1 /* $NetBSD: unvis.c,v 1.45 2022/04/19 20:32:15 rillig Exp $ */ 2 3 /*- 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: unvis.c,v 1.45 2022/04/19 20:32:15 rillig Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include <sys/types.h> 43 44 #include <assert.h> 45 #include <ctype.h> 46 #include <stdint.h> 47 #include <stdio.h> 48 #include <errno.h> 49 #include <vis.h> 50 51 #ifdef __weak_alias 52 __weak_alias(strnunvisx,_strnunvisx) 53 #endif 54 55 #if !HAVE_VIS 56 /* 57 * decode driven by state machine 58 */ 59 #define S_GROUND 0 /* haven't seen escape char */ 60 #define S_START 1 /* start decoding special sequence */ 61 #define S_META 2 /* metachar started (M) */ 62 #define S_META1 3 /* metachar more, regular char (-) */ 63 #define S_CTRL 4 /* control char started (^) */ 64 #define S_OCTAL2 5 /* octal digit 2 */ 65 #define S_OCTAL3 6 /* octal digit 3 */ 66 #define S_HEX 7 /* mandatory hex digit */ 67 #define S_HEX1 8 /* http hex digit */ 68 #define S_HEX2 9 /* http hex digit 2 */ 69 #define S_MIME1 10 /* mime hex digit 1 */ 70 #define S_MIME2 11 /* mime hex digit 2 */ 71 #define S_EATCRNL 12 /* mime eating CRNL */ 72 #define S_AMP 13 /* seen & */ 73 #define S_NUMBER 14 /* collecting number */ 74 #define S_STRING 15 /* collecting string */ 75 76 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 77 #define xtod(c) (isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10)) 78 #define XTOD(c) (isdigit(c) ? (c - '0') : ((c - 'A') + 10)) 79 80 /* 81 * RFC 1866 82 */ 83 static const struct nv { 84 char name[7]; 85 uint8_t value; 86 } nv[] = { 87 { "AElig", 198 }, /* capital AE diphthong (ligature) */ 88 { "Aacute", 193 }, /* capital A, acute accent */ 89 { "Acirc", 194 }, /* capital A, circumflex accent */ 90 { "Agrave", 192 }, /* capital A, grave accent */ 91 { "Aring", 197 }, /* capital A, ring */ 92 { "Atilde", 195 }, /* capital A, tilde */ 93 { "Auml", 196 }, /* capital A, dieresis or umlaut mark */ 94 { "Ccedil", 199 }, /* capital C, cedilla */ 95 { "ETH", 208 }, /* capital Eth, Icelandic */ 96 { "Eacute", 201 }, /* capital E, acute accent */ 97 { "Ecirc", 202 }, /* capital E, circumflex accent */ 98 { "Egrave", 200 }, /* capital E, grave accent */ 99 { "Euml", 203 }, /* capital E, dieresis or umlaut mark */ 100 { "Iacute", 205 }, /* capital I, acute accent */ 101 { "Icirc", 206 }, /* capital I, circumflex accent */ 102 { "Igrave", 204 }, /* capital I, grave accent */ 103 { "Iuml", 207 }, /* capital I, dieresis or umlaut mark */ 104 { "Ntilde", 209 }, /* capital N, tilde */ 105 { "Oacute", 211 }, /* capital O, acute accent */ 106 { "Ocirc", 212 }, /* capital O, circumflex accent */ 107 { "Ograve", 210 }, /* capital O, grave accent */ 108 { "Oslash", 216 }, /* capital O, slash */ 109 { "Otilde", 213 }, /* capital O, tilde */ 110 { "Ouml", 214 }, /* capital O, dieresis or umlaut mark */ 111 { "THORN", 222 }, /* capital THORN, Icelandic */ 112 { "Uacute", 218 }, /* capital U, acute accent */ 113 { "Ucirc", 219 }, /* capital U, circumflex accent */ 114 { "Ugrave", 217 }, /* capital U, grave accent */ 115 { "Uuml", 220 }, /* capital U, dieresis or umlaut mark */ 116 { "Yacute", 221 }, /* capital Y, acute accent */ 117 { "aacute", 225 }, /* small a, acute accent */ 118 { "acirc", 226 }, /* small a, circumflex accent */ 119 { "acute", 180 }, /* acute accent */ 120 { "aelig", 230 }, /* small ae diphthong (ligature) */ 121 { "agrave", 224 }, /* small a, grave accent */ 122 { "amp", 38 }, /* ampersand */ 123 { "aring", 229 }, /* small a, ring */ 124 { "atilde", 227 }, /* small a, tilde */ 125 { "auml", 228 }, /* small a, dieresis or umlaut mark */ 126 { "brvbar", 166 }, /* broken (vertical) bar */ 127 { "ccedil", 231 }, /* small c, cedilla */ 128 { "cedil", 184 }, /* cedilla */ 129 { "cent", 162 }, /* cent sign */ 130 { "copy", 169 }, /* copyright sign */ 131 { "curren", 164 }, /* general currency sign */ 132 { "deg", 176 }, /* degree sign */ 133 { "divide", 247 }, /* divide sign */ 134 { "eacute", 233 }, /* small e, acute accent */ 135 { "ecirc", 234 }, /* small e, circumflex accent */ 136 { "egrave", 232 }, /* small e, grave accent */ 137 { "eth", 240 }, /* small eth, Icelandic */ 138 { "euml", 235 }, /* small e, dieresis or umlaut mark */ 139 { "frac12", 189 }, /* fraction one-half */ 140 { "frac14", 188 }, /* fraction one-quarter */ 141 { "frac34", 190 }, /* fraction three-quarters */ 142 { "gt", 62 }, /* greater than */ 143 { "iacute", 237 }, /* small i, acute accent */ 144 { "icirc", 238 }, /* small i, circumflex accent */ 145 { "iexcl", 161 }, /* inverted exclamation mark */ 146 { "igrave", 236 }, /* small i, grave accent */ 147 { "iquest", 191 }, /* inverted question mark */ 148 { "iuml", 239 }, /* small i, dieresis or umlaut mark */ 149 { "laquo", 171 }, /* angle quotation mark, left */ 150 { "lt", 60 }, /* less than */ 151 { "macr", 175 }, /* macron */ 152 { "micro", 181 }, /* micro sign */ 153 { "middot", 183 }, /* middle dot */ 154 { "nbsp", 160 }, /* no-break space */ 155 { "not", 172 }, /* not sign */ 156 { "ntilde", 241 }, /* small n, tilde */ 157 { "oacute", 243 }, /* small o, acute accent */ 158 { "ocirc", 244 }, /* small o, circumflex accent */ 159 { "ograve", 242 }, /* small o, grave accent */ 160 { "ordf", 170 }, /* ordinal indicator, feminine */ 161 { "ordm", 186 }, /* ordinal indicator, masculine */ 162 { "oslash", 248 }, /* small o, slash */ 163 { "otilde", 245 }, /* small o, tilde */ 164 { "ouml", 246 }, /* small o, dieresis or umlaut mark */ 165 { "para", 182 }, /* pilcrow (paragraph sign) */ 166 { "plusmn", 177 }, /* plus-or-minus sign */ 167 { "pound", 163 }, /* pound sterling sign */ 168 { "quot", 34 }, /* double quote */ 169 { "raquo", 187 }, /* angle quotation mark, right */ 170 { "reg", 174 }, /* registered sign */ 171 { "sect", 167 }, /* section sign */ 172 { "shy", 173 }, /* soft hyphen */ 173 { "sup1", 185 }, /* superscript one */ 174 { "sup2", 178 }, /* superscript two */ 175 { "sup3", 179 }, /* superscript three */ 176 { "szlig", 223 }, /* small sharp s, German (sz ligature) */ 177 { "thorn", 254 }, /* small thorn, Icelandic */ 178 { "times", 215 }, /* multiply sign */ 179 { "uacute", 250 }, /* small u, acute accent */ 180 { "ucirc", 251 }, /* small u, circumflex accent */ 181 { "ugrave", 249 }, /* small u, grave accent */ 182 { "uml", 168 }, /* umlaut (dieresis) */ 183 { "uuml", 252 }, /* small u, dieresis or umlaut mark */ 184 { "yacute", 253 }, /* small y, acute accent */ 185 { "yen", 165 }, /* yen sign */ 186 { "yuml", 255 }, /* small y, dieresis or umlaut mark */ 187 }; 188 189 /* 190 * unvis - decode characters previously encoded by vis 191 */ 192 int 193 unvis(char *cp, int c, int *astate, int flag) 194 { 195 unsigned char uc = (unsigned char)c; 196 unsigned char st, ia, is, lc; 197 198 /* 199 * Bottom 8 bits of astate hold the state machine state. 200 * Top 8 bits hold the current character in the http 1866 nv string decoding 201 */ 202 #define GS(a) ((a) & 0xff) 203 #define SS(a, b) (((uint32_t)(a) << 24) | (b)) 204 #define GI(a) ((uint32_t)(a) >> 24) 205 206 _DIAGASSERT(cp != NULL); 207 _DIAGASSERT(astate != NULL); 208 st = GS(*astate); 209 210 if (flag & UNVIS_END) { 211 switch (st) { 212 case S_OCTAL2: 213 case S_OCTAL3: 214 case S_HEX2: 215 *astate = SS(0, S_GROUND); 216 return UNVIS_VALID; 217 case S_GROUND: 218 return UNVIS_NOCHAR; 219 default: 220 return UNVIS_SYNBAD; 221 } 222 } 223 224 switch (st) { 225 226 case S_GROUND: 227 *cp = 0; 228 if ((flag & VIS_NOESCAPE) == 0 && c == '\\') { 229 *astate = SS(0, S_START); 230 return UNVIS_NOCHAR; 231 } 232 if ((flag & VIS_HTTP1808) && c == '%') { 233 *astate = SS(0, S_HEX1); 234 return UNVIS_NOCHAR; 235 } 236 if ((flag & VIS_HTTP1866) && c == '&') { 237 *astate = SS(0, S_AMP); 238 return UNVIS_NOCHAR; 239 } 240 if ((flag & VIS_MIMESTYLE) && c == '=') { 241 *astate = SS(0, S_MIME1); 242 return UNVIS_NOCHAR; 243 } 244 *cp = c; 245 return UNVIS_VALID; 246 247 case S_START: 248 switch(c) { 249 case '\\': 250 *cp = c; 251 *astate = SS(0, S_GROUND); 252 return UNVIS_VALID; 253 case '0': case '1': case '2': case '3': 254 case '4': case '5': case '6': case '7': 255 *cp = (c - '0'); 256 *astate = SS(0, S_OCTAL2); 257 return UNVIS_NOCHAR; 258 case 'M': 259 *cp = (char)0200; 260 *astate = SS(0, S_META); 261 return UNVIS_NOCHAR; 262 case '^': 263 *astate = SS(0, S_CTRL); 264 return UNVIS_NOCHAR; 265 case 'n': 266 *cp = '\n'; 267 *astate = SS(0, S_GROUND); 268 return UNVIS_VALID; 269 case 'r': 270 *cp = '\r'; 271 *astate = SS(0, S_GROUND); 272 return UNVIS_VALID; 273 case 'b': 274 *cp = '\b'; 275 *astate = SS(0, S_GROUND); 276 return UNVIS_VALID; 277 case 'a': 278 *cp = '\007'; 279 *astate = SS(0, S_GROUND); 280 return UNVIS_VALID; 281 case 'v': 282 *cp = '\v'; 283 *astate = SS(0, S_GROUND); 284 return UNVIS_VALID; 285 case 't': 286 *cp = '\t'; 287 *astate = SS(0, S_GROUND); 288 return UNVIS_VALID; 289 case 'f': 290 *cp = '\f'; 291 *astate = SS(0, S_GROUND); 292 return UNVIS_VALID; 293 case 's': 294 *cp = ' '; 295 *astate = SS(0, S_GROUND); 296 return UNVIS_VALID; 297 case 'E': 298 *cp = '\033'; 299 *astate = SS(0, S_GROUND); 300 return UNVIS_VALID; 301 case 'x': 302 *astate = SS(0, S_HEX); 303 return UNVIS_NOCHAR; 304 case '\n': 305 /* 306 * hidden newline 307 */ 308 *astate = SS(0, S_GROUND); 309 return UNVIS_NOCHAR; 310 case '$': 311 /* 312 * hidden marker 313 */ 314 *astate = SS(0, S_GROUND); 315 return UNVIS_NOCHAR; 316 default: 317 if (isgraph(c)) { 318 *cp = c; 319 *astate = SS(0, S_GROUND); 320 return UNVIS_VALID; 321 } 322 } 323 goto bad; 324 325 case S_META: 326 if (c == '-') 327 *astate = SS(0, S_META1); 328 else if (c == '^') 329 *astate = SS(0, S_CTRL); 330 else 331 goto bad; 332 return UNVIS_NOCHAR; 333 334 case S_META1: 335 *astate = SS(0, S_GROUND); 336 *cp |= c; 337 return UNVIS_VALID; 338 339 case S_CTRL: 340 if (c == '?') 341 *cp |= 0177; 342 else 343 *cp |= c & 037; 344 *astate = SS(0, S_GROUND); 345 return UNVIS_VALID; 346 347 case S_OCTAL2: /* second possible octal digit */ 348 if (isoctal(uc)) { 349 /* 350 * yes - and maybe a third 351 */ 352 *cp = (*cp << 3) + (c - '0'); 353 *astate = SS(0, S_OCTAL3); 354 return UNVIS_NOCHAR; 355 } 356 /* 357 * no - done with current sequence, push back passed char 358 */ 359 *astate = SS(0, S_GROUND); 360 return UNVIS_VALIDPUSH; 361 362 case S_OCTAL3: /* third possible octal digit */ 363 *astate = SS(0, S_GROUND); 364 if (isoctal(uc)) { 365 *cp = (*cp << 3) + (c - '0'); 366 return UNVIS_VALID; 367 } 368 /* 369 * we were done, push back passed char 370 */ 371 return UNVIS_VALIDPUSH; 372 373 case S_HEX: 374 if (!isxdigit(uc)) 375 goto bad; 376 /*FALLTHROUGH*/ 377 case S_HEX1: 378 if (isxdigit(uc)) { 379 *cp = xtod(uc); 380 *astate = SS(0, S_HEX2); 381 return UNVIS_NOCHAR; 382 } 383 /* 384 * no - done with current sequence, push back passed char 385 */ 386 *astate = SS(0, S_GROUND); 387 return UNVIS_VALIDPUSH; 388 389 case S_HEX2: 390 *astate = S_GROUND; 391 if (isxdigit(uc)) { 392 *cp = xtod(uc) | (*cp << 4); 393 return UNVIS_VALID; 394 } 395 return UNVIS_VALIDPUSH; 396 397 case S_MIME1: 398 if (uc == '\n' || uc == '\r') { 399 *astate = SS(0, S_EATCRNL); 400 return UNVIS_NOCHAR; 401 } 402 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 403 *cp = XTOD(uc); 404 *astate = SS(0, S_MIME2); 405 return UNVIS_NOCHAR; 406 } 407 goto bad; 408 409 case S_MIME2: 410 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 411 *astate = SS(0, S_GROUND); 412 *cp = XTOD(uc) | (*cp << 4); 413 return UNVIS_VALID; 414 } 415 goto bad; 416 417 case S_EATCRNL: 418 switch (uc) { 419 case '\r': 420 case '\n': 421 return UNVIS_NOCHAR; 422 case '=': 423 *astate = SS(0, S_MIME1); 424 return UNVIS_NOCHAR; 425 default: 426 *cp = uc; 427 *astate = SS(0, S_GROUND); 428 return UNVIS_VALID; 429 } 430 431 case S_AMP: 432 *cp = 0; 433 if (uc == '#') { 434 *astate = SS(0, S_NUMBER); 435 return UNVIS_NOCHAR; 436 } 437 *astate = SS(0, S_STRING); 438 /*FALLTHROUGH*/ 439 440 case S_STRING: 441 ia = *cp; /* index in the array */ 442 is = GI(*astate); /* index in the string */ 443 lc = is == 0 ? 0 : nv[ia].name[is - 1]; /* last character */ 444 445 if (uc == ';') 446 uc = '\0'; 447 448 for (; ia < __arraycount(nv); ia++) { 449 if (is != 0 && nv[ia].name[is - 1] != lc) 450 goto bad; 451 if (nv[ia].name[is] == uc) 452 break; 453 } 454 455 if (ia == __arraycount(nv)) 456 goto bad; 457 458 if (uc != 0) { 459 *cp = ia; 460 *astate = SS(is + 1, S_STRING); 461 return UNVIS_NOCHAR; 462 } 463 464 *cp = nv[ia].value; 465 *astate = SS(0, S_GROUND); 466 return UNVIS_VALID; 467 468 case S_NUMBER: 469 if (uc == ';') 470 return UNVIS_VALID; 471 if (!isdigit(uc)) 472 goto bad; 473 *cp += (*cp * 10) + uc - '0'; 474 return UNVIS_NOCHAR; 475 476 default: 477 bad: 478 /* 479 * decoder in unknown state - (probably uninitialized) 480 */ 481 *astate = SS(0, S_GROUND); 482 return UNVIS_SYNBAD; 483 } 484 } 485 486 /* 487 * strnunvisx - decode src into dst 488 * 489 * Number of chars decoded into dst is returned, -1 on error. 490 * Dst is null terminated. 491 */ 492 493 int 494 strnunvisx(char *dst, size_t dlen, const char *src, int flag) 495 { 496 char c; 497 char t = '\0', *start = dst; 498 int state = 0; 499 500 _DIAGASSERT(src != NULL); 501 _DIAGASSERT(dst != NULL); 502 #define CHECKSPACE() \ 503 do { \ 504 if (dlen-- == 0) { \ 505 errno = ENOSPC; \ 506 return -1; \ 507 } \ 508 } while (0) 509 510 while ((c = *src++) != '\0') { 511 again: 512 switch (unvis(&t, c, &state, flag)) { 513 case UNVIS_VALID: 514 CHECKSPACE(); 515 *dst++ = t; 516 break; 517 case UNVIS_VALIDPUSH: 518 CHECKSPACE(); 519 *dst++ = t; 520 goto again; 521 case 0: 522 case UNVIS_NOCHAR: 523 break; 524 case UNVIS_SYNBAD: 525 errno = EINVAL; 526 return -1; 527 default: 528 _DIAGASSERT(/*CONSTCOND*/0); 529 errno = EINVAL; 530 return -1; 531 } 532 } 533 if (unvis(&t, c, &state, UNVIS_END) == UNVIS_VALID) { 534 CHECKSPACE(); 535 *dst++ = t; 536 } 537 CHECKSPACE(); 538 *dst = '\0'; 539 return (int)(dst - start); 540 } 541 542 int 543 strunvisx(char *dst, const char *src, int flag) 544 { 545 return strnunvisx(dst, (size_t)~0, src, flag); 546 } 547 548 int 549 strunvis(char *dst, const char *src) 550 { 551 return strnunvisx(dst, (size_t)~0, src, 0); 552 } 553 554 int 555 strnunvis(char *dst, size_t dlen, const char *src) 556 { 557 return strnunvisx(dst, dlen, src, 0); 558 } 559 #endif 560
Indexes created Sat Sep 20 22:09:52 GMT 2025