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/*
Unix SMB/Netbios implementation.
Version 1.9.
connection claim routines
Copyright (C) Andrew Tridgell 1998
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
extern fstring remote_machine;
static TDB_CONTEXT *tdb;
/****************************************************************************
Return the connection tdb context (used for message send all).
****************************************************************************/
TDB_CONTEXT *conn_tdb_ctx(void)
{
return tdb;
}
/****************************************************************************
Delete a connection record.
****************************************************************************/
BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
{
struct connections_key key;
TDB_DATA kbuf;
if (!tdb) return False;
DEBUG(3,("Yielding connection to %s\n",name));
ZERO_STRUCT(key);
key.pid = sys_getpid();
key.cnum = conn?conn->cnum:-1;
fstrcpy(key.name, name);
kbuf.dptr = (char *)&key;
kbuf.dsize = sizeof(key);
if (tdb_delete(tdb, kbuf) != 0) {
DEBUG(0,("yield_connection: tdb_delete for name %s failed with error %s.\n",
name, tdb_errorstr(tdb) ));
return (False);
}
return(True);
}
struct count_stat {
pid_t mypid;
int curr_connections;
char *name;
BOOL Clear;
};
/****************************************************************************
Count the entries belonging to a service in the connection db.
****************************************************************************/
static int count_fn( TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, void *udp)
{
struct connections_data crec;
struct count_stat *cs = (struct count_stat *)udp;
if (dbuf.dsize != sizeof(crec))
return 0;
memcpy(&crec, dbuf.dptr, sizeof(crec));
if (crec.cnum == -1)
return 0;
/* If the pid was not found delete the entry from connections.tdb */
if (cs->Clear && !process_exists(crec.pid) && (errno == ESRCH)) {
DEBUG(2,("pid %u doesn't exist - deleting connections %d [%s]\n",
(unsigned int)crec.pid, crec.cnum, crec.name));
if (tdb_delete(the_tdb, kbuf) != 0)
DEBUG(0,("count_fn: tdb_delete failed with error %s\n", tdb_errorstr(tdb) ));
return 0;
}
if (strequal(crec.name, cs->name))
cs->curr_connections++;
return 0;
}
/****************************************************************************
Claim an entry in the connections database.
****************************************************************************/
BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
{
struct connections_key key;
struct connections_data crec;
TDB_DATA kbuf, dbuf;
if (!tdb) {
tdb = tdb_open_log(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
O_RDWR | O_CREAT, 0644);
}
if (!tdb)
return False;
/*
* Enforce the max connections parameter.
*/
if (max_connections > 0) {
struct count_stat cs;
cs.mypid = sys_getpid();
cs.curr_connections = 0;
cs.name = lp_servicename(SNUM(conn));
cs.Clear = Clear;
/*
* This has a race condition, but locking the chain before hand is worse
* as it leads to deadlock.
*/
if (tdb_traverse(tdb, count_fn, &cs) == -1) {
DEBUG(0,("claim_connection: traverse of connections.tdb failed with error %s.\n",
tdb_errorstr(tdb) ));
return False;
}
if (cs.curr_connections >= max_connections) {
DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
max_connections, name ));
return False;
}
}
DEBUG(5,("claiming %s %d\n",name,max_connections));
ZERO_STRUCT(key);
key.pid = sys_getpid();
key.cnum = conn?conn->cnum:-1;
fstrcpy(key.name, name);
kbuf.dptr = (char *)&key;
kbuf.dsize = sizeof(key);
/* fill in the crec */
ZERO_STRUCT(crec);
crec.magic = 0x280267;
crec.pid = sys_getpid();
crec.cnum = conn?conn->cnum:-1;
if (conn) {
crec.uid = conn->uid;
crec.gid = conn->gid;
StrnCpy(crec.name,
lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
}
crec.start = time(NULL);
StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
StrnCpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
dbuf.dptr = (char *)&crec;
dbuf.dsize = sizeof(crec);
if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) {
DEBUG(0,("claim_connection: tdb_store failed with error %s.\n",
tdb_errorstr(tdb) ));
return False;
}
return True;
}
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