From b93d6471748de2ce02cc24774b774deb306a57a8 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Mon, 23 Nov 2009 15:53:56 -0500 Subject: sctp: implement the sender side for SACK-IMMEDIATELY extension This patch implement the sender side for SACK-IMMEDIATELY extension. Section 4.1. Sender Side Considerations Whenever the sender of a DATA chunk can benefit from the corresponding SACK chunk being sent back without delay, the sender MAY set the I-bit in the DATA chunk header. Reasons for setting the I-bit include o The sender is in the SHUTDOWN-PENDING state. o The application requests to set the I-bit of the last DATA chunk of a user message when providing the user message to the SCTP implementation. Signed-off-by: Wei Yongjun Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index c9f20e28521b..5732661c87d3 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -1011,6 +1011,13 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) break; case SCTP_XMIT_OK: + /* The sender is in the SHUTDOWN-PENDING state, + * The sender MAY set the I-bit in the DATA + * chunk header. + */ + if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) + chunk->chunk_hdr->flags |= SCTP_DATA_SACK_IMM; + break; default: -- cgit v1.2.3 From 46d5a808558181e03a4760d2188cc9879445738a Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Mon, 23 Nov 2009 15:54:00 -0500 Subject: sctp: Update max.burst implementation Current implementation of max.burst ends up limiting new data during cwnd decay period. The decay is happening becuase the connection is idle and we are allowed to fill the congestion window. The point of max.burst is to limit micro-bursts in response to large acks. This still happens, as max.burst is still applied to each transmit opportunity. It will also apply if a very large send is made (greater then allowed by burst). Tested-by: Florian Niederbacher Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 5732661c87d3..2f2377369e2b 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -931,6 +931,14 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) goto sctp_flush_out; } + /* Apply Max.Burst limitation to the current transport in + * case it will be used for new data. We are going to + * rest it before we return, but we want to apply the limit + * to the currently queued data. + */ + if (transport) + sctp_transport_burst_limited(transport); + /* Finally, transmit new packets. */ while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { /* RFC 2960 6.5 Every DATA chunk MUST carry a valid @@ -976,6 +984,10 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) packet = &transport->packet; sctp_packet_config(packet, vtag, asoc->peer.ecn_capable); + /* We've switched transports, so apply the + * Burst limit to the new transport. + */ + sctp_transport_burst_limited(transport); } SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", @@ -1070,6 +1082,9 @@ sctp_flush_out: packet = &t->packet; if (!sctp_packet_empty(packet)) error = sctp_packet_transmit(packet); + + /* Clear the burst limited state, if any */ + sctp_transport_burst_reset(t); } return error; -- cgit v1.2.3 From 5fdd4baef6195a1f2960e901c8877e2105f832ca Mon Sep 17 00:00:00 2001 From: Andrei Pelinescu-Onciul Date: Sun, 29 Nov 2009 00:14:02 -0800 Subject: sctp: on T3_RTX retransmit all the in-flight chunks When retransmitting due to T3 timeout, retransmit all the in-flight chunks for the corresponding transport/path, including chunks sent less then 1 rto ago. This is the correct behaviour according to rfc4960 section 6.3.3 E3 and "Note: Any DATA chunks that were sent to the address for which the T3-rtx timer expired but did not fit in one MTU (rule E3 above) should be marked for retransmission and sent as soon as cwnd allows (normally, when a SACK arrives). ". This fixes problems when more then one path is present and the T3 retransmission of the first chunk that timeouts stops the T3 timer for the initial active path, leaving all the other in-flight chunks waiting forever or until a new chunk is transmitted on the same path and timeouts (and this will happen only if the cwnd allows sending new chunks, but since cwnd was dropped to MTU by the timeout => it will wait until the first heartbeat). Example: 10 packets in flight, sent at 0.1 s intervals on the primary path. The primary path is down and the first packet timeouts. The first packet is retransmitted on another path, the T3 timer for the primary path is stopped and cwnd is set to MTU. All the other 9 in-flight packets will not be retransmitted (unless more new packets are sent on the primary path which depend on cwnd allowing it, and even in this case the 9 packets will be retransmitted only after a new packet timeouts which even in the best case would be more then RTO). This commit reverts d0ce92910bc04e107b2f3f2048f07e94f570035d and also removes the now unused transport->last_rto, introduced in b6157d8e03e1e780660a328f7183bcbfa4a93a19. p.s The problem is not only when multiple paths are there. It can happen in a single homed environment. If the application stops sending data, it possible to have a hung association. Signed-off-by: Andrei Pelinescu-Onciul Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/outqueue.c | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index c9f20e28521b..23e5e97aa617 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -423,16 +423,6 @@ void sctp_retransmit_mark(struct sctp_outq *q, if ((reason == SCTP_RTXR_FAST_RTX && (chunk->fast_retransmit == SCTP_NEED_FRTX)) || (reason != SCTP_RTXR_FAST_RTX && !chunk->tsn_gap_acked)) { - /* If this chunk was sent less then 1 rto ago, do not - * retransmit this chunk, but give the peer time - * to acknowlege it. Do this only when - * retransmitting due to T3 timeout. - */ - if (reason == SCTP_RTXR_T3_RTX && - time_before(jiffies, chunk->sent_at + - transport->last_rto)) - continue; - /* RFC 2960 6.2.1 Processing a Received SACK * * C) Any time a DATA chunk is marked for -- cgit v1.2.3 From f64f9e719261a87818dd192a3a2352e5b20fbd0f Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Sun, 29 Nov 2009 16:55:45 -0800 Subject: net: Move && and || to end of previous line Not including net/atm/ Compiled tested x86 allyesconfig only Added a > 80 column line or two, which I ignored. Existing checkpatch plaints willfully, cheerfully ignored. Signed-off-by: Joe Perches Signed-off-by: David S. Miller --- net/sctp/outqueue.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index e231a9831016..229690f02a1d 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -191,8 +191,8 @@ static inline int sctp_cacc_skip(struct sctp_transport *primary, __u32 tsn) { if (primary->cacc.changeover_active && - (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) - || sctp_cacc_skip_3_2(primary, tsn))) + (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) || + sctp_cacc_skip_3_2(primary, tsn))) return 1; return 0; } -- cgit v1.2.3