git: 0b79a76f8487 - main - sctp: improve consistency when calling stream scheduler

[Michael Tuexen]

The branch main has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=0b79a76f848768068d409edcb36f2a58cdd17e61

commit 0b79a76f848768068d409edcb36f2a58cdd17e61
Author:     Michael Tuexen <tuexen at FreeBSD.org>
AuthorDate: 2021-09-20 22:54:13 +0000
Commit:     Michael Tuexen <tuexen at FreeBSD.org>
CommitDate: 2021-09-20 22:54:13 +0000

    sctp: improve consistency when calling stream scheduler
    
    Hold always the stcb send lock when calling sctp_ss_init() and
    sctp_ss_remove_from_stream().
    
    MFC after:      1 week
---
 sys/netinet/sctp_output.c |  8 ++++----
 sys/netinet/sctp_timer.c  | 17 +++++++++--------
 sys/netinet/sctputil.c    |  4 +++-
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/sys/netinet/sctp_output.c b/sys/netinet/sctp_output.c
index 434ab7e1f8dc..27ad92527454 100644
--- a/sys/netinet/sctp_output.c
+++ b/sys/netinet/sctp_output.c
@@ -7207,13 +7207,13 @@ one_more_time:
 				    sp->put_last_out,
 				    send_lock_up);
 			}
-			if ((TAILQ_NEXT(sp, next) == NULL) && (send_lock_up == 0)) {
+			if (send_lock_up == 0) {
 				SCTP_TCB_SEND_LOCK(stcb);
 				send_lock_up = 1;
 			}
 			atomic_subtract_int(&asoc->stream_queue_cnt, 1);
 			TAILQ_REMOVE(&strq->outqueue, sp, next);
-			stcb->asoc.ss_functions.sctp_ss_remove_from_stream(stcb, asoc, strq, sp, send_lock_up);
+			stcb->asoc.ss_functions.sctp_ss_remove_from_stream(stcb, asoc, strq, sp, 1);
 			if ((strq->state == SCTP_STREAM_RESET_PENDING) &&
 			    (strq->chunks_on_queues == 0) &&
 			    TAILQ_EMPTY(&strq->outqueue)) {
@@ -7638,13 +7638,13 @@ dont_do_it:
 			    sp->put_last_out,
 			    send_lock_up);
 		}
-		if ((send_lock_up == 0) && (TAILQ_NEXT(sp, next) == NULL)) {
+		if (send_lock_up == 0) {
 			SCTP_TCB_SEND_LOCK(stcb);
 			send_lock_up = 1;
 		}
 		atomic_subtract_int(&asoc->stream_queue_cnt, 1);
 		TAILQ_REMOVE(&strq->outqueue, sp, next);
-		stcb->asoc.ss_functions.sctp_ss_remove_from_stream(stcb, asoc, strq, sp, send_lock_up);
+		stcb->asoc.ss_functions.sctp_ss_remove_from_stream(stcb, asoc, strq, sp, 1);
 		if ((strq->state == SCTP_STREAM_RESET_PENDING) &&
 		    (strq->chunks_on_queues == 0) &&
 		    TAILQ_EMPTY(&strq->outqueue)) {
diff --git a/sys/netinet/sctp_timer.c b/sys/netinet/sctp_timer.c
index e657bc280ccc..72a0a2c32c88 100644
--- a/sys/netinet/sctp_timer.c
+++ b/sys/netinet/sctp_timer.c
@@ -1344,18 +1344,18 @@ sctp_shutdownack_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
 }
 
 static void
-sctp_audit_stream_queues_for_size(struct sctp_inpcb *inp,
-    struct sctp_tcb *stcb)
+sctp_audit_stream_queues_for_size(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
 {
 	struct sctp_stream_queue_pending *sp;
 	unsigned int i, chks_in_queue = 0;
 	int being_filled = 0;
 
-	/*
-	 * This function is ONLY called when the send/sent queues are empty.
-	 */
-	if ((stcb == NULL) || (inp == NULL))
-		return;
+	KASSERT(inp != NULL, ("inp is NULL"));
+	KASSERT(stcb != NULL, ("stcb is NULL"));
+
+	SCTP_TCB_SEND_LOCK(stcb);
+	KASSERT(TAILQ_EMPTY(&stcb->asoc.send_queue), ("send_queue not empty"));
+	KASSERT(TAILQ_EMPTY(&stcb->asoc.sent_queue), ("sent_queue not empty"));
 
 	if (stcb->asoc.sent_queue_retran_cnt) {
 		SCTP_PRINTF("Hmm, sent_queue_retran_cnt is non-zero %d\n",
@@ -1364,7 +1364,7 @@ sctp_audit_stream_queues_for_size(struct sctp_inpcb *inp,
 	}
 	if (stcb->asoc.ss_functions.sctp_ss_is_empty(stcb, &stcb->asoc)) {
 		/* No stream scheduler information, initialize scheduler */
-		stcb->asoc.ss_functions.sctp_ss_init(stcb, &stcb->asoc, 0);
+		stcb->asoc.ss_functions.sctp_ss_init(stcb, &stcb->asoc, 1);
 		if (!stcb->asoc.ss_functions.sctp_ss_is_empty(stcb, &stcb->asoc)) {
 			/* yep, we lost a stream or two */
 			SCTP_PRINTF("Found additional streams NOT managed by scheduler, corrected\n");
@@ -1406,6 +1406,7 @@ sctp_audit_stream_queues_for_size(struct sctp_inpcb *inp,
 		    (u_long)stcb->asoc.total_output_queue_size);
 		stcb->asoc.total_output_queue_size = 0;
 	}
+	SCTP_TCB_SEND_UNLOCK(stcb);
 }
 
 int
diff --git a/sys/netinet/sctputil.c b/sys/netinet/sctputil.c
index c6cdd3315704..a7eb50716cc9 100644
--- a/sys/netinet/sctputil.c
+++ b/sys/netinet/sctputil.c
@@ -1288,6 +1288,7 @@ sctp_init_asoc(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
 		SCTP_LTRACE_ERR_RET(NULL, stcb, NULL, SCTP_FROM_SCTPUTIL, ENOMEM);
 		return (ENOMEM);
 	}
+	SCTP_TCB_SEND_LOCK(stcb);
 	for (i = 0; i < asoc->streamoutcnt; i++) {
 		/*
 		 * inbound side must be set to 0xffff, also NOTE when we get
@@ -1315,7 +1316,8 @@ sctp_init_asoc(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
 		asoc->strmout[i].last_msg_incomplete = 0;
 		asoc->strmout[i].state = SCTP_STREAM_OPENING;
 	}
-	asoc->ss_functions.sctp_ss_init(stcb, asoc, 0);
+	asoc->ss_functions.sctp_ss_init(stcb, asoc, 1);
+	SCTP_TCB_SEND_UNLOCK(stcb);
 
 	/* Now the mapping array */
 	asoc->mapping_array_size = SCTP_INITIAL_MAPPING_ARRAY;