SAA2.cpp

#include <Windows.h>
#include <iostream>
#include "SAA2.h"

const char* SAA2_FILES_A[] =
{
	"loadscs.txd",
	"HANDLING.CFG",
	"surface.dat",
	"TIMECYC.DAT",
	"stream.ini",
	"melee.dat",
	"DEFAULT.DAT",
	"DEFAULT.IDE",
	"VEHICLES.IDE",
	"PEDS.IDE",
	"GTA.DAT",
	"SCRIPT.IMG",
	"LAn2.IDE",
	"LAxref.IDE",
	"props.IDE",
	"OBJECT.DAT",
	"CARMODS.DAT",
	"VEHICLE.TXD",
	"tracks2.dat",
	"tracks4.dat",
	"PED.DAT",
	"WEAPON.DAT",
	"main.scm",
	"AR_STATS.DAT",
	"shopping.dat",
};
/*
const wchar_t* SAA2_FILES_W[] =
{
	L"loadscs.txd",
	L"HANDLING.CFG",
	L"surface.dat",
	L"TIMECYC.DAT",
	L"stream.ini",
	L"melee.dat",
	L"DEFAULT.DAT",
	L"DEFAULT.IDE",
	L"VEHICLES.IDE",
	L"PEDS.IDE",
	L"GTA.DAT",
	L"SCRIPT.IMG",
	L"LAn2.IDE",
	L"LAxref.IDE",
	L"props.IDE",
	L"OBJECT.DAT",
	L"CARMODS.DAT",
	L"VEHICLE.TXD",
	L"tracks2.dat",
	L"tracks4.dat",
	L"PED.DAT",
	L"WEAPON.DAT",
	L"main.scm",
	L"AR_STATS.DAT",
	L"shopping.dat"
};
*/
char def_dir[MAX_PATH + 1] = {0};
void* CreateFileAAddr = NULL;

void Patch(void* source, void* replace, int num)
{
	DWORD dwOld;
	VirtualProtect(source, 5,  PAGE_EXECUTE_READWRITE, &dwOld);
	memcpy(source, replace, num);
}

static long long redirectBackup;

void Redirect(void* source, void* destination)
{
	DWORD dwOld;
	VirtualProtect(source, 5,  PAGE_EXECUTE_READWRITE, &dwOld);
	redirectBackup = *(long long*)source;
	*((unsigned char*)source) = 0xE9;
	*(DWORD*)(((char*)source) + 1) = (DWORD)((DWORD)destination - (DWORD)source) - 5;
}

void Restore(void* source)
{
	*(long long*)source = redirectBackup;
}

const char* GetFileNameFromPath(const char* szPath) {
	const char* szFileName = szPath;
	
	if (szFileName != NULL)
	{
		int len = strlen(szPath);	
		if (len > 0)
		{
			szFileName = szPath + len - 1;
			
			while (szFileName != szPath &&
			*szFileName != '\\' && *szFileName != '/')
				szFileName--;

			if (*szFileName == '\\' || *szFileName == '/')
				szFileName++;
		}
	}
	
	return szFileName;
}

HANDLE WINAPI CreateFileAHooked(
  _In_      LPCTSTR lpFileName,
  _In_      DWORD dwDesiredAccess,
  _In_      DWORD dwShareMode,
  _In_opt_  LPSECURITY_ATTRIBUTES lpSecurityAttributes,
  _In_      DWORD dwCreationDisposition,
  _In_      DWORD dwFlagsAndAttributes,
  _In_opt_  HANDLE hTemplateFile
)
{
	if (lpFileName == NULL)
		return INVALID_HANDLE_VALUE;

	const char* fileName = GetFileNameFromPath(lpFileName);
	bool fnd = false;

	for (int i = 0; !fnd && i < sizeof(SAA2_FILES_A)/sizeof(SAA2_FILES_A[0]); i++)
		if (SC(fileName, SAA2_FILES_A[i]))
			fnd = true;
	
	HANDLE hFile = INVALID_HANDLE_VALUE;

	Restore(CreateFileAAddr);
	
	hFile = CreateFileA(lpFileName, dwDesiredAccess, dwShareMode, lpSecurityAttributes, dwCreationDisposition, dwFlagsAndAttributes, hTemplateFile);

	Redirect(CreateFileAAddr, CreateFileAHooked);

	if (fnd)
	{
		
		char szFile[MAX_PATH + 1] = {0};
		wchar_t wszFileName[MAX_PATH + 1] = {0};
		int len = wsprintf(szFile, "%s\\CustomSAA2\\%s", def_dir, fileName);
		size_t convertedChars;
		mbstowcs_s(&convertedChars, wszFileName, szFile, len);

		if (hFile != INVALID_HANDLE_VALUE)
		{
			/*char buffer[256];
			DWORD dwBytesRead;
			DWORD dwBytesWritten = 0;
			
			do
			{
				ReadFile(hFile, buffer, sizeof(buffer), &dwBytesRead, NULL);
			} while (dwBytesRead > 0);
			*/

			CloseHandle(hFile);
		}

		hFile = CreateFileW(wszFileName, dwDesiredAccess, dwShareMode, lpSecurityAttributes,
			dwCreationDisposition, dwFlagsAndAttributes, hTemplateFile);
	}

	return hFile;
}

void SAA2Load()
{
	GetCurrentDirectory(sizeof(def_dir), def_dir);
	CreateFileAAddr = GetProcAddress(GetModuleHandle("kernel32.dll"), "CreateFileA");
	Redirect(CreateFileAAddr, CreateFileAHooked);
}