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
  28 struct count_stat {
  29         int curr_connections;
  30         const char *name;
  31         bool verify;
  32 };
  33
  34 /****************************************************************************
  35  Count the entries belonging to a service in the connection db.
  36 ****************************************************************************/
  37
  38 static int count_fn(struct smbXsrv_tcon_global0 *tcon,
  39                     void *udp)
  40 {
  41         struct count_stat *cs = (struct count_stat *)udp;
  42
  43         if (cs->verify && !process_exists(tcon->server_id)) {
  44                 return 0;
  45         }
  46
  47         if (strequal(tcon->share_name, cs->name)) {
  48                 cs->curr_connections++;
  49         }
  50
  51         return 0;
  52 }
  53
  54 /****************************************************************************
  55  Claim an entry in the connections database.
  56 ****************************************************************************/
  57
  58 int count_current_connections(const char *sharename, bool verify)
  59 {
  60         struct count_stat cs;
  61         NTSTATUS status;
  62
  63         cs.curr_connections = 0;
  64         cs.name = sharename;
  65         cs.verify = verify;
  66
  67         /*
  68          * This has a race condition, but locking the chain before hand is worse
  69          * as it leads to deadlock.
  70          */
  71
  72         status = smbXsrv_tcon_global_traverse(count_fn, &cs);
  73
  74         if (!NT_STATUS_IS_OK(status)) {
  75                 DEBUG(0,("count_current_connections: traverse of "
  76                          "smbXsrv_tcon_global.tdb failed - %s\n",
  77                          nt_errstr(status)));
  78                 return 0;
  79         }
  80
  81         return cs.curr_connections;
  82 }
  83
  84 bool connections_snum_used(struct smbd_server_connection *unused, int snum)
  85 {
  86         const struct loadparm_substitution *lp_sub =
  87                 loadparm_s3_global_substitution();
  88         int active;
  89
  90         active = count_current_connections(lp_servicename(talloc_tos(), lp_sub, snum),
  91                                            true);
  92         if (active > 0) {
  93                 return true;
  94         }
  95
  96         return false;
  97 }