xref: /freebsd/lib/libusbhid/parse.c (revision b601c69bdbe8755d26570261d7fd4c02ee4eff74)
1 /*	$NetBSD: parse.c,v 1.9 2000/03/17 18:09:17 augustss Exp $	*/
2 
3 /*
4  * Copyright (c) 1999 Lennart Augustsson <augustss@netbsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  *
30  */
31 
32 #include <assert.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <sys/time.h>
36 
37 #include <dev/usb/usb.h>
38 #include <dev/usb/usbhid.h>
39 
40 #include "libusb.h"
41 #include "usbvar.h"
42 
43 #define MAXUSAGE 100
44 struct hid_data {
45 	u_char *start;
46 	u_char *end;
47 	u_char *p;
48 	hid_item_t cur;
49 	unsigned int usages[MAXUSAGE];
50 	int nusage;
51 	int minset;
52 	int multi;
53 	int multimax;
54 	int kindset;
55 };
56 
57 static int min(int x, int y) { return x < y ? x : y; }
58 
59 static void
60 hid_clear_local(hid_item_t *c)
61 {
62 	c->usage = 0;
63 	c->usage_minimum = 0;
64 	c->usage_maximum = 0;
65 	c->designator_index = 0;
66 	c->designator_minimum = 0;
67 	c->designator_maximum = 0;
68 	c->string_index = 0;
69 	c->string_minimum = 0;
70 	c->string_maximum = 0;
71 	c->set_delimiter = 0;
72 }
73 
74 hid_data_t
75 hid_start_parse(report_desc_t d, int kindset)
76 {
77 	struct hid_data *s;
78 
79 	s = malloc(sizeof *s);
80 	memset(s, 0, sizeof *s);
81 	s->start = s->p = d->data;
82 	s->end = d->data + d->size;
83 	s->kindset = kindset;
84 	return (s);
85 }
86 
87 void
88 hid_end_parse(hid_data_t s)
89 {
90 	while (s->cur.next) {
91 		hid_item_t *hi = s->cur.next->next;
92 		free(s->cur.next);
93 		s->cur.next = hi;
94 	}
95 	free(s);
96 }
97 
98 int
99 hid_get_item(hid_data_t s, hid_item_t *h)
100 {
101 	hid_item_t *c;
102 	unsigned int bTag = 0, bType = 0, bSize, oldpos;
103 	unsigned char *data;
104 	int dval;
105 	unsigned char *p;
106 	hid_item_t *hi;
107 	int i;
108 
109 	c = &s->cur;
110 
111  top:
112 	if (s->multimax) {
113 		if (s->multi < s->multimax) {
114 			c->usage = s->usages[min(s->multi, s->nusage-1)];
115 			s->multi++;
116 			*h = *c;
117 			c->pos += c->report_size;
118 			h->next = 0;
119 			return (1);
120 		} else {
121 			c->report_count = s->multimax;
122 			s->multimax = 0;
123 			s->nusage = 0;
124 			hid_clear_local(c);
125 		}
126 	}
127 	for (;;) {
128 		p = s->p;
129 		if (p >= s->end)
130 			return (0);
131 
132 		bSize = *p++;
133 		if (bSize == 0xfe) {
134 			/* long item */
135 			bSize = *p++;
136 			bSize |= *p++ << 8;
137 			bTag = *p++;
138 			data = p;
139 			p += bSize;
140 		} else {
141 			/* short item */
142 			bTag = bSize >> 4;
143 			bType = (bSize >> 2) & 3;
144 			bSize &= 3;
145 			if (bSize == 3) bSize = 4;
146 			data = p;
147 			p += bSize;
148 		}
149 		s->p = p;
150 		/*
151 		 * The spec is unclear if the data is signed or unsigned.
152 		 */
153 		switch(bSize) {
154 		case 0:
155 			dval = 0;
156 			break;
157 		case 1:
158 			dval = (int8_t)*data++;
159 			break;
160 		case 2:
161 			dval = *data++;
162 			dval |= *data++ << 8;
163 			dval = (int16_t)dval;
164 			break;
165 		case 4:
166 			dval = *data++;
167 			dval |= *data++ << 8;
168 			dval |= *data++ << 16;
169 			dval |= *data++ << 24;
170 			break;
171 		default:
172 			return (-1);
173 		}
174 
175 		switch (bType) {
176 		case 0:			/* Main */
177 			switch (bTag) {
178 			case 8:		/* Input */
179 				if (!(s->kindset & (1 << hid_input)))
180 					continue;
181 				c->kind = hid_input;
182 				c->flags = dval;
183 			ret:
184 				if (c->flags & HIO_VARIABLE) {
185 					s->multimax = c->report_count;
186 					s->multi = 0;
187 					c->report_count = 1;
188 					if (s->minset) {
189 						for (i = c->usage_minimum;
190 						     i <= c->usage_maximum;
191 						     i++) {
192 							s->usages[s->nusage] = i;
193 							if (s->nusage < MAXUSAGE-1)
194 								s->nusage++;
195 						}
196 						s->minset = 0;
197 					}
198 					goto top;
199 				} else {
200 					if (s->minset)
201 						c->usage = c->usage_minimum;
202 					*h = *c;
203 					h->next = 0;
204 					c->pos += c->report_size * c->report_count;
205 					hid_clear_local(c);
206 					s->minset = 0;
207 					return (1);
208 				}
209 			case 9:		/* Output */
210 				if (!(s->kindset & (1 << hid_output)))
211 					continue;
212 				c->kind = hid_output;
213 				c->flags = dval;
214 				goto ret;
215 			case 10:	/* Collection */
216 				c->kind = hid_collection;
217 				c->collection = dval;
218 				c->collevel++;
219 				*h = *c;
220 				hid_clear_local(c);
221 				c->report_ID = NO_REPORT_ID;
222 				s->nusage = 0;
223 				return (1);
224 			case 11:	/* Feature */
225 				if (!(s->kindset & (1 << hid_feature)))
226 					continue;
227 				c->kind = hid_feature;
228 				c->flags = dval;
229 				goto ret;
230 			case 12:	/* End collection */
231 				c->kind = hid_endcollection;
232 				c->collevel--;
233 				*h = *c;
234 				/*hid_clear_local(c);*/
235 				s->nusage = 0;
236 				return (1);
237 			default:
238 				return (-2);
239 			}
240 
241 		case 1:		/* Global */
242 			switch (bTag) {
243 			case 0:
244 				c->_usage_page = dval << 16;
245 				break;
246 			case 1:
247 				c->logical_minimum = dval;
248 				break;
249 			case 2:
250 				c->logical_maximum = dval;
251 				break;
252 			case 3:
253 				c->physical_maximum = dval;
254 				break;
255 			case 4:
256 				c->physical_maximum = dval;
257 				break;
258 			case 5:
259 				c->unit_exponent = dval;
260 				break;
261 			case 6:
262 				c->unit = dval;
263 				break;
264 			case 7:
265 				c->report_size = dval;
266 				break;
267 			case 8:
268 				c->report_ID = dval;
269 				break;
270 			case 9:
271 				c->report_count = dval;
272 				break;
273 			case 10: /* Push */
274 				hi = malloc(sizeof *hi);
275 				*hi = s->cur;
276 				c->next = hi;
277 				break;
278 			case 11: /* Pop */
279 				hi = c->next;
280 				oldpos = c->pos;
281 				s->cur = *hi;
282 				c->pos = oldpos;
283 				free(hi);
284 				break;
285 			default:
286 				return (-3);
287 			}
288 			break;
289 		case 2:		/* Local */
290 			switch (bTag) {
291 			case 0:
292 				if (bSize == 1)
293 					dval = c->_usage_page | (dval&0xff);
294 				else if (bSize == 2)
295 					dval = c->_usage_page | (dval&0xffff);
296 				c->usage = dval;
297 				if (s->nusage < MAXUSAGE)
298 					s->usages[s->nusage++] = dval;
299 				/* else XXX */
300 				break;
301 			case 1:
302 				s->minset = 1;
303 				if (bSize == 1)
304 					dval = c->_usage_page | (dval&0xff);
305 				else if (bSize == 2)
306 					dval = c->_usage_page | (dval&0xffff);
307 				c->usage_minimum = dval;
308 				break;
309 			case 2:
310 				if (bSize == 1)
311 					dval = c->_usage_page | (dval&0xff);
312 				else if (bSize == 2)
313 					dval = c->_usage_page | (dval&0xffff);
314 				c->usage_maximum = dval;
315 				break;
316 			case 3:
317 				c->designator_index = dval;
318 				break;
319 			case 4:
320 				c->designator_minimum = dval;
321 				break;
322 			case 5:
323 				c->designator_maximum = dval;
324 				break;
325 			case 7:
326 				c->string_index = dval;
327 				break;
328 			case 8:
329 				c->string_minimum = dval;
330 				break;
331 			case 9:
332 				c->string_maximum = dval;
333 				break;
334 			case 10:
335 				c->set_delimiter = dval;
336 				break;
337 			default:
338 				return (-4);
339 			}
340 			break;
341 		default:
342 			return (-5);
343 		}
344 	}
345 }
346 
347 int
348 hid_report_size(report_desc_t r, enum hid_kind k, int *idp)
349 {
350 	struct hid_data *d;
351 	hid_item_t h;
352 	int size, id;
353 
354 	id = 0;
355 	if (idp)
356 		*idp = 0;
357 	memset(&h, 0, sizeof h);
358 	for (d = hid_start_parse(r, 1<<k); hid_get_item(d, &h); ) {
359 		if (h.report_ID != NO_REPORT_ID) {
360 			if (idp)
361 				*idp = h.report_ID;
362 			id = 8;
363 		}
364 	}
365 	hid_end_parse(d);
366 	size = h.pos + id;
367 	return ((size + 7) / 8);
368 }
369 
370 int
371 hid_locate(desc, u, k, h)
372 	report_desc_t desc;
373 	unsigned int u;
374 	enum hid_kind k;
375 	hid_item_t *h;
376 {
377 	hid_data_t d;
378 
379 	for (d = hid_start_parse(desc, 1<<k); hid_get_item(d, h); ) {
380 		if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
381 			hid_end_parse(d);
382 			return (1);
383 		}
384 	}
385 	hid_end_parse(d);
386 	h->report_size = 0;
387 	return (0);
388 }
389