Corsair K60 keyboard 51 opcode bug

hack_keyboard.c

gcc -I/usr/X11R6/include -L/usr/X11R6/lib -o hack_keyboard hack_keyboard.c -lX11 -lXtst -lXi -lrt

#include <string.h>
#include <ctype.h>
#include <X11/Xlib.h>
#include <X11/extensions/XInput.h>
#include <X11/Xutil.h>
#include <X11/extensions/XTest.h>
#include <X11/keysym.h>
#include <X11/Xlib.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

static int key_press_type = -1;

XDeviceInfo * find_device_info(
	Display	* display,
	 char const * name,
	 Bool only_extended)
{
	XDeviceInfo	*devices;
	XDeviceInfo *found = NULL;
	int		loop;
	int		num_devices;
	int		len = strlen(name);
	Bool	is_id = True;
	XID		id = (XID)-1;

	for(loop=0; loop<len; loop++) {
		if (!isdigit(name[loop])) {
			is_id = False;
			break;
		}
	}

	if (is_id) {
		id = atoi(name);
	}

	devices = XListInputDevices(display, &num_devices);

	for(loop=0; loop<num_devices; loop++) {
		if ((!only_extended || (devices[loop].use >= IsXExtensionDevice)) &&
			((!is_id && strcmp(devices[loop].name, name) == 0) ||
			 (is_id && devices[loop].id == id)))
		{
			if (found) {
				fprintf(stderr,
						"Warning: There are multiple devices named '%s'.\n"
						"To ensure the correct one is selected, please use "
						"the device ID instead.\n\n", name);
				return NULL;
			} else {
				found = &devices[loop];
			}
		}
	}
	return found;
}

 static int register_events(
	Display		*display,
	XDeviceInfo	*info,
	char const	*dev_name,
	Bool		handle_proximity)
 {
	int			number = 0;	/* number of events registered */
	XEventClass		event_list[7];
	int			i;
	XDevice		*device;
	Window		root_win;
	unsigned long	screen;
	XInputClassInfo	*ip;

	screen = DefaultScreen(display);
	root_win = RootWindow(display, screen);

	device = XOpenDevice(display, info->id);
	if (!device) {
		fprintf(stderr, "unable to open device '%s'\n", dev_name);
		return 0;
	}

	if (device->num_classes > 0) {
		for (ip = device->classes, i=0; i<info->num_classes; ip++, i++) {
			if (ip->input_class == KeyClass)
			{
				DeviceKeyPress(device, key_press_type, event_list[number]); number++;
				// DeviceKeyRelease(device, key_release_type, event_list[number]); number++;
			}
		}

		if (XSelectExtensionEvent(display, root_win, event_list, number)) {
			fprintf(stderr, "error selecting extended events\n");
			return 0;
		}
	}
	return number;
}

static void manage_events(
	Display * display)
{
 	XEvent Event;
	struct timespec time;
	double old_time = 0.0;

 	while(1) {
 		XNextEvent(display, &Event);
 		if (Event.type == key_press_type)
 		{
 			XDeviceKeyEvent * key = (XDeviceKeyEvent *) & Event;
 			if (key->keycode == 51)
 			{
				clock_gettime( CLOCK_MONOTONIC, &time );
				double new_time = time.tv_sec + time.tv_nsec/1000000000.0;

				if (new_time - old_time < 0.5)
				{
	 				printf("correction: %f\n", new_time - old_time);
					XTestFakeKeyEvent(display, 22, True, CurrentTime);
					XTestFakeKeyEvent(display, 22, False, CurrentTime);
					XFlush(display);
				}
				old_time = new_time;
 			}
 		}
 	}

}

int main(int argc, char const *argv[])
{

	if (argc < 2)
	{
		fprintf(stderr, "Usage %s device.\nUse xinput --list to identify the device.\n",
			argv[0]);
		return EXIT_FAILURE;
	}

	// Open the display
	Display * display = XOpenDisplay(NULL);
	if (!display) {
		return EXIT_FAILURE;
		fprintf(stderr, "Couln'd open display.\n");
	}

	// Check if the xinput extension is present
	int xi_opcode, event, error;
	if (!XQueryExtension(display, "XInputExtension", &xi_opcode, &event, &error)) {
		fprintf(stderr, "X Input extension not available.\n");
		XCloseDisplay(display);
		return EXIT_FAILURE;
	}

	// Get the device info
	XDeviceInfo * info = find_device_info(display, argv[1], True);
	if (!info) {
		fprintf(stderr, "Unable te fond device '%s'\n", argv[1]);
		XCloseDisplay(display);
		return EXIT_FAILURE;
	}

	if (register_events(display, info, argv[1], False))
		manage_events(display);

	fprintf(stderr, "Unable to register events\n");
	XCloseDisplay(display);
	return EXIT_FAILURE;

}