[nginx] QUIC: prevent deleted stream frame retransmissions.

[noreply at nginx.com]

details:   https://github.com/nginx/nginx/commit/3f6d94d8881ca6755b1baa4dd6248a7b7ed15735
branches:  master
commit:    3f6d94d8881ca6755b1baa4dd6248a7b7ed15735
user:      nandsky <lishu.zy at alibaba-inc.com>
date:      Mon, 30 Sep 2024 20:51:17 +0800
description:
QUIC: prevent deleted stream frame retransmissions.

Since a2a513b93cae, stream frames no longer need to be retransmitted after it
was deleted.  The frames which were retransmitted before, could be stream data
frames sent prior to a RESET_STREAM. Such retransmissions are explicitly
prohibited by RFC 9000, Section 19.4.

---
 src/event/quic/ngx_event_quic_ack.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/event/quic/ngx_event_quic_ack.c b/src/event/quic/ngx_event_quic_ack.c
index c7ffd44dd..c953b8042 100644
--- a/src/event/quic/ngx_event_quic_ack.c
+++ b/src/event/quic/ngx_event_quic_ack.c
@@ -631,13 +631,12 @@ ngx_quic_resend_frames(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx)
         case NGX_QUIC_FT_STREAM:
             qs = ngx_quic_find_stream(&qc->streams.tree, f->u.stream.stream_id);
 
-            if (qs) {
-                if (qs->send_state == NGX_QUIC_STREAM_SEND_RESET_SENT
-                    || qs->send_state == NGX_QUIC_STREAM_SEND_RESET_RECVD)
-                {
-                    ngx_quic_free_frame(c, f);
-                    break;
-                }
+            if (qs == NULL
+                || qs->send_state == NGX_QUIC_STREAM_SEND_RESET_SENT
+                || qs->send_state == NGX_QUIC_STREAM_SEND_RESET_RECVD)
+            {
+                ngx_quic_free_frame(c, f);
+                break;
             }
 
             /* fall through */