xref: /freebsd/lib/libusbhid/parse.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 	c->report_size = 0;
90 }
91 
92 hid_data_t
93 hid_start_parse(report_desc_t d, int kindset, int id)
94 {
95 	struct hid_data *s;
96 
97 	s = malloc(sizeof *s);
98 	memset(s, 0, sizeof *s);
99 	s->start = s->p = d->data;
100 	s->end = d->data + d->size;
101 	s->kindset = kindset;
102 	s->reportid = id;
103 	s->hassavedcoll = 0;
104 	return (s);
105 }
106 
107 void
108 hid_end_parse(hid_data_t s)
109 {
110 	while (s->cur.next) {
111 		hid_item_t *hi = s->cur.next->next;
112 		free(s->cur.next);
113 		s->cur.next = hi;
114 	}
115 	free(s);
116 }
117 
118 int
119 hid_get_item(hid_data_t s, hid_item_t *h)
120 {
121 	int r;
122 
123 	for (;;) {
124 		r = hid_get_item_raw(s, h);
125 		if (r <= 0)
126 			break;
127 		if (h->report_ID == s->reportid || s->reportid == -1)
128 			break;
129 	}
130 	return (r);
131 }
132 
133 #define REPORT_SAVED_COLL \
134 	do { \
135 		if (s->hassavedcoll) { \
136 			*h = s->savedcoll; \
137 			h->report_ID = c->report_ID; \
138 			s->hassavedcoll = 0; \
139 			return (1); \
140 		} \
141 	} while(/*LINTED*/ 0)
142 
143 static int
144 hid_get_item_raw(hid_data_t s, hid_item_t *h)
145 {
146 	hid_item_t *c;
147 	unsigned int bTag = 0, bType = 0, bSize;
148 	unsigned char *data;
149 	int dval;
150 	unsigned char *p;
151 	hid_item_t *hi;
152 	hid_item_t nc;
153 	int i;
154 	hid_kind_t retkind;
155 
156 	c = &s->cur;
157 
158  top:
159 	if (s->multimax) {
160 		REPORT_SAVED_COLL;
161 		if (c->logical_minimum >= c->logical_maximum) {
162 			if (s->logminsize == 1)
163 				c->logical_minimum =(int8_t)c->logical_minimum;
164 			else if (s->logminsize == 2)
165 				c->logical_minimum =(int16_t)c->logical_minimum;
166 		}
167 		if (s->multi < s->multimax) {
168 			c->usage = s->usages[min(s->multi, s->nusage-1)];
169 			s->multi++;
170 			*h = *c;
171 			/*
172 			 * 'multimax' is only non-zero if the current
173                          *  item kind is input/output/feature
174 			 */
175 			h->pos = s->kindpos[c->kind];
176 			s->kindpos[c->kind] += c->report_size;
177 			h->next = 0;
178 			return (1);
179 		} else {
180 			c->report_count = s->multimax;
181 			s->multimax = 0;
182 			s->nusage = 0;
183 			hid_clear_local(c);
184 		}
185 	}
186 	for (;;) {
187 		p = s->p;
188 		if (p >= s->end)
189 			return (0);
190 
191 		bSize = *p++;
192 		if (bSize == 0xfe) {
193 			/* long item */
194 			bSize = *p++;
195 			bSize |= *p++ << 8;
196 			bTag = *p++;
197 			data = p;
198 			p += bSize;
199 		} else {
200 			/* short item */
201 			bTag = bSize >> 4;
202 			bType = (bSize >> 2) & 3;
203 			bSize &= 3;
204 			if (bSize == 3) bSize = 4;
205 			data = p;
206 			p += bSize;
207 		}
208 		s->p = p;
209 		/*
210 		 * The spec is unclear if the data is signed or unsigned.
211 		 */
212 		switch(bSize) {
213 		case 0:
214 			dval = 0;
215 			break;
216 		case 1:
217 			dval = (int8_t)*data++;
218 			break;
219 		case 2:
220 			dval = *data++;
221 			dval |= *data++ << 8;
222 			dval = (int16_t)dval;
223 			break;
224 		case 4:
225 			dval = *data++;
226 			dval |= *data++ << 8;
227 			dval |= *data++ << 16;
228 			dval |= *data++ << 24;
229 			break;
230 		default:
231 			return (-1);
232 		}
233 
234 		switch (bType) {
235 		case 0:			/* Main */
236 			switch (bTag) {
237 			case 8:		/* Input */
238 				retkind = hid_input;
239 			ret:
240 				if (!(s->kindset & (1 << retkind))) {
241 					/* Drop the items of this kind */
242 					s->nusage = 0;
243 					continue;
244 				}
245 				c->kind = retkind;
246 				c->flags = dval;
247 				if (c->flags & HIO_VARIABLE) {
248 					s->multimax = c->report_count;
249 					s->multi = 0;
250 					c->report_count = 1;
251 					if (s->minset) {
252 						for (i = c->usage_minimum;
253 						     i <= c->usage_maximum;
254 						     i++) {
255 							s->usages[s->nusage] = i;
256 							if (s->nusage < MAXUSAGE-1)
257 								s->nusage++;
258 						}
259 						c->usage_minimum = 0;
260 						c->usage_maximum = 0;
261 						s->minset = 0;
262 					}
263 					goto top;
264 				} else {
265 					if (s->minset)
266 						c->usage = c->usage_minimum;
267 					*h = *c;
268 					h->next = 0;
269 					h->pos = s->kindpos[c->kind];
270 					s->kindpos[c->kind] +=
271 					    c->report_size * c->report_count;
272 					hid_clear_local(c);
273 					s->minset = 0;
274 					return (1);
275 				}
276 			case 9:		/* Output */
277 				retkind = hid_output;
278 				goto ret;
279 			case 10:	/* Collection */
280 				c->kind = hid_collection;
281 				c->collection = dval;
282 				c->collevel++;
283 				nc = *c;
284 				hid_clear_local(c);
285 				/*c->report_ID = NO_REPORT_ID;*/
286 				s->nusage = 0;
287 				if (s->hassavedcoll) {
288 					*h = s->savedcoll;
289 					h->report_ID = nc.report_ID;
290 					s->savedcoll = nc;
291 					return (1);
292 				} else {
293 					s->hassavedcoll = 1;
294 					s->savedcoll = nc;
295 				}
296 				break;
297 			case 11:	/* Feature */
298 				retkind = hid_feature;
299 				goto ret;
300 			case 12:	/* End collection */
301 				REPORT_SAVED_COLL;
302 				c->kind = hid_endcollection;
303 				c->collevel--;
304 				*h = *c;
305 				/*hid_clear_local(c);*/
306 				s->nusage = 0;
307 				return (1);
308 			default:
309 				return (-2);
310 			}
311 			break;
312 
313 		case 1:		/* Global */
314 			switch (bTag) {
315 			case 0:
316 				c->_usage_page = dval << 16;
317 				break;
318 			case 1:
319 				c->logical_minimum = dval;
320 				s->logminsize = bSize;
321 				break;
322 			case 2:
323 				c->logical_maximum = dval;
324 				break;
325 			case 3:
326 				c->physical_maximum = dval;
327 				break;
328 			case 4:
329 				c->physical_maximum = dval;
330 				break;
331 			case 5:
332 				c->unit_exponent = dval;
333 				break;
334 			case 6:
335 				c->unit = dval;
336 				break;
337 			case 7:
338 				c->report_size = dval;
339 				break;
340 			case 8:
341 				c->report_ID = dval;
342 				s->kindpos[hid_input] =
343 				    s->kindpos[hid_output] =
344 				    s->kindpos[hid_feature] = 0;
345 				break;
346 			case 9:
347 				c->report_count = dval;
348 				break;
349 			case 10: /* Push */
350 				hi = malloc(sizeof *hi);
351 				*hi = s->cur;
352 				c->next = hi;
353 				break;
354 			case 11: /* Pop */
355 				hi = c->next;
356 				s->cur = *hi;
357 				free(hi);
358 				break;
359 			default:
360 				return (-3);
361 			}
362 			break;
363 		case 2:		/* Local */
364 			switch (bTag) {
365 			case 0:
366 				c->usage = c->_usage_page | dval;
367 				if (s->nusage < MAXUSAGE)
368 					s->usages[s->nusage++] = c->usage;
369 				/* else XXX */
370 				break;
371 			case 1:
372 				s->minset = 1;
373 				c->usage_minimum = c->_usage_page | dval;
374 				break;
375 			case 2:
376 				c->usage_maximum = c->_usage_page | dval;
377 				break;
378 			case 3:
379 				c->designator_index = dval;
380 				break;
381 			case 4:
382 				c->designator_minimum = dval;
383 				break;
384 			case 5:
385 				c->designator_maximum = dval;
386 				break;
387 			case 7:
388 				c->string_index = dval;
389 				break;
390 			case 8:
391 				c->string_minimum = dval;
392 				break;
393 			case 9:
394 				c->string_maximum = dval;
395 				break;
396 			case 10:
397 				c->set_delimiter = dval;
398 				break;
399 			default:
400 				return (-4);
401 			}
402 			break;
403 		default:
404 			return (-5);
405 		}
406 	}
407 }
408 
409 int
410 hid_report_size(report_desc_t r, enum hid_kind k, int id)
411 {
412 	struct hid_data *d;
413 	hid_item_t h;
414 	int size;
415 
416 	memset(&h, 0, sizeof h);
417 	size = 0;
418 	for (d = hid_start_parse(r, 1<<k, id); hid_get_item(d, &h); ) {
419 		if (h.report_ID == id && h.kind == k) {
420 			size = d->kindpos[k];
421 		}
422 	}
423 	hid_end_parse(d);
424 	return ((size + 7) / 8);
425 }
426 
427 int
428 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
429 	   hid_item_t *h, int id)
430 {
431 	hid_data_t d;
432 
433 	for (d = hid_start_parse(desc, 1<<k, id); hid_get_item(d, h); ) {
434 		if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
435 			hid_end_parse(d);
436 			return (1);
437 		}
438 	}
439 	hid_end_parse(d);
440 	h->report_size = 0;
441 	return (0);
442 }
443