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 *base_ptr, uint16 smb_flags2, void *dest,
  28                       const char *src, int dest_len, int flags)
  29 {
  30         if (dest_len < 0) {
  31                 return 0;
  32         }
  33
  34         /* 'normal' push into size-specified buffer */
  35         return push_string_base(base_ptr, smb_flags2, dest, src,
  36                                 dest_len, flags);
  37 }
  38
  39 /*******************************************************************
  40  Add a string to the end of a smb_buf, adjusting bcc and smb_len.
  41  Return the bytes added
  42 ********************************************************************/
  43
  44 ssize_t message_push_string(uint8 **outbuf, const char *str, int flags)
  45 {
  46         size_t buf_size = smb_len(*outbuf) + 4;
  47         size_t grow_size;
  48         size_t result;
  49         uint8 *tmp;
  50
  51         /*
  52          * We need to over-allocate, now knowing what srvstr_push will
  53          * actually use. This is very generous by incorporating potential
  54          * padding, the terminating 0 and at most 4 chars per UTF-16 code
  55          * point.
  56          */
  57         grow_size = (strlen(str) + 2) * 4;
  58
  59         if (!(tmp = talloc_realloc(NULL, *outbuf, uint8,
  60                                          buf_size + grow_size))) {
  61                 DEBUG(0, ("talloc failed\n"));
  62                 return -1;
  63         }
  64
  65         result = srvstr_push((char *)tmp, SVAL(tmp, smb_flg2),
  66                              tmp + buf_size, str, grow_size, flags);
  67
  68         if (result == (size_t)-1) {
  69                 DEBUG(0, ("srvstr_push failed\n"));
  70                 return -1;
  71         }
  72         set_message_bcc((char *)tmp, smb_buflen(tmp) + result);
  73
  74         *outbuf = tmp;
  75
  76         return result;
  77 }