1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $FreeBSD: src/lib/libc/gen/unvis.c,v 1.4.8.1 2000/08/17 08:25:54 jhb Exp $ 34 * $DragonFly: src/lib/libc/gen/unvis.c,v 1.4 2005/11/13 00:07:42 swildner Exp $ 35 * 36 * @(#)unvis.c 8.1 (Berkeley) 6/4/93 37 */ 38 39 #include <sys/types.h> 40 #include <vis.h> 41 42 /* 43 * decode driven by state machine 44 */ 45 #define S_GROUND 0 /* haven't seen escape char */ 46 #define S_START 1 /* start decoding special sequence */ 47 #define S_META 2 /* metachar started (M) */ 48 #define S_META1 3 /* metachar more, regular char (-) */ 49 #define S_CTRL 4 /* control char started (^) */ 50 #define S_OCTAL2 5 /* octal digit 2 */ 51 #define S_OCTAL3 6 /* octal digit 3 */ 52 #define S_HEX2 7 /* hex digit 2 */ 53 54 #define S_HTTP 0x080 /* %HEXHEX escape */ 55 56 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 57 #define ishex(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '9' || ((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f') 58 59 /* 60 * unvis - decode characters previously encoded by vis 61 */ 62 int 63 unvis(char *cp, int c, int *astate, int flag) 64 { 65 66 if (flag & UNVIS_END) { 67 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 68 *astate = S_GROUND; 69 return (UNVIS_VALID); 70 } 71 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 72 } 73 74 switch (*astate & ~S_HTTP) { 75 76 case S_GROUND: 77 *cp = 0; 78 if (c == '\\') { 79 *astate = S_START; 80 return (0); 81 } 82 if (flag & VIS_HTTPSTYLE && c == '%') { 83 *astate = S_START | S_HTTP; 84 return (0); 85 } 86 *cp = c; 87 return (UNVIS_VALID); 88 89 case S_START: 90 if (*astate & S_HTTP) { 91 if (ishex(tolower(c))) { 92 *cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a'); 93 *astate = S_HEX2; 94 return (0); 95 } 96 } 97 switch(c) { 98 case '\\': 99 *cp = c; 100 *astate = S_GROUND; 101 return (UNVIS_VALID); 102 case '0': case '1': case '2': case '3': 103 case '4': case '5': case '6': case '7': 104 *cp = (c - '0'); 105 *astate = S_OCTAL2; 106 return (0); 107 case 'M': 108 *cp = 0200; 109 *astate = S_META; 110 return (0); 111 case '^': 112 *astate = S_CTRL; 113 return (0); 114 case 'n': 115 *cp = '\n'; 116 *astate = S_GROUND; 117 return (UNVIS_VALID); 118 case 'r': 119 *cp = '\r'; 120 *astate = S_GROUND; 121 return (UNVIS_VALID); 122 case 'b': 123 *cp = '\b'; 124 *astate = S_GROUND; 125 return (UNVIS_VALID); 126 case 'a': 127 *cp = '\007'; 128 *astate = S_GROUND; 129 return (UNVIS_VALID); 130 case 'v': 131 *cp = '\v'; 132 *astate = S_GROUND; 133 return (UNVIS_VALID); 134 case 't': 135 *cp = '\t'; 136 *astate = S_GROUND; 137 return (UNVIS_VALID); 138 case 'f': 139 *cp = '\f'; 140 *astate = S_GROUND; 141 return (UNVIS_VALID); 142 case 's': 143 *cp = ' '; 144 *astate = S_GROUND; 145 return (UNVIS_VALID); 146 case 'E': 147 *cp = '\033'; 148 *astate = S_GROUND; 149 return (UNVIS_VALID); 150 case '\n': 151 /* 152 * hidden newline 153 */ 154 *astate = S_GROUND; 155 return (UNVIS_NOCHAR); 156 case '$': 157 /* 158 * hidden marker 159 */ 160 *astate = S_GROUND; 161 return (UNVIS_NOCHAR); 162 } 163 *astate = S_GROUND; 164 return (UNVIS_SYNBAD); 165 166 case S_META: 167 if (c == '-') 168 *astate = S_META1; 169 else if (c == '^') 170 *astate = S_CTRL; 171 else { 172 *astate = S_GROUND; 173 return (UNVIS_SYNBAD); 174 } 175 return (0); 176 177 case S_META1: 178 *astate = S_GROUND; 179 *cp |= c; 180 return (UNVIS_VALID); 181 182 case S_CTRL: 183 if (c == '?') 184 *cp |= 0177; 185 else 186 *cp |= c & 037; 187 *astate = S_GROUND; 188 return (UNVIS_VALID); 189 190 case S_OCTAL2: /* second possible octal digit */ 191 if (isoctal(c)) { 192 /* 193 * yes - and maybe a third 194 */ 195 *cp = (*cp << 3) + (c - '0'); 196 *astate = S_OCTAL3; 197 return (0); 198 } 199 /* 200 * no - done with current sequence, push back passed char 201 */ 202 *astate = S_GROUND; 203 return (UNVIS_VALIDPUSH); 204 205 case S_OCTAL3: /* third possible octal digit */ 206 *astate = S_GROUND; 207 if (isoctal(c)) { 208 *cp = (*cp << 3) + (c - '0'); 209 return (UNVIS_VALID); 210 } 211 /* 212 * we were done, push back passed char 213 */ 214 return (UNVIS_VALIDPUSH); 215 216 case S_HEX2: /* second mandatory hex digit */ 217 if (ishex(tolower(c))) { 218 *cp = (isdigit(c) ? (*cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10)); 219 } 220 *astate = S_GROUND; 221 return (UNVIS_VALID); 222 223 default: 224 /* 225 * decoder in unknown state - (probably uninitialized) 226 */ 227 *astate = S_GROUND; 228 return (UNVIS_SYNBAD); 229 } 230 } 231 232 /* 233 * strunvis - decode src into dst 234 * 235 * Number of chars decoded into dst is returned, -1 on error. 236 * Dst is null terminated. 237 */ 238 239 int 240 strunvis(char *dst, const char *src) 241 { 242 char c; 243 char *start = dst; 244 int state = 0; 245 246 while ( (c = *src++) ) { 247 again: 248 switch (unvis(dst, c, &state, 0)) { 249 case UNVIS_VALID: 250 dst++; 251 break; 252 case UNVIS_VALIDPUSH: 253 dst++; 254 goto again; 255 case 0: 256 case UNVIS_NOCHAR: 257 break; 258 default: 259 return (-1); 260 } 261 } 262 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 263 dst++; 264 *dst = '\0'; 265 return (dst - start); 266 } 267 268 int 269 strunvisx(char *dst, const char *src, int flag) 270 { 271 char c; 272 char *start = dst; 273 int state = 0; 274 275 while ( (c = *src++) ) { 276 again: 277 switch (unvis(dst, c, &state, flag)) { 278 case UNVIS_VALID: 279 dst++; 280 break; 281 case UNVIS_VALIDPUSH: 282 dst++; 283 goto again; 284 case 0: 285 case UNVIS_NOCHAR: 286 break; 287 default: 288 return (-1); 289 } 290 } 291 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 292 dst++; 293 *dst = '\0'; 294 return (dst - start); 295 } 296