1 files changed, 77 insertions, 43 deletions

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 59edfd25a19c..ace6770e9048 100644
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -208,6 +208,7 @@ 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 +501,7 @@ 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 +520,15 @@ 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 +546,23 @@ 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 +577,12 @@ 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 +590,60 @@ 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 +651,44 @@ 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;
 }
 
@@ -862,7 +895,8 @@ 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.
@@ -977,7 +1011,7 @@ 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;