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 s->pushlevel ++; 407 if (s->pushlevel < MAXPUSH) { 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 } 415 break; 416 case 11: /* Pop */ 417 s->pushlevel --; 418 if (s->pushlevel < MAXPUSH) { 419 c = &s->cur[s->pushlevel]; 420 /* restore size and count */ 421 s->loc_size = c->report_size; 422 s->loc_count = c->report_count; 423 c->report_size = 0; 424 c->report_count = 0; 425 } 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 } 584