1 /* $OpenBSD: vis.c,v 1.25 2015/09/13 11:32:51 guenther Exp $ */ 2 /*- 3 * Copyright (c) 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 /* OPENBSD ORIGINAL: lib/libc/gen/vis.c */ 32 33 #include "includes.h" 34 #if !defined(HAVE_STRNVIS) || defined(BROKEN_STRNVIS) 35 36 /* 37 * We want these to override in the BROKEN_STRNVIS case. TO avoid future sync 38 * problems no-op out the weak symbol definition rather than remove it. 39 */ 40 #define DEF_WEAK(x) 41 42 #include <sys/types.h> 43 #include <errno.h> 44 #include <ctype.h> 45 #include <limits.h> 46 #include <string.h> 47 #include <stdlib.h> 48 49 #include "vis.h" 50 51 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 52 #define isvisible(c,flag) \ 53 (((c) == '\\' || (flag & VIS_ALL) == 0) && \ 54 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \ 55 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \ 56 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) || \ 57 ((flag & VIS_SP) == 0 && (c) == ' ') || \ 58 ((flag & VIS_TAB) == 0 && (c) == '\t') || \ 59 ((flag & VIS_NL) == 0 && (c) == '\n') || \ 60 ((flag & VIS_SAFE) && ((c) == '\b' || \ 61 (c) == '\007' || (c) == '\r' || \ 62 isgraph((u_char)(c)))))) 63 64 /* 65 * vis - visually encode characters 66 */ 67 char * 68 vis(char *dst, int c, int flag, int nextc) 69 { 70 if (isvisible(c, flag)) { 71 if ((c == '"' && (flag & VIS_DQ) != 0) || 72 (c == '\\' && (flag & VIS_NOSLASH) == 0)) 73 *dst++ = '\\'; 74 *dst++ = c; 75 *dst = '\0'; 76 return (dst); 77 } 78 79 if (flag & VIS_CSTYLE) { 80 switch(c) { 81 case '\n': 82 *dst++ = '\\'; 83 *dst++ = 'n'; 84 goto done; 85 case '\r': 86 *dst++ = '\\'; 87 *dst++ = 'r'; 88 goto done; 89 case '\b': 90 *dst++ = '\\'; 91 *dst++ = 'b'; 92 goto done; 93 case '\a': 94 *dst++ = '\\'; 95 *dst++ = 'a'; 96 goto done; 97 case '\v': 98 *dst++ = '\\'; 99 *dst++ = 'v'; 100 goto done; 101 case '\t': 102 *dst++ = '\\'; 103 *dst++ = 't'; 104 goto done; 105 case '\f': 106 *dst++ = '\\'; 107 *dst++ = 'f'; 108 goto done; 109 case ' ': 110 *dst++ = '\\'; 111 *dst++ = 's'; 112 goto done; 113 case '\0': 114 *dst++ = '\\'; 115 *dst++ = '0'; 116 if (isoctal(nextc)) { 117 *dst++ = '0'; 118 *dst++ = '0'; 119 } 120 goto done; 121 } 122 } 123 if (((c & 0177) == ' ') || (flag & VIS_OCTAL) || 124 ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) { 125 *dst++ = '\\'; 126 *dst++ = ((u_char)c >> 6 & 07) + '0'; 127 *dst++ = ((u_char)c >> 3 & 07) + '0'; 128 *dst++ = ((u_char)c & 07) + '0'; 129 goto done; 130 } 131 if ((flag & VIS_NOSLASH) == 0) 132 *dst++ = '\\'; 133 if (c & 0200) { 134 c &= 0177; 135 *dst++ = 'M'; 136 } 137 if (iscntrl((u_char)c)) { 138 *dst++ = '^'; 139 if (c == 0177) 140 *dst++ = '?'; 141 else 142 *dst++ = c + '@'; 143 } else { 144 *dst++ = '-'; 145 *dst++ = c; 146 } 147 done: 148 *dst = '\0'; 149 return (dst); 150 } 151 DEF_WEAK(vis); 152 153 /* 154 * strvis, strnvis, strvisx - visually encode characters from src into dst 155 * 156 * Dst must be 4 times the size of src to account for possible 157 * expansion. The length of dst, not including the trailing NULL, 158 * is returned. 159 * 160 * Strnvis will write no more than siz-1 bytes (and will NULL terminate). 161 * The number of bytes needed to fully encode the string is returned. 162 * 163 * Strvisx encodes exactly len bytes from src into dst. 164 * This is useful for encoding a block of data. 165 */ 166 int 167 strvis(char *dst, const char *src, int flag) 168 { 169 char c; 170 char *start; 171 172 for (start = dst; (c = *src);) 173 dst = vis(dst, c, flag, *++src); 174 *dst = '\0'; 175 return (dst - start); 176 } 177 DEF_WEAK(strvis); 178 179 int 180 strnvis(char *dst, const char *src, size_t siz, int flag) 181 { 182 char *start, *end; 183 char tbuf[5]; 184 int c, i; 185 186 i = 0; 187 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 188 if (isvisible(c, flag)) { 189 if ((c == '"' && (flag & VIS_DQ) != 0) || 190 (c == '\\' && (flag & VIS_NOSLASH) == 0)) { 191 /* need space for the extra '\\' */ 192 if (dst + 1 >= end) { 193 i = 2; 194 break; 195 } 196 *dst++ = '\\'; 197 } 198 i = 1; 199 *dst++ = c; 200 src++; 201 } else { 202 i = vis(tbuf, c, flag, *++src) - tbuf; 203 if (dst + i <= end) { 204 memcpy(dst, tbuf, i); 205 dst += i; 206 } else { 207 src--; 208 break; 209 } 210 } 211 } 212 if (siz > 0) 213 *dst = '\0'; 214 if (dst + i > end) { 215 /* adjust return value for truncation */ 216 while ((c = *src)) 217 dst += vis(tbuf, c, flag, *++src) - tbuf; 218 } 219 return (dst - start); 220 } 221 222 int 223 stravis(char **outp, const char *src, int flag) 224 { 225 char *buf; 226 int len, serrno; 227 228 buf = reallocarray(NULL, 4, strlen(src) + 1); 229 if (buf == NULL) 230 return -1; 231 len = strvis(buf, src, flag); 232 serrno = errno; 233 *outp = realloc(buf, len + 1); 234 if (*outp == NULL) { 235 *outp = buf; 236 errno = serrno; 237 } 238 return (len); 239 } 240 241 int 242 strvisx(char *dst, const char *src, size_t len, int flag) 243 { 244 char c; 245 char *start; 246 247 for (start = dst; len > 1; len--) { 248 c = *src; 249 dst = vis(dst, c, flag, *++src); 250 } 251 if (len) 252 dst = vis(dst, *src, flag, '\0'); 253 *dst = '\0'; 254 return (dst - start); 255 } 256 257 #endif 258