Commit c948bb5c authored May 18, 2016 by Sowmini Varadhan Committed by David S. Miller May 20, 2016

RDS: TCP: Avoid rds connection churn from rogue SYNs



When a rogue SYN is received after the connection arbitration
algorithm has converged, the incoming SYN should not needlessly
quiesce the transmit path, and it should not result in needless
TCP connection resets due to re-execution of the connection
arbitration logic.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 37e14f4f

net/rds/tcp_listen.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -132,11 +132,13 @@ int rds_tcp_accept_one(struct socket *sock)
		* so we must quiesce any send threads before resetting
		* c_transport_data.
		*/
		if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr) \|\|
		!conn->c_outgoing) {
		goto rst_nsk;
		} else {
		atomic_set(&conn->c_state, RDS_CONN_CONNECTING);
		wait_event(conn->c_waitq,
		!test_bit(RDS_IN_XMIT, &conn->c_flags));
		if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr)) {
		goto rst_nsk;
		} else if (rs_tcp->t_sock) {
		rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp);
		conn->c_outgoing = 0;
		}