How to ignore injected input in only one window? - c++

Question

I have two devices that create keyboard input, one of them is a real keyboard and the other uses SendInput() to send Injected keyboard input. I am modifying an existing program that uses a hook to send the keyboard message only to its own window and blocks the input globally to other programs. However I do not want the Injected input to be blocked, and I also don't want the program to process the Injected input.
I used a WH_KEYBOARD_LL hook to determine if the input is Injected, Then I used a global WH_KEYBOARD hook to send the message only to the window if it is the real keyboard. What I am looking for is a way to sendMessage() to everything except the main window. I couldn't find a method in the documentation to do this though, so I decided to pass the hook farther down.
// WH_KEYBOARD
static LRESULT CALLBACK KeyboardProc(int code, WPARAM wParam, LPARAM lParam) {
if (code < 0) {
return CallNextHookEx(hookHandle, code, wParam, lParam);
}
//Report the event to the main window, but do not pass it to the hook chain
if (realKeyboard) {
SendMessage(hwndServer, WM_HOOK, wParam, lParam);//only listen to real keyboard, block emulated one
}
else {
//what i want is to sendMessage to everythng except the main window
return CallNextHookEx(hookHandle, code, wParam, lParam); //let injected keyboard passthrough
//however we want to ignore injected inputs in the main window(keyboard program).
}
return 1;
}
I created a local WH_GETMESSAGE hook using GetCurrentThreadId(), to see if I could ignore the injected input there.
// WH_GETMESSAGE
static LRESULT CALLBACK GetMessageProc(int code, WPARAM wParam, LPARAM lParam) {
if (code < 0) {
return CallNextHookEx(hookHandle, code, wParam, lParam);
}
if (!realKeyboard) {
MSG * info = (MSG *)lParam;
info->message = WM_NULL;
}
return CallNextHookEx(hookHandle, code, wParam, lParam);
}
I read somewhere that info->message = WM_NULL; would work to block the message but it doesn't seem to have an effect. I also Tried creating a message loop something like this but it didn't work either.
while (PeekMessage(&msg, 0, 0, 0, PM_REMOVE)) {
if(IsRealKeyboard()){
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
Any ideas how I can ignore the injected message only in the main window and let it through to the rest of the system?

Answer 1

You could use RAW INPUT in the target window and process the WM_INPUT message, then get the Raw Input buffer via GetRawInputData.