1 /* $NetBSD: vis.c,v 1.38 2008/09/04 09:41:44 lukem 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 <sys/cdefs.h> 59 #if defined(LIBC_SCCS) && !defined(lint) 60 __RCSID("$NetBSD: vis.c,v 1.38 2008/09/04 09:41:44 lukem Exp $"); 61 #endif /* LIBC_SCCS and not lint */ 62 63 #include "namespace.h" 64 #include <sys/types.h> 65 66 #include <assert.h> 67 #include <vis.h> 68 #include <stdlib.h> 69 70 #ifdef __weak_alias 71 __weak_alias(strsvis,_strsvis) 72 __weak_alias(strsvisx,_strsvisx) 73 __weak_alias(strvis,_strvis) 74 __weak_alias(strvisx,_strvisx) 75 __weak_alias(svis,_svis) 76 __weak_alias(vis,_vis) 77 #endif 78 79 #if !HAVE_VIS || !HAVE_SVIS 80 #include <ctype.h> 81 #include <limits.h> 82 #include <stdio.h> 83 #include <string.h> 84 85 static char *do_svis(char *, int, int, int, const char *); 86 87 #undef BELL 88 #define BELL '\a' 89 90 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 91 #define iswhite(c) (c == ' ' || c == '\t' || c == '\n') 92 #define issafe(c) (c == '\b' || c == BELL || c == '\r') 93 #define xtoa(c) "0123456789abcdef"[c] 94 95 #define MAXEXTRAS 5 96 97 #define MAKEEXTRALIST(flag, extra, orig_str) \ 98 do { \ 99 const char *orig = orig_str; \ 100 const char *o = orig; \ 101 char *e; \ 102 while (*o++) \ 103 continue; \ 104 extra = malloc((size_t)((o - orig) + MAXEXTRAS)); \ 105 if (!extra) break; \ 106 for (o = orig, e = extra; (*e++ = *o++) != '\0';) \ 107 continue; \ 108 e--; \ 109 if (flag & VIS_SP) *e++ = ' '; \ 110 if (flag & VIS_TAB) *e++ = '\t'; \ 111 if (flag & VIS_NL) *e++ = '\n'; \ 112 if ((flag & VIS_NOSLASH) == 0) *e++ = '\\'; \ 113 *e = '\0'; \ 114 } while (/*CONSTCOND*/0) 115 116 /* 117 * This is do_hvis, for HTTP style (RFC 1808) 118 */ 119 static char * 120 do_hvis(char *dst, int c, int flag, int nextc, const char *extra) 121 { 122 if (!isascii(c) || !isalnum(c) || strchr("$-_.+!*'(),", c) != NULL) { 123 *dst++ = '%'; 124 *dst++ = xtoa(((unsigned int)c >> 4) & 0xf); 125 *dst++ = xtoa((unsigned int)c & 0xf); 126 } else { 127 dst = do_svis(dst, c, flag, nextc, extra); 128 } 129 return dst; 130 } 131 132 /* 133 * This is do_vis, the central code of vis. 134 * dst: Pointer to the destination buffer 135 * c: Character to encode 136 * flag: Flag word 137 * nextc: The character following 'c' 138 * extra: Pointer to the list of extra characters to be 139 * backslash-protected. 140 */ 141 static char * 142 do_svis(char *dst, int c, int flag, int nextc, const char *extra) 143 { 144 int isextra; 145 isextra = strchr(extra, c) != NULL; 146 if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) || 147 ((flag & VIS_SAFE) && issafe(c)))) { 148 *dst++ = c; 149 return dst; 150 } 151 if (flag & VIS_CSTYLE) { 152 switch (c) { 153 case '\n': 154 *dst++ = '\\'; *dst++ = 'n'; 155 return dst; 156 case '\r': 157 *dst++ = '\\'; *dst++ = 'r'; 158 return dst; 159 case '\b': 160 *dst++ = '\\'; *dst++ = 'b'; 161 return dst; 162 case BELL: 163 *dst++ = '\\'; *dst++ = 'a'; 164 return dst; 165 case '\v': 166 *dst++ = '\\'; *dst++ = 'v'; 167 return dst; 168 case '\t': 169 *dst++ = '\\'; *dst++ = 't'; 170 return dst; 171 case '\f': 172 *dst++ = '\\'; *dst++ = 'f'; 173 return dst; 174 case ' ': 175 *dst++ = '\\'; *dst++ = 's'; 176 return dst; 177 case '\0': 178 *dst++ = '\\'; *dst++ = '0'; 179 if (isoctal(nextc)) { 180 *dst++ = '0'; 181 *dst++ = '0'; 182 } 183 return dst; 184 default: 185 if (isgraph(c)) { 186 *dst++ = '\\'; *dst++ = c; 187 return dst; 188 } 189 } 190 } 191 if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) { 192 *dst++ = '\\'; 193 *dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0'; 194 *dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0'; 195 *dst++ = (c & 07) + '0'; 196 } else { 197 if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\'; 198 if (c & 0200) { 199 c &= 0177; *dst++ = 'M'; 200 } 201 if (iscntrl(c)) { 202 *dst++ = '^'; 203 if (c == 0177) 204 *dst++ = '?'; 205 else 206 *dst++ = c + '@'; 207 } else { 208 *dst++ = '-'; *dst++ = c; 209 } 210 } 211 return dst; 212 } 213 214 215 /* 216 * svis - visually encode characters, also encoding the characters 217 * pointed to by `extra' 218 */ 219 char * 220 svis(char *dst, int c, int flag, int nextc, const char *extra) 221 { 222 char *nextra = NULL; 223 224 _DIAGASSERT(dst != NULL); 225 _DIAGASSERT(extra != NULL); 226 MAKEEXTRALIST(flag, nextra, extra); 227 if (!nextra) { 228 *dst = '\0'; /* can't create nextra, return "" */ 229 return dst; 230 } 231 if (flag & VIS_HTTPSTYLE) 232 dst = do_hvis(dst, c, flag, nextc, nextra); 233 else 234 dst = do_svis(dst, c, flag, nextc, nextra); 235 free(nextra); 236 *dst = '\0'; 237 return dst; 238 } 239 240 241 /* 242 * strsvis, strsvisx - visually encode characters from src into dst 243 * 244 * Extra is a pointer to a \0-terminated list of characters to 245 * be encoded, too. These functions are useful e. g. to 246 * encode strings in such a way so that they are not interpreted 247 * by a shell. 248 * 249 * Dst must be 4 times the size of src to account for possible 250 * expansion. The length of dst, not including the trailing NULL, 251 * is returned. 252 * 253 * Strsvisx encodes exactly len bytes from src into dst. 254 * This is useful for encoding a block of data. 255 */ 256 int 257 strsvis(char *dst, const char *csrc, int flag, const char *extra) 258 { 259 int c; 260 char *start; 261 char *nextra = NULL; 262 const unsigned char *src = (const unsigned char *)csrc; 263 264 _DIAGASSERT(dst != NULL); 265 _DIAGASSERT(src != NULL); 266 _DIAGASSERT(extra != NULL); 267 MAKEEXTRALIST(flag, nextra, extra); 268 if (!nextra) { 269 *dst = '\0'; /* can't create nextra, return "" */ 270 return 0; 271 } 272 if (flag & VIS_HTTPSTYLE) { 273 for (start = dst; (c = *src++) != '\0'; /* empty */) 274 dst = do_hvis(dst, c, flag, *src, nextra); 275 } else { 276 for (start = dst; (c = *src++) != '\0'; /* empty */) 277 dst = do_svis(dst, c, flag, *src, nextra); 278 } 279 free(nextra); 280 *dst = '\0'; 281 return (dst - start); 282 } 283 284 285 int 286 strsvisx(char *dst, const char *csrc, size_t len, int flag, const char *extra) 287 { 288 unsigned char c; 289 char *start; 290 char *nextra = NULL; 291 const unsigned char *src = (const unsigned char *)csrc; 292 293 _DIAGASSERT(dst != NULL); 294 _DIAGASSERT(src != NULL); 295 _DIAGASSERT(extra != NULL); 296 MAKEEXTRALIST(flag, nextra, extra); 297 if (! nextra) { 298 *dst = '\0'; /* can't create nextra, return "" */ 299 return 0; 300 } 301 302 if (flag & VIS_HTTPSTYLE) { 303 for (start = dst; len > 0; len--) { 304 c = *src++; 305 dst = do_hvis(dst, c, flag, 306 len > 1 ? *src : '\0', nextra); 307 } 308 } else { 309 for (start = dst; len > 0; len--) { 310 c = *src++; 311 dst = do_svis(dst, c, flag, 312 len > 1 ? *src : '\0', nextra); 313 } 314 } 315 free(nextra); 316 *dst = '\0'; 317 return (dst - start); 318 } 319 #endif 320 321 #if !HAVE_VIS 322 /* 323 * vis - visually encode characters 324 */ 325 char * 326 vis(char *dst, int c, int flag, int nextc) 327 { 328 char *extra = NULL; 329 unsigned char uc = (unsigned char)c; 330 331 _DIAGASSERT(dst != NULL); 332 333 MAKEEXTRALIST(flag, extra, ""); 334 if (! extra) { 335 *dst = '\0'; /* can't create extra, return "" */ 336 return dst; 337 } 338 if (flag & VIS_HTTPSTYLE) 339 dst = do_hvis(dst, uc, flag, nextc, extra); 340 else 341 dst = do_svis(dst, uc, flag, nextc, extra); 342 free(extra); 343 *dst = '\0'; 344 return dst; 345 } 346 347 348 /* 349 * strvis, strvisx - visually encode characters from src into dst 350 * 351 * Dst must be 4 times the size of src to account for possible 352 * expansion. The length of dst, not including the trailing NULL, 353 * is returned. 354 * 355 * Strvisx encodes exactly len bytes from src into dst. 356 * This is useful for encoding a block of data. 357 */ 358 int 359 strvis(char *dst, const char *src, int flag) 360 { 361 char *extra = NULL; 362 int rv; 363 364 MAKEEXTRALIST(flag, extra, ""); 365 if (!extra) { 366 *dst = '\0'; /* can't create extra, return "" */ 367 return 0; 368 } 369 rv = strsvis(dst, src, flag, extra); 370 free(extra); 371 return rv; 372 } 373 374 375 int 376 strvisx(char *dst, const char *src, size_t len, int flag) 377 { 378 char *extra = NULL; 379 int rv; 380 381 MAKEEXTRALIST(flag, extra, ""); 382 if (!extra) { 383 *dst = '\0'; /* can't create extra, return "" */ 384 return 0; 385 } 386 rv = strsvisx(dst, src, len, flag, extra); 387 free(extra); 388 return rv; 389 } 390 #endif 391