Add support for resource pooling to CMT.

An original version of the patch was developed by Martin Becke
and Thomas Dreibholz.

MFC after: 3 months

1 files changed, 119 insertions, 44 deletions

diff --git a/sys/netinet/sctp_cc_functions.c b/sys/netinet/sctp_cc_functions.c
index fc8811b..d1bfa00 100644
--- a/sys/netinet/sctp_cc_functions.c
+++ b/sys/netinet/sctp_cc_functions.c
@@ -66,6 +66,13 @@ sctp_set_initial_cc_param(struct sctp_tcb *stcb, struct sctp_nets *net)
 			cwnd_in_mtu = assoc->max_burst;
 		net->cwnd = (net->mtu - sizeof(struct sctphdr)) * cwnd_in_mtu;
 	}
+	if (stcb->asoc.sctp_cmt_on_off == 2) {
+		/* In case of resource pooling initialize appropriately */
+		net->cwnd /= assoc->numnets;
+		if (net->cwnd < (net->mtu - sizeof(struct sctphdr))) {
+			net->cwnd = net->mtu - sizeof(struct sctphdr);
+		}
+	}
 	net->ssthresh = assoc->peers_rwnd;
 
 	SDT_PROBE(sctp, cwnd, net, init,
@@ -82,7 +89,17 @@ sctp_cwnd_update_after_fr(struct sctp_tcb *stcb,
     struct sctp_association *asoc)
 {
 	struct sctp_nets *net;
-
+	uint32_t t_ssthresh, t_cwnd;
+
+	/* MT FIXME: Don't compute this over and over again */
+	t_ssthresh = 0;
+	t_cwnd = 0;
+	if (asoc->sctp_cmt_on_off == 2) {
+		TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
+			t_ssthresh += net->ssthresh;
+			t_cwnd += net->cwnd;
+		}
+	}
 	/*-
 	 * CMT fast recovery code. Need to debug. ((sctp_cmt_on_off > 0) &&
 	 * (net->fast_retran_loss_recovery == 0)))
@@ -101,9 +118,23 @@ sctp_cwnd_update_after_fr(struct sctp_tcb *stcb,
 				struct sctp_tmit_chunk *lchk;
 				int old_cwnd = net->cwnd;
 
-				net->ssthresh = net->cwnd / 2;
-				if (net->ssthresh < (net->mtu * 2)) {
-					net->ssthresh = 2 * net->mtu;
+				if (asoc->sctp_cmt_on_off == 2) {
+					net->ssthresh = (uint32_t) (((uint64_t) 4 *
+					    (uint64_t) net->mtu *
+					    (uint64_t) net->ssthresh) /
+					    (uint64_t) t_ssthresh);
+					if ((net->cwnd > t_cwnd / 2) &&
+					    (net->ssthresh < net->cwnd - t_cwnd / 2)) {
+						net->ssthresh = net->cwnd - t_cwnd / 2;
+					}
+					if (net->ssthresh < net->mtu) {
+						net->ssthresh = net->mtu;
+					}
+				} else {
+					net->ssthresh = net->cwnd / 2;
+					if (net->ssthresh < (net->mtu * 2)) {
+						net->ssthresh = 2 * net->mtu;
+					}
 				}
 				net->cwnd = net->ssthresh;
 				SDT_PROBE(sctp, cwnd, net, fr,
@@ -167,7 +198,17 @@ sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
 {
 	struct sctp_nets *net;
 	int old_cwnd;
-
+	uint32_t t_ssthresh, t_cwnd, incr;
+
+	/* MT FIXME: Don't compute this over and over again */
+	t_ssthresh = 0;
+	t_cwnd = 0;
+	if (stcb->asoc.sctp_cmt_on_off == 2) {
+		TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
+			t_ssthresh += net->ssthresh;
+			t_cwnd += net->cwnd;
+		}
+	}
 	/******************************/
 	/* update cwnd and Early FR   */
 	/******************************/
@@ -178,11 +219,8 @@ sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
 		 * CMT fast recovery code. Need to debug.
 		 */
 		if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
-			if (compare_with_wrap(asoc->last_acked_seq,
-			    net->fast_recovery_tsn, MAX_TSN) ||
-			    (asoc->last_acked_seq == net->fast_recovery_tsn) ||
-			    compare_with_wrap(net->pseudo_cumack, net->fast_recovery_tsn, MAX_TSN) ||
-			    (net->pseudo_cumack == net->fast_recovery_tsn)) {
+			if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
+			    SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
 				net->will_exit_fast_recovery = 1;
 			}
 		}
@@ -304,32 +342,39 @@ sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
 			if (net->cwnd <= net->ssthresh) {
 				/* We are in slow start */
 				if (net->flight_size + net->net_ack >= net->cwnd) {
-					if (net->net_ack > (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable))) {
-						old_cwnd = net->cwnd;
-						net->cwnd += (net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable));
-						SDT_PROBE(sctp, cwnd, net, ack,
-						    stcb->asoc.my_vtag,
-						    ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
-						    net,
-						    old_cwnd, net->cwnd);
-						if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
-							sctp_log_cwnd(stcb, net, net->mtu,
-							    SCTP_CWND_LOG_FROM_SS);
+					old_cwnd = net->cwnd;
+					if (stcb->asoc.sctp_cmt_on_off == 2) {
+						uint32_t limit;
+
+						limit = (uint32_t) (((uint64_t) net->mtu *
+						    (uint64_t) SCTP_BASE_SYSCTL(sctp_L2_abc_variable) *
+						    (uint64_t) net->ssthresh) /
+						    (uint64_t) t_ssthresh);
+						incr = (uint32_t) (((uint64_t) net->net_ack *
+						    (uint64_t) net->ssthresh) /
+						    (uint64_t) t_ssthresh);
+						if (incr > limit) {
+							incr = limit;
+						}
+						if (incr == 0) {
+							incr = 1;
 						}
 					} else {
-						old_cwnd = net->cwnd;
-						net->cwnd += net->net_ack;
-						SDT_PROBE(sctp, cwnd, net, ack,
-						    stcb->asoc.my_vtag,
-						    ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
-						    net,
-						    old_cwnd, net->cwnd);
-
-						if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
-							sctp_log_cwnd(stcb, net, net->net_ack,
-							    SCTP_CWND_LOG_FROM_SS);
+						incr = net->net_ack;
+						if (incr > net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable)) {
+							incr = net->mtu * SCTP_BASE_SYSCTL(sctp_L2_abc_variable);
 						}
 					}
+					net->cwnd += incr;
+					if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
+						sctp_log_cwnd(stcb, net, incr,
+						    SCTP_CWND_LOG_FROM_SS);
+					}
+					SDT_PROBE(sctp, cwnd, net, ack,
+					    stcb->asoc.my_vtag,
+					    ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
+					    net,
+					    old_cwnd, net->cwnd);
 				} else {
 					if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
 						sctp_log_cwnd(stcb, net, net->net_ack,
@@ -338,6 +383,8 @@ sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
 				}
 			} else {
 				/* We are in congestion avoidance */
+				uint32_t incr;
+
 				/*
 				 * Add to pba
 				 */
@@ -347,7 +394,17 @@ sctp_cwnd_update_after_sack(struct sctp_tcb *stcb,
 				    (net->partial_bytes_acked >= net->cwnd)) {
 					net->partial_bytes_acked -= net->cwnd;
 					old_cwnd = net->cwnd;
-					net->cwnd += net->mtu;
+					if (asoc->sctp_cmt_on_off == 2) {
+						incr = (uint32_t) (((uint64_t) net->mtu *
+						    (uint64_t) net->ssthresh) /
+						    (uint64_t) t_ssthresh);
+						if (incr == 0) {
+							incr = 1;
+						}
+					} else {
+						incr = net->mtu;
+					}
+					net->cwnd += incr;
 					SDT_PROBE(sctp, cwnd, net, ack,
 					    stcb->asoc.my_vtag,
 					    ((stcb->sctp_ep->sctp_lport << 16) | (stcb->rport)),
@@ -394,8 +451,32 @@ void
 sctp_cwnd_update_after_timeout(struct sctp_tcb *stcb, struct sctp_nets *net)
 {
 	int old_cwnd = net->cwnd;
+	uint32_t t_ssthresh, t_cwnd;
 
-	net->ssthresh = max(net->cwnd / 2, 4 * net->mtu);
+	/* MT FIXME: Don't compute this over and over again */
+	t_ssthresh = 0;
+	t_cwnd = 0;
+	if (stcb->asoc.sctp_cmt_on_off == 2) {
+		struct sctp_nets *lnet;
+
+		TAILQ_FOREACH(lnet, &stcb->asoc.nets, sctp_next) {
+			t_ssthresh += lnet->ssthresh;
+			t_cwnd += lnet->cwnd;
+		}
+		net->ssthresh = (uint32_t) (((uint64_t) 4 *
+		    (uint64_t) net->mtu *
+		    (uint64_t) net->ssthresh) /
+		    (uint64_t) t_ssthresh);
+		if ((net->cwnd > t_cwnd / 2) &&
+		    (net->ssthresh < net->cwnd - t_cwnd / 2)) {
+			net->ssthresh = net->cwnd - t_cwnd / 2;
+		}
+		if (net->ssthresh < net->mtu) {
+			net->ssthresh = net->mtu;
+		}
+	} else {
+		net->ssthresh = max(net->cwnd / 2, 4 * net->mtu);
+	}
 	net->cwnd = net->mtu;
 	net->partial_bytes_acked = 0;
 	SDT_PROBE(sctp, cwnd, net, to,
@@ -844,11 +925,8 @@ sctp_hs_cwnd_update_after_sack(struct sctp_tcb *stcb,
 		 * CMT fast recovery code. Need to debug.
 		 */
 		if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
-			if (compare_with_wrap(asoc->last_acked_seq,
-			    net->fast_recovery_tsn, MAX_TSN) ||
-			    (asoc->last_acked_seq == net->fast_recovery_tsn) ||
-			    compare_with_wrap(net->pseudo_cumack, net->fast_recovery_tsn, MAX_TSN) ||
-			    (net->pseudo_cumack == net->fast_recovery_tsn)) {
+			if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
+			    SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
 				net->will_exit_fast_recovery = 1;
 			}
 		}
@@ -1329,11 +1407,8 @@ sctp_htcp_cwnd_update_after_sack(struct sctp_tcb *stcb,
 		 * CMT fast recovery code. Need to debug.
 		 */
 		if (net->fast_retran_loss_recovery && net->new_pseudo_cumack) {
-			if (compare_with_wrap(asoc->last_acked_seq,
-			    net->fast_recovery_tsn, MAX_TSN) ||
-			    (asoc->last_acked_seq == net->fast_recovery_tsn) ||
-			    compare_with_wrap(net->pseudo_cumack, net->fast_recovery_tsn, MAX_TSN) ||
-			    (net->pseudo_cumack == net->fast_recovery_tsn)) {
+			if (SCTP_TSN_GE(asoc->last_acked_seq, net->fast_recovery_tsn) ||
+			    SCTP_TSN_GE(net->pseudo_cumack, net->fast_recovery_tsn)) {
 				net->will_exit_fast_recovery = 1;
 			}
 		}