xref: /freebsd/lib/libusbhid/parse.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*	$NetBSD: parse.c,v 1.11 2000/09/24 02:19:54 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 __FBSDID("$FreeBSD$");
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 	c->usage = 0;
80 	c->usage_minimum = 0;
81 	c->usage_maximum = 0;
82 	c->designator_index = 0;
83 	c->designator_minimum = 0;
84 	c->designator_maximum = 0;
85 	c->string_index = 0;
86 	c->string_minimum = 0;
87 	c->string_maximum = 0;
88 	c->set_delimiter = 0;
89 }
90 
91 hid_data_t
92 hid_start_parse(report_desc_t d, int kindset, int id)
93 {
94 	struct hid_data *s;
95 
96 	s = malloc(sizeof *s);
97 	memset(s, 0, sizeof *s);
98 	s->start = s->p = d->data;
99 	s->end = d->data + d->size;
100 	s->kindset = kindset;
101 	s->reportid = id;
102 	s->hassavedcoll = 0;
103 	return (s);
104 }
105 
106 void
107 hid_end_parse(hid_data_t s)
108 {
109 	while (s->cur.next) {
110 		hid_item_t *hi = s->cur.next->next;
111 		free(s->cur.next);
112 		s->cur.next = hi;
113 	}
114 	free(s);
115 }
116 
117 int
118 hid_get_item(hid_data_t s, hid_item_t *h)
119 {
120 	int r;
121 
122 	for (;;) {
123 		r = hid_get_item_raw(s, h);
124 		if (r <= 0)
125 			break;
126 		if (h->report_ID == s->reportid || s->reportid == -1)
127 			break;
128 	}
129 	return (r);
130 }
131 
132 #define REPORT_SAVED_COLL \
133 	do { \
134 		if (s->hassavedcoll) { \
135 			*h = s->savedcoll; \
136 			h->report_ID = c->report_ID; \
137 			s->hassavedcoll = 0; \
138 			return (1); \
139 		} \
140 	} while(/*LINTED*/ 0)
141 
142 static int
143 hid_get_item_raw(hid_data_t s, hid_item_t *h)
144 {
145 	hid_item_t *c;
146 	unsigned int bTag = 0, bType = 0, bSize;
147 	unsigned char *data;
148 	int dval;
149 	unsigned char *p;
150 	hid_item_t *hi;
151 	hid_item_t nc;
152 	int i;
153 	hid_kind_t retkind;
154 
155 	c = &s->cur;
156 
157  top:
158 	if (s->multimax) {
159 		REPORT_SAVED_COLL;
160 		if (c->logical_minimum >= c->logical_maximum) {
161 			if (s->logminsize == 1)
162 				c->logical_minimum =(int8_t)c->logical_minimum;
163 			else if (s->logminsize == 2)
164 				c->logical_minimum =(int16_t)c->logical_minimum;
165 		}
166 		if (s->multi < s->multimax) {
167 			c->usage = s->usages[min(s->multi, s->nusage-1)];
168 			s->multi++;
169 			*h = *c;
170 			/*
171 			 * 'multimax' is only non-zero if the current
172                          *  item kind is input/output/feature
173 			 */
174 			h->pos = s->kindpos[c->kind];
175 			s->kindpos[c->kind] += c->report_size;
176 			h->next = 0;
177 			return (1);
178 		} else {
179 			c->report_count = s->multimax;
180 			s->multimax = 0;
181 			s->nusage = 0;
182 			hid_clear_local(c);
183 		}
184 	}
185 	for (;;) {
186 		p = s->p;
187 		if (p >= s->end)
188 			return (0);
189 
190 		bSize = *p++;
191 		if (bSize == 0xfe) {
192 			/* long item */
193 			bSize = *p++;
194 			bSize |= *p++ << 8;
195 			bTag = *p++;
196 			data = p;
197 			p += bSize;
198 		} else {
199 			/* short item */
200 			bTag = bSize >> 4;
201 			bType = (bSize >> 2) & 3;
202 			bSize &= 3;
203 			if (bSize == 3) bSize = 4;
204 			data = p;
205 			p += bSize;
206 		}
207 		s->p = p;
208 		/*
209 		 * The spec is unclear if the data is signed or unsigned.
210 		 */
211 		switch(bSize) {
212 		case 0:
213 			dval = 0;
214 			break;
215 		case 1:
216 			dval = *data++;
217 			break;
218 		case 2:
219 			dval = *data++;
220 			dval |= *data++ << 8;
221 			break;
222 		case 4:
223 			dval = *data++;
224 			dval |= *data++ << 8;
225 			dval |= *data++ << 16;
226 			dval |= *data++ << 24;
227 			break;
228 		default:
229 			return (-1);
230 		}
231 
232 		switch (bType) {
233 		case 0:			/* Main */
234 			switch (bTag) {
235 			case 8:		/* Input */
236 				retkind = hid_input;
237 			ret:
238 				if (!(s->kindset & (1 << retkind))) {
239 					/* Drop the items of this kind */
240 					s->nusage = 0;
241 					continue;
242 				}
243 				c->kind = retkind;
244 				c->flags = dval;
245 				if (c->flags & HIO_VARIABLE) {
246 					s->multimax = c->report_count;
247 					s->multi = 0;
248 					c->report_count = 1;
249 					if (s->minset) {
250 						for (i = c->usage_minimum;
251 						     i <= c->usage_maximum;
252 						     i++) {
253 							s->usages[s->nusage] = i;
254 							if (s->nusage < MAXUSAGE-1)
255 								s->nusage++;
256 						}
257 						c->usage_minimum = 0;
258 						c->usage_maximum = 0;
259 						s->minset = 0;
260 					}
261 					goto top;
262 				} else {
263 					if (s->minset)
264 						c->usage = c->usage_minimum;
265 					*h = *c;
266 					h->next = 0;
267 					h->pos = s->kindpos[c->kind];
268 					s->kindpos[c->kind] +=
269 					    c->report_size * c->report_count;
270 					hid_clear_local(c);
271 					s->minset = 0;
272 					return (1);
273 				}
274 			case 9:		/* Output */
275 				retkind = hid_output;
276 				goto ret;
277 			case 10:	/* Collection */
278 				c->kind = hid_collection;
279 				c->collection = dval;
280 				c->collevel++;
281 				nc = *c;
282 				hid_clear_local(c);
283 				/*c->report_ID = NO_REPORT_ID;*/
284 				s->nusage = 0;
285 				if (s->hassavedcoll) {
286 					*h = s->savedcoll;
287 					h->report_ID = nc.report_ID;
288 					s->savedcoll = nc;
289 					return (1);
290 				} else {
291 					s->hassavedcoll = 1;
292 					s->savedcoll = nc;
293 				}
294 				break;
295 			case 11:	/* Feature */
296 				retkind = hid_feature;
297 				goto ret;
298 			case 12:	/* End collection */
299 				REPORT_SAVED_COLL;
300 				c->kind = hid_endcollection;
301 				c->collevel--;
302 				*h = *c;
303 				/*hid_clear_local(c);*/
304 				s->nusage = 0;
305 				return (1);
306 			default:
307 				return (-2);
308 			}
309 			break;
310 
311 		case 1:		/* Global */
312 			switch (bTag) {
313 			case 0:
314 				c->_usage_page = dval << 16;
315 				break;
316 			case 1:
317 				c->logical_minimum = dval;
318 				s->logminsize = bSize;
319 				break;
320 			case 2:
321 				c->logical_maximum = dval;
322 				break;
323 			case 3:
324 				c->physical_maximum = dval;
325 				break;
326 			case 4:
327 				c->physical_maximum = dval;
328 				break;
329 			case 5:
330 				c->unit_exponent = dval;
331 				break;
332 			case 6:
333 				c->unit = dval;
334 				break;
335 			case 7:
336 				c->report_size = dval;
337 				break;
338 			case 8:
339 				c->report_ID = dval;
340 				s->kindpos[hid_input] =
341 				    s->kindpos[hid_output] =
342 				    s->kindpos[hid_feature] = 0;
343 				break;
344 			case 9:
345 				c->report_count = dval;
346 				break;
347 			case 10: /* Push */
348 				hi = malloc(sizeof *hi);
349 				*hi = s->cur;
350 				c->next = hi;
351 				break;
352 			case 11: /* Pop */
353 				hi = c->next;
354 				s->cur = *hi;
355 				free(hi);
356 				break;
357 			default:
358 				return (-3);
359 			}
360 			break;
361 		case 2:		/* Local */
362 			switch (bTag) {
363 			case 0:
364 				c->usage = c->_usage_page | dval;
365 				if (s->nusage < MAXUSAGE)
366 					s->usages[s->nusage++] = c->usage;
367 				/* else XXX */
368 				break;
369 			case 1:
370 				s->minset = 1;
371 				c->usage_minimum = c->_usage_page | dval;
372 				break;
373 			case 2:
374 				c->usage_maximum = c->_usage_page | dval;
375 				break;
376 			case 3:
377 				c->designator_index = dval;
378 				break;
379 			case 4:
380 				c->designator_minimum = dval;
381 				break;
382 			case 5:
383 				c->designator_maximum = dval;
384 				break;
385 			case 7:
386 				c->string_index = dval;
387 				break;
388 			case 8:
389 				c->string_minimum = dval;
390 				break;
391 			case 9:
392 				c->string_maximum = dval;
393 				break;
394 			case 10:
395 				c->set_delimiter = dval;
396 				break;
397 			default:
398 				return (-4);
399 			}
400 			break;
401 		default:
402 			return (-5);
403 		}
404 	}
405 }
406 
407 int
408 hid_report_size(report_desc_t r, enum hid_kind k, int id)
409 {
410 	struct hid_data *d;
411 	hid_item_t h;
412 	int size;
413 
414 	memset(&h, 0, sizeof h);
415 	size = 0;
416 	for (d = hid_start_parse(r, 1<<k, id); hid_get_item(d, &h); ) {
417 		if (h.report_ID == id && h.kind == k) {
418 			size = d->kindpos[k];
419 		}
420 	}
421 	hid_end_parse(d);
422 	return ((size + 7) / 8);
423 }
424 
425 int
426 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
427 	   hid_item_t *h, int id)
428 {
429 	hid_data_t d;
430 
431 	for (d = hid_start_parse(desc, 1<<k, id); hid_get_item(d, h); ) {
432 		if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
433 			hid_end_parse(d);
434 			return (1);
435 		}
436 	}
437 	hid_end_parse(d);
438 	h->report_size = 0;
439 	return (0);
440 }
441