unvis.c revision 248302
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 <sys/cdefs.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 $"); 38#endif 39#endif /* LIBC_SCCS and not lint */ 40__FBSDID("$FreeBSD: head/contrib/libc-vis/unvis.c 248302 2013-03-14 23:51:47Z brooks $"); 41 42#include "namespace.h" 43#include <sys/types.h> 44 45#include <assert.h> 46#include <ctype.h> 47#include <stdint.h> 48#include <stdio.h> 49#include <errno.h> 50#include <vis.h> 51 52#define _DIAGASSERT(x) assert(x) 53 54/* 55 * Return the number of elements in a statically-allocated array, 56 * __x. 57 */ 58#define __arraycount(__x) (sizeof(__x) / sizeof(__x[0])) 59 60#ifdef __weak_alias 61__weak_alias(strnunvisx,_strnunvisx) 62#endif 63 64#if !HAVE_VIS 65/* 66 * decode driven by state machine 67 */ 68#define S_GROUND 0 /* haven't seen escape char */ 69#define S_START 1 /* start decoding special sequence */ 70#define S_META 2 /* metachar started (M) */ 71#define S_META1 3 /* metachar more, regular char (-) */ 72#define S_CTRL 4 /* control char started (^) */ 73#define S_OCTAL2 5 /* octal digit 2 */ 74#define S_OCTAL3 6 /* octal digit 3 */ 75#define S_HEX 7 /* mandatory hex digit */ 76#define S_HEX1 8 /* http hex digit */ 77#define S_HEX2 9 /* http hex digit 2 */ 78#define S_MIME1 10 /* mime hex digit 1 */ 79#define S_MIME2 11 /* mime hex digit 2 */ 80#define S_EATCRNL 12 /* mime eating CRNL */ 81#define S_AMP 13 /* seen & */ 82#define S_NUMBER 14 /* collecting number */ 83#define S_STRING 15 /* collecting string */ 84 85#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 86#define xtod(c) (isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10)) 87#define XTOD(c) (isdigit(c) ? (c - '0') : ((c - 'A') + 10)) 88 89/* 90 * RFC 1866 91 */ 92static const struct nv { 93 char name[7]; 94 uint8_t value; 95} nv[] = { 96 { "AElig", 198 }, /* capital AE diphthong (ligature) */ 97 { "Aacute", 193 }, /* capital A, acute accent */ 98 { "Acirc", 194 }, /* capital A, circumflex accent */ 99 { "Agrave", 192 }, /* capital A, grave accent */ 100 { "Aring", 197 }, /* capital A, ring */ 101 { "Atilde", 195 }, /* capital A, tilde */ 102 { "Auml", 196 }, /* capital A, dieresis or umlaut mark */ 103 { "Ccedil", 199 }, /* capital C, cedilla */ 104 { "ETH", 208 }, /* capital Eth, Icelandic */ 105 { "Eacute", 201 }, /* capital E, acute accent */ 106 { "Ecirc", 202 }, /* capital E, circumflex accent */ 107 { "Egrave", 200 }, /* capital E, grave accent */ 108 { "Euml", 203 }, /* capital E, dieresis or umlaut mark */ 109 { "Iacute", 205 }, /* capital I, acute accent */ 110 { "Icirc", 206 }, /* capital I, circumflex accent */ 111 { "Igrave", 204 }, /* capital I, grave accent */ 112 { "Iuml", 207 }, /* capital I, dieresis or umlaut mark */ 113 { "Ntilde", 209 }, /* capital N, tilde */ 114 { "Oacute", 211 }, /* capital O, acute accent */ 115 { "Ocirc", 212 }, /* capital O, circumflex accent */ 116 { "Ograve", 210 }, /* capital O, grave accent */ 117 { "Oslash", 216 }, /* capital O, slash */ 118 { "Otilde", 213 }, /* capital O, tilde */ 119 { "Ouml", 214 }, /* capital O, dieresis or umlaut mark */ 120 { "THORN", 222 }, /* capital THORN, Icelandic */ 121 { "Uacute", 218 }, /* capital U, acute accent */ 122 { "Ucirc", 219 }, /* capital U, circumflex accent */ 123 { "Ugrave", 217 }, /* capital U, grave accent */ 124 { "Uuml", 220 }, /* capital U, dieresis or umlaut mark */ 125 { "Yacute", 221 }, /* capital Y, acute accent */ 126 { "aacute", 225 }, /* small a, acute accent */ 127 { "acirc", 226 }, /* small a, circumflex accent */ 128 { "acute", 180 }, /* acute accent */ 129 { "aelig", 230 }, /* small ae diphthong (ligature) */ 130 { "agrave", 224 }, /* small a, grave accent */ 131 { "amp", 38 }, /* ampersand */ 132 { "aring", 229 }, /* small a, ring */ 133 { "atilde", 227 }, /* small a, tilde */ 134 { "auml", 228 }, /* small a, dieresis or umlaut mark */ 135 { "brvbar", 166 }, /* broken (vertical) bar */ 136 { "ccedil", 231 }, /* small c, cedilla */ 137 { "cedil", 184 }, /* cedilla */ 138 { "cent", 162 }, /* cent sign */ 139 { "copy", 169 }, /* copyright sign */ 140 { "curren", 164 }, /* general currency sign */ 141 { "deg", 176 }, /* degree sign */ 142 { "divide", 247 }, /* divide sign */ 143 { "eacute", 233 }, /* small e, acute accent */ 144 { "ecirc", 234 }, /* small e, circumflex accent */ 145 { "egrave", 232 }, /* small e, grave accent */ 146 { "eth", 240 }, /* small eth, Icelandic */ 147 { "euml", 235 }, /* small e, dieresis or umlaut mark */ 148 { "frac12", 189 }, /* fraction one-half */ 149 { "frac14", 188 }, /* fraction one-quarter */ 150 { "frac34", 190 }, /* fraction three-quarters */ 151 { "gt", 62 }, /* greater than */ 152 { "iacute", 237 }, /* small i, acute accent */ 153 { "icirc", 238 }, /* small i, circumflex accent */ 154 { "iexcl", 161 }, /* inverted exclamation mark */ 155 { "igrave", 236 }, /* small i, grave accent */ 156 { "iquest", 191 }, /* inverted question mark */ 157 { "iuml", 239 }, /* small i, dieresis or umlaut mark */ 158 { "laquo", 171 }, /* angle quotation mark, left */ 159 { "lt", 60 }, /* less than */ 160 { "macr", 175 }, /* macron */ 161 { "micro", 181 }, /* micro sign */ 162 { "middot", 183 }, /* middle dot */ 163 { "nbsp", 160 }, /* no-break space */ 164 { "not", 172 }, /* not sign */ 165 { "ntilde", 241 }, /* small n, tilde */ 166 { "oacute", 243 }, /* small o, acute accent */ 167 { "ocirc", 244 }, /* small o, circumflex accent */ 168 { "ograve", 242 }, /* small o, grave accent */ 169 { "ordf", 170 }, /* ordinal indicator, feminine */ 170 { "ordm", 186 }, /* ordinal indicator, masculine */ 171 { "oslash", 248 }, /* small o, slash */ 172 { "otilde", 245 }, /* small o, tilde */ 173 { "ouml", 246 }, /* small o, dieresis or umlaut mark */ 174 { "para", 182 }, /* pilcrow (paragraph sign) */ 175 { "plusmn", 177 }, /* plus-or-minus sign */ 176 { "pound", 163 }, /* pound sterling sign */ 177 { "quot", 34 }, /* double quote */ 178 { "raquo", 187 }, /* angle quotation mark, right */ 179 { "reg", 174 }, /* registered sign */ 180 { "sect", 167 }, /* section sign */ 181 { "shy", 173 }, /* soft hyphen */ 182 { "sup1", 185 }, /* superscript one */ 183 { "sup2", 178 }, /* superscript two */ 184 { "sup3", 179 }, /* superscript three */ 185 { "szlig", 223 }, /* small sharp s, German (sz ligature) */ 186 { "thorn", 254 }, /* small thorn, Icelandic */ 187 { "times", 215 }, /* multiply sign */ 188 { "uacute", 250 }, /* small u, acute accent */ 189 { "ucirc", 251 }, /* small u, circumflex accent */ 190 { "ugrave", 249 }, /* small u, grave accent */ 191 { "uml", 168 }, /* umlaut (dieresis) */ 192 { "uuml", 252 }, /* small u, dieresis or umlaut mark */ 193 { "yacute", 253 }, /* small y, acute accent */ 194 { "yen", 165 }, /* yen sign */ 195 { "yuml", 255 }, /* small y, dieresis or umlaut mark */ 196}; 197 198/* 199 * unvis - decode characters previously encoded by vis 200 */ 201int 202unvis(char *cp, int c, int *astate, int flag) 203{ 204 unsigned char uc = (unsigned char)c; 205 unsigned char st, ia, is, lc; 206 207/* 208 * Bottom 8 bits of astate hold the state machine state. 209 * Top 8 bits hold the current character in the http 1866 nv string decoding 210 */ 211#define GS(a) ((a) & 0xff) 212#define SS(a, b) (((uint32_t)(a) << 24) | (b)) 213#define GI(a) ((uint32_t)(a) >> 24) 214 215 _DIAGASSERT(cp != NULL); 216 _DIAGASSERT(astate != NULL); 217 st = GS(*astate); 218 219 if (flag & UNVIS_END) { 220 switch (st) { 221 case S_OCTAL2: 222 case S_OCTAL3: 223 case S_HEX2: 224 *astate = SS(0, S_GROUND); 225 return UNVIS_VALID; 226 case S_GROUND: 227 return UNVIS_NOCHAR; 228 default: 229 return UNVIS_SYNBAD; 230 } 231 } 232 233 switch (st) { 234 235 case S_GROUND: 236 *cp = 0; 237 if ((flag & VIS_NOESCAPE) == 0 && c == '\\') { 238 *astate = SS(0, S_START); 239 return UNVIS_NOCHAR; 240 } 241 if ((flag & VIS_HTTP1808) && c == '%') { 242 *astate = SS(0, S_HEX1); 243 return UNVIS_NOCHAR; 244 } 245 if ((flag & VIS_HTTP1866) && c == '&') { 246 *astate = SS(0, S_AMP); 247 return UNVIS_NOCHAR; 248 } 249 if ((flag & VIS_MIMESTYLE) && c == '=') { 250 *astate = SS(0, S_MIME1); 251 return UNVIS_NOCHAR; 252 } 253 *cp = c; 254 return UNVIS_VALID; 255 256 case S_START: 257 switch(c) { 258 case '\\': 259 *cp = c; 260 *astate = SS(0, S_GROUND); 261 return UNVIS_VALID; 262 case '0': case '1': case '2': case '3': 263 case '4': case '5': case '6': case '7': 264 *cp = (c - '0'); 265 *astate = SS(0, S_OCTAL2); 266 return UNVIS_NOCHAR; 267 case 'M': 268 *cp = (char)0200; 269 *astate = SS(0, S_META); 270 return UNVIS_NOCHAR; 271 case '^': 272 *astate = SS(0, S_CTRL); 273 return UNVIS_NOCHAR; 274 case 'n': 275 *cp = '\n'; 276 *astate = SS(0, S_GROUND); 277 return UNVIS_VALID; 278 case 'r': 279 *cp = '\r'; 280 *astate = SS(0, S_GROUND); 281 return UNVIS_VALID; 282 case 'b': 283 *cp = '\b'; 284 *astate = SS(0, S_GROUND); 285 return UNVIS_VALID; 286 case 'a': 287 *cp = '\007'; 288 *astate = SS(0, S_GROUND); 289 return UNVIS_VALID; 290 case 'v': 291 *cp = '\v'; 292 *astate = SS(0, S_GROUND); 293 return UNVIS_VALID; 294 case 't': 295 *cp = '\t'; 296 *astate = SS(0, S_GROUND); 297 return UNVIS_VALID; 298 case 'f': 299 *cp = '\f'; 300 *astate = SS(0, S_GROUND); 301 return UNVIS_VALID; 302 case 's': 303 *cp = ' '; 304 *astate = SS(0, S_GROUND); 305 return UNVIS_VALID; 306 case 'E': 307 *cp = '\033'; 308 *astate = SS(0, S_GROUND); 309 return UNVIS_VALID; 310 case 'x': 311 *astate = SS(0, S_HEX); 312 return UNVIS_NOCHAR; 313 case '\n': 314 /* 315 * hidden newline 316 */ 317 *astate = SS(0, S_GROUND); 318 return UNVIS_NOCHAR; 319 case '$': 320 /* 321 * hidden marker 322 */ 323 *astate = SS(0, S_GROUND); 324 return UNVIS_NOCHAR; 325 } 326 goto bad; 327 328 case S_META: 329 if (c == '-') 330 *astate = SS(0, S_META1); 331 else if (c == '^') 332 *astate = SS(0, S_CTRL); 333 else 334 goto bad; 335 return UNVIS_NOCHAR; 336 337 case S_META1: 338 *astate = SS(0, S_GROUND); 339 *cp |= c; 340 return UNVIS_VALID; 341 342 case S_CTRL: 343 if (c == '?') 344 *cp |= 0177; 345 else 346 *cp |= c & 037; 347 *astate = SS(0, S_GROUND); 348 return UNVIS_VALID; 349 350 case S_OCTAL2: /* second possible octal digit */ 351 if (isoctal(uc)) { 352 /* 353 * yes - and maybe a third 354 */ 355 *cp = (*cp << 3) + (c - '0'); 356 *astate = SS(0, S_OCTAL3); 357 return UNVIS_NOCHAR; 358 } 359 /* 360 * no - done with current sequence, push back passed char 361 */ 362 *astate = SS(0, S_GROUND); 363 return UNVIS_VALIDPUSH; 364 365 case S_OCTAL3: /* third possible octal digit */ 366 *astate = SS(0, S_GROUND); 367 if (isoctal(uc)) { 368 *cp = (*cp << 3) + (c - '0'); 369 return UNVIS_VALID; 370 } 371 /* 372 * we were done, push back passed char 373 */ 374 return UNVIS_VALIDPUSH; 375 376 case S_HEX: 377 if (!isxdigit(uc)) 378 goto bad; 379 /*FALLTHROUGH*/ 380 case S_HEX1: 381 if (isxdigit(uc)) { 382 *cp = xtod(uc); 383 *astate = SS(0, S_HEX2); 384 return UNVIS_NOCHAR; 385 } 386 /* 387 * no - done with current sequence, push back passed char 388 */ 389 *astate = SS(0, S_GROUND); 390 return UNVIS_VALIDPUSH; 391 392 case S_HEX2: 393 *astate = S_GROUND; 394 if (isxdigit(uc)) { 395 *cp = xtod(uc) | (*cp << 4); 396 return UNVIS_VALID; 397 } 398 return UNVIS_VALIDPUSH; 399 400 case S_MIME1: 401 if (uc == '\n' || uc == '\r') { 402 *astate = SS(0, S_EATCRNL); 403 return UNVIS_NOCHAR; 404 } 405 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 406 *cp = XTOD(uc); 407 *astate = SS(0, S_MIME2); 408 return UNVIS_NOCHAR; 409 } 410 goto bad; 411 412 case S_MIME2: 413 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 414 *astate = SS(0, S_GROUND); 415 *cp = XTOD(uc) | (*cp << 4); 416 return UNVIS_VALID; 417 } 418 goto bad; 419 420 case S_EATCRNL: 421 switch (uc) { 422 case '\r': 423 case '\n': 424 return UNVIS_NOCHAR; 425 case '=': 426 *astate = SS(0, S_MIME1); 427 return UNVIS_NOCHAR; 428 default: 429 *cp = uc; 430 *astate = SS(0, S_GROUND); 431 return UNVIS_VALID; 432 } 433 434 case S_AMP: 435 *cp = 0; 436 if (uc == '#') { 437 *astate = SS(0, S_NUMBER); 438 return UNVIS_NOCHAR; 439 } 440 *astate = SS(0, S_STRING); 441 /*FALLTHROUGH*/ 442 443 case S_STRING: 444 ia = *cp; /* index in the array */ 445 is = GI(*astate); /* index in the string */ 446 lc = is == 0 ? 0 : nv[ia].name[is - 1]; /* last character */ 447 448 if (uc == ';') 449 uc = '\0'; 450 451 for (; ia < __arraycount(nv); ia++) { 452 if (is != 0 && nv[ia].name[is - 1] != lc) 453 goto bad; 454 if (nv[ia].name[is] == uc) 455 break; 456 } 457 458 if (ia == __arraycount(nv)) 459 goto bad; 460 461 if (uc != 0) { 462 *cp = ia; 463 *astate = SS(is + 1, S_STRING); 464 return UNVIS_NOCHAR; 465 } 466 467 *cp = nv[ia].value; 468 *astate = SS(0, S_GROUND); 469 return UNVIS_VALID; 470 471 case S_NUMBER: 472 if (uc == ';') 473 return UNVIS_VALID; 474 if (!isdigit(uc)) 475 goto bad; 476 *cp += (*cp * 10) + uc - '0'; 477 return UNVIS_NOCHAR; 478 479 default: 480 bad: 481 /* 482 * decoder in unknown state - (probably uninitialized) 483 */ 484 *astate = SS(0, S_GROUND); 485 return UNVIS_SYNBAD; 486 } 487} 488 489/* 490 * strnunvisx - decode src into dst 491 * 492 * Number of chars decoded into dst is returned, -1 on error. 493 * Dst is null terminated. 494 */ 495 496int 497strnunvisx(char *dst, size_t dlen, const char *src, int flag) 498{ 499 char c; 500 char t = '\0', *start = dst; 501 int state = 0; 502 503 _DIAGASSERT(src != NULL); 504 _DIAGASSERT(dst != NULL); 505#define CHECKSPACE() \ 506 do { \ 507 if (dlen-- == 0) { \ 508 errno = ENOSPC; \ 509 return -1; \ 510 } \ 511 } while (/*CONSTCOND*/0) 512 513 while ((c = *src++) != '\0') { 514 again: 515 switch (unvis(&t, c, &state, flag)) { 516 case UNVIS_VALID: 517 CHECKSPACE(); 518 *dst++ = t; 519 break; 520 case UNVIS_VALIDPUSH: 521 CHECKSPACE(); 522 *dst++ = t; 523 goto again; 524 case 0: 525 case UNVIS_NOCHAR: 526 break; 527 case UNVIS_SYNBAD: 528 errno = EINVAL; 529 return -1; 530 default: 531 _DIAGASSERT(/*CONSTCOND*/0); 532 errno = EINVAL; 533 return -1; 534 } 535 } 536 if (unvis(&t, c, &state, UNVIS_END) == UNVIS_VALID) { 537 CHECKSPACE(); 538 *dst++ = t; 539 } 540 CHECKSPACE(); 541 *dst = '\0'; 542 return (int)(dst - start); 543} 544 545int 546strunvisx(char *dst, const char *src, int flag) 547{ 548 return strnunvisx(dst, (size_t)~0, src, flag); 549} 550 551int 552strunvis(char *dst, const char *src) 553{ 554 return strnunvisx(dst, (size_t)~0, src, 0); 555} 556 557int 558strnunvis(char *dst, size_t dlen, const char *src) 559{ 560 return strnunvisx(dst, dlen, src, 0); 561} 562#endif 563