[Programming] GetProcName

#define  MakePtr( cast, ptr, addValue )  (cast)((DWORD)(ptr) + (addValue))

LPVOID GetBaseAddress(DWORD dwAddr)
{
   HANDLE          hSnap;
   LPVOID          ret = NULL;
   MODULEENTRY32   me32;

   hSnap = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, 0);
   if (hSnap == NULL) {
       goto end;
   }

   memset(&me32, 0, sizeof(MODULEENTRY32));
   me32.dwSize = sizeof(MODULEENTRY32);
   if (Module32First(hSnap, &me32)) {
       do {
           if (((DWORD)me32.modBaseAddr <= dwAddr) &&
               (dwAddr < ((DWORD)me32.modBaseAddr +
                                 me32.modBaseSize))) {
               ret = me32.modBaseAddr;
               goto end;
           }

       } while (Module32Next(hSnap, &me32));
   }

end:
   if (hSnap)
       CloseHandle(hSnap);

   return ret;
}

void GetProcName(FARPROC proc, LPSTR lpBuf, DWORD dwSize)
{
   PIMAGE_DOS_HEADER       dosHeader;
   PIMAGE_NT_HEADERS       ntHeader;
   PIMAGE_EXPORT_DIRECTORY pExportDir;
   DWORD                   dwExportRVA;
   DWORD                   i;
   WORD                    offset;
   DWORD                  *ppNames;
   DWORD                  *ppFuncs;
   WORD                   *ppOrdinal;

   dosHeader = (PIMAGE_DOS_HEADER)GetBaseAddress((DWORD)proc);
   if (!dosHeader)
       goto end;

   ntHeader = MakePtr(PIMAGE_NT_HEADERS, dosHeader,
                          dosHeader->e_lfanew);
   if (ntHeader->Signature != IMAGE_NT_SIGNATURE)
       goto end;

   dwExportRVA = ntHeader->OptionalHeader.DataDirectory
                          [IMAGE_DIRECTORY_ENTRY_EXPORT].VirtualAddress;
   if (!dwExportRVA)
       goto end;

   pExportDir = MakePtr(PIMAGE_EXPORT_DIRECTORY, dosHeader,
                          dwExportRVA);

   ppNames = MakePtr(DWORD*, dosHeader,
                          pExportDir->AddressOfNames);
   ppFuncs = MakePtr(DWORD*, dosHeader,
                          pExportDir->AddressOfFunctions);
   ppOrdinal = MakePtr(WORD*, dosHeader,
                          pExportDir->AddressOfNameOrdinals);

   if (!ppNames || !ppFuncs || !ppOrdinal ||
       !pExportDir->NumberOfFunctions)
       goto end;

   for (i = 0; i <>NumberOfFunctions; i++) {
       offset = ppOrdinal[i];
       if (MakePtr(DWORD, dosHeader, ppFuncs[offset]) ==
                          (DWORD)proc) {
           strcpy_s(lpBuf, dwSize,
                          MakePtr(LPSTR, dosHeader, ppNames[i]));
           goto end;
       }
   }

end:
   return;
}



reflink: http://d.hatena.ne.jp/t04ya0/20080902/1220369795