source: vendor/3.6.23/source3/smbd/srvstr.c

/* 
   Unix SMB/CIFS implementation.
   server specific string routines
   Copyright (C) Andrew Tridgell 2001
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"

/* Make sure we can't write a string past the end of the buffer */

size_t srvstr_push_fn(const char *function, unsigned int line,
                      const char *base_ptr, uint16 smb_flags2, void *dest,
                      const char *src, int dest_len, int flags)
{
        if (dest_len < 0) {
                return 0;
        }

        /* 'normal' push into size-specified buffer */
        return push_string_base(function, line, base_ptr, smb_flags2, dest, src,
                                dest_len, flags);
}

/*******************************************************************
 Add a string to the end of a smb_buf, adjusting bcc and smb_len.
 Return the bytes added
********************************************************************/

ssize_t message_push_string(uint8 **outbuf, const char *str, int flags)
{
        size_t buf_size = smb_len(*outbuf) + 4;
        size_t grow_size;
        size_t result;
        uint8 *tmp;

        /*
         * We need to over-allocate, now knowing what srvstr_push will
         * actually use. This is very generous by incorporating potential
         * padding, the terminating 0 and at most 4 chars per UTF-16 code
         * point.
         */
        grow_size = (strlen(str) + 2) * 4;

        if (!(tmp = TALLOC_REALLOC_ARRAY(NULL, *outbuf, uint8,
                                         buf_size + grow_size))) {
                DEBUG(0, ("talloc failed\n"));
                return -1;
        }

        result = srvstr_push((char *)tmp, SVAL(tmp, smb_flg2),
                             tmp + buf_size, str, grow_size, flags);

        if (result == (size_t)-1) {
                DEBUG(0, ("srvstr_push failed\n"));
                return -1;
        }
        set_message_bcc((char *)tmp, smb_buflen(tmp) + result);

        *outbuf = tmp;

        return result;
}