xref: /netbsd-src/lib/libusbhid/parse.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: parse.c,v 1.7 2010/08/13 19:56:34 jakllsch 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 1.7 2010/08/13 19:56:34 jakllsch 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 phyminsize;
54 	int multi;
55 	int multimax;
56 	int kindset;
57 	int reportid;
58 
59 	/*
60 	 * The start of collection item has no report ID set, so save
61 	 * it until we know the ID.
62 	 */
63 	hid_item_t savedcoll;
64 	u_char hassavedcoll;
65 	/*
66 	 * Absolute data position (bits) for input/output/feature.
67 	 *  Assumes that hid_input, hid_output and hid_feature have
68 	 *  values 0, 1 and 2.
69 	 */
70 	unsigned int kindpos[3];
71 };
72 
73 static int min(int x, int y) { return x < y ? x : y; }
74 
75 static int hid_get_item_raw(hid_data_t s, hid_item_t *h);
76 
77 static void
78 hid_clear_local(hid_item_t *c)
79 {
80 
81 	_DIAGASSERT(c != NULL);
82 
83 	c->usage = 0;
84 	c->usage_minimum = 0;
85 	c->usage_maximum = 0;
86 	c->designator_index = 0;
87 	c->designator_minimum = 0;
88 	c->designator_maximum = 0;
89 	c->string_index = 0;
90 	c->string_minimum = 0;
91 	c->string_maximum = 0;
92 	c->set_delimiter = 0;
93 }
94 
95 hid_data_t
96 hid_start_parse(report_desc_t d, int kindset, int id)
97 {
98 	struct hid_data *s;
99 
100 	_DIAGASSERT(d != NULL);
101 
102 	s = malloc(sizeof *s);
103 	memset(s, 0, sizeof *s);
104 	s->start = s->p = d->data;
105 	s->end = d->data + d->size;
106 	s->kindset = kindset;
107 	s->reportid = id;
108 	s->hassavedcoll = 0;
109 	return (s);
110 }
111 
112 void
113 hid_end_parse(hid_data_t s)
114 {
115 
116 	_DIAGASSERT(s != NULL);
117 
118 	while (s->cur.next) {
119 		hid_item_t *hi = s->cur.next->next;
120 		free(s->cur.next);
121 		s->cur.next = hi;
122 	}
123 	free(s);
124 }
125 
126 int
127 hid_get_item(hid_data_t s, hid_item_t *h)
128 {
129 	int r;
130 
131 	for (;;) {
132 		r = hid_get_item_raw(s, h);
133 		if (r <= 0)
134 			break;
135 		if (h->report_ID == s->reportid || s->reportid == -1)
136 			break;
137 	}
138 	return (r);
139 }
140 
141 #define REPORT_SAVED_COLL \
142 	do { \
143 		if (s->hassavedcoll) { \
144 			*h = s->savedcoll; \
145 			h->report_ID = c->report_ID; \
146 			s->hassavedcoll = 0; \
147 			return (1); \
148 		} \
149 	} while(/*LINTED*/ 0)
150 
151 static int
152 hid_get_item_raw(hid_data_t s, hid_item_t *h)
153 {
154 	hid_item_t *c;
155 	unsigned int bTag = 0, bType = 0, bSize;
156 	unsigned char *data;
157 	int dval;
158 	unsigned char *p;
159 	hid_item_t *hi;
160 	hid_item_t nc;
161 	int i;
162 	hid_kind_t retkind;
163 
164 	_DIAGASSERT(s != NULL);
165 	_DIAGASSERT(h != NULL);
166 
167 	c = &s->cur;
168 
169  top:
170 	if (s->multimax) {
171 		REPORT_SAVED_COLL;
172 		if (c->logical_minimum >= c->logical_maximum) {
173 			if (s->logminsize == 1)
174 				c->logical_minimum =(int8_t)c->logical_minimum;
175 			else if (s->logminsize == 2)
176 				c->logical_minimum =(int16_t)c->logical_minimum;
177 		}
178 		if (c->physical_minimum >= c->physical_maximum) {
179 			if (s->phyminsize == 1)
180 				c->physical_minimum =
181 					(int8_t)c->physical_minimum;
182 			else if (s->phyminsize == 2)
183 				c->physical_minimum =
184 					(int16_t)c->physical_minimum;
185 		}
186 		if (s->multi < s->multimax) {
187 			c->usage = s->usages[min(s->multi, s->nusage-1)];
188 			s->multi++;
189 			*h = *c;
190 			/*
191 			 * 'multimax' is only non-zero if the current
192                          *  item kind is input/output/feature
193 			 */
194 			h->pos = s->kindpos[c->kind];
195 			s->kindpos[c->kind] += c->report_size;
196 			h->next = 0;
197 			return (1);
198 		} else {
199 			c->report_count = s->multimax;
200 			s->multimax = 0;
201 			s->nusage = 0;
202 			hid_clear_local(c);
203 		}
204 	}
205 	for (;;) {
206 		p = s->p;
207 		if (p >= s->end)
208 			return (0);
209 
210 		bSize = *p++;
211 		if (bSize == 0xfe) {
212 			/* long item */
213 			bSize = *p++;
214 			bSize |= *p++ << 8;
215 			bTag = *p++;
216 			data = p;
217 			p += bSize;
218 		} else {
219 			/* short item */
220 			bTag = bSize >> 4;
221 			bType = (bSize >> 2) & 3;
222 			bSize &= 3;
223 			if (bSize == 3) bSize = 4;
224 			data = p;
225 			p += bSize;
226 		}
227 		s->p = p;
228 		/*
229 		 * The spec is unclear if the data is signed or unsigned.
230 		 */
231 		switch(bSize) {
232 		case 0:
233 			dval = 0;
234 			break;
235 		case 1:
236 			dval = /*(int8_t)*/*data++;
237 			break;
238 		case 2:
239 			dval = *data++;
240 			dval |= *data++ << 8;
241 			dval = /*(int16_t)*/dval;
242 			break;
243 		case 4:
244 			dval = *data++;
245 			dval |= *data++ << 8;
246 			dval |= *data++ << 16;
247 			dval |= *data++ << 24;
248 			break;
249 		default:
250 			return (-1);
251 		}
252 
253 		switch (bType) {
254 		case 0:			/* Main */
255 			switch (bTag) {
256 			case 8:		/* Input */
257 				retkind = hid_input;
258 			ret:
259 				if (!(s->kindset & (1 << retkind))) {
260 					/* Drop the items of this kind */
261 					s->nusage = 0;
262 					continue;
263 				}
264 				c->kind = retkind;
265 				c->flags = dval;
266 				if (c->flags & HIO_VARIABLE) {
267 					s->multimax = c->report_count;
268 					s->multi = 0;
269 					c->report_count = 1;
270 					if (s->minset) {
271 						for (i = c->usage_minimum;
272 						     i <= c->usage_maximum;
273 						     i++) {
274 							s->usages[s->nusage] = i;
275 							if (s->nusage < MAXUSAGE-1)
276 								s->nusage++;
277 						}
278 						c->usage_minimum = 0;
279 						c->usage_maximum = 0;
280 						s->minset = 0;
281 					}
282 					goto top;
283 				} else {
284 					if (s->minset)
285 						c->usage = c->usage_minimum;
286 					*h = *c;
287 					h->next = 0;
288 					h->pos = s->kindpos[c->kind];
289 					s->kindpos[c->kind] +=
290 					    c->report_size * c->report_count;
291 					hid_clear_local(c);
292 					s->minset = 0;
293 					return (1);
294 				}
295 			case 9:		/* Output */
296 				retkind = hid_output;
297 				goto ret;
298 			case 10:	/* Collection */
299 				c->kind = hid_collection;
300 				c->collection = dval;
301 				c->collevel++;
302 				nc = *c;
303 				hid_clear_local(c);
304 				/*c->report_ID = NO_REPORT_ID;*/
305 				s->nusage = 0;
306 				if (s->hassavedcoll) {
307 					*h = s->savedcoll;
308 					h->report_ID = nc.report_ID;
309 					s->savedcoll = nc;
310 					return (1);
311 				} else {
312 					s->hassavedcoll = 1;
313 					s->savedcoll = nc;
314 				}
315 				break;
316 			case 11:	/* Feature */
317 				retkind = hid_feature;
318 				goto ret;
319 			case 12:	/* End collection */
320 				REPORT_SAVED_COLL;
321 				c->kind = hid_endcollection;
322 				c->collevel--;
323 				*h = *c;
324 				/*hid_clear_local(c);*/
325 				s->nusage = 0;
326 				return (1);
327 			default:
328 				return (-2);
329 			}
330 			break;
331 
332 		case 1:		/* Global */
333 			switch (bTag) {
334 			case 0:
335 				c->_usage_page = dval << 16;
336 				break;
337 			case 1:
338 				c->logical_minimum = dval;
339 				s->logminsize = bSize;
340 				break;
341 			case 2:
342 				c->logical_maximum = dval;
343 				break;
344 			case 3:
345 				c->physical_minimum = dval;
346 				s->phyminsize = bSize;
347 				break;
348 			case 4:
349 				c->physical_maximum = dval;
350 				break;
351 			case 5:
352 				if ( dval > 7 && dval < 0x10)
353 					c->unit_exponent = -16 + dval;
354 				else
355 					c->unit_exponent = dval;
356 				break;
357 			case 6:
358 				c->unit = dval;
359 				break;
360 			case 7:
361 				c->report_size = dval;
362 				break;
363 			case 8:
364 				c->report_ID = dval;
365 				s->kindpos[hid_input] =
366 				    s->kindpos[hid_output] =
367 				    s->kindpos[hid_feature] = 0;
368 				break;
369 			case 9:
370 				c->report_count = dval;
371 				break;
372 			case 10: /* Push */
373 				hi = malloc(sizeof *hi);
374 				*hi = s->cur;
375 				c->next = hi;
376 				break;
377 			case 11: /* Pop */
378 				hi = c->next;
379 				s->cur = *hi;
380 				free(hi);
381 				break;
382 			default:
383 				return (-3);
384 			}
385 			break;
386 		case 2:		/* Local */
387 			switch (bTag) {
388 			case 0:
389 				c->usage = c->_usage_page | dval;
390 				if (s->nusage < MAXUSAGE)
391 					s->usages[s->nusage++] = c->usage;
392 				/* else XXX */
393 				break;
394 			case 1:
395 				s->minset = 1;
396 				c->usage_minimum = c->_usage_page | dval;
397 				break;
398 			case 2:
399 				c->usage_maximum = c->_usage_page | dval;
400 				break;
401 			case 3:
402 				c->designator_index = dval;
403 				break;
404 			case 4:
405 				c->designator_minimum = dval;
406 				break;
407 			case 5:
408 				c->designator_maximum = dval;
409 				break;
410 			case 7:
411 				c->string_index = dval;
412 				break;
413 			case 8:
414 				c->string_minimum = dval;
415 				break;
416 			case 9:
417 				c->string_maximum = dval;
418 				break;
419 			case 10:
420 				c->set_delimiter = dval;
421 				break;
422 			default:
423 				return (-4);
424 			}
425 			break;
426 		default:
427 			return (-5);
428 		}
429 	}
430 }
431 
432 int
433 hid_report_size(report_desc_t r, enum hid_kind k, int id)
434 {
435 	struct hid_data *d;
436 	hid_item_t h;
437 	int size;
438 
439 	_DIAGASSERT(r != NULL);
440 
441 	memset(&h, 0, sizeof h);
442 	size = 0;
443 	for (d = hid_start_parse(r, 1<<k, id); hid_get_item(d, &h); ) {
444 		if (h.report_ID == id && h.kind == k) {
445 			size = d->kindpos[k];
446 		}
447 	}
448 	hid_end_parse(d);
449 	return ((size + 7) / 8);
450 }
451 
452 int
453 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
454 	   hid_item_t *h, int id)
455 {
456 	hid_data_t d;
457 
458 	_DIAGASSERT(desc != NULL);
459 	_DIAGASSERT(h != NULL);
460 
461 	for (d = hid_start_parse(desc, 1<<k, id); hid_get_item(d, h); ) {
462 		if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
463 			hid_end_parse(d);
464 			return (1);
465 		}
466 	}
467 	hid_end_parse(d);
468 	h->report_size = 0;
469 	return (0);
470 }
471