Alright so i was trying to modify a Visual Studio project (DLL Project). And i needed to
add prxdll.h and i needed to use prx_attach/detach.
#include "dllmain.h"
#include "windows.h"
#include "prxdll.h"
BOOL APIENTRY DllMain(
const HINSTANCE instance,
const DWORD reason,
const PVOID reserved)
{
switch (reason) {
case DLL_PROCESS_ATTACH:
DisableThreadLibraryCalls(instance);
return prx_attach(instance);
case DLL_PROCESS_DETACH:
prx_detach(reserved);
break;
}
return TRUE;
}
Im gettin an error that has a code with C1083 and it writes this:
"Cannot Open include file: 'prxdll.h': No such file or directory"
And also it says "identifier prx_attach() is undefined" (it says this for prx_detach() too).
Because of these errors i cant compile/build this.
Related
I'm trying to get some code that works on the Mac to work on Windows. The code involves sharing data between a DLL, a static library and the main program. I suspect the problem arises because of the differences in the way that Unix and Windows handle global variables (see, for example, the answers here). However, I haven't figured out how to fix it. Here's a minimal example:
My Visual Studio 2019 solution contains three projects.
Project 1 makes the static library MarinaLib.lib
Header is MarinaLib.h
#pragma once
#include "Marina.h"
Class header is Marina.h
#pragma once
class Marina
{
public:
static Marina* get_marina();
protected:
static Marina* marina_instance;
};
Source file is Marina.cpp
#include "Marina.h"
Marina* Marina::marina_instance { nullptr };
Marina* Marina::get_marina()
{
if( !marina_instance )
marina_instance = new Marina();
return marina_instance;
}
Project 2 makes the DLL MarinaDLL.dll . It #defines MARINADLL_EXPORTS
First source file dllmain.cpp
// dllmain.cpp : Defines the entry point for the DLL application.
#include "framework.h"
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
Header file MarinaDLL.h is
#pragma once
#ifdef MARINADLL_EXPORTS
#define QUERY_DECLSPEC __declspec(dllexport)
#else
#define QUERY_DECLSPEC __declspec(dllimport)
#endif
QUERY_DECLSPEC void query_marina();
Second source file is marinaDLL.cpp
#include "MarinaDLL.h"
#include "..\MarinaLib\Marina.h"
void query_marina()
{
auto inst = Marina::get_marina();
}
Project 3 makes the executable MarinaExample.exe and does not #define MARINADLL_EXPORTS. It links in MarinaLib.lib and MarinaDLL.lib
The source file MarinaExample.cpp is
#include "MarinaLib.h"
#include "MarinaDLL.h"
int main()
{
auto instance = Marina::get_marina();
query_marina();
}
In the first line of main(), the code enters Marina::get_marina(). marina_instance is nullptr so the code creates a new Marina and makes marina_instance point to it. This is fine.
In the second line of main(), the code enters query_marina() and from there goes into Marina::get_marina(). At this point marina_instance is nullptr which is not what I want. I would like it to maintain its previous non-null value.
I've seen some examples of solutions to problems in similar code but they don't seem to work in my situation. Any suggestions on how to fix this?
Thanks.
add export modifier to class definition and export the whole class.
In dll and lib build define QUERY_DECLSPEC=export , in exe build as import :
class QUERY_DECLSPEC Marina
{
public:
static Marina* get_marina();
protected:
static Marina* marina_instance;
};
I would like to attach my DLL to a game to add more features.
The DLL is 95% done, the problem is in finding the best and easy way to load this DLL from within the game.
My idea is to use this technique:
dinput_ori.dll (old dll)
dinput.dll (my dll that points to dinput_ori.dll)
I don't need to access any members of original DLL, but only load my new DLL.
I am searching for a generic DLL source code that can do the following:
bool WINAPI DllMain(HMODULE hModule, DWORD dwReason, LPVOID lpReserved)
{
std::string DLLFileOri = "dinput_ori.dll";
switch (dwReason)
{
case DLL_PROCESS_ATTACH:
// Load dll
LoadOriDll(DLLFileOri);
MsgBox("This DLL was loaded.");
break;
case DLL_PROCESS_DETACH:
// Close the DLL
UnloadOriDll(DLLFileOri);
break;
}
return true;
}
In this case the name of my DLL is "dinput.dll".
Is there a generic source code that can do this ?
Thanks!
im trying to create DLL file and im having problem running functions inside DLLMAIN().
i want to do somthing like this :
#include "stdafx.h"
#include <stdio.h>
#include <windows.h>
INT APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved){
switch (ul_reason_for_call) {
case DLL_PROCESS_ATTACH:
foo1();
break;
case DLL_PROCESS_DETACH:
foo2()();
break;
}
return true;
}
void foo1(){
//code
}
void foo2(){
// code
}
but it does not work.
when I'm trying to build the file im getting
'foo1' identifier not found
'foo2' identifier not found
what I'm doing wrong here?
thanks!
Probably because you have not declared the functions. Put a
void foo1();
void foo2();
before yout DllMain and it will compile.
But be warned. You should not do anything substantial in DllMain. Especially anything involving loading libraries directly or indirectly might result in deadlocks.
I am trying to hook StartDocW to intercept printing via mhook. I use AppInit_DLLs to load my library.
DLL code is simple:
#include <windows.h>
#include "mhook/mhook-lib/mhook.h"
using StartDocPtr = int(*)(HDC, const DOCINFO*);
StartDocPtr orig;
int HookedStartDocW(HDC hdc, const DOCINFO* lpdi) {
return orig(hdc, lpdi);
}
BOOL WINAPI DllMain(__in HINSTANCE, __in DWORD Reason, __in LPVOID) {
orig = (StartDocPtr)GetProcAddress(GetModuleHandle("gdi32"), "StartDocW");
switch (Reason)
{
case DLL_PROCESS_ATTACH:
Mhook_SetHook((PVOID*)&orig, &HookedStartDocW);
break;
case DLL_PROCESS_DETACH:
Mhook_Unhook((PVOID*)&orig);
break;
}
}
Hook is working and printing is done OK. But If I change HookStartDocW to following:
int HookedStartDocW(HDC hdc, const DOCINFO* lpdi) {
char buf[40];
GetModuleFileName(NULL, buf, 40);
return orig(hdc, lpdi);
}
Programs on printing will crash immediately. Even if I just leave char buf[40] and comment GetModuleHandle - program will hang. Why is this happening?
Moreover, if program crashes\hangs on printing (if I add anything besides return orig(hdc, lpdi)) - PC starts to behave very weirdly, refusing to run programs, etc. If I reboot it - Windows just endlessly spins on boot screen, the only way to bring it back to live - is to boot via liveCD and rename\delete my hook DLL.
Printing programs: Excel 2016, notepad.
Compiler - MSVC 2015, x64 release DLL compilation, using MBCS instead of unicode.
Your hook is declared wrong.
Look at the actual declaration of StartDocW() in Wingdi.h:
__gdi_entry WINGDIAPI int WINAPI StartDocW(__in HDC hdc, __in CONST DOCINFOW *lpdi);
You can ignore __gdi_entry. WINGDIAPI simply resolves to __declspec(dllimport). What is important in this declaration is the WINAPI.
Like almost all Win32 API functions, StartDocW() uses the __stdcall calling convention. The WINAPI macro resolves to __stdcall.
Your code does not specify any calling convention at all, so it uses your compiler's default, which is usually __cdecl instead. So you are mismanaging the call stack. That is why your code crashes.
You are also using DOCINFO when you should be using DOCINFOW instead. It is clear in your code that you are compiling for MBCS and not for UNICODE, so DOCINFO maps to DOCINFOA. You can't pass a DOCINFOA to StartDocW(), it expects a DOCINFOW instead.
You need to fix your declarations, eg:
#include <windows.h>
#include "mhook/mhook-lib/mhook.h"
using StartDocPtr = int (WINAPI *)(HDC, const DOCINFOW*);
StartDocPtr orig = nullptr;
int WINAPI HookedStartDocW(HDC hdc, const DOCINFOW* lpdi) {
//...
return orig(hdc, lpdi);
}
BOOL WINAPI DllMain(__in HINSTANCE, __in DWORD Reason, __in LPVOID) {
orig = (StartDocPtr) GetProcAddress(GetModuleHandle(TEXT("gdi32")), "StartDocW");
switch (Reason)
{
case DLL_PROCESS_ATTACH:
Mhook_SetHook((PVOID*)&orig, &HookedStartDocW);
break;
case DLL_PROCESS_DETACH:
Mhook_Unhook((PVOID*)&orig);
break;
}
}
This question already has answers here:
How does RunDll32 work?
(2 answers)
Closed 8 years ago.
I have created a dead-simple DLL in Visual Studio 2010, a win32 project of type DLL.
Then I changed the DllMain to this:
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
MessageBox(0,L"Hey there!",0,0);
break;
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
and I used rundll32 vahid-win32.dll,dllmain to run it. Message box shows, but after that it gives
Error in vahid-win32.dll
Missing entry: dllmain
What is wrong with my DLL? or with me? :-)
Thanks in advance
Your messagebox doesn't come from you passing DllMain function name. Rather it is automatically called. But Rundll32 looking for a export function with name DllMain with dllexport declaration as given below.
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
MessageBox(0,L"Hey there!",0,0);
break;
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
extern "C" __declspec(dllexport) void mydllmain()
{
MessageBox(0,L"Hey there again!",0,0);
}
when you call RunDll32 with parameter mydllmain, it does me give both the message box with out error.
There's no reason to call DllMain via RunDLL, it's called automatically when the DLL is loaded.
Rather try running a custom function.
Aside from that, the problem is probably the exported name. You need to write a .def file for the DLL.
DllMain it is caused automatically, always. it to cause through rundll32, it will be caused, for this purpose it and is "entry point", you repeatedly try to cause it.