parse.c revision 224511
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: head/lib/libusbhid/parse.c 224511 2011-07-30 13:22:44Z mav $"); 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 47struct hid_pos_data { 48 int32_t rid; 49 uint32_t pos; 50}; 51 52struct 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 *------------------------------------------------------------------------*/ 76static void 77hid_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 92static void 93hid_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 *------------------------------------------------------------------------*/ 145hid_data_t 146hid_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 *------------------------------------------------------------------------*/ 161void 162hid_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 *------------------------------------------------------------------------*/ 174static uint8_t 175hid_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 *------------------------------------------------------------------------*/ 204int 205hid_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 c->usage_minimum = 0; 326 c->usage_maximum = 0; 327 } else { 328 s->ncount = 1; 329 } 330 goto top; 331 332 case 9: /* Output */ 333 c->kind = hid_output; 334 c->flags = dval; 335 goto ret; 336 case 10: /* Collection */ 337 c->kind = hid_collection; 338 c->collection = dval; 339 c->collevel++; 340 c->usage = s->usage_last; 341 *h = *c; 342 return (1); 343 case 11: /* Feature */ 344 c->kind = hid_feature; 345 c->flags = dval; 346 goto ret; 347 case 12: /* End collection */ 348 c->kind = hid_endcollection; 349 if (c->collevel == 0) { 350 /* Invalid end collection. */ 351 return (0); 352 } 353 c->collevel--; 354 *h = *c; 355 return (1); 356 default: 357 break; 358 } 359 break; 360 361 case 1: /* Global */ 362 switch (bTag) { 363 case 0: 364 c->_usage_page = dval << 16; 365 break; 366 case 1: 367 c->logical_minimum = dval; 368 break; 369 case 2: 370 c->logical_maximum = dval; 371 break; 372 case 3: 373 c->physical_minimum = dval; 374 break; 375 case 4: 376 c->physical_maximum = dval; 377 break; 378 case 5: 379 c->unit_exponent = dval; 380 break; 381 case 6: 382 c->unit = dval; 383 break; 384 case 7: 385 /* mask because value is unsigned */ 386 s->loc_size = dval & mask; 387 break; 388 case 8: 389 hid_switch_rid(s, c, dval); 390 break; 391 case 9: 392 /* mask because value is unsigned */ 393 s->loc_count = dval & mask; 394 break; 395 case 10: /* Push */ 396 s->pushlevel ++; 397 if (s->pushlevel < MAXPUSH) { 398 s->cur[s->pushlevel] = *c; 399 /* store size and count */ 400 c->report_size = s->loc_size; 401 c->report_count = s->loc_count; 402 /* update current item pointer */ 403 c = &s->cur[s->pushlevel]; 404 } 405 break; 406 case 11: /* Pop */ 407 s->pushlevel --; 408 if (s->pushlevel < MAXPUSH) { 409 /* preserve position */ 410 oldpos = c->pos; 411 c = &s->cur[s->pushlevel]; 412 /* restore size and count */ 413 s->loc_size = c->report_size; 414 s->loc_count = c->report_count; 415 /* set default item location */ 416 c->pos = oldpos; 417 c->report_size = 0; 418 c->report_count = 0; 419 } 420 break; 421 default: 422 break; 423 } 424 break; 425 case 2: /* Local */ 426 switch (bTag) { 427 case 0: 428 if (bSize != 4) 429 dval = (dval & mask) | c->_usage_page; 430 431 /* set last usage, in case of a collection */ 432 s->usage_last = dval; 433 434 if (s->nusage < MAXUSAGE) { 435 s->usages_min[s->nusage] = dval; 436 s->usages_max[s->nusage] = dval; 437 s->nusage ++; 438 } 439 /* else XXX */ 440 441 /* clear any pending usage sets */ 442 s->susage = 0; 443 break; 444 case 1: 445 s->susage |= 1; 446 447 if (bSize != 4) 448 dval = (dval & mask) | c->_usage_page; 449 c->usage_minimum = dval; 450 451 goto check_set; 452 case 2: 453 s->susage |= 2; 454 455 if (bSize != 4) 456 dval = (dval & mask) | c->_usage_page; 457 c->usage_maximum = dval; 458 459 check_set: 460 if (s->susage != 3) 461 break; 462 463 /* sanity check */ 464 if ((s->nusage < MAXUSAGE) && 465 (c->usage_minimum <= c->usage_maximum)) { 466 /* add usage range */ 467 s->usages_min[s->nusage] = 468 c->usage_minimum; 469 s->usages_max[s->nusage] = 470 c->usage_maximum; 471 s->nusage ++; 472 } 473 /* else XXX */ 474 475 s->susage = 0; 476 break; 477 case 3: 478 c->designator_index = dval; 479 break; 480 case 4: 481 c->designator_minimum = dval; 482 break; 483 case 5: 484 c->designator_maximum = dval; 485 break; 486 case 7: 487 c->string_index = dval; 488 break; 489 case 8: 490 c->string_minimum = dval; 491 break; 492 case 9: 493 c->string_maximum = dval; 494 break; 495 case 10: 496 c->set_delimiter = dval; 497 break; 498 default: 499 break; 500 } 501 break; 502 default: 503 break; 504 } 505 } 506 return (0); 507} 508 509int 510hid_report_size(report_desc_t r, enum hid_kind k, int id) 511{ 512 struct hid_data *d; 513 struct hid_item h; 514 uint32_t temp; 515 uint32_t hpos; 516 uint32_t lpos; 517 int report_id = 0; 518 519 hpos = 0; 520 lpos = 0xFFFFFFFF; 521 522 memset(&h, 0, sizeof h); 523 for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) { 524 if ((h.report_ID == id || id < 0) && h.kind == k) { 525 /* compute minimum */ 526 if (lpos > h.pos) 527 lpos = h.pos; 528 /* compute end position */ 529 temp = h.pos + (h.report_size * h.report_count); 530 /* compute maximum */ 531 if (hpos < temp) 532 hpos = temp; 533 if (h.report_ID != 0) 534 report_id = 1; 535 } 536 } 537 hid_end_parse(d); 538 539 /* safety check - can happen in case of currupt descriptors */ 540 if (lpos > hpos) 541 temp = 0; 542 else 543 temp = hpos - lpos; 544 545 /* return length in bytes rounded up */ 546 return ((temp + 7) / 8 + report_id); 547} 548 549int 550hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k, 551 hid_item_t *h, int id) 552{ 553 struct hid_data *d; 554 555 for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) { 556 if (h->kind == k && !(h->flags & HIO_CONST) && h->usage == u) { 557 hid_end_parse(d); 558 return (1); 559 } 560 } 561 hid_end_parse(d); 562 h->report_size = 0; 563 return (0); 564} 565