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 /****************************************************************************
  29  Delete a connection record.
  30 ****************************************************************************/
  31
  32 bool yield_connection(connection_struct *conn, const char *name)
  33 {
  34         struct db_record *rec;
  35         NTSTATUS status;
  36
  37         DEBUG(3,("Yielding connection to %s\n",name));
  38
  39         rec = connections_fetch_entry(talloc_tos(), conn, name);
  40         if (rec == NULL) {
  41                 DEBUG(0, ("connections_fetch_entry failed\n"));
  42                 return False;
  43         }
  44
  45         status = dbwrap_record_delete(rec);
  46         if (!NT_STATUS_IS_OK(status)) {
  47                 DEBUG( NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND) ? 3 : 0,
  48                        ("deleting connection record returned %s\n",
  49                         nt_errstr(status)));
  50         }
  51
  52         TALLOC_FREE(rec);
  53         return NT_STATUS_IS_OK(status);
  54 }
  55
  56 struct count_stat {
  57         int curr_connections;
  58         const char *name;
  59         bool Clear;
  60 };
  61
  62 /****************************************************************************
  63  Count the entries belonging to a service in the connection db.
  64 ****************************************************************************/
  65
  66 static int count_fn(struct db_record *rec,
  67                     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 == -1) {
  74                 return 0;
  75         }
  76
  77         /* If the pid was not found delete the entry from connections.tdb */
  78
  79         if (cs->Clear && !process_exists(crec->pid) && (errno == ESRCH)) {
  80                 NTSTATUS status;
  81                 DEBUG(2,("pid %s doesn't exist - deleting connections %d [%s]\n",
  82                          procid_str_static(&crec->pid), crec->cnum,
  83                          crec->servicename));
  84
  85                 status = dbwrap_record_delete(rec);
  86                 if (!NT_STATUS_IS_OK(status)) {
  87                         DEBUG(0,("count_fn: tdb_delete failed with error %s\n",
  88                                  nt_errstr(status)));
  89                 }
  90                 return 0;
  91         }
  92
  93         if (strequal(crec->servicename, cs->name))
  94                 cs->curr_connections++;
  95
  96         return 0;
  97 }
  98
  99 /****************************************************************************
 100  Claim an entry in the connections database.
 101 ****************************************************************************/
 102
 103 int count_current_connections( const char *sharename, bool clear  )
 104 {
 105         struct count_stat cs;
 106         int ret;
 107
 108         cs.curr_connections = 0;
 109         cs.name = sharename;
 110         cs.Clear = clear;
 111
 112         /*
 113          * This has a race condition, but locking the chain before hand is worse
 114          * as it leads to deadlock.
 115          */
 116
 117         /*
 118          * become_root() because we might have to open connections.tdb
 119          * via ctdb, which is not possible without root.
 120          */
 121         become_root();
 122         ret = connections_forall(count_fn, &cs);
 123         unbecome_root();
 124
 125         if (ret < 0) {
 126                 DEBUG(0,("count_current_connections: traverse of "
 127                          "connections.tdb failed\n"));
 128                 return 0;
 129         }
 130
 131         return cs.curr_connections;
 132 }
 133
 134 bool connections_snum_used(struct smbd_server_connection *unused, int snum)
 135 {
 136         int active;
 137
 138         active = count_current_connections(lp_servicename(snum), true);
 139         if (active > 0) {
 140                 return true;
 141         }
 142
 143         return false;
 144 }
 145
 146 /****************************************************************************
 147  Claim an entry in the connections database.
 148 ****************************************************************************/
 149
 150 bool claim_connection(connection_struct *conn, const char *name)
 151 {
 152         struct db_record *rec;
 153         struct connections_data crec;
 154         char *raddr;
 155         TDB_DATA dbuf;
 156         NTSTATUS status;
 157
 158         DEBUG(5,("claiming [%s]\n", name));
 159
 160         if (!(rec = connections_fetch_entry(talloc_tos(), conn, name))) {
 161                 DEBUG(0, ("connections_fetch_entry failed\n"));
 162                 return False;
 163         }
 164
 165         /* Make clear that we require the optional unix_token in the source3 code */
 166         SMB_ASSERT(conn->session_info->unix_token);
 167
 168         /* fill in the crec */
 169         ZERO_STRUCT(crec);
 170         crec.magic = 0x280267;
 171         crec.pid = messaging_server_id(conn->sconn->msg_ctx);
 172         crec.cnum = conn->cnum;
 173         crec.uid = conn->session_info->unix_token->uid;
 174         crec.gid = conn->session_info->unix_token->gid;
 175         strlcpy(crec.servicename, lp_servicename(SNUM(conn)),
 176                 sizeof(crec.servicename));
 177         crec.start = time(NULL);
 178
 179         raddr = tsocket_address_inet_addr_string(conn->sconn->remote_address,
 180                                                  talloc_tos());
 181         if (raddr == NULL) {
 182                 return false;
 183         }
 184
 185         strlcpy(crec.machine,get_remote_machine_name(),sizeof(crec.machine));
 186         strlcpy(crec.addr, raddr, sizeof(crec.addr));
 187
 188         dbuf.dptr = (uint8 *)&crec;
 189         dbuf.dsize = sizeof(crec);
 190
 191         status = dbwrap_record_store(rec, dbuf, TDB_REPLACE);
 192
 193         TALLOC_FREE(rec);
 194
 195         if (!NT_STATUS_IS_OK(status)) {
 196                 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
 197                          nt_errstr(status)));
 198                 return False;
 199         }
 200
 201         return True;
 202 }