docker-idrac6/keycode-hack.c

// from https://github.com/anchor/idrac-kvm-keyboard-fix
/*
 * Shared library hack to translate evdev keycodes to old style keycodes.
 */
#include <stdio.h>
#include <unistd.h>
#include <dlfcn.h>
#include <X11/Xlib.h>
#include <X11/keysym.h>


static int (*real_XNextEvent)(Display *, XEvent *) = NULL;
static KeyCode (*real_XKeysymToKeycode)(Display *, KeySym) = NULL;
static KeySym (*sym_XKeycodeToKeysym)(Display *, KeyCode, int) = NULL;
static int hack_initialised = 0;

#define DEBUG 0

#ifdef DEBUG
static FILE *fd = NULL;
#endif

static void
hack_init(void)
{
	void *h;

	h = dlopen("libX11.so", RTLD_LAZY);
	if (h == NULL) {
		h = dlopen("libX11.so.6", RTLD_LAZY);
		if (h == NULL) {
			fprintf(stderr, "Unable to open libX11\n");
			_exit(1);
		}
	}

	real_XNextEvent = dlsym(h, "XNextEvent");
	if (real_XNextEvent == NULL) {
		fprintf(stderr, "Unable to find symbol\n");
		_exit(1);
	}

	real_XKeysymToKeycode = dlsym(h, "XKeysymToKeycode");
	if (real_XKeysymToKeycode == NULL) {
		fprintf(stderr, "Unable to find symbol\n");
		_exit(1);
	}

	sym_XKeycodeToKeysym = dlsym(h, "XKeycodeToKeysym");
	if (sym_XKeycodeToKeysym == NULL) {
		fprintf(stderr, "Unable to find symbol\n");
		_exit(1);
	}

#ifdef DEBUG
	if (fd == NULL) {
		fd = fopen("/tmp/keycode-log", "a");
		if (fd == NULL)
			fprintf(stderr, "Unable to open key-log\n");
	}
#endif

	hack_initialised = 1;
}

int
XNextEvent(Display *display, XEvent *event)
{
	int r;

	if (!hack_initialised)
		hack_init();

	r = real_XNextEvent(display, event);

	if (event->type == KeyPress || event->type == KeyRelease) {
		XKeyEvent *keyevent;
		KeySym keysym;

		keyevent = (XKeyEvent *)event;
#ifdef DEBUG
		fprintf(fd, "KeyEvent: %d\n", keyevent->keycode);
		fflush(fd);
#endif

		/* mangle keycodes */
		keysym = sym_XKeycodeToKeysym(display, keyevent->keycode, 0);
		switch (keysym) {
		  /* Modifiers */
		  case XK_Shift_R: keyevent->keycode = 62; break;
		  case XK_Shift_L: keyevent->keycode = 50; break;
		  case XK_Control_L: keyevent->keycode = 37; break;
		  case XK_Control_R: keyevent->keycode = 105; break;
		  case XK_Alt_L: keyevent->keycode = 64; break;
		  case XK_Alt_R: keyevent->keycode = 108; break;
		  case XK_Super_R: keyevent->keycode = 143; break;
		  case XK_Caps_Lock: keyevent->keycode = 66; break;
		  case XK_Num_Lock: keyevent->keycode = 77; break;

		  /* Extended keyboard navigation keys */
		  case XK_Home: keyevent->keycode = 110; break;
		  case XK_End: keyevent->keycode = 115; break;
		  case XK_Prior: keyevent->keycode = 112; break;
		  case XK_Next: keyevent->keycode = 117; break;
		  case XK_Delete: keyevent->keycode = 119; break;

		  /* Numeric keypad keys */
		  case XK_KP_Equal: keyevent->keycode = 125; break;
		  case XK_KP_Divide: keyevent->keycode = 106; break;
		  case XK_KP_Multiply: keyevent->keycode = 63; break;
		  case XK_KP_Subtract: keyevent->keycode = 82; break;
		  case XK_KP_Add: keyevent->keycode = 86; break;
		  case XK_KP_Enter: keyevent->keycode = 104; break;
		  case XK_KP_Decimal: keyevent->keycode = 91; break;
		  case XK_KP_0: keyevent->keycode = 90; break;
		  case XK_KP_1: keyevent->keycode = 87; break;
		  case XK_KP_2: keyevent->keycode = 88; break;
		  case XK_KP_3: keyevent->keycode = 89; break;
		  case XK_KP_4: keyevent->keycode = 83; break;
		  case XK_KP_5: keyevent->keycode = 84; break;
		  case XK_KP_6: keyevent->keycode = 85; break;
		  case XK_KP_7: keyevent->keycode = 79; break;
		  case XK_KP_8: keyevent->keycode = 80; break;
		  case XK_KP_9: keyevent->keycode = 81; break;


		  /* top row - function keys */
		  case XK_Escape: keyevent->keycode = 9; break;
		  case XK_F1: keyevent->keycode = 67; break;
		  case XK_F2: keyevent->keycode = 68; break;
		  case XK_F3: keyevent->keycode = 69; break;
		  case XK_F4: keyevent->keycode = 70; break;
		  case XK_F5: keyevent->keycode = 71; break;
		  case XK_F6: keyevent->keycode = 72; break;
		  case XK_F7: keyevent->keycode = 73; break;
		  case XK_F8: keyevent->keycode = 74; break;
		  case XK_F9: keyevent->keycode = 75; break;
		  case XK_F10: keyevent->keycode = 76; break;
		  case XK_F11: keyevent->keycode = 95; break;
		  case XK_F12: keyevent->keycode = 96; break;

		  /* Second row: numeric keys, 12345 */
		  case XK_grave: keyevent->keycode = 49; break;
		  case XK_1: keyevent->keycode = 10; break;
		  case XK_2: keyevent->keycode = 11; break;
		  case XK_3: keyevent->keycode = 12; break;
		  case XK_4: keyevent->keycode = 13; break;
		  case XK_5: keyevent->keycode = 14; break;
		  case XK_6: keyevent->keycode = 15; break;
		  case XK_7: keyevent->keycode = 16; break;
		  case XK_8: keyevent->keycode = 17; break;
		  case XK_9: keyevent->keycode = 18; break;
		  case XK_0: keyevent->keycode = 19; break;
		  case XK_minus: keyevent->keycode = 20; break;
		  case XK_equal: keyevent->keycode = 21; break;
		  case XK_BackSpace: keyevent->keycode = 22; break;

		  /* Third row: qwerty */
		  case XK_Tab: keyevent->keycode = 23; break;
		  case XK_q: keyevent->keycode = 24; break;
		  case XK_w: keyevent->keycode = 25; break;
		  case XK_e: keyevent->keycode = 26; break;
		  case XK_r: keyevent->keycode = 27; break;
		  case XK_t: keyevent->keycode = 28; break;
		  case XK_y: keyevent->keycode = 29; break;
		  case XK_u: keyevent->keycode = 30; break;
		  case XK_i: keyevent->keycode = 31; break;
		  case XK_o: keyevent->keycode = 32; break;
		  case XK_p: keyevent->keycode = 33; break;
		  case XK_bracketleft: keyevent->keycode = 34; break;
		  case XK_bracketright: keyevent->keycode = 35; break;
		  case XK_backslash: keyevent->keycode = 51; break;

		  /* Fourth row: asdf */
		  case XK_a: keyevent->keycode = 38; break;
		  case XK_s: keyevent->keycode = 39; break;
		  case XK_d: keyevent->keycode = 40; break;
		  case XK_f: keyevent->keycode = 41; break;
		  case XK_g: keyevent->keycode = 42; break;
		  case XK_h: keyevent->keycode = 43; break;
		  case XK_j: keyevent->keycode = 44; break;
		  case XK_k: keyevent->keycode = 45; break;
		  case XK_l: keyevent->keycode = 46; break;
		  case XK_semicolon: keyevent->keycode = 47; break;
		  case XK_apostrophe: keyevent->keycode = 48; break;
		  case XK_Return: keyevent->keycode = 36; break;

		  /* Fifth row: zxcv */
		  case XK_z: keyevent->keycode = 52; break;
		  case XK_x: keyevent->keycode = 53; break;
		  case XK_c: keyevent->keycode = 54; break;
		  case XK_v: keyevent->keycode = 55; break;
		  case XK_b: keyevent->keycode = 56; break;
		  case XK_n: keyevent->keycode = 57; break;
		  case XK_m: keyevent->keycode = 58; break;
		  case XK_comma: keyevent->keycode = 59; break;
		  case XK_period: keyevent->keycode = 60; break;
		  case XK_slash: keyevent->keycode = 61; break;

		  case XK_space: keyevent->keycode = 65; break;

		  /* Arrow keys */
		  case XK_Up: keyevent->keycode = 98; break;
		  case XK_Left: keyevent->keycode = 100; break;
		  case XK_Right: keyevent->keycode = 102; break;
		  case XK_Down: keyevent->keycode = 104; break;

		}
	}

	return r;
}

#ifdef DEBUG
KeyCode
XKeysymToKeycode(Display *display, KeySym keysym)
{
	KeyCode keycode;

	if (!hack_initialised)
		hack_init();

	keycode = real_XKeysymToKeycode(display, keysym);

	fprintf(fd, "XKeysymToKeycode: %d\n", keycode);
	fflush(fd);

	return keycode;
}
#endif