contrib/sendmail/libsm/util.c

   1 /*
   2  * Copyright (c) 2006 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  *
   5  * By using this file, you agree to the terms and conditions set
   6  * forth in the LICENSE file which can be found at the top level of
   7  * the sendmail distribution.
   8  *
   9  */
  10
  11 #include <sm/gen.h>
  12
  13 SM_RCSID("@(#)$Id: util.c,v 1.9 2006/08/30 18:35:51 ca Exp $")
  14 #include <sm/setjmp.h>
  15 #include <sm/conf.h>
  16 #include <sm/assert.h>
  17 #include <sm/heap.h>
  18 #include <sm/string.h>
  19 #include <sm/sendmail.h>
  20 #include <ctype.h>
  21
  22 /*
  23 **  STR2PRT -- convert "unprintable" characters in a string to \oct
  24 **
  25 **      Parameters:
  26 **              s -- string to convert
  27 **
  28 **      Returns:
  29 **              converted string.
  30 **              This is a static local buffer, string must be copied
  31 **              before this function is called again!
  32 */
  33
  34 char *
  35 str2prt(s)
  36         char *s;
  37 {
  38         int l;
  39         char c, *h;
  40         bool ok;
  41         static int len = 0;
  42         static char *buf = NULL;
  43
  44         if (s == NULL)
  45                 return NULL;
  46         ok = true;
  47         for (h = s, l = 1; *h != '\0'; h++, l++)
  48         {
  49                 if (*h == '\\')
  50                 {
  51                         ++l;
  52                         ok = false;
  53                 }
  54                 else if (!(isascii(*h) && isprint(*h)))
  55                 {
  56                         l += 3;
  57                         ok = false;
  58                 }
  59         }
  60         if (ok)
  61                 return s;
  62         if (l > len)
  63         {
  64                 char *nbuf = sm_pmalloc_x(l);
  65
  66                 if (buf != NULL)
  67                         sm_free(buf);
  68                 len = l;
  69                 buf = nbuf;
  70         }
  71         for (h = buf; *s != '\0' && l > 0; s++, l--)
  72         {
  73                 c = *s;
  74                 if (isascii(c) && isprint(c) && c != '\\')
  75                 {
  76                         *h++ = c;
  77                 }
  78                 else
  79                 {
  80                         *h++ = '\\';
  81                         --l;
  82                         switch (c)
  83                         {
  84                           case '\\':
  85                                 *h++ = '\\';
  86                                 break;
  87                           case '\t':
  88                                 *h++ = 't';
  89                                 break;
  90                           case '\n':
  91                                 *h++ = 'n';
  92                                 break;
  93                           case '\r':
  94                                 *h++ = 'r';
  95                                 break;
  96                           default:
  97                                 SM_ASSERT(l >= 2);
  98                                 (void) sm_snprintf(h, l, "%03o",
  99                                         (unsigned int)((unsigned char) c));
 100
 101                                 /*
 102                                 **  XXX since l is unsigned this may
 103                                 **  wrap around if the calculation is screwed
 104                                 **  up...
 105                                 */
 106
 107                                 l -= 2;
 108                                 h += 3;
 109                                 break;
 110                         }
 111                 }
 112         }
 113         *h = '\0';
 114         buf[len - 1] = '\0';
 115         return buf;
 116 }
 117
 118 /*
 119 **  QUOTE_INTERNAL_CHARS -- do quoting of internal characters
 120 **
 121 **      Necessary to make sure that we don't have metacharacters such
 122 **      as the internal versions of "$*" or "$&" in a string.
 123 **      The input and output pointers can be the same.
 124 **
 125 **      Parameters:
 126 **              ibp -- a pointer to the string to translate
 127 **              obp -- a pointer to an output buffer
 128 **              bsp -- pointer to the length of the output buffer
 129 **
 130 **      Returns:
 131 **              A possibly new bp (if the buffer needed to grow); if
 132 **              it is different, *bsp will updated to the size of
 133 **              the new buffer and the caller is responsible for
 134 **              freeing the memory.
 135 */
 136
 137 #define SM_MM_QUOTE(ch) (((ch) & 0377) == METAQUOTE || (((ch) & 0340) == 0200))
 138
 139 char *
 140 quote_internal_chars(ibp, obp, bsp)
 141         char *ibp;
 142         char *obp;
 143         int *bsp;
 144 {
 145         char *ip, *op;
 146         int bufused, olen;
 147         bool buffer_same, needs_quoting;
 148
 149         buffer_same = ibp == obp;
 150         needs_quoting = false;
 151
 152         /* determine length of output string (starts at 1 for trailing '\0') */
 153         for (ip = ibp, olen = 1; *ip != '\0'; ip++, olen++)
 154         {
 155                 if (SM_MM_QUOTE(*ip))
 156                 {
 157                         olen++;
 158                         needs_quoting = true;
 159                 }
 160         }
 161
 162         /* is the output buffer big enough? */
 163         if (olen > *bsp)
 164         {
 165                 obp = sm_malloc_x(olen);
 166                 buffer_same = false;
 167                 *bsp = olen;
 168         }
 169
 170         /*
 171         **  shortcut: no change needed?
 172         **  Note: we don't check this first as some bozo may use the same
 173         **  buffers but restrict the size of the output buffer to less
 174         **  than the length of the input buffer in which case we need to
 175         **  allocate a new buffer.
 176         */
 177
 178         if (!needs_quoting)
 179         {
 180                 if (!buffer_same)
 181                 {
 182                         bufused = sm_strlcpy(obp, ibp, *bsp);
 183                         SM_ASSERT(bufused <= olen);
 184                 }
 185                 return obp;
 186         }
 187
 188         if (buffer_same)
 189         {
 190                 obp = sm_malloc_x(olen);
 191                 buffer_same = false;
 192                 *bsp = olen;
 193         }
 194
 195         for (ip = ibp, op = obp, bufused = 0; *ip != '\0'; ip++)
 196         {
 197                 if (SM_MM_QUOTE(*ip))
 198                 {
 199                         SM_ASSERT(bufused < olen);
 200                         op[bufused++] = METAQUOTE;
 201                 }
 202                 SM_ASSERT(bufused < olen);
 203                 op[bufused++] = *ip;
 204         }
 205         op[bufused] = '\0';
 206         return obp;
 207 }
 208
 209 /*
 210 **  DEQUOTE_INTERNAL_CHARS -- undo the effect of quote_internal_chars
 211 **
 212 **      Parameters:
 213 **              ibp -- a pointer to the string to be translated.
 214 **              obp -- a pointer to the output buffer.  Can be the
 215 **                      same as ibp.
 216 **              obs -- the size of the output buffer.
 217 **
 218 **      Returns:
 219 **              number of character added to obp
 220 */
 221
 222 int
 223 dequote_internal_chars(ibp, obp, obs)
 224         char *ibp;
 225         char *obp;
 226         int obs;
 227 {
 228         char *ip, *op;
 229         int len;
 230         bool quoted;
 231
 232         quoted = false;
 233         len = 0;
 234         for (ip = ibp, op = obp; *ip != '\0'; ip++)
 235         {
 236                 if ((*ip & 0377) == METAQUOTE && !quoted)
 237                 {
 238                         quoted = true;
 239                         continue;
 240                 }
 241                 if (op < &obp[obs - 1])
 242                 {
 243                         *op++ = *ip;
 244                         ++len;
 245                 }
 246                 quoted = false;
 247         }
 248         *op = '\0';
 249         return len;
 250 }