source: vendor/current/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 */

NTSTATUS srvstr_push_fn(const char *base_ptr, uint16_t smb_flags2, void *dest,
                      const char *src, int dest_len, int flags, size_t *ret_len)
{
        size_t len;
        int saved_errno;
        NTSTATUS status;

        if (dest_len < 0) {
                return NT_STATUS_INVALID_PARAMETER;
        }

        saved_errno = errno;
        errno = 0;

        /* 'normal' push into size-specified buffer */
        len = push_string_base(base_ptr, smb_flags2, dest, src,
                                dest_len, flags);

        if (errno != 0) {
                /*
                 * Special case E2BIG, EILSEQ, EINVAL
                 * as they mean conversion errors here,
                 * but we don't generically map them as
                 * they can mean different things in
                 * generic filesystem calls (such as
                 * read xattrs).
                 */
                if (errno == E2BIG || errno == EILSEQ || errno == EINVAL) {
                        status = NT_STATUS_ILLEGAL_CHARACTER;
                } else {
                        status = map_nt_error_from_unix_common(errno);
                        /*
                         * Paranoia - Filter out STATUS_MORE_ENTRIES.
                         * I don't think we can get this but it has a
                         * specific meaning to the client.
                         */
                        if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
                                status = NT_STATUS_UNSUCCESSFUL;
                        }
                }
                DEBUG(10,("character conversion failure "
                        "on string (%s) (%s)\n",
                        src, strerror(errno)));
        } else {
                /* Success - restore untouched errno. */
                errno = saved_errno;
                *ret_len = len;
                status = NT_STATUS_OK;
        }
        return status;
}

/*******************************************************************
 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_t **outbuf, const char *str, int flags)
{
        size_t buf_size = smb_len(*outbuf) + 4;
        size_t grow_size;
        size_t result = 0;
        uint8_t *tmp;
        NTSTATUS status;

        /*
         * 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(NULL, *outbuf, uint8_t,
                                         buf_size + grow_size))) {
                DEBUG(0, ("talloc failed\n"));
                return -1;
        }

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

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

        *outbuf = tmp;

        return result;
}