diff options
Diffstat (limited to 'net/sctp/outqueue.c')
| -rw-r--r-- | net/sctp/outqueue.c | 158 |
1 files changed, 104 insertions, 54 deletions
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c index 59edfd25a19..4328ad5439c 100644 --- a/net/sctp/outqueue.c +++ b/net/sctp/outqueue.c @@ -71,6 +71,8 @@ static void sctp_mark_missing(struct sctp_outq *q, static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); +static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout); + /* Add data to the front of the queue. */ static inline void sctp_outq_head_data(struct sctp_outq *q, struct sctp_chunk *ch) @@ -208,6 +210,7 @@ void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) INIT_LIST_HEAD(&q->sacked); INIT_LIST_HEAD(&q->abandoned); + q->fast_rtx = 0; q->outstanding_bytes = 0; q->empty = 1; q->cork = 0; @@ -500,6 +503,7 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, case SCTP_RTXR_FAST_RTX: SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS); sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); + q->fast_rtx = 1; break; case SCTP_RTXR_PMTUD: SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS); @@ -518,9 +522,15 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by * following the procedures outlined in C1 - C5. */ - sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); + if (reason == SCTP_RTXR_T3_RTX) + sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); - error = sctp_outq_flush(q, /* rtx_timeout */ 1); + /* Flush the queues only on timeout, since fast_rtx is only + * triggered during sack processing and the queue + * will be flushed at the end. + */ + if (reason != SCTP_RTXR_FAST_RTX) + error = sctp_outq_flush(q, /* rtx_timeout */ 1); if (error) q->asoc->base.sk->sk_err = -error; @@ -538,17 +548,23 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, int rtx_timeout, int *start_timer) { struct list_head *lqueue; - struct list_head *lchunk; struct sctp_transport *transport = pkt->transport; sctp_xmit_t status; struct sctp_chunk *chunk, *chunk1; struct sctp_association *asoc; + int fast_rtx; int error = 0; + int timer = 0; + int done = 0; asoc = q->asoc; lqueue = &q->retransmit; + fast_rtx = q->fast_rtx; - /* RFC 2960 6.3.3 Handle T3-rtx Expiration + /* This loop handles time-out retransmissions, fast retransmissions, + * and retransmissions due to opening of whindow. + * + * RFC 2960 6.3.3 Handle T3-rtx Expiration * * E3) Determine how many of the earliest (i.e., lowest TSN) * outstanding DATA chunks for the address for which the @@ -563,12 +579,12 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, * [Just to be painfully clear, if we are retransmitting * because a timeout just happened, we should send only ONE * packet of retransmitted data.] + * + * For fast retransmissions we also send only ONE packet. However, + * if we are just flushing the queue due to open window, we'll + * try to send as much as possible. */ - lchunk = sctp_list_dequeue(lqueue); - - while (lchunk) { - chunk = list_entry(lchunk, struct sctp_chunk, - transmitted_list); + list_for_each_entry_safe(chunk, chunk1, lqueue, transmitted_list) { /* Make sure that Gap Acked TSNs are not retransmitted. A * simple approach is just to move such TSNs out of the @@ -576,58 +592,60 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, * next chunk. */ if (chunk->tsn_gap_acked) { - list_add_tail(lchunk, &transport->transmitted); - lchunk = sctp_list_dequeue(lqueue); + list_del(&chunk->transmitted_list); + list_add_tail(&chunk->transmitted_list, + &transport->transmitted); continue; } + /* If we are doing fast retransmit, ignore non-fast_rtransmit + * chunks + */ + if (fast_rtx && !chunk->fast_retransmit) + continue; + /* Attempt to append this chunk to the packet. */ status = sctp_packet_append_chunk(pkt, chunk); switch (status) { case SCTP_XMIT_PMTU_FULL: /* Send this packet. */ - if ((error = sctp_packet_transmit(pkt)) == 0) - *start_timer = 1; + error = sctp_packet_transmit(pkt); /* If we are retransmitting, we should only * send a single packet. */ - if (rtx_timeout) { - list_add(lchunk, lqueue); - lchunk = NULL; - } + if (rtx_timeout || fast_rtx) + done = 1; - /* Bundle lchunk in the next round. */ + /* Bundle next chunk in the next round. */ break; case SCTP_XMIT_RWND_FULL: /* Send this packet. */ - if ((error = sctp_packet_transmit(pkt)) == 0) - *start_timer = 1; + error = sctp_packet_transmit(pkt); /* Stop sending DATA as there is no more room * at the receiver. */ - list_add(lchunk, lqueue); - lchunk = NULL; + done = 1; break; case SCTP_XMIT_NAGLE_DELAY: /* Send this packet. */ - if ((error = sctp_packet_transmit(pkt)) == 0) - *start_timer = 1; + error = sctp_packet_transmit(pkt); /* Stop sending DATA because of nagle delay. */ - list_add(lchunk, lqueue); - lchunk = NULL; + done = 1; break; default: /* The append was successful, so add this chunk to * the transmitted list. */ - list_add_tail(lchunk, &transport->transmitted); + list_del(&chunk->transmitted_list); + list_add_tail(&chunk->transmitted_list, + &transport->transmitted); /* Mark the chunk as ineligible for fast retransmit * after it is retransmitted. @@ -635,27 +653,44 @@ static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, if (chunk->fast_retransmit > 0) chunk->fast_retransmit = -1; - *start_timer = 1; - q->empty = 0; + /* 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; - /* Retrieve a new chunk to bundle. */ - lchunk = sctp_list_dequeue(lqueue); + q->empty = 0; break; } - /* If we are here due to a retransmit timeout or a fast - * retransmit and if there are any chunks left in the retransmit - * queue that could not fit in the PMTU sized packet, they need - * to be marked as ineligible for a subsequent fast retransmit. - */ - if (rtx_timeout && !lchunk) { - list_for_each_entry(chunk1, lqueue, transmitted_list) { - if (chunk1->fast_retransmit > 0) - chunk1->fast_retransmit = -1; - } + /* Set the timer if there were no errors */ + if (!error && !timer) + timer = 1; + + if (done) + break; + } + + /* If we are here due to a retransmit timeout or a fast + * retransmit and if there are any chunks left in the retransmit + * queue that could not fit in the PMTU sized packet, they need + * to be marked as ineligible for a subsequent fast retransmit. + */ + if (rtx_timeout || fast_rtx) { + list_for_each_entry(chunk1, lqueue, transmitted_list) { + if (chunk1->fast_retransmit > 0) + chunk1->fast_retransmit = -1; } } + *start_timer = timer; + + /* Clear fast retransmit hint */ + if (fast_rtx) + q->fast_rtx = 0; + return error; } @@ -669,6 +704,7 @@ int sctp_outq_uncork(struct sctp_outq *q) return error; } + /* * Try to flush an outqueue. * @@ -678,7 +714,7 @@ int sctp_outq_uncork(struct sctp_outq *q) * locking concerns must be made. Today we use the sock lock to protect * this function. */ -int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) +static int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) { struct sctp_packet *packet; struct sctp_packet singleton; @@ -692,6 +728,7 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) sctp_xmit_t status; int error = 0; int start_timer = 0; + int one_packet = 0; /* These transports have chunks to send. */ struct list_head transport_list; @@ -797,20 +834,33 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) if (sctp_test_T_bit(chunk)) { packet->vtag = asoc->c.my_vtag; } - case SCTP_CID_SACK: - case SCTP_CID_HEARTBEAT: + /* The following chunks are "response" chunks, i.e. + * they are generated in response to something we + * received. If we are sending these, then we can + * send only 1 packet containing these chunks. + */ case SCTP_CID_HEARTBEAT_ACK: - case SCTP_CID_SHUTDOWN: case SCTP_CID_SHUTDOWN_ACK: - case SCTP_CID_ERROR: - case SCTP_CID_COOKIE_ECHO: case SCTP_CID_COOKIE_ACK: - case SCTP_CID_ECN_ECNE: + case SCTP_CID_COOKIE_ECHO: + case SCTP_CID_ERROR: case SCTP_CID_ECN_CWR: - case SCTP_CID_ASCONF: case SCTP_CID_ASCONF_ACK: + one_packet = 1; + /* Fall throught */ + + case SCTP_CID_SACK: + case SCTP_CID_HEARTBEAT: + case SCTP_CID_SHUTDOWN: + case SCTP_CID_ECN_ECNE: + case SCTP_CID_ASCONF: case SCTP_CID_FWD_TSN: - sctp_packet_transmit_chunk(packet, chunk); + status = sctp_packet_transmit_chunk(packet, chunk, + one_packet); + if (status != SCTP_XMIT_OK) { + /* put the chunk back */ + list_add(&chunk->list, &q->control_chunk_list); + } break; default: @@ -862,7 +912,8 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) rtx_timeout, &start_timer); if (start_timer) - sctp_transport_reset_timers(transport); + sctp_transport_reset_timers(transport, + start_timer-1); /* This can happen on COOKIE-ECHO resend. Only * one chunk can get bundled with a COOKIE-ECHO. @@ -940,7 +991,7 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) atomic_read(&chunk->skb->users) : -1); /* Add the chunk to the packet. */ - status = sctp_packet_transmit_chunk(packet, chunk); + status = sctp_packet_transmit_chunk(packet, chunk, 0); switch (status) { case SCTP_XMIT_PMTU_FULL: @@ -977,7 +1028,7 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) list_add_tail(&chunk->transmitted_list, &transport->transmitted); - sctp_transport_reset_timers(transport); + sctp_transport_reset_timers(transport, start_timer-1); q->empty = 0; @@ -1205,7 +1256,6 @@ int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) * Make sure the empty queue handler will get run later. */ q->empty = (list_empty(&q->out_chunk_list) && - list_empty(&q->control_chunk_list) && list_empty(&q->retransmit)); if (!q->empty) goto finish; |