lib/libusbhid/parse.c

   1 /*      $NetBSD: parse.c,v 1.11 2000/09/24 02:19:54 augustss Exp $      */
   2
   3 /*-
   4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
   5  *
   6  * Copyright (c) 1999, 2001 Lennart Augustsson <augustss@netbsd.org>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <assert.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <sys/time.h>
  38
  39 #include <dev/usb/usb.h>
  40 #include <dev/usb/usbhid.h>
  41
  42 #include "usbhid.h"
  43 #include "usbvar.h"
  44
  45 #define MAXUSAGE 100
  46 #define MAXPUSH 4
  47 #define MAXID 64
  48 #define ITEMTYPES 3
  49
  50 struct hid_pos_data {
  51         int32_t rid;
  52         uint32_t pos[ITEMTYPES];
  53 };
  54
  55 struct hid_data {
  56         const uint8_t *start;
  57         const uint8_t *end;
  58         const uint8_t *p;
  59         struct hid_item cur[MAXPUSH];
  60         struct hid_pos_data last_pos[MAXID];
  61         uint32_t pos[ITEMTYPES];
  62         int32_t usages_min[MAXUSAGE];
  63         int32_t usages_max[MAXUSAGE];
  64         int32_t usage_last;     /* last seen usage */
  65         uint32_t loc_size;      /* last seen size */
  66         uint32_t loc_count;     /* last seen count */
  67         uint8_t kindset;        /* we have 5 kinds so 8 bits are enough */
  68         uint8_t pushlevel;      /* current pushlevel */
  69         uint8_t ncount;         /* end usage item count */
  70         uint8_t icount;         /* current usage item count */
  71         uint8_t nusage;         /* end "usages_min/max" index */
  72         uint8_t iusage;         /* current "usages_min/max" index */
  73         uint8_t ousage;         /* current "usages_min/max" offset */
  74         uint8_t susage;         /* usage set flags */
  75         int32_t reportid;       /* requested report ID */
  76 };
  77
  78 /*------------------------------------------------------------------------*
  79  *      hid_clear_local
  80  *------------------------------------------------------------------------*/
  81 static void
  82 hid_clear_local(hid_item_t *c)
  83 {
  84
  85         c->usage = 0;
  86         c->usage_minimum = 0;
  87         c->usage_maximum = 0;
  88         c->designator_index = 0;
  89         c->designator_minimum = 0;
  90         c->designator_maximum = 0;
  91         c->string_index = 0;
  92         c->string_minimum = 0;
  93         c->string_maximum = 0;
  94         c->set_delimiter = 0;
  95 }
  96
  97 static void
  98 hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
  99 {
 100         uint8_t i, j;
 101
 102         /* check for same report ID - optimise */
 103
 104         if (c->report_ID == next_rID)
 105                 return;
 106
 107         /* save current position for current rID */
 108
 109         if (c->report_ID == 0) {
 110                 i = 0;
 111         } else {
 112                 for (i = 1; i != MAXID; i++) {
 113                         if (s->last_pos[i].rid == c->report_ID)
 114                                 break;
 115                         if (s->last_pos[i].rid == 0)
 116                                 break;
 117                 }
 118         }
 119         if (i != MAXID) {
 120                 s->last_pos[i].rid = c->report_ID;
 121                 for (j = 0; j < ITEMTYPES; j++)
 122                         s->last_pos[i].pos[j] = s->pos[j];
 123         }
 124
 125         /* store next report ID */
 126
 127         c->report_ID = next_rID;
 128
 129         /* lookup last position for next rID */
 130
 131         if (next_rID == 0) {
 132                 i = 0;
 133         } else {
 134                 for (i = 1; i != MAXID; i++) {
 135                         if (s->last_pos[i].rid == next_rID)
 136                                 break;
 137                         if (s->last_pos[i].rid == 0)
 138                                 break;
 139                 }
 140         }
 141         if (i != MAXID) {
 142                 s->last_pos[i].rid = next_rID;
 143                 for (j = 0; j < ITEMTYPES; j++)
 144                         s->pos[j] = s->last_pos[i].pos[j];
 145         } else {
 146                 for (j = 0; j < ITEMTYPES; j++)
 147                         s->pos[j] = 0;  /* Out of RID entries. */
 148         }
 149 }
 150
 151 /*------------------------------------------------------------------------*
 152  *      hid_start_parse
 153  *------------------------------------------------------------------------*/
 154 hid_data_t
 155 hid_start_parse(report_desc_t d, int kindset, int id)
 156 {
 157         struct hid_data *s;
 158
 159         s = malloc(sizeof *s);
 160         memset(s, 0, sizeof *s);
 161         s->start = s->p = d->data;
 162         s->end = d->data + d->size;
 163         s->kindset = kindset;
 164         s->reportid = id;
 165         return (s);
 166 }
 167
 168 /*------------------------------------------------------------------------*
 169  *      hid_end_parse
 170  *------------------------------------------------------------------------*/
 171 void
 172 hid_end_parse(hid_data_t s)
 173 {
 174
 175         if (s == NULL)
 176                 return;
 177
 178         free(s);
 179 }
 180
 181 /*------------------------------------------------------------------------*
 182  *      get byte from HID descriptor
 183  *------------------------------------------------------------------------*/
 184 static uint8_t
 185 hid_get_byte(struct hid_data *s, const uint16_t wSize)
 186 {
 187         const uint8_t *ptr;
 188         uint8_t retval;
 189
 190         ptr = s->p;
 191
 192         /* check if end is reached */
 193         if (ptr == s->end)
 194                 return (0);
 195
 196         /* read out a byte */
 197         retval = *ptr;
 198
 199         /* check if data pointer can be advanced by "wSize" bytes */
 200         if ((s->end - ptr) < wSize)
 201                 ptr = s->end;
 202         else
 203                 ptr += wSize;
 204
 205         /* update pointer */
 206         s->p = ptr;
 207
 208         return (retval);
 209 }
 210
 211 /*------------------------------------------------------------------------*
 212  *      hid_get_item
 213  *------------------------------------------------------------------------*/
 214 static int
 215 hid_get_item_raw(hid_data_t s, hid_item_t *h)
 216 {
 217         hid_item_t *c;
 218         unsigned int bTag, bType, bSize;
 219         int32_t mask;
 220         int32_t dval;
 221
 222         if (s == NULL)
 223                 return (0);
 224
 225         c = &s->cur[s->pushlevel];
 226
 227  top:
 228         /* check if there is an array of items */
 229         if (s->icount < s->ncount) {
 230                 /* get current usage */
 231                 if (s->iusage < s->nusage) {
 232                         dval = s->usages_min[s->iusage] + s->ousage;
 233                         c->usage = dval;
 234                         s->usage_last = dval;
 235                         if (dval == s->usages_max[s->iusage]) {
 236                                 s->iusage ++;
 237                                 s->ousage = 0;
 238                         } else {
 239                                 s->ousage ++;
 240                         }
 241                 } else {
 242                         /* Using last usage */
 243                         dval = s->usage_last;
 244                 }
 245                 s->icount ++;
 246                 /*
 247                  * Only copy HID item, increment position and return
 248                  * if correct kindset!
 249                  */
 250                 if (s->kindset & (1 << c->kind)) {
 251                         *h = *c;
 252                         h->pos = s->pos[c->kind];
 253                         s->pos[c->kind] += c->report_size * c->report_count;
 254                         return (1);
 255                 }
 256         }
 257
 258         /* reset state variables */
 259         s->icount = 0;
 260         s->ncount = 0;
 261         s->iusage = 0;
 262         s->nusage = 0;
 263         s->susage = 0;
 264         s->ousage = 0;
 265         hid_clear_local(c);
 266
 267         /* get next item */
 268         while (s->p != s->end) {
 269
 270                 bSize = hid_get_byte(s, 1);
 271                 if (bSize == 0xfe) {
 272                         /* long item */
 273                         bSize = hid_get_byte(s, 1);
 274                         bSize |= hid_get_byte(s, 1) << 8;
 275                         bTag = hid_get_byte(s, 1);
 276                         bType = 0xff;   /* XXX what should it be */
 277                 } else {
 278                         /* short item */
 279                         bTag = bSize >> 4;
 280                         bType = (bSize >> 2) & 3;
 281                         bSize &= 3;
 282                         if (bSize == 3)
 283                                 bSize = 4;
 284                 }
 285
 286                 switch(bSize) {
 287                 case 0:
 288                         dval = 0;
 289                         mask = 0;
 290                         break;
 291                 case 1:
 292                         dval = (int8_t)hid_get_byte(s, 1);
 293                         mask = 0xFF;
 294                         break;
 295                 case 2:
 296                         dval = hid_get_byte(s, 1);
 297                         dval |= hid_get_byte(s, 1) << 8;
 298                         dval = (int16_t)dval;
 299                         mask = 0xFFFF;
 300                         break;
 301                 case 4:
 302                         dval = hid_get_byte(s, 1);
 303                         dval |= hid_get_byte(s, 1) << 8;
 304                         dval |= hid_get_byte(s, 1) << 16;
 305                         dval |= hid_get_byte(s, 1) << 24;
 306                         mask = 0xFFFFFFFF;
 307                         break;
 308                 default:
 309                         dval = hid_get_byte(s, bSize);
 310                         continue;
 311                 }
 312
 313                 switch (bType) {
 314                 case 0:         /* Main */
 315                         switch (bTag) {
 316                         case 8: /* Input */
 317                                 c->kind = hid_input;
 318                                 c->flags = dval;
 319                 ret:
 320                                 c->report_count = s->loc_count;
 321                                 c->report_size = s->loc_size;
 322
 323                                 if (c->flags & HIO_VARIABLE) {
 324                                         /* range check usage count */
 325                                         if (c->report_count > 255) {
 326                                                 s->ncount = 255;
 327                                         } else
 328                                                 s->ncount = c->report_count;
 329
 330                                         /*
 331                                          * The "top" loop will return
 332                                          * one and one item:
 333                                          */
 334                                         c->report_count = 1;
 335                                         c->usage_minimum = 0;
 336                                         c->usage_maximum = 0;
 337                                 } else {
 338                                         s->ncount = 1;
 339                                 }
 340                                 goto top;
 341
 342                         case 9: /* Output */
 343                                 c->kind = hid_output;
 344                                 c->flags = dval;
 345                                 goto ret;
 346                         case 10:        /* Collection */
 347                                 c->kind = hid_collection;
 348                                 c->collection = dval;
 349                                 c->collevel++;
 350                                 c->usage = s->usage_last;
 351                                 *h = *c;
 352                                 return (1);
 353                         case 11:        /* Feature */
 354                                 c->kind = hid_feature;
 355                                 c->flags = dval;
 356                                 goto ret;
 357                         case 12:        /* End collection */
 358                                 c->kind = hid_endcollection;
 359                                 if (c->collevel == 0) {
 360                                         /* Invalid end collection. */
 361                                         return (0);
 362                                 }
 363                                 c->collevel--;
 364                                 *h = *c;
 365                                 return (1);
 366                         default:
 367                                 break;
 368                         }
 369                         break;
 370
 371                 case 1:         /* Global */
 372                         switch (bTag) {
 373                         case 0:
 374                                 c->_usage_page = dval << 16;
 375                                 break;
 376                         case 1:
 377                                 c->logical_minimum = dval;
 378                                 break;
 379                         case 2:
 380                                 c->logical_maximum = dval;
 381                                 break;
 382                         case 3:
 383                                 c->physical_minimum = dval;
 384                                 break;
 385                         case 4:
 386                                 c->physical_maximum = dval;
 387                                 break;
 388                         case 5:
 389                                 c->unit_exponent = dval;
 390                                 break;
 391                         case 6:
 392                                 c->unit = dval;
 393                                 break;
 394                         case 7:
 395                                 /* mask because value is unsigned */
 396                                 s->loc_size = dval & mask;
 397                                 break;
 398                         case 8:
 399                                 hid_switch_rid(s, c, dval & mask);
 400                                 break;
 401                         case 9:
 402                                 /* mask because value is unsigned */
 403                                 s->loc_count = dval & mask;
 404                                 break;
 405                         case 10:        /* Push */
 406                                 /* stop parsing, if invalid push level */
 407                                 if ((s->pushlevel + 1) >= MAXPUSH)
 408                                         return (0);
 409                                 s->pushlevel ++;
 410                                 s->cur[s->pushlevel] = *c;
 411                                 /* store size and count */
 412                                 c->report_size = s->loc_size;
 413                                 c->report_count = s->loc_count;
 414                                 /* update current item pointer */
 415                                 c = &s->cur[s->pushlevel];
 416                                 break;
 417                         case 11:        /* Pop */
 418                                 /* stop parsing, if invalid push level */
 419                                 if (s->pushlevel == 0)
 420                                         return (0);
 421                                 s->pushlevel --;
 422                                 c = &s->cur[s->pushlevel];
 423                                 /* restore size and count */
 424                                 s->loc_size = c->report_size;
 425                                 s->loc_count = c->report_count;
 426                                 c->report_size = 0;
 427                                 c->report_count = 0;
 428                                 break;
 429                         default:
 430                                 break;
 431                         }
 432                         break;
 433                 case 2:         /* Local */
 434                         switch (bTag) {
 435                         case 0:
 436                                 if (bSize != 4)
 437                                         dval = (dval & mask) | c->_usage_page;
 438
 439                                 /* set last usage, in case of a collection */
 440                                 s->usage_last = dval;
 441
 442                                 if (s->nusage < MAXUSAGE) {
 443                                         s->usages_min[s->nusage] = dval;
 444                                         s->usages_max[s->nusage] = dval;
 445                                         s->nusage ++;
 446                                 }
 447                                 /* else XXX */
 448
 449                                 /* clear any pending usage sets */
 450                                 s->susage = 0;
 451                                 break;
 452                         case 1:
 453                                 s->susage |= 1;
 454
 455                                 if (bSize != 4)
 456                                         dval = (dval & mask) | c->_usage_page;
 457                                 c->usage_minimum = dval;
 458
 459                                 goto check_set;
 460                         case 2:
 461                                 s->susage |= 2;
 462
 463                                 if (bSize != 4)
 464                                         dval = (dval & mask) | c->_usage_page;
 465                                 c->usage_maximum = dval;
 466
 467                         check_set:
 468                                 if (s->susage != 3)
 469                                         break;
 470
 471                                 /* sanity check */
 472                                 if ((s->nusage < MAXUSAGE) &&
 473                                     (c->usage_minimum <= c->usage_maximum)) {
 474                                         /* add usage range */
 475                                         s->usages_min[s->nusage] =
 476                                             c->usage_minimum;
 477                                         s->usages_max[s->nusage] =
 478                                             c->usage_maximum;
 479                                         s->nusage ++;
 480                                 }
 481                                 /* else XXX */
 482
 483                                 s->susage = 0;
 484                                 break;
 485                         case 3:
 486                                 c->designator_index = dval;
 487                                 break;
 488                         case 4:
 489                                 c->designator_minimum = dval;
 490                                 break;
 491                         case 5:
 492                                 c->designator_maximum = dval;
 493                                 break;
 494                         case 7:
 495                                 c->string_index = dval;
 496                                 break;
 497                         case 8:
 498                                 c->string_minimum = dval;
 499                                 break;
 500                         case 9:
 501                                 c->string_maximum = dval;
 502                                 break;
 503                         case 10:
 504                                 c->set_delimiter = dval;
 505                                 break;
 506                         default:
 507                                 break;
 508                         }
 509                         break;
 510                 default:
 511                         break;
 512                 }
 513         }
 514         return (0);
 515 }
 516
 517 int
 518 hid_get_item(hid_data_t s, hid_item_t *h)
 519 {
 520         int r;
 521
 522         for (;;) {
 523                 r = hid_get_item_raw(s, h);
 524                 if (r <= 0 || s->reportid == -1 || h->report_ID == s->reportid)
 525                         break;
 526         }
 527         return (r);
 528 }
 529
 530 int
 531 hid_report_size(report_desc_t r, enum hid_kind k, int id)
 532 {
 533         struct hid_data *d;
 534         struct hid_item h;
 535         uint32_t temp;
 536         uint32_t hpos;
 537         uint32_t lpos;
 538         int report_id = 0;
 539
 540         hpos = 0;
 541         lpos = 0xFFFFFFFF;
 542
 543         memset(&h, 0, sizeof h);
 544         for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) {
 545                 if (h.kind == k) {
 546                         /* compute minimum */
 547                         if (lpos > h.pos)
 548                                 lpos = h.pos;
 549                         /* compute end position */
 550                         temp = h.pos + (h.report_size * h.report_count);
 551                         /* compute maximum */
 552                         if (hpos < temp)
 553                                 hpos = temp;
 554                         if (h.report_ID != 0)
 555                                 report_id = 1;
 556                 }
 557         }
 558         hid_end_parse(d);
 559
 560         /* safety check - can happen in case of currupt descriptors */
 561         if (lpos > hpos)
 562                 temp = 0;
 563         else
 564                 temp = hpos - lpos;
 565
 566         /* return length in bytes rounded up */
 567         return ((temp + 7) / 8 + report_id);
 568 }
 569
 570 int
 571 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
 572            hid_item_t *h, int id)
 573 {
 574         struct hid_data *d;
 575
 576         for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) {
 577                 if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
 578                         hid_end_parse(d);
 579                         return (1);
 580                 }
 581         }
 582         hid_end_parse(d);
 583         h->report_size = 0;
 584         return (0);
 585 }