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
  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 #define MAXPUSH 4
  45 #define MAXID 64
  46
  47 struct hid_pos_data {
  48         int32_t rid;
  49         uint32_t pos;
  50 };
  51
  52 struct hid_data {
  53         const uint8_t *start;
  54         const uint8_t *end;
  55         const uint8_t *p;
  56         struct hid_item cur[MAXPUSH];
  57         struct hid_pos_data last_pos[MAXID];
  58         int32_t usages_min[MAXUSAGE];
  59         int32_t usages_max[MAXUSAGE];
  60         int32_t usage_last;     /* last seen usage */
  61         uint32_t loc_size;      /* last seen size */
  62         uint32_t loc_count;     /* last seen count */
  63         uint8_t kindset;        /* we have 5 kinds so 8 bits are enough */
  64         uint8_t pushlevel;      /* current pushlevel */
  65         uint8_t ncount;         /* end usage item count */
  66         uint8_t icount;         /* current usage item count */
  67         uint8_t nusage;         /* end "usages_min/max" index */
  68         uint8_t iusage;         /* current "usages_min/max" index */
  69         uint8_t ousage;         /* current "usages_min/max" offset */
  70         uint8_t susage;         /* usage set flags */
  71 };
  72
  73 /*------------------------------------------------------------------------*
  74  *      hid_clear_local
  75  *------------------------------------------------------------------------*/
  76 static void
  77 hid_clear_local(hid_item_t *c)
  78 {
  79
  80         c->usage = 0;
  81         c->usage_minimum = 0;
  82         c->usage_maximum = 0;
  83         c->designator_index = 0;
  84         c->designator_minimum = 0;
  85         c->designator_maximum = 0;
  86         c->string_index = 0;
  87         c->string_minimum = 0;
  88         c->string_maximum = 0;
  89         c->set_delimiter = 0;
  90 }
  91
  92 static void
  93 hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
  94 {
  95         uint8_t i;
  96
  97         /* check for same report ID - optimise */
  98
  99         if (c->report_ID == next_rID)
 100                 return;
 101
 102         /* save current position for current rID */
 103
 104         if (c->report_ID == 0) {
 105                 i = 0;
 106         } else {
 107                 for (i = 1; i != MAXID; i++) {
 108                         if (s->last_pos[i].rid == c->report_ID)
 109                                 break;
 110                         if (s->last_pos[i].rid == 0)
 111                                 break;
 112                 }
 113         }
 114         if (i != MAXID) {
 115                 s->last_pos[i].rid = c->report_ID;
 116                 s->last_pos[i].pos = c->pos;
 117         }
 118
 119         /* store next report ID */
 120
 121         c->report_ID = next_rID;
 122
 123         /* lookup last position for next rID */
 124
 125         if (next_rID == 0) {
 126                 i = 0;
 127         } else {
 128                 for (i = 1; i != MAXID; i++) {
 129                         if (s->last_pos[i].rid == next_rID)
 130                                 break;
 131                         if (s->last_pos[i].rid == 0)
 132                                 break;
 133                 }
 134         }
 135         if (i != MAXID) {
 136                 s->last_pos[i].rid = next_rID;
 137                 c->pos = s->last_pos[i].pos;
 138         } else
 139                 c->pos = 0;     /* Out of RID entries. */
 140 }
 141
 142 /*------------------------------------------------------------------------*
 143  *      hid_start_parse
 144  *------------------------------------------------------------------------*/
 145 hid_data_t
 146 hid_start_parse(report_desc_t d, int kindset, int id __unused)
 147 {
 148         struct hid_data *s;
 149
 150         s = malloc(sizeof *s);
 151         memset(s, 0, sizeof *s);
 152         s->start = s->p = d->data;
 153         s->end = d->data + d->size;
 154         s->kindset = kindset;
 155         return (s);
 156 }
 157
 158 /*------------------------------------------------------------------------*
 159  *      hid_end_parse
 160  *------------------------------------------------------------------------*/
 161 void
 162 hid_end_parse(hid_data_t s)
 163 {
 164
 165         if (s == NULL)
 166                 return;
 167
 168         free(s);
 169 }
 170
 171 /*------------------------------------------------------------------------*
 172  *      get byte from HID descriptor
 173  *------------------------------------------------------------------------*/
 174 static uint8_t
 175 hid_get_byte(struct hid_data *s, const uint16_t wSize)
 176 {
 177         const uint8_t *ptr;
 178         uint8_t retval;
 179
 180         ptr = s->p;
 181
 182         /* check if end is reached */
 183         if (ptr == s->end)
 184                 return (0);
 185
 186         /* read out a byte */
 187         retval = *ptr;
 188
 189         /* check if data pointer can be advanced by "wSize" bytes */
 190         if ((s->end - ptr) < wSize)
 191                 ptr = s->end;
 192         else
 193                 ptr += wSize;
 194
 195         /* update pointer */
 196         s->p = ptr;
 197
 198         return (retval);
 199 }
 200
 201 /*------------------------------------------------------------------------*
 202  *      hid_get_item
 203  *------------------------------------------------------------------------*/
 204 int
 205 hid_get_item(hid_data_t s, hid_item_t *h)
 206 {
 207         hid_item_t *c;
 208         unsigned int bTag, bType, bSize;
 209         uint32_t oldpos;
 210         int32_t mask;
 211         int32_t dval;
 212
 213         if (s == NULL)
 214                 return (0);
 215
 216         c = &s->cur[s->pushlevel];
 217
 218  top:
 219         /* check if there is an array of items */
 220         if (s->icount < s->ncount) {
 221                 /* get current usage */
 222                 if (s->iusage < s->nusage) {
 223                         dval = s->usages_min[s->iusage] + s->ousage;
 224                         c->usage = dval;
 225                         s->usage_last = dval;
 226                         if (dval == s->usages_max[s->iusage]) {
 227                                 s->iusage ++;
 228                                 s->ousage = 0;
 229                         } else {
 230                                 s->ousage ++;
 231                         }
 232                 } else {
 233                         /* Using last usage */
 234                         dval = s->usage_last;
 235                 }
 236                 s->icount ++;
 237                 /*
 238                  * Only copy HID item, increment position and return
 239                  * if correct kindset!
 240                  */
 241                 if (s->kindset & (1 << c->kind)) {
 242                         *h = *c;
 243                         c->pos += c->report_size * c->report_count;
 244                         return (1);
 245                 }
 246         }
 247
 248         /* reset state variables */
 249         s->icount = 0;
 250         s->ncount = 0;
 251         s->iusage = 0;
 252         s->nusage = 0;
 253         s->susage = 0;
 254         s->ousage = 0;
 255         hid_clear_local(c);
 256
 257         /* get next item */
 258         while (s->p != s->end) {
 259
 260                 bSize = hid_get_byte(s, 1);
 261                 if (bSize == 0xfe) {
 262                         /* long item */
 263                         bSize = hid_get_byte(s, 1);
 264                         bSize |= hid_get_byte(s, 1) << 8;
 265                         bTag = hid_get_byte(s, 1);
 266                         bType = 0xff;   /* XXX what should it be */
 267                 } else {
 268                         /* short item */
 269                         bTag = bSize >> 4;
 270                         bType = (bSize >> 2) & 3;
 271                         bSize &= 3;
 272                         if (bSize == 3)
 273                                 bSize = 4;
 274                 }
 275
 276                 switch(bSize) {
 277                 case 0:
 278                         dval = 0;
 279                         mask = 0;
 280                         break;
 281                 case 1:
 282                         dval = (int8_t)hid_get_byte(s, 1);
 283                         mask = 0xFF;
 284                         break;
 285                 case 2:
 286                         dval = hid_get_byte(s, 1);
 287                         dval |= hid_get_byte(s, 1) << 8;
 288                         dval = (int16_t)dval;
 289                         mask = 0xFFFF;
 290                         break;
 291                 case 4:
 292                         dval = hid_get_byte(s, 1);
 293                         dval |= hid_get_byte(s, 1) << 8;
 294                         dval |= hid_get_byte(s, 1) << 16;
 295                         dval |= hid_get_byte(s, 1) << 24;
 296                         mask = 0xFFFFFFFF;
 297                         break;
 298                 default:
 299                         dval = hid_get_byte(s, bSize);
 300                         continue;
 301                 }
 302
 303                 switch (bType) {
 304                 case 0:         /* Main */
 305                         switch (bTag) {
 306                         case 8: /* Input */
 307                                 c->kind = hid_input;
 308                                 c->flags = dval;
 309                 ret:
 310                                 c->report_count = s->loc_count;
 311                                 c->report_size = s->loc_size;
 312
 313                                 if (c->flags & HIO_VARIABLE) {
 314                                         /* range check usage count */
 315                                         if (c->report_count > 255) {
 316                                                 s->ncount = 255;
 317                                         } else
 318                                                 s->ncount = c->report_count;
 319
 320                                         /*
 321                                          * The "top" loop will return
 322                                          * one and one item:
 323                                          */
 324                                         c->report_count = 1;
 325                                 } else {
 326                                         s->ncount = 1;
 327                                 }
 328                                 goto top;
 329
 330                         case 9: /* Output */
 331                                 c->kind = hid_output;
 332                                 c->flags = dval;
 333                                 goto ret;
 334                         case 10:        /* Collection */
 335                                 c->kind = hid_collection;
 336                                 c->collection = dval;
 337                                 c->collevel++;
 338                                 c->usage = s->usage_last;
 339                                 *h = *c;
 340                                 return (1);
 341                         case 11:        /* Feature */
 342                                 c->kind = hid_feature;
 343                                 c->flags = dval;
 344                                 goto ret;
 345                         case 12:        /* End collection */
 346                                 c->kind = hid_endcollection;
 347                                 if (c->collevel == 0) {
 348                                         /* Invalid end collection. */
 349                                         return (0);
 350                                 }
 351                                 c->collevel--;
 352                                 *h = *c;
 353                                 return (1);
 354                         default:
 355                                 break;
 356                         }
 357                         break;
 358
 359                 case 1:         /* Global */
 360                         switch (bTag) {
 361                         case 0:
 362                                 c->_usage_page = dval << 16;
 363                                 break;
 364                         case 1:
 365                                 c->logical_minimum = dval;
 366                                 break;
 367                         case 2:
 368                                 c->logical_maximum = dval;
 369                                 break;
 370                         case 3:
 371                                 c->physical_minimum = dval;
 372                                 break;
 373                         case 4:
 374                                 c->physical_maximum = dval;
 375                                 break;
 376                         case 5:
 377                                 c->unit_exponent = dval;
 378                                 break;
 379                         case 6:
 380                                 c->unit = dval;
 381                                 break;
 382                         case 7:
 383                                 /* mask because value is unsigned */
 384                                 s->loc_size = dval & mask;
 385                                 break;
 386                         case 8:
 387                                 hid_switch_rid(s, c, dval);
 388                                 break;
 389                         case 9:
 390                                 /* mask because value is unsigned */
 391                                 s->loc_count = dval & mask;
 392                                 break;
 393                         case 10:        /* Push */
 394                                 s->pushlevel ++;
 395                                 if (s->pushlevel < MAXPUSH) {
 396                                         s->cur[s->pushlevel] = *c;
 397                                         /* store size and count */
 398                                         c->report_size = s->loc_size;
 399                                         c->report_count = s->loc_count;
 400                                         /* update current item pointer */
 401                                         c = &s->cur[s->pushlevel];
 402                                 }
 403                                 break;
 404                         case 11:        /* Pop */
 405                                 s->pushlevel --;
 406                                 if (s->pushlevel < MAXPUSH) {
 407                                         /* preserve position */
 408                                         oldpos = c->pos;
 409                                         c = &s->cur[s->pushlevel];
 410                                         /* restore size and count */
 411                                         s->loc_size = c->report_size;
 412                                         s->loc_count = c->report_count;
 413                                         /* set default item location */
 414                                         c->pos = oldpos;
 415                                         c->report_size = 0;
 416                                         c->report_count = 0;
 417                                 }
 418                                 break;
 419                         default:
 420                                 break;
 421                         }
 422                         break;
 423                 case 2:         /* Local */
 424                         switch (bTag) {
 425                         case 0:
 426                                 if (bSize != 4)
 427                                         dval = (dval & mask) | c->_usage_page;
 428
 429                                 /* set last usage, in case of a collection */
 430                                 s->usage_last = dval;
 431
 432                                 if (s->nusage < MAXUSAGE) {
 433                                         s->usages_min[s->nusage] = dval;
 434                                         s->usages_max[s->nusage] = dval;
 435                                         s->nusage ++;
 436                                 }
 437                                 /* else XXX */
 438
 439                                 /* clear any pending usage sets */
 440                                 s->susage = 0;
 441                                 break;
 442                         case 1:
 443                                 s->susage |= 1;
 444
 445                                 if (bSize != 4)
 446                                         dval = (dval & mask) | c->_usage_page;
 447                                 c->usage_minimum = dval;
 448
 449                                 goto check_set;
 450                         case 2:
 451                                 s->susage |= 2;
 452
 453                                 if (bSize != 4)
 454                                         dval = (dval & mask) | c->_usage_page;
 455                                 c->usage_maximum = dval;
 456
 457                         check_set:
 458                                 if (s->susage != 3)
 459                                         break;
 460
 461                                 /* sanity check */
 462                                 if ((s->nusage < MAXUSAGE) &&
 463                                     (c->usage_minimum <= c->usage_maximum)) {
 464                                         /* add usage range */
 465                                         s->usages_min[s->nusage] =
 466                                             c->usage_minimum;
 467                                         s->usages_max[s->nusage] =
 468                                             c->usage_maximum;
 469                                         s->nusage ++;
 470                                 }
 471                                 /* else XXX */
 472
 473                                 s->susage = 0;
 474                                 break;
 475                         case 3:
 476                                 c->designator_index = dval;
 477                                 break;
 478                         case 4:
 479                                 c->designator_minimum = dval;
 480                                 break;
 481                         case 5:
 482                                 c->designator_maximum = dval;
 483                                 break;
 484                         case 7:
 485                                 c->string_index = dval;
 486                                 break;
 487                         case 8:
 488                                 c->string_minimum = dval;
 489                                 break;
 490                         case 9:
 491                                 c->string_maximum = dval;
 492                                 break;
 493                         case 10:
 494                                 c->set_delimiter = dval;
 495                                 break;
 496                         default:
 497                                 break;
 498                         }
 499                         break;
 500                 default:
 501                         break;
 502                 }
 503         }
 504         return (0);
 505 }
 506
 507 int
 508 hid_report_size(report_desc_t r, enum hid_kind k, int id)
 509 {
 510         struct hid_data *d;
 511         struct hid_item h;
 512         uint32_t temp;
 513         uint32_t hpos;
 514         uint32_t lpos;
 515
 516         hpos = 0;
 517         lpos = 0xFFFFFFFF;
 518
 519         memset(&h, 0, sizeof h);
 520         for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) {
 521                 if (h.report_ID == id && h.kind == k) {
 522                         /* compute minimum */
 523                         if (lpos > h.pos)
 524                                 lpos = h.pos;
 525                         /* compute end position */
 526                         temp = h.pos + (h.report_size * h.report_count);
 527                         /* compute maximum */
 528                         if (hpos < temp)
 529                                 hpos = temp;
 530                 }
 531         }
 532         hid_end_parse(d);
 533
 534         /* safety check - can happen in case of currupt descriptors */
 535         if (lpos > hpos)
 536                 temp = 0;
 537         else
 538                 temp = hpos - lpos;
 539
 540         if (id)
 541                 temp += 8;
 542
 543         /* return length in bytes rounded up */
 544         return ((temp + 7) / 8);
 545 }
 546
 547 int
 548 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
 549            hid_item_t *h, int id)
 550 {
 551         struct hid_data *d;
 552
 553         for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) {
 554                 if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
 555                         hid_end_parse(d);
 556                         return (1);
 557                 }
 558         }
 559         hid_end_parse(d);
 560         h->report_size = 0;
 561         return (0);
 562 }