lib/libc/gen/unvis.c

   1 /*      $NetBSD: unvis.c,v 1.32 2010/11/27 21:22:11 christos 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 1.32 2010/11/27 21:22:11 christos 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 <stdio.h>
  47 #include <vis.h>
  48
  49 #ifdef __weak_alias
  50 __weak_alias(strunvis,_strunvis)
  51 #endif
  52
  53 #if !HAVE_VIS
  54 /*
  55  * decode driven by state machine
  56  */
  57 #define S_GROUND        0       /* haven't seen escape char */
  58 #define S_START         1       /* start decoding special sequence */
  59 #define S_META          2       /* metachar started (M) */
  60 #define S_META1         3       /* metachar more, regular char (-) */
  61 #define S_CTRL          4       /* control char started (^) */
  62 #define S_OCTAL2        5       /* octal digit 2 */
  63 #define S_OCTAL3        6       /* octal digit 3 */
  64 #define S_HEX1          7       /* http hex digit */
  65 #define S_HEX2          8       /* http hex digit 2 */
  66 #define S_MIME1         9       /* mime hex digit 1 */
  67 #define S_MIME2         10      /* mime hex digit 2 */
  68 #define S_EATCRNL       11      /* mime eating CRNL */
  69 #define S_AMP           12      /* seen & */
  70 #define S_NUMBER        13      /* collecting number */
  71 #define S_STRING        14      /* collecting string */
  72
  73 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  74 #define xtod(c)         (isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10))
  75 #define XTOD(c)         (isdigit(c) ? (c - '0') : ((c - 'A') + 10))
  76
  77 /*
  78  * RFC 1866
  79  */
  80 static const struct nv {
  81         const char *name;
  82         uint8_t value;
  83 } nv[] = {
  84         { "AElig",      198 }, /* capital AE diphthong (ligature)  */
  85         { "Aacute",     193 }, /* capital A, acute accent  */
  86         { "Acirc",      194 }, /* capital A, circumflex accent  */
  87         { "Agrave",     192 }, /* capital A, grave accent  */
  88         { "Aring",      197 }, /* capital A, ring  */
  89         { "Atilde",     195 }, /* capital A, tilde  */
  90         { "Auml",       196 }, /* capital A, dieresis or umlaut mark  */
  91         { "Ccedil",     199 }, /* capital C, cedilla  */
  92         { "ETH",        208 }, /* capital Eth, Icelandic  */
  93         { "Eacute",     201 }, /* capital E, acute accent  */
  94         { "Ecirc",      202 }, /* capital E, circumflex accent  */
  95         { "Egrave",     200 }, /* capital E, grave accent  */
  96         { "Euml",       203 }, /* capital E, dieresis or umlaut mark  */
  97         { "Iacute",     205 }, /* capital I, acute accent  */
  98         { "Icirc",      206 }, /* capital I, circumflex accent  */
  99         { "Igrave",     204 }, /* capital I, grave accent  */
 100         { "Iuml",       207 }, /* capital I, dieresis or umlaut mark  */
 101         { "Ntilde",     209 }, /* capital N, tilde  */
 102         { "Oacute",     211 }, /* capital O, acute accent  */
 103         { "Ocirc",      212 }, /* capital O, circumflex accent  */
 104         { "Ograve",     210 }, /* capital O, grave accent  */
 105         { "Oslash",     216 }, /* capital O, slash  */
 106         { "Otilde",     213 }, /* capital O, tilde  */
 107         { "Ouml",       214 }, /* capital O, dieresis or umlaut mark  */
 108         { "THORN",      222 }, /* capital THORN, Icelandic  */
 109         { "Uacute",     218 }, /* capital U, acute accent  */
 110         { "Ucirc",      219 }, /* capital U, circumflex accent  */
 111         { "Ugrave",     217 }, /* capital U, grave accent  */
 112         { "Uuml",       220 }, /* capital U, dieresis or umlaut mark  */
 113         { "Yacute",     221 }, /* capital Y, acute accent  */
 114         { "aacute",     225 }, /* small a, acute accent  */
 115         { "acirc",      226 }, /* small a, circumflex accent  */
 116         { "acute",      180 }, /* acute accent  */
 117         { "aelig",      230 }, /* small ae diphthong (ligature)  */
 118         { "agrave",     224 }, /* small a, grave accent  */
 119         { "amp",         38 }, /* ampersand  */
 120         { "aring",      229 }, /* small a, ring  */
 121         { "atilde",     227 }, /* small a, tilde  */
 122         { "auml",       228 }, /* small a, dieresis or umlaut mark  */
 123         { "brvbar",     166 }, /* broken (vertical) bar  */
 124         { "ccedil",     231 }, /* small c, cedilla  */
 125         { "cedil",      184 }, /* cedilla  */
 126         { "cent",       162 }, /* cent sign  */
 127         { "copy",       169 }, /* copyright sign  */
 128         { "curren",     164 }, /* general currency sign  */
 129         { "deg",        176 }, /* degree sign  */
 130         { "divide",     247 }, /* divide sign  */
 131         { "eacute",     233 }, /* small e, acute accent  */
 132         { "ecirc",      234 }, /* small e, circumflex accent  */
 133         { "egrave",     232 }, /* small e, grave accent  */
 134         { "eth",        240 }, /* small eth, Icelandic  */
 135         { "euml",       235 }, /* small e, dieresis or umlaut mark  */
 136         { "frac12",     189 }, /* fraction one-half  */
 137         { "frac14",     188 }, /* fraction one-quarter  */
 138         { "frac34",     190 }, /* fraction three-quarters  */
 139         { "gt",          62 }, /* greater than  */
 140         { "iacute",     237 }, /* small i, acute accent  */
 141         { "icirc",      238 }, /* small i, circumflex accent  */
 142         { "iexcl",      161 }, /* inverted exclamation mark  */
 143         { "igrave",     236 }, /* small i, grave accent  */
 144         { "iquest",     191 }, /* inverted question mark  */
 145         { "iuml",       239 }, /* small i, dieresis or umlaut mark  */
 146         { "laquo",      171 }, /* angle quotation mark, left  */
 147         { "lt",          60 }, /* less than  */
 148         { "macr",       175 }, /* macron  */
 149         { "micro",      181 }, /* micro sign  */
 150         { "middot",     183 }, /* middle dot  */
 151         { "nbsp",       160 }, /* no-break space  */
 152         { "not",        172 }, /* not sign  */
 153         { "ntilde",     241 }, /* small n, tilde  */
 154         { "oacute",     243 }, /* small o, acute accent  */
 155         { "ocirc",      244 }, /* small o, circumflex accent  */
 156         { "ograve",     242 }, /* small o, grave accent  */
 157         { "ordf",       170 }, /* ordinal indicator, feminine  */
 158         { "ordm",       186 }, /* ordinal indicator, masculine  */
 159         { "oslash",     248 }, /* small o, slash  */
 160         { "otilde",     245 }, /* small o, tilde  */
 161         { "ouml",       246 }, /* small o, dieresis or umlaut mark  */
 162         { "para",       182 }, /* pilcrow (paragraph sign)  */
 163         { "plusmn",     177 }, /* plus-or-minus sign  */
 164         { "pound",      163 }, /* pound sterling sign  */
 165         { "quot",        34 }, /* double quote  */
 166         { "raquo",      187 }, /* angle quotation mark, right  */
 167         { "reg",        174 }, /* registered sign  */
 168         { "sect",       167 }, /* section sign  */
 169         { "shy",        173 }, /* soft hyphen  */
 170         { "sup1",       185 }, /* superscript one  */
 171         { "sup2",       178 }, /* superscript two  */
 172         { "sup3",       179 }, /* superscript three  */
 173         { "szlig",      223 }, /* small sharp s, German (sz ligature)  */
 174         { "thorn",      254 }, /* small thorn, Icelandic  */
 175         { "times",      215 }, /* multiply sign  */
 176         { "uacute",     250 }, /* small u, acute accent  */
 177         { "ucirc",      251 }, /* small u, circumflex accent  */
 178         { "ugrave",     249 }, /* small u, grave accent  */
 179         { "uml",        168 }, /* umlaut (dieresis)  */
 180         { "uuml",       252 }, /* small u, dieresis or umlaut mark  */
 181         { "yacute",     253 }, /* small y, acute accent  */
 182         { "yen",        165 }, /* yen sign  */
 183         { "yuml",       255 }, /* small y, dieresis or umlaut mark  */
 184 };
 185
 186 /*
 187  * unvis - decode characters previously encoded by vis
 188  */
 189 int
 190 unvis(char *cp, int c, int *astate, int flag)
 191 {
 192         unsigned char uc = (unsigned char)c;
 193         unsigned char st, ia, is, lc;
 194
 195 /*
 196  * Bottom 8 bits of astate hold the state machine state.
 197  * Top 8 bits hold the current character in the http 1866 nv string decoding
 198  */
 199 #define GS(a)           ((a) & 0xff)
 200 #define SS(a, b)        (((uint32_t)(a) << 24) | (b))
 201 #define GI(a)           ((uint32_t)(a) >> 24)
 202
 203         _DIAGASSERT(cp != NULL);
 204         _DIAGASSERT(astate != NULL);
 205         st = GS(*astate);
 206
 207         if (flag & UNVIS_END) {
 208                 switch (st) {
 209                 case S_OCTAL2:
 210                 case S_OCTAL3:
 211                 case S_HEX2:
 212                         *astate = SS(0, S_GROUND);
 213                         return UNVIS_VALID;
 214                 case S_GROUND:
 215                         return UNVIS_NOCHAR;
 216                 default:
 217                         return UNVIS_SYNBAD;
 218                 }
 219         }
 220
 221         switch (st) {
 222
 223         case S_GROUND:
 224                 *cp = 0;
 225                 if ((flag & VIS_NOESCAPE) == 0 && c == '\\') {
 226                         *astate = SS(0, S_START);
 227                         return UNVIS_NOCHAR;
 228                 }
 229                 if ((flag & VIS_HTTP1808) && c == '%') {
 230                         *astate = SS(0, S_HEX1);
 231                         return UNVIS_NOCHAR;
 232                 }
 233                 if ((flag & VIS_HTTP1866) && c == '&') {
 234                         *astate = SS(0, S_AMP);
 235                         return UNVIS_NOCHAR;
 236                 }
 237                 if ((flag & VIS_MIMESTYLE) && c == '=') {
 238                         *astate = SS(0, S_MIME1);
 239                         return UNVIS_NOCHAR;
 240                 }
 241                 *cp = c;
 242                 return UNVIS_VALID;
 243
 244         case S_START:
 245                 switch(c) {
 246                 case '\\':
 247                         *cp = c;
 248                         *astate = SS(0, S_GROUND);
 249                         return UNVIS_VALID;
 250                 case '0': case '1': case '2': case '3':
 251                 case '4': case '5': case '6': case '7':
 252                         *cp = (c - '0');
 253                         *astate = SS(0, S_OCTAL2);
 254                         return UNVIS_NOCHAR;
 255                 case 'M':
 256                         *cp = (char)0200;
 257                         *astate = SS(0, S_META);
 258                         return UNVIS_NOCHAR;
 259                 case '^':
 260                         *astate = SS(0, S_CTRL);
 261                         return UNVIS_NOCHAR;
 262                 case 'n':
 263                         *cp = '\n';
 264                         *astate = SS(0, S_GROUND);
 265                         return UNVIS_VALID;
 266                 case 'r':
 267                         *cp = '\r';
 268                         *astate = SS(0, S_GROUND);
 269                         return UNVIS_VALID;
 270                 case 'b':
 271                         *cp = '\b';
 272                         *astate = SS(0, S_GROUND);
 273                         return UNVIS_VALID;
 274                 case 'a':
 275                         *cp = '\007';
 276                         *astate = SS(0, S_GROUND);
 277                         return UNVIS_VALID;
 278                 case 'v':
 279                         *cp = '\v';
 280                         *astate = SS(0, S_GROUND);
 281                         return UNVIS_VALID;
 282                 case 't':
 283                         *cp = '\t';
 284                         *astate = SS(0, S_GROUND);
 285                         return UNVIS_VALID;
 286                 case 'f':
 287                         *cp = '\f';
 288                         *astate = SS(0, S_GROUND);
 289                         return UNVIS_VALID;
 290                 case 's':
 291                         *cp = ' ';
 292                         *astate = SS(0, S_GROUND);
 293                         return UNVIS_VALID;
 294                 case 'E':
 295                         *cp = '\033';
 296                         *astate = SS(0, S_GROUND);
 297                         return UNVIS_VALID;
 298                 case '\n':
 299                         /*
 300                          * hidden newline
 301                          */
 302                         *astate = SS(0, S_GROUND);
 303                         return UNVIS_NOCHAR;
 304                 case '$':
 305                         /*
 306                          * hidden marker
 307                          */
 308                         *astate = SS(0, S_GROUND);
 309                         return UNVIS_NOCHAR;
 310                 }
 311                 goto bad;
 312
 313         case S_META:
 314                 if (c == '-')
 315                         *astate = SS(0, S_META1);
 316                 else if (c == '^')
 317                         *astate = SS(0, S_CTRL);
 318                 else
 319                         goto bad;
 320                 return UNVIS_NOCHAR;
 321
 322         case S_META1:
 323                 *astate = SS(0, S_GROUND);
 324                 *cp |= c;
 325                 return UNVIS_VALID;
 326
 327         case S_CTRL:
 328                 if (c == '?')
 329                         *cp |= 0177;
 330                 else
 331                         *cp |= c & 037;
 332                 *astate = SS(0, S_GROUND);
 333                 return UNVIS_VALID;
 334
 335         case S_OCTAL2:  /* second possible octal digit */
 336                 if (isoctal(uc)) {
 337                         /*
 338                          * yes - and maybe a third
 339                          */
 340                         *cp = (*cp << 3) + (c - '0');
 341                         *astate = SS(0, S_OCTAL3);
 342                         return UNVIS_NOCHAR;
 343                 }
 344                 /*
 345                  * no - done with current sequence, push back passed char
 346                  */
 347                 *astate = SS(0, S_GROUND);
 348                 return UNVIS_VALIDPUSH;
 349
 350         case S_OCTAL3:  /* third possible octal digit */
 351                 *astate = SS(0, S_GROUND);
 352                 if (isoctal(uc)) {
 353                         *cp = (*cp << 3) + (c - '0');
 354                         return UNVIS_VALID;
 355                 }
 356                 /*
 357                  * we were done, push back passed char
 358                  */
 359                 return UNVIS_VALIDPUSH;
 360
 361         case S_HEX1:
 362                 if (isxdigit(uc)) {
 363                         *cp = xtod(uc);
 364                         *astate = SS(0, S_HEX2);
 365                         return UNVIS_NOCHAR;
 366                 }
 367                 /*
 368                  * no - done with current sequence, push back passed char
 369                  */
 370                 *astate = SS(0, S_GROUND);
 371                 return UNVIS_VALIDPUSH;
 372
 373         case S_HEX2:
 374                 *astate = S_GROUND;
 375                 if (isxdigit(uc)) {
 376                         *cp = xtod(uc) | (*cp << 4);
 377                         return UNVIS_VALID;
 378                 }
 379                 return UNVIS_VALIDPUSH;
 380
 381         case S_MIME1:
 382                 if (uc == '\n' || uc == '\r') {
 383                         *astate = SS(0, S_EATCRNL);
 384                         return UNVIS_NOCHAR;
 385                 }
 386                 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) {
 387                         *cp = XTOD(uc);
 388                         *astate = SS(0, S_MIME2);
 389                         return UNVIS_NOCHAR;
 390                 }
 391                 goto bad;
 392
 393         case S_MIME2:
 394                 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) {
 395                         *astate = SS(0, S_GROUND);
 396                         *cp = XTOD(uc) | (*cp << 4);
 397                         return UNVIS_VALID;
 398                 }
 399                 goto bad;
 400
 401         case S_EATCRNL:
 402                 switch (uc) {
 403                 case '\r':
 404                 case '\n':
 405                         return UNVIS_NOCHAR;
 406                 case '=':
 407                         *astate = SS(0, S_MIME1);
 408                         return UNVIS_NOCHAR;
 409                 default:
 410                         *cp = uc;
 411                         *astate = SS(0, S_GROUND);
 412                         return UNVIS_VALID;
 413                 }
 414
 415         case S_AMP:
 416                 *cp = 0;
 417                 if (uc == '#') {
 418                         *astate = SS(0, S_NUMBER);
 419                         return UNVIS_NOCHAR;
 420                 }
 421                 *astate = SS(0, S_STRING);
 422                 /*FALLTHROUGH*/
 423
 424         case S_STRING:
 425                 ia = *cp;               /* index in the array */
 426                 is = GI(*astate);       /* index in the string */
 427                 lc = is == 0 ? 0 : nv[ia].name[is - 1]; /* last character */
 428
 429                 if (uc == ';')
 430                         uc = '\0';
 431
 432                 for (; ia < __arraycount(nv); ia++) {
 433                         if (is != 0 && nv[ia].name[is - 1] != lc)
 434                                 goto bad;
 435                         if (nv[ia].name[is] == uc)
 436                                 break;
 437                 }
 438
 439                 if (*cp == __arraycount(nv))
 440                         goto bad;
 441
 442                 if (uc != 0) {
 443                         *cp = ia;
 444                         *astate = SS(is + 1, S_STRING);
 445                         return UNVIS_NOCHAR;
 446                 }
 447
 448                 *cp = nv[ia].value;
 449                 *astate = SS(0, S_GROUND);
 450                 return UNVIS_VALID;
 451
 452         case S_NUMBER:
 453                 if (uc == ';')
 454                         return UNVIS_VALID;
 455                 if (!isdigit(uc))
 456                         goto bad;
 457                 *cp += (*cp * 10) + uc - '0';
 458                 return UNVIS_NOCHAR;
 459
 460         default:
 461         bad:
 462                 /*
 463                  * decoder in unknown state - (probably uninitialized)
 464                  */
 465                 *astate = SS(0, S_GROUND);
 466                 return UNVIS_SYNBAD;
 467         }
 468 }
 469
 470 /*
 471  * strunvis - decode src into dst
 472  *
 473  *      Number of chars decoded into dst is returned, -1 on error.
 474  *      Dst is null terminated.
 475  */
 476
 477 int
 478 strunvisx(char *dst, const char *src, int flag)
 479 {
 480         char c;
 481         char *start = dst;
 482         int state = 0;
 483
 484         _DIAGASSERT(src != NULL);
 485         _DIAGASSERT(dst != NULL);
 486
 487         while ((c = *src++) != '\0') {
 488  again:
 489                 switch (unvis(dst, c, &state, flag)) {
 490                 case UNVIS_VALID:
 491                         dst++;
 492                         break;
 493                 case UNVIS_VALIDPUSH:
 494                         dst++;
 495                         goto again;
 496                 case 0:
 497                 case UNVIS_NOCHAR:
 498                         break;
 499                 default:
 500                         return (-1);
 501                 }
 502         }
 503         if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
 504                 dst++;
 505         *dst = '\0';
 506         return (int)(dst - start);
 507 }
 508
 509 int
 510 strunvis(char *dst, const char *src)
 511 {
 512         return strunvisx(dst, src, 0);
 513 }
 514 #endif