unvis.c revision 1.29
1 /* $NetBSD: unvis.c,v 1.29 2009/02/10 23:06:31 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 1.29 2009/02/10 23:06:31 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 70 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 71 #define xtod(c) (isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10)) 72 #define XTOD(c) (isdigit(c) ? (c - '0') : ((c - 'A') + 10)) 73 74 /* 75 * unvis - decode characters previously encoded by vis 76 */ 77 int 78 unvis(char *cp, int c, int *astate, int flag) 79 { 80 unsigned char uc = (unsigned char)c; 81 82 _DIAGASSERT(cp != NULL); 83 _DIAGASSERT(astate != NULL); 84 85 if (flag & UNVIS_END) { 86 if (*astate == S_OCTAL2 || *astate == S_OCTAL3 87 || *astate == S_HEX2) { 88 *astate = S_GROUND; 89 return UNVIS_VALID; 90 } 91 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 92 } 93 94 switch (*astate) { 95 96 case S_GROUND: 97 *cp = 0; 98 if (c == '\\') { 99 *astate = S_START; 100 return UNVIS_NOCHAR; 101 } 102 if ((flag & VIS_HTTPSTYLE) && c == '%') { 103 *astate = S_HEX1; 104 return UNVIS_NOCHAR; 105 } 106 if ((flag & VIS_MIMESTYLE) && c == '=') { 107 *astate = S_MIME1; 108 return UNVIS_NOCHAR; 109 } 110 *cp = c; 111 return UNVIS_VALID; 112 113 case S_START: 114 switch(c) { 115 case '\\': 116 *cp = c; 117 *astate = S_GROUND; 118 return UNVIS_VALID; 119 case '0': case '1': case '2': case '3': 120 case '4': case '5': case '6': case '7': 121 *cp = (c - '0'); 122 *astate = S_OCTAL2; 123 return UNVIS_NOCHAR; 124 case 'M': 125 *cp = (char)0200; 126 *astate = S_META; 127 return UNVIS_NOCHAR; 128 case '^': 129 *astate = S_CTRL; 130 return UNVIS_NOCHAR; 131 case 'n': 132 *cp = '\n'; 133 *astate = S_GROUND; 134 return UNVIS_VALID; 135 case 'r': 136 *cp = '\r'; 137 *astate = S_GROUND; 138 return UNVIS_VALID; 139 case 'b': 140 *cp = '\b'; 141 *astate = S_GROUND; 142 return UNVIS_VALID; 143 case 'a': 144 *cp = '\007'; 145 *astate = S_GROUND; 146 return UNVIS_VALID; 147 case 'v': 148 *cp = '\v'; 149 *astate = S_GROUND; 150 return UNVIS_VALID; 151 case 't': 152 *cp = '\t'; 153 *astate = S_GROUND; 154 return UNVIS_VALID; 155 case 'f': 156 *cp = '\f'; 157 *astate = S_GROUND; 158 return UNVIS_VALID; 159 case 's': 160 *cp = ' '; 161 *astate = S_GROUND; 162 return UNVIS_VALID; 163 case 'E': 164 *cp = '\033'; 165 *astate = S_GROUND; 166 return UNVIS_VALID; 167 case '\n': 168 /* 169 * hidden newline 170 */ 171 *astate = S_GROUND; 172 return (UNVIS_NOCHAR); 173 case '$': 174 /* 175 * hidden marker 176 */ 177 *astate = S_GROUND; 178 return (UNVIS_NOCHAR); 179 } 180 *astate = S_GROUND; 181 return (UNVIS_SYNBAD); 182 183 case S_META: 184 if (c == '-') 185 *astate = S_META1; 186 else if (c == '^') 187 *astate = S_CTRL; 188 else { 189 *astate = S_GROUND; 190 return (UNVIS_SYNBAD); 191 } 192 return UNVIS_NOCHAR; 193 194 case S_META1: 195 *astate = S_GROUND; 196 *cp |= c; 197 return UNVIS_VALID; 198 199 case S_CTRL: 200 if (c == '?') 201 *cp |= 0177; 202 else 203 *cp |= c & 037; 204 *astate = S_GROUND; 205 return UNVIS_VALID; 206 207 case S_OCTAL2: /* second possible octal digit */ 208 if (isoctal(uc)) { 209 /* 210 * yes - and maybe a third 211 */ 212 *cp = (*cp << 3) + (c - '0'); 213 *astate = S_OCTAL3; 214 return UNVIS_NOCHAR; 215 } 216 /* 217 * no - done with current sequence, push back passed char 218 */ 219 *astate = S_GROUND; 220 return UNVIS_VALIDPUSH; 221 222 case S_OCTAL3: /* third possible octal digit */ 223 *astate = S_GROUND; 224 if (isoctal(uc)) { 225 *cp = (*cp << 3) + (c - '0'); 226 return UNVIS_VALID; 227 } 228 /* 229 * we were done, push back passed char 230 */ 231 return UNVIS_VALIDPUSH; 232 233 case S_HEX1: 234 if (isxdigit(uc)) { 235 *cp = xtod(uc); 236 *astate = S_HEX2; 237 return UNVIS_NOCHAR; 238 } 239 /* 240 * no - done with current sequence, push back passed char 241 */ 242 *astate = S_GROUND; 243 return UNVIS_VALIDPUSH; 244 245 case S_HEX2: 246 *astate = S_GROUND; 247 if (isxdigit(uc)) { 248 *cp = xtod(uc) | (*cp << 4); 249 return UNVIS_VALID; 250 } 251 return UNVIS_VALIDPUSH; 252 253 case S_MIME1: 254 if (uc == '\n' || uc == '\r') { 255 *astate = S_EATCRNL; 256 return UNVIS_NOCHAR; 257 } 258 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 259 *cp = XTOD(uc); 260 *astate = S_MIME2; 261 return UNVIS_NOCHAR; 262 } 263 fprintf(stderr, "Bad hex digit1 %c\n", uc); 264 *astate = S_GROUND; 265 return UNVIS_SYNBAD; 266 267 case S_MIME2: 268 if (isxdigit(uc) && (isdigit(uc) || isupper(uc))) { 269 *astate = S_GROUND; 270 *cp = XTOD(uc) | (*cp << 4); 271 return UNVIS_VALID; 272 } 273 fprintf(stderr, "Bad hex digit2 %c\n", uc); 274 *astate = S_GROUND; 275 return UNVIS_SYNBAD; 276 277 case S_EATCRNL: 278 switch (uc) { 279 case '\r': 280 case '\n': 281 return UNVIS_NOCHAR; 282 case '=': 283 *astate = S_MIME1; 284 return UNVIS_NOCHAR; 285 default: 286 *cp = uc; 287 return UNVIS_VALID; 288 } 289 290 default: 291 /* 292 * decoder in unknown state - (probably uninitialized) 293 */ 294 *astate = S_GROUND; 295 return UNVIS_SYNBAD; 296 } 297 } 298 299 /* 300 * strunvis - decode src into dst 301 * 302 * Number of chars decoded into dst is returned, -1 on error. 303 * Dst is null terminated. 304 */ 305 306 int 307 strunvisx(dst, src, flag) 308 char *dst; 309 const char *src; 310 int flag; 311 { 312 char c; 313 char *start = dst; 314 int state = 0; 315 316 _DIAGASSERT(src != NULL); 317 _DIAGASSERT(dst != NULL); 318 319 while ((c = *src++) != '\0') { 320 again: 321 switch (unvis(dst, c, &state, flag)) { 322 case UNVIS_VALID: 323 dst++; 324 break; 325 case UNVIS_VALIDPUSH: 326 dst++; 327 goto again; 328 case 0: 329 case UNVIS_NOCHAR: 330 break; 331 default: 332 return (-1); 333 } 334 } 335 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 336 dst++; 337 *dst = '\0'; 338 return (int)(dst - start); 339 } 340 341 int 342 strunvis(dst, src) 343 char *dst; 344 const char *src; 345 { 346 return strunvisx(dst, src, 0); 347 } 348 #endif 349
Indexes created Sun Sep 21 20:09:37 GMT 2025