xref: /freebsd/sys/dev/evdev/cdev.c (revision 9768746ba83efa02837c5b9c66348db6e900208f)
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/epoch.h>
36 #include <sys/filio.h>
37 #include <sys/fcntl.h>
38 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/poll.h>
41 #include <sys/proc.h>
42 #include <sys/selinfo.h>
43 #include <sys/systm.h>
44 #include <sys/time.h>
45 #include <sys/uio.h>
46 
47 #include <dev/evdev/evdev.h>
48 #include <dev/evdev/evdev_private.h>
49 #include <dev/evdev/input.h>
50 
51 #ifdef COMPAT_FREEBSD32
52 #include <sys/mount.h>
53 #include <sys/sysent.h>
54 #include <compat/freebsd32/freebsd32.h>
55 struct input_event32 {
56 	struct timeval32	time;
57 	uint16_t		type;
58 	uint16_t		code;
59 	int32_t			value;
60 };
61 #endif
62 
63 #ifdef EVDEV_DEBUG
64 #define	debugf(client, fmt, args...)	printf("evdev cdev: "fmt"\n", ##args)
65 #else
66 #define	debugf(client, fmt, args...)
67 #endif
68 
69 #define	DEF_RING_REPORTS	8
70 
71 static d_open_t		evdev_open;
72 static d_read_t		evdev_read;
73 static d_write_t	evdev_write;
74 static d_ioctl_t	evdev_ioctl;
75 static d_poll_t		evdev_poll;
76 static d_kqfilter_t	evdev_kqfilter;
77 
78 static int evdev_kqread(struct knote *kn, long hint);
79 static void evdev_kqdetach(struct knote *kn);
80 static void evdev_dtor(void *);
81 static int evdev_ioctl_eviocgbit(struct evdev_dev *, int, int, caddr_t,
82     struct thread *);
83 static void evdev_client_filter_queue(struct evdev_client *, uint16_t);
84 
85 static struct cdevsw evdev_cdevsw = {
86 	.d_version = D_VERSION,
87 	.d_open = evdev_open,
88 	.d_read = evdev_read,
89 	.d_write = evdev_write,
90 	.d_ioctl = evdev_ioctl,
91 	.d_poll = evdev_poll,
92 	.d_kqfilter = evdev_kqfilter,
93 	.d_name = "evdev",
94 };
95 
96 static struct filterops evdev_cdev_filterops = {
97 	.f_isfd = 1,
98 	.f_attach = NULL,
99 	.f_detach = evdev_kqdetach,
100 	.f_event = evdev_kqread,
101 };
102 
103 static int
104 evdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
105 {
106 	struct evdev_dev *evdev = dev->si_drv1;
107 	struct evdev_client *client;
108 	size_t buffer_size;
109 	int ret;
110 
111 	if (evdev == NULL)
112 		return (ENODEV);
113 
114 	/* Initialize client structure */
115 	buffer_size = evdev->ev_report_size * DEF_RING_REPORTS;
116 	client = malloc(offsetof(struct evdev_client, ec_buffer) +
117 	    sizeof(struct input_event) * buffer_size,
118 	    M_EVDEV, M_WAITOK | M_ZERO);
119 
120 	/* Initialize ring buffer */
121 	client->ec_buffer_size = buffer_size;
122 	client->ec_buffer_head = 0;
123 	client->ec_buffer_tail = 0;
124 	client->ec_buffer_ready = 0;
125 
126 	client->ec_evdev = evdev;
127 	mtx_init(&client->ec_buffer_mtx, "evclient", "evdev", MTX_DEF);
128 	knlist_init_mtx(&client->ec_selp.si_note, &client->ec_buffer_mtx);
129 
130 	ret = EVDEV_LIST_LOCK_SIG(evdev);
131 	if (ret != 0)
132 		goto out;
133 	/* Avoid race with evdev_unregister */
134 	if (dev->si_drv1 == NULL)
135 		ret = ENODEV;
136 	else
137 		ret = evdev_register_client(evdev, client);
138 	EVDEV_LIST_UNLOCK(evdev);
139 out:
140 	if (ret == 0)
141 		ret = devfs_set_cdevpriv(client, evdev_dtor);
142 	else
143 		client->ec_revoked = true;
144 
145 	if (ret != 0) {
146 		debugf(client, "cannot register evdev client");
147 		evdev_dtor(client);
148 	}
149 
150 	return (ret);
151 }
152 
153 static void
154 evdev_dtor(void *data)
155 {
156 	struct evdev_client *client = (struct evdev_client *)data;
157 
158 	EVDEV_LIST_LOCK(client->ec_evdev);
159 	if (!client->ec_revoked)
160 		evdev_dispose_client(client->ec_evdev, client);
161 	EVDEV_LIST_UNLOCK(client->ec_evdev);
162 
163 	if (client->ec_evdev->ev_lock_type != EV_LOCK_MTX)
164 		epoch_wait_preempt(INPUT_EPOCH);
165 	knlist_clear(&client->ec_selp.si_note, 0);
166 	seldrain(&client->ec_selp);
167 	knlist_destroy(&client->ec_selp.si_note);
168 	funsetown(&client->ec_sigio);
169 	mtx_destroy(&client->ec_buffer_mtx);
170 	free(client, M_EVDEV);
171 }
172 
173 static int
174 evdev_read(struct cdev *dev, struct uio *uio, int ioflag)
175 {
176 	struct evdev_client *client;
177 	union {
178 		struct input_event t;
179 #ifdef COMPAT_FREEBSD32
180 		struct input_event32 t32;
181 #endif
182 	} event;
183 	struct input_event *head;
184 	size_t evsize;
185 	int ret = 0;
186 	int remaining;
187 
188 	ret = devfs_get_cdevpriv((void **)&client);
189 	if (ret != 0)
190 		return (ret);
191 
192 	debugf(client, "read %zd bytes by thread %d", uio->uio_resid,
193 	    uio->uio_td->td_tid);
194 
195 	if (client->ec_revoked)
196 		return (ENODEV);
197 
198 #ifdef COMPAT_FREEBSD32
199 	if (SV_CURPROC_FLAG(SV_ILP32))
200 		evsize = sizeof(struct input_event32);
201 	else
202 #endif
203 		evsize = sizeof(struct input_event);
204 
205 	/* Zero-sized reads are allowed for error checking */
206 	if (uio->uio_resid != 0 && uio->uio_resid < evsize)
207 		return (EINVAL);
208 
209 	remaining = uio->uio_resid / evsize;
210 
211 	EVDEV_CLIENT_LOCKQ(client);
212 
213 	if (EVDEV_CLIENT_EMPTYQ(client)) {
214 		if (ioflag & O_NONBLOCK)
215 			ret = EWOULDBLOCK;
216 		else {
217 			if (remaining != 0) {
218 				client->ec_blocked = true;
219 				ret = mtx_sleep(client, &client->ec_buffer_mtx,
220 				    PCATCH, "evread", 0);
221 				if (ret == 0 && client->ec_revoked)
222 					ret = ENODEV;
223 			}
224 		}
225 	}
226 
227 	while (ret == 0 && !EVDEV_CLIENT_EMPTYQ(client) && remaining > 0) {
228 		head = client->ec_buffer + client->ec_buffer_head;
229 #ifdef COMPAT_FREEBSD32
230 		if (SV_CURPROC_FLAG(SV_ILP32)) {
231 			bzero(&event.t32, sizeof(struct input_event32));
232 			TV_CP(*head, event.t32, time);
233 			CP(*head, event.t32, type);
234 			CP(*head, event.t32, code);
235 			CP(*head, event.t32, value);
236 		} else
237 #endif
238 			bcopy(head, &event.t, evsize);
239 
240 		client->ec_buffer_head =
241 		    (client->ec_buffer_head + 1) % client->ec_buffer_size;
242 		remaining--;
243 
244 		EVDEV_CLIENT_UNLOCKQ(client);
245 		ret = uiomove(&event, evsize, uio);
246 		EVDEV_CLIENT_LOCKQ(client);
247 	}
248 
249 	EVDEV_CLIENT_UNLOCKQ(client);
250 
251 	return (ret);
252 }
253 
254 static int
255 evdev_write(struct cdev *dev, struct uio *uio, int ioflag)
256 {
257 	struct evdev_dev *evdev = dev->si_drv1;
258 	struct evdev_client *client;
259 	union {
260 		struct input_event t;
261 #ifdef COMPAT_FREEBSD32
262 		struct input_event32 t32;
263 #endif
264 	} event;
265 	size_t evsize;
266 	int ret = 0;
267 
268 	ret = devfs_get_cdevpriv((void **)&client);
269 	if (ret != 0)
270 		return (ret);
271 
272 	debugf(client, "write %zd bytes by thread %d", uio->uio_resid,
273 	    uio->uio_td->td_tid);
274 
275 	if (client->ec_revoked || evdev == NULL)
276 		return (ENODEV);
277 
278 #ifdef COMPAT_FREEBSD32
279 	if (SV_CURPROC_FLAG(SV_ILP32))
280 		evsize = sizeof(struct input_event32);
281 	else
282 #endif
283 		evsize = sizeof(struct input_event);
284 
285 	if (uio->uio_resid % evsize != 0) {
286 		debugf(client, "write size not multiple of input_event size");
287 		return (EINVAL);
288 	}
289 
290 	while (uio->uio_resid > 0 && ret == 0) {
291 		ret = uiomove(&event, evsize, uio);
292 		if (ret == 0) {
293 #ifdef COMPAT_FREEBSD32
294 			if (SV_CURPROC_FLAG(SV_ILP32))
295 				ret = evdev_inject_event(evdev, event.t32.type,
296 				    event.t32.code, event.t32.value);
297 			else
298 #endif
299 				ret = evdev_inject_event(evdev, event.t.type,
300 				    event.t.code, event.t.value);
301 		}
302 	}
303 
304 	return (ret);
305 }
306 
307 static int
308 evdev_poll(struct cdev *dev, int events, struct thread *td)
309 {
310 	struct evdev_client *client;
311 	int ret;
312 	int revents = 0;
313 
314 	ret = devfs_get_cdevpriv((void **)&client);
315 	if (ret != 0)
316 		return (POLLNVAL);
317 
318 	debugf(client, "poll by thread %d", td->td_tid);
319 
320 	if (client->ec_revoked)
321 		return (POLLHUP);
322 
323 	if (events & (POLLIN | POLLRDNORM)) {
324 		EVDEV_CLIENT_LOCKQ(client);
325 		if (!EVDEV_CLIENT_EMPTYQ(client))
326 			revents = events & (POLLIN | POLLRDNORM);
327 		else {
328 			client->ec_selected = true;
329 			selrecord(td, &client->ec_selp);
330 		}
331 		EVDEV_CLIENT_UNLOCKQ(client);
332 	}
333 
334 	return (revents);
335 }
336 
337 static int
338 evdev_kqfilter(struct cdev *dev, struct knote *kn)
339 {
340 	struct evdev_client *client;
341 	int ret;
342 
343 	ret = devfs_get_cdevpriv((void **)&client);
344 	if (ret != 0)
345 		return (ret);
346 
347 	if (client->ec_revoked)
348 		return (ENODEV);
349 
350 	switch(kn->kn_filter) {
351 	case EVFILT_READ:
352 		kn->kn_fop = &evdev_cdev_filterops;
353 		break;
354 	default:
355 		return(EINVAL);
356 	}
357 	kn->kn_hook = (caddr_t)client;
358 
359 	knlist_add(&client->ec_selp.si_note, kn, 0);
360 	return (0);
361 }
362 
363 static int
364 evdev_kqread(struct knote *kn, long hint)
365 {
366 	struct evdev_client *client;
367 	int ret;
368 
369 	client = (struct evdev_client *)kn->kn_hook;
370 
371 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
372 
373 	if (client->ec_revoked) {
374 		kn->kn_flags |= EV_EOF;
375 		ret = 1;
376 	} else {
377 		kn->kn_data = EVDEV_CLIENT_SIZEQ(client) *
378 		    sizeof(struct input_event);
379 		ret = !EVDEV_CLIENT_EMPTYQ(client);
380 	}
381 	return (ret);
382 }
383 
384 static void
385 evdev_kqdetach(struct knote *kn)
386 {
387 	struct evdev_client *client;
388 
389 	client = (struct evdev_client *)kn->kn_hook;
390 	knlist_remove(&client->ec_selp.si_note, kn, 0);
391 }
392 
393 static int
394 evdev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
395     struct thread *td)
396 {
397 	struct evdev_dev *evdev = dev->si_drv1;
398 	struct evdev_client *client;
399 	struct input_keymap_entry *ke;
400 	struct epoch_tracker et;
401 	int ret, len, limit, type_num;
402 	uint32_t code;
403 	size_t nvalues;
404 
405 	ret = devfs_get_cdevpriv((void **)&client);
406 	if (ret != 0)
407 		return (ret);
408 
409 	if (client->ec_revoked || evdev == NULL)
410 		return (ENODEV);
411 
412 	/*
413 	 * Fix evdev state corrupted with discarding of kdb events.
414 	 * EVIOCGKEY and EVIOCGLED ioctls can suffer from this.
415 	 */
416 	if (evdev->ev_kdb_active) {
417 		EVDEV_LOCK(evdev);
418 		if (evdev->ev_kdb_active) {
419 			evdev->ev_kdb_active = false;
420 			if (evdev->ev_lock_type == EV_LOCK_EXT_EPOCH)
421 				epoch_enter_preempt(INPUT_EPOCH, &et);
422 			evdev_restore_after_kdb(evdev);
423 			if (evdev->ev_lock_type == EV_LOCK_EXT_EPOCH)
424 				epoch_exit_preempt(INPUT_EPOCH, &et);
425 		}
426 		EVDEV_UNLOCK(evdev);
427 	}
428 
429 	/* file I/O ioctl handling */
430 	switch (cmd) {
431 	case FIOSETOWN:
432 		return (fsetown(*(int *)data, &client->ec_sigio));
433 
434 	case FIOGETOWN:
435 		*(int *)data = fgetown(&client->ec_sigio);
436 		return (0);
437 
438 	case FIONBIO:
439 		return (0);
440 
441 	case FIOASYNC:
442 		if (*(int *)data)
443 			client->ec_async = true;
444 		else
445 			client->ec_async = false;
446 
447 		return (0);
448 
449 	case FIONREAD:
450 		EVDEV_CLIENT_LOCKQ(client);
451 		*(int *)data =
452 		    EVDEV_CLIENT_SIZEQ(client) * sizeof(struct input_event);
453 		EVDEV_CLIENT_UNLOCKQ(client);
454 		return (0);
455 	}
456 
457 	len = IOCPARM_LEN(cmd);
458 	debugf(client, "ioctl called: cmd=0x%08lx, data=%p", cmd, data);
459 
460 	/* evdev fixed-length ioctls handling */
461 	switch (cmd) {
462 	case EVIOCGVERSION:
463 		*(int *)data = EV_VERSION;
464 		return (0);
465 
466 	case EVIOCGID:
467 		debugf(client, "EVIOCGID: bus=%d vendor=0x%04x product=0x%04x",
468 		    evdev->ev_id.bustype, evdev->ev_id.vendor,
469 		    evdev->ev_id.product);
470 		memcpy(data, &evdev->ev_id, sizeof(struct input_id));
471 		return (0);
472 
473 	case EVIOCGREP:
474 		if (!evdev_event_supported(evdev, EV_REP))
475 			return (ENOTSUP);
476 
477 		memcpy(data, evdev->ev_rep, sizeof(evdev->ev_rep));
478 		return (0);
479 
480 	case EVIOCSREP:
481 		if (!evdev_event_supported(evdev, EV_REP))
482 			return (ENOTSUP);
483 
484 		evdev_inject_event(evdev, EV_REP, REP_DELAY, ((int *)data)[0]);
485 		evdev_inject_event(evdev, EV_REP, REP_PERIOD,
486 		    ((int *)data)[1]);
487 		return (0);
488 
489 	case EVIOCGKEYCODE:
490 		/* Fake unsupported ioctl */
491 		return (0);
492 
493 	case EVIOCGKEYCODE_V2:
494 		if (evdev->ev_methods == NULL ||
495 		    evdev->ev_methods->ev_get_keycode == NULL)
496 			return (ENOTSUP);
497 
498 		ke = (struct input_keymap_entry *)data;
499 		evdev->ev_methods->ev_get_keycode(evdev, ke);
500 		return (0);
501 
502 	case EVIOCSKEYCODE:
503 		/* Fake unsupported ioctl */
504 		return (0);
505 
506 	case EVIOCSKEYCODE_V2:
507 		if (evdev->ev_methods == NULL ||
508 		    evdev->ev_methods->ev_set_keycode == NULL)
509 			return (ENOTSUP);
510 
511 		ke = (struct input_keymap_entry *)data;
512 		evdev->ev_methods->ev_set_keycode(evdev, ke);
513 		return (0);
514 
515 	case EVIOCGABS(0) ... EVIOCGABS(ABS_MAX):
516 		if (evdev->ev_absinfo == NULL)
517 			return (EINVAL);
518 
519 		memcpy(data, &evdev->ev_absinfo[cmd - EVIOCGABS(0)],
520 		    sizeof(struct input_absinfo));
521 		return (0);
522 
523 	case EVIOCSABS(0) ... EVIOCSABS(ABS_MAX):
524 		if (evdev->ev_absinfo == NULL)
525 			return (EINVAL);
526 
527 		code = cmd - EVIOCSABS(0);
528 		/* mt-slot number can not be changed */
529 		if (code == ABS_MT_SLOT)
530 			return (EINVAL);
531 
532 		EVDEV_LOCK(evdev);
533 		evdev_set_absinfo(evdev, code, (struct input_absinfo *)data);
534 		EVDEV_UNLOCK(evdev);
535 		return (0);
536 
537 	case EVIOCSFF:
538 	case EVIOCRMFF:
539 	case EVIOCGEFFECTS:
540 		/* Fake unsupported ioctls */
541 		return (0);
542 
543 	case EVIOCGRAB:
544 		EVDEV_LOCK(evdev);
545 		if (*(int *)data)
546 			ret = evdev_grab_client(evdev, client);
547 		else
548 			ret = evdev_release_client(evdev, client);
549 		EVDEV_UNLOCK(evdev);
550 		return (ret);
551 
552 	case EVIOCREVOKE:
553 		if (*(int *)data != 0)
554 			return (EINVAL);
555 
556 		EVDEV_LIST_LOCK(evdev);
557 		if (dev->si_drv1 != NULL && !client->ec_revoked) {
558 			evdev_dispose_client(evdev, client);
559 			evdev_revoke_client(client);
560 		}
561 		EVDEV_LIST_UNLOCK(evdev);
562 		return (0);
563 
564 	case EVIOCSCLOCKID:
565 		switch (*(int *)data) {
566 		case CLOCK_REALTIME:
567 			client->ec_clock_id = EV_CLOCK_REALTIME;
568 			return (0);
569 		case CLOCK_MONOTONIC:
570 			client->ec_clock_id = EV_CLOCK_MONOTONIC;
571 			return (0);
572 		default:
573 			return (EINVAL);
574 		}
575 	}
576 
577 	/* evdev variable-length ioctls handling */
578 	switch (IOCBASECMD(cmd)) {
579 	case EVIOCGNAME(0):
580 		/* Linux evdev does not terminate truncated strings with 0 */
581 		limit = MIN(strlen(evdev->ev_name) + 1, len);
582 		memcpy(data, evdev->ev_name, limit);
583 		td->td_retval[0] = limit;
584 		return (0);
585 
586 	case EVIOCGPHYS(0):
587 		if (evdev->ev_shortname[0] == 0)
588 			return (ENOENT);
589 
590 		limit = MIN(strlen(evdev->ev_shortname) + 1, len);
591 		memcpy(data, evdev->ev_shortname, limit);
592 		td->td_retval[0] = limit;
593 		return (0);
594 
595 	case EVIOCGUNIQ(0):
596 		if (evdev->ev_serial[0] == 0)
597 			return (ENOENT);
598 
599 		limit = MIN(strlen(evdev->ev_serial) + 1, len);
600 		memcpy(data, evdev->ev_serial, limit);
601 		td->td_retval[0] = limit;
602 		return (0);
603 
604 	case EVIOCGPROP(0):
605 		limit = MIN(len, bitstr_size(INPUT_PROP_CNT));
606 		memcpy(data, evdev->ev_prop_flags, limit);
607 		td->td_retval[0] = limit;
608 		return (0);
609 
610 	case EVIOCGMTSLOTS(0):
611 		/* EVIOCGMTSLOTS always returns 0 on success */
612 		if (evdev->ev_mt == NULL)
613 			return (EINVAL);
614 		if (len < sizeof(uint32_t))
615 			return (EINVAL);
616 		code = *(uint32_t *)data;
617 		if (!ABS_IS_MT(code))
618 			return (EINVAL);
619 
620 		nvalues =
621 		    MIN(len / sizeof(int32_t) - 1, MAXIMAL_MT_SLOT(evdev) + 1);
622 		for (int i = 0; i < nvalues; i++)
623 			((int32_t *)data)[i + 1] =
624 			    evdev_mt_get_value(evdev, i, code);
625 		return (0);
626 
627 	case EVIOCGKEY(0):
628 		limit = MIN(len, bitstr_size(KEY_CNT));
629 		EVDEV_LOCK(evdev);
630 		evdev_client_filter_queue(client, EV_KEY);
631 		memcpy(data, evdev->ev_key_states, limit);
632 		EVDEV_UNLOCK(evdev);
633 		td->td_retval[0] = limit;
634 		return (0);
635 
636 	case EVIOCGLED(0):
637 		limit = MIN(len, bitstr_size(LED_CNT));
638 		EVDEV_LOCK(evdev);
639 		evdev_client_filter_queue(client, EV_LED);
640 		memcpy(data, evdev->ev_led_states, limit);
641 		EVDEV_UNLOCK(evdev);
642 		td->td_retval[0] = limit;
643 		return (0);
644 
645 	case EVIOCGSND(0):
646 		limit = MIN(len, bitstr_size(SND_CNT));
647 		EVDEV_LOCK(evdev);
648 		evdev_client_filter_queue(client, EV_SND);
649 		memcpy(data, evdev->ev_snd_states, limit);
650 		EVDEV_UNLOCK(evdev);
651 		td->td_retval[0] = limit;
652 		return (0);
653 
654 	case EVIOCGSW(0):
655 		limit = MIN(len, bitstr_size(SW_CNT));
656 		EVDEV_LOCK(evdev);
657 		evdev_client_filter_queue(client, EV_SW);
658 		memcpy(data, evdev->ev_sw_states, limit);
659 		EVDEV_UNLOCK(evdev);
660 		td->td_retval[0] = limit;
661 		return (0);
662 
663 	case EVIOCGBIT(0, 0) ... EVIOCGBIT(EV_MAX, 0):
664 		type_num = IOCBASECMD(cmd) - EVIOCGBIT(0, 0);
665 		debugf(client, "EVIOCGBIT(%d): data=%p, len=%d", type_num,
666 		    data, len);
667 		return (evdev_ioctl_eviocgbit(evdev, type_num, len, data, td));
668 	}
669 
670 	return (EINVAL);
671 }
672 
673 static int
674 evdev_ioctl_eviocgbit(struct evdev_dev *evdev, int type, int len, caddr_t data,
675     struct thread *td)
676 {
677 	unsigned long *bitmap;
678 	int limit;
679 
680 	switch (type) {
681 	case 0:
682 		bitmap = evdev->ev_type_flags;
683 		limit = EV_CNT;
684 		break;
685 	case EV_KEY:
686 		bitmap = evdev->ev_key_flags;
687 		limit = KEY_CNT;
688 		break;
689 	case EV_REL:
690 		bitmap = evdev->ev_rel_flags;
691 		limit = REL_CNT;
692 		break;
693 	case EV_ABS:
694 		bitmap = evdev->ev_abs_flags;
695 		limit = ABS_CNT;
696 		break;
697 	case EV_MSC:
698 		bitmap = evdev->ev_msc_flags;
699 		limit = MSC_CNT;
700 		break;
701 	case EV_LED:
702 		bitmap = evdev->ev_led_flags;
703 		limit = LED_CNT;
704 		break;
705 	case EV_SND:
706 		bitmap = evdev->ev_snd_flags;
707 		limit = SND_CNT;
708 		break;
709 	case EV_SW:
710 		bitmap = evdev->ev_sw_flags;
711 		limit = SW_CNT;
712 		break;
713 	case EV_FF:
714 		/*
715 		 * We don't support EV_FF now, so let's
716 		 * just fake it returning only zeros.
717 		 */
718 		bzero(data, len);
719 		td->td_retval[0] = len;
720 		return (0);
721 	default:
722 		return (ENOTTY);
723 	}
724 
725 	/*
726 	 * Clear ioctl data buffer in case it's bigger than
727 	 * bitmap size
728 	 */
729 	bzero(data, len);
730 
731 	limit = bitstr_size(limit);
732 	len = MIN(limit, len);
733 	memcpy(data, bitmap, len);
734 	td->td_retval[0] = len;
735 	return (0);
736 }
737 
738 void
739 evdev_revoke_client(struct evdev_client *client)
740 {
741 
742 	EVDEV_LIST_LOCK_ASSERT(client->ec_evdev);
743 
744 	client->ec_revoked = true;
745 }
746 
747 void
748 evdev_notify_event(struct evdev_client *client)
749 {
750 
751 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
752 
753 	if (client->ec_blocked) {
754 		client->ec_blocked = false;
755 		wakeup(client);
756 	}
757 	if (client->ec_selected) {
758 		client->ec_selected = false;
759 		selwakeup(&client->ec_selp);
760 	}
761 	KNOTE_LOCKED(&client->ec_selp.si_note, 0);
762 
763 	if (client->ec_async && client->ec_sigio != NULL)
764 		pgsigio(&client->ec_sigio, SIGIO, 0);
765 }
766 
767 int
768 evdev_cdev_create(struct evdev_dev *evdev)
769 {
770 	struct make_dev_args mda;
771 	int ret, unit = 0;
772 
773 	make_dev_args_init(&mda);
774 	mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
775 	mda.mda_devsw = &evdev_cdevsw;
776 	mda.mda_uid = UID_ROOT;
777 	mda.mda_gid = GID_WHEEL;
778 	mda.mda_mode = 0600;
779 	mda.mda_si_drv1 = evdev;
780 
781 	/* Try to coexist with cuse-backed input/event devices */
782 	while ((ret = make_dev_s(&mda, &evdev->ev_cdev, "input/event%d", unit))
783 	    == EEXIST)
784 		unit++;
785 
786 	if (ret == 0)
787 		evdev->ev_unit = unit;
788 
789 	return (ret);
790 }
791 
792 int
793 evdev_cdev_destroy(struct evdev_dev *evdev)
794 {
795 
796 	destroy_dev(evdev->ev_cdev);
797 	return (0);
798 }
799 
800 static void
801 evdev_client_gettime(struct evdev_client *client, struct timeval *tv)
802 {
803 
804 	switch (client->ec_clock_id) {
805 	case EV_CLOCK_BOOTTIME:
806 		/*
807 		 * XXX: FreeBSD does not support true POSIX monotonic clock.
808 		 *      So aliase EV_CLOCK_BOOTTIME to EV_CLOCK_MONOTONIC.
809 		 */
810 	case EV_CLOCK_MONOTONIC:
811 		microuptime(tv);
812 		break;
813 
814 	case EV_CLOCK_REALTIME:
815 	default:
816 		microtime(tv);
817 		break;
818 	}
819 }
820 
821 void
822 evdev_client_push(struct evdev_client *client, uint16_t type, uint16_t code,
823     int32_t value)
824 {
825 	struct timeval time;
826 	size_t count, head, tail, ready;
827 
828 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
829 	head = client->ec_buffer_head;
830 	tail = client->ec_buffer_tail;
831 	ready = client->ec_buffer_ready;
832 	count = client->ec_buffer_size;
833 
834 	/* If queue is full drop its content and place SYN_DROPPED event */
835 	if ((tail + 1) % count == head) {
836 		debugf(client, "client %p: buffer overflow", client);
837 
838 		head = (tail + count - 1) % count;
839 		client->ec_buffer[head] = (struct input_event) {
840 			.type = EV_SYN,
841 			.code = SYN_DROPPED,
842 			.value = 0
843 		};
844 		/*
845 		 * XXX: Here is a small race window from now till the end of
846 		 *      report. The queue is empty but client has been already
847 		 *      notified of data readyness. Can be fixed in two ways:
848 		 * 1. Implement bulk insert so queue lock would not be dropped
849 		 *    till the SYN_REPORT event.
850 		 * 2. Insert SYN_REPORT just now and skip remaining events
851 		 */
852 		client->ec_buffer_head = head;
853 		client->ec_buffer_ready = head;
854 	}
855 
856 	client->ec_buffer[tail].type = type;
857 	client->ec_buffer[tail].code = code;
858 	client->ec_buffer[tail].value = value;
859 	client->ec_buffer_tail = (tail + 1) % count;
860 
861 	/* Allow users to read events only after report has been completed */
862 	if (type == EV_SYN && code == SYN_REPORT) {
863 		evdev_client_gettime(client, &time);
864 		for (; ready != client->ec_buffer_tail;
865 		    ready = (ready + 1) % count)
866 			client->ec_buffer[ready].time = time;
867 		client->ec_buffer_ready = client->ec_buffer_tail;
868 	}
869 }
870 
871 void
872 evdev_client_dumpqueue(struct evdev_client *client)
873 {
874 	struct input_event *event;
875 	size_t i, head, tail, ready, size;
876 
877 	head = client->ec_buffer_head;
878 	tail = client->ec_buffer_tail;
879 	ready = client->ec_buffer_ready;
880 	size = client->ec_buffer_size;
881 
882 	printf("evdev client: %p\n", client);
883 	printf("event queue: head=%zu ready=%zu tail=%zu size=%zu\n",
884 	    head, ready, tail, size);
885 
886 	printf("queue contents:\n");
887 
888 	for (i = 0; i < size; i++) {
889 		event = &client->ec_buffer[i];
890 		printf("%zu: ", i);
891 
892 		if (i < head || i > tail)
893 			printf("unused\n");
894 		else
895 			printf("type=%d code=%d value=%d ", event->type,
896 			    event->code, event->value);
897 
898 		if (i == head)
899 			printf("<- head\n");
900 		else if (i == tail)
901 			printf("<- tail\n");
902 		else if (i == ready)
903 			printf("<- ready\n");
904 		else
905 			printf("\n");
906 	}
907 }
908 
909 static void
910 evdev_client_filter_queue(struct evdev_client *client, uint16_t type)
911 {
912 	struct input_event *event;
913 	size_t head, tail, count, i;
914 	bool last_was_syn = false;
915 
916 	EVDEV_CLIENT_LOCKQ(client);
917 
918 	i = head = client->ec_buffer_head;
919 	tail = client->ec_buffer_tail;
920 	count = client->ec_buffer_size;
921 	client->ec_buffer_ready = client->ec_buffer_tail;
922 
923 	while (i != client->ec_buffer_tail) {
924 		event = &client->ec_buffer[i];
925 		i = (i + 1) % count;
926 
927 		/* Skip event of given type */
928 		if (event->type == type)
929 			continue;
930 
931 		/* Remove empty SYN_REPORT events */
932 		if (event->type == EV_SYN && event->code == SYN_REPORT) {
933 			if (last_was_syn)
934 				continue;
935 			else
936 				client->ec_buffer_ready = (tail + 1) % count;
937 		}
938 
939 		/* Rewrite entry */
940 		memcpy(&client->ec_buffer[tail], event,
941 		    sizeof(struct input_event));
942 
943 		last_was_syn = (event->type == EV_SYN &&
944 		    event->code == SYN_REPORT);
945 
946 		tail = (tail + 1) % count;
947 	}
948 
949 	client->ec_buffer_head = i;
950 	client->ec_buffer_tail = tail;
951 
952 	EVDEV_CLIENT_UNLOCKQ(client);
953 }
954