xref: /freebsd/sys/dev/evdev/cdev.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
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 
28 #include "opt_evdev.h"
29 
30 #include <sys/param.h>
31 #include <sys/bitstring.h>
32 #include <sys/conf.h>
33 #include <sys/epoch.h>
34 #include <sys/filio.h>
35 #include <sys/fcntl.h>
36 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/poll.h>
39 #include <sys/proc.h>
40 #include <sys/selinfo.h>
41 #include <sys/systm.h>
42 #include <sys/time.h>
43 #include <sys/uio.h>
44 
45 #include <dev/evdev/evdev.h>
46 #include <dev/evdev/evdev_private.h>
47 #include <dev/evdev/input.h>
48 
49 #ifdef COMPAT_FREEBSD32
50 #include <sys/mount.h>
51 #include <sys/sysent.h>
52 #include <compat/freebsd32/freebsd32.h>
53 struct input_event32 {
54 	struct timeval32	time;
55 	uint16_t		type;
56 	uint16_t		code;
57 	int32_t			value;
58 };
59 #endif
60 
61 #ifdef EVDEV_DEBUG
62 #define	debugf(client, fmt, args...)	printf("evdev cdev: "fmt"\n", ##args)
63 #else
64 #define	debugf(client, fmt, args...)
65 #endif
66 
67 #define	DEF_RING_REPORTS	8
68 
69 static d_open_t		evdev_open;
70 static d_read_t		evdev_read;
71 static d_write_t	evdev_write;
72 static d_ioctl_t	evdev_ioctl;
73 static d_poll_t		evdev_poll;
74 static d_kqfilter_t	evdev_kqfilter;
75 
76 static int evdev_kqread(struct knote *kn, long hint);
77 static void evdev_kqdetach(struct knote *kn);
78 static void evdev_dtor(void *);
79 static int evdev_ioctl_eviocgbit(struct evdev_dev *, int, int, caddr_t,
80     struct thread *);
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 	ret = EVDEV_LIST_LOCK_SIG(evdev);
129 	if (ret != 0)
130 		goto out;
131 	/* Avoid race with evdev_unregister */
132 	if (dev->si_drv1 == NULL)
133 		ret = ENODEV;
134 	else
135 		ret = evdev_register_client(evdev, client);
136 	EVDEV_LIST_UNLOCK(evdev);
137 out:
138 	if (ret == 0)
139 		ret = devfs_set_cdevpriv(client, evdev_dtor);
140 	else
141 		client->ec_revoked = true;
142 
143 	if (ret != 0) {
144 		debugf(client, "cannot register evdev client");
145 		evdev_dtor(client);
146 	}
147 
148 	return (ret);
149 }
150 
151 static void
152 evdev_dtor(void *data)
153 {
154 	struct evdev_client *client = (struct evdev_client *)data;
155 
156 	EVDEV_LIST_LOCK(client->ec_evdev);
157 	if (!client->ec_revoked)
158 		evdev_dispose_client(client->ec_evdev, client);
159 	EVDEV_LIST_UNLOCK(client->ec_evdev);
160 
161 	if (client->ec_evdev->ev_lock_type != EV_LOCK_MTX)
162 		epoch_wait_preempt(INPUT_EPOCH);
163 	knlist_clear(&client->ec_selp.si_note, 0);
164 	seldrain(&client->ec_selp);
165 	knlist_destroy(&client->ec_selp.si_note);
166 	funsetown(&client->ec_sigio);
167 	mtx_destroy(&client->ec_buffer_mtx);
168 	free(client, M_EVDEV);
169 }
170 
171 static int
172 evdev_read(struct cdev *dev, struct uio *uio, int ioflag)
173 {
174 	struct evdev_client *client;
175 	union {
176 		struct input_event t;
177 #ifdef COMPAT_FREEBSD32
178 		struct input_event32 t32;
179 #endif
180 	} event;
181 	struct input_event *head;
182 	size_t evsize;
183 	int ret = 0;
184 	int remaining;
185 
186 	ret = devfs_get_cdevpriv((void **)&client);
187 	if (ret != 0)
188 		return (ret);
189 
190 	debugf(client, "read %zd bytes by thread %d", uio->uio_resid,
191 	    uio->uio_td->td_tid);
192 
193 	if (client->ec_revoked)
194 		return (ENODEV);
195 
196 #ifdef COMPAT_FREEBSD32
197 	if (SV_CURPROC_FLAG(SV_ILP32))
198 		evsize = sizeof(struct input_event32);
199 	else
200 #endif
201 		evsize = sizeof(struct input_event);
202 
203 	/* Zero-sized reads are allowed for error checking */
204 	if (uio->uio_resid != 0 && uio->uio_resid < evsize)
205 		return (EINVAL);
206 
207 	remaining = uio->uio_resid / evsize;
208 
209 	EVDEV_CLIENT_LOCKQ(client);
210 
211 	if (EVDEV_CLIENT_EMPTYQ(client)) {
212 		if (ioflag & O_NONBLOCK)
213 			ret = EWOULDBLOCK;
214 		else {
215 			if (remaining != 0) {
216 				client->ec_blocked = true;
217 				ret = mtx_sleep(client, &client->ec_buffer_mtx,
218 				    PCATCH, "evread", 0);
219 				if (ret == 0 && client->ec_revoked)
220 					ret = ENODEV;
221 			}
222 		}
223 	}
224 
225 	while (ret == 0 && !EVDEV_CLIENT_EMPTYQ(client) && remaining > 0) {
226 		head = client->ec_buffer + client->ec_buffer_head;
227 #ifdef COMPAT_FREEBSD32
228 		if (SV_CURPROC_FLAG(SV_ILP32)) {
229 			bzero(&event.t32, sizeof(struct input_event32));
230 			TV_CP(*head, event.t32, time);
231 			CP(*head, event.t32, type);
232 			CP(*head, event.t32, code);
233 			CP(*head, event.t32, value);
234 		} else
235 #endif
236 			bcopy(head, &event.t, evsize);
237 
238 		client->ec_buffer_head =
239 		    (client->ec_buffer_head + 1) % client->ec_buffer_size;
240 		remaining--;
241 
242 		EVDEV_CLIENT_UNLOCKQ(client);
243 		ret = uiomove(&event, evsize, uio);
244 		EVDEV_CLIENT_LOCKQ(client);
245 	}
246 
247 	EVDEV_CLIENT_UNLOCKQ(client);
248 
249 	return (ret);
250 }
251 
252 static int
253 evdev_write(struct cdev *dev, struct uio *uio, int ioflag)
254 {
255 	struct evdev_dev *evdev = dev->si_drv1;
256 	struct evdev_client *client;
257 	union {
258 		struct input_event t;
259 #ifdef COMPAT_FREEBSD32
260 		struct input_event32 t32;
261 #endif
262 	} event;
263 	size_t evsize;
264 	int ret = 0;
265 
266 	ret = devfs_get_cdevpriv((void **)&client);
267 	if (ret != 0)
268 		return (ret);
269 
270 	debugf(client, "write %zd bytes by thread %d", uio->uio_resid,
271 	    uio->uio_td->td_tid);
272 
273 	if (client->ec_revoked || evdev == NULL)
274 		return (ENODEV);
275 
276 #ifdef COMPAT_FREEBSD32
277 	if (SV_CURPROC_FLAG(SV_ILP32))
278 		evsize = sizeof(struct input_event32);
279 	else
280 #endif
281 		evsize = sizeof(struct input_event);
282 
283 	if (uio->uio_resid % evsize != 0) {
284 		debugf(client, "write size not multiple of input_event size");
285 		return (EINVAL);
286 	}
287 
288 	while (uio->uio_resid > 0 && ret == 0) {
289 		ret = uiomove(&event, evsize, uio);
290 		if (ret == 0) {
291 #ifdef COMPAT_FREEBSD32
292 			if (SV_CURPROC_FLAG(SV_ILP32))
293 				ret = evdev_inject_event(evdev, event.t32.type,
294 				    event.t32.code, event.t32.value);
295 			else
296 #endif
297 				ret = evdev_inject_event(evdev, event.t.type,
298 				    event.t.code, event.t.value);
299 		}
300 	}
301 
302 	return (ret);
303 }
304 
305 static int
306 evdev_poll(struct cdev *dev, int events, struct thread *td)
307 {
308 	struct evdev_client *client;
309 	int ret;
310 	int revents = 0;
311 
312 	ret = devfs_get_cdevpriv((void **)&client);
313 	if (ret != 0)
314 		return (POLLNVAL);
315 
316 	debugf(client, "poll by thread %d", td->td_tid);
317 
318 	if (client->ec_revoked)
319 		return (POLLHUP);
320 
321 	if (events & (POLLIN | POLLRDNORM)) {
322 		EVDEV_CLIENT_LOCKQ(client);
323 		if (!EVDEV_CLIENT_EMPTYQ(client))
324 			revents = events & (POLLIN | POLLRDNORM);
325 		else {
326 			client->ec_selected = true;
327 			selrecord(td, &client->ec_selp);
328 		}
329 		EVDEV_CLIENT_UNLOCKQ(client);
330 	}
331 
332 	return (revents);
333 }
334 
335 static int
336 evdev_kqfilter(struct cdev *dev, struct knote *kn)
337 {
338 	struct evdev_client *client;
339 	int ret;
340 
341 	ret = devfs_get_cdevpriv((void **)&client);
342 	if (ret != 0)
343 		return (ret);
344 
345 	if (client->ec_revoked)
346 		return (ENODEV);
347 
348 	switch(kn->kn_filter) {
349 	case EVFILT_READ:
350 		kn->kn_fop = &evdev_cdev_filterops;
351 		break;
352 	default:
353 		return(EINVAL);
354 	}
355 	kn->kn_hook = (caddr_t)client;
356 
357 	knlist_add(&client->ec_selp.si_note, kn, 0);
358 	return (0);
359 }
360 
361 static int
362 evdev_kqread(struct knote *kn, long hint)
363 {
364 	struct evdev_client *client;
365 	int ret;
366 
367 	client = (struct evdev_client *)kn->kn_hook;
368 
369 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
370 
371 	if (client->ec_revoked) {
372 		kn->kn_flags |= EV_EOF;
373 		ret = 1;
374 	} else {
375 		kn->kn_data = EVDEV_CLIENT_SIZEQ(client) *
376 		    sizeof(struct input_event);
377 		ret = !EVDEV_CLIENT_EMPTYQ(client);
378 	}
379 	return (ret);
380 }
381 
382 static void
383 evdev_kqdetach(struct knote *kn)
384 {
385 	struct evdev_client *client;
386 
387 	client = (struct evdev_client *)kn->kn_hook;
388 	knlist_remove(&client->ec_selp.si_note, kn, 0);
389 }
390 
391 static int
392 evdev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
393     struct thread *td)
394 {
395 	struct evdev_dev *evdev = dev->si_drv1;
396 	struct evdev_client *client;
397 	struct input_keymap_entry *ke;
398 	struct epoch_tracker et;
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 			if (evdev->ev_lock_type == EV_LOCK_EXT_EPOCH)
419 				epoch_enter_preempt(INPUT_EPOCH, &et);
420 			evdev_restore_after_kdb(evdev);
421 			if (evdev->ev_lock_type == EV_LOCK_EXT_EPOCH)
422 				epoch_exit_preempt(INPUT_EPOCH, &et);
423 		}
424 		EVDEV_UNLOCK(evdev);
425 	}
426 
427 	/* file I/O ioctl handling */
428 	switch (cmd) {
429 	case FIOSETOWN:
430 		return (fsetown(*(int *)data, &client->ec_sigio));
431 
432 	case FIOGETOWN:
433 		*(int *)data = fgetown(&client->ec_sigio);
434 		return (0);
435 
436 	case FIONBIO:
437 		return (0);
438 
439 	case FIOASYNC:
440 		if (*(int *)data)
441 			client->ec_async = true;
442 		else
443 			client->ec_async = false;
444 
445 		return (0);
446 
447 	case FIONREAD:
448 		EVDEV_CLIENT_LOCKQ(client);
449 		*(int *)data =
450 		    EVDEV_CLIENT_SIZEQ(client) * sizeof(struct input_event);
451 		EVDEV_CLIENT_UNLOCKQ(client);
452 		return (0);
453 	}
454 
455 	len = IOCPARM_LEN(cmd);
456 	debugf(client, "ioctl called: cmd=0x%08lx, data=%p", cmd, data);
457 
458 	/* evdev fixed-length ioctls handling */
459 	switch (cmd) {
460 	case EVIOCGVERSION:
461 		*(int *)data = EV_VERSION;
462 		return (0);
463 
464 	case EVIOCGID:
465 		debugf(client, "EVIOCGID: bus=%d vendor=0x%04x product=0x%04x",
466 		    evdev->ev_id.bustype, evdev->ev_id.vendor,
467 		    evdev->ev_id.product);
468 		memcpy(data, &evdev->ev_id, sizeof(struct input_id));
469 		return (0);
470 
471 	case EVIOCGREP:
472 		if (!evdev_event_supported(evdev, EV_REP))
473 			return (ENOTSUP);
474 
475 		memcpy(data, evdev->ev_rep, sizeof(evdev->ev_rep));
476 		return (0);
477 
478 	case EVIOCSREP:
479 		if (!evdev_event_supported(evdev, EV_REP))
480 			return (ENOTSUP);
481 
482 		evdev_inject_event(evdev, EV_REP, REP_DELAY, ((int *)data)[0]);
483 		evdev_inject_event(evdev, EV_REP, REP_PERIOD,
484 		    ((int *)data)[1]);
485 		return (0);
486 
487 	case EVIOCGKEYCODE:
488 		/* Fake unsupported ioctl */
489 		return (0);
490 
491 	case EVIOCGKEYCODE_V2:
492 		if (evdev->ev_methods == NULL ||
493 		    evdev->ev_methods->ev_get_keycode == NULL)
494 			return (ENOTSUP);
495 
496 		ke = (struct input_keymap_entry *)data;
497 		evdev->ev_methods->ev_get_keycode(evdev, ke);
498 		return (0);
499 
500 	case EVIOCSKEYCODE:
501 		/* Fake unsupported ioctl */
502 		return (0);
503 
504 	case EVIOCSKEYCODE_V2:
505 		if (evdev->ev_methods == NULL ||
506 		    evdev->ev_methods->ev_set_keycode == NULL)
507 			return (ENOTSUP);
508 
509 		ke = (struct input_keymap_entry *)data;
510 		evdev->ev_methods->ev_set_keycode(evdev, ke);
511 		return (0);
512 
513 	case EVIOCGABS(0) ... EVIOCGABS(ABS_MAX):
514 		if (evdev->ev_absinfo == NULL)
515 			return (EINVAL);
516 
517 		memcpy(data, &evdev->ev_absinfo[cmd - EVIOCGABS(0)],
518 		    sizeof(struct input_absinfo));
519 		return (0);
520 
521 	case EVIOCSABS(0) ... EVIOCSABS(ABS_MAX):
522 		if (evdev->ev_absinfo == NULL)
523 			return (EINVAL);
524 
525 		code = cmd - EVIOCSABS(0);
526 		/* mt-slot number can not be changed */
527 		if (code == ABS_MT_SLOT)
528 			return (EINVAL);
529 
530 		EVDEV_LOCK(evdev);
531 		evdev_set_absinfo(evdev, code, (struct input_absinfo *)data);
532 		EVDEV_UNLOCK(evdev);
533 		return (0);
534 
535 	case EVIOCSFF:
536 	case EVIOCRMFF:
537 	case EVIOCGEFFECTS:
538 		/* Fake unsupported ioctls */
539 		return (0);
540 
541 	case EVIOCGRAB:
542 		EVDEV_LOCK(evdev);
543 		if (*(int *)data)
544 			ret = evdev_grab_client(evdev, client);
545 		else
546 			ret = evdev_release_client(evdev, client);
547 		EVDEV_UNLOCK(evdev);
548 		return (ret);
549 
550 	case EVIOCREVOKE:
551 		if (*(int *)data != 0)
552 			return (EINVAL);
553 
554 		EVDEV_LIST_LOCK(evdev);
555 		if (dev->si_drv1 != NULL && !client->ec_revoked) {
556 			evdev_dispose_client(evdev, client);
557 			evdev_revoke_client(client);
558 		}
559 		EVDEV_LIST_UNLOCK(evdev);
560 		return (0);
561 
562 	case EVIOCSCLOCKID:
563 		switch (*(int *)data) {
564 		case CLOCK_REALTIME:
565 			client->ec_clock_id = EV_CLOCK_REALTIME;
566 			return (0);
567 		case CLOCK_MONOTONIC:
568 			client->ec_clock_id = EV_CLOCK_MONOTONIC;
569 			return (0);
570 		default:
571 			return (EINVAL);
572 		}
573 	}
574 
575 	/* evdev variable-length ioctls handling */
576 	switch (IOCBASECMD(cmd)) {
577 	case EVIOCGNAME(0):
578 		/* Linux evdev does not terminate truncated strings with 0 */
579 		limit = MIN(strlen(evdev->ev_name) + 1, len);
580 		memcpy(data, evdev->ev_name, limit);
581 		td->td_retval[0] = limit;
582 		return (0);
583 
584 	case EVIOCGPHYS(0):
585 		if (evdev->ev_shortname[0] == 0)
586 			return (ENOENT);
587 
588 		limit = MIN(strlen(evdev->ev_shortname) + 1, len);
589 		memcpy(data, evdev->ev_shortname, limit);
590 		td->td_retval[0] = limit;
591 		return (0);
592 
593 	case EVIOCGUNIQ(0):
594 		if (evdev->ev_serial[0] == 0)
595 			return (ENOENT);
596 
597 		limit = MIN(strlen(evdev->ev_serial) + 1, len);
598 		memcpy(data, evdev->ev_serial, limit);
599 		td->td_retval[0] = limit;
600 		return (0);
601 
602 	case EVIOCGPROP(0):
603 		limit = MIN(len, bitstr_size(INPUT_PROP_CNT));
604 		memcpy(data, evdev->ev_prop_flags, limit);
605 		td->td_retval[0] = limit;
606 		return (0);
607 
608 	case EVIOCGMTSLOTS(0):
609 		/* EVIOCGMTSLOTS always returns 0 on success */
610 		if (evdev->ev_mt == NULL)
611 			return (EINVAL);
612 		if (len < sizeof(uint32_t))
613 			return (EINVAL);
614 		code = *(uint32_t *)data;
615 		if (!ABS_IS_MT(code))
616 			return (EINVAL);
617 
618 		nvalues =
619 		    MIN(len / sizeof(int32_t) - 1, MAXIMAL_MT_SLOT(evdev) + 1);
620 		for (int i = 0; i < nvalues; i++)
621 			((int32_t *)data)[i + 1] =
622 			    evdev_mt_get_value(evdev, i, code);
623 		return (0);
624 
625 	case EVIOCGKEY(0):
626 		limit = MIN(len, bitstr_size(KEY_CNT));
627 		EVDEV_LOCK(evdev);
628 		evdev_client_filter_queue(client, EV_KEY);
629 		memcpy(data, evdev->ev_key_states, limit);
630 		EVDEV_UNLOCK(evdev);
631 		td->td_retval[0] = limit;
632 		return (0);
633 
634 	case EVIOCGLED(0):
635 		limit = MIN(len, bitstr_size(LED_CNT));
636 		EVDEV_LOCK(evdev);
637 		evdev_client_filter_queue(client, EV_LED);
638 		memcpy(data, evdev->ev_led_states, limit);
639 		EVDEV_UNLOCK(evdev);
640 		td->td_retval[0] = limit;
641 		return (0);
642 
643 	case EVIOCGSND(0):
644 		limit = MIN(len, bitstr_size(SND_CNT));
645 		EVDEV_LOCK(evdev);
646 		evdev_client_filter_queue(client, EV_SND);
647 		memcpy(data, evdev->ev_snd_states, limit);
648 		EVDEV_UNLOCK(evdev);
649 		td->td_retval[0] = limit;
650 		return (0);
651 
652 	case EVIOCGSW(0):
653 		limit = MIN(len, bitstr_size(SW_CNT));
654 		EVDEV_LOCK(evdev);
655 		evdev_client_filter_queue(client, EV_SW);
656 		memcpy(data, evdev->ev_sw_states, limit);
657 		EVDEV_UNLOCK(evdev);
658 		td->td_retval[0] = limit;
659 		return (0);
660 
661 	case EVIOCGBIT(0, 0) ... EVIOCGBIT(EV_MAX, 0):
662 		type_num = IOCBASECMD(cmd) - EVIOCGBIT(0, 0);
663 		debugf(client, "EVIOCGBIT(%d): data=%p, len=%d", type_num,
664 		    data, len);
665 		return (evdev_ioctl_eviocgbit(evdev, type_num, len, data, td));
666 	}
667 
668 	return (EINVAL);
669 }
670 
671 static int
672 evdev_ioctl_eviocgbit(struct evdev_dev *evdev, int type, int len, caddr_t data,
673     struct thread *td)
674 {
675 	unsigned long *bitmap;
676 	int limit;
677 
678 	switch (type) {
679 	case 0:
680 		bitmap = evdev->ev_type_flags;
681 		limit = EV_CNT;
682 		break;
683 	case EV_KEY:
684 		bitmap = evdev->ev_key_flags;
685 		limit = KEY_CNT;
686 		break;
687 	case EV_REL:
688 		bitmap = evdev->ev_rel_flags;
689 		limit = REL_CNT;
690 		break;
691 	case EV_ABS:
692 		bitmap = evdev->ev_abs_flags;
693 		limit = ABS_CNT;
694 		break;
695 	case EV_MSC:
696 		bitmap = evdev->ev_msc_flags;
697 		limit = MSC_CNT;
698 		break;
699 	case EV_LED:
700 		bitmap = evdev->ev_led_flags;
701 		limit = LED_CNT;
702 		break;
703 	case EV_SND:
704 		bitmap = evdev->ev_snd_flags;
705 		limit = SND_CNT;
706 		break;
707 	case EV_SW:
708 		bitmap = evdev->ev_sw_flags;
709 		limit = SW_CNT;
710 		break;
711 	case EV_FF:
712 		/*
713 		 * We don't support EV_FF now, so let's
714 		 * just fake it returning only zeros.
715 		 */
716 		bzero(data, len);
717 		td->td_retval[0] = len;
718 		return (0);
719 	default:
720 		return (ENOTTY);
721 	}
722 
723 	/*
724 	 * Clear ioctl data buffer in case it's bigger than
725 	 * bitmap size
726 	 */
727 	bzero(data, len);
728 
729 	limit = bitstr_size(limit);
730 	len = MIN(limit, len);
731 	memcpy(data, bitmap, len);
732 	td->td_retval[0] = len;
733 	return (0);
734 }
735 
736 void
737 evdev_revoke_client(struct evdev_client *client)
738 {
739 
740 	EVDEV_LIST_LOCK_ASSERT(client->ec_evdev);
741 
742 	client->ec_revoked = true;
743 }
744 
745 void
746 evdev_notify_event(struct evdev_client *client)
747 {
748 
749 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
750 
751 	if (client->ec_blocked) {
752 		client->ec_blocked = false;
753 		wakeup(client);
754 	}
755 	if (client->ec_selected) {
756 		client->ec_selected = false;
757 		selwakeup(&client->ec_selp);
758 	}
759 	KNOTE_LOCKED(&client->ec_selp.si_note, 0);
760 
761 	if (client->ec_async && client->ec_sigio != NULL)
762 		pgsigio(&client->ec_sigio, SIGIO, 0);
763 }
764 
765 int
766 evdev_cdev_create(struct evdev_dev *evdev)
767 {
768 	struct make_dev_args mda;
769 	int ret, unit = 0;
770 
771 	make_dev_args_init(&mda);
772 	mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
773 	mda.mda_devsw = &evdev_cdevsw;
774 	mda.mda_uid = UID_ROOT;
775 	mda.mda_gid = GID_WHEEL;
776 	mda.mda_mode = 0600;
777 	mda.mda_si_drv1 = evdev;
778 
779 	/* Try to coexist with cuse-backed input/event devices */
780 	while ((ret = make_dev_s(&mda, &evdev->ev_cdev, "input/event%d", unit))
781 	    == EEXIST)
782 		unit++;
783 
784 	if (ret == 0)
785 		evdev->ev_unit = unit;
786 
787 	return (ret);
788 }
789 
790 int
791 evdev_cdev_destroy(struct evdev_dev *evdev)
792 {
793 
794 	destroy_dev(evdev->ev_cdev);
795 	return (0);
796 }
797 
798 static void
799 evdev_client_gettime(struct evdev_client *client, struct timeval *tv)
800 {
801 
802 	switch (client->ec_clock_id) {
803 	case EV_CLOCK_BOOTTIME:
804 		/*
805 		 * XXX: FreeBSD does not support true POSIX monotonic clock.
806 		 *      So aliase EV_CLOCK_BOOTTIME to EV_CLOCK_MONOTONIC.
807 		 */
808 	case EV_CLOCK_MONOTONIC:
809 		microuptime(tv);
810 		break;
811 
812 	case EV_CLOCK_REALTIME:
813 	default:
814 		microtime(tv);
815 		break;
816 	}
817 }
818 
819 void
820 evdev_client_push(struct evdev_client *client, uint16_t type, uint16_t code,
821     int32_t value)
822 {
823 	struct timeval time;
824 	size_t count, head, tail, ready;
825 
826 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
827 	head = client->ec_buffer_head;
828 	tail = client->ec_buffer_tail;
829 	ready = client->ec_buffer_ready;
830 	count = client->ec_buffer_size;
831 
832 	/* If queue is full drop its content and place SYN_DROPPED event */
833 	if ((tail + 1) % count == head) {
834 		debugf(client, "client %p: buffer overflow", client);
835 
836 		head = (tail + count - 1) % count;
837 		client->ec_buffer[head] = (struct input_event) {
838 			.type = EV_SYN,
839 			.code = SYN_DROPPED,
840 			.value = 0
841 		};
842 		/*
843 		 * XXX: Here is a small race window from now till the end of
844 		 *      report. The queue is empty but client has been already
845 		 *      notified of data readyness. Can be fixed in two ways:
846 		 * 1. Implement bulk insert so queue lock would not be dropped
847 		 *    till the SYN_REPORT event.
848 		 * 2. Insert SYN_REPORT just now and skip remaining events
849 		 */
850 		client->ec_buffer_head = head;
851 		client->ec_buffer_ready = head;
852 	}
853 
854 	client->ec_buffer[tail].type = type;
855 	client->ec_buffer[tail].code = code;
856 	client->ec_buffer[tail].value = value;
857 	client->ec_buffer_tail = (tail + 1) % count;
858 
859 	/* Allow users to read events only after report has been completed */
860 	if (type == EV_SYN && code == SYN_REPORT) {
861 		evdev_client_gettime(client, &time);
862 		for (; ready != client->ec_buffer_tail;
863 		    ready = (ready + 1) % count)
864 			client->ec_buffer[ready].time = time;
865 		client->ec_buffer_ready = client->ec_buffer_tail;
866 	}
867 }
868 
869 void
870 evdev_client_dumpqueue(struct evdev_client *client)
871 {
872 	struct input_event *event;
873 	size_t i, head, tail, ready, size;
874 
875 	head = client->ec_buffer_head;
876 	tail = client->ec_buffer_tail;
877 	ready = client->ec_buffer_ready;
878 	size = client->ec_buffer_size;
879 
880 	printf("evdev client: %p\n", client);
881 	printf("event queue: head=%zu ready=%zu tail=%zu size=%zu\n",
882 	    head, ready, tail, size);
883 
884 	printf("queue contents:\n");
885 
886 	for (i = 0; i < size; i++) {
887 		event = &client->ec_buffer[i];
888 		printf("%zu: ", i);
889 
890 		if (i < head || i > tail)
891 			printf("unused\n");
892 		else
893 			printf("type=%d code=%d value=%d ", event->type,
894 			    event->code, event->value);
895 
896 		if (i == head)
897 			printf("<- head\n");
898 		else if (i == tail)
899 			printf("<- tail\n");
900 		else if (i == ready)
901 			printf("<- ready\n");
902 		else
903 			printf("\n");
904 	}
905 }
906 
907 static void
908 evdev_client_filter_queue(struct evdev_client *client, uint16_t type)
909 {
910 	struct input_event *event;
911 	size_t head, tail, count, i;
912 	bool last_was_syn = false;
913 
914 	EVDEV_CLIENT_LOCKQ(client);
915 
916 	i = head = client->ec_buffer_head;
917 	tail = client->ec_buffer_tail;
918 	count = client->ec_buffer_size;
919 	client->ec_buffer_ready = client->ec_buffer_tail;
920 
921 	while (i != client->ec_buffer_tail) {
922 		event = &client->ec_buffer[i];
923 		i = (i + 1) % count;
924 
925 		/* Skip event of given type */
926 		if (event->type == type)
927 			continue;
928 
929 		/* Remove empty SYN_REPORT events */
930 		if (event->type == EV_SYN && event->code == SYN_REPORT) {
931 			if (last_was_syn)
932 				continue;
933 			else
934 				client->ec_buffer_ready = (tail + 1) % count;
935 		}
936 
937 		/* Rewrite entry */
938 		memcpy(&client->ec_buffer[tail], event,
939 		    sizeof(struct input_event));
940 
941 		last_was_syn = (event->type == EV_SYN &&
942 		    event->code == SYN_REPORT);
943 
944 		tail = (tail + 1) % count;
945 	}
946 
947 	client->ec_buffer_head = i;
948 	client->ec_buffer_tail = tail;
949 
950 	EVDEV_CLIENT_UNLOCKQ(client);
951 }
952