1 /* $NetBSD: parse.c,v 1.11 2000/09/24 02:19:54 augustss Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-2-Clause 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 #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 } 584