source3/smbd/srvstr.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    server specific string routines
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/smbd.h"
  23 #include "smbd/globals.h"
  24
  25 /* Make sure we can't write a string past the end of the buffer */
  26
  27 size_t srvstr_push_fn(const char *function, unsigned int line,
  28                       const char *base_ptr, uint16 smb_flags2, void *dest,
  29                       const char *src, int dest_len, int flags)
  30 {
  31         if (dest_len < 0) {
  32                 return 0;
  33         }
  34
  35         /* 'normal' push into size-specified buffer */
  36         return push_string_base(function, line, base_ptr, smb_flags2, dest, src,
  37                                 dest_len, flags);
  38 }
  39
  40 /*******************************************************************
  41  Add a string to the end of a smb_buf, adjusting bcc and smb_len.
  42  Return the bytes added
  43 ********************************************************************/
  44
  45 ssize_t message_push_string(uint8 **outbuf, const char *str, int flags)
  46 {
  47         size_t buf_size = smb_len(*outbuf) + 4;
  48         size_t grow_size;
  49         size_t result;
  50         uint8 *tmp;
  51
  52         /*
  53          * We need to over-allocate, now knowing what srvstr_push will
  54          * actually use. This is very generous by incorporating potential
  55          * padding, the terminating 0 and at most 4 chars per UTF-16 code
  56          * point.
  57          */
  58         grow_size = (strlen(str) + 2) * 4;
  59
  60         if (!(tmp = TALLOC_REALLOC_ARRAY(NULL, *outbuf, uint8,
  61                                          buf_size + grow_size))) {
  62                 DEBUG(0, ("talloc failed\n"));
  63                 return -1;
  64         }
  65
  66         result = srvstr_push((char *)tmp, SVAL(tmp, smb_flg2),
  67                              tmp + buf_size, str, grow_size, flags);
  68
  69         if (result == (size_t)-1) {
  70                 DEBUG(0, ("srvstr_push failed\n"));
  71                 return -1;
  72         }
  73         set_message_bcc((char *)tmp, smb_buflen(tmp) + result);
  74
  75         *outbuf = tmp;
  76
  77         return result;
  78 }