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 NTSTATUS srvstr_push_fn(const char *base_ptr, uint16_t smb_flags2, void *dest,
  28                       const char *src, int dest_len, int flags, size_t *ret_len)
  29 {
  30         size_t len;
  31         int saved_errno;
  32         NTSTATUS status;
  33
  34         if (dest_len < 0) {
  35                 return NT_STATUS_INVALID_PARAMETER;
  36         }
  37
  38         saved_errno = errno;
  39         errno = 0;
  40
  41         /* 'normal' push into size-specified buffer */
  42         len = push_string_base(base_ptr, smb_flags2, dest, src,
  43                                 dest_len, flags);
  44
  45         if (errno != 0) {
  46                 /*
  47                  * Special case E2BIG, EILSEQ, EINVAL
  48                  * as they mean conversion errors here,
  49                  * but we don't generically map them as
  50                  * they can mean different things in
  51                  * generic filesystem calls (such as
  52                  * read xattrs).
  53                  */
  54                 if (errno == E2BIG || errno == EILSEQ || errno == EINVAL) {
  55                         status = NT_STATUS_ILLEGAL_CHARACTER;
  56                 } else {
  57                         status = map_nt_error_from_unix_common(errno);
  58                         /*
  59                          * Paranoia - Filter out STATUS_MORE_ENTRIES.
  60                          * I don't think we can get this but it has a
  61                          * specific meaning to the client.
  62                          */
  63                         if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
  64                                 status = NT_STATUS_UNSUCCESSFUL;
  65                         }
  66                 }
  67                 DEBUG(10,("character conversion failure "
  68                         "on string (%s) (%s)\n",
  69                         src, strerror(errno)));
  70         } else {
  71                 /* Success - restore untouched errno. */
  72                 errno = saved_errno;
  73                 *ret_len = len;
  74                 status = NT_STATUS_OK;
  75         }
  76         return status;
  77 }
  78
  79 /*******************************************************************
  80  Add a string to the end of a smb_buf, adjusting bcc and smb_len.
  81  Return the bytes added
  82 ********************************************************************/
  83
  84 ssize_t message_push_string(uint8_t **outbuf, const char *str, int flags)
  85 {
  86         size_t buf_size = smb_len(*outbuf) + 4;
  87         size_t grow_size;
  88         size_t result = 0;
  89         uint8_t *tmp;
  90         NTSTATUS status;
  91
  92         /*
  93          * We need to over-allocate, now knowing what srvstr_push will
  94          * actually use. This is very generous by incorporating potential
  95          * padding, the terminating 0 and at most 4 chars per UTF-16 code
  96          * point.
  97          */
  98         grow_size = (strlen(str) + 2) * 4;
  99
 100         if (!(tmp = talloc_realloc(NULL, *outbuf, uint8_t,
 101                                          buf_size + grow_size))) {
 102                 DEBUG(0, ("talloc failed\n"));
 103                 return -1;
 104         }
 105
 106         status = srvstr_push((char *)tmp, SVAL(tmp, smb_flg2),
 107                              tmp + buf_size, str, grow_size, flags, &result);
 108
 109         if (!NT_STATUS_IS_OK(status)) {
 110                 DEBUG(0, ("srvstr_push failed\n"));
 111                 return -1;
 112         }
 113         set_message_bcc((char *)tmp, smb_buflen(tmp) + result);
 114
 115         *outbuf = tmp;
 116
 117         return result;
 118 }