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 /****************************************************************************
  30  Delete a connection record.
  31 ****************************************************************************/
  32
  33 bool yield_connection(connection_struct *conn, const char *name)
  34 {
  35         struct db_record *rec;
  36         NTSTATUS status;
  37
  38         DEBUG(3,("Yielding connection to %s\n",name));
  39
  40         rec = connections_fetch_entry(talloc_tos(), conn, name);
  41         if (rec == NULL) {
  42                 DEBUG(0, ("connections_fetch_entry failed\n"));
  43                 return False;
  44         }
  45
  46         status = dbwrap_record_delete(rec);
  47         if (!NT_STATUS_IS_OK(status)) {
  48                 DEBUG( NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND) ? 3 : 0,
  49                        ("deleting connection record returned %s\n",
  50                         nt_errstr(status)));
  51         }
  52
  53         TALLOC_FREE(rec);
  54         return NT_STATUS_IS_OK(status);
  55 }
  56
  57 struct count_stat {
  58         int curr_connections;
  59         const char *name;
  60         bool verify;
  61 };
  62
  63 /****************************************************************************
  64  Count the entries belonging to a service in the connection db.
  65 ****************************************************************************/
  66
  67 static int count_fn(const struct connections_key *ckey,
  68                     const struct connections_data *crec,
  69                     void *udp)
  70 {
  71         struct count_stat *cs = (struct count_stat *)udp;
  72
  73         if (crec->cnum == TID_FIELD_INVALID) {
  74                 return 0;
  75         }
  76
  77         if (cs->verify && !process_exists(crec->pid)) {
  78                 return 0;
  79         }
  80
  81         if (strequal(crec->servicename, cs->name)) {
  82                 cs->curr_connections++;
  83         }
  84
  85         return 0;
  86 }
  87
  88 /****************************************************************************
  89  Claim an entry in the connections database.
  90 ****************************************************************************/
  91
  92 int count_current_connections(const char *sharename, bool verify)
  93 {
  94         struct count_stat cs;
  95         int ret;
  96
  97         cs.curr_connections = 0;
  98         cs.name = sharename;
  99         cs.verify = verify;
 100
 101         /*
 102          * This has a race condition, but locking the chain before hand is worse
 103          * as it leads to deadlock.
 104          */
 105
 106         /*
 107          * become_root() because we might have to open connections.tdb
 108          * via ctdb, which is not possible without root.
 109          */
 110         become_root();
 111         ret = connections_forall_read(count_fn, &cs);
 112         unbecome_root();
 113
 114         if (ret < 0) {
 115                 DEBUG(0,("count_current_connections: traverse of "
 116                          "connections.tdb failed\n"));
 117                 return 0;
 118         }
 119
 120         return cs.curr_connections;
 121 }
 122
 123 bool connections_snum_used(struct smbd_server_connection *unused, int snum)
 124 {
 125         int active;
 126
 127         active = count_current_connections(lp_servicename(talloc_tos(), snum),
 128                                            true);
 129         if (active > 0) {
 130                 return true;
 131         }
 132
 133         return false;
 134 }
 135
 136 /****************************************************************************
 137  Claim an entry in the connections database.
 138 ****************************************************************************/
 139
 140 bool claim_connection(connection_struct *conn, const char *name)
 141 {
 142         struct db_record *rec;
 143         struct connections_data crec;
 144         char *raddr;
 145         TDB_DATA dbuf;
 146         NTSTATUS status;
 147
 148         DEBUG(5,("claiming [%s]\n", name));
 149
 150         if (!(rec = connections_fetch_entry(talloc_tos(), conn, name))) {
 151                 DEBUG(0, ("connections_fetch_entry failed\n"));
 152                 return False;
 153         }
 154
 155         /* Make clear that we require the optional unix_token in the source3 code */
 156         SMB_ASSERT(conn->session_info->unix_token);
 157
 158         /* fill in the crec */
 159         ZERO_STRUCT(crec);
 160         crec.magic = 0x280267;
 161         crec.pid = messaging_server_id(conn->sconn->msg_ctx);
 162         crec.cnum = conn->cnum;
 163         crec.uid = conn->session_info->unix_token->uid;
 164         crec.gid = conn->session_info->unix_token->gid;
 165         strlcpy(crec.servicename, lp_servicename(rec, SNUM(conn)),
 166                 sizeof(crec.servicename));
 167         crec.start = time(NULL);
 168
 169         raddr = tsocket_address_inet_addr_string(conn->sconn->remote_address,
 170                                                  rec);
 171         if (raddr == NULL) {
 172                 return false;
 173         }
 174
 175         strlcpy(crec.machine,get_remote_machine_name(),sizeof(crec.machine));
 176         strlcpy(crec.addr, raddr, sizeof(crec.addr));
 177
 178         dbuf.dptr = (uint8 *)&crec;
 179         dbuf.dsize = sizeof(crec);
 180
 181         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 182
 183         TALLOC_FREE(rec);
 184
 185         if (!NT_STATUS_IS_OK(status)) {
 186                 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
 187                          nt_errstr(status)));
 188                 return False;
 189         }
 190
 191         return True;
 192 }