Commit 8c2f414a authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

net: sctp: confirm route during forward progress 



This fix has been proposed originally by Vlad Yasevich. He says:

  When SCTP makes forward progress (receives a SACK that acks new chunks,
  renegs, or answeres 0-window probes) or when HB-ACK arrives, mark
  the route as confirmed so we don't unnecessarily send NUD probes.

Having a simple SCTP client/server that exchange data chunks every 1sec,
without this patch ARP requests are sent periodically every 40-60sec.
With this fix applied, an ARP request is only done once right at the
"session" beginning. Also, when clearing the related ARP cache entry
manually during the session, a new request is correctly done. I have
only "backported" this to net-next and tested that it works, so full
credit goes to Vlad.

Signed-off-by: default avatarVlad Yasevich <vyasevich@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e1d6fbc3

net/sctp/outqueue.c

+9 −0
Original line number Diff line number Diff line
@@ -1334,6 +1334,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, 
	__u8 restart_timer = 0;

	int bytes_acked = 0;

	int migrate_bytes = 0;

	bool forward_progress = false;



	sack_ctsn = ntohl(sack->cum_tsn_ack);
@@ -1400,6 +1401,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, 
				bytes_acked += sctp_data_size(tchunk);

				if (!tchunk->transport)

					migrate_bytes += sctp_data_size(tchunk);

				forward_progress = true;

			}



			if (TSN_lte(tsn, sack_ctsn)) {
@@ -1413,6 +1415,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, 
				 * current RTO.

				 */

				restart_timer = 1;

				forward_progress = true;



				if (!tchunk->tsn_gap_acked) {

					/*
@@ -1503,6 +1506,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, 
			 */

			transport->error_count = 0;

			transport->asoc->overall_error_count = 0;

			forward_progress = true;



			/*

			 * While in SHUTDOWN PENDING, we may have started
@@ -1576,6 +1580,11 @@ static void sctp_check_transmitted(struct sctp_outq *q, 
				       jiffies + transport->rto))

				sctp_transport_hold(transport);

		}



		if (forward_progress) {

			if (transport->dst)

				dst_confirm(transport->dst);

		}

	}



	list_splice(&tlist, transmitted_queue);

net/sctp/sm_sideeffect.c

+6 −0
Original line number Diff line number Diff line
@@ -730,6 +730,12 @@ static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds, 
		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,

					     SCTP_HEARTBEAT_SUCCESS);



	/* HB-ACK was received for a the proper HB.  Consider this

	 * forward progress.

	 */

	if (t->dst)

		dst_confirm(t->dst);



	/* The receiver of the HEARTBEAT ACK should also perform an

	 * RTT measurement for that destination transport address

	 * using the time value carried in the HEARTBEAT ACK chunk.

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