From bd69b981a354be40cc709f3046f0c56f00da6163 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Fri, 30 Apr 2010 21:42:43 -0400 Subject: sctp: assure at least one T3-rtx timer is running if a FORWARD TSN is sent PR-SCTP extension section 3.5 Sender Side Implementation of PR-SCTP: C5) If a FORWARD TSN is sent, the sender MUST assure that at least one T3-rtx timer is running. So this patch fix to assure at least one T3-rtx timer is running if a FORWARD TSN is or will to sent. Signed-off-by: Wei Yongjun Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index abfc0b8dee7..16d451a62b3 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -854,6 +854,12 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) if (status != SCTP_XMIT_OK) { /* put the chunk back */ list_add(&chunk->list, &q->control_chunk_list); + } else if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) { + /* PR-SCTP C5) If a FORWARD TSN is sent, the + * sender MUST assure that at least one T3-rtx + * timer is running. + */ + sctp_transport_reset_timers(transport, 0); } break; -- cgit v1.2.3-70-g09d2 From bc4f841a05364b2572bcc266e9fd7e9cf5f06d5b Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Fri, 30 Apr 2010 22:38:53 -0400 Subject: sctp: fix to retranmit at least one DATA chunk While doing retranmit, if control chunk exists, such as FORWARD TSN chunk, and the DATA chunk can not be bundled with this control chunk because of PMTU limit, no DATA chunk will be retranmitted in the current implementation. This patch makes sure to retranmit at least one DATA chunk in this case. Signed-off-by: Wei Yongjun Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 16d451a62b3..e333d583361 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -598,11 +598,23 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, if (fast_rtx && !chunk->fast_retransmit) continue; +redo: /* Attempt to append this chunk to the packet. */ status = sctp_packet_append_chunk(pkt, chunk); switch (status) { case SCTP_XMIT_PMTU_FULL: + if (!pkt->has_data && !pkt->has_cookie_echo) { + /* If this packet did not contain DATA then + * retransmission did not happen, so do it + * again. We'll ignore the error here since + * control chunks are already freed so there + * is nothing we can do. + */ + sctp_packet_transmit(pkt); + goto redo; + } + /* Send this packet. */ error = sctp_packet_transmit(pkt); -- cgit v1.2.3-70-g09d2 From ec7b9519509061bbc09a43284c3570aa492e07f0 Mon Sep 17 00:00:00 2001 From: Shan Wei Date: Fri, 30 Apr 2010 22:41:09 -0400 Subject: sctp: use sctp_chunk_is_data macro to decide a chunk is data chunk sctp_chunk_is_data macro is defined to decide that whether a chunk is data chunk or not. Signed-off-by: Shan Wei Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index e333d583361..a4fe7dee76e 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -308,7 +308,7 @@ int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) /* If it is data, queue it up, otherwise, send it * immediately. */ - if (SCTP_CID_DATA == chunk->chunk_hdr->type) { + if (sctp_chunk_is_data(chunk)) { /* Is it OK to queue data chunks? */ /* From 9. Termination of Association * -- cgit v1.2.3-70-g09d2 From ae19c54866450f6c6f79223ca7d37965859a54e1 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:09 -0400 Subject: sctp: remove 'resent' bit from the chunk The 'resent' bit is used to make sure that we don't update rto estimate based on retransmitted chunks. However, we already have the 'rto_pending' bit that we test when need to update rto, so 'resent' bit is just extra. Additionally, we currently have a bug in that we always set a 'resent' bit and thus rto estimate is only updated by Heartbeats. Signed-off-by: Vlad Yasevich --- include/net/sctp/structs.h | 3 +-- net/sctp/output.c | 25 +++++++++---------------- net/sctp/outqueue.c | 1 - net/sctp/sm_make_chunk.c | 1 - 4 files changed, 10 insertions(+), 20 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index ff301774471..03deffb1886 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -757,7 +757,6 @@ struct sctp_chunk { #define SCTP_NEED_FRTX 0x1 #define SCTP_DONT_FRTX 0x2 __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ - resent:1, /* Has this chunk ever been resent. */ has_tsn:1, /* Does this chunk have a TSN yet? */ has_ssn:1, /* Does this chunk have a SSN yet? */ singleton:1, /* Only chunk in the packet? */ @@ -1065,7 +1064,7 @@ void sctp_transport_route(struct sctp_transport *, union sctp_addr *, struct sctp_sock *); void sctp_transport_pmtu(struct sctp_transport *); void sctp_transport_free(struct sctp_transport *); -void sctp_transport_reset_timers(struct sctp_transport *, int); +void sctp_transport_reset_timers(struct sctp_transport *); void sctp_transport_hold(struct sctp_transport *); void sctp_transport_put(struct sctp_transport *); void sctp_transport_update_rto(struct sctp_transport *, __u32); diff --git a/net/sctp/output.c b/net/sctp/output.c index fad261d41ec..35e49b9df4e 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -429,24 +429,17 @@ int sctp_packet_transmit(struct sctp_packet *packet) list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) { list_del_init(&chunk->list); if (sctp_chunk_is_data(chunk)) { + /* 6.3.1 C4) When data is in flight and when allowed + * by rule C5, a new RTT measurement MUST be made each + * round trip. Furthermore, new RTT measurements + * SHOULD be made no more than once per round-trip + * for a given destination transport address. + */ - if (!chunk->resent) { - - /* 6.3.1 C4) When data is in flight and when allowed - * by rule C5, a new RTT measurement MUST be made each - * round trip. Furthermore, new RTT measurements - * SHOULD be made no more than once per round-trip - * for a given destination transport address. - */ - - if (!tp->rto_pending) { - chunk->rtt_in_progress = 1; - tp->rto_pending = 1; - } + if (!tp->rto_pending) { + chunk->rtt_in_progress = 1; + tp->rto_pending = 1; } - - chunk->resent = 1; - has_data = 1; } diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index a4fe7dee76e..4e551ba8998 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -1405,7 +1405,6 @@ static void sctp_check_transmitted(struct sctp_outq *q, * instance). */ if (!tchunk->tsn_gap_acked && - !tchunk->resent && tchunk->rtt_in_progress) { tchunk->rtt_in_progress = 0; rtt = jiffies - tchunk->sent_at; diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 33aed1c6cbd..24effdf471e 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -1205,7 +1205,6 @@ struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, INIT_LIST_HEAD(&retval->list); retval->skb = skb; retval->asoc = (struct sctp_association *)asoc; - retval->resent = 0; retval->has_tsn = 0; retval->has_ssn = 0; retval->rtt_in_progress = 0; -- cgit v1.2.3-70-g09d2 From d9efc2231b28bc199f9de4dd594248b7341188e5 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:09 -0400 Subject: sctp: Do not force T3 timer on fast retransmissions. We don't need to force the T3 timer any more and it's actually wrong to do as it causes too long of a delay. The timer will be started if one is not running, but if one is running, we leave it alone. Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 15 +++------------ net/sctp/transport.c | 4 ++-- 2 files changed, 5 insertions(+), 14 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 4e551ba8998..786c4ff97ae 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -659,14 +659,6 @@ redo: if (chunk->fast_retransmit == SCTP_NEED_FRTX) chunk->fast_retransmit = SCTP_DONT_FRTX; - /* Force start T3-rtx timer when fast retransmitting - * the earliest outstanding TSN - */ - if (!timer && fast_rtx && - ntohl(chunk->subh.data_hdr->tsn) == - asoc->ctsn_ack_point + 1) - timer = 2; - q->empty = 0; break; } @@ -871,7 +863,7 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) * sender MUST assure that at least one T3-rtx * timer is running. */ - sctp_transport_reset_timers(transport, 0); + sctp_transport_reset_timers(transport); } break; @@ -924,8 +916,7 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) rtx_timeout, &start_timer); if (start_timer) - sctp_transport_reset_timers(transport, - start_timer-1); + sctp_transport_reset_timers(transport); /* This can happen on COOKIE-ECHO resend. Only * one chunk can get bundled with a COOKIE-ECHO. @@ -1058,7 +1049,7 @@ static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) list_add_tail(&chunk->transmitted_list, &transport->transmitted); - sctp_transport_reset_timers(transport, 0); + sctp_transport_reset_timers(transport); q->empty = 0; diff --git a/net/sctp/transport.c b/net/sctp/transport.c index be4d63d5a5c..0ebb97fc98e 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -195,7 +195,7 @@ static void sctp_transport_destroy(struct sctp_transport *transport) /* Start T3_rtx timer if it is not already running and update the heartbeat * timer. This routine is called every time a DATA chunk is sent. */ -void sctp_transport_reset_timers(struct sctp_transport *transport, int force) +void sctp_transport_reset_timers(struct sctp_transport *transport) { /* RFC 2960 6.3.2 Retransmission Timer Rules * @@ -205,7 +205,7 @@ void sctp_transport_reset_timers(struct sctp_transport *transport, int force) * address. */ - if (force || !timer_pending(&transport->T3_rtx_timer)) + if (!timer_pending(&transport->T3_rtx_timer)) if (!mod_timer(&transport->T3_rtx_timer, jiffies + transport->rto)) sctp_transport_hold(transport); -- cgit v1.2.3-70-g09d2 From ea862c8d1f4a0d193979c7412c3b946f600721ce Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:10 -0400 Subject: sctp: correctly mark missing chunks in fast recovery According to RFC 4960 Section 7.2.4: If an endpoint is in Fast Recovery and a SACK arrives that advances the Cumulative TSN Ack Point, the miss indications are incremented for all TSNs reported missing in the SACK. Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 786c4ff97ae..b491a1aac3e 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -1154,6 +1154,7 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) struct sctp_transport *primary = asoc->peer.primary_path; int count_of_newacks = 0; int gap_ack_blocks; + u8 accum_moved = 0; /* Grab the association's destination address list. */ transport_list = &asoc->peer.transport_addr_list; @@ -1232,16 +1233,22 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) count_of_newacks ++; } + /* Move the Cumulative TSN Ack Point if appropriate. */ + if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) { + asoc->ctsn_ack_point = sack_ctsn; + accum_moved = 1; + } + if (gap_ack_blocks) { + + if (asoc->fast_recovery && accum_moved) + highest_new_tsn = highest_tsn; + list_for_each_entry(transport, transport_list, transports) sctp_mark_missing(q, &transport->transmitted, transport, highest_new_tsn, count_of_newacks); } - /* Move the Cumulative TSN Ack Point if appropriate. */ - if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) - asoc->ctsn_ack_point = sack_ctsn; - /* Update unack_data field in the assoc. */ sctp_sack_update_unack_data(asoc, sack); @@ -1685,7 +1692,8 @@ static void sctp_mark_missing(struct sctp_outq *q, struct sctp_chunk *chunk; __u32 tsn; char do_fast_retransmit = 0; - struct sctp_transport *primary = q->asoc->peer.primary_path; + struct sctp_association *asoc = q->asoc; + struct sctp_transport *primary = asoc->peer.primary_path; list_for_each_entry(chunk, transmitted_queue, transmitted_list) { -- cgit v1.2.3-70-g09d2 From bfa0d9843ac5feb9667990706b4524390fee4df9 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 30 Apr 2010 22:41:10 -0400 Subject: sctp: Optimize computation of highest new tsn in SACK. Right now, if the highest tsn in the SACK doesn't change, we'll end up scanning the transmitted lists on the transports twice: once for locating the highest _new_ tsn, and once for actually tagging chunks as acked. This is a waste, since we can record the highest _new_ tsn at the same time as tagging chunks. Long ago this was not possible because we would try to mark chunks as missing at the same time as tagging them acked and this approach didn't work. Now that the two steps are separate, we can re-use the old approach. Signed-off-by: Vlad Yasevich --- net/sctp/outqueue.c | 42 +++++++----------------------------------- 1 file changed, 7 insertions(+), 35 deletions(-) (limited to 'net/sctp/outqueue.c') diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index b491a1aac3e..5d057178ce0 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -62,7 +62,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, struct list_head *transmitted_queue, struct sctp_transport *transport, struct sctp_sackhdr *sack, - __u32 highest_new_tsn); + __u32 *highest_new_tsn); static void sctp_mark_missing(struct sctp_outq *q, struct list_head *transmitted_queue, @@ -1109,32 +1109,6 @@ static void sctp_sack_update_unack_data(struct sctp_association *assoc, assoc->unack_data = unack_data; } -/* Return the highest new tsn that is acknowledged by the given SACK chunk. */ -static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack, - struct sctp_association *asoc) -{ - struct sctp_transport *transport; - struct sctp_chunk *chunk; - __u32 highest_new_tsn, tsn; - struct list_head *transport_list = &asoc->peer.transport_addr_list; - - highest_new_tsn = ntohl(sack->cum_tsn_ack); - - list_for_each_entry(transport, transport_list, transports) { - list_for_each_entry(chunk, &transport->transmitted, - transmitted_list) { - tsn = ntohl(chunk->subh.data_hdr->tsn); - - if (!chunk->tsn_gap_acked && - TSN_lt(highest_new_tsn, tsn) && - sctp_acked(sack, tsn)) - highest_new_tsn = tsn; - } - } - - return highest_new_tsn; -} - /* This is where we REALLY process a SACK. * * Process the SACK against the outqueue. Mostly, this just frees @@ -1203,18 +1177,15 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) if (gap_ack_blocks) highest_tsn += ntohs(frags[gap_ack_blocks - 1].gab.end); - if (TSN_lt(asoc->highest_sacked, highest_tsn)) { - highest_new_tsn = highest_tsn; + if (TSN_lt(asoc->highest_sacked, highest_tsn)) asoc->highest_sacked = highest_tsn; - } else { - highest_new_tsn = sctp_highest_new_tsn(sack, asoc); - } + highest_new_tsn = sack_ctsn; /* Run through the retransmit queue. Credit bytes received * and free those chunks that we can. */ - sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn); + sctp_check_transmitted(q, &q->retransmit, NULL, sack, &highest_new_tsn); /* Run through the transmitted queue. * Credit bytes received and free those chunks which we can. @@ -1223,7 +1194,7 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) */ list_for_each_entry(transport, transport_list, transports) { sctp_check_transmitted(q, &transport->transmitted, - transport, sack, highest_new_tsn); + transport, sack, &highest_new_tsn); /* * SFR-CACC algorithm: * C) Let count_of_newacks be the number of @@ -1331,7 +1302,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, struct list_head *transmitted_queue, struct sctp_transport *transport, struct sctp_sackhdr *sack, - __u32 highest_new_tsn_in_sack) + __u32 *highest_new_tsn_in_sack) { struct list_head *lchunk; struct sctp_chunk *tchunk; @@ -1419,6 +1390,7 @@ static void sctp_check_transmitted(struct sctp_outq *q, */ if (!tchunk->tsn_gap_acked) { tchunk->tsn_gap_acked = 1; + *highest_new_tsn_in_sack = tsn; bytes_acked += sctp_data_size(tchunk); if (!tchunk->transport) migrate_bytes += sctp_data_size(tchunk); -- cgit v1.2.3-70-g09d2