tipc: standardize sendmsg routine of connected socket

Standardize the behaviour of waiting for events in TIPC send_packet()
so that all variables of socket or port structures are protected within
socket lock, allowing the process of calling sendmsg() to be woken up
at appropriate time.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 41 insertions, 19 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 3e019737e4b3..c4803101fbdf 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -695,6 +695,34 @@ exit:
         return res;
 }
 
+static int tipc_wait_for_sndpkt(struct socket *sock, long *timeo_p)
+{
+        struct sock *sk = sock->sk;
+        struct tipc_port *tport = tipc_sk_port(sk);
+        DEFINE_WAIT(wait);
+        int done;
+
+        do {
+                int err = sock_error(sk);
+                if (err)
+                        return err;
+                if (sock->state == SS_DISCONNECTING)
+                        return -EPIPE;
+                else if (sock->state != SS_CONNECTED)
+                        return -ENOTCONN;
+                if (!*timeo_p)
+                        return -EAGAIN;
+                if (signal_pending(current))
+                        return sock_intr_errno(*timeo_p);
+
+                prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+                done = sk_wait_event(sk, timeo_p,
+                                     (!tport->congested || !tport->connected));
+                finish_wait(sk_sleep(sk), &wait);
+        } while (!done);
+        return 0;
+}
+
 /**
  * send_packet - send a connection-oriented message
  * @iocb: if NULL, indicates that socket lock is already held
@@ -712,8 +740,8 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
         struct sock *sk = sock->sk;
         struct tipc_port *tport = tipc_sk_port(sk);
         struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
-        long timeout_val;
-        int res;
+        int res = -EINVAL;
+        long timeo;
 
         /* Handle implied connection establishment */
         if (unlikely(dest))
@@ -725,30 +753,24 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
         if (iocb)
                 lock_sock(sk);
 
-        timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
+        if (unlikely(sock->state != SS_CONNECTED)) {
+                if (sock->state == SS_DISCONNECTING)
+                        res = -EPIPE;
+                else
+                        res = -ENOTCONN;
+                goto exit;
+        }
 
+        timeo = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
         do {
-                if (unlikely(sock->state != SS_CONNECTED)) {
-                        if (sock->state == SS_DISCONNECTING)
-                                res = -EPIPE;
-                        else
-                                res = -ENOTCONN;
-                        break;
-                }
-
                 res = tipc_send(tport->ref, m->msg_iov, total_len);
                 if (likely(res != -ELINKCONG))
                         break;
-                if (timeout_val <= 0L) {
-                        res = timeout_val ? timeout_val : -EWOULDBLOCK;
+                res = tipc_wait_for_sndpkt(sock, &timeo);
+                if (res)
                         break;
-                }
-                release_sock(sk);
-                timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk),
-                        (!tport->congested || !tport->connected), timeout_val);
-                lock_sock(sk);
         } while (1);
-
+exit:
         if (iocb)
                 release_sock(sk);
         return res;