Files
Il2CppInspectorRedux/Il2CppInspector.Common/FileFormatStreams/NsoReader.cs

443 lines
16 KiB
C#

#nullable enable
using Il2CppInspector.Next;
using K4os.Compression.LZ4;
using System.Buffers;
using System.Buffers.Binary;
using System.Collections.Frozen;
using System.Collections.Immutable;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Numerics;
using System.Runtime.CompilerServices;
using VersionedSerialization;
namespace Il2CppInspector;
// These are slimmed-down versions of the project the loader originated from,
// which is why the API might look a bit weird
internal class ByteArrayBackingBuffer : IDisposable
{
[MemberNotNullWhen(true, nameof(Buffer))]
public bool Initialized { get; protected set; }
public bool IsLittleEndian { get; protected set; }
public bool Is32Bit { get; protected set; }
public ulong BaseAddress { get; protected set; }
public byte[]? Buffer { get; private set; }
protected Span<byte> Data => Buffer.AsSpan();
public void Initialize(long capacity, bool littleEndian, bool is32Bit, ulong baseAddress)
{
IsLittleEndian = littleEndian;
Is32Bit = is32Bit;
BaseAddress = baseAddress;
Buffer = new byte[capacity];
Initialized = true;
}
public void SetBaseAddress(ulong baseAddress)
{
Debug.Assert(BaseAddress == 0);
BaseAddress = baseAddress;
}
protected int TranslateVaToRva(ulong address)
{
Debug.Assert(address >= BaseAddress);
var relativeAddress = address - BaseAddress;
return checked((int)relativeAddress);
}
public T ReadObject<T>(ulong address, in StructVersion version) where T : unmanaged, IReadable
{
Debug.Assert(Initialized);
return IsLittleEndian
? Reader.LittleEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadVersionedObject<T>(in version)
: Reader.BigEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadVersionedObject<T>(in version);
}
public ImmutableArray<T> ReadObjectArray<T>(ulong address, long count, in StructVersion version) where T : unmanaged, IReadable
{
if (count == 0)
return [];
Debug.Assert(Initialized);
return IsLittleEndian
? Reader.LittleEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadVersionedObjectArray<T>(count, in version)
: Reader.BigEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadVersionedObjectArray<T>(count, in version);
}
public T ReadPrimitive<T>(ulong address) where T : unmanaged
{
Debug.Assert(Initialized);
return IsLittleEndian
? Reader.LittleEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadPrimitive<T>()
: Reader.BigEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadPrimitive<T>();
}
public ImmutableArray<T> ReadPrimitiveArray<T>(ulong address, long count) where T : unmanaged
{
Debug.Assert(Initialized);
return IsLittleEndian
? Reader.LittleEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadPrimitiveArray<T>(count)
: Reader.BigEndian(Data, TranslateVaToRva(address), new ReaderConfig(Is32Bit))
.ReadPrimitiveArray<T>(count);
}
public void WriteNUInt(ulong address, ulong value)
{
var region = Data.Slice(TranslateVaToRva(address), Is32Bit ? sizeof(uint) : sizeof(ulong));
if (Is32Bit)
{
if (IsLittleEndian)
BinaryPrimitives.WriteUInt32LittleEndian(region, (uint)value);
else
BinaryPrimitives.WriteUInt32BigEndian(region, (uint)value);
}
else
{
if (IsLittleEndian)
BinaryPrimitives.WriteUInt64LittleEndian(region, value);
else
BinaryPrimitives.WriteUInt64BigEndian(region, value);
}
}
public void WriteBytes(ulong address, ReadOnlySpan<byte> bytes)
{
bytes.CopyTo(Data.Slice(TranslateVaToRva(address), bytes.Length));
}
public void Clear(ulong address, long size)
{
Data.Slice(TranslateVaToRva(address), checked((int)size)).Clear();
}
public void Dispose()
{
GC.SuppressFinalize(this);
}
}
public class NsoReader : FileFormatStream<NsoReader>
{
public override string DefaultFilename => "main";
public override int Bits => _is32Bit ? 32 : 64;
public override string Arch => "ARM64";
public override string Format => "NSO";
protected override void Dispose(bool disposing)
{
if (disposing)
{
_mappedExecutable.Dispose();
}
base.Dispose(disposing);
}
protected override bool Init()
{
var magic = ReadPrimitive<uint>();
if (magic != NsoHeader.ExpectedMagic)
return false;
Position = 0;
LoadInternal();
Position = 0;
Write(_mappedExecutable.Buffer);
return true;
}
private readonly ByteArrayBackingBuffer _mappedExecutable = new();
private FrozenDictionary<DynamicTag, ulong> _dynamicEntries = FrozenDictionary<DynamicTag, ulong>.Empty;
private ImmutableArray<(ulong Start, ulong End)> _relocationEntryRegions = [];
private bool _is32Bit;
private void LoadInternal()
{
var header = ReadVersionedObject<NsoHeader>();
var totalLength = header.TextSegment.Size + header.RoSegment.Size + header.DataSegment.Size + header.BssSize;
_mappedExecutable.Initialize(totalLength, true, false, 0);
LoadSegment(in header.TextSegment, header.TextFileSize, header.Flags.HasFlag(SegmentFlags.TextCompress));
LoadSegment(in header.RoSegment, header.RoFileSize, header.Flags.HasFlag(SegmentFlags.RoCompress));
LoadSegment(in header.DataSegment, header.DataFileSize, header.Flags.HasFlag(SegmentFlags.DataCompress));
LoadMappedExecutable(header.TextSegment.MemoryOffset);
}
private void LoadMappedExecutable(uint textSegmentRva)
{
var modInfoHeader = _mappedExecutable.ReadObject<ModInfoHeader>(textSegmentRva, default);
var modHeader = _mappedExecutable.ReadObject<ModHeader>(modInfoHeader.ModOffset, default);
Debug.Assert(modHeader.ValidMagic);
// check if we are loading a 32-bit binary
// by checking if we have a full .dynamic entry in the first (or third) dynamic slot
var firstEntry = _mappedExecutable.ReadPrimitive<ulong>(modInfoHeader.ModOffset + modHeader.DynamicOffset);
var thirdEntry = _mappedExecutable.ReadPrimitive<ulong>(modInfoHeader.ModOffset + modHeader.DynamicOffset + (2 * 0x8));
_is32Bit = firstEntry > uint.MaxValue || thirdEntry > uint.MaxValue;
// These were pulled from nxo64.py, the IDA loader for switch objects
var baseAddress = Is32Bit ? 0x60000000u : 0x7100000000u;
GlobalOffset = baseAddress;
_mappedExecutable.SetBaseAddress(baseAddress);
var currentDynamicOffset = modInfoHeader.ModOffset + modHeader.DynamicOffset;
var dynamicEntries = new Dictionary<DynamicTag, ulong>();
var dynamicEntrySize = (uint)DynamicEntry.StructSize(config: new ReaderConfig(Is32Bit));
while (true)
{
var entry = _mappedExecutable.ReadObject<DynamicEntry>(ImageBase + currentDynamicOffset, default);
if (entry.Tag == DynamicTag.DT_NULL)
break;
dynamicEntries[entry.Tag] = entry.Value;
currentDynamicOffset += dynamicEntrySize;
}
_dynamicEntries = dynamicEntries.ToFrozenDictionary();
ApplyRelocations();
}
private void LoadSegment(ref readonly SegmentHeader header, uint fileSize, bool isCompressed)
{
var reader = new Reader<BinaryObjectStreamReader>(this)
{
Offset = checked((int)header.FileOffset)
};
var data = reader.ReadBytes(checked((int)fileSize));
if (!isCompressed)
{
Debug.Assert(header.Size == fileSize);
_mappedExecutable.WriteBytes(header.MemoryOffset, data);
}
else
{
var rented = ArrayPool<byte>.Shared.Rent(checked((int)header.Size));
var decompressed = rented.AsSpan(0, checked((int)header.Size));
var result = LZ4Codec.Decode(data, decompressed);
Debug.Assert(result == header.Size);
_ = result;
_mappedExecutable.WriteBytes(header.MemoryOffset, decompressed);
ArrayPool<byte>.Shared.Return(rented);
}
}
// Copied and trimmed down from ElfBinary
private void ApplyRelocations()
{
if (!_dynamicEntries.TryGetValue(DynamicTag.DT_SYMTAB, out var symtabAddress)
|| !_dynamicEntries.TryGetValue(DynamicTag.DT_SYMENT, out var symtabEntrySize))
return;
List<(ulong Start, ulong End)> relocationRegions = [];
if (_dynamicEntries.TryGetValue(DynamicTag.DT_REL, out var relAddress))
{
var relocationSize = _dynamicEntries[DynamicTag.DT_RELSZ];
ApplyRelocationsImpl(ParseRelSection(relAddress, relocationSize));
relocationRegions.Add((relAddress, relAddress + relocationSize));
}
else if (_dynamicEntries.TryGetValue(DynamicTag.DT_RELA, out var relaAddress))
{
var relocationSize = _dynamicEntries[DynamicTag.DT_RELASZ];
ApplyRelocationsImpl(ParseRelaSection(relaAddress, relocationSize));
relocationRegions.Add((relaAddress, relaAddress + relocationSize));
}
if (_dynamicEntries.TryGetValue(DynamicTag.DT_JMPREL, out var jmprelAddress))
{
var size = _dynamicEntries[DynamicTag.DT_PLTRELSZ];
var type = (DynamicTag)_dynamicEntries[DynamicTag.DT_PLTREL];
ApplyRelocationsImpl(type == DynamicTag.DT_REL
? ParseRelSection(jmprelAddress, size)
: ParseRelaSection(jmprelAddress, size));
relocationRegions.Add((jmprelAddress, jmprelAddress + size));
}
if (_dynamicEntries.TryGetValue(DynamicTag.DT_RELR, out var relrAddress))
{
var size = _dynamicEntries[DynamicTag.DT_RELRSZ];
ApplyRelrRelocations(relrAddress, size);
relocationRegions.Add((relrAddress, relrAddress + size));
}
_relocationEntryRegions = [.. relocationRegions];
// Clear out relocation sections in memory so searching is faster
foreach (var (start, end) in _relocationEntryRegions)
{
_mappedExecutable.Clear(ImageBase + start, checked((long)(end - start)));
}
return;
void ApplyRelocationsImpl(ICollection<(ulong Offset, ulong Info, long? Addend)> relocations)
{
if (relocations.Count == 0)
return;
var symbolCache = new Dictionary<uint, SymbolEntry>();
foreach (var relocation in relocations)
{
var offset = relocation.Offset;
var type = (RelocationType)(Is32Bit ? relocation.Info & byte.MaxValue : relocation.Info & uint.MaxValue);
var symbolIndex = (uint)(relocation.Info >> (Is32Bit ? 8 : 32));
var addend = checked((ulong)(relocation.Addend ?? _mappedExecutable.ReadPrimitive<long>(ImageBase + offset)));
if (!symbolCache.TryGetValue(symbolIndex, out var symbolEntry))
{
var symtabEntryAddress = symtabAddress + symbolIndex * symtabEntrySize;
symbolEntry = _mappedExecutable.ReadObject<SymbolEntry>(ImageBase + symtabEntryAddress, default);
symbolCache[symbolIndex] = symbolEntry;
}
var (value, handled) = type switch
{
RelocationType.R_ARM_ABS32 or RelocationType.R_AARCH64_ABS64 => (symbolEntry.Value + addend, true),
RelocationType.R_ARM_REL32 or RelocationType.R_AARCH64_PREL64 => (symbolEntry.Value + relocation.Offset - addend, true),
RelocationType.R_ARM_COPY => (symbolEntry.Value, true),
RelocationType.R_AARCH64_GLOB_DAT => (symbolEntry.Value + addend, true),
RelocationType.R_AARCH64_JUMP_SLOT => (symbolEntry.Value + addend, true),
RelocationType.R_AARCH64_RELATIVE => (symbolEntry.Value + addend, true),
_ => (0uL, false)
};
if (handled)
{
_mappedExecutable.WriteNUInt(ImageBase + offset, ImageBase + value);
}
else
{
Debug.Assert(false);
}
}
}
List<(ulong, ulong, long?)> ParseRelSection(ulong rva, ulong size)
{
var entrySize = _dynamicEntries[DynamicTag.DT_RELENT];
var entryCount = size / entrySize;
return [.. _mappedExecutable.ReadObjectArray<RelEntry>(ImageBase + rva, checked((int)entryCount), default)
.Select<RelEntry, (ulong, ulong, long?)>(x => (x.Offset, x.Info, null))];
}
List<(ulong, ulong, long?)> ParseRelaSection(ulong rva, ulong size)
{
var entrySize = _dynamicEntries[DynamicTag.DT_RELAENT];
var entryCount = size / entrySize;
return [.. _mappedExecutable.ReadObjectArray<RelaEntry>(ImageBase + rva, checked((int)entryCount), default)
.Select<RelaEntry, (ulong, ulong, long?)>(x => (x.Offset, x.Info, x.Addend))];
}
void ApplyRelrRelocations(ulong address, ulong size)
{
if (Is32Bit)
{
ApplyRelrRelocationsImpl<uint>();
}
else
{
ApplyRelrRelocationsImpl<ulong>();
}
return;
void ApplyRelrRelocationsImpl<T>() where T : unmanaged, IUnsignedNumber<T>, IBinaryNumber<T>
{
Debug.Assert(typeof(T) == typeof(uint) || typeof(T) == typeof(ulong));
var entrySize = _dynamicEntries[DynamicTag.DT_RELRENT];
var entryCount = size / entrySize;
Debug.Assert(entrySize == (uint)Unsafe.SizeOf<T>());
var relrWords = _mappedExecutable.ReadPrimitiveArray<T>(ImageBase + address, checked((int)entryCount));
var baseAddr = 0ul;
for (int i = 0; i < relrWords.Length; i++)
{
var word = ulong.CreateChecked(relrWords[i]);
ulong offset;
if ((word & 1) == 0)
{
offset = word;
var value = ulong.CreateChecked(_mappedExecutable.ReadPrimitive<T>(ImageBase + offset));
_mappedExecutable.WriteNUInt(ImageBase + offset, ImageBase + value);
baseAddr = offset + entrySize;
}
else
{
offset = baseAddr;
while (word != 0)
{
word >>= 1;
if ((word & 1) != 0)
{
var value = ulong.CreateChecked(_mappedExecutable.ReadPrimitive<T>(ImageBase + offset));
_mappedExecutable.WriteNUInt(ImageBase + offset, ImageBase + value);
}
offset += entrySize;
}
baseAddr += (8 * entrySize - 1) * entrySize;
}
}
}
}
}
public override uint[] GetFunctionTable() => [];
public override bool TryMapVATR(ulong uiAddr, out uint fileOffset)
{
if (uiAddr < ImageBase)
{
fileOffset = 0;
return false;
}
fileOffset = checked((uint)(uiAddr - ImageBase));
if (fileOffset > Length)
{
return false;
}
return true;
}
public override ulong MapFileOffsetToVA(uint offset)
=> ImageBase + offset;
}