117 lines
3.4 KiB
C
117 lines
3.4 KiB
C
|
// this file builds a "lib" (really just an .obj) for people who want to
|
||
|
|
// use the kernel32.dll delay-load exception handler.
|
||
|
|
|
||
|
|
#define DELAYLOAD_VERSION 0x0200
|
||
|
|
|
||
|
|
#include <windows.h>
|
||
|
|
#include <delayimp.h>
|
||
|
|
|
||
|
|
// kernel32's base hmodule
|
||
|
|
extern HANDLE BaseDllHandle;
|
||
|
|
|
||
|
|
// prototype (implemented in kernl32p.lib)
|
||
|
|
FARPROC
|
||
|
|
DelayLoadFailureHook (
|
||
|
|
LPCSTR pszDllName,
|
||
|
|
LPCSTR pszProcName
|
||
|
|
);
|
||
|
|
|
||
|
|
|
||
|
|
// people who care about being notified of dll loadlibray will override this
|
||
|
|
PfnDliHook __pfnDliNotifyHook2;
|
||
|
|
|
||
|
|
// Instead of implementing a "notify hook" (__pfnDliNotifyHook2) or a
|
||
|
|
// "failure hook" (__pfnDliFailureHook2) we are just going to up and implement
|
||
|
|
// __delayLoadHelper2 which is the stub who's fn. pointer is filled in all
|
||
|
|
// of the import tables for delayloaded entries.
|
||
|
|
//
|
||
|
|
// This will effectively bypass the linker's LoadLibrary/GetProcAddress thunk code
|
||
|
|
// as we simply duplicate it here (most of this fn. was stolen from \vc7\delayhlp.cpp)
|
||
|
|
|
||
|
|
FARPROC
|
||
|
|
WINAPI
|
||
|
|
__delayLoadHelper2(
|
||
|
|
PCImgDelayDescr pidd,
|
||
|
|
FARPROC * ppfnIATEntry
|
||
|
|
)
|
||
|
|
{
|
||
|
|
UINT iINT;
|
||
|
|
PCImgThunkData pitd;
|
||
|
|
LPCSTR pszProcName;
|
||
|
|
LPCSTR pszDllName = (LPCSTR)PFromRva(pidd->rvaDLLName, NULL);
|
||
|
|
HMODULE* phmod = (HMODULE*)PFromRva(pidd->rvaHmod, NULL);
|
||
|
|
PCImgThunkData pIAT = (PCImgThunkData)PFromRva(pidd->rvaIAT, NULL);
|
||
|
|
PCImgThunkData pINT = (PCImgThunkData)PFromRva(pidd->rvaINT, NULL);
|
||
|
|
FARPROC pfnRet = 0;
|
||
|
|
HMODULE hmod = *phmod;
|
||
|
|
|
||
|
|
// Calculate the index for the name in the import name table.
|
||
|
|
// N.B. it is ordered the same as the IAT entries so the calculation
|
||
|
|
// comes from the IAT side.
|
||
|
|
//
|
||
|
|
iINT = IndexFromPImgThunkData((PCImgThunkData)ppfnIATEntry, pIAT);
|
||
|
|
|
||
|
|
pitd = &(pINT[iINT]);
|
||
|
|
|
||
|
|
if (!IMAGE_SNAP_BY_ORDINAL(pitd->u1.Ordinal))
|
||
|
|
{
|
||
|
|
PIMAGE_IMPORT_BY_NAME pibn = (PIMAGE_IMPORT_BY_NAME)PFromRva((RVA)pitd->u1.AddressOfData, NULL);
|
||
|
|
|
||
|
|
pszProcName = pibn->Name;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
pszProcName = MAKEINTRESOURCEA(IMAGE_ORDINAL(pitd->u1.Ordinal));
|
||
|
|
}
|
||
|
|
|
||
|
|
if (hmod == 0)
|
||
|
|
{
|
||
|
|
hmod = LoadLibraryA(pszDllName);
|
||
|
|
|
||
|
|
if (hmod != 0)
|
||
|
|
{
|
||
|
|
// Store the library handle. If it is already there, we infer
|
||
|
|
// that another thread got there first, and we need to do a
|
||
|
|
// FreeLibrary() to reduce the refcount
|
||
|
|
//
|
||
|
|
HMODULE hmodT = (HMODULE)InterlockedCompareExchangePointer((void**)phmod, (void*)hmod, NULL);
|
||
|
|
if (hmodT == NULL)
|
||
|
|
{
|
||
|
|
DelayLoadInfo dli = {0};
|
||
|
|
|
||
|
|
dli.cb = sizeof(dli);
|
||
|
|
dli.szDll = pszDllName;
|
||
|
|
dli.hmodCur = hmod;
|
||
|
|
|
||
|
|
// call the notify hook to inform them that we have successfully LoadLibrary'ed a dll.
|
||
|
|
// (we do this in case they want to free it when they unload)
|
||
|
|
if (__pfnDliNotifyHook2 != NULL)
|
||
|
|
{
|
||
|
|
__pfnDliNotifyHook2(dliNoteEndProcessing, &dli);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
// some other thread beat us to loading this module, use the existing hmod
|
||
|
|
FreeLibrary(hmod);
|
||
|
|
hmod = hmodT;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (hmod)
|
||
|
|
{
|
||
|
|
// Go for the procedure now.
|
||
|
|
pfnRet = GetProcAddress(hmod, pszProcName);
|
||
|
|
}
|
||
|
|
|
||
|
|
if (pfnRet == 0)
|
||
|
|
{
|
||
|
|
pfnRet = DelayLoadFailureHook(pszDllName, pszProcName);
|
||
|
|
}
|
||
|
|
|
||
|
|
*ppfnIATEntry = pfnRet;
|
||
|
|
|
||
|
|
return pfnRet;
|
||
|
|
}
|