xref: /freebsd/sys/dev/evdev/cdev.c (revision 0bf56da32d83fbd3b5db8d6c72cd1e7cc26fbc66)
1 /*-
2  * Copyright (c) 2014 Jakub Wojciech Klama <jceel@FreeBSD.org>
3  * Copyright (c) 2015-2016 Vladimir Kondratyev <wulf@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include "opt_evdev.h"
31 
32 #include <sys/param.h>
33 #include <sys/bitstring.h>
34 #include <sys/conf.h>
35 #include <sys/filio.h>
36 #include <sys/fcntl.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/poll.h>
40 #include <sys/proc.h>
41 #include <sys/selinfo.h>
42 #include <sys/systm.h>
43 #include <sys/time.h>
44 #include <sys/uio.h>
45 
46 #include <dev/evdev/evdev.h>
47 #include <dev/evdev/evdev_private.h>
48 #include <dev/evdev/input.h>
49 
50 #ifdef COMPAT_FREEBSD32
51 #include <sys/mount.h>
52 #include <sys/sysent.h>
53 #include <compat/freebsd32/freebsd32.h>
54 struct input_event32 {
55 	struct timeval32	time;
56 	uint16_t		type;
57 	uint16_t		code;
58 	int32_t			value;
59 };
60 #endif
61 
62 #ifdef EVDEV_DEBUG
63 #define	debugf(client, fmt, args...)	printf("evdev cdev: "fmt"\n", ##args)
64 #else
65 #define	debugf(client, fmt, args...)
66 #endif
67 
68 #define	DEF_RING_REPORTS	8
69 
70 static d_open_t		evdev_open;
71 static d_read_t		evdev_read;
72 static d_write_t	evdev_write;
73 static d_ioctl_t	evdev_ioctl;
74 static d_poll_t		evdev_poll;
75 static d_kqfilter_t	evdev_kqfilter;
76 
77 static int evdev_kqread(struct knote *kn, long hint);
78 static void evdev_kqdetach(struct knote *kn);
79 static void evdev_dtor(void *);
80 static int evdev_ioctl_eviocgbit(struct evdev_dev *, int, int, caddr_t);
81 static void evdev_client_filter_queue(struct evdev_client *, uint16_t);
82 
83 static struct cdevsw evdev_cdevsw = {
84 	.d_version = D_VERSION,
85 	.d_open = evdev_open,
86 	.d_read = evdev_read,
87 	.d_write = evdev_write,
88 	.d_ioctl = evdev_ioctl,
89 	.d_poll = evdev_poll,
90 	.d_kqfilter = evdev_kqfilter,
91 	.d_name = "evdev",
92 };
93 
94 static struct filterops evdev_cdev_filterops = {
95 	.f_isfd = 1,
96 	.f_attach = NULL,
97 	.f_detach = evdev_kqdetach,
98 	.f_event = evdev_kqread,
99 };
100 
101 static int
102 evdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
103 {
104 	struct evdev_dev *evdev = dev->si_drv1;
105 	struct evdev_client *client;
106 	size_t buffer_size;
107 	int ret;
108 
109 	if (evdev == NULL)
110 		return (ENODEV);
111 
112 	/* Initialize client structure */
113 	buffer_size = evdev->ev_report_size * DEF_RING_REPORTS;
114 	client = malloc(offsetof(struct evdev_client, ec_buffer) +
115 	    sizeof(struct input_event) * buffer_size,
116 	    M_EVDEV, M_WAITOK | M_ZERO);
117 
118 	/* Initialize ring buffer */
119 	client->ec_buffer_size = buffer_size;
120 	client->ec_buffer_head = 0;
121 	client->ec_buffer_tail = 0;
122 	client->ec_buffer_ready = 0;
123 
124 	client->ec_evdev = evdev;
125 	mtx_init(&client->ec_buffer_mtx, "evclient", "evdev", MTX_DEF);
126 	knlist_init_mtx(&client->ec_selp.si_note, &client->ec_buffer_mtx);
127 
128 	/* Avoid race with evdev_unregister */
129 	EVDEV_LOCK(evdev);
130 	if (dev->si_drv1 == NULL)
131 		ret = ENODEV;
132 	else
133 		ret = evdev_register_client(evdev, client);
134 
135 	if (ret != 0)
136 		evdev_revoke_client(client);
137 	/*
138 	 * Unlock evdev here because non-sleepable lock held
139 	 * while calling devfs_set_cdevpriv upsets WITNESS
140 	 */
141 	EVDEV_UNLOCK(evdev);
142 
143 	if (!ret)
144 		ret = devfs_set_cdevpriv(client, evdev_dtor);
145 
146 	if (ret != 0) {
147 		debugf(client, "cannot register evdev client");
148 		evdev_dtor(client);
149 	}
150 
151 	return (ret);
152 }
153 
154 static void
155 evdev_dtor(void *data)
156 {
157 	struct evdev_client *client = (struct evdev_client *)data;
158 
159 	EVDEV_LOCK(client->ec_evdev);
160 	if (!client->ec_revoked)
161 		evdev_dispose_client(client->ec_evdev, client);
162 	EVDEV_UNLOCK(client->ec_evdev);
163 
164 	knlist_clear(&client->ec_selp.si_note, 0);
165 	seldrain(&client->ec_selp);
166 	knlist_destroy(&client->ec_selp.si_note);
167 	funsetown(&client->ec_sigio);
168 	mtx_destroy(&client->ec_buffer_mtx);
169 	free(client, M_EVDEV);
170 }
171 
172 static int
173 evdev_read(struct cdev *dev, struct uio *uio, int ioflag)
174 {
175 	struct evdev_client *client;
176 	union {
177 		struct input_event t;
178 #ifdef COMPAT_FREEBSD32
179 		struct input_event32 t32;
180 #endif
181 	} event;
182 	struct input_event *head;
183 	size_t evsize;
184 	int ret = 0;
185 	int remaining;
186 
187 	ret = devfs_get_cdevpriv((void **)&client);
188 	if (ret != 0)
189 		return (ret);
190 
191 	debugf(client, "read %zd bytes by thread %d", uio->uio_resid,
192 	    uio->uio_td->td_tid);
193 
194 	if (client->ec_revoked)
195 		return (ENODEV);
196 
197 #ifdef COMPAT_FREEBSD32
198 	if (SV_CURPROC_FLAG(SV_ILP32))
199 		evsize = sizeof(struct input_event32);
200 	else
201 #endif
202 		evsize = sizeof(struct input_event);
203 
204 	/* Zero-sized reads are allowed for error checking */
205 	if (uio->uio_resid != 0 && uio->uio_resid < evsize)
206 		return (EINVAL);
207 
208 	remaining = uio->uio_resid / evsize;
209 
210 	EVDEV_CLIENT_LOCKQ(client);
211 
212 	if (EVDEV_CLIENT_EMPTYQ(client)) {
213 		if (ioflag & O_NONBLOCK)
214 			ret = EWOULDBLOCK;
215 		else {
216 			if (remaining != 0) {
217 				client->ec_blocked = true;
218 				ret = mtx_sleep(client, &client->ec_buffer_mtx,
219 				    PCATCH, "evread", 0);
220 				if (ret == 0 && client->ec_revoked)
221 					ret = ENODEV;
222 			}
223 		}
224 	}
225 
226 	while (ret == 0 && !EVDEV_CLIENT_EMPTYQ(client) && remaining > 0) {
227 		head = client->ec_buffer + client->ec_buffer_head;
228 #ifdef COMPAT_FREEBSD32
229 		if (SV_CURPROC_FLAG(SV_ILP32)) {
230 			bzero(&event.t32, sizeof(struct input_event32));
231 			TV_CP(*head, event.t32, time);
232 			CP(*head, event.t32, type);
233 			CP(*head, event.t32, code);
234 			CP(*head, event.t32, value);
235 		} else
236 #endif
237 			bcopy(head, &event.t, evsize);
238 
239 		client->ec_buffer_head =
240 		    (client->ec_buffer_head + 1) % client->ec_buffer_size;
241 		remaining--;
242 
243 		EVDEV_CLIENT_UNLOCKQ(client);
244 		ret = uiomove(&event, evsize, uio);
245 		EVDEV_CLIENT_LOCKQ(client);
246 	}
247 
248 	EVDEV_CLIENT_UNLOCKQ(client);
249 
250 	return (ret);
251 }
252 
253 static int
254 evdev_write(struct cdev *dev, struct uio *uio, int ioflag)
255 {
256 	struct evdev_dev *evdev = dev->si_drv1;
257 	struct evdev_client *client;
258 	union {
259 		struct input_event t;
260 #ifdef COMPAT_FREEBSD32
261 		struct input_event32 t32;
262 #endif
263 	} event;
264 	size_t evsize;
265 	int ret = 0;
266 
267 	ret = devfs_get_cdevpriv((void **)&client);
268 	if (ret != 0)
269 		return (ret);
270 
271 	debugf(client, "write %zd bytes by thread %d", uio->uio_resid,
272 	    uio->uio_td->td_tid);
273 
274 	if (client->ec_revoked || evdev == NULL)
275 		return (ENODEV);
276 
277 #ifdef COMPAT_FREEBSD32
278 	if (SV_CURPROC_FLAG(SV_ILP32))
279 		evsize = sizeof(struct input_event32);
280 	else
281 #endif
282 		evsize = sizeof(struct input_event);
283 
284 	if (uio->uio_resid % evsize != 0) {
285 		debugf(client, "write size not multiple of input_event size");
286 		return (EINVAL);
287 	}
288 
289 	while (uio->uio_resid > 0 && ret == 0) {
290 		ret = uiomove(&event, evsize, uio);
291 		if (ret == 0) {
292 #ifdef COMPAT_FREEBSD32
293 			if (SV_CURPROC_FLAG(SV_ILP32))
294 				ret = evdev_inject_event(evdev, event.t32.type,
295 				    event.t32.code, event.t32.value);
296 			else
297 #endif
298 				ret = evdev_inject_event(evdev, event.t.type,
299 				    event.t.code, event.t.value);
300 		}
301 	}
302 
303 	return (ret);
304 }
305 
306 static int
307 evdev_poll(struct cdev *dev, int events, struct thread *td)
308 {
309 	struct evdev_client *client;
310 	int ret;
311 	int revents = 0;
312 
313 	ret = devfs_get_cdevpriv((void **)&client);
314 	if (ret != 0)
315 		return (POLLNVAL);
316 
317 	debugf(client, "poll by thread %d", td->td_tid);
318 
319 	if (client->ec_revoked)
320 		return (POLLHUP);
321 
322 	if (events & (POLLIN | POLLRDNORM)) {
323 		EVDEV_CLIENT_LOCKQ(client);
324 		if (!EVDEV_CLIENT_EMPTYQ(client))
325 			revents = events & (POLLIN | POLLRDNORM);
326 		else {
327 			client->ec_selected = true;
328 			selrecord(td, &client->ec_selp);
329 		}
330 		EVDEV_CLIENT_UNLOCKQ(client);
331 	}
332 
333 	return (revents);
334 }
335 
336 static int
337 evdev_kqfilter(struct cdev *dev, struct knote *kn)
338 {
339 	struct evdev_client *client;
340 	int ret;
341 
342 	ret = devfs_get_cdevpriv((void **)&client);
343 	if (ret != 0)
344 		return (ret);
345 
346 	if (client->ec_revoked)
347 		return (ENODEV);
348 
349 	switch(kn->kn_filter) {
350 	case EVFILT_READ:
351 		kn->kn_fop = &evdev_cdev_filterops;
352 		break;
353 	default:
354 		return(EINVAL);
355 	}
356 	kn->kn_hook = (caddr_t)client;
357 
358 	knlist_add(&client->ec_selp.si_note, kn, 0);
359 	return (0);
360 }
361 
362 static int
363 evdev_kqread(struct knote *kn, long hint)
364 {
365 	struct evdev_client *client;
366 	int ret;
367 
368 	client = (struct evdev_client *)kn->kn_hook;
369 
370 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
371 
372 	if (client->ec_revoked) {
373 		kn->kn_flags |= EV_EOF;
374 		ret = 1;
375 	} else {
376 		kn->kn_data = EVDEV_CLIENT_SIZEQ(client) *
377 		    sizeof(struct input_event);
378 		ret = !EVDEV_CLIENT_EMPTYQ(client);
379 	}
380 	return (ret);
381 }
382 
383 static void
384 evdev_kqdetach(struct knote *kn)
385 {
386 	struct evdev_client *client;
387 
388 	client = (struct evdev_client *)kn->kn_hook;
389 	knlist_remove(&client->ec_selp.si_note, kn, 0);
390 }
391 
392 static int
393 evdev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
394     struct thread *td)
395 {
396 	struct evdev_dev *evdev = dev->si_drv1;
397 	struct evdev_client *client;
398 	struct input_keymap_entry *ke;
399 	int ret, len, limit, type_num;
400 	uint32_t code;
401 	size_t nvalues;
402 
403 	ret = devfs_get_cdevpriv((void **)&client);
404 	if (ret != 0)
405 		return (ret);
406 
407 	if (client->ec_revoked || evdev == NULL)
408 		return (ENODEV);
409 
410 	/*
411 	 * Fix evdev state corrupted with discarding of kdb events.
412 	 * EVIOCGKEY and EVIOCGLED ioctls can suffer from this.
413 	 */
414 	if (evdev->ev_kdb_active) {
415 		EVDEV_LOCK(evdev);
416 		if (evdev->ev_kdb_active) {
417 			evdev->ev_kdb_active = false;
418 			evdev_restore_after_kdb(evdev);
419 		}
420 		EVDEV_UNLOCK(evdev);
421 	}
422 
423 	/* file I/O ioctl handling */
424 	switch (cmd) {
425 	case FIOSETOWN:
426 		return (fsetown(*(int *)data, &client->ec_sigio));
427 
428 	case FIOGETOWN:
429 		*(int *)data = fgetown(&client->ec_sigio);
430 		return (0);
431 
432 	case FIONBIO:
433 		return (0);
434 
435 	case FIOASYNC:
436 		if (*(int *)data)
437 			client->ec_async = true;
438 		else
439 			client->ec_async = false;
440 
441 		return (0);
442 
443 	case FIONREAD:
444 		EVDEV_CLIENT_LOCKQ(client);
445 		*(int *)data =
446 		    EVDEV_CLIENT_SIZEQ(client) * sizeof(struct input_event);
447 		EVDEV_CLIENT_UNLOCKQ(client);
448 		return (0);
449 	}
450 
451 	len = IOCPARM_LEN(cmd);
452 	debugf(client, "ioctl called: cmd=0x%08lx, data=%p", cmd, data);
453 
454 	/* evdev fixed-length ioctls handling */
455 	switch (cmd) {
456 	case EVIOCGVERSION:
457 		*(int *)data = EV_VERSION;
458 		return (0);
459 
460 	case EVIOCGID:
461 		debugf(client, "EVIOCGID: bus=%d vendor=0x%04x product=0x%04x",
462 		    evdev->ev_id.bustype, evdev->ev_id.vendor,
463 		    evdev->ev_id.product);
464 		memcpy(data, &evdev->ev_id, sizeof(struct input_id));
465 		return (0);
466 
467 	case EVIOCGREP:
468 		if (!evdev_event_supported(evdev, EV_REP))
469 			return (ENOTSUP);
470 
471 		memcpy(data, evdev->ev_rep, sizeof(evdev->ev_rep));
472 		return (0);
473 
474 	case EVIOCSREP:
475 		if (!evdev_event_supported(evdev, EV_REP))
476 			return (ENOTSUP);
477 
478 		evdev_inject_event(evdev, EV_REP, REP_DELAY, ((int *)data)[0]);
479 		evdev_inject_event(evdev, EV_REP, REP_PERIOD,
480 		    ((int *)data)[1]);
481 		return (0);
482 
483 	case EVIOCGKEYCODE:
484 		/* Fake unsupported ioctl */
485 		return (0);
486 
487 	case EVIOCGKEYCODE_V2:
488 		if (evdev->ev_methods == NULL ||
489 		    evdev->ev_methods->ev_get_keycode == NULL)
490 			return (ENOTSUP);
491 
492 		ke = (struct input_keymap_entry *)data;
493 		evdev->ev_methods->ev_get_keycode(evdev, ke);
494 		return (0);
495 
496 	case EVIOCSKEYCODE:
497 		/* Fake unsupported ioctl */
498 		return (0);
499 
500 	case EVIOCSKEYCODE_V2:
501 		if (evdev->ev_methods == NULL ||
502 		    evdev->ev_methods->ev_set_keycode == NULL)
503 			return (ENOTSUP);
504 
505 		ke = (struct input_keymap_entry *)data;
506 		evdev->ev_methods->ev_set_keycode(evdev, ke);
507 		return (0);
508 
509 	case EVIOCGABS(0) ... EVIOCGABS(ABS_MAX):
510 		if (evdev->ev_absinfo == NULL)
511 			return (EINVAL);
512 
513 		memcpy(data, &evdev->ev_absinfo[cmd - EVIOCGABS(0)],
514 		    sizeof(struct input_absinfo));
515 		return (0);
516 
517 	case EVIOCSABS(0) ... EVIOCSABS(ABS_MAX):
518 		if (evdev->ev_absinfo == NULL)
519 			return (EINVAL);
520 
521 		code = cmd - EVIOCSABS(0);
522 		/* mt-slot number can not be changed */
523 		if (code == ABS_MT_SLOT)
524 			return (EINVAL);
525 
526 		EVDEV_LOCK(evdev);
527 		evdev_set_absinfo(evdev, code, (struct input_absinfo *)data);
528 		EVDEV_UNLOCK(evdev);
529 		return (0);
530 
531 	case EVIOCSFF:
532 	case EVIOCRMFF:
533 	case EVIOCGEFFECTS:
534 		/* Fake unsupported ioctls */
535 		return (0);
536 
537 	case EVIOCGRAB:
538 		EVDEV_LOCK(evdev);
539 		if (*(int *)data)
540 			ret = evdev_grab_client(evdev, client);
541 		else
542 			ret = evdev_release_client(evdev, client);
543 		EVDEV_UNLOCK(evdev);
544 		return (ret);
545 
546 	case EVIOCREVOKE:
547 		if (*(int *)data != 0)
548 			return (EINVAL);
549 
550 		EVDEV_LOCK(evdev);
551 		if (dev->si_drv1 != NULL && !client->ec_revoked) {
552 			evdev_dispose_client(evdev, client);
553 			evdev_revoke_client(client);
554 		}
555 		EVDEV_UNLOCK(evdev);
556 		return (0);
557 
558 	case EVIOCSCLOCKID:
559 		switch (*(int *)data) {
560 		case CLOCK_REALTIME:
561 			client->ec_clock_id = EV_CLOCK_REALTIME;
562 			return (0);
563 		case CLOCK_MONOTONIC:
564 			client->ec_clock_id = EV_CLOCK_MONOTONIC;
565 			return (0);
566 		default:
567 			return (EINVAL);
568 		}
569 	}
570 
571 	/* evdev variable-length ioctls handling */
572 	switch (IOCBASECMD(cmd)) {
573 	case EVIOCGNAME(0):
574 		strlcpy(data, evdev->ev_name, len);
575 		return (0);
576 
577 	case EVIOCGPHYS(0):
578 		if (evdev->ev_shortname[0] == 0)
579 			return (ENOENT);
580 
581 		strlcpy(data, evdev->ev_shortname, len);
582 		return (0);
583 
584 	case EVIOCGUNIQ(0):
585 		if (evdev->ev_serial[0] == 0)
586 			return (ENOENT);
587 
588 		strlcpy(data, evdev->ev_serial, len);
589 		return (0);
590 
591 	case EVIOCGPROP(0):
592 		limit = MIN(len, bitstr_size(INPUT_PROP_CNT));
593 		memcpy(data, evdev->ev_prop_flags, limit);
594 		return (0);
595 
596 	case EVIOCGMTSLOTS(0):
597 		if (evdev->ev_mt == NULL)
598 			return (EINVAL);
599 		if (len < sizeof(uint32_t))
600 			return (EINVAL);
601 		code = *(uint32_t *)data;
602 		if (!ABS_IS_MT(code))
603 			return (EINVAL);
604 
605 		nvalues =
606 		    MIN(len / sizeof(int32_t) - 1, MAXIMAL_MT_SLOT(evdev) + 1);
607 		for (int i = 0; i < nvalues; i++)
608 			((int32_t *)data)[i + 1] =
609 			    evdev_get_mt_value(evdev, i, code);
610 		return (0);
611 
612 	case EVIOCGKEY(0):
613 		limit = MIN(len, bitstr_size(KEY_CNT));
614 		EVDEV_LOCK(evdev);
615 		evdev_client_filter_queue(client, EV_KEY);
616 		memcpy(data, evdev->ev_key_states, limit);
617 		EVDEV_UNLOCK(evdev);
618 		return (0);
619 
620 	case EVIOCGLED(0):
621 		limit = MIN(len, bitstr_size(LED_CNT));
622 		EVDEV_LOCK(evdev);
623 		evdev_client_filter_queue(client, EV_LED);
624 		memcpy(data, evdev->ev_led_states, limit);
625 		EVDEV_UNLOCK(evdev);
626 		return (0);
627 
628 	case EVIOCGSND(0):
629 		limit = MIN(len, bitstr_size(SND_CNT));
630 		EVDEV_LOCK(evdev);
631 		evdev_client_filter_queue(client, EV_SND);
632 		memcpy(data, evdev->ev_snd_states, limit);
633 		EVDEV_UNLOCK(evdev);
634 		return (0);
635 
636 	case EVIOCGSW(0):
637 		limit = MIN(len, bitstr_size(SW_CNT));
638 		EVDEV_LOCK(evdev);
639 		evdev_client_filter_queue(client, EV_SW);
640 		memcpy(data, evdev->ev_sw_states, limit);
641 		EVDEV_UNLOCK(evdev);
642 		return (0);
643 
644 	case EVIOCGBIT(0, 0) ... EVIOCGBIT(EV_MAX, 0):
645 		type_num = IOCBASECMD(cmd) - EVIOCGBIT(0, 0);
646 		debugf(client, "EVIOCGBIT(%d): data=%p, len=%d", type_num,
647 		    data, len);
648 		return (evdev_ioctl_eviocgbit(evdev, type_num, len, data));
649 	}
650 
651 	return (EINVAL);
652 }
653 
654 static int
655 evdev_ioctl_eviocgbit(struct evdev_dev *evdev, int type, int len, caddr_t data)
656 {
657 	unsigned long *bitmap;
658 	int limit;
659 
660 	switch (type) {
661 	case 0:
662 		bitmap = evdev->ev_type_flags;
663 		limit = EV_CNT;
664 		break;
665 	case EV_KEY:
666 		bitmap = evdev->ev_key_flags;
667 		limit = KEY_CNT;
668 		break;
669 	case EV_REL:
670 		bitmap = evdev->ev_rel_flags;
671 		limit = REL_CNT;
672 		break;
673 	case EV_ABS:
674 		bitmap = evdev->ev_abs_flags;
675 		limit = ABS_CNT;
676 		break;
677 	case EV_MSC:
678 		bitmap = evdev->ev_msc_flags;
679 		limit = MSC_CNT;
680 		break;
681 	case EV_LED:
682 		bitmap = evdev->ev_led_flags;
683 		limit = LED_CNT;
684 		break;
685 	case EV_SND:
686 		bitmap = evdev->ev_snd_flags;
687 		limit = SND_CNT;
688 		break;
689 	case EV_SW:
690 		bitmap = evdev->ev_sw_flags;
691 		limit = SW_CNT;
692 		break;
693 	case EV_FF:
694 		/*
695 		 * We don't support EV_FF now, so let's
696 		 * just fake it returning only zeros.
697 		 */
698 		bzero(data, len);
699 		return (0);
700 	default:
701 		return (ENOTTY);
702 	}
703 
704 	/*
705 	 * Clear ioctl data buffer in case it's bigger than
706 	 * bitmap size
707 	 */
708 	bzero(data, len);
709 
710 	limit = bitstr_size(limit);
711 	len = MIN(limit, len);
712 	memcpy(data, bitmap, len);
713 	return (0);
714 }
715 
716 void
717 evdev_revoke_client(struct evdev_client *client)
718 {
719 
720 	EVDEV_LOCK_ASSERT(client->ec_evdev);
721 
722 	client->ec_revoked = true;
723 }
724 
725 void
726 evdev_notify_event(struct evdev_client *client)
727 {
728 
729 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
730 
731 	if (client->ec_blocked) {
732 		client->ec_blocked = false;
733 		wakeup(client);
734 	}
735 	if (client->ec_selected) {
736 		client->ec_selected = false;
737 		selwakeup(&client->ec_selp);
738 	}
739 	KNOTE_LOCKED(&client->ec_selp.si_note, 0);
740 
741 	if (client->ec_async && client->ec_sigio != NULL)
742 		pgsigio(&client->ec_sigio, SIGIO, 0);
743 }
744 
745 int
746 evdev_cdev_create(struct evdev_dev *evdev)
747 {
748 	struct make_dev_args mda;
749 	int ret, unit = 0;
750 
751 	make_dev_args_init(&mda);
752 	mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
753 	mda.mda_devsw = &evdev_cdevsw;
754 	mda.mda_uid = UID_ROOT;
755 	mda.mda_gid = GID_WHEEL;
756 	mda.mda_mode = 0600;
757 	mda.mda_si_drv1 = evdev;
758 
759 	/* Try to coexist with cuse-backed input/event devices */
760 	while ((ret = make_dev_s(&mda, &evdev->ev_cdev, "input/event%d", unit))
761 	    == EEXIST)
762 		unit++;
763 
764 	if (ret == 0)
765 		evdev->ev_unit = unit;
766 
767 	return (ret);
768 }
769 
770 int
771 evdev_cdev_destroy(struct evdev_dev *evdev)
772 {
773 
774 	destroy_dev(evdev->ev_cdev);
775 	return (0);
776 }
777 
778 static void
779 evdev_client_gettime(struct evdev_client *client, struct timeval *tv)
780 {
781 
782 	switch (client->ec_clock_id) {
783 	case EV_CLOCK_BOOTTIME:
784 		/*
785 		 * XXX: FreeBSD does not support true POSIX monotonic clock.
786 		 *      So aliase EV_CLOCK_BOOTTIME to EV_CLOCK_MONOTONIC.
787 		 */
788 	case EV_CLOCK_MONOTONIC:
789 		microuptime(tv);
790 		break;
791 
792 	case EV_CLOCK_REALTIME:
793 	default:
794 		microtime(tv);
795 		break;
796 	}
797 }
798 
799 void
800 evdev_client_push(struct evdev_client *client, uint16_t type, uint16_t code,
801     int32_t value)
802 {
803 	struct timeval time;
804 	size_t count, head, tail, ready;
805 
806 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
807 	head = client->ec_buffer_head;
808 	tail = client->ec_buffer_tail;
809 	ready = client->ec_buffer_ready;
810 	count = client->ec_buffer_size;
811 
812 	/* If queue is full drop its content and place SYN_DROPPED event */
813 	if ((tail + 1) % count == head) {
814 		debugf(client, "client %p: buffer overflow", client);
815 
816 		head = (tail + count - 1) % count;
817 		client->ec_buffer[head] = (struct input_event) {
818 			.type = EV_SYN,
819 			.code = SYN_DROPPED,
820 			.value = 0
821 		};
822 		/*
823 		 * XXX: Here is a small race window from now till the end of
824 		 *      report. The queue is empty but client has been already
825 		 *      notified of data readyness. Can be fixed in two ways:
826 		 * 1. Implement bulk insert so queue lock would not be dropped
827 		 *    till the SYN_REPORT event.
828 		 * 2. Insert SYN_REPORT just now and skip remaining events
829 		 */
830 		client->ec_buffer_head = head;
831 		client->ec_buffer_ready = head;
832 	}
833 
834 	client->ec_buffer[tail].type = type;
835 	client->ec_buffer[tail].code = code;
836 	client->ec_buffer[tail].value = value;
837 	client->ec_buffer_tail = (tail + 1) % count;
838 
839 	/* Allow users to read events only after report has been completed */
840 	if (type == EV_SYN && code == SYN_REPORT) {
841 		evdev_client_gettime(client, &time);
842 		for (; ready != client->ec_buffer_tail;
843 		    ready = (ready + 1) % count)
844 			client->ec_buffer[ready].time = time;
845 		client->ec_buffer_ready = client->ec_buffer_tail;
846 	}
847 }
848 
849 void
850 evdev_client_dumpqueue(struct evdev_client *client)
851 {
852 	struct input_event *event;
853 	size_t i, head, tail, ready, size;
854 
855 	head = client->ec_buffer_head;
856 	tail = client->ec_buffer_tail;
857 	ready = client->ec_buffer_ready;
858 	size = client->ec_buffer_size;
859 
860 	printf("evdev client: %p\n", client);
861 	printf("event queue: head=%zu ready=%zu tail=%zu size=%zu\n",
862 	    head, ready, tail, size);
863 
864 	printf("queue contents:\n");
865 
866 	for (i = 0; i < size; i++) {
867 		event = &client->ec_buffer[i];
868 		printf("%zu: ", i);
869 
870 		if (i < head || i > tail)
871 			printf("unused\n");
872 		else
873 			printf("type=%d code=%d value=%d ", event->type,
874 			    event->code, event->value);
875 
876 		if (i == head)
877 			printf("<- head\n");
878 		else if (i == tail)
879 			printf("<- tail\n");
880 		else if (i == ready)
881 			printf("<- ready\n");
882 		else
883 			printf("\n");
884 	}
885 }
886 
887 static void
888 evdev_client_filter_queue(struct evdev_client *client, uint16_t type)
889 {
890 	struct input_event *event;
891 	size_t head, tail, count, i;
892 	bool last_was_syn = false;
893 
894 	EVDEV_CLIENT_LOCKQ(client);
895 
896 	i = head = client->ec_buffer_head;
897 	tail = client->ec_buffer_tail;
898 	count = client->ec_buffer_size;
899 	client->ec_buffer_ready = client->ec_buffer_tail;
900 
901 	while (i != client->ec_buffer_tail) {
902 		event = &client->ec_buffer[i];
903 		i = (i + 1) % count;
904 
905 		/* Skip event of given type */
906 		if (event->type == type)
907 			continue;
908 
909 		/* Remove empty SYN_REPORT events */
910 		if (event->type == EV_SYN && event->code == SYN_REPORT) {
911 			if (last_was_syn)
912 				continue;
913 			else
914 				client->ec_buffer_ready = (tail + 1) % count;
915 		}
916 
917 		/* Rewrite entry */
918 		memcpy(&client->ec_buffer[tail], event,
919 		    sizeof(struct input_event));
920 
921 		last_was_syn = (event->type == EV_SYN &&
922 		    event->code == SYN_REPORT);
923 
924 		tail = (tail + 1) % count;
925 	}
926 
927 	client->ec_buffer_head = i;
928 	client->ec_buffer_tail = tail;
929 
930 	EVDEV_CLIENT_UNLOCKQ(client);
931 }
932