1/* $NetBSD: unvis.c,v 1.41 2012/12/15 04:29:53 matt 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 "config.h" 33#if defined(LIBC_SCCS) && !defined(lint) 34#if 0 35static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93"; 36#else 37__RCSID("$NetBSD: unvis.c,v 1.41 2012/12/15 04:29:53 matt Exp $"); 38#endif 39#endif /* LIBC_SCCS and not lint */ 40 41#include <sys/types.h> 42 43#include <assert.h> 44#include <ctype.h> 45#ifdef HAVE_STDINT_H 46#include <stdint.h> 47#endif 48#include <stdio.h> 49#include <errno.h> 50#include <vis.h> 51 52#ifdef __weak_alias 53__weak_alias(strnunvisx,_strnunvisx) 54#endif 55 56#if !HAVE_VIS 57/* 58 * decode driven by state machine 59 */ 60#define S_GROUND 0 /* haven't seen escape char */ 61#define S_START 1 /* start decoding special sequence */ 62#define S_META 2 /* metachar started (M) */ 63#define S_META1 3 /* metachar more, regular char (-) */ 64#define S_CTRL 4 /* control char started (^) */ 65#define S_OCTAL2 5 /* octal digit 2 */ 66#define S_OCTAL3 6 /* octal digit 3 */ 67#define S_HEX 7 /* mandatory hex digit */ 68#define S_HEX1 8 /* http hex digit */ 69#define S_HEX2 9 /* http hex digit 2 */ 70#define S_MIME1 10 /* mime hex digit 1 */ 71#define S_MIME2 11 /* mime hex digit 2 */ 72#define S_EATCRNL 12 /* mime eating CRNL */ 73#define S_AMP 13 /* seen & */ 74#define S_NUMBER 14 /* collecting number */ 75#define S_STRING 15 /* collecting string */ 76 77#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 78#define xtod(c) (isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10)) 79#define XTOD(c) (isdigit(c) ? (c - '0') : ((c - 'A') + 10)) 80 81/* 82 * RFC 1866 83 */ 84static const struct nv { 85 char name[7]; 86 uint8_t value; 87} nv[] = { 88 { "AElig", 198 }, /* capital AE diphthong (ligature) */ 89 { "Aacute", 193 }, /* capital A, acute accent */ 90 { "Acirc", 194 }, /* capital A, circumflex accent */ 91 { "Agrave", 192 }, /* capital A, grave accent */ 92 { "Aring", 197 }, /* capital A, ring */ 93 { "Atilde", 195 }, /* capital A, tilde */ 94 { "Auml", 196 }, /* capital A, dieresis or umlaut mark */ 95 { "Ccedil", 199 }, /* capital C, cedilla */ 96 { "ETH", 208 }, /* capital Eth, Icelandic */ 97 { "Eacute", 201 }, /* capital E, acute accent */ 98 { "Ecirc", 202 }, /* capital E, circumflex accent */ 99 { "Egrave", 200 }, /* capital E, grave accent */ 100 { "Euml", 203 }, /* capital E, dieresis or umlaut mark */ 101 { "Iacute", 205 }, /* capital I, acute accent */ 102 { "Icirc", 206 }, /* capital I, circumflex accent */ 103 { "Igrave", 204 }, /* capital I, grave accent */ 104 { "Iuml", 207 }, /* capital I, dieresis or umlaut mark */ 105 { "Ntilde", 209 }, /* capital N, tilde */ 106 { "Oacute", 211 }, /* capital O, acute accent */ 107 { "Ocirc", 212 }, /* capital O, circumflex accent */ 108 { "Ograve", 210 }, /* capital O, grave accent */ 109 { "Oslash", 216 }, /* capital O, slash */ 110 { "Otilde", 213 }, /* capital O, tilde */ 111 { "Ouml", 214 }, /* capital O, dieresis or umlaut mark */ 112 { "THORN", 222 }, /* capital THORN, Icelandic */ 113 { "Uacute", 218 }, /* capital U, acute accent */ 114 { "Ucirc", 219 }, /* capital U, circumflex accent */ 115 { "Ugrave", 217 }, /* capital U, grave accent */ 116 { "Uuml", 220 }, /* capital U, dieresis or umlaut mark */ 117 { "Yacute", 221 }, /* capital Y, acute accent */ 118 { "aacute", 225 }, /* small a, acute accent */ 119 { "acirc", 226 }, /* small a, circumflex accent */ 120 { "acute", 180 }, /* acute accent */ 121 { "aelig", 230 }, /* small ae diphthong (ligature) */ 122 { "agrave", 224 }, /* small a, grave accent */ 123 { "amp", 38 }, /* ampersand */ 124 { "aring", 229 }, /* small a, ring */ 125 { "atilde", 227 }, /* small a, tilde */ 126 { "auml", 228 }, /* small a, dieresis or umlaut mark */ 127 { "brvbar", 166 }, /* broken (vertical) bar */ 128 { "ccedil", 231 }, /* small c, cedilla */ 129 { "cedil", 184 }, /* cedilla */ 130 { "cent", 162 }, /* cent sign */ 131 { "copy", 169 }, /* copyright sign */ 132 { "curren", 164 }, /* general currency sign */ 133 { "deg", 176 }, /* degree sign */ 134 { "divide", 247 }, /* divide sign */ 135 { "eacute", 233 }, /* small e, acute accent */ 136 { "ecirc", 234 }, /* small e, circumflex accent */ 137 { "egrave", 232 }, /* small e, grave accent */ 138 { "eth", 240 }, /* small eth, Icelandic */ 139 { "euml", 235 }, /* small e, dieresis or umlaut mark */ 140 { "frac12", 189 }, /* fraction one-half */ 141 { "frac14", 188 }, /* fraction one-quarter */ 142 { "frac34", 190 }, /* fraction three-quarters */ 143 { "gt", 62 }, /* greater than */ 144 { "iacute", 237 }, /* small i, acute accent */ 145 { "icirc", 238 }, /* small i, circumflex accent */ 146 { "iexcl", 161 }, /* inverted exclamation mark */ 147 { "igrave", 236 }, /* small i, grave accent */ 148 { "iquest", 191 }, /* inverted question mark */ 149 { "iuml", 239 }, /* small i, dieresis or umlaut mark */ 150 { "laquo", 171 }, /* angle quotation mark, left */ 151 { "lt", 60 }, /* less than */ 152 { "macr", 175 }, /* macron */ 153 { "micro", 181 }, /* micro sign */ 154 { "middot", 183 }, /* middle dot */ 155 { "nbsp", 160 }, /* no-break space */ 156 { "not", 172 }, /* not sign */ 157 { "ntilde", 241 }, /* small n, tilde */ 158 { "oacute", 243 }, /* small o, acute accent */ 159 { "ocirc", 244 }, /* small o, circumflex accent */ 160 { "ograve", 242 }, /* small o, grave accent */ 161 { "ordf", 170 }, /* ordinal indicator, feminine */ 162 { "ordm", 186 }, /* ordinal indicator, masculine */ 163 { "oslash", 248 }, /* small o, slash */ 164 { "otilde", 245 }, /* small o, tilde */ 165 { "ouml", 246 }, /* small o, dieresis or umlaut mark */ 166 { "para", 182 }, /* pilcrow (paragraph sign) */ 167 { "plusmn", 177 }, /* plus-or-minus sign */ 168 { "pound", 163 }, /* pound sterling sign */ 169 { "quot", 34 }, /* double quote */ 170 { "raquo", 187 }, /* angle quotation mark, right */ 171 { "reg", 174 }, /* registered sign */ 172 { "sect", 167 }, /* section sign */ 173 { "shy", 173 }, /* soft hyphen */ 174 { "sup1", 185 }, /* superscript one */ 175 { "sup2", 178 }, /* superscript two */ 176 { "sup3", 179 }, /* superscript three */ 177 { "szlig", 223 }, /* small sharp s, German (sz ligature) */ 178 { "thorn", 254 }, /* small thorn, Icelandic */ 179 { "times", 215 }, /* multiply sign */ 180 { "uacute", 250 }, /* small u, acute accent */ 181 { "ucirc", 251 }, /* small u, circumflex accent */ 182 { "ugrave", 249 }, /* small u, grave accent */ 183 { "uml", 168 }, /* umlaut (dieresis) */ 184 { "uuml", 252 }, /* small u, dieresis or umlaut mark */ 185 { "yacute", 253 }, /* small y, acute accent */ 186 { "yen", 165 }, /* yen sign */ 187 { "yuml", 255 }, /* small y, dieresis or umlaut mark */ 188}; 189 190/* 191 * unvis - decode characters previously encoded by vis 192 */ 193int 194unvis(char *cp, int c, int *astate, int flag) 195{ 196 unsigned char uc = (unsigned char)c; 197 unsigned char st, ia, is, lc; 198 199/* 200 * Bottom 8 bits of astate hold the state machine state. 201 * Top 8 bits hold the current character in the http 1866 nv string decoding 202 */ 203#define GS(a) ((a) & 0xff) 204#define SS(a, b) (((uint32_t)(a) << 24) | (b)) 205#define GI(a) ((uint32_t)(a) >> 24) 206 207 _DIAGASSERT(cp != NULL); 208 _DIAGASSERT(astate != NULL); 209 st = GS(*astate); 210 211 if (flag & UNVIS_END) { 212 switch (st) { 213 case S_OCTAL2: 214 case S_OCTAL3: 215 case S_HEX2: 216 *astate = SS(0, S_GROUND); 217 return UNVIS_VALID; 218 case S_GROUND: 219 return UNVIS_NOCHAR; 220 default: 221 return UNVIS_SYNBAD; 222 } 223 } 224 225 switch (st) { 226 227 case S_GROUND: 228 *cp = 0; 229 if ((flag & VIS_NOESCAPE) == 0 && c == '\\') { 230 *astate = SS(0, S_START); 231 return UNVIS_NOCHAR; 232 } 233 if ((flag & VIS_HTTP1808) && c == '%') { 234 *astate = SS(0, S_HEX1); 235 return UNVIS_NOCHAR; 236 } 237 if ((flag & VIS_HTTP1866) && c == '&') { 238 *astate = SS(0, S_AMP); 239 return UNVIS_NOCHAR; 240 } 241 if ((flag & VIS_MIMESTYLE) && c == '=') { 242 *astate = SS(0, S_MIME1); 243 return UNVIS_NOCHAR; 244 } 245 *cp = c; 246 return UNVIS_VALID; 247 248 case S_START: 249 switch(c) { 250 case '\\': 251 *cp = c; 252 *astate = SS(0, S_GROUND); 253 return UNVIS_VALID; 254 case '0': case '1': case '2': case '3': 255 case '4': case '5': case '6': case '7': 256 *cp = (c - '0'); 257 *astate = SS(0, S_OCTAL2); 258 return UNVIS_NOCHAR; 259 case 'M': 260 *cp = (char)0200; 261 *astate = SS(0, S_META); 262 return UNVIS_NOCHAR; 263 case '^': 264 *astate = SS(0, S_CTRL); 265 return UNVIS_NOCHAR; 266 case 'n': 267 *cp = '\n'; 268 *astate = SS(0, S_GROUND); 269 return UNVIS_VALID; 270 case 'r': 271 *cp = '\r'; 272 *astate = SS(0, S_GROUND); 273 return UNVIS_VALID; 274 case 'b': 275 *cp = '\b'; 276 *astate = SS(0, S_GROUND); 277 return UNVIS_VALID; 278 case 'a': 279 *cp = '\007'; 280 *astate = SS(0, S_GROUND); 281 return UNVIS_VALID; 282 case 'v': 283 *cp = '\v'; 284 *astate = SS(0, S_GROUND); 285 return UNVIS_VALID; 286 case 't': 287 *cp = '\t'; 288 *astate = SS(0, S_GROUND); 289 return UNVIS_VALID; 290 case 'f': 291 *cp = '\f'; 292 *astate = SS(0, S_GROUND); 293 return UNVIS_VALID; 294 case 's': 295 *cp = ' '; 296 *astate = SS(0, S_GROUND); 297 return UNVIS_VALID; 298 case 'E': 299 *cp = '\033'; 300 *astate = SS(0, S_GROUND); 301 return UNVIS_VALID; 302 case 'x': 303 *astate = SS(0, S_HEX); 304 return UNVIS_NOCHAR; 305 case '\n': 306 /* 307 * hidden newline 308 */ 309 *astate = SS(0, S_GROUND); 310 return UNVIS_NOCHAR; 311 case '$': 312 /* 313 * hidden marker 314 */ 315 *astate = SS(0, S_GROUND); 316 return UNVIS_NOCHAR; 317 } 318 goto bad; 319 320 case S_META: 321 if (c == '-') 322 *astate = SS(0, S_META1); 323 else if (c == '^') 324 *astate = SS(0, S_CTRL); 325 else 326 goto bad; 327 return UNVIS_NOCHAR; 328 329 case S_META1: 330 *astate = SS(0, S_GROUND); 331 *cp |= c; 332 return UNVIS_VALID; 333 334 case S_CTRL: 335 if (c == '?') 336 *cp |= 0177; 337 else 338 *cp |= c & 037; 339 *astate = SS(0, S_GROUND); 340 return UNVIS_VALID; 341 342 case S_OCTAL2: /* second possible octal digit */ 343 if (isoctal(uc)) { 344 /* 345 * yes - and maybe a third 346 */ 347 *cp = (*cp << 3) + (c - '0'); 348 *astate = SS(0, S_OCTAL3); 349 return UNVIS_NOCHAR; 350 } 351 /* 352 * no - done with current sequence, push back passed char 353 */ 354 *astate = SS(0, S_GROUND); 355 return UNVIS_VALIDPUSH; 356 357 case S_OCTAL3: /* third possible octal digit */ 358 *astate = SS(0, S_GROUND); 359 if (isoctal(uc)) { 360 *cp = (*cp << 3) + (c - '0'); 361 return UNVIS_VALID; 362 } 363 /* 364 * we were done, push back passed char 365 */ 366 return UNVIS_VALIDPUSH; 367 368 case S_HEX: 369 if (!isxdigit(uc)) 370 goto bad; 371 /*FALLTHROUGH*/ 372 case S_HEX1: 373 if (isxdigit(uc)) { 374 *cp = xtod(uc); 375 *astate = SS(0, S_HEX2); 376 return UNVIS_NOCHAR; 377 } 378 /* 379 * no - done with current sequence, push back passed char 380 */ 381 *astate = SS(0, S_GROUND); 382 return UNVIS_VALIDPUSH; 383 384 case S_HEX2: 385 *astate = S_GROUND; 386 if (isxdigit(uc)) { 387 *cp = xtod(uc) | (*cp << 4); 388 return UNVIS_VALID; 389 } 390 return UNVIS_VALIDPUSH; 391 392 case S_MIME1: 393 if (uc == '\n' || uc == '\r') { 394 *astate = SS(0, S_EATCRNL); 395 return UNVIS_NOCHAR; 396 } 397 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 398 *cp = XTOD(uc); 399 *astate = SS(0, S_MIME2); 400 return UNVIS_NOCHAR; 401 } 402 goto bad; 403 404 case S_MIME2: 405 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 406 *astate = SS(0, S_GROUND); 407 *cp = XTOD(uc) | (*cp << 4); 408 return UNVIS_VALID; 409 } 410 goto bad; 411 412 case S_EATCRNL: 413 switch (uc) { 414 case '\r': 415 case '\n': 416 return UNVIS_NOCHAR; 417 case '=': 418 *astate = SS(0, S_MIME1); 419 return UNVIS_NOCHAR; 420 default: 421 *cp = uc; 422 *astate = SS(0, S_GROUND); 423 return UNVIS_VALID; 424 } 425 426 case S_AMP: 427 *cp = 0; 428 if (uc == '#') { 429 *astate = SS(0, S_NUMBER); 430 return UNVIS_NOCHAR; 431 } 432 *astate = SS(0, S_STRING); 433 /*FALLTHROUGH*/ 434 435 case S_STRING: 436 ia = *cp; /* index in the array */ 437 is = GI(*astate); /* index in the string */ 438 lc = is == 0 ? 0 : nv[ia].name[is - 1]; /* last character */ 439 440 if (uc == ';') 441 uc = '\0'; 442 443 for (; ia < __arraycount(nv); ia++) { 444 if (is != 0 && nv[ia].name[is - 1] != lc) 445 goto bad; 446 if (nv[ia].name[is] == uc) 447 break; 448 } 449 450 if (ia == __arraycount(nv)) 451 goto bad; 452 453 if (uc != 0) { 454 *cp = ia; 455 *astate = SS(is + 1, S_STRING); 456 return UNVIS_NOCHAR; 457 } 458 459 *cp = nv[ia].value; 460 *astate = SS(0, S_GROUND); 461 return UNVIS_VALID; 462 463 case S_NUMBER: 464 if (uc == ';') 465 return UNVIS_VALID; 466 if (!isdigit(uc)) 467 goto bad; 468 *cp += (*cp * 10) + uc - '0'; 469 return UNVIS_NOCHAR; 470 471 default: 472 bad: 473 /* 474 * decoder in unknown state - (probably uninitialized) 475 */ 476 *astate = SS(0, S_GROUND); 477 return UNVIS_SYNBAD; 478 } 479} 480 481/* 482 * strnunvisx - decode src into dst 483 * 484 * Number of chars decoded into dst is returned, -1 on error. 485 * Dst is null terminated. 486 */ 487 488int 489strnunvisx(char *dst, size_t dlen, const char *src, int flag) 490{ 491 char c; 492 char t = '\0', *start = dst; 493 int state = 0; 494 495 _DIAGASSERT(src != NULL); 496 _DIAGASSERT(dst != NULL); 497#define CHECKSPACE() \ 498 do { \ 499 if (dlen-- == 0) { \ 500 errno = ENOSPC; \ 501 return -1; \ 502 } \ 503 } while (/*CONSTCOND*/0) 504 505 while ((c = *src++) != '\0') { 506 again: 507 switch (unvis(&t, c, &state, flag)) { 508 case UNVIS_VALID: 509 CHECKSPACE(); 510 *dst++ = t; 511 break; 512 case UNVIS_VALIDPUSH: 513 CHECKSPACE(); 514 *dst++ = t; 515 goto again; 516 case 0: 517 case UNVIS_NOCHAR: 518 break; 519 case UNVIS_SYNBAD: 520 errno = EINVAL; 521 return -1; 522 default: 523 _DIAGASSERT(/*CONSTCOND*/0); 524 errno = EINVAL; 525 return -1; 526 } 527 } 528 if (unvis(&t, c, &state, UNVIS_END) == UNVIS_VALID) { 529 CHECKSPACE(); 530 *dst++ = t; 531 } 532 CHECKSPACE(); 533 *dst = '\0'; 534 return (int)(dst - start); 535} 536 537int 538strunvisx(char *dst, const char *src, int flag) 539{ 540 return strnunvisx(dst, (size_t)~0, src, flag); 541} 542 543int 544strunvis(char *dst, const char *src) 545{ 546 return strnunvisx(dst, (size_t)~0, src, 0); 547} 548 549int 550strnunvis(char *dst, size_t dlen, const char *src) 551{ 552 return strnunvisx(dst, dlen, src, 0); 553} 554#endif 555