From e57edf6b6dba975eceede20b4b13699d4e88cd78 Mon Sep 17 00:00:00 2001 From: Erik Hugne Date: Thu, 4 Oct 2012 05:00:43 +0000 Subject: [PATCH] tipc: prevent dropped connections due to rcvbuf overflow When large buffers are sent over connected TIPC sockets, it is likely that the sk_backlog will be filled up on the receiver side, but the TIPC flow control mechanism is happily unaware of this since that is based on message count. The sender will receive a TIPC_ERR_OVERLOAD message when this occurs and drop it's side of the connection, leaving it stale on the receiver end. By increasing the sk_rcvbuf to a 'worst case' value, we avoid the overload caused by a full backlog queue and the flow control will work properly. This worst case value is the max TIPC message size times the flow control window, multiplied by two because a sender will transmit up to double the window size before a port is marked congested. We multiply this by 2 to account for the sk_buff and other overheads. Signed-off-by: Erik Hugne Signed-off-by: David S. Miller --- net/tipc/socket.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 09dc5b97e079..fd5f042dbff4 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -220,6 +220,7 @@ static int tipc_create(struct net *net, struct socket *sock, int protocol, sock_init_data(sock, sk); sk->sk_backlog_rcv = backlog_rcv; + sk->sk_rcvbuf = TIPC_FLOW_CONTROL_WIN * 2 * TIPC_MAX_USER_MSG_SIZE * 2; tipc_sk(sk)->p = tp_ptr; tipc_sk(sk)->conn_timeout = CONN_TIMEOUT_DEFAULT;