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, 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  * $FreeBSD: src/lib/libusbhid/parse.c,v 1.10 2004/02/11 21:09:13 emax Exp $
  29  * $DragonFly: src/lib/libusbhid/parse.c,v 1.4 2008/11/24 17:15:17 hasso 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 "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 }