2 Unix SMB/Netbios implementation.
4 connection claim routines
5 Copyright (C) Andrew Tridgell 1998
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.
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.
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.
25 extern fstring remote_machine;
26 static TDB_CONTEXT *tdb;
28 extern int DEBUGLEVEL;
30 /****************************************************************************
31 Return the connection tdb context (used for message send all).
32 ****************************************************************************/
34 TDB_CONTEXT *conn_tdb_ctx(void)
39 /****************************************************************************
40 Delete a connection record.
41 ****************************************************************************/
43 BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
45 struct connections_key key;
48 if (!tdb) return False;
50 DEBUG(3,("Yielding connection to %s\n",name));
53 key.pid = sys_getpid();
54 key.cnum = conn?conn->cnum:-1;
55 fstrcpy(key.name, name);
57 kbuf.dptr = (char *)&key;
58 kbuf.dsize = sizeof(key);
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) ));
76 /****************************************************************************
77 Count the entries belonging to a service in the connection db.
78 ****************************************************************************/
80 static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
82 struct connections_data crec;
83 struct count_stat *cs = (struct count_stat *)udp;
85 if (dbuf.dsize != sizeof(crec))
88 memcpy(&crec, dbuf.dptr, sizeof(crec));
93 /* If the pid was not found delete the entry from connections.tdb */
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) ));
103 if (strequal(crec.name, cs->name))
104 cs->curr_connections++;
109 /****************************************************************************
110 Claim an entry in the connections database.
111 ****************************************************************************/
113 BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
115 struct connections_key key;
116 struct connections_data crec;
120 tdb = tdb_open_log(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
121 O_RDWR | O_CREAT, 0644);
127 * Enforce the max connections parameter.
130 if (max_connections > 0) {
131 struct count_stat cs;
133 cs.mypid = sys_getpid();
134 cs.curr_connections = 0;
135 cs.name = lp_servicename(SNUM(conn));
139 * This has a race condition, but locking the chain before hand is worse
140 * as it leads to deadlock.
143 if (tdb_traverse(tdb, count_fn, &cs) == -1) {
144 DEBUG(0,("claim_connection: traverse of connections.tdb failed with error %s.\n",
145 tdb_errorstr(tdb) ));
149 if (cs.curr_connections >= max_connections) {
150 DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
151 max_connections, name ));
156 DEBUG(5,("claiming %s %d\n",name,max_connections));
159 key.pid = sys_getpid();
160 key.cnum = conn?conn->cnum:-1;
161 fstrcpy(key.name, name);
163 kbuf.dptr = (char *)&key;
164 kbuf.dsize = sizeof(key);
166 /* fill in the crec */
168 crec.magic = 0x280267;
169 crec.pid = sys_getpid();
170 crec.cnum = conn?conn->cnum:-1;
172 crec.uid = conn->uid;
173 crec.gid = conn->gid;
175 lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
177 crec.start = time(NULL);
179 StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
180 StrnCpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
182 dbuf.dptr = (char *)&crec;
183 dbuf.dsize = sizeof(crec);
185 if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
186 DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
187 tdb_errorstr(tdb) ));