r5sdk/r5dev/tier0/memaddr.cpp
Kawe Mazidjatari 359820615f Move low level code to tier0/tier1
Moved to tier0/tier1 so it could be compiled into a static library in the future.
2023-05-06 22:59:01 +02:00

292 lines
11 KiB
C++

//===========================================================================//
//
// Purpose: Implementation of the CMemory class.
//
//===========================================================================//
#include "core/stdafx.h"
#include "tier0/memaddr.h"
#include "tier1/utility.h"
//-----------------------------------------------------------------------------
// Purpose: check array of opcodes starting from current address
// Input : vOpcodeArray -
// Output : true if equal, false otherwise
//-----------------------------------------------------------------------------
bool CMemory::CheckOpCodes(const vector<uint8_t> vOpcodeArray) const
{
uintptr_t ref = ptr;
// Loop forward in the ptr class member.
for (auto [byteAtCurrentAddress, i] = std::tuple<uint8_t, size_t>{ uint8_t(), (size_t)0 }; i < vOpcodeArray.size(); i++, ref++)
{
byteAtCurrentAddress = *reinterpret_cast<uint8_t*>(ref);
// If byte at ptr doesn't equal in the byte array return false.
if (byteAtCurrentAddress != vOpcodeArray[i])
return false;
}
return true;
}
//-----------------------------------------------------------------------------
// Purpose: patch array of opcodes starting from current address
// Input : vOpcodeArray -
//-----------------------------------------------------------------------------
void CMemory::Patch(const vector<uint8_t> vOpcodeArray) const
{
DWORD oldProt = NULL;
SIZE_T dwSize = vOpcodeArray.size();
VirtualProtect(reinterpret_cast<void*>(ptr), dwSize, PAGE_EXECUTE_READWRITE, &oldProt); // Patch page to be able to read and write to it.
for (size_t i = 0; i < vOpcodeArray.size(); i++)
{
*reinterpret_cast<uint8_t*>(ptr + i) = vOpcodeArray[i]; // Write opcodes to Address.
}
dwSize = vOpcodeArray.size();
VirtualProtect(reinterpret_cast<void*>(ptr), dwSize, oldProt, &oldProt); // Restore protection.
}
//-----------------------------------------------------------------------------
// Purpose: patch string constant at current address
// Input : &svString -
//-----------------------------------------------------------------------------
void CMemory::PatchString(const string& svString) const
{
DWORD oldProt = NULL;
SIZE_T dwSize = svString.size();
const vector<char> bytes(svString.begin(), svString.end());
VirtualProtect(reinterpret_cast<void*>(ptr), dwSize, PAGE_EXECUTE_READWRITE, &oldProt); // Patch page to be able to read and write to it.
for (size_t i = 0; i < svString.size(); i++)
{
*reinterpret_cast<uint8_t*>(ptr + i) = bytes[i]; // Write string to Address.
}
dwSize = svString.size();
VirtualProtect(reinterpret_cast<void*>(ptr), dwSize, oldProt, &oldProt); // Restore protection.
}
//-----------------------------------------------------------------------------
// Purpose: find array of bytes in process memory
// Input : *szPattern -
// searchDirect -
// opCodesToScan -
// occurrence -
// Output : CMemory
//-----------------------------------------------------------------------------
CMemory CMemory::FindPattern(const string& svPattern, const Direction searchDirect, const int opCodesToScan, const ptrdiff_t occurrence) const
{
uint8_t* pScanBytes = reinterpret_cast<uint8_t*>(ptr); // Get the base of the module.
const vector<int> PatternBytes = PatternToBytes(svPattern); // Convert our pattern to a byte array.
const pair<size_t, const int*> bytesInfo = std::make_pair<size_t, const int*>(PatternBytes.size(), PatternBytes.data()); // Get the size and data of our bytes.
ptrdiff_t occurrences = 0;
for (long i = 01; i < opCodesToScan + bytesInfo.first; i++)
{
bool bFound = true;
int nMemOffset = searchDirect == Direction::DOWN ? i : -i;
for (DWORD j = 0ul; j < bytesInfo.first; j++)
{
// If either the current byte equals to the byte in our pattern or our current byte in the pattern is a wildcard
// our if clause will be false.
uint8_t currentByte = *(pScanBytes + nMemOffset + j);
_mm_prefetch(reinterpret_cast<const CHAR*>(static_cast<int64>(currentByte + nMemOffset + 64)), _MM_HINT_T0); // precache some data in L1.
if (currentByte != bytesInfo.second[j] && bytesInfo.second[j] != -1)
{
bFound = false;
break;
}
}
if (bFound)
{
occurrences++;
if (occurrence == occurrences)
{
return CMemory(&*(pScanBytes + nMemOffset));
}
}
}
return CMemory();
}
//-----------------------------------------------------------------------------
// Purpose: find array of bytes in process memory starting from current address
// Input : *szPattern -
// searchDirect -
// opCodesToScan -
// occurrence -
// Output : CMemory
//-----------------------------------------------------------------------------
CMemory CMemory::FindPatternSelf(const string& svPattern, const Direction searchDirect, const int opCodesToScan, const ptrdiff_t occurrence)
{
uint8_t* pScanBytes = reinterpret_cast<uint8_t*>(ptr); // Get the base of the module.
const vector<int> PatternBytes = PatternToBytes(svPattern); // Convert our pattern to a byte array.
const pair<size_t, const int*> bytesInfo = std::make_pair<size_t, const int*>(PatternBytes.size(), PatternBytes.data()); // Get the size and data of our bytes.
ptrdiff_t occurrences = 0;
for (long i = 01; i < opCodesToScan + bytesInfo.first; i++)
{
bool bFound = true;
int nMemOffset = searchDirect == Direction::DOWN ? i : -i;
for (DWORD j = 0ul; j < bytesInfo.first; j++)
{
// If either the current byte equals to the byte in our pattern or our current byte in the pattern is a wildcard
// our if clause will be false.
uint8_t currentByte = *(pScanBytes + nMemOffset + j);
_mm_prefetch(reinterpret_cast<const CHAR*>(static_cast<int64>(currentByte + nMemOffset + 64)), _MM_HINT_T0); // precache some data in L1.
if (currentByte != bytesInfo.second[j] && bytesInfo.second[j] != -1)
{
bFound = false;
break;
}
}
if (bFound)
{
occurrences++;
if (occurrence == occurrences)
{
ptr = uintptr_t(&*(pScanBytes + nMemOffset));
return *this;
}
}
}
ptr = uintptr_t();
return *this;
}
//-----------------------------------------------------------------------------
// Purpose: ResolveRelativeAddress wrapper
// Input : opcodeOffset -
// nextInstructionOffset -
// Output : CMemory
//-----------------------------------------------------------------------------
CMemory CMemory::FollowNearCall(const ptrdiff_t opcodeOffset, const ptrdiff_t nextInstructionOffset) const
{
return ResolveRelativeAddress(opcodeOffset, nextInstructionOffset);
}
//-----------------------------------------------------------------------------
// Purpose: ResolveRelativeAddressSelf wrapper
// Input : opcodeOffset -
// nextInstructionOffset -
// Output : CMemory
//-----------------------------------------------------------------------------
CMemory CMemory::FollowNearCallSelf(const ptrdiff_t opcodeOffset, const ptrdiff_t nextInstructionOffset)
{
return ResolveRelativeAddressSelf(opcodeOffset, nextInstructionOffset);
}
//-----------------------------------------------------------------------------
// Purpose: resolves the relative pointer to offset
// Input : registerOffset -
// nextInstructionOffset -
// Output : CMemory
//-----------------------------------------------------------------------------
CMemory CMemory::ResolveRelativeAddress(const ptrdiff_t registerOffset, const ptrdiff_t nextInstructionOffset) const
{
// Skip register.
const uintptr_t skipRegister = ptr + registerOffset;
// Get 4-byte long relative Address.
const int32_t relativeAddress = *reinterpret_cast<int32_t*>(skipRegister);
// Get location of next instruction.
const uintptr_t nextInstruction = ptr + nextInstructionOffset;
// Get function location via adding relative Address to next instruction.
return CMemory(nextInstruction + relativeAddress);
}
//-----------------------------------------------------------------------------
// Purpose: resolves the relative pointer to offset from current address
// Input : registerOffset -
// nextInstructionOffset -
// Output : CMemory
//-----------------------------------------------------------------------------
CMemory CMemory::ResolveRelativeAddressSelf(const ptrdiff_t registerOffset, const ptrdiff_t nextInstructionOffset)
{
// Skip register.
const uintptr_t skipRegister = ptr + registerOffset;
// Get 4-byte long relative Address.
const int32_t relativeAddress = *reinterpret_cast<int32_t*>(skipRegister);
// Get location of next instruction.
const uintptr_t nextInstruction = ptr + nextInstructionOffset;
// Get function location via adding relative Address to next instruction.
ptr = nextInstruction + relativeAddress;
return *this;
}
//-----------------------------------------------------------------------------
// Purpose: resolve all 'call' references to ptr
// (This is very slow only use for mass patching.)
// Input : sectionBase -
// sectionSize -
// Output : vector<CMemory>
//-----------------------------------------------------------------------------
vector<CMemory> CMemory::FindAllCallReferences(const uintptr_t sectionBase, const size_t sectionSize)
{
vector <CMemory> referencesInfo = {};
uint8_t* pTextStart = reinterpret_cast<uint8_t*>(sectionBase);
for (size_t i = 0ull; i < sectionSize - 0x5; i++, _mm_prefetch(reinterpret_cast<const char*>(pTextStart + 64), _MM_HINT_NTA))
{
if (pTextStart[i] == CALL)
{
CMemory memAddr = CMemory(&pTextStart[i]);
if (!memAddr.Offset(0x1).CheckOpCodes({ 0x00, 0x00, 0x00, 0x00 })) // Check if its not a dynamic resolved call.
{
if (memAddr.FollowNearCall() == *this)
referencesInfo.push_back(memAddr);
}
}
}
return referencesInfo;
}
//-----------------------------------------------------------------------------
// Purpose: patch virtual method to point to a user set function
// Input : virtualTable -
// pHookMethod -
// methodIndex -
// pOriginalMethod -
// Output : void** via pOriginalMethod
//-----------------------------------------------------------------------------
void CMemory::HookVirtualMethod(const uintptr_t virtualTable, const void* pHookMethod, const ptrdiff_t methodIndex, void** ppOriginalMethod)
{
DWORD oldProt = NULL;
// Calculate delta to next virtual method.
const uintptr_t virtualMethod = virtualTable + (methodIndex * sizeof(ptrdiff_t));
// Preserve original function.
const uintptr_t originalFunction = *reinterpret_cast<uintptr_t*>(virtualMethod);
// Set page for current virtual method to execute n read n write.
VirtualProtect(reinterpret_cast<void*>(virtualMethod), sizeof(virtualMethod), PAGE_EXECUTE_READWRITE, &oldProt);
// Set virtual method to our hook.
*reinterpret_cast<uintptr_t*>(virtualMethod) = reinterpret_cast<uintptr_t>(pHookMethod);
// Restore original page.
VirtualProtect(reinterpret_cast<void*>(virtualMethod), sizeof(virtualMethod), oldProt, &oldProt);
// Move original function into argument.
*ppOriginalMethod = reinterpret_cast<void*>(originalFunction);
}