lib/libc/gen/unvis.c

   1 /*      $NetBSD: unvis.c,v 1.44 2014/09/26 15:43:36 roy 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 1.44 2014/09/26 15:43:36 roy 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 (/*CONSTCOND*/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