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 <assert.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <sys/time.h>
33 
34 #include "usbhid.h"
35 #include "usbvar.h"
36 #include "usbcompat.h"
37 
38 #define MAXUSAGE 100
39 struct hid_data {
40 	unsigned char *start;
41    unsigned char *end;
42    unsigned char *p;
43 	hid_item_t cur;
44 	unsigned int usages[MAXUSAGE];
45 	int nusage;
46 	int minset;
47 	int logminsize;
48 	int multi;
49 	int multimax;
50 	int kindset;
51 	int reportid;
52 
53 	/*
54 	 * The start of collection item has no report ID set, so save
55 	 * it until we know the ID.
56 	 */
57 	hid_item_t savedcoll;
58    unsigned char hassavedcoll;
59 	/*
60 	 * Absolute data position (bits) for input/output/feature.
61 	 *  Assumes that hid_input, hid_output and hid_feature have
62 	 *  values 0, 1 and 2.
63 	 */
64 	unsigned int kindpos[3];
65 };
66 
min(int x,int y)67 static int min(int x, int y) { return x < y ? x : y; }
68 
69 static int hid_get_item_raw(hid_data_t s, hid_item_t *h);
70 
71 static void
hid_clear_local(hid_item_t * c)72 hid_clear_local(hid_item_t *c)
73 {
74 	c->usage = 0;
75 	c->usage_minimum = 0;
76 	c->usage_maximum = 0;
77 	c->designator_index = 0;
78 	c->designator_minimum = 0;
79 	c->designator_maximum = 0;
80 	c->string_index = 0;
81 	c->string_minimum = 0;
82 	c->string_maximum = 0;
83 	c->set_delimiter = 0;
84 }
85 
86 hid_data_t
hid_start_parse(report_desc_t d,int kindset,int id)87 hid_start_parse(report_desc_t d, int kindset, int id)
88 {
89 	struct hid_data *s;
90 
91 	s = (struct hid_data *)malloc(sizeof *s);
92 	memset(s, 0, sizeof *s);
93 	s->start = s->p = d->data;
94 	s->end = d->data + d->size;
95 	s->kindset = kindset;
96 	s->reportid = id;
97 	s->hassavedcoll = 0;
98 	return (s);
99 }
100 
101 void
hid_end_parse(hid_data_t s)102 hid_end_parse(hid_data_t s)
103 {
104 	while (s->cur.next) {
105 		hid_item_t *hi = s->cur.next->next;
106 		free(s->cur.next);
107 		s->cur.next = hi;
108 	}
109 	free(s);
110 }
111 
112 int
hid_get_item(hid_data_t s,hid_item_t * h)113 hid_get_item(hid_data_t s, hid_item_t *h)
114 {
115 	int r;
116 
117 	for (;;) {
118 		r = hid_get_item_raw(s, h);
119 		if (r <= 0)
120 			break;
121 		if (h->report_ID == s->reportid || s->reportid == -1)
122 			break;
123 	}
124 	return (r);
125 }
126 
127 #define REPORT_SAVED_COLL \
128 	do { \
129 		if (s->hassavedcoll) { \
130 			*h = s->savedcoll; \
131 			h->report_ID = c->report_ID; \
132 			s->hassavedcoll = 0; \
133 			return (1); \
134 		} \
135 	} while(/*LINTED*/ 0)
136 
137 static int
hid_get_item_raw(hid_data_t s,hid_item_t * h)138 hid_get_item_raw(hid_data_t s, hid_item_t *h)
139 {
140 	hid_item_t *c;
141 	unsigned int bTag = 0, bType = 0, bSize;
142 	unsigned char *data;
143 	unsigned int dval;
144 	unsigned char *p;
145 	hid_item_t *hi;
146 	hid_item_t nc;
147 	unsigned int i;
148 	hid_kind_t retkind;
149 
150 	c = &s->cur;
151 
152  top:
153 	if (s->multimax) {
154 		REPORT_SAVED_COLL;
155 		if (c->logical_minimum >= c->logical_maximum) {
156 			if (s->logminsize == 1)
157 				c->logical_minimum =(signed char)c->logical_minimum;
158 			else if (s->logminsize == 2)
159 				c->logical_minimum =(signed short)c->logical_minimum;
160 		}
161 		if (s->multi < s->multimax) {
162 			c->usage = s->usages[min(s->multi, s->nusage-1)];
163 			s->multi++;
164 			*h = *c;
165 			/*
166 			 * 'multimax' is only non-zero if the current
167                          *  item kind is input/output/feature
168 			 */
169 			h->pos = s->kindpos[c->kind];
170 			s->kindpos[c->kind] += c->report_size;
171 			h->next = 0;
172 			return (1);
173 		} else {
174 			c->report_count = s->multimax;
175 			s->multimax = 0;
176 			s->nusage = 0;
177 			hid_clear_local(c);
178 		}
179 	}
180 	for (;;) {
181 		p = s->p;
182 		if (p >= s->end)
183 			return (0);
184 
185 		bSize = *p++;
186 		if (bSize == 0xfe) {
187 			/* long item */
188 			bSize = *p++;
189 			bSize |= *p++ << 8;
190 			bTag = *p++;
191 			data = p;
192 			p += bSize;
193 		} else {
194 			/* short item */
195 			bTag = bSize >> 4;
196 			bType = (bSize >> 2) & 3;
197 			bSize &= 3;
198 			if (bSize == 3) bSize = 4;
199 			data = p;
200 			p += bSize;
201 		}
202 		s->p = p;
203 		/*
204 		 * The spec is unclear if the data is signed or unsigned.
205 		 */
206 		switch(bSize) {
207 		case 0:
208 			dval = 0;
209 			break;
210 		case 1:
211 			dval = *data++;
212 			break;
213 		case 2:
214 			dval = *data++;
215 			dval |= *data++ << 8;
216 			break;
217 		case 4:
218 			dval = *data++;
219 			dval |= *data++ << 8;
220 			dval |= *data++ << 16;
221 			dval |= *data++ << 24;
222 			break;
223 		default:
224 			return (-1);
225 		}
226 
227 		switch (bType) {
228 		case 0:			/* Main */
229 			switch (bTag) {
230 			case 8:		/* Input */
231 				retkind = hid_input;
232 			ret:
233 				if (!(s->kindset & (1 << retkind))) {
234 					/* Drop the items of this kind */
235 					s->nusage = 0;
236 					continue;
237 				}
238 				c->kind = retkind;
239 				c->flags = dval;
240 				if (c->flags & HIO_VARIABLE) {
241 					s->multimax = c->report_count;
242 					s->multi = 0;
243 					c->report_count = 1;
244 					if (s->minset) {
245 						for (i = c->usage_minimum;
246 						     i <= c->usage_maximum;
247 						     i++) {
248 							s->usages[s->nusage] = i;
249 							if (s->nusage < MAXUSAGE-1)
250 								s->nusage++;
251 						}
252 						c->usage_minimum = 0;
253 						c->usage_maximum = 0;
254 						s->minset = 0;
255 					}
256 					goto top;
257 				} else {
258 					if (s->minset)
259 						c->usage = c->usage_minimum;
260 					*h = *c;
261 					h->next = 0;
262 					h->pos = s->kindpos[c->kind];
263 					s->kindpos[c->kind] +=
264 					    c->report_size * c->report_count;
265 					hid_clear_local(c);
266 					s->minset = 0;
267 					return (1);
268 				}
269 			case 9:		/* Output */
270 				retkind = hid_output;
271 				goto ret;
272 			case 10:	/* Collection */
273 				c->kind = hid_collection;
274 				c->collection = dval;
275 				c->collevel++;
276 				nc = *c;
277 				hid_clear_local(c);
278 				/*c->report_ID = NO_REPORT_ID;*/
279 				s->nusage = 0;
280 				if (s->hassavedcoll) {
281 					*h = s->savedcoll;
282 					h->report_ID = nc.report_ID;
283 					s->savedcoll = nc;
284 					return (1);
285 				} else {
286 					s->hassavedcoll = 1;
287 					s->savedcoll = nc;
288 				}
289 				break;
290 			case 11:	/* Feature */
291 				retkind = hid_feature;
292 				goto ret;
293 			case 12:	/* End collection */
294 				REPORT_SAVED_COLL;
295 				c->kind = hid_endcollection;
296 				c->collevel--;
297 				*h = *c;
298 				/*hid_clear_local(c);*/
299 				s->nusage = 0;
300 				return (1);
301 			default:
302 				return (-2);
303 			}
304 			break;
305 
306 		case 1:		/* Global */
307 			switch (bTag) {
308 			case 0:
309 				c->_usage_page = dval << 16;
310 				break;
311 			case 1:
312 				c->logical_minimum = dval;
313 				s->logminsize = bSize;
314 				break;
315 			case 2:
316 				c->logical_maximum = dval;
317 				break;
318 			case 3:
319 				c->physical_minimum = dval;
320 				break;
321 			case 4:
322 				c->physical_maximum = dval;
323 				break;
324 			case 5:
325 				c->unit_exponent = dval;
326 				break;
327 			case 6:
328 				c->unit = dval;
329 				break;
330 			case 7:
331 				c->report_size = dval;
332 				break;
333 			case 8:
334 				c->report_ID = dval;
335 				s->kindpos[hid_input] =
336 				    s->kindpos[hid_output] =
337 				    s->kindpos[hid_feature] = 0;
338 				break;
339 			case 9:
340 				c->report_count = dval;
341 				break;
342 			case 10: /* Push */
343 				hi = (hid_item_t *)malloc(sizeof *hi);
344 				*hi = s->cur;
345 				c->next = hi;
346 				break;
347 			case 11: /* Pop */
348 				hi = c->next;
349 				s->cur = *hi;
350 				free(hi);
351 				break;
352 			default:
353 				return (-3);
354 			}
355 			break;
356 		case 2:		/* Local */
357 			switch (bTag) {
358 			case 0:
359 				c->usage = c->_usage_page | dval;
360 				if (s->nusage < MAXUSAGE)
361 					s->usages[s->nusage++] = c->usage;
362 				/* else XXX */
363 				break;
364 			case 1:
365 				s->minset = 1;
366 				c->usage_minimum = c->_usage_page | dval;
367 				break;
368 			case 2:
369 				c->usage_maximum = c->_usage_page | dval;
370 				break;
371 			case 3:
372 				c->designator_index = dval;
373 				break;
374 			case 4:
375 				c->designator_minimum = dval;
376 				break;
377 			case 5:
378 				c->designator_maximum = dval;
379 				break;
380 			case 7:
381 				c->string_index = dval;
382 				break;
383 			case 8:
384 				c->string_minimum = dval;
385 				break;
386 			case 9:
387 				c->string_maximum = dval;
388 				break;
389 			case 10:
390 				c->set_delimiter = dval;
391 				break;
392 			default:
393 				return (-4);
394 			}
395 			break;
396 		default:
397 			return (-5);
398 		}
399 	}
400 }
401 
402 int
hid_report_size(report_desc_t r,enum hid_kind k,int id)403 hid_report_size(report_desc_t r, enum hid_kind k, int id)
404 {
405 	struct hid_data *d;
406 	hid_item_t h;
407 	int size;
408 
409 	memset(&h, 0, sizeof h);
410 	size = 0;
411 	for (d = hid_start_parse(r, 1<<k, id); hid_get_item(d, &h); ) {
412 		if (h.report_ID == id && h.kind == k) {
413 			size = d->kindpos[k];
414 		}
415 	}
416 	hid_end_parse(d);
417 	return ((size + 7) / 8);
418 }
419 
420 int
hid_locate(report_desc_t desc,unsigned int u,enum hid_kind k,hid_item_t * h,int id)421 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
422 	   hid_item_t *h, int id)
423 {
424 	hid_data_t d;
425 
426 	for (d = hid_start_parse(desc, 1<<k, id); hid_get_item(d, h); ) {
427 		if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
428 			hid_end_parse(d);
429 			return (1);
430 		}
431 	}
432 	hid_end_parse(d);
433 	h->report_size = 0;
434 	return (0);
435 }
436