xref: /dragonfly/sys/dev/misc/evdev/cdev.c (revision a162a738)
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/types.h>
33 #include <sys/module.h>
34 #include <sys/devfs.h>
35 
36 #include <sys/param.h>
37 #include <sys/caps.h>
38 #include <sys/conf.h>
39 #include <sys/filio.h>
40 #include <sys/fcntl.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/poll.h>
44 #include <sys/proc.h>
45 #include <sys/systm.h>
46 #include <sys/time.h>
47 #include <sys/vnode.h> /* IO_NDELAY in read() */
48 #include <sys/uio.h>
49 
50 #include <sys/errno.h>
51 
52 #include <sys/device.h>
53 #include <sys/bus.h>
54 
55 /* Use FreeBSD bitstring locally. */
56 #include "freebsd-bitstring.h"
57 
58 #include <dev/misc/evdev/evdev.h>
59 #include <dev/misc/evdev/evdev_private.h>
60 #include <dev/misc/evdev/input.h>
61 
62 #ifdef EVDEV_DEBUG
63 #define	debugf(client, fmt, args...)	kprintf("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_kqfilter_t	evdev_kqfilter;
75 static d_priv_dtor_t	evdev_dtor;
76 
77 static int evdev_kqread(struct knote *kn, long hint);
78 static void evdev_kqdetach(struct knote *kn);
79 static int evdev_ioctl_eviocgbit(struct evdev_dev *, int, int, caddr_t);
80 static void evdev_client_filter_queue(struct evdev_client *, uint16_t);
81 
82 static struct dev_ops evdev_cdevsw = {
83 	{ "evdev", 0, 0 },
84 	.d_open = evdev_open,
85 	.d_read = evdev_read,
86 	.d_write = evdev_write,
87 	.d_ioctl = evdev_ioctl,
88 	.d_kqfilter = evdev_kqfilter,
89 };
90 
91 static struct filterops evdev_cdev_filterops = {
92 	.f_flags = FILTEROP_ISFD,
93 	.f_attach = NULL,
94 	.f_detach = evdev_kqdetach,
95 	.f_event = evdev_kqread,
96 };
97 
98 static int
evdev_open(struct dev_open_args * ap)99 evdev_open(struct dev_open_args *ap)
100 {
101 	cdev_t dev = ap->a_head.a_dev;
102 	struct evdev_dev *evdev = dev->si_drv1;
103 	struct evdev_client *client;
104 	size_t buffer_size;
105 	int ret;
106 
107 	/*
108 	 * Disallow access to disk volumes if RESTRICTEDROOT
109 	 */
110 	if (caps_priv_check_self(SYSCAP_RESTRICTEDROOT))
111 		return (EPERM);
112 
113 	if (evdev == NULL)
114 		return (ENODEV);
115 
116 	/* Initialize client structure */
117 	buffer_size = evdev->ev_report_size * DEF_RING_REPORTS;
118 	client = kmalloc(offsetof(struct evdev_client, ec_buffer) +
119 	    sizeof(struct input_event) * buffer_size,
120 	    M_EVDEV, M_WAITOK | M_ZERO);
121 
122 	/* Initialize ring buffer */
123 	client->ec_buffer_size = buffer_size;
124 	client->ec_buffer_head = 0;
125 	client->ec_buffer_tail = 0;
126 	client->ec_buffer_ready = 0;
127 
128 	client->ec_evdev = evdev;
129 	lockinit(&client->ec_buffer_mtx, "evclient", 0, LK_CANRECURSE);
130 
131 	/* Avoid race with evdev_unregister */
132 	EVDEV_LOCK(evdev);
133 	if (dev->si_drv1 == NULL)
134 		ret = ENODEV;
135 	else
136 		ret = evdev_register_client(evdev, client);
137 
138 	if (ret != 0)
139 		evdev_revoke_client(client);
140 	/*
141 	 * Unlock evdev here because non-sleepable lock held
142 	 * while calling devfs_set_cdevpriv upsets WITNESS
143 	 */
144 	EVDEV_UNLOCK(evdev);
145 
146 	if (ret == 0) {
147 		struct file *fp;
148 
149 		fp = (ap->a_fpp) ? *ap->a_fpp : NULL;
150 		ret = devfs_set_cdevpriv(fp, client, &evdev_dtor);
151 	}
152 
153 	if (ret != 0) {
154 		debugf(client, "cannot register evdev client");
155 	}
156 
157 	return (ret);
158 }
159 
160 static void
evdev_dtor(void * data)161 evdev_dtor(void *data)
162 {
163 	struct evdev_client *client = (struct evdev_client *)data;
164 
165 	EVDEV_LOCK(client->ec_evdev);
166 	if (!client->ec_revoked)
167 		evdev_dispose_client(client->ec_evdev, client);
168 	EVDEV_UNLOCK(client->ec_evdev);
169 
170 	funsetown(&client->ec_sigio);
171 	lockuninit(&client->ec_buffer_mtx);
172 	kfree(client, M_EVDEV);
173 }
174 
175 static int
evdev_read(struct dev_read_args * ap)176 evdev_read(struct dev_read_args *ap)
177 {
178 	struct uio *uio = ap->a_uio;
179 	int ioflag = ap->a_ioflag;
180 	struct evdev_client *client;
181 	struct input_event event;
182 	int ret = 0;
183 	int remaining;
184 
185 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
186 	if (ret != 0)
187 		return (ret);
188 
189 	debugf(client, "read %zd bytes by thread %d", uio->uio_resid, 0);
190 
191 	if (client->ec_revoked)
192 		return (ENODEV);
193 
194 	/* Zero-sized reads are allowed for error checking */
195 	if (uio->uio_resid != 0 && uio->uio_resid < sizeof(struct input_event))
196 		return (EINVAL);
197 
198 	remaining = uio->uio_resid / sizeof(struct input_event);
199 
200 	EVDEV_CLIENT_LOCKQ(client);
201 
202 	if (EVDEV_CLIENT_EMPTYQ(client)) {
203 		if (ioflag & IO_NDELAY) {
204 			ret = EWOULDBLOCK;
205 		} else {
206 			if (remaining != 0) {
207 				client->ec_blocked = true;
208 				ret = lksleep(client, &client->ec_buffer_mtx,
209 				    PCATCH, "evread", 0);
210 				if (ret == 0 && client->ec_revoked)
211 					ret = ENODEV;
212 			}
213 		}
214 	}
215 
216 	while (ret == 0 && !EVDEV_CLIENT_EMPTYQ(client) && remaining > 0) {
217 		memcpy(&event, &client->ec_buffer[client->ec_buffer_head],
218 		    sizeof(struct input_event));
219 		client->ec_buffer_head =
220 		    (client->ec_buffer_head + 1) % client->ec_buffer_size;
221 		remaining--;
222 
223 		EVDEV_CLIENT_UNLOCKQ(client);
224 		ret = uiomove((void *)&event, sizeof(struct input_event), uio);
225 		EVDEV_CLIENT_LOCKQ(client);
226 	}
227 
228 	EVDEV_CLIENT_UNLOCKQ(client);
229 
230 	return (ret);
231 }
232 
233 static int
evdev_write(struct dev_write_args * ap)234 evdev_write(struct dev_write_args *ap)
235 {
236 	cdev_t dev = ap->a_head.a_dev;
237 	struct uio *uio = ap->a_uio;
238 	struct evdev_dev *evdev = dev->si_drv1;
239 	struct evdev_client *client;
240 	struct input_event event;
241 	int ret = 0;
242 
243 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
244 	if (ret != 0)
245 		return (ret);
246 
247 	debugf(client, "write %zd bytes by thread %d", uio->uio_resid, 0);
248 
249 	if (client->ec_revoked || evdev == NULL)
250 		return (ENODEV);
251 
252 	if (uio->uio_resid % sizeof(struct input_event) != 0) {
253 		debugf(client, "write size not multiple of input_event size");
254 		return (EINVAL);
255 	}
256 
257 	while (uio->uio_resid > 0 && ret == 0) {
258 		ret = uiomove((void *)&event, sizeof(struct input_event), uio);
259 		if (ret == 0)
260 			ret = evdev_inject_event(evdev, event.type, event.code,
261 			    event.value);
262 	}
263 
264 	return (ret);
265 }
266 
267 static int
evdev_kqfilter(struct dev_kqfilter_args * ap)268 evdev_kqfilter(struct dev_kqfilter_args *ap)
269 {
270 	struct knote *kn = ap->a_kn;
271 	struct klist *klist;
272 	struct evdev_client *client;
273 	int ret;
274 
275 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
276 	if (ret != 0)
277 		return (ret);
278 
279 	if (client->ec_revoked)
280 		return (ENODEV);
281 
282 	switch(kn->kn_filter) {
283 	case EVFILT_READ:
284 		kn->kn_fop = &evdev_cdev_filterops;
285 		break;
286 	default:
287 		return(EINVAL);
288 	}
289 	kn->kn_hook = (caddr_t)client;
290 
291 	klist = &client->kqinfo.ki_note;
292 	knote_insert(klist, kn);
293 	return (0);
294 }
295 
296 static int
evdev_kqread(struct knote * kn,long hint)297 evdev_kqread(struct knote *kn, long hint)
298 {
299 	struct evdev_client *client;
300 	int ret;
301 	int locked = 0;
302 
303 	client = (struct evdev_client *)kn->kn_hook;
304 
305 	/* NOTE on DragonFly v FreeBSD.
306 	 * FreeBSD locks the klist when calling f_event, i.e. evdev_kqread().
307 	 * That's why the plain assertion EVDEV_CLIENT_LOCKQ_ASSERT(client)
308 	 * fails on DragonFly: DragonFly does not ensure the lock associated
309 	 * with the klist is locked.
310 	 * To mimic FreeBSD's behavior, we will lock ec_buffer_mtx if
311 	 * it was not locked, and unlock when leaving.
312 	 */
313 	locked = lockowned(&(client)->ec_buffer_mtx);
314 	if (!locked)
315 		EVDEV_CLIENT_LOCKQ(client);
316 
317 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
318 
319 	if (client->ec_revoked) {
320 		kn->kn_flags |= EV_EOF;
321 		ret = 1;
322 	} else {
323 		kn->kn_data = EVDEV_CLIENT_SIZEQ(client) *
324 		    sizeof(struct input_event);
325 		ret = !EVDEV_CLIENT_EMPTYQ(client);
326 	}
327 
328 	/* Unlock if ec_buffer_mtx was not locked. */
329 	if (!locked) {
330 		EVDEV_CLIENT_UNLOCKQ(client);
331 	}
332 
333 	return (ret);
334 }
335 
336 static void
evdev_kqdetach(struct knote * kn)337 evdev_kqdetach(struct knote *kn)
338 {
339 	struct evdev_client *client;
340 
341 	client = (struct evdev_client *)kn->kn_hook;
342 	knote_remove(&client->kqinfo.ki_note, kn);
343 }
344 
345 static int
evdev_ioctl(struct dev_ioctl_args * ap)346 evdev_ioctl(struct dev_ioctl_args *ap)
347 {
348 	cdev_t dev = ap->a_head.a_dev;
349 	u_long cmd = ap->a_cmd;
350 	caddr_t data = ap->a_data;
351 	struct evdev_dev *evdev = dev->si_drv1;
352 	struct evdev_client *client;
353 	struct input_keymap_entry *ke;
354 	int ret, len, limit, type_num;
355 	uint32_t code;
356 	size_t nvalues;
357 
358 	ret = devfs_get_cdevpriv(ap->a_fp, (void **)&client);
359 	if (ret != 0)
360 		return (ret);
361 
362 	if (client->ec_revoked || evdev == NULL)
363 		return (ENODEV);
364 
365 	/* file I/O ioctl handling */
366 	switch (cmd) {
367 	case FIOSETOWN:
368 		return (fsetown(*(int *)data, &client->ec_sigio));
369 
370 	case FIOGETOWN:
371 		*(int *)data = fgetown(&client->ec_sigio);
372 		return (0);
373 
374 	case FIONBIO:
375 		return (0);
376 
377 	case FIOASYNC:
378 		if (*(int *)data)
379 			client->ec_async = true;
380 		else
381 			client->ec_async = false;
382 
383 		return (0);
384 
385 	case FIONREAD:
386 		EVDEV_CLIENT_LOCKQ(client);
387 		*(int *)data =
388 		    EVDEV_CLIENT_SIZEQ(client) * sizeof(struct input_event);
389 		EVDEV_CLIENT_UNLOCKQ(client);
390 		return (0);
391 	}
392 
393 	len = IOCPARM_LEN(cmd);
394 	debugf(client, "ioctl called: cmd=0x%08lx, data=%p", cmd, data);
395 
396 	/* evdev fixed-length ioctls handling */
397 	switch (cmd) {
398 	case EVIOCGVERSION:
399 		*(int *)data = EV_VERSION;
400 		return (0);
401 
402 	case EVIOCGID:
403 		debugf(client, "EVIOCGID: bus=%d vendor=0x%04x product=0x%04x",
404 		    evdev->ev_id.bustype, evdev->ev_id.vendor,
405 		    evdev->ev_id.product);
406 		memcpy(data, &evdev->ev_id, sizeof(struct input_id));
407 		return (0);
408 
409 	case EVIOCGREP:
410 		if (!evdev_event_supported(evdev, EV_REP))
411 			return (ENOTSUP);
412 
413 		memcpy(data, evdev->ev_rep, sizeof(evdev->ev_rep));
414 		return (0);
415 
416 	case EVIOCSREP:
417 		if (!evdev_event_supported(evdev, EV_REP))
418 			return (ENOTSUP);
419 
420 		evdev_inject_event(evdev, EV_REP, REP_DELAY, ((int *)data)[0]);
421 		evdev_inject_event(evdev, EV_REP, REP_PERIOD,
422 		    ((int *)data)[1]);
423 		return (0);
424 
425 	case EVIOCGKEYCODE:
426 		/* Fake unsupported ioctl */
427 		return (0);
428 
429 	case EVIOCGKEYCODE_V2:
430 		if (evdev->ev_methods == NULL ||
431 		    evdev->ev_methods->ev_get_keycode == NULL)
432 			return (ENOTSUP);
433 
434 		ke = (struct input_keymap_entry *)data;
435 		evdev->ev_methods->ev_get_keycode(evdev, ke);
436 		return (0);
437 
438 	case EVIOCSKEYCODE:
439 		/* Fake unsupported ioctl */
440 		return (0);
441 
442 	case EVIOCSKEYCODE_V2:
443 		if (evdev->ev_methods == NULL ||
444 		    evdev->ev_methods->ev_set_keycode == NULL)
445 			return (ENOTSUP);
446 
447 		ke = (struct input_keymap_entry *)data;
448 		evdev->ev_methods->ev_set_keycode(evdev, ke);
449 		return (0);
450 
451 	case EVIOCGABS(0) ... EVIOCGABS(ABS_MAX):
452 		if (evdev->ev_absinfo == NULL)
453 			return (EINVAL);
454 
455 		memcpy(data, &evdev->ev_absinfo[cmd - EVIOCGABS(0)],
456 		    sizeof(struct input_absinfo));
457 		return (0);
458 
459 	case EVIOCSABS(0) ... EVIOCSABS(ABS_MAX):
460 		if (evdev->ev_absinfo == NULL)
461 			return (EINVAL);
462 
463 		code = cmd - EVIOCSABS(0);
464 		/* mt-slot number can not be changed */
465 		if (code == ABS_MT_SLOT)
466 			return (EINVAL);
467 
468 		EVDEV_LOCK(evdev);
469 		evdev_set_absinfo(evdev, code, (struct input_absinfo *)data);
470 		EVDEV_UNLOCK(evdev);
471 		return (0);
472 
473 	case EVIOCSFF:
474 	case EVIOCRMFF:
475 	case EVIOCGEFFECTS:
476 		/* Fake unsupported ioctls */
477 		return (0);
478 
479 	case EVIOCGRAB:
480 		EVDEV_LOCK(evdev);
481 		if (*(int *)data)
482 			ret = evdev_grab_client(evdev, client);
483 		else
484 			ret = evdev_release_client(evdev, client);
485 		EVDEV_UNLOCK(evdev);
486 		return (ret);
487 
488 	case EVIOCREVOKE:
489 		if (*(int *)data != 0)
490 			return (EINVAL);
491 
492 		EVDEV_LOCK(evdev);
493 		if (dev->si_drv1 != NULL && !client->ec_revoked) {
494 			evdev_dispose_client(evdev, client);
495 			evdev_revoke_client(client);
496 		}
497 		EVDEV_UNLOCK(evdev);
498 		return (0);
499 
500 	case EVIOCSCLOCKID:
501 		switch (*(int *)data) {
502 		case CLOCK_REALTIME:
503 			client->ec_clock_id = EV_CLOCK_REALTIME;
504 			return (0);
505 		case CLOCK_MONOTONIC:
506 			client->ec_clock_id = EV_CLOCK_MONOTONIC;
507 			return (0);
508 		default:
509 			return (EINVAL);
510 		}
511 	}
512 
513 	/* evdev variable-length ioctls handling */
514 	switch (IOCBASECMD(cmd)) {
515 	case EVIOCGNAME(0):
516 		strlcpy(data, evdev->ev_name, len);
517 		return (0);
518 
519 	case EVIOCGPHYS(0):
520 		if (evdev->ev_shortname[0] == 0)
521 			return (ENOENT);
522 
523 		strlcpy(data, evdev->ev_shortname, len);
524 		return (0);
525 
526 	case EVIOCGUNIQ(0):
527 		if (evdev->ev_serial[0] == 0)
528 			return (ENOENT);
529 
530 		strlcpy(data, evdev->ev_serial, len);
531 		return (0);
532 
533 	case EVIOCGPROP(0):
534 		limit = MIN(len, bitstr_size(INPUT_PROP_CNT));
535 		memcpy(data, evdev->ev_prop_flags, limit);
536 		return (0);
537 
538 	case EVIOCGMTSLOTS(0):
539 		if (evdev->ev_mt == NULL)
540 			return (EINVAL);
541 		if (len < sizeof(uint32_t))
542 			return (EINVAL);
543 		code = *(uint32_t *)data;
544 		if (!ABS_IS_MT(code))
545 			return (EINVAL);
546 
547 		nvalues =
548 		    MIN(len / sizeof(int32_t) - 1, MAXIMAL_MT_SLOT(evdev) + 1);
549 		for (int i = 0; i < nvalues; i++)
550 			((int32_t *)data)[i + 1] =
551 			    evdev_mt_get_value(evdev, i, code);
552 		return (0);
553 
554 	case EVIOCGKEY(0):
555 		limit = MIN(len, bitstr_size(KEY_CNT));
556 		EVDEV_LOCK(evdev);
557 		evdev_client_filter_queue(client, EV_KEY);
558 		memcpy(data, evdev->ev_key_states, limit);
559 		EVDEV_UNLOCK(evdev);
560 		return (0);
561 
562 	case EVIOCGLED(0):
563 		limit = MIN(len, bitstr_size(LED_CNT));
564 		EVDEV_LOCK(evdev);
565 		evdev_client_filter_queue(client, EV_LED);
566 		memcpy(data, evdev->ev_led_states, limit);
567 		EVDEV_UNLOCK(evdev);
568 		return (0);
569 
570 	case EVIOCGSND(0):
571 		limit = MIN(len, bitstr_size(SND_CNT));
572 		EVDEV_LOCK(evdev);
573 		evdev_client_filter_queue(client, EV_SND);
574 		memcpy(data, evdev->ev_snd_states, limit);
575 		EVDEV_UNLOCK(evdev);
576 		return (0);
577 
578 	case EVIOCGSW(0):
579 		limit = MIN(len, bitstr_size(SW_CNT));
580 		EVDEV_LOCK(evdev);
581 		evdev_client_filter_queue(client, EV_SW);
582 		memcpy(data, evdev->ev_sw_states, limit);
583 		EVDEV_UNLOCK(evdev);
584 		return (0);
585 
586 	case EVIOCGBIT(0, 0) ... EVIOCGBIT(EV_MAX, 0):
587 		type_num = IOCBASECMD(cmd) - EVIOCGBIT(0, 0);
588 		debugf(client, "EVIOCGBIT(%d): data=%p, len=%d", type_num,
589 		    data, len);
590 		return (evdev_ioctl_eviocgbit(evdev, type_num, len, data));
591 	}
592 
593 	return (EINVAL);
594 }
595 
596 static int
evdev_ioctl_eviocgbit(struct evdev_dev * evdev,int type,int len,caddr_t data)597 evdev_ioctl_eviocgbit(struct evdev_dev *evdev, int type, int len, caddr_t data)
598 {
599 	/*
600 	 * We will use freebsd-bitstring.h locally. This ensures bitmap
601 	 * is of type (unsigned long *). DragonFly's original bitmap
602 	 * is (unsigned char *).
603 	 */
604 	unsigned long *bitmap;
605 	int limit;
606 
607 	switch (type) {
608 	case 0:
609 		bitmap = evdev->ev_type_flags;
610 		limit = EV_CNT;
611 		break;
612 	case EV_KEY:
613 		bitmap = evdev->ev_key_flags;
614 		limit = KEY_CNT;
615 		break;
616 	case EV_REL:
617 		bitmap = evdev->ev_rel_flags;
618 		limit = REL_CNT;
619 		break;
620 	case EV_ABS:
621 		bitmap = evdev->ev_abs_flags;
622 		limit = ABS_CNT;
623 		break;
624 	case EV_MSC:
625 		bitmap = evdev->ev_msc_flags;
626 		limit = MSC_CNT;
627 		break;
628 	case EV_LED:
629 		bitmap = evdev->ev_led_flags;
630 		limit = LED_CNT;
631 		break;
632 	case EV_SND:
633 		bitmap = evdev->ev_snd_flags;
634 		limit = SND_CNT;
635 		break;
636 	case EV_SW:
637 		bitmap = evdev->ev_sw_flags;
638 		limit = SW_CNT;
639 		break;
640 	case EV_FF:
641 		/*
642 		 * We don't support EV_FF now, so let's
643 		 * just fake it returning only zeros.
644 		 */
645 		bzero(data, len);
646 		return (0);
647 	default:
648 		return (ENOTTY);
649 	}
650 
651 	/*
652 	 * Clear ioctl data buffer in case it's bigger than
653 	 * bitmap size
654 	 */
655 	bzero(data, len);
656 
657 	limit = bitstr_size(limit);
658 	len = MIN(limit, len);
659 	memcpy(data, bitmap, len);
660 	return (0);
661 }
662 
663 void
evdev_revoke_client(struct evdev_client * client)664 evdev_revoke_client(struct evdev_client *client)
665 {
666 
667 	EVDEV_LOCK_ASSERT(client->ec_evdev);
668 
669 	client->ec_revoked = true;
670 }
671 
672 void
evdev_notify_event(struct evdev_client * client)673 evdev_notify_event(struct evdev_client *client)
674 {
675 
676 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
677 
678 	if (client->ec_blocked) {
679 		client->ec_blocked = false;
680 		wakeup(client);
681 	}
682 	if (client->ec_selected) {
683 		client->ec_selected = false;
684 		wakeup(&client->kqinfo);
685 	}
686 
687 	KNOTE(&client->kqinfo.ki_note, 0);
688 
689 	if (client->ec_async && client->ec_sigio != NULL)
690 		pgsigio(client->ec_sigio, SIGIO, 0);
691 }
692 
693 int
evdev_cdev_create(struct evdev_dev * evdev)694 evdev_cdev_create(struct evdev_dev *evdev)
695 {
696 	cdev_t dev;
697 	int ret, unit;
698 
699 	/*
700 	 * Iterate over devices input/eventX until we find a non-existing
701 	 * one and record its number in unit.
702 	 */
703 	unit = 0;
704 	while (devfs_find_device_by_name("input/event%d", unit) != NULL) {
705 	    unit++;
706 	}
707 
708 	/*
709 	 * Put unit as minor. Minor and major will determine st_rdev of
710 	 * eventX. Ensuring that all eventX have different major and minor
711 	 * will make st_rdev unique. This is needed by libinput, which
712 	 * determines eventX from st_rdev.
713 	 */
714 	dev = make_dev(&evdev_cdevsw, unit, UID_ROOT, GID_WHEEL, 0600,
715 	    "input/event%d", unit);
716 
717 	if (dev != NULL) {
718 		dev->si_drv1 = evdev;
719 		evdev->ev_cdev = dev;
720 		evdev->ev_unit = unit;
721 		ret = 0;
722 	} else {
723 		ret = ENODEV;
724 		goto err;
725 	}
726 
727 	reference_dev(evdev->ev_cdev);
728 
729 err:
730 	return (ret);
731 }
732 
733 int
evdev_cdev_destroy(struct evdev_dev * evdev)734 evdev_cdev_destroy(struct evdev_dev *evdev)
735 {
736 
737 	if (evdev->ev_cdev) {
738 		dev_ops_remove_minor(&evdev_cdevsw, evdev->ev_unit);
739 	}
740 
741 	return (0);
742 }
743 
744 static void
evdev_client_gettime(struct evdev_client * client,struct timeval * tv)745 evdev_client_gettime(struct evdev_client *client, struct timeval *tv)
746 {
747 
748 	switch (client->ec_clock_id) {
749 	case EV_CLOCK_BOOTTIME:
750 		/*
751 		 * XXX: FreeBSD does not support true POSIX monotonic clock.
752 		 *      So aliase EV_CLOCK_BOOTTIME to EV_CLOCK_MONOTONIC.
753 		 */
754 	case EV_CLOCK_MONOTONIC:
755 		microuptime(tv);
756 		break;
757 
758 	case EV_CLOCK_REALTIME:
759 	default:
760 		microtime(tv);
761 		break;
762 	}
763 }
764 
765 void
evdev_client_push(struct evdev_client * client,uint16_t type,uint16_t code,int32_t value)766 evdev_client_push(struct evdev_client *client, uint16_t type, uint16_t code,
767     int32_t value)
768 {
769 	struct timeval time;
770 	size_t count, head, tail, ready;
771 
772 	EVDEV_CLIENT_LOCKQ_ASSERT(client);
773 	head = client->ec_buffer_head;
774 	tail = client->ec_buffer_tail;
775 	ready = client->ec_buffer_ready;
776 	count = client->ec_buffer_size;
777 
778 	/* If queue is full drop its content and place SYN_DROPPED event */
779 	if ((tail + 1) % count == head) {
780 		debugf(client, "client %p: buffer overflow", client);
781 
782 		head = (tail + count - 1) % count;
783 		client->ec_buffer[head] = (struct input_event) {
784 			.type = EV_SYN,
785 			.code = SYN_DROPPED,
786 			.value = 0
787 		};
788 		/*
789 		 * XXX: Here is a small race window from now till the end of
790 		 *      report. The queue is empty but client has been already
791 		 *      notified of data readyness. Can be fixed in two ways:
792 		 * 1. Implement bulk insert so queue lock would not be dropped
793 		 *    till the SYN_REPORT event.
794 		 * 2. Insert SYN_REPORT just now and skip remaining events
795 		 */
796 		client->ec_buffer_head = head;
797 		client->ec_buffer_ready = head;
798 	}
799 
800 	client->ec_buffer[tail].type = type;
801 	client->ec_buffer[tail].code = code;
802 	client->ec_buffer[tail].value = value;
803 	client->ec_buffer_tail = (tail + 1) % count;
804 
805 	/* Allow users to read events only after report has been completed */
806 	if (type == EV_SYN && code == SYN_REPORT) {
807 		evdev_client_gettime(client, &time);
808 		for (; ready != client->ec_buffer_tail;
809 		    ready = (ready + 1) % count)
810 			client->ec_buffer[ready].time = time;
811 		client->ec_buffer_ready = client->ec_buffer_tail;
812 	}
813 }
814 
815 void
evdev_client_dumpqueue(struct evdev_client * client)816 evdev_client_dumpqueue(struct evdev_client *client)
817 {
818 	struct input_event *event;
819 	size_t i, head, tail, ready, size;
820 
821 	head = client->ec_buffer_head;
822 	tail = client->ec_buffer_tail;
823 	ready = client->ec_buffer_ready;
824 	size = client->ec_buffer_size;
825 
826 	kprintf("evdev client: %p\n", client);
827 	kprintf("event queue: head=%zu ready=%zu tail=%zu size=%zu\n",
828 	    head, ready, tail, size);
829 
830 	kprintf("queue contents:\n");
831 
832 	for (i = 0; i < size; i++) {
833 		event = &client->ec_buffer[i];
834 		kprintf("%zu: ", i);
835 
836 		if (i < head || i > tail)
837 			kprintf("unused\n");
838 		else
839 			kprintf("type=%d code=%d value=%d ", event->type,
840 			    event->code, event->value);
841 
842 		if (i == head)
843 			kprintf("<- head\n");
844 		else if (i == tail)
845 			kprintf("<- tail\n");
846 		else if (i == ready)
847 			kprintf("<- ready\n");
848 		else
849 			kprintf("\n");
850 	}
851 }
852 
853 static void
evdev_client_filter_queue(struct evdev_client * client,uint16_t type)854 evdev_client_filter_queue(struct evdev_client *client, uint16_t type)
855 {
856 	struct input_event *event;
857 	size_t head, tail, count, i;
858 	bool last_was_syn = false;
859 
860 	EVDEV_CLIENT_LOCKQ(client);
861 
862 	i = head = client->ec_buffer_head;
863 	tail = client->ec_buffer_tail;
864 	count = client->ec_buffer_size;
865 	client->ec_buffer_ready = client->ec_buffer_tail;
866 
867 	while (i != client->ec_buffer_tail) {
868 		event = &client->ec_buffer[i];
869 		i = (i + 1) % count;
870 
871 		/* Skip event of given type */
872 		if (event->type == type)
873 			continue;
874 
875 		/* Remove empty SYN_REPORT events */
876 		if (event->type == EV_SYN && event->code == SYN_REPORT) {
877 			if (last_was_syn)
878 				continue;
879 			else
880 				client->ec_buffer_ready = (tail + 1) % count;
881 		}
882 
883 		/* Rewrite entry */
884 		memcpy(&client->ec_buffer[tail], event,
885 		    sizeof(struct input_event));
886 
887 		last_was_syn = (event->type == EV_SYN &&
888 		    event->code == SYN_REPORT);
889 
890 		tail = (tail + 1) % count;
891 	}
892 
893 	client->ec_buffer_head = i;
894 	client->ec_buffer_tail = tail;
895 
896 	EVDEV_CLIENT_UNLOCKQ(client);
897 }
898