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 #define ITEMTYPES 3
  47
  48 struct hid_pos_data {
  49         int32_t rid;
  50         uint32_t pos[ITEMTYPES];
  51 };
  52
  53 struct hid_data {
  54         const uint8_t *start;
  55         const uint8_t *end;
  56         const uint8_t *p;
  57         struct hid_item cur[MAXPUSH];
  58         struct hid_pos_data last_pos[MAXID];
  59         uint32_t pos[ITEMTYPES];
  60         int32_t usages_min[MAXUSAGE];
  61         int32_t usages_max[MAXUSAGE];
  62         int32_t usage_last;     /* last seen usage */
  63         uint32_t loc_size;      /* last seen size */
  64         uint32_t loc_count;     /* last seen count */
  65         uint8_t kindset;        /* we have 5 kinds so 8 bits are enough */
  66         uint8_t pushlevel;      /* current pushlevel */
  67         uint8_t ncount;         /* end usage item count */
  68         uint8_t icount;         /* current usage item count */
  69         uint8_t nusage;         /* end "usages_min/max" index */
  70         uint8_t iusage;         /* current "usages_min/max" index */
  71         uint8_t ousage;         /* current "usages_min/max" offset */
  72         uint8_t susage;         /* usage set flags */
  73 };
  74
  75 /*------------------------------------------------------------------------*
  76  *      hid_clear_local
  77  *------------------------------------------------------------------------*/
  78 static void
  79 hid_clear_local(hid_item_t *c)
  80 {
  81
  82         c->usage = 0;
  83         c->usage_minimum = 0;
  84         c->usage_maximum = 0;
  85         c->designator_index = 0;
  86         c->designator_minimum = 0;
  87         c->designator_maximum = 0;
  88         c->string_index = 0;
  89         c->string_minimum = 0;
  90         c->string_maximum = 0;
  91         c->set_delimiter = 0;
  92 }
  93
  94 static void
  95 hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
  96 {
  97         uint8_t i, j;
  98
  99         /* check for same report ID - optimise */
 100
 101         if (c->report_ID == next_rID)
 102                 return;
 103
 104         /* save current position for current rID */
 105
 106         if (c->report_ID == 0) {
 107                 i = 0;
 108         } else {
 109                 for (i = 1; i != MAXID; i++) {
 110                         if (s->last_pos[i].rid == c->report_ID)
 111                                 break;
 112                         if (s->last_pos[i].rid == 0)
 113                                 break;
 114                 }
 115         }
 116         if (i != MAXID) {
 117                 s->last_pos[i].rid = c->report_ID;
 118                 for (j = 0; j < ITEMTYPES; j++)
 119                         s->last_pos[i].pos[j] = s->pos[j];
 120         }
 121
 122         /* store next report ID */
 123
 124         c->report_ID = next_rID;
 125
 126         /* lookup last position for next rID */
 127
 128         if (next_rID == 0) {
 129                 i = 0;
 130         } else {
 131                 for (i = 1; i != MAXID; i++) {
 132                         if (s->last_pos[i].rid == next_rID)
 133                                 break;
 134                         if (s->last_pos[i].rid == 0)
 135                                 break;
 136                 }
 137         }
 138         if (i != MAXID) {
 139                 s->last_pos[i].rid = next_rID;
 140                 for (j = 0; j < ITEMTYPES; j++)
 141                         s->pos[j] = s->last_pos[i].pos[j];
 142         } else {
 143                 for (j = 0; j < ITEMTYPES; j++)
 144                         s->pos[j] = 0;  /* Out of RID entries. */
 145         }
 146 }
 147
 148 /*------------------------------------------------------------------------*
 149  *      hid_start_parse
 150  *------------------------------------------------------------------------*/
 151 hid_data_t
 152 hid_start_parse(report_desc_t d, int kindset, int id __unused)
 153 {
 154         struct hid_data *s;
 155
 156         s = malloc(sizeof *s);
 157         memset(s, 0, sizeof *s);
 158         s->start = s->p = d->data;
 159         s->end = d->data + d->size;
 160         s->kindset = kindset;
 161         return (s);
 162 }
 163
 164 /*------------------------------------------------------------------------*
 165  *      hid_end_parse
 166  *------------------------------------------------------------------------*/
 167 void
 168 hid_end_parse(hid_data_t s)
 169 {
 170
 171         if (s == NULL)
 172                 return;
 173
 174         free(s);
 175 }
 176
 177 /*------------------------------------------------------------------------*
 178  *      get byte from HID descriptor
 179  *------------------------------------------------------------------------*/
 180 static uint8_t
 181 hid_get_byte(struct hid_data *s, const uint16_t wSize)
 182 {
 183         const uint8_t *ptr;
 184         uint8_t retval;
 185
 186         ptr = s->p;
 187
 188         /* check if end is reached */
 189         if (ptr == s->end)
 190                 return (0);
 191
 192         /* read out a byte */
 193         retval = *ptr;
 194
 195         /* check if data pointer can be advanced by "wSize" bytes */
 196         if ((s->end - ptr) < wSize)
 197                 ptr = s->end;
 198         else
 199                 ptr += wSize;
 200
 201         /* update pointer */
 202         s->p = ptr;
 203
 204         return (retval);
 205 }
 206
 207 /*------------------------------------------------------------------------*
 208  *      hid_get_item
 209  *------------------------------------------------------------------------*/
 210 int
 211 hid_get_item(hid_data_t s, hid_item_t *h)
 212 {
 213         hid_item_t *c;
 214         unsigned int bTag, bType, bSize;
 215         int32_t mask;
 216         int32_t dval;
 217
 218         if (s == NULL)
 219                 return (0);
 220
 221         c = &s->cur[s->pushlevel];
 222
 223  top:
 224         /* check if there is an array of items */
 225         if (s->icount < s->ncount) {
 226                 /* get current usage */
 227                 if (s->iusage < s->nusage) {
 228                         dval = s->usages_min[s->iusage] + s->ousage;
 229                         c->usage = dval;
 230                         s->usage_last = dval;
 231                         if (dval == s->usages_max[s->iusage]) {
 232                                 s->iusage ++;
 233                                 s->ousage = 0;
 234                         } else {
 235                                 s->ousage ++;
 236                         }
 237                 } else {
 238                         /* Using last usage */
 239                         dval = s->usage_last;
 240                 }
 241                 s->icount ++;
 242                 /*
 243                  * Only copy HID item, increment position and return
 244                  * if correct kindset!
 245                  */
 246                 if (s->kindset & (1 << c->kind)) {
 247                         *h = *c;
 248                         h->pos = s->pos[c->kind];
 249                         s->pos[c->kind] += c->report_size * c->report_count;
 250                         return (1);
 251                 }
 252         }
 253
 254         /* reset state variables */
 255         s->icount = 0;
 256         s->ncount = 0;
 257         s->iusage = 0;
 258         s->nusage = 0;
 259         s->susage = 0;
 260         s->ousage = 0;
 261         hid_clear_local(c);
 262
 263         /* get next item */
 264         while (s->p != s->end) {
 265
 266                 bSize = hid_get_byte(s, 1);
 267                 if (bSize == 0xfe) {
 268                         /* long item */
 269                         bSize = hid_get_byte(s, 1);
 270                         bSize |= hid_get_byte(s, 1) << 8;
 271                         bTag = hid_get_byte(s, 1);
 272                         bType = 0xff;   /* XXX what should it be */
 273                 } else {
 274                         /* short item */
 275                         bTag = bSize >> 4;
 276                         bType = (bSize >> 2) & 3;
 277                         bSize &= 3;
 278                         if (bSize == 3)
 279                                 bSize = 4;
 280                 }
 281
 282                 switch(bSize) {
 283                 case 0:
 284                         dval = 0;
 285                         mask = 0;
 286                         break;
 287                 case 1:
 288                         dval = (int8_t)hid_get_byte(s, 1);
 289                         mask = 0xFF;
 290                         break;
 291                 case 2:
 292                         dval = hid_get_byte(s, 1);
 293                         dval |= hid_get_byte(s, 1) << 8;
 294                         dval = (int16_t)dval;
 295                         mask = 0xFFFF;
 296                         break;
 297                 case 4:
 298                         dval = hid_get_byte(s, 1);
 299                         dval |= hid_get_byte(s, 1) << 8;
 300                         dval |= hid_get_byte(s, 1) << 16;
 301                         dval |= hid_get_byte(s, 1) << 24;
 302                         mask = 0xFFFFFFFF;
 303                         break;
 304                 default:
 305                         dval = hid_get_byte(s, bSize);
 306                         continue;
 307                 }
 308
 309                 switch (bType) {
 310                 case 0:         /* Main */
 311                         switch (bTag) {
 312                         case 8: /* Input */
 313                                 c->kind = hid_input;
 314                                 c->flags = dval;
 315                 ret:
 316                                 c->report_count = s->loc_count;
 317                                 c->report_size = s->loc_size;
 318
 319                                 if (c->flags & HIO_VARIABLE) {
 320                                         /* range check usage count */
 321                                         if (c->report_count > 255) {
 322                                                 s->ncount = 255;
 323                                         } else
 324                                                 s->ncount = c->report_count;
 325
 326                                         /*
 327                                          * The "top" loop will return
 328                                          * one and one item:
 329                                          */
 330                                         c->report_count = 1;
 331                                         c->usage_minimum = 0;
 332                                         c->usage_maximum = 0;
 333                                 } else {
 334                                         s->ncount = 1;
 335                                 }
 336                                 goto top;
 337
 338                         case 9: /* Output */
 339                                 c->kind = hid_output;
 340                                 c->flags = dval;
 341                                 goto ret;
 342                         case 10:        /* Collection */
 343                                 c->kind = hid_collection;
 344                                 c->collection = dval;
 345                                 c->collevel++;
 346                                 c->usage = s->usage_last;
 347                                 *h = *c;
 348                                 return (1);
 349                         case 11:        /* Feature */
 350                                 c->kind = hid_feature;
 351                                 c->flags = dval;
 352                                 goto ret;
 353                         case 12:        /* End collection */
 354                                 c->kind = hid_endcollection;
 355                                 if (c->collevel == 0) {
 356                                         /* Invalid end collection. */
 357                                         return (0);
 358                                 }
 359                                 c->collevel--;
 360                                 *h = *c;
 361                                 return (1);
 362                         default:
 363                                 break;
 364                         }
 365                         break;
 366
 367                 case 1:         /* Global */
 368                         switch (bTag) {
 369                         case 0:
 370                                 c->_usage_page = dval << 16;
 371                                 break;
 372                         case 1:
 373                                 c->logical_minimum = dval;
 374                                 break;
 375                         case 2:
 376                                 c->logical_maximum = dval;
 377                                 break;
 378                         case 3:
 379                                 c->physical_minimum = dval;
 380                                 break;
 381                         case 4:
 382                                 c->physical_maximum = dval;
 383                                 break;
 384                         case 5:
 385                                 c->unit_exponent = dval;
 386                                 break;
 387                         case 6:
 388                                 c->unit = dval;
 389                                 break;
 390                         case 7:
 391                                 /* mask because value is unsigned */
 392                                 s->loc_size = dval & mask;
 393                                 break;
 394                         case 8:
 395                                 hid_switch_rid(s, c, dval & mask);
 396                                 break;
 397                         case 9:
 398                                 /* mask because value is unsigned */
 399                                 s->loc_count = dval & mask;
 400                                 break;
 401                         case 10:        /* Push */
 402                                 s->pushlevel ++;
 403                                 if (s->pushlevel < MAXPUSH) {
 404                                         s->cur[s->pushlevel] = *c;
 405                                         /* store size and count */
 406                                         c->report_size = s->loc_size;
 407                                         c->report_count = s->loc_count;
 408                                         /* update current item pointer */
 409                                         c = &s->cur[s->pushlevel];
 410                                 }
 411                                 break;
 412                         case 11:        /* Pop */
 413                                 s->pushlevel --;
 414                                 if (s->pushlevel < MAXPUSH) {
 415                                         c = &s->cur[s->pushlevel];
 416                                         /* restore size and count */
 417                                         s->loc_size = c->report_size;
 418                                         s->loc_count = c->report_count;
 419                                         c->report_size = 0;
 420                                         c->report_count = 0;
 421                                 }
 422                                 break;
 423                         default:
 424                                 break;
 425                         }
 426                         break;
 427                 case 2:         /* Local */
 428                         switch (bTag) {
 429                         case 0:
 430                                 if (bSize != 4)
 431                                         dval = (dval & mask) | c->_usage_page;
 432
 433                                 /* set last usage, in case of a collection */
 434                                 s->usage_last = dval;
 435
 436                                 if (s->nusage < MAXUSAGE) {
 437                                         s->usages_min[s->nusage] = dval;
 438                                         s->usages_max[s->nusage] = dval;
 439                                         s->nusage ++;
 440                                 }
 441                                 /* else XXX */
 442
 443                                 /* clear any pending usage sets */
 444                                 s->susage = 0;
 445                                 break;
 446                         case 1:
 447                                 s->susage |= 1;
 448
 449                                 if (bSize != 4)
 450                                         dval = (dval & mask) | c->_usage_page;
 451                                 c->usage_minimum = dval;
 452
 453                                 goto check_set;
 454                         case 2:
 455                                 s->susage |= 2;
 456
 457                                 if (bSize != 4)
 458                                         dval = (dval & mask) | c->_usage_page;
 459                                 c->usage_maximum = dval;
 460
 461                         check_set:
 462                                 if (s->susage != 3)
 463                                         break;
 464
 465                                 /* sanity check */
 466                                 if ((s->nusage < MAXUSAGE) &&
 467                                     (c->usage_minimum <= c->usage_maximum)) {
 468                                         /* add usage range */
 469                                         s->usages_min[s->nusage] =
 470                                             c->usage_minimum;
 471                                         s->usages_max[s->nusage] =
 472                                             c->usage_maximum;
 473                                         s->nusage ++;
 474                                 }
 475                                 /* else XXX */
 476
 477                                 s->susage = 0;
 478                                 break;
 479                         case 3:
 480                                 c->designator_index = dval;
 481                                 break;
 482                         case 4:
 483                                 c->designator_minimum = dval;
 484                                 break;
 485                         case 5:
 486                                 c->designator_maximum = dval;
 487                                 break;
 488                         case 7:
 489                                 c->string_index = dval;
 490                                 break;
 491                         case 8:
 492                                 c->string_minimum = dval;
 493                                 break;
 494                         case 9:
 495                                 c->string_maximum = dval;
 496                                 break;
 497                         case 10:
 498                                 c->set_delimiter = dval;
 499                                 break;
 500                         default:
 501                                 break;
 502                         }
 503                         break;
 504                 default:
 505                         break;
 506                 }
 507         }
 508         return (0);
 509 }
 510
 511 int
 512 hid_report_size(report_desc_t r, enum hid_kind k, int id)
 513 {
 514         struct hid_data *d;
 515         struct hid_item h;
 516         uint32_t temp;
 517         uint32_t hpos;
 518         uint32_t lpos;
 519         int report_id = 0;
 520
 521         hpos = 0;
 522         lpos = 0xFFFFFFFF;
 523
 524         memset(&h, 0, sizeof h);
 525         for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) {
 526                 if ((h.report_ID == id || id < 0) && h.kind == k) {
 527                         /* compute minimum */
 528                         if (lpos > h.pos)
 529                                 lpos = h.pos;
 530                         /* compute end position */
 531                         temp = h.pos + (h.report_size * h.report_count);
 532                         /* compute maximum */
 533                         if (hpos < temp)
 534                                 hpos = temp;
 535                         if (h.report_ID != 0)
 536                                 report_id = 1;
 537                 }
 538         }
 539         hid_end_parse(d);
 540
 541         /* safety check - can happen in case of currupt descriptors */
 542         if (lpos > hpos)
 543                 temp = 0;
 544         else
 545                 temp = hpos - lpos;
 546
 547         /* return length in bytes rounded up */
 548         return ((temp + 7) / 8 + report_id);
 549 }
 550
 551 int
 552 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
 553            hid_item_t *h, int id)
 554 {
 555         struct hid_data *d;
 556
 557         for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) {
 558                 if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
 559                         hid_end_parse(d);
 560                         return (1);
 561                 }
 562         }
 563         hid_end_parse(d);
 564         h->report_size = 0;
 565         return (0);
 566 }