QUIC: do not resend empty queue when speeding up handshake.

If client acknowledged an Initial packet with CRYPTO frame and then
sent another Initial packet containing duplicate CRYPTO again, this
could result in resending frames off the empty send queue.

diff --git a/src/event/ngx_event_quic.c b/src/event/ngx_event_quic.c
index 0c32be355365cd8d12ee658f6aed5ea9bee61e8f..f503c48babdb87c0d4fff5e5de1fed180f28c4eb 100644 (file)
--- a/src/event/ngx_event_quic.c
+++ b/src/event/ngx_event_quic.c
@@ -2846,6 +2846,7 @@ ngx_quic_handle_crypto_frame(ngx_connection_t *c, ngx_quic_header_t *pkt,
 {
     uint64_t                   last;
     ngx_int_t                  rc;
+    ngx_quic_send_ctx_t       *ctx;
     ngx_quic_connection_t     *qc;
     ngx_quic_crypto_frame_t   *f;
     ngx_quic_frames_stream_t  *fs;
@@ -2871,7 +2872,11 @@ ngx_quic_handle_crypto_frame(ngx_connection_t *c, ngx_quic_header_t *pkt,
     /* speeding up handshake completion */
 
     if (pkt->level == ssl_encryption_initial) {
-        ngx_quic_resend_frames(c, ngx_quic_get_send_ctx(qc, pkt->level));
+        ctx = ngx_quic_get_send_ctx(qc, pkt->level);
+
+        if (!ngx_queue_empty(&ctx->sent)) {
+            ngx_quic_resend_frames(c, ctx);
+        }
     }
 
     return NGX_OK;