The result of a joint work between rrs@ and myself at the IETF:

* Decouple the path supervision using a separate HB timer per path.
* Add support for potentially failed state.
* Bring back RTO.min to 1 second.
* Accept packets on IP-addresses already announced via an ASCONF
* While there: do some cleanups.

Approved by: re@
MFC after: 2 months.

1 files changed, 127 insertions, 48 deletions

diff --git a/sys/netinet/sctp_indata.c b/sys/netinet/sctp_indata.c
index e142a3e..48b79fb 100644
--- a/sys/netinet/sctp_indata.c
+++ b/sys/netinet/sctp_indata.c
@@ -2434,7 +2434,8 @@ sctp_sack_check(struct sctp_tcb *stcb, int was_a_gap, int *abort_flag)
 			sctp_timer_stop(SCTP_TIMER_TYPE_RECV,
 			    stcb->sctp_ep, stcb, NULL, SCTP_FROM_SCTP_INDATA + SCTP_LOC_18);
 		}
-		sctp_send_shutdown(stcb, stcb->asoc.primary_destination);
+		sctp_send_shutdown(stcb,
+		    ((stcb->asoc.alternate) ? stcb->asoc.alternate : stcb->asoc.primary_destination));
 		sctp_send_sack(stcb, SCTP_SO_NOT_LOCKED);
 	} else {
 		int is_a_gap;
@@ -4054,9 +4055,50 @@ sctp_express_handle_sack(struct sctp_tcb *stcb, uint32_t cumack,
 	}
 
 	/* JRS - Use the congestion control given in the CC module */
-	if ((asoc->last_acked_seq != cumack) && (ecne_seen == 0))
+	if ((asoc->last_acked_seq != cumack) && (ecne_seen == 0)) {
+		TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
+			if (net->net_ack2 > 0) {
+				/*
+				 * Karn's rule applies to clearing error
+				 * count, this is optional.
+				 */
+				net->error_count = 0;
+				if (!(net->dest_state & SCTP_ADDR_REACHABLE)) {
+					/* addr came good */
+					net->dest_state |= SCTP_ADDR_REACHABLE;
+					sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
+					    SCTP_RECEIVED_SACK, (void *)net, SCTP_SO_NOT_LOCKED);
+				}
+				if (net == stcb->asoc.primary_destination) {
+					if (stcb->asoc.alternate) {
+						/*
+						 * release the alternate,
+						 * primary is good
+						 */
+						sctp_free_remote_addr(stcb->asoc.alternate);
+						stcb->asoc.alternate = NULL;
+					}
+				}
+				if (net->dest_state & SCTP_ADDR_PF) {
+					net->dest_state &= ~SCTP_ADDR_PF;
+					sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_3);
+					sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
+					asoc->cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
+					/* Done with this net */
+					net->net_ack = 0;
+				}
+				/* restore any doubled timers */
+				net->RTO = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
+				if (net->RTO < stcb->asoc.minrto) {
+					net->RTO = stcb->asoc.minrto;
+				}
+				if (net->RTO > stcb->asoc.maxrto) {
+					net->RTO = stcb->asoc.maxrto;
+				}
+			}
+		}
 		asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, 1, 0, 0);
-
+	}
 	asoc->last_acked_seq = cumack;
 
 	if (TAILQ_EMPTY(&asoc->sent_queue)) {
@@ -4127,13 +4169,6 @@ again:
 				    stcb, net,
 				    SCTP_FROM_SCTP_INDATA + SCTP_LOC_22);
 			}
-			if (SCTP_BASE_SYSCTL(sctp_early_fr)) {
-				if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
-					SCTP_STAT_INCR(sctps_earlyfrstpidsck4);
-					sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
-					    SCTP_FROM_SCTP_INDATA + SCTP_LOC_23);
-				}
-			}
 		}
 	}
 	if ((j == 0) &&
@@ -4222,6 +4257,8 @@ again:
 				stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_24;
 				sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_RESPONSE_TO_USER_REQ, oper, SCTP_SO_NOT_LOCKED);
 			} else {
+				struct sctp_nets *netp;
+
 				if ((SCTP_GET_STATE(asoc) == SCTP_STATE_OPEN) ||
 				    (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
 					SCTP_STAT_DECR_GAUGE32(sctps_currestab);
@@ -4229,26 +4266,36 @@ again:
 				SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_SENT);
 				SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
 				sctp_stop_timers_for_shutdown(stcb);
-				sctp_send_shutdown(stcb,
-				    stcb->asoc.primary_destination);
+				if (asoc->alternate) {
+					netp = asoc->alternate;
+				} else {
+					netp = asoc->primary_destination;
+				}
+				sctp_send_shutdown(stcb, netp);
 				sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
-				    stcb->sctp_ep, stcb, asoc->primary_destination);
+				    stcb->sctp_ep, stcb, netp);
 				sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
-				    stcb->sctp_ep, stcb, asoc->primary_destination);
+				    stcb->sctp_ep, stcb, netp);
 			}
 		} else if ((SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
 		    (asoc->stream_queue_cnt == 0)) {
+			struct sctp_nets *netp;
+
+			if (asoc->alternate) {
+				netp = asoc->alternate;
+			} else {
+				netp = asoc->primary_destination;
+			}
 			if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
 				goto abort_out_now;
 			}
 			SCTP_STAT_DECR_GAUGE32(sctps_currestab);
 			SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_ACK_SENT);
 			SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
-			sctp_send_shutdown_ack(stcb,
-			    stcb->asoc.primary_destination);
+			sctp_send_shutdown_ack(stcb, netp);
 			sctp_stop_timers_for_shutdown(stcb);
 			sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
-			    stcb->sctp_ep, stcb, asoc->primary_destination);
+			    stcb->sctp_ep, stcb, netp);
 		}
 	}
 	/*********************************************/
@@ -4380,7 +4427,7 @@ sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
 		    num_dup,
 		    SCTP_LOG_NEW_SACK);
 	}
-	if ((num_dup) && (SCTP_BASE_SYSCTL(sctp_logging_level) & (SCTP_FR_LOGGING_ENABLE | SCTP_EARLYFR_LOGGING_ENABLE))) {
+	if ((num_dup) && (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE)) {
 		uint16_t i;
 		uint32_t *dupdata, dblock;
 
@@ -4468,13 +4515,6 @@ sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
 		TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
 			sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
 			    stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_26);
-			if (SCTP_BASE_SYSCTL(sctp_early_fr)) {
-				if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
-					SCTP_STAT_INCR(sctps_earlyfrstpidsck1);
-					sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
-					    SCTP_FROM_SCTP_INDATA + SCTP_LOC_26);
-				}
-			}
 			net->partial_bytes_acked = 0;
 			net->flight_size = 0;
 		}
@@ -4830,20 +4870,54 @@ sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
 		asoc->saw_sack_with_nr_frags = 0;
 
 	/* JRS - Use the congestion control given in the CC module */
-	if (ecne_seen == 0)
+	if (ecne_seen == 0) {
+		TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
+			if (net->net_ack2 > 0) {
+				/*
+				 * Karn's rule applies to clearing error
+				 * count, this is optional.
+				 */
+				net->error_count = 0;
+				if (!(net->dest_state & SCTP_ADDR_REACHABLE)) {
+					/* addr came good */
+					net->dest_state |= SCTP_ADDR_REACHABLE;
+					sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
+					    SCTP_RECEIVED_SACK, (void *)net, SCTP_SO_NOT_LOCKED);
+				}
+				if (net == stcb->asoc.primary_destination) {
+					if (stcb->asoc.alternate) {
+						/*
+						 * release the alternate,
+						 * primary is good
+						 */
+						sctp_free_remote_addr(stcb->asoc.alternate);
+						stcb->asoc.alternate = NULL;
+					}
+				}
+				if (net->dest_state & SCTP_ADDR_PF) {
+					net->dest_state &= ~SCTP_ADDR_PF;
+					sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_3);
+					sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
+					asoc->cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
+					/* Done with this net */
+					net->net_ack = 0;
+				}
+				/* restore any doubled timers */
+				net->RTO = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
+				if (net->RTO < stcb->asoc.minrto) {
+					net->RTO = stcb->asoc.minrto;
+				}
+				if (net->RTO > stcb->asoc.maxrto) {
+					net->RTO = stcb->asoc.maxrto;
+				}
+			}
+		}
 		asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, accum_moved, reneged_all, will_exit_fast_recovery);
-
+	}
 	if (TAILQ_EMPTY(&asoc->sent_queue)) {
 		/* nothing left in-flight */
 		TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
 			/* stop all timers */
-			if (SCTP_BASE_SYSCTL(sctp_early_fr)) {
-				if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
-					SCTP_STAT_INCR(sctps_earlyfrstpidsck4);
-					sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
-					    SCTP_FROM_SCTP_INDATA + SCTP_LOC_29);
-				}
-			}
 			sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
 			    stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_30);
 			net->flight_size = 0;
@@ -4918,6 +4992,13 @@ sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
 				sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_RESPONSE_TO_USER_REQ, oper, SCTP_SO_NOT_LOCKED);
 				return;
 			} else {
+				struct sctp_nets *netp;
+
+				if (asoc->alternate) {
+					netp = asoc->alternate;
+				} else {
+					netp = asoc->primary_destination;
+				}
 				if ((SCTP_GET_STATE(asoc) == SCTP_STATE_OPEN) ||
 				    (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
 					SCTP_STAT_DECR_GAUGE32(sctps_currestab);
@@ -4925,27 +5006,32 @@ sctp_handle_sack(struct mbuf *m, int offset_seg, int offset_dup,
 				SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_SENT);
 				SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
 				sctp_stop_timers_for_shutdown(stcb);
-				sctp_send_shutdown(stcb,
-				    stcb->asoc.primary_destination);
+				sctp_send_shutdown(stcb, netp);
 				sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
-				    stcb->sctp_ep, stcb, asoc->primary_destination);
+				    stcb->sctp_ep, stcb, netp);
 				sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
-				    stcb->sctp_ep, stcb, asoc->primary_destination);
+				    stcb->sctp_ep, stcb, netp);
 			}
 			return;
 		} else if ((SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
 		    (asoc->stream_queue_cnt == 0)) {
+			struct sctp_nets *netp;
+
+			if (asoc->alternate) {
+				netp = asoc->alternate;
+			} else {
+				netp = asoc->primary_destination;
+			}
 			if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
 				goto abort_out_now;
 			}
 			SCTP_STAT_DECR_GAUGE32(sctps_currestab);
 			SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_ACK_SENT);
 			SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
-			sctp_send_shutdown_ack(stcb,
-			    stcb->asoc.primary_destination);
+			sctp_send_shutdown_ack(stcb, netp);
 			sctp_stop_timers_for_shutdown(stcb);
 			sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
-			    stcb->sctp_ep, stcb, asoc->primary_destination);
+			    stcb->sctp_ep, stcb, netp);
 			return;
 		}
 	}
@@ -5056,13 +5142,6 @@ again:
 				    stcb, net,
 				    SCTP_FROM_SCTP_INDATA + SCTP_LOC_22);
 			}
-			if (SCTP_BASE_SYSCTL(sctp_early_fr)) {
-				if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
-					SCTP_STAT_INCR(sctps_earlyfrstpidsck4);
-					sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
-					    SCTP_FROM_SCTP_INDATA + SCTP_LOC_23);
-				}
-			}
 		}
 	}
 	if ((j == 0) &&