From 363e378dee1677f865bba3e8b347c600bbc08550 Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Mon, 14 May 2001 06:15:46 +0000
Subject: Implemented max connections in a similar way to 2.0.x (scan of
 connection db). This needs testing ! Tidied up tabs in tdb.c. Jeremy. (This
 used to be commit 0852465053d0c1a23b6cfe6097267291b0595ef8)

---
 source3/smbd/connection.c | 88 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 83 insertions(+), 5 deletions(-)

(limited to 'source3/smbd/connection.c')

diff --git a/source3/smbd/connection.c b/source3/smbd/connection.c
index 43e89abfbf..6c401264d9 100644
--- a/source3/smbd/connection.c
+++ b/source3/smbd/connection.c
@@ -37,8 +37,9 @@ TDB_CONTEXT *conn_tdb_ctx(void)
 }
 
 /****************************************************************************
-delete a connection record
+ Delete a connection record.
 ****************************************************************************/
+
 BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
 {
 	struct connections_key key;
@@ -62,21 +63,92 @@ BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
 	return(True);
 }
 
+struct count_stat {
+	pid_t mypid;
+	int curr_connections;
+	char *name;
+};
+
+/****************************************************************************
+ 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;
+ 
+	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 (!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));
+		tdb_delete(the_tdb, kbuf);
+		return 0;
+	}
+
+	if (strequal(crec.name, cs->name))
+		cs->curr_connections++;
+
+	return 0;
+}
 
 /****************************************************************************
-claim an entry in the connections database
+ 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;
+	BOOL db_locked = False;
+	BOOL ret = True;
 
 	if (!tdb) {
 		tdb = tdb_open(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST, 
 			       O_RDWR | O_CREAT, 0644);
 	}
-	if (!tdb) return False;
+	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));
+
+		/*
+		 * Go through and count the connections with the db locked. This is
+		 * slow but essentially what 2.0.x did. JRA.
+		 */
+
+		if (tdb_lockall(tdb))
+			return False;
+
+		db_locked = True;
+
+		if (tdb_traverse(tdb, count_fn, &cs)) {
+			ret = False;
+			goto out;
+		}
+
+		if (cs.curr_connections >= max_connections) {
+			DEBUG(1,("claim_connection: Max connections (%d) exceeded for %s\n",
+				max_connections, name ));
+			ret = False;
+			goto out;
+		}
+	}
 
 	DEBUG(5,("claiming %s %d\n",name,max_connections));
 
@@ -108,8 +180,14 @@ BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOO
 	dbuf.dptr = (char *)&crec;
 	dbuf.dsize = sizeof(crec);
 
-	if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) return False;
+	if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0)
+		ret = False;
+
+  out:
+
+	if (db_locked)
+		tdb_unlockall(tdb);
 
-	return True;
+	return ret;
 }
 
-- 
cgit