xref: /netbsd-src/lib/libusbhid/parse.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: parse.c,v 1.5 2004/01/05 17:55:48 augustss Exp $	*/
2 
3 /*
4  * Copyright (c) 1999, 2001 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 
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: parse.c,v 1.5 2004/01/05 17:55:48 augustss Exp $");
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 "usbhid.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 logminsize;
53 	int multi;
54 	int multimax;
55 	int kindset;
56 	int reportid;
57 
58 	/*
59 	 * The start of collection item has no report ID set, so save
60 	 * it until we know the ID.
61 	 */
62 	hid_item_t savedcoll;
63 	u_char hassavedcoll;
64 	/*
65 	 * Absolute data position (bits) for input/output/feature.
66 	 *  Assumes that hid_input, hid_output and hid_feature have
67 	 *  values 0, 1 and 2.
68 	 */
69 	unsigned int kindpos[3];
70 };
71 
72 static int min(int x, int y) { return x < y ? x : y; }
73 
74 static int hid_get_item_raw(hid_data_t s, hid_item_t *h);
75 
76 static void
77 hid_clear_local(hid_item_t *c)
78 {
79 
80 	_DIAGASSERT(c != NULL);
81 
82 	c->usage = 0;
83 	c->usage_minimum = 0;
84 	c->usage_maximum = 0;
85 	c->designator_index = 0;
86 	c->designator_minimum = 0;
87 	c->designator_maximum = 0;
88 	c->string_index = 0;
89 	c->string_minimum = 0;
90 	c->string_maximum = 0;
91 	c->set_delimiter = 0;
92 }
93 
94 hid_data_t
95 hid_start_parse(report_desc_t d, int kindset, int id)
96 {
97 	struct hid_data *s;
98 
99 	_DIAGASSERT(d != NULL);
100 
101 	s = malloc(sizeof *s);
102 	memset(s, 0, sizeof *s);
103 	s->start = s->p = d->data;
104 	s->end = d->data + d->size;
105 	s->kindset = kindset;
106 	s->reportid = id;
107 	s->hassavedcoll = 0;
108 	return (s);
109 }
110 
111 void
112 hid_end_parse(hid_data_t s)
113 {
114 
115 	_DIAGASSERT(s != NULL);
116 
117 	while (s->cur.next) {
118 		hid_item_t *hi = s->cur.next->next;
119 		free(s->cur.next);
120 		s->cur.next = hi;
121 	}
122 	free(s);
123 }
124 
125 int
126 hid_get_item(hid_data_t s, hid_item_t *h)
127 {
128 	int r;
129 
130 	for (;;) {
131 		r = hid_get_item_raw(s, h);
132 		if (r <= 0)
133 			break;
134 		if (h->report_ID == s->reportid || s->reportid == -1)
135 			break;
136 	}
137 	return (r);
138 }
139 
140 #define REPORT_SAVED_COLL \
141 	do { \
142 		if (s->hassavedcoll) { \
143 			*h = s->savedcoll; \
144 			h->report_ID = c->report_ID; \
145 			s->hassavedcoll = 0; \
146 			return (1); \
147 		} \
148 	} while(/*LINTED*/ 0)
149 
150 static int
151 hid_get_item_raw(hid_data_t s, hid_item_t *h)
152 {
153 	hid_item_t *c;
154 	unsigned int bTag = 0, bType = 0, bSize;
155 	unsigned char *data;
156 	int dval;
157 	unsigned char *p;
158 	hid_item_t *hi;
159 	hid_item_t nc;
160 	int i;
161 	hid_kind_t retkind;
162 
163 	_DIAGASSERT(s != NULL);
164 	_DIAGASSERT(h != NULL);
165 
166 	c = &s->cur;
167 
168  top:
169 	if (s->multimax) {
170 		REPORT_SAVED_COLL;
171 		if (c->logical_minimum >= c->logical_maximum) {
172 			if (s->logminsize == 1)
173 				c->logical_minimum =(int8_t)c->logical_minimum;
174 			else if (s->logminsize == 2)
175 				c->logical_minimum =(int16_t)c->logical_minimum;
176 		}
177 		if (s->multi < s->multimax) {
178 			c->usage = s->usages[min(s->multi, s->nusage-1)];
179 			s->multi++;
180 			*h = *c;
181 			/*
182 			 * 'multimax' is only non-zero if the current
183                          *  item kind is input/output/feature
184 			 */
185 			h->pos = s->kindpos[c->kind];
186 			s->kindpos[c->kind] += c->report_size;
187 			h->next = 0;
188 			return (1);
189 		} else {
190 			c->report_count = s->multimax;
191 			s->multimax = 0;
192 			s->nusage = 0;
193 			hid_clear_local(c);
194 		}
195 	}
196 	for (;;) {
197 		p = s->p;
198 		if (p >= s->end)
199 			return (0);
200 
201 		bSize = *p++;
202 		if (bSize == 0xfe) {
203 			/* long item */
204 			bSize = *p++;
205 			bSize |= *p++ << 8;
206 			bTag = *p++;
207 			data = p;
208 			p += bSize;
209 		} else {
210 			/* short item */
211 			bTag = bSize >> 4;
212 			bType = (bSize >> 2) & 3;
213 			bSize &= 3;
214 			if (bSize == 3) bSize = 4;
215 			data = p;
216 			p += bSize;
217 		}
218 		s->p = p;
219 		/*
220 		 * The spec is unclear if the data is signed or unsigned.
221 		 */
222 		switch(bSize) {
223 		case 0:
224 			dval = 0;
225 			break;
226 		case 1:
227 			dval = /*(int8_t)*/*data++;
228 			break;
229 		case 2:
230 			dval = *data++;
231 			dval |= *data++ << 8;
232 			dval = /*(int16_t)*/dval;
233 			break;
234 		case 4:
235 			dval = *data++;
236 			dval |= *data++ << 8;
237 			dval |= *data++ << 16;
238 			dval |= *data++ << 24;
239 			break;
240 		default:
241 			return (-1);
242 		}
243 
244 		switch (bType) {
245 		case 0:			/* Main */
246 			switch (bTag) {
247 			case 8:		/* Input */
248 				retkind = hid_input;
249 			ret:
250 				if (!(s->kindset & (1 << retkind))) {
251 					/* Drop the items of this kind */
252 					s->nusage = 0;
253 					continue;
254 				}
255 				c->kind = retkind;
256 				c->flags = dval;
257 				if (c->flags & HIO_VARIABLE) {
258 					s->multimax = c->report_count;
259 					s->multi = 0;
260 					c->report_count = 1;
261 					if (s->minset) {
262 						for (i = c->usage_minimum;
263 						     i <= c->usage_maximum;
264 						     i++) {
265 							s->usages[s->nusage] = i;
266 							if (s->nusage < MAXUSAGE-1)
267 								s->nusage++;
268 						}
269 						c->usage_minimum = 0;
270 						c->usage_maximum = 0;
271 						s->minset = 0;
272 					}
273 					goto top;
274 				} else {
275 					if (s->minset)
276 						c->usage = c->usage_minimum;
277 					*h = *c;
278 					h->next = 0;
279 					h->pos = s->kindpos[c->kind];
280 					s->kindpos[c->kind] +=
281 					    c->report_size * c->report_count;
282 					hid_clear_local(c);
283 					s->minset = 0;
284 					return (1);
285 				}
286 			case 9:		/* Output */
287 				retkind = hid_output;
288 				goto ret;
289 			case 10:	/* Collection */
290 				c->kind = hid_collection;
291 				c->collection = dval;
292 				c->collevel++;
293 				nc = *c;
294 				hid_clear_local(c);
295 				/*c->report_ID = NO_REPORT_ID;*/
296 				s->nusage = 0;
297 				if (s->hassavedcoll) {
298 					*h = s->savedcoll;
299 					h->report_ID = nc.report_ID;
300 					s->savedcoll = nc;
301 					return (1);
302 				} else {
303 					s->hassavedcoll = 1;
304 					s->savedcoll = nc;
305 				}
306 				break;
307 			case 11:	/* Feature */
308 				retkind = hid_feature;
309 				goto ret;
310 			case 12:	/* End collection */
311 				REPORT_SAVED_COLL;
312 				c->kind = hid_endcollection;
313 				c->collevel--;
314 				*h = *c;
315 				/*hid_clear_local(c);*/
316 				s->nusage = 0;
317 				return (1);
318 			default:
319 				return (-2);
320 			}
321 			break;
322 
323 		case 1:		/* Global */
324 			switch (bTag) {
325 			case 0:
326 				c->_usage_page = dval << 16;
327 				break;
328 			case 1:
329 				c->logical_minimum = dval;
330 				s->logminsize = bSize;
331 				break;
332 			case 2:
333 				c->logical_maximum = dval;
334 				break;
335 			case 3:
336 				c->physical_maximum = dval;
337 				break;
338 			case 4:
339 				c->physical_maximum = dval;
340 				break;
341 			case 5:
342 				c->unit_exponent = dval;
343 				break;
344 			case 6:
345 				c->unit = dval;
346 				break;
347 			case 7:
348 				c->report_size = dval;
349 				break;
350 			case 8:
351 				c->report_ID = dval;
352 				s->kindpos[hid_input] =
353 				    s->kindpos[hid_output] =
354 				    s->kindpos[hid_feature] = 0;
355 				break;
356 			case 9:
357 				c->report_count = dval;
358 				break;
359 			case 10: /* Push */
360 				hi = malloc(sizeof *hi);
361 				*hi = s->cur;
362 				c->next = hi;
363 				break;
364 			case 11: /* Pop */
365 				hi = c->next;
366 				s->cur = *hi;
367 				free(hi);
368 				break;
369 			default:
370 				return (-3);
371 			}
372 			break;
373 		case 2:		/* Local */
374 			switch (bTag) {
375 			case 0:
376 				c->usage = c->_usage_page | dval;
377 				if (s->nusage < MAXUSAGE)
378 					s->usages[s->nusage++] = c->usage;
379 				/* else XXX */
380 				break;
381 			case 1:
382 				s->minset = 1;
383 				c->usage_minimum = c->_usage_page | dval;
384 				break;
385 			case 2:
386 				c->usage_maximum = c->_usage_page | dval;
387 				break;
388 			case 3:
389 				c->designator_index = dval;
390 				break;
391 			case 4:
392 				c->designator_minimum = dval;
393 				break;
394 			case 5:
395 				c->designator_maximum = dval;
396 				break;
397 			case 7:
398 				c->string_index = dval;
399 				break;
400 			case 8:
401 				c->string_minimum = dval;
402 				break;
403 			case 9:
404 				c->string_maximum = dval;
405 				break;
406 			case 10:
407 				c->set_delimiter = dval;
408 				break;
409 			default:
410 				return (-4);
411 			}
412 			break;
413 		default:
414 			return (-5);
415 		}
416 	}
417 }
418 
419 int
420 hid_report_size(report_desc_t r, enum hid_kind k, int id)
421 {
422 	struct hid_data *d;
423 	hid_item_t h;
424 	int size;
425 
426 	_DIAGASSERT(r != NULL);
427 
428 	memset(&h, 0, sizeof h);
429 	size = 0;
430 	for (d = hid_start_parse(r, 1<<k, id); hid_get_item(d, &h); ) {
431 		if (h.report_ID == id && h.kind == k) {
432 			size = d->kindpos[k];
433 		}
434 	}
435 	hid_end_parse(d);
436 	return ((size + 7) / 8);
437 }
438 
439 int
440 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
441 	   hid_item_t *h, int id)
442 {
443 	hid_data_t d;
444 
445 	_DIAGASSERT(desc != NULL);
446 	_DIAGASSERT(h != NULL);
447 
448 	for (d = hid_start_parse(desc, 1<<k, id); hid_get_item(d, h); ) {
449 		if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
450 			hid_end_parse(d);
451 			return (1);
452 		}
453 	}
454 	hid_end_parse(d);
455 	h->report_size = 0;
456 	return (0);
457 }
458