crypto/openssh-4/openbsd-compat/vis.c

   1 /* OPENBSD ORIGINAL: lib/libc/gen/vis.c */
   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 #include "includes.h"
  32 #if !defined(HAVE_STRNVIS)
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char rcsid[] = "$OpenBSD: vis.c,v 1.12 2003/06/02 20:18:35 millert Exp $";
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #include <ctype.h>
  39 #include <string.h>
  40
  41 #include "vis.h"
  42
  43 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  44 #define isvisible(c)    (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \
  45                                 isgraph((u_char)(c))) ||                     \
  46                                 ((flag & VIS_SP) == 0 && (c) == ' ') ||      \
  47                                 ((flag & VIS_TAB) == 0 && (c) == '\t') ||    \
  48                                 ((flag & VIS_NL) == 0 && (c) == '\n') ||     \
  49                                 ((flag & VIS_SAFE) && ((c) == '\b' ||        \
  50                                 (c) == '\007' || (c) == '\r' ||              \
  51                                 isgraph((u_char)(c)))))
  52
  53 /*
  54  * vis - visually encode characters
  55  */
  56 char *
  57 vis(dst, c, flag, nextc)
  58         register char *dst;
  59         int c, nextc;
  60         register int flag;
  61 {
  62         if (isvisible(c)) {
  63                 *dst++ = c;
  64                 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
  65                         *dst++ = '\\';
  66                 *dst = '\0';
  67                 return (dst);
  68         }
  69
  70         if (flag & VIS_CSTYLE) {
  71                 switch(c) {
  72                 case '\n':
  73                         *dst++ = '\\';
  74                         *dst++ = 'n';
  75                         goto done;
  76                 case '\r':
  77                         *dst++ = '\\';
  78                         *dst++ = 'r';
  79                         goto done;
  80                 case '\b':
  81                         *dst++ = '\\';
  82                         *dst++ = 'b';
  83                         goto done;
  84                 case '\a':
  85                         *dst++ = '\\';
  86                         *dst++ = 'a';
  87                         goto done;
  88                 case '\v':
  89                         *dst++ = '\\';
  90                         *dst++ = 'v';
  91                         goto done;
  92                 case '\t':
  93                         *dst++ = '\\';
  94                         *dst++ = 't';
  95                         goto done;
  96                 case '\f':
  97                         *dst++ = '\\';
  98                         *dst++ = 'f';
  99                         goto done;
 100                 case ' ':
 101                         *dst++ = '\\';
 102                         *dst++ = 's';
 103                         goto done;
 104                 case '\0':
 105                         *dst++ = '\\';
 106                         *dst++ = '0';
 107                         if (isoctal(nextc)) {
 108                                 *dst++ = '0';
 109                                 *dst++ = '0';
 110                         }
 111                         goto done;
 112                 }
 113         }
 114         if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
 115                 *dst++ = '\\';
 116                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 117                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 118                 *dst++ = ((u_char)c & 07) + '0';
 119                 goto done;
 120         }
 121         if ((flag & VIS_NOSLASH) == 0)
 122                 *dst++ = '\\';
 123         if (c & 0200) {
 124                 c &= 0177;
 125                 *dst++ = 'M';
 126         }
 127         if (iscntrl(c)) {
 128                 *dst++ = '^';
 129                 if (c == 0177)
 130                         *dst++ = '?';
 131                 else
 132                         *dst++ = c + '@';
 133         } else {
 134                 *dst++ = '-';
 135                 *dst++ = c;
 136         }
 137 done:
 138         *dst = '\0';
 139         return (dst);
 140 }
 141
 142 /*
 143  * strvis, strnvis, strvisx - visually encode characters from src into dst
 144  *
 145  *      Dst must be 4 times the size of src to account for possible
 146  *      expansion.  The length of dst, not including the trailing NULL,
 147  *      is returned.
 148  *
 149  *      Strnvis will write no more than siz-1 bytes (and will NULL terminate).
 150  *      The number of bytes needed to fully encode the string is returned.
 151  *
 152  *      Strvisx encodes exactly len bytes from src into dst.
 153  *      This is useful for encoding a block of data.
 154  */
 155 int
 156 strvis(dst, src, flag)
 157         register char *dst;
 158         register const char *src;
 159         int flag;
 160 {
 161         register char c;
 162         char *start;
 163
 164         for (start = dst; (c = *src);)
 165                 dst = vis(dst, c, flag, *++src);
 166         *dst = '\0';
 167         return (dst - start);
 168 }
 169
 170 int
 171 strnvis(dst, src, siz, flag)
 172         char *dst;
 173         const char *src;
 174         size_t siz;
 175         int flag;
 176 {
 177         char c;
 178         char *start, *end;
 179         char tbuf[5];
 180         int  i;
 181
 182         i = 0;
 183         for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
 184                 if (isvisible(c)) {
 185                         i = 1;
 186                         *dst++ = c;
 187                         if (c == '\\' && (flag & VIS_NOSLASH) == 0) {
 188                                 /* need space for the extra '\\' */
 189                                 if (dst < end)
 190                                         *dst++ = '\\';
 191                                 else {
 192                                         dst--;
 193                                         i = 2;
 194                                         break;
 195                                 }
 196                         }
 197                         src++;
 198                 } else {
 199                         i = vis(tbuf, c, flag, *++src) - tbuf;
 200                         if (dst + i <= end) {
 201                                 memcpy(dst, tbuf, i);
 202                                 dst += i;
 203                         } else {
 204                                 src--;
 205                                 break;
 206                         }
 207                 }
 208         }
 209         if (siz > 0)
 210                 *dst = '\0';
 211         if (dst + i > end) {
 212                 /* adjust return value for truncation */
 213                 while ((c = *src))
 214                         dst += vis(tbuf, c, flag, *++src) - tbuf;
 215         }
 216         return (dst - start);
 217 }
 218
 219 int
 220 strvisx(dst, src, len, flag)
 221         register char *dst;
 222         register const char *src;
 223         register size_t len;
 224         int flag;
 225 {
 226         register char c;
 227         char *start;
 228
 229         for (start = dst; len > 1; len--) {
 230                 c = *src;
 231                 dst = vis(dst, c, flag, *++src);
 232         }
 233         if (len)
 234                 dst = vis(dst, *src, flag, '\0');
 235         *dst = '\0';
 236         return (dst - start);
 237 }
 238
 239 #endif