tipc: eliminate port_connect()/port_disconnect() functions

tipc_port_connect()/tipc_port_disconnect() are remnants of the obsolete
native API. Their only task is to grab port_lock and call the functions
__tipc_port_connect()/__tipc_port_disconnect() respectively, which will
perform the actual state change.

Since socket/port exection now is single-threaded the use of port_lock
is not needed any more, so we can safely replace the two functions with
their lock-free counterparts.

In this commit, we remove the two functions. Furthermore, the contents
of __tipc_port_disconnect() is so trivial that we choose to eliminate
that function too, expanding its functionality into tipc_shutdown().
__tipc_port_connect() is simplified, moved to socket.c, and given the
more correct name tipc_sk_finish_conn(). Finally, we eliminate the
function auto_connect(), and expand its contents into filter_connect().

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>

3 files changed, 37 insertions, 132 deletions

diff --git a/net/tipc/port.c b/net/tipc/port.c
index 3ad092b7fb7d..2f96719a3514 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -40,9 +40,6 @@
 #include "name_table.h"
 #include "socket.h"
 
-/* Connection management: */
-#define PROBING_INTERVAL 3600000        /* [ms] => 1 h */
-
 #define MAX_REJECT_SIZE 1024
 
 DEFINE_SPINLOCK(tipc_port_list_lock);
@@ -304,84 +301,3 @@ int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
                 p_ptr->published = 0;
         return res;
 }
-
-int tipc_port_connect(u32 ref, struct tipc_portid const *peer)
-{
-        struct tipc_port *p_ptr;
-        int res;
-
-        p_ptr = tipc_port_lock(ref);
-        if (!p_ptr)
-                return -EINVAL;
-        res = __tipc_port_connect(ref, p_ptr, peer);
-        tipc_port_unlock(p_ptr);
-        return res;
-}
-
-/*
- * __tipc_port_connect - connect to a remote peer
- *
- * Port must be locked.
- */
-int __tipc_port_connect(u32 ref, struct tipc_port *p_ptr,
-                        struct tipc_portid const *peer)
-{
-        struct tipc_msg *msg;
-        int res = -EINVAL;
-
-        if (p_ptr->published || p_ptr->connected)
-                goto exit;
-        if (!peer->ref)
-                goto exit;
-
-        msg = &p_ptr->phdr;
-        msg_set_destnode(msg, peer->node);
-        msg_set_destport(msg, peer->ref);
-        msg_set_type(msg, TIPC_CONN_MSG);
-        msg_set_lookup_scope(msg, 0);
-        msg_set_hdr_sz(msg, SHORT_H_SIZE);
-
-        p_ptr->probing_interval = PROBING_INTERVAL;
-        p_ptr->probing_state = TIPC_CONN_OK;
-        p_ptr->connected = 1;
-        k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
-        res = tipc_node_add_conn(tipc_port_peernode(p_ptr), p_ptr->ref,
-                                 tipc_port_peerport(p_ptr));
-exit:
-        p_ptr->max_pkt = tipc_node_get_mtu(peer->node, ref);
-        return res;
-}
-
-/*
- * __tipc_disconnect - disconnect port from peer
- *
- * Port must be locked.
- */
-int __tipc_port_disconnect(struct tipc_port *tp_ptr)
-{
-        if (tp_ptr->connected) {
-                tp_ptr->connected = 0;
-                /* let timer expire on it's own to avoid deadlock! */
-                tipc_node_remove_conn(tipc_port_peernode(tp_ptr), tp_ptr->ref);
-                return 0;
-        }
-
-        return -ENOTCONN;
-}
-
-/*
- * tipc_port_disconnect(): Disconnect port form peer.
- *                    This is a node local operation.
- */
-int tipc_port_disconnect(u32 ref)
-{
-        struct tipc_port *p_ptr;
-        int res;
-
-        p_ptr = tipc_port_lock(ref);
-        if (!p_ptr)
-                return -EINVAL;
-        res = __tipc_port_disconnect(p_ptr);
-        tipc_port_unlock(p_ptr);
-        return res;
-}
diff --git a/net/tipc/port.h b/net/tipc/port.h
index f5762f940e33..b356cb8340d9 100644
--- a/net/tipc/port.h
+++ b/net/tipc/port.h
@@ -102,16 +102,6 @@ int tipc_publish(struct tipc_port *p_ptr, unsigned int scope,
 int tipc_withdraw(struct tipc_port *p_ptr, unsigned int scope,
                   struct tipc_name_seq const *name_seq);
 
-int tipc_port_connect(u32 portref, struct tipc_portid const *port);
-
-int tipc_port_disconnect(u32 portref);
-
-/*
- * The following routines require that the port be locked on entry
- */
-int __tipc_port_disconnect(struct tipc_port *tp_ptr);
-int __tipc_port_connect(u32 ref, struct tipc_port *p_ptr,
-                   struct tipc_portid const *peer);
 int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg);
 
 struct sk_buff *tipc_port_get_ports(void);
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index f202d4790ce3..a65105818fe5 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -45,6 +45,7 @@
 #define SS_READY        -2      /* socket is connectionless */
 
 #define CONN_TIMEOUT_DEFAULT    8000    /* default connect timeout = 8s */
+#define CONN_PROBING_INTERVAL 3600000   /* [ms] => 1 h */
 #define TIPC_FWD_MSG            1
 
 static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb);
@@ -339,7 +340,9 @@ static int tipc_release(struct socket *sock)
                         if ((sock->state == SS_CONNECTING) ||
                             (sock->state == SS_CONNECTED)) {
                                 sock->state = SS_DISCONNECTING;
-                                tipc_port_disconnect(port->ref);
+                                port->connected = 0;
+                                tipc_node_remove_conn(tipc_port_peernode(port),
+                                                      port->ref);
                         }
                         if (tipc_msg_reverse(buf, &dnode, TIPC_ERR_NO_PORT))
                                 tipc_link_xmit(buf, dnode, 0);
@@ -988,29 +991,25 @@ static int tipc_send_packet(struct kiocb *iocb, struct socket *sock,
         return tipc_send_stream(iocb, sock, m, dsz);
 }
 
-/**
- * auto_connect - complete connection setup to a remote port
- * @tsk: tipc socket structure
- * @msg: peer's response message
- *
- * Returns 0 on success, errno otherwise
+/* tipc_sk_finish_conn - complete the setup of a connection
  */
-static int auto_connect(struct tipc_sock *tsk, struct tipc_msg *msg)
+static void tipc_sk_finish_conn(struct tipc_port *port, u32 peer_port,
+                                u32 peer_node)
 {
-        struct tipc_port *port = &tsk->port;
-        struct socket *sock = tsk->sk.sk_socket;
-        struct tipc_portid peer;
-
-        peer.ref = msg_origport(msg);
-        peer.node = msg_orignode(msg);
+        struct tipc_msg *msg = &port->phdr;
 
-        __tipc_port_connect(port->ref, port, &peer);
+        msg_set_destnode(msg, peer_node);
+        msg_set_destport(msg, peer_port);
+        msg_set_type(msg, TIPC_CONN_MSG);
+        msg_set_lookup_scope(msg, 0);
+        msg_set_hdr_sz(msg, SHORT_H_SIZE);
 
-        if (msg_importance(msg) > TIPC_CRITICAL_IMPORTANCE)
-                return -EINVAL;
-        msg_set_importance(&port->phdr, (u32)msg_importance(msg));
-        sock->state = SS_CONNECTED;
-        return 0;
+        port->probing_interval = CONN_PROBING_INTERVAL;
+        port->probing_state = TIPC_CONN_OK;
+        port->connected = 1;
+        k_start_timer(&port->timer, port->probing_interval);
+        tipc_node_add_conn(peer_node, port->ref, peer_port);
+        port->max_pkt = tipc_node_get_mtu(peer_node, port->ref);
 }
 
 /**
@@ -1405,7 +1404,6 @@ static int filter_connect(struct tipc_sock *tsk, struct sk_buff **buf)
         struct tipc_msg *msg = buf_msg(*buf);
 
         int retval = -TIPC_ERR_NO_PORT;
-        int res;
 
         if (msg_mcast(msg))
                 return retval;
@@ -1416,13 +1414,20 @@ static int filter_connect(struct tipc_sock *tsk, struct sk_buff **buf)
                 if (msg_connected(msg) && tipc_port_peer_msg(port, msg)) {
                         if (unlikely(msg_errcode(msg))) {
                                 sock->state = SS_DISCONNECTING;
-                                __tipc_port_disconnect(port);
+                                port->connected = 0;
+                                /* let timer expire on it's own */
+                                tipc_node_remove_conn(tipc_port_peernode(port),
+                                                      port->ref);
                         }
                         retval = TIPC_OK;
                 }
                 break;
         case SS_CONNECTING:
                 /* Accept only ACK or NACK message */
+
+                if (unlikely(!msg_connected(msg)))
+                        break;
+
                 if (unlikely(msg_errcode(msg))) {
                         sock->state = SS_DISCONNECTING;
                         sk->sk_err = ECONNREFUSED;
@@ -1430,17 +1435,17 @@ static int filter_connect(struct tipc_sock *tsk, struct sk_buff **buf)
                         break;
                 }
 
-                if (unlikely(!msg_connected(msg)))
-                        break;
-
-                res = auto_connect(tsk, msg);
-                if (res) {
+                if (unlikely(msg_importance(msg) > TIPC_CRITICAL_IMPORTANCE)) {
                         sock->state = SS_DISCONNECTING;
-                        sk->sk_err = -res;
+                        sk->sk_err = EINVAL;
                         retval = TIPC_OK;
                         break;
                 }
 
+                tipc_sk_finish_conn(port, msg_origport(msg), msg_orignode(msg));
+                msg_set_importance(&port->phdr, msg_importance(msg));
+                sock->state = SS_CONNECTED;
+
                 /* If an incoming message is an 'ACK-', it should be
                  * discarded here because it doesn't contain useful
                  * data. In addition, we should try to wake up
@@ -1816,8 +1821,6 @@ static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags)
         struct sk_buff *buf;
         struct tipc_port *new_port;
         struct tipc_msg *msg;
-        struct tipc_portid peer;
-        u32 new_ref;
         long timeo;
         int res;
 
@@ -1840,7 +1843,6 @@ static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags)
 
         new_sk = new_sock->sk;
         new_port = &tipc_sk(new_sk)->port;
-        new_ref = new_port->ref;
         msg = buf_msg(buf);
 
         /* we lock on new_sk; but lockdep sees the lock on sk */
@@ -1853,9 +1855,7 @@ static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags)
         reject_rx_queue(new_sk);
 
         /* Connect new socket to it's peer */
-        peer.ref = msg_origport(msg);
-        peer.node = msg_orignode(msg);
-        tipc_port_connect(new_ref, &peer);
+        tipc_sk_finish_conn(new_port, msg_origport(msg), msg_orignode(msg));
         new_sock->state = SS_CONNECTED;
 
         tipc_port_set_importance(new_port, msg_importance(msg));
@@ -1919,9 +1919,9 @@ restart:
                                 kfree_skb(buf);
                                 goto restart;
                         }
-                        tipc_port_disconnect(port->ref);
                         if (tipc_msg_reverse(buf, &dnode, TIPC_CONN_SHUTDOWN))
                                 tipc_link_xmit(buf, dnode, port->ref);
+                        tipc_node_remove_conn(dnode, port->ref);
                 } else {
                         dnode = tipc_port_peernode(port);
                         buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
@@ -1930,11 +1930,10 @@ restart:
                                               tipc_port_peerport(port),
                                               port->ref, TIPC_CONN_SHUTDOWN);
                         tipc_link_xmit(buf, dnode, port->ref);
-                        __tipc_port_disconnect(port);
                 }
-
+                port->connected = 0;
                 sock->state = SS_DISCONNECTING;
-
+                tipc_node_remove_conn(dnode, port->ref);
                 /* fall through */
 
         case SS_DISCONNECTING: