From 8727ff466883d31a25c5e21132f07fab42b441c1 Mon Sep 17 00:00:00 2001
From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Tue, 8 Mar 2022 10:39:55 +0100
Subject: [PATCH] MINOR: mux-quic: support MAX_STREAM_DATA frame parsing

Implement a MUX method to parse MAX_STREAM_DATA. If the limit is greater
than the previous one and the stream was blocked, the flag
QC_SF_BLK_SFCTL is removed.
---
 include/haproxy/mux_quic.h |  1 +
 src/mux_quic.c             | 26 ++++++++++++++++++++++++++
 src/xprt_quic.c            |  6 ++++++
 3 files changed, 33 insertions(+)

diff --git a/include/haproxy/mux_quic.h b/include/haproxy/mux_quic.h
index a5b105376..3db440676 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_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 7a8ccfa49..e3a43f5b7 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -253,6 +253,32 @@ int qcc_recv(struct qcc *qcc, uint64_t id, uint64_t len, uint64_t offset,
 	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.
+ *
+ * Returns 0 on success else non-zero.
+ */
+int qcc_recv_max_stream_data(struct qcc *qcc, uint64_t id, uint64_t max)
+{
+	struct qcs *qcs;
+	struct eb64_node *node;
+
+	node = eb64_lookup(&qcc->streams_by_id, id);
+	if (node) {
+		qcs = eb64_entry(&node->node, struct qcs, by_id);
+		if (max > qcs->tx.msd) {
+			qcs->tx.msd = max;
+
+			if (qcs->flags & QC_SF_BLK_SFCTL) {
+				qcs->flags &= ~QC_SF_BLK_SFCTL;
+				tasklet_wakeup(qcc->wait_event.tasklet);
+			}
+		}
+	}
+
+	return 0;
+}
+
 /* Decode the content of STREAM frames already received on the stream instance
  * <qcs>.
  *
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 4e14bad6e..799621ba8 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -2456,6 +2456,12 @@ static int qc_parse_pkt_frms(struct quic_rx_packet *pkt, struct ssl_sock_ctx *ct
 		}
 		case QUIC_FT_MAX_DATA:
 		case QUIC_FT_MAX_STREAM_DATA:
+			if (qc->mux_state == QC_MUX_READY) {
+				struct quic_max_stream_data *data = &frm.max_stream_data;
+				qcc_recv_max_stream_data(qc->qcc, data->id,
+				                         data->max_stream_data);
+			}
+			break;
 		case QUIC_FT_MAX_STREAMS_BIDI:
 		case QUIC_FT_MAX_STREAMS_UNI:
 		case QUIC_FT_DATA_BLOCKED: