From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Thu, 4 Aug 2022 08:11:12 +0000 (+0200)
Subject: CLEANUP: mux-quic: remove loop on sending frames
X-Git-Tag: v2.7-dev4~71
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=56c6154dba95c74659f0b2d72073e80d63b92c4b;p=thirdparty%2Fhaproxy.git

CLEANUP: mux-quic: remove loop on sending frames

qc_send_app_pkts() has now a while loop implemented which allows to send
all possible frames even if the send buffer is full between packet
prepare and send. This is present since commit :
  dc07751ed7ebad10f49081d28a9a5ae785f53d76
  MINOR: quic: Send packets as much as possible from qc_send_app_pkts()

This means we can remove code from the MUX which implement this at the
upper layer. This is useful to simplify qc_send_frames() function.

As mentionned commit is subject to backport, this commit should be
backported as well to 2.6.
---

diff --git a/src/mux_quic.c b/src/mux_quic.c
index dd9e9f4a4e..96a2b6b450 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -1349,22 +1349,6 @@ void qcc_streams_sent_done(struct qcs *qcs, uint64_t data, uint64_t offset)
  */
 static int qc_send_frames(struct qcc *qcc, struct list *frms)
 {
-	/* TODO implement an opportunistic retry mechanism. This is needed
-	 * because qc_send_app_pkts is not completed. It will only prepare data
-	 * up to its Tx buffer. The frames left are not send even if the Tx
-	 * buffer is emptied by the sendto call.
-	 *
-	 * To overcome this, we call repeatedly qc_send_app_pkts until we
-	 * detect that the transport layer has send nothing. This could happen
-	 * on congestion or sendto syscall error.
-	 *
-	 * When qc_send_app_pkts is improved to handle retry by itself, we can
-	 * remove the looping from the MUX.
-	 */
-	struct quic_frame *first_frm;
-	uint64_t first_offset = 0;
-	char first_stream_frame_type;
-
 	TRACE_ENTER(QMUX_EV_QCC_SEND, qcc->conn);
 
 	if (LIST_ISEMPTY(frms)) {
@@ -1374,34 +1358,7 @@ static int qc_send_frames(struct qcc *qcc, struct list *frms)
 
 	LIST_INIT(&qcc->send_retry_list);
 
- retry_send:
-	first_frm = LIST_ELEM(frms->n, struct quic_frame *, list);
-	if ((first_frm->type & QUIC_FT_STREAM_8) == QUIC_FT_STREAM_8) {
-		first_offset = first_frm->stream.offset.key;
-		first_stream_frame_type = 1;
-	}
-	else {
-		first_stream_frame_type = 0;
-	}
-
-	if (!LIST_ISEMPTY(frms))
-		qc_send_app_pkts(qcc->conn->handle.qc, 0, frms);
-
-	/* If there is frames left, check if the transport layer has send some
-	 * data or is blocked.
-	 */
-	if (!LIST_ISEMPTY(frms)) {
-		if (first_frm != LIST_ELEM(frms->n, struct quic_frame *, list))
-			goto retry_send;
-
-		/* If the first frame is STREAM, check if its offset has
-		 * changed.
-		 */
-		if (first_stream_frame_type &&
-		    first_offset != LIST_ELEM(frms->n, struct quic_frame *, list)->stream.offset.key) {
-			goto retry_send;
-		}
-	}
+	qc_send_app_pkts(qcc->conn->handle.qc, 0, frms);
 
 	/* If there is frames left at this stage, transport layer is blocked.
 	 * Subscribe on it to retry later.