1 files changed, 31 insertions, 13 deletions

diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index 23a9f1a95b7d..9732c797e8ed 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -190,20 +190,28 @@ static int sctp_gen_sack(struct sctp_association *asoc, int force,
          * unacknowledged DATA chunk. ...
          */
         if (!asoc->peer.sack_needed) {
-                /* We will need a SACK for the next packet.  */
-                asoc->peer.sack_needed = 1;
+                asoc->peer.sack_cnt++;
 
                 /* Set the SACK delay timeout based on the
                  * SACK delay for the last transport
                  * data was received from, or the default
                  * for the association.
                  */
-                if (trans)
+                if (trans) {
+                        /* We will need a SACK for the next packet.  */
+                        if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
+                                asoc->peer.sack_needed = 1;
+
                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
                                 trans->sackdelay;
-                else
+                } else {
+                        /* We will need a SACK for the next packet.  */
+                        if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
+                                asoc->peer.sack_needed = 1;
+
                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
                                 asoc->sackdelay;
+                }
 
                 /* Restart the SACK timer. */
                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
@@ -216,6 +224,7 @@ static int sctp_gen_sack(struct sctp_association *asoc, int force,
                         goto nomem;
 
                 asoc->peer.sack_needed = 0;
+                asoc->peer.sack_cnt = 0;
 
                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 
@@ -655,7 +664,7 @@ static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
                                  struct sctp_association *asoc,
                                  struct sctp_sackhdr *sackh)
 {
-        int err;
+        int err = 0;
 
         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
                 /* There are no more TSNs awaiting SACK.  */
@@ -663,11 +672,6 @@ static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
                                  asoc->state, asoc->ep, asoc, NULL,
                                  GFP_ATOMIC);
-        } else {
-                /* Windows may have opened, so we need
-                 * to check if we have DATA to transmit
-                 */
-                err = sctp_outq_flush(&asoc->outqueue, 0);
         }
 
         return err;
@@ -1472,8 +1476,15 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
                         break;
 
                 case SCTP_CMD_DISCARD_PACKET:
-                        /* We need to discard the whole packet.  */
+                        /* We need to discard the whole packet.
+                         * Uncork the queue since there might be
+                         * responses pending
+                         */
                         chunk->pdiscard = 1;
+                        if (asoc) {
+                                sctp_outq_uncork(&asoc->outqueue);
+                                local_cork = 0;
+                        }
                         break;
 
                 case SCTP_CMD_RTO_PENDING:
@@ -1544,8 +1555,15 @@ static int sctp_cmd_interpreter(sctp_event_t event_type,
         }
 
 out:
-        if (local_cork)
-                sctp_outq_uncork(&asoc->outqueue);
+        /* If this is in response to a received chunk, wait until
+         * we are done with the packet to open the queue so that we don't
+         * send multiple packets in response to a single request.
+         */
+        if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
+                if (chunk->end_of_packet || chunk->singleton)
+                        sctp_outq_uncork(&asoc->outqueue);
+        } else if (local_cork)
+                        sctp_outq_uncork(&asoc->outqueue);
         return error;
 nomem:
         error = -ENOMEM;