Line data    Source code

       1             : /*
       2             :    Samba string escaping routines
       3             : 
       4             :    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2017
       5             : 
       6             :    This program is free software; you can redistribute it and/or modify
       7             :    it under the terms of the GNU General Public License as published by
       8             :    the Free Software Foundation; either version 3 of the License, or
       9             :    (at your option) any later version.
      10             : 
      11             :    This program is distributed in the hope that it will be useful,
      12             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             :    GNU General Public License for more details.
      15             : 
      16             :    You should have received a copy of the GNU General Public License
      17             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      18             : */
      19             : 
      20             : #include "replace.h"
      21             : #include "lib/util/debug.h"
      22             : #include "lib/util/util_str_escape.h"
      23             : 
      24             : 
      25             : /*
      26             :  * Calculate the encoded length of a character for log_escape
      27             :  *
      28             :  */
      29        3285 : static size_t encoded_length(unsigned char c)
      30             : {
      31        3285 :         if (c != '\\' &&  c > 0x1F) {
      32        2908 :                 return 1;
      33             :         } else {
      34          11 :                 switch (c) {
      35           0 :                 case '\a':
      36             :                 case '\b':
      37             :                 case '\f':
      38             :                 case '\n':
      39             :                 case '\r':
      40             :                 case '\t':
      41             :                 case '\v':
      42             :                 case '\\':
      43           0 :                         return 2;  /* C escape sequence */
      44           3 :                 default:
      45           3 :                         return 4;  /* hex escape \xhh   */
      46             :                 }
      47             :         }
      48             : }
      49             : 
      50             : /*
      51             :  * Escape any control characters in the inputs to prevent them from
      52             :  * interfering with the log output.
      53             :  */
      54         293 : char *log_escape(TALLOC_CTX *frame, const char *in)
      55             : {
      56         293 :         size_t size = 0;        /* Space to allocate for the escaped data */
      57         293 :         char *encoded = NULL;   /* The encoded string                     */
      58          33 :         const char *c;
      59          33 :         char *e;
      60             : 
      61         293 :         if (in == NULL) {
      62           0 :                 return NULL;
      63             :         }
      64             : 
      65             :         /* Calculate the size required for the escaped array */
      66         260 :         c = in;
      67        3577 :         while (*c) {
      68        3285 :                 size += encoded_length( *c);
      69        3285 :                 c++;
      70             :         }
      71         292 :         size++;
      72             : 
      73         292 :         encoded = talloc_array( frame, char, size);
      74         292 :         if (encoded == NULL) {
      75           0 :                 DBG_ERR( "Out of memory allocating encoded string\n");
      76           0 :                 return NULL;
      77             :         }
      78             : 
      79         260 :         c = in;
      80         260 :         e = encoded;
      81        3577 :         while (*c) {
      82        3285 :                 if (*c != '\\' && (unsigned char)(*c) > 0x1F) {
      83        3274 :                         *e++ = *c++;
      84             :                 } else {
      85          11 :                         switch (*c) {
      86           1 :                         case '\a':
      87           1 :                                 *e++ = '\\';
      88           1 :                                 *e++ = 'a';
      89           1 :                                 break;
      90           1 :                         case '\b':
      91           1 :                                 *e++ = '\\';
      92           1 :                                 *e++ = 'b';
      93           1 :                                 break;
      94           1 :                         case '\f':
      95           1 :                                 *e++ = '\\';
      96           1 :                                 *e++ = 'f';
      97           1 :                                 break;
      98           1 :                         case '\n':
      99           1 :                                 *e++ = '\\';
     100           1 :                                 *e++ = 'n';
     101           1 :                                 break;
     102           1 :                         case '\r':
     103           1 :                                 *e++ = '\\';
     104           1 :                                 *e++ = 'r';
     105           1 :                                 break;
     106           1 :                         case '\t':
     107           1 :                                 *e++ = '\\';
     108           1 :                                 *e++ = 't';
     109           1 :                                 break;
     110           1 :                         case '\v':
     111           1 :                                 *e++ = '\\';
     112           1 :                                 *e++ = 'v';
     113           1 :                                 break;
     114           1 :                         case '\\':
     115           1 :                                 *e++ = '\\';
     116           1 :                                 *e++ = '\\';
     117           1 :                                 break;
     118           3 :                         default:
     119           3 :                                 snprintf(e, 5, "\\x%02hhX", (unsigned char)(*c));
     120           3 :                                 e += 4;
     121             :                         }
     122          11 :                         c++;
     123             :                 }
     124             :         }
     125         292 :         *e = '\0';
     126         292 :         return encoded;
     127             : }