vis.c
1 /* $NetBSD: vis.c,v 1.41 2009/11/23 10:08:47 plunky 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 /*- 33 * Copyright (c) 1999, 2005 The NetBSD Foundation, Inc. 34 * All rights reserved. 35 * 36 * Redistribution and use in source and binary forms, with or without 37 * modification, are permitted provided that the following conditions 38 * are met: 39 * 1. Redistributions of source code must retain the above copyright 40 * notice, this list of conditions and the following disclaimer. 41 * 2. Redistributions in binary form must reproduce the above copyright 42 * notice, this list of conditions and the following disclaimer in the 43 * documentation and/or other materials provided with the distribution. 44 * 45 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 46 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 47 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 48 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 49 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 50 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 51 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 52 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 53 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 54 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 55 * POSSIBILITY OF SUCH DAMAGE. 56 */ 57 58 #include "config.h" 59 60 #if defined(LIBC_SCCS) && !defined(lint) 61 __RCSID("$NetBSD: vis.c,v 1.41 2009/11/23 10:08:47 plunky Exp $"); 62 #endif /* LIBC_SCCS and not lint */ 63 64 #include <sys/types.h> 65 66 #include <assert.h> 67 #include <vis.h> 68 #include <stdlib.h> 69 70 #ifdef __weak_alias 71 __weak_alias(strsvis,_strsvis) 72 __weak_alias(strsvisx,_strsvisx) 73 __weak_alias(strvis,_strvis) 74 __weak_alias(strvisx,_strvisx) 75 __weak_alias(svis,_svis) 76 __weak_alias(vis,_vis) 77 #endif 78 79 #if !HAVE_VIS || !HAVE_SVIS 80 #include <ctype.h> 81 #include <limits.h> 82 #include <stdio.h> 83 #include <string.h> 84 85 static char *do_svis(char *, int, int, int, const char *); 86 87 #undef BELL 88 #define BELL '\a' 89 90 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 91 #define iswhite(c) (c == ' ' || c == '\t' || c == '\n') 92 #define issafe(c) (c == '\b' || c == BELL || c == '\r') 93 #define xtoa(c) "0123456789abcdef"[c] 94 #define XTOA(c) "0123456789ABCDEF"[c] 95 96 #define MAXEXTRAS 5 97 98 #define MAKEEXTRALIST(flag, extra, orig_str) \ 99 do { \ 100 const char *orig = orig_str; \ 101 const char *o = orig; \ 102 char *e; \ 103 while (*o++) \ 104 continue; \ 105 extra = malloc((size_t)((o - orig) + MAXEXTRAS)); \ 106 if (!extra) break; \ 107 for (o = orig, e = extra; (*e++ = *o++) != '\0';) \ 108 continue; \ 109 e--; \ 110 if (flag & VIS_SP) *e++ = ' '; \ 111 if (flag & VIS_TAB) *e++ = '\t'; \ 112 if (flag & VIS_NL) *e++ = '\n'; \ 113 if ((flag & VIS_NOSLASH) == 0) *e++ = '\\'; \ 114 *e = '\0'; \ 115 } while (/*CONSTCOND*/0) 116 117 /* 118 * This is do_hvis, for HTTP style (RFC 1808) 119 */ 120 static char * 121 do_hvis(char *dst, int c, int flag, int nextc, const char *extra) 122 { 123 124 if ((isascii(c) && isalnum(c)) 125 /* safe */ 126 || c == '$' || c == '-' || c == '_' || c == '.' || c == '+' 127 /* extra */ 128 || c == '!' || c == '*' || c == '\'' || c == '(' || c == ')' 129 || c == ',') { 130 dst = do_svis(dst, c, flag, nextc, extra); 131 } else { 132 *dst++ = '%'; 133 *dst++ = xtoa(((unsigned int)c >> 4) & 0xf); 134 *dst++ = xtoa((unsigned int)c & 0xf); 135 } 136 137 return dst; 138 } 139 140 /* 141 * This is do_mvis, for Quoted-Printable MIME (RFC 2045) 142 * NB: No handling of long lines or CRLF. 143 */ 144 static char * 145 do_mvis(char *dst, int c, int flag, int nextc, const char *extra) 146 { 147 if ((c != '\n') && 148 /* Space at the end of the line */ 149 ((isspace(c) && (nextc == '\r' || nextc == '\n')) || 150 /* Out of range */ 151 (!isspace(c) && (c < 33 || (c > 60 && c < 62) || c > 126)) || 152 /* Specific char to be escaped */ 153 strchr("#$@[\\]^`{|}~", c) != NULL)) { 154 *dst++ = '='; 155 *dst++ = XTOA(((unsigned int)c >> 4) & 0xf); 156 *dst++ = XTOA((unsigned int)c & 0xf); 157 } else { 158 dst = do_svis(dst, c, flag, nextc, extra); 159 } 160 return dst; 161 } 162 163 /* 164 * This is do_vis, the central code of vis. 165 * dst: Pointer to the destination buffer 166 * c: Character to encode 167 * flag: Flag word 168 * nextc: The character following 'c' 169 * extra: Pointer to the list of extra characters to be 170 * backslash-protected. 171 */ 172 static char * 173 do_svis(char *dst, int c, int flag, int nextc, const char *extra) 174 { 175 int isextra; 176 isextra = strchr(extra, c) != NULL; 177 if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) || 178 ((flag & VIS_SAFE) && issafe(c)))) { 179 *dst++ = c; 180 return dst; 181 } 182 if (flag & VIS_CSTYLE) { 183 switch (c) { 184 case '\n': 185 *dst++ = '\\'; *dst++ = 'n'; 186 return dst; 187 case '\r': 188 *dst++ = '\\'; *dst++ = 'r'; 189 return dst; 190 case '\b': 191 *dst++ = '\\'; *dst++ = 'b'; 192 return dst; 193 case BELL: 194 *dst++ = '\\'; *dst++ = 'a'; 195 return dst; 196 case '\v': 197 *dst++ = '\\'; *dst++ = 'v'; 198 return dst; 199 case '\t': 200 *dst++ = '\\'; *dst++ = 't'; 201 return dst; 202 case '\f': 203 *dst++ = '\\'; *dst++ = 'f'; 204 return dst; 205 case ' ': 206 *dst++ = '\\'; *dst++ = 's'; 207 return dst; 208 case '\0': 209 *dst++ = '\\'; *dst++ = '0'; 210 if (isoctal(nextc)) { 211 *dst++ = '0'; 212 *dst++ = '0'; 213 } 214 return dst; 215 default: 216 if (isgraph(c)) { 217 *dst++ = '\\'; *dst++ = c; 218 return dst; 219 } 220 } 221 } 222 if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) { 223 *dst++ = '\\'; 224 *dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0'; 225 *dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0'; 226 *dst++ = (c & 07) + '0'; 227 } else { 228 if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\'; 229 if (c & 0200) { 230 c &= 0177; *dst++ = 'M'; 231 } 232 if (iscntrl(c)) { 233 *dst++ = '^'; 234 if (c == 0177) 235 *dst++ = '?'; 236 else 237 *dst++ = c + '@'; 238 } else { 239 *dst++ = '-'; *dst++ = c; 240 } 241 } 242 return dst; 243 } 244 245 typedef char *(*visfun_t)(char *, int, int, int, const char *); 246 247 /* 248 * Return the appropriate encoding function depending on the flags given. 249 */ 250 static visfun_t 251 getvisfun(int flag) 252 { 253 if (flag & VIS_HTTPSTYLE) 254 return do_hvis; 255 if (flag & VIS_MIMESTYLE) 256 return do_mvis; 257 return do_svis; 258 } 259 260 /* 261 * svis - visually encode characters, also encoding the characters 262 * pointed to by `extra' 263 */ 264 char * 265 svis(char *dst, int c, int flag, int nextc, const char *extra) 266 { 267 char *nextra = NULL; 268 visfun_t f; 269 270 _DIAGASSERT(dst != NULL); 271 _DIAGASSERT(extra != NULL); 272 MAKEEXTRALIST(flag, nextra, extra); 273 if (!nextra) { 274 *dst = '\0'; /* can't create nextra, return "" */ 275 return dst; 276 } 277 f = getvisfun(flag); 278 dst = (*f)(dst, c, flag, nextc, nextra); 279 free(nextra); 280 *dst = '\0'; 281 return dst; 282 } 283 284 285 /* 286 * strsvis, strsvisx - visually encode characters from src into dst 287 * 288 * Extra is a pointer to a \0-terminated list of characters to 289 * be encoded, too. These functions are useful e. g. to 290 * encode strings in such a way so that they are not interpreted 291 * by a shell. 292 * 293 * Dst must be 4 times the size of src to account for possible 294 * expansion. The length of dst, not including the trailing NULL, 295 * is returned. 296 * 297 * Strsvisx encodes exactly len bytes from src into dst. 298 * This is useful for encoding a block of data. 299 */ 300 int 301 strsvis(char *dst, const char *csrc, int flag, const char *extra) 302 { 303 int c; 304 char *start; 305 char *nextra = NULL; 306 const unsigned char *src = (const unsigned char *)csrc; 307 visfun_t f; 308 309 _DIAGASSERT(dst != NULL); 310 _DIAGASSERT(src != NULL); 311 _DIAGASSERT(extra != NULL); 312 MAKEEXTRALIST(flag, nextra, extra); 313 if (!nextra) { 314 *dst = '\0'; /* can't create nextra, return "" */ 315 return 0; 316 } 317 f = getvisfun(flag); 318 for (start = dst; (c = *src++) != '\0'; /* empty */) 319 dst = (*f)(dst, c, flag, *src, nextra); 320 free(nextra); 321 *dst = '\0'; 322 return (int)(dst - start); 323 } 324 325 326 int 327 strsvisx(char *dst, const char *csrc, size_t len, int flag, const char *extra) 328 { 329 unsigned char c; 330 char *start; 331 char *nextra = NULL; 332 const unsigned char *src = (const unsigned char *)csrc; 333 visfun_t f; 334 335 _DIAGASSERT(dst != NULL); 336 _DIAGASSERT(src != NULL); 337 _DIAGASSERT(extra != NULL); 338 MAKEEXTRALIST(flag, nextra, extra); 339 if (! nextra) { 340 *dst = '\0'; /* can't create nextra, return "" */ 341 return 0; 342 } 343 344 f = getvisfun(flag); 345 for (start = dst; len > 0; len--) { 346 c = *src++; 347 dst = (*f)(dst, c, flag, len > 1 ? *src : '\0', nextra); 348 } 349 free(nextra); 350 *dst = '\0'; 351 return (int)(dst - start); 352 } 353 #endif 354 355 #if !HAVE_VIS 356 /* 357 * vis - visually encode characters 358 */ 359 char * 360 vis(char *dst, int c, int flag, int nextc) 361 { 362 char *extra = NULL; 363 unsigned char uc = (unsigned char)c; 364 visfun_t f; 365 366 _DIAGASSERT(dst != NULL); 367 368 MAKEEXTRALIST(flag, extra, ""); 369 if (! extra) { 370 *dst = '\0'; /* can't create extra, return "" */ 371 return dst; 372 } 373 f = getvisfun(flag); 374 dst = (*f)(dst, uc, flag, nextc, extra); 375 free(extra); 376 *dst = '\0'; 377 return dst; 378 } 379 380 381 /* 382 * strvis, strvisx - visually encode characters from src into dst 383 * 384 * Dst must be 4 times the size of src to account for possible 385 * expansion. The length of dst, not including the trailing NULL, 386 * is returned. 387 * 388 * Strvisx encodes exactly len bytes from src into dst. 389 * This is useful for encoding a block of data. 390 */ 391 int 392 strvis(char *dst, const char *src, int flag) 393 { 394 char *extra = NULL; 395 int rv; 396 397 MAKEEXTRALIST(flag, extra, ""); 398 if (!extra) { 399 *dst = '\0'; /* can't create extra, return "" */ 400 return 0; 401 } 402 rv = strsvis(dst, src, flag, extra); 403 free(extra); 404 return rv; 405 } 406 407 408 int 409 strvisx(char *dst, const char *src, size_t len, int flag) 410 { 411 char *extra = NULL; 412 int rv; 413 414 MAKEEXTRALIST(flag, extra, ""); 415 if (!extra) { 416 *dst = '\0'; /* can't create extra, return "" */ 417 return 0; 418 } 419 rv = strsvisx(dst, src, len, flag, extra); 420 free(extra); 421 return rv; 422 } 423 #endif