xref: /src/sys/dev/hid/hid.c

/*	$NetBSD: hid.c,v 1.6 2023/10/17 02:46:57 nat Exp $	*/
/*	$FreeBSD: src/sys/dev/usb/hid.c,v 1.11 1999/11/17 22:33:39 n_hibma Exp $ */

/*
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart (at) augustsson.net) at
 * Carlstedt Research & Technology.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: hid.c,v 1.6 2023/10/17 02:46:57 nat Exp $");

#ifdef _KERNEL_OPT
#include "opt_usb.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kmem.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbhid.h>

#include <dev/hid/hid.h>

#ifdef UHIDEV_DEBUG
#define DPRINTF(x)	if (uhidevdebug) printf x
#define DPRINTFN(n,x)	if (uhidevdebug>(n)) printf x
extern int uhidevdebug;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

Static void hid_clear_local(struct hid_item *);

#define MAXUSAGE 256
struct hid_data {
	const u_char *start;
	const u_char *end;
	const u_char *p;
	struct hid_item cur;
	int32_t usages[MAXUSAGE];
	int nu;
	int minset;
	int multi;
	int multimax;
	enum hid_kind kind;
};

Static void
hid_clear_local(struct hid_item *c)
{

	DPRINTFN(5,("hid_clear_local\n"));
	c->usage = 0;
	c->usage_minimum = 0;
	c->usage_maximum = 0;
	c->designator_index = 0;
	c->designator_minimum = 0;
	c->designator_maximum = 0;
	c->string_index = 0;
	c->string_minimum = 0;
	c->string_maximum = 0;
	c->set_delimiter = 0;
}

struct hid_data *
hid_start_parse(const void *d, int len, enum hid_kind kind)
{
	struct hid_data *s;

	s = kmem_zalloc(sizeof(*s), KM_SLEEP);
	s->start = s->p = d;
	s->end = (const char *)d + len;
	s->kind = kind;
	return s;
}

void
hid_end_parse(struct hid_data *s)
{

	while (s->cur.next != NULL) {
		struct hid_item *hi = s->cur.next->next;
		kmem_free(s->cur.next, sizeof(*s->cur.next));
		s->cur.next = hi;
	}
	kmem_free(s, sizeof(*s));
}

int
hid_get_item(struct hid_data *s, struct hid_item *h)
{
	struct hid_item *c = &s->cur;
	unsigned int bTag, bType, bSize;
	uint32_t oldpos;
	const u_char *data;
	int32_t dval;
	uint32_t uval;
	const u_char *p;
	struct hid_item *hi;
	int i;
	enum hid_kind retkind;

 top:
	DPRINTFN(5,("hid_get_item: multi=%d multimax=%d\n",
		    s->multi, s->multimax));
	if (s->multimax != 0) {
		if (s->multi < s->multimax) {
			c->usage = s->usages[uimin(s->multi, s->nu-1)];
			s->multi++;
			*h = *c;
			c->loc.pos += c->loc.size;
			h->next = NULL;
			DPRINTFN(5,("return multi\n"));
			return 1;
		} else {
			c->loc.count = s->multimax;
			s->multimax = 0;
			s->nu = 0;
			hid_clear_local(c);
		}
	}
	for (;;) {
		p = s->p;

		if (s->end - p < 1)
			return 0;
		bSize = *p++;

		if (bSize == 0xfe) {
			/* long item */
			if (p + 3 > s->end)
				return 0;
			bSize = *p++;
			bSize |= *p++ << 8;
			bTag = *p++;
			bType = 0xff; /* XXX what should it be */
		} else {
			/* short item */
			bTag = bSize >> 4;
			bType = (bSize >> 2) & 3;
			bSize &= 3;
			if (bSize == 3)
				bSize = 4;
		}

		data = p;
		if (bSize > s->end - p)
			return 0;
		p += bSize;

		s->p = p;
		switch(bSize) {
		case 0:
			dval = 0;
			uval = dval;
			break;
		case 1:
			dval = *data++;
			uval = dval;
			dval = (int8_t)dval;
			break;
		case 2:
			dval = *data++;
			dval |= *data++ << 8;
			uval = dval;
			dval = (int16_t)dval;
			break;
		case 4:
			dval = *data++;
			dval |= *data++ << 8;
			dval |= *data++ << 16;
			dval |= *data++ << 24;
			uval = dval;
			dval = (int32_t)dval;
			break;
		default:
			aprint_normal("BAD LENGTH %d\n", bSize);
			continue;
		}

		DPRINTFN(5,("hid_get_item: bType=%d bTag=%d dval=%d uval=%u\n",
			 bType, bTag, dval, uval));
		switch (bType) {
		case 0:			/* Main */
			switch (bTag) {
			case 8:		/* Input */
				retkind = hid_input;
			ret:
				if (s->kind != retkind) {
					s->minset = 0;
					s->nu = 0;
					hid_clear_local(c);
					continue;
				}
				c->kind = retkind;
				c->flags = uval;
				if (c->flags & HIO_VARIABLE) {
					s->multimax = c->loc.count;
					s->multi = 0;
					c->loc.count = 1;
					if (s->minset) {
						for (i = c->usage_minimum;
						     i <= c->usage_maximum;
						     i++) {
							s->usages[s->nu] = i;
							if (s->nu < MAXUSAGE-1)
								s->nu++;
						}
						s->minset = 0;
					}
					goto top;
				} else {
					if (s->minset)
						c->usage = c->usage_minimum;
					*h = *c;
					h->next = NULL;
					c->loc.pos +=
					    c->loc.size * c->loc.count;
					s->minset = 0;
					s->nu = 0;
					hid_clear_local(c);
					return 1;
				}
			case 9:		/* Output */
				retkind = hid_output;
				goto ret;
			case 10:	/* Collection */
				c->kind = hid_collection;
				c->collection = uval;
				c->collevel++;
				*h = *c;
				hid_clear_local(c);
				s->nu = 0;
				return 1;
			case 11:	/* Feature */
				retkind = hid_feature;
				goto ret;
			case 12:	/* End collection */
				c->kind = hid_endcollection;
				c->collevel--;
				*h = *c;
				s->nu = 0;
				return 1;
			default:
				aprint_normal("Main bTag=%d\n", bTag);
				break;
			}
			break;
		case 1:		/* Global */
			switch (bTag) {
			case 0:
				c->_usage_page = uval << 16;
				break;
			case 1:
				c->logical_minimum = dval;
				break;
			case 2:
				c->logical_maximum = dval;
				break;
			case 3:
				c->physical_minimum = dval;
				break;
			case 4:
				c->physical_maximum = dval;
				break;
			case 5:
				c->unit_exponent = uval;
				break;
			case 6:
				c->unit = uval;
				break;
			case 7:
				c->loc.size = uval;
				break;
			case 8:
				c->report_ID = uval;
				c->loc.pos = 0;
				break;
			case 9:
				c->loc.count = uval;
				break;
			case 10: /* Push */
				hi = kmem_alloc(sizeof(*hi), KM_SLEEP);
				*hi = *c;
				c->next = hi;
				break;
			case 11: /* Pop */
				hi = c->next;
				if (hi == NULL)
					break;
				oldpos = c->loc.pos;
				*c = *hi;
				c->loc.pos = oldpos;
				kmem_free(hi, sizeof(*hi));
				break;
			default:
				aprint_normal("Global bTag=%d\n", bTag);
				break;
			}
			break;
		case 2:		/* Local */
			switch (bTag) {
			case 0:
				if (bSize < 4)
					uval = c->_usage_page | uval;
				c->usage = uval;
				if (s->nu < MAXUSAGE)
					s->usages[s->nu++] = uval;
				/* else XXX */
				break;
			case 1:
				s->minset = 1;
				if (bSize < 4)
					uval = c->_usage_page | uval;
				c->usage_minimum = uval;
				break;
			case 2:
				if (bSize < 4)
					uval = c->_usage_page | uval;
				c->usage_maximum = uval;
				break;
			case 3:
				c->designator_index = uval;
				break;
			case 4:
				c->designator_minimum = uval;
				break;
			case 5:
				c->designator_maximum = uval;
				break;
			case 7:
				c->string_index = uval;
				break;
			case 8:
				c->string_minimum = uval;
				break;
			case 9:
				c->string_maximum = uval;
				break;
			case 10:
				c->set_delimiter = uval;
				break;
			default:
				aprint_normal("Local bTag=%d\n", bTag);
				break;
			}
			break;
		default:
			aprint_normal("default bType=%d\n", bType);
			break;
		}
	}
}

int
hid_report_size(const void *buf, int len, enum hid_kind k, uint8_t id)
{
	struct hid_data *d;
	struct hid_item h;
	int lo, hi;

	h.report_ID = 0;
	lo = hi = -1;
	DPRINTFN(2,("hid_report_size: kind=%d id=%d\n", k, id));
	for (d = hid_start_parse(buf, len, k); hid_get_item(d, &h); ) {
		DPRINTFN(2,("hid_report_size: item kind=%d id=%d pos=%d "
			    "size=%d count=%d\n",
			    h.kind, h.report_ID, h.loc.pos, h.loc.size,
			    h.loc.count));
		if (h.report_ID == id && h.kind == k) {
			if (lo < 0) {
				lo = h.loc.pos;
#ifdef DIAGNOSTIC
				if (lo != 0) {
					aprint_normal("hid_report_size:"
					   " lo != 0\n");
				}
#endif
			}
			hi = h.loc.pos + h.loc.size * h.loc.count;
			DPRINTFN(2,("hid_report_size: lo=%d hi=%d\n", lo, hi));
		}
	}
	hid_end_parse(d);
	return (hi - lo + 7) / 8;
}

int
hid_locate(const void *desc, int size, uint32_t u, uint8_t id, enum hid_kind k,
	   struct hid_location *loc, uint32_t *flags)
{
	struct hid_data *d;
	struct hid_item h;

	h.report_ID = 0;
	DPRINTFN(5,("hid_locate: enter usage=0x%x kind=%d id=%d\n", u, k, id));
	for (d = hid_start_parse(desc, size, k); hid_get_item(d, &h); ) {
		DPRINTFN(5,("hid_locate: usage=0x%x kind=%d id=%d flags=0x%x\n",
			    h.usage, h.kind, h.report_ID, h.flags));
		if (h.kind == k && !(h.flags & HIO_CONST) &&
		    h.usage == u && h.report_ID == id) {
			if (loc != NULL)
				*loc = h.loc;
			if (flags != NULL)
				*flags = h.flags;
			hid_end_parse(d);
			return 1;
		}
	}
	hid_end_parse(d);
	if (loc != NULL)
		loc->size = 0;
	return 0;
}

long
hid_get_data(const u_char *buf, const struct hid_location *loc)
{
	u_int hsize = loc->size;
	u_long data;

	if (hsize == 0)
		return 0;

	data = hid_get_udata(buf, loc);
	if (data < (1UL << (hsize - 1)) || hsize == sizeof(data) * NBBY)
		return data;
	return data - (1UL << hsize);
}

u_long
hid_get_udata(const u_char *buf, const struct hid_location *loc)
{
	u_int hpos = loc->pos;
	u_int hsize = loc->size;
	u_int i, num, off;
	u_long data;

	if (hsize == 0)
		return 0;

	data = 0;
	off = hpos / 8;
	num = (hpos + hsize + 7) / 8 - off;

	for (i = 0; i < num; i++)
		data |= (unsigned long)buf[off + i] << (i * 8);

	data >>= hpos % 8;
	if (hsize < sizeof(data) * NBBY)
		data &= (1UL << hsize) - 1;

	DPRINTFN(10,("hid_get_udata: loc %d/%d = %lu\n", hpos, hsize, data));
	return data;
}

/*
 * hid_is_collection(desc, size, id, usage)
 *
 * This function is broken in the following way.
 *
 * It is used to discover if the given 'id' is part of 'usage' collection
 * in the descriptor in order to match report id against device type.
 *
 * The semantics of hid_start_parse() means though, that only a single
 * kind of report is considered. The current HID code that uses this for
 * matching is actually only looking for input reports, so this works
 * for now.
 *
 * This function could try all report kinds (input, output and feature)
 * consecutively if necessary, but it may be better to integrate the
 * libusbhid code which can consider multiple report kinds simultaneously
 *
 * Needs some thought.
 */
int
hid_is_collection(const void *desc, int size, uint8_t id, uint32_t usage)
{
	struct hid_data *hd;
	struct hid_item hi;
	uint32_t coll_usage = ~0;

	hd = hid_start_parse(desc, size, hid_input);
	if (hd == NULL)
		return 0;

	DPRINTFN(2,("hid_is_collection: id=%d usage=0x%x\n", id, usage));
	while (hid_get_item(hd, &hi)) {
		DPRINTFN(2,("hid_is_collection: kind=%d id=%d usage=0x%x"
			    "(0x%x)\n",
			    hi.kind, hi.report_ID, hi.usage, coll_usage));

		if (hi.kind == hid_collection &&
		    (hi.collection == HCOLL_APPLICATION ||
		    hi.collection == HCOLL_PHYSICAL ||
		    hi.collection == HCOLL_LOGICAL))
			coll_usage = hi.usage;

		if (hi.kind == hid_endcollection)
			coll_usage = ~0;

		if (hi.kind == hid_collection &&
		    coll_usage == usage &&
		    hi.report_ID == id) {
			DPRINTFN(2,("hid_is_collection: found\n"));
			hid_end_parse(hd);
			return 1;
		}
	}
	DPRINTFN(2,("hid_is_collection: not found\n"));
	hid_end_parse(hd);
	return 0;
}