source3/smbd/connection.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    connection claim routines
   5    Copyright (C) Andrew Tridgell 1998
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24
  25 extern fstring remote_machine;
  26 static TDB_CONTEXT *tdb;
  27
  28 extern int DEBUGLEVEL;
  29
  30 /****************************************************************************
  31  Return the connection tdb context (used for message send all).
  32 ****************************************************************************/
  33
  34 TDB_CONTEXT *conn_tdb_ctx(void)
  35 {
  36         return tdb;
  37 }
  38
  39 /****************************************************************************
  40  Delete a connection record.
  41 ****************************************************************************/
  42
  43 BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
  44 {
  45         struct connections_key key;
  46         TDB_DATA kbuf;
  47
  48         if (!tdb) return False;
  49
  50         DEBUG(3,("Yielding connection to %s\n",name));
  51
  52         ZERO_STRUCT(key);
  53         key.pid = sys_getpid();
  54         key.cnum = conn?conn->cnum:-1;
  55         fstrcpy(key.name, name);
  56
  57         kbuf.dptr = (char *)&key;
  58         kbuf.dsize = sizeof(key);
  59
  60         if (tdb_delete(tdb, kbuf) != 0) {
  61                 DEBUG(0,("yield_connection: tdb_delete for name %s failed with error %s.\n",
  62                                 name, tdb_errorstr(tdb) ));
  63                 return (False);
  64         }
  65
  66         return(True);
  67 }
  68
  69 struct count_stat {
  70         pid_t mypid;
  71         int curr_connections;
  72         char *name;
  73         BOOL Clear;
  74 };
  75
  76 /****************************************************************************
  77  Count the entries belonging to a service in the connection db.
  78 ****************************************************************************/
  79
  80 static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
  81 {
  82         struct connections_data crec;
  83         struct count_stat *cs = (struct count_stat *)udp;
  84
  85         if (dbuf.dsize != sizeof(crec))
  86                 return 0;
  87
  88         memcpy(&crec, dbuf.dptr, sizeof(crec));
  89
  90     if (crec.cnum == -1)
  91                 return 0;
  92
  93         /* If the pid was not found delete the entry from connections.tdb */
  94
  95         if (cs->Clear && !process_exists(crec.pid) && (errno == ESRCH)) {
  96                 DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
  97                         (unsigned int)crec.pid, crec.cnum, crec.name));
  98                 if (tdb_delete(the_tdb, kbuf) != 0)
  99                         DEBUG(0,("count_fn: tdb_delete failed with error %s\n", tdb_errorstr(tdb) ));
 100                 return 0;
 101         }
 102
 103         if (strequal(crec.name, cs->name))
 104                 cs->curr_connections++;
 105
 106         return 0;
 107 }
 108
 109 /****************************************************************************
 110  Claim an entry in the connections database.
 111 ****************************************************************************/
 112
 113 BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
 114 {
 115         struct connections_key key;
 116         struct connections_data crec;
 117         TDB_DATA kbuf, dbuf;
 118         BOOL ret = True;
 119
 120         if (!tdb) {
 121                 tdb = tdb_open_log(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
 122                                O_RDWR | O_CREAT, 0644);
 123         }
 124         if (!tdb)
 125                 return False;
 126
 127         /*
 128          * Enforce the max connections parameter.
 129          */
 130
 131         if (max_connections > 0) {
 132                 struct count_stat cs;
 133
 134                 cs.mypid = sys_getpid();
 135                 cs.curr_connections = 0;
 136                 cs.name = lp_servicename(SNUM(conn));
 137                 cs.Clear = Clear;
 138
 139                 if (tdb_traverse(tdb, count_fn, &cs) == -1) {
 140                         DEBUG(0,("claim_connection: traverse of connections.tdb failed with error %s.\n",
 141                                 tdb_errorstr(tdb) ));
 142                         ret = False;
 143                         goto out;
 144                 }
 145
 146                 if (cs.curr_connections >= max_connections) {
 147                         DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
 148                                 max_connections, name ));
 149                         ret = False;
 150                         goto out;
 151                 }
 152         }
 153
 154         DEBUG(5,("claiming %s %d\n",name,max_connections));
 155
 156         ZERO_STRUCT(key);
 157         key.pid = sys_getpid();
 158         key.cnum = conn?conn->cnum:-1;
 159         fstrcpy(key.name, name);
 160
 161         kbuf.dptr = (char *)&key;
 162         kbuf.dsize = sizeof(key);
 163
 164         /* fill in the crec */
 165         ZERO_STRUCT(crec);
 166         crec.magic = 0x280267;
 167         crec.pid = sys_getpid();
 168         crec.cnum = conn?conn->cnum:-1;
 169         if (conn) {
 170                 crec.uid = conn->uid;
 171                 crec.gid = conn->gid;
 172                 StrnCpy(crec.name,
 173                         lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
 174         }
 175         crec.start = time(NULL);
 176
 177         StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
 178         StrnCpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
 179
 180         dbuf.dptr = (char *)&crec;
 181         dbuf.dsize = sizeof(crec);
 182
 183         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
 184                 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
 185                         tdb_errorstr(tdb) ));
 186                 ret = False;
 187         }
 188
 189   out:
 190
 191         return ret;
 192 }