| File: | src/lib/libusbhid/parse.c |
| Warning: | line 560, column 5 Value stored to 'report_id' is never read |
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| 1 | /* $OpenBSD: parse.c,v 1.13 2022/12/27 17:10:07 jmc Exp $ */ |
| 2 | /* $NetBSD: parse.c,v 1.2 2001/12/29 20:44:22 augustss Exp $ */ |
| 3 | |
| 4 | /* |
| 5 | * Copyright (c) 1999, 2001 Lennart Augustsson <augustss@netbsd.org> |
| 6 | * All rights reserved. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | */ |
| 29 | |
| 30 | #include <stdlib.h> |
| 31 | #include <string.h> |
| 32 | |
| 33 | #include <dev/usb/usb.h> |
| 34 | #include <dev/usb/usbhid.h> |
| 35 | |
| 36 | #include "usbhid.h" |
| 37 | #include "usbvar.h" |
| 38 | |
| 39 | #define MAXUSAGE100 100 |
| 40 | #define MAXPUSH4 4 |
| 41 | #define MAXID64 64 |
| 42 | #define ITEMTYPES3 3 |
| 43 | |
| 44 | struct hid_pos_data { |
| 45 | int32_t rid; |
| 46 | uint32_t pos[ITEMTYPES3]; |
| 47 | }; |
| 48 | |
| 49 | struct hid_data { |
| 50 | const uint8_t *start; |
| 51 | const uint8_t *end; |
| 52 | const uint8_t *p; |
| 53 | struct hid_item cur[MAXPUSH4]; |
| 54 | struct hid_pos_data last_pos[MAXID64]; |
| 55 | uint32_t pos[ITEMTYPES3]; |
| 56 | int32_t usages_min[MAXUSAGE100]; |
| 57 | int32_t usages_max[MAXUSAGE100]; |
| 58 | int32_t usage_last; /* last seen usage */ |
| 59 | uint32_t loc_size; /* last seen size */ |
| 60 | uint32_t loc_count; /* last seen count */ |
| 61 | uint8_t kindset; /* we have 5 kinds so 8 bits are enough */ |
| 62 | uint8_t pushlevel; /* current pushlevel */ |
| 63 | uint8_t ncount; /* end usage item count */ |
| 64 | uint8_t icount; /* current usage item count */ |
| 65 | uint8_t nusage; /* end "usages_min/max" index */ |
| 66 | uint8_t iusage; /* current "usages_min/max" index */ |
| 67 | uint8_t ousage; /* current "usages_min/max" offset */ |
| 68 | uint8_t susage; /* usage set flags */ |
| 69 | int32_t reportid; /* requested report ID */ |
| 70 | struct hid_item savedcoll; /* save coll until we know the ID */ |
| 71 | uint8_t hassavedcoll; |
| 72 | }; |
| 73 | |
| 74 | static void |
| 75 | hid_clear_local(hid_item_t *c) |
| 76 | { |
| 77 | |
| 78 | c->usage = 0; |
| 79 | c->usage_minimum = 0; |
| 80 | c->usage_maximum = 0; |
| 81 | c->designator_index = 0; |
| 82 | c->designator_minimum = 0; |
| 83 | c->designator_maximum = 0; |
| 84 | c->string_index = 0; |
| 85 | c->string_minimum = 0; |
| 86 | c->string_maximum = 0; |
| 87 | c->set_delimiter = 0; |
| 88 | } |
| 89 | |
| 90 | static void |
| 91 | hid_switch_rid(struct hid_data *s, struct hid_item *c, int32_t next_rID) |
| 92 | { |
| 93 | uint8_t i, j; |
| 94 | |
| 95 | /* check for same report ID - optimise */ |
| 96 | |
| 97 | if (c->report_ID == next_rID) |
| 98 | return; |
| 99 | |
| 100 | /* save current position for current rID */ |
| 101 | |
| 102 | if (c->report_ID == 0) { |
| 103 | i = 0; |
| 104 | } else { |
| 105 | for (i = 1; i != MAXID64; i++) { |
| 106 | if (s->last_pos[i].rid == c->report_ID) |
| 107 | break; |
| 108 | if (s->last_pos[i].rid == 0) |
| 109 | break; |
| 110 | } |
| 111 | } |
| 112 | if (i != MAXID64) { |
| 113 | s->last_pos[i].rid = c->report_ID; |
| 114 | for (j = 0; j < ITEMTYPES3; j++) |
| 115 | s->last_pos[i].pos[j] = s->pos[j]; |
| 116 | } |
| 117 | |
| 118 | /* store next report ID */ |
| 119 | |
| 120 | c->report_ID = next_rID; |
| 121 | |
| 122 | /* lookup last position for next rID */ |
| 123 | |
| 124 | if (next_rID == 0) { |
| 125 | i = 0; |
| 126 | } else { |
| 127 | for (i = 1; i != MAXID64; i++) { |
| 128 | if (s->last_pos[i].rid == next_rID) |
| 129 | break; |
| 130 | if (s->last_pos[i].rid == 0) |
| 131 | break; |
| 132 | } |
| 133 | } |
| 134 | if (i != MAXID64) { |
| 135 | s->last_pos[i].rid = next_rID; |
| 136 | for (j = 0; j < ITEMTYPES3; j++) |
| 137 | s->pos[j] = s->last_pos[i].pos[j]; |
| 138 | } else { |
| 139 | for (j = 0; j < ITEMTYPES3; j++) |
| 140 | s->pos[j] = 0; /* Out of RID entries. */ |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | hid_data_t |
| 145 | hid_start_parse(report_desc_t d, int kindset, int id) |
| 146 | { |
| 147 | struct hid_data *s; |
| 148 | |
| 149 | s = calloc(1, sizeof *s); |
| 150 | if (s == NULL((void *)0)) |
| 151 | return (NULL((void *)0)); |
| 152 | s->start = s->p = d->data; |
| 153 | s->end = d->data + d->size; |
| 154 | s->kindset = kindset; |
| 155 | s->reportid = id; |
| 156 | s->hassavedcoll = 0; |
| 157 | return (s); |
| 158 | } |
| 159 | |
| 160 | void |
| 161 | hid_end_parse(hid_data_t s) |
| 162 | { |
| 163 | |
| 164 | if (s == NULL((void *)0)) |
| 165 | return; |
| 166 | |
| 167 | free(s); |
| 168 | } |
| 169 | |
| 170 | static uint8_t |
| 171 | hid_get_byte(struct hid_data *s, const uint16_t wSize) |
| 172 | { |
| 173 | const uint8_t *ptr; |
| 174 | uint8_t retval; |
| 175 | |
| 176 | ptr = s->p; |
| 177 | |
| 178 | /* check if end is reached */ |
| 179 | if (ptr == s->end) |
| 180 | return (0); |
| 181 | |
| 182 | /* read out a byte */ |
| 183 | retval = *ptr; |
| 184 | |
| 185 | /* check if data pointer can be advanced by "wSize" bytes */ |
| 186 | if ((s->end - ptr) < wSize) |
| 187 | ptr = s->end; |
| 188 | else |
| 189 | ptr += wSize; |
| 190 | |
| 191 | /* update pointer */ |
| 192 | s->p = ptr; |
| 193 | |
| 194 | return (retval); |
| 195 | } |
| 196 | |
| 197 | #define REPORT_SAVED_COLLdo { if (s->hassavedcoll) { *h = s->savedcoll; h->report_ID = c->report_ID; s->hassavedcoll = 0; return (1); } } while (0) \ |
| 198 | do { \ |
| 199 | if (s->hassavedcoll) { \ |
| 200 | *h = s->savedcoll; \ |
| 201 | h->report_ID = c->report_ID; \ |
| 202 | s->hassavedcoll = 0; \ |
| 203 | return (1); \ |
| 204 | } \ |
| 205 | } while(0) |
| 206 | |
| 207 | static int |
| 208 | hid_get_item_raw(hid_data_t s, hid_item_t *h) |
| 209 | { |
| 210 | hid_item_t nc, *c; |
| 211 | unsigned int bTag, bType, bSize; |
| 212 | int32_t mask; |
| 213 | int32_t dval; |
| 214 | |
| 215 | if (s == NULL((void *)0)) |
| 216 | return (0); |
| 217 | |
| 218 | if (s->pushlevel >= MAXPUSH4) |
| 219 | return (0); |
| 220 | |
| 221 | c = &s->cur[s->pushlevel]; |
| 222 | |
| 223 | top: |
| 224 | /* check if there is an array of items */ |
| 225 | if (s->icount < s->ncount) { |
| 226 | REPORT_SAVED_COLLdo { if (s->hassavedcoll) { *h = s->savedcoll; h->report_ID = c->report_ID; s->hassavedcoll = 0; return (1); } } while (0); |
| 227 | /* get current usage */ |
| 228 | if (s->iusage < s->nusage) { |
| 229 | dval = s->usages_min[s->iusage] + s->ousage; |
| 230 | c->usage = dval; |
| 231 | s->usage_last = dval; |
| 232 | if (dval == s->usages_max[s->iusage]) { |
| 233 | s->iusage ++; |
| 234 | s->ousage = 0; |
| 235 | } else { |
| 236 | s->ousage ++; |
| 237 | } |
| 238 | } else { |
| 239 | /* Using last usage */ |
| 240 | dval = s->usage_last; |
| 241 | } |
| 242 | s->icount ++; |
| 243 | /* |
| 244 | * Only copy HID item, increment position and return |
| 245 | * if correct kindset! |
| 246 | */ |
| 247 | if (s->kindset & (1 << c->kind)) { |
| 248 | *h = *c; |
| 249 | h->pos = s->pos[c->kind]; |
| 250 | s->pos[c->kind] += c->report_size * c->report_count; |
| 251 | return (1); |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | /* reset state variables */ |
| 256 | s->icount = 0; |
| 257 | s->ncount = 0; |
| 258 | s->iusage = 0; |
| 259 | s->nusage = 0; |
| 260 | s->susage = 0; |
| 261 | s->ousage = 0; |
| 262 | hid_clear_local(c); |
| 263 | |
| 264 | /* get next item */ |
| 265 | while (s->p != s->end) { |
| 266 | |
| 267 | bSize = hid_get_byte(s, 1); |
| 268 | if (bSize == 0xfe) { |
| 269 | /* long item */ |
| 270 | bSize = hid_get_byte(s, 1); |
| 271 | bSize |= hid_get_byte(s, 1) << 8; |
| 272 | bTag = hid_get_byte(s, 1); |
| 273 | bType = 0xff; /* XXX what should it be */ |
| 274 | } else { |
| 275 | /* short item */ |
| 276 | bTag = bSize >> 4; |
| 277 | bType = (bSize >> 2) & 3; |
| 278 | bSize &= 3; |
| 279 | if (bSize == 3) |
| 280 | bSize = 4; |
| 281 | } |
| 282 | |
| 283 | switch(bSize) { |
| 284 | case 0: |
| 285 | dval = 0; |
| 286 | mask = 0; |
| 287 | break; |
| 288 | case 1: |
| 289 | dval = (int8_t)hid_get_byte(s, 1); |
| 290 | mask = 0xFF; |
| 291 | break; |
| 292 | case 2: |
| 293 | dval = hid_get_byte(s, 1); |
| 294 | dval |= hid_get_byte(s, 1) << 8; |
| 295 | dval = (int16_t)dval; |
| 296 | mask = 0xFFFF; |
| 297 | break; |
| 298 | case 4: |
| 299 | dval = hid_get_byte(s, 1); |
| 300 | dval |= hid_get_byte(s, 1) << 8; |
| 301 | dval |= hid_get_byte(s, 1) << 16; |
| 302 | dval |= hid_get_byte(s, 1) << 24; |
| 303 | mask = 0xFFFFFFFF; |
| 304 | break; |
| 305 | default: |
| 306 | dval = hid_get_byte(s, bSize); |
| 307 | continue; |
| 308 | } |
| 309 | |
| 310 | switch (bType) { |
| 311 | case 0: /* Main */ |
| 312 | switch (bTag) { |
| 313 | case 8: /* Input */ |
| 314 | c->kind = hid_input; |
| 315 | c->flags = dval; |
| 316 | ret: |
| 317 | c->report_count = s->loc_count; |
| 318 | c->report_size = s->loc_size; |
| 319 | |
| 320 | if (c->flags & HIO_VARIABLE0x002) { |
| 321 | /* range check usage count */ |
| 322 | if (c->report_count > 255) { |
| 323 | s->ncount = 255; |
| 324 | } else |
| 325 | s->ncount = c->report_count; |
| 326 | |
| 327 | /* |
| 328 | * The "top" loop will return |
| 329 | * one and one item: |
| 330 | */ |
| 331 | c->report_count = 1; |
| 332 | c->usage_minimum = 0; |
| 333 | c->usage_maximum = 0; |
| 334 | } else { |
| 335 | s->ncount = 1; |
| 336 | } |
| 337 | goto top; |
| 338 | |
| 339 | case 9: /* Output */ |
| 340 | c->kind = hid_output; |
| 341 | c->flags = dval; |
| 342 | goto ret; |
| 343 | case 10: /* Collection */ |
| 344 | c->kind = hid_collection; |
| 345 | c->collection = dval; |
| 346 | c->collevel++; |
| 347 | c->usage = s->usage_last; |
| 348 | nc = *c; |
| 349 | if (s->hassavedcoll) { |
| 350 | *h = s->savedcoll; |
| 351 | h->report_ID = nc.report_ID; |
| 352 | s->savedcoll = nc; |
| 353 | return (1); |
| 354 | } else { |
| 355 | s->hassavedcoll = 1; |
| 356 | s->savedcoll = nc; |
| 357 | } |
| 358 | goto top; |
| 359 | case 11: /* Feature */ |
| 360 | c->kind = hid_feature; |
| 361 | c->flags = dval; |
| 362 | goto ret; |
| 363 | case 12: /* End collection */ |
| 364 | REPORT_SAVED_COLLdo { if (s->hassavedcoll) { *h = s->savedcoll; h->report_ID = c->report_ID; s->hassavedcoll = 0; return (1); } } while (0); |
| 365 | c->kind = hid_endcollection; |
| 366 | if (c->collevel == 0) { |
| 367 | /* Invalid end collection. */ |
| 368 | return (0); |
| 369 | } |
| 370 | c->collevel--; |
| 371 | *h = *c; |
| 372 | return (1); |
| 373 | default: |
| 374 | break; |
| 375 | } |
| 376 | break; |
| 377 | |
| 378 | case 1: /* Global */ |
| 379 | switch (bTag) { |
| 380 | case 0: |
| 381 | c->_usage_page = dval << 16; |
| 382 | break; |
| 383 | case 1: |
| 384 | c->logical_minimum = dval; |
| 385 | break; |
| 386 | case 2: |
| 387 | c->logical_maximum = dval; |
| 388 | break; |
| 389 | case 3: |
| 390 | c->physical_minimum = dval; |
| 391 | break; |
| 392 | case 4: |
| 393 | c->physical_maximum = dval; |
| 394 | break; |
| 395 | case 5: |
| 396 | c->unit_exponent = dval; |
| 397 | break; |
| 398 | case 6: |
| 399 | c->unit = dval; |
| 400 | break; |
| 401 | case 7: |
| 402 | /* mask because value is unsigned */ |
| 403 | s->loc_size = dval & mask; |
| 404 | break; |
| 405 | case 8: |
| 406 | hid_switch_rid(s, c, dval & mask); |
| 407 | break; |
| 408 | case 9: |
| 409 | /* mask because value is unsigned */ |
| 410 | s->loc_count = dval & mask; |
| 411 | break; |
| 412 | case 10: /* Push */ |
| 413 | if (s->pushlevel < MAXPUSH4 - 1) { |
| 414 | s->pushlevel++; |
| 415 | s->cur[s->pushlevel] = *c; |
| 416 | /* store size and count */ |
| 417 | c->report_size = s->loc_size; |
| 418 | c->report_count = s->loc_count; |
| 419 | /* update current item pointer */ |
| 420 | c = &s->cur[s->pushlevel]; |
| 421 | } |
| 422 | break; |
| 423 | case 11: /* Pop */ |
| 424 | if (s->pushlevel > 0) { |
| 425 | s->pushlevel--; |
| 426 | c = &s->cur[s->pushlevel]; |
| 427 | /* restore size and count */ |
| 428 | s->loc_size = c->report_size; |
| 429 | s->loc_count = c->report_count; |
| 430 | c->report_size = 0; |
| 431 | c->report_count = 0; |
| 432 | } |
| 433 | break; |
| 434 | default: |
| 435 | break; |
| 436 | } |
| 437 | break; |
| 438 | case 2: /* Local */ |
| 439 | switch (bTag) { |
| 440 | case 0: |
| 441 | if (bSize != 4) |
| 442 | dval = (dval & mask) | c->_usage_page; |
| 443 | |
| 444 | /* set last usage, in case of a collection */ |
| 445 | s->usage_last = dval; |
| 446 | |
| 447 | if (s->nusage < MAXUSAGE100) { |
| 448 | s->usages_min[s->nusage] = dval; |
| 449 | s->usages_max[s->nusage] = dval; |
| 450 | s->nusage ++; |
| 451 | } |
| 452 | /* else XXX */ |
| 453 | |
| 454 | /* clear any pending usage sets */ |
| 455 | s->susage = 0; |
| 456 | break; |
| 457 | case 1: |
| 458 | s->susage |= 1; |
| 459 | |
| 460 | if (bSize != 4) |
| 461 | dval = (dval & mask) | c->_usage_page; |
| 462 | c->usage_minimum = dval; |
| 463 | |
| 464 | goto check_set; |
| 465 | case 2: |
| 466 | s->susage |= 2; |
| 467 | |
| 468 | if (bSize != 4) |
| 469 | dval = (dval & mask) | c->_usage_page; |
| 470 | c->usage_maximum = dval; |
| 471 | |
| 472 | check_set: |
| 473 | if (s->susage != 3) |
| 474 | break; |
| 475 | |
| 476 | /* sanity check */ |
| 477 | if ((s->nusage < MAXUSAGE100) && |
| 478 | (c->usage_minimum <= c->usage_maximum)) { |
| 479 | /* add usage range */ |
| 480 | s->usages_min[s->nusage] = |
| 481 | c->usage_minimum; |
| 482 | s->usages_max[s->nusage] = |
| 483 | c->usage_maximum; |
| 484 | s->nusage ++; |
| 485 | } |
| 486 | /* else XXX */ |
| 487 | |
| 488 | s->susage = 0; |
| 489 | break; |
| 490 | case 3: |
| 491 | c->designator_index = dval; |
| 492 | break; |
| 493 | case 4: |
| 494 | c->designator_minimum = dval; |
| 495 | break; |
| 496 | case 5: |
| 497 | c->designator_maximum = dval; |
| 498 | break; |
| 499 | case 7: |
| 500 | c->string_index = dval; |
| 501 | break; |
| 502 | case 8: |
| 503 | c->string_minimum = dval; |
| 504 | break; |
| 505 | case 9: |
| 506 | c->string_maximum = dval; |
| 507 | break; |
| 508 | case 10: |
| 509 | c->set_delimiter = dval; |
| 510 | break; |
| 511 | default: |
| 512 | break; |
| 513 | } |
| 514 | break; |
| 515 | default: |
| 516 | break; |
| 517 | } |
| 518 | } |
| 519 | return (0); |
| 520 | } |
| 521 | |
| 522 | int |
| 523 | hid_get_item(hid_data_t s, hid_item_t *h) |
| 524 | { |
| 525 | int r; |
| 526 | |
| 527 | for (;;) { |
| 528 | r = hid_get_item_raw(s, h); |
| 529 | if (r <= 0 || s->reportid == -1 || h->report_ID == s->reportid) |
| 530 | break; |
| 531 | } |
| 532 | return (r); |
| 533 | } |
| 534 | |
| 535 | int |
| 536 | hid_report_size(report_desc_t r, enum hid_kind k, int id) |
| 537 | { |
| 538 | struct hid_data *d; |
| 539 | struct hid_item h; |
| 540 | uint32_t temp; |
| 541 | uint32_t hpos; |
| 542 | uint32_t lpos; |
| 543 | int report_id = 0; |
| 544 | |
| 545 | hpos = 0; |
| 546 | lpos = 0xFFFFFFFF; |
| 547 | |
| 548 | memset(&h, 0, sizeof h); |
| 549 | for (d = hid_start_parse(r, 1 << k, id); hid_get_item(d, &h); ) { |
| 550 | if (h.kind == k) { |
| 551 | /* compute minimum */ |
| 552 | if (lpos > h.pos) |
| 553 | lpos = h.pos; |
| 554 | /* compute end position */ |
| 555 | temp = h.pos + (h.report_size * h.report_count); |
| 556 | /* compute maximum */ |
| 557 | if (hpos < temp) |
| 558 | hpos = temp; |
| 559 | if (h.report_ID != 0) |
| 560 | report_id = 1; |
Value stored to 'report_id' is never read | |
| 561 | } |
| 562 | } |
| 563 | hid_end_parse(d); |
| 564 | |
| 565 | /* safety check - can happen in case of corrupt descriptors */ |
| 566 | if (lpos > hpos) |
| 567 | temp = 0; |
| 568 | else |
| 569 | temp = hpos - lpos; |
| 570 | |
| 571 | /* No extra byte for the reportID because the kernel skips it. */ |
| 572 | return ((temp + 7) / 8); |
| 573 | } |
| 574 | |
| 575 | int |
| 576 | hid_locate(report_desc_t desc, unsigned int u, enum hid_kind k, |
| 577 | hid_item_t *h, int id) |
| 578 | { |
| 579 | struct hid_data *d; |
| 580 | |
| 581 | for (d = hid_start_parse(desc, 1 << k, id); hid_get_item(d, h); ) { |
| 582 | if (h->kind == k && !(h->flags & HIO_CONST0x001) && h->usage == u) { |
| 583 | hid_end_parse(d); |
| 584 | return (1); |
| 585 | } |
| 586 | } |
| 587 | hid_end_parse(d); |
| 588 | h->report_size = 0; |
| 589 | return (0); |
| 590 | } |