source/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 };
  71
  72 /****************************************************************************
  73  Count the entries belonging to a service in the connection db.
  74 ****************************************************************************/
  75
  76 static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
  77 {
  78         struct connections_data crec;
  79         struct count_stat *cs = (struct count_stat *)udp;
  80
  81         memcpy(&crec, dbuf.dptr, sizeof(crec));
  82
  83     if (crec.cnum == -1)
  84                 return 0;
  85
  86         /* if the pid was not found delete the entry from connections.tdb */
  87         if (!process_exists(crec.pid) && (errno == ESRCH)) {
  88                 DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
  89                         (unsigned int)crec.pid, crec.cnum, crec.name));
  90                 tdb_delete(the_tdb, kbuf);
  91                 return 0;
  92         }
  93
  94         if (cs && strequal(crec.name, cs->name))
  95                 cs->curr_connections++;
  96
  97         return 0;
  98 }
  99
 100 /****************************************************************************
 101  Claim an entry in the connections database.
 102 ****************************************************************************/
 103
 104 BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
 105 {
 106         struct connections_key key;
 107         struct connections_data crec;
 108         TDB_DATA kbuf, dbuf;
 109         BOOL db_locked = False;
 110         BOOL ret = True;
 111
 112         if (!tdb) {
 113                 tdb = tdb_open(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST,
 114                                O_RDWR | O_CREAT, 0644);
 115         }
 116         if (!tdb)
 117                 return False;
 118
 119         /*
 120          * Enforce the max connections parameter.
 121          */
 122
 123         if (max_connections > 0) {
 124                 struct count_stat cs;
 125
 126                 cs.mypid = sys_getpid();
 127                 cs.curr_connections = 0;
 128                 cs.name = lp_servicename(SNUM(conn));
 129
 130                 /*
 131                  * Go through and count the connections with the db locked. This is
 132                  * slow but essentially what 2.0.x did. JRA.
 133                  */
 134
 135                 if (tdb_lockall(tdb))
 136                         return False;
 137
 138                 db_locked = True;
 139
 140                 if (tdb_traverse(tdb, count_fn, &cs) == -1) {
 141                         DEBUG(0,("claim_connection: traverse of connections.tdb failed.\n"));
 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         dos_to_unix(key.name, True);           /* Convert key to unix-codepage */
 161
 162         kbuf.dptr = (char *)&key;
 163         kbuf.dsize = sizeof(key);
 164
 165         /* fill in the crec */
 166         ZERO_STRUCT(crec);
 167         crec.magic = 0x280267;
 168         crec.pid = sys_getpid();
 169         crec.cnum = conn?conn->cnum:-1;
 170         if (conn) {
 171                 crec.uid = conn->uid;
 172                 crec.gid = conn->gid;
 173                 StrnCpy(crec.name,
 174                         lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
 175         }
 176         crec.start = time(NULL);
 177
 178         StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
 179         StrnCpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
 180
 181         dbuf.dptr = (char *)&crec;
 182         dbuf.dsize = sizeof(crec);
 183
 184         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0)
 185                 ret = False;
 186
 187   out:
 188
 189         if (db_locked)
 190                 tdb_unlockall(tdb);
 191
 192         return ret;
 193 }
 194
 195 #if 0
 196 /****************************************************************************
 197  Use the count function to clean any dead records. Shouldn't be needed...
 198 ****************************************************************************/
 199
 200 void clean_connection_db(void)
 201 {
 202         if (tdb_traverse(tdb, count_fn, NULL) == -1)
 203                 DEBUG(0,("clean_connection_db: traverse of connections.tdb failed.\n"));
 204 }
 205 #endif