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         int32_t reportid;       /* requested report ID */
  74 };
  75
  76 /*------------------------------------------------------------------------*
  77  *      hid_clear_local
  78  *------------------------------------------------------------------------*/
  79 static void
  80 hid_clear_local(hid_item_t *c)
  81 {
  82
  83         c->usage = 0;
  84         c->usage_minimum = 0;
  85         c->usage_maximum = 0;
  86         c->designator_index = 0;
  87         c->designator_minimum = 0;
  88         c->designator_maximum = 0;
  89         c->string_index = 0;
  90         c->string_minimum = 0;
  91         c->string_maximum = 0;
  92         c->set_delimiter = 0;
  93 }
  94
  95 static void
  96 hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID)
  97 {
  98         uint8_t i, j;
  99
 100         /* check for same report ID - optimise */
 101
 102         if (c->report_ID == next_rID)
 103                 return;
 104
 105         /* save current position for current rID */
 106
 107         if (c->report_ID == 0) {
 108                 i = 0;
 109         } else {
 110                 for (i = 1; i != MAXID; i++) {
 111                         if (s->last_pos[i].rid == c->report_ID)
 112                                 break;
 113                         if (s->last_pos[i].rid == 0)
 114                                 break;
 115                 }
 116         }
 117         if (i != MAXID) {
 118                 s->last_pos[i].rid = c->report_ID;
 119                 for (j = 0; j < ITEMTYPES; j++)
 120                         s->last_pos[i].pos[j] = s->pos[j];
 121         }
 122
 123         /* store next report ID */
 124
 125         c->report_ID = next_rID;
 126
 127         /* lookup last position for next rID */
 128
 129         if (next_rID == 0) {
 130                 i = 0;
 131         } else {
 132                 for (i = 1; i != MAXID; i++) {
 133                         if (s->last_pos[i].rid == next_rID)
 134                                 break;
 135                         if (s->last_pos[i].rid == 0)
 136                                 break;
 137                 }
 138         }
 139         if (i != MAXID) {
 140                 s->last_pos[i].rid = next_rID;
 141                 for (j = 0; j < ITEMTYPES; j++)
 142                         s->pos[j] = s->last_pos[i].pos[j];
 143         } else {
 144                 for (j = 0; j < ITEMTYPES; j++)
 145                         s->pos[j] = 0;  /* Out of RID entries. */
 146         }
 147 }
 148
 149 /*------------------------------------------------------------------------*
 150  *      hid_start_parse
 151  *------------------------------------------------------------------------*/
 152 hid_data_t
 153 hid_start_parse(report_desc_t d, int kindset, int id)
 154 {
 155         struct hid_data *s;
 156
 157         s = malloc(sizeof *s);
 158         memset(s, 0, sizeof *s);
 159         s->start = s->p = d->data;
 160         s->end = d->data + d->size;
 161         s->kindset = kindset;
 162         s->reportid = id;
 163         return (s);
 164 }
 165
 166 /*------------------------------------------------------------------------*
 167  *      hid_end_parse
 168  *------------------------------------------------------------------------*/
 169 void
 170 hid_end_parse(hid_data_t s)
 171 {
 172
 173         if (s == NULL)
 174                 return;
 175
 176         free(s);
 177 }
 178
 179 /*------------------------------------------------------------------------*
 180  *      get byte from HID descriptor
 181  *------------------------------------------------------------------------*/
 182 static uint8_t
 183 hid_get_byte(struct hid_data *s, const uint16_t wSize)
 184 {
 185         const uint8_t *ptr;
 186         uint8_t retval;
 187
 188         ptr = s->p;
 189
 190         /* check if end is reached */
 191         if (ptr == s->end)
 192                 return (0);
 193
 194         /* read out a byte */
 195         retval = *ptr;
 196
 197         /* check if data pointer can be advanced by "wSize" bytes */
 198         if ((s->end - ptr) < wSize)
 199                 ptr = s->end;
 200         else
 201                 ptr += wSize;
 202
 203         /* update pointer */
 204         s->p = ptr;
 205
 206         return (retval);
 207 }
 208
 209 /*------------------------------------------------------------------------*
 210  *      hid_get_item
 211  *------------------------------------------------------------------------*/
 212 static int
 213 hid_get_item_raw(hid_data_t s, hid_item_t *h)
 214 {
 215         hid_item_t *c;
 216         unsigned int bTag, bType, bSize;
 217         int32_t mask;
 218         int32_t dval;
 219
 220         if (s == NULL)
 221                 return (0);
 222
 223         c = &s->cur[s->pushlevel];
 224
 225  top:
 226         /* check if there is an array of items */
 227         if (s->icount < s->ncount) {
 228                 /* get current usage */
 229                 if (s->iusage < s->nusage) {
 230                         dval = s->usages_min[s->iusage] + s->ousage;
 231                         c->usage = dval;
 232                         s->usage_last = dval;
 233                         if (dval == s->usages_max[s->iusage]) {
 234                                 s->iusage ++;
 235                                 s->ousage = 0;
 236                         } else {
 237                                 s->ousage ++;
 238                         }
 239                 } else {
 240                         /* Using last usage */
 241                         dval = s->usage_last;
 242                 }
 243                 s->icount ++;
 244                 /*
 245                  * Only copy HID item, increment position and return
 246                  * if correct kindset!
 247                  */
 248                 if (s->kindset & (1 << c->kind)) {
 249                         *h = *c;
 250                         h->pos = s->pos[c->kind];
 251                         s->pos[c->kind] += c->report_size * c->report_count;
 252                         return (1);
 253                 }
 254         }
 255
 256         /* reset state variables */
 257         s->icount = 0;
 258         s->ncount = 0;
 259         s->iusage = 0;
 260         s->nusage = 0;
 261         s->susage = 0;
 262         s->ousage = 0;
 263         hid_clear_local(c);
 264
 265         /* get next item */
 266         while (s->p != s->end) {
 267
 268                 bSize = hid_get_byte(s, 1);
 269                 if (bSize == 0xfe) {
 270                         /* long item */
 271                         bSize = hid_get_byte(s, 1);
 272                         bSize |= hid_get_byte(s, 1) << 8;
 273                         bTag = hid_get_byte(s, 1);
 274                         bType = 0xff;   /* XXX what should it be */
 275                 } else {
 276                         /* short item */
 277                         bTag = bSize >> 4;
 278                         bType = (bSize >> 2) & 3;
 279                         bSize &= 3;
 280                         if (bSize == 3)
 281                                 bSize = 4;
 282                 }
 283
 284                 switch(bSize) {
 285                 case 0:
 286                         dval = 0;
 287                         mask = 0;
 288                         break;
 289                 case 1:
 290                         dval = (int8_t)hid_get_byte(s, 1);
 291                         mask = 0xFF;
 292                         break;
 293                 case 2:
 294                         dval = hid_get_byte(s, 1);
 295                         dval |= hid_get_byte(s, 1) << 8;
 296                         dval = (int16_t)dval;
 297                         mask = 0xFFFF;
 298                         break;
 299                 case 4:
 300                         dval = hid_get_byte(s, 1);
 301                         dval |= hid_get_byte(s, 1) << 8;
 302                         dval |= hid_get_byte(s, 1) << 16;
 303                         dval |= hid_get_byte(s, 1) << 24;
 304                         mask = 0xFFFFFFFF;
 305                         break;
 306                 default:
 307                         dval = hid_get_byte(s, bSize);
 308                         continue;
 309                 }
 310
 311                 switch (bType) {
 312                 case 0:         /* Main */
 313                         switch (bTag) {
 314                         case 8: /* Input */
 315                                 c->kind = hid_input;
 316                                 c->flags = dval;
 317                 ret:
 318                                 c->report_count = s->loc_count;
 319                                 c->report_size = s->loc_size;
 320
 321                                 if (c->flags & HIO_VARIABLE) {
 322                                         /* range check usage count */
 323                                         if (c->report_count > 255) {
 324                                                 s->ncount = 255;
 325                                         } else
 326                                                 s->ncount = c->report_count;
 327
 328                                         /*
 329                                          * The "top" loop will return
 330                                          * one and one item:
 331                                          */
 332                                         c->report_count = 1;
 333                                         c->usage_minimum = 0;
 334                                         c->usage_maximum = 0;
 335                                 } else {
 336                                         s->ncount = 1;
 337                                 }
 338                                 goto top;
 339
 340                         case 9: /* Output */
 341                                 c->kind = hid_output;
 342                                 c->flags = dval;
 343                                 goto ret;
 344                         case 10:        /* Collection */
 345                                 c->kind = hid_collection;
 346                                 c->collection = dval;
 347                                 c->collevel++;
 348                                 c->usage = s->usage_last;
 349                                 *h = *c;
 350                                 return (1);
 351                         case 11:        /* Feature */
 352                                 c->kind = hid_feature;
 353                                 c->flags = dval;
 354                                 goto ret;
 355                         case 12:        /* End collection */
 356                                 c->kind = hid_endcollection;
 357                                 if (c->collevel == 0) {
 358                                         /* Invalid end collection. */
 359                                         return (0);
 360                                 }
 361                                 c->collevel--;
 362                                 *h = *c;
 363                                 return (1);
 364                         default:
 365                                 break;
 366                         }
 367                         break;
 368
 369                 case 1:         /* Global */
 370                         switch (bTag) {
 371                         case 0:
 372                                 c->_usage_page = dval << 16;
 373                                 break;
 374                         case 1:
 375                                 c->logical_minimum = dval;
 376                                 break;
 377                         case 2:
 378                                 c->logical_maximum = dval;
 379                                 break;
 380                         case 3:
 381                                 c->physical_minimum = dval;
 382                                 break;
 383                         case 4:
 384                                 c->physical_maximum = dval;
 385                                 break;
 386                         case 5:
 387                                 c->unit_exponent = dval;
 388                                 break;
 389                         case 6:
 390                                 c->unit = dval;
 391                                 break;
 392                         case 7:
 393                                 /* mask because value is unsigned */
 394                                 s->loc_size = dval & mask;
 395                                 break;
 396                         case 8:
 397                                 hid_switch_rid(s, c, dval & mask);
 398                                 break;
 399                         case 9:
 400                                 /* mask because value is unsigned */
 401                                 s->loc_count = dval & mask;
 402                                 break;
 403                         case 10:        /* Push */
 404                                 /* stop parsing, if invalid push level */
 405                                 if ((s->pushlevel + 1) >= MAXPUSH)
 406                                         return (0);
 407                                 s->pushlevel ++;
 408                                 s->cur[s->pushlevel] = *c;
 409                                 /* store size and count */
 410                                 c->report_size = s->loc_size;
 411                                 c->report_count = s->loc_count;
 412                                 /* update current item pointer */
 413                                 c = &s->cur[s->pushlevel];
 414                                 break;
 415                         case 11:        /* Pop */
 416                                 /* stop parsing, if invalid push level */
 417                                 if (s->pushlevel == 0)
 418                                         return (0);
 419                                 s->pushlevel --;
 420                                 c = &s->cur[s->pushlevel];
 421                                 /* restore size and count */
 422                                 s->loc_size = c->report_size;
 423                                 s->loc_count = c->report_count;
 424                                 c->report_size = 0;
 425                                 c->report_count = 0;
 426                                 break;
 427                         default:
 428                                 break;
 429                         }
 430                         break;
 431                 case 2:         /* Local */
 432                         switch (bTag) {
 433                         case 0:
 434                                 if (bSize != 4)
 435                                         dval = (dval & mask) | c->_usage_page;
 436
 437                                 /* set last usage, in case of a collection */
 438                                 s->usage_last = dval;
 439
 440                                 if (s->nusage < MAXUSAGE) {
 441                                         s->usages_min[s->nusage] = dval;
 442                                         s->usages_max[s->nusage] = dval;
 443                                         s->nusage ++;
 444                                 }
 445                                 /* else XXX */
 446
 447                                 /* clear any pending usage sets */
 448                                 s->susage = 0;
 449                                 break;
 450                         case 1:
 451                                 s->susage |= 1;
 452
 453                                 if (bSize != 4)
 454                                         dval = (dval & mask) | c->_usage_page;
 455                                 c->usage_minimum = dval;
 456
 457                                 goto check_set;
 458                         case 2:
 459                                 s->susage |= 2;
 460
 461                                 if (bSize != 4)
 462                                         dval = (dval & mask) | c->_usage_page;
 463                                 c->usage_maximum = dval;
 464
 465                         check_set:
 466                                 if (s->susage != 3)
 467                                         break;
 468
 469                                 /* sanity check */
 470                                 if ((s->nusage < MAXUSAGE) &&
 471                                     (c->usage_minimum <= c->usage_maximum)) {
 472                                         /* add usage range */
 473                                         s->usages_min[s->nusage] =
 474                                             c->usage_minimum;
 475                                         s->usages_max[s->nusage] =
 476                                             c->usage_maximum;
 477                                         s->nusage ++;
 478                                 }
 479                                 /* else XXX */
 480
 481                                 s->susage = 0;
 482                                 break;
 483                         case 3:
 484                                 c->designator_index = dval;
 485                                 break;
 486                         case 4:
 487                                 c->designator_minimum = dval;
 488                                 break;
 489                         case 5:
 490                                 c->designator_maximum = dval;
 491                                 break;
 492                         case 7:
 493                                 c->string_index = dval;
 494                                 break;
 495                         case 8:
 496                                 c->string_minimum = dval;
 497                                 break;
 498                         case 9:
 499                                 c->string_maximum = dval;
 500                                 break;
 501                         case 10:
 502                                 c->set_delimiter = dval;
 503                                 break;
 504                         default:
 505                                 break;
 506                         }
 507                         break;
 508                 default:
 509                         break;
 510                 }
 511         }
 512         return (0);
 513 }
 514
 515 int
 516 hid_get_item(hid_data_t s, hid_item_t *h)
 517 {
 518         int r;
 519
 520         for (;;) {
 521                 r = hid_get_item_raw(s, h);
 522                 if (r <= 0 || s->reportid == -1 || h->report_ID == s->reportid)
 523                         break;
 524         }
 525         return (r);
 526 }
 527
 528 int
 529 hid_report_size(report_desc_t r, enum hid_kind k, int id)
 530 {
 531         struct hid_data *d;
 532         struct hid_item h;
 533         uint32_t temp;
 534         uint32_t hpos;
 535         uint32_t lpos;
 536         int report_id = 0;
 537
 538         hpos = 0;
 539         lpos = 0xFFFFFFFF;
 540
 541         memset(&h, 0, sizeof h);
 542         for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) {
 543                 if (h.kind == k) {
 544                         /* compute minimum */
 545                         if (lpos > h.pos)
 546                                 lpos = h.pos;
 547                         /* compute end position */
 548                         temp = h.pos + (h.report_size * h.report_count);
 549                         /* compute maximum */
 550                         if (hpos < temp)
 551                                 hpos = temp;
 552                         if (h.report_ID != 0)
 553                                 report_id = 1;
 554                 }
 555         }
 556         hid_end_parse(d);
 557
 558         /* safety check - can happen in case of currupt descriptors */
 559         if (lpos > hpos)
 560                 temp = 0;
 561         else
 562                 temp = hpos - lpos;
 563
 564         /* return length in bytes rounded up */
 565         return ((temp + 7) / 8 + report_id);
 566 }
 567
 568 int
 569 hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k,
 570            hid_item_t *h, int id)
 571 {
 572         struct hid_data *d;
 573
 574         for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) {
 575                 if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) {
 576                         hid_end_parse(d);
 577                         return (1);
 578                 }
 579         }
 580         hid_end_parse(d);
 581         h->report_size = 0;
 582         return (0);
 583 }