patcher.c

window编程,非常的好

#if _MSC_VER > 1000
#pragma once
#endif

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include "ApiHooks.h"


#define PatchRVA  0x103f
#define PatchSize 1

BYTE OrigValues[PatchSize] = {'X'};
BYTE WantedValues[PatchSize] = {'u'};


BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
					 )
{   
	if(ul_reason_for_call == DLL_PROCESS_ATTACH) {
		HMODULE main_module;
		ULONG OldAttr;
		DWORD i, j;
		if(main_module = GetModuleHandle(NULL)) {
			LPBYTE dest = (LPBYTE)main_module+PatchRVA;
			if(VirtualProtect(dest, PatchSize, PAGE_READWRITE, &OldAttr)) {
				for(i=0, j=0; i<PatchSize; ++i) 
					if(dest[i] == OrigValues[i]) ++j;
                    else break; 
                if (i == j) 
                while(i--)
					dest[i] = WantedValues[i];
				VirtualProtect(dest, PatchSize, OldAttr, &OldAttr);
			}   
		}	        
	}
    return TRUE;
}



__declspec(dllexport) API_HOOK ApiHookChain[1] = {
	{HOOKS_END}
};