tipc: remove SS_DISCONNECTING state

In this commit, we replace the references to SS_DISCONNECTING with
the combination of sk_state TIPC_DISCONNECTING and flags set in
sk_shutdown.
We introduce a new function _tipc_shutdown(), which provides
the common code required by tipc_release() and tipc_shutdown().

Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 52 insertions, 80 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index a48c0c0676cf..e732b1fe7eab 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -442,6 +442,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
         }
         msg_set_origport(msg, tsk->portid);
         setup_timer(&sk->sk_timer, tipc_sk_timeout, (unsigned long)tsk);
+        sk->sk_shutdown = 0;
         sk->sk_backlog_rcv = tipc_backlog_rcv;
         sk->sk_rcvbuf = sysctl_tipc_rmem[1];
         sk->sk_data_ready = tipc_data_ready;
@@ -470,6 +471,44 @@ static void tipc_sk_callback(struct rcu_head *head)
         sock_put(&tsk->sk);
 }
 
+/* Caller should hold socket lock for the socket. */
+static void __tipc_shutdown(struct socket *sock, int error)
+{
+        struct sock *sk = sock->sk;
+        struct tipc_sock *tsk = tipc_sk(sk);
+        struct net *net = sock_net(sk);
+        u32 dnode = tsk_peer_node(tsk);
+        struct sk_buff *skb;
+
+        /* Reject all unreceived messages, except on an active connection
+         * (which disconnects locally & sends a 'FIN+' to peer).
+         */
+        while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+                if (TIPC_SKB_CB(skb)->bytes_read) {
+                        kfree_skb(skb);
+                } else {
+                        if (!tipc_sk_type_connectionless(sk) &&
+                            sk->sk_state != TIPC_DISCONNECTING) {
+                                tipc_set_sk_state(sk, TIPC_DISCONNECTING);
+                                tipc_node_remove_conn(net, dnode, tsk->portid);
+                        }
+                        tipc_sk_respond(sk, skb, error);
+                }
+        }
+        if (sk->sk_state != TIPC_DISCONNECTING) {
+                skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
+                                      TIPC_CONN_MSG, SHORT_H_SIZE, 0, dnode,
+                                      tsk_own_node(tsk), tsk_peer_port(tsk),
+                                      tsk->portid, error);
+                if (skb)
+                        tipc_node_xmit_skb(net, skb, dnode, tsk->portid);
+                if (!tipc_sk_type_connectionless(sk)) {
+                        tipc_node_remove_conn(net, dnode, tsk->portid);
+                        tipc_set_sk_state(sk, TIPC_DISCONNECTING);
+                }
+        }
+}
+
 /**
  * tipc_release - destroy a TIPC socket
  * @sock: socket to destroy
@@ -489,10 +528,7 @@ static void tipc_sk_callback(struct rcu_head *head)
 static int tipc_release(struct socket *sock)
 {
         struct sock *sk = sock->sk;
-        struct net *net;
         struct tipc_sock *tsk;
-        struct sk_buff *skb;
-        u32 dnode;
 
         /*
          * Exit if socket isn't fully initialized (occurs when a failed accept()
@@ -501,46 +537,16 @@ static int tipc_release(struct socket *sock)
         if (sk == NULL)
                 return 0;
 
-        net = sock_net(sk);
         tsk = tipc_sk(sk);
         lock_sock(sk);
 
-        /*
-         * Reject all unreceived messages, except on an active connection
-         * (which disconnects locally & sends a 'FIN+' to peer)
-         */
-        dnode = tsk_peer_node(tsk);
-        while (sock->state != SS_DISCONNECTING) {
-                skb = __skb_dequeue(&sk->sk_receive_queue);
-                if (skb == NULL)
-                        break;
-                if (TIPC_SKB_CB(skb)->bytes_read)
-                        kfree_skb(skb);
-                else {
-                        if ((sock->state == SS_CONNECTING) ||
-                            (sock->state == SS_CONNECTED)) {
-                                sock->state = SS_DISCONNECTING;
-                                tipc_node_remove_conn(net, dnode, tsk->portid);
-                        }
-                        tipc_sk_respond(sk, skb, TIPC_ERR_NO_PORT);
-                }
-        }
-
+        __tipc_shutdown(sock, TIPC_ERR_NO_PORT);
+        sk->sk_shutdown = SHUTDOWN_MASK;
         tipc_sk_withdraw(tsk, 0, NULL);
         sk_stop_timer(sk, &sk->sk_timer);
         tipc_sk_remove(tsk);
-        if (tipc_sk_connected(sk)) {
-                skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
-                                      TIPC_CONN_MSG, SHORT_H_SIZE, 0, dnode,
-                                      tsk_own_node(tsk), tsk_peer_port(tsk),
-                                      tsk->portid, TIPC_ERR_NO_PORT);
-                if (skb)
-                        tipc_node_xmit_skb(net, skb, dnode, tsk->portid);
-                tipc_node_remove_conn(net, dnode, tsk->portid);
-        }
 
         /* Reject any messages that accumulated in backlog queue */
-        sock->state = SS_DISCONNECTING;
         release_sock(sk);
 
         call_rcu(&tsk->rcu, tipc_sk_callback);
@@ -678,6 +684,11 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 
         sock_poll_wait(file, sk_sleep(sk), wait);
 
+        if (sk->sk_shutdown & RCV_SHUTDOWN)
+                mask |= POLLRDHUP | POLLIN | POLLRDNORM;
+        if (sk->sk_shutdown == SHUTDOWN_MASK)
+                mask |= POLLHUP;
+
         switch ((int)sock->state) {
         case SS_CONNECTED:
                 if (!tsk->link_cong && !tsk_conn_cong(tsk))
@@ -687,9 +698,6 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
                 if (!skb_queue_empty(&sk->sk_receive_queue))
                         mask |= (POLLIN | POLLRDNORM);
                 break;
-        case SS_DISCONNECTING:
-                mask = (POLLIN | POLLRDNORM | POLLHUP);
-                break;
         default:
                 switch (sk->sk_state) {
                 case TIPC_OPEN:
@@ -882,7 +890,7 @@ static int tipc_wait_for_sndmsg(struct socket *sock, long *timeo_p)
                 int err = sock_error(sk);
                 if (err)
                         return err;
-                if (sock->state == SS_DISCONNECTING)
+                if (sk->sk_shutdown & SEND_SHUTDOWN)
                         return -EPIPE;
                 if (!*timeo_p)
                         return -EAGAIN;
@@ -1335,7 +1343,7 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop)
         for (;;) {
                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
                 if (timeo && skb_queue_empty(&sk->sk_receive_queue)) {
-                        if (sock->state == SS_DISCONNECTING) {
+                        if (sk->sk_shutdown & RCV_SHUTDOWN) {
                                 err = -ENOTCONN;
                                 break;
                         }
@@ -1676,9 +1684,6 @@ static bool filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
                 /* 'ACK-' message is neither accepted nor rejected: */
                 msg_set_dest_droppable(hdr, 1);
                 return false;
-
-        case SS_DISCONNECTING:
-                break;
         }
 
         switch (sk->sk_state) {
@@ -2191,13 +2196,6 @@ exit:
 static int tipc_shutdown(struct socket *sock, int how)
 {
         struct sock *sk = sock->sk;
-        struct net *net = sock_net(sk);
-        struct tipc_sock *tsk = tipc_sk(sk);
-        struct sk_buff *skb;
-        u32 dnode = tsk_peer_node(tsk);
-        u32 dport = tsk_peer_port(tsk);
-        u32 onode = tipc_own_addr(net);
-        u32 oport = tsk->portid;
         int res;
 
         if (how != SHUT_RDWR)
@@ -2205,43 +2203,17 @@ static int tipc_shutdown(struct socket *sock, int how)
 
         lock_sock(sk);
 
-        if (sock->state == SS_CONNECTING || sock->state == SS_CONNECTED) {
-
-restart:
-                dnode = tsk_peer_node(tsk);
-
-                /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
-                skb = __skb_dequeue(&sk->sk_receive_queue);
-                if (skb) {
-                        if (TIPC_SKB_CB(skb)->bytes_read) {
-                                kfree_skb(skb);
-                                goto restart;
-                        }
-                        tipc_sk_respond(sk, skb, TIPC_CONN_SHUTDOWN);
-                } else {
-                        skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE,
-                                              TIPC_CONN_MSG, SHORT_H_SIZE,
-                                              0, dnode, onode, dport, oport,
-                                              TIPC_CONN_SHUTDOWN);
-                        if (skb)
-                                tipc_node_xmit_skb(net, skb, dnode, tsk->portid);
-                }
-                tipc_set_sk_state(sk, TIPC_DISCONNECTING);
-                tipc_node_remove_conn(net, dnode, tsk->portid);
-        }
-
-        switch (sk->sk_state) {
-        case TIPC_DISCONNECTING:
+        __tipc_shutdown(sock, TIPC_CONN_SHUTDOWN);
+        sk->sk_shutdown = SEND_SHUTDOWN;
 
+        if (sk->sk_state == TIPC_DISCONNECTING) {
                 /* Discard any unreceived messages */
                 __skb_queue_purge(&sk->sk_receive_queue);
 
                 /* Wake up anyone sleeping in poll */
                 sk->sk_state_change(sk);
                 res = 0;
-                break;
-
-        default:
+        } else {
                 res = -ENOTCONN;
         }