sctp: Cleanup stream schedulers.

No functional change intended.

MFC after:	1 week

4 files changed, 106 insertions, 129 deletions

diff --git a/sys/netinet/sctp_output.c b/sys/netinet/sctp_output.c
index 36339ac0f2b1..cad15be7a57b 100644
--- a/sys/netinet/sctp_output.c
+++ b/sys/netinet/sctp_output.c
@@ -12176,7 +12176,7 @@ sctp_send_str_reset_req(struct sctp_tcb *stcb,
 		 * initializing the new stuff.
 		 */
 		SCTP_TCB_SEND_LOCK(stcb);
-		stcb->asoc.ss_functions.sctp_ss_clear(stcb, &stcb->asoc, 0);
+		stcb->asoc.ss_functions.sctp_ss_clear(stcb, &stcb->asoc, false);
 		for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
 			TAILQ_INIT(&stcb->asoc.strmout[i].outqueue);
 			/* FIX ME FIX ME */
diff --git a/sys/netinet/sctp_ss_functions.c b/sys/netinet/sctp_ss_functions.c
index 9d877568bcf1..ff108eb0eb33 100644
--- a/sys/netinet/sctp_ss_functions.c
+++ b/sys/netinet/sctp_ss_functions.c
@@ -54,6 +54,7 @@ sctp_ss_default_init(struct sctp_tcb *stcb, struct sctp_association *asoc)
 	uint16_t i;
 
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
+
 	asoc->ss_data.locked_on_sending = NULL;
 	asoc->ss_data.last_out_stream = NULL;
 	TAILQ_INIT(&asoc->ss_data.out.wheel);
@@ -72,7 +73,7 @@ sctp_ss_default_init(struct sctp_tcb *stcb, struct sctp_association *asoc)
 
 static void
 sctp_ss_default_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
-    int clear_values SCTP_UNUSED)
+    bool clear_values SCTP_UNUSED)
 {
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
@@ -80,9 +81,8 @@ sctp_ss_default_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
 		struct sctp_stream_out *strq;
 
 		strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
-		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.rr.next_spoke);
-		strq->ss_params.rr.next_spoke.tqe_next = NULL;
-		strq->ss_params.rr.next_spoke.tqe_prev = NULL;
+		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.ss.rr.next_spoke);
+		strq->ss_params.scheduled = false;
 	}
 	asoc->ss_data.last_out_stream = NULL;
 	return;
@@ -99,8 +99,7 @@ sctp_ss_default_init_stream(struct sctp_tcb *stcb, struct sctp_stream_out *strq,
 			stcb->asoc.ss_data.last_out_stream = strq;
 		}
 	}
-	strq->ss_params.rr.next_spoke.tqe_next = NULL;
-	strq->ss_params.rr.next_spoke.tqe_prev = NULL;
+	strq->ss_params.scheduled = false;
 	return;
 }
 
@@ -112,23 +111,18 @@ sctp_ss_default_add(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
 	/* Add to wheel if not already on it and stream queue not empty */
-	if (!TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.rr.next_spoke.tqe_next == NULL) &&
-	    (strq->ss_params.rr.next_spoke.tqe_prev == NULL)) {
+	if (!TAILQ_EMPTY(&strq->outqueue) && !strq->ss_params.scheduled) {
 		TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel,
-		    strq, ss_params.rr.next_spoke);
+		    strq, ss_params.ss.rr.next_spoke);
+		strq->ss_params.scheduled = true;
 	}
 	return;
 }
 
-static int
+static bool
 sctp_ss_default_is_empty(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_association *asoc)
 {
-	if (TAILQ_EMPTY(&asoc->ss_data.out.wheel)) {
-		return (1);
-	} else {
-		return (0);
-	}
+	return (TAILQ_EMPTY(&asoc->ss_data.out.wheel));
 }
 
 static void
@@ -142,13 +136,11 @@ sctp_ss_default_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	 * Remove from wheel if stream queue is empty and actually is on the
 	 * wheel
 	 */
-	if (TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.rr.next_spoke.tqe_next != NULL ||
-	    strq->ss_params.rr.next_spoke.tqe_prev != NULL)) {
+	if (TAILQ_EMPTY(&strq->outqueue) && strq->ss_params.scheduled) {
 		if (asoc->ss_data.last_out_stream == strq) {
 			asoc->ss_data.last_out_stream = TAILQ_PREV(asoc->ss_data.last_out_stream,
 			    sctpwheel_listhead,
-			    ss_params.rr.next_spoke);
+			    ss_params.ss.rr.next_spoke);
 			if (asoc->ss_data.last_out_stream == NULL) {
 				asoc->ss_data.last_out_stream = TAILQ_LAST(&asoc->ss_data.out.wheel,
 				    sctpwheel_listhead);
@@ -157,9 +149,8 @@ sctp_ss_default_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 				asoc->ss_data.last_out_stream = NULL;
 			}
 		}
-		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.rr.next_spoke);
-		strq->ss_params.rr.next_spoke.tqe_next = NULL;
-		strq->ss_params.rr.next_spoke.tqe_prev = NULL;
+		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.ss.rr.next_spoke);
+		strq->ss_params.scheduled = false;
 	}
 	return;
 }
@@ -179,7 +170,7 @@ default_again:
 	if (strqt == NULL) {
 		strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 	} else {
-		strq = TAILQ_NEXT(strqt, ss_params.rr.next_spoke);
+		strq = TAILQ_NEXT(strqt, ss_params.ss.rr.next_spoke);
 		if (strq == NULL) {
 			strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 		}
@@ -257,24 +248,24 @@ sctp_ss_default_set_value(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_associa
 	return (-1);
 }
 
-static int
+static bool
 sctp_ss_default_is_user_msgs_incomplete(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_association *asoc)
 {
 	struct sctp_stream_out *strq;
 	struct sctp_stream_queue_pending *sp;
 
 	if (asoc->stream_queue_cnt != 1) {
-		return (0);
+		return (false);
 	}
 	strq = asoc->ss_data.locked_on_sending;
 	if (strq == NULL) {
-		return (0);
+		return (false);
 	}
 	sp = TAILQ_FIRST(&strq->outqueue);
 	if (sp == NULL) {
-		return (0);
+		return (false);
 	}
-	return (!sp->msg_is_complete);
+	return (sp->msg_is_complete == 0);
 }
 
 /*
@@ -290,22 +281,21 @@ sctp_ss_rr_add(struct sctp_tcb *stcb, struct sctp_association *asoc,
 
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
-	if (!TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.rr.next_spoke.tqe_next == NULL) &&
-	    (strq->ss_params.rr.next_spoke.tqe_prev == NULL)) {
+	if (!TAILQ_EMPTY(&strq->outqueue) && !strq->ss_params.scheduled) {
 		if (TAILQ_EMPTY(&asoc->ss_data.out.wheel)) {
-			TAILQ_INSERT_HEAD(&asoc->ss_data.out.wheel, strq, ss_params.rr.next_spoke);
+			TAILQ_INSERT_HEAD(&asoc->ss_data.out.wheel, strq, ss_params.ss.rr.next_spoke);
 		} else {
 			strqt = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 			while (strqt != NULL && (strqt->sid < strq->sid)) {
-				strqt = TAILQ_NEXT(strqt, ss_params.rr.next_spoke);
+				strqt = TAILQ_NEXT(strqt, ss_params.ss.rr.next_spoke);
 			}
 			if (strqt != NULL) {
-				TAILQ_INSERT_BEFORE(strqt, strq, ss_params.rr.next_spoke);
+				TAILQ_INSERT_BEFORE(strqt, strq, ss_params.ss.rr.next_spoke);
 			} else {
-				TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel, strq, ss_params.rr.next_spoke);
+				TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel, strq, ss_params.ss.rr.next_spoke);
 			}
 		}
+		strq->ss_params.scheduled = true;
 	}
 	return;
 }
@@ -334,7 +324,7 @@ rrp_again:
 	if (strqt == NULL) {
 		strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 	} else {
-		strq = TAILQ_NEXT(strqt, ss_params.rr.next_spoke);
+		strq = TAILQ_NEXT(strqt, ss_params.ss.rr.next_spoke);
 		if (strq == NULL) {
 			strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 		}
@@ -372,7 +362,7 @@ rrp_again:
  */
 static void
 sctp_ss_prio_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
-    int clear_values)
+    bool clear_values)
 {
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
@@ -381,11 +371,10 @@ sctp_ss_prio_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
 
 		strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 		if (clear_values) {
-			strq->ss_params.prio.priority = 0;
+			strq->ss_params.ss.prio.priority = 0;
 		}
-		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.prio.next_spoke);
-		strq->ss_params.prio.next_spoke.tqe_next = NULL;
-		strq->ss_params.prio.next_spoke.tqe_prev = NULL;
+		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.ss.prio.next_spoke);
+		strq->ss_params.scheduled = false;
 	}
 	asoc->ss_data.last_out_stream = NULL;
 	return;
@@ -402,12 +391,11 @@ sctp_ss_prio_init_stream(struct sctp_tcb *stcb, struct sctp_stream_out *strq, st
 			stcb->asoc.ss_data.last_out_stream = strq;
 		}
 	}
-	strq->ss_params.prio.next_spoke.tqe_next = NULL;
-	strq->ss_params.prio.next_spoke.tqe_prev = NULL;
+	strq->ss_params.scheduled = false;
 	if (with_strq != NULL) {
-		strq->ss_params.prio.priority = with_strq->ss_params.prio.priority;
+		strq->ss_params.ss.prio.priority = with_strq->ss_params.ss.prio.priority;
 	} else {
-		strq->ss_params.prio.priority = 0;
+		strq->ss_params.ss.prio.priority = 0;
 	}
 	return;
 }
@@ -421,22 +409,21 @@ sctp_ss_prio_add(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
 	/* Add to wheel if not already on it and stream queue not empty */
-	if (!TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.prio.next_spoke.tqe_next == NULL) &&
-	    (strq->ss_params.prio.next_spoke.tqe_prev == NULL)) {
+	if (!TAILQ_EMPTY(&strq->outqueue) && !strq->ss_params.scheduled) {
 		if (TAILQ_EMPTY(&asoc->ss_data.out.wheel)) {
-			TAILQ_INSERT_HEAD(&asoc->ss_data.out.wheel, strq, ss_params.prio.next_spoke);
+			TAILQ_INSERT_HEAD(&asoc->ss_data.out.wheel, strq, ss_params.ss.prio.next_spoke);
 		} else {
 			strqt = TAILQ_FIRST(&asoc->ss_data.out.wheel);
-			while (strqt != NULL && strqt->ss_params.prio.priority < strq->ss_params.prio.priority) {
-				strqt = TAILQ_NEXT(strqt, ss_params.prio.next_spoke);
+			while (strqt != NULL && strqt->ss_params.ss.prio.priority < strq->ss_params.ss.prio.priority) {
+				strqt = TAILQ_NEXT(strqt, ss_params.ss.prio.next_spoke);
 			}
 			if (strqt != NULL) {
-				TAILQ_INSERT_BEFORE(strqt, strq, ss_params.prio.next_spoke);
+				TAILQ_INSERT_BEFORE(strqt, strq, ss_params.ss.prio.next_spoke);
 			} else {
-				TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel, strq, ss_params.prio.next_spoke);
+				TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel, strq, ss_params.ss.prio.next_spoke);
 			}
 		}
+		strq->ss_params.scheduled = true;
 	}
 	return;
 }
@@ -451,12 +438,11 @@ sctp_ss_prio_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	 * Remove from wheel if stream queue is empty and actually is on the
 	 * wheel
 	 */
-	if (TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.prio.next_spoke.tqe_next != NULL ||
-	    strq->ss_params.prio.next_spoke.tqe_prev != NULL)) {
+	if (TAILQ_EMPTY(&strq->outqueue) && strq->ss_params.scheduled) {
 		if (asoc->ss_data.last_out_stream == strq) {
-			asoc->ss_data.last_out_stream = TAILQ_PREV(asoc->ss_data.last_out_stream, sctpwheel_listhead,
-			    ss_params.prio.next_spoke);
+			asoc->ss_data.last_out_stream = TAILQ_PREV(asoc->ss_data.last_out_stream,
+			    sctpwheel_listhead,
+			    ss_params.ss.prio.next_spoke);
 			if (asoc->ss_data.last_out_stream == NULL) {
 				asoc->ss_data.last_out_stream = TAILQ_LAST(&asoc->ss_data.out.wheel,
 				    sctpwheel_listhead);
@@ -465,9 +451,8 @@ sctp_ss_prio_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 				asoc->ss_data.last_out_stream = NULL;
 			}
 		}
-		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.prio.next_spoke);
-		strq->ss_params.prio.next_spoke.tqe_next = NULL;
-		strq->ss_params.prio.next_spoke.tqe_prev = NULL;
+		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.ss.prio.next_spoke);
+		strq->ss_params.scheduled = false;
 	}
 	return;
 }
@@ -487,9 +472,9 @@ prio_again:
 	if (strqt == NULL) {
 		strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 	} else {
-		strqn = TAILQ_NEXT(strqt, ss_params.prio.next_spoke);
+		strqn = TAILQ_NEXT(strqt, ss_params.ss.prio.next_spoke);
 		if (strqn != NULL &&
-		    strqn->ss_params.prio.priority == strqt->ss_params.prio.priority) {
+		    strqn->ss_params.ss.prio.priority == strqt->ss_params.ss.prio.priority) {
 			strq = strqn;
 		} else {
 			strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
@@ -528,7 +513,7 @@ sctp_ss_prio_get_value(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_associatio
 	if (strq == NULL) {
 		return (-1);
 	}
-	*value = strq->ss_params.prio.priority;
+	*value = strq->ss_params.ss.prio.priority;
 	return (1);
 }
 
@@ -539,7 +524,7 @@ sctp_ss_prio_set_value(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	if (strq == NULL) {
 		return (-1);
 	}
-	strq->ss_params.prio.priority = value;
+	strq->ss_params.ss.prio.priority = value;
 	sctp_ss_prio_remove(stcb, asoc, strq, NULL);
 	sctp_ss_prio_add(stcb, asoc, strq, NULL);
 	return (1);
@@ -551,7 +536,7 @@ sctp_ss_prio_set_value(struct sctp_tcb *stcb, struct sctp_association *asoc,
  */
 static void
 sctp_ss_fb_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
-    int clear_values)
+    bool clear_values)
 {
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
@@ -560,11 +545,10 @@ sctp_ss_fb_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
 
 		strq = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 		if (clear_values) {
-			strq->ss_params.fb.rounds = -1;
+			strq->ss_params.ss.fb.rounds = -1;
 		}
-		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.fb.next_spoke);
-		strq->ss_params.fb.next_spoke.tqe_next = NULL;
-		strq->ss_params.fb.next_spoke.tqe_prev = NULL;
+		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.ss.fb.next_spoke);
+		strq->ss_params.scheduled = false;
 	}
 	asoc->ss_data.last_out_stream = NULL;
 	return;
@@ -581,12 +565,11 @@ sctp_ss_fb_init_stream(struct sctp_tcb *stcb, struct sctp_stream_out *strq, stru
 			stcb->asoc.ss_data.last_out_stream = strq;
 		}
 	}
-	strq->ss_params.fb.next_spoke.tqe_next = NULL;
-	strq->ss_params.fb.next_spoke.tqe_prev = NULL;
+	strq->ss_params.scheduled = false;
 	if (with_strq != NULL) {
-		strq->ss_params.fb.rounds = with_strq->ss_params.fb.rounds;
+		strq->ss_params.ss.fb.rounds = with_strq->ss_params.ss.fb.rounds;
 	} else {
-		strq->ss_params.fb.rounds = -1;
+		strq->ss_params.ss.fb.rounds = -1;
 	}
 	return;
 }
@@ -597,12 +580,11 @@ sctp_ss_fb_add(struct sctp_tcb *stcb, struct sctp_association *asoc,
 {
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
-	if (!TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.fb.next_spoke.tqe_next == NULL) &&
-	    (strq->ss_params.fb.next_spoke.tqe_prev == NULL)) {
-		if (strq->ss_params.fb.rounds < 0)
-			strq->ss_params.fb.rounds = TAILQ_FIRST(&strq->outqueue)->length;
-		TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel, strq, ss_params.fb.next_spoke);
+	if (!TAILQ_EMPTY(&strq->outqueue) && !strq->ss_params.scheduled) {
+		if (strq->ss_params.ss.fb.rounds < 0)
+			strq->ss_params.ss.fb.rounds = TAILQ_FIRST(&strq->outqueue)->length;
+		TAILQ_INSERT_TAIL(&asoc->ss_data.out.wheel, strq, ss_params.ss.fb.next_spoke);
+		strq->ss_params.scheduled = true;
 	}
 	return;
 }
@@ -617,12 +599,11 @@ sctp_ss_fb_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	 * Remove from wheel if stream queue is empty and actually is on the
 	 * wheel
 	 */
-	if (TAILQ_EMPTY(&strq->outqueue) &&
-	    (strq->ss_params.fb.next_spoke.tqe_next != NULL ||
-	    strq->ss_params.fb.next_spoke.tqe_prev != NULL)) {
+	if (TAILQ_EMPTY(&strq->outqueue) && strq->ss_params.scheduled) {
 		if (asoc->ss_data.last_out_stream == strq) {
-			asoc->ss_data.last_out_stream = TAILQ_PREV(asoc->ss_data.last_out_stream, sctpwheel_listhead,
-			    ss_params.fb.next_spoke);
+			asoc->ss_data.last_out_stream = TAILQ_PREV(asoc->ss_data.last_out_stream,
+			    sctpwheel_listhead,
+			    ss_params.ss.fb.next_spoke);
 			if (asoc->ss_data.last_out_stream == NULL) {
 				asoc->ss_data.last_out_stream = TAILQ_LAST(&asoc->ss_data.out.wheel,
 				    sctpwheel_listhead);
@@ -631,9 +612,8 @@ sctp_ss_fb_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 				asoc->ss_data.last_out_stream = NULL;
 			}
 		}
-		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.fb.next_spoke);
-		strq->ss_params.fb.next_spoke.tqe_next = NULL;
-		strq->ss_params.fb.next_spoke.tqe_prev = NULL;
+		TAILQ_REMOVE(&asoc->ss_data.out.wheel, strq, ss_params.ss.fb.next_spoke);
+		strq->ss_params.scheduled = false;
 	}
 	return;
 }
@@ -651,7 +631,7 @@ sctp_ss_fb_select(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_nets *net,
 	    TAILQ_FIRST(&asoc->ss_data.out.wheel) == TAILQ_LAST(&asoc->ss_data.out.wheel, sctpwheel_listhead)) {
 		strqt = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 	} else {
-		strqt = TAILQ_NEXT(asoc->ss_data.last_out_stream, ss_params.fb.next_spoke);
+		strqt = TAILQ_NEXT(asoc->ss_data.last_out_stream, ss_params.ss.fb.next_spoke);
 	}
 	do {
 		if ((strqt != NULL) &&
@@ -660,13 +640,14 @@ sctp_ss_fb_select(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_nets *net,
 		    (net == NULL || (TAILQ_FIRST(&strqt->outqueue) && TAILQ_FIRST(&strqt->outqueue)->net == NULL) ||
 		    (net != NULL && TAILQ_FIRST(&strqt->outqueue) && TAILQ_FIRST(&strqt->outqueue)->net != NULL &&
 		    TAILQ_FIRST(&strqt->outqueue)->net == net))))) {
-			if ((strqt->ss_params.fb.rounds >= 0) && (strq == NULL ||
-			    strqt->ss_params.fb.rounds < strq->ss_params.fb.rounds)) {
+			if ((strqt->ss_params.ss.fb.rounds >= 0) &&
+			    ((strq == NULL) ||
+			    (strqt->ss_params.ss.fb.rounds < strq->ss_params.ss.fb.rounds))) {
 				strq = strqt;
 			}
 		}
 		if (strqt != NULL) {
-			strqt = TAILQ_NEXT(strqt, ss_params.fb.next_spoke);
+			strqt = TAILQ_NEXT(strqt, ss_params.ss.fb.next_spoke);
 		} else {
 			strqt = TAILQ_FIRST(&asoc->ss_data.out.wheel);
 		}
@@ -693,16 +674,16 @@ sctp_ss_fb_scheduled(struct sctp_tcb *stcb, struct sctp_nets *net SCTP_UNUSED,
 	} else {
 		stcb->asoc.ss_data.locked_on_sending = NULL;
 	}
-	subtract = strq->ss_params.fb.rounds;
-	TAILQ_FOREACH(strqt, &asoc->ss_data.out.wheel, ss_params.fb.next_spoke) {
-		strqt->ss_params.fb.rounds -= subtract;
-		if (strqt->ss_params.fb.rounds < 0)
-			strqt->ss_params.fb.rounds = 0;
+	subtract = strq->ss_params.ss.fb.rounds;
+	TAILQ_FOREACH(strqt, &asoc->ss_data.out.wheel, ss_params.ss.fb.next_spoke) {
+		strqt->ss_params.ss.fb.rounds -= subtract;
+		if (strqt->ss_params.ss.fb.rounds < 0)
+			strqt->ss_params.ss.fb.rounds = 0;
 	}
 	if (TAILQ_FIRST(&strq->outqueue)) {
-		strq->ss_params.fb.rounds = TAILQ_FIRST(&strq->outqueue)->length;
+		strq->ss_params.ss.fb.rounds = TAILQ_FIRST(&strq->outqueue)->length;
 	} else {
-		strq->ss_params.fb.rounds = -1;
+		strq->ss_params.ss.fb.rounds = -1;
 	}
 	asoc->ss_data.last_out_stream = strq;
 	return;
@@ -754,7 +735,7 @@ sctp_ss_fcfs_init(struct sctp_tcb *stcb, struct sctp_association *asoc)
 
 static void
 sctp_ss_fcfs_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
-    int clear_values SCTP_UNUSED)
+    bool clear_values SCTP_UNUSED)
 {
 	struct sctp_stream_queue_pending *sp;
 
@@ -763,8 +744,7 @@ sctp_ss_fcfs_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,
 	while (!TAILQ_EMPTY(&asoc->ss_data.out.list)) {
 		sp = TAILQ_FIRST(&asoc->ss_data.out.list);
 		TAILQ_REMOVE(&asoc->ss_data.out.list, sp, ss_next);
-		sp->ss_next.tqe_next = NULL;
-		sp->ss_next.tqe_prev = NULL;
+		sp->scheduled = false;
 	}
 	asoc->ss_data.last_out_stream = NULL;
 	return;
@@ -781,8 +761,7 @@ sctp_ss_fcfs_init_stream(struct sctp_tcb *stcb, struct sctp_stream_out *strq, st
 			stcb->asoc.ss_data.last_out_stream = strq;
 		}
 	}
-	strq->ss_params.fb.next_spoke.tqe_next = NULL;
-	strq->ss_params.fb.next_spoke.tqe_prev = NULL;
+	strq->ss_params.scheduled = false;
 	return;
 }
 
@@ -792,21 +771,17 @@ sctp_ss_fcfs_add(struct sctp_tcb *stcb, struct sctp_association *asoc,
 {
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
-	if (sp && (sp->ss_next.tqe_next == NULL) &&
-	    (sp->ss_next.tqe_prev == NULL)) {
+	if (!sp->scheduled) {
 		TAILQ_INSERT_TAIL(&asoc->ss_data.out.list, sp, ss_next);
+		sp->scheduled = true;
 	}
 	return;
 }
 
-static int
+static bool
 sctp_ss_fcfs_is_empty(struct sctp_tcb *stcb SCTP_UNUSED, struct sctp_association *asoc)
 {
-	if (TAILQ_EMPTY(&asoc->ss_data.out.list)) {
-		return (1);
-	} else {
-		return (0);
-	}
+	return (TAILQ_EMPTY(&asoc->ss_data.out.list));
 }
 
 static void
@@ -815,12 +790,9 @@ sctp_ss_fcfs_remove(struct sctp_tcb *stcb, struct sctp_association *asoc,
 {
 	SCTP_TCB_SEND_LOCK_ASSERT(stcb);
 
-	if (sp &&
-	    ((sp->ss_next.tqe_next != NULL) ||
-	    (sp->ss_next.tqe_prev != NULL))) {
+	if (sp->scheduled) {
 		TAILQ_REMOVE(&asoc->ss_data.out.list, sp, ss_next);
-		sp->ss_next.tqe_next = NULL;
-		sp->ss_next.tqe_prev = NULL;
+		sp->scheduled = false;
 	}
 	return;
 }
diff --git a/sys/netinet/sctp_structs.h b/sys/netinet/sctp_structs.h
index 2f0ae4c45b24..026e3319dd23 100644
--- a/sys/netinet/sctp_structs.h
+++ b/sys/netinet/sctp_structs.h
@@ -505,6 +505,7 @@ struct sctp_queued_to_read {	/* sinfo structure Pluse more */
  * the user is in the explict MSG_EOR mode
  * and wrote some data, but has not completed
  * sending.
+ * ss_next and scheduled are only used by the FCFS stream scheduler.
  */
 struct sctp_stream_queue_pending {
 	struct mbuf *data;
@@ -529,6 +530,7 @@ struct sctp_stream_queue_pending {
 	uint8_t put_last_out;
 	uint8_t discard_rest;
 	uint8_t processing;
+	bool scheduled;
 };
 
 /*
@@ -588,10 +590,13 @@ struct ss_fb {
  * This union holds all parameters per stream
  * necessary for different stream schedulers.
  */
-union scheduling_parameters {
-	struct ss_rr rr;
-	struct ss_prio prio;
-	struct ss_fb fb;
+struct scheduling_parameters {
+	union {
+		struct ss_rr rr;
+		struct ss_prio prio;
+		struct ss_fb fb;
+	}     ss;
+	bool scheduled;
 };
 
 /* States for outgoing streams */
@@ -604,7 +609,7 @@ union scheduling_parameters {
 /* This struct is used to track the traffic on outbound streams */
 struct sctp_stream_out {
 	struct sctp_streamhead outqueue;
-	union scheduling_parameters ss_params;
+	struct scheduling_parameters ss_params;
 	uint32_t chunks_on_queues;	/* send queue and sent queue */
 #if defined(SCTP_DETAILED_STR_STATS)
 	uint32_t abandoned_unsent[SCTP_PR_SCTP_MAX + 1];
@@ -731,11 +736,11 @@ struct sctp_cc_functions {
 struct sctp_ss_functions {
 	void (*sctp_ss_init) (struct sctp_tcb *stcb, struct sctp_association *asoc);
 	void (*sctp_ss_clear) (struct sctp_tcb *stcb, struct sctp_association *asoc,
-	    int clear_values);
+	    bool clear_values);
 	void (*sctp_ss_init_stream) (struct sctp_tcb *stcb, struct sctp_stream_out *strq, struct sctp_stream_out *with_strq);
 	void (*sctp_ss_add_to_stream) (struct sctp_tcb *stcb, struct sctp_association *asoc,
 	    struct sctp_stream_out *strq, struct sctp_stream_queue_pending *sp);
-	int (*sctp_ss_is_empty) (struct sctp_tcb *stcb, struct sctp_association *asoc);
+	bool (*sctp_ss_is_empty) (struct sctp_tcb *stcb, struct sctp_association *asoc);
 	void (*sctp_ss_remove_from_stream) (struct sctp_tcb *stcb, struct sctp_association *asoc,
 	    struct sctp_stream_out *strq, struct sctp_stream_queue_pending *sp);
 struct sctp_stream_out *(*sctp_ss_select_stream) (struct sctp_tcb *stcb,
@@ -748,7 +753,7 @@ struct sctp_stream_out *(*sctp_ss_select_stream) (struct sctp_tcb *stcb,
 	    struct sctp_stream_out *strq, uint16_t *value);
 	int (*sctp_ss_set_value) (struct sctp_tcb *stcb, struct sctp_association *asoc,
 	    struct sctp_stream_out *strq, uint16_t value);
-	int (*sctp_ss_is_user_msgs_incomplete) (struct sctp_tcb *stcb, struct sctp_association *asoc);
+	bool (*sctp_ss_is_user_msgs_incomplete) (struct sctp_tcb *stcb, struct sctp_association *asoc);
 };
 
 /* used to save ASCONF chunks for retransmission */
diff --git a/sys/netinet/sctp_usrreq.c b/sys/netinet/sctp_usrreq.c
index 65037f0734ea..b2d23bffb9fd 100644
--- a/sys/netinet/sctp_usrreq.c
+++ b/sys/netinet/sctp_usrreq.c
@@ -4043,7 +4043,7 @@ sctp_setopt(struct socket *so, int optname, void *optval, size_t optsize,
 			SCTP_FIND_STCB(inp, stcb, av->assoc_id);
 			if (stcb) {
 				SCTP_TCB_SEND_LOCK(stcb);
-				stcb->asoc.ss_functions.sctp_ss_clear(stcb, &stcb->asoc, 1);
+				stcb->asoc.ss_functions.sctp_ss_clear(stcb, &stcb->asoc, true);
 				stcb->asoc.ss_functions = sctp_ss_functions[av->assoc_value];
 				stcb->asoc.stream_scheduling_module = av->assoc_value;
 				stcb->asoc.ss_functions.sctp_ss_init(stcb, &stcb->asoc);
@@ -4066,7 +4066,7 @@ sctp_setopt(struct socket *so, int optname, void *optval, size_t optsize,
 					LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
 						SCTP_TCB_LOCK(stcb);
 						SCTP_TCB_SEND_LOCK(stcb);
-						stcb->asoc.ss_functions.sctp_ss_clear(stcb, &stcb->asoc, 1);
+						stcb->asoc.ss_functions.sctp_ss_clear(stcb, &stcb->asoc, true);
 						stcb->asoc.ss_functions = sctp_ss_functions[av->assoc_value];
 						stcb->asoc.stream_scheduling_module = av->assoc_value;
 						stcb->asoc.ss_functions.sctp_ss_init(stcb, &stcb->asoc);