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 Clear;
  61 };
  62
  63 /****************************************************************************
  64  Count the entries belonging to a service in the connection db.
  65 ****************************************************************************/
  66
  67 static int count_fn(struct db_record *rec,
  68                     const struct connections_key *ckey,
  69                     const struct connections_data *crec,
  70                     void *udp)
  71 {
  72         struct count_stat *cs = (struct count_stat *)udp;
  73
  74         if (crec->cnum == TID_FIELD_INVALID) {
  75                 return 0;
  76         }
  77
  78         /* If the pid was not found delete the entry from connections.tdb */
  79
  80         if (cs->Clear && !process_exists(crec->pid) && (errno == ESRCH)) {
  81                 NTSTATUS status;
  82                 DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
  83                          procid_str_static(&crec->pid), crec->cnum,
  84                          crec->servicename));
  85
  86                 status = dbwrap_record_delete(rec);
  87                 if (!NT_STATUS_IS_OK(status)) {
  88                         DEBUG(0,("count_fn: tdb_delete failed with error %s\n",
  89                                  nt_errstr(status)));
  90                 }
  91                 return 0;
  92         }
  93
  94         if (strequal(crec->servicename, cs->name))
  95                 cs->curr_connections++;
  96
  97         return 0;
  98 }
  99
 100 /****************************************************************************
 101  Claim an entry in the connections database.
 102 ****************************************************************************/
 103
 104 int count_current_connections( const char *sharename, bool clear  )
 105 {
 106         struct count_stat cs;
 107         int ret;
 108
 109         cs.curr_connections = 0;
 110         cs.name = sharename;
 111         cs.Clear = clear;
 112
 113         /*
 114          * This has a race condition, but locking the chain before hand is worse
 115          * as it leads to deadlock.
 116          */
 117
 118         /*
 119          * become_root() because we might have to open connections.tdb
 120          * via ctdb, which is not possible without root.
 121          */
 122         become_root();
 123         ret = connections_forall(count_fn, &cs);
 124         unbecome_root();
 125
 126         if (ret < 0) {
 127                 DEBUG(0,("count_current_connections: traverse of "
 128                          "connections.tdb failed\n"));
 129                 return 0;
 130         }
 131
 132         return cs.curr_connections;
 133 }
 134
 135 bool connections_snum_used(struct smbd_server_connection *unused, int snum)
 136 {
 137         int active;
 138
 139         active = count_current_connections(lp_servicename(snum), true);
 140         if (active > 0) {
 141                 return true;
 142         }
 143
 144         return false;
 145 }
 146
 147 /****************************************************************************
 148  Claim an entry in the connections database.
 149 ****************************************************************************/
 150
 151 bool claim_connection(connection_struct *conn, const char *name)
 152 {
 153         struct db_record *rec;
 154         struct connections_data crec;
 155         char *raddr;
 156         TDB_DATA dbuf;
 157         NTSTATUS status;
 158
 159         DEBUG(5,("claiming [%s]\n", name));
 160
 161         if (!(rec = connections_fetch_entry(talloc_tos(), conn, name))) {
 162                 DEBUG(0, ("connections_fetch_entry failed\n"));
 163                 return False;
 164         }
 165
 166         /* Make clear that we require the optional unix_token in the source3 code */
 167         SMB_ASSERT(conn->session_info->unix_token);
 168
 169         /* fill in the crec */
 170         ZERO_STRUCT(crec);
 171         crec.magic = 0x280267;
 172         crec.pid = messaging_server_id(conn->sconn->msg_ctx);
 173         crec.cnum = conn->cnum;
 174         crec.uid = conn->session_info->unix_token->uid;
 175         crec.gid = conn->session_info->unix_token->gid;
 176         strlcpy(crec.servicename, lp_servicename(SNUM(conn)),
 177                 sizeof(crec.servicename));
 178         crec.start = time(NULL);
 179
 180         raddr = tsocket_address_inet_addr_string(conn->sconn->remote_address,
 181                                                  talloc_tos());
 182         if (raddr == NULL) {
 183                 return false;
 184         }
 185
 186         strlcpy(crec.machine,get_remote_machine_name(),sizeof(crec.machine));
 187         strlcpy(crec.addr, raddr, sizeof(crec.addr));
 188
 189         dbuf.dptr = (uint8 *)&crec;
 190         dbuf.dsize = sizeof(crec);
 191
 192         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 193
 194         TALLOC_FREE(rec);
 195
 196         if (!NT_STATUS_IS_OK(status)) {
 197                 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
 198                          nt_errstr(status)));
 199                 return False;
 200         }
 201
 202         return True;
 203 }