lib/libusbhid/parse.c

   1 /*      $NetBSD: parse.c,v 1.11 2000/09/24 02:19:54 augustss Exp $      */
   2
   3 /*
   4  * Copyright (c) 1999 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  * $FreeBSD: src/lib/libusbhid/parse.c,v 1.6.2.1 2002/04/03 15:54:00 joe Exp $
  29  * $DragonFly: src/lib/libusbhid/parse.c,v 1.3 2003/08/08 04:18:35 dillon Exp $
  30  */
  31
  32 #include <assert.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <sys/time.h>
  36
  37 #include <bus/usb/usb.h>
  38 #include <bus/usb/usbhid.h>
  39
  40 #include "libusbhid.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 multi;
  53         int multimax;
  54         int kindset;
  55
  56         /* Absolute data position (bits) for input/output/feature.
  57            Assumes that hid_input, hid_output and hid_feature have
  58            values 0, 1 and 2. */
  59         unsigned int kindpos[3];
  60 };
  61
  62 static int min(int x, int y) { return x < y ? x : y; }
  63
  64 static void
  65 hid_clear_local(hid_item_t *c)
  66 {
  67         c->usage = 0;
  68         c->usage_minimum = 0;
  69         c->usage_maximum = 0;
  70         c->designator_index = 0;
  71         c->designator_minimum = 0;
  72         c->designator_maximum = 0;
  73         c->string_index = 0;
  74         c->string_minimum = 0;
  75         c->string_maximum = 0;
  76         c->set_delimiter = 0;
  77 }
  78
  79 hid_data_t
  80 hid_start_parse(report_desc_t d, int kindset)
  81 {
  82         struct hid_data *s;
  83
  84         s = malloc(sizeof *s);
  85         memset(s, 0, sizeof *s);
  86         s->start = s->p = d->data;
  87         s->end = d->data + d->size;
  88         s->kindset = kindset;
  89         return (s);
  90 }
  91
  92 void
  93 hid_end_parse(hid_data_t s)
  94 {
  95         while (s->cur.next) {
  96                 hid_item_t *hi = s->cur.next->next;
  97                 free(s->cur.next);
  98                 s->cur.next = hi;
  99         }
 100         free(s);
 101 }
 102
 103 int
 104 hid_get_item(hid_data_t s, hid_item_t *h)
 105 {
 106         hid_item_t *c;
 107         unsigned int bTag = 0, bType = 0, bSize;
 108         unsigned char *data;
 109         int dval;
 110         unsigned char *p;
 111         hid_item_t *hi;
 112         int i;
 113         hid_kind_t retkind;
 114
 115         c = &s->cur;
 116
 117  top:
 118         if (s->multimax) {
 119                 if (s->multi < s->multimax) {
 120                         c->usage = s->usages[min(s->multi, s->nusage-1)];
 121                         s->multi++;
 122                         *h = *c;
 123
 124                         /* 'multimax' is only non-zero if the current
 125                            item kind is input/output/feature */
 126                         h->pos = s->kindpos[c->kind];
 127                         s->kindpos[c->kind] += c->report_size;
 128                         h->next = 0;
 129                         return (1);
 130                 } else {
 131                         c->report_count = s->multimax;
 132                         s->multimax = 0;
 133                         s->nusage = 0;
 134                         hid_clear_local(c);
 135                 }
 136         }
 137         for (;;) {
 138                 p = s->p;
 139                 if (p >= s->end)
 140                         return (0);
 141
 142                 bSize = *p++;
 143                 if (bSize == 0xfe) {
 144                         /* long item */
 145                         bSize = *p++;
 146                         bSize |= *p++ << 8;
 147                         bTag = *p++;
 148                         data = p;
 149                         p += bSize;
 150                 } else {
 151                         /* short item */
 152                         bTag = bSize >> 4;
 153                         bType = (bSize >> 2) & 3;
 154                         bSize &= 3;
 155                         if (bSize == 3) bSize = 4;
 156                         data = p;
 157                         p += bSize;
 158                 }
 159                 s->p = p;
 160                 /*
 161                  * The spec is unclear if the data is signed or unsigned.
 162                  */
 163                 switch(bSize) {
 164                 case 0:
 165                         dval = 0;
 166                         break;
 167                 case 1:
 168                         dval = (int8_t)*data++;
 169                         break;
 170                 case 2:
 171                         dval = *data++;
 172                         dval |= *data++ << 8;
 173                         dval = (int16_t)dval;
 174                         break;
 175                 case 4:
 176                         dval = *data++;
 177                         dval |= *data++ << 8;
 178                         dval |= *data++ << 16;
 179                         dval |= *data++ << 24;
 180                         break;
 181                 default:
 182                         return (-1);
 183                 }
 184
 185                 switch (bType) {
 186                 case 0:                 /* Main */
 187                         switch (bTag) {
 188                         case 8:         /* Input */
 189                                 retkind = hid_input;
 190                         ret:
 191                                 if (!(s->kindset & (1 << retkind))) {
 192                                         /* Drop the items of this kind */
 193                                         s->nusage = 0;
 194                                         continue;
 195                                 }
 196                                 c->kind = retkind;
 197                                 c->flags = dval;
 198                                 if (c->flags & HIO_VARIABLE) {
 199                                         s->multimax = c->report_count;
 200                                         s->multi = 0;
 201                                         c->report_count = 1;
 202                                         if (s->minset) {
 203                                                 for (i = c->usage_minimum;
 204                                                      i <= c->usage_maximum;
 205                                                      i++) {
 206                                                         s->usages[s->nusage] = i;
 207                                                         if (s->nusage < MAXUSAGE-1)
 208                                                                 s->nusage++;
 209                                                 }
 210                                                 s->minset = 0;
 211                                         }
 212                                         goto top;
 213                                 } else {
 214                                         if (s->minset)
 215                                                 c->usage = c->usage_minimum;
 216                                         *h = *c;
 217                                         h->next = 0;
 218                                         h->pos = s->kindpos[c->kind];
 219                                         s->kindpos[c->kind] += c->report_size * c->report_count;
 220                                         hid_clear_local(c);
 221                                         s->minset = 0;
 222                                         return (1);
 223                                 }
 224                         case 9:         /* Output */
 225                                 retkind = hid_output;
 226                                 goto ret;
 227                         case 10:        /* Collection */
 228                                 c->kind = hid_collection;
 229                                 c->collection = dval;
 230                                 c->collevel++;
 231                                 *h = *c;
 232                                 hid_clear_local(c);
 233                                 c->report_ID = NO_REPORT_ID;
 234                                 s->nusage = 0;
 235                                 return (1);
 236                         case 11:        /* Feature */
 237                                 retkind = hid_feature;
 238                                 goto ret;
 239                         case 12:        /* End collection */
 240                                 c->kind = hid_endcollection;
 241                                 c->collevel--;
 242                                 *h = *c;
 243                                 /*hid_clear_local(c);*/
 244                                 s->nusage = 0;
 245                                 return (1);
 246                         default:
 247                                 return (-2);
 248                         }
 249
 250                 case 1:         /* Global */
 251                         switch (bTag) {
 252                         case 0:
 253                                 c->_usage_page = dval << 16;
 254                                 break;
 255                         case 1:
 256                                 c->logical_minimum = dval;
 257                                 break;
 258                         case 2:
 259                                 c->logical_maximum = dval;
 260                                 break;
 261                         case 3:
 262                                 c->physical_maximum = dval;
 263                                 break;
 264                         case 4:
 265                                 c->physical_maximum = dval;
 266                                 break;
 267                         case 5:
 268                                 c->unit_exponent = dval;
 269                                 break;
 270                         case 6:
 271                                 c->unit = dval;
 272                                 break;
 273                         case 7:
 274                                 c->report_size = dval;
 275                                 break;
 276                         case 8:
 277                                 c->report_ID = dval;
 278                                 break;
 279                         case 9:
 280                                 c->report_count = dval;
 281                                 break;
 282                         case 10: /* Push */
 283                                 hi = malloc(sizeof *hi);
 284                                 *hi = s->cur;
 285                                 c->next = hi;
 286                                 break;
 287                         case 11: /* Pop */
 288                                 hi = c->next;
 289                                 s->cur = *hi;
 290                                 free(hi);
 291                                 break;
 292                         default:
 293                                 return (-3);
 294                         }
 295                         break;
 296                 case 2:         /* Local */
 297                         switch (bTag) {
 298                         case 0:
 299                                 if (bSize == 1)
 300                                         dval = c->_usage_page | (dval&0xff);
 301                                 else if (bSize == 2)
 302                                         dval = c->_usage_page | (dval&0xffff);
 303                                 c->usage = dval;
 304                                 if (s->nusage < MAXUSAGE)
 305                                         s->usages[s->nusage++] = dval;
 306                                 /* else XXX */
 307                                 break;
 308                         case 1:
 309                                 s->minset = 1;
 310                                 if (bSize == 1)
 311                                         dval = c->_usage_page | (dval&0xff);
 312                                 else if (bSize == 2)
 313                                         dval = c->_usage_page | (dval&0xffff);
 314                                 c->usage_minimum = dval;
 315                                 break;
 316                         case 2:
 317                                 if (bSize == 1)
 318                                         dval = c->_usage_page | (dval&0xff);
 319                                 else if (bSize == 2)
 320                                         dval = c->_usage_page | (dval&0xffff);
 321                                 c->usage_maximum = dval;
 322                                 break;
 323                         case 3:
 324                                 c->designator_index = dval;
 325                                 break;
 326                         case 4:
 327                                 c->designator_minimum = dval;
 328                                 break;
 329                         case 5:
 330                                 c->designator_maximum = dval;
 331                                 break;
 332                         case 7:
 333                                 c->string_index = dval;
 334                                 break;
 335                         case 8:
 336                                 c->string_minimum = dval;
 337                                 break;
 338                         case 9:
 339                                 c->string_maximum = dval;
 340                                 break;
 341                         case 10:
 342                                 c->set_delimiter = dval;
 343                                 break;
 344                         default:
 345                                 return (-4);
 346                         }
 347                         break;
 348                 default:
 349                         return (-5);
 350                 }
 351         }
 352 }
 353
 354 int
 355 hid_report_size(report_desc_t r, unsigned int id, enum hid_kind k)
 356 {
 357         struct hid_data *d;
 358         hid_item_t h;
 359         unsigned int size = 0;
 360
 361         memset(&h, 0, sizeof h);
 362         d = hid_start_parse(r, 1<<k);
 363         while (hid_get_item(d, &h)) {
 364                 if (h.report_ID == id && h.kind == k) {
 365                         unsigned int newsize = h.pos + h.report_size;
 366                         if (newsize > size)
 367                             size = newsize;
 368                 }
 369         }
 370         hid_end_parse(d);
 371
 372         if (id != NO_REPORT_ID)
 373                 size += 8;              /* add 8 bits for the report ID */
 374
 375         return ((size + 7) / 8);        /* return size in bytes */
 376 }
 377
 378 int
 379 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k, hid_item_t *h)
 380 {
 381         hid_data_t d;
 382
 383         for (d = hid_start_parse(desc, 1<<k); hid_get_item(d, h); ) {
 384                 if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
 385                         hid_end_parse(d);
 386                         return (1);
 387                 }
 388         }
 389         hid_end_parse(d);
 390         h->report_size = 0;
 391         return (0);
 392 }