecordNumber, out byte[] recordData);
if(errno != ErrorNumber.NoError) return errno;
MftRecord header = ParseMftRecordHeader(recordData);
if(header.magic != NtfsRecordMagic.File || !header.flags.HasFlag(MftRecordFlags.InUse)) continue;
if(header.flags.HasFlag(MftRecordFlags.IsDirectory))
{
errno = TraverseDirectoryForAffectedSectors(entryPath,
childMftRecordNumber,
sectorExtents,
files,
updateProgress,
pulseProgress);
if(errno != ErrorNumber.NoError) return errno;
continue;
}
errno = AddOverlappingFile(entryPath, childMftRecordNumber, recordData, header, sectorExtents, files);
if(errno != ErrorNumber.NoError) return errno;
}
return ErrorNumber.NoError;
}
ErrorNumber AddOverlappingFile(string path, uint mftRecordNumber, byte[] recordData, in MftRecord header,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents, List<FileSectorInfo> files)
{
ErrorNumber errno = FindAllAttributes(recordData, header, mftRecordNumber, out List<FoundAttribute> attrs);
if(errno != ErrorNumber.NoError) return errno;
HashSet<string> processedStreams = new(StringComparer.OrdinalIgnoreCase);
foreach(FoundAttribute attr in attrs)
{
var attrType = (AttributeType)BitConverter.ToUInt32(attr.RecordData, attr.Offset);
if(attrType != AttributeType.Data) continue;
string streamName = GetAttributeName(attr.RecordData, attr.Offset);
string processedName = streamName ?? string.Empty;
if(!processedStreams.Add(processedName)) continue;
errno = AddOverlappingStream(path, mftRecordNumber, streamName, attr, sectorExtents, files);
if(errno != ErrorNumber.NoError) return errno;
}
return ErrorNumber.NoError;
}
ErrorNumber AddOverlappingStream(string path, uint mftRecordNumber, string streamName, in FoundAttribute attr,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents, List<FileSectorInfo> files)
{
byte nonResident = attr.RecordData[attr.Offset + 8];
List<(ulong Start, ulong End)> overlaps;
if(nonResident == 0)
{
var valueLength = BitConverter.ToUInt32(attr.RecordData, attr.Offset + 0x10);
if(valueLength == 0) return ErrorNumber.NoError;
var valueOffset = BitConverter.ToUInt16(attr.RecordData, attr.Offset + 0x14);
int valueStart = attr.Offset + valueOffset;
uint recordNumber = GetResidentRecordNumber(attr.RecordData, mftRecordNumber);
overlaps = FindResidentOverlaps(recordNumber, valueStart, valueLength, sectorExtents);
}
else
{
ErrorNumber errno = AssembleNonResidentRuns(mftRecordNumber,
AttributeType.Data,
streamName,
out List<(long offset, long length)> dataRuns,
out long dataSize,
out _,
out _,
out _);
if(errno != ErrorNumber.NoError) return errno;
if(dataSize <= 0) return ErrorNumber.NoError;
overlaps = FindNonResidentOverlaps(dataRuns, dataSize, sectorExtents);
}
if(overlaps.Count == 0) return ErrorNumber.NoError;
files.Add(new FileSectorInfo
{
Path = path,
Stream = string.IsNullOrWhiteSpace(streamName) ? null : streamName,
Inode = mftRecordNumber,
AffectedSectors = overlaps
});
return ErrorNumber.NoError;
}
uint GetResidentRecordNumber(byte[] recordData, uint fallbackRecordNumber)
{
MftRecord header = ParseMftRecordHeader(recordData);
return header.mft_record_number != 0 ? header.mft_record_number : fallbackRecordNumber;
}
static string GetAttributeName(byte[] recordData, int offset)
{
byte nameLength = recordData[offset + 9];
if(nameLength == 0) return null;
var nameOffset = BitConverter.ToUInt16(recordData, offset + 0x0A);
int nameStart = offset + nameOffset;
int nameBytes = nameLength * 2;
if(nameStart < 0 || nameStart + nameBytes > recordData.Length) return null;
return Encoding.Unicode.GetString(recordData, nameStart, nameBytes);
}
List<(ulong Start, ulong End)> FindResidentOverlaps(uint recordNumber, int valueStart, uint valueLength,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents)
{
List<(ulong Start, ulong End)> overlaps = [];
AddMftByteRangeOverlaps((long)recordNumber * _mftRecordSize + valueStart, valueLength, sectorExtents, overlaps);
return NormalizeAnalyzeExtents(overlaps);
}
void AddMftByteRangeOverlaps(long relativeByteOffset, ulong byteLength,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<(ulong Start, ulong End)> overlaps)
{
if(byteLength == 0) return;
if(_mftDataRuns is { Count: > 0 })
{
var bytesRemaining = (long)byteLength;
long currentOffset = relativeByteOffset;
long runByteStart = 0;
foreach((long clusterOffset, long clusterLength) in _mftDataRuns)
{
long runBytes = clusterLength * _bytesPerCluster;
long runByteEnd = runByteStart + runBytes;
if(runByteEnd <= currentOffset)
{
runByteStart = runByteEnd;
continue;
}
if(bytesRemaining <= 0) break;
long offsetInRun = currentOffset - runByteStart;
long bytesInThisRun = Math.Min(runBytes - offsetInRun, bytesRemaining);
if(bytesInThisRun <= 0)
{
runByteStart = runByteEnd;
continue;
}
if(clusterOffset != 0)
{
long physicalByteOffset = clusterOffset * _bytesPerCluster + offsetInRun;
ulong startSector = _partition.Start + (ulong)(physicalByteOffset / _bytesPerSector);
var offsetInSector = (ulong)(physicalByteOffset % _bytesPerSector);
ulong sectorCount = ((ulong)bytesInThisRun + offsetInSector + _bytesPerSector - 1) /
_bytesPerSector;
if(sectorCount == 0) sectorCount = 1;
AddExtentOverlaps(startSector, startSector + sectorCount - 1, sectorExtents, overlaps);
}
currentOffset += bytesInThisRun;
bytesRemaining -= bytesInThisRun;
runByteStart = runByteEnd;
}
return;
}
long mftStartByte = _bpb.mft_lsn * _bytesPerCluster;
long byteOffset = mftStartByte + relativeByteOffset;
ulong start = _partition.Start + (ulong)(byteOffset / _bytesPerSector);
var byteOffsetInSector = (ulong)(byteOffset % _bytesPerSector);
ulong sectors = (byteLength + byteOffsetInSector + _bytesPerSector - 1) / _bytesPerSector;
if(sectors == 0) sectors = 1;
AddExtentOverlaps(start, start + sectors - 1, sectorExtents, overlaps);
}
List<(ulong Start, ulong End)> FindNonResidentOverlaps(List<(long offset, long length)> dataRuns, long dataSize,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents)
{
List<(ulong Start, ulong End)> overlaps = [];
if(dataSize <= 0 || dataRuns is null || dataRuns.Count == 0) return overlaps;
long remainingBytes = dataSize;
foreach((long clusterOffset, long clusterLength) in dataRuns)
{
if(remainingBytes <= 0) break;
if(clusterLength <= 0) continue;
long runBytes = clusterLength * _bytesPerCluster;
long bytesInRun = Math.Min(runBytes, remainingBytes);
if(bytesInRun <= 0) break;
if(clusterOffset != 0)
{
ulong startSector = _partition.Start + (ulong)clusterOffset * _sectorsPerCluster;
ulong sectorCount = ((ulong)bytesInRun + _bytesPerSector - 1) / _bytesPerSector;
if(sectorCount == 0) sectorCount = 1;
AddExtentOverlaps(startSector, startSector + sectorCount - 1, sectorExtents, overlaps);
}
remainingBytes -= bytesInRun;
}
return NormalizeAnalyzeExtents(overlaps);
}
static void AddExtentOverlaps(ulong startSector, ulong endSector,
IReadOnlyList<(ulong Start, ulong End)> sectorExtents,
List<(ulong Start, ulong End)> overlaps)
{
foreach((ulong Start, ulong End) requestedExtent in sectorExtents)
{
if(requestedExtent.End < startSector || requestedExtent.Start > endSector) continue;
overlaps.Add((Math.Max(startSector, requestedExtent.Start), Math.Min(endSector, requestedExtent.End)));
}
}
static List<(ulong Start, ulong End)> NormalizeAnalyzeExtents(IEnumerable<(ulong Start, ulong End)> extents)
{
var orderedExtents = extents.Where(static extent => extent.End >= extent.Start)
.OrderBy(static extent => extent.Start)
.ThenBy(static extent => extent.End)
.ToList();
List<(ulong Start, ulong End)> normalizedExtents = [];
if(orderedExtents.Count == 0) return normalizedExtents;
(ulong Start, ulong End) currentExtent = orderedExtents[0];
for(var i = 1; i < orderedExtents.Count; i++)
{
if(orderedExtents[i].Start <= currentExtent.End + 1)
{
currentExtent.End = Math.Max(currentExtent.End, orderedExtents[i].End);
continue;
}
normalizedExtents.Add(currentExtent);
currentExtent = orderedExtents[i];
}
normalizedExtents.Add(currentExtent);
return normalizedExtents;
}
}