tipc: clean up socket timer function

The last remaining BH upcall to the socket, apart for the message
reception function tipc_sk_rcv(), is the timer function.

We prefer to let this function continue executing in BH, since it only
does read-acces to semi-permanent data, but we make three changes to it:

1) We introduce a bh_lock_sock()/bh_unlock_sock() inside the scope
   of port_lock.  This is a preparation for replacing port_lock with
   bh_lock_sock() at the locations where it is still used.

2) We move the function from port.c to socket.c, as a further step
   of eliminating the port code level altogether.

3) We let it make use of the newly introduced tipc_msg_create()
   function. This enables us to get rid of three context specific
   functions (port_create_self_abort_msg() etc.) in port.c

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index a8be4d2..5f8376e 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -53,6 +53,7 @@
 static int tipc_release(struct socket *sock);
 static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags);
 static int tipc_wait_for_sndmsg(struct socket *sock, long *timeo_p);
+static void tipc_sk_timeout(unsigned long ref);
 
 static const struct proto_ops packet_ops;
 static const struct proto_ops stream_ops;
@@ -202,6 +203,7 @@
 	sock->state = state;
 
 	sock_init_data(sock, sk);
+	k_init_timer(&port->timer, (Handler)tipc_sk_timeout, ref);
 	sk->sk_backlog_rcv = tipc_backlog_rcv;
 	sk->sk_rcvbuf = sysctl_tipc_rmem[1];
 	sk->sk_data_ready = tipc_data_ready;
@@ -1946,6 +1948,50 @@
 	return res;
 }
 
+static void tipc_sk_timeout(unsigned long ref)
+{
+	struct tipc_port *port = tipc_port_lock(ref);
+	struct tipc_sock *tsk;
+	struct sock *sk;
+	struct sk_buff *buf = NULL;
+	struct tipc_msg *msg = NULL;
+	u32 peer_port, peer_node;
+
+	if (!port)
+		return;
+
+	if (!port->connected) {
+		tipc_port_unlock(port);
+		return;
+	}
+	tsk = tipc_port_to_sock(port);
+	sk = &tsk->sk;
+	bh_lock_sock(sk);
+	peer_port = tipc_port_peerport(port);
+	peer_node = tipc_port_peernode(port);
+
+	if (port->probing_state == TIPC_CONN_PROBING) {
+		/* Previous probe not answered -> self abort */
+		buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
+				      SHORT_H_SIZE, 0, tipc_own_addr,
+				      peer_node, ref, peer_port,
+				      TIPC_ERR_NO_PORT);
+	} else {
+		buf = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE,
+				      0, peer_node, tipc_own_addr,
+				      peer_port, ref, TIPC_OK);
+		port->probing_state = TIPC_CONN_PROBING;
+		k_start_timer(&port->timer, port->probing_interval);
+	}
+	bh_unlock_sock(sk);
+	tipc_port_unlock(port);
+	if (!buf)
+		return;
+
+	msg = buf_msg(buf);
+	tipc_link_xmit(buf, msg_destnode(msg),	msg_link_selector(msg));
+}
+
 /**
  * tipc_setsockopt - set socket option
  * @sock: socket structure