From cf9b4812e18aab6f86ff998bd7425a9e823269c3 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:10 -0400 Subject: sctp: fast recovery algorithm is per association. SCTP fast recovery algorithm really applies per association and impacts all transports. Signed-off-by: Vlad Yasevich --- include/net/sctp/structs.h | 12 ++++++------ net/sctp/transport.c | 32 +++++++++++++++++--------------- 2 files changed, 23 insertions(+), 21 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 9072dd67d8ad..d463296d9f79 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -895,9 +895,6 @@ struct sctp_transport { */ hb_sent:1, - /* Flag to track the current fast recovery state */ - fast_recovery:1, - /* Is the Path MTU update pending on this tranport */ pmtu_pending:1, @@ -952,9 +949,6 @@ struct sctp_transport { __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ - /* TSN marking the fast recovery exit point */ - __u32 fast_recovery_exit; - /* Destination */ struct dst_entry *dst; /* Source address. */ @@ -1723,6 +1717,12 @@ struct sctp_association { /* Highest TSN that is acknowledged by incoming SACKs. */ __u32 highest_sacked; + /* TSN marking the fast recovery exit point */ + __u32 fast_recovery_exit; + + /* Flag to track the current fast recovery state */ + __u8 fast_recovery; + /* The number of unacknowledged data chunks. Reported through * the SCTP_STATUS sockopt. */ diff --git a/net/sctp/transport.c b/net/sctp/transport.c index 854228bf3f34..fccf4947aff1 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -378,15 +378,16 @@ void sctp_transport_update_rto(struct sctp_transport *tp, __u32 rtt) void sctp_transport_raise_cwnd(struct sctp_transport *transport, __u32 sack_ctsn, __u32 bytes_acked) { + struct sctp_association *asoc = transport->asoc; __u32 cwnd, ssthresh, flight_size, pba, pmtu; cwnd = transport->cwnd; flight_size = transport->flight_size; /* See if we need to exit Fast Recovery first */ - if (transport->fast_recovery && - TSN_lte(transport->fast_recovery_exit, sack_ctsn)) - transport->fast_recovery = 0; + if (asoc->fast_recovery && + TSN_lte(asoc->fast_recovery_exit, sack_ctsn)) + asoc->fast_recovery = 0; /* The appropriate cwnd increase algorithm is performed if, and only * if the cumulative TSN whould advanced and the congestion window is @@ -415,7 +416,7 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, * 2) the destination's path MTU. This upper bound protects * against the ACK-Splitting attack outlined in [SAVAGE99]. */ - if (transport->fast_recovery) + if (asoc->fast_recovery) return; if (bytes_acked > pmtu) @@ -466,6 +467,8 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport, void sctp_transport_lower_cwnd(struct sctp_transport *transport, sctp_lower_cwnd_t reason) { + struct sctp_association *asoc = transport->asoc; + switch (reason) { case SCTP_LOWER_CWND_T3_RTX: /* RFC 2960 Section 7.2.3, sctpimpguide @@ -476,11 +479,11 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, * partial_bytes_acked = 0 */ transport->ssthresh = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); - transport->cwnd = transport->asoc->pathmtu; + 4*asoc->pathmtu); + transport->cwnd = asoc->pathmtu; - /* T3-rtx also clears fast recovery on the transport */ - transport->fast_recovery = 0; + /* T3-rtx also clears fast recovery */ + asoc->fast_recovery = 0; break; case SCTP_LOWER_CWND_FAST_RTX: @@ -496,15 +499,15 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, * cwnd = ssthresh * partial_bytes_acked = 0 */ - if (transport->fast_recovery) + if (asoc->fast_recovery) return; /* Mark Fast recovery */ - transport->fast_recovery = 1; - transport->fast_recovery_exit = transport->asoc->next_tsn - 1; + asoc->fast_recovery = 1; + asoc->fast_recovery_exit = asoc->next_tsn - 1; transport->ssthresh = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); + 4*asoc->pathmtu); transport->cwnd = transport->ssthresh; break; @@ -524,7 +527,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, if (time_after(jiffies, transport->last_time_ecne_reduced + transport->rtt)) { transport->ssthresh = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); + 4*asoc->pathmtu); transport->cwnd = transport->ssthresh; transport->last_time_ecne_reduced = jiffies; } @@ -540,7 +543,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport, * interval. */ transport->cwnd = max(transport->cwnd/2, - 4*transport->asoc->pathmtu); + 4*asoc->pathmtu); break; } @@ -625,7 +628,6 @@ void sctp_transport_reset(struct sctp_transport *t) t->error_count = 0; t->rto_pending = 0; t->hb_sent = 0; - t->fast_recovery = 0; /* Initialize the state information for SFR-CACC */ t->cacc.changeover_active = 0; -- cgit v1.2.3-59-g8ed1b