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         dos_to_unix(key.name, True);           /* Convert key to unix-codepage */
  57
  58         kbuf.dptr = (char *)&key;
  59         kbuf.dsize = sizeof(key);
  60
  61         tdb_delete(tdb, kbuf);
  62
  63         return(True);
  64 }
  65
  66 struct count_stat {
  67         pid_t mypid;
  68         int curr_connections;
  69         char *name;
  70         BOOL Clear;
  71 };
  72
  73 /****************************************************************************
  74  Count the entries belonging to a service in the connection db.
  75 ****************************************************************************/
  76
  77 static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
  78 {
  79         struct connections_data crec;
  80         struct count_stat *cs = (struct count_stat *)udp;
  81
  82         if (dbuf.dsize != sizeof(crec))
  83                 return 0;
  84
  85         memcpy(&crec, dbuf.dptr, sizeof(crec));
  86
  87         if (crec.cnum == -1)
  88                 return 0;
  89
  90         /* if the pid was not found delete the entry from connections.tdb */
  91         if (cs->Clear && !process_exists(crec.pid)) {
  92                 DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
  93                         (unsigned int)crec.pid, crec.cnum, crec.name));
  94                 tdb_delete(the_tdb, kbuf);
  95                 return 0;
  96         }
  97
  98         if (cs && strequal(crec.name, cs->name))
  99                 cs->curr_connections++;
 100
 101         return 0;
 102 }
 103
 104 /****************************************************************************
 105  Claim an entry in the connections database.
 106 ****************************************************************************/
 107
 108 BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
 109 {
 110         struct connections_key key;
 111         struct connections_data crec;
 112         TDB_DATA kbuf, dbuf;
 113
 114         if (!tdb) {
 115                 tdb = tdb_open(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST,
 116                                O_RDWR | O_CREAT, 0644);
 117         }
 118         if (!tdb)
 119                 return False;
 120
 121         /*
 122          * Enforce the max connections parameter.
 123          */
 124
 125         if (max_connections > 0) {
 126                 struct count_stat cs;
 127
 128                 cs.mypid = sys_getpid();
 129                 cs.curr_connections = 0;
 130                 cs.name = lp_servicename(SNUM(conn));
 131                 cs.Clear = Clear;
 132
 133                 /*
 134                  * Go through and count the connections
 135                  */
 136                 if (tdb_traverse(tdb, count_fn, &cs) == -1) {
 137                         DEBUG(0,("claim_connection: traverse of connections.tdb failed.\n"));
 138                         return False;
 139                 }
 140
 141                 if (cs.curr_connections >= max_connections) {
 142                         DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
 143                                 max_connections, name ));
 144                         return False;
 145                 }
 146         }
 147
 148         DEBUG(5,("claiming %s %d\n",name,max_connections));
 149
 150         ZERO_STRUCT(key);
 151         key.pid = sys_getpid();
 152         key.cnum = conn?conn->cnum:-1;
 153         fstrcpy(key.name, name);
 154         dos_to_unix(key.name, True);           /* Convert key to unix-codepage */
 155
 156         kbuf.dptr = (char *)&key;
 157         kbuf.dsize = sizeof(key);
 158
 159         /* fill in the crec */
 160         ZERO_STRUCT(crec);
 161         crec.magic = 0x280267;
 162         crec.pid = sys_getpid();
 163         crec.cnum = conn?conn->cnum:-1;
 164         if (conn) {
 165                 crec.uid = conn->uid;
 166                 crec.gid = conn->gid;
 167                 StrnCpy(crec.name,
 168                         lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
 169         }
 170         crec.start = time(NULL);
 171
 172         StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
 173         StrnCpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
 174
 175         dbuf.dptr = (char *)&crec;
 176         dbuf.dsize = sizeof(crec);
 177
 178         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0)
 179                 return False;
 180
 181         return True;
 182 }
 183
 184 #if 0
 185 /****************************************************************************
 186  Use the count function to clean any dead records. Shouldn't be needed...
 187 ****************************************************************************/
 188
 189 void clean_connection_db(void)
 190 {
 191         if (tdb_traverse(tdb, count_fn, NULL) == -1)
 192                 DEBUG(0,("clean_connection_db: traverse of connections.tdb failed.\n"));
 193 }
 194 #endif