source3/smbd/smb1_utils.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  * Util functions valid in the SMB1 server
   4  *
   5  * Copyright (C) Volker Lendecke 2019
   6  * Copyright by the authors of the functions moved here eventually
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 3 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "includes.h"
  23 #include "libcli/security/security.h"
  24 #include "lib/util/sys_rw_data.h"
  25 #include "smbd/fd_handle.h"
  26
  27 /****************************************************************************
  28  Special FCB or DOS processing in the case of a sharing violation.
  29  Try and find a duplicated file handle.
  30 ****************************************************************************/
  31
  32 struct files_struct *fcb_or_dos_open(
  33         struct smb_request *req,
  34         const struct smb_filename *smb_fname,
  35         uint32_t access_mask,
  36         uint32_t create_options,
  37         uint32_t private_flags)
  38 {
  39         struct connection_struct *conn = req->conn;
  40         struct file_id id = vfs_file_id_from_sbuf(conn, &smb_fname->st);
  41         struct files_struct *fsp = NULL, *new_fsp = NULL;
  42         NTSTATUS status;
  43
  44         if ((private_flags &
  45              (NTCREATEX_FLAG_DENY_DOS|
  46               NTCREATEX_FLAG_DENY_FCB))
  47             == 0) {
  48                 return NULL;
  49         }
  50
  51         for(fsp = file_find_di_first(conn->sconn, id, true);
  52             fsp != NULL;
  53             fsp = file_find_di_next(fsp, true)) {
  54
  55                 DBG_DEBUG("Checking file %s, fd = %d, vuid = %"PRIu64", "
  56                           "file_pid = %"PRIu16", "
  57                           "private_options = 0x%"PRIx32", "
  58                           "access_mask = 0x%"PRIx32"\n",
  59                           fsp_str_dbg(fsp),
  60                           fsp_get_pathref_fd(fsp),
  61                           fsp->vuid,
  62                           fsp->file_pid,
  63                           fh_get_private_options(fsp->fh),
  64                           fsp->access_mask);
  65
  66                 if (fsp_get_pathref_fd(fsp) != -1 &&
  67                     fsp->vuid == req->vuid &&
  68                     fsp->file_pid == req->smbpid &&
  69                     (fh_get_private_options(fsp->fh) &
  70                      (NTCREATEX_FLAG_DENY_DOS |
  71                       NTCREATEX_FLAG_DENY_FCB)) &&
  72                     (fsp->access_mask & FILE_WRITE_DATA) &&
  73                     strequal(fsp->fsp_name->base_name, smb_fname->base_name) &&
  74                     strequal(fsp->fsp_name->stream_name,
  75                              smb_fname->stream_name)) {
  76                         DBG_DEBUG("file match\n");
  77                         break;
  78                 }
  79         }
  80
  81         if (fsp == NULL) {
  82                 return NULL;
  83         }
  84
  85         /* quite an insane set of semantics ... */
  86         if (is_executable(smb_fname->base_name) &&
  87             (fh_get_private_options(fsp->fh) & NTCREATEX_FLAG_DENY_DOS)) {
  88                 DBG_DEBUG("file fail due to is_executable.\n");
  89                 return NULL;
  90         }
  91
  92         status = file_new(req, conn, &new_fsp);
  93         if (!NT_STATUS_IS_OK(status)) {
  94                 DBG_DEBUG("file_new failed: %s\n", nt_errstr(status));
  95                 return NULL;
  96         }
  97
  98         status = dup_file_fsp(
  99                 req,
 100                 fsp,
 101                 access_mask,
 102                 create_options,
 103                 new_fsp);
 104
 105         if (!NT_STATUS_IS_OK(status)) {
 106                 DBG_DEBUG("dup_file_fsp failed: %s\n", nt_errstr(status));
 107                 file_free(req, new_fsp);
 108                 return NULL;
 109         }
 110
 111         return new_fsp;
 112 }
 113
 114 /****************************************************************************
 115  Send a keepalive packet (rfc1002).
 116 ****************************************************************************/
 117
 118 bool send_keepalive(int client)
 119 {
 120         unsigned char buf[4];
 121
 122         buf[0] = NBSSkeepalive;
 123         buf[1] = buf[2] = buf[3] = 0;
 124
 125         return(write_data(client,(char *)buf,4) == 4);
 126 }