ctdb-tcp: Close inflight connecting TCP sockets after fork

Commit c68b6f9 changed the talloc hierarchy such that outgoing TCP sockets
while sitting in the async connect() syscall are not freed via
ctdb_tcp_shutdown() anymore, they are hanging off a longer-running structure.
Free this structure as well.

If an outgoing TCP socket leaks into a long-running child process (possibly the
recovery daemon), this connection will never be closed as seen by the
destination node. Because with recent changes incoming connections will not be
accepted as long as any incoming connection is alive, with that socket leak
into the recovery daemon we will never again be able to successfully connect to
the node that is affected by this leak. Further attempts to connect will be
discarded by the destination as long as the recovery daemon keeps this socket
alive.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14175
RN: Avoid communication breakdown on node reconnect

Signed-off-by: Martin Schwenke <[email protected]>
Signed-off-by: Volker Lendecke <[email protected]>
Reviewed-by: Amitay Isaacs <[email protected]>

ctdb/tcp/tcp_init.c

@@ -137,8 +137,14 @@ static void ctdb_tcp_shutdown(struct ctdb_context *ctdb)
 {
 	struct ctdb_tcp *ctcp = talloc_get_type(ctdb->private_data,
 						struct ctdb_tcp);
+	uint32_t i;
+
 	talloc_free(ctcp);
 	ctdb->private_data = NULL;
+
+	for (i=0; i<ctdb->num_nodes; i++) {
+		TALLOC_FREE(ctdb->nodes[i]->private_data);
+	}
 }
 
 /*