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.h"
  24 #include "auth.h"
  25
  26 /****************************************************************************
  27  Delete a connection record.
  28 ****************************************************************************/
  29
  30 bool yield_connection(connection_struct *conn, const char *name)
  31 {
  32         struct db_record *rec;
  33         NTSTATUS status;
  34
  35         DEBUG(3,("Yielding connection to %s\n",name));
  36
  37         rec = connections_fetch_entry(talloc_tos(), conn, name);
  38         if (rec == NULL) {
  39                 DEBUG(0, ("connections_fetch_entry failed\n"));
  40                 return False;
  41         }
  42
  43         status = rec->delete_rec(rec);
  44         if (!NT_STATUS_IS_OK(status)) {
  45                 DEBUG( NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND) ? 3 : 0,
  46                        ("deleting connection record returned %s\n",
  47                         nt_errstr(status)));
  48         }
  49
  50         TALLOC_FREE(rec);
  51         return NT_STATUS_IS_OK(status);
  52 }
  53
  54 struct count_stat {
  55         int curr_connections;
  56         const char *name;
  57         bool Clear;
  58 };
  59
  60 /****************************************************************************
  61  Count the entries belonging to a service in the connection db.
  62 ****************************************************************************/
  63
  64 static int count_fn(struct db_record *rec,
  65                     const struct connections_key *ckey,
  66                     const struct connections_data *crec,
  67                     void *udp)
  68 {
  69         struct count_stat *cs = (struct count_stat *)udp;
  70
  71         if (crec->cnum == -1) {
  72                 return 0;
  73         }
  74
  75         /* If the pid was not found delete the entry from connections.tdb */
  76
  77         if (cs->Clear && !process_exists(crec->pid) && (errno == ESRCH)) {
  78                 NTSTATUS status;
  79                 DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
  80                          procid_str_static(&crec->pid), crec->cnum,
  81                          crec->servicename));
  82
  83                 status = rec->delete_rec(rec);
  84                 if (!NT_STATUS_IS_OK(status)) {
  85                         DEBUG(0,("count_fn: tdb_delete failed with error %s\n",
  86                                  nt_errstr(status)));
  87                 }
  88                 return 0;
  89         }
  90
  91         if (strequal(crec->servicename, cs->name))
  92                 cs->curr_connections++;
  93
  94         return 0;
  95 }
  96
  97 /****************************************************************************
  98  Claim an entry in the connections database.
  99 ****************************************************************************/
 100
 101 int count_current_connections( const char *sharename, bool clear  )
 102 {
 103         struct count_stat cs;
 104         int ret;
 105
 106         cs.curr_connections = 0;
 107         cs.name = sharename;
 108         cs.Clear = clear;
 109
 110         /*
 111          * This has a race condition, but locking the chain before hand is worse
 112          * as it leads to deadlock.
 113          */
 114
 115         /*
 116          * become_root() because we might have to open connections.tdb
 117          * via ctdb, which is not possible without root.
 118          */
 119         become_root();
 120         ret = connections_forall(count_fn, &cs);
 121         unbecome_root();
 122
 123         if (ret < 0) {
 124                 DEBUG(0,("count_current_connections: traverse of "
 125                          "connections.tdb failed\n"));
 126                 return 0;
 127         }
 128
 129         return cs.curr_connections;
 130 }
 131
 132 /****************************************************************************
 133  Claim an entry in the connections database.
 134 ****************************************************************************/
 135
 136 bool claim_connection(connection_struct *conn, const char *name)
 137 {
 138         struct db_record *rec;
 139         struct connections_data crec;
 140         TDB_DATA dbuf;
 141         NTSTATUS status;
 142
 143         DEBUG(5,("claiming [%s]\n", name));
 144
 145         if (!(rec = connections_fetch_entry(talloc_tos(), conn, name))) {
 146                 DEBUG(0, ("connections_fetch_entry failed\n"));
 147                 return False;
 148         }
 149
 150         /* fill in the crec */
 151         ZERO_STRUCT(crec);
 152         crec.magic = 0x280267;
 153         crec.pid = sconn_server_id(conn->sconn);
 154         crec.cnum = conn->cnum;
 155         crec.uid = conn->session_info->utok.uid;
 156         crec.gid = conn->session_info->utok.gid;
 157         strlcpy(crec.servicename, lp_servicename(SNUM(conn)),
 158                 sizeof(crec.servicename));
 159         crec.start = time(NULL);
 160
 161         strlcpy(crec.machine,get_remote_machine_name(),sizeof(crec.machine));
 162         strlcpy(crec.addr, conn->sconn->client_id.addr, sizeof(crec.addr));
 163
 164         dbuf.dptr = (uint8 *)&crec;
 165         dbuf.dsize = sizeof(crec);
 166
 167         status = rec->store(rec, dbuf, TDB_REPLACE);
 168
 169         TALLOC_FREE(rec);
 170
 171         if (!NT_STATUS_IS_OK(status)) {
 172                 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
 173                          nt_errstr(status)));
 174                 return False;
 175         }
 176
 177         return True;
 178 }