source3/smbd/connection.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    connection claim routines
   4    Copyright (C) Andrew Tridgell 1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "smbd/smbd.h"
  22 #include "smbd/globals.h"
  23 #include "dbwrap/dbwrap.h"
  24 #include "auth.h"
  25 #include "../lib/tsocket/tsocket.h"
  26 #include "messages.h"
  27 #include "lib/conn_tdb.h"
  28
  29 struct count_stat {
  30         int curr_connections;
  31         const char *name;
  32         bool verify;
  33 };
  34
  35 /****************************************************************************
  36  Count the entries belonging to a service in the connection db.
  37 ****************************************************************************/
  38
  39 static int count_fn(struct smbXsrv_tcon_global0 *tcon,
  40                     void *udp)
  41 {
  42         struct count_stat *cs = (struct count_stat *)udp;
  43
  44         if (cs->verify && !process_exists(tcon->server_id)) {
  45                 return 0;
  46         }
  47
  48         if (strequal(tcon->share_name, cs->name)) {
  49                 cs->curr_connections++;
  50         }
  51
  52         return 0;
  53 }
  54
  55 /****************************************************************************
  56  Claim an entry in the connections database.
  57 ****************************************************************************/
  58
  59 int count_current_connections(const char *sharename, bool verify)
  60 {
  61         struct count_stat cs;
  62         NTSTATUS status;
  63
  64         cs.curr_connections = 0;
  65         cs.name = sharename;
  66         cs.verify = verify;
  67
  68         /*
  69          * This has a race condition, but locking the chain before hand is worse
  70          * as it leads to deadlock.
  71          */
  72
  73         status = smbXsrv_tcon_global_traverse(count_fn, &cs);
  74
  75         if (!NT_STATUS_IS_OK(status)) {
  76                 DEBUG(0,("count_current_connections: traverse of "
  77                          "smbXsrv_tcon_global.tdb failed - %s\n",
  78                          nt_errstr(status)));
  79                 return 0;
  80         }
  81
  82         return cs.curr_connections;
  83 }
  84
  85 bool connections_snum_used(struct smbd_server_connection *unused, int snum)
  86 {
  87         int active;
  88
  89         active = count_current_connections(lp_servicename(talloc_tos(), snum),
  90                                            true);
  91         if (active > 0) {
  92                 return true;
  93         }
  94
  95         return false;
  96 }