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 #include <sys/types.h> 37 #include <errno.h> 38 #include <ctype.h> 39 #include <limits.h> 40 #include <string.h> 41 #include <stdlib.h> 42 43 #include "vis.h" 44 45 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 46 #define isvisible(c,flag) \ 47 (((c) == '\\' || (flag & VIS_ALL) == 0) && \ 48 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \ 49 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \ 50 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) || \ 51 ((flag & VIS_SP) == 0 && (c) == ' ') || \ 52 ((flag & VIS_TAB) == 0 && (c) == '\t') || \ 53 ((flag & VIS_NL) == 0 && (c) == '\n') || \ 54 ((flag & VIS_SAFE) && ((c) == '\b' || \ 55 (c) == '\007' || (c) == '\r' || \ 56 isgraph((u_char)(c)))))) 57 58 /* 59 * vis - visually encode characters 60 */ 61 char * 62 vis(char *dst, int c, int flag, int nextc) 63 { 64 if (isvisible(c, flag)) { 65 if ((c == '"' && (flag & VIS_DQ) != 0) || 66 (c == '\\' && (flag & VIS_NOSLASH) == 0)) 67 *dst++ = '\\'; 68 *dst++ = c; 69 *dst = '\0'; 70 return (dst); 71 } 72 73 if (flag & VIS_CSTYLE) { 74 switch(c) { 75 case '\n': 76 *dst++ = '\\'; 77 *dst++ = 'n'; 78 goto done; 79 case '\r': 80 *dst++ = '\\'; 81 *dst++ = 'r'; 82 goto done; 83 case '\b': 84 *dst++ = '\\'; 85 *dst++ = 'b'; 86 goto done; 87 case '\a': 88 *dst++ = '\\'; 89 *dst++ = 'a'; 90 goto done; 91 case '\v': 92 *dst++ = '\\'; 93 *dst++ = 'v'; 94 goto done; 95 case '\t': 96 *dst++ = '\\'; 97 *dst++ = 't'; 98 goto done; 99 case '\f': 100 *dst++ = '\\'; 101 *dst++ = 'f'; 102 goto done; 103 case ' ': 104 *dst++ = '\\'; 105 *dst++ = 's'; 106 goto done; 107 case '\0': 108 *dst++ = '\\'; 109 *dst++ = '0'; 110 if (isoctal(nextc)) { 111 *dst++ = '0'; 112 *dst++ = '0'; 113 } 114 goto done; 115 } 116 } 117 if (((c & 0177) == ' ') || (flag & VIS_OCTAL) || 118 ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) { 119 *dst++ = '\\'; 120 *dst++ = ((u_char)c >> 6 & 07) + '0'; 121 *dst++ = ((u_char)c >> 3 & 07) + '0'; 122 *dst++ = ((u_char)c & 07) + '0'; 123 goto done; 124 } 125 if ((flag & VIS_NOSLASH) == 0) 126 *dst++ = '\\'; 127 if (c & 0200) { 128 c &= 0177; 129 *dst++ = 'M'; 130 } 131 if (iscntrl((u_char)c)) { 132 *dst++ = '^'; 133 if (c == 0177) 134 *dst++ = '?'; 135 else 136 *dst++ = c + '@'; 137 } else { 138 *dst++ = '-'; 139 *dst++ = c; 140 } 141 done: 142 *dst = '\0'; 143 return (dst); 144 } 145 DEF_WEAK(vis); 146 147 /* 148 * strvis, strnvis, strvisx - visually encode characters from src into dst 149 * 150 * Dst must be 4 times the size of src to account for possible 151 * expansion. The length of dst, not including the trailing NULL, 152 * is returned. 153 * 154 * Strnvis will write no more than siz-1 bytes (and will NULL terminate). 155 * The number of bytes needed to fully encode the string is returned. 156 * 157 * Strvisx encodes exactly len bytes from src into dst. 158 * This is useful for encoding a block of data. 159 */ 160 int 161 strvis(char *dst, const char *src, int flag) 162 { 163 char c; 164 char *start; 165 166 for (start = dst; (c = *src);) 167 dst = vis(dst, c, flag, *++src); 168 *dst = '\0'; 169 return (dst - start); 170 } 171 DEF_WEAK(strvis); 172 173 int 174 strnvis(char *dst, const char *src, size_t siz, int flag) 175 { 176 char *start, *end; 177 char tbuf[5]; 178 int c, i; 179 180 i = 0; 181 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 182 if (isvisible(c, flag)) { 183 if ((c == '"' && (flag & VIS_DQ) != 0) || 184 (c == '\\' && (flag & VIS_NOSLASH) == 0)) { 185 /* need space for the extra '\\' */ 186 if (dst + 1 >= end) { 187 i = 2; 188 break; 189 } 190 *dst++ = '\\'; 191 } 192 i = 1; 193 *dst++ = c; 194 src++; 195 } else { 196 i = vis(tbuf, c, flag, *++src) - tbuf; 197 if (dst + i <= end) { 198 memcpy(dst, tbuf, i); 199 dst += i; 200 } else { 201 src--; 202 break; 203 } 204 } 205 } 206 if (siz > 0) 207 *dst = '\0'; 208 if (dst + i > end) { 209 /* adjust return value for truncation */ 210 while ((c = *src)) 211 dst += vis(tbuf, c, flag, *++src) - tbuf; 212 } 213 return (dst - start); 214 } 215 216 int 217 stravis(char **outp, const char *src, int flag) 218 { 219 char *buf; 220 int len, serrno; 221 222 buf = reallocarray(NULL, 4, strlen(src) + 1); 223 if (buf == NULL) 224 return -1; 225 len = strvis(buf, src, flag); 226 serrno = errno; 227 *outp = realloc(buf, len + 1); 228 if (*outp == NULL) { 229 *outp = buf; 230 errno = serrno; 231 } 232 return (len); 233 } 234 235 int 236 strvisx(char *dst, const char *src, size_t len, int flag) 237 { 238 char c; 239 char *start; 240 241 for (start = dst; len > 1; len--) { 242 c = *src; 243 dst = vis(dst, c, flag, *++src); 244 } 245 if (len) 246 dst = vis(dst, *src, flag, '\0'); 247 *dst = '\0'; 248 return (dst - start); 249 } 250 251 #endif 252