[tipc-discussion] [net v1 3/3] tipc: fix connection failure under link congestion

[Tung N. <tun...@de...>]

When initiating a connection message under link congestion,
function __tipc_sendmsg() is used to send the connection message to
a listening socket. Function tipc_wait_for_cond() is called to wait
until the link is not congested. However, it calls tipc_sk_sock_err()
for sanity check and this function returns -ENOTCONN immediately
because the socket state is not ESTABLISHED.

This commit fixes this issue by moving the sanity check for
connection-oriented socket from tipc_sk_sock_err() to
__tipc_sendstream().

Fixes: 8c44e1af16b2 ("tipc: unify tipc_wait_for_sndpkt() and tipc_wait_for_sndmsg() functions)
Signed-off-by: Tung Nguyen <tun...@de...>
---
 net/tipc/socket.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 9fd9a5727786..0ce441fd126c 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -363,12 +363,9 @@ static int tipc_sk_sock_err(struct socket *sock, long *timeout)
 
 	if (err)
 		return err;
-	if (typ == SOCK_STREAM || typ == SOCK_SEQPACKET) {
-		if (sk->sk_state == TIPC_DISCONNECTING)
-			return -EPIPE;
-		else if (!tipc_sk_connected(sk))
-			return -ENOTCONN;
-	}
+	if ((typ == SOCK_STREAM || typ == SOCK_SEQPACKET) &&
+	    (sk->sk_state == TIPC_DISCONNECTING))
+		return -EPIPE;
 	if (!*timeout)
 		return -EAGAIN;
 	if (signal_pending(current))
@@ -1462,6 +1459,13 @@ static int __tipc_sendstream(struct socket *sock, struct msghdr *m, size_t dlen)
 		return rc;
 	}
 
+	if (!tipc_sk_connected(sk)) {
+		if (sk->sk_state == TIPC_DISCONNECTING)
+			return -EPIPE;
+		else
+			return -ENOTCONN;
+	}
+
 	do {
 		rc = tipc_wait_for_cond(sock, &timeout,
 					(!tsk->cong_link_cnt &&
-- 
2.17.1