1 /*
2  * Copyright (c) 2020 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "star-platinum.h"
18 
19 #include <err.h>
20 #include <signal.h>
21 #include <stdarg.h>
22 #include <stdio.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 #include <X11/XKBlib.h>
27 #include <X11/Xutil.h>
28 
29 #ifndef __OpenBSD__
30 # define pledge(a, b) 0
31 #endif
32 
33 extern FILE *yyin;
34 char *fname;
35 
36 extern int yylineno;
37 int yyparse(void);
38 
39 struct group *config;
40 int goterror = 0;
41 
42 Display *d;
43 
44 int ignored_modifiers[] = {
45 	0,			/* no modifiers */
46 	LockMask,		/* caps lock */
47 	Mod2Mask,		/* num lock */
48 	Mod3Mask,		/* scroll lock */
49 	Mod5Mask,		/* ? */
50 };
51 
52 #define IGNORE_MODIFIERS (LockMask | Mod2Mask | Mod3Mask | Mod5Mask)
53 
54 __attribute__((__format__ (__printf__, 1, 2)))
55 void
56 yyerror(const char *fmt, ...)
57 {
58 	va_list ap;
59 	size_t l;
60 
61 	va_start(ap, fmt);
62 
63 	goterror = 1;
64 	fprintf(stderr, "%s:%d ", fname, yylineno);
65 	vfprintf(stderr, fmt, ap);
66 
67 	l = strlen(fmt);
68 	if (l > 0 && fmt[l-1] != '\n')
69 		fprintf(stderr, "\n");
70 
71 	va_end(ap);
72 }
73 
74 char *
75 find_config()
76 {
77 	char *home, *xdg, *t;
78 	int free_xdg = 0;
79 
80 	home = getenv("HOME");
81 	xdg = getenv("XDG_CONFIG_HOME");
82 
83 	if (home == NULL && xdg == NULL)
84 		return NULL;
85 
86 	/* file in home directory >>>>>> XDG shit */
87 	if (home != NULL) {
88 		if (asprintf(&t, "%s/.star-platinum.conf", home) == -1)
89 			return NULL;
90 		if (access(t, R_OK) == 0)
91 			return t;
92 
93 		free(t);
94 		/* continue to search */
95 	}
96 
97 	/* sanitize XDG_CONFIG_HOME */
98 	if (xdg == NULL) {
99 		free_xdg = 1;
100 		if (asprintf(&xdg, "%s/.config", home) == -1)
101 			return NULL;
102 	}
103 
104 	if (asprintf(&t, "%s/star-platinum.conf", xdg) == -1)
105 		goto err;
106 
107 	if (access(t, R_OK) == 0)
108 		return t;
109 	free(t);
110 
111 err:
112 	if (free_xdg)
113 		free(xdg);
114 
115 	return NULL;
116 }
117 
118 int
119 main(int argc, char **argv)
120 {
121 	int status = 0, dump_config = 0, conftest = 0, ch;
122 	struct group *g;
123 	struct rule *r;
124 	XEvent e;
125 	Window root;
126 
127 	signal(SIGCHLD, SIG_IGN); /* don't allow zombies */
128 
129 	fname = NULL;
130 	while ((ch = getopt(argc, argv, "c:dn")) != -1) {
131 		switch (ch) {
132 		case 'c':
133 			free(fname);
134 			if ((fname = strdup(optarg)) == NULL)
135 				err(1, "strdup");
136 			break;
137 
138 		case 'd':
139 			dump_config = 1;
140 			break;
141 
142 		case 'n':
143 			conftest = 1;
144 			break;
145 
146 		default:
147 			fprintf(stderr, "USAGE: %s [-dn] [-c conf]\n", *argv);
148 			return 1;
149 		}
150 	}
151 
152 	if (fname == NULL) {
153 		if ((fname = find_config()) == NULL)
154 			errx(1, "can't find a configuration file");
155 	}
156 
157 	if ((yyin = fopen(fname, "r")) == NULL)
158 		err(1, "cannot open %s", fname);
159 	yyparse();
160 	fclose(yyin);
161 
162 	free(fname);
163 	fname = NULL;
164 
165 	if (goterror)
166 		return 1;
167 
168 	if (dump_config)
169 		printgroup(config);
170 
171 	if (conftest) {
172 		recfree_group(config);
173 		return 0;
174 	}
175 
176 	if ((d = XOpenDisplay(NULL)) == NULL) {
177 		recfree_group(config);
178 		return 1;
179 	}
180 
181 	XSetErrorHandler(&error_handler);
182 
183 	root = DefaultRootWindow(d);
184 
185 	/* grab all the keys */
186 	for (g = config; g != NULL; g = g->next)
187 		for (r = g->rules; r != NULL; r = r->next)
188 			grabkey(r->key);
189 
190 	XSelectInput(d, root, KeyPressMask);
191 	XFlush(d);
192 
193 	pledge("stdio proc exec", NULL);
194 
195 	while (1) {
196 		XNextEvent(d, &e);
197 		switch (e.type) {
198 		case KeyRelease:
199 		case KeyPress:
200 			process_event(config, (XKeyEvent*)&e);
201 			break;
202 
203 		default:
204 			printf("Unknown event %d\n", e.type);
205 			break;
206 		}
207 	}
208 
209 	XCloseDisplay(d);
210 	recfree_group(config);
211 	return status;
212 }
213 
214 
215 /* xlib */
216 
217 int
218 error_handler(Display *d, XErrorEvent *e)
219 {
220 	fprintf(stderr, "Xlib error %d\n", e->type);
221 	return 1;
222 }
223 
224 /* TODO: it should grab ALL POSSIBLE COMBINATIONS of `ignored_modifiers`! */
225 void
226 grabkey(struct key k)
227 {
228 	static size_t len = sizeof(ignored_modifiers)/sizeof(int);
229 	size_t i;
230 	Window root;
231 
232 	root = DefaultRootWindow(d);
233 
234 	/* printf("Grabbing "); printkey(k); printf("\n"); */
235 	for (i = 0; i < len; ++i) {
236 		XGrabKey(d, XKeysymToKeycode(d, k.key),
237 		    k.modifier | ignored_modifiers[i],
238 		    root, False, GrabModeAsync, GrabModeAsync);
239 	}
240 }
241 
242 KeySym
243 keycode_to_keysym(unsigned int kc)
244 {
245 	/* group 0 (?). shift level is 0 because we don't want it*/
246 	return XkbKeycodeToKeysym(d, kc, 0, 0);
247 }
248 
249 Window
250 focused_window()
251 {
252 	Window w;
253 	int revert_to;
254 
255 	/* one can use (at least) three way to obtain the current
256 	 * focused window using xlib:
257 	 *
258 	 * - XQueryTree : you traverse tre tree until you find the
259 	 *     window
260 	 *
261 	 * - looking at _NET_ACTIVE_WINDOW in the root window, but
262 	 *    depedns on the window manager to set it
263 	 *
264 	 * - using XGetInputFocus
265 	 *
266 	 * I don't know the pro/cons of these, but XGetInputFocus
267 	 * seems the easiest.
268 	 */
269 	XGetInputFocus(d, &w, &revert_to);
270 	return w;
271 }
272 
273 void
274 send_fake(Window w, struct key k, int pressed)
275 {
276 	XKeyEvent e;
277 
278 	e.type = pressed ? KeyPress : KeyRelease;
279 
280 	e.display = d;
281 	e.window = w;
282 	e.root = DefaultRootWindow(d);
283 	e.subwindow = None;
284 	e.time = CurrentTime;
285 
286 	/* TODO: fix these */
287 	e.x = 1;
288 	e.y = 1;
289 	e.x_root = 1;
290 	e.y_root = 1;
291 
292 	e.same_screen = True;
293 	e.keycode = XKeysymToKeycode(d, k.key);
294 	e.state = k.modifier;
295 
296 	XSendEvent(d, w, True, KeyPressMask, (XEvent*)&e);
297 	XFlush(d);
298 }
299 
300 int
301 window_match_class(Window w, const char *class)
302 {
303 	XClassHint ch;
304 	int matched;
305 
306 	if (!XGetClassHint(d, w, &ch)) {
307 		fprintf(stderr, "XGetClassHint failed\n");
308 		return 0;
309 	}
310 
311 	matched = !strcmp(ch.res_class, class);
312 
313 	XFree(ch.res_name);
314 	XFree(ch.res_class);
315 
316 	return matched;
317 }
318 
319 
320 /* action */
321 
322 void
323 do_action(struct action a, Window focused, int pressed)
324 {
325 	switch (a.type) {
326 	case AFAKE:
327 		send_fake(focused, a.send_key, pressed);
328 		break;
329 
330 	case ASPECIAL:
331 		switch (a.special) {
332 		case ATOGGLE:
333 		case AACTIVATE:
334 		case ADEACTIVATE:
335 			printf("TODO\n");
336 			break;
337 
338 		case AIGNORE:
339 			break;
340 
341 		default:
342 			/* unreachable */
343 			abort();
344 		}
345 		break;
346 
347 	case AEXEC: {
348 		pid_t p;
349 		const char *sh;
350 
351 		switch (p = fork()) {
352 		case -1:
353 			err(1, "fork");
354 
355 		case 0:
356 			if ((sh = getenv("SHELL")) == NULL)
357 				sh = "/bin/sh";
358 			printf("before exec'ing %s -c '%s'\n", sh, a.str);
359 			execlp(sh, sh, "-c", a.str, NULL);
360 			err(1, "execlp");
361 		}
362 
363 		break;
364 	}
365 
366 	default:
367 		/* unreachable */
368 		abort();
369 	}
370 }
371 
372 void
373 free_action(struct action a)
374 {
375 	if (a.type == AEXEC)
376 		free(a.str);
377 }
378 
379 
380 /* match */
381 
382 struct match *
383 new_match(int prop, char *s)
384 {
385 	struct match *m;
386 
387 	if ((m = calloc(1, sizeof(*m))) == NULL)
388 		err(1, "calloc");
389 	m->prop = prop;
390 	m->str = s;
391 	return m;
392 }
393 
394 void
395 recfree_match(struct match *m)
396 {
397 	struct match *mt;
398 
399 	if (m == NULL)
400 		return;
401 
402 	mt = m->next;
403 	free(m->str);
404 	free(m);
405 	recfree_match(mt);
406 }
407 
408 int
409 match_window(struct match *m, Window w)
410 {
411 	switch (m->prop) {
412 	case MANY:
413 		return 1;
414 
415 	case MCLASS:
416 		return window_match_class(w, m->str);
417 		break;
418 
419 	default:
420 		/* unreachable */
421 		abort();
422 	}
423 }
424 
425 
426 /* rule */
427 
428 struct rule *
429 new_rule(struct key k, struct action a)
430 {
431 	struct rule *r;
432 
433 	if ((r = calloc(1, sizeof(*r))) == NULL)
434 		err(1, "calloc");
435 	memcpy(&r->key, &k, sizeof(k));
436 	memcpy(&r->action, &a, sizeof(a));
437 	return r;
438 }
439 
440 void
441 recfree_rule(struct rule *r)
442 {
443 	struct rule *rt;
444 
445 	if (r == NULL)
446 		return;
447 
448 	rt = r->next;
449 	free(r);
450 	recfree_rule(rt);
451 }
452 
453 int
454 rule_matched(struct rule *r, struct key k)
455 {
456 	unsigned int m;
457 
458 	m = k.modifier;
459 	m &= ~IGNORE_MODIFIERS; /* clear ignored modifiers */
460 
461 	return r->key.modifier == m
462 		&& r->key.key == k.key;
463 }
464 
465 
466 /* group */
467 
468 struct group *
469 new_group(struct match *matches, struct rule *rules)
470 {
471 	struct group *g;
472 
473 	if ((g = calloc(1, sizeof(*g))) == NULL)
474 		err(1, "calloc");
475 	g->matches = matches;
476 	g->rules = rules;
477 	return g;
478 }
479 
480 void
481 recfree_group(struct group *g)
482 {
483 	struct group *gt;
484 
485 	if (g == NULL)
486 		return;
487 
488 	gt = g->next;
489 	recfree_match(g->matches);
490 	recfree_rule(g->rules);
491 	free(g);
492 	recfree_group(gt);
493 }
494 
495 void
496 process_event(struct group *g, XKeyEvent *e)
497 {
498 	Window focused;
499 	struct rule *r;
500 	struct key pressed = {
501 		.modifier = e->state,
502 		.key = keycode_to_keysym(e->keycode),
503 	};
504 
505 	focused = focused_window();
506 
507 	for (; g != NULL; g = g->next) {
508 		if (!group_match(g, focused))
509 			continue;
510 
511 		for (r = g->rules; r != NULL; r = r->next) {
512 			if (rule_matched(r, pressed)) {
513 				do_action(r->action, focused, e->type == KeyPress);
514 				return;
515 			}
516 		}
517 	}
518 
519 	send_fake(focused, pressed, e->type == KeyPress);
520 }
521 
522 int
523 group_match(struct group *g, Window w)
524 {
525 	struct match *m;
526 
527 	for (m = g->matches; m != NULL; m = m->next)
528 		if (match_window(m, w))
529 			return 1;
530 	return 0;
531 }
532 
533 
534 /* debug/dump stuff */
535 
536 void
537 printkey(struct key k)
538 {
539 	if (k.modifier & ControlMask)
540 		printf("C-");
541 	if (k.modifier & ShiftMask)
542 		printf("S-");
543 	if (k.modifier & Mod1Mask)
544 		printf("M-");
545 	if (k.modifier & Mod4Mask)
546 		printf("s-");
547 
548 	printf("%s", XKeysymToString(k.key));
549 }
550 
551 void
552 printaction(struct action a)
553 {
554 	switch (a.type) {
555 	case ASPECIAL:
556 		switch (a.special) {
557 		case ATOGGLE: printf("toggle"); break;
558 		case AACTIVATE: printf("activate"); break;
559 		case ADEACTIVATE: printf("deactivate"); break;
560 		case AIGNORE: printf("ignore"); break;
561 		default: abort(); /* unreachable */
562 		}
563 		break;
564 
565 	case AFAKE:
566 		printf("send key ");
567 		printkey(a.send_key);
568 		break;
569 
570 	case AEXEC:
571 		printf("exec %s", a.str);
572 		break;
573 
574 	default:
575 		/* unreachable */
576 		abort();
577 	}
578 }
579 
580 void
581 printmatch(struct match *m)
582 {
583 	if (m == NULL) {
584 		printf("(null)");
585 		return;
586 	}
587 	printf("match ");
588 	switch (m->prop) {
589 	case MANY:
590 		printf("all");
591 		break;
592 	case MCLASS:
593 		printf("class %s", m->str);
594 		break;
595 	default:
596 		/* unreachable */
597 		abort();
598 	}
599 
600 	if (m->next == NULL)
601 		printf("\n");
602 	else {
603 		printf(" ; ");
604 		printmatch(m->next);
605 	}
606 }
607 
608 void
609 printrule(struct rule *r)
610 {
611 	if (r == NULL) {
612 		printf("(null)");
613 		return;
614 	}
615 	printf("on ");
616 	printkey(r->key);
617 	printf(" do ");
618 	printaction(r->action);
619 	printf("\n");
620 
621 	if (r->next != NULL)
622 		printrule(r->next);
623 }
624 
625 void
626 printgroup(struct group *g)
627 {
628 	if (g == NULL) {
629 		printf("(null)");
630 		return;
631 	}
632 	printmatch(g->matches);
633 	printf("\n");
634 	printrule(g->rules);
635 	printf("\n\n");
636 
637 	if (g->next != NULL)
638 		printgroup(g->next);
639 }