crypto/openssh/openbsd-compat/vis.c

   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