From 27852c26baab8b95fc9a2b3e8a18770ecd553f10 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Thu, 2 Feb 2006 16:57:31 -0800 Subject: [PATCH] [SCTP]: Fix 'fast retransmit' to send a TSN only once. SCTP used to "fast retransmit" a TSN every time we hit the number of missing reports for the TSN. However the Implementers Guide specifies that we should only "fast retransmit" a given TSN once. Subsequent retransmits should be timeouts only. Also change the number of missing reports to 3 as per the latest IG(similar to TCP). Signed-off-by: Vlad Yasevich Signed-off-by: Sridhar Samudrala Signed-off-by: David S. Miller --- include/net/sctp/structs.h | 2 +- net/sctp/output.c | 2 +- net/sctp/outqueue.c | 12 +++++++----- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 8c522ae031..072f407848 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -700,7 +700,7 @@ struct sctp_chunk { __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ __u8 pdiscard; /* Discard the whole packet now? */ __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ - __u8 fast_retransmit; /* Is this chunk fast retransmitted? */ + __s8 fast_retransmit; /* Is this chunk fast retransmitted? */ __u8 tsn_missing_report; /* Data chunk missing counter. */ }; diff --git a/net/sctp/output.c b/net/sctp/output.c index a40991ef72..437cba7260 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -608,7 +608,7 @@ static sctp_xmit_t sctp_packet_append_data(struct sctp_packet *packet, * When a Fast Retransmit is being performed the sender SHOULD * ignore the value of cwnd and SHOULD NOT delay retransmission. */ - if (!chunk->fast_retransmit) + if (chunk->fast_retransmit <= 0) if (transport->flight_size >= transport->cwnd) { retval = SCTP_XMIT_RWND_FULL; goto finish; diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index efb72faba2..f148f9576d 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -406,7 +406,7 @@ void sctp_retransmit_mark(struct sctp_outq *q, * chunks that are not yet acked should be added to the * retransmit queue. */ - if ((fast_retransmit && chunk->fast_retransmit) || + if ((fast_retransmit && (chunk->fast_retransmit > 0)) || (!fast_retransmit && !chunk->tsn_gap_acked)) { /* RFC 2960 6.2.1 Processing a Received SACK * @@ -603,7 +603,8 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, /* Mark the chunk as ineligible for fast retransmit * after it is retransmitted. */ - chunk->fast_retransmit = 0; + if (chunk->fast_retransmit > 0) + chunk->fast_retransmit = -1; *start_timer = 1; q->empty = 0; @@ -621,7 +622,8 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, list_for_each(lchunk1, lqueue) { chunk1 = list_entry(lchunk1, struct sctp_chunk, transmitted_list); - chunk1->fast_retransmit = 0; + if (chunk1->fast_retransmit > 0) + chunk1->fast_retransmit = -1; } } } @@ -1562,11 +1564,11 @@ static void sctp_mark_missing(struct sctp_outq *q, /* * M4) If any DATA chunk is found to have a * 'TSN.Missing.Report' - * value larger than or equal to 4, mark that chunk for + * value larger than or equal to 3, mark that chunk for * retransmission and start the fast retransmit procedure. */ - if (chunk->tsn_missing_report >= 4) { + if (chunk->tsn_missing_report >= 3) { chunk->fast_retransmit = 1; do_fast_retransmit = 1; } -- 2.39.5