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1 /*	$NetBSD: hid.c,v 1.17 2001/11/13 06:24:53 lukem Exp $	*/
2 /*-
3  * SPDX-License-Identifier: BSD-2-Clause
4  *
5  * Copyright (c) 1998 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Lennart Augustsson (lennart@augustsson.net) at
10  * Carlstedt Research & Technology.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "implementation/global_implementation.h"
35 #include "input/usb_rdesc.h"
36 
37 #ifndef nitems
38 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
39 #endif
40 
41 #undef USB_DEBUG_VAR
42 #define	USB_DEBUG_VAR usb_debug
43 
44 static void hid_clear_local(struct hid_item *);
45 static uint8_t hid_get_byte(struct hid_data *s, const uint16_t wSize);
46 
47 #define	MAXUSAGE 64
48 #define	MAXPUSH 4
49 #define	MAXID 16
50 #define	MAXLOCCNT 1024
51 
52 struct hid_pos_data {
53 	int32_t rid;
54 	uint32_t pos;
55 };
56 
57 struct hid_data {
58 	const uint8_t *start;
59 	const uint8_t *end;
60 	const uint8_t *p;
61 	struct hid_item cur[MAXPUSH];
62 	struct hid_pos_data last_pos[MAXID];
63 	int32_t	usages_min[MAXUSAGE];
64 	int32_t	usages_max[MAXUSAGE];
65 	int32_t usage_last;	/* last seen usage */
66 	uint32_t loc_size;	/* last seen size */
67 	uint32_t loc_count;	/* last seen count */
68 	uint32_t ncount;	/* end usage item count */
69 	uint32_t icount;	/* current usage item count */
70 	uint8_t	kindset;	/* we have 5 kinds so 8 bits are enough */
71 	uint8_t	pushlevel;	/* current pushlevel */
72 	uint8_t	nusage;		/* end "usages_min/max" index */
73 	uint8_t	iusage;		/* current "usages_min/max" index */
74 	uint8_t ousage;		/* current "usages_min/max" offset */
75 	uint8_t	susage;		/* usage set flags */
76 };
77 
78 /*------------------------------------------------------------------------*
79  *	hid_clear_local
80  *------------------------------------------------------------------------*/
81 static void
hid_clear_local(struct hid_item * c)82 hid_clear_local(struct hid_item *c)
83 {
84 
85 	c->loc.count = 0;
86 	c->loc.size = 0;
87 	c->usage = 0;
88 	c->usage_minimum = 0;
89 	c->usage_maximum = 0;
90 	c->designator_index = 0;
91 	c->designator_minimum = 0;
92 	c->designator_maximum = 0;
93 	c->string_index = 0;
94 	c->string_minimum = 0;
95 	c->string_maximum = 0;
96 	c->set_delimiter = 0;
97 }
98 
99 static void
hid_switch_rid(struct hid_data * s,struct hid_item * c,int32_t next_rID)100 hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
101 {
102 	uint8_t i;
103 
104 	/* check for same report ID - optimise */
105 
106 	if (c->report_ID == next_rID)
107 		return;
108 
109 	/* save current position for current rID */
110 
111 	if (c->report_ID == 0) {
112 		i = 0;
113 	} else {
114 		for (i = 1; i != MAXID; i++) {
115 			if (s->last_pos[i].rid == c->report_ID)
116 				break;
117 			if (s->last_pos[i].rid == 0)
118 				break;
119 		}
120 	}
121 	if (i != MAXID) {
122 		s->last_pos[i].rid = c->report_ID;
123 		s->last_pos[i].pos = c->loc.pos;
124 	}
125 
126 	/* store next report ID */
127 
128 	c->report_ID = next_rID;
129 
130 	/* lookup last position for next rID */
131 
132 	if (next_rID == 0) {
133 		i = 0;
134 	} else {
135 		for (i = 1; i != MAXID; i++) {
136 			if (s->last_pos[i].rid == next_rID)
137 				break;
138 			if (s->last_pos[i].rid == 0)
139 				break;
140 		}
141 	}
142 	if (i != MAXID) {
143 		s->last_pos[i].rid = next_rID;
144 		c->loc.pos = s->last_pos[i].pos;
145 	} else {
146 		DPRINTF("Out of RID entries, position is set to zero!\n");
147 		c->loc.pos = 0;
148 	}
149 }
150 
151 /*------------------------------------------------------------------------*
152  *	hid_start_parse
153  *------------------------------------------------------------------------*/
154 struct hid_data *
hid_start_parse(const void * d,usb_size_t len,int kindset)155 hid_start_parse(const void *d, usb_size_t len, int kindset)
156 {
157 	struct hid_data *s;
158 
159 	if ((kindset-1) & kindset) {
160 		DPRINTFN(0, "Only one bit can be "
161 		    "set in the kindset\n");
162 		return (NULL);
163 	}
164 
165 	s = zalloc(sizeof *s);
166 	if (s != NULL) {
167 		s->start = s->p = d;
168 		s->end = ((const uint8_t *)d) + len;
169 		s->kindset = kindset;
170 	}
171 
172 	return (s);
173 }
174 
175 /*------------------------------------------------------------------------*
176  *	hid_end_parse
177  *------------------------------------------------------------------------*/
178 void
hid_end_parse(struct hid_data * s)179 hid_end_parse(struct hid_data *s)
180 {
181 	if (s == NULL)
182 		return;
183 
184 	free(s);
185 }
186 
187 /*------------------------------------------------------------------------*
188  *	get byte from HID descriptor
189  *------------------------------------------------------------------------*/
190 static uint8_t
hid_get_byte(struct hid_data * s,const uint16_t wSize)191 hid_get_byte(struct hid_data *s, const uint16_t wSize)
192 {
193 	const uint8_t *ptr;
194 	uint8_t retval;
195 
196 	ptr = s->p;
197 
198 	/* check if end is reached */
199 	if (ptr == s->end)
200 		return (0);
201 
202 	/* read out a byte */
203 	retval = *ptr;
204 
205 	/* check if data pointer can be advanced by "wSize" bytes */
206 	if ((s->end - ptr) < wSize)
207 		ptr = s->end;
208 	else
209 		ptr += wSize;
210 
211 	/* update pointer */
212 	s->p = ptr;
213 
214 	return (retval);
215 }
216 
217 /*------------------------------------------------------------------------*
218  *	hid_get_item
219  *------------------------------------------------------------------------*/
220 int
hid_get_item(struct hid_data * s,struct hid_item * h)221 hid_get_item(struct hid_data *s, struct hid_item *h)
222 {
223 	struct hid_item *c;
224 	unsigned int bTag, bType, bSize;
225 	uint32_t oldpos;
226 	int32_t mask;
227 	int32_t dval;
228 
229 	if (s == NULL)
230 		return (0);
231 
232 	c = &s->cur[s->pushlevel];
233 
234  top:
235 	/* check if there is an array of items */
236 	if (s->icount < s->ncount) {
237 		/* get current usage */
238 		if (s->iusage < s->nusage) {
239 			dval = s->usages_min[s->iusage] + s->ousage;
240 			c->usage = dval;
241 			s->usage_last = dval;
242 			if (dval == s->usages_max[s->iusage]) {
243 				s->iusage ++;
244 				s->ousage = 0;
245 			} else {
246 				s->ousage ++;
247 			}
248 		} else {
249 			DPRINTFN(1, "Using last usage\n");
250 			dval = s->usage_last;
251 		}
252 		s->icount ++;
253 		/*
254 		 * Only copy HID item, increment position and return
255 		 * if correct kindset!
256 		 */
257 		if (s->kindset & (1 << c->kind)) {
258 			*h = *c;
259 			DPRINTFN(1, "%u,%u,%u\n", h->loc.pos,
260 			    h->loc.size, h->loc.count);
261 			c->loc.pos += c->loc.size * c->loc.count;
262 			return (1);
263 		}
264 	}
265 
266 	/* reset state variables */
267 	s->icount = 0;
268 	s->ncount = 0;
269 	s->iusage = 0;
270 	s->nusage = 0;
271 	s->susage = 0;
272 	s->ousage = 0;
273 	hid_clear_local(c);
274 
275 	/* get next item */
276 	while (s->p != s->end) {
277 
278 		bSize = hid_get_byte(s, 1);
279 		if (bSize == 0xfe) {
280 			/* long item */
281 			bSize = hid_get_byte(s, 1);
282 			bSize |= hid_get_byte(s, 1) << 8;
283 			bTag = hid_get_byte(s, 1);
284 			bType = 0xff;	/* XXX what should it be */
285 		} else {
286 			/* short item */
287 			bTag = bSize >> 4;
288 			bType = (bSize >> 2) & 3;
289 			bSize &= 3;
290 			if (bSize == 3)
291 				bSize = 4;
292 		}
293 		switch (bSize) {
294 		case 0:
295 			dval = 0;
296 			mask = 0;
297 			break;
298 		case 1:
299 			dval = (int8_t)hid_get_byte(s, 1);
300 			mask = 0xFF;
301 			break;
302 		case 2:
303 			dval = hid_get_byte(s, 1);
304 			dval |= hid_get_byte(s, 1) << 8;
305 			dval = (int16_t)dval;
306 			mask = 0xFFFF;
307 			break;
308 		case 4:
309 			dval = hid_get_byte(s, 1);
310 			dval |= hid_get_byte(s, 1) << 8;
311 			dval |= hid_get_byte(s, 1) << 16;
312 			dval |= hid_get_byte(s, 1) << 24;
313 			mask = 0xFFFFFFFF;
314 			break;
315 		default:
316 			dval = hid_get_byte(s, bSize);
317 			DPRINTFN(0, "bad length %u (data=0x%02x)\n",
318 			    bSize, dval);
319 			continue;
320 		}
321 
322 		switch (bType) {
323 		case 0:		/* Main */
324 			switch (bTag) {
325 			case 8:	/* Input */
326 				c->kind = hid_input;
327 		ret:
328 				c->flags = dval;
329 				c->loc.count = s->loc_count;
330 				c->loc.size = s->loc_size;
331 
332 				if (c->flags & HIO_VARIABLE) {
333 					/* range check usage count */
334 					if (c->loc.count > MAXLOCCNT) {
335 						DPRINTFN(0, "Number of "
336 						    "items(%u) truncated to %u\n",
337 						    (unsigned)(c->loc.count),
338 						    MAXLOCCNT);
339 						s->ncount = MAXLOCCNT;
340 					} else
341 						s->ncount = c->loc.count;
342 
343 					/*
344 					 * The "top" loop will return
345 					 * one and one item:
346 					 */
347 					c->loc.count = 1;
348 				} else {
349 					s->ncount = 1;
350 				}
351 				goto top;
352 
353 			case 9:	/* Output */
354 				c->kind = hid_output;
355 				goto ret;
356 			case 10:	/* Collection */
357 				c->kind = hid_collection;
358 				c->collection = dval;
359 				c->collevel++;
360 				c->usage = s->usage_last;
361 				*h = *c;
362 				return (1);
363 			case 11:	/* Feature */
364 				c->kind = hid_feature;
365 				goto ret;
366 			case 12:	/* End collection */
367 				c->kind = hid_endcollection;
368 				if (c->collevel == 0) {
369 					DPRINTFN(0, "invalid end collection\n");
370 					return (0);
371 				}
372 				c->collevel--;
373 				*h = *c;
374 				return (1);
375 			default:
376 				DPRINTFN(0, "Main bTag=%d\n", bTag);
377 				break;
378 			}
379 			break;
380 		case 1:		/* Global */
381 			switch (bTag) {
382 			case 0:
383 				c->_usage_page = dval << 16;
384 				break;
385 			case 1:
386 				c->logical_minimum = dval;
387 				break;
388 			case 2:
389 				c->logical_maximum = dval;
390 				break;
391 			case 3:
392 				c->physical_minimum = dval;
393 				break;
394 			case 4:
395 				c->physical_maximum = dval;
396 				break;
397 			case 5:
398 				c->unit_exponent = dval;
399 				break;
400 			case 6:
401 				c->unit = dval;
402 				break;
403 			case 7:
404 				/* mask because value is unsigned */
405 				s->loc_size = dval & mask;
406 				break;
407 			case 8:
408 				hid_switch_rid(s, c, dval & mask);
409 				break;
410 			case 9:
411 				/* mask because value is unsigned */
412 				s->loc_count = dval & mask;
413 				break;
414 			case 10:	/* Push */
415 				/* stop parsing, if invalid push level */
416 				if ((s->pushlevel + 1) >= MAXPUSH) {
417 					DPRINTFN(0, "Cannot push item @ %d\n", s->pushlevel);
418 					return (0);
419 				}
420 				s->pushlevel ++;
421 				s->cur[s->pushlevel] = *c;
422 				/* store size and count */
423 				c->loc.size = s->loc_size;
424 				c->loc.count = s->loc_count;
425 				/* update current item pointer */
426 				c = &s->cur[s->pushlevel];
427 				break;
428 			case 11:	/* Pop */
429 				/* stop parsing, if invalid push level */
430 				if (s->pushlevel == 0) {
431 					DPRINTFN(0, "Cannot pop item @ 0\n");
432 					return (0);
433 				}
434 				s->pushlevel --;
435 				/* preserve position */
436 				oldpos = c->loc.pos;
437 				c = &s->cur[s->pushlevel];
438 				/* restore size and count */
439 				s->loc_size = c->loc.size;
440 				s->loc_count = c->loc.count;
441 				/* set default item location */
442 				c->loc.pos = oldpos;
443 				c->loc.size = 0;
444 				c->loc.count = 0;
445 				break;
446 			default:
447 				DPRINTFN(0, "Global bTag=%d\n", bTag);
448 				break;
449 			}
450 			break;
451 		case 2:		/* Local */
452 			switch (bTag) {
453 			case 0:
454 				if (bSize != 4)
455 					dval = (dval & mask) | c->_usage_page;
456 
457 				/* set last usage, in case of a collection */
458 				s->usage_last = dval;
459 
460 				if (s->nusage < MAXUSAGE) {
461 					s->usages_min[s->nusage] = dval;
462 					s->usages_max[s->nusage] = dval;
463 					s->nusage ++;
464 				} else {
465 					DPRINTFN(0, "max usage reached\n");
466 				}
467 
468 				/* clear any pending usage sets */
469 				s->susage = 0;
470 				break;
471 			case 1:
472 				s->susage |= 1;
473 
474 				if (bSize != 4)
475 					dval = (dval & mask) | c->_usage_page;
476 				c->usage_minimum = dval;
477 
478 				goto check_set;
479 			case 2:
480 				s->susage |= 2;
481 
482 				if (bSize != 4)
483 					dval = (dval & mask) | c->_usage_page;
484 				c->usage_maximum = dval;
485 
486 			check_set:
487 				if (s->susage != 3)
488 					break;
489 
490 				/* sanity check */
491 				if ((s->nusage < MAXUSAGE) &&
492 				    (c->usage_minimum <= c->usage_maximum)) {
493 					/* add usage range */
494 					s->usages_min[s->nusage] =
495 					    c->usage_minimum;
496 					s->usages_max[s->nusage] =
497 					    c->usage_maximum;
498 					s->nusage ++;
499 				} else {
500 					DPRINTFN(0, "Usage set dropped\n");
501 				}
502 				s->susage = 0;
503 				break;
504 			case 3:
505 				c->designator_index = dval;
506 				break;
507 			case 4:
508 				c->designator_minimum = dval;
509 				break;
510 			case 5:
511 				c->designator_maximum = dval;
512 				break;
513 			case 7:
514 				c->string_index = dval;
515 				break;
516 			case 8:
517 				c->string_minimum = dval;
518 				break;
519 			case 9:
520 				c->string_maximum = dval;
521 				break;
522 			case 10:
523 				c->set_delimiter = dval;
524 				break;
525 			default:
526 				DPRINTFN(0, "Local bTag=%d\n", bTag);
527 				break;
528 			}
529 			break;
530 		default:
531 			DPRINTFN(0, "default bType=%d\n", bType);
532 			break;
533 		}
534 	}
535 	return (0);
536 }
537 
538 /*------------------------------------------------------------------------*
539  *	hid_report_size
540  *------------------------------------------------------------------------*/
541 int
hid_report_size(const void * buf,usb_size_t len,enum hid_kind k,uint8_t * id)542 hid_report_size(const void *buf, usb_size_t len, enum hid_kind k, uint8_t *id)
543 {
544 	struct hid_data *d;
545 	struct hid_item h;
546 	uint32_t temp;
547 	uint32_t hpos;
548 	uint32_t lpos;
549 	uint8_t any_id;
550 
551 	any_id = 0;
552 	hpos = 0;
553 	lpos = 0xFFFFFFFF;
554 
555 	for (d = hid_start_parse(buf, len, 1 << k); hid_get_item(d, &h);) {
556 		if (h.kind == k) {
557 			/* check for ID-byte presence */
558 			if ((h.report_ID != 0) && !any_id) {
559 				if (id != NULL)
560 					*id = h.report_ID;
561 				any_id = 1;
562 			}
563 			/* compute minimum */
564 			if (lpos > h.loc.pos)
565 				lpos = h.loc.pos;
566 			/* compute end position */
567 			temp = h.loc.pos + (h.loc.size * h.loc.count);
568 			/* compute maximum */
569 			if (hpos < temp)
570 				hpos = temp;
571 		}
572 	}
573 	hid_end_parse(d);
574 
575 	/* safety check - can happen in case of currupt descriptors */
576 	if (lpos > hpos)
577 		temp = 0;
578 	else
579 		temp = hpos - lpos;
580 
581 	/* check for ID byte */
582 	if (any_id)
583 		temp += 8;
584 	else if (id != NULL)
585 		*id = 0;
586 
587 	/* return length in bytes rounded up */
588 	return ((temp + 7) / 8);
589 }
590 
591 /*------------------------------------------------------------------------*
592  *	hid_locate
593  *------------------------------------------------------------------------*/
594 int
hid_locate(const void * desc,usb_size_t size,int32_t u,enum hid_kind k,uint8_t index,struct hid_location * loc,uint32_t * flags,uint8_t * id)595 hid_locate(const void *desc, usb_size_t size, int32_t u, enum hid_kind k,
596     uint8_t index, struct hid_location *loc, uint32_t *flags, uint8_t *id)
597 {
598 	struct hid_data *d;
599 	struct hid_item h;
600 
601 	for (d = hid_start_parse(desc, size, 1 << k); hid_get_item(d, &h);) {
602 		if (h.kind == k && !(h.flags & HIO_CONST) && h.usage == u) {
603 			if (index--)
604 				continue;
605 			if (loc != NULL)
606 				*loc = h.loc;
607 			if (flags != NULL)
608 				*flags = h.flags;
609 			if (id != NULL)
610 				*id = h.report_ID;
611 			hid_end_parse(d);
612 			return (1);
613 		}
614 	}
615 	if (loc != NULL)
616 		loc->size = 0;
617 	if (flags != NULL)
618 		*flags = 0;
619 	if (id != NULL)
620 		*id = 0;
621 	hid_end_parse(d);
622 	return (0);
623 }
624 
625 /*------------------------------------------------------------------------*
626  *	hid_get_data
627  *------------------------------------------------------------------------*/
628 static uint32_t
hid_get_data_sub(const uint8_t * buf,usb_size_t len,struct hid_location * loc,int is_signed)629 hid_get_data_sub(const uint8_t *buf, usb_size_t len, struct hid_location *loc,
630     int is_signed)
631 {
632 	uint32_t hpos = loc->pos;
633 	uint32_t hsize = loc->size;
634 	uint32_t data;
635 	uint32_t rpos;
636 	uint8_t n;
637 
638 	DPRINTFN(11, "hid_get_data: loc %d/%d\n", hpos, hsize);
639 
640 	/* Range check and limit */
641 	if (hsize == 0)
642 		return (0);
643 	if (hsize > 32)
644 		hsize = 32;
645 
646 	/* Get data in a safe way */
647 	data = 0;
648 	rpos = (hpos / 8);
649 	n = (hsize + 7) / 8;
650 	rpos += n;
651 	while (n--) {
652 		rpos--;
653 		if (rpos < len)
654 			data |= buf[rpos] << (8 * n);
655 	}
656 
657 	/* Correctly shift down data */
658 	data = (data >> (hpos % 8));
659 	n = 32 - hsize;
660 
661 	/* Mask and sign extend in one */
662 	if (is_signed != 0)
663 		data = (int32_t)((int32_t)data << n) >> n;
664 	else
665 		data = (uint32_t)((uint32_t)data << n) >> n;
666 
667 	DPRINTFN(11, "hid_get_data: loc %d/%d = %lu\n",
668 	    loc->pos, loc->size, (long)data);
669 	return (data);
670 }
671 
672 int32_t
hid_get_data(const uint8_t * buf,usb_size_t len,struct hid_location * loc)673 hid_get_data(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
674 {
675 	return (hid_get_data_sub(buf, len, loc, 1));
676 }
677 
678 uint32_t
hid_get_data_unsigned(const uint8_t * buf,usb_size_t len,struct hid_location * loc)679 hid_get_data_unsigned(const uint8_t *buf, usb_size_t len, struct hid_location *loc)
680 {
681         return (hid_get_data_sub(buf, len, loc, 0));
682 }
683 
684 /*------------------------------------------------------------------------*
685  *	hid_put_data
686  *------------------------------------------------------------------------*/
687 void
hid_put_data_unsigned(uint8_t * buf,usb_size_t len,struct hid_location * loc,unsigned int value)688 hid_put_data_unsigned(uint8_t *buf, usb_size_t len,
689     struct hid_location *loc, unsigned int value)
690 {
691 	uint32_t hpos = loc->pos;
692 	uint32_t hsize = loc->size;
693 	uint64_t data;
694 	uint64_t mask;
695 	uint32_t rpos;
696 	uint8_t n;
697 
698 	DPRINTFN(11, "hid_put_data: loc %d/%d = %u\n", hpos, hsize, value);
699 
700 	/* Range check and limit */
701 	if (hsize == 0)
702 		return;
703 	if (hsize > 32)
704 		hsize = 32;
705 
706 	/* Put data in a safe way */
707 	rpos = (hpos / 8);
708 	n = (hsize + 7) / 8;
709 	data = ((uint64_t)value) << (hpos % 8);
710 	mask = ((1ULL << hsize) - 1ULL) << (hpos % 8);
711 	rpos += n;
712 	while (n--) {
713 		rpos--;
714 		if (rpos < len) {
715 			buf[rpos] &= ~(mask >> (8 * n));
716 			buf[rpos] |= (data >> (8 * n));
717 		}
718 	}
719 }
720 
721 /*------------------------------------------------------------------------*
722  *	hid_is_collection
723  *------------------------------------------------------------------------*/
724 int
hid_is_collection(const void * desc,usb_size_t size,int32_t usage)725 hid_is_collection(const void *desc, usb_size_t size, int32_t usage)
726 {
727 	struct hid_data *hd;
728 	struct hid_item hi;
729 	int err;
730 
731 	hd = hid_start_parse(desc, size, hid_input);
732 	if (hd == NULL)
733 		return (0);
734 
735 	while ((err = hid_get_item(hd, &hi))) {
736 		 if (hi.kind == hid_collection &&
737 		     hi.usage == usage)
738 			break;
739 	}
740 	hid_end_parse(hd);
741 	return (err);
742 }
743 
744 /*------------------------------------------------------------------------*
745  *	hid_get_descriptor_from_usb
746  *
747  * This function will search for a HID descriptor between two USB
748  * interface descriptors.
749  *
750  * Return values:
751  * NULL: No more HID descriptors.
752  * Else: Pointer to HID descriptor.
753  *------------------------------------------------------------------------*/
754 struct usb_hid_descriptor *
hid_get_descriptor_from_usb(struct usb_config_descriptor * cd,struct usb_interface_descriptor * id)755 hid_get_descriptor_from_usb(struct usb_config_descriptor *cd,
756     struct usb_interface_descriptor *id)
757 {
758 	struct usb_descriptor *desc = (void *)id;
759 
760 	if (desc == NULL) {
761 		return (NULL);
762 	}
763 	while ((desc = usb_desc_foreach(cd, desc))) {
764 		if ((desc->bDescriptorType == UDESC_HID) &&
765 		    (desc->bLength >= USB_HID_DESCRIPTOR_SIZE(0))) {
766 			return (void *)desc;
767 		}
768 		if (desc->bDescriptorType == UDESC_INTERFACE) {
769 			break;
770 		}
771 	}
772 	return (NULL);
773 }
774 
775 /*------------------------------------------------------------------------*
776  *	usbd_req_get_hid_desc
777  *
778  * This function will read out an USB report descriptor from the USB
779  * device.
780  *
781  * Return values:
782  * NULL: Failure.
783  * Else: Success. The pointer should eventually be passed to free().
784  *------------------------------------------------------------------------*/
785 usb_error_t
usbd_req_get_hid_desc(struct usb_device * udev,struct mtx * mtx,void ** descp,uint16_t * sizep,struct malloc_type * mem,uint8_t iface_index)786 usbd_req_get_hid_desc(struct usb_device *udev, struct mtx *mtx,
787     void **descp, uint16_t *sizep,
788     struct malloc_type *mem, uint8_t iface_index)
789 {
790 	struct usb_interface *iface = usbd_get_iface(udev, iface_index);
791 	struct usb_hid_descriptor *hid;
792 	usb_error_t err;
793 
794 	if ((iface == NULL) || (iface->idesc == NULL)) {
795 		return (USB_ERR_INVAL);
796 	}
797 	hid = hid_get_descriptor_from_usb
798 	    (usbd_get_config_descriptor(udev), iface->idesc);
799 
800 	if (hid == NULL) {
801 		return (USB_ERR_IOERROR);
802 	}
803 	*sizep = UGETW(hid->descrs[0].wDescriptorLength);
804 	if (*sizep == 0) {
805 		return (USB_ERR_IOERROR);
806 	}
807 	if (mtx)
808 		mtx_unlock(mtx);
809 
810 	*descp = zalloc(*sizep);
811 
812 	if (mtx)
813 		mtx_lock(mtx);
814 
815 	if (*descp == NULL) {
816 		return (USB_ERR_NOMEM);
817 	}
818 	err = usbd_req_get_report_descriptor
819 	    (udev, mtx, *descp, *sizep, iface_index);
820 
821 	if (err) {
822 		free(*descp);
823 		*descp = NULL;
824 		return (err);
825 	}
826 	return (USB_ERR_NORMAL_COMPLETION);
827 }
828 
829 /*------------------------------------------------------------------------*
830  * calculate HID item resolution. unit/mm for distances, unit/rad for angles
831  *------------------------------------------------------------------------*/
832 int32_t
hid_item_resolution(struct hid_item * hi)833 hid_item_resolution(struct hid_item *hi)
834 {
835 	/*
836 	 * hid unit scaling table according to HID Usage Table Review
837 	 * Request 39 Tbl 17 http://www.usb.org/developers/hidpage/HUTRR39b.pdf
838 	 */
839 	static const int64_t scale[0x10][2] = {
840 	    [0x00] = { 1, 1 },
841 	    [0x01] = { 1, 10 },
842 	    [0x02] = { 1, 100 },
843 	    [0x03] = { 1, 1000 },
844 	    [0x04] = { 1, 10000 },
845 	    [0x05] = { 1, 100000 },
846 	    [0x06] = { 1, 1000000 },
847 	    [0x07] = { 1, 10000000 },
848 	    [0x08] = { 100000000, 1 },
849 	    [0x09] = { 10000000, 1 },
850 	    [0x0A] = { 1000000, 1 },
851 	    [0x0B] = { 100000, 1 },
852 	    [0x0C] = { 10000, 1 },
853 	    [0x0D] = { 1000, 1 },
854 	    [0x0E] = { 100, 1 },
855 	    [0x0F] = { 10, 1 },
856 	};
857 	int64_t logical_size;
858 	int64_t physical_size;
859 	int64_t multiplier;
860 	int64_t divisor;
861 	int64_t resolution;
862 
863 	switch (hi->unit) {
864 	case HUM_CENTIMETER:
865 		multiplier = 1;
866 		divisor = 10;
867 		break;
868 	case HUM_INCH:
869 		multiplier = 10;
870 		divisor = 254;
871 		break;
872 	case HUM_RADIAN:
873 		multiplier = 1;
874 		divisor = 1;
875 		break;
876 	case HUM_DEGREE:
877 		multiplier = 573;
878 		divisor = 10;
879 		break;
880 	default:
881 		return (0);
882 	}
883 
884 	if ((hi->logical_maximum <= hi->logical_minimum) ||
885 	    (hi->physical_maximum <= hi->physical_minimum) ||
886 	    (hi->unit_exponent < 0) || (hi->unit_exponent >= nitems(scale)))
887 		return (0);
888 
889 	logical_size = (int64_t)hi->logical_maximum -
890 	    (int64_t)hi->logical_minimum;
891 	physical_size = (int64_t)hi->physical_maximum -
892 	    (int64_t)hi->physical_minimum;
893 	/* Round to ceiling */
894 	resolution = logical_size * multiplier * scale[hi->unit_exponent][0] /
895 	    (physical_size * divisor * scale[hi->unit_exponent][1]);
896 
897 	if (resolution > INT32_MAX)
898 		return (0);
899 
900 	return (resolution);
901 }
902 
903 /*------------------------------------------------------------------------*
904  *	hid_is_mouse
905  *
906  * This function will decide if a USB descriptor belongs to a USB mouse.
907  *
908  * Return values:
909  * Zero: Not a USB mouse.
910  * Else: Is a USB mouse.
911  *------------------------------------------------------------------------*/
912 int
hid_is_mouse(const void * d_ptr,uint16_t d_len)913 hid_is_mouse(const void *d_ptr, uint16_t d_len)
914 {
915 	struct hid_data *hd;
916 	struct hid_item hi;
917 	int mdepth;
918 	int found;
919 
920 	hd = hid_start_parse(d_ptr, d_len, 1 << hid_input);
921 	if (hd == NULL)
922 		return (0);
923 
924 	mdepth = 0;
925 	found = 0;
926 
927 	while (hid_get_item(hd, &hi)) {
928 		switch (hi.kind) {
929 		case hid_collection:
930 			if (mdepth != 0)
931 				mdepth++;
932 			else if (hi.collection == 1 &&
933 			     hi.usage ==
934 			      HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_MOUSE))
935 				mdepth++;
936 			break;
937 		case hid_endcollection:
938 			if (mdepth != 0)
939 				mdepth--;
940 			break;
941 		case hid_input:
942 			if (mdepth == 0)
943 				break;
944 			if (hi.usage ==
945 			     HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_X) &&
946 			    (hi.flags & (HIO_CONST|HIO_RELATIVE)) == HIO_RELATIVE)
947 				found++;
948 			if (hi.usage ==
949 			     HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_Y) &&
950 			    (hi.flags & (HIO_CONST|HIO_RELATIVE)) == HIO_RELATIVE)
951 				found++;
952 			break;
953 		default:
954 			break;
955 		}
956 	}
957 	hid_end_parse(hd);
958 	return (found);
959 }
960 
961 /*------------------------------------------------------------------------*
962  *	hid_is_keyboard
963  *
964  * This function will decide if a USB descriptor belongs to a USB keyboard.
965  *
966  * Return values:
967  * Zero: Not a USB keyboard.
968  * Else: Is a USB keyboard.
969  *------------------------------------------------------------------------*/
970 int
hid_is_keyboard(const void * d_ptr,uint16_t d_len)971 hid_is_keyboard(const void *d_ptr, uint16_t d_len)
972 {
973 	if (hid_is_collection(d_ptr, d_len,
974 	    HID_USAGE2(HUP_GENERIC_DESKTOP, HUG_KEYBOARD)))
975 		return (1);
976 	return (0);
977 }
978