From 1e5e5136eebb4ea18cd319d169b2a64d7010d3eb Mon Sep 17 00:00:00 2001
From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Tue, 8 Mar 2022 16:23:03 +0100
Subject: [PATCH] MINOR: mux-quic: support MAX_DATA frame parsing

This commit is similar to the previous one but with MAX_DATA frames.
This allows to increase the connection level flow-control limit. If the
connection was blocked due to QC_CF_BLK_MFCTL flag, the flag is reseted.
---
 include/haproxy/mux_quic.h |  1 +
 src/mux_quic.c             | 18 ++++++++++++++++++
 src/xprt_quic.c            |  5 +++++
 3 files changed, 24 insertions(+)

diff --git a/include/haproxy/mux_quic.h b/include/haproxy/mux_quic.h
index 3db440676..ea6986c58 100644
--- a/include/haproxy/mux_quic.h
+++ b/include/haproxy/mux_quic.h
@@ -22,6 +22,7 @@ void qcs_notify_send(struct qcs *qcs);
 
 int qcc_recv(struct qcc *qcc, uint64_t id, uint64_t len, uint64_t offset,
              char fin, char *data, struct qcs **out_qcs);
+int qcc_recv_max_data(struct qcc *qcc, uint64_t max);
 int qcc_recv_max_stream_data(struct qcc *qcc, uint64_t id, uint64_t max);
 int qcc_decode_qcs(struct qcc *qcc, struct qcs *qcs);
 void qcc_streams_sent_done(struct qcs *qcs, uint64_t data, uint64_t offset);
diff --git a/src/mux_quic.c b/src/mux_quic.c
index e3a43f5b7..3242d8f8d 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -253,6 +253,24 @@ int qcc_recv(struct qcc *qcc, uint64_t id, uint64_t len, uint64_t offset,
 	return 0;
 }
 
+/* Handle a new MAX_DATA frame. <max> must contains the maximum data field of
+ * the frame.
+ *
+ * Returns 0 on success else non-zero.
+ */
+int qcc_recv_max_data(struct qcc *qcc, uint64_t max)
+{
+	if (qcc->rfctl.md < max) {
+		qcc->rfctl.md = max;
+
+		if (qcc->flags & QC_CF_BLK_MFCTL) {
+			qcc->flags &= ~QC_CF_BLK_MFCTL;
+			tasklet_wakeup(qcc->wait_event.tasklet);
+		}
+	}
+	return 0;
+}
+
 /* Handle a new MAX_STREAM_DATA frame. <max> must contains the maximum data
  * field of the frame and <id> is the identifier of the QUIC stream.
  *
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 799621ba8..9a1e9eb5c 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -2455,6 +2455,11 @@ static int qc_parse_pkt_frms(struct quic_rx_packet *pkt, struct ssl_sock_ctx *ct
 			break;
 		}
 		case QUIC_FT_MAX_DATA:
+			if (qc->mux_state == QC_MUX_READY) {
+				struct quic_max_data *data = &frm.max_data;
+				qcc_recv_max_data(qc->qcc, data->max_data);
+			}
+			break;
 		case QUIC_FT_MAX_STREAM_DATA:
 			if (qc->mux_state == QC_MUX_READY) {
 				struct quic_max_stream_data *data = &frm.max_stream_data;