From 8c2f414ad1b3aa3af05791cd7312eb8ff9d80e0d Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Tue, 9 Jul 2013 16:17:04 +0200 Subject: [PATCH] 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: Vlad Yasevich Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller --- net/sctp/outqueue.c | 9 +++++++++ net/sctp/sm_sideeffect.c | 6 ++++++ 2 files changed, 15 insertions(+) diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index cb80a8e..ef9e2bb 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -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); diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index cf6f845..9da6885 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -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. -- 2.7.4